Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/24/13
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
356 PM PDT MON APR 22 2013
SYNOPSIS... DRY AND UNSEASONABLY WARM WEATHER CONTINUES THROUGH
THIS WEEK AS HIGH PRESSURE RIDGING DOMINATES THE PATTERN. THERE
WILL BE BREEZY AND LOCALLY WINDY NORTH TO NORTHEAST WINDS
CONTINUING OVERNIGHT INTO TUESDAY. TEMPERATURES WILL GRADUALLY
COOL THROUGH THE THURSDAY AS RIDGING OVER THE AREA WEAKENS BUT
HIGHS WILL REMAIN ABOVE NORMAL.
.SHORT TERM DISCUSSION...
AT 3 PM SURFACE OBSERVATIONS SHOWED SACRAMENTO INTERNATIONAL
AIRPORT WAS 89 DEGREES...88 AT SACRAMENTO EXECUTIVE AIRPORT...88
IN FAIRFIELD AND 87 IN MARYSVILLE AND MODESTO. SACRAMENTO MAY SEE
THE FIRST 90 DEGREE DAY OF THE YEAR. REDDING AND RED BLUFF STARTED
THE DAY VERY MILD AT 64 DEGREES. IF TEMPERATURES DO NOT COOL BELOW
64 BY MIDNIGHT (WHICH IS UNLIKELY) THIS WILL BREAK THE RECORD HIGH
MINIMUM TEMPERATURE FOR THE DATE. THE TEMPERATURES THERE AT 3 PM
WERE ACTUALLY A COUPLE DEGREES COOLER THAN YESTERDAY AT THIS TIME.
AN UPPER LEVEL WAVE IS DIGGING INTO THE GREAT BASIN AND THIS
IS CREATING A RELATIVELY STRONG NORTH-SOUTH SURFACE PRESSURE GRADIENT.
SOME STRONGER WINDS ALOFT ARE MIXING DOWN AS GUSTS THIS
AFTERNOON. WINDS AT 3 PM WERE GUSTING UP TO 30 TO 37 MPH OVER
PORTIONS OF THE NORTHERN AND CENTRAL SACRAMENTO VALLEY. SOME
BLOWING DUST WAS REPORTED BY AN NWS EMPLOYEE ALONG INTERSTATE 5
NEAR CORNING. THE CURRENT GRADIENT IS AROUND 9.1 MB BETWEEN
MEDFORD AND SACRAMENTO WHICH IS A LITTLE WEAKER THAN THE 10 MB
THIS MORNING. THIS SHOULD WEAKEN FURTHER...THEN STRENGTHEN AGAIN
OVERNIGHT BUT WITH LIGHTER GUSTS. THE HRRR MODEL ALSO SHOWS SOME
WEAKENING IN WINDS FOR LATER AFTERNOON AND EVENING. THE STRONGEST
GRADIENT WILL BE OVERNIGHT WHEN MIXING SHOULD BE MORE LIMITED.
BREEZY WINDS ARE EXPECTED FOR TUESDAY. LOCALLY WINDY CONDITIONS
ARE FORECAST ALONG THE WEST SIDE OF THE VALLEY ON TUESDAY. WILL
HOLD OFF FOR NOW ON A WIND ADVISORY DUE TO THE LOCALIZED NATURE
OF THE STRONGER WINDS.
ANOTHER WAVE PASSES EAST OF THE AREA ON WEDNESDAY. THERE WILL BE
SOME FURTHER COOLING FOR THE FORECAST AREA AND IN INCREASE IN
CLOUDS OVER THE MOUNTAINS. HAVE LEFT A SLIGHT CHANCE OF RAIN
SHOWERS OVER THE SIERRA CREST SOUTH OF HIGHWAY 50 BUT EXPECT
LITTLE IN THE WAY OF PRECIPITATION THERE. WINDS WILL BE MORE
FOCUSED OVER SIERRA RIDGES AND CANYONS. THURSDAY SHOULD BE DRY
WITH LIGHT SOUTHWESTERLY WINDS AND SEASONABLY MILD TEMPERATURES. EK
&&
.EXTENDED DISCUSSION (FRIDAY THROUGH MONDAY)
WEAKENING 580DM RIDGE ALIGNED JUST OFFSHORE OF THE PACIFIC
COASTLINE THIS FRIDAY. HIGH PRESSURE RIDGE FLATTENS AND DROPS
SOUTHWARD SATURDAY AHEAD OF AN APPROACHING LOW AMPLITUDE TROUGH.
BOTH THE GFS AND EURO MODELS SHOW THE BASE OF THIS TROUGH ROUNDING
OUT THROUGH CENTRAL OREGON LATER IN THE WEEKEND WHICH WOULD KEEP
MOST OF THE ENERGY OUT OF CALIFORNIA. THE EUROPEAN MODEL SHOWS THE
UPPER LOW EJECTING A VORTICITY IMPULSE LATE SUNDAY TOWARDS OUR
AREA... HOWEVER WITH LIMITED SUPPORT THIS WILL ONLY RESULT IN
INCREASED CLOUDINESS OVER THE SOUTHERN CASCADES AND SIERRA NEVADA
EARLY NEXT WEEK. GFS RUN TO RUN CONSISTENCY RATHER LOW... WITH
FEATURES MOVING OUT OF PHASE. THE EUROPEAN MODEL SHOWS A MORE
CONSISTENT PICTURE FOR THE MIDDLE OF NEXT WEEK WITH WEAK HIGH
PRESSURE SET TO RETURN OVERHEAD. EXPECT DRY CONDITIONS WITH
SLIGHTLY ABOVE AVERAGE TEMPERATURES THROUGHOUT THE EXTENDED PERIOD.
&&
.AVIATION...
VFR CONDITIONS CONTINUE TONIGHT INTO TOMORROW FOR INTERIOR NORCAL
TAF SITES. A TROUGH BRUSHING TO THE NE WILL SETUP A NE-SW SURFACE
PRESSURE GRADIENT WHICH WILL BRING BREEZY WINDS TO THE AREA.
NORTHERLY WINDS OF 10-22 KTS AND GUSTS UP TO 34 KTS WILL CONTINUE
INTO THIS EVENING...WITH THE STRONGEST GUSTS IN THE NORTHERN SAC
VALLEY. INTERMITTENT GUSTY WINDS ARE POSSIBLE OVERNIGHT. SITES
THAT DECOUPLE TO WINDS LESS THAN 8 KNOTS OVERNIGHT WILL HAVE
STRONG WIND SHEAR AS NORTHEAST WINDS 20-30KTS CONTINUE SEVERAL
HUNDRED FEET ABOVE THE SURFACE. WINDS AT ALL SITES WILL RETURN BY
SUNRISE TOMORROW. -DVC
&&
.STO WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
1006 AM EDT MON APR 22 2013
...A FEW STRONG STORMS POSSIBLE LATE THIS AFTERNOON INTO EARLY
THIS EVENING...
.UPDATE...
A MID LEVEL SHORT WAVE MOVED THROUGH SOUTH FLORIDA LAST NIGHT AND
WAS LOCATED OVER THE WESTERN ATLANTIC WATERS THIS MORNING. THIS
SHORT WAVE WILL CONTINUE TO MOVE EAST AWAY FROM SOUTH FLORIDA
THROUGH THE AFTERNOON HOURS TAKING THE SHOWERS AND THUNDERSTORMS
OVER THE LOCAL ATLANTIC WATERS WITH IT...AND ALLOWING FOR THE
SKIES TO BECOME PARTLY CLOUDY BY AFTERNOON. THIS WILL ALSO ALLOW
FOR TEMPERATURES TO WARM UP INTO THE MID 80S ALONG THE METRO AREAS
TO UPPER 80S OVER THE INTERIOR AREAS THIS AFTERNOON.
ANOTHER SHORT WAVE OVER EASTERN GULF OF MEXICO WILL ALSO MOVE EAST
AND THROUGH SOUTH FLORIDA THIS AFTERNOON INTO THIS EVENING...AS A
THROUGH OF LOW PRESSURE OVER SOUTH CENTRAL FLORIDA MOVES SOUTH
INTO THE LAKE OKEECHOBEE AREA. AT THE SAME TIME...BOTH THE EAST
AND WEST COAST SEA BREEZES WILL DEVELOP AND PUSH INLAND WITH THE
WEST COAST SEA BREEZE PUSHING ACROSS THE AREA. SO WILL KEEP THE
POPS LIKELY OVER MOST OF SOUTH FLORIDA FOR THIS AFTERNOON...EXCEPT
CHANCE OVER THE WEST COAST AREAS.
A FEW OF THE STORMS COULD EVEN BECOME STRONG OVER THE INTERIOR AND EAST
COAST METRO AREAS LATE THIS AFTERNOON INTO EARLY THIS EVENING
ESPECIALLY WHERE THE SEA BREEZES COLLIDE. THE PRIMARY IMPACTS WILL
BE FREQUENT LIGHTNING STRIKES...GUSTY WINDS...SMALL HAIL...AND
HEAVY RAINFALL.
A NORTHEAST SWELL OF 2 TO 4 FEET WILL ALSO CONTINUE TO WORK INTO
THE NORTHERN WATERS OF PALM BEACH COUNTY THIS AFTERNOON.
HOWEVER...THE WIND FLOW WILL BE FROM THE EAST TO SOUTH DIRECTION
AT 5 TO 10 KNOTS. THIS WILL ONLY ALLOW FOR THE SEAS TO BUILD UP TO
6 FEET THIS AFTERNOON INTO THIS EVENING. THEREFORE...THE SCA WILL
BE DROP AND A SCEC WILL BE PUT UP FOR THE WEST PALM BEACH WATERS
FOR THIS AFTERNOON INTO THIS EVENING.
REST OF THE FORECAST LOOKS GOOD AT THIS TIME AND NO OTHER CHANGES
ARE PLANNED.
&&
.UPDATE...54/BNB
.PREV DISCUSSION... /ISSUED 741 AM EDT MON APR 22 2013/
AVIATION...
A LOW PRESSURE TROUGH WILL CROSS THE REGION TODAY...BRINGING
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. WIDESPREAD ACTIVITY
THIS MORNING IMPACTING ATLANTIC WATERS WILL MOSTLY STAY
OFFSHORE...AND LATEST GUIDANCE HINTS AT FAIRLY LOW COVERAGE OF
PRECIPITATION THROUGH THE MORNING HOURS. THUS...NO PREVAILING
SHRA/TSRA IN 12Z TAFS. INSTEAD...VCSH THROUGH 18Z...THEN VCTS. LOW
STRATUS IMPACTING BROWARD AND MIAMI-DADE TERMINALS...BUT THIS SHOULD
BREAK AWAY BY 13-14Z...THEN VFR PREVAILS. TEMPORARY BUT SIGNIFICANT
RESTRICTIONS ARE POSSIBLE THROUGHOUT THE DAY...IN AND NEAR PCPN.
HIGH PRESSURE BUILDS IN TONIGHT...WITH CLEARING SKIES EXPECTED.
GENERAL EASTERLY FLOW AT AROUND 10 KTS TODAY...BECOMING NORTH
TONIGHT. GUSTY WINDS ARE POSSIBLE NEAR THUNDERSTORMS.
&&
PREV DISCUSSION... /ISSUED 328 AM EDT MON APR 22 2013/
SHORT TERM (TODAY THROUGH WEDNESDAY)...
THE GLOBAL MODELS ARE IN GENERAL AGREEMENT WITH THE OVERALL SYNOPTIC
SHORT TERM PATTERN IN DEPICTING A NEAR ZONAL FLOW ACROSS MUCH OF
SOUTHEASTERN STATES ALONG WITH A STATIONARY SURFACE FRONTAL TROUGH
ACROSS SOUTH CENTRAL FLORIDA. A FAST MOVING SOUTHERN STREAM MID
LEVEL TROUGH EMBEDDED WITHIN THIS FLOW IS CURRENTLY MOVING INTO THE
EASTERN GULF OF MEXICO AND WILL MOVE ACROSS THE PENINSULA THIS
MORNING. THIS FEATURE IS ALREADY GENERATING CONVECTION OVER THE
FLORIDA KEYS. THE SHORT TERM HIGH RESOLUTION MODELS HOWEVER DO NOT
HAVE A GOOD HANDLE ON WHAT EFFECTS THIS WILL HAVE FOR SOUTH FLORIDA
ESPECIALLY PARTICULARLY FOR TODAY. THE LOCALLY RUN WRF DID NOT
INITIALIZE WELL AT ALL AND IGNORES MUCH OF THE ONGOING CONVECTION.
THE HRRR DEPICTS THE AREA SHIFTING EAST DURING THE COURSE OF THIS
MORNING AND THIS SEEMS THE MOST REASONABLE GIVEN THE LATEST RADAR
AND SATELLITE ANIMATIONS. THE REAL DILEMMA IN TODAY`S FORECAST IS
JUST HOW MUCH DESTABILIZATION WILL OCCUR CONSIDERING THE EXTENSIVE
MID AND HIGH CLOUD COVER. GIVEN THE UNCERTAINTIES BUT THE FACT THAT
WE ARE BEING INFLUENCED BY A BROAD CYCLONIC FLOW ALOFT WITH 500 MB
TEMPERATURES OF AROUND -11C WILL SUPPORT MODEST INSTABILITY. IN
ADDITION, THE PWAT FROM THE 00Z MFL SOUNDING IS AT 1.87 INCHES WHICH
IS NEAR THE MAXIMUM FOR LATE APRIL WHICH SHOWS THE CHANCE FOR
LOCALLY HEAVY RAINFALL TO OCCUR. THEREFORE, ANY SUNSHINE THAT CAN
OCCUR TODAY WILL PROVIDE SUFFICIENT LIFT WITH SOME CHANCE FOR STRONG
WIND GUSTS AND SMALL HAIL ALONG WITH THE THREAT FOR LIGHTNING.
THE MID LEVEL AND SURFACE TROUGHS WILL SHIFT SOUTH AND EAST OF THE
PENINSULA BY THIS EVENING AS THEY GET KICKED OUT BY A DEEPENING
TROUGH INTO THE CENTRAL PLAINS STATES. THIS WILL ALSO BUILD A RIDGE
ACROSS THE AREA WITH A MUCH DRIER AND MORE STABLE ATMOSPHERE. SO A
MUCH QUIETER WEATHER PATTERN IS EXPECTED BY TUESDAY AND WEDNESDAY.
THAT BEING SAID, THE MENTION OF THUNDER ON TUESDAY HAS BEEN TAKEN
OUT OF THE GRIDS WITH FORECAST SOUNDINGS INDICATING PWAT DROPPING
TO LESS THAN AN INCH AND A QUARTER WITH VERY DRY ABOVE 5-10 K FEET.
LONG TERM (WEDNESDAY NIGHT THROUGH SUNDAY)...
LOOKING AHEAD TO THE END OF THE WEEK AND THE UPCOMING WEEKEND, MUCH
OF THE PERIOD WILL BE IN A BENIGN WEATHER PATTERN WITH MID LEVEL
RIDGING AND SURFACE HIGH PRESSURE STRETCHING ACROSS SOUTH FLORIDA.
ANOTHER WEAKENING COLD FRONT WILL MOVE INTO NORTH FLORIDA BY LATE
THURSDAY OR FRIDAY AND THEN RAPIDLY BECOMES DIFFUSE. SO LITTLE
CHANCE FOR RAINFALL AFTER TODAY THROUGH THE FORECAST PERIOD.
MARINE...
A NORTHEAST SWELL WILL BEGIN TO AFFECT THE ATLANTIC WATERS OFF OF
THE PALM BEACH COUNTY COAST THIS AFTERNOON AND CONTINUE THROUGH
LATE TONIGHT. THIS WILL RESULT IN ROUGH WATERS AND A SCA HAS BEEN
ISSUED FOR THIS REASON. OTHER THAN THAT, AN UPPER LEVEL
DISTURBANCE ALONG WITH A SURFACE TROUGH WILL MOVE ACROSS THE SOUTH
FLORIDA WATERS TODAY WITH NUMEROUS SHOWERS AND THUNDERSTORMS. SOME
OF THE STRONGER STORMS MAY PRODUCE STRONG WIND GUSTS. HIGH
PRESSURE WILL RETURN TO THE REGION TONIGHT AND CONTINUE THROUGH
THE END OF THE WEEK.
FIRE WEATHER...
THE RELATIVE HUMIDITY WILL REMAIN WELL ABOVE CRITICAL LEVELS
THROUGH MID WEEK AS HIGH PRESSURE BUILDS BACK ACROSS SOUTH FLORIDA
TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 67 83 69 / 70 30 10 -
FORT LAUDERDALE 83 72 84 74 / 60 40 10 -
MIAMI 85 71 86 73 / 70 40 10 -
NAPLES 85 67 88 67 / 50 20 10 -
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 2 PM THIS AFTERNOON
TO 5 AM EDT TUESDAY FOR COASTAL WATERS FROM JUPITER INLET
TO DEERFIELD BEACH, FL OUT 20 NM-WATERS FROM JUPITER INLET
TO DEERFIELD BEACH, FL EXTENDING FROM 20 NM TO 60 NM.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...54/BNB
AVIATION/RADAR...13/SI
AREA FORECAST DISCUSSION
NWS MIAMI FL
741 AM EDT MON APR 22 2013
.AVIATION...
A LOW PRESSURE TROUGH WILL CROSS THE REGION TODAY...BRINGING
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. WIDESPREAD ACTIVITY
THIS MORNING IMPACTING ATLANTIC WATERS WILL MOSTLY STAY
OFFSHORE...AND LATEST GUIDANCE HINTS AT FAIRLY LOW COVERAGE OF
PRECIPITATION THROUGH THE MORNING HOURS. THUS...NO PREVAILING
SHRA/TSRA IN 12Z TAFS. INSTEAD...VCSH THROUGH 18Z...THEN VCTS. LOW
STRATUS IMPACTING BROWARD AND MIAMI-DADE TERMINALS...BUT THIS SHOULD
BREAK AWAY BY 13-14Z...THEN VFR PREVAILS. TEMPORARY BUT SIGNIFICANT
RESTRICTIONS ARE POSSIBLE THROUGHOUT THE DAY...IN AND NEAR PCPN.
HIGH PRESSURE BUILDS IN TONIGHT...WITH CLEARING SKIES EXPECTED.
GENERAL EASTERLY FLOW AT AROUND 10 KTS TODAY...BECOMING NORTH
TONIGHT. GUSTY WINDS ARE POSSIBLE NEAR THUNDERSTORMS.
&&
.PREV DISCUSSION... /ISSUED 328 AM EDT MON APR 22 2013/
SHORT TERM (TODAY THROUGH WEDNESDAY)...
THE GLOBAL MODELS ARE IN GENERAL AGREEMENT WITH THE OVERALL SYNOPTIC
SHORT TERM PATTERN IN DEPICTING A NEAR ZONAL FLOW ACROSS MUCH OF
SOUTHEASTERN STATES ALONG WITH A STATIONARY SURFACE FRONTAL TROUGH
ACROSS SOUTH CENTRAL FLORIDA. A FAST MOVING SOUTHERN STREAM MID
LEVEL TROUGH EMBEDDED WITHIN THIS FLOW IS CURRENTLY MOVING INTO THE
EASTERN GULF OF MEXICO AND WILL MOVE ACROSS THE PENINSULA THIS
MORNING. THIS FEATURE IS ALREADY GENERATING CONVECTION OVER THE
FLORIDA KEYS. THE SHORT TERM HIGH RESOLUTION MODELS HOWEVER DO NOT
HAVE A GOOD HANDLE ON WHAT EFFECTS THIS WILL HAVE FOR SOUTH FLORIDA
ESPECIALLY PARTICULARLY FOR TODAY. THE LOCALLY RUN WRF DID NOT
INITIALIZE WELL AT ALL AND IGNORES MUCH OF THE ONGOING CONVECTION.
THE HRRR DEPICTS THE AREA SHIFTING EAST DURING THE COURSE OF THIS
MORNING AND THIS SEEMS THE MOST REASONABLE GIVEN THE LATEST RADAR
AND SATELLITE ANIMATIONS. THE REAL DILEMMA IN TODAY`S FORECAST IS
JUST HOW MUCH DESTABILIZATION WILL OCCUR CONSIDERING THE EXTENSIVE
MID AND HIGH CLOUD COVER. GIVEN THE UNCERTAINTIES BUT THE FACT THAT
WE ARE BEING INFLUENCED BY A BROAD CYCLONIC FLOW ALOFT WITH 500 MB
TEMPERATURES OF AROUND -11C WILL SUPPORT MODEST INSTABILITY. IN
ADDITION, THE PWAT FROM THE 00Z MFL SOUNDING IS AT 1.87 INCHES WHICH
IS NEAR THE MAXIMUM FOR LATE APRIL WHICH SHOWS THE CHANCE FOR
LOCALLY HEAVY RAINFALL TO OCCUR. THEREFORE, ANY SUNSHINE THAT CAN
OCCUR TODAY WILL PROVIDE SUFFICIENT LIFT WITH SOME CHANCE FOR STRONG
WIND GUSTS AND SMALL HAIL ALONG WITH THE THREAT FOR LIGHTNING.
THE MID LEVEL AND SURFACE TROUGHS WILL SHIFT SOUTH AND EAST OF THE
PENINSULA BY THIS EVENING AS THEY GET KICKED OUT BY A DEEPENING
TROUGH INTO THE CENTRAL PLAINS STATES. THIS WILL ALSO BUILD A RIDGE
ACROSS THE AREA WITH A MUCH DRIER AND MORE STABLE ATMOSPHERE. SO A
MUCH QUIETER WEATHER PATTERN IS EXPECTED BY TUESDAY AND WEDNESDAY.
THAT BEING SAID, THE MENTION OF THUNDER ON TUESDAY HAS BEEN TAKEN
OUT OF THE GRIDS WITH FORECAST SOUNDINGS INDICATING PWAT DROPPING
TO LESS THAN AN INCH AND A QUARTER WITH VERY DRY ABOVE 5-10 K FEET.
LONG TERM (WEDNESDAY NIGHT THROUGH SUNDAY)...
LOOKING AHEAD TO THE END OF THE WEEK AND THE UPCOMING WEEKEND, MUCH
OF THE PERIOD WILL BE IN A BENIGN WEATHER PATTERN WITH MID LEVEL
RIDGING AND SURFACE HIGH PRESSURE STRETCHING ACROSS SOUTH FLORIDA.
ANOTHER WEAKENING COLD FRONT WILL MOVE INTO NORTH FLORIDA BY LATE
THURSDAY OR FRIDAY AND THEN RAPIDLY BECOMES DIFFUSE. SO LITTLE
CHANCE FOR RAINFALL AFTER TODAY THROUGH THE FORECAST PERIOD.
MARINE...
A NORTHEAST SWELL WILL BEGIN TO AFFECT THE ATLANTIC WATERS OFF OF
THE PALM BEACH COUNTY COAST THIS AFTERNOON AND CONTINUE THROUGH
LATE TONIGHT. THIS WILL RESULT IN ROUGH WATERS AND A SCA HAS BEEN
ISSUED FOR THIS REASON. OTHER THAN THAT, AN UPPER LEVEL
DISTURBANCE ALONG WITH A SURFACE TROUGH WILL MOVE ACROSS THE SOUTH
FLORIDA WATERS TODAY WITH NUMEROUS SHOWERS AND THUNDERSTORMS. SOME
OF THE STRONGER STORMS MAY PRODUCE STRONG WIND GUSTS. HIGH
PRESSURE WILL RETURN TO THE REGION TONIGHT AND CONTINUE THROUGH
THE END OF THE WEEK.
FIRE WEATHER...
THE RELATIVE HUMIDITY WILL REMAIN WELL ABOVE CRITICAL LEVELS
THROUGH MID WEEK AS HIGH PRESSURE BUILDS BACK ACROSS SOUTH FLORIDA
TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 81 67 83 69 / 80 30 10 -
FORT LAUDERDALE 81 72 84 74 / 70 30 10 -
MIAMI 83 71 86 73 / 70 30 10 -
NAPLES 82 67 88 67 / 70 20 10 -
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 2 PM THIS AFTERNOON
TO 5 AM EDT TUESDAY FOR COASTAL WATERS FROM JUPITER INLET
TO DEERFIELD BEACH, FL OUT 20 NM-WATERS FROM JUPITER INLET
TO DEERFIELD BEACH, FL EXTENDING FROM 20 NM TO 60 NM.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...30/KOB
AVIATION/RADAR...23/SK
AREA FORECAST DISCUSSION
NWS MIAMI FL
328 AM EDT MON APR 22 2013
.SHORT TERM (TODAY THROUGH WEDNESDAY)...
THE GLOBAL MODELS ARE IN GENERAL AGREEMENT WITH THE OVERALL SYNOPTIC
SHORT TERM PATTERN IN DEPICTING A NEAR ZONAL FLOW ACROSS MUCH OF
SOUTHEASTERN STATES ALONG WITH A STATIONARY SURFACE FRONTAL TROUGH
ACROSS SOUTH CENTRAL FLORIDA. A FAST MOVING SOUTHERN STREAM MID
LEVEL TROUGH EMBEDDED WITHIN THIS FLOW IS CURRENTLY MOVING INTO THE
EASTERN GULF OF MEXICO AND WILL MOVE ACROSS THE PENINSULA THIS
MORNING. THIS FEATURE IS ALREADY GENERATING CONVECTION OVER THE
FLORIDA KEYS. THE SHORT TERM HIGH RESOLUTION MODELS HOWEVER DO NOT
HAVE A GOOD HANDLE ON WHAT EFFECTS THIS WILL HAVE FOR SOUTH FLORIDA
ESPECIALLY PARTICULARLY FOR TODAY. THE LOCALLY RUN WRF DID NOT
INITIALIZE WELL AT ALL AND IGNORES MUCH OF THE ONGOING CONVECTION.
THE HRRR DEPICTS THE AREA SHIFTING EAST DURING THE COURSE OF THIS
MORNING AND THIS SEEMS THE MOST REASONABLE GIVEN THE LATEST RADAR
AND SATELLITE ANIMATIONS. THE REAL DILEMMA IN TODAY`S FORECAST IS
JUST HOW MUCH DESTABILIZATION WILL OCCUR CONSIDERING THE EXTENSIVE
MID AND HIGH CLOUD COVER. GIVEN THE UNCERTAINTIES BUT THE FACT THAT
WE ARE BEING INFLUENCED BY A BROAD CYCLONIC FLOW ALOFT WITH 500 MB
TEMPERATURES OF AROUND -11C WILL SUPPORT MODEST INSTABILITY. IN
ADDITION, THE PWAT FROM THE 00Z MFL SOUNDING IS AT 1.87 INCHES WHICH
IS NEAR THE MAXIMUM FOR LATE APRIL WHICH SHOWS THE CHANCE FOR
LOCALLY HEAVY RAINFALL TO OCCUR. THEREFORE, ANY SUNSHINE THAT CAN
OCCUR TODAY WILL PROVIDE SUFFICIENT LIFT WITH SOME CHANCE FOR STRONG
WIND GUSTS AND SMALL HAIL ALONG WITH THE THREAT FOR LIGHTNING.
THE MID LEVEL AND SURFACE TROUGHS WILL SHIFT SOUTH AND EAST OF THE
PENINSULA BY THIS EVENING AS THEY GET KICKED OUT BY A DEEPENING
TROUGH INTO THE CENTRAL PLAINS STATES. THIS WILL ALSO BUILD A RIDGE
ACROSS THE AREA WITH A MUCH DRIER AND MORE STABLE ATMOSPHERE. SO A
MUCH QUIETER WEATHER PATTERN IS EXPECTED BY TUESDAY AND WEDNESDAY.
THAT BEING SAID, THE MENTION OF THUNDER ON TUESDAY HAS BEEN TAKEN
OUT OF THE GRIDS WITH FORECAST SOUNDINGS INDICATING PWAT DROPPING
TO LESS THAN AN INCH AND A QUARTER WITH VERY DRY ABOVE 5-10 K FEET.
.LONG TERM (WEDNESDAY NIGHT THROUGH SUNDAY)...
LOOKING AHEAD TO THE END OF THE WEEK AND THE UPCOMING WEEKEND, MUCH
OF THE PERIOD WILL BE IN A BENIGN WEATHER PATTERN WITH MID LEVEL
RIDGING AND SURFACE HIGH PRESSURE STRETCHING ACROSS SOUTH FLORIDA.
ANOTHER WEAKENING COLD FRONT WILL MOVE INTO NORTH FLORIDA BY LATE
THURSDAY OR FRIDAY AND THEN RAPIDLY BECOMES DIFFUSE. SO LITTLE
CHANCE FOR RAINFALL AFTER TODAY THROUGH THE FORECAST PERIOD.
&&
.MARINE...
A NORTHEAST SWELL WILL BEGIN TO AFFECT THE ATLANTIC WATERS OFF OF
THE PALM BEACH COUNTY COAST THIS AFTERNOON AND CONTINUE THROUGH
LATE TONIGHT. THIS WILL RESULT IN ROUGH WATERS AND A SCA HAS BEEN
ISSUED FOR THIS REASON. OTHER THAN THAT, AN UPPER LEVEL
DISTURBANCE ALONG WITH A SURFACE TROUGH WILL MOVE ACROSS THE SOUTH
FLORIDA WATERS TODAY WITH NUMEROUS SHOWERS AND THUNDERSTORMS. SOME
OF THE STRONGER STORMS MAY PRODUCE STRONG WIND GUSTS. HIGH
PRESSURE WILL RETURN TO THE REGION TONIGHT AND CONTINUE THROUGH
THE END OF THE WEEK.
&&
.FIRE WEATHER...
THE RELATIVE HUMIDITY WILL REMAIN WELL ABOVE CRITICAL LEVELS
THROUGH MID WEEK AS HIGH PRESSURE BUILDS BACK ACROSS SOUTH FLORIDA
TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 81 67 83 69 / 80 30 10 -
FORT LAUDERDALE 81 72 84 74 / 70 30 10 -
MIAMI 83 71 86 73 / 70 30 10 -
NAPLES 82 67 88 67 / 70 20 10 -
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 2 PM THIS AFTERNOON
TO 5 AM EDT TUESDAY FOR COASTAL WATERS FROM JUPITER INLET
TO DEERFIELD BEACH, FL OUT 20 NM-WATERS FROM JUPITER INLET
TO DEERFIELD BEACH, FL EXTENDING FROM 20 NM TO 60 NM.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...30/KOB
AVIATION/RADAR...23/SK
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
315 AM EDT MON APR 22 2013
...ONE MORE UNSETTLED DAY BEFORE DRIER CONDITIONS ARRIVE FOR
MIDWEEK...
.SYNOPSIS
07Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS BROAD MID/UPPER LEVEL
TROUGHING IN PLACE OVER THE SOUTHEASTERN CONUS. WEAK SHORTWAVE
IMPULSE IS CURRENTLY PASSING TO OUR NORTH EARLY THIS MORNING WITHIN
THE MAIN FLOW...WITH ANOTHER WEAK IMPULSE NOT FAR BEHIND AND PROGGED
TO PASS THROUGH LATER TODAY. PLENTY OF MID/UPPER LEVEL MOISTURE SEEN
IN WV IMAGERY OVER THE PENINSULA...WITH A SHARP GRADIENT IN THE
MOISTURE BEGINNING TO ERODE SOUTHWARD FROM THE BIG BEND. DEEP LAYER
QG FORCING ASSOCIATED WITH THE PASSING SHORTWAVE ALONG WITH A
COUPLED UPPER JET PATTERN OVERHEAD HAVE PROVIDED AMPLE LIFT TO
SUPPORT WIDESPREAD SHOWERS/ISOLATED STORMS EARLY THIS MORNING FROM
THE I-4 CORRIDOR SOUTHWARD. SHOWERS HAVE BEEN MORE SPARSE FURTHER
NORTH THROUGH THE NATURE COAST AS THE DRIER AIR IS TRYING TO ARRIVE.
AT THE SURFACE...FORECAST AREA RESIDES BETWEEN AN OLD
QUASI-STATIONARY FRONTAL BOUNDARY OVER THE SOUTHERN FL
PENINSULA...AND STRONG HIGH PRESSURE RIDGING DOWN THE ATLANTIC
SEABOARD INTO GA/AL. LARGE AREA OF WIDESPREAD RAIN FROM TAMPA
SOUTHWARD CONTINUES TO WEAKEN ON REGIONAL RADARS...HOWEVER EVEN IN
ITS WAKE...RESIDUAL LIFT AND MOISTURE WILL KEEP THE CHANCE OF
ADDITIONAL SHOWER DEVELOPMENT IN THE FORECAST AT JUST ABOUT ANY
TIME.
&&
.SHORT TERM (TODAY THROUGH WEDNESDAY)...
TODAY...
EXPECTING A GENERALLY UNSETTLED DAY IN TERMS OF SHOWERS AND ISOLATED
STORMS FOR AT LEAST THE SOUTHERN 2/3RDS OF THE FORECAST AREA. THE
FURTHER NORTH ONE TRAVELS FROM THE I-4 CORRIDOR...DEEP LAYER
MOISTURE WILL BE DECREASING QUICKLY...AND SHOULD LIMIT THE DEGREE OF
OVERALL SHOWER ACTIVITY. WILL SHOW CHANCE 30-50% POPS FOR MAINLY
MORNING/EARLY AFTERNOON SHOWERS UP TOWARD CITRUS/LEVY COUNTIES.
ALONG THE I-4 CORRIDOR AND ESPECIALLY SOUTHWARD...NUMEROUS SHOWERS
AND ISOLATED STORMS WILL REMAIN IN THE FORECAST. THIS CONVECTIVE
ACTIVITY WILL LIKELY PEAK IN THE AFTERNOON/EARLY EVENING DUE TO THE
APPROACH OF THE NEXT SHORTWAVE AND ASSOCIATED SYNOPTIC SUPPORT/QG
FORCING ALONG WITH RETAINING A COUPLET JET DIVERGENT PATTERN...AND
THE DIURNAL HEATING MAXIMUM. WILL SHOW 60-70% POPS FOR THESE
CENTRAL/SOUTHERN ZONES...WITH BETTER RAIN CHANCES LIKELY SHIFTING
SOMEWHAT EAST AND SOUTH BY LATE DAY FOLLOWING THE RETREAT OF THE
DEEP LAYER MOISTURE. EXPECTING A MOSTLY CLOUDY DAY...HOWEVER
THE COLUMN POTENTIAL IS QUITE HIGH IN TERMS OF TEMPERATURES...AND
THEREFORE EVEN A FEW SUNNY BREAKS WILL HELP TEMPS REACH THE LOWER
80S. WILL SHOW THESE NUMBERS FOR HIGH TEMPERATURES...HOWEVER ANY
AREAS WITH EARLY OR ROBUST CONVECTIVE COVERAGE TODAY MAY VERY LIKELY
BE HELD IN THE 70S.
TONIGHT...
ANY EVENING SHOWERS SOUTH AND EAST OF THE TAMPA BAY AREA SHOULD END
RATHER QUICKLY AFTER SUNSET AS SHORTWAVE SUPPORT EXITS AND TAKES
THE SURFACE BOUNDARY EAST INTO THE ATLANTIC. AT THE SAME
TIME...SUBSIDENCE BEHIND THIS IMPULSE WILL HELP TO FURTHER ADVECT A
DRY MID/UPPER LEVEL COLUMN OVER OUR HEADS. AT THE SURFACE... THE
RIDGING THAT EXTENDS DOWN THE LEE OF THE APPALACHIANS WILL BUILD
SOUTHWARD INTO THE NORTHERN/CENTRAL FL PENINSULA. ALTHOUGH THE DEEP
LAYER MOISTURE WILL BE GONE...TIME-HEIGHT AND CROSS SECTION ANALYSIS
SHOWS THAT THERE WILL BE PLENTY OF LOW LEVEL MOISTURE TRAPPED UNDER
700MB. THE VERY DRY COLUMN OVERTOP THIS MOISTURE AND THE NE FLOW
SUGGEST THE DEVELOPMENT OF AREAS OF LOW LEVEL STRATUS OVERNIGHT.
THESE CLOUDS WILL HAVE LITTLE IMPACT ON OUR SENSIBLE WEATHER...BUT
WOULD HAVE IMPACTS FOR AVIATION.
TUESDAY/WEDNESDAY...
SHORTWAVE ENERGY EJECTING EASTWARD ACROSS THE CENTRAL PORTION OF THE
NATION WILL FORCE DOWNSTREAM MID/UPPER LEVEL RIDGE AMPLIFICATION
OVER THE EASTERN GULF AND FL PENINSULA THROUGH THE PERIOD. THIS
RIDGING WILL EXIST OVERTOP SURFACE HIGH PRESSURE THAT WILL FIRMLY BE
IN CONTROL OF THE REGION. THE STACKED RIDGING AND GENERALLY DRY
COLUMN ABOVE 850MB WILL RESULT IN A RAIN-FREE FORECAST INTO THE
MIDDLE OF THE WEEK...ALONG WITH SEASONABLE DAYTIME TEMPERATURES...
AND SEASONABLY COOL OVERNIGHT TEMPS. HIGH TEMPS TUESDAY AND
WEDNESDAY SHOULD REACH INTO THE 80S. LOW TEMPS TUESDAY NIGHT FROM
THE LOW/MID 60S SOUTH...TO THE MID/UPPER 50S NORTH.
&&
.LONG TERM (THURSDAY THROUGH NEXT SUNDAY)...
UPPER LEVEL RIDGING GENERALLY DOMINATES THE GULF OF MEXICO AND FL
THROUGH THE END OF THE WORK WEEK AS AN UPPER LEVEL TROUGH MOVES
ACROSS THE EASTERN STATES. THIS TROUGH PUSHES A FRONTAL BOUNDARY
INTO THE SE U.S THURSDAY THEN NORTHERN FL FRI WHERE IT WASHES OUT. A
SURFACE HIGH MOVES FROM THE EASTERN PLAINS TO THE OHIO
VALLEY...BRIDGING THE BOUNDARY BY FRI.
OVER THE WEEKEND THE UPPER RIDGE SLIDES ACROSS FL AS A UPPER TROUGH
MOVES INTO THE SOUTHERN PLAINS AND WESTERN GULF WITH ANOTHER FRONTAL
BOUNDARY SAGGING IN ALONG THE WEST/CENTRAL GULF COAST. THE OHIO
VALLEY SURFACE HIGH MOVES ACROSS THE EASTERN SEABOARD TO THE
ATLANTIC WITH LOW LEVEL FLOW ACROSS THE AREA VEERING FROM NORTHEAST
TO EAST AND SOUTHEAST.
THE UPPER LEVEL RIDGING AND THE BOUNDARY WASHING OUT TO THE NORTH
WILL KEEP ANY RAIN CHANCES OUT OF THE FORECAST THROUGH SAT. BY SUN
THE UPPER RIDGE EAST OF THE STATE AND INCREASING MOISTURE ON EAST
AND SE LOW LEVEL FLOW...WITH A GRADIENT RELAXED ENOUGH FOR AN
AFTERNOON SEA BREEZE...COMBINE TO PROVIDE A SLIGHT CHANCE OF
THUNDERSTORMS. TEMPERATURES WILL RUN NEAR TO SLIGHTLY ABOVE
NORMAL.
&&
.MARINE...
A STRONG RIDGE OF HIGH PRESSURE BUILDS SOUTH INTO THE EASTERN GULF
OF MEXICO LATER TODAY AND TONIGHT. EASTERLY WINDS WILL INCREASE BY
THIS EVENING IN ASSOCIATED WITH THIS FEATURE AND LIKELY RESULT IN A
PERIOD OF CAUTIONARY WINDS INTO TUESDAY MORNING...ESPECIALLY FOR
MARINE AREAS ADJACENT TO TAMPA BAY AND NORTHWARD. THE HIGH CENTER TO
THE NORTH OF THE AREA TUESDAY NIGHT WILL AGAIN SET UP FAVORABLE
CONDITIONS FOR A NOCTURNAL EASTERLY WIND SURGE TO CAUTIONARY
LEVELS...WHICH SHOULD LINGER INTO EARLY WEDNESDAY MORNING. A
WEAKENING GRADIENT IS THEN EXPECTED TO KEEP WINDS AND SEAS BELOW
HEADLINE CRITERIA FOR THE LATER PORTION OF THE WEEK.
&&
.AVIATION...
LARGE AREA OF CLOUDINESS WITH SHRA/RA WILL KEEP TAF/S MVFR TO LCL
IFR. ANTICIPATE VFR RETURN AFTER SUNRISE WITH SOME TSRA IN THE
AFTERNOON.
&&
.FIRE WEATHER...
ABUNDANT LOW LEVEL MOISTURE AND SCATTERED TO NUMEROUS SHOWERS WILL
KEEP RELATIVE HUMIDITY VALUES WELL ABOVE CRITICAL LEVELS TODAY. A
DRIER AIRMASS WILL ARRIVE FOR TUESDAY AND WEDNESDAY WHEN A FEW
INLAND LOCATIONS MAY BRIEFLY SEE RELATIVE HUMIDITY VALUES DROP INTO
THE MIDDLE 30S DURING THE AFTERNOON HOURS. NO RED FLAG CONDITIONS
ARE CURRENTLY EXPECTED THROUGH THE MIDDLE OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 83 67 85 65 / 60 10 10 10
FMY 85 66 88 64 / 60 20 10 10
GIF 85 63 87 61 / 70 10 10 10
SRQ 82 66 85 63 / 60 10 10 10
BKV 82 62 85 57 / 60 10 10 10
SPG 82 69 84 68 / 60 10 10 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM/AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS LINCOLN IL
259 PM CDT MON APR 22 2013
.DISCUSSION...
ISSUED 259 PM CDT MON APR 22 2013
MAIN WEATHER STORY CONTINUES TO BE THE RAIN EVENT COMING INTO THE
PICTURE LATE TONIGHT THROUGH TUESDAY NIGHT.
19Z/2PM SURFACE MAP SHOWS HIGH PRESSURE EXTENDING FROM NEW ENGLAND
TO THE WESTERN GULF OF MEXICO. FURTHER NORTHWEST...LOW PRESSURE IS
CENTERED NEAR HUDSON BAY...WITH STRONG COLD FRONT TRAILING
SOUTHWESTWARD INTO THE CENTRAL PLAINS. ALOFT...LARGE RIDGE IS IN
PLACE OVER THE EASTERN PACIFIC...WHILE A VIGOROUS SHORT-WAVE
DROPPING INTO THE CENTRAL ROCKIES IS BEGINNING TO DIG A TROUGH
DOWNSTREAM ACROSS THE CENTRAL CONUS.
SHORT TERM...TONIGHT THROUGH THURSDAY
LEAD SHORT-WAVE CURRENTLY EVIDENT ON WATER VAPOR IMAGERY OVER
WESTERN NEBRASKA/KANSAS WILL TRACK EASTWARD THIS EVENING. CLUSTER
OF THUNDERSTORMS ASSOCIATED WITH THIS FEATURE WEST OF KANSAS CITY
WILL SHIFT EASTWARD AND WEAKEN WITH TIME AS IT ENCOUNTERS A MUCH
DRIER AIRMASS FURTHER EAST ACROSS ILLINOIS. 3KM HRRR SHOWS REMNANTS
OF THIS CONVECTION TRYING TO WORK ITS WAY INTO WEST-CENTRAL
ILLINOIS BETWEEN 00Z AND 03Z...HOWEVER QPF AMOUNTS ARE PALTRY.
BASED ON INITIALLY VERY DRY FORECAST SOUNDINGS...THINK THIS FIRST
WAVE WILL DO LITTLE MORE THAN TO MOISTEN THE AIRMASS FOR THE MAIN
WAVE ON TUESDAY. HAVE THEREFORE DOWNPLAYED RAIN CHANCES EARLY
TONIGHT...FEATURING ONLY LOW CHANCE POPS FOR SHOWERS WEST OF I-55
THROUGH MIDNIGHT. RAIN CHANCES BEGIN TO INCREASE OVERNIGHT...AS
MAIN WAVE AND ASSOCIATED COLD FRONT APPROACHES FROM THE WEST.
SOUNDINGS SHOW AT LEAST MODEST ELEVATED INSTABILITY...SO WILL
MENTION CHANCE FOR THUNDER AFTER MIDNIGHT.
FRONTAL BOUNDARY SLOWLY PUSHES EASTWARD THROUGH CENTRAL ILLINOIS
ON TUESDAY...WITH SURFACE LOW PRESSURE EXPECTED TO RIDE ALONG THE
BOUNDARY AS IT DOES SO. COMBINATION OF STRONG LOW-LEVEL FORCING
ALONG FRONT...VIGOROUS UPPER DYNAMICS COMING IN FROM THE WEST...AND
INCREASINGLY DEEP MOISTURE WITH PRECIPITABLE WATER VALUES
EXCEEDING 1 INCH...WILL LEAD TO THE DEVELOPMENT OF WIDESPREAD
SHOWERS AND THUNDERSTORMS ACROSS THE AREA. AM NOT ANTICIPATING
SEVERE WEATHER...HOWEVER A FEW STRONG THUNDERSTORMS WILL BE
POSSIBLE EAST OF I-55 DURING THE AFTERNOON. BEST INSTABILITY AND
SHEAR PARAMETERS WILL REMAIN FOCUSED A BIT FURTHER SOUTHWEST
ACROSS THE OZARKS AND LOWER OHIO RIVER VALLEY.
ONCE SURFACE LOW LIFTS INTO THE GREAT LAKES...FRONT WILL GET
PULLED EASTWARD INTO INDIANA BY EARLY EVENING. ALL OPERATIONAL
MODELS SUGGEST PLENTY OF SHOWERS LINGERING BEHIND THE BOUNDARY AT
LEAST THROUGH MIDNIGHT. HAVE THEREFORE MAINTAINED HIGH POPS
THROUGH THE EVENING...WITH STEADILY DECREASING CHANCES AFTER
MIDNIGHT. MAY EVEN BE ENOUGH COLD AIR ADVECTING INTO THE AREA
BEHIND THE FRONT TO CHANGE THE RAIN SHOWERS TO A BRIEF PERIOD OF
SNOW SHOWERS ACROSS THE ILLINOIS RIVER VALLEY OVERNIGHT...HOWEVER
THINK MOST OF THE MOISTURE WILL DEPART BEFORE IT GETS COLD ENOUGH
FOR THAT TO HAPPEN. WILL HOWEVER MENTION JUST A SLIGHT CHANCE FOR
SNOW SHOWERS ACROSS THE FAR WESTERN KILX CWA IN CASE MOISTURE
LINGERS. TOTAL RAINFALL FROM THIS SYSTEM WILL GENERALLY BE BETWEEN
THREE QUARTERS AND ONE INCH...HOWEVER AMOUNTS IN EXCESS OF ONE
INCH WILL BE LIKELY EAST OF I-55 WHERE A FEW STRONGER STORMS MAY OCCUR.
MUCH COOLER/DRIER AIRMASS WILL ARRIVE ON WEDNESDAY AND
THURSDAY...WITH HIGHS DROPPING BACK INTO THE 50S AND OVERNIGHT
LOWS DIPPING INTO THE 30S. MODELS STILL SHOW A NORTHERN-STREAM
SHORT-WAVE TRACKING ACROSS THE UPPER MIDWEST AND GREAT LAKES
WEDNESDAY NIGHT...HOWEVER THINK MOISTURE WILL BE LACKING AND
STRONGEST LIFT WILL REMAIN WELL TO THE NORTH. HAVE THEREFORE ONLY
MENTIONED A CHANCE FOR SPRINKLES/FLURRIES FROM THE PEORIA AREA
NORTHWARD.
LONG TERM...FRIDAY THROUGH MONDAY
MODELS CONTINUE TO STRUGGLE WITH THE POTENTIAL SYSTEM AT THE END
OF THE WEEK. SYSTEM IN QUESTION IS A CUT-OFF LOW OFF THE COAST OF
SOUTHERN CALIFORNIA THAT WILL EVENTUALLY GET ABSORBED INTO THE
PREVAILING W/NW FLOW ACROSS THE CONUS AND GET EJECTED EASTWARD BY
FRIDAY/SATURDAY. GFS HAS CONSISTENTLY BEEN FASTER AND FURTHER
NORTH WITH ITS TRACK...SPREADING RAIN INTO CENTRAL ILLINOIS
FRIDAY/FRIDAY NIGHT. MEANWHILE...ECMWF HAS BEEN CONSISTENTLY
SLOWER AND FURTHER SOUTH...KEEPING MUCH OF THE RAIN ACROSS THE
TENNESSEE AND OHIO RIVER VALLEYS ON SATURDAY/SUNDAY. GEM SUPPORTS
THE SLOWER ECMWF...SO WILL TREND TOWARD THIS SOLUTION FOR THE
EXTENDED. AS A RESULT...HAVE OPTED TO KEEP FRIDAY DRY...WITH LOW
CHANCE POPS ARRIVING FRIDAY NIGHT. AFTER THAT...HAVE CONFINED RAIN
CHANCES TO MAINLY THE SOUTHERN CWA ON SATURDAY...WITH MAIN FOCUS
FOR MORE SIGNIFICANT RAINFALL REMAINING SOUTH OF THE AREA.
BARNES
&&
.AVIATION...
ISSUED 1230 PM CDT MON APR 22 2013
VFR CONDITIONS EXPECTED THROUGH AT LEAST 06Z OVER CENTRAL
ILLINOIS...WITH JUST SOME LOWERING MID AND HIGH CLOUDS. HOWEVER...
CU-RULE AND SOUNDINGS SHOWING SOME SCATTERED CLOUDS AS LOW AS
4000 FEET THIS AFTERNOON FROM KSPI-KCMI. INCOMING COLD FRONT FROM
THE WEST HAS BEEN SLOWING DOWN...SO HAVE BACKED OFF ON THE VCSH
MENTION FOR A FEW HOURS UNTIL AROUND 05Z OR LATER...AND MAY BE
CLOSER TO 12Z TOWARD KDEC/KCMI. ONCE THE FRONT PASSES...SHOWERS
WILL BECOME MORE STEADY AND CEILINGS SHOULD FALL TO AROUND 2000
FEET. CURRENTLY DOES NOT APPEAR TO BE A MAJOR THREAT OF THUNDER...
BUT NAM MODEL INDICATES A LOW POTENTIAL AROUND KCMI TOWARD THE END
OF THE TAF PERIOD...SO WILL NEED TO KEEP AN EYE ON THIS.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
118 PM CDT MON APR 22 2013
.UPDATE...
ISSUED AT 1215 PM CDT MON APR 22 2013
NO MAJOR CHANGES WITH THE ASSORTMENT OF SHORT-RANGE GUIDANCE
COMING IN THIS MORNING. WE ARE SEEING THE HIGHER END POTENTIAL
THROUGH THE ASSORTMENT OF HIGH RESOLUTION WRF SOLUTIONS WE HAVE
ACCESS TO...IN ADDITION TO THE RAP AND HRRR RUNS BETWEEN 14-16Z. THE
HOPWRF /WHICH CAN BE FOUND AT HOPWRF.INFO/ IS NOW OUT THROUGH 06Z
AND THE ENSEMBLE MEAN GIVES MUCH OF SOUTHERN MN AND FAR WEST
CENTRAL WI 0.75"-1.00" LIQUID AND EVEN GIVES SOME AREAS IN SOUTH
CENTRAL MN OVER 1.00". SOUTH CENTRAL MN WAS ALSO AN AREA
HIGHLIGHTED BY THE 22.09Z SREF WITH AT LEAST SOME PERCENT CHANCE
OF >12" SNOW IN 12 HOURS. THE SHORT-TERM GUIDANCE CONTINUES TO
PAINT A 1-2 COUNTY- WIDE SWATH OF 8-12 INCHES SNOWFALL JUST ON THE
NORTH SIDE OF THE RAIN/SNOW LINE. MODEL CONSENSUS PUTS THE
MESOSCALE HEAVY SNOW BAND ALONG A LINE FROM MANKATO...THROUGH THE
TWIN CITIES METRO...AND UP THROUGH RICE LAKE WI. THE 12Z SOUNDING
HERE AT MPX THIS MORNING HAD AT LEAST THE WEST METRO COLD ENOUGH
FOR SNOW RIGHT AT THE ONSET OF PRECIP AND THAT`S WHAT WE ARE
SEEING IN SOUTHWEST MN. FORECAST SOUNDINGS ONLY COOL WITH TIME
TODAY...SO ABOVE THE SURFACE WE ARE GOOD TO GO FOR HEAVY SNOW
ALONG THE LINE MENTIONED ABOVE. THE CAVEAT IS THE NEAR SURFACE
LAYER DUE TO DAYTIME HEATING. WE ARE NOW NEAR 40 OR IN THE LOWER
40S...SO THE SNOWFLAKES MAY TURN TO RAINDROPS 500-1000 FT ABOVE
THE GROUND. SO...WE COULD STILL SEE A 2-3 HOUR WINDOW OF RAIN/SNOW
BEFORE THE CHANGE OVER HAPPENS...AND WE QUICKLY FIND OURSELVES WITH
1-2" PER HOUR RATES. THE SNOW GRADIENT WILL BE EXTREMELY TIGHT.
PERHAPS A 7-8" INCH SNOW GRADIENT OVER THE SPAN OF A SINGLE
COUNTY. WE WILL UNDOUBTEDLY MISS IN SOME AREA WITH THIS KIND OF
GRADIENT. THE TIGHTEST GRADIENT SHOULD BE ALONG THE RAIN/SNOW
LINE...BUT TOTALS SHOULD ALSO QUICKLY FALL TO THE NORTHWEST. SO
EVEN PORTIONS OF THE WESTERN TWIN CITIES METRO AND CERTAINLY ST.
CLOUD WILL SEE LESSER TOTALS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 414 AM CDT MON APR 22 2013
MOTHER NATURE IS AT IT AGAIN! MAJOR CHANGES HAVE BEEN MADE TO THE
SHORT TERM WITH REGARDS TO THE SYSTEM WE HAVE BEEN FOLLOWING FOR THE
PAST FEW DAYS. THE 00Z MODEL RUNS...INCLUDING THE GLOBAL ENSEMBLES
AND MESOSCALE MODELS...HAVE REALLY COME INTO LINE IN SHOWING A
QUICK-HITTING MAJOR WINTER STORM TAKING SHAPE LATER THIS AFTERNOON
AND INTO TONIGHT. IN FACT...THE NAM...GFS...CANADIAN... SREF...AND
GEFS MODELS ARE ALL IN VERY GOOD AGREEMENT LEADING TO A RELATIVELY
HIGH CONFIDENCE FORECAST.
LOW PRESSURE WILL TRACK NORTHEAST FROM THE SOUTHERN PLAINS TO
SOUTHWESTERN WISCONSIN BY MIDNIGHT TONIGHT...THEN TO NORTHEAST
WISCONSIN BY EARLY TUESDAY MORNING. A COLD FRONT WILL SINK SOUTH
ACROSS THE AREA AND STALL ACROSS SCTRL MN/WCTRL WI THIS EVENING.
PRECIPITATION WILL SPREAD OVERHEAD FROM THE SOUTHWEST LATER THIS
MORNING OR INTO THE AFTERNOON. IT WILL BEGIN INITIALLY AS SNOW
ACROSS WRN MN...BUT WARMER AIR ALOFT FURTHER EAST WILL KEEP IT RAIN
UNTIL CAA TO THE NORTH AND WEST OF THE SURFACE LOW TURNS IT TO ALL
SNOW. THIS TRANSITION WILL TAKE PLACE AT NEW ULM AROUND 3 PM...TWIN
CITIES AROUND 5 PM...AND NEW RICHMOND/RICE LAKE AROUND 7 PM.
THINK THE ARRIVAL OF THE COLD AIR WILL BE QUICK ENOUGH ALONG
A LINE FROM A NEW ULM...TWIN CITIES...MORA LINE TO KEEP THE MAJORITY
OF SIGNIFICANT PRECIP AS SNOW WITH THIS SYSTEM. LOCATIONS NEAR THE
STALLED FRONT WILL STILL HAVE MARGINAL THERMAL PROFILES...FAVORING
MORE OF A RAIN/SNOW MIX FOR THE MAJORITY OF THE EVENT. THIS WOULD
INCLUDE EAU CLAIRE AND ALBERT LEA.
VERY IMPRESSIVE FRONTOGENESIS WITHIN THE DENDRITIC GROWTH ZONE TAKES
SHAPE EARLY THIS EVENING WITHIN 40 MILES OF THE AFOREMENTIONED LINE.
THUS...THERE SHOULD BE INTENSE BANDING WITHIN THE LARGER DEFORMATION
AREA WITH SNOW RATES OF 1 TO 2+ INCHES PER HOUR SETTING UP. LATE
SEASON SYSTEMS ARE NOTORIOUS FOR PRODUCING THUNDERSNOW...ESPECIALLY
WITH THIS LEVEL OF FRONTOGENESIS SO ALSO MENTIONED ISOLATED
THUNDERSTORMS TONIGHT.
QPF IS VERY SIMILAR ON THE MODELS MENTIONED...AND WENT WITH A
GFS/NAM/SREF COMBO FOR LIQUID. USING ROUGHLY A 10:1 RATIO TONIGHT
YIELDS A GOOD 6 TO 9 INCHES OF SNOW FROM SWRN MN TO ECTRL MN AND
NWRN WI. THE HIGHEST AMOUNTS ARE EXPECTED IN AND NORTHEAST OF THE
TWIN CITIES METRO WHERE THE DEFORMATION BAND WILL REACH ITS MATURE
PHASE. ISSUED A WINTER STORM WARNING FOR THE MOST OF SRN MN AND WRN
WI...WITH A WINTER WEATHER ADVISORY FOR A ROW OF COUNTIES
SURROUNDING THE WARNING WHERE 3 TO 6 INCHES ARE FORECAST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 347 AM CDT MON APR 22 2013
FORECAST BEGINS WITH THE VESTIGES OF THE LAST HEAVY SNOW
EVENT FOR THE WINTER/SPRING SEASON ENDING ON TUESDAY MORNING
OVER WEST CENTRAL WI. COULD BE ANOTHER QUICK FEW TENTHS TO
NEAR ONE HALF INCH OVER THIS REGION FROM 12Z TO 18Z. EXPECT
SOME SLIGHT BLOWING AND DRIFTING OF HEAVY SNOW OVER EAST CENTRAL
MN AND WEST CENTRAL WI DURING THIS TIME FRAME AS WELL...ASSOCIATED
WITH SUSTAINED NORTHERLY WINDS IN THE 10 TO 20 MPH RANGE. NEW
COATING OF 2 TO 8 INCHES OF SNOW WILL PUT A CAP ON MAX READINGS
FOR TUESDAY. CLOUD COVER SHOULD DECREASE MARKEDLY ON TUESDAY NIGHT.
ONLY ELEMENT KEEPING US FROM PLUNGING BACK INTO THE UPPER SINGLE
DIGITS TO MID TEENS TOMORROW NIGHT IS FAIRLY ROBUST PRESSURE
GRADIENT. THAT SAID...TEMPERATURES WILL STILL BE 10 TO NEAR 15
DEGREES BELOW NORMAL FOR MUCH OF THE CWA.
WEAK SURFACE TROUGH AND MODERATE 50H TROUGH JUST TO ITS LEE WILL
BE THE IMPETUS FOR ANOTHER ROUND OF PCPN WED MORNING INTO THE
EVENING HOURS. USED GFS40 285K ISENTROPIC ANAL FOR PLACEMENT
OF PCPN TRENDS. 850 TEMPS AT THIS JUNCTURE PRETTY MUCH GUARANTEEING
MOST OF EVENT WILL BE OF LIQUID VARIETY. ALTHOUGH MOISTURE WILL
BE LACKING WHEN SUB ZERO TEMPS ALOFT ARE PRESENT WED EVENING
...COULD BE ENOUGH MOISTURE AND FORCING STILL PREVALENT TO PRODUCE
A QUICK FEW TENTHS TO JUST OVER ONE HALF INCH OF SNOW ACROSS
MAINLY WEST CENTRAL WI AND PORTION OF EAST CENTRAL MN.
ZONAL FLOW TAKES OVER AGAIN OVER MUCH OF LOWER 48 BY THURSDAY AFTN.
MID LEVEL TROUGH COULD BRING SLT POPS TO MUCH OF FA FRI AFTN/EVE.
ANOTHER SURFACE TROUGH IMPETUS FOR CHANCE POPS ACROSS MUCH OF FA
SATURDAY NIGHT INTO EARLY MONDAY MORNING. FORCING WITH BOTH SYSTEMS
APPEARS TO BE MINIMAL...WITH QPF READINGS MAINLY IN THE TWO TENTHS
OF AN INCH RANGE OR LESS RANGE ANTICIPATED WITH BOTH SYSTEMS. SOUTH
CENTRAL MN COULD ENCOUNTER A FEW TENTHS OF AN INCH MORE LATE SAT
NIGHT...ASSOCIATED WITH ISOLATED THUNDERSTORM ACTIVITY AS INSTABILITY
INCREASES NOTICEABLY.
TEMPERATURES WILL FINALLY BREACH THE 60 DEGREE MARK ACROSS MUCH OF
THE FA ON FRIDAY...AS WAA INCREASES WITH STRONG SOUTHWESTERLY FLOW
THROUGHOUT THE DAY. TEMPERATURES WILL SLOWLY INCREASE RIGHT INTO THE
WEEKEND...AND RIGHT INTO THE LAST WEEK OF APRIL. FAR AND AWAY THE MOST
NEWSWORTHY ITEM OF THE EXTENDED INVOLVES THE LONG AWAITED APPEARANCE
OF A SIGNIFICANT 50H RIDGE OVER THE UPPER MIDWEST...WHICH WILL
COMMENCE OVER THE DAKOTAS NEXT TUESDAY...AND ENCOMPASS MN AND WI
BY NEXT WEDNESDAY. TEMPERATURES SHOULD EASILY LIFT INTO THE 70S
OVER OUR FA DURING THIS PERIOD...WITH EVEN A CHANCE FOR A FEW
80 DEGREE READINGS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1242 PM CDT MON APR 22 2013
BIG CHANGES TO OUR WEATHER AT THE TERMINALS IS RIGHT ON THE DOOR
STEP. THE SHORT TERM MODELS ARE IN GOOD AGREEMENT SO NO
SIGNIFICANT CHANGES TO THIS SET OF TERMINAL FORECASTS. LOW
PRESSURE OVER WESTERN KANSAS WILL MOVE NORTHEAST TOWARD SOUTHEAST
MINNESOTA THIS EVENING AND THEN INTO THE UPPER PENINSULA OF
MICHIGAN BY MORNING. TREMENDOUS VERTICAL MOTION AND OTHER
ATMOSPHERIC DYNAMICS IN PLACE TO CREATE VERY IMPRESSIVE SNOW
RATES AT KMSP/KRNH. IN FACT THERE IS A SLIGHT CHANCE OF THUNDER
FROM CENTRAL IOWA TO NEAR DLH. WILL NOT CARRY THUNDER IN THE TAFS
AS IT WILL BE EXTREMELY ISOLATED. WITH THE GREAT SNOW RATES WILL
COME REDUCED VISIBILITIES. TEMPERATURES ARE COLD ENOUGH WEST AND
NORTH OF KMSP FOR THE PRECIPITATION TO BEGIN AS SNOW AND REMAIN
ALL SNOW. AS THE LOW MOVES NORTHEAST INTO WISCONSIN THIS EVENING
COLDER AIR WILL FILTER INTO THE EASTERN TERMINALS WITH KEAU
SWITCHING TO ALL SNOW BY 10Z TUESDAY. AIRCRAFT SOUNDINGS INDICATE
THERE IS A 1400 FOOT LAYER OF WARM AIR AT KMSP...THEREFORE EXPECT
KMSP TO HAVE A RASN MIXTURE UNTIL 23-00Z AND THEN ALL SNOW. EAU
SHOULD KEEP A RA/SN MIX GOING THROUGH THE EVENING. A PERIOD OF
HEAVY SNOW EXPECTED FROM EAST OF RWF TO MSP AND RNH THIS EVENING
WITH 1-2 IN/HR SNOW RATES POSSIBLE. THE SNOW WILL TAPER OFF OVER
MIDNIGHT EXCEPT FOR KEAU.
KMSP...VFR CONDITIONS CURRENTLY...WHICH WILL DETERIORATE QUICKLY
AFTER 21Z. RAIN WILL ARRIVE AROUND 1930Z AND A RAIN SNOW MIX WILL
BE NOTED AROUND THE 21Z TIME FRAME. ALL SNOW AROUND 00Z. A PERIOD
OF HEAVY SNOW IS LIKELY THIS EVENING WITH LIFR CONDITIONS...THEN
CONDITIONS WILL IMPROVE AFTER 07Z WITH FLURRIES AFTER 10Z FOR A
FEW HOURS. WINDS WILL BE GUSTY FROM THE NORTH.
/OUTLOOK FOR KMSP/
WED...VFR. CHC MVFR/-RASN AFTN. SW WINDS 10-15 KTS.
THU...VFR. SW WINDS 8-15 KTS.
FRI...VFR. SW WINDS 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WARNING FROM 4 PM THIS AFTERNOON TO 7 AM CDT
TUESDAY FOR MNZ044-045-050>052-058>061-066-068-069-076.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM CDT
TUESDAY FOR MNZ043-049.
WINTER WEATHER ADVISORY UNTIL 1 AM CDT TUESDAY FOR MNZ048-
054>057-064.
WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM CDT TUESDAY
FOR MNZ053-062-063-070-077.
WINTER STORM WARNING UNTIL 1 AM CDT TUESDAY FOR MNZ065-067-
073>075-082-083-091.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM CDT
TUESDAY FOR MNZ078-084-085-092.
WI...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM CDT TUESDAY
FOR WIZ014>016-023.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM CDT
TUESDAY FOR WIZ024-025-027.
&&
$$
UPDATE...CLF
SHORT TERM...BORGHOFF
LONG TERM...AJZ
AVIATION...DRL
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1238 PM CDT MON APR 22 2013
.UPDATE...
ISSUED AT 1215 PM CDT MON APR 22 2013
NO MAJOR CHANGES WITH THE ASSORTMENT OF SHORT-RANGE GUIDANCE
COMING IN THIS MORNING. WE ARE SEEING THE HIGHER END POTENTIAL
THROUGH THE ASSORTMENT OF HIGH RESOLUTION WRF SOLUTIONS WE HAVE
ACCESS TO...IN ADDITION TO THE RAP AND HRRR RUNS BETWEEN 14-16Z. THE
HOPWRF /WHICH CAN BE FOUND AT HOPWRF.INFO/ IS NOW OUT THROUGH 06Z
AND THE ENSEMBLE MEAN GIVES MUCH OF SOUTHERN MN AND FAR WEST
CENTRAL WI 0.75"-1.00" LIQUID AND EVEN GIVES SOME AREAS IN SOUTH
CENTRAL MN OVER 1.00". SOUTH CENTRAL MN WAS ALSO AN AREA
HIGHLIGHTED BY THE 22.09Z SREF WITH AT LEAST SOME PERCENT CHANCE
OF >12" SNOW IN 12 HOURS. THE SHORT-TERM GUIDANCE CONTINUES TO
PAINT A 1-2 COUNTY- WIDE SWATH OF 8-12 INCHES SNOWFALL JUST ON THE
NORTH SIDE OF THE RAIN/SNOW LINE. MODEL CONSENSUS PUTS THE
MESOSCALE HEAVY SNOW BAND ALONG A LINE FROM MANKATO...THROUGH THE
TWIN CITIES METRO...AND UP THROUGH RICE LAKE WI. THE 12Z SOUNDING
HERE AT MPX THIS MORNING HAD AT LEAST THE WEST METRO COLD ENOUGH
FOR SNOW RIGHT AT THE ONSET OF PRECIP AND THAT`S WHAT WE ARE
SEEING IN SOUTHWEST MN. FORECAST SOUNDINGS ONLY COOL WITH TIME
TODAY...SO ABOVE THE SURFACE WE ARE GOOD TO GO FOR HEAVY SNOW
ALONG THE LINE MENTIONED ABOVE. THE CAVEAT IS THE NEAR SURFACE
LAYER DUE TO DAYTIME HEATING. WE ARE NOW NEAR 40 OR IN THE LOWER
40S...SO THE SNOWFLAKES MAY TURN TO RAINDROPS 500-1000 FT ABOVE
THE GROUND. SO...WE COULD STILL SEE A 2-3 HOUR WINDOW OF RAIN/SNOW
BEFORE THE CHANGE OVER HAPPENS...AND WE QUICKLY FIND OURSELVES WITH
1-2" PER HOUR RATES. THE SNOW GRADIENT WILL BE EXTREMELY TIGHT.
PERHAPS A 7-8" INCH SNOW GRADIENT OVER THE SPAN OF A SINGLE
COUNTY. WE WILL UNDOUBTEDLY MISS IN SOME AREA WITH THIS KIND OF
GRADIENT. THE TIGHTEST GRADIENT SHOULD BE ALONG THE RAIN/SNOW
LINE...BUT TOTALS SHOULD ALSO QUICKLY FALL TO THE NORTHWEST. SO
EVEN PORTIONS OF THE WESTERN TWIN CITIES METRO AND CERTAINLY ST.
CLOUD WILL SEE LESSER TOTALS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 414 AM CDT MON APR 22 2013
MOTHER NATURE IS AT IT AGAIN! MAJOR CHANGES HAVE BEEN MADE TO THE
SHORT TERM WITH REGARDS TO THE SYSTEM WE HAVE BEEN FOLLOWING FOR THE
PAST FEW DAYS. THE 00Z MODEL RUNS...INCLUDING THE GLOBAL ENSEMBLES
AND MESOSCALE MODELS...HAVE REALLY COME INTO LINE IN SHOWING A
QUICK-HITTING MAJOR WINTER STORM TAKING SHAPE LATER THIS AFTERNOON
AND INTO TONIGHT. IN FACT...THE NAM...GFS...CANADIAN... SREF...AND
GEFS MODELS ARE ALL IN VERY GOOD AGREEMENT LEADING TO A RELATIVELY
HIGH CONFIDENCE FORECAST.
LOW PRESSURE WILL TRACK NORTHEAST FROM THE SOUTHERN PLAINS TO
SOUTHWESTERN WISCONSIN BY MIDNIGHT TONIGHT...THEN TO NORTHEAST
WISCONSIN BY EARLY TUESDAY MORNING. A COLD FRONT WILL SINK SOUTH
ACROSS THE AREA AND STALL ACROSS SCTRL MN/WCTRL WI THIS EVENING.
PRECIPITATION WILL SPREAD OVERHEAD FROM THE SOUTHWEST LATER THIS
MORNING OR INTO THE AFTERNOON. IT WILL BEGIN INITIALLY AS SNOW
ACROSS WRN MN...BUT WARMER AIR ALOFT FURTHER EAST WILL KEEP IT RAIN
UNTIL CAA TO THE NORTH AND WEST OF THE SURFACE LOW TURNS IT TO ALL
SNOW. THIS TRANSITION WILL TAKE PLACE AT NEW ULM AROUND 3 PM...TWIN
CITIES AROUND 5 PM...AND NEW RICHMOND/RICE LAKE AROUND 7 PM.
THINK THE ARRIVAL OF THE COLD AIR WILL BE QUICK ENOUGH ALONG
A LINE FROM A NEW ULM...TWIN CITIES...MORA LINE TO KEEP THE MAJORITY
OF SIGNIFICANT PRECIP AS SNOW WITH THIS SYSTEM. LOCATIONS NEAR THE
STALLED FRONT WILL STILL HAVE MARGINAL THERMAL PROFILES...FAVORING
MORE OF A RAIN/SNOW MIX FOR THE MAJORITY OF THE EVENT. THIS WOULD
INCLUDE EAU CLAIRE AND ALBERT LEA.
VERY IMPRESSIVE FRONTOGENESIS WITHIN THE DENDRITIC GROWTH ZONE TAKES
SHAPE EARLY THIS EVENING WITHIN 40 MILES OF THE AFOREMENTIONED LINE.
THUS...THERE SHOULD BE INTENSE BANDING WITHIN THE LARGER DEFORMATION
AREA WITH SNOW RATES OF 1 TO 2+ INCHES PER HOUR SETTING UP. LATE
SEASON SYSTEMS ARE NOTORIOUS FOR PRODUCING THUNDERSNOW...ESPECIALLY
WITH THIS LEVEL OF FRONTOGENESIS SO ALSO MENTIONED ISOLATED
THUNDERSTORMS TONIGHT.
QPF IS VERY SIMILAR ON THE MODELS MENTIONED...AND WENT WITH A
GFS/NAM/SREF COMBO FOR LIQUID. USING ROUGHLY A 10:1 RATIO TONIGHT
YIELDS A GOOD 6 TO 9 INCHES OF SNOW FROM SWRN MN TO ECTRL MN AND
NWRN WI. THE HIGHEST AMOUNTS ARE EXPECTED IN AND NORTHEAST OF THE
TWIN CITIES METRO WHERE THE DEFORMATION BAND WILL REACH ITS MATURE
PHASE. ISSUED A WINTER STORM WARNING FOR THE MOST OF SRN MN AND WRN
WI...WITH A WINTER WEATHER ADVISORY FOR A ROW OF COUNTIES
SURROUNDING THE WARNING WHERE 3 TO 6 INCHES ARE FORECAST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 347 AM CDT MON APR 22 2013
FORECAST BEGINS WITH THE VESTIGES OF THE LAST HEAVY SNOW
EVENT FOR THE WINTER/SPRING SEASON ENDING ON TUESDAY MORNING
OVER WEST CENTRAL WI. COULD BE ANOTHER QUICK FEW TENTHS TO
NEAR ONE HALF INCH OVER THIS REGION FROM 12Z TO 18Z. EXPECT
SOME SLIGHT BLOWING AND DRIFTING OF HEAVY SNOW OVER EAST CENTRAL
MN AND WEST CENTRAL WI DURING THIS TIME FRAME AS WELL...ASSOCIATED
WITH SUSTAINED NORTHERLY WINDS IN THE 10 TO 20 MPH RANGE. NEW
COATING OF 2 TO 8 INCHES OF SNOW WILL PUT A CAP ON MAX READINGS
FOR TUESDAY. CLOUD COVER SHOULD DECREASE MARKEDLY ON TUESDAY NIGHT.
ONLY ELEMENT KEEPING US FROM PLUNGING BACK INTO THE UPPER SINGLE
DIGITS TO MID TEENS TOMORROW NIGHT IS FAIRLY ROBUST PRESSURE
GRADIENT. THAT SAID...TEMPERATURES WILL STILL BE 10 TO NEAR 15
DEGREES BELOW NORMAL FOR MUCH OF THE CWA.
WEAK SURFACE TROUGH AND MODERATE 50H TROUGH JUST TO ITS LEE WILL
BE THE IMPETUS FOR ANOTHER ROUND OF PCPN WED MORNING INTO THE
EVENING HOURS. USED GFS40 285K ISENTROPIC ANAL FOR PLACEMENT
OF PCPN TRENDS. 850 TEMPS AT THIS JUNCTURE PRETTY MUCH GUARANTEEING
MOST OF EVENT WILL BE OF LIQUID VARIETY. ALTHOUGH MOISTURE WILL
BE LACKING WHEN SUB ZERO TEMPS ALOFT ARE PRESENT WED EVENING
...COULD BE ENOUGH MOISTURE AND FORCING STILL PREVALENT TO PRODUCE
A QUICK FEW TENTHS TO JUST OVER ONE HALF INCH OF SNOW ACROSS
MAINLY WEST CENTRAL WI AND PORTION OF EAST CENTRAL MN.
ZONAL FLOW TAKES OVER AGAIN OVER MUCH OF LOWER 48 BY THURSDAY AFTN.
MID LEVEL TROUGH COULD BRING SLT POPS TO MUCH OF FA FRI AFTN/EVE.
ANOTHER SURFACE TROUGH IMPETUS FOR CHANCE POPS ACROSS MUCH OF FA
SATURDAY NIGHT INTO EARLY MONDAY MORNING. FORCING WITH BOTH SYSTEMS
APPEARS TO BE MINIMAL...WITH QPF READINGS MAINLY IN THE TWO TENTHS
OF AN INCH RANGE OR LESS RANGE ANTICIPATED WITH BOTH SYSTEMS. SOUTH
CENTRAL MN COULD ENCOUNTER A FEW TENTHS OF AN INCH MORE LATE SAT
NIGHT...ASSOCIATED WITH ISOLATED THUNDERSTORM ACTIVITY AS INSTABILITY
INCREASES NOTICEABLY.
TEMPERATURES WILL FINALLY BREACH THE 60 DEGREE MARK ACROSS MUCH OF
THE FA ON FRIDAY...AS WAA INCREASES WITH STRONG SOUTHWESTERLY FLOW
THROUGHOUT THE DAY. TEMPERATURES WILL SLOWLY INCREASE RIGHT INTO THE
WEEKEND...AND RIGHT INTO THE LAST WEEK OF APRIL. FAR AND AWAY THE MOST
NEWSWORTHY ITEM OF THE EXTENDED INVOLVES THE LONG AWAITED APPEARANCE
OF A SIGNIFICANT 50H RIDGE OVER THE UPPER MIDWEST...WHICH WILL
COMMENCE OVER THE DAKOTAS NEXT TUESDAY...AND ENCOMPASS MN AND WI
BY NEXT WEDNESDAY. TEMPERATURES SHOULD EASILY LIFT INTO THE 70S
OVER OUR FA DURING THIS PERIOD...WITH EVEN A CHANCE FOR A FEW
80 DEGREE READINGS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 645 AM CDT MON APR 22 2013
CONDITIONS AT TAF ISSUANCE TIME RANGE FROM VFR AT AXN/STC TO MVFR
AT RWF/MSP AND IFR AT RNH/EAU. THE STRATUS HAS BEEN ERODING ACROSS
CENTRAL MN AS DRIER AIR ADVECTS IN. CONFIDENCE IS NOT ALL THAT
HIGH OF THIS DRIER AIR REACHING MSP AND EAU...BUT IT COULD REACH
RNH WHERE A TEMPO HAS BEEN INTRODUCED LATE MORNING. PRECIPITATION
WILL SPREAD INTO WRN MN LATE THIS MORNING...AND ACROSS ERN MN/WRN
WI BY MID AFTERNOON. COLDER AIR WILL SINK SOUTH AS THE LOW
APPROACHES AND SHOULD TURN RA TO SN AT MSP AND RNH AROUND 00Z. EAU
SHOULD KEEP A RA/SN MIX GOING THROUGH THE EVENING. A PERIOD OF
HEAVY SNOW EXPECTED FROM RWF TO MSP AND RNH THIS EVENING WITH 1-2
IN/HR SNOW RATES POSSIBLE. CANNOT RULE OUT A RUMBLE OF THUNDER
EITHER. THE SNOW WILL TAPER OFF OVER MIDNIGHT.
KMSP...MVFR CONDITIONS CURRENTLY...WHICH SHOULD PERSIST FOR JUST
ABOUT THE ENTIRE TAF PERIOD. DRIER AIR ACROSS CENTRAL MN COULD
MAKE IT DOWN TO MSP BRIEFLY THIS MORNING...BUT CONFIDENCE WASNT
HIGH ENOUGH TO MENTION IN THE TAFS YET. RAIN WILL ARRIVE MID
AFTERNOON...AND TURN TO SNOW AROUND 00Z. A PERIOD OF HEAVY SNOW IS
LIKELY THIS EVENING WITH LIFR CONDITIONS...THEN CONDITIONS WILL
IMPROVE AFTER 07Z.
/OUTLOOK FOR KMSP/
TUE...MVFR IN THE MRNG...THEN VFR. NW WINDS 10-15 KTS.
WED...VFR. CHC MVFR/-RASN AFTN. SW WINDS 10-15 KTS.
THU...VFR. W WINDS 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WARNING FROM 4 PM THIS AFTERNOON TO 7 AM CDT
TUESDAY FOR MNZ044-045-050>052-058>061-066-068-069-076.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM CDT
TUESDAY FOR MNZ043-049.
WINTER WEATHER ADVISORY UNTIL 1 AM CDT TUESDAY FOR MNZ048-
054>057-064.
WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM CDT TUESDAY
FOR MNZ053-062-063-070-077.
WINTER STORM WARNING UNTIL 1 AM CDT TUESDAY FOR MNZ065-067-
073>075-082-083-091.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM CDT
TUESDAY FOR MNZ078-084-085-092.
WI...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM CDT TUESDAY
FOR WIZ014>016-023.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM CDT
TUESDAY FOR WIZ024-025-027.
&&
$$
UPDATE...CLF
SHORT TERM...BORGHOFF
LONG TERM...AJZ
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS DULUTH MN
1210 AM CDT MON APR 22 2013
.AVIATION...06Z TAFS.
IFR/MVFR CEILINGS COVERED MOST OF THE NORTHLAND THIS EVENING...WITH
DRIZZLE/LIGHT RAIN OR LIGHT SNOW STILL FALLING OVER PORTIONS OF FAR
EASTERN MINNESOTA AND NORTHWEST WISCONSIN. THE PRECIPITATION SHOULD
DIMINISH THROUGH THE REST OF THE NIGHT. CEILINGS WERE STARTING TO
RISE OVER THE WESTERN ZONES...WITH A LARGE CLEAR AREA OVER PORTIONS
OF NORTHWEST MINNESOTA/EASTERN NORTH DAKOTA AND SOUTHEAST MANITOBA.
WE EXPECT THIS TO EXPAND SOUTHEAST OVERNIGHT.
ANOTHER SPRING STORM WILL THEN TAKE AIM ON THE NORTHLAND AS EARLY AS
MONDAY AFTERNOON...BUT MORE SO MONDAY NIGHT. IT WILL BRING LOWER
CEILINGS BACK INTO THE REGION...AND REDUCE VISIBILITIES IN SNOW OVER
MUCH OF NORTHWEST WISCONSIN AND OVER EASTERN MINNESOTA.
&&
.PREV DISCUSSION... /ISSUED 1025 PM CDT SUN APR 21 2013/
UPDATE...
RADAR SHOWS THE MAIN PRECIPITATION AREA MOVING THROUGH FAR EASTERN
MINNESOTA AND NORTHWEST WISCONSIN...AND IT WAS DECREASING IN
INTENSITY. DRIZZLE OR LIGHT SNOW WAS STILL OCCURRING FROM COOK
THROUGH THE TWIN PORTS TOWARD SIREN...BUT THIS SHOULD BE
DIMINISHING AS WELL.
LOOKING AHEAD...THE LATEST NAM IS INDICATING A GREATER THREAT FOR
SOME SIGNIFICANT SNOW OVER A PORTION OF OUR CWA...MAINLY OVER
NORTHWEST WISCONSIN. EVEN AREAS AS FAR WEST AND NORTH AS
BRAINERD...THE TWIN PORTS AND THE NORTH SHORE AREA WILL SEE SOME
ACCUMULATING SNOW. HOW MUCH IS STILL IN QUESTION...AS WE WANT TO
SEE THE GFS/ECMWF BEFORE JUMPING ON HEADLINES. THE NAM DOES SHOW
IMPRESSIVE FGEN OVER OUR CWA...ALONG THE TIGHT THERMAL GRADIENT. IT
DOES LOOK LIKELY WE`LL NEED AT LEAST SOME ADVISORIES...AND IF THE
NAM IS CORRECT...WARNINGS MAY ALSO BE NEEDED ACROSS MUCH OF OUR NORTHWEST
WISCONSIN ZONES. THERE WILL BE A TRANSITION TO MIXED PRECIPITATION OR
LIQUID OVER PORTIONS OF PRICE/SAWYER/IRON COUNTIES WHICH WILL
FURTHER COMPLICATE SNOW AMOUNTS THERE. STAY TUNED TO LATER
FORECASTS AND DISCUSSIONS ON THIS DEVELOPING SPRING STORM.
PREV DISCUSSION... /ISSUED 642 PM CDT SUN APR 21 2013/
UPDATE...
RAIN AND SNOW WAS OCCURRING OVER A GOOD PORTION OF THE EASTERN
HALF OF MINNESOTA INTO WESTERN WISCONSIN THIS EVENING. SNOW WAS
DOMINANT ACROSS THE FAR NORTHERN PORTION OF OUR CWA...AND WAS
OCCURRING AT KDLH. THE RAP AND NAM BOTH INDICATE WET BULB ZERO
LEVELS SHOULD HAVE INCREASED QUITE A BIT BETWEEN 21Z AND 00Z
OVER THE SOUTHERN HALF OF THE CWA. HOWEVER...KDLH REMAINS MOSTLY
SNOW BUT WE DO EXPECT A MIX TO OCCUR AS PRECIP RATES DIMINISH. WE
ADJUSTED PRECIP TYPE/POPS A BIT EARLIER THIS EVENING...AND WILL DO
SO AS THE PRECIP DIMINISHES FROM WEST TO EAST OVERNIGHT.
AVIATION...00Z TAFS
IFR OR MVFR CONDITIONS COVERED THE NORTHLAND THIS EVENING...AND
THAT IS EXPECTED TO CONTINUE OVERNIGHT. AN AREA OF SNOW/RAIN
COVERED MOST OF NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN...WITH
RADAR SHOWING THE PRECIPITATION DIMINISHING FROM WEST TO EAST. THAT
TREND WILL CONTINUE OVERNIGHT...WITH MOST OF THE PRECIPITATION
EXITING EASTERN MINNESOTA BETWEEN 03-06Z...AND NORTHWEST
WISCONSIN BETWEEN 05-08Z. IFR OR MVFR CONDITIONS WILL REMAIN...AND
WE EXPECT IMPROVEMENT MONDAY MORNING...BEFORE YET ANOTHER SYSTEM
WILL BRING LOWER CEILINGS AND MORE SNOW TO THE NORTHLAND. THE BEST
CHANCE FOR ADDITIONAL SNOW WILL BE OVER EAST CENTRAL MINNESOTA AND
NORTHWEST WISCONSIN OVER OUR CWA.
PREV DISCUSSION... /ISSUED 306 PM CDT SUN APR 21 2013/
SHORT TERM.../NOW - MONDAY/
THROUGH TONIGHT...THE FOCUS FOR THIS FORECAST IS THE PCPN
ASSOCIATED WITH AN APPROACHING COLD FRONT THAT IS ALREADY MOVING
INTO THE WESTERN FORECAST AREA. THE NORTHLAND IS EXPECTED TO HAVE
THIS PCPN MOVE THROUGH THE REGION FROM WEST TO EAST THROUGH
TONIGHT. WHILE ARE MOSTLY FORECASTING RAIN WITH LITTLE TO NO SNOW
ACCUMULATION...THERE IS STILL SOME UNCERTAINTY AS TO PCPN TYPE AND
SNOWFALL ACCUMULATION SINCE THE TEMPERATURES ACROSS THE NORTHLAND
ARE ONLY IN THE MID TO UPPER 30S. BASED ON MODEL SOUNDINGS...THE
SNOW IS DEFINITELY FALLING AS SNOW ALOFT...BUT THEN ENCOUNTERING
MELTING CLOSE TO THE SURFACE. IT MAY BE THAT THE PCPN BEGINS AS
RAIN...BUT AS THE TEMPERATURES FALL WITH THE PCPN...TRANSITIONS TO
SNOW. FOR AREAS THAT DO GET SNOW...THERE IS THE QUESTION OF
ACCUMULATION BECAUSE THE TEMPERATURES IN THE LOW TO MID 30S MAY
MELT MUCH OF WHAT FALLS. I AM ONLY REASONABLY CONFIDENT THAT THE
ARROWHEAD WILL SEE ANY SIGNIFICANT ACCUMULATION...PERHAPS UP TO 2
INCHES...DUE TO THE LOWER TEMPERATURES. I INCREASED THE SNOWFALL
FORECAST ACROSS THE REST OF THE NORTHLAND TOO...BUT GENERALLY GAVE
A HALF INCH OR LESS OF ACCUMULATION. WE WILL NEED TO MONITOR THE
PCPN OVER THE NEXT FEW HOURS AND SEE HOW QUICKLY THE PCPN
TRANSITIONS TO SNOW. IT MAY BE SOME AREAS GET A SURPRISE 1 OR 2
INCHES OF SNOW. THE COLD FRONT...CURRENTLY IN THE EASTERN
DAKOTAS...WILL MOVE THROUGH THE NORTHLAND THIS EVENING. THERE
SHOULD BE SOME PARTIAL CLEARING ACROSS THE FORECAST AREA IN THE
WAKE OF THE FRONT LATE TONIGHT. OVERNIGHT LOWS WILL RANGE FROM THE
MID 30S ACROSS THE FAR SE FORECAST AREA TO THE MID TO UPPER 20S
ACROSS THE WEST AND NORTH.
MONDAY...THE COLD FRONT WILL STALL FROM IOWA TO UPPER PENINSULA
MICHIGAN AS A LOW PRESSURE CENTER BEGINS TO DEVELOP ALONG THE
FRONT IN THE MISSOURI AREA. THE MODELS CONTINUE TO INDICATE PCPN
ON THE WESTERN SIDE OF THE FRONT WILL BEGIN TO SPREAD FROM EASTERN
SOUTH DAKOTA AND SOUTHERN MINNESOTA INTO NE MINNESOTA AND NW
WISCONSIN DURING THE AFTERNOON. THE MODELS AND SOUNDINGS SEEM TO
FAVOR SNOW...BUT THE SURFACE TEMPERATURES IN THE UPPER 30S TO MID
40S WILL PROBABLY RESULT IN SOME MELTING TO RAIN DURING THE
AFTERNOON...ESPECIALLY FOR NW WISCONSIN. HOWEVER...THIS WILL BE
ANOTHER TRICKY SITUATION THAT WILL NEED TO BE LOOKED INTO MORE
BECAUSE IT COULD JUST AS EASILY MEAN IN UP TO A FEW INCHES OF SNOW
ACCUMULATION FOR SOME PARTS OF THE FORECAST AREA DURING THE
AFTERNOON. THE PCPN WILL LIKELY THAN TRANSITION TO SNOW MONDAY
EVENING.
LONG TERM.../MONDAY NIGHT - SATURDAY/
SNOW WILL LIKELY BE ONGOING AT THE START OF THE PERIOD...AS
FAVORABLE JET DYNAMICS COME INTO PLAY ACROSS THE NORTHLAND. STRONG
ASCENT IN THE RIGHT ENTRANCE REGION OF THE 115 KNOT JET SEGMENT
MOVING ACROSS MN AND INTO ONTARIO WILL AID IN PROVIDING PLENTY OF
FORCING FOR WIDESPREAD PRECIPITATION ACROSS PORTIONS OF MN AND WI.
THE MODELS GENERALLY SHOW A GREAT DEAL OF UPPER LEVEL DIVERGENCE AS
ANOTHER STRONG JET SEGMENT ALSO LIFTS INTO THE WESTERN GREAT LAKES
FROM THE PLAINS. THE NAM...GFS AND ECMWF ALL SHOW A STRONG
BAROCLINIC ZONE ACROSS SE MN AND MUCH OF THE NW 1/2 OF WI...ALONG
WITH A STRONG LLJ OF 30-40 KT. COULD BE A FEW INCHES OF SNOW ACROSS
NE MN AND SEVERAL INCHES OF SNOW ACROSS NW WI. A DISTINCT WARMING
TREND WILL THEN TAKE PLACE ACROSS THE REGION...ALTHOUGH IT WILL BE A
BIT UNSETTLED FOR THE REMAINDER OF THE EXTENDED AS A FEW LOW
PRESSURE SYSTEMS WILL MOVE THROUGH THE REGION.
&&
.POINT TEMPS/POPS...
DLH 41 26 41 23 / 50 60 20 10
INL 39 20 39 22 / 0 10 10 10
BRD 40 24 41 23 / 40 20 10 10
HYR 46 28 42 23 / 60 80 30 10
ASX 45 31 41 25 / 40 80 40 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS GLASGOW MT
731 PM MDT TUE APR 23 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH THURSDAY...
UPDATE FORTHCOMING TO ADDRESS CURRENT TRENDS WITH SHOWERS AND PRECIP
TYPE. REMOVED THUNDER MENTION FOR THIS EVENING. 19Z HRRR MODEL SEEMS
TO HAVE THE BEST HANDLE ON CURRENT ACTIVITY BUT NAM AND GFS CONTINUE
TO CARRY HIGHER QPFS FOR THE SE ZONES LATER TONIGHT. MADE MINOR
TWEAKS TO EVENING POPS BUT RAISED THEM INTO THE LIKELY CATEGORY FOR
THE SE ZONES LATE TONIGHT. REST OF FORECAST LOOKED GOOD. JAMBA
PREVIOUS SHORT TERM DISCUSSION...
SYNOPTIC SET UP... NORTHWEST FLOW CURRENTLY EXISTS ACROSS EASTERN
MONTANA WITH A SHORTWAVE TROUGH MOVING DOWN THE LO OUT OF THE
CANADIAN HIGH PLAINS. NORTHWEST FLOW CURRENTLY EXTENDS BACK TO
PACIFIC NORTHWEST. JUST OFF THE NORTH AMERICAN COAST A LARGE RIDGE
IS BUILDING FROM OREGON NORTH TO SOUTHERN ALASKA WHILE A CLOSED
LOW IS SLOWLY PUSHING INTO SOUTHERN CALIFORNIA.
LATE THIS AFTERNOON THROUGH TONIGHT... SHOWERS AND THUNDERSTORMS
ARE ANTICIPATED TO INITIATE ACROSS THE INTERNATIONAL BORDER AND
DROP SOUTH ACROSS THE CWA THIS AFTERNOON. AS OF 1 PM A FEW LIGHT
RADAR ECHOS ARE ALREADY SHOWING SOME DEVELOPMENT OVER SOUTHERN
SASKATCHEWAN MOVING INTO NORTHERN PHILLIPS AND VALLEY COUNTY.
ENOUGH INSTABILITY EXISTS TO GENERATE A FEW CLAPS OF THUNDER AND
POSSIBLY PEA SIZED HAIL BEFORE THE EVENING IS UP. NAM PROFILE
SOUNDINGS ANTICIPATE THE EVENT TO SLOWLY TRANSITION BACK TO REGULAR
STRATIFORM SHOWERS BY AROUND 8 PM. THEN AS MIDNIGHT APPROACHES
WETBULBS MAY DROP BELOW ZERO AND ANY SHOWERS ACROSS THE AREA
SHOULD FURTHER TRANSITION TO SNOW THROUGH WEDNESDAY MORNING.
WEDNESDAY AFTERNOON THROUGH THURSDAY... A WEAK RIDGE IN THE
NORTHWEST FLOW WILL NUDGE NORTHEAST MONTANA INTO THE WARMER SIDE
OF THE FLOW. 850 MB TEMPERATURES ARE ANTICIPATED TO RIDE UP INTO
POSITIVE DOUBLE DIGITS CELSIUS BY THURSDAY. A SLIGHT DOWNSLOPE
COMPONENT TO WINDS SHOULD ALSO HELP TO DRY OUT THE AREA FURTHER
AND ALLOW FOR SLIGHTLY WARMER TEMPERATURES. DAYTIME HIGHS BY
THURSDAY SHOULD REACH INTO THE 60S AND 50S AREA WIDE WITH MAYBE A
70 POSSIBLE IN THE MISSOURI BREAKS. GAH
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
NO SIGNIFICANT CHANGES IN THE EXTENDED...JUST A FEW TWEAKS TO
WINDS AND SKY. ONE CONCERN COULD BE THE TEMPERATURES ACROSS THE
AREA FROM SCOBEY TO PLENTYWOOD THAT STILL HAS UP TO 10 INCHES OF
SNOW ON THE GROUND. THERE SHOULD BE SOME NOTICEABLE SNOWMELT THIS
WEEK THOUGH MAKING THE FORECAST A BIT MORE DIFFICULT IN THOSE
AREAS. OVERALL WE START OUT WITH A ZONAL SURFACE FLOW ACROSS THE
AREA AND THEN HAVE A LOWER PRESSURE SYSTEM SKIRT THE CANADIAN/US
BORDER. THAT WILL DRAG A BIT OF A FRONT THROUGH IT AND THERE COULD
BE SOME SHOWERS ON SUNDAY INTO MONDAY AND TUESDAY BUT THE MODELS
ARE A BIT DIFFERENT ON THE TIMING AND PLACEMENT OF THOSE ISOLATED SHOWERS.
THERE IS NOT MUCH MOISTURE ASSOCIATED WITH IT THOUGH IN ANY OF THE
MODELS. THE GFS MOVES THINGS THROUGH QUICKER THAN THE EC AND THAT
HAS BEEN THE PATTERN THE LAST TWO DAYS SO THE FORECAST HAS BEEN A
BLEND OF THE TWO. FRANSEN
PREVIOUS DISCUSSION...THE EXTENDED FORECAST PLACES NORTHEAST
MONTANA WITHIN A REGIME OF NORTHWEST FLOW ALOFT. QUICK MOVING
UPPER LEVEL FEATURES PROPAGATING THROUGH THIS FLOW WILL
PERIODICALLY PROVIDE FOR CHANCES OF PRECIPITATION. TIMING AND
PRECISE TRACK OF THESE FEATURES WILL DICTATE WHERE AND WHEN ANY
PRECIPITATION OCCURS. ONE THING THAT IS BECOMING CLEAR
HOWEVER...IS THAT THE LONG RANGE LOOKS MUCH WARMER. THIS WILL
ENSURE THAT ANY PRECIPITATION THAT DOES OCCUR WITH PERIODIC
FRONTAL PASSAGES WILL PRIMARILY BE IN THE FORM OF RAIN.
BOTH THE LATEST ECMWF AND 00Z GFS SHOW VERY WARM 850MB
TEMPERATURES FOR FRIDAY LASTING INTO THE WEEKEND. IN
FACT...INDICATIONS ARE THAT THEY WILL APPROACH +10C TO +15C BY
LATE FRIDAY AFTERNOON. THIS WILL SUPPORT TEMPERATURES APPROACHING
70 IN THE SOUTHERN ZONES...60S IN THE CENTRAL PORTIONS OF THE
CWA...AND 50S IN THE FAR NORTHEAST. A WEAK UPPER LEVEL FEATURE MAY
BRING POSSIBLE SHOWERS IN THE NORTH...BUT THERE IS NOT
MUCH MOISTURE AND SO ONLY HAVE SLIGHT CHANCE IN THE GRIDS. WILL
COOL THINGS OF IN THE NORTHEAST JUST A FEW DEGREES ON SATURDAY AND
SUNDAY WITH 850MB TEMPERATURES DROPPING JUST A NOTCH IN THOSE
LOCATIONS.
SUNDAY NIGHT THROUGH TUESDAY...MODELS ARE SHOWING A COLD FRONT
APPROACHING THE CWA SOMETIME SUNDAY NIGHT OR MONDAY MORNING WITH
AN UPPER LEVEL SHORTWAVE TROUGH DIGGING DOWN FROM THE PACIFIC
NORTHWEST. THIS WILL PROVIDE PROBABLY THE BEST CHANCES FOR ANY
SHOWER ACTIVITY ACROSS THE REGION AND IT WILL RESULT IN COOLER
TEMPERATURES FOR EARLY NEXT WEEK. THERE ARE TIMING DIFFERENCES
HERE THOUGH WITH THE GFS MORE PROGRESSIVE WANTING TO TAKE THE
FRONTAL PASSAGE IN SUNDAY AFTERNOON...THE ECMWF HOLDING OFF UNTIL
SUNDAY NIGHT. ONCE MODELS COME INTO BETTER AGREEMENT ON
TIMING...FUTURE SHIFTS MAY WISH TO RAMP POPS UP DURING THIS
PERIOD. REGARDLESS...BOTH MODELS SHOW ONCE AGAIN MODERATING
TEMPERATURES BY TUESDAY AND BEYOND. THEREFORE...DESPITE PERIODIC
CHANCES FOR SHOWER ACTIVITY IT DOES LOOK LIKE NORTHEAST MONTANA
WILL FINALLY GET A VERY MUCH DESERVED TASTE OF SPRING IN THE
EXTENDED.
ADDITIONAL PRECIPITATION CHANCES WILL BE POSSIBLE THROUGH THE
MIDDLE OF NEXT WEEK. WHILE TIMING DIFFERENCES EXIST...MODELS ARE
INDICATING THAT NORTHEAST MONTANA WILL BECOME INFLUENCED BY
SOUTHWEST FLOW ALOFT TOWARDS THE MIDDLE PORTIONS OF NEXT
WEEK...WITH VARIOUS UPPER LEVEL SHORTWAVE FEATURES PROPAGATING
THROUGH THE FLOW. DUE TO UNCERTAINTIES IN TRACK/TIMING THIS FAR
OUT...KEPT SLIGHT CHANCE FOR SHOWERS IN THE GRIDS FOR NOW. MALIAWCO
&&
.AVIATION...
MAINLY VFR CONDITIONS ARE EXPECTED THIS EVENING...BUT MAY BRIEFLY
BE INTERRUPTED BY A FEW SCATTERED SHOWERS WITH ISOLATED IFR CONDITIONS.
AS TEMPERATURES DROP QUICKLY TONIGHT... A MIX OF RAIN AND SNOW
SHOWERS ARE POSSIBLE THROUGH THE OVERNIGHT HOURS.
NORTHERLY OR NORTHWESTERLY WINDS AROUND 20 KTS WITH STRONGER GUSTS WILL
PERSIST EARLY THIS EVENING AND IMPACT THE TAF SITE WITH OCCASIONAL
SQUALLS...THEN DIMINISH LATER TONIGHT. BMICKELSON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS RALEIGH NC
245 PM EDT MON APR 22 2013
.SYNOPSIS...
AN AREA OF HIGH PRESSURE WILL EXTEND ACROSS THE PIEDMONT TODAY
THROUGH TUESDAY. MEANWHILE A LOW PRESSURE SYSTEM WILL DEVELOP OFF
THE SOUTHEAST COAST TODAY...THEN TRACK NORTHEAST JUST OFF THE EAST
COAST TONIGHT THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 AM MONDAY...
A COLD NORTHEASTERLY BREEZE CONTINUES THIS MORNING BETWEEN A STRONG
HIGH PRESSURE RIDGE OVER THE PIEDMONT AND AN AMPLIFYING COASTAL
TROUGH. STRATUS OVER THE COASTAL AREAS IS BEGINNING TO PUSH INLAND
AND 1000-2000 FT CEILINGS ARE SHOWING UP IN A FEW OBSERVATIONS EAST
OF I-95. THIS TREND WILL CONTINUE THROUGHOUT THE DAY AS ANOTHER
SHALLOW UPPER LEVEL DISTURBANCE CROSSES THE AREA THIS AFTERNOON AND
CAUSES WEAK CYCLOGENESIS EAST OF WILMINGTON THIS EVENING. 12Z RAOB
ANALYSIS SHOWS AN EASTERLY 850MB WIND AT KMHX AND KWAL...WHICH THE
LARGER SCALE MODELS WERE FORECASTING TO BE NORTH-NORTHEASTERLY AT
THIS TIME. STRONGER WARM ADVECTION AT 850MB MAY LEAD TO A MORE
AGGRESSIVE INLAND PUSH OF LOW CLOUDS...BUT MOISTURE IS VERY SHALLOW
AND THE RAP MODEL KEEPS MEASURABLE PRECIP MOSTLY EAST OF THE CWA.
THERMAL ADVECTION BELOW 850MB APPEARS TO NEARLY NEUTRAL...BUT
STRENGTHENING NORTHEASTERLY FLOW THIS AFTERNOON WILL STILL KEEP
HIGHS 10-15 DEGREES NORMAL. THUS...THE ONLY CHANGES THIS MORNING
WILL BE TO ADJUST SKY COVER TRENDS AND LOWER HIGHS A COUPLE DEGREES
OVER THE COASTAL PLAIN. HIGHS IN THE MID 50S EAST TO LOWER 60S
WEST. -SMITH
TONIGHT...LOW CLOUDS WILL LINGER AS THE SFC WAVE LIFTS NEWD JUST OFF
THE NC COAST. LOW LEVEL WINDS WILL BECOME MORE NLY VERSUS NELY BY
DAYBREAK. OVERCAST SKIES AND STEADY SFC WINDS WILL MAINTAIN TEMPS IN
THE LOW-MID 40S OVERNIGHT. IF CLOUD DECK THINS/DISSIPATE IN THE
WEST...COULD SEE A FEW SPOTS COOL INTO THE UPPER 30S.
TUESDAY...SFC WAVE OFF THE NC COAST EARLY TUESDAY MORNING WILL LIFT
QUICKLY NWD AS MID LEVEL TROUGH EXITS OFFSHORE. SUBSIDENCE BEHIND
THE DEPARTING SYSTEM AND ADVECTION OF DRIER AIR WILL AID TO
DISSIPATE THE LOW CLOUDS ACROSS THE REGION FROM WEST-TO-EAST.
INCREASING SUN WILL AID TO WARM TEMPS BACK INTO THE 60S TO NEAR 70
IN THE AFTERNOON WITH THE COOLER TEMPS IN THE FAR NORTHERN COASTAL
PLAIN WHICH WILL LIKELY HOLD ONTO SOME DECENT CLOUD COVERAGE UNTIL
MID AFTERNOON.
TUESDAY NIGHT...WEAK HIGH PRESSURE WILL EXTEND ACROSS THE REGION AT
THE SURFACE WHILE S/W RIDGE ALOFT SCOOTS EWD. BACKING W-SW FLOW
BEHIND THE DEPARTING MID LEVEL RIDGE WILL ADVECT MID-HIGH LEVEL
MOISTURE INTO CENTRAL NC. THIS WILL LEAD TO AN INCREASE IN HIGH
CLOUDS BY EARLY WEDNESDAY MORNING. RESIDUAL LOW LEVEL MOISTURE WILL
LIKELY CAUSE PATCHES OF FOG OR LOW CLOUDS TO DEVELOP. HOWEVER IF
HIGH CLOUDS ARRIVE SOONER OR THICKER THAN EXPECTED...THIS WILL DETER
DEVELOPMENT OF SIGNIFICANT FOG/LOW CLOUDS. MIN TEMPS TUESDAY NIGHT
3-6 DEGREES WARMER THAN TONIGHT WITH MIN TEMPS MID-UPPER 40S.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 235 PM MONDAY...
FOR WEDNESDAY: RISING SURFACE DEW POINTS WITHIN FAIRLY STABLE LOW
LEVELS... A DEPARTING SURFACE RIDGE... VERY LIGHT SURFACE FLOW FROM
THE SOUTHWEST... AND A LACK OF CLOUDS ALL SUPPORT AT LEAST PATCHY
FOG HOLDING INTO MID MORNING... ALTHOUGH WITH A BIT MORE MOISTURE
AND STRONGER LOW LEVEL FLOW IN THE TRIAD REGION... STRATUS MAY
DOMINATE HERE. AS THE WEAK SURFACE HIGH SHIFTS OFF THE SOUTHEAST
COAST WEDNESDAY... SOUTHWESTERLY FLOW FLOW WILL STRENGTHEN OVER
CENTRAL NC AHEAD OF THE COLD FRONT PROJECTED TO PUSH INTO WRN NC
EARLY-MID AFTERNOON. WE WILL STILL BE DOMINATED BY THE MID LEVEL
RIDGING AND DRY AIR HOWEVER... WITH A PROMINENT WARM NOSE AT 800-700
MB... SO INSTABILITY WILL BE LOW TO ABSENT AND MUCH OF THE DAY WILL
REMAIN DRY. THE EXCEPTION WILL BE THE TRIAD... WHICH SHOULD SEE A
FEW SHOWERS/STORMS MOVING IN VERY LATE IN THE AFTERNOON...
ACCOMPANYING THE RISING MID LEVEL LAPSE RATES TO OVER 6 C/KM AND THE
INCREASING LOW LEVEL MOISTURE TRANSPORT. BUT WITH THE MID LEVEL
VORTICITY SHEARING OFF QUICKLY NE ALONG THE APPALACHIANS ALONG WITH
THE MEAGER LOW LEVEL JET (JUST 20-25 KTS)... ANY PRECIP SHOULD BE
VERY LIGHT AND PATCHY. SREF PROBABILITIES OF MEASURABLE RAIN SUPPORT
THIS WITH ONLY LOW CHANCES GETTING INTO THE NW CWA TOWARD EVENING.
ABOVE-NORMAL THICKNESSES (PROJECTED TO CLIMB ABOVE 1380 METERS)
TEMPERED BY INCREASING HIGH CLOUDS THROUGH THE DAY AND SCATTERED
FLAT CUMULUS IN THE AFTERNOON SUPPORT HIGHS OF 74-80... VALUES ALSO
INDICATED BY THE DRY ADIABATIC LOW LEVEL THERMAL STRUCTURE.
FOR WEDNESDAY NIGHT/THURSDAY: AS THE MID LEVEL FLOW OVER OUR REGION
BECOMES ROUGHLY PARALLEL TO THE SURFACE FRONT... BETWEEN THE FIRST
SHORTWAVE TROUGH THAT SHEARS TO THE NORTHEAST TOWARD SE CANADA AND
THE SECOND SHOT OF SHORTWAVE ENERGY WHICH CROSSES THE UPPER MIDWEST
AND GREAT LAKES...THE SURFACE FRONT IS LIKELY TO MAKE ONLY A VERY
SLOW SOUTHEASTWARD PROGRESSION ACROSS NC WEDNESDAY NIGHT INTO EARLY
THURSDAY. GIVEN THE ANAFRONTAL STRUCTURE TO THIS SYSTEM... WE SHOULD
SEE RAIN AND A FEW STORMS SPREADING SLOWLY EAST WEDNESDAY NIGHT JUST
BEHIND THE FRONT. THE MID LEVEL VORTICITY AND LOW LEVEL JET BOTH
SHEARING OFF TO OUR NORTHEAST... ALONG WITH THE UPPER DIVERGENCE
MAX... WILL RESULT IN WANING DYNAMIC FORCING FOR ASCENT. BUT
STEEPENING MID LEVEL LAPSE RATES (TO OVER 6.25 C/KM) AND THE
POTENTIAL FOR ELEVATED CONVECTION (MUCAPE OF 100-200 J/KG) SHOULD
OFFSET THIS ENOUGH FOR CHANCE POPS... GIVEN THE ANTICIPATED CLIMB IN
PRECIP WATER VALUES TO AROUND 1.25 IN. WILL FOCUS THE HIGHEST POPS
LATE WEDNESDAY EVENING THROUGH EARLY THURSDAY MORNING OVER THE WRN
AND NRN PIEDMONT... BUT WILL LIMIT POPS TO JUST CHANCE. SREF
PROBABILITIES OF MEASURABLE RAIN START OFF NEAR 50% OVER THE
MOUNTAINS WEDNESDAY EVENING BUT FALL OFF QUICKLY WEDNESDAY NIGHT AS
THE FRONT SWEEPS EASTWARD... FURTHER SUPPORTING KEEPING POPS AND
AMOUNTS ON THE LOW END. PRECIP SHOULD TAPER OFF TO PATCHY DRIZZLE
LATE WEDNESDAY NIGHT (IN NW) THROUGH THURSDAY MORNING AS THE MID
LEVEL DRY OUT A BIT. AS THE MID LEVEL TROUGH MOVES THROUGH THE GREAT
LAKES INTO THE ST LAWRENCE VALLEY AND HELPS KICK THE SURFACE-850 MB
FRONTAL ZONE TO OUR SE THURSDAY AFTERNOON... MODEL FORECAST
SOUNDINGS SHOW ENOUGH DRYING JUST OFF THE SURFACE WITH AN INCREASING
DOWNSLOPE COMPONENT FOR SLOWLY CLEARING SKIES WEST-TO-EAST IN THE
AFTERNOON. HOWEVER.. CONFIDENCE IN SUCH CLEARING IS USUALLY REDUCED
IN THESE SITUATIONS WITH A MESOHIGH BEHIND AN ANAFRONT... AS THE
FLOW IS TYPICALLY TOO LIGHT AND VERTICAL MOTIONS TOO WEAK TO
DISPERSE THE RESIDUAL LOW LEVEL MOISTURE. AS A RESULT WILL BE MORE
PESSIMISTIC WITH CLOUD COVER THURSDAY... AND WILL HOLD ONTO THE
EARLIER FORECAST OF BELOW NORMAL TEMPS... ALTHOUGH A GREATER
DURATION OF LOW LEVEL DOWNSLOPE COMPONENT FLOW SHOULD YIELD SOME
AFTERNOON RECOVERY IN THE WRN FORECAST AREA... PLUS THE BRUNT OF THE
COOLER POST-FRONTAL AIR WILL BE SLOWED BY THE MOUNTAINS. MORNING
LOWS 50-58. HIGHS 64-72. -GIH
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 245 PM MONDAY...
FOR THURSDAY NIGHT THROUGH FRIDAY NIGHT: THE MID LEVEL TROUGH AXIS
WILL PUSH TO OUR EAST THURSDAY NIGHT WITH THE COLD FRONT SLIPPING TO
OUR SOUTHEAST... AS A LARGE HIGH PRESSURE AREA BUILDS IN FROM THE
MISS VALLEY. EXPECT GRADUALLY CLEARING SKIES OVERNIGHT... ALTHOUGH
FORECAST SOUNDINGS SUGGEST THAT SHALLOW FOG BANKS ARE POSSIBLE.
PLEASANT AND DRY WEATHER AND SLIGHTLY BELOW-NORMAL TEMPS SHOULD
FOLLOW ON FRIDAY AS THE SURFACE HIGH RIDGES INTO NC WHILE ITS CENTER
CROSSES THE OHIO VALLEY HEADING TOWARD THE MIDATLANTIC REGION.
MODELS SHOW THE HIGH SHIFTING NE OFF THE MIDATLANTIC COAST TO NEW
ENGLAND FRIDAY NIGHT... PROPELLED BY ANOTHER SHORTWAVE TROUGH
CROSSING THE CENTRAL CONUS. THE ENSUING RETURN FLOW FROM THE
SOUTHEAST ALONG WITH INCREASING MID-HIGH LEVEL MOISTURE FROM THE WSW
SHOULD BRING AN INCREASE IN CLOUDS THROUGH FRIDAY NIGHT. TEMPS ABOUT
A CATEGORY BELOW NORMAL.
FOR SATURDAY THROUGH MONDAY: HIGH DEGREE OF FORECAST UNCERTAINTY AS
THE GFS/ECMWF BEGIN TO DIFFER CONSIDERABLY REGARDING THE CENTRAL US
TROUGH. BOTH INDICATE A POSITIVE TILT TO THE TROUGH ON SATURDAY...
BUT THE ECMWF EVOLVES INTO A SPLIT FLOW WITH A MORE AMPLIFIED AND
SLOWER WAVE THROUGH THE PLAINS COMPARED TO THE GFS. THE ECMWF THEN
DEVELOPS THIS INTO A CLOSED LOW TO OUR NORTH WITH A TROUGH COVERING
THE EASTERN CONUS SATURDAY NIGHT THROUGH MONDAY... WHILE THE GFS
TAKES THE WEAKER WAVE SWIFTLY OFFSHORE SUNDAY WITH MID LEVEL RIDGING
BUILDING OVER THE EASTERN CONUS BY MONDAY. RECENT GFS RUNS HAVE BEEN
TRENDING MORE AMPLIFIED AND SLOWER WITH THE WAVE... AND IT MAY BE
TOO EASILY KEEPING THE STREAMS PHASED... SO A LEAN TOWARD THE ECMWF
IS PREFERRED. THIS WILL MEAN A SLOWLY APPROACHING TROUGH FROM THE
WEST THROUGH MONDAY... RESULTING IN RAIN CHANCES FROM SATURDAY NIGHT
INTO MONDAY. THE OFFSHORE-DRIFTING SURFACE HIGH MAY DEPOSIT ENOUGH
COOL AIR IN THE PIEDMONT FOR AN IN SITU DAMMING EVENT. WILL LEAVE
TEMPS BELOW NORMAL THROUGH THE PERIOD... WITH SOME REBOUND IN TEMPS
MONDAY AS AN EDGE BACK TOWARD CLIMATOLOGY WITH A POSSIBLE WEAKENING
OF ANY WEDGE AIR MASS. -GIH
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 140 PM MONDAY...
DESPITE QUITE A BIT OF LOW LEVEL MOISTURE ALONG THE NC COAST AND A
STEADY 10-15KT NORTHEASTERLY WIND...LOW CLOUDS HAVE STRUGGLED TO
MOVE INLAND PAST THE I-95 CORRIDOR TODAY. KRWI AND KFAY HAVE
REPORTED PERIODS OF MVFR CEILINGS...TYPICALLY LASTING NO LONGER THAN
THAN AN HOUR OR TWO. BECAUSE OF THIS...CONFIDENCE IS BELOW AVERAGE
REGARDING WHEN LOW CLOUDS WILL SPREAD WEST TO KRDU AND EVENTUALLY
KGSO/KINT TONIGHT. EXPECT CEILINGS WILL REDEVELOP AT KRWI AND KFAY
BY THIS EVENING AS A LOW PRESSURE DEVELOPS OFFSHORE AND MOVES ALONG
THE COAST...LOWERING BELOW 2000FT AROUND MIDNIGHT AND REMAINING
THERE UNTIL LATE TUESDAY MORNING. FURTHER WEST...MVFR CEILINGS WILL
BE A LITTLE HIGHER AT KRDU BUT SHOULD STILL FALL BELOW 2000 FT BY
09Z. AT KGSO/KINT...CEILINGS MAY HOLD AT 2500 FT AND SCATTER OUT BY
MID MORNING AS THE SURFACE LOW MOVES NORTHEAST AWAY FROM THE AREA.
SURFACE WINDS WILL REMAIN UP OVERNIGHT...RANGING FROM 6-8KT IN THE
WEST TO AS HIGH AS 12-14KT IN THE EAST.
OUTLOOK...
AN APPROACHING FRONTAL SYSTEM WILL BRING THE NEXT CHANCE FOR SUB-VFR
CONDITIONS WEDNESDAY NIGHT INTO THURSDAY. IMPROVING AVIATION
CONDITIONS ANTICIPATED THURSDAY NIGHT INTO FRIDAY AS HIGH PRESSURE
BUILDS INTO THE REGION FROM THE NORTHWEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS/SMITH
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...WSS/SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
140 PM EDT MON APR 22 2013
.SYNOPSIS...
AN AREA OF HIGH PRESSURE WILL EXTEND ACROSS THE PIEDMONT TODAY
THROUGH TUESDAY. MEANWHILE A LOW PRESSURE SYSTEM WILL DEVELOP OFF
THE SOUTHEAST COAST TODAY...THEN TRACK NORTHEAST JUST OFF THE EAST
COAST TONIGHT THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 AM MONDAY...
A COLD NORTHEASTERLY BREEZE CONTINUES THIS MORNING BETWEEN A STRONG
HIGH PRESSURE RIDGE OVER THE PIEDMONT AND AN AMPLIFYING COASTAL
TROUGH. STRATUS OVER THE COASTAL AREAS IS BEGINNING TO PUSH INLAND
AND 1000-2000 FT CEILINGS ARE SHOWING UP IN A FEW OBSERVATIONS EAST
OF I-95. THIS TREND WILL CONTINUE THROUGHOUT THE DAY AS ANOTHER
SHALLOW UPPER LEVEL DISTURBANCE CROSSES THE AREA THIS AFTERNOON AND
CAUSES WEAK CYCLOGENESIS EAST OF WILMINGTON THIS EVENING. 12Z RAOB
ANALYSIS SHOWS AN EASTERLY 850MB WIND AT KMHX AND KWAL...WHICH THE
LARGER SCALE MODELS WERE FORECASTING TO BE NORTH-NORTHEASTERLY AT
THIS TIME. STRONGER WARM ADVECTION AT 850MB MAY LEAD TO A MORE
AGGRESSIVE INLAND PUSH OF LOW CLOUDS...BUT MOISTURE IS VERY SHALLOW
AND THE RAP MODEL KEEPS MEASURABLE PRECIP MOSTLY EAST OF THE CWA.
THERMAL ADVECTION BELOW 850MB APPEARS TO NEARLY NEUTRAL...BUT
STRENGTHENING NORTHEASTERLY FLOW THIS AFTERNOON WILL STILL KEEP
HIGHS 10-15 DEGREES NORMAL. THUS...THE ONLY CHANGES THIS MORNING
WILL BE TO ADJUST SKY COVER TRENDS AND LOWER HIGHS A COUPLE DEGREES
OVER THE COASTAL PLAIN. HIGHS IN THE MID 50S EAST TO LOWER 60S
WEST. -SMITH
TONIGHT...LOW CLOUDS WILL LINGER AS THE SFC WAVE LIFTS NEWD JUST OFF
THE NC COAST. LOW LEVEL WINDS WILL BECOME MORE NLY VERSUS NELY BY
DAYBREAK. OVERCAST SKIES AND STEADY SFC WINDS WILL MAINTAIN TEMPS IN
THE LOW-MID 40S OVERNIGHT. IF CLOUD DECK THINS/DISSIPATE IN THE
WEST...COULD SEE A FEW SPOTS COOL INTO THE UPPER 30S.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 305 AM MONDAY...
TUESDAY...SFC WAVE OFF THE NC COAST EARLY TUESDAY MORNING WILL LIFT
QUICKLY NWD AS MID LEVEL TROUGH EXITS OFFSHORE. SUBSIDENCE BEHIND
THE DEPARTING SYSTEM AND ADVECTION OF DRIER AIR WILL AID TO
DISSIPATE THE LOW CLOUDS ACROSS THE REGION FROM WEST-TO-EAST.
INCREASING SUN WILL AID TO WARM TEMPS BACK INTO THE 60S TO NEAR 70
IN THE AFTERNOON WITH THE COOLER TEMPS IN THE FAR NORTHERN COASTAL
PLAIN WHICH WILL LIKELY HOLD ONTO SOME DECENT CLOUD COVERAGE UNTIL
MID AFTERNOON.
TUESDAY NIGHT...WEAK HIGH PRESSURE WILL EXTEND ACROSS THE REGION AT
THE SURFACE WHILE S/W RIDGE ALOFT SCOOTS EWD. BACKING W-SW FLOW
BEHIND THE DEPARTING MID LEVEL RIDGE WILL ADVECT MID-HIGH LEVEL
MOISTURE INTO CENTRAL NC. THIS WILL LEAD TO AN INCREASE IN HIGH
CLOUDS BY EARLY WEDNESDAY MORNING. RESIDUAL LOW LEVEL MOISTURE WILL
LIKELY CAUSE PATCHES OF FOG OR LOW CLOUDS TO DEVELOP. HOWEVER IF
HIGH CLOUDS ARRIVE SOONER OR THICKER THAN EXPECTED...THIS WILL DETER
DEVELOPMENT OF SIGNIFICANT FOG/LOW CLOUDS. MIN TEMPS TUESDAY NIGHT
3-6 DEGREES WARMER THAN TONIGHT WITH MIN TEMPS MID-UPPER 40S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 305 AM MONDAY...
WEDNESDAY THROUGH THURSDAY NIGHT:
THE NEXT SYSTEM WILL QUICKLY MOVE INTO THE AREA LATE WEDNESDAY INTO
WEDNESDAY NIGHT... LINGERING INTO THURSDAY. HOWEVER... WITH A
SOUTHERLY RETURN FLOW DEVELOPING ON WEDNESDAY MORNING... THERE WILL
BE LITTLE TIME FOR LOW LEVEL MOISTURE RECOVERY. GIVEN THE BEST
DYNAMICS WITH THE SYSTEM ARE EXPECTED TO PASS TO THE NORTH OF THE
REGION... WITH GENERALLY WEST TO WEST-SOUTHWESTERLY MID LEVEL
FLOW... OVERALL MOISTURE TRANSPORT DOES NOT LOOK OVERLY IMPRESSIVE
WITH THIS SYSTEM. THUS... CHANCES FOR ANY SVR STORMS LOOKS TO VERY
LOW. INSTEAD EXPECT A BAND OF SHOWERS AND MAYBE A FEW STORMS TO MOVE
INTO NORTHERN PORTIONS OF THE AREA ON WEDNESDAY... WITH A DECENT MID
LEVEL CAP GENERALLY HOLDING FOR THE DAYLIGHT HOURS ON WEDNESDAY.
EXPECT THE COLD FRONT SHOULD BEGIN SLOWLY SINKING
SOUTH-SOUTHEASTWARD THROUGH THE AREA OVERNIGHT WEDNESDAY/THURSDAY
MORNING... WITH THE FRONT EXPECTED TO BE LOCATED ACROSS OUR
SOUTHERN/SOUTHEASTERN COUNTIES BY 12Z THURSDAY BEFORE EVENTUALLY
PUSHING SOUTH OF THE AREA SOMETIME LATE THURSDAY MORNING/AFTERNOON.
A BULK OF THE SHOWERS MAY BE MORE ANAFRONTAL AND ASSOCIATED MORE
WITH THE 925-850 MB FRONT AND SECONDARY S/W TROUGH EXPECTED TO CROSS
THE AREA ON THURSDAY. FOR NOW WILL SHOW LIKELY POPS FROM AROUND
MIDNIGHT THURSDAY ACROSS THE NORTHWESTERN HALF OF THE AREA UNTIL
AROUND NOON FOR THE SOUTHEASTERN/EASTERN HALF OF THE CWA... WITH
SHOWERS POSSIBLY LINGERING INTO THE AFTERNOON ACROSS OUR EASTERN AND
SOUTHEASTERN COUNTIES. BEHIND THE EXITING S/W THURSDAY AFTERNOON
EXPECT DRIER AIR TO ADVECT INTO THE AREA AT THE SURFACE AND ALOFT.
WAA AHEAD OF THE FRONT SHOULD LEAD TO AFTERNOON LOW LEVEL THICKNESS
VALUES SOARING INTO THE 1380S... POSSIBLY 1390S ON WEDNESDAY
AFTERNOON. EVEN WITH THE INCREASING CLOUD COVER EXPECT HIGH TEMPS
SHOULD BE IN THE MID TO UPPER 70S... WITH A FEW LOCATIONS ACROSS THE
SOUTH AND EAST TOUGHING 80 DEGREES. GIVEN THE POSSIBLE ANAFRONTAL
PRECIP BY EARLY THURSDAY MORNING AND DURING THE DAY ON THURSDAY...
LOW AND HIGH TEMPS WILL BE VERY TRICKY AND DEPENDENT ON THE TIMING
OF THE FRONT...QPF... AND HOW MUCH OF A SURGE OF DRY AIR AT THE
SURFACE MAKES IT INTO THE AREA BEHIND THE FRONT WHILE PRECIP IS
STILL EXPECTED. WRT THE TIMING OF THE FRONT THE 00Z NAM AND GFS ARE
PRETTY CONSISTENT SHOWING THE FRONT ACROSS OUR FAR
SOUTHERN/SOUTHEASTERN COUNTIES BY 12Z THURSDAY... WITH THE 12Z ECMWF
A BIT FARTHER TO THE NORTH (BUT NOT MUCH... MAYBE A ROW OF COUNTIES
FURTHER NORTH). WILL USE A BEND OF THE 12Z ECMWF AND 00Z GFS.
THUS... WILL GO WITH LOW TEMPS BY THURSDAY MORNING RANDING FROM
AROUND 50 NORTH TO THE LOWER 60S FAR SOUTH. HIGH TEMPS WILL BE QUITE
TRICKY FOR THURSDAY AFTERNOON AND BE DRIVEN LARGELY BY THE QPF AND
IF WE SEE ANY CLEARING ACROSS THE WEST IN THE AFTERNOON. WILL GO ON
THE COOL SIDE OF THE GUIDANCE... ESPECIALLY ACROSS THE
EASTERN/NORTHEASTERN PORTION OF THE CWA WHERE SHOWERS AND CLOUD
COVER WILL LIKELY LINGER THE LONGEST. THIS YIELDS HIGH RANGING FROM
NEAR 60 NE TO AROUND 70 ACROSS THE FAR SOUTH (VERY LOW CONFIDENCE
TEMP FORECAST). WITH SURFACE HIGH PRESSURE BUILDING INTO THE AREA ON
THURSDAY NIGHT/FRIDAY MORNING EXPECT CLEARING SKIES... WITH MUCH
COOLER TEMPS EXPECTED BY FRIDAY MORNING. EXPECT LOW TEMPS FRIDAY
MORNING WILL BE GENERALLY IN THE 40S... WITH MAYBE EVEN A FEW OF THE
USUAL COLD SPOTS ACROSS THE NORTH PIEDMONT DROPPING TO AROUND 40
DEGREES.
FRIDAY THROUGH SUNDAY:
VERY BRIEF S/W RIDGING WILL BUILD ACROSS THE AREA FRIDAY/FRIDAY
EVENING... BEFORE THE NEXT DISTURBANCE APPROACHES THE AREA FROM THE
SW IN GENERAL BROAD CYCLONIC FLOW ACROSS THE CONUS. MEDIUM RANGE
MODELS ARE STRUGGLING WITH THE STRENGTH AND PROGRESSION OF THIS S/W
TROUGH. WILL FOLLOW CLOSE TO WPC FOR NOW AND HEDGE TOWARDS THE
SLOWER SIDE OF GUIDANCE. THIS SCENARIO GENERALLY KEEPS THE AREA DRY
FOR SATURDAY... WITH SHOWERS/RAIN EXPECTED SATURDAY NIGHT INTO
SUNDAY... WITH POSSIBLY SOME FORM OF DAMMING AIRMASS. TEMPS DURING
THIS PERIOD ARE EXPECTED TO RUN SLIGHTLY BELOW NORMAL TO POSSIBLY
WELL BELOW NORMAL IN THE HEART OF THE DAMMING REGION WITH PRECIP
SPREADING INTO THE AREA AND THE SURFACE RIDGE AXIS EXTENDING BACK
INTO OUR AREA FROM THE NORTHEAST ON SUNDAY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 140 PM MONDAY...
DESPITE QUITE A BIT OF LOW LEVEL MOISTURE ALONG THE NC COAST AND A
STEADY 10-15KT NORTHEASTERLY WIND...LOW CLOUDS HAVE STRUGGLED TO
MOVE INLAND PAST THE I-95 CORRIDOR TODAY. KRWI AND KFAY HAVE
REPORTED PERIODS OF MVFR CEILINGS...TYPICALLY LASTING NO LONGER THAN
THAN AN HOUR OR TWO. BECAUSE OF THIS...CONFIDENCE IS BELOW AVERAGE
REGARDING WHEN LOW CLOUDS WILL SPREAD WEST TO KRDU AND EVENTUALLY
KGSO/KINT TONIGHT. EXPECT CEILINGS WILL REDEVELOP AT KRWI AND KFAY
BY THIS EVENING AS A LOW PRESSURE DEVELOPS OFFSHORE AND MOVES ALONG
THE COAST...LOWERING BELOW 2000FT AROUND MIDNIGHT AND REMAINING
THERE UNTIL LATE TUESDAY MORNING. FURTHER WEST...MVFR CEILINGS WILL
BE A LITTLE HIGHER AT KRDU BUT SHOULD STILL FALL BELOW 2000 FT BY
09Z. AT KGSO/KINT...CEILINGS MAY HOLD AT 2500 FT AND SCATTER OUT BY
MID MORNING AS THE SURFACE LOW MOVES NORTHEAST AWAY FROM THE AREA.
SURFACE WINDS WILL REMAIN UP OVERNIGHT...RANGING FROM 6-8KT IN THE
WEST TO AS HIGH AS 12-14KT IN THE EAST.
OUTLOOK...
AN APPROACHING FRONTAL SYSTEM WILL BRING THE NEXT CHANCE FOR SUB-VFR
CONDITIONS WEDNESDAY NIGHT INTO THURSDAY. IMPROVING AVIATION
CONDITIONS ANTICIPATED THURSDAY NIGHT INTO FRIDAY AS HIGH PRESSURE
BUILDS INTO THE REGION FROM THE NORTHWEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS/SMITH
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...WSS/SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
950 AM EDT MON APR 22 2013
.SYNOPSIS...
AN AREA OF HIGH PRESSURE WILL EXTEND ACROSS THE PIEDMONT TODAY
THROUGH TUESDAY. MEANWHILE A LOW PRESSURE SYSTEM WILL DEVELOP OFF
THE SOUTHEAST COAST TODAY...THEN TRACK NORTHEAST JUST OFF THE EAST
COAST TONIGHT THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 AM MONDAY...
A COLD NORTHEASTERLY BREEZE CONTINUES THIS MORNING BETWEEN A STRONG
HIGH PRESSURE RIDGE OVER THE PIEDMONT AND AN AMPLIFYING COASTAL
TROUGH. STRATUS OVER THE COASTAL AREAS IS BEGINNING TO PUSH INLAND
AND 1000-2000 FT CEILINGS ARE SHOWING UP IN A FEW OBSERVATIONS EAST
OF I-95. THIS TREND WILL CONTINUE THROUGHOUT THE DAY AS ANOTHER
SHALLOW UPPER LEVEL DISTURBANCE CROSSES THE AREA THIS AFTERNOON AND
CAUSES WEAK CYCLOGENESIS EAST OF WILMINGTON THIS EVENING. 12Z RAOB
ANALYSIS SHOWS AN EASTERLY 850MB WIND AT KMHX AND KWAL...WHICH THE
LARGER SCALE MODELS WERE FORECASTING TO BE NORTH-NORTHEASTERLY AT
THIS TIME. STRONGER WARM ADVECTION AT 850MB MAY LEAD TO A MORE
AGGRESSIVE INLAND PUSH OF LOW CLOUDS...BUT MOISTURE IS VERY SHALLOW
AND THE RAP MODEL KEEPS MEASURABLE PRECIP MOSTLY EAST OF THE CWA.
THERMAL ADVECTION BELOW 850MB APPEARS TO NEARLY NEUTRAL...BUT
STRENGTHENING NORTHEASTERLY FLOW THIS AFTERNOON WILL STILL KEEP
HIGHS 10-15 DEGREES NORMAL. THUS...THE ONLY CHANGES THIS MORNING
WILL BE TO ADJUST SKY COVER TRENDS AND LOWER HIGHS A COUPLE DEGREES
OVER THE COASTAL PLAIN. HIGHS IN THE MID 50S EAST TO LOWER 60S
WEST. -SMITH
TONIGHT...LOW CLOUDS WILL LINGER AS THE SFC WAVE LIFTS NEWD JUST OFF
THE NC COAST. LOW LEVEL WINDS WILL BECOME MORE NLY VERSUS NELY BY
DAYBREAK. OVERCAST SKIES AND STEADY SFC WINDS WILL MAINTAIN TEMPS IN
THE LOW-MID 40S OVERNIGHT. IF CLOUD DECK THINS/DISSIPATE IN THE
WEST...COULD SEE A FEW SPOTS COOL INTO THE UPPER 30S.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 305 AM MONDAY...
TUESDAY...SFC WAVE OFF THE NC COAST EARLY TUESDAY MORNING WILL LIFT
QUICKLY NWD AS MID LEVEL TROUGH EXITS OFFSHORE. SUBSIDENCE BEHIND
THE DEPARTING SYSTEM AND ADVECTION OF DRIER AIR WILL AID TO
DISSIPATE THE LOW CLOUDS ACROSS THE REGION FROM WEST-TO-EAST.
INCREASING SUN WILL AID TO WARM TEMPS BACK INTO THE 60S TO NEAR 70
IN THE AFTERNOON WITH THE COOLER TEMPS IN THE FAR NORTHERN COASTAL
PLAIN WHICH WILL LIKELY HOLD ONTO SOME DECENT CLOUD COVERAGE UNTIL
MID AFTERNOON.
TUESDAY NIGHT...WEAK HIGH PRESSURE WILL EXTEND ACROSS THE REGION AT
THE SURFACE WHILE S/W RIDGE ALOFT SCOOTS EWD. BACKING W-SW FLOW
BEHIND THE DEPARTING MID LEVEL RIDGE WILL ADVECT MID-HIGH LEVEL
MOISTURE INTO CENTRAL NC. THIS WILL LEAD TO AN INCREASE IN HIGH
CLOUDS BY EARLY WEDNESDAY MORNING. RESIDUAL LOW LEVEL MOISTURE WILL
LIKELY CAUSE PATCHES OF FOG OR LOW CLOUDS TO DEVELOP. HOWEVER IF
HIGH CLOUDS ARRIVE SOONER OR THICKER THAN EXPECTED...THIS WILL DETER
DEVELOPMENT OF SIGNIFICANT FOG/LOW CLOUDS. MIN TEMPS TUESDAY NIGHT
3-6 DEGREES WARMER THAN TONIGHT WITH MIN TEMPS MID-UPPER 40S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 305 AM MONDAY...
WEDNESDAY THROUGH THURSDAY NIGHT:
THE NEXT SYSTEM WILL QUICKLY MOVE INTO THE AREA LATE WEDNESDAY INTO
WEDNESDAY NIGHT... LINGERING INTO THURSDAY. HOWEVER... WITH A
SOUTHERLY RETURN FLOW DEVELOPING ON WEDNESDAY MORNING... THERE WILL
BE LITTLE TIME FOR LOW LEVEL MOISTURE RECOVERY. GIVEN THE BEST
DYNAMICS WITH THE SYSTEM ARE EXPECTED TO PASS TO THE NORTH OF THE
REGION... WITH GENERALLY WEST TO WEST-SOUTHWESTERLY MID LEVEL
FLOW... OVERALL MOISTURE TRANSPORT DOES NOT LOOK OVERLY IMPRESSIVE
WITH THIS SYSTEM. THUS... CHANCES FOR ANY SVR STORMS LOOKS TO VERY
LOW. INSTEAD EXPECT A BAND OF SHOWERS AND MAYBE A FEW STORMS TO MOVE
INTO NORTHERN PORTIONS OF THE AREA ON WEDNESDAY... WITH A DECENT MID
LEVEL CAP GENERALLY HOLDING FOR THE DAYLIGHT HOURS ON WEDNESDAY.
EXPECT THE COLD FRONT SHOULD BEGIN SLOWLY SINKING
SOUTH-SOUTHEASTWARD THROUGH THE AREA OVERNIGHT WEDNESDAY/THURSDAY
MORNING... WITH THE FRONT EXPECTED TO BE LOCATED ACROSS OUR
SOUTHERN/SOUTHEASTERN COUNTIES BY 12Z THURSDAY BEFORE EVENTUALLY
PUSHING SOUTH OF THE AREA SOMETIME LATE THURSDAY MORNING/AFTERNOON.
A BULK OF THE SHOWERS MAY BE MORE ANAFRONTAL AND ASSOCIATED MORE
WITH THE 925-850 MB FRONT AND SECONDARY S/W TROUGH EXPECTED TO CROSS
THE AREA ON THURSDAY. FOR NOW WILL SHOW LIKELY POPS FROM AROUND
MIDNIGHT THURSDAY ACROSS THE NORTHWESTERN HALF OF THE AREA UNTIL
AROUND NOON FOR THE SOUTHEASTERN/EASTERN HALF OF THE CWA... WITH
SHOWERS POSSIBLY LINGERING INTO THE AFTERNOON ACROSS OUR EASTERN AND
SOUTHEASTERN COUNTIES. BEHIND THE EXITING S/W THURSDAY AFTERNOON
EXPECT DRIER AIR TO ADVECT INTO THE AREA AT THE SURFACE AND ALOFT.
WAA AHEAD OF THE FRONT SHOULD LEAD TO AFTERNOON LOW LEVEL THICKNESS
VALUES SOARING INTO THE 1380S... POSSIBLY 1390S ON WEDNESDAY
AFTERNOON. EVEN WITH THE INCREASING CLOUD COVER EXPECT HIGH TEMPS
SHOULD BE IN THE MID TO UPPER 70S... WITH A FEW LOCATIONS ACROSS THE
SOUTH AND EAST TOUGHING 80 DEGREES. GIVEN THE POSSIBLE ANAFRONTAL
PRECIP BY EARLY THURSDAY MORNING AND DURING THE DAY ON THURSDAY...
LOW AND HIGH TEMPS WILL BE VERY TRICKY AND DEPENDENT ON THE TIMING
OF THE FRONT...QPF... AND HOW MUCH OF A SURGE OF DRY AIR AT THE
SURFACE MAKES IT INTO THE AREA BEHIND THE FRONT WHILE PRECIP IS
STILL EXPECTED. WRT THE TIMING OF THE FRONT THE 00Z NAM AND GFS ARE
PRETTY CONSISTENT SHOWING THE FRONT ACROSS OUR FAR
SOUTHERN/SOUTHEASTERN COUNTIES BY 12Z THURSDAY... WITH THE 12Z ECMWF
A BIT FARTHER TO THE NORTH (BUT NOT MUCH... MAYBE A ROW OF COUNTIES
FURTHER NORTH). WILL USE A BEND OF THE 12Z ECMWF AND 00Z GFS.
THUS... WILL GO WITH LOW TEMPS BY THURSDAY MORNING RANDING FROM
AROUND 50 NORTH TO THE LOWER 60S FAR SOUTH. HIGH TEMPS WILL BE QUITE
TRICKY FOR THURSDAY AFTERNOON AND BE DRIVEN LARGELY BY THE QPF AND
IF WE SEE ANY CLEARING ACROSS THE WEST IN THE AFTERNOON. WILL GO ON
THE COOL SIDE OF THE GUIDANCE... ESPECIALLY ACROSS THE
EASTERN/NORTHEASTERN PORTION OF THE CWA WHERE SHOWERS AND CLOUD
COVER WILL LIKELY LINGER THE LONGEST. THIS YIELDS HIGH RANGING FROM
NEAR 60 NE TO AROUND 70 ACROSS THE FAR SOUTH (VERY LOW CONFIDENCE
TEMP FORECAST). WITH SURFACE HIGH PRESSURE BUILDING INTO THE AREA ON
THURSDAY NIGHT/FRIDAY MORNING EXPECT CLEARING SKIES... WITH MUCH
COOLER TEMPS EXPECTED BY FRIDAY MORNING. EXPECT LOW TEMPS FRIDAY
MORNING WILL BE GENERALLY IN THE 40S... WITH MAYBE EVEN A FEW OF THE
USUAL COLD SPOTS ACROSS THE NORTH PIEDMONT DROPPING TO AROUND 40
DEGREES.
FRIDAY THROUGH SUNDAY:
VERY BRIEF S/W RIDGING WILL BUILD ACROSS THE AREA FRIDAY/FRIDAY
EVENING... BEFORE THE NEXT DISTURBANCE APPROACHES THE AREA FROM THE
SW IN GENERAL BROAD CYCLONIC FLOW ACROSS THE CONUS. MEDIUM RANGE
MODELS ARE STRUGGLING WITH THE STRENGTH AND PROGRESSION OF THIS S/W
TROUGH. WILL FOLLOW CLOSE TO WPC FOR NOW AND HEDGE TOWARDS THE
SLOWER SIDE OF GUIDANCE. THIS SCENARIO GENERALLY KEEPS THE AREA DRY
FOR SATURDAY... WITH SHOWERS/RAIN EXPECTED SATURDAY NIGHT INTO
SUNDAY... WITH POSSIBLY SOME FORM OF DAMMING AIRMASS. TEMPS DURING
THIS PERIOD ARE EXPECTED TO RUN SLIGHTLY BELOW NORMAL TO POSSIBLY
WELL BELOW NORMAL IN THE HEART OF THE DAMMING REGION WITH PRECIP
SPREADING INTO THE AREA AND THE SURFACE RIDGE AXIS EXTENDING BACK
INTO OUR AREA FROM THE NORTHEAST ON SUNDAY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 730 AM MONDAY...
VFR CONDITIONS AT 7 AM WILL GRADUALLY DETERIORATE FROM THE EAST
LATER THIS MORNING AS A STRENGTHENING LOW LEVEL NE FETCH OFF THE
ATLANTIC ADVECTS MOISTURE IN THE FORM OF A STRATUS INTO EASTERN AND
CENTRAL NC. THIS MVFR CEILING SHOULD REACH THE KRWI VICINITY BY
10-11 AM...AND THE KRDU AND KFAY TERMINAL SITES BY MID-DAY OR EARLY
AFTERNOON. THE MOISTURE APPEARS TO BE SHALLOW...SO NOT EXPECTING
MUCH IF ANY PRECIP ASIDE FROM SPOTS OF DRIZZLE OR LIGHT RAIN...MOST
LIKELY (BUT STILL LESS THAN A 30 PERCENT CHANCE) AT KRWI.
DUE TO THE DIFFERENCE IN PRESSURE BETWEEN A SURFACE RIDGE OVER THE
PIEDMONT AND A DEVELOPING LOW PRESSURE SYSTEM OFF THE SE U.S.
COAST...NE WINDS WILL STRENGTHEN THIS MORNING WITH SUSTAINED SPEEDS
CLOSE TO 15KTS AND GUSTS NEAR 25KTS...ESPECIALLY AT KFAY AND KRWI.
TONIGHT...THE STRATUS WILL REACH THE TRIAD TERMINALS SHORTLY BEFORE
SUNSET...RESULTING IN MVFR CEILINGS ACROSS A LARGE PORTION OF
CENTRAL NC OVERNIGHT. NE WINDS 10-15KTS WILL SLOWLY BACK TO A MORE
N-NE DIRECTION AS THE SURFACE LOW LIFTS NE ALONG THE NC COAST.
THE LOW WILL CONTINUE TO LIFT NE AWAY FROM NC TUESDAY MORNING. AS
THE LOW PULLS AWAY...SURFACE WINDS WILL BACK TO A MORE NW
DIRECTION...ADVECTING DRIER AIR INTO THE REGION. THIS WILL LEAD TO A
DISSIPATION OF THE STRATUS DECK AND IMPROVING AVIATION CONDITIONS.
VFR CONDITIONS SHOULD PREVAIL MOST TAF SITES BY MID DAY TUESDAY.
AN APPROACHING FRONTAL SYSTEM WILL BRING THE NEXT CHANCE FOR SUB-VFR
CONDITIONS WEDNESDAY NIGHT INTO THURSDAY. IMPROVING AVIATION
CONDITIONS ANTICIPATED THURSDAY NIGHT INTO FRIDAY AS HIGH PRESSURE
BUILDS INTO THE REGION FROM THE NORTHWEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS/SMITH
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1014 PM CDT TUE APR 23 2013
.UPDATE...
ISSUED AT 1013 PM CDT TUE APR 23 2013
MAIN CHANGE WAS TO SLOW DOWN THE PROGRESSION OF PRECIP INTO THE
AREA TONIGHT AND TOMORROW...AS THE RAP AND NAM ARE BACKING OFF ON
PRECIP AND ONLY A TINY AMOUNT IS FALLING IN THE WEST SO FAR. THINK
THAT PRECIP WILL BE MOSTLY AFTER SUNRISE TOMORROW AND ANYTHING
SHOULD BE PRETTY LIGHT.
UPDATE ISSUED AT 701 PM CDT TUE APR 23 2013
LOWERED CLOUD COVER A BIT THIS EVENING AS IT SEEMS MOST OF THE
BEST COVERAGE WILL HOLD OFF UNTIL AFTER MIDNIGHT AS THE SHORTWAVE
IN CANADA APPROACHES. NO OTHER CHANGES.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 344 PM CDT TUE APR 23 2013
SEEMS LIKE THE MOST CUMULUS DEVELOPMENT TODAY WAS JUST TO THE EAST
OF THE RED RIVER VALLEY. OTHERWISE THERE ARE SOME HIGH LEVEL CLOUDS
STREAMING INTO THE WESTERN FA. GENERALLY EXPECT CLOUDS TO INCREASE
TONIGHT BUT IT MAY TAKE LONGER FOR THEM TO REACH THE EAST AND
SOUTHEAST FA. THE NEXT UPSTREAM WAVE IS CURRENTLY OVER NORTHEAST
ALBERTA AND IS FORECAST TO DROP INTO THE FA LATE TONIGHT. WENT AHEAD
AND INCREASED PCPN CHANCES INTO THE LIKELY RANGE IN THE NORTHWEST FA
TOWARD WED MORNING. LOOKS LIKE THIS WILL BE A HIGH POP/LOW QPF EVENT
OVERALL.
THE SFC REFLECTION OF THE ABOVE MENTIONED WAVE WILL BE A COLD FRONT
THAT DROPS INTO THE NORTHWEST FA BY WED MORNING. AS THIS FEATURE
DROPS THRU THE FA DURING THE DAY EXPECT THE BEST CHANCES FOR PCPN TO
BE ACROSS THE NORTH AND NORTHEAST. HOWEVER THERE SHOULD BE SOME
LIGHT SNOW JUST ABOUT EVERYWHERE. AS IN THE PAST FEW EVENTS IT
SHOULD MELT ON THE ROADS AND JUST STAY WET DURING THE DAYTIME HOURS
WITH THE ONLY ACCUMULATION IN GRASSY/SNOW COVERED AREAS. WPC
SNOWFALL GRAPHIC SHOWING THE POSSIBILITY FOR AN INCH OR SO OF SNOW
ALONG AND NORTH OF THE HIGHWAY 2 CORRIDOR AND THAT SEEMS REASONABLE.
SREF PCPN TYPE SEEMS PRETTY WELL PEGGED ON JUST SNOW AND WILL GO
WITH THAT IDEA TOO. THINK SOME AFTERNOON TEMPS MAY GET INTO THE
MID 30S BUT THAT WOULD BE ABOUT IT.
BY WED NIGHT THE SYSTEM SHOULD BE PULLING OFF TO THE EAST. LEFT SOME
VERY LOW CHANCES FOR LIGHT SNOW IN THE FAR EAST EARLY. LOWS WILL
PROBABLY DEPEND ON HOW FAST OR IF THE CLOUDS CLEAR OUT. THERE IS
SOME PRETTY STRONG WARM ADVECTION THAT KICKS IN ESPECIALLY ACROSS
THE WEST WHICH MAY LEAD TO INCREASING CLOUDS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 344 PM CDT TUE APR 23 2013
THU-FRI...SOUTH WINDS ON THU WITH THE GOOD WARM ADVECTION SHIFTING
OVER THE FA. LOOKING LIKE 850MB TEMPS SHOULD RISE BACK ABOVE ZERO
BY 00Z FRI. THE WARMER WEATHER CONTINUES TO LOOK ON TRACK INTO FRI
AS WELL. DEGREE OF WARMING MAY DEPEND ON HOW MUCH SFC WIND OCCURS
WITH MODELS SHOWING FAIRLY WEAK WINDS ON FRI.
FRIDAY NIGHT-TUESDAY...ECMWF AND GFS ARE IN GOOD AGREEMENT DEPICTING
ZONAL TO SOUTHWEST FLOW ALOFT INTO SUNDAY...BUT THEN BECOME OUT OF
PHASE FOR MONDAY AND TUESDAY. FOR MONDAY INTO TUESDAY...THE ECMWF IS
MORE AMPLIFIED WITH THE WEST COAST TROUGH/EAST COAST RIDGE COMPARED
TO THE GFS. THE ECMWF SOLUTION WOULD KEEP A SURFACE BOUNDARY ACROSS
THE FA ALONG WITH A MORE PROLONGED PERIOD OF SHOWER AND/OR
THUNDERSTORM CHANCES. THE GFS SOLUTION WOULD LEAD TO ONLY A BRIEF
PERIOD OF SHOWERS AND/OR THUNDERSTORMS (LIKELY ON MONDAY) WITH HIGH
PRESSURE MOVING INTO THE REGION BY MID-WEEK. THESE ARE OBVIOUSLY BIG
DIFFERENCES AND IMPORTANT GIVEN THE STATE OF RIVER FLOODING. GIVEN
THE LOW CONFIDENCE IN ANY ONE PARTICULAR SOLUTION...WILL GO WITH LOW
END RAIN CHANCES. TEMPERATURES WILL BE THE OTHER BIG CHALLENGE. A
MUCH WARMER AIRMASS WILL HAVE BEEN ADVECTED INTO THE REGION AND
EXPECT MORE NEAR NORMAL TEMPERATURES. SNOWPACK WILL DETERMINE HOW
WARM...AND THINK MOST AREAS SHOULD HAVE ENOUGH SNOW MELTED TO
REALIZE WARMER VALUES. THE EXCEPTION WILL BE THE DEVILS LAKE BASIN
WHERE THE SNOW NORMALLY TAKES LONGER TO MELT...AND KEPT MAX TEMPS IN
THE 40S. WILL NOT WORRY ABOUT FOG...BUT THAT COULD AFFECT
TEMPERATURES AS WELL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 701 PM CDT TUE APR 23 2013
VFR CONDITIONS WILL CONTINUE FOR THE FIRST HALF OF THE TAF PERIOD.
A SYSTEM DIGGING DOWN FROM CANADA WILL BRING SOME MVFR CIGS AND
-SN TO THE REGION TOMORROW MORNING INTO EARLY AFTERNOON. THINK
THAT SNOW WILL BE LIGHT AND VIS SHOULD BE 2-5SM MOSTLY BUT WILL
HAVE TO WATCH FOR ANY REDUCTIONS TO 1SM OR LOWER. WINDS WILL SHIFT
TO THE NORTHWEST AND BECOME GUSTY TO THE 20 TO 25 KTS RANGE BY TOMORROW
AFTERNOON AS A COLD FRONT MOVES INTO THE AREA.
&&
.HYDROLOGY...
ISSUED AT 1254 PM CDT TUE APR 23 2013
RIVER FLOOD WARNINGS CONTINUE FOR THE RED RIVER AT WAHPETON/HICKSON/
FARGO...THE SOUTH BRANCH BUFFALO RIVER AT SABIN AND THE BUFFALO
RIVER AT DILWORTH. OVERALL...THE RATE AT WHICH THESE RIVERS ARE
EXPECTED TO RISE THROUGH FRIDAY WAS LOWERED DUE TO COLD TEMPERATURES
LIMITING THE MELT AND THE FORECAST CREST AT WAHPETON WAS LOWERED
HALF A FOOT TO 16.5 FT TO ACCOUNT FOR LESS AVAILABLE OBSERVED RUNOFF
SOUTH OF HWY 210 ACROSS WEST CENTRAL MN.
LOCALIZED SNOWMELT RUNOFF WILL RESULT IN GRADUAL RISES ALONG THE RED
RIVER AT WAHPETON...HICKSON AND FARGO FOR MUCH OF THIS WEEK.
ADDITIONAL RISES ARE ALSO EXPECTED ALONG THE SOUTH BRANCH BUFFALO
RIVER AT SABIN AND THE BUFFALO RIVER AT DILWORTH. VERY COOL LATE
APRIL TEMPERATURES WILL CONTINUE THROUGH THURSDAY WITH DAYTIME HIGHS
IN THE 30S AND LOWER 40S AND NIGHTTIME LOWS IN THE UPPER TEENS AND
20S. THESE TEMPERATURES WILL LIMIT THE DEGREE OF SNOWMELT THROUGH
MUCH OF THE WEEK.
FRIDAY INTO THE WEEKEND...TEMPERATURES ARE EXPECTED TO RISE
SIGNIFICANTLY...WITH HIGHS IN THE LOWER 60S POSSIBLE THIS WEEKEND.
MORNING LOWS ARE ALSO EXPECTED TO RISE ABOVE FREEZING...RESULTING IN
SIGNIFICANT SNOWMELT RUNOFF AND MORE RAPID RISES IN RIVER LEVELS.
WITH NO SIGNIFICANT PRECIPITATION EXPECTED THE NEXT SEVERAL
DAYS...RIVER RISES WILL DEPEND HEAVILY ON THE TEMPERATURE PATTERN
AND RESULTANT SNOWMELT. IN ADDITION...A LATE PROLONGED SNOWMELT HAS
ALLOWED SOME OF THE EARLIER MELT WATER TO INFILTRATE THE SOIL. EXACT
AMOUNTS ARE UNCERTAIN AT THIS TIME AND THIS UNCERTAINTY IS REFLECTED
IN A RANGE OF CRESTS FOR THE RED RIVER AT WAHPETON. THUS...FORECAST
RIVER LEVELS FOR THIS WEEKEND ARE SUBJECT TO FURTHER REVISIONS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...GODON
LONG TERM...TG
AVIATION...JR
HYDROLOGY...ROGERS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
944 AM CDT MON APR 22 2013
.UPDATE...
ISSUED AT 945 AM CDT MON APR 22 2013
THE MAIN CHALLENGE WILL BE SNOW CHANCES IN THE FAR SOUTHERN
FORECAST AREA. THE 12Z NAM IS BRUSHING THE FAR SOUTH WITH PERHAPS
AN INCH OF SNOW...AND WILL INCREASE POPS HERE FROM 15-21Z IN THE
EXTREME SOUTHERN AREAS...WITH SOUTHERN GRANT COUNTY SEEING THE
BEST POTENTIAL FOR AN INCH OR PERHAPS 2. OTHERWISE...THE FORECAST
IS IN GOOD SHAPE WITH NO MAJOR CHANGES PLANNED.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 330 AM CDT MON APR 22 2013
FORECAST CHALLENGES CONCERN SNOW CHANCES ACROSS THE FAR SOUTH
TODAY AND TEMPERATURES. MODELS OVERALL IN GOOD AGREEMENT THROUGH
THE SHORT TERM AND WILL USE BLEND.
FOR TODAY FAR SOUTHERN FA WILL BE IN ENTRANCE REGION OF PASSING UPPER
JET MAXIMA. MAIN BAROCLINIC ZONE WELL SOUTH OF FA HOWEVER LOWER
CONDENSATION PRESSURE DEFICITS CLIP FAR SOUTHERN FA. MODELS HAVE
INITIALIZED PRETTY WELL WITH W SD SNOW BAND. NORTHERN EXTENT
SOMEWHAT IN QUESTION WITH RADAR COVERAGE HOWEVER HETTINGER AT THIS
POINT DRY SO SNOW SHOULD BE RIGHT ALONG OR JUST SOUTH OF BORDER.
BASED ON GOOD MODEL AGREEMENT FAR SOUTH WILL BE ON NORTHERN FRINGE
OF PCPN. WILL FOLLOW HIGH RESOLUTION RAP MODEL SOLUTION AND
INCREASE POPS ALONG ND/SD/MN BORDER AREA TODAY. STEADY COLD
ADVECTION AND SOME DEGREE OF CLOUD COVER WILL REALLY LIMIT ANY
TEMPERATURE RECOVERY. DVL BASIN MAY STRUGGLE TO GET TO
FREEZING/MELTING VALUES.
HIGH PRESSURE WILL BUILD INTO CENTRAL/NORTHERN PLAINS TONIGHT.
WITH LIGHT WINDS/MINIMAL CLOUD COVER AND COLD COLUMN WILL RESULT
IN COLD TEMPERATURES WITH RECORD LOWS POSSIBLE.
COLUMN WARMS SLIGHTLY TUESDAY AND ALONG WITH SOLAR AND MODEST
WESTERLY FLOW TEMPERATURES SHOULD BE A BIT WARMER.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 AM CDT MON APR 22 2013
MODEST TEMPERATURE RECOVERY WILL CONTINUE INTO MIDWEEK HOWEVER
WITH TEMPERATURES DROPPING BLO FREEZING AT NIGHT SNOW MELT PROCESS
WILL CONTINUE TO BE SLOW. NEXT WAVE TO SWING THROUGH BROAD CENTRAL
PLAINS MID LEVEL TROUGH WEDNESDAY HOWEVER LOOKS TO BE A LIGHT PCPN
EVENT.
THURSDAY TO SUNDAY...CONFIDENT IN A GENERALLY DRY PERIOD WITH
TEMPERATURES MODERATING TOWARD NEAR NORMAL BY NEXT WEEKEND. NW FLOW
ALOFT WITH SFC RIDGE AXIS IS EXPECTED TO DEPART THE REGION THURSDAY
WITH MORE ZONAL 500MB FLOW AND SOUTHERN RETURN FLOW ALLOWING FOR
850MB TEMPS TO WARM FROM 5 TO 10 BLO C THURS MORNING TO 5 TO 10
ABOVE BY FRI MORNING. WEAK SW AND FROPA WILL BRING SCHC OF SHRA FRI
AFTN. ANOTHER PERIOD OF WAA IS EXPECTED TO LIFT INTO THE REGION
SATURDAY AND SUNDAY WITH WEAK 500MB RIDGING WITH 850MB TEMPS PUSHING
INTO THE 10 TO 15 C RANGE.
HOW THESE TEMPS WILL INTERACT WITH SNOWPACK...ESPECIALLY IN THE
DEEPER SNOWS OF THE DEVILS LAKE BASIN AND NORTHERN RED RIVER
VALLEY...CAUSES SOME UNCERTAINTY IN THE OVERALL EXTENT OF THE WARM
UP. IF MIXING IS LESS THAN EXPECTED FOG WOULD BE LIKELY TO DEVELOP
OVERNIGHT LIMITING SOLAR INFLUENCES THE NEXT DAY OF THE WARM UP.
NONETHELESS LIKELY THAT THE GRADUAL SNOW MELT ENDS WITH OVERNIGHT
TEMPS ABOVE FREEZING BEGINNING FRIDAY NIGHT AND THRU THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 945 AM CDT MON APR 22 2013
SEEING EXTENSIVE MID AND HIGH LEVEL CLOUDS ALONG AND SOUTH OF A LINE
FROM KBIS TO KGFK TO KBDE. OF MAIN CONCERN TO THE AVIATION FORECAST
ARE SOME LOWER BATCHES OF CLOUDS...ONE AROUND THE KDVL AREA AND
ANOTHER UP AROUND THE LAKE OF THE WOODS. BOTH THESE BATCHES OF
CLOUDS ARE IN THE MVFR RANGE. THE AREA AROUND KDVL APPEARS TO BE
SINKING SLOWLY SOUTHWARD AND WILL AFFECT KDVL AND POSSIBLY KGFK.
&&
.HYDROLOGY...
ISSUED AT 330 AM CDT MON APR 22 2013
RIVER FLOOD WARNINGS IN EFFECT FOR SABIN ALONG THE S BR BUFFALO
RIVER...DILWORTH ALONG THE BUFFALO RIVER...AND WAHPETON ALONG THE
RED RIVER. DESPITE THE RELATIVELY COOL TEMPS...LOCALIZED RUNOFF
ALONG SOME OF THE MN TRIBS...INCLUDING ALONG THE BUFFALO... HAS
LEAD TO INCREASED RIVER STAGES. SIMILARLY...GRADUAL RISES HAVE
BEEN NOTED ALONG THE MAINSTEM RED AS WATER BEGINS TO MAKE ITS WAY
INTO THE SYSTEM. THIS IS ESPECIALLY TRUE ACROSS THE SOUTH TOWARDS
WAHPETON...WHERE MINOR FLOOD STAGE WILL LIKELY BE APPROACHED BY
EARLY THIS WEEK. COOLER TEMPS THROUGH THE MIDDLE OF THE WEEK WILL
LIMIT THE SNOWMELT PROCESS WITH WELL BELOW FREEZING TEMPS AT
NIGHT. IT APPEARS MORE SIGNIFICANT WARMING WILL OCCUR BY LATE THIS
WEEK. THIS WILL LEAD TO INCREASED SNOWMELT RUNOFF...AND MORE RAPID
RIVER RESPONSES BY NEXT WEEKEND. SOME UNCERTAINTY EXISTS REGARDING
THE DEGREE AND TIMING OF THE WARMER TEMPS...WHICH WILL AFFECT HOW
QUICKLY THE RIVERS RESPOND. NO SIGNIFICANT PRECIP EVENTS ARE
EXPECTED AT THIS TIME THROUGH THE COMING WEEK.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...DK
SHORT TERM...VOELKER
LONG TERM...JK
AVIATION...GODON
HYDROLOGY...JK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
650 AM CDT MON APR 22 2013
.UPDATE...
ISSUED AT 645 AM CDT MON APR 22 2013
ONLY CHANGES THIS UPDATE WERE TO DELAY SLIGHTLY SNOW CHANCES
ACROSS FAR SOUTHERN FA IN THE NEAR TERM. ANY -SN HAS YET TO REACH
THIS PORTION OF THE FA. REMAINDER OF FORECAST LOOKS ON TRACK.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 330 AM CDT MON APR 22 2013
FORECAST CHALLENGES CONCERN SNOW CHANCES ACROSS THE FAR SOUTH
TODAY AND TEMPERATURES. MODELS OVERALL IN GOOD AGREEMENT THROUGH
THE SHORT TERM AND WILL USE BLEND.
FOR TODAY FAR SOUTHERN FA WILL BE IN ENTRANCE REGION OF PASSING UPPER
JET MAXIMA. MAIN BAROCLINIC ZONE WELL SOUTH OF FA HOWEVER LOWER
CONDENSATION PRESSURE DEFICITS CLIP FAR SOUTHERN FA. MODELS HAVE
INITIALIZED PRETTY WELL WITH W SD SNOW BAND. NORTHERN EXTENT
SOMEWHAT IN QUESTION WITH RADAR COVERAGE HOWEVER HETTINGER AT THIS
POINT DRY SO SNOW SHOULD BE RIGHT ALONG OR JUST SOUTH OF BORDER.
BASED ON GOOD MODEL AGREEMENT FAR SOUTH WILL BE ON NORTHERN FRINGE
OF PCPN. WILL FOLLOW HIGH RESOLUTION RAP MODEL SOLUTION AND
INCREASE POPS ALONG ND/SD/MN BORDER AREA TODAY. STEADY COLD
ADVECTION AND SOME DEGREE OF CLOUD COVER WILL REALLY LIMIT ANY
TEMPERATURE RECOVERY. DVL BASIN MAY STRUGGLE TO GET TO
FREEZING/MELTING VALUES.
HIGH PRESSURE WILL BUILD INTO CENTRAL/NORTHERN PLAINS TONIGHT.
WITH LIGHT WINDS/MINIMAL CLOUD COVER AND COLD COLUMN WILL RESULT
IN COLD TEMPERATURES WITH RECORD LOWS POSSIBLE.
COLUMN WARMS SLIGHTLY TUESDAY AND ALONG WITH SOLAR AND MODEST
WESTERLY FLOW TEMPERATURES SHOULD BE A BIT WARMER.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 AM CDT MON APR 22 2013
MODEST TEMPERATURE RECOVERY WILL CONTINUE INTO MIDWEEK HOWEVER
WITH TEMPERATURES DROPPING BLO FREEZING AT NIGHT SNOW MELT PROCESS
WILL CONTINUE TO BE SLOW. NEXT WAVE TO SWING THROUGH BROAD CENTRAL
PLAINS MID LEVEL TROUGH WEDNESDAY HOWEVER LOOKS TO BE A LIGHT PCPN
EVENT.
THURSDAY TO SUNDAY...CONFIDENT IN A GENERALLY DRY PERIOD WITH
TEMPERATURES MODERATING TOWARD NEAR NORMAL BY NEXT WEEKEND. NW FLOW
ALOFT WITH SFC RIDGE AXIS IS EXPECTED TO DEPART THE REGION THURSDAY
WITH MORE ZONAL 500MB FLOW AND SOUTHERN RETURN FLOW ALLOWING FOR
850MB TEMPS TO WARM FROM 5 TO 10 BLO C THURS MORNING TO 5 TO 10
ABOVE BY FRI MORNING. WEAK SW AND FROPA WILL BRING SCHC OF SHRA FRI
AFTN. ANOTHER PERIOD OF WAA IS EXPECTED TO LIFT INTO THE REGION
SATURDAY AND SUNDAY WITH WEAK 500MB RIDGING WITH 850MB TEMPS PUSHING
INTO THE 10 TO 15 C RANGE.
HOW THESE TEMPS WILL INTERACT WITH SNOWPACK...ESPECIALLY IN THE
DEEPER SNOWS OF THE DEVILS LAKE BASIN AND NORTHERN RED RIVER
VALLEY...CAUSES SOME UNCERTAINTY IN THE OVERALL EXTENT OF THE WARM
UP. IF MIXING IS LESS THAN EXPECTED FOG WOULD BE LIKELY TO DEVELOP
OVERNIGHT LIMITING SOLAR INFLUENCES THE NEXT DAY OF THE WARM UP.
NONETHELESS LIKELY THAT THE GRADUAL SNOW MELT ENDS WITH OVERNIGHT
TEMPS ABOVE FREEZING BEGINNING FRIDAY NIGHT AND THRU THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 645 AM CDT MON APR 22 2013
WILL SEE PRIMARILY VFR CONDITIONS ACROSS ALL TAF SITES TODAY.
COULD SEE A BRIEF MVFR PERIOD THIS MORNING ACROSS DVL BASIN WITH
MVFR CIGS JUST WEST OF THE FORECAST AREA. CONVECTIVE TEMPERATURES
ONLY AROUND 30 SO WILL LIKELY SEE SOME SC DEVELOPMENT HOWEVER CIGS
LOOK TO BE VFR.
&&
.HYDROLOGY...
ISSUED AT 330 AM CDT MON APR 22 2013
RIVER FLOOD WARNINGS IN EFFECT FOR SABIN ALONG THE S BR BUFFALO
RIVER...DILWORTH ALONG THE BUFFALO RIVER...AND WAHPETON ALONG THE
RED RIVER. DESPITE THE RELATIVELY COOL TEMPS...LOCALIZED RUNOFF
ALONG SOME OF THE MN TRIBS...INCLUDING ALONG THE BUFFALO... HAS
LEAD TO INCREASED RIVER STAGES. SIMILARLY...GRADUAL RISES HAVE
BEEN NOTED ALONG THE MAINSTEM RED AS WATER BEGINS TO MAKE ITS WAY
INTO THE SYSTEM. THIS IS ESPECIALLY TRUE ACROSS THE SOUTH TOWARDS
WAHPETON...WHERE MINOR FLOOD STAGE WILL LIKELY BE APPROACHED BY
EARLY THIS WEEK. COOLER TEMPS THROUGH THE MIDDLE OF THE WEEK WILL
LIMIT THE SNOWMELT PROCESS WITH WELL BELOW FREEZING TEMPS AT
NIGHT. IT APPEARS MORE SIGNIFICANT WARMING WILL OCCUR BY LATE THIS
WEEK. THIS WILL LEAD TO INCREASED SNOWMELT RUNOFF...AND MORE RAPID
RIVER RESPONSES BY NEXT WEEKEND. SOME UNCERTAINTY EXISTS REGARDING
THE DEGREE AND TIMING OF THE WARMER TEMPS...WHICH WILL AFFECT HOW
QUICKLY THE RIVERS RESPOND. NO SIGNIFICANT PRECIP EVENTS ARE
EXPECTED AT THIS TIME THROUGH THE COMING WEEK.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...VOELKER
SHORT TERM...VOELKER
LONG TERM...JK
AVIATION...VOELKER
HYDROLOGY...VOELKER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
334 AM CDT MON APR 22 2013
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 330 AM CDT MON APR 22 2013
FORECAST CHALLENGES CONCERN SNOW CHANCES ACROSS THE FAR SOUTH
TODAY AND TEMPERATURES. MODELS OVERALL IN GOOD AGREEMENT THROUGH
THE SHORT TERM AND WILL USE BLEND.
FOR TODAY FAR SOUTHERN FA WILL BE IN ENTRANCE REGION OF PASSING UPPER
JET MAXIMA. MAIN BAROCLINIC ZONE WELL SOUTH OF FA HOWEVER LOWER
CONDENSATION PRESSURE DEFICITS CLIP FAR SOUTHERN FA. MODELS HAVE
INITIALIZED PRETTY WELL WITH W SD SNOW BAND. NORTHERN EXTENT
SOMEWHAT IN QUESTION WITH RADAR COVERAGE HOWEVER HETTINGER AT THIS
POINT DRY SO SNOW SHOULD BE RIGHT ALONG OR JUST SOUTH OF BORDER.
BASED ON GOOD MODEL AGREEMENT FAR SOUTH WILL BE ON NORTHERN FRINGE
OF PCPN. WILL FOLLOW HIGH RESOLUTION RAP MODEL SOLUTION AND
INCREASE POPS ALONG ND/SD/MN BORDER AREA TODAY. STEADY COLD
ADVECTION AND SOME DEGREE OF CLOUD COVER WILL REALLY LIMIT ANY
TEMPERATURE RECOVERY. DVL BASIN MAY STRUGGLE TO GET TO
FREEZING/MELTING VALUES.
HIGH PRESSURE WILL BUILD INTO CENTRAL/NORTHERN PLAINS TONIGHT.
WITH LIGHT WINDS/MINIMAL CLOUD COVER AND COLD COLUMN WILL RESULT
IN COLD TEMPERATURES WITH RECORD LOWS POSSIBLE.
COLUMN WARMS SLIGHTLY TUESDAY AND ALONG WITH SOLAR AND MODEST
WESTERLY FLOW TEMPERATURES SHOULD BE A BIT WARMER.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 AM CDT MON APR 22 2013
MODEST TEMPERATURE RECOVERY WILL CONTINUE INTO MIDWEEK HOWEVER
WITH TEMPERATURES DROPPING BLO FREEZING AT NIGHT SNOW MELT PROCESS
WILL CONTINUE TO BE SLOW. NEXT WAVE TO SWING THROUGH BROAD CENTRAL
PLAINS MID LEVEL TROUGH WEDNESDAY HOWEVER LOOKS TO BE A LIGHT PCPN
EVENT.
THURSDAY TO SUNDAY...CONFIDENT IN A GENERALLY DRY PERIOD WITH
TEMPERATURES MODERATING TOWARD NEAR NORMAL BY NEXT WEEKEND. NW FLOW
ALOFT WITH SFC RIDGE AXIS IS EXPECTED TO DEPART THE REGION THURSDAY
WITH MORE ZONAL 500MB FLOW AND SOUTHERN RETURN FLOW ALLOWING FOR
850MB TEMPS TO WARM FROM 5 TO 10 BLO C THURS MORNING TO 5 TO 10
ABOVE BY FRI MORNING. WEAK SW AND FROPA WILL BRING SCHC OF SHRA FRI
AFTN. ANOTHER PERIOD OF WAA IS EXPECTED TO LIFT INTO THE REGION
SATURDAY AND SUNDAY WITH WEAK 500MB RIDGING WITH 850MB TEMPS PUSHING
INTO THE 10 TO 15 C RANGE.
HOW THESE TEMPS WILL INTERACT WITH SNOWPACK...ESPECIALLY IN THE
DEEPER SNOWS OF THE DEVILS LAKE BASIN AND NORTHERN RED RIVER
VALLEY...CAUSES SOME UNCERTAINTY IN THE OVERALL EXTENT OF THE WARM
UP. IF MIXING IS LESS THAN EXPECTED FOG WOULD BE LIKELY TO DEVELOP
OVERNIGHT LIMITING SOLAR INFLUENCES THE NEXT DAY OF THE WARM UP.
NONETHELESS LIKELY THAT THE GRADUAL SNOW MELT ENDS WITH OVERNIGHT
TEMPS ABOVE FREEZING BEGINNING FRIDAY NIGHT AND THRU THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1138 PM CDT SUN APR 21 2013
CENTRAL TAF SITES HAVE CLEARED OFF WITH ONLY SOME CIRRUS
REMAINING. KBJI REMAINS MVFR AND SOME STRATUS WITH 2500-3500 FT
CIGS HAS STARTED TO MOVE INTO THE KDVL REGION. THIS SHOULD SPREAD
SOUTH AND EAST OVERNIGHT...BUT COVERAGE IS BROKEN AND CLEAR SPOTS
WILL CONTINUE. INCLUDED SOME TEMPO GROUPS FOR VARIATION BETWEEN
VFR AND MVFR CONDITIONS WITH THE PARTIAL STRATUS COVERAGE. THERE
COULD BE SOME BREAK IN THE CIGS THIS MORNING BUT STRATOCU WILL
REDEVELOP AND BRING CIGS AROUND 3500-5000 FT FOR AFTERNOON. MORE
WIDESPREAD CLEARING LATE IN THE PERIOD.
&&
.HYDROLOGY...
ISSUED AT 330 AM CDT MON APR 22 2013
RIVER FLOOD WARNINGS IN EFFECT FOR SABIN ALONG THE S BR BUFFALO
RIVER...DILWORTH ALONG THE BUFFALO RIVER...AND WAHPETON ALONG THE
RED RIVER. DESPITE THE RELATIVELY COOL TEMPS...LOCALIZED RUNOFF
ALONG SOME OF THE MN TRIBS...INCLUDING ALONG THE BUFFALO... HAS
LEAD TO INCREASED RIVER STAGES. SIMILARLY...GRADUAL RISES HAVE
BEEN NOTED ALONG THE MAINSTEM RED AS WATER BEGINS TO MAKE ITS WAY
INTO THE SYSTEM. THIS IS ESPECIALLY TRUE ACROSS THE SOUTH TOWARDS
WAHPETON...WHERE MINOR FLOOD STAGE WILL LIKELY BE APPROACHED BY
EARLY THIS WEEK. COOLER TEMPS THROUGH THE MIDDLE OF THE WEEK WILL
LIMIT THE SNOWMELT PROCESS WITH WELL BELOW FREEZING TEMPS AT
NIGHT. IT APPEARS MORE SIGNIFICANT WARMING WILL OCCUR BY LATE THIS
WEEK. THIS WILL LEAD TO INCREASED SNOWMELT RUNOFF...AND MORE RAPID
RIVER RESPONSES BY NEXT WEEKEND. SOME UNCERTAINTY EXISTS REGARDING
THE DEGREE AND TIMING OF THE WARMER TEMPS...WHICH WILL AFFECT HOW
QUICKLY THE RIVERS RESPOND. NO SIGNIFICANT PRECIP EVENTS ARE
EXPECTED AT THIS TIME THROUGH THE COMING WEEK.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...VOELKER
LONG TERM...JK
AVIATION...JR
HYDROLOGY...VOELKER
AREA FORECAST DISCUSSION
NWS TULSA OK
1221 PM CDT MON APR 22 2013
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
ELEVATED SHOWERS EARLY THIS AFTERNOON MAY AFFECT KBVO.
ADDITIONAL THUNDERSTORMS ARE EXPECTED TO AFFECT AREA
TAF SITES THIS EVENING AND INTO TUESDAY MORNING AS A COLD
FRONT MOVES THROUGH THE AREA. MVFR CEILINGS WILL DEVELOP
BEHIND THE COLD FRONT.
&&
.PREV DISCUSSION... /ISSUED 1048 AM CDT MON APR 22 2013/
DISCUSSION...
ELEVATED SHOWERS HAVE DEVELOPED ACROSS NORTH-CENTRAL OKLAHOMA AND
INTO OSAGE AND PAWNEE COUNTIES IN NORTHEAST OKLAHOMA. THIS ACTIVITY
WILL MOVE OFF TO THE NORTHEAST THROUGH THE REMAINDER OF THE MORNING
AND EARLY AFTERNOON. LOCAL MODELS AND THE LATEST HRRR KEEP SURFACE
BASED CONVECTION ALONG THE FRONT WHICH IS CURRENTLY ADVANCING INTO
NORTHERN KANSAS. THIS ACTIVITY LOOKS TO AFFECT NORTHEAST OKLAHOMA
AFTER 00Z.
TEMPERATURES LOOKS TO BE REASONABLE AND HAVE ONLY MADE SIGNIFICANT
ADJUSTMENTS TO THE SKY...POP AND WX GRIDS FOR TODAY.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...10
AREA FORECAST DISCUSSION
NWS TULSA OK
1048 AM CDT MON APR 22 2013
.DISCUSSION...
ELEVATED SHOWERS HAVE DEVELOPED ACROSS NORTH-CENTRAL OKLAHOMA AND
INTO OSAGE AND PAWNEE COUNTIES IN NORTHEAST OKLAHOMA. THIS ACTIVITY
WILL MOVE OFF TO THE NORTHEAST THROUGH THE REMAINDER OF THE MORNING
AND EARLY AFTERNOON. LOCAL MODELS AND THE LATEST HRRR KEEP SURFACE
BASED CONVECTION ALONG THE FRONT WHICH IS CURRENTLY ADVANCING INTO
NORTHERN KANSAS. THIS ACTIVITY LOOKS TO AFFECT NORTHEAST OKLAHOMA
AFTER 00Z.
TEMPERATURES LOOKS TO BE REASONABLE AND HAVE ONLY MADE SIGNIFICANT
ADJUSTMENTS TO THE SKY...POP AND WX GRIDS FOR TODAY.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...10
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
630 PM CDT TUE APR 23 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 254 PM CDT TUE APR 23 2013
CLEAR SKIES ARE EXPECTED TO CONTINUE THROUGH THE EVENING HOURS
TONIGHT AS SURFACE HIGH PRESSURE BUILDS INTO THE AREA. WINDS ON THE
SURFACE WILL TURN WEST TO SOUTHWEST OVERNIGHT...THOUGH THE PRESSURE
GRADIENT DOESN`T BECOME ALL THAT LIGHT. AS SUCH...HAVE NUDGED
FORECAST LOWS UPWARD EVER SO SLIGHTLY...WITH WARMEST READINGS IN
MOST EXPOSED LOCATIONS. NAM FORECAST SOUNDINGS INDICATE POTENTIAL
FOR FOG...BUT THIS IS NOT SUPPORTED BY THE RAP SOUNDINGS. HRRR IS
DOWN FOR MAINTENANCE...BUT IN GENERAL...THINK THE WINDS WILL STAY UP
ENOUGH TONIGHT THAT FOG WILL NOT BE THAT BIG OF A CONCERN.
SHORTWAVE DROPS SOUTHEAST ACROSS THE REGION ON WEDNESDAY. MODELS
SUGGEST THAT SOME OF THE INITIAL DYNAMICS WILL BE LOST TO SATURATING
THE NEAR SURFACE LAYER. TOUGH CALL ON PRECIPITATION TYPE WHICH WILL
BE CONTROLLED BY SURFACE TEMPERATURES AS THIS IS THE ONLY LOCATION
IN THE THERMO PROFILE THAT IS POTENTIALLY ABOVE FREEZING. HAVE A
MIX OF SNOW AND RAIN ALONG THE HIGHWAY 14 CORRIDOR IN THE LAT
MORNING INTO THE EARLY AFTERNOON...BUT IN GENERAL PRECIPITATION
SHOULD PRIMARILY FAVOR RAIN WHICH IS SUPPORTED BY SREF PROFILES.
PROFILES ARE WEAKLY UNSTABLE ALOFT...AND GIVEN THIS IS THE
CASE...THE POTENTIAL EXISTS FOR RAIN OR SNOW SHOWERS TO DEVELOP IN
THE AFTERNOON HOURS. IF THE INTENSITY WAS TO GET STRONG
ENOUGH...THEN MAY BE ABLE TO GET BRIEF SNOW SQUALLS IN HIGHER
INTENSITY PRECIPITATION BANDS. IN GENERAL...EXPECT PRECIPITATION
AMOUNTS TO BE FAIRLY LIGHT...WITH A FEW HUNDREDTHS OF AN INCH OR
LESS IN MOST LOCATIONS. APPEARS TO BE QUITE BREEZY WITH 20-30 KNOTS
OF FLOW AT 925 HPA COMBINED WITH LOW LEFT COLD AIR ADVECTION AIDING
IN MIXING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 254 PM CDT TUE APR 23 2013
THE TAIL END OF THE WAVE WILL BE MOVING THROUGH EARLY ON WEDNESDAY
EVENING MAY ALLOW FOR A FEW STRAGGLING SHOWERS IN THE FAR EASTERN
CWA...OTHERWISE CLEARING SKIES AND LIGHTER WINDS SHOULD ALLOW FOR
A COOL NIGHT AS NORTHWEST WINDS RELAX TO WEST AND SOUTHWEST. LOWS
SHOULD MAINLY BE IN THE 20S WITH A FEW TEENS POSSIBLE AREAS WITH
DEEPER SNOW COVER.
THURSDAY WILL PROVE TO BE A DECENT SNOW MELTING DAY WITH MOSTLY
SUNNY TO PARTLY CLOUD CONDITIONS AND MILDER READINGS. LOW LEVEL
WIND DIRECTION AND THE LOCATION OF THE INCOMING WARM FRONT WILL
PLAY A BIG ROLE ON WHERE THE BEST WARMING WILL BE. WILL AIM FOR
THE WARMEST READINGS WEST OF THE JAMES RIVER VALLEY WHERE THE BEST
CHANCE RESIDES OF WINDS BECOMING SOUTH OR SLIGHTLY SOUTHWEST. THE
FARTHER EAST FROM HERE THE BETTER CHANCE THAT A SOUTHEAST
COMPONENT WILL HANG IN. WILL HAVE HIGHS RANGING FROM 60 TO 65 WEST
OF THE JAMES TO AROUND 50 NORTH AND EAST OF A BROOKINGS TO JACKSON
LINE.
THURSDAY NIGHT INTO FRIDAY WILL SEE A SOUTHERLY WIND TURNS A BIT
SOUTHWEST WHICH WILL BRING THE PROBABILITY FOR MUCH WARMER
READINGS AND LIKELY THE FINAL DAY WITH ANY REAL SNOW COVER LEFT ON
THE GROUND. NOT PLANNING ON THE SNOW COVER HAVING MUCH OF AN
EFFECT SO WILL GO WITH HIGHS MAINLY IN THE 60S.
THE BIG WARM UP IS STILL ON TAP THIS WEEKEND AND WILL CONTINUE TO
KEEP ABOVE NORMAL TEMPERATURES GOING. THE MAIN DIFFERENCES IN THE
MODELS SHOW UP AROUND MONDAY WHERE THE GFS DIVES COLDER AIR SOUTH
AS A FAIRLY STRONG TROUGH MOVES THROUGH NORTH DAKOTA. THE ECMWF
AND THE EXTRAPOLATED GEM ARE LESS BOISTEROUS WITH THIS WAVE AND
MORE OR LESS RIDE THE ENERGY ALONG AND NORTH OF THE PERIPHERY OF
THE RIDGE...KEEPING THE WARM AIR IN PLACE THROUGH TUESDAY. WILL
STICK CLOSEST TO THE GEM/ECMWF OUTPUT WHICH SEEMS MORE REASONABLE
AND THE GFS IS LIKELY PUSHING THE TROUGH TO AGGRESSIVELY THROUGH
THE EXISTING RIDGE. NOT PLANNING ON ANY REAL ISSUES WITH
PRECIPITATION DURING THIS TIME FRAME.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 611 PM CDT TUE APR 23 2013
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD .MODEL SOUNDINGS
SUGGEST THE POTENTIAL FOR FOG...HOWEVER WITH ONLY LIMITED SNOW MELT
WILL LEAVE OUT ANY MENTION FOR TONIGHT. PRECIPITATION IS EXPECTED TO
DEVELOP AROUND KHON AROUND 18Z...SPREADING SOUTHEAST THROUGH THE
AFTERNOON.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...
LONG TERM...08
AVIATION...
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
341 PM CDT MON APR 22 2013
.SHORT TERM...
A STRONG COLD FRONT LOOKING TO BE A LITTLE AHEAD OF SCHEDULE HAVING
ALREADY NOSED INTO THE OKLAHOMA PANHANDLE AS OF 19Z...ALTHOUGH THE
COLD AIR LAGGING THE INITIAL WIND SHIFT BY ABOUT 150 TO 200 MILES.
MORNING RAP RUNS FASTEST WITH THE FRONT LOOK TO BE THE MODEL TO LEAN
TOWARD...AND POSSIBLY SLIGHTLY FASTER THAN THAT. WINDS WILL LIKELY
ACCELERATE TOWARD ADVISORY CRITERIA WITH PRESSURE RISES BEHIND IT...
ALTHOUGH FOR NOW WILL KEEP SPEEDS JUST BELOW THAT LEVEL. WILL RUN
WITH LOW TEMPS JUST BELOW LOW END OF MOS NUMBERS GIVEN STRENGTH OF
THE COLD AIR. THAT WOULD PUT POTENTIAL FOR A LIGHT FREEZE ACROSS THE
EXTREME SW PANHANDLE WHERE JUST NOW REACHING AVG DATE TO THE
BEGINNING OF THE GROWING SEASON. BETTER CANDIDATE FOR FREEZE PRODUCT
TO COME TUESDAY NIGHT WITH POTENTIAL FOR A HARD FREEZE. LOW CLOUDS
TO FILTER IN BEHIND THE FRONT. WHILE LOW CLOUDS PROGGED TO LIFT
TUESDAY MORNING...PERSISTENT MID LEVEL MOISTURE SHOULD KEEP SOME
CLOUD COVER OVER THE AREA. THAT COMBINED WITH LOW LEVEL COLD
ADVECTION THROUGH THE DAY WILL RESULT IN A DIURNAL RANGE OF 10 TO 15
DEGREES. OTHER ISSUE IS CHANCE FOR LIGHT PRECIP IN POST-FRONTAL AIR
MASS LATE TONIGHT AND EARLY TUESDAY. LOW LEVEL FRONTOGENESIS MAY BE
SUFFICIENT TO GENERATE SOME DRIZZLE OR VERY LIGHT RAIN ACROSS THE
NERN ZONES...BUT MEASURABLE PRECIP CHANCES LOOK VERY SLIM WITH BEST
LIFT ASSOCIATED WITH MID LEVEL TROUGH/JET REMAINING NORTH OF THE
FCST AREA. FINALLY...WHILE COLD FRONT WILL BE MOVING INTO AIR WITH
DEW POINTS IN THE 40S AND THUS SOME CAPE...CAP STRENGTH LOOKS TO BE
VERY STRONG WITH LITTLE POTENTIAL THAT ENERGY CAN BE RELEASED.
&&
.LONG TERM...
THE PRIMARY CONCERN FOR TUESDAY NIGHT AND WEDNESDAY MORNING WILL BE
THE POTENTIAL FOR A WIDESPREAD FREEZE ON THE HEELS OF THE PREVIOUS
NIGHTS FROPA. MODELS SEEM TO AGREE THAT H850 TEMPS WILL SETTLE
SOMEWHERE BETWEEN 0 TO -3 DEGREES... WITH THE NAM BEING THE COLD
OUTLIER OF THE BUNCH. IN ADDITION... A 1025-1030MB SURFACE RIDGE
WILL SLIDE JUST TO THE NE OF THE AREA OVERNIGHT...WHICH WILL KEEP
WINDS VERY LIGHT. ON THE OTHER HAND... SOME LINGERING JET ENERGY
AND MID-LEVEL MOISTURE COULD KEEP A BIT OF CLOUD COVER IN THE
AREA... INHIBITING RADIATIONAL COOLING IN SOME SPOTS... PARTICULARLY
IN THE EASTERN ZONES. REGARDLESS... CLOUD COVER SHOULD BREAK UP
BEFORE SUNRISE... AND TEMPERATURES ACROSS THE CAPROCK WILL LIKELY
FALL TO AROUND 4-8 DEGREES BELOW FREEZING BEFORE ALL IS SAID AND
DONE. TEMPERATURES WILL GRADUALLY RISE WEDNESDAY AND THURSDAY AHEAD
OF AN APPROACHING WAVE... WHICH WILL BE OUR NEXT ITEM OF CONCERN.
BY THURSDAY... A MEANDERING CLOSED LOW WILL WORK ITS WAY EASTWARD
FROM THE SUBTROPICAL PACIFIC BEFORE OPENING UP AND PHASING WITH A
BROAD CENTRAL CONUS TROUGH. BEFORE COMPLETELY BEING ABSORBED...
THIS WAVE WILL TRAVERSE THE TX PANHANDLE SOMETIME LATE THURSDAY
NIGHT... ALTHOUGH THERE IS STILL ABOUT 6 HOURS OF DISAGREEMENT
BETWEEN THE THE GFS AND ECMWF. AHEAD OF THIS WAVE... PRESSURE FALLS
ACROSS THE SOUTHERN FRONT RANGE WILL BEGIN TO FORCE SOUTHERLY FLOW
ACROSS TX...AND IN TURN ALLOW MODEST MOISTURE TO RETURN TO THE SOUTH
PLAINS AND EASTERN NM. DUE TO TUESDAYS COLD FRONT PINNING DEEP
MOISTURE WELL TO THE SOUTH... THE TIMING AND EXTENT OF THIS MOISTURE
RETURN IS IN QUESTION... AND AT THIS TIME IT APPEARS THAT THE BEST
MOISTURE WILL STRUGGLE TO ARRIVE UNTIL OVERNIGHT THURSDAY AND EVEN
EARLY FRIDAY MORNING. IN ADDITION... A STOUT CAP AND LOW-LEVEL
STRATUS WILL LIKELY ELIMINATE THE POSSIBILITY FOR AFTERNOON
THUNDERSTORM INITIATION EXCEPT FOR POSSIBLY ALONG THE
DRYLINE/PACIFIC FRONT IN EASTERN NM. AS THE WAVE PROGRESSES
EASTWARD... A PACIFIC FRONT WILL ALSO PUSH EASTWARD AND LIKELY
TRAVERSE THE AREA VERY LATE THURSDAY/EARLY FRIDAY...ALTHOUGH AGAIN
THE TIMING OF THIS FEATURE IS STILL SOMEWHAT IN QUESTION. AS THIS
FRONT MOVES EAST... IMPROVING MOISTURE ACROSS THE SOUTH PLAINS COULD
YIELD AT MARGINAL CHANCES FOR SHOWER/THUNDERSTORM
DEVELOPMENT...MOSTLY ACROSS THE NORTHERN ZONES WITH THE ADDED
FORCING FROM THE FRONT AND PASSING WAVE.
BEYOND FRIDAY MORNING... MODEL SOLUTIONS DIVERGE SIGNIFICANTLY...
ALTHOUGH THE GENERAL TREND WILL BE FOR BUILDING HEIGHTS AND WARMER
TEMPERATURES THROUGH THE END OF THE WEEK AND INTO THE
WEEKEND....FOLLOWING A BENIGN COLD FRONT FRIDAY NIGHT/SATURDAY
MORNING. MODELS ARE NOT IN AGREEMENT REGARDING THE ADVANCEMENT OF
THIS FRONT... AS THE ECMWF SENDS IT WELL SOUTH INTO THE TRANS PECOS
REGION WHILE THE GFS STALLS IT HALFWAY THROUGH THE LBB CWA. GIVEN
THE WEAKENING STATE OF THE PASSING WAVE AND LACK OF SIGNIFICANT COLD
ADVECTION... GFS SEEMS MORE REASONABLE HERE... ALTHOUGH CONVECTIVE
SIGNAL IN GFS FOR SUNDAY AFTERNOON SEEMS SUSPECT GIVEN THE ANEMIC
UPPER FLOW AND LACK OF FORCING. BOTH MODELS SEEM TO HINT AT A
SLOW-APPROACHING TROUGH/CLOSED LOW SOMETIME EARLY NEXT WEEK... BUT
AT THIS POINT SOLUTIONS ARE TOO FAR APART AND TOO FAR AWAY TO PUT
MUCH STOCK IN.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 30 45 25 59 36 / 10 10 10 0 10
TULIA 31 46 26 60 38 / 10 10 10 0 10
PLAINVIEW 32 48 27 60 38 / 10 10 10 0 10
LEVELLAND 35 50 28 60 38 / 10 10 10 0 10
LUBBOCK 35 50 30 60 39 / 10 10 10 0 10
DENVER CITY 39 54 26 61 33 / 10 10 10 0 10
BROWNFIELD 38 51 28 61 35 / 10 10 10 0 10
CHILDRESS 36 48 33 62 40 / 10 10 10 0 10
SPUR 39 49 32 61 44 / 10 10 10 0 10
ASPERMONT 43 50 33 62 43 / 10 10 10 0 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07/16
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
108 PM CDT MON APR 22 2013
.AVIATION...
FOR THE 18Z TAFS...THE TIMING OF AN UNSEASONABLY STRONG COLD FRONT
THROUGH AREA AIRPORTS IS THE PRIMARY CONCERN.
LATEST MODEL GUIDANCE INDICATES THAT THE FRONT WILL MOVE THROUGH
THE DFW AREA IN THE 14 TO 16Z TIMEFRAME. HAVE 14Z FOR THE WESTERN
TAFS AND 15Z FOR THE EASTERN SITES. WE WILL BE ABLE TO REFINE THE
TIMING OF THE FRONT ONCE IT GETS CLOSER TO NORTH TX AND WE CAN
TRACK ITS SOUTHWARD MOVEMENT. EXPECT AREAS OF LIGHT RAIN OR
DRIZZLE TO PERSIST ALONG AND BEHIND THE FRONTAL BOUNDARY TOMORROW.
BETWEEN THE VERY LIGHT PRECIPITATION AND THE LOW-LEVEL COLD AIR
ADVECTION BEHIND THE FRONT...EXPECT CLOUDS TO REMAIN AT LOW MVFR
LEVELS THRU MUCH OF THE DAY WHICH IS ABNORMAL FOR LATE APRIL. CIGS
MAY CLIMB BRIEFLY ABOVE 2 KFT IN THE LATE AFTERNOON HRS...BUT WILL
LIKELY FALL BACK BELOW 2 KFT TUESDAY EVENING.
OTHERWISE...EXPECT THAT MVFR STRATUS WILL BUILD OVER AREA AIRPORTS
AFTER MIDNIGHT TONIGHT AS SLIGHTLY DEEPER GULF MOISTURE WORKS OVER
THE REGION DUE TO PERSISTENT SOUTHERLY FLOW TONIGHT. DESPITE SOME
BETTER GULF MOISTURE MOVING IN OUT AHEAD OF THE COLD
FRONT...THUNDERSTORM AND SIGNIFICANT PRECIPITATION CHANCES WILL
REMAIN STRONGLY CAPPED BY WARM AIR ALOFT.
CAVANAUGH
&&
.UPDATE...
WITH LESS CLOUDS THIS MORNING THAN PREVIOUSLY FORECASTED...HAVE
BUMPED UP HIGHS A COUPLE OF DEGREES ACROSS MOST OF THE AREA. DID
NOT GO QUITE AS HIGH AS WHAT THE RAP WAS FORECASTING /MID-80S/.
OTHERWISE...MADE MINOR CHANGES TO THE OTHER HOURLY GRIDS TO
ACCOUNT FOR CHANGES.
HAMPSHIRE
&&
.PREV DISCUSSION... /ISSUED 353 AM CDT MON APR 22 2013/
TODAY WILL BE BREEZY AND WARMER WITH PLENTY OF SUNSHINE BUT
CHANGES ARE ON THE WAY TOMORROW AS AN UNSEASONABLY STRONG COLD
FRONT MOVES THROUGH. WE CONTINUE TO FAVOR THE SLIGHTLY FASTER
FRONTAL TIMING OF NAM/WRF MODELS...WHICH SUGGEST THE FRONT WILL
REACH THE DFW METROPLEX AROUND 9-10 AM TUESDAY...WACO AROUND
NOON...AND PUSH OUT OF THE SE ZONES BY 4 PM. HIGH TEMPS TUESDAY
WILL OCCUR AHEAD OF THE FRONT...AND WILL BE VERY SENSITIVE TO
EXACT FRONTAL TIMING. TEMPS BEHIND THE FRONT WILL PLUNGE 15-25
DEGREES...AND EXPECT THE NW HALF OF THE CWA TO BE IN THE UPPER 40S
BY MID-LATE AFTERNOON TUESDAY WITH A BRISK NORTHERLY WIND MAKING
IT FEEL EVEN COLDER. THE AIRMASS ACROSS NORTH TEXAS WILL BE CAPPED
BY A STRONG TEMPERATURE INVERSION NEAR 750MB...AND THEREFORE DEEP
CONVECTION ALONG THE FRONT APPEARS UNLIKELY. HOWEVER...THE FRONT
WILL PLOW INTO A SATURATED COLUMN BENEATH THIS INVERSION...AND
RAPID MECHANICAL LIFTING WILL LIKELY SQUEEZE OUT A THIN LINE OF
SHOWERS ALONG THE FRONTAL BOUNDARY. WOULD EXPECT MOST LOCATIONS TO
SEE BRIEF LIGHT RAIN TOMORROW...BUT THE CHANCE OF MEASURABLE
RAINFALL IS LOW AND THEREFORE WILL KEEP POPS AT 20 PERCENT.
OTHERWISE SOME AREAS OF DRIZZLE MAY DEVELOP OVER NORTH TEXAS
BEHIND THE FRONT IN THE AFTERNOON HOURS.
COLD AIR ADVECTION WILL CONTINUE INTO TUESDAY NIGHT AND EXPECT
TEMPS TO FALL INTO THE MID-UPPER 30S ACROSS THE NORTHERN ZONES TO
MID-UPPER 40S IN THE SOUTH FOR LOWS. SOUTHWEST FLOW ALOFT WILL
PREVAIL IN THE WAKE OF THE FRONT WHICH WILL SET UP AN OVERRUNNING
TYPE PATTERN. A SHORTWAVE TROUGH WILL MOVE THROUGH CENTRAL/EAST
TEXAS TUESDAY NIGHT. ELEVATED MOISTURE/INSTABILITY ARE SUFFICIENT
FOR WIDELY SCATTERED ELEVATED SHOWERS AND A FEW STORMS WITH BEST
CHANCES OVER THE SOUTHEAST HALF OF THE AREA WITH THIS WAVE TUESDAY
NIGHT. MODEL GUIDANCE IS STRUGGLING WITH TRYING TO TIME A SECOND
SUBSEQUENT SHORTWAVE. THE ECMWF IS POINTING AT WEDNESDAY NIGHT AND
THE GFS SEEMS TO HINT AT THIS AS WELL BUT SHOWS LITTLE QPF. THE
NAM/CANADIAN ARE EARLIER AND MORE FOCUSED ON WEDNESDAY. WILL BRUSH
SOME LOW POPS INTO WEDNESDAY BUT HOLD OFF ON BRINGING THEM INTO
WEDNESDAY NIGHT UNTIL WE GET MORE MODEL CONSISTENCY. THERE MAY BE
ENOUGH INSTABILITY FOR ELEVATED THUNDERSTORMS WITH THIS SECOND
SHORTWAVE BUT HAVE KEPT IT WORDED AS JUST SHOWERS FOR NOW. TEMPS
WEDNESDAY WILL BE IMPACTED SIGNIFICANTLY BY ANY POST-FRONTAL
CLOUDS/RAIN. WITH NORTH WINDS PREVAILING INTO WEDNESDAY AND CLOUDS
LIKELY TO PERSIST ACROSS AT LEAST THE SOUTHERN ZONES...HAVE
UNDERCUT GUIDANCE AND PUT HIGHS ONLY IN THE 50S THERE. THE
NORTHERN ZONES HAVE A BETTER CHANCE AT SEEING SOME LATE APRIL SUN
AND THEREFORE HAVE FORECAST WARMER TEMPS IN THE LOW 60S THERE.
COLD ADVECTION SHOULD WANE WEDNESDAY NIGHT AS WINDS TURN TO THE
EAST BUT CLOUDS SHOULD KEEP TEMPS FROM FALLING AS COOL AS GUIDANCE
SUGGESTS. BY THURSDAY...WINDS WILL TURN AROUND TO THE SOUTH BUT
STILL THINK THAT CLOUDS WILL BE PREVALENT AND TEMPER THE WARM UP.
HAVE UNDERCUT HIGHS FOR THURSDAY AND JUST WENT MID-UPPER 60S.
THE NEXT UPPER LEVEL SYSTEM IS A CLOSED LOW IN THE SUBTROPICAL
PACIFIC THAT WILL MELD WITH AN UPPER TROUGH OVER THE CONTINENT AND
MOVE ACROSS THE SOUTHERN PLAINS FRIDAY AND SATURDAY. STILL NOT
GETTING GREAT AGREEMENT IN THE MODELS WITH THIS FEATURE AND THE
ECMWF REMAINS THE STRONGEST/SLOWEST WITH IT. THE CANADIAN/UKMET
ARE PRETTY WEAK WITH THE FEATURE AND SUGGEST LIMITED QPF. THE GFS
SEEMS TO OFFER A COMPROMISE. WILL KEEP THE LOW POPS SPREAD ACROSS
THE AREA FRIDAY AND END THEM FROM WEST TO EAST SATURDAY. THE
AIRMASS ACROSS NORTH TEXAS WILL REMAIN FAIRLY COOL AND NOT HAVE
MUCH TIME TO RECHARGE OR DESTABILIZE AHEAD OF THIS SYSTEM...AND
THEREFORE WE MAY BE TOO STABLE OR CAPPED FOR A SIGNIFICANT
CONVECTIVE EVENT. THE CAP WOULD BE THE WEAKEST ACROSS THE
NORTHERN ZONES NEARER TO THE BETTER UPPER FORCING AND THEREFORE
HAVE BUMPED UP POPS TO 30 PERCENT IN THE NORTHEAST FRIDAY NIGHT.
OTHERWISE...THE ECMWF IS THE ONLY MODEL SHOWING A COLD FRONT
BEHIND THIS SYSTEM ON SATURDAY...AND THEREFORE HAVE KEPT WINDS
SOUTHERLY WITH TEMPS NEAR NORMAL SUNDAY INTO MONDAY.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 80 62 65 39 61 / 0 5 20 20 20
WACO, TX 81 62 72 42 58 / 0 5 20 30 20
PARIS, TX 77 58 65 40 62 / 0 10 20 20 10
DENTON, TX 80 59 59 37 62 / 0 10 20 20 10
MCKINNEY, TX 78 61 64 38 62 / 0 10 20 20 10
DALLAS, TX 80 63 66 42 61 / 0 5 20 20 20
TERRELL, TX 79 60 69 41 61 / 0 5 20 20 20
CORSICANA, TX 81 62 74 44 59 / 0 5 20 30 20
TEMPLE, TX 81 62 74 43 58 / 0 5 20 30 20
MINERAL WELLS, TX 81 55 55 36 60 / 0 5 20 20 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
949 AM CDT MON APR 22 2013
.UPDATE...
WITH LESS CLOUDS THIS MORNING THAN PREVIOUSLY FORECASTED...HAVE
BUMPED UP HIGHS A COUPLE OF DEGREES ACROSS MOST OF THE AREA. DID
NOT GO QUITE AS HIGH AS WHAT THE RAP WAS FORECASTING /MID-80S/.
OTHERWISE...MADE MINOR CHANGES TO THE OTHER HOURLY GRIDS TO
ACCOUNT FOR CHANGES.
HAMPSHIRE
&&
.AVIATION...
/12Z TAFS/
CONCERNS...GUSTY WINDS TODAY AND MVFR CIGS TUESDAY MORNING.
STRATUS THIS MORNING HAS REMAINED WELL WEST OF THE TAF SITES.
SOUTH WINDS WILL INCREASE LATE THIS MORNING TO 15-18 KTS WITH
GUSTS AROUND 25 KTS. SPEEDS WILL DECREASE A LITTLE AROUND SUNSET
BUT CONTINUE TO BE BREEZY THROUGH THE END OF THE TAF PERIOD.
STRATUS WITH CIGS BETWEEN 1000-2000 FEET WILL SURGE NORTH OVER THE
REGION OVERNIGHT...REACHING WACO AROUND 08Z AND THE DFW
METROPLEX AROUND 09Z. LATE TUESDAY MORNING...A COLD FRONT WILL
ARRIVE IN THE METROPLEX WITH BREEZY NORTHWEST WINDS BEHIND THE
FRONT. THE FRONT WILL REACH WACO AROUND MIDDAY TOMORROW. THERE IS
A SMALL CHANCE FOR SHOWERS ALONG THE FRONT. MVFR CIGS WILL
CONTINUE BEHIND THE FRONT.
82/JLD
&&
.PREV DISCUSSION... /ISSUED 353 AM CDT MON APR 22 2013/
TODAY WILL BE BREEZY AND WARMER WITH PLENTY OF SUNSHINE BUT
CHANGES ARE ON THE WAY TOMORROW AS AN UNSEASONABLY STRONG COLD
FRONT MOVES THROUGH. WE CONTINUE TO FAVOR THE SLIGHTLY FASTER
FRONTAL TIMING OF NAM/WRF MODELS...WHICH SUGGEST THE FRONT WILL
REACH THE DFW METROPLEX AROUND 9-10 AM TUESDAY...WACO AROUND
NOON...AND PUSH OUT OF THE SE ZONES BY 4 PM. HIGH TEMPS TUESDAY
WILL OCCUR AHEAD OF THE FRONT...AND WILL BE VERY SENSITIVE TO
EXACT FRONTAL TIMING. TEMPS BEHIND THE FRONT WILL PLUNGE 15-25
DEGREES...AND EXPECT THE NW HALF OF THE CWA TO BE IN THE UPPER 40S
BY MID-LATE AFTERNOON TUESDAY WITH A BRISK NORTHERLY WIND MAKING
IT FEEL EVEN COLDER. THE AIRMASS ACROSS NORTH TEXAS WILL BE CAPPED
BY A STRONG TEMPERATURE INVERSION NEAR 750MB...AND THEREFORE DEEP
CONVECTION ALONG THE FRONT APPEARS UNLIKELY. HOWEVER...THE FRONT
WILL PLOW INTO A SATURATED COLUMN BENEATH THIS INVERSION...AND
RAPID MECHANICAL LIFTING WILL LIKELY SQUEEZE OUT A THIN LINE OF
SHOWERS ALONG THE FRONTAL BOUNDARY. WOULD EXPECT MOST LOCATIONS TO
SEE BRIEF LIGHT RAIN TOMORROW...BUT THE CHANCE OF MEASURABLE
RAINFALL IS LOW AND THEREFORE WILL KEEP POPS AT 20 PERCENT.
OTHERWISE SOME AREAS OF DRIZZLE MAY DEVELOP OVER NORTH TEXAS
BEHIND THE FRONT IN THE AFTERNOON HOURS.
COLD AIR ADVECTION WILL CONTINUE INTO TUESDAY NIGHT AND EXPECT
TEMPS TO FALL INTO THE MID-UPPER 30S ACROSS THE NORTHERN ZONES TO
MID-UPPER 40S IN THE SOUTH FOR LOWS. SOUTHWEST FLOW ALOFT WILL
PREVAIL IN THE WAKE OF THE FRONT WHICH WILL SET UP AN OVERRUNNING
TYPE PATTERN. A SHORTWAVE TROUGH WILL MOVE THROUGH CENTRAL/EAST
TEXAS TUESDAY NIGHT. ELEVATED MOISTURE/INSTABILITY ARE SUFFICIENT
FOR WIDELY SCATTERED ELEVATED SHOWERS AND A FEW STORMS WITH BEST
CHANCES OVER THE SOUTHEAST HALF OF THE AREA WITH THIS WAVE TUESDAY
NIGHT. MODEL GUIDANCE IS STRUGGLING WITH TRYING TO TIME A SECOND
SUBSEQUENT SHORTWAVE. THE ECMWF IS POINTING AT WEDNESDAY NIGHT AND
THE GFS SEEMS TO HINT AT THIS AS WELL BUT SHOWS LITTLE QPF. THE
NAM/CANADIAN ARE EARLIER AND MORE FOCUSED ON WEDNESDAY. WILL BRUSH
SOME LOW POPS INTO WEDNESDAY BUT HOLD OFF ON BRINGING THEM INTO
WEDNESDAY NIGHT UNTIL WE GET MORE MODEL CONSISTENCY. THERE MAY BE
ENOUGH INSTABILITY FOR ELEVATED THUNDERSTORMS WITH THIS SECOND
SHORTWAVE BUT HAVE KEPT IT WORDED AS JUST SHOWERS FOR NOW. TEMPS
WEDNESDAY WILL BE IMPACTED SIGNIFICANTLY BY ANY POST-FRONTAL
CLOUDS/RAIN. WITH NORTH WINDS PREVAILING INTO WEDNESDAY AND CLOUDS
LIKELY TO PERSIST ACROSS AT LEAST THE SOUTHERN ZONES...HAVE
UNDERCUT GUIDANCE AND PUT HIGHS ONLY IN THE 50S THERE. THE
NORTHERN ZONES HAVE A BETTER CHANCE AT SEEING SOME LATE APRIL SUN
AND THEREFORE HAVE FORECAST WARMER TEMPS IN THE LOW 60S THERE.
COLD ADVECTION SHOULD WANE WEDNESDAY NIGHT AS WINDS TURN TO THE
EAST BUT CLOUDS SHOULD KEEP TEMPS FROM FALLING AS COOL AS GUIDANCE
SUGGESTS. BY THURSDAY...WINDS WILL TURN AROUND TO THE SOUTH BUT
STILL THINK THAT CLOUDS WILL BE PREVALENT AND TEMPER THE WARM UP.
HAVE UNDERCUT HIGHS FOR THURSDAY AND JUST WENT MID-UPPER 60S.
THE NEXT UPPER LEVEL SYSTEM IS A CLOSED LOW IN THE SUBTROPICAL
PACIFIC THAT WILL MELD WITH AN UPPER TROUGH OVER THE CONTINENT AND
MOVE ACROSS THE SOUTHERN PLAINS FRIDAY AND SATURDAY. STILL NOT
GETTING GREAT AGREEMENT IN THE MODELS WITH THIS FEATURE AND THE
ECMWF REMAINS THE STRONGEST/SLOWEST WITH IT. THE CANADIAN/UKMET
ARE PRETTY WEAK WITH THE FEATURE AND SUGGEST LIMITED QPF. THE GFS
SEEMS TO OFFER A COMPROMISE. WILL KEEP THE LOW POPS SPREAD ACROSS
THE AREA FRIDAY AND END THEM FROM WEST TO EAST SATURDAY. THE
AIRMASS ACROSS NORTH TEXAS WILL REMAIN FAIRLY COOL AND NOT HAVE
MUCH TIME TO RECHARGE OR DESTABILIZE AHEAD OF THIS SYSTEM...AND
THEREFORE WE MAY BE TOO STABLE OR CAPPED FOR A SIGNIFICANT
CONVECTIVE EVENT. THE CAP WOULD BE THE WEAKEST ACROSS THE
NORTHERN ZONES NEARER TO THE BETTER UPPER FORCING AND THEREFORE
HAVE BUMPED UP POPS TO 30 PERCENT IN THE NORTHEAST FRIDAY NIGHT.
OTHERWISE...THE ECMWF IS THE ONLY MODEL SHOWING A COLD FRONT
BEHIND THIS SYSTEM ON SATURDAY...AND THEREFORE HAVE KEPT WINDS
SOUTHERLY WITH TEMPS NEAR NORMAL SUNDAY INTO MONDAY.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 80 62 65 39 61 / 0 5 20 20 20
WACO, TX 81 62 72 42 58 / 0 5 20 30 20
PARIS, TX 77 58 65 40 62 / 0 10 20 20 10
DENTON, TX 80 59 59 37 62 / 0 10 20 20 10
MCKINNEY, TX 78 61 64 38 62 / 0 10 20 20 10
DALLAS, TX 80 63 66 42 61 / 0 5 20 20 20
TERRELL, TX 79 60 69 41 61 / 0 5 20 20 20
CORSICANA, TX 81 62 74 44 59 / 0 5 20 30 20
TEMPLE, TX 81 62 74 43 58 / 0 5 20 30 20
MINERAL WELLS, TX 81 55 55 36 60 / 0 5 20 20 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
85/85
AREA FORECAST DISCUSSION
NWS SPOKANE WA
908 PM PDT Sun Apr 21 2013
.SYNOPSIS...
A cold front will generate showers over the eastern Columbia basin
and light accumulating snow in the mountains of the Idaho
Panhandle this evening. Monday morning will be cold with
temperatures well below freezing region-wide. A warming and
drying trend is expected this week. By Thursday and Friday,
temperatures will be 8 to 10 degrees above average.
&&
.DISCUSSION...
Evening update: Shower activity along today`s cold front is
beginning to wane and push south of the region. As of 830PM...the bulk
of the showers were south of a line from Clarkia to Walla Walla.
This should be out of the region by midnight. Looking upstream, a
second batch of showers has redeveloped over the Northern Idaho
Panhandle between Sandpoint and Porthill, associated with one more
vort max within the cusp of the trof. HRRR has initialized this
activity well and suggest it will struggle to make it south of
I-90 but not I totally buy into this idea given similar
atmospheric conditions. As such, we have added a slight chance for
rain/snow showers along the spine of the WA/ID border.
Snow shower activity has also ceased at Lookout Pass and the main
travel threat at this time will be slick to icy roadways. I will
wait to see the evolution of this band of showers dropping in from
the north before totally cancelling.
Temperatures will be tricky tonight. There is a distinct boundary
of dry continental air from roughly Colville to Omak in which
dewpoints are in the teens to 20s and generally in the upper 20`s
to 30`s south of the boundary. All guidance suggest the drier air will
continue to seep southward with most locations drying out into the
20`s overnight. What makes the forecast difficult is determining
whether winds will remain breezy enough to keep temperatures from
bottoming out, especially at locations like Wenatchee and Moses
Lake which begin growing season tomorrow (4/23). Most guidance
cool these locations between 32-35F so a hard freeze is not
anticipated but outlying areas may dip closer to 30F and any
persons with sensitive plants may want to take proper precautions.
Given these locations were below freezing four nights ago and
growing season starts tomorrow, we will hold off on any freeze
highlights this evening. /sb
&&
.AVIATION...
00Z TAFS: A cold front laying from KEAT to KMLP at 00z will move
south through this evening into central ID by 06Z tonight.
Numerous valley rain and mountain snow showers along the front
will impact the KPUW and KLWS TAF sites through 06Z...with
scattered and decreasing showers from the north at the KGEG area
TAF sites until 02-03Z. MVFR Ceilings will be common with these
showers. Behind this front very dry low level air will move into
the region and bring clearing skies with VFR conditions to the
entire region after 06Z tonight and lasting through 00Z Tuesday.
Breezy north to northeast winds will impact the KEAT...KMWH and
KGEG through 15Z-18Z Monday as this dry dense air moves through
northern mountain gaps and fills the basin. /MJF
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 28 53 32 57 35 62 / 0 0 0 10 0 0
Coeur d`Alene 27 52 28 57 32 61 / 20 0 0 20 10 0
Pullman 28 51 29 56 33 62 / 20 0 0 0 0 0
Lewiston 34 57 32 62 37 68 / 70 10 0 0 0 0
Colville 28 59 28 63 33 66 / 0 0 0 20 10 0
Sandpoint 27 51 27 55 30 59 / 20 0 0 20 10 0
Kellogg 26 47 29 52 32 59 / 20 0 0 20 20 0
Moses Lake 31 61 32 67 37 70 / 10 0 0 0 0 0
Wenatchee 33 60 36 64 40 67 / 0 0 0 0 0 0
Omak 26 60 29 64 35 68 / 0 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 6 AM PDT Monday for Central
Panhandle Mountains.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
347 PM CDT MON APR 22 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 347 PM CDT MON APR 22 2013
POSITIVITY TILTED UPPER LEVEL TROUGH MOVING THROUGH WITH A FEW
EMBEDDED SHORTWAVES NOTED THAT WILL IMPACT THE REGION TONIGHT AND
TUESDAY...ONE ACROSS THE NORTHERN PLAINS...AND A SECOND ROTATING
THROUGH THE INTERMOUNTAIN WEST. AT THE SURFACE...MAIN AREA OF LOW
PRESSURE IS SITUATED IN SOUTHWESTERN KANSAS...WITH A SECONDARY LOW
DEVELOPING NEAR KANSAS CITY. A WARM FRONTAL BOUNDARY EXTENDS
NORTHEAST TO NEAR DES MONIES...LA CROSSE...AND WAUSAU. DEFORMATION
BANDING PRECIPITATION IS DEVELOPING ALONG AND NORTH OF THE
FRONT...LIFTING THROUGH THE AREA THIS AFTERNOON.
NEAR-TERM GUIDANCE AND MESO-MODEL SOLUTIONS IN GOOD AGREEMENT
SHOWING LOW PRESSURE RIDING ALONG THIS BOUNDARY TONIGHT...CENTERING
NEAR LA CROSSE BY 06Z. STRONG FRONTOGENETICAL FORCING ON THE
NORTHWEST SIDE WILL KEEP DEFORMATION BAND PRECIPITATION IN PLACE
ACROSS SOUTHERN MINNESOTA INTO PARTS OF WESTERN WISCONSIN.
BIGGEST FORECAST CONCERN REMAINS ON WHEN PRECIPITATION WILL
TRANSITION FROM RAIN TO A RAIN/SNOW MIX...THEN TO ALL SNOW...AND
WHAT SNOWFALL ACCUMULATIONS RESULT. 22.12Z PROBABILISTIC AND
DETERMINISTIC GUIDANCE DID NOT VARY TOO MUCH FROM PREVIOUS
RUNS...AND STILL POINT TO SOUTHERN INTO CENTRAL MINNESOTA...AND
THEN INTO NORTHWEST WISCONSIN WITH THE HIGHER THREAT OF
ACCUMULATING SNOW. LOCALLY...THE MOST CONCERN IS FOR EXTREME
NORTHWEST DODGE/WABASHA COUNTIES IN MINNESOTA...AND TAYLOR COUNTY
IN WISCONSIN WHERE 1 TO 2 INCHES ARE POSSIBLE. THIS CHANGE OVER IS
EXPECTED AROUND MIDNIGHT OR SO...SLOWLY WORKING EAST DURING THE
OVERNIGHT.
CROSS SECTIONS THROUGH SOUTHEAST MINNESOTA SHOW STRONG SLOPING
FRONTOGENETIC SIGNAL WITH NEGATIVE EPV ABOVE...SO CONVECTIVE ELEMENTS
ARE POSSIBLE. THIS WOULD ENHANCE PRECIPITATION RATES...AND ALLOW
DYNAMIC COOLING TO WIN OUT. END RESULT...THERE COULD BE QUICK
BURSTS OF SNOW IN THESE AREAS AND THIS WILL BE SOMETHING TO WATCH
CLOSELY TONIGHT. RIGHT NOW THE HIGHER THREAT IS JUST OFF TO THE
NORTHWEST.
SOUNDINGS SHOW THE ATMOSPHERE LOSES ICE SATURATION OVERNIGHT AS
SURFACE TEMPERATURES COOL TO NEAR FREEZING. COMBINED WITH A
RETREATING WARM NOSE AT 850 MB....THERE IS A BRIEF FREEZING RAIN
OR FREEZING DRIZZLE THREAT ACROSS PORTIONS OF SOUTHEAST MINNESOTA
INTO NORTH CENTRAL WISCONSIN. 22.09Z SREF PROBABILITIES DEPICT A
10 TO 30 PERCENT PROBABILITY AS WELL. HAVE INCREASED THIS SOME
FROM PREVIOUS FORECAST...AND A VERY MINOR GLAZE IS POSSIBLE.
FOR TUESDAY...THE SURFACE LOW IS EXPECTED TO LIFT INTO THE GREAT
LAKES AND THERE SHOULD BE A QUICK WEST TO EAST END TO PRECIPITATION
IN THE MORNING HOURS. PLAN ON BLUSTERY NORTHWEST WINDS 10 TO 20
MPH...WITH HIGHER GUSTS UP TO 30 MPH. SKIES WILL CLEAR DURING THE
AFTERNOON AS DRIER AIR WORKS IN ACROSS THE AREA ALONG WITH SURFACE
HIGH PRESSURE BUILDING IN. FINALLY...TEMPERATURES WILL BE NEARLY 20
DEGREES BELOW NORMAL..WITH LOWER 40S COMMON ACROSS THE AREA.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 347 PM CDT MON APR 22 2013
FOCUS IN THE LONG TERM IS ON A RATHER VIGOROUS NORTHERN STREAM
SHORTWAVE FOR WED/WED NIGHT...THEN LOOKING FORWARD TO THE
MUCH-ANTICIPATED FIRST SPRING WARM UP THAT IS POSSIBLE THIS WEEKEND.
FOR WEDNESDAY A POTENT SHORTWAVE TROUGH IS EXPECTED TO QUICKLY DIVE
OUT OF THE NORTHERN PLAINS IN THE AFTERNOON AND EVENING HOURS. THIS
SYSTEM IS CHARACTERIZED BY VERY STEEP LOW-LEVEL LAPSE RATES THANKS
TO AN ANOMALOUSLY COLD MID/UPPER LEVEL CORE. 500 MB STANDARDIZED
ANOMALIES OFF THE 22.00Z ECMWF VARY FROM 2 TO 2.5 SD BELOW NORMAL.
ALTHOUGH MOISTURE CONVERGENCE IS LACKING...THE MID/UPPER LEVEL
DYNAMICS LOOK TO BE SUFFICIENT ENOUGH TO WARRANT HIGHER
PRECIPITATION CHANCES. THERE REMAINS SOME TIMING DIFFERENCE BETWEEN
22.12 GUIDANCE...AND THE LATER ARRIVAL WOULD POINT TOWARD MORE A
RAIN/SNOW MIX. LOCATIONS NORTH OF I-94 COULD PICK UP A 1/2 INCH OF
SNOW LATE WEDNESDAY NIGHT AS COOLING CHANGES RAIN OVER TO WET SNOW.
THE LATE WEEK INTO THE UPCOMING WEEKEND FEATURES RETURN SOUTHWESTERLY
FLOW AS THE UPPER LEVEL FLOW RIDGING TAKES SHAPE. 850 MB
TEMPERATURES RISE FROM AROUND -5C ON THURSDAY...TO AS HIGH AS +10 TO
+14C BY SUNDAY. HIGHS FRIDAY/SATURDAY WILL RISE INTO THE 60S...WITH
LOW 70S POSSIBLE SUNDAY/MONDAY. DESPITE WARM TEMPERATURES...A
LINGERING BOUNDARY TO THE NORTH WARRANTS SLIGHT CHANCES NORTH OF
I-90 SATURDAY NIGHT INTO SUNDAY. THIS WILL BE WELCOME NEWS TO THOSE
WHO ARE LOOKING FORWARD TO SOME SPRING WEATHER...HOWEVER THIS COULD
POTENTIALLY CREATE HYDROLOGY ISSUES...SO SEE HYDROLOGY SECTION FOR
MORE DETAILS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1218 PM CDT MON APR 22 2013
SURFACE FRONT IS BISECTING THE AREA EXTENDING FROM ABOUT KMCW TO
KLSE TO KRRL. THE 22.15Z RAP ALONG WITH THE 22.12Z HRRR AND 22.06Z
HI-RES ARW AND NMM ALL SUGGEST THE EASTERN PART OF THE FRONT WILL
LIFT SLOWLY NORTH THROUGH THE AFTERNOON WHILE THE WESTERN PART
REMAINS NEARLY STATIONARY. THIS WOULD ALLOW THE FRONT TO LIFT
BACK THROUGH KLSE BRINGING IN THE WARM SECTOR WHILE KRST WOULD
STAY ON THE COOL SIDE OF THE FRONT. HAVE INDICATED THESE TRENDS
WITH THE WINDS COMING AROUND TO THE EAST/SOUTHEAST AT KLSE WITH
VFR CONDITIONS FOR THE MID TO LATE AFTERNOON. WITH KRST STAYING ON
THE COOL SIDE OF THE FRONT...EXPECTING IFR CONDITIONS FOR THE
REMAINDER OF THE AFTERNOON. THE NEXT SHORT WAVE TROUGH...CURRENTLY
OVER SOUTH DAKOTA AND NEBRASKA...WILL MOVE IN THIS EVENING WITH AN
INCREASE IN THE FORCING. AT THE SAME TIME...THE FRONTOGENESIS IN
THE 1000-700 MB LAYER IS EXPECTED TO BE STRONG ALONG THE FRONT
CAUSING A WIDESPREAD AREA OF RAIN TO DEVELOP AND MOVE ACROSS THE
REGION OVERNIGHT. ENOUGH COLD AIR IS EXPECTED TO COME IN AT KRST
FOR THE RAIN TO MIX WITH SNOW AROUND 06Z. THE NAM SOUNDINGS
SUGGEST THE POTENTIAL FOR ICE IN THE CLOUDS TO BE LOST AND THE
PRECIPITATION POSSIBLY BECOMING DRIZZLE OR FREEZING DRIZZLE BASED
ON TEMPERATURES. SOME POTENTIAL FOR A SHORT PERIOD OF FREEZING
DRIZZLE AND HAVE INCLUDED THIS FOR LATE TONIGHT BEFORE THE
PRECIPITATION ENDS AROUND 12Z. KLSE IS EXPECTED TO REMAIN WARM
ENOUGH FOR JUST RAIN AT THIS POINT BEFORE THE IT ENDS SHORTLY
AFTER 12Z.
&&
.HYDROLOGY...TONIGHT/TUESDAY
ISSUED AT 347 PM CDT MON APR 22 2013
THE TONIGHT/TUESDAY EVENT IS EXPECTED TO RESULT IN 0.5 TO UP 1.0
INCH OF LIQUID ACROSS PORTIONS OF SOUTHEAST MINNESOTA AND WESTERN
INTO CENTRAL WISCONSIN. SATURATED GROUND FROM THE RECENT
RAINFALL...ALONG WITH SNOWPACK REMAINING IN PLACE ACROSS CENTRAL
MINNESOTA INTO NORTH CENTRAL WISCONSIN WILL KEEP AN ELEVATED RISK
OF HYDROLOGY ISSUES. FORECAST RAINFALL AMOUNTS BRING THE
TREMPEALEAU RIVER AT DODGE POTENTIALLY ABOVE FLOOD STAGE LATER
THIS WEEK BUT GIVEN SOME UNCERTAINTY IN WHAT BASINS WILL EXPERIENCE
THE HIGHER AMOUNTS...AT THIS TIME A FLOOD WATCH WAS POSTED.
LOOKING AHEAD...THE POSSIBLE SIGNIFICANT WARM UP ACROSS THE UPPER
MIDWEST THIS WEEKEND INTO EARLY NEXT WEEK COULD LEAD TO RAPID
SNOWMELT ACROSS CENTRAL MINNESOTA AND THE NORTHERN HALF OF
WISCONSIN. THIS WOULD LEAD TO SIGNIFICANT RISES ON AREA
TRIBUTARIES SUCH AS THE BLACK AND TREMPEALEAU RIVER...AND
EVENTUALLY ON THE MAIN STEM OF THE MISSISSIPPI RIVER. CURRENT
FORECASTS SHOW 1 TO 2 FEET RISES ON THE MISSISSIPPI BY THIS
WEEKEND...ABOVE ACTION STAGE AT MANY SITES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 9 AM CDT
TUESDAY FOR WIZ017.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZT
LONG TERM...ZT
AVIATION...04
HYDROLOGY...ZT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1218 PM CDT MON APR 22 2013
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 255 AM CDT MON APR 22 2013
SHOWERS CONTINUE TO TRACK ALONG A NORTHEAST-SOUTHWEST RUNNING COLD
FRONT...EXTENDING FROM NORTHEAST WI...ACROSS THE HEART OF THE
FORECAST AREA...AND THEN ACROSS SOUTHERN IA. THE FRONT MAKES VERY
SLOW PROGRESS TO THE EAST...ESSENTIALLY STAYING HUNG UP ACROSS THE
FORECAST AREA INTO TONIGHT. EXPECTING SOME DECREASE IN AREAL EXTENT
OF THE SHOWERS THIS MORNING AS THE LOW LEVEL MOISTURE TRANSPORT
WEAKENS. THESE SHOULD START TO BECOME MORE NUMEROUS THIS AFTERNOON
AS THE FRONTOGENETIC FORCING INCREASES...MOSTLY ALONG AND NORTH OF
THE SFC BOUNDARY...ACTING MORE AS A WARM FRONT NOW. BETTER CHANCES
IN THE NORTH.
TONIGHT...PRECIPITATION WILL CONTINUE TO EXPAND AS A SFC LOW MOVES
OUT OF THE PLAINS TO ACROSS THE FORECAST AREA BETWEEN 03-06Z. GOOD
AMOUNT OF LOW LEVEL WARM AIR ADVECTION...WITH SLOPING FRONTOGENETIC
FORCING INDICATED IN A NORTHWEST-SOUTHEAST X-SECTION. SOME UPPER
LEVEL PIECES OF SHORTWAVE ENERGY WILL BE ADDED TO THE FORCING
MIX...WITH A COUPLED UPPER LEVEL JET AS THE CHERRY ON TOP. THE BULK
OF THIS PRECIPITATION WILL FALL IN THE TRADITIONAL DEFORMATION
REGION NORTHWEST OF THE SFC LOW...SO WHERE THIS TRACKS WILL BE
PARAMOUNT TO REFINING THE HIGHER PCPN CHANCES...AND AMOUNTS. THERE
WILL STILL BE SOME SHOWER CHANCES ALONG THE SOUTHERN PART OF THE
BOUNDARY...THE COLD FRONT PORTION OF THE LOW PRESSURE SYSTEM. THIS
AREA COULD SEE A FEW ISOLATED THUNDERSTORMS WITH A BIT OF
INSTABILITY TO TAP INTO.
IN THE NORTHWEST/DEFORMATION REGION...TEMP PROFILES VIA X-SECTIONS
AND BUFKIT SOUNDINGS WOULD SUPPORT A RAIN/SNOW TO SNOW PCPN TYPE.
LOOKING AT SIGNIFICANT SNOW ACCUMULATIONS OVER CENTRAL MN INTO
NORTHWEST WI. LOCALLY...THE BEST CHANCES FOR SNOW ACCUMS WILL BE
NORTH OF HIGHWAY 29 IN NORTH CENTRAL WI WHERE 1 TO 4 INCHES COULD BE
ON THE GROUND FOR THE TUE MORNING COMMUTE. MOST OF THIS WILL BE ON
COLDER/GRASSY SFCS...BUT MOST ROADS WILL LIKELY HAVE SOME SNOW ON
THEM. WITH THIS IN MIND...WILL ISSUE A WINTER WEATHER ADVISORY FOR
LATE THIS EVENING THROUGH THE MORNING RUSH HOUR ON TUESDAY FOR
TAYLOR COUNTY.
.LONG TERM...(TUESDAY THROUGH MONDAY)
ISSUED AT 255 AM CDT MON APR 22 2013
22.00Z GFS AND NAM SOLUTIONS CONTINUE TO FAVOR A 500 MB SHORTWAVE
TROUGH DROPPING SOUTHEAST ACROSS THE NORTHERN PLAINS...TO ACROSS THE
UPPER MISSISSIPPI RIVER VALLEY BY 06Z THU. GOOD PUNCH OF MID/UPPER
LEVEL QG CONVERGENCE WITH THE FEATURE...ESPECIALLY IN THE 700-300 MB
LAYER. NOT MUCH LOW LEVEL THERMODYNAMICS NOR APPRECIABLE SOUTHERN
MOISTURE FETCH. STILL...ENOUGH FOR A GOOD/LIKELY SHOT FOR PCPN.
TIMING OF THE SHORTWAVE WOULD MAKE A RAIN...TO RAIN/SNOW...TO SNOW
TRANSITION ALSO LIKELY. COULD SEE MINOR SNOW ACCUMULATIONS ON
GRASSY/COLD SFCS. WINTER CERTAINLY ISN/T DONE WITH US QUITE YET.
THE UPPER LEVEL FLOW TURNS MORE ZONAL AND IS FAIRLY PROGRESSIVE
HEADING INTO THE WEEKEND. MOST BITS OF SHORTWAVE ENERGY ARE SHUNTED
NORTH OR SOUTH OF THE FORECAST AREA...BUT THE GFS AND EC DO SUGGEST
THAT A SHORTWAVE COULD SLIDE ACROSS NORTHERN PARTS OF THE REGION SAT
NIGHT/SUN. PCPN WOULD RESULT...BETTER IN THE NORTH...BUT ALSO ALONG
THE SYSTEM/S LEADING FRONT...WHICH COULD IMPACT US.
MORE SIGNIFICANTLY IS THE LIKELIHOOD THAT
SPRING...NORMAL...TEMPERATURES FINALLY MAKE AN APPEARANCE.
SOUTHERLY WINDS OUT AHEAD OF THE SAT NIGHT SYSTEM WILL PUSH TEMPS
UP...AND ITS LOOKING MORE AND MORE LIKELY THAT HIGHS WILL JUMP INTO
THE 60S FOR FRI/SAT/SUN. CAN/T RULE OUT A FEW 70S THIS WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1218 PM CDT MON APR 22 2013
SURFACE FRONT IS BISECTING THE AREA EXTENDING FROM ABOUT KMCW TO
KLSE TO KRRL. THE 22.15Z RAP ALONG WITH THE 22.12Z HRRR AND 22.06Z
HI-RES ARW AND NMM ALL SUGGEST THE EASTERN PART OF THE FRONT WILL
LIFT SLOWLY NORTH THROUGH THE AFTERNOON WHILE THE WESTERN PART
REMAINS NEARLY STATIONARY. THIS WOULD ALLOW THE FRONT TO LIFT
BACK THROUGH KLSE BRINGING IN THE WARM SECTOR WHILE KRST WOULD
STAY ON THE COOL SIDE OF THE FRONT. HAVE INDICATED THESE TRENDS
WITH THE WINDS COMING AROUND TO THE EAST/SOUTHEAST AT KLSE WITH
VFR CONDITIONS FOR THE MID TO LATE AFTERNOON. WITH KRST STAYING ON
THE COOL SIDE OF THE FRONT...EXPECTING IFR CONDITIONS FOR THE
REMAINDER OF THE AFTERNOON. THE NEXT SHORT WAVE TROUGH...CURRENTLY
OVER SOUTH DAKOTA AND NEBRASKA...WILL MOVE IN THIS EVENING WITH AN
INCREASE IN THE FORCING. AT THE SAME TIME...THE FRONTOGENESIS IN
THE 1000-700 MB LAYER IS EXPECTED TO BE STRONG ALONG THE FRONT
CAUSING A WIDESPREAD AREA OF RAIN TO DEVELOP AND MOVE ACROSS THE
REGION OVERNIGHT. ENOUGH COLD AIR IS EXPECTED TO COME IN AT KRST
FOR THE RAIN TO MIX WITH SNOW AROUND 06Z. THE NAM SOUNDINGS
SUGGEST THE POTENTIAL FOR ICE IN THE CLOUDS TO BE LOST AND THE
PRECIPITATION POSSIBLY BECOMING DRIZZLE OR FREEZING DRIZZLE BASED
ON TEMPERATURES. SOME POTENTIAL FOR A SHORT PERIOD OF FREEZING
DRIZZLE AND HAVE INCLUDED THIS FOR LATE TONIGHT BEFORE THE
PRECIPITATION ENDS AROUND 12Z. KLSE IS EXPECTED TO REMAIN WARM
ENOUGH FOR JUST RAIN AT THIS POINT BEFORE THE IT ENDS SHORTLY
AFTER 12Z.
&&
.HYDROLOGY...
ISSUED AT 255 AM CDT MON APR 22 2013
STILL LOOKING AT AN ADDITIONAL 1/3 TO 1 INCH OF LIQUID EQUIVALENT
PCPN TODAY AND TONIGHT...MORE ACROSS WESTERN/NORTHERN PARTS OF THE
FORECAST AREA. GROUNDS ARE SATURATED AND MUCH OF WHAT FALLS COULD GO
INTO RUNOFF INTO THE WATER WAYS. THIS WOULD LEAD TO WITHIN BANK
RISES...BUT ADDITIONAL FLOODING IS NOT ANTICIPATED. IF THE AMOUNTS
ARE HIGHER THAN EXPECTED...OR IT COMES DOWN IN A SHORTER PERIOD OF
TIME...THE FLOOD THREAT WOULD INCREASE. THE CURRENT FLOODING ON THE
BLACK RIVER WILL CONTINUE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 9 AM CDT
TUESDAY FOR WIZ017.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM....RIECK
LONG TERM.....RIECK
AVIATION...04
HYDROLOGY.....RIECK
AREA FORECAST DISCUSSION
NWS PADUCAH KY
336 AM CDT WED APR 24 2013
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 336 AM CDT WED APR 24 2013
BOTH THE SURFACE COLD FRONT AND THE MAIN POST-FRONTAL BAND OF
SHOWERS AND THUNDERSTORMS ARE TAKING THEIR SWEET TIME TONIGHT. AS
OF 08Z...THE COLD FRONT WAS LOCATED FROM NEAR FT CAMPBELL TO NEAR
GREENVILLE KENTUCKY...AND THE BAND OF CONVECTION WAS LOCATED ALONG
AND NORTHWEST OF A LINE FROM DONIPHAN MISSOURI TO MARION AND MT
CARMEL ILLINOIS. WATER VAPOR IMAGERY SHOWS THE MAIN MID/UPPER
LEVEL IMPULSE PIVOTING EASTWARD OVER THE SOUTHERN/CENTRAL PLAINS.
THIS SHOULD HELP TO GIVE THE MAIN BAND A GOOD PUSH...AND MAY CAUSE
IT TO PIVOT TO MORE OF A SOUTH SOUTHWEST TO NORTH NORTHEAST
ORIENTATION THROUGH SUNRISE.
USED THE LATEST RAP AS A GUIDE FOR HOURLY POP GRIDS THROUGH THE
END OF THE EVENT. SHOULD SEE THE MAIN BAND PUSH SOUTHWARD TOWARD
THE OHIO RIVER THROUGH SUNRISE...AND THEN GRADUALLY COME TO AN END
FROM WEST TO EAST THROUGH THE MORNING. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL CONTINUE IN THE VICINITY OF THE
FRONT IN THE SOUTHERN PENNYRILE THROUGH DAYBREAK...BUT THE MAIN
BAND MAY NOT QUITE GET DOWN THAT FAR SOUTHEAST BEFORE BEING FORCED
EAST OF THE AREA.
THE SURFACE HIGH WILL PUSH EASTWARD ACROSS THE AREA THROUGH THE
DAY WHICH SHOULD LEAD TO A NICE CLEARING TREND AND DIMINISHING
WINDS. WINDS WILL GO NEARLY CALM THIS EVENING AS THE SURFACE HIGH
BRIEFLY SETTLES OVER THE REGION. BUT OVERNIGHT...A WEAK SURFACE
TROUGH ASSOCIATED WITH A CLIPPER SYSTEM DIVING THROUGH THE GREAT
LAKES WILL INDUCE SOUTHWEST WIND MAINLY OVER THE NORTHERN HALF OF
THE AREA. FEEL THAT MOST PLACES WILL DROP TO THE MID 30S FOR LOWS
TONIGHT...BUT THE WIND SHOULD KEEP FROST FROM BEING DEPOSITED LATE
TONIGHT. THE MOST LIKELY PLACE TO SEE SOME FROST MAY VERY WELL BE
OVER THE SOUTHERN HALF OF THE AREA. DO NOT HAVE ANY FROST IN THIS
FORECAST...BUT MAY NEED TO ADD IT IN IF CONFIDENCE INCREASES TODAY.
THE NAM GENERATES SOME RATHER GUSTY NORTHWEST WINDS BEHIND THE
CLIPPER SYSTEM THURSDAY...ESPECIALLY OVER THE NORTHEAST. INCREASED
WINDS SOME...BUT DID NOT GO UP TO NAM LEVELS AT THIS TIME.
SURFACE HIGH PRESSURE WILL DOMINATE THE REGION AGAIN FOR MOST OF
THURSDAY NIGHT. IT WILL GRADUALLY PUSH EAST OF THE AREA WHICH MAY
ALLOW FOR A LIGHT SOUTHEAST WIND TO DEVELOP LATE IN THE WEST. THE
MODELS ALSO SHOW SOME INCREASE IN CLOUD COVER IN THE WEST LATE
THURSDAY NIGHT. THE BOTTOM LINE IS THE POTENTIAL FOR TEMPERATURES
TO DROP INTO THE 30S AGAIN...ESPECIALLY EAST OF THE MISSISSIPPI
RIVER. OF COURSE WILL HAVE TO WATCH FOR FROST POTENTIAL AS WELL.
THE MODELS SEEM TO BE TRENDING SLOWER AND FARTHER SOUTH WITH THE
QPF ASSOCIATED WITH THE RATHER WEAK MID-LEVEL TROUGH PUSHING OUT
OF THE SOUTHERN/CENTRAL PLAINS FRIDAY. LOWERED POPS AND CONFINED
GOOD CHANCE POPS TO SOUTHEAST MISSOURI IN THE AFTERNOON ONLY.
LOOKS LIKE IT WILL BE MORE OF A STRATIFORM EVENT SO JUST MENTIONED
RAIN.
AS FOR TEMPERATURES...STAYED NEAR CONSENSUS OF GUIDANCE FOR HIGHS
TODAY...BUT IN GENERAL FEEL THAT THE LOW END OF GUIDANCE IS THE
PLACE TO BE FOR TONIGHT THROUGH FRIDAY. THE LONE EXCEPTION IS IN
THE SOUTHWEST THURSDAY NIGHT...IF CLOUDS OR WINDS INCREASE.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 336 AM CDT WED APR 24 2013
WHILE STILL NOT COMPLETELY IN SYNC...LATEST MODEL OUTPUT HAS COME
INTO BETTER ALIGNMENT WITH RESPECT TO THE SOUTHERN STREAM ENERGY
FORECAST TO IMPACT THE REGION LATE IN THE WEEK. THERE IS CERTAINLY
A TREND TO SHIFT THE MAIN FOCUS FOR PRECIPITATION TO THE SOUTH OF
THE IMMEDIATE FORECAST AREA...MUCH AKIN TO WHAT THE ECMWF HAS BEEN
INDICATING. THE SURFACE BOUNDARY IS NOW FORECAST BY ALL MODELS TO
REMAIN SOUTH OF THE REGION...WHICH KEEPS SURFACE BASED INSTABILITY
AT BAY. TO THAT EXTENT...ELEVATED INSTABILITY PARAMETERS ARE ALSO
LACKING WITH THIS SYSTEM. THE END RESULT WAS TO ELIMINATE THE
MENTION OF THUNDER FROM THE FRIDAY NIGHT/SATURDAY FORECAST.
THE HIGHEST LIKELIHOOD FOR RAIN SHOWERS STILL APPEARS TO BE FRIDAY
NIGHT INTO EARLY SATURDAY...WITH BETTER CHANCES SOUTH...SMALLER
CHANCES NORTH. EXCEPT FOR THE GFS...MODELS ARE ALSO TRENDING DRIER
LATE IN THE WEEKEND. KEPT SMALL CHANCES FOR SHOWERS OVER FAR EASTERN
AREAS SATURDAY NIGHT AND SUNDAY AS THIS AREA WILL BE ON THE WESTERN
PERIPHERY OF THE DEPARTING ENERGY.
HIGH PRESSURE RIDGING IS FORECAST TO STRENGTHEN OVER THE EASTERN
U.S. EARLY NEXT WEEK. CONSIDERING THE AMPLITUDE OF THIS RIDGE...THE
GFS MAY BE TOO QUICK WITH THE APPROACH OF THE NEXT TROUGH AND ITS
ASSOCIATED PRECIPITATION POTENTIAL. MAINTAINED SLIGHT CHANCE POPS IN
THE TUESDAY FORECAST FOR NOW...BUT WOULD NOT BE SURPRISED TO SEE IT
PUSHED TO LATER PERIODS PER THE 00Z ECMWF. A SLOW WARMING TREND IS
EXPECTED THROUGH THE PERIOD.
&&
.AVIATION...
ISSUED AT 1157 PM CDT TUE APR 23 2013
LOW MVFR CIGS WILL GRADUALLY LOWER TO LOW MVFR/IFR AS MORE
WIDESPREAD SHRA DEVELOP AND SPREAD SOUTHEAST ACROSS TAF SITES
BETWEEN 08Z AND 12Z. MVFR VSBYS EXPECTED WITH SHRA. ISOLATED TSRA
POSSIBLE...BUT CHANCES ARE TOO LOW TO INCLUDE. WINDS WILL BE FROM
THE NORTHWEST AT 8 TO 15 KTS WITH SOME HIGHER GUSTS. SHRA WILL
TAPER OFF FROM NORTHWEST TO SOUTHEAST AFTER 14Z.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...DRS
LONG TERM...RP
AVIATION....RST
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
350 AM EDT WED APR 24 2013
.SHORT TERM...TODAY AND TONIGHT
BY FORECAST ISSUANCE TIME...WEAK SFC LOW PRESSURE AND A COLD FRONT
WILL BE PUSHING EAST OF METRO DETROIT AND PORT HURON. THERE HAS BEEN
A FAIRLY WIDESPREAD AREA OF RAINFALL ACROSS SE MI ALONG AND BEHIND
THE SFC FRONT LAST NIGHT WITHIN A REGION OF STRONG LOWER
TROPOSPHERIC FRONTOGENESIS. THE HEAVIER AND MORE PERSISTENT RAINFALL
HAS OCCURRED WITHIN THE 800-700MB LAYER OF THE FRONTAL SLOPE. THIS
TARGETED THE TRI CITIES AND SAGINAW BAY REGION WHERE RADAR
ESTIMATED RAINFALL IS ALREADY AROUND AN INCH. THE REGION OF HIGHER
INTENSITY RAINFALL IS EXPECTED TO SHIFT INTO THE THUMB REGION DURING
THE EARLY MORNING HOURS. GIVEN THE ESTIMATED RAINFALL AND WITH THE
EXPECTATION FOR HIGHER INTENSITY RAINFALL TO PUSH INTO THE
THUMB...THE FLOOD WATCH WILL BE CONTINUED THROUGH DAYBREAK. THERE
HAVE BEEN A FEW AWOS SITES WHICH HAVE REPORTED SNOW OVERNIGHT...
WHICH IS INCORRECT. ALL PRECIP THUS FAR HAS BEEN IN THE FORM OF
RAIN. THE NAM AND GFS SOLUTIONS APPEAR TOO COOL IN THE BOUNDARY
LAYER THIS MORNING IN COMPARISON TO OBSERVATIONS...WITH THE RAP
SOUNDINGS APPEARING TO HAVE A BETTER HANDLE ON THE LOW LEVEL THERMAL
PROFILES. THE RAP IS SUGGESTIVE OF PRECIP REMAINING MOSTLY RAIN THIS
MORNING...EXPECT ACROSS THE TRI CITIES AND THUMB WHERE COLDER AIR
CONTINUES TO FILTER IN FROM THE NW AND IS LIKELY TO CAUSE A MIX OR
BRIEF CHANGE OVER TO SNOW.
THE LOW TO MID LEVEL FGEN RESPONSE WILL WEAKEN TOWARD DAYBREAK
THROUGH LATE MORNING DUE TO THE LOW LEVEL THERMAL GRADIENT RELAXING
AS SFC LOW PRESSURE AND BETTER UPPER DYNAMICS SHIFT OFF TO THE
NORTHEAST. THIS WILL LEAD TO A STEADY DECREASE IN COVERAGE AND
INTENSITY OF THE RAINFALL. HOWEVER...THE UPPER LEVEL WAVE NOTED OVER
KANSAS IS FORECAST TO RAPIDLY LIFT ACROSS THE NRN OH VALLEY AND ERN
GREAT LAKES THIS AFTERNOON. MODEL SOLUTIONS HAVE TRENDED TOWARD A
DEEPER UPPER WAVE/STRONGER UPPER LEVEL POTENTIAL VORTICITY ADVECTION
WITH THIS FEATURE AND APPEAR WELL INITIALIZED. AS IT LIFTS NE THIS
AFTERNOON...SOME WEAK MID LEVEL DEFORMATION WILL OVERSPREAD SE MI...
ESPECIALLY THE EASTERN HALF OF THE FORECAST AREA. AN INTENSIFICATION
OF AN UPPER JET STREAK WILL OCCUR ACROSS LOWER MI AND LAKE HURON AS
WELL...WITH INCREASING DIVERGENCE OVERSPREADING OHIO...LAKE ERIE AND
FAR EASTERN PORTIONS OF SE MI. THIS FORCING WILL INTERACT WITH THE
BACK EDGE OF THE DEEPER MOISTURE PLUME OVER SE MI...SUGGESTING
RAINFALL WILL INCREASE IN COVERAGE AGAIN DURING THE AFTERNOON. THE
RATHER MARGINAL FORCING SUGGEST ADDITIONAL DAYTIME RAINFALL AMOUNTS
WILL GENERALLY REMAIN BELOW A QUARTER INCH. THE EXPECTATION FOR
ENOUGH DAYTIME WARMING IN THE BOUNDARY LAYER SUPPORTS PRECIP TYPE AS
ALL RAIN TODAY. ALTHOUGH WITH 850MB TEMPS FORECAST TO DROP TO
-5C...THERE WAS SOME SERIES CONTEMPLATION OVER ADDING A MENTION OF
SOME SNOW NORTH OF METRO DETROIT.
THE EXTENT OF CLOUDS AND RAIN TODAY...WITH DWPTS DROPPING INTO THE
LOW 30S...WILL SUPPRESS TEMPS TO THE MID 30S TO LOWER 40S WELL INTO
THE AFTERNOON. A PUSH OF DRIER AIR LATE IN THE AFTERNOON AND EVENING
WILL END THE RAIN AND CAUSE SOME PARTIAL CLEARING WHICH SHOULD ALLOW
A LATE DAY SPIKE IN TEMPS INTO THE MID-UPPER 40S. PARTIAL CLEARING
TONIGHT AMIDST SHORT WAVE RIDGING WILL ALLOW ENOUGH OPPORTUNITY FOR
NIGHTTIME COOLING TO DROP TEMPS WELL DOWN INTO THE 30S.
&&
.LONG TERM...THURSDAY THROUGH TUESDAY
STRONG UPPER WAVE OVER SASKATCHEWAN WILL DIVE DOWN INTO THE WESTERN
GREAT LAKES BY THURSDAY MORNING...AS IT ROTATES WITHIN THE LONGWAVE
TROUGH OVER THE CENTRAL U.S. AND CANADA. THIS WAVE WILL CLIP QUICKLY
ACROSS LOWER MICHIGAN AND INTO ONTARIO THURSDAY...PUSHING A WEAK LOW
PRESSURE SYSTEM ACROSS THE NORTHERN GREAT LAKES AND DRAGGING A COLD
FRONT ACROSS THE AREA. FRONTAL TIMING CONTINUES TO VARY WITHIN THE
MODELS...AND STRONG PREFERENCE GOES TO THE VERY CONSISTENT EURO
MODEL. GOOD BURST OF LIFT WILL ACCOMPANY THE COLD FRONT...WITH
FRONTAL DYNAMICS STACKED UNDERNEATH MID-LEVEL PVA AND LEFT EXIT
REGION FORCING. COLD AIR ALOFT REMAINING IN PLACE BEHIND TODAY`S
SYSTEM IN COMBINATION WITH H500 TEMPS DROPPING TO ABOUT -35C WITH
THE UPPER WAVE...WHICH HAS ARCTIC ORIGINS...WILL CREATE VERY
MODERATELY STEEP LOW AND MID-LEVEL LAPSE RATES (FROM SURFACE UP
THROUGH 400MB). DEEP LAYER OF INSTABILITY WILL HELP MAXIMIZE
RESPONSE FROM FORCING AND MAKE THE BEST OF ONLY MEAGER MOISTURE
(SHALLOW LAYER OF MOISTURE POOLING AHEAD OF FRONT WITH SPECIFIC
HUMIDITY 3 G/KG AND PW OVERALL ONLY AROUND 0.4 INCHES).
PRECIPITATION ASSOCIATED WITH THE FRONT WILL AFFECT THE AREA DURING
THE FIRST HALF OF THURSDAY...WITH ADDITIONAL SHOWERS POSSIBLY
REDEVELOPING DURING THE LATE AFTERNOON AS LAPSE RATES FURTHER
STEEPEN AND SOME MOISTURE LINGERS. PRECIPITATION TYPE IS STILL A
LITTLE UNCERTAIN WITH GFS/NAM FORECAST SOUNDINGS STILL HINTING THAT
SNOW MAY BE POSSIBLE...BUT GIVEN WARMER EURO PROFILES IN THE PAST
TWO MODEL RUNS...WILL KEEP PRECIP TYPE AS RAIN. WOULD ALSO EXPECT TO
SEE SOME GRAUPEL FALL AS SHOWERS WILL HAVE A CONVECTIVE ELEMENT TO
THEM AND FREEZING LEVELS WILL BE VERY LOW.
SURFACE HIGH PRESSURE WILL EXPAND INTO THE AREA FROM THE OHIO VALLEY
THURSDAY NIGHT AND FRIDAY BRINGING DRY WEATHER BACK TO THE AREA. LOW
PRESSURE TRACKING ACROSS HUDSON BAY WILL DRAW SOME WARMER AIR UP
INTO THE REGION ON FRIDAY...ALLOWING TEMPERATURES TO CREEP BACK UP
INTO THE UPPER 50S.
WEEKEND WILL BE MARKED BY ZONAL FLOW...WITH UPPER RIDGING BUILDING
INTO THE GREAT LAKES MONDAY AND TUESDAY IN RESPONSE TO TROUGHING
DROPPING DOWN INTO THE NORTHERN ROCKIES. WILL SEE A WARMING TREND
DURING THIS STRETCH...WITH MAX TEMPERATURES GRADUALLY WARMING TO
AROUND 70. MODELS HAVE BEEN TRYING TO GENERATE CONVECTION JUST ABOUT
EVERY AFTERNOON AS LAPSE RATES STEEPEN DURING THE DAY. GIVEN GENERAL
LACK OF GOOD MOISTURE ADVECTION (HAVE A FEELING SURFACE TD`S ARE TOO
HIGH AS WELL) AND EVENTUAL CAPPING FROM THE RIDGE...ELECTED TO KEEP
THE FORECAST DRY AND THUNDERSTORM FREE FOR NOW.
&&
.MARINE...
NORTHWEST WINDS IN THE WAKE OF LAST NIGHTS COLD FRONTAL PASSAGE HAS
USHERED IN COLDER AIR...LEADING TO UNSTABLE CONDITIONS OVER THE
LAKES. SOME GUSTS UP TO 25 KNOTS ARE EXPECTED OVER THE OPEN WATERS
OF LAKE HURON. THESE CONDITIONS SHOULD BE SHORT LIVED AS HIGH
PRESSURE BUILDS IN FROM THE WEST LATE THIS AFTERNOON AND ALLOWS
WINDS AND WAVES TO RELAX. A FAST MOVING LOW PRESSURE SYSTEM WILL
THEN TRAVERSE THE REGION ON THURSDAY. THE GRADIENT WILL NOT BE TOO
TERRIBLE STRONG...BUT COULD LEAD TO SOME GUSTS UP TO 25 KNOTS OVER
LAKES ST CLAIR...ERIE AND THE SOUTHERN BASIN OF LAKE HURON.
&&
.AVIATION...ISSUED 1159 PM EDT TUE APR 23 2013
//DISCUSSION...
A COLD FRONT WILL SHIFT THROUGH THE REMAINDER OF THE TERMINALS
BETWEEN 06Z-08Z...BRINGING MVFR TO OCCASIONAL IFR CIGS OVERNIGHT.
RAIN SHOWERS WILL CONTINUE AS A WAKE OF LOW PRESSURE LIFTS UP ALONG
THIS FRONTAL BOUNDARY. AS COLDER AIR WORKS INTO THE AREA IN THE WAKE
OF THIS FRONT...SOME SNOWFLAKES MAY MIX IN WITH THE SHOWERS AND WILL
INCLUDE THIS MENTION AT KMBS...WHERE IT IS MOST LIKELY TO OCCUR.
DRIER AIR WILL WORK INTO THE AREA AS NORTHWEST FLOW DEVELOPS...SO
CIGS WILL IMPROVE TO LOWER VFR ON WEDNESDAY...EVEN AS A SECOND WAVE
BRINGS ADDITIONAL SHOWERS TO PARTS OF THE AREA INTO MIDDAY. VFR
CONDTIONS ARE THEN EXPECTED AS SKIES SCATTERED OUT LATE IN THE DAY.
FOR DTW...WINDS WILL SHIFT TO THE NORTHWEST BY 08Z WITH THE PASSAGE
OF A COLD FRONT. RAIN SHOWERS WILL PERSIST WITH CIGS LOWERING TO
MVFR TO OCCASIONAL IFR ALONG/BEHIND THIS FRONTAL BOUNDARY.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FT THROUGH 20Z WEDNESDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...FLOOD WATCH...MIZ047-MIZ048-MIZ049-MIZ053-MIZ054-MIZ055-MIZ060-
MIZ061-MIZ062...UNTIL 8 AM WEDNESDAY.
LAKE HURON...
SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT
HURON...UNTIL 5 PM WEDNESDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...SC
LONG TERM....HLO
MARINE.......SC
AVIATION.....DG
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
313 AM CDT WED APR 24 2013
.SHORT TERM...(THROUGH LATE THIS AFTERNOON)
ISSUED AT 312 AM CDT WED APR 24 2013
(TODAY)
STILL DEALING WITH SHOWERS AND ISOLATED THUNDERSTORMS IN THE FAR
SOUTHEASTERN PORTIONS OF FORECAST AREA THIS MORNING. BUT THIS
ACTIVITY TO CONTINUE TO TAPER OFF. IN THE MEANTIME...DEF ZONE BAND
OF VERY LIGHT SNOW/RAIN CONTINUES TO TRACK TO THE EAST SOUTHEAST
ACROSS NORTHERN PORTIONS OF FORECAST AREA EARLY THIS MORNING.
EXPECT THE LIGHT SNOW/RAIN TO BE BRIEF AS IT SLIDES THROUGH REGION
THIS MORNING...COMING TO AN END BY NOON AS SECONDARY SHORTWAVE LIFTS
OUT. BECAUSE OF THE WARM GROUND AND LIGHT NATURE OF THE PCPN...DO
NOT EXPECT ANY ACCUMULATION WITH THIS DEF ZONE PCPN. OTHERWISE...
BACK EDGE OF CLOUDS WITH THIS SYSTEM ARE ALREADY MOVING INTO
NORTHWESTERN MO...SO TO CONTINUE MAKING STEADY PROGRESS AS WELL WITH
CLEARING CONDITIONS REACHING METRO AREA BY EARLY THIS AFTERNOON.
HIGHS WILL BE ABOUT 15 DEGREES BELOW NORMAL...IN THE LOW TO MID 50S.
WINDS TO PERSIST FROM THE NORTHWEST AROUND 10 MPH.
BYRD
TRUETT
.LONG TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 312 AM CDT WED APR 24 2013
(TONIGHT-THURSDAY)
00Z RUNS CONTINE TO ADVERTISE A SECONDARY SHORTWAVE DIPPING INTO
LONG WAVE TROF OVER THE CENTRAL U.S. TONIGHT. MAIN DYNAMICS WITH
THIS SYSTEM WILL BE TO OUR N...OVER THE UPPER MISSISSIPPI VALLEY AND
INTO THE UPPER GREAT LAKES...SO NOT FORESEEING MUCH IN THE WAY OF
PRECIP IN OUR AREA.
COLD FRONT ASSOCIATED WITH THIS FEATURE WILL PRODUCE A VERY BRIEF
REINFORCING SHOT OF COLD AIR ACROSS NORTHERN PARTS OF THE FA LATE
TONIGHT AND EARLY THURSDAY. EARLIER THERE WAS SOME CONCERN THAT
FROST MAY BE A PROBLEM WITH THE EXPANSIVE SURFACE RIDGE SOUTH OF THE
COLD FRONT...BUT IT NOW APPEARS THAT COLD FRONT WILL PENETRATE FAR
ENOUGH SOUTH THAT THE MIXING ASSOCIATED WITH IT SHOULD PREVENT FROST
IN ALL BUT PERHAPS THE MOST SHELTERED AREAS IN S SECTIONS OF THE
CWA. WILL KEEP SOME MENTION OF FROST GOING IN OUR FAR SOUTH...BUT
NO HEADLINE ATTM.
UA PATTERN OVER THE REGION QUICKLY TRANSITIONS TO A ZONAL FLOW
REGIME ON THURSAY IN THE WAKE OF THE UPPER GREAT LAKES SHORTWAVE.
THIS SHOULD ALLOW FOR SOME MODERATION TEMPS DURING THE
DAY...ALTHOUGH HIGHS WILL STILL REMAIN NEARLY 10 DEGREES BELOW
NORMAL.
(FRIDAY-SATURDAY)
MEDIUM RANGE SOLUTIONS ARE STILL BRINGING REMNANTS OF SW CUTOFF LOW
INTO THE AREA ON FRIDAY AND FRIDAY NIGHT. GFS IS THE ODD-MODEL OUT
WITH A MORE NWD PLACEMENT OF FEATURES AND QPF...SO HAVE BASED
FORECAST ON THE MORE SOUTHWARD CONSENSUS SOLUTIONS WHICH DOVETAILS
NICELY WITH GOING FORECASTS. PRECIP MAY HAVE A TOUGH TIME REACHING
N SECTIONS OF OUR CWA AND HAVE TRIMMED POPS BACK IN THE N A BIT ON
FRIDAY...BUT BROAD AREA OF OVERRUNNING SHOULD MAKE FOR A RAINY AND
COOL DAY OVER MUCH OF S MO. SOME OF THIS PRECIP SHOULD CERTAINLY
CONTINUE INTO FRIDAY NIGHT...WITH A THREAT OF LIGHT RAIN LINGERING
OVER S SECTIONS OF THE CWA INTO SATURDAY AS LINGERING REMNANTS OF
SYSTEM BEGIN TO SAG SOUTH.
(SUNDAY-WEDNESDAY)
HEIGHTS ARE FORECAST TO BUILD OVER AREA AS UPPER TROF SLOWLY DEEPENS
OVER THE NORTHERN ROCKIES. THIS SHOULD CERTAINLY LEAD TO A WARMUP
DURING THE EARLY PART OF THE NEW WEEK WITH TEMPERATURES FINALLY
REBOUNDING TO NEAR..AND PERHAPS ABOVE...AVERAGE LEVELS. DETAILS IN
SYNOPTIC FEATURES GET FAIRLY MUDDLED BY MID WEEK AS THE OPERATIONAL
GFS IS MUCH MORE PROGRESSIVE WITH THE UPPER TROF THAN THE ECMWF.
DUE TO THE DISCREPENCY FOR NOW HAVE KEPT POPS BELOW CHANCE CATEGORY
ON WEDNESDAY.
TRUETT
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1132 PM CDT TUE APR 23 2013
RAIN SHOWERS CONTINUE TO PUSH SLOWLY OFF TO THE EAST LATE THIS
EVENING WELL BEHIND COLD FRONT WHICH PASSED THROUGH THE AREA
TODAY. SHOWERS SHOULD PUSH OUT OF KSUS AND KSTL BY 0600 UTC BUT
STILL AFFECT KCPS THROUGH APPROXIMATELY 0900 UTC. FUTHER TO THE
NORTHWEST...A NARROW BAND OF RAIN/SNOW MIX IS SWEEPING TO THE
EAST-SOUTHEAST AND HAVE A TEMPO GROUP IN AT KCOU AND KUIN
OVERNIGHT TO ACCOUNT FOR A 2-3 HOUR PERIOD OF LIGHT MIXED
PRECIPITATION ACCOMPANIED BY MVFR CEILINGS. NOT SURE HOW WELL
CURRENT BAND WILL HOLD TOGETHER NOR THE PYTPE ACROSS METRO TAF
SITES IF IT DOES INDEED ARRIVE...SO FOR NOW LEFT OUT OF TAFS.
CEILINGS HAVE ACTUALLY IMPROVED THE PAST SEVERAL HOURS AND ONLY
REAL GUIDANCE WHICH HAS LATCHED ON IS RAP SO TRIED TO FOLLOW ITS
TRENDS FAIRLY CLOSELY. KCOU AND KUIN HAVE ALREADY IMPROVED TO VFR
AND BELIEVE THEY WILL STAY THAT WAY WITH THE EXCEPTION OF WITHIN
THE AFOREMENTIONED BAND OF RAIN/SNOW. FOR THE METRO TAFS...MVFR
CEILINGS WILL LIKELY PREVAIL OVERNIGHT BEFORE IMPROVING TO VFR
EARLY TOMORROW MORNING THOUGH THIS MAY STILL YET BE TOO
SLOW. WINDS WILL GRADUALLY BACK THROUGH THE VALID TAF PERIOD AS SFC
HIGH PRESSURE SLIDES INTO THE CENTER OF THE COUNTRY.
SPECIFICS FOR KSTL...
RAIN SHOWERS CONTINUE TO PUSH SLOWLY OFF TO THE EAST LATE THIS
EVENING WELL BEHIND COLD FRONT WHICH PASSED THROUGH THE AREA
TODAY. SHOWERS SHOULD PUSH OUT OF KSTL BY 0600 UTC. FUTHER TO THE
NORTHWEST...A NARROW BAND OF RAIN/SNOW MIX IS SWEEPING TO THE
EAST-SOUTHEAST. NOT SURE HOW WELL CURRENT BAND WILL HOLD TOGETHER
NOR THE PYTPE FOR LAMBERT IF IT DOES INDEED ARRIVE...SO
FOR NOW LEFT OUT OF TAF DUE TO LOW CONFIDENCE. CEILINGS HAVE ACTUALLY
IMPROVED THE PAST SEVERAL HOURS TO THE NORTH AND WEST AND ONLY
REAL GUIDANCE WHICH HAS LATCHED ON IS RAP SO TRIED TO FOLLOW ITS
TRENDS FAIRLY CLOSELY. THAT BEING SAID...MVFR CEILINGS WILL
PROBABLY PREVAIL OVERNIGHT BEFORE IMPROVING TO VFR EARLY TOMORROW
MORNING THOUGH THIS MAY STILL YET BE TOO SLOW. WINDS WILL GRADUALLY
BACK THROUGH THE VALID TAF PERIOD AS SFC HIGH PRESSURE SLIDES INTO
THE CENTER OF THE COUNTRY.
GOSSELIN
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1143 PM CDT TUE APR 23 2013
.SHORT TERM...(THROUGH LATE TONIGHT)
ISSUED AT 325 PM CDT TUE APR 23 2013
A STRONG CDFNT CONTINUES TO PUSH THROUGH THE CWA THIS AFTN ALTHOUGH
ITS SEWD PROGRESS HAS BEEN TEMPORARILY STALLED BY AN AREA OF LOW
PRESSURE IN SWRN MO WHICH IS RIDING UP THE BDRY TOWARDS IL. WINDS
WILL ABRUPTLY BECOME NWLY TO NLY AFTER FROPA AND TEMPERATURES WILL
QUICKLY FALL INTO THE 40S AND UPPER 30S. ON-AND-OFF SHRA WILL
CONTINUE INTO THE EARLY EVENING HOURS FOLLOWED BY ANOTHER PD OF
STEADIER PCPN ONCE A DEFORMATION ZONE REDEVELOPS ACROSS THE AREA.
MODEL FCSTS OF H7-H6 FRONTOGENESIS SEEM WELL CORRELATED WITH THE
LARGE DEFORMATION ZONE THAT DVLPD OVER KS AND NWRN MO EARLIER TODAY
THEREFORE GENERALLY FOLLOWED THIS GUIDANCE IN PLACING HIGHEST PCPN
CHCS FOR TONIGHT. THE AIR MASS BEHIND THE FRONT IS COLD ENOUGH THAT
SOME LIGHT SNOW MAY MIX IN WITH THE RAIN LATER TONIGHT HOWEVER NO
ACCUMULATIONS ARE EXPECTED DUE TO THE WARM GROUND.
KANOFSKY
.LONG TERM...(WEDNESDAY THROUGH NEXT TUESDAY)
ISSUED AT 325 PM CDT TUE APR 23 2013
(WEDNESDAY - WEDNESDAY NIGHT)
UPPER LEVEL LONGWAVE TROF OVER THE CNTRL-ERN CONUS WILL REMAIN IN
PLACE DURING THIS PERIOD...A PATTERN THAT ALLUDES TO CONTINUED COOL.
MODELS HAVE CERTAINLY COME MORE ON BOARD AND IN BETTER CONSENSUS
DURING THE PAST 12-24HRS WITH REGARDS TO DEVELOPMENT OF A SECOND
DEFORMATION ZONE WITH OUR CURRENT SYSTEM THEREFORE DELAYING THE
FINAL EXIT OF THE PCPN INTO WEDNESDAY MORNING. A MORE CYCLONICLY
CURVED H300 JET...A STRONG FINAL VORT MAX AT THE BASE OF THE
TROF...WITH REASONABLY STRONG FRONTOGENESIS AND JUST ENOUGH MOISTURE
LEFT THANKS TO A SLOWER PROGRESSING H850 FRONT ALOFT ARE THE REASONS
FOR THIS SECONDARY AREA. WHILE ALL OF THIS IS EXPECTED TO BE IN
PLACE AND WORTHY OF LIKELY POPS AT 12Z/WED...SUDDEN SURGE OF DRY AIR
AND LOSS OF FORCING BY 18Z/WED WILL WRAP UP PCPN QUICKLY WED MRNG.
PCPN TYPES STILL LOOK LIKE A RAIN-SNOW MIX ON THE NWRN EDGE...INCL
THRU THE STL METRO AREA...BUT SFC TEMPS WILL BE ENOUGH ON THE FENCE
TO FAVOR ALL RAIN SHORTLY AFTER 12Z. NO SNOW ACCUM IS EXPECTED.
MOS TEMPS FOR MAXES LOOK GOOD ON WEDNESDAY...WHILE SFC RIDGE AXIS
DROPPING INTO SRN MO AND FAR SRN IL FOR WEDNESDAY NIGHT WILL LEAD TO
A PREFERENCE FOR THE WARMER MAV NUMBERS FOR MIN TEMPS OVER NRN MO
AND CNTRL IL...TRENDING TOWARDS THE COLDER MET MOS IN SERN MO. MIN
TEMPS IN SERN MO SHOULD BE CLOSE TO FREEZING...BUT NOT ENOUGH BELOW
TO WARRANT FREEZE WARNING...BUT COULD VERY WELL SEE A FROST ADVISORY
ACROSS A LARGE PART OF THE AREA S OF I-70...PERHAPS FURTHER N AS
WELL...WITH CLEAR SKIES AND LIGHT WINDS EXPECTED. WILL MAINTAIN
PATCHY FROST IN THESE AREAS FOR NOW. ELSEWHERE FURTHER N...TEMPS
LOOK TOO MARGINAL AND SFC WNDS A BIT TOO STRONG FOR FROST.
(THURSDAY - NEXT TUESDAY)
UPPER LEVEL LONGWAVE TROF IS ANTICIPATED TO RETREAT NWD LATE THIS
WEEK AND EVENTUALLY GET REPLACED EARLY NEXT WEEK BY A LONGWAVE RIDGE
OVER ERN NOAM WITH A TROF IN THE W. THIS IS QUITE A PATTERN SHIFT
TO WHAT WE HAD BEEN SEEING...AND THIS SHOULD GIVE US ABOVE AVERAGE
TEMPS FROM LATE THIS WEEKEND THRU THE END OF THE FCST...BUT THE
RIDGING SHOULD ALSO BE SUFFICIENTLY STRONG TO DEFLECT SYSTEMS TO OUR
N KEEPING PCPN CHCS LO.
MODELS CONTINUE TO FORM A CONSENSUS ON TIMING OF A SHORTWAVE THRU
LATE IN THE WEEK OUT OF THE SWRN CONUS...A FORMER CUTOFF LO
REJOINING THE MAIN FLOW...WITH THE ECMWF SPEEDING UP TO A TIMING
CLOSER TO THE GFS FROM 24HRS AGO. DECENT RAIN CHCS WILL THUS MAKE A
RETURN TO THE REGION DURING THE FRIDAY-FRIDAY NIGHT TIMEFRAME WITH
PERHAPS SOMETHING LINGERING INTO SATURDAY. THUNDER IS LOOKING LIKE
LESS AND LESS OF A POSSIBILITY WITH EACH RUN...KEEPING THE MAIN
SYSTEM TO OUR S AND SEVERELY LIMITING THE BETTER SHOWALTER/MUCAPE
VALUES TO THE FAR SRN FA.
WITH THE LONGWAVE RIDGE BUILDING OVER THE ERN CONUS...SHOULD SEE
ABOUT THE HIGHEST HEIGHT VALUES OF THE SEASON AND A PERIOD OF DRY
WX. STILL SOME DISAGREEMENT ON WHETHER OR NOT A SFC CDFNT WILL COME
DOWN ON TUESDAY...BUT WITH THAT KIND OF MID LEVEL FLOW AND THE GFS
ALREADY BACKING OFF ON THE TIMING BY 12HRS...FEEL IT WILL PROBABLY
NOT HAPPEN AS QUICKLY AS IT SAYS.
TES
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1132 PM CDT TUE APR 23 2013
RAIN SHOWERS CONTINUE TO PUSH SLOWLY OFF TO THE EAST LATE THIS
EVENING WELL BEHIND COLD FRONT WHICH PASSED THROUGH THE AREA
TODAY. SHOWERS SHOULD PUSH OUT OF KSUS AND KSTL BY 0600 UTC BUT
STILL AFFECT KCPS THROUGH APPROXIMATELY 0900 UTC. FUTHER TO THE
NORTHWEST...A NARROW BAND OF RAIN/SNOW MIX IS SWEEPING TO THE
EAST-SOUTHEAST AND HAVE A TEMPO GROUP IN AT KCOU AND KUIN
OVERNIGHT TO ACCOUNT FOR A 2-3 HOUR PERIOD OF LIGHT MIXED
PRECIPITATION ACCOMPANIED BY MVFR CEILINGS. NOT SURE HOW WELL
CURRENT BAND WILL HOLD TOGETHER NOR THE PYTPE ACROSS METRO TAF
SITES IF IT DOES INDEED ARRIVE...SO FOR NOW LEFT OUT OF TAFS.
CEILINGS HAVE ACTUALLY IMPROVED THE PAST SEVERAL HOURS AND ONLY
REAL GUIDANCE WHICH HAS LATCHED ON IS RAP SO TRIED TO FOLLOW ITS
TRENDS FAIRLY CLOSELY. KCOU AND KUIN HAVE ALREADY IMPROVED TO VFR
AND BELIEVE THEY WILL STAY THAT WAY WITH THE EXCEPTION OF WITHIN
THE AFOREMENTIONED BAND OF RAIN/SNOW. FOR THE METRO TAFS...MVFR
CEILINGS WILL LIKELY PREVAIL OVERNIGHT BEFORE IMPROVING TO VFR
EARLY TOMORROW MORNING THOUGH THIS MAY STILL YET BE TOO
SLOW. WINDS WILL GRADUALLY BACK THROUGH THE VALID TAF PERIOD AS SFC
HIGH PRESSURE SLIDES INTO THE CENTER OF THE COUNTRY.
SPECIFICS FOR KSTL...
RAIN SHOWERS CONTINUE TO PUSH SLOWLY OFF TO THE EAST LATE THIS
EVENING WELL BEHIND COLD FRONT WHICH PASSED THROUGH THE AREA
TODAY. SHOWERS SHOULD PUSH OUT OF KSTL BY 0600 UTC. FUTHER TO THE
NORTHWEST...A NARROW BAND OF RAIN/SNOW MIX IS SWEEPING TO THE
EAST-SOUTHEAST. NOT SURE HOW WELL CURRENT BAND WILL HOLD TOGETHER
NOR THE PYTPE FOR LAMBERT IF IT DOES INDEED ARRIVE...SO
FOR NOW LEFT OUT OF TAF DUE TO LOW CONFIDENCE. CEILINGS HAVE ACTUALLY
IMPROVED THE PAST SEVERAL HOURS TO THE NORTH AND WEST AND ONLY
REAL GUIDANCE WHICH HAS LATCHED ON IS RAP SO TRIED TO FOLLOW ITS
TRENDS FAIRLY CLOSELY. THAT BEING SAID...MVFR CEILINGS WILL
PROBABLY PREVAIL OVERNIGHT BEFORE IMPROVING TO VFR EARLY TOMORROW
MORNING THOUGH THIS MAY STILL YET BE TOO SLOW. WINDS WILL GRADUALLY
BACK THROUGH THE VALID TAF PERIOD AS SFC HIGH PRESSURE SLIDES INTO
THE CENTER OF THE COUNTRY.
GOSSELIN
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
439 AM EDT WED APR 24 2013
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TODAY AS A STRONG COLD
FRONT PASSES ACROSS THE AREA. BEHIND THIS FEATURE...DRY
CONDITIONS ARE EXPECTED ON THURSDAY WITH THE NEXT ROUND OF
SHOWERS POSSIBLE THURSDAY NIGHT AND EARLY FRIDAY AS ANOTHER WEAK
WAVE WILL PASSES OVERHEAD. FAIR AND PLEASANT CONDITIONS ARE THEN
EXPECTED FOR THE WEEKEND AS STRONG HIGH PRESSURE BUILDS INTO THE
AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
A CHALLENGING FCST TO SAY THE LEAST TODAY AS A STRONG COLD FRONT
WILL PLOW THROUGH THE REGION DURING THE LATE AFTERNOON AND EARLY
EVENING HRS. THE MAIN DIFFICULTIES ARE TWOFOLD WITH THE FIRST
BEING THE DEGREE OF WARMING PROCEEDING THE FRONT...AND THE SECOND
CONCERNING SEVERE WX POTENTIAL AS THE FRONT BARRELS THROUGH THE
REGION. FIRST THINGS FIRST HOWEVER AND WE SHOULD PROBABLY START
WITH A GENERAL SYNOPTIC OVERVIEW.
EARLY MORNING WATER VAPOR CLEARLY SHOWING A DEEP TROUGH OF LOW
PRESSURE DIGGING ACROSS THE SOUTHERN PLAINS THIS MORNING WITH
BROAD CYCLONIC FLOW PREVAILING OVER THE NATION/S MIDSECTION.
ACROSS OUR REGION...WEAK UPPER RIDGING THAT BROUGHT SUCH NICE
WX TO OUR AREA YESTERDAY NOW DEPARTING TO OUR EAST AS UPPER TROUGH
AND ASSOCIATED DEFORMATION AXIS WITH THE WESTERN ATLANTIC COASTAL
LOW WORK OFF THE NEW ENGLAND COAST. WITH TIME TODAY...COLD FRONT
ASSOCIATED WITH THE CENTRAL US TROUGH WILL ADVANCE EAST OVER OUR
REGION BY THIS AFTERNOON BRINGING WITH IT A PERIOD OF SHWRS AND
STORMS TO MUCH OF OUR AREA.
AS FOR THE SEVERE WX POTENTIAL...MODELS REMAIN ALL OVER THE PLACE
WITH RESPECT TO THE DEGREE OF DESTABILIZATION THAT WILL OCCUR
PRIOR TO FROPA LATER TODAY. THE NAM REMAINS THE MOST UNSTABLE
SOLUTION THIS MORNING WITH AWIPS PLAN VIEW MAPS SHOWING A NARROW
CORRIDOR OF MLCAPE VALUES RANGING FROM 400-500 J/KG IMMEDIATELY
PROCEEDING THE FRONT MAINLY WEST OF THE I-81 CORRIDOR. THIS IS
PERPLEXING TO SOME DEGREE AS CORRESPONDING NAM BUFKIT SOUNDINGS
FOR ELM AND OTHER WESTERN FCST POINT LOCATIONS ADVERTISE MUCH
LOWER VALUES. THE GFS SEEMS TO AGREE WITH THE WEAKER NAM BUFKIT
SOLUTIONS...AS DOES THE LATEST RUC AND LOCALLY RUN WRF MODELS. AS
FOR THE KINEMATICS...WIND FIELDS ALOFT REMAIN IMPRESSIVELY STRONG
WITH 0-6 KM BULK SHEAR VECTORS RANGING FROM 40 TO 50 KTS ACROSS
THE REGION WHILE 0-3 KM BULK SHEAR VALUES ARE JUST AS HIGH. THIS
SUGGESTS THAT IF SEVERE WX WERE TO DEVELOP...DAMAGING WIND GUSTS
WOULD BE THE BIGGEST THREATS IF ANY DEVELOPING CONVECTION WERE TO
MORPH INTO A WELL-DEFINED SQUALL LINE OR SHORT BOWING SEGMENTS. THIS
AGREES WELL WITH LOCAL SEVERE WX CHECKLIST WHICH SUGGEST A
SIGNIFICANT COOL SEASON WIND EVENT IS POSSIBLE HOWEVER ITS HARD TO
GET BY LATEST MODEL TRENDS OF VERY MODEST DESTABILIZATION.
CONSIDERING THE AMOUNT OF CLOUD COVER THAT WILL LIKELY BEGIN
MOVING OVERHEAD THIS MORNING COUPLED WITH THE FACT THAT RETURN
FLOW MOISTURE WILL BE MEAGER AT BEST (AFTERNOON DEWPOINT TEMPS
ONLY CLIMBING INTO THE MIDDLE TO UPPER 40S)...WE/RE INCLINED TO
BELIEVE THAT SEVERE WX POTENTIAL WILL BE FAIRLY LIMITED. THIS
AGREES WELL WITH THE LATEST SPC DAY 1 OUTLOOK WHICH ONLY
ADVERTISES GENERAL THUNDER MENTION ACROSS OUR REGION ("SEE TEXT" TO
OUR SOUTHWEST). ALTHOUGH WE TOTALLY CANNOT RULE OUT SEVERE WX
LATER TODAY...WE DO NOT THINK THAT THE FCST REGION WILL BE DEALING
WITH A WIDESPREAD SEVERE WX EVENT AT THIS TIME.
NOW TO THE NEXT ISSUE...THE HIGH TEMP FCST FOR TODAY. UPSTREAM OBS
FROM THE UPPER OHIO VLY SHOW TEMPS IN THE LOWER 60S AS CLOSE AS
CLEVELAND EARLY THIS MORNING. CONSIDERING THIS AIR WILL TRAVEL
EAST OVER OUR REGION...WE/RE INCLINED TO BELIEVE TEMPS WILL WARM
INTO THE UPPER 60S TO LOWER 70S AHEAD OF THE FRONT TODAY. ONLY
ITEM OF CONCERN IS THE LATEST SATELLITE TRENDS WHICH SHOW ENHANCED
CLOUD COVER APPROACHING FROM NORTHERN OHIO THIS MORNING. DESPITE
THIS HOWEVER...DEGREE OF THERMAL ADVECTION WILL LIKELY BE ENOUGH
TO OVERCOME LIMITED COOLING ASSOCIATED WITH INCREASING CLOUDS
ALOFT.
BY TONIGHT...COLD FRONT TO EXIT OFF TO THE EAST WITH TIME BETWEEN
00 AND 06Z. RAIN SHOULD GRADUALLY COME TO AN END WITH TIME WITH
STRONG COLD AIR ADVECTION EXPECTED IN ITS WAKE. AS A
RESULT...TEMPS WILL DROP INTO THE LOWER TO MIDDLE 30S ACROSS MUCH
OF THE REGION WITH GUSTY WINDS EXPECTED THROUGH A GOOD PORTION OF
THE OVERNIGHT HRS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
COOLER TEMPS EXPECTED BOTH THU AND FRI AS COOL HIGH PRESSURE
BUILDS IN FOLLOWING FROPA LATER TONIGHT. WITH H85 TEMPS QUICKLY
FALLING TO NEAR ZERO CELSIUS...HIGH TEMPS ON THU ONLY LOOK TO
WARM INTO THE LOWER TO MIDDLE 50S AT BEST. SLIGHTLY WARMER TEMPS
EXPECTED ON FRI AS HIGH PRESSURE ADVANCES TO THE EAST WITH UPPER
50S TO LOWER 60S AGAIN POSSIBLE. WEAK UPPER WAVE WILL PASS ACROSS
THE REGION THU NGT/EARLY FRI BRINGING THE NEXT ROUND OF SHWRS TO
THE AREA.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
300 PM UPDATE...
SHAPING UP TO BE A BEAUTIFUL EXTENDED PERIOD WITH HIGH PRESSURE
CENTERED OVER US TO START THE PERIOD THEN SHIFTING EAST BUT STILL
IN CONTROL THROUGH EARLY NEXT WEEK. THE PATTERN IS RATHER STAGNANT
SO WHILE WE WILL SEE TEMPS WARM INTO THE 60S DURING THIS
TIME...THE TRUE STRONG WAA AND ASSOCIATED VERY WARM AIR WILL
REMAIN WELL TO OUR WEST. SOME UNCERTAINTY DOES CREEP IN FROM
SUNDAY NIGHT AND BEYOND AS BOTH THE EURO AND GFS SHOW AN AXIS OF
MOISTURE JUST TO OUR WEST THROUGH THE OHIO VALLEY. THE GFS HINTS
THAT WE MAY SEE SOME SHOWERS ESPECIALLY OVER THE FAR WESTERN
FINGER LAKES DURING THIS TIME WHILE THE EURO IS MUCH DRIER.
SOMETHING TO WATCH CAREFULLY BUT FOR NOW WILL KEEP MOST OF THE
AREA DRY.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
GNRL VFR CONDS WILL CONT TNGT AND MUCH OF WED. ONLY XCPTN IS THE
MARINE LYR CLDS THAT MAY BRING AN OCNL MVFR CIG TO AVP OVRNGT.
OTRW...STRONG FNT MVES INTO THE AREA BEGINNING ARND 21Z WITH A
GOOD CHANCE OF CONV WITH MVFR CIGS AND VSBYS IN BRIEF HEAVY RAIN.
WINDS SHD BE QUITE GUSTY INVOF OF THE FNT...WITH A SWITCH TO THE
WEST AFTER PASSAGE. BHD THE FNT...CAA SC WILL KEEP CIGS IN THE
MVFR RANGE THRU THE END OF THE PD.
OUTLOOK...
WED NGT...MVFR IN SHRA.
THU THRU SUN...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG
NEAR TERM...CMG
SHORT TERM...CMG
LONG TERM...HEDEN
AVIATION...DGM/DJN
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1147 PM CDT TUE APR 23 2013
.UPDATE...
ISSUED AT 1147 PM CDT TUE APR 23 2013
CONTINUED TREND OF SLOWING DOWN POPS MOVING INTO THE FAR WESTERN
CWA DURING THE EARLY MORNING HOURS AND THEN THROUGH THE REST OF
THE CWA DURING THE DAY TOMORROW. THE MODELS STILL SHOWING A LOT OF
VARIATION IN THE EXACT PLACEMENT OF QPF BUT SEEM TO BE A BIT
BETTER ON THE GENERAL TREND OF THE BEST PRECIP IN THE EASTERN
COUNTIES DURING THE AFTERNOON AS THE MAIN UPPER WAVE DIGS DOWN
INTO THE AREA. WILL CONTINUE TO KEEP LIKELY POPS IN THAT AREA
DURING THE AFTERNOON. ANY AMOUNTS SHOULD REMAIN AROUND AN INCH OR
LESS ON GRASSY AREAS.
UPDATE ISSUED AT 1013 PM CDT TUE APR 23 2013
MAIN CHANGE WAS TO SLOW DOWN THE PROGRESSION OF PRECIP INTO THE
AREA TONIGHT AND TOMORROW...AS THE RAP AND NAM ARE BACKING OFF ON
PRECIP AND ONLY A TINY AMOUNT IS FALLING IN THE WEST SO FAR. THINK
THAT PRECIP WILL BE MOSTLY AFTER SUNRISE TOMORROW AND ANYTHING
SHOULD BE PRETTY LIGHT.
UPDATE ISSUED AT 701 PM CDT TUE APR 23 2013
LOWERED CLOUD COVER A BIT THIS EVENING AS IT SEEMS MOST OF THE
BEST COVERAGE WILL HOLD OFF UNTIL AFTER MIDNIGHT AS THE SHORTWAVE
IN CANADA APPROACHES. NO OTHER CHANGES.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 344 PM CDT TUE APR 23 2013
SEEMS LIKE THE MOST CUMULUS DEVELOPMENT TODAY WAS JUST TO THE EAST
OF THE RED RIVER VALLEY. OTHERWISE THERE ARE SOME HIGH LEVEL CLOUDS
STREAMING INTO THE WESTERN FA. GENERALLY EXPECT CLOUDS TO INCREASE
TONIGHT BUT IT MAY TAKE LONGER FOR THEM TO REACH THE EAST AND
SOUTHEAST FA. THE NEXT UPSTREAM WAVE IS CURRENTLY OVER NORTHEAST
ALBERTA AND IS FORECAST TO DROP INTO THE FA LATE TONIGHT. WENT AHEAD
AND INCREASED PCPN CHANCES INTO THE LIKELY RANGE IN THE NORTHWEST FA
TOWARD WED MORNING. LOOKS LIKE THIS WILL BE A HIGH POP/LOW QPF EVENT
OVERALL.
THE SFC REFLECTION OF THE ABOVE MENTIONED WAVE WILL BE A COLD FRONT
THAT DROPS INTO THE NORTHWEST FA BY WED MORNING. AS THIS FEATURE
DROPS THRU THE FA DURING THE DAY EXPECT THE BEST CHANCES FOR PCPN TO
BE ACROSS THE NORTH AND NORTHEAST. HOWEVER THERE SHOULD BE SOME
LIGHT SNOW JUST ABOUT EVERYWHERE. AS IN THE PAST FEW EVENTS IT
SHOULD MELT ON THE ROADS AND JUST STAY WET DURING THE DAYTIME HOURS
WITH THE ONLY ACCUMULATION IN GRASSY/SNOW COVERED AREAS. WPC
SNOWFALL GRAPHIC SHOWING THE POSSIBILITY FOR AN INCH OR SO OF SNOW
ALONG AND NORTH OF THE HIGHWAY 2 CORRIDOR AND THAT SEEMS REASONABLE.
SREF PCPN TYPE SEEMS PRETTY WELL PEGGED ON JUST SNOW AND WILL GO
WITH THAT IDEA TOO. THINK SOME AFTERNOON TEMPS MAY GET INTO THE
MID 30S BUT THAT WOULD BE ABOUT IT.
BY WED NIGHT THE SYSTEM SHOULD BE PULLING OFF TO THE EAST. LEFT SOME
VERY LOW CHANCES FOR LIGHT SNOW IN THE FAR EAST EARLY. LOWS WILL
PROBABLY DEPEND ON HOW FAST OR IF THE CLOUDS CLEAR OUT. THERE IS
SOME PRETTY STRONG WARM ADVECTION THAT KICKS IN ESPECIALLY ACROSS
THE WEST WHICH MAY LEAD TO INCREASING CLOUDS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 344 PM CDT TUE APR 23 2013
THU-FRI...SOUTH WINDS ON THU WITH THE GOOD WARM ADVECTION SHIFTING
OVER THE FA. LOOKING LIKE 850MB TEMPS SHOULD RISE BACK ABOVE ZERO
BY 00Z FRI. THE WARMER WEATHER CONTINUES TO LOOK ON TRACK INTO FRI
AS WELL. DEGREE OF WARMING MAY DEPEND ON HOW MUCH SFC WIND OCCURS
WITH MODELS SHOWING FAIRLY WEAK WINDS ON FRI.
FRIDAY NIGHT-TUESDAY...ECMWF AND GFS ARE IN GOOD AGREEMENT DEPICTING
ZONAL TO SOUTHWEST FLOW ALOFT INTO SUNDAY...BUT THEN BECOME OUT OF
PHASE FOR MONDAY AND TUESDAY. FOR MONDAY INTO TUESDAY...THE ECMWF IS
MORE AMPLIFIED WITH THE WEST COAST TROUGH/EAST COAST RIDGE COMPARED
TO THE GFS. THE ECMWF SOLUTION WOULD KEEP A SURFACE BOUNDARY ACROSS
THE FA ALONG WITH A MORE PROLONGED PERIOD OF SHOWER AND/OR
THUNDERSTORM CHANCES. THE GFS SOLUTION WOULD LEAD TO ONLY A BRIEF
PERIOD OF SHOWERS AND/OR THUNDERSTORMS (LIKELY ON MONDAY) WITH HIGH
PRESSURE MOVING INTO THE REGION BY MID-WEEK. THESE ARE OBVIOUSLY BIG
DIFFERENCES AND IMPORTANT GIVEN THE STATE OF RIVER FLOODING. GIVEN
THE LOW CONFIDENCE IN ANY ONE PARTICULAR SOLUTION...WILL GO WITH LOW
END RAIN CHANCES. TEMPERATURES WILL BE THE OTHER BIG CHALLENGE. A
MUCH WARMER AIRMASS WILL HAVE BEEN ADVECTED INTO THE REGION AND
EXPECT MORE NEAR NORMAL TEMPERATURES. SNOWPACK WILL DETERMINE HOW
WARM...AND THINK MOST AREAS SHOULD HAVE ENOUGH SNOW MELTED TO
REALIZE WARMER VALUES. THE EXCEPTION WILL BE THE DEVILS LAKE BASIN
WHERE THE SNOW NORMALLY TAKES LONGER TO MELT...AND KEPT MAX TEMPS IN
THE 40S. WILL NOT WORRY ABOUT FOG...BUT THAT COULD AFFECT
TEMPERATURES AS WELL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1147 PM CDT TUE APR 23 2013
VFR CONDITIONS WILL CONTINUE AS ONLY A FEW STRAY CLOUDS IN THE
3500-6000 RANGE PASS OVER THE AREA THIS EVENING. CONDITIONS SHOULD
GO DOWN TO MVFR IN THE WEST BY EARLY MORNING AND AT THE TAF SITES
FURTHER EAST LATER IN THE DAY. BACKED OFF ON VIS A BIT AND KEPT
REDUCTIONS AROUND THE 3-5SM RANGE. WEST TO NORTHWEST WINDS WILL
PICK UP AND GUST TO AROUND 25 KTS AT TIMES DURING THE AFTERNOON.
CONDTIONS SHOULD RETURN TO VFR AND WINDS DECREASE AT THE END OF
THE PERIOD.
&&
.HYDROLOGY...
ISSUED AT 1254 PM CDT TUE APR 23 2013
RIVER FLOOD WARNINGS CONTINUE FOR THE RED RIVER AT WAHPETON/HICKSON/
FARGO...THE SOUTH BRANCH BUFFALO RIVER AT SABIN AND THE BUFFALO
RIVER AT DILWORTH. OVERALL...THE RATE AT WHICH THESE RIVERS ARE
EXPECTED TO RISE THROUGH FRIDAY WAS LOWERED DUE TO COLD TEMPERATURES
LIMITING THE MELT AND THE FORECAST CREST AT WAHPETON WAS LOWERED
HALF A FOOT TO 16.5 FT TO ACCOUNT FOR LESS AVAILABLE OBSERVED RUNOFF
SOUTH OF HWY 210 ACROSS WEST CENTRAL MN.
LOCALIZED SNOWMELT RUNOFF WILL RESULT IN GRADUAL RISES ALONG THE RED
RIVER AT WAHPETON...HICKSON AND FARGO FOR MUCH OF THIS WEEK.
ADDITIONAL RISES ARE ALSO EXPECTED ALONG THE SOUTH BRANCH BUFFALO
RIVER AT SABIN AND THE BUFFALO RIVER AT DILWORTH. VERY COOL LATE
APRIL TEMPERATURES WILL CONTINUE THROUGH THURSDAY WITH DAYTIME HIGHS
IN THE 30S AND LOWER 40S AND NIGHTTIME LOWS IN THE UPPER TEENS AND
20S. THESE TEMPERATURES WILL LIMIT THE DEGREE OF SNOWMELT THROUGH
MUCH OF THE WEEK.
FRIDAY INTO THE WEEKEND...TEMPERATURES ARE EXPECTED TO RISE
SIGNIFICANTLY...WITH HIGHS IN THE LOWER 60S POSSIBLE THIS WEEKEND.
MORNING LOWS ARE ALSO EXPECTED TO RISE ABOVE FREEZING...RESULTING IN
SIGNIFICANT SNOWMELT RUNOFF AND MORE RAPID RISES IN RIVER LEVELS.
WITH NO SIGNIFICANT PRECIPITATION EXPECTED THE NEXT SEVERAL
DAYS...RIVER RISES WILL DEPEND HEAVILY ON THE TEMPERATURE PATTERN
AND RESULTANT SNOWMELT. IN ADDITION...A LATE PROLONGED SNOWMELT HAS
ALLOWED SOME OF THE EARLIER MELT WATER TO INFILTRATE THE SOIL. EXACT
AMOUNTS ARE UNCERTAIN AT THIS TIME AND THIS UNCERTAINTY IS REFLECTED
IN A RANGE OF CRESTS FOR THE RED RIVER AT WAHPETON. THUS...FORECAST
RIVER LEVELS FOR THIS WEEKEND ARE SUBJECT TO FURTHER REVISIONS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...GODON
LONG TERM...TG
AVIATION...JR
HYDROLOGY...ROGERS
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
532 AM EDT WED APR 24 2013
.SYNOPSIS...
A COLD FRONT WILL SLOWLY CROSS THE WESTERN CAROLINAS AND NORTHEAST
GEORGIA TONIGHT. MILD HIGH PRESSURE WILL THEN BUILD IN BEHIND THE
FRONT FOR THURSDAY AND FRIDAY. A SLOW MOVING AREA OF LOW PRESSURE
WILL DEVELOP OVER THE SOUTHERN PLAINS FRIDAY NIGHT AND DRIFT
NORTHEASTWARD THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 515 AM...THE SKY GRIDS WERE UPDATED TO REFLECT ENCROACHING LOW
STRATUS FROM THE SOUTH. THE 08Z RAP SEEMS TO BE INITIALIZING THE
CLOUDS FAIRLY WELL AND SO IT WAS USED TO REFLECT TRENDS IN THE
CLOUDS THRU MID MORNING. BASICALLY...IT LOOKS LIKE THE CLOUDS WILL
REACH ROUGHLY TO I-85 AROUND OR SHORTLY AFTER DAYBREAK...EXTENDING
NE TOWARD THE TRIAD. FROM THERE IT SHUD DISSIPATE AS INSOLATION
MIXES THE INVERSION/SHALLOW MOISTURE OUT BY MIDDAY.
MEANWHILE...STRATUS DECK (AROUND 5000 FT) CONTINUES TO WORK INTO THE
SW NC MTNS AND NE GA FROM THE WEST. OVERALL...STILL EXPECTING SOME
SUNSHINE BEFORE THICKER CLOUDS FINALLY OVERTAKE THE SKIES BY
MID/LATE AFTN AS A COLD FRONT WORKS INTO THE AREA. NO OTHER CHANGES
WERE MADE.
AS OF 300 AM...A COLD FRONT WAS ANALYZED CROSSING OHIO VALLEY...WITH
CONVECTION INCREASING IN COVERAGE ALONG AND AHEAD OF THE BNDRY.
MODELS ARE IN GOOD AGREEMENT ON UPR LVL FORCING LAGGING BEHIND THE
FRONT TODAY...WITH THE FRONT LOSING ITS PUNCH AS IT ENTERS THE NC
MTNS THIS AFTN. FCST SNDGS ACRS THE PIEDMONT SHOW A SUBSIDENCE
INVERSION THAT IS SLOW TO ERODE THIS AFTN/EVE...RESULTING IN
GENERALLY LESS THAN 500 J/KG OF CAPE. TAKING A BLEND OF THE GFS AND
NAM FOR CAPE...I ONLY GET CHC THUNDER IN THE MTNS WITH NO MENTION
ACRS THE PIEDMONT. OVERALL...A MODEL BLEND OF THE POPS RESULTS IN A
CUT BACK FROM PREV FCST. ALL IN ALL...EXPECTING MAINLY GARDEN
VARIETY SHWRS/TSTMS IN THE MTNS THIS AFTN AND GENERALLY WIDELY SCT
SHWRS ACRS THE ENTIRE AREA THIS EVENING...TAPERING OFF OVERNIGHT
FROM NW TO SE. WITH THE FRONT HAVING AN ANAFRONT STRUCTURE...UPGLIDE
BEHIND THE SFC BNDRY MAY RESULT IN LINGERING SHWRS ALONG AND SOUTH
OF I-85 RIGHT UP TILL DAYBREAK. TEMPS SHUD BE ABLE TO WARM TO ABOVE
NORMAL READINGS EAST OF THE MTNS...AS THICKER CLOUDS AND MOISTURE
DOESN/T ENTER THE AREA TILL AFTER PEAK HEATING. LOWS OVERNIGHT NEAR
NORMAL.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 235 AM EDT WEDNESDAY...THE LATEST NAM AND GFS RUNS CLEAR OUT
CLOUD COVER BY ABOUT MID-MORNING ON THURSDAY. AS I DON/T THINK WE
WILL SEE THAT MUCH PCPN INTO THE PRE-FRONTAL AIRMASS OVER THE
FOOTHILLS AND PIEDMONT...I SUSPECT THAT LOW CLOUDS WON/T BE IN
ABUNDANCE IN THE FIRST PLACE. IT WILL BE A NICE AFTERNOON WITH
CLEAR...BLUE SKIES AND MAX TEMPS A COUPLE CATEGORIES BELOW NORMAL.
FROST STILL APPEARS LIKE A GOOD BET OVER THE NC MTNS AND POSSIBLY
THE WRN FOOTHILLS THURSDAY NIGHT. I/VE INCREASED THE AREAL COVERAGE
OF FROST IN THE WEATHER GRIDS TO ACCOUNT FOR THIS. SOME OF THE
TYPICAL COLD SPOTS AND/OR SHELTERED VALLEYS WILL WILL PROBABLY FALL
TO FREEZING.
FRIDAY WILL ALSO BE A NICE DAY...THOUGH MID AND HIGH LEVEL CLOUD
COVER WILL INCREASE DURING THE AFTERNOON HOURS AHEAD OF A SOUTHERN
STREAM SHORT WAVE. DESPITE THE HIGH CLOUDS...TEMPERATURES SHOULD BE
A FEW DEGREES WARMER THAN THURSDAY/S HIGHS.
FRIDAY NIGHT CLOUDS WILL CONTINUE TO THICKEN AND LOWER AND THERE
WILL BE A CHANCE OF RAIN LATER AT NIGHT...ESPECIALLY OVER THE
MOUNTAINS. THE PCPN WILL BE FORCED AS THE WRN CAROLINAS AND NE GA
WILL BE IN THE RT ENTRANCE REGION OF A 110 KT UPPER JET CENTERED
OVER ERN NC. A SRN STREAM JET MOVING ACROSS THE DEEP SOUTH MAY ALSO
CONTRIBUTE SOME LIFT TO THE SYSTEM. THE SFC COLD FRONT WILL BE WELL
TO OUR SOUTH...DOWN ALONG THE GULF COAST. THEREFORE THE PCPN SHOULD
BE HIGH BASED AND MORE STRATIFORM IN NATURE. ANY STRONG LLVL WARM
ADVECTION STAYS WELL SOUTHWEST OF THE REGION...CLOSER TO THE SFC-H8
FRONT...SO PCPN SHOULD BE LIGHT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM EDT WEDNESDAY...THE LATEST WPC EXTENDED DISCUSSION
FAVORS THE 12 UTC ECMWF FOR THE SAT-TUE PERIOD. LOOKING AT THEIR
EXTENDED RANGE GUIDANCE...THEY HAVE LIKELY POPS ON SATURDAY AND
SOLID CHANCE POPS SUN-TUE.
WHILE THE LATEST GFS IS WEAKER WITH THE FORCING...IT/S STILL IN
PRETTY GOOD AGREEMENT WITH THE 12 UTC RUN OF THE EC IN BRINGING A
SRN STREAM SHORT WAVE SLOWLY ACROSS THE REGION OVER THE WEEKEND.
UPGLIDE WILL INCREASE OVER A LLVL FRONTAL BNDRY...BRINGING PCPN TO
THE REGION. HOWEVER...THERE HAS BEEN A TREND IN THE MODELS TO
DEVELOP THE PCPN FARTHER SOUTH. THIS MAKES A LOT OF SENSE TO ME AS A
BELT OF STRONG MID-TROPOSPHERE FLOW WILL EXIST DOWN TOWARD THE GOM.
THE SFC BNDRY WILL LIKELY HAVE A DIFFICULT TIME LIFTING NORTH OF
THIS BAROCLINIC ZONE ALOFT...AND I CAN SEE QUITE A BIT OF
CONVECTION AND PCPN DEVELOPING DOWN TOWARD THE GULF...ESPECIALLY AS
WE GET INTO SUNDAY.
MONDAY AND TUESDAY THE SRN STREAM IS EVEN STRONGER AND FURTHER SOUTH
AS A MID-LATITUDE H5 RIDGE BEGINS TO DEVELOP OVER THE TN RIVER
VALLEY. THIS BLOCKING RIDGE PROVIDES A BROAD SEPARATION BETWEEN THE
NRN STREAM SHOOTING ACROSS THE NRN PLAINS AND THE SRN STREAM DOWN
ACROSS THE NRN GOM. WHILE WE WOULD CERTAINLY SEE SOME PCPN FROM THIS
PATTERN...I SUSPECT THAT MOST OF THE PCPN INTO MON AND TUE WILL
REMAIN SOUTH OF THE FORECAST AREA. THAT IS IF THIS PARTICULAR
PATTERN DOES EVOLVE. THIS IS NOT A HIGH CONFIDENCE FORECAST...AND
I/M NOT GOING TO DO ANYTHING DRAMATIC TO THE POPS ON THIS SHIFT.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...THE LATEST GUIDANCE IS STARTING TO CATCH ON TO SOME IFR
STRATUS DEVELOPING ACRS CENTRAL/SOUTHERN SC DURING THE WEE MORNING
HOURS...WITH A LIGHT SLY FLOW TAKING THE MOISTURE TOWARD KCLT. STILL
NONE OF THE MODELS ACTUALLY HAVE RESTRICTIONS AT KCLT...SO HAVE NOT
ADDED ANY MENTION WITH THE 06Z TAF. WITH THAT SAID...WILL MONITOR
OBS/SAT CLOSELY...AS STRATUS MAY MAKE A RUN FOR THE TERMINAL AROUND
DAYBREAK. OTHERWISE...VFR WITH A S/SWLY WIND. THE WIND WILL INCREASE
AND BECOME SOMEWHAT GUSTY BY MIDDAY THRU THE AFTN. A COLD FRONT WILL
PUSH INTO THE AREA THIS EVENING...BUT OVERALL MOISTURE WILL BE
LIMITED SUCH THAT TS CHCS TOO LOW TO MENTION IN THE TAF.
ELSEWHERE...ALL GUIDANCE KEEPING VFR CONDITIONS AT ALL TAF SITES
THRU DAYBREAK. HOWEVER...IFR STRATUS IS DEVELOPING TO THE SOUTH AND
MAY APPROACH THE UPSTATE SITES AROUND DAYBREAK. CONFIDENCE TOO LOW
TO ADD MENTION TO THE 06Z TAFS...BUT THE TRENDS WILL BE MONITORED
CLOSELY FOR POSSIBLE AMD. OTHERWISE...EXPECTING VFR CONDITION DURING
THE DAY TODAY WITH INCREASING S/SWLY WINDS AHEAD OF AN APPROACHING
COLD FRONT. MOISTURE WITH THE FRONT IS PROGGED TO ENTER THE KAVL
AREA BY MID AFTN AND ACRS THE REST OF THE TAF SITES LATE
AFTN/EVENING. CONVECTION WITH THE FRONT LOOKS TO BE RATHER STARVED
FOR FORCING/INSTBY...SO CONTINUING WITH JUST PROB30S FOR TS AT ALL
SITES. HIGHEST CHCS WILL BE AT KAVL...AS MOISTURE ENTERS THE MTNS
FROM THE WEST. LLVL MOISTURE/-RA WILL LINGERING BEHIND THE FRONT
LATE THIS EVENING...WHICH MAY RESULT IN SOME RESTRICTIONS. MODELS
ARE MIXED ON HOW MUCH CIG/VSBY RESTRICTIONS WILL EXIST...SO DECIDED
TO KEEP IT VFR FOR NOW.
OUTLOOK...A COLD FRONT WILL CONTINUE TO PUSH THROUGH THE REGION
DURING THE OVERNIGHT HOURS TONIGHT...AND MAY PRODUCE OCCASIONAL CIG
AND VSBY RESTRICTIONS. IMPROVING CONDITIONS ARE EXPECTED ON THURSDAY
AND VFR CONDITIONS EXPECTED THROUGH FRIDAY. THE NEXT SYSTEM WILL
BRING MOISTURE BACK INTO THE AREA FRIDAY NIGHT THRU MOST OF THE
WEEKEND.
CONFIDENCE TABLE...
09-15Z 15-21Z 21-03Z 03-09Z
KCLT HIGH 93% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 89% HIGH 83%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 99% HIGH 100% HIGH 92% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...MCAVOY
NEAR TERM...ARK
SHORT TERM...MCAVOY
LONG TERM...MCAVOY
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1106 PM CDT TUE APR 23 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 254 PM CDT TUE APR 23 2013
CLEAR SKIES ARE EXPECTED TO CONTINUE THROUGH THE EVENING HOURS
TONIGHT AS SURFACE HIGH PRESSURE BUILDS INTO THE AREA. WINDS ON THE
SURFACE WILL TURN WEST TO SOUTHWEST OVERNIGHT...THOUGH THE PRESSURE
GRADIENT DOESN`T BECOME ALL THAT LIGHT. AS SUCH...HAVE NUDGED
FORECAST LOWS UPWARD EVER SO SLIGHTLY...WITH WARMEST READINGS IN
MOST EXPOSED LOCATIONS. NAM FORECAST SOUNDINGS INDICATE POTENTIAL
FOR FOG...BUT THIS IS NOT SUPPORTED BY THE RAP SOUNDINGS. HRRR IS
DOWN FOR MAINTENANCE...BUT IN GENERAL...THINK THE WINDS WILL STAY UP
ENOUGH TONIGHT THAT FOG WILL NOT BE THAT BIG OF A CONCERN.
SHORTWAVE DROPS SOUTHEAST ACROSS THE REGION ON WEDNESDAY. MODELS
SUGGEST THAT SOME OF THE INITIAL DYNAMICS WILL BE LOST TO SATURATING
THE NEAR SURFACE LAYER. TOUGH CALL ON PRECIPITATION TYPE WHICH WILL
BE CONTROLLED BY SURFACE TEMPERATURES AS THIS IS THE ONLY LOCATION
IN THE THERMO PROFILE THAT IS POTENTIALLY ABOVE FREEZING. HAVE A
MIX OF SNOW AND RAIN ALONG THE HIGHWAY 14 CORRIDOR IN THE LAT
MORNING INTO THE EARLY AFTERNOON...BUT IN GENERAL PRECIPITATION
SHOULD PRIMARILY FAVOR RAIN WHICH IS SUPPORTED BY SREF PROFILES.
PROFILES ARE WEAKLY UNSTABLE ALOFT...AND GIVEN THIS IS THE
CASE...THE POTENTIAL EXISTS FOR RAIN OR SNOW SHOWERS TO DEVELOP IN
THE AFTERNOON HOURS. IF THE INTENSITY WAS TO GET STRONG
ENOUGH...THEN MAY BE ABLE TO GET BRIEF SNOW SQUALLS IN HIGHER
INTENSITY PRECIPITATION BANDS. IN GENERAL...EXPECT PRECIPITATION
AMOUNTS TO BE FAIRLY LIGHT...WITH A FEW HUNDREDTHS OF AN INCH OR
LESS IN MOST LOCATIONS. APPEARS TO BE QUITE BREEZY WITH 20-30 KNOTS
OF FLOW AT 925 HPA COMBINED WITH LOW LEFT COLD AIR ADVECTION AIDING
IN MIXING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 254 PM CDT TUE APR 23 2013
THE TAIL END OF THE WAVE WILL BE MOVING THROUGH EARLY ON WEDNESDAY
EVENING MAY ALLOW FOR A FEW STRAGGLING SHOWERS IN THE FAR EASTERN
CWA...OTHERWISE CLEARING SKIES AND LIGHTER WINDS SHOULD ALLOW FOR
A COOL NIGHT AS NORTHWEST WINDS RELAX TO WEST AND SOUTHWEST. LOWS
SHOULD MAINLY BE IN THE 20S WITH A FEW TEENS POSSIBLE AREAS WITH
DEEPER SNOW COVER.
THURSDAY WILL PROVE TO BE A DECENT SNOW MELTING DAY WITH MOSTLY
SUNNY TO PARTLY CLOUD CONDITIONS AND MILDER READINGS. LOW LEVEL
WIND DIRECTION AND THE LOCATION OF THE INCOMING WARM FRONT WILL
PLAY A BIG ROLE ON WHERE THE BEST WARMING WILL BE. WILL AIM FOR
THE WARMEST READINGS WEST OF THE JAMES RIVER VALLEY WHERE THE BEST
CHANCE RESIDES OF WINDS BECOMING SOUTH OR SLIGHTLY SOUTHWEST. THE
FARTHER EAST FROM HERE THE BETTER CHANCE THAT A SOUTHEAST
COMPONENT WILL HANG IN. WILL HAVE HIGHS RANGING FROM 60 TO 65 WEST
OF THE JAMES TO AROUND 50 NORTH AND EAST OF A BROOKINGS TO JACKSON
LINE.
THURSDAY NIGHT INTO FRIDAY WILL SEE A SOUTHERLY WIND TURNS A BIT
SOUTHWEST WHICH WILL BRING THE PROBABILITY FOR MUCH WARMER
READINGS AND LIKELY THE FINAL DAY WITH ANY REAL SNOW COVER LEFT ON
THE GROUND. NOT PLANNING ON THE SNOW COVER HAVING MUCH OF AN
EFFECT SO WILL GO WITH HIGHS MAINLY IN THE 60S.
THE BIG WARM UP IS STILL ON TAP THIS WEEKEND AND WILL CONTINUE TO
KEEP ABOVE NORMAL TEMPERATURES GOING. THE MAIN DIFFERENCES IN THE
MODELS SHOW UP AROUND MONDAY WHERE THE GFS DIVES COLDER AIR SOUTH
AS A FAIRLY STRONG TROUGH MOVES THROUGH NORTH DAKOTA. THE ECMWF
AND THE EXTRAPOLATED GEM ARE LESS BOISTEROUS WITH THIS WAVE AND
MORE OR LESS RIDE THE ENERGY ALONG AND NORTH OF THE PERIPHERY OF
THE RIDGE...KEEPING THE WARM AIR IN PLACE THROUGH TUESDAY. WILL
STICK CLOSEST TO THE GEM/ECMWF OUTPUT WHICH SEEMS MORE REASONABLE
AND THE GFS IS LIKELY PUSHING THE TROUGH TO AGGRESSIVELY THROUGH
THE EXISTING RIDGE. NOT PLANNING ON ANY REAL ISSUES WITH
PRECIPITATION DURING THIS TIME FRAME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1102 PM CDT TUE APR 23 2013
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. MODEL SOUNDINGS
SUGGEST THE POTENTIAL FOR FOG...HOWEVER WITH ONLY LIMITED SNOW MELT
WILL LEAVE OUT ANY MENTION FOR TONIGHT. PRECIPITATION IS EXPECTED TO
DEVELOP AROUND KHON AROUND MID TO LATE MORNING AND SPREAD EAST
THROUGH THE DAY. IMPACT SHOULD BE MINOR...WITH ONLY A BRIEF DIP IN
CEILINGS EXPECTED. WEST NORTHWEST WINDS WILL ALSO BECOME BREEZY
THROUGH THE DAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...
LONG TERM...08
AVIATION...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
517 AM EDT WED APR 24 2013
.SYNOPSIS...
LOW PRESSURE WAS OVER THE GREAT LAKES WITH A COLD FRONT EXTENDING
INTO SOUTHERN TEXAS. THIS FRONT WILL CROSS THE REGION TODAY WITH
HIGH PRESSURE FOLLOWING FOR THURSDAY AND FRIDAY. LOW PRESSURE
WILL MOVE FROM THE SOUTHERN PLAINS ACROSS THE TENNESSEE VALLEY AND
CAROLINAS ON SATURDAY AND SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 430 AM EDT WEDNESDAY...
STARTING OUT WITH LITTLE CLOUD COVER THIS MORNING. ONCE MIXING
BEGINS WINDS WILL GUST OUT OF THE SOUTHWEST AND TEMPERATURES WILL
WARM UP QUICKLY. BY THIS AFTERNOON CLOUD COVER MOVES IN SLOWING
DOWN HEATING FOR THE REST OF THE DAY. SHORT RANGE
MODELS...INCLUDING THE RUC AND WRF...HAVE SLOWED DOWN THE TIME OF
THE FRONTAL PASSAGE BY A COUPLE OF HOURS. FORECAST HAS THE FRONT
MOVING THROUGH THE COUNTY WARNING AREA BETWEEN 6PM AND MIDNIGHT.
SHOWERS AND THUNDERSTORMS MAY COME THROUGH IN TWO BANDS. ONE ALONG
THE FRONT...SIMILAR TO WHAT WAS DEVELOPING AROUND 5AM FROM
KENTUCKY TO LOUISIANA...AND THE SECOND...BEHIND THE FRONT.
CONVECTIVE AVAILABLE POTENTIAL ENERGY HAS THE POTENTIAL TO REACH
AROUND 1500 J/KG THIS AFTERNOON BUT MODELS DROP OFF INSTABILITY
QUICKLY AFTER SUNSET.
QUESTIONABLE IF ANY OF THE PRECIPITATION BEHIND THE FRONT WILL
HOLD TOGETHER EAST OF THE BLUE RIDGE. ONCE THE WIND SHIFT TO THE
NORTHWEST...TENDENCY IS FOR DOWNSLOPING COMPONENT TO ERODE
PRECIPITATION. HAVE KEPT PROBABILITY OF PRECIPITATION HIGHEST IN
THE FAR WESTERN COUNTY WARNING AREA AND MUCH LOWER IN THE EAST.
GOOD PRESSURE RISES AND COLD AIR ADVECTION BEHIND THE FRONT
TONIGHT WILL RESULT IN GUSTY NORTHWEST WINDS. THE COOLER AIR MASS
COMING IN WILL HOLD LOW TEMPERATURES BELOW NORMAL.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 327 AM EDT WEDNESDAY...
HIGH PRESSURE STRENGTHENS AND STRETCHES INTO THE MIDDLE ATLANTIC
THURSDAY AND THURSDAY NIGHT. ONE FINAL SHRTWV WITH SCANT MOISTURE
CUTTING THROUGH WEST VA WILL THROW SOME CLOUDS BRIEFLY INTO SE WEST
VA LATE THURSDAY AFTERNOON BEFORE DEPARTING THURSDAY NIGHT.
FRIDAY MORNING LOOKS LIKE A CHILLY ONE WITH SOME MINS NEAR
FREEZING AT THE COLDEST SPOTS AND POTENTIALLY NEAR THE MIDDLE 30S
ACROSS THE VIRGINIA PIEDMONT WHICH MAY LEAD TO SOME PATCHY FROST.
AS THE HIGH DEPARTS LATER FRIDAY SOME HIGH CLOUDS ARRIVE BEFORE
MOISTURE INCREASES AND WINDS BEGIN TO TAKE ON AN EASTERLY
COMPONENT INTO THE WEEKEND. PINPOINTING POPS FOR THIS WEEKEND
REALLY TOUGH RIGHT NOW WITH MODELS NOT SHOWING A LOT OF MEASURABLE
PRECIP SAVE THE NC/VA BORDER. BUT...WOULD THINK SE TO ESE FLOW AND
ABUNDANT MOISTURE WOULD BE ENOUGH FOR SOME LIGHT RAIN SATURDAY OR
SATURDAY NIGHT...FURTHER NORTH THAN MOST MODELS DEPICT. THE 0Z
ECMWF CONTINUES TO BE THE WETTEST SOLUTION BUT EVEN IT HAS NOW
SHIFTED THE PRECIP FURTHER SOUTH. NONETHELESS...GUIDANCE FOR MAX T
SATURDAY SEEMED SEVERAL DEGREES TOO WARM CONSIDERING ALL OF THE
ABOVE...SO WENT BELOW THE MEX MOS NUMBERS...SUBSTANTIALLY SO IN
THE TYPICAL WEDGE AREAS.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 355 PM EDT THURSDAY...
CONSIDERABLE DIFFERENCES REMAIN AMONG THE GFS AND ECMWF DURING THE
EXTENDED PERIODS...BUT ANY WAY YOU LOOK AT IT...IT IS GOING TO BE
WET AND UNSEASONABLY COOL. A VIGOROUS SOUTHERN STREAM DISTURBANCE
IS STILL SLATED TO MOVE INTO THE REGION FROM THE WEST. IT IS THE
SUBSEQUENT MOVEMENT/DEVELOPMENT OF THIS SYSTEM THROUGH THE WEEKEND
INTO EARLY NEXT WEEK THAT BECOMES THE QUESTION. THE GFS HAS IN
GENERAL SHOWN MORE CONSISTENCY WITH THE EVOLUTION OF THIS SYSTEM
THAN THE ECMWF. EACH RUN OF THE ECMWF DEVELOPS A CUTOFF IN A
DIFFERENT LOCATION...WHICH IS RESULTING IN LOWERING CONFIDENCE IN
ANY ONE SOLUTION FROM THAT MODEL.
HOWEVER...BOTH THE GFS AND ECMWF GIVE SOME HINT OF AT LEAST WEAK
CUTOFF LOW PRESSURE DEVELOPING ACROSS THE SOUTHEAST STATES IN A
WEAKNESS AREA. THEREFORE...HAVE KEPT LIKELY POPS SAT-SUN...THEN
TAPER TO MOSTLY CHANCE POPS DURING THE LATER PERIODS. THE LATEST
ECMWF HAS DEFINITELY TRENDED TOWARD A DRIER/WEAKER SOLUTION.
INSTABILITY IS NIL THROUGH THE PERIOD AND WITH BOTH MODELS THERE
IS A STRONG SIGNAL FOR A WEDGE REINFORCED...HENCE IN SITU AS WELL.
HAVE FAVORED THE MUCH COOLER ECMWF GRIDS THROUGHOUT THE EXTENDED
PERIODS.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
AS OF 145 AM EDT WEDNESDAY...
HAVE ADDED LLWS TO ALL TAFS...BCB/BLF/LWB/ROA/LYH/DAN...FOR THE
BEGINNING OF THE FORECAST PERIOD SINCE THE LOW LEVEL JET WILL BE
INCREASING FROM THE SOUTHWEST AHEAD OF THE APPROACHING COLD FRONT.
BUFKIT INDICATED JET WOULD BE IN THE 32 TO 37 KNOT RANGE FROM THE
SOUTHWEST.
CLOUDS WILL INCREASE THROUGHOUT THE DAY...ALTHOUGH CEILINGS WILL
REMAIN VFR. ONCE INVERSION BREAKS THIS MORNING AND MIXING
BEGINS...WINDS WILL GUST 20 TO 30 KNOTS FROM THE SOUTHWEST.
LOW PRESSURE MOVING ACROSS THE GREAT LAKES WILL BRING A COLD FRONT
THROUGH THE REGION THIS EVENING. EXPECT FRONTAL PASSAGE AND WIND
SHIFT TO THE NORTHWEST AROUND 23Z/7PM AT BLF AND LWB AND BETWEEN
00Z/8PM AND 03Z/11PM AT BCB/ROA/DAN/LYH. LESS CERTAIN ABOUT HOW
MUCH PRECIPITATION WILL BE AHEAD OF THE FRONT...OR HOW MUCH WILL
FALL BEHIND THE FRONT. CEILINGS MAY DROP TO MVFR AT BLF AND LWB
BEHIND THE FRONT. THE SHOWERS MAY NEVER REACH DAN AND LYH WITH
NORTHWEST DOWNSLOPE WINDS AND THE PRECIPITATION MAINLY BEHIND THE
BOUNDARY.
HIGH PRESSURE WILL BUILD IN QUICKLY IN THE WAKE OF THE COLD FRONT
FOR THURSDAY AND FRIDAY. ANY MVFR CEILINGS WILL BE WEST OF THE
BLUE RIDGE...AND WILL IMPROVE TO VFR THURSDAY MORNING.
THIS WEEKEND WILL BE UNSETTLED WITH PERIODS OF SHOWERS BEGINNING
SATURDAY AFTERNOON. EXPECT PERIODS OF IFR/MVFR CONDITIONS SATURDAY
AFTERNOON THROUGH THE REST OF THE WEEKEND.
&&
.FIRE WEATHER...
AS OF 515 AM EDT WEDNESDAY...
BREEZY SOUTHWEST WINDS AHEAD OF AN APPROACHING COLD FRONT
TODAY. SOUTHWEST WINDS OF 10 TO 15 MPH WITH GUSTS OF 20 TO 30 MPH
ARE LIKELY BY THIS AFTERNOON. THE WIND WILL ABRUPTLY SHIFT TO THE
NORTHWEST WITH THE PASSAGE OF THE FRONT THIS EVENING. THE FRONT
IS EXPECTED TO CROSS THE MOUNTAINS BETWEEN 6-9PM...THEN MOVE EAST
OF THE BLUE RIDGE AND ACROSS THE PIEDMONT BEFORE MIDNIGHT.
THE CHANCE OF RAIN MOVES BACK INTO THE FORECAST AREA AGAIN ON
SATURDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/PM/WP
SHORT TERM...KM
LONG TERM...RAB
AVIATION...AMS
FIRE WEATHER...AMS/PM
AREA FORECAST DISCUSSION
NWS EUREKA CA
353 AM PDT WED APR 24 2013
.SYNOPSIS...HIGH PRESSURE WILL MAINTAIN DRY WEATHER THROUGH THE
WEEK. COASTAL STRATUS ALONG THE MENDOCINO COAST WILL MOVE NORTH
IMPACTING THE REDWOOD COAST BY LATE THIS AFTERNOON AND EVENING.
&&
.DISCUSSION...SAT IMAGERY SHOWS STRATUS EXPANDING SLOWLY N ALONG
THE MENDO COAST JUST MOVG INTO SHELTER COVE ATTM. MAIN FCST
CHALLENGE WILL BE TIMING STRATUS SURGE AROUND CAPE MENDO AND
COASTAL TEMPS TODAY. MODELS CONTINUE TO INITIALIZE STRATUS AND
SLY WINDS POORLY ALTHOUGH LATEST COUPLE OF RUNS OF HRRR BECMG MORE
CONSISTENT WITH SAT IMAGERY. NLY GRADIENT CONTINUES WITH BUOY22
REPORTING 20G30KT WINDS. EXPECT STRATUS TO REMAIN S OF CAPE MENDO
THROUGH THE MORNING. NLY GRADIENT WILL EASE THIS AFTERNOON
ALLOWING STRATUS TO ROUND THE CAPE AND SURGE N ALONG THE REDWOOD
COAST. COASTAL TEMPS WILL BE SLIGHTLY COOLER N OF CAPE MENDO AS
OFFSHORE FLOW AND DOWNSLOPING EFFECTS WILL BE LESS. NIGHT/MORNING
STRATUS WILL CONTINUE TO IMPACT COASTAL AREAS WHILE ABOVE NORMAL
TEMPS CONTINUE ACROSS THE INTERIOR. MODELS CONTINUE TO SHOW
ANOTHER WEAK SYSTEM IMPACTING THE PAC NW THIS WEEKEND...BUT LATEST
RUNS KEEP PRECIP N OF THE OR BORDER WITH MAIN IMPACT BEING COOLER
TEMPS ACROSS THE INTERIOR.
&&
.AVIATION...FOG SATELLITE SHOWS STRATUS ALONG THE COAST, SURGING
FROM THE SOUTH. AS IT HITS THE REDWOOD COAST DURING THE MORNING AND
AFTERNOON IT WILL BRING REDUCED CONDITIONS TO THE COASTAL AIRSTRIPS.
INLAND...VFR IS EXPECTED TO PREVAIL.
&&
.MARINE...NORTHERLY WINDS WILL EASE TODAY AND WAVES WILL SUBSIDE AS
THE PRESSURE GRADIENT WEAKENS. NEARSHORE NOAA BUOYS 22 AND 27 SHOW
NORTHERLY WINDS AROUND 20 KT WHILE NOAA BUOY 14 HAS LIGHT WINDS FROM
THE SOUTH,WHERE THE SOUTHERLY STRATUS SURGE HAS PASSED. THE 0630Z
ASCAT PASS SHOWED WINDS OF ABOUT 30 KT ACROSS ZONE 470 AND 20-25 KT
ACROSS ZONE 475. SINCE WAVES ARE STARTING TO TREND DOWNWARD IT IS
BELIEVED THAT THE WINDS HAVE EASED SUBSTANTIALLY OFFSHORE, SO LET
BOTH THE GALE AND HAZARDOUS SEAS WARNINGS EXPIRE. DID EXTEND THE SCA
FOR ZONE 450 FOR A FEW HOURS SINCE WINDS AND WAVES STAYED UP A
LITTLE BIT LONGER THAN EXPECTED. THE TREND FOR TODAY INTO THURSDAY
WILL BE EASING WINDS, WITH WINDS TURNING TO THE SOUTH ALONG THE
NEARSHORE. EXPECT LIGHT TO MODERATE WINDS AND LOW SEAS THURSDAY AND
FRIDAY. WINDS AND WAVES SHOULD INCREASE THIS WEEKEND AS THE PRESSURE
GRADIENT STRENGTHENS.
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 9 AM PDT THIS MORNING FOR PZZ450-475.
SMALL CRAFT ADVISORY UNTIL 8 PM PDT THIS EVENING FOR PZZ470.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
FOLLOW US ON FACEBOOK AND TWITTER AT:
HTTP://WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.EUREKA.GOV
HTTP://WWW.TWITTER.COM/NWSEUREKA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1040 AM EDT WED APR 24 2013
.SYNOPSIS...
A MILDER AIR MASS WILL YIELD ABOVE NORMAL TEMPERATURES
THIS AFTERNOON BEFORE A COLD FRONT ARRIVES WITH SHOWERS...AND
PERHAPS A FEW THUNDERSTORMS...IN THE EVENING. HIGH PRESSURE WILL
BRIEFLY BUILD INTO THE REGION WITH SEASONABLE TEMPERATURES FOR
THURSDAY. A STRONG UPPER LEVEL DISTURBANCE MAY BRING ISOLATED TO
SCATTERED RAIN AND SNOW SHOWERS TO PARTS OF EASTERN NEW YORK AND
WESTERN NEW ENGLAND THURSDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1040 AM EDT...WHILE MUCH OF THE REGION CURRENTLY HAS A MOSTLY
SUNNY SKY...HIGH CLOUDS ARE STARTING TO SPREAD ACROSS WESTERN PARTS OF
THE AREA LATE THIS MORNING AS A FRONTAL SYSTEM BEGINS TO APPROACH
FROM THE WEST.
A FEW RAIN SHOWERS DEVELOPED OUT WELL AHEAD OF THE COLD FRONT ACROSS
WESTERN AND CENTRAL NEW YORK...BUT OUR LOCAL HIRES WRF AND THE
3KM HRRR MODEL ALL SUGGESTED THESE WOULD START TO DIMINISH AS THEY
APPROACHED OUR AREA. RADAR TRENDS OVER THE LAST 30 MINUTES HAVE
SUGGESTED THIS LOOKS TO BE THE CASE...SO WE HAVEN/T MADE ANY MAJOR
ADJUSTMENTS TO OUR POPS ACROSS WESTERN AREAS...WITH JUST SLIGHT
CHC/LOW CHC POPS FOR THE LATE MORNING/EARLY AFTN FOR WESTERN
AREAS.
THE NAM/GFS/ECMWF/CANADIAN GUIDANCE ARE ALL IN PRETTY GOOD AGREEMENT
REGARDING THE TIMING OF THE SHOWERS ASSOCIATED WITH THE FRONT
UNTIL THE MID TO LATE PM FOR THE EXTREME NW ZONES...AND THEN
GRADUALLY SPREADING THEM EASTWARD FOR THE EARLY EVENING. THE BEST
CHC OF SHOWERS WILL BE WEST OF THE HUDSON RIVER VALLEY PRIOR TO 6
PM. A SLIGHT CHC OF THUNDERSTORMS WAS KEPT IN FROM THE MOHAWK
VALLEY SOUTHWARD DUE TO POCKETS OF ELEVATED INSTABILITY...AS THE
SHOWALTER INDICES LOWER TO 0 TO -1C. THE MID LEVEL LAPSE RATES
START TO STEEPEN IN THE H700-H500 RANGE TO 6.5-7.5C/KM...BUT LACK
OF APPRECIABLE INSTABILITY...DEEPER MOISTURE...AND FAVORABLE MID
AND UPPER LEVEL JET DYNAMICS SHOULD LIMIT THE THUNDERSTORMS THAT
DUE FORM TO NON- SEVERE LEVELS. MORE DISCUSSION ON THE CONVECTION
IN THE SHORT TERM.
THE H850 TEMPS INCREASE +9 TO +13C AHEAD OF THE FRONT. THE H850
FLOW INCREASES FORM THE S/SW TO 40-55 KTS BY NIGHTFALL. IT WILL
BECOME BREEZY IN THE PM WITH SOUTHERLY WINDS OF 10 TO 20 MPH WITH
SOME GUSTS 30-35 MPH. MAX TEMPS IN THE U60S TO L70S WILL BE COMMON
IN THE VALLEYS...AND 60S WILL BE LIKELY OVER THE MTNS WITH SFC
DEWPTS RISING INTO THE 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...THE BEST CHC FOR WIDESPREAD RAINFALL FROM THE FRONT
LOOKS TO BE IN THE 6 PM TO MIDNIGHT TIME FRAME. THERE IS DECENT
LOW-LEVEL CONVERGENCE ALONG AND IN THE WAKE OF THE COLD FRONT. THE
BETTER JET STREAK ALOFT RACES INTO QUEBEC...AS THE UNFAVORABLE
RIGHT FRONT QUAD OF A 125+ KT H250 JET STREAK MOVES OVER THE SRN
HALF OF THE FCST AREA...WHICH WILL DAMPEN THE PCPN A BIT SOUTH AND
EAST OF THE CAPITAL REGION.
THE THREAT FOR ISOLATED THUNDERSTORMS WAS KEPT IN UNTIL MIDNIGHT
FROM THE CAPITAL REGION...MOHAWK VALLEY...BERKSHIRES SOUTH. POPS
WERE INCREASED TO LIKELY AND CATEGORICAL VALUES. THE STEEPENING MID
LEVEL LAPSE RATES...AND STRENGTHENING LOW LEVEL JET ASSOCIATED
WITH THE FRONT WARRANTED PUTTING SOME WIND GUSTS TO 30 TO 40
MPH...ESPECIALLY JUST IN THE WAKE OF THE FRONT. THE PWATS DO
EXCEED AN INCH FOR A BRIEF PERIOD OF TIME /COUPLE STANDARD
DEVIATIONS ABOVE NORMAL/...BUT DROP OFF WITH THE BLAST OF COLD
ADVECTION THAT FOLLOWS THE FRONTAL PASSAGE. QPF WILL RANGE FROM A
TENTH OF AN INCH OR SO...OVER THE SOUTHEAST CORNER OF THE FCST
AREA...TO UP TO A HALF AN INCH OVER THE NW EXTREME. SOME OF THE
RESIDUAL POST FRONTAL SHOWERS OVER THE SRN DACKS MAY TRANSITION TO
SNOW SHOWERS WITH LIGHT COATINGS TO A FEW TENTHS OF AN INCH IN A
FEW SPOTS. MIN TEMPS ARE TRICKY TIMING THE COLD ADVECTION. THERE
ARE LARGE DIFFERENCE BTWN THE NAM AND GFSMOS. THE GFS IS MUCH
COLDER BY ALMOST 10 DEGREES IN SOME LOCATIONS. LEANED CLOSER TO THE
WARMER NAM MOS GUIDANCE DUE TO ITS TRACK RECORD LATELY...AND
ACTUALLY WENT CLOSE TO THE ECM MOS GUIDANCE. LOWS EXPECTED IN THE
L40S IN THE HUDSON RIVER VALLEY...BERKS...CT RIVER VALLEY AND NW
CT...MID AND U30S ELSEWHERE...EXCEPT SOME U20S TO L30S OVER THE
SRN DACKS.
THURSDAY...HIGH PRESSURE QUICKLY RIDGES IN FROM THE SOUTH AND WEST
WITH A BRIEF PERIOD OF DRY WEATHER...AS A POTENT SHORT-WAVE TROUGH
QUICKLY MOVES TOWARDS THE REGION FROM THE GREAT LAKES REGION. THIS
DAY WILL BE SEASONABLY WARM AND DRY WITH H850 TEMPS IN THE 0C TO
-4C RANGE OVER THE REGION. EXPECT U50S TO L60S IN THE
VALLEYS...AND U40S TO M50S OVER THE HIGHER TERRAIN.
THURSDAY NIGHT...TRICKY DYNAMIC SHORT-WAVE LACKING ROBUST LOW-
LEVEL MOISTURE TO WORK WITH. THE NAM HAS THE TROUGH PASS THROUGH
FAIRLY DRY. THE GFS/ECMWF CONTINUE TO PAINT LIGHT AMOUNTS OF QPF
OF A FEW HUNDREDTHS TO A TENTH OF AN INCH FROM THE ERN
CATSKILLS...CAPITAL REGION...NRN BERKS NORTHWARD. THE DIFFERENTIAL
CYCLONIC VORTICITY WILL TRIGGER SOME ISOLD-SCT RAIN AND SNOW
SHOWERS. THERE WILL LIKELY BE A QUICK SHOT OF RADIATIONAL COOLING
AHEAD OF THIS POTENT SHORT-WAVE WITH TEMPS FALLING INTO THE M20S
TO M30S ACROSS THE REGION. COATING TO HALF INCH SNOW AMOUNTS WILL
BE POSSIBLE ESPECIALLY FOR ELEVATIONS 500 FT AND GREATER...A
LITTLE WET SNOW MIGHT ALSO OCCUR AT THE VALLEY FLOOR LOCATIONS.
FRIDAY...LOW AND MID LEVEL HEIGHTS QUICKLY RISE AS THE SHORT-WAVE
TROUGH ZIPS BY NRN NEW ENGLAND BY THE PM. SFC HIGH PRESSURE BUILDS
IN FROM THE OHIO VALLEY...AND THE GREAT LAKES REGION WITH FAIR AND
DRY WX FOR THE AFTERNOON. EXPECT HIGHS IN THE L60S IN THE CAPITAL
REGION...MID HUDSON VALLEY...CNTRL AND SRN TACONICS...AND NW CT.
MID AND U50S WILL PREVAIL IN ALL OTHER LOCATIONS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
RATHER UNUSUAL TO BE FORECASTING AN ENTIRELY DRY LONG TERM
PERIOD...HOWEVER THAT IS THE CASE WITH THIS LONG TERM FORECAST.
HIGH PRESSURE WILL DOMINATE OUR WEATHER INITIALLY BUILDING AT THE
SURFACE AND THEN ALOFT AS WELL BY MONDAY AND TUESDAY. THE
STRENGTHENING HIGH PRESSURE SYSTEM WILL KEEP ANY MOISTURE WHICH
TRIES TO LIFT NORTHWARD WELL SOUTH OF OUR REGION.
EXPECT HIGHS ON SATURDAY TO BE IN THE UPPER 50S TO MID 60S WITH
HIGHS SUNDAY THROUGH TUESDAY MAINLY IN THE 60S TO AROUND 70. LOWS
FRIDAY NIGHT ARE EXPECTED TO RANGE FROM THE MID 20S TO MID 30S WITH
LOWS SATURDAY NIGHT IN THE 30S TO AROUND 40 AND LOWS SUNDAY NIGHT
AND MONDAY NIGHT IN THE UPPER 30S TO MID 40S.
OVERALL EXPECT TEMPS IN THE LONG TERM PERIOD TO AVERAGE SLIGHTLY
ABOVE NORMAL WITH PRECIPITATION BELOW NORMAL.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
FOR THE TAF SITES EXPECT MAINLY VFR CONDITIONS AS COASTAL LOW PULLS
AWAY FROM THE REGION EARLY THIS MORNING. THE EXCEPTION WILL BE AT
KPSF WHERE LOW STRATUS WILL RESULT IN MVFR TO PERHAPS IFR CONDITIONS
UNTIL AROUND 14Z. AHEAD OF THE COLD FRONT WHICH WILL BE
MOVING THROUGH THE TAF SITES THIS EVENING...EXPECT ONLY MID AND HIGH
CLOUDS THROUGH MUCH OF THIS AFTERNOON. SHOWERS ARE EXPECTED TO
ARRIVE LATE THIS AFTERNOON OR EARLY THIS EVENING WITH VSBYS 3-6SM
AND CIGS GENERALLY OVC035-050 EXCEPT MVFR CIGS PSBL AT KPSF. THE
SHOWERS ARE EXPECTED TO END LATE TONIGHT WITH A RETURN TO VFR
CONDITIONS AS CLOUDS BREAK UP
WINDS WILL GENERALLY BE SOUTH INCREASING TO 10 KTS THIS MORNING
WITH GUSTS 20-25 KTS THIS AFTERNOON. WINDS WILL SHIFT TO THE
SOUTHWEST AND THEN WEST IN WAKE OF COLD FRONT THIS EVENING AND
REMAIN FAIRLY STRONG AND GUSTY ESPECIALLY AT KALB. WINDS LATE
TONIGHT WILL BE WEST TO NORTHWEST AT 8-12 KTS.
OUTLOOK...
THU-SUN...VFR...NO SIG WX.
&&
.FIRE WEATHER...
A COLD FRONT WILL BRING SHOWERS AND ISOLATED THUNDERSTORMS TO
EASTERN NEW YORK AND WESTERN NEW ENGLAND LATE THIS AFTERNOON INTO
THE OVERNIGHT PERIOD. HIGH PRESSURE WILL BRIEFLY BUILD IN ON
THURSDAY WITH AN UPPER LEVEL DISTURBANCE PRODUCING SOME ISOLATED
TO SCATTERED RAIN AND SNOW SHOWERS.
RH VALUES WILL LOWER TO 30 TO 40 PERCENT LATE THIS
AFTERNOON...AND THEN RISE TO 75 TO 100 PERCENT TONIGHT. THE RH VALUES
WILL DROP TO 20-30 PERCENT BY THURSDAY AFTERNOON.
THE WINDS WILL INCREASE FROM THE SOUTH AT 10 TO 20 MPH WITH SOME
GUSTS TO 30 MPH TODAY. THE WINDS WILL SHIFT TO THE SOUTHWEST OR WEST
AT 10 TO 20 MPH TONIGHT WITH SOME GUSTS IN THE 30 TO 40 MPH RANGE
WITH THE FRONTAL PASSAGE. THE WINDS WILL BE FROM THE NORTHWEST AT
10 TO 15 MPH WITH A FEW LOCATIONS HAVING GUSTS TO 25 MPH ON
THURSDAY.
A WETTING RAINFALL WILL OCCUR LATE THIS AFTERNOON INTO TONIGHT
WITH A QUARTER TO HALF AN INCH OF RAIN EXPECTED FROM THE CAPITAL
REGION...BERKSHIRES AND EASTERN CATSKILLS NORTHWARD...WITH LESS
THAN A QUARTER OF AN INCH POSSIBLE FURTHER SOUTH.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED OVER THE NEXT 5 DAYS.
THE NEXT WIDESPREAD RAINFALL IS EXPECTED LATE THIS AFTERNOON INTO
TONIGHT. THE HPC QPF HAS LOWERED A BIT WITH GENERALLY A QUARTER TO
A HALF AN INCH OF RAINFALL FROM THE CAPITAL
REGION...BERKSHIRES...AND THE EASTERN CATSKILLS NORTHWARD...WITH
LESS THAN A QUARTER INCH FOR MOST LOCATIONS TO THE SOUTH. SNOWMELT
WILL CONTINUE ACROSS THE ADIRONDACKS AND SOUTHERN GREENS ON
WEDNESDAY...DUE TO MAX TEMPS REACHING INTO THE 60S AND DEWPOINTS
GETTING INTO THE 40S. DESPITE THE SNOWMELT...WHICH IS MUCH MORE
LIMITED DUE TO THE SMALLER AREAL COVERAGE...THE EXPECTED RAINFALL
LOOKS LIGHT ENOUGH TO AVOID ANY ISOLATED HYDROLOGIC ISSUES IN
THOSE AREAS.
DRY WEATHER WILL RETURN FOR THURSDAY WITH HIGH PRESSURE IN
CONTROL. ISOLATED TO SCATTERED LIGHT RAIN OR SNOW SHOWERS MAY
RETURN FOR THURSDAY NIGHT FOR LOCATIONS NORTH OF THE MID HUDSON
VALLEY AND NW CT. RIVERS AND STREAMS WILL CONTINUE TO RECEDE WITH
DRY WEATHER EXPECTED THE NEXT SEVERAL DAYS BEYOND THURSDAY NIGHT.
FOR DETAILS ON SPECIFIC AREA RIVERS AND
LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE
ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION
SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/WASULA
NEAR TERM...FRUGIS/WASULA
SHORT TERM...WASULA
LONG TERM...11
AVIATION...11
FIRE WEATHER...WASULA
HYDROLOGY...FRUGIS/WASULA
AREA FORECAST DISCUSSION
NWS LINCOLN IL
957 AM CDT WED APR 24 2013
.DISCUSSION...
ISSUED 954 AM CDT WED APR 24 2013
SATELLITE IMAGERY SHOWING THE BACK EDGE OF THE CLOUDS STARTING TO
APPROACH THE ILLINOIS RIVER. LATEST GUIDANCE FROM THE RAP SHOWS A
BIT OF SLOWING DOWN OF THE CLEARING THROUGH MIDDAY...WITH THE
EASTERN CWA STILL HAVING A FAIR AMOUNT OF CLOUDINESS INTO EARLY
AFTERNOON. THE LINGERING RAIN AND SNOW SHOWERS IN THE EASTERN CWA
STILL ON TRACK TO EXIT THE AREA OVER THE NEXT COUPLE HOURS.
FORECAST IS GENERALLY ON TRACK. HAVE SENT SOME MINOR GRID UPDATES TO
REFRESH THE CURRENT TRENDS...BUT WILL HOLD OFF A BIT LONGER ON
UPDATING THE ZONE FORECASTS UNTIL THE PRECIP HAS EXITED THE AREA.
GEELHART
&&
.AVIATION...
ISSUED 649 AM CDT WED APR 24 2013...FOR THE 12Z TAFS
POST FRONTAL PRECIP WILL GRADUALLY DIMINISH THIS MORNING AS DRY
AIR ALOFT BEGINS TO ERODE THE LOW LEVEL MOIST LAYER. SPRINKLES OR
DRIZZLE WILL CONTINUE FOR THE FIRST 2 TO 4 HOURS OF THIS TAF
PERIOD. THERE MAY EVEN BE SNOW SNOW FLURRIES AS THE COLD AIR ALOFT
CONTINUES TO COOL DOWN FARTHER BELOW FREEZING. NO SNOW ACCUM WILL
OCCUR.
IFR CLOUD HEIGHTS IN BMI SHOULD LIFT TO MVFR BY 14Z...WHILE THE
OTHER SITES REMAIN AT MVFR UNTIL 18Z TO 21Z FROM WEST TO EAST. THE
CLEARING LINE OF CLOUDS SHOULD PROGRESS EASTWARD AT A STEADY PACE
TODAY AS THE UPPER FLOW BEGINS TO BECOME MORE PERPENDICULAR TO THE
LOWER LEVEL FRONT.
WINDS WILL REMAIN NORTHWEST TODAY IN THE 12-15KT RANGE...THEN
BECOME LIGHT SOUTHWEST TONIGHT AS THE SURFACE RIDGE BUILDS INTO IL
FROM THE WEST.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT WED APR 24 2013
00Z MODELS ARE IN FAIR AGREEMENT NEXT FEW DAYS AND WILL USE A
BLEND. MET AND MAV GUIDANCE TEMPS SIMILAR THROUGH FRIDAY AND
STAYED CLOSE TO.
SHORT TERM...TODAY THROUGH SATURDAY
WIDESPREAD BAND OF SHOWERS AND ISOLATED THUNDERSTORMS WAS SE OF A
DANVILLE TO SHELBYVILLE LINE EARLY THIS MORNING WITH PERIODS OF
MODERATE TO HEAVY RAIN SHOWERS AT TIMES. CUMBERLAND AND EFFINGHAM
COUNTIES HAVE AN URBAN AND SMALL STREAM FLOOD ADVISORY UNTIL 10 AM.
SHOWERS WILL GRADUALLY DIMINISH OVER SE IL DURING THIS MORNING AND
COULD STILL SEE A FEW SNOWFLAKES INTO MID MORNING ON NW EDGE OF
THIS PRECIPITATION. TEMPS CURRENTLY IN THE UPPER 30S OVER CENTRAL
IL AND 40-45F IN SE IL WITH BLUSTERY NNW WINDS 10-20 MPH. 1007 MB
LOW PRESSURE WAS DEEPENING OVER NW OHIO WITH ITS COLD FRONT INTO
NW KY/TN. 1028 MB HIGH PRESSURE WAS OVER NORTH TEXAS AND WESTERN
OK INTO SE CO. SLOWED DOWN THE CLEARING OF LOW CLOUDS TODAY AS A
STRONG SHORT WAVE OVER THE CENTRAL PLAINS MOVES EAST INTO IL BY
18Z TODAY THEN EXITS QUICKLY NE OF IL DURING THE AFTERNOON WHEN
LOW CLOUDS WILL DECREASE. HIGHS IN THE LOWER 50S WITH SOME UPPER
40S OVER EAST CENTRAL IL.
WEAK LOW PRESSURE AROUND 1015 MB MOVES INTO THE NORTHERN GREAT
LAKES BY DAWN THU AND BRINGS A WEAK COLD FRONT INTO CENTRAL IL
WHILE ANOTHER FAIRLY STRONG SHORT WAVE/TROF DIGS INTO LAKE MI.
THIS TO KEEP BRUNT OF MIXED LIGHT PRECIPITATION NORTH OF CENTRAL
IL WITH JUST SLIGHT CHANCES BETWEEN 10 PM AND 4 AM NORTH OF PEORIA.
LOWS IN THE MID TO UPPER 30S AGAIN TONIGHT. 1027 MB HIGH PRESSURE
BUILDS INTO THE MID MS VALLEY BY SUNSET THU BRINGING MORE SUNSHINE
AND HIGHS IN THE MID TO UPPER 50S. LOWS THU NIGHT IN THE UPPER 30S
TO NEAR 40F WITH COOLEST READINGS IN EAST CENTRAL IL WHERE MID 30S
POSSIBLE.
WEATHER SYSTEM EJECTS EAST FROM THE SOUTHERN PLAINS INTO THE TN
VALLEY FRI/SAT AND KEEPS THE BRUNT OF ITS SHOWERS SOUTH OF CENTRAL
IL. GFS HAS TRENDED FURTHER SOUTH WITH THE QPF FIELDS AND MORE
CONFIDENCE OF A DRY FORECAST ON FRIDAY WITH HIGHS IN THE LOWER 60S.
HAVE 20-30% CHANCE OF SHOWERS FROM I-70 SOUTH FRIDAY NIGHT AND SAT
WITH HIGHEST POPS IN SE IL WITH THUNDER CHANCES STAYING SOUTH OF I-64.
HIGHS SAT IN THE MID 60S.
LONG TERM...SATURDAY NIGHT THROUGH TUESDAY NIGHT
GENERALLY DRY AND MILDER WEATHER EXPECTED SUNDAY AND MONDAY AS
SYSTEM EXITS EAST OF IL SUNDAY...WITH HIGHS AROUND 70F SUNDAY
AND MID 70S MONDAY. GFS BRINGS PATCHES OF LIGHT QPF INTO IL SUNDAY
BUT THINK THIS WILL BE MORE TO OUR SE AS UPPER LEVEL RIDGE
BUILDING INTO IL. AN UPPER LEVEL TROF DIGGING INTO THE NORTHERN
PLAINS TUE TO PUSH A FRONTAL BOUNDARY SE INTO IA TUE WITH GFS
QUICKER WITH COLD FRONT THAN ECMWF. WILL GO WITH ALLBLEND SLIGHT
CHANCE POPS OF SHOWERS AND THUNDERSTORMS TUE AND TUE NIGHT. STILL
IN THE 70S FOR HIGHS TUE WITH CENTRAL/SE IL AHEAD OF THE COLD
FRONT.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PADUCAH KY
653 AM CDT WED APR 24 2013
.UPDATE...
ISSUED AT 652 AM CDT WED APR 24 2013
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 12Z TAF ISSUANCE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 336 AM CDT WED APR 24 2013
BOTH THE SURFACE COLD FRONT AND THE MAIN POST-FRONTAL BAND OF
SHOWERS AND THUNDERSTORMS ARE TAKING THEIR SWEET TIME TONIGHT. AS
OF 08Z...THE COLD FRONT WAS LOCATED FROM NEAR FT CAMPBELL TO NEAR
GREENVILLE KENTUCKY...AND THE BAND OF CONVECTION WAS LOCATED ALONG
AND NORTHWEST OF A LINE FROM DONIPHAN MISSOURI TO MARION AND MT
CARMEL ILLINOIS. WATER VAPOR IMAGERY SHOWS THE MAIN MID/UPPER
LEVEL IMPULSE PIVOTING EASTWARD OVER THE SOUTHERN/CENTRAL PLAINS.
THIS SHOULD HELP TO GIVE THE MAIN BAND A GOOD PUSH...AND MAY CAUSE
IT TO PIVOT TO MORE OF A SOUTH SOUTHWEST TO NORTH NORTHEAST
ORIENTATION THROUGH SUNRISE.
USED THE LATEST RAP AS A GUIDE FOR HOURLY POP GRIDS THROUGH THE
END OF THE EVENT. SHOULD SEE THE MAIN BAND PUSH SOUTHWARD TOWARD
THE OHIO RIVER THROUGH SUNRISE...AND THEN GRADUALLY COME TO AN END
FROM WEST TO EAST THROUGH THE MORNING. SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS WILL CONTINUE IN THE VICINITY OF THE
FRONT IN THE SOUTHERN PENNYRILE THROUGH DAYBREAK...BUT THE MAIN
BAND MAY NOT QUITE GET DOWN THAT FAR SOUTHEAST BEFORE BEING FORCED
EAST OF THE AREA.
THE SURFACE HIGH WILL PUSH EASTWARD ACROSS THE AREA THROUGH THE
DAY WHICH SHOULD LEAD TO A NICE CLEARING TREND AND DIMINISHING
WINDS. WINDS WILL GO NEARLY CALM THIS EVENING AS THE SURFACE HIGH
BRIEFLY SETTLES OVER THE REGION. BUT OVERNIGHT...A WEAK SURFACE
TROUGH ASSOCIATED WITH A CLIPPER SYSTEM DIVING THROUGH THE GREAT
LAKES WILL INDUCE SOUTHWEST WIND MAINLY OVER THE NORTHERN HALF OF
THE AREA. FEEL THAT MOST PLACES WILL DROP TO THE MID 30S FOR LOWS
TONIGHT...BUT THE WIND SHOULD KEEP FROST FROM BEING DEPOSITED LATE
TONIGHT. THE MOST LIKELY PLACE TO SEE SOME FROST MAY VERY WELL BE
OVER THE SOUTHERN HALF OF THE AREA. DO NOT HAVE ANY FROST IN THIS
FORECAST...BUT MAY NEED TO ADD IT IN IF CONFIDENCE INCREASES TODAY.
THE NAM GENERATES SOME RATHER GUSTY NORTHWEST WINDS BEHIND THE
CLIPPER SYSTEM THURSDAY...ESPECIALLY OVER THE NORTHEAST. INCREASED
WINDS SOME...BUT DID NOT GO UP TO NAM LEVELS AT THIS TIME.
SURFACE HIGH PRESSURE WILL DOMINATE THE REGION AGAIN FOR MOST OF
THURSDAY NIGHT. IT WILL GRADUALLY PUSH EAST OF THE AREA WHICH MAY
ALLOW FOR A LIGHT SOUTHEAST WIND TO DEVELOP LATE IN THE WEST. THE
MODELS ALSO SHOW SOME INCREASE IN CLOUD COVER IN THE WEST LATE
THURSDAY NIGHT. THE BOTTOM LINE IS THE POTENTIAL FOR TEMPERATURES
TO DROP INTO THE 30S AGAIN...ESPECIALLY EAST OF THE MISSISSIPPI
RIVER. OF COURSE WILL HAVE TO WATCH FOR FROST POTENTIAL AS WELL.
THE MODELS SEEM TO BE TRENDING SLOWER AND FARTHER SOUTH WITH THE
QPF ASSOCIATED WITH THE RATHER WEAK MID-LEVEL TROUGH PUSHING OUT
OF THE SOUTHERN/CENTRAL PLAINS FRIDAY. LOWERED POPS AND CONFINED
GOOD CHANCE POPS TO SOUTHEAST MISSOURI IN THE AFTERNOON ONLY.
LOOKS LIKE IT WILL BE MORE OF A STRATIFORM EVENT SO JUST MENTIONED
RAIN.
AS FOR TEMPERATURES...STAYED NEAR CONSENSUS OF GUIDANCE FOR HIGHS
TODAY...BUT IN GENERAL FEEL THAT THE LOW END OF GUIDANCE IS THE
PLACE TO BE FOR TONIGHT THROUGH FRIDAY. THE LONE EXCEPTION IS IN
THE SOUTHWEST THURSDAY NIGHT...IF CLOUDS OR WINDS INCREASE.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 336 AM CDT WED APR 24 2013
WHILE STILL NOT COMPLETELY IN SYNC...LATEST MODEL OUTPUT HAS COME
INTO BETTER ALIGNMENT WITH RESPECT TO THE SOUTHERN STREAM ENERGY
FORECAST TO IMPACT THE REGION LATE IN THE WEEK. THERE IS CERTAINLY
A TREND TO SHIFT THE MAIN FOCUS FOR PRECIPITATION TO THE SOUTH OF
THE IMMEDIATE FORECAST AREA...MUCH AKIN TO WHAT THE ECMWF HAS BEEN
INDICATING. THE SURFACE BOUNDARY IS NOW FORECAST BY ALL MODELS TO
REMAIN SOUTH OF THE REGION...WHICH KEEPS SURFACE BASED INSTABILITY
AT BAY. TO THAT EXTENT...ELEVATED INSTABILITY PARAMETERS ARE ALSO
LACKING WITH THIS SYSTEM. THE END RESULT WAS TO ELIMINATE THE
MENTION OF THUNDER FROM THE FRIDAY NIGHT/SATURDAY FORECAST.
THE HIGHEST LIKELIHOOD FOR RAIN SHOWERS STILL APPEARS TO BE FRIDAY
NIGHT INTO EARLY SATURDAY...WITH BETTER CHANCES SOUTH...SMALLER
CHANCES NORTH. EXCEPT FOR THE GFS...MODELS ARE ALSO TRENDING DRIER
LATE IN THE WEEKEND. KEPT SMALL CHANCES FOR SHOWERS OVER FAR EASTERN
AREAS SATURDAY NIGHT AND SUNDAY AS THIS AREA WILL BE ON THE WESTERN
PERIPHERY OF THE DEPARTING ENERGY.
HIGH PRESSURE RIDGING IS FORECAST TO STRENGTHEN OVER THE EASTERN
U.S. EARLY NEXT WEEK. CONSIDERING THE AMPLITUDE OF THIS RIDGE...THE
GFS MAY BE TOO QUICK WITH THE APPROACH OF THE NEXT TROUGH AND ITS
ASSOCIATED PRECIPITATION POTENTIAL. MAINTAINED SLIGHT CHANCE POPS IN
THE TUESDAY FORECAST FOR NOW...BUT WOULD NOT BE SURPRISED TO SEE IT
PUSHED TO LATER PERIODS PER THE 00Z ECMWF. A SLOW WARMING TREND IS
EXPECTED THROUGH THE PERIOD.
&&
.AVIATION...
ISSUED AT 652 AM CDT WED APR 24 2013
THE BACK EDGE OF THE PRECIPITATION IS CLEARING KCGI NOW...AND IT
SHOULD CONTINUE EASTWARD CLEARING ONE SITE AND HOUR THROUGH 15Z.
PREVAILING MVFR AND TEMPO IFR CONDITIONS IN RAIN CAN BE EXPECTED
AT ALL SITES. IFR CEILINGS MAY BE MORE PREVALENT AT KEVV AND
KOWB...AND KOWB WILL LIKELY KEEP AN IFR CEILING THROUGH THE
MORNING AFTER THE PRECIPITATION ENDS.
WILL SEE GRADUAL IMPROVEMENT IN CEILINGS FROM WEST TO EAST
THROUGH THE DAY. ALL TERMINALS SHOULD BE CLEAR BY AROUND 00Z.
GUIDANCE SUGGESTS THAT GUSTY NORTHWEST WINDS WILL BE STRONGEST
THIS MORNING AND THEN DIMINISH THROUGH THE AFTERNOON. WOULD EXPECT
ALL TERMINALS TO QUICKLY BECOME CALM WITH/BY SUNSET. A LIGHT
SOUTHWEST WIND IS LIKELY TO DEVELOP OVERNIGHT AT KEVV AND
KOWB. NOT SURE IF A TANGIBLE SOUTHWEST WIND WILL DEVELOP FARTHER
TO THE SOUTHWEST. GIVEN THE DRY ADVECTION EXPECTED THROUGH THE
DAY...WILL NOT MENTION ANY FOG FORMATION LATE TONIGHT...DESPITE
GOOD RADIATIONAL COOLING CONDITIONS FOR MUCH OF THE NIGHT
FOLLOWING THIS MORNINGS RAINFALL. SOME FOG MAY NEED TO BE ADDED
IN LATER FORECASTS.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...DRS
LONG TERM...RP
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
701 AM EDT WED APR 24 2013
.AVIATION...
//DISCUSSION...
PRECIPITATION WILL CONTINUE TO TAPER OFF EARLY THIS MORNING. LIGHT
RAIN IS EXPECTED TO REDEVELOP OVER SE MI IN THE 15Z TO 18Z TIME
FRAME AS AN UPPER WAVE LIFTS TOWARD THE OHIO VALLEY. THIS RAINFALL
WILL THEN END FROM WEST TO EAST LATER IN THE AFTERNOON AS MUCH DRIER
AIR PUSHES IN FROM THE WEST. THE INITIAL IFR CEILINGS IN THE POST
FRONTAL ENVIRONMENT THIS MORNING WILL SLOWLY LIFT OVER THE NEXT
SEVERAL HOURS AS DRYER AIR BELOW 3000 FT CONTINUES TO ADVECT INTO
THE REGION FROM THE NORTHWEST.
FOR DTW...WHILE THERE IS SOME POTENTIAL FOR IFR CEILINGS TO PERSIST
OFF AND ON INTO THE EARLY AFTERNOON...THE OVERALL TRENDS WILL BE
TOWARD RISING CEILINGS DESPITE AN ADDITIONAL ROUND OF LIGHT RAIN
DEVELOPING LATE THIS MORNING/EARLY THIS AFTERNOON.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FT THROUGH LATE AFTERNOON.
&&
.PREV DISCUSSION...ISSUED 350 AM EDT WED APR 24 2013
SHORT TERM...TODAY AND TONIGHT
BY FORECAST ISSUANCE TIME...WEAK SFC LOW PRESSURE AND A COLD FRONT
WILL BE PUSHING EAST OF METRO DETROIT AND PORT HURON. THERE HAS BEEN
A FAIRLY WIDESPREAD AREA OF RAINFALL ACROSS SE MI ALONG AND BEHIND
THE SFC FRONT LAST NIGHT WITHIN A REGION OF STRONG LOWER
TROPOSPHERIC FRONTOGENESIS. THE HEAVIER AND MORE PERSISTENT RAINFALL
HAS OCCURRED WITHIN THE 800-700MB LAYER OF THE FRONTAL SLOPE. THIS
TARGETED THE TRI CITIES AND SAGINAW BAY REGION WHERE RADAR
ESTIMATED RAINFALL IS ALREADY AROUND AN INCH. THE REGION OF HIGHER
INTENSITY RAINFALL IS EXPECTED TO SHIFT INTO THE THUMB REGION DURING
THE EARLY MORNING HOURS. GIVEN THE ESTIMATED RAINFALL AND WITH THE
EXPECTATION FOR HIGHER INTENSITY RAINFALL TO PUSH INTO THE
THUMB...THE FLOOD WATCH WILL BE CONTINUED THROUGH DAYBREAK. THERE
HAVE BEEN A FEW AWOS SITES WHICH HAVE REPORTED SNOW OVERNIGHT...
WHICH IS INCORRECT. ALL PRECIP THUS FAR HAS BEEN IN THE FORM OF
RAIN. THE NAM AND GFS SOLUTIONS APPEAR TOO COOL IN THE BOUNDARY
LAYER THIS MORNING IN COMPARISON TO OBSERVATIONS...WITH THE RAP
SOUNDINGS APPEARING TO HAVE A BETTER HANDLE ON THE LOW LEVEL THERMAL
PROFILES. THE RAP IS SUGGESTIVE OF PRECIP REMAINING MOSTLY RAIN THIS
MORNING...EXPECT ACROSS THE TRI CITIES AND THUMB WHERE COLDER AIR
CONTINUES TO FILTER IN FROM THE NW AND IS LIKELY TO CAUSE A MIX OR
BRIEF CHANGE OVER TO SNOW.
THE LOW TO MID LEVEL FGEN RESPONSE WILL WEAKEN TOWARD DAYBREAK
THROUGH LATE MORNING DUE TO THE LOW LEVEL THERMAL GRADIENT RELAXING
AS SFC LOW PRESSURE AND BETTER UPPER DYNAMICS SHIFT OFF TO THE
NORTHEAST. THIS WILL LEAD TO A STEADY DECREASE IN COVERAGE AND
INTENSITY OF THE RAINFALL. HOWEVER...THE UPPER LEVEL WAVE NOTED OVER
KANSAS IS FORECAST TO RAPIDLY LIFT ACROSS THE NRN OH VALLEY AND ERN
GREAT LAKES THIS AFTERNOON. MODEL SOLUTIONS HAVE TRENDED TOWARD A
DEEPER UPPER WAVE/STRONGER UPPER LEVEL POTENTIAL VORTICITY ADVECTION
WITH THIS FEATURE AND APPEAR WELL INITIALIZED. AS IT LIFTS NE THIS
AFTERNOON...SOME WEAK MID LEVEL DEFORMATION WILL OVERSPREAD SE MI...
ESPECIALLY THE EASTERN HALF OF THE FORECAST AREA. AN INTENSIFICATION
OF AN UPPER JET STREAK WILL OCCUR ACROSS LOWER MI AND LAKE HURON AS
WELL...WITH INCREASING DIVERGENCE OVERSPREADING OHIO...LAKE ERIE AND
FAR EASTERN PORTIONS OF SE MI. THIS FORCING WILL INTERACT WITH THE
BACK EDGE OF THE DEEPER MOISTURE PLUME OVER SE MI...SUGGESTING
RAINFALL WILL INCREASE IN COVERAGE AGAIN DURING THE AFTERNOON. THE
RATHER MARGINAL FORCING SUGGEST ADDITIONAL DAYTIME RAINFALL AMOUNTS
WILL GENERALLY REMAIN BELOW A QUARTER INCH. THE EXPECTATION FOR
ENOUGH DAYTIME WARMING IN THE BOUNDARY LAYER SUPPORTS PRECIP TYPE AS
ALL RAIN TODAY. ALTHOUGH WITH 850MB TEMPS FORECAST TO DROP TO
-5C...THERE WAS SOME SERIES CONTEMPLATION OVER ADDING A MENTION OF
SOME SNOW NORTH OF METRO DETROIT.
THE EXTENT OF CLOUDS AND RAIN TODAY...WITH DWPTS DROPPING INTO THE
LOW 30S...WILL SUPPRESS TEMPS TO THE MID 30S TO LOWER 40S WELL INTO
THE AFTERNOON. A PUSH OF DRIER AIR LATE IN THE AFTERNOON AND EVENING
WILL END THE RAIN AND CAUSE SOME PARTIAL CLEARING WHICH SHOULD ALLOW
A LATE DAY SPIKE IN TEMPS INTO THE MID-UPPER 40S. PARTIAL CLEARING
TONIGHT AMIDST SHORT WAVE RIDGING WILL ALLOW ENOUGH OPPORTUNITY FOR
NIGHTTIME COOLING TO DROP TEMPS WELL DOWN INTO THE 30S.
LONG TERM...THURSDAY THROUGH TUESDAY
STRONG UPPER WAVE OVER SASKATCHEWAN WILL DIVE DOWN INTO THE WESTERN
GREAT LAKES BY THURSDAY MORNING...AS IT ROTATES WITHIN THE LONGWAVE
TROUGH OVER THE CENTRAL U.S. AND CANADA. THIS WAVE WILL CLIP QUICKLY
ACROSS LOWER MICHIGAN AND INTO ONTARIO THURSDAY...PUSHING A WEAK LOW
PRESSURE SYSTEM ACROSS THE NORTHERN GREAT LAKES AND DRAGGING A COLD
FRONT ACROSS THE AREA. FRONTAL TIMING CONTINUES TO VARY WITHIN THE
MODELS...AND STRONG PREFERENCE GOES TO THE VERY CONSISTENT EURO
MODEL. GOOD BURST OF LIFT WILL ACCOMPANY THE COLD FRONT...WITH
FRONTAL DYNAMICS STACKED UNDERNEATH MID-LEVEL PVA AND LEFT EXIT
REGION FORCING. COLD AIR ALOFT REMAINING IN PLACE BEHIND TODAY`S
SYSTEM IN COMBINATION WITH H500 TEMPS DROPPING TO ABOUT -35C WITH
THE UPPER WAVE...WHICH HAS ARCTIC ORIGINS...WILL CREATE VERY
MODERATELY STEEP LOW AND MID-LEVEL LAPSE RATES (FROM SURFACE UP
THROUGH 400MB). DEEP LAYER OF INSTABILITY WILL HELP MAXIMIZE
RESPONSE FROM FORCING AND MAKE THE BEST OF ONLY MEAGER MOISTURE
(SHALLOW LAYER OF MOISTURE POOLING AHEAD OF FRONT WITH SPECIFIC
HUMIDITY 3 G/KG AND PW OVERALL ONLY AROUND 0.4 INCHES).
PRECIPITATION ASSOCIATED WITH THE FRONT WILL AFFECT THE AREA DURING
THE FIRST HALF OF THURSDAY...WITH ADDITIONAL SHOWERS POSSIBLY
REDEVELOPING DURING THE LATE AFTERNOON AS LAPSE RATES FURTHER
STEEPEN AND SOME MOISTURE LINGERS. PRECIPITATION TYPE IS STILL A
LITTLE UNCERTAIN WITH GFS/NAM FORECAST SOUNDINGS STILL HINTING THAT
SNOW MAY BE POSSIBLE...BUT GIVEN WARMER EURO PROFILES IN THE PAST
TWO MODEL RUNS...WILL KEEP PRECIP TYPE AS RAIN. WOULD ALSO EXPECT TO
SEE SOME GRAUPEL FALL AS SHOWERS WILL HAVE A CONVECTIVE ELEMENT TO
THEM AND FREEZING LEVELS WILL BE VERY LOW.
SURFACE HIGH PRESSURE WILL EXPAND INTO THE AREA FROM THE OHIO VALLEY
THURSDAY NIGHT AND FRIDAY BRINGING DRY WEATHER BACK TO THE AREA. LOW
PRESSURE TRACKING ACROSS HUDSON BAY WILL DRAW SOME WARMER AIR UP
INTO THE REGION ON FRIDAY...ALLOWING TEMPERATURES TO CREEP BACK UP
INTO THE UPPER 50S.
WEEKEND WILL BE MARKED BY ZONAL FLOW...WITH UPPER RIDGING BUILDING
INTO THE GREAT LAKES MONDAY AND TUESDAY IN RESPONSE TO TROUGHING
DROPPING DOWN INTO THE NORTHERN ROCKIES. WILL SEE A WARMING TREND
DURING THIS STRETCH...WITH MAX TEMPERATURES GRADUALLY WARMING TO
AROUND 70. MODELS HAVE BEEN TRYING TO GENERATE CONVECTION JUST ABOUT
EVERY AFTERNOON AS LAPSE RATES STEEPEN DURING THE DAY. GIVEN GENERAL
LACK OF GOOD MOISTURE ADVECTION (HAVE A FEELING SURFACE TD`S ARE TOO
HIGH AS WELL) AND EVENTUAL CAPPING FROM THE RIDGE...ELECTED TO KEEP
THE FORECAST DRY AND THUNDERSTORM FREE FOR NOW.
MARINE...
NORTHWEST WINDS IN THE WAKE OF LAST NIGHTS COLD FRONTAL PASSAGE HAS
USHERED IN COLDER AIR...LEADING TO UNSTABLE CONDITIONS OVER THE
LAKES. SOME GUSTS UP TO 25 KNOTS ARE EXPECTED OVER THE OPEN WATERS
OF LAKE HURON. THESE CONDITIONS SHOULD BE SHORT LIVED AS HIGH
PRESSURE BUILDS IN FROM THE WEST LATE THIS AFTERNOON AND ALLOWS
WINDS AND WAVES TO RELAX. A FAST MOVING LOW PRESSURE SYSTEM WILL
THEN TRAVERSE THE REGION ON THURSDAY. THE GRADIENT WILL NOT BE TOO
TERRIBLE STRONG...BUT COULD LEAD TO SOME GUSTS UP TO 25 KNOTS OVER
LAKES ST CLAIR...ERIE AND THE SOUTHERN BASIN OF LAKE HURON.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT
HURON...UNTIL 5 PM WEDNESDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....SC
SHORT TERM...SC
LONG TERM....HLO
MARINE.......SC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1139 AM EDT WED APR 24 2013
.SYNOPSIS...
SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL OCCUR LATE TODAY AND
INTO THIS EVENING AS A STRONG COLD FRONT PASSES THROUGH THE AREA.
BEHIND THIS FEATURE...DRY CONDITIONS ARE EXPECTED ON THURSDAY WITH
THE NEXT ROUND OF SHOWERS POSSIBLE THURSDAY NIGHT AND EARLY FRIDAY
AS ANOTHER WEAK WAVE WILL PASSES OVERHEAD. FAIR AND PLEASANT
CONDITIONS ARE THEN EXPECTED FOR THE WEEKEND AS STRONG HIGH
PRESSURE BUILDS INTO THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
1115 AM UPDATE...
A WEAK WARM FRONT MOVING THROUGH THE REGION THIS MORNING HAS
PRODUCED A FAIR AMOUNT OF CLOUD COVER ALONG WITH SPRINKLES OVER
CENTRAL NEW YORK AND THE NORTHERN TIER OF PA. IT HAS ALSO KEPT
SFC TEMPS LOWER THAN EXPECTED WITH MAXES NOW RANGING FROM THE
MID/UPPER 60S. COLD FRONT HAS JUST CROSSED CLEVELAND WITH
WIDESPREAD SHOWERS JUST AHEAD AND MAINLY BEHIND BOUNDARY. LATEST
MODEL GUIDANCE CONTINUES TO SHOW SEVERAL HUNDRED J/KG OF CAPE
LATER THIS AFTERNOON PRIMARILY ACROSS THE SOUTHERN TIER OF NYS AND
NE PA. WITH THE AMOUNT OF CLOUD COVER IT WILL BE INTERESTING TO SEE
IF THIS MUCH CAPE IS REALIZED. MODEL SOUNDINGS DO SHOW PRETTY GOOD
MID LEVEL LAPSE RATES SO IF ENOUGH FRONTAL LIFT IS GENERATED THIS
INSTABILITY COULD BE TAPPED. IF ENOUGH INSTABILITY IS REALIZED
THE CURRENT WIND FIELD AND SHEAR VALUES WOULD SUPPORT A FEW
STRONGER CELLS WITH THE POTENTIAL FOR A FEW SEVERE THUNDERSTORMS.
CURRENT FORECAST IN GOOD SHAPE WILL CONTINUE WITH CATEGORICAL POPS
FOR SHOWERS DURING FROPA AND CHC POPS FOR THUNDERSTORMS.
630 AM UPDATE...
QUICK UPDATE TO ACCOUNT FOR LATEST RADAR TRENDS TO OUR WEST.
REGIONAL RADARS NOW SHOWING AN INITIAL BAND OF LGT RAIN SHWRS
WORKING INTO WESTERN NY THIS HR...WHICH APPEARS TO BE THE RESULT
OF WEAK ISENTROPIC ASCENT ALONG/NORTH OF DIFFUSE WARM FRONT. THAT
SAID...HAVE UPDATED GRIDS TO BRING IN RAIN A FEW HRS EARLIER
ACROSS THE WESTERN AND NORTHERN ZONES. NO OTHER CHANGES NEEDED AT
THE PRESENT TIME.
PREVIOUS NEAR TERM DISCUSSION...
A CHALLENGING FCST TO SAY THE LEAST TODAY AS A STRONG COLD FRONT
WILL PLOW THROUGH THE REGION DURING THE LATE AFTERNOON AND EARLY
EVENING HRS. THE MAIN DIFFICULTIES ARE TWOFOLD WITH THE FIRST
BEING THE DEGREE OF WARMING PROCEEDING THE FRONT...AND THE SECOND
CONCERNING SEVERE WX POTENTIAL AS THE FRONT BARRELS THROUGH THE
REGION. FIRST THINGS FIRST HOWEVER AND WE SHOULD PROBABLY START
WITH A GENERAL SYNOPTIC OVERVIEW.
EARLY MORNING WATER VAPOR CLEARLY SHOWING A DEEP TROUGH OF LOW
PRESSURE DIGGING ACROSS THE SOUTHERN PLAINS THIS MORNING WITH
BROAD CYCLONIC FLOW PREVAILING OVER THE NATION/S MIDSECTION.
ACROSS OUR REGION...WEAK UPPER RIDGING THAT BROUGHT SUCH NICE
WX TO OUR AREA YESTERDAY NOW DEPARTING TO OUR EAST AS UPPER TROUGH
AND ASSOCIATED DEFORMATION AXIS WITH THE WESTERN ATLANTIC COASTAL
LOW WORK OFF THE NEW ENGLAND COAST. WITH TIME TODAY...COLD FRONT
ASSOCIATED WITH THE CENTRAL US TROUGH WILL ADVANCE EAST OVER OUR
REGION BY THIS AFTERNOON BRINGING WITH IT A PERIOD OF SHWRS AND
STORMS TO MUCH OF OUR AREA.
AS FOR THE SEVERE WX POTENTIAL...MODELS REMAIN ALL OVER THE PLACE
WITH RESPECT TO THE DEGREE OF DESTABILIZATION THAT WILL OCCUR
PRIOR TO FROPA LATER TODAY. THE NAM REMAINS THE MOST UNSTABLE
SOLUTION THIS MORNING WITH AWIPS PLAN VIEW MAPS SHOWING A NARROW
CORRIDOR OF MLCAPE VALUES RANGING FROM 400-500 J/KG IMMEDIATELY
PROCEEDING THE FRONT MAINLY WEST OF THE I-81 CORRIDOR. THIS IS
PERPLEXING TO SOME DEGREE AS CORRESPONDING NAM BUFKIT SOUNDINGS
FOR ELM AND OTHER WESTERN FCST POINT LOCATIONS ADVERTISE MUCH
LOWER VALUES. THE GFS SEEMS TO AGREE WITH THE WEAKER NAM BUFKIT
SOLUTIONS...AS DOES THE LATEST RUC AND LOCALLY RUN WRF MODELS. AS
FOR THE KINEMATICS...WIND FIELDS ALOFT REMAIN IMPRESSIVELY STRONG
WITH 0-6 KM BULK SHEAR VECTORS RANGING FROM 40 TO 50 KTS ACROSS
THE REGION WHILE 0-3 KM BULK SHEAR VALUES ARE JUST AS HIGH. THIS
SUGGESTS THAT IF SEVERE WX WERE TO DEVELOP...DAMAGING WIND GUSTS
WOULD BE THE BIGGEST THREATS IF ANY DEVELOPING CONVECTION WERE TO
MORPH INTO A WELL-DEFINED SQUALL LINE OR SHORT BOWING SEGMENTS. THIS
AGREES WELL WITH LOCAL SEVERE WX CHECKLIST WHICH SUGGEST A
SIGNIFICANT COOL SEASON WIND EVENT IS POSSIBLE HOWEVER ITS HARD TO
GET BY LATEST MODEL TRENDS OF VERY MODEST DESTABILIZATION.
CONSIDERING THE AMOUNT OF CLOUD COVER THAT WILL LIKELY BEGIN
MOVING OVERHEAD THIS MORNING COUPLED WITH THE FACT THAT RETURN
FLOW MOISTURE WILL BE MEAGER AT BEST (AFTERNOON DEWPOINT TEMPS
ONLY CLIMBING INTO THE MIDDLE TO UPPER 40S)...WE/RE INCLINED TO
BELIEVE THAT SEVERE WX POTENTIAL WILL BE FAIRLY LIMITED. THIS
AGREES WELL WITH THE LATEST SPC DAY 1 OUTLOOK WHICH ONLY
ADVERTISES GENERAL THUNDER MENTION ACROSS OUR REGION ("SEE TEXT" TO
OUR SOUTHWEST). ALTHOUGH WE TOTALLY CANNOT RULE OUT SEVERE WX
LATER TODAY...WE DO NOT THINK THAT THE FCST REGION WILL BE DEALING
WITH A WIDESPREAD SEVERE WX EVENT AT THIS TIME.
NOW TO THE NEXT ISSUE...THE HIGH TEMP FCST FOR TODAY. UPSTREAM OBS
FROM THE UPPER OHIO VLY SHOW TEMPS IN THE LOWER 60S AS CLOSE AS
CLEVELAND EARLY THIS MORNING. CONSIDERING THIS AIR WILL TRAVEL
EAST OVER OUR REGION...WE/RE INCLINED TO BELIEVE TEMPS WILL WARM
INTO THE UPPER 60S TO LOWER 70S AHEAD OF THE FRONT TODAY. ONLY
ITEM OF CONCERN IS THE LATEST SATELLITE TRENDS WHICH SHOW ENHANCED
CLOUD COVER APPROACHING FROM NORTHERN OHIO THIS MORNING. DESPITE
THIS HOWEVER...DEGREE OF THERMAL ADVECTION WILL LIKELY BE ENOUGH
TO OVERCOME LIMITED COOLING ASSOCIATED WITH INCREASING CLOUDS
ALOFT.
BY TONIGHT...COLD FRONT TO EXIT OFF TO THE EAST WITH TIME BETWEEN
00 AND 06Z. RAIN SHOULD GRADUALLY COME TO AN END WITH TIME WITH
STRONG COLD AIR ADVECTION EXPECTED IN ITS WAKE. AS A
RESULT...TEMPS WILL DROP INTO THE LOWER TO MIDDLE 30S ACROSS MUCH
OF THE REGION WITH GUSTY WINDS EXPECTED THROUGH A GOOD PORTION OF
THE OVERNIGHT HRS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
COOLER TEMPS EXPECTED BOTH THU AND FRI AS COOL HIGH PRESSURE
BUILDS IN FOLLOWING FROPA LATER TONIGHT. WITH H85 TEMPS QUICKLY
FALLING TO NEAR ZERO CELSIUS...HIGH TEMPS ON THU ONLY LOOK TO
WARM INTO THE LOWER TO MIDDLE 50S AT BEST. SLIGHTLY WARMER TEMPS
EXPECTED ON FRI AS HIGH PRESSURE ADVANCES TO THE EAST WITH UPPER
50S TO LOWER 60S AGAIN POSSIBLE. WEAK UPPER WAVE WILL PASS ACROSS
THE REGION THU NGT/EARLY FRI BRINGING THE NEXT ROUND OF SHWRS TO
THE AREA.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
300 PM UPDATE...
SHAPING UP TO BE A BEAUTIFUL EXTENDED PERIOD WITH HIGH PRESSURE
CENTERED OVER US TO START THE PERIOD THEN SHIFTING EAST BUT STILL
IN CONTROL THROUGH EARLY NEXT WEEK. THE PATTERN IS RATHER STAGNANT
SO WHILE WE WILL SEE TEMPS WARM INTO THE 60S DURING THIS
TIME...THE TRUE STRONG WAA AND ASSOCIATED VERY WARM AIR WILL
REMAIN WELL TO OUR WEST. SOME UNCERTAINTY DOES CREEP IN FROM
SUNDAY NIGHT AND BEYOND AS BOTH THE EURO AND GFS SHOW AN AXIS OF
MOISTURE JUST TO OUR WEST THROUGH THE OHIO VALLEY. THE GFS HINTS
THAT WE MAY SEE SOME SHOWERS ESPECIALLY OVER THE FAR WESTERN
FINGER LAKES DURING THIS TIME WHILE THE EURO IS MUCH DRIER.
SOMETHING TO WATCH CAREFULLY BUT FOR NOW WILL KEEP MOST OF THE
AREA DRY.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDS TODAY AHD OF A COLD FNT APRCHG THE AREA FROM WEST. FNT WILL
BRING SHWRS AND ISLTD TRW STARTING ARND 21Z AND CONTG THRU ARND
00Z. MVFR CIGS AND VSBYS WITH THE SHWRS...ALONG WITH GUSTY WINDS.
BHD THE FNT...CAA WILL BRING MVFR CIGS ALONG WITH SPOTTY MVFR
VSBYS IN SHWRS. DRIER AIR WELL BHD THE FNT WILL RETURN SOME
LOCATIONS TO VFR BEFORE THE END OF THE TAF PD.
OUTLOOK...
THU THRU SUN...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG/RRM
NEAR TERM...CMG/RRM
SHORT TERM...CMG
LONG TERM...HEDEN
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
640 AM EDT WED APR 24 2013
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TODAY AS A STRONG COLD
FRONT PASSES ACROSS THE AREA. BEHIND THIS FEATURE...DRY
CONDITIONS ARE EXPECTED ON THURSDAY WITH THE NEXT ROUND OF
SHOWERS POSSIBLE THURSDAY NIGHT AND EARLY FRIDAY AS ANOTHER WEAK
WAVE WILL PASSES OVERHEAD. FAIR AND PLEASANT CONDITIONS ARE THEN
EXPECTED FOR THE WEEKEND AS STRONG HIGH PRESSURE BUILDS INTO THE
AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
630 AM UPDATE...
QUICK UPDATE TO ACCOUNT FOR LATEST RADAR TRENDS TO OUR WEST.
REGIONAL RADARS NOW SHOWING AN INITIAL BAND OF LGT RAIN SHWRS
WORKING INTO WESTERN NY THIS HR...WHICH APPEARS TO BE THE RESULT
OF WEAK ISENTROPIC ASCENT ALONG/NORTH OF DIFFUSE WARM FRONT. THAT
SAID...HAVE UPDATED GRIDS TO BRING IN RAIN A FEW HRS EARLIER
ACROSS THE WESTERN AND NORTHERN ZONES. NO OTHER CHANGES NEEDED AT
THE PRESENT TIME.
PREVIOUS NEAR TERM DISCUSSION...
A CHALLENGING FCST TO SAY THE LEAST TODAY AS A STRONG COLD FRONT
WILL PLOW THROUGH THE REGION DURING THE LATE AFTERNOON AND EARLY
EVENING HRS. THE MAIN DIFFICULTIES ARE TWOFOLD WITH THE FIRST
BEING THE DEGREE OF WARMING PROCEEDING THE FRONT...AND THE SECOND
CONCERNING SEVERE WX POTENTIAL AS THE FRONT BARRELS THROUGH THE
REGION. FIRST THINGS FIRST HOWEVER AND WE SHOULD PROBABLY START
WITH A GENERAL SYNOPTIC OVERVIEW.
EARLY MORNING WATER VAPOR CLEARLY SHOWING A DEEP TROUGH OF LOW
PRESSURE DIGGING ACROSS THE SOUTHERN PLAINS THIS MORNING WITH
BROAD CYCLONIC FLOW PREVAILING OVER THE NATION/S MIDSECTION.
ACROSS OUR REGION...WEAK UPPER RIDGING THAT BROUGHT SUCH NICE
WX TO OUR AREA YESTERDAY NOW DEPARTING TO OUR EAST AS UPPER TROUGH
AND ASSOCIATED DEFORMATION AXIS WITH THE WESTERN ATLANTIC COASTAL
LOW WORK OFF THE NEW ENGLAND COAST. WITH TIME TODAY...COLD FRONT
ASSOCIATED WITH THE CENTRAL US TROUGH WILL ADVANCE EAST OVER OUR
REGION BY THIS AFTERNOON BRINGING WITH IT A PERIOD OF SHWRS AND
STORMS TO MUCH OF OUR AREA.
AS FOR THE SEVERE WX POTENTIAL...MODELS REMAIN ALL OVER THE PLACE
WITH RESPECT TO THE DEGREE OF DESTABILIZATION THAT WILL OCCUR
PRIOR TO FROPA LATER TODAY. THE NAM REMAINS THE MOST UNSTABLE
SOLUTION THIS MORNING WITH AWIPS PLAN VIEW MAPS SHOWING A NARROW
CORRIDOR OF MLCAPE VALUES RANGING FROM 400-500 J/KG IMMEDIATELY
PROCEEDING THE FRONT MAINLY WEST OF THE I-81 CORRIDOR. THIS IS
PERPLEXING TO SOME DEGREE AS CORRESPONDING NAM BUFKIT SOUNDINGS
FOR ELM AND OTHER WESTERN FCST POINT LOCATIONS ADVERTISE MUCH
LOWER VALUES. THE GFS SEEMS TO AGREE WITH THE WEAKER NAM BUFKIT
SOLUTIONS...AS DOES THE LATEST RUC AND LOCALLY RUN WRF MODELS. AS
FOR THE KINEMATICS...WIND FIELDS ALOFT REMAIN IMPRESSIVELY STRONG
WITH 0-6 KM BULK SHEAR VECTORS RANGING FROM 40 TO 50 KTS ACROSS
THE REGION WHILE 0-3 KM BULK SHEAR VALUES ARE JUST AS HIGH. THIS
SUGGESTS THAT IF SEVERE WX WERE TO DEVELOP...DAMAGING WIND GUSTS
WOULD BE THE BIGGEST THREATS IF ANY DEVELOPING CONVECTION WERE TO
MORPH INTO A WELL-DEFINED SQUALL LINE OR SHORT BOWING SEGMENTS. THIS
AGREES WELL WITH LOCAL SEVERE WX CHECKLIST WHICH SUGGEST A
SIGNIFICANT COOL SEASON WIND EVENT IS POSSIBLE HOWEVER ITS HARD TO
GET BY LATEST MODEL TRENDS OF VERY MODEST DESTABILIZATION.
CONSIDERING THE AMOUNT OF CLOUD COVER THAT WILL LIKELY BEGIN
MOVING OVERHEAD THIS MORNING COUPLED WITH THE FACT THAT RETURN
FLOW MOISTURE WILL BE MEAGER AT BEST (AFTERNOON DEWPOINT TEMPS
ONLY CLIMBING INTO THE MIDDLE TO UPPER 40S)...WE/RE INCLINED TO
BELIEVE THAT SEVERE WX POTENTIAL WILL BE FAIRLY LIMITED. THIS
AGREES WELL WITH THE LATEST SPC DAY 1 OUTLOOK WHICH ONLY
ADVERTISES GENERAL THUNDER MENTION ACROSS OUR REGION ("SEE TEXT" TO
OUR SOUTHWEST). ALTHOUGH WE TOTALLY CANNOT RULE OUT SEVERE WX
LATER TODAY...WE DO NOT THINK THAT THE FCST REGION WILL BE DEALING
WITH A WIDESPREAD SEVERE WX EVENT AT THIS TIME.
NOW TO THE NEXT ISSUE...THE HIGH TEMP FCST FOR TODAY. UPSTREAM OBS
FROM THE UPPER OHIO VLY SHOW TEMPS IN THE LOWER 60S AS CLOSE AS
CLEVELAND EARLY THIS MORNING. CONSIDERING THIS AIR WILL TRAVEL
EAST OVER OUR REGION...WE/RE INCLINED TO BELIEVE TEMPS WILL WARM
INTO THE UPPER 60S TO LOWER 70S AHEAD OF THE FRONT TODAY. ONLY
ITEM OF CONCERN IS THE LATEST SATELLITE TRENDS WHICH SHOW ENHANCED
CLOUD COVER APPROACHING FROM NORTHERN OHIO THIS MORNING. DESPITE
THIS HOWEVER...DEGREE OF THERMAL ADVECTION WILL LIKELY BE ENOUGH
TO OVERCOME LIMITED COOLING ASSOCIATED WITH INCREASING CLOUDS
ALOFT.
BY TONIGHT...COLD FRONT TO EXIT OFF TO THE EAST WITH TIME BETWEEN
00 AND 06Z. RAIN SHOULD GRADUALLY COME TO AN END WITH TIME WITH
STRONG COLD AIR ADVECTION EXPECTED IN ITS WAKE. AS A
RESULT...TEMPS WILL DROP INTO THE LOWER TO MIDDLE 30S ACROSS MUCH
OF THE REGION WITH GUSTY WINDS EXPECTED THROUGH A GOOD PORTION OF
THE OVERNIGHT HRS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
COOLER TEMPS EXPECTED BOTH THU AND FRI AS COOL HIGH PRESSURE
BUILDS IN FOLLOWING FROPA LATER TONIGHT. WITH H85 TEMPS QUICKLY
FALLING TO NEAR ZERO CELSIUS...HIGH TEMPS ON THU ONLY LOOK TO
WARM INTO THE LOWER TO MIDDLE 50S AT BEST. SLIGHTLY WARMER TEMPS
EXPECTED ON FRI AS HIGH PRESSURE ADVANCES TO THE EAST WITH UPPER
50S TO LOWER 60S AGAIN POSSIBLE. WEAK UPPER WAVE WILL PASS ACROSS
THE REGION THU NGT/EARLY FRI BRINGING THE NEXT ROUND OF SHWRS TO
THE AREA.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
300 PM UPDATE...
SHAPING UP TO BE A BEAUTIFUL EXTENDED PERIOD WITH HIGH PRESSURE
CENTERED OVER US TO START THE PERIOD THEN SHIFTING EAST BUT STILL
IN CONTROL THROUGH EARLY NEXT WEEK. THE PATTERN IS RATHER STAGNANT
SO WHILE WE WILL SEE TEMPS WARM INTO THE 60S DURING THIS
TIME...THE TRUE STRONG WAA AND ASSOCIATED VERY WARM AIR WILL
REMAIN WELL TO OUR WEST. SOME UNCERTAINTY DOES CREEP IN FROM
SUNDAY NIGHT AND BEYOND AS BOTH THE EURO AND GFS SHOW AN AXIS OF
MOISTURE JUST TO OUR WEST THROUGH THE OHIO VALLEY. THE GFS HINTS
THAT WE MAY SEE SOME SHOWERS ESPECIALLY OVER THE FAR WESTERN
FINGER LAKES DURING THIS TIME WHILE THE EURO IS MUCH DRIER.
SOMETHING TO WATCH CAREFULLY BUT FOR NOW WILL KEEP MOST OF THE
AREA DRY.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDS TODAY AHD OF A COLD FNT APRCHG THE AREA FROM WEST. FNT WILL
BRING SHWRS AND ISLTD TRW STARTING ARND 21Z AND CONTG THRU ARND
00Z. MVFR CIGS AND VSBYS WITH THE SHWRS...ALONG WITH GUSTY WINDS.
BHD THE FNT...CAA WILL BRING MVFR CIGS ALONG WITH SPOTTY MVFR
VSBYS IN SHWRS. DRIER AIR WELL BHD THE FNT WILL RETURN SOME
LOCATIONS TO VFR BEFORE THE END OF THE TAF PD.
OUTLOOK...
THU THRU SUN...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG
NEAR TERM...CMG
SHORT TERM...CMG
LONG TERM...HEDEN
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
635 AM EDT WED APR 24 2013
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TODAY AS A STRONG COLD
FRONT PASSES ACROSS THE AREA. BEHIND THIS FEATURE...DRY
CONDITIONS ARE EXPECTED ON THURSDAY WITH THE NEXT ROUND OF
SHOWERS POSSIBLE THURSDAY NIGHT AND EARLY FRIDAY AS ANOTHER WEAK
WAVE WILL PASSES OVERHEAD. FAIR AND PLEASANT CONDITIONS ARE THEN
EXPECTED FOR THE WEEKEND AS STRONG HIGH PRESSURE BUILDS INTO THE
AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
630 AM UPDATE...
QUICK UPDATE TO ACCOUNT FOR LATEST RADAR TRENDS TO OUR WEST.
REGIONAL RADARS NOW SHOWING AN INITIAL BAND OF LGT RAIN SHWRS
WORKING INTO WESTERN NY THIS HR...WHICH APPEARS TO BE THE RESULT
OF WEAK ISENTROPIC ASCENT ALONG/NORTH OF DIFFUSE WARM FRONT. THAT
SAID...HAVE UPDATED GRIDS TO BRING IN RAIN A FEW HRS EARLIER
ACROSS THE WESTERN AND NORTHERN ZONES. NO OTHER CHANGES NEEDED AT
THE PRESENT TIME.
PREVIOUS NEAR TERM DISCUSSION...
A CHALLENGING FCST TO SAY THE LEAST TODAY AS A STRONG COLD FRONT
WILL PLOW THROUGH THE REGION DURING THE LATE AFTERNOON AND EARLY
EVENING HRS. THE MAIN DIFFICULTIES ARE TWOFOLD WITH THE FIRST
BEING THE DEGREE OF WARMING PROCEEDING THE FRONT...AND THE SECOND
CONCERNING SEVERE WX POTENTIAL AS THE FRONT BARRELS THROUGH THE
REGION. FIRST THINGS FIRST HOWEVER AND WE SHOULD PROBABLY START
WITH A GENERAL SYNOPTIC OVERVIEW.
EARLY MORNING WATER VAPOR CLEARLY SHOWING A DEEP TROUGH OF LOW
PRESSURE DIGGING ACROSS THE SOUTHERN PLAINS THIS MORNING WITH
BROAD CYCLONIC FLOW PREVAILING OVER THE NATION/S MIDSECTION.
ACROSS OUR REGION...WEAK UPPER RIDGING THAT BROUGHT SUCH NICE
WX TO OUR AREA YESTERDAY NOW DEPARTING TO OUR EAST AS UPPER TROUGH
AND ASSOCIATED DEFORMATION AXIS WITH THE WESTERN ATLANTIC COASTAL
LOW WORK OFF THE NEW ENGLAND COAST. WITH TIME TODAY...COLD FRONT
ASSOCIATED WITH THE CENTRAL US TROUGH WILL ADVANCE EAST OVER OUR
REGION BY THIS AFTERNOON BRINGING WITH IT A PERIOD OF SHWRS AND
STORMS TO MUCH OF OUR AREA.
AS FOR THE SEVERE WX POTENTIAL...MODELS REMAIN ALL OVER THE PLACE
WITH RESPECT TO THE DEGREE OF DESTABILIZATION THAT WILL OCCUR
PRIOR TO FROPA LATER TODAY. THE NAM REMAINS THE MOST UNSTABLE
SOLUTION THIS MORNING WITH AWIPS PLAN VIEW MAPS SHOWING A NARROW
CORRIDOR OF MLCAPE VALUES RANGING FROM 400-500 J/KG IMMEDIATELY
PROCEEDING THE FRONT MAINLY WEST OF THE I-81 CORRIDOR. THIS IS
PERPLEXING TO SOME DEGREE AS CORRESPONDING NAM BUFKIT SOUNDINGS
FOR ELM AND OTHER WESTERN FCST POINT LOCATIONS ADVERTISE MUCH
LOWER VALUES. THE GFS SEEMS TO AGREE WITH THE WEAKER NAM BUFKIT
SOLUTIONS...AS DOES THE LATEST RUC AND LOCALLY RUN WRF MODELS. AS
FOR THE KINEMATICS...WIND FIELDS ALOFT REMAIN IMPRESSIVELY STRONG
WITH 0-6 KM BULK SHEAR VECTORS RANGING FROM 40 TO 50 KTS ACROSS
THE REGION WHILE 0-3 KM BULK SHEAR VALUES ARE JUST AS HIGH. THIS
SUGGESTS THAT IF SEVERE WX WERE TO DEVELOP...DAMAGING WIND GUSTS
WOULD BE THE BIGGEST THREATS IF ANY DEVELOPING CONVECTION WERE TO
MORPH INTO A WELL-DEFINED SQUALL LINE OR SHORT BOWING SEGMENTS. THIS
AGREES WELL WITH LOCAL SEVERE WX CHECKLIST WHICH SUGGEST A
SIGNIFICANT COOL SEASON WIND EVENT IS POSSIBLE HOWEVER ITS HARD TO
GET BY LATEST MODEL TRENDS OF VERY MODEST DESTABILIZATION.
CONSIDERING THE AMOUNT OF CLOUD COVER THAT WILL LIKELY BEGIN
MOVING OVERHEAD THIS MORNING COUPLED WITH THE FACT THAT RETURN
FLOW MOISTURE WILL BE MEAGER AT BEST (AFTERNOON DEWPOINT TEMPS
ONLY CLIMBING INTO THE MIDDLE TO UPPER 40S)...WE/RE INCLINED TO
BELIEVE THAT SEVERE WX POTENTIAL WILL BE FAIRLY LIMITED. THIS
AGREES WELL WITH THE LATEST SPC DAY 1 OUTLOOK WHICH ONLY
ADVERTISES GENERAL THUNDER MENTION ACROSS OUR REGION ("SEE TEXT" TO
OUR SOUTHWEST). ALTHOUGH WE TOTALLY CANNOT RULE OUT SEVERE WX
LATER TODAY...WE DO NOT THINK THAT THE FCST REGION WILL BE DEALING
WITH A WIDESPREAD SEVERE WX EVENT AT THIS TIME.
NOW TO THE NEXT ISSUE...THE HIGH TEMP FCST FOR TODAY. UPSTREAM OBS
FROM THE UPPER OHIO VLY SHOW TEMPS IN THE LOWER 60S AS CLOSE AS
CLEVELAND EARLY THIS MORNING. CONSIDERING THIS AIR WILL TRAVEL
EAST OVER OUR REGION...WE/RE INCLINED TO BELIEVE TEMPS WILL WARM
INTO THE UPPER 60S TO LOWER 70S AHEAD OF THE FRONT TODAY. ONLY
ITEM OF CONCERN IS THE LATEST SATELLITE TRENDS WHICH SHOW ENHANCED
CLOUD COVER APPROACHING FROM NORTHERN OHIO THIS MORNING. DESPITE
THIS HOWEVER...DEGREE OF THERMAL ADVECTION WILL LIKELY BE ENOUGH
TO OVERCOME LIMITED COOLING ASSOCIATED WITH INCREASING CLOUDS
ALOFT.
BY TONIGHT...COLD FRONT TO EXIT OFF TO THE EAST WITH TIME BETWEEN
00 AND 06Z. RAIN SHOULD GRADUALLY COME TO AN END WITH TIME WITH
STRONG COLD AIR ADVECTION EXPECTED IN ITS WAKE. AS A
RESULT...TEMPS WILL DROP INTO THE LOWER TO MIDDLE 30S ACROSS MUCH
OF THE REGION WITH GUSTY WINDS EXPECTED THROUGH A GOOD PORTION OF
THE OVERNIGHT HRS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
COOLER TEMPS EXPECTED BOTH THU AND FRI AS COOL HIGH PRESSURE
BUILDS IN FOLLOWING FROPA LATER TONIGHT. WITH H85 TEMPS QUICKLY
FALLING TO NEAR ZERO CELSIUS...HIGH TEMPS ON THU ONLY LOOK TO
WARM INTO THE LOWER TO MIDDLE 50S AT BEST. SLIGHTLY WARMER TEMPS
EXPECTED ON FRI AS HIGH PRESSURE ADVANCES TO THE EAST WITH UPPER
50S TO LOWER 60S AGAIN POSSIBLE. WEAK UPPER WAVE WILL PASS ACROSS
THE REGION THU NGT/EARLY FRI BRINGING THE NEXT ROUND OF SHWRS TO
THE AREA.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
300 PM UPDATE...
SHAPING UP TO BE A BEAUTIFUL EXTENDED PERIOD WITH HIGH PRESSURE
CENTERED OVER US TO START THE PERIOD THEN SHIFTING EAST BUT STILL
IN CONTROL THROUGH EARLY NEXT WEEK. THE PATTERN IS RATHER STAGNANT
SO WHILE WE WILL SEE TEMPS WARM INTO THE 60S DURING THIS
TIME...THE TRUE STRONG WAA AND ASSOCIATED VERY WARM AIR WILL
REMAIN WELL TO OUR WEST. SOME UNCERTAINTY DOES CREEP IN FROM
SUNDAY NIGHT AND BEYOND AS BOTH THE EURO AND GFS SHOW AN AXIS OF
MOISTURE JUST TO OUR WEST THROUGH THE OHIO VALLEY. THE GFS HINTS
THAT WE MAY SEE SOME SHOWERS ESPECIALLY OVER THE FAR WESTERN
FINGER LAKES DURING THIS TIME WHILE THE EURO IS MUCH DRIER.
SOMETHING TO WATCH CAREFULLY BUT FOR NOW WILL KEEP MOST OF THE
AREA DRY.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
GNRL VFR CONDS WILL CONT TNGT AND MUCH OF WED. ONLY XCPTN IS THE
MARINE LYR CLDS THAT MAY BRING AN OCNL MVFR CIG TO AVP OVRNGT.
OTRW...STRONG FNT MVES INTO THE AREA BEGINNING ARND 21Z WITH A
GOOD CHANCE OF CONV WITH MVFR CIGS AND VSBYS IN BRIEF HEAVY RAIN.
WINDS SHD BE QUITE GUSTY INVOF OF THE FNT...WITH A SWITCH TO THE
WEST AFTER PASSAGE. BHD THE FNT...CAA SC WILL KEEP CIGS IN THE
MVFR RANGE THRU THE END OF THE PD.
OUTLOOK...
WED NGT...MVFR IN SHRA.
THU THRU SUN...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG
NEAR TERM...CMG
SHORT TERM...CMG
LONG TERM...HEDEN
AVIATION...DGM/DJN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
758 AM EDT WED APR 24 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA THIS MORNING. A WEAK TROF
WILL MOVE ACROSS THE REGION ON THURSDAY. HIGH PRESSURE WILL BUILD
INTO THE AREA THURSDAY NIGHT AND MOVE EAST FRIDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE COLD FRONT IS MOVING SLOWER THAN EXPECTED. AT DAYBREAK IT WAS
OVER THE TOLEDO AREA. BY MID MORNING IT SHOULD BE LOCATED NEAR A
CLEVELAND TO MARION LINE AND THEN BY EARLY AFTERNOON IT WILL BE EAST
OF ERIE AND YOUNGSTOWN. THE SHOWERS WILL BECOME NUMEROUS AGAIN
BOTH AHEAD OF AND BEHIND THE FRONT. ANY THUNDER WILL BE ISOLATED
AND MAINLY EAST OF MFD AND SOUTH OF CAK THIS MORNING JUST AHEAD OF
THE FRONT. MADE SOME MINOR CHANGES TO INCLUDE THE SHOWERS A LITTLE
LONGER THIS AFTERNOON OVER NORTHWEST OHIO WITH PLENTY OF OMEGA AND
MOISTURE IT WILL HANG AROUND. THE MODELS INCLUDING THE HRRR AND
THE 4KM WRF-NMM 00Z AGREE WITH THAT.
WITH THE SLOWER MOVEMENT OF THE FRONT HAD TO ADJUST THE
TEMPERATURES. NONE THE LESS THEY WILL BE FALLING. THE TEMPERATURES
OVER NORTHWEST OHIO COULD RECOVER LATE IN THE AFTERNOON.
QPF FOR THIS EVENT WILL BE UNDER AN INCH. NOT EXPECTING ANY
FLOODING PROBLEMS...HOWEVER...RIVER AND CREEKS WILL RISE
SOME...BUT MOST WILL REMAIN BELOW BANKFULL. IN MOST AREAS THE GROUND IS
DRY AND WITH THE TREES BUDDING THIS WILL HELP KEEP THE GROUND FROM
BECOMING TOO SATURATED. THE HPC QPF COULD BE A LITTLE
HIGH...ADJUSTED IT DOWN SOME.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
SOME SHOWERS WILL LINGER IN THE EVENING OVER NE OHIO AND NW PA.
THE CLOUDS WILL DECREASE BUT WITH THE LAKE AND 850 MB TEMPERATURE
DIFFERENCE NEAR 11C LATE TONIGHT SOME LAKE EFFECT CLOUDS MAY OCCUR
IN THE SNOW BELT AREAS...THE MODELS DON`T THINK THIS WILL HAPPEN.
USED A BLEND OF GUIDANCE FOR THE LOWS.
A WEAK TROF WILL MOVE THROUGH ON THURSDAY. KEPT THE POPS UNDER 50
PERCENT. THE QUESTION IS HOW MUCH MOISTURE WILL BE WITH THIS TROF.
THE MODELS ARE NOT IN AGREEMENT...THE ECMWF IS MUCH DRIER THAN THE
NAM AND GFS. NONE THE LESS THE QPF WILL BE LIGHT...GENERALLY UNDER
A TENTH OF AN INCH. TENDED TOWARD A LITTLE MORE MOISTURE BUT KEPT
THE WORDING CHANCE FOR THE TIME BEING.
HIGH PRESSURE WILL BUILD IN THURSDAY NIGHT AND MOVE EAST FRIDAY
NIGHT. SOME CLOUDS WILL OCCUR SATURDAY AS A WEATHER SYSTEM MOVES
THROUGH THE OHIO VALLEY.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
SPLIT FLOW WILL BE IN PLACE ACROSS NORTH AMERICA OVER THE WEEKEND
WITH MOISTURE SPREADING NORTH FROM THE GULF OF MEXICO AHEAD OF
SHORTWAVE ENERGY APPROACHING FROM THE FOUR CORNERS REGION. THE
MOISTURE WILL PUSH NORTH ON SUNDAY AND LINGER THROUGH MONDAY WITH A
LOW CHANCE OF SHOWERS BOTH DAYS. THERE WILL BE SOME MARGINAL
INSTABILITY BUT FORCING IS PRETTY WEAK AND WILL LEAVE THUNDERSTORMS
OUT OF THE FORECAST FOR NOW. OTHERWISE TEMPERATURES WILL BE FAIRLY
MILD WITH THE DIURNAL SPREAD DAMPENED BY THE MOISTURE AND CLOUDS.
HIGHS GENERALLY IN THE LOW 60S AND LOWS NEAR 50.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
A COLD FRONT CONTINUES TO MAKE SLOW PROGRESS ACROSS THE AREA AND
HAS ALREADY CLEARED TOL/FDY AS OF 12Z. SHOWERS WILL CONTINUE INTO
THIS AFTERNOON WITH ISOLATED THUNDERSTORMS POSSIBLE. CONDITIONS AHEAD OF
THE FRONT ARE GENERALLY VFR...DROPPING TO IFR WITH A WIND SHIFT TO
THE NORTHWEST WITH THE FRONTAL PASSAGE. HAVE SLOWED DOWN THE
TIMING OF THE FRONT...NOW EXPECTED TO REACH CLE/MFD AROUND 15Z AND
YNG/CAK/ERI BETWEEN 17-18Z. A RIDGE WILL BUILD INTO THE AREA THIS
EVENING AND MODELS ARE PRETTY AGRESSIVE AT CLEARING SKIES OUT.
THERE IS SOME UNCERTAINTY ABOUT THE CLEARING TREND THOUGH AND WILL
HAVE TO KEEP AN EYE ON UPSTREAM TRENDS TODAY.
.OUTLOOK...NON- VFR POSSIBLE THURSDAY AND AGAIN SUNDAY.
&&
.MARINE...
A COLD FRONT WILL MOVE ACROSS LAKE ERIE THROUGH EARLY AFTERNOON
WITH WINDS SHIFTING TO THE NORTHWEST AT 15 TO 20 KNOTS. WAVES WILL
BUILD TO 2 TO 4 FEET IN THE NEARSHORE WATERS AS THE FLOW BECOMES
ONSHORE AND MAY BRIEFLY APPROACH SMALL CRAFT ADVISORY CRITERIA IN
THE PENNSYLVANIA WATERS FOR A FEW HOURS THIS EVENING. WILL ALLOW
THE DAY SHIFT TO MONITOR WINDS AND ISSUE THE SMALL CRAFT FOR A
BRIEF WINDOW IF NEEDED. A RIDGE WILL BUILD IN BEHIND THE FRONT
OVERNIGHT WITH WINDS DECREASING BELOW 15 KNOTS.
SOUTHERLY WINDS WILL RAMP UP AGAIN ON THURSDAY AHEAD OF ANOTHER COLD
FRONT APPROACHING THE AREA FROM THE WEST. THE FRONT WILL CROSS THE
LAKE THURSDAY AFTERNOON WITH WINDS SHIFTING TO WESTERLY. HIGH
PRESSURE WILL BUILD OVER THE OHIO VALLEY ON FRIDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
702 AM EDT WED APR 24 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA THIS MORNING. A WEAK TROF
WILL MOVE ACROSS THE REGION ON THURSDAY. HIGH PRESSURE WILL BUILD
INTO THE AREA THURSDAY NIGHT AND MOVE EAST FRIDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE COLD FRONT IS MOVING SLOWER THAN EXPECTED. AT DAYBREAK IT WAS
OVER THE TOLEDO AREA. BY MID MORNING IT SHOULD BE LOCATED NEAR A
CLEVELAND TO MARION LINE AND THEN BY EARLY AFTERNOON IT WILL BE EAST
OF ERIE AND YOUNGSTOWN. THE SHOWERS WILL BECOME NUMEROUS AGAIN
BOTH AHEAD OF AND BEHIND THE FRONT. ANY THUNDER WILL BE ISOLATED
AND MAINLY EAST OF MFD AND SOUTH OF CAK THIS MORNING JUST AHEAD OF
THE FRONT. MADE SOME MINOR CHANGES TO INCLUDE THE SHOWERS A LITTLE
LONGER THIS AFTERNOON OVER NORTHWEST OHIO WITH PLENTY OF OMEGA AND
MOISTURE IT WILL HANG AROUND. THE MODELS INCLUDING THE HRRR AND
THE 4KM WRF-NMM 00Z AGREE WITH THAT.
WITH THE SLOWER MOVEMENT OF THE FRONT HAD TO ADJUST THE
TEMPERATURES. NONE THE LESS THEY WILL BE FALLING. THE TEMPERATURES
OVER NORTHWEST OHIO COULD RECOVER LATE IN THE AFTERNOON.
QPF FOR THIS EVENT WILL BE UNDER AN INCH. NOT EXPECTING ANY
FLOODING PROBLEMS...HOWEVER...RIVER AND CREEKS WILL RISE
SOME...BUT MOST WILL REMAIN BELOW BANKFULL. IN MOST AREAS THE GROUND IS
DRY AND WITH THE TREES BUDDING THIS WILL HELP KEEP THE GROUND FROM
BECOMING TOO SATURATED. THE HPC QPF COULD BE A LITTLE
HIGH...ADJUSTED IT DOWN SOME.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
SOME SHOWERS WILL LINGER IN THE EVENING OVER NE OHIO AND NW PA.
THE CLOUDS WILL DECREASE BUT WITH THE LAKE AND 850 MB TEMPERATURE
DIFFERENCE NEAR 11C LATE TONIGHT SOME LAKE EFFECT CLOUDS MAY OCCUR
IN THE SNOW BELT AREAS...THE MODELS DON`T THINK THIS WILL HAPPEN.
USED A BLEND OF GUIDANCE FOR THE LOWS.
A WEAK TROF WILL MOVE THROUGH ON THURSDAY. KEPT THE POPS UNDER 50
PERCENT. THE QUESTION IS HOW MUCH MOISTURE WILL BE WITH THIS TROF.
THE MODELS ARE NOT IN AGREEMENT...THE ECMWF IS MUCH DRIER THAN THE
NAM AND GFS. NONE THE LESS THE QPF WILL BE LIGHT...GENERALLY UNDER
A TENTH OF AN INCH. TENDED TOWARD A LITTLE MORE MOISTURE BUT KEPT
THE WORDING CHANCE FOR THE TIME BEING.
HIGH PRESSURE WILL BUILD IN THURSDAY NIGHT AND MOVE EAST FRIDAY
NIGHT. SOME CLOUDS WILL OCCUR SATURDAY AS A WEATHER SYSTEM MOVES
THROUGH THE OHIO VALLEY.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
SPLIT FLOW WILL BE IN PLACE ACROSS NORTH AMERICA OVER THE WEEKEND
WITH MOISTURE SPREADING NORTH FROM THE GULF OF MEXICO AHEAD OF
SHORTWAVE ENERGY APPROACHING FROM THE FOUR CORNERS REGION. THE
MOISTURE WILL PUSH NORTH ON SUNDAY AND LINGER THROUGH MONDAY WITH A
LOW CHANCE OF SHOWERS BOTH DAYS. THERE WILL BE SOME MARGINAL
INSTABILITY BUT FORCING IS PRETTY WEAK AND WILL LEAVE THUNDERSTORMS
OUT OF THE FORECAST FOR NOW. OTHERWISE TEMPERATURES WILL BE FAIRLY
MILD WITH THE DIURNAL SPREAD DAMPENED BY THE MOISTURE AND CLOUDS.
HIGHS GENERALLY IN THE LOW 60S AND LOWS NEAR 50.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AT 06Z A COLD FRONT EXTENDED FROM KFNT-KFWA. SHOWERS WERE SPREADING
EAST AHEAD OF THE FRONT WITH MOST LOCATIONS STARTING OFF WITH VFR
CEILINGS AND OCCASIONAL MVFR VISIBILITIES IN SOME OF THE HEAVIER
SHOWERS. THE FRONT IS MAKING SLOW PROGRESS BUT WILL REACH TOL AROUND
09Z AND CLE AROUND 12Z. SOUTHERLY WINDS AHEAD OF THE FRONT WILL
BECOME LIGHT...THEN SHIFT TO NORTHWEST AND BECOME BREEZY. CONDITIONS
WILL DETERIORATE BEHIND THE FRONT TO IFR IN MOST AREAS WITH SOME
POCKETS OF LOW IFR...AS REPORTED ON UPSTREAM OBSERVATIONS. SHOWERS
WILL CONTINUE THROUGH AT LEAST 18Z...THEN ENDING FROM WEST TO
EAST DURING THE AFTERNOON. HIGH PRESSURE QUICKLY BUILDS IN FROM
THE SOUTHWEST ON WEDNESDAY EVENING WITH SKIES EXPECTED TO SCATTER
OUT BETWEEN 00-06Z.
.OUTLOOK...NON- VFR POSSIBLE THURSDAY AND AGAIN SUNDAY.
&&
.MARINE...
A COLD FRONT WILL MOVE ACROSS LAKE ERIE THROUGH EARLY AFTERNOON
WITH WINDS SHIFTING TO THE NORTHWEST AT 15 TO 20 KNOTS. WAVES WILL
BUILD TO 2 TO 4 FEET IN THE NEARSHORE WATERS AS THE FLOW BECOMES
ONSHORE AND MAY BRIEFLY APPROACH SMALL CRAFT ADVISORY CRITERIA IN
THE PENNSYLVANIA WATERS FOR A FEW HOURS THIS EVENING. WILL ALLOW
THE DAY SHIFT TO MONITOR WINDS AND ISSUE THE SMALL CRAFT FOR A
BRIEF WINDOW IF NEEDED. A RIDGE WILL BUILD IN BEHIND THE FRONT
OVERNIGHT WITH WINDS DECREASING BELOW 15 KNOTS.
SOUTHERLY WINDS WILL RAMP UP AGAIN ON THURSDAY AHEAD OF ANOTHER COLD
FRONT APPROACHING THE AREA FROM THE WEST. THE FRONT WILL CROSS THE
LAKE THURSDAY AFTERNOON WITH WINDS SHIFTING TO WESTERLY. HIGH
PRESSURE WILL BUILD OVER THE OHIO VALLEY ON FRIDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1102 AM EDT WED APR 24 2013
.SYNOPSIS...
A COLD FRONT OVER THE LOWER GREAT LAKES AND UPPER OHIO VALLEY
THIS MORNING WILL PUSH EAST ACROSS CENTRAL PENNSYLVANIA THIS
AFTERNOON AND EVENING. THE COLD FRONT WILL BE ACCOMPANIED BY A
LINE OF SHOWERS AND SCATTERED THUNDERSTORMS. AN UPPER-LEVEL TROUGH
WILL MOVE THROUGH THE GREAT LAKES ON THURSDAY WITH SCATTERED
RAIN OR EVEN SNOW SHOWERS POSSIBLE OVER THE NORTHWEST MOUNTAINS.
HIGH PRESSURE WILL PROVIDE FAIR WEATHER FRIDAY INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 9 PM THIS EVENING/...
THICK BAND OF MID LEVEL CLOUDS MOVING ACROSS C PA THIS MORNING
KEEPING TEMPS A LITTLE COOLER THEN FORECAST AND ADJUSTED
ACCORDINGLY. VIS SAT SHOWS A BRIEF BREAK IN THE CLOUDS BEFORE NEXT
BAND ASSOCIATED WITH THE FRONT APPROACHES THIS AFTERNOON. SHORT
RANGE MODELS ALL IN GOOD AGREEMENT WITH THE TIMING OF SHOWERS AND
THUNDERSTORMS THIS AFTERNOON. LATEST RAP DCAPE SHOWS WEDGE OF
HIGHER CAPES IN ADVANCE OF PRECIP SHIELD SO EXPECT SOME POTENTIAL
STRONG STORMS AND POSSIBLE BOW ECHO TYPE STORMS ESPECIALLY OVER
SOUTHERN COUNTIES AFT 22Z. COOL SURFACE DP AND CLOUD COVER AHEAD
OF PRECIP WILL LIMIT SURFACE INSTABILITY AND LIKELY PREVENT A MORE
WIDESPREAD EVENT. AS PREVIOUS DISCUSSION NOTES THE INGREDIENTS
SEEM TO BE IN PLACE FOR A LOW TOPPED SQUALL LINE/NCFRB TO IMPACT
MAINLY THE SOUTHERN CWA LATE THIS AFTN/EVE WITH BRIEF HEAVY RAIN
AND POTENTIAL FOR SEVERE TSTM WIND GUSTS. THE SPC DAY 1 OUTLOOK
HIGHLIGHTS PORTIONS OF THE AREA FOR LOW PROBS FOR DMGG WINDS. WILL
CONTINUE EMPHASIZE THE POTENTIAL DMGG WIND THREAT IN THE HWO.
&&
.SHORT TERM /9 PM THIS EVENING THROUGH 6 AM THURSDAY/...
GUSTY WESTERLY FLOW BEHIND THE FRONT WILL USHER COOLER AIR BACK
INTO CENTRAL PA FOR TONIGHT...WITH LOWS NEAR THE FREEZING MARK IN
THE NRN MTNS. ALSO CAN/T RULE OUT POST-FRONTAL RAIN/SNOW SHOWERS
ACRS THE WRN ALLEGHENIES.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
BROAD UPPER TROFFING OVER THE EASTERN U.S. WILL TRANSITION TO
FAST ZONAL FLOW BY THE START OF THE LONG TERM PERIOD...WITH UPPER
RIDGING BUILDING OVER THE EAST COAST BY THE MIDDLE OF NEXT WEEK.
AREAS SE OF THE ALLEGHENY FRONT WILL SEE THE CHILL MODIFIED BY
THE DESCENDING NW TO NRLY FLOW. HIGH TEMPS WILL BE JUST A FEW TO
SVRL DEG F BELOW NORMAL BOTH THURSDAY AND FRIDAY.
HIGH PRESSURE WILL COVER THE ENTIRE THIRD OF THE CONUS THURSDAY
AND FRIDAY BEFORE SLOWLY MOVING OFFSHORE BY SUNDAY. PLENTY OF
SUNSHINE IS EXPECTED FOR THE CENTRAL AND SE VALLEYS...WHILE BKN-
OVC SKIES RESIDE ACROSS THE NW MTNS.
FRIDAY AND MUCH OF SATURDAY CONTINUES TO LOOK DRY. THE SECOND HALF
OF THE WEEKEND IS IN DOUBT HOWEVER GIVEN CONTINUED WIDE SPREAD IN
SOLUTIONS REGARDING THE IMPACT OF INCREASING EASTERLY FLOW OVER
THE COASTAL MID ATLANTIC AND HOW MUCH LLVL MOISTURE MAY ADVECT
TOWARDS THE MASON DIXON LINE AND POINTS NORTHWARD. LATEST ECMWF
KEEPS CENTRAL AND EASTERN AREAS DRY...WITH A RETURN FLOW OF
MOISTURE AND SLIGHTLY ANOMALOUS PW PRODUCING AT LEAST A SMALL CHANCE
OF SHOWERS OVER EASTERN OHIO AND WESTERN PA SUNDAY AFTERNOON WHICH
COULD LINGER ON MONDAY.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
24/12Z...
IFR-MVFR CIGS AND VISBYS HAVE DEVELOPED ACRS THE ERN TERMINALS AND
SHOULD PERSIST THRU 14-15Z.
THE MAIN AVIATION CONCERN WILL BE THE COLD FROPA EXPECTED TO
IMPACT THE AIRSPACE FROM LATER THIS AFTN THRU THE EVE HOURS. A
SW-NE ORIENTED BAND OF SHOWERS WITH EMBEDDED TSTMS SHOULD DEVELOP
ALONG/NEAR THE EWD ADVANCING COLD FRONT OVER WRN PA...AND ORGANIZE
INTO A STRONGLY FORCED LOW-TOPPED CONVECTIVE LINE - POSING AT
LEAST SOME THREAT FOR STG WIND GUSTS - AS IT CROSSES CNTRL AND ERN
SXNS. CONFIDENCE IN TSTM IMPACTS IS INCREASING...WITH THE HI-RES
MDL DATA ALL IN GOOD AGREEMENT. EXPECT MVFR TO LCL IFR VIS IN MOD-
HVY SHRA/ISOLD TSRA WITH LOW END VFR TO MVFR CIGS. GUSTY POST-
FRONTAL/WESTERLY FLOW REGIME TONIGHT WILL LKLY FEATURE MVFR CIGS
ACRS WRN TAFS WITH VFR CONDS PREVAILING E OF THE MTNS.
.OUTLOOK...
THU...SCT -SHRA/MVFR CIGS NW. VFR ELSEWHERE.
FRI-SAT...NO SIG WX.
SUN...VFR. ISOLD PM -SHRA PSBL WEST.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROSS/STEINBUGL
NEAR TERM...ROSS/STEINBUGL
SHORT TERM...ROSS/STEINBUGL
LONG TERM...DEVOIR/GARTNER
AVIATION...ROSS/STEINBUGL
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1043 AM EDT WED APR 24 2013
.SYNOPSIS...
A COLD FRONT WILL SLOWLY CROSS THE WESTERN CAROLINAS AND NORTHEAST
GEORGIA TONIGHT. MILD HIGH PRESSURE WILL THEN BUILD IN BEHIND THE
FRONT FOR THURSDAY AND FRIDAY. A SLOW MOVING AREA OF LOW PRESSURE
WILL DEVELOP OVER THE SOUTHERN PLAINS FRIDAY NIGHT AND DRIFT
NORTHEASTWARD THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 1040 EDT...STRATUS FIELD OVER THE UPSTATE AND SOUTHERN NC
PIEDMONT SHRINKING AND ADVECTING TO THE N. IT SHOULD BE GONE BY
MIDDAY. HOWEVER...CLOUDS IN ADVANCE OF THE COLD FRONT TO THE WEST
OVER ERN TN ENCROACHING QUICKLY FROM THE W. CURRENT SKY GRID
HANDLES THIS WELL. 12Z NAM SILL SUPPORTS BRINGING NUMEROUS
SHOWERS/TSTORMS INTO THE TN BORDER COUNTIES BY MID AFTERNOON.
HOWEVER...IT CONTINUES THE PREVIOUS FORECAST TREND THAT WEAKENS
AND SCATTERS OUT THE CONVECTION AS IT MOVES OUT OF THE MOUNTAINS
LATE THIS AFTERNOON INTO THIS EVENING. HAVE MAINTAINED THE CHANCE
OF THUNDER OVER THE WESTERN HALF OF THE AREA INTO THIS
EVENING...BUT THUNDER CHANCES QUICKLY DIMINISH AFTER 00Z.
PREVIOUS DISCUSSION:
1130 UTC UPDATE...ONLY CHANGES WERE A FEW TWEAKS TO THE AVIATION
GRIDS FOR THE 12Z TAFS. SKY GRIDS LOOK TO BE ROUGHLY IN LINE WITH
CURRENT SAT/OBS.
AS OF 515 AM...THE SKY GRIDS WERE UPDATED TO REFLECT ENCROACHING LOW
STRATUS FROM THE SOUTH. THE 08Z RAP SEEMS TO BE INITIALIZING THE
CLOUDS FAIRLY WELL AND SO IT WAS USED TO REFLECT TRENDS IN THE
CLOUDS THRU MID MORNING. BASICALLY...IT LOOKS LIKE THE CLOUDS WILL
REACH ROUGHLY TO I-85 AROUND OR SHORTLY AFTER DAYBREAK...EXTENDING
NE TOWARD THE TRIAD. FROM THERE IT SHUD DISSIPATE AS INSOLATION
MIXES THE INVERSION/SHALLOW MOISTURE OUT BY MIDDAY.
MEANWHILE...STRATUS DECK (AROUND 5000 FT) CONTINUES TO WORK INTO THE
SW NC MTNS AND NE GA FROM THE WEST. OVERALL...STILL EXPECTING SOME
SUNSHINE BEFORE THICKER CLOUDS FINALLY OVERTAKE THE SKIES BY
MID/LATE AFTN AS A COLD FRONT WORKS INTO THE AREA. NO OTHER CHANGES
WERE MADE.
AS OF 300 AM...A COLD FRONT WAS ANALYZED CROSSING OHIO VALLEY...WITH
CONVECTION INCREASING IN COVERAGE ALONG AND AHEAD OF THE BNDRY.
MODELS ARE IN GOOD AGREEMENT ON UPR LVL FORCING LAGGING BEHIND THE
FRONT TODAY...WITH THE FRONT LOSING ITS PUNCH AS IT ENTERS THE NC
MTNS THIS AFTN. FCST SNDGS ACRS THE PIEDMONT SHOW A SUBSIDENCE
INVERSION THAT IS SLOW TO ERODE THIS AFTN/EVE...RESULTING IN
GENERALLY LESS THAN 500 J/KG OF CAPE. TAKING A BLEND OF THE GFS AND
NAM FOR CAPE...I ONLY GET CHC THUNDER IN THE MTNS WITH NO MENTION
ACRS THE PIEDMONT. OVERALL...A MODEL BLEND OF THE POPS RESULTS IN A
CUT BACK FROM PREV FCST. ALL IN ALL...EXPECTING MAINLY GARDEN
VARIETY SHWRS/TSTMS IN THE MTNS THIS AFTN AND GENERALLY WIDELY SCT
SHWRS ACRS THE ENTIRE AREA THIS EVENING...TAPERING OFF OVERNIGHT
FROM NW TO SE. WITH THE FRONT HAVING AN ANAFRONT STRUCTURE...UPGLIDE
BEHIND THE SFC BNDRY MAY RESULT IN LINGERING SHWRS ALONG AND SOUTH
OF I-85 RIGHT UP TILL DAYBREAK. TEMPS SHUD BE ABLE TO WARM TO ABOVE
NORMAL READINGS EAST OF THE MTNS...AS THICKER CLOUDS AND MOISTURE
DOESN/T ENTER THE AREA TILL AFTER PEAK HEATING. LOWS OVERNIGHT NEAR
NORMAL.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 235 AM EDT WEDNESDAY...THE LATEST NAM AND GFS RUNS CLEAR OUT
CLOUD COVER BY ABOUT MID-MORNING ON THURSDAY. AS I DON/T THINK WE
WILL SEE THAT MUCH PCPN INTO THE PRE-FRONTAL AIRMASS OVER THE
FOOTHILLS AND PIEDMONT...I SUSPECT THAT LOW CLOUDS WON/T BE IN
ABUNDANCE IN THE FIRST PLACE. IT WILL BE A NICE AFTERNOON WITH
CLEAR...BLUE SKIES AND MAX TEMPS A COUPLE CATEGORIES BELOW NORMAL.
FROST STILL APPEARS LIKE A GOOD BET OVER THE NC MTNS AND POSSIBLY
THE WRN FOOTHILLS THURSDAY NIGHT. I/VE INCREASED THE AREAL COVERAGE
OF FROST IN THE WEATHER GRIDS TO ACCOUNT FOR THIS. SOME OF THE
TYPICAL COLD SPOTS AND/OR SHELTERED VALLEYS WILL WILL PROBABLY FALL
TO FREEZING.
FRIDAY WILL ALSO BE A NICE DAY...THOUGH MID AND HIGH LEVEL CLOUD
COVER WILL INCREASE DURING THE AFTERNOON HOURS AHEAD OF A SOUTHERN
STREAM SHORT WAVE. DESPITE THE HIGH CLOUDS...TEMPERATURES SHOULD BE
A FEW DEGREES WARMER THAN THURSDAY/S HIGHS.
FRIDAY NIGHT CLOUDS WILL CONTINUE TO THICKEN AND LOWER AND THERE
WILL BE A CHANCE OF RAIN LATER AT NIGHT...ESPECIALLY OVER THE
MOUNTAINS. THE PCPN WILL BE FORCED AS THE WRN CAROLINAS AND NE GA
WILL BE IN THE RT ENTRANCE REGION OF A 110 KT UPPER JET CENTERED
OVER ERN NC. A SRN STREAM JET MOVING ACROSS THE DEEP SOUTH MAY ALSO
CONTRIBUTE SOME LIFT TO THE SYSTEM. THE SFC COLD FRONT WILL BE WELL
TO OUR SOUTH...DOWN ALONG THE GULF COAST. THEREFORE THE PCPN SHOULD
BE HIGH BASED AND MORE STRATIFORM IN NATURE. ANY STRONG LLVL WARM
ADVECTION STAYS WELL SOUTHWEST OF THE REGION...CLOSER TO THE SFC-H8
FRONT...SO PCPN SHOULD BE LIGHT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM EDT WEDNESDAY...THE LATEST WPC EXTENDED DISCUSSION
FAVORS THE 12 UTC ECMWF FOR THE SAT-TUE PERIOD. LOOKING AT THEIR
EXTENDED RANGE GUIDANCE...THEY HAVE LIKELY POPS ON SATURDAY AND
SOLID CHANCE POPS SUN-TUE.
WHILE THE LATEST GFS IS WEAKER WITH THE FORCING...IT/S STILL IN
PRETTY GOOD AGREEMENT WITH THE 12 UTC RUN OF THE EC IN BRINGING A
SRN STREAM SHORT WAVE SLOWLY ACROSS THE REGION OVER THE WEEKEND.
UPGLIDE WILL INCREASE OVER A LLVL FRONTAL BNDRY...BRINGING PCPN TO
THE REGION. HOWEVER...THERE HAS BEEN A TREND IN THE MODELS TO
DEVELOP THE PCPN FARTHER SOUTH. THIS MAKES A LOT OF SENSE TO ME AS A
BELT OF STRONG MID-TROPOSPHERE FLOW WILL EXIST DOWN TOWARD THE GOM.
THE SFC BNDRY WILL LIKELY HAVE A DIFFICULT TIME LIFTING NORTH OF
THIS BAROCLINIC ZONE ALOFT...AND I CAN SEE QUITE A BIT OF
CONVECTION AND PCPN DEVELOPING DOWN TOWARD THE GULF...ESPECIALLY AS
WE GET INTO SUNDAY.
MONDAY AND TUESDAY THE SRN STREAM IS EVEN STRONGER AND FURTHER SOUTH
AS A MID-LATITUDE H5 RIDGE BEGINS TO DEVELOP OVER THE TN RIVER
VALLEY. THIS BLOCKING RIDGE PROVIDES A BROAD SEPARATION BETWEEN THE
NRN STREAM SHOOTING ACROSS THE NRN PLAINS AND THE SRN STREAM DOWN
ACROSS THE NRN GOM. WHILE WE WOULD CERTAINLY SEE SOME PCPN FROM THIS
PATTERN...I SUSPECT THAT MOST OF THE PCPN INTO MON AND TUE WILL
REMAIN SOUTH OF THE FORECAST AREA. THAT IS IF THIS PARTICULAR
PATTERN DOES EVOLVE. THIS IS NOT A HIGH CONFIDENCE FORECAST...AND
I/M NOT GOING TO DO ANYTHING DRAMATIC TO THE POPS ON THIS SHIFT.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...IFR (EVEN A PERIOD OF LIFR) STRATUS AND FOG TO START THE
12Z TAF. THE CLOUDS SHUD START TO LIFT AND SCATTER OUT MID-LATE
MORNING...SUCH THAT IT IS EXPECTED TO BE VFR BY NOON (16Z). AT THAT
POINT...SWLY WINDS WILL INCREASE AND BECOME GUSTY THRU THE AFTN
HOURS. STILL EXPECT AN AREA OF SCATTERED SHRA TO AFFECT THE REGION
THIS EVENING AS A COLD FRONT PUSHES IN FROM THE NW. WILL HAVE A
PROB30 FOR SHRA STARTING AT 00Z. INSTBY AND FORCING WILL BE LACKING
FOR MUCH OF A TS CHC...SO WILL NOT HAVE MENTION WITH THESE TAFS.
HOWEVER...IF GUIDANCE IS NOT HANDLING THE ENVIRONMENT WELL...THUNDER
MAY BE ADDED IN WITH AN AMD OR THE 18Z TAF. SOME CLOUDS WILL
PROBABLY LINGER BEHIND THE FRONT OVERNIGHT...WITH A SHIFT IN WINDS
TO N/NE. GUIDANCE IS STILL MIXED ON WHETHER ANY RESTRICTIONS LOWER
THAN VFR WILL OCCUR...SO STILL LEAVING IT VFR FOR TONIGHT.
ELSEWHERE...IFR STRATUS HAS REACHED KGSP/KGMU AND WILL REACH KAND BY
12Z. THESE CLOUDS SHUD LIFT AND SCATTER OUT IN THE 14-16Z TIME FRAME
TO VFR BY NOON. VFR CONDITIONS EXPECTED THIS AFTN WITH GUSTY S/SWLY
WINDS AHEAD OF AN APPROACHING COLD FRONT. MOISTURE WITH THE FRONT IS
PROGGED TO ENTER THE KAVL AREA BY MID AFTN AND ACRS THE REST OF THE
TAF SITES LATE AFTN/EVENING. CONVECTION WITH THE FRONT LOOKS TO BE
RATHER STARVED FOR FORCING/INSTBY...SO AM GOING WITH JUST PROB30S FOR
SHRA AT ALL SITES. HIGHEST CHCS WILL BE AT KAVL...AS MOISTURE ENTERS
THE MTNS FROM THE WEST...SO PREVAILING SHRA THERE WITH POTENTIAL
RESTRICTIONS. LLVL MOISTURE/-RA MAY LINGER BEHIND THE FRONT LATE
THIS EVENING...WHICH MAY RESULT IN SOME RESTRICTIONS. MODELS ARE
STILL MIXED ON HOW MUCH CIG/VSBY RESTRICTIONS WILL EXIST...SO
DECIDED TO KEEP IT VFR FOR NOW.
OUTLOOK...IMPROVING CONDITIONS ARE EXPECTED BY MIDDAY THURSDAY AND
VFR CONDITIONS EXPECTED THROUGH FRIDAY. THE NEXT SYSTEM WILL BRING
MOISTURE BACK INTO THE AREA FRIDAY NIGHT THRU MOST OF THE WEEKEND.
CONFIDENCE TABLE...
14-20Z 20-02Z 02-08Z 08-14Z
KCLT HIGH 88% HIGH 100% HIGH 100% HIGH 80%
KGSP HIGH 94% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 90% HIGH 89% MED 79%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 94% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 94% HIGH 92% HIGH 82% MED 72%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...MCAVOY
NEAR TERM...ARK/LG
SHORT TERM...MCAVOY
LONG TERM...MCAVOY
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
743 AM EDT WED APR 24 2013
.SYNOPSIS...
A COLD FRONT WILL SLOWLY CROSS THE WESTERN CAROLINAS AND NORTHEAST
GEORGIA TONIGHT. MILD HIGH PRESSURE WILL THEN BUILD IN BEHIND THE
FRONT FOR THURSDAY AND FRIDAY. A SLOW MOVING AREA OF LOW PRESSURE
WILL DEVELOP OVER THE SOUTHERN PLAINS FRIDAY NIGHT AND DRIFT
NORTHEASTWARD THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
1130 UTC UPDATE...ONLY CHANGES WERE A FEW TWEAKS TO THE AVIATION
GRIDS FOR THE 12Z TAFS. SKY GRIDS LOOK TO BE ROUGHLY IN LINE WITH
CURRENT SAT/OBS.
AS OF 515 AM...THE SKY GRIDS WERE UPDATED TO REFLECT ENCROACHING LOW
STRATUS FROM THE SOUTH. THE 08Z RAP SEEMS TO BE INITIALIZING THE
CLOUDS FAIRLY WELL AND SO IT WAS USED TO REFLECT TRENDS IN THE
CLOUDS THRU MID MORNING. BASICALLY...IT LOOKS LIKE THE CLOUDS WILL
REACH ROUGHLY TO I-85 AROUND OR SHORTLY AFTER DAYBREAK...EXTENDING
NE TOWARD THE TRIAD. FROM THERE IT SHUD DISSIPATE AS INSOLATION
MIXES THE INVERSION/SHALLOW MOISTURE OUT BY MIDDAY.
MEANWHILE...STRATUS DECK (AROUND 5000 FT) CONTINUES TO WORK INTO THE
SW NC MTNS AND NE GA FROM THE WEST. OVERALL...STILL EXPECTING SOME
SUNSHINE BEFORE THICKER CLOUDS FINALLY OVERTAKE THE SKIES BY
MID/LATE AFTN AS A COLD FRONT WORKS INTO THE AREA. NO OTHER CHANGES
WERE MADE.
AS OF 300 AM...A COLD FRONT WAS ANALYZED CROSSING OHIO VALLEY...WITH
CONVECTION INCREASING IN COVERAGE ALONG AND AHEAD OF THE BNDRY.
MODELS ARE IN GOOD AGREEMENT ON UPR LVL FORCING LAGGING BEHIND THE
FRONT TODAY...WITH THE FRONT LOSING ITS PUNCH AS IT ENTERS THE NC
MTNS THIS AFTN. FCST SNDGS ACRS THE PIEDMONT SHOW A SUBSIDENCE
INVERSION THAT IS SLOW TO ERODE THIS AFTN/EVE...RESULTING IN
GENERALLY LESS THAN 500 J/KG OF CAPE. TAKING A BLEND OF THE GFS AND
NAM FOR CAPE...I ONLY GET CHC THUNDER IN THE MTNS WITH NO MENTION
ACRS THE PIEDMONT. OVERALL...A MODEL BLEND OF THE POPS RESULTS IN A
CUT BACK FROM PREV FCST. ALL IN ALL...EXPECTING MAINLY GARDEN
VARIETY SHWRS/TSTMS IN THE MTNS THIS AFTN AND GENERALLY WIDELY SCT
SHWRS ACRS THE ENTIRE AREA THIS EVENING...TAPERING OFF OVERNIGHT
FROM NW TO SE. WITH THE FRONT HAVING AN ANAFRONT STRUCTURE...UPGLIDE
BEHIND THE SFC BNDRY MAY RESULT IN LINGERING SHWRS ALONG AND SOUTH
OF I-85 RIGHT UP TILL DAYBREAK. TEMPS SHUD BE ABLE TO WARM TO ABOVE
NORMAL READINGS EAST OF THE MTNS...AS THICKER CLOUDS AND MOISTURE
DOESN/T ENTER THE AREA TILL AFTER PEAK HEATING. LOWS OVERNIGHT NEAR
NORMAL.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 235 AM EDT WEDNESDAY...THE LATEST NAM AND GFS RUNS CLEAR OUT
CLOUD COVER BY ABOUT MID-MORNING ON THURSDAY. AS I DON/T THINK WE
WILL SEE THAT MUCH PCPN INTO THE PRE-FRONTAL AIRMASS OVER THE
FOOTHILLS AND PIEDMONT...I SUSPECT THAT LOW CLOUDS WON/T BE IN
ABUNDANCE IN THE FIRST PLACE. IT WILL BE A NICE AFTERNOON WITH
CLEAR...BLUE SKIES AND MAX TEMPS A COUPLE CATEGORIES BELOW NORMAL.
FROST STILL APPEARS LIKE A GOOD BET OVER THE NC MTNS AND POSSIBLY
THE WRN FOOTHILLS THURSDAY NIGHT. I/VE INCREASED THE AREAL COVERAGE
OF FROST IN THE WEATHER GRIDS TO ACCOUNT FOR THIS. SOME OF THE
TYPICAL COLD SPOTS AND/OR SHELTERED VALLEYS WILL WILL PROBABLY FALL
TO FREEZING.
FRIDAY WILL ALSO BE A NICE DAY...THOUGH MID AND HIGH LEVEL CLOUD
COVER WILL INCREASE DURING THE AFTERNOON HOURS AHEAD OF A SOUTHERN
STREAM SHORT WAVE. DESPITE THE HIGH CLOUDS...TEMPERATURES SHOULD BE
A FEW DEGREES WARMER THAN THURSDAY/S HIGHS.
FRIDAY NIGHT CLOUDS WILL CONTINUE TO THICKEN AND LOWER AND THERE
WILL BE A CHANCE OF RAIN LATER AT NIGHT...ESPECIALLY OVER THE
MOUNTAINS. THE PCPN WILL BE FORCED AS THE WRN CAROLINAS AND NE GA
WILL BE IN THE RT ENTRANCE REGION OF A 110 KT UPPER JET CENTERED
OVER ERN NC. A SRN STREAM JET MOVING ACROSS THE DEEP SOUTH MAY ALSO
CONTRIBUTE SOME LIFT TO THE SYSTEM. THE SFC COLD FRONT WILL BE WELL
TO OUR SOUTH...DOWN ALONG THE GULF COAST. THEREFORE THE PCPN SHOULD
BE HIGH BASED AND MORE STRATIFORM IN NATURE. ANY STRONG LLVL WARM
ADVECTION STAYS WELL SOUTHWEST OF THE REGION...CLOSER TO THE SFC-H8
FRONT...SO PCPN SHOULD BE LIGHT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM EDT WEDNESDAY...THE LATEST WPC EXTENDED DISCUSSION
FAVORS THE 12 UTC ECMWF FOR THE SAT-TUE PERIOD. LOOKING AT THEIR
EXTENDED RANGE GUIDANCE...THEY HAVE LIKELY POPS ON SATURDAY AND
SOLID CHANCE POPS SUN-TUE.
WHILE THE LATEST GFS IS WEAKER WITH THE FORCING...IT/S STILL IN
PRETTY GOOD AGREEMENT WITH THE 12 UTC RUN OF THE EC IN BRINGING A
SRN STREAM SHORT WAVE SLOWLY ACROSS THE REGION OVER THE WEEKEND.
UPGLIDE WILL INCREASE OVER A LLVL FRONTAL BNDRY...BRINGING PCPN TO
THE REGION. HOWEVER...THERE HAS BEEN A TREND IN THE MODELS TO
DEVELOP THE PCPN FARTHER SOUTH. THIS MAKES A LOT OF SENSE TO ME AS A
BELT OF STRONG MID-TROPOSPHERE FLOW WILL EXIST DOWN TOWARD THE GOM.
THE SFC BNDRY WILL LIKELY HAVE A DIFFICULT TIME LIFTING NORTH OF
THIS BAROCLINIC ZONE ALOFT...AND I CAN SEE QUITE A BIT OF
CONVECTION AND PCPN DEVELOPING DOWN TOWARD THE GULF...ESPECIALLY AS
WE GET INTO SUNDAY.
MONDAY AND TUESDAY THE SRN STREAM IS EVEN STRONGER AND FURTHER SOUTH
AS A MID-LATITUDE H5 RIDGE BEGINS TO DEVELOP OVER THE TN RIVER
VALLEY. THIS BLOCKING RIDGE PROVIDES A BROAD SEPARATION BETWEEN THE
NRN STREAM SHOOTING ACROSS THE NRN PLAINS AND THE SRN STREAM DOWN
ACROSS THE NRN GOM. WHILE WE WOULD CERTAINLY SEE SOME PCPN FROM THIS
PATTERN...I SUSPECT THAT MOST OF THE PCPN INTO MON AND TUE WILL
REMAIN SOUTH OF THE FORECAST AREA. THAT IS IF THIS PARTICULAR
PATTERN DOES EVOLVE. THIS IS NOT A HIGH CONFIDENCE FORECAST...AND
I/M NOT GOING TO DO ANYTHING DRAMATIC TO THE POPS ON THIS SHIFT.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...IFR (AND EVEN A PERIOD OF LIFR) STRATUS AND FOG TO
START THE 12Z TAF. THE CLOUDS SHUD START TO LIFT AND SCATTER OUT
MID-LATE MORNING...SUCH THAT IT IS EXPECTED TO BE VFR BY NOON
(16Z). AT THAT POINT...SWLY WINDS WILL INCREASE AND BECOME GUSTY
THRU THE AFTN HOURS. STILL EXPECT AN AREA OF SCATTERED SHRA TO
AFFECT THE REGION THIS EVENING AS A COLD FRONT PUSHES IN FROM THE
NW. WILL HAVE A PROB30 FOR SHRA STARTING AT 00Z. INSTBY AND
FORCING WILL BE LACKING FOR MUCH OF A TS CHC...SO WILL NOT HAVE
MENTION WITH THESE TAFS. HOWEVER...IF GUIDANCE IS NOT HANDLING THE
ENVIRONMENT WELL...THUNDER MAY BE ADDED IN WITH AN AMD OR THE 18Z
TAF. SOME CLOUDS WILL PROBABLY LINGER BEHIND THE FRONT
OVERNIGHT...WITH A SHIFT IN WINDS TO N/NE. GUIDANCE IS STILL MIXED
ON WHETHER ANY RESTRICTIONS LOWER THAN VFR WILL OCCUR...SO STILL
LEAVING IT VFR FOR TONIGHT.
ELSEWHERE...IFR STRATUS HAS REACHED KGSP/KGMU AND WILL REACH KAND BY
12Z. THESE CLOUDS SHUD LIFT AND SCATTER OUT IN THE 14-16Z TIME FRAME
TO VFR BY NOON. VFR CONDITIONS EXPECTED THIS AFTN WITH GUSTY S/SWLY
WINDS AHEAD OF AN APPROACHING COLD FRONT. MOISTURE WITH THE FRONT IS
PROGGED TO ENTER THE KAVL AREA BY MID AFTN AND ACRS THE REST OF THE
TAF SITES LATE AFTN/EVENING. CONVECTION WITH THE FRONT LOOKS TO BE
RATHER STARVED FOR FORCING/INSTBY...SO AM GOING WITH JUST PROB30S FOR
SHRA AT ALL SITES. HIGHEST CHCS WILL BE AT KAVL...AS MOISTURE ENTERS
THE MTNS FROM THE WEST...SO PREVAILING SHRA THERE WITH POTENTIAL
RESTRICTIONS. LLVL MOISTURE/-RA MAY LINGER BEHIND THE FRONT LATE
THIS EVENING...WHICH MAY RESULT IN SOME RESTRICTIONS. MODELS ARE
STILL MIXED ON HOW MUCH CIG/VSBY RESTRICTIONS WILL EXIST...SO
DECIDED TO KEEP IT VFR FOR NOW.
OUTLOOK...IMPROVING CONDITIONS ARE EXPECTED BY MIDDAY THURSDAY AND
VFR CONDITIONS EXPECTED THROUGH FRIDAY. THE NEXT SYSTEM WILL BRING
MOISTURE BACK INTO THE AREA FRIDAY NIGHT THRU MOST OF THE WEEKEND.
CONFIDENCE TABLE...
11-17Z 17-23Z 23-05Z 05-11Z
KCLT MED 69% HIGH 100% HIGH 100% HIGH 86%
KGSP MED 74% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 87% HIGH 85%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 82% HIGH 100% HIGH 100% HIGH 100%
KAND MED 74% HIGH 100% HIGH 92% MED 66%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...MCAVOY
NEAR TERM...ARK
SHORT TERM...MCAVOY
LONG TERM...MCAVOY
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1023 AM EDT WED APR 24 2013
.SYNOPSIS...
LOW PRESSURE WAS OVER THE GREAT LAKES WITH A COLD FRONT EXTENDING
INTO SOUTHERN TEXAS. THIS FRONT WILL CROSS THE REGION TODAY WITH
HIGH PRESSURE FOLLOWING FOR THURSDAY AND FRIDAY. LOW PRESSURE
WILL MOVE FROM THE SOUTHERN PLAINS ACROSS THE TENNESSEE VALLEY AND
CAROLINAS ON SATURDAY AND SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 AM EDT WEDNESDAY...
PATCHY EARLY MORNING FOG HAS QUICKLY LIFTED AS MODEST SURFACE
WINDS RESULTED IN SUFFICIENT MIXING. CLEAR SKIES THIS MORNING AND
EARLY AFTERNOON WILL ALLOW TEMPERATURES TO WARM UP QUICKLY BEFORE
CLOUDS ROLL INTO THE AREA AS THE FRONTAL PASSAGE APPROACHES.
CLOUD COVER BEGINS TO INCREASE SUBTLY UNTIL NOON...THEN SHIFT TO
MOSTLY OVERCAST BY THE MID AFTERNOON. THE FRONT WILL MOVE THROUGH
THE CWA BETWEEN 6PM AND MIDNIGHT. GFS AND WRF AGREE ON THE TIMING
OF THE FRONT.
PRECIPITATION ASSOCIATED WITH THE FRONT VARY ACROSS THE CWA... RANGING
FROM A QUARTER OF AN INCH TO THE WEST AND GENERALLY LIGHTER QPF
IN THE EAST AROUND OR LESS THAN A TENTH OF AN INCH. THE SPC HAS
THE CWA UNDER A SEE TEXT... STRONG CONVECTION IS POSSIBLE WITH
THIS SYSTEM... WITH DAMAGING WIND BEING THE MAIN THREAT. CAPE
WILL BE FAIRLY LIMITED WITH VALUES BELOW 500 J/KG AS DAYTIME
HEATING WILL BE CUT SHORT BY THE IMPEDING CLOUD COVER... HOWEVER
SOME STRONGER POCKETS OF ENERGY IN THE WESTERN MOST COUNTIES COULD
SPRING UP SOME THUNDERSTORMS.
THE FRONT WILL START TO BREAK DOWN AS IT CROSSES THE MOUNTAINS
LEADING TO MORE LOCALIZED PRECIPITATION AFTER IT PASSES. COLD AIR
WILL INFILTRATE IN THE WAKE AND KNOCK TEMPERATURES UNSEASONABLY
COOL AS HIGH PRESSURE BEGINS TO MOVE IN FROM THE TENNESSEE VALLEY.
MID-MORNING TEMPERATURES WERE ADJUSTED WARMER BY 5-7 DEGREES IN
PREDOMINATELY WESTERN LOCATIONS. CLOUD COVER WAS DECREASED IN THE
EARLY MORNING/AFTERNOON AND RAPIDLY INCREASES AHEAD OF THE FRONT.
MORNING GRID UPDATES ARE COMPLETED.
AS OF 430 AM EDT WEDNESDAY...
STARTING OUT WITH LITTLE CLOUD COVER THIS MORNING. ONCE MIXING
BEGINS WINDS WILL GUST OUT OF THE SOUTHWEST AND TEMPERATURES WILL
WARM UP QUICKLY. BY THIS AFTERNOON CLOUD COVER MOVES IN SLOWING
DOWN HEATING FOR THE REST OF THE DAY. SHORT RANGE
MODELS...INCLUDING THE RUC AND WRF...HAVE SLOWED DOWN THE TIME OF
THE FRONTAL PASSAGE BY A COUPLE OF HOURS. FORECAST HAS THE FRONT
MOVING THROUGH THE COUNTY WARNING AREA BETWEEN 6PM AND MIDNIGHT.
SHOWERS AND THUNDERSTORMS MAY COME THROUGH IN TWO BANDS. ONE ALONG
THE FRONT...SIMILAR TO WHAT WAS DEVELOPING AROUND 5AM FROM
KENTUCKY TO LOUISIANA...AND THE SECOND...BEHIND THE FRONT.
CONVECTIVE AVAILABLE POTENTIAL ENERGY HAS THE POTENTIAL TO REACH
AROUND 1500 J/KG THIS AFTERNOON BUT MODELS DROP OFF INSTABILITY
QUICKLY AFTER SUNSET.
QUESTIONABLE IF ANY OF THE PRECIPITATION BEHIND THE FRONT WILL
HOLD TOGETHER EAST OF THE BLUE RIDGE. ONCE THE WIND SHIFT TO THE
NORTHWEST...TENDENCY IS FOR DOWNSLOPING COMPONENT TO ERODE
PRECIPITATION. HAVE KEPT PROBABILITY OF PRECIPITATION HIGHEST IN
THE FAR WESTERN COUNTY WARNING AREA AND MUCH LOWER IN THE EAST.
GOOD PRESSURE RISES AND COLD AIR ADVECTION BEHIND THE FRONT
TONIGHT WILL RESULT IN GUSTY NORTHWEST WINDS. THE COOLER AIR MASS
COMING IN WILL HOLD LOW TEMPERATURES BELOW NORMAL.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 327 AM EDT WEDNESDAY...
HIGH PRESSURE STRENGTHENS AND STRETCHES INTO THE MIDDLE ATLANTIC
THURSDAY AND THURSDAY NIGHT. ONE FINAL SHRTWV WITH SCANT MOISTURE
CUTTING THROUGH WEST VA WILL THROW SOME CLOUDS BRIEFLY INTO SE WEST
VA LATE THURSDAY AFTERNOON BEFORE DEPARTING THURSDAY NIGHT.
FRIDAY MORNING LOOKS LIKE A CHILLY ONE WITH SOME MINS NEAR
FREEZING AT THE COLDEST SPOTS AND POTENTIALLY NEAR THE MIDDLE 30S
ACROSS THE VIRGINIA PIEDMONT WHICH MAY LEAD TO SOME PATCHY FROST.
AS THE HIGH DEPARTS LATER FRIDAY SOME HIGH CLOUDS ARRIVE BEFORE
MOISTURE INCREASES AND WINDS BEGIN TO TAKE ON AN EASTERLY
COMPONENT INTO THE WEEKEND. PINPOINTING POPS FOR THIS WEEKEND
REALLY TOUGH RIGHT NOW WITH MODELS NOT SHOWING A LOT OF MEASURABLE
PRECIP SAVE THE NC/VA BORDER. BUT...WOULD THINK SE TO ESE FLOW AND
ABUNDANT MOISTURE WOULD BE ENOUGH FOR SOME LIGHT RAIN SATURDAY OR
SATURDAY NIGHT...FURTHER NORTH THAN MOST MODELS DEPICT. THE 0Z
ECMWF CONTINUES TO BE THE WETTEST SOLUTION BUT EVEN IT HAS NOW
SHIFTED THE PRECIP FURTHER SOUTH. NONETHELESS...GUIDANCE FOR MAX T
SATURDAY SEEMED SEVERAL DEGREES TOO WARM CONSIDERING ALL OF THE
ABOVE...SO WENT BELOW THE MEX MOS NUMBERS...SUBSTANTIALLY SO IN
THE TYPICAL WEDGE AREAS.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 355 PM EDT THURSDAY...
CONSIDERABLE DIFFERENCES REMAIN AMONG THE GFS AND ECMWF DURING THE
EXTENDED PERIODS...BUT ANY WAY YOU LOOK AT IT...IT IS GOING TO BE
WET AND UNSEASONABLY COOL. A VIGOROUS SOUTHERN STREAM DISTURBANCE
IS STILL SLATED TO MOVE INTO THE REGION FROM THE WEST. IT IS THE
SUBSEQUENT MOVEMENT/DEVELOPMENT OF THIS SYSTEM THROUGH THE WEEKEND
INTO EARLY NEXT WEEK THAT BECOMES THE QUESTION. THE GFS HAS IN
GENERAL SHOWN MORE CONSISTENCY WITH THE EVOLUTION OF THIS SYSTEM
THAN THE ECMWF. EACH RUN OF THE ECMWF DEVELOPS A CUTOFF IN A
DIFFERENT LOCATION...WHICH IS RESULTING IN LOWERING CONFIDENCE IN
ANY ONE SOLUTION FROM THAT MODEL.
HOWEVER...BOTH THE GFS AND ECMWF GIVE SOME HINT OF AT LEAST WEAK
CUTOFF LOW PRESSURE DEVELOPING ACROSS THE SOUTHEAST STATES IN A
WEAKNESS AREA. THEREFORE...HAVE KEPT LIKELY POPS SAT-SUN...THEN
TAPER TO MOSTLY CHANCE POPS DURING THE LATER PERIODS. THE LATEST
ECMWF HAS DEFINITELY TRENDED TOWARD A DRIER/WEAKER SOLUTION.
INSTABILITY IS NIL THROUGH THE PERIOD AND WITH BOTH MODELS THERE
IS A STRONG SIGNAL FOR A WEDGE REINFORCED...HENCE IN SITU AS WELL.
HAVE FAVORED THE MUCH COOLER ECMWF GRIDS THROUGHOUT THE EXTENDED
PERIODS.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
AS OF 145 AM EDT WEDNESDAY...
ONCE MIXING BEGINS THIS MORNING THE WIND WILL INCREASE FROM THE
SOUTHWEST AHEAD OF THE APPROACHING COLD FRONT. BUFKIT INDICATED
JET WOULD BE IN THE 25 TO 35 KNOT RANGE. CLOUDS WILL INCREASE
THROUGHOUT THE DAY...ALTHOUGH CEILINGS WILL REMAIN VFR.
LOW PRESSURE MOVING ACROSS THE GREAT LAKES WILL BRING A COLD
FRONT THROUGH THE REGION THIS EVENING. EXPECT FRONTAL PASSAGE AND
WIND SHIFT TO THE NORTHWEST AROUND 23Z/7PM AT BLF AND LWB AND
BETWEEN 00Z/8PM AND 03Z/11PM AT BCB/ROA/DAN/LYH. BRIEF WIND GUSTS
TO 35 KNOTS ARE POSSIBLE WITH THE STRONGER SHOWERS AND
THUNDERSTORMS ALONG THE FRONT. THE SHOWERS MAY NEVER REACH DAN AND LYH
WITH NORTHWEST DOWNSLOPE WINDS AND THE PRECIPITATION MAINLY BEHIND
THE BOUNDARY.
WINDS WILL STILL GUST 20 TO 25 KNOTS FOR A FEW HOURS BEHIND THE
FRONT DUE TO PRESSURE RISES AND COLD AIR ADVECTION. CEILINGS MAY
DROP TO MVFR AT BLF AND LWB BEHIND THE FRONT.CONFIDENCE IS
MODERATE THAT CEILINGS WILL STILL BE MVFR BY 12Z THURSDAY.
HIGH PRESSURE WILL BUILD IN QUICKLY IN THE WAKE OF THE COLD FRONT
FOR THURSDAY AND FRIDAY. ANY MVFR CEILINGS WILL BE WEST OF THE
BLUE RIDGE...AND WILL IMPROVE TO VFR THURSDAY MORNING.
THIS WEEKEND WILL BE UNSETTLED WITH PERIODS OF SHOWERS BEGINNING
SATURDAY AFTERNOON. EXPECT PERIODS OF IFR/MVFR CONDITIONS SATURDAY
AFTERNOON THROUGH THE REST OF THE WEEKEND.
&&
.FIRE WEATHER...
AS OF 515 AM EDT WEDNESDAY...
BREEZY SOUTHWEST WINDS AHEAD OF AN APPROACHING COLD FRONT
TODAY. SOUTHWEST WINDS OF 10 TO 15 MPH WITH GUSTS OF 20 TO 30 MPH
ARE LIKELY BY THIS AFTERNOON. THE WIND WILL ABRUPTLY SHIFT TO THE
NORTHWEST WITH THE PASSAGE OF THE FRONT THIS EVENING. THE FRONT
IS EXPECTED TO CROSS THE MOUNTAINS BETWEEN 6-9PM...THEN MOVE EAST
OF THE BLUE RIDGE AND ACROSS THE PIEDMONT BEFORE MIDNIGHT.
THE CHANCE OF RAIN MOVES BACK INTO THE FORECAST AREA AGAIN ON
SATURDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/KK/SW
SHORT TERM...KM
LONG TERM...RAB
AVIATION...AMS
FIRE WEATHER...AMS/PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
742 AM EDT WED APR 24 2013
.SYNOPSIS...
LOW PRESSURE WAS OVER THE GREAT LAKES WITH A COLD FRONT EXTENDING
INTO SOUTHERN TEXAS. THIS FRONT WILL CROSS THE REGION TODAY WITH
HIGH PRESSURE FOLLOWING FOR THURSDAY AND FRIDAY. LOW PRESSURE
WILL MOVE FROM THE SOUTHERN PLAINS ACROSS THE TENNESSEE VALLEY AND
CAROLINAS ON SATURDAY AND SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 430 AM EDT WEDNESDAY...
STARTING OUT WITH LITTLE CLOUD COVER THIS MORNING. ONCE MIXING
BEGINS WINDS WILL GUST OUT OF THE SOUTHWEST AND TEMPERATURES WILL
WARM UP QUICKLY. BY THIS AFTERNOON CLOUD COVER MOVES IN SLOWING
DOWN HEATING FOR THE REST OF THE DAY. SHORT RANGE
MODELS...INCLUDING THE RUC AND WRF...HAVE SLOWED DOWN THE TIME OF
THE FRONTAL PASSAGE BY A COUPLE OF HOURS. FORECAST HAS THE FRONT
MOVING THROUGH THE COUNTY WARNING AREA BETWEEN 6PM AND MIDNIGHT.
SHOWERS AND THUNDERSTORMS MAY COME THROUGH IN TWO BANDS. ONE ALONG
THE FRONT...SIMILAR TO WHAT WAS DEVELOPING AROUND 5AM FROM
KENTUCKY TO LOUISIANA...AND THE SECOND...BEHIND THE FRONT.
CONVECTIVE AVAILABLE POTENTIAL ENERGY HAS THE POTENTIAL TO REACH
AROUND 1500 J/KG THIS AFTERNOON BUT MODELS DROP OFF INSTABILITY
QUICKLY AFTER SUNSET.
QUESTIONABLE IF ANY OF THE PRECIPITATION BEHIND THE FRONT WILL
HOLD TOGETHER EAST OF THE BLUE RIDGE. ONCE THE WIND SHIFT TO THE
NORTHWEST...TENDENCY IS FOR DOWNSLOPING COMPONENT TO ERODE
PRECIPITATION. HAVE KEPT PROBABILITY OF PRECIPITATION HIGHEST IN
THE FAR WESTERN COUNTY WARNING AREA AND MUCH LOWER IN THE EAST.
GOOD PRESSURE RISES AND COLD AIR ADVECTION BEHIND THE FRONT
TONIGHT WILL RESULT IN GUSTY NORTHWEST WINDS. THE COOLER AIR MASS
COMING IN WILL HOLD LOW TEMPERATURES BELOW NORMAL.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 327 AM EDT WEDNESDAY...
HIGH PRESSURE STRENGTHENS AND STRETCHES INTO THE MIDDLE ATLANTIC
THURSDAY AND THURSDAY NIGHT. ONE FINAL SHRTWV WITH SCANT MOISTURE
CUTTING THROUGH WEST VA WILL THROW SOME CLOUDS BRIEFLY INTO SE WEST
VA LATE THURSDAY AFTERNOON BEFORE DEPARTING THURSDAY NIGHT.
FRIDAY MORNING LOOKS LIKE A CHILLY ONE WITH SOME MINS NEAR
FREEZING AT THE COLDEST SPOTS AND POTENTIALLY NEAR THE MIDDLE 30S
ACROSS THE VIRGINIA PIEDMONT WHICH MAY LEAD TO SOME PATCHY FROST.
AS THE HIGH DEPARTS LATER FRIDAY SOME HIGH CLOUDS ARRIVE BEFORE
MOISTURE INCREASES AND WINDS BEGIN TO TAKE ON AN EASTERLY
COMPONENT INTO THE WEEKEND. PINPOINTING POPS FOR THIS WEEKEND
REALLY TOUGH RIGHT NOW WITH MODELS NOT SHOWING A LOT OF MEASURABLE
PRECIP SAVE THE NC/VA BORDER. BUT...WOULD THINK SE TO ESE FLOW AND
ABUNDANT MOISTURE WOULD BE ENOUGH FOR SOME LIGHT RAIN SATURDAY OR
SATURDAY NIGHT...FURTHER NORTH THAN MOST MODELS DEPICT. THE 0Z
ECMWF CONTINUES TO BE THE WETTEST SOLUTION BUT EVEN IT HAS NOW
SHIFTED THE PRECIP FURTHER SOUTH. NONETHELESS...GUIDANCE FOR MAX T
SATURDAY SEEMED SEVERAL DEGREES TOO WARM CONSIDERING ALL OF THE
ABOVE...SO WENT BELOW THE MEX MOS NUMBERS...SUBSTANTIALLY SO IN
THE TYPICAL WEDGE AREAS.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 355 PM EDT THURSDAY...
CONSIDERABLE DIFFERENCES REMAIN AMONG THE GFS AND ECMWF DURING THE
EXTENDED PERIODS...BUT ANY WAY YOU LOOK AT IT...IT IS GOING TO BE
WET AND UNSEASONABLY COOL. A VIGOROUS SOUTHERN STREAM DISTURBANCE
IS STILL SLATED TO MOVE INTO THE REGION FROM THE WEST. IT IS THE
SUBSEQUENT MOVEMENT/DEVELOPMENT OF THIS SYSTEM THROUGH THE WEEKEND
INTO EARLY NEXT WEEK THAT BECOMES THE QUESTION. THE GFS HAS IN
GENERAL SHOWN MORE CONSISTENCY WITH THE EVOLUTION OF THIS SYSTEM
THAN THE ECMWF. EACH RUN OF THE ECMWF DEVELOPS A CUTOFF IN A
DIFFERENT LOCATION...WHICH IS RESULTING IN LOWERING CONFIDENCE IN
ANY ONE SOLUTION FROM THAT MODEL.
HOWEVER...BOTH THE GFS AND ECMWF GIVE SOME HINT OF AT LEAST WEAK
CUTOFF LOW PRESSURE DEVELOPING ACROSS THE SOUTHEAST STATES IN A
WEAKNESS AREA. THEREFORE...HAVE KEPT LIKELY POPS SAT-SUN...THEN
TAPER TO MOSTLY CHANCE POPS DURING THE LATER PERIODS. THE LATEST
ECMWF HAS DEFINITELY TRENDED TOWARD A DRIER/WEAKER SOLUTION.
INSTABILITY IS NIL THROUGH THE PERIOD AND WITH BOTH MODELS THERE
IS A STRONG SIGNAL FOR A WEDGE REINFORCED...HENCE IN SITU AS WELL.
HAVE FAVORED THE MUCH COOLER ECMWF GRIDS THROUGHOUT THE EXTENDED
PERIODS.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 145 AM EDT WEDNESDAY...
ONCE MIXING BEGINS THIS MORNING THE WIND WILL INCREASE FROM THE
SOUTHWEST AHEAD OF THE APPROACHING COLD FRONT. BUFKIT INDICATED
JET WOULD BE IN THE 25 TO 35 KNOT RANGE. CLOUDS WILL INCREASE
THROUGHOUT THE DAY...ALTHOUGH CEILINGS WILL REMAIN VFR.
LOW PRESSURE MOVING ACROSS THE GREAT LAKES WILL BRING A COLD
FRONT THROUGH THE REGION THIS EVENING. EXPECT FRONTAL PASSAGE AND
WIND SHIFT TO THE NORTHWEST AROUND 23Z/7PM AT BLF AND LWB AND
BETWEEN 00Z/8PM AND 03Z/11PM AT BCB/ROA/DAN/LYH. BRIEF WIND GUSTS
TO 35 KNOTS ARE POSSIBLE WITH THE STRONGER SHOWERS AND
THUNDERSTORMS ALONG THE FRONT. THE SHOWERS MAY NEVER REACH DAN AND LYH
WITH NORTHWEST DOWNSLOPE WINDS AND THE PRECIPITATION MAINLY BEHIND
THE BOUNDARY.
WINDS WILL STILL GUST 20 TO 25 KNOTS FOR A FEW HOURS BEHIND THE
FRONT DUE TO PRESSURE RISES AND COLD AIR ADVECTION. CEILINGS MAY
DROP TO MVFR AT BLF AND LWB BEHIND THE FRONT.CONFIDENCE IS
MODERATE THAT CEILINGS WILL STILL BE MVFR BY 12Z THURSDAY.
HIGH PRESSURE WILL BUILD IN QUICKLY IN THE WAKE OF THE COLD FRONT
FOR THURSDAY AND FRIDAY. ANY MVFR CEILINGS WILL BE WEST OF THE
BLUE RIDGE...AND WILL IMPROVE TO VFR THURSDAY MORNING.
THIS WEEKEND WILL BE UNSETTLED WITH PERIODS OF SHOWERS BEGINNING
SATURDAY AFTERNOON. EXPECT PERIODS OF IFR/MVFR CONDITIONS SATURDAY
AFTERNOON THROUGH THE REST OF THE WEEKEND.
&&
.FIRE WEATHER...
AS OF 515 AM EDT WEDNESDAY...
BREEZY SOUTHWEST WINDS AHEAD OF AN APPROACHING COLD FRONT
TODAY. SOUTHWEST WINDS OF 10 TO 15 MPH WITH GUSTS OF 20 TO 30 MPH
ARE LIKELY BY THIS AFTERNOON. THE WIND WILL ABRUPTLY SHIFT TO THE
NORTHWEST WITH THE PASSAGE OF THE FRONT THIS EVENING. THE FRONT
IS EXPECTED TO CROSS THE MOUNTAINS BETWEEN 6-9PM...THEN MOVE EAST
OF THE BLUE RIDGE AND ACROSS THE PIEDMONT BEFORE MIDNIGHT.
THE CHANCE OF RAIN MOVES BACK INTO THE FORECAST AREA AGAIN ON
SATURDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/PM/WP
SHORT TERM...KM
LONG TERM...RAB
AVIATION...AMS
FIRE WEATHER...AMS/PM
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1035 AM MDT WED APR 24 2013
.UPDATE...
&&
.SHORT TERM...CURRENT FORECASTS LOOK ON TRACK. WATER VAPOR LOOPS
CURRENTLY SHOWING WEAK ELONGATED DISTURBANCE MOVING ACROSS
MOUNTAINS. SATELLITE INDICATING CLOUDS HAVE INCREASED OVER THE
MOUNTAINS AND NORTHWEST FLOW ALOFT PROVIDING SOME OROGRAPHICS. AS
A RESULT...AREAS OF LIGHT SNOW OCCURRING ALONG HIGHER MOUNTAINS.
FROM WEB CAMS...THE LIGHT SNOW LOOKS TO BE CONFINED TO THE WEST
AND NORTHWEST FACING SLOPES OF THE CONTINENTAL DIVIDE...MAINLY
OVER SUMMIT AND GRAND COUNTIES. DISTURBANCE EXPECTED TO MOVE
ACROSS PLAINS DURING THE AFTERNOON WITH LATEST RUC SHOWING THE
MOISTURE OVER MOUNTAINS DECREASING. WILL MAINTAIN THE SLIGHT
CHANCE OF SNOW. NO WEATHER OR POPS FOR PLAINS THOUGH SOME VIRGA
POSSIBLE ACROSS FAR NORTHEAST CORNER DURING THE AFTERNOON AS
DISTURBANCE MOVES OVER AREA. AFTERNOON HIGHS WILL BE TRICKY WITH
VARYING AMOUNTS OF SNOW COVER. WILL MAINTAIN EXPECTED HIGHS AT
THIS TIME...AND ADJUST AS NEEDED.
.AVIATION...WINDS ACROSS AREA AIRPORTS STILL MAINTAINING A
SOUTHWEST DIRECTION. LATEST MODELS SHOWING WINDS SHIFTING TO THE
NORTHWEST IN THE 18-19Z TIME FRAME...WILL MAINTAIN CURRENT TAF
TRENDS. WINDS SHOULD BECOME A BIT MORE NORTHEAST BY 01Z AS WEAK
ANTICYCLONE TRIES TO DEVELOP ACROSS WELD COUNTY. SOUTHERLY
DRAINAGE FLOW TO DEVELOP DURING THE EVENING. SOME INCREASE IN MID
LEVEL CLOUD DURING THE AFTERNOON...CEILINGS SHOULD REMAIN ABOVE
12000 FEET. VFR TO CONTINUE.
&&
.PREV DISCUSSION... /ISSUED 250 AM MDT WED APR 24 2013/
SHORT TERM...A WEAK DISTURBANCE IN NW FLOW ALOFT WILL PASS OVER
THE AREA TODAY HOWEVER CROSS-SECTIONS SHOW LIMITED MOISTURE WITH
THIS FEATURE. THUS WILL ONLY MENTION A SLIGHT CHC OF -SHSN IN THE
MTNS WITH DRY CONDITIONS ESLEWHERE ALTHOUGH THERE COULD BE SOME
VIRGA OVER THE FAR NERN PLAINS BY LATE AFTN. AS FOR TEMPS THE
BEST SNOW COVER WAS OVER ERN ELBERT...LINCOLN...WASHINGTON AND ERN
PART OF ADAMS AND ARAPAHOE COUNTIES. WILL KEEP HIGHS IN THESE
AREAS IN THE 45 TO 50 DEGREE RANGE. OTHERWISE THERE WAS LIMITED
SNOW COVER ELSEWHERE SO WILL HAVE HIGHS IN THE LOWER TO MID 50S
OVER THE REST OF NERN CO.
LONG TERM...ZONAL FLOW IS TO DOMINATE ACROSS THE FORECAST AREA
THURSDAY INTO THURSDAY EVENING. A WEAK UPPER TROUGH IS PROGGED
ACROSS COLORADO THURSDAY NIGHT INTO FRIDAY WITH WEAK NORTHERLY
FLOW ALOFT FOR THE CWA FRIDAY NIGHT. THERE IS WEAK UPWARD QG
VERTICAL MOTION THURSDAY AND THURSDAY EVENING...THEN THE SYNOPTIC
SCALE ENERGY IS BENIGN ON FRIDAY AND FRIDAY NIGHT. THE BOUNDARY
LAYER FLOW LOOKS TO ADHERE TO NORMAL DUIRNAL PATTERNS FOR
THURSDAY...THEN A WEAK COLD FRONT AND WEAK UPSLOPE IS PROGGED
THURSDAY NIGHT AND FRIDAY. BY FRIDAY NIGHT...NORMAL PATTERNS ARE
BACK. THE MODELS HAVE INCREASING UPPER AND MID LEVEL MOISTURE ON
THURSDAY INTO THURSDAY NIGHT. THERE NEVER REALLY IS ANY LOW LEVEL
MOISTURE TO SPEAK OF. THINGS DRY OUT BY FRIDAY MORNING. THERE IS A
TAD OF MEASURABLE PRECIPITATION ON THE QPF FIELDS THURSDAY
AFTERNOON AND FRIDAY NIGHT...BUT ONLY OVER THE SOUTHERN CWA. THERE
IS LIMITED CAPE OVER THE MOUNTAINS...FOOTHILLS...AND PALMER RIDGE
LATE DAY THURSDAY. THERE IS EVEN LESS FOR LATE DAY FRIDAY. FOR
POPS...WILL KEEP PRETTY MUCH WHAT THE GOING GFE GRIDS SHOW..."20%"
OVER THE SOUTHERN CWA THURSDAY AFTERNOON AND EVENING. FOR
TEMPERATURES...THURSDAY`S HIGHS ARE 5-6 C WARMER THAN TODAY`S.
FRIDAY`S HIGHS ARE CLOSE TO THURSDAY`S WITH THE WEAK FRONT THAT IS
PROGGED THURSDAY NIGHT. FOR THE LATER DAYS...SATURDAY THROUGH
TUESDAY...THE NORTHWESTERLY FLOW ALOFT BECOMES ZONAL BY SATURDAY
NIGHT. THIS INCREASES ON SUNDAY...THEN MODELS HAVE A WEAK BROAD
UPPER TROUGH...MAINLY NORTH OF COLORADO...FOR MONDAY AFTERNOON AND
NIGHT. PRETTY STRONG NORTHWESTERLY FLOW ALOFT IS PROGGED TUESDAY.
MOISTURE IS FAIR ON GFS...AND POOR ON THE ECMWF. NO POPS RIGHT
NOW.
AVIATION...VFR THRU TONIGHT ALTHOUGH THERE COULD BE A BRIEF CLOUD
DECK DOWN TO 10000 FT AS SOME MID LEVEL MOVES ACROSS LATER THIS
MORNING INTO THE MID AFTN HOURS. DRAINAGE WINDS EARLY THIS
MORNING MAY BECOME LIGHT NNE BY 15Z. BY EARLY AFTN THEY SHOULD
BECOME MORE NNW WITH AVERAGE SPEEDS AROUND 10 KTS. BY EARLY
EVENING WINDS SHOULD GRADUALLY BECOME SLY AND CONTINUE THAT WAY
OVERNIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....RJK
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS ALBANY NY
344 PM EDT WED APR 24 2013
.SYNOPSIS...
A COLD FRONT WILL SWEEP ACROSS THE REGION TONIGHT...WITH
SHOWERS...ISOLATED THUNDER AND POSSIBLE GUSTY WINDS. COOLER AIR
WILL FOLLOW AS HIGH PRESSURE WILL BUILD OVER THE EASTERN THIRD OF
THE NATION THURSDAY...THEN DRIFT SLOWLY EAST INTO THE NEW WEEK.
WEAK DISTURBANCES WILL PASS THROUGH THE REGION THURSDAY NIGHT AND
SATURDAY NIGHT...POSSIBLY PRODUCING SOME PATCHY CLOUDS AND
SCATTERED SHOWERS...BUT FOR THE MOST PART OUR WEATHER WILL BE
FAIR AND SEASONABLE WITH MODERATING TEMPERATURES THROUGH THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 145 PM EDT...MAIN CHANGE FOR THIS ESTF UPDATE WAS TO DELAY
ONSET OF POPS BY SEVERAL HOURS ASSOCIATED WITH EXPECTED BANDS OF
SHOWERS WITH SOME EMBEDDED THUNDER UNTIL THIS EVENING. MID LEVEL
CLOUDS HAVE ACTUALLY BEEN ERODING EARLY THIS AFTERNOON AHEAD OF
THE THICKER BATCH OF CLOUDS ASSOCIATED WITH THE SURFACE COLD FRONT
AND UPPER LEVEL TROUGH MOVING EAST FROM THE GREAT LAKES AND OHIO
VALLEY. LOCAL HIRES WRF AND HRRR IN GOOD AGREEMENT WITH DEPICTING
BANDS OF SHOWERS MOVING IN DURING THE EVENING HOURS.
THE WIND FIELD WILL STRENGTHEN FOR A BRIEF PERIOD OF TIME THIS
EVENING COINCIDENT WITH THE ARRIVAL OF COLD FRONT...SO ADDED
MENTION OF GUSTY WINDS TO ACCOMPANY BANDS OF SHOWERS AND SOME
THUNDER. EXPANDED THE MENTION OF ISOLATED THUNDER TO ENCOMPASS THE
ENTIRE AREA...AS LATEST GUIDANCE SHOWING ELEVATED INSTABILITY NORTH
TO THE CANADIAN BORDER. SURFACE BASED CAPE WILL BE LACKING...SO
SEVERE WEATHER NOT EXPECTED ALTHOUGH SOME STRONGER WIND GUSTS
POSSIBLY UP TO 50 MPH MAY ACCOMPANY THE SHOWERS/STORMS.
THE H850 TEMPS INCREASE +9 TO +13C AHEAD OF THE FRONT. THE H850
FLOW INCREASES FORM THE S/SW TO 40-55 KTS BY NIGHTFALL. IT WILL
BECOME BREEZY IN THE PM WITH SOUTHERLY WINDS OF 10 TO 20 MPH WITH
SOME GUSTS 30-35 MPH. MAX TEMPS IN THE U60S TO L70S WILL BE COMMON
IN THE VALLEYS...AND 60S WILL BE LIKELY OVER THE MTNS WITH SFC
DEWPTS RISING INTO THE 40S.
TONIGHT...THE BEST CHC FOR WIDESPREAD RAINFALL FROM THE FRONT
LOOKS TO BE IN THE 6 PM TO MIDNIGHT TIME FRAME. THERE IS DECENT
LOW-LEVEL CONVERGENCE ALONG AND IN THE WAKE OF THE COLD FRONT. THE
BETTER JET STREAK ALOFT RACES INTO QUEBEC...AS THE UNFAVORABLE
RIGHT FRONT QUAD OF A 125+ KT H250 JET STREAK MOVES OVER THE SRN
HALF OF THE FCST AREA...WHICH WILL DAMPEN THE PCPN A BIT SOUTH AND
EAST OF THE CAPITAL REGION.
THE THREAT FOR ISOLATED THUNDERSTORMS WAS KEPT IN UNTIL AROUND
MIDNIGHT. POPS WERE INCREASED TO LIKELY AND CATEGORICAL VALUES.
THE STEEPENING MID LEVEL LAPSE RATES...AND STRENGTHENING LOW LEVEL
JET ASSOCIATED WITH THE FRONT WARRANTED PUTTING SOME WIND GUSTS TO
30 TO 40 MPH...ESPECIALLY JUST IN THE WAKE OF THE FRONT. THE PWATS
DO EXCEED AN INCH FOR A BRIEF PERIOD OF TIME /COUPLE STANDARD
DEVIATIONS ABOVE NORMAL/...BUT DROP OFF WITH THE BLAST OF COLD
ADVECTION THAT FOLLOWS THE FRONTAL PASSAGE. QPF WILL RANGE FROM A
TENTH OF AN INCH OR SO...OVER THE SOUTHEAST CORNER OF THE FCST
AREA...TO UP TO A HALF AN INCH OVER THE NW EXTREME. SOME OF THE
RESIDUAL POST FRONTAL SHOWERS OVER THE SRN DACKS MAY TRANSITION TO
SNOW SHOWERS WITH LIGHT COATINGS TO A FEW TENTHS OF AN INCH IN A
FEW SPOTS. MIN TEMPS ARE TRICKY TIMING THE COLD ADVECTION. THERE
ARE LARGE DIFFERENCE BTWN THE NAM AND GFSMOS. THE GFS IS MUCH
COLDER BY ALMOST 10 DEGREES IN SOME LOCATIONS. LEANED CLOSER TO
THE WARMER NAM MOS GUIDANCE DUE TO ITS TRACK RECORD LATELY...AND
ACTUALLY WENT CLOSE TO THE ECM MOS GUIDANCE. LOWS EXPECTED IN THE
L40S IN THE HUDSON RIVER VALLEY...BERKS...CT RIVER VALLEY AND NW
CT...MID AND U30S ELSEWHERE...EXCEPT SOME U20S TO L30S OVER THE
SRN DACKS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/...
GOOD AGREEMENT AMONG MODEL SUITE (GFS/NAM/GEM/ECMWF) FOR THIS
PERIOD WITH SOME DIFFERENCES THU NT ON THE MAGNITUDE OF SCT
-SHRA/SHSN.
THU MRNG CDFNT IS OFF NEW ENGLAND...SFC HIGH PRESSURE BUILDING
INTO THE MID ATLC AND NYS. AT 500HPA GENERAL TROFINESS REMAINS
OVER NE..AND ANOTHER 500HPA SHORT WV LINGERS OVER LK MICHIGAN.
THU MORNING WILL BRING STRONG CAA...BUT SFC WIND GRADIENT WILL
WEAKEN QUICKLY BY MIDDAY. OTHER THAN A FEW MORNING CLOUDS RESULT
WILL BE A MOSTLY SUNNY MOST AREAS...PARTLY SUNNY HIR TRRN...COOL
SEASONABLE MID APRIL DAY WITH HIGHS 50S TO LOW 60S.
THU NT AND EARLY FRI A 500HPA SHORT WV MOVES ACROSS RGN THROUGH
500HPA TROF. THERE ONLY APPEARS TO BE A COLD POOL ASSOC WITH THIS
SHORT WV...NO CDFNT...HENCE MOST OF ITS IMPACTS ARE CONVECTIVELY
DIURNALLY DRIVEN...DIMINISHING OVERNIGHT. WHILE THE OTHER MODELS
GO WITH THIS THINKING...THEY PRODUCE A TAD MORE QPF THAN THE DRY
NAM WITH ITS PASSAGE THU NT. IN ANY SCENARIO THE AMOUNTS ARE A
FEW HUNDREDTHS AT BEST. SO WILL CARRY CHC POPS MOST AREAS WITH
POSSIBLE SLIGHT CHC FAR N AND SE.
THIS TROF DEPARTS THE COAST BY MIDDAY FRI AND HIGH PRESSURE COVERS
THE EASTERN HALF OF USA TO LABRADOR. SOME CLOUDS MAY LINGER TILL
500 HPA SHORT WV AND ITS COLD POOL MOVES E OF FCA...AND RESULT IN
PARTLY SUNNY BUT SEASONABLE DAY.
BY SAT AND SAT NT AXIS OF SFC HIGH IS ALONG THE ATLC SEABOARD...AND
SOME DEGREE OF RETURN FLOW IS SETTING UP...ALBEIT WEAK. MORE SIG
WAA IS OCCURRING IN THE MID LEVELS AND ANOTHER WEAK 500HPA TROF IS
MOVING ACROSS RGN...WITH ENOUGH CLOUDS TO RESULT IN PARTLY SUNNY.
HWVR TEMPS WILL REBOUND INTO THE 60S WITH SOME 50S OVER HIR TRRN.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
SUNDAY SFC HIGH SHIFTS JUST OFFSHORE...AND 500HPA RIDGE GRADUALLY
BUILDS OVER EASTERN USA THROUGH WED. THIS LOCKS THE SFC HIGH ALONG
THE SEABOARD...WITH GENTLE RETURN FLOW OVER FCA THROUGH EFP.
PERIOD FEATURES SIG WAA AND TEMPS TURNING ABV NORMAL. MAX TEMPS
REACH MID 60S TO MID 70S...LOWS MID 30S TO MID 40S.
WHILE LARGELY A DRY MILD PERIOD..THERE ARE A FEW SUBTLE FEATURES
THAT COULD INCR CLOUDS FROM TIME TO TIME AND TRIGGER SOME WIDELY
SCT -SHRA. MAINLY SURGES IN WAA PARTICULARLY TO THE NW PTNS OF
FCA. ATTM ALL GUID TAKES EVOLVING TROF AND SYSTEMS OVER GRT PLAINS
WELL WEST AND SOUTH OF RGN.
WHAT APPEARS TO TO A TRUE SPRING LIKE PERIOD IS EXPECTED...AND
WILL POPULATE WITH HPC DROPPING SLIGHT CHC POOPS AS ALL
SURROUNDING OFFICES DID GIVEN THE ECMWF MASSIVE 579 DM 500 RIDGE
OVER FCA.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
VFR CONDITIONS ARE IN PLACE AT ALL TAF SITES WITH JUST SCT-BKN HIGH
LEVEL CLOUDS ACROSS THE REGION. ALTHOUGH WINDS ARE CURRENTLY RATHER
LIGHT...A SOUTHERLY BREEZE WILL INCREASE TO AROUND 10 KTS AT ALL
SITES THROUGH THE AFTERNOON HOURS.
AN APPROACHING COLD FRONT WILL BRING A BAND OF RAIN SHOWERS ACROSS
THE REGION BETWEEN 02Z-07Z TONIGHT. THE RAIN SHOULD ONLY LAST AT
ANY ONE PARTICULAR LOCATION FOR A FEW HOURS. THERE IS A SLIGHT CHC
FOR SOME RUMBLES OF THUNDER...ALTHOUGH DUE TO THE UNCERTAINTY AND
LOW PROBABILITY OF THIS OCCURRING...IT WILL NOT BE INCLUDED IN THE
TAFS AT THIS TIME. WITHIN ANY RAIN SHOWERS...VSBYS AND PERHAPS CIGS
AS WELL MAY LOWER TO MVFR RANGE. IFR CONDITIONS ARE NOT ANTICIPATED
AT THIS TIME...ALTHOUGH A BRIEF DROP TO IFR CONDITIONS CANNOT BE
TOTALLY RULED OUT...ESP IF ANY THUNDERSTORM DO DEVELOP.
WITHIN AND JUST BEHIND THE RAIN SHOWERS...THE WINDS WILL SWITCH TO
W-SW DIRECTION AND BECOME RATHER GUSTY. SOME GUSTS OF AROUND 25 KTS
ARE POSSIBLE...ESP FOR KALB/KPSF.
CLOUDS SHOULD START TO SCT OUT AFTER ABOUT 06Z-07Z...WITH VFR
CONDITIONS RETURNING...AND SKIES WILL BE CLEAR BY MID THURSDAY
MORNING. IN ADDITION...WINDS WILL DECREASE ON THURSDAY MORNING TO
AROUND 5-10 KTS AFTER SUNRISE AS HIGH PRESSURE BUILDS INTO THE
REGION...ALTHOUGH THERE STILL MAY BE A FEW LINGERING HIGHER WIND
GUSTS AT KPSF/KALB THROUGH ABOUT NOON OR SO.
OUTLOOK...
THU-MON...VFR...NO SIG WX.
&&
.FIRE WEATHER...
A COLD FRONT WILL SWEEP ACROSS THE REGION TONIGHT...WITH
SHOWERS...ISOLATED THUNDER AND POSSIBLE GUSTY WINDS. COOLER AIR
WILL FOLLOW AS HIGH PRESSURE WILL BUILD OVER THE EASTERN THIRD OF
THE NATION THURSDAY...THEN DRIFT SLOWLY EAST INTO THE NEW WEEK.
WEAK DISTURBANCES WILL PASS THROUGH THE REGION THURSDAY NIGHT AND
SATURDAY NIGHT...POSSIBLY PRODUCING SOME PATCHY CLOUDS AND
SCATTERED SHOWERS...BUT FOR THE MOST PART CONDITIONS WILL BE
FAIR...DRY AND SEASONABLE WITH MODERATING TEMPERATURES THROUGH THE
WEEKEND.
RH VALUES RISE TO 75 TO 100 PERCENT TONIGHT. THE RH VALUES WILL
DROP TO 20-30 PERCENT BY THURSDAY AFTERNOON...RISING TO 60-75
PERCENT THURSDAY NIGHT...FALLING TO 20 TO 35 PERCENT FRIDAY
AFTERNOON.
THE WINDS WILL SHIFT TO THE SOUTHWEST OR WEST AT 10 TO 20 MPH
TONIGHT WITH SOME GUSTS IN THE 30 TO 40 MPH RANGE WITH THE FRONTAL
PASSAGE. THE WINDS WILL BE FROM THE NORTHWEST AT 10 TO 15 MPH WITH
A FEW LOCATIONS HAVING GUSTS TO 25 MPH ON THURSDAY DIMINISHING TO
AROUND 10 MPH DURING THE AFTERNOON.
A WETTING RAINFALL WILL OCCUR TONIGHT WITH A QUARTER TO HALF AN
INCH OF RAIN EXPECTED FROM THE CAPITAL REGION...BERKSHIRES AND
EASTERN CATSKILLS NORTHWARD...WITH LESS THAN A QUARTER OF AN INCH
POSSIBLE FURTHER SOUTH.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED OVER THE NEXT 5 DAYS.
A WIDESPREAD RAINFALL IS EXPECTED TONIGHT. QPF SHOULD BE A
QUARTER TO A HALF AN INCH OF RAINFALL WITH THIS EVENT.
DRY WEATHER WILL RETURN THURSDAY AND DOMINATE INTO THE NEW WEEK WITH
HIGH PRESSURE IN CONTROL. ISOLATED TO SCATTERED LIGHT RAIN OR SNOW
SHOWERS ARE POSSIBLE THURSDAY NIGHT.
RIVERS AND STREAMS WILL CONTINUE TO RECEDE WITH DRY WEATHER
EXPECTED THE NEXT SEVERAL DAYS BEYOND THURSDAY NIGHT.
FOR DETAILS ON SPECIFIC AREA RIVERS AND
LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE
ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION
SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...JPV
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...FRUGIS
FIRE WEATHER...SNYDER/WASULA
HYDROLOGY...FRUGIS/SNYDER/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
336 PM EDT WED APR 24 2013
.SYNOPSIS...
A COLD FRONT WILL SWEEP ACROSS THE REGION TONIGHT...WITH
SHOWERS...ISOLATED THUNDER AND POSSIBLE GUSTY WINDS. COOLER AIR
WILL FOLLOW AS HIGH PRESSURE WILL BUILD OVER THE EASTERN THIRD OF
THE NATION THURSDAY...THEN DRIFT SLOWLY EAST INTO THE NEW WEEK.
WEAK DISTURBANCES WILL PASS THROUGH THE REGION THURSDAY NIGHT AND
SATURDAY NIGHT...POSSIBLY PRODUCING SOME PATCHY CLOUDS AND
SCATTERED SHOWERS...BUT FOR THE MOST PART OUR WEATHER WILL BE
FAIR AND SEASONABLE WITH MODERATING TEMPERATURES THROUGH THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 145 PM EDT...MAIN CHANGE FOR THIS ESTF UPDATE WAS TO DELAY
ONSET OF POPS BY SEVERAL HOURS ASSOCIATED WITH EXPECTED BANDS OF
SHOWERS WITH SOME EMBEDDED THUNDER UNTIL THIS EVENING. MID LEVEL
CLOUDS HAVE ACTUALLY BEEN ERODING EARLY THIS AFTERNOON AHEAD OF
THE THICKER BATCH OF CLOUDS ASSOCIATED WITH THE SURFACE COLD FRONT
AND UPPER LEVEL TROUGH MOVING EAST FROM THE GREAT LAKES AND OHIO
VALLEY. LOCAL HIRES WRF AND HRRR IN GOOD AGREEMENT WITH DEPICTING
BANDS OF SHOWERS MOVING IN DURING THE EVENING HOURS.
THE WIND FIELD WILL STRENGTHEN FOR A BRIEF PERIOD OF TIME THIS
EVENING COINCIDENT WITH THE ARRIVAL OF COLD FRONT...SO ADDED
MENTION OF GUSTY WINDS TO ACCOMPANY BANDS OF SHOWERS AND SOME
THUNDER. EXPANDED THE MENTION OF ISOLATED THUNDER TO ENCOMPASS THE
ENTIRE AREA...AS LATEST GUIDANCE SHOWING ELEVATED INSTABILITY NORTH
TO THE CANADIAN BORDER. SURFACE BASED CAPE WILL BE LACKING...SO
SEVERE WEATHER NOT EXPECTED ALTHOUGH SOME STRONGER WIND GUSTS
POSSIBLY UP TO 50 MPH MAY ACCOMPANY THE SHOWERS/STORMS.
THE H850 TEMPS INCREASE +9 TO +13C AHEAD OF THE FRONT. THE H850
FLOW INCREASES FORM THE S/SW TO 40-55 KTS BY NIGHTFALL. IT WILL
BECOME BREEZY IN THE PM WITH SOUTHERLY WINDS OF 10 TO 20 MPH WITH
SOME GUSTS 30-35 MPH. MAX TEMPS IN THE U60S TO L70S WILL BE COMMON
IN THE VALLEYS...AND 60S WILL BE LIKELY OVER THE MTNS WITH SFC
DEWPTS RISING INTO THE 40S.
TONIGHT...THE BEST CHC FOR WIDESPREAD RAINFALL FROM THE FRONT
LOOKS TO BE IN THE 6 PM TO MIDNIGHT TIME FRAME. THERE IS DECENT
LOW-LEVEL CONVERGENCE ALONG AND IN THE WAKE OF THE COLD FRONT. THE
BETTER JET STREAK ALOFT RACES INTO QUEBEC...AS THE UNFAVORABLE
RIGHT FRONT QUAD OF A 125+ KT H250 JET STREAK MOVES OVER THE SRN
HALF OF THE FCST AREA...WHICH WILL DAMPEN THE PCPN A BIT SOUTH AND
EAST OF THE CAPITAL REGION.
THE THREAT FOR ISOLATED THUNDERSTORMS WAS KEPT IN UNTIL AROUND
MIDNIGHT. POPS WERE INCREASED TO LIKELY AND CATEGORICAL VALUES.
THE STEEPENING MID LEVEL LAPSE RATES...AND STRENGTHENING LOW LEVEL
JET ASSOCIATED WITH THE FRONT WARRANTED PUTTING SOME WIND GUSTS TO
30 TO 40 MPH...ESPECIALLY JUST IN THE WAKE OF THE FRONT. THE PWATS
DO EXCEED AN INCH FOR A BRIEF PERIOD OF TIME /COUPLE STANDARD
DEVIATIONS ABOVE NORMAL/...BUT DROP OFF WITH THE BLAST OF COLD
ADVECTION THAT FOLLOWS THE FRONTAL PASSAGE. QPF WILL RANGE FROM A
TENTH OF AN INCH OR SO...OVER THE SOUTHEAST CORNER OF THE FCST
AREA...TO UP TO A HALF AN INCH OVER THE NW EXTREME. SOME OF THE
RESIDUAL POST FRONTAL SHOWERS OVER THE SRN DACKS MAY TRANSITION TO
SNOW SHOWERS WITH LIGHT COATINGS TO A FEW TENTHS OF AN INCH IN A
FEW SPOTS. MIN TEMPS ARE TRICKY TIMING THE COLD ADVECTION. THERE
ARE LARGE DIFFERENCE BTWN THE NAM AND GFSMOS. THE GFS IS MUCH
COLDER BY ALMOST 10 DEGREES IN SOME LOCATIONS. LEANED CLOSER TO
THE WARMER NAM MOS GUIDANCE DUE TO ITS TRACK RECORD LATELY...AND
ACTUALLY WENT CLOSE TO THE ECM MOS GUIDANCE. LOWS EXPECTED IN THE
L40S IN THE HUDSON RIVER VALLEY...BERKS...CT RIVER VALLEY AND NW
CT...MID AND U30S ELSEWHERE...EXCEPT SOME U20S TO L30S OVER THE
SRN DACKS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/...
GOOD AGREEMENT AMONG MODEL SUITE (GFS/NAM/GEM/ECMWF) FOR THIS
PERIOD WITH SOME DIFFERENCES THU NT ON THE MAGNITUDE OF SCT
-SHRA/SHSN.
THU MRNG CDFNT IS OFF NEW ENGLAND...SFC HIGH PRESSURE BUILDING
INTO THE MID ATLC AND NYS. AT 500HPA GENERAL TROFINESS REMAINS
OVER NE..AND ANOTHER 500HPA SHORT WV LINGERS OVER LK MICHIGAN.
THU MORNING WILL BRING STRONG CAA...BUT SFC WIND GRADIENT WILL
WEAKEN QUICKLY BY MIDDAY. OTHER THAN A FEW MORNING CLOUDS RESULT
WILL BE A MOSTLY SUNNY MOST AREAS...PARTLY SUNNY HIR TRRN...COOL
SEASONABLE MID APRIL DAY WITH HIGHS 50S TO LOW 60S.
THU NT AND EARLY FRI A 500HPA SHORT WV MOVES ACROSS RGN THROUGH
500HPA TROF. THERE ONLY APPEARS TO BE A COLD POOL ASSOC WITH THIS
SHORT WV...NO CDFNT...HENCE MOST OF ITS IMPACTS ARE CONVECTIVELY
DIURNALLY DRIVEN...DIMINISHING OVERNIGHT. WHILE THE OTHER MODELS
GO WITH THIS THINKING...THEY PRODUCE A TAD MORE QPF THAN THE DRY
NAM WITH ITS PASSAGE THU NT. IN ANY SCENARIO THE AMOUNTS ARE A
FEW HUNDREDTHS AT BEST. SO WILL CARRY CHC POPS MOST AREAS WITH
POSSIBLE SLIGHT CHC FAR N AND SE.
THIS TROF DEPARTS THE COAST BY MIDDAY FRI AND HIGH PRESSURE COVERS
THE EASTERN HALF OF USA TO LABRADOR. SOME CLOUDS MAY LINGER TILL
500 HPA SHORT WV AND ITS COLD POOL MOVES E OF FCA...AND RESULT IN
PARTLY SUNNY BUT SEASONABLE DAY.
BY SAT AND SAT NT AXIS OF SFC HIGH IS ALONG THE ATLC SEABOARD...AND
SOME DEGREE OF RETURN FLOW IS SETTING UP...ALBEIT WEAK. MORE SIG
WAA IS OCCURRING IN THE MID LEVELS AND ANOTHER WEAK 500HPA TROF IS
MOVING ACROSS RGN...WITH ENOUGH CLOUDS TO RESULT IN PARTLY SUNNY.
HWVR TEMPS WILL REBOUND INTO THE 60S WITH SOME 50S OVER HIR TRRN.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
SUNDAY SFC HIGH SHIFTS JUST OFFSHORE...AND 500HPA RIDGE GRADUALLY
BUILDS OVER EASTERN USA THROUGH WED. THIS LOCKS THE SFC HIGH ALONG
THE SEABOARD...WITH GENTLE RETURN FLOW OVER FCA THROUGH EFP.
PERIOD FEATURES SIG WAA AND TEMPS TURNING ABV NORMAL. MAX TEMPS
REACH MID 60S TO MID 70S...LOWS MID 30S TO MID 40S.
WHILE LARGELY A DRY MILD PERIOD..THERE ARE A FEW SUBTLE FEATURES
THAT COULD INCR CLOUDS FROM TIME TO TIME AND TRIGGER SOME WIDELY
SCT -SHRA. MAINLY SURGES IN WAA PARTICULARLY TO THE NW PTNS OF
FCA. ATTM ALL GUID TAKES EVOLVING TROF AND SYSTEMS OVER GRT PLAINS
WELL WEST AND SOUTH OF RGN.
WHAT APPEARS TO TO A TRUE SPRING LIKE PERIOD IS EXPECTED...AND
WILL POPULATE WITH HPC.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
VFR CONDITIONS ARE IN PLACE AT ALL TAF SITES WITH JUST SCT-BKN HIGH
LEVEL CLOUDS ACROSS THE REGION. ALTHOUGH WINDS ARE CURRENTLY RATHER
LIGHT...A SOUTHERLY BREEZE WILL INCREASE TO AROUND 10 KTS AT ALL
SITES THROUGH THE AFTERNOON HOURS.
AN APPROACHING COLD FRONT WILL BRING A BAND OF RAIN SHOWERS ACROSS
THE REGION BETWEEN 02Z-07Z TONIGHT. THE RAIN SHOULD ONLY LAST AT
ANY ONE PARTICULAR LOCATION FOR A FEW HOURS. THERE IS A SLIGHT CHC
FOR SOME RUMBLES OF THUNDER...ALTHOUGH DUE TO THE UNCERTAINTY AND
LOW PROBABILITY OF THIS OCCURRING...IT WILL NOT BE INCLUDED IN THE
TAFS AT THIS TIME. WITHIN ANY RAIN SHOWERS...VSBYS AND PERHAPS CIGS
AS WELL MAY LOWER TO MVFR RANGE. IFR CONDITIONS ARE NOT ANTICIPATED
AT THIS TIME...ALTHOUGH A BRIEF DROP TO IFR CONDITIONS CANNOT BE
TOTALLY RULED OUT...ESP IF ANY THUNDERSTORM DO DEVELOP.
WITHIN AND JUST BEHIND THE RAIN SHOWERS...THE WINDS WILL SWITCH TO
W-SW DIRECTION AND BECOME RATHER GUSTY. SOME GUSTS OF AROUND 25 KTS
ARE POSSIBLE...ESP FOR KALB/KPSF.
CLOUDS SHOULD START TO SCT OUT AFTER ABOUT 06Z-07Z...WITH VFR
CONDITIONS RETURNING...AND SKIES WILL BE CLEAR BY MID THURSDAY
MORNING. IN ADDITION...WINDS WILL DECREASE ON THURSDAY MORNING TO
AROUND 5-10 KTS AFTER SUNRISE AS HIGH PRESSURE BUILDS INTO THE
REGION...ALTHOUGH THERE STILL MAY BE A FEW LINGERING HIGHER WIND
GUSTS AT KPSF/KALB THROUGH ABOUT NOON OR SO.
OUTLOOK...
THU-MON...VFR...NO SIG WX.
&&
.FIRE WEATHER...
A COLD FRONT WILL SWEEP ACROSS THE REGION TONIGHT...WITH
SHOWERS...ISOLATED THUNDER AND POSSIBLE GUSTY WINDS. COOLER AIR
WILL FOLLOW AS HIGH PRESSURE WILL BUILD OVER THE EASTERN THIRD OF
THE NATION THURSDAY...THEN DRIFT SLOWLY EAST INTO THE NEW WEEK.
WEAK DISTURBANCES WILL PASS THROUGH THE REGION THURSDAY NIGHT AND
SATURDAY NIGHT...POSSIBLY PRODUCING SOME PATCHY CLOUDS AND
SCATTERED SHOWERS...BUT FOR THE MOST PART CONDITIONS WILL BE
FAIR...DRY AND SEASONABLE WITH MODERATING TEMPERATURES THROUGH THE
WEEKEND.
RH VALUES RISE TO 75 TO 100 PERCENT TONIGHT. THE RH VALUES WILL
DROP TO 20-30 PERCENT BY THURSDAY AFTERNOON...RISING TO 60-75
PERCENT THURSDAY NIGHT...FALLING TO 20 TO 35 PERCENT FRIDAY
AFTERNOON.
THE WINDS WILL SHIFT TO THE SOUTHWEST OR WEST AT 10 TO 20 MPH
TONIGHT WITH SOME GUSTS IN THE 30 TO 40 MPH RANGE WITH THE FRONTAL
PASSAGE. THE WINDS WILL BE FROM THE NORTHWEST AT 10 TO 15 MPH WITH
A FEW LOCATIONS HAVING GUSTS TO 25 MPH ON THURSDAY DIMINISHING TO
AROUND 10 MPH DURING THE AFTERNOON.
A WETTING RAINFALL WILL OCCUR TONIGHT WITH A QUARTER TO HALF AN
INCH OF RAIN EXPECTED FROM THE CAPITAL REGION...BERKSHIRES AND
EASTERN CATSKILLS NORTHWARD...WITH LESS THAN A QUARTER OF AN INCH
POSSIBLE FURTHER SOUTH.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED OVER THE NEXT 5 DAYS.
A WIDESPREAD RAINFALL IS EXPECTED TONIGHT. QPF SHOULD BE A
QUARTER TO A HALF AN INCH OF RAINFALL WITH THIS EVENT.
DRY WEATHER WILL RETURN THURSDAY AND DOMINATE INTO THE NEW WEEK WITH
HIGH PRESSURE IN CONTROL. ISOLATED TO SCATTERED LIGHT RAIN OR SNOW
SHOWERS ARE POSSIBLE THURSDAY NIGHT.
RIVERS AND STREAMS WILL CONTINUE TO RECEDE WITH DRY WEATHER
EXPECTED THE NEXT SEVERAL DAYS BEYOND THURSDAY NIGHT.
FOR DETAILS ON SPECIFIC AREA RIVERS AND
LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE
ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION
SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...JPV
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...FRUGIS
FIRE WEATHER...WASULA/SNYDER
HYDROLOGY...FRUGIS/WASULA/SNYDER
AREA FORECAST DISCUSSION
NWS ALBANY NY
243 PM EDT WED APR 24 2013
.SYNOPSIS...
A COLD FRONT WILL SWEEP ACROSS THE REGION TONIGHT...WITH
SHOWERS...ISOLATED THUNDER AND POSSIBLE GUSTY WINDS. COOLER AIR
WILL FOLLOW AS HIGH PRESSURE WILL BUILD OVER THE EASTERN THIRD OF
THE NATION THURSDAY...THEN DRIFT SLOWLY EAST INTO THE NEW WEEK.
WEAK DISTURBANCES WILL PASS THROUGH THE REGION THURSDAY NIGHT AND
SATURDAY NIGHT...POSSIBLY PRODUCING SOME PATCHY CLOUDS AND
SCATTERED SHOWERS...BUT FOR THE MOST PART OUR WEATHER WILL BE
FAIR AND SEASONABLE WITH MODERATING TEMPERATURES THROUGH THE
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 145 PM EDT...MAIN CHANGE FOR THIS ESTF UPDATE WAS TO DELAY
ONSET OF POPS BY SEVERAL HOURS ASSOCIATED WITH EXPECTED BANDS OF
SHOWERS WITH SOME EMBEDDED THUNDER UNTIL THIS EVENING. MID LEVEL
CLOUDS HAVE ACTUALLY BEEN ERODING EARLY THIS AFTERNOON AHEAD OF
THE THICKER BATCH OF CLOUDS ASSOCIATED WITH THE SURFACE COLD FRONT
AND UPPER LEVEL TROUGH MOVING EAST FROM THE GREAT LAKES AND OHIO
VALLEY. LOCAL HIRES WRF AND HRRR IN GOOD AGREEMENT WITH DEPICTING
BANDS OF SHOWERS MOVING IN DURING THE EVENING HOURS.
THE WIND FIELD WILL STRENGTHEN FOR A BRIEF PERIOD OF TIME THIS
EVENING COINCIDENT WITH THE ARRIVAL OF COLD FRONT...SO ADDED
MENTION OF GUSTY WINDS TO ACCOMPANY BANDS OF SHOWERS AND SOME
THUNDER. EXPANDED THE MENTION OF ISOLATED THUNDER TO ENCOMPASS THE
ENTIRE AREA...AS LATEST GUIDANCE SHOWING ELEVATED INSTABILITY NORTH
TO THE CANADIAN BORDER. SURFACE BASED CAPE WILL BE LACKING...SO
SEVERE WEATHER NOT EXPECTED ALTHOUGH SOME STRONGER WIND GUSTS
POSSIBLY UP TO 50 MPH MAY ACCOMPANY THE SHOWERS/STORMS.
THE H850 TEMPS INCREASE +9 TO +13C AHEAD OF THE FRONT. THE H850
FLOW INCREASES FORM THE S/SW TO 40-55 KTS BY NIGHTFALL. IT WILL
BECOME BREEZY IN THE PM WITH SOUTHERLY WINDS OF 10 TO 20 MPH WITH
SOME GUSTS 30-35 MPH. MAX TEMPS IN THE U60S TO L70S WILL BE COMMON
IN THE VALLEYS...AND 60S WILL BE LIKELY OVER THE MTNS WITH SFC
DEWPTS RISING INTO THE 40S.
TONIGHT...THE BEST CHC FOR WIDESPREAD RAINFALL FROM THE FRONT
LOOKS TO BE IN THE 6 PM TO MIDNIGHT TIME FRAME. THERE IS DECENT
LOW-LEVEL CONVERGENCE ALONG AND IN THE WAKE OF THE COLD FRONT. THE
BETTER JET STREAK ALOFT RACES INTO QUEBEC...AS THE UNFAVORABLE
RIGHT FRONT QUAD OF A 125+ KT H250 JET STREAK MOVES OVER THE SRN
HALF OF THE FCST AREA...WHICH WILL DAMPEN THE PCPN A BIT SOUTH AND
EAST OF THE CAPITAL REGION.
THE THREAT FOR ISOLATED THUNDERSTORMS WAS KEPT IN UNTIL AROUND
MIDNIGHT. POPS WERE INCREASED TO LIKELY AND CATEGORICAL VALUES.
THE STEEPENING MID LEVEL LAPSE RATES...AND STRENGTHENING LOW LEVEL
JET ASSOCIATED WITH THE FRONT WARRANTED PUTTING SOME WIND GUSTS TO
30 TO 40 MPH...ESPECIALLY JUST IN THE WAKE OF THE FRONT. THE PWATS
DO EXCEED AN INCH FOR A BRIEF PERIOD OF TIME /COUPLE STANDARD
DEVIATIONS ABOVE NORMAL/...BUT DROP OFF WITH THE BLAST OF COLD
ADVECTION THAT FOLLOWS THE FRONTAL PASSAGE. QPF WILL RANGE FROM A
TENTH OF AN INCH OR SO...OVER THE SOUTHEAST CORNER OF THE FCST
AREA...TO UP TO A HALF AN INCH OVER THE NW EXTREME. SOME OF THE
RESIDUAL POST FRONTAL SHOWERS OVER THE SRN DACKS MAY TRANSITION TO
SNOW SHOWERS WITH LIGHT COATINGS TO A FEW TENTHS OF AN INCH IN A
FEW SPOTS. MIN TEMPS ARE TRICKY TIMING THE COLD ADVECTION. THERE
ARE LARGE DIFFERENCE BTWN THE NAM AND GFSMOS. THE GFS IS MUCH
COLDER BY ALMOST 10 DEGREES IN SOME LOCATIONS. LEANED CLOSER TO
THE WARMER NAM MOS GUIDANCE DUE TO ITS TRACK RECORD LATELY...AND
ACTUALLY WENT CLOSE TO THE ECM MOS GUIDANCE. LOWS EXPECTED IN THE
L40S IN THE HUDSON RIVER VALLEY...BERKS...CT RIVER VALLEY AND NW
CT...MID AND U30S ELSEWHERE...EXCEPT SOME U20S TO L30S OVER THE
SRN DACKS.
&&
.SHORT TERM /THURSDAY THROUGH SUNDAY/...
GOOD AGREEMENT AMONG MODEL SUITE (GFS/NAM/GEM/ECMWF) FOR THIS
PERIOD WITH SOME DIFFERENCES THU NT ON THE MAGNITUDE OF SCT
-SHRA/SHSN.
THU MRNG CDFNT IS OFF NEW ENGLAND...SFC HIGH PRESSURE BUILDING
INTO THE MID ATLC AND NYS. AT 500HPA GENERAL TROFINESS REMAINS
OVER NE..AND ANOTHER 500HPA SHORT WV LINGERS OVER LK MICHIGAN.
THU MORNING WILL BRING STRONG CAA...BUT SFC WIND GRADIENT WILL
WEAKEN QUICKLY BY MIDDAY. OTHER THAN A FEW MORNING CLOUDS RESULT
WILL BE A MOSTLY SUNNY MOST AREAS...PARTLY SUNNY HIR TRRN...COOL
SEASONABLE MID APRIL DAY WITH HIGHS 50S TO LOW 60S.
THU NT AND EARLY FRI A 500HPA SHORT WV MOVES ACROSS RGN THROUGH
500HPA TROF. THERE ONLY APPEARS TO BE A COLD POOL ASSOC WITH THIS
SHORT WV...NO CDFNT...HENCE MOST OF ITS IMPACTS ARE CONVECTIVELY
DIURNALLY DRIVEN...DIMINISHING OVERNIGHT. WHILE THE OTHER MODELS
GO WITH THIS THINKING...THEY PRODUCE A TAD MORE QPF THAN THE DRY
NAM WITH ITS PASSAGE THU NT. IN ANY SCENARIO THE AMOUNTS ARE A
FEW HUNDREDTHS AT BEST. SO WILL CARRY CHC POPS MOST AREAS WITH
POSSIBLE SLIGHT CHC FAR N AND SE.
THIS TROF DEPARTS THE COAST BY MIDDAY FRI AND HIGH PRESSURE COVERS
THE EASTERN HALF OF USA TO LABRADOR. SOME CLOUDS MAY LINGER TILL
500 HPA SHORT WV AND ITS COLD POOL MOVES E OF FCA...AND RESULT IN
PARTLY SUNNY BUT SEASONABLE DAY.
BY SAT AXIS OF SFC HIGH IS ALONG THE ATLC SEABOARD...AND SOME
DEGREE OF RETURN FLOW IS SETTING UP...ALBIET WEAK. MORE SIG WAA IS
OCCURRING IN THE MID LEVELS AND ANOTHER WEAK 500HPA TROF IS MOVING
ACROSS RGN...WITH ENOUGH CLOUDS TO RESULT IN PARTLY SUNNY. HWVR
TEMPS WILL REBOUND INTO THE 60S WITH SOME 50S OVER HIR TRRN.
SAT NT AND SUN SFC HIGH SHIFTS OFFSHORE...AND WEAK 500HPA RIDGE
BUILDS INTO NY AND NEW ENG. WAA ACCELERATES IN RETURN FLOW...BUT
AGAIN IT REMAINS WEAK. TEMPS MODERATE A NOTCH OR TWO MORE AS HIGHS
REACH MID 60S TO LOW 70S.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
RATHER UNUSUAL TO BE FORECASTING AN ENTIRELY DRY LONG TERM
PERIOD...HOWEVER THAT IS THE CASE WITH THIS LONG TERM FORECAST.
HIGH PRESSURE WILL DOMINATE OUR WEATHER INITIALLY BUILDING AT THE
SURFACE AND THEN ALOFT AS WELL BY MONDAY AND TUESDAY. THE
STRENGTHENING HIGH PRESSURE SYSTEM WILL KEEP ANY MOISTURE WHICH
TRIES TO LIFT NORTHWARD WELL SOUTH OF OUR REGION.
OVERALL EXPECT TEMPS IN THE LONG TERM PERIOD TO AVERAGE SLIGHTLY
ABOVE NORMAL WITH PRECIPITATION BELOW NORMAL.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR CONDITIONS ARE IN PLACE AT ALL TAF SITES WITH JUST SCT-BKN HIGH
LEVEL CLOUDS ACROSS THE REGION. ALTHOUGH WINDS ARE CURRENTLY RATHER
LIGHT...A SOUTHERLY BREEZE WILL INCREASE TO AROUND 10 KTS AT ALL
SITES THROUGH THE AFTERNOON HOURS.
AN APPROACHING COLD FRONT WILL BRING A BAND OF RAIN SHOWERS ACROSS
THE REGION BETWEEN 02Z-07Z TONIGHT. THE RAIN SHOULD ONLY LAST AT
ANY ONE PARTICULAR LOCATION FOR A FEW HOURS. THERE IS A SLIGHT CHC
FOR SOME RUMBLES OF THUNDER...ALTHOUGH DUE TO THE UNCERTAINTY AND
LOW PROBABILITY OF THIS OCCURRING...IT WILL NOT BE INCLUDED IN THE
TAFS AT THIS TIME. WITHIN ANY RAIN SHOWERS...VSBYS AND PERHAPS CIGS
AS WELL MAY LOWER TO MVFR RANGE. IFR CONDITIONS ARE NOT ANTICIPATED
AT THIS TIME...ALTHOUGH A BRIEF DROP TO IFR CONDITIONS CANNOT BE
TOTALLY RULED OUT...ESP IF ANY THUNDERSTORM DO DEVELOP.
WITHIN AND JUST BEHIND THE RAIN SHOWERS...THE WINDS WILL SWITCH TO
W-SW DIRECTION AND BECOME RATHER GUSTY. SOME GUSTS OF AROUND 25 KTS
ARE POSSIBLE...ESP FOR KALB/KPSF.
CLOUDS SHOULD START TO SCT OUT AFTER ABOUT 06Z-07Z...WITH VFR
CONDITIONS RETURNING...AND SKIES WILL BE CLEAR BY MID THURSDAY
MORNING. IN ADDITION...WINDS WILL DECREASE ON THURSDAY MORNING TO
AROUND 5-10 KTS AFTER SUNRISE AS HIGH PRESSURE BUILDS INTO THE
REGION...ALTHOUGH THERE STILL MAY BE A FEW LINGERING HIGHER WIND
GUSTS AT KPSF/KALB THROUGH ABOUT NOON OR SO.
OUTLOOK...
THU-MON...VFR...NO SIG WX.
&&
.FIRE WEATHER...
A COLD FRONT WILL BRING SHOWERS AND ISOLATED THUNDERSTORMS TO
EASTERN NEW YORK AND WESTERN NEW ENGLAND LATE THIS AFTERNOON INTO
THE OVERNIGHT PERIOD. HIGH PRESSURE WILL BRIEFLY BUILD IN ON
THURSDAY WITH AN UPPER LEVEL DISTURBANCE PRODUCING SOME ISOLATED
TO SCATTERED RAIN AND SNOW SHOWERS.
RH VALUES WILL LOWER TO 30 TO 40 PERCENT LATE THIS
AFTERNOON...AND THEN RISE TO 75 TO 100 PERCENT TONIGHT. THE RH VALUES
WILL DROP TO 20-30 PERCENT BY THURSDAY AFTERNOON.
THE WINDS WILL INCREASE FROM THE SOUTH AT 10 TO 20 MPH WITH SOME
GUSTS TO 30 MPH TODAY. THE WINDS WILL SHIFT TO THE SOUTHWEST OR WEST
AT 10 TO 20 MPH TONIGHT WITH SOME GUSTS IN THE 30 TO 40 MPH RANGE
WITH THE FRONTAL PASSAGE. THE WINDS WILL BE FROM THE NORTHWEST AT
10 TO 15 MPH WITH A FEW LOCATIONS HAVING GUSTS TO 25 MPH ON
THURSDAY.
A WETTING RAINFALL WILL OCCUR LATE THIS AFTERNOON INTO TONIGHT
WITH A QUARTER TO HALF AN INCH OF RAIN EXPECTED FROM THE CAPITAL
REGION...BERKSHIRES AND EASTERN CATSKILLS NORTHWARD...WITH LESS
THAN A QUARTER OF AN INCH POSSIBLE FURTHER SOUTH.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED OVER THE NEXT 5 DAYS.
THE NEXT WIDESPREAD RAINFALL IS EXPECTED LATE THIS AFTERNOON INTO
TONIGHT. THE HPC QPF HAS LOWERED A BIT WITH GENERALLY A QUARTER TO
A HALF AN INCH OF RAINFALL FROM THE CAPITAL
REGION...BERKSHIRES...AND THE EASTERN CATSKILLS NORTHWARD...WITH
LESS THAN A QUARTER INCH FOR MOST LOCATIONS TO THE SOUTH. SNOWMELT
WILL CONTINUE ACROSS THE ADIRONDACKS AND SOUTHERN GREENS ON
WEDNESDAY...DUE TO MAX TEMPS REACHING INTO THE 60S AND DEWPOINTS
GETTING INTO THE 40S. DESPITE THE SNOWMELT...WHICH IS MUCH MORE
LIMITED DUE TO THE SMALLER AREAL COVERAGE...THE EXPECTED RAINFALL
LOOKS LIGHT ENOUGH TO AVOID ANY ISOLATED HYDROLOGIC ISSUES IN
THOSE AREAS.
DRY WEATHER WILL RETURN FOR THURSDAY WITH HIGH PRESSURE IN
CONTROL. ISOLATED TO SCATTERED LIGHT RAIN OR SNOW SHOWERS MAY
RETURN FOR THURSDAY NIGHT FOR LOCATIONS NORTH OF THE MID HUDSON
VALLEY AND NW CT. RIVERS AND STREAMS WILL CONTINUE TO RECEDE WITH
DRY WEATHER EXPECTED THE NEXT SEVERAL DAYS BEYOND THURSDAY NIGHT.
FOR DETAILS ON SPECIFIC AREA RIVERS AND
LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE
ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION
SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...JPV
SHORT TERM...SNYDER
LONG TERM...11
AVIATION...FRUGIS
FIRE WEATHER...WASULA
HYDROLOGY...FRUGIS/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
144 PM EDT WED APR 24 2013
.SYNOPSIS...
A MILDER AIR MASS WILL YIELD ABOVE NORMAL TEMPERATURES
THIS AFTERNOON BEFORE A COLD FRONT ARRIVES WITH SHOWERS...AND
PERHAPS A FEW THUNDERSTORMS...IN THE EVENING. HIGH PRESSURE WILL
BRIEFLY BUILD INTO THE REGION WITH SEASONABLE TEMPERATURES FOR
THURSDAY. A STRONG UPPER LEVEL DISTURBANCE MAY BRING ISOLATED TO
SCATTERED RAIN AND SNOW SHOWERS TO PARTS OF EASTERN NEW YORK AND
WESTERN NEW ENGLAND THURSDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 145 PM EDT...MAIN CHANGE FOR THIS ESTF UPDATE WAS TO DELAY
ONSET OF POPS BY SEVERAL HOURS ASSOCIATED WITH EXPECTED BANDS OF
SHOWERS WITH SOME EMBEDDED THUNDER UNTIL THIS EVENING. MID LEVEL
CLOUDS HAVE ACTUALLY BEEN ERODING EARLY THIS AFTERNOON AHEAD OF
THE THICKER BATCH OF CLOUDS ASSOCIATED WITH THE SURFACE COLD FRONT
AND UPPER LEVEL TROUGH MOVING EAST FROM THE GREAT LAKES AND OHIO
VALLEY. LOCAL HIRES WRF AND HRRR IN GOOD AGREEMENT WITH DEPICTING
BANDS OF SHOWERS MOVING IN DURING THE EVENING HOURS.
THE WIND FIELD WILL STRENGTHEN FOR A BRIEF PERIOD OF TIME THIS
EVENING COINCIDENT WITH THE ARRIVAL OF COLD FRONT...SO ADDED
MENTION OF GUSTY WINDS TO ACCOMPANY BANDS OF SHOWERS AND SOME
THUNDER. EXPANDED THE MENTION OF ISOLATED THUNDER TO ENCOMPASS THE
ENTIRE AREA...AS LATEST GUIDANCE SHOWING ELEVATED INSTABILITY NORTH
TO THE CANADIAN BORDER. SURFACE BASED CAPE WILL BE LACKING...SO
SEVERE WEATHER NOT EXPECTED ALTHOUGH SOME STRONGER WIND GUSTS
POSSIBLY UP TO 50 MPH MAY ACCOMPANY THE SHOWERS/STORMS.
THE H850 TEMPS INCREASE +9 TO +13C AHEAD OF THE FRONT. THE H850
FLOW INCREASES FORM THE S/SW TO 40-55 KTS BY NIGHTFALL. IT WILL
BECOME BREEZY IN THE PM WITH SOUTHERLY WINDS OF 10 TO 20 MPH WITH
SOME GUSTS 30-35 MPH. MAX TEMPS IN THE U60S TO L70S WILL BE COMMON
IN THE VALLEYS...AND 60S WILL BE LIKELY OVER THE MTNS WITH SFC
DEWPTS RISING INTO THE 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...THE BEST CHC FOR WIDESPREAD RAINFALL FROM THE FRONT
LOOKS TO BE IN THE 6 PM TO MIDNIGHT TIME FRAME. THERE IS DECENT
LOW-LEVEL CONVERGENCE ALONG AND IN THE WAKE OF THE COLD FRONT. THE
BETTER JET STREAK ALOFT RACES INTO QUEBEC...AS THE UNFAVORABLE
RIGHT FRONT QUAD OF A 125+ KT H250 JET STREAK MOVES OVER THE SRN
HALF OF THE FCST AREA...WHICH WILL DAMPEN THE PCPN A BIT SOUTH AND
EAST OF THE CAPITAL REGION.
THE THREAT FOR ISOLATED THUNDERSTORMS WAS KEPT IN UNTIL AROUND
MIDNIGHT. POPS WERE INCREASED TO LIKELY AND CATEGORICAL VALUES.
THE STEEPENING MID LEVEL LAPSE RATES...AND STRENGTHENING LOW LEVEL
JET ASSOCIATED WITH THE FRONT WARRANTED PUTTING SOME WIND GUSTS TO
30 TO 40 MPH...ESPECIALLY JUST IN THE WAKE OF THE FRONT. THE PWATS
DO EXCEED AN INCH FOR A BRIEF PERIOD OF TIME /COUPLE STANDARD
DEVIATIONS ABOVE NORMAL/...BUT DROP OFF WITH THE BLAST OF COLD
ADVECTION THAT FOLLOWS THE FRONTAL PASSAGE. QPF WILL RANGE FROM A
TENTH OF AN INCH OR SO...OVER THE SOUTHEAST CORNER OF THE FCST
AREA...TO UP TO A HALF AN INCH OVER THE NW EXTREME. SOME OF THE
RESIDUAL POST FRONTAL SHOWERS OVER THE SRN DACKS MAY TRANSITION TO
SNOW SHOWERS WITH LIGHT COATINGS TO A FEW TENTHS OF AN INCH IN A
FEW SPOTS. MIN TEMPS ARE TRICKY TIMING THE COLD ADVECTION. THERE
ARE LARGE DIFFERENCE BTWN THE NAM AND GFSMOS. THE GFS IS MUCH
COLDER BY ALMOST 10 DEGREES IN SOME LOCATIONS. LEANED CLOSER TO
THE WARMER NAM MOS GUIDANCE DUE TO ITS TRACK RECORD LATELY...AND
ACTUALLY WENT CLOSE TO THE ECM MOS GUIDANCE. LOWS EXPECTED IN THE
L40S IN THE HUDSON RIVER VALLEY...BERKS...CT RIVER VALLEY AND NW
CT...MID AND U30S ELSEWHERE...EXCEPT SOME U20S TO L30S OVER THE
SRN DACKS.
THURSDAY...HIGH PRESSURE QUICKLY RIDGES IN FROM THE SOUTH AND WEST
WITH A BRIEF PERIOD OF DRY WEATHER...AS A POTENT SHORT-WAVE TROUGH
QUICKLY MOVES TOWARDS THE REGION FROM THE GREAT LAKES REGION. THIS
DAY WILL BE SEASONABLY WARM AND DRY WITH H850 TEMPS IN THE 0C TO
-4C RANGE OVER THE REGION. EXPECT U50S TO L60S IN THE
VALLEYS...AND U40S TO M50S OVER THE HIGHER TERRAIN.
THURSDAY NIGHT...TRICKY DYNAMIC SHORT-WAVE LACKING ROBUST LOW-
LEVEL MOISTURE TO WORK WITH. THE NAM HAS THE TROUGH PASS THROUGH
FAIRLY DRY. THE GFS/ECMWF CONTINUE TO PAINT LIGHT AMOUNTS OF QPF
OF A FEW HUNDREDTHS TO A TENTH OF AN INCH FROM THE ERN
CATSKILLS...CAPITAL REGION...NRN BERKS NORTHWARD. THE DIFFERENTIAL
CYCLONIC VORTICITY WILL TRIGGER SOME ISOLD-SCT RAIN AND SNOW
SHOWERS. THERE WILL LIKELY BE A QUICK SHOT OF RADIATIONAL COOLING
AHEAD OF THIS POTENT SHORT-WAVE WITH TEMPS FALLING INTO THE M20S
TO M30S ACROSS THE REGION. COATING TO HALF INCH SNOW AMOUNTS WILL
BE POSSIBLE ESPECIALLY FOR ELEVATIONS 500 FT AND GREATER...A
LITTLE WET SNOW MIGHT ALSO OCCUR AT THE VALLEY FLOOR LOCATIONS.
FRIDAY...LOW AND MID LEVEL HEIGHTS QUICKLY RISE AS THE SHORT-WAVE
TROUGH ZIPS BY NRN NEW ENGLAND BY THE PM. SFC HIGH PRESSURE BUILDS
IN FROM THE OHIO VALLEY...AND THE GREAT LAKES REGION WITH FAIR AND
DRY WX FOR THE AFTERNOON. EXPECT HIGHS IN THE L60S IN THE CAPITAL
REGION...MID HUDSON VALLEY...CNTRL AND SRN TACONICS...AND NW CT.
MID AND U50S WILL PREVAIL IN ALL OTHER LOCATIONS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
RATHER UNUSUAL TO BE FORECASTING AN ENTIRELY DRY LONG TERM
PERIOD...HOWEVER THAT IS THE CASE WITH THIS LONG TERM FORECAST.
HIGH PRESSURE WILL DOMINATE OUR WEATHER INITIALLY BUILDING AT THE
SURFACE AND THEN ALOFT AS WELL BY MONDAY AND TUESDAY. THE
STRENGTHENING HIGH PRESSURE SYSTEM WILL KEEP ANY MOISTURE WHICH
TRIES TO LIFT NORTHWARD WELL SOUTH OF OUR REGION.
EXPECT HIGHS ON SATURDAY TO BE IN THE UPPER 50S TO MID 60S WITH
HIGHS SUNDAY THROUGH TUESDAY MAINLY IN THE 60S TO AROUND 70. LOWS
FRIDAY NIGHT ARE EXPECTED TO RANGE FROM THE MID 20S TO MID 30S WITH
LOWS SATURDAY NIGHT IN THE 30S TO AROUND 40 AND LOWS SUNDAY NIGHT
AND MONDAY NIGHT IN THE UPPER 30S TO MID 40S.
OVERALL EXPECT TEMPS IN THE LONG TERM PERIOD TO AVERAGE SLIGHTLY
ABOVE NORMAL WITH PRECIPITATION BELOW NORMAL.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR CONDITIONS ARE IN PLACE AT ALL TAF SITES WITH JUST SCT-BKN HIGH
LEVEL CLOUDS ACROSS THE REGION. ALTHOUGH WINDS ARE CURRENTLY RATHER
LIGHT...A SOUTHERLY BREEZE WILL INCREASE TO AROUND 10 KTS AT ALL
SITES THROUGH THE AFTERNOON HOURS.
AN APPROACHING COLD FRONT WILL BRING A BAND OF RAIN SHOWERS ACROSS
THE REGION BETWEEN 02Z-07Z TONIGHT. THE RAIN SHOULD ONLY LAST AT
ANY ONE PARTICULAR LOCATION FOR A FEW HOURS. THERE IS A SLIGHT CHC
FOR SOME RUMBLES OF THUNDER...ALTHOUGH DUE TO THE UNCERTAINTY AND
LOW PROBABILITY OF THIS OCCURRING...IT WILL NOT BE INCLUDED IN THE
TAFS AT THIS TIME. WITHIN ANY RAIN SHOWERS...VSBYS AND PERHAPS CIGS
AS WELL MAY LOWER TO MVFR RANGE. IFR CONDITIONS ARE NOT ANTICIPATED
AT THIS TIME...ALTHOUGH A BRIEF DROP TO IFR CONDITIONS CANNOT BE
TOTALLY RULED OUT...ESP IF ANY THUNDERSTORM DO DEVELOP.
WITHIN AND JUST BEHIND THE RAIN SHOWERS...THE WINDS WILL SWITCH TO
W-SW DIRECTION AND BECOME RATHER GUSTY. SOME GUSTS OF AROUND 25 KTS
ARE POSSIBLE...ESP FOR KALB/KPSF.
CLOUDS SHOULD START TO SCT OUT AFTER ABOUT 06Z-07Z...WITH VFR
CONDITIONS RETURNING...AND SKIES WILL BE CLEAR BY MID THURSDAY
MORNING. IN ADDITION...WINDS WILL DECREASE ON THURSDAY MORNING TO
AROUND 5-10 KTS AFTER SUNRISE AS HIGH PRESSURE BUILDS INTO THE
REGION...ALTHOUGH THERE STILL MAY BE A FEW LINGERING HIGHER WIND
GUSTS AT KPSF/KALB THROUGH ABOUT NOON OR SO.
OUTLOOK...
THU-MON...VFR...NO SIG WX.
&&
.FIRE WEATHER...
A COLD FRONT WILL BRING SHOWERS AND ISOLATED THUNDERSTORMS TO
EASTERN NEW YORK AND WESTERN NEW ENGLAND LATE THIS AFTERNOON INTO
THE OVERNIGHT PERIOD. HIGH PRESSURE WILL BRIEFLY BUILD IN ON
THURSDAY WITH AN UPPER LEVEL DISTURBANCE PRODUCING SOME ISOLATED
TO SCATTERED RAIN AND SNOW SHOWERS.
RH VALUES WILL LOWER TO 30 TO 40 PERCENT LATE THIS
AFTERNOON...AND THEN RISE TO 75 TO 100 PERCENT TONIGHT. THE RH VALUES
WILL DROP TO 20-30 PERCENT BY THURSDAY AFTERNOON.
THE WINDS WILL INCREASE FROM THE SOUTH AT 10 TO 20 MPH WITH SOME
GUSTS TO 30 MPH TODAY. THE WINDS WILL SHIFT TO THE SOUTHWEST OR WEST
AT 10 TO 20 MPH TONIGHT WITH SOME GUSTS IN THE 30 TO 40 MPH RANGE
WITH THE FRONTAL PASSAGE. THE WINDS WILL BE FROM THE NORTHWEST AT
10 TO 15 MPH WITH A FEW LOCATIONS HAVING GUSTS TO 25 MPH ON
THURSDAY.
A WETTING RAINFALL WILL OCCUR LATE THIS AFTERNOON INTO TONIGHT
WITH A QUARTER TO HALF AN INCH OF RAIN EXPECTED FROM THE CAPITAL
REGION...BERKSHIRES AND EASTERN CATSKILLS NORTHWARD...WITH LESS
THAN A QUARTER OF AN INCH POSSIBLE FURTHER SOUTH.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED OVER THE NEXT 5 DAYS.
THE NEXT WIDESPREAD RAINFALL IS EXPECTED LATE THIS AFTERNOON INTO
TONIGHT. THE HPC QPF HAS LOWERED A BIT WITH GENERALLY A QUARTER TO
A HALF AN INCH OF RAINFALL FROM THE CAPITAL
REGION...BERKSHIRES...AND THE EASTERN CATSKILLS NORTHWARD...WITH
LESS THAN A QUARTER INCH FOR MOST LOCATIONS TO THE SOUTH. SNOWMELT
WILL CONTINUE ACROSS THE ADIRONDACKS AND SOUTHERN GREENS ON
WEDNESDAY...DUE TO MAX TEMPS REACHING INTO THE 60S AND DEWPOINTS
GETTING INTO THE 40S. DESPITE THE SNOWMELT...WHICH IS MUCH MORE
LIMITED DUE TO THE SMALLER AREAL COVERAGE...THE EXPECTED RAINFALL
LOOKS LIGHT ENOUGH TO AVOID ANY ISOLATED HYDROLOGIC ISSUES IN
THOSE AREAS.
DRY WEATHER WILL RETURN FOR THURSDAY WITH HIGH PRESSURE IN
CONTROL. ISOLATED TO SCATTERED LIGHT RAIN OR SNOW SHOWERS MAY
RETURN FOR THURSDAY NIGHT FOR LOCATIONS NORTH OF THE MID HUDSON
VALLEY AND NW CT. RIVERS AND STREAMS WILL CONTINUE TO RECEDE WITH
DRY WEATHER EXPECTED THE NEXT SEVERAL DAYS BEYOND THURSDAY NIGHT.
FOR DETAILS ON SPECIFIC AREA RIVERS AND
LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE
ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION
SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/WASULA
NEAR TERM...FRUGIS/JPV/WASULA
SHORT TERM...WASULA
LONG TERM...11
AVIATION...FRUGIS
FIRE WEATHER...WASULA
HYDROLOGY...FRUGIS/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
124 PM EDT WED APR 24 2013
.SYNOPSIS...
A MILDER AIR MASS WILL YIELD ABOVE NORMAL TEMPERATURES
THIS AFTERNOON BEFORE A COLD FRONT ARRIVES WITH SHOWERS...AND
PERHAPS A FEW THUNDERSTORMS...IN THE EVENING. HIGH PRESSURE WILL
BRIEFLY BUILD INTO THE REGION WITH SEASONABLE TEMPERATURES FOR
THURSDAY. A STRONG UPPER LEVEL DISTURBANCE MAY BRING ISOLATED TO
SCATTERED RAIN AND SNOW SHOWERS TO PARTS OF EASTERN NEW YORK AND
WESTERN NEW ENGLAND THURSDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1040 AM EDT...WHILE MUCH OF THE REGION CURRENTLY HAS A MOSTLY
SUNNY SKY...HIGH CLOUDS ARE STARTING TO SPREAD ACROSS WESTERN PARTS OF
THE AREA LATE THIS MORNING AS A FRONTAL SYSTEM BEGINS TO APPROACH
FROM THE WEST.
A FEW RAIN SHOWERS DEVELOPED OUT WELL AHEAD OF THE COLD FRONT ACROSS
WESTERN AND CENTRAL NEW YORK...BUT OUR LOCAL HIRES WRF AND THE
3KM HRRR MODEL ALL SUGGESTED THESE WOULD START TO DIMINISH AS THEY
APPROACHED OUR AREA. RADAR TRENDS OVER THE LAST 30 MINUTES HAVE
SUGGESTED THIS LOOKS TO BE THE CASE...SO WE HAVEN/T MADE ANY MAJOR
ADJUSTMENTS TO OUR POPS ACROSS WESTERN AREAS...WITH JUST SLIGHT
CHC/LOW CHC POPS FOR THE LATE MORNING/EARLY AFTN FOR WESTERN
AREAS.
THE NAM/GFS/ECMWF/CANADIAN GUIDANCE ARE ALL IN PRETTY GOOD AGREEMENT
REGARDING THE TIMING OF THE SHOWERS ASSOCIATED WITH THE FRONT
UNTIL THE MID TO LATE PM FOR THE EXTREME NW ZONES...AND THEN
GRADUALLY SPREADING THEM EASTWARD FOR THE EARLY EVENING. THE BEST
CHC OF SHOWERS WILL BE WEST OF THE HUDSON RIVER VALLEY PRIOR TO 6
PM. A SLIGHT CHC OF THUNDERSTORMS WAS KEPT IN FROM THE MOHAWK
VALLEY SOUTHWARD DUE TO POCKETS OF ELEVATED INSTABILITY...AS THE
SHOWALTER INDICES LOWER TO 0 TO -1C. THE MID LEVEL LAPSE RATES
START TO STEEPEN IN THE H700-H500 RANGE TO 6.5-7.5C/KM...BUT LACK
OF APPRECIABLE INSTABILITY...DEEPER MOISTURE...AND FAVORABLE MID
AND UPPER LEVEL JET DYNAMICS SHOULD LIMIT THE THUNDERSTORMS THAT
DUE FORM TO NON- SEVERE LEVELS. MORE DISCUSSION ON THE CONVECTION
IN THE SHORT TERM.
THE H850 TEMPS INCREASE +9 TO +13C AHEAD OF THE FRONT. THE H850
FLOW INCREASES FORM THE S/SW TO 40-55 KTS BY NIGHTFALL. IT WILL
BECOME BREEZY IN THE PM WITH SOUTHERLY WINDS OF 10 TO 20 MPH WITH
SOME GUSTS 30-35 MPH. MAX TEMPS IN THE U60S TO L70S WILL BE COMMON
IN THE VALLEYS...AND 60S WILL BE LIKELY OVER THE MTNS WITH SFC
DEWPTS RISING INTO THE 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...THE BEST CHC FOR WIDESPREAD RAINFALL FROM THE FRONT
LOOKS TO BE IN THE 6 PM TO MIDNIGHT TIME FRAME. THERE IS DECENT
LOW-LEVEL CONVERGENCE ALONG AND IN THE WAKE OF THE COLD FRONT. THE
BETTER JET STREAK ALOFT RACES INTO QUEBEC...AS THE UNFAVORABLE
RIGHT FRONT QUAD OF A 125+ KT H250 JET STREAK MOVES OVER THE SRN
HALF OF THE FCST AREA...WHICH WILL DAMPEN THE PCPN A BIT SOUTH AND
EAST OF THE CAPITAL REGION.
THE THREAT FOR ISOLATED THUNDERSTORMS WAS KEPT IN UNTIL MIDNIGHT
FROM THE CAPITAL REGION...MOHAWK VALLEY...BERKSHIRES SOUTH. POPS
WERE INCREASED TO LIKELY AND CATEGORICAL VALUES. THE STEEPENING MID
LEVEL LAPSE RATES...AND STRENGTHENING LOW LEVEL JET ASSOCIATED
WITH THE FRONT WARRANTED PUTTING SOME WIND GUSTS TO 30 TO 40
MPH...ESPECIALLY JUST IN THE WAKE OF THE FRONT. THE PWATS DO
EXCEED AN INCH FOR A BRIEF PERIOD OF TIME /COUPLE STANDARD
DEVIATIONS ABOVE NORMAL/...BUT DROP OFF WITH THE BLAST OF COLD
ADVECTION THAT FOLLOWS THE FRONTAL PASSAGE. QPF WILL RANGE FROM A
TENTH OF AN INCH OR SO...OVER THE SOUTHEAST CORNER OF THE FCST
AREA...TO UP TO A HALF AN INCH OVER THE NW EXTREME. SOME OF THE
RESIDUAL POST FRONTAL SHOWERS OVER THE SRN DACKS MAY TRANSITION TO
SNOW SHOWERS WITH LIGHT COATINGS TO A FEW TENTHS OF AN INCH IN A
FEW SPOTS. MIN TEMPS ARE TRICKY TIMING THE COLD ADVECTION. THERE
ARE LARGE DIFFERENCE BTWN THE NAM AND GFSMOS. THE GFS IS MUCH
COLDER BY ALMOST 10 DEGREES IN SOME LOCATIONS. LEANED CLOSER TO THE
WARMER NAM MOS GUIDANCE DUE TO ITS TRACK RECORD LATELY...AND
ACTUALLY WENT CLOSE TO THE ECM MOS GUIDANCE. LOWS EXPECTED IN THE
L40S IN THE HUDSON RIVER VALLEY...BERKS...CT RIVER VALLEY AND NW
CT...MID AND U30S ELSEWHERE...EXCEPT SOME U20S TO L30S OVER THE
SRN DACKS.
THURSDAY...HIGH PRESSURE QUICKLY RIDGES IN FROM THE SOUTH AND WEST
WITH A BRIEF PERIOD OF DRY WEATHER...AS A POTENT SHORT-WAVE TROUGH
QUICKLY MOVES TOWARDS THE REGION FROM THE GREAT LAKES REGION. THIS
DAY WILL BE SEASONABLY WARM AND DRY WITH H850 TEMPS IN THE 0C TO
-4C RANGE OVER THE REGION. EXPECT U50S TO L60S IN THE
VALLEYS...AND U40S TO M50S OVER THE HIGHER TERRAIN.
THURSDAY NIGHT...TRICKY DYNAMIC SHORT-WAVE LACKING ROBUST LOW-
LEVEL MOISTURE TO WORK WITH. THE NAM HAS THE TROUGH PASS THROUGH
FAIRLY DRY. THE GFS/ECMWF CONTINUE TO PAINT LIGHT AMOUNTS OF QPF
OF A FEW HUNDREDTHS TO A TENTH OF AN INCH FROM THE ERN
CATSKILLS...CAPITAL REGION...NRN BERKS NORTHWARD. THE DIFFERENTIAL
CYCLONIC VORTICITY WILL TRIGGER SOME ISOLD-SCT RAIN AND SNOW
SHOWERS. THERE WILL LIKELY BE A QUICK SHOT OF RADIATIONAL COOLING
AHEAD OF THIS POTENT SHORT-WAVE WITH TEMPS FALLING INTO THE M20S
TO M30S ACROSS THE REGION. COATING TO HALF INCH SNOW AMOUNTS WILL
BE POSSIBLE ESPECIALLY FOR ELEVATIONS 500 FT AND GREATER...A
LITTLE WET SNOW MIGHT ALSO OCCUR AT THE VALLEY FLOOR LOCATIONS.
FRIDAY...LOW AND MID LEVEL HEIGHTS QUICKLY RISE AS THE SHORT-WAVE
TROUGH ZIPS BY NRN NEW ENGLAND BY THE PM. SFC HIGH PRESSURE BUILDS
IN FROM THE OHIO VALLEY...AND THE GREAT LAKES REGION WITH FAIR AND
DRY WX FOR THE AFTERNOON. EXPECT HIGHS IN THE L60S IN THE CAPITAL
REGION...MID HUDSON VALLEY...CNTRL AND SRN TACONICS...AND NW CT.
MID AND U50S WILL PREVAIL IN ALL OTHER LOCATIONS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
RATHER UNUSUAL TO BE FORECASTING AN ENTIRELY DRY LONG TERM
PERIOD...HOWEVER THAT IS THE CASE WITH THIS LONG TERM FORECAST.
HIGH PRESSURE WILL DOMINATE OUR WEATHER INITIALLY BUILDING AT THE
SURFACE AND THEN ALOFT AS WELL BY MONDAY AND TUESDAY. THE
STRENGTHENING HIGH PRESSURE SYSTEM WILL KEEP ANY MOISTURE WHICH
TRIES TO LIFT NORTHWARD WELL SOUTH OF OUR REGION.
EXPECT HIGHS ON SATURDAY TO BE IN THE UPPER 50S TO MID 60S WITH
HIGHS SUNDAY THROUGH TUESDAY MAINLY IN THE 60S TO AROUND 70. LOWS
FRIDAY NIGHT ARE EXPECTED TO RANGE FROM THE MID 20S TO MID 30S WITH
LOWS SATURDAY NIGHT IN THE 30S TO AROUND 40 AND LOWS SUNDAY NIGHT
AND MONDAY NIGHT IN THE UPPER 30S TO MID 40S.
OVERALL EXPECT TEMPS IN THE LONG TERM PERIOD TO AVERAGE SLIGHTLY
ABOVE NORMAL WITH PRECIPITATION BELOW NORMAL.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR CONDITIONS ARE IN PLACE AT ALL TAF SITES WITH JUST SCT-BKN HIGH
LEVEL CLOUDS ACROSS THE REGION. ALTHOUGH WINDS ARE CURRENTLY RATHER
LIGHT...A SOUTHERLY BREEZE WILL INCREASE TO AROUND 10 KTS AT ALL
SITES THROUGH THE AFTERNOON HOURS.
AN APPROACHING COLD FRONT WILL BRING A BAND OF RAIN SHOWERS ACROSS
THE REGION BETWEEN 02Z-07Z TONIGHT. THE RAIN SHOULD ONLY LAST AT
ANY ONE PARTICULAR LOCATION FOR A FEW HOURS. THERE IS A SLIGHT CHC
FOR SOME RUMBLES OF THUNDER...ALTHOUGH DUE TO THE UNCERTAINTY AND
LOW PROBABILITY OF THIS OCCURRING...IT WILL NOT BE INCLUDED IN THE
TAFS AT THIS TIME. WITHIN ANY RAIN SHOWERS...VSBYS AND PERHAPS CIGS
AS WELL MAY LOWER TO MVFR RANGE. IFR CONDITIONS ARE NOT ANTICIPATED
AT THIS TIME...ALTHOUGH A BRIEF DROP TO IFR CONDITIONS CANNOT BE
TOTALLY RULED OUT...ESP IF ANY THUNDERSTORM DO DEVELOP.
WITHIN AND JUST BEHIND THE RAIN SHOWERS...THE WINDS WILL SWITCH TO
W-SW DIRECTION AND BECOME RATHER GUSTY. SOME GUSTS OF AROUND 25 KTS
ARE POSSIBLE...ESP FOR KALB/KPSF.
CLOUDS SHOULD START TO SCT OUT AFTER ABOUT 06Z-07Z...WITH VFR
CONDITIONS RETURNING...AND SKIES WILL BE CLEAR BY MID THURSDAY
MORNING. IN ADDITION...WINDS WILL DECREASE ON THURSDAY MORNING TO
AROUND 5-10 KTS AFTER SUNRISE AS HIGH PRESSURE BUILDS INTO THE
REGION...ALTHOUGH THERE STILL MAY BE A FEW LINGERING HIGHER WIND
GUSTS AT KPSF/KALB THROUGH ABOUT NOON OR SO.
OUTLOOK...
THU-MON...VFR...NO SIG WX.
&&
.FIRE WEATHER...
A COLD FRONT WILL BRING SHOWERS AND ISOLATED THUNDERSTORMS TO
EASTERN NEW YORK AND WESTERN NEW ENGLAND LATE THIS AFTERNOON INTO
THE OVERNIGHT PERIOD. HIGH PRESSURE WILL BRIEFLY BUILD IN ON
THURSDAY WITH AN UPPER LEVEL DISTURBANCE PRODUCING SOME ISOLATED
TO SCATTERED RAIN AND SNOW SHOWERS.
RH VALUES WILL LOWER TO 30 TO 40 PERCENT LATE THIS
AFTERNOON...AND THEN RISE TO 75 TO 100 PERCENT TONIGHT. THE RH VALUES
WILL DROP TO 20-30 PERCENT BY THURSDAY AFTERNOON.
THE WINDS WILL INCREASE FROM THE SOUTH AT 10 TO 20 MPH WITH SOME
GUSTS TO 30 MPH TODAY. THE WINDS WILL SHIFT TO THE SOUTHWEST OR WEST
AT 10 TO 20 MPH TONIGHT WITH SOME GUSTS IN THE 30 TO 40 MPH RANGE
WITH THE FRONTAL PASSAGE. THE WINDS WILL BE FROM THE NORTHWEST AT
10 TO 15 MPH WITH A FEW LOCATIONS HAVING GUSTS TO 25 MPH ON
THURSDAY.
A WETTING RAINFALL WILL OCCUR LATE THIS AFTERNOON INTO TONIGHT
WITH A QUARTER TO HALF AN INCH OF RAIN EXPECTED FROM THE CAPITAL
REGION...BERKSHIRES AND EASTERN CATSKILLS NORTHWARD...WITH LESS
THAN A QUARTER OF AN INCH POSSIBLE FURTHER SOUTH.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED OVER THE NEXT 5 DAYS.
THE NEXT WIDESPREAD RAINFALL IS EXPECTED LATE THIS AFTERNOON INTO
TONIGHT. THE HPC QPF HAS LOWERED A BIT WITH GENERALLY A QUARTER TO
A HALF AN INCH OF RAINFALL FROM THE CAPITAL
REGION...BERKSHIRES...AND THE EASTERN CATSKILLS NORTHWARD...WITH
LESS THAN A QUARTER INCH FOR MOST LOCATIONS TO THE SOUTH. SNOWMELT
WILL CONTINUE ACROSS THE ADIRONDACKS AND SOUTHERN GREENS ON
WEDNESDAY...DUE TO MAX TEMPS REACHING INTO THE 60S AND DEWPOINTS
GETTING INTO THE 40S. DESPITE THE SNOWMELT...WHICH IS MUCH MORE
LIMITED DUE TO THE SMALLER AREAL COVERAGE...THE EXPECTED RAINFALL
LOOKS LIGHT ENOUGH TO AVOID ANY ISOLATED HYDROLOGIC ISSUES IN
THOSE AREAS.
DRY WEATHER WILL RETURN FOR THURSDAY WITH HIGH PRESSURE IN
CONTROL. ISOLATED TO SCATTERED LIGHT RAIN OR SNOW SHOWERS MAY
RETURN FOR THURSDAY NIGHT FOR LOCATIONS NORTH OF THE MID HUDSON
VALLEY AND NW CT. RIVERS AND STREAMS WILL CONTINUE TO RECEDE WITH
DRY WEATHER EXPECTED THE NEXT SEVERAL DAYS BEYOND THURSDAY NIGHT.
FOR DETAILS ON SPECIFIC AREA RIVERS AND
LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE
ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION
SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/WASULA
NEAR TERM...FRUGIS/WASULA
SHORT TERM...WASULA
LONG TERM...11
AVIATION...FRUGIS
FIRE WEATHER...WASULA
HYDROLOGY...FRUGIS/WASULA
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1240 PM CDT WED APR 24 2013
.DISCUSSION...
ISSUED 954 AM CDT WED APR 24 2013
SATELLITE IMAGERY SHOWING THE BACK EDGE OF THE CLOUDS STARTING TO
APPROACH THE ILLINOIS RIVER. LATEST GUIDANCE FROM THE RAP SHOWS A
BIT OF SLOWING DOWN OF THE CLEARING THROUGH MIDDAY...WITH THE
EASTERN CWA STILL HAVING A FAIR AMOUNT OF CLOUDINESS INTO EARLY
AFTERNOON. THE LINGERING RAIN AND SNOW SHOWERS IN THE EASTERN CWA
STILL ON TRACK TO EXIT THE AREA OVER THE NEXT COUPLE HOURS.
FORECAST IS GENERALLY ON TRACK. HAVE SENT SOME MINOR GRID UPDATES TO
REFRESH THE CURRENT TRENDS...BUT WILL HOLD OFF A BIT LONGER ON
UPDATING THE ZONE FORECASTS UNTIL THE PRECIP HAS EXITED THE AREA.
GEELHART
&&
.AVIATION...
ISSUED 1239 PM CDT WED APR 24 2013
MVFR CONDITIONS HAVE NOW PUSHED EAST OF ALL CENTRAL ILLINOIS TAF
SITES...BUT EXTENSIVE DIURNAL CUMULUS DEVELOPMENT WILL KEEP
CEILINGS AROUND 4000 FEET THROUGH THE AFTERNOON. A FAST MOVING
FRONTAL BOUNDARY WILL PASS TO THE NORTH OVERNIGHT. MAY SEE A FEW
SHOWERS COME CLOSE TO KPIA/KBMI LATE TONIGHT...BUT CONFIDENCE IS
NOT HIGH ENOUGH TO INCLUDE IN THE TAFS AT THIS POINT. BEHIND THE
FRONT...MORE DIURNAL DEVELOPMENT IS EXPECTED THURSDAY MORNING...
WITH SOUNDINGS CURRENTLY INDICATING CEILINGS STAYING JUST ABOVE
THE MVFR RANGE.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT WED APR 24 2013
00Z MODELS ARE IN FAIR AGREEMENT NEXT FEW DAYS AND WILL USE A
BLEND. MET AND MAV GUIDANCE TEMPS SIMILAR THROUGH FRIDAY AND
STAYED CLOSE TO.
SHORT TERM...TODAY THROUGH SATURDAY
WIDESPREAD BAND OF SHOWERS AND ISOLATED THUNDERSTORMS WAS SE OF A
DANVILLE TO SHELBYVILLE LINE EARLY THIS MORNING WITH PERIODS OF
MODERATE TO HEAVY RAIN SHOWERS AT TIMES. CUMBERLAND AND EFFINGHAM
COUNTIES HAVE AN URBAN AND SMALL STREAM FLOOD ADVISORY UNTIL 10 AM.
SHOWERS WILL GRADUALLY DIMINISH OVER SE IL DURING THIS MORNING AND
COULD STILL SEE A FEW SNOWFLAKES INTO MID MORNING ON NW EDGE OF
THIS PRECIPITATION. TEMPS CURRENTLY IN THE UPPER 30S OVER CENTRAL
IL AND 40-45F IN SE IL WITH BLUSTERY NNW WINDS 10-20 MPH. 1007 MB
LOW PRESSURE WAS DEEPENING OVER NW OHIO WITH ITS COLD FRONT INTO
NW KY/TN. 1028 MB HIGH PRESSURE WAS OVER NORTH TEXAS AND WESTERN
OK INTO SE CO. SLOWED DOWN THE CLEARING OF LOW CLOUDS TODAY AS A
STRONG SHORT WAVE OVER THE CENTRAL PLAINS MOVES EAST INTO IL BY
18Z TODAY THEN EXITS QUICKLY NE OF IL DURING THE AFTERNOON WHEN
LOW CLOUDS WILL DECREASE. HIGHS IN THE LOWER 50S WITH SOME UPPER
40S OVER EAST CENTRAL IL.
WEAK LOW PRESSURE AROUND 1015 MB MOVES INTO THE NORTHERN GREAT
LAKES BY DAWN THU AND BRINGS A WEAK COLD FRONT INTO CENTRAL IL
WHILE ANOTHER FAIRLY STRONG SHORT WAVE/TROF DIGS INTO LAKE MI.
THIS TO KEEP BRUNT OF MIXED LIGHT PRECIPITATION NORTH OF CENTRAL
IL WITH JUST SLIGHT CHANCES BETWEEN 10 PM AND 4 AM NORTH OF PEORIA.
LOWS IN THE MID TO UPPER 30S AGAIN TONIGHT. 1027 MB HIGH PRESSURE
BUILDS INTO THE MID MS VALLEY BY SUNSET THU BRINGING MORE SUNSHINE
AND HIGHS IN THE MID TO UPPER 50S. LOWS THU NIGHT IN THE UPPER 30S
TO NEAR 40F WITH COOLEST READINGS IN EAST CENTRAL IL WHERE MID 30S
POSSIBLE.
WEATHER SYSTEM EJECTS EAST FROM THE SOUTHERN PLAINS INTO THE TN
VALLEY FRI/SAT AND KEEPS THE BRUNT OF ITS SHOWERS SOUTH OF CENTRAL
IL. GFS HAS TRENDED FURTHER SOUTH WITH THE QPF FIELDS AND MORE
CONFIDENCE OF A DRY FORECAST ON FRIDAY WITH HIGHS IN THE LOWER 60S.
HAVE 20-30% CHANCE OF SHOWERS FROM I-70 SOUTH FRIDAY NIGHT AND SAT
WITH HIGHEST POPS IN SE IL WITH THUNDER CHANCES STAYING SOUTH OF I-64.
HIGHS SAT IN THE MID 60S.
LONG TERM...SATURDAY NIGHT THROUGH TUESDAY NIGHT
GENERALLY DRY AND MILDER WEATHER EXPECTED SUNDAY AND MONDAY AS
SYSTEM EXITS EAST OF IL SUNDAY...WITH HIGHS AROUND 70F SUNDAY
AND MID 70S MONDAY. GFS BRINGS PATCHES OF LIGHT QPF INTO IL SUNDAY
BUT THINK THIS WILL BE MORE TO OUR SE AS UPPER LEVEL RIDGE
BUILDING INTO IL. AN UPPER LEVEL TROF DIGGING INTO THE NORTHERN
PLAINS TUE TO PUSH A FRONTAL BOUNDARY SE INTO IA TUE WITH GFS
QUICKER WITH COLD FRONT THAN ECMWF. WILL GO WITH ALLBLEND SLIGHT
CHANCE POPS OF SHOWERS AND THUNDERSTORMS TUE AND TUE NIGHT. STILL
IN THE 70S FOR HIGHS TUE WITH CENTRAL/SE IL AHEAD OF THE COLD
FRONT.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
419 PM CDT WED APR 24 2013
.SHORT TERM.../TONIGHT /...
ISSUED AT 419 PM CDT WED APR 24 2013
FORECAST CONCERN FOR LATE AFTERNOON AND TONIGHT WILL REVOLVE AROUND
PRECIPITATION CHANCES. APPROACHING COLD FRONT WITH STRONG PV
ANOMALY...CURRENTLY LEADING TO PRECIPITATION IN SOUTH DAKOTA...WILL
SPREAD SE INTO IOWA THIS EVENING. SYSTEM WILL BE QUICK MOVING...AND
ANTICIPATE BAND OF SHOWERS TO SWEEP QUICKLY ACROSS THE
AREA...SIMILAR TO HRRR TIMING/TREND. WITH SKIES REMAINING CLEAR
ACROSS CENTRAL IOWA...NO CU FIELD NOTED...AND HIGH DEW POINT
DEPRESSIONS...DO NOT ANTICIPATE DEVELOPMENT AHEAD OF LINE.
HOWEVER...SOME MU CAPE WILL LEAD TO ISOLATED THUNDER NEAR FRONT.
PRECIPITATION ENDS QUICKLY BEHIND FROPA WITH SUBSIDENCE. HAVE KEPT
TEMPERATURES COOLER ACROSS THE NORTH ESPECIALLY...DROPPING OFF
QUICKLY BEHIND FROPA...MAY SEE SOME LIGHT RN/SN MIX ACROSS THE NORTH
AFTER MIDNIGHT WITH ANY LINGERING PRECIPITATION.
.LONG TERM.../THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 419 PM CDT WED APR 24 2013
A FAIRLY QUIET...AND MUCH...MUCH WARMER WEATHER PATTERN IS SETTING
UP ACROSS THE MIDWEST FOR THE NEXT COUPLE OF DAYS. UNDER THE
INFLUENCE OF HIGH PRESSURE...THURSDAY AFTERNOON LOOKS TO BE VERY
SIMILAR TO WEDNESDAY...JUST A FEW DEGREES WARMER AND A FEW MORE
CLOUDS.
HEADING INTO FRIDAY...A NOTABLE THERMAL RIDGE WILL BEGIN TO BUILD
ALL THE WAY UP OVER THE DAKOTAS AND INTO CANADA. 850MB TEMPERATURES
LOOK TO MAKE IT UP TO AROUND 8C...SETTING UP THE POTENTIAL FOR SOME
OF THE WARMEST TEMPERATURES THUS FAR OF 2013 TO BE ADVECTED INTO THE
CWA...WHEN THE THERMAL RIDGE SHIFTS EASTWARD BEGINNING SATURDAY.
STICKING TO FRIDAY...A WEAK SURFACE TROUGH WILL PUSH THROUGH THE
MIDWEST. THE GFS AND NAM BOTH HINT AT CAPE VALUES MAKING IT TO
AROUND 300 J/KG...BUT WINDS ALOFT ARE QUITE WEAK...AND THE BOUNDARY
ITSELF IS FAIRLY WEAK...SO NOT MUCH PRESENT IN TERMS OF FOCUSING
MECHANISMS TO GENERATE ANY CONFIDENCE IN THUNDERSTORM DEVELOPMENT.
SATURDAY AND SUNDAY...BOTH DAYS SHOULD BE SIMILAR WEATHER WISE AS
THE AFOREMENTIONED THERMAL RIDGE SHIFTS EASTWARD. 850 MB TEMPS WILL
GO FROM AROUND 8C IN CENTRAL IOWA...TO AROUND 10C ON SATURDAY...TO
AROUND 14C ON SUNDAY. LOTS OF DRY AIR ALOFT WILL SUPPORT MAINLY
SUNNY SKIES ON BOTH SATURDAY AND SUNDAY.
THE WEATHER PATTERN CHANGES AS WE HEAD INTO MONDAY AND TUESDAY. WE
WILL BE WATCHING FOR THE POTENTIAL FOR AFTERNOON THUNDERSTORMS ON
BOTH DAYS. AS OF NOW...TUESDAY LOOKS LIKE THE BETTER OF THE TWO DAYS
FOR THUNDERSTORM DEVELOPMENT. AS A SIZABLE AREA OF LOW PRESSURE SETS
UP TO MOVE THROUGH THE DAKOTAS...MONDAY FEATURES A WARM FRONT
PASSING THROUGH IOWA TOWARDS WISCONSIN. THERE IS SOME INSTABILITY
EXPECTED AS WE WILL CERTAINLY BE UNDER THE WAA ADVECTION OF THE
THERMAL RIDGE...BUT AS OF NOW...IT APPEARS THE CAP WILL BE DIFFICULT
TO BREAK. FOR TUESDAY INTO WEDNESDAY...A COLD FRONT IS PROGGED TO
PASS THROUGH IOWA. THE GFS SEEMS TO BE A BIT FAST VERSUS THE REST OF
THE MODELS...SO ARE TRENDING THE PASSING OF THE FROPA BACK INTO
WEDNESDAY.
&&
.AVIATION...24/18Z
ISSUED AT 1145 AM CDT WED APR 24 2013
CEILINGS WILL REMAIN PRIMARILY VFR THROUGH PERIOD...THOUGH
APPROACHING LOW PRESSURE TROUGH WILL BRING INCREASING CLOUDS.
THROUGHOUT THE AFTERNOON WILL SEE GOOD MIXING AND STRONG AND GUSTY
WINDS...WINDS WILL REMAIN STRONG THROUGH PERIOD. WILL SEE
PRECIPITATION CHANCES ACROSS NORTHERN SITES...KFOD/KMCW/KALO WITH
THROUGH. HAVE PUSHED BACK ONSET OF PRECIPITATION A BIT. IN
ADDITION...COULD SEE MVFR CEILINGS OR LOWER AT TIMES WITH -RA.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...AWB
LONG TERM...KOTENBERG
AVIATION...AWB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
347 PM MDT WED APR 24 2013
.UPDATE...
ISSUED AT 340 PM MDT WED APR 24 2013
SURFACE OBSERVATIONS INDICATE A NARROW CORRIDOR OF LOWER DEW
POINTS FROM AROUND IMPERIAL SOUTHEAST TO HILL CITY. WITH NORTHWEST
WINDS GUSTING TO 30 MPH AS THE SURFACE TROUGH MOVES THROUGH AND
RELATIVE HUMIDITIES FALLING TO AROUND 15 PERCENT...AM THINKING THERE WILL
BE BRIEF PERIODS OF CRITICAL FIRE WEATHER CONDITIONS THIS
AFTERNOON. BEHIND THE SURFACE TROUGH OVER SOUTHWEST NEBRASKA
TEMPERATURES APPEAR TO BE COOLING SOME. THE INCREASING CLOUD
COVER MAY ALSO HELP THE WIND GUSTS TO DECREASE BELOW 30 MPH. WITH
ALL THIS IN MIND AND THAT CRITICAL FIRE WEATHER CONDITIONS ARE
JUST BEING REALIZED AT MID AFTERNOON...AM NOT CONFIDENT ENOUGH TO
ISSUE A FIRE WEATHER HIGHLITE FOR THE NORTHEAST PART OF THE AREA.
HOWEVER...SINCE THIS AREA DID NOT RECEIVE MUCH SNOW FROM THE
RECENT STORM...THE FUELS MAY BE DRY ENOUGH FOR CRITICAL FIRE
WEATHER CONDITIONS SO HAVE ISSUED AN SPS MENTIONING THE BRIEF
THREAT.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY)
ISSUED AT 101 PM MDT WED APR 24 2013
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW BROAD TROUGH
CENTERED OVER GREAT LAKES REGION WITH W/NW FLOW ACROSS THE NORTHERN
AND CENTRAL PLAINS. A SHORTWAVE TROUGH IS CURRENTLY OVER EASTERN
WYOMING EXTENDING ACROSS THE GREAT BASIN.
THIS THIS FEATURE IS PROGGED TO SPLIT WITH THE MAIN ENERGY ALOFT
REMAINING NORTH OF OUR CWA. VERY STEEP LOW LEVEL LAPSE RATES AND
WEAK FORCING AHEAD OF THIS FEATURE HAVE PRODUCED HIGH BASED
VIRGA/LIGHT SHOWERS OVER PARTS OF NORTH CENTRAL NEBRASKA WITH A CU
FIELD EXTENDING SOUTH WHERE FURTHER DEVELOPMENT IS POSSIBLE. WHILE
I COULDNT RULE OUT A FEW SPRINKLES OR VIRGA THIS AFTERNOON/EARLY
EVENING CONFIDENCE IS LOW IN MEASURABLE.
SUBSIDENCE SHOULD OVERSPREAD THE REGION OVERNIGHT...WITH CLEARING
SKIES AND LIGHT AND VARIABLE WINDS. LEE TROUGH BUILDING OVER SE
COLORADO AND WESTERLY FLOW ALOFT WILL SUPPORT MODERATING AIR MASS
OVER OUR CWA BEGINNING TONIGHT. OVERNIGHT LOWS (WHILE BELOW NORMAL)
SHOULD BE WARMER THAN THE LAST FEW NIGHTS WITH VALUES IN THE UPPER
20S/LOW 30S (COLDEST IN PROXIMITY TO LINGERING SNOW PACK). TEMPS
ALOFT CONTINUE TO MODERATE THROUGH THE DAY THURSDAY. ITS HARD TO SAY
IF WE WILL STILL HAVE ANY EFFECT FROM SNOW PACK OR NOT (WHAT IS LEFT
AFTER MELTING THIS AFTERNOON). FOR NOW I STAYED IN LINE WITH
PREVIOUS FORECASTS WITH HIGHS IN THE LOW 60S WHERE SNOW PACK IS AND
UPPER 60S/LOW 70S ELSEWHERE.
A SHORTWAVE TROUGH IS PROGGED TO MOVE INTO THE SOUTHERN ROCKIES
THURSDAY AFTERNOON...WITH CLOUDS INCREASING FROM THE WEST/SOUTHWEST.
A FEW HIGH BASED SHOWERS/ISOLATED THUNDERSTORMS MAY DEVELOP OVER THE
HIGHER TERRAIN OF COLORADO...WHICH COULD SNEAK INTO WESTERN PORTIONS
OF OUR CWA DURING THE LATE AFTERNOON HOURS. CONFIDENCE IS GENERALLY
LOW ON MEASURABLE...HOWEVER WITH STEEP LAPSE RATES AND NAM/SREF
SHOWING LIGHT QPF I ADDED SLIGHT CHANCE POPS TO WESTERN KIT
CARSON/CHEYENNE COUNTIES IN COLORADO IN THE 21-00Z TIME FRAME.
OTHER CONCERN FOR THURSDAY AFTERNOON WILL BE WINDY CONDITIONS WITH
TIGHT UNIDIRECTIONAL GRADIENT OUT OF THE S/SW TO ABOUT H7. THERE
IS SOME SUPPORT OF NEAR ADVISORY CRITERIA DURING THE AFTERNOON
HOURS...HOWEVER DUE TO LOW CONFIDENCE IN DURATION...AND MARGINAL
CONDITIONS I DECIDED AGAINST ISSUANCE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 115 PM MDT WED APR 24 2013
THURSDAY NIGHT-SATURDAY...UPPER LOW FORECAST TO BE OVER NORTHEAST
ARIZONA AROUND 00Z FRIDAY EXPECTED TO MOVE EAST/NORTHEAST INTO
SOUTHEAST COLORADO BY 12Z FRIDAY THEN SOUTHEAST KANSAS BY 06Z
SATURDAY AND EASTERN ILLINOIS AT 00Z SUNDAY. SHOWERS AND A FEW
THUNDERSTORMS ARE POSSIBLE AS THIS SYSTEM MOVES ACROSS OUR PART OF
THE COUNTRY THURSDAY NIGHT...OTHERWISE DRY THROUGH THE PERIOD.
SATURDAY NIGHT-MONDAY...DRY WITH LITTLE IN THE WAY OF CLOUDINESS.
ABOVE NORMAL TEMPERATURES WITH LOWS IN THE 40S SATURDAY NIGHT
WARMING INTO THE LOW 40S WEST TO LOW 50S EAST SUNDAY NIGHT. HIGHS
SUNDAY MID 70S TO AROUND 80 WEST...LOW 80S EAST. A TAD COOLER MONDAY
WITH MID 70S TO AROUND 80 ACROSS THE AREA...COOLEST WEST. PAST 5
DAYS OF 850 TEMPERATURES WOULD SUPPORT SLIGHTLY WARMER READINGS THEN
CURRENTLY ADVERTISED.
MONDAY NIGHT-WEDNESDAY...PRECIPITATION CHANCES INCREASE A BIT AS AN
UPPER TROUGH AND COLD FRONT MOVE ACROSS THE AREA. HIGH TEMPERATURES
TUESDAY UPPER 60S TO LOW 70S WITH 55-60 WEDNESDAY. LOWS MONDAY NIGHT
MID 40S TO MID 50S (WEST TO EAST)...LOW TO MID 40S (WEST TO EAST)
TUESDAY NIGHT. MAY SEE SOME BREEZY NORTH TO NORTHEAST WINDS
TUESDAY NIGHT THROUGH WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1121 AM MDT WED APR 24 2013
VFR CONDITIONS EXPECTED THROUGH TAF PERIOD AT BOTH KGLD AND KMCK
TERMINALS. NW WINDS GUSTING TO 25KT ARE EXPECTED AT BOTH TERMINALS
THIS AFTERNOON AS A DISTURBANCE MOVES ACROSS CENTRAL NEBRASKA.
THESE WINDS SHOULD DIMINISH AROUND SUNSET WITH LIGHT AND VARIABLE
WINDS OVERNIGHT. A SURFACE TROUGH WILL DEEPEN OVER SE COLORADO
THURSDAY WITH GRADIENT INCREASING OVER BOTH TERMINALS. RESULT
SHOULD BE A SHIFT AND INCREASE IN WINDS TO THE SOUTH-SOUTHWEST
AROUND SUNRISE...WITH GUSTS AROUND 25KT AT KGLD BY MID MORNING.
STRONGER WINDS ARE LIKELY THURSDAY AFTERNOON AT BOTH
TERMINALS...WHICH IS OUTSIDE THE CURRENT TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...99
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
120 PM MDT WED APR 24 2013
.SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY)
ISSUED AT 101 PM MDT WED APR 24 2013
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW BROAD TROUGH
CENTERED OVER GREAT LAKES REGION WITH W/NW FLOW ACROSS THE NORTHERN
AND CENTRAL PLAINS. A SHORTWAVE TROUGH IS CURRENTLY OVER EASTERN
WYOMING EXTENDING ACROSS THE GREAT BASIN.
THIS THIS FEATURE IS PROGGED TO SPLIT WITH THE MAIN ENERGY ALOFT
REMAINING NORTH OF OUR CWA. VERY STEEP LOW LEVEL LAPSE RATES AND
WEAK FORCING AHEAD OF THIS FEATURE HAVE PRODUCED HIGH BASED
VIRGA/LIGHT SHOWERS OVER PARTS OF NORTH CENTRAL NEBRASKA WITH A CU
FIELD EXTENDING SOUTH WHERE FURTHER DEVELOPMENT IS POSSIBLE. WHILE
I COULDNT RULE OUT A FEW SPRINKLES OR VIRGA THIS AFTERNOON/EARLY
EVENING CONFIDENCE IS LOW IN MEASURABLE.
SUBSIDENCE SHOULD OVERSPREAD THE REGION OVERNIGHT...WITH CLEARING
SKIES AND LIGHT AND VARIABLE WINDS. LEE TROUGH BUILDING OVER SE
COLORADO AND WESTERLY FLOW ALOFT WILL SUPPORT MODERATING AIRMASS
OVER OUR CWA BEGINNING TONIGHT. OVERNIGHT LOWS (WHILE BELOW NORMAL)
SHOULD BE WARMER THAN THE LAST FEW NIGHTS WITH VALUES IN THE UPPER
20S/LOW 30S (COLDEST IN PROXIMITY TO LINGERING SNOW PACK). TEMPS
ALOFT CONTINUE TO MODERATE THROUGH THE DAY THURSDAY. ITS HARD TO SAY
IF WE WILL STILL HAVE ANY EFFECT FROM SNOW PACK OR NOT (WHAT IS LEFT
AFTER MELTING THIS AFTERNOON). FOR NOW I STAYED IN LINE WITH
PREVIOUS FORECASTS WITH HIGHS IN THE LOW 60S WHERE SNOW PACK IS AND
UPPER 60S/LOW 70S ELSEWHERE.
A SHORTWAVE TROUGH IS PROGGED TO MOVE INTO THE SOUTHERN ROCKIES
THURSDAY AFTERNOON...WITH CLOUDS INCREASING FROM THE WEST/SOUTHWEST.
A FEW HIGH BASED SHOWERS/ISOLATED THUNDERSTORMS MAY DEVELOP OVER THE
HIGHER TERRAIN OF COLORADO...WHICH COULD SNEAK INTO WESTERN PORTIONS
OF OUR CWA DURING THE LATE AFTERNOON HOURS. CONFIDENCE IS GENERALLY
LOW ON MEASURABLE...HOWEVER WITH STEEP LAPSE RATES AND NAM/SREF
SHOWING LIGHT QPF I ADDED SLIGHT CHANCE POPS TO WESTERN KIT
CARSON/CHEYENNE COUNTIES IN COLORADO IN THE 21-00Z TIME FRAME.
OTHER CONCERN FOR THURSDAY AFTERNOON WILL BE WINDY CONDITIONS WITH
TIGHT UNIDIRECTIONAL GRADIENT OUT OF THE S/SW TO ABOUT H7. THERE
IS SOME SUPPORT OF NEAR ADVISORY CRITERIA DURING THE AFTERNOON
HOURS...HOWEVER DUE TO LOW CONFIDENCE IN DURATION...AND MARGINAL
CONDITIONS I DECIDED AGAINST ISSUANCE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 115 PM MDT WED APR 24 2013
THURSDAY NIGHT-SATURDAY...UPPER LOW FORECAST TO BE OVER NORTHEAST
ARIZONA AROUND 00Z FRIDAY EXPECTED TO MOVE EAST/NORTHEAST INTO
SOUTHEAST COLORADO BY 12Z FRIDAY THEN SOUTHEAST KANSAS BY 06Z
SATURDAY AND EASTERN ILLINOIS AT 00Z SUNDAY. SHOWERS AND A FEW
THUNDERSTORMS ARE POSSIBLE AS THIS SYSTEM MOVES ACROSS OUR PART OF
THE COUNTRY THURSDAY NIGHT...OTHERWISE DRY THROUGH THE PERIOD.
SATURDAY NIGHT-MONDAY...DRY WITH LITTLE IN THE WAY OF CLOUDINESS.
ABOVE NORMAL TEMPERATURES WITH LOWS IN THE 40S SATURDAY NIGHT
WARMING INTO THE LOW 40S WEST TO LOW 50S EAST SUNDAY NIGHT. HIGHS
SUNDAY MID 70S TO AROUND 80 WEST...LOW 80S EAST. A TAD COOLER MONDAY
WITH MID 70S TO AROUND 80 ACROSS THE AREA...COOLEST WEST. PAST 5
DAYS OF 850 TEMPERATURES WOULD SUPPORT SLIGHTLY WARMER READINGS THEN
CURRENTLY ADVERTISED.
MONDAY NIGHT-WEDNESDAY...PRECIPITATION CHANCES INCREASE A BIT AS AN
UPPER TROUGH AND COLD FRONT MOVE ACROSS THE AREA. HIGH TEMPERATURES
TUESDAY UPPER 60S TO LOW 70S WITH 55-60 WEDNESDAY. LOWS MONDAY NIGHT
MID 40S TO MID 50S (WEST TO EAST)...LOW TO MID 40S (WEST TO EAST)
TUESDAY NIGHT. MAY SEE SOME BREEZY NORTH TO NORTHEAST WINDS
TUESDAY NIGHT THROUGH WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1121 AM MDT WED APR 24 2013
VFR CONDITIONS EXPECTED THROUGH TAF PERIOD AT BOTH KGLD AND KMCK
TERMINALS. NW WINDS GUSTING TO 25KT ARE EXPECTED AT BOTH TERMINALS
THIS AFTERNOON AS A DISTURBANCE MOVES ACROSS CENTRAL NEBRASKA.
THESE WINDS SHOULD DIMINISH AROUND SUNSET WITH LIGHT AND VARIABLE
WINDS OVERNIGHT. A SURFACE TROUGH WILL DEEPEN OVER SE COLORADO
THURSDAY WITH GRADIENT INCREASING OVER BOTH TERMINALS. RESULT
SHOULD BE A SHIFT AND INCREASE IN WINDS TO THE SOUTH-SOUTHWEST
AROUND SUNRISE...WITH GUSTS AROUND 25KT AT KGLD BY MID MORNING.
STRONGER WINDS ARE LIKELY THURSDAY AFTERNOON AT BOTH
TERMINALS...WHICH IS OUTSIDE THE CURRENT TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...99
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
101 PM MDT WED APR 24 2013
.SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY)
ISSUED AT 101 PM MDT WED APR 24 2013
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW BROAD TROUGH
CENTERED OVER GREAT LAKES REGION WITH W/NW FLOW ACROSS THE NORTHERN
AND CENTRAL PLAINS. A SHORTWAVE TROUGH IS CURRENTLY OVER EASTERN
WYOMING EXTENDING ACROSS THE GREAT BASIN.
THIS THIS FEATURE IS PROGGED TO SPLIT WITH THE MAIN ENERGY ALOFT
REMAINING NORTH OF OUR CWA. VERY STEEP LOW LEVEL LAPSE RATES AND
WEAK FORCING AHEAD OF THIS FEATURE HAVE PRODUCED HIGH BASED
VIRGA/LIGHT SHOWERS OVER PARTS OF NORTH CENTRAL NEBRASKA WITH A CU
FIELD EXTENDING SOUTH WHERE FURTHER DEVELOPMENT IS POSSIBLE. WHILE
I COULDNT RULE OUT A FEW SPRINKLES OR VIRGA THIS AFTERNOON/EARLY
EVENING CONFIDENCE IS LOW IN MEASURABLE.
SUBSIDENCE SHOULD OVERSPREAD THE REGION OVERNIGHT...WITH CLEARING
SKIES AND LIGHT AND VARIABLE WINDS. LEE TROUGH BUILDING OVER SE
COLORADO AND WESTERLY FLOW ALOFT WILL SUPPORT MODERATING AIRMASS
OVER OUR CWA BEGINNING TONIGHT. OVERNIGHT LOWS (WHILE BELOW NORMAL)
SHOULD BE WARMER THAN THE LAST FEW NIGHTS WITH VALUES IN THE UPPER
20S/LOW 30S (COLDEST IN PROXIMITY TO LINGERING SNOW PACK). TEMPS
ALOFT CONTINUE TO MODERATE THROUGH THE DAY THURSDAY. ITS HARD TO SAY
IF WE WILL STILL HAVE ANY EFFECT FROM SNOW PACK OR NOT (WHAT IS LEFT
AFTER MELTING THIS AFTERNOON). FOR NOW I STAYED IN LINE WITH
PREVIOUS FORECASTS WITH HIGHS IN THE LOW 60S WHERE SNOW PACK IS AND
UPPER 60S/LOW 70S ELSEWHERE.
A SHORTWAVE TROUGH IS PROGGED TO MOVE INTO THE SOUTHERN ROCKIES
THURSDAY AFTERNOON...WITH CLOUDS INCREASING FROM THE WEST/SOUTHWEST.
A FEW HIGH BASED SHOWERS/ISOLATED THUNDERSTORMS MAY DEVELOP OVER THE
HIGHER TERRAIN OF COLORADO...WHICH COULD SNEAK INTO WESTERN PORTIONS
OF OUR CWA DURING THE LATE AFTERNOON HOURS. CONFIDENCE IS GENERALLY
LOW ON MEASURABLE...HOWEVER WITH STEEP LAPSE RATES AND NAM/SREF
SHOWING LIGHT QPF I ADDED SLIGHT CHANCE POPS TO WESTERN KIT
CARSON/CHEYENNE COUNTIES IN COLORADO IN THE 21-00Z TIME FRAME.
OTHER CONCERN FOR THURSDAY AFTERNOON WILL BE WINDY CONDITIONS WITH
TIGHT UNIDIRECTIONAL GRADIENT OUT OF THE S/SW TO ABOUT H7. THERE
IS SOME SUPPORT OF NEAR ADVISORY CRITERIA DURING THE AFTERNOON
HOURS...HOWEVER DUE TO LOW CONFIDENCE IN DURATION...AND MARGINAL
CONDITIONS I DECIDED AGAINST ISSUANCE.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 235 AM MDT WED APR 24 2013
DRY CONDITIONS AND ABOVE NORMAL TEMPERATURES ARE EXPECTED THIS
WEEKEND AS WEAK UPPER LEVEL RIDGING BUILDS INTO THE AREA. A TROUGH
OVER THE PACIFIC NORTHWEST WILL PROGRESS EASTWARD BY THE FIRST OF
THE WEEK BUT SIGNIFICANT DIFFERENCES EMERGE AMONG GFS ENSEMBLE
MEMBERS AND ECMWF BY THEN. DEPENDING ON WHAT HAPPENS WITH THE
AFOREMENTIONED TROUGH...ADJUSTMENT IN POP AND WEATHER GRIDS MAY BE
NEEDED. GFS IS MORE PROGRESSIVE THAN ECMWF. FOR NOW...DECIDED TO
CARRY SLIGHT CHANCE POPS MAINLY IN THE EASTERN HALF OF THE FORECAST
AREA ON MONDAY AND TUESDAY WHERE BETTER LOW LEVEL MOISTURE WILL
RESIDE. MADE ONLY MINOR ADJUSTMENTS TO CR INIT POP GRIDS TO SHARPEN
THE GRADIENT SLIGHTLY FROM WEST TO EAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1121 AM MDT WED APR 24 2013
VFR CONDITIONS EXPECTED THROUGH TAF PERIOD AT BOTH KGLD AND KMCK
TERMINALS. NW WINDS GUSTING TO 25KT ARE EXPECTED AT BOTH TERMINALS
THIS AFTERNOON AS A DISTURBANCE MOVES ACROSS CENTRAL NEBRASKA.
THESE WINDS SHOULD DIMINISH AROUND SUNSET WITH LIGHT AND VARIABLE
WINDS OVERNIGHT. A SURFACE TROUGH WILL DEEPEN OVER SE COLORADO
THURSDAY WITH GRADIENT INCREASING OVER BOTH TERMINALS. RESULT
SHOULD BE A SHIFT AND INCREASE IN WINDS TO THE SOUTH-SOUTHWEST
AROUND SUNRISE...WITH GUSTS AROUND 25KT AT KGLD BY MID MORNING.
STRONGER WINDS ARE LIKELY THURSDAY AFTERNOON AT BOTH
TERMINALS...WHICH IS OUTSIDE THE CURRENT TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BRB
AVIATION...DR
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
106 PM EDT WED APR 24 2013
.AVIATION...
//DISCUSSION...
LOW MVFR/HIGH IFR CONDITIONS WILL CONTINUE TO ACCOMPANY WIDESPREAD
RAIN AND SNOW SHOWERS FOR THE REMAINDER OF THE AFTERNOON,
PARTICULARLY FOR KFNT AND POINTS SOUTH, AS A WAVE LIFTS INTO
SOUTHEAST MICHIGAN. ALTHOUGH LITTLE TO NO ACCUMULATION IS FORECAST,
VISIBILITY WITHIN REGIONS OF HEAVIER SNOWFALL WILL FALL TO AS LOW AS
1SM. RAIN WILL BECOME INCREASINGLY FAVORED OVER SNOW AS THE
AFTERNOON WEARS ON GIVEN GRADUAL DIURNAL HEATING OF THE BOUNDARY
LAYER ALONG WITH DECLINING PRECIPITATION INTENSITY. WITH THE EXIT OF
DEEPER MOISTURE TO THE EAST BY THIS EVENING, PRECIPITATION WILL
TRANSITION TO DRIZZLE AND EVENTUALLY COME TO AN END BY AROUND 21Z
WITH GRADUAL IMPROVEMENT TO ALL MVFR WITH VFR CONDITIONS BUILDING IN
FOR THE OVERNIGHT PERIOD. WESTERLY WINDS WILL PERSIST THROUGH LATE
EVENING BEFORE A SURFACE RIDGE AXIS TRANSITS THE AREA AND FORCES
WINDS TO TURN SOUTHERLY PRIOR TO DAYBREAK ON THURSDAY. CONDITIONS
WILL ONCE AGAIN DETERIORATE TO MVFR AS ANOTHER ROUND OF SHOWERS
APPROACHES FOR THURSDAY MORNING.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FEET THROUGH LATE AFTERNOON
* HIGH CONFIDENCE IN MIXED RAIN AND SNOW PTYPE
&&
.PREV DISCUSSION...ISSUED 350 AM EDT WED APR 24 2013
SHORT TERM...TODAY AND TONIGHT
BY FORECAST ISSUANCE TIME...WEAK SFC LOW PRESSURE AND A COLD FRONT
WILL BE PUSHING EAST OF METRO DETROIT AND PORT HURON. THERE HAS BEEN
A FAIRLY WIDESPREAD AREA OF RAINFALL ACROSS SE MI ALONG AND BEHIND
THE SFC FRONT LAST NIGHT WITHIN A REGION OF STRONG LOWER
TROPOSPHERIC FRONTOGENESIS. THE HEAVIER AND MORE PERSISTENT RAINFALL
HAS OCCURRED WITHIN THE 800-700MB LAYER OF THE FRONTAL SLOPE. THIS
TARGETED THE TRI CITIES AND SAGINAW BAY REGION WHERE RADAR
ESTIMATED RAINFALL IS ALREADY AROUND AN INCH. THE REGION OF HIGHER
INTENSITY RAINFALL IS EXPECTED TO SHIFT INTO THE THUMB REGION DURING
THE EARLY MORNING HOURS. GIVEN THE ESTIMATED RAINFALL AND WITH THE
EXPECTATION FOR HIGHER INTENSITY RAINFALL TO PUSH INTO THE
THUMB...THE FLOOD WATCH WILL BE CONTINUED THROUGH DAYBREAK. THERE
HAVE BEEN A FEW AWOS SITES WHICH HAVE REPORTED SNOW OVERNIGHT...
WHICH IS INCORRECT. ALL PRECIP THUS FAR HAS BEEN IN THE FORM OF
RAIN. THE NAM AND GFS SOLUTIONS APPEAR TOO COOL IN THE BOUNDARY
LAYER THIS MORNING IN COMPARISON TO OBSERVATIONS...WITH THE RAP
SOUNDINGS APPEARING TO HAVE A BETTER HANDLE ON THE LOW LEVEL THERMAL
PROFILES. THE RAP IS SUGGESTIVE OF PRECIP REMAINING MOSTLY RAIN THIS
MORNING...EXPECT ACROSS THE TRI CITIES AND THUMB WHERE COLDER AIR
CONTINUES TO FILTER IN FROM THE NW AND IS LIKELY TO CAUSE A MIX OR
BRIEF CHANGE OVER TO SNOW.
THE LOW TO MID LEVEL FGEN RESPONSE WILL WEAKEN TOWARD DAYBREAK
THROUGH LATE MORNING DUE TO THE LOW LEVEL THERMAL GRADIENT RELAXING
AS SFC LOW PRESSURE AND BETTER UPPER DYNAMICS SHIFT OFF TO THE
NORTHEAST. THIS WILL LEAD TO A STEADY DECREASE IN COVERAGE AND
INTENSITY OF THE RAINFALL. HOWEVER...THE UPPER LEVEL WAVE NOTED OVER
KANSAS IS FORECAST TO RAPIDLY LIFT ACROSS THE NRN OH VALLEY AND ERN
GREAT LAKES THIS AFTERNOON. MODEL SOLUTIONS HAVE TRENDED TOWARD A
DEEPER UPPER WAVE/STRONGER UPPER LEVEL POTENTIAL VORTICITY ADVECTION
WITH THIS FEATURE AND APPEAR WELL INITIALIZED. AS IT LIFTS NE THIS
AFTERNOON...SOME WEAK MID LEVEL DEFORMATION WILL OVERSPREAD SE MI...
ESPECIALLY THE EASTERN HALF OF THE FORECAST AREA. AN INTENSIFICATION
OF AN UPPER JET STREAK WILL OCCUR ACROSS LOWER MI AND LAKE HURON AS
WELL...WITH INCREASING DIVERGENCE OVERSPREADING OHIO...LAKE ERIE AND
FAR EASTERN PORTIONS OF SE MI. THIS FORCING WILL INTERACT WITH THE
BACK EDGE OF THE DEEPER MOISTURE PLUME OVER SE MI...SUGGESTING
RAINFALL WILL INCREASE IN COVERAGE AGAIN DURING THE AFTERNOON. THE
RATHER MARGINAL FORCING SUGGEST ADDITIONAL DAYTIME RAINFALL AMOUNTS
WILL GENERALLY REMAIN BELOW A QUARTER INCH. THE EXPECTATION FOR
ENOUGH DAYTIME WARMING IN THE BOUNDARY LAYER SUPPORTS PRECIP TYPE AS
ALL RAIN TODAY. ALTHOUGH WITH 850MB TEMPS FORECAST TO DROP TO
-5C...THERE WAS SOME SERIES CONTEMPLATION OVER ADDING A MENTION OF
SOME SNOW NORTH OF METRO DETROIT.
THE EXTENT OF CLOUDS AND RAIN TODAY...WITH DWPTS DROPPING INTO THE
LOW 30S...WILL SUPPRESS TEMPS TO THE MID 30S TO LOWER 40S WELL INTO
THE AFTERNOON. A PUSH OF DRIER AIR LATE IN THE AFTERNOON AND EVENING
WILL END THE RAIN AND CAUSE SOME PARTIAL CLEARING WHICH SHOULD ALLOW
A LATE DAY SPIKE IN TEMPS INTO THE MID-UPPER 40S. PARTIAL CLEARING
TONIGHT AMIDST SHORT WAVE RIDGING WILL ALLOW ENOUGH OPPORTUNITY FOR
NIGHTTIME COOLING TO DROP TEMPS WELL DOWN INTO THE 30S.
LONG TERM...THURSDAY THROUGH TUESDAY
STRONG UPPER WAVE OVER SASKATCHEWAN WILL DIVE DOWN INTO THE WESTERN
GREAT LAKES BY THURSDAY MORNING...AS IT ROTATES WITHIN THE LONGWAVE
TROUGH OVER THE CENTRAL U.S. AND CANADA. THIS WAVE WILL CLIP QUICKLY
ACROSS LOWER MICHIGAN AND INTO ONTARIO THURSDAY...PUSHING A WEAK LOW
PRESSURE SYSTEM ACROSS THE NORTHERN GREAT LAKES AND DRAGGING A COLD
FRONT ACROSS THE AREA. FRONTAL TIMING CONTINUES TO VARY WITHIN THE
MODELS...AND STRONG PREFERENCE GOES TO THE VERY CONSISTENT EURO
MODEL. GOOD BURST OF LIFT WILL ACCOMPANY THE COLD FRONT...WITH
FRONTAL DYNAMICS STACKED UNDERNEATH MID-LEVEL PVA AND LEFT EXIT
REGION FORCING. COLD AIR ALOFT REMAINING IN PLACE BEHIND TODAY`S
SYSTEM IN COMBINATION WITH H500 TEMPS DROPPING TO ABOUT -35C WITH
THE UPPER WAVE...WHICH HAS ARCTIC ORIGINS...WILL CREATE VERY
MODERATELY STEEP LOW AND MID-LEVEL LAPSE RATES (FROM SURFACE UP
THROUGH 400MB). DEEP LAYER OF INSTABILITY WILL HELP MAXIMIZE
RESPONSE FROM FORCING AND MAKE THE BEST OF ONLY MEAGER MOISTURE
(SHALLOW LAYER OF MOISTURE POOLING AHEAD OF FRONT WITH SPECIFIC
HUMIDITY 3 G/KG AND PW OVERALL ONLY AROUND 0.4 INCHES).
PRECIPITATION ASSOCIATED WITH THE FRONT WILL AFFECT THE AREA DURING
THE FIRST HALF OF THURSDAY...WITH ADDITIONAL SHOWERS POSSIBLY
REDEVELOPING DURING THE LATE AFTERNOON AS LAPSE RATES FURTHER
STEEPEN AND SOME MOISTURE LINGERS. PRECIPITATION TYPE IS STILL A
LITTLE UNCERTAIN WITH GFS/NAM FORECAST SOUNDINGS STILL HINTING THAT
SNOW MAY BE POSSIBLE...BUT GIVEN WARMER EURO PROFILES IN THE PAST
TWO MODEL RUNS...WILL KEEP PRECIP TYPE AS RAIN. WOULD ALSO EXPECT TO
SEE SOME GRAUPEL FALL AS SHOWERS WILL HAVE A CONVECTIVE ELEMENT TO
THEM AND FREEZING LEVELS WILL BE VERY LOW.
SURFACE HIGH PRESSURE WILL EXPAND INTO THE AREA FROM THE OHIO VALLEY
THURSDAY NIGHT AND FRIDAY BRINGING DRY WEATHER BACK TO THE AREA. LOW
PRESSURE TRACKING ACROSS HUDSON BAY WILL DRAW SOME WARMER AIR UP
INTO THE REGION ON FRIDAY...ALLOWING TEMPERATURES TO CREEP BACK UP
INTO THE UPPER 50S.
WEEKEND WILL BE MARKED BY ZONAL FLOW...WITH UPPER RIDGING BUILDING
INTO THE GREAT LAKES MONDAY AND TUESDAY IN RESPONSE TO TROUGHING
DROPPING DOWN INTO THE NORTHERN ROCKIES. WILL SEE A WARMING TREND
DURING THIS STRETCH...WITH MAX TEMPERATURES GRADUALLY WARMING TO
AROUND 70. MODELS HAVE BEEN TRYING TO GENERATE CONVECTION JUST ABOUT
EVERY AFTERNOON AS LAPSE RATES STEEPEN DURING THE DAY. GIVEN GENERAL
LACK OF GOOD MOISTURE ADVECTION (HAVE A FEELING SURFACE TD`S ARE TOO
HIGH AS WELL) AND EVENTUAL CAPPING FROM THE RIDGE...ELECTED TO KEEP
THE FORECAST DRY AND THUNDERSTORM FREE FOR NOW.
MARINE...
NORTHWEST WINDS IN THE WAKE OF LAST NIGHTS COLD FRONTAL PASSAGE HAS
USHERED IN COLDER AIR...LEADING TO UNSTABLE CONDITIONS OVER THE
LAKES. SOME GUSTS UP TO 25 KNOTS ARE EXPECTED OVER THE OPEN WATERS
OF LAKE HURON. THESE CONDITIONS SHOULD BE SHORT LIVED AS HIGH
PRESSURE BUILDS IN FROM THE WEST LATE THIS AFTERNOON AND ALLOWS
WINDS AND WAVES TO RELAX. A FAST MOVING LOW PRESSURE SYSTEM WILL
THEN TRAVERSE THE REGION ON THURSDAY. THE GRADIENT WILL NOT BE TOO
TERRIBLE STRONG...BUT COULD LEAD TO SOME GUSTS UP TO 25 KNOTS OVER
LAKES ST CLAIR...ERIE AND THE SOUTHERN BASIN OF LAKE HURON.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT
HURON...UNTIL 5 PM WEDNESDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....JVC
SHORT TERM...SC
LONG TERM....HLO
MARINE.......SC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
153 PM EDT WED APR 24 2013
.SYNOPSIS...
SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL OCCUR LATE TODAY AND
INTO THIS EVENING AS A STRONG COLD FRONT PASSES THROUGH THE AREA.
BEHIND THIS FEATURE...DRY CONDITIONS ARE EXPECTED ON THURSDAY WITH
THE NEXT ROUND OF SHOWERS POSSIBLE THURSDAY NIGHT AND EARLY FRIDAY
AS ANOTHER WEAK WAVE WILL PASSES OVERHEAD. FAIR AND PLEASANT
CONDITIONS ARE THEN EXPECTED FOR THE WEEKEND AS STRONG HIGH
PRESSURE BUILDS INTO THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
1115 AM UPDATE...
A WEAK WARM FRONT MOVING THROUGH THE REGION THIS MORNING HAS
PRODUCED A FAIR AMOUNT OF CLOUD COVER ALONG WITH SPRINKLES OVER
CENTRAL NEW YORK AND THE NORTHERN TIER OF PA. IT HAS ALSO KEPT
SFC TEMPS LOWER THAN EXPECTED WITH MAXES NOW RANGING FROM THE
MID/UPPER 60S. COLD FRONT HAS JUST CROSSED CLEVELAND WITH
WIDESPREAD SHOWERS JUST AHEAD AND MAINLY BEHIND BOUNDARY. LATEST
MODEL GUIDANCE CONTINUES TO SHOW SEVERAL HUNDRED J/KG OF CAPE
LATER THIS AFTERNOON PRIMARILY ACROSS THE SOUTHERN TIER OF NYS AND
NE PA. WITH THE AMOUNT OF CLOUD COVER IT WILL BE INTERESTING TO SEE
IF THIS MUCH CAPE IS REALIZED. MODEL SOUNDINGS DO SHOW PRETTY GOOD
MID LEVEL LAPSE RATES SO IF ENOUGH FRONTAL LIFT IS GENERATED THIS
INSTABILITY COULD BE TAPPED. IF ENOUGH INSTABILITY IS REALIZED
THE CURRENT WIND FIELD AND SHEAR VALUES WOULD SUPPORT A FEW
STRONGER CELLS WITH THE POTENTIAL FOR A FEW SEVERE THUNDERSTORMS.
CURRENT FORECAST IN GOOD SHAPE WILL CONTINUE WITH CATEGORICAL POPS
FOR SHOWERS DURING FROPA AND CHC POPS FOR THUNDERSTORMS.
630 AM UPDATE...
QUICK UPDATE TO ACCOUNT FOR LATEST RADAR TRENDS TO OUR WEST.
REGIONAL RADARS NOW SHOWING AN INITIAL BAND OF LGT RAIN SHWRS
WORKING INTO WESTERN NY THIS HR...WHICH APPEARS TO BE THE RESULT
OF WEAK ISENTROPIC ASCENT ALONG/NORTH OF DIFFUSE WARM FRONT. THAT
SAID...HAVE UPDATED GRIDS TO BRING IN RAIN A FEW HRS EARLIER
ACROSS THE WESTERN AND NORTHERN ZONES. NO OTHER CHANGES NEEDED AT
THE PRESENT TIME.
PREVIOUS NEAR TERM DISCUSSION...
A CHALLENGING FCST TO SAY THE LEAST TODAY AS A STRONG COLD FRONT
WILL PLOW THROUGH THE REGION DURING THE LATE AFTERNOON AND EARLY
EVENING HRS. THE MAIN DIFFICULTIES ARE TWOFOLD WITH THE FIRST
BEING THE DEGREE OF WARMING PROCEEDING THE FRONT...AND THE SECOND
CONCERNING SEVERE WX POTENTIAL AS THE FRONT BARRELS THROUGH THE
REGION. FIRST THINGS FIRST HOWEVER AND WE SHOULD PROBABLY START
WITH A GENERAL SYNOPTIC OVERVIEW.
EARLY MORNING WATER VAPOR CLEARLY SHOWING A DEEP TROUGH OF LOW
PRESSURE DIGGING ACROSS THE SOUTHERN PLAINS THIS MORNING WITH
BROAD CYCLONIC FLOW PREVAILING OVER THE NATION/S MIDSECTION.
ACROSS OUR REGION...WEAK UPPER RIDGING THAT BROUGHT SUCH NICE
WX TO OUR AREA YESTERDAY NOW DEPARTING TO OUR EAST AS UPPER TROUGH
AND ASSOCIATED DEFORMATION AXIS WITH THE WESTERN ATLANTIC COASTAL
LOW WORK OFF THE NEW ENGLAND COAST. WITH TIME TODAY...COLD FRONT
ASSOCIATED WITH THE CENTRAL US TROUGH WILL ADVANCE EAST OVER OUR
REGION BY THIS AFTERNOON BRINGING WITH IT A PERIOD OF SHWRS AND
STORMS TO MUCH OF OUR AREA.
AS FOR THE SEVERE WX POTENTIAL...MODELS REMAIN ALL OVER THE PLACE
WITH RESPECT TO THE DEGREE OF DESTABILIZATION THAT WILL OCCUR
PRIOR TO FROPA LATER TODAY. THE NAM REMAINS THE MOST UNSTABLE
SOLUTION THIS MORNING WITH AWIPS PLAN VIEW MAPS SHOWING A NARROW
CORRIDOR OF MLCAPE VALUES RANGING FROM 400-500 J/KG IMMEDIATELY
PROCEEDING THE FRONT MAINLY WEST OF THE I-81 CORRIDOR. THIS IS
PERPLEXING TO SOME DEGREE AS CORRESPONDING NAM BUFKIT SOUNDINGS
FOR ELM AND OTHER WESTERN FCST POINT LOCATIONS ADVERTISE MUCH
LOWER VALUES. THE GFS SEEMS TO AGREE WITH THE WEAKER NAM BUFKIT
SOLUTIONS...AS DOES THE LATEST RUC AND LOCALLY RUN WRF MODELS. AS
FOR THE KINEMATICS...WIND FIELDS ALOFT REMAIN IMPRESSIVELY STRONG
WITH 0-6 KM BULK SHEAR VECTORS RANGING FROM 40 TO 50 KTS ACROSS
THE REGION WHILE 0-3 KM BULK SHEAR VALUES ARE JUST AS HIGH. THIS
SUGGESTS THAT IF SEVERE WX WERE TO DEVELOP...DAMAGING WIND GUSTS
WOULD BE THE BIGGEST THREATS IF ANY DEVELOPING CONVECTION WERE TO
MORPH INTO A WELL-DEFINED SQUALL LINE OR SHORT BOWING SEGMENTS. THIS
AGREES WELL WITH LOCAL SEVERE WX CHECKLIST WHICH SUGGEST A
SIGNIFICANT COOL SEASON WIND EVENT IS POSSIBLE HOWEVER ITS HARD TO
GET BY LATEST MODEL TRENDS OF VERY MODEST DESTABILIZATION.
CONSIDERING THE AMOUNT OF CLOUD COVER THAT WILL LIKELY BEGIN
MOVING OVERHEAD THIS MORNING COUPLED WITH THE FACT THAT RETURN
FLOW MOISTURE WILL BE MEAGER AT BEST (AFTERNOON DEWPOINT TEMPS
ONLY CLIMBING INTO THE MIDDLE TO UPPER 40S)...WE/RE INCLINED TO
BELIEVE THAT SEVERE WX POTENTIAL WILL BE FAIRLY LIMITED. THIS
AGREES WELL WITH THE LATEST SPC DAY 1 OUTLOOK WHICH ONLY
ADVERTISES GENERAL THUNDER MENTION ACROSS OUR REGION ("SEE TEXT" TO
OUR SOUTHWEST). ALTHOUGH WE TOTALLY CANNOT RULE OUT SEVERE WX
LATER TODAY...WE DO NOT THINK THAT THE FCST REGION WILL BE DEALING
WITH A WIDESPREAD SEVERE WX EVENT AT THIS TIME.
NOW TO THE NEXT ISSUE...THE HIGH TEMP FCST FOR TODAY. UPSTREAM OBS
FROM THE UPPER OHIO VLY SHOW TEMPS IN THE LOWER 60S AS CLOSE AS
CLEVELAND EARLY THIS MORNING. CONSIDERING THIS AIR WILL TRAVEL
EAST OVER OUR REGION...WE/RE INCLINED TO BELIEVE TEMPS WILL WARM
INTO THE UPPER 60S TO LOWER 70S AHEAD OF THE FRONT TODAY. ONLY
ITEM OF CONCERN IS THE LATEST SATELLITE TRENDS WHICH SHOW ENHANCED
CLOUD COVER APPROACHING FROM NORTHERN OHIO THIS MORNING. DESPITE
THIS HOWEVER...DEGREE OF THERMAL ADVECTION WILL LIKELY BE ENOUGH
TO OVERCOME LIMITED COOLING ASSOCIATED WITH INCREASING CLOUDS
ALOFT.
BY TONIGHT...COLD FRONT TO EXIT OFF TO THE EAST WITH TIME BETWEEN
00 AND 06Z. RAIN SHOULD GRADUALLY COME TO AN END WITH TIME WITH
STRONG COLD AIR ADVECTION EXPECTED IN ITS WAKE. AS A
RESULT...TEMPS WILL DROP INTO THE LOWER TO MIDDLE 30S ACROSS MUCH
OF THE REGION WITH GUSTY WINDS EXPECTED THROUGH A GOOD PORTION OF
THE OVERNIGHT HRS.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
COOLER TEMPS EXPECTED BOTH THU AND FRI AS COOL HIGH PRESSURE
BUILDS IN FOLLOWING FROPA LATER TONIGHT. WITH H85 TEMPS QUICKLY
FALLING TO NEAR ZERO CELSIUS...HIGH TEMPS ON THU ONLY LOOK TO
WARM INTO THE LOWER TO MIDDLE 50S AT BEST. SLIGHTLY WARMER TEMPS
EXPECTED ON FRI AS HIGH PRESSURE ADVANCES TO THE EAST WITH UPPER
50S TO LOWER 60S AGAIN POSSIBLE. WEAK UPPER WAVE WILL PASS ACROSS
THE REGION THU NGT/EARLY FRI BRINGING THE NEXT ROUND OF SHWRS TO
THE AREA.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
200 PM UPDATE...
NO BIG CHANGES TO THE EXTENDED. A LARGE AREA OF HIGH PRESSURE
ANCHORED TO OUR SOUTHEAST WILL PROVIDE US WITH A WARM PERIOD WITH
MAINLY DRY WEATHER. POTENTIAL FLY IN THE OINTMENT REMAINS A
NORTH/SOUTH AXIS OF MOISTURE NEAR OR JUST WEST OF OUR AREA. THE
GFS CONTINUES TO BE THE MOST AGGRESSIVE WITH THIS MOISTURE WHILE
THE EURO HINTS AT IT BUT IS MUCH DRIER. WILL MAINTAIN CONSISTENCY AND
LEAVE THE FORECAST DRY. BASED ON THE LOCATION OF THE HIGH IT DOES
APPEAR MOISTURE IN THE RETURN FLOW AROUND THE HIGH WOULD STAY TO OUR
SOUTHWEST.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR CONDS NEXT FEW HOURS AHD OF A COLD FNT APRCHG THE AREA FROM WEST.
FNT WILL BRING SHWRS AND ISLTD TRW STARTING ARND 21Z AND CONTG
THRU ARND 01Z. MVFR CIGS AND VSBYS WITH THE SHWRS...ALONG WITH
GUSTY WINDS. BHD THE FNT...CAA WILL BRING MVFR CIGS ALONG WITH
SPOTTY MVFR VSBYS IN SHWRS ESPECIALLY NY TERMINALS. DRIER AIR WELL BHD THE
FNT WILL RETURN SOME LOCATIONS TO VFR BEFORE THE END OF THE TAF
PD AND THIS WILL ESPECIALLY TRUE ACROSS THE SOUTHERN TERMINALS BY
06Z BUT NOT UNTIL CLOSER TO 12Z UP NORTH. VFR ON THURSDAY.
SOUTHWEST WINDS 10 KTS WITH GUSTS TO 25 THROUGH 0Z. WINDS VEERING
INTO THE WEST AND NORTHWEST THIS EVENING. GUSTS TO 25 KTS STILL
POSSIBLE THROUGH EARLY EVENING THEN NORTHWEST WINDS 5 TO 10 KTS
THROUGH THURSDAY.
OUTLOOK...
THU THRU MON...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG/RRM
NEAR TERM...CMG/RRM
SHORT TERM...CMG
LONG TERM...HEDEN
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
407 PM EDT WED APR 24 2013
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION TONIGHT. THE
HIGH WILL MOVE EAST ON THURSDAY AS A WEAK COLD FRONT MOVES ACROSS
THE AREA. THIS FRONT WILL BE FOLLOWED BY ANOTHER HIGH PRESSURE
SYSTEM THURSDAY NIGHT INTO FRIDAY. TEMPERATURES WILL REMAIN BELOW
NORMAL THROUGH THE PERIOD.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
MODELS WERE IN FAIRLY DECENT AGREEMENT. HAVE USED A BLEND OF THE
GFS...NAM AND RAP FOR THE NEAR TERM FORECAST.
COLD FRONT WAS EAST OF THE FORECAST AREA THIS AFTERNOON. CLOUDS
CONTINUE TO LINGER AS WELL AS A FEW SHOWERS ACRS THE NRN ZONES. A
RIDGE OF HIGH PRESSURE TO OUR WEST IS EXPECTED TO BUILD EAST INTO
THE REGION TONIGHT. THIS WILL ALLOW SKIES TO CLEAR FROM WEST TO
EAST AS WELL AS ALLOW WINDS TO DIMINISH. THERE IS CONCERN FOR
FROST AND/OR FREEZING TEMPERATURES OVERNIGHT. CONCERNING FROST
FORMATION...THE BEST CHANCES WILL BE IN THE EASTERN/SOUTHERN ZONES
WHERE WINDS WILL BE THE LIGHTEST THE LONGEST AND SHOULD NOT BE
AFFECTED BY A LATE INCREASE IN WIND FROM THE WEST AS A WEAK COLD
FRONT APPROACHES. THE FAR NW HAS THE LEAST POTENTIAL FOR FROST DUE
TO THE INCREASING PRESSURE GRADIENT LATE AS THE HIGH DEPARTS TO
THE EAST AND AFOREMENTIONED WEAK COLD FRONT APPROACHES. HOWEVER...
THERE COULD BE A SHORT WINDOW FOR FROST FORMATION...ESPECIALLY IN
LOW LYING...SHELTERED LOCATIONS SO HAVE INCLUDED FROST HERE AS
WELL. AS FOR FROST AND FREEZING TEMPERATURES...IT LOOKS LIKE A
GOOD PORTION OF CENTRAL OHIO WILL HAVE THE HIGHEST THREAT OF
REACHING FREEZING OR FALLING SLIGHTLY BELOW. IN SUMMARY...A
FREEZING WARNING HAS BEEN POSTED FOR MUCH OF CENTRAL OHIO
(INCLUDING HARDIN COUNTY) WHILE A FROST ADVISORY HAS BEEN ISSUED
ELSEWHERE. GIVEN RECENT RAINFALL...THERE COULD BE SOME FOG
DEVELOPMENT IN THE ERN/SRN LOCATIONS OVERNIGHT...BUT CONFIDENCE IN
POTENTIAL PUBLIC IMPACT IS LOW AT THIS POINT AND HAVE LEFT OUT
ATTM. OVERNIGHT LOWS WILL GENERALLY BE IN THE LOWER TO MID 30S
WITH A FEW UPPER 20S POSSIBLE ACROSS PARTS OF CENTRAL OHIO.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
RIDGE OF HIGH PRESSURE WILL MOVE EAST ON THURSDAY AS WEAK LOW
PRESSURE AND A COLD FRONT MOVE ACROSS THE GREAT LAKES AND OHIO
VALLEY. DEEPEST MOISTURE AND BEST LIFT ARE EXPECTED OVER THE NRN
ZONES AND HAVE CARRIED A CHANCE OF SHOWERS MAINLY ALONG AND NORTH
OF I-70. ELSEWHERE...SKIES WILL BE PARTLY SUNNY. TEMPERATURES WILL
BE TRICKY GIVEN SOME AFTERNOON CAA BEHIND THE FRONT AND CLOUD
DEVELOPMENT. WILL RANGE HIGHS FROM THE LOWER 50S NORTHWEST TO THE
LOWER 60S ALONG AND SOUTH OF THE OHIO RIVER.
WEAK WEATHER SYSTEM WILL PUSH EAST BY THURSDAY NIGHT...ALLOWING
ANOTHER AREA OF HIGH PRESSURE TO BUILD INTO THE REGION. SKIES WILL
CLEAR AND WINDS WILL DIMINISH. IT LOOKS LIKE A FAVORABLE NIGHT FOR
FROST FORMATION SO HAVE INCLUDED THIS WORDING IN THE FORECAST AND
HAVE MADE A MENTION OF IT IN THE HWO PRODUCT. OVERNIGHT LOWS WILL
BE IN THE LOWER TO MID 30S.
FOR FRIDAY INTO FRIDAY NIGHT...HIGH PRESSURE WILL CONTINUE TO
INFLUENCE THE REGION. RETURN SFC FLOW IS THE BEST ACROSS THE WEST
AND WEAKEST ELSEWHERE. ALSO...DESPITE SUNSHINE...850 MB TEMPS
APPEAR TO WARM UP MORE SLOWLY. AS A RESULT...HAVE GONE COOLER THAN
MOS GUIDANCE AS IT APPEARS TO BE WARMING THINGS UP A LITTLE TOO
MUCH. SOME CLOUDS WILL INCREASE LATER FRIDAY INTO FRIDAY NIGHT
FROM A MID LVL TROUGH TO OUR WEST...OTHERWISE DRY CONDITIONS ARE
EXPECTED.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
SURFACE HIGH PRESSURE WILL BE DEPARTING THE CWA AT THE START OF THE
EXTENDED FORECAST PERIOD. MODEL AGREEMENT IS RELATIVELY POOR IN
HANDLING THE EVOLUTION OF A SLOW-MOVING MID-LEVEL TROUGH OVER THE
WEEKEND. EVEN AT 72HR ON THE 12Z GFSE...THERE IS SIGNIFICANT SPREAD
BETWEEN THE ENSEMBLE MEMBERS ON THE STRENGTH AND PLACEMENT OF THE
TROUGH. THE OPERATIONAL GFS SEEMS TO BE STRONGER WITH THE TROUGH
THAN MOST OF ITS MEMBERS...WHILE THE OPERATIONAL 12Z ECMWF IS A BIT
CLOSER TO THE GFSE MEAN.
LEANING TOWARD THE SLIGHTLY WEAKER SOLUTION WOULD PROVIDE LESS IN
THE WAY OF PRECIPITATION THAN THE OPERATIONAL GFS INDICATES.
THUS...THE FORECAST WILL START DRY...AND POPS WILL GENERALLY BE HELD
IN THE 20-40 CATEGORY AND NO HIGHER (THOUGH IT WILL BE WETTER
FURTHER SOUTH IN THE TENNESSEE VALLEY). THE HIGHEST POPS WERE
ROUGHLY TIMED TO THE DIURNAL CYCLE.
BY MONDAY...THE AXIS OF THE TROUGH WILL BE MOVING EAST OF THE
REGION...AS A BIG CHANGE TO THE WEATHER PATTERN BEGINS. THERE IS
SOME DEGREE OF AGREEMENT REGARDING THE LARGE-SCALE EVOLUTION NEXT
WEEK...WITH SIGNS OF HIGHLY-AMPLIFIED HIGH PRESSURE DEVELOPING FROM
THE DEEP SOUTH THROUGH THE OHIO VALLEY AND INTO ONTARIO. IN
FACT...BY THE VERY END OF THE EXTENDED FORECAST (AND INTO LATE WEEK)
BOTH 12Z OPERATIONAL RUNS (GFS/ECMWF) AND THE 00Z ECMWF SHOW A
FULL-OUT OMEGA BLOCK DEVELOPING (TROUGH IN THE CENTRAL PLAINS /
RIDGE THROUGH THE EASTERN STATES / TROUGH OVER THE ATLANTIC). WITH
THIS AGREEMENT...THE 12Z CMC (WHICH DEVELOPS A CLOSED LOW OVER THE
DEEP SOUTH ON TUESDAY) WAS NOT USED FOR THE FORECAST.
THROUGH THE FIRST PART OF THE WEEK...DIURNALLY-DRIVEN POPS WERE
MAINTAINED (THOUGH GRADUALLY DECREASING EACH DAY AS THE RIDGE
BUILDS). SIGNIFICANT PRECIPITATION APPEARS TO REMAIN WEST OF THE ILN
CWA THROUGH AT LEAST WEDNESDAY. TEMPERATURES APPEAR TO SLOWLY RISE
THROUGH THIS PERIOD AS WELL...WITH NO SIGNIFICANT DIFFERENCES
OBSERVED IN THE RECENT MODEL RUNS (AND ONLY SMALL CHANGES MADE TO
THE GOING FORECAST). WITH THE ILN CWA LOOKING TO BE ON THE WEST SIDE
OF THE BUILDING RIDGE (AND ASSOCIATED SURFACE HIGH)...SUCH A PATTERN
WILL FAVOR SOUTHERLY FLOW.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
CDFNT HAS PUSHED E OF THE TAFS...WITH MVFR AND IFR CONDITIONS
AFFECTING THE TAFS AT THE BEGINNING OF THE PERIOD. POST FRONTAL
PCPN SHOULD END FROM W TO E OVER THE NEXT FEW HOURS...WITH VSBYS
IMPROVING...BUT CIGS ARE EXPECTED TO STAY MVFR THROUGH ABOUT
00Z...WHEN THE BACK EDGE OF THE CLOUDS ARE FORECAST TO REACH THE
WRN TAFS. THE CLOUDS SHOULD THEN CLEAR FROM W TO E BETWEEN 00Z-
04Z.
CLEAR SKIES AND WEAKENING WINDS SHOULD COMBINE TO ALLOW SOME MVFR
FOG DEVELOPMENT TOWARDS SUNRISE 10-12Z THURSDAY.
AFTER 12Z...CLOUDS AHEAD OF ANOTHER...BUT WEAKER CDFNT WILL SWING
INTO THE REGION. RIGHT NOW THEY LOOK LIKE THEY WILL STAY VFR. SOME
MODELS ARE TRYING TO DROP SOME LIGHT PCPN INTO THE NRN TAFS...BUT
AT THIS TIME THINK THE CHC IS TOO LOW TO MENTION IN THE TAFS.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...FROST ADVISORY FROM 2 AM TO 9 AM EDT THURSDAY FOR OHZ034-035-
042>044-051>053-060>063-070>073-077>082-088.
FREEZE WARNING FROM 2 AM TO 9 AM EDT THURSDAY FOR OHZ026-045-
046-054>056-064-065-074.
KY...FROST ADVISORY FROM 2 AM TO 9 AM EDT THURSDAY FOR KYZ089>100.
IN...FROST ADVISORY FROM 2 AM TO 9 AM EDT THURSDAY FOR INZ050-058-
059-066-073>075-080.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...HATZOS
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
141 PM EDT WED APR 24 2013
.SYNOPSIS...
A COLD FRONT WILL SLOWLY CROSS THE WESTERN CAROLINAS AND NORTHEAST
GEORGIA TONIGHT. MILD HIGH PRESSURE WILL THEN BUILD IN BEHIND THE
FRONT FOR THURSDAY AND FRIDAY. A SLOW MOVING AREA OF LOW PRESSURE
WILL DEVELOP OVER THE SOUTHERN PLAINS FRIDAY NIGHT AND DRIFT
NORTHEASTWARD THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH THURSDAY/...
AT 125 PM...MAIN ADJUSTMENT IS TO LOWER MAX TEMPS SEVERAL DEGREES
DUE TO CLOUD COVER. POP TRENDS ARE STILL ON TARGET AS THE FRONTAL
BAND OF PRECIP IS NOW OVER EASTERN TN AND WILL ENTER NC BORDER
COUNTIES BY 19Z. THERE HAS BEEN A NOTICABLE DECREASE IN LIGHTNING
ACTIVITY AND HAVE LOWERED PROB OF THUNDER TO JUST CHANCE IN THE
MOUNTAINS.
PREVIOUS DISCUSSION:
AT 1040 EDT...STRATUS FIELD OVER THE UPSTATE AND SOUTHERN NC
PIEDMONT SHRINKING AND ADVECTING TO THE N. IT SHOULD BE GONE BY
MIDDAY. HOWEVER...CLOUDS IN ADVANCE OF THE COLD FRONT TO THE WEST
OVER ERN TN ENCROACHING QUICKLY FROM THE W. CURRENT SKY GRID
HANDLES THIS WELL. 12Z NAM SILL SUPPORTS BRINGING NUMEROUS
SHOWERS/TSTORMS INTO THE TN BORDER COUNTIES BY MID AFTERNOON.
HOWEVER...IT CONTINUES THE PREVIOUS FORECAST TRENDS THAT WEAKENS AND
SCATTERS OUT THE CONVECTION AS IT MOVES OUT OF THE MOUNTAINS LATE
THIS AFTERNOON INTO THIS EVENING. HAVE MAINTAINED THE CHANCE OF THUNDER
OVER THE WESTERN HALF OF THE AREA INTO THIS EVENING...BUT THUNDER
CHANCES QUICKLY DIMINISH AFTER 00Z.
1130 UTC UPDATE...ONLY CHANGES WERE A FEW TWEAKS TO THE AVIATION
GRIDS FOR THE 12Z TAFS. SKY GRIDS LOOK TO BE ROUGHLY IN LINE WITH
CURRENT SAT/OBS.
AS OF 515 AM...THE SKY GRIDS WERE UPDATED TO REFLECT ENCROACHING LOW
STRATUS FROM THE SOUTH. THE 08Z RAP SEEMS TO BE INITIALIZING THE
CLOUDS FAIRLY WELL AND SO IT WAS USED TO REFLECT TRENDS IN THE
CLOUDS THRU MID MORNING. BASICALLY...IT LOOKS LIKE THE CLOUDS WILL
REACH ROUGHLY TO I-85 AROUND OR SHORTLY AFTER DAYBREAK...EXTENDING
NE TOWARD THE TRIAD. FROM THERE IT SHUD DISSIPATE AS INSOLATION
MIXES THE INVERSION/SHALLOW MOISTURE OUT BY MIDDAY.
MEANWHILE...STRATUS DECK (AROUND 5000 FT) CONTINUES TO WORK INTO THE
SW NC MTNS AND NE GA FROM THE WEST. OVERALL...STILL EXPECTING SOME
SUNSHINE BEFORE THICKER CLOUDS FINALLY OVERTAKE THE SKIES BY
MID/LATE AFTN AS A COLD FRONT WORKS INTO THE AREA. NO OTHER CHANGES
WERE MADE.
AS OF 300 AM...A COLD FRONT WAS ANALYZED CROSSING OHIO VALLEY...WITH
CONVECTION INCREASING IN COVERAGE ALONG AND AHEAD OF THE BNDRY.
MODELS ARE IN GOOD AGREEMENT ON UPR LVL FORCING LAGGING BEHIND THE
FRONT TODAY...WITH THE FRONT LOSING ITS PUNCH AS IT ENTERS THE NC
MTNS THIS AFTN. FCST SNDGS ACRS THE PIEDMONT SHOW A SUBSIDENCE
INVERSION THAT IS SLOW TO ERODE THIS AFTN/EVE...RESULTING IN
GENERALLY LESS THAN 500 J/KG OF CAPE. TAKING A BLEND OF THE GFS AND
NAM FOR CAPE...I ONLY GET CHC THUNDER IN THE MTNS WITH NO MENTION
ACRS THE PIEDMONT. OVERALL...A MODEL BLEND OF THE POPS RESULTS IN A
CUT BACK FROM PREV FCST. ALL IN ALL...EXPECTING MAINLY GARDEN
VARIETY SHWRS/TSTMS IN THE MTNS THIS AFTN AND GENERALLY WIDELY SCT
SHWRS ACRS THE ENTIRE AREA THIS EVENING...TAPERING OFF OVERNIGHT
FROM NW TO SE. WITH THE FRONT HAVING AN ANAFRONT STRUCTURE...UPGLIDE
BEHIND THE SFC BNDRY MAY RESULT IN LINGERING SHWRS ALONG AND SOUTH
OF I-85 RIGHT UP TILL DAYBREAK. TEMPS SHUD BE ABLE TO WARM TO ABOVE
NORMAL READINGS EAST OF THE MTNS...AS THICKER CLOUDS AND MOISTURE
DOESN/T ENTER THE AREA TILL AFTER PEAK HEATING. LOWS OVERNIGHT NEAR
NORMAL.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 235 AM EDT WEDNESDAY...THE LATEST NAM AND GFS RUNS CLEAR OUT
CLOUD COVER BY ABOUT MID-MORNING ON THURSDAY. AS I DON/T THINK WE
WILL SEE THAT MUCH PCPN INTO THE PRE-FRONTAL AIRMASS OVER THE
FOOTHILLS AND PIEDMONT...I SUSPECT THAT LOW CLOUDS WON/T BE IN
ABUNDANCE IN THE FIRST PLACE. IT WILL BE A NICE AFTERNOON WITH
CLEAR...BLUE SKIES AND MAX TEMPS A COUPLE CATEGORIES BELOW NORMAL.
FROST STILL APPEARS LIKE A GOOD BET OVER THE NC MTNS AND POSSIBLY
THE WRN FOOTHILLS THURSDAY NIGHT. I/VE INCREASED THE AREAL COVERAGE
OF FROST IN THE WEATHER GRIDS TO ACCOUNT FOR THIS. SOME OF THE
TYPICAL COLD SPOTS AND/OR SHELTERED VALLEYS WILL WILL PROBABLY FALL
TO FREEZING.
FRIDAY WILL ALSO BE A NICE DAY...THOUGH MID AND HIGH LEVEL CLOUD
COVER WILL INCREASE DURING THE AFTERNOON HOURS AHEAD OF A SOUTHERN
STREAM SHORT WAVE. DESPITE THE HIGH CLOUDS...TEMPERATURES SHOULD BE
A FEW DEGREES WARMER THAN THURSDAY/S HIGHS.
FRIDAY NIGHT CLOUDS WILL CONTINUE TO THICKEN AND LOWER AND THERE
WILL BE A CHANCE OF RAIN LATER AT NIGHT...ESPECIALLY OVER THE
MOUNTAINS. THE PCPN WILL BE FORCED AS THE WRN CAROLINAS AND NE GA
WILL BE IN THE RT ENTRANCE REGION OF A 110 KT UPPER JET CENTERED
OVER ERN NC. A SRN STREAM JET MOVING ACROSS THE DEEP SOUTH MAY ALSO
CONTRIBUTE SOME LIFT TO THE SYSTEM. THE SFC COLD FRONT WILL BE WELL
TO OUR SOUTH...DOWN ALONG THE GULF COAST. THEREFORE THE PCPN SHOULD
BE HIGH BASED AND MORE STRATIFORM IN NATURE. ANY STRONG LLVL WARM
ADVECTION STAYS WELL SOUTHWEST OF THE REGION...CLOSER TO THE SFC-H8
FRONT...SO PCPN SHOULD BE LIGHT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM EDT WEDNESDAY...THE LATEST WPC EXTENDED DISCUSSION
FAVORS THE 12 UTC ECMWF FOR THE SAT-TUE PERIOD. LOOKING AT THEIR
EXTENDED RANGE GUIDANCE...THEY HAVE LIKELY POPS ON SATURDAY AND
SOLID CHANCE POPS SUN-TUE.
WHILE THE LATEST GFS IS WEAKER WITH THE FORCING...IT/S STILL IN
PRETTY GOOD AGREEMENT WITH THE 12 UTC RUN OF THE EC IN BRINGING A
SRN STREAM SHORT WAVE SLOWLY ACROSS THE REGION OVER THE WEEKEND.
UPGLIDE WILL INCREASE OVER A LLVL FRONTAL BNDRY...BRINGING PCPN TO
THE REGION. HOWEVER...THERE HAS BEEN A TREND IN THE MODELS TO
DEVELOP THE PCPN FARTHER SOUTH. THIS MAKES A LOT OF SENSE TO ME AS A
BELT OF STRONG MID-TROPOSPHERE FLOW WILL EXIST DOWN TOWARD THE GOM.
THE SFC BNDRY WILL LIKELY HAVE A DIFFICULT TIME LIFTING NORTH OF
THIS BAROCLINIC ZONE ALOFT...AND I CAN SEE QUITE A BIT OF
CONVECTION AND PCPN DEVELOPING DOWN TOWARD THE GULF...ESPECIALLY AS
WE GET INTO SUNDAY.
MONDAY AND TUESDAY THE SRN STREAM IS EVEN STRONGER AND FURTHER SOUTH
AS A MID-LATITUDE H5 RIDGE BEGINS TO DEVELOP OVER THE TN RIVER
VALLEY. THIS BLOCKING RIDGE PROVIDES A BROAD SEPARATION BETWEEN THE
NRN STREAM SHOOTING ACROSS THE NRN PLAINS AND THE SRN STREAM DOWN
ACROSS THE NRN GOM. WHILE WE WOULD CERTAINLY SEE SOME PCPN FROM THIS
PATTERN...I SUSPECT THAT MOST OF THE PCPN INTO MON AND TUE WILL
REMAIN SOUTH OF THE FORECAST AREA. THAT IS IF THIS PARTICULAR
PATTERN DOES EVOLVE. THIS IS NOT A HIGH CONFIDENCE FORECAST...AND
I/M NOT GOING TO DO ANYTHING DRAMATIC TO THE POPS ON THIS SHIFT.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...SCT CLOUDS IN THE 040-060 RANGE ARE IN STORE FOR EARLY
THIS AFTERNOON WITH BKN-OVC040 DEVELOPING ABOUT 21Z AS A COLD FRONT
APPROACHES FROM THE WEST. PRECIP ASSOCIATED WITH FRONT IS EXPECTED
TO DISSIPATE AS IT MOVES EAST OF THE MOUNTAINS WITH ONLY SCT LIGHT
SHOWERS AT BEST IN THE VICINITY OF THE AIRFIELD. EXPECT FRONTAL
PASSAGE CIRCA 03Z WITH WINDS GOING FROM SW-NW. VCSH 00Z-03Z WITH
ONLY MINOR RESTRICTIONS AT BEST WITH ANY SHOWERS. VFR CEILINGS WILL
SCATTER OUT BY 12Z.
ELSEWHERE...A COLD FRONT WILL MOVE ACROSS THE WESTERN CAROLINAS FROM
LATE AFTERNOON INTO TONIGHT. NUMEROUS SHOWERS AND EMBEDDED
THUNDERSTORMS WILL INTIALLY ENTER THE NC MOUNTAINS...BUT TEND TO
DISSIPATE AS THEY MOVE EAST OF THE MOUNTAINS AFTER SUNSET. CARRIED A
TEMPO AT KAVL FROM 22-24Z WITH MVFR RESTRICTIONS. OTHERWISE VCSH
WITH ONLY MINOR RESTRICTIONS AT BEST OTHER AIRFIELDS. VFR CEILINGS
WILL PREDOMINATE WITH CLOUDS SCATTERING OUT BY 12Z.
OUTLOOK...VFR CONDITIONS ARE EXPECTED THROUGH FRIDAY. THE NEXT
SYSTEM WILL BRING MOISTURE BACK INTO THE AREA FRIDAY NIGHT THRU THE
WEEKEND ALONG WITH POSSIBLE RESTRICTIONS.
CONFIDENCE TABLE...
17-23Z 23-05Z 05-11Z 11-17Z
KCLT HIGH 100% HIGH 100% HIGH 89% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 98% HIGH 100%
KAVL HIGH 100% HIGH 84% HIGH 87% MED 60%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 98% HIGH 100%
KAND HIGH 100% HIGH 93% LOW 58% LOW 57%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...LG
SHORT TERM...MCAVOY
LONG TERM...MCAVOY
AVIATION...LG
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
348 PM CDT WED APR 24 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 347 PM CDT WED APR 24 2013
AT 3 PM...A COLD FRONT EXTEND FROM INTERNATIONAL FALLS TO SIOUX
FALLS SOUTH DAKOTA. TEMPERATURES AHEAD OF THIS FRONT RANGED FROM
THE MID 40S TO MID 50S. MEANWHILE TEMPERATURES IN THE WAKE OF THIS
FRONT WERE IN THE 30S. THE 24.12Z AND 24.18Z MODELS ARE A BIT
SLOWER AT MOVING THIS FRONT THROUGH THE REGION TONIGHT...THUS
DELAYED THE PRECIPITATION ONSET AND ENDING BY ABOUT 3 HOURS. AHEAD
OF THE STRONG PV ANOMALY...BUFKIT SOUNDINGS SHOW AN INVERTED V
SOUNDING...AND THE STEEP AND UNSTABLE 950-400 MB LAPSE RATES. AS A
RESULT...EXPECT THE WINDS TO RATHER GUSTY THIS EVENING. WIND GUSTS
WILL RANGE FROM 30 TO 35 MPH. WITH CAPES UP TO 100 J/KG...THERE
WILL BE THE POTENTIAL FOR A FEW ISOLATED THUNDERSTORMS. AS
TEMPERATURES COOL IN THE WAKE OF THIS FRONT...THERE MAY BE A BRIEF
PERIOD OF SNOW. LITTLE...IF ANY...SNOW ACCUMULATIONS ARE
EXPECTED.
LATE TONIGHT AND THURSDAY...A WEAK RIDGE OF HIGH PRESSURE WILL
BUILD ACROSS THE AREA. THIS HIGH WILL PROVIDE WILL PROVIDE PARTLY
TO MOSTLY SUNNY SKIES. WITH 850 MB TEMPERATURES DURING THE
AFTERNOON FAIRLY SIMILAR TO THIS AFTERNOON...EXPECT VERY LITTLE
TEMPERATURE CHANGE BETWEEN THE 2 AFTERNOONS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 347 PM CDT WED APR 24 2013
ON THURSDAY NIGHT...A SHORT WAVE TROUGH WILL MOVE SOUTHEAST
ACROSS NORTHERN MINNESOTA AND NORTHERN WISCONSIN. THIS FRONT WILL
DRAG A WEAK COLD FRONT INTO THE REGION ON THURSDAY NIGHT...AND IT
WILL LINGER ACROSS THE SOUTHERN AND EASTERN PORTIONS OF THE
FORECAST AREA THROUGH FRIDAY EVENING. 925 MB AND 850 MB MOISTURE
TRANSPORT INTO THIS FRONT IS FAIRLY WEAK. THE MODELS GENERATE
SCATTERED SHOWERS ALONG THIS FRONT. THIS IS LIKELY DUE TO THE 0-3
KM MOST UNSTABLE CAPES UP TO 250 J/KG. AS A RESULT...JUST KEPT A
20 TO 30 PERCENT CHANCE OF SHOWERS IN THE FORECAST.
FOR THE UPCOMING WEEKEND...AN UPPER LEVEL RIDGE WILL PROVIDE DRY
WEATHER. SOUTHERLY WINDS WILL BRING WARM AIR INTO THE REGION. 850
MB TEMPERATURES WILL RANGE FROM 6 TO 10C ON SATURDAY...AND FROM 10
TO 14C ON SUNDAY. THIS WILL RESULT IN HIGH TEMPERATURES IN THE MID
AND UPPER 60S ON SATURDAY...AND LOWER 70S ON SUNDAY.
ON SUNDAY NIGHT...A CANADIAN COLD FRONT WILL MOVE SOUTHEAST
THROUGH THE FORECAST AREA. THIS FRONT WILL THEN RETURN BACK TO THE
NORTH ON MONDAY. THE COMBINATION OF WEAK TO MODERATE MOISTURE
TRANSPORT INTO THIS FRONT AND 0-3 KM MOST UNSTABLE CAPES OF 500 TO
1000 J/KG WILL RESULT IN THE DEVELOPMENT OF SCATTERED SHOWERS AND
THUNDERSTORMS. IF THIS FRONT IS ABLE TO MOVE MUCH FASTER NORTH OF
MONDAY...THERE WOULD BE THE POTENTIAL FOR SOME MID 70S TO OCCUR
SOUTH OF THE INTERSTATE 90 CORRIDOR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1225 PM CDT WED APR 24 2013
TWO AREAS OF CONCERN FOR THIS TAF CYCLE. FIRST IS GUST POTENTIAL
LATE THIS AFTERNOON AND EVENING AND THE SECOND IS THE POTENTIAL FOR
STRATUS LATER TONIGHT.
SHORTWAVE TROUGH WILL PUSH COLD FRONT ACROSS THE SITES THIS EVENING.
BAND OF SHOWERS EXPECTED AHEAD OF THIS FEATURE TO AFFECT THE KRST
TAF SITES AROUND 00Z-01Z AND KLSE IN THE 02Z-03Z TIME FRAME. EXPECT
CEILINGS TO LOWER LATE THIS AFTERNOON AND INTO THE EVENING...BUT
WITH THE DRY LOW LEVELS WILL REMAIN IN THE VFR CATEGORY. RATHER
STEEP LOW LEVEL LAPSE RATES WITH THE 24.15Z RAP SOUNDING SHOWING
AN INVERTED V-SOUNDING FAVORABLE FOR MIXING HIGHER GUSTS TO THE
SURFACE...WITH SOME ENHANCEMENT WITH THE STRONGER SHOWERS/ISOLATED
THUNDERSTORMS. THE 24.15Z ARXLAPS AND 24.15Z HRRR BOTH SHOWING
GUST POTENTIAL BETWEEN 25 AND 35 KNOTS IN THE SHOWERS...BUT THESE
WOULD BE ISOLATED AT BEST AND WILL NOT INCLUDE THE HIGHER GUSTS IN
THE TAFS.
NEXT CONCERN IS POST FRONTAL STRATUS. NOT MUCH SHOWING UP RIGHT NOW
OVER THE DAKOTAS AND LATEST GUIDANCE HAVE BACKED OFF ON THE LOWER
CEILING POTENTIAL...ALTHOUGH 24.12Z NAM AND 24.15Z RAP SOUNDINGS
SHOWING SOME MOISTURE AROUND 925 MPH. WILL KEEP MENTION OF JUST A
SCATTERED DECK BETWEEN 015-025K FEET AT THIS TIME.
OTHERWISE...SKIES SHOULD WILL BECOME CLEAR AFTER 12Z THURSDAY.
&&
.HYDROLOGY...WARMING TEMPERATURES THIS WEEKEND
ISSUED AT 347 PM CDT WED APR 24 2013
HIGHS IN THE 60S AND 70S AND LOWS IN THE 40S AND 50S FROM FRIDAY
THROUGH MONDAY WILL RESULT IN A RAPID INCREASE IN THE SNOW MELT RATE
AND RUNOFF ACROSS CENTRAL MINNESOTA AND NORTHERN WISCONSIN. THIS
SNOW MELT WILL PROVIDE RISES ALONG THE CHIPPEWA...ST CROIX AND
MISSISSIPPI RIVERS. THIS WILL EVENTUALLY FLOW DOWNSTREAM INTO THE
OUR AREA BY EARLY MAY. RIVER FORECASTS AND STATEMENTS WILL ADDRESS
THE MISSISSIPPI RIVER RISES AS DETAILS OF THE FINAL MELT AND
INFLOWS TO THE TRIBUTARY RIVERS BECOME CLEARER THIS WEEKEND AND
EARLY NEXT WEEK.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...RABERDING
HYDROLOGY...BOYNE
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 245 PM CDT WED APR 24 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A HIGH PRESSURE
RIDGE AXIS STRETCHING FROM THE SOUTHERN GREAT PLAINS ACROSS NE
WISCONSIN TO JAMES BAY EARLY THIS AFTERNOON. QUIET WEATHER EXISTS
ACROSS THE FORECAST AREA CURRENTLY...BUT MORE ACTIVE CONDITIONS EXIST
UPSTREAM OVER NE MINNESOTA. A WEAK SHORTWAVE IS PUSHING AN AREA OF
RAIN AND SNOW SOUTH OF DULUTH AND INTO NW WISCONSIN. BUT THE MAIN
SHORTWAVE TROUGH IS STILL OUT OVER NORTH DAKOTA WHERE SCATTERED RAIN
AND SNOW SHOWERS ARE FLYING. IN THE HEAVIER SNOW SHOWERS...VISIBILITIES
ARE FALLING TO AROUND A HALF TO THREE QUARTERS OF A MILE. AS THESE
SHORTWAVE TROUGHS PASS ACROSS THE FORECAST AREA TONIGHT...PRECIP
CHANCES AND AMOUNTS ARE THE MAIN FORECAST CONCERNS.
TONIGHT...THE MAIN SHORTWAVE TROUGH WILL SHARPEN AS IT DIGS ACROSS
THE NORTHERN MISSISSIPPI THIS EVENING AND THE STATE OF WISCONSIN
TONIGHT. A WEAK LITTLE WAVE OVER NORTHERN MINNESOTA WILL PUSH A
LEAD AREA OF PRECIP ENE ACROSS NORTH-CENTRAL WISCONSIN EARLY THIS
EVENING. DESPITE DEWPOINTS IN THE TEENS IN THIS REGION
CURRENTLY...PRECIP RATES LOOK IMPRESSIVE ENOUGH ON RADAR TO THINK
PRECIP WILL REACH THE GROUND EARLY THIS EVENING. THE PRECIP WILL BE
ARRIVING JUST AFTER PEAK HEATING...SO THINK PRECIP WILL START OUT AS
RAIN...THOUGH CANT RULE OUT SNOW FLAKES MIXING IN WITH THE RAIN
DROPS WITHIN THE HEAVIER SHOWERS. THE MAIN SHORTWAVE WILL THEN MOVE ACROSS
THE REGION LATE THIS EVENING THROUGH THE MIDDLE OF THE OVERNIGHT
PERIOD. SATELLITE AND RADAR UPSTREAM LOOK RATHER SHOWERY...PARTLY
CONTRIBUTED TO STEEP MID-LEVEL LAPSE RATES AROUND 8 C/KM. THINK
PRECIP WILL REMAIN SHOWERY TONIGHT DESPITE LOSS OF DIURNAL HEATING.
SURFACE WET BULB TEMPS STRUGGLE TO FALL BELOW FREEZING DURING THE
PERIOD THE PRECIP IS EXPECTED TO FALL...SO PTYPE WILL REMAIN
UNCERTAIN. THINK PRECIP WILL MAINLY BE RAIN OR A RAIN/SNOW MIX THIS
EVENING...CHANGING OVER TO SNOW AFTER MIDNIGHT AS SLIGHTLY COLDER
AIR MOVES IN BEHIND A SURFACE TROUGH. BUT THE ABOVE FREEZING WET
BULB TEMPS SUGGEST ACCUMS WILL BE LIMITED...PERHAPS A HALF INCH TO
AN INCH ON GRASSY SURFACES (HIGHER NORTH). PRECIP TO EXIT LATE
TONIGHT AND SKIES MAY PARTIALLY CLEAR OVER CENTRAL AND EAST-CENTRAL
WISCONSIN. LOWS IN THE UPPER 20S NORTH TO MID 30S SOUTH.
THURSDAY...SOME CLOUDS TO LINGER THURSDAY MORNING AND WILL GO
WITH A PARTLY TO MOSTLY CLOUDY START TO THE DAY AS RESIDUAL
MOISTURE AND CYCLONIC FLOW REACTS WITH DIURNAL HEATING.
HOWEVER...MIXING AND A WEAK 850MB RIDGE AXIS SHOULD LEAD TO
DECREASING CLOUDS IN THE AFTERNOON. HIGHS A DEGREE OR TWO COOLER
THAN TODAY.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 245 PM CDT WED APR 24 2013
MAIN FCST CONCERNS ARE PCPN TRENDS THU NGT INTO FRIDAY...AND
DURING THE EARLY TO MID PART OF THE NEXT WORK WEEK...AND FINALLY
SOME WARMER TEMPERATURES.
COOL NORTHWEST FLOW WILL BE REPLACED BY A ZONAL WESTERLY FLOW BY
THE WEEKEND...THEN BECOME MORE AMPLIFIED WITH SOUTHWEST FLOW AS A
TROF DEEPENS OVER THE ROCKIES AND NORTHERN PLAINS DURING THE EARLY
TO MID PART OF THE NEXT WORK WEEK. THE BIGGEST CHANGE WILL BE MUCH
WARMER AND ABOVE NORMAL TEMPS...WITH HIGHS WARMING INTO THE 60S
AND LOWER 70S FOR MOST OF THE PERIOD. THE WARMEST DAYS LOOK LIKE
THEY WILL OCCUR ON MONDAY AND TUESDAY.
FAIRLY STRONG WAA/ISENT LIFT WILL DEVELOP THURSDAY NIGHT...AND
CONTINUE INTO FRIDAY MORNING. IN ADDITION...A S/W TROF WILL TRACK
ACROSS THE REGION LATE THURSDAY NIGHT AND FRIDAY. RH/OMEGA
TIMESECTIONS INDICATE THAT MOISTURE WILL BE SOMEWHAT LACKING...
WITH PCPN NOT DEVELOPING UNTIL AFTER 09Z/FRI IN OUR WESTERN COUNTIES.
LOW-LEVEL THICKNESSES AND TEMPS INDICATE THAT PCPN SHOULD BE MAINLY
RAIN ACROSS CENTRAL WI...BUT A LIGHT MIX OF SNOW/SLEET/RAIN MAY
BRIEFLY OCCUR IN NC WI. DO NOT PLAN TO CARRY A MIX INTO FRIDAY...
AND WILL JUST HAVE A CHANCE OF SHOWERS ACROSS THE CWA.
GENERALLY DRY CONDITIONS ARE EXPECTED FROM FRIDAY NIGHT THROUGH
SUNDAY...MAKING FOR A VERY NICE AND MILD WEEKEND.
A WEAKENING COLD FRONT AND RRQ OF AN UPPER LEVEL JET WILL BRING A
CHANCE OF SHOWERS/ISOLD TSTMS TO OUR NW COUNTIES SUNDAY NIGHT. THE
FRONT IS EXPECTED TO BECOME ORIENTED MORE WEST TO EAST ACROSS THE
AREA ON MONDAY...THEN LIFT NORTH AS A WARM FRONT ON MONDAY NIGHT
AS LOW PRESSURE ORGANIZES IN THE NORTHERN PLAINS. THE THREAT OF
SHOWERS AND TSTMS WILL CONTINUE ALONG THIS BOUNDARY. A STRONGER...
BUT SLOW MOVING COLD FRONT WILL EDGE TOWARD THE AREA TUESDAY INTO
WEDNESDAY...WITH MAINLY POST-FRONTAL PCPN EXPECTED. PCPN ASSOCIATED
WITH THIS FEATURE SHOULD ARRIVE IN OUR NW COUNTIES TUES NGT...AND
ACROSS THE REST OF THE AREA ON WEDNESDAY.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1236 PM CDT WED APR 24 2013
VFR CONDITIONS FOR THIS AFTERNOON WITH INCREASING CLOUDS. PRETTY
STRONG UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE AREA TONIGHT.
AHEAD OF THE DISTURBANCE...RAIN AND SNOW SHOWERS EARLY THIS
EVENING WILL SWITCH OVER TO ALL SNOW LATE IN THE EVENING OR
OVERNIGHT. A FEW SNOW SHOWERS COULD BE RATHER INTENSE...DROPPING
VISIBILITIES UNDER A MILE. NOT LOOKING FOR MUCH ACCUMULATION...AS
TEMPERATURES WILL BE IN THE 32-36 DEGREE RANGE...BUT RATHER UP TO
AN INCH ON THE GRASSY SURFACES. PRECIPITATION WILL PEEL OUT LATE
TONIGHT AND A BKN MVFR CLOUD DECK WILL REMAIN OVERHEAD THROUGH MID
TO LATE MORNING. CLEARING THEREAFTER WILL LEAD TO A RETURN OF VFR
CONDITIONS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1225 PM CDT WED APR 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 338 AM CDT WED APR 24 2013
MAIN FORECAST CONCERNS THIS PACKAGE...PRECIP/THUNDER CHANCES LATE
THIS AFTERNOON/THIS EVENING...TEMPERATURES.
DATA ANALYSIS AT 06Z HAD A WEAK RIDGE OF HIGH PRESSURE FROM LK
SUPERIOR SOUTHWEST TO KS/NEB. WV IMAGERY SHOWED ONE MID LEVEL
TROUGH AXIS MOVING EAST ACROSS THE UPPER MIDWEST...WITH CLOUDS OVER
THE SOUTHEAST HALF OF THE REGION SLOWLY CLEARING TO THE EAST/SOUTH.
WHERE SKIES WERE CLEAR ACROSS MN/IA/WI...TEMPERATURES WERE QUICKLY
SLIPPING BELOW FREEZING...WITH SOME TEENS AGAIN OVER FAR NORTHERN
WI/NORTHEAST MN. WHAT A DIFFERENCE A YEAR MAKES...WITH THE NORTHERN
HALF OF THE REGION STILL SNOW-COVERED ON APRIL 24TH.
24.00Z MODELS INITIALIZED WELL AND OFFER REASONABLY SIMILAR
SOLUTIONS FOR TODAY AND TONIGHT. MODELS SHOWING SOME SUBTLE
DIFFERENCES AS THE VIGOROUS SHORTWAVE PASSES THIS EVENING...THE
MAIN ONE OF THESE LOOKS TO BE THE NAM BIAS OF NOT WANTING TO RAIN
FROM A MID CLOUD DECK THRU A DRY SFC-850MB LAYER. DPROG/DT OF 500MB
HGTS AT 24.00Z SHOWED THE MODEL RUNS OF 22.00Z AND 23.00Z VERIFIED
VERY WELL ACROSS NOAM/EASTERN PAC WITH BETTER RUN-TO-RUN CONSISTENCY
TO GFS/ECMWF. MODELS OFFERING A TIGHTENING CONSENSUS TODAY/TONIGHT
AS THE SASKAT SHORTWAVE DROPS SOUTHEAST ACROSS THE REGION. OVERALL
TREND IS SLIGHTLY WEAKER WITH THE SHORTWAVE AS IT CROSSES MN/WI
TONIGHT. CHECK OF OBS VS. MODEL DATA AT 06Z SHOWED ALL TO BE QUITE
GOOD WITH THE SFC MASS FIELDS OVER CENTRAL NOAM. PER WV IMAGERY ALL
LOOKED GOOD WITH THE SHORTWAVE DETAILS OVER NOAM. WITH NO CLEAR
MODEL FAVORITE AND THE TIGHT CONSENSUS...FAVORED THE MODEL/ENSEMBLE
CONSENSUS THIS CYCLE. SHORT-TERM FCST CONFIDENCE IS GOOD THIS CYCLE.
TODAY WILL START OUT COOL AND SUNNY/MOSTLY SUNNY AS A WEAK SFC-500MB
RIDGE AXIS MOVES ACROSS THE AREA. THIS WILL BE SHORT LIVED AS MID
LEVEL MOISTURE/CLOUDS AHEAD OF THE SHORTWAVE SPREADS QUICKLY
SOUTHEAST ACROSS THE AREA THIS AFTERNOON. TIGHT/CONSISTENT MODEL
SIGNAL FOR THE VIGOROUS SHORTWAVE DROPPING ACROSS SASKAT TO BE NEAR
THE MN/DAKOTAS BORDER BY 00Z THEN SWING EAST/SOUTHEAST ACROSS MN THIS
EVENING AND WI OVERNIGHT. MAIN SHOT OF MDT/STRONG 500-300MB PV
ADVECTION WITH SOME 850-700MB FN CONVERGENCE/MOISTURE TRANSPORT/
THETA-E CONVERGENCE MOVES QUICKLY ACROSS THE FCST AREA LATE THIS
AFTERNOON/EVENING. LIMITING FACTOR STILL LOOKS TO BE THE AMOUNT OF
MOISTURE THIS WAVE HAS TO WORK WITH AS MODEL CONSENSUS ONLY
INDICATES 1/4 TO 1/2 INCH OF PW LATE THIS AFTERNOON/EVENING AS THE
WAVE PASSES. MOST OF THIS ABOVE 850MB...WITH DRY...INVERTED V
SOUNDINGS BELOW 850MB. GIVEN THE STRENGTH OF THE MID LEVEL FORCING
LIFT AND THE PV ADVECTION ALOFT...WILL CONTINUE THE 70-90 PERCENT
-RA/-SHRA CHANCES AS THE SHORTWAVE PASSES LATE THIS AFTERNOON AND
THIS EVENING. WITH ITS QUICK PASSAGE AND THE DRIER LOW LEVEL AIR...
PRECIP WILL BE ON THE LIGHT SIDE. MODEL SOUNDINGS CONTINUE TO SHOW
SOME NEUTRAL OR VERY WEAK MID LEVEL INSTABILITY AHEAD OF THE 850-
500MB TROUGH AND THE SHORTWAVE SO WILL CONTINUE AN ISOLATED TSRA
MENTION IN THE 21-03Z TIME-FRAME. GIVEN LOW FREEZING LEVELS AND
THE DRIER LOW LEVEL AIR...GUSTY WINDS AND SMALL HAIL WILL BE
POSSIBLE WITH ANY TSRA AND EVEN ANY STRONGER SHRA. COLUMN COOLS
ENOUGH AS THE TROUGH PASSES FOR PRECIP TO MIX WITH/CHANGE TO SNOW
AROUND MIDNIGHT OVER THE NORTH PARTS OF THE FCST AREA. AGAIN...
ANY -SN AMOUNTS WOULD BE QUITE LIGHT.
EVEN WITH SOME SUNSHINE...HIGHS TO REMAIN COOL TODAY. USED A BLEND
OF THE NUMERICAL TEMP GUIDANCE FOR HIGHS/LOWS TODAY/TONIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 338 AM CDT WED APR 24 2013
THU THRU FRI NIGHT ENTERS INTO A GENERALLY DRY AND WARMING PERIOD AS
THE TROUGH EXITS QUICKLY EAST...HGTS RISE AND THE FLOW BECOMES
NEARLY ZONAL ACROSS SOUTHERN CAN. TIGHTER MODEL CONSENSUS
DEVELOPING FOR THU INTO SAT...WITH BETTER RUN-TO-RUN CONSISTENCY BY
ECMWF AND OTHER MODELS TRENDING TOWARD IT IN THIS TIME PERIOD.
AS LONGWAVE HGTS RISE OVER CENTRAL/WESTERN NOAM THU THRU FRI NIGHT...
ONE WEAK SHORTWAVE SLIDES THRU THE FLOW AND ACROSS THE REGION LATE
THU NIGHT/ FRI. RATHER CONSISTENT MODEL SIGNAL FOR MDT TO STRONG 925-
700MB WARM ADVECTION AND MOISTURE TRANSPORT/THETA-E CONVERGENCE TO
SPREAD ACROSS THE FCST AREA DURING THIS TIME PERIOD. PW VALUES
INCREASE INTO THE 1/2 TO 3/4 INCH RANGE...WITH SOUNDINGS SHOWING
DEEPEST COLUMN SATURATION IN THE THE COOLER AIRMASS OVER THE NORTH/
EAST END OF THE FCST AREA. GIVEN THE PERSISTENT MODEL SIGNAL FOR SOME
LIGHT QPF PRODUCTION...ADDED A SMALL -RA/-SN CHANCE TO THE NORTH END
OF THE FCST AREA LATE THU NIGHT AND TO MAINLY THE NORTH/EAST END OF
THE FCST AREA FRI AS THE AXIS OF STRONGEST MOISTURE TRANSPORT SLIDES
SOUTHEAST ACROSS THE FCST AREA. STRONG LOW LEVEL WARM ADVECTION THU
NIGHT/FRI AND MDT SOUTH TO SOUTHWEST WIND FLOW FINALLY SENDS
TEMPERATURES TO NEAR NORMAL FOR FRI/FRI NIGHT.
MEDIUM RANGE MODEL RUNS OF 24.00Z IN GOOD AGREEMENT SAT/SUN FOR THE
NEARLY ZONAL FLOW ACROSS ACROSS SOUTHERN CAN. FCST CONFIDENCE
REMAINS GOOD THRU SAT/SUN. THE STORM TRACK SHIFTS ACROSS SOUTHERN CAN
WITH LOWER LEVEL WARM ADVECTION AND SOUTH/ SOUTHWEST FLOW CONTINUING
OVER THE NORTH-CENTRAL CONUS. WARMING CONTINUES OVER THE UPPER
MIDWEST SAT/SUN WITH 925MB TEMPS IN THE +14 TO +18C RANGE BY SUN
AFTERNOON. MODEL CONSENSUS HIGHS IN THE 60S SAT AND IN THE 70F TO 75F
RANGE SUN LOOK WELL TRENDED AT THIS TIME.
IMPROVING MODEL CONSENSUS SUN NIGHT/MON FOR A STRONGER SHORTWAVE AND
LOW TO LIFT ACROSS SOUTH-CENTRAL CAN...WHICH DRAGS A WEAKENING COLD
FRONT INTO THE UPPER MIDWEST LATER SUN NIGHT/MON. PW VALUES INCREASE
AHEAD OF THIS FRONT WITH SOME WEAK TO MDT CAPE AHEAD OF THE FRONT AS
WELL. WITH MEDIUM FCST CONFIDENCE...SMALL -SHRA/TSRA CHANCE SUN
NIGHT/MON REASONABLE FOR NOW. WITH THE AREA LOOKING REMAIN AHEAD OF
THE FRONT MON...CONSENSUS HIGHS IN THE 70-75F RANGE FOR MON LOOK
GOOD.
MODEL DIFFERENCES INCREASE FOR MON NIGHT/TUE AS LONGER WAVE TROUGHING
MOVES EAST ACROSS THE NORTHERN CONUS. GFS FASTER...ECMWF SLOWER
AND THESE DIFFERENCES HAVE ON HOW FAST THE NEXT STRONGER COLD
FRONT PUSHES INTO THE UPPER MIDWEST. FCST CONFIDENCE BY TUE BELOW
AVERAGE. SMALL SHRA/TSRA CHANCES MON NIGHT/TUE AND LOWS/HIGHS
TRENDED TOWARD THE MODEL/ENSEMBLE CONSENSUS APPEAR WELL TRENDED
UNTIL MODELS DEVELOP A TIGHTER CONSENSUS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1225 PM CDT WED APR 24 2013
TWO AREAS OF CONCERN FOR THIS TAF CYCLE. FIRST IS GUST POTENTIAL
LATE THIS AFTERNOON AND EVENING AND THE SECOND IS THE POTENTIAL FOR
STRATUS LATER TONIGHT.
SHORTWAVE TROUGH WILL PUSH COLD FRONT ACROSS THE SITES THIS EVENING.
BAND OF SHOWERS EXPECTED AHEAD OF THIS FEATURE TO AFFECT THE KRST
TAF SITES AROUND 00Z-01Z AND KLSE IN THE 02Z-03Z TIME FRAME. EXPECT
CEILINGS TO LOWER LATE THIS AFTERNOON AND INTO THE EVENING...BUT
WITH THE DRY LOW LEVELS WILL REMAIN IN THE VFR CATEGORY. RATHER
STEEP LOW LEVEL LAPSE RATES WITH THE 24.15Z RAP SOUNDING SHOWING
AN INVERTED V-SOUNDING FAVORABLE FOR MIXING HIGHER GUSTS TO THE
SURFACE...WITH SOME ENHANCEMENT WITH THE STRONGER SHOWERS/ISOLATED
THUNDERSTORMS. THE 24.15Z ARXLAPS AND 24.15Z HRRR BOTH SHOWING
GUST POTENTIAL BETWEEN 25 AND 35 KNOTS IN THE SHOWERS...BUT THESE
WOULD BE ISOLATED AT BEST AND WILL NOT INCLUDE THE HIGHER GUSTS IN
THE TAFS.
NEXT CONCERN IS POST FRONTAL STRATUS. NOT MUCH SHOWING UP RIGHT NOW
OVER THE DAKOTAS AND LATEST GUIDANCE HAVE BACKED OFF ON THE LOWER
CEILING POTENTIAL...ALTHOUGH 24.12Z NAM AND 24.15Z RAP SOUNDINGS
SHOWING SOME MOISTURE AROUND 925 MPH. WILL KEEP MENTION OF JUST A
SCATTERED DECK BETWEEN 015-025K FEET AT THIS TIME.
OTHERWISE...SKIES SHOULD WILL BECOME CLEAR AFTER 12Z THURSDAY.
&&
.HYDROLOGY...WARMING TEMPERATURES THIS WEEKEND
ISSUED AT 338 AM CDT WED APR 23 2013
HIGHS IN THE 60S AND 70S AND LOWS IN THE 40S FOR FRIDAY THROUGH
MONDAY WILL RESULT IN A MUCH INCREASED SNOW MELT RATE AND RUNOFF
ACROSS CENTRAL MN INTO NORTHERN WI...UPSTREAM OF THE FCST AREA.
ALL OF THIS INCREASED WATER FLOW WILL CREATE DECENT RISES IN
CHIPPEWA...ST CROIX AND MISSISSIPPI RIVER BASINS AND THIS WILL
FLOW DOWN INTO THE LOCAL MISSISSIPPI RIVER AREA BY EARLY MAY.
RIVER FORECASTS AND STATEMENTS WILL ADDRESS THE MISSISSIPPI RIVER
RISES AS DETAILS OF THE FINAL MELT AND INFLOWS TO THE TRIBUTARY
RIVERS BECOME CLEARER THIS WEEKEND AND EARLY NEXT WEEK.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...RABERDING
HYDROLOGY....ZT/RRS