-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KPBZ 141615
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1215 PM EDT MON APR 14 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL BRING SHOWERS AND STORMS TO THE AREA
LATER TODAY AND OVERNIGHT. MUCH COLDER AIR TUESDAY WITH THE CHANCE
FOR SNOW SHOWERS.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
A STRONG COLD FRONT HAS REACHED WESTERN OHIO EARLY THIS
AFTERNOON. ONE WAVE TRACKING DOWN THE FRONT WITH THE FIRST IN A
SERIES OF WEAK UPPER LEVEL JETLETS AND MID-LEVEL WAVES IS QUICKLY
TRACKING NORTHEASTWARD DOWN THE FRONT. THE BULK OF THE QPF IN
ASSOCIATION WITH THIS WAVE IS LIKELY TO FALL WEST AND NORTH OF THE
AREA...WHILE THE WAVE ITSELF ACTUALLY HAS MANAGED TO SLOW THE
FRONT A BIT THROUGH THE MORNING. HOWEVER...THE SHIELD OF SHOWERS
SHOULD CONTINUE TO SLOWLY TRACK EASTWARD AND ENCOMPASS MUCH OF THE
FORECAST AREA LATER THIS AFTERNOON.

DUE TO ABUNDANT CLOUD COVER AND ONGOING RAIN IN THE AREAS WHERE
MODEL SOLUTIONS SUGGEST INSTABILITY AND SHEAR SHOULD BE MAXIMIZED
THIS AFTERNOON...IT SEEMS LARGE SCALE DESTABILIZATION IS UNLIKELY
UNTIL YOU GET WEST OF OUR AREA AND CLOSER TO THE ACTUAL SURFACE
FRONT. AS SUCH...THUNDERSTORM WORDING WAS ROLLED BACK A CATEGORY
YET AGAIN...PARTICULARLY GIVEN THAT NONE HAS BEEN NOTED INT HE
REGION...EVEN IN THE MORE UNSTABLE/LESS RAIN COOLED AREAS. FRIES
-- End Changed Discussion --

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
FRONT SLOWLY MOVES THROUGH THE AREA LATE TONIGHT/EARLY TUESDAY
MORNING. THE CONVECTIVE THREAT WILL DECREASE TONIGHT AND WINDS
WILL RELAX. MOST OF THE PRECIPITATION WILL MOVE THROUGH DURING
FRONTAL PASSAGE. MUCH COLDER AIR WILL QUICKLY RUSH IN BEHIND THE
FRONT...WHICH SHOULD BE COLD ENOUGH TO CHANGE POST FRONTAL RAIN
SHOWERS TO SNOW SHOWERS. LOOKING WESTWARD...FRONT IS SEPARATING A
WIDE RANGE OF TEMPS WITH READINGS EAST OF THE FRONT IN THE MID
60S TO TEMPERATURES BEHIND THE FRONT IN THE UPPER 30S TO MID 40S.

LOW CONFIDENCE IN THE CURRENT AMOUNT OF QPF MODELS ARE CREATING
BEHIND THE FRONT. AT THIS TIME...IT LOOKS AS IF THERE IS A PERIOD
DIRECTLY BEHIND THE FRONT WHERE THE MODELS ARE OVER DOING THE
AMOUNT OF LIFT. THIS SHORT PERIOD OF STRONG OMEGA IS LIKELY
CAUSING AN OVER AMPLIFICATION OF QPF AMOUNTS TUESDAY MORNING.
TEMPS WILL BE VERY TRICKY ON TUESDAY...LATEST MODEL SOUNDINGS ARE
INITIALLY SHOWING A RAPID DROP OF SURFACE TEMPERATURES WITH
FROPA...AS A SHALLOW LAYER OF LOW LEVEL COLD AIR SETTLES IN. THIS
FEATURE SHOWS UP WELL WITH AN EXAMINATION OF LAYERED THICKNESSES.
LOW LEVEL THICKNESS WILL BECOME COLD ENOUGH FIRST TO SUPPORT
SNOW...HOWEVER THE COLD MID LEVEL THICKNESSES ARE LAGGING BEHIND BY
ABOUT 3 HOURS. THIS SETUP WOULD LIKELY PRODUCE A MIX OF RAIN AND
SNOW WHICH WOULD EVENTUALLY CHANGE TO ALL SNOW. THE OTHER
QUESTION IS HOW FAR DO TEMPS DROP AND WILL THERE BE ANY RECOVERY
DURING THE DAY WITH STRONG CAA ONGOING THROUGHOUT THE DAY.

THE NEXT HEADACHE WILL ARRIVE LATE TUESDAY AFTERNOON THROUGH
TUESDAY EVENING. VERY COLD AIR WILL CROSS THE GREAT LAKES AND
STRONG WINDS ALOFT WILL BE OUT OF THE NORTHWEST. THE MAIN
SHORTWAVE TROUGH SWINGS THROUGH DURING THIS TIME AND MODELS ARE
HINTING AT A PERIOD OF LAKE EFFECT/ENHANCED SNOW SHOWERS.
INVERSIONS TUESDAY EVENING ARE PLENTY DEEP ENOUGH TO SUPPORT LES.

INVERSIONS QUICKLY DROP TUESDAY NIGHT AS WINDS ALOFT VEER TO THE
NORTH AND A STRONG SURFACE HIGH WILL BUILD IN FROM THE WEST. THIS
WILL BRING A QUICK END TO ANY SNOW SHOWERS THAT DEVELOP.

COLD AIR WILL EVACUATE TOWARD THE NORTH WEDNESDAY...THIS WILL
ALLOW FOR A QUICK DECREASE IN CLOUD COVER AND A MODERATION IN
TEMPS.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
A RETURN TO SPRING FOR THE LONG TERM...WITH THE RISK FOR SHOWERS
FRIDAY NIGHT/SAT.

&&

.AVIATION /16Z MONDAY THROUGH FRIDAY/...
PRIMARY AVIATION CONCERN OF THE MRNG WL BE LLVL WIND SHEAR AS LLVL
JET STREAKS ACRS THE REGION.  MIXING AFTER DAYBREAK WL THEN SPPRT
SFC GUSTS OF 25 TO 35KT.

OTHERWISE...VFR CAN BE EXPECTED INTO AFTN...BUT CONDITION
DETERIORATION SHOULD BE ANTICIPATED THEREAFTER AS SHWRS DVLP WITH
THE ADVN OF A CDFNT ACRS THE MIDWEST.  WIDESPREAD RAIN AND
RESTRICTIONS ARE FORECAST AS EVE FALLS.

.OUTLOOK.../TUESDAY THROUGH FRIDAY/...
RESTRICTIONS ARE EXPECTED UNTIL COLD HIGH PRES BLDS LTR ON TUESDAY.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$