Written by Sig Silber

Note: This article has been updated – Go to Tracking Irma while also Assessing Storm Impacts – 10Sep2017

6:10 PM EDT Sept 9: Reflects Corrected NHC Discussion. Interaction with Cuba has weakened Irma but it will continue as a hurricane for 24 hours. The latest track guidance is “near or over the Florida Peninsula”.  It is not clear which would be more problematical for the Florida West Coast but “over land” would lead to a more rapid weakening of the storm as it moves north. The GEI Irma Report is updated frequently. Our graphics update automatically. If the article is in your email, the graphics will still update. You can access the NHC Watches and Warnings Here. Other NHC information can be found at this link. We now see other websites that will show up in a search on National Hurricane Center which are not government websites so be aware of that. 

Irma is now considered to be an imminent threat to CONUS.

Part A will be the current weather forecasts as they involve Irma.

Part B will be the physical and human impacts of Harvey and Irma.

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Part A.  Here we focus on the Meteorological Aspects of the Storms impacting or potentially impacting CONUS. We attempt to keep this information up to date. We will update this information frequently and one can also access some of this information directly from NOAA here if it has Hurricane status or potential or here if it has been downgraded to a Tropical Storm. It is our goal to provide in this continually updated report the information that readers will find most useful. But those links have additional information.

For some purposes, you might want to consult our Monday Weather and Climate report as that report has additional information on the overall weather situation. You can always find the location of all of our reports by clicking here.

Let’s Focus on Irma.

Latest Reported Track Forecast

Latest Irma Discussion

Hurricane Irma Discussion Number 43 NWS National Hurricane Center Miami FL 500 PM EDT Sat Sep 09 2017

Data from a NOAA Hurricane Hunter plane sampling Irma indicate that the hurricane has not recovered yet from its interaction with Cuba. It is estimated that the maximum winds are 110 kt. Given the excellent satellite presentation, the lower pressure just reported by the NOAA plane, and the fact that the hurricane will move over the warm waters of the Straits of Florida, some intensification is anticipated during the next 24 hours. Irma is expected to remain a very dangerous hurricane while it moves near or over the Florida Keys and near or over the Florida Peninsula. After 48 hours, Irma will be moving farther inland and weakening.

Radar data indicate that Irma is moving toward the west-northwest at about 8 kt. The turn toward the northwest and north-northwest is about to begin since the hurricane is already at the western edge of the subtropical ridge.  The track guidance continues to be tightly packed, and the bulk of the models take the hurricane over the Florida Keys and near or over the Florida Peninsula. The NHC forecast is in the middle of the guidance envelope, and given the good agreement among models, the confidence in the track forecast is high.

KEY MESSAGES:

1. Irma is expected bring life-threatening wind and storm surge to the Florida Keys and southwestern Florida as an extremely dangerous major hurricane tonight through Sunday. Preparations in southwest Florida should be completed within the next few hours, as tropical-storm-force winds are expected to begin tonight.

2. There is an imminent danger of life-threatening storm surge flooding in portions of central and southern Florida, including the Florida Keys, where a Storm Surge Warning is in effect. The threat of catastrophic storm surge flooding is highest along the southwest coast of Florida, where 10 to 15 feet of inundation above ground level is expected. This is a life-threatening situation, and everyone in these areas should immediately follow any evacuation instructions from local officials.

3. Irma will bring life-threatening wind impacts to much of Florida regardless of the exact track of the center. Wind hazards from Irma are also expected to spread northward through much of Georgia and portions of South Carolina and Alabama.

4. Irma is expected to produce very heavy rain and inland flooding. Total rain accumulations of 10 to 20 inches, with isolated amounts of between 20 and 25 inches, are expected over the Florida Keys, the Florida peninsula, and southeast Georgia from Saturday through Monday. Significant river flooding is possible in these areas. Early next week Irma will also bring periods of heavy rain to much of the southeast United States where an average of 2 to 6 inches is forecast, with isolated higher amounts, from North and South Carolina to Tennessee and eastern Alabama. This includes some mountainous areas which are more prone to flash flooding.  Residents throughout the southeast states should remain aware of the flood threat and stay tuned to forecasts and warnings.

FORECAST POSITIONS AND MAX WINDS

INIT  09/2100Z 23.4N  80.5W  110 KT 125 MPH

12H  10/0600Z 24.1N  81.3W  115 KT 130 MPH

24H  10/1800Z 25.7N  82.0W  120 KT 140 MPH

36H  11/0600Z 28.3N  82.6W  100 KT 115 MPH

48H  11/1800Z 31.2N  83.8W   65 KT  75 MPH…INLAND

72H  12/1800Z 35.5N  88.0W   25 KT  30 MPH…POST-TROP/INLAND

96H  13/1800Z 36.1N  89.0W   25 KT  30 MPH…POST-TROP/INLAND

120H  14/1800Z…DISSIPATED

Those impacted should consult their local sources of information. The Public Advisories and other information that is available from the NOAA National Hurricane Center can be found here.

And right behind Irma: Jose which appears to be forecast to turn out to sea and may be doing a loop de loop. But there may be yet another storm to follow Jose but this is no means guaranteed.

Current Conditions and Short-Term Forecast. The Above Information was Provided by the National Hurricane Center. Now I Present information from Other Parts of NOAA. 

Additional Graphics

This is a national animation of weather fronts and precipitation forecasts with four 6-hour projections of the conditions that will apply covering the next 24 hours and a second day of two 12-hour projections the second of which is the forecast for 48 hours out and to the extent it applies for 12 hours, this animation is intended to provide coverage out to 60 hours. This graphic is now very relevant. Irma early impacts are shown. Irma is shown. Notice how the weather is moving southeast into Florida in the early part of this animation and then it suddenly turns around and moves to the north as Irma arrives. Notice in this animation how the storm moves northwest across Florida from the East Coast to the West Coast. That has shown up today. And of course this is just a forecast.

Part B. The Human and Economic Impacts of Recent Storms

B1. Irma Impacts

First Saint Martin especially the French portion of the Island.

Hurricane Irma destroys ‘95%’ of French part of St Martin

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Saint Martin September 6, 2017  Photo Credit. Lionel Chamoiseau/AFP/Getty Images

B2. Harvey Meteorological Summary (For Analysis Purposes Mainly)

Final NOAA Harvey Advisory.

POST-TROPICAL CYCLONE HARVEY ADVISORY NUMBER 53 NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1100 AM EDT SAT SEP 02 2017

POST-TROPICAL CYCLONE HARVEY CONTINUES TO WEAKEN…

SUMMARY OF 1100 AM EDT…1500 UTC…INFORMATION

LOCATION…38.1N 84.9W ABOUT 20 MILES…30 KM…WNW OF LEXINGTON KENTUCKY ABOUT 60 MILES…100 KM…ENE OF FORT KNOX KENTUCKY MAXIMUM SUSTAINED WINDS…15 MPH…25 KM/H PRESENT MOVEMENT…NE OR 045 DEGREES AT 5 MPH…8 KM/H MINIMUM CENTRAL PRESSURE…1013 MB…29.92 INCHES

WATCHES AND WARNINGS

FLOOD WARNINGS AND ADVISORIES ARE ONGOING SCATTERED THROUGHOUT EASTERN TEXAS…THE LOWER MISSISSIPPI VALLEY…TENNESSEE VALLEY…AND THE LOWER OHIO VALLEY.

DISCUSSION AND 48-HOUR OUTLOOK

AT 1100 AM EDT…1500 UTC…THE CENTER OF POST-TROPICAL CYCLONE HARVEY WAS LOCATED NEAR LATITUDE 38.1 NORTH…AND LONGITUDE 84.9 WEST. HARVEY CONTINUES TO WEAKEN AND IS EXPECTED TO DISSIPATE OVER THE MID-UPPER OHIO VALLEY BY TONIGHT ALONG WITH ANY LINGERING HEAVY RAIN AND RUNOFF THREAT DIRECTLY RELATED TO THE CIRCULATION. HOWEVER, A SEPARATE AREA OF LOW PRESSURE DEVELOPING OVER THE MID-ATLANTIC REGION AHEAD OF HARVEY WILL INTERACT WITH ITS REMNANT MOISTURE PLUME TO PRODUCE AS MUCH AS 1 TO 2 INCHES OF RAIN OVER THE NORTHEAST THROUGH SUNDAY.

HAZARDS AFFECTING LAND

RAINFALL…RESIDUAL FLOODING WILL CONTINUE IN AND AROUND HOUSTON, BEAUMONT/PORT ARTHUR/ORANGE, AND EASTWARD AROUND THE LOUISIANA BORDER THROUGH THE WEEKEND. DO NOT ATTEMPT TO TRAVEL IN THE AFFECTED AREA IF YOU ARE IN A SAFE PLACE. DO NOT DRIVE INTO FLOODED ROADWAYS.

NEXT ADVISORY

THIS IS THE LAST PUBLIC ADVISORY ISSUED BY THE WEATHER PREDICTION CENTER FOR THIS SYSTEM. PLEASE REFER TO YOUR LOCAL NATIONAL WEATHER SERVICE OFFICE FOR FURTHER INFORMATION ON THIS STORM.

FORECAST POSITIONS

INITIAL 02/1500Z 38.1N 84.9W

12HR VT 03/0000Z 39.8N 82.3W…POST-TROP/EXTRATROP

24HR VT 03/1200Z…DISSIPATED

Harvey Final Reported Precipitation Totals as of 11AM EDT September 2, 2017. There is no longer a separate site that I know of that provides update totals and they will no longer be in the WPC Updates so most likely this will be the final update of this information. We may add local updates if significant.

And then Additional States were Impacted.

New States being Impacted

Second Set of States Impacted (This data is as reported on Thursday 10 PM August 31.

Initial States Impacted (These totals are no longer being updated so they were correct as of 10 AM CDT Wednesday August 30).

Below is the last reported Track. There are no further updates of the track but you can tell the track by other graphics that I have included. Also the track is describe in the discussion which is up to date. We are now at the end of the reported track so this graphic is mostly of historical significance now.

Interesting way to view the precipitation pattern in the Houston area.

B2: Harvey Impacts

Economic Impacts.

The usual impacts of a disaster are first very negative and later very positive and essentially reflect Keynesian Economics. Unfortunately the first phase comes first and it can be very heartbreaking. One clue to how this might work out is provided by this excellent article.

More Than 50 Percent Of Properties In Houston At High And Moderate Risk Of Flood Are Not In Designated Flood Zones

First Report on number of homes damaged. Source: Market Watch

About 100,000 homes were damaged by Hurricane Harvey, President Donald Trump’s Homeland Security Adviser Tom Bossert told reporters on Thursday. Speaking at the White House, Bossert said the administration would soon ask Congress for an initial round of emergency funding to aid relief efforts. He said a second request would be made after getting more information.

Total Residential Insured And Uninsured Flood Loss For Hurricane Harvey Between $25 Billion And $37 Billion Approximately 70 Percent Of Flood Damage Is Uninsured

Oil Refinery Impacts

At the Beaumont-Port Arthur Airport, 26.03” of rain fell on Tuesday, which is more than double Beaumont’s previous calendar-day record of 12.76″ on May 19, 1923, in records going back to 1901. Between 10 pm last night and 1 am this morning, 11.86” fell. So far on Wednesday, 4.71” has been reported (as of 11 am CDT), bringing their 5-day storm total rainfall to a staggering 47.98”. The intense rains caused extreme flash flooding that inundated all of Port Arthur, according to Mayor Freeman, who showed a video this morning of the inside of his flooded house on his Facebook page. Port Arthur is the site of the nation’s largest oil refinery, which was forced to shut down due to the floods. The nation’s second-largest refinery, in Baytown, TX, was also forced to shut down yesterday, due to flooding-induced roof damage. In all, at least 12 refineries are currently offline due to Harvey. Source: Weather Underground Category 6  Click to Read Full Article

From this Geopolitical Futures article

The following is from our initial assessment Saturday afternoon. We will attempt to provide an organized assessment rather than streaming news reports as they come it. There is so much reporting that streaming these reports would mostly duplicate the traditional news services. So we will attempt to consolidate the information and provide a somewhat comprehensive analysis. 

Concern about Facilities that Depend on Cooling.

Arkema: No way to prevent explosion at flooded Texas chemical plant  Click to read more

Well it seems the report unfortunately was timely as this chemical plant has had explosions. You may be able to read about it here (you may hit a paywall not sure).

This is what we reported Saturday afternoon. There are many pictures showing flooding and other damage that we could show now.

Some of the graphics are very disturbing. But first we want to put this storm into perspective. This graphic was sent in by the NWS in Jackson Kentucky but was probably originally prepared by PBS.

It shows that very wet events are not unknown to Texas so we hope they are prepared to deal with this one.

This is a photo shown on the Blog Category 6; Image Credit is Joe Raedle/Getty Images.

Rockport is about 40 miles Northeast of Corpus Christi and presumably exposed to the strongest winds which are often in the NE quadrant of the storm. Harvey’s winds declined rapidly so we should expect that wind damage now will be restricted to tornadoes which can be very deadly. The main story here will be the flooding.

Another Rockport photo

More photo coverage of Rockport can be found here. For some reason the photo credit that is on the photo in the article does not show up when I display the photo separately. It is Brian Emfinger/LSM

We should expect that damage reports may come in slowly since may areas have been evacuated and the media may not be allowed in until the areas are deemed to be save from down power lines etc.

Tornadoes will cause a lot of damage. Right now they seem to be happening in the Cypress Area Northwest of Houston while in Houston flooding has been significant.

Source: Houston News KHOU

Same source for photos below: KHOU with the first photo credited to Kyra Respress.

and one more.

So far the reports of injured and deaths are amazingly low. That might change.

This is an excellent report from the Daily Mail in the UK – Lots of photos.

What Happens Next

It is important to understand that natural disasters often occur over a period of time, not instantaneously.

A good example is the rising of rivers which then overflow their banks and cause damage many hours and even days after the advent of a widespread storm. It takes time for this to happen and with Harvey we have a storm that is likely to provide the time for such subsequent events. Below, from NOAA, is a forecast for the San Bernard River. It is already at flood stage. Not sure how the river can rise to 35 feet once the level is so high that it can no longer be confined by the river banks but the graphic may be intended to show the severe level that is predicted. (If the normal level is x feet below the average river bank height, then all land within 35-x feet in elevation above normal water level will be flooded.)