Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 04/13/12
AREA FORECAST DISCUSSION
NWS DENVER CO
846 PM MDT THU APR 12 2012
.UPDATE...
&&
.SHORT TERM...SCATTERED SHOWERS CONTINUE TO LINGER ACROSS PORTIONS
OF THE CWA THIS EVENING AS WEAK FORCING ALOFT CONTINUES TO SLIDE
ACROSS NORTHERN PORTIONS OF COLORADO AS JET STREAK ALOFT SLIDES
OVER FAR NORTHERN NEW MEXICO. HAVE KEPT SHOWERS GOING LONGER
TONIGHT AND INCREASED POPS IN THE MOUNTAINS GIVEN THE AMOUNT OF
LINGERING ACTIVITY ACROSS WESTERN COLORADO.
.AVIATION...SURGE HAS BACKED INTO THE TERMINALS FROM THE EAST FROM
THIS AFTERNOON STORMS AND HAS SPARKED SOME WEAK CONVECTION AS
WINDS HAVE SHIFTED EAST TO NORTHEAST. HAVE ADDED VCSH OR TEMPO GROUPS FOR
THIS EVENING FOR THIS LINGERING ACTIVITY. GRADUAL ENDING OF
SHOWERS AFTER MIDNIGHT. STILL EXPECT A SHIFT TO DRAINAGE WINDS
LATER TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 537 PM MDT THU APR 12 2012/
UPDATE...WE HAVE CANCELLED THE TORNADO WATCH FOR ZONES 48>51.
ALTHOUGH SCT THUNDERSTORMS ARE STILL ONGOING...THE THREAT OF
TORNADIC/SEVERE THUNDERSTORMS HAS SHIFTED TO THE EAST OF THE CWFA.
PREV DISCUSSION... /ISSUED 332 PM MDT THU APR 12 2012/
SHORT TERM...SCATTERED STORMS CONTINUE ACROSS LOGAN...NORTHERN
WASHINGTON AND EASTERN MORGAN COUNTIES ON THE WESTERN EDGE OF THE
STABLE AIR WHERE LAPS SURFACE ANALYSIS SHOWING CAPES FROM
1000-1500 J/KG. FURTHER NORTHEAST...CAPES MINIMAL BUT ARE
INCREASING. STORMS ARE NOW FIRING ACROSS PHILLIPS COUNTY. STILL
DECENT SHEAR IN THIS REGION WITH LOW LEVEL SOUTHEASTERLIES AND
WESTERLY FLOW ALOFT. TORNADO WATCH CURRENTLY IN EFFECT FOR THAT
REGION THROUGH 02Z. POTENTIAL FOR THOSE STORMS TO PRODUCE
HAIL...WIND ALONG WITH A FEW TORNADOES. FURTHER WEST...WEAK
NORTHERLY SURGE HELPED TO AID IN QUITE A BIT OF VIRGA TYPE SHOWERS
ALONG FRONT RANGE DURING THE AFTERNOON. ALSO A FEW REPORTS OF RAIN
HITTING THE GROUND. SHOWERS CURRENTLY CONCENTRATED ACROSS NORTHERN
AND EASTERN WELD COUNTY. SCATTERED SHOWERS ALSO OCCURRING ACROSS
MOUNTAINS...WITH LATEST WEB CAMS INDICATION SOME SNOW AND RAIN
ACROSS THE HIGHER ELEVATIONS OF SUMMIT AND GRAND COUNTIES. FOR
TONIGHT...CONVECTION OVER NORTHEAST CORNER TO SLIDE INTO NEBRASKA
DURING THE EVENING AS BACK EDGE OF SHORTWAVE HEADS EAST AND DRIER
AIR FROM SOUTH MOVES ACROSS AREA. WILL KEEP A SLIGHT CHANCE OF
STORMS IN THAT AREA THROUGH THE EVENING. ELSEWHERE ACROSS
PLAINS...STILL SOME QUESTION IF SHOWER ACTIVITY WILL CONTINUE...AS
LATEST NAM AND GFS STILL GENERATE SOME LIGHT QPF FOR MUCH OF THE
AREA THROUGH THE EVENING. BUT LATEST RUC AND HRR SHOWS THE SHOWERS
CONFINED TO WELD AND MORGAN COUNTIES. WILL ADD A SLIGHT CHANCE TO
THE EARLY EVENING GRIDS FOR EASTERN WELD AND MORGAN COUNTIES.
ACROSS MOUNTAINS... SOUTHWEST FLOW ALOFT CONTINUES. CROSS SECTIONS
SHOW SOME DECREASE IN MOISTURE...STILL ENOUGH TO KEEP A CHANCE OF
SNOW GOING. ON FRIDAY...THE SOUTHWEST FLOW ALOFT WILL CONTINUE TO
INCREASE AHEAD OF THE APPROACHING TROUGH WITH MODELS SHOWING A JET
MAX MOVING ACROSS WESTER COLORADO. CROSS SECTIONS GRADUALLY
INCREASE THE MOUNTAIN MOISTURE DURING THE AFTERNOON WITH THE NAM
SHOWING SOME INCREASE IN MID LEVEL QG ASCENT. THE DEEPER MOISTURE
STILL APPEARS WEST OF THE CFWA. THE GFS STILL IS DRIER. SO...WILL
KEEP THE CHANCE POPS GOING FOR THE MOUNTAINS FOR NOW WITH SLIGHT
CHANCE POPS FOR NORTH AND MIDDLE PARKS. TEMPERATURE AND THICKNESS
PROGS SUGGEST A MIX OF RAIN AND SNOW FOR THE MOUNTAINS...WITH
MAINLY SNOW ACROSS THE RIDGES. AS FOR PLAINS...MODELS SHOW
SOUTHWEST WINDS INCREASING BY AFTERNOON...THOUGH HINTS AT A
SURFACE CYCLONE DEVELOPING NORTH OF DENVER. AIRMASS WILL BE
DRY...NO POPS EXPECTED. LATEST GUIDANCE SHOWS HIGHS ACROSS PLAINS
IN THE LOWER AND MID 60S...WHICH LOOKS REASONABLE BASED ON
THICKNESS PROGS. CURRENT TEMPERATURE GRIDS IN LINE WITH
GUIDANCE...SEEMS REASONABLE.
LONG TERM...MODELS CONTINUE TO CONVERGE UPON ONE SOLUTION FOR
THIS WEEKEND...ONE THAT CONTAINS A BETTER POTENTIAL FOR
SIGNIFICANT PRECIPITATION AND COLDER TEMPERATURES AREAWIDE.
NAM...GFS...EUROPEAN...CANADIAN GEM AND SREF HAVE ALL LATCHED ON
THE DEEPENING TROUGH PASSING OVER THE EASTERN GREAT BASIN AND THE
CLOSED MID/UPPER LEVEL CYCLONE NEARING THE 4-CORNERS FRIDAY NIGHT.
AHEAD OF THIS TROUGH...LOW...MID AND UPPER LEVEL FLOW SOUTH-
SOUTHWESTERLY FRIDAY NIGHT INTO SATURDAY MORNING WHICH SHOULD KEEP
TEMPERATURES ON THE SEASONABLY MILD SIDE. MODELS HINT AT A SHORT
WAVE DISTURBANCE EJECTING NORTHEAST OUT OF THE BASE OF THE MAIN
TROUGH AND OVER THE NORTHERN MTNS FRIDAY NIGHT. COULD SEE A ROUND
OF RAIN AND SNOW SHOWERS IN THE HIGH COUNTRY WITH THIS WEAK
PERTABATION IN THE FLOW...BUT NOT LOOKING FOR MUCH IN THE WAY OF
MEASURABLE PCPN YET. THE FOOTHILLS AND PLAINS SHOULD REMAIN DRY
OVERNIGHT WITH THE DRYING EFFECTS OF A WEST-SOUTHWESTERLY
DOWNSLOPE FLOW.
ON SATURDAY...THE LATEST MODEL RUN SHOWS THE 500MB LOW PASSING
OVER THE 4-CORNERS AREA DURING THE DAY...A TAD SLOWER THAN WAS
PROGGED BY THE LAST COUPLE MODEL RUNS. AS IT DOES Q-G OMEGA
FIELDS INDICATE A STEADY INCREASE IN LARGE SCALE ASCENT OVER
NORTHERN AND NORTHEAST COLORADO. MODELS ALSO SHOW A SFC COLD
FRONT DROPPING SOUTH OUT OF WYOMING INTERACTING WITH AN INCREASING
MOIST SOUTHERLY BOUNDARY LAYER FLOW ON THE PLAINS. NAM...GFS AND
ECMWF ALL INDICATE LIGHT QPF BREAKING OUT ALONG THE WYOMING BORDER
AROUND MIDDAY WITH BANDED LIFT ALOFT...AND OVER REMAINING PORTIONS
OF THE FRONT RANGE AND NORTHEAST PLAINS BY 00Z/SUNDAY...IF NOT
SOONER. TEMPERATURES...IE. WETBULB TEMPS...STILL LOOK TOO WARM FOR
SNOW AT LOWER ELEVATIONS. HOWEVER IT/S LIKELY WE/LL SEE
TEMPERATURES AND SNOW LEVELS STEADILY LOWERING THROUGH THE DAY IN
THE HIGH COUNTRY...WITH ANY SNOW ACCUMULATION ON THE LIGHT SIDE
AND CONFINED TO HIGHER RIDGES FROM SUMMIT COUNTY NORTHWARD.
IT/S SATURDAY NIGHT AND SUNDAY WHEN MODELS PAINT A VERY WET AND
EVEN SNOWY PICTURE FOR OUR PART OF THE STATE. SUBTLE DIFFERENCES
IN THE MODELS BEGIN TO APPEAR AT THIS POINT WHICH ONLY ADDS
UNCERTAINTY TO THE FORECAST BEYOND SATURDAY. AS IT STANDS NOW...A
CONSENSUS OF THE MODELS SHOW THE UPPER LOW TRACKING EAST ALONG
THE COLORADO-NEW MEXICO BORDER SATURDAY NIGHT...THEN NORTHEAST
OVER SOUTHEAST COLORADO AND WESTERN KANSAS ON SUNDAY. GREATEST
SYNOPTIC SCALE LIFT GENERATED IN THE NORTHWEST QUAD OF THIS
CYCLONE...WHICH MODELS SHOW PASSING OVER THE NORTH CENTRAL MTNS
AND NORTHERN FRONT RANGE AND FOOTHILLS...SATURDAY NIGHT...AND OVER
THE CENTRAL AND SOUTHERN FRONT RANGE AND FOOTHILLS AND NORTHEAST
PLAINS DURING THE DAY SUNDAY. MODELS CONTINUE TO GO HIGH WITH QPF
AND SNOW ACCUMULATIONS WITH THIS STORM SYSTEM...ALTHOUGH PERHAPS
NOT AS AMBITIOUS AS BEFORE. A MAJORITY OF THE MODELS SHOW
SOUTHWEST-TO-NORTHEAST ORIENTED BANDS OF 1 TO 2 INCH QPF ACROSS
THE AREA BY LATE SUNDAY AFTERNOON...AND 1 TO 2 AND A HALF FOOT
SNOW ACCUMS BY 00Z/MONDAY IN THE FRONT RANGE MTNS AND FOOTHILLS.
MODELS EVEN SHOW PRETTY RESPECTABLE SNOW TOTALS ON THE PLAINS...
WITH MOIST FLOW WRAPPING AROUND THE BACK SIDE OF THIS PASSING
TROUGH/UPPER LOW. HOWEVER ALL DEPENDS ON TEMPERATURES AS IS OFTEN
THE CASE THIS TIME OF YEAR. THE GFS...ECMWF AND CANADIAN GEM SHOW
WETBULB TEMPS COLD ENOUGH FOR ALL SNOW ON THE PLAINS SATURDAY
NIGHT AND MOST OF SUNDAY...BUT THE NAM KEEPS TEMPS A BIT TOO WARM
EXCEPT MAYBE FOR A RAIN/SNOW MIX. FOR NOW WILL GO WITH LIKELY
POPS IN THE MTNS AND VALLEYS BEGINNING SATURDAY...AND FOR THE
REMAINDER OF THE CWFA SATURDAY NIGHT AND SUNDAY.
SUNDAY NIGHT AND MONDAY...AT THIS TIME...MOST OF THE MODELS SHOW
THE UPPER LOW AND ITS PRECIPITATION MOVING OUT ON MONDAY.
ALTHOUGH THE GFS IS SLOW TO MOVE PRECIP OUT AS IT SHOWS A
DISTURBANCE IN NORTHWEST FLOW SWINGING ACROSS THE AREA DURING THE
DAY. FOR NOW...WILL HANG ONTO TO LOW POPS ON MONDAY WITH SLIGHT
WARMING.
TUESDAY AND BEYOND...GFS AND GEM INDICATE THE PASSAGE OF YET ANOTHER
WEAK MID-LEVEL DISTURBANCE EMBEDDED IN NORTHWEST FLOW ON TUESDAY.
WHEREAS THE NAM AND ECMWF SHOW A SHORTWAVE RIDGE BUILDING OVER THE
STATE. FOR NOW WILL KEEP A SLIGHT CHANCE OF LIGHT RAIN SHOWERS IN
THE FCST FOR TUESDAY. BEYOND THAT...WILL GO WITH DRY AND WARMER
CONDITIONS PRETTY MUCH EVERYWHERE.
AVIATION... STILL SOME SHOWERS HOLDING ON NORTH AND EAST OF THE
DENVER AREA...SHOULD CONTINUE TO HEAD EAST THROUGH THE EVENING.
WINDS FINALLY HOLDING FROM THE NORTHWEST WITH SOME GUSTS TO 20 KTS
AT DIA. NORTHWEST WINDS SHOULD CONTINUE INTO THE EVENING BEFORE
DECREASING AND SHIFTING TO THE SOUTHWEST. CEILINGS HAVE STAYED
ABOVE 7000 FEET AGL AND NOT EXPECTED TO CREATE ILS CONCERNS.
SOUTHWEST WINDS TO CONTINUE THROUGH FRIDAY...SHOULD INCREASE BY
19Z WITH SOME GUSTS TO 20 KTS POSSIBLE. VFR TO PREVAIL.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ENTREKIN
LONG TERM....BAKER
AVIATION...ENTREKIN
AREA FORECAST DISCUSSION...UPDATED
NWS PUEBLO CO
625 PM MDT THU APR 12 2012
.UPDATE...
UPDATED TO CANCEL THE TORNADO WATCH FOR KIOWA AND PROWERS COUNTIES
FOR THIS EVENING. SATELLITE IMAGERY AND MESOSCALE ANALYSIS
INDICATE THE DRYLINE HAS MIXED EAST INTO KANSAS WITH THE MAIN
THUNDERSTORM THREAT BEING TO OUR NORTH AND EAST. REMOVED
THUNDERSTORMS FROM BOTH COUNTIES FOR THIS EVENING. NO OTHER
CHANGES TO THE FORECAST AT THIS TIME. MOZLEY
&&
.PREV DISCUSSION... /ISSUED 322 PM MDT THU APR 12 2012/
SHORT TERM...
(TONIGHT AND FRIDAY)
..SEVERE STORMS POSSIBLE NEAR THE KANSAS BORDER THIS AFTERNOON...
DRYLINE AT THIS TIME APPEARS TO BE CENTERED PARALLEL AND NEAR
HIGHWAY 287/385 THROUGH ERN PORTIONS OF BACA...PROWERS...AND KIOWA
COUNTIES. DEWPOINTS OVR THE I-25 CORRIDOR HAVE MIXED OUT TO THE
LOWER TEENS. HRRR STILL SHOWING THE POTENTIAL FOR AN ISOLD STORM OR
TWO DEVELOPING ALONG THE DRYLINE IN THE NEXT HOUR OR TWO...THEN
MOVING FAIRLY QUICKLY INTO KS. ENVIRONMENT IS STILL FAVORABLE E OF
THE DRYLINE FOR THE DEVELOPMENT OF TORNADIC SUPERCELLS...THUS THE
CURRENT TOR WATCH IN EFFECT FOR THIS AREA. 4KM WRF DOES NOT DEVELOP
ANY STRONG CONVECTION IN OUR AREA. SHOULD SEE FAIRLY SHORTLY WHETHER
THE CU FIELD OVR THE FAR SERN PLAINS WILL PRODUCE ANY PERSISTENT
CONVECTION.
FARTHER W...LOW RH AND STRENGTHENING SW WINDS HAVE LED TO MARGINAL
CRITICAL FIRE WX CONDITIONS. WITH WINDS EXPECTED TO CONTINUE TO GUST
THROUGH EARLY EVE...AND MORE DRY AIR ON THE WAY...WILL LEAVE RED
FLAG INTACT FOR THE BALANCE OF THE WARNING. HAVE ALSO CONVERTED THE
FIRE WX WATCH TO A WARNING FOR TOMORROW AFTERNOON FOR THE SAN LUIS
VALLEY...WITH CONTINUED DRY CONDITIONS AND GUSTY SW WINDS. RH SHOULD
BE ABOVE CRITICAL CRITERIA TOMORROW OVR MOST OF THE REMAINDER OF THE
DISTRICT...WITH TEMPS ALOFT FALLING OFF A BIT MORE AND RESULTANT
HIGHER HUMIDITY. EXPECT TEMPS TO VARY FROM THE 50S OVR THE SAN LUIS
VALLEY...UPR ARKANSAS...AND EL PASO-TELLER...TO THE LOWER 70S OVR
THE SERN PLAINS. SHOULD BE A GENERALLY DRY DAY E OF THE DVD. ANOTHER
SHORTWAVE IN ADVANCE OF THE BIG PACIFIC TROUGH FOR THIS WEEKEND WILL
KICK OFF SOME LIGHT SHSN OVR THE DVD DURING THE AFTERNOON...AND COULD
SEE SOME LIGHT ACCUMS OVR THE DVD BY FRI EVE. MAIN SHOW WILL COME
THIS WEEKEND...HOWEVER. 44
LONG TERM...
(FRIDAY NIGHT THROUGH NEXT THURSDAY)
OVERALL...MODEL SOLUTIONS HAVE TRENDED EVER SO SLIGHTLY BACK TO
THE SOUTH REGARDING THE TRACK OF THE UPPER LEVEL LOW ACROSS THE
STATE THIS WEEKEND...WHICH WOULD INCREASE THE THREAT OF HEAVY
PRECIPITATION OVER EASTERN PORTIONS OF THE AREA...ESPECIALLY
SUNDAY. FOR THE MOUNTAINS ALONG THE CONTINENTAL DIVIDE...SMALL
DIFFERENCES IN THE LOW TRACK WON`T HAVE A BIG IMPACT ON SNOW
AMOUNTS...AS ALMOST ALL MEDIUM RANGE MODELS HAVE A PROLONGED
PERIOD OF HEAVY SNOW FROM SATURDAY INTO AT LEAST SUNDAY NIGHT.
HAVE HOISTED A WINTER STORM WATCH FOR ALL OF THE HIGHER TERRAIN
ALONG THE DIVIDE...WHERE SNOW AMOUNTS COULD APPROACH 2 FEET OR
MORE BY LATE SUNDAY NIGHT. FARTHER EAST...NO HIGHLIGHTS YET AS
HEAVY SNOW WOULD BE SATURDAY NIGHT/SUNDAY AND SMALL CHANGES TO THE
TRACK OF THE UPPER LOW WILL HAVE A BIG IMPACT ON PRECIP AMOUNTS.
TAKEN AT FACE VALUE...GFS/ECMWF SUGGEST WARNING CRITERIA SNOWFALL
POSSIBLE OVER PIKES PEAK AND THE HIGHER PORTIONS OF THE
SANGRES...WITH A PERIOD OF HEAVY...WET...WIND DRIVEN SNOW OVER THE
PALMER DIVIDE SUNDAY MORNING. STILL A GOOD DEAL OF
UNCERTAINTY...THOUGH ALL MODELS SUGGEST AT LEAST SOME -SHRA/-SHSN
A GOOD BET LATE SATURDAY NIGHT INTO SUNDAY...AS COLD FRONT RACES
SOUTH AND UPPER LEVEL MOVES OVERHEAD. WILL THUS INCREASE POPS OVER
MOST OF THE EASTERN HALF OF THE AREA...EMPHASIZING A LATE
SAT/EARLY SUN WINDOW. MODELS APPEAR TO HANG ON TO LIGHT PRECIP TOO
LONG SUNDAY NIGHT INTO MONDAY...AS LOW AND MID LEVEL FLOW WILL BE
MAINLY DOWNSLOPE...SO WILL ONLY RUN WITH LOW POPS OVER THE HIGHER
TERRAIN MON INTO MON EVENING. RETURN TO WARMER AND DRIER WEATHER
BEGINS TUE AS FLAT UPPER RIDGE BUILDS OVER THE WESTERN U.S.
AVIATION...VFR CONDITIONS ARE EXPECTED FOR NEXT 24 H FOR THE TAF
SITES. GUSTY SW WINDS WILL PERSIST THROUGH FRI...REACHING PEAK
SPEEDS IN MID-LATE AFTERNOON. PERSISTENT SHSN WILL INCREASE OVR
THE CONTDVD ESPECIALLY BY LATE FRI...IN ADVANCE OF A LARGE STORM
SYSTEM THAT COULD AFFECT THE TERMINALS IN ERN CO THIS WEEKEND.
44
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ220-222-224-
225.
WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY EVENING
FOR COZ058-060-066-068.
RED FLAG WARNING FROM NOON TO 8 PM MDT FRIDAY FOR COZ224.
&&
$$
88/34
AREA FORECAST DISCUSSION
NWS DENVER CO
537 PM MDT THU APR 12 2012
.UPDATE...WE HAVE CANCELLED THE TORNADO WATCH FOR ZONES 48>51.
ALTHOUGH SCT THUNDERSTORMS ARE STILL ONGOING...THE THREAT OF
TORNADIC/SEVERE THUNDERSTORMS HAS SHIFTED TO THE EAST OF THE CWFA.
&&
.PREV DISCUSSION... /ISSUED 332 PM MDT THU APR 12 2012/
SHORT TERM...SCATTERED STORMS CONTINUE ACROSS LOGAN...NORTHERN
WASHINGTON AND EASTERN MORGAN COUNTIES ON THE WESTERN EDGE OF THE
STABLE AIR WHERE LAPS SURFACE ANALYSIS SHOWING CAPES FROM
1000-1500 J/KG. FURTHER NORTHEAST...CAPES MINIMAL BUT ARE
INCREASING. STORMS ARE NOW FIRING ACROSS PHILLIPS COUNTY. STILL
DECENT SHEAR IN THIS REGION WITH LOW LEVEL SOUTHEASTERLIES AND
WESTERLY FLOW ALOFT. TORNADO WATCH CURRENTLY IN EFFECT FOR THAT
REGION THROUGH 02Z. POTENTIAL FOR THOSE STORMS TO PRODUCE
HAIL...WIND ALONG WITH A FEW TORNADOES. FURTHER WEST...WEAK
NORTHERLY SURGE HELPED TO AID IN QUITE A BIT OF VIRGA TYPE SHOWERS
ALONG FRONT RANGE DURING THE AFTERNOON. ALSO A FEW REPORTS OF RAIN
HITTING THE GROUND. SHOWERS CURRENTLY CONCENTRATED ACROSS NORTHERN
AND EASTERN WELD COUNTY. SCATTERED SHOWERS ALSO OCCURRING ACROSS
MOUNTAINS...WITH LATEST WEB CAMS INDICATION SOME SNOW AND RAIN
ACROSS THE HIGHER ELEVATIONS OF SUMMIT AND GRAND COUNTIES. FOR
TONIGHT...CONVECTION OVER NORTHEAST CORNER TO SLIDE INTO NEBRASKA
DURING THE EVENING AS BACK EDGE OF SHORTWAVE HEADS EAST AND DRIER
AIR FROM SOUTH MOVES ACROSS AREA. WILL KEEP A SLIGHT CHANCE OF
STORMS IN THAT AREA THROUGH THE EVENING. ELSEWHERE ACROSS
PLAINS...STILL SOME QUESTION IF SHOWER ACTIVITY WILL CONTINUE...AS
LATEST NAM AND GFS STILL GENERATE SOME LIGHT QPF FOR MUCH OF THE
AREA THROUGH THE EVENING. BUT LATEST RUC AND HRR SHOWS THE SHOWERS
CONFINED TO WELD AND MORGAN COUNTIES. WILL ADD A SLIGHT CHANCE TO
THE EARLY EVENING GRIDS FOR EASTERN WELD AND MORGAN COUNTIES.
ACROSS MOUNTAINS... SOUTHWEST FLOW ALOFT CONTINUES. CROSS SECTIONS
SHOW SOME DECREASE IN MOISTURE...STILL ENOUGH TO KEEP A CHANCE OF
SNOW GOING. ON FRIDAY...THE SOUTHWEST FLOW ALOFT WILL CONTINUE TO
INCREASE AHEAD OF THE APPROACHING TROUGH WITH MODELS SHOWING A JET
MAX MOVING ACROSS WESTER COLORADO. CROSS SECTIONS GRADUALLY
INCREASE THE MOUNTAIN MOISTURE DURING THE AFTERNOON WITH THE NAM
SHOWING SOME INCREASE IN MID LEVEL QG ASCENT. THE DEEPER MOISTURE
STILL APPEARS WEST OF THE CFWA. THE GFS STILL IS DRIER. SO...WILL
KEEP THE CHANCE POPS GOING FOR THE MOUNTAINS FOR NOW WITH SLIGHT
CHANCE POPS FOR NORTH AND MIDDLE PARKS. TEMPERATURE AND THICKNESS
PROGS SUGGEST A MIX OF RAIN AND SNOW FOR THE MOUNTAINS...WITH
MAINLY SNOW ACROSS THE RIDGES. AS FOR PLAINS...MODELS SHOW
SOUTHWEST WINDS INCREASING BY AFTERNOON...THOUGH HINTS AT A
SURFACE CYCLONE DEVELOPING NORTH OF DENVER. AIRMASS WILL BE
DRY...NO POPS EXPECTED. LATEST GUIDANCE SHOWS HIGHS ACROSS PLAINS
IN THE LOWER AND MID 60S...WHICH LOOKS REASONABLE BASED ON
THICKNESS PROGS. CURRENT TEMPERATURE GRIDS IN LINE WITH
GUIDANCE...SEEMS REASONABLE.
LONG TERM...MODELS CONTINUE TO CONVERGE UPON ONE SOLUTION FOR
THIS WEEKEND...ONE THAT CONTAINS A BETTER POTENTIAL FOR
SIGNIFICANT PRECIPITATION AND COLDER TEMPERATURES AREAWIDE.
NAM...GFS...EUROPEAN...CANADIAN GEM AND SREF HAVE ALL LATCHED ON
THE DEEPENING TROUGH PASSING OVER THE EASTERN GREAT BASIN AND THE
CLOSED MID/UPPER LEVEL CYCLONE NEARING THE 4-CORNERS FRIDAY NIGHT.
AHEAD OF THIS TROUGH...LOW...MID AND UPPER LEVEL FLOW SOUTH-
SOUTHWESTERLY FRIDAY NIGHT INTO SATURDAY MORNING WHICH SHOULD KEEP
TEMPERATURES ON THE SEASONABLY MILD SIDE. MODELS HINT AT A SHORT
WAVE DISTURBANCE EJECTING NORTHEAST OUT OF THE BASE OF THE MAIN
TROUGH AND OVER THE NORTHERN MTNS FRIDAY NIGHT. COULD SEE A ROUND
OF RAIN AND SNOW SHOWERS IN THE HIGH COUNTRY WITH THIS WEAK
PERTABATION IN THE FLOW...BUT NOT LOOKING FOR MUCH IN THE WAY OF
MEASURABLE PCPN YET. THE FOOTHILLS AND PLAINS SHOULD REMAIN DRY
OVERNIGHT WITH THE DRYING EFFECTS OF A WEST-SOUTHWESTERLY
DOWNSLOPE FLOW.
ON SATURDAY...THE LATEST MODEL RUN SHOWS THE 500MB LOW PASSING
OVER THE 4-CORNERS AREA DURING THE DAY...A TAD SLOWER THAN WAS
PROGGED BY THE LAST COUPLE MODEL RUNS. AS IT DOES Q-G OMEGA
FIELDS INDICATE A STEADY INCREASE IN LARGE SCALE ASCENT OVER
NORTHERN AND NORTHEAST COLORADO. MODELS ALSO SHOW A SFC COLD
FRONT DROPPING SOUTH OUT OF WYOMING INTERACTING WITH AN INCREASING
MOIST SOUTHERLY BOUNDARY LAYER FLOW ON THE PLAINS. NAM...GFS AND
ECMWF ALL INDICATE LIGHT QPF BREAKING OUT ALONG THE WYOMING BORDER
AROUND MIDDAY WITH BANDED LIFT ALOFT...AND OVER REMAINING PORTIONS
OF THE FRONT RANGE AND NORTHEAST PLAINS BY 00Z/SUNDAY...IF NOT
SOONER. TEMPERATURES...IE. WETBULB TEMPS...STILL LOOK TOO WARM FOR
SNOW AT LOWER ELEVATIONS. HOWEVER IT/S LIKELY WE/LL SEE
TEMPERATURES AND SNOW LEVELS STEADILY LOWERING THROUGH THE DAY IN
THE HIGH COUNTRY...WITH ANY SNOW ACCUMULATION ON THE LIGHT SIDE
AND CONFINED TO HIGHER RIDGES FROM SUMMIT COUNTY NORTHWARD.
IT/S SATURDAY NIGHT AND SUNDAY WHEN MODELS PAINT A VERY WET AND
EVEN SNOWY PICTURE FOR OUR PART OF THE STATE. SUBTLE DIFFERENCES
IN THE MODELS BEGIN TO APPEAR AT THIS POINT WHICH ONLY ADDS
UNCERTAINTY TO THE FORECAST BEYOND SATURDAY. AS IT STANDS NOW...A
CONSENSUS OF THE MODELS SHOW THE UPPER LOW TRACKING EAST ALONG
THE COLORADO-NEW MEXICO BORDER SATURDAY NIGHT...THEN NORTHEAST
OVER SOUTHEAST COLORADO AND WESTERN KANSAS ON SUNDAY. GREATEST
SYNOPTIC SCALE LIFT GENERATED IN THE NORTHWEST QUAD OF THIS
CYCLONE...WHICH MODELS SHOW PASSING OVER THE NORTH CENTRAL MTNS
AND NORTHERN FRONT RANGE AND FOOTHILLS...SATURDAY NIGHT...AND OVER
THE CENTRAL AND SOUTHERN FRONT RANGE AND FOOTHILLS AND NORTHEAST
PLAINS DURING THE DAY SUNDAY. MODELS CONTINUE TO GO HIGH WITH QPF
AND SNOW ACCUMULATIONS WITH THIS STORM SYSTEM...ALTHOUGH PERHAPS
NOT AS AMBITIOUS AS BEFORE. A MAJORITY OF THE MODELS SHOW
SOUTHWEST-TO-NORTHEAST ORIENTED BANDS OF 1 TO 2 INCH QPF ACROSS
THE AREA BY LATE SUNDAY AFTERNOON...AND 1 TO 2 AND A HALF FOOT
SNOW ACCUMS BY 00Z/MONDAY IN THE FRONT RANGE MTNS AND FOOTHILLS.
MODELS EVEN SHOW PRETTY RESPECTABLE SNOW TOTALS ON THE PLAINS...
WITH MOIST FLOW WRAPPING AROUND THE BACK SIDE OF THIS PASSING
TROUGH/UPPER LOW. HOWEVER ALL DEPENDS ON TEMPERATURES AS IS OFTEN
THE CASE THIS TIME OF YEAR. THE GFS...ECMWF AND CANADIAN GEM SHOW
WETBULB TEMPS COLD ENOUGH FOR ALL SNOW ON THE PLAINS SATURDAY
NIGHT AND MOST OF SUNDAY...BUT THE NAM KEEPS TEMPS A BIT TOO WARM
EXCEPT MAYBE FOR A RAIN/SNOW MIX. FOR NOW WILL GO WITH LIKELY
POPS IN THE MTNS AND VALLEYS BEGINNING SATURDAY...AND FOR THE
REMAINDER OF THE CWFA SATURDAY NIGHT AND SUNDAY.
SUNDAY NIGHT AND MONDAY...AT THIS TIME...MOST OF THE MODELS SHOW
THE UPPER LOW AND ITS PRECIPITATION MOVING OUT ON MONDAY.
ALTHOUGH THE GFS IS SLOW TO MOVE PRECIP OUT AS IT SHOWS A
DISTURBANCE IN NORTHWEST FLOW SWINGING ACROSS THE AREA DURING THE
DAY. FOR NOW...WILL HANG ONTO TO LOW POPS ON MONDAY WITH SLIGHT
WARMING.
TUESDAY AND BEYOND...GFS AND GEM INDICATE THE PASSAGE OF YET ANOTHER
WEAK MID-LEVEL DISTURBANCE EMBEDDED IN NORTHWEST FLOW ON TUESDAY.
WHEREAS THE NAM AND ECMWF SHOW A SHORTWAVE RIDGE BUILDING OVER THE
STATE. FOR NOW WILL KEEP A SLIGHT CHANCE OF LIGHT RAIN SHOWERS IN
THE FCST FOR TUESDAY. BEYOND THAT...WILL GO WITH DRY AND WARMER
CONDITIONS PRETTY MUCH EVERYWHERE.
&&
.AVIATION... STILL SOME SHOWERS HOLDING ON NORTH AND EAST OF THE
DENVER AREA...SHOULD CONTINUE TO HEAD EAST THROUGH THE EVENING.
WINDS FINALLY HOLDING FROM THE NORTHWEST WITH SOME GUSTS TO 20 KTS
AT DIA. NORTHWEST WINDS SHOULD CONTINUE INTO THE EVENING BEFORE
DECREASING AND SHIFTING TO THE SOUTHWEST. CEILINGS HAVE STAYED
ABOVE 7000 FEET AGL AND NOT EXPECTED TO CREATE ILS CONCERNS.
SOUTHWEST WINDS TO CONTINUE THROUGH FRIDAY...SHOULD INCREASE BY
19Z WITH SOME GUSTS TO 20 KTS POSSIBLE. VFR TO PREVAIL.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COOPER
LONG TERM....BAKER
AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS DENVER CO
355 PM MDT WED APR 11 2012
.SHORT TERM...WATER VAPOR LOOPS SHOW SHORTWAVE ROTATING ACROSS
CENTRAL AND SOUTHERN COLORADO. CONVECTION CONTINUES TO DEVELOP
ACROSS SUMMIT AND PARK COUNTIES ASSOCIATED WITH THIS WAVE...WITH
STORMS TRYING TO DEVELOP ACROSS THE FOOTHILLS. OVER THE PLAINS...
SURFACE ANALYSIS SHOWS CYCLONE HAD DEVELOPED ACROSS DENVER AREA
WITH LAPS ANALYSIS INDICATING CAPES OF 1000-1500 J/KG ALONG URBAN
CORRIDOR FROM SOUTHERN LARIMER COUNTY SOUTH INTO EASTERN DOUGLAS
AND NORTHWEST ELBERT COUNTIES. STILL QUITE A BIT OF CIN STILL
HOLDING ON ACROSS PLAINS...WITH ACARS SOUNDINGS SHOWING AIRMASS
STILL CAPPED. SHOULD SEE CONVECTION BEGIN TO SPREAD EAST INTO THE
URBAN CORRIDOR BY THE EVENING AS WAVE HEADS TOWARD THE NORTHEAST.
FEEL THAT ANY BOUNDARIES FROM MOUNTAINS AND FOOTHILLS SHOULD HELP
ERODE ANY LINGERING CAPS. MODELS WEAKEN THE CYCLONE BY 00Z AND
PUSH IT NORTHEAST INTO WELD COUNTY. THE LATEST HRRR RUN STILL
HOLDS ONTO SOME SORT OF A CONVERGENCE AREA FROM EAST OF DIA INTO
NORTHWEST ELBERT COUNTY INTO THE EARLY EVENING AND MAY STILL BE
THE FOCUS FOR THE STRONGER STORMS. THREATS TO BE HAIL ALONG WITH
GUSTY WINDS...ESPECIALLY WITH THE STRONGER STORMS. WILL STILL NEED
TO WATCH OUT FOR WEAK TORNADOES ALONG THE BOUNDARIES. WAVE TO MOVE
ACROSS THE AREA DURING THE EVENING...FEEL THE CURRENT POPS LOOK
REASONABLE. MODEL QPF GENERALLY LIGHT...THOUGH GFS LOOKS A BIT
ROBUST. ANOTHER NEXT WEAKER WAVE APPEARS TO BE MOVING ACROSS
UTAH...THOUGH CONVECTION NOT AS ABUNDANT. MODELS PICK UP ON THIS
SECOND WAVE AS WELL...BRINGING IT ACROSS THE AREA AROUND MIDNIGHT.
THERE IS SOME LIGHT MODEL QPF WITH THIS FEATURE ACROSS AREA...
MAINLY AFTER MIDNIGHT. ADDED SOME LOW POPS FOR FOOTHILLS AND
ADJACENT PLAINS FOR THIS WAVE...WITH LINGERING SHOWERS OVER THE
FAR NORTHEAST CORNER TOWARDS MORNING. STILL SOME MOISTURE ACROSS
MOUNTAINS TO KEEP THE SLIGHT CHANCE OF SNOW SHOWERS OVER ZONES 31
AND 33. AS FOR RED FLAG HILITES...WILL HOLD ON TO THE WARNINGS FOR
THE MOUNTAIN VALLEYS THROUGH 8PM THIS EVENING..THOUGH HUMIDITY
READINGS HAVE BEEN SLOWLY INCREASING ACROSS PARK COUNTY. ON
THURSDAY...SHORT WAVE RIDGE WILL BE OVER THE AREA DURING THE
MORNING WITH THE SOUTHWEST FLOW ALOFT INCREASING AGAIN BY
AFTERNOON ACROSS THE MOUNTAINS. MODELS SHOW SOME WEAK QG ASCENT
SLIDING ACROSS THE NORTHEAST CORNER DURING THE AFTERNOON. NAM AND
GFS GENERATE SOME LIGHT QPF ACROSS THE PLAINS. FOR NOW WILL KEEP
THE POPS AND WEATHER LIMITED TO THE NORTHEAST CORNER. FOR THE
MOUNTAINS...CROSS SECTIONS SHOW MOISTURE INCREASING AGAIN DURING
THE AFTERNOON. CURRENT CHANCE POPS STILL LOOK ON TRACK.
TEMPERATURES LOOK COOL ENOUGH DURING THE AFTERNOON FOR A MIX OF
RAIN AND SNOW.
.LONG TERM...SOME CONVERGENCE IN THE MODELS TODAY ON THIS WEEKENDS
STORM...THOUGH STILL SIGNIFICANT QUESTIONS ABOUT THE TRACK AND
INTENSITY. THE MOST IMPORTANT FACTOR NOW IS LOOKING LIKE THE
TEMPERATURES.
AHEAD OF THE STORM WE WILL HAVE DRY SSW FLOW OVER THE MOUNTAINS AND
PALMER DIVIDE ON FRIDAY AFTERNOON. COULD BE APPROACHING RED FLAG
CONDITIONS FOR A FEW HOURS ON FRIDAY AFTERNOON. FURTHER NORTH THE
WINDS WILL NOT BE AS STRONG AND THEY COULD TURN NORTHERLY AND BRING
IN COOLER AIR. WHILE LOW LEVELS WILL BE DRY...HIGH LEVEL MOISTURE
WILL BE INCREASING BRINGING MORE CLOUD COVER. JUST A SLIGHT CHANCE
OF SHOWERS INTO THE MOUNTAINS LATE...BUT I DID TRIM HIGHS BACK A
COUPLE OF DEGREES FOR THE CLOUD COVER.
FOR THE MAIN FEATURE...BETTER AGREEMENT NOW ON THE INTERACTION
BETWEEN TWO SHORTWAVES...WITH CONSENSUS SHOWING A SLOW MOVING LOW
WITH THE SHORTWAVES MAKING IT WOBBLE AS IT MOVES OVER THE ROCKIES.
GFS HAS BEEN MAINTAINING ITS INTENSITY BUT HAS THE SYSTEM MOVING
FASTER NOW...RESULTING IN ABOUT A 30 HOUR PERIOD OF GOOD UPSLOPE.
ECMWF IS NOT AS SPLIT BUT IS A BIT FASTER. GFS HAS THE LOW COMING
RIGHT OVER US...AND AS A RESULT PUTS DENVER ON THE SOUTH EDGE OF THE
HEAVY PRECIPITATION. MEANWHILE THE ECMWF HAS ITS LOW MORE
CONSOLIDATED THAN YESTERDAYS WITH A COMPROMISE POSITION ACROSS
SOUTHEASTERN COLORADO. THIS SOLUTION IS LOOKING MORE REASONABLE AND
WILL TREND THE FORECAST TOWARD IT. STILL A LONG PERIOD...MAYBE 24
HOURS...OF GOOD UPSLOPE WITH LOW STABILITY AND LOTS OF MOISTURE
AVAILABLE. THE ODDS OF A COUPLE FEET OF SNOW IN THE FOOTHILLS ARE
LOOKING BETTER. GFS CONTINUES TO PRODUCE 50 INCHES OF SNOW IN ITS
FAVORED UPSLOPE AREA...AND THE ECMWF NUMBERS ARE JUST A LITTLE LOWER
DUE TO THE FASTER MOVEMENT.
THE DETAILS WILL BE MORE IMPORTANT FOR THE PLAINS PRECIP...THOUGH A
PRETTY GOOD CHANCE OF GETTING A WETTING RAIN/SNOW EVENT ESPECIALLY
NORTH OF INTERSTATE 70. THE BIG QUESTION IS THE TEMPERATURE. MODEL
CONSENSUS HAS THE SNOW LEVEL RIGHT AROUND THE DENVER AREA...AT THIS
POINT WOULD FAVOR THE IDEA OF RAIN CHANGING TO SNOW SATURDAY NIGHT
AND STAYING SNOW ON SUNDAY BUT A COUPLE DEGREES EITHER WAY WOULD
MAKE A HUGE DIFFERENCE. WITH THE AMOUNT OF PRECIPITATION
POSSIBLE...THIS COULD STILL HAVE SOME IMPACT ESPECIALLY THE WEIGHT
OF THE WET SNOW ON VEGETATION. TRAVEL IMPACTS SHOULD BE QUITE
LIMITED WITH SOIL TEMPERATURES IN THE UPPER 40S AND AIR TEMPERATURES
THAT SHOULD REMAIN AROUND FREEZING. HIGH MODEL SNOW ACCUMULATIONS
EAST OF THE MOUNTAINS LOOK UNREALISTIC DUE TO THE METHODOLOGY
UNDERESTIMATING LOW LEVEL TEMPERATURES...BUT EVEN WITH SOME RAIN AND
LOW SNOW/LIQUID RATIOS THERE COULD BE SOME HEAVY WET SNOW.
FAIRLY QUIET FOR MONDAY THROUGH WEDNESDAY...PROBABLY STABLE AND DRY
ON THE PLAINS...HINTS OF A LITTLE MOISTURE IN WESTERLY FLOW FOR THE
MOUNTAINS SO I HELD ON TO LOW POPS THERE. I DID START TRIMMING
TEMPERATURES MAINLY ALONG THE FRONT RANGE FOR SOME EXPECTED SNOW
COVER IN THE EARLY PART OF THE WEEK...OTHERWISE IT WOULD BE A FAIRLY
PROMPT WARMUP.
&&
.AVIATION...CONVECTION FIRING ALONG FOOTHILLS AND PALMER
DIVIDE...WITH DENVER AREA STILL CAPPED. STILL SOME QUESTION ABOUT
STORMS AFFECTED THE AREA AIRPORTS...FEEL THE VCTS THE BEST WAY TO
GO FOR NOW. SLIGHT CHANCE FOR SHOWERS AFTER MIDNIGHT AS NEXT WAVE
MOVES THROUGH...THREAT APPEARS TOO LOW TO INCLUDE IN TAF. WILL
MAINTAIN VFR CONDITIONS...THOUGH CEILINGS OF 5000-6000 FEET
POSSIBLE THROUGH THE EVENING. GUSTY SOUTHEAST WINDS TO CONTINUE
FOR MUCH OF THE EVENING...THEN DECREASING AS SWITCHING TO THE
SOUTHWEST. WINDS TO TRANSITION TO THE NORTHWEST BY 18Z THURSDAY
WITH SPEEDS AROUND 12 KTS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ211-213-214.
&&
$$
SHORT TERM...D-L
LONG TERM....GIMMESTAD
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1050 AM MDT WED APR 11 2012
.UPDATE...STRATUS ACROSS AREA SLOW TO ERODE...ESPECIALLY ALONG
URBAN CORRIDOR...THOUGH SATELLITE INDICATE SOME EROSION ON THE
WEST EDGE OVER JEFFERSON COUNTY. STILL THINKING THAT IMPROVEMENT
SHOULD OCCUR BY THE AFTERNOON. STILL SOME MODEL DIFFERENCES ON
WHERE A CONVERGENCE ZONE MAY DEVELOP LATE AFTERNOON. LATEST HRRR
STILL MAINTAINING THE ZONE ACROSS DENVER...WHILE THE RUC AND NAM
DO NOT SHOW ANY CONVERGENCE ZONE WITH SOUTHEASTERLIES UP TO THE
FOOTHILLS. THIS WILL MAKE A DIFFERENCE IN THE STORM DEVELOPMENT
AND CONCENTRATION. FORECAST SOUNDINGS STILL SHOWING CAPES AROUND
1000 J/KG IF HIGHS CAN REACH THE MID 70S. WITH THE SLOW EROSION OF
THE STRATUS...IT MAY WELL BE LATE IN THE DAY BEFORE THE LOWER TO
MID 70S OCCUR. STILL NOT A CLEAR CUT SOLUTION...SO FOR NOW WILL
MAINTAIN THE CURRENT FORECAST WITH LATE AFTERNOON AND EVENING
CONVECTION MAINLY FOR THE FOOTHILLS AND ADJACENT PLAINS. IF THE
CONVERGENCE AREA DOES DEVELOP SOMEWHERE...THE POTENTIAL WILL EXIST
FOR SOME STORMS BECOMING SEVERE ALONG WITH A BRIEF TORNADO ALONG
THE CONVERGENCE ZONE. CANNOT TAKE OUT THE SEVERE THREAT JUST YET.
SO...FOR NOW JUST MINOR TWEAKS TO THE SKY AND WEATHER GRIDS.
RED FLAG WARNING STILL LOOKING ON TRACK FOR MOUNTAIN VALLEYS...
THOUGH HUMIDITY READINGS MAY BE A BIT HIGH ACROSS PARK COUNTY.
&&
.AVIATION...STRATUS SLOW TO ERODE ACROSS AREA AIRPORTS...THOUGH
APA FINALLY BROKE OUT OF THE LOWER STUFF. DELAYED THE DISSIPATION
OF THE LOWER STRATUS AT DEN AND BJC...LOOKS ON TRACK FOR NOW.
STILL THINKING THAT THE STRATUS SHOULD BE GONE BY 18Z AND WILL
CONTINUE THAT TREND FOR THE UPCOMING ISSUANCE. STILL SOME
UNCERTAINTIES ON DEVELOPMENT OF LOW LEVEL FEATURES...WHICH WILL
AFFECT STORM DEVELOPMENT. WITH THE UNCERTAINTY...NOT SURE A TEMPO
THUNDER GROUP IS WARRANTED. WILL MAINTAIN THE VCTS AND CONTINUE TO
MONITOR. SO WILL CONTINUE THE CURRENT TAF TRENDS.
&&
.PREV DISCUSSION... /ISSUED 418 AM MDT WED APR 11 2012/
SHORT TERM...SWLY FLOW ALOFT WILL INCREASE THRU THIS AFTN AS AN
UPPER LEVEL DISTURBANCE APPROACHES THE AREA. MEANWHILE A RATHER
STG SFC GRADIENT WILL EXIST AS LOW PRESSURE RESIDES IN THE MTNS
WITH A SFC HIGH OVER THE CENTRAL US. THIS RESULTS IN RATHER STG
SELY LOW LVL FLOW EAST OF THE MTNS. MEANWHILE NONE OF THE SHORT
RANGE MODELS AGREE ON WHERE A CONVERGENCE ZONE MAY DVLP BY MID TO
LATE AFTN. THE HI RES WRF HAS A CONVERGENCE ZONE JUST EAST OF
DENVER WHILE THE HRRR HAS IT RIGHT OVER DENVER WHILE THE NAM HAS
NO BNDRY AT ALL WITH ESE WINDS FLOWING INTO THE FOOTHILLS. CAPES
BY LATE AFTN ARE FCST BE AROUND 1000 J/KG WITH NO CAP IF HIGHS
RISE INTO THE MID 70S SO SHOULD SEE AT LEAST SOME WIDELY SCT TSTMS
DVLP IN IN AND NR THE FOOTHILLS AND IN THE MTNS. OVER THE PLAINS
THE AIRMASS WILL BE MUCH MORE STABLE SO ANY CONVECTION THRU THE
EARLY EVENING HOURS SHOULD STAY WEST OF A FORT MORGAN TO LIMON
LINE. SHEAR PROFILE WILL BECOME MORE FAVORABLE BY LATE AFTN INTO
THE EARLY EVENING HOURS SO COULD SEE A FEW SVR STORMS WITH
MARGINAL LARGE HAIL FROM DENVER SOUTH TO THE PALMER DIVIDE. IF
THERE IS A CONVERGENCE ZONE LIKE THE HRRR AND HI RES WRF SHOW LOW
LVL FLOW WILL BE ENHANCED ALONG THE BNDRY INCREASING HELICITY
VALUES SO NOT TOTALLY IMPOSSIBLE A BRIEF TORNADO COULD OCCUR. AS
FAR AS HIGHS YESTERDAY READINGS WERE AROUND 5 DEGREES WARMER THAN
EXPECTED. FOR THIS AFTN HIGHS WILL BE TRICKY DUE TO LINGERING
STATUS OVER THE PLAINS AND POSSIBLE CONVERGENCE ZONE NR DENVER.
HIGHS MADE NOT GET ABOVE ZONE OVER THE FAR NERN CORNER WHILE
READINGS CLOSER TO DENVER RISE INTO THE MID TO UPPER 70S OVER THE
ERN AD SRN SUBURBS WHILE READINGS OVER THE NRN AND WRN AREAS ONLY
REACH THE UPPER 60S TO LOWER 70S. WILL KEEP RED FLAG WARNING FOR
PARK COUNTY AND THE HIGHER VALLEYS DUE TO GUSTY WINDS...LOW
HUMIDITY AND POSSIBLE DRY LIGHTNING.
FOR TONIGHT THE UPPER LEVEL DISTURBANCE WILL MOVE QUICKLY ACROSS
WRN CO. CROSS-SECTIONS SHOW ENOUGH MOISTURE WITH THIS FEATURE
COULD BRING A CHC OF SNOW SHOWERS TO ZONES 31 AND 33 AFTER
MIDNIGHT. OTHERWISE OVER NERN CO WILL SEE SOME LINGERING TSTMS IN
THE EARLY EVEING HOURS ALONG THE FRONT RANGE HOWEVER FURTHER EAST
AIRMASS WILL REMAIN FAIRLY STABLE SO WILL ONLY MENTION A CHC OF
SHOWERS WITH ISOLD TSTMS.
LONG TERM...THIS WEEKEND APPEARS TO HAVE THE POTENTIAL TO BE
RATHER UNSETTLED AS A BROAD UPPER TROUGH SETTLES OVER THE WESTERN
U.S. AND THEN CUTS OFF SOMEWHERE IN THE VICINITY OF THE FOUR
CORNERS LATE IN THE WEEKEND. THE GFS HAS BEEN HINTING THAT THIS
SYSTEM COULD CONTAIN QUITE A BIT OF PRECIPITATION WHEN LOOKING AT
THE MODEL QPG FIELDS...INITIALLY OVER NORTHERN CALIFORNIA AND THE
SIERRA NEVADA...BUT THEN OVER COLORADO BY ABOUT SUNDAY. OTHER
MODELS HAVE NOT PRODUCED QUITE AS MUCH PRECIPITATION AS THE GFS...
BUT HAVE BEEN SUPPORTING THE IDEA THAT AN UPPER LEVEL SYSTEM WILL
AFFECT COLORADO WEATHER THROUGH THE WEEKEND. EVEN THE LATEST NAM
IS NOW SHOWING THE EASTERN PARTS OF THIS WEATHER SYSTEM BEING OVER
COLORADO SATURDAY AFTERNOON. THE Q-G DIAGNOSTICS PACKAGE FROM THE
GFS SHOWS A 30-36 HOUR PERIOD WITH STRONG LIFT OVER NORTHERN
COLORADO AS THE UPPER LOW PASSES OVER THE FOUR CORNERS. ALL THIS
BEING SAID...THERE IS STILL PLENTY OF UNCERTAINTY WHETHER THE
SYSTEM WILL EVOLVE LIKE THE GFS DEPICTS...BUT MOST OF THE GFS
ENSEMBLE MEMBERS SUPPORT THE OPERATIONAL SOLUTION. THE MAIN PERIOD
OF PRECIPITATION LOOKS LIKE IT WILL BE SATURDAY NIGHT AND SUNDAY.
THE OTHER UNCERTAINTY IS HOW WARM OR COLD THE SYSTEM WILL BE.
LOCATIONS ON THE PLAINS MAY REMAIN IN THE MID TO UPPER 30S ON
SUNDAY MORNING...LEADING TO RAIN OR A MIX OF RAIN AND SNOW WITH
SNOW LEVELS AROUND 6000 FEET OR HIGHER. THE MOISTURE IS CERTAINLY
GOING TO BE WELCOME...BUT WE WILL HAVE TO WATCH FOR HOW MUCH OF
FALLS IN THE FORM OF FROZEN PRECIPITATION. WITH THE EVENT STILL
OUT AT DAYS 4 AND 5...POPS ARE STILL IN THE CHANCE AND SLIGHT
CHANCE CATEGORY. THE FORECAST FOR THE EARLY PART OF NEXT WEEK IS
GOING TO DEPEND ON WHEN THE UPPER LOW MOVES OUT ONTO THE
PLAINS...ALLOWING UPPER LEVEL RIDGING TO RE-BUILD OVER THE STATE.
FOR NOW A SLIGHT CHANCE OF PRECIPITATION IS EXPECTED TO CONTINUE
THROUGH TUESDAY MORNING.
AVIATION...
A WELL DEFINED DENVER CYCLONE WAS NR DIA EARLY THIS MORNING WITH
ABUNDANT STRATUS OVER THE PLAINS WHICH WAS WRAPPING AROUND THE
BACK SIDE OF THE LOW AND SHOULD AFFECT BOTH BJC AND DIA THROUGH
THE MID MORNING HOURS WITH LIFR CONDITIONS. COULD SEE SOME LOCALLY DENSE
FOG AROUND DIA WHICH ALWAYS SEEMS TO HAPPEN IN THIS TYPE OF
SCENARIO MORE TIMES THAN NOT. WILL GRADUALLY BREAK UP LOW CLOUDS
BY 16Z. FOR THIS AFTN AM NOT REAL CONFIDENT IN HOW SFC FEATURES
WILL DEVELOP AS SHORT RANGE MODELS ARE NOT IN GOOD AGREEMENT WITH
PLACEMENT OF POSSIBLE CONVERGENCE ZONE BY MID TO LATE AFTN. IF
BNDRY ENDS UP WEST OF DIA THEN GUSTY SELY WINDS OF 20-30 MPH MAY
DVLP BY 21Z HOWEVER IF IT ENDS UP JUST TO THE EAST THEN WINDS
COULD BE MORE NE AND NOT AS STG. FOR NOW WILL GO WITH THE BNDRY
BEING WEST OF THE AIRPORT. AFTER 22Z THRU 02Z WIDELY SCT TSTMS
COULD AFFECT THE AIRPORT. THERE IS ENOUGH SHEAR AND INSTABILITY
FOR A SVR STORM THAT COULD PRODUCE BRIEF HAIL TO ONE INCH IN
DIAMETER AND GUSTY WINDS TO 50 MPH ALTHOUGH CHANCES ARE PROBABLY
AROUND 10%.
FOR TONIGHT WINDS SHOULD BE MORE SLY AND COULD REMAIN RATHER
GUSTY THROUGH MIDNIGHT WITH SPEEDS IN THE 20-30 MPH RANGE. AFTER
MIDNIGHT WINDS SHOULD BECOME MORE SSW WITH LIGHER SPEEDS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...RED FLAG WARNING FROM
NOON UNTIL 8PM MDT FOR COZ211..213 AND 214.
&&
$$
SHORT TERM...D-L
LONG TERM....DANKERS
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
829 AM MDT WED APR 11 2012
.UPDATE...
ISSUED AT 828 AM MDT WED APR 11 2012
WENT AHEAD AND ADDED THE UINTAH BASIN AND THE MIDDLE COLORADO
RIVER BASIN THE THE WIND ADVISORY. GUIDANCE NUMBERS FOR THOSE
AREAS LOOK AS STRONG AS OTHER COVERED ZONES AND TYPICALLY THESE
ZONES REACH CRITERIA IN THIS TYPE OF WIND EVENT. I ALSO EXTENDED
THE TIMING OF THE ADVISORY UNTIL MIDNIGHT. THE STRONGEST WINDS
SEEM TO BE BETWEEN 00Z AND 03Z...WITH GUSTY CONDITIONS STILL
EXPECTED THROUGH THE LATE EVENING.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 447 AM MDT WED APR 11 2012
SURFACE GRADIENT WINDS INCREASE TODAY AS A SUB 1000 MB SURFACE LOW
TRACKS ACROSS NE UTAH AND EXTREME NW COLORADO LATE IN THE DAY.
SHORT WAVE DISTURBANCE MOVING INTO SRN CALIFORNIA THIS MORNING
PIVOTS NORTHEAST...THIS ALLOWS UPPER LEVEL DIVERGENCE TO INCREASES
THE NEGATIVE TILT SHORT WAVE APPROACHES ERN UTAH THIS AFTERNOON. SUSTAINED
700 MB WINDS/TEMPS AT 35 KNOTS/AROUND +7C AND WILL TRANSLATE TO
THE SURFACE AS STRONG GUSTY WINDS WITH NEAR RECORD WARMTH. THE
FORECAST GRIDS REFLECT THIS TREND QUITE WELL...BUT THE SHORT TERM
FORECAST CHALLENGE REGARDS THE DEVELOPMENT OF AFTERNOON
SHOWERS. AIR MASS REMAINS DRY THIS MORNING...BUT STRONG FORCING
AND MOISTURE STREAMING NORTHWARD AHEAD OF THE EJECTING SHORT WAVE
WILL RESULT IN SOME SHOWERS THIS AFTERNOON. MOST OF THESE SHOWERS
AND POSSIBLE STORMS WILL BE HIGH BASED AND MOSTLY CONFINED TO THE
WESTERN SLOPE HIGH COUNTRY. IN THE NEAR SHORT TERM...THE HRRR MODEL
KEEPS THE FORECAST AREA DRY THROUGH 18Z. WILL GO ALONG WITH THIS
IDEA...BUT EXPECT SPOTTY SHOWERS TO DEVELOP LATE THIS AFTERNOON AS
UPWARD FORCING ARRIVES. THE DRY SUB CLOUD ENVIRONMENT MAY ENHANCE
THE GUSTY WIND POTENTIAL.
THE FIRST EJECTING SHRT WAVE FROM THE DEVELOPING OFFSHORE PACIFIC
TROF WILL PUSH A SIGNIFICANT COLD FRONT THROUGH THE CWA BEFORE
MIDNIGHT WEDNESDAY. CURRENT TIMING HAS IT MOVING THROUGH THE GRAND
VALLEY AROUND 03Z. GUSTY WINDS WILL PRECEDE AND FOLLOW THE FRONT. I
INCREASED POPS TO THE LIKELY CATEGORY OVER THE NRN MTNS...WITH LOWER
POPS ELSEWHERE. A MUCH COOLER AND MORE WESTERLY FLOW IS EXPECTED
THURSDAY WITH A SERIES OF VORT CENTERS LINED UP TO PASS OVER THE
REGION. ONE FAIRLY ENERGETIC WAVE IS TIMED TO PASS THUR AFTN...WHICH
WILL BRING ANOTHER ROUND OF MTN PCPN AGAIN FAVORING THE NORTH.
LIFTED INDEX ALSO FALLS TO AROUND ZERO SO THERE IS A POSSIBILITY OF
A FEW AFTERNOON TSTMS. CONFIDENCE NOT ALL THAT HIGH RIGHT NOW...SO
WILL LET THE DAY SHIFT REEVALUATE.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 447 AM MDT WED APR 11 2012
A COOL MOIST AND UNSTABLE SOUTHWESTERLY FLOW WILL BE OVER THE REGION
THUR NIGHT THROUGH FRI NIGHT BRINGING SCATTERED SHOWERS FAVORING THE
NRN MTNS AT FIRST. THEN THE FOCUS OF PCPN WILL SHIFT MORE TOWARD THE
SRN MTNS FRIDAY AND FRIDAY NIGHT. AT THE SAME TIME THE SNOW LEVEL
WILL FALL TO AROUND 7000 FEET OR MAYBE EVEN A LITTLE LOWER. THIS
PUTS THE SAN JUANS UNDER THE GUN FOR POSSIBLE WINTER HIGHLIGHTS. THE
GFS SHOWS THE HIGHEST AMOUNTS SO FAR WITH THE NAM PRODUCING LESSER
AMOUNTS...WHICH IS KIND OF ODD. THE GRAND MESA MAY ALSO GET IN ON
THE ACTION IF THE GFS PANS OUT. MEANWHILE THE PACIFIC TROF HAS SINCE
CLOSED OFF AND WILL HAVE MOVED EASTWARD TO BE NEAR LAS VEGAS BY
EARLY SAT MORNING.
MEDIUM RANGE MODELS HAVE NOT CONVERGED TO A SOLUTIONS FOR THE
SATURDAY THROUGH MONDAY TIME FRAME. PREFER THE SLOWER GFS
EVOLUTION OF THE CLOSED LOW CIRCULATION...BUT CANNOT IGNORE THE
MORE PROGRESSIVE ECMWF AND CANADIAN MODEL SOLUTIONS AS THEY TEND
TO VERIFY BETTER. THE CONSENSUS OUTPUT PROVIDES A REASONABLE
COMPROMISE THAT DEPICTS COOL AND UNSETTLED WEATHER THROUGH MONDAY.
IF THE GFS VERIFIES THE BEST...THEN THIS WEEKENDS STORM MAY
PRODUCE GENEROUS AMOUNTS OF PCPN AS THE CLOSED LOW WILL BE QUASI
STATIONARY OVER THE FORECAST AREA. STRONG DYNAMICAL LIFT BRINGS
POTENTIALLY HEAVY SNOW INTO THE SAN JUAN MOUNTAINS...THEN THE
FOCUS SHIFTS NORTHWARD AS THE GFS SHOWS WRAPAROUND MOISTURE AND A
TROWAL SIGNATURE. AT ANY RATE...LOOKS LIKE AN ACTIVE WEATHER
PATTERN THROUGH THE WEEKEND AND POSSIBLY LASTING INTO MONDAY WITH
NO CRITICAL FIRE WEATHER DAYS IN THE OFFERING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 447 AM MDT WED APR 11 2012
MECHANICAL TURBULENCE WILL BE THE PRIMARY WEATHER HAZARD TODAY
WITH G40KTS EXPECTED AT VALLEY AIRPORTS THIS AFTERNOON. GUSTY
WINDS WILL PERSIST THROUGH 06Z THIS EVENING...BUT WINDS GRADUALLY
TAPER OFF AFTER 06Z MIDNIGHT TONIGHT.
ISOLATED HIGH BASED SHOWERS WILL DEVELOP OVER WRN COLORADO THIS
AFTERNOON...BECOMING SCATTERED THIS EVENING WITH LOCAL
THUNDERSTORMS. VFR IS EXPECTED AT ALL TAF SITES AND
AIRFIELDS...ALTHOUGH PASSING SHOWERS MAY OBSCURE MOUNTAIN TOPS.
&&
.FIRE WEATHER...
ISSUED AT 317 PM MDT TUE APR 10 2012
NEAR RECORD WARMTH COUPLED WITH LOW HUMIDITY AND STRONG GUSTY WINDS
WILL PRODUCE RED FLAG CONDITIONS WEDNESDAY AFTERNOON AND EVENING.
WINDS WILL BEGIN INCREASING BY MIDDAY AS DAYTIME MIXING BEGINS TO
TAP STRONGER SOUTH TO SOUTHWEST WINDS ALOFT. THE STRONGEST WINDS
ARE EXPECTED LATE IN THE DAY WEDNESDAY. HUMIDITIES SHOULD BE
INCREASING WEDNESDAY EVENING AS A COLD FRONT MOVES THROUGH.
GUSTY WINDS ARE EXPECTED THURSDAY THOUGH NOT AS STRONG AS ON
WEDNESDAY. TEMPERATURES WILL BE SIGNIFICANT COOLER WHICH SHOULD HELP
KEEP HUMIDITIES UP A BIT. A FEW AREAS MAINLY IN THE SOUTHWEST
COLORADO MAY BRIEFLY TOUCH CRITICAL FIRE WEATHER CRITERIA ON
THURSDAY... BUT THE DURATION AND AREAL EXTENT DOES NOT WARRANT ANY
HIGHLIGHT AT THIS TIME. SOMETHING TO WATCH...HOWEVER. AT LEAST
SCATTERED WETTING PRECIPITATION IS POSSIBLE THIS WEEKEND.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...RED FLAG WARNING FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR
COZ200>203-207-290-292-293.
WIND ADVISORY FROM NOON TODAY TO MIDNIGHT MDT TONIGHT FOR COZ001-
002-006-007-011-020>022.
UT...RED FLAG WARNING FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR
UTZ430-443-444.
WIND ADVISORY FROM NOON TODAY TO MIDNIGHT MDT TONIGHT FOR UTZ022-
024-027-029.
&&
$$
UPDATE...EH
SHORT TERM...MC
LONG TERM...PF
AVIATION...PF
FIRE WEATHER...JAD
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
447 AM MDT WED APR 11 2012
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 447 AM MDT WED APR 11 2012
SURFACE GRADIENT WINDS INCREASE TODAY AS A SUB 1000 MB SURFACE LOW
TRACKS ACROSS NE UTAH AND EXTREME NW COLORADO LATE IN THE DAY.
SHORT WAVE DISTURBANCE MOVING INTO SRN CALIFORNIA THIS MORNING
PIVOTS NORTHEAST...THIS ALLOWS UPPER LEVEL DIVERGENCE TO INCREASES
THE NEGATIVE TILT SHORT WAVE APPROACHES ERN UTAH THIS AFTERNOON. SUSTAINED
700 MB WINDS/TEMPS AT 35 KNOTS/AROUND +7C AND WILL TRANSLATE TO
THE SURFACE AS STRONG GUSTY WINDS WITH NEAR RECORD WARMTH. THE
FORECAST GRIDS REFLECT THIS TREND QUITE WELL...BUT THE SHORT TERM
FORECAST CHALLENGE REGARDS THE DEVELOPMENT OF AFTERNOON
SHOWERS. AIR MASS REMAINS DRY THIS MORNING...BUT STRONG FORCING
AND MOISTURE STREAMING NORTHWARD AHEAD OF THE EJECTING SHORT WAVE
WILL RESULT IN SOME SHOWERS THIS AFTERNOON. MOST OF THESE SHOWERS
AND POSSIBLE STORMS WILL BE HIGH BASED AND MOSTLY CONFINED TO THE
WESTERN SLOPE HIGH COUNTRY. IN THE NEAR SHORT TERM...THE HRRR MODEL
KEEPS THE FORECAST AREA DRY THROUGH 18Z. WILL GO ALONG WITH THIS
IDEA...BUT EXPECT SPOTTY SHOWERS TO DEVELOP LATE THIS AFTERNOON AS
UPWARD FORCING ARRIVES. THE DRY SUB CLOUD ENVIRONMENT MAY ENHANCE
THE GUSTY WIND POTENTIAL.
THE FIRST EJECTING SHRT WAVE FROM THE DEVELOPING OFFSHORE PACIFIC
TROF WILL PUSH A SIGNIFICANT COLD FRONT THROUGH THE CWA BEFORE
MIDNIGHT WEDNESDAY. CURRENT TIMING HAS IT MOVING THROUGH THE GRAND
VALLEY AROUND 03Z. GUSTY WINDS WILL PRECEDE AND FOLLOW THE FRONT. I
INCREASED POPS TO THE LIKELY CATEGORY OVER THE NRN MTNS...WITH LOWER
POPS ELSEWHERE. A MUCH COOLER AND MORE WESTERLY FLOW IS EXPECTED
THURSDAY WITH A SERIES OF VORT CENTERS LINED UP TO PASS OVER THE
REGION. ONE FAIRLY ENERGETIC WAVE IS TIMED TO PASS THUR AFTN...WHICH
WILL BRING ANOTHER ROUND OF MTN PCPN AGAIN FAVORING THE NORTH.
LIFTED INDEX ALSO FALLS TO AROUND ZERO SO THERE IS A POSSIBILITY OF
A FEW AFTERNOON TSTMS. CONFIDENCE NOT ALL THAT HIGH RIGHT NOW...SO
WILL LET THE DAY SHIFT REEVALUATE.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 447 AM MDT WED APR 11 2012
A COOL MOIST AND UNSTABLE SOUTHWESTERLY FLOW WILL BE OVER THE REGION
THUR NIGHT THROUGH FRI NIGHT BRINGING SCATTERED SHOWERS FAVORING THE
NRN MTNS AT FIRST. THEN THE FOCUS OF PCPN WILL SHIFT MORE TOWARD THE
SRN MTNS FRIDAY AND FRIDAY NIGHT. AT THE SAME TIME THE SNOW LEVEL
WILL FALL TO AROUND 7000 FEET OR MAYBE EVEN A LITTLE LOWER. THIS
PUTS THE SAN JUANS UNDER THE GUN FOR POSSIBLE WINTER HIGHLIGHTS. THE
GFS SHOWS THE HIGHEST AMOUNTS SO FAR WITH THE NAM PRODUCING LESSER
AMOUNTS...WHICH IS KIND OF ODD. THE GRAND MESA MAY ALSO GET IN ON
THE ACTION IF THE GFS PANS OUT. MEANWHILE THE PACIFIC TROF HAS SINCE
CLOSED OFF AND WILL HAVE MOVED EASTWARD TO BE NEAR LAS VEGAS BY
EARLY SAT MORNING.
MEDIUM RANGE MODELS HAVE NOT CONVERGED TO A SOLUTIONS FOR THE
SATURDAY THROUGH MONDAY TIME FRAME. PREFER THE SLOWER GFS
EVOLUTION OF THE CLOSED LOW CIRCULATION...BUT CANNOT IGNORE THE
MORE PROGRESSIVE ECMWF AND CANADIAN MODEL SOLUTIONS AS THEY TEND
TO VERIFY BETTER. THE CONSENSUS OUTPUT PROVIDES A REASONABLE
COMPROMISE THAT DEPICTS COOL AND UNSETTLED WEATHER THROUGH MONDAY.
IF THE GFS VERIFIES THE BEST...THEN THIS WEEKENDS STORM MAY
PRODUCE GENEROUS AMOUNTS OF PCPN AS THE CLOSED LOW WILL BE QUASI
STATIONARY OVER THE FORECAST AREA. STRONG DYNAMICAL LIFT BRINGS
POTENTIALLY HEAVY SNOW INTO THE SAN JUAN MOUNTAINS...THEN THE
FOCUS SHIFTS NORTHWARD AS THE GFS SHOWS WRAPAROUND MOISTURE AND A
TROWAL SIGNATURE. AT ANY RATE...LOOKS LIKE AN ACTIVE WEATHER
PATTERN THROUGH THE WEEKEND AND POSSIBLY LASTING INTO MONDAY WITH
NO CRITICAL FIRE WEATHER DAYS IN THE OFFERING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 447 AM MDT WED APR 11 2012
MECHANICAL TURBULENCE WILL BE THE PRIMARY WEATHER HAZARD TODAY
WITH G40KTS EXPECTED AT VALLEY AIRPORTS THIS AFTERNOON. GUSTY
WINDS WILL PERSIST THROUGH 06Z THIS EVENING...BUT WINDS GRADUALLY
TAPER OFF AFTER 06Z MIDNIGHT TONIGHT.
ISOLATED HIGH BASED SHOWERS WILL DEVELOP OVER WRN COLORADO THIS
AFTERNOON...BECOMING SCATTERED THIS EVENING WITH LOCAL
THUNDERSTORMS. VFR IS EXPECTED AT ALL TAF SITES AND
AIRFIELDS...ALTHOUGH PASSING SHOWERS MAY OBSCURE MOUNTAIN TOPS.
&&
.FIRE WEATHER...
ISSUED AT 317 PM MDT TUE APR 10 2012
NEAR RECORD WARMTH COUPLED WITH LOW HUMIDITY AND STRONG GUSTY WINDS
WILL PRODUCE RED FLAG CONDITIONS WEDNESDAY AFTERNOON AND EVENING.
WINDS WILL BEGIN INCREASING BY MIDDAY AS DAYTIME MIXING BEGINS TO
TAP STRONGER SOUTH TO SOUTHWEST WINDS ALOFT. THE STRONGEST WINDS
ARE EXPECTED LATE IN THE DAY WEDNESDAY. HUMIDITIES SHOULD BE
INCREASING WEDNESDAY EVENING AS A COLD FRONT MOVES THROUGH.
GUSTY WINDS ARE EXPECTED THURSDAY THOUGH NOT AS STRONG AS ON
WEDNESDAY. TEMPERATURES WILL BE SIGNIFICANT COOLER WHICH SHOULD HELP
KEEP HUMIDITIES UP A BIT. A FEW AREAS MAINLY IN THE SOUTHWEST
COLORADO MAY BRIEFLY TOUCH CRITICAL FIRE WEATHER CRITERIA ON
THURSDAY... BUT THE DURATION AND AREAL EXTENT DOES NOT WARRANT ANY
HIGHLIGHT AT THIS TIME. SOMETHING TO WATCH...HOWEVER. AT LEAST
SCATTERED WETTING PRECIPITATION IS POSSIBLE THIS WEEKEND.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...RED FLAG WARNING FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR
COZ200>203-207-290-292-293.
WIND ADVISORY FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR
COZ001-002-006-011-020>022.
UT...RED FLAG WARNING FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR
UTZ430-443-444.
WIND ADVISORY FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR
UTZ022-027-029.
&&
$$
SHORT TERM...MC
LONG TERM...PF
AVIATION...PF
FIRE WEATHER...JAD
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
418 AM MDT WED APR 11 2012
.SHORT TERM...SWLY FLOW ALOFT WILL INCREASE THRU THIS AFTN AS AN
UPPER LEVEL DISTURBANCE APPROACHES THE AREA. MEANWHILE A RATHER
STG SFC GRADIENT WILL EXIST AS LOW PRESSURE RESIDES IN THE MTNS
WITH A SFC HIGH OVER THE CENTRAL US. THIS RESULTS IN RATHER STG
SELY LOW LVL FLOW EAST OF THE MTNS. MEANWHILE NONE OF THE SHORT
RANGE MODELS AGREE ON WHERE A CONVERGENCE ZONE MAY DVLP BY MID TO
LATE AFTN. THE HI RES WRF HAS A CONVERGENCE ZONE JUST EAST OF
DENVER WHILE THE HRRR HAS IT RIGHT OVER DENVER WHILE THE NAM HAS
NO BNDRY AT ALL WITH ESE WINDS FLOWING INTO THE FOOTHILLS. CAPES
BY LATE AFTN ARE FCST BE AROUND 1000 J/KG WITH NO CAP IF HIGHS
RISE INTO THE MID 70S SO SHOULD SEE AT LEAST SOME WIDELY SCT TSTMS
DVLP IN IN AND NR THE FOOTHILLS AND IN THE MTNS. OVER THE PLAINS
THE AIRMASS WILL BE MUCH MORE STABLE SO ANY CONVECTION THRU THE
EARLY EVENING HOURS SHOULD STAY WEST OF A FORT MORGAN TO LIMON
LINE. SHEAR PROFILE WILL BECOME MORE FAVORABLE BY LATE AFTN INTO
THE EARLY EVENING HOURS SO COULD SEE A FEW SVR STORMS WITH
MARGINAL LARGE HAIL FROM DENVER SOUTH TO THE PALMER DIVIDE. IF
THERE IS A CONVERGENCE ZONE LIKE THE HRRR AND HI RES WRF SHOW LOW
LVL FLOW WILL BE ENHANCED ALONG THE BNDRY INCREASING HELICITY
VALUES SO NOT TOTALLY IMPOSSIBLE A BRIEF TORNADO COULD OCCUR. AS
FAR AS HIGHS YESTERDAY READINGS WERE AROUND 5 DEGREES WARMER THAN
EXPECTED. FOR THIS AFTN HIGHS WILL BE TRICKY DUE TO LINGERING
STATUS OVER THE PLAINS AND POSSIBLE CONVERGENCE ZONE NR DENVER.
HIGHS MADE NOT GET ABOVE ZONE OVER THE FAR NERN CORNER WHILE
READINGS CLOSER TO DENVER RISE INTO THE MID TO UPPER 70S OVER THE
ERN AD SRN SUBURBS WHILE READINGS OVER THE NRN AND WRN AREAS ONLY
REACH THE UPPER 60S TO LOWER 70S. WILL KEEP RED FLAG WARNING FOR
PARK COUNTY AND THE HIGHER VALLEYS DUE TO GUSTY WINDS...LOW
HUMIDITY AND POSSIBLE DRY LIGHTNING.
FOR TONIGHT THE UPPER LEVEL DISTURBANCE WILL MOVE QUICKLY ACROSS
WRN CO. CROSS-SECTIONS SHOW ENOUGH MOISTURE WITH THIS FEATURE
COULD BRING A CHC OF SNOW SHOWERS TO ZONES 31 AND 33 AFTER
MIDNIGHT. OTHERWISE OVER NERN CO WILL SEE SOME LINGERING TSTMS IN
THE EARLY EVEING HOURS ALONG THE FRONT RANGE HOWEVER FURTHER EAST
AIRMASS WILL REMAIN FAIRLY STABLE SO WILL ONLY MENTION A CHC OF
SHOWERS WITH ISOLD TSTMS.
.LONG TERM...THIS WEEKEND APPEARS TO HAVE THE POTENTIAL TO BE
RATHER UNSETTLED AS A BROAD UPPER TROUGH SETTLES OVER THE WESTERN
U.S. AND THEN CUTS OFF SOMEWHERE IN THE VICINITY OF THE FOUR
CORNERS LATE IN THE WEEKEND. THE GFS HAS BEEN HINTING THAT THIS
SYSTEM COULD CONTAIN QUITE A BIT OF PRECIPITATION WHEN LOOKING AT
THE MODEL QPG FIELDS...INITIALLY OVER NORTHERN CALIFORNIA AND THE
SIERRA NEVADA...BUT THEN OVER COLORADO BY ABOUT SUNDAY. OTHER
MODELS HAVE NOT PRODUCED QUITE AS MUCH PRECIPITATION AS THE GFS...
BUT HAVE BEEN SUPPORTING THE IDEA THAT AN UPPER LEVEL SYSTEM WILL
AFFECT COLORADO WEATHER THROUGH THE WEEKEND. EVEN THE LATEST NAM
IS NOW SHOWING THE EASTERN PARTS OF THIS WEATHER SYSTEM BEING OVER
COLORADO SATURDAY AFTERNOON. THE Q-G DIAGNOSTICS PACKAGE FROM THE
GFS SHOWS A 30-36 HOUR PERIOD WITH STRONG LIFT OVER NORTHERN
COLORADO AS THE UPPER LOW PASSES OVER THE FOUR CORNERS. ALL THIS
BEING SAID...THERE IS STILL PLENTY OF UNCERTAINTY WHETHER THE
SYSTEM WILL EVOLVE LIKE THE GFS DEPICTS...BUT MOST OF THE GFS
ENSEMBLE MEMBERS SUPPORT THE OPERATIONAL SOLUTION. THE MAIN PERIOD
OF PRECIPITATION LOOKS LIKE IT WILL BE SATURDAY NIGHT AND SUNDAY.
THE OTHER UNCERTAINTY IS HOW WARM OR COLD THE SYSTEM WILL BE.
LOCATIONS ON THE PLAINS MAY REMAIN IN THE MID TO UPPER 30S ON
SUNDAY MORNING...LEADING TO RAIN OR A MIX OF RAIN AND SNOW WITH
SNOW LEVELS AROUND 6000 FEET OR HIGHER. THE MOISTURE IS CERTAINLY
GOING TO BE WELCOME...BUT WE WILL HAVE TO WATCH FOR HOW MUCH OF
FALLS IN THE FORM OF FROZEN PRECIPITATION. WITH THE EVENT STILL
OUT AT DAYS 4 AND 5...POPS ARE STILL IN THE CHANCE AND SLIGHT
CHANCE CATEGORY. THE FORECAST FOR THE EARLY PART OF NEXT WEEK IS
GOING TO DEPEND ON WHEN THE UPPER LOW MOVES OUT ONTO THE
PLAINS...ALLOWING UPPER LEVEL RIDGING TO RE-BUILD OVER THE STATE.
FOR NOW A SLIGHT CHANCE OF PRECIPITATION IS EXPECTED TO CONTINUE
THROUGH TUESDAY MORNING.
&&
.AVIATION...
A WELL DEFINED DENVER CYCLONE WAS NR DIA EARLY THIS MORNING WITH
ABUNDANT STRATUS OVER THE PLAINS WHICH WAS WRAPPING AROUND THE
BACK SIDE OF THE LOW AND SHOULD AFFECT BOTH BJC AND DIA THROUGH
THE MID MORNING HOURS WITH LIFR CONDITIONS. COULD SEE SOME LOCALLY DENSE
FOG AROUND DIA WHICH ALWAYS SEEMS TO HAPPEN IN THIS TYPE OF
SCENARIO MORE TIMES THAN NOT. WILL GRADUALLY BREAK UP LOW CLOUDS
BY 16Z. FOR THIS AFTN AM NOT REAL CONFIDENT IN HOW SFC FEATURES
WILL DEVELOP AS SHORT RANGE MODELS ARE NOT IN GOOD AGREEMENT WITH
PLACEMENT OF POSSIBLE CONVERGENCE ZONE BY MID TO LATE AFTN. IF
BNDRY ENDS UP WEST OF DIA THEN GUSTY SELY WINDS OF 20-30 MPH MAY
DVLP BY 21Z HOWEVER IF IT ENDS UP JUST TO THE EAST THEN WINDS
COULD BE MORE NE AND NOT AS STG. FOR NOW WILL GO WITH THE BNDRY
BEING WEST OF THE AIRPORT. AFTER 22Z THRU 02Z WIDELY SCT TSTMS
COULD AFFECT THE AIRPORT. THERE IS ENOUGH SHEAR AND INSTABILITY
FOR A SVR STORM THAT COULD PRODUCE BRIEF HAIL TO ONE INCH IN
DIAMETER AND GUSTY WINDS TO 50 MPH ALTHOUGH CHANCES ARE PROBABLY
AROUND 10%.
FOR TONIGHT WINDS SHOULD BE MORE SLY AND COULD REMAIN RATHER
GUSTY THROUGH MIDNIGHT WITH SPEEDS IN THE 20-30 MPH RANGE. AFTER
MIDNIGHT WINDS SHOULD BECOME MORE SSW WITH LIGHER SPEEDS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON TO 8 PM MDT THIS EVENING FOR
COZ211-213-214.
&&
$$
SHORT TERM...RPK
LONG TERM....DANKERS
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS NEW YORK NY
156 AM EDT WED APR 11 2012
.SYNOPSIS...
BROAD LOW PRESSURE BUILDS EAST OF THE REGION THROUGH WEDNESDAY. AN
UPPER LEVEL DISTURBANCE WILL MOVE THROUGH THE REGION ON THURSDAY AS
CANADIAN HIGH PRESSURE BUILDS TO OUR WEST. THE HIGH WILL SLIDE
SOUTH OF THE AREA FRIDAY NIGHT AND SATURDAY. A WARM FRONT WILL
LIFT THROUGH THE AREA ON SUNDAY WITH A COLD FRONT SLOWLY
APPROACHING FROM THE NORTH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
OVERNIGHT UPDATE...SLIGHT ADJUSTMENTS TO DEWPOINTS...TEMPS...CLOUD
COVERAGE AND POPS. SKY CONDITIONS RANGE FROM MOSTLY TO PARTLY
CLOUDY. WENT DRY UNTIL EARLY WEDNESDAY MORNING WITH MOST MODEL
SOLUTIONS INCLUDING 00Z HRRR DEPICTING BARELY ANY SHOWER ACTIVITY.
ALOFT...BRIEF NEGATIVE VORTICITY ADVECTION WILL KEEP VERTICAL
FORCING MINIMIZED GOING INTO THE MORNING. STILL WITH AMBIENT TEMPS
IN PORTIONS OF INTERIOR AREAS AND HIGHER ELEVATIONS COULD HAVE
SOME RAIN AND SNOW SHOWERS POSSIBLE BEFORE QUICKLY BECOMING JUST
PLAIN RAIN SHOWERS. LOWS ADJUSTED DOWN A FEW DEGREES IN PLACES
WHERE RADIATIONAL COOLING IS GREATER WITH LIGHT WINDS IN PLACE
WITH RANGE OF UPPER 20S TO LOWER 30S. ELSEWHERE MOSTLY UPPER 30S
TO LOWER 40S FOR LOWS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
LOW PRES OVER EASTERN CANADA DIPS INTO NEW ENGLAND WEDNESDAY
MORNING. MEANWHILE...LOW PRES MOVING OFF THE MID-ATLANTIC COAST
WILL TRACK NORTHEAST AND MERGE WITH THE AFOREMENTIONED LOW OVER
THE GULF OF MAINE WEDNESDAY AFTERNOON.
NORTHERLY FLOW WILL USHER COOLER TEMPS INTO THE REGION...WITH
HIGHS TOPPING OFF IN THE 50S. MEANWHILE...WRAP-AROUND MOISTURE
WILL SPILL INTO THE LOCAL AREA...RESULTING IN SCATTERED SHOWERS
OVER THE REGION. ANY SHOWERS WILL TAPER OFF FROM WEST TO EAST
WEDNESDAY NIGHT AS THE OCEANIC LOW DEPARTS.
MAV/MET BLEND USED FOR TEMPERATURES WITH HIGHS WEDNESDAY A FEW
DEGREES BELOW NORMAL.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
LITTLE RELIEF FROM THE DRY WEATHER IS EXPECTED THROUGH AT LEAST
EARLY NEXT WEEK.
UPPER TROUGH AXIS WILL SLOWLY TRACK TO THE EAST THROUGH THE END OF
THE WEEK. THE COMBINATION OF A SPOKE OF VORTICITY ROUNDING THE
BACKSIDE OF THE TROUGH AND A COLD POOL ALOFT (AROUND -30C AT H5) IS
EXPECTED TO PRODUCE SOME SCT SHOWERS ACROSS THE AREA DURING THE
AFTERNOON AND EARLY EVENING HOURS. SOME UNCERTAINTY WITH HOW SPEED
OF TROUGH EXITING SO HAVE CHANCE POPS ACROSS THE AREA...HIGHEST E
WHERE BEST CHANCES ARE. INSTABILITY IS LACKING...SO NO THUNDER
FORECASTED. CHANCES OF A WIDESPREAD WETTING RAIN ARE RELATIVELY
LOW.
HEIGHTS THEN GRADUALLY RISE INTO THE WEEKEND WITH RIDGING BUILDING
TOWARDS THE AREA AT THE SFC AND ALOFT. TEMPS WILL GRADUALLY INCREASE
THROUGH THE WEEKEND AS A RESULT. THE CENTER OF THE SFC HIGH WILL
BUILD TO OUR SOUTH ON FRI NIGHT AND SAT WITH WINDS BACKING TO THE
SW. A WARM FRONT WILL MOVE ACROSS THE AREA ON SUNDAY BRINGING
ANOTHER CHANCE FOR LIGHT AMOUNTS OF RAINFALL. THE REGION WILL REMAIN
WARM SECTORED INTO TUESDAY AS A COLD FRONT SLOWLY SAGS SOUTHWARD
FROM NEW ENGLAND.
12Z GFS IS COMING INTO BETTER AGREEMENT WITH LAST 2 EC RUNS POINTING
TO ANOMALOUSLY WARM PATTERN ESTABLISHING ITSELF BY EARLY NEXT WEEK.
MODEL SPECTRUM INDICATES VERY LARGE VARIATION IN MAX T BOTH MON AND
TUE...RANGING FROM LOWER 50S TO LOWER 80S AT KEWR. HAVE TRENDED
WARMER FROM PREVIOUS FORECAST...BUT CLOUD COVER FROM AN APPROACHING
COLD FRONT HAS THE POTENTIAL TO LIMIT HEATING.
FIRE WEATHER WILL REMAIN A CONCERN...ESPECIALLY SAT THROUGH MON
WITH A STRONG SW FLOW DEVELOPING. RH LEVELS SHOULD STEADILY RISE
IN THIS REGIME...HOWEVER THE POTENTIAL FOR RH TO DROP BELOW 30
PERCENT EXISTS DUE TO DAYTIME MIXING.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AN AREA OF LOW PRESSURE DEVELOPING OFF THE MID-ATLANTIC COAST
OVERNIGHT...WILL TRACK NORTHEAST TO NEAR NOVA SCOTIA INTO THIS
EVENING.
PREDOMINATELY VFR. CEILINGS FROM 3100-6000 FT LIKELY FROM LATE
THIS MORNING THROUGH THIS EVENING...WITH A SMALL CHANCE OF HIGH
END MVFR CEILINGS IN ANY ISOLD/SCT -SHRA. COVERAGE OF ANY -SHRA
FROM LATE THIS MORNING INTO THIS EVENING WILL BE SPOTTY...SO DO
NOT HAVE ENOUGH CONFIDENCE TO REFLECT AT ANY GIVEN TAF SITE AT
THIS TIME.
WINDS START OUT LIGHT AND VARIABLE...EXCEPT WNW AT JUST UNDER 10
KT AT KEWR/KLGA/KJFK. WINDS SHOULD BECOME NNW-NW THROUGHOUT AT
6-10 KT STARTING AROUND 12Z. COASTAL TERMINALS SHOULD SEE WINDS
BACK TO THE WNW AROUND MIDDAY...WITH OTHER TERMINALS NW. WIND
SPEEDS SHOULD INCREASE TO AROUND 10 KT AROUND MIDDAY THEN TO 10-15
KT WITH GUSTS UP TO 20 KT IN THE AFTERNOON...WITH COASTAL
TERMINAL WINDS VEERING BACK TO THE NW BY LATE AFTERNOON.
WINDS SHOULD LOSE THEIR GUSTINESS BY AROUND MIDNIGHT AND VEER MORE
TOWARDS THE NNW.
OUTLOOK FOR 06Z THURSDAY THROUGH SUNDAY...
.LATE WEDNESDAY NIGHT...VFR.
.THURSDAY-THURSDAY EVENING...CEILINGS 3100-5000 FT LIKELY FROM LATE
MORNING INTO THE AFTERNOON...WITH MVFR CEILINGS POSSIBLE IN ANY
ISOLD/SCT -SHRA. GUSTY WINDS POSSIBLE.
.LATE THURSDAY NIGHT THROUGH FRIDAY NIGHT...VFR.
.SATURDAY-SUNDAY...PRIMARILY VFR...WITH MVFR POSSIBLE SATURDAY
NIGHT/SUNDAY MORNING. GUSTY WINDS POSSIBLE.
&&
.MARINE...
SUB-ADVISORY CONDITIONS ARE EXPECTED ON THE WATERS TONIGHT THROUGH
WEDNESDAY NIGHT WITH A RELATIVELY LOOSE PRESSURE GRADIENT OVER THE
AREA WATERS.
GUSTS MAY REACH SCA LEVELS ON THU AS THE PRES GRADIENT TIGHTENS.
OTHERWISE...TRANQUIL CONDITIONS UNTIL SAT WHEN AN INCREASING SW FLOW
WILL CAUSE WINDS AND SEAS TO INCREASE ONCE AGAIN. LOW LEVEL
INVERSION MAY RESULT IN MARGINAL GUSTS ON THE WATERS...BUT SEAS
SHOULD BUILD TO 5 TO 7 FT.
&&
.FIRE WEATHER...
FOR WEDNESDAY...NORTHERLY WINDS WILL AVERAGE 10-15 MPH...BUT FREQUENT
GUSTS OF UP TO 25 MPH ARE NOT EXPECTED. ADDITIONALLY...MINIMUM RH
VALUES WILL RANGE FROM 35 TO 40 PERCENT ACROSS THE REGION...SHORT OF
CRITERIA FOR CONSIDERATION OF A FIRE WEATHER WATCH.
&&
.HYDROLOGY...
NO SIGNIFICANT WIDESPREAD PRECIPITATION IS EXPECTED THROUGH THE
WEEK.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MPS
NEAR TERM...JM
SHORT TERM...MPS
LONG TERM...12
AVIATION...MALOIT
MARINE...MPS/12
FIRE WEATHER...
HYDROLOGY...MPS
AREA FORECAST DISCUSSION
NWS MIAMI FL
237 PM EDT WED APR 11 2012
.DISCUSSION...A MID/UPPER LEVEL TROUGH OVER FLORIDA WILL PULL OUT
AND BE REPLACED BY A RIDGE OVER THE WEEKEND AND INTO THE EARLY TO
MIDDLE PART OF NEXT WEEK. A WEAK SURFACE COLD FRONT NOW OVER NORTH
CENTRAL FLORIDA WILL MOVE DOWN THE STATE AND ACROSS SOUTH FL WHILE
BECOMING DIFFUSE ON THU-THU NIGHT. A SLIGHT INCREASE IN MOISTURE
ASSOCIATED WITH THIS WEAK FEATURE SHOULD ALLOW FOR ISOLATED
SHOWERS TO DEVELOP ACROSS THE INTERIOR AND EAST COAST ON
THURSDAY, ALONG WITH THE POTENTIAL FOR A FEW THUNDERSTORMS. THIS
AFTERNOON IT LOOKS LIKE THE LACK OF MOISTURE COULD INHIBIT SHOWER
AND POSSIBLE TSTORM DEVELOPMENT ALL TOGETHER. HOWEVER, KEPT THE
SLIGHT CHANCE POPS INTERIOR-EAST GIVEN THE CU FIELD ON SATELLITE
IMAGERY AND THE HRRR CONTINUING TO SHOW SOME DEVELOPMENT.
CONFIDENCE IN DEVELOPMENT IS LOW THIS AFTERNOON WITH MODERATE
CONFIDENCE FOR THURSDAY.
THE FRONTAL BOUNDARY WILL WEAKEN THU NIGHT-FRI...BUT JUST ENOUGH
MOISTURE MAY REMAIN ACROSS SOUTHEAST AREAS TO ALLOW FOR A FEW
SHOWERS TO MOVE ONSHORE THE ATLANTIC COAST ON AN INCREASING
NE WIND FLOW. SO ADDED A SLIGHT CHANCE OF SHOWERS FOR BROWARD
/MIAMI-DADE FRI.
A BUILDING RIDGE OVER THE WEEKEND AND INTO THE EARLY TO MIDDLE
PART OF NEXT WEEK WILL RESULT IN A TRANQUIL WEATHER REGIME. GFS
AND ECMWF ARE IN AGREEMENT ON THIS.
RIP CURRENTS WILL BECOME AN INCREASING CONCERN AT THE ATLANTIC
BEACHES THIS WEEKEND AND INTO NEXT WEEK DUE TO THE INCREASING
ONSHORE WIND FLOW.
SLIGHTLY COOLER TEMPS AND DEWPOINTS IN THE 50S OVER THE WEEKEND
WILL GRADUALLY INCREASE NEXT WEEK AS WINDS TURN SOUTHEAST.
&&
.MARINE...LOW WINDS/SEAS WILL CONTINUE UNTIL WINDS INCREASE BEHIND
THE FRONT ESPECIALLY THIS WEEKEND. THIS WILL LEAD TO INCREASE SEAS
ESPECIALLY IN THE GULF STREAM OVER THE WEEKEND. WINDS COULD
APPROACH SMALL CRAFT ADVISORY CONDITIONS IN THE ATLANTIC THIS
WEEKEND...NEAR 20 KT.
&&
.FIRE WEATHER...MIN RELATIVE HUMIDITIES BELOW 35 PERCENT WILL
OCCUR OVER GLADES, HENDRY, AND INLAND COLLIER COUNTIES THIS
AFTERNOON WHERE A FIRE DANGER STMT REMAINS IN EFFECT. RH`S WILL
MODIFY A BIT THU-FRI BUT STILL COULD FALL DOWN TO NEAR CRITICAL
LEVELS SO THIS WILL NEED TO BE MONITORED.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 65 82 65 81 / 10 20 20 10
FORT LAUDERDALE 69 83 69 82 / 10 20 20 20
MIAMI 68 84 68 82 / 10 20 20 20
NAPLES 64 85 63 84 / - 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...57/GREGORIA
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS MIAMI FL
144 PM EDT WED APR 11 2012
.AVIATION...
SEA BREEZE WILL CONTINUE TO SET UP ALONG THE EAST COAST TERMINALS
AND ALONG THE GULF COAST AT KAPF THROUGH THE NEXT FEW HOURS. AS A
RESULT...WEAK CONVERGENCE ALONG THE INTERIOR MAY SPARK A FEW
SHRAS/TSRAS. IF THIS HAPPENS...DO NOT THINK COVERAGE WILL BE
ENOUGH TO WARRANT A MENTION AT ANY TAF SITE. OTHERWISE...VFR
CONDITIONS WILL PREVAIL THROUGH THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 1021 AM EDT WED APR 11 2012/
UPDATE...MORNING SOUNDING ANALYSIS OF THE MIAMI SOUNDING SHOWS
NARROW CAPE WITH MODIFIED SURFACE CAPE AROUND 900 J/KG. PWAT IS
ONLY 1.07 INCHES, SO THE STRUGGLE TODAY WILL BE WITH REGARDS TO
MOISTURE, OR LACK THEREOF. MEAN FLOW IS WESTERLY SO ONCE SEA
BREEZES DEVELOP THE BEST CONVERGENCE WILL BE INTERIOR/ATLANTIC
COAST. HRRR SHOWS SOME CONVECTIVE DEVELOPMENT BY LATE AFTERNOON
OVER ESPECIALLY BROWARD/MIAMI-DADE COUNTIES. MAY BE TOUGH TO GET
MUCH OF ANYTHING GOING DUE TO THE LACK OF MOISTURE. HOWEVER, OPTED
TO MAINTAIN THE SLIGHT CHANCE OF SHRA/TSTORMS AS THEY JUST CANNOT
BE RULED OUT. SO NO UPDATES TO THE FORECAST WILL BE MADE THIS
MORNING. /GREGORIA
PREV DISCUSSION... /ISSUED 738 AM EDT WED APR 11 2012/
AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGHOUT THE FORECAST PERIOD. LIGHT
AND VARIABLE WINDS WILL CONTINUE THROUGH THE EARLY MORNING HOURS
BEFORE A SEA BREEZE DEVELOPS EARLY THIS AFTERNOON ACROSS THE EAST COAST
TERMINALS. THIS WILL CREATE AN EASTERLY FLOW WITH WIND SPEEDS NEAR
10 KNOTS. AT KAPF A SEA BREEZE WILL ALSO DEVELOP THIS AFTERNOON
BRINGING A WESTERLY FLOW WITH WIND SPEEDS NEAR 10 KNOTS. A SHOWER
OR THUNDERSTORM MAY TRY TO DEVELOP ALONG THE SEA BREEZE, HOWEVER, THE
PROBABILITY IS TOO LOW TO MENTION IN THE TAFS. WINDS WILL BECOME
LIGHT AND VARIABLE AGAIN TONIGHT ACROSS ALL SOUTH FLORIDA TERMINALS.
PREV DISCUSSION... /ISSUED 333 AM EDT WED APR 11 2012/
DISCUSSION...LARGE SCALE TROUGH WILL CONTINUE TO DEVELOP OVER THE
EASTERN SEABOARD THROUGH FRIDAY WITH A COUPLE OF SFC BOUNDARIES
MOVING ACROSS S FL. ONE SUCH BOUNDARY IS CURRENTLY MOVING ACROSS
AS I WRITE THIS AND HAS GENERATED A FEW SHRA ACROSS INLAND COLLIER
AND HENDRY COUNTIES THIS EVENING. IN FACT, THESE SHRA ARE FINALLY
JUST NOW DISSIPATING. THE QUESTION IS HOW WILL THIS BOUNDARY
AFFECT THE LOCAL AREA DURING THE DAY? ALL OF THE MODELS PICK UP ON
THE FEATURE BUT WHEREAS THE 12Z NAM RUN YESTERDAY WAS SHOWING AN
INCREASE IN MOISTURE AND INSTABILITY HAS COMPLETELY BACKED OFF ON
THIS IDEA FROM THE 00Z RUN. HOWEVER, THE GFS SHOWS CONVECTIVE
DEVELOPMENT FOR THIS AFTERNOON AND THE SHORT TERM RAPID REFRESH
WHICH NOW GOES OUT TO 18Z IS SHOWING A FEW CONVECTIVE CELLS JUST
BEGINNING TO DEVELOP AFTER 17Z. SO GIVEN THIS AND THE WESTERLY
STEERING FLOW, WILL LEAVE IN MENTION OF SLIGHT CHANCE THUNDER OVER
INTERIOR AND E CST ZONES. A SECOND BOUNDARY WILL MOVE ACROSS THE
REGION THURSDAY MORNING AND ALTHOUGH NOT MUCH IN THE WAY OF
DYNAMICS WILL BE PRESENT, THIS WILL BE THE STRONGER OF THE TWO
BOUNDARIES AND ALL GUIDANCE SHOWS AN INCREASE IN MOISTURE AND
INSTABILITY WHICH HAS BEEN CONSISTENT FOR THE PAST FEW DAYS. FOR
THIS REASON, WILL CONTINUE TO MENTION THE POSSIBILITY OF THUNDER
FOR THURSDAY AFTERNOON TOO. THE MID LEVEL TROUGH WILL BEGIN TO
SHIFT EAST ON FRIDAY AS A LARGE SCALE TROUGH BEGINS TO SET UP OVER
THE INTER-MOUNTAIN WEST WHICH AMPLIFIES A RIDGE FROM THE GOFMEX
INTO THE MISSISSIPPI VALLEY. THIS TROUGH DEVELOPS INTO A MASSIVE
CUT-OFF LOW OVER THE WEEKEND AMPLIFYING THE RIDGE EVEN FURTHER
WHILE AT THE SAME TIME SHIFTING EAST ACROSS THE FL PENINSULA BY
SUNDAY. THE RIDGE WILL ONLY SLOWLY SHIFT EAST THROUGH EARLY NEXT
WEEK SETTING UP A DEEP LAYER RIDGE ACROSS THE PENINSULA SO LOOKS
LIKE A DRY FCST FOR FRIDAY THROUGH THE WEEKEND INTO EARLY NEXT
WEEK. THE GFS DOES SHOW A FEW SURGES OF LOW LEVEL MOISTURE
ROTATING AROUND THE SFC RIDGE WHICH MAY SET UP A FEW ATLANTIC SHRA
BUT TIMING OF THIS WILL BE VERY DIFFICULT SO WILL CONTINUE TO
LEAVE OUT OF FCST FOR NOW.
MARINE...TRANQUIL SEAS WILL CONTINUE ACROSS THE S FL WATERS BUT
WILL DETERIORATE LATE IN THE WEEK AND THE WEEKEND AS A NORTHEAST
TO EAST WIND INCREASES AS HIGH PRESSURE BUILDS. BUT FOR NOW, LOOKS
LIKE THE SEAS IN THE GULF STREAM WILL REMAIN AT 6 FEET OR LESS.
FIRE WEATHER...THE RELATIVE HUMIDITY WILL LIKELY ONCE AGAIN DIP
BELOW 35 PERCENT FOR AROUND FOUR HOURS THIS AFTERNOON ACROSS
GLADES, HENDRY AND INLAND COLLIER COUNTIES WITH AN ERC OF 30-34 SO
WILL ISSUE A FIRE DANGER STATEMENT FOR THOSE AREAS. OTHER AREAS
ACROSS THE INTERIOR WILL SEE THE RH VALUES BETWEEN 35 AND 40
PERCENT FOR A FEW HOURS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 67 81 67 80 / 10 30 20 10
FORT LAUDERDALE 69 83 69 81 / 10 20 20 10
MIAMI 68 84 69 81 / 10 20 20 10
NAPLES 65 84 64 87 / 10 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...57/DG
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS MIAMI FL
1021 AM EDT WED APR 11 2012
.UPDATE...MORNING SOUNDING ANALYSIS OF THE MIAMI SOUNDING SHOWS
NARROW CAPE WITH MODIFIED SURFACE CAPE AROUND 900 J/KG. PWAT IS
ONLY 1.07 INCHES, SO THE STRUGGLE TODAY WILL BE WITH REGARDS TO
MOISTURE, OR LACK THEREOF. MEAN FLOW IS WESTERLY SO ONCE SEA
BREEZES DEVELOP THE BEST CONVERGENCE WILL BE INTERIOR/ATLANTIC
COAST. HRRR SHOWS SOME CONVECTIVE DEVELOPMENT BY LATE AFTERNOON
OVER ESPECIALLY BROWARD/MIAMI-DADE COUNTIES. MAY BE TOUGH TO GET
MUCH OF ANYTHING GOING DUE TO THE LACK OF MOISTURE. HOWEVER, OPTED
TO MAINTAIN THE SLIGHT CHANCE OF SHRA/TSTORMS AS THEY JUST CANNOT
BE RULED OUT. SO NO UPDATES TO THE FORECAST WILL BE MADE THIS
MORNING. /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 738 AM EDT WED APR 11 2012/
AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGHOUT THE FORECAST PERIOD. LIGHT
AND VARIABLE WINDS WILL CONTINUE THROUGH THE EARLY MORNING HOURS
BEFORE A SEA BREEZE DEVELOPS EARLY THIS AFTERNOON ACROSS THE EAST COAST
TERMINALS. THIS WILL CREATE AN EASTERLY FLOW WITH WIND SPEEDS NEAR
10 KNOTS. AT KAPF A SEA BREEZE WILL ALSO DEVELOP THIS AFTERNOON
BRINGING A WESTERLY FLOW WITH WIND SPEEDS NEAR 10 KNOTS. A SHOWER
OR THUNDERSTORM MAY TRY TO DEVELOP ALONG THE SEA BREEZE, HOWEVER, THE
PROBABILITY IS TOO LOW TO MENTION IN THE TAFS. WINDS WILL BECOME
LIGHT AND VARIABLE AGAIN TONIGHT ACROSS ALL SOUTH FLORIDA TERMINALS.
PREV DISCUSSION... /ISSUED 333 AM EDT WED APR 11 2012/
DISCUSSION...LARGE SCALE TROUGH WILL CONTINUE TO DEVELOP OVER THE
EASTERN SEABOARD THROUGH FRIDAY WITH A COUPLE OF SFC BOUNDARIES
MOVING ACROSS S FL. ONE SUCH BOUNDARY IS CURRENTLY MOVING ACROSS
AS I WRITE THIS AND HAS GENERATED A FEW SHRA ACROSS INLAND COLLIER
AND HENDRY COUNTIES THIS EVENING. IN FACT, THESE SHRA ARE FINALLY
JUST NOW DISSIPATING. THE QUESTION IS HOW WILL THIS BOUNDARY
AFFECT THE LOCAL AREA DURING THE DAY? ALL OF THE MODELS PICK UP ON
THE FEATURE BUT WHEREAS THE 12Z NAM RUN YESTERDAY WAS SHOWING AN
INCREASE IN MOISTURE AND INSTABILITY HAS COMPLETELY BACKED OFF ON
THIS IDEA FROM THE 00Z RUN. HOWEVER, THE GFS SHOWS CONVECTIVE
DEVELOPMENT FOR THIS AFTERNOON AND THE SHORT TERM RAPID REFRESH
WHICH NOW GOES OUT TO 18Z IS SHOWING A FEW CONVECTIVE CELLS JUST
BEGINNING TO DEVELOP AFTER 17Z. SO GIVEN THIS AND THE WESTERLY
STEERING FLOW, WILL LEAVE IN MENTION OF SLIGHT CHANCE THUNDER OVER
INTERIOR AND E CST ZONES. A SECOND BOUNDARY WILL MOVE ACROSS THE
REGION THURSDAY MORNING AND ALTHOUGH NOT MUCH IN THE WAY OF
DYNAMICS WILL BE PRESENT, THIS WILL BE THE STRONGER OF THE TWO
BOUNDARIES AND ALL GUIDANCE SHOWS AN INCREASE IN MOISTURE AND
INSTABILITY WHICH HAS BEEN CONSISTENT FOR THE PAST FEW DAYS. FOR
THIS REASON, WILL CONTINUE TO MENTION THE POSSIBILITY OF THUNDER
FOR THURSDAY AFTERNOON TOO. THE MID LEVEL TROUGH WILL BEGIN TO
SHIFT EAST ON FRIDAY AS A LARGE SCALE TROUGH BEGINS TO SET UP OVER
THE INTER-MOUNTAIN WEST WHICH AMPLIFIES A RIDGE FROM THE GOFMEX
INTO THE MISSISSIPPI VALLEY. THIS TROUGH DEVELOPS INTO A MASSIVE
CUT-OFF LOW OVER THE WEEKEND AMPLIFYING THE RIDGE EVEN FURTHER
WHILE AT THE SAME TIME SHIFTING EAST ACROSS THE FL PENINSULA BY
SUNDAY. THE RIDGE WILL ONLY SLOWLY SHIFT EAST THROUGH EARLY NEXT
WEEK SETTING UP A DEEP LAYER RIDGE ACROSS THE PENINSULA SO LOOKS
LIKE A DRY FCST FOR FRIDAY THROUGH THE WEEKEND INTO EARLY NEXT
WEEK. THE GFS DOES SHOW A FEW SURGES OF LOW LEVEL MOISTURE
ROTATING AROUND THE SFC RIDGE WHICH MAY SET UP A FEW ATLANTIC SHRA
BUT TIMING OF THIS WILL BE VERY DIFFICULT SO WILL CONTINUE TO
LEAVE OUT OF FCST FOR NOW.
MARINE...TRANQUIL SEAS WILL CONTINUE ACROSS THE S FL WATERS BUT
WILL DETERIORATE LATE IN THE WEEK AND THE WEEKEND AS A NORTHEAST
TO EAST WIND INCREASES AS HIGH PRESSURE BUILDS. BUT FOR NOW, LOOKS
LIKE THE SEAS IN THE GULF STREAM WILL REMAIN AT 6 FEET OR LESS.
FIRE WEATHER...THE RELATIVE HUMIDITY WILL LIKELY ONCE AGAIN DIP
BELOW 35 PERCENT FOR AROUND FOUR HOURS THIS AFTERNOON ACROSS
GLADES, HENDRY AND INLAND COLLIER COUNTIES WITH AN ERC OF 30-34 SO
WILL ISSUE A FIRE DANGER STATEMENT FOR THOSE AREAS. OTHER AREAS
ACROSS THE INTERIOR WILL SEE THE RH VALUES BETWEEN 35 AND 40
PERCENT FOR A FEW HOURS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 67 81 67 / 20 10 30 20
FORT LAUDERDALE 84 69 83 69 / 20 10 20 20
MIAMI 84 68 84 69 / 20 10 20 20
NAPLES 82 65 84 64 / 10 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
636 PM EDT WED APR 11 2012
...PATCHY FROST POSSIBLE WELL INLAND THURSDAY MORNING...
.SYNOPSIS...
COOL AND DRY HIGH PRESSURE WILL GRADUALLY BUILD INTO THE REGION
THROUGH THE LATTER PART OF THE WEEK. OVER THE WEEKEND...THE HIGH
WILL SLIDE OFF THE SOUTHEAST COAST AND REMAIN THERE THROUGH EARLY
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
THE POTENTIAL FOR FROST IS THE PRIMARY CONCERN TONIGHT. MODELS
SHOW A SECONDARY SURGE OF COOLER AIR ADVECTING IN FROM THE NORTH
OVERNIGHT AS THE TAIL END OF A SHORTWAVE ROUNDING THE BASE OF THE
UPPER LOW SPINNING OVER THE NORTHEAST U.S. PIVOTS OFFSHORE. THIS
SURGE OF COOLER AIR WILL PUSH OVERNIGHT LOWS WELL INTO THE 30S
AWAY FROM THE BEACHES BY SUNRISE THURSDAY WITH LOWS DROPPING INTO
THE MID 30S WELL INLAND AND AWAY FROM LAKES MOULTRIE AND MARION.
LOCAL FROST TOOLS SUGGEST THERE MAY BE JUST ENOUGH MIXING IN THE
BOUNDARY LAYER TO PREVENT SIGNIFICANT FROST FORMATION AS
TEMPERATURES DROP BELOW 36 DEGREES...SO WILL CONTINUE TO HOLD OFF
ON THE ISSUANCE OF A FROST ADVISORY AND MAINTAIN A MENTION OF
PATCHY FROST ALONG AND NORTH OF A PERKINS-HILLTONIA-CROCKETVILLE-
CANADYS-RIDGEVILLE-JAMESTOWN LINE /AND AWAY AND DOWNWIND FROM
LAKES MOULTRIE AND MARION INCLUDING MONCKS CORNER/. THE FROST
POTENTIAL WILL BE CAREFULLY MONITORED THROUGHOUT THE EVENING AS
ANY DECREASE IN THE EXPECTED SPEEDS WILL PUSH BOUNDARY LAYER
CONDITIONS INTO MORE FAVORABLE FROST FORMATION TERRITORY.
NO MAJOR CHANGES WERE MADE TO OUR GRIDDED AND TEXT FORECASTS FOR
THE EARLY EVENING UPDATE. ONLY MINOR TWEAKS WERE MADE TO REFLECT
SHORT TERM TRENDS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
A DEEP LAYER RIDGE WILL CONTINUE TO BUILD ACROSS THE AREA FROM THE
WEST AS A STRONG UPPER LEVEL TROUGH AXIS MOVES EASTWARD INTO THE
ATLANTIC THROUGH THE PERIOD. TEMPERATURES WILL BE BELOW
NORMAL...ESPECIALLY MIN TEMPS FOR THURSDAY...AND FRIDAY THEN
MODERATING TO ABOVE NORMAL BY SATURDAY.
THURSDAY...MODERATELY STRONG HIGH PRESSURE...CENTERED OVER THE OH
RIVER VALLEY...WILL EXTEND ACROSS THE ENTIRE SE U.S.. AFTER A COLD
MORNING START...THE COLD ADVECTION SHOULD BE OVER BY EARLY IN THE
DAY. HOWEVER...MAX TEMPS STILL NOT EXPECTED TO GET OUT OF THE UPPER
60S NORTH TO LOWER 70S SOUTH WITH SUNNY SKIES AND LIGHT ENE WINDS.
THURSDAY NIGHT...A SURFACE HIGH PRESSURE RIDGE WILL BE RIGHT OVER
THE AREA WITH LIGHT TO CALM WINDS AND CLEAR SKIES. THIS WILL SETUP
VERY GOOD RADIATIONAL CONDITIONS...AND HAVE GONE A DEG OR TWO BELOW
LATEST GUIDANCE. NOT THINKING THERE WILL BE ANY WIDESPREAD FREEZING
TEMPERATURES INLAND...BUT THERE COULD BE SOME PATCHY TO SCATTERED
FROST WELL INLAND. THE FROST FORECAST WILL LARGELY DEPEND ON HOW
MUCH THE SURFACE TDS RECOVER OVERNIGHT. LATEST GUIDANCE...EVEN FOR
INLAND LOCATIONS...SHOWS TDS ABOVE FREEZING. GIVEN THE MARGINAL
NATURE AND UNCERTAINTY...HAVE NOT YET ADDED ANY FROST TO THE
FORECAST.
FRIDAY...MODELS ARE SHOWING A SHORTWAVE MOVING DOWN THE BACK SIDE OF
THE UPPER TROUGH OVER THE ATLANTIC IN THE MORNING...THEN IT MOVES
OFF THE MID ATLANTIC COAST WELL NORTH OF US BY AFTERNOON. THIS
FEATURE SEEMS TO REINFORCE THE SURFACE RIDGE...CENTERED OVER THE
NORTHERN AREA BY AFTERNOON. 850 MB TEMPS ARE A FEW DEGS WARMER...
THUS EXPECT MAX TEMPS TO REFLECT THIS WITH HIGHS IN THE LOWER 70S
AWAY FROM THE IMMEDIATE COAST. LIGHT NE WINDS WILL VEER TO ESE BY
LATE DAY...WHICH WILL HOLD TEMPS IN THE MID TO UPPER 60S RIGHT AT
THE SHORE.
FRIDAY NIGHT...THE SURFACE RIDGE WILL SHIFT TO ENE OF THE REGION
THROUGH THE NIGHT...WHICH WILL KEEP LOW LEVEL FLOW ESE. THIS WILL
MODERATE TEMPS...WITH LOWS GENERALLY IN THE 40S TO NEAR 50...WHICH
IS STILL BELOW NORMAL.
SATURDAY...THE MID AND UPPER LEVEL RIDGE AXIS WILL BE JUST WEST OF
THE REGION WITH THE SURFACE RIDGE CENTERED OFFSHORE. THIS WILL SETUP
A SE LOW LEVEL FLOW AND CONTINUED MODERATION OF TEMPERATURES. EXPECT
HIGHS TO BE A FEW DEGS ABOVE NORMAL...IN THE MID TO UPPER 70S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
FORECAST AGREEMENT IS PRETTY GOOD IN THE LONG TERM PERIOD. THE LARGE
UPPER RIDGE WILL STRENGTHEN ACROSS THE SOUTHEASTERN US THROUGH EARLY
NEXT WEEK. EVENTUALLY A CLOSED UPPER ANTICYCLONE WILL DEVELOP AND
SIT DIRECTLY OVER THE SOUTHEAST COAST. THE RIDGE WILL GRADUALLY
SHIFT EASTWARD THROUGH TUESDAY AND BEGIN TO GIVE WAY TO A TROF
APPROACHING FROM THE WEST FOR THE MID WEEK TIME PERIOD. THE SURFACE
HIGH WILL SETTLE OVER THE WESTERN ATLANTIC AND WILL SUPPORT A
DEVELOPING WARM SOUTHERLY RETURN FLOW INTO EARLY NEXT WEEK. WITH
HEIGHTS RISING UNDER THE RIDGE...TEMPS WILL MODERATE NICELY AND
UPPER 80S MAY EVENTUALLY COVER THE AREA FOR MONDAY AND TUESDAY. THE
FORECAST IS DRY AS IT LOOKS LIKE THE NEXT FRONT WILL NOT APPROACH
UNTIL THE WEDNESDAY TIME FRAME.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
VFR FOR THE NEXT 24 HOURS.
EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS.
&&
.MARINE...
18Z NAM AND INCOMING RUC DATA SUGGEST WINDS WILL SURGE HARDER
THAN EXPECTED OVER THE COASTAL WATERS TONIGHT AND THURSDAY MORNING
AS A SECONDARY SURGE OF COOLER AIR ADVECTS OVER THE RELATIVELY
WARMER ATLANTIC WATERS. LOOKS LIKE WINDS OF 20-25 KT WITH GUSTS TO
30 KT ARE LIKELY FOR ALL LEGS OUTSIDE OF THE CHARLESTON HARBOR.
HAVE RAISED FLAGS FOR THESE AREAS WITH VARIOUS START AND ENDING
TIMES. SEAS WILL BUILD QUICKLY IN THE FAVORABLE NORTHEAST FETCH...
BUT 6 FT SEAS WILL LINGER IN THE GEORGIA OFFSHORE LEG THROUGH
THURSDAY AFTERNOON.
MODERATE TO STRONG HIGH PRESSURE WILL BE CENTERED NORTHWEST OF THE
WATERS TO START OFF THURSDAY. THE PRESSURE GRADIENT WILL BE PINCHED
ENOUGH OVER THE SOUTHERN HALF OF THE WATERS TO SUSTAIN WINDS 15-20
KTS WITH SOME HIGHER GUSTS. RIGHT NOW...IT APPEARS THAT WINDS/SEAS
WILL REMAIN BELOW SCA LEVELS. HIGH PRESSURE WILL SETTLE OVER THE
REGION THURSDAY NIGHT THROUGH FRIDAY WITH LIGHT WINDS BECOMING
ONSHORE NEAR THE COAST DURING THE AFTERNOON. SATURDAY THROUGH
MONDAY...HIGH PRESSURE WILL BE MAINLY EAST OF THE REGION WITH SSE
LOW LEVEL FLOW OF 15 KTS OR LESS AND SEAS 4 FT OR LESS.
&&
.FIRE WEATHER...
LATEST GUIDANCE CONTINUES TO INDICATE THAT AFTERNOON MINIMUM RH
VALUES WILL BE 20-25 PERCENT OVER INTERIOR LOCATIONS FOR THURSDAY
AFTERNOON. A FIRE DANGER STATEMENT WILL BE ISSUED LATER TONIGHT
FOR MOST AREAS. LOW LEVEL MOISTURE AND TEMPERATURES GRADUALLY
INCREASE BY LATE WEEK AND THROUGH THE WEEKEND. NOT EXPECTING ANY
CRITICAL RH OR WIND ISSUES FRIDAY THROUGH THE WEEKEND.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 11 AM EDT
THURSDAY FOR AMZ352.
SMALL CRAFT ADVISORY FROM 4 AM TO 5 PM EDT THURSDAY FOR AMZ374.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM EDT
THURSDAY FOR AMZ350.
SMALL CRAFT ADVISORY FROM 4 AM TO 11 AM EDT THURSDAY FOR
AMZ354.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...RFM
LONG TERM...BSH
AVIATION...
MARINE...
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
640 PM CDT Thu Apr 12 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
Short Range (Tonight-Saturday)...
A large upper trough will continue to carve out space over the
western half of the U.S. Periodic shortwave energy will eject from
the base of the trough and combine with increasing moisture and
instability to generate several rounds of strong to severe
thunderstorms across KS/MO and areas to the southwest.
In the near term, a shortwave/vorticity max combo tracking ene
through eastern KS has generated several bands of elevated
convection. Short range convective models such as the HRRR handled
the associated convection/qpf best. Other models underplayed it
although they did a reasonably good job with the h5 vorticity
fields. Activity expected to gradually diminish as it pushes through
the upper level ridge and into drier downstream airmass.
Rest of forecast concerns center on how convective development will
be affected by the elevated mixed layer(EML) that is expected to
overspread the region tomorrow and Saturday. Lacking much of a
boundary to focus on believe this EML will prove to inhibit much of
the daytime convection on Friday and Saturday. Instead will focus on
the regeneration of the southerly low level jet over the Central
Plains both nights as the primary mechanism to initiate and maintain
nighttime convection. The first occurrence will be tonight and favor
using the 12z 4km NMM-WRF for tonights activity. An MCS is expected
to form over central/eastern NE/KS by mid evening and then roll
eastward as the low level jet veers to the southwest. The veering
allows the activity to maintain itself vs running ahead of the main
moisture source. Raised late night pops to categorical most areas.
Convection likely ongoing Friday morning but with it ending from
west to east as the EML begins to work in from the west. Conceptual
model then favors minimal if any convection so have toned down pops
for the rest of Friday/early Friday evening. Upstream redevelopment
convection may need the arrival of another shortwave and reformation
of the low level jet Friday evening. So, will again concentrate
highest pops for Friday night. Max temperatures will be tricky as
they will be greatly affected any residual cloud cover. Northeast MO
will likely be the coolest region.
Saturday should be similar to Friday in that the EML will be in
place and thus inhibit most of the convection. By Saturday a better
dryline may be in place over central KS and as a 110kt swly upper
level jet interacts with a 40kt+ southerly low level jet, expect a
squall-line of severe storms to erupt and advance eastward Saturday
evening. Severe weather could impact the western portion of the CWA
Saturday evening before it weakens. Inspection of NAM BUFR soundings
suggests that if clouds can break up many locations could challenge
the 80 degree mark.
MJ
Medium Range (Sunday through Thursday)...
Sunday...The main wave, in the form a closed upper low, associated
with the broad western CONUS trough will move into the Central
Plains. This will force a cold front into the area late in the day
on Sunday. There is much uncertainty as far as the potential for
severe weather due to ongoing showers that may be persisting across
the area in the morning and the residual cloud cover. 12Z NAM/GFS
Bufr soundings are showing only weak instability however if skies
clear, conditions could destabilize quickly with storms firing along
the cold front or along any remnant outflow boundaries from earlier
convection. This will need to be monitored further for severe
potential. Outside of the severe potential...flooding may also
become a concern over some locations as PWAT values on Sunday are
ranging from 1"-1.5". With periods of rainfall...possibly heavy in
some locations, expected Thursday night through Sunday morning and
additional heavy rain may lead to localized flooding as well as
flooding of small streams and creeks.
Monday - Thursday...We will see a pattern change as we move into the
beginning of next week. The amplified pattern that brought us
showers and thunderstorms through the weekend will become zonal
and thus tranquil. Temperatures on Monday and Tuesday will be
slightly below average with highs ranging from the mid 50s to mid
60s. Wednesday will feature a return to southerly flow out ahead of
a weak cold front. Temperatures will move to near normal with highs
in the 60s however that will be the next chance for showers across
the area as the cold front moves through the late Wednesday into
Wednesday night. By Thursday, high pressure moves back into the area
with highs moving above normal into the upper 60s to mid 70s.
73
&&
.AVIATION...
Ongoing showers look to move east of the terminals by the beginning
of the TAF period. Otherwise, expect mid level cloud cover to remain
across the area in its wake. The next round of precipitation
currently developing across central Kansas will spread east and
across the terminals around midnight. Winds will remain brisk as a tight
pressure gradient persists across the region. In addition, maintained
LLWS from the previous TAF as 50+kt LLJ veers overhead. Otherwise,
MVFR cloud cover should linger through the day Friday with perhaps
some breaks by the afternoon hours.
Deroche
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
938 AM MDT WED APR 11 2012
.UPDATE...
INCREASED 1ST PERIOD POPS NORTHERN/CENTRAL MOUNTAINS AND RIO
GRANDE VALLEY TO INCLUDE A MENTION OF ISOLATED SHOWERS AND
THUNDERSTORMS...AND ADJUSTED 1ST PERIOD SKY COVER ACCORDINGLY.
&&
.DISCUSSION...
MOISTURE IS LINGERING IN THE LOWER BOUNDARY LAYER WEST OF THE
CENTRAL MOUNTAIN CHAIN IN ADVANCE OF THE APPROACHING PACIFIC DRY
SLOT. THE 12Z KABQ SOUNDING SHOWED A PWAT OF 0.57 WHICH IS ROUGHLY
250% OF NORMAL AND IS THE HIGHEST MEASURED PWAT OVER THE PAST
COUPLE OF DAYS. LOW LEVEL MOISTURE IS ALSO INDICATED IN THE LATEST
SURFACE DEWPOINT TEMPS...WHICH ARE RUNNING AN AVERAGE 3 DEGREES
HIGHER THAN YESTERDAY AT THIS TIME. COMBINE THIS MOISTURE WITH A
LITTLE DAYTIME HEATING AND WE`LL LIKELY SEE BUILD-UPS ALONG AND
EAST OF THE DIVIDE BY LATE MORNING. DRYING IS STILL ANTICIPATED
LATER TODAY FOR THE RIO GRANDE VALLEY...BUT UNTIL THEN ISOLATED
SHOWERS AND THUNDERSTORMS ARE POSSIBLE.
ELSEWHERE...FORECAST IS ON TRACK
11
&&
.PREV DISCUSSION...256 AM MDT WED APR 11 2012...
MAIN FOCUS TODAY IS SEVERE WEATHER THREAT ACROSS THE EASTERN
PLAINS...THOUGH WINDY AND DRY CONDITIONS ARE ALSO CONCERNING ACROSS
THE WEST.
AS HAS BEEN ALLUDED TO FOR THE LAST SEVERAL DAYS...DRYLINE WILL
SHARPEN UP THIS AFTERNOON ACROSS THE PLAINS...AS DRY SOUTHWEST FLOW
ALOFT INCREASES WITH ADVANCEMENT OF UPPER LEVEL WAVE AND MIXES TO
THE SURFACE. LOOKS LIKE STORMS WILL INITIATE A BIT FURTHER WEST
THAN PREVIOUSLY ANTICIPATED...NOW SOMEWHERE ACROSS THE HIGH PLAINS.
LOCAL WRF IS FAIRLY IMPRESSIVE WITH ITS DEPICTION OF STORMS BY
21Z...WITH AT LEAST FOUR DISCRETE STORMS. HOWEVER...LATEST RUN OF
THE HRRR DEPICTS LESS ORGANIZED STORMS. NONETHELESS...SPEED AND
DIRECTIONAL SHEAR IS SUPPORTIVE OF AT LEAST A FEW DISCRETE STORMS.
OF PARTICULAR INTEREST IS THE OUTFLOW BOUNDARY FROM TEXAS PANHANDLE
STORMS THAT HAS INCHED INTO NORTHEAST NEW MEXICO. THIS CERTAINLY
MAY BE A FOCUS LATER FOR SEVERE STORMS. MAIN THREATS CONTINUE TO BE
LARGE HAIL AND DAMAGING WINDS. WOULD LIKE TO SEE DEWPOINTS EAST OF
THE DRYLINE TO BE A BIT HIGHER FOR A TORNADO THREAT...BUT AT THESE
HIGHER ELEVATIONS WITH LOW TO MID 50 DEWPOINTS...A TORNADO CAN NOT
BE RULED OUT. SEVERE WEATHER THREAT IS GREATEST EAST OF A LINE FROM
A RATON...TO SANTA ROSA...TO JUST EAST OF ROSWELL. MEANWHILE...
ONGOING STORMS ACROSS SOUTH CENTRAL PORTIONS OF THE STATE ARE MORE
RUN OF THE MILL TYPE STORMS...AND MAY ACTUALLY WEAKEN OR DIMINISH AS
SUNRISE NEARS.
AGAIN...THE OTHER STORY TODAY WILL BE THE WIND AND DRY WEATHER
ACROSS THE WEST. DRY SLOT IS ALREADY INCHING INTO WESTERN NEW
MEXICO. THOUGH THERE IS SOME VARIANCE IN THE MODELS...700 MB WINDS
LOOK TO BE AROUND 30 TO 40 KTS WITH 500 MB WINDS AROUND 60 TO 70 KTS.
SHOULD BE ABLE TO MIX SOME OF THIS MOMENTUM DOWN TO THE SURFACE THIS
AFTERNOON. THUS...WENT WITH A WIND ADVISORY FOR THE WEST/SW FOUR
ZONES.
AS THE UPPER LEVEL WAVE MOVES EAST WEDNESDAY NIGHT AND
THURSDAY...STRONG AND DRY SOUTHWEST WINDS ALOFT WILL MIX TO THE
SURFACE...AND ANY REMAINING LOW LEVEL MOISTURE WILL BE SHUNTED INTO
TEXAS. SURFACE WINDS LOOK TO BE STRONGEST ON FRIDAY...AND THE
SOUTHWEST AND SOUTH CENTRAL HIGH TERRAIN MAY CONTINUE TO SEE VERY
STRONG WIND GUSTS INTO THE OVERNIGHT HOURS FRIDAY NIGHT...AS 700 MB
WINDS INCREASE TO 50-60KTS.
AS FOR THE WEEKEND STORM SYSTEM...MODELS CONTINUE TO WAFFLE BACK AND
FORTH WITH REGARDS TO HOW IT WILL PLAY OUT. STILL LOOKS LIKE THE
INITIAL SYSTEM WILL MOVE IN ON SATURDAY...BRINGING PRECIPITATION TO
THE NORTHWEST. TEMPERATURES WILL COOL...THUS THERE COULD BE SOME
HIGH TERRAIN SNOW. AS WE GO INTO SUNDAY...ANOTHER PIECE OF ENERGY
MAY DUMBBELL AROUND AND BRING ADDITIONAL SHOWERS TO THE STATE SUNDAY
INTO MONDAY. THE ECMWF THEN BRINGS ANOTHER FAST MOVING SYSTEM ON
THIS ONES HEELS...BUT NOT SOLD ON THIS SCENARIO JUST YET.
REGARDLESS...LOOK FOR TEMPERATURES TO COOL BACK BELOW NORMAL FOR THE
WEEKEND INTO EARLY NEXT WEEK.
34
.AVIATION...
THUNDERSTORMS UNDERWAY ACROSS SOUTHERN NEW MEXICO WILL CONTINUE
THROUGH THE MORNING BEFORE EXPANDING IN COVERAGE ACROSS THE EASTERN
HALF OF THE STATE BY EARLY THIS AFTERNOON. STORMS NEAR THE TEXAS
PANHANDLE MAY PRODUCE HAIL AND DAMAGING WINDS...WITH STORMS
DECREASING AFTER 01Z THIS EVENING. EXPECT EXCURSIONS TO MVFR IN
HEAVIER SHOWERS...NEAR CAO...TCC...CVS/CVN...AND EAST OF ROW. TO THE
WEST...GUSTY SOUTHWEST WINDS TO 45 KTS NEAR THE ARIZONA WILL DEVELOP
BY MID AFTERNOON...WITH WINDS DECREASING AFTER SUNSET. SOME MVFR
CIGS DEVELOPING NEAR THE TEXAS BORDER AFTER 06Z TONIGHT FOLLOWING
THE DAYTIME CONVECTION. SOUTHWEST FLOW WILL MOVE CLOUD NORTHEAST
INTO TX AFTER 15Z THURSDAY MORNING.
NEXT AVIATION DISCUSSION SCHEDULED FOR 21Z. SHY
.FIRE WEATHER...
CRITICAL FIRE WEATHER OUTLOOK...DEVELOPING OVER WESTERN NEW MEXICO
AND THE RIO GRANDE VALLEY THIS AFTERNOON...STATEWIDE ON
THURSDAY...CENTRAL AND EASTERN NEW MEXICO ON FRIDAY AND SATURDAY.
MODELS...IN REASONABLE AGREEMENT ON BASIC STORY THROUGH THE WEEKEND
AND EARLY NEXT WORK WEEK WITH SOME MIDWEEK DIFFERENCES IN PATTERN
EVOLUTION. COHERENCE IMPROVES LATER IN THE WORK WEEK...AS MODELS
AGREE ON BROAD TIMING ON EJECTION OF UNSETTLED WEATHER. SHARP
AMPLITUDE TROUGH MOVING ONSHORE SOUTHERN CALIFORNIA THIS MORNING
WILL CARRY ADDITIONAL SHOT OF REINFORCING ENERGY PLUNGING SOUTHWEST
OUT OF THE NORTH PACIFIC. ACTION WILL SHEAR TROUGH BASE NORTH AND
EAST ACROSS THE FOUR CORNERS THIS AFTERNOON...AS NEXT BLAST FROM THE
WEST MOVES INTO SOUTHERN CALIFORNIA DURING THE DAY ON THURSDAY.
CLOSED LOW OFF THE PACIFIC NORTHWEST WILL MOVE TO SAN FRANCISCO BAY
FRIDAY...TO NORTHERN ARIZONA ON SATURDAY...AND ACROSS CENTRAL NEW
MEXICO ON SUNDAY. MODELS A LITTLE SHAKY ON ISSUING EXIT PASS FOR THE
SYSTEM...WITH GFS AND ECMWF AGREEING ON AN EJECTION TO THE NORTHERN
PLAINS AND UPPER MIDWEST BY MIDWEEK. TURBULENT NORTHWEST FLOW WILL
WORK IN OVER NEW MEXICO AS SYSTEM DEPARTS...WITH SOME DIFFERENCES IN
TIMING AND PLACEMENT OF SOME EMBEDDED SHORTWAVES. ZONAL FLOW
RETURNING OVER NEW MEXICO BY LATE THURSDAY AS THE WORK WEEK WRAPS UP.
FOR TODAY...FAST MOVING SHORTWAVE BURST ROUNDING BASE OF SOUTHERN
CALIFORNIA TROUGH WILL PUSH TOWARD THE FOUR CORNERS AND NORTHWEST
PLATEAU DURING THE DAY TODAY. COPIOUS MOMENTUM ALOFT WILL MIX TO THE
SURFACE TO PUSH WIND SPEEDS UP OVER THE WESTERN HALF OF THE STATE.
MINIMUM HUMIDITIES DROPPING TO THE LOW TEENS IN FROM THE CENTRAL
MOUNTAIN CHAIN WESTWARD TO THE ARIZONA LINE WILL PRODUCE WIDESPREAD
RED FLAG CONDITIONS...WITH LOCAL CRITICAL CONDITIONS FOR SEVERAL
HOURS THIS AFTERNOON IN THE NORTHERN AND CENTRAL MOUNTAIN CHAIN ON
THE MARGINS OF THE MAIN RED FLAG WARNING AREA. TO THE
EAST...SIGNIFICANT THUNDERSTORMS POSSIBLE ALONG THE TEXAS BORDER
WITH HAIL AND STRONG WINDS THE CHIEF THREAT. FAIR HUMIDITY
RECOVERIES OVERNIGHT...WITH GOOD RECOVERIES NEAR THE TEXAS BORDER IN
THE WAKE OF WIDESPREAD CONVECTION. NO VENTILATION ISSUES.
FOR THURSDAY...DEEPENING SURFACE TROUGH OVER EASTERN NEW MEXICO AS
SOUTHWEST FLOW ALOFT STRENGTHENS ANOTHER NOTCH DURING THE DAY.
CONVECTION AXIS WILL SHIFT EASTWARD WITH STATE LINE THUNDERSTORMS
MOVING RAPIDLY INTO TEXAS DURING THE DAY. THURSDAY WIND FOCUS
SHIFTING EAST IN TURN WITH WIDESPREAD CRITICAL FIRE WEATHER
CONDITIONS SETTING UP BROADLY ALONG AND NORTH OF INTERSTATE 40...AND
ALONG AND EAST OF INTERSTATE 25...WITH LOCALLY CRITICAL FIRE WEATHER
CONDITIONS POSSIBLE JUST ABOUT EVERYWHERE ELSE AS HUMIDITIES FALL
INTO THE TEENS STATEWIDE. COOLER AIR WILL INVADE FROM THE WEST WITH
COLD FRONT STRUNG OUT ALONG THE CENTRAL MOUNTAIN CHAIN SUMMITS BY
MID AFTERNOON THURSDAY. NO VENTILATION ISSUES...WITH FAIR HUMIDITY
RECOVERIES OVERNIGHT.
FOR FRIDAY...CLOSED LOW CENTERING TROUGH MOVING OVER SAN FRANCISCO
CIRCULATING STRONG SHORTWAVE INTO THE SOUTHERN CALIFORNIA COAST AND
MAINTAINS STRONG TURBULENT SOUTHWEST FLOW ACROSS NEW MEXICO. SURFACE
TROUGH REMAINS IN PLACE OVER EASTERN NEW MEXICO WITH ANOTHER WINDY
DAY ON TAP FOR THE CENTRAL AND EASTERN SECTIONS OF THE STATE.
HUMIDITIES IN THE LOW TEENS AND SINGLE DIGITS PCT FRIDAY AFTERNOON
WILL SET UP ANOTHER DAY OF RED FLAG CONDITIONS OVER THE EASTERN
THIRD OF THE STATE. COOLER AIR WORKING IN FROM THE WEST WILL DROP
MAXIMUM TEMPERATURES BELOW NORMAL FOR ALL BUT THE EASTERN TIER OF
THE STATE WITH SOME SHOWERS DEVELOPING NORTH AND WEST FEATURING SOME
HIGH COUNTRY SNOW BY LATE FRIDAY NIGHT. NO VENTILATION ISSUES...WITH
EXCELLENT HUMIDITY RECOVERIES NORTH AND WEST...AND CONTINUED FAIR
RECOVERIES TO THE EAST.
OUTLOOK...WEEKEND THROUGH MONDAY...COOLING TREND THROUGH THE WEEKEND
WILL START TO MINIMUM HUMIDITIES HIGHER...BUT ENOUGH DRYNESS IN
PLACE SATURDAY FOR ANOTHER AFTERNOON OF RED FLAGS FOR THE EAST.
EASTERN HUMIDITIES WILL SQUEAK ABOVE RED FLAG THRESHOLDS FOR
SUNDAY...AND BOTTOM ONLY IN THE 20S PCT FOR MONDAY TO EASE THIS
PROTRACTED ROUND OF CRITICAL FIRE WEATHER. SATURDAY WINDS WILL
REMAIN STRONG OVER THE EASTERN SLOPES AND AND ADJACENT PLAINS OF THE
CENTRAL MOUNTAIN CHAIN AND ALONG THE INTERSTATE 40 CORRIDOR AS
CLOSED LOW MOVES INTO NORTHERN ARIZONA...BUT SPEEDS WILL DROP OFF
SHARPLY SUNDAY AND MONDAY AS THE CLOSED LOW DRIFTS ACROSS NORTHERN
NEW MEXICO AND SOUTHERN COLORADO. SOME DETERIORATION IN VENTILATION
CONDITIONS OVER THE NORTH AS THE CLOSED LOW SWINGS BY...BUT
REMAINING FAVORABLE FURTHER TO THE SOUTH. SHOWER COVERAGE WITH HIGH
COUNTRY SNOW WILL SPREAD EASTWARD TO THE TEXAS BORDER THROUGH THE
WEEKEND AND WILL BE SLOW TO LEAVE WITH FAIRLY WIDESPREAD COVERAGE OF
WETTING RAINS.
SHY
&&
.PRELIMINARY POINT TEMPS/POPS UPDATE...
FARMINGTON...................... 77 40 61 32 / 0 0 0 0
DULCE........................... 73 29 59 23 / 10 5 5 5
CUBA............................ 76 34 63 28 / 5 0 0 0
GALLUP.......................... 71 31 58 26 / 0 0 0 0
EL MORRO........................ 67 29 55 23 / 0 0 0 0
GRANTS.......................... 72 33 62 27 / 0 0 0 0
QUEMADO......................... 69 35 61 30 / 0 0 0 0
GLENWOOD........................ 75 38 68 31 / 0 0 0 0
CHAMA........................... 68 34 55 27 / 20 5 5 5
LOS ALAMOS...................... 72 44 62 38 / 10 0 0 0
PECOS........................... 70 42 62 35 / 10 0 0 0
CERRO/QUESTA.................... 71 34 61 26 / 10 5 0 0
RED RIVER....................... 59 33 51 28 / 20 5 0 0
ANGEL FIRE...................... 62 29 55 27 / 20 5 0 0
TAOS............................ 72 35 62 27 / 10 0 0 0
MORA............................ 66 38 62 31 / 20 0 0 0
ESPANOLA........................ 79 35 70 31 / 10 0 0 0
SANTA FE........................ 71 43 61 37 / 10 0 0 0
SANTA FE AIRPORT................ 76 40 65 34 / 10 0 0 0
ALBUQUERQUE FOOTHILLS........... 76 46 68 41 / 10 0 0 0
ALBUQUERQUE HEIGHTS............. 78 47 69 42 / 10 0 0 0
ALBUQUERQUE VALLEY.............. 80 44 71 38 / 10 0 0 0
ALBUQUERQUE WEST MESA........... 79 44 70 39 / 10 0 0 0
LOS LUNAS....................... 81 42 72 37 / 10 0 0 0
RIO RANCHO...................... 79 44 69 39 / 10 0 0 0
SOCORRO......................... 84 45 77 40 / 10 0 0 0
SANDIA PARK/CEDAR CREST......... 77 39 66 34 / 20 0 0 0
TIJERAS......................... 77 42 68 37 / 10 0 0 0
MORIARTY/ESTANCIA............... 74 40 64 34 / 10 0 0 0
CLINES CORNERS.................. 72 40 62 34 / 20 0 0 0
GRAN QUIVIRA.................... 75 43 67 37 / 10 0 0 0
CARRIZOZO....................... 79 40 71 36 / 10 0 0 0
RUIDOSO......................... 72 43 63 38 / 20 0 0 0
CAPULIN......................... 67 43 67 37 / 50 30 0 0
RATON........................... 74 39 71 35 / 50 20 0 0
SPRINGER........................ 73 39 70 34 / 50 20 0 0
LAS VEGAS....................... 70 40 66 34 / 30 0 0 0
CLAYTON......................... 72 49 77 43 / 60 30 0 0
ROY............................. 70 46 72 39 / 50 20 0 0
CONCHAS......................... 79 49 77 42 / 50 20 0 0
SANTA ROSA...................... 79 47 76 43 / 40 10 0 0
TUCUMCARI....................... 81 54 82 47 / 60 30 0 0
CLOVIS.......................... 79 52 80 46 / 50 30 0 0
PORTALES........................ 80 52 81 45 / 50 30 0 0
FORT SUMNER..................... 85 50 85 44 / 40 20 0 0
ROSWELL......................... 86 51 85 47 / 30 10 0 0
PICACHO......................... 83 46 78 41 / 20 5 0 0
ELK............................. 77 46 72 41 / 20 5 0 0
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 8 PM MDT THIS EVENING
FOR THE FOLLOWING ZONES...NMZ101-105-106-109.
FIRE WEATHER WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY EVENING
FOR THE FOLLOWING ZONES...NMZ101>109.
FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
THE FOLLOWING ZONES...NMZ103-104-106>108.
WIND ADVISORY UNTIL 7 PM MDT THIS EVENING FOR THE FOLLOWING ZONES...
NMZ502-505-506-508.
&&
$$
11
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
256 AM MDT WED APR 11 2012
.DISCUSSION...
MAIN FOCUS TODAY IS SEVERE WEATHER THREAT ACROSS THE EASTERN
PLAINS...THOUGH WINDY AND DRY CONDITIONS ARE ALSO CONCERNING ACROSS
THE WEST.
AS HAS BEEN ALLUDED TO FOR THE LAST SEVERAL DAYS...DRYLINE WILL
SHARPEN UP THIS AFTERNOON ACROSS THE PLAINS...AS DRY SOUTHWEST FLOW
ALOFT INCREASES WITH ADVANCEMENT OF UPPER LEVEL WAVE AND MIXES TO
THE SURFACE. LOOKS LIKE STORMS WILL INITIATE A BIT FURTHER WEST
THAN PREVIOUSLY ANTICIPATED...NOW SOMEWHERE ACROSS THE HIGH PLAINS.
LOCAL WRF IS FAIRLY IMPRESSIVE WITH ITS DEPICTION OF STORMS BY
21Z...WITH AT LEAST FOUR DISCRETE STORMS. HOWEVER...LATEST RUN OF
THE HRRR DEPICTS LESS ORGANIZED STORMS. NONETHELESS...SPEED AND
DIRECTIONAL SHEAR IS SUPPORTIVE OF AT LEAST A FEW DISCRETE STORMS.
OF PARTICULAR INTEREST IS THE OUTFLOW BOUNDARY FROM TEXAS PANHANDLE
STORMS THAT HAS INCHED INTO NORTHEAST NEW MEXICO. THIS CERTAINLY
MAY BE A FOCUS LATER FOR SEVERE STORMS. MAIN THREATS CONTINUE TO BE
LARGE HAIL AND DAMAGING WINDS. WOULD LIKE TO SEE DEWPOINTS EAST OF
THE DRYLINE TO BE A BIT HIGHER FOR A TORNADO THREAT...BUT AT THESE
HIGHER ELEVATIONS WITH LOW TO MID 50 DEWPOINTS...A TORNADO CAN NOT
BE RULED OUT. SEVERE WEATHER THREAT IS GREATEST EAST OF A LINE FROM
A RATON...TO SANTA ROSA...TO JUST EAST OF ROSWELL. MEANWHILE...
ONGOING STORMS ACROSS SOUTH CENTRAL PORTIONS OF THE STATE ARE MORE
RUN OF THE MILL TYPE STORMS...AND MAY ACTUALLY WEAKEN OR DIMINISH AS
SUNRISE NEARS.
AGAIN...THE OTHER STORY TODAY WILL BE THE WIND AND DRY WEATHER
ACROSS THE WEST. DRY SLOT IS ALREADY INCHING INTO WESTERN NEW
MEXICO. THOUGH THERE IS SOME VARIANCE IN THE MODELS...700 MB WINDS
LOOK TO BE AROUND 30 TO 40 KTS WITH 500 MB WINDS AROUND 60 TO 70 KTS.
SHOULD BE ABLE TO MIX SOME OF THIS MOMENTUM DOWN TO THE SURFACE THIS
AFTERNOON. THUS...WENT WITH A WIND ADVISORY FOR THE WEST/SW FOUR
ZONES.
AS THE UPPER LEVEL WAVE MOVES EAST WEDNESDAY NIGHT AND
THURSDAY...STRONG AND DRY SOUTHWEST WINDS ALOFT WILL MIX TO THE
SURFACE...AND ANY REMAINING LOW LEVEL MOISTURE WILL BE SHUNTED INTO
TEXAS. SURFACE WINDS LOOK TO BE STRONGEST ON FRIDAY...AND THE
SOUTHWEST AND SOUTH CENTRAL HIGH TERRAIN MAY CONTINUE TO SEE VERY
STRONG WIND GUSTS INTO THE OVERNIGHT HOURS FRIDAY NIGHT...AS 700 MB
WINDS INCREASE TO 50-60KTS.
AS FOR THE WEEKEND STORM SYSTEM...MODELS CONTINUE TO WAFFLE BACK AND
FORTH WITH REGARDS TO HOW IT WILL PLAY OUT. STILL LOOKS LIKE THE
INITIAL SYSTEM WILL MOVE IN ON SATURDAY...BRINGING PRECIPITATION TO
THE NORTHWEST. TEMPERATURES WILL COOL...THUS THERE COULD BE SOME
HIGH TERRAIN SNOW. AS WE GO INTO SUNDAY...ANOTHER PIECE OF ENERGY
MAY DUMBBELL AROUND AND BRING ADDITIONAL SHOWERS TO THE STATE SUNDAY
INTO MONDAY. THE ECMWF THEN BRINGS ANOTHER FAST MOVING SYSTEM ON
THIS ONES HEELS...BUT NOT SOLD ON THIS SCENARIO JUST YET.
REGARDLESS...LOOK FOR TEMPERATURES TO COOL BACK BELOW NORMAL FOR THE
WEEKEND INTO EARLY NEXT WEEK.
34
&&
.AVIATION...
THUNDERSTORMS UNDERWAY ACROSS SOUTHERN NEW MEXICO WILL CONTINUE
THROUGH THE MORNING BEFORE EXPANDING IN COVERAGE ACROSS THE EASTERN
HALF OF THE STATE BY EARLY THIS AFTERNOON. STORMS NEAR THE TEXAS
PANHANDLE MAY PRODUCE HAIL AND DAMAGING WINDS...WITH STORMS
DECREASING AFTER 01Z THIS EVENING. EXPECT EXCURSIONS TO MVFR IN
HEAVIER SHOWERS...NEAR CAO...TCC...CVS/CVN...AND EAST OF ROW. TO THE
WEST...GUSTY SOUTHWEST WINDS TO 45 KTS NEAR THE ARIZONA WILL DEVELOP
BY MID AFTERNOON...WITH WINDS DECREASING AFTER SUNSET. SOME MVFR
CIGS DEVELOPING NEAR THE TEXAS BORDER AFTER 06Z TONIGHT FOLLOWING
THE DAYTIME CONVECTION. SOUTHWEST FLOW WILL MOVE CLOUD NORTHEAST
INTO TX AFTER 15Z THURSDAY MORNING.
NEXT AVIATION DISCUSSION SCHEDULED FOR 21Z. SHY
&&
.FIRE WEATHER...
CRITICAL FIRE WEATHER OUTLOOK...DEVELOPING OVER WESTERN NEW MEXICO
AND THE RIO GRANDE VALLEY THIS AFTERNOON...STATEWIDE ON
THURSDAY...CENTRAL AND EASTERN NEW MEXICO ON FRIDAY AND SATURDAY.
MODELS...IN REASONABLE AGREEMENT ON BASIC STORY THROUGH THE WEEKEND
AND EARLY NEXT WORK WEEK WITH SOME MIDWEEK DIFFERENCES IN PATTERN
EVOLUTION. COHERENCE IMPROVES LATER IN THE WORK WEEK...AS MODELS
AGREE ON BROAD TIMING ON EJECTION OF UNSETTLED WEATHER. SHARP
AMPLITUDE TROUGH MOVING ONSHORE SOUTHERN CALIFORNIA THIS MORNING
WILL CARRY ADDITIONAL SHOT OF REINFORCING ENERGY PLUNGING SOUTHWEST
OUT OF THE NORTH PACIFIC. ACTION WILL SHEAR TROUGH BASE NORTH AND
EAST ACROSS THE FOUR CORNERS THIS AFTERNOON...AS NEXT BLAST FROM THE
WEST MOVES INTO SOUTHERN CALIFORNIA DURING THE DAY ON THURSDAY.
CLOSED LOW OFF THE PACIFIC NORTHWEST WILL MOVE TO SAN FRANCISCO BAY
FRIDAY...TO NORTHERN ARIZONA ON SATURDAY...AND ACROSS CENTRAL NEW
MEXICO ON SUNDAY. MODELS A LITTLE SHAKY ON ISSUING EXIT PASS FOR THE
SYSTEM...WITH GFS AND ECMWF AGREEING ON AN EJECTION TO THE NORTHERN
PLAINS AND UPPER MIDWEST BY MIDWEEK. TURBULENT NORTHWEST FLOW WILL
WORK IN OVER NEW MEXICO AS SYSTEM DEPARTS...WITH SOME DIFFERENCES IN
TIMING AND PLACEMENT OF SOME EMBEDDED SHORTWAVES. ZONAL FLOW
RETURNING OVER NEW MEXICO BY LATE THURSDAY AS THE WORK WEEK WRAPS UP.
FOR TODAY...FAST MOVING SHORTWAVE BURST ROUNDING BASE OF SOUTHERN
CALIFORNIA TROUGH WILL PUSH TOWARD THE FOUR CORNERS AND NORTHWEST
PLATEAU DURING THE DAY TODAY. COPIOUS MOMENTUM ALOFT WILL MIX TO THE
SURFACE TO PUSH WIND SPEEDS UP OVER THE WESTERN HALF OF THE STATE.
MINIMUM HUMIDITIES DROPPING TO THE LOW TEENS IN FROM THE CENTRAL
MOUNTAIN CHAIN WESTWARD TO THE ARIZONA LINE WILL PRODUCE WIDESPREAD
RED FLAG CONDITIONS...WITH LOCAL CRITICAL CONDITIONS FOR SEVERAL
HOURS THIS AFTERNOON IN THE NORTHERN AND CENTRAL MOUNTAIN CHAIN ON
THE MARGINS OF THE MAIN RED FLAG WARNING AREA. TO THE
EAST...SIGNIFICANT THUNDERSTORMS POSSIBLE ALONG THE TEXAS BORDER
WITH HAIL AND STRONG WINDS THE CHIEF THREAT. FAIR HUMIDITY
RECOVERIES OVERNIGHT...WITH GOOD RECOVERIES NEAR THE TEXAS BORDER IN
THE WAKE OF WIDESPREAD CONVECTION. NO VENTILATION ISSUES.
FOR THURSDAY...DEEPENING SURFACE TROUGH OVER EASTERN NEW MEXICO AS
SOUTHWEST FLOW ALOFT STRENGTHENS ANOTHER NOTCH DURING THE DAY.
CONVECTION AXIS WILL SHIFT EASTWARD WITH STATE LINE THUNDERSTORMS
MOVING RAPIDLY INTO TEXAS DURING THE DAY. THURSDAY WIND FOCUS
SHIFTING EAST IN TURN WITH WIDESPREAD CRITICAL FIRE WEATHER
CONDITIONS SETTING UP BROADLY ALONG AND NORTH OF INTERSTATE 40...AND
ALONG AND EAST OF INTERSTATE 25...WITH LOCALLY CRITICAL FIRE WEATHER
CONDITIONS POSSIBLE JUST ABOUT EVERYWHERE ELSE AS HUMIDITIES FALL
INTO THE TEENS STATEWIDE. COOLER AIR WILL INVADE FROM THE WEST WITH
COLD FRONT STRUNG OUT ALONG THE CENTRAL MOUNTAIN CHAIN SUMMITS BY
MID AFTERNOON THURSDAY. NO VENTILATION ISSUES...WITH FAIR HUMIDITY
RECOVERIES OVERNIGHT.
FOR FRIDAY...CLOSED LOW CENTERING TROUGH MOVING OVER SAN FRANCISCO
CIRCULATING STRONG SHORTWAVE INTO THE SOUTHERN CALIFORNIA COAST AND
MAINTAINS STRONG TURBULENT SOUTHWEST FLOW ACROSS NEW MEXICO. SURFACE
TROUGH REMAINS IN PLACE OVER EASTERN NEW MEXICO WITH ANOTHER WINDY
DAY ON TAP FOR THE CENTRAL AND EASTERN SECTIONS OF THE STATE.
HUMIDITIES IN THE LOW TEENS AND SINGLE DIGITS PCT FRIDAY AFTERNOON
WILL SET UP ANOTHER DAY OF RED FLAG CONDITIONS OVER THE EASTERN
THIRD OF THE STATE. COOLER AIR WORKING IN FROM THE WEST WILL DROP
MAXIMUM TEMPERATURES BELOW NORMAL FOR ALL BUT THE EASTERN TIER OF
THE STATE WITH SOME SHOWERS DEVELOPING NORTH AND WEST FEATURING SOME
HIGH COUNTRY SNOW BY LATE FRIDAY NIGHT. NO VENTILATION ISSUES...WITH
EXCELLENT HUMIDITY RECOVERIES NORTH AND WEST...AND CONTINUED FAIR
RECOVERIES TO THE EAST.
OUTLOOK...WEEKEND THROUGH MONDAY...COOLING TREND THROUGH THE WEEKEND
WILL START TO MINIMUM HUMIDITIES HIGHER...BUT ENOUGH DRYNESS IN
PLACE SATURDAY FOR ANOTHER AFTERNOON OF RED FLAGS FOR THE EAST.
EASTERN HUMIDITIES WILL SQUEAK ABOVE RED FLAG THRESHOLDS FOR
SUNDAY...AND BOTTOM ONLY IN THE 20S PCT FOR MONDAY TO EASE THIS
PROTRACTED ROUND OF CRITICAL FIRE WEATHER. SATURDAY WINDS WILL
REMAIN STRONG OVER THE EASTERN SLOPES AND AND ADJACENT PLAINS OF THE
CENTRAL MOUNTAIN CHAIN AND ALONG THE INTERSTATE 40 CORRIDOR AS
CLOSED LOW MOVES INTO NORTHERN ARIZONA...BUT SPEEDS WILL DROP OFF
SHARPLY SUNDAY AND MONDAY AS THE CLOSED LOW DRIFTS ACROSS NORTHERN
NEW MEXICO AND SOUTHERN COLORADO. SOME DETERIORATION IN VENTILATION
CONDITIONS OVER THE NORTH AS THE CLOSED LOW SWINGS BY...BUT
REMAINING FAVORABLE FURTHER TO THE SOUTH. SHOWER COVERAGE WITH HIGH
COUNTRY SNOW WILL SPREAD EASTWARD TO THE TEXAS BORDER THROUGH THE
WEEKEND AND WILL BE SLOW TO LEAVE WITH FAIRLY WIDESPREAD COVERAGE OF
WETTING RAINS.
SHY
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 77 40 61 32 / 0 0 0 0
DULCE........................... 73 29 59 23 / 5 5 5 5
CUBA............................ 76 34 63 28 / 5 0 0 0
GALLUP.......................... 71 31 58 26 / 0 0 0 0
EL MORRO........................ 67 29 55 23 / 0 0 0 0
GRANTS.......................... 72 33 62 27 / 0 0 0 0
QUEMADO......................... 69 35 61 30 / 0 0 0 0
GLENWOOD........................ 75 38 68 31 / 0 0 0 0
CHAMA........................... 68 34 55 27 / 10 5 5 5
LOS ALAMOS...................... 72 44 62 38 / 5 0 0 0
PECOS........................... 70 42 62 35 / 10 0 0 0
CERRO/QUESTA.................... 71 34 61 26 / 10 5 0 0
RED RIVER....................... 59 33 51 28 / 20 5 0 0
ANGEL FIRE...................... 62 29 55 27 / 20 5 0 0
TAOS............................ 72 35 62 27 / 10 0 0 0
MORA............................ 66 38 62 31 / 20 0 0 0
ESPANOLA........................ 79 35 70 31 / 5 0 0 0
SANTA FE........................ 71 43 61 37 / 10 0 0 0
SANTA FE AIRPORT................ 76 40 65 34 / 5 0 0 0
ALBUQUERQUE FOOTHILLS........... 76 46 68 41 / 5 0 0 0
ALBUQUERQUE HEIGHTS............. 78 47 69 42 / 5 0 0 0
ALBUQUERQUE VALLEY.............. 80 44 71 38 / 0 0 0 0
ALBUQUERQUE WEST MESA........... 79 44 70 39 / 0 0 0 0
LOS LUNAS....................... 81 42 72 37 / 5 0 0 0
RIO RANCHO...................... 79 44 69 39 / 0 0 0 0
SOCORRO......................... 84 45 77 40 / 5 0 0 0
SANDIA PARK/CEDAR CREST......... 77 39 66 34 / 5 0 0 0
TIJERAS......................... 77 42 68 37 / 5 0 0 0
MORIARTY/ESTANCIA............... 74 40 64 34 / 10 0 0 0
CLINES CORNERS.................. 72 40 62 34 / 20 0 0 0
GRAN QUIVIRA.................... 75 43 67 37 / 10 0 0 0
CARRIZOZO....................... 79 40 71 36 / 10 0 0 0
RUIDOSO......................... 72 43 63 38 / 20 0 0 0
CAPULIN......................... 67 43 67 37 / 50 30 0 0
RATON........................... 74 39 71 35 / 50 20 0 0
SPRINGER........................ 73 39 70 34 / 50 20 0 0
LAS VEGAS....................... 70 40 66 34 / 30 0 0 0
CLAYTON......................... 72 49 77 43 / 60 30 0 0
ROY............................. 70 46 72 39 / 50 20 0 0
CONCHAS......................... 79 49 77 42 / 50 20 0 0
SANTA ROSA...................... 79 47 76 43 / 40 10 0 0
TUCUMCARI....................... 81 54 82 47 / 60 30 0 0
CLOVIS.......................... 79 52 80 46 / 50 30 0 0
PORTALES........................ 80 52 81 45 / 50 30 0 0
FORT SUMNER..................... 85 50 85 44 / 40 20 0 0
ROSWELL......................... 86 51 85 47 / 30 10 0 0
PICACHO......................... 83 46 78 41 / 20 5 0 0
ELK............................. 77 46 72 41 / 20 5 0 0
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 8 PM MDT THIS EVENING
FOR THE FOLLOWING ZONES...NMZ101-105-106-109.
FIRE WEATHER WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY EVENING
FOR THE FOLLOWING ZONES...NMZ101>109.
FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
THE FOLLOWING ZONES...NMZ103-104-106>108.
WIND ADVISORY FROM NOON TODAY TO 7 PM MDT THIS EVENING FOR THE
FOLLOWING ZONES...NMZ502-505-506-508.
&&
$$
34/SHY
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
101 PM EDT WED APR 11 2012
.SYNOPSIS...
AN UPPER LEVEL LOW OVER QUEBEC WILL MOVE SOUTH INTO THE REGION TODAY
BRINGING MORE SHOWERS AND CLOUDY SKIES TO THE NORTH COUNTRY TODAY
AND TONIGHT. THIS UPPER LOW WILL THEN MOVE OFF THE NEW ENGLAND COAST ON
THURSDAY. A RIDGE OF HIGH PRESSURE OVER THE GREAT LAKES AND OHIO
VALLEY WILL MOVE EAST INTO THE REGION THURSDAY NIGHT AND WILL REMAIN
OVER THE NORTH COUNTRY FRIDAY AND SATURDAY. A WARM FRONT WILL
APPROACH THE REGION LATE SATURDAY NIGHT AND SUNDAY...BRINGING MORE
SHOWERS TO THE REGION.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 1257 PM EDT WEDNESDAY...ELONGATED 700-500MB LOW PRESSURE
SYSTEM WILL TRANSLATE SEWD ACROSS THE NORTH COUNTRY TODAY BRINGING MOSTLY
CLOUDY CONDITIONS. SHALLOW INSTABILITY HAS DEVELOPED OWING TO COMBINATION
OF DAYTIME HEATING AND COLD POOL ALOFT. SEEING AN INCREASE IN
COVERAGE OF CELLULAR CONVECTION ON RADAR MOSAIC COMPOSITE
REFLECTIVITY...AND THIS TREND WILL CONTINUE THIS AFTN WITH
SCATTERED SHOWERS ACROSS THE NORTH COUNTRY. THIS IS CONSISTENT
WITH THE MODEL REFLECTIVITY FIELDS FROM THE LOCALLY RUN BTV-
4KMWRF AND 3KM HRRR MODEL...AND IS CONSISTENT WITH YESTERDAY/S
OBSERVED ACTIVITY. THIS MAY RESULT IN SOME GRAUPEL PRODUCTION AND
SMALL CORES OF HEAVIER RAIN SHOWERS IN A FEW SPOTS. SNOW LEVELS
GENERALLY AOA 3000 FT THIS AFTN...SO ANY SNOW SHOWER ACTIVITY WILL
BE CONFINED TO THE HIGH SUMMITS.
SFC WINDS WERE LIGHT AND VARIABLE THIS MORNING BUT WILL BECOME NLY
10-15 MPH THIS AFTN IN RESPONSE TO WEAK LOW PRESSURE DEVELOPING IN
THE GULF OF MAINE. TEMPERATURES WILL RISE SLOWLY OWING TO CLOUD
COVER...REACHING THE UPR 40S TO AROUND 50 FOR AFTN HIGHS. FORECAST
HIGH TEMPERATURES ARE A FEW DEGREES BELOW GFS MOS GUIDANCE.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/...
AS OF 445 AM EDT WEDNESDAY...THE CLOSED UPPER LOW WILL BEGIN TO
MOVE OFF THE NEW ENGLAND COAST TONIGHT...BUT WILL STILL KEEP IN A
CHANCE OF RAIN OR SNOW SHOWERS ACROSS THE REGION TONIGHT...AS THE
REGION WILL STILL BE UNDER CYCLONIC FLOW FROM THIS DEPARTING LOW.
ON THURSDAY...MODELS SHOW...ESPECIALLY THE NAM...PLENTY OF LOW
LEVEL MOISTURE LINGERING ACROSS THE REGION...AS BUFKIT FORECAST
SOUNDINGS SHOWING PLENTY OF LOW LEVEL MOISTURE IN THE 1000-700 MB
LAYER ON THURSDAY...SO WILL GO WITH MOSTLY CLOUDY SKIES. HAVE ALSO
GONE WITH SLIGHT CHANCE POPS FOR SHOWERS ACROSS EASTERN VERMONT ON
THURSDAY. HIGH PRESSURE OVER THE THE GREAT LAKES AND OHIO VALLEY
WILL SLOWLY BUILD EAST AND BRING CLEARING SKIES TO THE REGION
THURSDAY NIGHT... WITH SUNNY SKIES EXPECTED ON FRIDAY. GIVEN FULL
SUN ON FRIDAY...COULD SEE SOME VALLEY LOCATIONS APPROACH 60
DEGREES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 410 AM EDT WEDNESDAY...SFC RIDGE INTACT OVER THE NORTHEAST
FRIDAY NIGHT ON INTO THE FIRST HALF OF SATURDAY. MDLS CONTINUE TO
SHOW DIFFERENCE IN TIMING OF FRNT/LOW APPROACH. GFS IS APPEARING
TO BE MUCH TOO FAST WITH BRINGING SYSTEM THRU THE AREA...WHILE THE
LATEST ECMWF IS 6 TO 12 HRS SLOWER THAN THE LATEST GFS. BOTH MDLS
SHOW LOW MVG ALONG THE BORDER BFR FRNT ARRIVES LATE SAT/SAT NGT.
PLAN ON SPLITTING DIFFERENCE WITH THESE TWO MDLS...CLRING REGION
SLOWLY OUT TOWARDS SUNDAY EVENING. MONDAY HAS SFC HIGH PRESSURE W/
FRNT LAGGING OVER MID-ATLANTIC REGION. STRONG UPPER RIDGE SUPPORT
WITH ITS SFC COMPONENT WILL ALLOW FOR SLOW ARRIVAL OF NEXT
FRNT/LOW FOR LATE TUESDAY. WARM FRNT LOOKS TO WASH OUT AS IT
PUSHES NORTHWARD... PUTTING MAIN PRECIP EMPHASIS WITH THE CD
FRNT...WHICH WILL NOT ARRIVE TIL LATE TUESDAY ON INTO WEDNESDAY.
TEMPS OVER THE UPCOMING WEEKEND ARE DEPENDENT CLDS/PRECIP
ASSOCIATED WITH FRNT. MUCH OF SATURDAY LOOKS GD ATTM WITH SOME
CLDS AHEAD OF FRNT. 850/925 TEMPS RISE TO NEAR +8C/+10C...WHICH
WILL BRING HIGHS NEAR 60-62F FOR SATURDAY...AND 50S/L60S FOR
SUNDAY. WAA AHEAD OF FRNT FOR MON NGT/TUES WILL ALSO BRING DAYTIME
HIGHS NEAR 60F. MAINLY -RW EXPECTED DURING THE DAYTIME HRS FOR
BOTH UPCOMING SYSTEMS...BUT AT NITE WITH SOME CD AIR DRAINING IN
ON BACKSIDE...-RW WILL TRANSITION OVER TO -SW ESPECIALLY OVER HIR
TRRN.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
THROUGH 12Z THURSDAY...MAINLY MIX OF MVFR/VFR CEILINGS THRU
FORECAST PERIOD W/ BKN-OVC020-060. A FEW HRS BLW OVC010 FOR SLK IN
LGT -SW W/ VSBY 4-5SM. ALL SITES WILL SEE VCSH WITH LOW CLD COVER
LIGNERING THRU PERIOD. WINDS LGT/VAR BECM NNW 5-15KTS BY 15Z.
OUTLOOK 12Z THURSDAY THROUGH SUNDAY...12Z THURSDAY THROUGH 00Z
FRIDAY...CLOSED UPPER LOW BRINGS ADDITIONAL CLOUDS AND SHOWERS TO
THE FORECAST AREA. MAINLY VFR AT VALLEY SITES WITH A FEW PERIODS
OF MVFR IN SCATTERED SHOWERS. MOSTLY MVFR AT KSLK/KMPV WITH IFR
POSSIBLE AT KSLK IN SNOW/RAIN SHOWERS.
00Z FRIDAY THROUGH 00Z SUNDAY...PRIMARILY VFR AS A RIDGE OF HIGH
PRESSURE MOVES ACROSS THE REGION.
&&
.FIRE WEATHER...
DRY AND SUNNY CONDITIONS WILL RETURN ON FRIDAY. A RIDGE OF HIGH PRESSURE
OVER THE THE GREAT LAKES AND OHIO VALLEY WILL BUILD EAST THURSDAY NIGHT
AND REMAIN OVER THE REGION THROUGH SATURDAY...WITH DRY AND WARMER WEATHER
EXPECTED FRIDAY AND SATURDAY. MINIMUM RELATIVE HUMIDITY VALUES OF 20 TO 30
PERCENT ARE EXPECTED FRIDAY AFTERNOON AT LOWER ELEVATIONS. AT THIS
TIME...IT APPEARS WINDS WILL BE NORTH TO NORTHWEST AT 10-15 MPH
DURING THE PEAK HEATING HRS OF THE AFTN...WITH HIGH TEMPERATURES
IN THE UPPER 50S TO AROUND 60. FORECAST WINDS ARE SOMEWHAT BELOW
CRITICAL LEVELS...BUT CONDITIONS WILL CONTINUE TO BE MONITORED.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...WGH
NEAR TERM...BANACOS
SHORT TERM...WGH
LONG TERM...JN
AVIATION...JN/BOYD
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
952 AM EDT WED APR 11 2012
.SYNOPSIS...
AN UPPER LEVEL LOW OVER QUEBEC WILL MOVE SOUTH INTO THE REGION TODAY
BRINGING MORE SHOWERS AND CLOUDY SKIES TO THE NORTH COUNTRY TODAY
AND TONIGHT. THIS UPPER LOW WILL THEN MOVE OFF THE NEW ENGLAND COAST ON
THURSDAY. A RIDGE OF HIGH PRESSURE OVER THE GREAT LAKES AND OHIO
VALLEY WILL MOVE EAST INTO THE REGION THURSDAY NIGHT AND WILL REMAIN
OVER THE NORTH COUNTRY FRIDAY AND SATURDAY. A WARM FRONT WILL
APPROACH THE REGION LATE SATURDAY NIGHT AND SUNDAY...BRINGING MORE
SHOWERS TO THE REGION.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 944 AM EDT WEDNESDAY...ELONGATED 700-500MB LOW PRESSURE
SYSTEM WILL TRANSLATE SEWD ACROSS THE NORTH COUNTRY TODAY BRINGING MOSTLY
CLOUDY CONDITIONS AND A FEW LIGHT RAIN SHOWERS. BEST LOCATION FOR
PARTIAL SUNSHINE WILL BE IN THE CT RIVER VALLEY FROM WHITE RIVER
JCT SOUTHWARD. PERIODS OF RAIN (AND SNOW ABOVE 2000 FT) WILL BE
MORE FREQUENT ACROSS THE NRN ADIRONDACKS AND CENTRAL/NRN GREEN
MTNS WITH SOME UPSLOPE ENHANCEMENT. AN ADDITIONAL 1-3" OF SNOWFALL
REMAINS POSSIBLE AT THE HIGHER SUMMITS. COLD POOL ALOFT AND
DAYTIME HEATING WILL COMBINE TO CREATE WEAK INSTABILITY...AND SOME
DEVELOPMENT OF WEAK CONVECTIVE CELLS DURING THE AFTN HRS. THIS IS
SHOWN BY THE MODEL REFLECTIVITY FIELDS FROM THE LOCALLY RUN BTV-
4KMWRF AND 3KM HRRR MODEL...AND IS CONSISTENT WITH YESTERDAY/S
OBSERVED ACTIVITY. THIS MAY RESULT IN SOME GRAUPEL PRODUCTION AND
SMALL CORES OF HEAVIER RAIN SHOWERS IN A FEW SPOTS. SFC WINDS ARE
LIGHT AND VARIABLE THIS MORNING BUT WILL BECOME NLY 10-15 MPH THIS
AFTN IN RESPONSE TO WEAK LOW PRESSURE DEVELOPING IN THE GULF OF
MAINE. TEMPERATURES WILL RISE SLOWLY OWING TO CLOUD
COVER...REACHING THE UPR 40S TO AROUND 50 FOR AFTN HIGHS. FORECAST
HIGH TEMPERATURES ARE A FEW DEGREES BELOW GFS MOS GUIDANCE.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/...
AS OF 445 AM EDT WEDNESDAY...THE CLOSED UPPER LOW WILL BEGIN TO
MOVE OFF THE NEW ENGLAND COAST TONIGHT...BUT WILL STILL KEEP IN A
CHANCE OF RAIN OR SNOW SHOWERS ACROSS THE REGION TONIGHT...AS THE
REGION WILL STILL BE UNDER CYCLONIC FLOW FROM THIS DEPARTING LOW.
ON THURSDAY...MODELS SHOW...ESPECIALLY THE NAM...PLENTY OF LOW
LEVEL MOISTURE LINGERING ACROSS THE REGION...AS BUFKIT FORECAST
SOUNDINGS SHOWING PLENTY OF LOW LEVEL MOISTURE IN THE 1000-700 MB
LAYER ON THURSDAY...SO WILL GO WITH MOSTLY CLOUDY SKIES. HAVE ALSO
GONE WITH SLIGHT CHANCE POPS FOR SHOWERS ACROSS EASTERN VERMONT ON
THURSDAY. HIGH PRESSURE OVER THE THE GREAT LAKES AND OHIO VALLEY
WILL SLOWLY BUILD EAST AND BRING CLEARING SKIES TO THE REGION
THURSDAY NIGHT... WITH SUNNY SKIES EXPECTED ON FRIDAY. GIVEN FULL
SUN ON FRIDAY...COULD SEE SOME VALLEY LOCATIONS APPROACH 60
DEGREES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 410 AM EDT WEDNESDAY...SFC RIDGE INTACT OVER THE NORTHEAST
FRIDAY NIGHT ON INTO THE FIRST HALF OF SATURDAY. MDLS CONTINUE TO
SHOW DIFFERENCE IN TIMING OF FRNT/LOW APPROACH. GFS IS APPEARING
TO BE MUCH TOO FAST WITH BRINGING SYSTEM THRU THE AREA...WHILE THE
LATEST ECMWF IS 6 TO 12 HRS SLOWER THAN THE LATEST GFS. BOTH MDLS
SHOW LOW MVG ALONG THE BORDER BFR FRNT ARRIVES LATE SAT/SAT NGT.
PLAN ON SPLITTING DIFFERENCE WITH THESE TWO MDLS...CLRING REGION
SLOWLY OUT TOWARDS SUNDAY EVENING. MONDAY HAS SFC HIGH PRESSURE W/
FRNT LAGGING OVER MID-ATLANTIC REGION. STRONG UPPER RIDGE SUPPORT
WITH ITS SFC COMPONENT WILL ALLOW FOR SLOW ARRIVAL OF NEXT
FRNT/LOW FOR LATE TUESDAY. WARM FRNT LOOKS TO WASH OUT AS IT
PUSHES NORTHWARD... PUTTING MAIN PRECIP EMPHASIS WITH THE CD
FRNT...WHICH WILL NOT ARRIVE TIL LATE TUESDAY ON INTO WEDNESDAY.
TEMPS OVER THE UPCOMING WEEKEND ARE DEPENDENT CLDS/PRECIP
ASSOCIATED WITH FRNT. MUCH OF SATURDAY LOOKS GD ATTM WITH SOME
CLDS AHEAD OF FRNT. 850/925 TEMPS RISE TO NEAR +8C/+10C...WHICH
WILL BRING HIGHS NEAR 60-62F FOR SATURDAY...AND 50S/L60S FOR
SUNDAY. WAA AHEAD OF FRNT FOR MON NGT/TUES WILL ALSO BRING DAYTIME
HIGHS NEAR 60F. MAINLY -RW EXPECTED DURING THE DAYTIME HRS FOR
BOTH UPCOMING SYSTEMS...BUT AT NITE WITH SOME CD AIR DRAINING IN
ON BACKSIDE...-RW WILL TRANSITION OVER TO -SW ESPECIALLY OVER HIR
TRRN.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 12Z THURSDAY...MAINLY MIX OF MVFR/VFR CEILINGS THRU
FORECAST PERIOD W/ BKN-OVC020-060. A FEW HRS BLW OVC010 FOR SLK IN
LGT -SW W/ VSBY 4-5SM. ALL SITES WILL SEE VCSH WITH LOW CLD COVER
LIGNERING THRU PERIOD. WINDS LGT/VAR BECM NNW 5-15KTS BY 15Z.
OUTLOOK 12Z THURSDAY THROUGH SUNDAY...12Z THURSDAY THROUGH 00Z
FRIDAY...CLOSED UPPER LOW BRINGS ADDITIONAL CLOUDS AND SHOWERS TO
THE FORECAST AREA. MAINLY VFR AT VALLEY SITES WITH A FEW PERIODS
OF MVFR IN SCATTERED SHOWERS. MOSTLY MVFR AT KSLK/KMPV WITH IFR
POSSIBLE AT KSLK IN SNOW/RAIN SHOWERS.
00Z FRIDAY THROUGH 00Z SUNDAY...PRIMARILY VFR AS A RIDGE OF HIGH
PRESSURE MOVES ACROSS THE REGION.
&&
.FIRE WEATHER...
DRY AND SUNNY CONDITIONS WILL RETURN ON FRIDAY. A RIDGE OF HIGH PRESSURE
OVER THE THE GREAT LAKES AND OHIO VALLEY WILL BUILD EAST THURSDAY NIGHT
AND REMAIN OVER THE REGION THROUGH SATURDAY...WITH DRY AND WARMER WEATHER
EXPECTED FRIDAY AND SATURDAY. MINIMUM RELATIVE HUMIDITY VALUES OF 20 TO 30
PERCENT ARE EXPECTED FRIDAY AFTERNOON AT LOWER ELEVATIONS. AT THIS
TIME...IT APPEARS WINDS WILL BE NORTH TO NORTHWEST AT 10-15 MPH
DURING THE PEAK HEATING HRS OF THE AFTN...WITH HIGH TEMPERATURES
IN THE UPPER 50S TO AROUND 60. FORECAST WINDS ARE SOMEWHAT BELOW
CRITICAL LEVELS...BUT CONDITIONS WILL CONTINUE TO BE MONITORED.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...WGH
NEAR TERM...BANACOS
SHORT TERM...WGH
LONG TERM...JN
AVIATION...JN/BOYD
FIRE WEATHER...BANACOS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
145 AM EDT WED APR 11 2012
.SYNOPSIS...
A NOTICEABLE COOLING TREND WILL PREVAIL WEDNESDAY AND THURSDAY AS
HIGH PRESSURE DROPS CANADIAN AIR INTO THE REGION. PATCHY FROST IS
POSSIBLE EARLY THURSDAY AND FRIDAY MORNINGS. A WARMING TREND CAN
THEN BE EXPECTED OVER THE WEEKEND AND THROUGH EARLY NEXT WEEK...AS
AN UPPER RIDGE BUILDS OVER THE CAROLINAS. SIGNIFICANT RAINFALL IS
NOT EXPECTED THROUGH NEXT TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM TUESDAY...HIGH-BASED CONVECTION IN THE FLORENCE AREA
PRODUCED SOME DAMAGING WIND GUSTS AT THE SURFACE AROUND SUNSET. WE
RECEIVED SEVERAL REPORTS FROM MEDIA AND WEATHER SPOTTERS FROM
TIMMONSVILLE INTO FLORENCE OF 50-55 MPH WINDS...TREES DOWN AND EVEN
DAMAGE TO A BARN. ELSEWHERE IT APPEARS WINDS REMAINED UNDER 40 MPH.
THE CULPRIT IN THIS CASE WAS EVAPORATIONAL COOLING OF RAIN IN THE
DEEP DRY LAYER UNDER THE CLOUD BASE. THIS CREATED NEGATIVELY BUOYANT
(HEAVY AND COLD) AIR THAT ACCELERATED DOWNWARD UNTIL IT HIT THE
GROUND AND SPREAD OUT HORIZONTALLY. THE 20-21Z HRRR MODEL RUNS
STRUGGLED WITH THEIR DEPICTION OF RAINFALL...BUT THE 23Z RUN LOOKS
REASONABLE AND SHOWS A LINE OF SHOWERS EXTENDING FROM MARION AND
NORTHERN HORRY COUNTY INTO WILMINGTON THROUGH 04Z/MIDNIGHT...THEN
DISSIPATING BY 06Z. OTHERWISE...NO SIGNIFICANT CHANGES HAVE BEEN
MADE TO THE FORECAST. PREVIOUS DISCUSSION FROM 7 PM FOLLOWS...
IN A WEATHER PATTERN MORE REMINISCENT OF JANUARY THAN APRIL WE HAVE
A LARGE UPPER LOW OVER SOUTHERN QUEBEC AND A STRONG VORTICITY
MAXIMUM ROTATING EASTWARD AROUND THE SOUTHERN PERIPHERY OF THE LOW.
THIS VORT MAX WILL HELP DRIVE A SURFACE COLD FRONT THROUGH THE
EASTERN CAROLINAS BY MIDNIGHT...USHERING IN A VERY COLD AIRMASS FOR
THIS TIME OF YEAR. DEEP VERTICAL MIXING (UP TO 10000 FT ACCORDING TO
THE 18Z NAM) HAS MADE EFFICIENT USE OF WHAT LITTLE MOISTURE EXISTED
THIS AFTERNOON AND HAS ACTUALLY PRODUCED HIGH-BASED CONVECTION WITH
CUMULONIMBUS BASES NEARLY TWO MILES UP. RADAR COMPOSITES SHOW THIS
SHOWER ACTIVITY WILL MOVE INTO EASTERN SC AND PORTIONS OF
SOUTHEASTERN NC THIS EVENING...ALTHOUGH WITH RAINFALL TOTALS
REMAINING ONLY A FEW HUNDREDTHS OF AN INCH AT BEST. FORECAST POPS
RANGE FROM 40-50 PERCENT IN THE FLORENCE AREA TO ONLY 10 PERCENT IN
GEORGETOWN. MOST OF SOUTHEASTERN NC STANDS ABOUT A 20 PERCENT CHANCE
OF MEASURABLE RAIN (0.01 INCH OR GREATER) THIS EVENING.
CLOUDS SHOULD CLEAR OFF THE COAST SHORTLY AFTER MIDNIGHT WITH COLD
ADVECTION INCREASING LATE BEHIND THE SURFACE COLD FRONT. 1000-500 MB
THICKNESS VALUES WILL PLUMMET TO AROUND 540 DM BY DAYBREAK WEDNESDAY
IN THE LUMBERTON VICINITY. LARGE HEAT FLUXES OUT OF THE SOIL PLUS
THE SHORT LENGTH OF NIGHT IN APRIL WILL HELP SPARE US FROM COLD
TEMPERATURES TONIGHT...BUT WE`LL BE WATCHING WEDNESDAY NIGHT CLOSELY
AS WINDS DIE DOWN.
NO CHANGES HAVE BEEN MADE TO FORECAST LOWS...STILL EXPECTED TO RANGE
FROM 43-47 INLAND AND 46-50 AT THE COAST.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 200 PM TUESDAY...THE LEADING EDGE OF A COOL CANADIAN BLAST
IS POISED TO OVERSPREAD THE REGION AS AN AMPLIFIED UPPER TROUGH
PRESENTLY DIGGING OVER THE OHIO VALLEY PIVOTS ACROSS THE REGION
AND HELPS USHERS CHILLED HIGH PRESSURE THROUGH THE CAROLINAS.
BY DAYBREAK WEDNESDAY A COLD FRONT OFFSHORE WILL BE PUSHING
FARTHER TO SEA...USHERING DEEP AND DRY NW FLOW ACROSS THE AREA.
AS THE BASE OF THE COOL POOL ALOFT CROSSES OUR ZONES WEDNESDAY
AFTERNOON...SUSPECT SOME CUMULUS DEVELOPMENT WILL BE GENERATED.
DRYNESS ALOFT WILL GREATLY SQUELCH THE DEPTH OF CONVECTION AND
NO MENTIONABLE POP VALUES ARE PLANNED AS THE TROUGH AXIS CROSSES.
SURFACE DEWPOINTS AND RADIATIVE POTENTIAL EARLY THURSDAY AND FRI
MORNING SUPPORT INCLUSION OF PATCHY FROST IN THE GRIDS. BOTH MAY
BE EQUALLY COLD WITH LIGHTER WINDS LATE THURSDAY NIGHT. WIDESPREAD
30S EXPECTED BOTH MORNINGS...WITH POCKETS OF INLAND FREEZING TEMPS
A POSSIBILITY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 200 PM TUESDAY...A NICE WARM UP WILL COMMENCE THIS WEEKEND...
FOLLOWING A COOL FRIDAY. THE H5 PATTERN WILL CHANGE FROM A TROUGH
IN THE EAST TO A BUILDING RIDGE INTO NEXT WEEK. AT THE SURFACE...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH FRIDAY...THEN SHIFT OFF
THE COAST RESULTING IN RETURN FLOW DEVELOPING DURING THE WEEKEND.
WARM AIR ADVECTION WILL ALLOW TEMPS TO REACH CLIMO SATURDAY THEN
WARM A COUPLE CATEGORIES ABOVE CLIMO BY EARLY NEXT WEEK. THE
DEVELOPING MID/UPPER RIDGE WILL KEEP A LID ON ANY MEANINGFUL
CHANCE OF RAIN THROUGH MUCH OF THE PERIOD.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...COLD FRONT WILL BE DROPPING ACROSS THE FORECAST AREA AND
OFF THE COAST BY 08Z. ISOLATED PRECIPITATION ACCOMPANIED BY THUNDER
WILL MAINLY AFFECT THE ILM TERMINAL UNTIL THE CFP.
WINDS AFTER FROPA WILL BECOME A NUISANCE TO AVIATORS...ESPECIALLY
WHEN THE GUSTS COMMENCE. EXPECT POST FRONTAL NORTHWEST WINDS
THROUGH DAYBREAK...BECOMING GUSTY IN THE 15 TO 25 KT RANGE SEVERAL
HRS AFTER DAYBREAK. THIS IN RESPONSE TO A TIGHTENED SFC PG COMBINED
WITH EXCELLENT CAA FOR THIS TIME OF THE YEAR. MODEL TIME HEIGHT
SERIES INDICATE A SLUG OF MOISTURE AROUND 5K FT THIS AFTERNOON. AS A
RESULT...WILL PLACE A SCATTERED SC/CU CLOUD DECK IN. WINDS AND
ESPECIALLY THE GUSTINESS...WILL DIMINISH TOWARD SUNSET. ENOUGH OF A
SFC PG THIS EVENING TO KEEP NW-NNW WINDS ACTIVE THROUGH 06Z.
EXTENDED OUTLOOK...EXPECT VFR THROUGH FRIDAY. POSSIBLE MORNING FOG
SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM TUESDAY...UPDATES LATE THIS EVENING ARE MAINLY TO SEAS
WHICH ARE RUNNING ABOUT A FOOT LARGER THAN WERE PREVIOUSLY
FORECAST...ESPECIALLY IN THE CAPE FEAR VICINITY. OTHERWISE NO
SIGNIFICANT CHANGES HAVE BEEN MADE. PREVIOUS DISCUSSION FROM 7 PM
FOLLOWS...
IN A PATTERN MORE REMINISCENT OF JANUARY THAN APRIL...A STRONG COLD
FRONT CURRENTLY IN THE WESTERN PIEDMONT OF THE CAROLINAS WILL WHIP
EAST AND OFFSHORE AROUND MIDNIGHT. THE PRESSURE GRADIENT HAS BEEN
TIGHTENING ALL DAY IN ADVANCE OF THIS FRONT AND WE ARE EXPECTING A
PERIOD OF 20-25 KT WINDS TO OCCUR THIS EVENING INTO EARLY WEDNESDAY
MORNING ACROSS THE NORTH CAROLINA COASTAL WATERS. ACROSS THE SOUTH
CAROLINA WATERS THE SYNOPTIC WINDS SHOULD REMAIN IN THE 15-20 KT
RANGE...HOWEVER OBSERVATIONS SHOW THE SEABREEZE ENHANCEMENT IN THE
MYRTLE BEACH AREA HAS PUSHED GUSTS TO NEAR 25 KNOTS. THESE STRONGER
SEABREEZE-ENHANCED WINDS SHOULD DIE AWAY THIS EVENING. SOUTHWEST
WINDS WILL TURN WESTERLY LATE THIS EVENING...THEN NORTHWEST LATE
TONIGHT BEHIND THE FRONT AS IT PUSHES OFFSHORE.
RADAR SHOWS PATCHES OF MAINLY LIGHT SHOWERS ACROSS CENTRAL SOUTH
CAROLINA JUST AHEAD OF THE FRONT. SPRINKLES OR PERHAPS AN ISOLATED
LIGHT SHOWERS MAY MAKE IT TO THE COAST IN THE NEXT FEW HOURS.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 200 PM TUESDAY...BRISK NW WINDS WILL PREVAIL MUCH OF THIS
PERIOD AS A DRY BUT STRONG COLD FRONT MOVES SE OVER THE WATERS
LATE TONIGHT INTO EARLY WEDNESDAY. CAUTIONARY STATEMENTS MAY BE
NEEDED FOR A PORTION OF WEDNESDAY FOR GUSTY NW WINDS BEHIND THE
DEPARTING COLD FRONT. ANOTHER SURGE OF COLD AIR EXPECTED EARLY
THURSDAY MORNING REINFORCED BY CHILLY HIGH PRESSURE...BUT DOESNT
APPEAR AS STRONG. SEAS WILL REMAIN BUMPY OFFSHORE BUT SUPPRESSED
INSHORE IN THE NW WIND TRAJECTORY. NO TSTMS EXPECTED INSHORE BUT
CLOUD TO WATER LIGHTNING STRIKES AND STRONG CONVECTION MAY FIRE
OVER THE GULF STREAM LATE TONIGHT AND EARLY WEDNESDAY.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 200 PM TUESDAY...HIGH PRESSURE WILL RIDGE IN FROM THE NORTH
FRIDAY...THEN SHIFTS OFF THE COAST BY THIS WEEKEND. AS THE HIGH
MOVES BY THE FLOW WILL TURN FROM A NORTHERLY DIRECTION EARLY ON IN
THE PERIOD TO A SOUTHERLY DIRECTION DURING THE WEEKEND. SPEEDS
WILL BE MODULATED BY A RESULTANT SEA BREEZE SAT AND SUN. OVERALL
SPEEDS WILL BE LESS THAN 15 KNOTS THROUGH THE PERIOD...WITH THE
LIGHTEST WINDS ON FRIDAY. SEAS WILL BE MINIMAL ON FRIDAY...THEN
BECOME CHOPPY DURING THE WEEKEND AS A SOUTHERLY LOWER PERIOD WAVE
BECOMES ESTABLISHED.
$$
.FIRE WEATHER...
AS OF 200 PM TUESDAY...TODAYS RED FLAG WARNING WILL PLAY OUT THROUGH
800 PM ACROSS OUR VERY NORTHERN TIER...WHERE WE CURRENTLY SEE THE
STRONGER WIND GUSTS AND RH VALUES GENERALLY AROUND 20 PERCENT.
POST FRONTAL DRYING/LOWERING DEWPOINTS WEDNESDAY ACCOMPANIED BY
GUSTY NW WINDS...WILL AGAIN LEAD TO AN ELEVATED FIRE SPREAD
POTENTIAL AND A AN SPS-BASED "FIRE DANGER STATEMENT" WILL BE ISSUED
TO ADDRESS THE AGGRAVATED CONDITIONS EXPECTED WEDNESDAY AFTERNOON.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR SCZ017-024.
NC...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR NCZ087-096-
105-106.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 6 AM EDT
WEDNESDAY FOR AMZ250-252.
&&
$$
NEAR TERM...TRA
SHORT TERM...MJC
LONG TERM...III
AVIATION...DCH/HDL43
FIRE WEATHER...MJC
AREA FORECAST DISCUSSION
NWS PORTLAND OR
850 AM PDT WED APR 11 2012
.SYNOPSIS...SHOWERY WEATHER WILL CONTINUE THROUGHOUT THE WEEK AS ONE
UPPER LEVEL LOW PRESSURE SYSTEM IS REPLACED BY ANOTHER OFF THE
NORTHERN CALIFORNIA AND OREGON COAST. MODEST INSTABILITY MAY BE
ENOUGH FOR ISOLATED THUNDERSTORMS AT TIMES...MAINLY DURING THE
AFTERNOON AND EARLY EVENING OF TODAY AND THURSDAY AS WEAK
DISTURBANCES LIFT THROUGH THE REGION. THERE WILL ALSO BE BREAKS IN
SHOWER ACTIVITY BETWEEN DISTURBANCES. TEMPERATURES WILL GRADUALLY
BECOME COOLER WITH SNOW LEVELS DIPPING TO SOME OF THE CASCADE PASSES
BY THURSDAY MORNING.
&&
.SHORT TERM...SATELLITE IMAGERY SHOWS THE UPPER TROUGH THAT STALLED
OFFSHORE THE PAST SEVERAL DAYS HAS PUSHED INLAND...SPREADING LIGHT
RAIN ACROSS THE REGION. A SHORTWAVE WILL MOVE OVER THE AREA LATE THIS
AFTERNOON AS COOLER AIR ALOFT MOVES IN...AND THE ATMOSPHERE WILL
BECOME MORE UNSTABLE. MODELS INDICATE ENOUGH INSTABILITY TO POSSIBLY
TRIGGER A FEW THUNDERSTORMS...BUT THINK CLOUD COVER MAY LIMIT
DAYTIME HEATING AND A SURFACE SOURCE FOR UPLIFT.
THE NEXT TROUGH IS RIGHT ON THE HEALS OF THE CURRENT SYSTEM AND IS
ELONGATING INTO A NEGATIVELY TILTED TROUGH AS IT NEARS THE
PACIFIC NW...WITH MULTIPLE WAVES EMBEDDED WITHIN THE TROUGH. THIS
TROUGH WILL HAVE A COLD POOL OF AIR ASSOCIATED WITH IT WITH GFS
FORECASTING -13C 700 MB TEMPERATURES ACROSS NW OREGON THURSDAY. SNOW
LEVELS WILL LOWER TO NEAR OR JUST BELOW PASS LEVEL THURSDAY AND
FRIDAY AS THE TROUGH PUSHES INLAND....BUT FAIRLY LIGHT QPF IS
EXPECTED. MODELS FORECAST GREATER MID-LEVEL INSTABILITY WITH THIS
FEATURE AND THERE IS ANOTHER CHANCE FOR THUNDERSTORMS THURSDAY
AFTERNOON. THE LOW AND COLD AIR ALOFT SAGS SOUTH OF THE AREA ON
FRIDAY AND SHOWERS WILL DECREASE.
.LONG TERM...NO CHANGES...PREVIOUS DISCUSSION FOLLOWS...BY THE END OF
THE WEEK...WE WILL BEGIN TO TRANSITION TOWARD ANOTHER DRY PERIOD. AS
AN UPPER LEVEL TROUGH OVER THE PAC NW PUSHES EAST OF THE
REGION...RIDGING WILL BEGIN TO BUILD IN ITS WAKE. SOME LIGHT SHOWERS
WILL REMAIN A POSSIBILITY FRI NIGHT INTO EARLY SAT BEFORE THE RIDGING
CAN BECOME WELL ESTABLISHED OVER THE WEEKEND. SAT AND SUN LOOK DRY
WITH TEMPS NEAR OR SLIGHTLY ABOVE AVERAGE. BY MON...THE RIDGE AXIS IS
BEGINNING TO PUSH EAST OF THE CASCADES ANOTHER PERIOD OF UNSETTLED
WEATHER LOOKING LIKELY NEXT WEEK. THE EXTENDED MODELS ARE FAIRLY
CONSISTENT IN SPREADING WARM FRONTAL RAIN ONTO THE COAST LATE
MON...WITH RAIN SPREADING INLAND TUE AS THE FRONTAL SYSTEM PUSHES
ONSHORE. JFP
&&
.AVIATION...SOUTH FLOW ALOFT BRINGING LOTS OF MOISTURE ALOFT OVER
THE AREA TODAY WITH A SHARP TROUGH OFF THE WEST COAST. VERY WEAK
NW FLOW NEAR THE SURFACE. MOIST AIR MASS IS RESULTING IN HIGHLY
VARIABLE CIG AND VIS CONDITIONS THIS MORNING WITH IFR CIGS IN SOME
OF THE HEAVIER RAIN AREAS AND VFR CONDITIONS ELSEWHERE. EXPECT
CONDITIONS TO BE MOSTLY VFR AFT 19Z WITH THE STRATIFORM RAIN
TURNING MORE SHOWERY. NAM AND HRRR MODELS SHOWS A WEAK SHORT WAVE
MOVING ACROSS AREA FROM THE SOUTH DURING THE AFTERNOON WHICH COULD
HELP SET OFF SOME SHOWERS AND POSSIBLE THUNDERSTORMS. THE AIR
MASS IS NOT THAT UNSTABLE BUT WITH ALL THE MOISTURE AROUND IT MAY
NOT TAKE MUCH TO RESULT IN SOME CONVECTION. EXPECT ANY
THUNDERSTORMS THAT FORM TO BE ISOLATED WITH MVFR CIGS ASSOCIATED
WITH THEM. TOPS OF ANY CONVECTION THAT FORMS THROUGH EARLY EVENING
COULD BE AROUND 25K FT. SCHNEIDER
KPDX AND APPROACHES...EXPECT CONTINUED VARIABILITY FOR CIGS DURING
MORNING ARRIVALS. PLAN ON PREVAILING CIGS AROUND AROUND 2500 FT
BUT COULD BE LOWER TO AROUND 1100 FEET ON THE APPROACHES. CONDITIONS
SHOULD GRADUALLY IMPROVE THROUGH THE MORNING WITH A RETURN TO
PREVAILING MVFR OR BETTER BY AFTERNOON. THERE IS A SLIGHT CHANCE
FOR CONVECTION AFTER 21Z. SCHNEIDER
&&
.MARINE...LIGHT SOUTH WINDS WILL CONTINUE THIS MORNING. MORNING
MODELS ARE A LITTLE WEAKER WITH THE SHORTWAVE AND SURFACE TROUGH
THAT MOVES ACROSS THE WATERS TONIGHT AND TOMORROW. STILL EXPECT
SOLID SMALL CRAFT CONDITIONS LATER THIS EVENING. LESS OF A THREAT
OF GALES AT THIS TIME SO WILL CONTINUE THE SMALL CRAFT ADVISORY
THAT IS OUT. GWW, ENP, AND LOCALLY RUN SWAN ALL CONTINUE TO
INDICATE RATHER SQUARE WAVES REACHING THE COAST FRIDAY NIGHT AND
FOR PORTIONS OF SATURDAY. THESE ARE SOURCED FROM THE NEXT
APPROACHING UPPER LOW OFF THE ALEUTIAN CHAIN AND CURRENTLY BELIEVE
MODELS ARE NOT DECAYING THE TRAIN QUITE FAST ENOUGH, BUT WILL KEEP
WATCHING FOR OBSERVATIONS FROM THE OPEN SEAS TO CONFIRM. SCHNEIDER
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 5 PM THIS AFTERNOON TO 5 PM
PDT THURSDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
FLORENCE OR OUT 60 NM.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1030 PM CDT THU APR 12 2012
.DISCUSSION.../ISSUED AT 835 PM CDT/
SHOWERS DECREASED ACROSS THE AREA EARLY THIS EVENING AND NOW
BEGINNING TO INCREASE AGAIN WEST OF I29 AS SHORT WAVE LIFTS
NORTHEAST OUT OF COLORADO. HRRR MODEL SEEMS TO HAVE THIS PEGGED
QUITE WELL WITH COVERAGE BECOMING FAIRLY WIDESPREAD AFTER MIDNIGHT.
SO WILL CONTINUE TREND WITH INCREASING POPS DURING THE NIGHT.
TEMPERATURES WILL NOT FALL MUCH IF AT ALL THE REST OF THE NIGHT WITH
THE CLOUDS AND INCREASING DEW POINTS. CURRENT FORECAST LOOKS GOOD
WITH ONLY SOME MINOR TWEAKS WITH THE TEMPERATURES TONIGHT.
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE TO SPREAD ACROSS THE
REGION THROUGH THE NIGHT WITH LOWERING CEILINGS AT THE ONSET OF
PRECIPITATION. WHILE VISIBILITIES WILL GENERALLY REMAIN IN THE VFR
RANGE...CANNOT RULE OUT LOWER VISIBILITY IN HEAVIER
SHOWER/THUNDERSTORM ACTIVITY. STEADIER RAIN SHOULD DIMINISH BETWEEN
12Z AND 15Z ON FRIDAY.
&&
.PREVIOUS DISCUSSION.../ISSUED AT 400 PM CDT/
THE BAND OF SHOWERS CURRENTLY SHIFTING NORTHEAST THROUGH THE EASTERN
HALF OF THE FORECAST AREA APPEARS TO BE TIED TO A BAND OF ELEVATED
FRONTOGENESIS AND A NARROW VORTICITY MAXIMUM CURRENTLY SHIFTING INTO
PORTIONS OF SOUTHWEST MINNESOTA AND NORTHWEST IOWA. A FEW VERY
ISOLATED SHOWERS MAY BE POSSIBLE BEHIND THIS LINE WITH INCREASING
MOISTURE ADVECTION AND THE DEVELOPMENT OF A LOW LEVEL JET...BUT
EXPECT MOST ACCUMULATING PRECIPITATION ASSOCIATED WITH THE CURRENT
BAND TO PUSH OFF TO THE NORTHEAST AND OUT OF THE FORECAST AREA BY
AROUND 00Z THIS EVENING. A SECOND AREA OF SHOWERS AND THUNDERSTORMS
SHOULD DEVELOP IN NORTH CENTRAL NEBRASKA AND SOUTH CENTRAL SOUTH
DAKOTA AS THE LOW LEVEL JET INCREASES IN EARNEST AFTER 00Z...AND
WILL SHIFT EASTWARD DURING THE NIGHT. PRECIPITATION WILL LINGER INTO
THE MORNING HOURS ON FRIDAY...BEFORE THE SYSTEM IS EJECTED EASTWARD
BY A STRENGTHENING JET ACROSS THE CENTRAL PLAINS. /LAFLIN
A MID LEVEL WAVE EXPECTED TO TRACK NORTHEAST THROUGH THE FORECAST
AREA DURING THE DAY ON FRIDAY AS THE LARGELY UNSETTLED WEATHER
PATTERN PERSISTS ACROSS THE CENTRAL STATES. SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO TRACK EASTWARD THROUGH THE FORECAST
AREA IN THE MORNING AS THE MID LEVEL WAVE KICKS THROUGH THEN TAPER
OFF IN THE AFTERNOON BEHIND THE WAVE. DECENT MIXING POTENTIAL
PARTICULARLY ACROSS THE WEST WILL ALLOW TEMPERATURES TO CLIMB INTO
60S WITH SOME LOWER 70S POSSIBLE. WEAK RIDGING NOSES INTO THE
CENTRAL PLAINS ON FRIDAY NIGHT IN THE WAKE OF THE PASSING SHORTWAVE
TROUGH. FLOW WILL TURN MORE SOUTHERLY OVERNIGHT WHICH WILL SET UP A
STRONG PUSH OF WARM AIR ADVECTION. THIS ALONG WITH INCREASING CLOUDS
LATE AT NIGHT WILL KEEP LOWS FROM FALLING BELOW THE MID 40S TO LOWER
50S.
THE NEXT DISTURBANCE IS EXPECTED TO TRACK INTO THE REGION ON
SATURDAY. MUCAPE AS HIGH AS 2500 J/KG...EFFECTIVE SHEAR OF 60 KT
WITH INCREASED MID LEVEL WINDS AND STEEP LOW LEVEL LAPSE RATES WILL
BE FOCUSED ACROSS NORTHWEST IOWA AS A WARM FRONT TRACKING
NORTHEASTWARD INTO THE OVERNIGHT HOURS. COULD SEE SOME SEVERE
THUNDERSTORM DEVELOPMENT IN THIS WEAKLY CAPPED AREA SATURDAY EVENING
INTO THE EARLY MORNING HOURS WHILE A MORE GENERAL CHANCE OF SHOWERS
AND THUNDERSTORMS ARE EXPECTED ELSEWHERE.
YET ANOTHER ROUND OF WET WEATHER RETURNS FOR SUNDAY THROUGH MONDAY
AS THE MAIN CLOSED LOW CIRCULATION FINALLY EJECTS OUT OF THE
SOUTHWESTERN STATES AND SWINGS NORTHEAST ACROSS THE CENTRAL AND
SOUTHERN PLAINS THEN INTO THE GREAT LAKES BY MONDAY AFTERNOON.
PRETTY SIGNIFICANT PRECIPITATION CHANCES ARE EXPECTED DURING THIS
PERIOD WHICH WILL BE MOST NOTABLE FOR THE MUCH COLDER POOL OF AIR
EXPECTED TO ADVECT INTO THE AREA BEHIND THE TROUGH. WHILE
PRECIPITATION WILL INITIALLY BE RAINFALL SUNDAY AND SUNDAY
EVENING...TEMPERATURES ARE EXPECTED TO FALL TO NEAR OR SLIGHTLY
BELOW FREEZING LATE SUNDAY NIGHT WITH HIGHS ON MONDAY LIKELY TO ONLY
REACH THE 40S. AT THIS POINT...EXPECT RAIN TO MIX WITH SNOW LATE
SUNDAY NIGHT/MONDAY MORNING AND POSSIBLY TRANSITION TO MAINLY SNOW
ACROSS THE NORTHWESTERN THIRD OF THE CWA.
BEHIND THIS SYSTEM...WEAK NORTHWEST FLOW SETTLES IN FOR TUESDAY AND
WEDNESDAY. MODELS HINT AT A FEW POTENTIAL WEAK WAVES MOVING THROUGH
THE NORTHERN PLAINS WITH THIS FLOW...HOWEVER THE MODELS DO NOT SHOW
MUCH AGREEMENT IN THE STRENGTH AND TIMING OF THESE FEATURES. IT DOES
LOOK LIKE A GRADUAL WARMING TREND DURING THIS PERIOD WITH
TEMPERATURES RETURNING TO NEAR OR ABOVE NORMAL.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
835 PM CDT THU APR 12 2012
.DISCUSSION.../ISSUED AT 835 PM CDT/
SHOWERS DECREASED ACROSS THE AREA EARLY THIS EVENING AND NOW
BEGINNING TO INCREASE AGAIN WEST OF I29 AS SHORT WAVE LIFTS
NORTHEAST OUT OF COLORADO. HRRR MODEL SEEMS TO HAVE THIS PEGGED
QUITE WELL WITH COVERAGE BECOMING FAIRLY WIDESPREAD AFTER MIDNIGHT.
SO WILL CONTINUE TREND WITH INCREASING POPS DURING THE NIGHT.
TEMPERATURES WILL NOT FALL MUCH IF AT ALL THE REST OF THE NIGHT WITH
THE CLOUDS AND INCREASING DEW POINTS. CURRENT FORECAST LOOKS GOOD
WITH ONLY SOME MINOR TWEAKS WITH THE TEMPERATURES TONIGHT.
&&
.PREVIOUS DISCUSSION.../ISSUED AT 400 PM CDT/
THE BAND OF SHOWERS CURRENTLY SHIFTING NORTHEAST THROUGH THE EASTERN
HALF OF THE FORECAST AREA APPEARS TO BE TIED TO A BAND OF ELEVATED
FRONTOGENESIS AND A NARROW VORTICITY MAXIMUM CURRENTLY SHIFTING INTO
PORTIONS OF SOUTHWEST MINNESOTA AND NORTHWEST IOWA. A FEW VERY
ISOLATED SHOWERS MAY BE POSSIBLE BEHIND THIS LINE WITH INCREASING
MOISTURE ADVECTION AND THE DEVELOPMENT OF A LOW LEVEL JET...BUT
EXPECT MOST ACCUMULATING PRECIPITATION ASSOCIATED WITH THE CURRENT
BAND TO PUSH OFF TO THE NORTHEAST AND OUT OF THE FORECAST AREA BY
AROUND 00Z THIS EVENING. A SECOND AREA OF SHOWERS AND THUNDERSTORMS
SHOULD DEVELOP IN NORTH CENTRAL NEBRASKA AND SOUTH CENTRAL SOUTH
DAKOTA AS THE LOW LEVEL JET INCREASES IN EARNEST AFTER 00Z...AND
WILL SHIFT EASTWARD DURING THE NIGHT. PRECIPITATION WILL LINGER INTO
THE MORNING HOURS ON FRIDAY...BEFORE THE SYSTEM IS EJECTED EASTWARD
BY A STRENGTHENING JET ACROSS THE CENTRAL PLAINS. /LAFLIN
A MID LEVEL WAVE EXPECTED TO TRACK NORTHEAST THROUGH THE FORECAST
AREA DURING THE DAY ON FRIDAY AS THE LARGELY UNSETTLED WEATHER
PATTERN PERSISTS ACROSS THE CENTRAL STATES. SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO TRACK EASTWARD THROUGH THE FORECAST
AREA IN THE MORNING AS THE MID LEVEL WAVE KICKS THROUGH THEN TAPER
OFF IN THE AFTERNOON BEHIND THE WAVE. DECENT MIXING POTENTIAL
PARTICULARLY ACROSS THE WEST WILL ALLOW TEMPERATURES TO CLIMB INTO
60S WITH SOME LOWER 70S POSSIBLE. WEAK RIDGING NOSES INTO THE
CENTRAL PLAINS ON FRIDAY NIGHT IN THE WAKE OF THE PASSING SHORTWAVE
TROUGH. FLOW WILL TURN MORE SOUTHERLY OVERNIGHT WHICH WILL SET UP A
STRONG PUSH OF WARM AIR ADVECTION. THIS ALONG WITH INCREASING CLOUDS
LATE AT NIGHT WILL KEEP LOWS FROM FALLING BELOW THE MID 40S TO LOWER
50S.
THE NEXT DISTURBANCE IS EXPECTED TO TRACK INTO THE REGION ON
SATURDAY. MUCAPE AS HIGH AS 2500 J/KG...EFFECTIVE SHEAR OF 60 KT
WITH INCREASED MID LEVEL WINDS AND STEEP LOW LEVEL LAPSE RATES WILL
BE FOCUSED ACROSS NORTHWEST IOWA AS A WARM FRONT TRACKING
NORTHEASTWARD INTO THE OVERNIGHT HOURS. COULD SEE SOME SEVERE
THUNDERSTORM DEVELOPMENT IN THIS WEAKLY CAPPED AREA SATURDAY EVENING
INTO THE EARLY MORNING HOURS WHILE A MORE GENERAL CHANCE OF SHOWERS
AND THUNDERSTORMS ARE EXPECTED ELSEWHERE.
YET ANOTHER ROUND OF WET WEATHER RETURNS FOR SUNDAY THROUGH MONDAY
AS THE MAIN CLOSED LOW CIRCULATION FINALLY EJECTS OUT OF THE
SOUTHWESTERN STATES AND SWINGS NORTHEAST ACROSS THE CENTRAL AND
SOUTHERN PLAINS THEN INTO THE GREAT LAKES BY MONDAY AFTERNOON.
PRETTY SIGNIFICANT PRECIPITATION CHANCES ARE EXPECTED DURING THIS
PERIOD WHICH WILL BE MOST NOTABLE FOR THE MUCH COLDER POOL OF AIR
EXPECTED TO ADVECT INTO THE AREA BEHIND THE TROUGH. WHILE
PRECIPITATION WILL INITIALLY BE RAINFALL SUNDAY AND SUNDAY
EVENING...TEMPERATURES ARE EXPECTED TO FALL TO NEAR OR SLIGHTLY
BELOW FREEZING LATE SUNDAY NIGHT WITH HIGHS ON MONDAY LIKELY TO ONLY
REACH THE 40S. AT THIS POINT...EXPECT RAIN TO MIX WITH SNOW LATE
SUNDAY NIGHT/MONDAY MORNING AND POSSIBLY TRANSITION TO MAINLY SNOW
ACROSS THE NORTHWESTERN THIRD OF THE CWA.
BEHIND THIS SYSTEM...WEAK NORTHWEST FLOW SETTLES IN FOR TUESDAY AND
WEDNESDAY. MODELS HINT AT A FEW POTENTIAL WEAK WAVES MOVING THROUGH
THE NORTHERN PLAINS WITH THIS FLOW...HOWEVER THE MODELS DO NOT SHOW
MUCH AGREEMENT IN THE STRENGTH AND TIMING OF THESE FEATURES. IT DOES
LOOK LIKE A GRADUAL WARMING TREND DURING THIS PERIOD WITH
TEMPERATURES RETURNING TO NEAR OR ABOVE NORMAL.
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
SCATTERED SHOWERS WILL CONTINUE TO LIFT NORTHEAST ACROSS FAR
SOUTHEAST SOUTH DAKOTA...AND INTO NORTHWEST IOWA AND SOUTHWEST
MINNESOTA THIS AFTERNOON. SHOWERS SHOULD END AT KFSD BY 21Z...BUT
WILL LIKELY PERSIST IN THE KSUX AREA UNTIL AROUND 23Z TO 00Z. GUSTY
SOUTHEAST WINDS WILL ENCOMPASS THE REGION AND AFFECT ALL TAF SITES
THIS AFTERNOON...ESPECIALLY AFTER RAIN SHOWERS END. WINDS WILL
CONTINUE TO GUST THROUGH THE NIGHT...AND A SECOND AREA OF RAIN AND
A FEW THUNDERSTORMS WILL SPREAD ACROSS THE REGION MAINLY AFTER 06Z.
RAIN SHOULD CONTINUE INTO LATE MORNING...GRADUALLY ENDING FOR ALL
TAF SITES BETWEEN 12Z AND 15Z. CEILINGS WILL LOWER AS RAIN ENDS
FRIDAY MORNING...BUT SHOULD STAY PREDOMINANTLY MVFR. /LAFLIN
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1154 PM CDT TUE APR 10 2012
.AVIATION...
FOR THE 06Z TAFS...TSRA THREAT SHOULD BE OVER FOR OUR TAF SITES
THROUGH THE REMAINDER OF THE NIGHT...THOUGH KDHT MAY SEE A SHRA OR
TWO BETWEEN NOW AND 08Z. MVFR...AND POSSIBLY IFR...CEILINGS WILL BE
POSSIBLE BETWEEN 10 AND 15Z...THOUGH LOW CONFIDENCE FOR KDHT OR
KAMA...SO ONLY INCLUDED IN KGUY FOR NOW. THOUGH THERE IS A CHANCE FOR
TSRA AT ALL TAF SITES AFTER 20Z...DID NOT INCLUDE MENTION IN THE TAFS
FOR NOW DUE TO LOW CONFIDENCE CONSIDERING COVERAGE THE LAST TWO DAYS
HAS BEEN RATHER LIMITED.
JOHNSON
&&
.PREV DISCUSSION... /ISSUED 613 PM CDT TUE APR 10 2012/
AVIATION...
AN UPPER RIDGE WILL BE ORIENTED ACROSS THE PANHANDLES TONIGHT THROUGH
WEDNESDAY. A WEAK FRONTAL BOUNDARY ACROSS THE WESTERN TEXAS PANHANDLE
NORTHEASTWARD INTO THE NORTHEAST TEXAS PANHANDLE WILL BE THE FOCUS
THIS EVENING FOR SOME CONVECTION. CONFIDENCE IS LOW THAT CONVECTION
WILL AFFECT ANY OF THE TAF SITES THIS EVENING...SO WILL OPT TO
MENTION VCTS AT THE DALHART AND GUYMON TAF SITES UNTIL AROUND 03Z TO
06Z WEDNESDAY. VFR CONDITIONS EXPECTED WITH THE POSSIBILITY FOR SOME
MVFR CEILINGS AFTER 10Z WEDNESDAY AT THE GUYMON TAF SITE. SOUTHEAST
TO SOUTH WINDS 10 TO 20 KNOTS TONIGHT...INCREASING TO 15 TO 25 KNOTS
WITH HIGHER GUSTS AFTER 15Z WEDNESDAY.
SCHNEIDER
PREV DISCUSSION... /ISSUED 345 PM CDT TUE APR 10 2012/
DISCUSSION...
AFTERNOON VIS SATELLITE IMAGERY INDICATES DEVELOPING CU ALONG A
FRONTAL BOUNDARY LOCATED OVER THE SOUTHERN TEXAS PANHANDLE DOWN INTO
THE LOW ROLLING PLAINS. DEVELOPING CU WERE ALSO NOTED ACROSS MUCH OF
THE TX PANHANDLE WHERE TEMPERATURES HAVE WARMED INTO THE UPPER 70S TO
AROUND 80 DEGREES. A MOIST AND UNSTABLE AIR MASS LIES ACROSS THIS
AREA WITH SBCAPES BETWEEN 1500- 2500 J/KG. WHILE 0-6 KM BULK SHEAR
FROM SPC RUC MESOSCALE ANALYSIS IS NOT AT ALL IMPRESSIVE...GIVEN THE
MOIST AND UNSTABLE AIR MASS...IF ANY STORMS WERE TO DEVELOP THEY CAN
BECOME SEVERE. FURTHER NORTH ACROSS THE OK PANHANDLE...LOW CLOUDS
HAVE BEEN SLOW TO ERODE KEEPING THIS AREA UNDER A COOLER AND MORE
STABLE AIR MASS. NONETHELESS DESPITE NOT HAVING MUCH IN THE WAY OF
FORCING MECHANISMS TO INITIATE CONVECTION...MODELS INDICATE ISOLATED
DEVELOPMENT THIS EVENING WITH GREATER CHANCE FOR STORMS LATE
TONIGHT/EARLY WEDNESDAY AS CONVECTION FORMING ON THE HIGHER TERRAIN
OUT WEST...NEAR THE DRYLINE...PUSHES EASTWARD. IN ADDITION...A LOW-
LEVEL JET WILL STRENGTHEN TONIGHT WHICH MAY HELP TO GENERATE
ADDITIONAL STORMS.
UPPER-LEVEL RIDGE GETS SHUNTED FURTHER TO THE EAST WEDNESDAY AS AN
UPPER-LEVEL TROUGH DIGS INTO THE INTERMOUNTAIN WEST. PROSPECTS FOR
STORMS AND HENCE SEVERE WEATHER LOOK BETTER ON WEDNESDAY AS A VORT
MAX MOVES ACROSS THE PANHANDLES. STORMS WILL DEVELOP NEAR THE
DRYLINE IN EASTERN WHERE THEY CAN CONGEAL INTO A LINE OF STORMS THAT
WILL PUSH SOUTHEAST ACROSS THE PANHANDLES. AGAIN CONTINUED SOUTHEAST
SURFACE FLOW WILL MAINTAIN AMPLE LOW-LEVEL MOISTURE WITH AN
UNSTABLE AIR MASS IN PLACE. LARGE HAIL AND DAMAGING WINDS WILL BE
THE PRIMARY HAZARDS WITH THESE STORMS.
THE UPPER TROUGH WILL FURTHER DIG INTO THE NORTHERN ROCKIES THURSDAY
HELPING TO TRANSITION THE UPPER FLOW TO THE SOUTHWEST. A SURFACE
LEE SIDE TROUGH WILL DEEPEN ACROSS THE WESTERN HIGH PLAINS WHICH
WILL CAUSE WINDS TO PICK UP DURING THE DAY. THE DRYLINE WILL ALSO
SURGE INTO THE EASTERN ZONES...WHERE IT WILL FOCUS A CHANCE FOR
SHOWERS AND THUNDERSTORMS EAST OF THE DRYLINE WHERE WARM...MOIST...
AND UNSTABLE CONDITIONS WILL EXIST. FRIDAY LOOKS TO BE SIMILAR
ALTHOUGH EXPECT THE DRYLINE TO PUSH FURTHER EAST...WHICH SHOULD
SHUNT ANY PRECIP CHANCES OUT OF THE AREA. A LOW WILL CLOSE OFF ALONG
THE SOUTHERN PERIPHERY OF THIS BROAD UPPER TROUGH WHERE IT WILL
MOVE ACROSS THE FOUR CORNERS REGION OVER THE WEEKEND AND INTO EARLY
NEXT WEEK. BOTH THE 12Z ECMWF AND GFS HAVE COME IN DRIER WITH ANY
PRECIP CHANCES WITH THIS SYSTEM...SO HAVE CONTINUED WITH A DRY
FORECAST. ALTHOUGH A COLD FRONT WILL PUSH ACROSS THE AREA ON
MONDAY...USHERING IN COOLER TEMPERATURES.
CLK
FIRE WEATHER...
SHOWERS AND THUNDERSTORMS ARE POSSIBLE TONIGHT THROUGH WEDNESDAY
NIGHT ACROSS THE TX/OK PANHANDLES...HELPING TO MITIGATE THE FIRE
WEATHER THREAT. A DRYLINE WILL PUSH INTO THE EASTERN TX/OK
PANHANDLE THURSDAY THROUGH SATURDAY. GUSTY SOUTHWEST WINDS WILL
DEVELOP BEHIND THE DRYLINE AND ANY ELEVATED OR CRITICAL FIRE
WEATHER CONDITIONS HINGE UPON HOW MUCH PRECIP THE AREA RECEIVES
BEFORE THEN. SHOWERS AND THUNDERSTORMS ARE POSSIBLE THURSDAY AHEAD OF
THE DRYLINE. A COLD FRONT WILL PUSH ACROSS THE PANHANDLES MONDAY.
COOLER AIR BEHIND THE FRONT SHOULD KEEP MINIMUM RELATIVE HUMIDITIES
ABOVE 20 PERCENT.
CLK
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
16/02
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1121 PM MDT THU APR 12 2012
.AVIATION...
VFR CONDITIONS ARE EXPECTED AT ALL 3 TAF SITES...KPUB...KALS AND
KCOS DURING THE NEXT 24H. LIGHT WINDS ARE EXPECTED TONIGHT AND
TOMORROW MORNING...BUT GUSTY SOUTH TO SOUTHWEST WINDS WILL OCCUR
TOMORROW AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 625 PM MDT THU APR 12 2012/
UPDATE...
UPDATED TO CANCEL THE TORNADO WATCH FOR KIOWA AND PROWERS COUNTIES
FOR THIS EVENING. SATELLITE IMAGERY AND MESOSCALE ANALYSIS
INDICATE THE DRYLINE HAS MIXED EAST INTO KANSAS WITH THE MAIN
THUNDERSTORM THREAT BEING TO OUR NORTH AND EAST. REMOVED
THUNDERSTORMS FROM BOTH COUNTIES FOR THIS EVENING. NO OTHER
CHANGES TO THE FORECAST AT THIS TIME. 88
PREV DISCUSSION... /ISSUED 322 PM MDT THU APR 12 2012/
SHORT TERM...
(TONIGHT AND FRIDAY)
.SEVERE STORMS POSSIBLE NEAR THE KANSAS BORDER THIS AFTERNOON...
DRYLINE AT THIS TIME APPEARS TO BE CENTERED PARALLEL AND NEAR
HIGHWAY 287/385 THROUGH ERN PORTIONS OF BACA...PROWERS...AND KIOWA
COUNTIES. DEWPOINTS OVR THE I-25 CORRIDOR HAVE MIXED OUT TO THE
LOWER TEENS. HRRR STILL SHOWING THE POTENTIAL FOR AN ISOLD STORM OR
TWO DEVELOPING ALONG THE DRYLINE IN THE NEXT HOUR OR TWO...THEN
MOVING FAIRLY QUICKLY INTO KS. ENVIRONMENT IS STILL FAVORABLE E OF
THE DRYLINE FOR THE DEVELOPMENT OF TORNADIC SUPERCELLS...THUS THE
CURRENT TOR WATCH IN EFFECT FOR THIS AREA. 4KM WRF DOES NOT DEVELOP
ANY STRONG CONVECTION IN OUR AREA. SHOULD SEE FAIRLY SHORTLY WHETHER
THE CU FIELD OVR THE FAR SERN PLAINS WILL PRODUCE ANY PERSISTENT
CONVECTION.
FARTHER W...LOW RH AND STRENGTHENING SW WINDS HAVE LED TO MARGINAL
CRITICAL FIRE WX CONDITIONS. WITH WINDS EXPECTED TO CONTINUE TO GUST
THROUGH EARLY EVE...AND MORE DRY AIR ON THE WAY...WILL LEAVE RED
FLAG INTACT FOR THE BALANCE OF THE WARNING. HAVE ALSO CONVERTED THE
FIRE WX WATCH TO A WARNING FOR TOMORROW AFTERNOON FOR THE SAN LUIS
VALLEY...WITH CONTINUED DRY CONDITIONS AND GUSTY SW WINDS. RH SHOULD
BE ABOVE CRITICAL CRITERIA TOMORROW OVR MOST OF THE REMAINDER OF THE
DISTRICT...WITH TEMPS ALOFT FALLING OFF A BIT MORE AND RESULTANT
HIGHER HUMIDITY. EXPECT TEMPS TO VARY FROM THE 50S OVR THE SAN LUIS
VALLEY...UPR ARKANSAS...AND EL PASO-TELLER...TO THE LOWER 70S OVR
THE SERN PLAINS. SHOULD BE A GENERALLY DRY DAY E OF THE DVD. ANOTHER
SHORTWAVE IN ADVANCE OF THE BIG PACIFIC TROUGH FOR THIS WEEKEND WILL
KICK OFF SOME LIGHT SHSN OVR THE DVD DURING THE AFTERNOON...AND COULD
SEE SOME LIGHT ACCUMS OVR THE DVD BY FRI EVE. MAIN SHOW WILL COME
THIS WEEKEND...HOWEVER. 44
LONG TERM...
(FRIDAY NIGHT THROUGH NEXT THURSDAY)
OVERALL...MODEL SOLUTIONS HAVE TRENDED EVER SO SLIGHTLY BACK TO
THE SOUTH REGARDING THE TRACK OF THE UPPER LEVEL LOW ACROSS THE
STATE THIS WEEKEND...WHICH WOULD INCREASE THE THREAT OF HEAVY
PRECIPITATION OVER EASTERN PORTIONS OF THE AREA...ESPECIALLY
SUNDAY. FOR THE MOUNTAINS ALONG THE CONTINENTAL DIVIDE...SMALL
DIFFERENCES IN THE LOW TRACK WON`T HAVE A BIG IMPACT ON SNOW
AMOUNTS...AS ALMOST ALL MEDIUM RANGE MODELS HAVE A PROLONGED
PERIOD OF HEAVY SNOW FROM SATURDAY INTO AT LEAST SUNDAY NIGHT.
HAVE HOISTED A WINTER STORM WATCH FOR ALL OF THE HIGHER TERRAIN
ALONG THE DIVIDE...WHERE SNOW AMOUNTS COULD APPROACH 2 FEET OR
MORE BY LATE SUNDAY NIGHT. FARTHER EAST...NO HIGHLIGHTS YET AS
HEAVY SNOW WOULD BE SATURDAY NIGHT/SUNDAY AND SMALL CHANGES TO THE
TRACK OF THE UPPER LOW WILL HAVE A BIG IMPACT ON PRECIP AMOUNTS.
TAKEN AT FACE VALUE...GFS/ECMWF SUGGEST WARNING CRITERIA SNOWFALL
POSSIBLE OVER PIKES PEAK AND THE HIGHER PORTIONS OF THE
SANGRES...WITH A PERIOD OF HEAVY...WET...WIND DRIVEN SNOW OVER THE
PALMER DIVIDE SUNDAY MORNING. STILL A GOOD DEAL OF
UNCERTAINTY...THOUGH ALL MODELS SUGGEST AT LEAST SOME -SHRA/-SHSN
A GOOD BET LATE SATURDAY NIGHT INTO SUNDAY...AS COLD FRONT RACES
SOUTH AND UPPER LEVEL MOVES OVERHEAD. WILL THUS INCREASE POPS OVER
MOST OF THE EASTERN HALF OF THE AREA...EMPHASIZING A LATE
SAT/EARLY SUN WINDOW. MODELS APPEAR TO HANG ON TO LIGHT PRECIP TOO
LONG SUNDAY NIGHT INTO MONDAY...AS LOW AND MID LEVEL FLOW WILL BE
MAINLY DOWNSLOPE...SO WILL ONLY RUN WITH LOW POPS OVER THE HIGHER
TERRAIN MON INTO MON EVENING. RETURN TO WARMER AND DRIER WEATHER
BEGINS TUE AS FLAT UPPER RIDGE BUILDS OVER THE WESTERN U.S.
AVIATION...VFR CONDITIONS ARE EXPECTED FOR NEXT 24 H FOR THE TAF
SITES. GUSTY SW WINDS WILL PERSIST THROUGH FRI...REACHING PEAK
SPEEDS IN MID-LATE AFTERNOON. PERSISTENT SHSN WILL INCREASE OVR
THE CONTDVD ESPECIALLY BY LATE FRI...IN ADVANCE OF A LARGE STORM
SYSTEM THAT COULD AFFECT THE TERMINALS IN ERN CO THIS WEEKEND.
44
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY EVENING
FOR COZ058-060-066-068.
RED FLAG WARNING FROM NOON TO 8 PM MDT FRIDAY FOR COZ224.
&&
$$
34/34
AREA FORECAST DISCUSSION...CORRECTED
NWS MOUNT HOLLY NJ
347 AM EDT FRI APR 13 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD SOUTH OUT OF CANADA AND ACROSS MUCH OF THE
EAST TODAY AND WILL BUILD OFF THE SOUTHEAST COAST THIS WEEKEND INTO
EARLY NEXT WEEK. AN AREA OF LOW PRESSURE IS EXPECTED TO MOVE THROUGH
THE WESTERN GREAT LAKES REGION AND INTO EASTERN CANADA OVER THE
WEEKEND. A COLD FRONT IS EXPECTED TO STALL JUST NORTH OF THE AREA
OVER WEEKEND INTO EARLY NEXT WEEK. LOW PRESSURE IS FORECAST TO FORM
ACROSS THE SOUTHERN PLAINS AND MOVE ALONG THE BOUNDARY TOWARD
OUR AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE EARLY MORNING FROST/FREEZE HEADLINES WILL REMAIN IN PLACE.
WIDELY SCATTERED SHOWERS CONTINUE TO DRIFT SOUTH THIS MORNING JUST
OFF THE NEW JERSEY COAST. THE SHOWERS APPEAR TO BE IN RESPONSE TO
COLD MID LEVEL TEMPERATURES AND JUST ENOUGH MOISTURE IN THE COLUMN.
0000 UTC SOUNDINGS SHOWED AN INVERTED V SIGNATURE WITH VERY DRY
CONDITIONS BELOW THE INVERSION...SURFACE OBSERVATIONS OVER WESTERN
LONG ISLAND AND NEW YORK CITY SHOW SOME OF THE RAIN IS REACHING THE
GROUND. THE LATEST HRRR RUN SUGGESTS THAT THE SHOWERS RUN OUT OF
STEAM BEFORE SUNRISE...AND BARRING AN INCREASING TREND WILL NOT BE
INCLUDED IN THE EARLY PORTION OF THE NEW FORECAST.
A BATCH OF MAINLY CIRRUS AND MID LEVEL CLOUDINESS CONTINUES TO
AFFECT MARYLAND AND DELAWARE EARLY THIS MORNING. THE CLOUDINESS
APPEARS TO HAVE BEEN INDUCED BY A 110 KT JET DROPPING INTO THE MID
ATLANTIC STATES. THIS CLOUDINESS SHOULD BE EAST OF THE AREA BEFORE
SUNRISE.
AS THE MID LEVEL LONG WAVE TROUGH CONTINUES TO TRUNDLE TO THE
EAST...ITS INFLUENCE WILL LESSEN AS THE DAY PROGRESSES. A SHORT WAVE
OVER THE GREAT LAKES EARLY THIS MORNING SHOULD DIVE SOUTHEAST AND
PASS WELL TO THE SOUTHWEST THIS AFTERNOON. THIS FEATURE SHOULD HAVE
LITTLE TO NO EFFECT ON THE REGION TODAY.
THE MID LEVEL REMAIN FAIRLY COLD. THIS COMBINED WITH STRONG WARMING
(AS NEAR SURFACE LAPSE RATES APPROACH DRY ADIABATIC) SHOULD ALLOW
THE LIMITED AMOUNT OF AVAILABLE MOISTURE TO POOL UNDER THE
INVERSION. THIS IN TURN SHOULD ALLOW SOME CUMULUS TO DEVELOP...BUT
CONVECTIVE TEMPERATURES SHOULD EDGE JUST OUT OF REACH DURING THE
AFTERNOON. OVERALL...THERE SHOULD BE LESS IN THE WAY OF CLOUDINESS
THAN THE PAST FEW DAYS.
WHILE LOW AND MID LEVEL LAPSE RATES SHOULD BE FAIRLY STEEP...THERE
DOES NOT APPEAR TO BE ENOUGH MOISTURE IN THE COLUMN FOR EVEN
ISOLATED SHOWERS TODAY. BASED ON THIS...THE FORECAST WILL REMAIN DRY
FOR TODAY.
AFTER A COOL START...THE DRY AIRMASS SHOULD WARM FAIRLY QUICKLY. AS
THE COLUMN WARMS...FULL SUN TEMPERATURES SHOULD REACH THE MID 60S
SOUTH AND THE MID TO UPPER 50S NORTH. THIS SI CLOSE TO WHAT THE MOS
BLEND IS SHOWING. THE HIGH TEMPERATURES FORECAST WAS A BLEND OF MOS
NUMBERS AND CONTINUITY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
ANY CUMULUS THAT DEVELOPS IN THE DAYTIME HEATING TODAY SHOULD MELT
AWAY FAIRLY QUICKLY THIS EVENING. AS MID LEVEL HEIGHTS RISE TONIGHT
AHEAD OF A RIDGE...FOR THE MOST PART CLOUDINESS SHOULD BE AT A
MINIMUM. SO HIGH CLOUDINESS COULD BREACH THE RIDGE LATER TONIGHT...
BUT MAINLY CLEAR OR CLEAR SKIES SHOULD COVER IT TONIGHT.
AS SURFACE HIGH PRESSURE REPOSITIONS ITSELF OFF THE MID ATLANTIC
COAST THIS EVENING...THE PRESSURE GRADIENT FLOW COULD PRODUCE A
LIGHT WEST WINDS FOR MOST AREAS. THE LIGHT WEST WINDS COULD BE THE
ONLY INHIBITING FACTOR FOR GOOD RADIATIONAL COOLING TONIGHT...AND IT
MAY NOT BE THAT MUCH OF A PROBLEM IN PROTECTED AREAS. FOR THE MOST
PART...LOWS WERE BASED MAINLY ON THE SLIGHT COOLER NAM MOS NUMBERS.
THERE IS A SHOT AT FREEZING TEMPERATURES IN THE COLDEST LOCATIONS OF
THE PINE BARRENS EARLY SATURDAY MORNING. CONFIDENCE IN THIS IS NOT
HIGH YET...AS DEW POINTS COULD SLOW THE FALL LATE TONIGHT.
ELSEWHERE...THE LIGHT WEST FLOW COULD PREVENT MOST AREAS FROM
DROPPING BELOW FREEZING. THEREFORE...WILL LET THE MORNING
FROST/FREEZE HEADLINES RIDE...AND THE DAY CREW CAN GET A LOOK AT THE
FROST POTENTIAL FOR TONIGHT AND SATURDAY MORNING.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL BUILD SOUTH OF THE AREA ON SATURDAY AND ANCHOR
ITSELF OFF THE SOUTHEAST COAST OVER THE WEEKEND. AN AREA OF LOW
PRESSURE WILL BE LIFTING OUT OF THE NORTH CENTRAL US AND INTO
EASTERN CANADA THROUGH THE WEEKEND. AS THIS HAPPENS, A WARM FRONT IS
EXPECTED TO LIFT THROUGH OUR AREA LATE SATURDAY INTO SATURDAY NIGHT,
WHILE A FEW SHORT WAVES/VORT MAXES CROSS THE AREA. THIS COULD HELP
LEAD TO SOME PRECIPITATION ACTIVITY LATE SATURDAY INTO SATURDAY
NIGHT.
BY SUNDAY, A SECOND LOW PRESSURE SYSTEM WILL BE STRENGTHENING ACROSS
THE SOUTHERN PLAINS ALONG A FRONTAL BOUNDARY THAT WILL EXTEND FROM
THE LOW PRESSURE IN CANADA INTO THE SOUTHERN PLAINS AREA. THE
FRONTAL BOUNDARY WILL LIKELY STALL TO OUR NORTH AS THE SECOND LOW
PRESSURE SYSTEM MOVES ALONG THIS BOUNDARY TOWARD THE GREAT LAKES
REGION LATE IN THE WEEKEND INTO EARLY NEXT WEEK. EVENTUALLY, A
SECOND FRONTAL BOUNDARY ASSOCIATED WITH THE SECOND LOW PRESSURE
SYSTEM WILL CROSS OUR AREA. RIGHT NOW IT LOOKS LIKE THE MAY OCCUR
AROUND THE TUESDAY TIME PERIOD.
WHILE SUNDAY INTO MONDAY SHOULD REMAIN MOSTLY DRY WITH THE FRONT
REMAINING TO OUR NORTH, ANY SHORT WAVES/VORT MAXES COULD SPARK SOME
SHOWER ACTIVITY. HOWEVER, THIS MAY MOSTLY OCCUR ACROSS MOSTLY OUR
NORTHERN AREAS. PRECIPITATION CHANCES INCREASE STARTING MONDAY NIGHT
AND CONTINUE THROUGH WEDNESDAY WITH THE APPROACH AND PASSAGE OF THE
FRONTAL BOUNDARY. THE ECMWF DEVELOPS ANOTHER LOW ALONG THE FRONTAL
BOUNDARY WEDNESDAY INTO THURSDAY, WHICH WOULD KEEP RAIN CHANCES
ACROSS THE AREA, HOWEVER THE GFS DOES NOT INDICATE THIS. THIS IS AT
THE VERY END OF THE EXTENDED, SO WE WILL NOT MAKE MUCH CHANGE TO THE
CURRENT FORECAST THAT FAR OUT WHICH KEEPS A SLIGHT CHANCE OF
RAIN.
NOW THAT THE GFS HAS PUSHED THE SYSTEM FARTHER NORTH IN THE LAST FEW
RUNS, IT IS AGREEING WITH THE ECMWF AT MONDAY BEING A VERY WARM DAY.
DEPENDING ON WHEN THE FRONT MOVES THROUGH, TUESDAY COULD BE ANOTHER
WARM DAY AS WELL. TEMPERATURES SHOULD RETURN CLOSER TO NORMAL BEHIND
THE FRONTAL PASSAGE LATER IN THE WEEK.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR CONDITIONS CONTINUE EARLY THIS MORNING AS MID CLOUDS DRIFT SOUTH
ACROSS THE AREA. SCATTERED SHOWERS REMAIN JUST OFFSHORE...AND EVEN
KACY DOES NOT LOOK TO BE AFFECTED BY THE EARLY MORNING SHOWERS.
VFR CONDITIONS ARE EXPECTED TODAY. THERE SHOULD BE LESS IN THE WAY
OF CUMULUS DEVELOPMENT TODAY...AND THE AIRMASS LOOKS TOO DRY FOR
EVEN ISOLATED SHOWERS. THE GRADIENT WILL SUPPORT WINDS AROUND 10
KNOTS THIS MORNING FROM THE NORTH...AND BACKING WINDS THIS AFTERNOON
SHOULD BE CAPPED AT 12 KNOTS.
VFR CONDITIONS ARE EXPECTED TONIGHT WITH A LIGHT WESTERLY WIND.
OUTLOOK...
SATURDAY...VFR GUSTY WEST-SOUTHWEST WIND SATURDAY.
SATURDAY NIGHT...MOSTLY VFR WITH SCATTERED RAIN SHOWERS.
SUNDAY-MONDAY NIGHT...MOSTLY VFR WITH SCATTERED RAIN SHOWERS. GUSTY
WEST TO SOUTHWEST WINDS EACH AFTERNOON.
TUESDAY...VFR WITH SCATTERED AFTERNOON THUNDERSTORMS...POSSIBLE
LOWER CIG/VSBY IN THUNDERSTORMS.
&&
.MARINE...
WINDS AND SEAS REMAIN BELOW SMALL CRAFT LEVELS EARLY THIS MORNING AS
THE BEST PRESSURE GRADIENT MOVES EAST OF THE WATERS. HIGH PRESSURE
BUILDING EAST FROM THE GREAT LAKES WILL PRODUCE A NORTHERLY WIND
THIS MORNING. AS A PIECE OF THE HIGH REACHES THE MID ATLANTIC COAST
THIS AFTERNOON...WINDS WILL BACK TO WEST AND SOUTHWEST...GENERALLY
REMAINING UNDER 15 KNOTS. THE PRESSURE GRADIENT COULD BACK OFF
ENOUGH LATE THIS AFTERNOON TO ALLOW SEA BREEZE CIRCULATIONS TO
DEVELOP ALONG THE NEW JERSEY COAST.
THE HIGH WILL REPOSITION ITSELF ALONG THE NORTH CAROLINA COAST
TONIGHT. ANY SEA BREEZE CIRCULATIONS WILL SNAP BACK TO THE WEST
SOUTHWEST SYNOPTIC FLOW. WINDS COULD GET TO 15 KNOTS ACROSS THE
OCEAN WATERS AS THE PRESSURE GRADIENT TIGHTENS LATE THIS
EVENING...BUT SUB ADVISORY CONDITIONS ARE EXPECTED TONIGHT.
OUTLOOK...
HIGH PRESSURE WILL BUILD OFF THE SOUTHEAST COAST ON SATURDAY AND
REMAIN THERE INTO EARLY NEXT WEEK. AT THE SAME TIME, A SERIES OF LOW
PRESSURE SYSTEMS ARE FORECAST TO MOVE ALONG A SLOW MOVING FRONTAL
BOUNDARY THAT MAY STALL JUST TO OUR NORTH SUNDAY INTO MONDAY. THE
PRESSURE GRADIENT WILL TIGHTEN BETWEEN THE HIGH TO OUR SOUTH AND THE
LOWS MOVING TO OUR NORTH, AND COULD CREATE AN EXTENDED PERIOD OF
SMALL CRAFT ADVISORY, OR AT LEAST NEAR SMALL CRAFT ADVISORY LEVELS
WINDS, LASTING FROM LATE SATURDAY INTO AT LEAST LATE MONDAY. THE
WINDS ABOVE THE SURFACE ARE FORECAST TO BE QUITE STRONG DURING THIS
TIME PERIOD, BUT THE CONFIDENCE ON THE STRONG WINDS MIXING DOWN TO
THE WATERS IS NOT HIGH. HOWEVER, IF THEY DID MIX DOWN, WE COULD GET
GALE FORCE WINDS, BUT WE DO NOT HAVE THIS IN THE FORECAST FOR NOW.
&&
.FIRE WEATHER...
THE AIRMASS WILL BE DRIER TODAY THAN THE PAST COUPLE OF DAYS...AS
MINIMUM RELATIVE HUMIDITY VALUES DROP BELOW 25 PERCENT ACROSS A GOOD
CHUNK OF THE AREA. WHILE THERE WERE A FEW SHOWERS AROUND THURSDAY
AFTERNOON...THE RAIN THEY PRODUCED DID NOT DO MUCH TO ALLEVIATE THE
DRY FUEL CONDITIONS.
IT APPEARS AS THOUGH THE LIMITING FACTOR TODAY FOR RED FLAG
CONDITIONS WILL BE THE WIND. THE BEST PRESSURE GRADIENT WILL OCCUR
THIS AFTERNOON AS HIGH PRESSURE STRETCHES FROM THE OHIO VALLEY TO
THE MID ATLANTIC STATES. MODEL SOUNDINGS DO NOT SHOW MUCH SUPPORT
FOR GUSTY WINDS...AND WINDS LOOK TO REMAIN BELOW RED FLAG CRITERIA.
SATURDAY NOW APPEARS IT WILL BE ANOTHER DRY AND WINDY DAY, WHICH
WILL CONTINUE ENHANCED FIRE SPREAD CONCERNS.
&&
.CLIMATE...
POTENTIAL FOR NEAR RECORD HEAT MONDAY.
HERE ARE THE RECORD HIGH TEMPERATURES FOR ALL 8 OF OUR CLIMATE SITES
FOR MONDAY AND TUESDAY.
4/16 4/17
ALLENTOWN 89 - 2002 91 - 2002, 1976
ATLANTIC CITY 89 - 2002 94 - 2002
GEORGETOWN 89 - 2002 94 - 2002
MOUNT POCONO 85 - 2002 87 - 2002
PHILADELPHIA 90 - 2002 95 - 2002
READING 88 - 2002 95 - 1976
TRENTON 90 - 2002 93 - 2002
WILMINGTON 92 - 1896 97 - 1896
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR PAZ060-067.
FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR PAZ054-055-061-
062.
NJ...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NJZ008>010-
020>022-027.
FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR NJZ001-007.
DE...NONE.
MD...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MDZ008.
MARINE...NONE.
&&
$$
SYNOPSIS...ROBERTSON
NEAR TERM...HAYES
SHORT TERM...HAYES
LONG TERM...ROBERTSON
AVIATION...HAYES/ROBERTSON
MARINE...HAYES/ROBERTSON
FIRE WEATHER...HAYES/ROBERTSON
CLIMATE...DRAG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
334 AM EDT FRI APR 13 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD SOUTH OUT OF CANADA AND ACROSS MUCH OF THE
EAST TODAY AND WILL BUILD OFF THE SOUTHEAST COAST THIS WEEKEND INTO
EARLY NEXT WEEK. AN AREA OF LOW PRESSURE IS EXPECTED TO MOVE THROUGH
THE WESTERN GREAT LAKES REGION AND INTO EASTERN CANADA OVER THE
WEEKEND. A COLD FRONT IS EXPECTED TO STALL JUST NORTH OF THE AREA
OVER WEEKEND INTO EARLY NEXT WEEK. LOW PRESSURE IS FORECAST TO FORM
ACROSS THE SOUTHERN PLAINS AND MOVE ALONG THE BOUNDARY TOWARD
OUR AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE EARLY MORNING FROST/FREEZE HEADLINES WILL REMAIN IN PLACE.
WIDELY SCATTERED SHOWERS CONTINUE TO DRIFT SOUTH THIS MORNING JUST
OFF THE NEW JERSEY COAST. THE SHOWERS APPEAR TO BE IN RESPONSE TO
COLD MID LEVEL TEMPERATURES AND JUST ENOUGH MOISTURE IN THE COLUMN.
0000 UTC SOUNDINGS SHOWED AN INVERTED V SIGNATURE WITH VERY DRY
CONDITIONS BELOW THE INVERSION...SURFACE OBSERVATIONS OVER WESTERN
LONG ISLAND AND NEW YORK CITY SHOW SOME OF THE RAIN IS REACHING THE
GROUND. THE LATEST HRRR RUN SUGGESTS THAT THE SHOWERS RUN OUT OF
STEAM BEFORE SUNRISE...AND BARRING AN INCREASING TREND WILL NOT BE
INCLUDED IN THE EARLY PORTION OF THE NEW FORECAST.
A BATCH OF MAINLY CIRRUS AND MID LEVEL CLOUDINESS CONTINUES TO
AFFECT MARYLAND AND DELAWARE EARLY THIS MORNING. THE CLOUDINESS
APPEARS TO HAVE BEEN INDUCED BY A 110 KT JET DROPPING INTO THE MID
ATLANTIC STATES. THIS CLOUDINESS SHOULD BE EAST OF THE AREA BEFORE
SUNRISE.
AS THE MID LEVEL LONG WAVE TROUGH CONTINUES TO TRUNDLE TO THE
EAST...ITS INFLUENCE WILL LESSEN AS THE DAY PROGRESSES. A SHORT WAVE
OVER THE GREAT LAKES EARLY THIS MORNING SHOULD DIVE SOUTHEAST AND
PASS WELL TO THE SOUTHWEST THIS AFTERNOON. THIS FEATURE SHOULD HAVE
LITTLE TO NO EFFECT ON THE REGION TODAY.
THE MID LEVEL REMAIN FAIRLY COLD. THIS COMBINED WITH STRONG WARMING
(AS NEAR SURFACE LAPSE RATES APPROACH DRY ADIABATIC) SHOULD ALLOW
THE LIMITED AMOUNT OF AVAILABLE MOISTURE TO POOL UNDER THE
INVERSION. THIS IN TURN SHOULD ALLOW SOME CUMULUS TO DEVELOP...BUT
CONVECTIVE TEMPERATURES SHOULD EDGE JUST OUT OF REACH DURING THE
AFTERNOON. OVERALL...THERE SHOULD BE LESS IN THE WAY OF CLOUDINESS
THAN THE PAST FEW DAYS.
WHILE LOW AND MID LEVEL LAPSE RATES SHOULD BE FAIRLY STEEP...THERE
DOES NOT APPEAR TO BE ENOUGH MOISTURE IN THE COLUMN FOR EVEN
ISOLATED SHOWERS TODAY. BASED ON THIS...THE FORECAST WILL REMAIN DRY
FOR TODAY.
AFTER A COOL START...THE DRY AIRMASS SHOULD WARM FAIRLY QUICKLY. AS
THE COLUMN WARMS...FULL SUN TEMPERATURES SHOULD REACH THE MID 60S
SOUTH AND THE MID TO UPPER 50S NORTH. THIS SI CLOSE TO WHAT THE MOS
BLEND IS SHOWING. THE HIGH TEMPERATURES FORECAST WAS A BLEND OF MOS
NUMBERS AND CONTINUITY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
ANY CUMULUS THAT DEVELOPS IN THE DAYTIME HEATING TODAY SHOULD MELT
AWAY FAIRLY QUICKLY THIS EVENING. AS MID LEVEL HEIGHTS RISE TONIGHT
AHEAD OF A RIDGE...FOR THE MOST PART CLOUDINESS SHOULD BE AT A
MINIMUM. SO HIGH CLOUDINESS COULD BREACH THE RIDGE LATER TONIGHT...
BUT MAINLY CLEAR OR CLEAR SKIES SHOULD COVER IT TONIGHT.
AS SURFACE HIGH PRESSURE REPOSITIONS ITSELF OFF THE MID ATLANTIC
COAST THIS EVENING...THE PRESSURE GRADIENT FLOW COULD PRODUCE A
LIGHT WEST WINDS FOR MOST AREAS. THE LIGHT WEST WINDS COULD BE THE
ONLY INHIBITING FACTOR FOR GOOD RADIATIONAL COOLING TONIGHT...AND IT
MAY NOT BE THAT MUCH OF A PROBLEM IN PROTECTED AREAS. FOR THE MOST
PART...LOWS WERE BASED MAINLY ON THE SLIGHT COOLER NAM MOS NUMBERS.
THERE IS A SHOT AT FREEZING TEMPERATURES IN THE COLDEST LOCATIONS OF
THE PINE BARRENS EARLY SATURDAY MORNING. CONFIDENCE IN THIS IS NOT
HIGH YET...AS DEW POINTS COULD SLOW THE FALL LATE TONIGHT.
ELSEWHERE...THE LIGHT WEST FLOW COULD PREVENT MOST AREAS FROM
DROPPING BELOW FREEZING. THEREFORE...WILL LET THE MORNING
FROST/FREEZE HEADLINES RIDE...AND THE DAY CREW CAN GET A LOOK AT THE
FROST POTENTIAL FOR TONIGHT AND SATURDAY MORNING.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL BUILD SOUTH OF THE AREA ON SATURDAY AND ANCHOR
ITSELF OFF THE SOUTHEAST COAST OVER THE WEEKEND. AN AREA OF LOW
PRESSURE WILL BE LIFTING OUT OF THE NORTH CENTRAL US AND INTO
EASTERN CANADA THROUGH THE WEEKEND. AS THIS HAPPENS, A WARM FRONT IS
EXPECTED TO LIFT THROUGH OUR AREA LATE SATURDAY INTO SATURDAY NIGHT,
WHILE A FEW SHORT WAVES/VORT MAXES CROSS THE AREA. THIS COULD HELP
LEAD TO SOME PRECIPITATION ACTIVITY LATE SATURDAY INTO SATURDAY
NIGHT.
BY SUNDAY, A SECOND LOW PRESSURE SYSTEM WILL BE STRENGTHENING ACROSS
THE SOUTHERN PLAINS ALONG A FRONTAL BOUNDARY THAT WILL EXTEND FROM
THE LOW PRESSURE IN CANADA INTO THE SOUTHERN PLAINS AREA. THE
FRONTAL BOUNDARY WILL LIKELY STALL TO OUR NORTH AS THE SECOND LOW
PRESSURE SYSTEM MOVES ALONG THIS BOUNDARY TOWARD THE GREAT LAKES
REGION LATE IN THE WEEKEND INTO EARLY NEXT WEEK. EVENTUALLY, A
SECOND FRONTAL BOUNDARY ASSOCIATED WITH THE SECOND LOW PRESSURE
SYSTEM WILL CROSS OUR AREA. RIGHT NOW IT LOOKS LIKE THE MAY OCCUR
AROUND THE TUESDAY TIME PERIOD.
WHILE SUNDAY INTO MONDAY SHOULD REMAIN MOSTLY DRY WITH THE FRONT
REMAINING TO OUR NORTH, ANY SHORT WAVES/VORT MAXES COULD SPARK SOME
SHOWER ACTIVITY. HOWEVER, THIS MAY MOSTLY OCCUR ACROSS MOSTLY OUR
NORTHERN AREAS. PRECIPITATION CHANCES INCREASE STARTING MONDAY NIGHT
AND CONTINUE THROUGH WEDNESDAY WITH THE APPROACH AND PASSAGE OF THE
FRONTAL BOUNDARY. THE ECMWF DEVELOPS ANOTHER LOW ALONG THE FRONTAL
BOUNDARY WEDNESDAY INTO THURSDAY, WHICH WOULD KEEP RAIN CHANCES
ACROSS THE AREA, HOWEVER THE GFS DOES NOT INDICATE THIS. THIS IS AT
THE VERY END OF THE EXTENDED, SO WE WILL NOT MAKE MUCH CHANGE TO THE
CURRENT FORECAST THAT FAR OUT WHICH KEEPS A SLIGHT CHANCE OF
RAIN.
NOW THAT THE GFS HAS PUSHED THE SYSTEM FARTHER NORTH IN THE LAST FEW
RUNS, IT IS AGREEING WITH THE ECMWF AT MONDAY BEING A VERY WARM DAY.
DEPENDING ON WHEN THE FRONT MOVES THROUGH, TUESDAY COULD BE ANOTHER
WARM DAY AS WELL. TEMPERATURES SHOULD RETURN CLOSER TO NORMAL BEHIND
THE FRONTAL PASSAGE LATER IN THE WEEK.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR CONDITIONS CONTINUE EARLY THIS MORNING AS MID CLOUDS DRIFT SOUTH
ACROSS THE AREA. SCATTERED SHOWERS REMAIN JUST OFFSHORE...AND EVEN
KACY DOES NOT LOOK TO BE AFFECTED BY THE EARLY MORNING SHOWERS.
VFR CONDITIONS ARE EXPECTED TODAY. THERE SHOULD BE LESS IN THE WAY
OF CUMULUS DEVELOPMENT TODAY...AND THE AIRMASS LOOKS TOO DRY FOR
EVEN ISOLATED SHOWERS. THE GRADIENT WILL SUPPORT WINDS AROUND 10
KNOTS THIS MORNING FROM THE NORTH...AND BACKING WINDS THIS AFTERNOON
SHOULD BE CAPPED AT 12 KNOTS.
VFR CONDITIONS ARE EXPECTED TONIGHT WITH A LIGHT WESTERLY WIND.
OUTLOOK...
SATURDAY...VFR GUSTY WEST-SOUTHWEST WIND SATURDAY.
SATURDAY NIGHT...MOSTLY VFR WITH SCATTERED RAIN SHOWERS.
SUNDAY-MONDAY NIGHT...MOSTLY VFR WITH SCATTERED RAIN SHOWERS. GUSTY
WEST TO SOUTHWEST WINDS EACH AFTERNOON.
TUESDAY...VFR WITH SCATTERED AFTERNOON THUNDERSTORMS...POSSIBLE
LOWER CIG/VSBY IN THUNDERSTORMS.
&&
.MARINE...
WINDS AND SEAS REMAIN BELOW SMALL CRAFT LEVELS EARLY THIS MORNING AS
THE BEST PRESSURE GRADIENT MOVES EAST OF THE WATERS. HIGH PRESSURE
BUILDING EAST FROM THE GREAT LAKES WILL PRODUCE A NORTHERLY WIND
THIS MORNING. AS A PIECE OF THE HIGH REACHES THE MID ATLANTIC COAST
THIS AFTERNOON...WINDS WILL BACK TO WEST AND SOUTHWEST...GENERALLY
REMAINING UNDER 15 KNOTS. THE PRESSURE GRADIENT COULD BACK OFF
ENOUGH LATE THIS AFTERNOON TO ALLOW SEA BREEZE CIRCULATIONS TO
DEVELOP ALONG THE NEW JERSEY COAST.
THE HIGH WILL REPOSITION ITSELF ALONG THE NORTH CAROLINA COAST
TONIGHT. ANY SEA BREEZE CIRCULATIONS WILL SNAP BACK TO THE WEST
SOUTHWEST SYNOPTIC FLOW. WINDS COULD GET TO 15 KNOTS ACROSS THE
OCEAN WATERS AS THE PRESSURE GRADIENT TIGHTENS LATE THIS
EVENING...BUT SUB ADVISORY CONDITIONS ARE EXPECTED TONIGHT.
OUTLOOK...
HIGH PRESSURE WILL BUILD OFF THE SOUTHEAST COAST ON SATURDAY AND
REMAIN THERE INTO EARLY NEXT WEEK. AT THE SAME TIME, A SERIES OF LOW
PRESSURE SYSTEMS ARE FORECAST TO MOVE ALONG A SLOW MOVING FRONTAL
BOUNDARY THAT MAY STALL JUST TO OUR NORTH SUNDAY INTO MONDAY. THE
PRESSURE GRADIENT WILL TIGHTEN BETWEEN THE HIGH TO OUR SOUTH AND THE
LOWS MOVING TO OUR NORTH, AND COULD CREATE AN EXTENDED PERIOD OF
SMALL CRAFT ADVISORY, OR AT LEAST NEAR SMALL CRAFT ADVISORY LEVELS
WINDS, LASTING FROM LATE SATURDAY INTO AT LEAST LATE MONDAY. THE
WINDS ABOVE THE SURFACE ARE FORECAST TO BE QUITE STRONG DURING THIS
TIME PERIOD, BUT THE CONFIDENCE ON THE STRONG WINDS MIXING DOWN TO
THE WATERS IS NOT HIGH. HOWEVER, IF THEY DID MIX DOWN, WE COULD GET
GALE FORCE WINDS, BUT WE DO NOT HAVE THIS IN THE FORECAST FOR NOW.
&&
.FIRE WEATHER...
THE AIRMASS WILL BE DRIER TODAY THAN THE PAST COUPLE OF DAYS...AS
MINIMUM RELATIVE HUMIDITY VALUES DROP BELOW 25 PERCENT ACROSS A GOOD
CHUNK OF THE AREA. WHILE THERE WERE A FEW SHOWERS AROUND THURSDAY
AFTERNOON...THE RAIN THEY PRODUCED DID NOT DO MUCH TO ALLEVIATE THE
DRY FUEL CONDITIONS.
IT APPEARS AS THOUGH THE LIMITING FACTOR TODAY FOR RED FLAG
CONDITIONS WILL BE THE WIND. THE BEST PRESSURE GRADIENT WILL OCCUR
THIS AFTERNOON AS HIGH PRESSURE STRETCHES FROM THE OHIO VALLEY TO
THE MID ATLANTIC STATES. MODEL SOUNDINGS DO NOT SHOW MUCH SUPPORT
FOR GUSTY WINDS...AND WINDS LOOK TO REMAIN BELOW RED FLAG CRITERIA.
WHILE A RED FLAG WARNING DOES NOT APPEAR TO BE WARRANTED FOR
TODAY...THE LOW RELATIVE HUMIDITY VALUES AND DRY FINE FUELS DO
WARRANT A SPECIAL WEATHER STATEMENT FOR ENHANCED FIRE DANGER.
SATURDAY NOW APPEARS IT WILL BE ANOTHER DRY AND WINDY DAY, WHICH
WILL CONTINUE ENHANCED FIRE SPREAD CONCERNS.
&&
.CLIMATE...
POTENTIAL FOR NEAR RECORD HEAT MONDAY.
HERE ARE THE RECORD HIGH TEMPERATURES FOR ALL 8 OF OUR CLIMATE SITES
FOR MONDAY AND TUESDAY.
4/16 4/17
ALLENTOWN 89 - 2002 91 - 2002, 1976
ATLANTIC CITY 89 - 2002 94 - 2002
GEORGETOWN 89 - 2002 94 - 2002
MOUNT POCONO 85 - 2002 87 - 2002
PHILADELPHIA 90 - 2002 95 - 2002
READING 88 - 2002 95 - 1976
TRENTON 90 - 2002 93 - 2002
WILMINGTON 92 - 1896 97 - 1896
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR PAZ060-067.
FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR PAZ054-055-061-
062.
NJ...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NJZ008>010-
020>022-027.
FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR NJZ001-007.
DE...NONE.
MD...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MDZ008.
MARINE...NONE.
&&
$$
SYNOPSIS...ROBERTSON
NEAR TERM...HAYES
SHORT TERM...HAYES
LONG TERM...ROBERTSON
AVIATION...HAYES/ROBERTSON
MARINE...HAYES/ROBERTSON
FIRE WEATHER...HAYES/ROBERTSON
CLIMATE...DRAG
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
459 AM EDT FRI APR 13 2012
.SYNOPSIS...
ISSUED AT 453 AM EDT FRI APR 13 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH OVER
THE WRN CONUS AND A DOWNSTREAM RIDG FROM ERN TX INTO THE UPPER MS
VALLEY. A VIGOROUS SHORTWAVE TROUGH OVER WRN KS WAS LIFTING NE. AT
THE SFC...SE FLOW WAS INCREASING OVER MN AND WRN WI BTWN HIGH PRES
OVER LAKE HURON AND A TROUGH OVER THE PLAINS. IR LOOP SHOWED HIGH
CLOUDS EXPANDING INTO WRN UPPER MI ASSOCIATED WITH THE DEVELOPING
WAA PATTERN TO THE WEST.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 453 AM EDT FRI APR 13 2012
TODAY INTO TONIGHT...
HIGH AND MID CLOUDS WILL CONTINUE TO SPREAD INTO THE CWA. THE CLOUDS
SHOULD BE THIN ENOUGH TO ALLOW PLENTY OF SUNSHINE AND DECENT MIXING
ALONG WITH WAA TO PUSH TEMPS INTO UPPER 50S AND LOWER 60S. THIS
SHOULD ALSO KEEP DEWPOINTS IN THE LOWER 20S OVER MUCH OF THE
AREA...RESULTING IN RH VALUES IN THE 20 TO 25 PERCENT RANGE. THE DRY
AIR COMBINED WITH SOUTH WINDS OF 10 TO 20 MPH WILL LEAD TO ELEVATED
FIRE WX RISK. SO...WL CONTINUE TO HIGHLIGHT THE HAZARD WITH THE
WILDFIRE POTENTIAL STATEMENT.
MDLS SUGGEST THAT AS THE PLAINS SHRTWV LIFTS INTO THE UPPER MS
VALLEY AND WRN LAKE SUPERIOR...MODERATE 700-500 MB QVECTOR CONV...
WAA/ISENTROPIC LIFT ALONG WITH FAVORABLE MOISTURE TRANSPORT WILL
PRODUCE SCT/NMRS SHRA. MODELS CONTINUED WITH THE TREND TOWARD A
LATER ARRIVAL OF PCPN INTO THE WEST BUT THEN MOVE THE BAND QUICKLY THROUGH
THE WEST IN THE EVENING. EXPECT THE GREATEST PCPN COVERAGE/POPS OVER
THE NW HALF OF THE CWA...CLOSER TO THE PATH OF THE SHRTWV AND UPPER
LEVEL DIV WITH THE LEFT EXIT REGION OF THE 250-300 MB JET. SINCE THE
DYNAMICS MOVE INTO THE DRY AIRMASS FAIRLY QUICKLY ...ONLY LIGHT PCPN
AMOUNTS OF A TENTH OF AN INCH OR LESS ARE EXPECTED. WITH ELEVATED
CAPE REMAINING SOUTH OF THE AREA...PER NAM/GFS...NO TSRA ARE
EXPECTED. THE PCPN SHOULD DIMINISH OVER THE WEST BY LATE EVENING AND
OVER THE CENTRAL AND EAST AFTER MIDNIGHT.
SATURDAY...ANY LINGERING PCPN OVER THE ERN CWA SHOULD MOVE OUT EARLY
AS THE AREA FALLS UNDER THE DRY SLOT. 850 MB TEMPS TO AROUND 10C
ALONG WITH SUNSHINE SHOULD PUSH TEMPS TO AROUND 70.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 453 AM EDT FRI APR 13 2012
SAT NGT...AS FAIRLY POTENT SHRTWV BEGINS TO LIFT NEWD OUT OF THE SW
CONUS...SFC LO PRES IS FCST TO DVLP IN THE CENTRAL PLAINS. THE 00Z
GFS/NAM HAVE TRENDED TOWARD A DEEPER LO PRES FARTHER TO THE N THAN
THE 12Z ECMWF AND 00Z CNDN/UKMET. PER NCEP GUIDANCE...WL FOLLOW THE
SCENARIO CLOSER TO THE 12Z ECMWF/21Z SREF. THIS GUIDANCE SHOWS A
WEAK HI PRES RDG IN THE WAKE OF DISTURBANCE RESPONSIBLE FOR THE SAT
POPS BRINGING A BRIEF PERIOD OF DRY WX SAT EVNG. HOWEVER...APRCH OF
ATTENDANT WARM FNT AND UPR DVGC IN RRQ OF 120KT H3 JET MAX IN SE
ONTARIO WL BRING A RETURN OF POPS FM THE SW AFT 06Z...ESPECIALLY
OVER THE S HALF OF THE CWA. WL RETAIN SCHC FOR TS OVER THE SCNTRL
PER ECWMF/SREF FCST SSI NOT FAR ABOVE ZERO/CLOSER PROXIMITY TO WARM
FNT. BUT EXPECT A FAIRLY SHARP GRADIENT OF POPS TO THE N AS THE
ECMWF SHOWS VERY DRY AIR AT H7 OVER NRN LK SUP AND N H925 WINDS ON
THE SRN FLANK OF BLDG HI PRES IN SCNTRL CAN PUSHING DRIER AIR ACRS
THE LK.
SUN...ALTHOUGH THERE ARE SOME TIMING DIFFERENCES...THE SREF/ECMWF
INDICATE SOME LO/MID LVL DRYING ON SUN AS RRQ DYNAMICS EXIT WELL TO
THE NE OF SHRTWV/SFC LO IN THE CENTRAL PLAINS. SO REDUCED POPS A BIT
ARND MID DAY BEFORE THE LO PRES TO THE SW BEGINS TO MOVE NE AND
INCRS PCPN CHCS ESPECIALLY NEAR THE WI BORDER LATER IN THE DAY.
TENDED TOWARD THE LO END OF GUIDANCE FOR TEMPS GIVEN THE LLVL NLY
FLOW OFF THE CHILLY WATERS OF LK SUP SHOWN BY THE ECMWF.
SUN NGT...SHRTWV/SFC LO LIFTING NEWD OUT OF THE PLAINS ARE FCST TO
APRCH THE UPR LKS...WITH 12HR H5 FALLS FCST UP TO 120M ASSOCIATED
WITH VIGOROUS DEEP LYR QVECTOR CNVGC. ALTHOUGH THE ECMWF/SREF
INDICATE SOME DRY SLOTTING MAY IMPACT AT LEAST THE SCNTRL LATE...
ELEVATED POPS TO LIKELY GIVEN IMPRESSIVE DYNAMICS. PCPN SHOULD BE IN
THE FORM OF RA IN THE EVNG...BUT AS LLVL COLDER AIR IS DRAWN INTO
THE WRN ZNS...EXPECT THE COMBINATION OF THIS LLVL CAD AND DYNAMIC
COOLING TO BRING A WINTRY MIX. 12Z ECMWF FCST SDNGS AND FCST H100-85
THKNS FIELDS SUG THERE COULD BE A NARROW BAND OF FZRA WHERE THE LLVL
COLD AIR INFUSION IS SHALLOW AND IN THE ABSENCE OF ANY DIURNAL
HEATING LATE AT NGT. DEPENDING ON HOW QUICKLY DEEPER COLD AIR CAN
MOVE INTO THE W HALF...AT LEAST SEVERAL INCHES OF SNOW ARE PSBL IN
THAT AREA...ESPECIALLY WHERE THE LLVL CYC NNE FLOW WL UPSLOPE.
MON...AS THE SHRTWV BEGINS TO SHEAR TO THE NE ON THE NW FLANK OF UPR
RDG OVER THE SE CONUS AND INCOMING COLD AIR BEGINS TO CAUSE LARGER
SCALE QVECTOR DVGC...EXPECT PCPN SHIELD TO SLOWLY DECAY EVEN THOUGH
LINGERING CHILLY LLVL CYC NNE FLOW WL LINGER AND BRING ABOUT
CONTINUED PCPN CHCS ESPECIALLY OVER THE NW HALF. A FEW INCHES MORE
OF SN ARE PSBL OVER THE HIER TERRAIN OF THE NW HALF ON THE NW FLANK
OF THE H85 LO TRACK BEFORE THE PCPN DIMINISHES IN THE AFTN.
EXTENDED...A DRIER BUT CHILLY PATTERN WL DOMINATE TUE INTO EARLY WED
WITH HUDSON BAY HI PRES BLDG INTO ONTARIO. MORE PCPN IS PSBL ON WED
INTO THU AS ANOTHER PAIR OF DISTURBANCES ARE FCST TO IMPACT THE GREAT
LKS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 133 AM EDT FRI APR 13 2012
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD TONIGHT AND
FRIDAY AFTERNOON. CLOUDS WILL INCREASE SLOWLY AS A LOW PRESSURE
SYSTEM MAKES ITS WAY TOWARDS THE GREAT LAKES. THERE IS A CHANCE
SHOWERS AT KIWD AROUND 00Z SATURDAY AND THEN AT KCMX AND KSAW AFT
02Z. CIGS MAY LOWER TO MVFR AT KIWD AS SHOWERS MOVE ACROSS THE
AREA...BUT OTHERWISE CONFIDENCE IS NOT HIGH ENOUGH TO PUT
PREVAILING SHOWERS AT KCMX OR KSAW AS BEST FORCING WILL LIKELY STAY
TO THE WEST. FOR KCMX AND KSAW MENTIONED VCSH WITH A LOW VFR CIG
AROUND 5KFT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 453 AM EDT FRI APR 13 2012
SE WINDS WILL INCREASE TO 20-25 KT AS A TROUGH MOVES TOWARD THE UPPER
MS VALLEY. AS THE LOW MOVES TO THE NORTH OF THE AREA SATURDAY...20-25
KT WINDS WILL VEER TO THE SW.
EXPECT INCRSG NE WINDS TO AT LEAST APPROACH GALE FORCE ON SUN NIGHT
INTO MON ON THE NW FLANK OF LO PRES MOVING THRU THE GREAT LAKES AS
THE PRES GRADIENT SHARPENS BETWEEN THIS FEATURE AND HI PRES BUILDING
TOWARD NW ONTARIO. LIGHTER WINDS WILL ARRIVE ON MON NIGHT INTO TUE AS
HI PRES BUILDS OVER THE UPPER LKS. &&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...KC
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
357 AM CDT FRI APR 13 2012
.SHORT TERM...
ISSUED AT 353 AM CDT FRI APR 13 2012
(TODAY)
DIFFICULT PRECIPITATION FORECAST FOR TODAY...WHICH ALSO MAKES FOR A
DIFFICULT TEMPERATURE FORECAST. CURRENT RADAR HAS SCATTERED TO
NUMEROUS THUNDERSTORMS BREAKING OUT ALONG A LINE FROM JOPLIN TO
SEDALIA. THE STORMS ARE BEING FED BY A BROAD LOW LEVEL JET WITH
8-10C DEWPOINTS EMBEDDED IN IT. BROAD BUT SUBSTANTIAL MOISTURE
CONVERGENCE IS OCCURRING WHERE THE LOW LEVEL JET IS IMPACTING THE
WESTERN EDGE OF THE RIDGE OVER THE OHIO VALLEY. THE RUC HAS BEEN
CONSISTENTLY PUSHING THE AREA OF MOISTURE CONVERGENCE EAST THROUGH
THE MORNING. MESOSCALE MODELS INCLUDING THE NSSL 4KM WRF...THE NCEP
4KM WRF...OUR OWN LOCALLY RUN WRF...THE HRRR...AND THE EXPERIMENTAL
NARRE ALL SHOW THIS CONVECTION CONTINUING AS THE MOISTURE
CONVERGENCE SPREADS EAST. THE REAL QUESTION IS WHAT THE SOUTHERN
EXTENT WILL END UP BEING. THE HRRR AND THE VARIOUS HI RES WRFS
SPREAD RAIN OVER MOST OF THE CWFA WHILE OPERATIONAL MODELS SUCH AS
THE GFS AND NAM KEEP PRECIP CONFINED TO THE NORTHERN 2/3 OF THE
AREA. WITH PRECIP WELL INTO SOUTHERN MISSOURI AT THIS TIME...HAVE
DECIDED TO FOLLOW THE MORE WIDESPREAD SOLUTIONS OF THE MESOSCALE
MODELS AT THIS TIME. TEMPERATURES WILL DEPEND GREATLY ON CONVECTION
TODAY. STUCK PRETTY CLOSE TO A BLEND OF NAM/GFS MOS GUIDANCE.
CARNEY
&&
.LONG TERM...
ISSUED AT 353 AM CDT FRI APR 13 2012
(TONIGHT THROUGH THURSDAY)
IT APPEARS THERE WILL BE A LULL IN THE PRECIPITATION THIS EVENING
BEFORE THE NEXT ROUND OF SHOWERS AND THUNDERSTORMS GETS GOING LATE
THIS EVENING...AND MORE LIKELY OVERNIGHT. GUIDANCE IS IN GOOD
AGREEMENT SHOWING AN IMPULSE IN THE SW FLOW ALOFT TRACKING INTO
CENTRAL MO BETWEEN 06-12Z INTERACTING WITH A 30-40 KT SWLY LLJ
POSITIONED THRU THE CWA. THE MAIN QUESTION IS THE LOCATION WHERE
THE THUNDERSTORMS WILL ALIGN/FOCUS...WITH A RANGE OF SOLUTIONS
FROM ACROSS FAR NORTHERN MO TO JUST NORTH OF I-44. THE GREATEST
CONSENSUS IS THIS AXIS WILL BECOME ESTABLISHED FROM AROUND
COLUMBIA THROUGH BOWLING GREEN. SHOWERS AND THUNDERSTORMS WILL
GRADUALLY SHIFT TO THE EAST ON SATURDAY MORNING AND BELIEVE WILL
MOST OF THE ACTIVITY WILL HAVE EXITED THE CWA BY 18Z AS THE
IMPULSE MIGRATES TO THE NORTHEAST INTO CENTRAL IL. AFTERNOON
TEMPERATURES SHOULD RECOVER NICELY IN THE WAKE OF THE MORNING
CONVECTION AS CLOUDS DECREASE...WARMING INTO THE 70S.
THERE ISNT MUCH TO LATCH ONTO FOR POPS ON SATURDAY NIGHT. THE MOST
UNSTABLE AIR WILL RESIDE ACROSS THE NORTHERN PORTION OF THE CWA
WHILE A 50+ KT LLJ WILL REMAIN POSITIONED ACROSS THE AREA. ITS HARD
TO SAY IF THERE WILL BE A RESIDUAL OUTFLOW BOUNDARY FROM THE
CONVECTION EARLIER IN THE DAY. AND...THE MODELS FAIL TO DEPICT ANY
DISCERNABLE SURFACE BOUNDARIES OR DISTURBANCES ALOFT WHICH WOULD
HELP FOCUS CONVECTION. THUS WHILE I CAN`T RULE OUT
PRECIPITATION...ANY SHOWERS AND THUNDERSTORMS WOULD APPEAR TO HAVE
LIMITED ORGANIZATION AND BE MORE SPOTTY IN COVERAGE WITH THE
GREATEST PROBABILITY ACROSS NE MO INTO WEST CENTRAL IL IN PROXIMITY
TO THE GREATEST INSTABILITY.
IT APPEARS THE MAIN THRUST OF SHOWERS AND THUNDERSTORMS WILL BE ON
SUNDAY AFTERNOON AND EVENING AS THE MAIN UPPER TROF PROGRESSES INTO
THE MID MS VALLEY. DEEP LAYER SHEAR OF 60+ KTS WITHIN THE WARM
SECTOR AND MUCAPES OF 750-1500 J/KG SUGGEST A THREAT OF ORGANIZED
SEVERE STORMS WITH A MIXED MODE IN THE AFTERNOON TRANSITIONING TO
MORE LINEAR DURING THE EVENING. BELIEVE MOST OF THE PRECIPITATION
WILL HAVE EXITED TO THE EAST OF THE CWA ON MONDAY MORNING...WITH
DRIER AND COOLER AIR SPREADING ACROSS THE AREA IN THE WAKE OF THE
COLD FRONTAL PASSAGE.
GLASS
&&
.AVIATION...
ISSUED AT 1150 PM CDT THU APR 12 2012
BAND OF VERY LIGHT RAIN OVER NORTHEAST AND CENTRAL MISSOURI
CONTINUES TO DISSIPATE AS IT STRUGGLES TO MOVE EAST. DON`T
BELIEVE IT WILL HAVE AN IMPACT ON ANY TAF LOCATIONS THE REMAINDER
OF THE NIGHT...SO CONDITIONS FOR THE REST OF THE OVERNIGHT HOURS
SHOULD REMAIN VFR...AOA 5KFT. BELIEVE WE MAY BE SEEING THE VERY
EARLY STAGES OF OUR NEXT THREAT OF SIGNIFICANT PRECIP DEVELOPING
ATTM OVER E KS. 06Z TAF SET IS STICKING WITH MODEL CONSENSUS THAT
DEPICTS A N-S BAND OF SHOWERS AND ELEVATED TSRA DEVELOPING OVER E
KS/W MO DURING THE PREDAWN HOURS...WITH THIS ACTIVITY WORKING IN
MID MO BY AROUND 12Z AND TO NEAR THE MISSISSIPPI RIVER BY MID/LATE
MORNING. FORECAST SOUNDINGS ARE STILL SUGGESTING A LOWERING OF
CIGS AS THE OVERRUNNING/ISENTROPIC ASCENT PRODUCES SEVERAL HOURS
OF STEADY PRECIP. BECAUSE OF THIS TAF FORECASTS DEPICT OCCASIONAL
MVFR CIGS/VSBYS FOR DURING TIME OF HEAVIEST PRECIP. HAVE ALSO
ADDED A MENTION OF THUNDERSTORMS AT ALL TAF LOCATIONS AS A QUICK
PEEK AT THE 00Z RUNS IS SOMEWHAT MORE BULLISH WITH THE
INSTABILITY OVER THE AREA...ESPECIALLY IN CENTRAL MO. PRECIP
SHOULD EXIT E MO/SW IL BY EARLY AFTERNOON...WITH SCT-BKN VFR
CLOUDS 3-5KFT IN THE PRECIPS WAKE AND INTO FRIDAY EVENING. DETAILS
OF FRIDAY NIGHTS CONVECTION STILL FAIRLY MURKY...BUT ATTM IT WOULD
APPEAR THIS THREAT WILL BE AFTER 06Z/14.
SPECIFICS FOR KSTL...CIGS 5-8KFT SHOULD BE THE RULE UNTIL LATE
MORNING FRIDAY...WHEN SHOWERS AND EMBEDDED TSRA ARE EXPECTED TO
ADVECT INTO THE AREA FROM MID MO. ALTHOUGH BELIEVE VFR CONDITIONS
WILL BE THE DOMINATE FLIGHT CATEGORY DURING THE PRECIP...THE
AFOREMENTIONED SATURATION OF THE LOWER LEVELS SHOULD LEAD TO
OCCASIONAL MVFR CIGS/VSBYS FOR SEVERAL HOURS AFTER THE ONSET OF
THE RAIN. 00Z DATA IS JUST A BIT MORE BULLISH WITH THE INSTABILITY
INTO THE REGION...SO THIS TAF SET ALSO INCLUDES MENTION OF THUNDER
AROUND MIDDAY. ONCE RAIN MOVES OUT BY MID AFTERNOON EXPECT VFR
CIGS 3-5KFT...WITH THESE CONDITIONS PERSISTING INTO FRIDAY EVENING.
TRUETT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1159 PM CDT Thu Apr 12 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
Short Range (Tonight-Saturday)...
A large upper trough will continue to carve out space over the
western half of the U.S. Periodic shortwave energy will eject from
the base of the trough and combine with increasing moisture and
instability to generate several rounds of strong to severe
thunderstorms across KS/MO and areas to the southwest.
In the near term, a shortwave/vorticity max combo tracking ene
through eastern KS has generated several bands of elevated
convection. Short range convective models such as the HRRR handled
the associated convection/qpf best. Other models underplayed it
although they did a reasonably good job with the h5 vorticity
fields. Activity expected to gradually diminish as it pushes through
the upper level ridge and into drier downstream airmass.
Rest of forecast concerns center on how convective development will
be affected by the elevated mixed layer(EML) that is expected to
overspread the region tomorrow and Saturday. Lacking much of a
boundary to focus on believe this EML will prove to inhibit much of
the daytime convection on Friday and Saturday. Instead will focus on
the regeneration of the southerly low level jet over the Central
Plains both nights as the primary mechanism to initiate and maintain
nighttime convection. The first occurrence will be tonight and favor
using the 12z 4km NMM-WRF for tonights activity. An MCS is expected
to form over central/eastern NE/KS by mid evening and then roll
eastward as the low level jet veers to the southwest. The veering
allows the activity to maintain itself vs running ahead of the main
moisture source. Raised late night pops to categorical most areas.
Convection likely ongoing Friday morning but with it ending from
west to east as the EML begins to work in from the west. Conceptual
model then favors minimal if any convection so have toned down pops
for the rest of Friday/early Friday evening. Upstream redevelopment
convection may need the arrival of another shortwave and reformation
of the low level jet Friday evening. So, will again concentrate
highest pops for Friday night. Max temperatures will be tricky as
they will be greatly affected any residual cloud cover. Northeast MO
will likely be the coolest region.
Saturday should be similar to Friday in that the EML will be in
place and thus inhibit most of the convection. By Saturday a better
dryline may be in place over central KS and as a 110kt swly upper
level jet interacts with a 40kt+ southerly low level jet, expect a
squall-line of severe storms to erupt and advance eastward Saturday
evening. Severe weather could impact the western portion of the CWA
Saturday evening before it weakens. Inspection of NAM BUFR soundings
suggests that if clouds can break up many locations could challenge
the 80 degree mark.
MJ
Medium Range (Sunday through Thursday)...
Sunday...The main wave, in the form a closed upper low, associated
with the broad western CONUS trough will move into the Central
Plains. This will force a cold front into the area late in the day
on Sunday. There is much uncertainty as far as the potential for
severe weather due to ongoing showers that may be persisting across
the area in the morning and the residual cloud cover. 12Z NAM/GFS
Bufr soundings are showing only weak instability however if skies
clear, conditions could destabilize quickly with storms firing along
the cold front or along any remnant outflow boundaries from earlier
convection. This will need to be monitored further for severe
potential. Outside of the severe potential...flooding may also
become a concern over some locations as PWAT values on Sunday are
ranging from 1"-1.5". With periods of rainfall...possibly heavy in
some locations, expected Thursday night through Sunday morning and
additional heavy rain may lead to localized flooding as well as
flooding of small streams and creeks.
Monday - Thursday...We will see a pattern change as we move into the
beginning of next week. The amplified pattern that brought us
showers and thunderstorms through the weekend will become zonal
and thus tranquil. Temperatures on Monday and Tuesday will be
slightly below average with highs ranging from the mid 50s to mid
60s. Wednesday will feature a return to southerly flow out ahead of
a weak cold front. Temperatures will move to near normal with highs
in the 60s however that will be the next chance for showers across
the area as the cold front moves through the late Wednesday into
Wednesday night. By Thursday, high pressure moves back into the area
with highs moving above normal into the upper 60s to mid 70s.
73
&&
.AVIATION...
A few showers and thunderstorms moving across far eastern Kansas at the
moment. Given the isolated nature of the convection, will only
include VCTS for the first couple of hours. Thereafter, short range
guidance suggests the activity across central Kansas will expand and
shift eastward towards the terminals overnight. Rough timing brings
this into the TAF sites by around 09z. Can`t rule out some hail with
these storms as instability and deep layer shear increase coincident
with the arrival of the convection. Otherwise, winds will increase
overnight and become gusty. As the LLJ continues to shift eastward
tonight, LLWS will become a concern and have maintain mentioned until
sunrise.
Deroche
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS TOPEKA KS
609 AM CDT FRI APR 13 2012
...AVIATION UPDATE...
.DISCUSSION...
SEE PREV DISCUSSION.
&&
.AVIATION...
A SHORTWAVE CONTINUES TO LIFT NORTHEAST THROUGH EASTERN NEB. WITH
INCREASING SUBSIDENCE BEHIND THIS WAVE...THINK CONVECTION IS OVER
FOR THE REST OF TODAY. THERE DOES NOT APPEAR TO BE ANY ORGANIZED
FORCING FOR NEW CONVECTION UNTIL EARLY SATURDAY MORNING WHEN THE LOW
LEVEL JET NOSES INTO NORTHEAST KS WITH GOOD THETA-E ADVECTION AND
INCREASING ISENTROPIC LIFT. BECAUSE OF THIS INCLUDED A MENTION OF
VCTS LATE IN THE FORECAST PERIOD. OTHERWISE THE LATEST RUC AND NAM
SOUNDINGS ARE IN REASONABLE AGREEMENT IN MIXING OUT THE BOUNDARY
LAYER BETWEEN 17Z AND 19Z. THIS IS IN LINE WITH THE PREV FORECAST OF
SCATTERING OUT THE MVFR STRATUS.
WOLTERS
&&
.PREV DISCUSSION... /356 AM CDT FRI APR 13 2012/
ACTIVE WEATHER IS EXPECTED OVER THE NEXT 48 HOURS...WITH THE
POSSIBILITY OF SEVERE WEATHER TONIGHT...AND A SEVERE WEATHER
OUTBREAK ON SATURDAY AFTERNOON/NIGHT.
TODAY/TONIGHT...UPPER WAVE OBSERVED ON WATER VAPOR HELPING TO
SUPPORT ONGOING THUNDERSTORMS OVER EASTERN KANSAS AND THESE WILL
CONTINUE TO DEVELOP AND MOVE EASTWARD DURING THE EARLY MORNING
HOURS. EXPECT THUNDERSTORMS TO PERSIST OVER ONLY FAR EASTERN AREAS
BY SUNRISE. UPPER WAVE WILL MOVE INTO THE CENTRAL PLAINS THIS
MORNING...WITH SFC WINDS VEERING IN RESPONSE TO ASSOCIATED SFC LOW.
DRYLINE WILL LIKEWISE SHIFT/MIX EASTWARD. BY LATE AFTERNOON...THE
DRYLINE WILL ALIGN FROM HIAWATHA TO TOPEKA TO EMPORIA. WITH
SUBSIDENCE IN THE WAKE OF THIS MORNINGS SHORTWAVE TROUGH...AND ONLY
MARGINAL CONVERGENCE ALONG THE SFC BOUNDARY...CONVECTIVE INITIATION
REMAINS UNCERTAIN FOR THE CWA THIS AFTERNOON/EVENING. NEXT UPPER
WAVE APPROACHES THE HIGH PLAINS BY EARLY EVENING...AND SFC WINDS
WILL QUICKLY RESPOND AND BACK. THIS WILL EFFECTIVELY RETROGRADE THE
DRYLINE WESTWARD PRIOR TO 00Z FROM THE AFOREMENTIONED LOCATION.
CONVECTIVE DEVELOPMENT IS MORE PROBABLE BY LATE AFTERNOON INTO EARLY
EVENING IN AREAS SOUTHWEST OF THE CWA...SPECIFICALLY WESTERN
OKLAHOMA AND FAR SOUTH CENTRAL KANSAS...WHERE BETTER DRYLINE
CONVERGENCE/MIXING AND A CLOSER PROXIMITY TO INCREASING LARGE SCALE
ASCENT. A FEW STORMS MAY TRY TO DEVELOP ALONG THE RETREATING DRYLINE
OVER THE SOUTHWESTERN PORTION OF THE CWA AROUND SUNSET...BUT OVERALL
CONFIDENCE IN COVERAGE IS LOW ATTM. THE MORE LIKELY CONVECTIVE
SCENARIO FOR THE CWA WILL SPAWN FROM THE ANTICIPATED CONVECTION OVER
OKLAHOMA AND FAR SOUTHERN KANSAS. THIS ACTIVITY WILL MOVE
NORTHEASTWARD AND POSSIBLY EVOLVE INTO ONE OR MORE SMALL CLUSTERS.
BASED ON THIS SCENARIO AND THE OUTPUT FROM SEVERAL OPERATIONAL
MODELS...THE BEST CHANCE FOR THUNDERSTORMS WILL BE AFTER 9 PM CDT.
WITH THE EXPECTED EVOLUTION AND ANTICIPATED INSTABILITY LATE IN THE
EVENING...THE OVERALL SEVERE WEATHER THREAT MAY BE TEMPERED
SLIGHTLY. STILL...SEVERE WEATHER IS POSSIBLE ACROSS THE SOUTHERN
HALF OF THE CWA...GENERALLY ALONG AND SOUTH OF INTERSTATE 70. THE
PRIMARY SEVERE WEATHER THREAT WILL BE LARGE HAIL AND DAMAGING WINDS.
AS WITH ANY CONVECTIVE FORECAST...SUBTLE DETAILS REGARDING THE
COVERAGE...LOCATION AND TIMING OF CONVECTIVE INITIATION AND THE
SUBSEQUENT EVOLUTION COULD HAVE A SUBSTANTIAL IMPACT ON THE CURRENT
FORECAST...SO REMAIN ALERT TO RAPIDLY CHANGING WEATHER CONDITIONS
BEGINNING EARLY THIS EVENING INTO THE OVERNIGHT HOURS SATURDAY
MORNING.
SATURDAY/SATURDAY NIGHT...A MAJOR SEVERE WEATHER OUTBREAK IS
EXPECTED TO OCCUR BEGINNING LATE SAT AFTERNOON INTO THE OVERNIGHT
HOURS. A VERY DYNAMIC ENVIRONMENT WILL BE IN PLACE WITH STRONG
INSTABILITY AND IMPRESSIVE LOW LEVEL WIND SHEAR. STORMS THAT
DEVELOP...ESPECIALLY THOSE PRIOR TO MIDNIGHT SUNDAY...WILL HAVE A
GOOD LIKELIHOOD OF BECOMING SUPERCELLS. THESE STORMS WILL BE
CAPABLE OF PRODUCING VERY LARGE HAIL UP TO BASEBALL SIZE AND STRONG
TORNADOES. THE PRIMARY UNCERTAINTY REMAINS TIMING AND COVERAGE OF
CONVECTION ACROSS THE CWA...AND OPERATIONAL MODELS HAVE STRUGGLED
WITH RESOLVING CONVECTIVE OUTPUT. THE INITIAL THUNDERSTORMS WILL
LIKELY DEVELOP ALONG A DRYLINE OVER THE FAR WESTERN SECTIONS OF THE
CWA. ADDITIONAL STORMS MAY DEVELOP IN ADVANCE OF THIS BOUNDARY IN
THE WARM SECTOR AS THE ATMOSPHERE BECOMES UNCAPPED. STORMS ARE
EXPECTED TO PERSIST AND RETAIN MUCH OF THEIR ORGANIZATION AND
STRENGTH WELL AFTER DARK. WITH THE LOW LEVEL WIND FIELD INCREASING
NEAR/AFTER SUNSET...THE POSSIBILITY OF NIGHTTIME TORNADOES IS HIGH.
RESIDENTS ARE URGED TO PREPARE FOR THE POTENTIAL OF A WIDESPREAD
SEVERE WEATHER OUTBREAK...WHICH INCLUDES NIGHTTIME STRONG TORNADOES
SATURDAY NIGHT.
SUNDAY/BEYOND...THUNDERSTORMS WILL BE ONGOING OVER THE FAR EASTERN
SECTIONS OF THE CWA BY 12Z SUN. THE DRYLINE WILL QUICKLY EXIT THE
STATE PRIOR TO 18Z...ENDING THE SEVERE WEATHER THREAT FOR THE AREA.
DRY WEATHER IS CURRENTLY FORECASTED FOR THE REMAINDER OF THE
FORECAST PERIOD.
BLAIR
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
709 AM EDT FRI APR 13 2012
.SYNOPSIS...
ISSUED AT 453 AM EDT FRI APR 13 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH OVER
THE WRN CONUS AND A DOWNSTREAM RIDG FROM ERN TX INTO THE UPPER MS
VALLEY. A VIGOROUS SHORTWAVE TROUGH OVER WRN KS WAS LIFTING NE. AT
THE SFC...SE FLOW WAS INCREASING OVER MN AND WRN WI BTWN HIGH PRES
OVER LAKE HURON AND A TROUGH OVER THE PLAINS. IR LOOP SHOWED HIGH
CLOUDS EXPANDING INTO WRN UPPER MI ASSOCIATED WITH THE DEVELOPING
WAA PATTERN TO THE WEST.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 453 AM EDT FRI APR 13 2012
TODAY INTO TONIGHT...
HIGH AND MID CLOUDS WILL CONTINUE TO SPREAD INTO THE CWA. THE CLOUDS
SHOULD BE THIN ENOUGH TO ALLOW PLENTY OF SUNSHINE AND DECENT MIXING
ALONG WITH WAA TO PUSH TEMPS INTO UPPER 50S AND LOWER 60S. THIS
SHOULD ALSO KEEP DEWPOINTS IN THE LOWER 20S OVER MUCH OF THE
AREA...RESULTING IN RH VALUES IN THE 20 TO 25 PERCENT RANGE. THE DRY
AIR COMBINED WITH SOUTH WINDS OF 10 TO 20 MPH WILL LEAD TO ELEVATED
FIRE WX RISK. SO...WL CONTINUE TO HIGHLIGHT THE HAZARD WITH THE
WILDFIRE POTENTIAL STATEMENT.
MDLS SUGGEST THAT AS THE PLAINS SHRTWV LIFTS INTO THE UPPER MS
VALLEY AND WRN LAKE SUPERIOR...MODERATE 700-500 MB QVECTOR CONV...
WAA/ISENTROPIC LIFT ALONG WITH FAVORABLE MOISTURE TRANSPORT WILL
PRODUCE SCT/NMRS SHRA. MODELS CONTINUED WITH THE TREND TOWARD A
LATER ARRIVAL OF PCPN INTO THE WEST BUT THEN MOVE THE BAND QUICKLY THROUGH
THE WEST IN THE EVENING. EXPECT THE GREATEST PCPN COVERAGE/POPS OVER
THE NW HALF OF THE CWA...CLOSER TO THE PATH OF THE SHRTWV AND UPPER
LEVEL DIV WITH THE LEFT EXIT REGION OF THE 250-300 MB JET. SINCE THE
DYNAMICS MOVE INTO THE DRY AIRMASS FAIRLY QUICKLY ...ONLY LIGHT PCPN
AMOUNTS OF A TENTH OF AN INCH OR LESS ARE EXPECTED. WITH ELEVATED
CAPE REMAINING SOUTH OF THE AREA...PER NAM/GFS...NO TSRA ARE
EXPECTED. THE PCPN SHOULD DIMINISH OVER THE WEST BY LATE EVENING AND
OVER THE CENTRAL AND EAST AFTER MIDNIGHT.
SATURDAY...ANY LINGERING PCPN OVER THE ERN CWA SHOULD MOVE OUT EARLY
AS THE AREA FALLS UNDER THE DRY SLOT. 850 MB TEMPS TO AROUND 10C
ALONG WITH SUNSHINE SHOULD PUSH TEMPS TO AROUND 70.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 453 AM EDT FRI APR 13 2012
SAT NGT...AS FAIRLY POTENT SHRTWV BEGINS TO LIFT NEWD OUT OF THE SW
CONUS...SFC LO PRES IS FCST TO DVLP IN THE CENTRAL PLAINS. THE 00Z
GFS/NAM HAVE TRENDED TOWARD A DEEPER LO PRES FARTHER TO THE N THAN
THE 12Z ECMWF AND 00Z CNDN/UKMET. PER NCEP GUIDANCE...WL FOLLOW THE
SCENARIO CLOSER TO THE 12Z ECMWF/21Z SREF. THIS GUIDANCE SHOWS A
WEAK HI PRES RDG IN THE WAKE OF DISTURBANCE RESPONSIBLE FOR THE SAT
POPS BRINGING A BRIEF PERIOD OF DRY WX SAT EVNG. HOWEVER...APRCH OF
ATTENDANT WARM FNT AND UPR DVGC IN RRQ OF 120KT H3 JET MAX IN SE
ONTARIO WL BRING A RETURN OF POPS FM THE SW AFT 06Z...ESPECIALLY
OVER THE S HALF OF THE CWA. WL RETAIN SCHC FOR TS OVER THE SCNTRL
PER ECWMF/SREF FCST SSI NOT FAR ABOVE ZERO/CLOSER PROXIMITY TO WARM
FNT. BUT EXPECT A FAIRLY SHARP GRADIENT OF POPS TO THE N AS THE
ECMWF SHOWS VERY DRY AIR AT H7 OVER NRN LK SUP AND N H925 WINDS ON
THE SRN FLANK OF BLDG HI PRES IN SCNTRL CAN PUSHING DRIER AIR ACRS
THE LK.
SUN...ALTHOUGH THERE ARE SOME TIMING DIFFERENCES...THE SREF/ECMWF
INDICATE SOME LO/MID LVL DRYING ON SUN AS RRQ DYNAMICS EXIT WELL TO
THE NE OF SHRTWV/SFC LO IN THE CENTRAL PLAINS. SO REDUCED POPS A BIT
ARND MID DAY BEFORE THE LO PRES TO THE SW BEGINS TO MOVE NE AND
INCRS PCPN CHCS ESPECIALLY NEAR THE WI BORDER LATER IN THE DAY.
TENDED TOWARD THE LO END OF GUIDANCE FOR TEMPS GIVEN THE LLVL NLY
FLOW OFF THE CHILLY WATERS OF LK SUP SHOWN BY THE ECMWF.
SUN NGT...SHRTWV/SFC LO LIFTING NEWD OUT OF THE PLAINS ARE FCST TO
APRCH THE UPR LKS...WITH 12HR H5 FALLS FCST UP TO 120M ASSOCIATED
WITH VIGOROUS DEEP LYR QVECTOR CNVGC. ALTHOUGH THE ECMWF/SREF
INDICATE SOME DRY SLOTTING MAY IMPACT AT LEAST THE SCNTRL LATE...
ELEVATED POPS TO LIKELY GIVEN IMPRESSIVE DYNAMICS. PCPN SHOULD BE IN
THE FORM OF RA IN THE EVNG...BUT AS LLVL COLDER AIR IS DRAWN INTO
THE WRN ZNS...EXPECT THE COMBINATION OF THIS LLVL CAD AND DYNAMIC
COOLING TO BRING A WINTRY MIX. 12Z ECMWF FCST SDNGS AND FCST H100-85
THKNS FIELDS SUG THERE COULD BE A NARROW BAND OF FZRA WHERE THE LLVL
COLD AIR INFUSION IS SHALLOW AND IN THE ABSENCE OF ANY DIURNAL
HEATING LATE AT NGT. DEPENDING ON HOW QUICKLY DEEPER COLD AIR CAN
MOVE INTO THE W HALF...AT LEAST SEVERAL INCHES OF SNOW ARE PSBL IN
THAT AREA...ESPECIALLY WHERE THE LLVL CYC NNE FLOW WL UPSLOPE.
MON...AS THE SHRTWV BEGINS TO SHEAR TO THE NE ON THE NW FLANK OF UPR
RDG OVER THE SE CONUS AND INCOMING COLD AIR BEGINS TO CAUSE LARGER
SCALE QVECTOR DVGC...EXPECT PCPN SHIELD TO SLOWLY DECAY EVEN THOUGH
LINGERING CHILLY LLVL CYC NNE FLOW WL LINGER AND BRING ABOUT
CONTINUED PCPN CHCS ESPECIALLY OVER THE NW HALF. A FEW INCHES MORE
OF SN ARE PSBL OVER THE HIER TERRAIN OF THE NW HALF ON THE NW FLANK
OF THE H85 LO TRACK BEFORE THE PCPN DIMINISHES IN THE AFTN.
EXTENDED...A DRIER BUT CHILLY PATTERN WL DOMINATE TUE INTO EARLY WED
WITH HUDSON BAY HI PRES BLDG INTO ONTARIO. MORE PCPN IS PSBL ON WED
INTO THU AS ANOTHER PAIR OF DISTURBANCES ARE FCST TO IMPACT THE GREAT
LKS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 708 AM EDT FRI APR 13 2012
VFR CONDITIONS WILL PREVAIL THROUGH TODAY. CLOUDS WILL INCREASE
SLOWLY AS A LOW PRESSURE SYSTEM MAKES ITS WAY TOWARDS THE GREAT
LAKES. THERE IS A CHANCE SHOWERS AT KIWD AROUND 00Z SATURDAY AND
THEN AT KCMX AND KSAW AFT 02Z. CIGS MAY LOWER TO MVFR AS LOW LEVEL
MOISTURE INCREASE BEHIND THE BAND OF SCATTERED SHOWERS MOVING
THROUGH THE AREA.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 453 AM EDT FRI APR 13 2012
SE WINDS WILL INCREASE TO 20-25 KT AS A TROUGH MOVES TOWARD THE UPPER
MS VALLEY. AS THE LOW MOVES TO THE NORTH OF THE AREA SATURDAY...20-25
KT WINDS WILL VEER TO THE SW.
EXPECT INCRSG NE WINDS TO AT LEAST APPROACH GALE FORCE ON SUN NIGHT
INTO MON ON THE NW FLANK OF LO PRES MOVING THRU THE GREAT LAKES AS
THE PRES GRADIENT SHARPENS BETWEEN THIS FEATURE AND HI PRES BUILDING
TOWARD NW ONTARIO. LIGHTER WINDS WILL ARRIVE ON MON NIGHT INTO TUE AS
HI PRES BUILDS OVER THE UPPER LKS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...KC
AVIATION...JLB
MARINE...KC
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1015 AM CDT FRI APR 13 2012
.UPDATE...
ISSUED AT 1015 AM CDT FRI APR 13 2012
SLUG OF RAIN AND IMBEDDED TSRA IS MOVING THRU THE FA ATTM N OF A
WRMFNT...AND IS MOVING RATHER SLOWLY AND IS BACKBUILDING A BIT. THIS
AREA OF RAIN IS CARRYING WITH IT A SIZABLE AREA OF RAIN-COOLED AIR
WITH TEMPS IN THE UPR 40S. LOOK FOR THE RAIN TO BEGIN TO EXIT
CNTRL MO BTWN 11A-12P...WHILE NOT GETTING OUT OF AREAS NEAR THE MS
RIVER UNTIL BETWEEN 2 AND 4 PM. MORE SPECIFICALLY...STL CITY
SHOULD BE UNDER THE THREAT OF STEADY RAIN UNTIL AROUND 3 PM.
TEMPS WILL BE A CHALLENGE AND ALREADY TOOK THE AXE TO SEVERAL
AREAS WITH THICK CLOUD COVER EXPECTED THRU MOST OF THE DAY AND A
WRMFNT THAT WILL BE KEPT AT BAY. WILL STRUGGLE TO EXIT THE 50S FOR
MOST LOCATIONS...ALTHOUGH CNTRL MO WITH THE RAIN EXITING SOONER
AND SOME SUN EXPECTED AND PROXIMITY OF WRMFNT SHOULD ALLOW THEM TO
RECOVER INTO THE 60S.
TEMPS SHOULD BE NEAR STEADY IF NOT RISE SLOWLY OVERNIGHT AS
WRMFNT FINALLY MAKES ITS PUSH THRU THE FA.
TES
&&
.SHORT TERM...
ISSUED AT 353 AM CDT FRI APR 13 2012
(TODAY)
DIFFICULT PRECIPITATION FORECAST FOR TODAY...WHICH ALSO MAKES FOR A
DIFFICULT TEMPERATURE FORECAST. CURRENT RADAR HAS SCATTERED TO
NUMEROUS THUNDERSTORMS BREAKING OUT ALONG A LINE FROM JOPLIN TO
SEDALIA. THE STORMS ARE BEING FED BY A BROAD LOW LEVEL JET WITH
8-10C DEWPOINTS EMBEDDED IN IT. BROAD BUT SUBSTANTIAL MOISTURE
CONVERGENCE IS OCCURRING WHERE THE LOW LEVEL JET IS IMPACTING THE
WESTERN EDGE OF THE RIDGE OVER THE OHIO VALLEY. THE RUC HAS BEEN
CONSISTENTLY PUSHING THE AREA OF MOISTURE CONVERGENCE EAST THROUGH
THE MORNING. MESOSCALE MODELS INCLUDING THE NSSL 4KM WRF...THE NCEP
4KM WRF...OUR OWN LOCALLY RUN WRF...THE HRRR...AND THE EXPERIMENTAL
NARRE ALL SHOW THIS CONVECTION CONTINUING AS THE MOISTURE
CONVERGENCE SPREADS EAST. THE REAL QUESTION IS WHAT THE SOUTHERN
EXTENT WILL END UP BEING. THE HRRR AND THE VARIOUS HI RES WRFS
SPREAD RAIN OVER MOST OF THE CWFA WHILE OPERATIONAL MODELS SUCH AS
THE GFS AND NAM KEEP PRECIP CONFINED TO THE NORTHERN 2/3 OF THE
AREA. WITH PRECIP WELL INTO SOUTHERN MISSOURI AT THIS TIME...HAVE
DECIDED TO FOLLOW THE MORE WIDESPREAD SOLUTIONS OF THE MESOSCALE
MODELS AT THIS TIME. TEMPERATURES WILL DEPEND GREATLY ON CONVECTION
TODAY. STUCK PRETTY CLOSE TO A BLEND OF NAM/GFS MOS GUIDANCE.
CARNEY
&&
.LONG TERM...
ISSUED AT 353 AM CDT FRI APR 13 2012
(TONIGHT THROUGH THURSDAY)
IT APPEARS THERE WILL BE A LULL IN THE PRECIPITATION THIS EVENING
BEFORE THE NEXT ROUND OF SHOWERS AND THUNDERSTORMS GETS GOING LATE
THIS EVENING...AND MORE LIKELY OVERNIGHT. GUIDANCE IS IN GOOD
AGREEMENT SHOWING AN IMPULSE IN THE SW FLOW ALOFT TRACKING INTO
CENTRAL MO BETWEEN 06-12Z INTERACTING WITH A 30-40 KT SWLY LLJ
POSITIONED THRU THE CWA. THE MAIN QUESTION IS THE LOCATION WHERE
THE THUNDERSTORMS WILL ALIGN/FOCUS...WITH A RANGE OF SOLUTIONS
FROM ACROSS FAR NORTHERN MO TO JUST NORTH OF I-44. THE GREATEST
CONSENSUS IS THIS AXIS WILL BECOME ESTABLISHED FROM AROUND
COLUMBIA THROUGH BOWLING GREEN. SHOWERS AND THUNDERSTORMS WILL
GRADUALLY SHIFT TO THE EAST ON SATURDAY MORNING AND BELIEVE WILL
MOST OF THE ACTIVITY WILL HAVE EXITED THE CWA BY 18Z AS THE
IMPULSE MIGRATES TO THE NORTHEAST INTO CENTRAL IL. AFTERNOON
TEMPERATURES SHOULD RECOVER NICELY IN THE WAKE OF THE MORNING
CONVECTION AS CLOUDS DECREASE...WARMING INTO THE 70S.
THERE ISNT MUCH TO LATCH ONTO FOR POPS ON SATURDAY NIGHT. THE MOST
UNSTABLE AIR WILL RESIDE ACROSS THE NORTHERN PORTION OF THE CWA
WHILE A 50+ KT LLJ WILL REMAIN POSITIONED ACROSS THE AREA. ITS HARD
TO SAY IF THERE WILL BE A RESIDUAL OUTFLOW BOUNDARY FROM THE
CONVECTION EARLIER IN THE DAY. AND...THE MODELS FAIL TO DEPICT ANY
DISCERNABLE SURFACE BOUNDARIES OR DISTURBANCES ALOFT WHICH WOULD
HELP FOCUS CONVECTION. THUS WHILE I CAN`T RULE OUT
PRECIPITATION...ANY SHOWERS AND THUNDERSTORMS WOULD APPEAR TO HAVE
LIMITED ORGANIZATION AND BE MORE SPOTTY IN COVERAGE WITH THE
GREATEST PROBABILITY ACROSS NE MO INTO WEST CENTRAL IL IN PROXIMITY
TO THE GREATEST INSTABILITY.
IT APPEARS THE MAIN THRUST OF SHOWERS AND THUNDERSTORMS WILL BE ON
SUNDAY AFTERNOON AND EVENING AS THE MAIN UPPER TROF PROGRESSES INTO
THE MID MS VALLEY. DEEP LAYER SHEAR OF 60+ KTS WITHIN THE WARM
SECTOR AND MUCAPES OF 750-1500 J/KG SUGGEST A THREAT OF ORGANIZED
SEVERE STORMS WITH A MIXED MODE IN THE AFTERNOON TRANSITIONING TO
MORE LINEAR DURING THE EVENING. BELIEVE MOST OF THE PRECIPITATION
WILL HAVE EXITED TO THE EAST OF THE CWA ON MONDAY MORNING...WITH
DRIER AND COOLER AIR SPREADING ACROSS THE AREA IN THE WAKE OF THE
COLD FRONTAL PASSAGE.
GLASS
&&
.AVIATION...
ISSUED AT 624 AM CDT FRI APR 13 2012
AREA OF SHOWERS AND THUNDERSTORMS OVER WESTERN AND CENTRAL MISSOURI
WILL OVERSPREAD EASTERN MISSOURI AND SOUTHWEST ILLINOIS. WHILE VFR
FLIGHT CONDITIONS WILL PREVAIL...THERE WILL BE AREAS OF MVFR AND
EVEN IFR IN THE HEAVIEST STORMS. STORMS SHOULD CLEAR THE BI-STATE
REGION BY MID AFTERNOON. THE NEXT ROUND OF THUNDERSTORMS IS
EXPECTED TO DEVELOP OVER CENTRAL MISSOURI DURING THE LATE EVENING
OR JUST AFTER MIDNIGHT AND AFFECT MUCH OF THE AREA ALONG AND NORTH
OF I-70. TIMING AND AREAL COVERAGE OF THESE STORMS IS STILL
UNCERTAIN AT THIS TIME.
SPECIFICS FOR KSTL...
SHOWERS AND THUNDERSTORMS WILL MOVE INTO THE TERMINAL FROM THE
WEST THIS MORNING AND THERE WILL LIKELY BE PRECIPITATION IN THE
VICINITY AT LEAST THROUGH 18Z. THAT BEING SAID...THINK VFR FLIGHT
CONDITIONS WILL PREVAIL EXCEPT IF A STRONG THUNDERSTORM MOVES
DIRECTLY OVER THE TERMINAL. ONCE THE RAIN ENDS THERE SHOULD BE A
QUIET PERIOD UNTIL LATE TONIGHT. ANOTHER ROUND OF STORMS WILL
DEVELOP DURING THE PRE-DAWN HOURS ON SATURDAY. TIMING AND AREAL
COVERAGE OF THESE STORMS IS STILL UNCERTAIN...HOWEVER CURRENT
THINKING IS THE STRONGEST STORMS WILL STAY NORTH OF THE TERMINAL.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
640 AM CDT FRI APR 13 2012
.SHORT TERM...
ISSUED AT 353 AM CDT FRI APR 13 2012
(TODAY)
DIFFICULT PRECIPITATION FORECAST FOR TODAY...WHICH ALSO MAKES FOR A
DIFFICULT TEMPERATURE FORECAST. CURRENT RADAR HAS SCATTERED TO
NUMEROUS THUNDERSTORMS BREAKING OUT ALONG A LINE FROM JOPLIN TO
SEDALIA. THE STORMS ARE BEING FED BY A BROAD LOW LEVEL JET WITH
8-10C DEWPOINTS EMBEDDED IN IT. BROAD BUT SUBSTANTIAL MOISTURE
CONVERGENCE IS OCCURRING WHERE THE LOW LEVEL JET IS IMPACTING THE
WESTERN EDGE OF THE RIDGE OVER THE OHIO VALLEY. THE RUC HAS BEEN
CONSISTENTLY PUSHING THE AREA OF MOISTURE CONVERGENCE EAST THROUGH
THE MORNING. MESOSCALE MODELS INCLUDING THE NSSL 4KM WRF...THE NCEP
4KM WRF...OUR OWN LOCALLY RUN WRF...THE HRRR...AND THE EXPERIMENTAL
NARRE ALL SHOW THIS CONVECTION CONTINUING AS THE MOISTURE
CONVERGENCE SPREADS EAST. THE REAL QUESTION IS WHAT THE SOUTHERN
EXTENT WILL END UP BEING. THE HRRR AND THE VARIOUS HI RES WRFS
SPREAD RAIN OVER MOST OF THE CWFA WHILE OPERATIONAL MODELS SUCH AS
THE GFS AND NAM KEEP PRECIP CONFINED TO THE NORTHERN 2/3 OF THE
AREA. WITH PRECIP WELL INTO SOUTHERN MISSOURI AT THIS TIME...HAVE
DECIDED TO FOLLOW THE MORE WIDESPREAD SOLUTIONS OF THE MESOSCALE
MODELS AT THIS TIME. TEMPERATURES WILL DEPEND GREATLY ON CONVECTION
TODAY. STUCK PRETTY CLOSE TO A BLEND OF NAM/GFS MOS GUIDANCE.
CARNEY
&&
.LONG TERM...
ISSUED AT 353 AM CDT FRI APR 13 2012
(TONIGHT THROUGH THURSDAY)
IT APPEARS THERE WILL BE A LULL IN THE PRECIPITATION THIS EVENING
BEFORE THE NEXT ROUND OF SHOWERS AND THUNDERSTORMS GETS GOING LATE
THIS EVENING...AND MORE LIKELY OVERNIGHT. GUIDANCE IS IN GOOD
AGREEMENT SHOWING AN IMPULSE IN THE SW FLOW ALOFT TRACKING INTO
CENTRAL MO BETWEEN 06-12Z INTERACTING WITH A 30-40 KT SWLY LLJ
POSITIONED THRU THE CWA. THE MAIN QUESTION IS THE LOCATION WHERE
THE THUNDERSTORMS WILL ALIGN/FOCUS...WITH A RANGE OF SOLUTIONS
FROM ACROSS FAR NORTHERN MO TO JUST NORTH OF I-44. THE GREATEST
CONSENSUS IS THIS AXIS WILL BECOME ESTABLISHED FROM AROUND
COLUMBIA THROUGH BOWLING GREEN. SHOWERS AND THUNDERSTORMS WILL
GRADUALLY SHIFT TO THE EAST ON SATURDAY MORNING AND BELIEVE WILL
MOST OF THE ACTIVITY WILL HAVE EXITED THE CWA BY 18Z AS THE
IMPULSE MIGRATES TO THE NORTHEAST INTO CENTRAL IL. AFTERNOON
TEMPERATURES SHOULD RECOVER NICELY IN THE WAKE OF THE MORNING
CONVECTION AS CLOUDS DECREASE...WARMING INTO THE 70S.
THERE ISNT MUCH TO LATCH ONTO FOR POPS ON SATURDAY NIGHT. THE MOST
UNSTABLE AIR WILL RESIDE ACROSS THE NORTHERN PORTION OF THE CWA
WHILE A 50+ KT LLJ WILL REMAIN POSITIONED ACROSS THE AREA. ITS HARD
TO SAY IF THERE WILL BE A RESIDUAL OUTFLOW BOUNDARY FROM THE
CONVECTION EARLIER IN THE DAY. AND...THE MODELS FAIL TO DEPICT ANY
DISCERNABLE SURFACE BOUNDARIES OR DISTURBANCES ALOFT WHICH WOULD
HELP FOCUS CONVECTION. THUS WHILE I CAN`T RULE OUT
PRECIPITATION...ANY SHOWERS AND THUNDERSTORMS WOULD APPEAR TO HAVE
LIMITED ORGANIZATION AND BE MORE SPOTTY IN COVERAGE WITH THE
GREATEST PROBABILITY ACROSS NE MO INTO WEST CENTRAL IL IN PROXIMITY
TO THE GREATEST INSTABILITY.
IT APPEARS THE MAIN THRUST OF SHOWERS AND THUNDERSTORMS WILL BE ON
SUNDAY AFTERNOON AND EVENING AS THE MAIN UPPER TROF PROGRESSES INTO
THE MID MS VALLEY. DEEP LAYER SHEAR OF 60+ KTS WITHIN THE WARM
SECTOR AND MUCAPES OF 750-1500 J/KG SUGGEST A THREAT OF ORGANIZED
SEVERE STORMS WITH A MIXED MODE IN THE AFTERNOON TRANSITIONING TO
MORE LINEAR DURING THE EVENING. BELIEVE MOST OF THE PRECIPITATION
WILL HAVE EXITED TO THE EAST OF THE CWA ON MONDAY MORNING...WITH
DRIER AND COOLER AIR SPREADING ACROSS THE AREA IN THE WAKE OF THE
COLD FRONTAL PASSAGE.
GLASS
&&
.AVIATION...
ISSUED AT 624 AM CDT FRI APR 13 2012
AREA OF SHOWERS AND THUNDERSTORMS OVER WESTERN AND CENTRAL MISSOURI
WILL OVERSPREAD EASTERN MISSOURI AND SOUTHWEST ILLINOIS. WHILE VFR
FLIGHT CONDITIONS WILL PREVAIL...THERE WILL BE AREAS OF MVFR AND
EVEN IFR IN THE HEAVIEST STORMS. STORMS SHOULD CLEAR THE BI-STATE
REGION BY MID AFTERNOON. THE NEXT ROUND OF THUNDERSTORMS IS
EXPECTED TO DEVELOP OVER CENTRAL MISSOURI DURING THE LATE EVENING
OR JUST AFTER MIDNIGHT AND AFFECT MUCH OF THE AREA ALONG AND NORTH
OF I-70. TIMING AND AREAL COVERAGE OF THESE STORMS IS STILL
UNCERTAIN AT THIS TIME.
SPECIFICS FOR KSTL...
SHOWERS AND THUNDERSTORMS WILL MOVE INTO THE TERMINAL FROM THE
WEST THIS MORNING AND THERE WILL LIKELY BE PRECIPITATION IN THE
VICINITY AT LEAST THROUGH 18Z. THAT BEING SAID...THINK VFR FLIGHT
CONDITIONS WILL PREVAIL EXCEPT IF A STRONG THUNDERSTORM MOVES
DIRECTLY OVER THE TERMINAL. ONCE THE RAIN ENDS THERE SHOULD BE A
QUIET PERIOD UNTIL LATE TONIGHT. ANOTHER ROUND OF STORMS WILL
DEVELOP DURING THE PRE-DAWN HOURS ON SATURDAY. TIMING AND AREAL
COVERAGE OF THESE STORMS IS STILL UNCERTAIN...HOWEVER CURRENT
THINKING IS THE STRONGEST STORMS WILL STAY NORTH OF THE TERMINAL.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
904 AM MDT FRI APR 13 2012
.UPDATE...A WEAK SHORT-WAVE RIDGE OVER THE CWA THIS MORNING HAS
ALLOWED FOR CLEARING SKIES AS A VIGOROUS SHORT-WAVE TROUGH WAS
JUST EAST OF THE CWA...TAKING PRECIPITATION WITH IT. A SLOW-MOVING
LOW-AMPLITUDE SHORT-WAVE TROUGH WAS OVER SWRN WY...WITH STEEP
LAPSE RATES AND FAIRLY DEEP MOISTURE AHEAD OF IT PER THE 12Z KRIW
SOUNDING. AS THIS TROUGH DRIFTS SLOWLY NORTHEAST IT WILL SPREAD
ISOLD-SCT SHOWERS OVER NERN WY AND FAR SWRN SD THROUGH THE AFTN.
HOWEVER...A RELATIVELY DRY BOUNDARY LAYER OVER WRN SD WILL LIMIT
THE COVERAGE AND ERN EXTENT OF THE SHOWERS. OUR LOCAL WRF-ARW RUN
SUPPORTS THIS...BUT THE 12Z HRRR IS MUCH MORE AGGRESSIVE WITH
AFTN SHOWERS...WHICH IS INCONSISTENT WITH THE RELATIVELY DRY
BOUNDARY LAYER.
&&
.PREV DISCUSSION... /ISSUED 327 AM MDT FRI APR 13 2012/
DISCUSSION...
LONG WAVE RIDGE EXTENDS FROM MN TO LA WITH STRONG LONG WAVE TROF
NEAR THE WEST COAST. ONE STRONG SHORT WAVE EXTENDS FROM CNTRL MT
TO THE NE PANHANDLE WITH A SECOND STRONG SHORT WAVE MOVING INTO
THE LONG WAVE TROF ON THE WEST COAST THIS EVENING. WHILE THE FIRST
SHORT WAVE IS FCST TO MOVE QUICKLY NE WARD... THE SECOND MOVES TO
NV BY 12Z SAT AND THEN NE WARD WITH SIGNIFICANT IMPACT ON OUR CWFA.
AS THE SHORT WAVE APPROACHES...SFC CYCLOGENESIS IS FCST OVER CO.
THE LOW MOVES TO NORTH EAST NE BY 12Z SUN WITH A LARGE AREA OF
500MB Q VECTOR CONVERGENCE GIVING SUPPORT FOR PRECIP NORTH OF THE
LOW CENTER. UPPER SUPPORT FOR ASCENT AR IVES OVER OUR AREA BY 12Z
SAT WELL IN ADVANCE OF THE STRONG SHORT WAVE AND SFC CYCLOGENESIS. THE
700 MB LOW IS FCST TO MOVE NE WARD ACROSS THE SE PORTION OF OUR
CWA ON A TRACK THAT WOULD BE IDEAL FOR HEAVY SNOW IF TEMPS WERE A
BIT COLDER.
EARLIER CONVECTION THAT FORMED OVER WRN SD THIS AFTERNOON HAS
MOVED E WARD OUT OF THE CWFA. A WEAK AREA OF Q VECTOR CONVERGENCE
IS FCST TO MOVE QUICKLY OVER THE SRN PORTIONS OF THE CWFA THIS
MORNING GIVING A SLIGHT CHANCE FOR SHOWERS. MORE WIDESPREAD PRECIP
IS FCST TO DEVELOP OVER THE SRN PORTIONS OF OUR AREA WITH LARGE
SCALE ASCENT ON SATURDAY MORNING CONTINUING INTO SUNDAY. SOME
SNOW IS LIKELY OVER THE HIGHER ELEVATIONS OF THE BLACK HILLS.
MODELS ARE NOT IN GOOD AGREEMENT THIS MORNING AS TO HOW MUCH...WE
HAVE ABOUT 2 INCHES MAX IN PRESENT FCSTS. UNCERTAINTY ABOUT BOTH
PRECIP AMOUNTS AND TEMPS PREVENTS A FORECAST OF HIGHER
AMOUNTS AT THIS TIME...BUT THEY ARE POSSIBLE.
TEMPS PRETTY MUCH IN LINE WITH MAV AND MET GUIDANCE.
EXTENDED...A SERIES OF WEAK WAVES IN WESTERLY FLOW ALOFT WILL BRING
JUST A SLIGHT CHANCE OF SHOWERS TO VARIOUS PARTS OF THE AREA FROM
MONDAY THROUGH THURSDAY. EXTENDED MODELS DIFFER ON THE TIMING OF THE
WAVES SO WILL CONTINUE WITH A BLENDED SOLUTION FOR NOW. HIGH
TEMPERATURES WILL BE ONLY SLIGHTLY COOLER THAN NORMAL ON MONDAY...IN
THE UPPER 40S TO THE MID 50S ON THE PLAINS...WARMING INTO THE LOWER
60S TO LOWER 70S FOR WEDNESDAY AND THURSDAY.
AVIATION...12Z TAF FORECAST
MVFR CIGS WILL BE FOUND OVER PARTS OF SOUTH CENTRAL SOUTH DAKOTA
THROUGH ABOUT 16Z...THEN VFR CONDITIONS WILL PREVAIL ACROSS THE
FORECAST AREA THROUGH THE REST OF TODAY AND TONIGHT. ISOLD TO SCT
RAIN SHOWERS ARE POSSIBLE TODAY AND TONIGHT. THE BETTER CHANCES OF
SHOWERS WILL BE OVER NORTHEASTERN WYOMING AND THE BLACK HILLS AREA
THIS AFTERNOON.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...BUNKERS
LONG TERM....01
AVIATION...01
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
1038 AM PDT FRI APR 13 2012
.SYNOPSIS...
RAIN SHOWERS AND MOUNTAIN SNOW EXPECTED TODAY WITH AN ADDITIONAL
CHANCE OF VALLEY AND FOOTHILL THUNDERSTORMS THIS AFTERNOON.
THUNDERSTORMS MAY BECOME SEVERE WITH HAIL, STRONG WINDS, DANGEROUS
LIGHTNING, AND HEAVY DOWNPOURS THE MAIN THREATS. THE STORM SYSTEM IS
FORECAST TO MOVE OUT BY LATE TONIGHT. HIGH PRESSURE WILL MOVE IN
THIS WEEKEND BRINGING DRY CONDITIONS AND WARMER TEMPERATURES
THROUGH THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...UPPER LOW IS POSITIONED OFF THE NORCAL COAST THIS
MORNING AND BEGINNING TO DIG SOUTHEAST AS 125 KT UPPER JET ROUNDS
THE BASE. FRONTAL BAND PUSHED INTO THE DISTRICT OVERNIGHT WITH
BRIEF PERIODS OF MODERATE TO HEAVY RAINFALL ACROSS THE CENTRAL
AND SOUTHERN SAN JOAQUIN VALLEY. AUTOMATED GAUGES HAVE GENERALLY
MEASURED FROM A HALF TO ONE INCH RAIN IN THE SJ VALLEY THUS FAR.
PARTS OF THE SOUTHERN SIERRA NEVADA AND FOOTHILLS HAVE SEEN OVER
AN INCH. SNOW LEVEL THIS MORNING IS AT 4000 FEET AROUND YOSEMITE
WITH SNOW DOWN TO AROUND 5000 FEET IN THE TEHACHAPI MOUNTAINS.
WINTER STORM WARNINGS REMAIN IN EFFECT FOR BOTH THE SOUTHERN
SIERRA AND THE KERN COUNTY MOUNTAINS. FOCUS ONCE AGAIN THIS
AFTERNOON WILL BE ON CONVECTION AS THE COLD POOL ALOFT MOVES
OVERHEAD WITH THE POTENTIAL FOR SEVERE THUNDERSTORMS. 12Z NAM HAS
H5 TEMPS OF -31 DEG C ALONG WITH CAPE ~500 J/KG AND LI OF -1.
LATEST RUC SOUNDINGS SHOW CAPE APPROACHING 1000 J/KG AND LI OF -5.
WHILE THIS MAY BE A BIT OVERDONE...IT CERTAINLY LOOKS UNSTABLE
ENOUGH THIS AFTERNOON...ESPECIALLY IF THERE IS SOME CLEARING IN
THE CLOUD SHIELD. THINGS WILL BEGIN TO TAPER OFF TONIGHT AS THE
LOW SHIFTS EAST BUT OROGRAPHICS WILL LIKELY KEEP SOME SHOWERS
GOING ACROSS THE MOUNTAINS OVERNIGHT. THE LOW WILL REACH THE FOUR
CORNERS REGION ON SATURDAY WITH STILL A FEW LINGERING SHOWERS
POSSIBLE FOR THE MOUNTAINS DUE TO WRAP AROUND MOISTURE. AN EPAC
UPPER RIDGE WILL BUILD IN BEHIND THE LOW BRINGING DRY WEATHER AND
A WARMING TREND INTO NEXT WEEK. THE RIDGE WILL FLATTEN OUT NEXT
WEEK BUT THE WESTERLIES KEEP THE STORM TRACK TO OUR NORTH.
&&
.PREV DISCUSSION... /ISSUED 442 AM PDT FRI APR 13 2012/
DISCUSSION...
AN APPROACHING FRONTAL SYSTEM CONTINUES TO PUSH INTO THE
CALIFORNIA COAST THIS MORNING AND THE PRECIPITATION AREA IN
ADVANCE OF THE INCOMING FRONT HAS FILLED IN ACROSS MUCH OF THE
CENTRAL CALIFORNIA INTERIOR DURING THE OVERNIGHT HOURS. THIS COLD
UNSTABLE SYSTEM WILL BE ACCOMPANIED BY A SIGNIFICANT UPPER LEVEL
JET MAX AND IS EXPECTED TO TRIGGER ANOTHER ROUND OF POSSIBLY
STRONG CONVECTIVE ACTIVITY ACROSS OUR AREA TODAY...ACCOMPANIED BY
SOME MORE SMALL AND EVEN SOME NOT SO SMALL HAIL. THE CURRENTLY
OCCURRING SHOWERS HAVE ALREADY BEEN PRODUCING OCCASIONAL LIGHTNING
STRIKES OVERNIGHT. THE FORECAST FOR A COOL...WET AND STORMY FRIDAY
THE 13TH ACROSS OUR AREA IS ON TRACK...WITH SIGNIFICANT SNOWFALL
ACCUMULATIONS IN THE HIGHER ELEVATIONS,,,AND EVEN A COUPLE OF
INCHES POSSIBLE AT PASS LEVELS IN KERN COUNTY BY TONIGHT INTO
SATURDAY AS SNOW LEVELS DROP A BIT BELOW 4000 FEET. WINTER STORM
WARNINGS REMAIN IN EFFECT FOR THE MOUNTAINS...AS WELL AS A WIND
ADVISORY FOR THE DESERTS...AS THE STORM SYSTEM BLOWS THROUGH TODAY
AND TONIGHT.
BY SATURDAY...AS THE SYSTEM PULLS OUT OF THE AREA...DRYER CONDITIONS
WILL SET IN WITH JUST SOME LINGERING MOUNTAIN SHOWERS. TEMPERATURES
WILL BEGIN A WARMING TREND...RECOVERING TO AROUND 10 DEGREES BELOW
CLIMO TOMORROW...AFTER TOPPING OUT AS MUCH AS 15-20 DEGREES BELOW
NORMAL TODAY. THE DRY AND WARMING TREND WILL CONTINUE THROUGH EARLY
NEXT WEEK AS HIGH PRESSURE BUILDS INTO THE REGION. TEMPERATURES
WILL BE BACK TO SEASONAL AVERAGES BY MONDAY AND WILL REMAIN NEAR
NORMAL THROUGH THE END OF THE WEEK,
&&
.AVIATION...
WIDESPREAD MTN OBSCURING IFR CONDITIONS IN MODERATE TO HEAVY SNOW
FALL ACROSS THE SOUTHERN SIERRA NEVADA AND TEHACHAPI RANGE THROUGH
08Z SATURDAY. CONDITIONS IMPROVING AFTERWARD. ACROSS THE SAN JOAQUIN
VALLEY...THUNDERSTORMS POSSIBLE BETWEEN 18Z AND 23Z TODAY.
OTHERWISE...MVFR ACROSS THE VALLEY AND KERN DESERTS WITH LOCAL IFR
CONDITIONS IN HEAVY SHOWERS THROUGH 06Z SATURDAY. MVFR CONDITIONS
CONTINUING THROUGH 18Z SATURDAY.
&&
.AIR QUALITY ISSUES...
NONE.
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 11 PM PDT THIS EVENING CAZ096-097.
WINTER STORM WARNING UNTIL 5 AM PDT SATURDAY CAZ095.
WIND ADVISORY UNTIL 5 AM PDT SATURDAY CAZ098-099.
&&
$$
PUBLIC...DCH/JEB
AVN/FW...MOLINA
SYNOPSIS...ANDERSEN
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
612 PM EDT FRI APR 13 2012
.SYNOPSIS...
HIGH PRESSURE OVER THE MIDDLE ATLANTIC REGION LATE THIS AFTERNOON
WILL MOVE OFF THE EAST COAST TONIGHT AND SATURDAY. THIS WILL ALLOW A
DEVELOPING LOW PRESSURE SYSTEM OVER THE PLAINS STATES TO DEVELOP AND
MOVE TOWARD THE UPPER GREAT LAKES REGION BY LATE WEEKEND. A FRONTAL
SYSTEM ATTACHED TO THIS LOW WILL AFFECT OUR AREA SATURDAY NIGHT AND
EARLY SUNDAY. THE LOW WILL MOVE ACROSS SOUTHERN CANADA EARLY NEXT
WEEK AND A COLD FRONT WILL CROSS OUR AREA EARLY TUESDAY. MORE HIGH
PRESSURE WILL RETURN FOR THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
NUDGED TEMPS UP SLIGHTLY AND LOADED IN HRRR WHICH SEEMED TO HAVE A
PRETTY GOOD HANDLE ON THE SEA BREEZE FRONT.
AFTER QUIET AND FAIR WEATHER THROUGH THE DAY, A MAINLY CLEAR AND
QUIET EVENING AND OVERNIGHT IS IN STORE AS SURFACE HIGH PRESSURE
CONTINUES TO SETTLE OFF THE SOUTHERN MIDATLANTIC TO SOUTHEAST COAST.
WINDS THAT WERE OUT OF THE NORTHWEST THROUGH MOST OF THE DAY WILL
GRADUALLY BACK AND BECOME MORE WESTERLY THIS EVENING AND THROUGH THE
NIGHT. WINDS THROUGH THE NIGHT WILL BE UNDER 10 MPH, AND IN THE MOST
SHELTERED LOCATIONS MAY EVEN BECOME CALM FOR A FEW HOURS. FOR MOST
AREAS, HOWEVER, WE ARE EXPECTING A LIGHT WEST WIND TO PERSIST
THROUGH THE NIGHT. WITH THE AIR REMAINING MIXED ENOUGH TONIGHT AND
WITH RISING DEWPOINTS OVERNIGHT, WE DID NOT FEEL THAT ANY
FROST/FREEZE HEADLINES WERE NEEDED AT THIS TIME. AT BEST, IT IS
POSSIBLE FOR PATCHY FROST OVER THE HIGHER TERRAIN IN THE LEHIGH
VALLEY, SOUTHERN POCONOS, NORTHWEST AND PINE BARREN AREAS IN NJ.
WE ADDED IT TO THE GRIDS AND IN THE HWO AND WILL SEE HOW
TEMPERATURES TREND THIS EVENING ABOUT ANY POSSIBLE HEADLINES OR
STATEMENTS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
HIGH PRESSURE WILL BE SETTLING OFF THE SOUTHEASTERN SEABOARD DURING
SATURDAY. WEST TO SOUTHWESTERLY WINDS ARE EXPECTED DURING SATURDAY,
AND 925MB WINDS ALONG WITH BUFKIT SOUNDINGS SHOW THESE WINDS
BECOMING GUSTY DURING SATURDAY AFTERNOON. MOST OF SATURDAY WILL BE
DRY, WITH AMPLE SUNSHINE INTO THE EARLY AFTERNOON. BY LATE AFTERNOON
TO EVENING, MID TO HIGH CLOUDS WILL BE INCREASING ACROSS THE AREA IN
ADVANCE OF A WARM FRONT. THIS FRONT COULD BRING A FEW SHOWERS TO OUR
NORTHWEST ZONES AROUND SUNSET.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
AN UPPER RIDGE WILL BE BUILDING OVER THE EASTERN PART OF THE COUNTRY
DURING THE FIRST PART OF THE EXTENDED PERIOD. OVER THE WEST...A H5
TROUGH WILL BE DEEPENING. A SFC LOW BETWEEN THESE UPPER FEATURES
WILL STRENGTHEN AND BE CARRIE INTO THE UPPER GREAT LAKES. THE LOW
WILL THEN MOVE ACROSS SRN CANADA EARLY NEXT WEEK. WE WILL BE MOSTLY
TOO FAR WAY FROM THE LOW FOR ANY SIGNIFICANT RAINFALL FROM THE
SYSTEM. ONE EXCEPTION WILL BE SAT NIGHT WHEN THE ATTACHED WARM FRONT
MAY BE CLOSE ENOUGH FOR SOME SCAT SHOWER ACTIVITY. A FEW OF THE
SHOWERS MAY LINGER ACROSS NE PA OR NRN NJ INTO EARLY SUN.
TEMPERATURES WILL BECOME WELL ABOVE NORMAL SUN AND MON WITH HIGH
TEMPERATURES INTO THE 80S IN MANY AREAS. HUMIDITY LEVELS WILL BE
RATHER HIGH ALSO. A COLD FRONT WILL CROSS THE REGION EARLY TUE.
AN UNSETTLED PATTERN WILL BE OVER THE AREA NEXT WEEK WITH A WEAK SFC
HIGH AND A FEW UPPER VORT MAXS MOVING WITH THE UPPER H5 FLOW. THESE
FEATURES MAY TRIGGER SCAT SHOWERS TUE-THU...SO POPS IN THE CHC/SLGT
CHC RANGE ARE IN THE GRIDS ATTM. TEMPERATURES WILL COOL BACK CLOSER
TO NORMAL VALUES BY THE MIDDLE OF NEXT WEEK. HIGHS WED-THU WILL
MOSTLY BE IN THE 60S.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. LATE TODAY,
NORTHWEST WINDS WILL CONTINUE TO BACK TO THE WEST, BECOMING UNDER
TEN KNOTS DURING THIS EVENING. WESTERLY WINDS, GRADUALLY BECOMING
MORE SOUTHWEST, WILL BECOME GUSTY BY SATURDAY AFTERNOON, WITH GUSTS
UP TO 20 KNOTS POSSIBLE. MID/HIGH CLOUDS WILL THEN MOVE INTO THE
REGION LATE SATURDAY INTO SATURDAY EVENING AHEAD OF AN ADVANCING
WARM FRONT.
WE HAVE TAKEN NOTE OF THE SEA BREEZE DEVELOPMENT ALONG THE NJ COAST
AND HAVE INCLUDED THIS IN THE AFTERNOON TAF FOR KACY.
OUTLOOK...
SATURDAY NIGHT...MOSTLY VFR WITH SCATTERED SHOWERS.
SUNDAY THRU MONDAY...MOSTLY VFR.
MONDAY NIGHT THRU WEDNESDAY...MOSTLY VFR WITH SCATTERED SHOWERS.
&&
.MARINE...
WITH HIGH PRESSURE GRADUALLY SETTLING ALONG THE SOUTHEASTERN
SEABOARD THROUGH SATURDAY, WINDS OVER OUR WATERS WILL BE WESTERLY TO
SOUTHWESTERLY. BOTH WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW
ADVISORY CRITERIA TONIGHT THROUGH MOST OF SATURDAY. BY SATURDAY
NIGHT INTO SUNDAY, SEAS AND WIND GUSTS MAY APPROACH SCA CRITERIA.
SHOWERS MAY BE POSSIBLE, AS WELL, WITH A WARM FRONT APPROACHING THE
AREA.
OUTLOOK...
WE MIGHT COME CLOSE TO OR REACH SMALL CRAFT ADVISORY CRITERIA ON
SATURDAY NIGHT ON THE OCEAN. THERE IS A BETTER CHANCE FOR
SMALL CRAFT ADVISORY CONDITIONS IN THE SOUTHWEST FLOW PRECEDING
THE NEXT COLD FRONT FROM SUNDAY NIGHT INTO MONDAY NIGHT. SMALL
CRAFT ADVISORY CRITERIA FOR SEAS MIGHT LINGER INTO PART OF TUESDAY
ON THE OCEAN.
&&
.FIRE WEATHER...
INCREASINGLY DRY AND WINDY CONDITIONS ARE ANTICIPATED ON SATURDAY.
RELATIVE HUMIDITY VALUES WILL BE FALLING DURING THE DAY, AND ARE
EXPECTED TO FALL BELOW 30 PERCENT FOR A TIME IN MOST LOCATIONS. IN
ADDITION, WIND GUSTS AROUND 20 MPH ARE ALSO FORECAST DURING THE
AFTERNOON. FUELS ALSO REMAIN DRY ACROSS THE REGION, THANKS TO THE
RECENT LACK OF PRECIPITATION. AFTER COORDINATION WITH OUR STATE
FORESTRY PARTNERS, WE PLAN TO ISSUE A SPECIAL WEATHER STATEMENT
SATURDAY MORNING TO HIGHLIGHT THE ENHANCED FIRE WEATHER CONCERNS.
&&
.CLIMATE...
POTENTIAL FOR NEAR RECORD HEAT MONDAY.
HERE ARE THE RECORD HIGH TEMPERATURES FOR ALL 8 OF OUR CLIMATE SITES
FOR MONDAY AND TUESDAY.
4/16 4/17
ALLENTOWN 89 - 2002 91 - 2002, 1976
ATLANTIC CITY 89 - 2002 94 - 2002
GEORGETOWN 89 - 2002 94 - 2002
MOUNT POCONO 85 - 2002 87 - 2002
PHILADELPHIA 90 - 2002 95 - 2002
READING 88 - 2002 95 - 1976
TRENTON 90 - 2002 93 - 2002
WILMINGTON 92 - 1896 97 - 1896
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...GIGI/KLINE
SHORT TERM...KLINE
LONG TERM...O`HARA
AVIATION...KLINE/O`HARA
MARINE...KLINE/O`HARA
FIRE WEATHER...KLINE
CLIMATE...DRAG
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
418 PM EDT FRI APR 13 2012
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 417 PM EDT FRI APR 13 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW MID/UPPER LEVEL TROF OVER
THE WRN CONUS WITH DOWNSTREAM RIDGE FROM THE WRN GULF TO THE WRN
LAKES. VIGOROUS LOOKING SHORTWAVE WAS LIFTING NNE THRU SW MN.
DESPITE VIGOROUS LOOK...SHRA AHEAD OF FEATURE HAVE BEEN WEAKENING AS
THEY MOVE E INTO THE VERY DRY AIRMASS ASSOCIATED WITH RIDGE PER 12Z
KGRB SOUNDING. THIS TREND WILL LIKELY CONTINUE AS SHORTWAVE
PROGRESSES INTO THE MEAN RIDGE POSITION...ESPECIALLY WITH 850MB FLOW
VEERING MORE WRLY AND MOISTURE TRANSPORT WEAKENING WITH TIME. SHRA
CURRENTLY DEVELOPING AROUND VORT MAX IN SW MN MAY BRUSH THE NW FCST
AREA DURING THE NIGHT. AT THIS POINT...IT DOESN`T LOOK LIKE ANYTHING
HIGHER THAN CHC/SCT POPS ARE WARRANTED. WHERE PCPN OCCURS...AMOUNTS
WILL BE LIGHT...UNDER 0.1 INCHES.
SAT...ANY LINGERING SCT PCPN OVER THE NRN AND ERN FCST AREA WILL
MOVE OUT DURING THE MORNING AS DRY SLOT UNDERNEATH UPPER LEVEL JET
STREAK SHIFTS OVER THE AREA. DRYING COLUMN AND TREND TO MOSTLY SUNNY
SHOULD ALLOW FOR DEEP MIXING TO AT OR ABOVE 800MB SAT AFTN. PER FCST
SOUNDINGS...THIS WILL ALLOW TEMPS TO RISE TO AROUND 70F AWAY FROM
MARINE INFLUENCES. MIXING WILL HELP DWPTS FALL IN THE AFTN. IF
MIXING HEIGHTS ARE A LITTLE HIGHER THAN EXPECTED...DWPTS WILL FALL
SEVERAL DEGREES MORE THAN REFLECTED IN THIS FCST ISSUANCE. AS IT IS
NOW...HAVE RH FALLING TO AROUND 30PCT. WITH GUSTY WSW WINDS...THERE
WILL BE AN ELEVATED RISK OF WILDFIRES SAT AFTN...ESPECIALLY OVER THE
W HALF WHERE TEMPS/WINDS WILL BE HIGHEST.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 417 PM EDT FRI APR 13 2012
MAIN ISSUE FOR THE LONG TERM PERIOD IS THE SUNDAY/MONDAY TIME
FRAME AS DEEP WESTERN TROUGHS HEADS EAST INTO THE LARGE RIDGE
OVR THE EASTERN CONUS. SHORTWAVE TROUGH CURRENTLY BRINGING RAIN
AND TSRA TO SOUTHERN CALIFORNIA IS FCST TO DIG INTO FOUR CORNERS
AREA ON SATURDAY THEN LIFT INTO THE UPPER MISSISSIPPI RIVER VALLEY
BY LATER SUNDAY. IN THE LOW-LEVELS SFC-H85 LOWS FORM OVER SOUTHERN
PLAINS WHILE WARM FRONT BULGES AS FAR NORTH AS NEB AND IA BY
SATURDAY EVENING. POSITIVES FOR PRECIPITATION ON SATURDAY NIGHT IS
FACT THAT UPR MI IS WITHIN BROAD AREA OF DIVERGENCE ALOFT DUE TO JET
STREAK LIFTING ACROSS ONTARIO AND ANOTHER NOSING IN FM THE SOUTHERN
PLAINS. H85 THETA-E ADVECTION ALSO FCST TO ROLL ACROSS UPR LAKES.
WHILE THIS AND THE DIVERGENCE ALOFT MAY HELP TRIGGER AT LEAST SCT
SHOWERS...EXPECT BETTER RAIN CHANCES OVER SOUTH AND EAST CWA CLOSER
TO MAXIMUM H85-H7 MOISTURE TRANSPORT. PTYPE THIS FIRST BATCH OF
PRECIP STRICTLY RAIN AS H85 TEMPS ARE AOA +5C AND SFC DWPNTS REMAIN
AOA 40F. PROBABLY WILL BE A BREAK IN SHOWERS LATE SATURDAY NIGHT
INTO SUN MORNING...BUT GIVEN PERSISTENT H85 THETA-E ADVECTION AND
THAT UPR JET FORCING STILL AROUND FCST WILL KEEP BROADBRUSHED CHANCE
POPS.
LATER SUNDAY...ATTN IS SQUARELY ON APPROACHING DEEP SHORTWAVE TROUGH
LIFTING INTO VCNTY OF NORTHEAST NEB INTO SOUTHWEST MN. SFC LOW FCST
TO PUSH INTO WCNTRL WI BY AFTN WHILE WARM FRONT ATTM IS FCST TO LIFT
INTO NORTHERN WI AND PERHAPS SCNTRL UPR MI. TREND FM LATEST MODELS
IS FOR 12Z NAM/GFS TO BRING SFC LOW NEAR IMT BY 00Z. GIVEN SE WINDS
OFF LK MICHIGAN WOULD EXPECT THE WARM FRONT TO STRUGGLE ANY FARTHER
NORTH AND EAST. CONVECTION SHOULD BE ONGOING AND/OR RE-DEVELOPING
SUNDAY AFTN AHEAD OF PRE-FRONTAL DRY LINE SLIDING ACROSS SOUTHERN
MN INTO IA. SW H85-H7 WINDS WILL ADVECT CONVECTION INTO CWA LATER
IN THE DAY WITH INCREASING POTENTIAL OF SEVERE STORMS IF THE WARM
FRONT IS INDEED OVR NORTHERN WI/SOUTH CNTRL UPR MI GIVEN STEEP H7-H5
LAPSE RATES AOA 7C/KM JUST UPSTREAM. ALL EVENTS ARE DIFFERENT...BUT
SHOULD NOTE THAT THE UPR LEVEL AND MSLP/T/TD PATTERN LOOK SOMEWHAT
SIMILAR TO 10 APRIL 2011 WHEN A COUPLE CLUSTERS OF SEVERE STORMS
IMPACTED PORTIONS OF NORTHERN WISCONSIN AND SOME HAIL AFFECTED
PORTIONS OF CWA. SVR THREAT FOR CWA WILL LARGELY DEPEND ON HOW FAR
NORTH WARM FRONT MAKES IT.
THIS IS DYNAMIC/SPRING PATTERN FOR SURE. 24-HOURS AGO IT LOOKED MAIN
IMPACT FM THE SYSTEM WOULD BE ACCUMULATING SNOW SUNDAY NIGHT INTO
MONDAY. NOW...THERE COULD BE SEVERE WX SUNDAY THEN POSSIBILITY OF
SNOW LATE SUNDAY NIGHT AND MONDAY MORNING. FARTHER NORTH TRACK TO
SFC LOW WOULD DELAY THE CHANGEOVER TO SNOW UNTIL AFTER MIDNIGHT OVER
ONLY THE FAR WEST PORTION OF UPR MI. ALSO...THE FARTHER NORTH H85
BAROCLINIC ZONE RESULTS IN FARTHER NORTH DEFORMATION PRECIPITATION
AREA...SO MODELS HAVE TRENDED LESS WITH PRECIPITATION OVERNIGHT
SUNDAY NIGHT WHEN THE CHANGEOVER TO SNOW WOULD OCCUR. BLEND OF
LATEST GFS/ECMWF/CANADIAN WOULD POINT TO A FEW INCHES OF SNOW
POSSIBLE IN THE WEST AND MAYBE NORTH CENTRAL CWA LATER SUNDAY NIGHT
INTO MONDAY MORNING. FINAL VERDICT WITH SPECIFICS OF THE SYSTEM ARE
FAR FM IN...SO WILL ONLY TWEAK FCST GIVEN THE LATEST MODEL TRENDS.
WILL CONTINUE TO MENTION ACCUMULATING SNOW IN HWO. ALSO WILL PUT A
MENTION OF STORMS AND POSSIBLE HAIL FOR SUNDAY.
IN THE EXTENDED...ONCE LOW BLOWS BY UPR LAKES...A DRY AND CHILLY
PATTERN IS EXPECTED TUESDAY INTO WEDNESDAY MORNING AS HIGH PRESSURE
DRIFTS ACROSS ONTARIO AND UPR GREAT LAKES. NEXT CHANCE OF RAIN
ARRIVES LATER WEDNESDAY AS SHORTWAVE AND SFC TROUGH PRESS INTO UPR
GREAT LAKES IN INCREASINLY QUICK WNW FLOW ALOFT. ANOTHER COUPLE
DISTURBANCES COULD BRING MORE PRECIPITATION BACK TO THE UPR LAKES
THURSDAY INTO FRIDAY AS WELL THOUGH TIMING IS STILL UNCERTAIN.
CONSENESUS GIVES 20-30 POPS FOR NOW WHICH IS FINE. CORE OF COOLER
AIR LURKING JUST NORTH OF LK SUPERIOR LATE IN THE WEEK COULD LEAD TO
RAIN/SNOW WITH THE SYSTEMS AS THEY MOVE THOUGH DEPENDING ON TIME OF
DAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 134 PM EDT FRI APR 13 2012
VFR CONDITIONS WILL CONTINUE THRU THE AFTN HRS AT KIWD/KCMX/KSAW AS
VERY DRY AIRMASS LINGERS OVER THE AREA. LOW PRES SYSTEM LIFTING THRU
MN INTO NRN ONTARIO TONIGHT AND SAT WILL BRING A FEW SHRA TO THE
AREA TONIGHT. PCPN SHOULD BE LIGHT AND NOT DROP VIS BLO VFR AS
SYSTEM WILL BE WEAKENING WITH TIME. HOWEVER...LOW-LEVEL MOISTURE IS
MOVING NE PER OBS/SATELLITE AND SHOULD RESULT IN CIGS DROPPING TO
MVFR TONIGHT. ON SAT...DRYING OF THE COLUMN UNDERNEATH UPPER JET
STREAK WILL RESULT IN IMPROVEMENT TO VFR IN THE MORNING HRS. WINDS
WILL BE GUSTY SAT...ESPECIALLY AT KCMX UNDER A MORE FAVORABLE WRLY
FLOW THERE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 417 PM EDT FRI APR 13 2012
SOUTHEASTERLY WINDS WILL BE IN THE 15-25KT RANGE AT TIMES OVER MUCH
OF LAKE SUPERIOR TONIGHT AS LOW PRES LIFTS FROM THE ERN DAKOTAS TO
NRN ONTARIO. MIGHT SEE GUSTS AROUND 30KT AT THE HIGHEST OBSERVING
PLATFORMS. AS THE LOW MOVES TO NRN ONTARIO SAT...WINDS WILL SHIFT
AROUND TO THE SW...FAVORING THE W HALF OF LAKE SUPERIOR FOR STRONGER
WINDS...AGAIN INTO THE 15-25KT RANGE AT TIMES. MIGHT SEE SOME GUSTS
TO AROUND 30KT AT THE HIGHEST OBSERVING PLATFORMS THRU ABOUT MID
AFTN DUE TO FAVORABLE ISALLOBARIC COMPONENT. BTWN SYSTEMS...THERE
WILL BE A BRIEF PERIOD OF LIGHTER WINDS UNDER 15KT SAT NIGHT.
ATTENTION THEN TURNS TO THE NEXT LOW PRES SYSTEM THAT WILL MOVE ENE
FROM THE CNTRL PLAINS LATE SAT NIGHT. NE WINDS MAY REACH GALE FORCE
LATE SUN ACROSS W AND CNTRL LAKE SUPERIOR ON THE NW FLANK OF THE LOW
MOVING THRU THE GREAT LAKES. GALES SHOULD THEN SHIFT TO ERN LAKE
SUPERIOR EARLY MON AS WINDS BACK TO THE N BEHIND THE DEPARTING LOW.
WINDS WILL DROP BACK UNDER 20KT TUE AS HIGH PRES ARRIVES...AND THE
LIGHTER WINDS SHOULD LINGER INTO WED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
135 PM EDT FRI APR 13 2012
.SYNOPSIS...
ISSUED AT 453 AM EDT FRI APR 13 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH OVER
THE WRN CONUS AND A DOWNSTREAM RIDG FROM ERN TX INTO THE UPPER MS
VALLEY. A VIGOROUS SHORTWAVE TROUGH OVER WRN KS WAS LIFTING NE. AT
THE SFC...SE FLOW WAS INCREASING OVER MN AND WRN WI BTWN HIGH PRES
OVER LAKE HURON AND A TROUGH OVER THE PLAINS. IR LOOP SHOWED HIGH
CLOUDS EXPANDING INTO WRN UPPER MI ASSOCIATED WITH THE DEVELOPING
WAA PATTERN TO THE WEST.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 453 AM EDT FRI APR 13 2012
TODAY INTO TONIGHT...
HIGH AND MID CLOUDS WILL CONTINUE TO SPREAD INTO THE CWA. THE CLOUDS
SHOULD BE THIN ENOUGH TO ALLOW PLENTY OF SUNSHINE AND DECENT MIXING
ALONG WITH WAA TO PUSH TEMPS INTO UPPER 50S AND LOWER 60S. THIS
SHOULD ALSO KEEP DEWPOINTS IN THE LOWER 20S OVER MUCH OF THE
AREA...RESULTING IN RH VALUES IN THE 20 TO 25 PERCENT RANGE. THE DRY
AIR COMBINED WITH SOUTH WINDS OF 10 TO 20 MPH WILL LEAD TO ELEVATED
FIRE WX RISK. SO...WL CONTINUE TO HIGHLIGHT THE HAZARD WITH THE
WILDFIRE POTENTIAL STATEMENT.
MDLS SUGGEST THAT AS THE PLAINS SHRTWV LIFTS INTO THE UPPER MS
VALLEY AND WRN LAKE SUPERIOR...MODERATE 700-500 MB QVECTOR CONV...
WAA/ISENTROPIC LIFT ALONG WITH FAVORABLE MOISTURE TRANSPORT WILL
PRODUCE SCT/NMRS SHRA. MODELS CONTINUED WITH THE TREND TOWARD A
LATER ARRIVAL OF PCPN INTO THE WEST BUT THEN MOVE THE BAND QUICKLY THROUGH
THE WEST IN THE EVENING. EXPECT THE GREATEST PCPN COVERAGE/POPS OVER
THE NW HALF OF THE CWA...CLOSER TO THE PATH OF THE SHRTWV AND UPPER
LEVEL DIV WITH THE LEFT EXIT REGION OF THE 250-300 MB JET. SINCE THE
DYNAMICS MOVE INTO THE DRY AIRMASS FAIRLY QUICKLY ...ONLY LIGHT PCPN
AMOUNTS OF A TENTH OF AN INCH OR LESS ARE EXPECTED. WITH ELEVATED
CAPE REMAINING SOUTH OF THE AREA...PER NAM/GFS...NO TSRA ARE
EXPECTED. THE PCPN SHOULD DIMINISH OVER THE WEST BY LATE EVENING AND
OVER THE CENTRAL AND EAST AFTER MIDNIGHT.
SATURDAY...ANY LINGERING PCPN OVER THE ERN CWA SHOULD MOVE OUT EARLY
AS THE AREA FALLS UNDER THE DRY SLOT. 850 MB TEMPS TO AROUND 10C
ALONG WITH SUNSHINE SHOULD PUSH TEMPS TO AROUND 70.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 453 AM EDT FRI APR 13 2012
SAT NGT...AS FAIRLY POTENT SHRTWV BEGINS TO LIFT NEWD OUT OF THE SW
CONUS...SFC LO PRES IS FCST TO DVLP IN THE CENTRAL PLAINS. THE 00Z
GFS/NAM HAVE TRENDED TOWARD A DEEPER LO PRES FARTHER TO THE N THAN
THE 12Z ECMWF AND 00Z CNDN/UKMET. PER NCEP GUIDANCE...WL FOLLOW THE
SCENARIO CLOSER TO THE 12Z ECMWF/21Z SREF. THIS GUIDANCE SHOWS A
WEAK HI PRES RDG IN THE WAKE OF DISTURBANCE RESPONSIBLE FOR THE SAT
POPS BRINGING A BRIEF PERIOD OF DRY WX SAT EVNG. HOWEVER...APRCH OF
ATTENDANT WARM FNT AND UPR DVGC IN RRQ OF 120KT H3 JET MAX IN SE
ONTARIO WL BRING A RETURN OF POPS FM THE SW AFT 06Z...ESPECIALLY
OVER THE S HALF OF THE CWA. WL RETAIN SCHC FOR TS OVER THE SCNTRL
PER ECWMF/SREF FCST SSI NOT FAR ABOVE ZERO/CLOSER PROXIMITY TO WARM
FNT. BUT EXPECT A FAIRLY SHARP GRADIENT OF POPS TO THE N AS THE
ECMWF SHOWS VERY DRY AIR AT H7 OVER NRN LK SUP AND N H925 WINDS ON
THE SRN FLANK OF BLDG HI PRES IN SCNTRL CAN PUSHING DRIER AIR ACRS
THE LK.
SUN...ALTHOUGH THERE ARE SOME TIMING DIFFERENCES...THE SREF/ECMWF
INDICATE SOME LO/MID LVL DRYING ON SUN AS RRQ DYNAMICS EXIT WELL TO
THE NE OF SHRTWV/SFC LO IN THE CENTRAL PLAINS. SO REDUCED POPS A BIT
ARND MID DAY BEFORE THE LO PRES TO THE SW BEGINS TO MOVE NE AND
INCRS PCPN CHCS ESPECIALLY NEAR THE WI BORDER LATER IN THE DAY.
TENDED TOWARD THE LO END OF GUIDANCE FOR TEMPS GIVEN THE LLVL NLY
FLOW OFF THE CHILLY WATERS OF LK SUP SHOWN BY THE ECMWF.
SUN NGT...SHRTWV/SFC LO LIFTING NEWD OUT OF THE PLAINS ARE FCST TO
APRCH THE UPR LKS...WITH 12HR H5 FALLS FCST UP TO 120M ASSOCIATED
WITH VIGOROUS DEEP LYR QVECTOR CNVGC. ALTHOUGH THE ECMWF/SREF
INDICATE SOME DRY SLOTTING MAY IMPACT AT LEAST THE SCNTRL LATE...
ELEVATED POPS TO LIKELY GIVEN IMPRESSIVE DYNAMICS. PCPN SHOULD BE IN
THE FORM OF RA IN THE EVNG...BUT AS LLVL COLDER AIR IS DRAWN INTO
THE WRN ZNS...EXPECT THE COMBINATION OF THIS LLVL CAD AND DYNAMIC
COOLING TO BRING A WINTRY MIX. 12Z ECMWF FCST SDNGS AND FCST H100-85
THKNS FIELDS SUG THERE COULD BE A NARROW BAND OF FZRA WHERE THE LLVL
COLD AIR INFUSION IS SHALLOW AND IN THE ABSENCE OF ANY DIURNAL
HEATING LATE AT NGT. DEPENDING ON HOW QUICKLY DEEPER COLD AIR CAN
MOVE INTO THE W HALF...AT LEAST SEVERAL INCHES OF SNOW ARE PSBL IN
THAT AREA...ESPECIALLY WHERE THE LLVL CYC NNE FLOW WL UPSLOPE.
MON...AS THE SHRTWV BEGINS TO SHEAR TO THE NE ON THE NW FLANK OF UPR
RDG OVER THE SE CONUS AND INCOMING COLD AIR BEGINS TO CAUSE LARGER
SCALE QVECTOR DVGC...EXPECT PCPN SHIELD TO SLOWLY DECAY EVEN THOUGH
LINGERING CHILLY LLVL CYC NNE FLOW WL LINGER AND BRING ABOUT
CONTINUED PCPN CHCS ESPECIALLY OVER THE NW HALF. A FEW INCHES MORE
OF SN ARE PSBL OVER THE HIER TERRAIN OF THE NW HALF ON THE NW FLANK
OF THE H85 LO TRACK BEFORE THE PCPN DIMINISHES IN THE AFTN.
EXTENDED...A DRIER BUT CHILLY PATTERN WL DOMINATE TUE INTO EARLY WED
WITH HUDSON BAY HI PRES BLDG INTO ONTARIO. MORE PCPN IS PSBL ON WED
INTO THU AS ANOTHER PAIR OF DISTURBANCES ARE FCST TO IMPACT THE GREAT
LKS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 134 PM EDT FRI APR 13 2012
VFR CONDITIONS WILL CONTINUE THRU THE AFTN HRS AT KIWD/KCMX/KSAW AS
VERY DRY AIRMASS LINGERS OVER THE AREA. LOW PRES SYSTEM LIFTING THRU
MN INTO NRN ONTARIO TONIGHT AND SAT WILL BRING A FEW SHRA TO THE
AREA TONIGHT. PCPN SHOULD BE LIGHT AND NOT DROP VIS BLO VFR AS
SYSTEM WILL BE WEAKENING WITH TIME. HOWEVER...LOW-LEVEL MOISTURE IS
MOVING NE PER OBS/SATELLITE AND SHOULD RESULT IN CIGS DROPPING TO
MVFR TONIGHT. ON SAT...DRYING OF THE COLUMN UNDERNEATH UPPER JET
STREAK WILL RESULT IN IMPROVEMENT TO VFR IN THE MORNING HRS. WINDS
WILL BE GUSTY SAT...ESPECIALLY AT KCMX UNDER A MORE FAVORABLE WRLY
FLOW THERE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 453 AM EDT FRI APR 13 2012
SE WINDS WILL INCREASE TO 20-25 KT AS A TROUGH MOVES TOWARD THE UPPER
MS VALLEY. AS THE LOW MOVES TO THE NORTH OF THE AREA SATURDAY...20-25
KT WINDS WILL VEER TO THE SW.
EXPECT INCRSG NE WINDS TO AT LEAST APPROACH GALE FORCE ON SUN NIGHT
INTO MON ON THE NW FLANK OF LO PRES MOVING THRU THE GREAT LAKES AS
THE PRES GRADIENT SHARPENS BETWEEN THIS FEATURE AND HI PRES BUILDING
TOWARD NW ONTARIO. LIGHTER WINDS WILL ARRIVE ON MON NIGHT INTO TUE AS
HI PRES BUILDS OVER THE UPPER LKS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...KC
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
423 PM CDT FRI APR 13 2012
.DISCUSSION...
Short Range (Tonight through Sunday)...
Surface trough extends from western IA through nw MO and through nw
OK. Boundary appears to have stalled and is delineated by cumulus
congestus on the northern portion and developing strong/possible
severe convection from southeastern KS swwd. This latter activity is
best handled by LSX local WRF while the 18z HRRR and 12z 4km NMM-WRF
models are a bit slower in their evolution. Airmass is moderately
unstable with MUCAPE in the 2000-2500 J/kg range with 40kt 0-6km
shear and 200 m2/s2 storm relative helicity, in essence enough to
support supercells. As the low level jet kicks in this evening
expect the growing area of convection to expand east-northeastward
along a pseudo warm front that the LSX local WRF extends across the
far southern counties. This boundary and the convection will be
supported by the increasing southerly low level jet and allow the
complex to spread north toward the MO River by Saturday morning.
Have used this idea to construct grids/zones for tonight. There will
be some severe potential for the far southern counties overnight
with large hail the primary severe threat. Heavy rains are possible
over the far southern counties but 3hr flash flood guidance
averaging 2.5 inches/3 hours suggests rainfall tonight not enough to
warrant a watch.
Activity will likely be ongoing across area south of the MO River.
The warm front and convection will continue northward during the day
and have scaled back afternoon pops south of the MO River.
Temperatures will be tricky due to the rain cooled airmass and cloud
cover. Should the sun fail to come out the current temperatures,
although cooler than the previous forecast, may prove to be still
too warm.
Severe risk during the daylight hours will be tied to the morning
convection and believe it will be quite low as the airmass will
likely be quite saturated and minimal instability. Main focus for
the severe risk will be Saturday late evening into Sunday morning.
Upstream severe weather outbreak will likely advance steadily
eastward as a squall line as individual cells race northeast off the
line in excess of 50kts. Despite weakening instability during the
evening hours the low level shear will be quite high and thus still
able to support rotating individual storms through the night. As a
result there will be a risk of severe weather mainly west of
Interstate 35 for Saturday night. All storm modes...large hail,
damaging winds and isolated tornadoes...will be possible.
Sunday`s severe threat will likely be held hostage by how Saturday
night`s convective event unfolds and lays out any boundaries. Will
use a model consensus approach which suggests best convective
chances will be over the eastern half of the CWA. Rain chances will
end from west to east during the day on Sunday with Sunday night
likely dry.
MJ
Medium Range (Monday through Friday)...
By Monday the upper level trough that made for a stormy weekend will
shift east of the area and flatten out as the upper level flow
across the CONUS becomes more zonal. The main weather concerns will
revolve around two chances for precipitation, the first on Wednesday
and again Friday. High pressure will move into the area on Monday
behind a departing cold front. Temperatures will range into the
upper 50s to lower 60s. The surface ridge will remain over the area
on Tuesday as abundant sunshine will help temperatures range into
the low to mid 60s. On Wednesday a weak upper level shortwave
embedded in the zonal flow will move through the Upper Midwest
forcing a weak cold front through the area. Some light showers will
be possible with this system on Wednesday with the best chance for
showers along the Missouri/Iowa border. Thursday will feature a
return to southerly flow out ahead of another cold front moving
through the Plains. This will allow high temperatures to reach into
the 70s across the forecast area. Friday, a another upper level
shortwave will drop southeastward from the Northern Plains into the
Midwest which will force the aforementioned cold front though the
area. Showers and thunderstorms will be possible on Friday as the
front moves through thus have chance pops in for the day Friday.
73
&&
.AVIATION...
For the 18Z TAFs...Afternoon cigs expected to improve from MVFR to
VFR and eventually scatter out by early evening as surface winds
veer to the south and increase in speed. Will need to watch a weak
surface trough stalling out over nw MO this evening as some short
range models suggest a short line of convection could pop up this
evening and then dissipate.
Think MVFR fog will form during the pre-dawn hours at all 3
terminals due to increasing low level moisture and minimal cloud
cover. MVFR cigs will also return and there is the potential for IFR
cigs to form instead as the fog layer congeals. Convection likely to
form from OK through southern MO this evening and lift/spread
northward and could reach the KC Metro before sunrise.
MJ
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1204 PM CDT FRI APR 13 2012
.UPDATE...
ISSUED AT 1155 AM CDT FRI APR 13 2012
AREA OF RAIN AND EMBEDDED THUNDERSTORMS CONTINUES TO SLOWLY MOVE
EAST ACROSS THE FORECAST AREA LATE THIS MORNING. LOW LEVEL JET
CONTINUES TO WEAKEN AND VEER...ALLOWING A SLOW DIMINISHING TREND
AND SHIFT TO THE PRECIP TO THE SOUTHEAST. EXPECT BACK EDGE OF
STEADY RAIN TO CLEAR DOWNTOWN AROUND 3:30 PM. TEMPERATURES HAVE
FALLEN INTO THE UPPER 40S AND LOWER 50S WITH THE RAIN. EXPECT SOME
REBOUND IN CENTRAL MISSOURI LATE THIS AFTERNOON...WITH STEADY
TEMPS ELSEWHERE.
CVKING
&&
.SHORT TERM...
ISSUED AT 353 AM CDT FRI APR 13 2012
(TODAY)
DIFFICULT PRECIPITATION FORECAST FOR TODAY...WHICH ALSO MAKES FOR A
DIFFICULT TEMPERATURE FORECAST. CURRENT RADAR HAS SCATTERED TO
NUMEROUS THUNDERSTORMS BREAKING OUT ALONG A LINE FROM JOPLIN TO
SEDALIA. THE STORMS ARE BEING FED BY A BROAD LOW LEVEL JET WITH
8-10C DEWPOINTS EMBEDDED IN IT. BROAD BUT SUBSTANTIAL MOISTURE
CONVERGENCE IS OCCURRING WHERE THE LOW LEVEL JET IS IMPACTING THE
WESTERN EDGE OF THE RIDGE OVER THE OHIO VALLEY. THE RUC HAS BEEN
CONSISTENTLY PUSHING THE AREA OF MOISTURE CONVERGENCE EAST THROUGH
THE MORNING. MESOSCALE MODELS INCLUDING THE NSSL 4KM WRF...THE NCEP
4KM WRF...OUR OWN LOCALLY RUN WRF...THE HRRR...AND THE EXPERIMENTAL
NARRE ALL SHOW THIS CONVECTION CONTINUING AS THE MOISTURE
CONVERGENCE SPREADS EAST. THE REAL QUESTION IS WHAT THE SOUTHERN
EXTENT WILL END UP BEING. THE HRRR AND THE VARIOUS HI RES WRFS
SPREAD RAIN OVER MOST OF THE CWFA WHILE OPERATIONAL MODELS SUCH AS
THE GFS AND NAM KEEP PRECIP CONFINED TO THE NORTHERN 2/3 OF THE
AREA. WITH PRECIP WELL INTO SOUTHERN MISSOURI AT THIS TIME...HAVE
DECIDED TO FOLLOW THE MORE WIDESPREAD SOLUTIONS OF THE MESOSCALE
MODELS AT THIS TIME. TEMPERATURES WILL DEPEND GREATLY ON CONVECTION
TODAY. STUCK PRETTY CLOSE TO A BLEND OF NAM/GFS MOS GUIDANCE.
CARNEY
&&
.LONG TERM...
ISSUED AT 353 AM CDT FRI APR 13 2012
(TONIGHT THROUGH THURSDAY)
IT APPEARS THERE WILL BE A LULL IN THE PRECIPITATION THIS EVENING
BEFORE THE NEXT ROUND OF SHOWERS AND THUNDERSTORMS GETS GOING LATE
THIS EVENING...AND MORE LIKELY OVERNIGHT. GUIDANCE IS IN GOOD
AGREEMENT SHOWING AN IMPULSE IN THE SW FLOW ALOFT TRACKING INTO
CENTRAL MO BETWEEN 06-12Z INTERACTING WITH A 30-40 KT SWLY LLJ
POSITIONED THRU THE CWA. THE MAIN QUESTION IS THE LOCATION WHERE
THE THUNDERSTORMS WILL ALIGN/FOCUS...WITH A RANGE OF SOLUTIONS
FROM ACROSS FAR NORTHERN MO TO JUST NORTH OF I-44. THE GREATEST
CONSENSUS IS THIS AXIS WILL BECOME ESTABLISHED FROM AROUND
COLUMBIA THROUGH BOWLING GREEN. SHOWERS AND THUNDERSTORMS WILL
GRADUALLY SHIFT TO THE EAST ON SATURDAY MORNING AND BELIEVE WILL
MOST OF THE ACTIVITY WILL HAVE EXITED THE CWA BY 18Z AS THE
IMPULSE MIGRATES TO THE NORTHEAST INTO CENTRAL IL. AFTERNOON
TEMPERATURES SHOULD RECOVER NICELY IN THE WAKE OF THE MORNING
CONVECTION AS CLOUDS DECREASE...WARMING INTO THE 70S.
THERE ISNT MUCH TO LATCH ONTO FOR POPS ON SATURDAY NIGHT. THE MOST
UNSTABLE AIR WILL RESIDE ACROSS THE NORTHERN PORTION OF THE CWA
WHILE A 50+ KT LLJ WILL REMAIN POSITIONED ACROSS THE AREA. ITS HARD
TO SAY IF THERE WILL BE A RESIDUAL OUTFLOW BOUNDARY FROM THE
CONVECTION EARLIER IN THE DAY. AND...THE MODELS FAIL TO DEPICT ANY
DISCERNABLE SURFACE BOUNDARIES OR DISTURBANCES ALOFT WHICH WOULD
HELP FOCUS CONVECTION. THUS WHILE I CAN`T RULE OUT
PRECIPITATION...ANY SHOWERS AND THUNDERSTORMS WOULD APPEAR TO HAVE
LIMITED ORGANIZATION AND BE MORE SPOTTY IN COVERAGE WITH THE
GREATEST PROBABILITY ACROSS NE MO INTO WEST CENTRAL IL IN PROXIMITY
TO THE GREATEST INSTABILITY.
IT APPEARS THE MAIN THRUST OF SHOWERS AND THUNDERSTORMS WILL BE ON
SUNDAY AFTERNOON AND EVENING AS THE MAIN UPPER TROF PROGRESSES INTO
THE MID MS VALLEY. DEEP LAYER SHEAR OF 60+ KTS WITHIN THE WARM
SECTOR AND MUCAPES OF 750-1500 J/KG SUGGEST A THREAT OF ORGANIZED
SEVERE STORMS WITH A MIXED MODE IN THE AFTERNOON TRANSITIONING TO
MORE LINEAR DURING THE EVENING. BELIEVE MOST OF THE PRECIPITATION
WILL HAVE EXITED TO THE EAST OF THE CWA ON MONDAY MORNING...WITH
DRIER AND COOLER AIR SPREADING ACROSS THE AREA IN THE WAKE OF THE
COLD FRONTAL PASSAGE.
GLASS
&&
.AVIATION...
ISSUED AT 1155 AM CDT FRI APR 13 2012
AREA OF RAIN WITH EMBEDDED THUNDERSTORMS WILL MOVE EAST ACROSS THE
AREA THIS AFTERNOON...CLEARING FROM WEST-NORTHWEST TO EAST-
SOUTHEAST. EXPECT KUIN AND KCOU SHOULD BE DONE WITH RAIN BY
18Z...AND ST. LOUIS METRO TAFS BETWEEN 20Z KSUS AND 21Z KCPS.
THUNDER WILL CONTINUE TO REFOCUS FURTHER SOUTH AS THE LOW LEVEL
JET VEERS...SO MAY JUST HAVE A VCTS TO COVER LIGHTNING GIVEN ISOLATED
NATURE IN ST. LOUIS. WIND TO REMAIN SOUTHEAST AT 10 TO 15 KTS.
QUIET WEATHER EXPECTED THIS EVENING BEFORE ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS DEVELOPS ACROSS EASTERN KANSAS AND
WESTERN MISSOURI AND MARCHES EAST ACROSS THE FORECAST AREA LATE
TONIGHT AND SATURDAY MORNING.
SPECIFICS FOR KSTL...
RAIN CONTINUES THROUGH 20Z WITH MOST OF THE THUNDER REMAINING
SOUTH OF THE TERMINAL. WIND TO REMAIN SOUTHEAST. QUIET WEATHER
EXPECTED TONIGHT...BEFORE ANOTHER ROUND OF SHOWERS AND STORMS
IMPACTS THE TERMINAL AFTER 06Z.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1118 AM MDT FRI APR 13 2012
.AVIATION...18Z TAF FORECAST
SCATTERED RAIN SHOWERS WITH AN ISOLATED THUNDERSTORM ARE POSSIBLE
THIS AFTERNOON OVER NORTHEASTERN WYOMING AND THE BLACK HILLS. MVFR
CIGS WILL BE POSSIBLE IN AND AROUND SHOWERS/STORMS. CONVECTION
SHOULD END THIS EVENING AFT 03Z BEFORE ANOTHER DISTURBANCE PUSHES
TOWARD THE AREA LATE TONIGHT. BETWEEN SYSTEMS VFR CONDITIONS ARE
EXPECTED. BY 12Z SATURDAY...MVFR CIGS WILL RETURN TO NORTHEASTERN
WYOMING...THE BLACK HILLS...AND SOUTHERN PORTIONS OF SOUTH DAKOTA.
&&
.PREV DISCUSSION... /ISSUED 904 AM MDT FRI APR 13 2012/
UPDATE...A WEAK SHORT-WAVE RIDGE OVER THE CWA THIS MORNING HAS
ALLOWED FOR CLEARING SKIES AS A VIGOROUS SHORT-WAVE TROUGH WAS
JUST EAST OF THE CWA...TAKING PRECIPITATION WITH IT. A SLOW-MOVING
LOW-AMPLITUDE SHORT-WAVE TROUGH WAS OVER SWRN WY...WITH STEEP
LAPSE RATES AND FAIRLY DEEP MOISTURE AHEAD OF IT PER THE 12Z KRIW
SOUNDING. AS THIS TROUGH DRIFTS SLOWLY NORTHEAST IT WILL SPREAD
ISOLD-SCT SHOWERS OVER NERN WY AND FAR SWRN SD THROUGH THE AFTN.
HOWEVER...A RELATIVELY DRY BOUNDARY LAYER OVER WRN SD WILL LIMIT
THE COVERAGE AND ERN EXTENT OF THE SHOWERS. OUR LOCAL WRF-ARW RUN
SUPPORTS THIS...BUT THE 12Z HRRR IS MUCH MORE AGGRESSIVE WITH
AFTN SHOWERS...WHICH IS INCONSISTENT WITH THE RELATIVELY DRY
BOUNDARY LAYER.
PREV DISCUSSION... /ISSUED 327 AM MDT FRI APR 13 2012/
DISCUSSION...
LONG WAVE RIDGE EXTENDS FROM MN TO LA WITH STRONG LONG WAVE TROF
NEAR THE WEST COAST. ONE STRONG SHORT WAVE EXTENDS FROM CNTRL MT
TO THE NE PANHANDLE WITH A SECOND STRONG SHORT WAVE MOVING INTO
THE LONG WAVE TROF ON THE WEST COAST THIS EVENING. WHILE THE FIRST
SHORT WAVE IS FCST TO MOVE QUICKLY NE WARD... THE SECOND MOVES TO
NV BY 12Z SAT AND THEN NE WARD WITH SIGNIFICANT IMPACT ON OUR CWFA.
AS THE SHORT WAVE APPROACHES...SFC CYCLOGENESIS IS FCST OVER CO.
THE LOW MOVES TO NORTH EAST NE BY 12Z SUN WITH A LARGE AREA OF
500MB Q VECTOR CONVERGENCE GIVING SUPPORT FOR PRECIP NORTH OF THE
LOW CENTER. UPPER SUPPORT FOR ASCENT AR IVES OVER OUR AREA BY 12Z
SAT WELL IN ADVANCE OF THE STRONG SHORT WAVE AND SFC CYCLOGENESIS. THE
700 MB LOW IS FCST TO MOVE NE WARD ACROSS THE SE PORTION OF OUR
CWA ON A TRACK THAT WOULD BE IDEAL FOR HEAVY SNOW IF TEMPS WERE A
BIT COLDER.
EARLIER CONVECTION THAT FORMED OVER WRN SD THIS AFTERNOON HAS
MOVED E WARD OUT OF THE CWFA. A WEAK AREA OF Q VECTOR CONVERGENCE
IS FCST TO MOVE QUICKLY OVER THE SRN PORTIONS OF THE CWFA THIS
MORNING GIVING A SLIGHT CHANCE FOR SHOWERS. MORE WIDESPREAD PRECIP
IS FCST TO DEVELOP OVER THE SRN PORTIONS OF OUR AREA WITH LARGE
SCALE ASCENT ON SATURDAY MORNING CONTINUING INTO SUNDAY. SOME
SNOW IS LIKELY OVER THE HIGHER ELEVATIONS OF THE BLACK HILLS.
MODELS ARE NOT IN GOOD AGREEMENT THIS MORNING AS TO HOW MUCH...WE
HAVE ABOUT 2 INCHES MAX IN PRESENT FCSTS. UNCERTAINTY ABOUT BOTH
PRECIP AMOUNTS AND TEMPS PREVENTS A FORECAST OF HIGHER
AMOUNTS AT THIS TIME...BUT THEY ARE POSSIBLE.
TEMPS PRETTY MUCH IN LINE WITH MAV AND MET GUIDANCE.
EXTENDED...A SERIES OF WEAK WAVES IN WESTERLY FLOW ALOFT WILL BRING
JUST A SLIGHT CHANCE OF SHOWERS TO VARIOUS PARTS OF THE AREA FROM
MONDAY THROUGH THURSDAY. EXTENDED MODELS DIFFER ON THE TIMING OF THE
WAVES SO WILL CONTINUE WITH A BLENDED SOLUTION FOR NOW. HIGH
TEMPERATURES WILL BE ONLY SLIGHTLY COOLER THAN NORMAL ON MONDAY...IN
THE UPPER 40S TO THE MID 50S ON THE PLAINS...WARMING INTO THE LOWER
60S TO LOWER 70S FOR WEDNESDAY AND THURSDAY.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...BUNKERS
LONG TERM....01
AVIATION...01
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1239 PM CDT FRI APR 13 2012
.AVIATION...
A COUPLE ITEMS WORTH MENTIONING THIS ISSUANCE. THIS AFTERNOON TSTM
CHANCES /SOME SEVERE/ WILL BE POSSIBLE UP NEAR KCDS ALONG AND EAST
OF DRYLINE. THIS DRYLINE IS EXPECTED TO RETREAT THIS EVENING AND
WE COULD SEE STORMS CONTINUING ALONG IT WELL INTO THE EVENING
HOURS THOUGH UNCERTAINTY IN THIS SCENARIO IS A BIT HIGHER THAN WE
WOULD LIKE TO CONTINUE MENTION IN THE TAF ALL EVENING. BREEZY
SOUTHWESTERLY WINDS AT KLBB SHOULD NOT BE MUCH OF AN IMPACT AT
KLBB DESPITE ABSENCE OF RWY 26 FROM THEIR PORTFOLIO. ON
SATURDAY...LATE MORNING ONWARD...WINDY CONDITIONS EXPECTED ALONG
WITH BLDU POTENTIAL AT KLBB.
&&
.PREV DISCUSSION... /ISSUED 1131 AM CDT FRI APR 13 2012/
UPDATE...
DRYLINE HAS ACCELERATED ITS EASTWARD MOTION MAINLY ACROSS THE
SOUTHERN ZONES THIS MORNING THOUGH THE BEHAVIOR ON THE NORTHERN
EXTENT REMAINS MORE COMPLEX. MODEL GUIDANCE DEPICTS SCENARIO
WHEREBY THE DRYLINE MAY REMAIN HINGED IN THE EASTERN TEXAS
PANHANDLE WITH THE DRYLINE ACROSS THE SOUTHERN ZONES SWINGING
EASTWARD YIELDING A MORE N/S ORIENTATION TO THE DRYLINE...AND THUS
MORE NORMAL TO THE UPPER LEVEL FLOW. WHILE THE THREAT LOOKS TO
REMAIN ACROSS THE FAR EASTERN ZONES...THERE REMAINS A FAIR BIT OF
UNCERTAINTY TO THE EASTERN PROGRESSION OF THE DRYLINE. LATEST
SURFACE AND RUC ANALYSIS SHOWS POSITIVE ENERGY ALREADY UP IN THE
3KJ/KG VICINITY AND CU FIELD CONTINUES TO INCREASE IN
INVIGORATION. THUS...HAVE UPPED POPS OUT EAST THIS AFTERNOON WITH
MENTION OF SVR. WHILE SHEAR REMAINS QUITE ANEMIC...INSTABILTY
COULD CERTAINLY SUPPORT PULSE SEVERE ACTIVITY WITH THE ATTENDANT
HAIL/WIND THREAT. FOR SEVERAL DAYS...GUIDANCE HAS INDICATED A
FAIRLY PRONOUNCED DRYLINE RETREAT THIS EVENING WITH THE POTENTIAL
FOR STORM DEVELOPMENT THIS EVENING AND OVERNIGHT. WATER VAPOR
IMAGERY SUGGEST THAT THERE WILL BE PERIOD OF SUBTLE LIFT TONIGHT
BUT WILL ADDRESS THAT IN THIS AFTERNOONS PACKAGE.
AFTER COORDINATION WITH TFS...WILL LIKELY GO AHEAD AND ISSUE FIRE
WEATHER WATCH OUT WEST FOR SATURDAY AS THE FUELS LOOK SUFFICIENTLY
DRY GIVEN TOMORROW WIND AND RH SPEEDS TO SATISFY CRITICAL FIRE WEATHER.
PREV DISCUSSION... /ISSUED 640 AM CDT FRI APR 13 2012/
AVIATION...
RETREATING DRYLINE HAS STALLED JUST NORTHWEST OF THE TERMINALS
THIS MORNING AND HAS SUPPORTED LIGHT FOG AND SCT-BKN MVFR CLOUD
DEVELOPMENT FROM GNC NORTHEAST TO LBB AND CDS. DRIER AIR IS NUDGING
EAST NEAR LBB AND THIS WILL RID MVFR CONDITIONS SHORTLY WITH VFR
LEVELS RETURNING TO CDS AROUND 14Z.
DRYLINE WILL MIX TO BETWEEN LBB AND CDS BY MIDDAY AT WHICH POINT
ISOLATED TSRA SHOULD DEVELOP. A FEW OF THE MOST RECENT MODELS ARE
MORE AGGRESSIVE WITH A DRYLINE BULGE NEAR CDS BY 00Z AND THIS
WOULD FAVOR HIGHER TSRA PROBS...BUT WILL LEAVE THIS OPTION TO
LATER TAFS AS THIS THREAT IS STILL 12 HOURS OUT. RATHER STRONG
WIND SHEAR AND AMPLE INSTABILITY COULD EASILY GARNER +TSRAGR
ANYWHERE IN THE VICINITY OF CDS UNTIL CONVECTION SHIFTS NORTH-
NORTHEAST AFTER SUNSET. COULD ALSO SEE MVFR CIGS MAKE A RETURN
LATE IN THIS TAF CYCLE AT BOTH CDS AND LBB AS THE DRYLINE
RETREATS.
PREV DISCUSSION... /ISSUED 412 AM CDT FRI APR 13 2012/
SHORT TERM...
SHORTWAVE TROUGH LIFTING NORTHEAST ACROSS THE CENTRAL HIGH PLAINS
AT 08Z WAS FOUND DRIVING A DIFFUSE COLD FRONT EASTWARD ACROSS THE
TX PANHANDLE AND NWRN SOUTH PLAINS WEST OF A STALLING DRYLINE.
THIS WEAK FRONT WILL RETREAT NORTH BY MIDDAY AS LEE CYCLOGENESIS
ORGANIZES IN SERN COLORADO. ASSOCIATED TROUGHING SOUTH OF THIS LOW
INTO ERN NM WILL TEND TO BACK 850-700MB WINDS FAVORING A LATE AFTN
DRYLINE POSITION ALONG OR JUST EAST OF THE CAPROCK ESCARPMENT.
CONVERGENCE HOWEVER ALONG THE DRYLINE WILL BE HINDERED SOMEWHAT BY
THIS SUBTLE BACKING OF WINDS ALOFT...THEREFORE SOME DOUBT IS CAST
REGARDING TSTRM INITIATION. AVAILABLE FORCING OUTSIDE OF THE
DRYLINE IS MINIMAL. ONE IMPULSE ALOFT IS EVIDENT ON WATER VAPOR
IMAGERY ACROSS SRN NM THIS MORNING...HOWEVER THIS WILL PASS BEFORE
MIDDAY LEAVING THE SOUTH PLAINS TO CONTEND WITH WEAK SUBSIDENCE
ALOFT. IN SPITE OF THESE NEGATIVE FACTORS THE EML IS NOT PROGGED
TO INTENSIFY AND LL MOISTURE WILL BE DEEPER THAN YESTERDAY. GFS
AGAIN APPEARS OVERDONE WITH PRECIP COVERAGE WITH MORE CREDIBILITY
OFFERED BY THE NAM. INTERESTINGLY...THE TTU WRF HAS PERFORMED
ADMIRABLY IN RECENT DAYS REGARDING CI AND THE 00Z SOLUTION IS
CREDIBLE WITH ISO-WIDELY SCTD SMALL SHRA/TSTRMS GIVEN OVERALL WEAK
BACKGROUND FORCING. HAVE THEREFORE INTRODUCED ISO TSTRMS OFF THE
CAPROCK AFTER 20Z. DESPITE ENHANCED HAIL PROBS PER SWODY1...SEVERE
THREAT REMAINS ISOLATED AND CONDITIONAL ENOUGH TO OMIT MENTION
FROM THE GRIDS.
STRENGTHENING WAA ALONG THE NOSE OF A NOCTURNAL LLJ WILL ACT TO
FOCUS POP CHANCES FARTHER N-NE TONIGHT...PERHAPS GRAZING OUR NERN
COUNTIES AFTER MIDNIGHT. EARLIER WOES WITH THE GFS EXTEND INTO THE
OVERNIGHT WITH LITTLE/NO CREDIBILITY GIVEN TO ITS ROBUST DRYLINE
CONVERGENCE ACROSS THE SWRN SOUTH PLAINS AND SUBSEQUENT CONVECTIVE
SIGNALS LINGERING THROUGH SAT MORNING.
LONG TERM...
SATURDAY IS CONTINUING TO SHAPE UP AS A DEFINITE BREEZY AND
POSSIBLY EVEN WINDY DAY ACROSS THE REGION AS THE UPPER LEVEL LOW
APPROACHES THE FOUR CORNERS REGION AND A TIGHT PRESSURE GRADIENT
DEVELOPS AT THE SURFACE. BOTH THE NAM AND GFS MOS GUIDANCE ARE NOW
PUSHING SUSTAINED WIND SPEEDS SATURDAY AFTERNOON INTO THE 35 TO 45
MPH RANGE ON THE CAPROCK. ALTHOUGH THERE HAS BEEN SOME RECENT
RAINFALL...EXPECT THESE KIND OF WIND SPEEDS TO STIR UP SOME
BLOWING DUST. ALTHOUGH WIND SPEEDS WILL DEFINITELY BE FAIRLY
STRONG TOMORROW...FEEL THAT THEY MAY NOT BE QUITE AS HIGH AS
GUIDANCE VALUES ARE INDICATING BUT DID INCREASE WIND SPEEDS IN THE
GRIDS BY ABOUT 3-5 KTS OVER THE NAM SURFACE WIND SPEEDS.
ANOTHER ISSUE WILL BE HOW FAR WEST THE DRYLINE WILL MIX. MODELS
CURRENTLY STALL OUT THE DRYLINE OVER THE EASTERN ROLLING PLAINS
WHICH WILL MEAN THAT MUCH OF THE AREA WILL NOT SEE PRECIPITATION.
IF WIND SPEEDS TO INCREASE INTO THE 40 TO 50 MPH...DRYLINE MAY
ALSO PUSH A BIT FURTHER EAST THAN THE MODELS ARE INDICATING.
SHOULD STORMS DEVELOP IN THE VICINITY OF THE DRYLINE LATE SATURDAY
AFTERNOON...THEY SHOULD RAPIDLY MOVE OFF TO THE NORTHEAST SO
COVERAGE AND INTENSITY OF STORMS SHOULD BE FAIRLY LIMITED.
THE CLOSED LOW WILL OPEN UP INTO A POSITIVELY TILTED WAVE DURING
THE DAY SUNDAY AND CONTINUE TO PUSH TOWARDS THE CENTRAL PLAINS.
THE HEIGHT GRADIENT ALOFT REMAINS SOMEWHAT TIGHT BUT NOT AS STRONG
AS ON SATURDAY SO WIND SPEEDS WILL STILL RAMP UP A BIT...
ESPECIALLY IN THE AFTERNOON WITH DAYTIME MIXING TAKING PLACE. A
WEAK COLD FRONT WILL THEN PUSH INTO THE AREA DURING THE OVERNIGHT
HOURS SUNDAY INTO MONDAY WITH MUCH LIGHTER WIND SPEEDS AND
TEMPERATURES A BIT COOLER ON BOTH SUNDAY AND MONDAY. MODELS THEN
DEVELOP WEAK NORTHWESTERLY TO ZONAL FLOW THROUGH MUCH OF NEXT WEEK
WHICH WILL FAVOR TEMPERATURES NEAR NORMAL AND A DIFFUSE SLOSHING
DRYLINE SETUP AS WELL. A DRY FORECAST ALSO LOOKS TO BE IN STORE AS
LITTLE IN THE WAY OF DISTURBANCES WILL MOVE OVER THE REGION AND A
LACK OF SURFACE CONVERGENCE ALONG THE DRYLINE WILL KEEP CONVECTION
FROM DEVELOPING.
JORDAN
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 79 48 76 38 62 / 0 0 0 10 10
TULIA 83 55 78 39 67 / 0 10 10 10 10
PLAINVIEW 83 56 81 40 67 / 0 10 0 10 10
LEVELLAND 83 53 80 42 67 / 10 10 0 10 10
LUBBOCK 85 57 81 42 69 / 10 10 0 10 10
DENVER CITY 83 51 80 44 68 / 10 10 0 10 10
BROWNFIELD 85 55 82 45 68 / 10 10 0 10 10
CHILDRESS 85 63 84 52 75 / 20 20 10 20 10
SPUR 86 63 86 50 74 / 20 20 10 20 10
ASPERMONT 85 63 88 56 76 / 20 20 10 20 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
26/99/99
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1131 AM CDT FRI APR 13 2012
.UPDATE...
DRYLINE HAS ACCELERATED ITS EASTWARD MOTION MAINLY ACROSS THE
SOUTHERN ZONES THIS MORNING THOUGH THE BEHAVIOR ON THE NORTHERN
EXTENT REMAINS MORE COMPLEX. MODEL GUIDANCE DEPICTS SCENARIO
WHEREBY THE DRYLINE MAY REMAIN HINGED IN THE EASTERN TEXAS
PANHANDLE WITH THE DRYLINE ACROSS THE SOUTHERN ZONES SWINGING
EASTWARD YIELDING A MORE N/S ORIENTATION TO THE DRYLINE...AND THUS
MORE NORMAL TO THE UPPER LEVEL FLOW. WHILE THE THREAT LOOKS TO
REMAIN ACROSS THE FAR EASTERN ZONES...THERE REMAINS A FAIR BIT OF
UNCERTAINTY TO THE EASTERN PROGRESSION OF THE DRYLINE. LATEST
SURFACE AND RUC ANALYSIS SHOWS POSITIVE ENERGY ALREADY UP IN THE
3KJ/KG VICINITY AND CU FIELD CONTINUES TO INCREASE IN
INVIGORATION. THUS...HAVE UPPED POPS OUT EAST THIS AFTERNOON WITH
MENTION OF SVR. WHILE SHEAR REMAINS QUITE ANEMIC...INSTABILTY
COULD CERTAINLY SUPPORT PULSE SEVERE ACTIVITY WITH THE ATTENDANT
HAIL/WIND THREAT. FOR SEVERAL DAYS...GUIDANCE HAS INDICATED A
FAIRLY PRONOUNCED DRYLINE RETREAT THIS EVENING WITH THE POTENTIAL
FOR STORM DEVELOPMENT THIS EVENING AND OVERNIGHT. WATER VAPOR
IMAGERY SUGGEST THAT THERE WILL BE PERIOD OF SUBTLE LIFT TONIGHT
BUT WILL ADDRESS THAT IN THIS AFTERNOONS PACKAGE.
AFTER COORDINATION WITH TFS...WILL LIKELY GO AHEAD AND ISSUE FIRE
WEATHER WATCH OUT WEST FOR SATURDAY AS THE FUELS LOOK SUFFICIENTLY
DRY GIVEN TOMORROW WIND AND RH SPEEDS TO SATISFY CRITICAL FIRE WEATHER.
&&
.PREV DISCUSSION... /ISSUED 640 AM CDT FRI APR 13 2012/
AVIATION...
RETREATING DRYLINE HAS STALLED JUST NORTHWEST OF THE TERMINALS
THIS MORNING AND HAS SUPPORTED LIGHT FOG AND SCT-BKN MVFR CLOUD
DEVELOPMENT FROM GNC NORTHEAST TO LBB AND CDS. DRIER AIR IS NUDGING
EAST NEAR LBB AND THIS WILL RID MVFR CONDITIONS SHORTLY WITH VFR
LEVELS RETURNING TO CDS AROUND 14Z.
DRYLINE WILL MIX TO BETWEEN LBB AND CDS BY MIDDAY AT WHICH POINT
ISOLATED TSRA SHOULD DEVELOP. A FEW OF THE MOST RECENT MODELS ARE
MORE AGGRESSIVE WITH A DRYLINE BULGE NEAR CDS BY 00Z AND THIS
WOULD FAVOR HIGHER TSRA PROBS...BUT WILL LEAVE THIS OPTION TO
LATER TAFS AS THIS THREAT IS STILL 12 HOURS OUT. RATHER STRONG
WIND SHEAR AND AMPLE INSTABILITY COULD EASILY GARNER +TSRAGR
ANYWHERE IN THE VICINITY OF CDS UNTIL CONVECTION SHIFTS NORTH-
NORTHEAST AFTER SUNSET. COULD ALSO SEE MVFR CIGS MAKE A RETURN
LATE IN THIS TAF CYCLE AT BOTH CDS AND LBB AS THE DRYLINE
RETREATS.
PREV DISCUSSION... /ISSUED 412 AM CDT FRI APR 13 2012/
SHORT TERM...
SHORTWAVE TROUGH LIFTING NORTHEAST ACROSS THE CENTRAL HIGH PLAINS
AT 08Z WAS FOUND DRIVING A DIFFUSE COLD FRONT EASTWARD ACROSS THE
TX PANHANDLE AND NWRN SOUTH PLAINS WEST OF A STALLING DRYLINE.
THIS WEAK FRONT WILL RETREAT NORTH BY MIDDAY AS LEE CYCLOGENESIS
ORGANIZES IN SERN COLORADO. ASSOCIATED TROUGHING SOUTH OF THIS LOW
INTO ERN NM WILL TEND TO BACK 850-700MB WINDS FAVORING A LATE AFTN
DRYLINE POSITION ALONG OR JUST EAST OF THE CAPROCK ESCARPMENT.
CONVERGENCE HOWEVER ALONG THE DRYLINE WILL BE HINDERED SOMEWHAT BY
THIS SUBTLE BACKING OF WINDS ALOFT...THEREFORE SOME DOUBT IS CAST
REGARDING TSTRM INITIATION. AVAILABLE FORCING OUTSIDE OF THE
DRYLINE IS MINIMAL. ONE IMPULSE ALOFT IS EVIDENT ON WATER VAPOR
IMAGERY ACROSS SRN NM THIS MORNING...HOWEVER THIS WILL PASS BEFORE
MIDDAY LEAVING THE SOUTH PLAINS TO CONTEND WITH WEAK SUBSIDENCE
ALOFT. IN SPITE OF THESE NEGATIVE FACTORS THE EML IS NOT PROGGED
TO INTENSIFY AND LL MOISTURE WILL BE DEEPER THAN YESTERDAY. GFS
AGAIN APPEARS OVERDONE WITH PRECIP COVERAGE WITH MORE CREDIBILITY
OFFERED BY THE NAM. INTERESTINGLY...THE TTU WRF HAS PERFORMED
ADMIRABLY IN RECENT DAYS REGARDING CI AND THE 00Z SOLUTION IS
CREDIBLE WITH ISO-WIDELY SCTD SMALL SHRA/TSTRMS GIVEN OVERALL WEAK
BACKGROUND FORCING. HAVE THEREFORE INTRODUCED ISO TSTRMS OFF THE
CAPROCK AFTER 20Z. DESPITE ENHANCED HAIL PROBS PER SWODY1...SEVERE
THREAT REMAINS ISOLATED AND CONDITIONAL ENOUGH TO OMIT MENTION
FROM THE GRIDS.
STRENGTHENING WAA ALONG THE NOSE OF A NOCTURNAL LLJ WILL ACT TO
FOCUS POP CHANCES FARTHER N-NE TONIGHT...PERHAPS GRAZING OUR NERN
COUNTIES AFTER MIDNIGHT. EARLIER WOES WITH THE GFS EXTEND INTO THE
OVERNIGHT WITH LITTLE/NO CREDIBILITY GIVEN TO ITS ROBUST DRYLINE
CONVERGENCE ACROSS THE SWRN SOUTH PLAINS AND SUBSEQUENT CONVECTIVE
SIGNALS LINGERING THROUGH SAT MORNING.
LONG TERM...
SATURDAY IS CONTINUING TO SHAPE UP AS A DEFINITE BREEZY AND
POSSIBLY EVEN WINDY DAY ACROSS THE REGION AS THE UPPER LEVEL LOW
APPROACHES THE FOUR CORNERS REGION AND A TIGHT PRESSURE GRADIENT
DEVELOPS AT THE SURFACE. BOTH THE NAM AND GFS MOS GUIDANCE ARE NOW
PUSHING SUSTAINED WIND SPEEDS SATURDAY AFTERNOON INTO THE 35 TO 45
MPH RANGE ON THE CAPROCK. ALTHOUGH THERE HAS BEEN SOME RECENT
RAINFALL...EXPECT THESE KIND OF WIND SPEEDS TO STIR UP SOME
BLOWING DUST. ALTHOUGH WIND SPEEDS WILL DEFINITELY BE FAIRLY
STRONG TOMORROW...FEEL THAT THEY MAY NOT BE QUITE AS HIGH AS
GUIDANCE VALUES ARE INDICATING BUT DID INCREASE WIND SPEEDS IN THE
GRIDS BY ABOUT 3-5 KTS OVER THE NAM SURFACE WIND SPEEDS.
ANOTHER ISSUE WILL BE HOW FAR WEST THE DRYLINE WILL MIX. MODELS
CURRENTLY STALL OUT THE DRYLINE OVER THE EASTERN ROLLING PLAINS
WHICH WILL MEAN THAT MUCH OF THE AREA WILL NOT SEE PRECIPITATION.
IF WIND SPEEDS TO INCREASE INTO THE 40 TO 50 MPH...DRYLINE MAY
ALSO PUSH A BIT FURTHER EAST THAN THE MODELS ARE INDICATING.
SHOULD STORMS DEVELOP IN THE VICINITY OF THE DRYLINE LATE SATURDAY
AFTERNOON...THEY SHOULD RAPIDLY MOVE OFF TO THE NORTHEAST SO
COVERAGE AND INTENSITY OF STORMS SHOULD BE FAIRLY LIMITED.
THE CLOSED LOW WILL OPEN UP INTO A POSITIVELY TILTED WAVE DURING
THE DAY SUNDAY AND CONTINUE TO PUSH TOWARDS THE CENTRAL PLAINS.
THE HEIGHT GRADIENT ALOFT REMAINS SOMEWHAT TIGHT BUT NOT AS STRONG
AS ON SATURDAY SO WIND SPEEDS WILL STILL RAMP UP A BIT...
ESPECIALLY IN THE AFTERNOON WITH DAYTIME MIXING TAKING PLACE. A
WEAK COLD FRONT WILL THEN PUSH INTO THE AREA DURING THE OVERNIGHT
HOURS SUNDAY INTO MONDAY WITH MUCH LIGHTER WIND SPEEDS AND
TEMPERATURES A BIT COOLER ON BOTH SUNDAY AND MONDAY. MODELS THEN
DEVELOP WEAK NORTHWESTERLY TO ZONAL FLOW THROUGH MUCH OF NEXT WEEK
WHICH WILL FAVOR TEMPERATURES NEAR NORMAL AND A DIFFUSE SLOSHING
DRYLINE SETUP AS WELL. A DRY FORECAST ALSO LOOKS TO BE IN STORE AS
LITTLE IN THE WAY OF DISTURBANCES WILL MOVE OVER THE REGION AND A
LACK OF SURFACE CONVERGENCE ALONG THE DRYLINE WILL KEEP CONVECTION
FROM DEVELOPING.
JORDAN
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 79 48 76 38 62 / 0 0 0 10 10
TULIA 83 55 78 39 67 / 0 10 10 10 10
PLAINVIEW 83 56 81 40 67 / 0 10 0 10 10
LEVELLAND 83 53 80 42 67 / 10 10 0 10 10
LUBBOCK 85 57 81 42 69 / 10 10 0 10 10
DENVER CITY 83 51 80 44 68 / 10 10 0 10 10
BROWNFIELD 85 55 82 45 68 / 10 10 0 10 10
CHILDRESS 85 63 84 52 75 / 20 20 10 20 10
SPUR 86 63 86 50 74 / 20 20 10 20 10
ASPERMONT 85 63 88 56 76 / 20 20 10 20 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
26/99