Category Archives: Outside of NYC

WxChallenge for Omaha, Nebraska (KOMA) | Oct 16-19

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Last Week’s Results

Tough week last week, with the major forecast bust I had on precipitation for Oct 9 for Omaha, plus generally underwhelming performances on temperatures the remainder of the week. Since I did pretty well the on the first city, and am better this week, my cumulative rank hasn’t gone down too much and I’m sitting at #263 nationwide (out of 1500) as of this writing.

Verifications

Below are the verified readings for each metric we were asked to forecast during last week, and a column showing error points I was assessed.

 

Forecast Day Max Temp (°F) Min Temp (°F) Max Sustained Wind (kts) Precipitation (inches) Error Points Assessed
10/09/2018 57 50 16 0.74 22.7
10/10/2018 50 40 23 0.01 7.9
10/11/2018 51 38 19 0.00 8.0
10/12/2018 47 39 10 0.12 5.3

Post-Mortem

Day 1: Major bust across the board. Was off by more 5 degrees or more on both the high and low. This made up about half of the error points. The rest came from being off on max precipitation by more than 1.20”. MOS was considerably off the mark with temperatures – though NAM was closer. This was all due to the fact that a stationary frontal boundary never made it close enough to KOMA to realize warmer temperatures, and heavier precip. The axis of the 850 mb LLJ stayed south and east, along with the best surface convergence. As a result, nearly all of the model guidance was horribly wrong. The closest forecast in the class was still nearly 0.50” too high. I put too much credence into the upwards trends on the models – there were some indications already that KOMA was trending to be on the drier side of this event. Still, even if I had nailed the precipitation forecast, I would have busted hard on the temperatures. Need to be a lot more cautious going forward about situations where a frontal boundary and precipitation are around, and probably hedge down on temperatures during transitional seasons when a forecast site could be on the cold side of a front with rain.

Days 2-4: Much better forecasting overall, especially in regards to precipitation. However, got a lot of error points for being too cold across the board with temperatures. Buying into the colder temperatures in MOS made for an overall forecast that was too cold.

Forecasting for Week 2 at KOMA (Omaha, NE) Oct 16-19

Synoptic Set Up

A much quieter weather week is in store for Omaha. With high pressure building, most of the forecast week will see sunny or clear conditions. Light synoptic flow suggests the possibility for winds decoupling at night, giving rise to highly favorable conditions for strong radiational cooling. Temperatures will be trending up through the week as a upper-level trough moves east and heights continue to build.

Notes

NAM MOS guidance seems to be the preferred alternative with respect to overnight lows, given that forecast soundings show a clear signal for nocturnal inversions. Our class discussion notes that 1.4” of snow fell at KOMA over the weekend. Temperatures are in the mid-40s today, but cold overnight lows may mean that we need to consider patchy snow cover in forecasting overnight lows. Since overnight lows are expected to be quite cold to start the week, daytime highs should also be below normal for this time of year. The NWS official forecast does show a warming trend in overnight lows through the week. Delta Method was suggested as a possible approach, and makes sense with how similar the air masses will be day to day. The trickiest part of the forecast this week will be how cold overnight with conditions conducive to strong radiational cooling, and just how much things can warm up during the day.

Forecasts Submitted

This only reflects finalized forecasts, I’ve made small adjustments to the forecast based on checking MOS daily.

Forecast Day Max Temp (°F) Min Temp (°F) Max Sustained Wind (kts) Precipitation (inches)
10/16/2018 60 33 13 0.00
10/17/2018 58 37 7 0.00
10/18/2018 64 43 15 0.00
10/19/2018 69 49 16 0.00

WxChallenge for Omaha, Nebraska (KOMA) | Oct 9-12

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A couple days into the forecast period for the second WxChallenge city for this fall, and I’ve experienced my worst forecast bust (for yesterday). Highlights in the post-mortem section. It has been a week of transitions for Omaha, which started off with relatively mild conditions but will end the week with possibility for patchy frost!

Synoptic Set Up

A 500 mb longwave trough will with multiple attendant vorticity maxima will pivot through the KOMA region during the first half of the forecast period before flow becomes more zonal. At the 300 mb level, multiple jet streaks could boost divergence with these 500 mb vorticity maxima. This enhanced lift, and strong wind shear profile could lead to some isolated strong-severe thunderstorms. The 850 mb shows evidence of a decently robust LLJ that would should bring a continuous supply of Gulf moisture up the Missouri Valley into the area. At the surface, a warm front looks to lift through Monday, then stall as a cold front in the vicinity of KOMA through late Wednesday due to the deep unidirectional winds parallel to the front boundary.

Notes

The potential for flash flooding, and bouts of heavy rain, is duly noted in the AFD during the first half of the weak. The synoptic ingredients for a long duration rainfall event are certainly evident. Soils in the area are already quite moist, given that flood warnings were present for stretches of the Missouri last week. GFS MOS QPF range on Sunday for 06Z Tuesday to 06Z Wednesday was 1.75-4.46”. NAM MOS QPF range for this time was 1.35-2.71”, consensus was 1.55-3.59”. Records around this time of year for QPF show that 1-2” can easily occur, despite the normal being only a mere 0.07”. SREF probabilities of >= 0.50” were above 90% for this period, and >= 1.00” was 50-70%, but over 2.00” of QPF probabilities were less than 10%. SREF mean was 2.73”, with a pretty large spread, from 0.69-5.54”. GFS mean was 3.93” with spread of 1.82-5.16”. For now, going with a superblend of the low-end of the ranges of MOS and plumes: 1.40”.

As of Monday, SREF and GEFs means had become much better aligned, with SREF mean at 2.83” and GEFs mean 2.95”. SREF spread was 1.34-4.46”, GEFs was 1.43-4.43”. QPF forecast shows KOMA a pretty large QPF gradient, and that uncertainty seems borne out well in the ensemble forecasts. SREF probabilities of >= 2.00” increased to the 10-30% with KOMA lying right on the fringe of 30-50% probabilities of this amount. >= 1.00” probabilities increased to 70-90%. Official NWS forecast as of 10Z Monday called for 1.65” during the forecast period Tuesday. GFS MOS QPF range was 2.10-4.21”, NAM 1.01-2.06”, consensus here is 1.55-3.13”. Based on these updates, I’m increasing my forecast to 1.85” – I’m hedging down below the SREF and GEFS means because I’m still not sure where the stationary/slow-moving surface front will set up in relation to KOMA, and where the best lift will be for heavy rain/thunderstorms as a result. Also, if the 850 mb LLJ fails to materialize close to KOMA, we could be looking at lower overall totals. Low SREF probabilities of over 2.00” also help justify this call. Looking at Wednesday, rain chances diminish considerably after the front moves through, but the story then becomes strong winds possible, with MOS pointing at 17-20 knot synoptic winds.

Ensembles continue to trend upwards as of Monday afternoon with QPF, SREF mean now 2.96” and GEFS mean is 3.16”. SREF probabilities are close to placing KOMA in the 50% >= 2.00” QPF. Will take one more look at 18Z MOS guidance and some other factors before finalizing, but am leaning towards increasing the precip forecast again, this time to maybe 1.90” I’m wary of going for 3” of QPF or higher, given that the entire month’s single-day QPF record is 3.09”. Even beyond 2” still seems unlikely.

On Tuesday, looking ahead at Wednesday and Thursday, the passage of a cold front is quite evident. Temperatures are forecast to drop considerably compared with the beginning of the weak, and precipitation will end, too. The forecast for Wednesday still retains a slight chance for some measurable QPF on the tail end of the main precipitation event Tuesday. Models have backed down from up to 0.25” of precip to less than 0.10”. SREF and GEFS means show approximately 0.04” on Wednesday. SREF probabilities showed that KOMA had a greater than 90% chance of receiving precipitation >= 0.01”, but less than 10% of >= 0.10”, going to go straight up with the ensemble means here. The other story for Wednesday will be stiff winds from the northwest, with MOS synoptic winds of 17-18 knots. This suggests even stronger sustained winds, and will aid in cold advection, keeping high temperatures suppressed. These blustery conditions are forecast to gradually abate by late in the day Thursday, such that the strongest winds Thursday should occur early in the overnight hours. Cold temperatures overnight into Thursday should be somewhat tempered by decent vertical mixing and overcast skies.

Forecasts Submitted

This only reflects finalized forecasts, I’ve made small adjustments to the forecast based on checking MOS daily.

Forecast Day Max Temp (°F) Min Temp (°F) Max Sustained Wind (kts) Precipitation (inches)
10/09/2018 62 57 14 1.91
10/10/2018 48 44 20 0.02
10/11/2018 48 34 17 0.00
10/12/2018 48 35 9 0.10

Post-Mortem

Day 1: Major bust across the board. Was off by more 5 degrees or more on both the high and low. This made up about half of the error points. The rest came from being off on max precipitation by more than 1.20”. MOS was considerably off the mark with temperatures – though NAM was closer. This was all due to the fact that a stationary frontal boundary never made it close enough to KOMA to realize warmer temperatures, and heavier precip. The axis of the 850 mb LLJ stayed south and east, along with the best surface convergence. As a result, nearly all of the model guidance was horribly wrong. The closest forecast in the class was still nearly 0.50” too high. I put too much credence into the upwards trends on the models – there were some indications already that KOMA was trending to be on the drier side of this event. Still, even if I had nailed the precipitation forecast, I would have still busted hard on the temperatures. Need to be a lot more cautious going forward about situations where a frontal boundary and precipitation are around, and probably hedge down on temperatures during transitional season when a forecast site could be on the cold side of a front with rain.

WxChallenge for Portland International Airport (KPDX) | Oct 2-5

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Last Week’s Results

After the first week of the WxChallenge (and part of this week), I’m second place in my class, tied with multiple others for #268 nationwide, and a little better than national consensus with 21.2 error points. I got hit the last day for going over on temperatures and winds, and will discuss that below. Hats off to one of my classmates who’s currently #44 nationwide!

Verifications

Below are the verified readings for each metric we were asked to forecast during last week, and a column showing error points I was assessed.

Forecast Day Max Temp (°F) Min Temp (°F) Max Sustained Wind (kts) Precipitation (inches) Error Points Assessed
09/25/2018 82 50 11 0.00 4.0
09/26/2018 83 52 11 0.00 1.0
09/27/2018 84 52 9 0.00 2.5
09/28/2018 86 53 11 0.00 6.5

Post-Mortem

Day 1: went too aggressive on the max winds, and too warm on the low temps. The lower winds could explain the lower min temps (less mixing on clear nights). I think I was too optimistic about the possibility of funneling of winds from the ENE along the Columbia River Gorge.

Day 2: did pretty well, only got 1 point off for missing the high temp slightly. If I had stayed with my original forecast for that I would have had a perfect score! Much better on winds though.

Day 3 & Day 4: another decent day, but went a little too cool with the low temperatures. This low bias also bled into Day 4, where I was low on both the high, low, and max sustained wind speeds. I think if I were to go back and redo this, maybe I would have used the Delta Method (a form of moderate persistence) and been better off than looking at MOS, given how stable conditions were throughout the week.

Forecasting for KPDX October 2-5, 2018

Synoptic Set Up

Big changes in store for Oregon in the second week of the forecast challenge. The rex block and high pressure that brought a week of above normal warmth and clear skies last week will finally break down. The upper low associated with it will move northeast towards KPDX over the weekend. Local NWS forecasters currently (as of Thursday) noted considerable spread in forecast guidance about phasing of northern stream energy and a second upper low by the beginning of this forecast period, as well as interaction with outflow from Hurricane Rosa. AFD mentions longwave troughing as well, and this is backed up by GFS progs.

Rainy start to the week at KPDX possible
Coastal low coming ashore on Friday at KPDX

 

Forecast Rationale

The effects of the synoptic set up favor much cooler and unsettled conditions compared to last week. A drop in 500 mb heights with upper lows and longwave trough should result in temperatures close to or slightly below climatological norms. The prospect of this troughing means that precipitation will be in the mix as well at the start of the week. More substantial rain chances are in store for KPDX to end the week. Along with the rain Friday, we can expect cooler temperatures and windy weather as rain cooled air helps mix down some momentum from the lower atmosphere.

Forecasts Submitted

This only reflects finalized forecasts as of this posting, I’ve made small adjustments to the forecast based on checking MOS daily.

Forecast Day Max Temp (°F) Min Temp (°F) Max Sustained Wind (kts) Precipitation (inches)
10/02/2018 68 54 11 0.05
10/03/2018 67 45 7 0.00
10/04/2018 66 46 7 0.00
10/05/2018 57 49 15 0.28

WxChallenge for Portland International Airport (KPDX) | Sept 25-28

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Temporary Changes to this Blog

Over the next few weeks, I’m going to take a break from my normal posts about weather in NYC and the region because I’m participating in the WxChallenge national weather forecasting competition. This is a course requirement for the final semester of the Undergraduate Certificate in Weather Forecasting program with Penn State University’s World Campus that I’m enrolled in. During the course of this competition, I will be providing forecasts of high temperatures, low temperatures, maximum sustained winds, and total precipitation for various cities in the challenge. The first of these cities will be Portland, Oregon – specifically Portland International Airport (KPDX). If events of particular interest, such as severe weather, tropical storms, or etc are forecast to occur in NYC, I will make special posts regarding such events.

Forecasting for KPDX September 25-28, 2018

Synoptic Set Up (The Big Picture)

High pressure was located at the surface west of KPDX. A rex blocking pattern existed over the Pacific (a upper level high directly north of an upper level low, see animation below, the upper level high is west of OR/WA and shaded with some light blues, the upper level low just south of it shaded with oranges/reds). Some northeasterly winds were forecast during the forecast days, especially later in the day/overnight, which given the topography surrounding KPDX would lead to some downsloping. Still, northwesterly was forecast to be the predominant wind direction, which aligns well with climatological norms for September. A thermal low was mentioned to be in place through the mid-week period that would migrate daily from west to east.

Forecast Rationale

The synoptic set up favors little change in day-to-day conditions. Downsloping and the presence of a thermal low over the Willamette Valley suggest warmer than climatological and MOS (Model Output Statistics) guidance max temps. Despite mostly clear to clear skies throughout the forecast period, radiational cooling at night should be limited due to winds expected to be easterly overnight. When there are clear skies with no/calm winds, this allows infrared radiation to efficiently escape into space from the Earth’s surface, resulting in cooler temperatures when compared with a cloudy and/or windy night. Of note, easterly winds produce the fastest winds for KPDX due to some funneling effects from the Columbia River Gorge (think of this like blowing through a straw). This was referenced in the local forecast AFD. However, the MOS guidance didn’t really show a clear signal of wind directions favorable to strong funneling, so it would be unwise to go too much above guidance here. Late week cool down noted as the rex block breaks down and the upper low that was associated with makes its way towards the west coast. Exact placement/timing could bring some precipitation in the picture by the weekend and maybe early into week 2 forecast period.

Forecast Submitted

Forecast Day Max Temp (°F) Min Temp (°F) Max Sustained Wind

(knots)

 Precipitation (inches)
09/25/2018 82 52 15 0.00
09/26/2018 82 52 11 0.00
09/27/2018 85 54 8 0.00
09/28/2018 83 55 6 0.00

NYC Memorial Day Weekend Weather – May 25, 2018

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Memorial Day weekend in NYC kicks off with two incredible days of summer-like weather with excellent conditions for all outdoor activities, including hitting the beach. The weather shifts markedly for Sunday and Monday as a cooler air mass takes hold of the region behind a backdoor cold front. Temperature could be 15ºF-20ºF cooler between the first and second half of the weekend. Rain will accompany the passage of the backdoor cold front Saturday night into Sunday. No day will be a washout though.

Rest of today – sunny with breezy southwesterly winds bringing in warm air. Temperatures should soar into the upper-80s with a few spots reaching the 90ºF mark outside of coastal areas where sea breezes should set up fairly quickly.

Saturday – warm again with high temperatures likely reaching to around 90ºF away from south-facing shores with the influence of sea breezes. Late in the day towards the evening hours, a backdoor cold front will be approaching from the north. Ahead of this frontal boundary, clouds will increase throughout the day, and some pop up showers and thunderstorms could occur. Sea breezes may help initiate some of these storms closer to the coast. Given that there will be some instability in the atmosphere, a couple of these storms could approach severe limits, with strong wind gusts and heavy rain.


Sunday – overnight from Saturday into Sunday is when the bulk of the rain associated with this cold front will fall. There could be a scattered thunderstorm overnight. Rain will impact the beginning of the day Sunday, but conditions should improve later in the afternoon. Behind the backdoor front, easterly onshore winds will predominate, leading to much cooler temperatures only in the low-70s under cloudy skies.

Monday (Memorial Day) – cool with partly sunny skies and high temperatures in the low-70s.

 

First Tropical Storm of the 2018 Atlantic Hurricane Season

Although our weekend weather won’t be ideal, we are lucky not to have to plan for anything worse. Residents of the Gulf Coast between Louisiana and Florida Panhandle will need to contend with the arrival of the first named storm of the 2018 Atlantic hurricane season, Subtropical Storm Alberto.

NYC Weekend Weather – Columbus Day – Oct 6, 2017

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The first half of this long weekend will continue the warm summer feel we’ve had since mid-week. Some much needed rain arrives Sunday going into next week in conjunction with the anticipated remnants of Tropical Storm Nate. This does literally mean that it will rain on the Columbus Day parade.

Rest of today – mostly sunny. Warm with highs around 80°F.

Saturday – partly sunny, not a bad day though with high temperatures in the low-80s. The stationary front depicted above that’s sitting close to the city will push north of us as a warm front. This will open the door to an increasingly tropical feel with higher dew points and more moisture in the air.

 

Sunday – mostly cloudy. Rain chances increasing in the afternoon with thunderstorms possible. Rain that develops could be heavy with tropical moisture flowing into the area. Still warm, with temperatures in the low-80s. An advancing cold front will push up precipitation partially fueled by Tropical Storm Nate (which is anticipated to make landfall on the New Orleans/Mississippi coastal area this weekend. This precipitation will be moving in on our area well in advance of the actual core of the remnants of Nate.

Monday (Columbus Day) – rain and thunderstorms as the bulk of the remnants of Nate move into the area. Rain heavy at times. Cooler with highs dipping into the mid-70s. With Nate approaching to the southwest of us, we should see more steady rain and clouds, keeping temperatures suppressed.

 

Tropical Storm Nate

Tropical Storm Nate is expected to strengthen into a minimal hurricane after it crosses near or over the northeastern Yucatan Peninsula this weekend and into the Gulf of Mexico. From that point, it’s expected to accelerate towards the Gulf Coast and make landfall in the vicinity of New Orleans, the Mississippi Delta and coastal Mississippi. Even though this storm will pale in comparison to Irma and Maria, it has already claimed 20 lives in Central America due to heavy rains and flooding.

 

NYC Weekend Weather – Eye on Jose – Sep 15, 2017

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The main weather headline going into the weekend is the eventual track of Tropical Storm Jose. Depending on its proximity to land, we could see some nasty effects from the storm next Tuesday or Wednesday. The weekend itself should be rather uneventful, the veritable calm before the storm.

Rest of today – warm and mostly sunny. Small chance for an isolated PM pop-up thunderstorm especially inland and west.

Saturday – more clouds but still a nice day with highs around 80°F.

Sunday – probably the best day of the weekend with mostly sunny skies and a high around 80°F again.

Monday – pleasant enough to start the week. Increasing clouds, which will end the streak of above normal weather. With Jose approaching from the south we may also see increasing onshore winds cooling things off.

 

Jose an Increasing Threat to the East Coast

While Texas, Florida, and parts of the Caribbean are still reeling from the impacts of major hurricanes Harvey and Irma, Jose could pose a problem for us along the East Coast. Jose has been meandering aimlessly in the western Atlantic over the last few days and has done an anti-cyclonic loop. It’s now beginning to move west-northwest and there are a few forecast models that show it making landfall along the East Coast or coming very close to it.

It shouldn’t be too surprising that the cone of uncertainty in the official National Hurricane Center’s forecast is so large at day 5 given the substantial spread that exists amongst individual members of different modeling systems. Note that there is still plenty of time for this storm to curve out to sea with primary impacts being limited to beach erosion and coastal flooding. However, if the storm comes closer to shore or makes landfall, then we’re talking about a much more substantial problem.

Critical factors for steering this storm will include the strength of a blocking ridge (area of high pressure) which you can see in the upper right of the following image, and whether Jose gets picked up by a frontal boundary and pushed east. A stronger high pressure would block Jose’s eastward progress, and the timing of the frontal boundary passing over the East Coast will be crucial.

Jose is expected to intensify somewhat back to a minimal Category 1 storm over this time. On its approach to this area, it’s possible that it might begin the process of extratropical transition, where its center becomes less defined and loses a warm core. However, this process could also infuse some energy via baroclinic forcing that actually strengthens the storm, much as was the case with Superstorm Sandy. The concern for this storm is the long period it spends over open water where it has the potential to churn up storm surge. Even if there’s no landfall, it doesn’t mean it can’t affect coastal areas with surge or flooding.

This model run of the GFS shows Jose stalling out very close to Long Island, then brushing Cape Cod, much like a Nor’easter.

 

And don’t look now but we could be seeing the formation of tropical storms Lee and Maria in the Atlantic as well. The storm further to the west could pose a threat to the southern Lower Antilles next week.

Hurricane Irma Update – 5PM, Sep 9, 2017

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Hurricane Irma has made landfall on the mainland of the Florida Peninsula at Marco Island. The eye is directly over Naples as of the time of this post. As the winds start to shift to the west and southwest in areas south of the eye of Irma, destructive storm surge will rapidly become a serious threat to life and property. The storm has weakened somewhat to a strong Category 2 with 110 mph winds. This does not diminish the wind threat, or the storm surge, flooding rain, and tornado threat.

Current Situation

Irma’s eye has filled in again as it’s interacting with Florida. It is a large, powerful storm which easily covers the entire state of Florida. There are still widespread reports of hurricane force wind gusts along the east coast of Florida, despite the eye being on the opposite side of the state.

Headlines

  • Storm surge has been flooding the streets of Miami all day. The storm surge threat will become very dangerous for southwest Florida in the next couple hours as the eye moves north along the west coast of Florida. This will bring onshore winds from the west and southwest and push the ocean over land.
  • Onshore winds along northern Florida and the Georgia/South Carolina coasts tonight will bring a storm surge risk there as well.
  • Wind threat is less serious than it was when Irma was still a strong Category 4, but a 110 mph Category 2 storm is still serious. Wind gusts recorded at Naples reached 142 mph. The northern eyewall is packing the biggest punch and this will continue to advance north along the west coast of Florida.
  • Next cities in line for a beating will be Fort Myers, Port Charlotte, and then the Tampa Bay area.
  • Tornado warnings have been popping up along the east coast of Florida with some of the stronger bands of Irma.

Forecast Track

It is pretty clear now that Irma will continue north to just west of north as it traverses the state of Florida along its west coast. Tampa Bay is the largest city at risk along this path.

Forecast Intensity

Irma is still expected to maintain hurricane strength until Monday. It should pass over Tampa Bay as a strong Category 2 storm. It will continue to gradually weaken during the next 48 hours followed by more rapid weakening.

Hurricane Irma Update – 11AM Sep 10, 2017

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Hurricane Irma made landfall traversed the Florida Keys overnight as a powerful 130 mph Category 4 storm. As suspected, it was able to re-strengthen slightly over the warm waters of the Florida Straits. Landfall on the southwest coast of Florida somewhere near Naples is imminent. The forecast track is a worst case scenario for Tampa Bay, which could experience a direct hit from Irma’s eye as a Category 3 storm.

Current Situation

As of 11AM, Irma was a Category 4 storm with max sustained winds of 130 mph. It was located in the Gulf of Mexico between Key West and Naples and moving north or north-northwest.

Headlines

  • Landfall on southwest Florida will occur this afternoon as a Category 4. Devastating wind damage is expected.
  • Storm surge will occur on the southwestern side of Irma. As of now, offshore winds from the north side of Irma are pushing water out to sea. This water will return as a storm surge once winds shift to onshore on the backside of the storm.
  • Devastating winds impacts are expected for Tampa Bay with this forecast track. This will be the first direct impact of a hurricane of this magnitude in Tampa Bay since 1921.
  • Heavy, flooding rain is expected across Florida as well as much farther inland in the Southeast.

Forecast Track

Forecast models are tightly clustered on a solution that takes Irma right up the west coast of Florida. This puts the cities of Naples, Fort Myers, Port Charlotte, and Tampa Bay at high risk of experiencing the worst winds from Irma’s core.

Forecast Intensity

Irma is expected to weaken as it moves up through the coast of Florida. However, it will still be a dangerous Category 3 or strong Category 2 storm when passing Tampa Bay. It will also likely bring strong winds to large parts of Georgia.

Hurricane Irma Update – 5PM Sep 9, 2017

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Hurricane Irma is moving away from the north shore of Cuba and entering the very warm waters of the Florida Straits. While it’s still moving west-northwest, it is still anticipated to finally make a turn towards the northwest as it’s rounding the southwestern periphery of the high pressure over the Atlantic that has steered it up to this point.

Current Situation

Irma’s eye shows some signs of organization and clearing up. The National Hurricane Center still pegs the storm as a Category 3 storm with 125 mph winds. As outlined in previous posts, the land interaction with Cuba has produced adverse effects on Irma, disrupting its core and causing it to weaken. However, now that it is clearing the island of Cuba and into the open waters of the Florida Straits, it should still have a window to re-intensify before hitting Florida.

Headlines

  • Forecast models are converging on a solution that takes Irma just inland and parallel to the west coast of Florida after a landfall near Marco Island.
  • First landfall could occur somewhere between Key West and Marathon Key.
  • Fort Myers, Cape Coral, Naples, Port Charlotte, and the Tampa Bay area are under serious risk of a direct hit from the eye of Irma, which could regain Category 4 strength. Storm surge is a major concern for the west coast of Florida and the southwest of the state in particular.
  • Miami and the South Florida region are less at risk from the worst of the winds, but other hazards like flooding, storm surge, and tornadoes persist. Again, the strongest winds of a hurricane in the northern hemisphere occur on the eastern side of the storm, which will impact the east coast of Florida.
  • Should the track of Irma inland but near the coast bear out, this would likely result in a slower decline in the hurricane’s strength. It would bring more risk of inland hurricane impacts to Georgia.

Forecast Track

Forecast Intensity

The National Hurricane Center forecast does call for some moderate re-intensification of Irma prior to landfall in Florida. This forecast calls for sustained winds of 140 mph prior to landfall. There are no inhibiting factors to the storm re-intensifying once it gets over open water. Wind shear is low. Sea surface temperatures are very warm.

Uncertainties

  • Internal fluctuations in the storm could still interrupt any re-strengthening.
  • On the other hand, there is a small chance for some rapid intensification if the storm gets organized again.
  • Since model forecasts haven’t changed since earlier today, this lends higher confidence to a track along the west coast of Florida.