SEVERE WEATHER THREAT / TROPICAL WEATHER FORECAST SYNOPSIS…ISSUED MAY, 13, 2015…11:10 A.M. EDT

SEVERE WEATHER RISK: SLIGHT
TROPICAL STORM FORMATION:  NONE

ALL forecasts contained on this site,  are based on my analysis and knowledge of various forecast tools, including information contained in NHC products, and are not copies from any other entity.

Good day everyone!

The SPC has designated a SLIGHT risk of Severe Thunderstorms for PORTIONS OF S TX…

There is a MARGINAL risk ELSEWHERE FROM S TX TO RED RIVER REGION OF SWRN OK/NW TX…and for PORTIONS N-CENTRAL HIGH PLAINS…

SPC DAY 1 CONVECTIVE OUTLOOK DISPLAY (LINKED)
day1otlk_1300

Based on analysis of the outlook text, and solution from the NAM-WRF model via F5 DATA Severe Weather software, the most likely threat will be in the form of hail and damaging wind gusts for the Northern High Plains area.  This will also hold true for TX., however certain parameters do indicate a good probability for tornadoes to develop with the strongest supercells.  Indices analyzed indicate the best chance for tornadic activity to occur within the outlined area today, probably along the lines of afternoon through early evening hours.  The most likely area for tornadoes today should be within the slight risk outline, albeit forecast sounding data tends to suggest a fair prob. of tornadic activity within the marginal risk area.

F5 DATA NAM-WRF BEST TORNADO PROBABILITY
f5nam.tor1

Residents in the risk ares should monitor NOAA Weather Radio, and local NWS statements and advisories this afternoon and evening.

The SPC further indicates severe weather risks through Sunday, with a MARGINAL risk in the current Day 2 Outlook, an ENHANCED risk on Friday, and a probability for SAT / SUN.  Please refer to, and click the linked graphic for these forecast risks.  I have to work over the next 3 days, so please use the link to your advantage.

SPC CONVECTIVE OUTLOOKS HOME PAGE (LINKED)
activity_loop

The following graphics are linked to their respective sites.  You will need to click on them for the most current information.

SPC CONVECTIVE WATCH DISPLAY
validww

SPC MESOSCALE DISCUSSIONS DISPLAY
validmd

NWS DOPPLER RADAR
latest_Small

NWS HAZARD, WATCH AND WARNING DISPLAY (LINKED)

TROPICAL WEATHER SECTION:

The tropics remain quiet as expected for this time of the year.

SSEC GEOSTATIONARY SATELLITE VISIBLE LOOP

NOAA ATLANTIC OCEAN WIDE SATELLITE LOOP

Analysis of global models this morning indicates the GFS has dropped its solution of an area of low pressure developing in the southern Bahamas in about 12 days.  Satellite loop imagery yesterday evening did show cyclonic turning in cloudiness over Cuba, however vorticity maps indicate this is associated with a mid-upper level low.

In reviewing certain things this morning, it is pretty apparent El Nino has taken hold. Displayed are a couple of SST anomaly charts clearly showing El Nino in the Equatorial Pacific.

NOAA-NESDIS SST ANOMALY CHART
anomnight.5.11.2015

UNISYS SST ANOMALY CHART
sst_anom

You can also pick out how much cooler the Atlantic MDR anomalies are, and how we have a reversal on the Atlantic Tripole.  Looking at the anomalies in the Gulf of Mexico (GOMEX) and off the SEUS, as stated in my pre-season outlook, close in development will have to be looked for during the early part of the season, which as we just saw with ANA, lends credence to a U.S. landfall.

Based on analysis of the SOI this morning, it still remains strongly negative, indicating below-normal air pressure at Tahiti and above-normal air pressure at Darwin.  This allows for trade winds over the Equatorial Pacific to blow from west to east, allowing for the warmer waters (sub-surface) in the western pacific to push east toward the coast of South America, which make their way to the surface once hitting the coast.  As long as the SOI remains in this phase, the current El Nino will remain in place.  This is just one negating factor for the Atlantic Hurricane Season.

SOUTHERN OSCILLATION INDEX (SOI)

As stated, the Atlantic Ocean MDR remains much cooler than average.  The one factor, other than the SAL outbreaks we have noticed already, is the NAO has been mainly in a positive phase.  This implies stronger easterly trades, causing greater evaporational cooling, and upwelling off the African coast.

The current NAO forecast does indicate a possible weakening of the NAO, for a period of about 2 weeks, which could allow for some slight warming in the Atlantic.

NAO FORECAST CHARTS
NAO

nao.sprd2

The forecast outlook for the MJO, based on the dynamic modeling, forecasts a weak signal for the remainder of the month.  Should none of the above items and values change, or change very little, we should be looking at a below average season, as forecast.  As we get deeper into the hurricane season, I will be attentive to any changes that may occur.

ECMF_phase_51m_full

Have a blessed day!

T. F. “STORM” WALSH III GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST / SEVERE WEATHER SPECIALIST MEMBER WEST CENTRAL FLORIDA AMS
CoCoRAHS OBSERVER

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About palmharborforecastcenter

I am a Tropical Forecast meteorologist, providing hurricane forecasts during the Atlantic Hurricane Season. I retired from the U.S. Coast Guard in July of 2001. Meteorology became my passion in high school, and I have continued my educational background in meteorology since 1996, when I undertook the study of Tropical Meteorology. While working toward my degree, I had to unexpectedly withdraw from college due to my oldest sons medical reasons. I do however, meet the educational criteria of the AMS to be recognized as a meteorologist. Studies include, but are not limited to the Navy Aerographers Mate course, Naval METOC meteorology course, Meteorology 2010 Sophomore level course while attending St. Petersburg College, Clearwater, FL., Basic Forecasting course for operational meteorologists from Rapid WX, meteorology institute, a four month meteorological internship, and extensive research on numerous meteorological topics such as the MJO, NAO, satellite imagery interpretation, etc. I have been forecasting Tropical Weather (Tropical Storms and Hurricanes) since 1996, with my main client being three different Coast Guard Commands.
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8 Responses to SEVERE WEATHER THREAT / TROPICAL WEATHER FORECAST SYNOPSIS…ISSUED MAY, 13, 2015…11:10 A.M. EDT

  1. originallt says:

    Hi Storm, glad to see you must be busy at work. Hope you and your family are well.–Was 83F yesterday here in Stamford, today , right now at 12:59pm, it’s 62F. A back door cold front pushed thru overnight. Should retreat as a warm front later tonight, , about 75F tomorrow, But a cold front from the West approaching, with showers and T. Storms possible all day, on and off Tuesday, setting us up for 4-5 days of nice spring weather, with highs generally 70-75F, lows 50-55F at night.

  2. dellamom says:

    Thank you, Storm. That’s a lot of information to digest, but you make it easily understandable even to people like me who have not had any weather training. Prayers to all to my west.

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