NCAR WRF-ARW Retro Forecasts for Selected North Atlantic TCs

WRF Retro track and intensity forecasts

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Storms that developed east of 45W:


Ike (2008):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts: The dip in intensity near day 5 (relative to genesis) was not handled well by the initial run, but the intensity forecasts were quite good thereafter. There was a slight southerly track bias in the forecasts initialized when Ike was east of 65W. Later on, some members recurve Ike too early in the eastern Gulf of Mexico, while most members take Ike to TX coast with a slight southerly bias in the landfall location.
Notes on SAL: There is evidence of the SAL north and northeast of Ike prior to 4 September, but Ike seems fairly well protected.

Ana (2009):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts: Model forecasts consistently overdeepened Ana three days after genesis. Track forecasts from 0000 UTC 12 and 13 Aug were squirrely initially, then took Ana on a northwestward track. Problem is that Ana moved straight west and weakened. Why was storm motion so far off? And was this related to the significant intensity issues later?
Notes on SAL: The SAL looks for be fairly abundant across the MDR.

Bill (2009):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts: Overall the forecasts for Bill were excellent. The first couple of 1800 UTC forecast cycles were slow to intensify Bill, but rapidly caught up thereafter. A clear rapid intensification signature. Later forecast cycles at all times were slow to weaken Bill. The first two 0600 UTC and first 1800 UTC forecast cycles were slow to recurve Bill.
Notes on SAL: Major league SAL across the MDR throughout the period; interaction with Bill.

Fred (2009):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts: The model forecasts, especially the first few cycles, were slow to develop Fred and also slow to weaken Fred. The intensity curves are out of phase. The first 1800 UTC cycle was particularly slow. The first couple of forecast cycles had right-of-track errors, and the sharp anticyclonic turn at the end of Fred's track was underdone.
Notes on SAL: The SAL product is not available early in Fred's life cycle, but by 11-12 Sept there is little evidence of a SAL over the Atlantic basin. The dry air near Fred was likely associated with the upper-level trough to the northwest that resulted in increased shear over Fred.

Danielle (2010):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts: Most members had a weak bias through Danielle's intensification to day 6, and most of the later forecast cycles were slow to weaken Danielle. The second 1800 UTC cycle is of interest in that intensification was much delayed (by 4 days!). The first 0000 UTC forecast cycle has a right-of-track error and intensified Danielle too early (by day 2). The first three 1800 UTC forecast cycles has right-of-track errors. Overall the track forecasts were good, however. The model even handled the sharp nature of Danielle's recurvature.
Notes on SAL: Well-defined SAL present across MDR. Danielle looked to stay protected from SAL early on...then blasted through the SAL during recurvature.

Earl (2010):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts: Forecasts initialized up to the point of recurvature had a distinct right-of-track bias...tried to recurve Earl too early. We noticed this in real-time even with the global models. There were issues with the track forecasts for the first 0000, 1200, and 1800 UTC forecast cycles...they take Earl into South America. An issue with the tracker? The intensity forecasts had varying success. The later forecast cycles did quite good. The earlier forecasts initialized prior to 28 August - when Earl was enveloped in the SAL - failed to develop Earl at all.
Notes on SAL: Earl was enveloped in a robust SAL through 28 August.

Fiona (2010):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts:The forecasts for Fiona were horrible. Major track errors throughout. The models refused to recurve Fiona and kept the system on a westerly course into the Caribbean and Gulf of Mexico. Even the forecast cycles initialized during recurvature refused to recurve Fiona. This must be related to issues with the synoptic-scale flow pattern, which was being influenced by the outflow from Earl. Its the old interacting TCs problem. The intensity forecasts were equally bad. The model forecasts, especially the first few cycles, missed the initial deepening to a modest tropical storm by day 2. The model forecasts then over-deepened Fiona after day 2. This overdeepening is probably related to the major errors in track forecasts.
Notes on SAL: Widespread SAL over MDR. Fiona enveloped in SAL through 31 August.

Gaston (2010):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts: The track forecasts look really messed up. Tracks look squiggely and take the system all over the place. Need to double check to make sure tracker was working properly. The initialization from 0600 UTC 1 Sept takes Gaston eastward back to the African coast. I have no reasonable explanation for this yet. All of the model intensity forecasts were underdone...which is remarkable considering how weak Gaston was to begin with. The first 1200 UTC cycle is the only model forecast to briefly intensify Gaston to a 35 kt tropical storm.
Notes on SAL: Widespread SAL over MDR. Gaston enveloped in Dry Air/SAL.

Igor (2010):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts: The track forecasts for Igor were excellent; they handled the recurvature of Igor much better than for Earl and especially Fiona. A couple of runs recurved too early or too late, but that was not the norm. The intensity forecasts were good, and even got Igor's rapid intensification albiet a little slower than observed. The model forecasts also has a slight weak bias during Igor's most intense phase, and were slow to weaken Igor. (Is the slow weakening of systems in the model a common problem??) The second 0600 UTC and first 1200 UTC cycle only weakly developed Igor.
Notes on SAL: Weak evidence of SAL over MDR north of Igor, but does not seem relevant.

Julia (2010):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts: The first forecast cycle at each time had a north track error, but the track forecasts thereafter were good. The intensity forecasts for Julia were way off. Many of the forecasts hinted at the rapid deepening observed in the day 2-4 range, but it was way underdone. Almost all of the forecast cycles after the initial cycles failed to rapidly weaken Julia and kept it as a strong TC late in the period.
Notes on SAL: Dry air is present northwest of Julia throughout the period in conjunction with the upper-level trough. A major league SAL surged westward off of Africa starting on Sept 14, with potential interaction with Julia.

Lisa (2010):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts: The first 3-4 forecast cycles at each time had significant left-of-track errors and completely missed (or was underdone) the sharp right turn early on in Lisa's track. The first two forecast cycles over-deepened Lisa too early, while most forecast cycles kept Lisa too strong for too long. Again, this seems like a common problem.
Notes on SAL: No evidence of SAL. Dry air on northwest side of Lisa late in life cycle...looks to be associated with upper-level trough.

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Storms that developed in eastern Caribbean and central North Atlantic:


Erika (2009):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts:
Notes on SAL:

Fay (2008):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts:
Notes on SAL:

Gustav (2008):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts:
Notes on SAL:

Hanna (2008):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts:
Notes on SAL:

Tomas (2010):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts:
Notes on SAL:

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Storms that developed in western Caribbean and Gulf of Mexico:


Claudette (2009):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts:
Notes on SAL:

Hermine (2010):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts:
Notes on SAL:

Ida (2009):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts:
Notes on SAL:

Karl (2010):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts:
Notes on SAL:

Matthew (2010):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts:
Notes on SAL:

Nicole (2010):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts:
Notes on SAL:

Paula (2010):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts:
Notes on SAL:

Richard (2010):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts:
Notes on SAL:

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Storms that developed in western North Atlantic:


Danny (2009):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts:
Notes on SAL:

Otto (2010):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts:
Notes on SAL:

Shary (2010):
4-Panel Synoptic Charts
SAL/Dry Air Product (source: University of Wisconsin-CIMSS)
0000 UTC Init Track Intensity
0600 UTC Init Track Intensity
1200 UTC Init Track Intensity
1800 UTC Init Track Intensity
Notes on forecasts:
Notes on SAL:

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