TROPICAL CYCLONE FORMATION: NONE
Disclaimer: This site is not affiliated with the National Hurricane Center, Storm Prediction Center, or National Weather Service. ALL forecasts herein are the result of my analysis, and I am solely responsible for the content.
(T. F. “Storm” Walsh III)
For those who have donated to my site, your help has been greatly appreciated. For those not aware, donations to my site help me offset my personal out of pocket expenses…such as some of the model maps you view on here, are only available due to my subscription to the corresponding site. The F5 Data maps I post, also another out of pocket expense (monthly subscription). Updates to software (weather related), and costs for my domain name are also out of pocket to me. To donate, please click the DONATE button to the right. Any help you provide is immensely appreciated! Although it may seem I am not here and working in support of your donation, I have to work my forecasting time around my ever changing work schedule.
CURRENT 2016 TROPICAL CYCLONE TOTALS:
TOTAL STORMS: 4
INTENSE HURRICANES: 0
StormW’s Seasonal Hurricane Forecast:
TOTAL STORMS: 14-16
INTENSE HURRICANES: 3-4
Good evening everyone!
Still quiet in the tropics again. Satellite imagery hasn’t really changed much since the last time I updated. It is noted there is an increase in activity over on the extreme EPAC side.
This is pretty much expected, given that the majority of upward motion, or vertical velocity is concentrated over that particular area.
REAL TIME AND FORECAST 200 MB VELOCITY POTENTIAL ANOMALIES
There is a discrepancy between the real time MJO filtered 200 mb velocity potentials, as compared to the near-real time NCEP product, which shows downward motion over the Atlantic.
Eastern Atlantic satellite imagery indicates another tropical wave getting ready to exit the African continent, and the EUMETSAT shows an increase in wave activity over the African continent.
Given the current situation of SAL (dust), and a still rather moderate subtropical ridge in place, you’ll note dry air over most of the Atlantic, and African dust (which is noted in the CIMSS true color satellite still, and also, in the EUMETSAT dust channel…dust on the EUMETSAT shows up as pink and magenta colors). This combination of subsidence (sinking air) and dust, is creating a fairly stable atmosphere over the MDR.
Analysis of the global models do not indicate any development over the next 5-7 days. However, by this time, or just beyond mid month, there could possible be a change. Remember what I said about the position and strength of the subtropical ridge. It has been pretty much located further south than we usually see. Even though the NAO has been moderately negative over the past week, surface pressures are hanging around 1026-1027 mb. I have found in past forecasting experience, that 1024 mb or below seems to be one key, in that the trade winds slow down at the surface. I performed an analysis of current and forecast 900 mb winds, which are very close to the surface, and they have been running 20-30 knots. This has a tendency to cause upwelling for one, of cooler water near Africa, and causes the evaporation rate near the ocean’s surface to be too strong, dissipating heat and spreading it out, instead of allowing it to be focused more in one place or column. So, a little more weakening of the ridge can be twofold, in allowing for decreased subsidence, and decreased evaporation rate at the surface. Now, as I mentioned, we may see a change coming in around day 7-10. I call him my colleague, as he’s taught me well with his videos, which is where I picked up a lot of my tropical forecasting skills. Joe Bastardi from Weatherbell Analytics mentioned something which I already knew, but he beat me to it, as this is the first I’ve been able to update.
Remember, I just spoke of the position of the sub-tropical ridge. Well, based on the GFS and especially the ECMWF, it appears a pattern change is in order. Based on MSLP and MSLP anomalies, current and forecast out to 5-10 days, the ridge is supposed to shift more toward the north and west, which will displace the current pattern of lower pressure which is just and, and north of 30N latitude, with the ridge sliding into this position. This will move it away from its close proximity to Africa. With this pattern occurring (if it does), pressures will be rising further north,which means one thing…pressures will be allowed to lower near Africa and over the eastern portion of the MDR region. This doesn’t necessarily mean development will occur, but it increases the probability of development occurring.
You’ll also note in the maps of the ECMWF and GFS at 216 hours, sort of what I call a “tongue” extending from NE to SW near Africa…this is representative of the west Africa monsoon circulation appearing.
Elsewhere, Tropical Storm formation is not expected during the next 7-10 days.
T. F. “STORM” WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST /SEVERE WEATHER SPECIALIST
MEMBER WEST CENTRAL FLORIDA AMS