Hurricane Ida In Gulf with 100 mph winds; Will Be Weakening at landfall in US


IdaRainbow

Hurricane Ida Satellite Loop (rainbow IR click image for most recent)

See update on pending Ida landfall near Mobile Bay. For latest satellite, radar, forecast track, spaghetti model CLICK HERE

ida_cancun_radare

Cancun Radar of Hurricane Ida Passing Through Yucatan Channel

Hurricane Ida is moving through the Gulf of Mexico and the Hurricane Ida Forecast Track takes it inland near Pensacola, Florida.  A Hurricane Watch has been issued for the northern Gulf Coast and  Hurricane Warning flags have been hoisted from Pascagoula, MS to Indian Pass, FL which is near Applicachicola.   A Tropical Storm Warning is in effect westward to New Orleans and eastward to Aucilla River, FL.  For the past two days, I have been suggesting that the more conventional solution should be considered rather than the forecast track established by many models which called for the storm to loop back out to sea.  In many regards, it made no sense.  The National Hurricane Center went along with the consensus modeling but I figured the models would eventually come around, and they have.  Yesterday, I had observed the satellite imagery and concluded that it was certainly possible for Hurricane Ida to be something stronger than the forecast intensity of 70 kts.  By late Sunday afternoon, Hurricane Ida had sustained winds of 105 mph.  As it came through the Yucatan Channel, Cozumel Radar showed very distinctive banning and a decen, though not perfect, circulation structure.    Even though Ida spent 48 hours over land, it is now stronger than it ever has been.

SSTatl

Gulf of Mexico Sea Surface Temperatures (SST) Not Conducive to Supporting Tropical Cyclones

I would think that Hurricane Ida does not have much more time to get stronger.   In the first place, if you look at the sea surface temperature analysis, you will note that the lighter orange shades in the Yucatan Channel correspond with sea surface temperatures something less than 30 degrees C but more than the minimum required of 28.5 C.  As the shading progresses farther north, it goes darker and darker toward brown.  That is representing falling water temperatures and it would appear to me that when you look at the central Gulf of Mexico about even with Tampa, the temperatures at the surface are below 28 C, which means that Ida will begin to die then.  By the time you get to about 150 miles off the US Gulf Coast, water temperatures are in the lower 20’s C.  Remember, we’ve had several strong cold fronts in the past few weeks that have reduced water temperatures in the shallower waters. 

latest72hrs

Atlantic Total Precipitable Water Loop (click image for most recent)

The other factor in Hurricane Ida’s demise will be strong southwesterly shear ahead of a trof that is moving across the Continental United States.  That just happens to come into play in about the same spot as where the water temperature falls before critical levels.  So, while that upper wind has been serving to enhance the northern outflow of Ida and helped enhance its intensity, it will be the same factor that will help kill it.  By late Sunday, the hurricane hunter aircraft noted a central pressure of 976 mb, which is fairly impressive. However, a later recon mission revealed the pressure had risen to 980 mb, there was an 8 mile circular eye that was open to the east.  So, the Sunday night observations may be an early indication that Ida has seen its best days and the decline has already begun.   But, then again maybe not because the flight level winds were higher on this pass from the last going from a maximum flight level (700 mb) wind of 94 kts to 108 kts.  It’s kinda interesting that the hurricane hunters reported hail on their latest venture into Ida.  In any event,  in contrast to the most recent observations, the NAM, GFS and NOGAPS models have respective central pressure at landfall of 1004 mb, 1004 mb and 1009 mb.  That is pretty pedestrian and is indicative of just how far and how fast Ida is expected to fall apart.  It may indeed become extra-tropical.  That is really not an issue because that has more to do with the structure of the storm and wherever it makes landfall, residents can expect a storm surge, heavy rain and gusty winds. 

IDAtrack

Hurricane Ida Forecast Track (click for upates)

As I outlined the previous two days, it seemed likely that this guy would get caught up in the southwesterly flow ahead of the trof and be kicked to the northeast like any other low pressure area.  While it is falling apart and becoming a run-of-the-mill low, it will still be an area of low pressure and I think will act accordingly.  If it got completely absorbed, then it wouldn’t be a distinct low and therefore no longer an entity to be tracked.  In any event, everyone seems to me on board with a landfall in the US.  The NAM wants to take it into New Orleans on Monday night.  The GFS likes Monday night around Mobile or Pensacola while the NOGAPS likes Mobile/Pensacola but is looking for a Tuesday night landfall.  The NOGAPS solution is probably more accurate as to timing and location but I bet the GFS and NAM idea of a 1004mb low is probably a better call than the NOGAPS 1009 mb suggestion.  The ultimate truth of the landfall time will probably be sometime in between the NOGAPS and GFS/NAM timing.  I’ll vote for Tuesday early afternoon.

Bottom line is this.  Hurricane Ida has been tabbed as a 90 kt hurricane with gusts to 110 kts based on the latest recon data but will be hard pressed to maintain its hurricane status at landfall.  In fact, there it may be likely that it will be considered extra-tropical.  So what.  North Florida, South Georgia, South Alabama and even perhaps South Carolina can expect gusty winds and heavy rain Tuesday into Wednesday as I would think the ultmate path may go from say, Pensacola to Savannah.  A cold front sweeps it all away and that will be the end of that by Thursday.  See the official discussion below the Hurricane Ida Spaghetti Model image that you can click on for the most recent update.

Ida Spaghetti

Hurricane Ida Spaghetti Model (click image for most recent)

HurricaneWarningmap

Hurricane Watch/Warning Map

000
URNT12 KNHC 082332
VORTEX DATA MESSAGE   AL112009
A. 08/23:04:40Z
B. 22 deg 47 min N
  086 deg 25 min W
C. 700 mb 2948 m
D. 80 kt
E. 355 deg 4 nm
F. 099 deg 103 kt
G. 359 deg 8 nm
H. 980 mb
I. 7 C / 3069 m
J. 17 C / 3054 m
K. 7 C / NA
L. OPEN E
M. C8
N. 12345 / 7
O. 0.02 / 1 nm
P. AF309 0411A IDA                OB 29
MAX FL WIND 108 KT NE QUAD 22:09:20Z
HAIL AND CONT LIGHTNING  N QUAD

WTNT41 KNHC 090301
TCDAT1
HURRICANE IDA DISCUSSION NUMBER  21
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
900 PM CST SUN NOV 08 2009

THE SATELLITE APPEARANCE OF IDA HAS CHANGED VERY LITTLE SINCE THE
AIRCRAFT DEPARTED THE HURRICANE JUST BEFORE 0000 UTC.  DURING THE
LAST COUPLE OF PASSES THROUGH THE CENTER THE AIRCRAFT MEASURED A
MAXIMUM 700 MB FLIGHT-LEVEL WIND OF 108 KT AND A SFMR SURFACE WIND
OF 84 KT. THESE DATA SUPPORT AN INTENSITY OF 90 KT.  ANOTHER AIR
FORCE PLANE IS SCHEDULED TO REACH IDA AROUND 0600 UTC.

THE LAST FEW AIRCRAFT FIXES PROVIDE A FAIRLY CONFIDENT INITIAL
MOTION OF 345/12…A LITTLE FASTER THAN BEFORE.  IDA IS FORECAST TO
CONTINUE MOVING NORTHWARD BETWEEN A MID/UPPER-LEVEL TROUGH OVER THE
WESTERN GULF MEXICO AND A MID/UPPER-LEVEL RIDGE OVER THE EASTERN
GULF OF MEXICO AND THE NORTHERN CARIBBEAN SEA.  THE TRACK MODELS
APPEAR TO BE IN A LITTLE BETTER AGREEMENT ON A NORTH-NORTHWESTWARD
TO NORTHWARD TRACK DURING THE NEXT 24-36 HOURS.  THE 12Z RUNS OF
THE ECMWF AND UKMET ARE A LITTLE WEST OF THE REMAINDER OF THE
GUIDANCE AND SHOW A TRACK NEAR EXTREME SOUTHEASTERN LOUISIANA.
DURING THE FIRST 24-36 HOURS…THE NEW OFFICIAL FORECAST IS NEAR
THE MODEL CONSENSUS AND THE PREVIOUS TRACK…BUT IS A LITTLE
FASTER.  AFTER LANDFALL ALONG THE NORTHERN GULF COAST…THE MODELS
TURN IDA EASTWARD THEN SOUTHEASTWARD AND THE NHC FORECAST FOLLOWS
SUIT…BUT DOES NOT SHOW AS SHARP A SOUTHEASTWARD TURN AS SOME OF
THE GUIDANCE INDICATES.  THE AIR FORCE ALSO FLEW A SURVEILLANCE
MISSION AROUND AND NORTH OF THE HURRICANE THIS AFTERNOON AND THAT
DATA SHOULD BE ASSIMILATED INTO THE 0000 UTC MODELS.

IDA IS FORECAST TO TRAVERSE COOLER WATERS…AND MOVE INTO A
COOLER AIRMASS AND INCREASING SHEAR DURING THE NEXT 24-36 HOURS.
AS THE CYCLONE APPROACHES THE NORTHERN GULF COAST IT WILL ALSO
LIKELY BEGIN EXTRATROPICAL TRANSITION.  HOWEVER…IT IS BECOMING
MORE LIKELY THAT IDA WILL RETAIN ITS TROPICAL CHARACTERISTICS
THROUGH LANDFALL.  THE INTENSITY GUIDANCE FORECASTS GRADUAL
WEAKENING AND ALL SHOW IDA AROUND HURRICANE STRENGTH AT LANDFALL.
THE OFFICIAL FORECAST IS IN LINE WITH THE GUIDANCE AND KEEPS THE
CYCLONE A HURRICANE WHEN IT REACHES THE COAST.  THIS HAS REQUIRED
THE ISSUANCE OF A HURRICANE WARNING FOR A PORTION OF THE NORTHERN
GULF COAST.

FORECAST POSITIONS AND MAX WINDS

INITIAL      09/0300Z 23.7N  86.7W    90 KT
12HR VT     09/1200Z 25.8N  87.5W    85 KT
24HR VT     10/0000Z 28.5N  87.7W    75 KT
36HR VT     10/1200Z 30.5N  87.1W    65 KT…INLAND
48HR VT     11/0000Z 31.2N  85.8W    40 KT…EXTRATROPICAL
72HR VT     12/0000Z 30.5N  82.0W    30 KT…EXTRATROPICAL
96HR VT     13/0000Z…DISSIPATED

$$
FORECASTER BROWN

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