Disclaimer:  This site is not affiliated with the National Hurricane Center, Hurricane Hunters, Storm Prediction Center, or National Weather Service.  ALL forecasts herein are the result of my analysis, (to which you will see me at times, insert excerpts from various agencies due to the nature of the importance of the information) and I am solely responsible for the content.  As ALWAYS, follow the National Hurricane Center, National Weather Service, and your local Emergency Management officials for emergency decisions.  In addition, this is strictly a FORECAST OFFICE.  I CANNOT make decisions regarding travel plans, etc.  My purpose, is to provide you the information, based solely on information I analyze, and the accuracy of the information at hand of the time of analysis, so you may make informed decisions.
(T. F. “Storm” Walsh)

For those who have donated to my site, your help has been greatly appreciated.  If you are not aware, donations to my site help pay for subscriptions to sites I use as well as software updates, which provide all the models and information used in my forecasts.  To donate, please click the DONATE button to the right side of the page, or on the graphic of the dog.  Any help you provide is immensely appreciated!
DONATIONS ACCEPTED AND APPRECIATED

I will reiterate, my forecasts are based on the available information at the time of analysis, and are only as accurate as the information analyzed and the solutions provided.

Good day everyone!
The forecast center is closed on Sunday’s.

For residents under the significant hatched areas, PLEASE read the SPC outlook linked in the first SPC outlook graphic, and any updates after issuance of this synopsis…it could save your life.

As of this morning, the Storm Prediction Center has issued a MODERATE risk for severe thunderstorms for today’s outlook.  To view risks for the remainder of the week, please visit the SPC homepage:
https://www.spc.noaa.gov/

The current DAY 1 MODERATE risk includes SIGNIFICANT HATCHED areas. 
 
CURRENT DAY1 SEVERE WEATHER OUTLOOK
The Storm Prediction Center (SPC) has issued a MODERATE risk for severe thunderstorms in the current DAY1 Outlook: 
ACROSS PARTS OF CENTRAL MARYLAND…MUCH OF CENTRAL AND EASTERN VIRGINIA…CENTRAL NORTH CAROLINA AND ADJACENT PORTIONS OF SOUTH CAROLINA…

…SPC SUMMARY…
Fast moving thunderstorms may become widespread and accompanied by the risk for damaging wind gusts and a few tornadoes across the Mid Atlantic today. There is potential that a couple of storms could become capable of producing strong and long track tornadoes.
1300Z SPC DAY 1 SEVERE THUNDERSTORM OUTLOOK (LINKED FOR OUTLOOK TEXT)

TORNADO PROBABILITY

Probability of a tornado within 25 miles of a point.  Hatched Area: 10% or greater probability of EF2 – EF5 tornadoes within 25 miles of a point.
HAIL PROBABILITY

Probability of one inch diameter hail or larger within 25 miles of a point. Hatched Area: a 10% or greater probability of 2-inch diameter or larger hail within 25 miles of a point
DAMAGING THUNDERSTORM WIND PROBABILITY

Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point.  Hatched Area: a 10% or greater probability of 65 kt+ winds within 25 miles of a point.
CSU – MLP DAY1 PROBABILITY (CLICK FOR LARGER IMAGE)

NSSL ML DAY 1 PROBABILITY

DAY 1 PROBABILITY CONVERSION TABLE

SPC DISCUSSION EXCERPT:
…Southeast States…
An intense upper trough continues to deepen over the Mid MS Valley, with its associated surface cold front surging eastward across the Appalachians and into the Carolinas/Mid-Atlantic. An active line of thunderstorms is accompanying the front from GA into western SC/NC/VA. Low-level winds are very strong along and ahead of these storms, encouraging the risk of numerous severe wind gusts and embedded QLCS tornadoes along the line. Clusters of thunderstorms have been developing ahead of the line as well, in a moist and strongly sheared environment. These storms will also pose a severe/tornado risk through the day as the primary large-scale ascent arrives.

…Mid Atlantic States into NY…
Farther north, low-level moisture is a little more limited and CAPE values will be slightly lower. Nevertheless, intense low and mid level wind fields will be present across this region as the cold front approaches from the west. Thunderstorms are expected to strengthen through the late morning across west-central VA into central NY/PA and spread eastward to the coast by early evening. Forecast soundings across this area show very large low-level shear values that will favor the risk of widespread damaging winds and several tornadoes. Strong tornadoes will be possible – especially from MD southward where the greatest low-level moisture will be present.

The following maps are from NADOCAST for tornado and hail probabilities.  
12Z NADOCAST TORNADO PROBABILITY

12Z NADOCAST SIGTOR PROBABILITY 

12Z NADOCAST HAIL PROBABILITY 

12Z NADOCAST SIGHAIL PROBABILITY 

Based on my analysis this morning, severe weather was already in progress in the MARGINAL and SLIGHT risk outlines, and TORNADO WATCHES have been issued. Based on current forecast severe weather indices and current SPC outlook indicate severe thunderstorms may be possible from afternoon through early evening.  ALL severe risks are probable including isolated large hail, strong / long track tornadoes (EF2+) within the 10 – 15% HATCHED TORNADO areas.  Based on current forecast indices, these should remain within the (EF2 – EF3) intensity range.  Should EHI values increase during the day, an ISOLATED EF4 -EF5 tornado can not be ruled out.

THIS HAS THE POTENTIAL TO BECOME AN ISOLATED PDS (Particularly Dangerous Situation) and PDS TORNADO WATCHES could be issued later today into late afternoon / early evening. 

Based on analysis of model animations, the current outlook, and analysis of indices, the strongest convection and indices could occur approximately between 2:00 P.M. EDT MAR. 16 – 7:00 P.M. EDT MAR. 16.  Strongest / Maximum indices based on analysis appear to occur over the 10% and 15% SPC HATCHED TORNADO outlines.  Please visit the SPC homepage via the link provided for any changes to the forecast today:
https://www.spc.noaa.gov/products/outlook/day1otlk.html
CAPE VALUES FORECAST

DEW POINT FORECAST

Indices were analyzed from the NAM 3KM, HRRR 3KM, CIPS DETERMINISTIC, and SPC SREF model guidance.

The following were the forecast parameters and indices analyzed this morning.  Bear in mind, MAXIMUM indices recorded below are for the time of peak intensity.  Some indices meanings are posted below the indices themselves, and the NWS page containing a more extensive explanation can be accessed further on in the synopsis:
SBCAPE: 500- 2000 j/kg-1           
MLCAPE: 500 – 1200 j/kg-1    
MUCAPE: 500 – 2000 j/kg-1      
SRH 0 -1 km: 100 – 350 m2/s2  
SRH 0 -3 km: 250 – 500 m2/s2       
SRH EFFECTIVE: 100 – 300 m2/s2     
L. I.: -2 to -5                                            
SCP: 2 – 10                                  
STP: 0.5 –2.4
0 -6 km SHEAR: 60 kts – 70 kts         
EFF. SHEAR: 50 kts – 60 kts                 
MID LEVEL LAPSE RATE: 6.0C – 7.0C
DEWPOINT: 60F – 68F                                 
EHI: 0.8– 3.8                           
TOTAL TOTALS INDEX: 50C               
K INDEX: 26C to 33C                                          
SWEAT INDEX: 465– 525                    
THOMPSON INDEX: 28 to 38
CRAVEN – BROOKS INDEX: 10,000 – 30,000     

CAPE

ENERGY HELICITY INDEX

K INDEX

TOTAL TOTALS INDEX

STORM RELATIVE HELICITY

LIFTED INDEX

SWEAT VALUES

THOMPSON INDEX

Craven SigSvr Parameter:
The simple product of 100mb MLCAPE and 0-6km magnitude of the vector difference (m/s; often referred to as “deep layer shear”) accounts for the compensation between instability and shear magnitude. Using a database of about 60,000 soundings, the majority of significant severe events (2+ inch hail, 65+ knot winds, F2+ tornadoes) occur when the product exceeds 20,000 m3/s3.

A little fact on SRH values and tornadoes from NOAA / NWS
Storm Relative Helicity (m² s^-2)
SRH (Storm Relative Helicity) is a measure of the potential for cyclonic updraft rotation in right-moving supercells, and is calculated for the lowest 1-km and 3-km layers above ground level. There is no clear threshold value for SRH when forecasting supercells, since the formation of supercells appears to be related more strongly to the deeper layer vertical shear. Larger values of 0-3-km SRH (greater than 250 m² s^-2) and 0-1-km SRH (greater than 100 m² s^-2), however, do suggest an increased threat of tornadoes with supercells. For SRH, larger values are generally better, but there are no clear thresholds between non-tornadic and significant tornadic supercells.

STP ( Significant Tornado Parameter) EXPLAINED:
A majority of significant tornadoes (EF2 or greater damage) have been associated with STP values greater than 1, while most non-tornadic supercells have been associated with values less than 1 in a large sample of RAP analysis proximity soundings.

SCP (Supercell Composite Parameter) EXPLAINED:
A multiple ingredient, composite index that includes effective storm-relative helicity (ESRH, based on Bunkers right supercell motion), most unstable parcel CAPE (muCAPE) and convective inhibition (muCIN), and effective bulk wind difference (EBWD). Each ingredient is normalized to supercell “threshold” values, and larger values of SCP denote greater “overlap” in the three supercell ingredients. Only positive values of SCP are displayed, which correspond to environments favoring right-moving (cyclonic) supercells.

The following are the SCP (Supercell Composite Parameter) and STP (Significant Tornado Parameter) forecast maps from the NAM 3KM model.  Generally, the higher the values and brighter the color, indicates a greater probability of strong thunderstorm and / or tornadic activity over an area:
NAM 3KM SCP FORECAST 1:00 P.M. EDT MAR. 16 – 9:00 P.M. EDT MAR. 16

NAM 3KM STP FORECAST 1:00 P.M. EDT MAR. 16 – 9:00 P.M. CDT MAR. 16

NAM 3KM RADAR SIMULATION 1:00 P.M. EDT MAR. 16 – 9:00 P.M. EDT MAR. 16

Please use the following maps, which should update automatically, for Mesoscale Discussions and Convective Watches.  You may have to refresh your browser, or click on the graphics.  I have provided the SPC homepage link below, so you may get the updated information regarding any changes to the outlook:
https://www.spc.noaa.gov/classic.html
SPC MESOSCALE DISCUSSIONS (CLICK IMAGE FOR UPDATES)

SPC CONVECTIVE WATCHES (CLICK IMAGE FOR UPDATES)

IF A TORNADO WARNING IS ISSUED FOR YOUR AREA…SEEK STURDY AND SAFE SHELTER IMMEDIATELY!
The following sites will explain most of the severe weather and tornado values listed above, and will give you an idea of what to expect:
ENVIRONMENTAL INDICES AND PARAMETERS NWS
https://www.weather.gov/lmk/indices

THE WEATHER PREDICTION
http://www.theweatherprediction.com/severe/indices/

The following links will connect you to the Excessive Rainfall probabilities and River Flood Outlook:
EXCESSIVE RAINFALL
https://www.wpc.ncep.noaa.gov/qpf/excessive_rainfall_outlook_ero.php

SIGNIFICANT RIVER FLOOD OUTLOOK
https://www.wpc.ncep.noaa.gov/nationalfloodoutlook/index.html

The following NWS Watch / Warning map will provide local NWS information for your area.  Click the image, then once it refreshes, click on your area of interest to view forecasts, any special weather statements, hazards or advisories for your area.
NWS WATCH / WARNING DISPLAY (LINKED…CLICK MAP, THEN YOUR AREA)

NWS DOPPLER RADAR LOOP (LINKED, CLICK RADAR MAP)

RAP RADAR (CLICK IMAGE THEN GO TO LOOP DURATION AND PICK LENGTH OF LOOP, THEN CLICK RADAR SITE)
WUNDERGROUND RADAR SUMMARY MAP (CLICK FOR UPDATES)

PRECIPITATION TYPE (CLICK TO ACCESS ANIMATION FEATURE)

CARIBBEAN RADAR (CLICK IMAGE TO ACCESS ANIMATION)

You may direct any questions by contacting me personally, ANYTIME, at: twalsh22000@yahoo.com

Have a blessed day!

T. F. “STORM” WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST /SEVERE WEATHER SPECIALIST