Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 05/14/12
AREA FORECAST DISCUSSION...UPDATED
NWS PUEBLO CO
956 PM MDT SUN MAY 13 2012
.UPDATE...
UPDATED FORECAST TO DECREASE POPS ACROSS WESTERN AND NORTHERN
PORTIONS OF THE FORECAST AREA. SCATTERED TO WIDESPREAD SHOWERS
WITH EMBEDDED THUNDERSTORMS WILL CONTINUE ACROSS THE SOUTHEAST
PLAINS THROUGH 06Z BEFORE DIMINISHING ACROSS MOST OF THE AREA BY
09Z. HRRR SEEMS TO HAVE A FAIR HANDLE ON THE PROGRESSION OF THE
PCPN...AND HAVE FOLLOWED IT FOR POPS IN THE LATEST GRID UPDATE. -KT
&&
.AVIATION...
OUTFLOW BOUNDARIES FROM CONVECTION OUT EAST ARE HEADING WESTWARD
TOWARDS KCOS AND KPUB...AND MAY BRING A BRIEF WIND SHIFT FROM AN
EASTERLY DIRECTION TO BOTH TERMINALS BETWEEN 04 AND 06Z. THIS MAY
HELP WITH SOME LOW STRATUS DEVELOPMENT AND WILL CONTINUE TO BE
MONITORED TOWARDS THE 06Z TAF ISSUANCE. -KT
&&
.PREV DISCUSSION... /ISSUED 242 PM MDT SUN MAY 13 2012/
SHORT TERM...
(TONIGHT AND MONDAY)
..ONE LAST CHANCE AT GETTING SOME RAIN...
UPPER LOW CENTER IS DROPPING SOUTH ACROSS WESTERN COLORADO CENTERED
NEAR GRAND JUNCTION AT THE PRESENT TIME. LEFT FRONT QUADRANT
ACTIVITY ASSOCIATED WITH 70 KNOT JETSTREAM MAXIMA MOVING BY TO THE
SOUTH OF THE 4 CORNERS...IS TRIGGERING WIDESPREAD SHOWERS AND
THUNDERSTORMS OVER THE SOUTHERN HALF OF THE FORECAST AREA. NORTHERN
HALF OF THE FORECAST AREA IS BEING AFFECTED BY LIFT ASSOCIATED WITH
UPPER LEVEL DIFFLUENT FLOW AND COLD POOL NEAR UPPER LOW CENTER.
THE 2 FEATURES WILL COMBINE TO GIVE MUCH OF SOUTHERN COLORADO
ANOTHER SHOT AT SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING...
BEFORE EVERYTHING SHIFTS SOUTH INTO NEW MEXICO AFTER MIDNIGHT. SO
FAR TODAY...THERE HAVE BEEN PEA TO HALF INCH SIZE HAIL REPORTS IN AN
AND AROUND THE AREA. A BRIEFLY INTENSE PULSE STORM THAT DEVELOPED
NEAR FLORISSANT EARLIER...HAD A 48 DBZ CORE UP TO ABOUT 34,000 FEET
MSL...MINOR ROTATION...AND A VIL HITTING 30. AT THAT ELEVATION...IN
THIS ENVIRONMENT...WITH A GOOD AMOUNT OF COLD AIR ALOFT...SOME
QUARTER SIZE HAIL WAS CERTAINLY PLAUSIBLE. SAW THIS HAPPEN FROM A
STORM 2 MILES EAST OF SOUTH FORK YESTERDAY. FOR THE REMAINDER OF
THE EVENING...EXPECT SHOWERS AND THUNDERSTORMS TO SPREAD OFF OF THE
MOUNTAINS ONTO THE PLAINS AND CONTINUE EASTWARD...PROBABLY WITH
BETTER SUCCESS THAN LAST NIGHT. ATMOSPHERE IS A BIT LESS STABLE
TODAY AND DEWPOINTS ARE NOW WIDESPREAD LOWER TO UPPER 40S ACROSS THE
PLAINS. THIS SHOULD HELP THE SUCCESS OF THE EVENING CONVECTION
ACROSS THE PLAINS.
MOST ACTIVITY SHOULD SHIFT SOUTH INTO NEW MEXICO BY MIDNIGHT...WITH
JUST SOME LINGERING ACTIVITY SOUTHERN AREAS PAST MIDNIGHT. COULD
SEE SOME PATCHY GROUND FOG IN A LOT OF AREAS TOWARD MORNING AS SKIES
START TO CLEAR. ONCE THE FOG GETS OUT OF HERE IN THE MORNING...WE
SHOULD BE LOOKING AT A MOSTLY SUNNY DAY WITH VERY PLEASANT SEASONAL
SPRING TEMPERATURES. STILL AN ISOLATED STORM CHANCE SOUTHERN
MOUNTAIN AREAS...BUT LIKELY THE EXCEPTION...NOT THE RULE.
THIS JUST IN...JUST HEARD FROM ONE OF OUR HAM RADIO COOPERATORS.
APPARENTLY...THE CELL THAT WAS WARNED ON OVER TELLER COUNTY EARLIER
DROPPED PEA SIZE HAIL...TO A 1 INCH DEPTH...IN A SWATH FROM THE LAKE
GEORGE AREA EASTWARD THROUGH THE FLORISSANT CANYON...TO WITHIN 5
MILES OR SO WEST OF WOODLAND PARK. ALSO GOT A REPORT FROM ANOTHER
SPOTTER 2 MILES NORTH OF WOODLAND PARK OF 1/2 DIAMETER HAIL IN THE
PAST HOUR. SPRINGTIME IS FUN TIME IN THE ROCKIES. LW
LONG TERM...
(MONDAY NIGHT THROUGH NEXT SUNDAY)
REST OF THE WEEK INTO NEXT WEEKEND LOOKS RELATIVELY BENIGN WITH
GENERALLY ABOVE AVERAGE TEMPERATURES AND NO SIGNIFICANT STORMS ON
THE HORIZON.
TUESDAY...SHOULD BE WARM AND DRY AS AN UPPER RIDGE MOVES SEWD
THROUGH CO. TEMPS SHOULD CLIMB INTO THE 80S OVR THE PLAINS...AND
50S-60S FOR THE MTN AREAS. BY WED...FIRST OF A COUPLE SHORT WAVES
MOVES THROUGH FROM THE W. THE TROUGH AXIS LOOKS TO BE MOSTLY EA OF
OUR AREA BY 00Z THU...AND BEST MID LEVEL WINDS AND FORCING LOOK TO
BE FARTHER N...SO STRONGEST AFTERNOON OR EVE CONVECTION AT THIS
POINT LOOKS TO BE MAINLY NE OF OUR CWA. HAVE INTRODUCED LOW POPS
HOWEVER FOR THE ERN PLAINS IN THE LATE AFTERNOON AND EVENING HOURS.
THERE IS JUST ENOUGH BULK SHEAR AND INSTABILITY THAT A COUPLE STRONG
STORMS CANNOT BE RULED OUT.
THE RIDGE REBUILDS THU INTO FRI...AND AGAIN IT SHOULD BE MOSTLY DRY
BOTH DAYS FOR THE ENTIRE AREA...WITH TEMPS IN THE UPPR 80S TO
POSSIBLY NR 90 DEGREES OVR THE PLAINS. NEXT DISTURBANCE MOVES IN
LATE FRI INTO SAT...AND A COLD FRONT ASSOCIATED WITH THIS SYSTEM
WILL PUSH INTO ERN CO SOMETIME ON SAT. SOME POTENTIAL FOR STRONGER
CONVECTION WITH THIS SYSTEM...AS DEEPER MOISTURE WITH HIGHER
DEWPOINTS BEGINS TO SURGE WWD OVR THE PLAINS BY LATE IN THE DAY OR
INTO SUN. NOT VERY CONFIDENT WITH THE MODEL SOLUTIONS FOR THE LATTER
PART OF THE WEEKEND...AS THE GFS AND ECMWF CONTINUE TO BE OUT OF
PHASE BEYOND SAT. 44
AVIATION...
CATTERED THUNDERSTORMS HAVE DEVELOPED OVER THE HIGHER TERRAIN AND
WILL SPREAD ONTO THE PLAINS THROUGH THE REMAINDER OF THE AFTERNOON
INTO THE EVENING. WILL CONTINUE AT LEAST VCTS MENTION ALL TAF SITES
THROUGH 02Z TIME PERIOD...WITH POTENTIAL FOR AT LEAST BRIEF MVFR
CONDITIONS UNDER A FEW OF THE STRONGER STORMS. MAINLY VFR CONDITIONS
SPREADING FROM NORTH TO SOUTH 03Z-06Z TIME FRAME AS TSRA MOVE INTO
NM...THOUGH DUE TO RECENT PRECIPITATION AND LIGHT WINDS...WILL HAVE
TO WATCH FOR PATCHY GROUND FOG DEVELOPMENT AROUND SUNRISE MONDAY...
ESPECIALLY AT KALS AND KPUB. LW
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31/13
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1204 PM MDT SAT MAY 12 2012
.UPDATE...
ISSUED AT 1203 PM MDT SAT MAY 12 2012
A BATTLE BETWEEN THE DRY AIR ALOFT AND THE CONDITIONALLY UNSTABLE
AIR MASS BENEATH THE SUBSIDENT LAYER. THE SUBSIDENT LAYER IS NOT
THAT STRONG BUT NEITHER IS THE CONVECTIVE POTENTIAL. BUILDING
CUMULUS HAS FIRED OVER THE WESTERN SLOPE HIGH TERRAIN BUT NOT A
SINGLE LIGHTNING STRIKE AS OF 1745Z. DO EXPECT THUNDERSTORMS WITH
THE BEST POTENTIAL OVER THE SAN JUANS AND TOWARD THE DIVIDE. BUT
LESSER ACTIVITY FARTHER WEST AND NO STORMS EXPECTED OVER ERN UTAH
(EXCEPT FOR A POSSIBLE LATE DAY STORM OVER THE ERN UINTAS). GRIDS
HAVE BEEN UPDATED TO REFLECT THIS CURRENT THINKING.
CONSIDERATION FOR SUNDAY...CLOSED LOW CIRCULATION WILL BE MOVING
NORTH TO SOUTH. THE NAM SHOWS A TIGHTER CLOSED LOW CIRCULATION BUT
MOISTURE IS LACKING. WILL TAKE A CLOSER EXAMINATION BEFORE THE
MID AFTERNOON FORECAST UPDATE.
UPDATE ISSUED AT 754 AM MDT SAT MAY 12 2012
STRATUS SHROUDS THE UPPER GUNNISON VALLEY THIS MORNING...COVERS
BLUE MESA RESERVOIR AND THE TOWN OF GUNNISON. THESE STRATIFORM
CLOUDS WILL LIFT AND DISSIPATE LATER THIS MORNING...THE
TEMPERATURE AND DEW POINT SPREAD OF 7F AT KGUC SUGGESTS THIS WILL
BE SOONER THAN LATER.
THE HRRR SHOWS CONVECTIVE SHOWERS DEVELOPING OVER THE SAN JUAN
MOUNTAINS...BUT NOTABLY DRY OVER THE NORTHERN AND CENTRAL
MOUNTAINS THIS AFTERNOON. MUCH OF THE FORECAST AREA IS IN A DRY
AND SUBSIDENT AIR MASS THIS MORNING...BUT THIS IS ONLY TEMPORARY
AS THE NEXT UPSTREAM SHORT WAVE WILL BE APPROACHING FROM THE
NORTHWEST THIS AFTERNOON. THE FORECAST MAY BE TOO FAST WITH
SHOWERS AND STORMS REDEVELOPING OVER THE NORTHERN MOUNTAINS...WE
WILL TAKE A LOOK AT THE MODEL SUITE TO CHECK WHETHER OTHER MODELS
SHOW THIS SAME TREND.
&&
.SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 311 AM MDT SAT MAY 12
2012
NEXT UPSTREAM PACIFIC SHORTWAVE TROUGH APPARENT ON SATELLITE
IMAGERY IN SOUTHERN IDAHO. AHEAD OF THAT FEATURE...EXPECT CONVECTION
TO DEVELOP AGAIN OVER OUR CWA THIS AFTERNOON MAINLY NEAR THE
CONTINENTAL DIVIDE...THOUGH NOT AS EXTENSIVE AS ON FRIDAY. MAX
TEMPERATURES TODAY LIKELY TO BE A TAD COOLER ACROSS THE SOUTHERN
THIRD OF OUR CWA...AND SIMILAR TO YESTERDAY ACROSS THE REMAINDER
OF OUR CWA.
THE 00Z NAM HAS COME IN STRONGER WITH THE SHORTWAVE TROUGH THAT IS
PROGGED TO DROP SOUTHWARD ACROSS WY SAT NIGHT...AND THEN PROCEED
ACROSS CO/EASTERN UT ON SUNDAY. THIS SOLUTION IS IN BETTER AGREEMENT
WITH THE GFS THAN THE PREVIOUS RUN. AND BOTH MODELS NOW SEEM TO BE
JUST A LITTLE SLOWER IN MOVING THE SYSTEM SOUTHWARD INTO NM...
KEEPING IT OVER AND JUST SOUTH OF OUR SOUTHERN EDGE THROUGH SUN
EVENING.
EXPECT SCATTERED SHOWERS WILL CONTINUE THROUGH SAT NIGHT AS THIS
SHORTWAVE APPROACHES...MAINLY OVER THE EASTERN MOUNTAINS. THEN BY
SUNDAY THE TROUGH WILL MOVE OVERHEAD FOR AN UPTICK OF ACTIVITY
THROUGH THE DAY AND INTO THE EVENING. WHILE THE EASTERN MOUNTAINS
WILL CONTINUE TO BE FAVORED...WILL EXPAND COVERAGE WESTWARD SOMEWHAT
AS THE NAM SHOWS THE 500 MB LOW DROPPING ALONG THE UT/CO BORDER
THROUGH THE DAY. AN EASTERLY OR DOWNSLOPE COMPONENT QUICKLY FOLLOWS
WITH DIMINISHING ACTIVITY FROM THE NORTH BEGINNING BEFORE SUNSET AS
THE TROUGH AXIS MOVES INTO NM. SHOWERS WILL LINGER LONGEST OVER THE
SOUTHERN DIVIDE.
HIGH PRESSURE WILL BUILD IN FROM THE NORTH AND WEST LATE SUN NIGHT
INTO MONDAY. BY MONDAY AFTERNOON THE HIGH PRESSURE RIDGE WILL BE
JUST UPSTREAM...CENTERED OVER UT WITH DRIER AND WARMER CONDITIONS
FOR OUR CWA.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT 311 AM MDT SAT MAY
12 2012
MIGRATORY UPPER RIDGE SHOULD BE MOVING ACROSS OUR CWA MONDAY NIGHT
AND TUESDAY WITH RELATIVELY DRY CONDITIONS EXCEPT FOR ISOLATED
CONVECTION OVER THE MOUNTAINS. THEN A PACIFIC SHORTWAVE
DISTURBANCE IS STILL EXPECTED TO DRIFT ACROSS OUR AREA ON
WEDNESDAY...FOLLOWED BY ANOTHER DISTURBANCE ON THURSDAY... WHICH
SHOULD RESULT IN A FEW SHOWERS AND THUNDERSTORMS MAINLY OVER THE
MOUNTAINS. THESE FEATURES SHOULD HAVE MINIMAL IMPACT ON
TEMPERATURES...EXCEPT FOR THE INFLUENCE OF ANY CLOUD COVER.
AN INCREASING SW FLOW ALOFT IS STILL EXPECTED OVER OUR CWA ON
FRIDAY AS THE MODELS ARE INDICATING A MORE SIGNIFICANT SHORTWAVE
TROUGH APPROACHING OUR CWA. PRESENTLY...NEXT FRIDAY APPEARS TO BE
A RATHER DRY DAY FOR OUR CWA WITH BREEZY SOUTHERLY SURFACE WINDS.
MAX TEMPERATURES DURING THIS PERIOD SHOULD BE NEARLY 10 DEGREES
ABOVE NORMAL AT MOST LOCATIONS...WITH MIN TEMPERATURES 5 TO 10
DEGREES ABOVE NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1203 PM MDT SAT MAY 12 2012
THE MAIN AVIATION HAZARD WILL BE CONVECTIVE STORMS AND GUSTY
OUTFLOW WINDS. SHOWERS WITH EMBEDDED THUNDERSTORMS WILL HUG THE
HIGHER TERRAIN...BUT A PASSING SHORT LIVED STORM WILL BE IN THE
VICINITY OF KEGE AND KASE. KRIL...KMTJ...AND KGJT COULD EXPERIENCE
GUSTY OUTFLOW WINDS FROM DISTANT STORMS. NO THUNDERSTORMS ARE
EXPECTED OVER ERN UTAH EXCEPT FOR A LATE DAY STORM OVER THE ERN
UINTA MOUNTAINS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...PF
SHORT TERM...EH
LONG TERM...JRP
AVIATION...PF
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
754 AM MDT SAT MAY 12 2012
.UPDATE...
ISSUED AT 754 AM MDT SAT MAY 12 2012
STRATUS SHROUDS THE UPPER GUNNISON VALLEY THIS MORNING...COVERS
BLUE MESA RESERVOIR AND THE TOWN OF GUNNISON. THESE STRATIFORM
CLOUDS WILL LIFT AND DISSIPATE LATER THIS MORNING...THE
TEMPERATURE AND DEW POINT SPREAD OF 7F AT KGUC SUGGESTS THIS WILL
BE SOONER THAN LATER.
THE HRRR SHOWS CONVECTIVE SHOWERS DEVELOPING OVER THE SAN JUAN
MOUNTAINS...BUT NOTABLY DRY OVER THE NORTHERN AND CENTRAL
MOUNTAINS THIS AFTERNOON. MUCH OF THE FORECAST AREA IS IN A DRY
AND SUBSIDENT AIR MASS THIS MORNING...BUT THIS IS ONLY TEMPORARY
AS THE NEXT UPSTREAM SHORT WAVE WILL BE APPROACHING FROM THE
NORTHWEST THIS AFTERNOON. THE FORECAST MAY BE TOO FAST WITH
SHOWERS AND STORMS REDEVELOPING OVER THE NORTHERN MOUNTAINS...WE
WILL TAKE A LOOK AT THE MODEL SUITE TO CHECK WHETHER OTHER MODELS
SHOW THIS SAME TREND.
&&
.SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 311 AM MDT SAT MAY 12
2012
NEXT UPSTREAM PACIFIC SHORTWAVE TROUGH APPARENT ON SATELLITE
IMAGERY IN SOUTHERN IDAHO. AHEAD OF THAT FEATURE...EXPECT CONVECTION
TO DEVELOP AGAIN OVER OUR CWA THIS AFTERNOON MAINLY NEAR THE
CONTINENTAL DIVIDE...THOUGH NOT AS EXTENSIVE AS ON FRIDAY. MAX
TEMPERATURES TODAY LIKELY TO BE A TAD COOLER ACROSS THE SOUTHERN
THIRD OF OUR CWA...AND SIMILAR TO YESTERDAY ACROSS THE REMAINDER
OF OUR CWA.
THE 00Z NAM HAS COME IN STRONGER WITH THE SHORTWAVE TROUGH THAT IS
PROGGED TO DROP SOUTHWARD ACROSS WY SAT NIGHT...AND THEN PROCEED
ACROSS CO/EASTERN UT ON SUNDAY. THIS SOLUTION IS IN BETTER AGREEMENT
WITH THE GFS THAN THE PREVIOUS RUN. AND BOTH MODELS NOW SEEM TO BE
JUST A LITTLE SLOWER IN MOVING THE SYSTEM SOUTHWARD INTO NM...
KEEPING IT OVER AND JUST SOUTH OF OUR SOUTHERN EDGE THROUGH SUN
EVENING.
EXPECT SCATTERED SHOWERS WILL CONTINUE THROUGH SAT NIGHT AS THIS
SHORTWAVE APPROACHES...MAINLY OVER THE EASTERN MOUNTAINS. THEN BY
SUNDAY THE TROUGH WILL MOVE OVERHEAD FOR AN UPTICK OF ACTIVITY
THROUGH THE DAY AND INTO THE EVENING. WHILE THE EASTERN MOUNTAINS
WILL CONTINUE TO BE FAVORED...WILL EXPAND COVERAGE WESTWARD SOMEWHAT
AS THE NAM SHOWS THE 500 MB LOW DROPPING ALONG THE UT/CO BORDER
THROUGH THE DAY. AN EASTERLY OR DOWNSLOPE COMPONENT QUICKLY FOLLOWS
WITH DIMINISHING ACTIVITY FROM THE NORTH BEGINNING BEFORE SUNSET AS
THE TROUGH AXIS MOVES INTO NM. SHOWERS WILL LINGER LONGEST OVER THE
SOUTHERN DIVIDE.
HIGH PRESSURE WILL BUILD IN FROM THE NORTH AND WEST LATE SUN NIGHT
INTO MONDAY. BY MONDAY AFTERNOON THE HIGH PRESSURE RIDGE WILL BE
JUST UPSTREAM...CENTERED OVER UT WITH DRIER AND WARMER CONDITIONS
FOR OUR CWA.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT 311 AM MDT SAT MAY
12 2012
MIGRATORY UPPER RIDGE SHOULD BE MOVING ACROSS OUR CWA MONDAY NIGHT
AND TUESDAY WITH RELATIVELY DRY CONDITIONS EXCEPT FOR ISOLATED
CONVECTION OVER THE MOUNTAINS. THEN A PACIFIC SHORTWAVE
DISTURBANCE IS STILL EXPECTED TO DRIFT ACROSS OUR AREA ON
WEDNESDAY...FOLLOWED BY ANOTHER DISTURBANCE ON THURSDAY... WHICH
SHOULD RESULT IN A FEW SHOWERS AND THUNDERSTORMS MAINLY OVER THE
MOUNTAINS. THESE FEATURES SHOULD HAVE MINIMAL IMPACT ON
TEMPERATURES...EXCEPT FOR THE INFLUENCE OF ANY CLOUD COVER.
AN INCREASING SW FLOW ALOFT IS STILL EXPECTED OVER OUR CWA ON
FRIDAY AS THE MODELS ARE INDICATING A MORE SIGNIFICANT SHORTWAVE
TROUGH APPROACHING OUR CWA. PRESENTLY...NEXT FRIDAY APPEARS TO BE
A RATHER DRY DAY FOR OUR CWA WITH BREEZY SOUTHERLY SURFACE WINDS.
MAX TEMPERATURES DURING THIS PERIOD SHOULD BE NEARLY 10 DEGREES
ABOVE NORMAL AT MOST LOCATIONS...WITH MIN TEMPERATURES 5 TO 10
DEGREES ABOVE NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 311 AM MDT SAT MAY 12 2012
EXPECT VFR CONDITIONS ACROSS MOST OF THE AREA TODAY AND
TONIGHT...EXCEPT FOR SOME EARLY MORNING LOW CLOUDS AND MOUNTAIN
OBSCURATION IN THE EXTREME SOUTHERN PART OF WESTERN CO NEAR THE
CONTINENTAL DIVIDE. SCATTERED SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP THIS AFTERNOON MAINLY OVER THE MOUNTAINS OF
WESTERN COLORADO WITH LOCALIZED MOUNTAIN OBSCURATION/MVFR CIGS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...PF
SHORT TERM...EH
LONG TERM...JRP
AVIATION...JRP
AREA FORECAST DISCUSSION
NWS NEW YORK NY
855 PM EDT SUN MAY 13 2012
.SYNOPSIS...
A COLD FRONT APPROACHES THE NORTHEAST TONIGHT...AND BECOMES NEARLY
STATIONARY JUST WEST OF THE AREA. A WEAK...BROAD AREA OF LOW
PRESSURE SLOWLY MOVES NORTHEAST FROM THE SOUTHEASTERN STATES
STARTING MONDAY...MOVING OVER THE REGION BY WEDNESDAY MORNING. A
COLD FRONT THEN MOVES INTO FAR WESTERN PORTIONS OF THE TRI-STATE
BY LATE WEDNESDAY...THEN CROSSES THE REMAINDER OF THE TRI-STATE
WEDNESDAY NIGHT. HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES FROM
THURSDAY INTO FRIDAY...THEN SLIDES INTO THE CANADIAN
MARITIMES...WHERE IT DOMINATES OUR WEATHER INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
RECENT RADAR TRENDS...AND 15Z SREF/18Z NAM/LATEST HRRR ALL SUGGEST
REGION SHOULD REMAIN DRY THROUGH MIDNIGHT...SO HAVE ADJUSTED
FORECAST ACCORDINGLY. MAINLY SCT-ISOLD -SHRA SHOULD DEVELOP AFTER
MIDNIGHT IN RESPONSE TO APPROACH OF A FAIRLY STRONG 700-500 HPA
SHORTWAVE...WITH FORCING ENHANCED WITH THE DEPARTURE OF A
VORTICITY MINIMUM AHEAD OF IT. WILL ALSO BE IN THE RIGHT REAR
QUADRANT OF AN 80+ KT 300 HPA JET STREAK...WHICH WILL SUPPLY SOME
ADDITIONAL FORCING OVERNIGHT.
BEST FORCING WILL BE OVER FAR NW ZONES...SO HAVE THE HIGHEST POPS
THERE OVERNIGHT - LOW END LIKELY AND ONLY LOW END SLIGHT CHANCE
POPS OVER FAR SE ZONES.
THE MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THE OVERNIGHT LOWS
REMAINING WELL ABOVE NORMAL...WITH 925MB TEMPS NEARING 15 DEGREES
CELSIUS. SHOULD SEE LOWS MAINLY IN THE MID TO UPPER 50S...WITH LOWER
60S IN NYC. THIS IS CONSISTENT WITH A BLEND OF 2/3 MAV/MET
GUIDANCE AND 1/3 NAM 2-METER TEMPERATURE.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
PRECIP TIMING AND INTENSITY REMAINS THE QUESTION FOR THIS PERIOD AS
THE FRONT REMAINS NEARLY STATIONARY OVER CENTRAL NY AND STRONG HIGH
PRESSURE REMAINS SETTLED OVER THE NORTH ATLANTIC. WITH THE BROAD
UPPER LEVEL TROUGH PERSISTING...A VORT MAX LOOKS TO TRAVERSE THE
REGION SOMETIME BETWEEN 12Z AND 18Z MON...BRINGING ENOUGH FORCING
THAT WILL ASSIST IN TRIGGERING SCT SHOWERS. WITH LITTLE TO NO
INSTABILITY EXPECTED...ANY PRECIP SHOULD REMAIN JUST SHOWERS. THE
MODELS DEVELOP A BROAD SURFACE LOW MONDAY AND BRING IT NORTH ALONG
THE FRONT. AS THIS LOW APPROACHES...IT SHOULD GENERATE A STRONG
SOUTH TO SOUTH SOUTHEAST FLOW...INCREASING THE ISENTROPIC
LIFT...RESULTING IN MORE RAIN SHOWERS. HAVE THEREFORE KEPT CHANCE TO
LIKELY POPS OVER THE WESTERN HALF OF THE CWA WITH THE BETTER
FORCING...AND SLIGHT CHANCE TO CHANCE IN THE MORE STABLE EASTERN HALF.
THE SOUTHERLY FLOW WILL FINALLY MOISTEN UP THE LOWER LEVELS...SO
EXPECTING BKN TO OVC SKIES WITH SOME LOWER CLOUDS MOVING IN. THE OVC
SKIES...ALONG WITH ANY PRECIP...AND 925MB TEMPS REMAINING NEAR 12
DEGREES...EXPECTING MUCH COOLER TEMPS MON AND MON NIGHT...ESP ALONG
THE COAST WHERE AN ONSHORE FLOW WILL GENERATE HIGHS ONLY IN THE 60S.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
THERE IS QUITE A BIT OF MODEL SPREAD AS TO WHO MUCH IF ANY
PRECIPITATION THE REGION RECEIVES ON TUESDAY...WITH THE NAM BEING
BASICALLY DRY AND THE ECMWF BEING THE WETTEST AND FARTHEST EAST.
GIVEN THE BLOCKING PATTERN SET UP OVER THE NORTHERN STREAM AND THE
STRENGTH OF THE HIGH TO THE EAST...DO NOT WANT TO COMPLETELY
DISCOUNT THE NAM SOLUTION. SO WENT WITH LIKELY POPS OVER FAR NW
ZONES TO SLIGHT CHANCE POPS OVER FAR SE ZONES. THIS IS ALSO
CONSISTENT WITH ALL MODELS HAVING THE BEST DYNAMICS WITH A 700-500
HPA SHORTWAVE TROUGH THAT LIFTS NE THROUGH THE REGION PASS MAINLY TO
THE NW OF THE CWA. WITH MINIMAL CAPE...THE THETA-E RIDGE FORECAST TO
STAY TO OUR WEST...AND WEAK INSTABILITY ALOFT...HAVE KEPT THUNDER
OUT OF THE FORECAST FOR TUESDAY.
FOR HIGHS TUESDAY USED A BLEND OF 4/5 MAV/MET/MIX FROM 950 NEAR THE
COAST/MIX FROM 900 ACROSS THE INTERIOR AND 1/5 NAM 2-METER
TEMPERATURES. THIS YIELDS VALUES NEAR NORMAL.
TUESDAY NIGHT BRINGS THE BEST CHANCE FOR HEAVY PRECIPITATION TO THE
REGION WITH STRONG ISENTROPIC LIFT FROM THE I-295 TO I-305
SURFACES...A PASSING 700-500 HPA SHORTWAVE AND THE REGION BEING IN
THE RIGHT REAR QUADRANT OF A 80+ KT 300 HPA JET. SO HAVE LIKELY
POPS...WITH A SLIGHT CHANCE OF THUNDER...WITH SHOWALTER INDICES
PROGGED AROUND ZERO. FOR LOWS TUESDAY NIGHT USED A BLEND OF 2/3
MET/MAV AND 1/3 NAM 2-METER TEMPERATURES. THIS YIELDED VALUES AROUND
5 DEGREES ABOVE NORMAL.
HAVE LIKELY POPS E WEDNESDAY MORNING AS THE SURFACE WAVE SLOWLY MOVES
OUT...THIS WILL TAKE THE CORE OF THE LOW LEVEL MOISTURE WITH
IT...LEAVING NOT MUCH BEHIND FOR THE APPROACHING COLD FRONT AND
FAIRLY STRONG 700-500 HPA SHORTWAVE PASSING ACROSS THE REGION TO ACT
ON. SO HAVE POPS IN THE AFTERNOON RANGING FROM SLIGHT CHANCE FAR NW
TO CHANCE ELSEWHERE. DO HAVE A SLIGHT CHANCE OF THUNDER...WITH CAPES
GENERALLY FROM 250-750 J/KG...SHOWALTER INDICES AS LOW AS -2...THE
LOW LEVEL THETA-E RIDGE OVER THE REGION...AND CONTINUATION OF
BEING IN THE RIGHT REAR QUADRANT OF AN 80+ KT 300 HPA JET. FOR
HIGHS WEDNESDAY BLENDED MEX/MEX MEAN GUIDANCE AND NAM 2-METER
TEMPERATURES...WITH A MIX DOWN FROM 925 HPA ACROSS THE INTERIOR
AND 975 HPA AT THE COAST. THIS YIELDS VALUES 3-5 DEGREES ABOVE
NORMAL.
OTHER THAN A CHANCE TO SLIGHT CHANCE OF SHOWERS EARLY...WEDNESDAY
NIGHT SHOULD BE DRY AS THE 700-500 HPA TROUGH AXIS SLIDES TO OUR
EAST.
MODEL DIFFERENCE IN THE EXTENDED WITH THE ECMWF FEATURING WNW-NW
FLOW ALOFT AND THE GFS MORE ZONAL FLOW. THE ECMWF IS ALSO MORE
ROBUST WITH ITS HANDLING OF A COASTAL LOW FORECAST TO DEVELOP OFF
THE SE COAST BY FRIDAY MORNING. THE GFS TAKES THIS SYSTEM OFF WELL
TO OUR EAST THEN NE...WHILE THE ECMWF HAS IT MEANDER OFF THE
CAROLINA COAST. THIS SYSTEM COULD ULTIMATELY END UP PLAYING A ROLE
IN OUR WEATHER...SO WILL HAVE TO CONTINUE TO MONITOR.
FOR NOW...WITH HIGH PRESSURE THE MAIN PLAYER AT THE SURFACE...OTHER
THAN POSSIBLY A BACKDOOR COLD FRONT OR TWO...WENT WITH A DRY
FORECAST THURSDAY-SUNDAY. FOR TEMPERATURES USED A BLEND OF MEX/MEX
ENSEMBLE MEAN GUIDANCE WITH HPC GUIDANCE. THIS YIELDED ABOVE NORMAL
HIGHS AND LOWS NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
TERMINALS REMAIN NESTLED BETWEEN HIGH PRESSURE OFFSHORE AND A
SLOW MOVING COLD FRONT ACROSS NORTHERN/WESTERN NY STATE...WHILE A
WEAK TROF RESIDES CLOSE TO THE AREA. THIS GENERAL SCENARIO SHOULD
NOT CHANGE MUCH OVER THE NEXT 24 HR...WHILE UPPER LEVEL
DISTURBANCES MOVE ACROSS AND CREATE OPPORTUNITIES FOR LOWER CIGS
AND SHOWERS LATE TONIGHT INTO MON MORNING...AND AGAIN MON
AFTERNOON. CONFIDENCE IN SHOWERS ACTUALLY OCCURRING IS HIGH
ENOUGH TO AT LEAST MENTION...BUT EXACT TIMING IS STILL SOMEWHAT IN
QUESTION. CONDITIONS SHOULD BE MOSTLY VFR...BUT AFTERNOON SHOWERS
AT KSWF LOOK MORE LIKELY TO BRING MVFR CONDITIONS.
SOUTHERLY SEA BREEZES WILL DIMINISH EARLY...AND WINDS ACROSS THE
BOARD MAY VEER A LITTLE MORE SW THIS EVENING. WEAKER SEA BREEZE
DEVELOPMENT THAN THAT OF TODAY EXPECTED MON AFTERNOON.
OUTLOOK FOR 00Z TUE THROUGH FRI...
.MON NIGHT-WED...MVFR OR LOWER CONDITIONS POSSIBLE IN SHOWERS.
ISOLD THUNDER POSSIBLE TUE NIGHT-WED.
.WED NIGHT-FRI...VFR.
&&
.MARINE...
MINOR CHANGES IN THE NEAR TERM TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. THE MAIN CHANGE WAS TO REMOVE ALL
MENTION OF PRECIPITATION PRIOR TO MIDNIGHT TONIGHT.
WINDS WILL INCREASE TONIGHT AS THE COLD FRONT APPROACHES THE
COAST...PRODUCING A SOUTHERLY FLOW WITH GUSTS UP TO AROUND 20 KT.
HOWEVER...WITH THE PERSISTENT SOUTHERLY FLOW...UP TO 5 FT SEAS ARE
EXPECTED OVER THE EASTERN TWO COASTAL OCEAN ZONES...SO HAVE
CONTINUED THE SCA FOR HAZARDOUS SEAS INTO MONDAY. DEPENDING ON
WHETHER THE CONDITIONS ARE MET...MAY NEED TO CONTINUE INTO MONDAY
NIGHT AS WELL. ALL OTHER WATERS SHOULD REMAIN BELOW SCA CRITERIA
THROUGH MONDAY NIGHT.
WINDS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY TUESDAY-FRIDAY...AS
THE PRESSURE GRADIENT AND WINDS IN THE LOW LEVELS SUPPORT ONLY WINDS
OF AT MOST 10-15KT WITH GUSTS OF AT MOST 20 KT. HOWEVER...A
PERSISTENT ONSHORE FLOW FROM TUESDAY INTO WEDNESDAY NIGHT WILL KEEP
SEAS AT HAZARDOUS LEVELS ON ALL THE COASTAL OCEAN ZONES...AND
POSSIBLY INTO THURSDAY ON THE WATERS EAST OF MORICHES INLET.
&&
.HYDROLOGY...
THERE WILL BE THE POTENTIAL BETWEEN 1 AND 3 INCHES WITH THE PRECIP
EXPECTED TONIGHT THROUGH INTO WEDNESDAY EVENING. TONIGHT/S AMOUNTS
SHOULD REMAIN LESS THAN A TENTH...WITH THE AMOUNTS PICKING UP
MONDAY DURING THE DAY WITH BETWEEN A QUARTER AND THREE QUARTERS INCH
POSSIBLE THROUGH MONDAY NIGHT. THE HEAVIEST PRECIP IS EXPECTED
FROM LATE TUESDAY INTO WEDNESDAY MORNING...WITH BETWEEN 1 AND 2
INCHES POSSIBLE OVER THE LOWER HUDSON RIVER VALLEY AND
NORTHEASTERN NJ...AND HALF AN INCH TO AN INCH OVER CT...LONG
ISLAND...AND THE NYC METRO AREA.
DUE TO ANTECEDENT DRY CONDITIONS...THERE IS INITIALLY A HIGHER
PROBABILITY OF MINOR URBAN FLOODING THAN MINOR SMALL STREAM
FLOODING...BUT WILL HAVE TO MONITOR FOR TRAINING SHOWER/TSTM
ACTIVITY ACROSS NE NJ AND THE LOWER HUDSON VALLEY MONDAY NIGHT INTO
WEDNESDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT MONDAY
FOR ANZ350.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL NOON EDT MONDAY
FOR ANZ353.
&&
$$
SYNOPSIS...MALOIT/SEARS
NEAR TERM...MALOIT
SHORT TERM...SEARS
LONG TERM...MALOIT
AVIATION...GOODMAN
MARINE...MALOIT/SEARS
HYDROLOGY...MALOIT/SEARS
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
359 PM EDT SAT MAY 12 2012
.SHORT TERM /TONIGHT THROUGH MONDAY/...
MAIN FORECAST CONCERN WILL BE QPF AND POPS ASSOCIATED WITH
DEVELOPING LOW PRESSURE SYSTEM APPROACHING THE FORECAST AREA FROM
THE WEST. MODELS ARE GENERALLY IN GOOD AGREEMENT WITH THIS FEATURE
HOWEVER THE GFS SEEMS TO HAVE A SLIGHTLY BETTER HANDLE ON IT AND
THE ASSOCIATED PRECIPITATION...THEREFORE MADE MINOR TWEAKES TO MAV
INITIALIZATION. HRRR IS SUGGESTING SOME SCATTERED SHOWER
DEVELOPMENT AHEAD OF THE MAIN SWATH AFTER 21Z THIS EVENING...
WHILE THE MORE WIDESPREAD RAIN SHOULD AFFECT THE WESTERN PORTIONS
AFTER ABOUT 03Z. HAVE THEREFORE KEPT CHANCE POPS THIS AFTERNOON
AND INCREASED TO LIKELY AND CATEGORICAL POPS ACROSS THE
NORTHWESTERN HALF OF THE AREA OVERNIGHT. SOME BREAKS IN THE CLOUD
DECK THIS AFTERNOON HAS ALLOWED CAPE VALUES TO INCREASE SOMEWHAT
SO THERE IS STILL A SLIGHT CHANCE FOR THUNDERSTORMS.
SUNDAY LOOKS TO BE THE WETTEST DAY IN THE SHORT TERM WITH THE
HEAVIEST RAINFALL LIKELY OCCURRING IN THE NORTHERN PORTIONS OF THE
AREA DURING THE MORNING AND SUNDAY OVERNIGHT. LATEST 12Z GFS AND NAM
TIME HEIGHTS ALSO SHOW DEEPEST HIGH RH LAYER INFLUENCING THE AREA ON
SUNDAY WITH LESS MOISTURE ON MONDAY THAN PREVIOUSLY THOUGHT. HAVE
THEREFORE MAINTAINED CATEGORICAL POPS IN THE NORTH... LIKELY POPS
CENTRAL... AND HIGH END CHANCE POPS SOUTH THROUGH SUNDAY. MODELS DO
INDICATED A BIT HIGHER CAPE VALUES AFTER 18Z SUNDAY SO HAVE INCLUDED
CHANCE OF THUNDERSTORMS. THE UPPER LEVEL SHORTWAVE TROUGH AXIS
SHOULD SWING THROUGH THE AREA BY AROUND 18Z MONDAY AND THE WEAK COLD
FRONT ASSOCIATED WITH THE PHASED SURFACE LOW SHOULD PASS AROUND 00Z
TUESDAY...THUS ALLOWING FOR CHANCE POPS TO CONTINUE THROUGH MUCH OF
THE DAY. LESS QPF IS EXPECTED DURING THIS TIME HOWEVER.
FOR TOTAL QPF...HPC GUIDANCE IS OVERALL LEANING MORE TOWARD GFS
AMOUNTS GIVING 48 HOUR RAINFALL TOTALS OF NEAR 2.5 INCHES IN THE NORTH
TO HALF AN INCH IN THE SOUTHEAST BY 00Z TUESDAY. THE HEAVIEST OF
WHICH SHOULD OCCUR SUNDAY MORNING AND SUNDAY OVERNIGHT.
FOR TEMPS...MAV GUIDANCE SEEMS TO HAVE BEEN DOING WELL WITH PROGGED
HIGHS AND LOWS SO MADE ONLY MINOR TWEAKS. MONDAY LOOKS TO BE A BIT
WARMER THAN TUESDAY WITH HIGHS IN THE MID TO UPPER 70S NORTH AND LOW
TO MID 80S SOUTH.
03
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
MODELS CONTINUE TO HOLD A BROAD TROUGH ACROSS THE SOUTHEAST THROUGH
THE PERIOD. LOW PRESSURE DEVELOPING IN THE CENTRAL GULF SHOULD BE
INTO THE WESTERN CAROLINAS AT THE BEGINNING OF THE PERIOD...WITH
MOST OF THE RAINFALL EAST OF THE CWA. HAVE HELD ON TO LOW POPS
ACROSS THE EASTERN ZONES INTO WEDNESDAY NIGHT. SOME QUESTION AS TO
HOW MUCH MOISTURE LINGERS BEHIND THIS SYSTEM AS MODELS HOLD THE
BROAD UPPER TROUGH ACROSS THE SOUTHEAST AND REMNANTS OF THE
SURFACE FRONT DRIFT ACROSS CENTRAL OR SOUTH GEORGIA. HAVE NOT
ADDED ANY POPS TO THE LAST FEW DAYS DUE TO LOW CONFIDENCE IN THE
MODEL SOLUTION.
41
&&
HYDROLOGY...
/ISSUED 330 PM EDT SAT MAY 12 2012/
HPC 1-3 DAY QPF TOTAL ENDING 12Z TUESDAY SHOWS 2.5 TO 3.00 ACROSS
EXTREME NORTH GEORGIA AND LESSER AMOUNTS ELSEWHERE. 6 HOUR FFG
VALUES ARE AROUND 4.5 INCHES OVER THE NORTH. WITH EXPECTED
RAINFALL SPREAD OVER A COUPLE OF DAYS...THINK WE SHOULD BE ABLE
TO HANDLE THESE FORECAST AMOUNTS...BUT WILL HAVE TO WATCH FOR
LOCALIZED PROBLEMS ON THE CREEKS AND RIVERS ACROSS THE NORTH.
41
AVIATION...
18Z UPDATE...
CIGS HAVE BEEN BOUNCING BETWEEN VFR AND MVFR THIS AFTERNOON...
HOWEVER SITES SHOULD STAY AT VFR LEVELS FOR THE MOST PART. WINDS
SHOULD REMAIN SOUTHEASTERLY THROUGH THE FORECAST PERIOD AND MOST
SITES SHOULD HAVE GUSTS THIS AFTERNOON STAYING UNDER 20KTS. AFTER
21Z THIS EVENING LOCATIONS EXCEPT FOR KMCN A BIT LATER SHOULD
BEGIN TO HAVE -SHRA WITH CONTINUED CHANCES THROUGH THE PERIOD.
CIGS LOOK TO LOWER TO MVFR LEVELS WITH 0VC020 BY 03Z AND IFR WITH
0VC007 ALONG WITH VISBYS AROUND 4SM BY 10Z SUNDAY. INTRODUCED
-TSRA FOR KATL AFTER 18Z SUNDAY.
//ATL CONFIDENCE...18Z UPDATE...
HIGH.
03
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 59 73 62 79 / 50 70 60 50
ATLANTA 62 73 63 77 / 70 80 50 40
BLAIRSVILLE 57 65 59 74 / 60 80 80 50
CARTERSVILLE 63 71 63 77 / 80 80 70 40
COLUMBUS 65 79 65 81 / 70 60 50 40
GAINESVILLE 59 70 62 77 / 60 80 80 50
MACON 61 79 63 82 / 50 50 50 50
ROME 63 75 62 80 / 80 80 60 40
PEACHTREE CITY 60 75 60 78 / 70 80 50 40
VIDALIA 66 81 67 84 / 30 50 50 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER
LONG TERM....41
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1156 PM CDT FRI MAY 11 2012
.SHORT TERM /TONIGHT/...
THE COLD FRONT WAS ALONG A NEWTON TO LAMONI LINE AT 20Z THIS
AFTERNOON. VISIBLE SATELLITE IMAGERY WAS SHOWING A FEW CU DEVELOPING
NEAR THE BOUNDARY. SURFACE DEW POINTS ALONG AND AHEAD OF THE FRONT
WERE IN THE MID TO UPPER 50S. THE 19Z SPC THERMODYNAMICS FIELDS
SUGGEST MODEST INSTABILITY WITH VERY WEEK MOISTURE CONVERGENCE ALONG
THE FRONT. THROUGH THE EARLY EVENING...EXPECT THE FRONT TO SLOWLY
MOVE SOUTHEAST REACHING DAVIS COUNTY BY 7 PM. 12Z GFS/NAM AND THE
LATEST HRRR DEVELOP SHOWERS OR THUNDERSTORMS NEAR THE FRONT THIS
EVENING. THERE WILL BE ENOUGH INSTABILITY AND LIFT TO KEEP A SMALL
CONDITIONAL CHANCE OF SHOWERS AND THUNDERSTORMS IN THE FORECAST.
WEAK MID LEVEL FORCING AHEAD OF POSITIVELY TILTED 700 MB TROUGH AND
MID-LEVEL MOISTURE MAY BE ADEQUATE TO PRODUCE SCATTERED SHOWERS OVER
SOUTH CENTRAL IOWA TONIGHT ALONG WITH CLOUDINESS. PREVIOUS
TEMPERATURE FORECAST LOOKED GOOD REQUIRING ONLY MINOR ADJUSTMENTS.
.LONG TERM /SATURDAY THROUGH FRIDAY/...
RATHER QUIET PERIOD TO CONTINUE INTO THE WEEKEND AND NEXT WEEK. A
FEW ITEMS TO MENTION INCLUDING COLD FRONTAL BOUNDARY HANGING UP OVER
CENTRAL TO NORTHERN MO ON SATURDAY MAY HAVE ENOUGH ISENTROPIC LIFT
TO KEEP A FEW SHOWERS OVER FAR SOUTHERN IOWA SATURDAY AND SATURDAY
EVENING. CLOUDS WILL ALSO LINGER OVER THE SOUTH ON SATURDAY BUT
SHOULD EXIT THE REGION BY SATURDAY EVENING LEAVING SUNDAY MAINLY
SUNNY AND QUIET. MODEST FLOW REMAINS ACROSS THE NORTHERN TIER STATES
WITH A FEW WAVES TRAVELING ALONG THE US CAN BORDER. A WEAK COOL
FRONT HAS BEEN ADVERTISED TO CROSS THE REGION BY TUESDAY EVENING OR
WEDNESDAY MORNING. THIS WILL ALLOW FOR SLIGHTLY COOLER AIR TO DROP
INTO THE REGION FOR A DAY PRIOR TO THE FRONT LIFTING BACK NORTH BY
WEDNESDAY NIGHT AND THURSDAY. CLIMATOLOGY FAVORS SOME THUNDER
ACTIVITY AS THE FRONT LIFTS NORTH...BUT MODELS REMAIN RATHER DRY AS
FLOW OVER THE SOUTH HAS BEEN SHUT DOWN WITH WEAK LOW PRESSURE AND
NORTHWEST FLOW HUGGING THE GULF COAST. THUS...AM RELUCTANT TO GET
TOO EXCITED ABOUT POP IN THE REMAINDER OF THE EXTENDED PERIOD UNTIL
A STRONGER WAVE DROPS INTO THE WEST. IT APPEARS THAT THE NEXT
OPPORTUNITY FOR THAT WILL COME 24 TO 48 HOURS FOLLOWING THE CURRENT
EXTENDED FORECAST. FORECAST HIGHS WILL WARM NICELY BY THE END OF THE
EXTENDED PERIOD. WITH SW FLOW IN PLACE AND GOOD MIXING COMBINED WITH
H850 TEMPS OF 17-19C...WILL LIKELY SEE HIGHS IN THE MID TO UPPER 80S
IF THE TREND HOLDS. COORD WITH SURROUNDING OFFICES WITH LOWER 80S IN
MIND AND WILL WAIT FOR A FEW MORE CONFIRMATION RUNS PRIOR TO RAISING
TEMPS HIGHER...BUT BOTH H500 PATTERN WITH RIDGE BUILDING OVER THE
LOWER MS RIVER VALLEY AND INCREASING H850 TEMPS SUPPORT VERY WARM
AND INCREASINGLY HUMID AIRMASS NORTH INTO THE REGION. EURO THICKNESS
BY 00Z SAT 5/19 BACK TO 570-573DM WHICH IS RATHER SUMMER LIKE.
&&
.AVIATION...12/06Z
COLD FRONT HAS MOVED PAST KOTM WITH NO PRECIPITATION CURRENTLY IN
THE FORECAST AREA. PRECIP ASSOCIATED WITH SW-NE ORIENTED SIOUXLAND
UPPER SYSTEM HAS DISSIPATED AS WELL. ATTENTION WILL THEN TURN TO OK
UPPER LOW AND SCATTERED SHOWERS ACROSS KS. SHOWERS WITH THIS
SYSTEM MAY MOVE NE AND AFFECT SRN TAF SITES /KDSM/KOTM/ AT ANY TIME
THROUGH 00Z BUT CONFIDENCE IN ANY PARTICULAR LOCATION OR TIMING IS
LOW SO WILL LEAVE DRY INSTEAD OF PROLONGED VCSH MENTION. EVEN IF
PRECIP DOES DEVELOP...EXPECT CONDITIONS TO REMAIN VFR.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...JOHNSON
LONG TERM...REV
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1141 PM CDT FRI MAY 11 2012
.AVIATION...
A COLD FRONT WILL PASS SOUTHEAST OF THE AREA BY 07Z. FOLLOWING
THE FRONTAL PASSAGE BEYOND 10Z...BUT WITH LIMITED COVERAGE ISOLATED
TO SCATTERED AREAS OF LIGHT PRECIPITATION EXPECTED...WILL CONTINUE
VC WORDING FOR SHOWERS THIS MORNING INTO SATURDAY AFTERNOON AND
EVENING AND NOT INCLUDE ANY MENTION OF THUNDER...AT CID...MLI...BRL
TERMINALS. PROB30 GROUP AT BRL TERMINAL WHERE GREATEST RISK OF
SHOWERS LATE MORNING INTO MID AFTERNOON. NORTH WINDS OF 5 TO 12
KTS WILL VEER TO THE NORTHEAST SATURDAY MORNING. VFR FLIGHT RULES
TO PERSIST...WITH A BRIEF PERIOD OF MVFR CIGS POSSIBLE WITH THE
STRONGEST PRECIPITATION SATURDAY MORNING INTO AFTERNOON POSSIBLY
AT BRL TERMINAL. NICHOLS
&&
.PREV DISCUSSION... /ISSUED 312 PM CDT FRI MAY 11 2012/
SYNOPSIS...
MOISTURE STARVED SURFACE COLD FRONT CONTINUES CRAWL SLOWLY ACROSS
IA THIS AFTERNOON...REACHING FROM WEST CENTRAL WI...TROUGH MASON
CITY TO WEST OF DES MOINES...INTO FAR NW MO AT 19Z. VISIBLE
SATELLITE SHOWED MOSTLY CLEAR SKIES OVER THE FORECAST AREA WITH
SIGNIFICANT CLOUD COVER NEAR THE BOUNDARY LIMITED TO MN AND
WI...WHILE POST FRONTAL CLOUDS ASSOCIATED WITH HIGHER MOISTURE AND
MID AND UPPER LEVEL FORCING WERE WELL TO THE NW FROM NW NEB
THROUGH SE SD INTO MN. AREA RADAR MOSAIC INDICATED A BAND OF
SHOWERS WELL BEHIND THE FRONT FROM W CENTRAL MN INTO N CENTRAL
NEB. ISOLATED HIGH BASED SHOWERS WERE BEGINNING TO POP UP IN W
CENTRAL AND NW IA OVER THE PAST HOUR. TEMPERATURES WERE INTO THE
UPPER 70S TO LOWER 80S OVER THE FORECAST AREA...WHILE UPPER 60S TO
LOWER 70S WERE FOUND WEST OF THE BOUNDARY ACROSS WESTERN IA AND SW
MN.
SHORT TERM...TONIGHT AND SATURDAY...
PRIMARY CHALLENGE IS RAIN CHANCES AS THE COLD FRONT PUSHES THROUGH
THE AREA TONIGHT INTO SATURDAY. WITH GULF MOISTURE RATHER MEAGER AND
LIMITED BY A LOW MOVING ACROSS TX TODAY...SURFACE DEWPOINTS HAVE
ONLY REACHED A NARROW AXIS OF MID 50S AHEAD OF THE FRONT...AND 850
MB ANALYSIS FROM THIS MORNING WOULD SUGGEST BULK OF GULF MOISTURE TO
REMAIN CUTOFF IN THE SOUTHERN PLAINS. CLOSE INSPECTION OF THE LATEST
VISIBLE SATELLITE SHOWS THE FIRST CU OF THE DAY STARTING TO POP
ALONG THE BOUNDARY NEAR DSM...AND WILL WATCH THIS DEVELOPMENT ALONG
AND AHEAD OF THE FRONT FOR POSSIBLE SHOWERS AND THUNDERSTORMS THIS
AFTERNOON AS MUCAPES RISE TO VALUES WELL BELOW 1000 J/KG.
OTHERWISE...IT LOOKS LIKE THE BETTER FORCING FOR SHOWERS TONIGHT
WILL MORE CLOSELY TIED TO THE WEAK FORCING AND MOISTURE AROUND 700
MB ASSOCIATED WITH THE CURRENT AXIS OF POST FRONTAL SHOWERS. THIS
FEATURE FOLLOWS THE FRONT INTO THE FORECAST AREA LATER THIS EVENING
AND OVERNIGHT AND WILL KEEP CHANCE POPS IN PLACE. WILL KEEP AN
MENTION OF ISOLATED THUNDERSTORMS FOR THE EVENING FOR THE POSSIBLE
DEVELOPMENT OF CONVECTION ALONG THE ADVANCING BOUNDARY...WHICH IS
STILL SUGGESTED AS POSSIBILITY BY THE HRRR MODEL. OTHERWISE...
INCREASING CLOUD COVER WILL OFFSET THE LOW LEVEL COLD AIR ADVECTION
BEHIND THE WEAKENING COLD FRONT AND LIMIT LOWS TO AROUND 50 NORTH TO
THE MID 50S SOUTH.
SATURDAY...THE FRONT CONTINUES TO WEAKEN AND SLOW AS IT DROPS TOWARD
THE UPPER LEVEL SYSTEM MOVING THROUGH THE MID MS VALLEY. WEAK MID
LEVEL FORCING AND MOISTURE IS SHOWN POOLING NORTH OF THE BOUNDARY
THROUGH AT LEAST THE MORNING HOURS TO JUSTIFY CHANCE POPS FOR LIGHT
RAIN SHOWERS. THIS THEN SHIFTS TO THE FAR SOUTH IN THE AFTERNOON AS
SURFACE HIGH PRESSURE BUILDS OVER THE NORTHERN PLAINS INTO THE UPPER
MS VALLEY...INCREASING THE LOW LEVEL FLOW OF DRY AIR INTO THE AREA.
LINGERING MID AND HIGH LEVEL MOISTURE AND WEAK FORCING EMBEDDED IN
THE MID LEVEL CYCLONIC FLOW TO THE NORTH WILL LIKELY KEEP SKIES
MOSTLY CLOUDY AND WILL LIMIT HIGHS TO THE 60S OVER MOST OF THE
AREA. SHEETS
LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY...
MAIN FOCUS THIS FORECAST TIME RANGE IS ON PRECIPITATION CHANCES
SATURDAY NIGHT AND AGAIN WEDNESDAY THROUGH FRIDAY.
SATURDAY NIGHT AND SUNDAY THE COLD FRONT CONTINUES TO SAG SOUTH. THE
850MB BOUNDARY REMAINS IN THE AREA SATURDAY NIGHT AND A WEAK VORT
MAX WILL DROP SOUTH ACROSS THE AREA. THIS MAY PRODUCE SOME ELEVATED
SHOWERS SATURDAY NIGHT...MAINLY IN THE EVENING. MOISTURE IS A
LIMITING FACTOR SO HAVE KEPT PRECIPITATION CHANCES IN THE SLIGHT
CHANCE CATEGORY. TEMPERATURES TO BE MILD BOTH PERIODS WITH CLOUDS
TEMPERING THE COOLER AND DRIER AIR COMING IN FROM THE NORTH. MINS
SATURDAY NIGHT IN THE 40S AND LOW 50S. HIGHS SUNDAY TO BE IN THE
LOW 70S.
MONDAY AND TUESDAY A WEAK SURFACE RIDGE TO BUILD SOUTH ACROSS THE
AREA WITH WEAK WESTERLY RETURN FLOW SETTING UP FOR TUESDAY. THIS
WILL ALLOW TEMPERATURES TO RISE SO THAT ON TUESDAY WE WILL HAVE
HIGHS IN THE UPPER 70S AGAIN...POSSIBLY EVEN SOME MORE LOW 80S.
FORECAST HIGHS MAY NEED TO BE RAISED IF IT STILL APPEARS WE WILL BE
WORKING WITH VERY DRY AIR AND DEEP MIXING.
WEDNESDAY THROUGH FRIDAY THE SURFACE RIDGE SLIPS OFF TO THE
SOUTHEAST AND SOUTHWEST RETURN FLOW SETS IN IN EARNEST WITH A LONG
FETCH FROM TEXAS...AND BY FRIDAY IT APPEARS THAT THERE WILL BE
STREAM OF GULF MOISTURE HEADING OUR DIRECTION. A FAIRLY STRONG
UPPER LEVEL SYSTEM OVER CANADA WILL PUSH A COLD FRONT TOWARDS THE
AREA WEDNESDAY. THIS FRONT MAY DROP INTO THE AREA WEDNESDAY...
THOUGH THERE IS SOME MODEL DISAGREEMENT HERE...WITH SOME KEEPING IT
NORTH OF THE AREA. FOR NOW HAVE KEPT THE FORECAST DRY AS THERE IS
LITTLE MOISTURE AVAILABLE FOR THIS BOUNDARY TO WORK WITH. A SURFACE
LOW IS GENERATED OVER WESTERN KANSAS...AND BY THURSDAY AND FRIDAY
THE FRONT BECOMES A WARM FRONT AND PUSHES BACK NORTH...AND WILL BE
GENERALLY DRAPED FROM SOUTH DAKOTA ACROSS SOUTHERN MINNESOTA AND
INTO WISCONSIN. UNLESS THIS CHANGES THIS IS LIKELY TO BE THE STORM
TRACK NEXT WEEK...AND WE WILL BE SITTING IN A VERY WARM AND
INCREASINGLY HUMID AIRMASS BOTH DAYS...WITH HIGHS INTO THE LOW 80S.
HAVE SOME VERY LOW END CHANCE POPS IN THE FORECAST...BUT UNLESS THE
FRONT SHIFTS CLOSER TO THE AREA AM ANTICIPATING WE WILL BE DRY.
LE
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
NICHOLS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
843 PM MDT SUN MAY 13 2012
.UPDATE...
ISSUED AT 837 PM MDT SUN MAY 13 2012
JUST ISSUED ANOTHER UPDATE. CURRENT PRECIPITATION FORECAST IS
TRENDING AND MADE NO CHANGES. THERE WAS LITTLE WIND/MIXING THROUGH
THE DAY WITH DEWPOINTS NEARLY THE SAME TODAY AS YESTERDAY. AREA
SOUNDINGS SHOW THAT THE LOW LEVEL MOISTURE HAS ALSO CHANGED LITTLE
ALTHOUGH THE AIR MASS HAS WARMED. WITH A SIMILAR AIR MASS
YESTERDAY THERE WAS SOME MORNING FOG. ALSO CLUSTER OF
THUNDERSTORMS DROPPED A DECENT AMOUNT OF RAINFALL OVER A RATHER
LARGE AREA OVER WESTERN KIT CARSON AND CHEYENNE COUNTIES.
WINDS WILL BE LIGHT AND THEN WILL SHIFT TO THE WEST TO BRING THIS
MOISTURE IN FROM THE WEST. CONSIDERING THE RUC THAT HAS A GOOD
HANDLE ON THE WIND FIELD...DRIER AIR WORKS ITS WAY INTO THE
NORTHEAST HALF OF THE AREA. RUC AND TO A LESSER DEGREE THE ECMWF
INCREASE LOW LEVEL MOISTURE OVER THE SOUTHWEST HALF ALTHOUGH THE
RUC WOULD SAY IT WILL BE STRATUS. AS A RESULT...ADDED PATCHY TO
AREAS OF FOG FOR LATER TONIGHT INTO TOMORROW MORNING. LATEST MAV
WAS DOING WELL WITH THE DEWPOINTS AND AS STATED ABOVE USED THE RUC
FOR THE WINDS AND BLENDED THEM WITH REALITY. OVERNIGHT LOWS LOOK
FINE AT THIS TIME.
UPDATE ISSUED AT 623 PM MDT SUN MAY 13 2012
PERSISTENT AND SLOW MOVING CLUSTER OF STORMS LOCATED OVER/NEAR WESTERN
KIT CARSON AT THIS TIME. THIS AREA LOOKS TO BE IN AN AREA OF
SURFACE/MOISTURE CONVERGENCE COMBINED WITH WEAK SHORTWAVE TROUGH
AND DEEPEST MOISTURE. RAISED POPS MUCH HIGHER OUT WEST...EXPANDED
AREA OF THUNDERSTORMS AND PER CONVERGENCE AND QPF FORECASTS...EXTENDED
THUNDERSTORMS UNTIL 06Z. ALSO INCREASED CLOUD COVER OVER THE WEST
AND SOUTHWEST PORTIONS OF THE AREA WHERE CONVECTION IS OCCURRING.
OTHERWISE JUST MADE MINOR ADJUSTMENTS WITH THE REMAINING ELEMENTS.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH MONDAY EVENING)
ISSUED AT 1157 AM MDT SUN MAY 13 2012
SCATTERED TO BROKEN SKY COVER THIS AFTERNOON WILL PERSIST WITH THE
DAYTIME HEATING PRODUCING A WIDESPREAD CU FIELD. EXPECT THIS TO
DISSIPATE RAPIDLY FOLLOWING SUNSET WITH DRYER AIR MOVING IN MONDAY
AND MONDAY NIGHT AS THE RIDGE OF HIGHER PRESSURE MOVES OVER THE
ROCKIES AND HIGH PLAINS REGION. THERE IS SOME CONVECTIVE ACTIVITY
DEVELOPING OVER THE HIGH TERRAIN OF COLORADO THIS AFTERNOON...SO
THERE IS THE POSSIBILITY OF A FEW SHOWERS MAKING THEIR WAY OVER
THE FAR SOUTHWESTERN PORTION OF THE FORECAST AREA LATE THIS
AFTERNOON AND EARLY EVENING. ANY SHOWERS THAT DO MAKE IT THIS FAR
EAST SHOULD DISSIPATE RAPIDLY AFTER 03Z.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 236 PM MDT SUN MAY 13 2012
TUESDAY-TUESDAY NIGHT...SHORTWAVE RIDGE WILL REMAIN IN PLACE THROUGH
TUESDAY NIGHT...WITH LARGE SCALE SUBSIDENCE SUPPORTING DRY
CONDITIONS. MUCH WARMER TEMPERATURES ARE EXPECTED WITH GUIDANCE
CONTINUING TO SUPPORT TEMPS IN THE MID TO UPPER 80S OVER MUCH OF THE
CWA...WITH TEMPS AROUND 90F IN THE EAST.
WEDNESDAY-THURSDAY NIGHT...VERY WARM TEMPERATURES CONTINUE WITH
SOUTHERLY FLOW IN PLACE AND H85 TEMPS AROUND 25C. HIGHS ON WEDNESDAY
AND THURSDAY WILL BE VERY SIMILAR TO TUESDAY...WITH HIGHS OVER MUCH
OF THE CWA IN THE UPPER 80S. H5 RIDGE BEGINS TO BREAK DOWN WEDNESDAY
AS A SHORTWAVE TROUGH MOVES TOWARDS THE INTER-MOUNTAIN WEST/HIGH
PLAINS. STILL SOME RUN-RUN SPREAD BETWEEN GUIDANCE ON
TIMING/POSITION OF THIS FEATURE...WITH 12Z ECMWF SLOWER AND DRIER.
GFS AND NAM STILL SUPPORT TIMING/COVERAGE FROM PREVIOUS FORECAST
WITH THUNDERSTORMS BEGINNING IN EASTERN COLORADO WEDNESDAY AFTERNOON
AND SPREADING EAST ACROSS THE CWA THROUGH THURSDAY. COVERAGE IS
STILL A QUESTION EVEN WITH THE GFS/NAM SOLUTIONS...WITH LIMITED
MOISTURE ADVECTION AND INSTABILITY WEDNESDAY/WEDNESDAY NIGHT. I
KEPT POPS LIMITED TO SLIGHT CHANCE CATEGORY...AND MADE ONLY MINOR
ADJUSTMENTS TO LOCATION OF POPS IN CWA. IF GFS/NAM IS CORRECT THEN
BEST CHANCE FOR PRECIP WITH THIS FEATURE MAY END UP BEING THURSDAY
OVER OUR EASTERN CWA.
FRIDAY-SUNDAY...SUBSIDENCE ASSOCIATED WITH SHORTWAVE RIDGE SHOULD
KEEP FRIDAY WARM AND DRY. PRECIP CHANCES RETURN BY SATURDAY AS SW
FLOW SET UP ACROSS CWA...AND COLD FRONT DROPS SOUTH ACROSS CWA
SUNDAY. THERE IS STILL CONSIDERABLE SPREAD IN UPPER LEVEL PATTERN
BETWEEN OPERATIONAL GUIDANCE...HOWEVER BOTH GFS AND ECMWF SUPPORT
PRECIP CHANCES SATURDAY THROUGH SUNDAY NIGHT. I CONSIDERED RAISING
POPS...HOWEVER WITH SPREAD ON UPPER LEVEL AND SURFACE FEATURES...ITS
DIFFICULT TO PIN DOWN FAVORED LOCATIONS AT THIS TIME. RATHER THAN
STRAY TOO FAR FROM PREVIOUS TRENDS...I KEPT POPS IN SLIGHT
CHANCE/CHANCE CATEGORIES DURING THESE PERIODS TO ACCOUNT FOR MODEL
SPREAD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 540 PM MDT SUN MAY 13 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. SMALL CLUSTER OF
THUNDERSTORMS OVER EAST CENTRAL COLORADO. AT THIS TIME...THIS AREA
SHOULD STAY TO THE WEST OF KGLD. OTHERWISE LIGHT AND VARIABLE
WINDS EXPECTED THROUGH THE WHOLE PERIOD.
&&
.FIRE WEATHER...
ISSUED AT 236 PM MDT SUN MAY 13 2012
RED FLAG CONDITIONS WILL BE POSSIBLE WEDNESDAY THROUGH FRIDAY WITH
RH VALUES AND WINDS APPROACHING CRITERIA. BEST CHANCE FOR RED FLAG
CRITERIA TO BE MET LOOKS TO BE ON WEDNESDAY AFTERNOON WHEN WINDS
GUSTING OVER 25 MPH WILL BE COMMON ACROSS THE CWA. THERE ARE STILL
QUESTIONS ON HOW LOW RH VALUES WILL BE WEDNESDAY WITH SHORTWAVE
TROUGH MOVING IN FROM THE WEST. IF PROFILES REMAIN DRY ADIABATIC
THROUGH THE AFTERNOON...CURRENT TD/RH FORECAST COULD BE TOO HIGH.
THIS WILL NEED TO BE MONITORED.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...LOCKHART
LONG TERM...DR
AVIATION...BULLER
FIRE WEATHER...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
929 AM MDT SAT MAY 12 2012
.UPDATE...
ISSUED AT 928 AM MDT SAT MAY 12 2012
AM UPDATING FORECAST TO BETTE DEPICT THE AREA OF LIGHT RAIN WITH
A FEW EMBEDDED STRONGER SHOWERS MOVING ACROSS THE FORECAST AREA
THIS MORNING.
UPDATE ISSUED AT 551 AM MDT SAT MAY 12 2012
AREA OF LIGHT RAIN SHOWERS BECOMING FAIRLY WELL ORGANIZED AHEAD OF
SHORT WAVE TROUGH ACROSS THE NORTHERN PART OF CWA...WITH
MEASURABLE PRECIPITATION BEING OBSERVED WITH WEAKER ECHOES
CONFIDENCE HAS INCREASED IN COVERAGE OF MEASURABLE PRECIP. WHILE
THINK GENERAL TIMING OF FORECAST REMAINS OK...DID INCREASE
MAGNITUDE OF POPS 20-30 PERCENT MAINLY ACROSS NORTHERN CWA TO
ACCOUNT FOR CURRENT ACTIVITY. RADAR ECHOES BECOMING BETTER
ORGANIZED TO THE SOUTH AS WELL...BUT SO FAR HAVE NOT SEEN MUCH IN
THE WAY OF -RA IN OBS SO WILL CONTINUE WITH SCATTERED POPS IN THIS
AREA.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 259 AM MDT SAT MAY 12 2012
230Z WATER VAPOR IMAGERY AND RUC ANALYSIS INDICATED CLOSE LOW
CIRCULATION ACROSS THE SOUTHERN PLAINS WITH LARGE TROUGH ACROSS THE
NORTHERN PLAINS WITH AN EMBEDDED SHORT WAVE TROUGH MOVING INTO
WESTERN COLORADO. AT THE SURFACE 1028MB SFC HIGH WAS BUILDING OVER
THE AREA BEHIND FRONTAL ZONE WHICH WAS DRAPED FROM SOUTHEAST
COLORADO INTO NW MISSOURI. 00Z RAOBS...ESPECIALLY AT KLBF AND KDNR
INDICATED A FAIRLY DEEP FRONT IN PLACE WITH FRONTAL INVERSION ENDING
AROUND 725 MB AND 675MB RESPECTIVELY. ALTHOUGH FAIRLY DRY AIR WAS
LOCATED BELOW INVERSION AT LBF...PARCELS LIFTED FROM TOP OF
INVERSION DID INDICATE SOME VERY WEAK CAPE PRESENT.
PRECIP CHANCES THIS MORNING THROUGH THE REST OF THE WEEKEND WILL BE
PRIMARY NEAR TERM CONCERNS.
TODAY...ONGOING LIGHT PRECIPITATION WILL BE PRIMARY FORECAST
CHALLENGE THIS MORNING AND WITH TEMPERATURES DROPPING INTO THE 30S
AND WBZ HEIGHTS FALLING TO AROUND 1500FT WOULD NOT RULE OUT A FEW
SNOW FLAKES MIXING IN WITH THE PRECIPITATION IN WESTERN CWA THIS
MORNING...BUT IF IT DOES OCCUR DO NOT THINK IT WILL AMOUNT TO MUCH
WITH SOIL TEMPS WELL ABOVE FREEZING. AREA OF LIGHT PRECIPITATION
WILL GRADUALLY SHIFT TO THE EAST THIS MORNING IN AREA OF WEAK
ISENTROPIC ASCENT AND H7 FRONTOGENESIS. INITIALLY THOUGHT THIS WOULD
BE THE ONLY AREA OF PRECIPITATION...BUT LOOKING UPSTREAM STARTING TO
SEE REDEVELOPMENT OF PRECIPITATION IN AREA THAT LOOKS TO BE DIRECTLY
AHEAD OF WEAK SHORT WAVE TROUGH AS PER WV IMAGERY AND RUC PV
ANALYSIS. TIMING THIS FEATURE PUTS IT OVER NORTHERN CWA BY
15Z...WHICH IS CONSISTENT WITH TIMING OF PRECIP AMONGST VARIOUS
MODELS AND SREF DATA AND HAVE MODIFIED FORECAST TO ACCOUNT FOR THIS
TIMING. THINK PRECIP THREAT WILL END FAIRLY QUICKLY AS THIS TROUGH
PASSES AND THINK WE WILL SEE A PERIOD OF NO PRECIPITATION ACROSS THE
CWA AROUND 21Z. FOR ACTUAL PROBABILITY VALUES...GIVEN A LARGE DEGREE
OF SPREAD IN ACTUAL PLACEMENT OF PRECIP MAXIMA AND SURPRISINGLY LOW
PROBABILITIES OF 0.05 OR GREATER FROM THE GEFS DATA AM A LITTLE
HESITANT TO GO TOO HIGH ON POPS...BUT THINK A GENERAL 30-50% CHANCE
IS WARRANTED FOR A GOOD PORTION OF THE AREA. THE ACTUAL MAGNITUDE OF
POPS WILL DEPEND STRONGLY ON BEHAVIOR OF UPSTREAM PRECIP OVER THE
NEXT FEW HOURS.
TONIGHT-SUNDAY...BRIEF PERIOD OF SUBSIDENCE WILL OVERSPREAD THE AREA
AT THE START OF THE PERIOD AS INITIAL SHORT WAVE TROUGH MOVES TO THE
EAST OF THE AREA....BEFORE NEXT TROUGH BEGINS TO DIVE INTO COLORADO
THROUGH THE OVERNIGHT HOURS. SUBSIDENCE DOES NOT LOOK ALL THAT
STRONG AT THIS POINT BUT DEFINITELY THINK LOWEST CHANCES FOR RAIN WILL
BE IN THE EARLY EVENING. MODELS HAVE HAD A BIT OF DIFFICULTY WITH
THE HANDLING OF THIS SYSTEM...JUMPING FROM VERY WET TO DRY SOLUTIONS
OVER THE PAST SEVERAL RUNS SO OVERALL CONFIDENCE IS NOT THAT HIGH.
LARGE SCALE FORCING FOR ASCENT WILL INCREASE THROUGH THE NIGHT WITH
STRONGEST VALUES BETWEEN 9Z AND 18Z SUNDAY...WITH SYNOPTIC SCALE
FORCING MAXIMIZED OVER COLORADO AND CWA REALLY ON THE FRINGE OF
STRONGEST FORCED ASCENT. APPEARS TO BE A WINDOW WITH STRONG H7 TO H5
FRONTOGENESIS DEVELOPING ACROSS THE SOUTHWESTERN CWA...BUT HAVE SOME
CONCERNS THAT A LOT OF THIS FORCING IS SOMEWHAT DUE TO CONVECTIVE
FEEDBACK ESPECIALLY ON THE GFS WHICH SEEMS TO DEVELOP SMALL LOW
CIRCULATION OVERNIGHT SATURDAY WHICH MAXIMIZES FORCING. VERY HIGH
QPF FIELDS IN SPITE OF MINIMAL INSTABILITY ALSO MAKE ME THINK THAT
THERE IS SOME FEEDBACK ISSUES AT PLAY WITH THE BULLS EYE OF ASCENT.
WITH THAT IN MIND...DO NOT WANT TO RAMP UP POPS/QPFS AT THIS TIME
DUE TO LOW CONFIDENCE IN THE PREDICTABILITY OF THESE FEATURES...BUT
FEEL 30-50% POPS WARRANTED FOR THE TIME BEING. WITH VERY LITTLE IF
ANY ELEVATED CAPE HAVE DECIDED TO KEEP WX GROUPS AS JUST RAIN.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 259 AM MDT SAT MAY 12 2012
SUNDAY NIGHT-MONDAY NIGHT...QUIETER WEATHER EXPECTED THROUGH THE
PERIOD AS MAJORITY OF OPERATIONAL DATA SUGGEST SHORT WAVE RIDGING
BUILDING OVER THE THE AREA THROUGH THE REST OF THE PERIOD BEHIND
DEPARTING TROUGH WITH SUBSIDENCE/DRYING QUICKLY BRINGING AN END TO
ANY PRECIP THREAT ACROSS THE AREA. MAIN FOCUS WILL BE HOW QUICKLY
TEMPERATURES RECOVER THROUGH THE PERIOD. GENERAL WARMING TREND LOOKS
TO BE IN ORDER...BUT GIVEN SOME MUCH COLDER DATA IN SREF PLUMES AM A
LITTLE HESITANT TO WARM THINGS TOO MUCH AT THIS POINT.
THE REGION WILL BE UNDER THE EASTERN PORTION OF AN UPPER LEVEL RIDGE
OF HIGH PRESSURE AT THE BEGINNING OF THE PERIOD...WITH DRY
CONDITIONS EXPECTED THROUGH DAYTIME WEDNESDAY. A SHORTWAVE TROUGH
WILL APPROACH THE REGION ON WEDNESDAY NIGHT AND MOVE OVER THE REGION
DURING THE DAYTIME ON THURSDAY. GIVEN THE INSTABILITY EXPECTED
DURING THIS PERIOD...HAVE INCLUDED MENTION OF THUNDERSTORMS WITH THE
SLIGHT CHANCE OF PRECIPITATION...THOUGH CONVECTIVE INHIBITION IS
STILL FAIRLY STRONG OVER MUCH OF THE AREA DURING THIS TIME. THE
UPPER LEVEL FLOW WILL BEGIN TO BECOME MORE ZONAL BY THE END OF THE
PERIOD AS THE UPPER RIDGE MOVES EASTWARD...AND ANOTHER SHORTWAVE
TROUGH BEGINS TO APPROACH THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 551 AM MDT SAT MAY 12 2012
AREA OF PRECIPITATION DEVELOPING AHEAD OF SHORT WAVE TROUGH WILL
BE PRIMARY CONCERN AT BOTH TERMINALS WITH LIGHT RAIN ALREADY
OCCURRING AT GLD AND MCK AND WILL LIKELY PERSIST THROUGH 17Z AT GLD
AND 20Z AT MCK. MAY SEE A PERIOD OF NEAR MVFR CIGS THROUGH THE
MORNING HOURS...BUT BASED OFF OF CURRENT TRENDS DO NOT THINK CIGS
WILL GET MUCH LOWER THAN 3000 FT AT THIS TIME.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...LOCKHART
SHORT TERM...JRM
LONG TERM...JRM/CJS
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
605 AM MDT SAT MAY 12 2012
.UPDATE...
ISSUED AT 551 AM MDT SAT MAY 12 2012
AREA OF LIGHT RAIN SHOWERS BECOMING FAIRLY WELL ORGANIZED AHEAD OF
SHORT WAVE TROUGH ACROSS THE NORTHERN PART OF CWA...WITH
MEASURABLE PRECIPITATION BEING OBSERVED WITH WEAKER ECHOES
CONFIDENCE HAS INCREASED IN COVERAGE OF MEASURABLE PRECIP. WHILE
THINK GENERAL TIMING OF FORECAST REMAINS OK...DID INCREASE
MAGNITUDE OF POPS 20-30 PERCENT MAINLY ACROSS NORTHERN CWA TO
ACCOUNT FOR CURRENT ACTIVITY. RADAR ECHOES BECOMING BETTER
ORGANIZED TO THE SOUTH AS WELL...BUT SO FAR HAVE NOT SEEN MUCH IN
THE WAY OF -RA IN OBS SO WILL CONTINUE WITH SCATTERED POPS IN THIS
AREA.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 259 AM MDT SAT MAY 12 2012
230Z WATER VAPOR IMAGERY AND RUC ANALYSIS INDICATED CLOSE LOW
CIRCULATION ACROSS THE SOUTHERN PLAINS WITH LARGE TROUGH ACROSS THE
NORTHERN PLAINS WITH AN EMBEDDED SHORT WAVE TROUGH MOVING INTO
WESTERN COLORADO. AT THE SURFACE 1028MB SFC HIGH WAS BUILDING OVER
THE AREA BEHIND FRONTAL ZONE WHICH WAS DRAPED FROM SOUTHEAST
COLORADO INTO NW MISSOURI. 00Z RAOBS...ESPECIALLY AT KLBF AND KDNR
INDICATED A FAIRLY DEEP FRONT IN PLACE WITH FRONTAL INVERSION ENDING
AROUND 725 MB AND 675MB RESPECTIVELY. ALTHOUGH FAIRLY DRY AIR WAS
LOCATED BELOW INVERSION AT LBF...PARCELS LIFTED FROM TOP OF
INVERSION DID INDICATE SOME VERY WEAK CAPE PRESENT.
PRECIP CHANCES THIS MORNING THROUGH THE REST OF THE WEEKEND WILL BE
PRIMARY NEAR TERM CONCERNS.
TODAY...ONGOING LIGHT PRECIPITATION WILL BE PRIMARY FORECAST
CHALLENGE THIS MORNING AND WITH TEMPERATURES DROPPING INTO THE 30S
AND WBZ HEIGHTS FALLING TO AROUND 1500FT WOULD NOT RULE OUT A FEW
SNOW FLAKES MIXING IN WITH THE PRECIPITATION IN WESTERN CWA THIS
MORNING...BUT IF IT DOES OCCUR DO NOT THINK IT WILL AMOUNT TO MUCH
WITH SOIL TEMPS WELL ABOVE FREEZING. AREA OF LIGHT PRECIPITATION
WILL GRADUALLY SHIFT TO THE EAST THIS MORNING IN AREA OF WEAK
ISENTROPIC ASCENT AND H7 FRONTOGENESIS. INITIALLY THOUGHT THIS WOULD
BE THE ONLY AREA OF PRECIPITATION...BUT LOOKING UPSTREAM STARTING TO
SEE REDEVELOPMENT OF PRECIPITATION IN AREA THAT LOOKS TO BE DIRECTLY
AHEAD OF WEAK SHORT WAVE TROUGH AS PER WV IMAGERY AND RUC PV
ANALYSIS. TIMING THIS FEATURE PUTS IT OVER NORTHERN CWA BY
15Z...WHICH IS CONSISTENT WITH TIMING OF PRECIP AMONGST VARIOUS
MODELS AND SREF DATA AND HAVE MODIFIED FORECAST TO ACCOUNT FOR THIS
TIMING. THINK PRECIP THREAT WILL END FAIRLY QUICKLY AS THIS TROUGH
PASSES AND THINK WE WILL SEE A PERIOD OF NO PRECIPITATION ACROSS THE
CWA AROUND 21Z. FOR ACTUAL PROBABILITY VALUES...GIVEN A LARGE DEGREE
OF SPREAD IN ACTUAL PLACEMENT OF PRECIP MAXIMA AND SURPRISINGLY LOW
PROBABILITIES OF 0.05 OR GREATER FROM THE GEFS DATA AM A LITTLE
HESITANT TO GO TOO HIGH ON POPS...BUT THINK A GENERAL 30-50% CHANCE
IS WARRANTED FOR A GOOD PORTION OF THE AREA. THE ACTUAL MAGNITUDE OF
POPS WILL DEPEND STRONGLY ON BEHAVIOR OF UPSTREAM PRECIP OVER THE
NEXT FEW HOURS.
TONIGHT-SUNDAY...BRIEF PERIOD OF SUBSIDENCE WILL OVERSPREAD THE AREA
AT THE START OF THE PERIOD AS INITIAL SHORT WAVE TROUGH MOVES TO THE
EAST OF THE AREA....BEFORE NEXT TROUGH BEGINS TO DIVE INTO COLORADO
THROUGH THE OVERNIGHT HOURS. SUBSIDENCE DOES NOT LOOK ALL THAT
STRONG AT THIS POINT BUT DEFINITELY THINK LOWEST CHANCES FOR RAIN WILL
BE IN THE EARLY EVENING. MODELS HAVE HAD A BIT OF DIFFICULTY WITH
THE HANDLING OF THIS SYSTEM...JUMPING FROM VERY WET TO DRY SOLUTIONS
OVER THE PAST SEVERAL RUNS SO OVERALL CONFIDENCE IS NOT THAT HIGH.
LARGE SCALE FORCING FOR ASCENT WILL INCREASE THROUGH THE NIGHT WITH
STRONGEST VALUES BETWEEN 9Z AND 18Z SUNDAY...WITH SYNOPTIC SCALE
FORCING MAXIMIZED OVER COLORADO AND CWA REALLY ON THE FRINGE OF
STRONGEST FORCED ASCENT. APPEARS TO BE A WINDOW WITH STRONG H7 TO H5
FRONTOGENESIS DEVELOPING ACROSS THE SOUTHWESTERN CWA...BUT HAVE SOME
CONCERNS THAT A LOT OF THIS FORCING IS SOMEWHAT DUE TO CONVECTIVE
FEEDBACK ESPECIALLY ON THE GFS WHICH SEEMS TO DEVELOP SMALL LOW
CIRCULATION OVERNIGHT SATURDAY WHICH MAXIMIZES FORCING. VERY HIGH
QPF FIELDS IN SPITE OF MINIMAL INSTABILITY ALSO MAKE ME THINK THAT
THERE IS SOME FEEDBACK ISSUES AT PLAY WITH THE BULLS EYE OF ASCENT.
WITH THAT IN MIND...DO NOT WANT TO RAMP UP POPS/QPFS AT THIS TIME
DUE TO LOW CONFIDENCE IN THE PREDICTABILITY OF THESE FEATURES...BUT
FEEL 30-50% POPS WARRANTED FOR THE TIME BEING. WITH VERY LITTLE IF
ANY ELEVATED CAPE HAVE DECIDED TO KEEP WX GROUPS AS JUST RAIN.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 259 AM MDT SAT MAY 12 2012
SUNDAY NIGHT-MONDAY NIGHT...QUIETER WEATHER EXPECTED THROUGH THE
PERIOD AS MAJORITY OF OPERATIONAL DATA SUGGEST SHORT WAVE RIDGING
BUILDING OVER THE THE AREA THROUGH THE REST OF THE PERIOD BEHIND
DEPARTING TROUGH WITH SUBSIDENCE/DRYING QUICKLY BRINGING AN END TO
ANY PRECIP THREAT ACROSS THE AREA. MAIN FOCUS WILL BE HOW QUICKLY
TEMPERATURES RECOVER THROUGH THE PERIOD. GENERAL WARMING TREND LOOKS
TO BE IN ORDER...BUT GIVEN SOME MUCH COLDER DATA IN SREF PLUMES AM A
LITTLE HESITANT TO WARM THINGS TOO MUCH AT THIS POINT.
THE REGION WILL BE UNDER THE EASTERN PORTION OF AN UPPER LEVEL RIDGE
OF HIGH PRESSURE AT THE BEGINNING OF THE PERIOD...WITH DRY
CONDITIONS EXPECTED THROUGH DAYTIME WEDNESDAY. A SHORTWAVE TROUGH
WILL APPROACH THE REGION ON WEDNESDAY NIGHT AND MOVE OVER THE REGION
DURING THE DAYTIME ON THURSDAY. GIVEN THE INSTABILITY EXPECTED
DURING THIS PERIOD...HAVE INCLUDED MENTION OF THUNDERSTORMS WITH THE
SLIGHT CHANCE OF PRECIPITATION...THOUGH CONVECTIVE INHIBITION IS
STILL FAIRLY STRONG OVER MUCH OF THE AREA DURING THIS TIME. THE
UPPER LEVEL FLOW WILL BEGIN TO BECOME MORE ZONAL BY THE END OF THE
PERIOD AS THE UPPER RIDGE MOVES EASTWARD...AND ANOTHER SHORTWAVE
TROUGH BEGINS TO APPROACH THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 551 AM MDT SAT MAY 12 2012
AREA OF PRECIPITATION DEVELOPING AHEAD OF SHORT WAVE TROUGH WILL
BE PRIMARY CONCERN AT BOTH TERMINALS WITH LIGHT RAIN ALREADY
OCCURRING AT GLD AND MCK AND WILL LIKELY PERSIST THROUGH 17Z AT GLD
AND 20Z AT MCK. MAY SEE A PERIOD OF NEAR MVFR CIGS THROUGH THE
MORNING HOURS...BUT BASED OFF OF CURRENT TRENDS DO NOT THINK CIGS
WILL GET MUCH LOWER THAN 3000 FT AT THIS TIME.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...JRM
LONG TERM...JRM/CJS
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
302 AM MDT SAT MAY 12 2012
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 259 AM MDT SAT MAY 12 2012
230Z WATER VAPOR IMAGERY AND RUC ANALYSIS INDICATED CLOSE LOW
CIRCULATION ACROSS THE SOUTHERN PLAINS WITH LARGE TROUGH ACROSS THE
NORTHERN PLAINS WITH AN EMBEDDED SHORT WAVE TROUGH MOVING INTO
WESTERN COLORADO. AT THE SURFACE 1028MB SFC HIGH WAS BUILDING OVER
THE AREA BEHIND FRONTAL ZONE WHICH WAS DRAPED FROM SOUTHEAST
COLORADO INTO NW MISSOURI. 00Z RAOBS...ESPECIALLY AT KLBF AND KDNR
INDICATED A FAIRLY DEEP FRONT IN PLACE WITH FRONTAL INVERSION ENDING
AROUND 725 MB AND 675MB RESPECTIVELY. ALTHOUGH FAIRLY DRY AIR WAS
LOCATED BELOW INVERSION AT LBF...PARCELS LIFTED FROM TOP OF
INVERSION DID INDICATE SOME VERY WEAK CAPE PRESENT.
PRECIP CHANCES THIS MORNING THROUGH THE REST OF THE WEEKEND WILL BE
PRIMARY NEAR TERM CONCERNS.
TODAY...ONGOING LIGHT PRECIPITATION WILL BE PRIMARY FORECAST
CHALLENGE THIS MORNING AND WITH TEMPERATURES DROPPING INTO THE 30S
AND WBZ HEIGHTS FALLING TO AROUND 1500FT WOULD NOT RULE OUT A FEW
SNOW FLAKES MIXING IN WITH THE PRECIPITATION IN WESTERN CWA THIS
MORNING...BUT IF IT DOES OCCUR DO NOT THINK IT WILL AMOUNT TO MUCH
WITH SOIL TEMPS WELL ABOVE FREEZING. AREA OF LIGHT PRECIPITATION
WILL GRADUALLY SHIFT TO THE EAST THIS MORNING IN AREA OF WEAK
ISENTROPIC ASCENT AND H7 FRONTOGENESIS. INITIALLY THOUGHT THIS WOULD
BE THE ONLY AREA OF PRECIPITATION...BUT LOOKING UPSTREAM STARTING TO
SEE REDEVELOPMENT OF PRECIPITATION IN AREA THAT LOOKS TO BE DIRECTLY
AHEAD OF WEAK SHORT WAVE TROUGH AS PER WV IMAGERY AND RUC PV
ANALYSIS. TIMING THIS FEATURE PUTS IT OVER NORTHERN CWA BY
15Z...WHICH IS CONSISTENT WITH TIMING OF PRECIP AMONGST VARIOUS
MODELS AND SREF DATA AND HAVE MODIFIED FORECAST TO ACCOUNT FOR THIS
TIMING. THINK PRECIP THREAT WILL END FAIRLY QUICKLY AS THIS TROUGH
PASSES AND THINK WE WILL SEE A PERIOD OF NO PRECIPITATION ACROSS THE
CWA AROUND 21Z. FOR ACTUAL PROBABILITY VALUES...GIVEN A LARGE DEGREE
OF SPREAD IN ACTUAL PLACEMENT OF PRECIP MAXIMA AND SURPRISINGLY LOW
PROBABILITIES OF 0.05 OR GREATER FROM THE GEFS DATA AM A LITTLE
HESITANT TO GO TOO HIGH ON POPS...BUT THINK A GENERAL 30-50% CHANCE
IS WARRANTED FOR A GOOD PORTION OF THE AREA. THE ACTUAL MAGNITUDE OF
POPS WILL DEPEND STRONGLY ON BEHAVIOR OF UPSTREAM PRECIP OVER THE
NEXT FEW HOURS.
TONIGHT-SUNDAY...BRIEF PERIOD OF SUBSIDENCE WILL OVERSPREAD THE AREA
AT THE START OF THE PERIOD AS INITIAL SHORT WAVE TROUGH MOVES TO THE
EAST OF THE AREA....BEFORE NEXT TROUGH BEGINS TO DIVE INTO COLORADO
THROUGH THE OVERNIGHT HOURS. SUBSIDENCE DOES NOT LOOK ALL THAT
STRONG AT THIS POINT BUT DEFINITELY THINK LOWEST CHANCES FOR RAIN WILL
BE IN THE EARLY EVENING. MODELS HAVE HAD A BIT OF DIFFICULTY WITH
THE HANDLING OF THIS SYSTEM...JUMPING FROM VERY WET TO DRY SOLUTIONS
OVER THE PAST SEVERAL RUNS SO OVERALL CONFIDENCE IS NOT THAT HIGH.
LARGE SCALE FORCING FOR ASCENT WILL INCREASE THROUGH THE NIGHT WITH
STRONGEST VALUES BETWEEN 9Z AND 18Z SUNDAY...WITH SYNOPTIC SCALE
FORCING MAXIMIZED OVER COLORADO AND CWA REALLY ON THE FRINGE OF
STRONGEST FORCED ASCENT. APPEARS TO BE A WINDOW WITH STRONG H7 TO H5
FRONTOGENESIS DEVELOPING ACROSS THE SOUTHWESTERN CWA...BUT HAVE SOME
CONCERNS THAT A LOT OF THIS FORCING IS SOMEWHAT DUE TO CONVECTIVE
FEEDBACK ESPECIALLY ON THE GFS WHICH SEEMS TO DEVELOP SMALL LOW
CIRCULATION OVERNIGHT SATURDAY WHICH MAXIMIZES FORCING. VERY HIGH
QPF FIELDS IN SPITE OF MINIMAL INSTABILITY ALSO MAKE ME THINK THAT
THERE IS SOME FEEDBACK ISSUES AT PLAY WITH THE BULLS EYE OF ASCENT.
WITH THAT IN MIND...DO NOT WANT TO RAMP UP POPS/QPFS AT THIS TIME
DUE TO LOW CONFIDENCE IN THE PREDICTABILITY OF THESE FEATURES...BUT
FEEL 30-50% POPS WARRANTED FOR THE TIME BEING. WITH VERY LITTLE IF
ANY ELEVATED CAPE HAVE DECIDED TO KEEP WX GROUPS AS JUST RAIN.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 259 AM MDT SAT MAY 12 2012
SUNDAY NIGHT-MONDAY NIGHT...QUIETER WEATHER EXPECTED THROUGH THE
PERIOD AS MAJORITY OF OPERATIONAL DATA SUGGEST SHORT WAVE RIDGING
BUILDING OVER THE THE AREA THROUGH THE REST OF THE PERIOD BEHIND
DEPARTING TROUGH WITH SUBSIDENCE/DRYING QUICKLY BRINGING AN END TO
ANY PRECIP THREAT ACROSS THE AREA. MAIN FOCUS WILL BE HOW QUICKLY
TEMPERATURES RECOVER THROUGH THE PERIOD. GENERAL WARMING TREND LOOKS
TO BE IN ORDER...BUT GIVEN SOME MUCH COLDER DATA IN SREF PLUMES AM A
LITTLE HESITANT TO WARM THINGS TOO MUCH AT THIS POINT.
THE REGION WILL BE UNDER THE EASTERN PORTION OF AN UPPER LEVEL RIDGE
OF HIGH PRESSURE AT THE BEGINNING OF THE PERIOD...WITH DRY
CONDITIONS EXPECTED THROUGH DAYTIME WEDNESDAY. A SHORTWAVE TROUGH
WILL APPROACH THE REGION ON WEDNESDAY NIGHT AND MOVE OVER THE REGION
DURING THE DAYTIME ON THURSDAY. GIVEN THE INSTABILITY EXPECTED
DURING THIS PERIOD...HAVE INCLUDED MENTION OF THUNDERSTORMS WITH THE
SLIGHT CHANCE OF PRECIPITATION...THOUGH CONVECTIVE INHIBITION IS
STILL FAIRLY STRONG OVER MUCH OF THE AREA DURING THIS TIME. THE
UPPER LEVEL FLOW WILL BEGIN TO BECOME MORE ZONAL BY THE END OF THE
PERIOD AS THE UPPER RIDGE MOVES EASTWARD...AND ANOTHER SHORTWAVE
TROUGH BEGINS TO APPROACH THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1013 PM MDT FRI MAY 11 2012
PERSISTENT AREA OF RAIN SHOWERS IN NORTHEAST COLORADO WILL
GRADUALLY WORK INTO NORTHWEST KANSAS AND SOUTHWEST NEBRASKA
OVERNIGHT AND INTO SATURDAY MORNING. CURRENT RADAR TRENDS AND
LATEST MODEL GUIDANCE SUGGEST AN INCREASING RISK OF MVFR CEILINGS
AND LIGHT RAIN AT KGLD DURING THAT TIME PERIOD. ACTIVITY WILL
PROBABLY STAY WEST OF KMCK BUT WILL GET CLOSE THERE AS WELL. BY
SATURDAY AFTERNOON SHOWERS EXPECTED TO END AND CEILINGS IMPROVE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...JRM/CJS
AVIATION...024
AREA FORECAST DISCUSSION
NWS CARIBOU ME
958 PM EDT SUN MAY 13 2012
.SYNOPSIS...
A STALLED FRONTAL BOUNDARY WILL WEAKEN ACROSS DOWNEAST AREAS
THROUGH MONDAY. A DISTURBANCE WILL THEN CROSS THE REGION TUESDAY.
UNSETTLED CONDITIONS WILL PERSIST ACROSS THE REGION THROUGH MID
WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
930 PM UPDATE: LATEST RADAR IMAGERY SHOWS SHWRS LINGERING ACROSS E
CNTRL AND DOWNEAST PTNS OF THE FA OVRNGT WHERE WE HAD TO INCREASE
POPS TO HI CHC CATEGORY. ALTHOUGH LGTNG DETECTION SHOWS NO CG
STROKES IN OR NEAR OUR FA ATTM...WE ADDED ISOLD TSTMS IN CASE OF A
RUMBLE OF IN CLD THUNDER WITH RAIN REFS GREATER THAN 35 DBZ. WE
INCREASED QPF FOR THE 00-06Z PD ALG THE MAX POP AXIS TO 0.15
INCHES...WITH LOCALLY HIGHER AMTS POSSIBLE WITH A FEW HEAVIER
DOWNPOURS. MOST MODELS INDICATE SHWRS SUPPOSEDLY ALREADY ENDED BY
THIS TM...WITH ONLY THE HRRR MODEL CONTG SHWRS TIL ABOUT 04-05Z
WITH LESS CVRG ATTM THAN SHOWN IN REAL TM.
OTHERWISE...WE LOADED 01Z OBSVD SFC TEMPS WHICH INDICATED SIG
COOLING OVR DOWNEAST AREAS THAN INDICATED BY THIS TM BY PRIOR
UPDATES...LIKELY A RESULT OF THE FRONT MAKING A LITTLE MORE
PROGRESS TOWARD THE COASTLINE. LASTLY...11-3.9 LOW CLD SAT
IMAGERY INDICATES THE BACK EDGE OF LOW CLDS CURRENTLY JUST W OF A
FRENCHVILLE AIRPORT...CLAYTON LAKE LINE HAS NOT MADE MUCH PROGRESS
ACROSS NW ME OVR THE LAST 2 TO 3 HRS...LIKELY DUE TO WEAKENING
ADVCN AS LLVL WIND BECOME NEAR CALM. WITH TRAPPED LLVL MOISTURE
OVR THE FA FROM EARLIER SHWRS...LOW CLDS MAY REMAIN OVR MUCH OF
THE N THRU ERLY MORN HRS.
600 PM UPDATE: RADAR CONTS TO SHOW MOST OF THE SHWR ACTIVITY ACROSS
NRN AND CNTRL PTNS OF THE FA SLOWLY EXITING THE FA ERLY THIS EVE.
RADAR ALSO SHOWS ISOLD SHWRS WITH OCNL CG LGTNG STROKES FROM WRN
ME MOVG TOWARD DOWNEAST AREAS OF OUR FA...BUT WITH NO LGTNG ATTM...
SO WE BROUGHT ISOLD SHWRS TO THE COAST FOR THE REMAINDER OF THE EVE.
OTHERWISE...ALTHOUGH PARTIAL CLRG IS MOVG INTO NW PTNS OF THE
FA...WE ARE A LITTLE UNCERTAIN HOW QUICKLY THIS CLRG WILL GET INTO
NE AND CNTRL PTNS OF THE FA OVRNGT WITH LLVL MOISTURE LEFT OVR
FROM SHWRS EARLIER TDY...SO WE DELAYED BRINGING THE BACK EDGE OF
OVC CONDITIONS THRU THESE PTNS OF THE FA TIL ERLY THIS MORN. LASTLY
WE LOWERED OVRNGT LOWS ACROSS MSLY NRN/CNTRL PTNS OF THE BY BLENDING
NAM12...REG CANGEM GFS40 AND GMOS GUIDANCE...SINCE SPCLY ACROSS NRN
PTNS OF THE FA...CURRENT OBSVD TEMPS ARE NOT TO FAR FROM FCST LOWS...
AND WITH SOME PROSPECT OF CLRG LATER TNGT...TEMPS DO HAVE SOME
OPPORTUNITY TO FALL SPCLY OV THE NW HLF OF THE FA.
ORGNL DISC: SHOWERS IN ASSOCIATION WITH A WEAK WAVE OF LOW
PRESSURE WILL DIMINISH THROUGH THE LATE AFTERNOON INTO EARLY THIS
EVENING. HOWEVER THE FRONT ASSOCIATED WITH THIS FEATURE WILL STALL
OVER SOUTHERN PARTS OF THE ZONE FOR TONIGHT AND MONDAY. AS RESULT
EXPECT MAINLY CLOUDY SKIES TONIGHT FOR AREAS DOWNEAST WITH A
CLEARING TREND OCCURRING ACROSS THE NORTH. COMBINED WITH LIGHT
WINDS AND MOISTURE FROM TODAY`S SHOWERS THIS WILL SET UP FAVORABLE
CONDITIONS FOR FOG FORMATION. ADDED IN AREAS OF FOG FOR THE
OVERNIGHT ACROSS NORTHERN SECTIONS WITH PATCHY FOG DOWNEAST.
MONDAY WILL BEGIN DRY WITH SHOWERS REDEVELOPING FROM SOUTH TO
NORTH BY THE AFTERNOON. HIGHS FOR MONDAY WILL RANGE FROM THE MID
60S TO NEAR 70 AND WILL BE WARMEST IN THE NORTH WHERE CLOUDS AND
SHOWERS WON`T ARRIVE UNTIL LATER IN THE DAY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
A RATHER DAMP AND UNSETTLED PTRN IS IN STORE FOR THE SHORT TERM
PD... IN THE UPPER LEVELS...BROAD UPPER LONG WAVE TROF ACROSS THE
ERN THIRD OF CANADA AND THE ERN US W/ SW FLOW ALOFT ACROSS OUR
REGION. AN OLD STNRY BNDRY ACROSS DOWNEAST MAINE WILL INITIALLY ACT
AS THE FOCUS FOR SOME PRECIP AS A WEAK UPPER SHORT WAVE LIFTS NE
ALONG THIS FRONT IN THE SWRLY FLOW ALOFT. WILL CARRY LIKELY POPS
DOWNEAST MON EVE INTO MON NGT W/ POPS TRAILING OFF TO CHC AFTER
MIDNIGHT W/ CHC POPS CONTG ALL BUT FAR NRN AREAS INTO TUE AM.
DURING THE DAY TUE... MODELS BRING A STRONGER UPPER SHORT WAVE
NNEWRD W/ AN ASSOCIATED WEAK SFC LOW WHILE A COLD FRONT DROPS SEWRD
ACROSS ERN ONT PROVINCE. MODELS DIVERGE SOMEWHAT ON THE TIMING OF
THIS SYSTEM BUT GENERALLY EXPECT ANOTHER SURGE OF MOISTURE TO SPREAD
NEWRD INTO OUR SWRN/WRN AREAS LATER TUE AND WILL INCREASE POPS TO
LIKELY ALL BUT SERN AREAS BY TUE EVE. IT THEN APPEARS MOISTURE WILL
OVERSPREAD THE ENTIRE FA TUE NGT AND WILL CARRY LIKELY POPS ALL
AREAS AFTER MIDNIGHT TUE NGT. EXPECT A WET DAY ON WED AS THIS
SYSTEM LIFTS NE ACROSS THE AREA...AHEAD OF THE APPROACHING COLD
FRONT FROM THE NW. THIS FRONT WILL LIKELY ENHANCE THE RAINFALL
RATES ACROSS THE REGION LATER WED. HAVE NOT ADDED MENTION OF
THUNDER YET AS MOIST SRLY FLOW OFF THE OCEAN SHOULD LEAD TO
RELATIVELY STABLE CONDS BUT CAN NOT RULE OUT SOME ISOLD ELEVATED
CONVECTION WED AFTN SPCLY N AND W...&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE COLD FRONT WILL SWEEP EAST ACROSS THE REGION WEDNESDAY NIGHT
WITH ANY LINGERING SHOWERS ENDING WITH THE PASSAGE OF THE FRONT.
HIGH PRESSURE WILL MAKE A BRIEF RETURN THURSDAY WITH FAIR WEATHER
CONDITIONS. ANOTHER COLD FRONT WILL ENTER THE REGION FROM THE
NORTHWEST THURSDAY NIGHT AND INTO FRIDAY POSSIBLY BRINGING A
SLIGHT CHANCE OF SHOWERS TO THE REGION LATER THURSDAY NIGHT AND
FRIDAY. HIGH PRESSURE WILL BUILD IN FOR LATE WEEK AND INTO NEXT WEEKEND.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
NEAR TERM: THERE MAY BE A BRIEF REPRIEVE LATER THIS AFTERNOON INTO
THIS EVENING IN THE MVFR/IFR CONDITIONS OCCURRING IN THE NORTH
BEFORE FOG FORMATION OVERNIGHT RESULTS IN A RETURN TO AT LEAST
MVFR CONDITIONS. AREAS IN THE SOUTH WILL REMAIN VFR THROUGH THIS
EVENING WITH MVFR AND EVENTUALLY IFR CONDITIONS DEVELOPING
OVERNIGHT DUE TO PATCHY FOG AND LOW CLOUDS. ALL AREAS WILL SEE
CONDITIONS IMPROVE THROUGH MONDAY MORNING.
SHORT TERM: GENERALLY POOR FLYING CONDS ARE EXPECTED TUE/WED IN
MOIST SRLY FLOW AND WEAK SFC LOW PRES LIFTING NEWRD UP ACROSS THE
REGION. IMPROVING CONDS AS SOME COOLER AND DRIER AIR MOVES IN
BEHIND THIS SYSTEM LATER WED NGT AND REMAINING THRU LATE WEEK. &&
&&
.MARINE...
NEAR TERM: EXPECT SOME AREAS OF FOG TONIGHT WITH SHOWERS LIKELY
MONDAY. HOWEVER CONDITIONS WILL REMAIN BELOW SCA LEVELS THROUGH
MONDAY.
SHORT TERM: MARGINAL SCA CONDITIONS...MAINLY W/ ELEVATED SEAS...ARE
POSSIBLE TUE AND WED IN PERSISTENT SRLY FLOW. VISIBILITIES WILL
ALSO BE REDUCED IN FOG AND PDS OF RAIN.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...VJN
SHORT TERM...KHW
LONG TERM...DUDA
AVIATION...VJN
MARINE...VJN/KHW
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
135 PM EDT SAT MAY 12 2012
.SYNOPSIS...
ISSUED AT 514 AM EDT SAT MAY 12 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
N CNTRL CANADA THROUGH MANITOBA AND NW ONTARIO INTO THE NRN PLAINS.
A PROMINENT SHORTWAVE TROUGH WAS MOVING THROUGH NRN ONTARIO TOWARD
JAMES BAY WHILE A WEAKER TRAILING SHRTWV WAS SLIDING THROUGH NRN MN.
AT THE SFC...A COLD FRONT EXTENDED FROM LOW PRES NEAR JAMES BAY
THROUGH NRN LOWER MI. -SHRA SUPPORTED BY 850-700 MB FGEN BEHIND THE
FRONT OVER CNTRL UPPER MI WERE QUICKLY DIMINISHING AND MOVING OUT OF
THE CWA. IR LOOP SHOWED CONSIDERABLE MID CLOUDS OVER THE REGION WITH
CLEARING WEST OF LAKE SUPERIOR.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 514 AM EDT SAT MAY 12 2012
TODAY...EXPECT ANY LINGERING LIGHT SHOWERS OR SPRINKLES TO EXIT THE
CWA BY DAYBREAK. SATELLITE TRENDS AND MODELS MID LEVEL RH FCST
SUGGEST THAT SKIES SHOULD CLEAR OVER THE WEST THIS MORNING AND OVER
THE SOUTHEAST EARLY THIS AFTERNOON AS THE SFC RIDGE BUILDS INTO THE
REGION. A VERY DRY AIRMASS WILL SPREAD THROUGH UPPER MI WITH PWAT
VALUES DROPPING TO NEAR 0.20 INCHES (30-35 PERCENT OF NORMAL).
PLENTY OF SUNSHINE AND STRONG MIXING DURING THE AFTERNOON PUSHING
INLAND TEMPS INTO THE MID 60S...WILL DROP RH VALUES TO AROUND 20
PERCENT. HOWEVER...NW WINDS ONLY TO AROUND 10 MPH WILL MITIGATE FIRE
WX CONCERNS.
TONIGHT...EVEN THOUGH THE HIGH AND DRIEST AIR WILL SAG TO THE
SOUTH...FAVORABLE RADIATIONAL COOLING CONDITION SHOULD ALLOW TEMPS
TO DROP TOWARD THE LOWER END OF GUIDANCE VALUES WITH INLAND READINGS
INTO THE LOWER 30S.
SUNDAY...WAA WITH INCREASING WRLY FLOW WILL PUSH TEMPS BACK ABOVE
NORMAL WITH HIGHS IN TO THE LOWER 70S AND COOLER READINGS IN THE 60S
ONLY NEAR LAKE MICHIGAN. EVEN WITH A SLIGHT INCREASE IN LOW LEVEL
MOISTURE...RH VALUES ARE EXPECTED TO FALL INTO THE 20-25 PERCENT
RANGE...LEADING TO CONTINUED ELEVATED FIRE DANGER.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 514 AM EDT SAT MAY 12 2012
THE PERIOD STARTS 00Z MON WITH AN AMPLIFIED 500MB RIDGE OVER THE WRN
CONUS...AND A TROUGH FROM A CLOSED UPPER LOW OVER HUDSON BAY TO THE
LOWER MISSISSIPPI VALLEY. LOW LEVEL FLOW WILL BE FROM THE WSW AS THE
CWA WILL BE BETWEEN A SFC LOW OVER HUDSON BAY AND SFC RIDGING FROM
THE CENTRAL PLAIN STATES TO LAKE HURON. WARM AIR WILL BE SPILLING IN
FROM THE W...WITH 850MB TEMPS AROUND 7C OVER ERN UPPER MI...AND
AROUND 11C OVER WRN LAKE SUPERIOR. A SHORTWAVE TROUGH MOVING OVER
WILL HAVE LITTLE MOISTURE TO WORK WITH...AND WILL JUST INCREASE
CLOUD COVER.
MONDAY...LOOK FOR WARM TEMPERATURES AS 850MB TEMPS INCREASE TO A CWA
AVG TEMP OF AROUND 11C. MODELS FORECAST SOUNDINGS INDICATE POTENTIAL
FOR MIXING UP TO 700MB...PRODUCING HIGH TEMPS IN THE 70S. THIS WILL
ALSO LEAD TO LOW DEW PTS...BUT WINDS WILL BE FAIRLY LIGHT WHICH WILL
HELP REDUCE FIRE WX CONCERNS.
TUESDAY LOOKS A BIT COOLER...ESPECIALLY NEAR LAKE SUPERIOR...AS
MODELS SHOW A COLD FRONT MOVING ACROSS THE AREA. 850MB TEMPS ONLY
DROP DOWN TO A CWA AVG OF 9C...BUT THE NWLY WIND WILL KEEP LOCATIONS
NEAR LAKE SUPERIOR COOLER. 12Z/11 ECMWF AND 12Z/11 GEM SHOW LIGHT
PRECIP ACCUMULATIONS OF A COUPLE TENTHS OF A INCH /AT MOST/...WHILE
THE 00Z/12 GFS KEEPS MOST OF THE AREA DRY WITH THE FRONTAL PASSAGE.
THE AIRMASS LOOKS DRY ENOUGH TO KEEP WIDESPREAD PRECIP AT BAY...BUT
SOME CONVECTION COULD BREAK OUT INLAND AS THE FRONT PASSES. NOT
CONFIDENT ENOUGH WITH PRECIP CHANCES TO GO WITH ANY POPS ABOVE LOW
CHANCE.
A SHORTWAVE TROUGH LOOKS TO DIVE OVER OR E OF THE CWA WED...BUT
MODELS VARY ON THE TRACK...AND THEREFOR THE LOCATION OF ANY
PRECIPITATION FROM THE SYSTEM. MODELS ARE IN BETTER AGREEMENT ON WED
BEING A GOOD DEAL COLDER THAN TUE...AS 850MB TEMPS ARE 5-8 DEGREES
COLDER. WITH UNCERTAINTY ON THE TRACK OF THE SHORTWAVE...WILL USE A
CONSENSUS OF GUIDANCE.
FOR THURSDAY AND FRIDAY...MODELS ARE IN GENERAL AGREEMENT IN
BRINGING THE RIDGE ORIGINALLY OVER THE WRN CONUS OVER THE CWA THU
INTO FRI. LOW LEVEL FLOW SHOULD GENERALLY BE FROM THE S...WITH SFC
TEMPS ABOVE NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 130 PM EDT SAT MAY 12 2012
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH THIS TAF
PERIOD. CONFIDENCE IS NOT HIGH ON WHEN...HOW LONG...OR EVEN IF IWD
AND CMX WILL DECOUPLE ENOUGH TO BRING WINDS LESS THAN 12KTS...SO
TRENDED TOWARD DECREASING WINDS IN THE EVENING BEFORE PRESSURE
GRADIENT INCREASES IN THE EARLY MORNING HOURS AND SHALLOW STABLE
LAYER POTENTIALLY MIXES OUT IN THE HIGHER TERRAIN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 514 AM EDT SAT MAY 12 2012
EXPECT NORTHWEST WINDS LATE TONIGHT INTO EARLY THIS MORNING TO
REMAIN AT OR BLO 20 KTS...WITH GUSTS UP TO 25 KTS. WINDS BECOME
SOUTHWESTERLY AND DIMINISH SATURDAY AFTN AND EVENING AND SHOULD
GENERALLY STAY BLO 25 KTS INTO SUNDAY NIGHT WITH THE STRONGEST WINDS
OCCURRING OVER WESTERN LK SUPERIOR IN A SW WIND REGIME. WINDS BECOME
QUITE LIGHT...LESS THAN 15 KTS FOR MOST OF NEXT WEEK AS HIGH
PRESSURE STAYS IN THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...TK
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
822 AM EDT SAT MAY 12 2012
.SYNOPSIS...
ISSUED AT 514 AM EDT SAT MAY 12 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
N CNTRL CANADA THROUGH MANITOBA AND NW ONTARIO INTO THE NRN PLAINS.
A PROMINENT SHORTWAVE TROUGH WAS MOVING THROUGH NRN ONTARIO TOWARD
JAMES BAY WHILE A WEAKER TRAILING SHRTWV WAS SLIDING THROUGH NRN MN.
AT THE SFC...A COLD FRONT EXTENDED FROM LOW PRES NEAR JAMES BAY
THROUGH NRN LOWER MI. -SHRA SUPPORTED BY 850-700 MB FGEN BEHIND THE
FRONT OVER CNTRL UPPER MI WERE QUICKLY DIMINISHING AND MOVING OUT OF
THE CWA. IR LOOP SHOWED CONSIDERABLE MID CLOUDS OVER THE REGION WITH
CLEARING WEST OF LAKE SUPERIOR.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 514 AM EDT SAT MAY 12 2012
TODAY...EXPECT ANY LINGERING LIGHT SHOWERS OR SPRINKLES TO EXIT THE
CWA BY DAYBREAK. SATELLITE TRENDS AND MODELS MID LEVEL RH FCST
SUGGEST THAT SKIES SHOULD CLEAR OVER THE WEST THIS MORNING AND OVER
THE SOUTHEAST EARLY THIS AFTERNOON AS THE SFC RIDGE BUILDS INTO THE
REGION. A VERY DRY AIRMASS WILL SPREAD THROUGH UPPER MI WITH PWAT
VALUES DROPPING TO NEAR 0.20 INCHES (30-35 PERCENT OF NORMAL).
PLENTY OF SUNSHINE AND STRONG MIXING DURING THE AFTERNOON PUSHING
INLAND TEMPS INTO THE MID 60S...WILL DROP RH VALUES TO AROUND 20
PERCENT. HOWEVER...NW WINDS ONLY TO AROUND 10 MPH WILL MITIGATE FIRE
WX CONCERNS.
TONIGHT...EVEN THOUGH THE HIGH AND DRIEST AIR WILL SAG TO THE
SOUTH...FAVORABLE RADIATIONAL COOLING CONDITION SHOULD ALLOW TEMPS
TO DROP TOWARD THE LOWER END OF GUIDANCE VALUES WITH INLAND READINGS
INTO THE LOWER 30S.
SUNDAY...WAA WITH INCREASING WRLY FLOW WILL PUSH TEMPS BACK ABOVE
NORMAL WITH HIGHS IN TO THE LOWER 70S AND COOLER READINGS IN THE 60S
ONLY NEAR LAKE MICHIGAN. EVEN WITH A SLIGHT INCREASE IN LOW LEVEL
MOISTURE...RH VALUES ARE EXPECTED TO FALL INTO THE 20-25 PERCENT
RANGE...LEADING TO CONTINUED ELEVATED FIRE DANGER.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 514 AM EDT SAT MAY 12 2012
THE PERIOD STARTS 00Z MON WITH AN AMPLIFIED 500MB RIDGE OVER THE WRN
CONUS...AND A TROUGH FROM A CLOSED UPPER LOW OVER HUDSON BAY TO THE
LOWER MISSISSIPPI VALLEY. LOW LEVEL FLOW WILL BE FROM THE WSW AS THE
CWA WILL BE BETWEEN A SFC LOW OVER HUDSON BAY AND SFC RIDGING FROM
THE CENTRAL PLAIN STATES TO LAKE HURON. WARM AIR WILL BE SPILLING IN
FROM THE W...WITH 850MB TEMPS AROUND 7C OVER ERN UPPER MI...AND
AROUND 11C OVER WRN LAKE SUPERIOR. A SHORTWAVE TROUGH MOVING OVER
WILL HAVE LITTLE MOISTURE TO WORK WITH...AND WILL JUST INCREASE
CLOUD COVER.
MONDAY...LOOK FOR WARM TEMPERATURES AS 850MB TEMPS INCREASE TO A CWA
AVG TEMP OF AROUND 11C. MODELS FORECAST SOUNDINGS INDICATE POTENTIAL
FOR MIXING UP TO 700MB...PRODUCING HIGH TEMPS IN THE 70S. THIS WILL
ALSO LEAD TO LOW DEW PTS...BUT WINDS WILL BE FAIRLY LIGHT WHICH WILL
HELP REDUCE FIRE WX CONCERNS.
TUESDAY LOOKS A BIT COOLER...ESPECIALLY NEAR LAKE SUPERIOR...AS
MODELS SHOW A COLD FRONT MOVING ACORSS THE AREA. 850MB TEMPS ONLY
DROP DOWN TO A CWA AVG OF 9C...BUT THE NWLY WIND WILL KEEP LOCATIONS
NEAR LAKE SUPERIOR COOLER. 12Z/11 ECMWF AND 12Z/11 GEM SHOW LIGHT
PRECIP ACCUMULATIONS OF A COUPLE TENTHS OF A INCH /AT MOST/...WHILE
THE 00Z/12 GFS KEEPS MOST OF THE AREA DRY WITH THE FRONTAL PASSAGE.
THE AIRMASS LOOKS DRY ENOUGH TO KEEP WIDESPREAD PRECIP AT BAY...BUT
SOME CONVECTION COULD BREAK OUT INLAND AS THE FRONT PASSES. NOT
CONFIDENT ENOUGH WITH PRECIP CHANCES TO GO WITH ANY POPS ABOVE LOW
CHANCE.
A SHORTWAVE TROUGH LOOKS TO DIVE OVER OR E OF THE CWA WED...BUT
MODELS VARY ON THE TRACK...AND THEREFOR THE LOCATION OF ANY
PRECIPITATION FROM THE SYSTEM. MODELS ARE IN BETTER AGREEMENT ON WED
BEING A GOOD DEAL COLDER THAN TUE...AS 850MB TEMPS ARE 5-8 DEGREES
COLDER. WITH UNCERTAINTY ON THE TRACK OF THE SHORTWAVE...WILL USE A
CONSENSUS OF GUIDANCE.
FOR THURSDAY AND FRIDAY...MODELS ARE IN GENERAL AGREEMENT IN
BRINGING THE RIDGE ORIGINALLY OVER THE WRN CONUS OVER THE CWA THU
INTO FRI. LOW LEVEL FLOW SHOULD GENERALLY BE FROM THE S...WITH SFC
TEMPS ABOVE NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 821 AM EDT SAT MAY 12 2012
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH THIS TAF
PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 514 AM EDT SAT MAY 12 2012
EXPECT NORTHWEST WINDS LATE TONIGHT INTO EARLY THIS MORNING TO
REMAIN AT OR BLO 20 KTS...WITH GUSTS UP TO 25 KTS. WINDS BECOME
SOUTHWESTERLY AND DIMINISH SATURDAY AFTN AND EVENING AND SHOULD
GENERALLY STAY BLO 25 KTS INTO SUNDAY NIGHT WITH THE STRONGEST WINDS
OCCURRING OVER WESTERN LK SUPERIOR IN A SW WIND REGIME. WINDS BECOME
QUITE LIGHT...LESS THAN 15 KTS FOR MOST OF NEXT WEEK AS HIGH
PRESSURE STAYS IN THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...TITUS
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
516 AM EDT SAT MAY 12 2012
.SYNOPSIS...
ISSUED AT 514 AM EDT SAT MAY 12 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
N CNTRL CANADA THROUGH MANITOBA AND NW ONTARIO INTO THE NRN PLAINS.
A PROMINENT SHORTWAVE TROUGH WAS MOVING THROUGH NRN ONTARIO TOWARD
JAMES BAY WHILE A WEAKER TRAILING SHRTWV WAS SLIDING THROUGH NRN MN.
AT THE SFC...A COLD FRONT EXTENDED FROM LOW PRES NEAR JAMES BAY
THROUGH NRN LOWER MI. -SHRA SUPPORTED BY 850-700 MB FGEN BEHIND THE
FRONT OVER CNTRL UPPER MI WERE QUICKLY DIMINISHING AND MOVING OUT OF
THE CWA. IR LOOP SHOWED CONSIDERABLE MID CLOUDS OVER THE REGION WITH
CLEARING WEST OF LAKE SUPERIOR.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 514 AM EDT SAT MAY 12 2012
TODAY...EXPECT ANY LINGERING LIGHT SHOWERS OR SPRINKLES TO EXIT THE
CWA BY DAYBREAK. SATELLITE TRENDS AND MODELS MID LEVEL RH FCST
SUGGEST THAT SKIES SHOULD CLEAR OVER THE WEST THIS MORNING AND OVER
THE SOUTHEAST EARLY THIS AFTERNOON AS THE SFC RIDGE BUILDS INTO THE
REGION. A VERY DRY AIRMASS WILL SPREAD THROUGH UPPER MI WITH PWAT
VALUES DROPPING TO NEAR 0.20 INCHES (30-35 PERCENT OF NORMAL).
PLENTY OF SUNSHINE AND STRONG MIXING DURING THE AFTERNOON PUSHING
INLAND TEMPS INTO THE MID 60S...WILL DROP RH VALUES TO AROUND 20
PERCENT. HOWEVER...NW WINDS ONLY TO AROUND 10 MPH WILL MITIGATE FIRE
WX CONCERNS.
TONIGHT...EVEN THOUGH THE HIGH AND DRIEST AIR WILL SAG TO THE
SOUTH...FAVORABLE RADIATIONAL COOLING CONDITION SHOULD ALLOW TEMPS
TO DROP TOWARD THE LOWER END OF GUIDANCE VALUES WITH INLAND READINGS
INTO THE LOWER 30S.
SUNDAY...WAA WITH INCREASING WRLY FLOW WILL PUSH TEMPS BACK ABOVE
NORMAL WITH HIGHS IN TO THE LOWER 70S AND COOLER READINGS IN THE 60S
ONLY NEAR LAKE MICHIGAN. EVEN WITH A SLIGHT INCREASE IN LOW LEVEL
MOISTURE...RH VALUES ARE EXPECTED TO FALL INTO THE 20-25 PERCENT
RANGE...LEADING TO CONTINUED ELEVATED FIRE DANGER.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 514 AM EDT SAT MAY 12 2012
THE PERIOD STARTS 00Z MON WITH AN AMPLIFIED 500MB RIDGE OVER THE WRN
CONUS...AND A TROUGH FROM A CLOSED UPPER LOW OVER HUDSON BAY TO THE
LOWER MISSISSIPPI VALLEY. LOW LEVEL FLOW WILL BE FROM THE WSW AS THE
CWA WILL BE BETWEEN A SFC LOW OVER HUDSON BAY AND SFC RIDGING FROM
THE CENTRAL PLAIN STATES TO LAKE HURON. WARM AIR WILL BE SPILLING IN
FROM THE W...WITH 850MB TEMPS AROUND 7C OVER ERN UPPER MI...AND
AROUND 11C OVER WRN LAKE SUPERIOR. A SHORTWAVE TROUGH MOVING OVER
WILL HAVE LITTLE MOISTURE TO WORK WITH...AND WILL JUST INCREASE
CLOUD COVER.
MONDAY...LOOK FOR WARM TEMPERATURES AS 850MB TEMPS INCREASE TO A CWA
AVG TEMP OF AROUND 11C. MODELS FORECAST SOUNDINGS INDICATE POTENTIAL
FOR MIXING UP TO 700MB...PRODUCING HIGH TEMPS IN THE 70S. THIS WILL
ALSO LEAD TO LOW DEW PTS...BUT WINDS WILL BE FAIRLY LIGHT WHICH WILL
HELP REDUCE FIRE WX CONCERNS.
TUESDAY LOOKS A BIT COOLER...ESPECIALLY NEAR LAKE SUPERIOR...AS
MODELS SHOW A COLD FRONT MOVING ACORSS THE AREA. 850MB TEMPS ONLY
DROP DOWN TO A CWA AVG OF 9C...BUT THE NWLY WIND WILL KEEP LOCATIONS
NEAR LAKE SUPERIOR COOLER. 12Z/11 ECMWF AND 12Z/11 GEM SHOW LIGHT
PRECIP ACCUMULATIONS OF A COUPLE TENTHS OF A INCH /AT MOST/...WHILE
THE 00Z/12 GFS KEEPS MOST OF THE AREA DRY WITH THE FRONTAL PASSAGE.
THE AIRMASS LOOKS DRY ENOUGH TO KEEP WIDESPREAD PRECIP AT BAY...BUT
SOME CONVECTION COULD BREAK OUT INLAND AS THE FRONT PASSES. NOT
CONFIDENT ENOUGH WITH PRECIP CHANCES TO GO WITH ANY POPS ABOVE LOW
CHANCE.
A SHORTWAVE TROUGH LOOKS TO DIVE OVER OR E OF THE CWA WED...BUT
MODELS VARY ON THE TRACK...AND THEREFOR THE LOCATION OF ANY
PRECIPITATION FROM THE SYSTEM. MODELS ARE IN BETTER AGREEMENT ON WED
BEING A GOOD DEAL COLDER THAN TUE...AS 850MB TEMPS ARE 5-8 DEGREES
COLDER. WITH UNCERTAINTY ON THE TRACK OF THE SHORTWAVE...WILL USE A
CONSENSUS OF GUIDANCE.
FOR THURSDAY AND FRIDAY...MODELS ARE IN GENERAL AGREEMENT IN
BRINGING THE RIDGE ORIGINALLY OVER THE WRN CONUS OVER THE CWA THU
INTO FRI. LOW LEVEL FLOW SHOULD GENERALLY BE FROM THE S...WITH SFC
TEMPS ABOVE NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 121 AM EDT SAT MAY 12 2012
EXPECT ANY LINGERING -SHRA AT SAW TO END SHORTLY AFTER TAF ISSUANCE
WITH THE ARRIVAL OF DRIER AIR ASSOCIATED WITH HI PRES MOVING EWD
FROM THE PLAINS. THIS HI WL BRING VFR CONDITIONS TO THE AREA TODAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 514 AM EDT SAT MAY 12 2012
EXPECT NORTHWEST WINDS LATE TONIGHT INTO EARLY THIS MORNING TO
REMAIN AT OR BLO 20 KTS...WITH GUSTS UP TO 25 KTS. WINDS BECOME
SOUTHWESTERLY AND DIMINISH SATURDAY AFTN AND EVENING AND SHOULD
GENERALLY STAY BLO 25 KTS INTO SUNDAY NIGHT WITH THE STRONGEST WINDS
OCCURRING OVER WESTERN LK SUPERIOR IN A SW WIND REGIME. WINDS BECOME
QUITE LIGHT...LESS THAN 15 KTS FOR MOST OF NEXT WEEK AS HIGH
PRESSURE STAYS IN THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...KC
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
242 PM EDT SAT MAY 12 2012
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT TO THE CAROLINA COAST TODAY WHILE A WEAK
COLD FRONT PUSHES INTO THE CENTRAL GREAT LAKES. THIS COLD FRONT WILL
GRADUALLY SAG ACROSS THE REGION LATE TONIGHT AND SUNDAY WITH AN
INCREASE IN CLOUD COVER AND A CHANCE OF A FEW LIGHT SHOWERS. THE
FRONT WILL STALL OVER OR JUST SOUTHEAST OF THE AREA SUNDAY NIGHT AND
MONDAY AND BRING MORE CLOUD COVER AND A FEW SHOWERS. THIS FRONT WILL
ONLY PUSH VERY SLOWLY EAST THROUGH THE MIDDLE OF NEXT WEEK WITH A
CHANCE OF SHOWERS LINGERING ACROSS CENTRAL NEW YORK WHILE WESTERN NY
MAY REMAIN MAINLY DRY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS HIGH PRESSURE
CENTERED OVER THE PIEDMONT WITH A WEAK COLD FRONT WELL UPSTREAM
ACROSS LAKE HURON. SHOWERS ALONG THE BOUNDARY ARE FAIRLY WELL
CAPTURED BY THE HRRR AND 12Z RUNS OF THE NAM/GFS/RGEM. THIS
BOUNDARY WILL BE VERY SLOW TO DRIFT SOUTH...WITH SHOWERS EXPECTED
TO BE VERY SLOW TO APPROACH WESTERN NEW YORK FOR THE REMAINDER OF
TODAY. ABOUT THE ONLY IMPACT FROM THIS BOUNDARY WILL BE
INCREASING MID AND HIGH CLOUDS THIS AFTERNOON. OTHERWISE...THIS A
QUITE WARM AIR MASS...WITH THE 12Z BUF SOUNDING SHOWING 850 MB
TEMPS TO +9C. EXPECT INTERIOR SECTIONS TO RISE INTO THE UPPER
70S...WITH PORTIONS OF THE FINGER LAKES LIKELY TO REACH 80 TODAY.
THE LAKE BREEZE WILL KEEP THE IMMEDIATE LAKESHORES COOLER...WITH
BUFFALO METRO LIKELY TO TOP OUT IN THE UPPER 60S TO LOWER 70S
DEPENDING ON PROXIMITY TO THE LAKESHORE.
SPEAKING OF WINDS...THOSE SOUTHWEST WINDS WILL CONTINUE TO BE
GUSTY THROUGH THIS AFTERNOON AS A BELT OF 25-35 KNOT WINDS AT
925 MB CROSSES THE LOWER LAKES DURING PEAK DAYTIME MIXING. THIS
WILL ALLOW GUSTS TO REACH 30-35 MPH AT THE SURFACE FROM THE
NIAGARA FRONTIER NORTHEAST TO KROC...WHICH IS THE FAVORED AREA FOR
STRONGER SOUTHWEST WINDS. THE STRONGEST WINDS WILL LIKELY BE FROM
NEAR THE BUF AIRPORT INTO THE EAST AND NORTHEAST SUBURBS AS THE
FLOW FOLLOWS ISENTROPIC SURFACES AND ESSENTIALLY DOWNSLOPES OFF
THE DOME OF COOLER/STABLE AIR OVER LAKE ERIE. THAT SAME DOME OF
COOLER MORE STABLE AIR WILL KEEP WINDS SOMEWHAT LIGHTER OVER LAKE
ERIE AND IN DOWNTOWN BUFFALO.
FOR TONIGHT...THE WINDS WILL DIMINISH QUICKLY THIS EVENING AS THE
BELT OF STRONGER 925MB WINDS WEAKENS AND DAYTIME MIXING ENDS. CLOUDS
WILL CONTINUE TO THICKEN AND INCREASE FROM NORTHWEST TO SOUTHEAST IN
ADVANCE OF THE WEAK FRONTAL BOUNDARY...WHICH WILL SAG SOUTH INTO THE
REGION AFTER 06Z SUNDAY. MODEST MID LEVEL HEIGHT FALLS AND PVA WILL
SUPPORT WEAK LARGE SCALE ASCENT...AND WEAK FRONTOGENESIS IN THE
850-700MB LAYER WILL SUPPORT SOME CONVERGENCE ALONG AND BEHIND THE
SURFACE COLD FRONT. ALL OF THIS WEAK FORCING MAY BE JUST ENOUGH TO
PRODUCE A FEW SCATTERED LIGHT SHOWERS LATE TONIGHT...MAINLY FROM THE
NIAGARA FRONTIER EAST TO ROCHESTER AND THE NORTH COUNTRY. AMOUNTS
WILL BE MINUSCULE GIVEN WEAK FORCING IN PLAY...WITH A FEW HUNDREDTHS
OF AN INCH IN SPOTTY LIGHT SHOWERS.
THE INCREASE IN CLOUD COVER AND SOME MIXING OVERNIGHT WILL KEEP LOWS
IN THE LOWER 50S ON THE LAKE PLAINS. SOME OF THE SHELTERED SOUTHERN
TIER VALLEYS WILL STILL DECOUPLE...AND CLOUDS WILL BE SLOWER TO
INCREASE THERE WHICH WILL ALLOW A FEW SPOTS TO RADIATE INTO THE MID
40S.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
DURING THE COURSE OF SUNDAY...A WEAK COOL FRONT DRAPED ACROSS LAKES
ERIE AND ONTARIO AT THE START OF THE DAY WILL EVER SO SLOWLY SAG
SOUTH ACROSS THE CWA...WITH ITS SLOW PROGRESS DUE BOTH TO ITS NEAR
PARALLEL NATURE TO THE UPPER LEVEL FLOW...AND THE DEVELOPMENT OF A
WEAK WAVE OF LOW PRESSURE OVER THE TENNESSEE AND OHIO VALLEYS. THIS
FRONT WILL BE RELATIVELY STARVED FOR BOTH MOISTURE AND LIFT...SO FOR
MOST AREAS IT WILL ONLY BRING AN INCREASE IN CLOUD COVER AND A
LOW-END CHANCE FOR SOME LIGHT SHOWERS AND/OR SPRINKLES.
THE EXCEPTION TO THIS WILL COME LATER IN THE AFTERNOON ACROSS
THE SOUTHERN TIER AND INTERIOR SECTIONS OF THE FINGER LAKES...WHERE
THE FRONT WILL BEGIN TO INTERCEPT INCREASING AMOUNTS OF MOISTURE
LIFTING NORTHEAST FROM THE OHIO VALLEY...AND MAY ALSO ENCOUNTER SOME
LIMITED SURFACE-BASED INSTABILITY. THIS WILL RESULT IN A SOMEWHAT
HIGHER SHOWER POTENTIAL...AND ALSO THE POSSIBILITY OF A THUNDERSTORM
OR TWO. FOR THIS REASON...HAVE RAISED POPS TO HIGH CHANCE FOR THIS
LATTER AREA AND TIME FRAME...AND HAVE ALSO INSERTED A LOW CHANCE OF
SOME THUNDER.
BY SUNDAY EVENING...A CONSENSUS OF THE 00Z NAM/GFS/GEM/ECMWF HAS THE
SURFACE FRONTAL BOUNDARY TO BE DRAPED FROM WEST-CENTRAL PA
NORTHEASTWARD INTO CENTRAL AND EASTERN NEW YORK...WHERE IT WILL
LIKELY REMAIN IN PLACE THROUGH THE NIGHT AND MUCH OF MONDAY AS THE
AFOREMENTIONED WEAK WAVE OF LOW PRESSURE LIFTS NORTHEAST ALONG THE
BOUNDARY. INCREASING MOISTURE AND LIFT ASSOCIATED WITH THE PASSING
WAVE WILL RESULT IN AN INCREASING LIKELIHOOD OF SHOWERS ALONG THE
BOUNDARY...THOUGH THE BEST POTENTIAL FOR THESE STILL LOOKS TO LIE
JUST A LITTLE TO OUR EAST ACROSS CENTRAL AND EASTERN NY. FOR OUR
CWA...WILL INDICATE A GRADIENT IN POPS...WITH PRECIP CHANCES RANGING
FROM HIGH CHANCE ALONG OUR EASTERN PERIPHERY...TO LOW CHANCE OR EVEN
SLIGHT CHANCE ACROSS EXTREME FAR WESTERN NEW YORK AND THE SAINT
LAWRENCE VALLEY.
WITH THIS INITIAL SURFACE WAVE STILL LOOKING TO LARGELY PASS OFF TO
OUR EAST BY LATER MONDAY AFTERNOON OR EARLY MONDAY EVENING...HAVE
CONTINUED TO INDICATE A DOWNWARD TREND IN PRECIP CHANCES MONDAY
AFTERNOON...WITH JUST SOME LOW-END CHANCE POPS LINGERING ACROSS FAR
EASTERN SECTIONS BY EARLY MONDAY EVENING. AFTER THAT...HAVE PRETTY
MUCH HELD THESE PRECIP CHANCES IN PLACE RIGHT THROUGH MONDAY NIGHT
AS THE GFS/GEM/ECMWF ALL RIDGE A NARROW WEDGE OF HIGH PRESSURE
INTO FAR WESTERN NEW YORK...WHILE LIFTING A SECONDARY WAVE OF LOW
PRESSURE INTO CENTRAL AND EASTERN PA/NY.
DESPITE THE AFOREMENTIONED PRECIP CHANCES AND WHAT SHOULD BE
RELATIVELY CLOUDY CONDITIONS...TEMPS THROUGH THIS PERIOD WILL
AVERAGE CLOSE TO OR A LITTLE ABOVE AVERAGE AS A SEASONABLY MILD
AIR MASS REMAINS IN PLACE ACROSS THE LOWER GREAT LAKES. 850 MB TEMPS
WILL GENERALLY RANGE FROM +7C TO +8C WHICH WILL SUPPORTIVE OF HIGHS
IN THE UPPER 60S/LOWER 70S BOTH DAYS...WHILE NIGHTTIME LOWS FALL
INTO THE MID 40S TO LOWER 50S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ON TUESDAY...THE GFS/ECMWF ARE IN DECENT AGREEMENT THAT THE
SECONDARY LOW PRESSURE WAVE WILL PASS ACROSS CENTRAL AND EASTERN NEW
YORK...GENERALLY ALONG A PATH SIMILAR OR A LITTLE TO THE EAST OF ITS
PREDECESSOR SUNDAY NIGHT AND MONDAY. THIS SHOULD ONCE AGAIN KEEP THE
BULK OF ITS MORE WIDESPREAD SHOWER ACTIVITY TO THE EAST OF OUR
CWA...THOUGH WILL KEEP SOME LOW CHANCE POPS IN PLACE AS FAR WEST AS
THE GENESEE VALLEY TO COVER ITS PASSAGE. FURTHER TO THE WEST...FAR
WESTERN NEW YORK WILL LIKELY REMAIN DRY AS IT WILL BE SITUATED UNDER
NARROW SURFACE RIDGING BETWEEN THE AFOREMENTIONED COASTAL
SYSTEM...AND THE NEXT UPPER LEVEL TROUGH/SURFACE WAVE THAT WILL BE
IN THE PROCESS OF DIGGING INTO THE UPPER GREAT LAKES. THE SECONDARY
COASTAL WAVE WILL THEN LIFT OUT ACROSS NEW ENGLAND DURING THE COURSE
OF TUESDAY NIGHT...WITH LINGERING SHOWER CHANCES DIMINISHING ACROSS
CENTRAL AND EASTERN SECTIONS IN ITS WAKE.
THEREAFTER...THE MEDIUM RANGE GUIDANCE AGREES ON DIGGING THE
APPROACHING UPPER TROUGH/ASSOCIATED SURFACE REFLECTION ACROSS THE
LOWER LAKES REGION ON WEDNESDAY...WITH EXPANSIVE SURFACE-BASED
RIDGING THEN BUILDING ACROSS THE AREA IN ITS WAKE THURSDAY AND
FRIDAY ALONG WITH SLOWLY BUILDING HEIGHTS ALOFT. THIS WILL RESULT IN
THE CHANCE FOR SOME SCATTERED SHOWERS AND THUNDERSTORMS ON
WEDNESDAY...FOLLOWED BY A RETURN TO DRY WEATHER FOR BOTH THURSDAY
AND FRIDAY.
AS FOR TEMPERATURES...EXPECT SEASONABLE TO SLIGHTLY ABOVE AVERAGE
TEMPERATURES TO CONTINUE THROUGH TUESDAY AND WEDNESDAY WITH LITTLE
IN THE WAY OF AN AIR MASS CHANGE EXPECTED THROUGH THAT TIME. SOMEWHAT
COOLER TEMPS MAY THEN BRIEFLY RETURN FOR WEDNESDAY NIGHT AND
THURSDAY WITH THE PASSAGE OF THE UPPER TROUGH...BEFORE READINGS
RECOVER BACK TO SEASONABLE LEVELS ON FRIDAY UNDER THE BUILDING
RIDGING.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
WINDS WILL BE GUSTY THROUGH THE REMAINDER OF THE AFTERNOON...
ESPECIALLY AT BUF/IAG/ROC. OTHERWISE...ANY CLOUDS WILL BE
HIGH...WITH VFR CONDITIONS HIGHLY LIKELY.
A WEAK COLD FRONT WILL SLOWLY APPROACH FROM THE NORTHWEST TONIGHT. AT
NIGHT...THIS BOUNDARY SHOULD NOT BE VERY ACTIVE...WITH SHOWERS
EXPECTED TO BE SCATTERED IN NATURE. TIMING IS ALSO PROBLEMATIC
GIVEN THE SLOW MOTION OF THE FRONT. BECAUSE THE FRONT IS
WEAK...IT WILL HAVE MINIMAL IMPACT ON OPERATIONS...WITH ONLY LIGHT
WINDS WITH THE BOUNDARY. ALSO...MARGINAL LOW LEVEL MOISTURE SUGGESTS THERE
WILL LIKELY BE VFR CONDITIONS WITH THE FRONT...THOUGH MVFR CANNOT
COMPLETELY RULED OUT.
EXPECT SHOWERS TO LINGER ON SUNDAY...PERHAPS ENHANCING A BIT
DURING THE AFTERNOON DUE TO DAYTIME HEATING. THE BEST CHANCE FOR
SHOWERS IS AT JHW...CLOSEST TO THE BOUNDARY.
OUTLOOK...
SUNDAY NIGHT AND MONDAY...VFR/MVFR WITH A CHANCE OF SHOWERS.
TUESDAY AND WEDNESDAY...MAINLY VFR WITH A CHANE OF A FEW SHOWERS.
THURSDAY...VFR.
&&
.MARINE...
WINDS WILL VARY DUE TO LAKE INFLUENCES...WITH THE RELATIVELY COOLER
WATERS ON THE LAKES ACTING AS A STABILIZING INFLUENCE. THE RESULT
WILL BE GENERALLY CALMER WINDS CLOSER TO THE CENTER OF THE
LAKES...WITH STRONGER WINDS ON THE IMMEDIATE SHORELINE. SOUTHWEST
WINDS IN THE 10 TO 20 KNOT RANGE ON LAKE ERIE SHOULD QUICKLY
DIMINISH THIS EVENING. BECAUSE OF LESSER WINDS FURTHER
OFFSHORE...EXPECT WAVES TO REMAIN IN THE 2 TO 3 FOOT RANGE...BELOW
SMALL CRAFT CRITERIA.
OTHERWISE...A WEAK COLD FRONT WILL DROP ACROSS THE WATERS
TONIGHT...FOLLOWED BY WEAK HIGH PRESSURE EARLY NEXT WEEK. THIS
SHOULD RESULT IN A RELATIVELY LIGHT WINDS ON THE WATERS WHICH SHOULD
LAST WELL INTO NEXT WEEK. WIND DIRECTION WILL VARY DUE TO LAKE BREEZE
INFLUENCES.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL/HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
142 PM EDT SAT MAY 12 2012
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT TO THE CAROLINA COAST TODAY WHILE A WEAK
COLD FRONT PUSHES INTO THE CENTRAL GREAT LAKES. THIS COLD FRONT WILL
GRADUALLY SAG ACROSS THE REGION LATE TONIGHT AND SUNDAY WITH AN
INCREASE IN CLOUD COVER AND A CHANCE OF A FEW LIGHT SHOWERS. THE
FRONT WILL STALL OVER OR JUST SOUTHEAST OF THE AREA SUNDAY NIGHT AND
MONDAY AND BRING MORE CLOUD COVER AND A FEW SHOWERS. THIS FRONT WILL
ONLY PUSH VERY SLOWLY EAST THROUGH THE MIDDLE OF NEXT WEEK WITH A
CHANCE OF SHOWERS LINGERING ACROSS CENTRAL NEW YORK WHILE WESTERN NY
MAY REMAIN MAINLY DRY.
&&
.NEAR TERM /THROUGH TONIGHT/...
SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS HIGH PRESSURE
CENTERED OVER THE PIEDMONT WITH A WEAK COLD FRONT WELL UPSTREAM
ACROSS LAKE HURON. SHOWERS ALONG THE BOUNDARY ARE FAIRLY WELL
CAPTURED BY THE HRRR AND 12Z RUNS OF THE NAM/GFS/RGEM. THIS
BOUNDARY WILL BE VERY SLOW TO DRIFT SOUTH...WITH SHOWERS EXPECTED
TO BE VERY SLOW TO APPROACH WESTERN NEW YORK FOR THE REMAINDER OF
TODAY. ABOUT THE ONLY IMPACT FROM THIS BOUNDARY WILL BE
INCREASING MID AND HIGH CLOUDS THIS AFTERNOON. OTHERWISE...THIS A
QUITE WARM AIR MASS...WITH THE 12Z BUF SOUNDING SHOWING 850 MB
TEMPS TO +9C. EXPECT INTERIOR SECTIONS TO RISE INTO THE UPPER
70S...WITH PORTIONS OF THE FINGER LAKES LIKELY TO REACH 80 TODAY.
THE LAKE BREEZE WILL KEEP THE IMMEDIATE LAKESHORES COOLER...WITH
BUFFALO METRO LIKELY TO TOP OUT IN THE UPPER 60S TO LOWER 70S
DEPENDING ON PROXIMITY TO THE LAKESHORE.
SPEAKING OF WINDS...THOSE SOUTHWEST WINDS WILL CONTINUE TO BE
GUSTY THROUGH THIS AFTERNOON AS A BELT OF 25-35 KNOT WINDS AT
925 MB CROSSES THE LOWER LAKES DURING PEAK DAYTIME MIXING. THIS
WILL ALLOW GUSTS TO REACH 30-35 MPH AT THE SURFACE FROM THE
NIAGARA FRONTIER NORTHEAST TO KROC...WHICH IS THE FAVORED AREA FOR
STRONGER SOUTHWEST WINDS. THE STRONGEST WINDS WILL LIKELY BE FROM
NEAR THE BUF AIRPORT INTO THE EAST AND NORTHEAST SUBURBS AS THE
FLOW FOLLOWS ISENTROPIC SURFACES AND ESSENTIALLY DOWNSLOPES OFF
THE DOME OF COOLER/STABLE AIR OVER LAKE ERIE. THAT SAME DOME OF
COOLER MORE STABLE AIR WILL KEEP WINDS SOMEWHAT LIGHTER OVER LAKE
ERIE AND IN DOWNTOWN BUFFALO.
FOR TONIGHT...THE WINDS WILL DIMINISH QUICKLY THIS EVENING AS THE
BELT OF STRONGER 925MB WINDS WEAKENS AND DAYTIME MIXING ENDS. CLOUDS
WILL CONTINUE TO THICKEN AND INCREASE FROM NORTHWEST TO SOUTHEAST IN
ADVANCE OF THE WEAK FRONTAL BOUNDARY...WHICH WILL SAG SOUTH INTO THE
REGION AFTER 06Z SUNDAY. MODEST MID LEVEL HEIGHT FALLS AND PVA WILL
SUPPORT WEAK LARGE SCALE ASCENT...AND WEAK FRONTOGENESIS IN THE
850-700MB LAYER WILL SUPPORT SOME CONVERGENCE ALONG AND BEHIND THE
SURFACE COLD FRONT. ALL OF THIS WEAK FORCING MAY BE JUST ENOUGH TO
PRODUCE A FEW SCATTERED LIGHT SHOWERS LATE TONIGHT...MAINLY FROM THE
NIAGARA FRONTIER EAST TO ROCHESTER AND THE NORTH COUNTRY. AMOUNTS
WILL BE MINUSCULE GIVEN WEAK FORCING IN PLAY...WITH A FEW HUNDREDTHS
OF AN INCH IN SPOTTY LIGHT SHOWERS.
THE INCREASE IN CLOUD COVER AND SOME MIXING OVERNIGHT WILL KEEP LOWS
IN THE LOWER 50S ON THE LAKE PLAINS. SOME OF THE SHELTERED SOUTHERN
TIER VALLEYS WILL STILL DECOUPLE...AND CLOUDS WILL BE SLOWER TO
INCREASE THERE WHICH WILL ALLOW A FEW SPOTS TO RADIATE INTO THE MID
40S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
DURING THE COURSE OF SUNDAY...A WEAK COOL FRONT DRAPED ACROSS LAKES
ERIE AND ONTARIO AT THE START OF THE DAY WILL EVER SO SLOWLY SAG
SOUTH ACROSS THE CWA...WITH ITS SLOW PROGRESS DUE BOTH TO ITS NEAR
PARALLEL NATURE TO THE UPPER LEVEL FLOW...AND THE DEVELOPMENT OF A
WEAK WAVE OF LOW PRESSURE OVER THE TENNESSEE AND OHIO VALLEYS. THIS
FRONT WILL BE RELATIVELY STARVED FOR BOTH MOISTURE AND LIFT...SO FOR
MOST AREAS IT WILL ONLY BRING AN INCREASE IN CLOUD COVER AND A
LOW-END CHANCE FOR SOME LIGHT SHOWERS AND/OR SPRINKLES.
THE EXCEPTION TO THIS WILL COME LATER IN THE AFTERNOON ACROSS
THE SOUTHERN TIER AND INTERIOR SECTIONS OF THE FINGER LAKES...WHERE
THE FRONT WILL BEGIN TO INTERCEPT INCREASING AMOUNTS OF MOISTURE
LIFTING NORTHEAST FROM THE OHIO VALLEY...AND MAY ALSO ENCOUNTER SOME
LIMITED SURFACE-BASED INSTABILITY. THIS WILL RESULT IN A SOMEWHAT
HIGHER SHOWER POTENTIAL...AND ALSO THE POSSIBILITY OF A THUNDERSTORM
OR TWO. FOR THIS REASON...HAVE RAISED POPS TO HIGH CHANCE FOR THIS
LATTER AREA AND TIME FRAME...AND HAVE ALSO INSERTED A LOW CHANCE OF
SOME THUNDER.
BY SUNDAY EVENING...A CONSENSUS OF THE 00Z NAM/GFS/GEM/ECMWF HAS THE
SURFACE FRONTAL BOUNDARY TO BE DRAPED FROM WEST-CENTRAL PA
NORTHEASTWARD INTO CENTRAL AND EASTERN NEW YORK...WHERE IT WILL
LIKELY REMAIN IN PLACE THROUGH THE NIGHT AND MUCH OF MONDAY AS THE
AFOREMENTIONED WEAK WAVE OF LOW PRESSURE LIFTS NORTHEAST ALONG THE
BOUNDARY. INCREASING MOISTURE AND LIFT ASSOCIATED WITH THE PASSING
WAVE WILL RESULT IN AN INCREASING LIKELIHOOD OF SHOWERS ALONG THE
BOUNDARY...THOUGH THE BEST POTENTIAL FOR THESE STILL LOOKS TO LIE
JUST A LITTLE TO OUR EAST ACROSS CENTRAL AND EASTERN NY. FOR OUR
CWA...WILL INDICATE A GRADIENT IN POPS...WITH PRECIP CHANCES RANGING
FROM HIGH CHANCE ALONG OUR EASTERN PERIPHERY...TO LOW CHANCE OR EVEN
SLIGHT CHANCE ACROSS EXTREME FAR WESTERN NEW YORK AND THE SAINT
LAWRENCE VALLEY.
WITH THIS INITIAL SURFACE WAVE STILL LOOKING TO LARGELY PASS OFF TO
OUR EAST BY LATER MONDAY AFTERNOON OR EARLY MONDAY EVENING...HAVE
CONTINUED TO INDICATE A DOWNWARD TREND IN PRECIP CHANCES MONDAY
AFTERNOON...WITH JUST SOME LOW-END CHANCE POPS LINGERING ACROSS FAR
EASTERN SECTIONS BY EARLY MONDAY EVENING. AFTER THAT...HAVE PRETTY
MUCH HELD THESE PRECIP CHANCES IN PLACE RIGHT THROUGH MONDAY NIGHT
AS THE GFS/GEM/ECMWF ALL RIDGE A NARROW WEDGE OF HIGH PRESSURE
INTO FAR WESTERN NEW YORK...WHILE LIFTING A SECONDARY WAVE OF LOW
PRESSURE INTO CENTRAL AND EASTERN PA/NY.
DESPITE THE AFOREMENTIONED PRECIP CHANCES AND WHAT SHOULD BE
RELATIVELY CLOUDY CONDITIONS...TEMPS THROUGH THIS PERIOD WILL
AVERAGE CLOSE TO OR A LITTLE ABOVE AVERAGE AS A SEASONABLY MILD
AIR MASS REMAINS IN PLACE ACROSS THE LOWER GREAT LAKES. 850 MB TEMPS
WILL GENERALLY RANGE FROM +7C TO +8C WHICH WILL SUPPORTIVE OF HIGHS
IN THE UPPER 60S/LOWER 70S BOTH DAYS...WHILE NIGHTTIME LOWS FALL
INTO THE MID 40S TO LOWER 50S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ON TUESDAY...THE GFS/ECMWF ARE IN DECENT AGREEMENT THAT THE
SECONDARY LOW PRESSURE WAVE WILL PASS ACROSS CENTRAL AND EASTERN NEW
YORK...GENERALLY ALONG A PATH SIMILAR OR A LITTLE TO THE EAST OF ITS
PREDECESSOR SUNDAY NIGHT AND MONDAY. THIS SHOULD ONCE AGAIN KEEP THE
BULK OF ITS MORE WIDESPREAD SHOWER ACTIVITY TO THE EAST OF OUR
CWA...THOUGH WILL KEEP SOME LOW CHANCE POPS IN PLACE AS FAR WEST AS
THE GENESEE VALLEY TO COVER ITS PASSAGE. FURTHER TO THE WEST...FAR
WESTERN NEW YORK WILL LIKELY REMAIN DRY AS IT WILL BE SITUATED UNDER
NARROW SURFACE RIDGING BETWEEN THE AFOREMENTIONED COASTAL
SYSTEM...AND THE NEXT UPPER LEVEL TROUGH/SURFACE WAVE THAT WILL BE
IN THE PROCESS OF DIGGING INTO THE UPPER GREAT LAKES. THE SECONDARY
COASTAL WAVE WILL THEN LIFT OUT ACROSS NEW ENGLAND DURING THE COURSE
OF TUESDAY NIGHT...WITH LINGERING SHOWER CHANCES DIMINISHING ACROSS
CENTRAL AND EASTERN SECTIONS IN ITS WAKE.
THEREAFTER...THE MEDIUM RANGE GUIDANCE AGREES ON DIGGING THE
APPROACHING UPPER TROUGH/ASSOCIATED SURFACE REFLECTION ACROSS THE
LOWER LAKES REGION ON WEDNESDAY...WITH EXPANSIVE SURFACE-BASED
RIDGING THEN BUILDING ACROSS THE AREA IN ITS WAKE THURSDAY AND
FRIDAY ALONG WITH SLOWLY BUILDING HEIGHTS ALOFT. THIS WILL RESULT IN
THE CHANCE FOR SOME SCATTERED SHOWERS AND THUNDERSTORMS ON
WEDNESDAY...FOLLOWED BY A RETURN TO DRY WEATHER FOR BOTH THURSDAY
AND FRIDAY.
AS FOR TEMPERATURES...EXPECT SEASONABLE TO SLIGHTLY ABOVE AVERAGE
TEMPERATURES TO CONTINUE THROUGH TUESDAY AND WEDNESDAY WITH LITTLE
IN THE WAY OF AN AIR MASS CHANGE EXPECTED THROUGH THAT TIME. SOMEWHAT
COOLER TEMPS MAY THEN BRIEFLY RETURN FOR WEDNESDAY NIGHT AND
THURSDAY WITH THE PASSAGE OF THE UPPER TROUGH...BEFORE READINGS
RECOVER BACK TO SEASONABLE LEVELS ON FRIDAY UNDER THE BUILDING
RIDGING.
&&
.AVIATION /17Z SATURDAY THROUGH WEDNESDAY/...
WINDS WILL BE GUSTY THROUGH THE REMAINDER OF THIS AFTERNOON...ESPECIALLY
AT BUF AND IAG. OTHERWISE...ANY CLOUDS WILL BE HIGH...WITH VFR
CONDITIONS HIGHLY LIKELY.
A WEAK COLD FRONT WILL SLOWLY APPROACH FROM THE NORTH TONIGHT. AT
NIGHT...THIS BOUNDARY SHOULD NOT BE VERY ACTIVE...WITH SHOWERS
EXPECTED TO BE SCATTERED IN NATURE. TIMING IS ALSO PROBLEMATIC
GIVEN THE SLOW MOTION OF THE FRONT. BECAUSE THE FRONT IS
WEAK...IT WILL HAVE MINIMAL IMPACT ON OPERATIONS...WITH ONLY
LIGHT POST-FRONTAL WINDS. ALSO...MARGINAL LOW LEVEL MOISTURE
SUGGESTS THERE WILL LIKELY BE VFR CONDITIONS WITH THE
FRONT...THOUGH MVFR CANNOT COMPLETELY RULED OUT.
EXPECT SHOWERS TO LINGER ON SUNDAY...PERHAPS ENHANCING A BIT
DURING THE AFTERNOON DUE TO DAYTIME HEATING. THE BEST CHANCE FOR
SHOWERS IS AT JHW...CLOSEST TO THE BOUNDARY.
OUTLOOK...
SUNDAY NIGHT AND MONDAY...VFR/MVFR WITH A CHANCE OF SHOWERS.
TUESDAY...VFR WEST WITH VFR/MVFR EAST OF THE GENESEE VALLEY WITH A
CHANCE OF SHOWERS.
WEDNESDAY...MAINLY VFR WITH A CHANCE OF A FEW SHOWERS AND
THUNDERSTORMS.
&&
.MARINE...
SOUTHWEST WINDS WILL INCREASE INTO THE 10-15 KNOT RANGE TODAY AS THE
PRESSURE GRADIENT TIGHTENS BETWEEN DEPARTING HIGH PRESSURE OVER THE
CAROLINAS AND A WEAK COLD FRONT OVER THE UPPER GREAT LAKES. WINDS
MAY BRIEFLY EXCEED 15 KNOTS ON LAKE ERIE AND WESTERN LAKE ONTARIO
DURING THE MID TO LATE MORNING...BUT THE WARMER AIR MASS MOVING
INTO THE REGION TODAY SHOULD PROMOTE THE DEVELOPMENT OF A STABLE
DOME OF LAKE COOLED AIR OVER LAKES ERIE AND ONTARIO...WHICH
TYPICALLY KEEPS WINDS LIGHTER OVER THE LAKES THIS TIME OF YEAR.
WITH THIS IN MIND... WILL KEEP CONDITIONS BELOW SMALL CRAFT
ADVISORY CRITERIA WITH WINDS PEAKING AT A LITTLE OVER 15 KNOTS AND
WAVES 2-3 FEET.
WINDS WILL BE VERY LIGHT ON SUNDAY AS A WEAK COLD FRONT SLOWLY SAGS
SOUTH ACROSS THE REGION AND WEAKENS THE PRESSURE GRADIENT. LIGHT
WINDS AND FLAT WAVE ACTION WILL CONTINUE THROUGH THE FIRST HALF OF
NEXT WEEK.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL/HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1047 AM EDT SAT MAY 12 2012
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT TO THE CAROLINA COAST TODAY WHILE A WEAK
COLD FRONT PUSHES INTO THE CENTRAL GREAT LAKES. THIS COLD FRONT WILL
GRADUALLY SAG ACROSS THE REGION LATE TONIGHT AND SUNDAY WITH AN
INCREASE IN CLOUD COVER AND A CHANCE OF A FEW LIGHT SHOWERS. THE
FRONT WILL STALL OVER OR JUST SOUTHEAST OF THE AREA SUNDAY NIGHT AND
MONDAY AND BRING MORE CLOUD COVER AND A FEW SHOWERS. THIS FRONT WILL
ONLY PUSH VERY SLOWLY EAST THROUGH THE MIDDLE OF NEXT WEEK WITH A
CHANCE OF SHOWERS LINGERING ACROSS CENTRAL NEW YORK WHILE WESTERN NY
MAY REMAIN MAINLY DRY.
&&
.NEAR TERM /THROUGH TONIGHT/...
SURFACE ANALYSIS LATE THIS MORNING SHOWS HIGH PRESSURE CENTERED
OVER THE PIEDMONT WITH A WEAK COLD FRONT WELL UPSTREAM ACROSS THE
WESTERN GREAT LAKES. SHOWERS ALONG THE BOUNDARY ARE FAIRLY WELL
CAPTURED BY THE HRRR AND 18Z RUNS OF THE NAM/GFS. THIS BOUNDARY
SHOULD BE VERY SLOW TO DRIFT SOUTH...WITH ALL MODEL GUIDANCE
KEEPING WESTERN NEW YORK DRY THROUGH THIS EVENING. ABOUT THE ONLY
IMPACT FROM THIS BOUNDARY WILL BE INCREASING MID AND HIGH CLOUDS
THIS AFTERNOON. OTHERWISE...THIS A QUITE WARM AIRMASS...WITH THE
12Z BUF SOUNDING SHOWING 850 MB TEMPS TO +9C. THIS SOUNDING
SUGGESTS HIGHS MAY EVEN PUSH 80 DEGREES IN INTERIOR LOCATIONS AWAY
FOR THE LAKE BREEZE...WITH HIGHS COOLER ALONG THE IMMEDIATE
LAKESHORE.
SPEAKING OF WINDS...THOSE SOUTHWEST WINDS WILL BECOME
QUITE GUSTY TODAY AS A BELT OF 25-35 KNOT WINDS AT 925MB CROSSES
THE LOWER LAKES DURING PEAK DAYTIME MIXING. THIS WILL ALLOW GUSTS
TO REACH 30-35 MPH AT THE SURFACE FROM THE NIAGARA FRONTIER
NORTHEAST TO KROC...WHICH IS THE FAVORED AREA FOR STRONGER
SOUTHWEST WINDS. THE STRONGEST WINDS WILL LIKELY BE FROM NEAR THE
BUF AIRPORT INTO THE EAST AND NORTHEAST SUBURBS AS THE FLOW
FOLLOWS ISENTROPIC SURFACES AND ESSENTIALLY DOWNSLOPES OFF THE
DOME OF COOLER/STABLE AIR OVER LAKE ERIE. THAT SAME DOME OF COOLER
MORE STABLE AIR WILL KEEP WINDS SOMEWHAT LIGHTER OVER LAKE ERIE
AND IN DOWNTOWN BUFFALO.
FOR TONIGHT...THE WINDS WILL DIMINISH QUICKLY THIS EVENING AS THE
BELT OF STRONGER 925MB WINDS WEAKENS AND DAYTIME MIXING ENDS. CLOUDS
WILL CONTINUE TO THICKEN AND INCREASE FROM NORTHWEST TO SOUTHEAST IN
ADVANCE OF THE WEAK FRONTAL BOUNDARY...WHICH WILL SAG SOUTH INTO THE
REGION AFTER 06Z SUNDAY. MODEST MID LEVEL HEIGHT FALLS AND PVA WILL
SUPPORT WEAK LARGE SCALE ASCENT...AND WEAK FRONTOGENESIS IN THE
850-700MB LAYER WILL SUPPORT SOME CONVERGENCE ALONG AND BEHIND THE
SURFACE COLD FRONT. ALL OF THIS WEAK FORCING MAY BE JUST ENOUGH TO
PRODUCE A FEW SCATTERED LIGHT SHOWERS LATE TONIGHT...MAINLY FROM THE
NIAGARA FRONTIER EAST TO ROCHESTER AND THE NORTH COUNTRY. AMOUNTS
WILL BE MINUSCULE GIVEN WEAK FORCING IN PLAY...WITH A FEW HUNDREDTHS
OF AN INCH IN SPOTTY LIGHT SHOWERS.
THE INCREASE IN CLOUD COVER AND SOME MIXING OVERNIGHT WILL KEEP LOWS
IN THE LOWER 50S ON THE LAKE PLAINS. SOME OF THE SHELTERED SOUTHERN
TIER VALLEYS WILL STILL DECOUPLE...AND CLOUDS WILL BE SLOWER TO
INCREASE THERE WHICH WILL ALLOW A FEW SPOTS TO RADIATE INTO THE MID
40S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
DURING THE COURSE OF SUNDAY...A WEAK COOL FRONT DRAPED ACROSS LAKES
ERIE AND ONTARIO AT THE START OF THE DAY WILL EVER SO SLOWLY SAG
SOUTH ACROSS THE CWA...WITH ITS SLOW PROGRESS DUE BOTH TO ITS NEAR
PARALLEL NATURE TO THE UPPER LEVEL FLOW...AND THE DEVELOPMENT OF A
WEAK WAVE OF LOW PRESSURE OVER THE TENNESSEE AND OHIO VALLEYS. THIS
FRONT WILL BE RELATIVELY STARVED FOR BOTH MOISTURE AND LIFT...SO FOR
MOST AREAS IT WILL ONLY BRING AN INCREASE IN CLOUD COVER AND A
LOW-END CHANCE FOR SOME LIGHT SHOWERS AND/OR SPRINKLES.
THE EXCEPTION TO THIS WILL COME LATER IN THE AFTERNOON ACROSS
THE SOUTHERN TIER AND INTERIOR SECTIONS OF THE FINGER LAKES...WHERE
THE FRONT WILL BEGIN TO INTERCEPT INCREASING AMOUNTS OF MOISTURE
LIFTING NORTHEAST FROM THE OHIO VALLEY...AND MAY ALSO ENCOUNTER SOME
LIMITED SURFACE-BASED INSTABILITY. THIS WILL RESULT IN A SOMEWHAT
HIGHER SHOWER POTENTIAL...AND ALSO THE POSSIBILITY OF A THUNDERSTORM
OR TWO. FOR THIS REASON...HAVE RAISED POPS TO HIGH CHANCE FOR THIS
LATTER AREA AND TIME FRAME...AND HAVE ALSO INSERTED A LOW CHANCE OF
SOME THUNDER.
BY SUNDAY EVENING...A CONSENSUS OF THE 00Z NAM/GFS/GEM/ECMWF HAS THE
SURFACE FRONTAL BOUNDARY TO BE DRAPED FROM WEST-CENTRAL PA
NORTHEASTWARD INTO CENTRAL AND EASTERN NEW YORK...WHERE IT WILL
LIKELY REMAIN IN PLACE THROUGH THE NIGHT AND MUCH OF MONDAY AS THE
AFOREMENTIONED WEAK WAVE OF LOW PRESSURE LIFTS NORTHEAST ALONG THE
BOUNDARY. INCREASING MOISTURE AND LIFT ASSOCIATED WITH THE PASSING
WAVE WILL RESULT IN AN INCREASING LIKELIHOOD OF SHOWERS ALONG THE
BOUNDARY...THOUGH THE BEST POTENTIAL FOR THESE STILL LOOKS TO LIE
JUST A LITTLE TO OUR EAST ACROSS CENTRAL AND EASTERN NY. FOR OUR
CWA...WILL INDICATE A GRADIENT IN POPS...WITH PRECIP CHANCES RANGING
FROM HIGH CHANCE ALONG OUR EASTERN PERIPHERY...TO LOW CHANCE OR EVEN
SLIGHT CHANCE ACROSS EXTREME FAR WESTERN NEW YORK AND THE SAINT
LAWRENCE VALLEY.
WITH THIS INITIAL SURFACE WAVE STILL LOOKING TO LARGELY PASS OFF TO
OUR EAST BY LATER MONDAY AFTERNOON OR EARLY MONDAY EVENING...HAVE
CONTINUED TO INDICATE A DOWNWARD TREND IN PRECIP CHANCES MONDAY
AFTERNOON...WITH JUST SOME LOW-END CHANCE POPS LINGERING ACROSS FAR
EASTERN SECTIONS BY EARLY MONDAY EVENING. AFTER THAT...HAVE PRETTY
MUCH HELD THESE PRECIP CHANCES IN PLACE RIGHT THROUGH MONDAY NIGHT
AS THE GFS/GEM/ECMWF ALL RIDGE A NARROW WEDGE OF HIGH PRESSURE
INTO FAR WESTERN NEW YORK...WHILE LIFTING A SECONDARY WAVE OF LOW
PRESSURE INTO CENTRAL AND EASTERN PA/NY.
DESPITE THE AFOREMENTIONED PRECIP CHANCES AND WHAT SHOULD BE
RELATIVELY CLOUDY CONDITIONS...TEMPS THROUGH THIS PERIOD WILL
AVERAGE CLOSE TO OR A LITTLE ABOVE AVERAGE AS A SEASONABLY MILD
AIRMASS REMAINS IN PLACE ACROSS THE LOWER GREAT LAKES. 850 MB TEMPS
WILL GENERALLY RANGE FROM +7C TO +8C WHICH WILL SUPPORTIVE OF HIGHS
IN THE UPPER 60S/LOWER 70S BOTH DAYS...WHILE NIGHTTIME LOWS FALL
INTO THE MID 40S TO LOWER 50S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ON TUESDAY...THE GFS/ECMWF ARE IN DECENT AGREEMENT THAT THE
SECONDARY LOW PRESSURE WAVE WILL PASS ACROSS CENTRAL AND EASTERN NEW
YORK...GENERALLY ALONG A PATH SIMILAR OR A LITTLE TO THE EAST OF ITS
PREDECESSOR SUNDAY NIGHT AND MONDAY. THIS SHOULD ONCE AGAIN KEEP THE
BULK OF ITS MORE WIDESPREAD SHOWER ACTIVITY TO THE EAST OF OUR
CWA...THOUGH WILL KEEP SOME LOW CHANCE POPS IN PLACE AS FAR WEST AS
THE GENESEE VALLEY TO COVER ITS PASSAGE. FURTHER TO THE WEST...FAR
WESTERN NEW YORK WILL LIKELY REMAIN DRY AS IT WILL BE SITUATED UNDER
NARROW SURFACE RIDGING BETWEEN THE AFOREMENTIONED COASTAL
SYSTEM...AND THE NEXT UPPER LEVEL TROUGH/SURFACE WAVE THAT WILL BE
IN THE PROCESS OF DIGGING INTO THE UPPER GREAT LAKES. THE SECONDARY
COASTAL WAVE WILL THEN LIFT OUT ACROSS NEW ENGLAND DURING THE COURSE
OF TUESDAY NIGHT...WITH LINGERING SHOWER CHANCES DIMINISHING ACROSS
CENTRAL AND EASTERN SECTIONS IN ITS WAKE.
THEREAFTER...THE MEDIUM RANGE GUIDANCE AGREES ON DIGGING THE
APPROACHING UPPER TROUGH/ASSOCIATED SURFACE REFLECTION ACROSS THE
LOWER LAKES REGION ON WEDNESDAY...WITH EXPANSIVE SURFACE-BASED
RIDGING THEN BUILDING ACROSS THE AREA IN ITS WAKE THURSDAY AND
FRIDAY ALONG WITH SLOWLY BUILDING HEIGHTS ALOFT. THIS WILL RESULT IN
THE CHANCE FOR SOME SCATTERED SHOWERS AND THUNDERSTORMS ON
WEDNESDAY...FOLLOWED BY A RETURN TO DRY WEATHER FOR BOTH THURSDAY
AND FRIDAY.
AS FOR TEMPERATURES...EXPECT SEASONABLE TO SLIGHTLY ABOVE AVERAGE
TEMPERATURES TO CONTINUE THROUGH TUESDAY AND WEDNESDAY WITH LITTLE
IN THE WAY OF AN AIRMASS CHANGE EXPECTED THROUGH THAT TIME. SOMEWHAT
COOLER TEMPS MAY THEN BRIEFLY RETURN FOR WEDNESDAY NIGHT AND
THURSDAY WITH THE PASSAGE OF THE UPPER TROUGH...BEFORE READINGS
RECOVER BACK TO SEASONABLE LEVELS ON FRIDAY UNDER THE BUILDING
RIDGING.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WILL PREVAIL FOR THE 15Z TAF CYCLE. HIGH PRESSURE
WILL DRIFT TO THE CAROLINA COAST TODAY AND PROVIDE CLEAR SKIES
THROUGH THE FIRST HALF OF THE DAY. MEANWHILE A WEAK COLD FRONT
OVER THE UPPER MIDWEST WILL MOVE INTO THE CENTRAL GREAT LAKES AND
BRING AN INCREASE IN MID/HIGH CLOUD FROM NORTHWEST TO SOUTHEAST
LATER THIS AFTERNOON AND EVENING.
IT WILL BECOME WINDY TODAY AS A BELT OF 30 KNOT WINDS JUST OFF THE
DECK CROSSES THE LOWER LAKES REGION...WITH MUCH OF THAT MIXING DOWN
THIS AFTERNOON WITH DAYTIME HEATING. THIS WILL BRING GUSTS IN THE
20-30 KNOT RANGE AT THE SURFACE...WITH THE STRONGEST WINDS EXPECTED
FROM KBUF-KIAG AREA OVER TO KROC. WINDS WILL QUICKLY DIMINISH THIS
EVENING AS WINDS ALOFT RELAX AND DAYTIME MIXING ENDS.
THE COLD FRONT WILL APPROACH LATE TONIGHT AND EARLY SUNDAY WITH MID
LEVEL CLOUDS THICKENING AND LOWERING. A FEW SCATTERED SHOWERS WILL
DEVELOP ALONG AND BEHIND THE SURFACE FRONT...AND A FEW OF THESE MAY
PUSH INTO KIAG-KBUF AND KART LATE TONIGHT...AND THE REMAINDER OF THE
AREA ON SUNDAY.
OUTLOOK...
SUNDAY...MAINLY VFR WITH A CHANCE OF SHOWERS. CHANCE OF A
THUNDERSTORM IN THE SOUTHERN TIER.
MONDAY...VFR/MVFR WITH A CHANCE OF SHOWERS.
TUESDAY...VFR WEST WITH VFR/MVFR EAST OF THE GENESEE VALLEY WITH A
CHANCE OF SHOWERS.
WEDNESDAY...MAINLY VFR WITH A CHANCE OF A FEW SHOWERS AND
THUNDERSTORMS.
&&
.MARINE...
SOUTHWEST WINDS WILL INCREASE INTO THE 10-15 KNOT RANGE TODAY AS THE
PRESSURE GRADIENT TIGHTENS BETWEEN DEPARTING HIGH PRESSURE OVER THE
CAROLINAS AND A WEAK COLD FRONT OVER THE UPPER GREAT LAKES. WINDS
MAY BRIEFLY EXCEED 15 KNOTS ON LAKE ERIE AND WESTERN LAKE ONTARIO
DURING THE MID TO LATE MORNING...BUT THE WARMER AIRMASS MOVING INTO
THE REGION TODAY SHOULD PROMOTE THE DEVELOPMENT OF A STABLE DOME OF
LAKE COOLED AIR OVER LAKES ERIE AND ONTARIO...WHICH TYPICALLY KEEPS
WINDS LIGHTER OVER THE LAKES THIS TIME OF YEAR. WITH THIS IN MIND...
WILL KEEP CONDITIONS BELOW SMALL CRAFT ADVISORY CRITERIA WITH WINDS
PEAKING AT A LITTLE OVER 15 KNOTS AND WAVES 2-3 FEET.
WINDS WILL BE VERY LIGHT ON SUNDAY AS A WEAK COLD FRONT SLOWLY SAGS
SOUTH ACROSS THE REGION AND WEAKENS THE PRESSURE GRADIENT. LIGHT
WINDS AND FLAT WAVE ACTION WILL CONTINUE THROUGH THE FIRST HALF OF
NEXT WEEK.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL/HITCHCOCK
MARINE...APFFEL/HITCHCOCK
EQUIPMENT...HITCHCOCK
AREA FORECAST DISCUSSION
NWS RALEIGH NC
930 PM EDT SUN MAY 13 2012
.SYNOPSIS...
A SURFACE LOW PRESSURE SYSTEM OVER THE GULF STATES WILL MOVE SLOWLY
ALONG THE APPALACHIANS THROUGH MIDWEEK. THE ASSOCIATED COLD FRONT
WILL MOVE VERY SLOWLY EASTWARD OVER THE CAROLINAS LATE MONDAY
THROUGH WEDNESDAY... RESULTING IN AN EXTENDED PERIOD OF UNSETTLED
WEATHER.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 925 PM SUNDAY...
FOR THE REST OF TONIGHT: THE MID LEVEL TROUGH AXIS EXTENDS FROM LAKE
HURON THROUGH INDIANA TO THE LOWER OH VALLEY AND MS THIS EVENING...
AND NUMEROUS MINOR PERTURBATIONS CONTINUE TO TRACK UP THE EAST SIDE
OF THE TROUGH THROUGH WRN/CENTRAL NC. THIS WEAK BUT PERSISTENT DPVA
AND A SUBTLE DISSIPATING POCKET OF UPPER DIVERGENCE AS WELL AS
DEEPENING AND STRENGTHENING ISENTROPIC UPGLIDE THROUGH 295K-310K
ACTING ON COPIOUS MOISTURE (PRECIPITABLE WATER HAS RISEN FROM JUST
BELOW NORMAL TO NEARLY 150% OF NORMAL SINCE THIS MORNING) HAS
PRODUCED WIDESPREAD LIGHT RAIN AND DRIZZLE OVER CENTRAL NC SINCE
LATE AFTERNOON... PARTICULARLY ON THE WESTERN PIEDMONT. THIS LIGHT
RAIN/DRIZZLE AREA... COINCIDENT WITH ONE PARTICULAR BETTER-DEFINED
MID LEVEL WAVE... WILL CONTINUE TO MOVE TOWARD THE NNE OVER THE NEXT
SEVERAL HOURS... AND WILL LIKELY BE FOLLOWED BY A BREAK IN STEADY
PRECIP FROM SSW TO NNE OVERNIGHT... AS NOTED ON THE HRRR MODEL WHICH
IS HANDLING THE CURRENT PRECIP WELL. BUT WITH STEADY ADVECTION IN
THE LOWEST 3 KM OF WARM AND VERY MOIST AIR... AND CONVERGENT FLOW AT
850 MB THROUGH THE CENTRAL CAROLINAS EVIDENT ON 00Z UPPER AIR
ANALYSES... THE CHANCES FOR MORE PRECIP OVERNIGHT ARE QUITE HIGH...
ESPECIALLY OVER THE WESTERN PIEDMONT GIVEN MODEL INDICATIONS OF
SUBSTANTIAL LOW LEVEL MOISTURE TRANSPORT CONTINUING IN THIS AREA
THROUGH DAYBREAK. NOT OVERLY CONCERNED ABOUT MUCH THUNDER TONIGHT
CONSIDERING THE LACK OF MID LEVEL HEIGHT FALLS AND WEAKENING UPPER
LEVEL WIND FIELD... PLUS THE DEEP LAYER SHEAR IS VERY WEAK AS ARE
THE LOW- AND MID-LEVEL LAPSE RATES. BUT CONSIDERING THE INCOMING
PUNCH OF MID LEVEL DRY AIR NOTED ON WATER VAPOR IMAGERY AND 00Z
SOUNDINGS FROM THE DEEP SOUTH AND WESTERN GULF COAST... POCKETS OF
BETTER (YET STILL VERY MODEST) DESTABILIZATION REMAIN POSSIBLE AND
THE RISK OF ISOLATED THUNDER WILL BE RETAINED OVERNIGHT. WITH THE
LIGHT NATURE OF THE PRECIP SO FAR AND EXPECTED SPOTTY NATURE OF
ADDITIONAL SHOWERS AND ISOLATED STORMS OVERNIGHT... HAVE CUT BACK
FORECAST PRECIP AMOUNTS THROUGH DAWN TO NO MORE THAN A THIRD OF AN
INCH WEST TO JUST A FEW HUNDREDTHS EAST... ALTHOUGH THE THREAT OF
HEAVIER RAIN ON MONDAY STILL APPEARS ON TRACK. EXPECT NEARLY STEADY
TEMPS IN THE 60-65 RANGE OVER MUCH OF THE AREA FOR THE REST OF THE
NIGHT. -GIH
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 235 PM SUNDAY...
MONDAY AND MONDAY NIGHT:
BROAD UPPER-LEVEL TROUGH IN PLACE FROM THE GREAT LAKES TO THE LOWER
MS VALLEY WILL GET REINFORCED BY SHORTWAVE TROUGH DIVING SOUTHEAST
ALONG THE SOUTHERN ROCKIES AND INTO THE SOUTHERN PLAINS ON MONDAY.
MEANWHILE...WEAK FRONTAL ZONE AND ASSOCIATED WAVE OF LOW PRESSURE
OVER THE SOUTHERN APPALACHIANS WILL INCH SLOWLY EASTWARD INTO THE
WESTERN CAROLINAS THROUGH MONDAY NIGHT. SHORTWAVE ENERGY IS EXPECTED
TO EJECT EAST-NORTHEASTWARD ACROSS THE AREA IN THE SWLY FLOW ALOFT
DOWNSTREAM OF THE BROAD TROUGH AND WITHIN THE ANOMALOUSLY HIGH (2
STD ABOVE NORMAL)PWAT AIRMASS LYING ALONG AND EAST OF THE WEAK
FRONTAL ZONE ACROSS WESTERN NC. DAYTIME HEATING OF THE MOIST
BOUNDARY LAYER WILL SUPPORT NUMEROUS TO WIDESPREAD SHOWERS/TSTMS
MONDAY AFTERNOON/EVENING...WITH AN AXIS OF MODERATE TO HEAVY RAINFALL
NOT BUDGING VERY MUCH...CENTERED ALONG AND ON THE EASTERN SLOPES OF
THE APPALACHIANS AND POTENTIALLY EXTENDING EAST INTO THE WESTERN
PIEDMONTS OF NC AND VIRGINIA. WHILE THERE REMAINS SOME UNCERTAINTY
WRT TO THE TIMING OF THE EMBEDDED SHORTWAVE IMPULSES...MODEL
CONSENSUS INDICATES THAT THE HEAVY RAINFALL AXIS AND HIGHEST WILL
SHIFT EASTWARD MONDAY NIGHT...REACHING THE COASTAL SECTIONS BY
DAYBREAK TUESDAY.
SEVERE WEATHER THREAT:
WHILE MOIST ADIABATIC PROFILES WILL SUPPORT WEAK MID-LEVEL LAPSE
RATES AND INSOLATION SHOULD BE GREATLY IMPEDED BY WIDESPREAD
CLOUDS...MODELS STILL SUGGEST THE POTENTIAL FOR WEAK TO MODERATE
DESTABILIZATION COULD DEVELOP MONDAY AFTERNOON. UNIDIRECTIONAL SWLY
FLOW OF 25-30 KT COULD SUPPORT A CLUSTER OR TWO OF STRONG TO SEVERE
THUNDERSTORMS THAT COULD PRODUCE DAMAGING WET MICROBURSTS. WITH LOSS
OF DAYTIME HEATING ...THE THREAT OF SEVERE WEATHER SHOULD BE ON THE
WANE MONDAY NIGHT AS THE AIRMASS COOLS/STABILIZES.
HEAVY RAIN THREAT:
WHILE IT WILL GREATLY DEPEND ON HOW MUCH RAINFALL WE SEE THIS
AFTERNOON AND TONIGHT...THE WESTERN PIEDMONT/TRIAD AREA COULD
POTENTIALLY ADD ANOTHER 1 TO 2 INCHES MONDAY AND MONDAY NIGHT TO
WHATEVER WE SEE TONIGHT. 3 HOUR FLASH FLOOD GUIDANCE TODAY FOR THOSE
AREAS ARE AROUND 3.0"...BUT IF WE RECEIVE AN INCH OF RAIN
TONIGHT...IT SHOULD LOWER THE GUIDANCE SIGNIFICANTLY...CLOSE TO THE
TWO INCH THRESHOLD. LATER SHIFTS MAY NEED TO CONSIDER A FLASH FLOOD
WATCH FOR THE WESTERN PIEDMONT MONDAY AFTERNOON/MONDAY NIGHT. EAST
OF THE TRIAD...EXPECT AVERAGE RAINFALL AMOUNTS OF 0.50-1.0"... WITH
ONLY LOCALIZED/URBAN FLOODING EXPECTED.
TEMPERATURES:
HIGHS MONDAY WILL DEPEND ON SHOWER/STORM COVERAGE AND WHETHER WE
WILL MANAGE TO SEE ANY BREAKS IN THE EAST. AFTERNOON HIGHS RANGING
FROM AROUND 70 WEST TO AROUND 80 EAST. LOWS MONDAY NIGHT AGAIN
IN THE 60S. -CBL
TUESDAY AND TUESDAY NIGHT:
ONGOING SHOWERS AND STORMS TUESDAY MORNING SHOULD BE MOVING INTO THE
COASTAL PLAIN AS THE AXIS OF DEEPEST MOISTURE FINALLY SHIFTS TOWARD
THE COAST. HOWEVER...THE WEAK SURFACE FRONT IS FORECAST LINGER BACK
TO THE WEST ALONG THE MOUNTAINS WHILE THE UPPER TROUGH ENERGY
CONTINUES TO EVOLVE WEST OF THE MOUNTAINS....EVENTUALLY PUSHING INTO
THE AREA TUESDAY EVENING. WITH SLIGHTLY DRIER AIR FORECAST TO
OVERSPREAD CENTRAL NC...SOME BREAKS IN CLOUD COVER AND STRONGER
DESTABILIZATION ARE EXPECTED. AHEAD OF THE UPPER TROUGH... THE MAY
CONTINUE TO BE SUBTLE DISTURBANCES ALOFT MOVING ACROSS THE
PERSISTENT WARM AND MOIST AIRMASS...LEADING TO A SCATTERED SHOWERS
AND STORMS BY TUESDAY AFTERNOON. THE NAM IS STRONGEST AND SHOWING A
STOUT VORT MAX LIFTING ACROSS THE AREA DURING PEAK HEATING. A
TIGHTER HEIGHT FIELD ASSOCIATED WITH THIS FEATURE LEADS TO STRONGER
DEEP LAYER SHEAR FORECAST BY THE NAM...BUT THE NAM SEEMS TO BE
OVERDONE. THE GFS AND ECMWF SHOW MORE A MORE DIFFUSE WAVE AND
ONLY 20-25KT OF 0-6KM BULK SHEAR...WHICH IS SUPPORTED BY MOST SREF
MEMBERS. THERE IS CONSIDERABLE SPREAD AMONG SREF MEMBERS REGARDING
INSTABILITY...BUT MODIFIED GFS SOUNDINGS FOR TEMPS IN THE UPPER 70S
TO LOWER 80S AND DEWPOINTS IN THE LOWER 60S SHOW 500-1000 J/KG OF
MLCAPE. A FEW ISOLATED SEVERE STORMS MAY BE POSSIBLE...BUT IF THE
UPPER WAVE IS STRONGER...AS THE NAM FORECASTS...THEN THE SEVERE
POTENTIAL WILL BE GREATER. HIGHS 77-82.
AS THE SURFACE FRONT AND MAIN LOW LEVEL CONVERGENCE ZONE PUSHES INTO
THE CWA TUESDAY EVENING...ISOLATED SHOWERS AND STORMS MAY CONTINUE
INTO THE OVERNIGHT HOURS. THE FRONT WILL CONTINUE TO BE RATHER SLOW
MOVING...AND LOWS SHOULD BE FAIRLY PERSISTENT IN THE UPPER 50S TO
LOWER 60S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 310 PM SUNDAY...
A SLOW MOVING...WEAK COLD FRONT IS FORECAST TO FINALLY MOVE INTO
CENTRAL NC BY WEDNESDAY MORNING...AS A POSITIVELY TITLED UPPER
TROUGH EXTENDING FROM THE GREAT LAKES INTO THE DEEP SOUTH BEGINS TO
DRIFT EAST ACROSS THE APPALACHIANS MOUNTAINS. DEEP MOISTURE WILL
BEGIN TO TREND DOWNWARD FROM WEST TO EAST AS THE TROUGH MOVES INTO
THE AREA...AND THUS POPS WILL BE INCREASINGLY FOCUSED OVER THE
EASTERN CWA WEDNESDAY AND THURSDAY. TEMPS SHOULD GENERALLY RUN
RIGHT AROUND NORMAL (HIGHS AROUND 80 AND LOWS IN THE MID TO UPPER
50S) IF NOT A SLIGHTLY BELOW NORMAL WITH WEAK TROUGHING ALONG THE
EAST COAST.
THEN...AS ENERGY SWINGING ACROSS THE GREAT LAKES LEAVES
THE SOUTHERN END OF THE UPPER TROUGH BEHIND...MODELS DIVERGE
REGARDING HOW THE TROUGH WILL EVOLVE AS IT DRIFTS EAST TOWARD THE
GA/SC COAST. THE 12Z GFS NEVER QUITE CLOSES OFF AN UPPER LOW AND
ALLOWS THE TROUGH TO BE SWEPT OFF TO THE NORTHEAST AS NORTHERN
STREAM ENERGY SWINGS ACROSS NEW ENGLAND. THE 00Z ECMWF HAD SHOWN A
VERY INTERESTING SOLUTION WITH THE UPPER LOW DEVELOPING ALONG THE
SOUTHEAST COAST AND A POSSIBLE SUBTROPICAL-LIKE LOW THAT DRIFTED
NORTHWEST INTO NC/SC OVER THE WEEKEND. THE 12Z ECMWF RUN SHOWS THE
UPPER LOW FURTHER OFFSHORE AND LITTLE IMPACT OVER NC. THERE IS A
LOT OF SPREAD AMONG GFS AND ECWMF ENSEMBLE MEMBERS...SO CONFIDENCE
IN SENSIBLE WEATHER IMPACTS NEXT WEEKEND IS LOW AT THE MOMENT....BUT
WE WILL KEEP THE FORECAST DRY FOR THIS PACKAGE.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 745 PM SUNDAY...
ADVERSE AVIATION CONDITIONS ARE EXPECTED TO PERSIST THROUGHOUT THE
CURRENT TAF PERIOD. A WEAK FRONT...WITH A WAVE OF LOW PRESSURE ALONG
IT...WILL CONTINUE TO PROGRESS EASTWARD TOWARDS THE REGION DURING
THE NEXT 24 HOURS. SEVERAL WEAK UPPER LEVEL DISTURBANCES IN THE
SOUTHWESTERLY FLOW ALOFT WILL COMBINE WITH WARM...MOIST FLOW AHEAD
OF THE AFOREMENTIONED FRONTAL SYSTEM TO PRODUCE PERIODS OF PRECIP
THROUGH THE PERIOD. THROUGH THE OVERNIGHT HOURS...THE BEST CHANCE OF
PRECIP WILL BE ACROSS THE WESTERN PORTION OF THE FORECAST AREA
(KINT/KGSO)...WITH ONLY SLIGHT CHANCES FURTHER EAST. MOST MODELS DO
INDICATE A LULL IN THE PRECIP AFTER 06Z...BEFORE PICKING UP AGAIN ON
MONDAY. NEVERTHELESS...CIGS WILL LOWER FROM WEST TO EAST OVER THE
NEST SEVERAL HOURS...WITH AN EXTENDED PERIOD OF SUB-VFR CONDITIONS
LIKELY FOR ALL TAF SITES. THEN...NUMEROUS TO WIDESPREAD SHOWERS AND
THUNDERSTORMS ARE EXPECTED ACROSS ALL OF CENTRAL NC MONDAY WITH
MVFR/IFR CONDITIONS IN HEAVY RAIN.
OUTLOOK...THE SHOWERS AND THUNDERSTORMS ARE EXPECTED TO PERSIST INTO
MONDAY NIGHT ACROSS THE REGION AS THE WEAK FRONT AND WAVE OF LOW
PRESSURE SLOWLY MOVES INTO WESTERN NC. THE FRONT WILL BE SLOW TO
MOVE EAST ACROSS CENTRAL NC TUESDAY AND INTO WEDNESDAY AND AS A
RESULT AM EXPECTING PERIODS OF IFR TO MVFR CONDITIONS WITH SCATTERED
SHOWERS AND THUNDERSTORMS. DRIER AIR SHOULD GRADUALLY FILTER INTO
THE AREA FROM THE WEST ON THURSDAY...LEADING TO DRIER CONDITIONS FOR
THE REMAINDER OF THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SEC/GIH
NEAR TERM...HARTFIELD
SHORT TERM...CBL/BLS
LONG TERM...BLS
AVIATION...KRR/CBL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
757 PM EDT SUN MAY 13 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM APPROACHING FROM THE SOUTHWEST WILL BRING
INCREASING RAIN CHANCES THIS AFTERNOON AND TONIGHT. A COLD FRONT
WILL STALL NEAR THE AREA THROUGH MID WEEK BRINGING CONTINUED
CHANCES FOR SHOWERS AND THUNDERSTORMS...WITH SIGNIFICANT RAINFALL
POSSIBLE MONDAY INTO TUESDAY. COLD FRONT PUSHES OFFSHORE THURSDAY
BRINGING DRIER CONDITIONS FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 2 PM SUNDAY...SHOWERS REMAIN SCATTERED MAINLY OVER SOUTH
CAROLINA THIS AFTERNOON WHERE RICHER DEWPOINT AIR EXISTS WITH
READINGS IN THE MID 60S. DRIER AIR STILL EXISTS FROM CAPE FEAR
NORTH CLOSER TO THE COAST WHERE DEWPOINT TEMPS WERE IN THE MID
50S. HIGHER HRRR CAPE VALUES ALIGNING NICELY WITH SHWR DEVELOPMENT
OVER SC AND INLAND NC ZONES. CLOUD COVER MODERATING TEMPS
OVERALL...ESPECIALLY WHERE PCP OCCURRED THROUGH THE DAY.
MODELS STILL SHOWING SHWR DEVELOPMENT AREA SHIFTING FARTHER INLAND
OVER SC MAINLY THROUGH LATE AFTERNOON WHILE COASTAL NC BECOMES
SLIGHTLY DRIER. MAIN AREA OF PCP MOVING UP THROUGH GA AND SC
AHEAD OF LOW TRACKING NORTH THROUGH TENNESSEE THROUGH TONIGHT.
DEEPEST LAYER MOISTURE WILL REMAIN OVER INLAND SOUTH CAROLINA
TRACKING INTO NC. PCP WATER VALUES WILL REACH UP AROUND 1.5 INCHES
INLAND WHILE STILL REMAINING QUITE DRY FROM CAPE FEAR NORTHWARD
WHERE PCP WATER VALUES REMAIN LESS THAN AN INCH CLOSER TO THE COAST.
EXPECT MOST OF THE SHWR ACTIVITY TO REMAIN SOUTH AND WEST OF CWA
WITH LESS IN THE WAY OF PCP ACROSS COASTAL NC THROUGH MUCH OF
TONIGHT. MOISTURE PROFILES OVER LOCAL AREA SHOWING MOISTURE
THINNING OUT THROUGH THE COLUMN IN THE MID LAYERS THROUGH THIS
EVENING. CAN NOT RULE OUT SOME SHWRS AS SHORTWAVE ROTATES AROUND
PROVIDING SOME MINOR PERTURBATIONS TO SUPPORT SOME CONVECTIVE
DEVELOPMENT BUT OVERALL EXPECT MORE ISOLATED THROUGH THIS EVENING
WITH BETTER CONVECTIVE DEVELOPMENT POSSIBLE LATER TONIGHT ACROSS
THE PEE DEE REGION IN SOUTH CAROLINA AND ALSO ACROSS THE COASTAL
WATERS.
TEMPS WILL ONLY DROP INTO THE LOWER 60S MOST PLACES OVERNIGHT WITH
PLENTY OF MOISTURE PRESENT AND CONSIDERABLE CLOUD COVER.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 340 PM SUNDAY...SFC HIGH PRESSURE TO RETREAT FARTHER OFFSHORE
MONDAY. THIS WILL ALLOW A SFC COLD FRONT ALBEIT WEAK...TO TRACK TO
THE WESTERN CAROLINAS FROM THE GULF COAST STATES BY TUESDAY. THIS
WILL OPEN UP BOTH THE GULF OF MEXICO AND ATLANTIC MOISTURE FEEDS
ACROSS THE FA BY MIDDAY MONDAY...AND CONTINUE THROUGH TUESDAY NIGHT.
THE BEST SHOT FOR POPS FROM CONVECTION WILL RUN FROM MONDAY
AFTERNOON THROUGH DAYBREAK TUESDAY. MID-LEVEL IMPULSES ARE PROGGED
TO WEAKEN AS THEY REACH AND TRACK ACROSS THE FA...NEVERTHELESS THIS
WILL CONTINUE TO BE A FOCUS FOR CONVECTION DEVELOPMENT. PROGGED
NAMBUFR SOUNDINGS INDICATE A NEARLY SATURATED ATM COLUMN ACROSS THE
FA WITH 1.5 TO 1.9 PWS MONDAY NIGHT. COULD OBSERVE WIDESPREAD 3/4 TO
1 1/4 INCHES OF RAINFALL ACROSS THE REGION THROUGH TUESDAY DAYBREAK.
THE DRY GROUNDS AND VEGETATION ACROSS THE REGION WILL ACT LIKE
SPONGES. HOWEVER WILL STILL CONTINUE TO INDICATE IN THE HWO ABOUT
THE POSSIBILITY OF FLOODING RAINS ACROSS ISOLATED LOCALES THAT COULD
EXPERIENCE UP TO 2 INCHES OF RAINFALL. FOR TUESDAY...DIURNALLY
DRIVEN CONVECTION WILL TAKE OVER WITH THE AID OF THE NEARLY STALLED
SFC COLD FRONT AS A TRIGGER. UPPER LEVEL IMPULSES NOT AS PRONOUNCED
THAT WILL AFFECT THE FA LATE MONDAY INTO MONDAY NIGHT. MAX/MIN TEMPS
WILL HOVER WITHIN 3 DEGREES ON EITHER SIDE OF THE CLIMO NORMS.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 340 PM SUNDAY...EARLY PORTION OF THE FORECAST IS FAIRLY
STRAIGHT FORWARD. BROAD TROUGHING ALOFT...WITH THE AXIS WEST OF THE
AREA...RESULTS IN DEEP SOUTHWEST FLOW PARALLEL TO SURFACE BOUNDARIES
STALLED IN THE AREA. TYPICALLY THIS YIELDS UNSETTLED...THOUGH NOT
VERY WIDESPREAD...WEATHER. WILL BUMP POP A BIT HIGHER WED BUT STILL
IN THE CHC RANGE AT THIS POINT. TIMING ANY POTENTIAL SHORTWAVES THAT
COULD ENHANCE STORMS AND CREATE MORE COVERAGE AT THIS POINT IS
DIFFICULT AT BEST SO FURTHER POPS REFINEMENTS...BOTH SPATIAL AND
TEMPORAL...WILL BE NEEDED. POTENT SHORTWAVE OUT OF THE WEST HELPS
PUSH THE UPPER TROUGH AND THE STALLED FRONT OFFSHORE WED NIGHT INTO
THU. MOISTURE AND THE THREAT OF PRECIP LINGERS INTO THU WITH TROUGH
AXIS/UPPER LOW OVER HEAD AND SLOW TO MOVE EAST. AT THIS POINT THE
ECMWF/HPC SOLUTION DIFFERS FROM THE GFS/CANADIAN SOLUTION.
00Z ECMWF AND HPC SOLUTIONS DIG THE UPPER TROUGH A BIT DEEPER OVER
THE NORTHERN GOMEX WHICH RESULTS IN A SEMI-CUTOFF UPPER LOW OVER
OVER GA/NORTHERN FL. THIS INDUCES A SURFACE LOW WHICH STARTS OUT
COLD CORE BUT COULD BECOME A HYBRID SYSTEM AS IT MOVES NORTH ALONG
THE COAST. THE 12Z GFS/CANADIAN SOLUTIONS AND A NUMBER OF THE GFS
ENSEMBLE MEMBERS SUPPORT LESS AMPLIFICATION OF THE 5H TROUGH OVER
THE NORTHERN GOMEX...WHICH RESULTS IN THE SYSTEM DEVELOPING MUCH
FARTHER OFF THE COAST. GIVEN BOTH SOLUTIONS SHOW A SYSTEM DEVELOPING
HAVE HIGH CONFIDENCE SOMETHING WILL EXIST OFF THE COAST LATE IN THE
PERIOD...BUT DETAILS REMAIN FUZZY. LOW CONFIDENCE AND THE POTENTIAL
FOR FORECAST FLIP-FLOPPING WILL NOT MAKE MUCH IN THE WAY OF CHANGES
BEYOND THU...KEEPING INHERITED SLIGHT CHC POP. TEMPERATURES WILL BE
WITHIN A DEGREE OR TWO OF CLIMO THROUGH THE PERIOD.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 00Z...PERIODS OF MVFR WILL CONTINUE THROUGH THE OVERNIGHT
HOURS DUE TO CIGS/BRIEF FOG/ISOLATED RAINFALL...WITH MVFR BECOMING
MORE CONSISTENT AFTER DAYBREAK AS LOWERED CIGS AND SHOWERS MOVE
IN...WITH TSRA POSSIBLE. CANNOT RULE OUT BRIEF PERIODS OF IFR WITH
HEAVIER SHOWERS AND/OR THUNDERSTORMS. OTHERWISE EXPECT VFR.
CURRENT RADAR AND 11-3.9U SATELLITE IMAGERY SHOW ABUNDANT CLOUD
COVER ACROSS THE AREA WITH ISOLATED LIGHT SHOWERS INLAND...ALL AHEAD
OF A LOW PRESSURE SYSTEM TO THE SOUTHWEST. ANTICIPATE ANY LINGERING
LIGHT RAIN TO TAPER OFF WITHIN THE NEXT HOUR OR TWO...WITH PERIODS
OF MVFR EXPECTED. HAVE INTRODUCED MVFR FOG AT KFLO FOR POSSIBLE
ADVECTION FOG. WINDS OVERNIGHT WILL BE LIGHT AND VARIABLE. AFTER
SUNRISE...LOW LEVEL CLOUDS WILL INCREASE IN OPACITY AND RAIN WILL
FILL IN ACROSS THE AREA. AS AFOREMENTIONED...CANNOT RULE OUT BRIEF
PERIODS OF IFR WITH HEAVIER SHOWERS AND/OR THUNDERSTORMS THROUGHOUT
THE DAY. SOUTH-SOUTHEAST WINDS AOB 10 KTS THROUGHOUT THE MORNING
WILL INCREASE THROUGHOUT THE AFTERNOON...WITH GUSTS NEAR 20 KTS
POSSIBLE. CHANCES FOR TSRA WILL INCREASE INTO EARLY
AFTERNOON...THOUGH CONFIDENCE IS LOWERED GIVEN WEAK ANTICIPATED
INSTABILITY.
EXTENDED OUTLOOK...UNSETTLED WEATHER THROUGH THE PERIOD WITH A GOOD
CHANCE FOR SHOWERS/ISOLATED THUNDERSTORMS EACH DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM SUNDAY...LATEST BUOY OBS SHOWING SEAS 2 TO 3 FT THIS
MORNING BUT UP TO 4 FT JUST SOUTH AND EAST OF LOCAL WATERS. SOUTHEAST
WINDS UP AROUND 15 KTS WILL CONTINUE AS GRADIENT TIGHTENS BETWEEN
DEVELOPING LOW PRESSURE OVER TENNESSEE AND HIGH PRESSURE WELL OFF
THE NORTH CAROLINA COAST. WINDS WILL VEER SLIGHTLY THROUGH TONIGHT
BECOMING MORE NORTHERLY AS LOW TRACKS FARTHER NORTH AND EAST. THIS
PERSISTENT ON SHORE FLOW THROUGH TONIGHT WILL BUILD SEAS UP TO 3
TO 4 FT WITH SOME 5 FTERS IN OUTER WATERS.
THE BEST CHANCE OF SHOWER ACTIVITY WILL REMAIN ACROSS THE SC
WATERS...REMAINING ISOLATED THROUGH MOST OF THE NIGHT WITH
POSSIBLE REDEVELOPMENT LATER TONIGHT.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 350 PM SUNDAY...HIGH PRESSURE TO RETREAT FURTHER OFFSHORE AND
THE HIGH SEAS THROUGH THE PERIOD. SFC COLD FRONT TO SLOWLY PUSH TO
THE WATERS BY THE END OF THE PERIOD. THIS OPENS UP A SSE TO SSW WIND
DIRECTION MONDAY INTO TUESDAY. THE TIGHTENED SFC PG WILL OCCUR
MONDAY INTO EARLY TUESDAY...BEFORE RELAXING AS THE FRONTAL BOUNDARY
TURTLES ITS WAY EASTWARD BEFORE STALLING JUST INLAND FROM THE COAST
BY EARLY WEDNESDAY. WINDS WILL BE AT THEIR PEAK LATE MONDAY INTO
MONDAY NIGHT...WITH SPEEDS 15 TO 20 KT. AN ESE GROUND SWELL AT 7-8
SECOND PERIODS WILL COMBINE WITH LOCALLY PRODUCED 3 TO 5 SECOND
PERIOD WIND WAVES...TO PRODUCE 3 TO 5 FT SEAS. A FEW 6 FOOTERS
REMAIN POSSIBLE ESPECIALLY THE OUTER WATERS OFF CAPE FEAR AND CAPE
ROMAIN. THE TIME FRAME FOR THIS OCCURRENCE...MONDAY AFTERNOON INTO
TUESDAY NIGHT. NOT ALL THAT CONVINCED THAT SCA CRITERIA WILL BE MET
FOR ANY LENGTH OF TIME. HOWEVER SCEC THRESHOLDS WILL BE MET AND
LIKELY RAISED TONIGHT OR MONDAY UNLESS FUTURE MODEL RUNS INDICATE
INCREASED OCCURRENCE FOR SCA CRITERIA.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 340 PM SUNDAY...SOUTHWEST FLOW OVER THE WATERS WED WITH FRONT
STALLED VERY CLOSE TO THE COAST. PROXIMITY TO THE BOUNDARY WILL KEEP
SOUTHWEST FLOW 10 KT OR LESS ALL DAY. FRONT IS PUSHED OFF THE COAST
LATE WED NIGHT INTO THU WITH WINDS VEERING FROM NORTHWEST
IMMEDIATELY BEHIND THE FRONT TO NORTHEAST BY MID TO LATE MORNING
THU. OFFSHORE FLOW STARTS OUT AROUND 10 KT BUT COLD SURGE LATE THU
NIGHT WILL PUSH SPEEDS CLOSE TO 15 KT AWAY FROM SHORE. FRI COULD BE
QUITE INTERESTING IF THE 00Z ECMWF/HPC SOLUTION VERIFIES. THESE
SOLUTIONS BRING LOW PRESSURE...POTENTIALLY A TROPICAL HYBRID...INTO
THE COASTAL WATERS LATE FRI AND KEEPS IT IN THE AREA SAT. AT THIS
POINT THE EVENT LOOKS LIKE IT WOULD BE A SOLID SCA EVENT...AGAIN IN
THE 00Z ECMWF/HPC SOLUTION VERIFIES. THE 12Z GFS/CANADIAN HAS THE
LOW MUCH FARTHER OFF THE COAST WITH CONTINUED SOLID 15 KT NORTHEAST
FLOW SAT AND SUN. FOR NOW HAVE CONTINUED NORTHEAST FLOW THROUGH THE
END OF THE PERIOD WITH FURTHER ADJUSTMENTS EXPECTED AS THE CORRECT
SOLUTION BECOMES MORE DEFINED.
SEAS 2 TO 4 FT WITH SOME SWAN SUGGESTING A BIT OF SOUTHERLY SWELL
STARTING TO DEVELOP WED. PASSAGE OF COLD FRONT AND RESULTING
NORTHERLY FLOW WILL CREATE CHAOTIC 2 TO 4 FT SEAS WED NIGHT AND THU.
COLD SURGE THU NIGHT WILL INCREASE SEAS FRI...3 TO 4 FT EXCEPT FOR
AREAS BLOCKED TO NORTHEAST FLOW WHERE SEAS WILL BE 1 TO 2 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ
SHORT TERM...DCH
LONG TERM...III
AVIATION...SGL
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
655 PM CDT SUN MAY 13 2012
.AVIATION...
FOR THE 00Z TAFS...ONGOING SHOWERS AND THUNDERSTORMS CONTINUE TO
IMPACT THE KAMA TERMINAL WHERE MODERATE TO HEAVY RAIN HAS REDUCED
VISBYS DOWN TO BELOW 2 MILES BRIEFLY. CURRENT RADAR IMAGERY SHOWS
STORMS SLOWLY MOVING EAST...SO EXPECT TSRA TO IMPACT KAMA THROUGH
01Z. HAVE INSERTED A TEMPO GROUP WITH MVFR VISBYS AT 2SM THROUGH THEN
AS ADDITIONAL HEAVY RAINFALL CAN ACCOMPANY THESE STORMS. KDHT IS
CURRENTLY REPORTING MVFR VISBYS IN LIGHT FOG WHICH SHOULD CONTINUE
THIS EVENING. STORMS CONTINUE TO DEVELOP ACROSS THE EASTERN PLAINS
0F CO/NM AS UPPER LIFT PROVIDED BY AN UPPER SHORTWAVE TROUGH IN THE
FOUR CORNERS AREA COMBINES WITH MOIST LOW-LEVEL UPSLOPE FLOW. HAVE
CARRIED -SHRA TONIGHT AT THE TERMINALS AS THESE SHOWERS WILL
CONTINUE TO MOVE TO THE EAST. OUTSIDE OF ANY STRONGER SHOWER THAT MAY
PRODUCE MODERATE OR HEAVY RAINFALL THAT CAN REDUCE BRIEFLY REDUCE
VISBYS...EXPECT VFR CONDITIONS THROUGH THE TAF FORECAST PERIOD. THE
UPPER SHORTWAVE TROUGH IS EXPECTED TO CONTINUE TO DROP SOUTH AND MOVE
INTO WEST TX BY MONDAY AFTERNOON. THUS EXPECT -SHRA MONDAY MORNING
AND AFTERNOON WITH SKIES THINNING TOWARD THE END OF THE FORECAST
PERIOD...PARTICULARLY AT KGUY/KDHT.
CLK
&&
.PREV DISCUSSION... /ISSUED 332 PM CDT SUN MAY 13 2012/
DISCUSSION...
PRIMARY FOCUS IS ON PRECIPITATION CHANCES THROUGH MONDAY.
AFTERNOON WATER VAPOR IMAGERY SHOWED A MID/UPPER-LEVEL SHORTWAVE
TROUGH SINKING SOUTHEAST ACROSS EASTERN UT TOWARDS THE FOUR CORNERS
REGION. MID TO UPPER-LEVEL FORCING AHEAD OF THIS SHORTWAVE HAS
COMBINED WITH DAYTIME HEATING/DESTABILIZATION AND LOW-LEVEL UPSLOPE
FLOW OVER EASTERN CO AND NM TO GENERATE SHOWERS AND THUNDERSTORMS.
THE GREATEST CONVECTIVE COVERAGE IS CURRENTLY ACROSS NORTHEAST NM
WORKING INTO THE SOUTHWEST TX PANHANDLE...BUT ADDITIONAL SCATTERED
SHOWERS AND THUNDERSTORMS HAVE DEVELOPED FARTHER EAST ACROSS THE
PANHANDLES DUE TO THE COMBINATION OF AFTERNOON DESTABILIZATION AND
BROADER SCALE LIFT AHEAD OF THE SHORTWAVE.
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO IMPACT THE AREA THIS
EVENING AND OVERNIGHT. THE MID/UPPER-LEVEL SHORTWAVE TROUGH WILL
CONTINUE TO DIVE SOUTHEAST...REACHING NORTHERN/CENTRAL NM BY EARLY
MONDAY MORNING. DIFFLUENT/DIVERGENT FLOW ALOFT AHEAD OF THIS WAVE
WILL CONTINUE TO SUPPORT CONVECTION PROPAGATING EAST/SOUTHEAST OUT OF
NM AND CO THIS EVENING AND OVERNIGHT. BEST DYNAMICS WILL BE FOCUSED
ACROSS THE SOUTHWEST HALF OF THE AREA AND HAVE ALIGNED POPS
ACCORDINGLY. ALSO SOME WEAK ISENTROPIC LIFT EVIDENT ON THE 305K THETA
SURFACE ACROSS THE SOUTHWEST TX PANHANDLE THIS EVENING TO FURTHER AID
CONVECTION. LATEST LAPS AND RUC ANALYSIS DATA SHOW MLCAPES IN THE
500-1000 J/KG RANGE ACROSS THE WESTERN PANHANDLES WITH LESSER VALUES
TO THE EAST AND DEEP LAYER SHEAR AROUND 30-35 KTS IN THE SOUTHWEST
TX PANHANDLE...DECREASING TO THE NORTHEAST. THUS COULD SEE A FEW
STRONG STORMS THROUGH THIS EVENING CAPABLE OF PRODUCING SMALL HAIL
AND GUSTY WINDS...BUT NOT REALLY ANTICIPATING ANY SEVERE WEATHER
/ALTHOUGH AN ISOLATED MARGINALLY SEVERE STORM ACROSS THE SOUTHWEST CAN/T
BE RULED OUT/. COULD ALSO SEE SOME LOCALLY HEAVY RAIN GIVEN PWATS IN
THE THREE QUARTERS OF AN INCH TO ONE INCH RANGE AND SOME TRAINING OF
STORMS POSSIBLE. BETTER RAIN CHANCES LOOK TO GRADUALLY SHIFT
SOUTH/SOUTHWEST OF THE AREA LATE TONIGHT IN ASSOCIATION WITH STRONGER
DIVERGENCE ALOFT...AND ALSO AS THE LLJ AND LOW-LEVEL ISENTROPIC LIFT
FOCUS TO OUR SOUTHWEST.
RAIN CHANCES LINGER INTO MONDAY...BUT WILL GRADUALLY END FROM NORTH
TO SOUTH THROUGH THE DAY AS THE SHORTWAVE CONTINUES TO DIVE SOUTHEAST
TO SOUTHEAST NM/SOUTHWEST TX BY EARLY MONDAY EVENING. BETTER RAIN
CHANCES WILL BE FOCUSED ACROSS THE SOUTHERN HALF OF THE CWA ON
MONDAY. WEAKER INSTABILITY AND SHEAR SHOULD PRECLUDE ANY STRONG OR
SEVERE STORMS. WILL ALSO SEE THE COOLEST TEMPS IN THE SOUTH ON MONDAY
DUE TO LINGERING CLOUDS/PRECIP...WITH HIGHS FORECAST TO RANGE FROM
THE UPPER 60S SOUTHWEST TO MID/UPPER 70S NORTH.
DRY CONDITIONS ARE THEN FORECAST BEGINNING MONDAY NIGHT AS SHORTWAVE
UPPER RIDGING BUILDS EAST ACROSS THE SOUTHERN AND CENTRAL ROCKIES.
TEMPS WILL BEGIN TO REBOUND ON TUESDAY DUE TO RISING HEIGHTS...A
RETURN OF WEAK SOUTHERLY WINDS...AND INCREASED SUNSHINE...WITH HIGHS
CLIMBING BACK INTO THE UPPER 70S TO LOWER 80S. A DAMPENING MID-LEVEL
SHORTWAVE WILL WORK ACROSS THE CENTRAL ROCKIES AND PLAINS WEDNESDAY
AND WEDNESDAY NIGHT. THIS COULD POTENTIALLY SPAWN A FEW
SHOWERS/THUNDERSTORMS ACROSS THE NORTHERN PANHANDLES WEDNESDAY NIGHT.
HOWEVER...CHANCES LOOK LOW AT THIS TIME AS BETTER DYNAMICS WILL STAY
TO OUR NORTH AND COME ACROSS AT NIGHT...BY WHICH TIME ELEVATED
INSTABILITY LOOKS MINIMAL. THUS KEPT A DRY FORECAST FOR NOW. THE LEE
TROUGH WILL DEEPEN ON WEDNESDAY...WITH RESULTANT BREEZY SOUTHWEST
WINDS FURTHER CONTRIBUTING TO THE WARM UP.
A ZONAL FLOW/BROAD FLAT RIDGING LATE THIS WEAK WILL TRANSITION TO
SOUTHWESTERLY OVER THE WEEKEND AS AN UPPER TROUGH WORKS ACROSS THE
INTERMOUNTAIN WEST AND ROCKIES EVENTUALLY INTO THE NORTHERN PLAINS.
THIS FLOW ALOFT WILL PROMOTE SURFACE LEE TROUGHING AND SOME
SHARPENING OF THE DRYLINE BY FRIDAY AND SATURDAY. HOWEVER IT
CURRENTLY LOOKS LIKE WARM TEMPS ALOFT AND A LACK OF UPPER FORCING /AS
THE TROUGH IS DEFLECTED WELL TO OUR NORTHWEST/ WILL MAKE IT TOUGH FOR
CONVECTION TO INITIATE. THUS WILL MAINTAIN A DRY FORECAST. ABOVE
NORMAL TEMPERATURES EXPECTED LATE WEEK INTO THE WEEKEND WITH HIGHS IN
THE MID 80S TO LOWER 90S. WILL HAVE TO KEEP AN EYE ON A POTENTIAL
COLD FRONT THAT MAY MOVE IN SUNDAY OR SUNDAY NIGHT.
KB
FIRE WEATHER...
NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE CURRENTLY
EXPECTED THROUGH THE WEEK. SOUTH/SOUTHWEST WINDS WILL INCREASE TO 15
TO 20 MPH ON WEDNESDAY AND RELATIVE HUMIDITIES MAY FALL TO 15 TO 20
PERCENT ACROSS THE FAR WESTERN PANHANDLES...BUT RECENT RAINFALL AND
RESULTANT GREEN-UP SHOULD MITIGATE ANY FIRE WEATHER CONCERNS. WARMER
TEMPERATURES WILL CONTINUE LATE WEEK INTO THE WEEKEND AND MINIMUM
RELATIVE HUMIDITIES WILL FALL TO 15 TO 20 PERCENT ACROSS WESTERN
AREAS. SOUTH/SOUTHWEST WINDS WILL BE BREEZY AT TIMES AND ELEVATED
FIRE WEATHER CONDITIONS COULD DEVELOP...BUT AGAIN RECENT RAINFALL AND
GREEN-UP WILL HELP MINIMIZE FIRE WEATHER CONCERNS.
KB
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
05/15
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
120 AM EDT SAT MAY 12 2012
.SYNOPSIS...
HIGH PRESSURE WILL SLIDE EAST ACROSS THE REGION TONIGHT BEFORE
PASSING OFFSHORE ON SATURDAY. RETURN SOUTHERLY FLOW AROUND THE
HIGH WILL BRING INCREASING MOISTURE BACK TO THE AREA LATE SATURDAY
THROUGH SUNDAY. A COLD FRONT WILL DRIFT EAST ACROSS THE REGION
SUNDAY NIGHT INTO MONDAY...POSSIBLY RESULTING IN MORE WIDESPREAD
SIGNIFICANT RAINFALL INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1115 PM EDT FRIDAY...
HIGH CLOUDS FANNING OUT AHEAD OF THE DEEPER MOISTURE AXIS TO THE
WEST SHOULD REMAIN QUITE THIN OVERNIGHT GIVEN DRY AIR IN PLACE PER
EVENING RAOBS AND SUBSIDENCE UNDER HIGH PRESSURE. THEREFORE ONLY
MADE SOME SMALL UPWARD TWEAKS TO SKY COVER MAINLY OVER THE WEST
LATE TONIGHT WHEN THE MORE AGGRESSIVE NAM SHOWS A THICKER CANOPY
ARRIVING BY DAYBREAK. OTRW GOING CLEAR TO MOSTLY CLEAR FORECAST ON
TRACK WITH THE BETTER MOISTURE ADVECTION NOT ARRIVING UNTIL LATER
SATURDAY. SHOULD BE ANOTHER RATHER COOL OVERNIGHT PER LOW
DEWPOINTS AND LIGHT WINDS UNDER HIGH PRESSURE PROVIDING GOOD
RADIATIONAL COOLING DESPITE SOME HIGH CLOUDS. LOOKS LIKE SPOTTY 30S
AGAIN VALLEYS WITH SOME PATCHY FROST POSSIBLE MAINLY FAR NW BUT
NOT ENOUGH FOR AN ADVISORY GIVEN BRIEF NATURE AT THIS POINT. OTRW
APPEARS SHOULD SEE MOST OTHER LOCATIONS IN THE 40S BY MORNING SO
BUMPED DOWN LOWS A LITTLE.
PREVIOUS DISCUSSION AS OF 250 PM EDT FRIDAY...
UPPER RIDGE/SFC HIGH PRESSURE WILL SETTLE OVERHEAD TONIGHT.
EXPECT GOOD RADIATIONAL COOLING CONDITIONS UNDER CLEAR SKIES AND
LIGHT WINDS. LOWS WILL RANGE FROM THE UPPER 30S IN THE COLDER VALLEY
TO THE MID 40S IN THE SOUTH.
MOISTURE SLOWLY INCREASES ON SATURDAY AS SURFACE LOW PRESSURE MOVES
INTO THE LOWER MISSISSIPPI VALLEY. WITH POOLING OF MOISTURE AND
UPSLOPE FLOW...ALLOWED FOR SOME LIGHT SHOWERS IN THE SOUTHWEST
MOUNTAINS SATURDAY AFTERNOON. PLAYED HIGH TEMPERATURES SATURDAY
AFTERNOON FROM THE UPPER 60S IN THE MOUNTAINS TO THE MID 70S IN THE
SOUTHEAST.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 230 PM EDT FRIDAY...
DETERIORATING WEATHER CONDITIONS EXPECTED DURING THE SHORT TERM
PERIOD OF THE FORECAST...AS ENERGY FROM SOUTHERN STREAM LOW ACROSS
TEXAS TODAY MERGES WITH A NORTHERN STREAM WAVE MOVING THROUGH THE
GREAT LAKES.
THE FIRST FORECAST CONCERN IS WHEN PRECIP DEVELOPS. THE GFS MOISTENS
THE AIR MASS QUICKLY...INCREASING PWATS TO OVER AN INCH OVER MUCH OF
THE FORECAST AREA BY SUNDAY MORNING. THE NAM IS MUCH SLOWER...BUT
WAS DISREGARDED. WITH THE LOW LEVEL THETA-E RIDGE SNEAKING UP THE
FAR WESTERN PORTION OF THE FORECAST AREA...COMBINED WITH ISENTROPIC
LIFT...KEPT SMALL POPS ACROSS THE FAR WESTERN PORTION OF THE
FORECAST AREA.
ON SUNDAY...WEAK SHORT WAVES BEGIN TO INVADE THE AREA FROM THE
SOUTHWEST IN A DEEP SOUTHWEST FLOW. MOST OF THE PRECIPITATION
SHOULD REMAIN IN THE WESTERN HALF OF THE FORECAST AREA UNDER THE
THETA-E RIDGE.
PRECIP SHOULD EXPAND EAST OF THE BLUE RIDGE BY LATE SUNDAY NIGHT AND
ESPECIALLY MONDAY AS THE SFC COLD FRONT APPROACHES AND LOW LEVEL
WINDS BACK...INCREASING LOW LEVEL CONVERGENCE. PLUS A BROAD AREA OF
UPPER DIVERGENCE FORMS AS OUR FORECAST AREA FALLS UNDER THE RR QUAD
OF NORTHERN STREAM JET.
THIS SPELLS THE POTENTIAL FOR A HEAVY RAIN EVENT ON MONDAY..AS
PWATS INCREASE TO GREATER THAN 2 STANDARD DEVIATIONS ABOVE NORMAL ON
MONDAY...AND WITH GEFS...AND TO LESSER EXTENT...NAEFS HYDROLOGIC
ENSEMBLES SHOWING A SMALL CHANCE SOME RIVER GAUGE LOCATIONS
EXCEEDING ACTION STAGE. THEREFORE...WILL INTRODUCE A MENTION OF THE
THREAT FOR MINOR FLOODING IN THE HWO.
WITH EXTENSIVE CLOUD COVER AND PRECIP EXPANDING IN
COVERAGE...NARROWED THE DIURNAL RANGE IN TEMPS...INCREASING LOWS AND
REDUCING HIGHS...ESPECIALLY MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 230 PM EDT THURSDAY...
AN ACTIVE WEATHER PATTERN IS IN STORE FOR THE EARLY PART OF THE LONG
TERM PERIOD. BOTH THE GFS AND ECMWF PHASE THE SOUTHERN STREAM LOW
CURRENTLY IN TEXAS...WITH A NORTHERN STREAM WAVE MOVING ACROSS THE
GREAT LAKES. THE RESULTS IN A PERSISTENT LONG WAVE TROF ACROSS THE
EASTERN U.S...WITH WAVES OF LOW PRESSURE AT THE SFC RIDING NORTHEAST
ALONG A SLOW MOVING FRONTAL BOUNDARY THROUGH TUESDAY NIGHT AND
POTENTIALLY INTO WEDNESDAY.
THE 00Z ECMWF IS MOST PROGRESSIVE WITH MOVING THE AXIS OF THIS UPPER
TROF TO THE EAST OF OUR AREA WEDNESDAY...WHILE THE 06Z GFS IS MUCH
SLOWER AND DEEPER...WHICH APPEARS TO BE AN OUTLIER WHEN COMPARED TO
ITS ENSEMBLES. A SOLUTION SOMEWHERE BETWEEN IS PROBABLY THE MOST
LIKELY SCENARIO...AS THE ECMWF ENSEMBLE MEAN SUGGESTS. AS A
RESULT...KEPT POPS IN THE FORECAST FOR WEDNESDAY.
LATER THE LONG TERM PERIOD...THE LONG RANGE MODELS DIVERGENCE
CONSIDERABLY ON THE WHAT WILL TRANSPIRE. THE 12Z GFS DEVELOPS A CUT
OFF LOW IN EASTERN NC...WHILE 0Z ECMWF LIFTS THE EASTERN U.S. TROF
WELL AWAY FROM OUR AREA. THE MAJORITY OF THE INDIVIDUAL GFS
ENSEMBLES AGREE WITH THE ECMWF ENSEMBLE MEAN OF KEEPING AN OPEN
UPPER LEVEL TROF OVER THE EASTERN U.S. WITH THE RNK FORECAST AREA
JUST TO THE WEST OF THE UPPER TROF AXIS FROM THE ENSEMBLE
MEANS...WILL KEEP THE FORECAST DRY...BUT CONFIDENCE IS LOW DURING
THIS TIME.
&&
.AVIATION /05Z SATURDAY THROUGH WEDNESDAY/...
AS OF 115 AM EDT SATURDAY...
HIGH CLOUDS SPREAD INTO THE AREA FROM THE WEST TODAY. LOWER LEVELS
OF THE ATMOSPHERE WILL TAKE LONGER TO MOISTEN UP BUT WITH SURFACE
HIGH PRESSURE OFFSHORE A LOWER CEILING...BUT STILL VFR...WILL
DEVELOP THIS EVENING. HIGH CONFIDENCE THAT CONDITIONS WILL REMAIN
VFR THROUGH SUNDAY MORNING.
CEILINGS AND VISIBILITIES WILL LOWER TO MVFR LEVELS AT KBLF AND
KLWB ON SUNDAY THEN ALSO AT ALL OTHER SITES SUNDAY NIGHT THROUGH
TUESDAY AS LOW PRESSURE AND THE ASSOCIATED PRECIPITATION MOVE
EAST. IFR CONDITIONS WILL ALSO BE POSSIBLE ESPCLY ACROSS THE
WESTERN LOCATIONS SUNDAY NIGHT INTO MONDAY IN ASSOCIATION WITH AN
AXIS OF HEAVIER RAINFALL ALONG THE FRONT.
DRIER AIR SHOULD FINALLY WORK IN TUESDAY NIGHT INTO WEDNESDAY
BRINGING A RETURN TO VFR BY MIDWEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH/KK
SHORT TERM...PH
LONG TERM...PH
AVIATION...AMS/JH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1112 PM MDT SUN MAY 13 2012
.AVIATION...
WEAK OUTFLOW BOUNDARY HEADING WESTWARD TOWARDS KCOS AND KPUB WILL
SHIFT WINDS FROM A LIGHT EASTERLY DIRECTION AT THE START OF THE
TAF ISSUANCE. WIND SPEEDS WILL REMAIN LESS THAN 10 KTS.
OTHERWISE...WITH CLEARING SKIES ALOFT...MOIST LOW LEVELS AND A
WEAK EASTERLY WIND...THERE IS STILL THE POTENTIAL FOR SOME
FRAGMENTED STRATUS DEVELOPMENT WITH BASES AROUND 010. WILL KEEP
THE SCT010 LAYER IN GOING TAFS AFTER 09Z...WITH POTENTIAL FOR
GROUND FOG AS NORTHERLY DRAINAGE WIND PICKS UP AT KCOS WHICH
SHOULD HELP PREVENT ANY WIDESPREAD PERSIST STRATUS DEVELOPMENT.
PERHAPS A LITTLE BETTER CHANCE FOR STRATUS AT KPUB THROUGH THE
MORNING HOURS. MON MORNING...CLEARING SKIES AND LIGHT WINDS WILL
KEEP CONDITIONS IN THE VFR CATEGORY FOR ALL 3 TAF SITES WITH WIND
SPEEDS UNDER 10 KTS. -KT
&&
.PREV DISCUSSION... /ISSUED 956 PM MDT SUN MAY 13 2012/
UPDATE...
UPDATED FORECAST TO DECREASE POPS ACROSS WESTERN AND NORTHERN
PORTIONS OF THE FORECAST AREA. SCATTERED TO WIDESPREAD SHOWERS
WITH EMBEDDED THUNDERSTORMS WILL CONTINUE ACROSS THE SOUTHEAST
PLAINS THROUGH 06Z BEFORE DIMINISHING ACROSS MOST OF THE AREA BY
09Z. HRRR SEEMS TO HAVE A FAIR HANDLE ON THE PROGRESSION OF THE
PCPN...AND HAVE FOLLOWED IT FOR POPS IN THE LATEST GRID UPDATE. -KT
AVIATION...
OUTFLOW BOUNDARIES FROM CONVECTION OUT EAST ARE HEADING WESTWARD
TOWARDS KCOS AND KPUB...AND MAY BRING A BRIEF WIND SHIFT FROM AN
EASTERLY DIRECTION TO BOTH TERMINALS BETWEEN 04 AND 06Z. THIS MAY
HELP WITH SOME LOW STRATUS DEVELOPMENT AND WILL CONTINUE TO BE
MONITORED TOWARDS THE 06Z TAF ISSUANCE. -KT
PREV DISCUSSION... /ISSUED 242 PM MDT SUN MAY 13 2012/
SHORT TERM...
(TONIGHT AND MONDAY)
.ONE LAST CHANCE AT GETTING SOME RAIN...
UPPER LOW CENTER IS DROPPING SOUTH ACROSS WESTERN COLORADO CENTERED
NEAR GRAND JUNCTION AT THE PRESENT TIME. LEFT FRONT QUADRANT
ACTIVITY ASSOCIATED WITH 70 KNOT JETSTREAM MAXIMA MOVING BY TO THE
SOUTH OF THE 4 CORNERS...IS TRIGGERING WIDESPREAD SHOWERS AND
THUNDERSTORMS OVER THE SOUTHERN HALF OF THE FORECAST AREA. NORTHERN
HALF OF THE FORECAST AREA IS BEING AFFECTED BY LIFT ASSOCIATED WITH
UPPER LEVEL DIFFLUENT FLOW AND COLD POOL NEAR UPPER LOW CENTER.
THE 2 FEATURES WILL COMBINE TO GIVE MUCH OF SOUTHERN COLORADO
ANOTHER SHOT AT SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING...
BEFORE EVERYTHING SHIFTS SOUTH INTO NEW MEXICO AFTER MIDNIGHT. SO
FAR TODAY...THERE HAVE BEEN PEA TO HALF INCH SIZE HAIL REPORTS IN AN
AND AROUND THE AREA. A BRIEFLY INTENSE PULSE STORM THAT DEVELOPED
NEAR FLORISSANT EARLIER...HAD A 48 DBZ CORE UP TO ABOUT 34,000 FEET
MSL...MINOR ROTATION...AND A VIL HITTING 30. AT THAT ELEVATION...IN
THIS ENVIRONMENT...WITH A GOOD AMOUNT OF COLD AIR ALOFT...SOME
QUARTER SIZE HAIL WAS CERTAINLY PLAUSIBLE. SAW THIS HAPPEN FROM A
STORM 2 MILES EAST OF SOUTH FORK YESTERDAY. FOR THE REMAINDER OF
THE EVENING...EXPECT SHOWERS AND THUNDERSTORMS TO SPREAD OFF OF THE
MOUNTAINS ONTO THE PLAINS AND CONTINUE EASTWARD...PROBABLY WITH
BETTER SUCCESS THAN LAST NIGHT. ATMOSPHERE IS A BIT LESS STABLE
TODAY AND DEWPOINTS ARE NOW WIDESPREAD LOWER TO UPPER 40S ACROSS THE
PLAINS. THIS SHOULD HELP THE SUCCESS OF THE EVENING CONVECTION
ACROSS THE PLAINS.
MOST ACTIVITY SHOULD SHIFT SOUTH INTO NEW MEXICO BY MIDNIGHT...WITH
JUST SOME LINGERING ACTIVITY SOUTHERN AREAS PAST MIDNIGHT. COULD
SEE SOME PATCHY GROUND FOG IN A LOT OF AREAS TOWARD MORNING AS SKIES
START TO CLEAR. ONCE THE FOG GETS OUT OF HERE IN THE MORNING...WE
SHOULD BE LOOKING AT A MOSTLY SUNNY DAY WITH VERY PLEASANT SEASONAL
SPRING TEMPERATURES. STILL AN ISOLATED STORM CHANCE SOUTHERN
MOUNTAIN AREAS...BUT LIKELY THE EXCEPTION...NOT THE RULE.
THIS JUST IN...JUST HEARD FROM ONE OF OUR HAM RADIO COOPERATORS.
APPARENTLY...THE CELL THAT WAS WARNED ON OVER TELLER COUNTY EARLIER
DROPPED PEA SIZE HAIL...TO A 1 INCH DEPTH...IN A SWATH FROM THE LAKE
GEORGE AREA EASTWARD THROUGH THE FLORISSANT CANYON...TO WITHIN 5
MILES OR SO WEST OF WOODLAND PARK. ALSO GOT A REPORT FROM ANOTHER
SPOTTER 2 MILES NORTH OF WOODLAND PARK OF 1/2 DIAMETER HAIL IN THE
PAST HOUR. SPRINGTIME IS FUN TIME IN THE ROCKIES. LW
LONG TERM...
(MONDAY NIGHT THROUGH NEXT SUNDAY)
REST OF THE WEEK INTO NEXT WEEKEND LOOKS RELATIVELY BENIGN WITH
GENERALLY ABOVE AVERAGE TEMPERATURES AND NO SIGNIFICANT STORMS ON
THE HORIZON.
TUESDAY...SHOULD BE WARM AND DRY AS AN UPPER RIDGE MOVES SEWD
THROUGH CO. TEMPS SHOULD CLIMB INTO THE 80S OVR THE PLAINS...AND
50S-60S FOR THE MTN AREAS. BY WED...FIRST OF A COUPLE SHORT WAVES
MOVES THROUGH FROM THE W. THE TROUGH AXIS LOOKS TO BE MOSTLY EA OF
OUR AREA BY 00Z THU...AND BEST MID LEVEL WINDS AND FORCING LOOK TO
BE FARTHER N...SO STRONGEST AFTERNOON OR EVE CONVECTION AT THIS
POINT LOOKS TO BE MAINLY NE OF OUR CWA. HAVE INTRODUCED LOW POPS
HOWEVER FOR THE ERN PLAINS IN THE LATE AFTERNOON AND EVENING HOURS.
THERE IS JUST ENOUGH BULK SHEAR AND INSTABILITY THAT A COUPLE STRONG
STORMS CANNOT BE RULED OUT.
THE RIDGE REBUILDS THU INTO FRI...AND AGAIN IT SHOULD BE MOSTLY DRY
BOTH DAYS FOR THE ENTIRE AREA...WITH TEMPS IN THE UPPR 80S TO
POSSIBLY NR 90 DEGREES OVR THE PLAINS. NEXT DISTURBANCE MOVES IN
LATE FRI INTO SAT...AND A COLD FRONT ASSOCIATED WITH THIS SYSTEM
WILL PUSH INTO ERN CO SOMETIME ON SAT. SOME POTENTIAL FOR STRONGER
CONVECTION WITH THIS SYSTEM...AS DEEPER MOISTURE WITH HIGHER
DEWPOINTS BEGINS TO SURGE WWD OVR THE PLAINS BY LATE IN THE DAY OR
INTO SUN. NOT VERY CONFIDENT WITH THE MODEL SOLUTIONS FOR THE LATTER
PART OF THE WEEKEND...AS THE GFS AND ECMWF CONTINUE TO BE OUT OF
PHASE BEYOND SAT. 44
AVIATION...
CATTERED THUNDERSTORMS HAVE DEVELOPED OVER THE HIGHER TERRAIN AND
WILL SPREAD ONTO THE PLAINS THROUGH THE REMAINDER OF THE AFTERNOON
INTO THE EVENING. WILL CONTINUE AT LEAST VCTS MENTION ALL TAF SITES
THROUGH 02Z TIME PERIOD...WITH POTENTIAL FOR AT LEAST BRIEF MVFR
CONDITIONS UNDER A FEW OF THE STRONGER STORMS. MAINLY VFR CONDITIONS
SPREADING FROM NORTH TO SOUTH 03Z-06Z TIME FRAME AS TSRA MOVE INTO
NM...THOUGH DUE TO RECENT PRECIPITATION AND LIGHT WINDS...WILL HAVE
TO WATCH FOR PATCHY GROUND FOG DEVELOPMENT AROUND SUNRISE MONDAY...
ESPECIALLY AT KALS AND KPUB. LW
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31/13
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1125 PM MDT SUN MAY 13 2012
.UPDATE...
ISSUED AT 837 PM MDT SUN MAY 13 2012
JUST ISSUED ANOTHER UPDATE. CURRENT PRECIPITATION FORECAST IS
TRENDING AND MADE NO CHANGES. THERE WAS LITTLE WIND/MIXING THROUGH
THE DAY WITH DEWPOINTS NEARLY THE SAME TODAY AS YESTERDAY. AREA
SOUNDINGS SHOW THAT THE LOW LEVEL MOISTURE HAS ALSO CHANGED LITTLE
ALTHOUGH THE AIR MASS HAS WARMED. WITH A SIMILAR AIR MASS
YESTERDAY THERE WAS SOME MORNING FOG. ALSO CLUSTER OF
THUNDERSTORMS DROPPED A DECENT AMOUNT OF RAINFALL OVER A RATHER
LARGE AREA OVER WESTERN KIT CARSON AND CHEYENNE COUNTIES.
WINDS WILL BE LIGHT AND THEN WILL SHIFT TO THE WEST TO BRING THIS
MOISTURE IN FROM THE WEST. CONSIDERING THE RUC THAT HAS A GOOD
HANDLE ON THE WIND FIELD...DRIER AIR WORKS ITS WAY INTO THE
NORTHEAST HALF OF THE AREA. RUC AND TO A LESSER DEGREE THE ECMWF
INCREASE LOW LEVEL MOISTURE OVER THE SOUTHWEST HALF ALTHOUGH THE
RUC WOULD SAY IT WILL BE STRATUS. AS A RESULT...ADDED PATCHY TO
AREAS OF FOG FOR LATER TONIGHT INTO TOMORROW MORNING. LATEST MAV
WAS DOING WELL WITH THE DEWPOINTS AND AS STATED ABOVE USED THE RUC
FOR THE WINDS AND BLENDED THEM WITH REALITY. OVERNIGHT LOWS LOOK
FINE AT THIS TIME.
UPDATE ISSUED AT 623 PM MDT SUN MAY 13 2012
PERSISTENT AND SLOW MOVING CLUSTER OF STORMS LOCATED OVER/NEAR WESTERN
KIT CARSON AT THIS TIME. THIS AREA LOOKS TO BE IN AN AREA OF
SURFACE/MOISTURE CONVERGENCE COMBINED WITH WEAK SHORTWAVE TROUGH
AND DEEPEST MOISTURE. RAISED POPS MUCH HIGHER OUT WEST...EXPANDED
AREA OF THUNDERSTORMS AND PER CONVERGENCE AND QPF FORECASTS...EXTENDED
THUNDERSTORMS UNTIL 06Z. ALSO INCREASED CLOUD COVER OVER THE WEST
AND SOUTHWEST PORTIONS OF THE AREA WHERE CONVECTION IS OCCURRING.
OTHERWISE JUST MADE MINOR ADJUSTMENTS WITH THE REMAINING ELEMENTS.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH MONDAY EVENING)
ISSUED AT 1157 AM MDT SUN MAY 13 2012
SCATTERED TO BROKEN SKY COVER THIS AFTERNOON WILL PERSIST WITH THE
DAYTIME HEATING PRODUCING A WIDESPREAD CU FIELD. EXPECT THIS TO
DISSIPATE RAPIDLY FOLLOWING SUNSET WITH DRYER AIR MOVING IN MONDAY
AND MONDAY NIGHT AS THE RIDGE OF HIGHER PRESSURE MOVES OVER THE
ROCKIES AND HIGH PLAINS REGION. THERE IS SOME CONVECTIVE ACTIVITY
DEVELOPING OVER THE HIGH TERRAIN OF COLORADO THIS AFTERNOON...SO
THERE IS THE POSSIBILITY OF A FEW SHOWERS MAKING THEIR WAY OVER
THE FAR SOUTHWESTERN PORTION OF THE FORECAST AREA LATE THIS
AFTERNOON AND EARLY EVENING. ANY SHOWERS THAT DO MAKE IT THIS FAR
EAST SHOULD DISSIPATE RAPIDLY AFTER 03Z.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 236 PM MDT SUN MAY 13 2012
TUESDAY-TUESDAY NIGHT...SHORTWAVE RIDGE WILL REMAIN IN PLACE THROUGH
TUESDAY NIGHT...WITH LARGE SCALE SUBSIDENCE SUPPORTING DRY
CONDITIONS. MUCH WARMER TEMPERATURES ARE EXPECTED WITH GUIDANCE
CONTINUING TO SUPPORT TEMPS IN THE MID TO UPPER 80S OVER MUCH OF THE
CWA...WITH TEMPS AROUND 90F IN THE EAST.
WEDNESDAY-THURSDAY NIGHT...VERY WARM TEMPERATURES CONTINUE WITH
SOUTHERLY FLOW IN PLACE AND H85 TEMPS AROUND 25C. HIGHS ON WEDNESDAY
AND THURSDAY WILL BE VERY SIMILAR TO TUESDAY...WITH HIGHS OVER MUCH
OF THE CWA IN THE UPPER 80S. H5 RIDGE BEGINS TO BREAK DOWN WEDNESDAY
AS A SHORTWAVE TROUGH MOVES TOWARDS THE INTER-MOUNTAIN WEST/HIGH
PLAINS. STILL SOME RUN-RUN SPREAD BETWEEN GUIDANCE ON
TIMING/POSITION OF THIS FEATURE...WITH 12Z ECMWF SLOWER AND DRIER.
GFS AND NAM STILL SUPPORT TIMING/COVERAGE FROM PREVIOUS FORECAST
WITH THUNDERSTORMS BEGINNING IN EASTERN COLORADO WEDNESDAY AFTERNOON
AND SPREADING EAST ACROSS THE CWA THROUGH THURSDAY. COVERAGE IS
STILL A QUESTION EVEN WITH THE GFS/NAM SOLUTIONS...WITH LIMITED
MOISTURE ADVECTION AND INSTABILITY WEDNESDAY/WEDNESDAY NIGHT. I
KEPT POPS LIMITED TO SLIGHT CHANCE CATEGORY...AND MADE ONLY MINOR
ADJUSTMENTS TO LOCATION OF POPS IN CWA. IF GFS/NAM IS CORRECT THEN
BEST CHANCE FOR PRECIP WITH THIS FEATURE MAY END UP BEING THURSDAY
OVER OUR EASTERN CWA.
FRIDAY-SUNDAY...SUBSIDENCE ASSOCIATED WITH SHORTWAVE RIDGE SHOULD
KEEP FRIDAY WARM AND DRY. PRECIP CHANCES RETURN BY SATURDAY AS SW
FLOW SET UP ACROSS CWA...AND COLD FRONT DROPS SOUTH ACROSS CWA
SUNDAY. THERE IS STILL CONSIDERABLE SPREAD IN UPPER LEVEL PATTERN
BETWEEN OPERATIONAL GUIDANCE...HOWEVER BOTH GFS AND ECMWF SUPPORT
PRECIP CHANCES SATURDAY THROUGH SUNDAY NIGHT. I CONSIDERED RAISING
POPS...HOWEVER WITH SPREAD ON UPPER LEVEL AND SURFACE FEATURES...ITS
DIFFICULT TO PIN DOWN FAVORED LOCATIONS AT THIS TIME. RATHER THAN
STRAY TOO FAR FROM PREVIOUS TRENDS...I KEPT POPS IN SLIGHT
CHANCE/CHANCE CATEGORIES DURING THESE PERIODS TO ACCOUNT FOR MODEL
SPREAD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1121 PM MDT SUN MAY 13 2012
VFR CONDITIONS AND LIGHT WINDS ARE EXPECTED THROUGH THE PERIOD.
SOME FOG IS EXPECTED AROUND KGLD BUT AT THIS TIME DO NOT EXPECT
CREATE BELOW VFR CONDITIONS.
&&
.FIRE WEATHER...
ISSUED AT 236 PM MDT SUN MAY 13 2012
RED FLAG CONDITIONS WILL BE POSSIBLE WEDNESDAY THROUGH FRIDAY WITH
RH VALUES AND WINDS APPROACHING CRITERIA. BEST CHANCE FOR RED FLAG
CRITERIA TO BE MET LOOKS TO BE ON WEDNESDAY AFTERNOON WHEN WINDS
GUSTING OVER 25 MPH WILL BE COMMON ACROSS THE CWA. THERE ARE STILL
QUESTIONS ON HOW LOW RH VALUES WILL BE WEDNESDAY WITH SHORTWAVE
TROUGH MOVING IN FROM THE WEST. IF PROFILES REMAIN DRY ADIABATIC
THROUGH THE AFTERNOON...CURRENT TD/RH FORECAST COULD BE TOO HIGH.
THIS WILL NEED TO BE MONITORED.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...LOCKHART
LONG TERM...DR
AVIATION...BULLER
FIRE WEATHER...DR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
210 AM EDT MON MAY 14 2012
.SYNOPSIS...
AN UPPER LEVEL TROUGH AND ASSOCIATED SURFACE LOW PRESSURE SYSTEM
WILL SLOWLY PROGRESS EAST TOWARD THE SOUTHEAST COAST THROUGH MID
WEEK...RESULTING IN AN EXTENDED PERIOD OF UNSETTLED WEATHER.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 925 PM SUNDAY...
FOR THE REST OF TONIGHT: THE MID LEVEL TROUGH AXIS EXTENDS FROM LAKE
HURON THROUGH INDIANA TO THE LOWER OH VALLEY AND MS THIS EVENING...
AND NUMEROUS MINOR PERTURBATIONS CONTINUE TO TRACK UP THE EAST SIDE
OF THE TROUGH THROUGH WESTERN/CENTRAL NC. THIS WEAK BUT PERSISTENT
DPVA AND A SUBTLE DISSIPATING POCKET OF UPPER DIVERGENCE AS WELL
AS DEEPENING AND STRENGTHENING ISENTROPIC UPGLIDE THROUGH 295K-
310K ACTING ON COPIOUS MOISTURE (PRECIPITABLE WATER HAS RISEN FROM
JUST BELOW NORMAL TO NEARLY 150% OF NORMAL SINCE THIS MORNING) HAS
PRODUCED WIDESPREAD LIGHT RAIN AND DRIZZLE OVER CENTRAL NC SINCE
LATE AFTERNOON... PARTICULARLY ON THE WESTERN PIEDMONT. THIS LIGHT
RAIN/DRIZZLE AREA... COINCIDENT WITH ONE PARTICULAR BETTER-DEFINED
MID LEVEL WAVE... WILL CONTINUE TO MOVE TOWARD THE NORTH NORTHEAST
OVER THE NEXT SEVERAL HOURS... AND WILL LIKELY BE FOLLOWED BY A
BREAK IN STEADY PRECIPITATION FROM SSW TO NORTH NORTHEAST
OVERNIGHT... AS NOTED ON THE HRRR MODEL WHICH IS HANDLING THE
CURRENT PRECIPITATION WELL. BUT WITH STEADY ADVECTION IN THE
LOWEST 3 KM OF WARM AND VERY MOIST AIR... AND CONVERGENT FLOW AT
850 MB THROUGH THE CENTRAL CAROLINAS EVIDENT ON 00Z UPPER AIR
ANALYSES... THE CHANCES FOR MORE PRECIPITATION OVERNIGHT ARE QUITE
HIGH... ESPECIALLY OVER THE WESTERN PIEDMONT GIVEN MODEL
INDICATIONS OF SUBSTANTIAL LOW LEVEL MOISTURE TRANSPORT CONTINUING
IN THIS AREA THROUGH DAYBREAK. NOT OVERLY CONCERNED ABOUT MUCH
THUNDER TONIGHT CONSIDERING THE LACK OF MID LEVEL HEIGHT FALLS AND
WEAKENING UPPER LEVEL WIND FIELD... PLUS THE DEEP LAYER SHEAR IS
VERY WEAK AS ARE THE LOW- AND MID-LEVEL LAPSE RATES. BUT
CONSIDERING THE INCOMING PUNCH OF MID LEVEL DRY AIR NOTED ON WATER
VAPOR IMAGERY AND 00Z SOUNDINGS FROM THE DEEP SOUTH AND WESTERN
GULF COAST... POCKETS OF BETTER (YET STILL VERY MODEST)
DESTABILIZATION REMAIN POSSIBLE AND THE RISK OF ISOLATED THUNDER
WILL BE RETAINED OVERNIGHT. WITH THE LIGHT NATURE OF THE
PRECIPITATION SO FAR AND EXPECTED SPOTTY NATURE OF ADDITIONAL
SHOWERS AND ISOLATED STORMS OVERNIGHT... HAVE CUT BACK FORECAST
PRECIPITATION AMOUNTS THROUGH DAWN TO NO MORE THAN A THIRD OF AN
INCH WEST TO JUST A FEW HUNDREDTHS EAST... ALTHOUGH THE THREAT OF
HEAVIER RAIN ON MONDAY STILL APPEARS ON TRACK. EXPECT NEARLY
STEADY TEMPS IN THE 60-65 RANGE OVER MUCH OF THE AREA FOR THE REST
OF THE NIGHT. -GIH
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
AS OF 235 PM SUNDAY...
MONDAY AND MONDAY NIGHT:
BROAD UPPER-LEVEL TROUGH IN PLACE FROM THE GREAT LAKES TO THE LOWER
MS VALLEY WILL GET REINFORCED BY SHORTWAVE TROUGH DIVING SOUTHEAST
ALONG THE SOUTHERN ROCKIES AND INTO THE SOUTHERN PLAINS ON MONDAY.
MEANWHILE...WEAK FRONTAL ZONE AND ASSOCIATED WAVE OF LOW PRESSURE
OVER THE SOUTHERN APPALACHIANS WILL INCH SLOWLY EASTWARD INTO THE
WESTERN CAROLINAS THROUGH MONDAY NIGHT. SHORTWAVE ENERGY IS EXPECTED
TO EJECT EAST-NORTHEASTWARD ACROSS THE AREA IN THE SOUTHWEST FLOW
ALOFT DOWNSTREAM OF THE BROAD TROUGH AND WITHIN THE ANOMALOUSLY
HIGH (2 STD ABOVE NORMAL)PRECIPITABLE WATER AIR MASS LYING ALONG
AND EAST OF THE WEAK FRONTAL ZONE ACROSS WESTERN NC. DAYTIME
HEATING OF THE MOIST BOUNDARY LAYER WILL SUPPORT NUMEROUS TO
WIDESPREAD SHOWERS/THUNDERSTORMS MONDAY AFTERNOON/EVENING...WITH
AN AXIS OF MODERATE TO HEAVY RAINFALL NOT BUDGING VERY
MUCH...CENTERED ALONG AND ON THE EASTERN SLOPES OF THE
APPALACHIANS AND POTENTIALLY EXTENDING EAST INTO THE WESTERN
PIEDMONTS OF NC AND VIRGINIA. WHILE THERE REMAINS SOME UNCERTAINTY
WITH REGARD TO TO THE TIMING OF THE EMBEDDED SHORTWAVE
IMPULSES...MODEL CONSENSUS INDICATES THAT THE HEAVY RAINFALL AXIS
AND HIGHEST WILL SHIFT EASTWARD MONDAY NIGHT...REACHING THE
COASTAL SECTIONS BY DAYBREAK TUESDAY.
SEVERE WEATHER THREAT:
WHILE MOIST ADIABATIC PROFILES WILL SUPPORT WEAK MID-LEVEL LAPSE
RATES AND INSOLATION SHOULD BE GREATLY IMPEDED BY WIDESPREAD
CLOUDS...MODELS STILL SUGGEST THE POTENTIAL FOR WEAK TO MODERATE
DESTABILIZATION COULD DEVELOP MONDAY AFTERNOON. UNIDIRECTIONAL
SOUTHWEST FLOW OF 25-30 KT COULD SUPPORT A CLUSTER OR TWO OF
STRONG TO SEVERE THUNDERSTORMS THAT COULD PRODUCE DAMAGING WET
MICROBURSTS. WITH LOSS OF DAYTIME HEATING ...THE THREAT OF SEVERE
WEATHER SHOULD BE ON THE WANE MONDAY NIGHT AS THE AIR MASS
COOLS/STABILIZES.
HEAVY RAIN THREAT:
WHILE IT WILL GREATLY DEPEND ON HOW MUCH RAINFALL WE SEE THIS
AFTERNOON AND TONIGHT...THE WESTERN PIEDMONT/TRIAD AREA COULD
POTENTIALLY ADD ANOTHER 1 TO 2 INCHES MONDAY AND MONDAY NIGHT TO
WHATEVER WE SEE TONIGHT. 3 HOUR FLASH FLOOD GUIDANCE TODAY FOR THOSE
AREAS ARE AROUND 3.0"...BUT IF WE RECEIVE AN INCH OF RAIN
TONIGHT...IT SHOULD LOWER THE GUIDANCE SIGNIFICANTLY...CLOSE TO THE
TWO INCH THRESHOLD. LATER SHIFTS MAY NEED TO CONSIDER A FLASH FLOOD
WATCH FOR THE WESTERN PIEDMONT MONDAY AFTERNOON/MONDAY NIGHT. EAST
OF THE TRIAD...EXPECT AVERAGE RAINFALL AMOUNTS OF 0.50-1.0"... WITH
ONLY LOCALIZED/URBAN FLOODING EXPECTED.
TEMPERATURES:
HIGHS MONDAY WILL DEPEND ON SHOWER/STORM COVERAGE AND WHETHER WE
WILL MANAGE TO SEE ANY BREAKS IN THE EAST. AFTERNOON HIGHS RANGING
FROM AROUND 70 WEST TO AROUND 80 EAST. LOWS MONDAY NIGHT AGAIN
IN THE 60S. -CBL
TUESDAY AND TUESDAY NIGHT:
ONGOING SHOWERS AND STORMS TUESDAY MORNING SHOULD BE MOVING INTO THE
COASTAL PLAIN AS THE AXIS OF DEEPEST MOISTURE FINALLY SHIFTS TOWARD
THE COAST. HOWEVER...THE WEAK SURFACE FRONT IS FORECAST LINGER BACK
TO THE WEST ALONG THE MOUNTAINS WHILE THE UPPER TROUGH ENERGY
CONTINUES TO EVOLVE WEST OF THE MOUNTAINS....EVENTUALLY PUSHING INTO
THE AREA TUESDAY EVENING. WITH SLIGHTLY DRIER AIR FORECAST TO
OVERSPREAD CENTRAL NC...SOME BREAKS IN CLOUD COVER AND STRONGER
DESTABILIZATION ARE EXPECTED. AHEAD OF THE UPPER TROUGH... THE MAY
CONTINUE TO BE SUBTLE DISTURBANCES ALOFT MOVING ACROSS THE
PERSISTENT WARM AND MOIST AIR MASS...LEADING TO A SCATTERED SHOWERS
AND STORMS BY TUESDAY AFTERNOON. THE NAM IS STRONGEST AND SHOWING A
STOUT VORTICITY MAX LIFTING ACROSS THE AREA DURING PEAK HEATING. A
TIGHTER HEIGHT FIELD ASSOCIATED WITH THIS FEATURE LEADS TO STRONGER
DEEP LAYER SHEAR FORECAST BY THE NAM...BUT THE NAM SEEMS TO BE
OVERDONE. THE GFS AND ECMWF SHOW MORE A MORE DIFFUSE WAVE AND
ONLY 20-25KT OF 0-6KM BULK SHEAR...WHICH IS SUPPORTED BY MOST SREF
MEMBERS. THERE IS CONSIDERABLE SPREAD AMONG SREF MEMBERS REGARDING
INSTABILITY...BUT MODIFIED GFS SOUNDINGS FOR TEMPS IN THE UPPER 70S
TO LOWER 80S AND DEWPOINTS IN THE LOWER 60S SHOW 500-1000 J/KG OF
MLCAPE. A FEW ISOLATED SEVERE STORMS MAY BE POSSIBLE...BUT IF THE
UPPER WAVE IS STRONGER...AS THE NAM FORECASTS...THEN THE SEVERE
POTENTIAL WILL BE GREATER. HIGHS 77-82.
AS THE SURFACE FRONT AND MAIN LOW LEVEL CONVERGENCE ZONE PUSHES INTO
THE CWA TUESDAY EVENING...ISOLATED SHOWERS AND STORMS MAY CONTINUE
INTO THE OVERNIGHT HOURS. THE FRONT WILL CONTINUE TO BE RATHER SLOW
MOVING...AND LOWS SHOULD BE FAIRLY PERSISTENT IN THE UPPER 50S TO
LOWER 60S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 205 AM...
A BAGGY UPPER TROUGH IS FORECAST TO BE DROPPING OFF THE MOUNTAINS
INTO THE FOOTHILLS AT SUNRISE WEDNESDAY. PROGRESS IS SLOW WITH THE
TROUGH AXIS NO FURTHER EAST THAN HIGHWAY ONE AT SUNSET. THE GFS
CONTINUES TO BE SHARPEST AND MOST PROGRESSIVE WITH UPPER LEVEL
RIDGING IN THE MIDWEST...SLOWING THE EASTWARD PROGRESS OF THE EAST
COAST TROUGH. THE MAJORITY OF MODELS ARE FLATTER AND FURTHER WEST
WITH MIDWEST RIDGING... WITH THE 850 MILLIBAR TROUGH WELL EAST OF
CENTRAL NORTH CAROLINA BY SUNSET. WILL FAVOR THE CONSENSUS WITH
SLIGHT CHANCES FOR SHOWERS WEDNESDAY MORNING... AND SMALL
AFTERNOON CHANCES FOR THUNDERSTORMS IN THE EAST EXITING DURING
THE EVENING.
WEAK HIGH PRESSURE ADVANCES TOWARD THE MID ATLANTIC STATES WEDNESDAY
NIGHT AND THURSDAY. MID LEVEL FLOW OVER THE CAROLINAS IS WEAK AND
GENERALLY FROM THE WEST TO NORTHWEST. MEASURABLE RAIN CHANCES APPEAR
MINIMAL IN THIS PATTERN AND WILL PLACE CHANCES AT LESS THAN SLIGHT.
1000 TO 850 MILLIBAR THICKNESSES FORECAST TO BE NEAR CLIMATOLOGY.
EXPECT ENOUGH SUNSHINE BOTH DAYS FOR AFTERNOON HIGH TEMPERATURES
SETTLE NEAR CLIMATOLOGY AS WELL... WITH HIGHS IN THE UPPER 70S TO
LOWER 80S. LOW TEMPERATURES WEDNESDAY AND THURSDAY NIGHTS IN THE MID
TO UPPER 50S.
MID LEVEL HIGH PRESSURE OVER TENNESSEE FRIDAY WILL EXPAND TOWARD NEW
ENGLAND DURING THE WEEKEND. A BROAD AREA OF LOW PRESSURE IS EXPECTED
TO BE CENTERED FAR ENOUGH OFF THE CAROLINA COAST TO LEAVE CENTRAL
NORTH CAROLINA DRY FRIDAY INTO SUNDAY. WITH THE WEATHER PATTERN OVER
THE SOUTHEAST SOMEWHAT STATIC AND LOW LEVEL THICKNESSES NEAR
CLIMATOLOGY... TEMPERATURES WILL FOLLOW SUIT. AFTERNOON HIGH
TEMPERATURES IN THE UPPER 80S TO LOWER 80S AND LOWS IN THE UPPER
50S TO LOWER 60S.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 1205 AM MONDAY...
24-HR TAF PERIOD:
DETERIORATING CONDITIONS ARE EXPECTED THIS MORNING...WITH LITTLE (IF
ANY) IMPROVEMENT THROUGH THE REMAINDER OF THE TAF PERIOD. AN UPPER
LEVEL TROUGH AND ASSOCIATED SURFACE LOW PRESSURE SYSTEM WILL
CONTINUE TO SLOWLY APPROACH THE CAROLINAS FROM THE WEST TODAY AND
TONIGHT. PERIODS OF SHOWERS ARE EXPECTED THIS MORNING...WITH
CEILINGS LOWERING TO IFR/LIFR AT THE INT/GSO TERMINALS AND MVFR/IFR
AT THE RDU/FAY/RWI TERMINALS. PERIODS OF SHOWERS AND THUNDERSTORMS
ARE EXPECTED THIS AFTERNOON...WITH ONLY A MARGINAL IMPROVEMENT IN
CEILINGS DURING PEAK HEATING. EXPECT CEILINGS AND VISBYS TO DECREASE
INTO THE IFR/LIFR RANGE EVERYWHERE BETWEEN SUNSET THIS EVENING AND
SUNRISE TUESDAY MORNING. SE/SSE WINDS AT ~5 KT WILL PERSIST THROUGH
SUNRISE...WITH SE/SSE WINDS INCREASING TO ~10 KT BY THIS AFTERNOON.
LOOKING AHEAD:
LINGERING LOW LEVEL MOISTURE COMBINED WITH ANOTHER UPPER LEVEL
TROUGH APPROACHING THE AREA FROM THE NORTHWEST WILL ALLOW ADVERSE
AVIATION CONDITIONS TO PERSIST TUESDAY/TUESDAY NIGHT...WITH
SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE AT ALL TERMINALS.
IMPROVING CONDITIONS ARE EXPECTED WEDNESDAY/WEDNESDAY NIGHT AS THE
UPPER LEVEL TROUGH AND ASSOCIATED SURFACE LOW PROGRESS CLOSER
TOWARD THE SOUTHEAST COAST... THOUGH MVFR CONDITIONS APPEAR LIKELY
IN MANY LOCATIONS. UNCERTAINTY INCREASES TOWARD THE LATTER PORTION
OF THE WEEK. AT THIS TIME... VFR/MVFR CEILINGS (2500-4500 FT AGL)
ARE EXPECTED THURSDAY/FRIDAY. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...GIH
SHORT TERM...SMITH/CBL
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1213 AM EDT MON MAY 14 2012
.SYNOPSIS...
AN UPPER LEVEL TROUGH AND ASSOCIATED SURFACE LOW PRESSURE SYSTEM
WILL SLOWLY PROGRESS EAST TOWARD THE SOUTHEAST COAST THROUGH MID
WEEK...RESULTING IN AN EXTENDED PERIOD OF UNSETTLED WEATHER.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 925 PM SUNDAY...
FOR THE REST OF TONIGHT: THE MID LEVEL TROUGH AXIS EXTENDS FROM LAKE
HURON THROUGH INDIANA TO THE LOWER OH VALLEY AND MS THIS EVENING...
AND NUMEROUS MINOR PERTURBATIONS CONTINUE TO TRACK UP THE EAST SIDE
OF THE TROUGH THROUGH WRN/CENTRAL NC. THIS WEAK BUT PERSISTENT DPVA
AND A SUBTLE DISSIPATING POCKET OF UPPER DIVERGENCE AS WELL AS
DEEPENING AND STRENGTHENING ISENTROPIC UPGLIDE THROUGH 295K-310K
ACTING ON COPIOUS MOISTURE (PRECIPITABLE WATER HAS RISEN FROM JUST
BELOW NORMAL TO NEARLY 150% OF NORMAL SINCE THIS MORNING) HAS
PRODUCED WIDESPREAD LIGHT RAIN AND DRIZZLE OVER CENTRAL NC SINCE
LATE AFTERNOON... PARTICULARLY ON THE WESTERN PIEDMONT. THIS LIGHT
RAIN/DRIZZLE AREA... COINCIDENT WITH ONE PARTICULAR BETTER-DEFINED
MID LEVEL WAVE... WILL CONTINUE TO MOVE TOWARD THE NNE OVER THE NEXT
SEVERAL HOURS... AND WILL LIKELY BE FOLLOWED BY A BREAK IN STEADY
PRECIP FROM SSW TO NNE OVERNIGHT... AS NOTED ON THE HRRR MODEL WHICH
IS HANDLING THE CURRENT PRECIP WELL. BUT WITH STEADY ADVECTION IN
THE LOWEST 3 KM OF WARM AND VERY MOIST AIR... AND CONVERGENT FLOW AT
850 MB THROUGH THE CENTRAL CAROLINAS EVIDENT ON 00Z UPPER AIR
ANALYSES... THE CHANCES FOR MORE PRECIP OVERNIGHT ARE QUITE HIGH...
ESPECIALLY OVER THE WESTERN PIEDMONT GIVEN MODEL INDICATIONS OF
SUBSTANTIAL LOW LEVEL MOISTURE TRANSPORT CONTINUING IN THIS AREA
THROUGH DAYBREAK. NOT OVERLY CONCERNED ABOUT MUCH THUNDER TONIGHT
CONSIDERING THE LACK OF MID LEVEL HEIGHT FALLS AND WEAKENING UPPER
LEVEL WIND FIELD... PLUS THE DEEP LAYER SHEAR IS VERY WEAK AS ARE
THE LOW- AND MID-LEVEL LAPSE RATES. BUT CONSIDERING THE INCOMING
PUNCH OF MID LEVEL DRY AIR NOTED ON WATER VAPOR IMAGERY AND 00Z
SOUNDINGS FROM THE DEEP SOUTH AND WESTERN GULF COAST... POCKETS OF
BETTER (YET STILL VERY MODEST) DESTABILIZATION REMAIN POSSIBLE AND
THE RISK OF ISOLATED THUNDER WILL BE RETAINED OVERNIGHT. WITH THE
LIGHT NATURE OF THE PRECIP SO FAR AND EXPECTED SPOTTY NATURE OF
ADDITIONAL SHOWERS AND ISOLATED STORMS OVERNIGHT... HAVE CUT BACK
FORECAST PRECIP AMOUNTS THROUGH DAWN TO NO MORE THAN A THIRD OF AN
INCH WEST TO JUST A FEW HUNDREDTHS EAST... ALTHOUGH THE THREAT OF
HEAVIER RAIN ON MONDAY STILL APPEARS ON TRACK. EXPECT NEARLY STEADY
TEMPS IN THE 60-65 RANGE OVER MUCH OF THE AREA FOR THE REST OF THE
NIGHT. -GIH
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 235 PM SUNDAY...
MONDAY AND MONDAY NIGHT:
BROAD UPPER-LEVEL TROUGH IN PLACE FROM THE GREAT LAKES TO THE LOWER
MS VALLEY WILL GET REINFORCED BY SHORTWAVE TROUGH DIVING SOUTHEAST
ALONG THE SOUTHERN ROCKIES AND INTO THE SOUTHERN PLAINS ON MONDAY.
MEANWHILE...WEAK FRONTAL ZONE AND ASSOCIATED WAVE OF LOW PRESSURE
OVER THE SOUTHERN APPALACHIANS WILL INCH SLOWLY EASTWARD INTO THE
WESTERN CAROLINAS THROUGH MONDAY NIGHT. SHORTWAVE ENERGY IS EXPECTED
TO EJECT EAST-NORTHEASTWARD ACROSS THE AREA IN THE SWLY FLOW ALOFT
DOWNSTREAM OF THE BROAD TROUGH AND WITHIN THE ANOMALOUSLY HIGH (2
STD ABOVE NORMAL)PWAT AIRMASS LYING ALONG AND EAST OF THE WEAK
FRONTAL ZONE ACROSS WESTERN NC. DAYTIME HEATING OF THE MOIST
BOUNDARY LAYER WILL SUPPORT NUMEROUS TO WIDESPREAD SHOWERS/TSTMS
MONDAY AFTERNOON/EVENING...WITH AN AXIS OF MODERATE TO HEAVY RAINFALL
NOT BUDGING VERY MUCH...CENTERED ALONG AND ON THE EASTERN SLOPES OF
THE APPALACHIANS AND POTENTIALLY EXTENDING EAST INTO THE WESTERN
PIEDMONTS OF NC AND VIRGINIA. WHILE THERE REMAINS SOME UNCERTAINTY
WRT TO THE TIMING OF THE EMBEDDED SHORTWAVE IMPULSES...MODEL
CONSENSUS INDICATES THAT THE HEAVY RAINFALL AXIS AND HIGHEST WILL
SHIFT EASTWARD MONDAY NIGHT...REACHING THE COASTAL SECTIONS BY
DAYBREAK TUESDAY.
SEVERE WEATHER THREAT:
WHILE MOIST ADIABATIC PROFILES WILL SUPPORT WEAK MID-LEVEL LAPSE
RATES AND INSOLATION SHOULD BE GREATLY IMPEDED BY WIDESPREAD
CLOUDS...MODELS STILL SUGGEST THE POTENTIAL FOR WEAK TO MODERATE
DESTABILIZATION COULD DEVELOP MONDAY AFTERNOON. UNIDIRECTIONAL SWLY
FLOW OF 25-30 KT COULD SUPPORT A CLUSTER OR TWO OF STRONG TO SEVERE
THUNDERSTORMS THAT COULD PRODUCE DAMAGING WET MICROBURSTS. WITH LOSS
OF DAYTIME HEATING ...THE THREAT OF SEVERE WEATHER SHOULD BE ON THE
WANE MONDAY NIGHT AS THE AIRMASS COOLS/STABILIZES.
HEAVY RAIN THREAT:
WHILE IT WILL GREATLY DEPEND ON HOW MUCH RAINFALL WE SEE THIS
AFTERNOON AND TONIGHT...THE WESTERN PIEDMONT/TRIAD AREA COULD
POTENTIALLY ADD ANOTHER 1 TO 2 INCHES MONDAY AND MONDAY NIGHT TO
WHATEVER WE SEE TONIGHT. 3 HOUR FLASH FLOOD GUIDANCE TODAY FOR THOSE
AREAS ARE AROUND 3.0"...BUT IF WE RECEIVE AN INCH OF RAIN
TONIGHT...IT SHOULD LOWER THE GUIDANCE SIGNIFICANTLY...CLOSE TO THE
TWO INCH THRESHOLD. LATER SHIFTS MAY NEED TO CONSIDER A FLASH FLOOD
WATCH FOR THE WESTERN PIEDMONT MONDAY AFTERNOON/MONDAY NIGHT. EAST
OF THE TRIAD...EXPECT AVERAGE RAINFALL AMOUNTS OF 0.50-1.0"... WITH
ONLY LOCALIZED/URBAN FLOODING EXPECTED.
TEMPERATURES:
HIGHS MONDAY WILL DEPEND ON SHOWER/STORM COVERAGE AND WHETHER WE
WILL MANAGE TO SEE ANY BREAKS IN THE EAST. AFTERNOON HIGHS RANGING
FROM AROUND 70 WEST TO AROUND 80 EAST. LOWS MONDAY NIGHT AGAIN
IN THE 60S. -CBL
TUESDAY AND TUESDAY NIGHT:
ONGOING SHOWERS AND STORMS TUESDAY MORNING SHOULD BE MOVING INTO THE
COASTAL PLAIN AS THE AXIS OF DEEPEST MOISTURE FINALLY SHIFTS TOWARD
THE COAST. HOWEVER...THE WEAK SURFACE FRONT IS FORECAST LINGER BACK
TO THE WEST ALONG THE MOUNTAINS WHILE THE UPPER TROUGH ENERGY
CONTINUES TO EVOLVE WEST OF THE MOUNTAINS....EVENTUALLY PUSHING INTO
THE AREA TUESDAY EVENING. WITH SLIGHTLY DRIER AIR FORECAST TO
OVERSPREAD CENTRAL NC...SOME BREAKS IN CLOUD COVER AND STRONGER
DESTABILIZATION ARE EXPECTED. AHEAD OF THE UPPER TROUGH... THE MAY
CONTINUE TO BE SUBTLE DISTURBANCES ALOFT MOVING ACROSS THE
PERSISTENT WARM AND MOIST AIRMASS...LEADING TO A SCATTERED SHOWERS
AND STORMS BY TUESDAY AFTERNOON. THE NAM IS STRONGEST AND SHOWING A
STOUT VORT MAX LIFTING ACROSS THE AREA DURING PEAK HEATING. A
TIGHTER HEIGHT FIELD ASSOCIATED WITH THIS FEATURE LEADS TO STRONGER
DEEP LAYER SHEAR FORECAST BY THE NAM...BUT THE NAM SEEMS TO BE
OVERDONE. THE GFS AND ECMWF SHOW MORE A MORE DIFFUSE WAVE AND
ONLY 20-25KT OF 0-6KM BULK SHEAR...WHICH IS SUPPORTED BY MOST SREF
MEMBERS. THERE IS CONSIDERABLE SPREAD AMONG SREF MEMBERS REGARDING
INSTABILITY...BUT MODIFIED GFS SOUNDINGS FOR TEMPS IN THE UPPER 70S
TO LOWER 80S AND DEWPOINTS IN THE LOWER 60S SHOW 500-1000 J/KG OF
MLCAPE. A FEW ISOLATED SEVERE STORMS MAY BE POSSIBLE...BUT IF THE
UPPER WAVE IS STRONGER...AS THE NAM FORECASTS...THEN THE SEVERE
POTENTIAL WILL BE GREATER. HIGHS 77-82.
AS THE SURFACE FRONT AND MAIN LOW LEVEL CONVERGENCE ZONE PUSHES INTO
THE CWA TUESDAY EVENING...ISOLATED SHOWERS AND STORMS MAY CONTINUE
INTO THE OVERNIGHT HOURS. THE FRONT WILL CONTINUE TO BE RATHER SLOW
MOVING...AND LOWS SHOULD BE FAIRLY PERSISTENT IN THE UPPER 50S TO
LOWER 60S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 310 PM SUNDAY...
A SLOW MOVING...WEAK COLD FRONT IS FORECAST TO FINALLY MOVE INTO
CENTRAL NC BY WEDNESDAY MORNING...AS A POSITIVELY TITLED UPPER
TROUGH EXTENDING FROM THE GREAT LAKES INTO THE DEEP SOUTH BEGINS TO
DRIFT EAST ACROSS THE APPALACHIANS MOUNTAINS. DEEP MOISTURE WILL
BEGIN TO TREND DOWNWARD FROM WEST TO EAST AS THE TROUGH MOVES INTO
THE AREA...AND THUS POPS WILL BE INCREASINGLY FOCUSED OVER THE
EASTERN CWA WEDNESDAY AND THURSDAY. TEMPS SHOULD GENERALLY RUN
RIGHT AROUND NORMAL (HIGHS AROUND 80 AND LOWS IN THE MID TO UPPER
50S) IF NOT A SLIGHTLY BELOW NORMAL WITH WEAK TROUGHING ALONG THE
EAST COAST.
THEN...AS ENERGY SWINGING ACROSS THE GREAT LAKES LEAVES
THE SOUTHERN END OF THE UPPER TROUGH BEHIND...MODELS DIVERGE
REGARDING HOW THE TROUGH WILL EVOLVE AS IT DRIFTS EAST TOWARD THE
GA/SC COAST. THE 12Z GFS NEVER QUITE CLOSES OFF AN UPPER LOW AND
ALLOWS THE TROUGH TO BE SWEPT OFF TO THE NORTHEAST AS NORTHERN
STREAM ENERGY SWINGS ACROSS NEW ENGLAND. THE 00Z ECMWF HAD SHOWN A
VERY INTERESTING SOLUTION WITH THE UPPER LOW DEVELOPING ALONG THE
SOUTHEAST COAST AND A POSSIBLE SUBTROPICAL-LIKE LOW THAT DRIFTED
NORTHWEST INTO NC/SC OVER THE WEEKEND. THE 12Z ECMWF RUN SHOWS THE
UPPER LOW FURTHER OFFSHORE AND LITTLE IMPACT OVER NC. THERE IS A
LOT OF SPREAD AMONG GFS AND ECWMF ENSEMBLE MEMBERS...SO CONFIDENCE
IN SENSIBLE WEATHER IMPACTS NEXT WEEKEND IS LOW AT THE MOMENT....BUT
WE WILL KEEP THE FORECAST DRY FOR THIS PACKAGE.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 1205 AM MONDAY...
24-HR TAF PERIOD:
DETERIORATING CONDITIONS ARE EXPECTED THIS MORNING...WITH LITTLE (IF
ANY) IMPROVEMENT THROUGH THE REMAINDER OF THE TAF PERIOD. AN UPPER
LEVEL TROUGH AND ASSOCIATED SURFACE LOW PRESSURE SYSTEM WILL
CONTINUE TO SLOWLY APPROACH THE CAROLINAS FROM THE WEST TODAY AND
TONIGHT. PERIODS OF SHOWERS ARE EXPECTED THIS MORNING...WITH
CEILINGS LOWERING TO IFR/LIFR AT THE INT/GSO TERMINALS AND MVFR/IFR
AT THE RDU/FAY/RWI TERMINALS. PERIODS OF SHOWERS AND THUNDERSTORMS
ARE EXPECTED THIS AFTERNOON...WITH ONLY A MARGINAL IMPROVEMENT IN
CEILINGS DURING PEAK HEATING. EXPECT CEILINGS AND VISBYS TO DECREASE
INTO THE IFR/LIFR RANGE EVERYWHERE BETWEEN SUNSET THIS EVENING AND
SUNRISE TUE MORNING. SE/SSE WINDS AT ~5 KT WILL PERSIST THROUGH
SUNRISE...WITH SE/SSE WINDS INCREASING TO ~10 KT BY THIS AFTERNOON.
LOOKING AHEAD:
LINGERING LOW-LEVEL MOISTURE COMBINED WITH ANOTHER UPPER LEVEL
TROUGH APPROACHING THE AREA FROM THE NORTHWEST WILL ALLOW ADVERSE
AVIATION CONDITIONS TO PERSIST TUE/TUE NIGHT...WITH SCATTERED
SHOWERS AND THUNDERSTORMS POSSIBLE AT ALL TERMINALS. IMPROVING
CONDITIONS ARE EXPECTED WED/WED NIGHT AS THE UPPER LEVEL TROUGH AND
ASSOCIATED SURFACE LOW PROGRESS CLOSER TOWARD THE SOUTHEAST COAST...
THOUGH MVFR CONDITIONS APPEAR LIKELY IN MANY LOCATIONS. UNCERTAINTY
INCREASES TOWARD THE LATTER PORTION OF THE WEEK. AT THIS TIME...
VFR/MVFR CEILINGS (2500-4500 FT AGL) ARE EXPECTED THU/FRI. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...HARTFIELD
SHORT TERM...CBL/BLS
LONG TERM...BLS
AVIATION...VINCENT
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1155 PM CDT SUN MAY 13 2012
.AVIATION...
FOR THE 06Z TAFS...ONGOING SHOWERS AND THUNDERSTORMS WERE NORTH AND
WEST OF THE TERMINALS AND ARE EXPECTED TO STAY OUTSIDE OF THE
VICINITY OF THE TERMINALS OVERNIGHT. HOWEVER ANOTHER ROUND OF
SHOWERS CAN IMPACT THE KAMA/KDHT TERMINALS BY 11-12Z WHILE THINK
SHOWERS WILL NOT AFFECT THE KGUY TERMINAL. HAVE KEPT CONDITIONS VFR
THROUGH THE FORECAST PERIOD ALTHOUGH MODERATE TO HEAVY RAINFALL CAN
BRIEFLY REDUCE VISBYS TO MVFR. AS THE UPPER-LEVEL TROUGH MOVES INTO
WEST TX ON MONDAY...SKIES SHOULD BEGIN TO DIMINISH WITH ONLY FEW TO
SCT MID CLOUDS BY 20-00Z.
CLK
&&
.PREV DISCUSSION... /ISSUED 655 PM CDT SUN MAY 13 2012/
AVIATION...
FOR THE 00Z TAFS...ONGOING SHOWERS AND THUNDERSTORMS CONTINUE TO
IMPACT THE KAMA TERMINAL WHERE MODERATE TO HEAVY RAIN HAS REDUCED
VISBYS DOWN TO BELOW 2 MILES BRIEFLY. CURRENT RADAR IMAGERY SHOWS
STORMS SLOWLY MOVING EAST...SO EXPECT TSRA TO IMPACT KAMA THROUGH
01Z. HAVE INSERTED A TEMPO GROUP WITH MVFR VISBYS AT 2SM THROUGH THEN
AS ADDITIONAL HEAVY RAINFALL CAN ACCOMPANY THESE STORMS. KDHT IS
CURRENTLY REPORTING MVFR VISBYS IN LIGHT FOG WHICH SHOULD CONTINUE
THIS EVENING. STORMS CONTINUE TO DEVELOP ACROSS THE EASTERN PLAINS
0F CO/NM AS UPPER LIFT PROVIDED BY AN UPPER SHORTWAVE TROUGH IN THE
FOUR CORNERS AREA COMBINES WITH MOIST LOW-LEVEL UPSLOPE FLOW. HAVE
CARRIED -SHRA TONIGHT AT THE TERMINALS AS THESE SHOWERS WILL
CONTINUE TO MOVE TO THE EAST. OUTSIDE OF ANY STRONGER SHOWER THAT MAY
PRODUCE MODERATE OR HEAVY RAINFALL THAT CAN REDUCE BRIEFLY REDUCE
VISBYS...EXPECT VFR CONDITIONS THROUGH THE TAF FORECAST PERIOD. THE
UPPER SHORTWAVE TROUGH IS EXPECTED TO CONTINUE TO DROP SOUTH AND MOVE
INTO WEST TX BY MONDAY AFTERNOON. THUS EXPECT -SHRA MONDAY MORNING
AND AFTERNOON WITH SKIES THINNING TOWARD THE END OF THE FORECAST
PERIOD...PARTICULARLY AT KGUY/KDHT.
CLK
PREV DISCUSSION... /ISSUED 332 PM CDT SUN MAY 13 2012/
DISCUSSION...
PRIMARY FOCUS IS ON PRECIPITATION CHANCES THROUGH MONDAY.
AFTERNOON WATER VAPOR IMAGERY SHOWED A MID/UPPER-LEVEL SHORTWAVE
TROUGH SINKING SOUTHEAST ACROSS EASTERN UT TOWARDS THE FOUR CORNERS
REGION. MID TO UPPER-LEVEL FORCING AHEAD OF THIS SHORTWAVE HAS
COMBINED WITH DAYTIME HEATING/DESTABILIZATION AND LOW-LEVEL UPSLOPE
FLOW OVER EASTERN CO AND NM TO GENERATE SHOWERS AND THUNDERSTORMS.
THE GREATEST CONVECTIVE COVERAGE IS CURRENTLY ACROSS NORTHEAST NM
WORKING INTO THE SOUTHWEST TX PANHANDLE...BUT ADDITIONAL SCATTERED
SHOWERS AND THUNDERSTORMS HAVE DEVELOPED FARTHER EAST ACROSS THE
PANHANDLES DUE TO THE COMBINATION OF AFTERNOON DESTABILIZATION AND
BROADER SCALE LIFT AHEAD OF THE SHORTWAVE.
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO IMPACT THE AREA THIS
EVENING AND OVERNIGHT. THE MID/UPPER-LEVEL SHORTWAVE TROUGH WILL
CONTINUE TO DIVE SOUTHEAST...REACHING NORTHERN/CENTRAL NM BY EARLY
MONDAY MORNING. DIFFLUENT/DIVERGENT FLOW ALOFT AHEAD OF THIS WAVE
WILL CONTINUE TO SUPPORT CONVECTION PROPAGATING EAST/SOUTHEAST OUT OF
NM AND CO THIS EVENING AND OVERNIGHT. BEST DYNAMICS WILL BE FOCUSED
ACROSS THE SOUTHWEST HALF OF THE AREA AND HAVE ALIGNED POPS
ACCORDINGLY. ALSO SOME WEAK ISENTROPIC LIFT EVIDENT ON THE 305K THETA
SURFACE ACROSS THE SOUTHWEST TX PANHANDLE THIS EVENING TO FURTHER AID
CONVECTION. LATEST LAPS AND RUC ANALYSIS DATA SHOW MLCAPES IN THE
500-1000 J/KG RANGE ACROSS THE WESTERN PANHANDLES WITH LESSER VALUES
TO THE EAST AND DEEP LAYER SHEAR AROUND 30-35 KTS IN THE SOUTHWEST
TX PANHANDLE...DECREASING TO THE NORTHEAST. THUS COULD SEE A FEW
STRONG STORMS THROUGH THIS EVENING CAPABLE OF PRODUCING SMALL HAIL
AND GUSTY WINDS...BUT NOT REALLY ANTICIPATING ANY SEVERE WEATHER
/ALTHOUGH AN ISOLATED MARGINALLY SEVERE STORM ACROSS THE SOUTHWEST CAN/T
BE RULED OUT/. COULD ALSO SEE SOME LOCALLY HEAVY RAIN GIVEN PWATS IN
THE THREE QUARTERS OF AN INCH TO ONE INCH RANGE AND SOME TRAINING OF
STORMS POSSIBLE. BETTER RAIN CHANCES LOOK TO GRADUALLY SHIFT
SOUTH/SOUTHWEST OF THE AREA LATE TONIGHT IN ASSOCIATION WITH STRONGER
DIVERGENCE ALOFT...AND ALSO AS THE LLJ AND LOW-LEVEL ISENTROPIC LIFT
FOCUS TO OUR SOUTHWEST.
RAIN CHANCES LINGER INTO MONDAY...BUT WILL GRADUALLY END FROM NORTH
TO SOUTH THROUGH THE DAY AS THE SHORTWAVE CONTINUES TO DIVE SOUTHEAST
TO SOUTHEAST NM/SOUTHWEST TX BY EARLY MONDAY EVENING. BETTER RAIN
CHANCES WILL BE FOCUSED ACROSS THE SOUTHERN HALF OF THE CWA ON
MONDAY. WEAKER INSTABILITY AND SHEAR SHOULD PRECLUDE ANY STRONG OR
SEVERE STORMS. WILL ALSO SEE THE COOLEST TEMPS IN THE SOUTH ON MONDAY
DUE TO LINGERING CLOUDS/PRECIP...WITH HIGHS FORECAST TO RANGE FROM
THE UPPER 60S SOUTHWEST TO MID/UPPER 70S NORTH.
DRY CONDITIONS ARE THEN FORECAST BEGINNING MONDAY NIGHT AS SHORTWAVE
UPPER RIDGING BUILDS EAST ACROSS THE SOUTHERN AND CENTRAL ROCKIES.
TEMPS WILL BEGIN TO REBOUND ON TUESDAY DUE TO RISING HEIGHTS...A
RETURN OF WEAK SOUTHERLY WINDS...AND INCREASED SUNSHINE...WITH HIGHS
CLIMBING BACK INTO THE UPPER 70S TO LOWER 80S. A DAMPENING MID-LEVEL
SHORTWAVE WILL WORK ACROSS THE CENTRAL ROCKIES AND PLAINS WEDNESDAY
AND WEDNESDAY NIGHT. THIS COULD POTENTIALLY SPAWN A FEW
SHOWERS/THUNDERSTORMS ACROSS THE NORTHERN PANHANDLES WEDNESDAY NIGHT.
HOWEVER...CHANCES LOOK LOW AT THIS TIME AS BETTER DYNAMICS WILL STAY
TO OUR NORTH AND COME ACROSS AT NIGHT...BY WHICH TIME ELEVATED
INSTABILITY LOOKS MINIMAL. THUS KEPT A DRY FORECAST FOR NOW. THE LEE
TROUGH WILL DEEPEN ON WEDNESDAY...WITH RESULTANT BREEZY SOUTHWEST
WINDS FURTHER CONTRIBUTING TO THE WARM UP.
A ZONAL FLOW/BROAD FLAT RIDGING LATE THIS WEAK WILL TRANSITION TO
SOUTHWESTERLY OVER THE WEEKEND AS AN UPPER TROUGH WORKS ACROSS THE
INTERMOUNTAIN WEST AND ROCKIES EVENTUALLY INTO THE NORTHERN PLAINS.
THIS FLOW ALOFT WILL PROMOTE SURFACE LEE TROUGHING AND SOME
SHARPENING OF THE DRYLINE BY FRIDAY AND SATURDAY. HOWEVER IT
CURRENTLY LOOKS LIKE WARM TEMPS ALOFT AND A LACK OF UPPER FORCING /AS
THE TROUGH IS DEFLECTED WELL TO OUR NORTHWEST/ WILL MAKE IT TOUGH FOR
CONVECTION TO INITIATE. THUS WILL MAINTAIN A DRY FORECAST. ABOVE
NORMAL TEMPERATURES EXPECTED LATE WEEK INTO THE WEEKEND WITH HIGHS IN
THE MID 80S TO LOWER 90S. WILL HAVE TO KEEP AN EYE ON A POTENTIAL
COLD FRONT THAT MAY MOVE IN SUNDAY OR SUNDAY NIGHT.
KB
FIRE WEATHER...
NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE CURRENTLY
EXPECTED THROUGH THE WEEK. SOUTH/SOUTHWEST WINDS WILL INCREASE TO 15
TO 20 MPH ON WEDNESDAY AND RELATIVE HUMIDITIES MAY FALL TO 15 TO 20
PERCENT ACROSS THE FAR WESTERN PANHANDLES...BUT RECENT RAINFALL AND
RESULTANT GREEN-UP SHOULD MITIGATE ANY FIRE WEATHER CONCERNS. WARMER
TEMPERATURES WILL CONTINUE LATE WEEK INTO THE WEEKEND AND MINIMUM
RELATIVE HUMIDITIES WILL FALL TO 15 TO 20 PERCENT ACROSS WESTERN
AREAS. SOUTH/SOUTHWEST WINDS WILL BE BREEZY AT TIMES AND ELEVATED
FIRE WEATHER CONDITIONS COULD DEVELOP...BUT AGAIN RECENT RAINFALL AND
GREEN-UP WILL HELP MINIMIZE FIRE WEATHER CONCERNS.
KB
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
05/15
AREA FORECAST DISCUSSION
NWS ALBANY NY
649 AM EDT MON MAY 14 2012
.SYNOPSIS...
A STATIONARY FRONT WILL SERVE AS PATHWAY FOR SEVERAL DISTURBANCES TO
MOVE ALONG IT...STARTING TODAY...THROUGH TUESDAY NIGHT. TODAY
DISTURBANCES LOOK FAIRLY WEAK BRAINING SCATTERED TO NUMEROUS
SHOWERS. HOWEVER...A STRONGER DISTURBANCE TONIGHT WILL LIKELY BRING
A SOAKING POTENTIALLY HEAVY RAINFALL...TO MAINLY CENTRAL AND
SOUTHERN PORTIONS OF OUR REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 630 AM...BASED ON REGIONAL RADARS AND THE HRRR EXPERIMENTAL
MODEL...HAVE DECIDED TO GO BACK TO THE IDEA OF A MORE STEADIER RAIN
(ALBEIT LIGHT) THIS MORNING THEN A BREAK IN THE RAIN (SCATTERED
SHOWERS)DURING MUCH OF THE AFTERNOON. ACTUALLY...THE 00Z NAM
SUPPORTED THIS IDEA. THE 06Z GFS STILL BRINGS HEAVIER RAIN IN THIS
AFTERNOON...BUT AGAIN REGIONAL RADAR DOES NOT SUPPORT THIS IDEA.
TINKERED WITH THE QPF BUT NOT MUCH TO REFLECT THIS MODIFICATION IN
THINKING.
EITHER WAY...IT WILL REMAIN DAMP AND PROBABLY WILL SEE SCATTERED
SHOWERS OR PATCHY DRIZZLE THIS AFTERNOON ALONG WITH LOTS OF CLOUDS.
NO OTHER CHANGES OTHER THEN TO RE-TOOL THE HOURLY GRIDS...WHICH WERE
IN PRETTY GOOD SHAPE.
RAINFALL AMOUNTS LOOK TO BE A QUARTER TO MAYBE HALF AN
INCH...LIGHTER AMOUNTS UNDER QUARTER OF AN INCH TO THE NORTHWEST.
THE CLOUDS AND SHOWERS SHOULD KEEP TEMPERATURES DOWN
TODAY...GENERALLY HELD TO THE 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
CONFIDENCE IS NOW HIGHER THAT THE AXIS OF HEAVY RAIN TONIGHT THROUGH
TUESDAY NIGHT WILL GENERALLY RUN FROM THE CATSKILLS...NORTHEAST
ACROSS THE GREATER CAPITAL DISTRICT INTO THE SOUTHERN VERMONT.
THE SYNOPTIC SETUP DOES NOT REALLY LOOK LIKE A CLASSICAL HEAVY
RAINFALL EVENT...BUT CERTAINLY A MODERATE ONE. THE UPPER AIR TROUGH
IS SOMEWHAT WEAK. THERE WILL BE A LOW LEVEL JET...POSSIBLY
INCREASING TO 40KTS TRANSPORTING PWAT VALUES APPROACHING AN INCH AND
HALF FROM ALBANY SOUTHWARD. THE FLOW LOOKS TO BE SSE TO
SOUTHERLY...THROUGHOUT THE COLUMN.
A STRONGER DISTURBANCE...STILL DEVELOPING DOWN IN THE TENNESSEE
VALLEY...WILL BE THE ONE TO BRING MORE SIGNIFICANT RAINFALL TONIGHT
THROUGH TUESDAY NIGHT AS OUR CENTRAL AND EVENTUALLY SOUTHEAST AREAS
COME UNDERNEATH MID LEVEL FRONTOGENESIS AND ASSISTANCE FROM
DIVERGENCE ALOFT UNDERNEATH THE LEFT ENTRANCE OF AN UPPER LEVEL JET.
THE TOTAL QPF AMOUNT IS STILL SOMEWHAT UNCERTAIN AS THERE IS SOME
DISPARITY WITH THE CANADIAN AND EUROPEAN MODELS GENERALLY GIVING A
TOTAL RAINFALL IN THE 1-2 INCH RANGE...WHILE THE GFS AND NAM WERE
MORE IN THE 2-3+ INCH RANGE.
FOR NOW...PER HPC...HAVE LEANED WITH THE AMERICAN MODELS. MORE ABOUT
THE QPF AND WHAT IT COULD FOR OUR HYDROLOGICAL SERVICE AREAS (HSA)
CAN BE FOUND IN OUR HYDROLOGY SECTION.
SHOWALTER INDICES REMAINED POSITIVE WITH VERY LITTLE IF ANY SURFACE
INSTABILITY THROUGH TONIGHT. ON TUESDAY SHOWALTER VALUES LOOK TO
APPROACH ZERO SO WE WILL INCLUDE A SLIGHT CHANCE OF THUNDER.
THE UPPER LEVEL TROUGH LOOKS TO BEGIN TO SLOWLY SHIFT EASTWARD
TUESDAY TAKING THE SURFACE FRONT WITH IT AS IT GETS A KICK FROM
ANOTHER UPSTREAM DISTURBANCE. THE MODERATE TO HEAVY RAIN WILL SHIFT
EASTWARD AS WELL...AND FINALLY END.
HOWEVER...THE "KICKER"...ANOTHER COLD FRONT...COULD PRODUCE A ROUND
OF SHOWERS AND EVEN THUNDERSTORMS OF ITS OWN WEDNESDAY. THIS LOOKS
TO BE A MUCH FASTER MOVING SYSTEM SO ANY PRECIPITATION WITH IT
SHOULD NOT BE NEARLY AS HEAVY OR PROLONGED.
WITH CLOUDS AND RAIN...THERE WILL BE VERY LITTLE RANGE IN DIURNAL
TEMPERATURES THROUGH TUESDAY NIGHT. OVERNIGHT LOWS WILL BE IN THE
50S TO AROUND 60 AND DAYTIME HIGHS IN THE 60S.
BY WEDNESDAY...WE EXPECT BREAKS OF SUNSHINE MIDDAY AND AFTERNOON
ALONG WITH CONTINUE H850 TEMPERATURES NOT FAR FROM +10C.
THEREFORE...LOOK FOR A BOUNCE IN TEMPERATURES AS THEY RISE BACK
THROUGH THE 70S...POSSIBLY TOUCHING 80 IN SOME OF THE WARMEST SPOTS
MAINLY SOUTH OF ALBANY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A LARGE HIGH PRESSURE SYSTEM WILL BEGIN BUILDING EAST FROM THE GREAT
LAKES REGION WEDNESDAY NIGHT...AND BE OVER THE REGION THURSDAY NIGHT
AND FRIDAY. DURING THE WEEKEND THE HIGH WILL BECOME A STATIONARY
ELONGATED RIDGE THAT WILL STRETCH ALONG THE COAST FROM NEW ENGLAND
TO THE MID ATLANTIC STATES. THIS SHOULD KEEP FAIR AND DRY WEATHER
OVER THE FORECAST AREA FOR THE ENTIRE LONG TERM PERIOD. AT TIMES...
VARIOUS RUNS OF THE GFS/ECMWF HAVE INDICATED THE POSSIBILITY OF SCT
CONVECTION FRIDAY OR SATURDAY DUE TO SOME WEAK DISTURBANCES MOVING
INTO/THROUGH THE HIGH...BUT THEY HAVE NOT BEEN CONSISTENT WITH THIS
SO WILL CONTINUE TO IGNORE THE THREAT AND FORECAST DRY CONDITIONS
FOR NOW.
TEMPS WILL START THE LONG TERM PERIOD ON THE COOL SIDE...ESPECIALLY
AT NIGHT...BUT THEN WARM TO ABOVE NORMAL READINGS BY FRIDAY AND THE
WEEKEND. LOWS WEDNESDAY NIGHT WILL BE IN THE UPPER 30S AND 40S.
HIGHS THURSDAY IN THE 60S TO LOWER 70S. LOWS THURSDAY NIGHT IN THE
MID 30S TO MID 40S. HIGHS FRIDAY IN THE MID 60S TO MID 70S. LOWS
FRIDAY NIGHT IN THE UPPER 30S AND 40S. HIGHS SATURDAY IN THE UPPER
60S AND 70S. LOWS SATURDAY NIGHT IN THE 40S AND LOWER 50S...AND
HIGHS SUNDAY IN THE 70S.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
A FRONTAL BOUNDARY WILL BE NEARLY STATIONARY SOMEWHERE ACROSS
SOUTHEAST NEW YORK AS LOW PRESSURE COMES SLOWLY UP THE APPALACHIAN
CHAIN TODAY THROUGH TUESDAY. INITIALLY WIDESPREAD LIGHT RAIN WILL BE
OVER THE REGION THIS MORNING WITH A BREAK IN THE PCPN FOR PART OF
THIS AFTERNOON POSSIBLE AS RADAR IMAGERY AT 630 AM SHOWS A LARGE
AREA OF LITTLE OR NO RAIN OVER ERN PA AND NJ. AS A RESULT...MAINLY
VFR CONDITIONS EXPECTED AT THE KGFL/KALB/KPOU TAF SITES FOR MOST OF
TODAY...WHILE MVFR/IFR VSBY CONDITIONS WILL OCCUR AT KPSF WHERE THE
LOWER VSBYS ARE PRIMARILY DUE TO FOG (CIGS WILL BE MAINLY
VFR).
DURING THE EARLY AND MIDDLE PART OF THE AFTERNOON...AS NOTED ABOVE...
RAINFALL MAY END FOR A TIME OR BECOME SCATTERED. CONDITIONS LIKELY
TO BE MAINLY VFR AT ALL FOUR TAF SITES. HOWEVER...AS THE HEAVIER
RAIN ARRIVES LATER THIS AFTERNOON...CONDITIONS WILL LOWER TO MVFR AT
ALL THE TAF SITES INTO THE VENING...THEN ALL SITES WILL HAVE
WIDESPREAD IFR CONDITIONS BY MIDNIGHT...WITHTHE WIDESPREAD IFR
CONDITIONS CONTINUING THROUGH THE END OF THE TAF PERIOD AT 12Z
TUESDAY.
SURFACE WINDS WILL BE CALM OR LIGHT NORTHERLY (5 KTS OR LESS) TO
START THE TAF PERIOD...THEN SWITCH TO SOUTHERLY LATER THIS MORNING
AND PICK UP TO 5 TO 10 KTS DURING THE AFTERNOON. WINDS WILL REMAIN
SOUTHERLY TONIGHT...BUT DECREASE TO 5 KTS OR LESS.
.OUTLOOK...
TUE-TUE NGT...MVFR/IFR RA LIKELY.
WED...MAINLY VFR...SCT SHRA.
WED NGT-FRI...VFR...NO WX.
&&
.FIRE WEATHER...
DAMP CONDITIONS WILL PREVAIL TODAY IN MOST SECTIONS WITH SCATTERED
TO NUMEROUS SHOWERS. AREAS ACROSS THE ADIRONDACKS...MOHAWK VALLEY
AND LITCHFIELD COUNTY WILL LIKELY SEE RAINFALL AMOUNTS UNDER A
QUARTER OF AN INCH TODAY...WHILE OTHER REGIONS WILL HAVE A QUARTER
TO UPWARDS OF NEARLY HALF AN INCH.
RH VALUES WILL REMAIN ELEVATED TODAY...GENERALLY NO LOWER THAN 60-75
PERCENT.
A SOAKING RAIN IS IN THE OFFING LATER TONIGHT THROUGH TUESDAY NIGHT
WITH RAINFALL AMOUNTS RANGING FROM AROUND THREE QUARTERS OF INCH
ACROSS THE ADIRONDACKS...TO 1-3 INCHES ACROSS THE REMAINDER OF THE
REGION.
SOME DRYING IS EXPECTED WEDNESDAY...HOWEVER ADDITIONAL SHOWERS ARE
POSSIBLE.
MUCH DRIER WEATHER LOOKS LIKELY THURSDAY INTO NEXT WEEKEND.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED THROUGH TODAY.
IT STILL LOOKS AS IF TODAY/S RAINFALL WILL GENERALLY RANGE FROM A
QUARTER TO HALF AN INCH...WITH LIGHTER AMOUNTS UNDER A QUARTER OF AN
INCH ACROSS THE ADIRONDACKS...MOHAWK VALLEY AND LITCHFIELD COUNTY.
THIS RAIN WILL PRODUCE MINOR RISES ON STREAMS AND RIVERS AT THE
MOST.
THEN...IT LOOKS OF AS IF A MORE STEADY AND POTENTIALLY HEAVIER RAIN
WILL ENSUE TONIGHT INTO EARLY TUESDAY NIGHT. RAINFALL AMOUNTS STILL
LOOK TO BE IN ONE TO THREE INCH RANGE...EXCEPT A LITTLE LESS ACROSS
PORTIONS OF OUR ADIRONDACKS.
ASSUMING THIS RAINFALL AMOUNT WORKS OUT...THE ADIRONDACKS SHOULD
ONLY SEE ONLY ADDITIONAL MINOR RISES ON STREAMS AND RIVERS. OTHER
REGIONS WILL SEE MORE SIGNIFICANT WITHIN BANK RISES ON RIVERS AND
STREAMS...WITH MANY OF THEM POSSIBLY REACHING ACTION STAGE.
AGAIN...ASSUMING WE HAVE A GOOD HANDLE OF THE QPF AMOUNTS...FLOODING
IS NOT LIKELY AND THEREFORE NO FLOOD WATCHES WERE ISSUED WITH THIS
RAINFALL EVENT AT THIS TIME. IT WOULD BE A GOOD IDEA TO CHECK BACK
ON THE HYDROLOGY STATUS DURING THE NEXT COUPLE OF DAYS.
NEVERTHELESS...PONDING OF WATER IS A GOOD BET...MAINLY IN AREAS OF
POOR DRAINAGE AS RAINFALL RATES COULD REACH UP TO A QUARTER OF AN
INCH AN HOUR AT TIMES LATE TONIGHT INTO EARLY TUESDAY NIGHT.
SOME ADDITIONAL RAINFALL IS POSSIBLE ON WEDNESDAY WITH ANOTHER
FASTER MOVING COLD FRONT...BUT AT THIS POINT RIVER BASIN QPF WITH
THIS SYSTEM LOOKS TO BE UNDER A QUARTER OF AN INCH.
DRIER WEATHER IS THEN FORECAST LATE IN THE WEEK AND WEEKEND WHICH
WOULD ALLOW RIVERS AND STREAMS TO RECEDE BACK TO MORE SEASONAL
LEVELS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...HWJIV
LONG TERM...HWJIV
AVIATION...GJM
FIRE WEATHER...HWJIV
HYDROLOGY...HWJIV
AREA FORECAST DISCUSSION
NWS ALBANY NY
635 AM EDT MON MAY 14 2012
.SYNOPSIS...
A STATIONARY FRONT WILL SERVE AS PATHWAY FOR SEVERAL DISTURBANCES TO
MOVE ALONG IT...STARTING TODAY...THROUGH TUESDAY NIGHT. TODAY
DISTURBANCES LOOK FAIRLY WEAK BRAINING SCATTERED TO NUMEROUS
SHOWERS. HOWEVER...A STRONGER DISTURBANCE TONIGHT WILL LIKELY BRING
A SOAKING POTENTIALLY HEAVY RAINFALL...TO MAINLY CENTRAL AND
SOUTHERN PORTIONS OF OUR REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 630 AM...BASED ON REGIONAL RADARS AND THE HRRR EXPERIMENTAL
MODEL...HAVE DECIDED TO GO BACK TO THE IDEA OF A MORE STEADIER RAIN
(ALBEIT LIGHT) THIS MORNING THEN A BREAK IN THE RAIN (SCATTERED
SHOWERS)DURING MUCH OF THE AFTERNOON. ACTUALLY...THE 00Z NAM
SUPPORTED THIS IDEA. THE 06Z GFS STILL BRINGS HEAVIER RAIN IN THIS
AFTERNOON...BUT AGAIN REGIONAL RADAR DOES NOT SUPPORT THIS IDEA.
TINKERED WITH THE QPF BUT NOT MUCH TO REFLECT THIS MODIFICATION IN
THINKING.
EITHER WAY...IT WILL REMAIN DAMP AND PROBABLY WILL SEE SCATTERED
SHOWERS OR PATCHY DRIZZLE THIS AFTERNOON ALONG WITH LOTS OF CLOUDS.
NO OTHER CHANGES OTHER THEN TO RE-TOOL THE HOURLY GRIDS...WHICH WERE
IN PRETTY GOOD SHAPE.
RAINFALL AMOUNTS LOOK TO BE A QUARTER TO MAYBE HALF AN
INCH...LIGHTER AMOUNTS UNDER QUARTER OF AN INCH TO THE NORTHWEST.
THE CLOUDS AND SHOWERS SHOULD KEEP TEMPERATURES DOWN
TODAY...GENERALLY HELD TO THE 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
CONFIDENCE IS NOW HIGHER THAT THE AXIS OF HEAVY RAIN TONIGHT THROUGH
TUESDAY NIGHT WILL GENERALLY RUN FROM THE CATSKILLS...NORTHEAST
ACROSS THE GREATER CAPITAL DISTRICT INTO THE SOUTHERN VERMONT.
THE SYNOPTIC SETUP DOES NOT REALLY LOOK LIKE A CLASSICAL HEAVY
RAINFALL EVENT...BUT CERTAINLY A MODERATE ONE. THE UPPER AIR TROUGH
IS SOMEWHAT WEAK. THERE WILL BE A LOW LEVEL JET...POSSIBLY
INCREASING TO 40KTS TRANSPORTING PWAT VALUES APPROACHING AN INCH AND
HALF FROM ALBANY SOUTHWARD. THE FLOW LOOKS TO BE SSE TO
SOUTHERLY...THROUGHOUT THE COLUMN.
A STRONGER DISTURBANCE...STILL DEVELOPING DOWN IN THE TENNESSEE
VALLEY...WILL BE THE ONE TO BRING MORE SIGNIFICANT RAINFALL TONIGHT
THROUGH TUESDAY NIGHT AS OUR CENTRAL AND EVENTUALLY SOUTHEAST AREAS
COME UNDERNEATH MID LEVEL FRONTOGENESIS AND ASSISTANCE FROM
DIVERGENCE ALOFT UNDERNEATH THE LEFT ENTRANCE OF AN UPPER LEVEL JET.
THE TOTAL QPF AMOUNT IS STILL SOMEWHAT UNCERTAIN AS THERE IS SOME
DISPARITY WITH THE CANADIAN AND EUROPEAN MODELS GENERALLY GIVING A
TOTAL RAINFALL IN THE 1-2 INCH RANGE...WHILE THE GFS AND NAM WERE
MORE IN THE 2-3+ INCH RANGE.
FOR NOW...PER HPC...HAVE LEANED WITH THE AMERICAN MODELS. MORE ABOUT
THE QPF AND WHAT IT COULD FOR OUR HYDROLOGICAL SERVICE AREAS (HSA)
CAN BE FOUND IN OUR HYDROLOGY SECTION.
SHOWALTER INDICES REMAINED POSITIVE WITH VERY LITTLE IF ANY SURFACE
INSTABILITY THROUGH TONIGHT. ON TUESDAY SHOWALTER VALUES LOOK TO
APPROACH ZERO SO WE WILL INCLUDE A SLIGHT CHANCE OF THUNDER.
THE UPPER LEVEL TROUGH LOOKS TO BEGIN TO SLOWLY SHIFT EASTWARD
TUESDAY TAKING THE SURFACE FRONT WITH IT AS IT GETS A KICK FROM
ANOTHER UPSTREAM DISTURBANCE. THE MODERATE TO HEAVY RAIN WILL SHIFT
EASTWARD AS WELL...AND FINALLY END.
HOWEVER...THE "KICKER"...ANOTHER COLD FRONT...COULD PRODUCE A ROUND
OF SHOWERS AND EVEN THUNDERSTORMS OF ITS OWN WEDNESDAY. THIS LOOKS
TO BE A MUCH FASTER MOVING SYSTEM SO ANY PRECIPITATION WITH IT
SHOULD NOT BE NEARLY AS HEAVY OR PROLONGED.
WITH CLOUDS AND RAIN...THERE WILL BE VERY LITTLE RANGE IN DIURNAL
TEMPERATURES THROUGH TUESDAY NIGHT. OVERNIGHT LOWS WILL BE IN THE
50S TO AROUND 60 AND DAYTIME HIGHS IN THE 60S.
BY WEDNESDAY...WE EXPECT BREAKS OF SUNSHINE MIDDAY AND AFTERNOON
ALONG WITH CONTINUE H850 TEMPERATURES NOT FAR FROM +10C.
THEREFORE...LOOK FOR A BOUNCE IN TEMPERATURES AS THEY RISE BACK
THROUGH THE 70S...POSSIBLY TOUCHING 80 IN SOME OF THE WARMEST SPOTS
MAINLY SOUTH OF ALBANY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A LARGE HIGH PRESSURE SYSTEM WILL BEGIN BUILDING EAST FROM THE GREAT
LAKES REGION WEDNESDAY NIGHT...AND BE OVER THE REGION THURSDAY NIGHT
AND FRIDAY. DURING THE WEEKEND THE HIGH WILL BECOME A STATIONARY
ELONGATED RIDGE THAT WILL STRETCH ALONG THE COAST FROM NEW ENGLAND
TO THE MID ATLANTIC STATES. THIS SHOULD KEEP FAIR AND DRY WEATHER
OVER THE FORECAST AREA FOR THE ENTIRE LONG TERM PERIOD. AT TIMES...
VARIOUS RUNS OF THE GFS/ECMWF HAVE INDICATED THE POSSIBILITY OF SCT
CONVECTION FRIDAY OR SATURDAY DUE TO SOME WEAK DISTURBANCES MOVING
INTO/THROUGH THE HIGH...BUT THEY HAVE NOT BEEN CONSISTENT WITH THIS
SO WILL CONTINUE TO IGNORE THE THREAT AND FORECAST DRY CONDITIONS
FOR NOW.
TEMPS WILL START THE LONG TERM PERIOD ON THE COOL SIDE...ESPECIALLY
AT NIGHT...BUT THEN WARM TO ABOVE NORMAL READINGS BY FRIDAY AND THE
WEEKEND. LOWS WEDNESDAY NIGHT WILL BE IN THE UPPER 30S AND 40S.
HIGHS THURSDAY IN THE 60S TO LOWER 70S. LOWS THURSDAY NIGHT IN THE
MID 30S TO MID 40S. HIGHS FRIDAY IN THE MID 60S TO MID 70S. LOWS
FRIDAY NIGHT IN THE UPPER 30S AND 40S. HIGHS SATURDAY IN THE UPPER
60S AND 70S. LOWS SATURDAY NIGHT IN THE 40S AND LOWER 50S...AND
HIGHS SUNDAY IN THE 70S.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
A FRONTAL BOUNDARY WILL BECOME STATIONARY SOMEWHERE ACROSS SOUTHEAST
NEW YORK AS LOW PRESSURE COMES SLOWLY UP THE APPALACHIAN CHAIN TO
INITIALLY BRING WIDESPREAD LIGHT RAIN INTO THE REGION BY AROUND
DAYBREAK. THE RAIN WILL REMAIN LIGHT THROUGH MOST OF MONDAY WITH
CIG/VSBY CONDITIONS REMAINING VFR AT THE KGFL/KALB/KPOU/KPSF TAF
SITES THROUGH JUST BEFORE NOON MONDAY. DURING MONDAY AFTERNOON
CONDITIONS WILL DETERIORATE TO MAINLY MVFR CIGS BUT VSBY WILL LIKELY
REMAIN 6 MILES OR MORE. BETWEEN 22Z AND 02Z PCPN WILL BECOME HEAVIER
AND VSBYS WILL LOWER TO AROUND 3 MILES WHILE CIGS DROP TO 1000 FEET
OR LESS. THE MVFR/IFR CONDITIONS WILL THEN PERSIST THROUGH THE END
OF THE TAF PERIOD AT 06Z TUESDAY.
SURFACE WINDS WILL BE CALM OR LIGHT NORTHERLY (5 KTS OR LESS) TO
START THE TAF PERIOD...THEN SWITCH TO SOUTHERLY MONDAY MORNING AND
PICK UP TO 5 TO 10 KTS DURING THE AFTERNOON. WINDS WILL REMAIN
SOUTHERLY MONDAY NIGHT...BUT DECREASE TO 5 KTS OR LESS.
.OUTLOOK...
LATE MON NGT-TUE NGT...MVFR/IFR RA LIKELY.
WED...MAINLY VFR...SCT SHRA.
WED NGT-FRI...VFR...NO WX.
&&
.FIRE WEATHER...
DAMP CONDITIONS WILL PREVAIL TODAY IN MOST SECTIONS WITH SCATTERED
TO NUMEROUS SHOWERS. AREAS ACROSS THE ADIRONDACKS...MOHAWK VALLEY
AND LITCHFIELD COUNTY WILL LIKELY SEE RAINFALL AMOUNTS UNDER A
QUARTER OF AN INCH TODAY...WHILE OTHER REGIONS WILL HAVE A QUARTER
TO UPWARDS OF NEARLY HALF AN INCH.
RH VALUES WILL REMAIN ELEVATED TODAY...GENERALLY NO LOWER THAN 60-75
PERCENT.
A SOAKING RAIN IS IN THE OFFING LATER TONIGHT THROUGH TUESDAY NIGHT
WITH RAINFALL AMOUNTS RANGING FROM AROUND THREE QUARTERS OF INCH
ACROSS THE ADIRONDACKS...TO 1-3 INCHES ACROSS THE REMAINDER OF THE
REGION.
SOME DRYING IS EXPECTED WEDNESDAY...HOWEVER ADDITIONAL SHOWERS ARE
POSSIBLE.
MUCH DRIER WEATHER LOOKS LIKELY THURSDAY INTO NEXT WEEKEND.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED THROUGH TODAY.
IT STILL LOOKS AS IF TODAY/S RAINFALL WILL GENERALLY RANGE FROM A
QUARTER TO HALF AN INCH...WITH LIGHTER AMOUNTS UNDER A QUARTER OF AN
INCH ACROSS THE ADIRONDACKS...MOHAWK VALLEY AND LITCHFIELD COUNTY.
THIS RAIN WILL PRODUCE MINOR RISES ON STREAMS AND RIVERS AT THE
MOST.
THEN...IT LOOKS OF AS IF A MORE STEADY AND POTENTIALLY HEAVIER RAIN
WILL ENSUE TONIGHT INTO EARLY TUESDAY NIGHT. RAINFALL AMOUNTS STILL
LOOK TO BE IN ONE TO THREE INCH RANGE...EXCEPT A LITTLE LESS ACROSS
PORTIONS OF OUR ADIRONDACKS.
ASSUMING THIS RAINFALL AMOUNT WORKS OUT...THE ADIRONDACKS SHOULD
ONLY SEE ONLY ADDITIONAL MINOR RISES ON STREAMS AND RIVERS. OTHER
REGIONS WILL SEE MORE SIGNIFICANT WITHIN BANK RISES ON RIVERS AND
STREAMS...WITH MANY OF THEM POSSIBLY REACHING ACTION STAGE.
AGAIN...ASSUMING WE HAVE A GOOD HANDLE OF THE QPF AMOUNTS...FLOODING
IS NOT LIKELY AND THEREFORE NO FLOOD WATCHES WERE ISSUED WITH THIS
RAINFALL EVENT AT THIS TIME. IT WOULD BE A GOOD IDEA TO CHECK BACK
ON THE HYDROLOGY STATUS DURING THE NEXT COUPLE OF DAYS.
NEVERTHELESS...PONDING OF WATER IS A GOOD BET...MAINLY IN AREAS OF
POOR DRAINAGE AS RAINFALL RATES COULD REACH UP TO A QUARTER OF AN
INCH AN HOUR AT TIMES LATE TONIGHT INTO EARLY TUESDAY NIGHT.
SOME ADDITIONAL RAINFALL IS POSSIBLE ON WEDNESDAY WITH ANOTHER
FASTER MOVING COLD FRONT...BUT AT THIS POINT RIVER BASIN QPF WITH
THIS SYSTEM LOOKS TO BE UNDER A QUARTER OF AN INCH.
DRIER WEATHER IS THEN FORECAST LATE IN THE WEEK AND WEEKEND WHICH
WOULD ALLOW RIVERS AND STREAMS TO RECEDE BACK TO MORE SEASONAL
LEVELS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...HWJIV
LONG TERM...HWJIV
AVIATION...GJM
FIRE WEATHER...HWJIV
HYDROLOGY...HWJIV
AREA FORECAST DISCUSSION
NWS MIAMI FL
924 AM EDT MON MAY 14 2012
.UPDATE...
THE MORNING SURFACE ANALYSIS SHOWED A RIDGE AXIS EXTENDING WEST
OVER CENTRAL FLORIDA WITH LIGHT SOUTHEAST LOW-LEVEL FLOW STREAMING
ACROSS SOUTH FLORIDA. A COLD FRONT WAS ANALYZED OVER THE GULF
EXTENDING SOUTH FROM THE FL PANHANDLE TO THE SOUTHWEST GULF OF
MEXICO. RECENTLY ANIMATED WATER VAPOR LOOP SHOWED A POSITIVELY-
TILTED UPPER TROUGH EXTENDING SOUTHWEST OVER THE PLAINS AND A
RIDGE AXIS EXTENDING NORTH OVER THE WESTERN ATLANTIC. THIS PLACES
SOUTH FLORIDA UNDER PRIMARILY MOIST SOUTHWEST MID TO UPPER FLOW. A
WEAK SHORTWAVE TROUGH EMBEDDED WITHIN THIS SOUTHWEST FLOW
APPROACHING FROM THE WEST COMBINED WITH SUFFICIENT DAYTIME HEATING
AND INSTABILITY WILL BE ENOUGH TO INITIATE AFTERNOON CONVECTION
ACROSS PORTIONS OF THE LOCAL AREA TODAY. THE LATEST HRRR AND WRF
SOLUTIONS ARE IN DECENT AGREEMENT AND GENERALLY INDICATE THE
AFTERNOON CONVECTION SETTING UP OVER THE INTERIOR LOCATIONS AND
FARTHER NORTH AROUND THE LAKE AND PALM BEACH COUNTY AREA THROUGH
THE EVENING HOURS BEFORE TRENDING DOWN TONIGHT. THIS LINES UP
WELL WITH THE LATEST FORECAST PACKAGE AND ONLY SLIGHT
MODIFICATIONS WERE NEEDED IN THE HAZARDOUS WEATHER OUTLOOK THIS
MORNING TO INCLUDE THE POTENTIAL FOR STRONG WIND GUSTS AND SMALL
HAIL WITH ANY STORMS THAT BECOME STRONG TODAY. OTHERWISE...THE
PREVIOUS FORECAST PACKAGE REMAINS ON TRACK AND NO OTHER UPDATES
WERE NECESSARY AT THIS TIME. 85/AG
&&
.PREV DISCUSSION... /ISSUED 724 AM EDT MON MAY 14 2012/
AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH AT LEAST 16Z WITH EXTENSIVE
CIRRUS FIELD ACROSS S FL. CONVECTION IS EXPECTED TO DEVELOP AFT 16Z
ACROSS THE INTERIOR AND STEERING FLOW WILL TAKE IT TO THE NNE SO
MOSTLY AFFECT THE KPBI TERMINAL. HOWEVER, CANNOT RULE OUT THE
POSSIBILITY OF DEVELOPMENT FARTHER TO THE SOUTH AS THE AFTERNOON
PROGRESSES BUT CONFIDENCE NOT HIGH TO PLACE IN THE TAFS. LIGHT SE
SFC WIND WILL CONTINUE THROUGH THE PERIOD ALLOWING FOR W CST SEA
BREEZE AFT 18Z.
PREV DISCUSSION... /ISSUED 315 AM EDT MON MAY 14 2012/
DISCUSSION...BROAD UPPER TROUGH OVER THE EASTERN 2/3RDS OF THE U.S.
DEEPENS AS A SHORT WAVE MOVES INTO THE TROUGH FROM THE SOUTHERN
ROCKIES. THE TROUGH MOVES SLOWLY EASTWARD AND BY THURSDAY MORNING
WILL BE ALIGNED WITH THE E U.S. COAST AND EXTEND SW ACROSS THE FLA
PANHANDLE INTO THE N GULF OF MEX. AS THE TROUGH MOVES E AND OFFSHORE
INTO THE ATLC...A CLOSED LOW WILL DEVELOP OFF OF THE SE U.S. COAST
LATE THURSDAY NIGHT AND PERSIST INTO NEXT WEEKEND. AT THE
SURFACE...A SURFACE LOW IN THE SOUTHERN APPALACHIANS ALONG THE
SURFACE TROUGH ASSOCIATED WITH THE UPPER TROUGH WILL GET TO THE E
U.S. COAST AND THE FLA PANHANDLE BY WEDNESDAY NIGHT AS THE SURFACE
LOW MOVES INTO THE MID ATLC STATES. THE TROUGH WILL MOVE SE AND
THROUGH S FLA THURSDAY AND WILL BE SE OF THE AREA FRIDAY AND
SATURDAY. FINALLY THE ECWMF AND GFS INTO SIMILAR AGREEMENT.
FOR THE SHORT TERM...TODAY THROUGH WEDNESDAY...AS THE UPPER TROUGH
DEEPENS...WINDS ALOFT BECOME SW PULLING SOME DEEPER MOISTURE OVER S
FLA. AT THE LOWER LEVELS WINDS WILL BE SE BUT LIGHT ALLOWING E/W
COAST SEA BREEZES. COMBINED WITH HEATING...AN INCREASE IN SHOWERS
/MAINLY AFTERNOON THUNDERSTORMS CAN BE EXPECTED. WITH THE STEERING
WINDS ALOFT SW...THE CONVECTIVE ACTIVITY WILL AFFECT THE INTERIOR
AND NE COASTAL AREAS THOUGH ALL ZONES WILL SEE SOME RAINFALL. THIS
PATTERN WILL PERSIST EACH DAY WITH NOCTURNAL ACTIVITY POSSIBLE...
MAINLY OFF OF THE E COAST IN THE EVENING AND THE W COAST OVER
-NIGHT.
EXTENDED FORECAST...THURSDAY THROUGH SUNDAY...LITTLE CHANGE
THURSDAY THOUGH STEERING WINDS BECOME A LITTLE MORE NW AFFECTING THE
E COAST UNIFORMLY WITH CONVECTION. WITH AN UPPER CLOSED LOW
DEVELOPING OFF OF THE SE U.S. COAST FRIDAY AND INTO SATURDAY...AND
WITH THE SURFACE TROUGH SE OF THE AREA...DRIER AIR WILL MOVE OVER S
FLA WITH POPS DROPPING DRASTICALLY. VERY LITTLE...IF AT ALL...
LOWERING OF MAX/MIN TEMPERATURES EXPECTED.
MARINE...
WINDS 10 KNOTS OR LESS TONIGHT THROUGH FRIDAY THOUGH SHIFTING FROM
SOUTHERLY TO NORTHERLY THURSDAY AS THE TROUGH MOVES THROUGH. SEAS 2
FEET OR LESS AS WELL.
FIRE WEATHER...
RELATIVE HUMIDITY VALUES REMAIN ABOVE 35 PERCENT CRITICAL VALUE
THROUGH MID WEEK. NO PROBLEMS EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 73 85 72 / 50 40 50 40
FORT LAUDERDALE 84 74 85 75 / 40 30 50 40
MIAMI 85 74 86 74 / 30 30 50 30
NAPLES 86 70 86 71 / 30 20 30 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...57/DG
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
946 AM CDT MON MAY 14 2012
.DISCUSSION...THE REMAINS OF AN MCS IS WEAKENING AS IT MOVES
SOUTHEAST ACROSS THE WESTERN CWA. MOST MODELS DID NOT EVEN PICK UP
ON THIS PRECIP...HOWEVER THE LATEST RUC13 HAS AND IT SHOWS THE
PRECIP DISSIPATING OVER THE NEXT COUPLE OF HOURS...MAINLY DUE TO A
SLIGHTLY SUBSIDENT/DRIER AIRMASS IN PLACE ACROSS THE E CWA. ONLY
CONCERN IS THAT THIS PRECIP IS HEADING TOWARD AN AREA OF LESS
CIN/HIGHER CAPE ACROSS THE E CWA. FOR NOW...WILL LEAVE POPS AS
IS FOR TODAY UNLESS THIS SYSTEM RE-INTENSIFIES. REST OF FCST LOOKS
ON TRACK. NO MAJOR CHANGES TO THE FCST AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 724 AM CDT MON MAY 14 2012/
DISCUSSION...INTRODUCED SLIGHT END POPS UNTIL 18Z ACROSS THE RIO
GRANDE PLAINS AS MCS CONTINUES TO MOVE SOUTHEAST THIS MORNING.
UPDATED PRODUCTS OUT.
PREV DISCUSSION... /ISSUED 659 AM CDT MON MAY 14 2012/
DISCUSSION...UPDATED FOR 12Z AVIATION
AVIATION...LINGERING CONVECTION OVER MAVERICK COUNTY SHOULD
CONTINUE TO MOVE EAST...BUT SHOULD NOT IMPACTING THE TERMINALS.
OTHERWISE...VFR CONDITIONS TO PERSIST THROUGH TODAY. UPPER LEVEL
DISTURBANCE AND CHANCES FOR CONVECTION WILL INCREASE TONIGHT FROM
THE NORTHWEST. INCLUDED VCTS REMARKS AT LRD IN ANTICIPATION OF MCS
DEVELOPING TONIGHT. DID NOT INCLUDE AT THE OTHER TERMINALS ATTM.
WINDS GENERALLY REMAIN LESS THAN 12 KNOTS AT ALI/CRP/VCT...BUT MAY
BECOME A LITTLE GUSTY IN THE AFTERNOON AT LRD.
PREV DISCUSSION... /ISSUED 409 AM CDT MON MAY 14 2012/
SHORT TERM (TODAY THROUGH TUESDAY)...LATEST RADAR TRENDS SHOW
WEAKENING MCS OVER THE BIG BEND OF TEXAS. ANTICIPATE THIS
CONVECTION WILL NOT MAKE IT INTO LA SALLE AND WEBB COUNTIES SO
WILL KEEP POPS SILENT FOR THE MORNING HOURS. UPPER LEVEL TROUGH
WILL DROP SOUTHEAST OUT OF NEW MEXICO TODAY AND TONIGHT. MOISTURE
FIELDS BEGIN TO INCREASE BY THIS EVENING. HIGH RESOLUTION MODELS
DEVELOP ANOTHER MCS OVER THE BIG BEND TONIGHT WITH IT TRACKING
FURTHER TO THE SOUTHEAST...APPROACHING THE NORTHWESTERN ZONES
BETWEEN 03Z AND 06Z TUESDAY. IF STORMS ARE ABLE TO MAINTAIN THEIR
STRENGTH...THEN PERHAPS A DAMAGING WIND GUST THREAT COULD
EMERGE...BUT CONFIDENCE OF THIS OCCURRING IS ON THE LOW SIDE. WENT
AHEAD AND INCREASED POPS ACROSS LA SALLE AND WEBB COUNTIES TO 60
PERCENT...TAPERING OFF TO 20 PERCENT OVER THE COASTAL WATERS FOR
THE TONIGHT PERIOD. HIGHER RAINFALL AMOUNTS SHOULD OCCUR NORTH OF
THE AREA. UPPER TROUGH WEAKEN A BIT AS IT CONTINUES TO MOVE TO THE
SOUTHEAST ON TUESDAY. NAM/GFS IN DECENT AGREEMENT ON PRECIP CHANCES
AND HAVE RAISED THEM A LITTLE. CLOUD COVER AND CHANCES FOR PRECIP
WILL KEEPS TEMPS DOWN ON TUESDAY... MAINLY IN THE LOWER 80S.
FAVORED THE COOLER METMOS TEMPS.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...ANY PRECIP THAT EXISTS
AT START OF LONG TERM PERIOD SHOULD END FROM NORTH TO SOUTH AS UPPER
LEVEL TROUGH AXIS SWINGS SOUTH OF CWA AND SURFACE HIGH PRESSURE
BUILDS INTO AREA. 00Z ECMWF IS ABOUT SIX HRS SLOWER THAN GFS WITH
MOVEMENT OF SYSTEM AND A LINGERING CHANCE OF PRECIP MAY BE NEEDED IN
LATER FORECAST PKGS IF SYSTEM SLOWS...BUT FOR NOW WILL LEAVE WED
DRY. QUIET WX THEN EXPECTED FOR SECOND HALF OF WORK WEEK AS WEAK
MID/UPPER LEVEL RIDGING DEVELOPS RESULTING IN WNW FLOW ALOFT AND
LIMITED DEEP LAYER MOISTURE. BY NEXT WEEKEND GFS AND ECMWF DIFFER
SOMEWHAT WITH MID/UPPER LEVEL PATTERN. GFS HAS MORE ZONAL FLOW WITH
ELONGATED MID LEVEL RIDGING WHILE ECMWF HAS MORE PRONOUNCED S/W
TROUGHS MOVING ACROSS THE PLAINS. BOTH GUIDANCE SUITES INITIATE
SURFACE CYCLOGENESIS ACROSS THE NORTHERN SOUTH HIGH PLAINS AND
DIURNAL SFC TROUGHING WHICH IN TURN SHOULD TIGHTEN THE PRESSURE
GRADIENT ACROSS S TX AND ALLOW LOW LEVEL MOISTURE ADVECTION TO
INCREASE. LOW LEVEL MOISTURE VALUES AND WIND PROFILE MAY BECOME MORE
CONDUCIVE FOR ISOLATED STREAMER SHOWERS ACROSS MARINE ZONES AND
COASTAL PLAINS BY LATE IN THE EXTENDED PERIOD. TEMPS ARE EXPECTED TO
BE AT OR SLIGHTLY ABOVE SEASONABLE VALUES /EXCEPT AROUND MID WEEK
WHERE BELOW NORMAL MIN TEMPS MAY OCCUR WHEN HIGH PRESSURE CENTER IS
THE CLOSEST/ AND HAVE GENERALLY GONE CLOSE TO A BIAS CORRECTED
MOSGUIDE/ECMWF BLEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 86 68 82 64 86 / 10 30 50 20 10
VICTORIA 86 64 80 60 86 / 10 30 50 20 10
LAREDO 92 69 86 67 91 / 20 50 50 20 10
ALICE 89 66 84 61 88 / 10 30 50 20 10
ROCKPORT 86 71 80 68 86 / 10 30 50 20 10
COTULLA 88 64 82 60 89 / 20 60 50 10 10
KINGSVILLE 88 68 84 62 87 / 10 30 50 30 10
NAVY CORPUS 84 71 82 68 84 / 10 30 50 30 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TE/81...SHORT TERM
GW/86...LONG TERM
AREA FORECAST DISCUSSION
NWS MIAMI FL
156 PM EDT MON MAY 14 2012
.AVIATION...VFR WILL PREVAIL. SHRA/TSRA WILL CONCENTRATE OVER THE
INTERIOR, BUT COULD MOVE TOWARDS KPBI LATER THIS AFTERNOON.
TRANQUIL WEATHER IS EXPECTED OVERNIGHT. TSRA IS A BETTER BET FOR
THE EAST COAST TERMINALS ON TUE AFTERNOON. ADDED VCTS THERE FOR
NOW, BUT TEMPO WILL LIKELY BE NEEDED AT LATER FORECAST ISSUANCES.
/GREGORIA
&&
.PREV DISCUSSION... /ISSUED 924 AM EDT MON MAY 14 2012/
UPDATE...
THE MORNING SURFACE ANALYSIS SHOWED A RIDGE AXIS EXTENDING WEST
OVER CENTRAL FLORIDA WITH LIGHT SOUTHEAST LOW-LEVEL FLOW STREAMING
ACROSS SOUTH FLORIDA. A COLD FRONT WAS ANALYZED OVER THE GULF
EXTENDING SOUTH FROM THE FL PANHANDLE TO THE SOUTHWEST GULF OF
MEXICO. RECENTLY ANIMATED WATER VAPOR LOOP SHOWED A POSITIVELY-
TILTED UPPER TROUGH EXTENDING SOUTHWEST OVER THE PLAINS AND A
RIDGE AXIS EXTENDING NORTH OVER THE WESTERN ATLANTIC. THIS PLACES
SOUTH FLORIDA UNDER PRIMARILY MOIST SOUTHWEST MID TO UPPER FLOW. A
WEAK SHORTWAVE TROUGH EMBEDDED WITHIN THIS SOUTHWEST FLOW
APPROACHING FROM THE WEST COMBINED WITH SUFFICIENT DAYTIME HEATING
AND INSTABILITY WILL BE ENOUGH TO INITIATE AFTERNOON CONVECTION
ACROSS PORTIONS OF THE LOCAL AREA TODAY. THE LATEST HRRR AND WRF
SOLUTIONS ARE IN DECENT AGREEMENT AND GENERALLY INDICATE THE
AFTERNOON CONVECTION SETTING UP OVER THE INTERIOR LOCATIONS AND
FARTHER NORTH AROUND THE LAKE AND PALM BEACH COUNTY AREA THROUGH
THE EVENING HOURS BEFORE TRENDING DOWN TONIGHT. THIS LINES UP
WELL WITH THE LATEST FORECAST PACKAGE AND ONLY SLIGHT
MODIFICATIONS WERE NEEDED IN THE HAZARDOUS WEATHER OUTLOOK THIS
MORNING TO INCLUDE THE POTENTIAL FOR STRONG WIND GUSTS AND SMALL
HAIL WITH ANY STORMS THAT BECOME STRONG TODAY. OTHERWISE...THE
PREVIOUS FORECAST PACKAGE REMAINS ON TRACK AND NO OTHER UPDATES
WERE NECESSARY AT THIS TIME. 85/AG
PREV DISCUSSION... /ISSUED 724 AM EDT MON MAY 14 2012/
AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH AT LEAST 16Z WITH EXTENSIVE
CIRRUS FIELD ACROSS S FL. CONVECTION IS EXPECTED TO DEVELOP AFT 16Z
ACROSS THE INTERIOR AND STEERING FLOW WILL TAKE IT TO THE NNE SO
MOSTLY AFFECT THE KPBI TERMINAL. HOWEVER, CANNOT RULE OUT THE
POSSIBILITY OF DEVELOPMENT FARTHER TO THE SOUTH AS THE AFTERNOON
PROGRESSES BUT CONFIDENCE NOT HIGH TO PLACE IN THE TAFS. LIGHT SE
SFC WIND WILL CONTINUE THROUGH THE PERIOD ALLOWING FOR W CST SEA
BREEZE AFT 18Z.
PREV DISCUSSION... /ISSUED 315 AM EDT MON MAY 14 2012/
DISCUSSION...BROAD UPPER TROUGH OVER THE EASTERN 2/3RDS OF THE U.S.
DEEPENS AS A SHORT WAVE MOVES INTO THE TROUGH FROM THE SOUTHERN
ROCKIES. THE TROUGH MOVES SLOWLY EASTWARD AND BY THURSDAY MORNING
WILL BE ALIGNED WITH THE E U.S. COAST AND EXTEND SW ACROSS THE FLA
PANHANDLE INTO THE N GULF OF MEX. AS THE TROUGH MOVES E AND OFFSHORE
INTO THE ATLC...A CLOSED LOW WILL DEVELOP OFF OF THE SE U.S. COAST
LATE THURSDAY NIGHT AND PERSIST INTO NEXT WEEKEND. AT THE
SURFACE...A SURFACE LOW IN THE SOUTHERN APPALACHIANS ALONG THE
SURFACE TROUGH ASSOCIATED WITH THE UPPER TROUGH WILL GET TO THE E
U.S. COAST AND THE FLA PANHANDLE BY WEDNESDAY NIGHT AS THE SURFACE
LOW MOVES INTO THE MID ATLC STATES. THE TROUGH WILL MOVE SE AND
THROUGH S FLA THURSDAY AND WILL BE SE OF THE AREA FRIDAY AND
SATURDAY. FINALLY THE ECWMF AND GFS INTO SIMILAR AGREEMENT.
FOR THE SHORT TERM...TODAY THROUGH WEDNESDAY...AS THE UPPER TROUGH
DEEPENS...WINDS ALOFT BECOME SW PULLING SOME DEEPER MOISTURE OVER S
FLA. AT THE LOWER LEVELS WINDS WILL BE SE BUT LIGHT ALLOWING E/W
COAST SEA BREEZES. COMBINED WITH HEATING...AN INCREASE IN SHOWERS
/MAINLY AFTERNOON THUNDERSTORMS CAN BE EXPECTED. WITH THE STEERING
WINDS ALOFT SW...THE CONVECTIVE ACTIVITY WILL AFFECT THE INTERIOR
AND NE COASTAL AREAS THOUGH ALL ZONES WILL SEE SOME RAINFALL. THIS
PATTERN WILL PERSIST EACH DAY WITH NOCTURNAL ACTIVITY POSSIBLE...
MAINLY OFF OF THE E COAST IN THE EVENING AND THE W COAST OVER
-NIGHT.
EXTENDED FORECAST...THURSDAY THROUGH SUNDAY...LITTLE CHANGE
THURSDAY THOUGH STEERING WINDS BECOME A LITTLE MORE NW AFFECTING THE
E COAST UNIFORMLY WITH CONVECTION. WITH AN UPPER CLOSED LOW
DEVELOPING OFF OF THE SE U.S. COAST FRIDAY AND INTO SATURDAY...AND
WITH THE SURFACE TROUGH SE OF THE AREA...DRIER AIR WILL MOVE OVER S
FLA WITH POPS DROPPING DRASTICALLY. VERY LITTLE...IF AT ALL...
LOWERING OF MAX/MIN TEMPERATURES EXPECTED.
MARINE...
WINDS 10 KNOTS OR LESS TONIGHT THROUGH FRIDAY THOUGH SHIFTING FROM
SOUTHERLY TO NORTHERLY THURSDAY AS THE TROUGH MOVES THROUGH. SEAS 2
FEET OR LESS AS WELL.
FIRE WEATHER...
RELATIVE HUMIDITY VALUES REMAIN ABOVE 35 PERCENT CRITICAL VALUE
THROUGH MID WEEK. NO PROBLEMS EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 74 84 72 / 50 40 60 40
FORT LAUDERDALE 84 75 85 74 / 40 30 60 40
MIAMI 85 73 86 72 / 30 30 60 30
NAPLES 86 72 85 72 / 30 20 30 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
454 PM EDT MON MAY 14 2012
.SYNOPSIS...
LOW PRESSURE AND AN ASSOCIATED COLD FRONT WILL SLOWLY MOVE EAST
ACROSS THE REGION THROUGH TONIGHT. HIGH MOISTURE WILL CONTINUE AHEAD
OF THIS SYSTEM. SOME DRYING IS EXPECTED TUESDAY WHICH WILL RESULT
IN SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS THROUGH MIDWEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
UPPER TROUGH STILL TO THE WEST PULLING MOISTURE ACROSS THE REGION
FROM THE SOUTH. BOTH OBSERVED AND FORECAST SOUNDINGS ARE NEARLY
MOIST ADIABATIC WHICH SHOULD ALLOW SHOWERS TO POP UP WITH THE
SLIGHTEST TRIGGER. RUC13 SHOWS WEAK TROUGH ACROSS THE REGION LATE
THIS AFTERNOON INTO THE EARLY EVENING HOURS. ALSO...STRONG
AFTERNOON SURFACE HEATING HAS ALLOW STRONG AND IN SOME CASES NEAR
SEVERE THUNDERSTORM ACTIVITY TO DEVELOP MAINLY IN THE SOUTHERN
PART OF THE FORECAST AREA. EXPECT RAINFALL AMOUNTS TO REMAIN ONE
QUARTER INCH OR LESS IN THE WESTERN MIDLANDS AND TAPER TO LESS
THAN A TENTH OF AN INCH OVER THE EASTERN MIDLANDS THROUGH THIS
AFTERNOON...MAINLY DUE TO A LACK OF FORCING.
TONIGHT...THE UPPER TROUGH WILL BE SLOW MOVING AS IT MOVES INTO
THE REGION AND WILL CONTINUE TO PROVIDE UPPER SUPPORT
OVERNIGHT...ESPECIALLY DURING THE EVENING HOURS...THEREFORE WILL
CONTINUE WITH LIKELY POPS OVERNIGHT. THE PRECIPITABLE WATER AXIS
SHIFTS OVER THE FORECAST AREA OVERNIGHT AND EXPECT THE BEST
RAINFALL ACCUMULATION TO OCCUR DURING THIS PERIOD. THE WESTERN AND
NORTHERN MIDLANDS WILL LIKELY SEE THE HIGHEST AMOUNTS...POSSIBLY
UP TO AN INCH...BUT THE ENTIRE FORECAST AREA SHOULD SEE MODERATE
MEASURABLE RAINFALL THROUGH EARLY MONDAY MORNING. TEMPERATURES
TONIGHT WILL BE LIMITED BY INCREASED DEWPOINTS AND CLOUDS AND
PRECIPITATION...GENERALLY IN THE MID 60S.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
SURFACE TROUGH WILL REMAIN ACROSS THE AREA THROUGH THE PERIOD AND
SHOULD PROVIDE FOCUS FOR SCATTERED SHOWERS AND THUNDERSTORMS.
AIR MASS APPEARS TO REMAIN MODERATELY MOIST AND INCREASINGLY UNSTABLE THROUGH
THE PERIOD. SOME DRYING SUGGESTED BY MODELS ESPECIALLY GFS...HOWEVER
EXPECT PRECIPITABLE WATER TO REMAIN RELATIVELY HIGH...NEAR 1.5
INCHES AT TIMES WITH PERSISTENT SOUTHWEST MOIST 850MB FLOW AHEAD
OF UPPER LEVEL TROUGH ACROSS THE MISSISSIPPI VALLEY AND MIDWEST.
SEVERAL SHORT WAVE TRIGGERS LIKELY TO ROTATE THROUGH THE
REGION...WHICH SHOULD AID THUNDERSTORM DEVELOPMENT...HOWEVER
TIMING OF WAVES DIFFICULT. FORECAST HIGH CHANCE POPS DURING THE
LATE AFTERNOON AND EVENING TUESDAY...POSSIBLY LATE INTO TUESDAY
NIGHT ASSOCIATED WITH POSSIBLE STRONGER SHORT WAVE. CHANCE
WEDNESDAY ESPECIALLY EAST MIDLANDS WHERE DEEPER MOISTURE IS
AND STRONGER UPPER LEVEL FORCING IS LOCATED. TEMPERATURES SHOULD BE
WARMER TUESDAY AND WEDNESDAY WITH SOME BREAKS IN THE OVERCAST MID
MORNING THROUGH EARLY AFTERNOON.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MEDIUM RANGE MODELS HAVE COME INTO REASONABLE AGREEMENT WITH
POTENTIAL COASTAL LOW OFF THE CAROLINA COAST DURING THE EXTENDED
FORECAST PERIODS. BOTH GFS/ECMWF PUSH THE TROUGH FAR ENOUGH OFF
THE COAST THAT CONFIDENCE HAS INCREASED THAT THE SYSTEM LIKELY
WILL NOT AFFECT THE FORECAST AREA VERY MUCH. HIGH PRESSURE BUILDS
DOWN THE EAST COAST THURSDAY AND FRIDAY AS AN UPPER RIDGE BUILDS
OVER THE LOWER MISSISSIPPI VALLEY NORTHWARD INTO THE OHIO VALLEY
FOR THE WEEKEND. THIS WILL YIELD DRY WEATHER OVER OUR AREA THROUGH
THE WEEKEND WITH NEAR NORMAL TEMPERATURES EXPECTED.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
UPPER TROUGH STILL TO THE WEST OF THE FORECAST AREA BRINGING
PLENTY OF MOISTURE ON LOW LEVEL SOUTH TO SOUTHWEST WIND FLOW.
WITH REAL GOOD SURFACE HEATING WHERE CLOUDS HAVE BROKEN UP...
THERE IS A POTENTIAL FOR THUNDERSTORMS TO DEVELOP BUT WILL NOT
MENTION IN TAF SITES UNLESS ACTIVITY IS MOVING RIGHT AT TAF SITE.
RUC13 H5 SHOWS WEAK TROUGHINESS DURING THIS PERIOD...SO DECIDED
TO MENTION SHOWERS IN THE VICINITY FOR THE MOST PART. WILL GO
MAINLY VFR BUT BRIEF IFR TO MVFR CONDITIONS ARE POSSIBLE IN
SHOWERS AND THUNDERSTORMS. CAE 88D SHOWS MORE CONVECTION FIRING UP
BETWEEN AGS AND OGB. EXPECT ACTIVITY TO WEAKEN AS SUN GOES DOWN
AND SURFACE HEATING ENDS. AFTER MIDNIGHT...MOIST SOUTHWEST WIND
FLOW WILL CONTINUE IN THE LOWER LEVELS AND IT SHOULD FAVOR MORE
IFR STRATUS CEILING THAN IFR FOG. WILL GO MAINLY MVFR VSBYS WITH
FOG MOST LOCATIONS TUESDAY NEAR DAYBREAK BUT WILL HAVE LOWER IFR
VSBYS AT AGS AND OGB. AFTER 14Z TUESDAY MORNING...CONDITIONS
SHOULD HAVE IMPROVED TO VFR AGAIN BUT WILL KEEP SHOWER IN THE
VICINITY REMARKS AS MOISTURE AND UPPER FEATURES STILL SIMILAR TO
THOSE TODAY.
EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR TO IFR CONDITIONS
POSSIBLE AGAIN WEDNESDAY MORNING AS LOW PRESSURE SYSTEM SLOWLY MOVES
EAST.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...07
SHORT TERM...
LONG TERM...
AVIATION...07
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
150 PM EDT MON MAY 14 2012
.SYNOPSIS...
LOW PRESSURE AND AN ASSOCIATED COLD FRONT WILL SLOWLY MOVE EAST
ACROSS THE REGION THROUGH TONIGHT. HIGH MOISTURE WILL CONTINUE AHEAD
OF THIS SYSTEM. SOME DRYING IS EXPECTED TUESDAY WHICH WILL RESULT
IN SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS THROUGH MIDWEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPPER TROUGH STILL TO THE WEST PULLING MOISTURE ACROSS THE REGION
FROM THE SOUTH. BOTH OBSERVED AND FORECAST SOUNDINGS ARE NEARLY
MOIST ADIABATIC WHICH SHOULD ALLOW SHOWERS TO POP UP WITH THE
SLIGHTEST TRIGGER. RUC13 SHOWS WEAK TROUGH ACROSS THE REGION LATE
THIS AFTERNOON INTO THE EARLY EVENING HOURS. WHILE MOST THE ACTIVITY
HAS MOVED EAST...SHOWERS CAN STILL DEVELOP. CANNOT RULE OUT A
THUNDERSTORM OR TWO BUT ABUNDANT MOISTURE IS EXPECTED TO LIMIT
STRONG CONVECTIVE ACTIVITY FROM DEVELOPING. EXPECT RAINFALL AMOUNTS
TO REMAIN ONE QUARTER INCH OR LESS IN THE WESTERN MIDLANDS AND TAPER
TO LESS THAN A TENTH OF AN INCH OVER THE EASTERN MIDLANDS THROUGH
THIS AFTERNOON...MAINLY DUE TO A LACK OF FORCING.
TONIGHT...THE UPPER TROUGH WILL BE SLOW MOVING AS IT MOVES INTO
THE REGION AND WILL CONTINUE TO PROVIDE UPPER SUPPORT
OVERNIGHT...ESPECIALLY DURING THE EVENING HOURS...THEREFORE WILL
CONTINUE WITH LIKELY POPS OVERNIGHT. THE PRECIPITABLE WATER AXIS
SHIFTS OVER THE FORECAST AREA OVERNIGHT AND EXPECT THE BEST
RAINFALL ACCUMULATION TO OCCUR DURING THIS PERIOD. THE WESTERN AND
NORTHERN MIDLANDS WILL LIKELY SEE THE HIGHEST AMOUNTS...POSSIBLY
UP TO AN INCH...BUT THE ENTIRE FORECAST AREA SHOULD SEE MODERATE
MEASURABLE RAINFALL THROUGH EARLY MONDAY MORNING. TEMPERATURES
TONIGHT WILL BE LIMITED BY INCREASED DEWPOINTS AND CLOUDS AND
PRECIPITATION...GENERALLY IN THE MID 60S.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
SURFACE TROUGH WILL REMAIN ACROSS THE AREA THROUGH THE PERIOD AND
SHOULD PROVIDE FOCUS FOR SCATTERED SHOWERS AND THUNDERSTORMS.
AIR MASS APPEARS TO REMAIN MODERATELY MOIST AND INCREASINGLY UNSTABLE THROUGH
THE PERIOD. SOME DRYING SUGGESTED BY MODELS ESPECIALLY GFS...HOWEVER
EXPECT PRECIPITABLE WATER TO REMAIN RELATIVELY HIGH...NEAR 1.5
INCHES AT TIMES WITH PERSISTENT SOUTHWEST MOIST 850MB FLOW AHEAD
OF UPPER LEVEL TROUGH ACROSS THE MISSISSIPPI VALLEY AND MIDWEST.
SEVERAL SHORT WAVE TRIGGERS LIKELY TO ROTATE THROUGH THE
REGION...WHICH SHOULD AID THUNDERSTORM DEVELOPMENT...HOWEVER
TIMING OF WAVES DIFFICULT. FORECAST HIGH CHANCE POPS DURING THE
LATE AFTERNOON AND EVENING TUESDAY...POSSIBLY LATE INTO TUESDAY
NIGHT ASSOCIATED WITH POSSIBLE STRONGER SHORT WAVE. CHANCE
WEDNESDAY ESPECIALLY EAST MIDLANDS WHERE DEEPER MOISTURE IS
AND STRONGER UPPER LEVEL FORCING IS LOCATED. TEMPERATURES SHOULD BE
WARMER TUESDAY AND WEDNESDAY WITH SOME BREAKS IN THE OVERCAST MID
MORNING THROUGH EARLY AFTERNOON.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MEDIUM RANGE MODELS HAVE COME INTO REASONABLE AGREEMENT WITH
POTENTIAL COASTAL LOW OFF THE CAROLINA COAST DURING THE EXTENDED
FORECAST PERIODS. BOTH GFS/ECMWF PUSH THE TROUGH FAR ENOUGH OFF
THE COAST THAT CONFIDENCE HAS INCREASED THAT THE SYSTEM LIKELY
WILL NOT AFFECT THE FORECAST AREA VERY MUCH. HIGH PRESSURE BUILDS
DOWN THE EAST COAST THURSDAY AND FRIDAY AS AN UPPER RIDGE BUILDS
OVER THE LOWER MISSISSIPPI VALLEY NORTHWARD INTO THE OHIO VALLEY
FOR THE WEEKEND. THIS WILL YIELD DRY WEATHER OVER OUR AREA THROUGH
THE WEEKEND WITH NEAR NORMAL TEMPERATURES EXPECTED.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
UPPER TROUGH STILL TO THE WEST OF THE FORECAST AREA BRINGING
PLENTY OF MOISTURE ON LOW LEVEL SOUTH TO SOUTHWEST WIND FLOW.
AIR MASS NEARLY SATURATED WITH BOTH LAPS AND MODEL SOUNDING MOIST
ADIABATIC. THIS SHOULD LIMIT THUNDERSTORM DEVELOPMENT BUT SHOWERS
ARE EXPECTED TO DEVELOP ANY TIME THIS AFTERNOON THROUGH THE EARLY
EVENING HOURS WITH JUST A MODEST TRIGGER. RUC13 H5 SHOWS WEAK
TROUGHINESS DURING THIS PERIOD...SO DECIDED TO MENTION SHOWERS IN
THE VICINITY FOR THE MOST PART. WILL GO MAINLY VFR BUT BRIEF IFR
TO MVFR CONDITIONS ARE POSSIBLE IN JUST ABOUT ANY SHOWER.
THUNDERSTORMS ARE ALSO POSSIBLE BUT NOT CONFIDENT ENOUGH TO PUT
IN THE TAF SITES. CAE 88D SHOWS STRONGEST CONVECTIVE ACTIVITY WITH
LIGHTNING WELL EAST OF TAF SITES WITH CONVECTIVE LINE WHICH MOVED
THROUGH EARLIER THIS MORNING. ALSO...AIRMASS APPEARS MORE UNSTABLE
TO THE EAST WITH LAPS CAPES OVER 3000 J/KG AND LAPS LIS -6/-7. MORE
MODEST DYNAMICS OVER TAF SITES WITH LAPS CAPES AROUND 2000 J/KG AND
LAPS LIS AROUND -5. TREND GOOD THROUGH ABOUT MIDNIGHT TONIGHT...04Z.
SHOWERS ARE EXPECTED TO TAPER OFF BEFORE THEN THOUGH AROUND 01-02Z.
AFTER MIDNIGHT...MOIST SOUTHWEST WIND FLOW WILL CONTINUE IN THE
LOWER LEVELS AND IT SHOULD FAVOR MORE IFR STRATUS CEILING THAN IFR
FOG. WILL GO MAINLY MVFR VSBYS WITH FOG MOST LOCATIONS TUESDAY NEAR
DAYBREAK BUT WILL HAVE LOWER IFR VSBYS AT AGS AND OGB. AFTER 14Z
TUESDAY MORNING...CONDITIONS SHOULD HAVE IMPROVED TO VFR AGAIN BUT
WILL KEEP SHOWER IN THE VICINITY REMARKS AS MOISTURE AND UPPER
FEATURES STILL SIMILAR TO THOSE TODAY.
EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR TO IFR CONDITIONS
POSSIBLE AGAIN WEDNESDAY MORNING AS LOW PRESSURE SYSTEM SLOWLY MOVES
EAST.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
636 PM EDT MON MAY 14 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE UP THE EAST COAST TONIGHT, AND SPREAD RAIN
INTO THE AREA THROUGH TUESDAY, BEFORE ENDING LATE TUESDAY AND
TUESDAY NIGHT. SKIES WILL CLEAR BRIEFLY LATE TUESDAY AND EARLY
WEDNESDAY AHEAD OF A COLD FRONT. THIS FRONT WILL MOVE THROUGH LATE
WEDNESDAY WITH SHOWERS. HIGH PRESSURE WILL BUILD IN BEHIND THE
FRONT AND BRING DRY WEATHER FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
625 PM UPDATE...
MINOR ADJUSTMENTS...MOSTLY FOR THE SPEED AND COVERAGE OF THE RAIN.
IN GENERAL FORECAST ON TRACK. RAINFALL AMOUNTS SO FAR UNDER AN
INCH.
PREVIOUS DISCUSSION...
MODELS STILL RESOLVING THE UPCOMING RAIN EVENT. OPERATIONAL NAM
HAS GONE BACK TO IT/S EARLIER SOLN AND BRINGS RAIN BACK TO THE
WEST WITHOUT GENERATING THE QPF BULLSEYE OVER THE ERN ZONES. SREF
MEAN SOLN IS MORE IN LINE WITH THE OPERATIONAL GFS WHICH HAS A
PCPN MAX OVER THE UPSLOPE AREAS IN THE CATSKILLS AND POCONOS.
HWVR...GFS MAX ACCUMULATED QPF OF OVER 4.5 INCHES SEEMS TOO
HIGH...AND MODEL MAY BE SUFFERING FROM CONV FEEDBACK WITH STRONG
STORMS FIRING OVER THE SE. SYSTEM HAS GOOD JET STRUCTURE WITH UPR
DIVERGENCE IN THE RR QUAD AND GOOD LL SLY INFLOW. PWATS APRCHS 2"
OVER THE EAST CST...A BIT LESS OVER THE FCST AREA.
CONSENSUS AVGD QPF PUTS 30 HR AMTS OVER THE WRN CATS APRCHG 2
INCHES...WELL BLO FFG AND HEADWATERS GUID. AREA HAS ACTUALLY BEEN A
BIT DRY AND HAS SOME OF THE HIGHEST GUID IN THEN FCST AREA.
SO...AFTER XTNSV COORD WITH SURROUNDING OFFICES HAVE DECIDED TO
HOLD OFF ON A WATCH ATTM. WILL KEEP HWO GOING WITH A MENTION OF
PTNL PRBLMS IF AMTS ARE HIGHER.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
OLD FNT IS SLOW TO MVE AS YET ANOTHER WV RIDES UP ON TUE...SLOWING
THE EWRD ADVANCE. LOOKS LIKE SOME HEAVIER RAIN COULD LINGER IN THE
EAST THRU ABT 18Z TUE AS THE WV PASSES. STILL...BNDRY REMAINS
NEARLY STATIONARY INTO EARLY WED BEFORE A STRONGER SHRT WV AND
SFC FNT APRCHS FROM THE WEST AND PUSHES IT ALONG.
WED/S FNT DOES NOT HAVE THE MOISTURE CONNECTION THAT TUE/S
DOES...SO DESPITE GOOD LL CONVERGENCE AND SUPPORT ALOFT...FNT MAY
NOT GENERATE ALL THAT MUCH PCPN. SOME MRGNL INSTABILITY DOES BRING
THE CHANCE OF CONV WITH THE FNT...ESP OVER THE NORTH NEAR THE
BETTER DYNAMICS AND SOME POOLED LL MOISTURE.
MUCH COOLER AND DRIER AIR FOLLOWS THE FNT ON THU AS A SFC HIPRES
BLDS INTO THE OH VLY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
IMPRVMNT WITH A WARMING TREND FOR THE MEDIUM RNG AS THE NE U.S.
TROF BEGINS TO PULL OUT AND UPR LVL/SFC RIDGING COMMENCES. BY
LATER IN THE WEEKEND THE PTRN DOES BCM MORE FVRBL FOR THE DVLPMNT
OF SOME ISOLD/WDLY SCT -TSRA MAINLY DUE TO DIURNAL EFFECTS...AND
THE PREV 00Z EURO SUGGESTED SOME POTNL FOR MCS ACTIVITY WITH
SYSTEMS DROPPING OUT OF CANADA OVER THE WEEKEND. GFS NOT SHOWING
THIS...AND INDEED HPC POPS INDICATE A DRY FCST UNTIL MONDAY OF NXT
WEEK. WE SEE NO REASON TO TO DISAGREE. WE DID GO MORE OPTIMISTIC
WITH THE SKY COVER THAN THE HPC FCST...WITH GNRLY PARTLY
SUNNY/PARTLY CLOUDY SKIES THRU THE PD.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
WDSPRD RESTRICTIONS ACRS THE FCST AREA THRU 18Z TUE DUE TO
CIGS/RAIN/BR. IT IS A TUFF CALL AT RME/SYR BUT XPCT POTNL FOR MVFR
THIS AFTN...SPCLY AT RME...THEN GNRL MVFR OVRNGT WITH THESE SITES
ON THE PERIPHERY OF THE STEADIER RAIN SHIELD. OTRW...IFR (PSBL
LIFR AT ITH/BGM/AVP) AND SOME MVFR IN RAIN AND MIST. HEAVIER RAINS ARE
XPCTD TO PULL OUT ON TUE MRNG...BUT LOW CIGS AND BR XPCTD TO
PERSIST THRU 18Z. WINDS THIS AFTN GNRLY S TO SE ARND 5 KTS...THEN
SELY 5-10 KTS TNGT INTO MON MRNG.
.OUTLOOK...
TUE NGT...LINGERING MVFR AT AVP...VFR ELSEWHERE WITH PONTL FOR VLY
FOG LATE AFFECTING ELM.
WED...MAINLY VFR...WDLY SCT AFTN -TSRA WITH MVFR PSBL.
THU/FRI/SAT...VFR...XCPT LATE NGT VLY FOG AFFECTING ELM.
&&
.HYDROLOGY...
IN GENERAL FLASH FLOOD AND HEADWATER GUID BLO FCSTD QPF FROM
NEARLY ALL SOURCES. OUTLIER IS THE GFS WICH DROPS A 30 HR TTL OF
ARND 4.5 INCHES OVER THE UPR DELAWARE BASIN. THAT AMT WLD CAUSE
FLOODING ISSUES BUT CONSENSUS IS THAT THE MODEL IS SUFFERING SOME
CONV FEEDBACK ISSUES. HWVR...PLACEMENT FROM THE GFS SEEMS CORRECT
SO BEST LOCATION FOR THE HIGHEST QPF APPEARS TO BE OVER ERN
DELAWARE AND NRN SULLIVAN...IN THE DELAWARE BASIN. HERE THE TOTAL QPF
IS 2 TO 2.5 INCHES WHICH COULD CAUSE MINOR FLOODING OF THE
FLASHIER CREEKS AND STREAMS SUCH AS THE WEST BRANCH AT WALTON. TO
THE WEST OVER THE UPR AND NORTH BRANCH SUSQ BASINS...AVERAGED
AMTS WILL BE LESS SO RVRS SHD STAY WELL BLO FLOOD STAGE. FOR THE
FINGER LAKES AND CHEMUNG BASINS AMOUNTS AN INCH OR LESS SO NO
PROBLEMS EXPECTED.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM/TAC
SHORT TERM...DGM
LONG TERM...
AVIATION...
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
326 PM EDT MON MAY 14 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE UP THE EAST COAST TONIGHT AND SPREAD RAIN
INTO THE AREA THROUGH TUESDAY. SKIES WILL CLEAR BRIEFLY LATE
TUESDAY AND EARLY WEDNESDAY AHEAD OF A COLD FRONT. THIS FRONT WILL
MOVE THROUGH LATE WEDNESDAY. HIGH PRESSURE WILL BUILD IN BEHIND
THE FRONT AND BRING DRY WEATHER FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
MODELS STILL RESOLVING THE UPCOMING RAIN EVENT. OPERATIONAL NAM
HAS GONE BACK TO IT/S EARLIER SOLN AND BRINGS RAIN BACK TO THE
WEST WITHOUT GENERATING THE QPF BULLSEYE OVER THE ERN ZONES. SREF
MEAN SOLN IS MORE IN LINE WITH THE OPERATIONAL GFS WHICH HAS A
PCPN MAX OVER THE UPSLOPE AREAS IN THE CATSKILLS AND POCONOS.
HWVR...GFS MAX ACCUMULATED QPF OF OVER 4.5 INCHES SEEMS TOO
HIGH...AND MODEL MAY BE SUFFERING FROM CONV FEEDBACK WITH STRONG
STORMS FIRING OVER THE SE. SYSTEM HAS GOOD JET STRUCTURE WITH UPR
DIVERGENCE IN THE RR QUAD AND GOOD LL SLY INFLOW. PWATS APRCHS 2"
OVER THE EAST CST...A BIT LESS OVER THE FCST AREA.
CONSENSUS AVGD QPF PUTS 30 HR AMTS OVER THE WRN CATS APRCHG 2
INCHES...WELL BLO FFG AND HEADWATERS GUID. AREA HAS ACTUALLY BEEN A
BIT DRY AND HAS SOME OF THE HIGHEST GUID IN THEN FCST AREA.
SO...AFTER XTNSV COORD WITH SURROUNDING OFFICES HAVE DECIDED TO
HOLD OFF ON A WATCH ATTM. WILL KEEP HWO GOING WITH A MENTION OF
PTNL PRBLMS IF AMTS ARE HIGHER.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
OLD FNT IS SLOW TO MVE AS YET ANOTHER WV RIDES UP ON TUE...SLOWING
THE EWRD ADVANCE. LOOKS LIKE SOME HEAVIER RAIN COULD LINGER IN THE
EAST THRU ABT 18Z TUE AS THE WV PASSES. STILL...BNDRY REMAINS
NEARLY STATIONARY INTO EARLY WED BEFORE A STRONGER SHRT WV AND
SFC FNT APRCHS FROM THE WEST AND PUSHES IT ALONG.
WED/S FNT DOES NOT HAVE THE MOISTURE CONNECTION THAT TUE/S
DOES...SO DESPITE GOOD LL CONVERGENCE AND SUPPORT ALOFT...FNT MAY
NOT GENERATE ALL THAT MUCH PCPN. SOME MRGNL INSTABILITY DOES BRING
THE CHANCE OF CONV WITH THE FNT...ESP OVER THE NORTH NEAR THE
BETTER DYNAMICS AND SOME POOLED LL MOISTURE.
MUCH COOLER AND DRIER AIR FOLLOWS THE FNT ON THU AS A SFC HIPRES
BLDS INTO THE OH VLY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
IMPRVMNT WITH A WARMING TREND FOR THE MEDIUM RNG AS THE NE U.S.
TROF BEGINS TO PULL OUT AND UPR LVL/SFC RIDGING COMMENCES. BY
LATER IN THE WEEKEND THE PTRN DOES BCM MORE FVRBL FOR THE DVLPMNT
OF SOME ISOLD/WDLY SCT -TSRA MAINLY DUE TO DIURNAL EFFECTS...AND
THE PREV 00Z EURO SUGGESTED SOME POTNL FOR MCS ACTIVITY WITH
SYSTEMS DROPPING OUT OF CANADA OVER THE WEEKEND. GFS NOT SHOWING
THIS...AND INDEED HPC POPS INDICATE A DRY FCST UNTIL MONDAY OF NXT
WEEK. WE SEE NO REASON TO TO DISAGREE. WE DID GO MORE OPTIMISTIC
WITH THE SKY COVER THAN THE HPC FCST...WITH GNRLY PARTLY
SUNNY/PARTLY CLOUDY SKIES THRU THE PD.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
WDSPRD RESTRICTIONS ACRS THE FCST AREA THRU 18Z TUE DUE TO
CIGS/RAIN/BR. IT IS A TUFF CALL AT RME/SYR BUT XPCT POTNL FOR MVFR
THIS AFTN...SPCLY AT RME...THEN GNRL MVFR OVRNGT WITH THESE SITES
ON THE PERIPHERY OF THE STEADIER RAIN SHIELD. OTRW...IFR (PSBL
LIFR AT ITH/BGM/AVP) AND SOME MVFR IN RAIN AND MIST. HEAVIER RAINS ARE
XPCTD TO PULL OUT ON TUE MRNG...BUT LOW CIGS AND BR XPCTD TO
PERSIST THRU 18Z. WINDS THIS AFTN GNRLY S TO SE ARND 5 KTS...THEN
SELY 5-10 KTS TNGT INTO MON MRNG.
.OUTLOOK...
TUE NGT...LINGERING MVFR AT AVP...VFR ELSEWHERE WITH PONTL FOR VLY
FOG LATE AFFECTING ELM.
WED...MAINLY VFR...WDLY SCT AFTN -TSRA WITH MVFR PSBL.
THU/FRI/SAT...VFR...XCPT LATE NGT VLY FOG AFFECTING ELM.
&&
.HYDROLOGY...
FFG AND HEADWATER GUID BLO FCSTD QPF FROM NEARLY ALL SOURCES.
OUTLIER IS THE GFS WICH DROPS A 30 HR TTL OF ARND 4.5 INCHES OVER
THE UPR DELAWARE BASIN. THAT AMT WLD CAUSE FLOODING ISSUES BUT
CONSENSUS IS THAT THE MODEL IS SUFFERING SOME CONV FEEDBACK
ISSUES. HWVR...PLACEMENT FROM THE GFS SEEMS CORRECT SO BEST
LOCATION FOR THE HIGHEST QPF APPEARS TO BE OVER ERN DELAWARE AND
NRN SULLIVAN...IN THE DELAWARE BASIN. TO THE WEST OVER THE UPR
SUSQ BASIN...AVERAGED AMTS WILL BE CONSIDERABLY LESS SO RVRS SHD
STAY WELL BLO FLOOD STAGE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM
SHORT TERM...DGM
LONG TERM...
AVIATION...
HYDROLOGY...DGM
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1229 PM CDT MON MAY 14 2012
.DISCUSSION...SEE AVIATION SECTION BELOW.
&&
.AVIATION...CLOUDS AROUND 15K FT ARE MOVG ACROSS S TX WITH A LOWER
DECK DVLPG AROUND 4K FT. EXPECTING VFR CONDITIONS THROUGH THE
REMAINDER OF THE DAY AND INTO THE EVENING HOURS. AN UPPER
DISTURBANCE WILL BRING SHRA`S/TSRA`S FROM THE BIG BEND AREA DOWN
INTO THE RIO GRANDE PLAINS TONIGHT AND ACROSS S TX OVERNIGHT AND
INTO TUE. MVFR/IFR CONDITIONS ARE EXPECTED IN AND AROUND THE
PRECIP LATE TONIGHT INTO TUE.
&&
.PREV DISCUSSION... /ISSUED 946 AM CDT MON MAY 14 2012/
DISCUSSION...THE REMAINS OF AN MCS IS WEAKENING AS IT MOVES
SOUTHEAST ACROSS THE WESTERN CWA. MOST MODELS DID NOT EVEN PICK UP
ON THIS PRECIP...HOWEVER THE LATEST RUC13 HAS AND IT SHOWS THE
PRECIP DISSIPATING OVER THE NEXT COUPLE OF HOURS...MAINLY DUE TO A
SLIGHTLY SUBSIDENT/DRIER AIRMASS IN PLACE ACROSS THE E CWA. ONLY
CONCERN IS THAT THIS PRECIP IS HEADING TOWARD AN AREA OF LESS
CIN/HIGHER CAPE ACROSS THE E CWA. FOR NOW...WILL LEAVE POPS AS
IS FOR TODAY UNLESS THIS SYSTEM RE-INTENSIFIES. REST OF FCST LOOKS
ON TRACK. NO MAJOR CHANGES TO THE FCST AT THIS TIME.
PREV DISCUSSION... /ISSUED 724 AM CDT MON MAY 14 2012/
DISCUSSION...INTRODUCED SLIGHT END POPS UNTIL 18Z ACROSS THE RIO
GRANDE PLAINS AS MCS CONTINUES TO MOVE SOUTHEAST THIS MORNING.
UPDATED PRODUCTS OUT.
PREV DISCUSSION... /ISSUED 659 AM CDT MON MAY 14 2012/
DISCUSSION...UPDATED FOR 12Z AVIATION
AVIATION...LINGERING CONVECTION OVER MAVERICK COUNTY SHOULD
CONTINUE TO MOVE EAST...BUT SHOULD NOT IMPACTING THE TERMINALS.
OTHERWISE...VFR CONDITIONS TO PERSIST THROUGH TODAY. UPPER LEVEL
DISTURBANCE AND CHANCES FOR CONVECTION WILL INCREASE TONIGHT FROM
THE NORTHWEST. INCLUDED VCTS REMARKS AT LRD IN ANTICIPATION OF MCS
DEVELOPING TONIGHT. DID NOT INCLUDE AT THE OTHER TERMINALS ATTM.
WINDS GENERALLY REMAIN LESS THAN 12 KNOTS AT ALI/CRP/VCT...BUT MAY
BECOME A LITTLE GUSTY IN THE AFTERNOON AT LRD.
PREV DISCUSSION... /ISSUED 409 AM CDT MON MAY 14 2012/
SHORT TERM (TODAY THROUGH TUESDAY)...LATEST RADAR TRENDS SHOW
WEAKENING MCS OVER THE BIG BEND OF TEXAS. ANTICIPATE THIS
CONVECTION WILL NOT MAKE IT INTO LA SALLE AND WEBB COUNTIES SO
WILL KEEP POPS SILENT FOR THE MORNING HOURS. UPPER LEVEL TROUGH
WILL DROP SOUTHEAST OUT OF NEW MEXICO TODAY AND TONIGHT. MOISTURE
FIELDS BEGIN TO INCREASE BY THIS EVENING. HIGH RESOLUTION MODELS
DEVELOP ANOTHER MCS OVER THE BIG BEND TONIGHT WITH IT TRACKING
FURTHER TO THE SOUTHEAST...APPROACHING THE NORTHWESTERN ZONES
BETWEEN 03Z AND 06Z TUESDAY. IF STORMS ARE ABLE TO MAINTAIN THEIR
STRENGTH...THEN PERHAPS A DAMAGING WIND GUST THREAT COULD
EMERGE...BUT CONFIDENCE OF THIS OCCURRING IS ON THE LOW SIDE. WENT
AHEAD AND INCREASED POPS ACROSS LA SALLE AND WEBB COUNTIES TO 60
PERCENT...TAPERING OFF TO 20 PERCENT OVER THE COASTAL WATERS FOR
THE TONIGHT PERIOD. HIGHER RAINFALL AMOUNTS SHOULD OCCUR NORTH OF
THE AREA. UPPER TROUGH WEAKEN A BIT AS IT CONTINUES TO MOVE TO THE
SOUTHEAST ON TUESDAY. NAM/GFS IN DECENT AGREEMENT ON PRECIP CHANCES
AND HAVE RAISED THEM A LITTLE. CLOUD COVER AND CHANCES FOR PRECIP
WILL KEEPS TEMPS DOWN ON TUESDAY... MAINLY IN THE LOWER 80S.
FAVORED THE COOLER METMOS TEMPS.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...ANY PRECIP THAT EXISTS
AT START OF LONG TERM PERIOD SHOULD END FROM NORTH TO SOUTH AS UPPER
LEVEL TROUGH AXIS SWINGS SOUTH OF CWA AND SURFACE HIGH PRESSURE
BUILDS INTO AREA. 00Z ECMWF IS ABOUT SIX HRS SLOWER THAN GFS WITH
MOVEMENT OF SYSTEM AND A LINGERING CHANCE OF PRECIP MAY BE NEEDED IN
LATER FORECAST PKGS IF SYSTEM SLOWS...BUT FOR NOW WILL LEAVE WED
DRY. QUIET WX THEN EXPECTED FOR SECOND HALF OF WORK WEEK AS WEAK
MID/UPPER LEVEL RIDGING DEVELOPS RESULTING IN WNW FLOW ALOFT AND
LIMITED DEEP LAYER MOISTURE. BY NEXT WEEKEND GFS AND ECMWF DIFFER
SOMEWHAT WITH MID/UPPER LEVEL PATTERN. GFS HAS MORE ZONAL FLOW WITH
ELONGATED MID LEVEL RIDGING WHILE ECMWF HAS MORE PRONOUNCED S/W
TROUGHS MOVING ACROSS THE PLAINS. BOTH GUIDANCE SUITES INITIATE
SURFACE CYCLOGENESIS ACROSS THE NORTHERN SOUTH HIGH PLAINS AND
DIURNAL SFC TROUGHING WHICH IN TURN SHOULD TIGHTEN THE PRESSURE
GRADIENT ACROSS S TX AND ALLOW LOW LEVEL MOISTURE ADVECTION TO
INCREASE. LOW LEVEL MOISTURE VALUES AND WIND PROFILE MAY BECOME MORE
CONDUCIVE FOR ISOLATED STREAMER SHOWERS ACROSS MARINE ZONES AND
COASTAL PLAINS BY LATE IN THE EXTENDED PERIOD. TEMPS ARE EXPECTED TO
BE AT OR SLIGHTLY ABOVE SEASONABLE VALUES /EXCEPT AROUND MID WEEK
WHERE BELOW NORMAL MIN TEMPS MAY OCCUR WHEN HIGH PRESSURE CENTER IS
THE CLOSEST/ AND HAVE GENERALLY GONE CLOSE TO A BIAS CORRECTED
MOSGUIDE/ECMWF BLEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 86 68 82 64 86 / 10 30 50 20 10
VICTORIA 86 64 80 60 86 / 10 30 50 20 10
LAREDO 92 69 86 67 91 / 20 50 50 20 10
ALICE 89 66 84 61 88 / 10 30 50 20 10
ROCKPORT 86 71 80 68 86 / 10 30 50 20 10
COTULLA 88 64 82 60 89 / 20 60 50 10 10
KINGSVILLE 88 68 84 62 87 / 10 30 50 30 10
NAVY CORPUS 84 71 82 68 84 / 10 30 50 30 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TE/81...SHORT TERM
GW/86...LONG TERM