Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 05/01/12
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1003 PM MDT MON APR 30 2012
.AVIATION...
VFR CONDITIONS WILL CONTINUE AT THE TAF SITES FOR THE NEXT 24 H.
WILL SEE SOME GUSTY SW WINDS AT KALS AND THE SPANISH PEAKS REGION LATE
THIS AFTERNOON AND EARLY EVENING. ROSE
&&
.PREV DISCUSSION... /ISSUED 615 PM MDT MON APR 30 2012/
SHORT TERM...
HAVE CLEARED BACA COUNTY FROM THE SVR TS WATCH FOR THIS EVENING. LLVL
MOISTURE AND SHEAR ARE STILL PRESENT...BUT SUBSIDENCE BEHIND THE
DEPARTING SHORTWAVE THAT IS NOW SPARKING CONVECTION IN KS THRU THE
TX PANHANDLE HAS LEFT OUR AREA WITH CLEAR SKIES...AND DO NOT SEE
ANY TRIGGERS UPSTREAM. REST OF THE NIGHT LOOKS QUIET. 44
SHORT TERM...
(TONIGHT AND TUESDAY)
THE MAIN CONCERN IS THE POTENTIAL FOR SOME TSTMS...POSSIBLY
SEVERE...OVER THE FAR SERN PORTION OF THE STATE. DEW POINTS OVR THE
SERN CORNER OF THE STATE ARE STILL AROUND 50 F AND THE NAM12 SHOWS
THE 50S GETTING TO ABOUT THE STATE LINE BY 00Z AND THEN BACKING INTO
THE AREA AGAIN THIS EVENING. SATELLITE IMAGES SHOWING CU
DEVELOPMENT OVR ERN LAS ANIMAS...BACA AND PORTIONS OF PROWERS
COUNTIES...AND HAVE HAD ONE CELL SHOW UP ON RADAR OVR NERN NM SO FAR
THIS AFTERNOON. LATEST MESOSCALE ANALYSIS SHOWS 1000-1500 J/KG OF
CAPE OVR BACA COUNTY...WITH LI/S OF -3 TO -5C. THE NAM12 CONTINUES
TO KEEP THE CWA DRY THIS EVENING...WHILE THE HRRR SHOWS THE
POTENTIAL FOR SOME PCPN THIS EARLY EVENING OVR BACA COUNTY. A WEAK
SHORTWAVE TROF WL ALSO BE MOVING ACRS THE AREA...AND WITH THE DRY
LINE EXPECTED TO BE OVR OR NR THE SE PORTION OF THE STATE...WE COULD
SEE SOME THUNDERSTORMS DEVELOP OR MOVE INTO THAT AREA SO WL GO WITH
SOME ISOLD POPS. THUNDERSTORMS IN THAT AREA WL HAVE THE POTENTIAL
TO PRODUCE LARGE HAIL AND STRONG WINDS.
LATER TONIGHT CONVECTION SHOULD END AND THERE MAY JUST BE SOME HIGH
CLOUDS. ON TUESDAY...GENERALLY DRY WESTERLY FLOW ALOFT WL BE OVR
THE AREA...HOWEVER A SHORTWAVE TROF MOVING BY TO THE NORTH OF THE
AREA...COULD BRING SOME SHOWERS TO THE CENTRAL MTS. THE NAM KEEPS
PCPN JUST NORTH OF THE AREA...WHILE THE GFS PRINTS OUT SOME QPF
ALONG THE CONTDVD. HIGHS ON TUE SHOULD BE WELL ABOVE NORMAL OVR
MOST OF THE AREA.
LONG TERM...
(TUESDAY NIGHT THROUGH MONDAY)
MODELS STILL IN GOOD AGREEMENT THROUGH SATURDAY WITH UNCERTAINTY
HEADING INTO EARLY NEXT WEEK. THE PATTERN WILL BE CHARACTERIZED BY
BROAD TROUGHING OVER THE NORTHERN CONUS WITH SEVERAL DISTURBANCES
MOVING ACROSS THE ROCKIES THROUGH SATURDAY.
MODELS BRING A WEAK DISTURBANCE ACROSS THE ROCKIES PRETTY MUCH
EVERY DAY WEDNESDAY THROUGH FRIDAY. THE NORTHERLY TRACKS WILL KEEP
SHOWER AND THUNDERSTORM ACTIVITY CONFINED TO THE CENTRAL
MOUNTAINS. EXPECT ISOLATED CONVECTION TUESDAY EVENING WHICH WILL
QUICKLY DIE OUT AFTER SUNSET. MODELS INDICATING THE BEST CHANCE
FOR MORE WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY BEING
WEDNESDAY. AGAIN THE CENTRAL MOUNTAINS WILL BE THE FOCUS...WITH
THUNDERSTORMS POSSIBLE OVER THE LA GARITA RANGE AND SPREADING EAST
INTO THE NORTHERN SANGRES AND RAMPART RANGES DURING THE AFTERNOON.
SOME MODELS ARE BRINGING THIS SHOWER ACTIVITY OFF THE MOUNTAINS
AND INTO THE PALMER DIVIDE WEDNESDAY EVENING. THE WEAK SYSTEM
RESPONSIBLE FOR THIS SHOWER ACTIVITY WILL SHIFT EAST QUICKLY WITH
ALL SHOWER AND THUNDERSTORM ACTIVITY COMING TO AN END BY MIDNIGHT.
ANOTHER WEAK DISTURBANCE WILL SHIFT ACROSS THE NORTHERN ROCKIES ON
THURSDAY WITH ANOTHER ROUND OF ISOLATED SHOWERS AND THUNDERSTORMS
FOR THE CENTRAL MOUNTAINS. THE PERSISTENT SOUTHWESTERLY TO
WESTERLY FLOW WILL KEEP MIXING GOING OVER THE LOWER ELEVATIONS
WITH TEMPERATURES WELL INTO THE 80S EACH AFTERNOON.
THE PATTERN BEGINS TO BECOME MORE AMPLIFIED FRIDAY INTO SATURDAY
WITH LOW PRESSURE DEVELOPING OVER THE PACIFIC NORTHWEST AND HIGH
PRESSURE OVER THE CENTRAL PLAINS. THIS WILL TURN FLOW MORE
SOUTHWESTERLY WITH DRY WARM CONDITIONS FOR SOUTHERN COLORADO. AT
THIS TIME MOISTURE LOOKS LIMITED WHICH WILL LIKELY KEEP CONVECTION
TO A MINIMUM OVER THE CONTINENTAL DIVIDE WITH JUST CUMULUS BUILD
UPS EXPECTED. BEYOND SATURDAY...DIFFERENCES BEGIN TO ARISE
BETWEEN THE ECMWF AND THE INCONSISTENT GFS. THE ECMWF DROPS THE
PACIFIC NORTHWEST SYSTEM INTO THE GREAT BASIN WHERE IT IS FORECAST
TO SIT INTO EARLY NEXT WEEK. MEANWHILE CANADIAN HIGH PRESSURE WILL
SEND A FRONT INTO EASTERN COLORADO WITH COOL UPSLOPE FLOW AND
WIDESPREAD SHOWER ACTIVITY. THE GFS HAS SHOWN THIS SOLUTION EVERY
OTHER MODEL RUN...BUT HAS BEEN VERY INCONSISTENT. THE 12Z GFS RUN
HAS THE UPPER LOW REMAINING OVER THE PACIFIC NORTHWEST WITH
STRONGER SOUTHWESTERLY FLOW WHICH WILL KEEP THE CANADIAN HIGH
CENTERED FURTHER NORTH. THIS WILL KEEP THE SURFACE FRONT TO THE
NORTH WITH DRY WESTERLY FLOW OVERHEAD. DO FEEL THAT AT SOME POINT
IN EARLY TO MID NEXT WEEK...THE FRONT WILL MAKE IT THROUGH BUT
CONFIDENCE IS LOW IN WHEN...AND HOW MUCH PRECIP WE WILL RECEIVE
WHEN IT DOES. 88
AVIATION...
VFR CONDITIONS ARE EXPECTED AT THE TAF SITES TONIGHT AND
TUESDAY...AS GENERALLY DRY WESTERLY FLOW IS EXPECTED OVER THE AREA.
SOUTH TO SOUTHWEST WINDS AT 15-25 KTS ARE EXPECTED MOSTLY AFTER 18Z
ON TUE.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
44/27
AREA FORECAST DISCUSSION...UPDATED
NWS PUEBLO CO
615 PM MDT MON APR 30 2012
.SHORT TERM...
HAVE CLEARED BACA COUNTY FROM THE SVR TS WATCH FOR THIS EVENING. LLVL
MOISTURE AND SHEAR ARE STILL PRESENT...BUT SUBSIDENCE BEHIND THE
DEPARTING SHORTWAVE THAT IS NOW SPARKING CONVECTION IN KS THRU THE
TX PANHANDLE HAS LEFT OUR AREA WITH CLEAR SKIES...AND DO NOT SEE
ANY TRIGGERS UPSTREAM. REST OF THE NIGHT LOOKS QUIET. ROSE
SHORT TERM...
(TONIGHT AND TUESDAY)
THE MAIN CONCERN IS THE POTENTIAL FOR SOME TSTMS...POSSIBLY
SEVERE...OVER THE FAR SERN PORTION OF THE STATE. DEW POINTS OVR THE
SERN CORNER OF THE STATE ARE STILL AROUND 50 F AND THE NAM12 SHOWS
THE 50S GETTING TO ABOUT THE STATE LINE BY 00Z AND THEN BACKING INTO
THE AREA AGAIN THIS EVENING. SATELLITE IMAGES SHOWING CU
DEVELOPMENT OVR ERN LAS ANIMAS...BACA AND PORTIONS OF PROWERS
COUNTIES...AND HAVE HAD ONE CELL SHOW UP ON RADAR OVR NERN NM SO FAR
THIS AFTERNOON. LATEST MESOSCALE ANALYSIS SHOWS 1000-1500 J/KG OF
CAPE OVR BACA COUNTY...WITH LI/S OF -3 TO -5C. THE NAM12 CONTINUES
TO KEEP THE CWA DRY THIS EVENING...WHILE THE HRRR SHOWS THE
POTENTIAL FOR SOME PCPN THIS EARLY EVENING OVR BACA COUNTY. A WEAK
SHORTWAVE TROF WL ALSO BE MOVING ACRS THE AREA...AND WITH THE DRY
LINE EXPECTED TO BE OVR OR NR THE SE PORTION OF THE STATE...WE COULD
SEE SOME THUNDERSTORMS DEVELOP OR MOVE INTO THAT AREA SO WL GO WITH
SOME ISOLD POPS. THUNDERSTORMS IN THAT AREA WL HAVE THE POTENTIAL
TO PRODUCE LARGE HAIL AND STRONG WINDS.
LATER TONIGHT CONVECTION SHOULD END AND THERE MAY JUST BE SOME HIGH
CLOUDS. ON TUESDAY...GENERALLY DRY WESTERLY FLOW ALOFT WL BE OVR
THE AREA...HOWEVER A SHORTWAVE TROF MOVING BY TO THE NORTH OF THE
AREA...COULD BRING SOME SHOWERS TO THE CENTRAL MTS. THE NAM KEEPS
PCPN JUST NORTH OF THE AREA...WHILE THE GFS PRINTS OUT SOME QPF
ALONG THE CONTDVD. HIGHS ON TUE SHOULD BE WELL ABOVE NORMAL OVR
MOST OF THE AREA.
LONG TERM...
(TUESDAY NIGHT THROUGH MONDAY)
MODELS STILL IN GOOD AGREEMENT THROUGH SATURDAY WITH UNCERTAINTY
HEADING INTO EARLY NEXT WEEK. THE PATTERN WILL BE CHARACTERIZED BY
BROAD TROUGHING OVER THE NORTHERN CONUS WITH SEVERAL DISTURBANCES
MOVING ACROSS THE ROCKIES THROUGH SATURDAY.
MODELS BRING A WEAK DISTURBANCE ACROSS THE ROCKIES PRETTY MUCH
EVERY DAY WEDNESDAY THROUGH FRIDAY. THE NORTHERLY TRACKS WILL KEEP
SHOWER AND THUNDERSTORM ACTIVITY CONFINED TO THE CENTRAL
MOUNTAINS. EXPECT ISOLATED CONVECTION TUESDAY EVENING WHICH WILL
QUICKLY DIE OUT AFTER SUNSET. MODELS INDICATING THE BEST CHANCE
FOR MORE WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY BEING
WEDNESDAY. AGAIN THE CENTRAL MOUNTAINS WILL BE THE FOCUS...WITH
THUNDERSTORMS POSSIBLE OVER THE LA GARITA RANGE AND SPREADING EAST
INTO THE NORTHERN SANGRES AND RAMPART RANGES DURING THE AFTERNOON.
SOME MODELS ARE BRINGING THIS SHOWER ACTIVITY OFF THE MOUNTAINS
AND INTO THE PALMER DIVIDE WEDNESDAY EVENING. THE WEAK SYSTEM
RESPONSIBLE FOR THIS SHOWER ACTIVITY WILL SHIFT EAST QUICKLY WITH
ALL SHOWER AND THUNDERSTORM ACTIVITY COMING TO AN END BY MIDNIGHT.
ANOTHER WEAK DISTURBANCE WILL SHIFT ACROSS THE NORTHERN ROCKIES ON
THURSDAY WITH ANOTHER ROUND OF ISOLATED SHOWERS AND THUNDERSTORMS
FOR THE CENTRAL MOUNTAINS. THE PERSISTENT SOUTHWESTERLY TO
WESTERLY FLOW WILL KEEP MIXING GOING OVER THE LOWER ELEVATIONS
WITH TEMPERATURES WELL INTO THE 80S EACH AFTERNOON.
THE PATTERN BEGINS TO BECOME MORE AMPLIFIED FRIDAY INTO SATURDAY
WITH LOW PRESSURE DEVELOPING OVER THE PACIFIC NORTHWEST AND HIGH
PRESSURE OVER THE CENTRAL PLAINS. THIS WILL TURN FLOW MORE
SOUTHWESTERLY WITH DRY WARM CONDITIONS FOR SOUTHERN COLORADO. AT
THIS TIME MOISTURE LOOKS LIMITED WHICH WILL LIKELY KEEP CONVECTION
TO A MINIMUM OVER THE CONTINENTAL DIVIDE WITH JUST CUMULUS BUILD
UPS EXPECTED. BEYOND SATURDAY...DIFFERENCES BEGIN TO ARISE
BETWEEN THE ECMWF AND THE INCONSISTENT GFS. THE ECMWF DROPS THE
PACIFIC NORTHWEST SYSTEM INTO THE GREAT BASIN WHERE IT IS FORECAST
TO SIT INTO EARLY NEXT WEEK. MEANWHILE CANADIAN HIGH PRESSURE WILL
SEND A FRONT INTO EASTERN COLORADO WITH COOL UPSLOPE FLOW AND
WIDESPREAD SHOWER ACTIVITY. THE GFS HAS SHOWN THIS SOLUTION EVERY
OTHER MODEL RUN...BUT HAS BEEN VERY INCONSISTENT. THE 12Z GFS RUN
HAS THE UPPER LOW REMAINING OVER THE PACIFIC NORTHWEST WITH
STRONGER SOUTHWESTERLY FLOW WHICH WILL KEEP THE CANADIAN HIGH
CENTERED FURTHER NORTH. THIS WILL KEEP THE SURFACE FRONT TO THE
NORTH WITH DRY WESTERLY FLOW OVERHEAD. DO FEEL THAT AT SOME POINT
IN EARLY TO MID NEXT WEEK...THE FRONT WILL MAKE IT THROUGH BUT
CONFIDENCE IS LOW IN WHEN...AND HOW MUCH PRECIP WE WILL RECEIVE
WHEN IT DOES. 88
AVIATION...
VFR CONDITIONS ARE EXPECTED AT THE TAF SITES TONIGHT AND
TUESDAY...AS GENERALLY DRY WESTERLY FLOW IS EXPECTED OVER THE AREA.
SOUTH TO SOUTHWEST WINDS AT 15-25 KTS ARE EXPECTED MOSTLY AFTER 18Z
ON TUE.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
44/27
AREA FORECAST DISCUSSION
NWS MIAMI FL
225 PM EDT SUN APR 29 2012
.DISCUSSION...WATER VAPOR CONTINUES TO SHOW WELL DEFINED MID LEVEL
TROUGH OVER THE WESTERN CARIBBEAN EXTENDING NORTHEAST INTO THE FL
STRAITS. AT THE SFC, A BROAD TROUGH ALSO STRETCHES ACROSS ROUGHLY
THE SAME AREA WITH VISIBLE SATELLITE INDICATING BROAD CIRCULATION
AROUND THESE TWO FEATURES WITH A RICH PLUME OF TROPICAL MOISTURE
FEED ACROSS CUBA, FL STRAITS AND S FL. THE 12Z MFL SOUNDING
ALTHOUGH CONTAMINATED BY CONVECTION AT LAUNCH TIME SHOWS THE DEEP
EASTERLY FLOW.
LOOKING AT THE VERY SHORT TERM, THE HRRR WHICH HAS BEEN DOING
REMARKABLY WELL THE PAST COUPLE OF DAYS SHOWS A DECREASING TREND
THROUGH THIS AFTERNOON BUT THEN A REGENERATION OFF THE SE CST AFT
03Z THIS EVENING WHICH IS AT THE END OF ITS CURRENT FCST CYCLE. BOTH
THE GFS AND NAM PERSIST IN SHOWING A DEEPENING SFC TROUGH OVER THE FL
KEYS FROM LATE THIS AFTERNOON INTO THIS EVENING AND MOVING IT WEST
INTO THE SE GULF BY LATE MONDAY. THEY HAVE HOWEVER BOTH SCALED BACK
THE STRENGTH AND NO LONGER SHOW A CLOSED CIRCULATION SO WILL STICK
CLOSER TO THE NAM SPEEDS WHICH IS THE WEAKER OF THE TWO MODELS. THE
LONGER RANGE MODELS STILL DIVERGE AS TO THE EVOLUTION OF THESE
SYSTEMS THROUGH THE NEXT 24 TO 36 HOURS BUT ALL AGREE TO A CERTAIN
DEGREE THAT THE BAND OF MOISTURE WILL MOVE VERY LITTLE THROUGH
THIS TIME FRAME. RAINFALL ACCUMULATION IS ALSO TROUBLESOME WITH
THE NAM NOT SHOWING MUCH AFT 00Z THIS EVENING AND ALTHOUGH THERE
HAS BEEN SOME DECREASE IN THE OVERALL REFLECTIVITY FROM THE
REGIONAL RADARS, THE TROPICAL FEED WILL CONTINUE AND THUS THAT
SOLUTION SEEMS UNREALISTIC. THE GFS SEEMS TO BE SUFFERING FROM
CONVECTIVE FEEDBACK AS IT IS SHOWING A BULLS EYE 12 HOUR TOTAL
ENDING AT 18Z MONDAY OF IN EXCESS OF 8 INCHES ACROSS NORTHERN
MIAMI-DADE COUNTY. OF COURSE, GIVEN THESE HISTORIC PWAT ANOMALIES
FOR LATE APRIL THIS SOLUTION CANNOT BE TOTALLY RULED OUT HOWEVER
AND SOMEWHERE FROM BROWARD TO MIAMI- DADE COUNTIES MAY INDEED APPROACH
8 INCHES OR EVEN SLIGHTLY HIGHER BY LATE MONDAY WITH THE GREATEST
COASTAL CONVERGENCE LIKELY OCCURRING AT LOW LEVELS ALONG AND NEAR
THE SOUTHEAST COAST LATE TONIGHT THROUGH EARLY MONDAY. THE ECMWF
IS A MIDDLE OF THE ROAD APPROACH. SO WITH ALL OF THIS BEING SAID,
THE FLOOD WATCH WILL CONTINUE THROUGH MONDAY EVENING FOR THE EAST
COASTAL REGION.
HIGH PRESSURE WILL REMAIN TO THE NORTHEAST OVER THE WESTERN ATLANTIC
WITH THE PRESSURE GRADIENT REMAINING TIGHT SO STRONG COASTAL
CONVERGENCE MAY AGAIN SET UP MONDAY NIGHT INTO EARLY TUESDAY AS THE
HIGH MOISTURE REMAINS ACROSS THE AREA. THE ECMWF HAS COME MORE IN
LINE WITH THE GFS AND SHOWING THE DEEP MOISTURE REMAINING IN PLACE
THROUGH THE END OF THIS WEEK SO RAIN CHANCES WILL CONTINUE WITH THE
HIGHEST CHANCES FOR THE EAST COAST.
&&
.MARINE...DETERIORATING MARINE CONDITIONS WILL CONTINUE THROUGH
EARLY IN THE WEEK WITH SCA FOR ATLANTIC AND GULF WATERS. SEAS IN
THE GULF STREAM WILL LIKELY BE UP TO 8 FEET THROUGH LATE TUESDAY
BEFORE SUBSIDING BY THE MIDDLE OF THE WEEK AS THE GRADIENT WEAKENS.
&&
.FIRE WEATHER...NO PROBLEMS OR CONCERNS WITH AMPLE TROPICAL
MOISTURE IN PLACE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 73 80 73 82 / 60 60 40 50
FORT LAUDERDALE 72 79 74 83 / 80 70 50 50
MIAMI 70 80 72 83 / 80 70 50 50
NAPLES 68 82 70 86 / 40 50 30 50
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...FLOOD WATCH THROUGH MONDAY EVENING FOR COASTAL BROWARD-COASTAL
MIAMI DADE-COASTAL PALM BEACH-FAR SOUTH MIAMI DADE-INLAND
MIAMI DADE-METRO BROWARD-METRO MIAMI DADE-METRO PALM BEACH.
HIGH RIP CURRENT RISK THROUGH MONDAY AFTERNOON FOR COASTAL
BROWARD-COASTAL MIAMI DADE-COASTAL PALM BEACH.
AM...SMALL CRAFT ADVISORY UNTIL 8 AM EDT TUESDAY FOR COASTAL WATERS
FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-COASTAL
WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL OUT 20 NM-
WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL EXTENDING
FROM 20 NM TO THE TERRITORIAL WATERS OF THE BAHAMAS-WATERS
FROM JUPITER INLET TO DEERFIELD BEACH, FL EXTENDING FROM 20
NM TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR BISCAYNE BAY.
GM...SMALL CRAFT ADVISORY UNTIL 8 AM EDT TUESDAY FOR COASTAL WATERS
FROM CHOKOLOSKEE TO BONITA BEACH, FL OUT 20 NM-COASTAL
WATERS FROM EAST CAPE SABLE TO CHOKOLOSKEE, FL OUT 20 NM-
GULF WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL EXTENDING
FROM 20 TO 60 NM.
&&
$$
DISCUSSION/MARINE/FIRE...30/KOB
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
215 PM EDT SUN APR 29 2012
.SYNOPSIS...
18Z WATER VAPOR AND H4 RUC ANALYSIS SHOWING NORTHERN STREAM FLOW
CARVING OUT A LONGWAVE TROUGH INTO THE FOUR-CORNERS REGION AROUND A
LARGE CUTOFF LOW SPINNING OVER THE HIGH PLAINS. SHORTWAVE ENERGY
EJECTING EASTWARD FROM THE INTER-MOUNTAIN WEST OVER THE CENTRAL
PLAINS IS HELPING TO FORCE A LARGE AREA OF SHOWERS AND STORMS
ACROSS THE MIDDLE MS VALLEY. NORTHERN STREAM FLOW THEN RIDGES
NORTHWARD INTO THE GREAT LAKES BEFORE CARVING OUT ANOTHER TROUGH
OVER THE NORTHEASTERN STATES. CLOSER TO HOME...OUR FORECAST AREA IS
WEDGED BETWEEN UPPER LEVEL RIDGING OVER THE NORTHERN GULF COAST/SE
STATES...AND AN UPPER LEVEL DISTURBANCE FROM THE NW CARRIBEAN SEA TO
THE BAHAMAS. THIS ENERGY IS FORCING A LARGE AREA OF RAINFALL/THUNDER
OVER THE FAR SOUTHERN FL PENINSULA...FL STRAITS AND BAHAMAS. THE
DEEP COLUMN MOISTURE CONTINUES TO TRY AND MOVE NORTHWARD...BUT FOR
NOW IS STILL CONFINED TO AREAS SOUTH OF TAMPA BAY. ALTHOUGH THE 12Z
KTBW SOUNDING SHOWS SOME MOISTENING OVER THE PAST 24 HOURS WITH A PW
VALUE UP TO 1.25"...MIAMI`S KMFL PROFILE IS MUCH MORE MOIST WITH AN
ESSENTIALLY SATURATED COLUMN BELOW 500MB AND A PW VALUE OVER 2".
AT THE SURFACE...
FORECAST AREA REMAINS IN BETWEEN A RIDGE OF HIGH PRESSURE EXTENDING
FROM OFF THE SE COAST WESTWARD ALONG OR JUST NORTH OF THE I-10
CORRIDOR...AND A DEVELOPING LOW/INVERTED TROUGH OVER THE FL STRAITS.
LOW LEVEL FLOW BETWEEN THESE TWO FEATURES IS PROVIDING A LIGHT TO
MODERATE EASTERLY BREEZE.
&&
.SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)...
REST OF THIS AFTERNOON/EARLY EVENING...UPPER LEVEL SYNOPTIC SUPPORT
AND LOW LEVEL FOCUS FOR ASCENT WILL BE MAINTAINED OVER THE SOUTHERN
THIRD OF THE PENINSULA KEEPING A STEADY SUPPLY OF MOISTURE/SHOWERS
MOVING ASHORE (GENERALLY SOUTH OF A LINE FROM FORT MYERS TO WEST
PALM BEACH). SEEING SOME SCT CONVECTION DEVELOP INTO OUR SOUTHERN
ZONES THIS AFTERNOON DUE TO DIFFERENTIAL HEATING AND THE SYNOPTIC
SUPPORT ALOFT. FURTHER NORTH TOWARD THE TAMPA BAY REGION AND NATURE
COAST...THE INFLUENCE/SUPPRESSION FROM THE UPPER RIDGE SHOULD BE
MORE DOMINANT AND KEEP ANY AFTERNOON/EVENING SHOWER ACTIVITY VERY
ISOLATED (IF ANY). RAIN CHANCES WILL RANGE FROM THE HIGH END
CHANCE/LIKELY OVER THE FAR SOUTH...TO SLIGHT/CHANCE/CHANCE FOR
SARASOTA/MANATEE/HARDEE/DE SOTO...AND HIGHLANDS COUNTIES. FINALLY
SILENT 10% OR LESS RAIN CHANCES FROM PINELLAS/HILLSBOROUGH/POLK
COUNTIES NORTHWARD. WARMEST TEMPERATURES WILL ALSO BE OVER THE
NORTHERN ZONES WHERE MORE INSULATION/DEEP LAYER SUPPRESSION HAS
ALLOWED AFTERNOON HIGHS INTO THE UPPER 80S TO NEAR 90 AWAY FROM THE
COAST. THE THICKER CLOUDS TO THE SOUTH ARE HOLDING TEMPS IN THE
UPPER 70S DOWN TOWARD CHARLOTTE AND LEE COUNTIES.
MORE OF THE SAME OVERNIGHT. DIURNALLY FORCED SHOWERS FROM MANATEE TO
HIGHLAND COUNTIES WILL DISSIPATE WITH THE SETTING OF THE SUNSET.
ANY LINGERING SHOWER ACTIVITY WILL THEN BE CONFINED TO MAINLY LEE
AND CHARLOTTE COUNTIES. TEMPS WILL BE WARM (MID 60S TO LOW 70S) DUE
TO ABUNDANT LOW LEVEL MOISTURE STREAMING WESTWARD ACROSS THE
PENINSULA FROM THE ATLANTIC.
MONDAY THROUGH TUESDAY...
OVERALL SYNOPTIC PATTERN CHANGES LITTLE THROUGH THE REMAINDER OF THE
SHORT TERM PERIOD WITH THE SUBTROPICAL RIDGE AXIS HOLDING IN PLACE
TO OUR NORTH AND A SLOWLY WEAKENING AREA OF LOW PRESSURE MIGRATING
WESTWARD FROM THE FLORIDA STRAITS TO THE SOUTH-CENTRAL GULF OF
MEXICO. BEST CHANCES FOR ORGANIZED SHOWERS WILL REMAIN OVER THE FAR
SOUTHERN ZONES OF LEE AND CHARLOTTE IN CLOSER PROXIMITY TO THE UPPER
LEVEL SYNOPTIC SUPPORT AND LOW LEVEL FOCUS OF THE SURFACE TROUGH.
ONLY ISOLATED AFTERNOON CONVECTION (AT BEST) FURTHER NORTH FOR THE
REMAINDER OF THE FORECAST AREA UNDER INCREASING SUPPRESSION FROM THE
UPPER RIDGE. TEMPERATURES AT OR ABOVE NORMAL THROUGH THE PERIOD.
GREATEST DAYTIME INSULATION WILL OCCUR OVER THE CENTRAL AND NORTHERN
ZONES WHERE DAYTIME TEMPS WILL REACH WELL INTO THE 80S.
&&
.LONG TERM (WEDNESDAY THROUGH NEXT SUNDAY)...
THE GLOBAL MODELS GENERALLY AGREE THAT THE AREA REMAINS BETWEEN AN
UPPER LEVEL RIDGE TO THE NORTH AND TROUGHINESS TO THE SOUTH OR
SOUTHWEST...BUT THEY CONTINUE WITH SOME MINOR LOCATION AND TIMING
DIFFERENCES. AT THE SURFACE THERE IS BETTER CONSENSUS THAT HIGH
PRESSURE OVER THE WESTERN ATLANTIC RIDGES WEST...ALONG THE GULF
COAST...WITH A SLOWLY RELAXING GRADIENT. THIS PATTERN WILL KEEP THE
AREA IN EASTERLY TO SE LOW LEVEL FLOW...INITIALLY ROBUST BUT
SLACKENING ENOUGH BY THE WEEKEND TO ALLOW SEA BREEZE
CIRCULATIONS...WITH A MOIST AND SOMEWHAT UNSTABLE AIRMASS. THE
FORECAST WILL STAY PARTLY CLOUDY WITH ONLY A SLIGHT CHANCE OF
SHOWERS OR STORMS...BELOW THE MEX GUIDANCE AND CLOSER TO CLIMO.
TEMPERATURES WILL RUN JUST ON THE WARM SIDE OF NORMAL...BY UP TO
A COUPLE OF DEGREES AT TIMES.
&&
.AVIATION...
VFR CIGS FROM TPA-PGD AROUND 250. SCT SHOWERS MOVING ACROSS THE
SOUTHERN INTERIOR PUSHING TO THE WEST WILL CREATE A CHANCE OF
SHOWERS FROM SRQ SOUTH TO FMY/RSW THROUGH THE REMAINDER OF THE
AFTERNOON WITH LCL MVFR CIGS/VSBYS. LOSS OF DAYTIME HEATING SHOULD
DECREASE SHOWER ACTIVITY AFTER SUNSET. BULK OF RAIN SHOULD REMAIN
JUST SOUTH AND EAST OF THE AREA.
&&
.MARINE...
THE LOCAL GRADIENT WILL TIGHTEN OVER THE FORECAST WATERS INTO
TONIGHT BETWEEN A RIDGE OF HIGH PRESSURE TO OUR NORTH AND A SURFACE
TROUGH OVER THE FLORIDA STRAITS. WINDS WILL INCREASE TO ADVISORY
LEVELS THIS EVENING OVER THE SOUTHERN THIRD OF THE MARINE
AREA...WITH PERIODS OF CAUTIONARY WINDS FURTHER TO THE NORTH. THIS
GENERAL PATTERN WILL PERSIST THROUGH THE EARLY PORTION OF THE WORK
WEEK WITH THE POTENTIAL FOR PERIODS OF CAUTIONARY TO ADVISORY LEVEL
WINDS AND SEAS. LATE IN THE WEEK THE GRADIENT IS EXPECTED TO
GRADUALLY RELAX AND ALLOW WINDS AND SEAS OVER THE EASTERN GULF TO
SUBSIDE.
&&
.FIRE WEATHER...
EASTERLY FLOW BETWEEN HIGH PRESSURE TO OUR NORTH AND AN AREA OF LOW
PRESSURE OVER THE FLORIDA STRAITS WILL CONTINUE TO SUPPLY THE REGION
WITH ABUNDANT LOW LEVEL MOISTURE THROUGH AT LEAST TUESDAY. RELATIVE
HUMIDITY IS EXPECTED TO REMAIN GENERALLY ABOVE CRITICAL LEVELS THE
NEXT SEVERAL DAYS...AND NO SIGNIFICANT FIRE WEATHER CONCERNS ARE
FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 70 87 71 86 / 10 10 5 20
FMY 68 83 69 87 / 30 30 25 35
GIF 66 87 68 87 / 10 10 5 15
SRQ 68 86 68 87 / 10 10 10 20
BKV 65 89 65 88 / 5 5 5 10
SPG 71 83 73 82 / 10 10 5 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 8 AM EDT
TUESDAY FOR BONITA BEACH TO ENGLEWOOD OUT 20 NM-
BONITA BEACH TO ENGLEWOOD OUT 20 TO 60 NM.
&&
$$
SYNOPSIS/SHORT TERM/MARINE...MROCZKA
AVIATION/FIRE WEATHER...OGLESBY
LONG TERM...RUDE
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
955 AM EDT SUN APR 29 2012
.UPDATE (TODAY-TONIGHT)...
14Z WATER VAPOR AND H4 RUC ANALYSIS SHOWING NORTHERN STREAM FLOW
CARVING OUT A LONGWAVE TROUGH INTO THE FOUR-CORNERS REGION AROUND A
LARGE CUTOFF LOW SPINNING OVER THE HIGH PLAINS. SHORTWAVE ENERGY
WITHIN THIS FLOW IS NOW EJECTING EASTWARD FROM THE INTER-MOUNTAIN
WEST TOWARD THE CENTRAL PLAINS AND IS HELPING TO FORCE A LARGE AREA
OF SHOWERS AND STORMS FROM OK/KS EASTWARD TO THE MIDDLE MS VALLEY.
NORTHERN STREAM FLOW THEN RIDGES NORTHWARD INTO THE GREAT LAKES
BEFORE CARVING OUT ANOTHER TROUGH OVER THE NORTHEASTERN STATES.
CLOSER TO HOME...OUR FORECAST AREA IS WEDGED BETWEEN UPPER LEVEL
RIDGING OVER THE NORTHERN GULF COAST/SE STATES...AND AN UPPER LEVEL
DISTURBANCE FROM THE NW CARRIBEAN SEA TO THE BAHAMAS. THIS ENERGY IS
FORCING A LARGE AREA OF RAINFALL/EMBEDDED THUNDER OVER THE FAR
SOUTHERN FL PENINSULA...FL STRAITS AND BAHAMAS THIS MORNING. THE
DEEP COLUMN MOISTURE CONTINUES TO TRY AND MOVE NORTHWARD...BUT FOR
NOW IS STILL CONFINED TO AREAS SOUTH OF TAMPA BAY. ALTHOUGH THE 12Z
KTBW SOUNDING SHOWS SOME MOISTENING OVER THE PAST 24 HOURS WITH A PW
VALUE UP TO 1.25"...MIAMI`S KMFL PROFILE IS MUCH MORE MOIST WITH AN
ESSENTIALLY SATURATED COLUMN BELOW 500MB AND A PW VALUE OVER 2".
AT THE SURFACE...
FORECAST AREA REMAINS IN BETWEEN A RIDGE OF HIGH PRESSURE EXTENDING
FROM OFF THE SE COAST WESTWARD ALONG OR JUST NORTH OF THE I-10
CORRIDOR...AND A DEVELOPING LOW/INVERTED TROUGH OVER THE FL STRAITS.
LOW LEVEL FLOW BETWEEN THESE TWO FEATURES IS PROVIDING A LIGHT TO
MODERATE EASTERLY BREEZE ACROSS THE REGION.
REST OF TODAY/TONIGHT...UPPER LEVEL SYNOPTIC SUPPORT AND LOW LEVEL
FOCUS FOR ASCENT WILL BE MAINTAINED OVER THE SOUTHERN THIRD OF THE
PENINSULA KEEPING A STEADY SUPPLY OF MOISTURE/RAINFALL MOVING ASHORE
(GENERALLY SOUTH OF A LINE FROM FORT MYERS TO WEST PALM BEACH).
WOULD EXPECT TO SEE SOME SCT CONVECTION DEVELOP INTO OUR SOUTHERN
ZONES THIS AFTERNOON DUE TO DIFFERENTIAL HEATING AND THE SYNOPTIC
SUPPORT ALOFT. FURTHER NORTH TOWARD THE TAMPA BAY REGION AND NATURE
COAST...THE INFLUENCE/SUPPRESSION FROM THE UPPER RIDGE SHOULD BE
MORE DOMINANT AND KEEP ANY AFTERNOON/EVENING SHOWER ACTIVITY VERY
ISOLATED (IF ANY). RAIN CHANCES WILL RANGE FROM THE LIKELY RANGE FAR
SOUTH...TO SLIGHT/CHANCE/CHANCE FOR SARASOTA/MANATEE/HARDEE/DE
SOTO...AND HIGHLANDS COUNTIES...AND FINALLY SILENT 10% OR LESS RAIN
CHANCES FROM PINELLAS/HILLSBOROUGH/POLK COUNTIES NORTHWARD.
WARMEST TEMPERATURES WILL ALSO BE OVER THE NORTHERN ZONES WHERE MORE
INSULATION/DEEP LAYER SUPPRESSION WILL SOAR AFTERNOON HIGHS INTO THE
UPPER 80S TO NEAR 90 AWAY FROM THE COAST. THE THICKER CLOUDS AND
EVENTUALLY SHOWER CHANCES SHOULD HOLD TEMPS IN THE UPPER 70S/LOW 80S
DOWN TOWARD CHARLOTTE AND LEE COUNTIES.
MORE OF THE SAME OVERNIGHT WITH ANY SHOWER ACTIVITY CONFINED TO
MAINLY LEE AND CHARLOTTE COUNTIES...AND DRY CONDITIONS FURTHER
NORTH. TEMPS WILL BE WARM (MID 60S TO LOW 70S) DUE TO ABUNDANT LOW
LEVEL MOISTURE STREAMING WESTWARD ACROSS THE PENINSULA FROM THE
ATLANTIC.
&&
.AVIATION...
VFR CIGS FROM TPA-PGD AROUND 250...AREA OF RAIN JUST SOUTH OF
FMY/RSW WILL GRADUALLY EDGE NORTH WITH SHOWERS DEVELOPING BY
AFTERNOON OVER FMY/RSW WITH GENERALLY VFR CIGS/VSBYS BUT LCL MVFR
CIGS/VSBYS. SLIGHT CHANCE OF AFTERNOON SHOWERS FROM TPA TO PGD
LATER THIS AFTERNOON...BUT BULK OF THE RAIN WILL REMAIN JUST SOUTH
OF TERMINALS OVER SOUTHWEST FLORIDA.
&&
.MARINE...
LOW PRESSURE DEVELOPING IN THE FLORIDA STRAITS AND PUSHING SLOWLY
WEST OVER THE NEXT SEVERAL DAYS WILL BRING A TIGHTENING PRESSURE
GRADIENT AND INCREASING EASTERLY FLOW. WILL ADD SMALL CRAFT
ADVISORY TO SOUTHERN WATERS BEGINNING TONIGHT AS WINDS AROUND 20
KNOTS ARE EXPECTED AND SEAS INCREASING TO 6 FT. WILL REMAIN WITH
ELEVATED WINDS AND SEAS THROUGH EARLY TUESDAY AS THE LOW PRESSURE
MOVES INTO THE SOUTHERN GULF AND DISSIPATES. EASTERLY FLOW TO
CONTINUE THROUGH THE MAJORITY OF THE COMING WORK WEEK WITH A
STRONG RIDGE OF SURFACE HIGH PRESSURE SLIDING OFF THE EAST COAST
AND INTO THE SOUTHWEST ATLANTIC.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 90 71 87 71 / 10 10 10 5
FMY 83 69 83 69 / 60 30 40 30
GIF 89 68 86 68 / 10 10 10 5
SRQ 87 70 86 68 / 20 10 20 10
BKV 90 65 90 65 / 5 0 10 0
SPG 89 74 84 74 / 15 10 10 5
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 8
AM EDT TUESDAY FOR BONITA BEACH TO ENGLEWOOD OUT 20 NM-
BONITA BEACH TO ENGLEWOOD OUT 20 TO 60 NM.
&&
$$
UPDATE...14/MROCZKA
AVIATION...13/OGLESBY
AREA FORECAST DISCUSSION
NWS MIAMI FL
1253 AM EDT SUN APR 29 2012
.AVIATION...SURFACE TROUGH OF LOW PRESSURE CONTINUES TO MOVES VERY
SLOWLY WEST ACROSS SOUTHEAST FLORIDA WHILE A MID LEVEL LOW IS
CENTERED JUST OFF NORTHWEST CUBA. THESE FEATURES WILL TRANSPORT
CONSIDERABLE AMOUNTS OF MOISTURE INTO THE LOCAL AREA THROUGH THE
TAF PERIOD. VCSH IS WARRANTED FOR ALL TAF SITES, ALTHOUGH
PREVAILING RA WITH MVFR CEILINGS MAY BE ASSIGNED FOR A FEW
TERMINALS. A FEW TSRA ARE ALSO EXPECTED, BUT ANTICIPATED COVERAGE
TOO LOW TO INCLUDE VCTS ATTM. CEILINGS AND VISIBILITIES WILL
OCCASIONALLY BE REDUCED AND RESULT IN MVFR-IFR CONDITIONS. EAST
WINDS WILL AVERAGE 10 TO 15 KNOTS, WITH OCCASIONAL GUSTS TO 25
KNOTS, ESPECIALLY EAST COAST AFTER 12Z. EVEN HIGHER GUSTS ARE
POSSIBLE IN ANY HEAVIER SHRA/TSRA, MAINLY LATE IN THE FORECAST
PERIOD.
&&
.PREV DISCUSSION... /ISSUED 900 PM EDT SAT APR 28 2012/
UPDATE...CHALLENGING FORECAST FOR TONIGHT, BUT HERE GOES! RADAR
IMAGERY SHOWS A MID LEVEL LOW JUST NW OF ANDROS. THE LOCAL AREA IS
UNDER THE SUBSIDENCE SIDE OF THIS FEATURE. THIS IS RESULTING IN A
DRY EVENING BUT UNDER AN OVERCAST SKY. HOWEVER, IT STILL LOOKS AS
THOUGH THINGS COULD CHANGE QUICKLY AFTER MIDNIGHT FOR ESPECIALLY
THE SE COAST...BROWARD AND ESPECIALLY MIAMI-DADE. THE REASON
BEING A POTENT SHORTWAVE IS MOVING NORTH TOWARDS SOUTH FLORIDA
AROUND A MID LEVEL LOW JUST NORTH OF THE YUCATAN. TIMING OF THIS
SHORTWAVE IS TO THE SOUTHERN TIP OF THE FL PENINSULA BY 6 AM. DIVERGENCE
WILL INCREASE THROUGHOUT THE NIGHT OUT AHEAD OF THIS VERY
IMPRESSIVE SHORTWAVE, AND AS LOW LEVEL CONVERGENCE INCREASES
ALONG THE ATLANTIC COAST OVERNIGHT DUE TO INCREASING LOW LEVEL
FLOW, THIS COULD RESULT IN QUICK DEVELOPMENT OF SHRA/TSTORMS AFTER
MIDNIGHT. THE HRRR IS BULLISH ON REALLY DEVELOPING CONVECTION
ALONG THE ENTIRE ATLANTIC COAST AT AROUND THE MIDNIGHT TIME AND
CONTINUING THROUGH THE NIGHT. QPF FIELDS OFF BOTH THE GFS/ECMWF
SHOW A HIGH SIGNAL BETWEEN 06-12Z AS WELL...ESPECIALLY OFF THE
MIAMI-DADE COAST.
THERE COULD BE LOCALIZED HEAVY RAIN DEVELOPMENT OVERNIGHT. SHOULD
THIS OCCUR, BELIEVE THE MOST LIKELY LOCALE IS ALONG THE MIAMI-
DADE COAST...BUT CANNOT RULE OUT ANYWHERE ALONG THE ATLANTIC
COAST. DECREASED POPS SUBSTANTIALLY THROUGH MIDNIGHT, THEN HAVE
INCREASING POPS OVERNIGHT FOR THE SOUTH AND EAST COASTS...BUT KEPT
LOW POPS INLAND AND TO THE GREATER NAPLES AREA AS IT LOOKS TO STAY
MOSTLY DRY THERE OVERNIGHT.
SEE PREVIOUS DISCUSSION BELOW FOR FORECAST DETAILS BEYOND TONIGHT.
SHOULD MENTION THOUGH THAT THE LATEST 28.12Z RUN OF THE ECMWF
SHOWS LOW LEVEL WIND FIELDS INCREASING SUN NIGHT-MON...25-30 KT.
THE GFS CONTINUES STRONGER. EITHER WAY, WITH CONVECTION
AROUND...SHOWERS AND THUNDERSTORMS ESPECIALLY FROM SUNDAY NIGHT
THROUGH TUESDAY COULD BE ACCOMPANIED BY NOT ONLY TORRENTIAL RAINS
(LOCALIZED FLOODING CONCERNS ESPECIALLY ATLANTIC COAST), BUT ALSO
A GROWING CONCERN FOR SOME STRONG WIND GUSTS DUE TO CONVECTION IN
A FAST LOW LEVEL FLOW. AS FAR AS THE HEAVY RAIN RISK...IT LOOKS
AS THOUGH THIS RISK MAY CONTINUE EVEN INTO MID WEEK FOR THE EAST
COAST. HOWEVER, HIGHER THAN NORMAL UNCERTAINTY PRECLUDES ANY FLOOD
WATCH ISSUANCE AT THIS TIME. /GREGORIA
PREV DISCUSSION... /ISSUED 738 PM EDT SAT APR 28 2012/
AVIATION...FC TROF XTNDG FM UPR FLA STRAITS NE TO N BAHAMAS.
OVR NXT 24 HRS THIS TROF WL MOV SLOLY W ONTO S FLA WITH A MOIST
EASTERLY WND FLOW PERSISTING ACRS THE AREA. ALG E COAST...VCSH IN
TAFS AFT 09Z BUT WL PLC VCSH IN TAFS AFT 09Z AND AMD IF NEEDED IF
HVY PCPN ACTIVITY DVLPS. MVFR CIGS PSBL IN HVIER RA BUT VFR FOR
MOST PART. WND E 10 TO 15 KTS WITH OCNL HIR GUST BUT WND XPCTD TO
INCRS AFT 09Z WITH PSBL GUSTS > 20 KTS AFT 29/14Z. ATTM NO TSRA
IN TAFS THOUGH ISOLD TSRA PSBL THRU PD. AT KAPF...VFR THRU PD WITH
WND < 10 KTS BUT INCRG AFT 29/14Z 12-14 KTS WITH GUSTS > 20 KTS.
PREV DISCUSSION... /ISSUED 227 PM EDT SAT APR 28 2012/
DISCUSSION...THE DAY IN THE LIFE OF A FORECASTER CAN BE QUITE
TUMULTUOUS AND TODAY IS CERTAINLY NO EXCEPTION. GOING INTO THE
FIRST AND SECOND PERIODS THE MODELS ARE STILL DIVERGING ON HOW TO
HANDLE WHERE THE GREATEST CONVERGENCE AND LIFT WILL BE TO SET UP
CONVECTIVE PRECIPITATION. WATER VAPOR CONTINUES TO SHOW A PLUME OF
RICH TROPICAL MOISTURE FLOWING NORTH ALONG A MID LEVEL TROUGH AXIS
OVER THE WESTERN CARIBBEAN. RADAR SIGNATURES INDICATE THAT AT THE
SFC A CONVERGENT BOUNDARY IS SUGGESTED ALONG THE EXTREME SOUTHERN
TIP OF THE PENINSULA AND EXTENDING INTO THE BAHAMAS. SCT SHRA HAVE
DEVELOPED ALONG THIS BOUNDARY WITH ALSO ISOLD TSRA MAINLY FROM
CENTRAL BROWARD SOUTH ACROSS CENTRAL MIAMI-DADE COUNTIES AND ARE
MOVING WEST IN THE LOW LEVEL EASTERLY FLOW AROUND A SFC RIDGE THAT
STRETCHES ACROSS N FL. SO THIS CONTINUES THE THREAT FOR LATER
DEVELOPMENT ALONG THE COASTAL COLLIER COUNTY REGION THIS
AFTERNOON. BOTH THE NAM AND GFS INITIALIZED QUITE WELL DEPICTING
THIS BOUNDARY AND INTENSIFY THE TROUGH MOVING IT WEST ACROSS S FL
LATE TONIGHT AND SUNDAY THEN INTO THE SOUTHEAST GULF BY SUNDAY
NIGHT WHEREAS THE ECMWF DOES NOT SHOW THE TROUGH. AS THIS TROUGH
DEEPENS AND MOVES WEST, THE NAM DEVELOPS A BAND OF HEAVY
CONVECTION MOVING IT OVER THE SOUTHERN PORTIONS OF THE CWA WITH IN
EXCESS OF TWO INCHES OF RAINFALL BY LATE SUNDAY OVER SOUTHERN
MIAMI-DADE COUNTY WHILE THE GFS KEEPS THE HEAVIEST ACTIVITY
OFFSHORE AS DOES THE ECMWF. ALTHOUGH THE GFS DOES SHOW THE HIGHEST
RAINFALL TOTALS REMAINING OFFSHORE, IT DOES GIVE HIGHER POPS THAN
THE ECMWF WHICH SEEMS REASONABLE GIVEN ITS AGREEMENT TO THE NAM ON
THE SFC TROUGH POSITION. GIVEN ALL OF THIS, WILL LEAN MUCH CLOSER
TO THE NAM AND GFS AS IT MAKES MORE SENSE TO HAVE PLENTY OF
SHRA/TSRA MOVING ONSHORE WITH THE LOW LEVEL EAST WIND FLOW IN
PLACE.
IN ADDITION, WITH THE NAM AND GFS CONTINUING TO SHOW A DEVELOPING
SFC TROUGH THEY BOTH INCREASE THE WIND ACROSS THE LOCAL AREA ON
SUNDAY WITH SCA CONDITIONS OVER THE ATLANTIC WATERS. THIS COULD ALSO
SET UP GOOD COASTAL CONVERGENCE ALONG THE E CST LATE TONIGHT INTO
EARLY SUNDAY FOR POSSIBLE LOCALLY HEAVY RAINFALL IN SOME LOCATIONS
ESPECIALLY FROM EAST CENTRAL BROWARD AND SOUTH ALONG AND NEAR THE
COAST OF MIAMI-DADE COUNTY.
FOR THE EXTENDED, THE GFS KEEPS THE DEEP MOISTURE ACROSS THE REGION
THROUGH THE END OF THE WEEK WHEREAS THE ECMWF BUILDS A DEEP LAYER
RIDGE OVER THE ATLANTIC AND SUPPRESSES THE MOISTURE SOUTH OF THE
REGION. SO ONE SOLUTION WOULD BE MOSTLY DRY AND THE OTHER WOULD HAVE
HIGH END CHANCE POPS ACROSS THE REGION. WITH THE EASTERLY FLOW
EXPECTED...KEPT 20-40 POPS FOR THE EXTENDED THROUGH THE END OF THE
WEEK. HIGH TEMPERATURES ARE EXPECTED TO REMAIN IN THE 80S WITH LOWS
IN THE 60S TO LOWER 70S THROUGH THE ENTIRE PERIOD.
MARINE...MARINE CONDITIONS REMAIN UNCERTAIN WITH MODELS
DIVERGING ON THE STRENGTH OF A SFC BOUNDARY THAT MOVES NORTH
ACROSS S FL OVER THE REMAINDER OF WEEKEND. FOR NOW...AM LEANING
TOWARDS A GENERAL EAST WIND INCREASING ON SUNDAY TO AROUND 20
KNOTS OVER THE ATLANTIC WATERS WITH SEAS BUILDING TO POSSIBLY 6
FEET.
FIRE WEATHER...NO PROBLEMS OR CONCERNS WITH PLENTY OF TROPICAL
MOISTURE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 81 72 82 73 / 40 50 50 30
FORT LAUDERDALE 80 72 82 74 / 60 50 50 40
MIAMI 81 72 81 73 / 60 50 50 40
NAPLES 83 69 83 70 / 40 30 40 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AVIATION...14/MJB
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
154 AM EDT SUN APR 29 2012
.SYNOPSIS...
A COLD FRONT WILL MEANDER ACROSS THE MIDLANDS TONIGHT THROUGH
SUNDAY. MID AND UPPER LEVEL HIGH PRESSURE RIDGE INTO THE
SOUTHEASTERN STATES WILL HOLD TEMPERATURES ABOVE NORMAL FOR MUCH
OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
FRONTAL BOUNDARY HAS PUSHED SOUTH OF THE COLUMBIA AREA ALONG WITH
EXTENSIVE CLOUDINESS. WEAK WEDGE CONTINUES ACROSS THE NORTHERN
MIDLANDS WHERE TEMPERATURES REMAIN IN THE LOWER 60S. RUC MODEL
APPEARS TO HAVE THE BEST HANDLE ON SITUATION WITH DIFFUSE FRONT
ACROSS THE REGION OVERNIGHT AND WEAK NORTHEAST LOW-LEVEL FLOW.
CLOUDINESS WILL LIKELY REMAIN FROM CAE NORTH REDUCING FOG THREAT
IN THE MORNING. DRIER AIR IN THE AGS AREA MAY ALSO HINDER FOG
DEVELOPMENT. SREF KEEPS FOG ACROSS THE COASTAL PLAIN. ADJUSTED
WINDS/TEMPERATURE OVERNIGHT.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
THE FRONTAL BOUNDARY MEANDERING ACROSS THE CWA WILL SLOWLY MOVE
NORTHWARD SUNDAY...BUT THEN BEGIN TO DIP ONCE AGAIN SOUTHWARD
SUNDAY NIGHT INTO MONDAY AS MID/UPPER LEVEL RIDING BUILDS ACROSS
THE SOUTHEAST. THE REMNANTS OF FRONTAL BOUNDARY SHOULD FINALLY PUSH
NORTH OF THE CWA OVERNIGHT ON MONDAY NIGHT. MODELS IN GOOD
AGREEMENT THAT MID/UPPER LEVEL RIDGING WILL BUILD ACROSS THE
SOUTHEAST THROUGH THE PERIOD. THIS WILL ALLOW TEMPERATURE TO RISE
EVEN MORE ABOVE NORMAL FOR BOTH SUNDAY. TEMPERATURES WILL BE
SLIGHTLY COOLER ESPECIALLY ACROSS THE NORTHERN CWA AS FRONTAL
BOUNDARY SLIPS BACK SOUTHWARD LATE SUNDAY INTO SUNDAY NIGHT.
TEMPERATURES WILL APPROACH 90 DEGREES IN SOME LOCATIONS SUNDAY.
MODELS AND ENSEMBLES NOT VERY CONFIDENT ON CHANCES FOR RAINFALL
WITH BOUNDARY IN THE VICINITY. MOST POPS REMAIN BELOW 15 PERCENT
THROUGH THE PERIOD. AS FOR LOW TEMPERATURES THROUGH THE
PERIOD...GUIDANCE AND LOCAL NUMBERS REASONABLY CLOSE AND WILL STAY
NEAR CONSENSUS THROUGH THE PERIOD.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
THE LONG TERM PERIOD WILL BEGIN WITH MID/UPPER LEVEL RIDGING
ACROSS THE SOUTHEAST ON TUESDAY. THIS WILL CONTINUE THROUGH
THURSDAY...WITH A GRADUAL WEAKENING OF THE RIDGE OVER THE REGION
AS IT BEGINS TO SHIFT WESTWARD TOWARD TEXAS BY FRIDAY/SATURDAY. AT
THE SURFACE...HIGH PRESSURE OVER THE WESTERN ATLANTIC WILL RIDGE
INTO SOUTH CAROLINA AND GEORGIA THROUGH THURSDAY. RIDGING ACROSS
THE AREA WILL ALLOW TEMPERATURES TO REMAIN WELL ABOVE NORMAL
THROUGH THE PERIOD. EXPECT MIDDLE TO UPPER 80S...MAYBE EVEN A FEW
TEMPERATURES AROUND 90 THROUGH THE PERIOD. BY FRIDAY AND
SATURDAY...H5 HEIGHTS BEGIN TO LOWER ACROSS THE REGION AND HIGH
PRESSURE SETTLES FARTHER SOUTH AND EAST. BOTH ECMWF/GFS INDICATE A
WEAK FRONT MOVING ACROSS THE AREA FRIDAY NIGHT. THIS WILL ALLOW
FOR SOME SLIGHTLY COOLER TEMPERATURES FOR THE END OF THE EXTENDED
PERIOD. MUCH OF THE EXTENDED PERIOD LOOKS DRY. BUT CANNOT RULE OUT
AN ISOLATED AFTERNOON SHOWER OR STORM THROUGH THE ENTIRE WEEK.
HAVE INCLUDED A SLIGHT CHANCE FOR A SHRA/TSRA FRIDAY/FRIDAY NIGHT
FOR THE NORTHWEST PORTION OF THE CWA.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
MVFR TO IFR CONDITIONS THROUGH MID MORNING...THEN IMPROVING TO
VFR. FOG HAS ALREADY BEGUN TO DEVELOP ACROSS THE REGION WITH MVFR
CIGS OVER AND NORTHWEST OF CAE/CUB. EXPECT THE FOG TO EXPAND
THROUGH DAYBREAK WITH LESS EXPANSION OF THE LOW CLOUDS. HAVE
LOWERED VSBYS AT ALL TAF SITES BETWEEN 08Z AND 13Z DUE TO CURRENT
OBSERVATION TRENDS. FOG WILL ERODE WITH SUNRISE AND
MIXING...HOWEVER EXPECT 14Z TO BE THE TARGET FOR EROSION OF ALL
FOG. SOME CUMULUS WILL DEVELOP DURING THE LATE MORNING AND
AFTERNOON WITH DISSIPATION OF CLOUDS AT SUNSET. FOG WILL AGAIN BE
POSSIBLE AFTER 30/06Z...HOWEVER CONFIDENCE IN TIMING AND COVERAGE
IS TOO LOW TO INCLUDE ATTM.
EXTENDED AVIATION OUTLOOK MONDAY THROUGH THURSDAY...NO SIGNIFICANT
IMPACTS TO AVIATION EXPECTED MONDAY THROUGH THURSDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
632 PM EDT SUN APR 29 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 352 PM EDT SUN APR 29 2012
A BROAD QUASI ZONAL TO SOUTHWEST FLOW WILL MAINTAIN ITSELF OVER
MOST OF THE NEXT WEEK...WITH SEVERAL FRONTAL WAVES AND THUS
OPPORTUNITIES FOR SHOWERS AND THUNDERSTORMS PRESENTING THEMSELVES
ACROSS CENTRAL INDIANA. THIS SOUTHWEST FLOW WILL ALSO ALLOW
TEMPERATURES TO BE SEASONABLY WARM FOR MUCH OF THE NEXT WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 352 PM EDT SUN APR 29 2012
FOCI FOR TONIGHT ARE POPS AND THUNDER CHANCES. MODELS ARE IN
GENERAL AGREEMENT ON LARGE SCALE FEATURES...BUT LEANED TOWARD NAM
AS OTHER MODELS APPEAR TO BE TOO WET BASED ON CURRENT TRENDS.
WARM FRONT SHOULD GRADUALLY PUSH NORTHWARD TONIGHT...AS A WEAK
SURFACE LOW MOVES OUT OF THE CENTRAL PLAINS. MOST GUIDANCE
APPEARED A BIT TOO AGGRESSIVE ON PRECIP WHEN MUCH OF THE
CONVECTION TO OUR WEST HAS STRUGGLED TO MAKE IT EASTWARD TODAY.
RAPID REFRESH AND RUC DEPICT BEST CHANCES OF PRECIP TONIGHT ACROSS
OUR NORTHWEST...AND CONSENSUS APPROACH TEMPERED SLIGHTLY DEPICTS
THIS WELL. INSTABILITY IS THERE BUT MINIMAL...AND BASED ON SREF
THUNDER PROBS HAVE GONE WITH ISOLATED THUNDER MENTION RATHER THAN
STRAIGHT THUNDERSTORM FORECAST. DID GO WITH CHANCE THUNDER IN THE
NORTHWEST LATE WHERE PROBABILTIES ARE A BIT HIGHER.
CONSENSUS APPROACH ON TEMPS AGREES WELL WITH UPSTREAM MINS FROM
LAST NIGHT...AND WILL STICK CLOSE TO THIS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
ISSUED AT 352 PM EDT SUN APR 29 2012
FOCUS REMAINS PRECIP CHANCES THROUGHOUT...WITH BOUNDARY REMAINING
IN THE AREA IN ONE FORM OR ANOTHER AND ONE OR MORE VERY SUBTLE
WAVES PERHAPS AIDING SHOWER AND THUNDERSTORM DEVELOPMENT. POPS
APPEARED A BIT HIGH IN PLACES...BUT NOT BY MUCH...GIVEN THE LACK
OF SIGNIFICANT UPPER LEVEL SUPPORT THROUGH THE FIRST PART OF THE
WEEK. HOWEVER...EXPECT THAT MESOSCALE INFLUENCES WILL HELP MAKE UP
FOR THIS. LEANED HEAVILY ON SREF THUNDER PROBS AND BOUNDARY
POSITION FOR DELINEATING BETWEEN WHERE TO FORECAST STRAIGHT
THUNDERSTORMS AND WHERE TO GO MORE SHOWERS WITH ISOLATED THUNDER
MENTION.
SLIGHT RISK FOR TOMORROW AND SEE TEXT FOR TUESDAY APPEAR
REASONABLE BASED ON MODEL CAPE/SHEAR PROFILES. IN SOMEWHAT TYPICAL
FASHION...AFTERNOON AND EARLY EVENING WOULD BE PREFERRED TIMES FOR
SEVERE BOTH DAYS.
ON TEMPS...GENERALLY A CONSENSUS APPROACH LOOKED OK...EXCEPT IT
APPEARED TO BE A FEW DEGREES COOL IN MOST PERIODS BASED ON LOW
LEVEL THICKNESSES. MINOR TWEAKS UPWARD WERE REQUIRED.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
ISSUED AT 230 PM EDT SUN APR 29 2012
ECMWF AND GFS HINT AT A LINGERING FRONTAL BOUNDARY AND NUMEROUS
WEAK SHORT WAVES PUSHING THROUGH THE OHIO VALLEY THROUGH THE FIRST
PART OF THE WEEKEND. CONFIDENCE IN THESE FEATURES IS
LOW...ALTHOUGH GIVEN THE PATTERN...LOW CHANCE POPS WILL BE NEEDED
THROUGH MUCH OF THE WORK WEEK. ALL BLEND HANDLES THIS RATHER WELL.
BY NEXT SUNDAY...THE ECMWF IS SIGNALING A CHANGE AS HIGH PRESSURE
BUILDS ACROSS THE GREAT LAKES...PUSH THE FRONTAL BOUNDARY SOUTH.
FOR NOW THIS WILL BE THE MAIN PERIOD WHERE WE WILL BE ABLE TO
REMOVE THE POPS.
THE SOUTHERLY FLOW EXPECTED THROUGH THE PERIOD ALONG WITH SHOULD
PROVIDE ABOVE NORMAL TEMPERATURES THROUGH MUCH OF THE WEEK.
&&
.AVIATION /DISCUSSION FOR THE 300000Z TAFS/...
ISSUED AT 632 PM EDT SUN APR 29 2012
TAIL END OF UPPER DISTURBANCE PASSING OVER NORTHERN ILLINOIS IS
EXPECTED TO BE IN THE PROCESS OF MOVING ACROSS THE LOCAL AREA BY THE
BEGINNING OF THE FORECAST PERIOD. NOTHING REALLY DEVELOPING ON THIS
TAIL...BUT THERE IS SOME ELEVATED INSTABILITY AROUND. AS A
RESULT...THERE IS A LOW POTENTIAL FOR CONVECTION IN THE VICINITY OF
THE TAF SITES THROUGH ABOUT 300200Z...BUT NOT ENOUGH TO PUT IN THE
FORECAST AT THIS TIME.
MODEL DATA SUGGEST THERE MAY BE ANOTHER DISTURBANCE MOVING INTO THE
AREA OUT OF THE SOUTHERN PLAINS AFTER 300800Z...BUT AGAIN COVERAGE
OF CONVECTION TOO QUESTIONABLE TO PUT IN THE FORECAST AT THIS TIME.
CEILINGS GENERALLY ABOVE 050 EXPECTED TO LOWER INTO THE 030-050
RANGE AFTER 300600Z WITH THE APPROACH OF WARM FRONT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD
SHORT TERM...NIELD
LONG TERM....PUMA
AVIATION...JAS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
425 PM EDT SUN APR 29 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 352 PM EDT SUN APR 29 2012
A BROAD QUASI ZONAL TO SOUTHWEST FLOW WILL MAINTAIN ITSELF OVER
MOST OF THE NEXT WEEK...WITH SEVERAL FRONTAL WAVES AND THUS
OPPORTUNITIES FOR SHOWERS AND THUNDERSTORMS PRESENTING THEMSELVES
ACROSS CENTRAL INDIANA. THIS SOUTHWEST FLOW WILL ALSO ALLOW
TEMPERATURES TO BE SEASONABLY WARM FOR MUCH OF THE NEXT WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 352 PM EDT SUN APR 29 2012
FOCI FOR TONIGHT ARE POPS AND THUNDER CHANCES. MODELS ARE IN
GENERAL AGREEMENT ON LARGE SCALE FEATURES...BUT LEANED TOWARD NAM
AS OTHER MODELS APPEAR TO BE TOO WET BASED ON CURRENT TRENDS.
WARM FRONT SHOULD GRADUALLY PUSH NORTHWARD TONIGHT...AS A WEAK
SURFACE LOW MOVES OUT OF THE CENTRAL PLAINS. MOST GUIDANCE
APPEARED A BIT TOO AGGRESSIVE ON PRECIP WHEN MUCH OF THE
CONVECTION TO OUR WEST HAS STRUGGLED TO MAKE IT EASTWARD TODAY.
RAPID REFRESH AND RUC DEPICT BEST CHANCES OF PRECIP TONIGHT ACROSS
OUR NORTHWEST...AND CONSENSUS APPROACH TEMPERED SLIGHTLY DEPICTS
THIS WELL. INSTABILITY IS THERE BUT MINIMAL...AND BASED ON SREF
THUNDER PROBS HAVE GONE WITH ISOLATED THUNDER MENTION RATHER THAN
STRAIGHT THUNDERSTORM FORECAST. DID GO WITH CHANCE THUNDER IN THE
NORTHWEST LATE WHERE PROBABILTIES ARE A BIT HIGHER.
CONSENSUS APPROACH ON TEMPS AGREES WELL WITH UPSTREAM MINS FROM
LAST NIGHT...AND WILL STICK CLOSE TO THIS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
ISSUED AT 352 PM EDT SUN APR 29 2012
FOCUS REMAINS PRECIP CHANCES THROUGHOUT...WITH BOUNDARY REMAINING
IN THE AREA IN ONE FORM OR ANOTHER AND ONE OR MORE VERY SUBTLE
WAVES PERHAPS AIDING SHOWER AND THUNDERSTORM DEVELOPMENT. POPS
APPEARED A BIT HIGH IN PLACES...BUT NOT BY MUCH...GIVEN THE LACK
OF SIGNIFICANT UPPER LEVEL SUPPORT THROUGH THE FIRST PART OF THE
WEEK. HOWEVER...EXPECT THAT MESOSCALE INFLUENCES WILL HELP MAKE UP
FOR THIS. LEANED HEAVILY ON SREF THUNDER PROBS AND BOUNDARY
POSITION FOR DELINEATING BETWEEN WHERE TO FORECAST STRAIGHT
THUNDERSTORMS AND WHERE TO GO MORE SHOWERS WITH ISOLATED THUNDER
MENTION.
SLIGHT RISK FOR TOMORROW AND SEE TEXT FOR TUESDAY APPEAR
REASONABLE BASED ON MODEL CAPE/SHEAR PROFILES. IN SOMEWHAT TYPICAL
FASHION...AFTERNOON AND EARLY EVENING WOULD BE PREFERRED TIMES FOR
SEVERE BOTH DAYS.
ON TEMPS...GENERALLY A CONSENSUS APPROACH LOOKED OK...EXCEPT IT
APPEARED TO BE A FEW DEGREES COOL IN MOST PERIODS BASED ON LOW
LEVEL THICKNESSES. MINOR TWEAKS UPWARD WERE REQUIRED.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
ISSUED AT 230 PM EDT SUN APR 29 2012
ECMWF AND GFS HINT AT A LINGERING FRONTAL BOUNDARY AND NUMEROUS
WEAK SHORT WAVES PUSHING THROUGH THE OHIO VALLEY THROUGH THE FIRST
PART OF THE WEEKEND. CONFIDENCE IN THESE FEATURES IS
LOW...ALTHOUGH GIVEN THE PATTERN...LOW CHANCE POPS WILL BE NEEDED
THROUGH MUCH OF THE WORK WEEK. ALL BLEND HANDLES THIS RATHER WELL.
BY NEXT SUNDAY...THE ECMWF IS SIGNALING A CHANGE AS HIGH PRESSURE
BUILDS ACROSS THE GREAT LAKES...PUSH THE FRONTAL BOUNDARY SOUTH.
FOR NOW THIS WILL BE THE MAIN PERIOD WHERE WE WILL BE ABLE TO
REMOVE THE POPS.
THE SOUTHERLY FLOW EXPECTED THROUGH THE PERIOD ALONG WITH SHOULD
PROVIDE ABOVE NORMAL TEMPERATURES THROUGH MUCH OF THE WEEK.
&&
.AVIATION /DISCUSSION FOR THE 292100Z KIND TAF UPDATE/...
ISSUED AT 425 PM EDT SUN APR 29 2012
APPEARS MOST OF THE VFR CEILINGS AROUND 040 HAVE DISSIPATED...SO
WILL RAISE THE FORECAST CEILING TO ABOVE 050 FOR THE REST OF THE
AFTERNOON/EARLY EVENING.
SHORT TERM MODEL DATA SUGGEST THE SOUTHEAST FRINGES OF UPPER
DISTURBANCE CURRENTLY PASSING ACROSS ILLINOIS WILL BEGIN MOVING INTO
THE KIND VICINITY AFTER ABOUT 292300Z. LITTLE SURFACE INSTABILITY
EXISTS...BUT THERE IS SOME ELEVATED INSTABILITY. SO FAR...NOT SEEING
ANY INDICATIONS OF DEVELOPMENT...SO WILL CONTINUE TO LEAVE OUT OF
THE FORECAST AT THIS TIME. PREVIOUS DISCUSSION FOLLOWS.
VFR CONDITIONS ARE EXPECTED TO DETERIORATE LATE IN THE FORECAST
PERIOD TO MVFR.
WAVE SHORT WAVE EXITING THE AREA CONTINUES TO INDICATE DIMINISHING
RADAR RETURNS EARLY THIS AFTERNOON. EXPECT THIS TREND TO
CONTINUE...BUT WILL CARRY SOME VCSH AT IND AND LAF FOR THE FIRST
FEW HOURS. DYING SYSTEM OVER WESTERN ILLINOIS IS EXPECTED TO
PROPAGATE NORTHEAST...BUT ONCE AGAIN DIMINISH NORTH OF THE COLD
FRONT. THUS VFR WILL CONTINUE.
SEVERAL QUICK MOVING SHORT WAVE ARE EXPECTED TO PUSH ACROSS
INDIANA THROUGH THE TAF PERIOD AS A WARM FRONT IS EXPECTED TO PUSH
NORTH ACROSS THE TAF SITES STARTING DURING THE OVERNIGHT HOURS AND
CONTINUING AFTER 12Z MONDAY. CONFIDENCE FOR PRECISE TIMING OF
SPECIFIC PRECIPITATION EVENTS IS LOW...THUS FOR NOW HAVE PAINTED
LARGE WINDOWS OF VCSH DURING THE FRONTAL PASSAGE LATE TONIGHT AND
ON MONDAY MORNING. THUNDERSTORMS WILL BE POSSIBLE WITH THE PASSAGE
OF THIS SYSTEM...BUT WILL LEAVE OUT OF THE TAFS FOR NOW AS PRECISE
TIMING AT SPECIFIC POINTS IS NOT CLEAR.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD
SHORT TERM...NIELD
LONG TERM....PUMA
AVIATION...JP/JAS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
352 PM EDT SUN APR 29 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN
UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 352 PM EDT SUN APR 29 2012
A BROAD QUASI ZONAL TO SOUTHWEST FLOW WILL MAINTAIN ITSELF OVER
MOST OF THE NEXT WEEK...WITH SEVERAL FRONTAL WAVES AND THUS
OPPORTUNITIES FOR SHOWERS AND THUNDERSTORMS PRESENTING THEMSELVES
ACROSS CENTRAL INDIANA. THIS SOUTHWEST FLOW WILL ALSO ALLOW
TEMPERATURES TO BE SEASONABLY WARM FOR MUCH OF THE NEXT WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 352 PM EDT SUN APR 29 2012
FOCI FOR TONIGHT ARE POPS AND THUNDER CHANCES. MODELS ARE IN
GENERAL AGREEMENT ON LARGE SCALE FEATURES...BUT LEANED TOWARD NAM
AS OTHER MODELS APPEAR TO BE TOO WET BASED ON CURRENT TRENDS.
WARM FRONT SHOULD GRADUALLY PUSH NORTHWARD TONIGHT...AS A WEAK
SURFACE LOW MOVES OUT OF THE CENTRAL PLAINS. MOST GUIDANCE
APPEARED A BIT TOO AGGRESSIVE ON PRECIP WHEN MUCH OF THE
CONVECTION TO OUR WEST HAS STRUGGLED TO MAKE IT EASTWARD TODAY.
RAPID REFRESH AND RUC DEPICT BEST CHANCES OF PRECIP TONIGHT ACROSS
OUR NORTHWEST...AND CONSENSUS APPROACH TEMPERED SLIGHTLY DEPICTS
THIS WELL. INSTABILITY IS THERE BUT MINIMAL...AND BASED ON SREF
THUNDER PROBS HAVE GONE WITH ISOLATED THUNDER MENTION RATHER THAN
STRAIGHT THUNDERSTORM FORECAST. DID GO WITH CHANCE THUNDER IN THE
NORTHWEST LATE WHERE PROBABILTIES ARE A BIT HIGHER.
CONSENSUS APPROACH ON TEMPS AGREES WELL WITH UPSTREAM MINS FROM
LAST NIGHT...AND WILL STICK CLOSE TO THIS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
ISSUED AT 352 PM EDT SUN APR 29 2012
FOCUS REMAINS PRECIP CHANCES THROUGHOUT...WITH BOUNDARY REMAINING
IN THE AREA IN ONE FORM OR ANOTHER AND ONE OR MORE VERY SUBTLE
WAVES PERHAPS AIDING SHOWER AND THUNDERSTORM DEVELOPMENT. POPS
APPEARED A BIT HIGH IN PLACES...BUT NOT BY MUCH...GIVEN THE LACK
OF SIGNIFICANT UPPER LEVEL SUPPORT THROUGH THE FIRST PART OF THE
WEEK. HOWEVER...EXPECT THAT MESOSCALE INFLUENCES WILL HELP MAKE UP
FOR THIS. LEANED HEAVILY ON SREF THUNDER PROBS AND BOUNDARY
POSITION FOR DELINEATING BETWEEN WHERE TO FORECAST STRAIGHT
THUNDERSTORMS AND WHERE TO GO MORE SHOWERS WITH ISOLATED THUNDER
MENTION.
SLIGHT RISK FOR TOMORROW AND SEE TEXT FOR TUESDAY APPEAR
REASONABLE BASED ON MODEL CAPE/SHEAR PROFILES. IN SOMEWHAT TYPICAL
FASHION...AFTERNOON AND EARLY EVENING WOULD BE PREFERRED TIMES FOR
SEVERE BOTH DAYS.
ON TEMPS...GENERALLY A CONSENSUS APPROACH LOOKED OK...EXCEPT IT
APPEARED TO BE A FEW DEGREES COOL IN MOST PERIODS BASED ON LOW
LEVEL THICKNESSES. MINOR TWEAKS UPWARD WERE REQUIRED.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
ISSUED AT 230 PM EDT SUN APR 29 2012
ECMWF AND GFS HINT AT A LINGERING FRONTAL BOUNDARY AND NUMEROUS
WEAK SHORT WAVES PUSHING THROUGH THE OHIO VALLEY THROUGH THE FIRST
PART OF THE WEEKEND. CONFIDENCE IN THESE FEATURES IS
LOW...ALTHOUGH GIVEN THE PATTERN...LOW CHANCE POPS WILL BE NEEDED
THROUGH MUCH OF THE WORK WEEK. ALL BLEND HANDLES THIS RATHER WELL.
BY NEXT SUNDAY...THE ECMWF IS SIGNALING A CHANGE AS HIGH PRESSURE
BUILDS ACROSS THE GREAT LAKES...PUSH THE FRONTAL BOUNDARY SOUTH.
FOR NOW THIS WILL BE THE MAIN PERIOD WHERE WE WILL BE ABLE TO
REMOVE THE POPS.
THE SOUTHERLY FLOW EXPECTED THROUGH THE PERIOD ALONG WITH SHOULD
PROVIDE ABOVE NORMAL TEMPERATURES THROUGH MUCH OF THE WEEK.
&&
.AVIATION /DISCUSSION FOR THE 291800Z TAFS/...
ISSUED AT 1255 PM EDT SUN APR 29 2012
VFR CONDITIONS ARE EXPECTED TO DETERIORATE LATE IN THE FORECAST
PERIOD TO MVFR.
WAVE SHORT WAVE EXITING THE AREA CONTINUES TO INDICATE DIMINISHING
RADAR RETURNS EARLY THIS AFTERNOON. EXPECT THIS TREND TO
CONTINUE...BUT WILL CARRY SOME VCSH AT IND AND LAF FOR THE FIRST
FEW HOURS. DYING SYSTEM OVER WESTERN ILLINOIS IS EXPECTED TO
PROPAGATE NORTHEAST...BUT ONCE AGAIN DIMINISH NORTH OF THE COLD
FRONT. THUS VFR WILL CONTINUE.
SEVERAL QUICK MOVING SHORT WAVE ARE EXPECTED TO PUSH ACROSS
INDIANA THROUGH THE TAF PERIOD AS A WARM FRONT IS EXPECTED TO PUSH
NORTH ACROSS THE TAF SITES STARTING DURING THE OVERNIGHT HOURS AND
CONTINUING AFTER 12Z MONDAY. CONFIDENCE FOR PRECISE TIMING OF
SPECIFIC PRECIPITATION EVENTS IS LOW...THUS FOR NOW HAVE PAINTED
LARGE WINDOWS OF VCSH DURING THE FRONTAL PASSAGE LATE TONIGHT AND
ON MONDAY MORNING. THUNDERSTORMS WILL BE POSSIBLE WITH THE PASSAGE
OF THIS SYSTEM...BUT WILL LEAVE OUT OF THE TAFS FOR NOW AS PRECISE
TIMING AT SPECIFIC POINTS IS NOT CLEAR.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD
SHORT TERM...NIELD
LONG TERM....PUMA
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS DES MOINES IA
335 PM CDT SUN APR 29 2012
.SHORT TERM /TONIGHT/...
FORECAST CONCERNS CENTER AROUND CHANCE FOR LINGERING PRECIPITATION
TONIGHT. LARGE AREA OF PRECIP CONTINUES TO PUSH NORTH THROUGH THE
CWA...AND LINES UP WELL WITH ISENTROPIC LIFT AREA ON THE RUC 290K
SURFACE. HAVE TRENDED POPS TO CORRELATE WITH THIS AREA OF LIFT
TRANSLATING NORTH TO NORTHEASTWARD WITH TIME OVER THE NEXT 3 TO 6
HOURS. DEEPER SATURATION ENDS BY MID EVENING...WITH SOME DRIER AIR
MOVING IN ALOFT...WITH LOWEST LAYERS REMAINING SATURATED. SOME WEAK
ISENTROPIC LIFT STILL AROUND IN AREAS WITH THE MORE SHALLOW
SATURATION...THEREFORE HAVE ALSO MENTIONED SOME PATCHY DRIZZLE FOR
THE EVENING HOURS. ANY ELEVATED INSTABILITY CONFINED TO THE SOUTHERN
PORTION OF THE CWA...BUT HAS NOT MATERIALIZED MUCH EVEN THIS
AFTERNOON...SO ONLY HAVE SOME ISOLATED THUNDER MENTION ACROSS FAR
SOUTH FOR THIS EVENING. WITH THE SHALLOW LOW LEVEL
SATURATION...EXPECT STRATUS TO CONTINUE THROUGH THE NIGHT. WITH
WINDS EXPECTED TO BECOME LIGHT AND VARIABLE AS WEAK HIGH PRESSURE
BUILDS INTO THE STATE...SHALLOW MOISTURE AND RESIDUAL SURFACE
MOISTURE FROM THE RAINFALL COULD ALSO HAVE AREAS OF FOG POSSIBLY
DENSE FORM ACROSS THE CWA BY LATE EVENING INTO THE OVERNIGHT HOURS.
FOR NOW JUST MENTIONED THE FOG IN THE GRIDS...BUT WILL HAVE TO
MONITOR ITS DEVELOPMENT TO DETERMINE IF IT WILL BECOME DENSE.
OVERALL EXPECT PRECIP TO CLEAR FASTER THAN IN PREVIOUS
FORECASTS...SO HAVE ENDED ANY PRECIPITATION BY LATE EVENING AND HAVE
GONE DRY IN THE LATE NIGHT HOURS.
.LONG TERM /MONDAY THROUGH SUNDAY/...
WITH SYSTEM MOVING A BIT FASTER...MON SHOULD BE A DRY DAY AND LIKELY
THE ONLY FULLY DRY PERIOD OF THE FORECAST. BROAD SOUTHWEST FLOW
WILL PERSIST OVER THE CENTRAL U.S. FOR THE NEXT WEEK WITH A SERIES
OF UPPER LEVEL SYSTEM S LIFTING NEWD OUT OF THE SOUTHWEST U.S.
TIMING WILL BE TRICKY...BUT IT DOES APPEAR THERE WILL BE SOME RAIN
DURING EACH OF THE 12 HOUR PERIODS OF THE FORECAST...THOUGH NOT ALL
OF IT. THERE WILL BE INTERMITTENT CHANCES FOR SEVERE WEATHER WITH
THE BEST CHANCES LOOKING LIKE TUE NIGHT AND FRIDAY NIGHT RIGHT NOW.
SOME CAPPING IS BEGINNING TO TAKE PLACE WHICH WILL CUT DOWN THE
SEVERE POTENTIAL SOME. ALL IN ALL IT DOES LOOK LIKE A DECENT AMOUNT
OF RAIN DURING THE NEXT WEEK. NOT SURE THE HEAVIEST WILL BE IN THE
DRIEST AREAS HOWEVER. THE THE DRY NWRN ZONES WILL GET ABOVE NORMAL
RAINFALL THIS WEEK. TEMPS WILL WARM ABOVE NORMAL ON MONDAY AND
REMAIN THAT WAY THROUGH THE WEEK.
&&
.AVIATION...29/18Z
LOW STRATUS EXPECTED TO REMAIN ACROSS THE CWA TODAY...AND BUILD INTO
KALO AND KMCW THROUGH THE AFTERNOON AS AREA OF SHOWERS WITH A FEW
ISOLATED THUNDERSTORMS CONTINUES TO SPREAD NORTHWARD ACROSS THE CWA.
RAIN AREA TO MOVE NORTH NORTHEASTWARD THROUGH THE AFTERNOON...AND
TAPER OFF FROM SOUTHWEST TO NORTHEAST THIS EVENING. WINDS DIMINISH
AND WILL BE VARIABLE LATE TONIGHT WITH AN AREA OF SFC HIGH PRESSURE
BUILDING INTO THE CWA. WITH THE RAIN TODAY...EXPECT AREA OF LOW
STRATUS TO CONTINUE THROUGH THE NIGHT...POSSIBLY LOWERING INTO
LIFR/IFR CIGS. ALSO EXPECT FOG WITH HIGH RESIDUAL SFC MOISTURE...SO
HAVE DROPPED VSBYS INTO THE LIFR/IFR CATEGORY AT ALL TAF SITES BY
LATE EVENING INTO THE OVERNIGHT HOURS.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...MJB
LONG TERM...MS APR 12
AVIATION...MJB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
612 PM MDT MON APR 30 2012
.UPDATE...
ISSUED AT 602 PM MDT MON APR 30 2012
MAIN CHANGE WAS TO REMOVE MENTION OF PRECIP. CHANCES FOR THE LATE
AFTERNOON/EVENING HOURS...BASED ON LATEST WATER VAPOR IMAGERY
SHOWING A DRY SLOT OVER THE EASTERN PART OF THE AREA WHERE STORM
WERE MOST LIKELY TO FORM. ALSO INCREASED CLOUD COVER BASED ON
LATEST SATELLITE SHOWING AN AREA OF CLOUDS WEST OF THE AREA AHEAD
OF THE NEXT UPPER LEVEL TROUGH.
&&
.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 301 PM MDT MON APR 30 2012
CURRENTLY A DRY LINE RESIDES OVER EASTERN COLORADO WITH A S/W TROUGH
MOVING ACROSS THE ROCKIES INTO EASTERN COLORADO. INSTABILITY WAS
INCREASING EAST OF THE DRY LINE AND DEW POINTS WERE ALSO SLOWLY
INCREASING WITH MID 50 DEW POINTS OVER HILL CITY AND NORTON AREAS. AS
THE TROUGH MOVES CLOSER...ISOLATED THUNDERSTORMS ARE EXPECTED TO
DEVELOP EAST OF THE DRY LINE...ROUGHLY IN THE EASTERN HALF OF THE
CWA. THUNDERSTORMS WILL MOVE EAST OUT OF THE CWA THIS EVENING.
TOWARDS TUESDAY MORNING...WITH THE RECENT PRECIPITATION AND
DEW POINTS IN THE 50S...FOG WILL ONCE AGAIN DEVELOP OVER MOST OF THE
AREA.
.LONG TERM...(TUESDAY THROUGH MONDAY)
ISSUED AT 301 PM MDT MON APR 30 2012
TUESDAY-TUESDAY NIGHT...FOG POTENTIAL WILL BE INITIAL CONCERN FOR
THE PERIOD AS LEE TROUGH DEVELOPS THROUGH THE MORNING HOURS. WHILE
MOISTURE PROFILES OVERNIGHT ARE SUPPORTIVE OF FOG IN AREAS WHERE
WINDS DECOUPLE...FLOW JUST OFF THE SFC SHIFT TO THE WEST FAIRLY
QUICKLY BTWN 12 AND 15Z RESULTING IN A SHRINKING AREA WITH
INCREASING OR CONSTANT HYDROLAPSE RATES. DON`T THINK I CAN RULE
OUT FOG FOR A BRIEF PERIOD DURING THE MORNING HOURS...BUT GIVEN
ABOVE SCENARIO THINK IT WILL CLEAR PRETTY QUICKLY FROM WEST TO
EAST WHICH IS SUPPORTED BY SREF PROBABILISTIC OUTPUT. OTHERWISE
ATTENTION WILL THEN TURN TO POTENTIAL FOR ANY AFTERNOON/EARLY
EVENING CONVECTION AS DRY LINE MOVES ACROSS THE AREA. WITH MOISTURE
PROFILES REMAINING FAIRLY SHALLOW AND ONLY WEAK PRESSURE FALLS
ACROSS THE WESTERN CWA EXPECT DRY LINE/INSTABILITY TO MIX QUICKLY
TO THE EAST AND AS A RESULT DO NOT ANTICIPATE MUCH OF A
THUNDERSTORM THREAT THROUGH THE DAY AND HAVE ADJUSTED
PROBABILITIES DOWN ACCORDINGLY. OVERNIGHT PRECIPITATION THREAT
BECOMES A LITTLE MORE UNCERTAIN AS H85 LOW DEVELOPS OVER THE AREA
AND GRADUALLY LIFTS TO THE NORTH OF THE AREA. NAM...WHICH IS
SUPPORTED BY SREF PLUME CLUSTERS SUGGEST MUCAPES INCREASE IN THE
EASTERN CWA AS H85 MOISTURE AXIS BACKS INTO THE AREA. WITH LARGE
SCALE FORCING INCREASING AHEAD H85 LOW AND STRONG CONVERGENCE
ALONG 50KT LLJ COULD SEE A FEW ELEVATED STORMS DEVELOP ACROSS THE
EASTERN CWA DURING THE OVERNIGHT HOURS. OTHER CONCERN FOR THE
PERIOD WILL BE FIRE WEATHER POTENTIAL AS TEMPS WARM INTO THE UPPER
80S AND LOW 90S BEHIND DRY LINE AND AFTERNOON HUMIDITIES FALL TO
AROUND 10 PERCENT. MAIN CONCERN AT THIS POINT IN THE SEASON IS
FUELS AS GREEN UP WELL UNDERWAY AT SEVERAL LOCATIONS...BUT STILL
HAVE LOCATIONS REPORTING CRITICAL FUEL CONDITIONS. AFTER LOOKING
THROUGH AVAILABLE RELATIVE GREENNESS DATA...LOOKS LIKE THERE
REMAINS A FEW AREAS OF CURED FUELS ACROSS THE WEST CENTRAL PORTION
OF THE CWA. WHILE WEATHER CONDITIONS WILL BE NEAR CRITICAL VALUES
ALONG AND SOUTH OF INTERSTATE 70...SATELLITE DERIVED GREENNESS
VALUES SUGGEST THAT MUCH OF THIS AREA IS WELL INTO GREEN UP.
WEDNESDAY-THURSDAY...CWA WILL REMAIN ON SOUTHERN PERIPHERY OF BROAD
TROUGHING ACROSS THE NORTHWEST CONUS...WITH A SERIES OF WEAK SHORT
WAVE TROUGHS MOVING THROUGH THE FLOW CAUSING A FEW PERIODS OF
CYCLOGENESIS AS THESE DISTURBANCES INTERACT WITH FRONTAL ZONE THAT
SLIDES ACROSS THE AREA OVERNIGHT WEDNESDAY. WITH FRONT IN AND AROUND
THE AREA THINK THERE WILL BE A FEW CHANCES FOR THUNDERSTORMS DURING
THE PERIOD...BUT THINK BEST CHANCES WILL BE OVERNIGHT WEDNESDAY AS
COLD FRONT SWEEPS ACROSS THE AREA AND LARGE SCALE ASCENT WITH SHORT
WAVE TROUGH AND STRONG FRONTOGENESIS COINCIDE. EXPECT HIGHS TO BE
SIMILAR IF NOT SLIGHTLY COOLER THAN TUESDAY ACROSS THE AREA...WITH
TEMPERATURES POTENTIALLY COOLING BY AS MUCH AS 10 DEGREES ON
WEDNESDAY. GIVEN EXPECTED PATTERN...COOLER TEMPS DO LOOK IN ORDER
AND AM A LITTLE CONCERNED THAT SEVERAL SREF MEMBERS COMING IN MUCH
COLDER THAN MEAN VALUES. HAVE TRENDED DOWN TEMPS SEVERAL DEGREES BUT
WANT TO SEE IF OPERATIONAL MODELS LATCH ON TO COLDER SOLUTION BEFORE
DRASTICALLY DROPPING TEMPERATURES.
FRIDAY-MONDAY...MEDIUM RANGE MODELS AND 12Z GEFS DATA COMING INTO
BETTER AGREEMENT WITH PATTERN DEVELOPMENT FOR THE COMING WEEKEND
WITH LARGE TROUGH EXPECTED TO BECOME ESTABLISHED OVER THE ROCKIES
SATURDAY AND SUNDAY LEADING TO A PERIOD OF POTENTIALLY ACTIVE
WEATHER ACROSS THE PLAINS WITH FRONTAL ZONE DRAPED OVER THE AREA AND
STRONG SOUTHWESTERLY FLOW ALOFT. GIVEN THE PATTERN...THINK
INCREASING PRECIP POTENTIAL WARRANTED AND WELL SUPPORTED BY GEFS
PROBABILISTIC OUTPUT WITH PRECIP CHANCES IN THE 30-50% RANGE BY THE
END OF THE FORECAST PERIOD. TEMPERATURES WILL BE A BIT TRICKIER AS
LARGE DIFFERENCES EXIST WITH RESPECT TO EXACT POSITION OF
FRONT...RESULTING IN LARGE DIFFERENCES IN SFC FIELDS. ENSEMBLE
SPREADS REALLY SHOWING THIS AS WELL...WITH STD DEVIATIONS
APPROACHING 10 DEGREES BY SUNDAY. GIVEN THESE LARGE SPREADS...HARD
TO DEVIATE MUCH FROM MEAN VALUES AT THIS POINT AS THERE DOES NOT
APPEAR TO BE A STRONGLY PREFERRED SOLUTION IN THE ENSEMBLE DATA AT
THIS TIME.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 602 PM MDT MON APR 30 2012
VFR TO LIFR CONDITIONS ARE FORECAST FOR THE 0Z TAFS. MODELS
DISAGREE AS TO WHEN THE FOG/LOW CLOUDS WILL DEVELOP FOR THE SITES.
RUC IS THE EARLIEST...STARTING AROUND 4Z WHILE THE NAM IS THE
LATEST AT 9Z. WITH HRRR STARTING AROUND 5Z...DECIDED TO COMPROMISE
WITH A START TIME OF 7Z...WHICH SEEMS TYPICAL FOR MOST FOG EVENTS.
BUFKIT SOUNDINGS WERE INDICATING MORE OF A STRATUS EVENT OVERNIGHT
THAN FOG...BUT WITH SOUNDINGS SATURATING TO THE SURFACE...DECIDED
TO CONTINUE THE MENTION OF FOG. AM THINKING LOWEST CONDITIONS WILL
BE AROUND 9 OR 10Z...LASTING UNTIL AFTER SUNRISE BEFORE IMPROVING.
&&
.FIRE WEATHER...
ISSUED AT 301 PM MDT MON APR 30 2012
AFTERNOON HUMIDITIES WILL FALL TO AROUND 10 PERCENT TOMORROW
AFTERNOON BEHIND DRY LINE WITH WESTERLY WINDS AROUND 15 MPH GUSTING
TO 25 MPH. THESE CONDITIONS WILL GENERALLY OCCUR SOUTH OF A
FLAGLER TO HILL CITY LINE...BUT WITH RELATIVE GREENNESS SATELLITE
PRODUCTS SUGGEST FUELS ACROSS MUCH OF THIS AREA NO LONGER CURED.
FOR THIS REASON...WILL ONLY ISSUE FIRE WEATHER WATCH FOR SMALL
AREA WHERE POTENTIAL FOR SIGNIFICANT AMOUNTS OF CURED FUELS EXIST.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...FIRE WEATHER WATCH TUESDAY AFTERNOON FOR KSZ013-027.
CO...FIRE WEATHER WATCH TUESDAY AFTERNOON FOR COZ253-254.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...BAS
LONG TERM...JRM
AVIATION...JTL
FIRE WEATHER...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
757 AM MDT SUN APR 29 2012
.UPDATE...
ISSUED AT 742 AM MDT SUN APR 29 2012
MADE A FEW QUICK UPDATES TO THE FORECAST...MAINLY TO ACCOUNT FOR A
FARTHER WESTWARD EXTENT OF FOG AS SOME MINOR VISIBILITY
RESTRICTIONS OBSERVED AS FAR WEST AS OBERLIN AND MCCOOK.
WATER VAPOR IMAGERY/RUC PV ANALYSIS INDICATING TWO SEPARATE SHORT
WAVE TROUGHS APPROACHING THE AREA...ONE ALONG THE WESTERN COLORADO
BORDER AND THE SECOND ALONG THE SOUTHEAST CO BORDER. WHILE THERE
HAS BEEN A LULL IN PRECIPITATION ACROSS THE AREA...INCREASE IN WEAK
ECHOES ACROSS THE NORTHERN CWA SUPPORTS INCREASED ASCENT WITH THIS
APPROACHING FIRST TROUGH...AND HAVE FINE TUNED POPS OVER THE NEXT
2-3 HOURS TO FOCUS MORE IN THE NORTHERN CWA AS PER LAST FEW RUNS
OF RUC WHICH SEEMS TO BE SUPPORTED BY LATEST TRENDS...ALTHOUGH
CANNOT RULE OUT AN ISOLATED SHOWER FARTHER SOUTH/EAST WITH INITIAL
TROUGH.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 300 AM MDT SUN APR 29 2012
SHOWERS AND PERHAPS A THUNDERSTORM POSSIBLE THIS MORNING AS A
WEATHER DISTURBANCE LIFTS NORTH OF THE INTERSTATE. A MORE VIGOROUS
DISTURBANCE MOVES IN FROM THE SOUTHWEST LATE IN THE DAY BRINGING
AN INCREASE IN THUNDERSTORMS THROUGH MID EVENING...SOME OF WHICH
MAY BECOME SEVERE. THIS DISTURBANCE WILL EXIT TO THE EAST OF THE
AREA LATE TONIGHT THROUGH MONDAY WITH A DOWNWARD TREND IN
PRECIPITATION CHANCES.
HIGH TEMPERATURES TODAY IN THE 60S WITH LOW TO MID 70S MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 300 AM MDT SUN APR 29 2012
MONDAY NIGHT-TUESDAY...MAY SEE A THUNDERSTORM OR TWO ACROSS THE FAR
EASTERN 1/4 OF THE AREA OTHERWISE MUCH WARMER WITH AFTERNOON HIGHS
IN THE LOW 80S IN FAR EASTERN COLORADO...MID 80S EAST OF THE CO/KS
BORDER.
WEDNESDAY THROUGH SATURDAY...NOT TOO MUCH CHANGE IN WHAT THE MODELS
WERE SHOWING FROM 24 HOURS AGO. BEGINNING OF THE PERIOD STARTS OUT
IN A FAST NEARLY ZONAL FLOW. ON FRIDAY AN UPPER LEVEL RIDGE BUILDS
INTO THE AREA FOLLOWED BY A STRONGER SOUTHWESTERLY FLOW THAN WHAT
OCCURRED EARLIER IN THE PERIOD. MODELS AND ENSEMBLES ARE A LITTLE
BETTER THAN WHAT THEY SHOWED YESTERDAY BUT THERE ARE STILL SOME
DIFFERENCES ALOFT...ESPECIALLY TOWARD THE END OF THE PERIOD.
AS SAID YESTERDAY...HARD TO GET TOO DEFINITE ABOUT PRECIPITATION
CHANCES WITH THE SMALL SCALE WAVES EMBEDDED WITHIN THIS FLOW.
HOWEVER AS IT LOOKS NOW WITH THE BUILDING RIDGE INTO THE AREA
...FRIDAY DEFINITELY LOOKS THE DRIEST. OTHERWISE...LOW CHANCES OF
PRECIPITATION WILL EXIST NEARLY EVERY DAY WITH BETTER CHANCES
POSSIBLE AT THE END OR JUST BEYOND THIS PERIOD. TEMPERATURES WILL BE
ABOVE NORMAL WITH FRIDAY AND SATURDAY HAVING THE POTENTIAL TO BE
WARMER THAN WHAT IS IN THERE DUE TO THE STRONG RIDGING AND DEEP
SOUTHWESTERLY FLOW ALOFT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 300 AM MDT SUN APR 29 2012
FOR KGLD...VFR EXPECTED. MAY HAVE A FEW SHOWERS NEAR THE TERMINAL
AROUND 15Z-20Z WITH THUNDERSTORMS EXPECTED AROUND 00Z CONTINUING
THROUGH 04Z OR SO. SHOULD A THUNDERSTORM DIRECTLY IMPACT THE
TERMINAL VIS AND/OR CIG MAY DROP INTO MVFR RANGE. AFTER 06Z CIGS
AND VIS EXPECTED TO LOWER INTO MVFR/IFR RANGE AS LOW LEVELS
SATURATE AND FOG DEVELOPS.
FOR KMCK LIGHT PRECIPITATION POSSIBLE AFTER 21Z WITH THUNDERSTORMS
POSSIBLE EARLY EVENING INTO THE OVERNIGHT HOURS. FOG WILL ALSO
DEVELOP AFTER 06Z OR SO WHERE MVFR/IFR CIGS/VIS POSSIBLE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...007
LONG TERM...007/BULLER
AVIATION...007
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
314 AM CDT SUN APR 29 2012
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 310 AM CDT SUN APR 29 2012
AN UPPER LEVEL LOW OVER THE DAKOTAS WILL PUSH NORTH INTO CANADA
WHILE THE BASE OF THE ASSOCIATED UPPER TROUGH PUSHES INTO THE
CENTRAL PLAINS. FIRST A RIGHT REAR QUAD OF AN UPPER JET MOVES ACROSS
SOUTHWEST KANSAS THIS MORNING. ANOTHER JET MOVES ACROSS ARIZONA INTO
THE TEXAS PANHANDLE THIS EVENING PUTTING THE LEFT FRONT QUAD ACROSS
FAR SOUTHWEST AND SOUTH CENTRAL KANSAS. ENHANCED LIFT ASSOCIATED
WITH THESE UPPER LEVEL FEATURES WILL ALLOW FOR MOISTURE TO BE
TRANSPORTED NORTHWARD INTO MUCH OF THE FA WITH WARM AIR ADVECTION
AND ISENTROPIC LIFT OVER THE COLD FRONT DRAPED ACROSS OKLAHOMA AND
THE TEXAS PANHANDLE. SHOWERS AND ISOLATED THUNDERSTORMS WILL
INCREASE THIS MORNING INTO THE AFTERNOON WITH SOME POSSIBLE SEVERE
THUNDERSTORMS AND HEAVY RAINFALL IN THE FAR SOUTHEAST AROUND
MEDICINE LODGE. WILL HAVE TO MONITOR FOR POSSIBLE FLOODING IN THE
SOUTHEAST FA WITH CONTINUED TRAINING OF THUNDERSTORMS WITH PRECIPITABLE
WATER OVER AN INCH INTO THE AFTERNOON AND EVENING. AS YOU GO
NORTH LIGHTER QPF AMOUNTS ARE FORECAST WITH LESS THAN ONE TENTH IN
THE FAR NORTH. POPS WILL RANGE FROM AROUND 40 FAR NORTH TO NEAR
100 PERCENT IN THE SOUTHEAST. COULD ALSO HAVE SOME HAIL UP TO
QUARTER SIZE IN THE SOUTHEAST FA WITH THE BEST INSTABILITY. CAPE
FIELDS INCREASE TO 1000 TO 1500 J/KG BY LATE AFTERNOON INTO THE
OVERNIGHT AS MORE MOISTURE MOVES INTO WESTERN KANSAS WITH A
CONTINUATION OF THUNDERSTORMS THROUGH THE NIGHT ESPECIALLY IN THE
SOUTHEAST FA WITH THE BEST JET DYNAMICS.
HIGHS TODAY ARE EXPECTED TO BE ONLY IN THE MID TO UPPER 60S WITH
LITTLE OR NO INSOLATION. OVERNIGHT LOWS WILL BE IN THE LOW TO MID
50S WITH AROUND 60 SOUTHEAST FA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 258 AM CDT SUN APR 29 2012
AN UPPER LEVEL LONG WAVE TROUGH WILL BE FOUND ACROSS THE ROCKIES AS
THE LONG TERM PERIOD BEGINS WITH A SERIES OF WEAK SHORTWAVES MOVING
ACROSS THE CENTRAL PLAINS. A JET STREAK WILL BE EXITING THE CENTRAL
PLAINS ON MONDAY AND PLACE SOUTHWEST KANSAS IN THE RIGHT ENTRANCE
REGION. THIS WILL ENHANCE LIFT ACROSS OUR AREA. A WEAK SURFACE LOW
WILL BE FOUND ACROSS FAR WESTERN KANSAS IN THE MORNING WITH A
FRONTAL BOUNDARY EXTENDING EASTWARD ACROSS CENTRAL KANSAS. WINDS
WILL GENERALLY BE FROM THE SOUTH SOUTHEAST WHICH WILL CONTINUE TO
BRING AMPLE MOISTURE TO THE AREA. A DRYLINE WILL BE FOUND ACROSS THE
KS/CO BORDER IN THE MORNING THEN SHIFT EASTWARD AS THE DAY
PROGRESSES. THUNDERSTORMS ARE ANTICIPATED TO BLOSSOM DURING THE
AFTERNOON AT PEAK HEATING HOWEVER THERE ARE A FEW FACTORS THAT COULD
LIMIT DEVELOPMENT. THESE FACTORS CONSIST OF HOW THE AIRMASS WILL BE
MODIFIED BY THE EARLIER CONVECTION SUNDAY NIGHT INTO EARLY MONDAY
MORNING AND HOW MUCH CLEARING WILL OCCUR EARLY MONDAY AFTERNOON. IF
CLEARING DOES OCCUR CAPE VALUES COULD SOAR TO OVER 1500 J/KG IN THE
AFTERNOON. WITH SURFACE DEWPOINTS OVER 60 DEGREES AS WELL AS 40-50
KNOT 0-6 KM SHEAR A FEW STORMS COULD BECOME SEVERE WITH LARGE HAIL
AND DAMAGING WINDS BEING THE MAIN CONCERN. MODERATE DIRECTIONAL
SHEAR WILL ALSO BE FOUND IN THE LOWER LEVELS SO AN ISOLATED TORNADO
CAN CAN NOT BE RULED OUT WITH THESE STORMS. THUNDERSTORM CHANCES
CONTINUE OVERNIGHT ACROSS SOUTH CENTRAL AND CENTRAL KANSAS AS THE
LOW LEVEL JET STRENGTHENS. A FEW OF THESE STORMS COULD ALSO BECOME
SEVERE WITH LARGE HAIL BEING THE MAIN CONCERN. DEPENDING ON HOW MUCH
CLEARING IS SEEN DURING THE AFTERNOON, HIGHS ON MONDAY ARE
ANTICIPATED TO RANGE FROM THE MID 70S ACROSS THE I-70 CORRIDOR TO
AROUND 80 ACROSS THE KS/OK BORDER. LOWS TUESDAY MORNING ARE
ANTICIPATED TO RANGE FROM THE LOWER 50S ACROSS THE KS/CO BORDER TO
LOWER 60S ACROSS SOUTH CENTRAL KANSAS WHERE DEWPOINTS WILL BE AROUND
60 DEGREES.
LEE TROUGHING DEVELOPS ACROSS EASTERN COLORADO TUESDAY MORNING IN
RESPONSE TO THE NEXT UPPER LEVEL TROUGH MOVING THROUGH THE NORTHERN
ROCKIES. SOUTHERLY WINDS WILL INCREASE IN SPEED AND BRING ADDITIONAL
LOW LEVEL MOISTURE UP FROM THE SOUTH. THIS WILL ALSO CAUSE ANOTHER
DRYLINE TO FORM ACROSS EASTERN COLORADO. MODELS SUGGEST A COLD FRONT
TO MOVE SOUTH FROM THE DAKOTAS INTO NEBRASKA AND NORTHERN KANSAS BY
WEDNESDAY MORNING. THIS WILL SHIFT THE SURFACE TROUGH AND DRYLINE
FARTHER EAST. THE AFOREMENTIONED COLD FRONT IS FORECASTED TO MOVE
FARTHER SOUTH WEDNESDAY THEN STALL OUT ACROSS CENTRAL KANSAS IN THE
AFTERNOON. A SLIGHT CHANCE OF THUNDERSTORMS WILL BE POSSIBLE
WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING ALONG AND EAST OF THE
DRYLINE AND COLD FRONT. HIGHS TUESDAY THROUGH THURSDAY ARE
FORECASTED TO RISE INTO THE 80S WITH THE POSSIBILITY OF AROUND 90
DEGREES ACROSS FAR SOUTHWESTERN KANSAS. LOWS WEDNESDAY THROUGH
FRIDAY MORNING ARE EXPECTED TO RANGE FROM THE MID 50S ACROSS THE
KS/CO BORDER TO LOWER 60S ACROSS SOUTH CENTRAL AND CENTRAL KANSAS.
EXTENDED MODELS THEN SUGGEST UPPER LEVEL RIDGING DEVELOPING ACROSS
THE SOUTHERN ROCKIES FRIDAY INTO SATURDAY WITH A TROUGH OF LOW
PRESSURE ENTERING THE WESTERN CONUS. A WEAK AREA OF LOW PRESSURE IS
DEPICTED ACROSS THE TEXAS PANHANDLE DURING THIS TIMEFRAME WHICH WILL
CONTINUE SOUTHERLY WINDS ACROSS WESTERN KANSAS. NO PRECIPITATION IS
EXPECTED AT THIS TIME WITH PARTLY CLOUDY SKIES. HIGHS FRIDAY AND
SATURDAY ARE FORECASTED TO RISE INTO THE MID TO UPPER 80S WITH LOWS
AROUND 60 DEGREES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1234 AM CDT SUN APR 29 2012
VFR CONDITIONS WILL CONTINUE WITH SCATTERED SHOWERS AND
THUNDERSTORMS INCREASING IN COVERAGE AFTER 12 TO 14Z. EXPECT MVFR
CONDITIONS WITH THUNDERSTORMS. THE STORMS WILL BE ELEVATED, WITH A
SKINNY AREA OF CAPE, NORTH OF A COLD FRONT AND LASTING INTO 06Z.
THE RAINFALL INDUCED BY RR JET CIRCULATION AND A WEAK UPPER LEVEL
TROUGH.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 68 55 77 58 / 50 50 40 30
GCK 67 54 78 56 / 40 50 40 20
EHA 69 54 81 53 / 40 50 30 20
LBL 69 55 82 55 / 50 50 40 30
HYS 68 53 76 59 / 30 40 30 30
P28 71 59 78 62 / 70 70 40 40
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RUSSELL
SHORT TERM...KRUSE
LONG TERM...HOVORKA 42
AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
259 AM CDT SUN APR 29 2012
...UPDATED LONG TERM SECTION...
.SYNOPSIS...
ISSUED AT 359 PM CDT SAT APR 28 2012
THE NEXT 24 HOURS WILL BE A CHALLENGING FORECAST WITH CONVECTIVE
CHANCES HAVING AN IMPACT ON TEMPERATURES. ANY UPPER VORTEX IS
CURRENTLY SPINNING EASTWARD INTO THE NORTHERN PLAINS AS OBSERVED ON
INFRARED SATELLITE. TO THE SOUTH OF THIS LOW IS AN UPPER JET
STREAKING ACROSS THE CENTRAL AND SOUTHERN ROCKIES INTO THE HIGH
PLAINS REGION. IT HAS BEEN OBSERVED THAT EVEN WITH THE INCOMING NOSE
OF THE UPPER JET, NO CONVECTION HAS BEEN OBSERVED THROUGH THE
MOUNTAINS IN THE LIGHTNING DETECTION NETWORK PLOT. A STATIONARY
FRONT WAS DRAPED ACROSS CENTRAL AND WESTERN OKLAHOMA WITH HIGH
DEW POINTS IN THE MID 60S, WHILE BEHIND THE BOUNDARY LIGHT
NORTHEAST WINDS COVERED WESTERN KANSAS.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 359 PM CDT SAT APR 28 2012
THE COMBINATION OF MID LEVEL INSTABILITY AND UPPER FORCING WILL BE
THE MAJOR PLAYER IN ANY CONVECTIVE EVOLUTION OVER THE NEXT 24 TO 36
HOURS. AS THE UPPER WAVE APPROACHES TONIGHT, WESTERN KANSAS WILL BE
MORE IN CLOSE PROXIMITY OF AN UPPER RIGHT ENTRANCE JET REGION,
PROMOTING A THERMALLY INDIRECT CIRCULATION. THE PREEXISTING
ATMOSPHERE WILL BE CONDITIONALLY UNSTABLE SO CONVECTION IS POSSIBLE
INCREASING FROM THE WEST OVERNIGHT. THE HIGH RESOLUTION ARW AND NMM
MODELS AND THE NAM PRODUCE QPF IN THIS ZONE BETWEEN MIDNIGHT AND
12Z. MOVING INTO THE EARLY SUNDAY MORNING TIMEFRAME, THE UPPER
TROUGH AXIS WILL ROTATE CLOSER TO WESTERN KANSAS INCREASING THE
HEIGHT GRADIENT AND PVA WHILE THE MODELS BEGIN TO LIFT THE
STATIONARY FRONT ACROSS WESTERN OKLAHOMA CLOSER TO THE
OKLAHOMA/KANSAS LINE LATE SUNDAY. AS A RESULT, ADDITIONAL
THUNDERSTORM CHANCES ARE WARRANTED THROUGH THE DAY ON SUNDAY. NAM
MODEL SHOWS SBCAPES INCREASING IN EXCESS OF 1000 J/KG, ESPECIALLY
ACROSS THE SOUTHWEST/WESTERN AND SOUTHERN SECTIONS OF KANSAS.
AS THE UPPER JET AND TROUGH MOVES THROUGH THE AREA ON SUNDAY,
ADDITIONAL THUNDERSTORMS CHANCES ARE EXPECTED THROUGH THE DAY AS THE
ATMOSPHERE DESTABILIZES AGAIN DIURNALLY. THE POSITION OF THE FRONT
TO THE SOUTH WILL BE THE MAIN FOCUS FOR CONVECTION, ESPECIALLY
SEVERE CONVECTION. HOWEVER, FROM MODEL LOW LEVEL FIELDS, IT APPEARS
SOUTHWEST KANSAS WILL BE ON THE NORTH SIDE OF THE BOUNDARY, SO THE
SEVERE POTENTIAL COULD BE RELEGATED PRIMARILY TO HAIL AND WIND
THREATS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 258 AM CDT SUN APR 29 2012
AN UPPER LEVEL LONG WAVE TROUGH WILL BE FOUND ACROSS THE ROCKIES AS
THE LONG TERM PERIOD BEGINS WITH A SERIES OF WEAK SHORTWAVES MOVING
ACROSS THE CENTRAL PLAINS. A JET STREAK WILL BE EXITING THE CENTRAL
PLAINS ON MONDAY AND PLACE SOUTHWEST KANSAS IN THE RIGHT ENTRANCE
REGION. THIS WILL ENHANCE LIFT ACROSS OUR AREA. A WEAK SURFACE LOW
WILL BE FOUND ACROSS FAR WESTERN KANSAS IN THE MORNING WITH A
FRONTAL BOUNDARY EXTENDING EASTWARD ACROSS CENTRAL KANSAS. WINDS
WILL GENERALLY BE FROM THE SOUTH SOUTHEAST WHICH WILL CONTINUE TO
BRING AMPLE MOISTURE TO THE AREA. A DRYLINE WILL BE FOUND ACROSS THE
KS/CO BORDER IN THE MORNING THEN SHIFT EASTWARD AS THE DAY
PROGRESSES. THUNDERSTORMS ARE ANTICIPATED TO BLOSSOM DURING THE
AFTERNOON AT PEAK HEATING HOWEVER THERE ARE A FEW FACTORS THAT COULD
LIMIT DEVELOPMENT. THESE FACTORS CONSIST OF HOW THE AIRMASS WILL BE
MODIFIED BY THE EARLIER CONVECTION SUNDAY NIGHT INTO EARLY MONDAY
MORNING AND HOW MUCH CLEARING WILL OCCUR EARLY MONDAY AFTERNOON. IF
CLEARING DOES OCCUR CAPE VALUES COULD SOAR TO OVER 1500 J/KG IN THE
AFTERNOON. WITH SURFACE DEWPOINTS OVER 60 DEGREES AS WELL AS 40-50
KNOT 0-6 KM SHEAR A FEW STORMS COULD BECOME SEVERE WITH LARGE HAIL
AND DAMAGING WINDS BEING THE MAIN CONCERN. MODERATE DIRECTIONAL
SHEAR WILL ALSO BE FOUND IN THE LOWER LEVELS SO AN ISOLATED TORNADO
CAN CAN NOT BE RULED OUT WITH THESE STORMS. THUNDERSTORM CHANCES
CONTINUE OVERNIGHT ACROSS SOUTH CENTRAL AND CENTRAL KANSAS AS THE
LOW LEVEL JET STRENGTHENS. A FEW OF THESE STORMS COULD ALSO BECOME
SEVERE WITH LARGE HAIL BEING THE MAIN CONCERN. DEPENDING ON HOW MUCH
CLEARING IS SEEN DURING THE AFTERNOON, HIGHS ON MONDAY ARE
ANTICIPATED TO RANGE FROM THE MID 70S ACROSS THE I-70 CORRIDOR TO
AROUND 80 ACROSS THE KS/OK BORDER. LOWS TUESDAY MORNING ARE
ANTICIPATED TO RANGE FROM THE LOWER 50S ACROSS THE KS/CO BORDER TO
LOWER 60S ACROSS SOUTH CENTRAL KANSAS WHERE DEWPOINTS WILL BE AROUND
60 DEGREES.
LEE TROUGHING DEVELOPS ACROSS EASTERN COLORADO TUESDAY MORNING IN
RESPONSE TO THE NEXT UPPER LEVEL TROUGH MOVING THROUGH THE NORTHERN
ROCKIES. SOUTHERLY WINDS WILL INCREASE IN SPEED AND BRING ADDITIONAL
LOW LEVEL MOISTURE UP FROM THE SOUTH. THIS WILL ALSO CAUSE ANOTHER
DRYLINE TO FORM ACROSS EASTERN COLORADO. MODELS SUGGEST A COLD FRONT
TO MOVE SOUTH FROM THE DAKOTAS INTO NEBRASKA AND NORTHERN KANSAS BY
WEDNESDAY MORNING. THIS WILL SHIFT THE SURFACE TROUGH AND DRYLINE
FARTHER EAST. THE AFOREMENTIONED COLD FRONT IS FORECASTED TO MOVE
FARTHER SOUTH WEDNESDAY THEN STALL OUT ACROSS CENTRAL KANSAS IN THE
AFTERNOON. A SLIGHT CHANCE OF THUNDERSTORMS WILL BE POSSIBLE
WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING ALONG AND EAST OF THE
DRYLINE AND COLD FRONT. HIGHS TUESDAY THROUGH THURSDAY ARE
FORECASTED TO RISE INTO THE 80S WITH THE POSSIBILITY OF AROUND 90
DEGREES ACROSS FAR SOUTHWESTERN KANSAS. LOWS WEDNESDAY THROUGH
FRIDAY MORNING ARE EXPECTED TO RANGE FROM THE MID 50S ACROSS THE
KS/CO BORDER TO LOWER 60S ACROSS SOUTH CENTRAL AND CENTRAL KANSAS.
EXTENDED MODELS THEN SUGGEST UPPER LEVEL RIDGING DEVELOPING ACROSS
THE SOUTHERN ROCKIES FRIDAY INTO SATURDAY WITH A TROUGH OF LOW
PRESSURE ENTERING THE WESTERN CONUS. A WEAK AREA OF LOW PRESSURE IS
DEPICTED ACROSS THE TEXAS PANHANDLE DURING THIS TIMEFRAME WHICH WILL
CONTINUE SOUTHERLY WINDS ACROSS WESTERN KANSAS. NO PRECIPITATION IS
EXPECTED AT THIS TIME WITH PARTLY CLOUDY SKIES. HIGHS FRIDAY AND
SATURDAY ARE FORECASTED TO RISE INTO THE MID TO UPPER 80S WITH LOWS
AROUND 60 DEGREES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1234 AM CDT SUN APR 29 2012
VFR CONDITIONS WILL CONTINUE WITH SCATTERED SHOWERS AND
THUNDERSTORMS INCREASING IN COVERAGE AFTER 12 TO 14Z. EXPECT MVFR
CONDITIONS WITH THUNDERSTORMS. THE STORMS WILL BE ELEVATED, WITH A
SKINNY AREA OF CAPE, NORTH OF A COLD FRONT AND LASTING INTO 06Z.
THE RAINFALL INDUCED BY RR JET CIRCULATION AND A WEAK UPPER LEVEL
TROUGH.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 68 55 77 58 / 40 50 40 30
GCK 67 54 78 56 / 50 50 40 20
EHA 69 54 81 53 / 60 50 30 20
LBL 69 55 82 55 / 50 50 40 30
HYS 66 53 76 59 / 30 40 30 30
P28 68 59 78 62 / 70 50 40 40
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RUSSELL
SHORT TERM...RUSSELL
LONG TERM...HOVORKA 42
AVIATION...KRUSE
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
1241 AM CDT SUN APR 29 2012
...UPDATED FOR AVIATION...
.SYNOPSIS...
ISSUED AT 359 PM CDT SAT APR 28 2012
THE NEXT 24 HOURS WILL BE A CHALLENGING FORECAST WITH CONVECTIVE
CHANCES HAVING AN IMPACT ON TEMPERATURES. ANY UPPER VORTEX IS
CURRENTLY SPINNING EASTWARD INTO THE NORTHERN PLAINS AS OBSERVED ON
INFRARED SATELLITE. TO THE SOUTH OF THIS LOW IS AN UPPER JET
STREAKING ACROSS THE CENTRAL AND SOUTHERN ROCKIES INTO THE HIGH
PLAINS REGION. IT HAS BEEN OBSERVED THAT EVEN WITH THE INCOMING NOSE
OF THE UPPER JET, NO CONVECTION HAS BEEN OBSERVED THROUGH THE
MOUNTAINS IN THE LIGHTNING DETECTION NETWORK PLOT. A STATIONARY
FRONT WAS DRAPED ACROSS CENTRAL AND WESTERN OKLAHOMA WITH HIGH
DEW POINTS IN THE MID 60S, WHILE BEHIND THE BOUNDARY LIGHT
NORTHEAST WINDS COVERED WESTERN KANSAS.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 359 PM CDT SAT APR 28 2012
THE COMBINATION OF MID LEVEL INSTABILITY AND UPPER FORCING WILL BE
THE MAJOR PLAYER IN ANY CONVECTIVE EVOLUTION OVER THE NEXT 24 TO 36
HOURS. AS THE UPPER WAVE APPROACHES TONIGHT, WESTERN KANSAS WILL BE
MORE IN CLOSE PROXIMITY OF AN UPPER RIGHT ENTRANCE JET REGION,
PROMOTING A THERMALLY INDIRECT CIRCULATION. THE PREEXISTING
ATMOSPHERE WILL BE CONDITIONALLY UNSTABLE SO CONVECTION IS POSSIBLE
INCREASING FROM THE WEST OVERNIGHT. THE HIGH RESOLUTION ARW AND NMM
MODELS AND THE NAM PRODUCE QPF IN THIS ZONE BETWEEN MIDNIGHT AND
12Z. MOVING INTO THE EARLY SUNDAY MORNING TIMEFRAME, THE UPPER
TROUGH AXIS WILL ROTATE CLOSER TO WESTERN KANSAS INCREASING THE
HEIGHT GRADIENT AND PVA WHILE THE MODELS BEGIN TO LIFT THE
STATIONARY FRONT ACROSS WESTERN OKLAHOMA CLOSER TO THE
OKLAHOMA/KANSAS LINE LATE SUNDAY. AS A RESULT, ADDITIONAL
THUNDERSTORM CHANCES ARE WARRANTED THROUGH THE DAY ON SUNDAY. NAM
MODEL SHOWS SBCAPES INCREASING IN EXCESS OF 1000 J/KG, ESPECIALLY
ACROSS THE SOUTHWEST/WESTERN AND SOUTHERN SECTIONS OF KANSAS.
AS THE UPPER JET AND TROUGH MOVES THROUGH THE AREA ON SUNDAY,
ADDITIONAL THUNDERSTORMS CHANCES ARE EXPECTED THROUGH THE DAY AS THE
ATMOSPHERE DESTABILIZES AGAIN DIURNALLY. THE POSITION OF THE FRONT
TO THE SOUTH WILL BE THE MAIN FOCUS FOR CONVECTION, ESPECIALLY
SEVERE CONVECTION. HOWEVER, FROM MODEL LOW LEVEL FIELDS, IT APPEARS
SOUTHWEST KANSAS WILL BE ON THE NORTH SIDE OF THE BOUNDARY, SO THE
SEVERE POTENTIAL COULD BE RELEGATED PRIMARILY TO HAIL AND WIND
THREATS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 356 PM CDT SAT APR 28 2012
EARLY IN THE PERIOD (SUNDAY NIGHT) THE WEATHER WILL BE INFLUENCED BY
WHAT OCCURS TONIGHT AND SUNDAY AND IF THIS WILL DRIVE THE SURFACE
BOUNDARY BACK SOUTH. HOWEVER, WITH THE ROCKIES UPPER S/WV LIFTING
INTO THE MID-WEST AND WITH SURFACE PRESSURE FALLS IN THE FRONT RANGE
IT DOES APPEAR LIKELY THAT THE FRONT WILL LIFT NORTH. THERE SHOULD
BE CONVECTION MOVING OFF THE HIGHER TERRAIN SUNDAY NIGHT AND THIS
MAY LINGER INTO EARLY MONDAY AS THE AFOREMENTIONED FRONT MOVES
NORTH. DURING THE DAY MONDAY AND INTO MONDAY NIGHT ADDITIONAL
CONVECTION WILL BE POSSIBLE IN THE PRESENCE OF MID-LEVEL INSTABILITY
AND A DRY LINE THAT WILL EVENTUALLY MIX OUT OF EASTERN COLORADO INTO
MY WESTERN COUNTIES. HOWEVER, STILL THERE IS A LOT OF UNCERTAINTY
DEPENDING ON PREVIOUS CONVECTION THAT WILL NO DOUBT MODIFY THE
AIRMASS.
WITH CONTINUED WESTERLY FLOW DURING THE WEEK AND WITH LEE SIDE
PRESSURE FALLS THE DRY LINE SHOULD DIURNALLY RETREAT INTO EASTERN
COLORADO AT NIGHT AND MIX EAST DURING THE DAY. UNCERTAINTY WILL
EXIST HOWEVER ON WARMING ALOFT AND WHETHER FORCING WILL BE
SUFFICIENT TO PRODUCE ADDITIONAL THUNDERSTORMS. THUS, POPS WILL
REMAIN LOW DURING THE LATER PERIODS. TEMPERATURES WILL BE ABOVE
NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1234 AM CDT SUN APR 29 2012
VFR CONDITIONS WILL CONTINUE WITH SCATTERED SHOWERS AND
THUNDERSTORMS INCREASING IN COVERAGE AFTER 12 TO 14Z. EXPECT MVFR
CONDITIONS WITH THUNDERSTORMS. THE STORMS WILL BE ELEVATED, WITH A
SKINNY AREA OF CAPE, NORTH OF A COLD FRONT AND LASTING INTO 06Z.
THE RAINFALL INDUCED BY RR JET CIRCULATION AND A WEAK UPPER LEVEL
TROUGH.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 53 77 57 87 / 50 30 30 10
GCK 52 78 55 88 / 50 30 20 10
EHA 52 81 52 89 / 50 30 20 0
LBL 53 82 54 90 / 50 30 20 0
HYS 50 76 58 84 / 40 20 30 20
P28 57 78 61 83 / 50 30 30 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RUSSELL
SHORT TERM...RUSSELL
LONG TERM...HUTTON
AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS PADUCAH KY
956 AM CDT SUN APR 29 2012
.UPDATE...
ISSUED AT 951 AM CDT SUN APR 29 2012
UPDATED THE PUBLIC FORECAST TO PUSH IT TOWARD THE HRRR FORECAST.
LOOKS LIKE WE MAY HAVE A REPEAT OF YESTERDAY...WITH MOST OF THE
THUNDERSTORM ACTIVITY STAYING JUST NORTH OF THE FORECAST AREA. THE
HRRR LIFTS THE BOUNDARY NORTHWARD TO NEAR INTERSTATE 64 BY THE END
OF THE DAY...AND DESPITE SOME HIGH CLOUDS THERE SHOULD BE PLENTY
OF SUNSHINE SOUTH OF THE BOUNDARY TO ALLOW TEMPERATURES TO CLIMB
WELL INTO THE 80S. KEPT THE AFTERNOON POPS...BUT DRIED OUT THIS
MORNING. WILL GET A LOOK AT ALL OF THE 12Z GUIDANCE BEFORE WIPING
OUT MORE OF THE AFTERNOON POPS. ALSO INCREASED SOUTHERLY WINDS
OVER THE SOUTHERN HALF OF THE AREA THIS AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 315 AM CDT SUN APR 29 2012
WITH CONVECTION STILL FIRING NEAR THE DOORSTEP OF THE NORTHERN WFO
PAH FORECAST AREA AT PRESS TIME...THERE IS SOME CONCERN ON THE
EVENTUAL SOUTHWARD EXTENSION OF THE CONVECTION LATER TODAY. THE
LAST SEVERAL RUNS OF THE LAPS MASS/MOISTURE/INSTABILITY FIELDS
SHOW SOME RETRACTION OF THE THE MAIN THETA-E RIDGE BACK INTO
SOUTHERN MISSOURI. THIS IS IN LINE WITH THE DEEPER THETA-E RIDGE
DEPICTED ON THE 00Z SUNDAY MANDATORY UPPER AIR CHARTS. THERE IS
ALSO A DEPICTION OF A SECONDARY...BUT LESS EFFECTIVELY ORIENTED
WEST TO EAST THETA-E MAX ALONG THE OHIO RIVER BORDERING
KENTUCKY...INDIANA AND OHIO. ALTHOUGH FORCING WITH MINOR UPPER
LEVEL JET SUPPORT IN THE AFOREMENTIONED AREA MAY BE A CONCERN
EARLY ON...RIDGING ALOFT MAY MITIGATE ANY ORGANIZED
CONVECTION...LEAVING DIURNALLY GENERATED OUTFLOW CONVECTION THE
PRIMARY THUNDERSTORM FOCUS OVER SOUTHWEST INDIANA. SOUTHWEST
INDIANA AND NORTHWEST KENTUCKY WILL BE A TOSS UP ON THUNDERSTORM
COVERAGE...PERSISTENCE AND INTENSITY THIS AFTERNOON AND INTO EARLY
THIS EVENING. LATER SHIFTS WILL NEED TO MONITOR THIS AREA AND MAKE
ADJUSTMENTS ACCORDINGLY. THE SOUTHERN EXTENT OF THE CONVECTION
TODAY...AT ITS MAXIMUM...LINES UP WITH THE EARLY MORNING DAY ONE
SPC SEVERE WEATHER OUTLOOK. AGAIN...WITH THE BOUNDARY
NEARBY...THERE IS GOING TO BE A SHARP DEMARCATION ON RAIN VERSUS
NO RAIN TODAY.
ALTHOUGH THE NAM-WRF HAS BEEN AN EXCELLENT PERFORMER THE LAST FEW
MODEL RUNS...THE DETERMINISTIC GFS AND ECMWF APPEARED TO HAVE A
GOOD HANDLE ON THE OVERALL SYNOPTIC PICTURE WITH RESPECT TO THE
LOW LEVEL RIDGING OVER THE WFO PAH AREA...AS THICKNESSES AND
HEIGHTS RAISE IN ADVANCE OF THE THE LARGE NORTHWEST U.S. CLOSED
LOW. ADJUSTED MAX/MIN TEMPERATURES 1-2 DEGREES HIGHER OUTSIDE OF
THE EXPECTED CONVECTIVE ACTIVITY TODAY THROUGH TUESDAY. THE ONLY
CAVEAT WILL BE THE IMPACT OF PERSISTENT OR TRANSIENT CLOUD COVER
ON THESE TEMPERATURES THE NEXT SEVERAL DAYS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 315 AM CDT SUN APR 29 2012
HPC PREFERS A GEFS/GFS BLEND SOLUTION IN THE LONG TERM...WITH MORE
WEIGHT GIVEN TO THE GEFS DAY 5 AND BEYOND. WE AGREE GIVEN THE ECMWF
SEEMS TO BE FLIP FLOPPING QUITE A BIT IN SOME RESPECTS. ALL IN ALL
STILL A LOW CONFIDENCE PRECIPITATION FORECAST GIVEN THE NATURE OF
THE UPPER FLOW PATTERN. CONFIDENCE IS RELATIVELY HIGH THOUGH...THAT
TEMPERATURES WILL RUN ABOVE NORMAL.
NOT MUCH TO TRIGGER CONVECTION TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.
SOUTHWEST FLOW ALOFT MAY CONTAIN A WEAK IMPULSE OR TWO...THAT
COMBINED WITH A LITTLE INSTABILITY COULD TRIGGER VERY ISOLD
CONVECTION. HOWEVER DOES NOT APPEAR ENOUGH OF A CHANCE TO WARRANT
A MENTION JUST YET. STARTING THURSDAY...WE INTRODUCE SLIGHT CHANCE
POPS AS A BIT MORE MOISTURE IS FORECAST TO WORK NORTHWARD FROM THE
GULF COAST REGION. MEANWHILE...A PERSISTENT SOUTHWEST FLOW ALOFT
WILL GRADUALLY TURN NORTHWEST THURSDAY NIGHT INTO FRIDAY...WHICH
SHOULD ALLOW A FRONTAL BOUNDARY TO MOVE INTO THE REGION BY FRIDAY
NIGHT. AS A RESULT WE WILL CARRY LOW CHANCE POPS FOR CONVECTION
THURSDAY NIGHT THROUGH SATURDAY...THEN DRY IT OUT SATURDAY NIGHT
INTO SUNDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 627 AM CDT SUN APR 29 2012
KEPT THE TERMINAL FORECASTS SIMPLE. STATIONARY FRONT FROM JUST
NORTH OF KPOF TO JUST SOUTH OF KOWB WILL SLOWLY LIFT NORTH THROUGH
THE FORECAST PERIOD. CONVECTIVE CHANCES TOO LOW TO CARRY IN THE
FORECAST AT THIS TIME. JUST SCT CU CLOUDS AND A FAIR AMOUNT OF
HIGH CLOUD COVER. SOME LIGHT FOG HAS FORMED JUST NORTH OF THE
FRONT EARLY THIS MORNING. WILL HAVE TO MONITOR THIS TREND
ESPECIALLY FOR KEVV AND KOWB.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
200 AM EDT SUN APR 29 2012
.UPDATE...
ISSUED AT 200 AM EDT SUN APR 29 2012
UPDATED THE FORECAST TO MAINLY ADJUST THE POP...WX AND SKY GRIDS
GIVEN THE EVOLUTION OF THE CONVECTION TO THE NORTHWEST AND EXPECTED
GRADUAL DISSIPATION IN OUR AREA LATER THIS MORNING. ALSO TWEAKED THE
TEMP AND DEWPOINT GRIDS FOR CURRENT OBSERVATIONS AND TRENDS.
UPDATE ISSUED AT 1039 PM EDT SAT APR 28 2012
UPDATED THE FORECAST TO REFLECT CURRENT CONDITIONS AND MODEL TRENDS.
THE STORMS HAVE WEAKENED SO TOOK OUT ANY MENTION OF SEVERE
THUNDERSTORMS OUT OF THE FORECAST. THE REST OF THE FORECAST IS ON
TRACK.
UPDATE ISSUED AT 905 PM EDT SAT APR 28 2012
WE HAVE BEEN MONITORING THUNDERSTORMS UPSTREAM OVER CENTRAL AND NORTH
CENTRAL KENTUCKY. ONE OF THESE STORMS HAS PRODUCED BASEBALL SIZED
HAIL OVER SOUTHERN INDIANA. THERE IS A GENERAL WEAKENING TREND FOR
THESE STORMS AS THEY MOVE EAST SOUTHEAST TOWARDS EASTERN KENTUCKY.
EXTRAPOLATING THE MOVEMENT OF THE STRONGEST STORM WOULD HAVE IT
MOVING INTO ESTILL COUNTY AROUND 11 PM. HAVE UPDATED THE FORECAST TO
REFLECT THE CURRENT CONDITIONS AND MODEL TRENDS.
UPDATE ISSUED AT 512 PM EDT SAT APR 28 2012
UPDATED THE FORECAST TO REFLECT CURRENT CONDITIONS AND MODEL TRENDS.
THE AIRMASS OVER THE AREA REMAINS QUITE UNSTABLE BUT CAPPED. THE
MODELS ARE SHOWING THAT THE CAPPING SHOULD BE DECREASING AS THE FRONT
PUSHES SOUTH BACK INTO EASTERN KENTUCKY. WITH THE
INSTABILITY...CONVECTION COULD BUILD ABOUT ANYWHERE...BUT RIGHT
NOW...THE BEST BET IS THAT SOMETHING WILL DEVELOP FROM OUTFLOWS FROM
THE STORMS CURRENTLY OVER THE ILLINOIS/INDIANA BORDER. THE HRRR MODEL
IS SHOWING SOME CONVECTION FORMING NORTH OF I-64 BY 8 PM. WILL
CONTINUE TO MONITOR CLOSELY. WE HAVE GASOLINE...WE JUST NEED A MATCH.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 330 PM EDT SAT APR 28 2012
CONVECTION STILL HAVING A HARD TIME INITIATING THIS AFTERNOON WITH
19Z SFC ANALYSIS INDICATING THE WARM FRONT CURRENTLY BISECTING THE
COMMONWEALTH FROM WEST TO EAST. TO THE SOUTH OF THE BOUNDARY...SFC
TEMPS IN THE UPPER 70S COUPLED WITH DEW POINTS APPROACHING 60 DEGREES
HAS RESULTED IN SOME DECENT SFC BASED INSTABILITY. HOWEVER...BOTH THE
NAM AND GFS BUFR SOUNDINGS DO STILL SHOW ENOUGH OF A CAP TO LIMIT
CONVECTIVE POTENTIAL SOUTH OF THE HAL ROGERS AND TO A LESSER EXTENT
SOUTH OF THE MTN PARKWAY AS WELL. TO THE NORTH...DEBRIS FROM ACTIVITY
IN IN/OH EARLIER TODAY HAS PUT A LIMIT ON THE TEMP RECOVERY WITH THE
MERCURY JUST STARTING TO CREEP INTO THE MID 60S...THOUGH DEW POINTS IN
THE UPPER 40S TO LOWER 50S HAS PRECLUDED ANY SIGNIFICANT INSTABILITY
FROM DEVELOPING.
FORECAST CHALLENGE FOR THE REMAINDER OF THE AFTERNOON AND EVENING
REMAINS POPS...CONVECTIVE POTENTIAL...AND THE THREAT FOR SEVERE
STORMS. CURRENT SAT IMAGERY SHOWS ANOTHER SHORT WAVE MOVING THRU
CENTRAL IL RIDING ALONG THE SFC BOUNDARY DRAPED ALONG THE OHIO RIVER.
THIS WAVE IS ON PACE TO REACH OUR BLUEGRASS LATER THIS EVENING...WHEN
FCST SOUNDINGS SHOW A DECLINE IN CAPE. NOT REALLY SEEING ANY
APPRECIABLE OUTFLOW BOUNDARIES FROM ACTIVITY TO THE NORTH...THOUGH
WOULD SUSPECT THAT THERE IS AT LEAST 1 OR 2 THAT WOULD BE PUSHING
SOUTH AND WOULD ENHANCE THE FRONTAL BOUNDARY WHICH WILL SERVE AS THE
FOCUS FOR ANY STORMS THIS AFTERNOON AND EVENING. BEST CHANCES FOR
SEVERE STORMS THIS GO AROUND APPEAR TO BE NORTH OF THE MTN PARKWAY
THRU SUNSET. THEREAFTER...LACK OF UPPER LEVEL DYNAMICS AND THE USUAL
DECLINE IN SFC BASED INSTABILITY WITH THE SUNSET SHOULD CURTAIL ANY
SEVERE THREAT OVERNIGHT...THOUGH WILL NOT COMPLETELY RULE OUT SOME
TSTM ACTIVITY OVERNIGHT AS THE FRONT BEGINS TO SAG BACK TO THE SOUTH.
SHORTWAVE RIDGING TRAVERSES THE LOWER AND MID OHIO VALLEY ON SUNDAY
AND SHOULD LIMIT ANY SIGNIFICANT PRECIP CHANCES THROUGH SUNDAY NIGHT.
WILL CARRY A SLIGHT CHANCE FOR TSTMS ON SUNDAY WITH LOW LEVEL
MOISTURE LINGERING OVER THE AREA AND A POTENTIALLY ACTIVE BOUNDARY
STILL DRAPED OVER THE AREA. TEMPERATURES WILL VARY CONSIDERABLY
DEPENDING ON WHERE THE BOUNDARY ENDS UP...WITH MID TO UPPER 60S
EXPECTED NORTH OF THE FRONT ON SUNDAY AND UPPER 70S TO THE SOUTH. THE
SPREAD AMONG THE LOWS TONIGHT AND SUNDAY NIGHT SHOULD BE MORE
LIMITED GIVEN THE EXPECTED CLOUD COVER...BUT WILL GENERALLY RANGE
FROM AROUND 50 IN THE NORTH TO AROUND 60 IN THE SOUTH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 330 PM EDT SAT APR 28 2012
LOOKING AT A NEARLY ZONAL...OR LOW AMPLITUDE UPPER PATTERN THROUGH
THE EXTENDED WITH GENERALLY SOUTHWEST FLOW OVER EASTERN KENTUCKY
THROUGH THE BULK OF THE PERIOD. OUR CWA REMAINS FAIRLY CLOSE TO THE
MEAN WESTERLIES HOWEVER AND AS SUCH WILL BE SUSCEPTIBLE TO SEVERAL
WEAK IMPULSES TRAVELING THROUGH THE MEAN FLOW. TIMING OF THESE
IMPULSES WILL BE TRICKY AS MODELS TYPICALLY HAVE TROUBLE IN THIS
TYPE OF PATTERN. LOW AMPLITUDE MEAN TROUGH POSITIONED OVER THE
WESTERN CONUS DOES TEND TO MOVE EASTWARD WITH TIME AND APPEARS TO
HAVE THE MOST SIGNIFICANT IMPACT ON OUR WEATHER TOWARDS THE END OF
THE WEEK.
FOR SENSIBLE WEATHER...BROAD BRUSH POPS WOULD PROBABLY BE BEST
APPROACH. BUT DECIDED TO FOCUS POPS WITH BEST GUESS AT TIMING OF
SHORT WAVE IMPULSES. LINED UP HIGHER POPS FOR A MONDAY NIGHT THROUGH
TUESDAY EVENING TIME FRAME. SHORT WAVE RIDGING AHEAD OF TROUGH
PULLING OUT OF THE WESTERN CONUS WILL MORE THAN LIKELY KEEP
WEDNESDAY DRY AS A CAP KEEP CONVECTION AT A MINIMUM. UNSETTLED
WEATHER RETURNS AT THE END OF THE EXTENDED...LATE THURSDAY OR FRIDAY
AS TROUGH ROLLS INTO THE REGION.
BEING ON THE SOUTH SIDE OF MEAN FLOW TEMPERATURES SHOULD AVERAGE
ABOVE NORMAL THROUGH THE WEEK. BUT COOLER...MORE NORMAL WEATHER
SHOULD RETURN WITH THE ARRIVAL OF AFOREMENTIONED TROUGH AT THE END
OF THE FORECAST WINDOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 200 AM EDT SUN APR 29 2012
A CLUSTER OF THUNDERSTORMS OVER CENTRAL KENTUCKY ARE TRENDING
WEAKER...HOWEVER THERE IS STILL A POSSIBLY TO SEE THEIR REMNANTS MAKE
IT INTO THE FORECAST AREA OVER THE NEXT SEVERAL HOURS. THE AVN GRIDS
HAVE BEEN ADJUSTED WITH THIS THOUGHT IN MIND...THOUGH FOR THE
OFFICIAL TAF SITES QUIET WX SHOULD BE THE RULE THROUGH THE PERIOD.
SOME MVFR FOG WILL BE POSSIBLE IN THE PREDAWN HOURS AT LOZ AND SME
SHOULD THE THICKER CLOUDS ALOFT THIN AS THE THUNDERSTORMS CONJURING
THEM WANE. ANY CONVECTION IN THE AREA ON SUNDAY WILL BE PRIMARILY
WELL NORTH OF THE TAF SITES SO HAVE KEEP THEM CLEAN...THOUGH MID
LEVEL CLOUDS WILL LIKELY REMAIN PLENTIFUL THROUGH THE DAY. WINDS WILL
BE GENERALLY LIGHT AND VARIABLE...AWAY FROM ANY STORM THROUGH SUNDAY
NIGHT...AS WELL.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...MB
LONG TERM....RAY
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
857 PM EDT MON APR 30 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM, COMING EAST FROM ILLINOIS, WILL BRING
SHOWERS AND THUNDERSTORMS TONIGHT INTO TUESDAY MORNING. A
LINGERING WARM FRONT WILL MAINTAIN WARM CONDITIONS AND A CHANCE OF
SHOWERS AT TIMES INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
SURFACE WARM FRONTAL BOUNDARY HAS FAILED TO MAKE ANY MORE
NORTHWARD PROGRESS WITH THE LOSS OF DAYTIME HEATING. HOWEVER...A
LARGE CHUNK OF THE CWA BASICALLY FROM PITTSBURGH TO THE SOUTH AND
WEST REMAINS DEEPLY ENTRENCHED IN THE WARM SECTOR. SHEAR VALUES IN
THE 0-6 KM LAYER REMAIN TOWARD 50 KTS AND HRRR MODEL
REFLECTIVITIES SUGGEST THE ACTIVITY TO OUR WEST IS LIKELY TO
PROGRESS INTO THE AREA AND FALL APART AFTER MIDNIGHT AS IT PASSES
PITTSBURGH. THIS JIVES FAIRLY WELL WITH DATA FROM THE GFS AND NAM
THAT REALLY START TO MARGINALIZE THE INSTABILITY PARAMETERS BY
AROUND 06Z. AS A RESULT...STRONG POPS FOR SHOWERS AND
THUNDERSTORMS REMAIN IN THE FORECAST FOR THE CONVECTIVE ACTIVITY
AS IT ENTERS THE AREA AND COMES INTO PITTSBURGH...HOWEVER THEY
START TO TAPER OFF TOWARD MORNING AS INSTABILITY FALTERS AND LIFT
BECOMES LESS IMPRESSIVE. FRIES
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
BLEND OF RECENT SREF AND ECMWF MODEL OUTPUT CONTINUES TO SHOW
UNCERTAINTY IN THE MEANDERINGS OF THE WARM FRONT ACROSS THE UPPER
OHIO VALLEY. SO HAVE OPTED TO MAINTAIN A CHANCE OF SHOWERS AND
THUNDERSTORMS ACROSS MUCH OF THE UPPER OHIO VALLEY FOR MOST OF
THIS PERIOD.
EXPECT TEMPERATURES TO CONTINUE MUCH WARMER THAN NORMAL, PER
RECENT GFS, NAM, AND ECMWF MOS AND SREF MODEL OUTPUT, WITH HIGHS
ABOVE 80 ACROSS LOWER ELEVATIONS SOUTH, AND LOWS IN THE 50S TO
LOWER 60S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
WARM FRONT WILL PUSH TO THE NORTH LATE WEDNESDAY AND EARLY
THURSDAY ALLOWING THE AREA TO ENTER BACK INTO THE WARM SECTOR. RIDGE
CONTINUES TO BUILD IN THE EAST...SO AS TEMPS RISE RAIN CHANCES
WILL DECREASE. DEWPOINTS WILL REMAIN IN THE 60S THROUGH THIS WHOLE
PERIOD.
RIDGE STARTS TO BREAK DOWN FRIDAY ALLOWING SFC COLD FRONT TO MOVE
TOWARD THE AREA. BUT THE FRONT WILL STALL OVER THE AREA THROUGH
THE WEEKEND WITH CHANCES FOR SHOWERS/THUNDERSTORMS.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
EASTBOUND LOW PRESSURE WILL BRING A BAND OF SHOWERS AND SCATTERED
THUNDERSTORMS ACROSS THE TERMINALS...BEGINNING ABOUT 02Z AT KZZV AND
03Z-05Z AT NORTHERN WV AND WESTERN PA TERMINALS. INCLUDED MENTION OF
TEMPO GROUPS FOR THUNDERSTORMS IN ALL TAFS...BUT POTENTIAL FOR
LARGE HAIL AND STRONG SURFACE GUSTS IS EXPECTED TO DIMINISH AS
INSTABILITY DECREASES OVERNIGHT. A PERIOD OF IFR STRATUS REMAINS IN
THE FORECAST LATE TONIGHT AS LOW LEVELS BECOME SATURATED FROM
EARLIER PRECIPITATION.
VERTICAL MIXING WILL HELP CEILINGS LIFT TO MVFR LEVELS LATE MORNING
AND VFR TUESDAY AFTERNOON.
.OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
RESTRICTIONS WILL REMAIN POSSIBLE IN SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH THE PERIOD.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
154 PM EDT SUN APR 29 2012
.SYNOPSIS...
HIGH PRESSURE WILL ALLOW FOR DRY WEATHER TODAY AND TONIGHT. A WARM
FRONT WILL APPROACH THE AREA FROM THE SOUTHWEST ON MONDAY, BRINGING
THE CHANCE OF THUNDERSTORMS. THE WARM FRONT WILL LIFT NORTH OF THE
AREA FOR THE MID-WEEK, WITH ABOVE NORMAL TEMPERATURES EXPECTED FOR
THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
18Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED WITH NO
CHANGES TO THE GOING FORECAST.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB RIDGE AXIS
CENTERED ACROSS THE WESTERN GREAT LAKES WITH THE UPPER OHIO VALLEY
IN A NORTHWESTERLY FLOW AHEAD OF THIS FEATURE. AT THE SURFACE, HIGH
PRESSURE EXTENDS FROM ONTARIO SOUTHEASTWARD ACROSS PENNSYLVANIA AND
INTO THE MID-ATLANTIC. THE 12Z KPIT SOUNDING INDICATED A DEEP
LAYER OF DRY AIR WITH SUBSIDENCE ALOFT. SAT IMAGERY CONFIRMS THIS
WITH CLEAR SKIES ASIDE FROM SOME PASSING CIRRUS.
THE MID-LEVEL RIDGE WILL MOVE INTO THE OHIO VALLEY THIS AFTERNOON
AND ACROSS THE AREA TONIGHT, ALLOWING FOR DRY WEATHER. HIGH
PRESSURE WILL SHIFT FROM ONTARIO INTO NY/EASTERN PA THROUGH THIS
PERIOD, ALLOWING LIGHT NORTHERLY WINDS TODAY TO SHIFT TO MORE
SOUTHEASTERLY BY DAWN ON MONDAY. SKIES WILL BE MOSTLY CLEAR TODAY,
WITH CLOUD COVERAGE BEGINNING TO INCREASE FROM THE SOUTH OVERNIGHT
AS MOISTURE SPILLS ACROSS A FRONTAL BOUNDARY TO THE SOUTH. TEMPS
TODAY ARE CLOSEST TO THE HRRR, WARMING TO NEAR NORMAL SEASONAL
VALUES. LOWS TONIGHT ARE CLOSER TO THE WARMER MET GUIDANCE.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
GFS/NAM/ECMWF ARE IN AGREEMENT THAT WARM FRONT WILL RETURN TO
REGION DURING THE DAY MONDAY AS SHORTWAVE RIDES MOVES ACROSS THE
GREAT LAKES. THIS WILL BRING AN INCREASING CHANCE FOR SHOWERS AND
STORMS DURING THE DAY. SURFACE LOW WILL MOVE TO LAKE ERIE MONDAY
NIGHT WITH COLD FRONT ENTERING THE REGION.
THE SURFACE LOW WILL PASS NORTH OF THE AREA MONDAY NIGHT, WITH
LIKELY POPS FORECAST ACROSS THE AREA. WITH THE WARM FRONT LIFTING
NORTH OF THE AREA, THE UPPER OHIO VALLEY WILL BE IN THE WARM
SECTOR TUESDAY AND WEDNESDAY. CHANCE POPS ARE FORECAST EACH DAY
WITH CONVECTION. UPPER LEVEL HEIGHTS WILL BE ON THE RISE THROUGH THE
PERIOD AS RIDGE DEVELOPS OFF THE CAROLINAS WITH ABOVE NORMAL
TEMPERATURES BY MID WEEK.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
LONG TERM FORECAST WAS BASED ON GFS/ECMWF ENSEMBLE MEANS AND
FEATURES THE FLATTENING OF BROAD ERN CONUS RIDGE AS THE WEEKEND
APPRCHES. ADJUSTMENTS WERE INCLUDED TO PCPN PROBABILITIES ON
THURSDAY AND FRIDAY TO ACCOUNT FOR EXPECTED FRONTAL POSITIONING.
SFC CDFNT IS STILL PROJECTED FOR A FRIDAY PASSAGE UNDER THIS
PATTERN...AND POPS WERE THUS REDUCED FOR THE WEEKEND.
WARM MIDWEEK TEMPERATURES SHOULD CONTINUE INTO THURSDAY WITH WARM
ADVECTION CONTINUING IN ADVANCE OF THE APPRCHG CDFNT. GIVEN THE
PROJECTED AMPLITUDE OF THE MID/UPR RIDGE...HAVE STAYED WITH THE
COOLER HPC GUIDANCE IN THAT TIME FRAME WHICH PROJECTS HIGHS
APPROXIMATELY 10 DEGREES ABOVE THE SEASONAL NORMALS.
THE AFOREMENTIONED RIDGE EROSION PROGNOSIS FOR THE WEEKEND IS NOT AS
DRAMATIC AS PREVIOUS SOLUTIONS...WITH EXCEPTION OF LATEST ECMWF
FORECAST WHICH HAS BEEN DISCOUNTED. TEMPERATURES WERE THUS FORECAST
CLOSER TO...BUT STILL A FEW DEGREES ABOVE THE NORMALS TO ACCOMPANY
THE REDUCED POPS.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
SURFACE HIGH PRES WL SLIDE ACRS THE GREAT LAKES AND CONTINUE TO PUSH
DRIER AIR OVR THE UPR OH VALLEY REGION TDA. ALTHOUGH HIGH...AND MID
LVL CLDS WL BE ON THE INCRS THROUGH TNGT...VFR CONDITIONS CAN BE
EXPECTED WITH LGT NORTH WIND VEERING TO THE EAST THROUGH THE TAF PD.
BY MONDAY MRNG...SHRA/TSRA ARE ANTICIPATED WITH WARM...MOIST SURGE
OVR THE UPR OH REGION. MVFR RESTRICTION SHOULD BE EXPECTED IN THIS
CONVECTIVE ACTIVITY...WHICH MAY CONTINUE INTO THE AFTN DEPENDING ON
TIMING OF SHRTWV SUPPORT.
.OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
RESTRICTIONS IN SCT SHRA AND TSRA ARE POSSIBLE MONDAY NGT THROUGH
WEDNESDAY AS GREAT LAKES LOW PRES ADVECTS WARMTH AND MOISTURE ACROSS
THE REGION. MORE TSRA ARE ANTICIPATED FOR THURSDAY IN ASSOCIATION
WITH THE SYSTEMS CDFNT APPRCH.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1109 AM EDT SUN APR 29 2012
.SYNOPSIS...
HIGH PRESSURE WILL ALLOW FOR DRY WEATHER TODAY AND TONIGHT. A WARM
FRONT WILL APPROACH THE AREA FROM THE SOUTHWEST ON MONDAY, BRINGING
THE CHANCE OF THUNDERSTORMS. THE WARM FRONT WILL LIFT NORTH OF THE
AREA FOR THE MID-WEEK, WITH ABOVE NORMAL TEMPERATURES EXPECTED FOR
THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
15Z ENHANCED SHORT TERM FORECAST HAS BEEN ISSUED TO INCREASE HIGH TEMPS
A FEW DEGREES ACROSS THE AREA.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB RIDGE AXIS
CENTERED ACROSS THE WESTERN GREAT LAKES WITH THE UPPER OHIO VALLEY
IN A NORTHWESTERLY FLOW AHEAD OF THIS FEATURE. AT THE SURFACE, HIGH
PRESSURE EXTENDS FROM ONTARIO SOUTHEASTWARD ACROSS PENNSYLVANIA AND
INTO THE MID-ATLANTIC. THE 12Z KPIT SOUNDING INDICATES A DEEP LAYER
OF DRY AIR WITH SUBSIDENCE ALOFT. SAT IMAGERY CONFIRMS THIS WITH
CLEAR SKIES ASIDE FROM SOME PASSING CIRRUS.
THE MID-LEVEL RIDGE WILL MOVE INTO THE OHIO VALLEY TODAY AND ACROSS
THE AREA TONIGHT, ALLOWING FOR DRY WEATHER. HIGH PRESSURE WILL SHIFT
FROM ONTARIO INTO NY/EASTERN PA THROUGH THIS PERIOD, ALLOWING LIGHT
NORTHERLY WINDS TODAY TO SHIFT TO MORE SOUTHEASTERLY BY DAWN ON MONDAY.
SKIES WILL BE MOSTLY CLEAR TODAY, WITH CLOUD COVERAGE BEGINNING TO
INCREASE FROM THE SOUTH OVERNIGHT AS MOISTURE SPILLS ACROSS A
FRONTAL BOUNDARY TO THE SOUTH. TEMPS TODAY ARE CLOSEST TO THE
HRRR, WARMING TO NEAR NORMAL SEASONAL VALUES. LOWS TONIGHT ARE
CLOSER TO THE WARMER MET GUIDANCE.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
GFS/NAM/ECMWF ARE IN AGREEMENT THAT WARM FRONT WILL RETURN TO
REGION DURING THE DAY MONDAY AS SHORTWAVE RIDES MOVES ACROSS THE
GREAT LAKES. THIS WILL BRING AN INCREASING CHANCE FOR SHOWERS AND
STORMS DURING THE DAY. SURFACE LOW WILL MOVE TO LAKE ERIE MONDAY
NIGHT WITH COLD FRONT ENTERING THE REGION.
THE SURFACE LOW WILL PASS NORTH OF THE AREA MONDAY NIGHT, WITH
LIKELY POPS FORECAST ACROSS THE AREA. WITH THE WARM FRONT LIFTING
NORTH OF THE AREA, THE UPPER OHIO VALLEY WILL BE IN THE WARM
SECTOR TUESDAY AND WEDNESDAY. CHANCE POPS ARE FORECAST EACH DAY
WITH CONVECTION. UPPER LEVEL HEIGHTS WILL BE ON THE RISE THROUGH THE
PERIOD AS RIDGE DEVELOPS OFF THE CAROLINAS WITH ABOVE NORMAL
TEMPERATURES BY MID WEEK.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
LONG TERM FORECAST WAS BASED ON GFS/ECMWF ENSEMBLE MEANS AND
FEATURES THE FLATTENING OF BROAD ERN CONUS RIDGE AS THE WEEKEND
APPRCHES. ADJUSTMENTS WERE INCLUDED TO PCPN PROBABILITIES ON
THURSDAY AND FRIDAY TO ACCOUNT FOR EXPECTED FRONTAL POSITIONING.
SFC CDFNT IS STILL PROJECTED FOR A FRIDAY PASSAGE UNDER THIS
PATTERN...AND POPS WERE THUS REDUCED FOR THE WEEKEND.
WARM MIDWEEK TEMPERATURES SHOULD CONTINUE INTO THURSDAY WITH WARM
ADVECTION CONTINUING IN ADVANCE OF THE APPRCHG CDFNT. GIVEN THE
PROJECTED AMPLITUDE OF THE MID/UPR RIDGE...HAVE STAYED WITH THE
COOLER HPC GUIDANCE IN THAT TIME FRAME WHICH PROJECTS HIGHS
APPROXIMATELY 10 DEGREES ABOVE THE SEASONAL NORMALS.
THE AFOREMENTIONED RIDGE EROSION PROGNOSIS FOR THE WEEKEND IS NOT AS
DRAMATIC AS PREVIOUS SOLUTIONS...WITH EXCEPTION OF LATEST ECMWF
FORECAST WHICH HAS BEEN DISCOUNTED. TEMPERATURES WERE THUS FORECAST
CLOSER TO...BUT STILL A FEW DEGREES ABOVE THE NORMALS TO ACCOMPANY
THE REDUCED POPS.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
SURFACE HIGH PRES WL SLIDE ACRS THE GREAT LAKES AND CONTINUE TO PUSH
DRIER AIR OVR THE UPR OH VALLEY REGION TDA. ALTHOUGH HIGH...AND MID
LVL CLDS WL BE ON THE INCRS THROUGH TNGT...VFR CONDITIONS CAN BE
EXPECTED WITH LGT NORTH WIND VEERING TO THE EAST THROUGH THE TAF PD.
BY MONDAY MRNG...SHRA/TSRA ARE ANTICIPATED WITH WARM...MOIST SURGE
OVR THE UPR OH REGION. MVFR RESTRICTION SHOULD BE EXPECTED IN THIS
CONVECTIVE ACTIVITY...WHICH MAY CONTINUE INTO THE AFTN DEPENDING ON
TIMING OF SHRTWV SUPPORT.
.OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
RESTRICTIONS IN SCT SHRA AND TSRA ARE POSSIBLE MONDAY NGT THROUGH
WEDNESDAY AS GREAT LAKES LOW PRES ADVECTS WARMTH AND MOISTURE ACROSS
THE REGION. MORE TSRA ARE ANTICIPATED FOR THURSDAY IN ASSOCIATION
WITH THE SYSTEMS CDFNT APPRCH.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
306 PM EDT SUN APR 29 2012
.SYNOPSIS...
ISSUED AT 305 PM EDT SUN APR 29 2012
HIGH PRESSURE WILL MOVE EAST AND A WARM FRONT WILL PUSH NORTH
TOWARDS SOUTHERN LOWER MICHIGAN TONIGHT. SOME SHOWERS AND
THUNDERSTORMS WILL BE ARRIVING AFTER MIDNIGHT TONIGHT THEN SPREAD
NORTH ON MONDAY. WARMER TEMPERATURES ALONG WITH SCATTERED SHOWERS
AND THUNDERSTORMS CAN BE EXPECTED FROM TUESDAY THROUGH THURSDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 305 PM EDT SUN APR 29 2012
AREA OF ISENTROPIC ASCENT NORTH OF SFC WARM FRONT IS GENERATING
RAIN ACROSS ILLINOIS THIS AFTERNOON. THIS WILL CONTINUE NORTHEAST
AND EDGE INTO FAR SOUTHWEST LOWER MICHIGAN THIS EVENING. LEADING EDGE
WILL HAVE TO OVERCOME DRY AIR INITIALLY BUT 12Z MODEL RH PROFILES
AND HRRR RUC INDICATE THE DRY AIR WILL BE OVERCOME AS LOW LEVEL
FLOW GOES SOUTHEAST WITH THE SFC RIDGE MOVING EASTWARD.
WILL BRING CHANCE POPS IN THIS EVENING AND THEN EXPAND NORTHWARD
AFTER MIDNIGHT. WILL HAVE THUNDERSTORMS ACROSS THE SOUTHERN
FORECAST AREA AS POTENTIAL FOR ELEVATED CONVECTION EXISTS WITH
TOTAL TOTALS IN THE UPPER 40S. MAIN SLUG OF QPF MOVES EAST DURING
THE DAY ALONG WITH DEEP MOISTURE...WHICH MEANS LIKELY POPS IN THE
MORNING FOLLOWED BY CHANCE POPS IN THE AFTERNOON.
MAX TEMPS WILL BE TRICKY ON MONDAY AS MODEL RH PROFILES SUGGEST
LOWER CLOUDS WILL STICK AROUND ALL DAY...AND UPSTREAM OBS IN THE
CLOUDS NORTH OF THE WARM FRONT THIS AFTERNOON ARE CURRENTLY STUCK
IN THE 40S. WENT A BIT BELOW GUIDANCE FOR MONDAY MAXES.
MONDAY NIGHT WILL SEE LOW CLOUDS DECREASE AS WEAK SFC RIDGING
BUILDS IN. WILL GO WITH A DRY FORECAST AS DEEP MOISTURE HAS
DEPARTED BY EVENING. GUIDANCE TEMPS HAVE TRENDED DOWNWARD AND SO
TWEAKED MINS LOWER.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 305 PM EDT SUN APR 29 2012
THE MAIN LONG TERM FCST CHALLENGE CONTINUES TO INVOLVE DETERMINING
PROBABILITIES FOR RAIN AND CONVECTION THROUGH MOST OF THE LONG RANGE
FCST PERIOD.
A WEAK HIGH PRESSURE RIDGE WILL PRODUCE DRY WX THROUGH AT LEAST
MIDDAY TUESDAY. WE WILL MAINTAIN MENTION OF A CHC OF SHOWERS/STORMS
OVER OUR SOUTHERN FCST AREA TUESDAY AFTERNOON AS THE WARM FRONT
LIFTS NORTH. IT WILL BE MILDER TUESDAY WITH MAX TEMPS REACHING THE
LOW TO MID 70S. SHOWERS AND A FEW TSTORMS ARE ANTICIPATED TUESDAY
NIGHT AS THE WARM FRONT CONTINUES TO LIFT NORTHWARD.
THE MODERATING TREND WILL CONTINUE WEDNESDAY WITH OUR FCST AREA
SOLIDLY IN THE WARM SECTOR WITH MAX TEMPS REACHING THE UPPER 70S TO
LOWER 80S. WE WILL MAINTAIN CHC POPS FOR SHOWERS/TSTORMS WEDNESDAY
AS MODERATE INSTABILITY DEVELOPS IN THE WARM SECTOR. HOWEVER I AM
NOT CONVINCED THAT THERE WILL BE A GOOD TRIGGERING MECHANISM/FOCUS
FOR CONVECTIVE INITIATION TO OCCUR. MOST OF THE DAY WILL LIKELY BE
DRY. 12Z GFS GUIDANCE SUGGESTS THE BETTER CONVECTIVE POTENTIAL
WEDNESDAY AFTERNOON WILL BE MUCH FURTHER NORTH NEAR THE WARM FRONT
AND ALSO WELL TO OUR NW IN CLOSER PROXIMITY TO THE SFC LOW OVER THE
UPPER MIDWEST.
THE WEDNESDAY NIGHT TIME FRAME REMAINS FAVORED FOR CONVECTIVE
DEVELOPMENT DUE LARGELY TO FORCING FROM A 35 TO 45 KT LLJ. 1000-850
MB MOISTURE TRANSPORT ALSO LOOKS FAVORABLE BY WEDNESDAY EVENING.
SHOWERS AND TSTORMS WILL LIKELY LINGER/REDEVELOP ON THURSDAY WITH
SHOWERS LINGERING FRIDAY BEFORE A COOLER AND DRIER AIRMASS ADVECTS
FOR THE WEEKEND WITH TEMPS RETURNING TO NEAR NORMAL BY THEN.
CANNOT RULE OUT A FEW STRONG TO SEVERE STORMS LATE WEDNESDAY THROUGH
THURSDAY AS INSTABILITY INCREASES ALONG WITH BRIEFLY STRONGER
FORCING FROM THE LLJ. HOWEVER WE CONCUR WITH THE PREVIOUS SHIFT THAT
THE OVERALL SEVERE WX THREAT MIDWEEK LOOKS FAIRLY LOW DUE TO SEVERAL
LIMITING FACTORS INCLUDING WEAK DEEP LAYER SHEAR STAYING GENERALLY
UNDER 30 KTS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 122 PM EDT SUN APR 29 2012
ASIDE FROM A STEADY BREEZE AT ABOUT 10 KTS THIS AFTERNOON AND
EVENING...NO SIGNIFICANT IMPACTS TO MENTION IN THE TAFS THROUGH
00Z. ATTENTION IS FOCUSED ON ARRIVAL OF SHOWERS OVERNIGHT AND
POTENTIAL IFR CONDITIONS AFTER 12Z MONDAY. AFTER LOOKING AT
OBSERVATIONS UPSTREAM IN NORTHERN MISSOURI AND SOUTHERN ILLINOIS
WHERE THE CURRENT BATCH OF RAINFALL IS...CIGS AND VISBYS ARE
INDICATIVE OF FAIRLY WIDESPREAD IFR CONDITIONS. I DO NOT EXPECT
THOSE CONDITIONS TO ARRIVE PRIOR TO 12Z...AND MAY HOLD OFF UNTIL
THE TAIL END OF THIS TAF PERIOD.
NAM MODEL RH FOR <1000 FT REVEALS SATURATED CONDITIONS OCCURRING
CLOSER TO NOON OR 1PM. THUS I INDICATED A BIT OF A BUFFER BY GOING
WITH 1500 FT CIGS BY 16Z AND LIKELY GOING TO IFR BY 18Z. COULD BE
SOME THUNDERSTORMS AROUND DURING THE MORNING BUT WATER
VAPOR/LIGHTNING ANALYSIS INDICATES THE TREND IS LESS FAVORABLE FOR
TSTORM DEVELOPMENT AS THIS SYSTEM MOVES TOWARD SW LOWER MICHIGAN.
&&
.MARINE...
ISSUED AT 305 PM EDT SUN APR 29 2012
WINDS AND WAVES SHOULD REMAIN BELOW SMALL CRAFT CRITERIA THROUGH
TUESDAY. THUNDERSTORMS ARE POSSIBLE SOUTH OF MUSKEGON ON MONDAY.
&&
.HYDROLOGY...
ISSUED AT 305 PM EDT SUN APR 29 2012
HEAVY RAIN IS POSSIBLE WEDNESDAY AND THURSDAY WHICH COULD LEAD TO
RISES ON THE RIVERS BY THE END OF THE WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM...LAURENS
AVIATION...HOVING
HYDROLOGY...OSTUNO
MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS BILLINGS MT
911 AM MDT SUN APR 29 2012
.SHORT TERM...VALID FOR TDY AND MON...
UPDATE TO FORECAST THIS MORNING TO INCREASE POPS OVER THE CENTRAL
ZONES. CLOSED UPPER LOW OVER WESTERN NORTH DAKOTA WAS CONTINUING
TO LIFT SLOWLY NORTHEAST THIS MORNING. MID LEVEL TROWAL WAS
CONTINUING TO WEAKEN AS IT SHIFTS EASTWARD. WATER VAPOR SATELLITE
WAS STILL INDICATING MID LEVEL MOISTURE OVER THE AREA AND AS
POINTED OUT BY THE MIDNIGHT SHIFT...WEAK PRESSURE ADVECTION AT
290 K ISENTROPIC WAS OCCURRING OVER CENTRAL MONTANA...BASED ON
THE RUC13 ANALYSIS. IN ADDITION...WEAK VORTICITY WAS ALSO
WRAPPING AROUND THE UPPER LOW ADDING ADDITIONAL LIFT OVER THE
AREA THIS MORNING. HAVE INCREASED POPS FOR THE REMAINDER OF THE
MORNING FOR COLUMBUS AND BILLINGS TO LIKELY. MODELS CONTINUE TO
INDICATE DRIER AIR MOVING IN FROM THE WEST AFTER 18Z AND CHANCE
OF PRECIPITATION WILL BECOME ISOLATED AT BEST FOR THE REST OF THE
DAY OVER THE WESTERN AND CENTRAL ZONES. PRECIPITATION CHANCES
ALSO DECREASING TO SCATTERED OVER SOUTHEAST MONTANA THIS
AFTERNOON AS THE STORM SYSTEM CONTINUES TO WEAKEN. TEMPERATURE
FORECAST CLOSE TO 12Z GUIDANCE AND WILL MAKE NO CHANGES. RICHMOND
.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
MODELS WERE IN FAIR AGREEMENT THROUGH FRIDAY...BUT NOT SO MUCH
FROM SATURDAY ONWARD. THERE WERE EVEN SOME SMALL DIFFERENCES IN
THE TIME OF AGREEMENT. THESE DIFFERENCES WERE ON OVERALL STRENGTH
AND TIMING OF SHORTWAVES IN A BROAD TROUGH PROGGED FOR TUESDAY
AND WEDNESDAY. ENERGY OVER THE ALEUTIAN ISLANDS WILL DROP INTO
THE PACIFIC NORTHWEST ON MONDAY. THIS ENERGY WILL MOVE INTO
WESTERN MONTANA EARLY TUESDAY AND CARVE OUT A BROAD TROUGH OVER
THE NORTHERN ROCKIES. THIS TROUGH WILL REMAIN IN PLACE FOR A
COUPLE OF DAYS AS ONE CHUNK OF ENERGY MOVES NORTHEAST INTO SOUTH
CENTRAL CANADA WHILE ANOTHER WAVE DROPS INTO THE PACIFIC
NORTHWEST. THIS WILL KEEP THE FORECAST SOMEWHAT UNSETTLED WITH
THE MOUNTAINS RECEIVING THE BEST SHOT OF SHOWERS. HAVE LOWERED
HIGHS A COUPLE OF DEGREES TUESDAY AND WEDNESDAY WITH LOW MID
LEVEL HEIGHTS.
THE SECONDARY PIECE OF ENERGY MOVING INTO THE TROUGH MENTIONED
ABOVE EXITS THE AREA WEDNESDAY NIGHT WITH A SMALL SCALE RIDGE
MOVING IN THURSDAY. THIS WILL BE SHORT LIVED HOWEVER AS DEEPENING
SHORTWAVE FLOW ALOFT WILL ALLOW SEVERAL WAVES OF ENERGY AND
MOISTURE TO STREAM INTO THE FORECAST AREA. THE MOUNTAINS WILL
RECEIVE THE BULK OF THE PRECIPITATION CHANCES...BUT THE PLAINS
WILL ALSO GET SCATTERED POPS WITH LOW LEVEL NORTHERLY FLOW. THE
STRONGEST POP DAY WILL LIKELY BE ON SATURDAY AS THE WESTERN
TROUGH KICKS ACROSS THE AREA. NOW THE ECMWF DOES NOT SWING THE
TROUGH INTO THE AREA. THE ECMWF DROPS THE TROUGH SOUTH IN
SPLITTING FLOW AND CUTS THE SOUTHERN STREAM OFF IN NEVADA.
MONTANA WOULD GET UPPER DIVERGENCE FORCING ON SUNDAY...WITH
SATURDAY BEING RELATIVELY DRY. DID NOT CHANGE POPS MUCH FOR THE
WEEKEND AS NEED TO GET THESE MODEL DIFFERENCES RESOLED BEFORE
PUSHING IN THE WET OR DRY DIRECTION. WILL LEAVE IN LOW SCATTERED
POPS FOR NOW. TWH
&&
.AVIATION...
A BAND OF LIGHT RAIN ALONG AND EAST OF A KSHR-KBIL-KLWT LINE WILL
CONTINUE THIS MORNING AND SLOWLY MOVE EAST DURING THE AFTERNOON.
FREQUENT MVFR CONDITIONS WILL OCCUR WITHIN THE PRECIPITATION WITH
OCCASIONAL IFR CONDITIONS EXPECTED. THE PRECIPITATION WILL TAPER
OFF THROUGH THE MORNING WITH CONDITIONS IMPROVING TO MAINLY VFR
THIS AFTERNOON. THE MOUNTAINS WILL CONTINUE TO BE MAINLY OBSCURED
THROUGHOUT THE DAY. CLOUDS WILL CONTINUE TO DECREASE FROM WEST TO
EAST THIS AFTERNOON INTO TONIGHT WITH IMPROVING CONDITIONS.
HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
TDY MON TUE WED THU FRI SAT
-------------------------------------------------------
BIL 056 039/067 045/063 039/063 041/066 045/068 045/065
7/R 12/W 33/T 21/B 11/B 11/B 22/W
LVM 055 034/059 037/058 032/057 033/061 036/063 037/061
3/R 23/W 44/T 21/B 12/W 22/W 23/W
HDN 056 035/069 046/065 039/065 040/068 043/070 044/067
7/R 11/B 23/T 21/B 11/B 11/B 22/W
MLS 050 037/069 048/065 041/065 041/065 045/069 046/067
7/R 21/B 22/T 22/W 11/B 11/B 22/W
4BQ 050 034/069 048/066 040/065 040/067 044/070 044/067
6/O 11/B 23/T 21/B 11/B 11/B 23/W
BHK 048 034/067 047/064 040/063 040/064 044/068 043/067
7/R 21/B 22/T 22/W 11/B 11/B 23/W
SHR 053 033/065 042/062 036/062 037/065 040/068 040/064
4/R 11/B 23/T 21/B 11/B 11/B 23/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
345 AM MDT SUN APR 29 2012
.SHORT TERM...VALID FOR TDY AND MON...
MOISTURE CHANNEL IMAGERY AND RUC OBJECTIVE ANALYSES PLACE THE MID-
LEVEL LOW JUST WEST OF DICKINSON ND AT 09 UTC. TODAY WILL MARK THE
EXIT OF THIS FEATURE AND THE END OF THE RECENT WET WEATHER...AND A
RETURN TO A MORE SEASONABLE /BUT STILL UNSETTLED/ PERIOD.
EARLY THIS MORNING...THE REMAINS OF THE WELL-DEVELOPED TROWAL HAVE
MADE THEIR WAY AS FAR WEST AS HARLOWTON AND BILLINGS. WE WILL NEED
TO KEEP LIKELY POPS IN THE FORECAST THROUGH 18 UTC WHERE THIS AREA
IS LINGERING...BUT THE WARM CONVEYOR BELT OF THE MID-LEVEL WAVE IS
DIMINISHING QUICKLY...SO THIS MOISTURE WILL BEGIN DECREASING LIKE
MODEL SOLUTIONS ALL SUGGEST. HOWEVER...IT OFTEN TAKES SOME TIME IN
ORDER FOR THIS TO OCCUR...AND INDEED THERE ARE STILL HINTS OF SOME
PRESSURE ADVECTION ON THE 290 K ISENTROPIC SURFACES THROUGHOUT THE
MORNING...SO WE DO NOT EXPECT THE PRECIPITATION TO END SUDDENLY BY
ANY MEANS. EVEN SO...THE RATES ARE ON THE WAY DOWN...SO WE DECIDED
TO CANCEL ALL OF THE WINTER WEATHER HEADLINES JUST A BIT EARLY.
FOR THE REST OF THE DAY...WE WILL KEEP SHOWER CHANCES GOING DUE TO
LINGERING CYCLONIC FLOW AND SOME LOW-LEVEL INSTABILITY REVEALED ON
FORECAST SOUNDINGS. HIGHS WILL PROBABLY NOT BE ABLE TO TOP 50 F IN
PARTS OF SOUTHEASTERN MT WHERE 850-HPA TEMPERATURES DO NOT RECOVER
TO +4 C UNTIL 00 UTC.
TONIGHT...WE HAVE DECIDED TO INCLUDE A MENTION OF PATCHY FOG AFTER
06 UTC ON THE PLAINS OF SOUTHEASTERN AND PART OF SOUTH CENTRAL MT.
ENHANCED NEAR-SURFACE MOISTURE DUE TO THE RECENT RAINFALL IS GOING
TO BE TRAPPED BENEATH A RADIATION INVERSION...WHICH COULD YIELD AT
LEAST SOME FOG IN LOW-LYING AREAS. BUFKIT-BASED TOOLS USING THE 00
UTC NAM SUPPORT THIS IDEA IN PLACES LIKE MILES CITY AND BAKER WITH
MINIMAL MIXING IN THE NEAR-SURFACE LAYER. ON THE OTHER HAND...MOST
OF THE GFS SOUNDINGS HAVE JUST ENOUGH LOW-LEVEL FLOW TO KEEP THOSE
BUFKIT TOOLS FROM SUGGESTING FOG. NONE OF THE MOS GUIDANCE SHOWS A
HINT OF FOG EITHER...SO THIS IS FAR FROM A SURE THING...THOUGH THE
RECENT MOISTURE IN AND OF ITSELF IS PERHAPS THE BEST INDICATOR.
MON...FLOW ALOFT WILL QUICKLY BACK AND LOW- AND MID-LEVEL WARM AIR
ADVECTION WILL OCCUR AHEAD OF A PACIFIC SHORT WAVE TROUGH. THIS IS
A DIFFICULT TEMPERATURE FORECAST THOUGH...AS MIXING TO 700 HPA MAY
BE OFFSET BY SIGNIFICANT MID- OR HIGH-LEVEL CLOUDS...AND INCREASED
GROUND MOISTURE ON THE PLAINS. THUS...OUR HIGHS ARE ACTUALLY A BIT
BELOW THE MULTI-MODEL CONSENSUS IN MANY CASES AT THIS POINT. THERE
WILL BE SHOWER CHANCES SPREADING FROM WEST TO EAST BY MON EVENING.
HOWEVER...THE EXIT REGION AND SUPPORTIVE UPPER-LEVEL DIVERGENCE OF
AN 80 KT 300-HPA JET STREAK WILL ACTUALLY BE FOCUSED OVER NORTHERN
MT...AND MID-LEVEL LAPSE RATES ARE NOT PARTICULARLY STEEP. POPS IN
THE LOWER ELEVATIONS ARE THUS MAINLY IN THE 20 TO 40 PERCENT RANGE
AT THIS POINT. ISOLATED THUNDERSTORMS ARE ALSO MENTIONED FOR PARTS
OF SOUTH CENTRAL MT...BUT WITH MUCAPE LESS THAN 250 J/KG ON THE 00
UTC GFS AND NAM...THAT MAY ACTUALLY BE REMOVED LATER. SCHULTZ
.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
MODELS WERE IN FAIR AGREEMENT THROUGH FRIDAY...BUT NOT SO MUCH
FROM SATURDAY ONWARD. THERE WERE EVEN SOME SMALL DIFFERENCES IN
THE TIME OF AGREEMENT. THESE DIFFERENCES WERE ON OVERALL STRENGTH
AND TIMING OF SHORTWAVES IN A BROAD TROUGH PROGGED FOR TUESDAY
AND WEDNESDAY. ENERGY OVER THE ALEUTIAN ISLANDS WILL DROP INTO
THE PACIFIC NORTHWEST ON MONDAY. THIS ENERGY WILL MOVE INTO
WESTERN MONTANA EARLY TUESDAY AND CARVE OUT A BROAD TROUGH OVER
THE NORTHERN ROCKIES. THIS TROUGH WILL REMAIN IN PLACE FOR A
COUPLE OF DAYS AS ONE CHUNK OF ENERGY MOVES NORTHEAST INTO SOUTH
CENTRAL CANADA WHILE ANOTHER WAVE DROPS INTO THE PACIFIC
NORTHWEST. THIS WILL KEEP THE FORECAST SOMEWHAT UNSETTLED WITH
THE MOUNTAINS RECEIVING THE BEST SHOT OF SHOWERS. HAVE LOWERED
HIGHS A COUPLE OF DEGREES TUESDAY AND WEDNESDAY WITH LOW MID
LEVEL HEIGHTS.
THE SECONDARY PIECE OF ENERGY MOVING INTO THE TROUGH MENTIONED
ABOVE EXITS THE AREA WEDNESDAY NIGHT WITH A SMALL SCALE RIDGE
MOVING IN THURSDAY. THIS WILL BE SHORT LIVED HOWEVER AS DEEPENING
SHORTWAVE FLOW ALOFT WILL ALLOW SEVERAL WAVES OF ENERGY AND
MOISTURE TO STREAM INTO THE FORECAST AREA. THE MOUNTAINS WILL
RECEIVE THE BULK OF THE PRECIPITATION CHANCES...BUT THE PLAINS
WILL ALSO GET SCATTERED POPS WITH LOW LEVEL NORTHERLY FLOW. THE
STRONGEST POP DAY WILL LIKELY BE ON SATURDAY AS THE WESTERN
TROUGH KICKS ACROSS THE AREA. NOW THE ECMWF DOES NOT SWING THE
TROUGH INTO THE AREA. THE ECMWF DROPS THE TROUGH SOUTH IN
SPLITTING FLOW AND CUTS THE SOUTHERN STREAM OFF IN NEVADA.
MONTANA WOULD GET UPPER DIVERGENCE FORCING ON SUNDAY...WITH
SATURDAY BEING RELATIVELY DRY. DID NOT CHANGE POPS MUCH FOR THE
WEEKEND AS NEED TO GET THESE MODEL DIFFERENCES RESOLED BEFORE
PUSHING IN THE WET OR DRY DIRECTION. WILL LEAVE IN LOW SCATTERED
POPS FOR NOW. TWH
&&
.AVIATION...
A BAND OF LIGHT RAIN AND LIGHT SNOW WILL LINGER OVER CENTRAL AND
EASTERN SECTIONS THIS MORNING. KBIL WILL BE NEAR THE WESTERN EDGE
OF THE PRECIPITATION...WITH THE HEAVIEST PRECIPITATION FALLING
BETWEEN KBIL AND KMLS. FREQUENT MVFR CONDITIONS WILL OCCUR WITHIN
THE PRECIPITATION WITH OCCASIONAL IFR CONDITIONS EXPECTED.
MOUNTAINS WILL BE OBSCURED. THE PRECIPITATION WILL TAPER OFF
THROUGH THE MORNING WITH CONDITIONS IMPROVING TO MAINLY VFR THIS
AFTERNOON. GUSTY WEST TO NORTHWEST WINDS WILL DECREASE THIS
MORNING. CLOUDS WILL DECREASE THIS AFTERNOON AND TONIGHT. PATCHY
FOG WILL BE POSSIBLE EAST OF KBIL TONIGHT. TWH
&&
.PRELIMINARY POINT TEMP/POPS...
TDY MON TUE WED THU FRI SAT
-------------------------------------------------------
BIL 056 039/067 045/063 039/063 041/066 045/068 045/065
6/R 12/W 33/T 21/B 11/B 11/B 22/W
LVM 055 034/059 037/058 032/057 033/061 036/063 037/061
3/R 23/W 44/T 21/B 12/W 22/W 23/W
HDN 056 035/069 046/065 039/065 040/068 043/070 044/067
7/R 11/B 23/T 21/B 11/B 11/B 22/W
MLS 050 037/069 048/065 041/065 041/065 045/069 046/067
7/R 21/B 22/T 22/W 11/B 11/B 22/W
4BQ 050 034/069 048/066 040/065 040/067 044/070 044/067
6/O 11/B 23/T 21/B 11/B 11/B 23/W
BHK 048 034/067 047/064 040/063 040/064 044/068 043/067
7/R 21/B 22/T 22/W 11/B 11/B 23/W
SHR 053 033/065 042/062 036/062 037/065 040/068 040/064
4/O 11/B 23/T 21/B 11/B 11/B 23/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
404 PM CDT SUN APR 29 2012
.SHORT TERM...THROUGH MONDAY AFTERNOON. UNFORTUNATELY...CONFIDENCE
IS BELOW AVERAGE DURING THE NEXT 24 HOURS REGARDING SEVERAL
ELEMENTS OF THE FORECAST...INCLUDING CLOUD/FOG TRENDS AND
THUNDERSTORMS/POSSIBLE SEVERE WEATHER CHANCES.
STARTING OFF WITH HERE AND NOW...19Z OBJECTIVE SURFACE ANALYSIS
INDICATES LIGHT EASTERLY BREEZES ACROSS MOST OF THE CWA...FLOWING
OUT OF A SURFACE HIGH CENTERED WELL TO THE NORTHEAST ACROSS THE
GREAT LAKES. THE CWA IS SITUATED WELL NORTH OF THE PRIMARY
REGIONAL SYNOPTIC EAST-WEST BOUNDARY/WARM FRONT...STRETCHED NEAR
THE OK/KS BORDER ACROSS SOUTHERN MO. ALOFT...WATER VAPOR IMAGERY
AND SHORT TERM MODEL DATA INDICATES A CLOSED 500MB LOW DRIFTING
NORTH OUT OF ND INTO CANADA...BUT WITH A TROUGH AXIS TRAILING
SOUTH-SOUTHWEST INTO THE NE/WY/CO BORDER AREA. AHEAD OF THIS
SYNOPTIC SCALE TROUGH AXIS...A LEAD SHORTWAVE IS IN THE PROCESS OF
EXITING THE CWA TO THE EAST...AND IS DRIVING ONGOING SHOWERS
ACROSS SOUTHEAST NEB. VISIBLE SATELLITE IMAGERY CONFIRMS WHY THE
TEMPERATURE FORECAST TODAY HAS BEEN FRUSTRATING...WITH AT LEAST
PARTIAL CLEARING DOMINATING SEVERAL COUNTIES WEST OF HIGHWAY
281...WHILE A SOLID LOW STRATUS DECK HAS STOOD FIRM ACROSS MUCH OF
THE CENTRAL/EAST...WITH A RENEWED NORTHWARD EXPANSION OF LOW
STRATUS NOW EVIDENT OUT OF NORTH CENTRAL KS. AS A RESULT...IT NOW
LOOKS LIKE MANY OF THESE CENTRAL/EASTERN COUNTIES MAY STRUGGLE TO
ATTAIN HIGHS IN THE MID-UPPER 50S...AT LEAST 5-10 DEGREES COOLER
THAN ORIGINALLY EXPECTED.
LATE THIS AFTERNOON THROUGH 00Z...WILL FOCUS THE MAIN CHANCES FOR
POSSIBLE SHOWER/STORM DEVELOPMENT WEST OF A LINE FROM
GREELEY-PLAINVILLE...WHERE CLEARING IS ALLOWING AT LEAST A FEW
HUNDRED J/KG OF 0-1KM MLCAPE TO BUILD. SHORT TERM REFLECTIVITY
PROGS FROM THE HRRR AND 12Z 4KM WRF-NMM SUPPORT THE POSSIBILITY OF
A FEW SHOWERS/STORMS DEVELOPING INTO THESE WESTERN ZONES BEFORE
DARK...AND ALTHOUGH NOT EXPECTING SEVERE WEATHER...A FEW INSTANCES
OF SMALL HAIL/GUSTY WINDS ARE NOT OUT OF THE QUESTION.
TURNING TO THE EVENING 00Z-06Z PERIOD...WILL KEEP LOW-END
THUNDERSTORM CHANCES GOING FOR MUCH OF NORTH CENTRAL KS...AND IN
NEB MAINLY WEST OF A GREELEY-ALMA LINE AS THE MAIN 500MB SHORTWAVE
AXIS SWINGS THROUGH THE CWA. AGAIN...SUPPOSE A FEW INSTANCES OF
SMALL HAIL NOT OUT OF THE QUESTION. FOR THE LATE NIGHT 06Z-12Z
PERIOD...KEPT LOW-END THUNDER CHANCES CONFINED TO A HANDFUL OF
FAR SOUTHWESTERN COUNTIES...IN CLOSEST PROXIMITY TO 850MB THETA-E
ADVECTION TIED TO A MODEST LOW LEVEL JET NOSING OUT OF WESTERN KS.
ALL THIS BEING SAID THOUGH...THE VAST MAJORITY OF THE CWA SHOULD
REMAIN DRY THROUGH THE NIGHT. TURNING TO OTHER OVERNIGHT
ISSUES...AFTER HAVING A ROUND OF LOCALLY DENSE FOG LAST
NIGHT...THERE ARE FAIRLY STRONG INDICATIONS IN NUMERICAL GUIDANCE
AND ALSO VISIBILITY PROBABILITY PROGS FROM THE SREF THAT ANOTHER
FAIRLY WIDESPREAD ROUND OF FOG SHOULD MATERIALIZE TONIGHT...THANKS
TO THE COMBINATION OF LIGHT WINDS AND A SATURATED BOUNDARY LAYER.
CONFIDENCE IN PLACEMENT WAS CERTAINLY NOT HIGH ENOUGH FOR A
HEADLINE YET...BUT WILL INSERT VISIBILITY BELOW 1 MILE INTO THE
GRIDS AND ALSO THE HWO. AS FOR LOW TEMPS...MAY END UP TOO COOL IF
A SOLID STRATUS BLANKET HOLDS FIRM...BUT WILL AIM FOR MID-UPPER
40S MOST AREAS.
TURNING TO MONDAY...OBVIOUSLY FOG COULD BE A CONCERN FOR THE FIRST
FEW HOURS AFTER SUNRISE. THEREAFTER...CONFIDENCE REMAINS UNUSUALLY
LOW IN THUNDERSTORM PROBABILITY/COVERAGE. THE GENERAL BIG PICTURE
INVOLVES A QUASI- ZONAL FLOW ALOFT...AS A LOW AMPLITUDE MID LEVEL
WAVE TRACKS FROM EASTERN CO INTO KS/SOUTHERN NEB. WITH WEAK
CAPPING EVIDENT IN FORECAST SOUNDINGS...AND CONTINUED 850MB
THETA-E ADVECTION...SEVERAL DETERMINISTIC MODELS SUCH AS THE
NAM/ECMWF/GFS ALL BRING STORMS INTO MUCH OF THE SOUTHWEST CWA
ALREADY IN THE MORNING...WHILE ON THE OTHER HAND...THE 4KM WRF-NMM
KEEPS THE MORNING CONVECTION-FREE. THEN DURING THE AFTERNOON...AN
EVEN STRONGER CONVECTIVE SIGNAL DEVELOPS IN SEVERAL DETERMINISTIC
MODELS...WHILE AGAIN THE 4KM REMAINS STRANGELY DRY. ALTHOUGH THE
ULTIMATE EXTENT OF DESTABILIZATION WILL BE STRONGLY INFLUENCED BY
HOW QUICKLY MORNING FOG/STRATUS VACATES...THE 18Z NAM ADVERTISES A
RESPECTABLE SEVERE WEATHER SETUP FOR THE MID-LATE AFTERNOON ACROSS
PARTS OF THE SOUTHERN CWA...BUT ESPECIALLY SOUTHERN ZONES WITH AT
LEAST 1500 J/KG 0-1KM MLCAPE...AND AROUND 40KT OF DEEP LAYER
SHEAR. ALTHOUGH THE OFFICIAL SPC DAY 2 SLIGHT RISK BARELY BRUSHES
THE FAR SOUTHERN CWA...WOULD NOT BE A BIT SURPRISED TO SEE THIS
EXTEND FARTHER NORTH ON THE UPCOMING DAY 1 PRODUCTS...AND WILL
INTRODUCE A SEVERE MENTION FOR HAIL/WIND IN THE HWO EXTENDING INTO
MONDAY EVENING. ALTHOUGH ONLY MODEST SHEAR IN THE LOWEST 1KM
SHOULD LIMIT A TORNADO THREAT...THIS POSSIBILITY IS ALSO NOT OUT
OF THE QUESTION NEAR THE NORTHWARD LIFTING INSTABILITY
GRADIENT/WARM FRONT IN KS ZONES. TEMPERATURE WISE MONDAY...STAYED
CLOSE TO GUIDANCE CONSENSUS...WHICH LOWERED MOST AREAS AT LEAST
2-3 DEGREES FROM PREVIOUS FORECAST INTO MAINLY THE 70-73 RANGE.
WOULD NOT BE SURPRISED THOUGH TO SEE WIDESPREAD CLOUDS ULTIMATELY
KEEP SOME AREAS IN THE 60S...JUST CAN/T SAY WHERE YET.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY. THIS IS VERY COMPLEX
WEATHER PATTERN WITH NUMEROUS WEAK SHORT WAVES CROSSING OUR FORECAST
AREA RESULTING IN ON AND OFF AGAIN SMALL CHANCES FOR SHOWERS AND
THUNDERSTORMS. TEMPERATURES WILL BE WARM FOR THIS TIME OF YEAR WITH
HIGHS IN THE 70S AND 80S THROUGHOUT THE PERIOD. NORMAL HIGHS ARE ONLY
IN THE MID TO UPPER 60S.
MONDAY NIGHT...SEVERAL OF THE THUNDERSTORMS THAT DEVELOP DURING THE
DAY ON MONDAY MAY PERSIST INTO THE EVENING/OVERNIGHT HOURS. A FEW OF
THESE THUNDERSTORMS MAY BE SEVERE...PRIMARILY SOUTH OF INTERSTATE 80.
TUESDAY...TEMPERATURES WARM WITH SOUTHERLY FLOW INTO THE 80S ACROSS
THE ENTIRE FORECAST AREA. THE ATMOSPHERE SHOULD BE PRETTY UNSTABLE BY
AFTERNOON AND A WEAK SHORT WAVE WILL BE MOVING ACROSS THE AREA. AM
ONLY GOING WITH A SLIGHT CHANCE OF THUNDERSTORMS DUE TO THE LIMITED
FORCING...BUT IF STORMS FORM THEY COULD CERTAINLY BE SEVERE GIVEN
APPRECIABLE DEEP LAYER SHEAR AND INSTABILITY.
WEDNESDAY INTO THURSDAY...A SFC FRONTAL BOUNDARY WILL STALL OUT
ACROSS OUR CWA AND MEANDER A BIT BACK AND FORTH ACROSS OUR CWA.
THERE WILL BE AT LEAST MODERATE INSTABILITY AND WITH WEAK UPPER
WAVES PASSING THROUGH WE COULD POP A FEW THUNDERSTORMS. WEAK DEEP
LAYER SHEAR MAY ACTUALLY BE ONE OF THE HINDERING FACTORS FOR SEVERE
WEATHER...BUT MODERATE INSTABILITY MAY BE ENOUGH TO ALLOW A FEW
STORM TO REACH SEVERE WEATHER THRESHOLDS SHOULD THEY FORM.
FRIDAY THROUGH SUNDAY. FRIDAY IS THE ONLY DRY DAY IN THE CURRENT
FORECAST AND EVEN THAT CAN NOT BE GUARANTEED. A STRONG UPPER LEVEL
TROUGH WILL BEGIN TO DEVELOP ACROSS THE WESTERN CONUS BY NEXT WEEKEND
AND WE COULD SEE A FEW CHANCES OF THUNDERSTORMS OUT AHEAD OF THIS
TROUGH...BUT BETTER CHANCES FOR THUNDERSTORMS MIGHT HOLD OFF UNTIL
JUST BEYOND THE END OF THIS FORECAST PERIOD.
&&
.PREV DISCUSSION... /ISSUED 1240 PM CDT SUN APR 29 2012/
AVIATION...18Z KGRI TAF. ALTHOUGH CONFIDENCE IN THE TIMING
DETAILS IS LOW...THERE IS INCREASING EVIDENCE THAT LIFR VISIBILITY
AND/OR CEILING WILL DEVELOP LATE TONIGHT INTO MONDAY
MORNING...SOMEWHAT SIMILAR TO WHAT HAPPENED THIS MORNING. STARTING
WITH THIS AFTERNOON...KGRI IS STARTING OUT WITH IFR CEILING/MVFR
VISIBILITY...BUT BASED ON TRENDS NOT FAR TO THE WEST...WILL
OPTIMISTICALLY CALL FOR A RETURN TO VFR CONDITIONS BY MID-LATE
AFTERNOON AS LOW CLOUDS SCATTER OUT. WILL KEEP VFR INTACT FOR MUCH
OF THE EVENING...BUT THEN AS WINDS BECOME LIGHT AND VARIABLE
OVERNIGHT AND BOUNDARY LAYER RELATIVE HUMIDITY REMAINS
HIGH...ANTICIPATE REDEVELOPMENT OF FOG AT SOME POINT. CERTAINLY
1/4SM VISIBILITY NOT OUT OF THE QUESTION...BUT WILL NOT OFFICIALLY
ADVERTISE QUITE THAT LOW YET. CONFIDENCE IS QUITE LOW ON WHAT
HAPPENS DURING THE LAST FEW HOURS OF THE PERIOD...BUT KEPT CEILING
NO BETTER THAN MVFR. AS FOR PRECIPITATION CHANCES...ALTHOUGH A
ROGUE SHOWER OR EVEN A THUNDERSTORM IS NOT COMPLETELY OUT OF THE
QUESTION LATER THIS AFTERNOON/EVENING AND AGAIN MONDAY
MORNING...THE LIKELIHOOD IS LOW ENOUGH TO NOT INSERT AT THIS TIME.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM/AVIATION...PFANNKUCH
LONG TERM...WESELY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1240 PM CDT SUN APR 29 2012
.AVIATION...18Z KGRI TAF. ALTHOUGH CONFIDENCE IN THE TIMING
DETAILS IS LOW...THERE IS INCREASING EVIDENCE THAT LIFR VISIBILITY
AND/OR CEILING WILL DEVELOP LATE TONIGHT INTO MONDAY
MORNING...SOMEWHAT SIMILAR TO WHAT HAPPENED THIS MORNING. STARTING
WITH THIS AFTERNOON...KGRI IS STARTING OUT WITH IFR CEILING/MVFR
VISIBILITY...BUT BASED ON TRENDS NOT FAR TO THE WEST...WILL
OPTIMISTICALLY CALL FOR A RETURN TO VFR CONDITIONS BY MID-LATE
AFTERNOON AS LOW CLOUDS SCATTER OUT. WILL KEEP VFR INTACT FOR MUCH
OF THE EVENING...BUT THEN AS WINDS BECOME LIGHT AND VARIABLE
OVERNIGHT AND BOUNDARY LAYER RELATIVE HUMIDITY REMAINS
HIGH...ANTICIPATE REDEVELOPMENT OF FOG AT SOME POINT. CERTAINLY
1/4SM VISIBILITY NOT OUT OF THE QUESTION...BUT WILL NOT OFFICIALLY
ADVERTISE QUITE THAT LOW YET. CONFIDENCE IS QUITE LOW ON WHAT
HAPPENS DURING THE LAST FEW HOURS OF THE PERIOD...BUT KEPT CEILING
NO BETTER THAN MVFR. AS FOR PRECIPITATION CHANCES...ALTHOUGH A
ROGUE SHOWER OR EVEN A THUNDERSTORM IS NOT COMPLETELY OUT OF THE
QUESTION LATER THIS AFTERNOON/EVENING AND AGAIN MONDAY
MORNING...THE LIKELIHOOD IS LOW ENOUGH TO NOT INSERT AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 1155 AM CDT SUN APR 29 2012/
UPDATE...JUST COMPLETED AN UPDATE FOR THIS AFTERNOON...ALTHOUGH
ADMITTEDLY CONFIDENCE IS A BIT LOW IN THE DETAILS. IN
SHORT...SPLIT THE LOW-END RISKS FOR A FEW THUNDERSTORMS INTO TWO
AREAS...ONE MAINLY EAST OF A YORK-OSBORNE LINE ASSOCIATED WITH THE
WEAK CONVECTION EVIDENT ON RADAR NOW AFFECTING THE HEBRON AREA AND
TIED TO AN EXITING SHORTWAVE...AND THE OTHER AREA FOR LATER THIS
AFTERNOON GENERALLY WEST OF AN ORD-PLAINVILLE LINE...WHERE BOTH
THE NAM/RUC ADVERTISE AT LEAST SEVERAL HUNDRED J/KG OF SBCAPE
DEVELOPING AS MODEST FORCING INCREASES AHEAD OF THE NEXT BATCH OF
SHORTWAVE ENERGY MOVING IN FROM THE WEST. ALTHOUGH NOT
ANTICIPATING SEVERE STORMS IN THE WESTERN AREA...COULD EASILY
FORESEE A FEW STRONG STORMS WITH DIME-NICKEL HAIL AND 50 MPH WIND
POTENTIAL. ALTHOUGH THE MAJORITY OF THE CWA WILL LIKELY REMAIN
DRY THIS AFTERNOON...DECIDED TO AT LEAST THROW A TOKEN SLIGHT
CHANCE OF A SPRINKLE ALL AREAS. OTHERWISE...CLOUD AND RESULTANT
TEMP TRENDS FOR THIS AFTERNOON ARE ALSO QUITE TRICKY. GENERAL
EXPECTATION IS THAT AT LEAST PARTIAL CLEARING WILL CONTINUE
WORKING INTO THE CWA FROM WEST-EAST...BUT WITH EASTERN AREAS
POSSIBLY STRUGGLING TO BREAK OUT OF LOW STRATUS EVEN BY LATER THIS
AFTERNOON. CURRENT SATELLITE IMAGERY REVEALS A BIT SHARPER
CLEARING LINE THAN EARLIER EXPECTED ACROSS THE WESTERN 1/2 OF THE
CWA. AS A RESULT...LEFT AFTERNOON HIGHS IN WESTERN COUNTIES
ESSENTIALLY UNCHANGED FROM PREVIOUS FORECAST...WITH MID-UPPER 60S.
HOWEVER...LOWERED EASTERN NEB ZONES A SOLID 2-4 DEGREES WITH SOME
PLACES POSSIBLY STRUGGLING TO REACH LOW 60S. IN BETWEEN...THE TRI-
CITIES ARE A TOUGH CALL...BUT WILL AIM FOR A 62-65 RANGE. NO
NOTABLE CHANGES MADE BEYOND THIS AFTERNOON YET.
PREV DISCUSSION... /ISSUED 835 AM CDT SUN APR 29 2012/
UPDATE...JUST STARTING TO GET A HANDLE ON TRENDS FOR TODAY...BUT
FIRST ORDER OF BUSINESS WAS UPDATING TO EXTEND COVERAGE OF FOG
WELL INTO THE MORNING HOURS...INCLUDING A MENTION OF PATCHY DENSE
FOG ACROSS A GOOD PERCENTAGE OF MAINLY THE CENTRAL/EASTERN CWA
BASED ON AUTOMATED OBS AND NDOR WEB CAMS. GLANCING AT BOUNDARY
LAYER RH PROGS FROM VARIOUS MODELS...LOW STRATUS AND FOG COULD BE
FAIRLY SLOW TO BURN OFF TODAY...ESPECIALLY ACROSS PARTS OF THE
SOUTHEAST 1/3 OR SO OF THE CWA. OBVIOUSLY THE LONGER FOG AND/OR
LOW STRATUS LINGERS...THE HARDER IT MAY BE TO REALIZE FORECAST
HIGHS IN THE MID-UPPER 60S...BUT NOT GOING TO MESS WITH INHERITED
TEMP FORECAST FOR AT LEAST A FEW MORE HOURS. ALSO NO CHANGES MADE
TO LOW-END AFTERNOON THUNDERSTORM CHANCES AT THIS TIME...ALTHOUGH
QUICK GLANCE AT 10Z HRRR AND 00Z 4KM WRF-NMM SUGGEST THE BEST
CHANCES WILL TARGET MAINLY THE WESTERN 1/3 OF THE CWA LATE THIS
AFTERNOON INTO THIS EVENING.
PREV DISCUSSION... /ISSUED 624 AM CDT SUN APR 29 2012/
AVIATION...12Z TAF. SOME LIGHT FOG/MIST HAS SPREAD INTO THE KGRI
TERMINAL AREA AND IS RESTRICTING VISIBILITIES. THE VISIBILITY
SHOULD IMPROVE AS THE LOWER STRATUS MOVES INTO THE AREA IN THE
NEXT HOUR OR SO. EITHER WAY THERE WILL BE IFR CONDITIONS ARE
EXPECTED. BY MID DAY VFR CONDITIONS ARE EXPECTED AGAIN AS THE
CLOUDS RECEDE FROM THE AREA. LATE TONIGHT EXPECT IFR CONDITIONS
AGAIN WITH LOW LEVEL MOISTURE AND LIGHT WINDS.
PREV DISCUSSION... /ISSUED 323 AM CDT SUN APR 29 2012/
SHORT TERM...TODAY THROUGH TUESDAY NIGHT. SMALL AREA OF LIGHT
SHOWERS/SPRINKLES OVER SOUTHWEST KS EARLY THIS MORNING SEEMS TO BE
ASSOCIATED WITH THE UPPER LEVEL JET DYNAMICS/DIFFLUENCE. DEPENDING
ON THE MODEL...ONE BRINGS THIS AREA OF SPRINKLES INTO OUR CWA
AROUND SUNRISE...THE OTHERS SUGGEST IT WILL STAY SOUTH. ALL THE
MODELS SHOW OUR CWA IN A RELATIVELY RAIN FREE AREA THROUGH TUESDAY
AFTERNOON. SEVERAL WEAK WAVES MOVING OVER THE AREA...SO EVEN
THOUGH CHANCES OF RAIN ARE LOW...THERE IS A CHANCE NONE THE LESS.
IN SHORT...TWEAKED PROBABILITY OF PRECIP AND A TEMP GRID HERE AND
THERE...BUT ON GOING FORECAST LOOKS FINE FOR NOW.
WILL HAVE TO WATCH FOR SOME POTENTIAL SEVERE WEATHER/THUNDERSTORM
DEVELOPMENT TUESDAY NIGHT THROUGH WEDNESDAY MORNING AS THERE IS
SOME INDICATION OF RAPID DESTABILIZATION OF THE ATMOSPHERE AS A
WARM FRONT MOVES INTO THE AREA. WILL NOT MENTION AT THIS TIME AS
CONFIDENCE IS LOW ALL THE INGREDIENTS WILL COME TOGETHER AS FORECAST.
MILD TEMPS TO CONTINUE THROUGH THE PERIOD. TODAY PROBABLY THE
COOLEST DAY THEN WARMING TO 10 TO 15 DEGREES ABOVE NORMAL BY MID WEEK.
LONG TERM...12Z WEDNESDAY THROUGH SATURDAY. MAIN FORECAST CONCERNS
WILL BE CHANCES FOR SHOWERS AND THUNDERSTORMS AND TEMPERATURES.
NEARLY ZONAL FLOW CONTINUES THROUGH THE PERIOD AND WITH IT THERE ARE
SEVERAL WAVES THAT MOVE THROUGH THE FLOW. MODELS CONTINUE TO HAVE
MINOR DIFFERENCES IN THE TIMING OF THESE WEAK WAVES AND THE SURFACE
SYSTEMS THAT MOVE THROUGH. THE LATEST RUNS OF THE MODELS HAVE A
SURFACE LOW AND COLD FRONT MOVING THROUGH WEDNESDAY NIGHT AND HAVE
KEPT A CHANCE FOR SHOWERS AND THUNDERSTORMS. WITHOUT A DEFINED
SURFACE BOUNDARY FOR THURSDAY THROUGH FRIDAY NIGHT HAVE KEPT DRY
CONDITIONS ACROSS THE AREA. BOTH THE GFS AND ECMWF DEVELOP ANOTHER
SURFACE LOW FOR SATURDAY MAINLY TO THE WEST OF THE FORECAST AREA.
WILL HAVE SOME CHANCES IN THE WEST/NORTHWEST. TEMPERATURES SHOULD BE
RATHER MILD WITH READINGS ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATES/AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1155 AM CDT SUN APR 29 2012
.UPDATE...JUST COMPLETED AN UPDATE FOR THIS AFTERNOON...ALTHOUGH
ADMITTEDLY CONFIDENCE IS A BIT LOW IN THE DETAILS. IN
SHORT...SPLIT THE LOW-END RISKS FOR A FEW THUNDERSTORMS INTO TWO
AREAS...ONE MAINLY EAST OF A YORK-OSBORNE LINE ASSOCIATED WITH THE
WEAK CONVECTION EVIDENT ON RADAR NOW AFFECTING THE HEBRON AREA AND
TIED TO AN EXITING SHORTWAVE...AND THE OTHER AREA FOR LATER THIS
AFTERNOON GENERALLY WEST OF AN ORD-PLAINVILLE LINE...WHERE BOTH
THE NAM/RUC ADVERTISE AT LEAST SEVERAL HUNDRED J/KG OF SBCAPE
DEVELOPING AS MODEST FORCING INCREASES AHEAD OF THE NEXT BATCH OF
SHORTWAVE ENERGY MOVING IN FROM THE WEST. ALTHOUGH NOT
ANTICIPATING SEVERE STORMS IN THE WESTERN AREA...COULD EASILY
FORESEE A FEW STRONG STORMS WITH DIME-NICKEL HAIL AND 50 MPH WIND
POTENTIAL. ALTHOUGH THE MAJORITY OF THE CWA WILL LIKELY REMAIN
DRY THIS AFTERNOON...DECIDED TO AT LEAST THROW A TOKEN SLIGHT
CHANCE OF A SPRINKLE ALL AREAS. OTHERWISE...CLOUD AND RESULTANT
TEMP TRENDS FOR THIS AFTERNOON ARE ALSO QUITE TRICKY. GENERAL
EXPECTATION IS THAT AT LEAST PARTIAL CLEARING WILL CONTINUE
WORKING INTO THE CWA FROM WEST-EAST...BUT WITH EASTERN AREAS
POSSIBLY STRUGGLING TO BREAK OUT OF LOW STRATUS EVEN BY LATER THIS
AFTERNOON. CURRENT SATELLITE IMAGERY REVEALS A BIT SHARPER
CLEARING LINE THAN EARLIER EXPECTED ACROSS THE WESTERN 1/2 OF THE
CWA. AS A RESULT...LEFT AFTERNOON HIGHS IN WESTERN COUNTIES
ESSENTIALLY UNCHANGED FROM PREVIOUS FORECAST...WITH MID-UPPER 60S.
HOWEVER...LOWERED EASTERN NEB ZONES A SOLID 2-4 DEGREES WITH SOME
PLACES POSSIBLY STRUGGLING TO REACH LOW 60S. IN BETWEEN...THE TRI-
CITIES ARE A TOUGH CALL...BUT WILL AIM FOR A 62-65 RANGE. NO
NOTABLE CHANGES MADE BEYOND THIS AFTERNOON YET.
&&
.PREV DISCUSSION... /ISSUED 835 AM CDT SUN APR 29 2012/
UPDATE...JUST STARTING TO GET A HANDLE ON TRENDS FOR TODAY...BUT
FIRST ORDER OF BUSINESS WAS UPDATING TO EXTEND COVERAGE OF FOG
WELL INTO THE MORNING HOURS...INCLUDING A MENTION OF PATCHY DENSE
FOG ACROSS A GOOD PERCENTAGE OF MAINLY THE CENTRAL/EASTERN CWA
BASED ON AUTOMATED OBS AND NDOR WEB CAMS. GLANCING AT BOUNDARY
LAYER RH PROGS FROM VARIOUS MODELS...LOW STRATUS AND FOG COULD BE
FAIRLY SLOW TO BURN OFF TODAY...ESPECIALLY ACROSS PARTS OF THE
SOUTHEAST 1/3 OR SO OF THE CWA. OBVIOUSLY THE LONGER FOG AND/OR
LOW STRATUS LINGERS...THE HARDER IT MAY BE TO REALIZE FORECAST
HIGHS IN THE MID-UPPER 60S...BUT NOT GOING TO MESS WITH INHERITED
TEMP FORECAST FOR AT LEAST A FEW MORE HOURS. ALSO NO CHANGES MADE
TO LOW-END AFTERNOON THUNDERSTORM CHANCES AT THIS TIME...ALTHOUGH
QUICK GLANCE AT 10Z HRRR AND 00Z 4KM WRF-NMM SUGGEST THE BEST
CHANCES WILL TARGET MAINLY THE WESTERN 1/3 OF THE CWA LATE THIS
AFTERNOON INTO THIS EVENING.
PREV DISCUSSION... /ISSUED 624 AM CDT SUN APR 29 2012/
AVIATION...12Z TAF. SOME LIGHT FOG/MIST HAS SPREAD INTO THE KGRI
TERMINAL AREA AND IS RESTRICTING VISIBILITIES. THE VISIBILITY
SHOULD IMPROVE AS THE LOWER STRATUS MOVES INTO THE AREA IN THE
NEXT HOUR OR SO. EITHER WAY THERE WILL BE IFR CONDITIONS ARE
EXPECTED. BY MID DAY VFR CONDITIONS ARE EXPECTED AGAIN AS THE
CLOUDS RECEDE FROM THE AREA. LATE TONIGHT EXPECT IFR CONDITIONS
AGAIN WITH LOW LEVEL MOISTURE AND LIGHT WINDS.
PREV DISCUSSION... /ISSUED 323 AM CDT SUN APR 29 2012/
SHORT TERM...TODAY THROUGH TUESDAY NIGHT. SMALL AREA OF LIGHT
SHOWERS/SPRINKLES OVER SOUTHWEST KS EARLY THIS MORNING SEEMS TO BE
ASSOCIATED WITH THE UPPER LEVEL JET DYNAMICS/DIFFLUENCE. DEPENDING
ON THE MODEL...ONE BRINGS THIS AREA OF SPRINKLES INTO OUR CWA
AROUND SUNRISE...THE OTHERS SUGGEST IT WILL STAY SOUTH. ALL THE
MODELS SHOW OUR CWA IN A RELATIVELY RAIN FREE AREA THROUGH TUESDAY
AFTERNOON. SEVERAL WEAK WAVES MOVING OVER THE AREA...SO EVEN
THOUGH CHANCES OF RAIN ARE LOW...THERE IS A CHANCE NONE THE LESS.
IN SHORT...TWEAKED PROBABILITY OF PRECIP AND A TEMP GRID HERE AND
THERE...BUT ON GOING FORECAST LOOKS FINE FOR NOW.
WILL HAVE TO WATCH FOR SOME POTENTIAL SEVERE WEATHER/THUNDERSTORM
DEVELOPMENT TUESDAY NIGHT THROUGH WEDNESDAY MORNING AS THERE IS
SOME INDICATION OF RAPID DESTABILIZATION OF THE ATMOSPHERE AS A
WARM FRONT MOVES INTO THE AREA. WILL NOT MENTION AT THIS TIME AS
CONFIDENCE IS LOW ALL THE INGREDIENTS WILL COME TOGETHER AS FORECAST.
MILD TEMPS TO CONTINUE THROUGH THE PERIOD. TODAY PROBABLY THE
COOLEST DAY THEN WARMING TO 10 TO 15 DEGREES ABOVE NORMAL BY MID WEEK.
LONG TERM...12Z WEDNESDAY THROUGH SATURDAY. MAIN FORECAST CONCERNS
WILL BE CHANCES FOR SHOWERS AND THUNDERSTORMS AND TEMPERATURES.
NEARLY ZONAL FLOW CONTINUES THROUGH THE PERIOD AND WITH IT THERE ARE
SEVERAL WAVES THAT MOVE THROUGH THE FLOW. MODELS CONTINUE TO HAVE
MINOR DIFFERENCES IN THE TIMING OF THESE WEAK WAVES AND THE SURFACE
SYSTEMS THAT MOVE THROUGH. THE LATEST RUNS OF THE MODELS HAVE A
SURFACE LOW AND COLD FRONT MOVING THROUGH WEDNESDAY NIGHT AND HAVE
KEPT A CHANCE FOR SHOWERS AND THUNDERSTORMS. WITHOUT A DEFINED
SURFACE BOUNDARY FOR THURSDAY THROUGH FRIDAY NIGHT HAVE KEPT DRY
CONDITIONS ACROSS THE AREA. BOTH THE GFS AND ECMWF DEVELOP ANOTHER
SURFACE LOW FOR SATURDAY MAINLY TO THE WEST OF THE FORECAST AREA.
WILL HAVE SOME CHANCES IN THE WEST/NORTHWEST. TEMPERATURES SHOULD BE
RATHER MILD WITH READINGS ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATES...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
835 AM CDT SUN APR 29 2012
.UPDATE...JUST STARTING TO GET A HANDLE ON TRENDS FOR TODAY...BUT
FIRST ORDER OF BUSINESS WAS UPDATING TO EXTEND COVERAGE OF FOG
WELL INTO THE MORNING HOURS...INCLUDING A MENTION OF PATCHY DENSE
FOG ACROSS A GOOD PERCENTAGE OF MAINLY THE CENTRAL/EASTERN CWA
BASED ON AUTOMATED OBS AND NDOR WEB CAMS. GLANCING AT BOUNDARY
LAYER RH PROGS FROM VARIOUS MODELS...LOW STRATUS AND FOG COULD BE
FAIRLY SLOW TO BURN OFF TODAY...ESPECIALLY ACROSS PARTS OF THE
SOUTHEAST 1/3 OR SO OF THE CWA. OBVIOUSLY THE LONGER FOG AND/OR
LOW STRATUS LINGERS...THE HARDER IT MAY BE TO REALIZE FORECAST
HIGHS IN THE MID-UPPER 60S...BUT NOT GOING TO MESS WITH INHERITED
TEMP FORECAST FOR AT LEAST A FEW MORE HOURS. ALSO NO CHANGES MADE
TO LOW-END AFTERNOON THUNDERSTORM CHANCES AT THIS TIME...ALTHOUGH
QUICK GLANCE AT 10Z HRRR AND 00Z 4KM WRF-NMM SUGGEST THE BEST
CHANCES WILL TARGET MAINLY THE WESTERN 1/3 OF THE CWA LATE THIS
AFTERNOON INTO THIS EVENING.
&&
.PREV DISCUSSION... /ISSUED 624 AM CDT SUN APR 29 2012/
AVIATION...12Z TAF. SOME LIGHT FOG/MIST HAS SPREAD INTO THE KGRI
TERMINAL AREA AND IS RESTRICTING VISIBILITIES. THE VISIBILITY
SHOULD IMPROVE AS THE LOWER STRATUS MOVES INTO THE AREA IN THE
NEXT HOUR OR SO. EITHER WAY THERE WILL BE IFR CONDITIONS ARE
EXPECTED. BY MID DAY VFR CONDITIONS ARE EXPECTED AGAIN AS THE
CLOUDS RECEDE FROM THE AREA. LATE TONIGHT EXPECT IFR CONDITIONS
AGAIN WITH LOW LEVEL MOISTURE AND LIGHT WINDS.
PREV DISCUSSION... /ISSUED 323 AM CDT SUN APR 29 2012/
SHORT TERM...TODAY THROUGH TUESDAY NIGHT. SMALL AREA OF LIGHT
SHOWERS/SPRINKLES OVER SOUTHWEST KS EARLY THIS MORNING SEEMS TO BE
ASSOCIATED WITH THE UPPER LEVEL JET DYNAMICS/DIFFLUENCE. DEPENDING
ON THE MODEL...ONE BRINGS THIS AREA OF SPRINKLES INTO OUR CWA
AROUND SUNRISE...THE OTHERS SUGGEST IT WILL STAY SOUTH. ALL THE
MODELS SHOW OUR CWA IN A RELATIVELY RAIN FREE AREA THROUGH TUESDAY
AFTERNOON. SEVERAL WEAK WAVES MOVING OVER THE AREA...SO EVEN
THOUGH CHANCES OF RAIN ARE LOW...THERE IS A CHANCE NONE THE LESS.
IN SHORT...TWEAKED PROBABILITY OF PRECIP AND A TEMP GRID HERE AND
THERE...BUT ON GOING FORECAST LOOKS FINE FOR NOW.
WILL HAVE TO WATCH FOR SOME POTENTIAL SEVERE WEATHER/THUNDERSTORM
DEVELOPMENT TUESDAY NIGHT THROUGH WEDNESDAY MORNING AS THERE IS
SOME INDICATION OF RAPID DESTABILIZATION OF THE ATMOSPHERE AS A
WARM FRONT MOVES INTO THE AREA. WILL NOT MENTION AT THIS TIME AS
CONFIDENCE IS LOW ALL THE INGREDIENTS WILL COME TOGETHER AS FORECAST.
MILD TEMPS TO CONTINUE THROUGH THE PERIOD. TODAY PROBABLY THE
COOLEST DAY THEN WARMING TO 10 TO 15 DEGREES ABOVE NORMAL BY MID WEEK.
LONG TERM...12Z WEDNESDAY THROUGH SATURDAY. MAIN FORECAST CONCERNS
WILL BE CHANCES FOR SHOWERS AND THUNDERSTORMS AND TEMPERATURES.
NEARLY ZONAL FLOW CONTINUES THROUGH THE PERIOD AND WITH IT THERE ARE
SEVERAL WAVES THAT MOVE THROUGH THE FLOW. MODELS CONTINUE TO HAVE
MINOR DIFFERENCES IN THE TIMING OF THESE WEAK WAVES AND THE SURFACE
SYSTEMS THAT MOVE THROUGH. THE LATEST RUNS OF THE MODELS HAVE A
SURFACE LOW AND COLD FRONT MOVING THROUGH WEDNESDAY NIGHT AND HAVE
KEPT A CHANCE FOR SHOWERS AND THUNDERSTORMS. WITHOUT A DEFINED
SURFACE BOUNDARY FOR THURSDAY THROUGH FRIDAY NIGHT HAVE KEPT DRY
CONDITIONS ACROSS THE AREA. BOTH THE GFS AND ECMWF DEVELOP ANOTHER
SURFACE LOW FOR SATURDAY MAINLY TO THE WEST OF THE FORECAST AREA.
WILL HAVE SOME CHANCES IN THE WEST/NORTHWEST. TEMPERATURES SHOULD BE
RATHER MILD WITH READINGS ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1133 PM EDT MON APR 30 2012
.SYNOPSIS...
A WARM FRONT WILL LIFT ACROSS NEW YORK FROM THE OHIO VALLEY THIS EVENING
WITH SOME SHOWERS AND AN ISOLATED THUNDERSTORM OR TWO. A COLD
FRONT WILL CROSS THE REGION LATE TONIGHT WITH ANOTHER ROUND OF
SHOWERS. CONDITIONS WILL THEN BECOME NOTABLY WARMER BUT UNSETTLED
ACROSS THE REGION TUESDAY THROUGH THE REMAINDER OF THE WEEK AS
TEMPERATURES WILL CLIMB WELL ABOVE NORMAL.
&&
.NEAR TERM /THROUGH TUESDAY/...
A BROAD AREA OF LOW PRESSURE WILL LIFT TO THE NORTHEAST ACROSS
WESTERN NEW YORK OVERNIGHT. SHOWERS HAVE SPREAD INTO WESTERN NEW
YORK LATE THIS EVENING...WITH THESE SHOWERS FORECAST TO CONTINUE
TO MOVE ACROSS THE REGION OVERNIGHT. THE HRRR IN PARTICULAR HAS BEEN
QUITE CONSISTENT IN BRINGING SHOWERS ACROSS WESTERN NEW YORK
TONIGHT THROUGH 10Z...WITH RUNS OF THE NAM/RGEM ALSO SIMILAR BUT
PERHAPS A TAD SLOW. RADAR TRENDS ARE IN GENERAL SUPPORT OF THIS
CONSENSUS...AND ARE WELL CAPTURED BY ALL OF THESE MODELS...THE
HRRR IN PARTICULAR. ALSO...EXPECT SOME LIGHTNING WILL REACH
WESTERN NEW YORK WITH THIS AS WELL...THOUGH SURFACE BASED
CONVECTION SHOULD REMAIN TO THE SOUTH...WITH ELEVATED CONVECTION
ACROSS WESTERN NEW YORK SUPPORTING A MINIMAL (TO NIL) SEVERE
WEATHER THREAT. THIS SAID...EXPECT SHOWERS TO BRING A HALF INCH OR
SO OF RAIN TO SOUTHERN PORTIONS OF THE CWA...WITH LOCALLY HIGHER
AMOUNTS POSSIBLE IN THUNDERSTORMS. THE BEST CHANCE FOR
THUNDERSTORMS AND HIGHER QPF IN THE INCH RANGE APPEAR TO BE ACROSS
WESTERN PORTIONS OF THE SOUTHERN TIER...FOLLOWING BOTH HRRR
FORECASTS AND RADAR TRENDS.
OTHERWISE...TEMPERATURES WILL REMAIN MILD WITH WARMER AIR
SHIFTING ACROSS THE REGION WITHIN THE LOW PRESSURE SYSTEMS WARM
SECTOR. TEMPS WILL NOT FALL MUCH OVERNIGHT AND MAY IN FACT REMAIN
STEADY OR RISE. SOUTH I-90 WHERE WINDS HAVE GONE TO THE SE BEHIND
THE WARM FRONT...HEDGE ON THE WARM SIDE OF MOS GUIDANCE...WITH
STEADY TEMPERATURES IN THE 50S LIKELY OVERNIGHT.
TUESDAY...FRONT MAY STILL BE PRESSING EAST ACROSS CENTRAL AND
NORTHERN NEW YORK TUESDAY MORNING WITH CHANCES FOR SHOWERS. ALL
AREAS SHOULD BE DRY BY THE AFTERNOON WITH A WEAK HIGH PRESSURE
BUILDING IN BEHIND THE FRONT. MOST AREAS WILL TURN OUT PARTLY TO
MOSTLY SUNNY BY AFTERNOON. HIGHS LOOK TO REACH INTO THE LOW 60S
ESPECIALLY ACROSS WESTERN NEW YORK WHERE THE SUN WILL BREAK OUT
EARLIER THAN CENTRAL AND NORTHERN NY.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
WE WILL SEE A QUIET START TO THE PERIOD AS WESTERN AND CENTRAL NEW
YORK WILL BE FALLING UNDER THE INFLUENCE OF A BROAD UPPER LEVEL
RIDGE UPSTREAM. SUBSIDENCE OVER THE REGION SHOULD ALLOW FOR MOSTLY
CLEAR SKIES. THIS COMBINED WITH LIGHT WINDS SHOULD ALLOW FOR
TEMPERATURES TO DROP INTO THE UPPER 40S WITH MID 40S IN THE USUAL
COOL SPOTS OF THE SOUTHERN/TIER AND NORTH COUNTRY.
WEDNESDAY WILL FEATURE THE BEGINNING OF THE PRONOUNCED WARM-UP THAT
WILL BE AFFECTING THE REGION THROUGH THE REST OF THE WEEK. THE BROAD
UPPER LEVEL RIDGE WILL SETTLE OVER THE EASTERN UNITED STATES WHILE
RETURN FLOW AROUND A STRONG SURFACE HIGH ANCHORED OFF THE SOUTHEAST
U.S. COAST WILL PUMP INCREASINGLY WARM AND MOIST AIR NORTHWARDS
ACROSS THE OHIO VALLEY AND INTO THE GREAT LAKES REGION. THIS WILL
RESULT IN TEMPERATURES THAT WILL RISE WELL INTO THE 70S WEDNESDAY
AND THURSDAY WITH SOME AREAS POSSIBLY BREACHING 80 ON THURSDAY. IN
ADDITION TO THE WARMTH...IT WILL START TO FEEL MUGGY AS WELL AS
SURFACE DEW POINTS WILL ALSO RISE INTO 50S WEDNESDAY AND POSSIBLY LOW
60S THURSDAY AS THE RICH GULF MOISTURE SURGES NORTHWARDS.
WITH THE WARM AND MOIST AIR ADVECTING NORTH INTO THE REGION...WE
INTRODUCE THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS. THE GREATEST
POTENTIAL FOR CONVECTION ON WEDNESDAY WILL BE FOUND ACROSS
FAR WESTERN NEW YORK DURING LATE AFTERNOON AS THE LEADING EDGE OF A
THETA-E RIDGE SLIDES INTO THE NIAGARA FRONTIER. THE THREAT FOR
CONVECTION CONTINUES INTO WEDNESDAY NIGHT AS MODELS INDICATE ML CAPE
VALUES OF AROUND 400 J/KG WEST OF THE GENESEE VALLEY.
CONDITIONS THURSDAY SHOULD BE RIPE FOR SHOWERS AND THUNDERSTORMS AS
WE WILL REMAIN IN A VERY MOIST AIRMASS...HOWEVER WITH LIGHT FLOW AND
A LACK OF A CLEAR TRIGGER SUCH AS A SHORTWAVE...AM NOT EXPECTING
ORGANIZED OR SEVERE CONVECTION. HOWEVER MAY SEE WIDESPREAD
LAKE-BREEZE INDUCED SHOWERS/THUNDERSTORMS...PARTICULARLY INT HE
AFTERNOON/EVENING HOURS. THE FLY IN THE OINTMENT MAY BE WEAK
MID-LEVEL LAPSE RATES THAT MAY PUT A LID ON CONVECTION FROM BREAKING
OUT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
EXPECT MUCH OF THE SAME ON FRIDAY AS THE VERY WARM/MOIST AND
UNSTABLE AIRMASS LINGERS OVER THE REGION WITH HIGHS IN THE 70S AND
AT LEAST A CHANCE OF SHOWERS AND THUNDERSTORMS. THE FORECAST BECOMES
MURKIER BY THE WEEKEND WITH THE MODELS AT ODDS OVER THE
LOCATION/TIMING OF A COLD FRONT SWEEPING SOUTH OUT OF CANADA. THE
GFS PUSHES THE FRONT ACROSS THE FORECAST AREA SATURDAY...A PROSPECT
THAT WOULD RESULT IN A MUCH COOLER/DRIER WEEKEND THAN CURRENTLY
FORECAST. THE ECMWF...ON THE OTHER HAND...PUSHES A MUCH WEAKER
FRONT ACROSS THE REGION LATE ON SUNDAY. GIVEN THESE
DIFFERENCES...WILL OPT FOR A FORECAST THAT LEANS MORE TOWARDS THE
ECMWF/PERSISTENCE WITH HIGHS IN THE LOW 70S...LOWS IN THE 50S...AND
CHANCE POPS.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
A MODEST LOW LEVEL JET OF 30 TO 40 KTS WILL EXIT FROM WEST TO EAST
AFTER MIDNIGHT. WHILE SHOWERS WILL BE HEAVY AT TIMES...BETWEEN
SHOWERS EXPECT VFR CONDITIONS AS A SE FLOW WILL LARGELY KEEP CIGS
IN THAT RANGE. THIS SAID...SOME SHOWERS WILL BE HEAVY...SOME WITH
EMBEDDED THUNDERSTORMS. THIS MAY BRIEFLY LOWER VSBY TO 2SM OR LESS
IN RAIN...HOWEVER THIS WOULD BE SHORT LIVED AT ANY ONE LOCATION
THOROUGH THE EARLY MORNING HOURS.
WINDS WILL SHIFT TO THE NW BEHIND THE SYSTEM LATE TONIGHT...WHICH
WILL LIKELY LOWER CIGS TO IFR OR LOWER FOR A PERIOD. PATCHY FOG IS
ALSO POSSIBLE. CONDITIONS SHOULD GRADUALLY IMPROVE TO VFR DURING
THE DAY TUESDAY AS THE LOW LAYERS DRY OUT.
OUTLOOK...
TUESDAY NIGHT...VFR.
WEDNESDAY THROUGH SATURDAY...VFR/MVFR IN SHOWERS.
&&
.MARINE...
WINDS AND WAVES WILL REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA
DURING THIS PERIOD...ALTHOUGH MORE ACTIVE WEATHER CAN BE EXPECTED.
A WARM FRONT IS LIFTING ACROSS THE LOWER GREAT LAKES FROM THE OHIO VALLEY
TODAY. THIS WILL PRODUCE GENTLE TO OCCASIONALLY MODERATE EASTERLIES
ON LAKES ERIE AND ONTARIO...THEN AS THE WARM FRONT AND ITS SHOWERS
MOVE THROUGH THIS AFTERNOON AND EVENING WINDS WILL BECOME MORE
SOUTHEASTERLY. OVERNIGHT A SURFACE LOW WILL SHIFT EAST ACROSS LAKE ONTARIO
WITH WINDS SHIFTING TO SOUTHWEST BY TUESDAY MORNING. EXPECT LIGHT
WINDS AND NEGLIGIBLE WAVES THROUGH TUESDAY NIGHT.
&&
.CLIMATE...
THIS CHILLY SUNDAY MORNING SAW BUFFALO SET A NEW RECORD LOW
TEMPERATURE WITH THE 28 DEGREE READING BREAKING THE OLD RECORD OF
29. THIS IS THE FIRST TIME A RECORD LOW MINIMUM TEMPERATURE HAS
BEEN SET AT THE BUFFALO AIRPORT SINCE MARCH 6 2007.
ROCHESTER NEW YORK ALSO TIED A RECORD LOW THIS MORNING...THE 27
DEGREES TIED THE RECORD LOW VALUE. THIS IS THE FIRST TIME A RECORD
LOW MINIMUM WAS EITHER SET OR TIED AT ROCHESTER SINCE JULY 14 2009.
BUFFALO AND ROCHESTER WILL ALSO HAVE POTENTIAL FOR THEIR FIRST BELOW
NORMAL TEMPERATURE MONTH SINCE MARCH 2011. BOTH BUFFALO AND
ROCHESTER WITH HELP OF THE LAST 10 DAYS OF APRIL BELOW NORMAL MAY
JUST END FINISHING UP A FEW TENTHS OF A DEGREE BELOW NORMAL FOR
APRIL. FINAL STATISTICS WILL BE CALCULATED AFTER THE MONTH
FINISHES.
APRIL`S MONTHLY TEMPERATURE DEPARTURE IS A DRASTIC DIFFERENCE FROM
MARCH 2012 WHEN BOTH CITIES HAD A SIGNIFICANTLY ABOVE NORMAL
TEMPERATURE DEPARTURE. ONLY ONCE IN RECORDED HISTORY HAS THERE BEEN
A COOLER APRIL THAN MARCH AND THAT OCCURRED FOR BUFFALO BACK IN 1946.
THERE IS GOOD POTENTIAL FOR BOTH CITIES TO HAVE A COOLER APRIL
THAN MARCH IN 2012. THROUGH THE 28TH OF APRIL BUFFALO`S AVERAGE
APRIL TEMPERATURE IS 2.1 DEGREES COOLER THAN THE AVERAGE
TEMPERATURE RECORDED IN MARCH 2012. FOR ROCHESTER...WHICH HAS BEEN
SLIGHTLY WARMER THIS MONTH THROUGH THE SAME TIME SPAN...APRIL 2012
HAS BEEN 1.2 DEGREES COOLER THAN MARCH 2012.
BELOW ARE THE YEARS AND TOP FIVE LOWEST SPREADS BETWEEN APRIL
AVERAGE TEMPERATURE AND MARCH AVERAGE TEMPERATURE.
BUFFALO
YEAR APRIL AVG TEMPERATURE MINUS MARCH AVG TEMPERATURE
1946 -0.1
1898 2.3
1907 2.9
1903 3.0
1920 3.8
ROCHESTER
YEAR APRIL AVG TEMPERATURE MINUS MARCH AVG TEMPERATURE
1898 0.8
1946 1.2
1907 2.8
1903 3.0
1995 3.1
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...APFFEL/SMITH
SHORT TERM...WOOD
LONG TERM...WOOD
AVIATION...APFFEL
MARINE...APFFEL/SMITH/WOOD
CLIMATE...THOMAS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1004 PM EDT MON APR 30 2012
.SYNOPSIS...
A WARM FRONT WILL LIFT ACROSS NEW YORK FROM THE OHIO VALLEY THIS EVENING
WITH SOME SHOWERS AND AN ISOLATED THUNDERSTORM OR TWO. A COLD
FRONT WILL CROSS THE REGION LATE TONIGHT WITH ANOTHER ROUND OF
SHOWERS. CONDITIONS WILL THEN BECOME NOTABLY WARMER BUT UNSETTLED
ACROSS THE REGION TUESDAY THROUGH THE REMAINDER OF THE WEEK AS
TEMPERATURES WILL CLIMB WELL ABOVE NORMAL.
&&
.NEAR TERM /THROUGH TUESDAY/...
A BROAD AREA OF LOW PRESSURE LOOSELY CENTERED ACROSS OHIO THIS
EVENING WILL LIFT TO THE NORTHEAST ACROSS WESTERN NEW YORK
TONIGHT.
MEANWHILE...THE MAIN AREA OF SHOWERS WILL CONTINUE TO SPREAD INTO
THE REGION LATE THIS EVENING. THE 18Z NAM/12Z RGEM/HRRR HAVE BEEN QUITE
CONSISTENT IN BRINGING SHOWERS ACROSS WESTERN NEW YORK TONIGHT
THROUGH 10Z. RADAR TRENDS ARE IN GENERAL SUPPORT OF THIS
CONSENSUS...AND ARE WELL CAPTURED BY ALL THREE OF THESE
MODELS...THE HRRR IN PARTICULAR. ALSO...EXPECT SOME LIGHTNING
WILL REACH WESTERN NEW YORK WITH THIS AS WELL...THOUGH SURFACE
BASED CONVECTION SHOULD REMAIN TO THE SOUTH...WITH ELEVATED
CONVECTION ACROSS WESTERN NEW YORK SUPPORTING A MINIMAL (TO NIL)
SEVERE WEATHER THREAT. THIS SAID...EXPECT SHOWERS TO BRING A HALF
INCH OR SO OF RAIN TO SOUTHERN PORTIONS OF THE CWA...WITH LOCALLY
HIGHER AMOUNTS POSSIBLE IN THUNDERSTORMS. THE BEST CHANCE FOR
THUNDERSTORMS AND HIGHER QPF IN THE INCH RANGE APPEAR TO BE ACROSS
WESTERN PORTIONS OF THE SOUTHERN TIER...FOLLOWING BOTH HRRR
FORECASTS AND RADAR TRENDS.
OTHERWISE...TEMPERATURES WILL REMAIN MILD WITH WARMER AIR
SHIFTING ACROSS THE REGION WITHIN THE LOW PRESSURE SYSTEMS WARM
SECTOR. TEMPS WILL NOT FALL MUCH OVERNIGHT AND MAY IN FACT REMAIN
STEADY OR RISE. SOUTH I-90 WHERE WINDS HAVE GONE TO THE SE BEHIND
THE WARM FRONT...HEDGE ON THE WARM SIDE OF MOS GUIDANCE...WITH
STEADY TEMPERATURES IN THE 50S LIKELY OVERNIGHT.
TUESDAY...FRONT MAY STILL BE PRESSING EAST ACROSS CENTRAL AND
NORTHERN NEW YORK TUESDAY MORNING WITH CHANCES FOR SHOWERS. ALL
AREAS SHOULD BE DRY BY THE AFTERNOON WITH A WEAK HIGH PRESSURE
BUILDING IN BEHIND THE FRONT. MOST AREAS WILL TURN OUT PARTLY TO
MOSTLY SUNNY BY AFTERNOON. HIGHS LOOK TO REACH INTO THE LOW 60S
ESPECIALLY ACROSS WESTERN NEW YORK WHERE THE SUN WILL BREAK OUT
EARLIER THAN CENTRAL AND NORTHERN NY.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
WE WILL SEE A QUIET START TO THE PERIOD AS WESTERN AND CENTRAL NEW
YORK WILL BE FALLING UNDER THE INFLUENCE OF A BROAD UPPER LEVEL
RIDGE UPSTREAM. SUBSIDENCE OVER THE REGION SHOULD ALLOW FOR MOSTLY
CLEAR SKIES. THIS COMBINED WITH LIGHT WINDS SHOULD ALLOW FOR
TEMPERATURES TO DROP INTO THE UPPER 40S WITH MID 40S IN THE USUAL
COOL SPOTS OF THE SOUTHERN/TIER AND NORTH COUNTRY.
WEDNESDAY WILL FEATURE THE BEGINNING OF THE PRONOUNCED WARM-UP THAT
WILL BE AFFECTING THE REGION THROUGH THE REST OF THE WEEK. THE BROAD
UPPER LEVEL RIDGE WILL SETTLE OVER THE EASTERN UNITED STATES WHILE
RETURN FLOW AROUND A STRONG SURFACE HIGH ANCHORED OFF THE SOUTHEAST
U.S. COAST WILL PUMP INCREASINGLY WARM AND MOIST AIR NORTHWARDS
ACROSS THE OHIO VALLEY AND INTO THE GREAT LAKES REGION. THIS WILL
RESULT IN TEMPERATURES THAT WILL RISE WELL INTO THE 70S WEDNESDAY
AND THURSDAY WITH SOME AREAS POSSIBLY BREACHING 80 ON THURSDAY. IN
ADDITION TO THE WARMTH...IT WILL START TO FEEL MUGGY AS WELL AS
SURFACE DEW POINTS WILL ALSO RISE INTO 50S WEDNESDAY AND POSSIBLY LOW
60S THURSDAY AS THE RICH GULF MOISTURE SURGES NORTHWARDS.
WITH THE WARM AND MOIST AIR ADVECTING NORTH INTO THE REGION...WE
INTRODUCE THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS. THE GREATEST
POTENTIAL FOR CONVECTION ON WEDNESDAY WILL BE FOUND ACROSS
FAR WESTERN NEW YORK DURING LATE AFTERNOON AS THE LEADING EDGE OF A
THETA-E RIDGE SLIDES INTO THE NIAGARA FRONTIER. THE THREAT FOR
CONVECTION CONTINUES INTO WEDNESDAY NIGHT AS MODELS INDICATE ML CAPE
VALUES OF AROUND 400 J/KG WEST OF THE GENESEE VALLEY.
CONDITIONS THURSDAY SHOULD BE RIPE FOR SHOWERS AND THUNDERSTORMS AS
WE WILL REMAIN IN A VERY MOIST AIRMASS...HOWEVER WITH LIGHT FLOW AND
A LACK OF A CLEAR TRIGGER SUCH AS A SHORTWAVE...AM NOT EXPECTING
ORGANIZED OR SEVERE CONVECTION. HOWEVER MAY SEE WIDESPREAD
LAKE-BREEZE INDUCED SHOWERS/THUNDERSTORMS...PARTICULARLY INT HE
AFTERNOON/EVENING HOURS. THE FLY IN THE OINTMENT MAY BE WEAK
MID-LEVEL LAPSE RATES THAT MAY PUT A LID ON CONVECTION FROM BREAKING
OUT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
EXPECT MUCH OF THE SAME ON FRIDAY AS THE VERY WARM/MOIST AND
UNSTABLE AIRMASS LINGERS OVER THE REGION WITH HIGHS IN THE 70S AND
AT LEAST A CHANCE OF SHOWERS AND THUNDERSTORMS. THE FORECAST BECOMES
MURKIER BY THE WEEKEND WITH THE MODELS AT ODDS OVER THE
LOCATION/TIMING OF A COLD FRONT SWEEPING SOUTH OUT OF CANADA. THE
GFS PUSHES THE FRONT ACROSS THE FORECAST AREA SATURDAY...A PROSPECT
THAT WOULD RESULT IN A MUCH COOLER/DRIER WEEKEND THAN CURRENTLY
FORECAST. THE ECMWF...ON THE OTHER HAND...PUSHES A MUCH WEAKER
FRONT ACROSS THE REGION LATE ON SUNDAY. GIVEN THESE
DIFFERENCES...WILL OPT FOR A FORECAST THAT LEANS MORE TOWARDS THE
ECMWF/PERSISTENCE WITH HIGHS IN THE LOW 70S...LOWS IN THE 50S...AND
CHANCE POPS.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
FOR THIS EVENING...EXPECT SCATTERED SHOWERS ACROSS THE
REGION...WITH PRIMARILY VFR CONDITIONS OUTSIDE OF LOCALLY AND
BRIEF HEAVIER RAIN SHOWERS. THE 00Z BUFFALO SOUNDING CONFIRMS
MODEL FORECASTS...WITH WINDS AT 2000 FEET OF ABOUT 30 KTS OUT OF
THE SE. ALTHOUGH SPEED DIFFERENCE IS MODEST...THERE IS A DRASTIC
DIFFERENCE IN DIRECTION...SO WILL CARRY LLWS FOR A PERIOD AT ALL
TAF LOCATIONS UNTIL THESE WINDS ALOFT DECREASE LATER TONIGHT.
EXPECT THE MAIN AREA OF SHOWERS TO MOVE ACROSS BETWEEN 04Z AND
10Z...A TAD LATER AT ART. THIS SHOULD BRING A PERIOD OF RAIN
SHOWERS...AND POSSIBLY A THUNDERSTORM TO ALL TAF SITES...WITH
MAINLY MVFR CONDITIONS IN CIGS/VSBY.
WINDS WILL SHIFT TO THE NW BEHIND THE SYSTEM LATE TONIGHT...WHICH
WILL LIKELY LOWER CIGS AND POSSIBLY VSBY IFR OR LOWER FOR A
PERIOD. CONDITIONS SHOULD GRADUALLY IMPROVE TO VFR DURING THE DAY
TUESDAY AS THE LOW LAYERS DRY OUT.
OUTLOOK...
TUESDAY NIGHT...VFR.
WEDNESDAY THROUGH SATURDAY...VFR/MVFR IN SHOWERS.
&&
.MARINE...
WINDS AND WAVES WILL REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA
DURING THIS PERIOD...ALTHOUGH MORE ACTIVE WEATHER CAN BE EXPECTED.
A WARM FRONT IS LIFTING ACROSS THE LOWER GREAT LAKES FROM THE OHIO VALLEY
TODAY. THIS WILL PRODUCE GENTLE TO OCCASIONALLY MODERATE EASTERLIES
ON LAKES ERIE AND ONTARIO...THEN AS THE WARM FRONT AND ITS SHOWERS
MOVE THROUGH THIS AFTERNOON AND EVENING WINDS WILL BECOME MORE
SOUTHEASTERLY. OVERNIGHT A SURFACE LOW WILL SHIFT EAST ACROSS LAKE ONTARIO
WITH WINDS SHIFTING TO SOUTHWEST BY TUESDAY MORNING. EXPECT LIGHT
WINDS AND NEGLIGIBLE WAVES THROUGH TUESDAY NIGHT.
&&
.CLIMATE...
THIS CHILLY SUNDAY MORNING SAW BUFFALO SET A NEW RECORD LOW
TEMPERATURE WITH THE 28 DEGREE READING BREAKING THE OLD RECORD OF
29. THIS IS THE FIRST TIME A RECORD LOW MINIMUM TEMPERATURE HAS
BEEN SET AT THE BUFFALO AIRPORT SINCE MARCH 6 2007.
ROCHESTER NEW YORK ALSO TIED A RECORD LOW THIS MORNING...THE 27
DEGREES TIED THE RECORD LOW VALUE. THIS IS THE FIRST TIME A RECORD
LOW MINIMUM WAS EITHER SET OR TIED AT ROCHESTER SINCE JULY 14 2009.
BUFFALO AND ROCHESTER WILL ALSO HAVE POTENTIAL FOR THEIR FIRST BELOW
NORMAL TEMPERATURE MONTH SINCE MARCH 2011. BOTH BUFFALO AND
ROCHESTER WITH HELP OF THE LAST 10 DAYS OF APRIL BELOW NORMAL MAY
JUST END FINISHING UP A FEW TENTHS OF A DEGREE BELOW NORMAL FOR
APRIL. FINAL STATISTICS WILL BE CALCULATED AFTER THE MONTH
FINISHES.
APRIL`S MONTHLY TEMPERATURE DEPARTURE IS A DRASTIC DIFFERENCE FROM
MARCH 2012 WHEN BOTH CITIES HAD A SIGNIFICANTLY ABOVE NORMAL
TEMPERATURE DEPARTURE. ONLY ONCE IN RECORDED HISTORY HAS THERE BEEN
A COOLER APRIL THAN MARCH AND THAT OCCURRED FOR BUFFALO BACK IN 1946.
THERE IS GOOD POTENTIAL FOR BOTH CITIES TO HAVE A COOLER APRIL
THAN MARCH IN 2012. THROUGH THE 28TH OF APRIL BUFFALO`S AVERAGE
APRIL TEMPERATURE IS 2.1 DEGREES COOLER THAN THE AVERAGE
TEMPERATURE RECORDED IN MARCH 2012. FOR ROCHESTER...WHICH HAS BEEN
SLIGHTLY WARMER THIS MONTH THROUGH THE SAME TIME SPAN...APRIL 2012
HAS BEEN 1.2 DEGREES COOLER THAN MARCH 2012.
BELOW ARE THE YEARS AND TOP FIVE LOWEST SPREADS BETWEEN APRIL
AVERAGE TEMPERATURE AND MARCH AVERAGE TEMPERATURE.
BUFFALO
YEAR APRIL AVG TEMPERATURE MINUS MARCH AVG TEMPERATURE
1946 -0.1
1898 2.3
1907 2.9
1903 3.0
1920 3.8
ROCHESTER
YEAR APRIL AVG TEMPERATURE MINUS MARCH AVG TEMPERATURE
1898 0.8
1946 1.2
1907 2.8
1903 3.0
1995 3.1
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...APFFEL/SMITH
SHORT TERM...WOOD
LONG TERM...WOOD
AVIATION...APFFEL
MARINE...APFFEL/SMITH/WOOD
CLIMATE...THOMAS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
827 PM EDT MON APR 30 2012
.SYNOPSIS...
A WARM FRONT WILL LIFT ACROSS NEW YORK FROM THE OHIO VALLEY THIS EVENING
WITH SOME SHOWERS AND AN ISOLATED THUNDERSTORM OR TWO. A COLD
FRONT WILL CROSS THE REGION LATE TONIGHT WITH ANOTHER ROUND OF
SHOWERS. CONDITIONS WILL THEN BECOME NOTABLY WARMER BUT UNSETTLED
ACROSS THE REGION TUESDAY THROUGH THE REMAINDER OF THE WEEK AS
TEMPERATURES WILL CLIMB WELL ABOVE NORMAL.
&&
.NEAR TERM /THROUGH TUESDAY/...
A BROAD AREA OF LOW PRESSURE LOOSELY CENTERED ACROSS THE OHIO
VALLEY WILL LIFT TO THE NORTHEAST ACROSS WESTERN NEW YORK TONIGHT.
RADAR TRENDS THROUGH THIS EVENING SHOW SHOWERS ACROSS CENTRAL NEW
YORK...WHICH WILL CONTINUE TO LIFT TO THE NORTHEAST. THESE ARE
ASSOCIATED WITH THE LEADING EDGE OF A LOW LEVEL JET ALONG THE WARM
FRONT. THIS BAND WAS NOT CAPTURED TERRIBLY WELL BY MODEL
GUIDANCE...BUT DO EXPECT IT TO WEAKEN AS IT CONTINUES TO MOVE INTO
DRIER AIR.
MEANWHILE...THE MAIN AREA OF PRECIPITATION STILL LIES UPSTREAM
ACROSS WESTERN OHIO...LAKE ERIE...AND SOUTHERN ONTARIO. A
CONSENSUS OF THE 18Z NAM/12Z RGEM/HRRR ARE QUITE CONSISTENT IN
BRINGING CONVECTIVE SHOWERS ACROSS WESTERN NEW YORK LATE
TONIGHT...ROUGHLY BETWEEN 04Z AND 10Z. RADAR TRENDS ARE IN GENERAL
SUPPORT OF THIS CONSENSUS...AND ARE WELL CAPTURED BY ALL THREE OF
THESE MODELS...THE HRRR IN PARTICULAR. GIVEN THESE SHOWERS ARE
ALREADY ONGOING...AND ARE QUITE SOLID ON RADAR UPSTREAM...HAVE
HIGH CONFIDENCE THAT THEY WILL REACH WESTERN NEW YORK AS MODEL
GUIDANCE SUGGESTS. ALSO...EXPECT SOME LIGHTNING WILL REACH WESTERN
NEW YORK WITH THIS AS WELL...THOUGH SURFACE BASED CONVECTION
SHOULD REMAIN TO THE SOUTH...WITH ELEVATED CONVECTION ACROSS
WESTERN NEW YORK SUPPORTING A MINIMAL (TO NIL) SEVERE WEATHER
THREAT. THIS SAID...EXPECT SHOWERS TO BRING A HALF INCH OR SO OF
RAIN TO SOUTHERN PORTIONS OF THE CWA...WITH LOCALLY HIGHER AMOUNTS
POSSIBLE IN THUNDERSTORMS.
OTHERWISE...TEMPERATURES WILL REMAIN MILD WITH WARMER AIR
SHIFTING ACROSS THE REGION WITHIN THE LOW PRESSURE SYSTEMS WARM
SECTOR. TEMPS WILL NOT FALL MUCH OVERNIGHT AND MAY IN FACT REMAIN
STEADY OR RISE. SOUTH I-90 WHERE WINDS HAVE GONE TO THE SE BEHIND
THE WARM FRONT...HEDGE ON THE WARM SIDE OF MOS GUIDANCE...WITH
STEADY TEMPERATURES IN THE 50S LIKELY OVERNIGHT.
TUESDAY...FRONT MAY STILL BE PRESSING EAST ACROSS CENTRAL AND
NORTHERN NEW YORK TUESDAY MORNING WITH CHANCES FOR SHOWERS. ALL
AREAS SHOULD BE DRY BY THE AFTERNOON WITH A WEAK HIGH PRESSURE
BUILDING IN BEHIND THE FRONT. MOST AREAS WILL TURN OUT PARTLY TO
MOSTLY SUNNY BY AFTERNOON. HIGHS LOOK TO REACH INTO THE LOW 60S
ESPECIALLY ACROSS WESTERN NEW YORK WHERE THE SUN WILL BREAK OUT
EARLIER THAN CENTRAL AND NORTHERN NY.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
WE WILL SEE A QUIET START TO THE PERIOD AS WESTERN AND CENTRAL NEW
YORK WILL BE FALLING UNDER THE INFLUENCE OF A BROAD UPPER LEVEL
RIDGE UPSTREAM. SUBSIDENCE OVER THE REGION SHOULD ALLOW FOR MOSTLY
CLEAR SKIES. THIS COMBINED WITH LIGHT WINDS SHOULD ALLOW FOR
TEMPERATURES TO DROP INTO THE UPPER 40S WITH MID 40S IN THE USUAL
COOL SPOTS OF THE SOUTHERN/TIER AND NORTH COUNTRY.
WEDNESDAY WILL FEATURE THE BEGINNING OF THE PRONOUNCED WARM-UP THAT
WILL BE AFFECTING THE REGION THROUGH THE REST OF THE WEEK. THE BROAD
UPPER LEVEL RIDGE WILL SETTLE OVER THE EASTERN UNITED STATES WHILE
RETURN FLOW AROUND A STRONG SURFACE HIGH ANCHORED OFF THE SOUTHEAST
U.S. COAST WILL PUMP INCREASINGLY WARM AND MOIST AIR NORTHWARDS
ACROSS THE OHIO VALLEY AND INTO THE GREAT LAKES REGION. THIS WILL
RESULT IN TEMPERATURES THAT WILL RISE WELL INTO THE 70S WEDNESDAY
AND THURSDAY WITH SOME AREAS POSSIBLY BREACHING 80 ON THURSDAY. IN
ADDITION TO THE WARMTH...IT WILL START TO FEEL MUGGY AS WELL AS
SURFACE DEW POINTS WILL ALSO RISE INTO 50S WEDNESDAY AND POSSIBLY LOW
60S THURSDAY AS THE RICH GULF MOISTURE SURGES NORTHWARDS.
WITH THE WARM AND MOIST AIR ADVECTING NORTH INTO THE REGION...WE
INTRODUCE THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS. THE GREATEST
POTENTIAL FOR CONVECTION ON WEDNESDAY WILL BE FOUND ACROSS
FAR WESTERN NEW YORK DURING LATE AFTERNOON AS THE LEADING EDGE OF A
THETA-E RIDGE SLIDES INTO THE NIAGARA FRONTIER. THE THREAT FOR
CONVECTION CONTINUES INTO WEDNESDAY NIGHT AS MODELS INDICATE ML CAPE
VALUES OF AROUND 400 J/KG WEST OF THE GENESEE VALLEY.
CONDITIONS THURSDAY SHOULD BE RIPE FOR SHOWERS AND THUNDERSTORMS AS
WE WILL REMAIN IN A VERY MOIST AIRMASS...HOWEVER WITH LIGHT FLOW AND
A LACK OF A CLEAR TRIGGER SUCH AS A SHORTWAVE...AM NOT EXPECTING
ORGANIZED OR SEVERE CONVECTION. HOWEVER MAY SEE WIDESPREAD
LAKE-BREEZE INDUCED SHOWERS/THUNDERSTORMS...PARTICULARLY INT HE
AFTERNOON/EVENING HOURS. THE FLY IN THE OINTMENT MAY BE WEAK
MID-LEVEL LAPSE RATES THAT MAY PUT A LID ON CONVECTION FROM BREAKING
OUT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
EXPECT MUCH OF THE SAME ON FRIDAY AS THE VERY WARM/MOIST AND
UNSTABLE AIRMASS LINGERS OVER THE REGION WITH HIGHS IN THE 70S AND
AT LEAST A CHANCE OF SHOWERS AND THUNDERSTORMS. THE FORECAST BECOMES
MURKIER BY THE WEEKEND WITH THE MODELS AT ODDS OVER THE
LOCATION/TIMING OF A COLD FRONT SWEEPING SOUTH OUT OF CANADA. THE
GFS PUSHES THE FRONT ACROSS THE FORECAST AREA SATURDAY...A PROSPECT
THAT WOULD RESULT IN A MUCH COOLER/DRIER WEEKEND THAN CURRENTLY
FORECAST. THE ECMWF...ON THE OTHER HAND...PUSHES A MUCH WEAKER
FRONT ACROSS THE REGION LATE ON SUNDAY. GIVEN THESE
DIFFERENCES...WILL OPT FOR A FORECAST THAT LEANS MORE TOWARDS THE
ECMWF/PERSISTENCE WITH HIGHS IN THE LOW 70S...LOWS IN THE 50S...AND
CHANCE POPS.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
FOR THIS EVENING...EXPECT SCATTERED SHOWERS ACROSS THE
REGION...WITH PRIMARILY VFR CONDITIONS OUTSIDE OF LOCALLY AND
BRIEF HEAVIER RAIN SHOWERS. THE 00Z BUFFALO SOUNDING CONFIRMS
MODEL FORECASTS...WITH WINDS AT 2000 FEET OF ABOUT 30 KTS OUT OF
THE SE. ALTHOUGH SPEED DIFFERENCE IS MODEST...THERE IS A DRASTIC
DIFFERENCE IN DIRECTION...SO WILL CARRY LLWS FOR A PERIOD AT ALL
TAF LOCATIONS UNTIL THESE WINDS ALOFT DECREASE LATER TONIGHT.
EXPECT THE MAIN AREA OF SHOWERS TO MOVE ACROSS BETWEEN 04Z AND
10Z...A TAD LATER AT ART. THIS SHOULD BRING A PERIOD OF RAIN
SHOWERS...AND POSSIBLY A THUNDERSTORM TO ALL TAF SITES...WITH
MAINLY MVFR CONDITIONS IN CIGS/VSBY.
WINDS WILL SHIFT TO THE NW BEHIND THE SYSTEM LATE TONIGHT...WHICH
WILL LIKELY LOWER CIGS AND POSSIBLY VSBY IFR OR LOWER FOR A
PERIOD. CONDITIONS SHOULD GRADUALLY IMPROVE TO VFR DURING THE DAY
TUESDAY AS THE LOW LAYERS DRY OUT.
OUTLOOK...
TUESDAY NIGHT...VFR.
WEDNESDAY THROUGH SATURDAY...VFR/MVFR IN SHOWERS.
&&
.MARINE...
WINDS AND WAVES WILL REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA
DURING THIS PERIOD...ALTHOUGH MORE ACTIVE WEATHER CAN BE EXPECTED.
A WARM FRONT IS LIFTING ACROSS THE LOWER GREAT LAKES FROM THE OHIO VALLEY
TODAY. THIS WILL PRODUCE GENTLE TO OCCASIONALLY MODERATE EASTERLIES
ON LAKES ERIE AND ONTARIO...THEN AS THE WARM FRONT AND ITS SHOWERS
MOVE THROUGH THIS AFTERNOON AND EVENING WINDS WILL BECOME MORE
SOUTHEASTERLY. OVERNIGHT A SURFACE LOW WILL SHIFT EAST ACROSS LAKE ONTARIO
WITH WINDS SHIFTING TO SOUTHWEST BY TUESDAY MORNING. EXPECT LIGHT
WINDS AND NEGLIGIBLE WAVES THROUGH TUESDAY NIGHT.
&&
.CLIMATE...
THIS CHILLY SUNDAY MORNING SAW BUFFALO SET A NEW RECORD LOW
TEMPERATURE WITH THE 28 DEGREE READING BREAKING THE OLD RECORD OF
29. THIS IS THE FIRST TIME A RECORD LOW MINIMUM TEMPERATURE HAS
BEEN SET AT THE BUFFALO AIRPORT SINCE MARCH 6 2007.
ROCHESTER NEW YORK ALSO TIED A RECORD LOW THIS MORNING...THE 27
DEGREES TIED THE RECORD LOW VALUE. THIS IS THE FIRST TIME A RECORD
LOW MINIMUM WAS EITHER SET OR TIED AT ROCHESTER SINCE JULY 14 2009.
BUFFALO AND ROCHESTER WILL ALSO HAVE POTENTIAL FOR THEIR FIRST BELOW
NORMAL TEMPERATURE MONTH SINCE MARCH 2011. BOTH BUFFALO AND
ROCHESTER WITH HELP OF THE LAST 10 DAYS OF APRIL BELOW NORMAL MAY
JUST END FINISHING UP A FEW TENTHS OF A DEGREE BELOW NORMAL FOR
APRIL. FINAL STATISTICS WILL BE CALCULATED AFTER THE MONTH
FINISHES.
APRIL`S MONTHLY TEMPERATURE DEPARTURE IS A DRASTIC DIFFERENCE FROM
MARCH 2012 WHEN BOTH CITIES HAD A SIGNIFICANTLY ABOVE NORMAL
TEMPERATURE DEPARTURE. ONLY ONCE IN RECORDED HISTORY HAS THERE BEEN
A COOLER APRIL THAN MARCH AND THAT OCCURRED FOR BUFFALO BACK IN 1946.
THERE IS GOOD POTENTIAL FOR BOTH CITIES TO HAVE A COOLER APRIL
THAN MARCH IN 2012. THROUGH THE 28TH OF APRIL BUFFALO`S AVERAGE
APRIL TEMPERATURE IS 2.1 DEGREES COOLER THAN THE AVERAGE
TEMPERATURE RECORDED IN MARCH 2012. FOR ROCHESTER...WHICH HAS BEEN
SLIGHTLY WARMER THIS MONTH THROUGH THE SAME TIME SPAN...APRIL 2012
HAS BEEN 1.2 DEGREES COOLER THAN MARCH 2012.
BELOW ARE THE YEARS AND TOP FIVE LOWEST SPREADS BETWEEN APRIL
AVERAGE TEMPERATURE AND MARCH AVERAGE TEMPERATURE.
BUFFALO
YEAR APRIL AVG TEMPERATURE MINUS MARCH AVG TEMPERATURE
1946 -0.1
1898 2.3
1907 2.9
1903 3.0
1920 3.8
ROCHESTER
YEAR APRIL AVG TEMPERATURE MINUS MARCH AVG TEMPERATURE
1898 0.8
1946 1.2
1907 2.8
1903 3.0
1995 3.1
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...APFFEL/SMITH
SHORT TERM...WOOD
LONG TERM...WOOD
AVIATION...APFFEL
MARINE...APFFEL/SMITH/WOOD
CLIMATE...THOMAS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
347 PM EDT SUN APR 29 2012
.SYNOPSIS...
A STALLED FRONT OVER SOUTH CAROLINA WILL RETURN NORTHWARD AS A WARM
FRONT OVER WESTERN PORTIONS OF THE STATE THIS AFTERNOON AND EVENING
AS HIGH PRESSURE STRENGTHENS AND PROGRESSES SOUTHWARD ALONG THE MID
ATLANTIC COAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM SUNDAY...
OVERVIEW:
AN H5 RIDGE CENTERED OVER THE WESTERN TN/OH VALLEYS AT 15Z WILL
PROGRESS EASTWARD TO THE SPINE OF THE APPALACHIANS BY 00-06Z
TONIGHT...RESULTING IN MODEST H5 HEIGHT RISES OVER THE MID-ATLANTIC
TODAY/TONIGHT. A SURFACE RIDGE AXIS EXTENDING SOUTH FROM THE
MID-ATLANTIC INTO THE CAROLINAS AT 15Z WILL WEAKEN IN WESTERN
PORTIONS OF THE STATE WHERE A WEAK TROUGH WILL DEVELOP. HOWEVER...
THE SURFACE RIDGE AXIS WILL STRENGTHEN TODAY/TONIGHT IN EASTERN
PORTIONS OF THE STATE IN ASSOC/W PRESSURE RISES ALONG THE MID-
ATLANTIC COAST...DUE TO HEIGHT RISES/SUBSIDENCE ALOFT IN ADVANCE OF
THE AFOREMENTIONED RIDGE. A SURFACE FRONT STALLED JUST S/SE OF THE
AREA OVER CENTRAL/SOUTHERN SOUTH CAROLINA AT 15Z IS PROGGED TO
ASSUME A NW-SE ORIENTATION TODAY/TONIGHT...LIFTING NORTHWARD INTO
PORTIONS OF THE WESTERN NC PIEDMONT/FOOTHILLS AND EXTENDING
SOUTHEAST IN VICINITY OF CAPE FEAR/WILMINGTON.
PRECIP CHANCES THIS AFT/EVE:
A WEAK UPPER LEVEL DISTURBANCE WAS NOTED IN WV IMAGERY/RUC DATA IN
SOUTHWEST VA AT 15Z. THE LATEST RUC SHOWS THIS FEATURE PROGRESSING
SOUTHEAST VIA NW FLOW ALOFT THROUGH THE NORTHEAST COASTAL PLAIN BY
18-21Z AND OFFSHORE THE NC OBX BY 21-00Z. GIVEN UNFAVORABLE
THERMODYNAMICS IN ADVANCE OF THIS FEATURE IN THE COASTAL PLAIN
(CLOUDY/COOL/STABLE) THROUGH 18-21Z...EXPECT DRY CONDITIONS TO
PREVAIL EAST OF HWY 1 THIS AFT/EVE. MODERATE INSTABILITY IS EXPECTED
THIS AFTERNOON IN FAR WESTERN PORTIONS OF THE STATE...THOUGH MLCAPE
VALUES SHOULD REMAIN ON THE MARGINAL SIDE (500-1000 J/KG) IN THE
WESTERN PIEDMONT...CLOSER TO THE DRIER SFC RIDGE AXIS TO THE EAST.
DESTABILIZATION IN THE WEST WILL BE AIDED BY INCREASING BOUNDARY
LAYER MOISTURE (ASSOC/W THE FRONT PROGRESSING NORTHWARD INTO WESTERN
NC) IN THE PRESENCE OF STEEP MID-LEVEL LAPSE RATES (7-8 C/KM) AND
CLEAR SKIES. HOWEVER...SUBSIDENCE IN THE WAKE OF THE AFOREMENTIONED
UPPER LEVEL DISTURBANCE ALONG WITH WEAK SYNOPTIC HEIGHT RISES IN
ADVANCE OF THE H5 RIDGE APPROACHING FROM THE WEST WILL BE
UNSUPPORTIVE OF PRECIP...AND LOW-LEVEL FORCING WILL BE CONFINED TO
BROAD WARM ADVECTION AND WEAK/SHALLOW LOW-LEVEL CONVERGENCE...WITH
THE RELATIVE BEST LOW-LEVEL FORCING CONFINED WEST OF I-77. IF ISOLD
CONVECTION DEVELOPS IN THE MOUNTAINS/FOOTHILLS AFTER 21Z...IT IS
CONCEIVABLE THAT IT COULD PROGRESS EAST/SE INTO PORTIONS OF THE NW
PIEDMONT BETWEEN 21-02Z THIS AFT/EVE VIA SPEEDY WESTERLY/WNW FLOW
ALOFT. THE LATEST 12Z WRF-NMM INDICATES THIS SCENARIO IS AT LEAST
POSSIBLE...AND WITH THAT IN MIND...WILL INTRODUCE A SLIGHT CHANCE OF
SHOWERS/STORMS TO THE FAR WESTERN PIEDMONT LATE THIS AFT/EVE.
IT IS INTERESTING THAT SUFFICIENT INSTABILITY AND 0-6 KM SHEAR MAY
BE PRESENT ON THE EASTERN PERIPHERY OF THE H5 RIDGE IN THE WESTERN
PIEDMONT TO SUPPORT A VERY LOW-END CONDITIONAL SEVERE THREAT LATER
THIS AFT/EVE...THOUGH A PROFOUND LACK OF FORCING AND THE PRESENCE OF
A DRY AIRMASS ALOFT (ASSOC/W AN EML EXTENDING EAST INTO THE AREA)
WILL MAKE IT DIFFICULT FOR ANY UPDRAFTS TO SURVIVE/PERSIST... SHOULD
ANY DEVELOP OR ADVECT INTO THE WESTERN PIEDMONT IN THE FIRST PLACE.
PRECIP CHANCES TONIGHT:
AS THE H5 RIDGE AXIS PROGRESSES EAST TO THE SPINE OF THE
APPALACHIANS TONIGHT...IT WILL BECOME INCREASINGLY DIFFICULT FOR ANY
UPSTREAM SHORTWAVES/MCVS (PROGRESSING EAST ATOP THE RIDGE) TO TRACK
INTO CENTRAL NC...WITH A MORE LIKELY TRACK FURTHER NORTH IN THE
MID-ATLANTIC. AS A RESULT...LITTLE OR NO UPPER SUPPORT WILL BE
PRESENT OVERNIGHT...THOUGH WEAK LOW-LEVEL WARM ADVECTION WILL BE
PRESENT. GIVEN THE CONTINUED PRESENCE OF AN ELEVATED MIXED LAYER
(ALBEIT MODIFIED)...EXPECT AT LEAST MARGINAL ELEVATED INSTABILITY TO
BE PRESENT OVERNIGHT. WITH THE ABOVE IN MIND...WILL CONTINUE TO
INDICATE A SLIGHT CHANCE OF SHOWERS OVERNIGHT IN ASSOC/W WARM
ADVECTION IN THE PRESENCE OF ELEVATED INSTABILITY. THUNDER CANNOT BE
RULED OUT...PRIMARILY IN THE WEST/NW PIEDMONT...THOUGH IT SEEMS
UNLIKELY IN THE ABSENCE OF ANY UPPER LEVEL SUPPORT.
LOWS TONIGHT:
AS THE SFC-H85 RIDGE STRENGTHENS OVER EASTERN NC/VA TONIGHT...
LOW-LEVEL FLOW WILL VEER TO THE EAST/SE AND ADVECT A MOIST MARITIME
AIRMASS INTO CENTRAL NC. WIDESPREAD LOW CLOUD COVER IS EXPECTED TO
ADVECT INTO OR RE-DEVELOP OVER THE AREA...THICKER/LOWER WEST OF I-95
IN CLOSER PROXIMITY TO BETTER LOW-LEVEL MOISTURE IN VICINITY OF THE
AFOREMENTIONED FRONTAL ZONE. EXPECT LOWS TO RANGE FROM THE MID/UPPER
50S EAST OF I-95 CENTRAL/NE COASTAL PLAIN TO THE UPPER 50S AND LOWER
60S ELSEWHERE...WARMEST SANDHILLS AND WEST/SW PIEDMONT. -VINCENT
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 345 PM SUNDAY...
OVERVIEW:
THE H5 RIDGE AXIS WILL PROGRESS EAST INTO THE MID-ATLANTIC AND
CAROLINAS ON MONDAY AS SHORTWAVE ENERGY TRACKS NORTHEAST THROUGH THE
GREAT LAKES INTO CANADA. THE RIDGE IS PROGGED TO WEAKEN MONDAY NIGHT
AS ADDITIONAL SHORTWAVE ENERGY PROGRESSES INTO THE MID-ATLANTIC FROM
THE SOUTHWEST. CENTRAL NC WILL BE ON THE NORTHERN PERIPHERY OF THE
RIDGE (CENTERED OVER THE DEEP SOUTH/SOUTHEAST STATES) ON MONDAY...IN
THE PRESENCE OF WESTERLY FLOW ALOFT. WESTERLY FLOW ALOFT WILL
STRENGTHEN MONDAY NIGHT AS THE RIDGE WEAKENS AND THE HEIGHT GRADIENT
TIGHTENS FROM THE NORTH. IN THE LOWER LEVELS...A LOW PRESSURE SYSTEM
TRACKING NORTHEAST THROUGH THE GREAT LAKES WILL PUSH HIGH PRESSURE
OFFSHORE THE MID-ATLANTIC/CAROLINA COAST ON MONDAY. THE RESULTING
SOUTHERLY RETURN FLOW WILL ALLOW THE NW-SE ORIENTED FRONTAL ZONE IN
IN PLACE OVER THE AREA TONIGHT TO MOVE NORTHEAST THROUGH THE ENTIRE
AREA AS A WARM FRONT DURING THE DAY MONDAY...WITH A WARM/MOIST
SOUTHERLY RETURN FLOW PERSISTING MONDAY NIGHT.
TEMPERATURES:
CHALLENGING FCST. EXPANSIVE LOW-LEVEL CLOUD COVER IS EXPECTED TO BE
IN PLACE SUNRISE MONDAY MORNING. FORECAST SOUNDINGS INDICATE THAT
THIS LOW STRATUS MAY TAKE AT LEAST SEVERAL HOURS TO LIFT AND SCATTER
OUT...PERHAPS NOT UNTIL 18-21Z IN SOME LOCATIONS. HIGH TEMPS WILL
DEPEND PRIMARILY ON THE TIMING OF CLOUD COVER EROSION. 1000-850 MB
THICKNESSES ARE PROGGED TO BE IN THE 1390-1405 METER RANGE ON
MONDAY... LOWEST NE COASTAL PLAIN AND HIGHEST W/SW PIEDMONT. AT THIS
TIME...WILL INDICATE HIGHS RANGING FROM THE MID 70S NE TO UPPER 70S/
LOWER 80S (76-81F) ELSEWHERE...WARMEST IN THE FAR SE PIEDMONT. GIVEN
WARM ADVECTION AND THE EXPECTED DEVELOPMENT OF LOW STRATUS AGAIN IN
MOST LOCATIONS MONDAY NIGHT...ANTICIPATE WARMER LOW TEMPERATURES...
IN THE LOWER 60S.
PRECIPITATION CHANCES:
DIFFICULT PRECIP FCST. DIURNAL DESTABILIZATION ON MONDAY WILL HIGHLY
DEPEND ON WHEN EXPANSIVE LOW-LEVEL CLOUD COVER LIFTS/SCATTERS OUT
AND WHERE THE BEST BOUNDARY LAYER MOISTURE WILL BE PRESENT IN THE
WAKE OF THE WARM FRONT PROGRESSING NE/NNE THROUGH THE AREA. GIVEN
THAT THE WARM FRONT WILL PROGRESS THROUGH THE WEST/SW PIEDMONT
FIRST...AREAS WEST OF HIGHWAY 1 WILL DESTABILIZE THE MOST ON MONDAY.
MODEL GUIDANCE IS INDICATING MLCAPE VALUES AS HIGH AS 1500-2000 J/KG
IN THE WESTERN PIEDMONT...OWING TO TEMPS IN THE UPPER 70S AND
DEWPOINTS IN THE LOWER 60S IN THE PRESENCE OF A MODIFIED EML WITH
MID-LEVEL LAPSE RATES ON THE ORDER OF 7-7.5 C/KM. FURTHER EAST WHERE
BOUNDARY LAYER MOISTURE WILL BE LOWER...MLCAPE VALUES WILL GENERALLY
RANGE FROM 500-1500 J/KG. W/REGARD TO FORCING...ALTHOUGH AN H5 RIDGE
AXIS WILL EXTEND NORTHWARD (FROM GA/FL) INTO THE CAROLINAS/
MID-ATLANTIC ON MONDAY...CENTRAL NC WILL REMAIN ON THE NORTHERN
PERIPHERY OF THE RIDGE IN WESTERLY FLOW ALOFT...AND SOME UPPER
FORCING IN THE FORM OF MINOR SHORTWAVES WILL BE POSSIBLE.
HOWEVER...THE TIMING AND EVOLUTION OF THESE FEATURES ARE DIFFICULT
TO ANTICIPATE AT THIS TIME. GIVEN A PATTERN OF SOUTHERLY/SE RETURN
FLOW...LOW-LEVEL FORCING WILL BE CONFINED TO UPSLOPE FLOW IN THE
FOOTHILLS/MOUNTAINS...AND TO THE SEABREEZE AND/OR DIFFERENTIAL
HEATING BOUNDARIES IN CENTRAL/EASTERN NC. GIVEN A FAIR AMOUNT OF
UNCERTAINTY W/REGARD TO WHETHER OR NOT SUFFICIENT FORCING WILL BE
PRESENT...WILL INDICATE A SLIGHT CHANCE OF SHOWERS/STORMS OVER THE
ENTIRE AREA MON AFT/EVE. FOR MONDAY NIGHT...GIVEN AN OVERALL LACK OF
FORCING AND A RELATIVELY LESS FAVORABLE (THAN TONIGHT) THERMODYNAMIC
ENVIRONMENT (I.E. VERY LITTLE IF ANY ELEVATED INSTABILITY)... HAVE
OPTED TO KEEP THE FCST DRY. -VINCENT
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 301 PM SUNDAY...
...SUMMER-LIKE TEMPERATURES AND HUMIDITIES EXPECTED TUESDAY THROUGH
THE END OF THE WEEK...
AS WE BEGIN A NEW MONTH ON TUESDAY... IT WILL BE LIKE FLIPPING A
SWITCH FROM MILD TO HOT. THE OVERALL MID-UPPER LEVEL FLOW PATTERN IS
A HIGH CONFIDENCE FORECAST FOR THE REGION AS MODELS ARE IN EXCELLENT
AGREEMENT IN THE DEVELOPMENT OF A MODERATELY STRONG UPPER LEVEL
RIDGE OVER THE SOUTHEASTERN UNITED STATES TUESDAY AND WEDNESDAY.
THE UPPER RIDGE IS FORECAST TO PERSIST WELL INTO THE END OF THE
WEEK. THE UPPER RIDGE AXIS IS FORECAST TO PEAK OVER NC/SC BY
WEDNESDAY INTO THURSDAY... THEN SHIFT WESTWARD IN TIME FRIDAY INTO
SUNDAY. THE BOTTOM LINE... EXPECT A DRAMATIC SHIFT FROM MILD AND
MOIST CONDITIONS FROM THE PAST FEW WEEKS... TO SUMMERTIME CONDITIONS
TUESDAY THROUGH THE REST OF THE WEEK.
THERE ARE INDICATIONS THAT THE HOT/HUMID WEATHER WILL LAST 5-6
DAYS... THEN IT SHOULD BE FOLLOWED BY A SIGNIFICANT COOL DOWN LATE
NEXT WEEKEND OR AROUND MAY 6-9. (IF THE MODELS ARE CORRECT IN THE
LONGER TERM FORECAST SHIFT IN THE UPPER RIDGE WESTWARD BACK TO THE
PLAINS - ALLOWING THE CARVING OUT OF A H5 TROUGH ALONG THE EASTERN
SEABOARD).
THEREFORE THIS WEEK... EXPECT HOT AND UNSEASONABLY HUMID
CONDITIONS... WITH ONLY A SLIGHT CHANCE OF AN AFTERNOON OR EVENING
THUNDERSTORM BEYOND TUESDAY.
SENSIBLE WEATHER WILL START WITH CONDITIONS BECOMING VERY WARM AND
HUMID TUESDAY AS THE LEAD WARM FRONT LIFTS NORTH OF OUR REGION.
THERE IS A POTENTIAL FOR SCATTERED AFTERNOON AND EVENING
THUNDERSTORMS AS MODELS INDICATE THE POTENTIAL FOR A VORTICITY
MAXIMUM TO RIDE A TOP THE BUILDING MID-UPPER LEVEL RIDGE OVER NC/VA
DURING MAXIMUM HEATING. FOR NOW... IT IS TOO EARLY TO LATCH ONTO
SUCH A FEATURE WITH ANY CONFIDENCE IN THE MODELS. HOWEVER... THIS
POTENTIAL WILL BE WATCHED. OTHERWISE... DIFFERENTIAL HEATING ALONG
THE EASTERN SLOPES OF THE MOUNTAINS SHOULD LEAD TO AT LEAST
SCATTERED THUNDERSTORMS TUESDAY AFTERNOON IN THE INCREASINGLY HUMID
BOUNDARY LAYER OVER NC/SW VA. SOME OF THESE MAY MOVE OFF OR DEVELOP
INTO THE PIEDMONT AS MODELS DO FAVOR A SURFACE TROUGH DEVELOPMENT IN
THE PIEDMONT DURING THE AFTERNOON. HIGHS WILL SOAR INTO THE MID TO
UPPER 80S. DEW POINTS SHOULD RISE TO BETWEEN 60-65... MAKING IT FEEL
LIKE JUNE OR EARLY JULY. WE WILL FORECAST 20-30 POP AND WAIT/SEE HOW
THE MODELS FORECAST ANY VORT MAX FOR TUESDAY TO AID IN CONVECTIVE
POTENTIAL.
AFTER THE SCATTERED CONVECTION POTENTIAL ENDS TUESDAY EVENING... WE
EXPECT THE MID-UPPER LEVEL RIDGING TO BE STRONG ENOUGH TO SUPPRESS
CONVECTIVE DEVELOPMENT IN THE ABSENCE OF ANY FOCUSING MECHANISMS
EVEN WITH DECENT LOW LEVEL MOISTURE AND HEAT. EXPECT GENERALLY WARM
DRY SUBSIDENCE IN THE MID LEVELS. WEDNESDAY THROUGH FRIDAY... MOSTLY
CLEAR MILD NIGHTS AND MOSTLY SUNNY HOT DAYS. DAILY TEMPERATURES
SHOULD AVERAGE A GOOD 10 DEGREES ABOVE NORMAL. NIGHTTIME LOWS A GOOD
10-15 DEGREES ABOVE NORMAL. LOWS SHOULD BE IN THE LOWER TO MID 60S
EACH DAY. HIGHS GENERALLY IN THE 85-90 RANGE.
SATURDAY AND SUNDAY... THE MID-UPPER HEIGHTS ARE FORECAST TO BEGIN
TO LOWER SOMEWHAT OVER THE SE WHICH SHOULD ALLOW DAILY TEMPERATURES
TO BACK OFF A FEW DEGREES. THE CHANCE OF CONVECTION SHOULD INCREASE
AT SOME POINT AS THE TROUGH DEVELOPS. HOWEVER... WE WILL KEEP ANY
MENTION OF SHOWERS OR THUNDERSTORMS ISOLATED... AND MAINLY LATE DAY
UNTIL A MORE DEFINITIVE TIMING OF AN ACTUAL COLD FRONT OR OTHER
FOCUS CAN BE PROJECTED. LOWS IN THE MID 60S. HIGHS IN THE LOWER TO
MID 80S.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 230 PM SUNDAY...
24-HR TAF PERIOD:
ASIDE FROM LINGERING MVFR CEILINGS AT THE FAY/RWI TAF SITES THIS
AFTERNOON...VFR CONDITIONS ARE EXPECTED THROUGH 00Z THIS EVENING.
TONIGHT...LOW-LEVEL MOISTURE WILL CONTINUE TO INCREASE IN VICINITY
OF A FRONTAL ZONE OVER THE FAR WESTERN PIEDMONT AND FOOTHILLS.
ADDITIONALLY...LOW-LEVEL FLOW WILL VEER TO THE EAST/SE...ALLOWING A
MOIST MARITIME AIRMASS TO PROGRESS WESTWARD INTO CENTRAL NC. AS A
RESULT...CONDITIONS ARE EXPECTED TO DETERIORATE AT ALL TAF SITES BY
03-07Z IN ASSOCIATION WITH THE EXPECTED DEVELOPMENT OF MVFR/IFR
CEILINGS. THE HIGHEST LIKELIHOOD OF IFR (AND PERHAPS LIFR) CEILINGS
WILL BE ALONG/WEST OF HIGHWAY 1...OR AT THE FAY/RDU/INT/GSO TAF
SITES. CONDITIONS ARE EXPECTED TO BE SLOW TO IMPROVE ON MONDAY...
WITH CEILINGS GRADUALLY LIFTING FROM IFR TO MVFR BY 18Z...AND FROM
MVFR TO VFR BY 21Z...THOUGH MVFR CEILINGS MAY PERSIST THROUGH SUNSET
IN SOME LOCATIONS.
LOOKING AHEAD:
MVFR/IFR STRATUS WILL BE POSSIBLE AGAIN TUESDAY MORNING...PRIMARILY
BETWEEN 06-12Z. ANY STRATUS THAT DEVELOPS IS EXPECTED TO RAPIDLY MIX
OUT AFTER SUNRISE TUE MORNING. ASIDE FROM A SMALL CHANCE FOR SHOWERS
AND STORMS EACH DAY THIS WEEK...VFR CONDITIONS ARE GENERALLY
EXPECTED TO PREDOMINATE. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...BADGETT
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
302 PM EDT SUN APR 29 2012
.SYNOPSIS...
A STALLED FRONT OVER SOUTH CAROLINA WILL RETURN NORTHWARD AS A WARM
FRONT OVER WESTERN PORTIONS OF THE STATE THIS AFTERNOON AND EVENING
AS HIGH PRESSURE STRENGTHENS AND PROGRESSES SOUTHWARD ALONG THE MID
ATLANTIC COAST.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 100 PM SUNDAY...
OVERVIEW:
AN H5 RIDGE CENTERED OVER THE WESTERN TN/OH VALLEYS AT 15Z WILL
PROGRESS EASTWARD TO THE SPINE OF THE APPALACHIANS BY 00-06Z
TONIGHT...RESULTING IN MODEST H5 HEIGHT RISES OVER THE MID-ATLANTIC
TODAY/TONIGHT. A SURFACE RIDGE AXIS EXTENDING SOUTH FROM THE
MID-ATLANTIC INTO THE CAROLINAS AT 15Z WILL WEAKEN IN WESTERN
PORTIONS OF THE STATE WHERE A WEAK TROUGH WILL DEVELOP. HOWEVER...
THE SURFACE RIDGE AXIS WILL STRENGTHEN TODAY/TONIGHT IN EASTERN
PORTIONS OF THE STATE IN ASSOC/W PRESSURE RISES ALONG THE MID-
ATLANTIC COAST...DUE TO HEIGHT RISES/SUBSIDENCE ALOFT IN ADVANCE OF
THE AFOREMENTIONED RIDGE. A SURFACE FRONT STALLED JUST S/SE OF THE
AREA OVER CENTRAL/SOUTHERN SOUTH CAROLINA AT 15Z IS PROGGED TO
ASSUME A NW-SE ORIENTATION TODAY/TONIGHT...LIFTING NORTHWARD INTO
PORTIONS OF THE WESTERN NC PIEDMONT/FOOTHILLS AND EXTENDING
SOUTHEAST IN VICINITY OF CAPE FEAR/WILMINGTON.
TEMPERATURES:
AS THE SFC-H85 RIDGE STRENGTHENS OVER EASTERN NC/VA TONIGHT...
LOW-LEVEL FLOW WILL VEER TO THE EAST/SE AND ADVECT A MOIST MARITIME
AIRMASS INTO CENTRAL NC. WIDESPREAD LOW CLOUD COVER IS EXPECTED TO
ADVECT INTO OR RE-DEVELOP OVER THE AREA...THICKER/LOWER WEST OF I-95
IN CLOSER PROXIMITY TO BETTER LOW-LEVEL MOISTURE IN VICINITY OF THE
AFOREMENTIONED FRONTAL ZONE. EXPECT LOWS TO RANGE FROM THE MID/UPPER
50S EAST OF I-95 CENTRAL/NE COASTAL PLAIN TO THE UPPER 50S AND LOWER
60S ELSEWHERE...WARMEST SANDHILLS AND WEST/SW PIEDMONT.
PRECIP CHANCES THIS AFT/EVE:
A WEAK UPPER LEVEL DISTURBANCE WAS NOTED IN WV IMAGERY/RUC DATA IN
SOUTHWEST VA AT 15Z. THE LATEST RUC SHOWS THIS FEATURE PROGRESSING
SOUTHEAST VIA NW FLOW ALOFT THROUGH THE NORTHEAST COASTAL PLAIN BY
18-21Z AND OFFSHORE THE NC OBX BY 21-00Z. GIVEN UNFAVORABLE
THERMODYNAMICS IN ADVANCE OF THIS FEATURE IN THE COASTAL PLAIN
(CLOUDY/COOL/STABLE) THROUGH 18-21Z...EXPECT DRY CONDITIONS TO
PREVAIL EAST OF HWY 1 THIS AFT/EVE. MODERATE INSTABILITY IS EXPECTED
THIS AFTERNOON IN FAR WESTERN PORTIONS OF THE STATE...THOUGH MLCAPE
VALUES SHOULD REMAIN ON THE MARGINAL SIDE (500-1000 J/KG) IN THE
WESTERN PIEDMONT...CLOSER TO THE DRIER SFC RIDGE AXIS TO THE EAST.
DESTABILIZATION IN THE WEST WILL BE AIDED BY INCREASING BOUNDARY
LAYER MOISTURE (ASSOC/W THE FRONT PROGRESSING NORTHWARD INTO WESTERN
NC) IN THE PRESENCE OF STEEP MID-LEVEL LAPSE RATES (7-8 C/KM) AND
CLEAR SKIES. HOWEVER...SUBSIDENCE IN THE WAKE OF THE AFOREMENTIONED
UPPER LEVEL DISTURBANCE ALONG WITH WEAK SYNOPTIC HEIGHT RISES IN
ADVANCE OF THE H5 RIDGE APPROACHING FROM THE WEST WILL BE
UNSUPPORTIVE OF PRECIP...AND LOW-LEVEL FORCING WILL BE CONFINED TO
BROAD WARM ADVECTION AND WEAK/SHALLOW LOW-LEVEL CONVERGENCE...WITH
THE RELATIVE BEST LOW-LEVEL FORCING CONFINED WEST OF I-77. IF ISOLD
CONVECTION DEVELOPS IN THE MOUNTAINS/FOOTHILLS AFTER 21Z...IT IS
CONCEIVABLE THAT IT COULD PROGRESS EAST/SE INTO PORTIONS OF THE NW
PIEDMONT BETWEEN 21-02Z THIS AFT/EVE VIA SPEEDY WESTERLY/WNW FLOW
ALOFT. THE LATEST 12Z WRF-NMM INDICATES THIS SCENARIO IS AT LEAST
POSSIBLE...AND WITH THAT IN MIND...WILL INTRODUCE A SLIGHT CHANCE OF
SHOWERS/STORMS TO THE FAR WESTERN PIEDMONT LATE THIS AFT/EVE.
IT IS INTERESTING THAT SUFFICIENT INSTABILITY AND 0-6 KM SHEAR MAY
BE PRESENT ON THE EASTERN PERIPHERY OF THE H5 RIDGE IN THE WESTERN
PIEDMONT TO SUPPORT A VERY LOW-END CONDITIONAL SEVERE THREAT LATER
THIS AFT/EVE...THOUGH A PROFOUND LACK OF FORCING AND THE PRESENCE OF
A DRY AIRMASS ALOFT (ASSOC/W AN EML EXTENDING EAST INTO THE AREA)
WILL MAKE IT DIFFICULT FOR ANY UPDRAFTS TO SURVIVE/PERSIST... SHOULD
ANY DEVELOP OR ADVECT INTO THE WESTERN PIEDMONT IN THE FIRST PLACE.
PRECIP CHANCES TONIGHT:
AS THE H5 RIDGE AXIS PROGRESSES EAST TO THE SPINE OF THE
APPALACHIANS TONIGHT...IT WILL BECOME INCREASINGLY DIFFICULT FOR ANY
UPSTREAM SHORTWAVES/MCVS (PROGRESSING EAST ATOP THE RIDGE) TO TRACK
INTO CENTRAL NC...WITH A MORE LIKELY TRACK FURTHER NORTH IN THE
MID-ATLANTIC. AS A RESULT...LITTLE OR NO UPPER SUPPORT WILL BE
PRESENT OVERNIGHT...THOUGH WEAK LOW-LEVEL WARM ADVECTION WILL BE
PRESENT. GIVEN THE CONTINUED PRESENCE OF AN ELEVATED MIXED LAYER
(ALBEIT MODIFIED)...EXPECT AT LEAST MARGINAL ELEVATED INSTABILITY TO
BE PRESENT OVERNIGHT. WITH THE ABOVE IN MIND...WILL CONTINUE TO
INDICATE A SLIGHT CHANCE OF SHOWERS OVERNIGHT IN ASSOC/W WARM
ADVECTION IN THE PRESENCE OF ELEVATED INSTABILITY. THUNDER CANNOT BE
RULED OUT...PRIMARILY IN THE WEST/NW PIEDMONT...THOUGH IT SEEMS
UNLIKELY IN THE ABSENCE OF ANY UPPER LEVEL SUPPORT. -VINCENT
MONDAY IS AGAIN A STRUGGLE WITH HOW QUICKLY LOW CLOUDS WILL SCOUR AS
HIGH PRESSURE SHIFTS OFF THE MID ATLANTIC COAST AND LOW LEVEL WINDS
BECOME SOUTH-SOUTHEASTERLY. WITH WESTERLY FLOW ALOFT....WARM
ADVECTION SHOWERS AND STORMS OVER THE HIGHER TERRAIN MAY BE ABLE
TO DRIFT EAST TOWARD THE WESTERN PIEDMONT...BUT COVERAGE SHOULD ONLY
BE ISOLATED. WE WILL CONTINUE TO LEAN TOWARD THE LOW SIDE OF
GUIDANCE FOR HIGHS...WITH LOW 70S NORTHEAST TO UPPER 70S SOUTHWEST.
LOWS MONDAY NIGHT AROUND 60.
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 230 AM SUNDAY...
MONDAY IS AGAIN A STRUGGLE WITH HOW QUICKLY LOW CLOUDS WILL SCOUR AS
HIGH PRESSURE SHIFTS OFF THE MID ATLANTIC COAST AND LOW LEVEL WINDS
BECOME SOUTH-SOUTHEASTERLY. WITH WESTERLY FLOW ALOFT....WARM
ADVECTION SHOWERS AND STORMS OVER THE HIGHER TERRAIN MAY BE ABLE
TO DRIFT EAST TOWARD THE WESTERN PIEDMONT...BUT COVERAGE SHOULD ONLY
BE ISOLATED. WE WILL CONTINUE TO LEAN TOWARD THE LOW SIDE OF
GUIDANCE FOR HIGHS...WITH LOW 70S NORTHEAST TO UPPER 70S SOUTHWEST.
LOWS MONDAY NIGHT AROUND 60.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 301 PM SUNDAY...
...SUMMER-LIKE TEMPERATURES AND HUMIDITIES EXPECTED TUESDAY THROUGH
THE END OF THE WEEK...
AS WE BEGIN A NEW MONTH ON TUESDAY... IT WILL BE LIKE FLIPPING A
SWITCH FROM MILD TO HOT. THE OVERALL MID-UPPER LEVEL FLOW PATTERN IS
A HIGH CONFIDENCE FORECAST FOR THE REGION AS MODELS ARE IN EXCELLENT
AGREEMENT IN THE DEVELOPMENT OF A MODERATELY STRONG UPPER LEVEL
RIDGE OVER THE SOUTHEASTERN UNITED STATES TUESDAY AND WEDNESDAY.
THE UPPER RIDGE IS FORECAST TO PERSIST WELL INTO THE END OF THE
WEEK. THE UPPER RIDGE AXIS IS FORECAST TO PEAK OVER NC/SC BY
WEDNESDAY INTO THURSDAY... THEN SHIFT WESTWARD IN TIME FRIDAY INTO
SUNDAY. THE BOTTOM LINE... EXPECT A DRAMATIC SHIFT FROM MILD AND
MOIST CONDITIONS FROM THE PAST FEW WEEKS... TO SUMMERTIME CONDITIONS
TUESDAY THROUGH THE REST OF THE WEEK.
THERE ARE INDICATIONS THAT THE HOT/HUMID WEATHER WILL LAST 5-6
DAYS... THEN IT SHOULD BE FOLLOWED BY A SIGNIFICANT COOL DOWN LATE
NEXT WEEKEND OR AROUND MAY 6-9. (IF THE MODELS ARE CORRECT IN THE
LONGER TERM FORECAST SHIFT IN THE UPPER RIDGE WESTWARD BACK TO THE
PLAINS - ALLOWING THE CARVING OUT OF A H5 TROUGH ALONG THE EASTERN
SEABOARD).
THEREFORE THIS WEEK... EXPECT HOT AND UNSEASONABLY HUMID
CONDITIONS... WITH ONLY A SLIGHT CHANCE OF AN AFTERNOON OR EVENING
THUNDERSTORM BEYOND TUESDAY.
SENSIBLE WEATHER WILL START WITH CONDITIONS BECOMING VERY WARM AND
HUMID TUESDAY AS THE LEAD WARM FRONT LIFTS NORTH OF OUR REGION.
THERE IS A POTENTIAL FOR SCATTERED AFTERNOON AND EVENING
THUNDERSTORMS AS MODELS INDICATE THE POTENTIAL FOR A VORTICITY
MAXIMUM TO RIDE A TOP THE BUILDING MID-UPPER LEVEL RIDGE OVER NC/VA
DURING MAXIMUM HEATING. FOR NOW... IT IS TOO EARLY TO LATCH ONTO
SUCH A FEATURE WITH ANY CONFIDENCE IN THE MODELS. HOWEVER... THIS
POTENTIAL WILL BE WATCHED. OTHERWISE... DIFFERENTIAL HEATING ALONG
THE EASTERN SLOPES OF THE MOUNTAINS SHOULD LEAD TO AT LEAST
SCATTERED THUNDERSTORMS TUESDAY AFTERNOON IN THE INCREASINGLY HUMID
BOUNDARY LAYER OVER NC/SW VA. SOME OF THESE MAY MOVE OFF OR DEVELOP
INTO THE PIEDMONT AS MODELS DO FAVOR A SURFACE TROUGH DEVELOPMENT IN
THE PIEDMONT DURING THE AFTERNOON. HIGHS WILL SOAR INTO THE MID TO
UPPER 80S. DEW POINTS SHOULD RISE TO BETWEEN 60-65... MAKING IT FEEL
LIKE JUNE OR EARLY JULY. WE WILL FORECAST 20-30 POP AND WAIT/SEE HOW
THE MODELS FORECAST ANY VORT MAX FOR TUESDAY TO AID IN CONVECTIVE
POTENTIAL.
AFTER THE SCATTERED CONVECTION POTENTIAL ENDS TUESDAY EVENING... WE
EXPECT THE MID-UPPER LEVEL RIDGING TO BE STRONG ENOUGH TO SUPPRESS
CONVECTIVE DEVELOPMENT IN THE ABSENCE OF ANY FOCUSING MECHANISMS
EVEN WITH DECENT LOW LEVEL MOISTURE AND HEAT. EXPECT GENERALLY WARM
DRY SUBSIDENCE IN THE MID LEVELS. WEDNESDAY THROUGH FRIDAY... MOSTLY
CLEAR MILD NIGHTS AND MOSTLY SUNNY HOT DAYS. DAILY TEMPERATURES
SHOULD AVERAGE A GOOD 10 DEGREES ABOVE NORMAL. NIGHTTIME LOWS A GOOD
10-15 DEGREES ABOVE NORMAL. LOWS SHOULD BE IN THE LOWER TO MID 60S
EACH DAY. HIGHS GENERALLY IN THE 85-90 RANGE.
SATURDAY AND SUNDAY... THE MID-UPPER HEIGHTS ARE FORECAST TO BEGIN
TO LOWER SOMEWHAT OVER THE SE WHICH SHOULD ALLOW DAILY TEMPERATURES
TO BACK OFF A FEW DEGREES. THE CHANCE OF CONVECTION SHOULD INCREASE
AT SOME POINT AS THE TROUGH DEVELOPS. HOWEVER... WE WILL KEEP ANY
MENTION OF SHOWERS OR THUNDERSTORMS ISOLATED... AND MAINLY LATE DAY
UNTIL A MORE DEFINITIVE TIMING OF AN ACTUAL COLD FRONT OR OTHER
FOCUS CAN BE PROJECTED. LOWS IN THE MID 60S. HIGHS IN THE LOWER TO
MID 80S.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 230 PM SUNDAY...
24-HR TAF PERIOD:
ASIDE FROM LINGERING MVFR CEILINGS AT THE FAY/RWI TAF SITES THIS
AFTERNOON...VFR CONDITIONS ARE EXPECTED THROUGH 00Z THIS EVENING.
TONIGHT...LOW-LEVEL MOISTURE WILL CONTINUE TO INCREASE IN VICINITY
OF A FRONTAL ZONE OVER THE FAR WESTERN PIEDMONT AND FOOTHILLS.
ADDITIONALLY...LOW-LEVEL FLOW WILL VEER TO THE EAST/SE...ALLOWING A
MOIST MARITIME AIRMASS TO PROGRESS WESTWARD INTO CENTRAL NC. AS A
RESULT...CONDITIONS ARE EXPECTED TO DETERIORATE AT ALL TAF SITES BY
03-07Z IN ASSOCIATION WITH THE EXPECTED DEVELOPMENT OF MVFR/IFR
CEILINGS. THE HIGHEST LIKELIHOOD OF IFR (AND PERHAPS LIFR) CEILINGS
WILL BE ALONG/WEST OF HIGHWAY 1...OR AT THE FAY/RDU/INT/GSO TAF
SITES. CONDITIONS ARE EXPECTED TO BE SLOW TO IMPROVE ON MONDAY...
WITH CEILINGS GRADUALLY LIFTING FROM IFR TO MVFR BY 18Z...AND FROM
MVFR TO VFR BY 21Z...THOUGH MVFR CEILINGS MAY PERSIST THROUGH SUNSET
IN SOME LOCATIONS.
LOOKING AHEAD:
MVFR/IFR STRATUS WILL BE POSSIBLE AGAIN TUESDAY MORNING...PRIMARILY
BETWEEN 06-12Z. ANY STRATUS THAT DEVELOPS IS EXPECTED TO RAPIDLY MIX
OUT AFTER SUNRISE TUE MORNING. ASIDE FROM A SMALL CHANCE FOR SHOWERS
AND STORMS EACH DAY THIS WEEK...VFR CONDITIONS ARE GENERALLY
EXPECTED TO PREDOMINATE. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...SMITH/99
LONG TERM...BADGETT
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
301 PM EDT SUN APR 29 2012
.SYNOPSIS...
A STALLED FRONT OVER SOUTH CAROLINA WILL RETURN NORTHWARD AS A WARM
FRONT OVER WESTERN PORTIONS OF THE STATE THIS AFTERNOON AND EVENING
AS HIGH PRESSURE STRENGTHENS AND PROGRESSES SOUTHWARD ALONG THE MID
ATLANTIC COAST.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 100 PM SUNDAY...
OVERVIEW:
AN H5 RIDGE CENTERED OVER THE WESTERN TN/OH VALLEYS AT 15Z WILL
PROGRESS EASTWARD TO THE SPINE OF THE APPALACHIANS BY 00-06Z
TONIGHT...RESULTING IN MODEST H5 HEIGHT RISES OVER THE MID-ATLANTIC
TODAY/TONIGHT. A SURFACE RIDGE AXIS EXTENDING SOUTH FROM THE
MID-ATLANTIC INTO THE CAROLINAS AT 15Z WILL WEAKEN IN WESTERN
PORTIONS OF THE STATE WHERE A WEAK TROUGH WILL DEVELOP. HOWEVER...
THE SURFACE RIDGE AXIS WILL STRENGTHEN TODAY/TONIGHT IN EASTERN
PORTIONS OF THE STATE IN ASSOC/W PRESSURE RISES ALONG THE MID-
ATLANTIC COAST...DUE TO HEIGHT RISES/SUBSIDENCE ALOFT IN ADVANCE OF
THE AFOREMENTIONED RIDGE. A SURFACE FRONT STALLED JUST S/SE OF THE
AREA OVER CENTRAL/SOUTHERN SOUTH CAROLINA AT 15Z IS PROGGED TO
ASSUME A NW-SE ORIENTATION TODAY/TONIGHT...LIFTING NORTHWARD INTO
PORTIONS OF THE WESTERN NC PIEDMONT/FOOTHILLS AND EXTENDING
SOUTHEAST IN VICINITY OF CAPE FEAR/WILMINGTON.
TEMPERATURES:
CHALLENGING FORECAST. LINGERING LOW STRATUS (CEILINGS 500-1500 FT
AGL) WAS PRESENT ALONG AND SOUTH OF HIGHWAY 64 THIS MORNING...ASIDE
FROM A FEW LOCATIONS IN THE FAR SOUTHWEST PIEDMONT RIGHT NEAR THE SC
BORDER. 1000-850 MB THICKNESSES ARE PROGGED TO RANGE FROM 1375-1385
METERS IN THE COASTAL PLAIN (CLOSER TO THE STRENGTHENING SFC RIDGE)
TO ~1400 METERS IN THE W/SW PIEDMONT (CLOSER TO THE AFOREMENTIONED
FRONT). HIGHS TODAY AT ANY GIVEN LOCATION WILL DEPEND PRIMARILY ON
TWO FACTORS...PROXIMITY TO THE COOLER AIRMASS TO THE EAST...THE
WARMER AIRMASS TO THE WEST...AND WHEN LINGERING LOW-LEVEL CLOUD
COVER WILL ERODE ALONG/SOUTH OF HWY 64. WITH THE ABOVE IN MIND...
WILL FCST HIGHS RANGING FROM THE UPPER 60S IN THE COASTAL PLAIN TO
THE MID 70S/LOWER 80S IN THE WEST/SW PIEDMONT AND PORTIONS OF THE
SANDHILLS...WARMEST WHERE CLOUD COVER ERODES QUICKEST. AS THE
SFC-H85 RIDGE STRENGTHENS OVER EASTERN NC/VA TONIGHT...LOW-LEVEL
FLOW WILL VEER TO THE EAST/SE AND ADVECT A MOIST MARITIME AIRMASS
INTO CENTRAL NC. WIDESPREAD LOW CLOUD COVER IS EXPECTED TO ADVECT
INTO OR RE-DEVELOP OVER THE AREA...THICKER/LOWER WEST OF I-95 IN
CLOSER PROXIMITY TO BETTER LOW-LEVEL MOISTURE IN VICINITY OF THE
AFOREMENTIONED FRONTAL ZONE. EXPECT LOWS TO RANGE FROM THE MID/UPPER
50S EAST OF I-95 CENTRAL/NE COASTAL PLAIN TO THE UPPER 50S AND LOWER
60S ELSEWHERE...WARMEST SANDHILLS AND WEST/SW PIEDMONT.
PRECIP CHANCES TODAY:
A WEAK UPPER LEVEL DISTURBANCE WAS NOTED IN WV IMAGERY/RUC DATA IN
SOUTHWEST VA AT 15Z. THE LATEST RUC SHOWS THIS FEATURE PROGRESSING
SOUTHEAST VIA NW FLOW ALOFT THROUGH THE NORTHEAST COASTAL PLAIN BY
18-21Z AND OFFSHORE THE NC OBX BY 21-00Z. GIVEN UNFAVORABLE
THERMODYNAMICS IN ADVANCE OF THIS FEATURE IN THE COASTAL PLAIN
(CLOUDY/COOL/STABLE) THROUGH 18-21Z...EXPECT DRY CONDITIONS TO
PREVAIL EAST OF HWY 1 THIS AFT/EVE. MODERATE INSTABILITY IS EXPECTED
THIS AFTERNOON IN FAR WESTERN PORTIONS OF THE STATE...THOUGH MLCAPE
VALUES SHOULD REMAIN ON THE MARGINAL SIDE (500-1000 J/KG) IN THE
WESTERN PIEDMONT...CLOSER TO THE DRIER SFC RIDGE AXIS TO THE EAST.
DESTABILIZATION IN THE WEST WILL BE AIDED BY INCREASING BOUNDARY
LAYER MOISTURE (ASSOC/W THE FRONT PROGRESSING NORTHWARD INTO WESTERN
NC) IN THE PRESENCE OF STEEP MID-LEVEL LAPSE RATES (7-8 C/KM) AND
CLEAR SKIES. HOWEVER...SUBSIDENCE IN THE WAKE OF THE AFOREMENTIONED
UPPER LEVEL DISTURBANCE ALONG WITH WEAK SYNOPTIC HEIGHT RISES IN
ADVANCE OF THE H5 RIDGE APPROACHING FROM THE WEST WILL BE
UNSUPPORTIVE OF PRECIP...AND LOW-LEVEL FORCING WILL BE CONFINED TO
BROAD WARM ADVECTION AND WEAK/SHALLOW LOW-LEVEL CONVERGENCE...WITH
THE RELATIVE BEST LOW-LEVEL FORCING CONFINED WEST OF I-77. IF ISOLD
CONVECTION DEVELOPS IN THE MOUNTAINS/FOOTHILLS AFTER 21Z...IT IS
CONCEIVABLE THAT IT COULD PROGRESS EAST/SE INTO PORTIONS OF THE NW
PIEDMONT BETWEEN 21-02Z THIS AFT/EVE VIA SPEEDY WESTERLY/WNW FLOW
ALOFT. THE LATEST 12Z WRF-NMM INDICATES THIS SCENARIO IS AT LEAST
POSSIBLE...AND WITH THAT IN MIND...WILL INTRODUCE A SLIGHT CHANCE OF
SHOWERS/STORMS TO THE FAR WESTERN PIEDMONT LATE THIS AFT/EVE.
IT IS INTERESTING THAT SUFFICIENT INSTABILITY AND 0-6 KM SHEAR MAY
BE PRESENT ON THE EASTERN PERIPHERY OF THE H5 RIDGE IN THE WESTERN
PIEDMONT TO SUPPORT A VERY LOW-END CONDITIONAL SEVERE THREAT LATER
THIS AFT/EVE...THOUGH A PROFOUND LACK OF FORCING AND THE PRESENCE OF
A DRY AIRMASS ALOFT (ASSOC/W AN EML EXTENDING EAST INTO THE AREA)
WILL MAKE IT DIFFICULT FOR ANY UPDRAFTS TO SURVIVE/PERSIST... SHOULD
ANY DEVELOP OR ADVECT INTO THE WESTERN PIEDMONT IN THE FIRST PLACE.
PRECIP CHANCES TONIGHT:
AS THE H5 RIDGE AXIS PROGRESSES EAST TO THE SPINE OF THE
APPALACHIANS TONIGHT...IT WILL BECOME INCREASINGLY DIFFICULT FOR ANY
UPSTREAM SHORTWAVES/MCVS (PROGRESSING EAST ATOP THE RIDGE) TO TRACK
INTO CENTRAL NC...WITH A MORE LIKELY TRACK FURTHER NORTH IN THE
MID-ATLANTIC. AS A RESULT...LITTLE OR NO UPPER SUPPORT WILL BE
PRESENT OVERNIGHT...THOUGH WEAK LOW-LEVEL WARM ADVECTION WILL BE
PRESENT. GIVEN THE CONTINUED PRESENCE OF AN ELEVATED MIXED LAYER
(ALBEIT MODIFIED)...EXPECT AT LEAST MARGINAL ELEVATED INSTABILITY TO
BE PRESENT OVERNIGHT. WITH THE ABOVE IN MIND...WILL CONTINUE TO
INDICATE A SLIGHT CHANCE OF SHOWERS OVERNIGHT IN ASSOC/W WARM
ADVECTION IN THE PRESENCE OF ELEVATED INSTABILITY. THUNDER CANNOT BE
RULED OUT...PRIMARILY IN THE WEST/NW PIEDMONT...THOUGH IT SEEMS
UNLIKELY IN THE ABSENCE OF ANY UPPER LEVEL SUPPORT. -VINCENT
MONDAY IS AGAIN A STRUGGLE WITH HOW QUICKLY LOW CLOUDS WILL SCOUR AS
HIGH PRESSURE SHIFTS OFF THE MID ATLANTIC COAST AND LOW LEVEL WINDS
BECOME SOUTH-SOUTHEASTERLY. WITH WESTERLY FLOW ALOFT....WARM
ADVECTION SHOWERS AND STORMS OVER THE HIGHER TERRAIN MAY BE ABLE
TO DRIFT EAST TOWARD THE WESTERN PIEDMONT...BUT COVERAGE SHOULD ONLY
BE ISOLATED. WE WILL CONTINUE TO LEAN TOWARD THE LOW SIDE OF
GUIDANCE FOR HIGHS...WITH LOW 70S NORTHEAST TO UPPER 70S SOUTHWEST.
LOWS MONDAY NIGHT AROUND 60.
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 230 AM SUNDAY...
MONDAY IS AGAIN A STRUGGLE WITH HOW QUICKLY LOW CLOUDS WILL SCOUR AS
HIGH PRESSURE SHIFTS OFF THE MID ATLANTIC COAST AND LOW LEVEL WINDS
BECOME SOUTH-SOUTHEASTERLY. WITH WESTERLY FLOW ALOFT....WARM
ADVECTION SHOWERS AND STORMS OVER THE HIGHER TERRAIN MAY BE ABLE
TO DRIFT EAST TOWARD THE WESTERN PIEDMONT...BUT COVERAGE SHOULD ONLY
BE ISOLATED. WE WILL CONTINUE TO LEAN TOWARD THE LOW SIDE OF
GUIDANCE FOR HIGHS...WITH LOW 70S NORTHEAST TO UPPER 70S SOUTHWEST.
LOWS MONDAY NIGHT AROUND 60.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 301 PM SUNDAY...
...SUMMER-LIKE TEMPERATURES AND HUMIDITIES EXPECTED TUESDAY THROUGH
THE END OF THE WEEK...
AS WE BEGIN A NEW MONTH ON TUESDAY... IT WILL BE LIKE FLIPPING A
SWITCH FROM MILD TO HOT. THE OVERALL MID-UPPER LEVEL FLOW PATTERN IS
A HIGH CONFIDENCE FORECAST FOR THE REGION AS MODELS ARE IN EXCELLENT
AGREEMENT IN THE DEVELOPMENT OF A MODERATELY STRONG UPPER LEVEL
RIDGE OVER THE SOUTHEASTERN UNITED STATES TUESDAY AND WEDNESDAY.
THE UPPER RIDGE IS FORECAST TO PERSIST WELL INTO THE END OF THE
WEEK. THE UPPER RIDGE AXIS IS FORECAST TO PEAK OVER NC/SC BY
WEDNESDAY INTO THURSDAY... THEN SHIFT WESTWARD IN TIME FRIDAY INTO
SUNDAY. THE BOTTOM LINE... EXPECT A DRAMATIC SHIFT FROM MILD AND
MOIST CONDITIONS FROM THE PAST FEW WEEKS... TO SUMMERTIME CONDITIONS
TUESDAY THROUGH THE REST OF THE WEEK.
THERE ARE INDICATIONS THAT THE HOT/HUMID WEATHER WILL LAST 5-6
DAYS... THEN IT SHOULD BE FOLLOWED BY A SIGNIFICANT COOL DOWN LATE
NEXT WEEKEND OR AROUND MAY 6-9. (IF THE MODELS ARE CORRECT IN THE
LONGER TERM FORECAST SHIFT IN THE UPPER RIDGE WESTWARD BACK TO THE
PLAINS - ALLOWING THE CARVING OUT OF A H5 TROUGH ALONG THE EASTERN
SEABOARD).
THEREFORE THIS WEEK... EXPECT HOT AND UNSEASONABLY HUMID
CONDITIONS... WITH ONLY A SLIGHT CHANCE OF AN AFTERNOON OR EVENING
THUNDERSTORM BEYOND TUESDAY.
SENSIBLE WEATHER WILL START WITH CONDITIONS BECOMING VERY WARM AND
HUMID TUESDAY AS THE LEAD WARM FRONT LIFTS NORTH OF OUR REGION.
THERE IS A POTENTIAL FOR SCATTERED AFTERNOON AND EVENING
THUNDERSTORMS AS MODELS INDICATE THE POTENTIAL FOR A VORTICITY
MAXIMUM TO RIDE A TOP THE BUILDING MID-UPPER LEVEL RIDGE OVER NC/VA
DURING MAXIMUM HEATING. FOR NOW... IT IS TOO EARLY TO LATCH ONTO
SUCH A FEATURE WITH ANY CONFIDENCE IN THE MODELS. HOWEVER... THIS
POTENTIAL WILL BE WATCHED. OTHERWISE... DIFFERENTIAL HEATING ALONG
THE EASTERN SLOPES OF THE MOUNTAINS SHOULD LEAD TO AT LEAST
SCATTERED THUNDERSTORMS TUESDAY AFTERNOON IN THE INCREASINGLY HUMID
BOUNDARY LAYER OVER NC/SW VA. SOME OF THESE MAY MOVE OFF OR DEVELOP
INTO THE PIEDMONT AS MODELS DO FAVOR A SURFACE TROUGH DEVELOPMENT IN
THE PIEDMONT DURING THE AFTERNOON. HIGHS WILL SOAR INTO THE MID TO
UPPER 80S. DEW POINTS SHOULD RISE TO BETWEEN 60-65... MAKING IT FEEL
LIKE JUNE OR EARLY JULY. WE WILL FORECAST 20-30 POP AND WAIT/SEE HOW
THE MODELS FORECAST ANY VORT MAX FOR TUESDAY TO AID IN CONVECTIVE
POTENTIAL.
AFTER THE SCATTERED CONVECTION POTENTIAL ENDS TUESDAY EVENING... WE
EXPECT THE MID-UPPER LEVEL RIDGING TO BE STRONG ENOUGH TO SUPPRESS
CONVECTIVE DEVELOPMENT IN THE ABSENCE OF ANY FOCUSING MECHANISMS
EVEN WITH DECENT LOW LEVEL MOISTURE AND HEAT. EXPECT GENERALLY WARM
DRY SUBSIDENCE IN THE MID LEVELS. WEDNESDAY THROUGH FRIDAY... MOSTLY
CLEAR MILD NIGHTS AND MOSTLY SUNNY HOT DAYS. DAILY TEMPERATURES
SHOULD AVERAGE A GOOD 10 DEGREES ABOVE NORMAL. NIGHTTIME LOWS A GOOD
10-15 DEGREES ABOVE NORMAL. LOWS SHOULD BE IN THE LOWER TO MID 60S
EACH DAY. HIGHS GENERALLY IN THE 85-90 RANGE.
SATURDAY AND SUNDAY... THE MID-UPPER HEIGHTS ARE FORECAST TO BEGIN
TO LOWER SOMEWHAT OVER THE SE WHICH SHOULD ALLOW DAILY TEMPERATURES
TO BACK OFF A FEW DEGREES. THE CHANCE OF CONVECTION SHOULD INCREASE
AT SOME POINT AS THE TROUGH DEVELOPS. HOWEVER... WE WILL KEEP ANY
MENTION OF SHOWERS OR THUNDERSTORMS ISOLATED... AND MAINLY LATE DAY
UNTIL A MORE DEFINITIVE TIMING OF AN ACTUAL COLD FRONT OR OTHER
FOCUS CAN BE PROJECTED. LOWS IN THE MID 60S. HIGHS IN THE LOWER TO
MID 80S.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 700 AM SUNDAY...
MVFR CEILINGS ARE PREDOMINATE ACROSS ALL OF CENTRAL NC THIS MORNING
AS LOW LEVEL MOISTURE REMAIN LOCKED IN PLACE NORTH OF STATIONARY
FRONT OVER SC. THE EXCEPTION IS OVER THE TRIAD WHERE DRIER AIR HAS
CAUSED THE LOW CLOUDS TO BREAK. MODELS INDICATE THE SHALLOW LAYER OF
LOW LEVEL MOISTURE WILL CONTINUE TO ERODE WITH SOUTH-SOUTHWESTERLY
LOW TO MID LEVEL FLOW TODAY. HOWEVER...MODELS MAY BE ERODING
STRATUS FROM THE SOUTH AND WEST TOO QUICKLY...AS THEY OFTEN DO....SO
MVFR CEILINGS MAY PERSIST WELL INTO THE AFTERNOON FROM KRDU TO
KRWI. WINDS WILL GENERALLY BE LIGHT AND VARIABLE FOR A GOOD PORTION
OF THE DAY BUT WILL BECOME EAST-NORTHEASTERLY AGAIN THIS EVENING AS
HIGH PRESSURE OVER THE GREAT LAKES PUSHES ANOTHER COLD FRONT INTO
THE AREA FROM THE NORTH. THIS COOL STABLE FLOW WILL BRING STRATUS
BACK ACROSS THE AREA ONCE AGAIN TONIGHT AND MONDAY
MORNING...POTENTIALLY WITH PATCHY LIGHT RAIN AT TIMES. -SMITH
OUTLOOK...
MVFR CEILINGS MAY PERSIST INTO THE DAY ON MONDAY...THOUGH AN OVERALL
DRYING TREND IS EXPECTED THROUGH MID WEEK AS AN UPPER LEVEL RIDGE
SETTLES OVER THE REGION. AFTERNOON SHOWERS/STORMS MAY BE POSSIBLE BY
WEDNESDAY BUT VFR CONDITIONS ARE EXPECTED TO PREVAIL FOR MUCH OF THE
WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...SMITH/99
LONG TERM...BADGETT
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
112 PM EDT SUN APR 29 2012
.SYNOPSIS...
A STALLED FRONT OVER SOUTH CAROLINA WILL RETURN NORTHWARD AS A WARM
FRONT OVER WESTERN PORTIONS OF THE STATE THIS AFTERNOON AND EVENING
AS HIGH PRESSURE STRENGTHENS AND PROGRESSES SOUTHWARD ALONG THE MID
ATLANTIC COAST.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 100 PM SUNDAY...
OVERVIEW:
AN H5 RIDGE CENTERED OVER THE WESTERN TN/OH VALLEYS AT 15Z WILL
PROGRESS EASTWARD TO THE SPINE OF THE APPALACHIANS BY 00-06Z
TONIGHT...RESULTING IN MODEST H5 HEIGHT RISES OVER THE MID-ATLANTIC
TODAY/TONIGHT. A SURFACE RIDGE AXIS EXTENDING SOUTH FROM THE
MID-ATLANTIC INTO THE CAROLINAS AT 15Z WILL WEAKEN IN WESTERN
PORTIONS OF THE STATE WHERE A WEAK TROUGH WILL DEVELOP. HOWEVER...
THE SURFACE RIDGE AXIS WILL STRENGTHEN TODAY/TONIGHT IN EASTERN
PORTIONS OF THE STATE IN ASSOC/W PRESSURE RISES ALONG THE MID-
ATLANTIC COAST...DUE TO HEIGHT RISES/SUBSIDENCE ALOFT IN ADVANCE OF
THE AFOREMENTIONED RIDGE. A SURFACE FRONT STALLED JUST S/SE OF THE
AREA OVER CENTRAL/SOUTHERN SOUTH CAROLINA AT 15Z IS PROGGED TO
ASSUME A NW-SE ORIENTATION TODAY/TONIGHT...LIFTING NORTHWARD INTO
PORTIONS OF THE WESTERN NC PIEDMONT/FOOTHILLS AND EXTENDING
SOUTHEAST IN VICINITY OF CAPE FEAR/WILMINGTON.
TEMPERATURES:
CHALLENGING FORECAST. LINGERING LOW STRATUS (CEILINGS 500-1500 FT
AGL) WAS PRESENT ALONG AND SOUTH OF HIGHWAY 64 THIS MORNING...ASIDE
FROM A FEW LOCATIONS IN THE FAR SOUTHWEST PIEDMONT RIGHT NEAR THE SC
BORDER. 1000-850 MB THICKNESSES ARE PROGGED TO RANGE FROM 1375-1385
METERS IN THE COASTAL PLAIN (CLOSER TO THE STRENGTHENING SFC RIDGE)
TO ~1400 METERS IN THE W/SW PIEDMONT (CLOSER TO THE AFOREMENTIONED
FRONT). HIGHS TODAY AT ANY GIVEN LOCATION WILL DEPEND PRIMARILY ON
TWO FACTORS...PROXIMITY TO THE COOLER AIRMASS TO THE EAST...THE
WARMER AIRMASS TO THE WEST...AND WHEN LINGERING LOW-LEVEL CLOUD
COVER WILL ERODE ALONG/SOUTH OF HWY 64. WITH THE ABOVE IN MIND...
WILL FCST HIGHS RANGING FROM THE UPPER 60S IN THE COASTAL PLAIN TO
THE MID 70S/LOWER 80S IN THE WEST/SW PIEDMONT AND PORTIONS OF THE
SANDHILLS...WARMEST WHERE CLOUD COVER ERODES QUICKEST. AS THE
SFC-H85 RIDGE STRENGTHENS OVER EASTERN NC/VA TONIGHT...LOW-LEVEL
FLOW WILL VEER TO THE EAST/SE AND ADVECT A MOIST MARITIME AIRMASS
INTO CENTRAL NC. WIDESPREAD LOW CLOUD COVER IS EXPECTED TO ADVECT
INTO OR RE-DEVELOP OVER THE AREA...THICKER/LOWER WEST OF I-95 IN
CLOSER PROXIMITY TO BETTER LOW-LEVEL MOISTURE IN VICINITY OF THE
AFOREMENTIONED FRONTAL ZONE. EXPECT LOWS TO RANGE FROM THE MID/UPPER
50S EAST OF I-95 CENTRAL/NE COASTAL PLAIN TO THE UPPER 50S AND LOWER
60S ELSEWHERE...WARMEST SANDHILLS AND WEST/SW PIEDMONT.
PRECIP CHANCES TODAY:
A WEAK UPPER LEVEL DISTURBANCE WAS NOTED IN WV IMAGERY/RUC DATA IN
SOUTHWEST VA AT 15Z. THE LATEST RUC SHOWS THIS FEATURE PROGRESSING
SOUTHEAST VIA NW FLOW ALOFT THROUGH THE NORTHEAST COASTAL PLAIN BY
18-21Z AND OFFSHORE THE NC OBX BY 21-00Z. GIVEN UNFAVORABLE
THERMODYNAMICS IN ADVANCE OF THIS FEATURE IN THE COASTAL PLAIN
(CLOUDY/COOL/STABLE) THROUGH 18-21Z...EXPECT DRY CONDITIONS TO
PREVAIL EAST OF HWY 1 THIS AFT/EVE. MODERATE INSTABILITY IS EXPECTED
THIS AFTERNOON IN FAR WESTERN PORTIONS OF THE STATE...THOUGH MLCAPE
VALUES SHOULD REMAIN ON THE MARGINAL SIDE (500-1000 J/KG) IN THE
WESTERN PIEDMONT...CLOSER TO THE DRIER SFC RIDGE AXIS TO THE EAST.
DESTABILIZATION IN THE WEST WILL BE AIDED BY INCREASING BOUNDARY
LAYER MOISTURE (ASSOC/W THE FRONT PROGRESSING NORTHWARD INTO WESTERN
NC) IN THE PRESENCE OF STEEP MID-LEVEL LAPSE RATES (7-8 C/KM) AND
CLEAR SKIES. HOWEVER...SUBSIDENCE IN THE WAKE OF THE AFOREMENTIONED
UPPER LEVEL DISTURBANCE ALONG WITH WEAK SYNOPTIC HEIGHT RISES IN
ADVANCE OF THE H5 RIDGE APPROACHING FROM THE WEST WILL BE
UNSUPPORTIVE OF PRECIP...AND LOW-LEVEL FORCING WILL BE CONFINED TO
BROAD WARM ADVECTION AND WEAK/SHALLOW LOW-LEVEL CONVERGENCE...WITH
THE RELATIVE BEST LOW-LEVEL FORCING CONFINED WEST OF I-77. IF ISOLD
CONVECTION DEVELOPS IN THE MOUNTAINS/FOOTHILLS AFTER 21Z...IT IS
CONCEIVABLE THAT IT COULD PROGRESS EAST/SE INTO PORTIONS OF THE NW
PIEDMONT BETWEEN 21-02Z THIS AFT/EVE VIA SPEEDY WESTERLY/WNW FLOW
ALOFT. THE LATEST 12Z WRF-NMM INDICATES THIS SCENARIO IS AT LEAST
POSSIBLE...AND WITH THAT IN MIND...WILL INTRODUCE A SLIGHT CHANCE OF
SHOWERS/STORMS TO THE FAR WESTERN PIEDMONT LATE THIS AFT/EVE.
IT IS INTERESTING THAT SUFFICIENT INSTABILITY AND 0-6 KM SHEAR MAY
BE PRESENT ON THE EASTERN PERIPHERY OF THE H5 RIDGE IN THE WESTERN
PIEDMONT TO SUPPORT A VERY LOW-END CONDITIONAL SEVERE THREAT LATER
THIS AFT/EVE...THOUGH A PROFOUND LACK OF FORCING AND THE PRESENCE OF
A DRY AIRMASS ALOFT (ASSOC/W AN EML EXTENDING EAST INTO THE AREA)
WILL MAKE IT DIFFICULT FOR ANY UPDRAFTS TO SURVIVE/PERSIST... SHOULD
ANY DEVELOP OR ADVECT INTO THE WESTERN PIEDMONT IN THE FIRST PLACE.
PRECIP CHANCES TONIGHT:
AS THE H5 RIDGE AXIS PROGRESSES EAST TO THE SPINE OF THE
APPALACHIANS TONIGHT...IT WILL BECOME INCREASINGLY DIFFICULT FOR ANY
UPSTREAM SHORTWAVES/MCVS (PROGRESSING EAST ATOP THE RIDGE) TO TRACK
INTO CENTRAL NC...WITH A MORE LIKELY TRACK FURTHER NORTH IN THE
MID-ATLANTIC. AS A RESULT...LITTLE OR NO UPPER SUPPORT WILL BE
PRESENT OVERNIGHT...THOUGH WEAK LOW-LEVEL WARM ADVECTION WILL BE
PRESENT. GIVEN THE CONTINUED PRESENCE OF AN ELEVATED MIXED LAYER
(ALBEIT MODIFIED)...EXPECT AT LEAST MARGINAL ELEVATED INSTABILITY TO
BE PRESENT OVERNIGHT. WITH THE ABOVE IN MIND...WILL CONTINUE TO
INDICATE A SLIGHT CHANCE OF SHOWERS OVERNIGHT IN ASSOC/W WARM
ADVECTION IN THE PRESENCE OF ELEVATED INSTABILITY. THUNDER CANNOT BE
RULED OUT...PRIMARILY IN THE WEST/NW PIEDMONT...THOUGH IT SEEMS
UNLIKELY IN THE ABSENCE OF ANY UPPER LEVEL SUPPORT. -VINCENT
MONDAY IS AGAIN A STRUGGLE WITH HOW QUICKLY LOW CLOUDS WILL SCOUR AS
HIGH PRESSURE SHIFTS OFF THE MID ATLANTIC COAST AND LOW LEVEL WINDS
BECOME SOUTH-SOUTHEASTERLY. WITH WESTERLY FLOW ALOFT....WARM
ADVECTION SHOWERS AND STORMS OVER THE HIGHER TERRAIN MAY BE ABLE
TO DRIFT EAST TOWARD THE WESTERN PIEDMONT...BUT COVERAGE SHOULD ONLY
BE ISOLATED. WE WILL CONTINUE TO LEAN TOWARD THE LOW SIDE OF
GUIDANCE FOR HIGHS...WITH LOW 70S NORTHEAST TO UPPER 70S SOUTHWEST.
LOWS MONDAY NIGHT AROUND 60.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 230 AM SUNDAY...
MONDAY IS AGAIN A STRUGGLE WITH HOW QUICKLY LOW CLOUDS WILL SCOUR AS
HIGH PRESSURE SHIFTS OFF THE MID ATLANTIC COAST AND LOW LEVEL WINDS
BECOME SOUTH-SOUTHEASTERLY. WITH WESTERLY FLOW ALOFT....WARM
ADVECTION SHOWERS AND STORMS OVER THE HIGHER TERRAIN MAY BE ABLE
TO DRIFT EAST TOWARD THE WESTERN PIEDMONT...BUT COVERAGE SHOULD ONLY
BE ISOLATED. WE WILL CONTINUE TO LEAN TOWARD THE LOW SIDE OF
GUIDANCE FOR HIGHS...WITH LOW 70S NORTHEAST TO UPPER 70S SOUTHWEST.
LOWS MONDAY NIGHT AROUND 60.
HIGH PRESSURE SURFACE AND ALOFT LOCATED TO OUR SOUTH AT SUNRISE
TUESDAY. A SUBTLE SHORT WAVE IS SURPRISINGLY DEPICTED CONSISTENTLY
ACROSS SEVERAL MODELS FOR THE MID ATLANTIC REGION DURING THE DAY...
INDUCING WEAK SURFACE TROUGHING OVER VIRGINIA AND NORTH CAROLINA.
LOW LEVEL CONVERGENCE IS QUITE WEAK BUT AFTERNOON INSTABILITY...
CAPE AND MID LEVEL TEMPERATURE LAPSE RATES ALL INDICATE CONVECTION
IS A POSSIBILITY. WITH SUCH WEAK FORCING... WILL KEEP CHANCES FOR
THUNDER AT SLIGHT AND IN THE AFTERNOON.
MODEL CONSENSUS ON 1000 TO 850 MILLIBAR THICKNESS TUESDAY AFTERNOON
IN LINE WITH CLIMATOLOGICAL NORMALS FOR EARLY JUNE. CIRRUS CLOUDS
COULD IMPACT AFTERNOON TEMPERATURES... BUT FOR NOW WILL MINIMIZE
THIS AND FORECAST HIGH TEMPERATURES IN THE LOWER 80S NORTHWEST AND
MID 80S ELSEWHERE.
ANY AFTERNOON CONVECTION SHOULD NOT PERSIST PAST LATE EVENING
TUESDAY NIGHT. LOW LEVEL THICKNESSES MORE TYPICAL OF EARLY JUNE
PERSIST. PRECIPITABLE WATERS IN EXCESS OF 1.25 INCHES AND A LIGHT
SOUTHWEST BREEZE WITH PERIODS OF CALM WILL ALLOW TEMPERATURES TO
FALL NO LOWER THAN THE LOWER 60S BY SUNRISE WEDNESDAY.
LOW LEVEL THICKNESSES RISE FIVE TO TEN METERS WEDNESDAY AFTERNOON
OVER THE PREVIOUS DAY AND MIXING HEIGHTS WILL PERHAPS REACH 7000
FEET. MOISTURE IS SOMEWHAT LIMITED... ESPECIALLY TO THE SOUTH. A
WEAK BOUNDARY LOCATED NEAR OR NORTH OF HIGHWAY 64 WILL POTENTIALLY
BE A FOCUS FOR CONVECTION. DUE TO LIMITED MOISTURE WILL KEEP CHANCES
AT SLIGHT FOR MID TO LATE AFTERNOON. DAMAGING DOWNBURST WINDS WILL
BE A RISK DUE TO EVAPORATIVELY COOLED DOWNDRAFTS IF THE ABOVE
SCENARIO HOLDS UP... BUT WITH COVERAGE LIMITED TO ABSENT... NO PLANS
TO MENTION IN THE HAZARDOUS WEATHER OUTLOOK AT THIS TIME. AFTERNOON
THICKNESSES MORE TYPICAL OF MID JULY ARE FORECAST. HIGH TEMPERATURES
MOSTLY MID 80S.
IN SPITE OF THE BOUNDARY IN THE NORTH... ANY CONVECTION LOOKS TO BE
SHORT LIVED ONCE THE HEATING OF THE DAY IS LOST. LOW TEMPERATURES
SHOULD FALL NO LOWER THAN THE LOW TO MID 60S AS 1000 TO 850 MILLIBAR
THICKNESSES REMAIN ABOVE 1400 METERS.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 230 AM SUNDAY...
THE AIR MASS DRYS A BIT THURSDAY IN LIGHT WEST FLOW AS THE UPPER
LEVEL RIDGE OVER THE EASTERN UNITED STATES STRENGTHENS SLIGHTLY.
LATE AFTERNOON CONVECTION NOT IMPOSSIBLE BUT CHANCES LOOK LESS THAN
SLIGHT AT THIS TIME... WITH THE SCENARIO REPEATING FOR FRIDAY AS
WELL. CONTINUE TO FAVOR THE MORE PERSISTENT RIDGE OF THE ECMWF MODEL
THOUGH THE ECMWF DOES RETROGRADE THE RIDGE TO THE MIDWEST THURSDAY
NIGHT AND INTO THE WEEKEND. THIS SHOULD ALLOW AFTERNOON TEMPERATURES
TO SLIP A BIT SATURDAY AND INCREASE AFTERNOON RAIN CHANCES FOR
SATURDAY AFTERNOON.
WELL ABOVE NORMAL TEMPERATURES TO CONTINUE FOR THIS FORECAST PERIOD.
MID TO UPPER 80S THURSDAY AND FRIDAY... LOW TO MID 80S SATURDAY. LOW
TEMPERATURES IN THE LOW TO MID 60S.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 700 AM SUNDAY...
MVFR CEILINGS ARE PREDOMINATE ACROSS ALL OF CENTRAL NC THIS MORNING
AS LOW LEVEL MOISTURE REMAIN LOCKED IN PLACE NORTH OF STATIONARY
FRONT OVER SC. THE EXCEPTION IS OVER THE TRIAD WHERE DRIER AIR HAS
CAUSED THE LOW CLOUDS TO BREAK. MODELS INDICATE THE SHALLOW LAYER OF
LOW LEVEL MOISTURE WILL CONTINUE TO ERODE WITH SOUTH-SOUTHWESTERLY
LOW TO MID LEVEL FLOW TODAY. HOWEVER...MODELS MAY BE ERODING
STRATUS FROM THE SOUTH AND WEST TOO QUICKLY...AS THEY OFTEN DO....SO
MVFR CEILINGS MAY PERSIST WELL INTO THE AFTERNOON FROM KRDU TO
KRWI. WINDS WILL GENERALLY BE LIGHT AND VARIABLE FOR A GOOD PORTION
OF THE DAY BUT WILL BECOME EAST-NORTHEASTERLY AGAIN THIS EVENING AS
HIGH PRESSURE OVER THE GREAT LAKES PUSHES ANOTHER COLD FRONT INTO
THE AREA FROM THE NORTH. THIS COOL STABLE FLOW WILL BRING STRATUS
BACK ACROSS THE AREA ONCE AGAIN TONIGHT AND MONDAY
MORNING...POTENTIALLY WITH PATCHY LIGHT RAIN AT TIMES. -SMITH
OUTLOOK...
MVFR CEILINGS MAY PERSIST INTO THE DAY ON MONDAY...THOUGH AN OVERALL
DRYING TREND IS EXPECTED THROUGH MID WEEK AS AN UPPER LEVEL RIDGE
SETTLES OVER THE REGION. AFTERNOON SHOWERS/STORMS MAY BE POSSIBLE BY
WEDNESDAY BUT VFR CONDITIONS ARE EXPECTED TO PREVAIL FOR MUCH OF THE
WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...SMITH/99
LONG TERM...99
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1256 PM EDT SUN APR 29 2012
.SYNOPSIS...
A NEARLY STATIONARY FRONT ACROSS THE AREA WILL GRADUALLY PUSH
SOUTHWARD BY LATE TONIGHT. BERMUDA HIGH PRESSURE WILL DEVELOP
TUESDAY...BRINGING A MORE SUMMER-LIKE PATTERN AND A WARMING TREND
THROUGH THE REMAINDER OF THE WEEK AND INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1 PM SUNDAY...THE FRONT IS SAGGING SOUTH ACROSS THE CAROLINA
COASTAL WATERS EARLY THIS AFTERNOON...EASILY VISIBLE ON SATELLITE
IMAGERY AS A ROPE CLOUD WRAPPING AROUND THE TIP OF CAPE FEAR. ALMOST
ALL MODELS HAVE CONTINUED TO STRUGGLE WITH THE BEHAVIOR OF THIS
FRONT OVER THE PAST 24-36 HOURS. THE MOST RELIABLE MODELS AS OF THIS
MOMENT APPEAR TO BE THE 12Z RUC AND THE 00Z WRF-NMM. LOW STRATUS
CONTINUES TO FRAGMENT INLAND AS STRONG LATE APRIL SUNSHINE WORKS ON
WARMING THE BOUNDARY LAYER AND STEEPENING LAPSE RATES UP THROUGH THE
CLOUD BASES. SUNNY SKIES FROM FLORENCE AND CONWAY SOUTH WILL ALLOW
TEMPERATURES TO SOAR INTO THE MID TO UPPER 80S TODAY...WHILE TO THE
NORTH A COOLER AND SOMEWHAT CLOUDIER AIRMASS WILL HOLD TEMPERATURES
IN THE MID TO UPPER 70S. THE COOLEST READINGS WILL EXIST ALONG THE
BEACHES NORTH OF CAPE FEAR WHERE TEMPERATURES WILL DO GOOD TO EXCEED
70 DEGREES FOR AN HOUR OR TWO BATTLING THE COOL SEABREEZE. A
SUBSTANTIAL SUBSIDENCE INVERSION BETWEEN 700-800 MB WILL CAP OFF ANY
GROWING CUMULUS WITHIN THE WARMER MORE DEEPLY-MIXED AIRMASS SOUTH OF
THE FRONT.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...TRICKY START TO THE FORECAST PERIOD AS A BACK
DOOR COLD FRONT AND ITS ASSOCIATED BAROCLINIC GRADIENT SHIFT SOUTH
TOWARDS...OR OVER...THE ILM CWA. GUIDANCE CONTINUES TO BACK OFF ON
STRENGTH AND LATITUDINAL PROGRESS OF THIS FRONT...WHICH MAKES SENSE
BASED OFF THE FACT IT IS NEARLY MAY. HOWEVER...EXACT SOUTHERN
DISPLACEMENT OF THIS FRONT WILL MAKE A LARGE DIFFERENCE IN MAX TEMPS
AND CLOUD COVER MONDAY.
GFS/ECMWF IN DECENT AGREEMENT...AND ARE MORE AGGRESSIVE THAN NAM IN
TURNING WINDS E/NE DURING MONDAY WITH A COOL SURGE BEHIND THE FRONT.
WILL FAVOR THIS SOLUTION WHICH SHOWS A SUBTLE DECREASE IN WEDGE
STRENGTH FROM PREVIOUS GUIDANCE...VS THE NAM WHICH IS MUCH WEAKER
WITH FROPA. THIS CREATES A BELOW CLIMO AND MOSTLY CLOUDY DAY AS
MOISTURE IN THE 1000-800MB LAYER GETS TRAPPED BELOW BUILDING UPPER
RIDGING. PRECIP CHANCES LOOK VERY MARGINAL WITH SOME WEAK ISENTROPIC
LIFT ACROSS NORTHERN ZONES...AND WILL KEEP POP SILENT SINCE ANY
RAINFALL MAY NOT EVEN MEASURE A TRACE DURING MONDAY. AS MENTIONED
PREVIOUSLY...TEMPS WILL BE QUITE TRICKY AND HIGHLY DEPENDENT ON
EXACT FRONTAL PLACEMENT...BUT WILL INDICATE MID 70S IN THE FAR
NE...TO AROUND 80 FAR SW. OF COURSE...THESE COULD VARY HIGHLY IF
FRONT DOES NOT BEHAVE AS CURRENTLY ANTICIPATED.
BY LATE MONDAY HIGH PRESSURE DRIFTS OFF THE MID-ATLANTIC AND
SOUTHERLY RETURN FLOW PUSHES THE REMNANT FRONT BACK TO THE NORTH.
WARM AND MOIST AIR FLOODS BACK INTO THE REGION KEEPING MINS MONDAY
NIGHT WELL ABOVE CLIMO...ONLY IN THE LOW 60S.
A MUCH BETTER DAY ON TUESDAY AS HIGH PRESSURE SITS OFFSHORE ALLOWING
FOR A CONTINUATION OF WAA ON SOUTHERLY FLOW. COMBINING THIS WITH
BUILDING HEIGHTS ALOFT MAKES TUESDAY A SLIGHTLY ABOVE CLIMO
DAY...LOW TO MID 80S...UNDER ONLY PARTLY CLOUDY SKY CONDITIONS. MINS
AT NIGHT WILL ONCE AGAIN BE WELL ABOVE CLIMO.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 3 AM SUNDAY...QUIET AND ABOVE NORMAL EARLY-MAY WEATHER
ANTICIPATED INTO THE WEEKEND. LARGE UPPER RIDGE DEVELOPS ACROSS THE
SOUTHEAST AND REMAINS IN PLACE THROUGH AT LEAST FRIDAY. WITH A
SURFACE HIGH ANCHORED OFFSHORE...SURFACE WARM AIR AND A MID LEVEL
CAP WILL CREATE MOSTLY SUNNY AND WARM CONDITIONS THROUGH THE
WEEK...WITH TEMPS WELL INTO THE 80S AWAY FROM THE IMMEDIATE COAST.
THE FAVORED HOT SPOTS MAY APPROACH 90 WED/THU/FRI AS 850MB TEMPS
SOAR TO +17C AND SOME DOWNSLOPE COMPRESSIONAL WARMING AID IN WARMING
THE SURFACE.
FORECAST CONFIDENCE DECREASES FOR SATURDAY AS CENTRAL RIDGING
STRENGTHENS FORMING AN OMEGA TYPE BLOCK ACROSS THE MIDDLE OF THE
COUNTRY. AT THE SAME TIME...ECMWF/GFS SHOW A VORT/UPPER TROUGH
DEVELOPING ON THE SE OF THIS RIDGE ACROSS THE GOM...WHILE A
NORTHERN STREAM S/W TROUGH DROPS OUT OF CANADA ALONG ITS EASTERN
PERIPHERY. THESE FEATURES COULD WORK IN TANDEM TO BREAK DOWN THE
RIDGING FROM THE EAST AND PUSH A COLD FRONT THROUGH THE AREA.
FREQUENTLY GUIDANCE IS TOO FAST IN BREAKING DOWN SUBTROPICAL RIDGES
SO WILL FOR NOW KEEP THE EXTENDED DRY. HOWEVER...MUST NOTE THAT A
DECREASE IN MID LEVEL CAPPING AND INCREASE IN MOISTURE COULD CREATE
DIURNAL CONVECTION FRIDAY...WITH A BETTER CHANCE SATURDAY IF THE
COLD FRONT DOES REACH THIS AREA.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 18Z...LINGERING MVFR AT KILM/KLBT WILL GRADUALLY IMPROVE OVER
THE NEXT HOUR OR SO AS STRATUS FROM THIS MORNING CONTINUES TO BURN
OFF. A NEARLY-STATIONARY FRONT EXTENDS FROM APPX 20 S ILM TO 20 N
CRE TO 25 S LBT. ANTICIPATE CONDITIONS TO BECOME VFR AREA-WIDE THIS
AFTERNOON WITH SCT LOW TO MID LEVEL CLOUDS THROUGH THE EVENING
HOURS...POSSIBLY BECOMING BKN AT TIMES. CURRENT TIME-HEIGHT ANALYSIS
DEPICTS MOIST LOW-LEVELS OVERNIGHT INTO THE MORNING HOURS MONDAY. WE
HAVE BROUGHT MVFR/IFR BACK INTO THE FORECAST LATE TONIGHT DUE TO LOW
STRATUS WITH POTENTIAL FOG DEVELOPMENT (3SM) AT A FEW SITES...AND
POSSIBLY LOWER. THE SEA BREEZE WILL ALLOW WINDS ALONG THE COAST AND
FARTHER INLAND TO BECOME SOUTHEAST LATER THIS AFTERNOON WITH
SUSTAINED WINDS LESS THAN 12KTS.
EXTENDED OUTLOOK...A SLIGHT CHANCE OF MVFR/SHOWERS THROUGH TUESDAY.
LOW CONFIDENCE IFR VSBYS IN MORNING FOG TUESDAY AND WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1 PM SATURDAY...VISIBLE SATELLITE IMAGERY SHOWS THE COLD FRONT
DROPPING SOUTH PAST BALD HEAD ISLAND EARLY THIS AFTERNOON...WITH
NORTHEAST 10-15 KT WINDS FOLLOWING BEHIND TO THE NORTH. SOUTH OF THE
FRONT A VERY LIGHT WEST WIND SHOULD TURN FIRMLY ONSHORE WITHIN THE
NEXT HOUR OR TWO DUE TO A DEVELOPING SEABREEZE CIRCULATION. OTHER
THAN THE VARYING WIND DIRECTIONS IN THE VICINITY OF THE FRONT NO
SIGNIFICANT WEATHER IS EXPECTED THIS AFTERNOON. SEAS RANGE FROM 1 TO
2 FT WEST OF CAPE FEAR...AND AROUND 2 FT EAST OF CAPE FEAR...WITH
DOMINANT PERIODS 6-7 SECONDS.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...BACK DOOR COLD FRONT DROPS SOUTH ACROSS AT
LEAST THE NORTHERN WATERS MONDAY...BUT MAY NOT MAKE IT ALL THE WAY
SOUTH THROUGH AMZ256 DURING THE DAY. ALTHOUGH A DECENT NE SURGE IS
LIKELY ACROSS THE NC WATERS DURING MONDAY...WITH E/NE WINDS
INCREASING TO 10-15 KTS...THE SOUTHERN WATERS WILL SEE WINDS ONLY
AROUND 10 KTS...MORE FROM THE EAST THAN NE. WAVE HEIGHTS WILL BE
PREDOMINATELY WIND DRIVEN...WITH A 2-3 FT NE WIND CHOP ACROSS THE NC
WATERS...AND 2-3 FT CONFUSED SEAS IN THE SOUTH. BY LATE
MONDAY...FRONT RETURNS TO THE NORTH AS HIGH PRESSURE PUSHES OFFSHORE
THE MID ATLANTIC. THIS TURNS WINDS TO THE SE...THEN SOUTH ON TUESDAY
AT AROUND 10 KTS. SEAS BUILD TO 3-4 FT THROUGH THE END OF THE
PERIOD...WITH A WEAK SOUTH WIND WAVE OVER TOPPING AN INCREASING 8
SECOND SE SWELL.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3 AM SUNDAY...RATHER UNIFORM WIND/WAVE CONDITIONS WILL
CONTROL THE EXTENDED AS HIGH PRESSURE OFFSHORE CREATES S/SW RETURN
FLOW ACROSS THE WATERS. OTHER THAN SLIGHT DIURNAL CHANGES EACH
DAY...SW WINDS AROUND 10 KTS PERSIST THROUGH THURSDAY. THE ONLY
NOTICEABLE DIFFERENCE THROUGH THE EXTENDED WILL BE AN INCREASING SE
SWELL DUE TO ELONGATED EASTERLY FETCH AROUND THE SOUTH SIDE OF
BERMUDA HIGH PRESSURE. SEAS OF 2-4 FT PERSIST THROUGH THE
EXTENDED...AND EVEN THOUGH A LIGHT WIND CHOP WILL BE EVIDENT...THE
SWELL WILL DOMINATE THE WAVE SPECTRUM.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...SGL/TRA
AREA FORECAST DISCUSSION
NWS RALEIGH NC
700 AM EDT SUN APR 29 2012
.SYNOPSIS...
HIGH PRESSURE OVER EASTERN GREAT LAKES AND NEW ENGLAND WILL MOVE
OFFSHORE TODAY....ALLOWING A NEARLY STATIONARY FRONT OVER SOUTH
CAROLINA TO RETURN NORTH AS A WARM FRONT. A COLD FRONT WILL MOVE
BACK SOUTH ACROSS NORTH CAROLINA THIS AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
AS OF 305 AM SUNDAY...
MOSTLY A TEMPERATURE FORECAST TODAY...AND WITH LOW FORECASTER
CONFIDENCE BASED ON UNCERTAINTY IN THE EROSION OF THE WIDESPREAD
STRATUS AND POOR MODEL PERFORMANCE WITH THE RESIDUAL WEDGE AIRMASS
OVER THE AREA. THE WEDGE BOUNDARY REMAINS STATIONARY OVER SC THIS
MORNING...WITH HIGH PRESSURE OVER EASTERN CANADA BEGINNING TO NOSE
SOUTH ACROSS THE GREAT LAKES TOWARD THE OUR AREA. THE STRATUS
LAYER CONTINUES BE RATHER THIN...ONLY A FEW HUNDRED FEET
DEEP...BUT THERE HAS BEEN NO SIGNIFICANT MECHANISM TO HELP ERODE
THE CLOUDS. MODELS MAY ONCE AGAIN BE TOO AGGRESSIVE IN SHOWING
SOUTHWESTERLY LOW LEVEL FLOW DEVELOPING THIS MORNING...WHICH WOULD
LEAD TO FASTER SCATTERING OF CLOUD BY MID-MORNING. FORECAST
1000-850MB THICKNESSES RANGE FROM 1360M IN THE NORTHEAST TO NEAR
1400M IN THE SOUTHWEST. 1400M WOULD SUPPORT HIGHS IN THE MID 80S IN
THE SOUTHWEST UNDER FULL SUN...AND THE MAV GUIDANCE EVEN HAS
VALUES AS HIGH AS 88 OVER THE SOUTHERN PIEDMONT. HOWEVER...GIVEN
THAT THE NAM/GFS HAVE STRUGGLED SO MUCH WITH THIS WEDGE AIRMASS
OVER THE PAST 24 HOURS...AND ALSO THAT RECENT HRRR RUNS SHOW
STRATUS LINGERING THROUGH LATER MORNING...CONFIDENCE IS JUST NOT
HIGH ENOUGH TO FORECAST MID 80S IN THE SOUTHWEST. WE WILL KEEP
FORECAST HIGHS IN THE UPPER 60S IN THE NORTHEAST WHERE STRATUS
WILL LINGER THROUGH MUCH OF THE DAY...TO AROUND 80 IN THE
SOUTHWEST.
IF THE CLOUDS DO BREAK BY MIDDAY AND LOW TO MID 80S CAN BE
REACHED...STEEP MID LEVEL LAPSE RATES AROUND 7-7.5 C/KM WOULD HELP
TO SUPPORT 500-1000 J/KG OF MLCAPE SOUTHERN PIEDMONT.B
HOWEVER...FORECAST SOUNDINGS ALSO SHOW A DECENT CAP JUST ABOVE
800MB. THE MID LEVEL RIDGE AXIS THAT IS CURRENTLY WEST OF THE
MOUNTAINS WILL BE INCHING EASTWARD...AND LOW LEVEL FORCING WILL BE
WEAK TO NON-EXISTENT...SO WE WILL LEAVE THE FORECAST DRY FOR TODAY.
TONIGHT...SURFACE HIGH PRESSURE WILL BUILD OVER THE GREAT LAKES AND
EXTEND SOUTHEAST INTO VA AND NC. THIS WILL HELP SUPPLY ANOTHER SHOT
OF COOL AND MOIST NORTHEASTERLY LOW LEVEL FLOW...WITH STRATUS LIKELY
TO SURGE BACK IN ACROSS THE AREA. WITH THE MID LEVEL RIDGE BUILDING
OVERHEAD AND INCREASING MOISTURE BELOW THE SUBSIDENCE
INVERSION...FORECAST SOUNDINGS SHOW QUITE A BIT OF VEERING LOW
LEVEL WINDS AND WARM ADVECTION OVERNIGHT...WHICH MAY LEAD TO PATCHY
LIGHT RAIN AND/OR DRIZZLE. LOWS IN THE MID 50S NORTHEAST TO AROUND
60 SOUTHWEST.
MONDAY IS AGAIN A STRUGGLE WITH HOW QUICKLY LOW CLOUDS WILL SCOUR AS
HIGH PRESSURE SHIFTS OFF THE MID ATLANTIC COAST AND LOW LEVEL WINDS
BECOME SOUTH-SOUTHEASTERLY. WITH WESTERLY FLOW ALOFT....WARM
ADVECTION SHOWERS AND STORMS OVER THE HIGHER TERRAIN MAY BE ABLE
TO DRIFT EAST TOWARD THE WESTERN PIEDMONT...BUT COVERAGE SHOULD ONLY
BE ISOLATED. WE WILL CONTINUE TO LEAN TOWARD THE LOW SIDE OF
GUIDANCE FOR HIGHS...WITH LOW 70S NORTHEAST TO UPPER 70S SOUTHWEST.
LOWS MONDAY NIGHT AROUND 60.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 230 AM...
HIGH PRESSURE SURFACE AND ALOFT LOCATED TO OUR SOUTH AT SUNRISE
TUESDAY. A SUBTLE SHORT WAVE IS SURPRISINGLY DEPICTED CONSISTENTLY
ACROSS SEVERAL MODELS FOR THE MID ATLANTIC REGION DURING THE DAY...
INDUCING WEAK SURFACE TROUGHING OVER VIRGINIA AND NORTH CAROLINA.
LOW LEVEL CONVERGENCE IS QUITE WEAK BUT AFTERNOON INSTABILITY...
CAPE AND MID LEVEL TEMPERATURE LAPSE RATES ALL INDICATE CONVECTION
IS A POSSIBILITY. WITH SUCH WEAK FORCING... WILL KEEP CHANCES FOR
THUNDER AT SLIGHT AND IN THE AFTERNOON.
MODEL CONSENSUS ON 1000 TO 850 MILLIBAR THICKNESS TUESDAY AFTERNOON
IN LINE WITH CLIMATOLOGICAL NORMALS FOR EARLY JUNE. CIRRUS CLOUDS
COULD IMPACT AFTERNOON TEMPERATURES... BUT FOR NOW WILL MINIMALIZE
THIS AND FORECAST HIGH TEMPERATURES IN THE LOWER 80S NORTHWEST AND
MID 80S ELSEWHERE.
ANY AFTERNOON CONVECTION SHOULD NOT PERSIST PAST LATE EVENING
TUESDAY NIGHT. LOW LEVEL THICKNESSES MORE TYPICAL OF EARLY JUNE
PERSIST. PRECIPITABLE WATERS IN EXCESS OF 1.25 INCHES AND A LIGHT
SOUTHWEST BREEZE WITH PERIODS OF CALM WILL ALLOW TEMPERATURES TO
FALL NO LOWER THAN THE LOWER 60S BY SUNRISE WEDNESDAY.
LOW LEVEL THICKNESSES RISE FIVE TO TEN METERS WEDNESDAY AFTERNOON
OVER THE PREVIOUS DAY AND MIXING HEIGHTS WILL PERHAPS REACH 7000
FEET. MOISTURE IS SOMEWHAT LIMITED... ESPECIALLY TO THE SOUTH. A
WEAK BOUNDARY LOCATED NEAR OR NORTH OF HIGHWAY 64 WILL POTENTIALLY
BE A FOCUS FOR CONVECTION. DUE TO LIMITED MOISTURE WILL KEEP CHANCES
AT SLIGHT FOR MID TO LATE AFTERNOON. DAMAGING DOWNBURST WINDS WILL
BE A RISK DUE TO EVAPORATIVELY COOLED DOWNDRAFTS IF THE ABOVE
SCENARIO HOLDS UP... BUT WITH COVERAGE LIMITED TO ABSENT... NO PLANS
TO MENTION IN THE HAZARDOUS WEATHER OUTLOOK AT THIS TIME. AFTERNOON
THICKNESSES MORE TYPICAL OF MID JULY ARE FORECAST. HIGH TEMPERATURES
MOSTLY MID 80S.
IN SPITE OF THE BOUNDARY IN THE NORTH... ANY CONVECTION LOOKS TO BE
SHORT LIVED ONCE THE HEATING OF THE DAY IS LOST. LOW TEMPERATURES
SHOULD FALL NO LOWER THAN THE LOW TO MID 60S AS 1000 TO 850 MILLIBAR
THICKNESSES REMAIN ABOVE 1400 METERS.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 230 AM...
THE AIR MASS DRYS A BIT THURSDAY IN LIGHT WEST FLOW AS THE UPPER
LEVEL RIDGE OVER THE EASTERN UNITED STATES STRENGTHENS SLIGHTLY.
LATE AFTERNOON CONVECTION NOT IMPOSSIBLE BUT CHANCES LOOK LESS THAN
SLIGHT AT THIS TIME... WITH THE SCENARIO REPEATING FOR FRIDAY AS
WELL. CONTINUE TO FAVOR THE MORE PERSISTENT RIDGE OF THE ECMWF MODEL
THOUGH THE ECMWF DOES RETROGRADE THE RIDGE TO THE MIDWEST THURSDAY
NIGHT AND INTO THE WEEKEND. THIS SHOULD ALLOW AFTERNOON TEMPERATURES
TO SLIP A BIT SATURDAY AND INCREASE AFTERNOON RAIN CHANCES FOR
SATURDAY AFTERNOON.
WELL ABOVE NORMAL TEMPERATURES TO CONTINUE FOR THIS FORECAST PERIOD.
MID TO UPPER 80S THURSDAY AND FRIDAY... LOW TO MID 80S SATURDAY. LOW
TEMPERATURES IN THE LOW TO MID 60S.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 700 AM SUNDAY...
MVFR CEILINGS ARE PREDOMINATE ACROSS ALL OF CENTRAL NC THIS MORNING
AS LOW LEVEL MOISTURE REMAIN LOCKED IN PLACE NORTH OF STATIONARY
FRONT OVER SC. THE EXCEPTION IS OVER THE TRIAD WHERE DRIER AIR HAS
CAUSED THE LOW CLOUDS TO BREAK. MODELS INDICATE THE SHALLOW LAYER OF
LOW LEVEL MOISTURE WILL CONTINUE TO ERODE WITH SOUTH-SOUTHWESTERLY
LOW TO MID LEVEL FLOW TODAY. HOWEVER...MODELS MAY BE ERODING
STRATUS FROM THE SOUTH AND WEST TOO QUICKLY...AS THEY OFTEN DO....SO
MVFR CEILINGS MAY PERSIST WELL INTO THE AFTERNOON FROM KRDU TO
KRWI. WINDS WILL GENERALLY BE LIGHT AND VARIABLE FOR A GOOD PORTION
OF THE DAY BUT WILL BECOME EAST-NORTHEASTERLY AGAIN THIS EVENING AS
HIGH PRESSURE OVER THE GREAT LAKES PUSHES ANOTHER COLD FRONT INTO
THE AREA FROM THE NORTH. THIS COOL STABLE FLOW WILL BRING STRATUS
BACK ACROSS THE AREA ONCE AGAIN TONIGHT AND MONDAY
MORNING...POTENTIALLY WITH PATCHY LIGHT RAIN AT TIMES. -SMITH
OUTLOOK...
MVFR CEILINGS MAY PERSIST INTO THE DAY ON MONDAY...THOUGH AN OVERALL
DRYING TREND IS EXPECTED THROUGH MID WEEK AS AN UPPER LEVEL RIDGE
SETTLES OVER THE REGION. AFTERNOON SHOWERS/STORMS MAY BE POSSIBLE BY
WEDNESDAY BUT VFR CONDITIONS ARE EXPECTED TO PREVAIL FOR MUCH OF THE
WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...SMITH
SHORT TERM...SMITH/99
LONG TERM...99
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
345 AM EDT SUN APR 29 2012
.SYNOPSIS...
A STATIONARY FRONT OVER SOUTH CAROLINA WILL MOVE BRIEFLY NORTH
ALONG THE COAST AS A WARM FRONT TONIGHT BEFORE MOVING BACK SOUTH
AS A COLD FRONT ON SUNDAY AND SUNDAY NIGHT. THE FRONT SHOULD
DISSIPATE SOUTH OF THE AREA MONDAY AS HIGH PRESSURE BUILDS IN FROM
THE EAST TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1240 AM SUN...UPDATED FOR CURRENT PT CLDY SKIES OVER SRN HALF
OF AREA...AND DROPPED POPS UNTIL AFTER 2 A FOR NRN SECTIONS. ALSO
LOWERED MIN TEMPS BASEDO ON CURRENT OBS AS EVENING CLEARING ALLOWED
MORE COOLING.
/PREVIOUS DISCUSSION/
AS OF 955 PM SATURDAY...THE LOW CLOUDS HAVE DISSIPATED MUCH FASTER
AND OVER A MORE WIDESPREAD AREA THAN PREVIOUSLY EXPECTED THIS
EVENING. PERHAPS THIS IS DUE IN PART TO SUBSIDENCE SEEN IN THE OMEGA
FORECASTS AS A WEAK LOW MOVES AWAY FROM THE NC COAST. BOTH THE 00Z
GSO AND MHX SOUNDINGS WERE DEEPLY SATURATED IN THE LOW
LEVELS...EXHIBITED SHARP LOW LEVEL INVERSIONS...AND LOW LEVEL
EASTERLY FLOW...ALL SUGGESTIVE OF CONDITIONS FAVORABLE FOR LOW CLOUD
REDEVELOPMENT LATER TONIGHT. THE 18Z NAM-12 FORECAST SOUNDINGS STILL
SUPPORTED LOW CLOUDS BUT WITH SHALLOWER LOW LEVEL MOISTURE. GIVEN A
SURFACE PATTERN INDICATIVE OF HYBRID DAMMING AND THE ABOVE FACTORS I
AM STILL EXPECTING WIDESPREAD LOW CLOUDS BUT NOT WITH AS MUCH
CONFIDENCE AS BEFORE. REMNANT SHOWERS FROM AN UPSTREAM MCS COULD
AFFECT THE NORTHERN PORTION OF THE AREA LATE SO WILL MAINTAIN 20-30%
POPS NORTH FOR LATE TONIGHT.
THE STATIONARY BOUNDARY CURRENTLY LOCATED FROM NORTHEAST SOUTH
CAROLINA INTO EXTREME SOUTHEAST NORTH CAROLINA IS STILL EXPECTED
TO LIFT NORTH OVERNIGHT...MAINLY ALONG THE IMMEDIATE COAST. THIS
WILL RESULT IN THE FLOW TURNING FROM EASTERLY TO SOUTHWEST ALONG
AND NEAR THE COAST. FURTHER INLAND A HYBRID DAMMING PATTERN WILL
REMAIN AND RETARD THE NORTHWARD MOVEMENT OF THE RETREATING
BOUNDARY WITH NORTHERLY FLOW PERSISTING. STILL EXPECTING LOW
TEMPERATURES 53 TO 58 INLAND WITH TEMPERATURES BRIEFLY RISING
ALONG THE COAST SHOULD THE SW FLOW MATERIALIZE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
AS OF 245 PM SATURDAY...THE COLD FRONT WILL DRIVE TO THE SOUTH OF
THE AREA AGAIN ON SUNDAY WITH THE NAM12 AND GFS SHOWING A BROKEN
BAND OF MOISTURE AND AGAIN A SMALL POP IN THE FORECAST WITH VERY
LIGHT QPF. BUFKIT SOUNDINGS SHOW A GOOD DEAL OF MOISTURE BELOW
2000 FEET WITH THE LOW-LEVEL NORTHEAST FLOW...SO AGAIN EXPECT A
MOSTLY CLOUDY DAY ON SUNDAY WITH JUST OCCASIONAL PEAKS OF
SUNSHINE. THE BEST CHANCE OF GETTING SUNSHINE WOULD BE OVER THE
FAR SOUTHWESTERN COUNTIES WHERE SOME TEMPERATURES NEAR 80 WILL BE
POSSIBLE. OVER MUCH OF THE REMAINDER OF THE CWA...HIGHS WILL RANGE
FROM 65 TO ABOUT 72 DEGREES.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 330 AM SAT...BIG STORY THROUGH THE LONG TERM WILL BE THE DRY
AND VERY WARM CONDITIONS. THE BEGINNING OF THE WORK WEEK WILL
START OUT RATHER CLOUDY WITH TEMPS NEAR AVERAGE. STALLED FRONTAL
BOUNDARY WILL FINALLY LIFT NORTH AS SFC HIGH PRES MOVES OFFSHORE
AND UPR RIDGE BEGINS TO BUILD. CLOUDS SHOULD SCOUR OUT ESP ACROSS
SW AREAS BY AFTERNOON...AND ALLOW FOR TEMPS TO CLIMB INTO THE
MID/UPR 70S HERE. A BIT MORE CLOUDS WILL HOLD TEMPS NEAR 70 FOR NE
AREAS. TEMPS WILL BE MILD IN THE LOW 60S MON NIGHT.
SW FLOW INC ON TUE AND WITH PLENTY OF SUN TEMPS RISE INTO THE MID
80S. SOME INDICATION THAT SHORTWAVE ENERGY WILL MOVE THROUGH THE
MID ATLANTIC/VA...AND COULD SPELL A FEW AFTERNOON THUNDERSHOWERS
ACROSS NRN FA. LEFT IN SLIGHT CHANCE POPS TO ACCOUNT FOR THIS
POSSIBILITY. SREF AND 29/00Z ECM HOWEVER HAVE A MORE AMPLIFIED UPR
RIDGE AND KEEP ENTIRE AREA DRY.
TEMPS REALLY SKYROCKET WED INTO LATE IN THE WEEK...AS LOW LEVEL
THICKNESSES SOAR ABOVE 1400M. BOTH ECM AND GFS FCST MAX TEMPS IN
THE MID/UPR 80S. TEMPS IN ACTUALLITY MAY BE A BIT HIGHER...NEAR
90...AS MOS TRENDS TOWARDS CLIMO IN THE LONG RANGE. CHANCES FOR
PRECIP ARE NEARLY NON EXISTANT AS LARGE RIDGE WILL BE CENTERED
OVER E NC. EVEN SEA BREEZE ACTIVITY WILL BE VERY LIMITED DUE TO
THE SW COMPONENT SFC FLOW.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /06Z SUNDAY THROUGH 06Z MONDAY/
AS OF 130 AM SUNDAY...MVFR CIGS REDEVELOPING OVER MOST OF AREA AND
EXPECTED TO PERSIST THROUGH MOST OF DAY WITH ANOTHER SURGE OF LOW
LVL NE WINDS AS WEAK LOW PRES MOVES OFFSHORE. SCT SHOWERS FROM
CURRENT MCS ACTIVITY OVER OH VLY MAY CLIP NRN SECTIONS AROUND 12Z
BUT MAINLY NE OF TAF SITES. WITH TYPICAL LOWERING OF CIGS
OVERNIGHT...PERIOD OF IFR LIKELY MOST SITES 09Z-13Z...THEN RAISING
BACK TO MVFR FOR MID MORNING UNTIL LATE AFTN. PERIOD OF VFR FOR LATE
AFTN INTO EVENING...THEN MVFR REDEVELOPING.
LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 330 AM SUN...MAINLY VFR CONDITIONS THROUGH THE LONG TERM AS
HIGH PRES MOVES OFFSHORE AND CLOUDS SCOUR ON MON. COULD BE SOME
LINGERING MVFR MON MORNING BEFORE DOING SO HOWEVER. TUE THROUGH
THE END OF THE WEEK WILL BE MOSTLY SUNNY WITH SOME PATCHY BR
POSSIBLE EACH AND EVERY NIGHT AS DEWPOINTS CLIMB INTO THE LOWER
60S AND WINDS ARE LIGHT.
&&
.MARINE...
SHORT TERM /THROUGH SUNDAY/...
AS OF 1240 AM SUN...LATEST NAM AND RUC HAVE DECENT HANDLE ON CURRENT
WINDS AND USED THEM FOR UPDATE. WEAK LOW MOVING OFF NRN WATERS IS
PRODUCING NW TO N WINDS 15 KT OR LESS MOST OF AREA...WITH A BRIEF
N-NE SURGE EXPECTED TO DEVELOP OVER NRN WATERS TOWARD MORNING AS LOW
MOVES NE. ALSO ADJUSTED SEAS AS HEIGHTS STILL RUNNING 4-5 FEET OVER
NRN WATERS PER WAVERIDER BUOYS.
/PREVIOUS DISCUSSION/
AS OF 955 PM SATURDAY...COMPLICATED WIND DIRECTION FORECAST BUT
FORTUNATELY WIND SPEEDS ARE FORECAST TO BE 15 KT OR LESS THROUGH
SUNDAY. A WEAK WAVE OF LOW PRESSURE ALONG THE STATIONARY FRONT WAS
LOCATED OFF OF THE OUTER BANKS. THIS LOW IS FORECAST TO MOVE WELL
OFF THE COAT OVERNIGHT AND THE GUIDANCE IS IN AGREEMENT THAT THE
FRONT WILL LIFT NORTH ALONG THE COAST WITH THE FLOW SHIFTING FROM
EASTERLY TO SOUTHWEST OVERNIGHT WHILE INLAND A HYBRID DAMMING
PATTERN REMAINS. THE FRONT IS THEN FORECAST TO DRIFT BACK SOUTH
THROUGH ALL THE WATERS DURING THE DAY ON SUNDAY WITH THE FLOW
TURNING BACK TO THE NORTH AND NORTHEAST. SEAS ARE FORECAST TO BE
IN THE 2 TO 4 FOOT RANGE. NO SMALL CRAFT ADVISORIES ARE ANTICIPATED.
LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 330 AM SUN...SEAS AND WINDS MAINLY BELOW SCA RANGE THROUGH
THE PERIOD. WINDS WILL TRANSLATE FROM EAST TO SOUTH ON MON AS HIGH
PRES MOVES OFFSHORE. SW FLOW WILL THEN PERSIST FROM MON NIGHT
THROUGH THE END OF THE WEEK AS UPR RIDGE BUILDS IN WITH SFC HIGH
ANCHORED OFFSHORE. WINDS MAY APPROACH SCA BRIEFLY FOR THE OUTER
WATERS TUE AFTERNOON AND EVENING AS A SHORTWAVE PASSES BY TO THE
NORTH.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CTC/JME
NEAR TERM...CTC/JME/LEP
SHORT TERM...CTC
LONG TERM...TL
AVIATION...CTC/JME/TL
MARINE...CTC/JME/TL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
313 AM EDT SUN APR 29 2012
.SYNOPSIS...
HIGH PRESSURE OVER EASTERN GREAT LAKES AND NEW ENGLAND WILL MOVE
OFFSHORE TODAY....ALLOWING A NEARLY STATIONARY FRONT OVER SOUTH
CAROLINA TO RETURN NORTH AS A WARM FRONT. A COLD FRONT WILL MOVE
BACK SOUTH ACROSS NORTH CAROLINA THIS AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
AS OF 305 AM SUNDAY...
MOSTLY A TEMPERATURE FORECAST TODAY...AND WITH LOW FORECASTER
CONFIDENCE BASED ON UNCERTAINTY IN THE EROSION OF THE WIDESPREAD
STRATUS AND POOR MODEL PERFORMANCE WITH THE RESIDUAL WEDGE AIRMASS
OVER THE AREA. THE WEDGE BOUNDARY REMAINS STATIONARY OVER SC THIS
MORNING...WITH HIGH PRESSURE OVER EASTERN CANADA BEGINNING TO NOSE
SOUTH ACROSS THE GREAT LAKES TOWARD THE OUR AREA. THE STRATUS
LAYER CONTINUES BE RATHER THIN...ONLY A FEW HUNDRED FEET
DEEP...BUT THERE HAS BEEN NO SIGNIFICANT MECHANISM TO HELP ERODE
THE CLOUDS. MODELS MAY ONCE AGAIN BE TOO AGGRESSIVE IN SHOWING
SOUTHWESTERLY LOW LEVEL FLOW DEVELOPING THIS MORNING...WHICH WOULD
LEAD TO FASTER SCATTERING OF CLOUD BY MID-MORNING. FORECAST
1000-850MB THICKNESSES RANGE FROM 1360M IN THE NORTHEAST TO NEAR
1400M IN THE SOUTHWEST. 1400M WOULD SUPPORT HIGHS IN THE MID 80S IN
THE SOUTHWEST UNDER FULL SUN...AND THE MAV GUIDANCE EVEN HAS
VALUES AS HIGH AS 88 OVER THE SOUTHERN PIEDMONT. HOWEVER...GIVEN
THAT THE NAM/GFS HAVE STRUGGLED SO MUCH WITH THIS WEDGE AIRMASS
OVER THE PAST 24 HOURS...AND ALSO THAT RECENT HRRR RUNS SHOW
STRATUS LINGERING THROUGH LATER MORNING...CONFIDENCE IS JUST NOT
HIGH ENOUGH TO FORECAST MID 80S IN THE SOUTHWEST. WE WILL KEEP
FORECAST HIGHS IN THE UPPER 60S IN THE NORTHEAST WHERE STRATUS
WILL LINGER THROUGH MUCH OF THE DAY...TO AROUND 80 IN THE
SOUTHWEST.
IF THE CLOUDS DO BREAK BY MIDDAY AND LOW TO MID 80S CAN BE
REACHED...STEEP MID LEVEL LAPSE RATES AROUND 7-7.5 C/KM WOULD HELP
TO SUPPORT 500-1000 J/KG OF MLCAPE SOUTHERN PIEDMONT.B
HOWEVER...FORECAST SOUNDINGS ALSO SHOW A DECENT CAP JUST ABOVE
800MB. THE MID LEVEL RIDGE AXIS THAT IS CURRENTLY WEST OF THE
MOUNTAINS WILL BE INCHING EASTWARD...AND LOW LEVEL FORCING WILL BE
WEAK TO NON-EXISTENT...SO WE WILL LEAVE THE FORECAST DRY FOR TODAY.
TONIGHT...SURFACE HIGH PRESSURE WILL BUILD OVER THE GREAT LAKES AND
EXTEND SOUTHEAST INTO VA AND NC. THIS WILL HELP SUPPLY ANOTHER SHOT
OF COOL AND MOIST NORTHEASTERLY LOW LEVEL FLOW...WITH STRATUS LIKELY
TO SURGE BACK IN ACROSS THE AREA. WITH THE MID LEVEL RIDGE BUILDING
OVERHEAD AND INCREASING MOISTURE BELOW THE SUBSIDENCE
INVERSION...FORECAST SOUNDINGS SHOW QUITE A BIT OF VEERING LOW
LEVEL WINDS AND WARM ADVECTION OVERNIGHT...WHICH MAY LEAD TO PATCHY
LIGHT RAIN AND/OR DRIZZLE. LOWS IN THE MID 50S NORTHEAST TO AROUND
60 SOUTHWEST.
MONDAY IS AGAIN A STRUGGLE WITH HOW QUICKLY LOW CLOUDS WILL SCOUR AS
HIGH PRESSURE SHIFTS OFF THE MID ATLANTIC COAST AND LOW LEVEL WINDS
BECOME SOUTH-SOUTHEASTERLY. WITH WESTERLY FLOW ALOFT....WARM
ADVECTION SHOWERS AND STORMS OVER THE HIGHER TERRAIN MAY BE ABLE
TO DRIFT EAST TOWARD THE WESTERN PIEDMONT...BUT COVERAGE SHOULD ONLY
BE ISOLATED. WE WILL CONTINUE TO LEAN TOWARD THE LOW SIDE OF
GUIDANCE FOR HIGHS...WITH LOW 70S NORTHEAST TO UPPER 70S SOUTHWEST.
LOWS MONDAY NIGHT AROUND 60.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 230 AM...
HIGH PRESSURE SURFACE AND ALOFT LOCATED TO OUR SOUTH AT SUNRISE
TUESDAY. A SUBTLE SHORT WAVE IS SURPRISINGLY DEPICTED CONSISTENTLY
ACROSS SEVERAL MODELS FOR THE MID ATLANTIC REGION DURING THE DAY...
INDUCING WEAK SURFACE TROUGHING OVER VIRGINIA AND NORTH CAROLINA.
LOW LEVEL CONVERGENCE IS QUITE WEAK BUT AFTERNOON INSTABILITY...
CAPE AND MID LEVEL TEMPERATURE LAPSE RATES ALL INDICATE CONVECTION
IS A POSSIBILITY. WITH SUCH WEAK FORCING... WILL KEEP CHANCES FOR
THUNDER AT SLIGHT AND IN THE AFTERNOON.
MODEL CONSENSUS ON 1000 TO 850 MILLIBAR THICKNESS TUESDAY AFTERNOON
IN LINE WITH CLIMATOLOGICAL NORMALS FOR EARLY JUNE. CIRRUS CLOUDS
COULD IMPACT AFTERNOON TEMPERATURES... BUT FOR NOW WILL MINIMALIZE
THIS AND FORECAST HIGH TEMPERATURES IN THE LOWER 80S NORTHWEST AND
MID 80S ELSEWHERE.
ANY AFTERNOON CONVECTION SHOULD NOT PERSIST PAST LATE EVENING
TUESDAY NIGHT. LOW LEVEL THICKNESSES MORE TYPICAL OF EARLY JUNE
PERSIST. PRECIPITABLE WATERS IN EXCESS OF 1.25 INCHES AND A LIGHT
SOUTHWEST BREEZE WITH PERIODS OF CALM WILL ALLOW TEMPERATURES TO
FALL NO LOWER THAN THE LOWER 60S BY SUNRISE WEDNESDAY.
LOW LEVEL THICKNESSES RISE FIVE TO TEN METERS WEDNESDAY AFTERNOON
OVER THE PREVIOUS DAY AND MIXING HEIGHTS WILL PERHAPS REACH 7000
FEET. MOISTURE IS SOMEWHAT LIMITED... ESPECIALLY TO THE SOUTH. A
WEAK BOUNDARY LOCATED NEAR OR NORTH OF HIGHWAY 64 WILL POTENTIALLY
BE A FOCUS FOR CONVECTION. DUE TO LIMITED MOISTURE WILL KEEP CHANCES
AT SLIGHT FOR MID TO LATE AFTERNOON. DAMAGING DOWNBURST WINDS WILL
BE A RISK DUE TO EVAPORATIVELY COOLED DOWNDRAFTS IF THE ABOVE
SCENARIO HOLDS UP... BUT WITH COVERAGE LIMITED TO ABSENT... NO PLANS
TO MENTION IN THE HAZARDOUS WEATHER OUTLOOK AT THIS TIME. AFTERNOON
THICKNESSES MORE TYPICAL OF MID JULY ARE FORECAST. HIGH TEMPERATURES
MOSTLY MID 80S.
IN SPITE OF THE BOUNDARY IN THE NORTH... ANY CONVECTION LOOKS TO BE
SHORT LIVED ONCE THE HEATING OF THE DAY IS LOST. LOW TEMPERATURES
SHOULD FALL NO LOWER THAN THE LOW TO MID 60S AS 1000 TO 850 MILLIBAR
THICKNESSES REMAIN ABOVE 1400 METERS.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 230 AM...
THE AIR MASS DRYS A BIT THURSDAY IN LIGHT WEST FLOW AS THE UPPER
LEVEL RIDGE OVER THE EASTERN UNITED STATES STRENGTHENS SLIGHTLY.
LATE AFTERNOON CONVECTION NOT IMPOSSIBLE BUT CHANCES LOOK LESS THAN
SLIGHT AT THIS TIME... WITH THE SCENARIO REPEATING FOR FRIDAY AS
WELL. CONTINUE TO FAVOR THE MORE PERSISTENT RIDGE OF THE ECMWF MODEL
THOUGH THE ECMWF DOES RETROGRADE THE RIDGE TO THE MIDWEST THURSDAY
NIGHT AND INTO THE WEEKEND. THIS SHOULD ALLOW AFTERNOON TEMPERATURES
TO SLIP A BIT SATURDAY AND INCREASE AFTERNOON RAIN CHANCES FOR
SATURDAY AFTERNOON.
WELL ABOVE NORMAL TEMPERATURES TO CONTINUE FOR THIS FORECAST PERIOD.
MID TO UPPER 80S THURSDAY AND FRIDAY... LOW TO MID 80S SATURDAY. LOW
TEMPERATURES IN THE LOW TO MID 60S.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
AS OF 145 AM SUNDAY...
MVFR CEILINGS ARE PREDOMINATE ACROSS ALL OF CENTRAL NC THIS MORNING
AS LOW LEVEL MOISTURE REMAIN LOCKED IN PLACE NORTH OF STATIONARY
FRONT OVER SC. THESE CEILINGS SHOULD PERSIST THROUGH 12Z...AFTER
WHICH MODELS INDICATE THE LAYER OF LOW LEVEL MOISTURE WILL BEGIN TO
ERODE WITH WESTERLY LOW TO MID LEVEL FLOW. MODELS MAY BE ERODING
STRATUS FROM THE SOUTH AND WEST TOO QUICKLY...SO MVFR CEILINGS MAY
PERSIST UNTIL LATE MORNING AT KGSO AND KINT...AND ARE MORE LIKELY TO
PERSIST WELL INTO THE AFTERNOON FROM KRDU TO KRWI. WINDS WILL
GENERALLY BE LIGHT AND VARIABLE FOR A GOOD PORTION OF THE DAY BUT
WILL BECOME EAST-NORTHEASTERLY AGAIN THIS EVENING AS HIGH PRESSURE
OVER THE GREAT LAKES PUSHES ANOTHER COLD FRONT INTO THE AREA FROM
THE NORTH. THIS COOL STABLE FLOW WILL BRING STRATUS BACK ACROSS THE
AREA ONCE AGAIN TONIGHT AND MONDAY MORNING...POTENTIALLY WITH PATCHY
LIGHT RAIN AT TIMES. -SMITH
OUTLOOK...
THE AIR MASS WILL GRADUALLY DRY OUT ACROSS CENTRAL NC MONDAY INTO
TUESDAY AS HIGH PRESSURE AT THE SURFACE AND ALOFT SETTLES OVERHEAD.
THIS SHOULD LEAD TO SHORTER PERIODS OF MVFR CEILINGS (MAINLY
OCCURRING OVERNIGHT INTO THE MORNING HOURS). VFR CONDITIONS
ANTICIPATED FOR MOST OF WEDNESDAY AND THURSDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...SMITH
SHORT TERM...SMITH/99
LONG TERM...99
AVIATION...SMITH/WSS
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
155 AM EDT SUN APR 29 2012
.SYNOPSIS...
A STATIONARY FRONT OVER SOUTH CAROLINA WILL MOVE BRIEFLY NORTH
ALONG THE COAST AS A WARM FRONT TONIGHT BEFORE MOVING BACK SOUTH
AS A COLD FRONT ON SUNDAY AND SUNDAY NIGHT. THE FRONT SHOULD
DISSIPATE SOUTH OF THE AREA MONDAY AS HIGH PRESSURE BUILDS IN FROM
THE EAST TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1240 AM SUN...UPDATED FOR CURRENT PT CLDY SKIES OVER SRN HALF
OF AREA...AND DROPPED POPS UNTIL AFTER 2 A FOR NRN SECTIONS. ALSO
LOWERED MIN TEMPS BASEDO ON CURRENT OBS AS EVENING CLEARING ALLOWED
MORE COOLING.
/PREVIOUS DISCUSSION/
AS OF 955 PM SATURDAY...THE LOW CLOUDS HAVE DISSIPATED MUCH FASTER
AND OVER A MORE WIDESPREAD AREA THAN PREVIOUSLY EXPECTED THIS
EVENING. PERHAPS THIS IS DUE IN PART TO SUBSIDENCE SEEN IN THE OMEGA
FORECASTS AS A WEAK LOW MOVES AWAY FROM THE NC COAST. BOTH THE 00Z
GSO AND MHX SOUNDINGS WERE DEEPLY SATURATED IN THE LOW
LEVELS...EXHIBITED SHARP LOW LEVEL INVERSIONS...AND LOW LEVEL
EASTERLY FLOW...ALL SUGGESTIVE OF CONDITIONS FAVORABLE FOR LOW CLOUD
REDEVELOPMENT LATER TONIGHT. THE 18Z NAM-12 FORECAST SOUNDINGS STILL
SUPPORTED LOW CLOUDS BUT WITH SHALLOWER LOW LEVEL MOISTURE. GIVEN A
SURFACE PATTERN INDICATIVE OF HYBRID DAMMING AND THE ABOVE FACTORS I
AM STILL EXPECTING WIDESPREAD LOW CLOUDS BUT NOT WITH AS MUCH
CONFIDENCE AS BEFORE. REMNANT SHOWERS FROM AN UPSTREAM MCS COULD
AFFECT THE NORTHERN PORTION OF THE AREA LATE SO WILL MAINTAIN 20-30%
POPS NORTH FOR LATE TONIGHT.
THE STATIONARY BOUNDARY CURRENTLY LOCATED FROM NORTHEAST SOUTH
CAROLINA INTO EXTREME SOUTHEAST NORTH CAROLINA IS STILL EXPECTED
TO LIFT NORTH OVERNIGHT...MAINLY ALONG THE IMMEDIATE COAST. THIS
WILL RESULT IN THE FLOW TURNING FROM EASTERLY TO SOUTHWEST ALONG
AND NEAR THE COAST. FURTHER INLAND A HYBRID DAMMING PATTERN WILL
REMAIN AND RETARD THE NORTHWARD MOVEMENT OF THE RETREATING
BOUNDARY WITH NORTHERLY FLOW PERSISTING. STILL EXPECTING LOW
TEMPERATURES 53 TO 58 INLAND WITH TEMPERATURES BRIEFLY RISING
ALONG THE COAST SHOULD THE SW FLOW MATERIALIZE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
AS OF 245 PM SATURDAY...THE COLD FRONT WILL DRIVE TO THE SOUTH OF
THE AREA AGAIN ON SUNDAY WITH THE NAM12 AND GFS SHOWING A BROKEN
BAND OF MOISTURE AND AGAIN A SMALL POP IN THE FORECAST WITH VERY
LIGHT QPF. BUFKIT SOUNDINGS SHOW A GOOD DEAL OF MOISTURE BELOW
2000 FEET WITH THE LOW-LEVEL NORTHEAST FLOW...SO AGAIN EXPECT A
MOSTLY CLOUDY DAY ON SUNDAY WITH JUST OCCASIONAL PEAKS OF
SUNSHINE. THE BEST CHANCE OF GETTING SUNSHINE WOULD BE OVER THE
FAR SOUTHWESTERN COUNTIES WHERE SOME TEMPERATURES NEAR 80 WILL BE
POSSIBLE. OVER MUCH OF THE REMAINDER OF THE CWA...HIGHS WILL RANGE
FROM 65 TO ABOUT 72 DEGREES.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
AS OF 300 PM SAT...NE SFC FLOW WILL CONT ACROSS THE AREA THROUGH
TUE AFTN WITH LOW CLOUDS PERSISTING AREAWIDE. EXPECT LOW TO MID
50S FOR LOWS SUNDAY NIGHT WITH A 10 DEGREE TEMP RANGE ACROSS THE
CWA ON MON WITH HIGHS FROM THE MID 60S NERN AREAS TO THE MID 70S
SW. WINDS BECOME SOUTHERLY LATE IN THE AFTERNOON ON AS SFC HIGH
PRES RIDGES IN TO THE SOUTH ERODING LOW CLOUDS ALLOWING TEMPS TO
CLIMB INTO THE THE LWR 80S ACRS INLAND AREAS. MDT INSTABILITY AND
AMPLE AMS MSTR WILL BE IN PLACE FOR ISOLATED CONVECTION ACROSS
MUCH OF THE AREA.
H5 RIDGE BUILDS ACROSS ERN NC FOR THE REMAINDER OF THE WEEK WITH
DAYTIME TEMPS CLIMBING THROUGH THE 80S BY THE END OF THE WEEK AND
NIL POPS EXPECTED. MIN TEMPS WILL BE MILD WITH LOW IN THE LWR TO MID
60S.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /06Z SUNDAY THROUGH 06Z MONDAY/
AS OF 130 AM SUNDAY...MVFR CIGS REDEVELOPING OVER MOST OF AREA AND
EXPECTED TO PERSIST THROUGH MOST OF DAY WITH ANOTHER SURGE OF LOW
LVL NE WINDS AS WEAK LOW PRES MOVES OFFSHORE. SCT SHOWERS FROM
CURRENT MCS ACTIVITY OVER OH VLY MAY CLIP NRN SECTIONS AROUND 12Z
BUT MAINLY NE OF TAF SITES. WITH TYPICAL LOWERING OF CIGS
OVERNIGHT...PERIOD OF IFR LIKELY MOST SITES 09Z-13Z...THEN RAISING
BACK TO MVFR FOR MID MORNING UNTIL LATE AFTN. PERIOD OF VFR FOR LATE
AFTN INTO EVENING...THEN MVFR REDEVELOPING.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 300 PM SAT...LOW CLOUDS CONTINUE WITH N TO NE FLOW THROUGH
MON. WINDS START TO VEER TO ONSHORE MON NIGHT BECOMING SWLY TUE
AFTN ERODING THE IFR CIGS WITH MOSTLY SUNNY SKIES EXPECTED FOR TUE
AFTN WITH ISOLD CONVECTION POSSIBLE. SW FLOW CONTINUES THROUGH THE
REMAINDER OF THE WEEK WITH VFR CONDS EXPECTED.
&&
.MARINE...
SHORT TERM /THROUGH SUNDAY/...
AS OF 1240 AM SUN...LATEST NAM AND RUC HAVE DECENT HANDLE ON CURRENT
WINDS AND USED THEM FOR UPDATE. WEAK LOW MOVING OFF NRN WATERS IS
PRODUCING NW TO N WINDS 15 KT OR LESS MOST OF AREA...WITH A BRIEF
N-NE SURGE EXPECTED TO DEVELOP OVER NRN WATERS TOWARD MORNING AS LOW
MOVES NE. ALSO ADJUSTED SEAS AS HEIGHTS STILL RUNNING 4-5 FEET OVER
NRN WATERS PER WAVERIDER BUOYS.
/PREVIOUS DISCUSSION/
AS OF 955 PM SATURDAY...COMPLICATED WIND DIRECTION FORECAST BUT
FORTUNATELY WIND SPEEDS ARE FORECAST TO BE 15 KT OR LESS THROUGH
SUNDAY. A WEAK WAVE OF LOW PRESSURE ALONG THE STATIONARY FRONT WAS
LOCATED OFF OF THE OUTER BANKS. THIS LOW IS FORECAST TO MOVE WELL
OFF THE COAT OVERNIGHT AND THE GUIDANCE IS IN AGREEMENT THAT THE
FRONT WILL LIFT NORTH ALONG THE COAST WITH THE FLOW SHIFTING FROM
EASTERLY TO SOUTHWEST OVERNIGHT WHILE INLAND A HYBRID DAMMING
PATTERN REMAINS. THE FRONT IS THEN FORECAST TO DRIFT BACK SOUTH
THROUGH ALL THE WATERS DURING THE DAY ON SUNDAY WITH THE FLOW
TURNING BACK TO THE NORTH AND NORTHEAST. SEAS ARE FORECAST TO BE
IN THE 2 TO 4 FOOT RANGE. NO SMALL CRAFT ADVISORIES ARE ANTICIPATED.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 300 PM SAT...DO NOT ANTICIPATE SCA CONDITIONS IN THE LONG
TERM. NE WINDS IN THE 10 TO 15 KT RANGE AND SEAS OF 2 TO 4 FEET
WITH 5 FT SEAS FOR THE OUTER COASTAL WATERS EXPECTED THROUGH MON.
WINDS VEER TO SE MON NIGHT AND BECOME SW TUE CONTG THROUGH THE
REMAINDER OF THE WEEK WITH SEAS MAINLY IN THE 2-4 FT RANGE. MAY
SEE SOME NOCTURNAL WINDS WS AROUND 15 KT WITH SEAS 5 FT FOR THE
OUTER SRN AND CNTRL COASTAL WATERS.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CTC/JME
NEAR TERM...JBM/JME
SHORT TERM...CTC
LONG TERM...JAC
AVIATION...JBM/JAC
MARINE...JBM/JME/JAC
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1250 AM EDT SUN APR 29 2012
.SYNOPSIS...
A STATIONARY FRONT OVER SOUTH CAROLINA WILL MOVE BRIEFLY NORTH
ALONG THE COAST AS A WARM FRONT TONIGHT BEFORE MOVING BACK SOUTH
AS A COLD FRONT ON SUNDAY AND SUNDAY NIGHT. THE FRONT SHOULD
DISSIPATE SOUTH OF THE AREA MONDAY AS HIGH PRESSURE BUILDS IN FROM
THE EAST TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1240 AM SUN...UPDATED FOR CURRENT PT CLDY SKIES OVER SRN HALF
OF AREA...AND DROPPED POPS UNTIL AFTER 2 A FOR NRN SECTIONS. ALSO
LOWERED MIN TEMPS BASEDO ON CURRENT OBS AS EVENING CLEARING ALLOWED
MORE COOLING.
/PREVIOUS DISCUSSION/
AS OF 955 PM SATURDAY...THE LOW CLOUDS HAVE DISSIPATED MUCH FASTER
AND OVER A MORE WIDESPREAD AREA THAN PREVIOUSLY EXPECTED THIS
EVENING. PERHAPS THIS IS DUE IN PART TO SUBSIDENCE SEEN IN THE OMEGA
FORECASTS AS A WEAK LOW MOVES AWAY FROM THE NC COAST. BOTH THE 00Z
GSO AND MHX SOUNDINGS WERE DEEPLY SATURATED IN THE LOW
LEVELS...EXHIBITED SHARP LOW LEVEL INVERSIONS...AND LOW LEVEL
EASTERLY FLOW...ALL SUGGESTIVE OF CONDITIONS FAVORABLE FOR LOW CLOUD
REDEVELOPMENT LATER TONIGHT. THE 18Z NAM-12 FORECAST SOUNDINGS STILL
SUPPORTED LOW CLOUDS BUT WITH SHALLOWER LOW LEVEL MOISTURE. GIVEN A
SURFACE PATTERN INDICATIVE OF HYBRID DAMMING AND THE ABOVE FACTORS I
AM STILL EXPECTING WIDESPREAD LOW CLOUDS BUT NOT WITH AS MUCH
CONFIDENCE AS BEFORE. REMNANT SHOWERS FROM AN UPSTREAM MCS COULD
AFFECT THE NORTHERN PORTION OF THE AREA LATE SO WILL MAINTAIN 20-30%
POPS NORTH FOR LATE TONIGHT.
THE STATIONARY BOUNDARY CURRENTLY LOCATED FROM NORTHEAST SOUTH
CAROLINA INTO EXTREME SOUTHEAST NORTH CAROLINA IS STILL EXPECTED
TO LIFT NORTH OVERNIGHT...MAINLY ALONG THE IMMEDIATE COAST. THIS
WILL RESULT IN THE FLOW TURNING FROM EASTERLY TO SOUTHWEST ALONG
AND NEAR THE COAST. FURTHER INLAND A HYBRID DAMMING PATTERN WILL
REMAIN AND RETARD THE NORTHWARD MOVEMENT OF THE RETREATING
BOUNDARY WITH NORTHERLY FLOW PERSISTING. STILL EXPECTING LOW
TEMPERATURES 53 TO 58 INLAND WITH TEMPERATURES BRIEFLY RISING
ALONG THE COAST SHOULD THE SW FLOW MATERIALIZE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
AS OF 245 PM SATURDAY...THE COLD FRONT WILL DRIVE TO THE SOUTH OF
THE AREA AGAIN ON SUNDAY WITH THE NAM12 AND GFS SHOWING A BROKEN
BAND OF MOISTURE AND AGAIN A SMALL POP IN THE FORECAST WITH VERY
LIGHT QPF. BUFKIT SOUNDINGS SHOW A GOOD DEAL OF MOISTURE BELOW
2000 FEET WITH THE LOW-LEVEL NORTHEAST FLOW...SO AGAIN EXPECT A
MOSTLY CLOUDY DAY ON SUNDAY WITH JUST OCCASIONAL PEAKS OF
SUNSHINE. THE BEST CHANCE OF GETTING SUNSHINE WOULD BE OVER THE
FAR SOUTHWESTERN COUNTIES WHERE SOME TEMPERATURES NEAR 80 WILL BE
POSSIBLE. OVER MUCH OF THE REMAINDER OF THE CWA...HIGHS WILL RANGE
FROM 65 TO ABOUT 72 DEGREES.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
AS OF 300 PM SAT...NE SFC FLOW WILL CONT ACROSS THE AREA THROUGH
TUE AFTN WITH LOW CLOUDS PERSISTING AREAWIDE. EXPECT LOW TO MID
50S FOR LOWS SUNDAY NIGHT WITH A 10 DEGREE TEMP RANGE ACROSS THE
CWA ON MON WITH HIGHS FROM THE MID 60S NERN AREAS TO THE MID 70S
SW. WINDS BECOME SOUTHERLY LATE IN THE AFTERNOON ON AS SFC HIGH
PRES RIDGES IN TO THE SOUTH ERODING LOW CLOUDS ALLOWING TEMPS TO
CLIMB INTO THE THE LWR 80S ACRS INLAND AREAS. MDT INSTABILITY AND
AMPLE AMS MSTR WILL BE IN PLACE FOR ISOLATED CONVECTION ACROSS
MUCH OF THE AREA.
H5 RIDGE BUILDS ACROSS ERN NC FOR THE REMAINDER OF THE WEEK WITH
DAYTIME TEMPS CLIMBING THROUGH THE 80S BY THE END OF THE WEEK AND
NIL POPS EXPECTED. MIN TEMPS WILL BE MILD WITH LOW IN THE LWR TO MID
60S.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /TONIGHT AND SUNDAY/...
AS OF 715 PM SATURDAY...SOME BREAKS IN THE CLOUDS WILL OCCUR AT
THE TAF SITES THIS EVENING AND EXPECT CEILINGS TO VARY FROM VFR TO
MVFR. LATER TONIGHT WIDESPREAD MVFR CEILINGS WILL REDEVELOP AND
NOW WILL BE FORECAST TO LOWER TO IFR LEVELS BASED ON TRENDS IN THE
LATEST AVIATION GUIDANCE AND EXPECTED HYBRID DAMMING SURFACE
PATTERN INLAND. THE GFS/LAMP WERE FASTER TO INDICATE THIS LOWERING
THAN THE NAM AND WILL LEAN TOWARD THE GFS WITH IFR CONDITIONS
FORECAST TO DEVELOP 06Z-08Z. CEILINGS ARE THEN EXPECTED TO RISE TO
MVFR BY SUNDAY MORNING AND AT LEAST TEMPORARILY TO VFR MID SUNDAY
AFTERNOON BUT COULD LOWER TO MVFR OR WORSE SUNDAY EVENING AS THE
FRONT MOVES SOUTH OF THE AREA YET AGAIN.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 300 PM SAT...LOW CLOUDS CONTINUE WITH N TO NE FLOW THROUGH
MON. WINDS START TO VEER TO ONSHORE MON NIGHT BECOMING SWLY TUE
AFTN ERODING THE IFR CIGS WITH MOSTLY SUNNY SKIES EXPECTED FOR TUE
AFTN WITH ISOLD CONVECTION POSSIBLE. SW FLOW CONTINUES THROUGH THE
REMAINDER OF THE WEEK WITH VFR CONDS EXPECTED.
&&
.MARINE...
SHORT TERM /THROUGH SUNDAY/...
AS OF 1240 AM SUN...LATEST NAM AND RUC HAVE DECENT HANDLE ON CURRENT
WINDS AND USED THEM FOR UPDATE. WEAK LOW MOVING OFF NRN WATERS IS
PRODUCING NW TO N WINDS 15 KT OR LESS MOST OF AREA...WITH A BRIEF
N-NE SURGE EXPECTED TO DEVELOP OVER NRN WATERS TOWARD MORNING AS LOW
MOVES NE. ALSO ADJUSTED SEAS AS HEIGHTS STILL RUNNING 4-5 FEET OVER
NRN WATERS PER WAVERIDER BUOYS.
/PREVIOUS DISCUSSION/
AS OF 955 PM SATURDAY...COMPLICATED WIND DIRECTION FORECAST BUT
FORTUNATELY WIND SPEEDS ARE FORECAST TO BE 15 KT OR LESS THROUGH
SUNDAY. A WEAK WAVE OF LOW PRESSURE ALONG THE STATIONARY FRONT WAS
LOCATED OFF OF THE OUTER BANKS. THIS LOW IS FORECAST TO MOVE WELL
OFF THE COAT OVERNIGHT AND THE GUIDANCE IS IN AGREEMENT THAT THE
FRONT WILL LIFT NORTH ALONG THE COAST WITH THE FLOW SHIFTING FROM
EASTERLY TO SOUTHWEST OVERNIGHT WHILE INLAND A HYBRID DAMMING
PATTERN REMAINS. THE FRONT IS THEN FORECAST TO DRIFT BACK SOUTH
THROUGH ALL THE WATERS DURING THE DAY ON SUNDAY WITH THE FLOW
TURNING BACK TO THE NORTH AND NORTHEAST. SEAS ARE FORECAST TO BE
IN THE 2 TO 4 FOOT RANGE. NO SMALL CRAFT ADVISORIES ARE ANTICIPATED.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 300 PM SAT...DO NOT ANTICIPATE SCA CONDITIONS IN THE LONG
TERM. NE WINDS IN THE 10 TO 15 KT RANGE AND SEAS OF 2 TO 4 FEET
WITH 5 FT SEAS FOR THE OUTER COASTAL WATERS EXPECTED THROUGH MON.
WINDS VEER TO SE MON NIGHT AND BECOME SW TUE CONTG THROUGH THE
REMAINDER OF THE WEEK WITH SEAS MAINLY IN THE 2-4 FT RANGE. MAY
SEE SOME NOCTURNAL WINDS WS AROUND 15 KT WITH SEAS 5 FT FOR THE
OUTER SRN AND CNTRL COASTAL WATERS.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CTC/JME
NEAR TERM...JBM/JME
SHORT TERM...CTC
LONG TERM...JAC
AVIATION...JAC/CTC/JME
MARINE...JBM/JME/JAC
AREA FORECAST DISCUSSION...UPDATED
NWS CLEVELAND OH
1045 PM EDT MON APR 30 2012
.SYNOPSIS...
LOW PRESSURE IS LOCATED OVER INDIANA WITH A WARM FRONT EAST ACROSS
NORTHERN OHIO TO WESTERN PENNSYLVANIA. A COLD FRONT EXTENDED
SOUTHWEST FROM THE LOW. THE LOW WILL TRACK NORTHEAST ACROSS LAKE
ERIE THIS EVENING...EVENTUALLY DRAGGING THE COLD FRONT ACROSS THE
AREA OVERNIGHT. HIGH PRESSURE WILL BUILD IN FOR TUESDAY MORNING.
TUESDAY EVENING INTO WEDNESDAY...THE FRONT WILL SURGE BACK NORTH
ACROSS THE AREA AS A WARM FRONT.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
LOW NOW SE OF THE AREA...AND WITH IT THE THREAT OF SEVERE TSRA. UPDATED
TO REMOVE ALL REMAINING COUNTIES FROM WATCH 211.
INITIAL DISCUSSION...
LOW PRESSURE OVER INDIANA WILL MOVE ENE ACROSS LAKE ERIE THIS
EVENING. A WARM FRONT EAST OF THE LOW CURRENTLY EXTENDS ACROSS
NORTHWEST OHIO AND THE CENTRAL LAKESHORE AND THEN SOUTHEAST
THROUGH NORTHEAST OHIO INTO WESTERN PA. A COLD FRONT WILL FOLLOW
THE LOW MOVING ACROSS THE AREA OVERNIGHT. MAIN CONCERN FOR THIS
EVENING IS THE POTENTIAL FOR SEVERE WEATHER. WITH TEMPS IN THE
LOWER 80S IN THE WARM SECTOR ACROSS THE SOUTHERN TIER OF COUNTIES
AND DEWPOINTS NEAR 60...LI`S ARE NOW -2 TO -3 FROM FDY TO MFD.
EXPECT AIRMASS TO CONTINUE TO DESTABILIZE THROUGH 6 OR 7PM AND
THEN SLOWLY BEGIN TO BECOME MORE STABLE THROUGH THE EVENING.
FORECAST SOUNDINGS SHOW A GOOD MID LEVEL DRY SLOT INDICATING A
POTENTIAL FOR DOWN BURSTS AND AT LAST LOOK DOWNDRAFT CAPE HAD
REACHED 900J/KG. ALSO SURFACE BASED CAPES ARE JUST OVER 1000J/KG
ON RUC JUST TO OUR SOUTH AND WOULD EXPECT THAT AIR WILL BE LIFTED
NORTH INTO THE AREA THROUGH THE EVENING SO HAIL ALSO A POSSIBILITY.
RADAR SHOWS BAND OF RAIN FROM LOWER MI SOUTHWEST THRU NRN INDIANA
AND ILLINOIS WITH THUNDERSTORMS NOW DEVELOPING ON THE LEADING EDGE
OVER WEST CENTRAL INDIANA AND SRN ILLINOIS. EXPECT THESE TO TRACK
NORTHEAST WITH CURRENT MOTION BRINGING THUNDER FROM WESTERN
INDIANA INTO WESTERN CWA COUNTIES BETWEEN 8 AND 9PM. ...ALTHOUGH
DO EXPECT SHOWERS INTO NWRN BEFORE THEN. WILL HAVE CAT POPS FOR
THE ENTIRE AREA WITH THE POSSIBILITY OF SEVERE ACROSS ALL BUT THE
NORTHWEST CORNER. WILL CARRY THIS CHANCE OF SEVERE THROUGH THE
EVENING AND THEN TRANSITION TO SHOWERS OVERNIGHT WITH POPS ENDING
FROM THE NORTHWEST.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/...
NEED TO BE BRIEF. TUESDAY MORNING SHOULD BEGIN DRY WITH HIGH
PRESSURE BUILDING IN FROM THE NORTH. THE COLD FRONT THAT MOVES
THROUGH TONIGHT SHOULD BE AROUND THE OHIO RIVER IN TE PROCESS OF
STALLING. TUESDAY AFTERNOON THE FRONT WILL TURN WARM AND REACH THE
SWRN CWA COUNTIES. DID BRING A CHANCE POP BACK TO THE WESTERN TWO
THIRDS BY EVENING DUE TO THE FRONT. CONTINUED CHANCE POPS TUESDAY
NIGHT GIVE THE FAIRLY MOIST AIRMASS ACROSS THE AREA AND THE FRONT
CONTINUING TO MOVE THROUGH. WEDNESDAY THE AREA WILL REMAIN IN THE
WARM SECTOR. MODELS DO SHOW ENOUGH MOISTURE ACROSS THE AREA FOR
CLOUDS AND THUNDERSTORMS HOWEVER GIVEN THE BUILDING SURFACE HIGH
SHAVED POPS TO LOW TO MID CHANCE. AIRMASS DRIES A BIT WEDNESDAY
NIGHT SO WILL DROP POPS MUCH OF THE AREA. THURSDAY SURFACE HIGH
STILL JUST SOUTHEAST OF THE AREA AND UPPER RIDGING TAKING PLACE AS
WELL. STARTED TO GO COMPLETELY DRY ALTHOUGH A BIT NERVOUS AS CAPES
ARE SHOWN OVER 2000J/KG DURING THE AFTERNOON SO PUT A SLIGHT
CHANCE IN THE GRAPHICS IN CASE CONVECTION BREAKS THROUGH THE CAP.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
BIG PICTURE HAS THE UPPER RIDGE BREAKING DOWN OVER THE COURSE OF THE
WEEKEND. FOR TIMING THIS FAR OUT HAVE TURNED TO THE GFS ENS AND TAKE
A COLD FRONT THROUGH THE AREA SLOWLY FRIDAY NIGHT INTO SATURDAY.
WILL HAVE TEMPS SLIGHTLY COOLER THAN THURSDAY...BUT STILL WARM.
SCATTERED SHOWERS AND THUNDERSTORMS WITH THE FRONT. COOLER FOR THE
SECOND HALF OF THE WEEKEND...RETURNING TO NEAR NORMAL WHEN THE HIGH
REALLY PUSHES DOWN INTO THE AREA.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
LOW PRESSURE OVER N CNTRL OH WILL CONTINUE TO MOVE NE THIS
EVENING. A FRONT FROM THE LOW REMAINS ALONG THE SOUTH SHORE OF
LAKE ERIE AND HAVE BEEN SEEING SHRA/TSRA DEVELOPMENT ALONG THIS
FEATURE. WILL INCLUDE A MENTION OF T AT KCLE THE NEXT COUPLE OF
HOURS. MAIN LINE OF STORMS IS JUST NOW MOVING INTO WESTERN OH AND
WILL MOVE ACROSS THE ENTIRE AREA THIS EVENING. HAVE SEEN A GRADUAL
DECREASE IN INTENSITY WITH THESE STORMS AND WILL ONLY INCLUDE A
MENTION OF THUNDER AT KFDY AND KMFD WHERE INSTABILITY IS THE BEST.
EXPECT CIGS TO DIP TO MVFR ONCE THE STEADIER RAIN ARRIVES AND TO
IFR BEHIND THE SURFACE LOW. WILL LIKE SEE IFR CONDITIONS THE
SECOND HALF OF THE NIGHT WITH IMPROVING CONDITIONS TUESDAY
MORNING. WINDS AT KERI AND KCLE WILL BE VARIABLE THE NEXT FEW
HOURS AS THE FRONT LINGERS OVER THE AREA. ELSEWHERE SW FLOW WILL
BECOME W TO NW BEHIND THE SURFACE LOW.
.OUTLOOK...NON-VFR CONDITIONS POSSIBLE WEDNESDAY WITHIN SHOWERS
AND THUNDERSTORMS. THURSDAY NIGHT INTO FRIDAY. NON VFR AGAIN
FRIDAY INTO SATURDAY WITH SHOWERS/THUNDERSTORMS.
&&
.MARINE...
GENERALLY QUIET CONDITIONS EXPECTED ON THE LAKE THROUGH THE NEXT 5
DAYS. NOT EXPECTING WAVES GREATER THAN 2 FEET THROUGH THE PERIOD.
THIS IS ALL DUE TO THE FACT THERE WILL BE NO MAJOR WEATHER SYSTEMS
AFFECTING LAKE ERIE DURING THIS TIME PERIOD. ONLY PROBLEMS TO
CONTEND WITH IS THE THREAT FOR THUNDERSTORMS LATER THIS EVENING.
THERE WILL ALSO BE A CHANCE FOR SHOWERS AND THUNDERSTORMS AT LEAST
THROUGH FRIDAY. ONE THING TO KEEP IN MIND IS THE THREAT FOR SEVERE
THUNDERSTORMS LATER THIS EVENING ON THE LAKE. MARINERS SHOULD KEEP A
CLOSE WATCH TO THE SKY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...DJB/TK
SHORT TERM...TK
LONG TERM...OUDEMAN
AVIATION...KUBINA
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
925 PM EDT MON APR 30 2012
.SYNOPSIS...
LOW PRESSURE IS LOCATED OVER INDIANA WITH A WARM FRONT EAST ACROSS
NORTHERN OHIO TO WESTERN PENNSYLVANIA. A COLD FRONT EXTENDED
SOUTHWEST FROM THE LOW. THE LOW WILL TRACK NORTHEAST ACROSS LAKE
ERIE THIS EVENING...EVENTUALLY DRAGGING THE COLD FRONT ACROSS THE
AREA OVERNIGHT. HIGH PRESSURE WILL BUILD IN FOR TUESDAY MORNING.
TUESDAY EVENING INTO WEDNESDAY...THE FRONT WILL SURGE BACK NORTH
ACROSS THE AREA AS A WARM FRONT.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
UPDATED TO ADD OHIO COUNTIES EAST OF WATCH 211.
LOW PRESSURE OVER INDIANA WILL MOVE ENE ACROSS LAKE ERIE THIS
EVENING. A WARM FRONT EAST OF THE LOW CURRENTLY EXTENDS ACROSS
NORTHWEST OHIO AND THE CENTRAL LAKESHORE AND THEN SOUTHEAST
THROUGH NORTHEAST OHIO INTO WESTERN PA. A COLD FRONT WILL FOLLOW
THE LOW MOVING ACROSS THE AREA OVERNIGHT. MAIN CONCERN FOR THIS
EVENING IS THE POTENTIAL FOR SEVERE WEATHER. WITH TEMPS IN THE
LOWER 80S IN THE WARM SECTOR ACROSS THE SOUTHERN TIER OF COUNTIES
AND DEWPOINTS NEAR 60...LI`S ARE NOW -2 TO -3 FROM FDY TO MFD.
EXPECT AIRMASS TO CONTINUE TO DESTABILIZE THROUGH 6 OR 7PM AND
THEN SLOWLY BEGIN TO BECOME MORE STABLE THROUGH THE EVENING.
FORECAST SOUNDINGS SHOW A GOOD MID LEVEL DRY SLOT INDICATING A
POTENTIAL FOR DOWN BURSTS AND AT LAST LOOK DOWNDRAFT CAPE HAD
REACHED 900J/KG. ALSO SURFACE BASED CAPES ARE JUST OVER 1000J/KG
ON RUC JUST TO OUR SOUTH AND WOULD EXPECT THAT AIR WILL BE LIFTED
NORTH INTO THE AREA THROUGH THE EVENING SO HAIL ALSO A POSSIBILITY.
RADAR SHOWS BAND OF RAIN FROM LOWER MI SOUTHWEST THRU NRN INDIANA
AND ILLINOIS WITH THUNDERSTORMS NOW DEVELOPING ON THE LEADING EDGE
OVER WEST CENTRAL INDIANA AND SRN ILLINOIS. EXPECT THESE TO TRACK
NORTHEAST WITH CURRENT MOTION BRINGING THUNDER FROM WESTERN
INDIANA INTO WESTERN CWA COUNTIES BETWEEN 8 AND 9PM. ...ALTHOUGH
DO EXPECT SHOWERS INTO NWRN BEFORE THEN. WILL HAVE CAT POPS FOR
THE ENTIRE AREA WITH THE POSSIBILITY OF SEVERE ACROSS ALL BUT THE
NORTHWEST CORNER. WILL CARRY THIS CHANCE OF SEVERE THROUGH THE
EVENING AND THEN TRANSITION TO SHOWERS OVERNIGHT WITH POPS ENDING
FROM THE NORTHWEST.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/...
NEED TO BE BRIEF. TUESDAY MORNING SHOULD BEGIN DRY WITH HIGH
PRESSURE BUILDING IN FROM THE NORTH. THE COLD FRONT THAT MOVES
THROUGH TONIGHT SHOULD BE AROUND THE OHIO RIVER IN TE PROCESS OF
STALLING. TUESDAY AFTERNOON THE FRONT WILL TURN WARM AND REACH THE
SWRN CWA COUNTIES. DID BRING A CHANCE POP BACK TO THE WESTERN TWO
THIRDS BY EVENING DUE TO THE FRONT. CONTINUED CHANCE POPS TUESDAY
NIGHT GIVE THE FAIRLY MOIST AIRMASS ACROSS THE AREA AND THE FRONT
CONTINUING TO MOVE THROUGH. WEDNESDAY THE AREA WILL REMAIN IN THE
WARM SECTOR. MODELS DO SHOW ENOUGH MOISTURE ACROSS THE AREA FOR
CLOUDS AND THUNDERSTORMS HOWEVER GIVEN THE BUILDING SURFACE HIGH
SHAVED POPS TO LOW TO MID CHANCE. AIRMASS DRIES A BIT WEDNESDAY
NIGHT SO WILL DROP POPS MUCH OF THE AREA. THURSDAY SURFACE HIGH
STILL JUST SOUTHEAST OF THE AREA AND UPPER RIDGING TAKING PLACE AS
WELL. STARTED TO GO COMPLETELY DRY ALTHOUGH A BIT NERVOUS AS CAPES
ARE SHOWN OVER 2000J/KG DURING THE AFTERNOON SO PUT A SLIGHT
CHANCE IN THE GRAPHICS IN CASE CONVECTION BREAKS THROUGH THE CAP.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
BIG PICTURE HAS THE UPPER RIDGE BREAKING DOWN OVER THE COURSE OF THE
WEEKEND. FOR TIMING THIS FAR OUT HAVE TURNED TO THE GFS ENS AND TAKE
A COLD FRONT THROUGH THE AREA SLOWLY FRIDAY NIGHT INTO SATURDAY.
WILL HAVE TEMPS SLIGHTLY COOLER THAN THURSDAY...BUT STILL WARM.
SCATTERED SHOWERS AND THUNDERSTORMS WITH THE FRONT. COOLER FOR THE
SECOND HALF OF THE WEEKEND...RETURNING TO NEAR NORMAL WHEN THE HIGH
REALLY PUSHES DOWN INTO THE AREA.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
LOW PRESSURE OVER N CNTRL OH WILL CONTINUE TO MOVE NE THIS
EVENING. A FRONT FROM THE LOW REMAINS ALONG THE SOUTH SHORE OF
LAKE ERIE AND HAVE BEEN SEEING SHRA/TSRA DEVELOPMENT ALONG THIS
FEATURE. WILL INCLUDE A MENTION OF T AT KCLE THE NEXT COUPLE OF
HOURS. MAIN LINE OF STORMS IS JUST NOW MOVING INTO WESTERN OH AND
WILL MOVE ACROSS THE ENTIRE AREA THIS EVENING. HAVE SEEN A GRADUAL
DECREASE IN INTENSITY WITH THESE STORMS AND WILL ONLY INCLUDE A
MENTION OF THUNDER AT KFDY AND KMFD WHERE INSTABILITY IS THE BEST.
EXPECT CIGS TO DIP TO MVFR ONCE THE STEADIER RAIN ARRIVES AND TO
IFR BEHIND THE SURFACE LOW. WILL LIKE SEE IFR CONDITIONS THE
SECOND HALF OF THE NIGHT WITH IMPROVING CONDITIONS TUESDAY
MORNING. WINDS AT KERI AND KCLE WILL BE VARIABLE THE NEXT FEW
HOURS AS THE FRONT LINGERS OVER THE AREA. ELSEWHERE SW FLOW WILL
BECOME W TO NW BEHIND THE SURFACE LOW.
.OUTLOOK...NON-VFR CONDITIONS POSSIBLE WEDNESDAY WITHIN SHOWERS
AND THUNDERSTORMS. THURSDAY NIGHT INTO FRIDAY. NON VFR AGAIN
FRIDAY INTO SATURDAY WITH SHOWERS/THUNDERSTORMS.
&&
.MARINE...
GENERALLY QUIET CONDITIONS EXPECTED ON THE LAKE THROUGH THE NEXT 5
DAYS. NOT EXPECTING WAVES GREATER THAN 2 FEET THROUGH THE PERIOD.
THIS IS ALL DUE TO THE FACT THERE WILL BE NO MAJOR WEATHER SYSTEMS
AFFECTING LAKE ERIE DURING THIS TIME PERIOD. ONLY PROBLEMS TO
CONTEND WITH IS THE THREAT FOR THUNDERSTORMS LATER THIS EVENING.
THERE WILL ALSO BE A CHANCE FOR SHOWERS AND THUNDERSTORMS AT LEAST
THROUGH FRIDAY. ONE THING TO KEEP IN MIND IS THE THREAT FOR SEVERE
THUNDERSTORMS LATER THIS EVENING ON THE LAKE. MARINERS SHOULD KEEP A
CLOSE WATCH TO THE SKY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...DJB/TK
SHORT TERM...TK
LONG TERM...OUDEMAN
AVIATION...KUBINA
MARINE...LOMBARDY
AREA FORECAST DISCUSSION...UPDATED
NWS CLEVELAND OH
836 PM EDT MON APR 30 2012
.SYNOPSIS...
LOW PRESSURE IS LOCATED OVER INDIANA WITH A WARM FRONT EAST ACROSS
NORTHERN OHIO TO WESTERN PENNSYLVANIA. A COLD FRONT EXTENDED
SOUTHWEST FROM THE LOW. THE LOW WILL TRACK NORTHEAST ACROSS LAKE
ERIE THIS EVENING...EVENTUALLY DRAGGING THE COLD FRONT ACROSS THE
AREA OVERNIGHT. HIGH PRESSURE WILL BUILD IN FOR TUESDAY MORNING.
TUESDAY EVENING INTO WEDNESDAY...THE FRONT WILL SURGE BACK NORTH
ACROSS THE AREA AS A WARM FRONT.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
UPDATED TO REMOVE NWRN 5 COUNTIES FROM THE WATCH.
LOW PRESSURE OVER INDIANA WILL MOVE ENE ACROSS LAKE ERIE THIS
EVENING. A WARM FRONT EAST OF THE LOW CURRENTLY EXTENDS ACROSS
NORTHWEST OHIO AND THE CENTRAL LAKESHORE AND THEN SOUTHEAST
THROUGH NORTHEAST OHIO INTO WESTERN PA. A COLD FRONT WILL FOLLOW
THE LOW MOVING ACROSS THE AREA OVERNIGHT. MAIN CONCERN FOR THIS
EVENING IS THE POTENTIAL FOR SEVERE WEATHER. WITH TEMPS IN THE
LOWER 80S IN THE WARM SECTOR ACROSS THE SOUTHERN TIER OF COUNTIES
AND DEWPOINTS NEAR 60...LI`S ARE NOW -2 TO -3 FROM FDY TO MFD.
EXPECT AIRMASS TO CONTINUE TO DESTABILIZE THROUGH 6 OR 7PM AND
THEN SLOWLY BEGIN TO BECOME MORE STABLE THROUGH THE EVENING.
FORECAST SOUNDINGS SHOW A GOOD MID LEVEL DRY SLOT INDICATING A
POTENTIAL FOR DOWN BURSTS AND AT LAST LOOK DOWNDRAFT CAPE HAD
REACHED 900J/KG. ALSO SURFACE BASED CAPES ARE JUST OVER 1000J/KG
ON RUC JUST TO OUR SOUTH AND WOULD EXPECT THAT AIR WILL BE LIFTED
NORTH INTO THE AREA THROUGH THE EVENING SO HAIL ALSO A POSSIBILITY.
RADAR SHOWS BAND OF RAIN FROM LOWER MI SOUTHWEST THRU NRN INDIANA
AND ILLINOIS WITH THUNDERSTORMS NOW DEVELOPING ON THE LEADING EDGE
OVER WEST CENTRAL INDIANA AND SRN ILLINOIS. EXPECT THESE TO TRACK
NORTHEAST WITH CURRENT MOTION BRINGING THUNDER FROM WESTERN
INDIANA INTO WESTERN CWA COUNTIES BETWEEN 8 AND 9PM. ...ALTHOUGH
DO EXPECT SHOWERS INTO NWRN BEFORE THEN. WILL HAVE CAT POPS FOR
THE ENTIRE AREA WITH THE POSSIBILITY OF SEVERE ACROSS ALL BUT THE
NORTHWEST CORNER. WILL CARRY THIS CHANCE OF SEVERE THROUGH THE
EVENING AND THEN TRANSITION TO SHOWERS OVERNIGHT WITH POPS ENDING
FROM THE NORTHWEST.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/...
NEED TO BE BRIEF. TUESDAY MORNING SHOULD BEGIN DRY WITH HIGH
PRESSURE BUILDING IN FROM THE NORTH. THE COLD FRONT THAT MOVES
THROUGH TONIGHT SHOULD BE AROUND THE OHIO RIVER IN TE PROCESS OF
STALLING. TUESDAY AFTERNOON THE FRONT WILL TURN WARM AND REACH THE
SWRN CWA COUNTIES. DID BRING A CHANCE POP BACK TO THE WESTERN TWO
THIRDS BY EVENING DUE TO THE FRONT. CONTINUED CHANCE POPS TUESDAY
NIGHT GIVE THE FAIRLY MOIST AIRMASS ACROSS THE AREA AND THE FRONT
CONTINUING TO MOVE THROUGH. WEDNESDAY THE AREA WILL REMAIN IN THE
WARM SECTOR. MODELS DO SHOW ENOUGH MOISTURE ACROSS THE AREA FOR
CLOUDS AND THUNDERSTORMS HOWEVER GIVEN THE BUILDING SURFACE HIGH
SHAVED POPS TO LOW TO MID CHANCE. AIRMASS DRIES A BIT WEDNESDAY
NIGHT SO WILL DROP POPS MUCH OF THE AREA. THURSDAY SURFACE HIGH
STILL JUST SOUTHEAST OF THE AREA AND UPPER RIDGING TAKING PLACE AS
WELL. STARTED TO GO COMPLETELY DRY ALTHOUGH A BIT NERVOUS AS CAPES
ARE SHOWN OVER 2000J/KG DURING THE AFTERNOON SO PUT A SLIGHT
CHANCE IN THE GRAPHICS IN CASE CONVECTION BREAKS THROUGH THE CAP.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
BIG PICTURE HAS THE UPPER RIDGE BREAKING DOWN OVER THE COURSE OF THE
WEEKEND. FOR TIMING THIS FAR OUT HAVE TURNED TO THE GFS ENS AND TAKE
A COLD FRONT THROUGH THE AREA SLOWLY FRIDAY NIGHT INTO SATURDAY.
WILL HAVE TEMPS SLIGHTLY COOLER THAN THURSDAY...BUT STILL WARM.
SCATTERED SHOWERS AND THUNDERSTORMS WITH THE FRONT. COOLER FOR THE
SECOND HALF OF THE WEEKEND...RETURNING TO NEAR NORMAL WHEN THE HIGH
REALLY PUSHES DOWN INTO THE AREA.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
LOW PRESSURE OVER N CNTRL OH WILL CONTINUE TO MOVE NE THIS
EVENING. A FRONT FROM THE LOW REMAINS ALONG THE SOUTH SHORE OF
LAKE ERIE AND HAVE BEEN SEEING SHRA/TSRA DEVELOPMENT ALONG THIS
FEATURE. WILL INCLUDE A MENTION OF T AT KCLE THE NEXT COUPLE OF
HOURS. MAIN LINE OF STORMS IS JUST NOW MOVING INTO WESTERN OH AND
WILL MOVE ACROSS THE ENTIRE AREA THIS EVENING. HAVE SEEN A GRADUAL
DECREASE IN INTENSITY WITH THESE STORMS AND WILL ONLY INCLUDE A
MENTION OF THUNDER AT KFDY AND KMFD WHERE INSTABILITY IS THE BEST.
EXPECT CIGS TO DIP TO MVFR ONCE THE STEADIER RAIN ARRIVES AND TO
IFR BEHIND THE SURFACE LOW. WILL LIKE SEE IFR CONDITIONS THE
SECOND HALF OF THE NIGHT WITH IMPROVING CONDITIONS TUESDAY
MORNING. WINDS AT KERI AND KCLE WILL BE VARIABLE THE NEXT FEW
HOURS AS THE FRONT LINGERS OVER THE AREA. ELSEWHERE SW FLOW WILL
BECOME W TO NW BEHIND THE SURFACE LOW.
.OUTLOOK...NON-VFR CONDITIONS POSSIBLE WEDNESDAY WITHIN SHOWERS
AND THUNDERSTORMS. THURSDAY NIGHT INTO FRIDAY. NON VFR AGAIN
FRIDAY INTO SATURDAY WITH SHOWERS/THUNDERSTORMS.
&&
.MARINE...
GENERALLY QUIET CONDITIONS EXPECTED ON THE LAKE THROUGH THE NEXT 5
DAYS. NOT EXPECTING WAVES GREATER THAN 2 FEET THROUGH THE PERIOD.
THIS IS ALL DUE TO THE FACT THERE WILL BE NO MAJOR WEATHER SYSTEMS
AFFECTING LAKE ERIE DURING THIS TIME PERIOD. ONLY PROBLEMS TO
CONTEND WITH IS THE THREAT FOR THUNDERSTORMS LATER THIS EVENING.
THERE WILL ALSO BE A CHANCE FOR SHOWERS AND THUNDERSTORMS AT LEAST
THROUGH FRIDAY. ONE THING TO KEEP IN MIND IS THE THREAT FOR SEVERE
THUNDERSTORMS LATER THIS EVENING ON THE LAKE. MARINERS SHOULD KEEP A
CLOSE WATCH TO THE SKY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...DJB/TK
SHORT TERM...TK
LONG TERM...OUDEMAN
AVIATION...KUBINA
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
725 PM EDT MON APR 30 2012
.SYNOPSIS...
LOW PRESSURE IS LOCATED OVER INDIANA WITH A WARM FRONT EAST ACROSS
NORTHERN OHIO TO WESTERN PENNSYLVANIA. A COLD FRONT EXTENDED
SOUTHWEST FROM THE LOW. THE LOW WILL TRACK NORTHEAST ACROSS LAKE
ERIE THIS EVENING...EVENTUALLY DRAGGING THE COLD FRONT ACROSS THE
AREA OVERNIGHT. HIGH PRESSURE WILL BUILD IN FOR TUESDAY MORNING.
TUESDAY EVENING INTO WEDNESDAY...THE FRONT WILL SURGE BACK NORTH
ACROSS THE AREA AS A WARM FRONT.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
UPDATED TO ADD SEVERE THUNDERSTORM WATCH 211 VALID UNTIL 1 AM.
ENCOMPASSES WEST OF A CUYAHOGA TO STARK COUNTY LINES...MINUS LUCAS AND
OTTAWA COUNTIES. SPC WANTED TO USE THE FRONTAL BOUNDARY LINGERING
JUST SOUTH OF THE LAKESHORE AS THE NORTHERN PERIPHERY OF THE WATCH
BOX.
LOW PRESSURE OVER INDIANA WILL MOVE ENE ACROSS LAKE ERIE THIS
EVENING. A WARM FRONT EAST OF THE LOW CURRENTLY EXTENDS ACROSS
NORTHWEST OHIO AND THE CENTRAL LAKESHORE AND THEN SOUTHEAST
THROUGH NORTHEAST OHIO INTO WESTERN PA. A COLD FRONT WILL FOLLOW
THE LOW MOVING ACROSS THE AREA OVERNIGHT. MAIN CONCERN FOR THIS
EVENING IS THE POTENTIAL FOR SEVERE WEATHER. WITH TEMPS IN THE
LOWER 80S IN THE WARM SECTOR ACROSS THE SOUTHERN TIER OF COUNTIES
AND DEWPOINTS NEAR 60...LI`S ARE NOW -2 TO -3 FROM FDY TO MFD.
EXPECT AIRMASS TO CONTINUE TO DESTABILIZE THROUGH 6 OR 7PM AND
THEN SLOWLY BEGIN TO BECOME MORE STABLE THROUGH THE EVENING.
FORECAST SOUNDINGS SHOW A GOOD MID LEVEL DRY SLOT INDICATING A
POTENTIAL FOR DOWN BURSTS AND AT LAST LOOK DOWNDRAFT CAPE HAD
REACHED 900J/KG. ALSO SURFACE BASED CAPES ARE JUST OVER 1000J/KG
ON RUC JUST TO OUR SOUTH AND WOULD EXPECT THAT AIR WILL BE LIFTED
NORTH INTO THE AREA THROUGH THE EVENING SO HAIL ALSO A POSSIBILITY.
RADAR SHOWS BAND OF RAIN FROM LOWER MI SOUTHWEST THRU NRN INDIANA
AND ILLINOIS WITH THUNDERSTORMS NOW DEVELOPING ON THE LEADING EDGE
OVER WEST CENTRAL INDIANA AND SRN ILLINOIS. EXPECT THESE TO TRACK
NORTHEAST WITH CURRENT MOTION BRINGING THUNDER FROM WESTERN
INDIANA INTO WESTERN CWA COUNTIES BETWEEN 8 AND 9PM. ...ALTHOUGH
DO EXPECT SHOWERS INTO NWRN BEFORE THEN. WILL HAVE CAT POPS FOR
THE ENTIRE AREA WITH THE POSSIBILITY OF SEVERE ACROSS ALL BUT THE
NORTHWEST CORNER. WILL CARRY THIS CHANCE OF SEVERE THROUGH THE
EVENING AND THEN TRANSITION TO SHOWERS OVERNIGHT WITH POPS ENDING
FROM THE NORTHWEST.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/...
NEED TO BE BRIEF. TUESDAY MORNING SHOULD BEGIN DRY WITH HIGH
PRESSURE BUILDING IN FROM THE NORTH. THE COLD FRONT THAT MOVES
THROUGH TONIGHT SHOULD BE AROUND THE OHIO RIVER IN TE PROCESS OF
STALLING. TUESDAY AFTERNOON THE FRONT WILL TURN WARM AND REACH THE
SWRN CWA COUNTIES. DID BRING A CHANCE POP BACK TO THE WESTERN TWO
THIRDS BY EVENING DUE TO THE FRONT. CONTINUED CHANCE POPS TUESDAY
NIGHT GIVE THE FAIRLY MOIST AIRMASS ACROSS THE AREA AND THE FRONT
CONTINUING TO MOVE THROUGH. WEDNESDAY THE AREA WILL REMAIN IN THE
WARM SECTOR. MODELS DO SHOW ENOUGH MOISTURE ACROSS THE AREA FOR
CLOUDS AND THUNDERSTORMS HOWEVER GIVEN THE BUILDING SURFACE HIGH
SHAVED POPS TO LOW TO MID CHANCE. AIRMASS DRIES A BIT WEDNESDAY
NIGHT SO WILL DROP POPS MUCH OF THE AREA. THURSDAY SURFACE HIGH
STILL JUST SOUTHEAST OF THE AREA AND UPPER RIDGING TAKING PLACE AS
WELL. STARTED TO GO COMPLETELY DRY ALTHOUGH A BIT NERVOUS AS CAPES
ARE SHOWN OVER 2000J/KG DURING THE AFTERNOON SO PUT A SLIGHT
CHANCE IN THE GRAPHICS IN CASE CONVECTION BREAKS THROUGH THE CAP.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
BIG PICTURE HAS THE UPPER RIDGE BREAKING DOWN OVER THE COURSE OF THE
WEEKEND. FOR TIMING THIS FAR OUT HAVE TURNED TO THE GFS ENS AND TAKE
A COLD FRONT THROUGH THE AREA SLOWLY FRIDAY NIGHT INTO SATURDAY.
WILL HAVE TEMPS SLIGHTLY COOLER THAN THURSDAY...BUT STILL WARM.
SCATTERED SHOWERS AND THUNDERSTORMS WITH THE FRONT. COOLER FOR THE
SECOND HALF OF THE WEEKEND...RETURNING TO NEAR NORMAL WHEN THE HIGH
REALLY PUSHES DOWN INTO THE AREA.
&&
.AVIATION /23Z MONDAY THROUGH SATURDAY/...
LOW PRESSURE OVER N CNTRL OH WILL CONTINUE TO MOVE NE THIS
EVENING. A FRONT FROM THE LOW REMAINS ALONG THE SOUTH SHORE OF
LAKE ERIE AND HAVE BEEN SEEING SHRA/TSRA DEVELOPMENT ALONG THIS
FEATURE. WILL INCLUDE A MENTION OF T AT KCLE THE NEXT COUPLE OF
HOURS. MAIN LINE OF STORMS IS JUST NOW MOVING INTO WESTERN OH AND
WILL MOVE ACROSS THE ENTIRE AREA THIS EVENING. HAVE SEEN A GRADUAL
DECREASE IN INTENSITY WITH THESE STORMS AND WILL ONLY INCLUDE A
MENTION OF THUNDER AT KFDY AND KMFD WHERE INSTABILITY IS THE BEST.
EXPECT CIGS TO DIP TO MVFR ONCE THE STEADIER RAIN ARRIVES AND TO
IFR BEHIND THE SURFACE LOW. WILL LIKE SEE IFR CONDITIONS THE
SECOND HALF OF THE NIGHT WITH IMPROVING CONDITIONS TUESDAY
MORNING. WINDS AT KERI AND KCLE WILL BE VARIABLE THE NEXT FEW
HOURS AS THE FRONT LINGERS OVER THE AREA. ELSEWHERE SW FLOW WILL
BECOME W TO NW BEHIND THE SURFACE LOW.
.OUTLOOK...NON-VFR CONDITIONS POSSIBLE WEDNESDAY WITHIN SHOWERS
AND THUNDERSTORMS. THURSDAY NIGHT INTO FRIDAY. NON VFR AGAIN
FRIDAY INTO SATURDAY WITH SHOWERS/THUNDERSTORMS.
&&
.MARINE...
GENERALLY QUIET CONDITIONS EXPECTED ON THE LAKE THROUGH THE NEXT 5
DAYS. NOT EXPECTING WAVES GREATER THAN 2 FEET THROUGH THE PERIOD.
THIS IS ALL DUE TO THE FACT THERE WILL BE NO MAJOR WEATHER SYSTEMS
AFFECTING LAKE ERIE DURING THIS TIME PERIOD. ONLY PROBLEMS TO
CONTEND WITH IS THE THREAT FOR THUNDERSTORMS LATER THIS EVENING.
THERE WILL ALSO BE A CHANCE FOR SHOWERS AND THUNDERSTORMS AT LEAST
THROUGH FRIDAY. ONE THING TO KEEP IN MIND IS THE THREAT FOR SEVERE
THUNDERSTORMS LATER THIS EVENING ON THE LAKE. MARINERS SHOULD KEEP A
CLOSE WATCH TO THE SKY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...DJB/TK
SHORT TERM...TK
LONG TERM...OUDEMAN
AVIATION...KUBINA
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
349 PM EDT SUN APR 29 2012
.SYNOPSIS...
RIDGE OVER THE EASTERN LAKES WILL MOVE EAST TONIGHT. A WARM FRONT
OVER THE OHIO VALLEY WILL BEGIN TO MOVE NORTH ON MONDAY. THE FRONT
WILL MOVE BACK SOUTH AS A COLD FRONT MONDAY NIGHT AND THEN PUSH NORTH
OF THE AREA BY WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THE ISSUES TONIGHT ARE HOW QUICKLY WILL THE CLOUDS AND PRECIPITATION
GET INTO THE FORECAST AREA. THE CLOUDS WILL SLOWLY INCREASE FROM
WEST. THE AIR IS DRY...SOME THE SHOWERS MAY NOT MAKE IT INTO
NORTHWEST OHIO AS QUICKLY AS THE HRRR MODELS THINKS. WILL SLOW IT
DOWN SOME SEVERAL HOURS. A LOT OF THE GUIDANCE IS TENDING TOWARD
STABLE...SO NO THUNDER THROUGH DAYBREAK.
BECAUSE OF THE INCREASE IN CLOUDS AND SOME WIND...DO NOT EXPECT
TEMPERATURES BELOW FREEZING IN NORTHWEST PA AND PROBABLY NO
SUBSTANTIAL FROST TO SPEAK OF...MENTIONED PATCHY FROST IN OUTLYING
AREAS EAST OF MEADVILLE AND ERIE FOR A FEW HOURS.
WENT TOWARD THE WARMER GUIDANCE FOR THE LOWS...ESPECIALLY NORTHWEST
OHIO.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
ON THE EDGE ABOUT THE POPS FOR MONDAY. THE WARM FRONT WILL MOVE INTO
NORTHERN OHIO AND THEN PART OF THE AREA WILL GET INTO THE WARM
SECTOR MONDAY AFTERNOON AND THEN AS THE LOW MOVES ALONG THE FRONT
THE COLD FRONT WILL MOVE BACK SOUTH OF THE REGION FOR A TIME. WENT
MORE TOWARD THE GFS. WANTED TO GO WITH OCCASIONAL POPS FOR
MONDAY...BUT WITH SOME QUESTION ABOUT THE TIMING DIDN`T DO THAT.
IT SHOULD NOT RAIN ALL DAY...SHOULD BE SOME DRY PERIODS. ON THE
EDGE ABOUT THE RISK OF SEVERE THUNDERSTORMS...IT COULD BE CLOSE IN
THE SOUTHERN COUNTIES. THE HWO HAS SOME MENTION OF STRONG TO
SEVERE STORMS.
THE FORECAST FOR TUESDAY THROUGH WEDNESDAY NIGHT IS JUST FOR A
CHANCE OF SHOWERS AND THUNDERSTORMS WITH QUESTIONS ABOUT THE TIMING
AND THE MOISTURE.
RAINFALL SHOULD BE UNDER AN INCH WITH ISOLATED HIGHER AMOUNTS IN
THUNDERSTORMS. WITH THE GROUND SATURATED IT SHOULD NOT BE A BIG PROBLEM.
FORECAST LOWS AND HIGHS ARE TOUGH...USED A BLEND OF
GUIDANCE. TENDED TOWARD THE WARMER GUIDANCE...MONDAY IS REALLY
TOUGH WITH THE THREAT OF SHOWERS AND THUNDERSTORMS JUST ABOUT
ANYTIME.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
LONG TERM PORTION BEGINS ON FRIDAY WITH MODELS IN GENERAL AGREEMENT
SHOWING ZONAL FLOW ACROSS THE UPPER MIDWEST AND GREAT LAKES REGION.
AT THE SURFACE...HIGH PRESSURE WILL BE ACROSS THE SOUTHEASTERN
STATES WITH A COLD FRONT NE TO SW ACROSS THE GREAT LAKES. MODELS
SHOW ENOUGH MOISTURE FOR CLOUDS AND PRECIP HOWEVER THE REGION WILL
BE IN THE WARM SECTOR SO WILL PUT ENOUGH FOR PARTLY CLOUDY/PARTLY
SUNNY AND EXPECT JUST SCATTERED/CHANCE POPS. SATURDAY SHOULD START
OUT MUCH THE SAME ALTHOUGH THE COLD FRONT SHOULD TRACK SOUTH ACROSS
THE AREA DURING THE EVENING OR OVERNIGHT SATURDAY NIGHT BUT LIMITED
MOISTURE BY THAT TIME ON THE ECMWF SO WILL GO WITH A DRY PASSAGE FOR
NOW. SUNDAY WILL REMAIN DRY AS UPPER HIGH BUILDS IN FROM THE WEST.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
HIGH PRESSURE AND VERY DRY AIR IN PLACE ACROSS THE AREA TODAY.
WARM FRONT TO THE SOUTHWEST WILL APPROACH THE AREA FROM THE
SOUTHWEST OVERNIGHT. OVERRUNNING MOISTURE WILL MOVE IN MAINLY
OVERNIGHT WITH LOWERING CEILINGS EXPECT LIGHT RAIN TO MOVE INTO
THE TOL-FDY-MFD AREAS FROM 08-09Z AND CLE AROUND 12Z. CONDITIONS
WILL LIKELY DROP TO MVFR IN THE RAIN. MODELS ALSO SHOWING
INSTABILITY MOVING IN SO COULD HAVE THUNDERSTORMS IN THE AREA
MONDAY AFTERNOON. WILL HAVE VCTS IN CLE FOR THE
AFTERNOON...OTHERWISE WILL NOT HAVE THUNDER IN THE FORECAST THIS
PACKAGE.
.OUTLOOK...NON-VFR CONDITIONS POSSIBLE ALONG A WARM FRONT MONDAY
NIGHT THROUGH TUESDAY NIGHT.
&&
.MARINE...
HIGH PRESSURE OVER THE LAKES WILL MOVE EAST OVERNIGHT AND ALLOW WEAK
LOW PRESSURE TO MOVE THROUGH THE OHIO VALLEY MONDAY AND ACROSS LAKE
ERIE MONDAY NIGHT. THIS WILL BRING A WARM FRONT ONTO THE LAKE
MONDAY NIGHT...FOLLOWED QUICKLY BY A COLD FRONT. TUESDAY HIGH
PRESSURE WILL BUILD ACROSS THE LAKE. WEDNESDAY THE HIGH WILL MOVE
EAST AND WITH LOW PRESSURE ACROSS THE CENTRAL AND NORTHERN PLAINS A
SOUTHERLY GRADIENT OF MILD AIR WILL MOVE ACROSS THE LAKE AND
CONTINUE THROUGH THE FRIDAY. WINDS WILL REMAIN GENERALLY LIGHT AT
15 KNOTS OR LESS MOST OF THE TIME. WAVES WILL REMAIN BELOW 4 FEET SO
EXPECT NO HEADLINES NEXT SEVERAL DAYS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...TK
AVIATION...TK
MARINE...TK
AREA FORECAST DISCUSSION
NWS TULSA OK
1206 AM CDT SUN APR 29 2012
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
SCATTERED CONVECTION HAS DEVELOPED OVER WESTERN AND CENTRAL
OKLAHOMA TONIGHT ALONG AND NORTH OF A FRONTAL BOUNDARY POSITIONED
OVER THE REGION. THIS CONVECTION WILL HAVE THE GREATEST CHANCES OF
AFFECTING NORTHEAST OKLAHOMA TAF SITES. FRONTAL BOUNDARY IS
EXPECTED TO RETREAT NORTHWARD LATE OVERNIGHT AND SUNDAY...WHICH
WILL SHIFT WINDS OUT OF THE SOUTH AT ALL SITES. VFR CONDITIONS
WILL CONTINUE FOR NORTHEAST OKLAHOMA...WITH MVFR CONDITIONS WITHIN
ANY CONVECTIVE DEVELOP AND THEN RETURNING BACK TO VFR CONDITIONS
SUNDAY AFTERNOON/EVENING. FOR SOUTHEAST OKLAHOMA AND NORTHWEST
ARKANSAS...WILL LEAVE VFR CONDITIONS IN THE TAF...THOUGH SOME
EARLY MORNING MVFR CEILINGS COULD BE POSSIBLE.
&&
.PREV DISCUSSION... /ISSUED 727 PM CDT SAT APR 28 2012/
DISCUSSION...
LONG RANGE RADAR ECHOES FROM KINX ARE SHOWING HINTS THAT CONVECTION
IS TRYING TO DEVELOP TO THE SW OF OKC. MODEL SOUNDINGS SHOW THE
CAP WEAKENING AROUND AND AFTER 00Z...AND THIS WILL ALLOW FOR MORE
STORM DEVELOPMENT ALONG AND NORTH OF THE FRONT. THE LLJ IS
FORECAST TO STRENGTHEN TO THE SOUTH OF THE FRONT DURING THE
OVERNIGHT...ESPECIALLY OVER SW AND CNTRL OK. AS A RESULT...A
GRADUAL EXPANSION IN CONVECTIVE COVERAGE IS EXPECTED ACROSS N
CNTRL OK LATER THIS EVENING...WITH THIS ACTIVITY SPREADING
GENERALLY E/NE INTO NORTHEAST OK AROUND OR AFTER MIDNIGHT PER THE
MOST RECENT RUNS OF THE HRRR. THE ECMWF AND GFS ENSEMBLE DATA ALSO
SUPPORT THIS AS WELL. I HAVE RAISED POPS BASICALLY FROM THE I-44
CORRIDOR NORTHWARD INTO THE LIKELY CATEGORY. THE HRRR DOES ALSO
HINT THAT ONE OR TWO STORMS COULD REMAIN DISCRETE ON THE SOUTHERN
FRINGE OF THE CONVECTIVE CLUSTER...AND ANY POTENTIAL RIGHT MOVING
SUPERCELL WOULD MOVE MORE EAST THAN NORTH...AND COULD POTENTIALLY
AFFECT THE TULSA METRO AND SURROUNDING AREAS LATER. ANY RIGHT
MOVING SUPERCELL WOULD HAVE AT LEAST LIMITED TORNADO POTENTIAL
GIVEN THE STRENGTHENING 0-1KM SHEAR AND LOW LCLS TONIGHT. UPDATED
TEXT PRODUCTS OUT SHORTLY.
LACY
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 65 78 65 80 / 60 50 70 50
FSM 65 84 64 81 / 20 20 30 50
MLC 64 79 66 80 / 20 20 30 30
BVO 61 77 63 79 / 70 60 70 50
FYV 60 80 61 77 / 40 20 40 60
BYV 62 80 61 77 / 30 30 40 60
MKO 63 80 64 79 / 40 30 50 40
MIO 64 79 64 80 / 60 50 70 50
F10 64 78 66 79 / 40 30 50 30
HHW 63 81 65 81 / 10 10 20 20
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...20
AREA FORECAST DISCUSSION
NWS MEDFORD OR
915 PM PDT SAT APR 28 2012
.UPDATE...
UPDATES WERE MADE TO THE WIND FORECAST OVER THE COASTAL WATERS FOR
THIS EVENING THROUGH TOMORROW BECAUSE OBSERVED WINDS HAVE
INCREASED ABOVE MODEL GUIDANCE ACROSS THE SOUTHERN WATERS. USED
THE RTMA AND THE RUC SHORT TERM MODELS CALIBRATED OFF OF OBSERVED
VALUES AT BUOY 27 TO UPDATE THE WIND FORECAST. SINCE AN UPDATE WAS
NEEDED FOR THE WINDS ALSO MADE SOME VERY MINOR ADJUSTMENTS TO THE
SKY COVER FOR TOMORROW MORNING TO DECREASE IT SLIGHTLY FROM ABOUT
TALENT SOUTHEASTWARD TO THE TULELAKE BASIN AND SHASTA VALLEY
AREAS. THE NET AFFECT WAS ONLY TO ADJUST THE SKY BY ONE CATEGORY.
BTL
&&
.DISCUSSION...
HIGH PRESSURE BUILDING OFFSHORE AND INDUCED LEE SIDE LOW PRESSURE
DEEPENING OVER CALIFORNIA HAS LED TO RAPIDLY INCREASING NORTH WINDS
IN THE SOUTHERN COASTAL WATERS THIS EVENING. THIS IS THE FIRST NORTH
WIND EVENT IN AWHILE IN THE WATERS AND SHOULD RESULT IN SOME
BENEFICIAL UPWELLING ALONG AND THE NEAR THE COAST. NORTH WINDS WILL
REMAIN MODERATE AND GUSTY IN THE SOUTHERN WATERS INTO SUNDAY
AFTERNOON, DIMINISHING IN THE EVENING AS THE OFFSHORE HIGH GETS
BUMPED INLAND BY AN APPROACHING LOW PRESSURE SYSTEM OFFSHORE.
CLOUDS ON THE WEST SIDE TONIGHT THROUGH SUNDAY MORNING WILL SERVE
TO KEEP TEMPERATURES UP TONIGHT, GIVING WARMING A HEAD START FOR
SUNDAY AFTERNOON. EXPECT TEMPERATURES TO BE 3 TO 8 DEGREES ABOVE
NORMAL FOR HIGHS SUNDAY AFTERNOON WITH PLENTY OF 60S AND 70S AND
EVEN A FEW 80S ACROSS THE AREA.
A FRONTAL SYSTEM WILL PUSH GENERALLY LIGHT PRECIPITATION ACROSS
THE MOUNTAINS AND WEST SIDE MONDAY INTO TUESDAY, WITH THE GREATEST
AMOUNTS ALONG THE COAST AND IN THE UMPQUA BASIN. TEMPERATURES WILL
BE KNOCKED DOWN TO NEAR NORMAL VALUES MONDAY THROUGH WEDNESDAY FROM
THIS FRONTAL SYSTEM.
MODELS HAVE TRENDED TOWARD A SOMEWHAT STRONGER FRONTAL SYSTEM FOR
LATER WEDNESDAY THROUGH NEXT FRIDAY. THUS, ANOTHER ROUND OF
PRECIPITATION SHOULD BE EXPECTED FOR LATE NEXT WEEK,GREATEST OVER
NORTHWEST SECTIONS AND LEAST OVER SOUTHEAST SECTIONS. BTL
&&
.AVIATION...
THIS EVENING...OVER COASTAL LOCATIONS...EXPECT MVFR CIGS TO
BECOME WIDESPREAD AS MARINE STRATUS MOVES INTO THE COAST. VFR WILL
CONTINUE INLAND THIS EVENING...THEN THE MARINE LAYER IS EXPECTED
TO PUSH INLAND TONIGHT WITH MVFR CEILINGS LIKELY TONIGHT AND
SUNDAY MORNING FROM THE COAST TO THE UMPQUA BASIN AND ROGUE
VALLEY. ALONG THE COAST AND INLAND...MVFR CIGS ARE EXPECTED TO
CLEAR TO VFR AROUND 15-17Z SUNDAY MORNING WITH LINGERING AREAS OF
MVFR IN THE UMPQUA THROUGH THE LATE MORNING. EAST SIDE LOCATIONS
SHOULD REMAIN VFR TONIGHT AND SUNDAY MORNING.
&&
.PREV DISCUSSION... /ISSUED 219 PM PDT SAT APR 28 2012/
DISCUSSION...UPPER LEVEL RIDGE NUDGES INTO THE REGION FROM
OFFSHORE THIS EVENING WITH SUBSIDENCE DRYING OUT THE ATMOSPHERE
ABOVE 700 MB. LIGHT AND LOW TOPPED SHOWERS WILL DIMINISH QUICKLY
AFTER SURFACE HEATING IS LOST WITH MOIST ONSHORE FLOW CONTINUING
TO BRING LIGHT PRECIP MOSTLY IN THE FORM OF DRIZZLE TO THE COAST
NORTH OF CAPE BLANCO. A BREAK IN THE ACTION COMES SUNDAY AHEAD OF
THE NEXT SYSTEM THAT MOVES IN MONDAY MORNING AFTER THE UPPER RIDGE
PATTERN FLATTENS AND TRANSFORMS INTO A NORTHWEST ZONAL FLOW
PATTERN. THE NOSE OF THE +120KT JET IS POINTED DIRECTLY AT
PORTLAND MONDAY MORNING WITH THE BEST JET DYNAMICS NORTH OF OUR
REGION...BRINGING THE HIGHEST PRECIPITATION AMOUNTS NORTH OF THE
REGION. THIS JET SPLITS WITH THE NORTH BRANCH WEAKENING AND THE
SOUTHERLY SPLIT STRENGTHENING WITH THE NOSE POINTING INTO NORTHERN
CALIFORNIA BY TUESDAY MORNING. HOWEVER...FLOW BECOMES A MORE
STABLE WESTERLY FLOW UP THROUGH 700 MB DURING THE BEST DYNAMICS.
COOLER AIR MOVING IN ALOFT KEEPS SHOWERS WEST OF THE CASCADES AND
IN THE CASCADES. 700 MB WINDS FROM THE WEST AT AROUND 35 KT IN
THE LEFT EXIT REGION IN THE COOLER AIR POOL ALOFT MONDAY NIGHT
CONTINUES SHOWERS THROUGH MOST OF THE NIGHT.
LONG TERM...WEDNESDAY THROUGH SATURDAY...MODELS ARE IN GOOD
AGREEMENT SHOWING A LOW PRESSURE SYSTEM APPROACHING THE COAST
WEDNESDAY EVENING WITH A FRONT PUSHING INLAND WEDNESDAY NIGHT AND
THURSDAY. THERE ARE SLIGHT DIFFERENCES IN THE HANDLING OF THIS LOW.
OVERALL MODELS AGREE THIS SYSTEM WILL LIKELY BRING RAIN INTO AREAS
FROM THE CASCADES WEST WEDNESDAY AFTERNOON AND EVENING AS THE WARM
FRONT PUSHES INLAND...THEN ADDITIONAL RAIN WEDNESDAY NIGHT AND
THURSDAY AS THE COLD FRONT PUSHES INLAND. THE ECMWF HAS A SLIGHTLY
MORE SOUTHERLY TRACK WITH THE LOW AND IS A WETTER DURING THIS
PERIOD. ALSO EXPECT GUSTY SOUTHWESTERLY WINDS ON THURSDAY AHEAD OF
THE COLD FRONT...ESPECIALLY OVER HIGHER TERRAIN AND FOR LOCATIONS
EAST OF THE CASCADES. THURSDAY NIGHT SHOWERS PERSIST ESPECIALLY OVER
WESTERN PORTIONS OF THE AREA...THEN TAPER OFF ON FRIDAY AS THE
SYSTEM LIFTS NORTHEAST. BY SATURDAY...THE MODEL DIFFERENCES
INCREASE. THE GFS SHOWS A WESTERLY FLOW BUT DRY PATTERN WHILE THE
ECMWF BRINGS A DEEPENING UPPER LOW INTO NORTHERLY CALIFORNIA WITH
SHOWERS POSSIBLE. HAVE KEPT IN A SLIGHT CHANCE FOR PRECIPITATION ON
SATURDAY GIVEN THE UNCERTAINTY.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 8 PM PDT SUNDAY FOR
PZZ356.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 PM PDT SUNDAY
FOR PZZ356-376.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 8 PM PDT SUNDAY FOR
PZZ376.
$$
BTL/SVEN/CC
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1031 PM EDT MON APR 30 2012
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL STRENGTHEN AND CONTROL THE WEATHER
THROUGH THE WEEK. SMALL AREAS OF UPPER LEVEL ENERGY WILL PROVIDE
SOME SHOWERS AND STORMS OVER THE MOUNTAINS AND MORE ISOLATED
ACTIVITY IN THE FOOTHILLS AND PIEDMONT LATE IN THE DAY. A COLD
FRONT IS EXPECTED TO MOVE FROM NORTH TO SOUTH INTO THE AREA NEXT
WEEKEND.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 1030 PM EDT...THE SPC MESOANALYSIS PAGE IS STILL SHOWING
MUCAPES OF 2000-3000 J/KG OVER A GOOD BIT OF THE FA. SURFACE BASED
PARCELS WILL HAVE TROUBLE LIFTING AS THE CIN IS INCREASING.
HOWEVER...AN INCREASING LLVL JET AND A VERY MOIST AIRMASS IS
RESULTING IN ELEVATED CONVECTION NOW STARTING TO DEVELOP OVER THE
UPSTATE AND NE GA. WITH STEEP LAPSE RATES FROM H7-H5...THESE
ELEVATED UPDRAFTS ARE QUITE VIGOROUS AND WILL LIKELY CONTINUE TO
PRODUCE HAIL. THE SAME PROCESS...ALBEIT WITH THE FORCING COMING FROM
OROGRAPHIC LIFT...HAS TRIGGERED STRONG TO SEVERE STORMS MUCH OF THE
EVENING OVER THE CENTRAL AND NRN MTNS AND WESTERN FOOTHILLS. IT
APPEARS THAT THE LLVL JET WILL TAKE OVER AS THE PRIMARY FORCING
MECHANISM...AND CONVECTIVE CONVERGE SHOULD CONTINUE TO DECREASE
ACROSS THE MTNS. BUT...OUT ACROSS THE FOOTHILLS AND PIEDMONT OF
CAROLINAS AND NE GA THIS PROCESS IS LIKELY TO RESULT IN AN INCREASE
IN COVERAGE OVER THE NEXT COUPLE HOURS. A WEAK H5 SHORT WAVE
ANALYZED BY THE RUC OVER THE SRN APPALACHIANS WILL ALSO HELP THIS
PROCESS ALONG. THIS ISN/T THE PLAINS...AND THE LLVL JET ISN/T THAT
STRONG...SO I THINK BY 0500 UTC MOST OF THE CONVECTION SHOULD START
TO WIND DOWN. STILL...POPS HAVE BEEN RAISED TO LOW END LIKELY ALONG
THE I-85 CORRIDOR OF THE UPSTATE AND EXTREME SRN NC FOR THE NEXT
COUPLE HOURS.
AS OF 805 PM EDT...GRIDS ARE IN GOOD SHAPE. STRONG TO SEVERE STORMS
HAVE REMAINED CONFINED TO THE CENTRAL AND NRN NC MTNS AND THE NW
FOOTHILLS...EXACTLY AS WAS IN THE FORECAST.
PREVIOUS DISCUSSION...
AS OF 200 PM... 12Z NAM...LOCAL WRF AND THE 12Z GFS INDICATE THAT
CONVECTIVE INITIATION WILL OCCUR OVER THE NORTHERN MOUNTAINS IN THE
19Z-21Z TIMEFRAME...WITH CONVECTION THEN MOVING EAST THROUGH THE NC
FOOTHILLS INTO THE NORTHERN PIEDMONT. ADDITIONAL DEVELOPMENT THEN IS
FORECAST ESSENTIALLY THROUGH THE LEE TROUGH AROUND 00Z WITH STORMS
ACROSS THE NORTHERN UPSTATE INTO NE GA. CONVECTIVE ACTIVITY SHOULD
THEN WANE BY 06Z OR SO. CURRENT POP FIELD LOOKS GOOD IN REGARD TO
THIS SCENARIO.
SBCAPES ALREADY HAVE INCREASED INTO THE 1500-2000J/KG RANGE.
HOWEVER...IT LOOKS LIKE THERE IS SUFFICIENT CIN TO CAP CONVECTIVE
INITIATION UNTIL ABOUT 20Z IN THE NORTHERN MOUNTAINS. WITH BULK
SHEAR AROUND 30KT...THIS MY BE ENOUGH TO SUSTAIN UPDRAFTS AND ALLOW
CONVECTION TO SPREAD OUT OVER THE FOOTHILLS. ALSO...DCAPE OVER THE
MOUNTAINS IS AROUND 1000J...SO A FEW SEVERE STORMS ARE POSSIBLE WITH
LARGE HAIL AND DAMAGING WINDS.
ALL INDICATIONS ARE THAT THE STORMS WILL DISSIPATE BY 06Z...SO
IT SHOULD BE QUIET LATE TONIGHT WITH JUST DOME DEBRIS CLOUDINESS AND
PATCHY FOG. SOME STRATUS MAY MAKE A RUN AT THE EASTERN AND SOUTHERN
PERIPHERY OF THE CWA AROUND SUNRISE.
ON TUE...EXPECT A FEW SHOWERS TO BEGIN CROPPING UP IN THE MOUNTAINS
TUE MORNING WITH UPSLOPE FLOW AND AN APPROACHING VORT. SCATTERED
SHOWERS AND STORMS ARE THEN EXPECTED TO DEVELOP ACROSS THE NC
FOOTHILLS/PIEDMONT AS A WEAK FRONTAL BOUNDARY DROPS INTO THE AREA
DURING THE AFTERNOON. A FEW STORMS COULD MOVE OUT INTO NE GA AND THE
SC FOOTHILLS/PIEDMONT LATE IN THE DAY. CONDITIONAL INSTABILITY WILL
ONCE AGAIN BE ON THE ORDER OF 1500J/KG SO CAN`T RULE OUT A FEW
SEVERE STORMS OVER WESTERN NC WHERE WIND SHEAR IS THE GREATEST.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 140 PM MONDAY...SHORT RANGE MODELS INDICATE THAT THE CENTER OF
H5 RIDGE WILL BUILD OVER THE SAVANNAH RIVER BASIN WEDNESDAY AND
THURSDAY. SKY COVER WILL REMAIN LIMITED TO PARTLY CLOUDY CONDITIONS
THROUGH THE PERIOD...ESPECIALLY OVER THE MTNS AND ADJACENT
FOOTHILLS. THE RIDGE WILL SUPPLY THE REGION WITH VERY WARM LLVL
THICKNESSES AND H85 TEMPS BETWEEN 16C TO 18C. USING A BLEND OF MOS
GUIDANCE...FORECAST LOW TEMPS ARE FORECAST TO RANGE FROM THE L50S
ACROSS THE MTN VALLEYS TO L60S EAST...OR AROUND 10 DEGREES ABOVE
NORMAL. THIS WILL SET THE STAGE FOR RECORD TO NEAR RECORD HIGH
TEMPERATURES EACH DAY. HERE ARE THE RECORDS FOR WEDNESDAY AND
THURSDAY FOR KGSP...KCLT...AND KAVL:
KGSP
MAY 2ND 90F IN 1959 FORECAST 90F
MAY 3RD 91F IN 1959 FORECAST 90F
KCLT
MAY 2ND 91F IN 1959 FORECAST 88F
MAY 3RD 94F IN 1902 FORECAST 91F
KAVL
MAY 2ND 88F IN 1935 FORECAST 85F
MAY 3RD 85F IN 1965 FORECAST 86F
WEDNESDAY AND THURSDAY...THE ENVIRONMENT WILL CHANGE LITTLE FROM DAY
TO DAY. FORECAST SOUNDINGS FEATURE A WEAK INVERSION AROUND H8 WITH
CIN VALUES RANGING BETWEEN 30 TO 60 J/KG. WIND FIELDS SHOULD RESULT
IN ONLY WEAK SHEAR...ESPECIALLY ON THURSDAY. THE STORM MODE SHOULD
REMAIN AS PULSE STORMS. GIVEN THE LINGERING INVERSION...LACK OF A
TRIGGER...AND SLOW STORM MOTIONS WILL FAVOR SCHC POPS EAST OF THE
MTNS...WITH CHC POPS ACROSS THE RIDGES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 145 PM MONDAY...THE MEDIUM RANGE MODELS HAVE BEEN RATHER
CHANGEABLE. MOST RECENT HPC WORD SAYS BLENDING ECMWF AND GEFS
ENSEMBLES ARE THE BEST WAY TO GO. WHEN COMPARING THE OPERATIONAL
GFS AND ECMWF START THE MEDIUM RANGE IN A MODERATE 500MB RIDGE
THURSDAY NIGHT. BOTH SHOW THURSDAY EVENING CONVECTION FROM THE
VIRGINIAS TO EASTERN NC. THIS TREND DIMINISHES FOR LATE FRIDAY AS
THE RIDGE FLATTENS. GOING INTO THE WEEKEND...THESE TWO MODELS
DIVERGE IN SOLUTIONS. THE RIDGE REBUILDS OVER THE SE ON THE ECMWF
FOR SATURDAY WHILE RIDGE RETROGRADES TO TEXAS ON THE GFS WITH TROF
FORMING OVER EAST. THE LATEST 12Z GFS BRINGS THE COLD FRONT ACROSS
OUR AREA EARLY SUNDAY WHILE THE PREVIOUS RUN WAITED UNTIL LATE
MONDAY. THE MOST RECENT ECMWF HAD A WEAK FRONT CROSSING OUR REGION
MONDAY NIGHT. OF COURSE...WITH THIS BEING A WEEK AWAY WE WILL HAVE
SLIGHT POPS IN FORECAST THROUGH THE GENERAL TIME UNTIL WE CAN NAIL
DOWN A MORE DEFINITE TIME FOR FRONTAL PASSAGE.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
AT KCLT...INTENSE TSTMS SHOULD REMAIN CONFINED TO THE NC MTNS AND
WRN FOOTHILLS THIS EVENING. WINDS WILL GENERALLY BE OUT OF THE
SOUTH. STRATUS IS EXPECTED TO DEVELOP OVER THE MIDLANDS AND INTO
CENTRAL NC LATE TONIGHT. THE BACK EDGE OF THE LOW CLOUDS WILL BE
QUITE CLOSE TO THE AIRFIELD. I/VE PUT FEW006 IN THE TAF FOR A FEW
HOURS AROUND SUNRISE. THE RUC BUFKIT REALLY IMPLIES THE LOW CIGS
WILL MAKE IT...BUT THE NAM IS MORE IFFY. TMRW AFTN A FEW TSTMS MAY
APPROACH THE AIRFIELD FROM THE NW LATE IN THE DAY.
ELSEWHERE...STRATUS IS EXPECTED TO DEVELOP EAST OF THE REGION
OVERNIGHT...BUT SHOULD STAY SEVERAL MILES EAST OF ALL THE UPSTATE
TAF SITES. MID LEVEL CLOUDS SHOULD KEEP SKIES CLOUDY ENOUGH TO
PREVENT WIDESPREAD VALLEY FOG IN THE NC MTNS. A STRENGTHENING LLVL
JET SHOULD KEEP THE WINDS UP ENUF IN THE FOOTHILLS AND PIEDMONT TO
PREVENT ANYTHING BUT PATCHY MVFR FOG AS WELL. WINDS WILL GENERALLY
BE OUT OF SOUTH TONIGHT...VEERING TO SW ON TUESDAY. SCT TSTMS WILL
DEVELOP OVER THE MTNS TUE...BUT COVERAGE IS NOT GREAT ENUF TO
INCLUDE IN THE TAF.
OUTLOOK...SCT TSTMS WILL DEVELOP OVER THE MTNS WED-FRI. A MOST
AIRMASS WILL ALLOW AREAS OF FOG AND STRATUS TO FORM IN SPOTS THROUGH
THE END OF THE WEEK AS WELL.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...MCAVOY
SHORT TERM...NED
LONG TERM...DEO
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
813 PM EDT MON APR 30 2012
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL STRENGTHEN AND CONTROL THE WEATHER
THROUGH THE WEEK. SMALL AREAS OF UPPER LEVEL ENERGY WILL PROVIDE
SOME SHOWERS AND STORMS OVER THE MOUNTAINS AND MORE ISOLATED
ACTIVITY IN THE FOOTHILLS AND PIEDMONT LATE IN THE DAY. A COLD
FRONT IS EXPECTED TO MOVE FROM NORTH TO SOUTH INTO THE AREA NEXT
WEEKEND.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 805 PM EDT...GRIDS ARE IN GOOD SHAPE. STRONG TO SEVERE STORMS
HAVE REMAINED CONFINED TO THE CENTRAL AND NRN NC MTNS AND THE NW
FOOTHILLS...EXACTLY AS WAS IN THE FORECAST.
PREVIOUS DISCUSSION...
AS OF 200 PM... 12Z NAM...LOCAL WRF AND THE 12Z GFS INDICATE THAT
CONVECTIVE INITIATION WILL OCCUR OVER THE NORTHERN MOUNTAINS IN THE
19Z-21Z TIMEFRAME...WITH CONVECTION THEN MOVING EAST THROUGH THE NC
FOOTHILLS INTO THE NORTHERN PIEDMONT. ADDITIONAL DEVELOPMENT THEN IS
FORECAST ESSENTIALLY THROUGH THE LEE TROUGH AROUND 00Z WITH STORMS
ACROSS THE NORTHERN UPSTATE INTO NE GA. CONVECTIVE ACTIVITY SHOULD
THEN WANE BY 06Z OR SO. CURRENT POP FIELD LOOKS GOOD IN REGARD TO
THIS SCENARIO.
SBCAPES ALREADY HAVE INCREASED INTO THE 1500-2000J/KG RANGE.
HOWEVER...IT LOOKS LIKE THERE IS SUFFICIENT CIN TO CAP CONVECTIVE
INITIATION UNTIL ABOUT 20Z IN THE NORTHERN MOUNTAINS. WITH BULK
SHEAR AROUND 30KT...THIS MY BE ENOUGH TO SUSTAIN UPDRAFTS AND ALLOW
CONVECTION TO SPREAD OUT OVER THE FOOTHILLS. ALSO...DCAPE OVER THE
MOUNTAINS IS AROUND 1000J...SO A FEW SEVERE STORMS ARE POSSIBLE WITH
LARGE HAIL AND DAMAGING WINDS.
ALL INDICATIONS ARE THAT THE STORMS WILL DISSIPATE BY 06Z...SO
IT SHOULD BE QUIET LATE TONIGHT WITH JUST DOME DEBRIS CLOUDINESS AND
PATCHY FOG. SOME STRATUS MAY MAKE A RUN AT THE EASTERN AND SOUTHERN
PERIPHERY OF THE CWA AROUND SUNRISE.
ON TUE...EXPECT A FEW SHOWERS TO BEGIN CROPPING UP IN THE MOUNTAINS
TUE MORNING WITH UPSLOPE FLOW AND AN APPROACHING VORT. SCATTERED
SHOWERS AND STORMS ARE THEN EXPECTED TO DEVELOP ACROSS THE NC
FOOTHILLS/PIEDMONT AS A WEAK FRONTAL BOUNDARY DROPS INTO THE AREA
DURING THE AFTERNOON. A FEW STORMS COULD MOVE OUT INTO NE GA AND THE
SC FOOTHILLS/PIEDMONT LATE IN THE DAY. CONDITIONAL INSTABILITY WILL
ONCE AGAIN BE ON THE ORDER OF 1500J/KG SO CAN`T RULE OUT A FEW
SEVERE STORMS OVER WESTERN NC WHERE WIND SHEAR IS THE GREATEST.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 140 PM MONDAY...SHORT RANGE MODELS INDICATE THAT THE CENTER OF
H5 RIDGE WILL BUILD OVER THE SAVANNAH RIVER BASIN WEDNESDAY AND
THURSDAY. SKY COVER WILL REMAIN LIMITED TO PARTLY CLOUDY CONDITIONS
THROUGH THE PERIOD...ESPECIALLY OVER THE MTNS AND ADJACENT
FOOTHILLS. THE RIDGE WILL SUPPLY THE REGION WITH VERY WARM LLVL
THICKNESSES AND H85 TEMPS BETWEEN 16C TO 18C. USING A BLEND OF MOS
GUIDANCE...FORECAST LOW TEMPS ARE FORECAST TO RANGE FROM THE L50S
ACROSS THE MTN VALLEYS TO L60S EAST...OR AROUND 10 DEGREES ABOVE
NORMAL. THIS WILL SET THE STAGE FOR RECORD TO NEAR RECORD HIGH
TEMPERATURES EACH DAY. HERE ARE THE RECORDS FOR WEDNESDAY AND
THURSDAY FOR KGSP...KCLT...AND KAVL:
KGSP
MAY 2ND 90F IN 1959 FORECAST 90F
MAY 3RD 91F IN 1959 FORECAST 90F
KCLT
MAY 2ND 91F IN 1959 FORECAST 88F
MAY 3RD 94F IN 1902 FORECAST 91F
KAVL
MAY 2ND 88F IN 1935 FORECAST 85F
MAY 3RD 85F IN 1965 FORECAST 86F
WEDNESDAY AND THURSDAY...THE ENVIRONMENT WILL CHANGE LITTLE FROM DAY
TO DAY. FORECAST SOUNDINGS FEATURE A WEAK INVERSION AROUND H8 WITH
CIN VALUES RANGING BETWEEN 30 TO 60 J/KG. WIND FIELDS SHOULD RESULT
IN ONLY WEAK SHEAR...ESPECIALLY ON THURSDAY. THE STORM MODE SHOULD
REMAIN AS PULSE STORMS. GIVEN THE LINGERING INVERSION...LACK OF A
TRIGGER...AND SLOW STORM MOTIONS WILL FAVOR SCHC POPS EAST OF THE
MTNS...WITH CHC POPS ACROSS THE RIDGES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 145 PM MONDAY...THE MEDIUM RANGE MODELS HAVE BEEN RATHER
CHANGEABLE. MOST RECENT HPC WORD SAYS BLENDING ECMWF AND GEFS
ENSEMBLES ARE THE BEST WAY TO GO. WHEN COMPARING THE OPERATIONAL
GFS AND ECMWF START THE MEDIUM RANGE IN A MODERATE 500MB RIDGE
THURSDAY NIGHT. BOTH SHOW THURSDAY EVENING CONVECTION FROM THE
VIRGINIAS TO EASTERN NC. THIS TREND DIMINISHES FOR LATE FRIDAY AS
THE RIDGE FLATTENS. GOING INTO THE WEEKEND...THESE TWO MODELS
DIVERGE IN SOLUTIONS. THE RIDGE REBUILDS OVER THE SE ON THE ECMWF
FOR SATURDAY WHILE RIDGE RETROGRADES TO TEXAS ON THE GFS WITH TROF
FORMING OVER EAST. THE LATEST 12Z GFS BRINGS THE COLD FRONT ACROSS
OUR AREA EARLY SUNDAY WHILE THE PREVIOUS RUN WAITED UNTIL LATE
MONDAY. THE MOST RECENT ECMWF HAD A WEAK FRONT CROSSING OUR REGION
MONDAY NIGHT. OF COURSE...WITH THIS BEING A WEEK AWAY WE WILL HAVE
SLIGHT POPS IN FORECAST THROUGH THE GENERAL TIME UNTIL WE CAN NAIL
DOWN A MORE DEFINITE TIME FOR FRONTAL PASSAGE.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AT KCLT...INTENSE TSTMS SHOULD REMAIN CONFINED TO THE NC MTNS AND
WRN FOOTHILLS THIS EVENING. WINDS WILL GENERALLY BE OUT OF THE
SOUTH. STRATUS IS EXPECTED TO DEVELOP OVER THE MIDLANDS AND INTO
CENTRAL NC LATE TONIGHT. THE BACK EDGE OF THE LOW CLOUDS WILL BE
QUITE CLOSE TO THE AIRFIELD. I/VE PUT FEW006 IN THE TAF FOR A FEW
HOURS AROUND SUNRISE. THE RUC BUFKIT REALLY IMPLIES THE LOW CIGS
WILL MAKE IT...BUT THE NAM IS MORE IFFY. TMRW AFTN A FEW TSTMS MAY
APPROACH THE AIRFIELD FROM THE NW LATE IN THE DAY.
ELSEWHERE...STRATUS IS EXPECTED TO DEVELOP EAST OF THE REGION
OVERNIGHT...BUT SHOULD STAY SEVERAL MILES EAST OF ALL THE UPSTATE
TAF SITES. MID LEVEL CLOUDS SHOULD KEEP SKIES CLOUDY ENOUGH TO
PREVENT WIDESPREAD VALLEY FOG IN THE NC MTNS. A STRENGTHENING LLVL
JET SHOULD KEEP THE WINDS UP ENUF IN THE FOOTHILLS AND PIEDMONT TO
PREVENT ANYTHING BUT PATCHY MVFR FOG AS WELL. WINDS WILL GENERALLY
BE OUT OF SOUTH TONIGHT...VEERING TO SW ON TUESDAY. SCT TSTMS WILL
DEVELOP OVER THE MTNS TUE...BUT COVERAGE IS NOT GREAT ENUF TO
INCLUDE IN THE TAF.
OUTLOOK...SCT TSTMS WILL DEVELOP OVER THE MTNS WED-FRI. A MOST
AIRMASS WILL ALLOW AREAS OF FOG AND STRATUS TO FORM IN SPOTS THROUGH
THE END OF THE WEEK AS WELL.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...MCAVOY
SHORT TERM...NED
LONG TERM...DEO
AVIATION...MCAVOY
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1045 PM CDT MON APR 30 2012
.DISCUSSION...ISSUED AT 850 PM CDT/
NO CONVECTION HAS FIRED UP THIS EVENING ACROSS WESTERN CWA AND MAY
NOT DEVELOP AT ALL TONIGHT AS LATEST RUC REALLY NOT SHOWING MUCH
DEVELOPMENT. WEAK BOUNDARY ACROSS FAR NORTHERN CWA MAY SEE AN
ISOLATED STORM OR TWO AFTER MIDNIGHT AS LOW LEVEL JET INCREASES.
WILL TRIM BACK POPS TO 20% AND ONLY ACROSS THE NORTH AFTER MIDNIGHT.
OTHERWISE...INCREASING HIGHS CLOUDS ACROSS CWA FROM THE WEST WITH
LOW CLOUDS SPREADING/DEVELOPING NORTHWARD LATER TONIGHT WITH
INCREASING LOW LEVEL MOISTURE. HAVE MADE ADJUSTMENTS TO GRIDS
EARLIER.
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
SOUTHERLY WINDS WILL INCREASE OVERNIGHT BECOMING SUSTAINED AT 15 TO
20 MPH AFTER ABOUT 9Z. SOME MODELS STILL HINTING AT STRATUS
DEVELOPMENT ACROSS THE AREA AFTER 10Z...THOUGH CONFIDENCE IS LOW.
ANY STRATUS THAT DEVELOPS WILL DISSIPATE AFTER 15Z ON TUESDAY. VFR
CONDITIONS WILL DOMINATE ON TUESDAY...THOUGH THUNDERSTORMS ARE
EXPECTED TO DEVELOP ACROSS THE AREA IN THE AFTERNOON...WITH LOCALLY
REDUCED VISIBILITY IN HEAVIER ACTIVITY.
&&
.PREVIOUS DISCUSSION.../ISSUED AT 340 PM CDT/
EXCITED CUMULUS FIELD CONTINUES TO DEVELOP ACROSS CENTRAL SOUTH
DAKOTA. BY LATE THIS AFTERNOON EXPECT ISOLATED CONVECTION TO
DEVELOP AND SPREAD NORTHEAST AS 850 WARM AIR ADVECTION EXPANDS
NORTHEAST AIDED BY INCREASING LOW LEVEL JET. MODEL SOUNDINGS SUGGEST
THAT THE ELEVATED CONVECTION WILL BE FIGHTING AN INCREASING
CAP...AND HAVE MAINLY CONFINED CONVECTION NORTH AND WEST OF A LINE
FROM LAKE ANDES TO SIOUX FALLS TO WORTHINGTON. FAIR AMOUNT OF LOW
LEVEL STRATUS ACROSS KANSAS THIS AFTERNOON IS ALSO EXPECTED TO DRIFT
NORTH OVERNIGHT. THE CLOUD COVER AND INCREASING WINDS SHOULD KEEP
TEMPERATURES FROM FALLING OFF TOO MUCH TONIGHT...AND HAVE INCREASED
FORECAST LOWS ACROSS THE AREA.
LOW LEVEL STRATUS WILL GRADUALLY MIX OUT THROUGHOUT THE MORNING
HOURS ON TUESDAY. IT APPEARS AS THOUGH THERE WILL BE A FAIR AMOUNT
OF MID AND UPPER LEVEL CLOUDS AROUND...WHICH COULD DAMPEN
INSTABILITY AND HEATING SOMEWHAT AHEAD OF AN APPROACHING COLD FRONT
TOMORROW EVENING. HAVE CONTINUED TO SIDE WITH FORECAST HIGHS
SLIGHTLY COOLER THAN 925 HPA MIXOUT DUE TO CLOUD COVER. MODELS SEEM
TO BE A LITTLE AGGRESSIVE WITH PRECIPITATION ESPECIALLY IN EASTERN
PORTIONS OF FORECAST AREA...AND HAVE BACKED OFF ON TIMING SLIGHTLY.
AS SUCH...HAVE FOCUSED HIGHEST POPS WEST OF I-29 THROUGH 00Z
WEDNESDAY. FORECAST SOUNDINGS SUPPORT SEVERE POTENTIAL...ESPECIALLY
WIND POTENTIAL WITH INVERTED V SOUNDINGS. /BT
THE INTERMEDIATE TERM IN THE MIDDLE OF THE WEEK SHOWS A QUASI-ZONAL
UPPER FLOW WITH SOME UPPER RIDGING OVER THE EASTERN U.S.. A SHORT
WAVE AND THE AFOREMENTIONED SURFACE COLD FRONT MOVE RAPIDLY EASTWARD
ACROSS THE EASTERN HALF OF OUR FORECAST AREA TUESDAY EVENING...WHEN
LOW LEVEL MOISTURE POOLS RAPIDLY ALONG THE CONVERGENCE AXIS. THERE
IS ENOUGH INSTABILITY TO WARRANT A SEVERE THREAT MAINLY ALONG AND
EAST OF I 29...WITH LARGE VALUES OF 100MB ML CAPE AND MODEST 0-6KM
SHEAR. LIKELY POPS ARE ALSO STILL WARRANTED GENERALLY ALONG AND EAST
OF I 29 AS THUNDERSTORMS LIKELY BACKBUILD INTO THE PREVAILING
CORFIDI VECTOR FIELD. AS THE SURFACE BOUNDARY SHIFTS SOUTHEASTWARD
AFTER MIDNIGHT...THE DYNAMICS ARE WELL OFF TO THE EAST AT THAT POINT
SO THUNDERSTORM CHANCES WILL NOT BE VERY GOOD THROUGH OUR SE ZONES
LATE AT NIGHT. LOW TEMPERATURES SHOULD VARY FROM THE LOWER 50S
AROUND HURON TO THE LOWER 60S IN NW IA.
ON WEDNESDAY AND THURSDAY...ANOTHER SURFACE BOUNDARY WILL SET UP
SHOP IN THIS FORECAST AREA CONTINUING TO PROVIDE A FOCUS FOR
THUNDERSTORM DEVELOPMENT. TRIED TO PLACE THE HIGHEST POPS ALONG AND
JUST NORTH OF THE LOW LEVEL BOUNDARY. BUT ONE AREA OF A LOT OF MODEL
DISCREPANCY IS WEDNESDAY NIGHT. A STRONG JET STREAK EXISTS TO THE
NORTH NEAR THE CANADIAN BORDER PLACING THIS FORECAST AREA SQUARELY
IN A RIGHT BACK QUAD ENTRANCE REGION ENHANCING ASCENT. ALL MODELS
SHOW THIS JET STREAK EXTENDING FROM NEAR GRAND FORKS...EASTWARD
ACROSS SOUTHERN ONTARIO...BUT ONLY THE NAM HAS CONVECTIVE
INTERACTION ALONG THE SURFACE BOUNDARY. THEREFORE DECIDED TO FOLLOW
THE NAM SOLUTION WEDNESDAY NIGHT WITH HIGH POPS PRIMARILY RIGHT
ALONG THE I 90 CORRIDOR. A THREAT FOR SOME SEVERE ACTIVITY WILL ALSO
BE PRESENT ESPECIALLY WEDNESDAY EVENING. CONVECTIVELY...THURSDAY IS
A REAL MESS AND CONFIDENCE IS LOW. CONCERNING TEMPERATURES...THE AIR
MASS LOOKS WARM ON WEDNESDAY AND THURSDAY WITH MID 70S TO LOWER 80S
VERY WIDESPREAD...EVEN IF THE MORNINGS START OUT AS STRATUS IN SOME
LOCATIONS. /MJF
IN THE EXTENDED...IN THE LARGE SCALE THE LATEST GFS AND ECMWF ARE IN
PRETTY GOOD GENERAL AGREEMENT IN DEVELOPING UPPER LONG WAVE
TROUGHING THROUGHOUT THE WESTERN U.S...WITH THIS AREA JUST ON THE
WESTERN SIDE OF UPPER RIDGING PARKED IN THE EASTERN PLAINS AND NEAR
THE MS VALLEY. THEREFORE SW FLOW ALOFT WILL BE THE MAIN FEATURE
KEEPING THINGS RATHER STIRRED UP WITH PERIODIC SHORT WAVES MOVING
NORTHEASTWARD ACROSS THE FLOW. ONE SYSTEM TO KEEP AN EYE ON
CONTINUES TO BE ON FRIDAY NIGHT...WHEN A DECENT SHORT WAVE IS
PROGGED TO MOVE ACROSS THIS AREA. IN ADDITION...THE ECMWF AT LEAST
HAS A CORRESPONDING SURFACE FRONTAL WAVE MOVING WITH THE MID LEVEL
DYNAMICS...BUT THE GFS CURRENTLY DOES NOT BACK THAT SOLUTION UP AND
JUST KEEPS A BROAD LOW LEVEL EASTERLY FETCH OF AIR IN PLACE. AT THIS
POINT WITH A NOISY PATTERN...IT IS EXTREMELY DIFFICULT TO TELL WHICH
SOLUTION MAY BE BETTER AT THE SURFACE...ESPECIALLY SINCE THE GEM
GLOBAL IS OFF ON ITS OWN IN WHIPPING A SURFACE FRONT THROUGH THIS
AREA ON THE FRIDAY DAY PERIOD. FROM SATURDAY THROUGH MONDAY...THIS
FORECAST AREA THEN SETS UP AN EAST TO NORTHEAST LOW LEVEL FLOW OF
AIR WITH THE TIMING OF INDIVIDUAL SHORT WAVES VERY PROBLEMATIC. THE
SATURDAY NIGHT THROUGH SUNDAY NIGHT PERIODS LOOK UNSETTLED BUT
AGAIN...EXACT TIMING IS DIFFICULT TO ASCERTAIN. WITH A SW FLOW
ALOFT...INSTABILITY ALOFT WILL BE COMMON AND THE ATMOSPHERE DOES NOT
LOOKED OVERLY CAPPED. SO OFF AND ON RAIN CHANCES ARE PRETTY GOOD
THIS NEXT WEEKEND. FOR TEMPERATURES...THE EXTENDED WILL EXHIBIT A
COOLING TREND...BEGINNING WELL ABOVE NORMAL THEN COOLING TO ABOUT
NORMAL ON SUNDAY AND MONDAY. /MJF
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
850 PM CDT MON APR 30 2012
.DISCUSSION...ISSUED AT 850 PM CDT/
NO CONVECTION HAS FIRED UP THIS EVENNIG ACROSS WESTERN CWA AND MAY
NOT DEVELOP AT ALL TONIGHT AS LATEST RUC REALLY NOT SHOWING MUCH
DEVELOPMENT. WEAK BOUNDARY ACROSS FAR NORTHERN CWA MAY SEE AN
ISOLATED STORM OR TWO AFTER MIDNIGHT AS LOW LEVEL JET INCREASES.
WILL TRIM BACK POPS TO 20% AND ONLY ACROSS THE NORTH AFTER MIDNIGHT.
OTHWERWISE...INCREASING HIGHS CLOUDS ACROSS CWA FROM THE WEST WITH
LOW CLOUDS SPREADING/DEVELOPING NORTHWARD LATER TONIGHT WITH
INCREASING LOW LEVEL MOISTURE. HAVE MADE ADJUSTMENTS TO GRIDS
EARLIER.
&&
.AVIATION.../FOR THE 00Z TAF ISSUANCE/
ISOLATED THUNDERSTORMS WILL BE POSSIBLE THROUGH THE JAMES RIVER
VALLEY WESTWARD BEFORE 04Z...THOUGH THREAT WILL BE MINIMAL.
OTHERWISE...SOUTHERLY WINDS WILL INCREASE OVERNIGHT BECOMING
SUSTAINED AT 15 TO 20 MPH AFTER ABOUT 9Z. SOME MODELS STILL HINTING
AT STRATUS DEVELOPMENT ACROSS THE AREA AFTER 10Z...THOUGH CONFIDENCE
IS LOW.
&&
.PREVIOUS DISCUSSION.../ISSUED AT 340 PM CDT/
EXCITED CUMULUS FIELD CONTINUES TO DEVELOP ACROSS CENTRAL SOUTH
DAKOTA. BY LATE THIS AFTERNOON EXPECT ISOLATED CONVECTION TO
DEVELOP AND SPREAD NORTHEAST AS 850 WARM AIR ADVECTION EXPANDS
NORTHEAST AIDED BY INCREASING LOW LEVEL JET. MODEL SOUNDINGS SUGGEST
THAT THE ELEVATED CONVECTION WILL BE FIGHTING AN INCREASING
CAP...AND HAVE MAINLY CONFINED CONVECTION NORTH AND WEST OF A LINE
FROM LAKE ANDES TO SIOUX FALLS TO WORTHINGTON. FAIR AMOUNT OF LOW
LEVEL STRATUS ACROSS KANSAS THIS AFTERNOON IS ALSO EXPECTED TO DRIFT
NORTH OVERNIGHT. THE CLOUD COVER AND INCREASING WINDS SHOULD KEEP
TEMPERATURES FROM FALLING OFF TOO MUCH TONIGHT...AND HAVE INCREASED
FORECAST LOWS ACROSS THE AREA.
LOW LEVEL STRATUS WILL GRADUALLY MIX OUT THROUGHOUT THE MORNING
HOURS ON TUESDAY. IT APPEARS AS THOUGH THERE WILL BE A FAIR AMOUNT
OF MID AND UPPER LEVEL CLOUDS AROUND...WHICH COULD DAMPEN
INSTABILITY AND HEATING SOMEWHAT AHEAD OF AN APPROACHING COLD FRONT
TOMORROW EVENING. HAVE CONTINUED TO SIDE WITH FORECAST HIGHS
SLIGHTLY COOLER THAN 925 HPA MIXOUT DUE TO CLOUD COVER. MODELS SEEM
TO BE A LITTLE AGGRESSIVE WITH PRECIPITATION ESPECIALLY IN EASTERN
PORTIONS OF FORECAST AREA...AND HAVE BACKED OFF ON TIMING SLIGHTLY.
AS SUCH...HAVE FOCUSED HIGHEST POPS WEST OF I-29 THROUGH 00Z
WEDNESDAY. FORECAST SOUNDINGS SUPPORT SEVERE POTENTIAL...ESPECIALLY
WIND POTENTIAL WITH INVERTED V SOUNDINGS. /BT
THE INTERMEDIATE TERM IN THE MIDDLE OF THE WEEK SHOWS A QUASI-ZONAL
UPPER FLOW WITH SOME UPPER RIDGING OVER THE EASTERN U.S.. A SHORT
WAVE AND THE AFOREMENTIONED SURFACE COLD FRONT MOVE RAPIDLY EASTWARD
ACROSS THE EASTERN HALF OF OUR FORECAST AREA TUESDAY EVENING...WHEN
LOW LEVEL MOISTURE POOLS RAPIDLY ALONG THE CONVERGENCE AXIS. THERE
IS ENOUGH INSTABILITY TO WARRANT A SEVERE THREAT MAINLY ALONG AND
EAST OF I 29...WITH LARGE VALUES OF 100MB ML CAPE AND MODEST 0-6KM
SHEAR. LIKELY POPS ARE ALSO STILL WARRANTED GENERALLY ALONG AND EAST
OF I 29 AS THUNDERSTORMS LIKELY BACKBUILD INTO THE PREVAILING
CORFIDI VECTOR FIELD. AS THE SURFACE BOUNDARY SHIFTS SOUTHEASTWARD
AFTER MIDNIGHT...THE DYNAMICS ARE WELL OFF TO THE EAST AT THAT POINT
SO THUNDERSTORM CHANCES WILL NOT BE VERY GOOD THROUGH OUR SE ZONES
LATE AT NIGHT. LOW TEMPERATURES SHOULD VARY FROM THE LOWER 50S
AROUND HURON TO THE LOWER 60S IN NW IA.
ON WEDNESDAY AND THURSDAY...ANOTHER SURFACE BOUNDARY WILL SET UP
SHOP IN THIS FORECAST AREA CONTINUING TO PROVIDE A FOCUS FOR
THUNDERSTORM DEVELOPMENT. TRIED TO PLACE THE HIGHEST POPS ALONG AND
JUST NORTH OF THE LOW LEVEL BOUNDARY. BUT ONE AREA OF A LOT OF MODEL
DISCREPANCY IS WEDNESDAY NIGHT. A STRONG JET STREAK EXISTS TO THE
NORTH NEAR THE CANADIAN BORDER PLACING THIS FORECAST AREA SQUARELY
IN A RIGHT BACK QUAD ENTRANCE REGION ENHANCING ASCENT. ALL MODELS
SHOW THIS JET STREAK EXTENDING FROM NEAR GRAND FORKS...EASTWARD
ACROSS SOUTHERN ONTARIO...BUT ONLY THE NAM HAS CONVECTIVE
INTERACTION ALONG THE SURFACE BOUNDARY. THEREFORE DECIDED TO FOLLOW
THE NAM SOLUTION WEDNESDAY NIGHT WITH HIGH POPS PRIMARILY RIGHT
ALONG THE I 90 CORRIDOR. A THREAT FOR SOME SEVERE ACTIVITY WILL ALSO
BE PRESENT ESPECIALLY WEDNESDAY EVENING. CONVECTIVELY...THURSDAY IS
A REAL MESS AND CONFIDENCE IS LOW. CONCERNING TEMPERATURES...THE AIR
MASS LOOKS WARM ON WEDNESDAY AND THURSDAY WITH MID 70S TO LOWER 80S
VERY WIDESPREAD...EVEN IF THE MORNINGS START OUT AS STRATUS IN SOME
LOCATIONS. /MJF
IN THE EXTENDED...IN THE LARGE SCALE THE LATEST GFS AND ECMWF ARE IN
PRETTY GOOD GENERAL AGREEMENT IN DEVELOPING UPPER LONG WAVE
TROUGHING THROUGHOUT THE WESTERN U.S...WITH THIS AREA JUST ON THE
WESTERN SIDE OF UPPER RIDGING PARKED IN THE EASTERN PLAINS AND NEAR
THE MS VALLEY. THEREFORE SW FLOW ALOFT WILL BE THE MAIN FEATURE
KEEPING THINGS RATHER STIRRED UP WITH PERIODIC SHORT WAVES MOVING
NORTHEASTWARD ACROSS THE FLOW. ONE SYSTEM TO KEEP AN EYE ON
CONTINUES TO BE ON FRIDAY NIGHT...WHEN A DECENT SHORT WAVE IS
PROGGED TO MOVE ACROSS THIS AREA. IN ADDITION...THE ECMWF AT LEAST
HAS A CORRESPONDING SURFACE FRONTAL WAVE MOVING WITH THE MID LEVEL
DYNAMICS...BUT THE GFS CURRENTLY DOES NOT BACK THAT SOLUTION UP AND
JUST KEEPS A BROAD LOW LEVEL EASTERLY FETCH OF AIR IN PLACE. AT THIS
POINT WITH A NOISY PATTERN...IT IS EXTREMELY DIFFICULT TO TELL WHICH
SOLUTION MAY BE BETTER AT THE SURFACE...ESPECIALLY SINCE THE GEM
GLOBAL IS OFF ON ITS OWN IN WHIPPING A SURFACE FRONT THROUGH THIS
AREA ON THE FRIDAY DAY PERIOD. FROM SATURDAY THROUGH MONDAY...THIS
FORECAST AREA THEN SETS UP AN EAST TO NORTHEAST LOW LEVEL FLOW OF
AIR WITH THE TIMING OF INDIVIDUAL SHORT WAVES VERY PROBLEMATIC. THE
SATURDAY NIGHT THROUGH SUNDAY NIGHT PERIODS LOOK UNSETTLED BUT
AGAIN...EXACT TIMING IS DIFFICULT TO ASCERTAIN. WITH A SW FLOW
ALOFT...INSTABILITY ALOFT WILL BE COMMON AND THE ATMOSPHERE DOES NOT
LOOKED OVERLY CAPPED. SO OFF AND ON RAIN CHANCES ARE PRETTY GOOD
THIS NEXT WEEKEND. FOR TEMPERATURES...THE EXTENDED WILL EXHIBIT A
COOLING TREND...BEGINNING WELL ABOVE NORMAL THEN COOLING TO ABOUT
NORMAL ON SUNDAY AND MONDAY. /MJF
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
$$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
950 PM CDT MON APR 30 2012
.UPDATE...
HAVE UPDATED THE FORECAST TO REMOVE THUNDER MENTION EXCEPT FOR
EASTERN AREAS AND REMOVED SEVERE TSTORM WATCH EXCEPT FOR THE
ROLLING PLAINS.
&&
PREV DISCUSSION... /ISSUED 226 PM CDT MON APR 30 2012/
SHORT TERM...
WE ARE BASICALLY IN A WAIT AND SEE MODE FOR WHEN/IF SEVERE WEATHER
WILL INITIATE. 19Z RADAR IMAGE SHOWS TWO BOUNDARIES ACROSS THE
AREA...FIRST ONE WAS LOCATED SOUTHWEST OF LUBBOCK WHICH WAS ORIENTED
NORTHWEST TO SOUTHEAST WITH THE SECOND ONE LOCATED OVER THE ROLLING
PLAINS ORIENTED NORTH/SOUTH. LATEST VISIBLE SATELLITE IMAGERY AND
OFFICE TOWER CAMERA ARE SHOWING CU FIELD TRYING TO DEVELOP ALONG
THIS BOUNDARY WHILE SKIES ARE TRYING TO CLEAR IMMEDIATELY
EAST/NORTHEAST OF THE BOUNDARY. THERE IS LITTLE IN THE WAY OF
DYNAMICS TO HELP SHARPEN THE DRYLINE AND PUSH IT EAST SO FEEL THAT
THE WESTERN BOUNDARY SHOULD NOT MOVE TOO MUCH FURTHER EAST.
DEWPOINTS IMMEDIATELY NORTH AND EAST OF THE BOUNDARY HAVE ACTUALLY
BEEN SLOWLY RISING AS EVAPORATION TAKES PLACE FROM THE RAINFALL
YESTERDAY WHICH SHOULD ALSO HELP TO SHARPEN UP THE BOUNDARY A BIT.
19Z RUC RUN KEEPS KLBB CAPPED ALTHOUGH STRENGTH OF THE CAP IS NOT
INSURMOUNTABLE AND THE LATEST HRRR RUNS CONTINUE TO TRY AND BREAK
OUT CONVECTION. THUS...SEVERE WEATHER THREAT STILL LOOKS GOOD WITH
MAIN THREATS LARGE HAIL UP TO BASEBALL SIZE AS WELL AS DAMAGING
WINDS... BUT AN ISOLATED TORNADO STILL REMAINS POSSIBLE.
FORECAST FOR TONIGHT INTO TOMORROW WILL HINGE ON HOW THINGS DEVELOP
THIS AFTERNOON. LOW TEMPS WILL REMAIN A FEW DEGREES ABOVE NORMAL
OVER MOST OF THE AREA AS RICH LOW LEVEL MOISTURE REMAIN IN PLACE
OVER THE REGION. DRYLINE TOMORROW MAY TRY TO PUSH A BIT FURTHER
EAST TOMORROW BUT POOR HANDLE OF THE DRYLINE LAST SEVERAL RUNS IN
THE MODELS MAKE ME A BIT SUSPICIOUS OF WHERE IT MAY BE LOCATED
TOMORROW. IF THE WIND DOES INCREASE OUT OF THE SOUTHWEST...
TEMPERATURES WEST OF THE DRYLINE MAY JUMP INTO THE LOW/MID 90S WHILE
ALONG AND EAST OF THE DRYLINE...TEMPERATURES WILL REMAIN IN THE
80S. ALSO WENT AHEAD AND BUMPED POPS UP INTO THE LOW END OF SLIGHT
CHANCE FOR THE ROLLING PLAINS AS THERE WILL ONCE AGAIN BE QUITE A
BIT OF INSTABILITY EAST OF THE DRYLINE ALTHOUGH CAP STRENGTH MAY
LIMIT THE AMOUNT OF CONVECTION FOR TOMORROW.
JORDAN
LONG TERM...
AN UA LOW ACROSS THE EASTERN PACIFIC IS PROGGED TO NEAR THE BAJA OF
CALIFORNIA LATE TOMORROW NIGHT/EARLY WEDNESDAY MORNING...THUS
PROMOTING THE SHARPENING OF SW FLOW ALOFT. AS SUCH...THE DRYLINE
WILL BE A PROMINENT MESOSCALE FEATURE THROUGHOUT THE EXTENDED
FORECAST. FORECAST MODELS HINT AT QPF ALONG THE DRYLINE /LOCATED OFF
THE CAPROCK/ TOMORROW NIGHT...AS AN IMPULSE IN THE SW FLOW ALOFT
MOVES ACROSS THE SOUTH PLAINS. FORECAST SOLUTIONS DISPLAYED ADEQUATE
CONVERGENCE ALONG THE DRYLINE...PWATS AOA 1.00 INCH AND SFC AND MID
LEVEL INSTABILITY/CAPE OF APPROXIMATELY 1200 J/KG ACROSS THE ROLLING
PLAINS. ALTHOUGH PROGGED MODEL SOUNDINGS EXHIBITED MOISTENED
MID-LEVELS...LOW LEVELS APPEAR RELATIVELY DRY. CURRENT THINKING IS
THAT GUSTY WINDS WILL BE THE PRIMARY THREATS...WITH LITTLE RAINFALL
ACCUMULATION. HOWEVER...HAVE OPTED TO ADD MENTIONABLE POPS ACROSS
THE ROLLING PLAINS NEAREST TO THE BEST MOISTURE AXIS...AS THE
AFOREMENTIONED EMBEDDED DISTURBANCE MAY JUST BE THE SYNOPTIC SPARK
TO INITIATE STORMS. BY THURSDAY THE UA LOW WILL BE TRANSLATING
ACROSS THE BAJA OF CALIFORNIA. ONCE AGAIN THERE ARE HINTS OF CI JUST
SOUTH OF THE CWA ALONG THE DRYLINE...WHICH IS SPATIALLY DISTRIBUTED
ON THE CAPROCK EARLY THURSDAY MORNING. HOWEVER EMBEDDED IMPULSES IN
THE FLOW ALOFT BRUSHING THE FAR SERN ZONES THURSDAY NIGHT COULD
PROMOTE ADDITIONAL CHANCES OF PRECIP ACROSS THE SOUTHERN ROLLING
PLAINS. WILL HOLD OFF ON A PRECIP MENTION ATTM...AS BEST INSTABILITY
APPEARS TO BE SE OF THE FA.
THEREAFTER...UA RIDGING WILL COMMENCE TO MOVE EAST ACROSS THE REGION
FRI-SAT AS LACK OF PRECIP DESPITE A LINGERING DRYLINE SUGGESTS A
DECENT CAPPING INVERSION AT PLAY. WILL HOWEVER NEED TO MONITOR LATER
MODEL RUNS AS TEMPS IN THE 90S MAY BE ENOUGH TO BREAK THE CAP...AND
INITIATE THUNDERSTORM DEVELOPMENT. THE INFLUENCE OF THE UA RIDGE
WILL BE SHORT-LIVED AS IT SHIFTS EAST OF THE SOUTHERN PLAINS BY
SUNDAY...THANKS TO A NW PACIFIC UA LOW DEEPENING ACROSS THE GREAT
BASIN /THIS IS A RADICAL CHANGE FROM THE PREVIOUS RUN/. HINTS OF
CONVECTION OCCURRING NEAR THE STATE LINE ALONG THE DRYLINE
SUNDAY/MONDAY MORNING IS DISPLAYED BY BOTH THE GFS AND ECMWF
SOLUTIONS. WILL HOWEVER MAINTAIN SILENT POPS ATTM SINCE NEXT MONDAY
IS DAY 7 AND AS MENTIONED...A LOT OF THINGS CAN CHANGE.
FIRE WEATHER...
A DRYLINE IS EXPECTED TO SHARPEN ACROSS THE ROLLING PLAINS ON
WEDNESDAY...AND ALLOW DRIER AIR WEST OF THE DRYLINE...TO FILTER
ACROSS PORTIONS OF THE REGION. TEMPS APPROXIMATELY 15 DEGREES ABOVE
NORMAL WILL PROMOTE RELATIVE HUMIDITY VALUES TO FALL BELOW 15
PERCENT...AS 20-FOOT WIND SPEEDS NEAR/SLIGHTLY EXCEED 20 MPH. AS A
RESULT...ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS MAY
OCCUR...AND A MENTION BEYOND THE HAZARDOUS WEATHER OUTLOOK MAY BE
WARRANTED. ONLY MITIGATING FACTOR MAY WHERE AND HOW MUCH EXPECTED
RAINFALL THE AREA WILL RECEIVE TODAY...WHICH COULD PROMOTE GREENUP
AND HIGHER RELATIVE HUMIDITY VALUES THAN ANTICIPATED.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 55 91 55 88 53 / 10 0 0 0 0
TULIA 60 92 58 90 55 / 10 10 10 10 10
PLAINVIEW 61 93 59 91 57 / 10 10 10 10 10
LEVELLAND 61 92 59 93 58 / 10 10 10 10 10
LUBBOCK 63 92 61 93 60 / 10 10 10 10 10
DENVER CITY 59 94 58 93 58 / 10 10 10 10 10
BROWNFIELD 62 94 59 94 58 / 10 10 10 10 10
CHILDRESS 64 92 64 94 62 / 40 20 20 10 10
SPUR 66 91 62 94 60 / 40 20 20 10 10
ASPERMONT 68 91 64 97 63 / 40 20 20 10 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
915 PM CDT MON APR 30 2012
.UPDATE...
REGARDING THUNDERSTORM CHANCES ACROSS NORTH TEXAS TONIGHT...
WATCHING THREE AREAS OF UPSTREAM CONVECTION FOR THE POTENTIAL TO
EVENTUALLY AFFECT PORTIONS OF THE CWA TONIGHT.
THE FIRST AREA OF CONVECTION WAS IN PLACE OVER THE FAR EAST TEXAS
PANHANDLE AND OVER FAR WESTERN OKLAHOMA. THIS CLUSTER OF INTENSE
CONVECTION HAS BEEN EXPANDING IN COVERAGE AND IS SHOWING SIGNS OF
DEVELOPING INTO AN EAST/WEST ORIENTED LINE FROM MEMPHIS TX EAST
TOWARDS ELK CITY OK. THERE IS A SMALL CHANCE THAT THIS CLUSTER OF
STORMS WILL GROW UPSCALE INTO A LARGER LINE AND MOVE EAST
SOUTHEAST...EVENTUALLY MOVING TOWARDS THE RED RIVER COUNTIES OF
THE CWA AFTER MIDNIGHT. THE LEVEL OF CONFIDENCE IN THIS SCENARIO
PANNING OUT IS LOW...BUT WILL MAINTAIN 20 POPS FROM PREVIOUS
FORECAST AS THE CONVECTION IS IN PLACE AND HAS A BETTER CHANCE AT
MOVING EAST-SOUTHEAST ONCE THE LOW LEVEL JET STRENGTHENS TONIGHT.
THE SECOND AREA OF CONVECTION WAS A SLOW-MOVING CLUSTER OF STORMS
JUST WEST OF ASPERMONT. AS OF 9 PM CDT THIS CLUSTER HAS NOT SHOWN
ANY SIGN OF UPSCALE GROWTH...HOWEVER THE HRRR CONTINUES TO
INDICATE THAT THIS CLUSTER WILL EVENTUALLY EXPAND IN COVERAGE AND
THEN ACCELERATE EAST TOWARDS THE CWA LATE THIS EVENING THROUGH THE
OVERNIGHT HOURS. AGAIN...THINK THAT ANY UPSCALE GROWTH IS UNLIKELY
UNTIL WE GET A STRONG LOW LEVEL JET TO DEVELOP OVER THE
REGION...SO WILL CONTINUE TO MONITOR FOR THE POTENTIAL FOR UPSCALE
GROWTH HERE INTO THE OVERNIGHT HOURS. THE LEVEL OF CONFIDENCE IN
THIS COMPLEX GROWING UPSCALE AND AFFECTING OUR CWA IS SLIGHTLY
BETTER THAN THE NORTHERN CLUSTER OF CONVECTION DISCUSSED
ABOVE...HOWEVER IT IS SOMEWHAT TROUBLING THAT CONVECTION REMAINS
SMALL AND VERY SLOW MOVING IN NATURE AFTER SUNSET. WITH THIS
CONVECTION IN PLACE UPSTREAM...WILL LEAVE THE SEVERE THUNDERSTORM
WATCH IN PLACE BUT WILL CLOSELY MONITOR THE CONVECTIVE EVOLUTION
OF THIS CLUSTER ONCE AREA VAD WIND PROFILES INDICATE THAT THE LOW
LEVEL JET HAS BECOME ESTABLISHED. IF UPSCALE GROWTH IS NOT
NOTED...MAY COORDINATE WITH SPC AND SURROUNDING OFFICES FOR AN
EARLY EXPIRATION FOR OUR PORTION OF SEVERE THUNDERSTORM WATCH
NUMBER 213 BY MIDNIGHT.
THE LAST AREA OF CONVECTION WAS IN PLACE JUST SOUTH OF OZONA AS OF
9 PM CDT. THIS CONVECTION HAS ALREADY GROWN UPSCALE INTO A LINEAR
MCS AND WAS MOVING EAST-SOUTHEAST AT THE TIME OF THIS DISCUSSION.
THERE IS A SMALL CHANCE THAT THIS LINE WILL CLIP THE FAR SOUTHERN
PORTION OF THE CWA IF STRONG CONVECTION WERE TO BE MAINTAINED
ALONG THE ENTIRE LINE. HOWEVER CONFIDENCE IN THIS SCENARIO PANNING
OUT IS VERY LOW...SO DID NOT INCLUDE ANY POPS IN THE OVERNIGHT
FORECAST FOR THIS SOUTHERN COMPLEX OF STORMS. THE FACT THAT
UPSCALE GROWTH OCCURRED WITH THIS COMPLEX DOES AT LEAST GIVE SOME
MERIT TO OTHER UPSCALE GROWTH WITH THE TX PANHANDLE CLUSTERS BY
MIDNIGHT.
WILL CONTINUE TO MONITOR ALL UPSTREAM CONVECTION LATE THIS EVENING
AND UPDATE THE FORECAST AS NEEDED IF ONE OR MORE OF THESE
COMPLEXES LOOKS MORE LIKELY TO AFFECT PORTIONS OF NORTH TX
TONIGHT. ANY THUNDERSTORMS THAT AFFECT NORTH TX TONIGHT WILL BE
PRIMARILY A LARGE HAIL AND HEAVY RAINFALL THREAT...HOWEVER A WELL
ORGANIZED LINEAR MCS WOULD CERTAINLY POSE A STRAIGHT LINE WIND
THREAT AS WELL. THE POTENTIAL FOR WIDESPREAD DAMAGING WINDS IS
EXPECTED TO BE DAMPENED BY THUNDERSTORM ACTIVITY MOVING INTO THE
AREA WELL AFTER SUNSET WITH A NOCTURNAL INVERSION FIRMLY IN PLACE.
CAVANAUGH
&&
.AVIATION...
/00Z TAFS/
VFR CONDITIONS PREVAILING ACROSS NORTH TEXAS THIS EVENING WITH
SCATTERED CONVECTION DEVELOPING ACROSS WEST TEXAS. NORTH TEXAS IS
UNSTABLE WITH LITTLE INHIBITION TO CONVECTIVE DEVELOPMENT HOWEVER
THERE APPEARS TO BE INSUFFICIENT LARGE SCALE FORCING FOR ASCENT ACROSS
OUR AREA FOR THUNDERSTORMS. LATEST RUC GUIDANCE INDICATES THAT CAP
WILL STRENGTHEN OVER THE NEXT SEVERAL HOURS WITH THUNDERSTORM
CHANCES BECOMING MORE UNLIKELY. WILL HAVE TO WATCH CONVECTION OFF
TO THE WEST AND NORTHWEST AS IT MAY MAKE A RUN AT OUR AREA. AT
THIS TIME WILL LEAVE MENTION OF PRECIPITATION OUT OF THE CURRENT
FORECAST. MAIN CONCERN THROUGH THE OVERNIGHT HOURS WILL BE
RETURNING MVFR CIGS BY 9-10Z. WILL CONTINUE WITH BKN/OVC015 ACROSS
THE AREA... SCATTERING OUT BY MIDDAY TUESDAY. SOUTHERLY WINDS 15
TO 20 KTS WILL CONTINUE THROUGH TUESDAY.
DUNN
&&
.PREV DISCUSSION... /ISSUED 317 PM CDT MON APR 30 2012/
DESPITE PERSISTENT CLOUD COVER TODAY...CONVECTIVE TEMPERATURES IN
THE LOWER 80S HAVE BEEN REACHED AND ISOLATED SHOWERS AND
THUNDERSTORMS ARE DEVELOPING ACROSS THE REGION. MOST OF THE
ACTIVITY STRETCHES FROM THE DFW METROPLEX NORTH AND NORTHEAST.
THROUGH THE EARLY EVENING HOURS...A STRONG THUNDERSTORM WILL STILL
BE POSSIBLE BUT GENERALLY EXPECT THIS ACTIVITY TO REMAIN SUB-
SEVERE DUE TO A LACK OF SURFACE AND LARGE SCALE FORCING. ASIDE
FROM THIS ACTIVITY...STRONG THUNDERSTORMS ARE ALSO DEVELOPING IN
FAR WEST TEXAS THIS AFTERNOON. ADDITIONAL DEVELOPMENT IN WEST
TEXAS IS EXPECTED THIS AFTERNOON AND EVENING...NEAR THE
DRYLINE...BUT DO NOT EXPECT THIS ACTIVITY TO REACH NORTH TEXAS.
MANY OF THE MODELS...INCLUDING THE HI-RES MODELS...ARE DEVELOPING
A MCS NORTHWEST OF THE REGION LATE TONIGHT. HOWEVER...MOST OF THE
MODELS TRACK THIS SYSTEM TO THE EAST AND KEEP IT WELL NORTH OF THE
RED RIVER. WILL MAINTAIN THE LOW POPS IN THE FAR NORTHWEST AND
NORTHERN COUNTIES OF THE CWA TONIGHT IN CASE THE TRACK OF THIS
SYSTEM CHANGES OR ADDITIONAL DEVELOPMENT OCCURS ALONG ANY OUTFLOW
BOUNDARIES TO THE SOUTH.
SOUTHWEST FLOW ALOFT WILL CONTINUE ACROSS THE REGION FOR THE NEXT
FEW DAYS AND THEN AN UPPER LEVEL RIDGE WILL BUILD IN OVER THE
WEEKEND. THE CAP IS FORECAST TO STRENGTHEN OVER NORTH TEXAS THUS
THE RAIN POTENTIAL LOOKS LOW FOR MOST OF THE NEXT SEVEN DAYS. WITH
SOUTHWEST FLOW ALOFT CONTINUING FOR THE NEXT FEW DAYS...IT IS
POSSIBLE THAT SOME ISOLATED ACTIVITY COULD DEVELOP IN THE
AFTERNOON/EVENING HOURS...BUT CONFIDENCE IS TOO LOW TO MENTION AN
ISOLATED WORDING THE FORECAST. THE EXCEPTION TO THIS COULD BE LATE
THIS WEEK WHEN A DISTURBANCE MOVES ACROSS BAJA CALIFORNIA AND
POSSIBLY INTO NORTH TEXAS. THE MODELS CONTINUE TO STRUGGLE WITH THE
TRACK...TIMING...AND STRENGTH OF THIS FEATURE...THUS WILL CONTINUE
WITH A DRY FORECAST FOR NOW. HOWEVER...SOME OF THE MODELS THINK WE
MAY SEE SOME RAIN ON SATURDAY.
WARM TEMPERATURES ARE EXPECTED TO CONTINUE FOR THE NEXT WEEK.
THURSDAY COULD BE ONE OF THE WARMEST DAYS OF THIS WEEK AND THEN
THE BEGINNING OF NEXT WEEK LOOKS WARM WITH TEMPERATURES
APPROACHING 90 DEGREES OVER MUCH OF NORTH TEXAS. THE LOW LEVEL JET
AFTER TOMORROW WILL BE SLIGHTLY WEAKER...THUS MORNING STRATUS
WILL LIKELY NOT BE AS AGGRESSIVE AS IT TYPICALLY IS THIS TIME OF
YEAR. AFTERNOON WINDS WILL BE BREEZY OVER THE NORTHWEST HALF OF
THE CWA.
82/JLD
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 70 86 69 87 70 / 10 10 10 10 10
WACO, TX 71 88 70 89 69 / 10 10 10 10 10
PARIS, TX 68 84 67 85 67 / 20 10 10 10 10
DENTON, TX 69 85 68 86 68 / 20 10 10 10 10
MCKINNEY, TX 69 85 68 86 68 / 20 10 10 10 10
DALLAS, TX 71 86 70 88 70 / 10 10 10 10 10
TERRELL, TX 69 85 68 85 68 / 10 10 10 10 10
CORSICANA, TX 69 86 68 86 69 / 10 10 10 10 10
TEMPLE, TX 70 85 69 89 68 / 10 10 10 10 10
MINERAL WELLS, TX 67 85 66 87 67 / 20 10 10 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
634 PM CDT MON APR 30 2012
.AVIATION...
THUNDERSTORM DEVELOPMENT IS ONGOING AT THIS HOUR AND AN ISOLATED
STORM IS EXPECTED TO AFFECT THE KCDS TERMINAL SHORTLY.
AFTERWARDS...MORE WIDESPREAD STORM DEVELOPMENT MAY OCCUR AFFECTING
THE KCDS AREA. STORMS ARE NOT EXPECTED TO AFFECT THE KLBB TERMINAL
THIS EVENING. MINOR VISBY OR CIG RESTRICTIONS MAY BE POSSIBLE AT
BOTH TERMINALS BY DAYBREAK ON TUESDAY. HOWEVER...CONFIDENCE IS NOT
HIGH IN THIS OCCURRENCE AT THE MOMENT BUT A BETTER CHANCE WILL
EXIST AT KCDS THAN AT KLBB. ISOLATED STORMS MAY AGAIN BE POSSIBLE
AT KCDS TUESDAY AFTERNOON BUT HAVE LEFT ANY MENTION OUT OF THE TAF
AT THE MOMENT.
&&
.PREV DISCUSSION... /ISSUED 226 PM CDT MON APR 30 2012/
SHORT TERM...
WE ARE BASICALLY IN A WAIT AND SEE MODE FOR WHEN/IF SEVERE WEATHER
WILL INITIATE. 19Z RADAR IMAGE SHOWS TWO BOUNDARIES ACROSS THE
AREA...FIRST ONE WAS LOCATED SOUTHWEST OF LUBBOCK WHICH WAS ORIENTED
NORTHWEST TO SOUTHEAST WITH THE SECOND ONE LOCATED OVER THE ROLLING
PLAINS ORIENTED NORTH/SOUTH. LATEST VISIBLE SATELLITE IMAGERY AND
OFFICE TOWER CAMERA ARE SHOWING CU FIELD TRYING TO DEVELOP ALONG
THIS BOUNDARY WHILE SKIES ARE TRYING TO CLEAR IMMEDIATELY
EAST/NORTHEAST OF THE BOUNDARY. THERE IS LITTLE IN THE WAY OF
DYNAMICS TO HELP SHARPEN THE DRYLINE AND PUSH IT EAST SO FEEL THAT
THE WESTERN BOUNDARY SHOULD NOT MOVE TOO MUCH FURTHER EAST.
DEWPOINTS IMMEDIATELY NORTH AND EAST OF THE BOUNDARY HAVE ACTUALLY
BEEN SLOWLY RISING AS EVAPORATION TAKES PLACE FROM THE RAINFALL
YESTERDAY WHICH SHOULD ALSO HELP TO SHARPEN UP THE BOUNDARY A BIT.
19Z RUC RUN KEEPS KLBB CAPPED ALTHOUGH STRENGTH OF THE CAP IS NOT
INSURMOUNTABLE AND THE LATEST HRRR RUNS CONTINUE TO TRY AND BREAK
OUT CONVECTION. THUS...SEVERE WEATHER THREAT STILL LOOKS GOOD WITH
MAIN THREATS LARGE HAIL UP TO BASEBALL SIZE AS WELL AS DAMAGING
WINDS... BUT AN ISOLATED TORNADO STILL REMAINS POSSIBLE.
FORECAST FOR TONIGHT INTO TOMORROW WILL HINGE ON HOW THINGS DEVELOP
THIS AFTERNOON. LOW TEMPS WILL REMAIN A FEW DEGREES ABOVE NORMAL
OVER MOST OF THE AREA AS RICH LOW LEVEL MOISTURE REMAIN IN PLACE
OVER THE REGION. DRYLINE TOMORROW MAY TRY TO PUSH A BIT FURTHER
EAST TOMORROW BUT POOR HANDLE OF THE DRYLINE LAST SEVERAL RUNS IN
THE MODELS MAKE ME A BIT SUSPICIOUS OF WHERE IT MAY BE LOCATED
TOMORROW. IF THE WIND DOES INCREASE OUT OF THE SOUTHWEST...
TEMPERATURES WEST OF THE DRYLINE MAY JUMP INTO THE LOW/MID 90S WHILE
ALONG AND EAST OF THE DRYLINE...TEMPERATURES WILL REMAIN IN THE
80S. ALSO WENT AHEAD AND BUMPED POPS UP INTO THE LOW END OF SLIGHT
CHANCE FOR THE ROLLING PLAINS AS THERE WILL ONCE AGAIN BE QUITE A
BIT OF INSTABILITY EAST OF THE DRYLINE ALTHOUGH CAP STRENGTH MAY
LIMIT THE AMOUNT OF CONVECTION FOR TOMORROW.
JORDAN
LONG TERM...
AN UA LOW ACROSS THE EASTERN PACIFIC IS PROGGED TO NEAR THE BAJA OF
CALIFORNIA LATE TOMORROW NIGHT/EARLY WEDNESDAY MORNING...THUS
PROMOTING THE SHARPENING OF SW FLOW ALOFT. AS SUCH...THE DRYLINE
WILL BE A PROMINENT MESOSCALE FEATURE THROUGHOUT THE EXTENDED
FORECAST. FORECAST MODELS HINT AT QPF ALONG THE DRYLINE /LOCATED OFF
THE CAPROCK/ TOMORROW NIGHT...AS AN IMPULSE IN THE SW FLOW ALOFT
MOVES ACROSS THE SOUTH PLAINS. FORECAST SOLUTIONS DISPLAYED ADEQUATE
CONVERGENCE ALONG THE DRYLINE...PWATS AOA 1.00 INCH AND SFC AND MID
LEVEL INSTABILITY/CAPE OF APPROXIMATELY 1200 J/KG ACROSS THE ROLLING
PLAINS. ALTHOUGH PROGGED MODEL SOUNDINGS EXHIBITED MOISTENED
MID-LEVELS...LOW LEVELS APPEAR RELATIVELY DRY. CURRENT THINKING IS
THAT GUSTY WINDS WILL BE THE PRIMARY THREATS...WITH LITTLE RAINFALL
ACCUMULATION. HOWEVER...HAVE OPTED TO ADD MENTIONABLE POPS ACROSS
THE ROLLING PLAINS NEAREST TO THE BEST MOISTURE AXIS...AS THE
AFOREMENTIONED EMBEDDED DISTURBANCE MAY JUST BE THE SYNOPTIC SPARK
TO INITIATE STORMS. BY THURSDAY THE UA LOW WILL BE TRANSLATING
ACROSS THE BAJA OF CALIFORNIA. ONCE AGAIN THERE ARE HINTS OF CI JUST
SOUTH OF THE CWA ALONG THE DRYLINE...WHICH IS SPATIALLY DISTRIBUTED
ON THE CAPROCK EARLY THURSDAY MORNING. HOWEVER EMBEDDED IMPULSES IN
THE FLOW ALOFT BRUSHING THE FAR SERN ZONES THURSDAY NIGHT COULD
PROMOTE ADDITIONAL CHANCES OF PRECIP ACROSS THE SOUTHERN ROLLING
PLAINS. WILL HOLD OFF ON A PRECIP MENTION ATTM...AS BEST INSTABILITY
APPEARS TO BE SE OF THE FA.
THEREAFTER...UA RIDGING WILL COMMENCE TO MOVE EAST ACROSS THE REGION
FRI-SAT AS LACK OF PRECIP DESPITE A LINGERING DRYLINE SUGGESTS A
DECENT CAPPING INVERSION AT PLAY. WILL HOWEVER NEED TO MONITOR LATER
MODEL RUNS AS TEMPS IN THE 90S MAY BE ENOUGH TO BREAK THE CAP...AND
INITIATE THUNDERSTORM DEVELOPMENT. THE INFLUENCE OF THE UA RIDGE
WILL BE SHORT-LIVED AS IT SHIFTS EAST OF THE SOUTHERN PLAINS BY
SUNDAY...THANKS TO A NW PACIFIC UA LOW DEEPENING ACROSS THE GREAT
BASIN /THIS IS A RADICAL CHANGE FROM THE PREVIOUS RUN/. HINTS OF
CONVECTION OCCURRING NEAR THE STATE LINE ALONG THE DRYLINE
SUNDAY/MONDAY MORNING IS DISPLAYED BY BOTH THE GFS AND ECMWF
SOLUTIONS. WILL HOWEVER MAINTAIN SILENT POPS ATTM SINCE NEXT MONDAY
IS DAY 7 AND AS MENTIONED...A LOT OF THINGS CAN CHANGE.
FIRE WEATHER...
A DRYLINE IS EXPECTED TO SHARPEN ACROSS THE ROLLING PLAINS ON
WEDNESDAY...AND ALLOW DRIER AIR WEST OF THE DRYLINE...TO FILTER
ACROSS PORTIONS OF THE REGION. TEMPS APPROXIMATELY 15 DEGREES ABOVE
NORMAL WILL PROMOTE RELATIVE HUMIDITY VALUES TO FALL BELOW 15
PERCENT...AS 20-FOOT WIND SPEEDS NEAR/SLIGHTLY EXCEED 20 MPH. AS A
RESULT...ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS MAY
OCCUR...AND A MENTION BEYOND THE HAZARDOUS WEATHER OUTLOOK MAY BE
WARRANTED. ONLY MITIGATING FACTOR MAY WHERE AND HOW MUCH EXPECTED
RAINFALL THE AREA WILL RECEIVE TODAY...WHICH COULD PROMOTE GREENUP
AND HIGHER RELATIVE HUMIDITY VALUES THAN ANTICIPATED.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 55 91 55 88 53 / 30 0 0 0 0
TULIA 60 92 58 90 55 / 40 10 10 10 10
PLAINVIEW 61 93 59 91 57 / 40 10 10 10 10
LEVELLAND 61 92 59 93 58 / 10 10 10 10 10
LUBBOCK 63 92 61 93 60 / 20 10 10 10 10
DENVER CITY 59 94 58 93 58 / 10 10 10 10 10
BROWNFIELD 62 94 59 94 58 / 10 10 10 10 10
CHILDRESS 64 92 64 94 62 / 40 20 20 10 10
SPUR 66 91 62 94 60 / 40 20 20 10 10
ASPERMONT 68 91 64 97 63 / 40 20 20 10 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
605 PM CDT MON APR 30 2012
.AVIATION...
/00Z TAFS/
VFR CONDITIONS PREVAILING ACROSS NORTH TEXAS THIS EVENING WITH
SCATTERED CONVECTION DEVELOPING ACROSS WEST TEXAS. NORTH TEXAS IS
UNSTABLE WITH LITTLE INHIBITION TO CONVECTIVE DEVELOPMENT HOWEVER
THERE APPEARS TO BE INSUFFICIENT LARGE SCALE FORCING FOR ASCENT ACROSS
OUR AREA FOR THUNDERSTORMS. LATEST RUC GUIDANCE INDICATES THAT CAP
WILL STRENGTHEN OVER THE NEXT SEVERAL HOURS WITH THUNDERSTORM
CHANCES BECOMING MORE UNLIKELY. WILL HAVE TO WATCH CONVECTION OFF
TO THE WEST AND NORTHWEST AS IT MAY MAKE A RUN AT OUR AREA. AT
THIS TIME WILL LEAVE MENTION OF PRECIPITATION OUT OF THE CURRENT
FORECAST. MAIN CONCERN THROUGH THE OVERNIGHT HOURS WILL BE
RETURNING MVFR CIGS BY 9-10Z. WILL CONTINUE WITH BKN/OVC015 ACROSS
THE AREA... SCATTERING OUT BY MIDDAY TUESDAY. SOUTHERLY WINDS 15
TO 20 KTS WILL CONTINUE THROUGH TUESDAY.
DUNN
&&
.PREV DISCUSSION... /ISSUED 317 PM CDT MON APR 30 2012/
DESPITE PERSISTENT CLOUD COVER TODAY...CONVECTIVE TEMPERATURES IN
THE LOWER 80S HAVE BEEN REACHED AND ISOLATED SHOWERS AND
THUNDERSTORMS ARE DEVELOPING ACROSS THE REGION. MOST OF THE
ACTIVITY STRETCHES FROM THE DFW METROPLEX NORTH AND NORTHEAST.
THROUGH THE EARLY EVENING HOURS...A STRONG THUNDERSTORM WILL STILL
BE POSSIBLE BUT GENERALLY EXPECT THIS ACTIVITY TO REMAIN SUB-
SEVERE DUE TO A LACK OF SURFACE AND LARGE SCALE FORCING. ASIDE
FROM THIS ACTIVITY...STRONG THUNDERSTORMS ARE ALSO DEVELOPING IN
FAR WEST TEXAS THIS AFTERNOON. ADDITIONAL DEVELOPMENT IN WEST
TEXAS IS EXPECTED THIS AFTERNOON AND EVENING...NEAR THE
DRYLINE...BUT DO NOT EXPECT THIS ACTIVITY TO REACH NORTH TEXAS.
MANY OF THE MODELS...INCLUDING THE HI-RES MODELS...ARE DEVELOPING
A MCS NORTHWEST OF THE REGION LATE TONIGHT. HOWEVER...MOST OF THE
MODELS TRACK THIS SYSTEM TO THE EAST AND KEEP IT WELL NORTH OF THE
RED RIVER. WILL MAINTAIN THE LOW POPS IN THE FAR NORTHWEST AND
NORTHERN COUNTIES OF THE CWA TONIGHT IN CASE THE TRACK OF THIS
SYSTEM CHANGES OR ADDITIONAL DEVELOPMENT OCCURS ALONG ANY OUTFLOW
BOUNDARIES TO THE SOUTH.
SOUTHWEST FLOW ALOFT WILL CONTINUE ACROSS THE REGION FOR THE NEXT
FEW DAYS AND THEN AN UPPER LEVEL RIDGE WILL BUILD IN OVER THE
WEEKEND. THE CAP IS FORECAST TO STRENGTHEN OVER NORTH TEXAS THUS
THE RAIN POTENTIAL LOOKS LOW FOR MOST OF THE NEXT SEVEN DAYS. WITH
SOUTHWEST FLOW ALOFT CONTINUING FOR THE NEXT FEW DAYS...IT IS
POSSIBLE THAT SOME ISOLATED ACTIVITY COULD DEVELOP IN THE
AFTERNOON/EVENING HOURS...BUT CONFIDENCE IS TOO LOW TO MENTION AN
ISOLATED WORDING THE FORECAST. THE EXCEPTION TO THIS COULD BE LATE
THIS WEEK WHEN A DISTURBANCE MOVES ACROSS BAJA CALIFORNIA AND
POSSIBLY INTO NORTH TEXAS. THE MODELS CONTINUE TO STRUGGLE WITH THE
TRACK...TIMING...AND STRENGTH OF THIS FEATURE...THUS WILL CONTINUE
WITH A DRY FORECAST FOR NOW. HOWEVER...SOME OF THE MODELS THINK WE
MAY SEE SOME RAIN ON SATURDAY.
WARM TEMPERATURES ARE EXPECTED TO CONTINUE FOR THE NEXT WEEK.
THURSDAY COULD BE ONE OF THE WARMEST DAYS OF THIS WEEK AND THEN
THE BEGINNING OF NEXT WEEK LOOKS WARM WITH TEMPERATURES
APPROACHING 90 DEGREES OVER MUCH OF NORTH TEXAS. THE LOW LEVEL JET
AFTER TOMORROW WILL BE SLIGHTLY WEAKER...THUS MORNING STRATUS
WILL LIKELY NOT BE AS AGGRESSIVE AS IT TYPICALLY IS THIS TIME OF
YEAR. AFTERNOON WINDS WILL BE BREEZY OVER THE NORTHWEST HALF OF
THE CWA.
82/JLD
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 70 86 69 87 70 / 10 10 10 10 10
WACO, TX 71 88 70 89 69 / 10 10 10 10 10
PARIS, TX 68 84 67 85 67 / 20 10 10 10 10
DENTON, TX 69 85 68 86 68 / 10 10 10 10 10
MCKINNEY, TX 69 85 68 86 68 / 10 10 10 10 10
DALLAS, TX 71 86 70 88 70 / 10 10 10 10 10
TERRELL, TX 69 85 68 85 68 / 10 10 10 10 10
CORSICANA, TX 69 86 68 86 69 / 10 10 10 10 10
TEMPLE, TX 70 85 69 89 68 / 10 10 10 10 10
MINERAL WELLS, TX 67 85 66 87 67 / 10 10 10 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1151 PM CDT SAT APR 28 2012
.AVIATION...
FOR THE 06Z TAFS...TIMING THE ONSET OF MVFR STRATUS CONTINUES TO
BE THE PRIMARY FORECAST CONCERN.
THE ONLY CHANGE FROM THE PREVIOUS TAF ISSUANCE WAS TO BACK UP THE
TIMING OF THE ONSET OF STRATUS BY ONE HOUR FOR ALL AREA TAF SITES.
STRATUS REMAINS LARGELY UNORGANIZED UPSTREAM...HOWEVER A MORE
SOLID DECK OF STRATUS APPEARS TO BE ORGANIZING JUST SOUTH OF
AUSTIN AS OF 05Z. EXPECT THAT STRATUS WILL MOVE NORTH ON THE LOW
LEVEL JET ONCE AGAIN TONIGHT...SO DID NOT REMOVE MVFR CIGS OR
CHANGE THE EXPECTED HEIGHTS OF THE CEILINGS ANY. THE REMAINDER OF
THE FORECAST REMAINS UNCHANGED.
CAVANAUGH
.../PREVIOUS AVIATION DISCUSSION/...
FOR THE 00Z TAFS...TIMING THE ONSET OF MVFR STRATUS IS THE PRIMARY
FORECAST CONCERN THROUGH THE VALID FORECAST PERIOD.
DID NOT MAKE MUCH IN THE WAY OF CHANGES TO PREVIOUS FORECAST.
BACKED UP THE ONSET OF STRATUS OVER METROPLEX AREA TAF SITES BY AN
HOUR BASED ON RUC FORECAST SOUNDINGS. OTHERWISE AGREE THAT STRATUS
WILL LIKELY HOLD ABOVE 2 KFT FOR METROPLEX AREA TAF SITES AND
SHOULD CLIMB 3 KFT BEFORE SCATTERING OUT TOMORROW MORNING. WACO
WILL GET INTO THE STRATUS A BIT EARLIER AND CIGS SHOULD HOLD A FEW
HUNDRED FEET LOWER THAN METROPLEX AREA TAF SITES. CONDITIONS WILL
ALSO LIKELY RETURN TO VFR AN HOUR OR SO LATER THAN METROPLEX AREA
SITES.
ONCE AGAIN THINK THAT THUNDERSTORM ACTIVITY WILL REMAIN WELL OFF
TO THE NORTHWEST OF THE METROPLEX OVER THE NEXT 24 TO 36 HRS AND
HAVE NOT INCLUDED ANY MENTION OF TSTM ACTIVITY IN THE TAFS. THE
SURFACE BOUNDARY NEAR WICHITA FALLS IS ACTUALLY EXPECTED TO
RETREAT TO THE NORTHWEST OVERNIGHT AND AS THIS IS EXPECTED TO PLAY
A KEY ROLE IN TSTM INITIATION...DO NOT THINK THAT ANY TSTM
ACTIVITY WILL BE ABLE TO AFFECT AREA TAF SITES.
CAVANAUGH
&&
.UPDATE...
A FEW THUNDERSTORMS HAVE DEVELOPED NEAR A RETREATING SURFACE
BOUNDARY STRETCHING FROM WEST OF THE CWA INTO OKLAHOMA. THE
STRONGEST STORM IS CURRENTLY LOCATED NEAR ASPERMONT AND IS MOVING
TO THE EAST AROUND 20-25 MPH. CURRENT EXTRAPOLATION WOULD BRING
THIS CELL INTO STEPHENS/YOUNG COUNTY AROUND MIDNIGHT...BUT DO NOT
ANTICIPATE IT HOLDING ITS STRENGTH FOR THE NEXT 3 HOURS AS CIN IS
EXPECTED TO INCREASE. ALSO...DO NOT EXPECT ITS MOVEMENT TO REMAIN
EAST. AS THE STORM WEAKENS...ITS FORWARD MOVEMENT WILL BECOME MORE
NORTHEASTERLY. CURRENT POP CONFIGURATION STILL LOOKS FINE...WITH
20 POPS NORTH OF AN EASTLAND TO DECATUR TO SHERMAN LINE. WILL ONLY
MAKE MINOR ADJUSTMENTS TO THE HOURLY GRIDS.
85/NH
&&
.PREV DISCUSSION... /ISSUED 252 PM CDT SAT APR 28 2012/
A SHORTWAVE ROTATING AROUND THE UPPER LEVEL LOW IN THE NORTHERN
PLAINS IS NOW MOVING INTO THE TEXAS AND OKLAHOMA PANHANDLES.
MEANWHILE A FRONT HAS STALLED JUST NW OF THE CWA BORDER...ALONG A
LINE FROM ABI-SPS-OKC. CIN REMAINS HIGH DUE TO A STRONG INVERSION
NEAR 800MB...BUT WILL BEGIN TO LIFT/ERODE ACROSS THE NW ZONES LATE
THIS AFTERNOON AND EVENING AS FORCING FROM THE SHORTWAVE ARRIVES.
ALTHOUGH CONVERGENCE ALONG THE FRONTAL BOUNDARY IS FAIRLY WEAK ON
THE TEXAS SIDE...EXPECT A FEW STORMS TO DEVELOP BY EARLY EVENING.
STORM MOTION WILL BE GENERALLY TO THE NORTHEAST AND THUS WILL KEEP
THE LOW POPS RESTRICTED TO JUST THE NW ZONES TONIGHT. DEEP LAYER
SHEAR OF 35KT AND SBCAPE OF UP TO 2000 J/KG SUGGESTS STORM MODE
WILL WAFFLE BETWEEN MULTICELL AND BRIEF SUPERCELL. A LOW SEVERE
THREAT IS POSSIBLE IN THE FAR NW ZONES THIS EVENING...WITH HAIL
AND DAMAGING WINDS THE PRIMARY HAZARD. OTHERWISE...SOUTH WINDS
OF 10-20 MPH WILL ENSURE ANOTHER MILD NIGHT ACROSS NORTH TEXAS
WITH LOW STRATUS ARRIVING AFTER MIDNIGHT. MID-HIGH MOISTURE/CLOUDS
WILL ALSO BE ON THE INCREASE FROM THE SOUTHWEST AND WE MAY SEE
SOME RADAR ECHOES FROM VIRGA MOVE ACROSS THE REGION TONIGHT.
MORE ABUNDANT CLOUD COVER TOMORROW WILL HELP KEEP HIGH TEMPS A
COUPLE OF DEGREES COOLER THAN TODAY. ANOTHER SHORTWAVE WILL MOVE
THROUGH THE SOUTHERN PLAINS SUNDAY NIGHT. MOST OF THE CONVECTION
SUNDAY AFTERNOON AND EVENING WILL BE ACROSS OKLAHOMA...BUT SOME
OF THIS ACTIVITY MAY WANDER INTO THE NW ZONES WITH THE AID OF
CONVECTIVE OUTFLOWS. THE CAP WILL REMAIN TOO STRONG OVER THE
REMAINDER OF NORTH TEXAS THROUGH SUNDAY NIGHT FOR A MENTION OF
POPS. HOWEVER...FORCING FROM THE SHORTWAVE MAY LIFT THE CAP JUST
ENOUGH NORTH OF I-20 BY MONDAY MORNING FOR THE NORTHERN HALF OF
THE CWA TO HAVE A LOW CHANCE OF RAIN MONDAY WITH DAY-TIME HEATING.
THE REMAINDER OF THE FORECAST IS RATHER BENIGN AS THE UPPER LEVEL
PATTERN BECOMES STATIC WITH WEAK TROUGHING ACROSS THE NORTHERN
ROCKIES. THIS WILL KEEP A MOIST SOUTHERLY FLOW AT 15 TO 20 MPH IN
PLACE. EXPECT MILD OVERNIGHT LOWS IN THE MID-UPPER 60S WITH LATE
NIGHT AND MORNING LOW CLOUDS. AFTERNOONS WILL FEATURE SUNSHINE AND
HIGHS IN THE MID-UPPER 80S...BUT CAP LOOKS STRONG ENOUGH TO
PRECLUDE MENTIONING ANY RAIN CHANCES. MODELS ARE STILL STRUGGLING
TO RESOLVE UPPER LEVEL FEATURES BY THE END OF THE FORECAST PERIOD.
THE GFS IS NOW AN OUTLIER AS IT SHOWS STRONGER UPPER RIDGING AND A
WEAK FRONT BY SATURDAY. WILL SIDE WITH THE OTHER MODELS AND KEEP
THE WARM/DRY PERSISTENCE TREND IN PLACE.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 67 84 69 86 69 / 10 10 10 20 10
WACO, TX 69 84 69 86 69 / 5 10 10 10 10
PARIS, TX 65 82 66 82 66 / 10 10 10 20 10
DENTON, TX 65 83 67 85 68 / 10 10 20 20 10
MCKINNEY, TX 65 83 67 84 67 / 10 10 10 20 10
DALLAS, TX 68 84 69 85 69 / 10 10 10 20 10
TERRELL, TX 66 83 69 84 68 / 5 10 10 20 10
CORSICANA, TX 67 84 69 85 68 / 5 10 10 10 10
TEMPLE, TX 69 85 69 86 68 / 5 10 10 10 10
MINERAL WELLS, TX 66 83 66 86 67 / 10 20 20 20 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1044 AM CDT SUN APR 29 2012
.UPDATE...
UPPER-LEVEL CLOUDS CONTINUE TO WORK INTO CWA...THOUGH HIGHS SHOULD
STILL REACH NEAR THEIR SEASONAL VALUES DESPITE DAYTIME HEATING BEING
LIMITED BY CIRRUS. INHERITED GRIDS APPEAR TO BE ON TRACK...ONLY
SLIGHTLY ADJUSTED TO ACCOUNT FOR LATEST OBS TRENDS.
MAIN CONCERN IS SAID CLOUDS AND THEIR INFLUENCE ON HIGHS. BUT GIVEN
CURRENT TEMPS...AND HOW MUCH FILTERED SUNSHINE IS COMING THROUGH...NO
SIGNIFICANT CHANGES WERE MADE WITH HIGHS. SHOWERS ARE STILL ANTICIPATED
TO NOT IMPACT THE CWA UNTIL 00Z MONDAY AT THE EARLIEST. LATEST MODEL
GUIDANCE...INCLUDING HI-RES HRRR AND LOCAL WRF...AGREES WITH PREVIOUS
FCST IN REGARD TO TIMING.
&&
.AVIATION/18Z TAFS/...
VFR CONDITIONS EXPECTED INTO THE EARLY EVENING HOURS...BUT THEN
THINGS DETERIORATE TONIGHT. LOOK FOR HIGH CLOUDS AND UNRESTRICTED
VSBYS THROUGH ABOUT 01Z THIS EVENING. THEN AN IMPRESSIVE SURGE OF
MOISTURE WILL HEAD NORTH INTO SOUTHERN WISCONSIN THIS EVENING ON
AN INCREASING LOW LEVEL JET AHEAD OF AN 850MB LOW PRESSURE SYSTEM
MOVING ACROSS IOWA. A SURFACE WARM FRONT WILL ARRIVE LATE TONIGHT
AS WELL. RAIN WILL QUICKLY OVERSPREAD THE AREA THIS EVENING WITH
CIGS DROPPING TO MVFR BY AROUND 05-06Z AND LIKELY TO IFR LEVELS
AFTER 09Z. THERE IS SMALL CHANCE FOR THUNDERSTORMS WITH THIS
EVENT...BUT IT ISN/T THE MAIN CONCERN. THE RAIN SHOULD BE EXITING
EASTERN WISCONSIN BY AROUND 12Z. BUT A BAGGY PRESSURE PATTERN WITH
AN EXITING WARM FRONT TO THE EAST WILL LIKELY PRECLUDE ANY GOOD
SCOURING OF THE LOW CLOUDS UNTIL ABOUT MID DAY ON MONDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE FCST TRENDS...EHT
UPDATE AVIATION...DAVIS
TODAY/TONIGHT AND AVIATION/MARINE...MBK
MONDAY THROUGH SATURDAY...MRC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1223 AM CDT SUN APR 29 2012
.SHORT TERM...TONIGHT THROUGH TUESDAY
315 PM CDT SAT APR 28 2012
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES SUNDAY AFTERNOON
INTO MONDAY...THEN TEMPERATURES AND PRECIPITATION CHANCES TUESDAY.
LATEST MOSAIC RADAR INDICATING FRONTOGENETICAL BAND EXTENDING FROM
LAKE MICHIGAN TO WESTERN MINNESOTA WEAKENING AND SHRINKING...THIS
IS IN AGREEMENT WITH THE 28.18Z RUC 700-600MB FN VECTOR CONVERGENCE
WEAKENING THE FRONTOGENETICAL BAND THIS AFTERNOON INTO THIS
EVENING.
THE 28.12Z GFS/NAM ARE IN PRETTY GOOD AGREEMENT IN LIFTING UPPER
LEVEL LOW OVER THE NORTHERN PLAINS NORTHWARD INTO CANADA SUNDAY
NIGHT AND DEVELOPING SOUTHWESTERLY FLOW ALOFT MONDAY NIGHT INTO
TUESDAY. DPROG/DT OF THE 28.12Z GFS AND NAM SHOW SHORTWAVE TROUGH
WRAPPING AROUND THE UPPER LEVEL LOW INTO THE AREA FASTER THE LAST
SEVERAL RUNS. CONFIDENCE IS INCREASING PRECIPITATION WILL
OVERSPREAD THE REGION SUNDAY AFTERNOON. NO SIGNIFICANT DIFFERENCES
NOTED BETWEEN THE 28.12Z DETERMINISTIC MODELS.
TONIGHT INTO MONDAY...FRONTOGENETICAL BAND OVER OVER WESTERN
AND CENTRAL WISCONSIN WILL CONTINUE TO WEAKEN THIS EVENING. THEN...
WEAK RIDGE BUILDS INTO EASTERN WISCONSIN AFTER MIDNIGHT TONIGHT
INTO SUNDAY MORNING. DRY WEATHER CONDITIONS ARE EXPECTED AFTER 06Z
TO AROUND 18Z SUNDAY. THE 28.12Z GFS/NAM/ECMWF ARE MORE PROGRESSIVE
WITH SHORTWAVE ROTATING AROUND UPPER LEVEL LOW INTO THE FORECAST
AREA. THE 28.12Z GFS/NAM SHOW DECENT ISENTROPIC LIFT AT 305K
SURFACE...MOISTURE TRANSPORT AND CONVERGENCE AT 925-850MB LAYER...
IN ASSOCIATION WITH THE SHORTWAVE TROUGH. HAVE INCREASED
PRECIPITATION CHANCES FROM 18Z SUNDAY TO 12Z MONDAY. THE 28.12Z
GFS/NAM SHOW AROUND 100 J/KG 0-6KM MOST UNSTABLE CAPE ACROSS
NORTHEAST IOWA AND SOUTHWEST WISCONSIN...INTRODUCED ISOLATED THUNDER
ACROSS NORTHEAST IOWA AND SOUTHWEST WISCONSIN AFTER 18Z SUNDAY. WITH
THE MODELS INDICATING A FASTER SOLUTION WITH THE SHORTWAVE TROUGH...
EXPECT MUCH OF THE PRECIPITATION TO BE EAST OF THE FORECAST AREA BY
18Z MONDAY.
NEXT FORECAST CONCERN IS THE 28.12Z GFS/NAM DEVELOPING SOUTHWESTERLY
FLOW ALOFT OVER ROCKY MOUNTAINS AND UPPER MIDWEST MONDAY NIGHT INTO
TUESDAY. THE DETERMINISTIC MODELS ARE ADVECTING WARMER AIR INTO THE
FORECAST AREA WITH 850MB TEMPERATURES RISING TO PLUS 12 TO PLUS 15
DEGREES CELSIUS BY 00Z WEDNESDAY. HIGH TEMPERATURES TUESDAY WILL BE
MAINLY IN THE LOWER TO MIDDLE 70S...WITH THE POSSIBILITY OF 80
DEGREES OVER NORTHEAST IOWA OR SOUTHEAST MINNESOTA. THE 28.12Z
GFS/NAM DO SHOW MOISTURE TRANSPORT AND ISENTROPIC LIFT AT 305K
SURFACE...MAINLY AFTER 18Z TUESDAY ACROSS THE FORECAST AREA. THE
28.12Z GFS/NAM INDICATE DECENT 0-3KM SHEAR AND INSTABILITY DURING
THE DAY TUESDAY. HOWEVER...THE BEST LIFT AND CONVERGENCE AT THIS TIME
APPEARS TO BE NORTHWEST AND SOUTHWEST OF FORECAST AREA AND HAVE KEPT
SMALL CHANCES OF PRECIPITATION ACROSS FORECAST AREA.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
315 PM CDT SAT APR 28 2012
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES THROUGH THE
PERIOD AND UNSEASONABLY WARM TEMPERATURES THROUGH THURSDAY. THE
28.12Z GFS/GEM/ECMWF CONTINUE TO DEVELOP WEST TO SOUTHWESTERLY FLOW
ALOFT AND CONTINUE TO HAVE DIFFERENCES IN TIMING OF SHORTWAVE
TROUGHS EMBEDDED IN THE WEST TO SOUTHWESTERLY FLOW ALOFT THROUGH
THE PERIOD. CONFIDENCE IN TIMING OF THE INDIVIDUAL SHORTWAVE TROUGHS
MOVING INTO THE UPPER GREAT LAKES REGION IS LOW...HOWEVER
CONFIDENCE IS INCREASING AN ACTIVE WEATHER PATTERN WILL SET UP OVER
THE UPPER GREAT LAKES AND UPPER MIDWEST REGION MIDDLE OF NEXT WEEK.
THE DETERMINISTIC 28.12Z GFS/GEM/ECMWF SHOW WARM AIR ADVECTING INTO
THE FORECAST AREA TUESDAY NIGHT AND CONTINUING INTO THURSDAY...WITH
850MB TEMPERATURES RANGING FROM PLUS TWELVE DEGREES CELSIUS TO
PLUS FIFTEEN DEGREES CELSIUS AND THE 28.00Z GEFS INDICATING
STANDARD ANOMALIES OF 1-1.5. EXPECT TEMPERATURES TO BE
WELL ABOVE NORMAL THROUGH THE MIDDLE OF NEXT WEEK ACROSS FORECAST
AREA.
&&
.AVIATION...THROUGH 06Z MONDAY
1223 AM CDT SUN APR 29 2012
LOW STRATUS WILL PRODUCE IFR CONDITIONS AT KRST THROUGH 10Z THIS
MORNING WITH CLOUD BASES IN THE 700 TO 900 FT RANGE. IN
ADDITION...AREAS OF BR WILL REDUCE VISIBILITIES TO AROUND 4 SM AT
TIMES. PLAN ON VFR CONDITIONS AT KSLE TODAY WITH CLOUD BASES
AROUND 4 KFT EARLY THIS MORNING...IMPROVING TO AROUND 10 KFT BY
THE LATE MORNING HOURS. PLAN ON IMPROVING CEILINGS AT KRST AFTER
10Z WITH VFR CONDITIONS EXPECTED BY 15Z. THE NEXT SYSTEM LOOKS TO
PUSH INTO THE REGION LATE THIS AFTERNOON INTO THIS EVENING FROM
THE CENTRAL PLAINS...BRINGING A CHANCE OF SHOWERS TO THE TAF
SITES. IN ADDITION...CEILINGS WILL LOWER THIS EVENING WITH
MVFR/IFR CEILINGS EXPECTED BY LATE TONIGHT. WINDS WILL BE OUT OF
THE EAST/SOUTHEAST TODAY AT 7 TO 13 KTS...POSSIBLY GUSTING TO
AROUND 21 KTS THIS AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
315 PM CDT SAT APR 28 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM....DTJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
330 AM CDT TUE MAY 1 2012
.SYNOPSIS...
ANALYSIS AND NOWCAST TOOLS INDICATE VIGOROUS SHORT WAVE IN WESTERN
MISSOURI TO OCCLUDE AND MOVE ACROSS SE 1/2 TO 2/3 PORTIONS OF THE
AREA TODAY. THIS DYNAMIC SYSTEM IS POORLY HANDLED BY MOST SOLUTIONS
WITH HI-RES ECMWF AND LATEST 06Z RUC TRENDING CORRECTLY. AREA
TEMPERATURES HAVE CRASHED AT 2 AM INTO THE 40S OVER THE REGION WITH
39F AT FREEPORT. THIS BAROCLINICITY WILL ENHANCE MISSOURI SYSTEM FOR
LOTS OF CLOUDS AND RAIN SHOWERS AND SOME EMBEDDED THUNDER.
COMMENT...INITIALIZATION AND VERIFICATION COMBINED WITH RUN TO RUN
CONTINUITY SUPPORTS STRONGLY USE OF HI-RES ECMWF NEXT 24 HOURS.
BESIDES RESULTING IN MAJOR CHANGES TO FORECAST OF HIGHER POPS (MUCH)
AND LOWER TEMPERATURES (MUCH). THIS PUTS AREA IN PRECARIOUS POSITION
FOR STRONG CONVECTION TONIGHT WITH LOW LEVEL JET SUGGESTING
TRAINING OF STORMS WITH SOME SEVERE AND POSSIBLY HEAVY TO LOCALLY
VERY HEAVY RAINFALL.
&&
.SHORT TERM...TODAY AND TONIGHT...
TODAY...LOWERED MAX TEMPERATURES BY 5+ DEGREES ACROSS AREA WITH
NORTHERN PORTIONS POSSIBLY NOT REACHING 70F DUE TO CLOUDS AND
PRECIPITATION. POPS HAVE RAISED TO HIGH LIKELY SOUTH AND CHANCE NORTH
BUT TRENDS SUGGEST GOING EVEN HIGHER. WIDESPREAD .1 TO 25+ INCHES
SUGGESTED SOUTH OF I-80 WITH LOCALLY UP TO .5 INCHES POSSIBLE
SUGGESTED ALONG AND SOUTH OF HIGHWAY 34. THE STRONG BAROCLINIC
GRADIENT MAY ALSO RESULT IN LOW CLOUDS INTO THE PM HOURS. IF SYSTEM
STRONG ENOUGH...COULD SEE STRONGER WINDS WITH GUSTS OVER 30+ MPH IN
MODEST INTERNAL GRAVITY WAVES WITH LATENT HEAT RELEASE.
TONIGHT...WARM FRONT TO MOVE NORTH TONIGHT WITH UPPER DIFFLUENCE AND
LOW LEVEL JET SUPPORTING EVENING AND OVERNIGHT CONVECTION TO
BLOSSOM ACROSS AREA BY MIDNIGHT NORTH OF HIGHWAY 34. LOCAL HEAVY
RAIN TOOLS SUGGESTS TRAINING OF STORMS POSSIBLE WITH PW/S 1.25 TO
1.5+ INCHES WITH LOW LEVEL JET OF 40-45 KTS FOR AREAS OF 2 TO
POSSIBLY NEAR 3 INCHES FOR LATER SHIFTS. HAVE KEPT POPS LOWER DUE
TO CONCERN OF WHERE STORMS FIRE BUT SOME SEVERE STORMS AND LOCALLY
HEAVY RAINFALL ARE FAVORED ATTM. LOCAL TECHNIQUES SUGGEST LARGE
HAIL UP TO GOLF BALLS OR 1.75 INCHES IN DIAMETER WITH STRAIGHT LINE
WINDS OF 50+ MPH TO NEAR SEVERE THE SECONDARY RISK. CHANCES OF
STORMS AND HEAVY RAIN DECREASE RAPIDLY SOUTH OF HIGHWAY 34. MINS
SUGGESTED TO BE IN THE MIDDLE TO UPPER 60S. NICHOLS
.LONG TERM...WEDNESDAY THROUGH MONDAY...
WET AND UNSETTLED WEATHER WILL PREVAIL OVER MUCH OF THE AREA
THROUGHOUT. CYCLONIC SW UPPER LEVEL FLOW AND NEARLY PARALLEL
STATIONARY FRONT SETTING UP FROM NEB NORTHEAST THROUGH MN AND WI
WILL PLACE THE LOCAL FORECAST AREA INTO THE MUCH WARMER...HUMID GULF
AIRMASS THAT HAS BEEN POISED TO THE SOUTH ACROSS THE SOUTHERN PLAINS
AND LOWER MS VALLEY THE PAST SEVERAL DAYS...THROUGH AT LEAST FRIDAY.
PERIODIC MID LEVEL SHORTWAVES ARE EXPECTED TO TRIGGER
THUNDERSTORM COMPLEXES ALONG THIS BOUNDARY TO THE NORTH...WHICH MAY
MIGRATE SOUTHEAST INTO AT LEAST THE NORTHERN HALF OF THE FORECAST
AREA. RESULTING OUTFLOW BOUNDARIES MAY THEN RESULT IN A SECONDARY
FRONT FURTHER SETTING UP FURTHER SOUTH OVER THE LOCAL FORECAST
AREA...THAT COULD LEAD TO HEAVY RAINFALL...AS ADVERTISED BY THE LAST
COUPLE ECMWF RUNS. BESIDES THE THREAT OF HEAVY RAINFALL...WILL ALSO
HAVE THE POTENTIAL FOR SEVERAL ROUNDS OF SEVERE WEATHER OVER
PORTIONS OF THE FORECAST AREA DUE TO THE VERY MOIST...UNSTABLE
AIRMASS AND PERIODS OF WEAK UPPER FORCING THAT ENHANCE DEEP SHEAR.
WED INTO WED NIGHT...WILL KEEP A TREND OF HIGHER CHANCE POPS NORTH
AND SLIGHT TO LOW CHANCE POPS IN THE SOUTH WHERE WARMER TEMPERATURES
ALOFT MAY EFFECTIVELY CAP CONVECTION THROUGH MUCH OF THE DAY...ONCE
THE NOCTURNAL CONVECTION DISSIPATES. SURFACE TEMPERATURES SHOULD
EASILY REACH INTO THE UPPER 70S TO LOWER 80S...WHILE DEWPOINTS CLIMB
INTO THE 60S. HAVE KEPT TEMPERATURES TRENDED ON THE CONSERVATIVE
SIDE BASED ON LOW CONFIDENCE THAT CLOUD COVER WILL CLEAR. BUILDING
INSTABILITY...ESPECIALLY IF SKIES DO CLEAR...WOULD PUSH SURFACE
BASED CAPES ABOVE 2000 J/KG. THIS...ALONG WITH A REDEVELOPING LOW
LEVEL JET BY OVERNIGHT AND A POSSIBLE SHORTWAVE BRUSHING THE
NW...WILL CONTINUE A RISK FOR SEVERE STORMS. SPC HAS A DAY 2 SLIGHT
RISK OVER MOST OF THE AREA...BUT THIS POTENTIAL LOOKS TO BE HIGHER
DURING THE LATTER HALF OF THE PERIOD...FROM LATE WED AFTERNOON INTO
LATE EVENING WITH THE AID OF THE AFOREMENTIONED LOW LEVEL JET AND
UPPER FORCING.
THURSDAY AND FRIDAY...WILL HAVE A CONTINUED POTENTIAL FOR HEAVY RAIN
AND POSSIBLE SEVERE STORMS...THAT WILL BE GREATLY DEPENDENT ON THE
FOCUS OF THE LOW LEVEL JET...WHICH THE ECMWF HAS OVER CENTRAL AND
EASTERN IA. THIS COULD EASILY LEAD TO 48 HOUR RAINFALL TOTALS WELL
OVER 2 INCHES. CONFIDENCE IS NOT HIGH ON DETAILS THIS FAR
OUT...ESPECIALLY GIVEN THE UNKNOWNS WITH CONVECTIVE TRENDS AND MCS
INTERACTIONS. FOR NOW WILL KEEP CHANCE POPS GOING WITH LOW QPF THAT
WOULD NEED TO BE INCREASED IF FORECAST CONFIDENCE INCREASES.
WILL HAVE TO HAVE SOME BREAKS IN THE ACTIVITY TO ALLOW FORECAST
HIGHS IN THE 80S TO BE ACHIEVED. HIGH DEWPOINTS WILL HOLD MINS IN
THE 60S.
FORECAST CONFIDENCE DIMINISHES CONSIDERABLY OVER THE WEEKEND INTO
EARLY NEXT WEEK...AS MEDIUM RANGE MODELS DIVERGE IN THE TIMING
AND PLACEMENT OF A RIDGE BUILDING ALOFT. THIS AFFECTS THE PLACEMENT
OF THE ASSOCIATED SURFACE HIGH...SYNOPTIC BOUNDARY...AND ASSOCIATED
FOCUS FOR RAIN AND THUNDERSTORMS. LATEST FORECAST BASED ON MODEL
BLEND HAS HIGHS COOLING FROM THE 80S SATURDAY...TO 60S BY MONDAY
WITH PRECIPITATION LIKELY BECOMING MORE IN THE FORM OF LIGHT RAIN BY
SUNDAY AND MONDAY WITH MUCH MORE LIMITED POTENTIAL FOR
THUNDERSTORMS.
SHEETS
&&
.AVIATION...
GENERALLY VFR CONDITIONS THROUGH 15Z WITH PATCHY SHALLOW FOG UNTIL
12Z. CLOUDS TO INCREASE WITH SHRA AND ISOLATED TSRA LIKELY AT BRL AND
MLI BY 16Z WITH PERIODS OF MVFR CONDITIONS SUGGESTED WITH CLOUD BASES
OF 1-3K AGL BETWEEN 17-22Z IN LIGHT TO MODERATE RAIN AND POSSIBLY
EMBEDDED THUNDERSTORM. SE WINDS OF 10 TO 20+ MPH BY AFTERNOON ALL
TERMINALS. PARTIAL CLEARING WITH VFR CONDITIONS RETURNING BY 21Z.
TONIGHT...CHANCE FOR NOCTURNAL STORMS TO IMPACT CID AND DBQ TERMINALS
AFTER 06Z AS WARM FRONTAL BOUNDARY BECOMES ACTIVE. NICHOLS
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
NICHOLS/SHEETS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
145 AM EDT TUE MAY 1 2012
.SYNOPSIS...
A WARM FRONT WILL LIFT ACROSS NEW YORK FROM THE OHIO VALLEY THIS EVENING
WITH SOME SHOWERS AND AN ISOLATED THUNDERSTORM OR TWO. A COLD
FRONT WILL CROSS THE REGION LATE TONIGHT WITH ANOTHER ROUND OF
SHOWERS. CONDITIONS WILL THEN BECOME NOTABLY WARMER BUT UNSETTLED
ACROSS THE REGION TUESDAY THROUGH THE REMAINDER OF THE WEEK AS
TEMPERATURES WILL CLIMB WELL ABOVE NORMAL.
&&
.NEAR TERM /THROUGH TODAY/...
A BROAD AREA OF LOW PRESSURE WILL LIFT TO THE NORTHEAST ACROSS
WESTERN NEW YORK OVERNIGHT. SHOWERS HAVE SPREAD INTO WESTERN NEW
YORK LATE THIS EVENING...WITH THESE SHOWERS FORECAST TO CONTINUE
TO MOVE ACROSS THE REGION OVERNIGHT. THE HRRR IN PARTICULAR HAS BEEN
QUITE CONSISTENT IN BRINGING SHOWERS ACROSS WESTERN NEW YORK
TONIGHT THROUGH 10Z...WITH RUNS OF THE NAM/RGEM ALSO SIMILAR BUT
PERHAPS A TAD SLOW. RADAR TRENDS ARE IN GENERAL SUPPORT OF THIS
CONSENSUS...AND ARE WELL CAPTURED BY ALL OF THESE MODELS...THE
HRRR IN PARTICULAR. ALSO...EXPECT SOME LIGHTNING WILL REACH
WESTERN NEW YORK WITH THIS AS WELL...THOUGH SURFACE BASED
CONVECTION SHOULD REMAIN TO THE SOUTH...WITH ELEVATED CONVECTION
ACROSS WESTERN NEW YORK SUPPORTING A MINIMAL (TO NIL) SEVERE
WEATHER THREAT. THIS SAID...EXPECT SHOWERS TO BRING A HALF INCH OR
SO OF RAIN TO SOUTHERN PORTIONS OF THE CWA...WITH LOCALLY HIGHER
AMOUNTS POSSIBLE IN THUNDERSTORMS. THE BEST CHANCE FOR
THUNDERSTORMS AND HIGHER QPF IN THE INCH RANGE APPEAR TO BE ACROSS
WESTERN PORTIONS OF THE SOUTHERN TIER...FOLLOWING BOTH HRRR
FORECASTS AND RADAR TRENDS.
OTHERWISE...TEMPERATURES WILL REMAIN MILD WITH WARMER AIR
SHIFTING ACROSS THE REGION WITHIN THE LOW PRESSURE SYSTEMS WARM
SECTOR. TEMPS WILL NOT FALL MUCH OVERNIGHT AND MAY IN FACT REMAIN
STEADY OR RISE. SOUTH I-90 WHERE WINDS HAVE GONE TO THE SE BEHIND
THE WARM FRONT...HEDGE ON THE WARM SIDE OF MOS GUIDANCE...WITH
STEADY TEMPERATURES IN THE 50S LIKELY OVERNIGHT.
TUESDAY...FRONT MAY STILL BE PRESSING EAST ACROSS CENTRAL AND
NORTHERN NEW YORK TUESDAY MORNING WITH CHANCES FOR SHOWERS. ALL
AREAS SHOULD BE DRY BY THE AFTERNOON WITH A WEAK HIGH PRESSURE
BUILDING IN BEHIND THE FRONT. MOST AREAS WILL TURN OUT PARTLY TO
MOSTLY SUNNY BY AFTERNOON. HIGHS LOOK TO REACH INTO THE LOW 60S
ESPECIALLY ACROSS WESTERN NEW YORK WHERE THE SUN WILL BREAK OUT
EARLIER THAN CENTRAL AND NORTHERN NY.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
WE WILL SEE A QUIET START TO THE PERIOD AS WESTERN AND CENTRAL NEW
YORK WILL BE FALLING UNDER THE INFLUENCE OF A BROAD UPPER LEVEL
RIDGE UPSTREAM. SUBSIDENCE OVER THE REGION SHOULD ALLOW FOR MOSTLY
CLEAR SKIES. THIS COMBINED WITH LIGHT WINDS SHOULD ALLOW FOR
TEMPERATURES TO DROP INTO THE UPPER 40S WITH MID 40S IN THE USUAL
COOL SPOTS OF THE SOUTHERN/TIER AND NORTH COUNTRY.
WEDNESDAY WILL FEATURE THE BEGINNING OF THE PRONOUNCED WARM-UP THAT
WILL BE AFFECTING THE REGION THROUGH THE REST OF THE WEEK. THE BROAD
UPPER LEVEL RIDGE WILL SETTLE OVER THE EASTERN UNITED STATES WHILE
RETURN FLOW AROUND A STRONG SURFACE HIGH ANCHORED OFF THE SOUTHEAST
U.S. COAST WILL PUMP INCREASINGLY WARM AND MOIST AIR NORTHWARDS
ACROSS THE OHIO VALLEY AND INTO THE GREAT LAKES REGION. THIS WILL
RESULT IN TEMPERATURES THAT WILL RISE WELL INTO THE 70S WEDNESDAY
AND THURSDAY WITH SOME AREAS POSSIBLY BREACHING 80 ON THURSDAY. IN
ADDITION TO THE WARMTH...IT WILL START TO FEEL MUGGY AS WELL AS
SURFACE DEW POINTS WILL ALSO RISE INTO 50S WEDNESDAY AND POSSIBLY LOW
60S THURSDAY AS THE RICH GULF MOISTURE SURGES NORTHWARDS.
WITH THE WARM AND MOIST AIR ADVECTING NORTH INTO THE REGION...WE
INTRODUCE THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS. THE GREATEST
POTENTIAL FOR CONVECTION ON WEDNESDAY WILL BE FOUND ACROSS
FAR WESTERN NEW YORK DURING LATE AFTERNOON AS THE LEADING EDGE OF A
THETA-E RIDGE SLIDES INTO THE NIAGARA FRONTIER. THE THREAT FOR
CONVECTION CONTINUES INTO WEDNESDAY NIGHT AS MODELS INDICATE ML CAPE
VALUES OF AROUND 400 J/KG WEST OF THE GENESEE VALLEY.
CONDITIONS THURSDAY SHOULD BE RIPE FOR SHOWERS AND THUNDERSTORMS AS
WE WILL REMAIN IN A VERY MOIST AIRMASS...HOWEVER WITH LIGHT FLOW AND
A LACK OF A CLEAR TRIGGER SUCH AS A SHORTWAVE...AM NOT EXPECTING
ORGANIZED OR SEVERE CONVECTION. HOWEVER MAY SEE WIDESPREAD
LAKE-BREEZE INDUCED SHOWERS/THUNDERSTORMS...PARTICULARLY INT HE
AFTERNOON/EVENING HOURS. THE FLY IN THE OINTMENT MAY BE WEAK
MID-LEVEL LAPSE RATES THAT MAY PUT A LID ON CONVECTION FROM BREAKING
OUT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
EXPECT MUCH OF THE SAME ON FRIDAY AS THE VERY WARM/MOIST AND
UNSTABLE AIRMASS LINGERS OVER THE REGION WITH HIGHS IN THE 70S AND
AT LEAST A CHANCE OF SHOWERS AND THUNDERSTORMS. THE FORECAST BECOMES
MURKIER BY THE WEEKEND WITH THE MODELS AT ODDS OVER THE
LOCATION/TIMING OF A COLD FRONT SWEEPING SOUTH OUT OF CANADA. THE
GFS PUSHES THE FRONT ACROSS THE FORECAST AREA SATURDAY...A PROSPECT
THAT WOULD RESULT IN A MUCH COOLER/DRIER WEEKEND THAN CURRENTLY
FORECAST. THE ECMWF...ON THE OTHER HAND...PUSHES A MUCH WEAKER
FRONT ACROSS THE REGION LATE ON SUNDAY. GIVEN THESE
DIFFERENCES...WILL OPT FOR A FORECAST THAT LEANS MORE TOWARDS THE
ECMWF/PERSISTENCE WITH HIGHS IN THE LOW 70S...LOWS IN THE 50S...AND
CHANCE POPS.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
A NEARLY SOLID BAND OF RAIN WILL WORK ITS WAY ACROSS THE REGION
DURING THE OVERNIGHT HOURS...EXITING THE EASTERN EDGE OF THE
FORECAST AREA AFTER 08Z-10Z. WILL SEE A DROP IN CEILINGS ALONG THE
TRAILING EDGE OF THE PRECIP SHIELD WITH VFR/MVFR CIGS FALLING TO IFR
AVERAGING 800FT. THIS TRAILING CLOUD WILL LIFT SOMEWHAT THROUGH THE
DAY WITH MVFR CIGS MID-LATE MORNING...THEN BREAKS IN THE CLOUDINESS
LATE IN THE DAY LEADING TO CLEARING.
OUTLOOK...
TUESDAY NIGHT...VFR.
WEDNESDAY THROUGH SATURDAY...VFR/MVFR IN SHOWERS.
&&
.MARINE...
WINDS AND WAVES WILL REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA
DURING THIS PERIOD...ALTHOUGH MORE ACTIVE WEATHER CAN BE EXPECTED.
A WARM FRONT IS LIFTING ACROSS THE LOWER GREAT LAKES FROM THE OHIO VALLEY
TODAY. THIS WILL PRODUCE GENTLE TO OCCASIONALLY MODERATE EASTERLIES
ON LAKES ERIE AND ONTARIO...THEN AS THE WARM FRONT AND ITS SHOWERS
MOVE THROUGH THIS AFTERNOON AND EVENING WINDS WILL BECOME MORE
SOUTHEASTERLY. OVERNIGHT A SURFACE LOW WILL SHIFT EAST ACROSS LAKE ONTARIO
WITH WINDS SHIFTING TO SOUTHWEST BY TUESDAY MORNING. EXPECT LIGHT
WINDS AND NEGLIGIBLE WAVES THROUGH TUESDAY NIGHT.
&&
.CLIMATE...
THIS CHILLY SUNDAY MORNING SAW BUFFALO SET A NEW RECORD LOW
TEMPERATURE WITH THE 28 DEGREE READING BREAKING THE OLD RECORD OF
29. THIS IS THE FIRST TIME A RECORD LOW MINIMUM TEMPERATURE HAS
BEEN SET AT THE BUFFALO AIRPORT SINCE MARCH 6 2007.
ROCHESTER NEW YORK ALSO TIED A RECORD LOW THIS MORNING...THE 27
DEGREES TIED THE RECORD LOW VALUE. THIS IS THE FIRST TIME A RECORD
LOW MINIMUM WAS EITHER SET OR TIED AT ROCHESTER SINCE JULY 14 2009.
BUFFALO AND ROCHESTER WILL ALSO HAVE POTENTIAL FOR THEIR FIRST BELOW
NORMAL TEMPERATURE MONTH SINCE MARCH 2011. BOTH BUFFALO AND
ROCHESTER WITH HELP OF THE LAST 10 DAYS OF APRIL BELOW NORMAL MAY
JUST END FINISHING UP A FEW TENTHS OF A DEGREE BELOW NORMAL FOR
APRIL. FINAL STATISTICS WILL BE CALCULATED AFTER THE MONTH
FINISHES.
APRIL`S MONTHLY TEMPERATURE DEPARTURE IS A DRASTIC DIFFERENCE FROM
MARCH 2012 WHEN BOTH CITIES HAD A SIGNIFICANTLY ABOVE NORMAL
TEMPERATURE DEPARTURE. ONLY ONCE IN RECORDED HISTORY HAS THERE BEEN
A COOLER APRIL THAN MARCH AND THAT OCCURRED FOR BUFFALO BACK IN 1946.
THERE IS GOOD POTENTIAL FOR BOTH CITIES TO HAVE A COOLER APRIL
THAN MARCH IN 2012. THROUGH THE 28TH OF APRIL BUFFALO`S AVERAGE
APRIL TEMPERATURE IS 2.1 DEGREES COOLER THAN THE AVERAGE
TEMPERATURE RECORDED IN MARCH 2012. FOR ROCHESTER...WHICH HAS BEEN
SLIGHTLY WARMER THIS MONTH THROUGH THE SAME TIME SPAN...APRIL 2012
HAS BEEN 1.2 DEGREES COOLER THAN MARCH 2012.
BELOW ARE THE YEARS AND TOP FIVE LOWEST SPREADS BETWEEN APRIL
AVERAGE TEMPERATURE AND MARCH AVERAGE TEMPERATURE.
BUFFALO
YEAR APRIL AVG TEMPERATURE MINUS MARCH AVG TEMPERATURE
1946 -0.1
1898 2.3
1907 2.9
1903 3.0
1920 3.8
ROCHESTER
YEAR APRIL AVG TEMPERATURE MINUS MARCH AVG TEMPERATURE
1898 0.8
1946 1.2
1907 2.8
1903 3.0
1995 3.1
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...APFFEL/SMITH
SHORT TERM...WOOD
LONG TERM...WOOD
AVIATION...WCH
MARINE...APFFEL/SMITH/WOOD
CLIMATE...THOMAS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
432 AM EDT TUE MAY 1 2012
.SYNOPSIS...
A WARM FRONT WILL MOVE NORTHEAST THROUGH THE REGION TODAY...BRINGING
A CHANCE OF SHOWERS AND THUNDERSTORMS. PRECIPITATION WILL CONTINUE
TO BE POSSIBLE THROUGH WEDNESDAY...BEFORE HIGH PRESSURE BUILDS IN ON
THURSDAY AND PROVIDES VERY WARM TEMPERATURES WITH DRY CONDITIONS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A BOUNDARY IS CURRENTLY RESIDING JUST SOUTH OF THE FORECAST
AREA...ALTHOUGH IT IS NOT TERRIBLY EASY TO PICK UP ON SURFACE
OBSERVATIONS. THE FLOW IS SLIGHTLY MORE SOUTHERLY SOUTH OF THE
CWA...BUT THE FEATURE IS PERHAPS EASIEST TO PICK OUT ON MODEL
1000MB-500MB RH FIELDS...WHERE THERE IS A SHARP CONTRAST WITH THE
DRIER HIGH PRESSURE OVER THE SOUTHERN GREAT LAKES AND NORTHERN
OHIO VALLEY.
A DRY FORECAST WILL BEGIN THE PERIOD...WITH ACTIVITY ASSOCIATED
WITH THIS FRONT RATHER SCATTERED AND ALL WELL SOUTH OF THE REGION.
HOWEVER...THE BOUNDARY WILL PROGRESS NORTH INTO THE REGION AS A
WARM FRONT...AND ACTIVITY TO THE WEST AND SOUTHWEST WILL BEGIN TO
AFFECT THE AREA BY AFTERNOON. EVIDENCE OF THIS IS VISIBLE WITH THE
CLUSTER OF STORMS OVER NORTHWESTERN TENNESSEE...WHICH HAS SOMEWHAT
OF A NORTHWARD COMPONENT TO ITS MOTION. THE HRRR DOES SHOW THIS
CLUSTER...BUT ITS PLACEMENT AND TIMING ARE NOT TOTALLY CORRECT.
OVERALL THE POP FORECAST HAS NOT CHANGED TOO MUCH FROM THE
PREVIOUS GRIDS...WITH A SLIGHTLY SLOWER ONSET OF THE HIGHER CHANCE
POPS UNTIL LATER IN THE DAY...BUT MAINTAINING A LOW CHANCE /
SLIGHT CHANCE EARLIER IN THE DAY AS THE FRONT MOVES NORTH. THE
BEST CHANCES FOR PRECIPITATION APPEAR TO COME DURING THE EVENING
(DETAILED BELOW IN THE SHORT TERM SECTION).
THE MAX TEMP FORECAST IS SLIGHTLY CONVOLUTED TODAY...GIVEN THE
CLOUDS AND PRECIPITATION THAT WILL AFFECT THE WHOLE AREA...BUT
ESPECIALLY THE SOUTH AND SOUTHWEST DURING THE DAY TIME HOURS. WITH
THE POSSIBILITY OF MORE SUN IN THE NORTH AND NORTHEAST...THIS MAY
OFFSET THE TYPICAL TEMPERATURE DISTRIBUTION TO RESULT IN SIMILAR
HIGHS ACROSS THE WHOLE CWA TODAY. THE CLOUDS AND EVENTUAL
PRECIPITATION SHOULD BE ENOUGH TO HOLD THINGS IN THE 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
BY LATE AFTERNOON AND INTO THE EVENING...ATTENTION WILL BE TURNED
TO CONVECTION FIRING ON THE ADVANCING WARM FRONT...AS WELL AS
ACTIVITY MOVING IN FROM THE WEST (A PARTIAL DESCENDANT OF THE
CURRENT ACTIVITY IN MISSOURI AND OKLAHOMA). A SHORTWAVE WILL MOVE
INTO THE AREA AND INTERACT WITH AN AIRMASS THAT SHOULD BE
DESTABILIZING TO SOME EXTENT. MIXED LAYER CAPE VALUES OF AROUND
1000 J/KG WILL BE POSSIBLE IN THE SOUTH...WHERE MID LEVEL LAPSE
RATES ARE SLIGHTLY STEEPER AND BOUNDARY LAYER MOISTURE WILL BE
INCREASING. LIFT PROVIDED BY THE SHORTWAVE AND SOME MODEST (THOUGH
NOT BY ANY MEANS INTENSE) CONVERGENCE ON A LOW LEVEL JET WILL
ALLOW FOR STORM DEVELOPMENT. SHEAR IS NOT ESPECIALLY STRONG...BUT
0-6KM BULK SHEAR OF 40 KNOTS WILL ALLOW FOR SOME ORGANIZATION. THE
SEVERE THREAT APPEARS GREATEST IN THE SOUTH...WHERE GREATER
INSTABILITY WILL BE MORE LIKELY. HOWEVER...THE PRESENCE OF SAID
INSTABILITY MAY BE DIMINISHED IF RAIN OCCURS AHEAD OF THE MORE
INTENSE FORCING.
BEYOND THE PASSAGE OF THE SYSTEM THIS EVENING...THE CONVECTIVE
FORECAST BECOMES RATHER DIFFICULT IN TERMS OF SPECIFIC TIMING AND
PLACEMENT. SMEARY MODEL QPF BEHIND THE TUESDAY NIGHT SYSTEM IS
TOUGH TO PLACE WITH REGARDS TO FORCING SIGNALS...ESPECIALLY AS MID
LEVEL RIDGING CONTINUES TO BUILD INTO THE AREA DURING THIS TIME
FRAME. WILL KEEP POPS RATHER LIMITED ON WEDNESDAY...BEFORE GOING
DRY BY WEDNESDAY AFTERNOON IN THE SOUTHWEST AND WEDNESDAY NIGHT
ELSEWHERE. BY THIS POINT...MOST OF THE MODELS ARE DEPICTING
FORCING WELL NORTH OF THE CWA AS THE WARM SECTOR ESTABLISHES
ITSELF OVER THE OHIO VALLEY. ANOTHER WRENCH IN THE SOLUTION
INVOLVES THE POSSIBILITY OF SOME OF THE ACTIVITY OVER MICHIGAN
TURNING SOUTH AND PUNCHING THROUGH THE RIDGE INTO CENTRAL OHIO ON
WEDNESDAY NIGHT. THOUGH IT IS NOT AN IMPOSSIBILITY...IT SEEMS LIKE
AN UNLIKELY SOLUTION...AND A DRY FORECAST WILL BE MAINTAINED.
AFTER A FULL DAY IN THE WARM SECTOR ON THURSDAY...FLATTENING
HEIGHTS WILL ALLOW FOR A RETURN OF PRECIPITATION CHANCES BY
FRIDAY. THIS HAS BEEN SLOWED DOWN SLIGHTLY FOR THIS FORECAST
PACKAGE...FOCUSING MAINLY ON FRIDAY NIGHT.
TEMPERATURES THROUGH THE WEEK WILL BE VERY WARM...POSSIBLY TO NEAR
RECORD VALUES. THE WARMEST DAY OF THE WEEK FOR THE WHOLE AREA
APPEARS TO BE THURSDAY...WITH LITTLE TO NO CHANCE OF
PRECIPITATION...PLENTY OF SUNSHINE...AND SOUTHWESTERLY FLOW IN A
WELL MIXED BOUNDARY LAYER. WITH A SLIGHT SLOW DOWN IN TIMING FOR
THE NEXT WEATHER SYSTEM ON FRIDAY...SIMILAR CONDITIONS ARE NOW
ALSO EXPECTED TO PERSIST FOR THE SOUTHEASTERN FORECAST AREA ON
FRIDAY. ALTHOUGH THIS FORECAST PACKAGE WILL NOT TAKE THE LEAP...A
90 DEGREE READING IN THE FAR SOUTH ON THURSDAY OR FRIDAY SEEMS
LIKE A LEGITIMATE POSSIBILITY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
SHORT WAVE ENERGY WILL BE PUSHING EAST OF THE AREA AT THE START OF
THE PERIOD AND THIS SHOULD LEAD TO A DECREASING CHANCE OF
SHOWERS/THUNDERSTORMS THROUGH WEDNESDAY MORNING. MID LEVEL RIDGING
WILL THEN BUILD INTO THE REGION THROUGH THURSDAY. THIS WILL LEAD TO
RISING HEIGHTS AND 8H TEMPS PUSHING UP INTO THE 16 TO 18 DEGREE
CELSIUS RANGE BY THURSDAY AFTERNOON. AS A RESULT...EXPECT A DECENT
WARM UP THROUGH MID WEEK WITH HIGHS BOTH WEDNESDAY AND THURSDAY WELL
INTO THE 80S.
SOME MODEL DIFFERENCES THEN EXIST WITH HOW FAST/HOW MUCH THE RIDGE
WILL BREAK DOWN THROUGH THE END OF THE WEEK AND AS A RESULT...THE
TIMING AND PLACEMENT OF A COLD FRONT THAT MAY SAG DOWN INTO THE
AREA. THE 30.00Z ECMWF WAS THE SLOWEST WITH THIS AND A QUICK LOOK AT
THE 30.12Z ECMWF LOOKS LIKE IT IS EVEN SLOWER AND STRONGER WITH THE
RIDGE. BASED ON THESE TRENDS...WILL SLOW DOWN THE ONSET OF PCPN
THURSDAY NIGHT INTO FRIDAY. WILL THEN ALLOW FOR THE FRONT TO PUSH
DOWN INTO THE AREA THROUGH THE END OF THE WEEK...BUT BASED ON THE
LATEST ECMWF...NOT SURE HOW FAR IT WILL ACTUALLY GET. WILL THEREFORE
LINGER AT LEAST LOW POPS ALL THE WAY INTO SUNDAY. THE 30.12Z GFS IS
BRINGING CONSIDERABLY COOLER TEMPERATURES BEHIND THE FRONT THIS
WEEKEND BUT AGAIN...THE ECMWF IS TRENDING SLOWER/WARMER. WILL GO
AHEAD AND TAKE A BLEND OF THE TWO WITH MORE OF AN EMPHASIS TOWARD
THE WARMER ECMWF THROUGH EARLY NEXT WEEK.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
IT WILL BE A COMPLEX TAF FORECAST IN THE FIRST PART AND LATTER
PART OF HIS PACKAGE.
SURFACE ANALYSIS DEPICTS TWO BOUNDARIES ACROSS THE REGION THIS
MORNING. ONE...NEARLY ALIGNED EAST-WEST NEAR THE OHIO RIVER...AND
ANOTHER SAGGING SOUTHEAST TOWARD THE KDAY/KCMH/KLCK TAFS. HAVE
DECIDED THAT THE BOUNDARY NEAR THE OHIO RIVER IS MORE OF A FRONTAL
BOUNDARY WHICH DEMARCATES DEEPER MOISTURE TO THE SOUTH VERSUS
NORTH OF IT. THIS BOUNDARY IS FORECAST TO SLOWLY LIFT BACK NE AS A
WARM FRONT THROUGH THE DAY AS ANOTHER EMBEDDED UPPER LEVEL WX
DISTURBANCE TRACKS NE FROM THE SOUTHERN PLAINS TO THE LOWER OHIO
VALLEY.
IN THE NEAR TERM...GIVEN PLENTY OF RAINFALL ACROSS THE
REGION...THE LOW LEVELS ARE QUITE MOIST. OBSERVATIONS AROUND THE
REGION AND LOCAL MODEL GUIDANCE SUGGEST THAT IFR CIGS SHOULD
DEVELOP OVERNIGHT WHICH MAY PREVENT SOME TAFS FROM BEING USED AS
AN ALTERNATE DESTINATION GIVEN LOCAL REGULATIONS. FOR NOW...WILL
BE FORECASTING CIGS BETWEEN 6-9 HUNDRED FEET WITH MVFR VSBYS. LOW
CLOUDS AND MIST SHOULD BURN OFF BY LATE MORNING AND HAVE CHOSEN
15Z AS THE BEST POSSIBLE TIME FOR THIS TO OCCUR.
THEREAFTER...AS MENTIONED...A WARM FRONT WILL LIFT NE THROUGH THE
REGION LATE THIS AFTERNOON AND OVERNIGHT. THIS FEATURE WILL
COMBINE WITH AN UPPER LEVEL DISTURBANCE ALOFT TO PRODUCE SHOWERS
AND THUNDERSTORMS. IT IS TOO EARLY AT THIS POINT TO PINPOINT EXACT
TIMING OF THUNDERSTORMS SO HAVE USED THE VCTS DESCRIPTOR ALONG
WITH PREDOMINATE MVFR VSBYS IN SHOWERS. OF COURSE...WHERE
THUNDERSTORMS OCCUR...LOCAL MVFR CIGS AND LOCAL IFR VSBYS WILL BE
POSSIBLE. PCPN SHOULD DECREASE FROM SW TO NE OVERNIGHT AS THE
DISTURBANCE MOVES OFF TO THE NE AS WELL...ALLOWING SOME SUBSIDENCE
TO TAKE PLACE IN ITS WAKE.
OUTLOOK...THUNDERSTORMS POSSIBLE FRIDAY AND SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...JGL
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
200 AM EDT TUE MAY 1 2012
.SYNOPSIS...
LOW PRESSURE IS LOCATED OVER INDIANA WITH A WARM FRONT EAST ACROSS
NORTHERN OHIO TO WESTERN PENNSYLVANIA. A COLD FRONT EXTENDED
SOUTHWEST FROM THE LOW. THE LOW WILL TRACK NORTHEAST ACROSS LAKE
ERIE THIS EVENING...EVENTUALLY DRAGGING THE COLD FRONT ACROSS THE
AREA OVERNIGHT. HIGH PRESSURE WILL BUILD IN FOR TUESDAY MORNING.
TUESDAY EVENING INTO WEDNESDAY...THE FRONT WILL SURGE BACK NORTH
ACROSS THE AREA AS A WARM FRONT.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LOW NOW SE OF THE AREA...AND WITH IT THE THREAT OF SEVERE TSRA. UPDATED
TO REMOVE ALL REMAINING COUNTIES FROM WATCH 211.
INITIAL DISCUSSION...
LOW PRESSURE OVER INDIANA WILL MOVE ENE ACROSS LAKE ERIE THIS
EVENING. A WARM FRONT EAST OF THE LOW CURRENTLY EXTENDS ACROSS
NORTHWEST OHIO AND THE CENTRAL LAKESHORE AND THEN SOUTHEAST
THROUGH NORTHEAST OHIO INTO WESTERN PA. A COLD FRONT WILL FOLLOW
THE LOW MOVING ACROSS THE AREA OVERNIGHT. MAIN CONCERN FOR THIS
EVENING IS THE POTENTIAL FOR SEVERE WEATHER. WITH TEMPS IN THE
LOWER 80S IN THE WARM SECTOR ACROSS THE SOUTHERN TIER OF COUNTIES
AND DEWPOINTS NEAR 60...LI`S ARE NOW -2 TO -3 FROM FDY TO MFD.
EXPECT AIRMASS TO CONTINUE TO DESTABILIZE THROUGH 6 OR 7PM AND
THEN SLOWLY BEGIN TO BECOME MORE STABLE THROUGH THE EVENING.
FORECAST SOUNDINGS SHOW A GOOD MID LEVEL DRY SLOT INDICATING A
POTENTIAL FOR DOWN BURSTS AND AT LAST LOOK DOWNDRAFT CAPE HAD
REACHED 900J/KG. ALSO SURFACE BASED CAPES ARE JUST OVER 1000J/KG
ON RUC JUST TO OUR SOUTH AND WOULD EXPECT THAT AIR WILL BE LIFTED
NORTH INTO THE AREA THROUGH THE EVENING SO HAIL ALSO A POSSIBILITY.
RADAR SHOWS BAND OF RAIN FROM LOWER MI SOUTHWEST THRU NRN INDIANA
AND ILLINOIS WITH THUNDERSTORMS NOW DEVELOPING ON THE LEADING EDGE
OVER WEST CENTRAL INDIANA AND SRN ILLINOIS. EXPECT THESE TO TRACK
NORTHEAST WITH CURRENT MOTION BRINGING THUNDER FROM WESTERN
INDIANA INTO WESTERN CWA COUNTIES BETWEEN 8 AND 9PM. ...ALTHOUGH
DO EXPECT SHOWERS INTO NWRN BEFORE THEN. WILL HAVE CAT POPS FOR
THE ENTIRE AREA WITH THE POSSIBILITY OF SEVERE ACROSS ALL BUT THE
NORTHWEST CORNER. WILL CARRY THIS CHANCE OF SEVERE THROUGH THE
EVENING AND THEN TRANSITION TO SHOWERS OVERNIGHT WITH POPS ENDING
FROM THE NORTHWEST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
NEED TO BE BRIEF. TUESDAY MORNING SHOULD BEGIN DRY WITH HIGH
PRESSURE BUILDING IN FROM THE NORTH. THE COLD FRONT THAT MOVES
THROUGH TONIGHT SHOULD BE AROUND THE OHIO RIVER IN TE PROCESS OF
STALLING. TUESDAY AFTERNOON THE FRONT WILL TURN WARM AND REACH THE
SWRN CWA COUNTIES. DID BRING A CHANCE POP BACK TO THE WESTERN TWO
THIRDS BY EVENING DUE TO THE FRONT. CONTINUED CHANCE POPS TUESDAY
NIGHT GIVE THE FAIRLY MOIST AIRMASS ACROSS THE AREA AND THE FRONT
CONTINUING TO MOVE THROUGH. WEDNESDAY THE AREA WILL REMAIN IN THE
WARM SECTOR. MODELS DO SHOW ENOUGH MOISTURE ACROSS THE AREA FOR
CLOUDS AND THUNDERSTORMS HOWEVER GIVEN THE BUILDING SURFACE HIGH
SHAVED POPS TO LOW TO MID CHANCE. AIRMASS DRIES A BIT WEDNESDAY
NIGHT SO WILL DROP POPS MUCH OF THE AREA. THURSDAY SURFACE HIGH
STILL JUST SOUTHEAST OF THE AREA AND UPPER RIDGING TAKING PLACE AS
WELL. STARTED TO GO COMPLETELY DRY ALTHOUGH A BIT NERVOUS AS CAPES
ARE SHOWN OVER 2000J/KG DURING THE AFTERNOON SO PUT A SLIGHT
CHANCE IN THE GRAPHICS IN CASE CONVECTION BREAKS THROUGH THE CAP.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
BIG PICTURE HAS THE UPPER RIDGE BREAKING DOWN OVER THE COURSE OF THE
WEEKEND. FOR TIMING THIS FAR OUT HAVE TURNED TO THE GFS ENS AND TAKE
A COLD FRONT THROUGH THE AREA SLOWLY FRIDAY NIGHT INTO SATURDAY.
WILL HAVE TEMPS SLIGHTLY COOLER THAN THURSDAY...BUT STILL WARM.
SCATTERED SHOWERS AND THUNDERSTORMS WITH THE FRONT. COOLER FOR THE
SECOND HALF OF THE WEEKEND...RETURNING TO NEAR NORMAL WHEN THE HIGH
REALLY PUSHES DOWN INTO THE AREA.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS RAIN EXITS TO THE EAST THIS EVENING CEILINGS HAVE BRIEFLY DROPPED
TO IFR BUT HAVE NOW GENERALLY RISEN BACK TO MVFR AS A LIGHT
SOUTHERLY WIND DEVELOPS. WEAK AREA OF LOW PRESSURE NEAR LAKE ERIE WILL
SHIFT TO THE EAST OVERNIGHT WITH WINDS VEERING TO MORE WESTERLY/
NORTHWESTERLY. THIS SHOULD RESULT IN CEILINGS DROPPING BACK DOWN
TO IFR BY 8-10Z. CLOUD DEPTH WILL THIN AS WE HEAD INTO TUESDAY
MORNING AND EXPECT TO SCATTER OUT BETWEEN 15-18Z IN MOST LOCATIONS
AS DRIER AIR WORKS INTO NORTHERN OHIO. CHANCES OF SHOWERS AND
THUNDERSTORMS WILL RESUME BY LATE IN THE TAF CYCLE AS THE WARM
FRONT STARTS TO PUSH NORTH AGAIN. CONFIDENCE WAS TOO LOW IN TIMING
TO INCLUDE AT ANY OF THE TERMINALS WITH THIS PACKAGE.
.OUTLOOK...NON-VFR CONDITIONS POSSIBLE WITH SHOWERS AND
THUNDERSTORMS TUESDAY NIGHT INTO WEDNESDAY MORNING...THEN AGAIN
FROM FRIDAY INTO SATURDAY.
&&
.MARINE...
GENERALLY QUIET CONDITIONS EXPECTED ON THE LAKE THROUGH THE NEXT 5
DAYS. NOT EXPECTING WAVES GREATER THAN 2 FEET THROUGH THE PERIOD.
THIS IS ALL DUE TO THE FACT THERE WILL BE NO MAJOR WEATHER SYSTEMS
AFFECTING LAKE ERIE DURING THIS TIME PERIOD. ONLY PROBLEMS TO
CONTEND WITH IS THE THREAT FOR THUNDERSTORMS LATER THIS EVENING.
THERE WILL ALSO BE A CHANCE FOR SHOWERS AND THUNDERSTORMS AT LEAST
THROUGH FRIDAY. ONE THING TO KEEP IN MIND IS THE THREAT FOR SEVERE
THUNDERSTORMS LATER THIS EVENING ON THE LAKE. MARINERS SHOULD KEEP A
CLOSE WATCH TO THE SKY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...DJB/TK
SHORT TERM...TK
LONG TERM...OUDEMAN
AVIATION...KEC
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
147 AM EDT TUE MAY 1 2012
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL STRENGTHEN AND CONTROL THE WEATHER
THROUGH THE WEEK. SMALL AREAS OF UPPER LEVEL ENERGY WILL PROVIDE
SOME SHOWERS AND STORMS OVER THE MOUNTAINS AND MORE ISOLATED
ACTIVITY IN THE FOOTHILLS AND PIEDMONT LATE IN THE DAY. A COLD
FRONT IS EXPECTED TO MOVE FROM NORTH TO SOUTH INTO THE AREA NEXT
WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1030 PM EDT...THE SPC MESOANALYSIS PAGE IS STILL SHOWING
MUCAPES OF 2000-3000 J/KG OVER A GOOD BIT OF THE FA. SURFACE BASED
PARCELS WILL HAVE TROUBLE LIFTING AS THE CIN IS INCREASING.
HOWEVER...AN INCREASING LLVL JET AND A VERY MOIST AIRMASS IS
RESULTING IN ELEVATED CONVECTION NOW STARTING TO DEVELOP OVER THE
UPSTATE AND NE GA. WITH STEEP LAPSE RATES FROM H7-H5...THESE
ELEVATED UPDRAFTS ARE QUITE VIGOROUS AND WILL LIKELY CONTINUE TO
PRODUCE HAIL. THE SAME PROCESS...ALBEIT WITH THE FORCING COMING FROM
OROGRAPHIC LIFT...HAS TRIGGERED STRONG TO SEVERE STORMS MUCH OF THE
EVENING OVER THE CENTRAL AND NRN MTNS AND WESTERN FOOTHILLS. IT
APPEARS THAT THE LLVL JET WILL TAKE OVER AS THE PRIMARY FORCING
MECHANISM...AND CONVECTIVE CONVERGE SHOULD CONTINUE TO DECREASE
ACROSS THE MTNS. BUT...OUT ACROSS THE FOOTHILLS AND PIEDMONT OF
CAROLINAS AND NE GA THIS PROCESS IS LIKELY TO RESULT IN AN INCREASE
IN COVERAGE OVER THE NEXT COUPLE HOURS. A WEAK H5 SHORT WAVE
ANALYZED BY THE RUC OVER THE SRN APPALACHIANS WILL ALSO HELP THIS
PROCESS ALONG. THIS ISN/T THE PLAINS...AND THE LLVL JET ISN/T THAT
STRONG...SO I THINK BY 0500 UTC MOST OF THE CONVECTION SHOULD START
TO WIND DOWN. STILL...POPS HAVE BEEN RAISED TO LOW END LIKELY ALONG
THE I-85 CORRIDOR OF THE UPSTATE AND EXTREME SRN NC FOR THE NEXT
COUPLE HOURS.
AS OF 805 PM EDT...GRIDS ARE IN GOOD SHAPE. STRONG TO SEVERE STORMS
HAVE REMAINED CONFINED TO THE CENTRAL AND NRN NC MTNS AND THE NW
FOOTHILLS...EXACTLY AS WAS IN THE FORECAST.
PREVIOUS DISCUSSION...
AS OF 200 PM... 12Z NAM...LOCAL WRF AND THE 12Z GFS INDICATE THAT
CONVECTIVE INITIATION WILL OCCUR OVER THE NORTHERN MOUNTAINS IN THE
19Z-21Z TIMEFRAME...WITH CONVECTION THEN MOVING EAST THROUGH THE NC
FOOTHILLS INTO THE NORTHERN PIEDMONT. ADDITIONAL DEVELOPMENT THEN IS
FORECAST ESSENTIALLY THROUGH THE LEE TROUGH AROUND 00Z WITH STORMS
ACROSS THE NORTHERN UPSTATE INTO NE GA. CONVECTIVE ACTIVITY SHOULD
THEN WANE BY 06Z OR SO. CURRENT POP FIELD LOOKS GOOD IN REGARD TO
THIS SCENARIO.
SBCAPES ALREADY HAVE INCREASED INTO THE 1500-2000J/KG RANGE.
HOWEVER...IT LOOKS LIKE THERE IS SUFFICIENT CIN TO CAP CONVECTIVE
INITIATION UNTIL ABOUT 20Z IN THE NORTHERN MOUNTAINS. WITH BULK
SHEAR AROUND 30KT...THIS MY BE ENOUGH TO SUSTAIN UPDRAFTS AND ALLOW
CONVECTION TO SPREAD OUT OVER THE FOOTHILLS. ALSO...DCAPE OVER THE
MOUNTAINS IS AROUND 1000J...SO A FEW SEVERE STORMS ARE POSSIBLE WITH
LARGE HAIL AND DAMAGING WINDS.
ALL INDICATIONS ARE THAT THE STORMS WILL DISSIPATE BY 06Z...SO
IT SHOULD BE QUIET LATE TONIGHT WITH JUST DOME DEBRIS CLOUDINESS AND
PATCHY FOG. SOME STRATUS MAY MAKE A RUN AT THE EASTERN AND SOUTHERN
PERIPHERY OF THE CWA AROUND SUNRISE.
ON TUE...EXPECT A FEW SHOWERS TO BEGIN CROPPING UP IN THE MOUNTAINS
TUE MORNING WITH UPSLOPE FLOW AND AN APPROACHING VORT. SCATTERED
SHOWERS AND STORMS ARE THEN EXPECTED TO DEVELOP ACROSS THE NC
FOOTHILLS/PIEDMONT AS A WEAK FRONTAL BOUNDARY DROPS INTO THE AREA
DURING THE AFTERNOON. A FEW STORMS COULD MOVE OUT INTO NE GA AND THE
SC FOOTHILLS/PIEDMONT LATE IN THE DAY. CONDITIONAL INSTABILITY WILL
ONCE AGAIN BE ON THE ORDER OF 1500J/KG SO CAN`T RULE OUT A FEW
SEVERE STORMS OVER WESTERN NC WHERE WIND SHEAR IS THE GREATEST.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
AS OF 140 PM MONDAY...SHORT RANGE MODELS INDICATE THAT THE CENTER OF
H5 RIDGE WILL BUILD OVER THE SAVANNAH RIVER BASIN WEDNESDAY AND
THURSDAY. SKY COVER WILL REMAIN LIMITED TO PARTLY CLOUDY CONDITIONS
THROUGH THE PERIOD...ESPECIALLY OVER THE MTNS AND ADJACENT
FOOTHILLS. THE RIDGE WILL SUPPLY THE REGION WITH VERY WARM LLVL
THICKNESSES AND H85 TEMPS BETWEEN 16C TO 18C. USING A BLEND OF MOS
GUIDANCE...FORECAST LOW TEMPS ARE FORECAST TO RANGE FROM THE L50S
ACROSS THE MTN VALLEYS TO L60S EAST...OR AROUND 10 DEGREES ABOVE
NORMAL. THIS WILL SET THE STAGE FOR RECORD TO NEAR RECORD HIGH
TEMPERATURES EACH DAY. HERE ARE THE RECORDS FOR WEDNESDAY AND
THURSDAY FOR KGSP...KCLT...AND KAVL:
KGSP
MAY 2ND 90F IN 1959 FORECAST 90F
MAY 3RD 91F IN 1959 FORECAST 90F
KCLT
MAY 2ND 91F IN 1959 FORECAST 88F
MAY 3RD 94F IN 1902 FORECAST 91F
KAVL
MAY 2ND 88F IN 1935 FORECAST 85F
MAY 3RD 85F IN 1965 FORECAST 86F
WEDNESDAY AND THURSDAY...THE ENVIRONMENT WILL CHANGE LITTLE FROM DAY
TO DAY. FORECAST SOUNDINGS FEATURE A WEAK INVERSION AROUND H8 WITH
CIN VALUES RANGING BETWEEN 30 TO 60 J/KG. WIND FIELDS SHOULD RESULT
IN ONLY WEAK SHEAR...ESPECIALLY ON THURSDAY. THE STORM MODE SHOULD
REMAIN AS PULSE STORMS. GIVEN THE LINGERING INVERSION...LACK OF A
TRIGGER...AND SLOW STORM MOTIONS WILL FAVOR SCHC POPS EAST OF THE
MTNS...WITH CHC POPS ACROSS THE RIDGES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 145 PM MONDAY...THE MEDIUM RANGE MODELS HAVE BEEN RATHER
CHANGEABLE. MOST RECENT HPC WORD SAYS BLENDING ECMWF AND GEFS
ENSEMBLES ARE THE BEST WAY TO GO. WHEN COMPARING THE OPERATIONAL
GFS AND ECMWF START THE MEDIUM RANGE IN A MODERATE 500MB RIDGE
THURSDAY NIGHT. BOTH SHOW THURSDAY EVENING CONVECTION FROM THE
VIRGINIAS TO EASTERN NC. THIS TREND DIMINISHES FOR LATE FRIDAY AS
THE RIDGE FLATTENS. GOING INTO THE WEEKEND...THESE TWO MODELS
DIVERGE IN SOLUTIONS. THE RIDGE REBUILDS OVER THE SE ON THE ECMWF
FOR SATURDAY WHILE RIDGE RETROGRADES TO TEXAS ON THE GFS WITH TROF
FORMING OVER EAST. THE LATEST 12Z GFS BRINGS THE COLD FRONT ACROSS
OUR AREA EARLY SUNDAY WHILE THE PREVIOUS RUN WAITED UNTIL LATE
MONDAY. THE MOST RECENT ECMWF HAD A WEAK FRONT CROSSING OUR REGION
MONDAY NIGHT. OF COURSE...WITH THIS BEING A WEEK AWAY WE WILL HAVE
SLIGHT POPS IN FORECAST THROUGH THE GENERAL TIME UNTIL WE CAN NAIL
DOWN A MORE DEFINITE TIME FOR FRONTAL PASSAGE.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AT KCLT...VFR WITH HIGH CLOUDS FOR THE NEXT SEVERAL HOURS...WITH
FAIRLY HIGH TEMP/DEWPT SPREADS. THE GUIDANCE SUGGESTS YET ANOTHER
LOW CLOUD DECK DEVELOPING ACROSS THE MIDLANDS AND PIEDMONT BY
SUNRISE...HOWEVER...SATELLITE IMAGERY AND SFC OBS SHOW MUCH LESS IN
THE WAY OF CLOUD DEVELOPMENT AT THIS HOUR COMPARED TO THE PAST
SEVERAL DAYS. WILL INCLUDE A FEW HOURS OF MVFR CEILING AROUND
DAYBREAK...WITH CLOUDS SCATTERING OUT BY 14Z AT THE LATEST. SHOULD
BE VFR WITH A S TO SW WIND FROM THAT POINT ONWARD. THUNDERSTORM
CHANCES ARE TOO LOW TO INCLUDE AT THIS TIME.
ELSEWHERE...VFR THROUGH ABOUT DAYBREAK. PATCHES OF MID AND HIGH
CLOUDS MAY KEEP FOG FROM GETTING TOO DENSE IN THE MTN VALLEYS...SO
VIS WAS LIMITED TO THE MVFR RANGE AT KAVL STARTING AT 10Z. IF IT
FORMS IT SHOULD NOT CONTINUE BEYOND ABOUT 13Z AS WE WARM UP QUICKLY.
THE OTHER POSSIBLE FOG OR LOW CLOUD SPOT WILL BE KHKY AS LOW LEVEL
MOISTURE IS A BIT HIGHER DUE TO RECENT RAINFALL. THE OTHER TAF SITES
WILL BE KEPT VFR. A BRIEF MVFR CEILING WILL NOT BE RULED OUT IN THE
MIDDLE PART OF THE MORNING AS SOLAR HEATING DEVELOPS A CU FIELD...
BUT BASES SHOULD RISE UP ABOVE 030 BY 16Z AT THE LATEST. EXPECT S TO
SW WIND TO CONTINUE.
OUTLOOK...SCATTERED MAINLY DIURNAL THUNDERSTORMS WILL BE THE MAIN
PROBLEM FOR WEDNESDAY THROUGH FRIDAY. PATCHES OF FOG AND STRATUS ARE
ALSO POSSIBLE EACH MORNING AS WELL. APART FROM THAT...MOST OF THE
TIME CONDITIONS SHOULD BE VFR.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...MCAVOY/PM
SHORT TERM...NED
LONG TERM...DEO
AVIATION...PM
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1137 PM CDT MON APR 30 2012
.AVIATION...
STORMS HAVE EXITED THE AREA THIS EVENING BUT GUSTY WINDS WILL
RETURN TO THE SOUTHEAST OVERNIGHT. CONFIDENCE IS INCREASING IN LOW
STRATUS DEVELOPMENT NEAR KCDS NEAR DAYBREAK AND HAVE NOW INCLUDED
THIS IN A TEMPO. DURING THE AFTERNOON...WINDS WILL BECOME GUSTY
OUT OF THE SOUTH TO SOUTHWEST IN RESPONSE TO A DEEPENING LOW
PRESSURE SYSTEM.
&&
.PREV DISCUSSION... /ISSUED 950 PM CDT MON APR 30 2012/
UPDATE...
HAVE UPDATED THE FORECAST TO REMOVE THUNDER MENTION EXCEPT FOR
EASTERN AREAS AND REMOVED SEVERE TSTORM WATCH EXCEPT FOR THE
ROLLING PLAINS.
PREV DISCUSSION... /ISSUED 226 PM CDT MON APR 30 2012/
SHORT TERM...
WE ARE BASICALLY IN A WAIT AND SEE MODE FOR WHEN/IF SEVERE WEATHER
WILL INITIATE. 19Z RADAR IMAGE SHOWS TWO BOUNDARIES ACROSS THE
AREA...FIRST ONE WAS LOCATED SOUTHWEST OF LUBBOCK WHICH WAS ORIENTED
NORTHWEST TO SOUTHEAST WITH THE SECOND ONE LOCATED OVER THE ROLLING
PLAINS ORIENTED NORTH/SOUTH. LATEST VISIBLE SATELLITE IMAGERY AND
OFFICE TOWER CAMERA ARE SHOWING CU FIELD TRYING TO DEVELOP ALONG
THIS BOUNDARY WHILE SKIES ARE TRYING TO CLEAR IMMEDIATELY
EAST/NORTHEAST OF THE BOUNDARY. THERE IS LITTLE IN THE WAY OF
DYNAMICS TO HELP SHARPEN THE DRYLINE AND PUSH IT EAST SO FEEL THAT
THE WESTERN BOUNDARY SHOULD NOT MOVE TOO MUCH FURTHER EAST.
DEWPOINTS IMMEDIATELY NORTH AND EAST OF THE BOUNDARY HAVE ACTUALLY
BEEN SLOWLY RISING AS EVAPORATION TAKES PLACE FROM THE RAINFALL
YESTERDAY WHICH SHOULD ALSO HELP TO SHARPEN UP THE BOUNDARY A BIT.
19Z RUC RUN KEEPS KLBB CAPPED ALTHOUGH STRENGTH OF THE CAP IS NOT
INSURMOUNTABLE AND THE LATEST HRRR RUNS CONTINUE TO TRY AND BREAK
OUT CONVECTION. THUS...SEVERE WEATHER THREAT STILL LOOKS GOOD WITH
MAIN THREATS LARGE HAIL UP TO BASEBALL SIZE AS WELL AS DAMAGING
WINDS... BUT AN ISOLATED TORNADO STILL REMAINS POSSIBLE.
FORECAST FOR TONIGHT INTO TOMORROW WILL HINGE ON HOW THINGS DEVELOP
THIS AFTERNOON. LOW TEMPS WILL REMAIN A FEW DEGREES ABOVE NORMAL
OVER MOST OF THE AREA AS RICH LOW LEVEL MOISTURE REMAIN IN PLACE
OVER THE REGION. DRYLINE TOMORROW MAY TRY TO PUSH A BIT FURTHER
EAST TOMORROW BUT POOR HANDLE OF THE DRYLINE LAST SEVERAL RUNS IN
THE MODELS MAKE ME A BIT SUSPICIOUS OF WHERE IT MAY BE LOCATED
TOMORROW. IF THE WIND DOES INCREASE OUT OF THE SOUTHWEST...
TEMPERATURES WEST OF THE DRYLINE MAY JUMP INTO THE LOW/MID 90S WHILE
ALONG AND EAST OF THE DRYLINE...TEMPERATURES WILL REMAIN IN THE
80S. ALSO WENT AHEAD AND BUMPED POPS UP INTO THE LOW END OF SLIGHT
CHANCE FOR THE ROLLING PLAINS AS THERE WILL ONCE AGAIN BE QUITE A
BIT OF INSTABILITY EAST OF THE DRYLINE ALTHOUGH CAP STRENGTH MAY
LIMIT THE AMOUNT OF CONVECTION FOR TOMORROW.
JORDAN
LONG TERM...
AN UA LOW ACROSS THE EASTERN PACIFIC IS PROGGED TO NEAR THE BAJA OF
CALIFORNIA LATE TOMORROW NIGHT/EARLY WEDNESDAY MORNING...THUS
PROMOTING THE SHARPENING OF SW FLOW ALOFT. AS SUCH...THE DRYLINE
WILL BE A PROMINENT MESOSCALE FEATURE THROUGHOUT THE EXTENDED
FORECAST. FORECAST MODELS HINT AT QPF ALONG THE DRYLINE /LOCATED OFF
THE CAPROCK/ TOMORROW NIGHT...AS AN IMPULSE IN THE SW FLOW ALOFT
MOVES ACROSS THE SOUTH PLAINS. FORECAST SOLUTIONS DISPLAYED ADEQUATE
CONVERGENCE ALONG THE DRYLINE...PWATS AOA 1.00 INCH AND SFC AND MID
LEVEL INSTABILITY/CAPE OF APPROXIMATELY 1200 J/KG ACROSS THE ROLLING
PLAINS. ALTHOUGH PROGGED MODEL SOUNDINGS EXHIBITED MOISTENED
MID-LEVELS...LOW LEVELS APPEAR RELATIVELY DRY. CURRENT THINKING IS
THAT GUSTY WINDS WILL BE THE PRIMARY THREATS...WITH LITTLE RAINFALL
ACCUMULATION. HOWEVER...HAVE OPTED TO ADD MENTIONABLE POPS ACROSS
THE ROLLING PLAINS NEAREST TO THE BEST MOISTURE AXIS...AS THE
AFOREMENTIONED EMBEDDED DISTURBANCE MAY JUST BE THE SYNOPTIC SPARK
TO INITIATE STORMS. BY THURSDAY THE UA LOW WILL BE TRANSLATING
ACROSS THE BAJA OF CALIFORNIA. ONCE AGAIN THERE ARE HINTS OF CI JUST
SOUTH OF THE CWA ALONG THE DRYLINE...WHICH IS SPATIALLY DISTRIBUTED
ON THE CAPROCK EARLY THURSDAY MORNING. HOWEVER EMBEDDED IMPULSES IN
THE FLOW ALOFT BRUSHING THE FAR SERN ZONES THURSDAY NIGHT COULD
PROMOTE ADDITIONAL CHANCES OF PRECIP ACROSS THE SOUTHERN ROLLING
PLAINS. WILL HOLD OFF ON A PRECIP MENTION ATTM...AS BEST INSTABILITY
APPEARS TO BE SE OF THE FA.
THEREAFTER...UA RIDGING WILL COMMENCE TO MOVE EAST ACROSS THE REGION
FRI-SAT AS LACK OF PRECIP DESPITE A LINGERING DRYLINE SUGGESTS A
DECENT CAPPING INVERSION AT PLAY. WILL HOWEVER NEED TO MONITOR LATER
MODEL RUNS AS TEMPS IN THE 90S MAY BE ENOUGH TO BREAK THE CAP...AND
INITIATE THUNDERSTORM DEVELOPMENT. THE INFLUENCE OF THE UA RIDGE
WILL BE SHORT-LIVED AS IT SHIFTS EAST OF THE SOUTHERN PLAINS BY
SUNDAY...THANKS TO A NW PACIFIC UA LOW DEEPENING ACROSS THE GREAT
BASIN /THIS IS A RADICAL CHANGE FROM THE PREVIOUS RUN/. HINTS OF
CONVECTION OCCURRING NEAR THE STATE LINE ALONG THE DRYLINE
SUNDAY/MONDAY MORNING IS DISPLAYED BY BOTH THE GFS AND ECMWF
SOLUTIONS. WILL HOWEVER MAINTAIN SILENT POPS ATTM SINCE NEXT MONDAY
IS DAY 7 AND AS MENTIONED...A LOT OF THINGS CAN CHANGE.
FIRE WEATHER...
A DRYLINE IS EXPECTED TO SHARPEN ACROSS THE ROLLING PLAINS ON
WEDNESDAY...AND ALLOW DRIER AIR WEST OF THE DRYLINE...TO FILTER
ACROSS PORTIONS OF THE REGION. TEMPS APPROXIMATELY 15 DEGREES ABOVE
NORMAL WILL PROMOTE RELATIVE HUMIDITY VALUES TO FALL BELOW 15
PERCENT...AS 20-FOOT WIND SPEEDS NEAR/SLIGHTLY EXCEED 20 MPH. AS A
RESULT...ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS MAY
OCCUR...AND A MENTION BEYOND THE HAZARDOUS WEATHER OUTLOOK MAY BE
WARRANTED. ONLY MITIGATING FACTOR MAY WHERE AND HOW MUCH EXPECTED
RAINFALL THE AREA WILL RECEIVE TODAY...WHICH COULD PROMOTE GREENUP
AND HIGHER RELATIVE HUMIDITY VALUES THAN ANTICIPATED.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 55 91 55 88 53 / 10 0 0 0 0
TULIA 60 92 58 90 55 / 10 10 10 10 10
PLAINVIEW 61 93 59 91 57 / 10 10 10 10 10
LEVELLAND 61 92 59 93 58 / 10 10 10 10 10
LUBBOCK 63 92 61 93 60 / 10 10 10 10 10
DENVER CITY 59 94 58 93 58 / 10 10 10 10 10
BROWNFIELD 62 94 59 94 58 / 10 10 10 10 10
CHILDRESS 64 92 64 94 62 / 20 20 20 10 10
SPUR 66 91 62 94 60 / 20 20 20 10 10
ASPERMONT 68 91 64 97 63 / 20 20 20 10 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
214 AM MDT TUE MAY 1 2012
.SHORT TERM...TODAY THROUGH THURSDAY...
A GENERALLY WEST-SOUTHWESTERLY FLOW ALOFT WILL REMAIN OVER THE CWA
THIS PERIOD WITH A FEW WEAK IMPULSES EMBEDDED IN THIS FLOW PASSING
ACROSS OVER THE NEXT FEW DAYS. ONE IMPULSE WILL PASS ACROSS THIS
AFTERNOON AND EVENING AND SHOULD BRING SOME SHOWERS AND MAYBE A
COUPLE WEAK STORMS TO MAINLY THE MOUNTAINS...WITH A FEW STRAYING
OVER THE HIGH PLAINS. A BETTER CHANCE FOR ACTIVITY ON WEDS AS A
JET STREAK SHOULD RIDE ACROSS AHEAD OF A MORE SIGNIFICANT
SHORTWAVE THAT WILL MOVE ACROSS IDAHO INTO MONTANA AND NRN
WYOMING. INSTABILITIES REMAINING RATHER LOW SO EXPECT MAINLY
SHOWERS ALONG WITH ISOLATED STORMS. CLEARING OUT FOR A TIME WEDS
NIGHT INTO THURSDAY THEN SHOULD SEE SOME MORE ACTIVITY DEVELOP
INITIALLY OVER THE MOUNTAINS AS WEAK SFC BOUNDARY PUSHES AGAINST
THE MTNS AND ENHANCES UPSLOPE FLOW...WITH SCTD SHOWERS AND TSTRMS
SPREADING OVER THE PLAINS BY LATE IN THE DAY.
ONLY OTHER THING TO MENTION WILL BE SOME GUSTY WINDS AROUND THE
MTNS TODAY AS DECENT MID-LEVEL FLOW MIXES DOWN. SOME GUSTS AROUND
50 MPH POSSIBLE IN WIND-FAVORED AREAS.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY...
LOOKS LIKE A FAIRLY WET EXTENDED PERIOD UPCOMING. FRIDAY LOOKS TO
BE DRY WITH A SLOW MOVING TROUGH OVER THE WEST COAST. BY SATURDAY
AFTERNOON THE GFS IS SHOWING A BACKDOOR FRONT LYING UP AGAINST THE
LARAMIE RANGE WITH MOIST LOW LEVEL SOUTHEASTERLY FLOW INTO THE
PANHANDLE. THIS SET UP SHOULD GIVE US INCREASING CHANCES FOR
SHOWERS AND THUNDERSTORMS AS UPPER SHORTWAVES INTERACT WITH THE
FRONT. BY LATE SUNDAY INTO MONDAY...A FAIRLY POTENT PACIFIC LOW
PRESSURE SYSTEM TRACKS ACROSS SOUTHERN UTAH ON THE GFS. CURRENT
ECMWF KEEPS A MORE PROGRESSIVE OPEN WAVE MONDAY...THEN CLOSES OFF
A LOW TUESDAY MORNING. IT ALSO TRACKS THE LOW FURTHER NORTH THAN
THE GFS...BUT BOTH ARE PAINTING FAIRLY HIGH QPF FOR THE NEBRASKA
PANHANDLE AND AREAS EAST OF THE LARAMIE RANGE. AS A RESULT I WENT
HIGHER ON POPS FOR MONDAY INTO TUESDAY.
&&
.AVIATION...06Z TAFS...
VFR CONDITIONS FOR MOST LOCATIONS...THE EXCEPTION BEING KRWL.
LATEST HRRR GUIDANCE SUGGESTING MVFR CONDITIONS OUT THAT WAY AS A
COLD FRONT APPROACHES AROUND THE 12-13Z TIMEFRAME. WILL CONTINUE
TO MONITOR FOR ANY LOWER CONDITIONS. EXPECT AFTERNOON CONVECTION
ACROSS SOUTHEAST WYOMING. HARD TO PINPOINT EXACT TIMING AND
LOCATION...SO WILL CONTINUE VCTS WORDING IN TAFS.
&&
.FIRE WEATHER...
NO MAJOR CONCERNS ANTICIPATED TODAY THROUGH THURSDAY AS MIN
RELATIVE HUMIDITIES EXPECTED TO REMAIN GENERALLY ABOVE CRITICAL
THRESHOLDS. RECENT RAINS HAVE HELPED TO GREENUP FUELS SOMEWHAT.
MAIN CONCERN WILL BE GUSTY WINDS THIS AFTERNOON AND AGAIN WEDS
AFTERNOON MAINLY OVER THE LOWER ELEVATIONS OF CARBON COUNTY INTO
ALBANY COUNTY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...RE
LONG TERM/AVIATION...CLAYCOMB
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1058 PM MDT MON APR 30 2012
.AVIATION...06Z TAFS
VFR CONDITIONS FOR MOST LOCATIONS...THE EXCEPTION BEING KRWL.
LATEST HRRR GUIDANCE SUGGESTING MVFR CONDITIONS OUT THAT WAY AS A
COLD FRONT APPROACHES AROUND THE 12-13Z TIMEFRAME. WILL CONTINUE
TO MONITOR FOR ANY LOWER CONDITIONS. EXPECT AFTERNOON CONVECTION
ACROSS SOUTHEAST WYOMING. HARD TO PINPOINT EXACT TIMING AND
LOCATION...SO WILL CONTINUE VCTS WORDING IN TAFS.
CLAYCOMB
&&
PREV DISCUSSION... /ISSUED 243 PM MDT MON APR 30 2012/
SHORT TERM...TONIGHT THROUGH WEDNESDAY...
THE FLOW ALOFT WILL SLOWLY BACK THROUGH WEDNESDAY AS HEIGHTS SLOWLY
RISE. A SHORTWAVE TROUGH WILL MOVE ACROSS THE CWA EARLY TONIGHT
WITH AN INCREASE IN MID AND HIGH CLOUDS ASSOCIATED. A COLD FRONT
WILL MOVE ACROSS THE CWA LATE TONIGHT THROUGH EARLY AFTERNOON
TUESDAY. THE FRONT WILL THEN BE JUST TO OUR SOUTH AND EAST
THROUGH WEDNESDAY. THE 300 MB JET WILL BE OVER THE AREA DURING
THAT TIME AND MOISTURE AND LIFT WILL INCREASE OVER THE REGION.
SOME SHOWERS MAY DEVELOP AS EARLY AS LATE TONIGHT OVER CARBON
COUNTY AND THEN SPREAD EAST AND NORTHEAST DURING THE DAY. BY THE
AFTERNOON A WIDELY SCATTERED COVERAGE OF SHOWERS AND STORMS WILL
BE OVER THE CWA. ACTIVITY TO THE EAST OF THE LARAMIE RANGE SHOULD
BE FAIRLY HIGH BASED WITH ONLY LIGHT RAINFALL. INSTABILITY IS ONLY
MARGINAL OVER THE CWA TUESDAY AFTERNOON AND EARLY EVENING.
THE PROXIMITY OF THE 300 MB JET AND THE LOW LEVEL THETA AXIS SHOULD
HELP KEEP SOME SHOWERS GOING TUESDAY NIGHT AND WEDNESDAY MORNING
OVER MAINLY THE WEST AND NORTH PARTS OF THE CWA. MOISTURE AND
INSTABILITY ARE MORE FAVORABLE FOR SLIGHTLY STRONGER AND WETTER
ACTIVITY BY WEDNESDAY AFTERNOON WITH A PRONOUNCED LOW LEVEL THETA
RIDGE AXIS OVER THE SOUTH PART OF THE CWA AND DIFFLUENT FLOW ALOFT.
HAVE GENERALLY BUMPED UP POPS AND CLOUD COVER THROUGH TUESDAY
THROUGH WEDNESDAY. WESTERLY SURFACE WINDS WILL GUST AS HIGH AS 50
MPH ALONG AND WEST OF THE LARAMIE RANGE TUESDAY WITH SLIGHTLY LOWER
SPEEDS EXPECTED FOR WEDNESDAY. TEMPERATURES WILL CONTINUE TO BE
MILD THROUGH WEDNESDAY WITH READINGS A BIT COOLER OVER THE CWA ON
WEDNESDAY.
LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
ZONAL MIDLEVEL FLOW WILL BE OVER THE AREA THROUGH FRIDAY. EXPECT A
SLIGHT CHANCE OF AFTN SHOWERS AND TSTMS ON THURS AND FRI...MAINLY
ALONG AND EAST OF THE LARAMIE RANGE. ANY TSTMS THAT DEVELOP DURING
THE AFTN WILL LIKELY BE WEAK AND ISOLATED AS THE LLVL MOISTURE AND
INSTABILITY IS LACKING OVER THE PLAINS. HIGH TEMPS WILL BE ABOVE
NORMAL WITH 700MB TEMPS AROUND 6C/9C ON THURS/FRI. A LONGWAVE
TROUGH WILL AMPLIFY INTO THE PACIFIC NORTHWEST ON FRI NIGHT AND
SAT...INCREASING THE SOUTHWESTERLY MIDLEVEL FLOW OVER WY. SFC
PRESSURE FALLS OVER THE INTERMOUNTAIN WEST COMBINED WITH PRESSURE
RISES OVER THE NORTHERN PLAINS WILL BEGIN TO TRANSPORT LLVL
MOISTURE IN SE SFC WINDS INTO AREAS EAST OF THE LARAMIE RANGE. RAIN
CHANCES OVER THE WEEKEND WILL LIKELY BE ON THE INCREASE WITH
PERSISTENT UPSLOPE E/SE FLOW AND DYNAMICS FROM THE TROUGH TO THE
WEST. THERE IS THE POTENTIAL FOR STRONG/MARGINALLY SEVERE TSTMS TO
DEVELOP ON SAT AFTN OVER THE PLAINS. THE GFS SHOWS 1000-1500 J/KG OF
CAPE OVER THE PLAINS WITH AROUND 45 KTS OF DEEP LAYER SHEAR. THE
GENERAL CONSENSUS BETWEEN THE LONG RANGE MODELS IS TO MOVE THE
CLOSED LOW OVER THE INTERMOUNTAIN WEST VERY SLOWLY EASTWARD.
SUNDAY HAS THE POTENTIAL TO PRODUCE SEVERE TSTMS OVER MAINLY THE
NEBRASKA PANHANDLE...WITH SIMILAR SEVERE PARAMETERS AS SATURDAY. THE
TIMING OF A COLD FRONTAL PASSAGE LATE NEXT WEEKEND WILL BE
DEPENDENT ON THE EASTWARD PROGRESSION OF THE UPPER LEVEL
SYSTEM...WITH A CHANGE FROM CONVECTIVE TO MORE STRATIFORM PRECIP
BEHIND THE FRONT.
&&
FIRE WEATHER...
THE WARM...DRY AND WINDY WEATHER WILL CONTINUE OVER THE CWA INTO
THE EVENING HOURS WITH NEAR CRITICAL FIRE WEATHER CONDITIONS.
THE WEATHER WILL BE SIMILAR TUESDAY AND WEDNESDAY...WITH THE MAIN
DIFFERENCE BEING SLIGHTLY HIGHER RELATIVE HUMIDITY VALUES. IN
ADDITION...A WIDELY SCATTERED COVERAGE OF MAINLY HIGH BASED SHOWERS
AND STORMS WILL BE OVER THE AREA TUESDAY AFTERNOON AND EVENING. THE
ACTIVITY WILL BE WIDESPREAD WITH A BETTER CHANCE OF WETTING RAINFALL
FOR WEDNESDAY AFTERNOON AND EVENING. DRIER CONDITIONS ARE EXPECTED
FOR THURSDAY AND FRIDAY BEFORE A BETTER CHANCE OF SHOWERS AND
THUNDERSTORMS RETURNS FOR THE WEEKEND.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...WEILAND
LONG TERM/AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1113 AM EDT TUE MAY 1 2012
.UPDATE...
MAJOR REVISIONS BEING MADE TO SHORT TERM GRIDS AS STRONG MCV IN
NORTHEAST MO CONTINUES TO DRIVE AREA OF THUNDERSTORMS IN IL. THIS
FEATURE TO CONTINUE A NORTHEAST MOVEMENT AND WITH MODEST ELEVATED
INSTABILITY AND STRONG SHEAR ALONG WITH INCREASING THETA E SHOULD BE
ABLE TO SUSTAIN PRECIPITATION ACROSS THE AREA THIS AFTERNOON.
WORKING ON INCREASING POPS TO CATEGORICAL THROUGH THE AFTERNOON FROM
SOUTHWEST TO NORTHEAST ALONG WITH LOWERING TEMPS GIVEN INCREASED
CLOUD COVER AND RAIN. 12Z NAM12 SHOWING STRONG SHEAR ASSOCIATED WITH
THIS FEATURE AS 0-6KM VALUES IN EXCESS OF 50 KNOTS. INSTABILITY WILL
BE LIMITING FACTOR FOR SEVERE WITH COOLER SURFACE TEMPS NO NOT
EXPECTING WIDESPREAD SEVERE BUT CANNOT RULE OUT ISOLATED STRONG
STORMS IF STRONG UPDRAFTS CAN DEVELOP...ESPECIALLY NEAR WARM FRONT
ACROSS SOUTHERN AREAS. RELIED ON HRRR FOR TIMING POPS AS IT SEEMS TO
HAVE BEST HANDLE ON CONVECTION. UPDATE OUT SHORTLY.
&&
.AVIATION...
12Z TAFS...FRONTAL BOUNDARY FROM SOUTHERN ILLINOIS INTO SOUTHERN
INDIANA WILL BEGIN TO RETREAT NORTHWARD AS A WARM FRONT TODAY.
SHALLOW LOW LEVEL MOISTURE...AND WEAK WINDS HAVE RESULTED IN
WIDESPREAD FOG AND STRATUS WITH IFR CONDITIONS BEING REPORTED.
CONDITIONS EXPECTED TO IMPROVE TOWARD 15Z AS DRIER LOW LEVELS
BEGIN TO MIX TO THE SFC. A THUNDERSTORM COMPLEX EXITING OUT OF
MISSOURI WILL ENCOUNTER A MORE UNFAVORABLE ENVIRONMENT IN TERMS OF
MORE LIMITED INSTABILITY. HOWEVER...SOME INCREASE IN INSTABILITY
EXPECTED BY MID TO LATE AFTERNOON MAINLY AT KFWA AS WEAK LOW LEVEL
JET AHEAD OF THIS APPROACHING CONVECTIVE SYSTEM TRANSPORTS BETTER
LOW LEVEL MOISTURE NORTHWARD. DID ADD TEMPO GROUP FOR SHRA AT
KFWA...WITH SOME POSSIBILITY THAT THUNDER MENTION MAY NEED TO BE
ADDED EVENTUALLY FOR THE LATE AFTERNOON HOURS. VCSH MENTION ALSO
MAINTAINED TONIGHT GIVEN LOW LEVEL BOUNDARY WILL LIKELY BE
APPROACHING THE LOCAL AREA.
&&
.PREV DISCUSSION... /ISSUED 430 AM EDT TUE MAY 1 2012/
SHORT TERM...
TODAY THROUGH WEDNESDAY NIGHT...SOME LIGHT FOG WAS REMAINING EARLY
THIS MORNING UNDER LOW CLOUD CANOPY. A DISTINCT LOW CLOUD
CLEARING LINE WAS APPROACHING THE AREA FROM THE WEST...BUT AT THE
SAME TIME...HIGH CLOUD DEBRIS FROM UPSTREAM STORMS WAS SPREADING
OVER THE FCST AREA. HAVE REMOVED AREAS OF FOG THIS MORNING.
VISIBILITIES ARE EXPECTED TO REMAIN 2 MILES OR MORE. AN UPPER
LEVEL TROF WILL MOVE ACROSS THE MID MISSISSIPPI VALLEY TODAY AND
MOVE INTO THE WESTERN GREAT LAKES REGION TONIGHT. THERE IS SUPPORT
FOR STRONGER STORMS WITH THIS SYSTEM GIVEN FAVORABLE BULK SHEAR
AND SIZABLE CAPES. BLENDED THE SPECTRAL MODELS FOR A COMMON
SOLUTION THAT SUPPORTS TIMING OF THIS SYSTEM ARRIVING TONIGHT. HAVE
INCREASED STORM CHANCES TO LIKELY. THE FRONT WILL CONTINUE TO LIFE
NORTH...WITH THE BULK OF STORMS STAYING NORTH OF THE FORECAST
AREA WEDNESDAY. LEFT A CHANCE FOR STORMS OVER MAINLY MICHIGAN
COUNTIES GIVEN THE CHANCE FOR A STORM TO DEVELOP ON AN OUTFLOW
BOUNDARY ON WEDNESDAY. OTHERWISE...TEMPERATURES SHOULD BE WARMER
WEDNESDAY WITH HIGHS IN THE MID 80S...SUPPORTED BY THE 00Z MEX
MOS.
LONG TERM...
RECD HEAT XPCD TO START THIS PD ON THU AS CRUX OF BROAD UPR RIDGE
BLDS ACRS THE SERN US IN RESPONSE TO AMPLIFYING UPR TROUGH OVR THE
PACNW. ACTIVE FNTL ZONE XPCD INBTWN ON NRN EDGE OF VRY UNSTABLE WARM
SECTOR. SPATIAL DETAILS STILL UNCERTAIN WRT CONVN THU AFTN/THU NIGHT
HWVR GENERAL LEAD HERE IS TWD CONV AUGMENTATION OF PREDICTED SFC
BNDRY POSITION IN SWRLY FLW ALOFT SWD OF SPECTRAL GUIDANCE
POSITIONING OF TRUE SYNOPTIC BNDRY. THUS HELD VERY CLOSE W/PRIOR POP
GUIDANCE ALTHOUGH DID DROP MENTION OF MUCH OF THU DAYTIME PD AS LL
CAPPING INVERSION SHLD BE WELL DVLPD BY THU AM. OTHERWISE STG MIXING
DURING THE DAY WITHIN ZONE OF SIG HGT RISES ALOFT AND INTENSE LL
THERMAL RIDGE PORTEND 90S PSBL IN SOME SPOTS.
BEYOND THAT...GENERAL AGREEMENT AMG 00Z MED RANGE GUIDANCE POINTS TO
A CONSENSUS OF BROAD NRN STREAM TROUGHING SLOWLY PROGRESSING EWD
THROUGH THE END OF THE PD. THIS ALLUDES TO AN ACTUAL FROPA TWD SAT
W/SUCCESSIVE WAVE ADJUSTMENT ALG COMPOSITED OUTFLW STEMMING FM DAILY
PERIOD CONVN ACRS THE PLAINS/MIDWEST A WILDCARD AS TO ACTUAL
EFFECTIVE SFC BNDRY PLACEMENT. THUS WILL GENERALLY TOE THE LINE
W/DAILY POPS DYS4-5. HWVR DOWNSTREAM BLOCKING RIDGE DEPICTED OVR THE
ATL LENDS CREDENCE TWD OP GFS SOLUTION OF FURTHER AMPLIFICATION ACRS
THE CONUS HEADING THROUGH THE WEEKEND AND COOLING TO NEAR SEASONABLE
TEMPS BEGINNING IN DY6 (SUN).
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...SKIPPER
LONG TERM...T
AVIATION...MARSILI
UPDATE...LASHLEY
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1013 AM CDT TUE MAY 1 2012
.UPDATE...
AN UPDATE WAS JUST SENT TO LOW TEMPS FOR TODAY IN NORTHWEST IL AND
ADJACENT AREAS OF EASTERN IA AND TO LOW POPS TODAY MAINLY IN EAST
CENTRAL IA.
AREA OF SHRA CONTINUES TO LIFT NORTH BUT CONTINUES TO SHOW A
STEADY WEAKENING TREND. THIS TREND SHOULD CONTINUE AS IT MOVES
INTO A COOLER/DRIER AIRMASS OVER NORTHERN IL AND IS VERIFIED BY
LATEST HRRR RUNS. LOW POPS MAINLY NORTH OF HIGHWAY 30 IN EASTERN
IA TO CHANCE OR SLIGHT CHANCE CATEGORIES.
THE SURFACE WARM FRONT IS STILL SOUTH OF THE CWFA OVER CENTRAL MO
BUT IS FORECAST TO MOVE NORTH TODAY. THE FRONT HAS A LONG WAY TO
GO TO REACH THE NORTHERN PART OF THE CWFA BUT THERE COULD BE A
JUMP TO THE NORTH LATE THIS MORNING OR EARLY THIS AFTERNOON AS THE
WARM SECTOR HEATS UP AND MIXES OUT. THE 12Z NAM WAS USED FOR THE
FRONTAL MOVEMENT THIS AFTERNOON...WHICH PLACES THE WARM FRONT OVER
THE NORTHEAST CWFA BY LATE AFTERNOON. LOWERED TEMPS INTO THE UPPER
60S IN THE NORTHEAST. ALTHOUGH DUE TO THE LATE DAY ARRIVAL TEMPS
IN THIS AREA WILL LIKELY STAY IN THE 50S UNTIL THE FRONT ARRIVES LATE
THIS AFTERNOON.
CHANCE POPS FOR TSRA WERE MAINTAINED THROUGH THE AFTERNOON ALONG
AND NORTH WARM FRONT. SOUTH OF THE FRONT SHORT RANGE MODEL GUIDANCE
WAS SHOWING THE WARM SECTOR DESTABILIZING AND UNCAPPED BY MID
AFTERNOON. ALTHOUGH THERE IS NO APPARENT TRIGGER THIS
AFTERNOON...FELT MAINTAINING SOME SLIGHT CHANCE POPS WAS WARRANTED.
&&
.PREV DISCUSSION... /ISSUED 647 AM CDT TUE MAY 1 2012/
AVIATION...
GENERALLY VFR CONDITIONS WITH PATCHY SHALLOW FOG UNTIL 14Z AT DBQ
AND CID TERMINALS. CLOUDS TO INCREASE WITH SHRA AND ISOLATED TSRA
LIKELY AT BRL AND MLI BY 14Z WITH PERIODS OF MVFR CONDITIONS
SUGGESTED WITH CLOUD BASES OF 1-3K AGL BETWEEN 14-20Z IN LIGHT TO
MODERATE RAIN AND POSSIBLY AN EMBEDDED THUNDERSTORM. SE WINDS OF
10 TO 20+ MPH BY AFTERNOON ALL TERMINALS. PARTIAL CLEARING WITH
VFR CONDITIONS BY 21Z. TONIGHT...CHANCE FOR NOCTURNAL STORMS TO
IMPACT CID AND DBQ TERMINALS AFTER 06Z AS WARM FRONTAL BOUNDARY
BECOMES ACTIVE. NICHOLS
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
647 AM CDT TUE MAY 1 2012
.AVIATION...
GENERALLY VFR CONDITIONS WITH PATCHY SHALLOW FOG UNTIL 14Z AT DBQ
AND CID TERMINALS. CLOUDS TO INCREASE WITH SHRA AND ISOLATED TSRA
LIKELY AT BRL AND MLI BY 14Z WITH PERIODS OF MVFR CONDITIONS
SUGGESTED WITH CLOUD BASES OF 1-3K AGL BETWEEN 14-20Z IN LIGHT TO
MODERATE RAIN AND POSSIBLY AN EMBEDDED THUNDERSTORM. SE WINDS OF
10 TO 20+ MPH BY AFTERNOON ALL TERMINALS. PARTIAL CLEARING WITH
VFR CONDITIONS BY 21Z. TONIGHT...CHANCE FOR NOCTURNAL STORMS TO
IMPACT CID AND DBQ TERMINALS AFTER 06Z AS WARM FRONTAL BOUNDARY
BECOMES ACTIVE. NICHOLS
&&
.PREV DISCUSSION... /ISSUED 330 AM CDT TUE MAY 1 2012/
SYNOPSIS...
ANALYSIS AND NOWCAST TOOLS INDICATE VIGOROUS SHORT WAVE IN WESTERN
MISSOURI TO OCCLUDE AND MOVE ACROSS SE 1/2 TO 2/3 PORTIONS OF THE
AREA TODAY. THIS DYNAMIC SYSTEM IS POORLY HANDLED BY MOST SOLUTIONS
WITH HI-RES ECMWF AND LATEST 06Z RUC TRENDING CORRECTLY. AREA
TEMPERATURES HAVE CRASHED AT 2 AM INTO THE 40S OVER THE REGION WITH
39F AT FREEPORT. THIS BAROCLINICITY WILL ENHANCE MISSOURI SYSTEM FOR
LOTS OF CLOUDS AND RAIN SHOWERS AND SOME EMBEDDED THUNDER.
COMMENT...INITIALIZATION AND VERIFICATION COMBINED WITH RUN TO RUN
CONTINUITY SUPPORTS STRONGLY USE OF HI-RES ECMWF NEXT 24 HOURS.
BESIDES RESULTING IN MAJOR CHANGES TO FORECAST OF HIGHER POPS (MUCH)
AND LOWER TEMPERATURES (MUCH). THIS PUTS AREA IN PRECARIOUS POSITION
FOR STRONG CONVECTION TONIGHT WITH LOW LEVEL JET SUGGESTING
TRAINING OF STORMS WITH SOME SEVERE AND POSSIBLY HEAVY TO LOCALLY
VERY HEAVY RAINFALL.
SHORT TERM...TODAY AND TONIGHT...
TODAY...LOWERED MAX TEMPERATURES BY 5+ DEGREES ACROSS AREA WITH
NORTHERN PORTIONS POSSIBLY NOT REACHING 70F DUE TO CLOUDS AND
PRECIPITATION. POPS HAVE RAISED TO HIGH LIKELY SOUTH AND CHANCE NORTH
BUT TRENDS SUGGEST GOING EVEN HIGHER. WIDESPREAD .1 TO 25+ INCHES
SUGGESTED SOUTH OF I-80 WITH LOCALLY UP TO .5 INCHES POSSIBLE
SUGGESTED ALONG AND SOUTH OF HIGHWAY 34. THE STRONG BAROCLINIC
GRADIENT MAY ALSO RESULT IN LOW CLOUDS INTO THE PM HOURS. IF SYSTEM
STRONG ENOUGH...COULD SEE STRONGER WINDS WITH GUSTS OVER 30+ MPH IN
MODEST INTERNAL GRAVITY WAVES WITH LATENT HEAT RELEASE.
TONIGHT...WARM FRONT TO MOVE NORTH TONIGHT WITH UPPER DIFFLUENCE AND
LOW LEVEL JET SUPPORTING EVENING AND OVERNIGHT CONVECTION TO
BLOSSOM ACROSS AREA BY MIDNIGHT NORTH OF HIGHWAY 34. LOCAL HEAVY
RAIN TOOLS SUGGESTS TRAINING OF STORMS POSSIBLE WITH PW/S 1.25 TO
1.5+ INCHES WITH LOW LEVEL JET OF 40-45 KTS FOR AREAS OF 2 TO
POSSIBLY NEAR 3 INCHES FOR LATER SHIFTS. HAVE KEPT POPS LOWER DUE
TO CONCERN OF WHERE STORMS FIRE BUT SOME SEVERE STORMS AND LOCALLY
HEAVY RAINFALL ARE FAVORED ATTM. LOCAL TECHNIQUES SUGGEST LARGE
HAIL UP TO GOLF BALLS OR 1.75 INCHES IN DIAMETER WITH STRAIGHT LINE
WINDS OF 50+ MPH TO NEAR SEVERE THE SECONDARY RISK. CHANCES OF
STORMS AND HEAVY RAIN DECREASE RAPIDLY SOUTH OF HIGHWAY 34. MINS
SUGGESTED TO BE IN THE MIDDLE TO UPPER 60S. NICHOLS
LONG TERM...WEDNESDAY THROUGH MONDAY...
WET AND UNSETTLED WEATHER WILL PREVAIL OVER MUCH OF THE AREA
THROUGHOUT. CYCLONIC SW UPPER LEVEL FLOW AND NEARLY PARALLEL
STATIONARY FRONT SETTING UP FROM NEB NORTHEAST THROUGH MN AND WI
WILL PLACE THE LOCAL FORECAST AREA INTO THE MUCH WARMER...HUMID GULF
AIRMASS THAT HAS BEEN POISED TO THE SOUTH ACROSS THE SOUTHERN PLAINS
AND LOWER MS VALLEY THE PAST SEVERAL DAYS...THROUGH AT LEAST FRIDAY.
PERIODIC MID LEVEL SHORTWAVES ARE EXPECTED TO TRIGGER
THUNDERSTORM COMPLEXES ALONG THIS BOUNDARY TO THE NORTH...WHICH MAY
MIGRATE SOUTHEAST INTO AT LEAST THE NORTHERN HALF OF THE FORECAST
AREA. RESULTING OUTFLOW BOUNDARIES MAY THEN RESULT IN A SECONDARY
FRONT FURTHER SETTING UP FURTHER SOUTH OVER THE LOCAL FORECAST
AREA...THAT COULD LEAD TO HEAVY RAINFALL...AS ADVERTISED BY THE LAST
COUPLE ECMWF RUNS. BESIDES THE THREAT OF HEAVY RAINFALL...WILL ALSO
HAVE THE POTENTIAL FOR SEVERAL ROUNDS OF SEVERE WEATHER OVER
PORTIONS OF THE FORECAST AREA DUE TO THE VERY MOIST...UNSTABLE
AIRMASS AND PERIODS OF WEAK UPPER FORCING THAT ENHANCE DEEP SHEAR.
WED INTO WED NIGHT...WILL KEEP A TREND OF HIGHER CHANCE POPS NORTH
AND SLIGHT TO LOW CHANCE POPS IN THE SOUTH WHERE WARMER TEMPERATURES
ALOFT MAY EFFECTIVELY CAP CONVECTION THROUGH MUCH OF THE DAY...ONCE
THE NOCTURNAL CONVECTION DISSIPATES. SURFACE TEMPERATURES SHOULD
EASILY REACH INTO THE UPPER 70S TO LOWER 80S...WHILE DEWPOINTS CLIMB
INTO THE 60S. HAVE KEPT TEMPERATURES TRENDED ON THE CONSERVATIVE
SIDE BASED ON LOW CONFIDENCE THAT CLOUD COVER WILL CLEAR. BUILDING
INSTABILITY...ESPECIALLY IF SKIES DO CLEAR...WOULD PUSH SURFACE
BASED CAPES ABOVE 2000 J/KG. THIS...ALONG WITH A REDEVELOPING LOW
LEVEL JET BY OVERNIGHT AND A POSSIBLE SHORTWAVE BRUSHING THE
NW...WILL CONTINUE A RISK FOR SEVERE STORMS. SPC HAS A DAY 2 SLIGHT
RISK OVER MOST OF THE AREA...BUT THIS POTENTIAL LOOKS TO BE HIGHER
DURING THE LATTER HALF OF THE PERIOD...FROM LATE WED AFTERNOON INTO
LATE EVENING WITH THE AID OF THE AFOREMENTIONED LOW LEVEL JET AND
UPPER FORCING.
THURSDAY AND FRIDAY...WILL HAVE A CONTINUED POTENTIAL FOR HEAVY RAIN
AND POSSIBLE SEVERE STORMS...THAT WILL BE GREATLY DEPENDENT ON THE
FOCUS OF THE LOW LEVEL JET...WHICH THE ECMWF HAS OVER CENTRAL AND
EASTERN IA. THIS COULD EASILY LEAD TO 48 HOUR RAINFALL TOTALS WELL
OVER 2 INCHES. CONFIDENCE IS NOT HIGH ON DETAILS THIS FAR
OUT...ESPECIALLY GIVEN THE UNKNOWNS WITH CONVECTIVE TRENDS AND MCS
INTERACTIONS. FOR NOW WILL KEEP CHANCE POPS GOING WITH LOW QPF THAT
WOULD NEED TO BE INCREASED IF FORECAST CONFIDENCE INCREASES.
WILL HAVE TO HAVE SOME BREAKS IN THE ACTIVITY TO ALLOW FORECAST
HIGHS IN THE 80S TO BE ACHIEVED. HIGH DEWPOINTS WILL HOLD MINS IN
THE 60S.
FORECAST CONFIDENCE DIMINISHES CONSIDERABLY OVER THE WEEKEND INTO
EARLY NEXT WEEK...AS MEDIUM RANGE MODELS DIVERGE IN THE TIMING
AND PLACEMENT OF A RIDGE BUILDING ALOFT. THIS AFFECTS THE PLACEMENT
OF THE ASSOCIATED SURFACE HIGH...SYNOPTIC BOUNDARY...AND ASSOCIATED
FOCUS FOR RAIN AND THUNDERSTORMS. LATEST FORECAST BASED ON MODEL
BLEND HAS HIGHS COOLING FROM THE 80S SATURDAY...TO 60S BY MONDAY
WITH PRECIPITATION LIKELY BECOMING MORE IN THE FORM OF LIGHT RAIN BY
SUNDAY AND MONDAY WITH MUCH MORE LIMITED POTENTIAL FOR
THUNDERSTORMS.
SHEETS
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
NICHOLS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
801 AM EDT TUE MAY 1 2012
.SYNOPSIS...
ISSUED AT 345 AM EDT TUE MAY 1 2012
A MAINLY QUIET DAY IS EXPECTED FOR TODAY AS A FRONTAL SYSTEM
REMAINS SOUTH OF THE AREA THROUGH THE DAY. THE CHANCE OF SHOWERS
AND STORMS WILL GRADUALLY INCREASE LATE THIS AFTERNOON THROUGH
WEDNESDAY MORNING AS THE FRONT LIFTS NORTH ACROSS THE STATE. WE
WILL THEN SEE CHANCES FOR SHOWERS AND STORMS THROUGH THE WEEKEND
WITH WARM WEATHER HOLDING IN THROUGH THEN.
&&
.UPDATE...
ISSUED AT 800 AM EDT TUE MAY 1 2012
I HAVE NOTED THE MCV OVER MO HEADING NORTHEAST TOWARD SOUTHERN
LOWER MICHIGAN BY LATE AFTERNOON. THE HRRR AND RUC SEEM TO LIKE
THE FEATURE AND THE RUC SHOWS A 40 KNOT LLJ INTO CNTL IL BY 18Z.
THE HRRR KEEPS THE ACTUAL THUNDERSTORMS NEAR AND SOUTH OF I-80 BUT
BRINGS RAIN SOUTH OF I-96 BY 20Z. SO AFTER TALKING WITH IWX SHORT
TERM... WE DECIDED TO GO AHEAD AND BRING THE CONVECTION IN MID TO
LATE AFTERNOON. THE UPDATED GRIDS AND ZONES HAVE BEEN ISSUED
ALREADY.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 345 AM EDT TUE MAY 1 2012
THE MAIN FORECAST CHALLENGE THROUGH THE SHORT TERM WILL BE
DETERMINING CONVECTIVE TRENDS THROUGH THE PERIOD AS A FRONTAL
SYSTEM WILL RESIDE ACROSS THE REGION THROUGH THE PERIOD.
THE QUIETEST PERIOD OF THE SHORT TERM IS EXPECTED TO BE THE DAY
TODAY. THE AREA CONTINUES TO BE SHROUDED IN CLOUD COVER EARLY THIS
MORNING. THE CLEARING LINE...NOW ACROSS ERN WISCONSIN...IS
EXPECTED TO MOVE ACROSS THE AREA THIS MORNING. FAR WESTERN AREAS
COULD SEE SOME FOG DEVELOP IF IT CLEARS OUT EARLY ENOUGH BEFORE
DAYBREAK. WE DO NOT EXPECT THERE WILL BE ENOUGH TIME FOR THE FOG TO
BECOME A PROBLEM.
WE SHOULD SEE A DECENT AMOUNT OF SUNSHINE DURING THE DAY TODAY
WITH SOME MID/HIGH CLOUDS FLOATING ACROSS THE AREA. LATE IN THE
DAY ACROSS THE FAR SOUTH...WE WILL BEGIN TO SEE AN INFLUX OF
MOISTURE AS WAA/ISENTROPIC ASCENT INCREASES WITH THE APPROACH OF
THE STALLED OUT FRONT TO OUR SOUTH. WE MAY SEE JUST ENOUGH MOISTURE
ADVECTION FOR A LOW CHC OF A FEW SHOWERS/STORM LATE ACROSS THE SRN
COUNTIES. H850 TEMPS OF AROUND 10 TO 12C SUPPORT HIGHS IN THE 70S.
THE WARM AND MOIST ADVECTION WILL CONTINUE INTO TONIGHT AS THE LOW
LEVEL JET NOSES IN FROM THE SW LATER TONIGHT. WE EXPECT TO SEE THE
BEST THREAT OF SHOWERS/STORMS ACROSS THE SRN HALF OF THE CWFA
DURING THE LAST HALF OF THE NIGHT TONIGHT. MOISTURE TRANSPORT IS
FCST TO SPREAD ACROSS THE ENTIRE AREA...SO A CHC/SCT
SHOWERS/STORMS WILL BE EXPECTED EVEN NORTH. THIN CAPE PROFILES AND
THE ELEVATED NATURE OF THE STORMS SHOULD LIMIT SEVERE
POTENTIAL...EVEN WITH BULK SHEAR VALUES AROUND 25-35 KNOTS.
CONVECTION WILL STILL LIKELY BE AROUND THE AREA FIRST THING WED
MORNING. MODELS INDICATE THAT THE SFC WAVE MOVING NW OF THE AREA
SHOULD DRAW THE FRONT TO THE NORTH OF THE CWFA IN THE AFTERNOON.
THE SURGE OF MOISTURE TRANSPORT WILL PULL OUT IN THE AFTERNOON...
AND WE COULD SEE CLEARING TAKE PLACE AS WE GET INTO THE WARM
SECTOR. IF THIS WAS TO OCCUR...WE WOULD EASILY SEE TEMPS HIT 80 AT
INLAND LOCATIONS. CONVECTION CHCS LOOK TO DECREASE AS THE
ATMOSPHERE LOOKS TO BECOME CAPPED. STILL NOT IMPOSSIBLE TO SEE
ANOTHER WAVE MOVE THROUGH HOWEVER...SO WE KEPT A CHC IN DURING THE
AFTERNOON.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 345 AM EDT TUE MAY 1 2012
CONVECTION IS EXPECTED TO SOME EXTENT EACH DAY. THE GREATEST CHANCE
FOR STRONG STORMS IS WEDNESDAY NIGHT AND THURSDAY NIGHT (WHEN
THE LOW LEVEL IS CLOSEST). TEMPERATURES WILL UNSEASONABLY WARM INTO
FRIDAY THEN COOL OFF SOME INTO THE WEEKEND.
OVER THE PAST FEW DAYS WE HAVE BEEN WATCHING HOW THE POLAR JET
MIGRATES NORTHWARD INTO SOUTHERN CANADA THE SECOND HALF OF THIS
WEEK INTO THE WEEKEND. THAT IS THE RESULT OF THE WESTERN TROUGH
DEEPENING AND BUILDING AN UPSTREAM RIDGE OVER THE CENTRAL CONUS.
THE FARTHER NORTH THE JET GETS THE LESS LIKELY IS STRONG CONVECTION
HERE. THAT IS MOSTLY DUE TO THE LACK OF DEEP LAYERED SHEAR. THE
MODELS ARE ALL IN GOOD AGREEMENT THAT FEATURE OF THE FORECAST.
THE REAL FORECAST PROBLEMS COME IN OVER THE WEEKEND AS THE ECMWF
CONTINUES TO KEEP THE UPPER LOW OVER NE CANADA OVER NE CANADA WHILE
THE GFS CONTINUES TO DIG THE FEATURE SOUTH SOUTHEAST TOWARD NEW
ENGLAND BY LATE IN THE WEEKEND. THE END RESULT IS THE ECMWF KEEPS
THE FRONT NEAR SOUTHWEST MICHIGAN THROUGH THE WEEKEND WHICH IN TURN
KEEPS THE THREAT FOR CONVECTION EACH DAY. MEANWHILE WITH THE GFS
BRINGING THE UPPER LOW SOUTH SOUTHEAST IT ALSO BRINGS CANADIAN POLAR
AIR SOUTH INTO THE GREAT LAKES SATURDAY NIGHT INTO SUNDAY. THAT OF
COURSE DRIES OUT THE AIR AND ENDS THE RISK FOR CONVECTION BY
SATURDAY NIGHT. I AM SIDING WITH THE ECMWF HERE.
THE LOW LEVEL JET MOVES THROUGH SOUTHWEST MICHIGAN THURSDAY NIGHT
INTO FRIDAY MORNING. THAT IS WHEN THERE SHOULD BE THE GREATEST
THREAT FOR THUNDERSTORMS FOR SOUTHWEST LOWER MICHIGAN. HOWEVER WITH
THE UPPER JET WELL NORTH IN CANADA...THESE STORMS SHOULD NOT BE ALL
THAT STRONG. OVER THE WEEKEND I AM LEANING TOWARD THE ECMWF INTO THE
WEEKEND BUT DUE TO INCREASING UNCERTAINLY WE HAVE LOWER POPS
SATURDAY AND SUNDAY.
WITH THE POLAR JET SO FAR NORTH AND THE SURFACE FRONT NORTH OF
SOUTHWEST LOWER MICHIGAN THURSDAY... IT SHOULD BE VERY WARM. LOW
LEVEL THICKNESS TOOLS SUPPORT HIGHS IN THE MID 80S... EVEN WITH A
FEW CLOUDS AND SHOWERS AROUND. THE FRONT SAGS SOUTH FRIDAY AND
STALLS SATURDAY... DUE TO CLOSENESS OF THE FRONT HIGHS WILL ONLY BE
IN THE 70S FRIDAY AND SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 0800 AM EDT TUE MAY 1 2012
USING OUR TIMINIG TOOL AND THE NAM12 950 TO 900 MB RH IT SEEMS THE
LOW CLOUDS WILL BREAK UP IN THE 15Z TIME FRAME. HOWEVER NO SOONER
DOES THAT HAPPEN THEN THE MCV TO OUR SW COMES INTO OUR CWA
SOUTHERN CWA BY 21Z OR SO. THE THUNDER SHOULD STAY SOUTH THIS
AFTERNOON.
SHOULD BE MVFR CIGS/VSBY OVERNIGHT AS THE WARM FRONT PUSHES NORTH
WITH HIGHER SURFACE DEW POINT AIR. ALSO THE LOW LEVEL JET NOSES IN
AFTER 06Z SO THAT COULD SET OFF ANOTHER ROUND OF CONVECTION. DUE
TO UNCERTAINTY I DID NOT PUT SHOWERS IN TAFS.
&&
.MARINE...
ISSUED AT 345 AM EDT TUE MAY 1 2012
WINDS WILL REMAIN BELOW 20 KNOTS THROUGH MOST OF TONIGHT ACROSS
THE NEARSHORE WATERS. WINDS MAY COME UP TO AROUND 20 KNOTS LATE
TONIGHT AND ON WEDNESDAY AS SOME STRONGER WINDS COME IN WITH THE
NEXT WAVE. MOST OF THIS WIND SHOULD REMAIN WELL ABOVE THE SURFACE
SINCE WARMER AIR WILL BE MOVING IN OVER THE COOLER LAKE WATERS.
ANOTHER CORE OF WINDS WILL ARRIVE LATE THURSDAY AND THURSDAY NIGHT.
&&
.HYDROLOGY...
ISSUED AT 345 AM EDT TUE MAY 1 2012
A FAIRLY MOISTURE RICH AIR MASS WILL MOVE IN BEGINNING LATE TODAY
AND ESPECIALLY TONIGHT. PRECIPITABLE WATER IS EXPECTED TO INCREASE
TO 1.25 TO 1.50 INCHES TONIGHT. THIS AIR MASS SHOULD REMAIN IN
PLACE THROUGH THE REMAINDER OF THE WEEK AND INTO THE WEEKEND. THIS
WILL ALLOW FOR LOCALLY HEAVY RAINFALL TO OCCUR WITH ANY
SHOWERS/STORMS. WE SHOULD NOT HAVE ANY ISSUES WITH THIS. THE ONLY
ISSUE THAT COULD ARISE WOULD BE IF WAVES OF SHOWERS/STORMS START
ROLLING OVER THE SAME AREAS DURING THE NEXT FEW DAYS. THE TRACK OF
ANY SHOWERS/STORMS IS QUITE UNCERTAIN AT THIS TIME.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...NJJ
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1036 AM CDT TUE MAY 1 2012
.UPDATE...JUST COMPLETED THE FIRST UPDATE OF THE DAY...ADDRESSING
TWO MAIN TOPICS. FIRST OFF...PULLED ALL MENTION OF FOG...AS
VISIBILITIES HAVE GREATLY IMPROVED...AND MOSTLY CLEAR SKIES NOW
DOMINATE MOST OF THE CWA...EXCEPT FOR STUBBORN LOW STRATUS
HANGING FIRM MAINLY WEST OF AN ORD-BEAVER CITY LINE WHICH SHOULD
ALSO SCATTER OUT EVENTUALLY. SECOND AND OVERALL MORE IMPORTANT
FOCUS WAS THUNDERSTORM CHANCES THROUGH LATE THIS AFTERNOON. AFTER
PERUSING A NUMBER OF SHORT TERM DETERMINISTIC AND HIGH RES
MODELS...ALONG WITH SREF PROBABILITIES...FEEL THAT THE CHANCES OF
SEEING MUCH STORM DEVELOPMENT PRIOR TO 22Z-00Z ARE QUITE LIMITED.
ONE REASON FOR THIS INVOLVES THE FACT THAT THE MAIN SURFACE
TROUGH/COLD FRONT AND RESULTANT LOW LEVEL CONVERGENCE ZONE WILL
STILL REMAIN NORTHWEST OF THE CWA THROUGH THIS TIME. IN
ADDITION...EVEN THE 12Z NAM...WHICH ADVERTISES CONSIDERABLE MLCAPE
VALUES OF AROUND 3000 J/KG ACROSS MUCH OF THE CWA LATER THIS
AFTERNOON...KEEPS AT LEAST A WEAK CAP IN PLACE...WHICH SHOULD BE
TOUGH TO BREAK GIVEN THAT FORCING FROM THE PRIMARY LOW AMPLITUDE
SHORTWAVE OF INTEREST WILL NOT REALLY BE ARRIVING UNTIL THIS
EVENING. AS A RESULT...CUT BACK A BIT ON AFTERNOON POPS...AND
ALTHOUGH THEY WERE NOT HIGH IN THE FIRST PLACE...NOW HAVE ONLY A
TOKEN 20 PERCENT CHANCE LATE THIS AFTERNOON ACROSS ONLY THE
NORTHWEST AND FAR EASTERN COUNTIES...WITH MOST OF THE
CENTRAL/SOUTHWEST FREE OF STORM CHANCES UNTIL AFTER 00Z INCLUDING
THE TRI CITIES. THE EASTERN POPS ARE EVEN QUESTIONABLE...BUT BOTH
THE RUC AND SREF SOMEHOW SUGGEST CONVECTIVE INITIATION IS POSSIBLE
IN THESE AREAS SO KEPT THE SLIGHT CHANCE MENTION. OVERALL...FAVOR
THE 12Z NAM/00Z 4KM WRF-NMM EVOLUTION OF CONVECTIVE CHANCES LATE
THIS AFTERNOON INTO TONIGHT...WITH POTENTIALLY SEVERE STORMS FIRST
FIRING UP TO THE NORTH/WEST OF THE CWA...AND THEN TRYING TO BUILD
SOUTHWARD ALONG THE 850MB FRONT AND INTO A STRENGTHENING LOW LEVEL
JET AXIS THIS EVENING. SEVERE CHANCES ARE STILL THERE...BUT SHOULD
MAINLY FAVOR NEBRASKA ZONES VERSUS NORTHERN KS. MADE NO OTHER
NOTABLE CHANGES AT THIS TIME TO AFTERNOON FORECAST...INCLUDING
HIGH TEMPS.
&&
.PREV DISCUSSION... /ISSUED 604 AM CDT TUE MAY 1 2012/
AVIATION...12Z KGRI TAF...LOW LEVEL STRATUS AND BR IS EXPECTED TO
CONTINUE AT KGRI FOR THE NEXT FEW HOURS WITH PREVAILING LIFR CIGS
AND MVFR VSBYS PERSISTING THROUGH ABOUT 01/15Z. AFT
01/15Z...EXPECT A RETURN TO VFR CONDS...WITH INCREASING SOUTHERLY
WINDS...GUSTING TO 20-22KTS THROUGH THE AFTERNOON HOURS. LATE THIS
AFTERNOON...EXPECT AN APPROACHING TROUGH OF LOW PRESSURE TO NEAR
THE TERMINAL...WITH A VCTS OR -TSRA POSSIBLE BETWEEN
02/00Z-02/06Z.
PREV DISCUSSION... /ISSUED 407 AM CDT TUE MAY 1 2012/
SHORT TERM...TODAY THROUGH 12Z FRIDAY. MAIN FORECAST CONCERNS WILL
BE CHANCES FOR THUNDERSTORMS THROUGH MUCH OF THE PERIOD.
SATELLITE AND SURFACE OBSERVATIONS SHOW SOME PATCHY FOG DEVELOPING
EARLY THIS MORNING. VISIBILITIES HAVE DROPPED BELOW A MILE AT A FEW
LOCATIONS...BUT MOSTLY HAVE BEEN ABOVE A MILE. WILL KEEP THE FOG
WITH VISIBILITIES LESS THAN A MILE FOR NOW...BUT WILL WATCH TO SEE
IF WIDESPREAD VISIBILITIES DROP TO A QUARTER MILE.
A SURFACE LOW AND COLD FRONT ON THE HIGH PLAINS WITH A DRY LINE TO
THE SOUTH ALONG THE CENTRAL HIGH PLAINS WILL SLOWLY PUSH TO THE EAST
TODAY. LATE IN THE DAY AN UPPER LEVEL WAVE WILL MOVE ACROSS. CURRENT
DEW POINTS IN THE MID TO UPPER 50S ACROSS THE FORECAST AREA WILL BE
ENOUGH TO ALLOW CAPES THIS AFTERNOON TO RAISE TO OVER 4000 J/KG.
WITH THE FRONT IN THE AREA EXPECT THUNDERSTORMS TO DEVELOP ALONG THE
FRONT LATE THIS AFTERNOON AND CONTINUE INTO THE EVENING HOURS BEFORE
MOVING OFF TO THE EAST. EXPECT THERE MAY BE A LITTLE THAT LINGERS IN
THE EAST LATER TONIGHT.
THE FRONT STALLS ACROSS THE FORECAST AREA LATE TONIGHT INTO
WEDNESDAY NIGHT. ANOTHER UPPER LEVEL WAVE MOVES INTO THE AREA
WEDNESDAY AFTERNOON AND BRINGS ANOTHER CHANCE FOR THUNDERSTORMS TO
THE FORECAST AREA WEDNESDAY AFTERNOON AND NIGHT. THE NAM KEEPS THE
PRECIPITATION FURTHER NORTH THAN THE GFS. BOTH HAVE THE FRONT
FURTHER TO THE SOUTH...BUT THE UPPER WAVE IS FURTHER NORTH. WILL
KEEP CHANCES BEST IN THE NORTH...BUT KEEP SOME CHANCES ACROSS THE
ENTIRE FORECAST AREA. THE UPPER WAVE CONTINUES MOVING THROUGH THE
EASTERN PART OF THE FORECAST AREA THURSDAY SO THERE COULD BE SOME
LINGERING THUNDERSTORMS IN THE EAST ON THURSDAY. FINALLY THURSDAY
NIGHT THE WAVE MOVES TO THE EAST AND EXPECT THAT IT SHOULD BE DRY.
LONG TERM...STARTING 12Z FRIDAY...MODELS IN FAIR AGREEMENT TO START
THE EXTENDED PERIODS WITH LONG WAVE RIDGING ACROSS THE CENTRAL AND
NORTHERN PLAINS...AND A TROUGH OF LOW PRESSURE MOVING ONSHORE ACROSS
THE PACIFIC NORTHWEST. AS A RESULT...EXPECT A DRY END OF THE WORK
WEEK AND START TO THE UPCOMING WEEKEND...WITH ABOVE SEASONAL
TEMPERATURES ACROSS THE ENTIRE AREA.
THIS WARM AND DRY START TO THE EXTENDED WILL BE SHORT LIVED
THOUGH...AS THE AFOREMENTIONED TROUGH TRACKS ACROSS THE INTERMOUNTAIN
WEST AND HELPS TO ERODE THE RIDGE. AT THIS POINT EXTENDED MODELS
BEGIN TO DIVERGE FAIRLY SIGNIFICANTLY...AS THE EC IS MUCH MORE
PROGRESSIVE AND FURTHER NORTH WITH APPROACHING TROUGH...AND GFS
FURTHER AMPLIFIES THE RIDGE...INSTEAD INTENSIFYING A LARGE TROUGH OF
LOW PRESSURE ACROSS THE WESTERN STATES.
WITH SUCH A DISCREPANCY IN LONG TERM MODELS...CONFIDENCE IS NOT
PARTICULARLY HIGH BEYOND SATURDAY...AND STUCK VERY CLOSE TO CONSALL
GUIDANCE FOR POPS IN THE EXTENDED...WITH MODERATE CHANCES FOR SHOWER
AND THUNDERSTORMS BEGINNING SATURDAY EVENING AND PERSISTING THROUGH
MONDAY AFTERNOON...AND SEASONAL TO SLIGHTLY ABOVE SEASONAL
TEMPERATURES PERSISTING. WHILE CONFIDENCE IS NOT EXTREMELY
HIGH...WITH BUILDING INSTABILITY INDICATED BY GFS...AND POTENTIAL OF
PASSING FRONT EVIDENT IN EC...LIKELY WILL SEE SOME SHOWER AND
THUNDERSTORM ACTIVITY EITHER WAY OVER THE LATER HALF OF THE
WEEKEND...SOME OF WHICH WILL HAVE THE POTENTIAL TO BECOME STRONG TO
SEVERE. WITH DIFFERING SOLUTIONS IN MIND...HOWEVER...TIMING IS IN
QUESTION...AND KEPT THIS POTENTIAL SOMEWHAT VAGUE IN HWO FOR THE
TIME BEING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
956 AM CDT TUE MAY 1 2012
.DISCUSSION...
IN THE MORNING UPDATE OF THE FORECAST, ADDED IN A SMALL CHANCE OF
THUNDERSTORMS ACROSS EXTREME SOUTHEAST NEBRASKA AND SOUTHWEST
IOWA. WEAK WAVE MOVING THROUGH THE REGION...IN CONJUNCTION WITH A
VERY SUBTLE SURFACE TROUGH WAS TRIGGERING SOME CONVECTION IN
NORTHEAST KANSAS. LATEST VISIBLE SATELLITE IMAGERY INDICATES AN
ACCAS FIELD MOVING THROUGH SOUTHEAST NEBRASKA WITH SOME VERTICAL
DEVELOPMENT BETWEEN FALLS CITY AND AND BEATRICE. LATEST HRRR MODEL
SUGGESTS THAT THIS COULD DEVELOP YET THIS MORNING...AND REGIONAL
88DS HAVE SHOWN SOME MID LEVEL DEVELOPMENT JUST SOUTH OF FALLS CITY.
OTHERWISE...REMAINDER OF THE FORECAST SEEMS ON TRACK...WITH
CONVECTIVE DEVELOPMENT POSSIBLE LATER THIS AFTERNOON ACROSS
EXTREME NORTHEAST NEBRASKA ALONG AN ADVANCING COLD FRONT. 12Z NAM
AND 06Z GFS AND 09Z SREF ALSO SUGGEST THAT ISOLATED ACTIVITY
COULD DEVELOP IN THE WARM AIR ADVECTION ZONE AHEAD OF THE COLD
FRONT. HAVE NOT BOUGHT INTO THAT YET...BUT WILL DO FURTHER
ANALYSIS.
DEWALD
&&
.PREV DISCUSSION... /ISSUED 605 AM CDT TUE MAY 1 2012/
AVIATION...
12Z TAFS FOR KOMA...KLNK...KOFK.
MAIN AVIATION CONCERNS ARE TIMING OF LOW CLOUDS BREAKING UP THIS
MORNING THEN THUNDERSTORM CHANCES FOR THE AFTERNOON AND EVENING.
MOIST SOUTHERLY LOW LEVEL FLOW IS IN PLACE AHEAD OF A COLD THAT
SHOULD MOVE TOWARD THE AREA LATER TODAY. LOW CLOUDS ARE EXPECTED TO
BREAK UP THIS MORNING LEAVING VFR CONDITIONS BY LATE MORNING OR
EARLY AFTERNOON. AS THE ATMOSPHERE DESTABILIZES THIS AFTERNOON...
THUNDERSTORM CHANCES INCREASE MOSTLY AFTER 21Z. THE CHANCE WILL
CONTINUE INTO THE EVENING AND POSSIBLY OVERNIGHT. LOW CLOUDS SEEM
POSSIBLE AGAIN AFTER MIDNIGHT.
MILLER
PREV DISCUSSION... /ISSUED 333 AM CDT TUE MAY 1 2012/
DISCUSSION...
MAIN FORECAST CONCERN IS CONVECTIVE POTENTIAL TODAY AND TOMORROW.
SUBJECTIVE 00Z UPPER AIR ANALYSIS INDICATES BROADLY ZONAL FLOW
ACROSS THE CONUS...WITH A TROUGH DIGGING INTO THE PACIFIC
NORTHWEST. STRONGEST UPPER-LEVEL JET WAS FOCUSED JUST
OFFSHORE...WITH 110KT JET STREAK JUST OFF THE OR COAST. SEVERAL
WEAK SHORTWAVES WERE RIPPLING THROUGH THE FLOW...INCLUDING ONE IN
AZ...ANOTHER IN SW TX...AND ANOTHER IN WY/CO. AHEAD OF AN 850MB
TROUGH DEVELOPING IN THE LEE OF THE ROCKIES...MOISTURE WAS FLOWING
OFF THE GULF...WITH 8C+ DEWPOINTS NOSING INTO NORTHERN KS/CENTRAL
MO...AND 12C+ DEWPOINTS CLOSE BEHIND. STRONG MID-LEVEL LAPSE RATES
WERE NOTED ACROSS THE ROCKIES INTO THE HIGH PLAINS...WITH 700-500MB
TEMPERATURE DIFFERENCES OF 20-24C PEAKING IN CO/NM. SURFACE LOW
ALSO WAS DEVELOPING IN THE LEE OF THE ROCKIES...WITH LOW CENTERED IN
WESTERN SD AND SECONDARY LOW IN SOUTHWEST CO.
FOCUS IS ON CONVECTIVE POTENTIAL THIS EVENING/TONIGHT...THEN AGAIN
TOMORROW LATE AFTERNOON/EVENING/OVERNIGHT. WARMING MID-LEVEL
TEMPERATURES WILL CREATE A CAP TODAY...AND ALL MODELS EXCEPT THE NAM
AND SOME SREF MEMBERS KEEP THE CWA CAPPED THROUGH 00Z. HAVING
TROUBLE FINDING A REASON TO FOLLOW THE NAM...WITH MODELS INDICATING
RISING MID-LEVEL TEMPS...AND HAVE FOLLOWED CLOSER TO GFS/ECMWF
SOLUTION. IF ANY SURFACE-BASED STORMS DID DEVELOP IN THE
AFTERNOON...LOW-LEVEL FLOW AND 0-1KM SHEAR LOOK RATHER WEAK...BUT
DEEP-LAYER SHEAR IS STRONG ENOUGH TO SUPPORT SUPERCELLS.
THUS...THINK ANY STRAY AFTERNOON STORMS WOULD CARRY MAINLY A HAIL
AND WIND THREAT. WITH THE MORE LIKELY SCENARIO OF EVENING
THUNDERSTORMS MOVING INTO THE CWA...AND LIKELY ELEVATED...THINK THE
MAIN RISK WOULD BE HAIL. THUNDERSTORMS ARE LIKELY TO DEVELOP AND
MOVE ACROSS THE AREA OVERNIGHT...BUT DO THINK THEY SHOULD CLEAR
THROUGH BY DAYBREAK.
ON WEDNESDAY...FRONTAL BOUNDARY IS PROGGED TO STALL AND LINGER
ACROSS CENTRAL TO NORTHEAST NEB...PROVIDING A FOCUS FOR THUNDERSTORM
DEVELOPMENT ON WEDNESDAY. CAP REMAINS A CONCERN...BUT GFS/ECMWF
ARE A LITTLE MORE INCLINED TO ERODE THE CAP IN THE LATE
AFTERNOON...WITH CONVECTION BREAKING OUT ALONG THE BOUNDARY BETWEEN
21-00Z. AGAIN...LOW-LEVEL WINDS REMAIN ON THE WEAK SIDE...BUT
PRESENCE OF A BOUNDARY COULD PROVIDE A SOURCE OF LOW-LEVEL
VORTICITY...INDICATING MORE OF A TORNADO POTENTIAL ON WEDNESDAY...AS
WELL AS HAIL AND WIND THREATS AS DEEP-LAYER SHEAR REMAINS ADEQUATE
TO SUPPORT SUPERCELLS. DO THINK THAT CONVECTION WILL DEVELOP INTO A
COMPLEX AHEAD OF THE FRONT THROUGH THE NIGHT...WITH FRONT FOLLOWING
LATE WEDNESDAY NIGHT/THURSDAY MORNING. HAVE TRIED TO PUSH
CONVECTION OUT A LITTLE FASTER ON THURSDAY...THOUGH ONCE
AGAIN...FRONT HANGS UP IN OR NEAR THE CWA. STORMS MAY DEVELOP AGAIN
ALONG THAT FRONT AND MOVE INTO THE SOUTHERN CWA ON FRIDAY.
FRIDAY AND BEYOND...FORECAST BECOMES MUDDY. KEPT FRIDAY THROUGH
SATURDAY MAINLY DRY AS MID TO UPPER-LEVEL RIDGING BUILDS OVER THE
CENTRAL PLAINS...WITH THE EXCEPTION OF A SMALL AREA OF CHANCE POPS
IN THE NORTHERN CWA ON FRIDAY NIGHT AS RAIN IN SD/MN APPROACHES THE
BORDER AREA. TEMPERATURES WILL WARM THROUGH THE PERIOD WITH THE
RISING 500MB HEIGHTS...AND WITH PERSISTENT LOW-LEVEL
MOISTURE...SHOULD FEEL QUITE MUGGY. THOUGH MODEL BLENDS AND
COORDINATION WITH NEIGHBORS KEEPS PRECIP IN THE FORECAST SATURDAY
NIGHT THROUGH TUESDAY...BELIEVE THAT THIS IS NOT REPRESENTATIVE OF
HOW THE PATTERN WILL EVOLVE. STRONG UPPER-LEVEL RIDGE WILL SHIFT
EAST OF THE CWA AS UPPER LOW DEEPENS IN THE SOUTHWESTERN US...AND AS
THE LOW STRENGTHENS...SEVERAL SHORTWAVES MAY EJECT AHEAD OF
IT...BRINGING TRANSIENT CHANCES FOR SHOWERS AND THUNDERSTORMS
ACROSS THE CENTRAL PLAINS. MODELS HAVE LITTLE AGREEMENT ON THE
TIMING OF THESE WAVES...AND THUS THE BLENDS CREATE A FORECAST LOADED
WITH PRECIPITATION CHANCES WHEN ONLY A COUPLE OF PERIODS WILL LIKELY
SEE RAIN. BEST CHANCE FOR WIDESPREAD AND PERSISTENT RAIN WOULD BE
WHEN THE UPPER LOW EVENTUALLY EJECTS ACROSS THE CENTRAL PLAINS...BUT
FOR NOW...THIS IS OUTSIDE THE FORECAST PERIOD.
MAYES
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1101 AM EDT TUE MAY 1 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL SAG ACROSS THE REGION THIS MORNING WITH
HIGH PRESSURE BRIEFLY BUILDING INTO THE REGION. A WARM FRONT WILL
LIFT NORTHWARD TONIGHT WITH HIGH PRESSURE OVER THE SOUTHEASTERN
UNITED STATES BECOMING THE DOMINATE FEATURE BY THURSDAY. LOW
PRESSURE WILL MOVE ACROSS THE CENTRAL LAKES INTO QUEBEC ON FRIDAY
WITH A COLD FRONT MOVING ACROSS THE REGION BY SATURDAY MORNING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED FIRST TO ADD FOG TO LAKESHORE COUNTIES AND REALIGN GRIDS
FOR SPRINKLES AND CLOUDS. ALSO ADJUSTED HIGHS. UPDATED AGAIN TO
REFLECT AT LEAST SOME LIMITED SUN IN PLACES FOR THE EARLY
AFTERNOON ALTHOUGH WILL STILL BE MOSTLY CLOUDY ON BALANCE. CLOUDS
WILL INCREASE AGAIN MID/LATE AFTERNOON AS DEBRIS FROM ILLINOIS
CONVECTION MOVE INTO THE AREA. HIGHS WILL ALSO BE TRICKY WITH
CLOUDS...SOME SUN AND A LIGHT NORTH WIND OFF THE LAKE. FOLLOWED
HRRR MODEL TEMPS WITH MINOR ADJUSTMENTS. ALSO HRRR MODEL SHOWS
CONVECTION MOVING ACROSS THE AREA LATE THIS AFTERNOON SO WILL BE
LOOKING AT THAT AND THE EXPECTED TIMING FOR NEXT UPDATE.
PREVIOUS...HAVE DECIDED TO ADD SPRINKLES TO THE FORECAST. HOWEVER
MUCH IT MAY END UP BEING IN THE FORM OF DRIZZLE. STILL HAVE
CONCERNS ABOUT HOW FAST THE CLOUD COVER WILL LIFT...ESPECIALLY
WITH THE MIDDLE AND HIGH LEVEL CONVECTIVE DEBRIS FROM MISSOURI
MOVING TOWARD THE REGION.
PREVIOUS DISCUSSION...
A WEAK COLD FRONT WILL SAG ACROSS THE REGION THIS MORNING WITH
HIGH PRESSURE AT LEAST BRIEFLY TAKING CONTROL. THE GREATEST
UNCERTAINTY FOR THE DAY IS THE AMOUNT OF CLOUD COVER THAT WILL
PERSIST IN THE WAKE OF THE FRONT. THIS WILL HAVE SIGNIFICANT
IMPLICATIONS ON HIGH TEMPERATURES. AT THIS POINT IT APPEARS WE
WILL SEE AT LEAST SOME SUNSHINE FOR THE AFTERNOON WITH HIGHS
GENERALLY IN THE 70 TO 75 RANGE...COOLER ACROSS NW PA. HOWEVER IF
THE CLOUDS PERSIST THEN WE WILL NEED TO TRIM 4 TO 6 DEGREES FROM
THE CURRENT FORECAST.
THERE HAS BEEN A FEW AREAS OF DRIZZLE/SPRINKLES AS THE WEAK FRONT
MOVES ACROSS NW OH. BELIEVE THIS WILL CONTINUE AS IT SAGS TO THE
SOUTHEAST. PLAN TO COVER THE DRIZZLE AND PATCHY FOG WITH SHORT
TERM FORECASTS IF IT CONTINUES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
A WARM FRONT WILL MOVE TOWARD THE REGION TONIGHT WITH INCREASING
CHANCES OF SHOWERS AND THUNDERSTORMS NEAR AND NORTH OF IT. SHEAR
AND INSTABILITY LOOK RATHER WEAK SO WILL NOT MENTION ANY SEVERE
THUNDERSTORMS FOR THE OVERNIGHT HOURS. THE CHANCES OF
THUNDERSTORMS WILL CONTINUE INTO WEDNESDAY AS WE AWAIT A SURGE OF
HOT AND HUMID AIR TO ARRIVE ON THURSDAY. THURSDAY SHOULD END UP
BEING A DRY DAY WITH HIGHS SURGING WELL INTO THE 80S. STILL LOOKS
AS IF A FEW LOCATIONS MAY REACH 90. AS A COLD FRONT MOVES CLOSER
TO THE REGION LATE FRIDAY INTO FRIDAY NIGHT THERE WILL ONCE AGAIN
BE AN INCREASE OF SHOWERS AND THUNDERSTORMS. FRIDAY EVENING INTO THE
OVERNIGHT HOURS MAY BRING A ROUND OF SEVERE THUNDERSTORMS. MORE ON
THIS THROUGH THE WEEK.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
BELOW NORMAL CONFIDENCE FOR THE WEEKEND FORECAST WITH CONSIDERABLE
DIFFERENCES BETWEEN THE LONG RANGE MODELS. THE GFS IS AN OUTLIER
WITH A STRONG UPPER LEVEL TROUGH PUSHING SOUTH ACROSS QUEBEC ON
SUNDAY WHILE THE ECMWF/GEM/UKMET MAINTAIN AN UPPER LEVEL RIDGE OVER
THE GREAT LAKES REGION. HAVE TRENDED THE FORECAST TOWARDS THE BETTER
CONSENSUS...MAINTAING A WARM AIRMASS OVER THE REGION WITH A
CONTINUED CHANCE OF THUNDERSTORMS.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
WEAK LOW PRESSURE HAS SLID EAST INTO NEW YORK AND PENNSYLVANIA THIS
MORNING WITH AMPLE LOW LEVEL MOISTURE IN PLACE BEHIND IT. A FEW
LIGHT SHOWERS/DRIZZLE WILL CONTINUE TO IMPACT YNG/ERI THROUGH 14Z
BEFORE STARTING TO DRY OUT. ELSEWHERE CONDITIONS HAVE VARIED BETWEEN
IFR/MVFR EARLY THIS MORNING...BUT CEILINGS SHOULD LIFT INTO THE MVFR
RANGE BY AROUND 15Z. FORECAST CHALLENGE IS IF AND WHEN LOW CLOUDS
WILL SCATTER OUT TODAY. MODELS SOUNDINGS SHOW MOISTURE DEPTH
DECREASING WITH CLOUDS SCATTERING OUT BY EARLY AFTERNOON. HAVE BEEN
JUST A TOUCH MORE PESSIMISTIC WITH THE CLEARING TREND GIVEN HIGH
CLOUDS ARE ALREADY ARRIVING FROM THE WEST...BUT STILL EXPECT
RETURN TO VFR THIS AFTERNOON. THE WARM FRONT WILL LIFT NORTH TOWARDS THE
REGION TONIGHT WITH SHOWERS AND SCATTERED THUNDERSTORMS ARRIVING
AFTER 04Z WEST/08Z EAST.
.OUTLOOK...NON-VFR CONDITIONS POSSIBLE WITH SHOWERS AND
THUNDERSTORMS INTO WEDNESDAY MORNING...THEN AGAIN FROM FRIDAY
INTO SATURDAY.
&&
.MARINE...
WEAK LOW PRESSURE NEAR EASTERN LAKE ERIE WILL TRACK TO THE EAST
COAST TODAY. LIGHT SOUTHERLY WINDS WILL DEVELOP IN THE WAKE OF THIS
SYSTEM THIS AFTERNOON...PUSHING A WARM FRONT NORTH ACROSS THE LAKE
OVERNIGHT. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL LIKELY
ACCOMPANY THE FRONT. A VERY WARM AIRMASS WILL BE OVER THE LAKE FOR
THE END OF THE WEEK WITH A WEAK FRONTAL BOUNDARY SAGGING SOUTH
DURING THE FRIDAY TO SATURDAY TIME FRAME. THIS FRONT WILL AGAIN BE A
FOCUS FOR SHOWERS AND THUNDERSTORMS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MULLEN
NEAR TERM...TK/MULLEN
SHORT TERM...MULLEN
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
652 AM EDT TUE MAY 1 2012
.SYNOPSIS...
A WARM FRONT WILL MOVE NORTHEAST THROUGH THE REGION TODAY...BRINGING
A CHANCE OF SHOWERS AND THUNDERSTORMS. PRECIPITATION WILL CONTINUE
TO BE POSSIBLE THROUGH WEDNESDAY...BEFORE HIGH PRESSURE BUILDS IN ON
THURSDAY AND PROVIDES VERY WARM TEMPERATURES WITH DRY CONDITIONS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A BOUNDARY IS CURRENTLY RESIDING JUST SOUTH OF THE FORECAST
AREA...ALTHOUGH IT IS NOT TERRIBLY EASY TO PICK UP ON SURFACE
OBSERVATIONS. THE FLOW IS SLIGHTLY MORE SOUTHERLY SOUTH OF THE
CWA...BUT THE FEATURE IS PERHAPS EASIEST TO PICK OUT ON MODEL
1000MB-500MB RH FIELDS...WHERE THERE IS A SHARP CONTRAST WITH THE
DRIER HIGH PRESSURE OVER THE SOUTHERN GREAT LAKES AND NORTHERN
OHIO VALLEY.
A DRY FORECAST WILL BEGIN THE PERIOD...WITH ACTIVITY ASSOCIATED
WITH THIS FRONT RATHER SCATTERED AND ALL WELL SOUTH OF THE REGION.
HOWEVER...THE BOUNDARY WILL PROGRESS NORTH INTO THE REGION AS A
WARM FRONT...AND ACTIVITY TO THE WEST AND SOUTHWEST WILL BEGIN TO
AFFECT THE AREA BY AFTERNOON. EVIDENCE OF THIS IS VISIBLE WITH THE
CLUSTER OF STORMS OVER NORTHWESTERN TENNESSEE...WHICH HAS SOMEWHAT
OF A NORTHWARD COMPONENT TO ITS MOTION. THE HRRR DOES SHOW THIS
CLUSTER...BUT ITS PLACEMENT AND TIMING ARE NOT TOTALLY CORRECT.
OVERALL THE POP FORECAST HAS NOT CHANGED TOO MUCH FROM THE
PREVIOUS GRIDS...WITH A SLIGHTLY SLOWER ONSET OF THE HIGHER CHANCE
POPS UNTIL LATER IN THE DAY...BUT MAINTAINING A LOW CHANCE /
SLIGHT CHANCE EARLIER IN THE DAY AS THE FRONT MOVES NORTH. THE
BEST CHANCES FOR PRECIPITATION APPEAR TO COME DURING THE EVENING
(DETAILED BELOW IN THE SHORT TERM SECTION).
THE MAX TEMP FORECAST IS SLIGHTLY CONVOLUTED TODAY...GIVEN THE
CLOUDS AND PRECIPITATION THAT WILL AFFECT THE WHOLE AREA...BUT
ESPECIALLY THE SOUTH AND SOUTHWEST DURING THE DAY TIME HOURS. WITH
THE POSSIBILITY OF MORE SUN IN THE NORTH AND NORTHEAST...THIS MAY
OFFSET THE TYPICAL TEMPERATURE DISTRIBUTION TO RESULT IN SIMILAR
HIGHS ACROSS THE WHOLE CWA TODAY. THE CLOUDS AND EVENTUAL
PRECIPITATION SHOULD BE ENOUGH TO HOLD THINGS IN THE 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
BY LATE AFTERNOON AND INTO THE EVENING...ATTENTION WILL BE TURNED
TO CONVECTION FIRING ON THE ADVANCING WARM FRONT...AS WELL AS
ACTIVITY MOVING IN FROM THE WEST (A PARTIAL DESCENDANT OF THE
CURRENT ACTIVITY IN MISSOURI AND OKLAHOMA). A SHORTWAVE WILL MOVE
INTO THE AREA AND INTERACT WITH AN AIRMASS THAT SHOULD BE
DESTABILIZING TO SOME EXTENT. MIXED LAYER CAPE VALUES OF AROUND
1000 J/KG WILL BE POSSIBLE IN THE SOUTH...WHERE MID LEVEL LAPSE
RATES ARE SLIGHTLY STEEPER AND BOUNDARY LAYER MOISTURE WILL BE
INCREASING. LIFT PROVIDED BY THE SHORTWAVE AND SOME MODEST (THOUGH
NOT BY ANY MEANS INTENSE) CONVERGENCE ON A LOW LEVEL JET WILL
ALLOW FOR STORM DEVELOPMENT. SHEAR IS NOT ESPECIALLY STRONG...BUT
0-6KM BULK SHEAR OF 40 KNOTS WILL ALLOW FOR SOME ORGANIZATION. THE
SEVERE THREAT APPEARS GREATEST IN THE SOUTH...WHERE GREATER
INSTABILITY WILL BE MORE LIKELY. HOWEVER...THE PRESENCE OF SAID
INSTABILITY MAY BE DIMINISHED IF RAIN OCCURS AHEAD OF THE MORE
INTENSE FORCING.
BEYOND THE PASSAGE OF THE SYSTEM THIS EVENING...THE CONVECTIVE
FORECAST BECOMES RATHER DIFFICULT IN TERMS OF SPECIFIC TIMING AND
PLACEMENT. SMEARY MODEL QPF BEHIND THE TUESDAY NIGHT SYSTEM IS
TOUGH TO PLACE WITH REGARDS TO FORCING SIGNALS...ESPECIALLY AS MID
LEVEL RIDGING CONTINUES TO BUILD INTO THE AREA DURING THIS TIME
FRAME. WILL KEEP POPS RATHER LIMITED ON WEDNESDAY...BEFORE GOING
DRY BY WEDNESDAY AFTERNOON IN THE SOUTHWEST AND WEDNESDAY NIGHT
ELSEWHERE. BY THIS POINT...MOST OF THE MODELS ARE DEPICTING
FORCING WELL NORTH OF THE CWA AS THE WARM SECTOR ESTABLISHES
ITSELF OVER THE OHIO VALLEY. ANOTHER WRENCH IN THE SOLUTION
INVOLVES THE POSSIBILITY OF SOME OF THE ACTIVITY OVER MICHIGAN
TURNING SOUTH AND PUNCHING THROUGH THE RIDGE INTO CENTRAL OHIO ON
WEDNESDAY NIGHT. THOUGH IT IS NOT AN IMPOSSIBILITY...IT SEEMS LIKE
AN UNLIKELY SOLUTION...AND A DRY FORECAST WILL BE MAINTAINED.
AFTER A FULL DAY IN THE WARM SECTOR ON THURSDAY...FLATTENING
HEIGHTS WILL ALLOW FOR A RETURN OF PRECIPITATION CHANCES BY
FRIDAY. THIS HAS BEEN SLOWED DOWN SLIGHTLY FOR THIS FORECAST
PACKAGE...FOCUSING MAINLY ON FRIDAY NIGHT.
TEMPERATURES THROUGH THE WEEK WILL BE VERY WARM...POSSIBLY TO NEAR
RECORD VALUES. THE WARMEST DAY OF THE WEEK FOR THE WHOLE AREA
APPEARS TO BE THURSDAY...WITH LITTLE TO NO CHANCE OF
PRECIPITATION...PLENTY OF SUNSHINE...AND SOUTHWESTERLY FLOW IN A
WELL MIXED BOUNDARY LAYER. WITH A SLIGHT SLOW DOWN IN TIMING FOR
THE NEXT WEATHER SYSTEM ON FRIDAY...SIMILAR CONDITIONS ARE NOW
ALSO EXPECTED TO PERSIST FOR THE SOUTHEASTERN FORECAST AREA ON
FRIDAY. ALTHOUGH THIS FORECAST PACKAGE WILL NOT TAKE THE LEAP...A
90 DEGREE READING IN THE FAR SOUTH ON THURSDAY OR FRIDAY SEEMS
LIKE A LEGITIMATE POSSIBILITY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
SHORT WAVE ENERGY WILL BE PUSHING EAST OF THE AREA AT THE START OF
THE PERIOD AND THIS SHOULD LEAD TO A DECREASING CHANCE OF
SHOWERS/THUNDERSTORMS THROUGH WEDNESDAY MORNING. MID LEVEL RIDGING
WILL THEN BUILD INTO THE REGION THROUGH THURSDAY. THIS WILL LEAD TO
RISING HEIGHTS AND 8H TEMPS PUSHING UP INTO THE 16 TO 18 DEGREE
CELSIUS RANGE BY THURSDAY AFTERNOON. AS A RESULT...EXPECT A DECENT
WARM UP THROUGH MID WEEK WITH HIGHS BOTH WEDNESDAY AND THURSDAY WELL
INTO THE 80S.
SOME MODEL DIFFERENCES THEN EXIST WITH HOW FAST/HOW MUCH THE RIDGE
WILL BREAK DOWN THROUGH THE END OF THE WEEK AND AS A RESULT...THE
TIMING AND PLACEMENT OF A COLD FRONT THAT MAY SAG DOWN INTO THE
AREA. THE 30.00Z ECMWF WAS THE SLOWEST WITH THIS AND A QUICK LOOK AT
THE 30.12Z ECMWF LOOKS LIKE IT IS EVEN SLOWER AND STRONGER WITH THE
RIDGE. BASED ON THESE TRENDS...WILL SLOW DOWN THE ONSET OF PCPN
THURSDAY NIGHT INTO FRIDAY. WILL THEN ALLOW FOR THE FRONT TO PUSH
DOWN INTO THE AREA THROUGH THE END OF THE WEEK...BUT BASED ON THE
LATEST ECMWF...NOT SURE HOW FAR IT WILL ACTUALLY GET. WILL THEREFORE
LINGER AT LEAST LOW POPS ALL THE WAY INTO SUNDAY. THE 30.12Z GFS IS
BRINGING CONSIDERABLY COOLER TEMPERATURES BEHIND THE FRONT THIS
WEEKEND BUT AGAIN...THE ECMWF IS TRENDING SLOWER/WARMER. WILL GO
AHEAD AND TAKE A BLEND OF THE TWO WITH MORE OF AN EMPHASIS TOWARD
THE WARMER ECMWF THROUGH EARLY NEXT WEEK.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
DUE TO THE RECENT RAINFALL...THE LOW LEVELS OF THE ATMOSPHERE REMAIN
MOIST THIS MORNING. THIS HAS RESULTED IN A POTPURRI OF LOW LEVEL
CLOUDS ACROSS THE REGION WITH CIGS VARYING FROM IFR TO VFR. VSBYS
FOR THE MOST PART WERE MVFR. WILL HOLD ON TO SOME IFR/MVFR CIGS
THROUGH THE FIRST PART OF THE TAF AND THEN SUSPECT THAT CIGS WILL
RISE TO VFR BY LATE MORNING OR EARLY AFTN ALONG WITH A DISSIPATION
OF MVFR VSBYS.
THEREAFTER...A WARM FRONT WILL LIFT NE THROUGH THE REGION THIS
AFTERNOON AND OVERNIGHT. THIS FEATURE WILL COMBINE WITH AN UPPER
LEVEL DISTURBANCE ALOFT TO PRODUCE SHOWERS AND THUNDERSTORMS. SOME
SCATTERED SHOWER/THUNDERSTORM ACTIVITY MAY DEVELOP ACRS THE SW
CWFA BY AS EARLY AS 18Z AS THE WARM FRONT ADVANCES NE.
HOWEVER...TAF WISE...HAVE DECIDED TO FOCUS ON THE MORE WIDESPREAD
SHOWER/EMBEDDED THUNDERSTORMS EXPECTED LATE THIS AFTERNOON INTO
THE OVERNIGHT HOURS. IT IS TOO EARLY AT THIS TIME TO PINPOINT
EXACT TIMING AND DURATION OF THUNDERSTORMS SO HAVE USED THE VCTS
DESCRIPTOR ALONG WITH PREDOMINATE MVFR VSBYS IN SHOWERS. OF
COURSE...WHERE THUNDERSTORMS OCCUR...LOCAL MVFR CIGS AND LOCAL IFR
VSBYS WILL BE POSSIBLE. PCPN SHOULD DECREASE FROM SW TO NE
OVERNIGHT AS THE DISTURBANCE AND WARM FRONT MOVE OFF TO THE NE.
HAVE PLACED SOME MVFR CIGS/VSBYS AT THE TAFS ONCE THE MAIN BULK
OF PCPN HAS PUSHED OFF TO THE EAST ALTHOUGH LOWER CONDITIONS COULD
DEVELOP BUT CONFIDENCE IS NOT HIGH AT THIS TIME.
OUTLOOK...THUNDERSTORMS POSSIBLE FRIDAY AND SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...JGL
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS SPOKANE WA
857 AM PDT Tue May 1 2012
.SYNOPSIS...
A number of weather disturbances will move over the area this
week. The result will be below normal temperatures and occasional
intervals of rain showers in valleys with rain and snow showers
over mountains. Light snow accumulations are possible in the
mountains from time to time. Breezy to locally windy conditions
are also expected at various times for much of the week.
&&
.DISCUSSION...
A weak wave passing through the Central Panhandle Mountains of
Idaho this morning will provide a focus for an organized area of
showers. Snow levels will be near 3500 feet supporting some snow
on Fourth of July and Lookout Passes but given time of year it is
not expected to stick to roadways. Otherwise expect an increase in
showers this afternoon due to a cold pool aloft over the area of
-25 to -27C at 500mb, and afternoon heating which will destabilize
the atmosphere. As 850mb winds back to the southwest in advance of
an approaching wave off the Washington coast, upslope winds will
enhance shower activity over the Northern Mountains. HRRR model
data supports this idea with numerous showers over this area while
scattered light showers develop elsewhere. Exception to this is
the lee of the Cascades where downslope flow will keep the Methow
and Wenatchee River valleys dry as well as the Moses Lake area.
GFS model also continue to argue a minimal threat for
thunderstorms this afternoon near the Canadian border. Given
marginal instability for thunder opted to leave mention out of
forecast. But an isolated lightning strike is not out of the
question today. JW
&&
.AVIATION...
12Z TAFS: Cool and somewhat unstable air-mass along with having
the jet stream in close proximity to aviation sites today into
tomorrow will result in showers at times, regardless of time
of day, and some gusty winds. Overall VFR conditions should
prevail at aviation sites into 12Z Wednesday. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 54 35 54 37 50 40 / 40 40 40 10 80 50
Coeur d`Alene 51 35 51 36 50 41 / 40 40 60 10 80 70
Pullman 51 34 51 37 51 40 / 20 20 30 10 80 70
Lewiston 59 41 59 41 60 44 / 10 10 10 10 80 70
Colville 59 36 58 36 54 41 / 60 50 50 10 80 70
Sandpoint 49 35 49 34 51 39 / 70 60 60 10 80 80
Kellogg 45 35 46 33 49 38 / 90 50 70 10 80 70
Moses Lake 62 37 62 40 59 41 / 10 10 10 10 60 30
Wenatchee 59 41 60 42 56 44 / 10 10 10 30 60 30
Omak 62 33 62 38 56 40 / 10 30 10 10 80 60
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
600 AM MDT TUE MAY 1 2012
.AVIATION...12Z TAFS...
VFR CONDITIONS FOR MOST LOCATIONS...THE EXCEPTION BEING KRWL.
LATEST HRRR GUIDANCE CONTINUES TO FORECAST MVFR CONDITIONS OUT
THAT WAY AS A COLD FRONT APPROACHES. LOOK FOR LOWERING CONDITIONS
AROUND THE 15Z TIME FRAME. WILL CONTINUE TO MONITOR FOR ANY LOWER
CONDITIONS. EXPECT AFTERNOON CONVECTION ACROSS SOUTHEAST WYOMING.
HARD TO PINPOINT EXACT TIMING AND LOCATION...SO WILL CONTINUE VCTS
WORDING IN TAFS.
&&
.PREV DISCUSSION... /ISSUED 214 AM MDT TUE MAY 1 2012/
SHORT TERM...TODAY THROUGH THURSDAY...
A GENERALLY WEST-SOUTHWESTERLY FLOW ALOFT WILL REMAIN OVER THE CWA
THIS PERIOD WITH A FEW WEAK IMPULSES EMBEDDED IN THIS FLOW PASSING
ACROSS OVER THE NEXT FEW DAYS. ONE IMPULSE WILL PASS ACROSS THIS
AFTERNOON AND EVENING AND SHOULD BRING SOME SHOWERS AND MAYBE A
COUPLE WEAK STORMS TO MAINLY THE MOUNTAINS...WITH A FEW STRAYING
OVER THE HIGH PLAINS. A BETTER CHANCE FOR ACTIVITY ON WEDS AS A
JET STREAK SHOULD RIDE ACROSS AHEAD OF A MORE SIGNIFICANT
SHORTWAVE THAT WILL MOVE ACROSS IDAHO INTO MONTANA AND NRN
WYOMING. INSTABILITIES REMAINING RATHER LOW SO EXPECT MAINLY
SHOWERS ALONG WITH ISOLATED STORMS. CLEARING OUT FOR A TIME WEDS
NIGHT INTO THURSDAY THEN SHOULD SEE SOME MORE ACTIVITY DEVELOP
INITIALLY OVER THE MOUNTAINS AS WEAK SFC BOUNDARY PUSHES AGAINST
THE MTNS AND ENHANCES UPSLOPE FLOW...WITH SCTD SHOWERS AND TSTRMS
SPREADING OVER THE PLAINS BY LATE IN THE DAY.
ONLY OTHER THING TO MENTION WILL BE SOME GUSTY WINDS AROUND THE
MTNS TODAY AS DECENT MID-LEVEL FLOW MIXES DOWN. SOME GUSTS AROUND
50 MPH POSSIBLE IN WIND-FAVORED AREAS.
LONG TERM...THURSDAY NIGHT THROUGH MONDAY...
LOOKS LIKE A FAIRLY WET EXTENDED PERIOD UPCOMING. FRIDAY LOOKS TO
BE DRY WITH A SLOW MOVING TROUGH OVER THE WEST COAST. BY SATURDAY
AFTERNOON THE GFS IS SHOWING A BACKDOOR FRONT LYING UP AGAINST THE
LARAMIE RANGE WITH MOIST LOW LEVEL SOUTHEASTERLY FLOW INTO THE
PANHANDLE. THIS SET UP SHOULD GIVE US INCREASING CHANCES FOR
SHOWERS AND THUNDERSTORMS AS UPPER SHORTWAVES INTERACT WITH THE
FRONT. BY LATE SUNDAY INTO MONDAY...A FAIRLY POTENT PACIFIC LOW
PRESSURE SYSTEM TRACKS ACROSS SOUTHERN UTAH ON THE GFS. CURRENT
ECMWF KEEPS A MORE PROGRESSIVE OPEN WAVE MONDAY...THEN CLOSES OFF
A LOW TUESDAY MORNING. IT ALSO TRACKS THE LOW FURTHER NORTH THAN
THE GFS...BUT BOTH ARE PAINTING FAIRLY HIGH QPF FOR THE NEBRASKA
PANHANDLE AND AREAS EAST OF THE LARAMIE RANGE. AS A RESULT I WENT
HIGHER ON POPS FOR MONDAY INTO TUESDAY.
&&
FIRE WEATHER...
NO MAJOR CONCERNS ANTICIPATED TODAY THROUGH THURSDAY AS MIN
RELATIVE HUMIDITIES EXPECTED TO REMAIN GENERALLY ABOVE CRITICAL
THRESHOLDS. RECENT RAINS HAVE HELPED TO GREEN UP FUELS SOMEWHAT.
MAIN CONCERN WILL BE GUSTY WINDS THIS AFTERNOON AND AGAIN WEDS
AFTERNOON MAINLY OVER THE LOWER ELEVATIONS OF CARBON COUNTY INTO
ALBANY COUNTY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...RE
LONG TERM/AVIATION...CLAYCOMB
AREA FORECAST DISCUSSION
NWS ALBANY NY
343 PM EDT TUE MAY 1 2012
.SYNOPSIS...
A WEAK DOME OF HIGH PRESSURE WILL MOVE ACROSS THE REGION TONIGHT.
HOWEVER...CHANGES ARE ON THE WAY AS WARMER AIR ATTEMPTS TO BUILD
FROM THE SOUTHERN PORTIONS OF THE COUNTRY. ALONG WITH THAT
CHANGE...THERE WILL A CHANCE FOR SHOWERS AND THUNDERSTORMS FOR THE
SECOND HALF OF THE WEEK.
&&
.NEAR TERM /TONIGHT/...
STRATUS DECK CONTINUES TO PLAQUE THE REGION WITH SOME BREAKS IN
THE OVERCAST ACROSS THE MID HUDSON VALLEY. TEMPERATURES HAVE
STRUGGLED TO GET OUT OF THE 50S FOR MOST OF THE CWA...SOME LOWER
60S NOW BEING OBSERVED ACROSS THE MID HUDSON VALLEY WHERE THOSE
BREAKS IN THE CLOUDS ARE UNDERWAY. HOWEVER...EXPECTATION IS FOR
THE STRATUS DECK TO BECOME RE-ESTABLISHED TONIGHT AS THE
COMBINATION OF A MOIST GROUND AND BOUNDARY LAYER COOLING FOR
CONDENSATION TO OCCUR. IN FACT...SFC DEWPOINT DEPRESSIONS ARE
EXPECTED TO NARROW ALONG WITH APPLICATIONS OF THE CROSS OVER
TECHNIQUE AND LOWERING THE MRI IN THE LOWEST 100MB /PER BUFKIT/ TO
RESULT IN PATCHY/AREAS OF FOG.
MORE OF AN INTEREST IS THE WELL DEFINED MCV TRACKING NORTHEAST
ACROSS IL/IN. NCEP MODEL SUITE NOT PERFORMING TOO WELL WITH THIS
FEATURE AS WE REFERRED TO THE NAM ARW CORE AND HOURLY RAPID REFRESH
/REPLACED THE RUC THIS MORNING/. THE ANALYSIS OF THESE MODELS
SUGGESTS THIS MCV SHOULD WEAKEN AS IT APPROACHES THE ANTICYCLONIC
FLOW ACROSS PA/NY. HOWEVER...IT MAY SURVIVE JUST ENOUGH TO WARRANT
THE CHANCE OF POPS SOUTH OF I90 OVERNIGHT. IN ADDITION...THE
THERMAL WIND FORECASTS FROM 850-300MB SUGGEST A MORE EASTWARD
PROGRESSION TO FURTHER SUPPORT THE CHANCE POPS. OVERNIGHT LOWS
WILL DROP BACK MAINLY INTO THE 40S CWA-WIDE.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
A VERY CHALLENGING FORECAST PERIOD WITH LOW CONFIDENCE APPROACH.
CONVECTIVE UPSTREAM TRENDS WILL ULTIMATELY DICTATE THE SYNOPTIC
AND MESOSCALE INFLUENCES AS SPRING ATTEMPTS TO MAKE A STRONG PUSH
INTO THE REGION.
WHAT WE CAN DECIPHER FROM THE NCEP MODEL SUITE AND INTERNATIONAL
GUIDANCE ARE A TREND TOWARD INCREASING HEIGHTS WITH WARMER
TEMPERATURES AND INCREASING AMOUNTS OF MOISTURE. THE CHANCE FOR
SHOWERS WILL EXPAND ACROSS THE REGION WEDNESDAY AS THE NEXT SURGE
OF WARM ADVECTION AND THETA-E ADVECTION APPROACH. MID LEVEL
INSTABILITY REMAINS RATHER POSITIVE /SHOWALTER VALUES INTO THE
SINGLE DIGIT TERRITORY/ TO WITHHOLD THE MENTION OF THUNDER AT THIS
TIME. HOWEVER...THAT IS EXPECTED TO GRADUALLY CHANGE WEDNESDAY
NIGHT INTO THURSDAY NIGHT WHERE WE WILL INTRODUCE THE CHANCE FOR
THUNDERSTORMS.
MOS NUMBERS DO SUPPORT THE INCREASING THERMAL PROFILES BUT CLOUD
COVER REMAINS A CHALLENGE. AT THIS POINT...WE WILL CONTINUE TO
FAVOR ON THE COOLER SIDE OF THE GUIDANCE ENVELOPE.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE EARLY PORTION OF THE LONG TERM FORECAST IS UNCERTAIN WITH
WIDE POSSIBLE RANGES IN TEMPS AND POPS. DESPITE BUILDING HEIGHTS
ALOFT INTO FRIDAY...THE WEATHER AT THE SURFACE LOOKS RATHER
NEBULOUS. LATEST GUIDANCE TRENDS FROM THE NAM AND GGEM INDICATE A
POSSIBLE NEARLY STATIONARY FRONTAL BOUNDARY DRAPED OVER THE AREA
WITH WEAK WAVES OF LOW PRESSURE MOVING ALONG THE BOUNDARY. THIS
WOULD RESULT IN A COOLER AND CLOUDIER FORECAST FOR FRIDAY.
HOWEVER...THE GFS CONTINUES TO INDICATE OUR REGION WILL BE IN A
WARM SECTOR AHEAD OF A PRE-FRONTAL TROUGH AND COLD FRONT ATTACHED
TO A STRONGER LOW DROPPING SOUTHEASTWARD THROUGH QUEBEC. THIS
SOLUTION WOULD IMPLY MUCH WARMER TEMPS...MORE IN THE WAY OF
SUNSHINE AND ALSO BETTER CHANCES FOR POTENTIALLY STRONG
CONVECTION. BASED ON THE GFS BEING AN OUTLIER AT THIS POINT...WILL
SIDE WITH THE NAM/GGEM AND ECMWF SOLUTION WITH A COOLER AND
CLOUDIER DAY FOR FRIDAY. STILL RELATIVE TO NORMAL IT WILL BE
WARM...BUT WILL FORECAST TEMPS A GOOD 10 DEGREES COOLER THAN THE
GFS MEX GUIDANCE. THIS COULD END UP CHANGING AS THE WEEK
PROGRESSES.
WHICH EVER TYPE OF SYSTEM AFFECTS THE REGION ON FRIDAY...THERE IS AT
LEAST LOOSE CONSENSUS FOR A NORTHERN STREAM TROUGH TO DIG
SOUTHWARD INTO EASTERN CANADA FRIDAY NIGHT INTO SATURDAY...WHICH
WOULD PUSH THROUGH EITHER THE WEAK WAVE/STATIONARY FRONT OR A
STRONGER CYCLONE. WILL MENTION CHANCE POPS FOR FRIDAY NIGHT INTO
SATURDAY WITH TEMPS STILL REMAINING WARM. DRYING APPEARS POSSIBLE
FOR LATE SATURDAY NIGHT INTO SUNDAY...BUT A LOT DEPENDS ON HOW THE
PATTERN EVOLVES PRIOR TO THE WEEKEND.
WILL MENTION DRY WEATHER AND NEAR NORMAL TEMPS THROUGH EARLY NEXT
WEEK WITH A DRY NORTHERLY FLOW OVER THE AREA DEPICTED BY MOST OF THE
MEDIUM RANGE GUIDANCE.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
MVFR-IFR OVC WAS HANGING TOUGH WITH NO BIG SIGN OF IMPROVEMENT. A
WARM FRONT LIFTING THROUGH PENNSYLVANIA WILL LIKELY STAY WELL WEST
OF THE AIRPORTS THROUGH WEDNESDAY MORNING...RESULTING IN LIGHT
SURFACE WINDS UNDER 7 KNOTS...AND CONTINUED MVFR OVC...WITH SOME
MVFR FOG TOWARD MORNING AS RATHER MOIST DEW POINTS ADVECT IN OFF
THE OCEAN WITH THE FLOW BEING LIGHT SOUTHERLY. WINDS UP TO 2000
FEET WILL BE MAINLY UNDER 15 KNOTS.
.OUTLOOK...
.WED AFTN-THU...MAINLY VFR...CHC -SHRA.
.THU NIGHT-SAT ...MAINLY VFR. CHC -SHRA OR -TSRA.
&&
.FIRE WEATHER...
MINIMAL FIRE WEATHER CONCERNS AS PRECEDING RAINFALL WAS BENEFICIAL
FOR THE REGION. AS THE COMBINATION OF INCREASING MOISTURE AND
COMPETING CLOUD COVER WILL MAKE FOR ELEVATED RELATIVE HUMIDITIES
AND MINIMAL VALUES ON THE HAINES INDEX FOR THE BALANCE OF THE
WEEK.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED THIS WEEK. WHILE CONFIDENCE IN THE
OVERALL EXPECTATIONS OF CONVECTIVE ACTIVITY ARE LOW...WITH LAKE AND
RIVER LEVELS REMAINING QUITE LOW...QPFS ARE EXPECTED TO REMAIN AT
OR BELOW 1 INCH PER THE BASIN AVERAGE.
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.
&&
.CLIMATE...
ALBANY NY:
APRIL AVERAGE TEMPERATURE: 48.1 DEGREES (+0.3 DEGREES)
PRECIPITATION:
APRIL 2012: 2.97 INCHES (-0.20 INCHES)
SINCE MAR 1: 4.51 INCHES (-1.87 INCHES)
SINCE JAN 1: 7.77 INCHES (-3.40 INCHES)
GLENS FALLS NY:
APRIL AVERAGE TEMPERATURE: 45.2 DEGREES (+0.7 DEGREES)
PRECIPITATION:
APRIL 2012: 2.69 INCHES (-0.31 INCHES)
SINCE MAR 1: 3.92 INCHES (-2.02 INCHES)
SINCE JAN 1: 6.86 INCHES (-4.02 INCHES)
POUGHKEEPSIE NY:
APRIL AVERAGE TEMPERATURE: 50.1 DEGREES (+1.4 DEGREES)
PRECIPITATION:
APRIL 2012: 2.06 INCHES (-1.72 INCHES)
SINCE MAR 1: 3.25 INCHES (-4.10 INCHES)
SINCE JAN 1: 6.86 INCHES (-6.23 INCHES)
BENNINGTON VT:
APRIL AVERAGE TEMPERATURE: 45.6 DEGREES (+0.1 DEGREES)
PRECIPITATION:
APRIL 2012: 2.18 INCHES (-1.09 INCHES)
SINCE MAR 1: 3.76 INCHES (-2.66 INCHES)
SINCE JAN 1: 6.26 INCHES (-5.15 INCHES)
PITTSFIELD MA:
APRIL AVERAGE TEMPERATURE: 45.7 DEGREES (+1.5 DEGREES)
PRECIPITATION:
APRIL 2012: 1.83 INCHES (-2.03 INCHES)
SINCE MAR 1: 2.97 INCHES (-4.26 INCHES)
SINCE JAN 1: 7.18 INCHES (-5.65 INCHES)
FOR MORE GO TO OUR CLIMATE PAGE AT:
WWW.NWS.NOAA.GOV/CLIMATE/LOCAL_DATA.PHP?WFO=ALY
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...JPV
AVIATION...ELH
FIRE WEATHER...BGM
HYDROLOGY...BGM
CLIMATE...IAA
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
145 PM EDT TUE MAY 1 2012
.SYNOPSIS...
18Z WATER VAPOR AND H4 RUC ANALYSIS SHOWS AN UNAMPLIFIED UPPER
LEVEL PATTERN ACROSS THE CONUS...WITH A NORTHERN STREAM FLOW IN A
MORE-OR-LESS ZONAL CONFIGURATION FROM WEST TO EAST. THE MOST
SIGNIFICANT "KINK" IN THE FLOW IS ASSOCIATED WITH A SHORTWAVE
DIGGING THROUGH THE INTER-MOUNTAIN WEST. THIS ENERGY WILL EJECT
EASTWARD TOWARD THE HIGH PLAINS/UPPER MS VALLEY THIS EVENING
BRINGING THE THREAT FOR STRONG TO SEVERE THUNDERSTORMS. CLOSER TO
HOME...THE UPPER LEVEL DISTURBANCE WHICH HAS BEEN PARKED OVER
SOUTHERN FL/BAHAMAS THE PAST SEVERAL DAYS IS FINALLY WEAKENING AND
TRANSLATING EASTWARD. IN ITS WAKE...WEAK UPPER LEVEL RIDGING IS
TRYING TO BUILD OVER THE PENINSULA. 12Z KTBW SOUNDING PROFILE A
WETTER THAN NORMAL PROFILE WITH A PW VALUE OVER 1.5". DUE TO THE
EXTRA MOISTURE IN THE COLUMN...CAN NOT RULE OUT A FEW SHOWERS LATE
AFTERNOON/EARLY EVENING UP INTO THE TAMPA BAY AREA...HOWEVER THE
SYNOPTIC FLOW SHOULD PREVENT THE DEVELOPMENT OF THE WEST COAST
SEA-BREEZE. THIS LACK OF LOW LEVEL FOCUS AND FADING SYNOPTIC SUPPORT
ALOFT WILL HELP TO KEEP RAIN CHANCES ON THE LOW SIDE. MORE FAVORED
AREAS FOR SHOWERS THE REST OF THE DAYLIGHT HOURS WILL BE DOWN TOWARD
THE FORT MYERS REGION WHERE COLUMN MOISTURE IS EVEN HIGHER.
AT THE SURFACE...FORECAST AREA RESIDES BETWEEN HIGH PRESSURE OFF THE
GEORGIA COAST...AND A WEAK AREA OF LOW PRESSURE MIGRATING WESTWARD
ACROSS THE SOUTH-CENTRAL GULF OF MEXICO. GRADIENT IS STILL RATHER
TIGHT BETWEEN THESE 2 FEATURES KEEPING CONDITIONS ON THE BREEZY
SIDE...ESPECIALLY OVER CENTRAL AND SOUTHERN PORTIONS OF THE FORECAST
AREA. SMALL CRAFT ADVISORY WILL REMAIN UP UNTIL 5 PM EDT ACROSS THE
MARINE AREA FROM ENGLEWOOD TO TARPON SPRINGS.
&&
.SHORT TERM (TONIGHT THROUGH THURSDAY)...
TONIGHT...A FEW EVENING SHOWERS ALONG/NEAR THE COAST FROM TAMPA
SOUTHWARD WILL PUSH OFFSHORE DURING THE EVENING HOURS LEAVING A
GENERALLY DRY FORECAST FOR OUR LAND ZONES DURING MUCH OF THE
OVERNIGHT. TEMPERATURES WILL THE SIMILAR TO PAST NIGHTS WITH LOWS BY
SUNRISE RANGING FROM THE MIDDLE/UPPER 60S INLAND AND NORTH TO THE
LOWER 70S COASTAL AND SOUTH.
WEDNESDAY...
FORECAST AREA WILL FIND ITSELF UNDER STACKED RIDGING. A WEAKER
EASTERLY FLOW WILL PERSIST ON THE SOUTH SIDE OF THE SUBTROPICAL
RIDGE AXIS. GFS/NAM/ECMWF ALL SHOW THE UPPER RIDGE BECOMING A BIT
MORE DOMINANT OVERHEAD AND ALLOWING A DRIER COLUMN TO DEVELOP. THIS
PATTERN WILL LIKELY ALLOW FEEBLE SEA-BREEZE CIRCULATIONS TO DEVELOP
BUT HOLD THESE FEATURES AT THE SHORELINE. BEST RESIDUAL DEEP LAYER
MOISTURE WILL BE CLOSER TO THE COAST IN PROXIMITY TO THE SEA-BREEZE
FOCUS AND THEREFORE CAN`T RULE OUT A FEW ISOLATED SHOWERS...HOWEVER
ONLY GOING WITH A SLIGHT CHANCE 20% POP...AND MOST LOCATIONS WILL
REMAIN RAIN FREE. THE DEEP LAYER SUPPRESSION UNDER THE RIDGE AND
LACK OF CONVECTION SHOULD ALLOW TEMPERATURES TO GET QUITE WARM.
CURRENT GRIDS SHOWING HIGH TEMPERATURES WITHIN A DEGREE OR 2 OF 90
BY MID AFTERNOON WITH LOWER/MID 80S AT THE BEACHES.
THURSDAY...OVERALL SYNOPTIC PATTERN WILL BE SIMILAR TO WEDNESDAY.
PRESSURE GRADIENT WILL RELAX SOMEWHAT AND THE HI-RES GUIDANCE
MEMBERS ARE RESPONDING BY PRODUCING WELL-DEFINED SEA-BREEZE
CIRCULATIONS ALONG THE COAST IN THE AFTERNOON. THE LOW LEVEL FOCUS
ASSOCIATED WITH THESE SEA-BREEZES WILL BE MORE PRONOUNCED...BUT AT
THE SAME TIME...THE OVERALL COLUMN WILL HAVE FURTHER DRIED OUT. IN
FACT...GFS IS SHOWING MID-LEVEL THETAE VALUES OF 317-320K...WHICH
RESEARCH HAS SHOWN TO BE RATHER HOSTILE TO THE DEVELOPMENT OF DEEP
CONVECTION. WITH THIS IN MIND WILL KEEP THE RAIN CHANCES QUITE LOW
(10-20%). TEMPERATURES WILL AGAIN BE QUITE HOT WITH HIGHS AROUND 90
AWAY FROM THE IMMEDIATE COAST.
&&
.LONG TERM (FRIDAY THROUGH MONDAY)...
THE GLOBAL MODELS ARE SIMILAR TO PREVIOUS RUNS OVER THE LAST DAY
OR SO. AN UPPER LEVEL RIDGE OVER THE SE U.S AND A SHORT WAVE TROUGH
SOMEWHERE OVER THE GULF OR GULF COASTAL REGION SLOWLY SHIFTS WEST
DURING THE PERIOD AS AN UPPER TROUGH MOVES INTO WESTERN ATLANTIC
WATERS...OFF THE EAST U.S. COAST. MEANWHILE AT THE SURFACE...A RIDGE
OF HIGH PRESSURE FROM THE OPEN ATLANTIC...ACROSS GA/FL...TO THE
CENTRAL GULF COAST WILL INITIALLY DRIFT WESTWARD. THEN DURING THE
WEEKEND A WEAK FRONTAL BOUNDARY SAGS IN ACROSS THE GULF COAST AND
SE STATES...PUSHING THE RIDGE AXIS SOUTH.
SOME DIFFERENCES IN THE MODEL SOLUTIONS CONTINUE WITH RESPECT TO
LOCATION...TIMING...AND MOISTURE. PREFER TO MAINTAIN THE CURRENT
TREND IN THE FORECAST. PARTLY CLOUDY WITH A SLIGHT CHANCE OF DAYTIME
THUNDERSTORMS...MAINLY IN THE AFTERNOONS. TEMPERATURES WILL BE NEAR
OR JUST ABOVE NORMAL...BY PERHAPS A COUPLE OF DEGREES AT TIMES. AS
THE HIGH MOVES WEST AND THEN SOUTH THE GRADIENT WILL RELAX AND ALLOW
SEA BREEZE CIRCULATIONS FOR THE AFTERNOONS.
&&
.AVIATION...
PREDOMINANTLY VFR WITH SOME SHRA WITH BRIEF MVFR POSSIBLE AT
PGD...FMY AND RSW. GUSTY WINDS DIMINISH TO 8 TO 10 KNOTS OVERNIGHT
THEN INCREASE AGAIN AFTER SUNRISE WEDNESDAY.
&&
.MARINE...
WINDS AND SEAS WILL DROP BELOW ADVISORY LEVELS IN THE NEXT FEW
HOURS...ALTHOUGH PERIODS OF CAUTIONARY LEVEL WINDS WILL REMAIN
POSSIBLE INTO WEDNESDAY MORNING BEFORE SUBSIDING FOR THE AFTERNOON.
ANOTHER EASTERLY SURGE WILL BE POSSIBLE TO NEAR CAUTIONARY LEVELS
WEDNESDAY NIGHT. A WEAKENING GRADIENT WILL THEN DROP WINDS BELOW
HEADLINE CRITERIA FOR THE END OF THE WEEK.
&&
.FIRE WEATHER...
EASTERLY FLOW WILL CONTINUE TO PROVIDE LOW LEVEL ATLANTIC MOISTURE
INTO THE MIDDLE OF THE WEEK. RELATIVE HUMIDITY VALUES ARE EXPECTED
TO REMAIN ABOVE 35% ON WEDNESDAY. A FEW SPOTS BY BRIEFLY DROP TO
NEAR CRITICAL RELATIVE HUMIDITY LEVELS THURSDAY AND FRIDAY
AFTERNOONS AWAY FROM THE COAST...HOWEVER RED FLAG CRITERIA ARE NOT
ANTICIPATED TO BE MET.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 70 89 70 88 / 15 20 5 15
FMY 69 88 69 87 / 20 20 10 15
GIF 68 90 66 90 / 5 10 5 10
SRQ 70 87 70 85 / 20 20 10 15
BKV 67 90 66 89 / 15 20 5 10
SPG 71 87 71 86 / 15 20 10 15
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR
BONITA BEACH TO ENGLEWOOD OUT 20 NM-BONITA BEACH TO
ENGLEWOOD OUT 20 TO 60 NM-ENGLEWOOD TO TARPON SPRINGS
OUT 20 NM-ENGLEWOOD TO TARPON SPRINGS OUT 20 TO 60 NM.
&&
$$
SYNOPSIS/SHORT TERM/MARINE...MROCZKA
AVIATION/FIRE WEATHER...JILLSON
LONG TERM...RUDE
AREA FORECAST DISCUSSION
NWS LINCOLN IL
303 PM CDT TUE MAY 1 2012
.DISCUSSION...
ISSUED 300 PM CDT TUE MAY 1 2012
A WET BIAS IS INDICATED IN ALL OF THE DETERMINISTIC MODELS AS A
FRONTAL BOUNDARY LIFTS NORTH AS A WARM FRONT TONIGHT...THEN LINGERS
JUST W-NW OF ILLINOIS FOR MUCH OF THE WEEK BEFORE RETURNING AS A
COLD FRONT LATER IN THE WEEKEND. A WARM AND HUMID AIRMASS WILL
DEVELOP OVER C IL TOMORROW BEHIND THE WARM FRONT. THAT SUMMER-
TIME TYPE OF AIRMASS WILL BE RIPE FOR ANY UPPER SHORTWAVES AND
LINGERING SURFACE BOUNDARIES TO BECOME ACTIVE WITH STORMS WHEN ANY
ELEVATED MIXED LAYERS BECOME UNSTABLE ENOUGH FOR SUSTAINED
UPDRAFTS. THE END RESULT IS AN ABUNDANCE OF PRECIP CHANCES
PEPPERED THROUGHOUT THE NEXT 7 DAYS...BUT CONFIDENCE ON RAIN/STORM
COVERAGE IN GENERAL IS LOW.
SHORT TERM...TONIGHT THROUGH THURSDAY.
THE WARM FRONT IS CURRENTLY EXTENDING FROM LOW PRESSURE NEAR
FULTON COUNTY TO THE SE TOWARD TERRE HAUTE. AN MCV ASSOCIATED WITH
THE SURFACE LOW WILL HELP TRIGGER ADDITIONAL SHOWERS AND A FEW
STORMS ACROSS THE NORTH INTO THE EVENING. ADDITIONAL STORMS WILL
BE POSSIBLE ACROSS THE SOUTH INTO THE EVENING AS THE SOUTHERN
PERIPHERY OF THE MCV REMAINS ACTIVE WHERE SUNSHINE WAS MORE
PLENTIFUL TODAY. WE KEPT SLIGHT CHANCE POPS IN ALL AREAS TONIGHT
TO ACCOUNT FOR VARIOUS CONVECTIVE ELEMENTS THAT MAY FESTER UNDER
THE ADVANCING WARM FRONT IN THE NORTH AND THE POST MCV AIRMASS IN
THE SOUTH.
IN OUR COUNTIES...WEDNESDAY SHOULD BE CAPPED WITH WARM AIR ALOFT
FOR MOST OF THE DAY. OUR NORTHERN COUNTIES ARE IN THE DAY 2
SLIGHT RISK FOR SEVERE STORMS...CLOSER TO THE LINGERING WARM
FRONT. THE HRRR MODEL IS SHOWING AN ADVANCING STORM COMPLEX LATER
TONIGHT ACROSS MN/IA. THAT SYSTEM MAY PUT DOWN AN ADDITIONAL
BOUNDARY FROM THE COLD POOL THAT DRIFTS EAST TOWARD IL WED
MORNING. IT MAY BECOME ACTIVE AS PEAK HEATING CREATES SURFACE
BASED INSTABILITY. EVEN IF MORNING CLOUDS AND FOG LINGER IN THAT
AREA THROUGH THE MORNING...ANY EARLY AFTERNOON CLEARING WILL
ALLOW FOR RAPID DESTABILIZATION OF THE AIRMASS IN FAR NW IL AND
AREAS TO THE W-NW NEAR THE WARM FRONT. IF THE CAP BREAKS TO THE
NW...THE STORMS MAY MAINTAIN SEVERE LEVELS INTO SOME OF OUR
COUNTIES...BUT THE FARTHER E-SE THEY PROGRESS INTO THE CAPPED
AIRMASS...THEY SHOULD LOSE SOME STRENGTH. THEREFORE WE ONLY HAVE
SLIGHT CHANCE POPS IN OUR NORTHERN COUNTIES WED/WED NIGHT.
THURSDAY MAY BE A SIMILAR SCENARIO TO WEDNESDAY...AS THE WARM
FRONT/STATIONARY FRONT REMAINS IN PLACE TO OUR NW. OUR NW COUNTIES
ARE IN THE DAY 3 SLIGHT RISK FOR SEVERE STORMS AGAIN AS A RESULT.
NEAR RECORD HIGHS IN THE MID TO UPPER 80S ARE EXPECTED WED AND
THUR AS DEWPOINTS CLIMB INTO THE MID 60S. IT WILL BE AN
UNCOMFORTABLE AIRMASS AFTER THE RELATIVELY COOLER PORTIONS OF
APRIL.
LONG TERM...THURSDAY NIGHT THROUGH TUESDAY.
STORM CHANCES WILL INCREASE FROM NW TO SE ON THURSDAY NIGHT AS LOW
PRESSURE MOVES FROM THE DAKOTAS INTO THE GREAT LAKES...DRAGGING A
COLD FRONT TOWARD NW IL. STORM CHANCES WILL CONTINUE FRI AND FRI
NIGHT AS THE FRONT STALLS OUT ACROSS SOUTH CENTRAL IL. SATURDAY
MAY SEE A BREAK IN THE ACTION BUT SLIGHT CHANCES WILL CONTINUE DUE
TO THE PROXIMITY OF THE FRONT AND 500MB SHORTWAVES.
HIGHER CHANCES OF SHOWERS AND STORMS WILL DEVELOP LATER SUNDAY
INTO MONDAY AS THE NEXT LOW PRESSURE CENTER MOVES FROM THE CENTRAL
PLAINS INTO C IL ALONG THE FRONT. A COOLER AIRMASS WILL TRY TO
DROP SOUTH INTO OUR PORTION OF IL ON MONDAY NIGHT AND TUESDAY...AS
HIGH PRESSURE FROM CANADA BUILDS SOUTHWARD. SO WE WENT WITH A
COOLING TREND FOR MON AND TUES...WITH TUES HIGHS REMAINING IN THE
60S.
SHIMON
&&
.AVIATION...
ISSUED 1254 PM CDT TUE MAY 1 2012
LOW-LEVEL CIRCULATION ASSOCIATED WITH OVERNIGHT/EARLY MORNING
CONVECTIVE COMPLEX WILL LIFT NORTHWARD THROUGH THE ILLINOIS RIVER
VALLEY THIS AFTERNOON. TO THE N/NW OF ITS TRACK...WINDS WILL
REMAIN FROM THE EAST AT KPIA FOR THE NEXT COUPLE OF HOURS...THEN
WILL BECOME LIGHT/VARIABLE AS THE FEATURE MOVES NEARBY. ELSEWHERE
AROUND CENTRAL ILLINOIS...SOUTHEASTERLY WINDS WILL BECOME
SOUTHERLY AS A WARM FRONT LIFTS NORTHWARD THROUGH THE AREA. HIGH
RES MODELS SUCH AS THE HRRR SUGGEST WIDELY SCATTERED STORMS
RE-DEVELOPING IN THE WARM SECTOR THIS AFTERNOON...HOWEVER
CONFIDENCE IS TOO LOW TO INCLUDE IN FORECAST AT THIS TIME. FURTHER
NORTHWEST IN CLOSER PROXIMITY TO THE CIRCULATION CENTER...RADAR
LOOPS SUGGEST PERIODIC SHOWERS AT KPIA THROUGH ABOUT 21Z. PRECIP
CHANCES DIMINISH AND SKIES BECOME PARTLY TO MOSTLY CLEAR ACROSS
THE BOARD THIS EVENING...AS WARM FRONT PUSHES INTO NORTHERN
ILLINOIS. DUE TO AMPLE LOW-LEVEL MOISTURE AND HUMID SOUTHERLY FLOW
IN ITS WAKE...MAY SEE SOME FOG AT THE TERMINALS OVERNIGHT. WINDS
OF AROUND 10KT WILL LIKELY PREVENT WIDESPREAD DENSE FOG...HOWEVER
HAVE DROPPED VISBYS TO AROUND 3SM AFTER 09Z. ANY FOG WILL
DISSIPATE BY EARLY WEDNESDAY MORNING...FOLLOWED BY MOSTLY CLEAR
SKIES AND GUSTY S/SW WINDS.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1254 PM CDT TUE MAY 1 2012
.DISCUSSION...
ISSUED 929 AM CDT TUE MAY 1 2012
BAND OF SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A WELL-DEFINED
MCV OVER NORTHERN MISSOURI CONTINUES TO LIFT NORTHEASTWARD ACROSS
CENTRAL/SOUTHEAST ILLINOIS THIS MORNING. BASED ON RADAR TIMING
TOOLS...MAIN PRECIP AREA WILL BE TO THE N/NE OF THE KILX CWA BY
MIDDAY. IN THE WAKE OF THE MORNING WAVE OF PRECIP...ADDITIONAL
CONVECTION MAY FIRE ALONG/AHEAD OF THE ADVANCING MCV. DUE TO
STABILIZING INFLUENCE OF MORNING PRECIP...THINK AREAL COVERAGE OF
ANY AFTERNOON STORMS WILL BE SCATTERED AT BEST. HAVE THEREFORE
ADJUSTED RAIN CHANCES TO BETTER REFLECT CURRENT TRENDS...FEATURING
CATEGORICAL POPS THIS MORNING...THEN ONLY CHANCE POPS THIS
AFTERNOON. HAVE ALSO TWEAKED HOURLY TEMPS...AS CLOUDS/RAIN WILL
KEEP READINGS IN THE 50S AND 60S THROUGH MIDDAY...BEFORE DRIER
CONDITIONS AND AN INCREASING SOUTHERLY WIND HELP TEMPS SOAR INTO
THE 70S BY MID TO LATE AFTERNOON. ZONE UPDATE HAS ALREADY BEEN
ISSUED.
&&
.AVIATION...
ISSUED 1254 PM CDT TUE MAY 1 2012
LOW-LEVEL CIRCULATION ASSOCIATED WITH OVERNIGHT/EARLY MORNING
CONVECTIVE COMPLEX WILL LIFT NORTHWARD THROUGH THE ILLINOIS RIVER
VALLEY THIS AFTERNOON. TO THE N/NW OF ITS TRACK...WINDS WILL
REMAIN FROM THE EAST AT KPIA FOR THE NEXT COUPLE OF HOURS...THEN
WILL BECOME LIGHT/VARIABLE AS THE FEATURE MOVES NEARBY. ELSEWHERE
AROUND CENTRAL ILLINOIS...SOUTHEASTERLY WINDS WILL BECOME
SOUTHERLY AS A WARM FRONT LIFTS NORTHWARD THROUGH THE AREA. HIGH
RES MODELS SUCH AS THE HRRR SUGGEST WIDELY SCATTERED STORMS
RE-DEVELOPING IN THE WARM SECTOR THIS AFTERNOON...HOWEVER
CONFIDENCE IS TOO LOW TO INCLUDE IN FORECAST AT THIS TIME. FURTHER
NORTHWEST IN CLOSER PROXIMITY TO THE CIRCULATION CENTER...RADAR
LOOPS SUGGEST PERIODIC SHOWERS AT KPIA THROUGH ABOUT 21Z. PRECIP
CHANCES DIMINISH AND SKIES BECOME PARTLY TO MOSTLY CLEAR ACROSS
THE BOARD THIS EVENING...AS WARM FRONT PUSHES INTO NORTHERN
ILLINOIS. DUE TO AMPLE LOW-LEVEL MOISTURE AND HUMID SOUTHERLY FLOW
IN ITS WAKE...MAY SEE SOME FOG AT THE TERMINALS OVERNIGHT. WINDS
OF AROUND 10KT WILL LIKELY PREVENT WIDESPREAD DENSE FOG...HOWEVER
HAVE DROPPED VISBYS TO AROUND 3SM AFTER 09Z. ANY FOG WILL
DISSIPATE BY EARLY WEDNESDAY MORNING...FOLLOWED BY MOSTLY CLEAR
SKIES AND GUSTY S/SW WINDS.
BARNES
&&
.PREV DISCUSSION...
ISSUED 356 AM CDT TUE MAY 1 2012
WEAK HIGH PRESSURE DOMINANCE SLOWLY COMING TO AN END AS ANOTHER
UPPER LEVEL DISTURBANCE AND CONVECTIVE COMPLEX SLOWLY MAKES ITS
WAY THROUGH THE PLAINS AND INTO THE MIDWEST THIS MORNING. STRONG
WAA STILL KEEPING THE TEMPS UP THROUGHOUT THE ENTIRE FORECAST PD.
INHERITED FORECAST A COMPILATION OF MANY CHANCE POPS IN A RATHER
ACTIVE WEATHER PATTERN AND SEVERAL WAVES PUSHING OUT IN
INCREASINGLY SWRLY FLOW THROUGH THE WEEKEND UNTIL A MAJOR TROF
DIGS INTO THE WESTERN COAST. WITH LARGE SCALE PATTERN SHIFTS...
MODELS HAVING A DIFFICULT TIME WITH WAVE STRENGTH AND TIMING.
FORECAST VERY MUCH A BLEND...WITH LITTLE CHANGES MADE HERE AND
THERE TO TREND OUT SMALL POPS WHERE POSSIBLE.
SHORT TERM...TODAY AND TOMORROW...
PRECIP SPREADING NORTHWARD INTO CWA THIS MORNING RESULTING IN POPS
THROUGH MIDDAY...BUT SHOWERS ALREADY WEAKENING SOMEWHAT ON
APPROACH TO THE MISS RIVER VALLEY INTO THE RIDGE AXIS.
REDEVELOPMENT AND AFTERNOON HEATING WILL PLAY A ROLE IN PRECIP FOR
THE SECOND HALF OF THE DAY...THOUGH THE CLOUD COVER ASSOCIATED
SHOULD MITIGATE THE HEATING. WARM AIR AND INCREASINGLY SOUTHERLY
FLOW AT THE SFC WILL RESULT IN AN EVEN WARMER DAY TOMORROW...AND A
FRONT LIFTING THROUGH THE CWA THROUGH OVERNIGHT HOURS INTO
TOMORROW. BOUNDARY IS MOST PRONOUNCED JUST TO THE NORTH OF THE
CWA...WITH POPS IN THE NRN TIER OF THE STATE FOR TOMORROW AND
TOMORROW EVENING. THIS IS A BIT OF A SHIFT NORTHWARD FROM THE LAST
FEW FORECASTS.
LONG TERM...THURSDAY THROUGH MONDAY...
THOUGH INITIAL SYSTEM LIFTS OUT TO THE EAST...A TROF STARTING TO DIG
INTO THE PAC COAST EJECTS OUT SEVERAL SHORTWAVES THROUGH THE
INCREASINGLY SOUTHWESTERLY FLOW ALOFT...LIGHTING UP A SERIES OF
SHOWER/TS SCENARIOS THROUGH THE LATTER HALF OF THE WEEK AND INTO
THE WEEKEND...ALONG A SFC TROF/BOUNDARY REMAINING OVER THE NRN
TIER OF THE STATE...ALONG THE SAME SW/NE TRAJECTORY. MODEL QPF
STARTING TO SHIFT FURTHER NORTH IN ALL SOLUTIONS. THE TRACK OF
THE WAVES THEMSELVES IS STILL A BIT OF A QUESTION MARK...AND
LEAVING ENOUGH UNCERTAINTY THAT POPS ARE LOW AND NEVER FAR
AWAY...EVEN WITHIN THE EXTENDED. UNSEASONABLY WARM AND MUGGY TEMPS
DOMINATE THE EXTENDED AS WELL...WITH GUIDANCE WELL INTO THE 80S
AND DEWPOINTS IN THE 60S...WHICH WILL ONLY BE ENHANCED BY
LOCALIZED SHOWERS AND THUNDERSTORMS IN THE ACTIVE WAVE TRAIN.
HJSCLS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...CORRECTED
NWS NORTHERN INDIANA
319 PM EDT TUE MAY 1 2012
.SHORT TERM...
MANY ISSUES TO SORT OUT IN THE SHORT TERM. MCV MOVING ACROSS THE
REGION TODAY HAS BEEN HANDLED BEST BY HRRR WITH OTHER HI RES
GUIDANCE IN BALLPARK BUT NOT NEAR AS FAST MOVING THIS WAVE
NORTHEAST. HAVE FOLLOWED HRRR FOR GUIDANCE IN THE SHORT TERM. SHOULD
SEE BULK OF PCPN MOVE EAST BEFORE 00Z WITH LINGERING SHOWERS AND FEW
THUNDERSTORMS FAR EAST AFTER 00Z. MEANWHILE...SOME DEVELOPMENT
POSSIBLE SOUTH OF MCV TRACK IN AREA OF INCREASING INSTABILITY LATE
THIS AFTERNOON WHICH COULD MOVE THROUGH CENTRAL AND NORTHERN AREAS
THIS EVENING. PREVIOUS GRIDS HAD LIKELY POPS ALL NIGHT AND THIS
SEEMS OVERDONE GIVEN FASTER ARRIVAL OF MCV AND INCREASING STABILITY
OVERNIGHT. HAVE ADJUSTED GRIDS FOR HIGHER POPS THIS EVENING BUT KEPT
CHANCE POPS OVERNIGHT WITH BOUNDARY IN THE AREA.
NEXT ISSUE IS WITH DEVELOPMENT OF AN MCS OVERNIGHT TO OUR NW AND
TRACK IT WOULD TAKE TOWARD DAYBREAK. NAM12 BRINGS SOUTHERN FRINGE OF
THIS SYSTEM ACROSS NORTHERN AREAS AROUND 12Z WITH GFS SIMILAR. HI
RES WRF NMM ALSO HINTS AT NORTHERN AREAS BEING BRUSHED BY CONVECTION
EARLY WED MORNING. THIS WARRANTS A SLIGHT NUDGE IN POPS EARLY
WEDNESDAY BUT CONFINED TO MID CHANCE RANGE GIVEN MCS UNCERTAINTY.
NAM AND WRF LAY A BOUNDARY OUT ACROSS CENTRAL CWA WEDNESDAY WHICH
THEN CONVECTS IN THE AFTERNOON WITH GROWING INSTABILITY. THIS
INSTABILITY IS CONTINGENT ON CLOUDS BREAKING UP AND AFTERNOON
HEATING BUT WITH SYNOPTIC WARM FRONT WELL NORTH AND STRONG SOUTHWEST
FLOW ALOFT THIS LOOKS PLAUSIBLE. RESULT WOULD BE TSRA DEVELOPMENT
FARTHER SOUTH IN CENTRAL CWA SO HAVE BROUGHT POPS BACK INTO THIS
AREA FOR THE AFTERNOON HOURS. SEVERE THUNDERSTORMS WOULD BE POSSIBLE
GIVEN MARGINAL BULK SHEAR BUT POTENTIALLY LARGE MUCAPE AND HIGH PWAT
VALUES.
TEMPS WILL BE VERY TRICKY WITH VERY WARM AND HUMID AIRMASS IN PLACE
BUT CONVECTIVE DEBRIS AND PCPN LIMITING FACTORS FOR MAX HEATING. ALL
BLEND USED FOR TEMPERATURES THROUGH THE SHORT TERM PERIOD AS THEY
ARE A NICE COMPROMISE BUT CERTAINLY COULD BE A LITTLE WARMER OR
COOLER DEPENDING ON AMOUNT OF SUN.
&&
.LONG TERM...THURSDAY THROUGH MONDAY
PERIOD TO BEGIN WITH SUBTLE HEIGHT RISES ACROSS THE UPPER
MIDWEST/NORTHERN GREAT LAKES AS MORE SIGNIFICANT SHORT WAVE UPPER
TROUGH AXIS TRACKS INTO THE PACIFIC NORTHWEST. THIS WILL RESULT IN
WARM FRONT TO CONTINUE TO SURGE NORTHWARD ACROSS THE GREAT LAKES
REGION ON THURSDAY. GENERALLY CAPPED CONDITIONS ARE ANTICIPATED
ACROSS APPROXIMATELY SOUTHERN TWO THIRDS OF THE FORECAST AREA WITH
MAIN QUESTION ON PRECIP CHANCES ACROSS THE FAR NORTH WHERE CAP WILL
LIKELY BE WEAKER. DIFFICULT AT THIS FORECAST DISTANCE TO LATCH ONTO
STRONGER PERIODS OF MID/UPPER LEVEL FORCING WITH MAIN SHORT WAVE
TRACK REMAINING WITH STRONGER BELT OF WESTERLIES FROM THE NORTHERN
PLAINS INTO THE UPPER GREAT LAKES. SEE NO REASON TO DEVIATE FROM
PREVIOUS FORECAST AT THIS TIME WITH LATE AFTERNOON LOW CHANCE TSRA
POPS ACROSS THE FAR NORTH GIVEN AFOREMENTIONED THERMODYNAMIC
PROFILES.
THE MORE PRONOUNCED PACIFIC WAVE IS THEN EXPECTED TO TRACK ACROSS
SOUTHWEST ONTARIO BY THURSDAY NIGHT INTO FRIDAY EVENTUALLY ALLOWING
COLD FRONT TO SHIFT EASTWARD. STRONGER FRONTAL CONVERGENCE MAY BE
CONFINED TO AREAS FURTHER NORTH ACROSS THE GREAT LAKES IN CLOSER
PROXIMITY TO STRONGER UPPER FORCING. HOWEVER WITH MODERATE
INSTABILITY PRECEDING THE FRONT WILL CONTINUE WITH MID RANGE
CHANCE POPS THURSDAY NIGHT THROUGH FRIDAY ACROSS ENTIRE FORECAST
AREA. SEVERE POTENTIAL STILL UNCLEAR FOR THURSDAY NIGHT/FRIDAY DUE
TO UNCERTAINTIES REGARDING UPSTREAM CONVECTION AND IMPACTS ON
INSTABILITY FOR THE LOCAL AREA ALONG WITH WHAT SHOULD BE MORE
MARGINAL DEEP LAYER SHEAR PROFILES FOR THIS PERIOD. NO SIGNIFICANT
CHANGES MADE TO VERY WARM TEMPERATURES IN ADVANCE OF THE FRONT
THURSDAY AFTERNOON WITH HIGHS IN THE MID TO UPPER 80S.
ON SATURDAY...ELONGATED SFC RIDGE AXIS TO BUILD INTO GREAT LAKES
REGION BEHIND THIS BOUNDARY...WITH SLIGHTLY MORE STABLE CONDITIONS.
PRECIP CHANCES ARE BECOMING MORE MUDDLED WITH BETTER ISENTROPIC
UPGLIDE OVER BOUNDARY POSSIBLY REMAINING JUST WEST OF THE AREA
ACROSS MID MS RVR VALLEY. CANNOT DISCOUNT ISOLD/SCT SHRA/TSRA
HOWEVER DUE TO PERSISTENT ELEVATED INSTABILITY. PERHAPS A SLIGHTLY
BETTER CHANCE FOR LATE SUNDAY/SUNDAY EVENING WHEN MID LEVEL RIDGE
IS EXPECTED TO SHIFT SLIGHTLY EASTWARD ACROSS CENTRAL CONUS IN
RESPONSE TO NEXT EASTERN PACIFIC WAVE MOVING ACROSS THE NORTHERN
ROCKIES. HOWEVER...BY LATE WEEKEND/EARLY NEXT WEEK MODEL
DETERMINISTIC/ENSEMBLE SPREADS BECOME MUCH MORE PRONOUNCED WITH
THIS NEXT PACIFIC WAVE. ALSO SIGNIFICANT VARIABILITY EXISTS WITH
EASTERN CANADIAN TROUGH THAT WILL IMPACT TRACK OF UPSTREAM PACIFIC
SYSTEM. GIVEN THESE UNCERTAINTIES...HAVE LOWERED CR ALLBLEND LOW
POPS TO BELOW MENTIONABLE LEVELS AND WILL KEEP MON/TUE DRY AT THIS
TIME.
&&
.AVIATION...
MESOSCALE CONVECTIVE VORTEX ACROSS IL TO MOVE NORTHEAST. ASSOCIATED
LINE OF SHOWERS AND THUNDERSTORMS TO MOVE THROUGH TAF SITES THIS
AFTERNOON. HI RES MODEL DATA WANTS TO DEVELOP ADDITIONAL
PRECIPITATION JUST SOUTH OF VORT TRACK THIS EVENING. THIS REMAINS
UNCERTAIN BUT THIS GUIDANCE HAS DONE WELL THIS MORNING WITH CURRENT
COMPLEX. HAVE LINGERED SHOWERS AT TAF SITES WITH BETTER CHANCES AT
KSBN WHICH IS CLOSER TO UPPER LEVEL SYSTEM. UNCERTAINTY GROWS
OVERNIGHT INTO WEDNESDAY AS UPSTREAM CONVECTIVE COMPLEX LIKELY TO
DEVELOP AND COULD BRUSH THE AREA WEDNESDAY MORNING. TOO MUCH
UNCERTAINTY TO ADD TO TAFS BUT WILL BE WATCHED FOR LATER ISSUANCES.
CONVECTION POSSIBLE AGAIN WED AFTERNOON JUST BEYOND THIS VALID
PERIOD WITH RESIDUAL BOUNDARIES AND UNSTABLE ATMOSPHERE DEVELOPING.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...LASHLEY
LONG TERM...MARSILI
AVIATION...LASHLEY
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
125 PM EDT TUE MAY 1 2012
.AVIATION...
MESOSCALE CONVECTIVE VORTEX ACROSS IL TO MOVE NORTHEAST. ASSOCIATED
LINE OF SHOWERS AND THUNDERSTORMS TO MOVE THROUGH TAF SITES THIS
AFTERNOON. HI RES MODEL DATA WANTS TO DEVELOP ADDITIONAL
PRECIPITATION JUST SOUTH OF VORT TRACK THIS EVENING. THIS REMAINS
UNCERTAIN BUT THIS GUIDANCE HAS DONE WELL THIS MORNING WITH CURRENT
COMPLEX. HAVE LINGERED SHOWERS AT TAF SITES WITH BETTER CHANCES AT
KSBN WHICH IS CLOSER TO UPPER LEVEL SYSTEM. UNCERTAINTY GROWS
OVERNIGHT INTO WEDNESDAY AS UPSTREAM CONVECTIVE COMPLEX LIKELY TO
DEVELOP AND COULD BRUSH THE AREA WEDNESDAY MORNING. TOO MUCH
UNCERTAINTY TO ADD TO TAFS BUT WILL BE WATCHED FOR LATER ISSUANCES.
CONVECTION POSSIBLE AGAIN WED AFTERNOON JUST BEYOND THIS VALID
PERIOD WITH RESIDUAL BOUNDARIES AND UNSTABLE ATMOSPHERE DEVELOPING.
&&
.UPDATE...
MAJOR REVISIONS BEING MADE TO SHORT TERM GRIDS AS STRONG MCV IN
NORTHEAST MO CONTINUES TO DRIVE AREA OF THUNDERSTORMS IN IL. THIS
FEATURE TO CONTINUE A NORTHEAST MOVEMENT AND WITH MODEST ELEVATED
INSTABILITY AND STRONG SHEAR ALONG WITH INCREASING THETA E SHOULD BE
ABLE TO SUSTAIN PRECIPITATION ACROSS THE AREA THIS AFTERNOON.
WORKING ON INCREASING POPS TO CATEGORICAL THROUGH THE AFTERNOON FROM
SOUTHWEST TO NORTHEAST ALONG WITH LOWERING TEMPS GIVEN INCREASED
CLOUD COVER AND RAIN. 12Z NAM12 SHOWING STRONG SHEAR ASSOCIATED WITH
THIS FEATURE AS 0-6KM VALUES IN EXCESS OF 50 KNOTS. INSTABILITY WILL
BE LIMITING FACTOR FOR SEVERE WITH COOLER SURFACE TEMPS NO NOT
EXPECTING WIDESPREAD SEVERE BUT CANNOT RULE OUT ISOLATED STRONG
STORMS IF STRONG UPDRAFTS CAN DEVELOP...ESPECIALLY NEAR WARM FRONT
ACROSS SOUTHERN AREAS. RELIED ON HRRR FOR TIMING POPS AS IT SEEMS TO
HAVE BEST HANDLE ON CONVECTION. UPDATE OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 430 AM EDT TUE MAY 1 2012/
SHORT TERM...
TODAY THROUGH WEDNESDAY NIGHT...SOME LIGHT FOG WAS REMAINING EARLY
THIS MORNING UNDER LOW CLOUD CANOPY. A DISTINCT LOW CLOUD
CLEARING LINE WAS APPROACHING THE AREA FROM THE WEST...BUT AT THE
SAME TIME...HIGH CLOUD DEBRIS FROM UPSTREAM STORMS WAS SPREADING
OVER THE FCST AREA. HAVE REMOVED AREAS OF FOG THIS MORNING.
VISIBILITIES ARE EXPECTED TO REMAIN 2 MILES OR MORE. AN UPPER
LEVEL TROF WILL MOVE ACROSS THE MID MISSISSIPPI VALLEY TODAY AND
MOVE INTO THE WESTERN GREAT LAKES REGION TONIGHT. THERE IS SUPPORT
FOR STRONGER STORMS WITH THIS SYSTEM GIVEN FAVORABLE BULK SHEAR
AND SIZABLE CAPES. BLENDED THE SPECTRAL MODELS FOR A COMMON
SOLUTION THAT SUPPORTS TIMING OF THIS SYSTEM ARRIVING TONIGHT. HAVE
INCREASED STORM CHANCES TO LIKELY. THE FRONT WILL CONTINUE TO LIFE
NORTH...WITH THE BULK OF STORMS STAYING NORTH OF THE FORECAST
AREA WEDNESDAY. LEFT A CHANCE FOR STORMS OVER MAINLY MICHIGAN
COUNTIES GIVEN THE CHANCE FOR A STORM TO DEVELOP ON AN OUTFLOW
BOUNDARY ON WEDNESDAY. OTHERWISE...TEMPERATURES SHOULD BE WARMER
WEDNESDAY WITH HIGHS IN THE MID 80S...SUPPORTED BY THE 00Z MEX
MOS.
LONG TERM...
RECD HEAT XPCD TO START THIS PD ON THU AS CRUX OF BROAD UPR RIDGE
BLDS ACRS THE SERN US IN RESPONSE TO AMPLIFYING UPR TROUGH OVR THE
PACNW. ACTIVE FNTL ZONE XPCD INBTWN ON NRN EDGE OF VRY UNSTABLE WARM
SECTOR. SPATIAL DETAILS STILL UNCERTAIN WRT CONVN THU AFTN/THU NIGHT
HWVR GENERAL LEAD HERE IS TWD CONV AUGMENTATION OF PREDICTED SFC
BNDRY POSITION IN SWRLY FLW ALOFT SWD OF SPECTRAL GUIDANCE
POSITIONING OF TRUE SYNOPTIC BNDRY. THUS HELD VERY CLOSE W/PRIOR POP
GUIDANCE ALTHOUGH DID DROP MENTION OF MUCH OF THU DAYTIME PD AS LL
CAPPING INVERSION SHLD BE WELL DVLPD BY THU AM. OTHERWISE STG MIXING
DURING THE DAY WITHIN ZONE OF SIG HGT RISES ALOFT AND INTENSE LL
THERMAL RIDGE PORTEND 90S PSBL IN SOME SPOTS.
BEYOND THAT...GENERAL AGREEMENT AMG 00Z MED RANGE GUIDANCE POINTS TO
A CONSENSUS OF BROAD NRN STREAM TROUGHING SLOWLY PROGRESSING EWD
THROUGH THE END OF THE PD. THIS ALLUDES TO AN ACTUAL FROPA TWD SAT
W/SUCCESSIVE WAVE ADJUSTMENT ALG COMPOSITED OUTFLW STEMMING FM DAILY
PERIOD CONVN ACRS THE PLAINS/MIDWEST A WILDCARD AS TO ACTUAL
EFFECTIVE SFC BNDRY PLACEMENT. THUS WILL GENERALLY TOE THE LINE
W/DAILY POPS DYS4-5. HWVR DOWNSTREAM BLOCKING RIDGE DEPICTED OVR THE
ATL LENDS CREDENCE TWD OP GFS SOLUTION OF FURTHER AMPLIFICATION ACRS
THE CONUS HEADING THROUGH THE WEEKEND AND COOLING TO NEAR SEASONABLE
TEMPS BEGINNING IN DY6 (SUN).
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...SKIPPER
LONG TERM...T
AVIATION...LASHLEY
UPDATE...LASHLEY
AREA FORECAST DISCUSSION
NWS PADUCAH KY
306 PM CDT TUE MAY 1 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 215 PM CDT TUE MAY 1 2012
WE APPEAR TO BE SOMEWHAT CAPPED THIS AFTERNOON...SOMETHING THAT
BARELY SHOWED UP IN THE RUC MODEL SOUNDING DATA. THE HRRR MODEL
CONTINUED TO UPDATE WITH BANDS OF PCPN ASSOCIATED WITH THE
WEAKENING VORT MAX ACROSS MAINLY SRN IL/SWRN IND/NRN KY...
APPARENTLY NOT TAKING THIS INTO ACCOUNT. HOWEVER...RADAR AT THIS
TIME SHOWED WIDELY SCATTERED SHOWERS BUBBLING UP ACROSS SWRN IND.
WE HAVE WARNINGS AND WATCHES JUST TO OUR EAST. SO...THESE
POTENTIAL STORMS DESERVE WATCHING AS THE 50+KT MID LEVEL JET
EXITS OUR REGION OVER THE NEXT HOUR OR TWO. SUSTAINED 15 KT WINDS
ARE EXPECTED TO SUBSIDE TO AOB 10 KTS OVERNIGHT.
WED WILL BE ANOTHER BREEZY DAY UNDER SWRLY FLOW ALOFT AND A MOIST
SRLY FETCH...BUT NO SIGNIFICANT PCPN IS EXPECTED WITH ANY SFC
FEATURES WELL OUT OF THE AREA. THU SHOULD BE SIMILIAR...EXCEPT
THAT POSSIBLY SOME GULF MOISTURE MAY GET TAPPED IN THE AFTERNOON
MAINLY NEAR THE AR/TN BORDER FOR A SHOWER OR TSTM. ABOVE NORMAL
TEMPS WILL CONTINUE.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 215 PM CDT TUE MAY 1 2012
COMPLICATED SYNOPTIC PATTERN ACROSS THE COUNTRY IS RESULTING A LOW
CONFIDENCE FORECAST THROUGHOUT THE EXTENDED PORTION OF THE FORECAST.
THE PERIOD BEGINS WITH A FAIRLY LOW AMPLITUDE FLOW WITH RIDGING FROM
THE SOUTHERN PLAINS THROUGH MUCH OF THE MISSISSIPPI VALLEY...AND
TROUGHING OVER THE PACIFIC NORTHWEST. MOST RECENT RUNS OF THE
GFS/ECMWF/GEM HAVE TRIED TO DIG A TROUGH INTO THE NORTHEAST OVER THE
WEEKEND...WHICH WOULD DRAG A DECENT SURFACE HIGH SOUTHWARD THROUGH
THE GREAT LAKES AND INTO THE OHIO VALLEY. THIS SURFACE HIGH COULD
POSSIBLY BACK-DOOR OUR REGION...EFFECTIVELY UNDERCUTTING THE UPPER
RIDGE...AND COOLING THINGS DOWN A NOTCH OR TWO. ANOTHER SOLUTION
NOTICED IN THE 00Z ECMWF AND 12Z GFS HAS THE ENERGY FROM THE
NORTHWEST MOVING EAST THROUGH THE TOP OF THE RIDGE...AND EVENTUALLY
BRINGING A COLD FRONT EASTWARD INTO THE REGION OVER THE WEEKEND. IN
EITHER SCENARIO...THE MODELS DIFFER IN TIMING OF POTENTIAL FRONTAL
PASSAGES.
WHAT WE CAN CONFIDENTLY SAY AT THIS POINT IS THAT PRIOR TO ANY
FRONTAL PASSAGE...IT WILL BE HOT...HUMID AND MOST LIKELY DRY. THE
AREA WILL BE ON THE NORTHERN PERIPHERY OF THE RIDGE...SO MCS/S MAY
TRACK EAST AND THEN NORTHEAST AROUND OR POSSIBLY THROUGH A PORTION
OF OUR FORECAST AREA...DEPENDING ON THE ACTUAL STRENGTH OF
THE UPPER HIGH/CAPPING INVERSION. THIS COULD BRING OUTFLOW
BOUNDARIES INTO THE AREA TO MESS UP TEMPERATURES...AND POTENTIALLY
PROVIDE A FOCUS FOR THUNDERSTORM DEVELOPMENT.
IN GENERAL WOULD LIKE TO LEAN TOWARD A DRY AND CONTINUED HOT
FORECAST UNTIL THE MODELS LOCK ONTO A REASONABLE SCENARIO.
HOWEVER...GIVEN ALL THE POTENTIAL FLIES IN THE OINTMENT...WILL
LIKELY KEEP SMALL POPS THROUGOUT THE PERIOD...WITH WARM CONDITIONS
CONTINUING THROUGH THE WEEKEND...FOLLOWED BY A MODEST COOLING TREND
EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 215 PM CDT TUE MAY 1 2012
SFC WINDS SUSTAINED AT AROUND 15 KTS WILL CONTINUE THIS AFTERNOON...
WITH SOME GUSTS TO 25 KTS COMMON. AS A MID/UPPER LEVEL IMPULSE
MOVES SLOWLY EAST ACROSS CENTRAL/NORTHERN ILLINOIS THROUGH THE
AFTERNOON...A BAND/ARC OR TWO OF SHOWERS AND THUNDERSTORMS MAY
DEVELOP TO ITS SOUTH. IT IS NOT CLEAR WHETHER THIS WILL IMPACT ANY
TAF SITES...BUT IT WILL BE MOST LIKELY AT KEVV AND KOWB DURING THE
EARLY TO MID AFTERNOON. FOR TONIGHT...A PERSISTENT SOUTH WINDS
UNDER 10 KTS SHOULD PREVENT FOG FORMATION. OF COURSE...FOG WILL BE
MORE LIKELY IF A SITE RECIEVES SIGNIFICANT RAINFALL LATER THIS
AFTERNOON. GUSTY SOUTHWEST WINDS ARE LIKELY TO DEVELOP AGAIN BY
MID-MORNING WEDNESDAY...BUT IT SHOULD BE DRY THROUGHOUT THE
REGION.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...LAKE WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR ILZ075>078-
080>094.
MO...LAKE WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR MOZ076-086-
087-100-107>112-114.
IN...LAKE WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR INZ081-082-
085>088.
KY...LAKE WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR KYZ001>022.
&&
$$
SHORT TERM...DB
LONG TERM....DRS
AVIATION...DB/DRS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1246 PM CDT TUE MAY 1 2012
.UPDATE...
ISSUED AT 1245 PM CDT TUE MAY 1 2012
DECIDED TO EXPAND THE LAKE WIND ADVISORY OVER THE ENTIRE FORECAST
AREA FOR THE REMAINDER OF THE AFTERNOON. WINDS THROUGHOUT THE
REGION ARE ALREADY SUSTAINED AT 15 MPH OR GREATER...WHICH IS THE
CRITERIA FOR ISSUANCE. WITH GOOD MIXING EXPECTED TO CONTINUE
THROUGHOUT THE AFTERNOON...SEE NO REASON WHY THE WINDS WOULD
WEAKEN SIGNIFICANTLY UNTIL LOSS OF HEATING.
UPDATE ISSUED AT 1110 AM CDT TUE MAY 1 2012
THE ATMOSPHERE OVER THE PAH FCST AREA IS MOIST OVERALL...AND
UNSTABLE. WE HAVE A 50+KT MID LEVEL JET MOVING THROUGH NRN PARTS
OF THE REGION...HOWEVER THE RADARS ARE VIRTUALLY CLEAR OF PCPN AT
THIS LATE MORNING HOUR. THIS MAY BE DUE TO LACK OF POSITIVE VORTICITY
ADVECTION IN THE MID LEVELS...WHICH THE RUC SHOWS MAY OCCUR A FEW
HOURS FROM NOW AS A PARENT MCV ROTATES INTO NRN IL. THOUGH NOT
EXPECTED TO BE NECESSARILY WDSPRD...SHOWER AND TSTM ACTIVITY IS
POSSIBLE WELL INTO THE AFTERNOON...MAINLY OVER SRN IL...ADJACENT
PARTS OF SERN MO...AND SWRN IND. SEVERE WX CANNOT BE RULED OUT
EAST OF THE MS RIVER THIS AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 332 AM CDT TUE MAY 1 2012
SEVERAL ISSUES TO DEAL WITH THIS FORECAST. IN THE VERY SHORT TERM
CONVECTION IS INCREASING ACROSS WEST TENNESSEE AND WEST KENTUCKY.
NOT EXACTLY WHERE THE MESOSCALE MODELS SUGGESTED...BUT SEVERAL DID
SUGGEST IT WAS GOING TO HAPPEN. PATCHY DENSE FOG DEVELOPED OVER
AREAS WHERE IT DID CLEAR OUT EARLIER. AS CLOUDS AND CONVECTION
INCREASE...EXPECT THE FOG TO THIN OUT.
THE LARGE MCS OVER WESTERN MISSOURI SHOULD HEAD THIS WAY BUT AT A
BIT SLOWER PACE THAN EARLIER THOUGHT. THIS IS ALL ASSOCIATED WITH
A DECENT SHORT WAVE THAT SHOULD PASS THROUGH THE AREA THIS
AFTERNOON.
NOT A GREAT SETUP FOR SEVERE WEATHER BUT AN ISOLATED SEVERE STORM
IS POSSIBLE. HAD AN EARLIER REPORT OF MEASURED 40 MPH WINDS IN
CALLOWAY COUNTY. THE COLUMN MOISTENS UP CONSIDERABLY ACCORDING TO
FORECAST SOUNDINGS FROM NAM AND GFS. SO MUCH SO THAT HEAVY RAIN IS
PROBABLY THE BIGGEST THREAT TODAY AS PRECIPITABLE WATER VALUES GO
ABOVE 2 STANDARD DEVIATIONS FROM CLIMO. HAVE PUT THIS WORDING IN
THE GRIDS FOR THE MORNING HOURS WHEN WE EXPECT THE MOST COVERAGE.
FFG VALUES TOO HIGH FOR ANY WATCH CONSIDERATIONS AS THE GROUND IS
VERY DRY IN MOST OF THE AREA.
AFTER THIS SHORT WAVE PASSES THE RIDGE BUILDS OVER THE AREA FOR
WEDNESDAY AND THURSDAY WITH SUMMER WEATHER. SOME RECORDS MAY FALL.
HUMIDITY LEVELS MAY NOT BE BAD ON WEDNESDAY WITH SOME AFTERNOON
MIXING BUT THE MOISTURE INCREASES IN DEPTH ON THURSDAY SO NOT A
LOT OF DRY AIR TO MIX DOWN EVEN WITH GUSTY WINDS.
GOING TEMPERATURES ON WEDNESDAY LOOKED PRETTY GOOD WITH ONLY MINOR
ADJUSTMENTS. HOWEVER...RAISED MAX TEMPS ON THURSDAY AS 850
TEMPERATURES DO NOT CHANGE MUCH AND MAY ACTUALLY RISE A DEGREE OR
TWO IN SOME AREAS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 332 AM CDT TUE MAY 1 2012
AS ALLUDED TO WITH MONDAY MORNINGS FORECAST PACKAGE...THE SOUTHEAST
U.S. RIDGE /ALREADY EVIDENT IN THE THE 00Z TUESDAY MANDATORY UPPER
AIR CHARTS/ WILL SLOWLY RETROGRADE AND BUILD WEST INTO THE LOWER
MISSISSIPPI VALLEY THURSDAY. AT THE BEGINNING OF THIS TIME PERIOD
/THURSDAY NIGHT INTO FRIDAY/ THE DETERMINISTIC GFS/CANADIAN MODEL
SUITES ATTEMPT TO WORK IN A CLOSED LOW OVER NORTHEAST TEXAS /ITS
ORIGINS MOSTLY LIKELY NEAR EL PASO TEXAS EARLY THIS
EVENING/...DISRUPTING BROAD INFLUENCE OF THE UPPER AIR RIDGE AXIS
INTO THE PLAINS FRIDAY INTO SATURDAY AND SLIGHTLY MODIFYING THE
THERMAL PROFILE OVER THE WFO PAH FORECAST AREA...ENOUGH FOR
CONVECTION TO MOVE INTO THE AREA.
ALTHOUGH THERE IS SOME VARIABILITY IN THE PLACEMENT OF THE RIDGE
FROM THE CANADIAN VERSUS TH GFS GUIDANCE OVER THE WEEKEND...BOTH
KEEP THE WFO PAH FORECAST AREA WITHIN THE WARM SECTOR INTO EARLY
NEXT WEEK. THERE IS ALSO SOME INDICATION THAT THE WFO PAH FORECAST
AREA IS ALSO IN A FAVORABLE ZONE FOR ISENTROPIC LIFT...FOCUSED MORE
TOWARD SOUTHERN ILLINOIS...THE PENNYRILE REGION OF WEST KENTUCKY AND
SOUTHWEST INDIANA. THIS AREA WILL LIKELY SEE THE BRUNT OF THE DAILY
CONVECTIVE ACTIVITY OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
ALTHOUGH THE GFS HAS BEEN RECENTLY RUNNING 6-12 HOURS FASTER WITH
THE MOVEMENT OF THE WEATHER SYSTEMS ACROSS THE AREA...IT IS HINTING
A SHIFT TOWARD A MORE NORTHWESTERLY FLOW AROUND THE RIDGE OVER THE
REGION...BRINGING THE BASE OF THE WESTERLIES OVER NORTHEAST SECTIONS
OF THE WFO PAH FORECAST AREA. THIS MAY BE A LITTLE OVERDONE...BUT IT
IS DIFFICULT TO RULE OUT WIDELY SCATTERED TO SCATTERED CONVECTIVE
ACTIVITY OVER MOST OF THE AREA THURSDAY INTO EARLY SATURDAY...THEN
AGAIN MONDAY INTO TUESDAY OF NEXT WEEK. AT THIS TIME...SUNDAY
APPEARS THE LEAST IMPACTED BY CONVECTION AND THE RIDGE IS THE
STRONGEST OVER THE REGION AT THIS TIME PER MODEL GUIDANCE.
TEMPERATURES FOR THE EXTENDED PERIOD OF THE FORECAST WILL REMAIN 10
TO 15 DEGREES ABOVE NORMAL...SIMILAR TO THE CURRENT SHORT TERM TIME
PERIOD.
DUE TO RUN TO RUN DISCREPANCIES...THE ECMWF GUIDANCE WAS NOT UTILIZED
WITH THIS PACKAGE...ESPECIALLY WITH RESPECT TO POP/WEATHER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1110 AM CDT TUE MAY 1 2012
GUSTY SOUTHWEST WINDS WILL DEVELOP THROUGHOUT THE AREA BY 18Z. SOME
GUSTS TO 25 KTS WILL BE POSSIBLE. AS A MID/UPPER LEVEL IMPULSE
MOVES SLOWLY EAST ACROSS CENTRAL/NORTHERN ILLINOIS THROUGH THE
AFTERNOON...A BAND/ARC OR TWO OF SHOWERS AND THUNDERSTORMS ARE
LIKELY TO DEVELOP TO ITS SOUTH. IT IS NOT CLEAR WHETHER THIS WILL
IMPACT ANY TAF SITES...BUT IT WILL BE MOST LIKELY AT KEVV AND KOWB
DURING THE EARLY TO MID AFTERNOON. FOR TONIGHT...A PERSISTENT SOUTH
WINDS UNDER 10 KTS SHOULD PREVENT FOG FORMATION. OF COURSE...FOG
WILL BE MORE LIKELY IF A SITE RECIEVES SIGNIFICANT RAINFALL LATER
THIS AFTERNOON. GUSTY SOUTHWEST WINDS ARE LIKELY TO DEVELOP AGAIN BY
MID-MORNING WEDNESDAY...BUT IT SHOULD BE DRY THROUGHOUT THE REGION.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...LAKE WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR ILZ075>078-
080>094.
MO...LAKE WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR MOZ076-086-
087-100-107>112-114.
IN...LAKE WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR INZ081-082-
085>088.
KY...LAKE WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR KYZ001>022.
&&
$$
UPDATE...DRS/DB
SHORT TERM...PS
LONG TERM....KES
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1110 AM CDT TUE MAY 1 2012
.UPDATE...
ISSUED AT 1110 AM CDT TUE MAY 1 2012
THE ATMOSPHERE OVER THE PAH FCST AREA IS MOIST OVERALL...AND
UNSTABLE. WE HAVE A 50+KT MID LEVEL JET MOVING THROUGH NRN PARTS
OF THE REGION...HOWEVER THE RADARS ARE VIRTUALLY CLEAR OF PCPN AT
THIS LATE MORNING HOUR. THIS MAY BE DUE TO LACK OF POSITIVE VORTICITY
ADVECTION IN THE MID LEVELS...WHICH THE RUC SHOWS MAY OCCUR A FEW
HOURS FROM NOW AS A PARENT MCV ROTATES INTO NRN IL. THOUGH NOT
EXPECTED TO BE NECESSARILY WDSPRD...SHOWER AND TSTM ACTIVITY IS
POSSIBLE WELL INTO THE AFTERNOON...MAINLY OVER SRN IL...ADJACENT
PARTS OF SERN MO...AND SWRN IND. SEVERE WX CANNOT BE RULED OUT
EAST OF THE MS RIVER THIS AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 332 AM CDT TUE MAY 1 2012
SEVERAL ISSUES TO DEAL WITH THIS FORECAST. IN THE VERY SHORT TERM
CONVECTION IS INCREASING ACROSS WEST TENNESSEE AND WEST KENTUCKY.
NOT EXACTLY WHERE THE MESOSCALE MODELS SUGGESTED...BUT SEVERAL DID
SUGGEST IT WAS GOING TO HAPPEN. PATCHY DENSE FOG DEVELOPED OVER
AREAS WHERE IT DID CLEAR OUT EARLIER. AS CLOUDS AND CONVECTION
INCREASE...EXPECT THE FOG TO THIN OUT.
THE LARGE MCS OVER WESTERN MISSOURI SHOULD HEAD THIS WAY BUT AT A
BIT SLOWER PACE THAN EARLIER THOUGHT. THIS IS ALL ASSOCIATED WITH
A DECENT SHORT WAVE THAT SHOULD PASS THROUGH THE AREA THIS
AFTERNOON.
NOT A GREAT SETUP FOR SEVERE WEATHER BUT AN ISOLATED SEVERE STORM
IS POSSIBLE. HAD AN EARLIER REPORT OF MEASURED 40 MPH WINDS IN
CALLOWAY COUNTY. THE COLUMN MOISTENS UP CONSIDERABLY ACCORDING TO
FORECAST SOUNDINGS FROM NAM AND GFS. SO MUCH SO THAT HEAVY RAIN IS
PROBABLY THE BIGGEST THREAT TODAY AS PRECIPITABLE WATER VALUES GO
ABOVE 2 STANDARD DEVIATIONS FROM CLIMO. HAVE PUT THIS WORDING IN
THE GRIDS FOR THE MORNING HOURS WHEN WE EXPECT THE MOST COVERAGE.
FFG VALUES TOO HIGH FOR ANY WATCH CONSIDERATIONS AS THE GROUND IS
VERY DRY IN MOST OF THE AREA.
AFTER THIS SHORT WAVE PASSES THE RIDGE BUILDS OVER THE AREA FOR
WEDNESDAY AND THURSDAY WITH SUMMER WEATHER. SOME RECORDS MAY FALL.
HUMIDITY LEVELS MAY NOT BE BAD ON WEDNESDAY WITH SOME AFTERNOON
MIXING BUT THE MOISTURE INCREASES IN DEPTH ON THURSDAY SO NOT A
LOT OF DRY AIR TO MIX DOWN EVEN WITH GUSTY WINDS.
GOING TEMPERATURES ON WEDNESDAY LOOKED PRETTY GOOD WITH ONLY MINOR
ADJUSTMENTS. HOWEVER...RAISED MAX TEMPS ON THURSDAY AS 850
TEMPERATURES DO NOT CHANGE MUCH AND MAY ACTUALLY RISE A DEGREE OR
TWO IN SOME AREAS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 332 AM CDT TUE MAY 1 2012
AS ALLUDED TO WITH MONDAY MORNINGS FORECAST PACKAGE...THE SOUTHEAST
U.S. RIDGE /ALREADY EVIDENT IN THE THE 00Z TUESDAY MANDATORY UPPER
AIR CHARTS/ WILL SLOWLY RETROGRADE AND BUILD WEST INTO THE LOWER
MISSISSIPPI VALLEY THURSDAY. AT THE BEGINNING OF THIS TIME PERIOD
/THURSDAY NIGHT INTO FRIDAY/ THE DETERMINISTIC GFS/CANADIAN MODEL
SUITES ATTEMPT TO WORK IN A CLOSED LOW OVER NORTHEAST TEXAS /ITS
ORIGINS MOSTLY LIKELY NEAR EL PASO TEXAS EARLY THIS
EVENING/...DISRUPTING BROAD INFLUENCE OF THE UPPER AIR RIDGE AXIS
INTO THE PLAINS FRIDAY INTO SATURDAY AND SLIGHTLY MODIFYING THE
THERMAL PROFILE OVER THE WFO PAH FORECAST AREA...ENOUGH FOR
CONVECTION TO MOVE INTO THE AREA.
ALTHOUGH THERE IS SOME VARIABILITY IN THE PLACEMENT OF THE RIDGE
FROM THE CANADIAN VERSUS TH GFS GUIDANCE OVER THE WEEKEND...BOTH
KEEP THE WFO PAH FORECAST AREA WITHIN THE WARM SECTOR INTO EARLY
NEXT WEEK. THERE IS ALSO SOME INDICATION THAT THE WFO PAH FORECAST
AREA IS ALSO IN A FAVORABLE ZONE FOR ISENTROPIC LIFT...FOCUSED MORE
TOWARD SOUTHERN ILLINOIS...THE PENNYRILE REGION OF WEST KENTUCKY AND
SOUTHWEST INDIANA. THIS AREA WILL LIKELY SEE THE BRUNT OF THE DAILY
CONVECTIVE ACTIVITY OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
ALTHOUGH THE GFS HAS BEEN RECENTLY RUNNING 6-12 HOURS FASTER WITH
THE MOVEMENT OF THE WEATHER SYSTEMS ACROSS THE AREA...IT IS HINTING
A SHIFT TOWARD A MORE NORTHWESTERLY FLOW AROUND THE RIDGE OVER THE
REGION...BRINGING THE BASE OF THE WESTERLIES OVER NORTHEAST SECTIONS
OF THE WFO PAH FORECAST AREA. THIS MAY BE A LITTLE OVERDONE...BUT IT
IS DIFFICULT TO RULE OUT WIDELY SCATTERED TO SCATTERED CONVECTIVE
ACTIVITY OVER MOST OF THE AREA THURSDAY INTO EARLY SATURDAY...THEN
AGAIN MONDAY INTO TUESDAY OF NEXT WEEK. AT THIS TIME...SUNDAY
APPEARS THE LEAST IMPACTED BY CONVECTION AND THE RIDGE IS THE
STRONGEST OVER THE REGION AT THIS TIME PER MODEL GUIDANCE.
TEMPERATURES FOR THE EXTENDED PERIOD OF THE FORECAST WILL REMAIN 10
TO 15 DEGREES ABOVE NORMAL...SIMILAR TO THE CURRENT SHORT TERM TIME
PERIOD.
DUE TO RUN TO RUN DISCREPANCIES...THE ECMWF GUIDANCE WAS NOT UTILIZED
WITH THIS PACKAGE...ESPECIALLY WITH RESPECT TO POP/WEATHER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1110 AM CDT TUE MAY 1 2012
GUSTY SOUTHWEST WINDS WILL DEVELOP THROUGHOUT THE AREA BY 18Z. SOME
GUSTS TO 25 KTS WILL BE POSSIBLE. AS A MID/UPPER LEVEL IMPULSE
MOVES SLOWLY EAST ACROSS CENTRAL/NORTHERN ILLINOIS THROUGH THE
AFTERNOON...A BAND/ARC OR TWO OF SHOWERS AND THUNDERSTORMS ARE
LIKELY TO DEVELOP TO ITS SOUTH. IT IS NOT CLEAR WHETHER THIS WILL
IMPACT ANY TAF SITES...BUT IT WILL BE MOST LIKELY AT KEVV AND KOWB
DURING THE EARLY TO MID AFTERNOON. FOR TONIGHT...A PERSISTENT SOUTH
WINDS UNDER 10 KTS SHOULD PREVENT FOG FORMATION. OF COURSE...FOG
WILL BE MORE LIKELY IF A SITE RECIEVES SIGNIFICANT RAINFALL LATER
THIS AFTERNOON. GUSTY SOUTHWEST WINDS ARE LIKELY TO DEVELOP AGAIN BY
MID-MORNING WEDNESDAY...BUT IT SHOULD BE DRY THROUGHOUT THE REGION.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...LAKE WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR ILZ075-076-
080>082-084>086-088-089-092-093.
MO...LAKE WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR MOZ076-086-
087-108>112-114.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DB
SHORT TERM...PS
LONG TERM....KES
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
131 PM EDT TUE MAY 1 2012
.SYNOPSIS...
ISSUED AT 345 AM EDT TUE MAY 1 2012
A MAINLY QUIET DAY IS EXPECTED FOR TODAY AS A FRONTAL SYSTEM
REMAINS SOUTH OF THE AREA THROUGH THE DAY. THE CHANCE OF SHOWERS
AND STORMS WILL GRADUALLY INCREASE LATE THIS AFTERNOON THROUGH
WEDNESDAY MORNING AS THE FRONT LIFTS NORTH ACROSS THE STATE. WE
WILL THEN SEE CHANCES FOR SHOWERS AND STORMS THROUGH THE WEEKEND
WITH WARM WEATHER HOLDING IN THROUGH THEN.
&&
.UPDATE...
ISSUED AT 1240 PM EDT TUE MAY 1 2012
INCREASED POPS AND LOWERED TEMPS THIS AFTERNOON FOR SOUTHERN
LOCATIONS. RADAR SHOWS THE BAND OF SHOWERS APPROACHING FROM THE
SOUTH AND THEY SHOULD MOVE INTO THE I94 CORRIDOR BY 21Z. THE MOST
RECENT TREND HAS THEM WEAKENING.
UPDATE ISSUED AT 800 AM EDT TUE MAY 1 2012
I HAVE NOTED THE MCV OVER MO HEADING NORTHEAST TOWARD SOUTHERN
LOWER MICHIGAN BY LATE AFTERNOON. THE HRRR AND RUC SEEM TO LIKE
THE FEATURE AND THE RUC SHOWS A 40 KNOT LLJ INTO CNTL IL BY 18Z.
THE HRRR KEEPS THE ACTUAL THUNDERSTORMS NEAR AND SOUTH OF I-80 BUT
BRINGS RAIN SOUTH OF I-96 BY 20Z. SO AFTER TALKING WITH IWX SHORT
TERM... WE DECIDED TO GO AHEAD AND BRING THE CONVECTION IN MID TO
LATE AFTERNOON. THE UPDATED GRIDS AND ZONES HAVE BEEN ISSUED
ALREADY.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 345 AM EDT TUE MAY 1 2012
THE MAIN FORECAST CHALLENGE THROUGH THE SHORT TERM WILL BE
DETERMINING CONVECTIVE TRENDS THROUGH THE PERIOD AS A FRONTAL
SYSTEM WILL RESIDE ACROSS THE REGION THROUGH THE PERIOD.
THE QUIETEST PERIOD OF THE SHORT TERM IS EXPECTED TO BE THE DAY
TODAY. THE AREA CONTINUES TO BE SHROUDED IN CLOUD COVER EARLY THIS
MORNING. THE CLEARING LINE...NOW ACROSS ERN WISCONSIN...IS
EXPECTED TO MOVE ACROSS THE AREA THIS MORNING. FAR WESTERN AREAS
COULD SEE SOME FOG DEVELOP IF IT CLEARS OUT EARLY ENOUGH BEFORE
DAYBREAK. WE DO NOT EXPECT THERE WILL BE ENOUGH TIME FOR THE FOG TO
BECOME A PROBLEM.
WE SHOULD SEE A DECENT AMOUNT OF SUNSHINE DURING THE DAY TODAY
WITH SOME MID/HIGH CLOUDS FLOATING ACROSS THE AREA. LATE IN THE
DAY ACROSS THE FAR SOUTH...WE WILL BEGIN TO SEE AN INFLUX OF
MOISTURE AS WAA/ISENTROPIC ASCENT INCREASES WITH THE APPROACH OF
THE STALLED OUT FRONT TO OUR SOUTH. WE MAY SEE JUST ENOUGH MOISTURE
ADVECTION FOR A LOW CHC OF A FEW SHOWERS/STORM LATE ACROSS THE SRN
COUNTIES. H850 TEMPS OF AROUND 10 TO 12C SUPPORT HIGHS IN THE 70S.
THE WARM AND MOIST ADVECTION WILL CONTINUE INTO TONIGHT AS THE LOW
LEVEL JET NOSES IN FROM THE SW LATER TONIGHT. WE EXPECT TO SEE THE
BEST THREAT OF SHOWERS/STORMS ACROSS THE SRN HALF OF THE CWFA
DURING THE LAST HALF OF THE NIGHT TONIGHT. MOISTURE TRANSPORT IS
FCST TO SPREAD ACROSS THE ENTIRE AREA...SO A CHC/SCT
SHOWERS/STORMS WILL BE EXPECTED EVEN NORTH. THIN CAPE PROFILES AND
THE ELEVATED NATURE OF THE STORMS SHOULD LIMIT SEVERE
POTENTIAL...EVEN WITH BULK SHEAR VALUES AROUND 25-35 KNOTS.
CONVECTION WILL STILL LIKELY BE AROUND THE AREA FIRST THING WED
MORNING. MODELS INDICATE THAT THE SFC WAVE MOVING NW OF THE AREA
SHOULD DRAW THE FRONT TO THE NORTH OF THE CWFA IN THE AFTERNOON.
THE SURGE OF MOISTURE TRANSPORT WILL PULL OUT IN THE AFTERNOON...
AND WE COULD SEE CLEARING TAKE PLACE AS WE GET INTO THE WARM
SECTOR. IF THIS WAS TO OCCUR...WE WOULD EASILY SEE TEMPS HIT 80 AT
INLAND LOCATIONS. CONVECTION CHCS LOOK TO DECREASE AS THE
ATMOSPHERE LOOKS TO BECOME CAPPED. STILL NOT IMPOSSIBLE TO SEE
ANOTHER WAVE MOVE THROUGH HOWEVER...SO WE KEPT A CHC IN DURING THE
AFTERNOON.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 345 AM EDT TUE MAY 1 2012
CONVECTION IS EXPECTED TO SOME EXTENT EACH DAY. THE GREATEST CHANCE
FOR STRONG STORMS IS WEDNESDAY NIGHT AND THURSDAY NIGHT (WHEN
THE LOW LEVEL IS CLOSEST). TEMPERATURES WILL UNSEASONABLY WARM INTO
FRIDAY THEN COOL OFF SOME INTO THE WEEKEND.
OVER THE PAST FEW DAYS WE HAVE BEEN WATCHING HOW THE POLAR JET
MIGRATES NORTHWARD INTO SOUTHERN CANADA THE SECOND HALF OF THIS
WEEK INTO THE WEEKEND. THAT IS THE RESULT OF THE WESTERN TROUGH
DEEPENING AND BUILDING AN UPSTREAM RIDGE OVER THE CENTRAL CONUS.
THE FARTHER NORTH THE JET GETS THE LESS LIKELY IS STRONG CONVECTION
HERE. THAT IS MOSTLY DUE TO THE LACK OF DEEP LAYERED SHEAR. THE
MODELS ARE ALL IN GOOD AGREEMENT THAT FEATURE OF THE FORECAST.
THE REAL FORECAST PROBLEMS COME IN OVER THE WEEKEND AS THE ECMWF
CONTINUES TO KEEP THE UPPER LOW OVER NE CANADA OVER NE CANADA WHILE
THE GFS CONTINUES TO DIG THE FEATURE SOUTH SOUTHEAST TOWARD NEW
ENGLAND BY LATE IN THE WEEKEND. THE END RESULT IS THE ECMWF KEEPS
THE FRONT NEAR SOUTHWEST MICHIGAN THROUGH THE WEEKEND WHICH IN TURN
KEEPS THE THREAT FOR CONVECTION EACH DAY. MEANWHILE WITH THE GFS
BRINGING THE UPPER LOW SOUTH SOUTHEAST IT ALSO BRINGS CANADIAN POLAR
AIR SOUTH INTO THE GREAT LAKES SATURDAY NIGHT INTO SUNDAY. THAT OF
COURSE DRIES OUT THE AIR AND ENDS THE RISK FOR CONVECTION BY
SATURDAY NIGHT. I AM SIDING WITH THE ECMWF HERE.
THE LOW LEVEL JET MOVES THROUGH SOUTHWEST MICHIGAN THURSDAY NIGHT
INTO FRIDAY MORNING. THAT IS WHEN THERE SHOULD BE THE GREATEST
THREAT FOR THUNDERSTORMS FOR SOUTHWEST LOWER MICHIGAN. HOWEVER WITH
THE UPPER JET WELL NORTH IN CANADA...THESE STORMS SHOULD NOT BE ALL
THAT STRONG. OVER THE WEEKEND I AM LEANING TOWARD THE ECMWF INTO THE
WEEKEND BUT DUE TO INCREASING UNCERTAINLY WE HAVE LOWER POPS
SATURDAY AND SUNDAY.
WITH THE POLAR JET SO FAR NORTH AND THE SURFACE FRONT NORTH OF
SOUTHWEST LOWER MICHIGAN THURSDAY... IT SHOULD BE VERY WARM. LOW
LEVEL THICKNESS TOOLS SUPPORT HIGHS IN THE MID 80S... EVEN WITH A
FEW CLOUDS AND SHOWERS AROUND. THE FRONT SAGS SOUTH FRIDAY AND
STALLS SATURDAY... DUE TO CLOSENESS OF THE FRONT HIGHS WILL ONLY BE
IN THE 70S FRIDAY AND SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 131 PM EDT TUE MAY 1 2012
RAIN SHOWERS WERE APPROACHING THE AREA AS OF 1730Z FROM THE SW.
THESE SHOULD ONLY IMPACT THE I-94 TAF SITES AFTER 20-21Z. HOWEVER
ANY THUNDER IS EXPECTED TO REMAIN SOUTH OF THE MI/IN BORDER. THESE
SHOWERS MAY BRING THE I-94 TAFS DOWN INTO THE MVFR RANGE LATER
THIS EVENING...WHILE THE I-96 SITES REMAIN VFR. EXPECT THAT MUCH
OF THE MVFR WILL LIFT OUT OF THE AREA BY EARLY TO MID WED MORNING.
THERE SHOULD BE A MORE WIDESPREAD AREA OF SHOWERS AND SCATTERED
THUNDERSTORMS THAT MOVES INTO THE AREA AFTER 09Z WED. THIS COULD
LINGER THROUGH 18Z.
&&
.MARINE...
ISSUED AT 1240 PM EDT TUE MAY 1 2012
SOUTH WINDS WILL REMAIN UNDER 20 KNOTS SO NOT MUCH IMPACT TO
MARINERS EXPECTED FOR THE NEXT FEW DAYS. THERE WILL BE SOME
THUNDERSTORMS THAT WILL POSE A RISK TO MARINERS
&&
.HYDROLOGY...
ISSUED AT 345 AM EDT TUE MAY 1 2012
A FAIRLY MOISTURE RICH AIR MASS WILL MOVE IN BEGINNING LATE TODAY
AND ESPECIALLY TONIGHT. PRECIPITABLE WATER IS EXPECTED TO INCREASE
TO 1.25 TO 1.50 INCHES TONIGHT. THIS AIR MASS SHOULD REMAIN IN
PLACE THROUGH THE REMAINDER OF THE WEEK AND INTO THE WEEKEND. THIS
WILL ALLOW FOR LOCALLY HEAVY RAINFALL TO OCCUR WITH ANY
SHOWERS/STORMS. WE SHOULD NOT HAVE ANY ISSUES WITH THIS. THE ONLY
ISSUE THAT COULD ARISE WOULD BE IF WAVES OF SHOWERS/STORMS START
ROLLING OVER THE SAME AREAS DURING THE NEXT FEW DAYS. THE TRACK OF
ANY SHOWERS/STORMS IS QUITE UNCERTAIN AT THIS TIME.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...MJS
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...WDM
AVIATION...JK
HYDROLOGY...NJJ
MARINE...MJS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1243 PM EDT TUE MAY 1 2012
.SYNOPSIS...
ISSUED AT 345 AM EDT TUE MAY 1 2012
A MAINLY QUIET DAY IS EXPECTED FOR TODAY AS A FRONTAL SYSTEM
REMAINS SOUTH OF THE AREA THROUGH THE DAY. THE CHANCE OF SHOWERS
AND STORMS WILL GRADUALLY INCREASE LATE THIS AFTERNOON THROUGH
WEDNESDAY MORNING AS THE FRONT LIFTS NORTH ACROSS THE STATE. WE
WILL THEN SEE CHANCES FOR SHOWERS AND STORMS THROUGH THE WEEKEND
WITH WARM WEATHER HOLDING IN THROUGH THEN.
&&
.UPDATE...
ISSUED AT 1240 PM EDT TUE MAY 1 2012
INCREASED POPS AND LOWERED TEMPS THIS AFTERNOON FOR SOUTHERN
LOCATIONS. RADAR SHOWS THE BAND OF SHOWERS APPROACHING FROM THE
SOUTH AND THEY SHOULD MOVE INTO THE I94 CORRIDOR BY 21Z. THE MOST
RECENT TREND HAS THEM WEAKENING.
UPDATE ISSUED AT 800 AM EDT TUE MAY 1 2012
I HAVE NOTED THE MCV OVER MO HEADING NORTHEAST TOWARD SOUTHERN
LOWER MICHIGAN BY LATE AFTERNOON. THE HRRR AND RUC SEEM TO LIKE
THE FEATURE AND THE RUC SHOWS A 40 KNOT LLJ INTO CNTL IL BY 18Z.
THE HRRR KEEPS THE ACTUAL THUNDERSTORMS NEAR AND SOUTH OF I-80 BUT
BRINGS RAIN SOUTH OF I-96 BY 20Z. SO AFTER TALKING WITH IWX SHORT
TERM... WE DECIDED TO GO AHEAD AND BRING THE CONVECTION IN MID TO
LATE AFTERNOON. THE UPDATED GRIDS AND ZONES HAVE BEEN ISSUED
ALREADY.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 345 AM EDT TUE MAY 1 2012
THE MAIN FORECAST CHALLENGE THROUGH THE SHORT TERM WILL BE
DETERMINING CONVECTIVE TRENDS THROUGH THE PERIOD AS A FRONTAL
SYSTEM WILL RESIDE ACROSS THE REGION THROUGH THE PERIOD.
THE QUIETEST PERIOD OF THE SHORT TERM IS EXPECTED TO BE THE DAY
TODAY. THE AREA CONTINUES TO BE SHROUDED IN CLOUD COVER EARLY THIS
MORNING. THE CLEARING LINE...NOW ACROSS ERN WISCONSIN...IS
EXPECTED TO MOVE ACROSS THE AREA THIS MORNING. FAR WESTERN AREAS
COULD SEE SOME FOG DEVELOP IF IT CLEARS OUT EARLY ENOUGH BEFORE
DAYBREAK. WE DO NOT EXPECT THERE WILL BE ENOUGH TIME FOR THE FOG TO
BECOME A PROBLEM.
WE SHOULD SEE A DECENT AMOUNT OF SUNSHINE DURING THE DAY TODAY
WITH SOME MID/HIGH CLOUDS FLOATING ACROSS THE AREA. LATE IN THE
DAY ACROSS THE FAR SOUTH...WE WILL BEGIN TO SEE AN INFLUX OF
MOISTURE AS WAA/ISENTROPIC ASCENT INCREASES WITH THE APPROACH OF
THE STALLED OUT FRONT TO OUR SOUTH. WE MAY SEE JUST ENOUGH MOISTURE
ADVECTION FOR A LOW CHC OF A FEW SHOWERS/STORM LATE ACROSS THE SRN
COUNTIES. H850 TEMPS OF AROUND 10 TO 12C SUPPORT HIGHS IN THE 70S.
THE WARM AND MOIST ADVECTION WILL CONTINUE INTO TONIGHT AS THE LOW
LEVEL JET NOSES IN FROM THE SW LATER TONIGHT. WE EXPECT TO SEE THE
BEST THREAT OF SHOWERS/STORMS ACROSS THE SRN HALF OF THE CWFA
DURING THE LAST HALF OF THE NIGHT TONIGHT. MOISTURE TRANSPORT IS
FCST TO SPREAD ACROSS THE ENTIRE AREA...SO A CHC/SCT
SHOWERS/STORMS WILL BE EXPECTED EVEN NORTH. THIN CAPE PROFILES AND
THE ELEVATED NATURE OF THE STORMS SHOULD LIMIT SEVERE
POTENTIAL...EVEN WITH BULK SHEAR VALUES AROUND 25-35 KNOTS.
CONVECTION WILL STILL LIKELY BE AROUND THE AREA FIRST THING WED
MORNING. MODELS INDICATE THAT THE SFC WAVE MOVING NW OF THE AREA
SHOULD DRAW THE FRONT TO THE NORTH OF THE CWFA IN THE AFTERNOON.
THE SURGE OF MOISTURE TRANSPORT WILL PULL OUT IN THE AFTERNOON...
AND WE COULD SEE CLEARING TAKE PLACE AS WE GET INTO THE WARM
SECTOR. IF THIS WAS TO OCCUR...WE WOULD EASILY SEE TEMPS HIT 80 AT
INLAND LOCATIONS. CONVECTION CHCS LOOK TO DECREASE AS THE
ATMOSPHERE LOOKS TO BECOME CAPPED. STILL NOT IMPOSSIBLE TO SEE
ANOTHER WAVE MOVE THROUGH HOWEVER...SO WE KEPT A CHC IN DURING THE
AFTERNOON.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 345 AM EDT TUE MAY 1 2012
CONVECTION IS EXPECTED TO SOME EXTENT EACH DAY. THE GREATEST CHANCE
FOR STRONG STORMS IS WEDNESDAY NIGHT AND THURSDAY NIGHT (WHEN
THE LOW LEVEL IS CLOSEST). TEMPERATURES WILL UNSEASONABLY WARM INTO
FRIDAY THEN COOL OFF SOME INTO THE WEEKEND.
OVER THE PAST FEW DAYS WE HAVE BEEN WATCHING HOW THE POLAR JET
MIGRATES NORTHWARD INTO SOUTHERN CANADA THE SECOND HALF OF THIS
WEEK INTO THE WEEKEND. THAT IS THE RESULT OF THE WESTERN TROUGH
DEEPENING AND BUILDING AN UPSTREAM RIDGE OVER THE CENTRAL CONUS.
THE FARTHER NORTH THE JET GETS THE LESS LIKELY IS STRONG CONVECTION
HERE. THAT IS MOSTLY DUE TO THE LACK OF DEEP LAYERED SHEAR. THE
MODELS ARE ALL IN GOOD AGREEMENT THAT FEATURE OF THE FORECAST.
THE REAL FORECAST PROBLEMS COME IN OVER THE WEEKEND AS THE ECMWF
CONTINUES TO KEEP THE UPPER LOW OVER NE CANADA OVER NE CANADA WHILE
THE GFS CONTINUES TO DIG THE FEATURE SOUTH SOUTHEAST TOWARD NEW
ENGLAND BY LATE IN THE WEEKEND. THE END RESULT IS THE ECMWF KEEPS
THE FRONT NEAR SOUTHWEST MICHIGAN THROUGH THE WEEKEND WHICH IN TURN
KEEPS THE THREAT FOR CONVECTION EACH DAY. MEANWHILE WITH THE GFS
BRINGING THE UPPER LOW SOUTH SOUTHEAST IT ALSO BRINGS CANADIAN POLAR
AIR SOUTH INTO THE GREAT LAKES SATURDAY NIGHT INTO SUNDAY. THAT OF
COURSE DRIES OUT THE AIR AND ENDS THE RISK FOR CONVECTION BY
SATURDAY NIGHT. I AM SIDING WITH THE ECMWF HERE.
THE LOW LEVEL JET MOVES THROUGH SOUTHWEST MICHIGAN THURSDAY NIGHT
INTO FRIDAY MORNING. THAT IS WHEN THERE SHOULD BE THE GREATEST
THREAT FOR THUNDERSTORMS FOR SOUTHWEST LOWER MICHIGAN. HOWEVER WITH
THE UPPER JET WELL NORTH IN CANADA...THESE STORMS SHOULD NOT BE ALL
THAT STRONG. OVER THE WEEKEND I AM LEANING TOWARD THE ECMWF INTO THE
WEEKEND BUT DUE TO INCREASING UNCERTAINLY WE HAVE LOWER POPS
SATURDAY AND SUNDAY.
WITH THE POLAR JET SO FAR NORTH AND THE SURFACE FRONT NORTH OF
SOUTHWEST LOWER MICHIGAN THURSDAY... IT SHOULD BE VERY WARM. LOW
LEVEL THICKNESS TOOLS SUPPORT HIGHS IN THE MID 80S... EVEN WITH A
FEW CLOUDS AND SHOWERS AROUND. THE FRONT SAGS SOUTH FRIDAY AND
STALLS SATURDAY... DUE TO CLOSENESS OF THE FRONT HIGHS WILL ONLY BE
IN THE 70S FRIDAY AND SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 0800 AM EDT TUE MAY 1 2012
USING OUR TIMINIG TOOL AND THE NAM12 950 TO 900 MB RH IT SEEMS THE
LOW CLOUDS WILL BREAK UP IN THE 15Z TIME FRAME. HOWEVER NO SOONER
DOES THAT HAPPEN THEN THE MCV TO OUR SW COMES INTO OUR CWA
SOUTHERN CWA BY 21Z OR SO. THE THUNDER SHOULD STAY SOUTH THIS
AFTERNOON.
SHOULD BE MVFR CIGS/VSBY OVERNIGHT AS THE WARM FRONT PUSHES NORTH
WITH HIGHER SURFACE DEW POINT AIR. ALSO THE LOW LEVEL JET NOSES IN
AFTER 06Z SO THAT COULD SET OFF ANOTHER ROUND OF CONVECTION. DUE
TO UNCERTAINTY I DID NOT PUT SHOWERS IN TAFS.
&&
.MARINE...
ISSUED AT 1240 PM EDT TUE MAY 1 2012
SOUTH WINDS WILL REMAIN UNDER 20 KNOTS SO NOT MUCH IMPACT TO
MARINERS EXPECTED FOR THE NEXT FEW DAYS. THERE WILL BE SOME
THUNDERSTORMS THAT WILL POSE A RISK TO MARINERS
&&
.HYDROLOGY...
ISSUED AT 345 AM EDT TUE MAY 1 2012
A FAIRLY MOISTURE RICH AIR MASS WILL MOVE IN BEGINNING LATE TODAY
AND ESPECIALLY TONIGHT. PRECIPITABLE WATER IS EXPECTED TO INCREASE
TO 1.25 TO 1.50 INCHES TONIGHT. THIS AIR MASS SHOULD REMAIN IN
PLACE THROUGH THE REMAINDER OF THE WEEK AND INTO THE WEEKEND. THIS
WILL ALLOW FOR LOCALLY HEAVY RAINFALL TO OCCUR WITH ANY
SHOWERS/STORMS. WE SHOULD NOT HAVE ANY ISSUES WITH THIS. THE ONLY
ISSUE THAT COULD ARISE WOULD BE IF WAVES OF SHOWERS/STORMS START
ROLLING OVER THE SAME AREAS DURING THE NEXT FEW DAYS. THE TRACK OF
ANY SHOWERS/STORMS IS QUITE UNCERTAIN AT THIS TIME.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...MJS
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...NJJ
MARINE...MJS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
341 PM CDT TUE MAY 1 2012
.SHORT TERM...TONIGHT THROUGH FRIDAY
GOING FCST IS IN GOOD SHAPE...ONLY MINOR TWEAKS MADE. MAIN CONCERN
THEN CONTINUES TO BE PINNING DOWN AREAL COVERAGE OF SVR STORM
ACTIVITY THIS EVENING. AS OF NOW IT APPEARS THAT THE UPPER MIDWEST
WILL BE PRIME FOR SVR STORMS IN ASSOCIATED WITH LIFTING WARM FRONT...
WITH ANOTHER AREA OF RISK ASSOCIATED WITH COOL FRONT CURRENTLY
DROPPING THRU THE DAKOTAS. HRRR AND RAP SOLUTIONS HAVE BEEN RATHER
CONSISTENT TODAY SUGGESTING LINE OF CONVECTION MOVING INTO THE NRN
CWA BY EARLY EVENING. ESRH AROUND 360 M2/S2 AND MUCAPES 2000 J/KG OR
SO SHOULD BE ENOUGH TO POP SOME SVR MAINLY OVER NORTHEAST NEB.
AMPLIFYING TROF DIG OVER THE WRN CONUS WILL REPLACE THE NEAR-ZONAL
FLOW WITH LOW AMPLITUDE UPPER RIDGE GRADUALLY BUILDING OVER THE
PLAINS. THIS WILL ACT TO HINDER BNDRY PROGRESSION ANY FARTHER SOUTH
AND KEEP IT INVOF THE CWA. ON WEDNESDAY...MUCAPES INCREASE TO 4500
J/KG BY AFTERNOON BUT DEEP LAYER SHEAR IS MORE FOCUSED NORTH. THUS
NORTHEAST NEB MAY BE UNDER THE GUN AGAIN LATE WEDNESDAY
AFTN/EVENING. THURSDAY THROUGH FRIDAY MODELS PROG SEVERAL IMPULSES
EJECTING OUT OF THE SOUTHWESTERN STATES MAY HELP DESTABILIZE ENOUGH
TO POP OFF ADDITIONAL CONVECTION.
DEE
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
FAIRLY ACTIVE WEATHER PATTERN SHOULD CONTINUE INTO EARLY NEXT WEEK
AS UPPER TROUGH REMAIN TO OUR WEST...EJECTING WAVES OF ENERGY INTO
THE PLAINS.
WARM ADVECTION FRIDAY NIGHT MAY SPARK THUNDERSTORMS OVER THE
NORTHERN CWA...NORTH OF A EAST-WEST WARM FRONT BISECTING OUR AREA.
THOSE SHOULD MOVE ON OFF TO THE NORTHEAST FAIRLY QUICKLY SATURDAY
MORNING...LEAVING OUR CWA IN A VERY UNSTABLE AIRMASS BY SATURDAY
AFTERNOON. CAPPING UNDER WEAK MID LEVEL RIDGE MAY PRECLUDE
DEVELOPMENT MUCH OF THE DAY...MOST LIKELY WAITING FOR LOWERING
HEIGHTS AS RIDGE SLIDES EAST SATURDAY EVENING. THUNDERSTORMS ARE
GOOD BET THEN...ESPECIALLY IN THE NORTH WHERE A COLD FRONT WILL BE
APPROACHING OVERNIGHT.
THAT FRONT WILL DRIFT ACROSS THE AREA SUNDAY...MAINTAINING A FAIRLY
HIGH CHANCE FOR CONTINUING RAIN AND THUNDER. COOLER AIR WILL
FOLLOW...BUT THE CHANCE FOR RAIN OR SHOWERS WILL STILL EXIST AS
MOIST SOUTHWEST FLOW ALOFT RIDES OVER COOL SURFACE LAYER. THIS
PATTERN PERSISTS THROUGH TUESDAY.
TEMPERATURES LOOK WARM SATURDAY WITH SOUTHERLY FLOW AND MORE
HUMIDITY. HAVE HIGHS IN THE 80S THEN. RAIN AND COLD FRONTAL PASSAGE
WILL COOL HIGHS INTO THE 70S SUNDAY...THEN ONLY 60S FOR MONDAY AND
TUESDAY INFLUENCED BY NORTH TO EAST LOW LEVEL WIND COMPONENT.
DERGAN
&&
.AVIATION...
18Z TAFS FOR KOMA...KLNK...AND KOFK.
THUNDERSTORM DEVELOPMENT IS THE PRIMARY CONCERN AT ALL TAF SITES.
BELIEVE THAT A COMPLEX OF STORMS SHOULD DEVELOP ALONG A COLD FRONT
NORTHWEST OF KOFK LATE THIS AFTERNOON...THEN AFFECT THAT SITE FROM
ABOUT 00-04Z...THEN ROLL/DEVELOP EAST SOUTHEAST AND AFFECT KLNK/KOMA
FROM ABOUT 04-09Z. UNTIL THEN...VFR CONDITIONS...WITH SOUTH
SOUTHWEST WINDS AT 16 TO 18 SUSTAINED...WITH GUSTS UP TO 26 TO
28KTS. AFTER THE STORMS MOVE THROUGH...SOME MVFR FOG OR HAZE COULD
DEVELOP FROM ABOUT 09Z-15Z. COULD ALSO SOME SEE SOME LOWER MVFR
STRATO CLOUDS DEVELOPING OVERNIGHT AS WELL.
DEWALD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1257 PM CDT TUE MAY 1 2012
.AVIATION...18Z KGRI TAF. CONFIDENCE IS RATHER LOW CONCERNING SKY
COVER FOR THIS FORECAST. A PATCH OF STRATUS TO THE WEST OF THE
TERMINAL HAS REMAINED WEST FOR THE MOST PART...BUT SEEMS TO BE
RATHER STUBBORN AND SHOWING SIGNS OF EASTWARD MOVEMENT POTENTIAL.
MODELS ARE NOT HANDLING THIS MESOSCALE FEATURE VERY WELL. THE BEST
GUESS IS THAT THESE CEILINGS NEAR 2500 FT WILL REMAIN TO THE WEST
OF THE TERMINAL. THUNDERSTORM POTENTIAL HAS DECREASED TO THE POINT
THAT THESE HAVE BEEN PULLED OUT OF THE FORECAST...WITH ANY
DEVELOPMENT BEING TO THE NORTH AND EAST. MODELS INDICATE THAT
THERE COULD BE A BIT OF A VISIBILITY RESTRICTION LATE TONIGHT INTO
WEDNESDAY MORNING...BUT NOT AS PERVASIVE AS THE PAST COUPLE OF
MORNINGS.
&&
.UPDATE...UPDATED THE FORECAST FOR THIS AFTERNOON TO ACCOUNT FOR
STUBBORN STRATUS IN THE WESTERN CWA AND THICKENING CIRRUS LATER
THIS AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 1036 AM CDT TUE MAY 1 2012/
UPDATE...JUST COMPLETED THE FIRST UPDATE OF THE DAY...ADDRESSING
TWO MAIN TOPICS. FIRST OFF...PULLED ALL MENTION OF FOG...AS
VISIBILITIES HAVE GREATLY IMPROVED...AND MOSTLY CLEAR SKIES NOW
DOMINATE MOST OF THE CWA...EXCEPT FOR STUBBORN LOW STRATUS
HANGING FIRM MAINLY WEST OF AN ORD-BEAVER CITY LINE WHICH SHOULD
ALSO SCATTER OUT EVENTUALLY. SECOND AND OVERALL MORE IMPORTANT
FOCUS WAS THUNDERSTORM CHANCES THROUGH LATE THIS AFTERNOON. AFTER
PERUSING A NUMBER OF SHORT TERM DETERMINISTIC AND HIGH RES
MODELS...ALONG WITH SREF PROBABILITIES...FEEL THAT THE CHANCES OF
SEEING MUCH STORM DEVELOPMENT PRIOR TO 22Z-00Z ARE QUITE LIMITED.
ONE REASON FOR THIS INVOLVES THE FACT THAT THE MAIN SURFACE
TROUGH/COLD FRONT AND RESULTANT LOW LEVEL CONVERGENCE ZONE WILL
STILL REMAIN NORTHWEST OF THE CWA THROUGH THIS TIME. IN
ADDITION...EVEN THE 12Z NAM...WHICH ADVERTISES CONSIDERABLE MLCAPE
VALUES OF AROUND 3000 J/KG ACROSS MUCH OF THE CWA LATER THIS
AFTERNOON...KEEPS AT LEAST A WEAK CAP IN PLACE...WHICH SHOULD BE
TOUGH TO BREAK GIVEN THAT FORCING FROM THE PRIMARY LOW AMPLITUDE
SHORTWAVE OF INTEREST WILL NOT REALLY BE ARRIVING UNTIL THIS
EVENING. AS A RESULT...CUT BACK A BIT ON AFTERNOON POPS...AND
ALTHOUGH THEY WERE NOT HIGH IN THE FIRST PLACE...NOW HAVE ONLY A
TOKEN 20 PERCENT CHANCE LATE THIS AFTERNOON ACROSS ONLY THE
NORTHWEST AND FAR EASTERN COUNTIES...WITH MOST OF THE
CENTRAL/SOUTHWEST FREE OF STORM CHANCES UNTIL AFTER 00Z INCLUDING
THE TRI CITIES. THE EASTERN POPS ARE EVEN QUESTIONABLE...BUT BOTH
THE RUC AND SREF SOMEHOW SUGGEST CONVECTIVE INITIATION IS POSSIBLE
IN THESE AREAS SO KEPT THE SLIGHT CHANCE MENTION. OVERALL...FAVOR
THE 12Z NAM/00Z 4KM WRF-NMM EVOLUTION OF CONVECTIVE CHANCES LATE
THIS AFTERNOON INTO TONIGHT...WITH POTENTIALLY SEVERE STORMS FIRST
FIRING UP TO THE NORTH/WEST OF THE CWA...AND THEN TRYING TO BUILD
SOUTHWARD ALONG THE 850MB FRONT AND INTO A STRENGTHENING LOW LEVEL
JET AXIS THIS EVENING. SEVERE CHANCES ARE STILL THERE...BUT SHOULD
MAINLY FAVOR NEBRASKA ZONES VERSUS NORTHERN KS. MADE NO OTHER
NOTABLE CHANGES AT THIS TIME TO AFTERNOON FORECAST...INCLUDING
HIGH TEMPS.
PREV DISCUSSION... /ISSUED 604 AM CDT TUE MAY 1 2012/
AVIATION...12Z KGRI TAF...LOW LEVEL STRATUS AND BR IS EXPECTED TO
CONTINUE AT KGRI FOR THE NEXT FEW HOURS WITH PREVAILING LIFR CIGS
AND MVFR VSBYS PERSISTING THROUGH ABOUT 01/15Z. AFT
01/15Z...EXPECT A RETURN TO VFR CONDS...WITH INCREASING SOUTHERLY
WINDS...GUSTING TO 20-22KTS THROUGH THE AFTERNOON HOURS. LATE THIS
AFTERNOON...EXPECT AN APPROACHING TROUGH OF LOW PRESSURE TO NEAR
THE TERMINAL...WITH A VCTS OR -TSRA POSSIBLE BETWEEN
02/00Z-02/06Z.
PREV DISCUSSION... /ISSUED 407 AM CDT TUE MAY 1 2012/
SHORT TERM...TODAY THROUGH 12Z FRIDAY. MAIN FORECAST CONCERNS WILL
BE CHANCES FOR THUNDERSTORMS THROUGH MUCH OF THE PERIOD.
SATELLITE AND SURFACE OBSERVATIONS SHOW SOME PATCHY FOG DEVELOPING
EARLY THIS MORNING. VISIBILITIES HAVE DROPPED BELOW A MILE AT A FEW
LOCATIONS...BUT MOSTLY HAVE BEEN ABOVE A MILE. WILL KEEP THE FOG
WITH VISIBILITIES LESS THAN A MILE FOR NOW...BUT WILL WATCH TO SEE
IF WIDESPREAD VISIBILITIES DROP TO A QUARTER MILE.
A SURFACE LOW AND COLD FRONT ON THE HIGH PLAINS WITH A DRY LINE TO
THE SOUTH ALONG THE CENTRAL HIGH PLAINS WILL SLOWLY PUSH TO THE EAST
TODAY. LATE IN THE DAY AN UPPER LEVEL WAVE WILL MOVE ACROSS. CURRENT
DEW POINTS IN THE MID TO UPPER 50S ACROSS THE FORECAST AREA WILL BE
ENOUGH TO ALLOW CAPES THIS AFTERNOON TO RAISE TO OVER 4000 J/KG.
WITH THE FRONT IN THE AREA EXPECT THUNDERSTORMS TO DEVELOP ALONG THE
FRONT LATE THIS AFTERNOON AND CONTINUE INTO THE EVENING HOURS BEFORE
MOVING OFF TO THE EAST. EXPECT THERE MAY BE A LITTLE THAT LINGERS IN
THE EAST LATER TONIGHT.
THE FRONT STALLS ACROSS THE FORECAST AREA LATE TONIGHT INTO
WEDNESDAY NIGHT. ANOTHER UPPER LEVEL WAVE MOVES INTO THE AREA
WEDNESDAY AFTERNOON AND BRINGS ANOTHER CHANCE FOR THUNDERSTORMS TO
THE FORECAST AREA WEDNESDAY AFTERNOON AND NIGHT. THE NAM KEEPS THE
PRECIPITATION FURTHER NORTH THAN THE GFS. BOTH HAVE THE FRONT
FURTHER TO THE SOUTH...BUT THE UPPER WAVE IS FURTHER NORTH. WILL
KEEP CHANCES BEST IN THE NORTH...BUT KEEP SOME CHANCES ACROSS THE
ENTIRE FORECAST AREA. THE UPPER WAVE CONTINUES MOVING THROUGH THE
EASTERN PART OF THE FORECAST AREA THURSDAY SO THERE COULD BE SOME
LINGERING THUNDERSTORMS IN THE EAST ON THURSDAY. FINALLY THURSDAY
NIGHT THE WAVE MOVES TO THE EAST AND EXPECT THAT IT SHOULD BE DRY.
LONG TERM...STARTING 12Z FRIDAY...MODELS IN FAIR AGREEMENT TO START
THE EXTENDED PERIODS WITH LONG WAVE RIDGING ACROSS THE CENTRAL AND
NORTHERN PLAINS...AND A TROUGH OF LOW PRESSURE MOVING ONSHORE ACROSS
THE PACIFIC NORTHWEST. AS A RESULT...EXPECT A DRY END OF THE WORK
WEEK AND START TO THE UPCOMING WEEKEND...WITH ABOVE SEASONAL
TEMPERATURES ACROSS THE ENTIRE AREA.
THIS WARM AND DRY START TO THE EXTENDED WILL BE SHORT LIVED
THOUGH...AS THE AFOREMENTIONED TROUGH TRACKS ACROSS THE INTERMOUNTAIN
WEST AND HELPS TO ERODE THE RIDGE. AT THIS POINT EXTENDED MODELS
BEGIN TO DIVERGE FAIRLY SIGNIFICANTLY...AS THE EC IS MUCH MORE
PROGRESSIVE AND FURTHER NORTH WITH APPROACHING TROUGH...AND GFS
FURTHER AMPLIFIES THE RIDGE...INSTEAD INTENSIFYING A LARGE TROUGH OF
LOW PRESSURE ACROSS THE WESTERN STATES.
WITH SUCH A DISCREPANCY IN LONG TERM MODELS...CONFIDENCE IS NOT
PARTICULARLY HIGH BEYOND SATURDAY...AND STUCK VERY CLOSE TO CONSALL
GUIDANCE FOR POPS IN THE EXTENDED...WITH MODERATE CHANCES FOR SHOWER
AND THUNDERSTORMS BEGINNING SATURDAY EVENING AND PERSISTING THROUGH
MONDAY AFTERNOON...AND SEASONAL TO SLIGHTLY ABOVE SEASONAL
TEMPERATURES PERSISTING. WHILE CONFIDENCE IS NOT EXTREMELY
HIGH...WITH BUILDING INSTABILITY INDICATED BY GFS...AND POTENTIAL OF
PASSING FRONT EVIDENT IN EC...LIKELY WILL SEE SOME SHOWER AND
THUNDERSTORM ACTIVITY EITHER WAY OVER THE LATER HALF OF THE
WEEKEND...SOME OF WHICH WILL HAVE THE POTENTIAL TO BECOME STRONG TO
SEVERE. WITH DIFFERING SOLUTIONS IN MIND...HOWEVER...TIMING IS IN
QUESTION...AND KEPT THIS POTENTIAL SOMEWHAT VAGUE IN HWO FOR THE
TIME BEING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE/AVIATION...HEINLEIN
PREVIOUS UPDATE...PFANNKUCH
SHORT TERM...JCB
LONG TERM...ROSSI
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1225 PM CDT TUE MAY 1 2012
.AVIATION...18Z TAFS FOR KOMA...KLNK AND KOFK. THUNDERSTORM
DEVELOPMENT IS THE PRIMARY CONCERN AT ALL TAF SITES. BELIEVE THAT
A COMPLEX OF STORMS SHOULD DEVELOP ALONG A COLD FRONT NORTHWEST OF
KOFK LATE THIS AFTERNOON...THEN AFFECT THAT SITE FROM ABOUT
00-04Z...THEN ROLL/DEVELOP EAST SOUTHEAST AND AFFECT KLNK/KOMA
FROM ABOUT 04-09Z. UNTIL THEN...VFR CONDITIONS...WITH SOUTH
SOUTHWEST WINDS AT 16 TO 18 SUSTAINED...WITH GUSTS UP TO 26 TO
28KTS. AFTER THE STORMS MOVE THROUGH...SOME MVFR FOG OR HAZE COULD
DEVELOP FROM ABOUT 09Z-15Z. COULD ALSO SOME SEE SOME LOWER MVFR
STRATO CLOUDS DEVELOPING OVERNIGHT AS WELL.
DEWALD
&&
.PREV DISCUSSION... /ISSUED 956 AM CDT TUE MAY 1 2012/
DISCUSSION...
IN THE MORNING UPDATE OF THE FORECAST, ADDED IN A SMALL CHANCE OF
THUNDERSTORMS ACROSS EXTREME SOUTHEAST NEBRASKA AND SOUTHWEST
IOWA. WEAK WAVE MOVING THROUGH THE REGION...IN CONJUNCTION WITH A
VERY SUBTLE SURFACE TROUGH WAS TRIGGERING SOME CONVECTION IN
NORTHEAST KANSAS. LATEST VISIBLE SATELLITE IMAGERY INDICATES AN
ACCAS FIELD MOVING THROUGH SOUTHEAST NEBRASKA WITH SOME VERTICAL
DEVELOPMENT BETWEEN FALLS CITY AND AND BEATRICE. LATEST HRRR MODEL
SUGGESTS THAT THIS COULD DEVELOP YET THIS MORNING...AND REGIONAL
88DS HAVE SHOWN SOME MID LEVEL DEVELOPMENT JUST SOUTH OF FALLS CITY.
OTHERWISE...REMAINDER OF THE FORECAST SEEMS ON TRACK...WITH
CONVECTIVE DEVELOPMENT POSSIBLE LATER THIS AFTERNOON ACROSS
EXTREME NORTHEAST NEBRASKA ALONG AN ADVANCING COLD FRONT. 12Z NAM
AND 06Z GFS AND 09Z SREF ALSO SUGGEST THAT ISOLATED ACTIVITY
COULD DEVELOP IN THE WARM AIR ADVECTION ZONE AHEAD OF THE COLD
FRONT. HAVE NOT BOUGHT INTO THAT YET...BUT WILL DO FURTHER
ANALYSIS.
DEWALD
PREV DISCUSSION... /ISSUED 333 AM CDT TUE MAY 1 2012/
DISCUSSION...
MAIN FORECAST CONCERN IS CONVECTIVE POTENTIAL TODAY AND TOMORROW.
SUBJECTIVE 00Z UPPER AIR ANALYSIS INDICATES BROADLY ZONAL FLOW
ACROSS THE CONUS...WITH A TROUGH DIGGING INTO THE PACIFIC
NORTHWEST. STRONGEST UPPER-LEVEL JET WAS FOCUSED JUST
OFFSHORE...WITH 110KT JET STREAK JUST OFF THE OR COAST. SEVERAL
WEAK SHORTWAVES WERE RIPPLING THROUGH THE FLOW...INCLUDING ONE IN
AZ...ANOTHER IN SW TX...AND ANOTHER IN WY/CO. AHEAD OF AN 850MB
TROUGH DEVELOPING IN THE LEE OF THE ROCKIES...MOISTURE WAS FLOWING
OFF THE GULF...WITH 8C+ DEWPOINTS NOSING INTO NORTHERN KS/CENTRAL
MO...AND 12C+ DEWPOINTS CLOSE BEHIND. STRONG MID-LEVEL LAPSE RATES
WERE NOTED ACROSS THE ROCKIES INTO THE HIGH PLAINS...WITH 700-500MB
TEMPERATURE DIFFERENCES OF 20-24C PEAKING IN CO/NM. SURFACE LOW
ALSO WAS DEVELOPING IN THE LEE OF THE ROCKIES...WITH LOW CENTERED IN
WESTERN SD AND SECONDARY LOW IN SOUTHWEST CO.
FOCUS IS ON CONVECTIVE POTENTIAL THIS EVENING/TONIGHT...THEN AGAIN
TOMORROW LATE AFTERNOON/EVENING/OVERNIGHT. WARMING MID-LEVEL
TEMPERATURES WILL CREATE A CAP TODAY...AND ALL MODELS EXCEPT THE NAM
AND SOME SREF MEMBERS KEEP THE CWA CAPPED THROUGH 00Z. HAVING
TROUBLE FINDING A REASON TO FOLLOW THE NAM...WITH MODELS INDICATING
RISING MID-LEVEL TEMPS...AND HAVE FOLLOWED CLOSER TO GFS/ECMWF
SOLUTION. IF ANY SURFACE-BASED STORMS DID DEVELOP IN THE
AFTERNOON...LOW-LEVEL FLOW AND 0-1KM SHEAR LOOK RATHER WEAK...BUT
DEEP-LAYER SHEAR IS STRONG ENOUGH TO SUPPORT SUPERCELLS.
THUS...THINK ANY STRAY AFTERNOON STORMS WOULD CARRY MAINLY A HAIL
AND WIND THREAT. WITH THE MORE LIKELY SCENARIO OF EVENING
THUNDERSTORMS MOVING INTO THE CWA...AND LIKELY ELEVATED...THINK THE
MAIN RISK WOULD BE HAIL. THUNDERSTORMS ARE LIKELY TO DEVELOP AND
MOVE ACROSS THE AREA OVERNIGHT...BUT DO THINK THEY SHOULD CLEAR
THROUGH BY DAYBREAK.
ON WEDNESDAY...FRONTAL BOUNDARY IS PROGGED TO STALL AND LINGER
ACROSS CENTRAL TO NORTHEAST NEB...PROVIDING A FOCUS FOR THUNDERSTORM
DEVELOPMENT ON WEDNESDAY. CAP REMAINS A CONCERN...BUT GFS/ECMWF
ARE A LITTLE MORE INCLINED TO ERODE THE CAP IN THE LATE
AFTERNOON...WITH CONVECTION BREAKING OUT ALONG THE BOUNDARY BETWEEN
21-00Z. AGAIN...LOW-LEVEL WINDS REMAIN ON THE WEAK SIDE...BUT
PRESENCE OF A BOUNDARY COULD PROVIDE A SOURCE OF LOW-LEVEL
VORTICITY...INDICATING MORE OF A TORNADO POTENTIAL ON WEDNESDAY...AS
WELL AS HAIL AND WIND THREATS AS DEEP-LAYER SHEAR REMAINS ADEQUATE
TO SUPPORT SUPERCELLS. DO THINK THAT CONVECTION WILL DEVELOP INTO A
COMPLEX AHEAD OF THE FRONT THROUGH THE NIGHT...WITH FRONT FOLLOWING
LATE WEDNESDAY NIGHT/THURSDAY MORNING. HAVE TRIED TO PUSH
CONVECTION OUT A LITTLE FASTER ON THURSDAY...THOUGH ONCE
AGAIN...FRONT HANGS UP IN OR NEAR THE CWA. STORMS MAY DEVELOP AGAIN
ALONG THAT FRONT AND MOVE INTO THE SOUTHERN CWA ON FRIDAY.
FRIDAY AND BEYOND...FORECAST BECOMES MUDDY. KEPT FRIDAY THROUGH
SATURDAY MAINLY DRY AS MID TO UPPER-LEVEL RIDGING BUILDS OVER THE
CENTRAL PLAINS...WITH THE EXCEPTION OF A SMALL AREA OF CHANCE POPS
IN THE NORTHERN CWA ON FRIDAY NIGHT AS RAIN IN SD/MN APPROACHES THE
BORDER AREA. TEMPERATURES WILL WARM THROUGH THE PERIOD WITH THE
RISING 500MB HEIGHTS...AND WITH PERSISTENT LOW-LEVEL
MOISTURE...SHOULD FEEL QUITE MUGGY. THOUGH MODEL BLENDS AND
COORDINATION WITH NEIGHBORS KEEPS PRECIP IN THE FORECAST SATURDAY
NIGHT THROUGH TUESDAY...BELIEVE THAT THIS IS NOT REPRESENTATIVE OF
HOW THE PATTERN WILL EVOLVE. STRONG UPPER-LEVEL RIDGE WILL SHIFT
EAST OF THE CWA AS UPPER LOW DEEPENS IN THE SOUTHWESTERN US...AND AS
THE LOW STRENGTHENS...SEVERAL SHORTWAVES MAY EJECT AHEAD OF
IT...BRINGING TRANSIENT CHANCES FOR SHOWERS AND THUNDERSTORMS
ACROSS THE CENTRAL PLAINS. MODELS HAVE LITTLE AGREEMENT ON THE
TIMING OF THESE WAVES...AND THUS THE BLENDS CREATE A FORECAST LOADED
WITH PRECIPITATION CHANCES WHEN ONLY A COUPLE OF PERIODS WILL LIKELY
SEE RAIN. BEST CHANCE FOR WIDESPREAD AND PERSISTENT RAIN WOULD BE
WHEN THE UPPER LOW EVENTUALLY EJECTS ACROSS THE CENTRAL PLAINS...BUT
FOR NOW...THIS IS OUTSIDE THE FORECAST PERIOD.
MAYES
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
155 PM EDT TUE MAY 1 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL SAG ACROSS THE REGION THIS MORNING WITH
HIGH PRESSURE BRIEFLY BUILDING INTO THE REGION. A WARM FRONT WILL
LIFT NORTHWARD TONIGHT WITH HIGH PRESSURE OVER THE SOUTHEASTERN
UNITED STATES BECOMING THE DOMINATE FEATURE BY THURSDAY. LOW
PRESSURE WILL MOVE ACROSS THE CENTRAL LAKES INTO QUEBEC ON FRIDAY
WITH A COLD FRONT MOVING ACROSS THE REGION BY SATURDAY MORNING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED TO SHOWERS AND THUNDERSTORMS TO GRIDS BASED ON HRRR AND
TIMING OF PRECIP TO OUR WEST. HRRR A BIT SLOWER INTO WESTERN
COUNTIES OF THE CWA THAN SATELLITE AND RADAR BASED TIMING.
ESSENTIALLY FOLLOWED RADAR BASED TIMING INTO THE WEST AND THEN
CONTINUED THAT ACROSS THE CWA...INTERPOLATING INTO THE OVERNIGHT`S
POPS. ALSO ADJUSTED HIGHS AGAIN BASED ON HRRR.
PREVIOUS DISCUSSION...
A WEAK COLD FRONT WILL SAG ACROSS THE REGION THIS MORNING WITH
HIGH PRESSURE AT LEAST BRIEFLY TAKING CONTROL. THE GREATEST
UNCERTAINTY FOR THE DAY IS THE AMOUNT OF CLOUD COVER THAT WILL
PERSIST IN THE WAKE OF THE FRONT. THIS WILL HAVE SIGNIFICANT
IMPLICATIONS ON HIGH TEMPERATURES. AT THIS POINT IT APPEARS WE
WILL SEE AT LEAST SOME SUNSHINE FOR THE AFTERNOON WITH HIGHS
GENERALLY IN THE 70 TO 75 RANGE...COOLER ACROSS NW PA. HOWEVER IF
THE CLOUDS PERSIST THEN WE WILL NEED TO TRIM 4 TO 6 DEGREES FROM
THE CURRENT FORECAST.
THERE HAS BEEN A FEW AREAS OF DRIZZLE/SPRINKLES AS THE WEAK FRONT
MOVES ACROSS NW OH. BELIEVE THIS WILL CONTINUE AS IT SAGS TO THE
SOUTHEAST. PLAN TO COVER THE DRIZZLE AND PATCHY FOG WITH SHORT
TERM FORECASTS IF IT CONTINUES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
A WARM FRONT WILL MOVE TOWARD THE REGION TONIGHT WITH INCREASING
CHANCES OF SHOWERS AND THUNDERSTORMS NEAR AND NORTH OF IT. SHEAR
AND INSTABILITY LOOK RATHER WEAK SO WILL NOT MENTION ANY SEVERE
THUNDERSTORMS FOR THE OVERNIGHT HOURS. THE CHANCES OF
THUNDERSTORMS WILL CONTINUE INTO WEDNESDAY AS WE AWAIT A SURGE OF
HOT AND HUMID AIR TO ARRIVE ON THURSDAY. THURSDAY SHOULD END UP
BEING A DRY DAY WITH HIGHS SURGING WELL INTO THE 80S. STILL LOOKS
AS IF A FEW LOCATIONS MAY REACH 90. AS A COLD FRONT MOVES CLOSER
TO THE REGION LATE FRIDAY INTO FRIDAY NIGHT THERE WILL ONCE AGAIN
BE AN INCREASE OF SHOWERS AND THUNDERSTORMS. FRIDAY EVENING INTO THE
OVERNIGHT HOURS MAY BRING A ROUND OF SEVERE THUNDERSTORMS. MORE ON
THIS THROUGH THE WEEK.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
BELOW NORMAL CONFIDENCE FOR THE WEEKEND FORECAST WITH CONSIDERABLE
DIFFERENCES BETWEEN THE LONG RANGE MODELS. THE GFS IS AN OUTLIER
WITH A STRONG UPPER LEVEL TROUGH PUSHING SOUTH ACROSS QUEBEC ON
SUNDAY WHILE THE ECMWF/GEM/UKMET MAINTAIN AN UPPER LEVEL RIDGE OVER
THE GREAT LAKES REGION. HAVE TRENDED THE FORECAST TOWARDS THE BETTER
CONSENSUS...MAINTAING A WARM AIRMASS OVER THE REGION WITH A
CONTINUED CHANCE OF THUNDERSTORMS.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
A RATHER ACTIVE WEATHER PATTERN EXPECTED THROUGH THE TAF PERIOD
ACROSS ALL SITES. A FRONTAL BOUNDARY IS LOCATED OVER SOUTHERN OHIO
THIS AFTERNOON WITH SURFACE HIGH PRESSURE OVER LAKE ERIE.
MEANWHILE... A THUNDERSTORM COMPLEX OVER INDIANA IS EXPECTED TO
CONTINUE MOVING EAST NORTHEAST THROUGH THIS EVENING AND INTO
TONIGHT WHICH IS EXPECTED TO BRING THE CHANCES OF TS ESPECIALLY
ACROSS WESTERN SITES...BUT UNSURE AS TO HOW FAR EAST THUNDERSTORMS
EMBEDDED IN THE RAIN WILL PERSIST. HOWEVER...LOOKS LIKELY THAT
RAIN ASSOCIATED WITH THIS WILL MOVE ACROSS SITES THIS EVENING AND
INTO TONIGHT. ALSO THROUGH TONIGHT...THE BOUNDARY SOUTH OF THE
AREA WILL BEGIN MOVING NORTH AS A WARM FRONT AND CROSS MOST
LOCATIONS BY 18Z WED. AFTER THE RAIN MOVES THROUGH TONIGHT
INCLUDED ADDITIONAL PERIODS OF IFR CONDITIONS. MODELS NOT IN
COMPLETE AGREEMENT ON THIS SOLUTION BUT WITH THE FRONT PUSHING
NORTHWARD THINKING THAT THERE IS AT LEAST THE CHANCE FOR SOME IFR
ACROSS SITES TONIGHT AND PERHAPS EVEN INTO WED MORNING. AS THE
FRONT MOVES NORTH OF SITES SOUTHERLY WINDS WILL BECOME MORE
PREDOMINATE AND CIG EXPECTED TO BECOME VFR TOWARD THE END OF THE
FCST PERIOD. ERI WILL BE MOST LIKELY TO CONTINUE IFR THROUGH
MIDDAY WED.
.OUTLOOK...NON-VFR CONDITIONS POSSIBLE THURSDAY MORNING....THEN
AGAIN IN CONVECTION FRIDAY AFTERNOON AND EVENING.
&&
.MARINE...
WEAK LOW PRESSURE NEAR EASTERN LAKE ERIE WILL TRACK TO THE EAST
COAST TODAY. LIGHT SOUTHERLY WINDS WILL DEVELOP IN THE WAKE OF THIS
SYSTEM THIS AFTERNOON...PUSHING A WARM FRONT NORTH ACROSS THE LAKE
OVERNIGHT. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL LIKELY
ACCOMPANY THE FRONT. A VERY WARM AIRMASS WILL BE OVER THE LAKE FOR
THE END OF THE WEEK WITH A WEAK FRONTAL BOUNDARY SAGGING SOUTH
DURING THE FRIDAY TO SATURDAY TIME FRAME. THIS FRONT WILL AGAIN BE A
FOCUS FOR SHOWERS AND THUNDERSTORMS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MULLEN
NEAR TERM...TK/MULLEN
SHORT TERM...MULLEN
LONG TERM...KEC
AVIATION...ABE
MARINE...KEC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1235 PM EDT TUE MAY 1 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL SAG ACROSS THE REGION THIS MORNING WITH
HIGH PRESSURE BRIEFLY BUILDING INTO THE REGION. A WARM FRONT WILL
LIFT NORTHWARD TONIGHT WITH HIGH PRESSURE OVER THE SOUTHEASTERN
UNITED STATES BECOMING THE DOMINATE FEATURE BY THURSDAY. LOW
PRESSURE WILL MOVE ACROSS THE CENTRAL LAKES INTO QUEBEC ON FRIDAY
WITH A COLD FRONT MOVING ACROSS THE REGION BY SATURDAY MORNING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED TO SHOWERS AND THUNDERSTORMS TO GRIDS BASED ON HRRR AND
TIMING OF PRECIP TO OUR WEST. HRRR A BIT SLOWER INTO WESTERN
COUNTIES OF THE CWA THAN SATELLITE AND RADAR BASED TIMING.
ISSENTIALLY FOLLOWED RADAR BASED TIMING INTO THE WEST AND THEN
CONTINUED THAT ACROSS THE CWA...INTERPOLATING INTO THE OVERNIGHT`S
POPS. ALSO ADJUSTED HIGHS AGAIN BASED ON HRRR.
PREVIOUS DISCUSSION...
A WEAK COLD FRONT WILL SAG ACROSS THE REGION THIS MORNING WITH
HIGH PRESSURE AT LEAST BRIEFLY TAKING CONTROL. THE GREATEST
UNCERTAINTY FOR THE DAY IS THE AMOUNT OF CLOUD COVER THAT WILL
PERSIST IN THE WAKE OF THE FRONT. THIS WILL HAVE SIGNIFICANT
IMPLICATIONS ON HIGH TEMPERATURES. AT THIS POINT IT APPEARS WE
WILL SEE AT LEAST SOME SUNSHINE FOR THE AFTERNOON WITH HIGHS
GENERALLY IN THE 70 TO 75 RANGE...COOLER ACROSS NW PA. HOWEVER IF
THE CLOUDS PERSIST THEN WE WILL NEED TO TRIM 4 TO 6 DEGREES FROM
THE CURRENT FORECAST.
THERE HAS BEEN A FEW AREAS OF DRIZZLE/SPRINKLES AS THE WEAK FRONT
MOVES ACROSS NW OH. BELIEVE THIS WILL CONTINUE AS IT SAGS TO THE
SOUTHEAST. PLAN TO COVER THE DRIZZLE AND PATCHY FOG WITH SHORT
TERM FORECASTS IF IT CONTINUES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
A WARM FRONT WILL MOVE TOWARD THE REGION TONIGHT WITH INCREASING
CHANCES OF SHOWERS AND THUNDERSTORMS NEAR AND NORTH OF IT. SHEAR
AND INSTABILITY LOOK RATHER WEAK SO WILL NOT MENTION ANY SEVERE
THUNDERSTORMS FOR THE OVERNIGHT HOURS. THE CHANCES OF
THUNDERSTORMS WILL CONTINUE INTO WEDNESDAY AS WE AWAIT A SURGE OF
HOT AND HUMID AIR TO ARRIVE ON THURSDAY. THURSDAY SHOULD END UP
BEING A DRY DAY WITH HIGHS SURGING WELL INTO THE 80S. STILL LOOKS
AS IF A FEW LOCATIONS MAY REACH 90. AS A COLD FRONT MOVES CLOSER
TO THE REGION LATE FRIDAY INTO FRIDAY NIGHT THERE WILL ONCE AGAIN
BE AN INCREASE OF SHOWERS AND THUNDERSTORMS. FRIDAY EVENING INTO THE
OVERNIGHT HOURS MAY BRING A ROUND OF SEVERE THUNDERSTORMS. MORE ON
THIS THROUGH THE WEEK.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
BELOW NORMAL CONFIDENCE FOR THE WEEKEND FORECAST WITH CONSIDERABLE
DIFFERENCES BETWEEN THE LONG RANGE MODELS. THE GFS IS AN OUTLIER
WITH A STRONG UPPER LEVEL TROUGH PUSHING SOUTH ACROSS QUEBEC ON
SUNDAY WHILE THE ECMWF/GEM/UKMET MAINTAIN AN UPPER LEVEL RIDGE OVER
THE GREAT LAKES REGION. HAVE TRENDED THE FORECAST TOWARDS THE BETTER
CONSENSUS...MAINTAING A WARM AIRMASS OVER THE REGION WITH A
CONTINUED CHANCE OF THUNDERSTORMS.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
WEAK LOW PRESSURE HAS SLID EAST INTO NEW YORK AND PENNSYLVANIA THIS
MORNING WITH AMPLE LOW LEVEL MOISTURE IN PLACE BEHIND IT. A FEW
LIGHT SHOWERS/DRIZZLE WILL CONTINUE TO IMPACT YNG/ERI THROUGH 14Z
BEFORE STARTING TO DRY OUT. ELSEWHERE CONDITIONS HAVE VARIED BETWEEN
IFR/MVFR EARLY THIS MORNING...BUT CEILINGS SHOULD LIFT INTO THE MVFR
RANGE BY AROUND 15Z. FORECAST CHALLENGE IS IF AND WHEN LOW CLOUDS
WILL SCATTER OUT TODAY. MODELS SOUNDINGS SHOW MOISTURE DEPTH
DECREASING WITH CLOUDS SCATTERING OUT BY EARLY AFTERNOON. HAVE BEEN
JUST A TOUCH MORE PESSIMISTIC WITH THE CLEARING TREND GIVEN HIGH
CLOUDS ARE ALREADY ARRIVING FROM THE WEST...BUT STILL EXPECT
RETURN TO VFR THIS AFTERNOON. THE WARM FRONT WILL LIFT NORTH TOWARDS THE
REGION TONIGHT WITH SHOWERS AND SCATTERED THUNDERSTORMS ARRIVING
AFTER 04Z WEST/08Z EAST.
.OUTLOOK...NON-VFR CONDITIONS POSSIBLE WITH SHOWERS AND
THUNDERSTORMS INTO WEDNESDAY MORNING...THEN AGAIN FROM FRIDAY
INTO SATURDAY.
&&
.MARINE...
WEAK LOW PRESSURE NEAR EASTERN LAKE ERIE WILL TRACK TO THE EAST
COAST TODAY. LIGHT SOUTHERLY WINDS WILL DEVELOP IN THE WAKE OF THIS
SYSTEM THIS AFTERNOON...PUSHING A WARM FRONT NORTH ACROSS THE LAKE
OVERNIGHT. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL LIKELY
ACCOMPANY THE FRONT. A VERY WARM AIRMASS WILL BE OVER THE LAKE FOR
THE END OF THE WEEK WITH A WEAK FRONTAL BOUNDARY SAGGING SOUTH
DURING THE FRIDAY TO SATURDAY TIME FRAME. THIS FRONT WILL AGAIN BE A
FOCUS FOR SHOWERS AND THUNDERSTORMS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MULLEN
NEAR TERM...TK/MULLEN
SHORT TERM...MULLEN
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1027 AM PDT Tue May 1 2012
.SYNOPSIS...
A number of weather disturbances will move over the area this
week. The result will be below normal temperatures and occasional
intervals of rain showers in valleys with rain and snow showers
over mountains. Light snow accumulations are possible in the
mountains from time to time. Breezy to locally windy conditions
are also expected at various times for much of the week.
&&
.DISCUSSION...
A weak wave passing through the Central Panhandle Mountains of
Idaho this morning will provide a focus for an organized area of
showers. Snow levels will be near 3500 feet supporting some snow
on Fourth of July and Lookout Passes but given time of year it is
not expected to stick to roadways. Otherwise expect an increase in
showers this afternoon due to a cold pool aloft over the area of
-25 to -27C at 500mb, and afternoon heating which will destabilize
the atmosphere. As 850mb winds back to the southwest in advance of
an approaching wave off the Washington coast, upslope winds will
enhance shower activity over the Northern Mountains. HRRR model
data supports this idea with numerous showers over this area while
scattered light showers develop elsewhere. Exception to this is
the lee of the Cascades where downslope flow will keep the Methow
and Wenatchee River valleys dry as well as the Moses Lake area.
GFS model also continue to argue a minimal threat for
thunderstorms this afternoon near the Canadian border. Given
marginal instability for thunder opted to leave mention out of
forecast. But an isolated lightning strike is not out of the
question today. JW
&&
.AVIATION...
18Z TAFS: A cool and moderately unstable air mass will promote
widespread fields of low VFR or high MVFR cumulus ceilings over
the eastern TAF sites today...with scattered showers developing
during the afternoon and early evening hours. A short wave
disturbance will cross the Cascades this evening and move through
the Columbia Basin overnight. This wave will trigger more
showers...mainly isolated north of Interstate 90...but scattered
south of I-90 which may bring a shower through the KPUW TAF site
after 06Z. During this time of day...showers could be snow or a
mix of rain or snow with mVFR ceilings and visibilities. /MJF
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 54 35 54 37 50 40 / 40 40 40 10 80 50
Coeur d`Alene 51 35 51 36 50 41 / 40 40 60 10 80 70
Pullman 51 34 51 37 51 40 / 20 20 30 10 80 70
Lewiston 59 41 59 41 60 44 / 10 10 10 10 80 70
Colville 59 36 58 36 54 41 / 60 50 50 10 80 70
Sandpoint 49 35 49 34 51 39 / 70 60 60 10 80 80
Kellogg 45 35 46 33 49 38 / 90 50 70 10 80 70
Moses Lake 62 37 62 40 59 41 / 10 10 10 10 60 30
Wenatchee 59 41 60 42 56 44 / 10 10 10 30 60 30
Omak 62 33 62 38 56 40 / 10 30 10 10 80 60
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1204 PM MDT TUE MAY 1 2012
.AVIATION...18Z TAFS. THROUGH 02Z...ISOLATED TO SCATTERED SHOWERS
ALONG WITH ISOLATED THUNDERSTORMS PRODUCING LOCALIZED MVFR...
OTHERWISE VFR. SHOWERS DECREASING IN COVERAGE AFTER 02Z. INCREASING
MIDDLE AND HIGH CLOUDS AFTER 06Z WITH ISOLATED TO SCATTERED
SHOWERS DEVELOPING WEST OF A DOUGLAS TO LARAMIE LINE PRODUCING
LOCALIZED MVFR AND MOUNTAIN OBSCUREMENT...VFR ELSEWHERE. SHOWERS
SPREADING SLOWLY EAST AFTER 12Z...WEST OF AN ALLIANCE TO LARAMIE
LINE. RUBIN
&&
.PREV DISCUSSION... /ISSUED 1051 AM MDT TUE MAY 1 2012/
DISCUSSION...
SHOWERS...GENERALLY SPRINKLES...CONTINUE THIS AT MID MORNING OVER
THE PANHANDLE AS WELL AS UNDER THE BAROCLINIC CLOUD BAND FROM CARBON
TO CONVERSE COUNTIES. A SHORTWAVE AT MID MORNING EXTENDED FROM
NORTHEAST TO SOUTH CENTRAL WYOMING...WITH THE CLOUDS AND SHOWERS
AHEAD OF THE FEATURE. MODELS MOVE THE SHORTWAVE TROUGH EAST AND
THROUGH THE ENTIRE CWA THIS EVENING. AN ASSOCIATED SURFACE COLD
FRONT WAS THROUGH ALL BUT THE SOUTHERN PANHANDLE AT 16Z. WEST TO
NORTHWEST WINDS BEHIND THE FRONT WILL GUST AS HIGH AS 45 MPH.
BUMPED UP POPS SLIGHTLY FOR THE REST OF THE DAY AND OTHERWISE MADE
ONLY MINOR CHANGES TO THE FIRST PERIOD OF THE FORECAST IN A RECENT
UPDATE.
AVIATION...12Z TAFS...
VFR CONDITIONS FOR MOST LOCATIONS...THE EXCEPTION BEING KRWL.
LATEST HRRR GUIDANCE CONTINUES TO FORECAST MVFR CONDITIONS OUT
THAT WAY AS A COLD FRONT APPROACHES. LOOK FOR LOWERING CONDITIONS
AROUND THE 15Z TIME FRAME. WILL CONTINUE TO MONITOR FOR ANY LOWER
CONDITIONS. EXPECT AFTERNOON CONVECTION ACROSS SOUTHEAST WYOMING.
HARD TO PINPOINT EXACT TIMING AND LOCATION...SO WILL CONTINUE VCTS
WORDING IN TAFS.
PREV DISCUSSION... /ISSUED 214 AM MDT TUE MAY 1 2012/
SHORT TERM...TODAY THROUGH THURSDAY...
A GENERALLY WEST-SOUTHWESTERLY FLOW ALOFT WILL REMAIN OVER THE CWA
THIS PERIOD WITH A FEW WEAK IMPULSES EMBEDDED IN THIS FLOW PASSING
ACROSS OVER THE NEXT FEW DAYS. ONE IMPULSE WILL PASS ACROSS THIS
AFTERNOON AND EVENING AND SHOULD BRING SOME SHOWERS AND MAYBE A
COUPLE WEAK STORMS TO MAINLY THE MOUNTAINS...WITH A FEW STRAYING
OVER THE HIGH PLAINS. A BETTER CHANCE FOR ACTIVITY ON WEDS AS A
JET STREAK SHOULD RIDE ACROSS AHEAD OF A MORE SIGNIFICANT
SHORTWAVE THAT WILL MOVE ACROSS IDAHO INTO MONTANA AND NRN
WYOMING. INSTABILITIES REMAINING RATHER LOW SO EXPECT MAINLY
SHOWERS ALONG WITH ISOLATED STORMS. CLEARING OUT FOR A TIME WEDS
NIGHT INTO THURSDAY THEN SHOULD SEE SOME MORE ACTIVITY DEVELOP
INITIALLY OVER THE MOUNTAINS AS WEAK SFC BOUNDARY PUSHES AGAINST
THE MTNS AND ENHANCES UPSLOPE FLOW...WITH SCTD SHOWERS AND TSTRMS
SPREADING OVER THE PLAINS BY LATE IN THE DAY.
ONLY OTHER THING TO MENTION WILL BE SOME GUSTY WINDS AROUND THE
MTNS TODAY AS DECENT MID-LEVEL FLOW MIXES DOWN. SOME GUSTS AROUND
50 MPH POSSIBLE IN WIND-FAVORED AREAS.
LONG TERM...THURSDAY NIGHT THROUGH MONDAY...
LOOKS LIKE A FAIRLY WET EXTENDED PERIOD UPCOMING. FRIDAY LOOKS TO
BE DRY WITH A SLOW MOVING TROUGH OVER THE WEST COAST. BY SATURDAY
AFTERNOON THE GFS IS SHOWING A BACKDOOR FRONT LYING UP AGAINST THE
LARAMIE RANGE WITH MOIST LOW LEVEL SOUTHEASTERLY FLOW INTO THE
PANHANDLE. THIS SET UP SHOULD GIVE US INCREASING CHANCES FOR
SHOWERS AND THUNDERSTORMS AS UPPER SHORTWAVES INTERACT WITH THE
FRONT. BY LATE SUNDAY INTO MONDAY...A FAIRLY POTENT PACIFIC LOW
PRESSURE SYSTEM TRACKS ACROSS SOUTHERN UTAH ON THE GFS. CURRENT
ECMWF KEEPS A MORE PROGRESSIVE OPEN WAVE MONDAY...THEN CLOSES OFF
A LOW TUESDAY MORNING. IT ALSO TRACKS THE LOW FURTHER NORTH THAN
THE GFS...BUT BOTH ARE PAINTING FAIRLY HIGH QPF FOR THE NEBRASKA
PANHANDLE AND AREAS EAST OF THE LARAMIE RANGE. AS A RESULT I WENT
HIGHER ON POPS FOR MONDAY INTO TUESDAY.
FIRE WEATHER...
NO MAJOR CONCERNS ANTICIPATED TODAY THROUGH THURSDAY AS MIN
RELATIVE HUMIDITIES EXPECTED TO REMAIN GENERALLY ABOVE CRITICAL
THRESHOLDS. RECENT RAINS HAVE HELPED TO GREEN UP FUELS SOMEWHAT.
MAIN CONCERN WILL BE GUSTY WINDS THIS AFTERNOON AND AGAIN WEDS
AFTERNOON MAINLY OVER THE LOWER ELEVATIONS OF CARBON COUNTY INTO
ALBANY COUNTY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...RE
LONG TERM/AVIATION...CLAYCOMB
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1051 AM MDT TUE MAY 1 2012
.DISCUSSION...
SHOWERS...GENERALLY SPRINKLES...CONTINUE THIS AT MID MORNING OVER
THE PANHANDLE AS WELL AS UNDER THE BAROCLINIC CLOUD BAND FROM CARBON
TO CONVERSE COUNTIES. A SHORTWAVE AT MID MORNING EXTENDED FROM
NORTHEAST TO SOUTH CENTRAL WYOMING...WITH THE CLOUDS AND SHOWERS
AHEAD OF THE FEATURE. MODELS MOVE THE SHORTWAVE TROUGH EAST AND
THROUGH THE ENTIRE CWA THIS EVENING. AN ASSOCIATED SURFACE COLD
FRONT WAS THROUGH ALL BUT THE SOUTHERN PANHANDLE AT 16Z. WEST TO
NORTHWEST WINDS BEHIND THE FRONT WILL GUST AS HIGH AS 45 MPH.
BUMPED UP POPS SLIGHTLY FOR THE REST OF THE DAY AND OTHERWISE MADE
ONLY MINOR CHANGES TO THE FIRST PERIOD OF THE FORECAST IN A RECENT
UPDATE.
&&
.AVIATION...12Z TAFS...
VFR CONDITIONS FOR MOST LOCATIONS...THE EXCEPTION BEING KRWL.
LATEST HRRR GUIDANCE CONTINUES TO FORECAST MVFR CONDITIONS OUT
THAT WAY AS A COLD FRONT APPROACHES. LOOK FOR LOWERING CONDITIONS
AROUND THE 15Z TIME FRAME. WILL CONTINUE TO MONITOR FOR ANY LOWER
CONDITIONS. EXPECT AFTERNOON CONVECTION ACROSS SOUTHEAST WYOMING.
HARD TO PINPOINT EXACT TIMING AND LOCATION...SO WILL CONTINUE VCTS
WORDING IN TAFS.
&&
.PREV DISCUSSION... /ISSUED 214 AM MDT TUE MAY 1 2012/
SHORT TERM...TODAY THROUGH THURSDAY...
A GENERALLY WEST-SOUTHWESTERLY FLOW ALOFT WILL REMAIN OVER THE CWA
THIS PERIOD WITH A FEW WEAK IMPULSES EMBEDDED IN THIS FLOW PASSING
ACROSS OVER THE NEXT FEW DAYS. ONE IMPULSE WILL PASS ACROSS THIS
AFTERNOON AND EVENING AND SHOULD BRING SOME SHOWERS AND MAYBE A
COUPLE WEAK STORMS TO MAINLY THE MOUNTAINS...WITH A FEW STRAYING
OVER THE HIGH PLAINS. A BETTER CHANCE FOR ACTIVITY ON WEDS AS A
JET STREAK SHOULD RIDE ACROSS AHEAD OF A MORE SIGNIFICANT
SHORTWAVE THAT WILL MOVE ACROSS IDAHO INTO MONTANA AND NRN
WYOMING. INSTABILITIES REMAINING RATHER LOW SO EXPECT MAINLY
SHOWERS ALONG WITH ISOLATED STORMS. CLEARING OUT FOR A TIME WEDS
NIGHT INTO THURSDAY THEN SHOULD SEE SOME MORE ACTIVITY DEVELOP
INITIALLY OVER THE MOUNTAINS AS WEAK SFC BOUNDARY PUSHES AGAINST
THE MTNS AND ENHANCES UPSLOPE FLOW...WITH SCTD SHOWERS AND TSTRMS
SPREADING OVER THE PLAINS BY LATE IN THE DAY.
ONLY OTHER THING TO MENTION WILL BE SOME GUSTY WINDS AROUND THE
MTNS TODAY AS DECENT MID-LEVEL FLOW MIXES DOWN. SOME GUSTS AROUND
50 MPH POSSIBLE IN WIND-FAVORED AREAS.
LONG TERM...THURSDAY NIGHT THROUGH MONDAY...
LOOKS LIKE A FAIRLY WET EXTENDED PERIOD UPCOMING. FRIDAY LOOKS TO
BE DRY WITH A SLOW MOVING TROUGH OVER THE WEST COAST. BY SATURDAY
AFTERNOON THE GFS IS SHOWING A BACKDOOR FRONT LYING UP AGAINST THE
LARAMIE RANGE WITH MOIST LOW LEVEL SOUTHEASTERLY FLOW INTO THE
PANHANDLE. THIS SET UP SHOULD GIVE US INCREASING CHANCES FOR
SHOWERS AND THUNDERSTORMS AS UPPER SHORTWAVES INTERACT WITH THE
FRONT. BY LATE SUNDAY INTO MONDAY...A FAIRLY POTENT PACIFIC LOW
PRESSURE SYSTEM TRACKS ACROSS SOUTHERN UTAH ON THE GFS. CURRENT
ECMWF KEEPS A MORE PROGRESSIVE OPEN WAVE MONDAY...THEN CLOSES OFF
A LOW TUESDAY MORNING. IT ALSO TRACKS THE LOW FURTHER NORTH THAN
THE GFS...BUT BOTH ARE PAINTING FAIRLY HIGH QPF FOR THE NEBRASKA
PANHANDLE AND AREAS EAST OF THE LARAMIE RANGE. AS A RESULT I WENT
HIGHER ON POPS FOR MONDAY INTO TUESDAY.
&&
FIRE WEATHER...
NO MAJOR CONCERNS ANTICIPATED TODAY THROUGH THURSDAY AS MIN
RELATIVE HUMIDITIES EXPECTED TO REMAIN GENERALLY ABOVE CRITICAL
THRESHOLDS. RECENT RAINS HAVE HELPED TO GREEN UP FUELS SOMEWHAT.
MAIN CONCERN WILL BE GUSTY WINDS THIS AFTERNOON AND AGAIN WEDS
AFTERNOON MAINLY OVER THE LOWER ELEVATIONS OF CARBON COUNTY INTO
ALBANY COUNTY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...RE
LONG TERM/AVIATION...CLAYCOMB