Tropical wave into the SW Gulf... Weak "Erin" far E. Atlantic.....Weak low pressure has moved into the SW Gulf. Thunderstorms have continue to wax & wane as the wave is already showing signs of having to battle the shear that's 20-30 knots across much of the Gulf. The convection is stretched out...elongated parallel to the surface trough that's attached to the wave/weak low.
Forecast models are in pretty good agreement that the wave will remain only a surface trough as it moves northwest & north. This would take the wave into Mexico & Texas over the next few days increasing rain & storms, but that's about it. Some weak surface development is still not out of the question. Tropical moisture will continue to flow northward into the Gulf Coast region enhancing an already "juiced up" air mass. Widespread heavy rain will fall from Texas east to Fl.For the First Coast .
... my forecast remains unchanged
** tropical moisture is surging north leading to the potential for periods of heavy rain through today....& to a somewhat lesser degree Sunday but still some heavy rain all the way through the end of the weekend.
** this scenario has little to do with the tropical wave & much more to do with the surge of tropical moisture + a weak stationary front nearby (see surface weather chart below) + an upper level trough
** total rainfall since Wed. will exceed 6" in some places through Sun. & could reach a foot in some of the hardest hit areas(!), mainly across SE Georgia.
** a few strong to severe storms will occur -- related to the upper trough & not so much the tropical wave.
"Spaghetti plots" (forecast models) courtesy the S. Fl. Water Management District:
Large areas of dry mid & upper level air (black & rust colored areas on the water vapor satellite image below) remains over the Central Atlantic & has started to -- once again -- spread into the Caribbean. Overall conditions remain unsuitable for significant tropical development as shear generally remains high too. There has been moistening over the Eastern Atlantic & some forecast models are indicating tropical development in the far Eastern Atlantic (besides "Erin") during the last week or so of Aug.
Shear is strong over much of the Atlantic Basin -- as can be seen below -- exceeding 30 knots over large parts of the Caribbean...exceeding 40 knots over the Central Atlantic....& 20+ knots over parts of the Gulf of Mexico....
"Erin" is struggling over the far Eastern Atlantic. Conditions will remain marginal at best -- dry air & strong shear -- the farther west "Erin" goes which should cause the cyclone to eventually weaken even more & likely dissipate. It does not look like "Erin" can survive a Transatlantic trip nor will steer currents -- as it appears now -- allow such.
A pretty healthy tropical wave has moved off the coast of Africa. Forecast models again show initial development but then the system is stymied courtesy the hostile conditions that remain entrenched over the Central & parts of the Eastern Atlantic.
Speaking of the tropics...as I mentioned in a post a couple of weeks ago...Coastal University has jumped into the seasonal hurricane forecasting business (circus?). Coastal has just issued an update:
CONWAY, S.C. – The most likely scenario for the remainder of the 2013 hurricane season is that at least one major hurricane is predicted to make landfall on the East Coast and none is projected for the Gulf Coast, according to the latest predictions released today by the HUGO Hurricane Landfall Outlook Program, a new hurricane model system developed by scientists at Coastal Carolina University.
“It will be busier than normal on the East Coast, with one, possibly two, major hurricanes likely to make landfall,” said Len Pietrafesa, one of the lead scientists on the HUGO team. “The Gulf Coast will not see as much action as usual in terms of hurricanes making landfall, according to our outlook.” The factors that are used in the probabilistic scheme were updated in July and early August and the changes in those factors accounted for the changes in several of the prediction probabilities.
Two to four major hurricanes are expected to form.
Category April Outlook June Outlook July Outlook August Outlook Historical Average
TS 14 (13-15) 16 (14-18) 15 (14-17) 16 (15-18) 11.0
NH 7 (6-8) 8 (6-9) 8 (6-9) 8 (7-9) 6.2
MH 3 (3-4) 3 (3-4) 3 (3-4) 3 (2-4) 2.7
ECLF 1,2,0 1,0,2 1,2,0 1,2,0 0.65
GMLF 1,2,0 1,2,0 1,2,0 0,1,2 0.95
TS = named storms per season; NH = number of hurricanes; MH = major hurricanes (category 3 or higher); ECLF = number of landfall hurricanes on the Atlantic seaboard; GMLF = number of landfall hurricanes along the U.S. Gulf Coast. The number of landfalls is given as a probability in order of decreasing likelihood in three stages: most likely, second most likely and third most likely.
The Hurricane Genesis and Outlook (HUGO) project was established recently by CCU’s College of Coastal & Marine Systems Science. The new model differs from most other hurricane prediction instruments in that it offers landfall probability information. In addition to the seasonal outlook, the model system will predict the track and intensity of any incoming hurricane five days away from landfall. This latter capability will reduce the “cone of uncertainty” and provide much improved information to emergency management officials in their logistical planning in the event of evacuations.
The HUGO hurricane seasonal outlook model is based on calculations of 22 climatological factors encompassing oceanic, atmospheric and terrestrial activity. The model also considers detailed statistical data from previous Atlantic hurricanes going back to 1950, a methodology that has produced highly accurate track predictions in hindcasting tests conducted by the team at CCU.
HUGO outlook reports are issued beginning in April and are updated periodically during the season as new data becomes available from NOAA and other organizations.
The new model was developed by a group of climatological scholars of international standing led by Pietrafesa, former chair of the National Hurricane Center External Advisory Panel and now a member of the faculty of CCU’s School of Coastal & Marine Systems Science. Other members of the CCU team are Shaowu Bao, a computational, deterministic numerical modeler specializing in meteorology and oceanography; Tingzhunag Yan, a meteorological oceanographer with a background in statistical modeling of climate and weather systems; and Paul Gayes, director of the School of Coastal & Marine Systems Science.
Click ** here ** for more info.