Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 03/31/12
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1140 AM MDT THU MAR 29 2012
.UPDATE...
ISSUED AT 1130 AM MDT THU MAR 29 2012
CURRENT OBSERVATIONS SHOW ONLY FAIR WEATHER CUMULUS OVER THE
FORECAST AREA AT THIS TIME WITH NO SHOWERS NOTED. BASED ON THIS AND
SHORT TERM MODELS INDICATING VERY LIMITED QPF CHANCES FOR THE
AFTERNOON...DECIDED TO LOWER THE REMAINING POPS TO ISOLATED
COVERAGE OVER THE NORTHERN MOUNTAINS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 438 AM MDT THU MAR 29 2012
AT 3 AM THE COLD FRONT WAS ACROSS THE NW HALF OF THE FORECAST AREA
AND SAGGING SOUTH. DEWPOINTS CLIMBING FROM TEENS TO 20-30S WITH
THE FRONT. ONLY LIGHT SHOWERS HAVE BEEN CAUGHT BY SURFACE
REPORTING STATIONS IN THE PARK AND ELK MOUNTAINS. GENERALLY
FOLLOWED THE HRRR LIGHT PRECIP PATTERN FOR THIS MORNING. THE WEAK
COLD CORE BRUSHES THE NORTH THIS MORNING WITH MARGINAL INSTABILITY
SHRINKING INTO THE EARLY AFTERNOON. OTHERWISE TEMPERATURES WILL BE
3-5 DEGREES COOLER THAN ON WEDNESDAY BUT WILL STILL BE WELL ABOVE
NORMAL. WINDS WILL VEER TO NW BEHIND THE FRONT AND DIMINISH
THROUGH THE AFTERNOON.
A SECOND WEAK WAVE PROGGED TO PASS THIS EVENING BUT LOOKS MOISTURE
STARVED BELOW 500MB. SO LOWERED POPS FOR THIS EVENING. THE MID-
HIGH CLOUDS WILL SHIFT EAST AFTER MIDNIGHT BUT MAY LIMIT THE LOW
TEMPERATURES OVERNIGHT ESPECIALLY IN WESTERN COLORADO. WARMING
TREND BEGINS ON FRIDAY IN A FLAT BENIGN FLOW.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 438 AM MDT THU MAR 29 2012
DRY AND UNSEASONABLY WARM WEATHER WILL CONTINUE INTO THE EARLY
PART OF THE WEEKEND AS FLOW SHIFTS TO THE SOUTHWEST AHEAD OF AN
APPROACHING PACIFIC TROUGH. IN FACT...INDICATIONS ARE THAT HIGHS
WILL BE NEAR RECORD LEVELS. A TIGHTENING PRESSURE GRADIENT WILL
GENERATE STRONG AND GUSTY SOUTHWEST WINDS WHICH WILL NOT ONLY HELP
LIFT HIGHS NEARLY 20 DEGREES ABOVE NORMAL BUT WILL ALSO DRIVE RH
DOWN...POTENTIALLY YIELDING CRITICAL FIRE WEATHER CONDITIONS.
MODELS WERE CONSISTENT IN MOVING THE TROUGH OVER THE GREAT BASIN
SATURDAY NIGHT. THE COLD FRONT ASSOCIATED WITH THIS SYSTEM IS
EXPECTED TO JUST REACH THE GREEN RIVER SUNDAY MORNING. PRE-
FRONTAL WINDS WILL CONTINUE MUCH OF THE NIGHT HELPING TO BUOY
OVERNIGHT LOWS. PRECIPITATION WILL LARGELY HOLD OFF UNTIL THE
FRONT SWEEPS ACROSS THE REGION SUNDAY. SNOW LEVELS WILL BEGIN NEAR
THE TREE-LINE...LOWERING WITH FROPA TO VALLEY FLOORS ACROSS THE
NORTH AND THE HIGHER CENTRAL VALLEYS. LATEST SNOWFALL OUTPUT
SUGGESTS AMOUNTS WILL LARGELY BE BELOW ADVISORY LEVELS...THOUGH
BLOWING SNOW AND REDUCED VISIBILITY COULD CREATE SOME TRAVEL
DIFFICULTIES. CLOUDS...SHOWERS AND CAA BEHIND THE FRONT WILL
RESULT IN MUCH COOLER TEMPERATURES SUNDAY...THOUGH STILL JUST A
BIT ABOVE NORMAL.
SNOW IS EXPECTED TO LINGER ALONG THE CONTINENTAL DIVIDE SUNDAY
NIGHT...LIKELY ENDING BY MONDAY MORNING. TEMPERATURES WILL REMAIN
COOL MONDAY UNDER A NORTHWEST FLOW REGIME. LOOK FOR A WARMING
TREND FOR THE MIDDLE OF THE WEEK AS FLOW BECOMES ZONAL TUESDAY
...THEN SHIFTS TO THE SOUTHWEST WEDNESDAY. DRY CONDITIONS ARE
EXPECTED THROUGH MIDWEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1130 AM MDT THU MAR 29 2012
VFR CONDITIONS ARE EXPECTED TO PERSIST AT ALL TAF SITES THROUGH
FRIDAY MORNING.THIS MORNINGS COLD FRONT HAS DISSIPATED WITH ONLY
SCATTERED MID LEVEL CLOUDS CURRENTLY OVER SOME OF THE MOUNTAINS.
ANOTHER WEAK UPPER LEVEL WAVE WILL PASS THROUGH THIS EVENING
BRINGING WITH IT AN INCREASE IN UPPER/MID LEVEL CLOUDS BEGINNING
THIS AFTERNOON. CLOUDS WILL BE AROUND THROUGH THE FIRST HALF OF
TONIGHT WITH A FEW LIGHT SHOWERS POSSIBLE OVER THE FAR NORTHERN
MOUNTAINS FOLLOWED BY CLEARING EARLY ON FRIDAY.
&&
.FIRE WEATHER...
ISSUED AT 438 AM MDT THU MAR 29 2012
A PACIFIC TROUGH WILL MOVE INTO THE WESTERN GREAT BASIN SATURDAY
RESULTING IN A SHIFT TO SOUTHWEST FLOW. A TIGHTENING PRESSURE
GRADIENT COMBINED WITH NEAR RECORD WARMTH WILL HELP MIX STRONG
WINDS ALOFT TO THE SURFACE DURING THE AFTERNOON AND EVENING. THE
DEEP MIXING WILL ALSO SERVE TO REDUCE RELATIVE HUMIDITY BELOW 15
PERCENT ACROSS MUCH OF THE REGION DURING PEAK HEATING. THAT
SAID...NOT COMFORTABLE ISSUING FIRE WEATHER WATCH FOR THE LATE 5TH
AND 6TH PERIODS AND WILL LET LATER SHIFTS PULL THE TRIGGER AS THE
DETAILS COME TOGETHER.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...TB/JAD
SHORT TERM.....JOE
LONG TERM......NL
AVIATION...TB/JAD
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
438 AM MDT THU MAR 29 2012
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 438 AM MDT THU MAR 29 2012
AT 3 AM THE COLD FRONT WAS ACROSS THE NW HALF OF THE FORECAST AREA
AND SAGGING SOUTH. DEWPOINTS CLIMBING FROM TEENS TO 20-30S WITH
THE FRONT. ONLY LIGHT SHOWERS HAVE BEEN CAUGHT BY SURFACE
REPORTING STATIONS IN THE PARK AND ELK MOUNTAINS. GENERALLY
FOLLOWED THE HRRR LIGHT PRECIP PATTERN FOR THIS MORNING. THE WEAK
COLD CORE BRUSHES THE NORTH THIS MORNING WITH MARGINAL INSTABILITY
SHRINKING INTO THE EARLY AFTERNOON. OTHERWISE TEMPERATURES WILL BE
3-5 DEGREES COOLER THAN ON WEDNESDAY BUT WILL STILL BE WELL ABOVE
NORMAL. WINDS WILL VEER TO NW BEHIND THE FRONT AND DIMINISH
THROUGH THE AFTERNOON.
A SECOND WEAK WAVE PROGGED TO PASS THIS EVENING BUT LOOKS MOISTURE
STARVED BELOW 500MB. SO LOWERED POPS FOR THIS EVENING. THE MID-
HIGH CLOUDS WILL SHIFT EAST AFTER MIDNIGHT BUT MAY LIMIT THE LOW
TEMPERATURES OVERNIGHT ESPECIALLY IN WESTERN COLORADO. WARMING
TREND BEGINS ON FRIDAY IN A FLAT BENIGN FLOW.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 438 AM MDT THU MAR 29 2012
DRY AND UNSEASONABLY WARM WEATHER WILL CONTINUE INTO THE EARLY
PART OF THE WEEKEND AS FLOW SHIFTS TO THE SOUTHWEST AHEAD OF AN
APPROACHING PACIFIC TROUGH. IN FACT...INDICATIONS ARE THAT HIGHS
WILL BE NEAR RECORD LEVELS. A TIGHTENING PRESSURE GRADIENT WILL
GENERATE STRONG AND GUSTY SOUTHWEST WINDS WHICH WILL NOT ONLY HELP
LIFT HIGHS NEARLY 20 DEGREES ABOVE NORMAL BUT WILL ALSO DRIVE RH
DOWN...POTENTIALLY YIELDING CRITICAL FIRE WEATHER CONDITIONS.
MODELS WERE CONSISTENT IN MOVING THE TROUGH OVER THE GREAT BASIN
SATURDAY NIGHT. THE COLD FRONT ASSOCIATED WITH THIS SYSTEM IS
EXPECTED TO JUST REACH THE GREEN RIVER SUNDAY MORNING. PRE-
FRONTAL WINDS WILL CONTINUE MUCH OF THE NIGHT HELPING TO BUOY
OVERNIGHT LOWS. PRECIPITATION WILL LARGELY HOLD OFF UNTIL THE
FRONT SWEEPS ACROSS THE REGION SUNDAY. SNOW LEVELS WILL BEGIN NEAR
THE TREE-LINE...LOWERING WITH FROPA TO VALLEY FLOORS ACROSS THE
NORTH AND THE HIGHER CENTRAL VALLEYS. LATEST SNOWFALL OUTPUT
SUGGESTS AMOUNTS WILL LARGELY BE BELOW ADVISORY LEVELS...THOUGH
BLOWING SNOW AND REDUCED VISIBILITY COULD CREATE SOME TRAVEL
DIFFICULTIES. CLOUDS...SHOWERS AND CAA BEHIND THE FRONT WILL
RESULT IN MUCH COOLER TEMPERATURES SUNDAY...THOUGH STILL JUST A
BIT ABOVE NORMAL.
SNOW IS EXPECTED TO LINGER ALONG THE CONTINENTAL DIVIDE SUNDAY
NIGHT...LIKELY ENDING BY MONDAY MORNING. TEMPERATURES WILL REMAIN
COOL MONDAY UNDER A NORTHWEST FLOW REGIME. LOOK FOR A WARMING
TREND FOR THE MIDDLE OF THE WEEK AS FLOW BECOMES ZONAL TUESDAY
...THEN SHIFTS TO THE SOUTHWEST WEDNESDAY. DRY CONDITIONS ARE
EXPECTED THROUGH MIDWEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z EARLY FRIDAY MORNING)
ISSUED AT 438 AM MDT THU MAR 29 2012
AT 09Z A WEAK COLD FRONT WAS SOUTH OF THE I-70 CORRIDOR AND
SHIFTING EAST. CURRENT CLOUD HEIGHTS BEHIND THE FRONT ARE BETWEEN
7000 TO 10000 FT AGL FOR PREVAILING VFR CONDITIONS AT ALL TAF
SITES. LIGHT SHOWERS AND LOCALLY LOWERED CEILINGS ARE POSSIBLE
THROUGH 18Z FOR MTNS IN THE VCNTY OF KSBS SOUTH TO KEGE AND KASE.
THESE ISOLATED SHOWERS END AFTER 21Z.
&&
.FIRE WEATHER...
ISSUED AT 438 AM MDT THU MAR 29 2012
A PACIFIC TROUGH WILL MOVE INTO THE WESTERN GREAT BASIN SATURDAY
RESULTING IN A SHIFT TO SOUTHWEST FLOW. A TIGHTENING PRESSURE
GRADIENT COMBINED WITH NEAR RECORD WARMTH WILL HELP MIX STRONG
WINDS ALOFT TO THE SURFACE DURING THE AFTERNOON AND EVENING. THE
DEEP MIXING WILL ALSO SERVE TO REDUCE RELATIVE HUMIDITY BELOW 15
PERCENT ACROSS MUCH OF THE REGION DURING PEAK HEATING. THAT
SAID...NOT COMFORTABLE ISSUING FIRE WEATHER WATCH FOR THE LATE 5TH
AND 6TH PERIODS AND WILL LET LATER SHIFTS PULL THE TRIGGER AS THE
DETAILS COME TOGETHER.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM.....JOE
LONG TERM......NL
AVIATION.......JOE
FIRE WEATHER...NL
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
155 PM EDT THU MAR 29 2012
.SYNOPSIS...
18Z WATER VAPOR AND H4 RUC ANALYSIS SHOWS AND AMPLIFIED BUT
PROGRESSIVE NORTHERN STREAM FLOW. NORTHERN STREAM ARRIVES OVER THE
PACIFIC NORTHWEST COAST WITH AN ELONGATED SHORTWAVE NEAR THE
CONTINENTAL DIVIDE. THE FLOW THEN RIDGING NORTHWARD INTO
SOUTH-CENTRAL CANADA/WESTERN GREAT LAKES BEFORE DIVING BACK
SOUTHEASTWARD OVER THE NE/MID-ATLANTIC STATES. CLOSER TO HOME WE
FIND BROAD UPPER RIDGING IN PLACE OVER THE EASTERN GULF OF MEXICO
AND THE FL PENINSULA. A WEAK SHORTWAVE CURRENTLY OVER TEXAS WILL
SLOWLY MOVE EAST ALONG THE NORTHERN GULF COAST DURING THE NEXT 24-36
HOURS AND POTENTIALLY BRING AN ENHANCEMENT TO THE SHOWER/STORM
CHANCES OVER OUR NORTHERN ZONES BY FRIDAY EVENING. WV IMAGERY HAS
SHOWN GRADUAL MOISTURE ADVECTION INTO OUR REGION WITHIN THE UPPER
LEVELS. THIS TREND IS SEEN CLEARLY OVER THE PAST 24 HOURS LOOKING AT
THE KTBW SOUNDING PROFILE...WHERE DEWPOINT DEPRESSIONS HAVE
SIGNIFICANTLY DECREASED ABOVE THE H5 LEVEL. THE 12Z SOUNDING STILL
SHOWS THAT WE WERE DEALING WITH A HEALTHY LAYER OF DRY AIR/LOW
THETA-E VALUES BETWEEN 800-500MB. MODEL FORECAST SOUNDING ALL SHOW
THAT EVEN THIS LAYER WILL CONTINUE TO MOISTEN SOMEWHAT BY THE END OF
THE DAY. VISIBLE SATELLITE SHOWS A SCT-BKN CU FIELD WELL ESTABLISHED
AWAY FROM THE MORE STABILIZED BOUNDARY LAYER BEHIND THE DEVELOPING
SEA-BREEZE. THE FOCUS ALONG THE SEABREEZE COMBINED WITH THE SLIGHTLY
MORE FAVORABLE COLUMN FOR CONVECTION SHOULD STILL GIVE WAY TO
ISOLATED SHOWERS FOR THE LATE AFTERNOON/EARLY EVENING. WILL KEEP THE
SLIGHT CHANCE 20% POPS FOR THE REST OF THE DAY INLAND AND REMOVE
RAIN CHANCES FROM THE BEACHES.
AT THE SURFACE...GRADIENT IS QUITE WEAK ACROSS THE FORECAST AREA
WITH THE SUBTROPICAL RIDGE AXIS EXTENDING ACROSS THE FL PENINSULA.
CURRENT TEMPS HAVE REACHES THE LOWER 80S INLAND WITH A COUPLE
DEGREES FURTHER RISE EXPECTED. LOCAL SEA-BREEZE CIRCULATIONS WILL
HELP HOLD DOWN TEMPS A FEW DEGREES INTO THE MID/UPPER 70S AT THE
BEACHES.
.SHORT TERM (TONIGHT THROUGH SATURDAY)...
TONIGHT...
WITHOUT ANY CLEAR UPPER LEVEL SUPPORT...SHOULD SEE A FEW LINGERING
SHOWERS ONLY UNTIL AROUND 02-03Z THIS EVENING BEFORE FADING WITH THE
LOSS OF DIURNAL HEATING. THE REMAINDER OF THE NIGHT LOOKS QUIET WITH
JUST A FEW HIGHER LEVEL CLOUDS. INLAND LOW TEMPS WILL DROP TO THE
UPPER 50S/LOWER 60S...WITH MIDDLE 60S ALONG THE COAST.
FRIDAY...
SURFACE RIDGE AXIS WILL SHIFT A BIT FURTHER SOUTH ALLOWING A MORE
MOIST SOUTHWEST LOW LEVEL FLOW TO DEVELOP ACROSS THE AREA. MID/UPPER
LEVEL SHORTWAVE ENERGY WILL CONTINUE TO ADVANCE ALONG THE NORTHERN
GULF COAST AND BE APPROACHING THE NORTHERN FL PENINSULA BY EVENING.
DEEPER MOISTURE...AND WEAK OVERSPREADING SYNOPTIC SUPPORT/QG FORCING
AHEAD OF THE SHORTWAVE SHOULD SUPPORT AT LEAST ISOLATED TO WIDELY
SCT CONVECTION FOR THE AFTERNOON HOURS. HAVE NOT GONE ALL THAT
AGGRESSIVE WITH THE RAIN CHANCES WITHIN THIS FORECAST PACKAGE DUE TO
SOME MODEL DISAGREEMENT AS TO WHEN THE SYNOPTIC SUPPORT WILL
ARRIVE...HOWEVER WOULD NOT BE SURPRISED IF THESE POP NUMBERS NEEDED
TO BE RAISED. TEMPERATURES LOOK TO REMAIN ABOVE AVERAGE IN THE
MIDDLE 80S AWAY FROM THE COAST...AND MID 70S TO AROUND 80 AT THE
COAST.
FRIDAY NIGHT...
INITIAL SHORTWAVE WILL QUICKLY PASS NORTH OF THE REGION THE FIRST
HALF OF THE NIGHT WITH A WEAK SURFACE FRONT/TROUGH STALLING UP
TOWARDS THE FL PANHANDLE/NE GULF OF MEXICO. DESPITE THE WEAK FOCUS
ALONG IS BOUNDARY...GLOBAL MEMBERS/SREF SHOWING AT LEAST SOME
CONVECTION OVER THE NORTHERN HALF OF THE FORECAST AREA. FORECAST POP
GRADIENT WILL SHOW RAIN CHANCES AROUND 40% UP TOWARD LEVY COUNTY AND
TAPER DOWN TO SLIGHT CHANCE 20% AROUND THE TAMPA BAY AREA. FURTHER
SOUTH...WILL KEEP THINGS DRY FOR NOW. A WARM OVERNIGHT ON TAP WITH
THE FLOW OFF THE GULF. LOW TEMPS RANGING FROM THE LOWER 60S INLAND
TO THE MIDDLE/UPPER 60S CLOSE TO THE WATER.
SATURDAY...
EXPECTING ZONAL MID/UPPER LEVEL FLOW WITH ANY SIGNIFICANT SYNOPTIC
SUPPORT REMAINING TO OUR NORTH. AT THE SURFACE...SUBTROPICAL RIDGE
AXIS WILL HOLD TO OUR SOUTH KEEPING A MOIST WEST/SW FLOW OFF THE
GULF. WITH WESTERLY FLOW WILL AID THE INLAND SEA-BREEZE PROPAGATION
HELPING TO KEEP THE BEST SHOWER/STORM CHANCES (~30%) TO THE WEST OF
THE I-75 CORRIDOR. TEMPS FOR YET ANOTHER DAY REACHING INTO THE
MIDDLE 80S INLAND AND MID/UPPER 70S AT THE BEACHES.
&&
.LONG TERM (SATURDAY NIGHT - THURSDAY)...
FORECAST CONFIDENCE IS INCREASING AS MODELS HAVE COME MORE IN LINE
DURING THE LONG TERM PERIOD. A WEAK UPPER LEVEL SHORTWAVE WILL MOVE
OFF THE SOUTHEAST U.S. COAST SATURDAY NIGHT WITH SOME RIDGING
BUILDING OVER THE SOUTHEAST U.S. AND FLORIDA SUNDAY AND MONDAY AHEAD
OF THE NEXT TROUGH MOVING THROUGH THE CENTRAL STATES. THE SURFACE
RIDGE AXIS WILL REMAIN ACROSS SOUTH FLORIDA DURING THIS TIME
CONTINUING THE SOUTH TO SOUTHWEST FLOW ACROSS THE AREA. ENOUGH
MOISTURE COMBINED WITH SUFFICIENT INSTABILITY...DAYTIME HEATING AND
THE SEA BREEZE WILL LEAD TO A SLIGHT CHANCE OF AFTERNOON
THUNDERSTORMS...BUT THE FLOW WILL DRIVE THE WEST COAST SEA BREEZE
WELL INLAND BOTH DAYS AND THEREFORE KEEP THE BEST CHANCE OF SEEING A
SHOWER OR THUNDERSTORM OVER THE EASTERN HALF OF THE FLORIDA
PENINSULA. DURING TUESDAY AND WEDNESDAY THE NEXT TROUGH WILL MOVE
ACROSS THE EASTERN U.S. HELPING TO PUSH A COOL FRONT TOWARD THE
REGION. PRESENT GUIDANCE DOES MOVE THIS FRONT THROUGH THE AREA
TUESDAY NIGHT AND WEDNESDAY...BUT WHETHER THIS BOUNDARY ACTUALLY
MOVES ALL THE WAY THROUGH OR NOT...IT DOES LOOK LIKE THE ENTIRE
REGION WILL SEE A CHANCE OF SHOWERS AND THUNDERSTORMS TUESDAY INTO
WEDNESDAY.
TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH THE PERIOD. DAYTIME
HIGHS WILL BE MOSTLY IN THE MID TO UPPER 80S...EXCEPT CLOSE TO THE
COAST WHERE THE ONSHORE FLOW WILL KEEP READINGS IN THE UPPER 70S TO
LOWER 80S. OVERNIGHT LOWS WILL BE MOSTLY IN THE 60S...EXCEPT AROUND
70 ALONG THE COAST.
&&
.AVIATION...
A FEW SHOWERS MAY PRODUCE BRIEF MVFR CONDITIONS AT KLAL AFTER 21Z
WITH ADDITIONAL MVFR VISIBILITIES POSSIBLE AFTER 30/08Z AT KPGD AND
KLAL FROM PATCHY FOG...OTHERWISE MAINLY VFR CONDITIONS ARE EXPECTED
AT ALL TERMINAL SITES. SOUTHWEST TO WEST WINDS AROUND 10 KNOTS THIS
AFTERNOON WILL BECOME LIGHT AND VARIABLE AFTER 30/02Z TONIGHT.
&&
.MARINE...
WINDS AND SEAS ARE EXPECTED TO REMAIN GENERALLY BELOW HEADLINE
CRITERIA THROUGH FRIDAY. LOCAL SEA-BREEZE CIRCULATIONS WILL KEEP
WINDS ONSHORE THROUGH THE MIDDLE EVENING HOURS. LARGE SCALE FLOW
WILL BECOME MORE SOUTHERLY/PARALLEL TO THE COASTLINE OVERNIGHT AND
THEN VEER OUT OF THE SOUTHWEST BY THE END OF FRIDAY IN ADVANCE OF AN
APPROACHING WEAK COLD FRONT.
&&
.FIRE WEATHER...
A BRIEF PERIOD OF NEAR CRITICAL LEVELS OF RELATIVE HUMIDITY ARE
EXPECTED OVER INLAND ZONES FRIDAY AFTERNOON...HOWEVER CRITICAL
DURATIONS ARE NOT EXPECTED AND DISPERSION INDICES ARE FORECAST BELOW
75. INCREASING LOW LEVEL MOISTURE ARE EXPECTED TO PREVENT CRITICAL
LEVELS OF RELATIVE HUMIDITY DURING THE UPCOMING WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 64 83 66 83 / 15 20 20 30
FMY 63 86 65 86 / 15 20 10 10
GIF 59 86 62 86 / 20 20 15 30
SRQ 63 83 65 84 / 15 20 20 25
BKV 59 84 62 84 / 20 20 25 30
SPG 67 81 68 81 / 20 20 20 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE...14/MROCZKA
AVIATION/FIRE WEATHER...57/MCMICHAEL
LONG TERM...69/CLOSE
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
945 AM EDT THU MAR 29 2012
.UPDATE (REST OF TODAY AND TONIGHT)...
13Z WATER VAPOR AND H4 RUC ANALYSIS SHOWS AND AMPLIFIED BUT
PROGRESSIVE NORTHERN STREAM FLOW. NORTHERN STREAM ARRIVES OVER THE
PACIFIC NORTHWEST COAST WITH AN ELONGATED SHORTWAVE NEAR THE
CONTINENTAL DIVIDE. THE FLOW THEN RIDGING NORTHWARD INTO
SOUTH-CENTRAL CANADA/WESTERN GREAT LAKES BEFORE DIVING BACK
SOUTHEASTWARD OVER THE NE/MID-ATLANTIC STATES. CLOSER TO HOME WE
FIND BROAD UPPER RIDGING IN PLACE OVER THE EASTERN GULF OF MEXICO
AND THE FL PENINSULA. A WEAK SHORTWAVE CURRENTLY OVER TEXAS WILL
SLOWLY MOVE EAST ALONG THE NORTHERN GULF COAST DURING THE NEXT 24-36
HOURS AND POTENTIALLY BRING A SLIGHT ENHANCEMENT TO THE SHOWER/STORM
CHANCES OVER OUR NORTHERN ZONES FRIDAY AFTERNOON/EVENING. WV IMAGERY
HAS SHOWN GRADUAL MOISTURE ADVECTION INTO OUR REGION WITHIN THE
UPPER LEVELS. THIS TREND IS SEEN CLEARLY OVER THE PAST 24 HOURS
LOOKING AT THE KTBW SOUNDING PROFILE...WHERE DEWPOINT DEPRESSIONS
HAVE SIGNIFICANTLY DECREASED ABOVE THE H5 LEVEL. THE 12Z SOUNDING
STILL SHOWS THAT WE ARE DEALING WITH A HEALTHY LAYER OF DRY AIR
BETWEEN 800-500MB EARLY THIS MORNING. MID-LEVEL THETA-E VALUES
WITHIN THIS LAYER REMAIN BELOW 320K AND ARE RATHER HOSTILE TO DEEP
CONVECTION...HOWEVER...MODEL FORECAST SOUNDING ALL SHOW THAT EVEN
THIS LAYER WILL MOISTEN SOMEWHAT BY THE END OF THE DAY. THIS TREND
SHOULD LEAD TO AT LEAST A FEW GENERALLY LATE AFTERNOON/EVENING
SHOWERS/STORMS ASSOCIATED WITH THE LOW LEVEL FOCUS OF THE SEA-BREEZE.
AT THE SURFACE...GRADIENT IS QUITE WEAK ACROSS THE FORECAST AREA
THIS MORNING WITH THE SUBTROPICAL RIDGE AXIS EXTENDING ACROSS THE
CENTRAL FLORIDA PENINSULA. MOSTLY SUNNY SKIES ARE GIVING WAY TO
ANOTHER QUICK TEMPERATURE RISE. PAST SEVERAL DAYS...A TIGHTER
GRADIENT HAS ALLOWED FOR EXCELLENT DIURNAL MIXING UP TO AROUND THE
7KFT LEVEL. MAY NOT SEE QUITE AS EFFICIENT MIXING TODAY...BUT EVEN
6000-6500KFT WILL YIELD LATE AFTERNOON HIGH TEMPS INTO THE MIDDLE
80S INLAND. DO ANTICIPATE SEA-BREEZE CIRCULATIONS TO DEVELOP BY
EARLY AFTERNOON WITH WILL HELP HOLD DOWN TEMPS A FEW DEGREES CLOSE
TO THE COAST.
AS MENTIONED ABOVE...THIS SEA-BREEZE COMBINED WITH AN INCREASINGLY
FAVORABLE COLUMN FOR DEEP CONVECTION SHOULD YIELD ISOLATED TO WIDELY
SCATTERED SHOWERS BY LATE IN THE DAY. MANY OF THE HI-RESOLUTION
ENSEMBLE CAM (CONVECTION ALLOWING MODELS) AGREE WITH THIS SOLUTION.
AT THIS TIME THERE IS NO CLEAR BIAS NORTH TO SOUTH AS TO WHERE THE
OVERALL BEST CHANCES FOR THE "POP UP" SHOWERS WILL BE...AND WILL
LEAVE THE GENERAL 20% RAIN CHANCES INHERITED FROM THE PREVIOUS
FORECAST.
WITHOUT ANY CLEAR UPPER LEVEL SUPPORT...SHOULD SEE A FEW LINGERING
SHOWERS ONLY UNTIL AROUND 02-03Z THIS EVENING BEFORE FADING WITH THE
LOSS OF DIURNAL HEATING. THE REMAINDER OF THE NIGHT LOOKS QUIET WITH
JUST A FEW HIGHER LEVEL CLOUDS. INLAND LOW TEMPS WILL DROP TO THE
UPPER 50S/LOWER 60S...WITH MIDDLE 60S ALONG THE COAST.
&&
.AVIATION...
A FEW SHOWERS MAY DEVELOP TO THE EAST OF THE TERMINAL SITES
DURING MID TO LATE AFTERNOON...OTHERWISE VFR CONDITIONS ARE
EXPECTED DURING THE NEXT 24 HOURS. SOUTHEAST TO SOUTH WINDS
AROUND 5 KNOTS THIS MORNING...WILL BECOME SOUTHWEST TO WEST
AROUND 10 KNOTS AFTER 18Z AS THE SEA BREEZE DEVELOPS. WINDS
WILL BECOME LIGHT AND VARIABLE AFTER 30/02Z TONIGHT.
&&
.MARINE...
WINDS AND SEAS ARE EXPECTED TO REMAIN GENERALLY BELOW HEADLINE
CRITERIA THROUGH FRIDAY. LIGHT AND VARIABLE FLOW THIS MORNING WILL
TURN ONSHORE DURING THE AFTERNOON WITH THE DEVELOPMENT OF LOCAL
SEA-BREEZE CIRCULATIONS. LARGE SCALE FLOW WILL BECOME MORE
SOUTHERLY/PARALLEL TO THE COASTLINE OVERNIGHT AND THEN VEER OUT
OF THE SOUTHWEST BY THE END OF FRIDAY IN ADVANCE OF AN APPROACHING
WEAK COLD FRONT.
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/MARINE...14/MROCZKA
AVIATION...57/MCMICHAEL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
600 PM CDT THU MAR 29 2012
.UPDATE 30/00Z AVIATION DISCUSSION...
.SHORT TERM /TONIGHT/...
MAIN FOCUS IS SHOWER AND THUNDERSTORM DEVELOPMENT AS SURFACE
LOW...CURRENTLY OVER NORTHERN KANSAS MOVES ACROSS SOUTHERN IOWA
TONIGHT. WHILE THIS IS HAPPENING...A COLD FRONT ACROSS THE EASTERN
DAKOTAS INTO NEBRASKA WILL ALSO MOVE ACROSS IOWA TONIGHT...SO THERE
COULD BE TWO ROUNDS OF PRECIPITATION FOCUS. WHAT WAS TO BE A WARM
FRONT HAS REMAINED STALLED ALONG THE MISSOURI RIVER IN
MISSOURI...WITH ONLY LIMITED PUSH NORTH INTO SE NEBRASKA...DUE TO
PERSISTENT CONVECTION IN NORTHERN MISSOURI. FRONT APPEARS UNLIKELY
TO MAKE INTO IOWA UNTIL MID OR LATE EVENING...SO THE OPPORTUNITY FOR
SURFACE BASED CONVECTION AND SIGNIFICANT SEVERE WEATHER POTENTIAL
APPEARS LIMITED. LOW-LEVEL SHEAR AND HELICITY WILL BE MODERATELY
STRONG OVER THE SOUTHWESTERN FORECAST AREA...BUT STORMS MOVING INTO
THAT AREA ARE LIKELY TO BE SOMEWHAT ELEVATED...SO MAIN THREAT WOULD
BE LARGE HAIL AND POTENTIALLY DAMAGING WINDS. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP NEAR AND NORTHEAST OF THE
SURFACE LOW AS IT TRACKS INTO IOWA THIS EVENING. MORE SCATTERED
DEVELOPMENT IS EXPECTED ALONG AND AHEAD OF THE COLD FRONT AS IT
MOVES EAST. RUC MODEL SEEMS TO HAVE A GOOD HANDLE ON THIS EVOLUTION.
SEVERE THREAT IS LIKELY TO DIMINISH AFTER 9-10 PM. THERE IS SOME
POTENTIAL FOR THE SOUTHERN CONVECTION TO BLOSSOM NORTHWARD AS THE
COLD FRONT APPROACHES...SO THE HEAVIER PRECIPITATION AXIS IS LIKELY
TO BE FROM LAMONI TO EAST OF DES MOINES WITH 0.5-0.75 INCHES
POSSIBLE. TEMPERATURES WILL NOT FALL RAPIDLY OVERNIGHT DUE TO CLOUD
COVER AND WARM AND MOIST ADVECTION FOR A GOOD PORTION OF THE NIGHT.
.LONG TERM /FRIDAY THROUGH THURSDAY/...
FORECAST HAS CHANGED SOMEWHAT FROM PREVIOUS ISSUANCES WITH A BIT
MORE EMPHASIS ON PRECIP FRIDAY NIGHT AND SATURDAY NIGHT. CURRENT
SYSTEM WILL HAVE DEPARTED BY ONSET OF THE PERIOD WITH FAIR WEATHER
AND MORE MILD TEMPERATURES FRIDAY. HOWEVER SOME SEMBLANCE OF
CURRENT INSTABILITY GRADIENT AND BAROCLINIC ZONE JUST TO OUR SOUTH
IS EXPECTED TO RETURN NORTHWARD FRIDAY NIGHT AND COULD VERY WELL
ACTIVE MUCH LIKE IT HAS SINCE YESTERDAY. NAM/GFS/SREF ARE NOT
REALLY SUGGESTING MUCH IN THE WAY OF PRECIP TOMORROW NIGHT...HOWEVER
RECENT GEM REGIONAL AND GLOBAL MODELS AS WELL AS ECMWF RUNS HAVE
SUGGESTED ELEVATED CONVECTION WILL DEVELOP OVER EASTERN SECTIONS
OVERNIGHT. ECMWF HAS SHOWN NICE BAROCLINIC ZONE AND LIFT ALONG 300K
ISENT SURFACE. DO NOT EXPECT ANYTHING SIGNIFICANT BUT AM NO LONGER
COMFORTABLE GOING DRY SO SLIGHTS HAVE BEEN INTRODUCED. SIMILAR
SITUATION SATURDAY NIGHT ALTHOUGH DOMESTIC MODELS ARE NOW ON BOARD
TOO IN SIMILAR AREAS SO HAVE ADDED SLIGHT MENTIONS THERE AS WELL.
MODELS CONTINUE TO HAVE VARIED SOLUTIONS FOR SYSTEM EARLY NEXT WEEK
WITH DIFFERENT IDEAS ON STRENGTH OF SHORT WAVE IN BASE OF THE LONG
WAVE TROUGH AND OVERALL TIMING. GFS/GEM SOLUTIONS ARE SLOWER WITH
MORE EMPHASIS ON SRN PLAINS CLOSED LOW WHILE ECWMF HAS MORE NRN
STREAM ENERGY AND FASTER SOLUTION. THESE VARIED SOLUTIONS DO NOT
HAVE MUCH IMPACT ON SENSIBLE WEATHER HOWEVER WITH CHANCES INCREASE
EARLY MONDAY MORNING AND CONTINUE INTO MONDAY EVENING CENTRAL AND
EAST. REMAINDER OF THE FORECAST IS MILD AND DRY WITH UPPER LEVEL
RIDGING BUILDING BACK INTO THE MO VALLEY. NO FROST OR FREEZING
CONDITIONS APPEAR TO BE IN THE OFFING...AT LEAST THROUGH THE END OF
THE NEXT WORK WEEK.
&&
.AVIATION...30/00Z
MAIN CONCERNS IN THE IMMEDIATE 6-12 HOURS IS THUNDER. WARM FRONT
BECOMING ACTIVE AND APPROACHING COLD FRONT FROM NORTWEST WILL
INCREASE CHANCES FOR THUNDER BY 02-03Z WEST AND SOUTH...THEN
TRACKING EAST ACROSS ALL TAF SITES THROUGH 07Z. LOW RESPONSIBLE FOR
ACTIVITY WILL PULL EAST BY 12Z AND EXPECT SKIES TO CLEAR QUICKLY.
CHANCE FOR INCREASED WINDS/SMALL HAIL EXISTS FOR SOUTHERN TAF SITES
AFT 03Z...BUT MOST STORMS APPEAR TO BE ELEVATED WITH LESS SUPPORT
OVER THE REGION...SO VISBY AND BRIEFLY LOWER CIGS ALONG WITH SOME
WIND GUSTS APPEAR TO BE MAIN CONCERNS. WILL MONITOR THROUGH EVENING
AS EVENT UNFOLDS. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...JUNGBLUTH
AVIATION...REV
LONG TERM...SMALL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
349 PM CDT THU MAR 29 2012
.SHORT TERM /TONIGHT/...
MAIN FOCUS IS SHOWER AND THUNDERSTORM DEVELOPMENT AS SURFACE
LOW...CURRENTLY OVER NORTHERN KANSAS MOVES ACROSS SOUTHERN IOWA
TONIGHT. WHILE THIS IS HAPPENING...A COLD FRONT ACROSS THE EASTERN
DAKOTAS INTO NEBRASKA WILL ALSO MOVE ACROSS IOWA TONIGHT...SO THERE
COULD BE TWO ROUNDS OF PRECIPITATION FOCUS. WHAT WAS TO BE A WARM
FRONT HAS REMAINED STALLED ALONG THE MISSOURI RIVER IN
MISSOURI...WITH ONLY LIMITED PUSH NORTH INTO SE NEBRASKA...DUE TO
PERSISTENT CONVECTION IN NORTHERN MISSOURI. FRONT APPEARS UNLIKELY
TO MAKE INTO IOWA UNTIL MID OR LATE EVENING...SO THE OPPORTUNITY FOR
SURFACE BASED CONVECTION AND SIGNIFICANT SEVERE WEATHER POTENTIAL
APPEARS LIMITED. LOW-LEVEL SHEAR AND HELICITY WILL BE MODERATELY
STRONG OVER THE SOUTHWESTERN FORECAST AREA...BUT STORMS MOVING INTO
THAT AREA ARE LIKELY TO BE SOMEWHAT ELEVATED...SO MAIN THREAT WOULD
BE LARGE HAIL AND POTENTIALLY DAMAGING WINDS. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP NEAR AND NORTHEAST OF THE
SURFACE LOW AS IT TRACKS INTO IOWA THIS EVENING. MORE SCATTERED
DEVELOPMENT IS EXPECTED ALONG AND AHEAD OF THE COLD FRONT AS IT
MOVES EAST. RUC MODEL SEEMS TO HAVE A GOOD HANDLE ON THIS EVOLUTION.
SEVERE THREAT IS LIKELY TO DIMINISH AFTER 9-10 PM. THERE IS SOME
POTENTIAL FOR THE SOUTHERN CONVECTION TO BLOSSOM NORTHWARD AS THE
COLD FRONT APPROACHES...SO THE HEAVIER PRECIPITATION AXIS IS LIKELY
TO BE FROM LAMONI TO EAST OF DES MOINES WITH 0.5-0.75 INCHES
POSSIBLE. TEMPERATURES WILL NOT FALL RAPIDLY OVERNIGHT DUE TO CLOUD
COVER AND WARM AND MOIST ADVECTION FOR A GOOD PORTION OF THE NIGHT.
.LONG TERM /FRIDAY THROUGH THURSDAY/...
FORECAST HAS CHANGED SOMEWHAT FROM PREVIOUS ISSUANCES WITH A BIT
MORE EMPHASIS ON PRECIP FRIDAY NIGHT AND SATURDAY NIGHT. CURRENT
SYSTEM WILL HAVE DEPARTED BY ONSET OF THE PERIOD WITH FAIR WEATHER
AND MORE MILD TEMPERATURES FRIDAY. HOWEVER SOME SEMBLANCE OF
CURRENT INSTABILITY GRADIENT AND BAROCLINIC ZONE JUST TO OUR SOUTH
IS EXPECTED TO RETURN NORTHWARD FRIDAY NIGHT AND COULD VERY WELL
ACTIVE MUCH LIKE IT HAS SINCE YESTERDAY. NAM/GFS/SREF ARE NOT
REALLY SUGGESTING MUCH IN THE WAY OF PRECIP TOMORROW NIGHT...HOWEVER
RECENT GEM REGIONAL AND GLOBAL MODELS AS WELL AS ECMWF RUNS HAVE
SUGGESTED ELEVATED CONVECTION WILL DEVELOP OVER EASTERN SECTIONS
OVERNIGHT. ECMWF HAS SHOWN NICE BAROCLINIC ZONE AND LIFT ALONG 300K
ISENT SURFACE. DO NOT EXPECT ANYTHING SIGNIFICANT BUT AM NO LONGER
COMFORTABLE GOING DRY SO SLIGHTS HAVE BEEN INTRODUCED. SIMILAR
SITUATION SATURDAY NIGHT ALTHOUGH DOMESTIC MODELS ARE NOW ON BOARD
TOO IN SIMILAR AREAS SO HAVE ADDED SLIGHT MENTIONS THERE AS WELL.
MODELS CONTINUE TO HAVE VARIED SOLUTIONS FOR SYSTEM EARLY NEXT WEEK
WITH DIFFERENT IDEAS ON STRENGTH OF SHORT WAVE IN BASE OF THE LONG
WAVE TROUGH AND OVERALL TIMING. GFS/GEM SOLUTIONS ARE SLOWER WITH
MORE EMPHASIS ON SRN PLAINS CLOSED LOW WHILE ECWMF HAS MORE NRN
STREAM ENERGY AND FASTER SOLUTION. THESE VARIED SOLUTIONS DO NOT
HAVE MUCH IMPACT ON SENSIBLE WEATHER HOWEVER WITH CHANCES INCREASE
EARLY MONDAY MORNING AND CONTINUE INTO MONDAY EVENING CENTRAL AND
EAST. REMAINDER OF THE FORECAST IS MILD AND DRY WITH UPPER LEVEL
RIDGING BUILDING BACK INTO THE MO VALLEY. NO FROST OR FREEZING
CONDITIONS APPEAR TO BE IN THE OFFING...AT LEAST THROUGH THE END OF
THE NEXT WORK WEEK.
&&
.AVIATION...29/18Z
WARM FRONT IS NOT MAKING MUCH NORTHWARD PROGRESS DUE TO LOW CLOUDS
AND PERSISTENT THUNDERSTORMS OVER MO. TWO ROUND OF THUNDERSTORMS
POSSIBLE THIS EVENING AS LOW LEVEL MOISTURE LIFTS NORTH. FIRST ROUND
MAY HAVE EMBEDDED TSRA AS IT LIFTS NE ACROSS IA FROM 29/23Z-30/04Z.
SECOND ROUND WILL BE A NARROW BAND AS IT SWINGS EAST ACROSS NORTHERN
TAF SITES 30/04-07Z. IN BETWEEN...LIKELY TO BE LOW CLOUDS WITH MVFR
CIGS. COULD BE SOME IFR CEILINGS AND EVEN SOME FOG BEFORE WLY FLOW
AND DRIER AIR SWEEPS WEST TO EAST AFTER 30/09-12Z. ANY SEVERE
THUNDERSTORMS ARE LIKELY TO BE SW OF KDSM AND KOTM.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/AVIATION...JUNGBLUTH
LONG TERM...SMALL
AREA FORECAST DISCUSSION
NWS WICHITA KS
630 PM CDT FRI MAR 30 2012
.AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
ANTICIPATE EXCELLENT FLYING WEATHER FOR ALL AREAS THROUGHOUT THE 00Z
TAF CYCLE WITH S/SW WINDS OF 10KTS OR LESS ON SAT. WILL...HOWEVER BE
WATCHING FOR BR DEVELOPMENT ~10Z WITH LGT WIND...CLEAR SKIES & DAMP
GROUNDS FROM THE LOCALLY +RA OF THE PAST 2 NIGHTS.
&&
.PREV DISCUSSION... /ISSUED 302 PM CDT FRI MAR 30 2012/
DISCUSSION...
FORECAST CHALLENGES...ISOLATED STORM CHANCES/PATCHY FOG POTENTIAL
TONIGHT...THEN PRECIP CHANCES/COOLING TREND EARLY NEXT WEEK.
TONIGHT-SUNDAY
DRIER LOW LEVELS IN WAKE OF SURFACE TROF AND NOCTURNAL
CONVECTION/OUTFLOW THAT EXITED SOUTHERN KANSAS LAST NIGHT HAS
STABILIZED AIRMASS ACROSS THE AREA. HOWEVER THE RUC AND TO A
LESSER EXTENT THE HRRR SUGGEST ISOLATED CONVECTION MAY DEVELOP
ACROSS THE FLINT HILLS OR SOUTHEAST KANSAS BY EARLY THIS
EVENING...WHERE MODEST INSTABILITY WILL RESIDE IN PRESENCE OF
WEAKENING INHIBITION. SO WILL KEEP ISOLATED TSRA MENTION FOR
AREAS SOUTHEAST OF GREATER WICHITA. IF CONVECTION DEVELOPS IT MAY
PERSIST INTO A PORTION OF THE OVERNIGHT HOURS...AIDED BY A WEAK
UPPER SHORTWAVE MOVING ACROSS THE LOWER MISSOURI VALLEY. LOCAL
PROCEDURES OFF THE SHORT TERM MODELS ARE SUGGESTIVE OF PATCHY FOG
AROUND DAWN ACROSS PORTIONS OF SOUTH CENTRAL/SOUTHEAST KANSAS.
UNSEASONABLY WARM AND MAINLY DRY WEATHER STILL LOOKS IN ORDER
FOR THIS WEEKEND AS A LARGE AMPLITUDE UPPER RIDGE DEVELOPS ACROSS
THE PLAINS. ANOTHER MORE SUBTLE UPPER SHORTWAVE WILL RIPPLE THRU
THE DEVELOPING RIDGE TO OUR NORTH AND EAST ON SATURDAY AFTERNOON
AND EVENING. THIS WILL KEEP MID LEVEL TEMPERATURES RELATIVELY COOL
PORTENDING TO WEAK CAPPING ACROSS EASTERN KANSAS...WHERE MODEST
DIURNAL INSTABILITY WILL EXIST TOWARD PEAK HEATING. WHILE AN
ISOLATED STORM CANNOT BE RULED OUT...WILL KEEP THE FORECAST DRY
FOR NOW. SUNDAY LOOKS TO BE THE WARMEST DAY...DARE WE SUGGEST
ALMOST HOT...ACROSS THE FORECAST AREA. MAXS SHOULD APPROACH
RECORDS IN SOME AREAS NEAR 90F...WITH GUSTY SOUTH WINDS.
MONDAY
A SIGNIFICANT UPPER TROF WILL MOVE ACROSS THE ROCKIES ON SUNDAY
NIGHT AND INTO THE HIGH PLAINS ON MONDAY. WILL CONTINUE TO CARRY
MODEST CHANCE POPS AHEAD OF THIS FEATURE AND ASSOCIATED SURFACE
FRONT...THOUGH SOMEWHAT SLOWER TIMING SUGGESTED A SLIGHT UP-TWEAK
TO MAXS WERE NEEDED AND A BIT SLOWER ONSET TO POPS.
TUESDAY-FRIDAY
THE MEDIUM RANGE MODELS ARE STILL GRAPPLING WITH HANDLING THE
EVENTUAL UPPER FLOW STREAM SEPARATION AND MOVEMENT OF THE CLOSED
LOW WHICH BECOMES CUT-OFF FROM THE STRONGER WESTERLIES. THIS LOW
WILL IMPACT KANSAS WEATHER AND PRECIP CHANCES THROUGH THE EARLY
AND MID-WEEK PERIODS...AND FOR NOW HAVE CONTINUED TO LEAN TOWARD
THE HPC GUIDANCE AND MORE PROGRESSIVE GFS.
DARMOFAL
FIRE WEATHER...
DESPITE UNSEASONBALY WARM TEMPERATURES AND INCREASING WINDS OVER
THE WEEKEND...THE GRASSLAND FIRE DANGER RISK IS EXPECTED TO BE
ONLY SLIGHTLY ELEVATED DUE TO THE EARLY SPRING GREEN-UP.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 58 84 61 87 / 10 10 10 0
HUTCHINSON 56 85 61 88 / 10 10 10 0
NEWTON 58 84 61 87 / 10 10 10 0
ELDORADO 59 84 61 87 / 10 10 10 0
WINFIELD-KWLD 59 84 62 87 / 10 10 10 0
RUSSELL 55 87 59 89 / 10 10 10 0
GREAT BEND 55 86 59 88 / 10 10 10 0
SALINA 57 87 61 89 / 10 10 10 0
MCPHERSON 56 85 61 88 / 10 10 10 0
COFFEYVILLE 59 85 62 88 / 10 10 10 0
CHANUTE 59 84 62 87 / 10 10 10 10
IOLA 59 84 62 87 / 10 10 10 10
PARSONS-KPPF 59 84 62 87 / 10 10 10 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1236 PM CDT THU MAR 29 2012
...UPDATED AVIATION DISCUSSION...
.UPDATE...
ISSUED AT 930 AM CDT THU MAR 29 2012
HAVE CANCELLED THE DENSE FOG ADVISORY FOR TREGO/ELLIS COUNTIES AS
THE FOG HAS BEEN ERODING RAPIDLY OUT OF THAT AREA. MORNING TEMPERATURES
ARE ALSO A LITTLE WARMER IN AREAS OUT ALONG AND WEST OF HIGHWAY
83. HAVE MADE A FEW TWEAKS TO ACCOUNT FOR THIS AS WELL.
UPDATE ISSUED AT 634 AM CDT THU MAR 29 2012
SOUTHWEST WINDS WERE DEVELOPING ACROSS WESTERN KANSAS WITH LOWER
DEWPOINTS BEGINNING TO ADVECT INTO PORTIONS OF THE DENSE FOG
ADVISORY AREA. SATELLITE, SURFACE OBS AND PHONE CALLS AT OF 6 AM
INDICATED PATCH FOG AT BEST WERE OCCURRING SOUTH OF INTERSTATE 70.
AS A RESULT WILL TRIM SEVERAL COUNTIES OUT OF THE DENSE FOG
ADVISORY.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 217 AM CDT THU MAR 29 2012
.SYNOPSIS...
ISSUED AT 217 AM CDT THU MAR 29 2012
00Z 300 HPA SYNOPTIC MAP ANALYSIS SHOWS A 95 KT JET PUSHING ASHORE ACROSS
THE PACIFIC NORTHWEST IN ASSOCIATION WITH BROAD TROUGH EXTENDING FROM
THE PACNW TO THE NORTHERN ROCKIES. WEAKER 50 TO 75 KT BROAD W/NW FLOW
EXTENDED ACROSS THE NORTHERN PLAINS AND INTO THE GREAT LAKES REGION.
THE 500 HPA FLOW PATTERN SHOWED THE TROUGH AXIS IN ASSOCIATION WITH
THE AFOREMENTIONED JET STREAK FROM THE NORTHEAST PACIFIC AND SE ACROSS
THE GREAT BASIN. LOWER IN THE ATMOSPHERE...NAMELY THROUGH THE 700 AND
850 HPA LAYERS, THE MOST INTERESTING ITEM WAS WARM AND DRY FLOW IN
THE LEE OF THE ROCKIES. AT THE SFC, MSAS SURFACE PRESSURE ANALYSIS SHOWED
A WEAK LOW PRESSURE CENTER ACROSS SE COLORADO. A WARM FRONT WAS EXTENDING
FROM THIS FEATURE ACROSS CENTRAL KANSAS. RICH MOISTURE AS MARKED BY
DEWPOINTS IN THE 60S DEG F EXTENDED ACROSS SOUTH CENTRAL KANSAS.
THIS MORNING:
THE MAIN ITEM OF CONCERN DURING THE MORNING PERIOD IS THE LIKELIHOOD
FOR DENSE FOG. HRRR AND MOS IS SUGGESTING THE GREATEST POTENTIAL FOR
DENSE FOG ACROSS WEST CENTRAL KANSAS THIS MORNING. THIS IS ALSO REFLECTED
IN 00Z NAM BUFKIT DATA. THIS DENSE FOG IS IN ASSOCIATION WITH MODERATE
DEWPOINTS (LOW 50S DEG F) AND UPSLOPE E/SE FLOW ALONG AND AHEAD OF A
WARM FRONT THAT WILL MOVE ACROSS THE NORTHERN COUNTIES THROUGH MORNING.
TODAY:
THE FOG SHOULD DISSIPATE/MIX OUT BY MID MORNING. THE REST OF THE SENSIBLE
WEATHER FOR TODAY WILL BE FAIRLY TRANQUIL. A BROAD UPPER LEVEL SHORTWAVE
TROUGH WILL MOVE ACROSS THE NORTHERN PLAINS TODAY. SW KANSAS WILL BE
ON THE SOUTHEASTERN FRIDGES OF THE 400 HPA PV ANOMALY TODAY. AS A RESULT
OF THE AFOREMENTIONED UPPER LEVEL DYNAMICS SLIDING EAST THROUGH THE
DAY, THE RESULTANT SURFACE LOW WILL CONTINUE TO SLIDE TO THE EAST ACROSS
NORTHERN KANSAS AS WELL. A BIT OF DOWNSLOPE AND MIXING ACROSS THE SOUTHWESTERN
COUNTIES THIS AFTERNOON WILL PROVIDE VERY WARM TEMPERATURES NEAR THE
OKLAHOMA BORDER. EXPECT MID 80S DEG F IN THIS AREA. FURTHER NORTH, ONLY
LOOKING FOR UPPER 70S DEG F TO AROUND 80 DEG F AS A WEAK COLD FRONT
MOVES THROUGH EARLIER IN THE DAY. THE DRYLINE WITH UPPER 50S TO LOWER
60S DEG F DEWPOINTS WILL MIX EAST TODAY. THIS DRYLINE SHOULD BE LOCATED
ACROSS SOUTH CENTRAL KANSAS BY THIS AFTERNOON.
TONIGHT:
EVENTUALLY THE PACIFIC FRONT FOLLOWING BEHIND THE DRYLINE WILL CATCH
UP CLOSER TO THE DRYLINE. HAVE DISCOUNTED THE 00Z GFS SOLUTION AS THIS
MODEL SEEMS TO BE SUFFERING FROM BOUNDARY LAYER MOISTURE PROBLEMS AND
THE RESULTANT QPF LOOKS A LITTLE OVERZEALOUS. MAINLY STUCK WITH THE
00Z NAM AND 00Z WRF-NMM FOR POPS THIS EVENING. CONFINED POPS MAINLY ACROSS
SOUTH CENTRAL KANSAS AS TEMPERATURES IN THE 80S DEG F COMBINED WITH
NEAR 60 DEG F DEWPOINTS WILL CREATE ENOUGH SBCAPE IN THE 2000-2500 J/KG
RANGE SOUTH CENTRAL KANSAS. FORECAST SOUNDINGS SHOW CONSIDERABLE CINH
REMAINING ACROSS SC KS THROUGH MUCH OF THE DAY AND THEN FINALLY ERODING
BY TONIGHT. 0 TO 6 KM SHEAR OF AROUND 30 KT COULD SUPPORT THE NOTION
FOR MORE ORGANIZED CONVECTION ACROSS SE BARBER COUNTY. WILL HIGHLIGHT
THESE CONCERNS IN THE HWO. OTHER INFORMATION REGARDING CONVECTION CAN
BE FOUND IN THE SWODY1 PRODUCT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 328 AM CDT THU MAR 29 2012
A WEAK AREA OF HIGH PRESSURE WILL BUILD INTO WESTERN KANSAS EARLY
FRIDAY AS A COLD FRONT SINKS SOUTH INTO OKLAHOMA. THIS FRONT WILL
BECOME STATIONARY BY MID DAY AS AN UPPER LEVEL DISTURBANCE
EMBEDDED IN THE WEST NORTHWEST FLOW CROSSES INTO WESTERN KANSAS.
BOTH THE NAM AND GFS PLACES THE BETTER LATE DAY INSTABILITY
NEAR/JUST SOUTH OF THE OKLAHOMA BORDER WHICH IS ALSO WHERE THE
BETTER 850MB WARM AIR ADVECTION/ISENTROPIC LIFT IS FORECAST TO
IMPROVE AHEAD OF THIS UPPER WAVE. BASED ON THE LIFT,MOISTURE AND
INSTABILITY AT 00Z SATURDAY AHEAD OF AN UPPER LEVEL DISTURBANCE
WILL CONTINUE TO LEAN TOWARDS A DRY FORECAST FOR SOUTHWEST KANSAS.
DID HOWEVER KEEP THE 12 TO NEAR 15 PERCENT CHANCE OF PRECIPITATION
IN THE MEDICINE LODGE AND COLDWATER AREAS BASED ON HOW CLOSE THESE
LOCATIONS WILL BE TO THE MOISTURE/LIFT NORTH OF THE STATIONARY
FRONT EARLY FRIDAY NIGHT.
AS FOR TEMPERATURES...BASED ON 850MB TEMPERATURES AT 00Z SATURDAY
THE PREVIOUS FORECAST STILL LOOKS ON TRACK FOR HIGHS FRIDAY
AFTERNOON. DID HOWEVER LOWER TEMPERATURES IN SOUTHWEST KANSAS NEAR
THE OKLAHOMA BORDER BY A FEW DEGREES GIVEN THE BETTER CHANCES FOR
MORE CLOUD COVER IN THIS LOCATION FRIDAY AFTERNOON.
ONCE THIS SYSTEM MOVES EAST OF WESTERN KANSAS FRIDAY NIGHT A
WESTERLY DOWNSLOPE FLOW WILL THEN BEGIN TO DEVELOP. 24 HOUR 850MB
TEMPERATURE TRENDS OVER THE WEEKEND PERIOD SUPPORTS A NICE WARM
UP. 80S WILL BE LIKELY BOTH DAYS. A FEW LOCATIONS MAY EVEN
APPROACH 90 DEGREES ALONG AND SOUTH OF DODGE CITY IF THE 00Z
MONDAY 850MB TEMPERATURES FROM THE GFS AND ECMWF VERIFIES.
ON SUNDAY IT WILL ALSO BE WINDY AS A TIGHT SURFACE PRESSURE GRADIENT
DEVELOPS ACROSS WESTERN KANSAS IN RESPONSE TO AN AREA OF LOW
PRESSURE DEEPENING ALONG THE LEE OF THE ROCKIES. THIS DEEPENING
SURFACE LOW WILL THEN SLIDE EAST INTO WESTERN KANSAS SUNDAY NIGHT
AS AN UPPER LEVEL TROUGH EXITS THE ROCKIES AND MOVES OUT INTO THE
CENTRAL PLAINS. AN ELEVATED MIXED LAYER SHOULD INHIBIT
PRECIPITATION CHANCES ON SUNDAY AHEAD OF THIS NEXT SYSTEM. DRY AIR
MIXING DOWN TO THE SURFACE WILL INCREASE THE FIRE DANGER LEVELS
ACROSS WESTERN KANSAS...ESPECIALLY WEST OF THE DRY LINE.
A COLD FRONT WILL MOVE ACROSS WESTERN KANSAS EARLY MONDAY AS THIS
UPPER LEVEL TROUGH CROSSES INTO THE CENTRAL PLAINS. THE GFS
SUGGESTS SOME IMPROVING MID LEVEL INSTABILITY AS THE UPPER LEVEL
TROUGH CROSSES WESTERN KANSAS DURING THE DAY. BASED ON WHERE THE
BETTER MOISTURE RETURN WILL BE AHEAD OF THIS SYSTEM HAVE DECIDED
TO STAY CLOSE TO THE ALLBLEND ON PRECIPITATION CHANCES. THIS WOULD
PLACE A SLIGHT CHANCE FOR THUNDERSTORMS ACROSS PORTIONS OF NORTH
CENTRAL KANSAS. AS FOR TEMPERATURES HAVE DECIDED TO FOLLOW THE
GENERAL 925-850MB TEMPERATURE TRENDS FROM THE GFS AND ECMWF. THIS
WOULD FAVOR HIGHS MAINLY IN THE 60S ON MONDAY AS THIS UPPER LEVEL
TROUGH PASSES.
A WARMING TREND WILL RETURN BY MID WEEK AS AN UPPER LEVEL RIDGE
CROSSES THE ROCKIES AND A WESTERLY DOWNSLOPE FLOW IMPROVES ACROSS
EASTERN COLORADO AND WESTERN KANSAS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1236 PM CDT THU MAR 29 2012
MVFR CIGS WILL OCCUR AROUND HAYS FOR A FEW HOURS THIS AFTERNOON.
INCREASED MIXING AND WINDS SHOULD HELP SCATTER THE CIGS OUT BY
21Z. A WEAK COLD FRONT MOVING THROUGH SOUTHWEST KANSAS WILL BRING
GUSTY NORTH TO NORTHWEST WINDS TO THE TAF SITES BETWEEN 19Z AND
21Z. WIND GUSTS OF 25 TO 30 KNOTS WILL BE POSSIBLE. THUNDERSTORMS
ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON OR EARLY EVENING ALONG
THE FRONT. THE FRONT SHOULD BE WELL TO THE SOUTHEAST OF DODGE CITY
BY THEN BUT WILL CARRY A TAF PERIOD WITH CB`S FROM AROUND 21Z TO 02Z.
&&
.FIRE WEATHER...
ISSUED AT 328 AM CDT THU MAR 29 2012
GUSTY SOUTHWEST WINDS WILL DEVELOP ON SUNDAY AS AN AREA OF LOW
PRESSURE DEEPENS ACROSS NORTHEAST COLORADO. SUSTAINED WINDS OF 20 TO
30 MPH WILL BE LIKELY. IN ADDITION AFTERNOON RELATIVE HUMIDITIES
ARE EXPECTED TO FALL BACK INTO THE TEENS WEST OF A DRYLINE WHICH
CURRENTLY IS EXPECTED TO EXTEND FROM NEAR SCOTT CITY TO GARDEN
CITY TO NEAR LIBERAL. THIS COMBINATION WILL RESULT IN VERY HIGH TO
CRITICAL FIRE WEATHER CONDITIONS ACROSS PORTIONS OF WESTERN KANSAS
SUNDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 83 48 78 51 / 10 10 10 10
GCK 82 47 77 51 / 0 10 10 0
EHA 81 46 76 51 / 0 10 10 0
LBL 85 47 77 49 / 0 10 10 10
HYS 79 47 79 50 / 0 10 10 0
P28 84 53 80 56 / 10 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GERARD
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....BURGERT
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
930 AM CDT THU MAR 29 2012
...UPDATES TO MORNING FORECAST...
.UPDATE...
ISSUED AT 930 AM CDT THU MAR 29 2012
HAVE CANCELLED THE DENSE FOG ADVISORY FOR TREGO/ELLIS COUNTIES AS
THE FOG HAS BEEN ERODING RAPIDLY OUT OF THAT AREA. MORNING TEMPERATURES
ARE ALSO A LITTLE WARMER IN AREAS OUT ALONG AND WEST OF HIGHWAY
83. HAVE MADE A FEW TWEAKS TO ACCOUNT FOR THIS AS WELL.
UPDATE ISSUED AT 634 AM CDT THU MAR 29 2012
SOUTHWEST WINDS WERE DEVELOPING ACROSS WESTERN KANSAS WITH LOWER
DEWPOINTS BEGINNING TO ADVECT INTO PORTIONS OF THE DENSE FOG
ADVISORY AREA. SATELLITE, SURFACE OBS AND PHONE CALLS AT OF 6 AM
INDICATED PATCH FOG AT BEST WERE OCCURRING SOUTH OF INTERSTATE 70.
AS A RESULT WILL TRIM SEVERAL COUNTIES OUT OF THE DENSE FOG
ADVISORY.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 217 AM CDT THU MAR 29 2012
.SYNOPSIS...
ISSUED AT 217 AM CDT THU MAR 29 2012
00Z 300 HPA SYNOPTIC MAP ANALYSIS SHOWS A 95 KT JET PUSHING ASHORE ACROSS
THE PACIFIC NORTHWEST IN ASSOCIATION WITH BROAD TROUGH EXTENDING FROM
THE PACNW TO THE NORTHERN ROCKIES. WEAKER 50 TO 75 KT BROAD W/NW FLOW
EXTENDED ACROSS THE NORTHERN PLAINS AND INTO THE GREAT LAKES REGION.
THE 500 HPA FLOW PATTERN SHOWED THE TROUGH AXIS IN ASSOCIATION WITH
THE AFOREMENTIONED JET STREAK FROM THE NORTHEAST PACIFIC AND SE ACROSS
THE GREAT BASIN. LOWER IN THE ATMOSPHERE...NAMELY THROUGH THE 700 AND
850 HPA LAYERS, THE MOST INTERESTING ITEM WAS WARM AND DRY FLOW IN
THE LEE OF THE ROCKIES. AT THE SFC, MSAS SURFACE PRESSURE ANALYSIS SHOWED
A WEAK LOW PRESSURE CENTER ACROSS SE COLORADO. A WARM FRONT WAS EXTENDING
FROM THIS FEATURE ACROSS CENTRAL KANSAS. RICH MOISTURE AS MARKED BY
DEWPOINTS IN THE 60S DEG F EXTENDED ACROSS SOUTH CENTRAL KANSAS.
THIS MORNING:
THE MAIN ITEM OF CONCERN DURING THE MORNING PERIOD IS THE LIKELIHOOD
FOR DENSE FOG. HRRR AND MOS IS SUGGESTING THE GREATEST POTENTIAL FOR
DENSE FOG ACROSS WEST CENTRAL KANSAS THIS MORNING. THIS IS ALSO REFLECTED
IN 00Z NAM BUFKIT DATA. THIS DENSE FOG IS IN ASSOCIATION WITH MODERATE
DEWPOINTS (LOW 50S DEG F) AND UPSLOPE E/SE FLOW ALONG AND AHEAD OF A
WARM FRONT THAT WILL MOVE ACROSS THE NORTHERN COUNTIES THROUGH MORNING.
TODAY:
THE FOG SHOULD DISSIPATE/MIX OUT BY MID MORNING. THE REST OF THE SENSIBLE
WEATHER FOR TODAY WILL BE FAIRLY TRANQUIL. A BROAD UPPER LEVEL SHORTWAVE
TROUGH WILL MOVE ACROSS THE NORTHERN PLAINS TODAY. SW KANSAS WILL BE
ON THE SOUTHEASTERN FRIDGES OF THE 400 HPA PV ANOMALY TODAY. AS A RESULT
OF THE AFOREMENTIONED UPPER LEVEL DYNAMICS SLIDING EAST THROUGH THE
DAY, THE RESULTANT SURFACE LOW WILL CONTINUE TO SLIDE TO THE EAST ACROSS
NORTHERN KANSAS AS WELL. A BIT OF DOWNSLOPE AND MIXING ACROSS THE SOUTHWESTERN
COUNTIES THIS AFTERNOON WILL PROVIDE VERY WARM TEMPERATURES NEAR THE
OKLAHOMA BORDER. EXPECT MID 80S DEG F IN THIS AREA. FURTHER NORTH, ONLY
LOOKING FOR UPPER 70S DEG F TO AROUND 80 DEG F AS A WEAK COLD FRONT
MOVES THROUGH EARLIER IN THE DAY. THE DRYLINE WITH UPPER 50S TO LOWER
60S DEG F DEWPOINTS WILL MIX EAST TODAY. THIS DRYLINE SHOULD BE LOCATED
ACROSS SOUTH CENTRAL KANSAS BY THIS AFTERNOON.
TONIGHT:
EVENTUALLY THE PACIFIC FRONT FOLLOWING BEHIND THE DRYLINE WILL CATCH
UP CLOSER TO THE DRYLINE. HAVE DISCOUNTED THE 00Z GFS SOLUTION AS THIS
MODEL SEEMS TO BE SUFFERING FROM BOUNDARY LAYER MOISTURE PROBLEMS AND
THE RESULTANT QPF LOOKS A LITTLE OVERZEALOUS. MAINLY STUCK WITH THE
00Z NAM AND 00Z WRF-NMM FOR POPS THIS EVENING. CONFINED POPS MAINLY ACROSS
SOUTH CENTRAL KANSAS AS TEMPERATURES IN THE 80S DEG F COMBINED WITH
NEAR 60 DEG F DEWPOINTS WILL CREATE ENOUGH SBCAPE IN THE 2000-2500 J/KG
RANGE SOUTH CENTRAL KANSAS. FORECAST SOUNDINGS SHOW CONSIDERABLE CINH
REMAINING ACROSS SC KS THROUGH MUCH OF THE DAY AND THEN FINALLY ERODING
BY TONIGHT. 0 TO 6 KM SHEAR OF AROUND 30 KT COULD SUPPORT THE NOTION
FOR MORE ORGANIZED CONVECTION ACROSS SE BARBER COUNTY. WILL HIGHLIGHT
THESE CONCERNS IN THE HWO. OTHER INFORMATION REGARDING CONVECTION CAN
BE FOUND IN THE SWODY1 PRODUCT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 328 AM CDT THU MAR 29 2012
A WEAK AREA OF HIGH PRESSURE WILL BUILD INTO WESTERN KANSAS EARLY
FRIDAY AS A COLD FRONT SINKS SOUTH INTO OKLAHOMA. THIS FRONT WILL
BECOME STATIONARY BY MID DAY AS AN UPPER LEVEL DISTURBANCE
EMBEDDED IN THE WEST NORTHWEST FLOW CROSSES INTO WESTERN KANSAS.
BOTH THE NAM AND GFS PLACES THE BETTER LATE DAY INSTABILITY
NEAR/JUST SOUTH OF THE OKLAHOMA BORDER WHICH IS ALSO WHERE THE
BETTER 850MB WARM AIR ADVECTION/ISENTROPIC LIFT IS FORECAST TO
IMPROVE AHEAD OF THIS UPPER WAVE. BASED ON THE LIFT,MOISTURE AND
INSTABILITY AT 00Z SATURDAY AHEAD OF AN UPPER LEVEL DISTURBANCE
WILL CONTINUE TO LEAN TOWARDS A DRY FORECAST FOR SOUTHWEST KANSAS.
DID HOWEVER KEEP THE 12 TO NEAR 15 PERCENT CHANCE OF PRECIPITATION
IN THE MEDICINE LODGE AND COLDWATER AREAS BASED ON HOW CLOSE THESE
LOCATIONS WILL BE TO THE MOISTURE/LIFT NORTH OF THE STATIONARY
FRONT EARLY FRIDAY NIGHT.
AS FOR TEMPERATURES...BASED ON 850MB TEMPERATURES AT 00Z SATURDAY
THE PREVIOUS FORECAST STILL LOOKS ON TRACK FOR HIGHS FRIDAY
AFTERNOON. DID HOWEVER LOWER TEMPERATURES IN SOUTHWEST KANSAS NEAR
THE OKLAHOMA BORDER BY A FEW DEGREES GIVEN THE BETTER CHANCES FOR
MORE CLOUD COVER IN THIS LOCATION FRIDAY AFTERNOON.
ONCE THIS SYSTEM MOVES EAST OF WESTERN KANSAS FRIDAY NIGHT A
WESTERLY DOWNSLOPE FLOW WILL THEN BEGIN TO DEVELOP. 24 HOUR 850MB
TEMPERATURE TRENDS OVER THE WEEKEND PERIOD SUPPORTS A NICE WARM
UP. 80S WILL BE LIKELY BOTH DAYS. A FEW LOCATIONS MAY EVEN
APPROACH 90 DEGREES ALONG AND SOUTH OF DODGE CITY IF THE 00Z
MONDAY 850MB TEMPERATURES FROM THE GFS AND ECMWF VERIFIES.
ON SUNDAY IT WILL ALSO BE WINDY AS A TIGHT SURFACE PRESSURE GRADIENT
DEVELOPS ACROSS WESTERN KANSAS IN RESPONSE TO AN AREA OF LOW
PRESSURE DEEPENING ALONG THE LEE OF THE ROCKIES. THIS DEEPENING
SURFACE LOW WILL THEN SLIDE EAST INTO WESTERN KANSAS SUNDAY NIGHT
AS AN UPPER LEVEL TROUGH EXITS THE ROCKIES AND MOVES OUT INTO THE
CENTRAL PLAINS. AN ELEVATED MIXED LAYER SHOULD INHIBIT
PRECIPITATION CHANCES ON SUNDAY AHEAD OF THIS NEXT SYSTEM. DRY AIR
MIXING DOWN TO THE SURFACE WILL INCREASE THE FIRE DANGER LEVELS
ACROSS WESTERN KANSAS...ESPECIALLY WEST OF THE DRY LINE.
A COLD FRONT WILL MOVE ACROSS WESTERN KANSAS EARLY MONDAY AS THIS
UPPER LEVEL TROUGH CROSSES INTO THE CENTRAL PLAINS. THE GFS
SUGGESTS SOME IMPROVING MID LEVEL INSTABILITY AS THE UPPER LEVEL
TROUGH CROSSES WESTERN KANSAS DURING THE DAY. BASED ON WHERE THE
BETTER MOISTURE RETURN WILL BE AHEAD OF THIS SYSTEM HAVE DECIDED
TO STAY CLOSE TO THE ALLBLEND ON PRECIPITATION CHANCES. THIS WOULD
PLACE A SLIGHT CHANCE FOR THUNDERSTORMS ACROSS PORTIONS OF NORTH
CENTRAL KANSAS. AS FOR TEMPERATURES HAVE DECIDED TO FOLLOW THE
GENERAL 925-850MB TEMPERATURE TRENDS FROM THE GFS AND ECMWF. THIS
WOULD FAVOR HIGHS MAINLY IN THE 60S ON MONDAY AS THIS UPPER LEVEL
TROUGH PASSES.
A WARMING TREND WILL RETURN BY MID WEEK AS AN UPPER LEVEL RIDGE
CROSSES THE ROCKIES AND A WESTERLY DOWNSLOPE FLOW IMPROVES ACROSS
EASTERN COLORADO AND WESTERN KANSAS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 606 AM CDT THU MAR 29 2012
10Z SURFACE ANALYSIS CONTINUES TO SUPPORT THE 06Z NAM AND 08Z
HRRR IN PLACING THE BETTER OPPORTUNITY FOR LIFR FOG/STATUS ACROSS
NORTH CENTRAL KANSAS, NEAR HAYS, EARLY THIS MORNING WHERE A MOIST
UPSLOPE FLOW CONTINUES. AS A RESULT WILL KEEP LIFR CIGS/VSBYS GOING
FOR THE NEXT FEW HOURS. FURTHER SOUTH AT GCK AND DDC A GUSTY
SOUTHWEST WIND HAD ALREADY DEVELOPS WITH LOWER DEWPOINTS NOW BEING
ADVECTED INTO THIS REGION SO VFR CONDITIONS ARE EXPECTED. MET AND
HRRR WERE IN DECENT AGREEMENT WITH TIMING OF THE NORTHWEST WINDS
DEVELOPING DURING THE EARLY AFTERNOON AS A WEAK COLD FRONT CROSSES
WESTERN KANSAS SO WILL STAY CLOSE TO MET TIMING OF THE WIND SHIFT
LATER TODAY.
&&
.FIRE WEATHER...
ISSUED AT 328 AM CDT THU MAR 29 2012
GUSTY SOUTHWEST WINDS WILL DEVELOP ON SUNDAY AS AN AREA OF LOW
PRESSURE DEEPENS ACROSS NORTHEAST COLORADO. SUSTAINED WINDS OF 20 TO
30 MPH WILL BE LIKELY. IN ADDITION AFTERNOON RELATIVE HUMIDITIES
ARE EXPECTED TO FALL BACK INTO THE TEENS WEST OF A DRYLINE WHICH
CURRENTLY IS EXPECTED TO EXTEND FROM NEAR SCOTT CITY TO GARDEN
CITY TO NEAR LIBERAL. THIS COMBINATION WILL RESULT IN VERY HIGH TO
CRITICAL FIRE WEATHER CONDITIONS ACROSS PORTIONS OF WESTERN KANSAS
SUNDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 83 48 78 51 / 10 10 10 10
GCK 82 47 77 51 / 0 10 10 0
EHA 81 46 76 51 / 0 10 10 0
LBL 85 47 77 49 / 0 10 10 10
HYS 79 47 79 50 / 0 10 10 0
P28 84 53 80 56 / 10 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GERARD
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
643 AM CDT THU MAR 29 2012
...UPDATED TO CANCEL PARTS OF THE DENSE FOG ADVISORY...
.UPDATE...
ISSUED AT 634 AM CDT THU MAR 29 2012
SOUTHWEST WINDS WERE DEVELOPING ACROSS WESTERN KANSAS WITH LOWER
DEWPOINTS BEGINNING TO ADVECT INTO PORTIONS OF THE DENSE FOG
ADVISORY AREA. SATELLITE, SURFACE OBS AND PHONE CALLS AT OF 6 AM
INDICATED PATCH FOG AT BEST WERE OCCURRING SOUTH OF INTERSTATE 70.
AS A RESULT WILL TRIM SEVERAL COUNTIES OUT OF THE DENSE FOG
ADVISORY.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 217 AM CDT THU MAR 29 2012
.SYNOPSIS...
ISSUED AT 217 AM CDT THU MAR 29 2012
00Z 300 HPA SYNOPTIC MAP ANALYSIS SHOWS A 95 KT JET PUSHING ASHORE ACROSS
THE PACIFIC NORTHWEST IN ASSOCIATION WITH BROAD TROUGH EXTENDING FROM
THE PACNW TO THE NORTHERN ROCKIES. WEAKER 50 TO 75 KT BROAD W/NW FLOW
EXTENDED ACROSS THE NORTHERN PLAINS AND INTO THE GREAT LAKES REGION.
THE 500 HPA FLOW PATTERN SHOWED THE TROUGH AXIS IN ASSOCIATION WITH
THE AFOREMENTIONED JET STREAK FROM THE NORTHEAST PACIFIC AND SE ACROSS
THE GREAT BASIN. LOWER IN THE ATMOSPHERE...NAMELY THROUGH THE 700 AND
850 HPA LAYERS, THE MOST INTERESTING ITEM WAS WARM AND DRY FLOW IN
THE LEE OF THE ROCKIES. AT THE SFC, MSAS SURFACE PRESSURE ANALYSIS SHOWED
A WEAK LOW PRESSURE CENTER ACROSS SE COLORADO. A WARM FRONT WAS EXTENDING
FROM THIS FEATURE ACROSS CENTRAL KANSAS. RICH MOISTURE AS MARKED BY
DEWPOINTS IN THE 60S DEG F EXTENDED ACROSS SOUTH CENTRAL KANSAS.
THIS MORNING:
THE MAIN ITEM OF CONCERN DURING THE MORNING PERIOD IS THE LIKELIHOOD
FOR DENSE FOG. HRRR AND MOS IS SUGGESTING THE GREATEST POTENTIAL FOR
DENSE FOG ACROSS WEST CENTRAL KANSAS THIS MORNING. THIS IS ALSO REFLECTED
IN 00Z NAM BUFKIT DATA. THIS DENSE FOG IS IN ASSOCIATION WITH MODERATE
DEWPOINTS (LOW 50S DEG F) AND UPSLOPE E/SE FLOW ALONG AND AHEAD OF A
WARM FRONT THAT WILL MOVE ACROSS THE NORTHERN COUNTIES THROUGH MORNING.
TODAY:
THE FOG SHOULD DISSIPATE/MIX OUT BY MID MORNING. THE REST OF THE SENSIBLE
WEATHER FOR TODAY WILL BE FAIRLY TRANQUIL. A BROAD UPPER LEVEL SHORTWAVE
TROUGH WILL MOVE ACROSS THE NORTHERN PLAINS TODAY. SW KANSAS WILL BE
ON THE SOUTHEASTERN FRIDGES OF THE 400 HPA PV ANOMALY TODAY. AS A RESULT
OF THE AFOREMENTIONED UPPER LEVEL DYNAMICS SLIDING EAST THROUGH THE
DAY, THE RESULTANT SURFACE LOW WILL CONTINUE TO SLIDE TO THE EAST ACROSS
NORTHERN KANSAS AS WELL. A BIT OF DOWNSLOPE AND MIXING ACROSS THE SOUTHWESTERN
COUNTIES THIS AFTERNOON WILL PROVIDE VERY WARM TEMPERATURES NEAR THE
OKLAHOMA BORDER. EXPECT MID 80S DEG F IN THIS AREA. FURTHER NORTH, ONLY
LOOKING FOR UPPER 70S DEG F TO AROUND 80 DEG F AS A WEAK COLD FRONT
MOVES THROUGH EARLIER IN THE DAY. THE DRYLINE WITH UPPER 50S TO LOWER
60S DEG F DEWPOINTS WILL MIX EAST TODAY. THIS DRYLINE SHOULD BE LOCATED
ACROSS SOUTH CENTRAL KANSAS BY THIS AFTERNOON.
TONIGHT:
EVENTUALLY THE PACIFIC FRONT FOLLOWING BEHIND THE DRYLINE WILL CATCH
UP CLOSER TO THE DRYLINE. HAVE DISCOUNTED THE 00Z GFS SOLUTION AS THIS
MODEL SEEMS TO BE SUFFERING FROM BOUNDARY LAYER MOISTURE PROBLEMS AND
THE RESULTANT QPF LOOKS A LITTLE OVERZEALOUS. MAINLY STUCK WITH THE
00Z NAM AND 00Z WRF-NMM FOR POPS THIS EVENING. CONFINED POPS MAINLY ACROSS
SOUTH CENTRAL KANSAS AS TEMPERATURES IN THE 80S DEG F COMBINED WITH
NEAR 60 DEG F DEWPOINTS WILL CREATE ENOUGH SBCAPE IN THE 2000-2500 J/KG
RANGE SOUTH CENTRAL KANSAS. FORECAST SOUNDINGS SHOW CONSIDERABLE CINH
REMAINING ACROSS SC KS THROUGH MUCH OF THE DAY AND THEN FINALLY ERODING
BY TONIGHT. 0 TO 6 KM SHEAR OF AROUND 30 KT COULD SUPPORT THE NOTION
FOR MORE ORGANIZED CONVECTION ACROSS SE BARBER COUNTY. WILL HIGHLIGHT
THESE CONCERNS IN THE HWO. OTHER INFORMATION REGARDING CONVECTION CAN
BE FOUND IN THE SWODY1 PRODUCT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 328 AM CDT THU MAR 29 2012
A WEAK AREA OF HIGH PRESSURE WILL BUILD INTO WESTERN KANSAS EARLY
FRIDAY AS A COLD FRONT SINKS SOUTH INTO OKLAHOMA. THIS FRONT WILL
BECOME STATIONARY BY MID DAY AS AN UPPER LEVEL DISTURBANCE
EMBEDDED IN THE WEST NORTHWEST FLOW CROSSES INTO WESTERN KANSAS.
BOTH THE NAM AND GFS PLACES THE BETTER LATE DAY INSTABILITY
NEAR/JUST SOUTH OF THE OKLAHOMA BORDER WHICH IS ALSO WHERE THE
BETTER 850MB WARM AIR ADVECTION/ISENTROPIC LIFT IS FORECAST TO
IMPROVE AHEAD OF THIS UPPER WAVE. BASED ON THE LIFT,MOISTURE AND
INSTABILITY AT 00Z SATURDAY AHEAD OF AN UPPER LEVEL DISTURBANCE
WILL CONTINUE TO LEAN TOWARDS A DRY FORECAST FOR SOUTHWEST KANSAS.
DID HOWEVER KEEP THE 12 TO NEAR 15 PERCENT CHANCE OF PRECIPITATION
IN THE MEDICINE LODGE AND COLDWATER AREAS BASED ON HOW CLOSE THESE
LOCATIONS WILL BE TO THE MOISTURE/LIFT NORTH OF THE STATIONARY
FRONT EARLY FRIDAY NIGHT.
AS FOR TEMPERATURES...BASED ON 850MB TEMPERATURES AT 00Z SATURDAY
THE PREVIOUS FORECAST STILL LOOKS ON TRACK FOR HIGHS FRIDAY
AFTERNOON. DID HOWEVER LOWER TEMPERATURES IN SOUTHWEST KANSAS NEAR
THE OKLAHOMA BORDER BY A FEW DEGREES GIVEN THE BETTER CHANCES FOR
MORE CLOUD COVER IN THIS LOCATION FRIDAY AFTERNOON.
ONCE THIS SYSTEM MOVES EAST OF WESTERN KANSAS FRIDAY NIGHT A
WESTERLY DOWNSLOPE FLOW WILL THEN BEGIN TO DEVELOP. 24 HOUR 850MB
TEMPERATURE TRENDS OVER THE WEEKEND PERIOD SUPPORTS A NICE WARM
UP. 80S WILL BE LIKELY BOTH DAYS. A FEW LOCATIONS MAY EVEN
APPROACH 90 DEGREES ALONG AND SOUTH OF DODGE CITY IF THE 00Z
MONDAY 850MB TEMPERATURES FROM THE GFS AND ECMWF VERIFIES.
ON SUNDAY IT WILL ALSO BE WINDY AS A TIGHT SURFACE PRESSURE GRADIENT
DEVELOPS ACROSS WESTERN KANSAS IN RESPONSE TO AN AREA OF LOW
PRESSURE DEEPENING ALONG THE LEE OF THE ROCKIES. THIS DEEPENING
SURFACE LOW WILL THEN SLIDE EAST INTO WESTERN KANSAS SUNDAY NIGHT
AS AN UPPER LEVEL TROUGH EXITS THE ROCKIES AND MOVES OUT INTO THE
CENTRAL PLAINS. AN ELEVATED MIXED LAYER SHOULD INHIBIT
PRECIPITATION CHANCES ON SUNDAY AHEAD OF THIS NEXT SYSTEM. DRY AIR
MIXING DOWN TO THE SURFACE WILL INCREASE THE FIRE DANGER LEVELS
ACROSS WESTERN KANSAS...ESPECIALLY WEST OF THE DRY LINE.
A COLD FRONT WILL MOVE ACROSS WESTERN KANSAS EARLY MONDAY AS THIS
UPPER LEVEL TROUGH CROSSES INTO THE CENTRAL PLAINS. THE GFS
SUGGESTS SOME IMPROVING MID LEVEL INSTABILITY AS THE UPPER LEVEL
TROUGH CROSSES WESTERN KANSAS DURING THE DAY. BASED ON WHERE THE
BETTER MOISTURE RETURN WILL BE AHEAD OF THIS SYSTEM HAVE DECIDED
TO STAY CLOSE TO THE ALLBLEND ON PRECIPITATION CHANCES. THIS WOULD
PLACE A SLIGHT CHANCE FOR THUNDERSTORMS ACROSS PORTIONS OF NORTH
CENTRAL KANSAS. AS FOR TEMPERATURES HAVE DECIDED TO FOLLOW THE
GENERAL 925-850MB TEMPERATURE TRENDS FROM THE GFS AND ECMWF. THIS
WOULD FAVOR HIGHS MAINLY IN THE 60S ON MONDAY AS THIS UPPER LEVEL
TROUGH PASSES.
A WARMING TREND WILL RETURN BY MID WEEK AS AN UPPER LEVEL RIDGE
CROSSES THE ROCKIES AND A WESTERLY DOWNSLOPE FLOW IMPROVES ACROSS
EASTERN COLORADO AND WESTERN KANSAS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 606 AM CDT THU MAR 29 2012
10Z SURFACE ANALYSIS CONTINUES TO SUPPORT THE 06Z NAM AND 08Z
HRRR IN PLACING THE BETTER OPPORTUNITY FOR LIFR FOG/STATUS ACROSS
NORTH CENTRAL KANSAS, NEAR HAYS, EARLY THIS MORNING WHERE A MOIST
UPSLOPE FLOW CONTINUES. AS A RESULT WILL KEEP LIFR CIGS/VSBYS GOING
FOR THE NEXT FEW HOURS. FURTHER SOUTH AT GCK AND DDC A GUSTY
SOUTHWEST WIND HAD ALREADY DEVELOPS WITH LOWER DEWPOINTS NOW BEING
ADVECTED INTO THIS REGION SO VFR CONDITIONS ARE EXPECTED. MET AND
HRRR WERE IN DECENT AGREEMENT WITH TIMING OF THE NORTHWEST WINDS
DEVELOPING DURING THE EARLY AFTERNOON AS A WEAK COLD FRONT CROSSES
WESTERN KANSAS SO WILL STAY CLOSE TO MET TIMING OF THE WIND SHIFT
LATER TODAY.
&&
.FIRE WEATHER...
ISSUED AT 328 AM CDT THU MAR 29 2012
GUSTY SOUTHWEST WINDS WILL DEVELOP ON SUNDAY AS AN AREA OF LOW
PRESSURE DEEPENS ACROSS NORTHEAST COLORADO. SUSTAINED WINDS OF 20 TO
30 MPH WILL BE LIKELY. IN ADDITION AFTERNOON RELATIVE HUMIDITIES
ARE EXPECTED TO FALL BACK INTO THE TEENS WEST OF A DRYLINE WHICH
CURRENTLY IS EXPECTED TO EXTEND FROM NEAR SCOTT CITY TO GARDEN
CITY TO NEAR LIBERAL. THIS COMBINATION WILL RESULT IN VERY HIGH TO
CRITICAL FIRE WEATHER CONDITIONS ACROSS PORTIONS OF WESTERN KANSAS
SUNDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 83 48 78 51 / 10 10 10 10
GCK 82 47 77 51 / 0 10 10 10
EHA 81 46 76 51 / 0 10 10 10
LBL 85 47 77 49 / 0 10 10 10
HYS 79 47 79 50 / 0 10 10 10
P28 84 53 80 56 / 10 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR KSZ030-031-
043>046.
&&
$$
UPDATE...BURGERT
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
608 AM CDT THU MAR 29 2012
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 217 AM CDT THU MAR 29 2012
.SYNOPSIS...
ISSUED AT 217 AM CDT THU MAR 29 2012
00Z 300 HPA SYNOPTIC MAP ANALYSIS SHOWS A 95 KT JET PUSHING ASHORE ACROSS
THE PACIFIC NORTHWEST IN ASSOCIATION WITH BROAD TROUGH EXTENDING FROM
THE PACNW TO THE NORTHERN ROCKIES. WEAKER 50 TO 75 KT BROAD W/NW FLOW
EXTENDED ACROSS THE NORTHERN PLAINS AND INTO THE GREAT LAKES REGION.
THE 500 HPA FLOW PATTERN SHOWED THE TROUGH AXIS IN ASSOCIATION WITH
THE AFOREMENTIONED JET STREAK FROM THE NORTHEAST PACIFIC AND SE ACROSS
THE GREAT BASIN. LOWER IN THE ATMOSPHERE...NAMELY THROUGH THE 700 AND
850 HPA LAYERS, THE MOST INTERESTING ITEM WAS WARM AND DRY FLOW IN
THE LEE OF THE ROCKIES. AT THE SFC, MSAS SURFACE PRESSURE ANALYSIS SHOWED
A WEAK LOW PRESSURE CENTER ACROSS SE COLORADO. A WARM FRONT WAS EXTENDING
FROM THIS FEATURE ACROSS CENTRAL KANSAS. RICH MOISTURE AS MARKED BY
DEWPOINTS IN THE 60S DEG F EXTENDED ACROSS SOUTH CENTRAL KANSAS.
THIS MORNING:
THE MAIN ITEM OF CONCERN DURING THE MORNING PERIOD IS THE LIKELIHOOD
FOR DENSE FOG. HRRR AND MOS IS SUGGESTING THE GREATEST POTENTIAL FOR
DENSE FOG ACROSS WEST CENTRAL KANSAS THIS MORNING. THIS IS ALSO REFLECTED
IN 00Z NAM BUFKIT DATA. THIS DENSE FOG IS IN ASSOCIATION WITH MODERATE
DEWPOINTS (LOW 50S DEG F) AND UPSLOPE E/SE FLOW ALONG AND AHEAD OF A
WARM FRONT THAT WILL MOVE ACROSS THE NORTHERN COUNTIES THROUGH MORNING.
TODAY:
THE FOG SHOULD DISSIPATE/MIX OUT BY MID MORNING. THE REST OF THE SENSIBLE
WEATHER FOR TODAY WILL BE FAIRLY TRANQUIL. A BROAD UPPER LEVEL SHORTWAVE
TROUGH WILL MOVE ACROSS THE NORTHERN PLAINS TODAY. SW KANSAS WILL BE
ON THE SOUTHEASTERN FRIDGES OF THE 400 HPA PV ANOMALY TODAY. AS A RESULT
OF THE AFOREMENTIONED UPPER LEVEL DYNAMICS SLIDING EAST THROUGH THE
DAY, THE RESULTANT SURFACE LOW WILL CONTINUE TO SLIDE TO THE EAST ACROSS
NORTHERN KANSAS AS WELL. A BIT OF DOWNSLOPE AND MIXING ACROSS THE SOUTHWESTERN
COUNTIES THIS AFTERNOON WILL PROVIDE VERY WARM TEMPERATURES NEAR THE
OKLAHOMA BORDER. EXPECT MID 80S DEG F IN THIS AREA. FURTHER NORTH, ONLY
LOOKING FOR UPPER 70S DEG F TO AROUND 80 DEG F AS A WEAK COLD FRONT
MOVES THROUGH EARLIER IN THE DAY. THE DRYLINE WITH UPPER 50S TO LOWER
60S DEG F DEWPOINTS WILL MIX EAST TODAY. THIS DRYLINE SHOULD BE LOCATED
ACROSS SOUTH CENTRAL KANSAS BY THIS AFTERNOON.
TONIGHT:
EVENTUALLY THE PACIFIC FRONT FOLLOWING BEHIND THE DRYLINE WILL CATCH
UP CLOSER TO THE DRYLINE. HAVE DISCOUNTED THE 00Z GFS SOLUTION AS THIS
MODEL SEEMS TO BE SUFFERING FROM BOUNDARY LAYER MOISTURE PROBLEMS AND
THE RESULTANT QPF LOOKS A LITTLE OVERZEALOUS. MAINLY STUCK WITH THE
00Z NAM AND 00Z WRF-NMM FOR POPS THIS EVENING. CONFINED POPS MAINLY ACROSS
SOUTH CENTRAL KANSAS AS TEMPERATURES IN THE 80S DEG F COMBINED WITH
NEAR 60 DEG F DEWPOINTS WILL CREATE ENOUGH SBCAPE IN THE 2000-2500 J/KG
RANGE SOUTH CENTRAL KANSAS. FORECAST SOUNDINGS SHOW CONSIDERABLE CINH
REMAINING ACROSS SC KS THROUGH MUCH OF THE DAY AND THEN FINALLY ERODING
BY TONIGHT. 0 TO 6 KM SHEAR OF AROUND 30 KT COULD SUPPORT THE NOTION
FOR MORE ORGANIZED CONVECTION ACROSS SE BARBER COUNTY. WILL HIGHLIGHT
THESE CONCERNS IN THE HWO. OTHER INFORMATION REGARDING CONVECTION CAN
BE FOUND IN THE SWODY1 PRODUCT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 328 AM CDT THU MAR 29 2012
A WEAK AREA OF HIGH PRESSURE WILL BUILD INTO WESTERN KANSAS EARLY
FRIDAY AS A COLD FRONT SINKS SOUTH INTO OKLAHOMA. THIS FRONT WILL
BECOME STATIONARY BY MID DAY AS AN UPPER LEVEL DISTURBANCE
EMBEDDED IN THE WEST NORTHWEST FLOW CROSSES INTO WESTERN KANSAS.
BOTH THE NAM AND GFS PLACES THE BETTER LATE DAY INSTABILITY
NEAR/JUST SOUTH OF THE OKLAHOMA BORDER WHICH IS ALSO WHERE THE
BETTER 850MB WARM AIR ADVECTION/ISENTROPIC LIFT IS FORECAST TO
IMPROVE AHEAD OF THIS UPPER WAVE. BASED ON THE LIFT,MOISTURE AND
INSTABILITY AT 00Z SATURDAY AHEAD OF AN UPPER LEVEL DISTURBANCE
WILL CONTINUE TO LEAN TOWARDS A DRY FORECAST FOR SOUTHWEST KANSAS.
DID HOWEVER KEEP THE 12 TO NEAR 15 PERCENT CHANCE OF PRECIPITATION
IN THE MEDICINE LODGE AND COLDWATER AREAS BASED ON HOW CLOSE THESE
LOCATIONS WILL BE TO THE MOISTURE/LIFT NORTH OF THE STATIONARY
FRONT EARLY FRIDAY NIGHT.
AS FOR TEMPERATURES...BASED ON 850MB TEMPERATURES AT 00Z SATURDAY
THE PREVIOUS FORECAST STILL LOOKS ON TRACK FOR HIGHS FRIDAY
AFTERNOON. DID HOWEVER LOWER TEMPERATURES IN SOUTHWEST KANSAS NEAR
THE OKLAHOMA BORDER BY A FEW DEGREES GIVEN THE BETTER CHANCES FOR
MORE CLOUD COVER IN THIS LOCATION FRIDAY AFTERNOON.
ONCE THIS SYSTEM MOVES EAST OF WESTERN KANSAS FRIDAY NIGHT A
WESTERLY DOWNSLOPE FLOW WILL THEN BEGIN TO DEVELOP. 24 HOUR 850MB
TEMPERATURE TRENDS OVER THE WEEKEND PERIOD SUPPORTS A NICE WARM
UP. 80S WILL BE LIKELY BOTH DAYS. A FEW LOCATIONS MAY EVEN
APPROACH 90 DEGREES ALONG AND SOUTH OF DODGE CITY IF THE 00Z
MONDAY 850MB TEMPERATURES FROM THE GFS AND ECMWF VERIFIES.
ON SUNDAY IT WILL ALSO BE WINDY AS A TIGHT SURFACE PRESSURE GRADIENT
DEVELOPS ACROSS WESTERN KANSAS IN RESPONSE TO AN AREA OF LOW
PRESSURE DEEPENING ALONG THE LEE OF THE ROCKIES. THIS DEEPENING
SURFACE LOW WILL THEN SLIDE EAST INTO WESTERN KANSAS SUNDAY NIGHT
AS AN UPPER LEVEL TROUGH EXITS THE ROCKIES AND MOVES OUT INTO THE
CENTRAL PLAINS. AN ELEVATED MIXED LAYER SHOULD INHIBIT
PRECIPITATION CHANCES ON SUNDAY AHEAD OF THIS NEXT SYSTEM. DRY AIR
MIXING DOWN TO THE SURFACE WILL INCREASE THE FIRE DANGER LEVELS
ACROSS WESTERN KANSAS...ESPECIALLY WEST OF THE DRY LINE.
A COLD FRONT WILL MOVE ACROSS WESTERN KANSAS EARLY MONDAY AS THIS
UPPER LEVEL TROUGH CROSSES INTO THE CENTRAL PLAINS. THE GFS
SUGGESTS SOME IMPROVING MID LEVEL INSTABILITY AS THE UPPER LEVEL
TROUGH CROSSES WESTERN KANSAS DURING THE DAY. BASED ON WHERE THE
BETTER MOISTURE RETURN WILL BE AHEAD OF THIS SYSTEM HAVE DECIDED
TO STAY CLOSE TO THE ALLBLEND ON PRECIPITATION CHANCES. THIS WOULD
PLACE A SLIGHT CHANCE FOR THUNDERSTORMS ACROSS PORTIONS OF NORTH
CENTRAL KANSAS. AS FOR TEMPERATURES HAVE DECIDED TO FOLLOW THE
GENERAL 925-850MB TEMPERATURE TRENDS FROM THE GFS AND ECMWF. THIS
WOULD FAVOR HIGHS MAINLY IN THE 60S ON MONDAY AS THIS UPPER LEVEL
TROUGH PASSES.
A WARMING TREND WILL RETURN BY MID WEEK AS AN UPPER LEVEL RIDGE
CROSSES THE ROCKIES AND A WESTERLY DOWNSLOPE FLOW IMPROVES ACROSS
EASTERN COLORADO AND WESTERN KANSAS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 606 AM CDT THU MAR 29 2012
10Z SURFACE ANALYSIS CONTINUES TO SUPPORT THE 06Z NAM AND 08Z
HRRR IN PLACING THE BETTER OPPORTUNITY FOR LIFR FOG/STATUS ACROSS
NORTH CENTRAL KANSAS, NEAR HAYS, EARLY THIS MORNING WHERE A MOIST
UPSLOPE FLOW CONTINUES. AS A RESULT WILL KEEP LIFR CIGS/VSBYS GOING
FOR THE NEXT FEW HOURS. FURTHER SOUTH AT GCK AND DDC A GUSTY
SOUTHWEST WIND HAD ALREADY DEVELOPS WITH LOWER DEWPOINTS NOW BEING
ADVECTED INTO THIS REGION SO VFR CONDITIONS ARE EXPECTED. MET AND
HRRR WERE IN DECENT AGREEMENT WITH TIMING OF THE NORTHWEST WINDS
DEVELOPING DURING THE EARLY AFTERNOON AS A WEAK COLD FRONT CROSSES
WESTERN KANSAS SO WILL STAY CLOSE TO MET TIMING OF THE WIND SHIFT
LATER TODAY.
&&
.FIRE WEATHER...
ISSUED AT 328 AM CDT THU MAR 29 2012
GUSTY SOUTHWEST WINDS WILL DEVELOP ON SUNDAY AS AN AREA OF LOW
PRESSURE DEEPENS ACROSS NORTHEAST COLORADO. SUSTAINED WINDS OF 20 TO
30 MPH WILL BE LIKELY. IN ADDITION AFTERNOON RELATIVE HUMIDITIES
ARE EXPECTED TO FALL BACK INTO THE TEENS WEST OF A DRYLINE WHICH
CURRENTLY IS EXPECTED TO EXTEND FROM NEAR SCOTT CITY TO GARDEN
CITY TO NEAR LIBERAL. THIS COMBINATION WILL RESULT IN VERY HIGH TO
CRITICAL FIRE WEATHER CONDITIONS ACROSS PORTIONS OF WESTERN KANSAS
SUNDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 83 48 78 51 / 10 10 10 10
GCK 82 47 77 51 / 0 10 10 10
EHA 81 46 76 51 / 0 10 10 10
LBL 85 47 77 49 / 0 10 10 10
HYS 79 47 79 50 / 0 10 10 10
P28 84 53 80 56 / 10 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR KSZ030-031-
043>046.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
332 AM CDT THU MAR 29 2012
...UPDATE TO LONG TERM AND FIRE WEATHER SECTION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 217 AM CDT THU MAR 29 2012
.SYNOPSIS...
ISSUED AT 217 AM CDT THU MAR 29 2012
00Z 300 HPA SYNOPTIC MAP ANALYSIS SHOWS A 95 KT JET PUSHING ASHORE ACROSS
THE PACIFIC NORTHWEST IN ASSOCIATION WITH BROAD TROUGH EXTENDING FROM
THE PACNW TO THE NORTHERN ROCKIES. WEAKER 50 TO 75 KT BROAD W/NW FLOW
EXTENDED ACROSS THE NORTHERN PLAINS AND INTO THE GREAT LAKES REGION.
THE 500 HPA FLOW PATTERN SHOWED THE TROUGH AXIS IN ASSOCIATION WITH
THE AFOREMENTIONED JET STREAK FROM THE NORTHEAST PACIFIC AND SE ACROSS
THE GREAT BASIN. LOWER IN THE ATMOSPHERE...NAMELY THROUGH THE 700 AND
850 HPA LAYERS, THE MOST INTERESTING ITEM WAS WARM AND DRY FLOW IN
THE LEE OF THE ROCKIES. AT THE SFC, MSAS SURFACE PRESSURE ANALYSIS SHOWED
A WEAK LOW PRESSURE CENTER ACROSS SE COLORADO. A WARM FRONT WAS EXTENDING
FROM THIS FEATURE ACROSS CENTRAL KANSAS. RICH MOISTURE AS MARKED BY
DEWPOINTS IN THE 60S DEG F EXTENDED ACROSS SOUTH CENTRAL KANSAS.
THIS MORNING:
THE MAIN ITEM OF CONCERN DURING THE MORNING PERIOD IS THE LIKELIHOOD
FOR DENSE FOG. HRRR AND MOS IS SUGGESTING THE GREATEST POTENTIAL FOR
DENSE FOG ACROSS WEST CENTRAL KANSAS THIS MORNING. THIS IS ALSO REFLECTED
IN 00Z NAM BUFKIT DATA. THIS DENSE FOG IS IN ASSOCIATION WITH MODERATE
DEWPOINTS (LOW 50S DEG F) AND UPSLOPE E/SE FLOW ALONG AND AHEAD OF A
WARM FRONT THAT WILL MOVE ACROSS THE NORTHERN COUNTIES THROUGH MORNING.
TODAY:
THE FOG SHOULD DISSIPATE/MIX OUT BY MID MORNING. THE REST OF THE SENSIBLE
WEATHER FOR TODAY WILL BE FAIRLY TRANQUIL. A BROAD UPPER LEVEL SHORTWAVE
TROUGH WILL MOVE ACROSS THE NORTHERN PLAINS TODAY. SW KANSAS WILL BE
ON THE SOUTHEASTERN FRIDGES OF THE 400 HPA PV ANOMALY TODAY. AS A RESULT
OF THE AFOREMENTIONED UPPER LEVEL DYNAMICS SLIDING EAST THROUGH THE
DAY, THE RESULTANT SURFACE LOW WILL CONTINUE TO SLIDE TO THE EAST ACROSS
NORTHERN KANSAS AS WELL. A BIT OF DOWNSLOPE AND MIXING ACROSS THE SOUTHWESTERN
COUNTIES THIS AFTERNOON WILL PROVIDE VERY WARM TEMPERATURES NEAR THE
OKLAHOMA BORDER. EXPECT MID 80S DEG F IN THIS AREA. FURTHER NORTH, ONLY
LOOKING FOR UPPER 70S DEG F TO AROUND 80 DEG F AS A WEAK COLD FRONT
MOVES THROUGH EARLIER IN THE DAY. THE DRYLINE WITH UPPER 50S TO LOWER
60S DEG F DEWPOINTS WILL MIX EAST TODAY. THIS DRYLINE SHOULD BE LOCATED
ACROSS SOUTH CENTRAL KANSAS BY THIS AFTERNOON.
TONIGHT:
EVENTUALLY THE PACIFIC FRONT FOLLOWING BEHIND THE DRYLINE WILL CATCH
UP CLOSER TO THE DRYLINE. HAVE DISCOUNTED THE 00Z GFS SOLUTION AS THIS
MODEL SEEMS TO BE SUFFERING FROM BOUNDARY LAYER MOISTURE PROBLEMS AND
THE RESULTANT QPF LOOKS A LITTLE OVERZEALOUS. MAINLY STUCK WITH THE
00Z NAM AND 00Z WRF-NMM FOR POPS THIS EVENING. CONFINED POPS MAINLY ACROSS
SOUTH CENTRAL KANSAS AS TEMPERATURES IN THE 80S DEG F COMBINED WITH
NEAR 60 DEG F DEWPOINTS WILL CREATE ENOUGH SBCAPE IN THE 2000-2500 J/KG
RANGE SOUTH CENTRAL KANSAS. FORECAST SOUNDINGS SHOW CONSIDERABLE CINH
REMAINING ACROSS SC KS THROUGH MUCH OF THE DAY AND THEN FINALLY ERODING
BY TONIGHT. 0 TO 6 KM SHEAR OF AROUND 30 KT COULD SUPPORT THE NOTION
FOR MORE ORGANIZED CONVECTION ACROSS SE BARBER COUNTY. WILL HIGHLIGHT
THESE CONCERNS IN THE HWO. OTHER INFORMATION REGARDING CONVECTION CAN
BE FOUND IN THE SWODY1 PRODUCT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 328 AM CDT THU MAR 29 2012
A WEAK AREA OF HIGH PRESSURE WILL BUILD INTO WESTERN KANSAS EARLY
FRIDAY AS A COLD FRONT SINKS SOUTH INTO OKLAHOMA. THIS FRONT WILL
BECOME STATIONARY BY MID DAY AS AN UPPER LEVEL DISTURBANCE
EMBEDDED IN THE WEST NORTHWEST FLOW CROSSES INTO WESTERN KANSAS.
BOTH THE NAM AND GFS PLACES THE BETTER LATE DAY INSTABILITY
NEAR/JUST SOUTH OF THE OKLAHOMA BORDER WHICH IS ALSO WHERE THE
BETTER 850MB WARM AIR ADVECTION/ISENTROPIC LIFT IS FORECAST TO
IMPROVE AHEAD OF THIS UPPER WAVE. BASED ON THE LIFT,MOISTURE AND
INSTABILITY AT 00Z SATURDAY AHEAD OF AN UPPER LEVEL DISTURBANCE
WILL CONTINUE TO LEAN TOWARDS A DRY FORECAST FOR SOUTHWEST KANSAS.
DID HOWEVER KEEP THE 12 TO NEAR 15 PERCENT CHANCE OF PRECIPITATION
IN THE MEDICINE LODGE AND COLDWATER AREAS BASED ON HOW CLOSE THESE
LOCATIONS WILL BE TO THE MOISTURE/LIFT NORTH OF THE STATIONARY
FRONT EARLY FRIDAY NIGHT.
AS FOR TEMPERATURES...BASED ON 850MB TEMPERATURES AT 00Z SATURDAY
THE PREVIOUS FORECAST STILL LOOKS ON TRACK FOR HIGHS FRIDAY
AFTERNOON. DID HOWEVER LOWER TEMPERATURES IN SOUTHWEST KANSAS NEAR
THE OKLAHOMA BORDER BY A FEW DEGREES GIVEN THE BETTER CHANCES FOR
MORE CLOUD COVER IN THIS LOCATION FRIDAY AFTERNOON.
ONCE THIS SYSTEM MOVES EAST OF WESTERN KANSAS FRIDAY NIGHT A
WESTERLY DOWNSLOPE FLOW WILL THEN BEGIN TO DEVELOP. 24 HOUR 850MB
TEMPERATURE TRENDS OVER THE WEEKEND PERIOD SUPPORTS A NICE WARM
UP. 80S WILL BE LIKELY BOTH DAYS. A FEW LOCATIONS MAY EVEN
APPROACH 90 DEGREES ALONG AND SOUTH OF DODGE CITY IF THE 00Z
MONDAY 850MB TEMPERATURES FROM THE GFS AND ECMWF VERIFIES.
ON SUNDAY IT WILL ALSO BE WINDY AS A TIGHT SURFACE PRESSURE GRADIENT
DEVELOPS ACROSS WESTERN KANSAS IN RESPONSE TO AN AREA OF LOW
PRESSURE DEEPENING ALONG THE LEE OF THE ROCKIES. THIS DEEPENING
SURFACE LOW WILL THEN SLIDE EAST INTO WESTERN KANSAS SUNDAY NIGHT
AS AN UPPER LEVEL TROUGH EXITS THE ROCKIES AND MOVES OUT INTO THE
CENTRAL PLAINS. AN ELEVATED MIXED LAYER SHOULD INHIBIT
PRECIPITATION CHANCES ON SUNDAY AHEAD OF THIS NEXT SYSTEM. DRY AIR
MIXING DOWN TO THE SURFACE WILL INCREASE THE FIRE DANGER LEVELS
ACROSS WESTERN KANSAS...ESPECIALLY WEST OF THE DRY LINE.
A COLD FRONT WILL MOVE ACROSS WESTERN KANSAS EARLY MONDAY AS THIS
UPPER LEVEL TROUGH CROSSES INTO THE CENTRAL PLAINS. THE GFS
SUGGESTS SOME IMPROVING MID LEVEL INSTABILITY AS THE UPPER LEVEL
TROUGH CROSSES WESTERN KANSAS DURING THE DAY. BASED ON WHERE THE
BETTER MOISTURE RETURN WILL BE AHEAD OF THIS SYSTEM HAVE DECIDED
TO STAY CLOSE TO THE ALLBLEND ON PRECIPITATION CHANCES. THIS WOULD
PLACE A SLIGHT CHANCE FOR THUNDERSTORMS ACROSS PORTIONS OF NORTH
CENTRAL KANSAS. AS FOR TEMPERATURES HAVE DECIDED TO FOLLOW THE
GENERAL 925-850MB TEMPERATURE TRENDS FROM THE GFS AND ECMWF. THIS
WOULD FAVOR HIGHS MAINLY IN THE 60S ON MONDAY AS THIS UPPER LEVEL
TROUGH PASSES.
A WARMING TREND WILL RETURN BY MID WEEK AS AN UPPER LEVEL RIDGE
CROSSES THE ROCKIES AND A WESTERLY DOWNSLOPE FLOW IMPROVES ACROSS
EASTERN COLORADO AND WESTERN KANSAS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1230 AM CDT THU MAR 29 2012
MAIN CONCERN FOR THE 06Z TAFS WAS TO REDUCE CIGS, PARTICULARLY AT
KHYS IN ASSOCIATION WITH REDUCED VISIBILITIES FROM DENSE FOG. BUFKIT,
MOS, AND HRRR LOW LEVEL RH`S FIELDS SUGGEST FOG DEVELOPING THIS MORNING
AND BECOMING DENSE A FEW HOURS CENTERED AROUND SUNRISE. LIFR CIGS EXPECTED
FOR KHYS. HAVE LOWER CONFIDENCE FOR KDDC AND KGCK AND KEPT CIGS IN MVFR
CONDITIONS. DRY AIR ADVECTION WILL SPREAD ACROSS THE REGION BEHIND AND
IN ASSOCIATION WITH A TRAVERSING SFC LOW BY LATE MORNING. CIGS SHOULD
IMPROVE TO VFR BY THAT TIME.
&&
.FIRE WEATHER...
ISSUED AT 328 AM CDT THU MAR 29 2012
GUSTY SOUTHWEST WINDS WILL DEVELOP ON SUNDAY AS AN AREA OF LOW
PRESSURE DEEPENS ACROSS NORTHEAST COLORADO. SUSTAINED WINDS OF 20 TO
30 MPH WILL BE LIKELY. IN ADDITION AFTERNOON RELATIVE HUMIDITIES
ARE EXPECTED TO FALL BACK INTO THE TEENS WEST OF A DRYLINE WHICH
CURRENTLY IS EXPECTED TO EXTEND FROM NEAR SCOTT CITY TO GARDEN
CITY TO NEAR LIBERAL. THIS COMBINATION WILL RESULT IN VERY HIGH TO
CRITICAL FIRE WEATHER CONDITIONS ACROSS PORTIONS OF WESTERN KANSAS
SUNDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 83 48 78 51 / 10 10 10 10
GCK 82 47 77 51 / 0 10 10 10
EHA 81 46 76 51 / 0 10 10 10
LBL 85 47 77 49 / 0 10 10 10
HYS 79 47 79 50 / 0 10 10 10
P28 84 53 80 56 / 10 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR KSZ030-031-
043>046.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....BURGERT
AVIATION...SUGDEN
FIRE WEATHER...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
220 AM CDT THU MAR 29 2012
...UPDATE TO SYNOPSIS AND SHORT TERM DISCUSSIONS...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 217 AM CDT THU MAR 29 2012
.SYNOPSIS...
ISSUED AT 217 AM CDT THU MAR 29 2012
00Z 300 HPA SYNOPTIC MAP ANALYSIS SHOWS A 95 KT JET PUSHING ASHORE ACROSS
THE PACIFIC NORTHWEST IN ASSOCIATION WITH BROAD TROUGH EXTENDING FROM
THE PACNW TO THE NORTHERN ROCKIES. WEAKER 50 TO 75 KT BROAD W/NW FLOW
EXTENDED ACROSS THE NORTHERN PLAINS AND INTO THE GREAT LAKES REGION.
THE 500 HPA FLOW PATTERN SHOWED THE TROUGH AXIS IN ASSOCIATION WITH
THE AFOREMENTIONED JET STREAK FROM THE NORTHEAST PACIFIC AND SE ACROSS
THE GREAT BASIN. LOWER IN THE ATMOSPHERE...NAMELY THROUGH THE 700 AND
850 HPA LAYERS, THE MOST INTERESTING ITEM WAS WARM AND DRY FLOW IN
THE LEE OF THE ROCKIES. AT THE SFC, MSAS SURFACE PRESSURE ANALYSIS SHOWED
A WEAK LOW PRESSURE CENTER ACROSS SE COLORADO. A WARM FRONT WAS EXTENDING
FROM THIS FEATURE ACROSS CENTRAL KANSAS. RICH MOISTURE AS MARKED BY
DEWPOINTS IN THE 60S DEG F EXTENDED ACROSS SOUTH CENTRAL KANSAS.
THIS MORNING:
THE MAIN ITEM OF CONCERN DURING THE MORNING PERIOD IS THE LIKELIHOOD
FOR DENSE FOG. HRRR AND MOS IS SUGGESTING THE GREATEST POTENTIAL FOR
DENSE FOG ACROSS WEST CENTRAL KANSAS THIS MORNING. THIS IS ALSO REFLECTED
IN 00Z NAM BUFKIT DATA. THIS DENSE FOG IS IN ASSOCIATION WITH MODERATE
DEWPOINTS (LOW 50S DEG F) AND UPSLOPE E/SE FLOW ALONG AND AHEAD OF A
WARM FRONT THAT WILL MOVE ACROSS THE NORTHERN COUNTIES THROUGH MORNING.
TODAY:
THE FOG SHOULD DISSIPATE/MIX OUT BY MID MORNING. THE REST OF THE SENSIBLE
WEATHER FOR TODAY WILL BE FAIRLY TRANQUIL. A BROAD UPPER LEVEL SHORTWAVE
TROUGH WILL MOVE ACROSS THE NORTHERN PLAINS TODAY. SW KANSAS WILL BE
ON THE SOUTHEASTERN FRIDGES OF THE 400 HPA PV ANOMALY TODAY. AS A RESULT
OF THE AFOREMENTIONED UPPER LEVEL DYNAMICS SLIDING EAST THROUGH THE
DAY, THE RESULTANT SURFACE LOW WILL CONTINUE TO SLIDE TO THE EAST ACROSS
NORTHERN KANSAS AS WELL. A BIT OF DOWNSLOPE AND MIXING ACROSS THE SOUTHWESTERN
COUNTIES THIS AFTERNOON WILL PROVIDE VERY WARM TEMPERATURES NEAR THE
OKLAHOMA BORDER. EXPECT MID 80S DEG F IN THIS AREA. FURTHER NORTH, ONLY
LOOKING FOR UPPER 70S DEG F TO AROUND 80 DEG F AS A WEAK COLD FRONT
MOVES THROUGH EARLIER IN THE DAY. THE DRYLINE WITH UPPER 50S TO LOWER
60S DEG F DEWPOINTS WILL MIX EAST TODAY. THIS DRYLINE SHOULD BE LOCATED
ACROSS SOUTH CENTRAL KANSAS BY THIS AFTERNOON.
TONIGHT:
EVENTUALLY THE PACIFIC FRONT FOLLOWING BEHIND THE DRYLINE WILL CATCH
UP CLOSER TO THE DRYLINE. HAVE DISCOUNTED THE 00Z GFS SOLUTION AS THIS
MODEL SEEMS TO BE SUFFERING FROM BOUNDARY LAYER MOISTURE PROBLEMS AND
THE RESULTANT QPF LOOKS A LITTLE OVERZEALOUS. MAINLY STUCK WITH THE
00Z NAM AND 00Z WRF-NMM FOR POPS THIS EVENING. CONFINED POPS MAINLY ACROSS
SOUTH CENTRAL KANSAS AS TEMPERATURES IN THE 80S DEG F COMBINED WITH
NEAR 60 DEG F DEWPOINTS WILL CREATE ENOUGH SBCAPE IN THE 2000-2500 J/KG
RANGE SOUTH CENTRAL KANSAS. FORECAST SOUNDINGS SHOW CONSIDERABLE CINH
REMAINING ACROSS SC KS THROUGH MUCH OF THE DAY AND THEN FINALLY ERODING
BY TONIGHT. 0 TO 6 KM SHEAR OF AROUND 30 KT COULD SUPPORT THE NOTION
FOR MORE ORGANIZED CONVECTION ACROSS SE BARBER COUNTY. WILL HIGHLIGHT
THESE CONCERNS IN THE HWO. OTHER INFORMATION REGARDING CONVECTION CAN
BE FOUND IN THE SWODY1 PRODUCT.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 349 PM CDT WED MAR 28 2012
MEDIUM RANGE MODELS INDICATE A SMALL AMPLITUDE UPPER LEVEL SHORTWAVE
TROUGH TRANSITIONING EAST ACROSS THE NORTHERN AND CENTRAL PLAINS
THURSDAY NIGHT BRINGING THE POSSIBILITY FOR SHOWERS AND THUNDERSTORMS
TO CENTRAL AND PORTIONS OF WESTERN KANSAS THURSDAY EVENING. AN
ATTENDANT COLD FRONT IS PROJECTED TO PUSH INTO WESTERN KANSAS
EARLIER THURSDAY WITH AMPLE LOW LEVEL MOISTURE POOLING AHEAD OF
THE BOUNDARY WITH H85 DEWPOINTS UP NEAR 10C. NAM AND GFS MODEL
SOUNDINGS SHOW PLENTY OF INSTABILITY AHEAD OF A DEVELOPING DRYLINE
WITH CAPE VALUES IN EXCESS OF 1500J/KG. HOWEVER, ONE ISSUE OF
CONCERN HAS ALL MODELS POINTING TO A FAIRLY WEAK WESTERLY FLOW ALOFT
ACROSS THE CENTRAL PLAINS WHICH MAY LIMIT THE STRENGTH CAPABILITY OF
ANY STORM DEVELOPMENT. STILL, WITH SOME UNCERTAINTY REMAINING AS TO
THE TIMING AND POSITIONING OF THE FRONTAL BOUNDARY, THE BEST CHANCE
FOR SHOWERS AND THUNDERSTORMS LOOKS TO BE ACROSS SOUTH CENTRAL
KANSAS THURSDAY EVENING. UPPER LEVEL RIDGING IS THEN EXPECTED TO
BUILD AS IT MOVES EAST ACROSS THE INTERMOUNTAIN WEST INTO THE
CENTRAL PLAINS THROUGH THE WEEKEND BRINGING ABOUT DRIER CONDITIONS
TO WESTERN KANSAS THROUGH AT LEAST EARLY SUNDAY. THE GFS AND ECMWF
INDICATE AN UPPER LEVEL TROUGH PUSHING ACROSS THE INTERMOUNTAIN
WEST LATE IN THE WEEKEND BRINGING THE NEXT REASONABLE CHANCE FOR
PRECIP TO WESTERN KANSAS EARLY NEXT WEEK.
TEMPERATURES ARE EXPECTED TO BE JUST ABOVE NORMAL FRIDAY EVEN IN
WAKE OF A COLD FRONTAL PASSAGE LATE THURSDAY. THE NAM, GFS, AND
ECMWF SHOW ONLY MARGINALLY COOLER AIR FILTERING INTO WESTERN KANSAS
WITH H85 TEMPERATURES MAINLY IN THE MID TO UPPER TEENS(C). LOOK FOR
HIGHS UP INTO THE 70S(F) FRIDAY AFTERNOON. A GRADUAL WARMING TREND
IS LIKELY THROUGH THE WEEKEND AS UPPER LEVEL RIDGING MOVES IN FROM
THE INTERMOUNTAIN WEST. EXPECT HIGHS UP INTO THE 80S(F) SATURDAY AND
SUNDAY AS A STRENGTHENING LEE SIDE TROUGH OF LOW PRESSURE ENHANCES
WARM AIR ADVECTION INTO WESTERN KANSAS WITHIN A STRONG SOUTHERLY LOW
LEVEL FLOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1230 AM CDT THU MAR 29 2012
MAIN CONCERN FOR THE 06Z TAFS WAS TO REDUCE CIGS, PARTICULARLY AT
KHYS IN ASSOCIATION WITH REDUCED VISIBILITIES FROM DENSE FOG. BUFKIT,
MOS, AND HRRR LOW LEVEL RH`S FIELDS SUGGEST FOG DEVELOPING THIS MORNING
AND BECOMING DENSE A FEW HOURS CENTERED AROUND SUNRISE. LIFR CIGS EXPECTED
FOR KHYS. HAVE LOWER CONFIDENCE FOR KDDC AND KGCK AND KEPT CIGS IN MVFR
CONDITIONS. DRY AIR ADVECTION WILL SPREAD ACROSS THE REGION BEHIND AND
IN ASSOCIATION WITH A TRAVERSING SFC LOW BY LATE MORNING. CIGS SHOULD
IMPROVE TO VFR BY THAT TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 83 48 78 51 / 10 10 10 10
GCK 82 47 77 51 / 0 10 10 10
EHA 81 46 76 51 / 0 10 10 10
LBL 85 47 77 49 / 0 10 10 10
HYS 79 47 79 50 / 0 10 10 10
P28 84 53 80 56 / 10 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY FROM 5 AM TO 10 AM CDT THIS MORNING FOR
KSZ030-031-043>046.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....JJOHNSON
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1230 AM CDT THU MAR 29 2012
...UPDATE FOR FOG AND 06Z TAF AVIATION DISCUSSION...
.UPDATE...
ISSUED AT 1230 AM CDT THU MAR 29 2012
HAVE TWEAKED/CHANGED THE WX GRIDS WITHIN THE LAST HOUR TO ADD DENSE
FOG AND ISSUE THE DENSE FOG ADVISORY (NPW) PRODUCT. HRRR AND MOS
SUGGESTING THE GREATEST POTENTIAL FOR DENSE FOG ACROSS WEST CENTRAL
KANSAS THIS MORNING. THIS IS ALSO REFLECTED IN 00Z NAM BUFKIT DATA.
THIS DENSE FOG IS IN ASSOCIATION WITH MODERATE DEWPOINTS (LOW 50S
DEG F) AND UPSLOPE E/SE FLOW ALONG AND AHEAD OF A WARM FRONT THAT
WILL MOVE ACROSS THE NORTHERN COUNTIES THROUGH MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 349 PM CDT WED MAR 28 2012
THE 12Z UPPER AIR ANALYSIS SHOWED A FLAT RIDGE OVER THE CENTRAL
UNITED STATES AHEAD OF A STRONG SHORTWAVE TROUGH THAT IS MOVING
ONSHORE OVER IN THE WEST. AT THE SURFACE...LOW PRESSURE OVER
NORTHWEST OKLAHOMA HAD SHIFTED NORTH TOWARD CENTRAL KANSAS INTO THE
VICINITY OF LARNED THIS AFTERNOON. A WEAK FRONTAL BOUNDARY HAS ALSO
SHIFTED NORTH WITH THE LOW AND EXTENDS INTO EASTERN KANSAS. A
STRONGER FRONTAL BOUNDARY WAS ALONG THE NEBRASKA/KANSAS BORDER. SOME
ELEVATED THUNDERSTORMS THAT DEVELOPED IN THAT AREA EARLIER TODAY
APPEAR TO BE LOCATED IN AN AREA OF MID LEVEL ASCENT ALONG THE 305K
ISENTROPIC SURFACE. AGREE WITH THE MODELS AND SPC DEPICTION OF THIS
CLUSTER OF STORMS DEVELOPING EAST AND SOUTHEAST ACROSS NORTH CENTRAL
AND NORTHEAST KANSAS AS THE UPGLIDE DEVELOPS INTO THAT AREA. THE NAM
IS ALSO SHOWING A SMALL AREA OF ASCENT DEVELOPING OVER SOUTH CENTRAL
KANSAS THIS EVENING. AM NOT OVERLY CONFIDENT WE WILL SEE ANYTHING
DEVELOP BUT WILL MAINTAIN SOME SMALL POPS GENERALLY EAST OF A LINE
FROM HAYS THROUGH KINSLEY AND MEDICINE LODGE DURING THE LATER
EVENING HOURS.
MOST OF THE ENERGY ASSOCIATED WITH THE SHORTWAVE TROUGH OVER THE
PACIFIC NORTHWEST LIFTS INTO SOUTHERN CANADA LATER TONIGHT AND
THURSDAY. THERE WILL BE SOME SHORTWAVE ENERGY MOVING EAST ACROSS THE
NORTHERN AND CENTRAL PLAINS ON THURSDAY. A SURFACE LOW PRESSURE
TROUGH WILL PUSH THROUGH WESTERN KANSAS DURING THE LATE MORNING AND
AFTERNOON HOURS. THE NAM AND GFS DIFFER ON WHETHER SHOWERS AND
THUNDERSTORMS WILL BREAK OUT ALONG THIS BOUNDARY WHICH MAKES SENSE
GIVEN THAT THE NAM MODEL SOUNDINGS ARE MORE CAPPED THROUGHOUT THE
DAY THAN THE GFS. WILL KEEP THE SLIGHT CHANCE POPS CURRENTLY IN THE
FORECAST GOING THROUGH THE AFTERNOON HOURS GENERALLY EAST OF HIGHWAY
283.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 349 PM CDT WED MAR 28 2012
MEDIUM RANGE MODELS INDICATE A SMALL AMPLITUDE UPPER LEVEL SHORTWAVE
TROUGH TRANSITIONING EAST ACROSS THE NORTHERN AND CENTRAL PLAINS
THURSDAY NIGHT BRINGING THE POSSIBILITY FOR SHOWERS AND THUNDERSTORMS
TO CENTRAL AND PORTIONS OF WESTERN KANSAS THURSDAY EVENING. AN
ATTENDANT COLD FRONT IS PROJECTED TO PUSH INTO WESTERN KANSAS
EARLIER THURSDAY WITH AMPLE LOW LEVEL MOISTURE POOLING AHEAD OF
THE BOUNDARY WITH H85 DEWPOINTS UP NEAR 10C. NAM AND GFS MODEL
SOUNDINGS SHOW PLENTY OF INSTABILITY AHEAD OF A DEVELOPING DRYLINE
WITH CAPE VALUES IN EXCESS OF 1500J/KG. HOWEVER, ONE ISSUE OF
CONCERN HAS ALL MODELS POINTING TO A FAIRLY WEAK WESTERLY FLOW ALOFT
ACROSS THE CENTRAL PLAINS WHICH MAY LIMIT THE STRENGTH CAPABILITY OF
ANY STORM DEVELOPMENT. STILL, WITH SOME UNCERTAINTY REMAINING AS TO
THE TIMING AND POSITIONING OF THE FRONTAL BOUNDARY, THE BEST CHANCE
FOR SHOWERS AND THUNDERSTORMS LOOKS TO BE ACROSS SOUTH CENTRAL
KANSAS THURSDAY EVENING. UPPER LEVEL RIDGING IS THEN EXPECTED TO
BUILD AS IT MOVES EAST ACROSS THE INTERMOUNTAIN WEST INTO THE
CENTRAL PLAINS THROUGH THE WEEKEND BRINGING ABOUT DRIER CONDITIONS
TO WESTERN KANSAS THROUGH AT LEAST EARLY SUNDAY. THE GFS AND ECMWF
INDICATE AN UPPER LEVEL TROUGH PUSHING ACROSS THE INTERMOUNTAIN
WEST LATE IN THE WEEKEND BRINGING THE NEXT REASONABLE CHANCE FOR
PRECIP TO WESTERN KANSAS EARLY NEXT WEEK.
TEMPERATURES ARE EXPECTED TO BE JUST ABOVE NORMAL FRIDAY EVEN IN
WAKE OF A COLD FRONTAL PASSAGE LATE THURSDAY. THE NAM, GFS, AND
ECMWF SHOW ONLY MARGINALLY COOLER AIR FILTERING INTO WESTERN KANSAS
WITH H85 TEMPERATURES MAINLY IN THE MID TO UPPER TEENS(C). LOOK FOR
HIGHS UP INTO THE 70S(F) FRIDAY AFTERNOON. A GRADUAL WARMING TREND
IS LIKELY THROUGH THE WEEKEND AS UPPER LEVEL RIDGING MOVES IN FROM
THE INTERMOUNTAIN WEST. EXPECT HIGHS UP INTO THE 80S(F) SATURDAY AND
SUNDAY AS A STRENGTHENING LEE SIDE TROUGH OF LOW PRESSURE ENHANCES
WARM AIR ADVECTION INTO WESTERN KANSAS WITHIN A STRONG SOUTHERLY LOW
LEVEL FLOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1230 AM CDT THU MAR 29 2012
MAIN CONCERN FOR THE 06Z TAFS WAS TO REDUCE CIGS, PARTICULARLY AT
KHYS IN ASSOCIATION WITH REDUCED VISIBILITIES FROM DENSE FOG. BUFKIT,
MOS, AND HRRR LOW LEVEL RH`S FIELDS SUGGEST FOG DEVELOPING THIS MORNING
AND BECOMING DENSE A FEW HOURS CENTERED AROUND SUNRISE. LIFR CIGS EXPECTED
FOR KHYS. HAVE LOWER CONFIDENCE FOR KDDC AND KGCK AND KEPT CIGS IN MVFR
CONDITIONS. DRY AIR ADVECTION WILL SPREAD ACROSS THE REGION BEHIND AND
IN ASSOCIATION WITH A TRAVERSING SFC LOW BY LATE MORNING. CIGS SHOULD
IMPROVE TO VFR BY THAT TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 50 79 51 83 / 10 10 10 0
GCK 47 79 50 83 / 10 10 10 0
EHA 46 79 48 83 / 10 10 10 0
LBL 48 80 49 83 / 10 10 10 0
HYS 49 79 51 83 / 10 10 10 0
P28 55 79 53 82 / 20 10 10 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY FROM 5 AM TO 10 AM CDT THIS MORNING FOR
KSZ030-031-043>046.
&&
$$
UPDATE...SUGDEN
SHORT TERM...GERARD
LONG TERM....JJOHNSON
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1205 AM CDT THU MAR 29 2012
...AVIATION UPDATE...
.DISCUSSION...
SEE PREV DISCUSSION.
&&
.AVIATION...
UNCERTAIN THAT GROUND FOG WILL DEVELOP...BUT THERE IS STILL SOME
HINT OF IT FROM THE OBJECTIVE MOS GUIDANCE...SO WILL KEEP A TEMPO
FOR MVFR VSBY AROUND SUNRISE. OTHERWISE THINK SUBSIDENCE FROM THE
MCV WILL LIMIT ADDITIONAL CONVECTION OVERNIGHT. STORMS WILL BE
POSSIBLE AGAIN LATE THURSDAY AFTERNOON AS A COLD FRONT SWEEPS
THROUGH.
WOLTERS
&&
.PREV DISCUSSION... /636 PM CDT WED MAR 28 2012/
LATEST SFC ANALYSIS SUGGESTS THE WARM FRONT HAS BECOME A LITTLE MORE
DIFFUSE OVER THE LAST HOUR. THERE IS STILL PLENTY OF INSTABILITY FOR
STORM DEVELOPMENT BUT 0 TO 1 KM SHEAR REMAINS MARGINAL. HOWEVER AS
SEEN WITH RECENT STORMS...DEEP LAYER SHEAR IS GOOD ENOUGH FOR
SUPERCELL DEVELOPMENT. THE CONCERN IS WHEN THE LOW LEVEL JET
DEVELOPS THIS EVENING. LOW LEVEL SHEAR COULD INCREASE AND ANY STORM
ROOTED IN THE BOUNDARY LAYER MAY BE ABLE TO FEED OFF OF THE
INCREASED SHEAR. EXPECT SEVERE THUNDERSTORM HAZARDS OF HAIL AND
POTENTIAL AN ISOLATED TORNADO TO PERSIST WELL INTO THE EVENING.
WOLTERS
/324 PM CDT WED MAR 28 2012/
ZONAL MID AND UPPER LEVEL FLOW WAS NOTED ACROSS THE CENTRAL AND
SOUTHERN PLAINS. A MINOR H5 TROUGH WAS MOVING INTO NORTHWEST KS THIS
AFTERNOON.
AT 19Z...A WEAK SFC LOW WAS LOCATED NORTHEAST OF DDC. A WARM FRONT
FRONT EXTEND EAST-NORTHEAST FROM THE SFC LOW ACROSS CENTRAL AND
NORTHEAST KS. THE SFC WARM FRONT WAS LOCATED ABOUT 20 MILES NORTH OF
I-70. SOUTH OF THE SFC WARM FRONT DEWPOINTS WERE IN THE LOWER 60S
AND SBCAPE WAS IN THE 2,000 TO 2,500 J/KG RANGE. AS TEMPERATURES
WARM LATER THIS AFTERNOON...SBCAPE WILL INCREASE TO 3,000 TO 3,500
J/KG ACROSS THE SOUTHERN HALF OF THE CWA.
ELEVATED THUNDERSTORMS HAVE DEVELOPED NORTH OF THE WARM FRONT ACROSS
SOUTH CENTRAL NE THIS AFTERNOON. THIS AREA OF STORMS WILL EXPAND
EAST AND SOUTHEAST ACROSS NORTH CENTRAL KS LATE THIS AFTERNOON. ONCE
THE STORMS REACH THE WARM SECTOR THE NEW UPDRAFTS WILL BECOME
ROOTED IN THE BOUNDARY LAYER. 0-6KM BULK SHEAR WILL BE ABOUT 40 TO
50 KTS LATE THIS AFTERNOON AND THROUGH THE EVENING HOURS ACROSS THE
CWA. GIVEN THE MODERATE VERTICAL WIND SHEAR AND
INSTABILITY...THUNDERSTORM UPDRAFTS THAT DEVELOP ALONG AND SOUTH OF
THE WARM FRONT WILL ROTATE. THE SUPERCELL THUNDERSTORMS WILL BE
CAPABLE OF PRODUCING LARGE HAIL...MAY BE UP TO BASEBALL SIZE...AND
DAMAGING OUTFLOW WINDS. THE LOW-LEVEL VERTICAL WIND SHEAR IS
WEAKER...THUS TORNADO PROBABILITIES WILL BE LOW. HOWEVER...LATE THIS
AFTERNOON AND EARLY THIS EVENING ACROSS NORTH CENTRAL KS BRIEF
TORNADOES MAY BE POSSIBLE WITH ANY ISOLATED SUPERCELLS. ALSO, IF
SUPERCELLS ARE ISOLATED ACROSS EAST CENTRAL KS THE RUC AND NAM
MODELS SHOW THE BACKED LOW-LEVEL JET INCREASING TO 30 TO 40
KTS...WHICH WOULD PROVIDE A BETTER ENVIRONMENT FOR ANY ISOLATED
SUPERCELL TO PRODUCE TORNADOES FROM 1Z TO 4Z.
AS THE EVENING PROGRESSES THE ISOLATED TO SCATTERED SUPERCELL
THUNDERSTORMS MAY CONGEAL INTO SEGMENTED SQUALL LINES OR QLCS`S.
INDIVIDUAL UPDRAFTS MAY BE STRONG ENOUGH FOR LARGE HAIL...AND THE
THREAT FOR DAMAGING WINDS MAY INCREASE WITH THE DEVELOPMENT OF A
QLCS THROUGH THE EVENING HOURS ACROSS THE REMAINDER OF THE CWA. THE
BEST CHANCES FOR THUNDERSTORMS THIS EVENING WILL BE ALONG AND NORTH
OF THE WARM FRONT...WHICH WILL BE ABOUT I-70 NORTH TO THE NE BORDER.
THOUGH STORMS WILL DEVELOP SOUTHEAST ACROSS THE REMAINDER OF THE CWA
DURING THE LATE EVENING HOURS. THE THREAT FOR SEVERE WEATHER SHOULD
DECREASE AFTER MIDNIGHT AS THE INSTABILITY DECREASES. IF A QLCS
DEVELOPS THAN HEAVY RAINFALL MAY BE POSSIBLE LATER THIS EVENING
ACROSS NORTHEAST AND EAST CENTRAL KS.
THURSDAY...A MORE AMPLIFIED H5 TROUGH WILL MOVE ACROSS THE CENTRAL
PLAINS DURING THE AFTERNOON HOURS. A SFC COLD FRONT WILL PUSH
SOUTHEAST ACROSS NORTH CENTRAL KS BY AFTERNOON. SCATTERED
THUNDERSTORMS WILL ONCE AGAIN DEVELOP ALONG AND AHEAD OF THE COLD
FRONT. THE 12Z NAM MODEL FORECAST SBCAPE TO INCREASE TO AROUND 3,000
J/KG ACROSS THE WARM SECTOR. THUNDERSTORMS THAT DEVELOP MAY BECOME
SEVERE. THE 0-6KM BULK SHEAR WILL BE A BIT STRONGER AHEAD OF THE H5
TROUGH BUT THE LOW-LEVEL WINDS AHEAD OF THE COLD FRONT WILL VEER
THROUGH THE AFTERNOON. THEREFORE...THE PRIMARY HAZARD WITH ANY
SUPERCELL THUNDERSTORM OR SQUALL LINE WILL BE LARGE HAIL AND
DAMAGING OUTFLOW WINDS. SKIES WILL CLEAR BY MID MORNING INTO THE
EARLY AFTERNOON HOURS. THUS THE INSOLATION AND SOUTHERLY WINDS AHEAD
OF THE COLD FRONT WILL HELP HIGH TEMPERATURES TO REACH THE UPPER 70S
TO LOWER 80S ACROSS THE CWA. IF THE SFC FRONT MOVES A BIT FASTER
THEN NORTH CENTRAL KS MAY BE A FEW DEGREES COOLER.
GARGAN
CONVECTION TIED TO COLD FRONT EXPECTED TO MOVE OUT OF EASTERN
KANSAS THURSDAY NIGHT...WITH CLEARING SKIES FOR FRIDAY. MUCH ABOVE
NORMAL TEMPERATURES SHOULD CONTINUE THROUGH THE WEEKEND.
NEXT CHANCE FOR PRECIPITATION WILL OCCUR WITH A STRONGER COLD
FRONT COMING THROUGH SUNDAY NIGHT AS DEEP UPPER TROUGH MOVES
ACROSS THE PLAINS. SOME WRAPAROUND SHOWERS LOOK LIKE THEY WILL
LINGER INTO MONDAY ASSOCIATED WITH THE COLD AIR ALOFT BEHIND THE
FRONT.
TEMPERATURES TUESDAY MORNING COULD FALL INTO THE 30S BEHIND THAT
SYSTEM...BUT WITH EXPECTED MIXING CONTINUING OVERNIGHT...WOULD
NOT THINK THAT FROST WOULD BE LIKELY.
DRY CONDITIONS AND A GRADUAL WARMUP IS THEN IN STORE FOR THE
MIDDLE OF THE WEEK.
60
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1155 PM CDT WED MAR 28 2012
.UPDATE...
REST OF TONIGHT:
ONE FINAL UPDATE HAS BEEN ISSUED TO CANCEL SVR #114 FROM GREENWOOD...
WOODSON & ALLEN COUNTIES AS TSRA QUICKLY DISSIPATED IN RESPONSE TO
EQUALLY RAPID AIRMASS STABILIZATION. ALL POPS/WX/QPF GRIDS HAVE
LIKEWISE BEEN UPDATED TO REFLECT THESE MOST RECENT TRENDS. THERE STILL
REMAINS SOME CONCERN FOR LIGHT FOG DEVELOPMENT 4-5AM WITH 2SM BR VSBYS
POSSIBLE. ANY FOG THAT DOES DEVELOP WOULD DISSIPATE BY 9AM CDT.
&&
.PREV DISCUSSION... /ISSUED 1010 PM CDT WED MAR 28 2012/
MESOSCALE/CONVECTIVE UPDATE...
NEARLY STATIONARY SVR TSRA CELL ~30NM IN DIAMETER REMAINS CAMPED OVER
NE 1/3 OF GREENWOOD COUNTY WHERE TENNISBALL-SIZED HAIL & FLASH FLOOD-
PRODUCING TORRENTIAL RAINS WILL CONTINUE TO PLAGUE THE COUNTY THROUGH
MID-NIGHT & LIKELY BEYOND. STILL ANTICIPATE SOME ESE PROPAGATION AS
LOW-LVL JET CONTINUES TO STRENGTHEN FROM CNTRL OK N/NE ACROSS SE KS.
SHARPENED POPS/WX/QPF GRIDS THROUGH MID-NIGHT TO FURTHER REFINE MOST
RECENT CONVECTIVE TRENDS...NO DOUBT FOCUSING GREENWOOD & WOODSON
COUNTIES. FURTHER REFINEMENT IS LIKELY FROM MID- NGT THROUGH 7 AM CDT.
STAY TUNED.
AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
IMMEDIATE FOCUS (NO PUN INTENDED) IS ON WHAT HAS BECOME AN ISOLD SVR
TSRA (CAPABLE OF VERY LARGE HAIL & ++RA) OCCURRING OVER NRN GREENWOOD
COUNTY. FOR NOW CELL REMAINS NEARLY STATIONARY BUT CONTINUED CONCERN
THAT CELL COULD SLOWLY PROPAGATE E/SE TOWARD KCNU EARLY THU MORNING.
FOR NOW PLAN IS TO KEEP "VCTS" ASSIGNED TO KCNU & BE QUICK TO UPDATE
THE MOMENT DOPPLER TRENDS INDICATE E/SE EXPANSION TO BE FURTHER THAN
PICTURED AT THIS TIME.
SECOND FOCUS IS ON POTENTIAL FOR 1,000-1,500FT CIGS & 4-5SM VSBYS LATE
TONIGHT/EARLY THU MORNING AS WEAK LWR-DECK TROF AXIS REMAINS SITUATED
OVER WRN KS. RADIATIONAL COOLING COUPLED WITH CONTINUED NWD SURGING
GULF MOISTURE SHOULD KEEP ALL 5 TERMINALS IN MVFR STATUS 10Z-14Z WITH
ALL 5 TERMINALS RETURNING TO VFR STATUS BY 15Z.
PREV DISCUSSION... /ISSUED 834 PM CDT WED MAR 28 2012/
MESOSCALE/CONVECTIVE UPDATE...
CLUSTER OF SVR TSRA CONTINUES TO BUILD/PROPAGATE SLOWLY E/SE FROM
GREENWOOD TOWARD WOODSON & ALLEN COUNTIES ALONG FAIRLY WELL-DEFINED
SFC-850MB MOISTURE AXIS ORIENTED ALONG WEAK ELEVATED FRONTAL BOUNDARY.
AS SUCH SVR #114 HAS BEEN ISSUED FOR ALL 3 COUNTIES TIL MID-NIGHT. THE
VERY SLOW MOVEMENT OF THE CELLS NO DOUBT PRODUCES AN INCREASED THREAT
FOR LOCALIZED FLOODING FROM NRN GREENWOOD TO NRN WOODSON COUNTIES. ALL
WX/POPS/QPF HAVE BEEN FINE-TUNED.
PREV DISCUSSION... /ISSUED 308 PM CDT WED MAR 28 2012/
DISCUSSION...
THE PRIMARY FOCUS CONTINUES TO BE PERIODIC THUNDERSTORM CHANCES
THROUGH THE WEEK.
A BROAD MID/UPPER RIDGE WAS COVERING MUCH OF THE CENTRAL AND SOUTHERN
CONUS WHILE A SUBTLE SHORTWAVE TROUGH WAS MOVING OVER SOUTHERN
KANSAS EARLY THIS AFTERNOON. THE WARM FRONT HAS BECOME DIFFUSE
MOST EVIDENT IN THE TD SPREADS LOCATED NEAR I-70 EARLY THIS
AFTERNOON. STRONG CINH IS EXPECTED TO PRECLUDE MORE WIDESPREAD
THUNDERSTORM DEVELOPMENT FURTHER SOUTH ALONG THE DRY LINE THIS
AFTERNOON/EARLY EVENING BUT MAINTAINED HIGHER POPS ALONG AND NORTH
OF THE DIFFUSE WARM FRONT BORDERING TOP CWA THIS EVENING/TONIGHT AS
STRONGER 305K ISENTROPIC UPGLIDE BECOMES JUXTAPOSED ALONG THE NOSE
OF THE LLJ. THE LATEST HRRR KEEPS THE MAIN AREA OF CONVECTION WELL
NORTH OF THE FORECAST AREA...BUT MAINTAINED MID POPS ACROSS MUCH OF
CENTRAL KANSAS WHERE THE ACTIVITY MAY DEVELOP BEFORE SHIFTING
EASTWARD OUT OF THE AREA AFTER 09-11Z OR EARLIER. ANY STORMS THAT
DEVELOP THROUGH TONIGHT MAY BECOME SEVERE WITH LARGE HAIL AND
DAMAGING WINDS.
THU-SUN...ABOVE NORMAL TEMPERATURES ARE ANTICIPATED THROUGH THE
PERIOD WITH ANOTHER OPPORTUNITY FOR DEEP MOIST CONVECTION LATE
THURSDAY AFTERNOON/THURSDAY NIGHT AS A SHORT WAVE TROUGH TRANSLATES
RAPIDLY EAST OVER THE AREA. THE NAM IS MUCH MORE PROGRESSIVE WITH
THE SFC TROUGH AXIS AND TRENDED POPS FURTHER EAST COMPARED TO THE
PREVIOUS FORECAST KEEPING THE HIGHEST PROBABILITIES ALONG/EAST OF
THE KANSAS TURNPIKE. SHORTWAVE RIDGING IS PROGGED TO RETURN TO THE
CENTRAL PLAINS FRI-SAT LEADING TO FAIR WEATHER AND CONTINUED ABOVE
NORMAL TEMPERATURES. TRENDED HIGHS ON FRI-SUN SLIGHTLY HIGHER WITH
READINGS CLIMBING INTO THE LOW-MID 80S SAT-SUN.
MON-WED...ANOTHER MORE ROBUST MID/UPPER TROUGH WILL RACE EASTWARD
ACROSS THE CENTRAL PLAINS LATE SUNDAY INTO MONDAY BRINGING A RETURN
TO SEASONABLE TEMPERATURES IN THE 60S INTO THE BEGINNING OF NEXT
WEEK. PRECIPITATION CHANCES CONTINUE TO LOOK SLIM GIVIN THE
PROGRESSIVE NATURE OF THE MID/UPPER TROUGH WITH A RETURN TO ABOVE
NORMAL TEMPERATURES TOWARD THE MIDDLE OF THE WEEK.
FIRE WEATHER...
A TROUGH OF LOW PRESSURE WILL DEVELOP ACROSS CENTRAL KANSAS ON
THURSDAY WITH WIDELY SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE
ALONG AND EAST OF THIS TROUGH. FURTHER WEST...LOW RELATIVE
HUMIDITIES MAY COMBINE WITH GUSTY SOUTHWEST WINDS CREATING NEAR
CRITICAL FIRE WEATHER CONDITIONS AT TIMES DURING THE AFTERNOON HOURS
ON THURSDAY. GUSTY SOUTHWEST WINDS WILL RETURN LATE IN THE WEEKEND
AHEAD OF A STRONG STORM SYSTEM MOVING OVER THE ROCKIES. GUSTY NORTHWEST
WINDS WILL FOLLOW THE PASSAGE OF A COLD FRONT LATE SUNDAY
NIGHT/EARLY MONDAY WITH A RETURN TO MORE SEASONABLE TEMPERATURES FOR
THE BEGINNING OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 61 85 56 79 / 20 30 20 10
HUTCHINSON 60 83 54 78 / 10 20 20 10
NEWTON 60 82 57 78 / 30 20 20 10
ELDORADO 61 84 59 79 / 30 30 30 10
WINFIELD-KWLD 62 85 58 81 / 20 20 40 10
RUSSELL 55 80 49 79 / 20 20 20 10
GREAT BEND 58 81 51 78 / 10 20 20 10
SALINA 59 83 54 80 / 40 20 20 10
MCPHERSON 61 82 54 79 / 20 20 20 10
COFFEYVILLE 63 85 59 81 / 30 20 60 20
CHANUTE 61 84 59 81 / 70 20 60 10
IOLA 61 83 59 81 / 70 20 60 10
PARSONS-KPPF 62 85 59 80 / 40 20 60 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1013 PM EDT FRI MAR 30 2012
.Forecast Update...
Issued at 1010 PM EDT Mar 30 2012
Strong to marginally severe storms with hail were across southern
Indiana as of 2Z. Several reports of pea to dime size hail have
been received with one report of quarter size hail in Austin, IN
which has been the strongest storm in our area so far. Expect
strong to marginally severe storms to continue through around 1AM
EDT before diminishing to garden variety t-storms as the line
continues to sink south into Kentucky and weaken. Only made some
minor tweaks to POPs, dewpts, and temps based on current trends this
evening. Temperatures should hold in the 50s for lows tonight.
After it gets done raining, we may see a period of only partly
cloudy or even clear skies. With plentiful moisture at the sfc,
this may allow for some light fog to form. However, don`t expect
any widespread fog due to the mixey nature of the atmosphere so will
leave fog out of the forecast as of now. Also, any clearing would
be brief as upstream obs as well as soundings indicate a good
stratus layer will build into the area before sunrise and stick
around through the morning hours.
Update issued at 840 PM EDT Mar 30 2012
A line of showers/t-storms ahead of/along a sfc cold front was
making steady progress southeast into our area this evening. These
storms have decreased in intensity somewhat and thus a severe
t-storm watch was not issued. Latest model trends indicated that it
will continue to sink south throughout the evening hours and weaken
as it does so. Still think portions of southern Indiana and
northern KY may see some strong storms with small hail and 40 mph
winds, but any severe threat should be diminishing this evening.
Updated the grids to reflect the latest timing of this line of
showers/storms through the forecast area tonight. Also, tweaked
cloud cover overnight to better match the line of storms, some brief
clearing just behind the front, and then low stratus that is
anticipated just before sunrise through early afternoon.
.Short Term (This Afternoon through Saturday Night)...
Issued at 405 PM EDT Mar 30 2012
Afternoon satellite imagery and observations reveal that the warm
front has moved well north of our forecast area. South of this warm
front, the atmosphere continues to destabilize with time. With
current temperatures in the upper 70s to the lower 80s and dewpoints
in the upper 50s to the lower 60s is resulting in mixed layer CAPE
values in the 1250-1750 J/Kg range. Surface lifted indices based
on RUC proximity soundings are running around -4 to -6 degrees
Celsius. Atmosphere remains generally uncapped across the
southeastern/eastern sections of the forecast area. However some
weak capping/CINH still exists out in areas west of I-65.
Sufficient mixing over the next few hours will likely mix that cap
out.
For the rest of the afternoon, we expect partly to mostly sunny
skies with isolated showers and thunderstorms being possible across
portions of the area. The greatest concentration of convection will
generally be east of I-65 where we have a local maxima in the
dewpoint field. Temperatures will remain in the upper 70s and lower
80s through the early evening before dropping into the upper 70s
toward sunset.
As for tonight, the latest high resolution models agree that
convection will continue to develop along a southward moving cold
front which is currently located across central IL, IN, and OH.
This line of convection will likely move eastward as it will be
embedded in the faster mid-level low aloft. However, the line will
slowly sag southward with time. The consensus of the latest models
have trended slower as they adjust to the initial conditions that
are being ingested into the model. Therefore, the slower solution
would keep the bulk of this thunderstorm activity concentrated north
of the Ohio River early this evening. Current thinking is that the
line will likely sag southward to near the Ohio River by 10-11 PM
EDT. As this line head south, it will be encountering a slowly
stabilizing airmass due to the loss of heating and nocturnal PBL
stabilization.
Despite the weaker instability, this line of storms should remain
largely intact as it approaches the Ohio River later this evening.
The main threats still appear to be damaging winds and large hail.
The tornado threat appears to be rather low across our area as
overall bulk shear values decrease the further south you go of the
Ohio River. As the line passes south of the Ohio River, expect the
line to weaken and gradually dissipate as it sinks further south
into KY. For this reason, we will keep highest PoP chances tonight
across southern Indiana and the northern parts of KY and have lesser
chances across southern KY. Overnight lows will cool into the
mid-upper 50s.
Surface frontal boundary is expected to push south of the state
early Saturday with high pressure building into the region. Partly
to mostly sunny skies are expected with highs topping out in the
upper 60s in the Bluegrass region and lower 70s in the central.
Warmest temperatures will be across the south/southwest with
mid-upper 70s. Overnight lows Saturday night will be in the upper
30s-lower 40s in the northeast with mid-upper 40s elsewhere.
.Long Term (Sunday through Friday)...
Updated at 330 PM EDT Mar 30 2012
Ohio Valley will be positioned in northwest mid level flow between
ridging over the south central CONUS and shortwave moving from the
eastern Great Lakes to New England on Sunday. Surface low associated
with northeast shortwave will drag a cold front south toward the
Ohio River by Sunday afternoon. At this point, will continue to keep
forecast dry however may have to eventually add low chance pops
across northern CWA for afternoon showers and storms. Looking for
highs in the low 80s on Sunday as skies stay mostly sunny to partly
cloudy.
Ridge axis slides east to the middle Mississippi River Valley Sunday
night with frontal boundary mentioned above sliding southwest over
the CWA from a backdoor entrance. Front then looks to stall as it
becomes parallel to the mid level flow. Will also continue to keep
this period dry as models do not show enough deep moisture to
warrant pops at this time. Could see a nice gradient in low
temperatures on Sunday night dependent on how much progress front
makes. Will go with low 60s west to upper 50s east.
Closed upper low will make its way to the southern plains on Monday
with surface low developing over the middle Mississippi River
Valley. The resultant tightening pressure gradient will create
steady southwesterly flow and likely lift stalled frontal boundary
back northeast as a warm front. Will include slight chance for a
shower or thunderstorm as this occurs. This will be the warmest day
of the period with low to mid 80s.
Will likely see a lull in activity sometime Monday evening before
more widespread precipitation moves over the area through midweek.
That being said, will leave chance pops in the east for departing
warm front induced showers and storms and uncertainty in timing.
Lows around 60 can be expected.
Confidence in forecast decreases from Tuesday on as models continue
to have trouble with timing on closed upper low meandering from the
southern Plains to the Tennessee Valley or the Gulf Coast states.
Adding to the uncertainty, models disagree on northern stream energy
and its associated surface features dragging a cold front through.
ECMWF is more aggressive with front, dragging it through the region
by Tuesday night, with closed upper low slower and further south.
Meanwhile, GFS/GEM are faster with the upper low which combines the
ample Gulf moisture with the front sagging south from northern
stream system. This scenarios could result from the differing model
solutions. 1.) The ECMWF solution would result in a quick-hitting
shower and storm episode from Tuesday afternoon through Wednesday
morning. 2.) The GFS/GEM solution would bring a prolonged
precipitation event from Tuesday afternoon through at least Thursday
evening as upper low would be further north and slower to move
through. Will lean toward the first solution at this point with best
chances for showers and storms Tuesday afternoon through Wednesday
morning. Thereafter, will keep forecast dry until models converge
on a solution.
Looking for a cool down from midweek with either solution as we will
either be in a post frontal cooler airmass or underneath the
influence of an upper low. Highs in the mid 60s each day with lows
in the mid 40s.
&&
.Aviation (00Z TAF Issuance)...
Updated at 700 PM EDT Mar 30 2012
As of 2245Z, strong to severe convection existed along a sfc cold
front from southeast Missouri to northern Ohio. This convection
oriented along a SW to NE line was moving east trailing the main low
pressure in Ohio. This convection is schedule to sink south this
evening into our TAF sites. The latest time of arrival looks to be
around 2Z at SDF...3Z at LEX...and 4Z at BWG respectively.
Convection may arrive a little earlier than the progged times if
individual storms and outflow boundaries cause it to build south
faster. We`re starting to see a little bit of this with the storms
near IND as of 2345Z. At SDF/LEX, strong to possibly severe storms
are expected, therefore, did go ahead and upgrade to -TSRA with more
wind/vsby details forth coming as we get closer to the arrival
time. The line is supposed to weaken somewhat throughout the
evening hours so it`s tough to say how strong storms will be by the
time they reach the TAF sites. In anticipation of storms being much
weaker by the time they reach BWG, only have -SHRA with VCTS in
there for tonight. After about a 4 hour window of possible
convection, the front should move through the TAF sites shifting
winds to the west around 6Z at SDF...7Z at LEX...and 8Z at BWG
respectively. Upstream obs and 18Z NAM soundings then suggest a
brief period of only scattered clouds or even no clouds before low
stratus and light BR start to build in behind the front. Expect
MVFR conditions to develop before sunrise and last through much of
the morning hours. By early afternoon, conditions should improve to
VFR with CIGS scattering out and winds becoming more northerly for
the rest of the day around 6-7 kts.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........AMS
Short Term.......MJ
Long Term........BJS
Aviation.........AMS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
843 PM EDT FRI MAR 30 2012
.Forecast Update...
Issued at 840 PM EDT Mar 30 2012
A line of showers/t-storms ahead of/along a sfc cold front was
making steady progress southeast into our area this evening. These
storms have decreased in intensity somewhat and thus a severe
t-storm watch was not issued. Latest model trends indicated that it
will continue to sink south throughout the evening hours and weaken
as it does so. Still think portions of southern Indiana and
northern KY may see some strong storms with small hail and 40 mph
winds, but any severe threat should be diminishing this evening.
Updated the grids to reflect the latest timing of this line of
showers/storms through the forecast area tonight. Also, tweaked
cloud cover overnight to better match the line of storms, some brief
clearing just behind the front, and then low stratus that is
anticipated just before sunrise through early afternoon.
.Short Term (This Afternoon through Saturday Night)...
Issued at 405 PM EDT Mar 30 2012
Afternoon satellite imagery and observations reveal that the warm
front has moved well north of our forecast area. South of this warm
front, the atmosphere continues to destabilize with time. With
current temperatures in the upper 70s to the lower 80s and dewpoints
in the upper 50s to the lower 60s is resulting in mixed layer CAPE
values in the 1250-1750 J/Kg range. Surface lifted indices based
on RUC proximity soundings are running around -4 to -6 degrees
Celsius. Atmosphere remains generally uncapped across the
southeastern/eastern sections of the forecast area. However some
weak capping/CINH still exists out in areas west of I-65.
Sufficient mixing over the next few hours will likely mix that cap
out.
For the rest of the afternoon, we expect partly to mostly sunny
skies with isolated showers and thunderstorms being possible across
portions of the area. The greatest concentration of convection will
generally be east of I-65 where we have a local maxima in the
dewpoint field. Temperatures will remain in the upper 70s and lower
80s through the early evening before dropping into the upper 70s
toward sunset.
As for tonight, the latest high resolution models agree that
convection will continue to develop along a southward moving cold
front which is currently located across central IL, IN, and OH.
This line of convection will likely move eastward as it will be
embedded in the faster mid-level low aloft. However, the line will
slowly sag southward with time. The consensus of the latest models
have trended slower as they adjust to the initial conditions that
are being ingested into the model. Therefore, the slower solution
would keep the bulk of this thunderstorm activity concentrated north
of the Ohio River early this evening. Current thinking is that the
line will likely sag southward to near the Ohio River by 10-11 PM
EDT. As this line head south, it will be encountering a slowly
stabilizing airmass due to the loss of heating and nocturnal PBL
stabilization.
Despite the weaker instability, this line of storms should remain
largely intact as it approaches the Ohio River later this evening.
The main threats still appear to be damaging winds and large hail.
The tornado threat appears to be rather low across our area as
overall bulk shear values decrease the further south you go of the
Ohio River. As the line passes south of the Ohio River, expect the
line to weaken and gradually dissipate as it sinks further south
into KY. For this reason, we will keep highest PoP chances tonight
across southern Indiana and the northern parts of KY and have lesser
chances across southern KY. Overnight lows will cool into the
mid-upper 50s.
Surface frontal boundary is expected to push south of the state
early Saturday with high pressure building into the region. Partly
to mostly sunny skies are expected with highs topping out in the
upper 60s in the Bluegrass region and lower 70s in the central.
Warmest temperatures will be across the south/southwest with
mid-upper 70s. Overnight lows Saturday night will be in the upper
30s-lower 40s in the northeast with mid-upper 40s elsewhere.
.Long Term (Sunday through Friday)...
Updated at 330 PM EDT Mar 30 2012
Ohio Valley will be positioned in northwest mid level flow between
ridging over the south central CONUS and shortwave moving from the
eastern Great Lakes to New England on Sunday. Surface low associated
with northeast shortwave will drag a cold front south toward the
Ohio River by Sunday afternoon. At this point, will continue to keep
forecast dry however may have to eventually add low chance pops
across northern CWA for afternoon showers and storms. Looking for
highs in the low 80s on Sunday as skies stay mostly sunny to partly
cloudy.
Ridge axis slides east to the middle Mississippi River Valley Sunday
night with frontal boundary mentioned above sliding southwest over
the CWA from a backdoor entrance. Front then looks to stall as it
becomes parallel to the mid level flow. Will also continue to keep
this period dry as models do not show enough deep moisture to
warrant pops at this time. Could see a nice gradient in low
temperatures on Sunday night dependent on how much progress front
makes. Will go with low 60s west to upper 50s east.
Closed upper low will make its way to the southern plains on Monday
with surface low developing over the middle Mississippi River
Valley. The resultant tightening pressure gradient will create
steady southwesterly flow and likely lift stalled frontal boundary
back northeast as a warm front. Will include slight chance for a
shower or thunderstorm as this occurs. This will be the warmest day
of the period with low to mid 80s.
Will likely see a lull in activity sometime Monday evening before
more widespread precipitation moves over the area through midweek.
That being said, will leave chance pops in the east for departing
warm front induced showers and storms and uncertainty in timing.
Lows around 60 can be expected.
Confidence in forecast decreases from Tuesday on as models continue
to have trouble with timing on closed upper low meandering from the
southern Plains to the Tennessee Valley or the Gulf Coast states.
Adding to the uncertainty, models disagree on northern stream energy
and its associated surface features dragging a cold front through.
ECMWF is more aggressive with front, dragging it through the region
by Tuesday night, with closed upper low slower and further south.
Meanwhile, GFS/GEM are faster with the upper low which combines the
ample Gulf moisture with the front sagging south from northern
stream system. This scenarios could result from the differing model
solutions. 1.) The ECMWF solution would result in a quick-hitting
shower and storm episode from Tuesday afternoon through Wednesday
morning. 2.) The GFS/GEM solution would bring a prolonged
precipitation event from Tuesday afternoon through at least Thursday
evening as upper low would be further north and slower to move
through. Will lean toward the first solution at this point with best
chances for showers and storms Tuesday afternoon through Wednesday
morning. Thereafter, will keep forecast dry until models converge
on a solution.
Looking for a cool down from midweek with either solution as we will
either be in a post frontal cooler airmass or underneath the
influence of an upper low. Highs in the mid 60s each day with lows
in the mid 40s.
&&
.Aviation (00Z TAF Issuance)...
Updated at 700 PM EDT Mar 30 2012
As of 2245Z, strong to severe convection existed along a sfc cold
front from southeast Missouri to northern Ohio. This convection
oriented along a SW to NE line was moving east trailing the main low
pressure in Ohio. This convection is schedule to sink south this
evening into our TAF sites. The latest time of arrival looks to be
around 2Z at SDF...3Z at LEX...and 4Z at BWG respectively.
Convection may arrive a little earlier than the progged times if
individual storms and outflow boundaries cause it to build south
faster. We`re starting to see a little bit of this with the storms
near IND as of 2345Z. At SDF/LEX, strong to possibly severe storms
are expected, therefore, did go ahead and upgrade to -TSRA with more
wind/vsby details forth coming as we get closer to the arrival
time. The line is supposed to weaken somewhat throughout the
evening hours so it`s tough to say how strong storms will be by the
time they reach the TAF sites. In anticipation of storms being much
weaker by the time they reach BWG, only have -SHRA with VCTS in
there for tonight. After about a 4 hour window of possible
convection, the front should move through the TAF sites shifting
winds to the west around 6Z at SDF...7Z at LEX...and 8Z at BWG
respectively. Upstream obs and 18Z NAM soundings then suggest a
brief period of only scattered clouds or even no clouds before low
stratus and light BR start to build in behind the front. Expect
MVFR conditions to develop before sunrise and last through much of
the morning hours. By early afternoon, conditions should improve to
VFR with CIGS scattering out and winds becoming more northerly for
the rest of the day around 6-7 kts.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........AMS
Short Term.......MJ
Long Term........BJS
Aviation.........AMS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
702 PM EDT FRI MAR 30 2012
.Short Term (This Afternoon through Saturday Night)...
Issued at 405 PM EDT Mar 30 2012
Afternoon satellite imagery and observations reveal that the warm
front has moved well north of our forecast area. South of this warm
front, the atmosphere continues to destabilize with time. With
current temperatures in the upper 70s to the lower 80s and dewpoints
in the upper 50s to the lower 60s is resulting in mixed layer CAPE
values in the 1250-1750 J/Kg range. Surface lifted indices based
on RUC proximity soundings are running around -4 to -6 degrees
Celsius. Atmosphere remains generally uncapped across the
southeastern/eastern sections of the forecast area. However some
weak capping/CINH still exists out in areas west of I-65.
Sufficient mixing over the next few hours will likely mix that cap
out.
For the rest of the afternoon, we expect partly to mostly sunny
skies with isolated showers and thunderstorms being possible across
portions of the area. The greatest concentration of convection will
generally be east of I-65 where we have a local maxima in the
dewpoint field. Temperatures will remain in the upper 70s and lower
80s through the early evening before dropping into the upper 70s
toward sunset.
As for tonight, the latest high resolution models agree that
convection will continue to develop along a southward moving cold
front which is currently located across central IL, IN, and OH.
This line of convection will likely move eastward as it will be
embedded in the faster mid-level low aloft. However, the line will
slowly sag southward with time. The consensus of the latest models
have trended slower as they adjust to the initial conditions that
are being ingested into the model. Therefore, the slower solution
would keep the bulk of this thunderstorm activity concentrated north
of the Ohio River early this evening. Current thinking is that the
line will likely sag southward to near the Ohio River by 10-11 PM
EDT. As this line head south, it will be encountering a slowly
stabilizing airmass due to the loss of heating and nocturnal PBL
stabilization.
Despite the weaker instability, this line of storms should remain
largely intact as it approaches the Ohio River later this evening.
The main threats still appear to be damaging winds and large hail.
The tornado threat appears to be rather low across our area as
overall bulk shear values decrease the further south you go of the
Ohio River. As the line passes south of the Ohio River, expect the
line to weaken and gradually dissipate as it sinks further south
into KY. For this reason, we will keep highest PoP chances tonight
across southern Indiana and the northern parts of KY and have lesser
chances across southern KY. Overnight lows will cool into the
mid-upper 50s.
Surface frontal boundary is expected to push south of the state
early Saturday with high pressure building into the region. Partly
to mostly sunny skies are expected with highs topping out in the
upper 60s in the Bluegrass region and lower 70s in the central.
Warmest temperatures will be across the south/southwest with
mid-upper 70s. Overnight lows Saturday night will be in the upper
30s-lower 40s in the northeast with mid-upper 40s elsewhere.
.Long Term (Sunday through Friday)...
Updated at 330 PM EDT Mar 30 2012
Ohio Valley will be positioned in northwest mid level flow between
ridging over the south central CONUS and shortwave moving from the
eastern Great Lakes to New England on Sunday. Surface low associated
with northeast shortwave will drag a cold front south toward the
Ohio River by Sunday afternoon. At this point, will continue to keep
forecast dry however may have to eventually add low chance pops
across northern CWA for afternoon showers and storms. Looking for
highs in the low 80s on Sunday as skies stay mostly sunny to partly
cloudy.
Ridge axis slides east to the middle Mississippi River Valley Sunday
night with frontal boundary mentioned above sliding southwest over
the CWA from a backdoor entrance. Front then looks to stall as it
becomes parallel to the mid level flow. Will also continue to keep
this period dry as models do not show enough deep moisture to
warrant pops at this time. Could see a nice gradient in low
temperatures on Sunday night dependent on how much progress front
makes. Will go with low 60s west to upper 50s east.
Closed upper low will make its way to the southern plains on Monday
with surface low developing over the middle Mississippi River
Valley. The resultant tightening pressure gradient will create
steady southwesterly flow and likely lift stalled frontal boundary
back northeast as a warm front. Will include slight chance for a
shower or thunderstorm as this occurs. This will be the warmest day
of the period with low to mid 80s.
Will likely see a lull in activity sometime Monday evening before
more widespread precipitation moves over the area through midweek.
That being said, will leave chance pops in the east for departing
warm front induced showers and storms and uncertainty in timing.
Lows around 60 can be expected.
Confidence in forecast decreases from Tuesday on as models continue
to have trouble with timing on closed upper low meandering from the
southern Plains to the Tennessee Valley or the Gulf Coast states.
Adding to the uncertainty, models disagree on northern stream energy
and its associated surface features dragging a cold front through.
ECMWF is more aggressive with front, dragging it through the region
by Tuesday night, with closed upper low slower and further south.
Meanwhile, GFS/GEM are faster with the upper low which combines the
ample Gulf moisture with the front sagging south from northern
stream system. This scenarios could result from the differing model
solutions. 1.) The ECMWF solution would result in a quick-hitting
shower and storm episode from Tuesday afternoon through Wednesday
morning. 2.) The GFS/GEM solution would bring a prolonged
precipitation event from Tuesday afternoon through at least Thursday
evening as upper low would be further north and slower to move
through. Will lean toward the first solution at this point with best
chances for showers and storms Tuesday afternoon through Wednesday
morning. Thereafter, will keep forecast dry until models converge
on a solution.
Looking for a cool down from midweek with either solution as we will
either be in a post frontal cooler airmass or underneath the
influence of an upper low. Highs in the mid 60s each day with lows
in the mid 40s.
&&
.Aviation (00Z TAF Issuance)...
Updated at 700 PM EDT Mar 30 2012
As of 2245Z, strong to severe convection existed along a sfc cold
front from southeast Missouri to northern Ohio. This convection
oriented along a SW to NE line was moving east trailing the main low
pressure in Ohio. This convection is schedule to sink south this
evening into our TAF sites. The latest time of arrival looks to be
around 2Z at SDF...3Z at LEX...and 4Z at BWG respectively.
Convection may arrive a little earlier than the progged times if
individual storms and outflow boundaries cause it to build south
faster. We`re starting to see a little bit of this with the storms
near IND as of 2345Z. At SDF/LEX, strong to possibly severe storms
are expected, therefore, did go ahead and upgrade to -TSRA with more
wind/vsby details forth coming as we get closer to the arrival
time. The line is supposed to weaken somewhat throughout the
evening hours so it`s tough to say how strong storms will be by the
time they reach the TAF sites. In anticipation of storms being much
weaker by the time they reach BWG, only have -SHRA with VCTS in
there for tonight. After about a 4 hour window of possible
convection, the front should move through the TAF sites shifting
winds to the west around 6Z at SDF...7Z at LEX...and 8Z at BWG
respectively. Upstream obs and 18Z NAM soundings then suggest a
brief period of only scattered clouds or even no clouds before low
stratus and light BR start to build in behind the front. Expect
MVFR conditions to develop before sunrise and last through much of
the morning hours. By early afternoon, conditions should improve to
VFR with CIGS scattering out and winds becoming more northerly for
the rest of the day around 6-7 kts.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Short Term.......MJ
Long Term........BJS
Aviation.........AMS
AREA FORECAST DISCUSSION
NWS GRAY ME
1135 PM EDT FRI MAR 30 2012
.SYNOPSIS...
HIGH PRESSURE WILL HOLD OVER NORTHERN NEW ENGLAND TONIGHT AND
SATURDAY AS LOW PRESSURE PASSES SOUTH OF NEW ENGLAND. LOW PRESSURE
CROSSING SOUTHERN CANADA SATURDAY NIGHT WILL DROP SOUTHEAST INTO
WESTERN NEW ENGLAND BY SUNDAY EVENING. LOW PRESSURE WILL CONTINUE
SOUTHEAST MOVING OFF THE NEW ENGLAND COAST SUNDAY NIGHT. HIGH
PRESSURE WILL BUILD IN FROM THE NORTHWEST MONDAY THROUGH TUESDAY.
LOW PRESSURE PASSING SOUTH OF NEW ENGLAND ON WEDNESDAY WILL DRAG A
WEAK COLD FRONT THROUGH THE AREA. HIGH PRESSURE WILL BUILD IN FROM
THE WEST THURSDAY THROUGH FRIDAY.
&&
.NEAR TERM /OVERNIGHT/...
1130PM UPDATE... HAVE UPDATED TO INCREASE LOW TEMPERATURES
ESPECIALLY OVER NORTHERN AREAS. DEWPOINT VALUES ARE IN THE MID TO
UPPER TEENS AND CLOUDS ARE MOVING IN. EXPECT TEMPERATURES TO ONLY
FALL INTO THE LOW 20S TO UPPER TEENS HERE. ALSO MADE MINOR
ADJUSTMENTS TO POP TRENDS OVER THE NEXT FEW HOURS. REGIONAL RADAR
SHOWS BANDS OF PRECIPITATION MOVING INTO VERMONT AND SOUTHERN NEW
HAMPSHIRE... HOWEVER ALMOST NONE OF THIS IS REACHING THE GROUND
YET. STILL EXPECT A CHANCE OF LIGHT SNOW IN SOUTHERN NEW HAMPSHIRE
AS CONDITIONS MOISTEN UP A BIT. DO NOT EXPECT SIGNIFICANT
ACCUMULATIONS.
UPDATE...
ONLY MINOR UPDATES TO THE CURRENT GRIDDED PACKAGE THIS EVENING.
CLOUDS OVER CENTRAL NEW YORK STATE WILL CONTINUE TO PRESS EASTWARD
INTO OUR REGION TONIGHT. BY 05Z-06Z...PERHAPS A FEW FLURRIES WILL
MAKE IT THROUGH THE DRY AIR AND INTO EXTREME SOUTHERN NH. HAVE INCREASED
POPS JUST A TAD BASED ON THE LATEST HRRR MODEL...HOWEVER THEY
STILL REMAIN IN THE CHANCE CATEGORY OVER SOUTHERN NH.
SCAS HAVE BEEN DROPPED AS WINDS NOW BELOW 25 KT.
OTHERWISE...MADE A FEW MINOR ADJUSTMENTS BASED ON CURRENT DEW
POINT AND CLOUD COVER TRENDS.
PREV DISC...
GUSTY NORTHWEST WINDS WILL QUICKLY DROP OFF THIS EVENING AS HIGH
PRESSURE BUILDS IN FROM THE WEST. ASIDE FROM VARIABLE HIGH CLOUDS
ACROSS THE CONNECTICUT VALLEY AND SOUTHERN NEW HAMPSHIRE SHOULD
SEE A MOSTLY CLEAR EVENING. SHORTWAVE DIVING SOUTHEAST THROUGH
WESTERN NEW YORK WILL THICKEN CLOUDS IN SOUTHWEST ZONES THROUGH
MIDNIGHT AND THERE COULD BE A FEW WIDELY SCATTERED SNOW SHOWERS
ACROSS SOUTHWEST NEW HAMPSHIRE AFTER MIDNIGHT. NORTH AND EAST OF
THE PORTLAND AREA SHOULD SEE A MOSTLY CLEAR NIGHT. OVERNIGHT LOWS
WILL RANGE THROUGH THE TEENS IN THE NORTH AND 20S IN THE SOUTH.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
CLOUDS WILL PERSIST FOR MUCH OF THE DAY ACROSS SOUTHERN NEW
HAMPSHIRE AND SOUTHWEST MAINE ON SATURDAY AS LOW PRESSURE PASSES
OUT TO SEA SOUTH OF NEW ENGLAND. MAY SEE SOME RAIN OR SNOW SHOWERS
IN FAR SOUTHERN NEW HAMPSHIRE...ESPECIALLY DURING THE MORNING
HOURS BUT ONCE AGAIN ANY ACTIVITY WILL BE LIGHT AND SPOTTY.
ELSEWHERE SUNSHINE WILL BE FILTERED THROUGH VARIABLE HIGH AND MID
LEVEL CLOUDS...WHICH WILL GRADUALLY DIMINISH IN THE AFTERNOON.
LOOKING FOR HIGHS RANGING THROUGH THE 40S THROUGHOUT THE FORECAST
AREA.
CLOUDS WILL CLEAR ACROSS SOUTHERN NEW HAMPSHIRE SATURDAY NIGHT AND
THE REMAINDER OF THE FORECAST AREA WILL SEE A MOSTLY CLEAR NIGHT
WITH HIGH CLOUDS SPILLING BACK INTO THE REGION TOWARD SUNDAY
MORNING. LOOKING FOR LOWS IN THE UPPER TEENS TO UPPER 20S.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
UPR LVL TROF DROPS SE OUT OF CENTRAL CANADA IN THE NW FLOW
ALOFT... BRINGING A SFC LOW TOWARD THE FCST AREA SUNDAY. THIS
WILL SPREAD CLOUDS THEN PRCP INTO THE FCST AREA...WITH TIMING
STILL UP IN THE AIR AS MODELS CONT TO HAVE THEIR DIFFERENCES...
BOTH BETWEEN EACH MODEL AND WITH EACH RUN.
STILL SHOULD SEE SOME PRCP BEFORE THE END OF THE DAY. PRCP
CONTINUES SUNDAY NGT AS THE LOW TRACKS SE MOVING ACROSS SRN NEW
ENGLAND SUNDAY NGT AND OFF THE COAST ON MONDAY. MODELS BRING IN CD
AIR ALOFT BUT THE LOWER LEVELS AS INDICATED BY H9 TEMPS AND H10 TO
H8 THICKNESS VALUES WRM UP AND WILL LIKELY LEAD TO MOSTLY -RA
THOUGH MORE NRN AND HIGHER ELEVATION AREAS COULD SEE MIXED -RASN
OR EVEN A PERIOD OF -SN /ESPECIALLY TOWARD THE END OF THE EVENT
LATE SUNDAY NGT AS THE LOW MOVES OFFSHORE AND COLDER AIR FILTERS
IN ON NW WINDS/.
THE CD NW FLOW BEHIND THE LOW FOR MONDAY BRINGS IMPROVING WX
AFTER ANY -SHRASN ENDS. COOL DRY WX MONDAY NGT AS AN UPR LVL AND
SFC RIDGE BUILD IN. THESE SYSTEMS GIVE US FAIR WX TUESDAY. ANOTHER
UPR LVL TROF DIGS SE INTO THE REGION TUESDAY NGT. AS THE SYSTEM
INTENSIFIES AND MOVES OVERHEAD ON WEDNESDAY IT CAUSES A SFC LOW TO
DEVELOP AND PASS TO OUR S. PRPC MAY ARRIVE LATE TUESDAY NGT OVER
WRN AREAS. SHOULD SEE A CHC OF PRCP ACROSS THE FCST AREA WEDNESDAY
WITH PRCP MOSTLY -SHRA THOUGH AGAIN MIXED -SHRASN PSBL N/MT AREAS.
MOSTLY FAIR WX FOLLOWS FOR THURSDAY AND FRIDAY THOUGH ISOLD TO
MAYBE SCT -SHRA OR -SHRASN N/MT AREAS COULD OCCUR DUE TO CYCLONIC
FLOW AND CD POOL ALOFT.
GENERALLY USED GFS40...HPC QPF AND BLEND OF MAV/MET MOS FOR
SUNDAY AND SUNDAY NGT. USED GMOS FOR REST OF THE LONG TERM
FCST...EXCEPT USED A BLEND OF GFS40 AND MEX MOS GUIDANCE FOR MAX AND
MIN TEMPS.
&&
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...VFR TONIGHT THROUGH SATURDAY NIGHT.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...CONDITIONS LOWER TO IFR IN
-RA OR MAYBE -RASN N/MT AREAS DURING THE DAY SUNDAY...CONT SUNDAY
NGT. CONDITIONS IMPROVE TO VFR...EXCEPT MVFR N/MT AREAS...ON
MONDAY. CONDITIONS LOWER TO IFR AGAIN ON WEDNESDAY IN -RA OR MAYBE
-RASN N/MT AREAS.
&&
.MARINE...
SHORT TERM...NO FLAGS FOR TONIGHT THROUGH SATURDAY NIGHT.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...WINDS PICK UP TO SCA LEVELS
FOR MONDAY AS THE SFC LOW MOVES BY TO OUR S...AND POSSIBLY CONT
MONDAY NGT AS CD AIR ENHANCES NW FLOW BEHIND THE DEPARTING LOW.
OTRW WINDS AND SEAS BELOW SCA CRITERIA.
&&
.FIRE WEATHER...
NO PROBLEMS EXPECTED THROUGH THE WEEKEND.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
835 PM EDT FRI MAR 30 2012
.SYNOPSIS...
HIGH PRESSURE WILL HOLD OVER NORTHERN NEW ENGLAND TONIGHT AND
SATURDAY AS LOW PRESSURE PASSES SOUTH OF NEW ENGLAND. LOW PRESSURE
CROSSING SOUTHERN CANADA SATURDAY NIGHT WILL DROP SOUTHEAST INTO
WESTERN NEW ENGLAND BY SUNDAY EVENING. LOW PRESSURE WILL CONTINUE
SOUTHEAST MOVING OFF THE NEW ENGLAND COAST SUNDAY NIGHT. HIGH
PRESSURE WILL BUILD IN FROM THE NORTHWEST MONDAY THROUGH TUESDAY.
LOW PRESSURE PASSING SOUTH OF NEW ENGLAND ON WEDNESDAY WILL DRAG A
WEAK COLD FRONT THROUGH THE AREA. HIGH PRESSURE WILL BUILD IN FROM
THE WEST THURSDAY THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
UPDATE...
ONLY MINOR UPDATES TO THE CURRENT GRIDDED PACKAGE THIS EVENING.
CLOUDS OVER CENTRAL NEW YORK STATE WILL CONTINUE TO PRESS EASTWARD
INTO OUR REGION TONIGHT. BY 05Z-06Z...PERHAPS A FEW FLURRIES WILL
MAKE IT THROUGH THE DRY AIR AND INTO EXTRME SRN NH. HAVE INCREASED
POPS JUST A TAD BASED ON THE LATEST HRRR MODEL...HOWEVER THEY
STILL REMAIN IN THE CHC CATEGORY OVER SRN NH.
SCAS HAVE BEEN DROPPED AS WINDS NOW BLO 25 KT.
OTHERWISE...MADE A FEW MINOR ADJUSTMENTS BASED ON CURRENT DEW
POINT AND CLOUD COVER TRENDS.
PREV DISC...
GUSTY NORTHWEST WINDS WILL QUICKLY DROP OFF THIS EVENING AS HIGH
PRESSURE BUILDS IN FROM THE WEST. ASIDE FROM VARIABLE HIGH CLOUDS
ACROSS THE CONNECTICUT VALLEY AND SOUTHERN NEW HAMPSHIRE SHOULD
SEE A MOSTLY CLEAR EVENING. SHORTWAVE DIVING SOUTHEAST THROUGH
WESTERN NEW YORK WILL THICKEN CLOUDS IN SOUTHWEST ZONES THROUGH
MIDNIGHT AND THERE COULD BE A FEW WIDELY SCATTERED SNOW SHOWERS
ACROSS SOUTHWEST NEW HAMPSHIRE AFTER MIDNIGHT. NORTH AND EAST OF
THE PORTLAND AREA SHOULD SEE A MOSTLY CLEAR NIGHT. OVERNIGHT LOWS
WILL RANGE THROUGH THE TEENS IN THE NORTH AND 20S IN THE SOUTH.
&&
.SHORT TERM /SATURDAY NIGHT/...
CLOUDS WILL PERSIST FOR MUCH OF THE DAY ACROSS SOUTHERN NEW
HAMPSHIRE AND SOUTHWEST MAINE ON SATURDAY AS LOW PRESSURE PASSES
OUT TO SEA SOUTH OF NEW ENGLAND. MAY SEE SOME RAIN OR SNOW SHOWERS
IN FAR SOUTHERN NEW HAMPSHIRE...ESPECIALLY DURING THE MORNING
HOURS BUT ONCE AGAIN ANY ACTIVITY WILL BE LIGHT AND SPOTTY.
ELSEWHERE SUNSHINE WILL BE FILTERED THROUGH VARIABLE HIGH AND MID
LEVEL CLOUDS...WHICH WILL GRADUALLY DIMINISH IN THE AFTERNOON.
LOOKING FOR HIGHS RANGING THROUGH THE 40S THROUGHOUT THE FORECAST
AREA.
CLOUDS WILL CLEAR ACROSS SOUTHERN NEW HAMPSHIRE SATURDAY NIGHT AND
THE REMAINDER OF THE FORECAST AREA WILL SEE A MOSTLY CLEAR NIGHT
WITH HIGH CLOUDS SPILLING BACK INTO THE REGION TOWARD SUNDAY
MORNING. LOOKING FOR LOWS IN THE UPPER TEENS TO UPPER 20S.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
UPR LVL TROF DROPS SE OUT OF CENTRAL CANADA IN THE NW FLOW
ALOFT... BRINGING A SFC LOW TOWARD THE FCST AREA SUNDAY. THIS
WILL SPREAD CLOUDS THEN PRCP INTO THE FCST AREA...WITH TIMING
STILL UP IN THE AIR AS MODELS CONT TO HAVE THEIR DIFFERENCES...
BOTH BETWEEN EACH MODEL AND WITH EACH RUN.
STILL SHOULD SEE SOME PRCP BEFORE THE END OF THE DAY. PRCP
CONTINUES SUNDAY NGT AS THE LOW TRACKS SE MOVING ACROSS SRN NEW
ENGLAND SUNDAY NGT AND OFF THE COAST ON MONDAY. MODELS BRING IN CD
AIR ALOFT BUT THE LOWER LEVELS AS INDICATED BY H9 TEMPS AND H10 TO
H8 THICKNESS VALUES WRM UP AND WILL LIKELY LEAD TO MOSTLY -RA
THOUGH MORE NRN AND HIGHER ELEVATION AREAS COULD SEE MIXED -RASN
OR EVEN A PERIOD OF -SN /ESPECIALLY TOWARD THE END OF THE EVENT
LATE SUNDAY NGT AS THE LOW MOVES OFFSHORE AND COLDER AIR FILTERS
IN ON NW WINDS/.
THE CD NW FLOW BEHIND THE LOW FOR MONDAY BRINGS IMPROVING WX
AFTER ANY -SHRASN ENDS. COOL DRY WX MONDAY NGT AS AN UPR LVL AND
SFC RIDGE BUILD IN. THESE SYSTEMS GIVE US FAIR WX TUESDAY. ANOTHER
UPR LVL TROF DIGS SE INTO THE REGION TUESDAY NGT. AS THE SYSTEM
INTENSIFIES AND MOVES OVERHEAD ON WEDNESDAY IT CAUSES A SFC LOW TO
DEVELOP AND PASS TO OUR S. PRPC MAY ARRIVE LATE TUESDAY NGT OVER
WRN AREAS. SHOULD SEE A CHC OF PRCP ACROSS THE FCST AREA WEDNESDAY
WITH PRCP MOSTLY -SHRA THOUGH AGAIN MIXED -SHRASN PSBL N/MT AREAS.
MOSTLY FAIR WX FOLLOWS FOR THURSDAY AND FRIDAY THOUGH ISOLD TO
MAYBE SCT -SHRA OR -SHRASN N/MT AREAS COULD OCCUR DUE TO CYCLONIC
FLOW AND CD POOL ALOFT.
GENERALLY USED GFS40...HPC QPF AND BLEND OF MAV/MET MOS FOR
SUNDAY AND SUNDAY NGT. USED GMOS FOR REST OF THE LONG TERM
FCST...EXCEPT USED A BLEND OF GFS40 AND MEX MOS GUIDANCE FOR MAX AND
MIN TEMPS.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...VFR TONIGHT THROUGH SATURDAY NIGHT.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...CONDITIONS LOWER TO IFR IN
-RA OR MAYBE -RASN N/MT AREAS DURING THE DAY SUNDAY...CONT SUNDAY
NGT. CONDITIONS IMPROVE TO VFR...EXCEPT MVFR N/MT AREAS...ON
MONDAY. CONDITIONS LOWER TO IFR AGAIN ON WEDNESDAY IN -RA OR MAYBE
-RASN N/MT AREAS.
&&
.MARINE...
SHORT TERM...NO FLAGS FOR TONIGHT THROUGH SATURDAY NIGHT.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...WINDS PICK UP TO SCA LEVELS
FOR MONDAY S THE SFC LOW MOVES BY TO OUR S...AND POSSIBLY CONT
MONDAY NGT AS CD AIR ENHANCES NW FLOW BEHIND THE DEPARTING LOW.
OTRW WINDS AND SEAS BELOW SCA CRITERIA.
&&
.FIRE WEATHER...
NO PROBLEMS EXPECTED THROUGH THE WEEKEND.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
812 PM EDT FRI MAR 30 2012
.SYNOPSIS...
HIGH PRESSURE WILL HOLD OVER NORTHERN NEW ENGLAND TONIGHT AND
SATURDAY AS LOW PRESSURE PASSES SOUTH OF NEW ENGLAND. LOW PRESSURE
CROSSING SOUTHERN CANADA SATURDAY NIGHT WILL DROP SOUTHEAST INTO
WESTERN NEW ENGLAND BY SUNDAY EVENING. LOW PRESSURE WILL CONTINUE
SOUTHEAST MOVING OFF THE NEW ENGLAND COAST SUNDAY NIGHT. HIGH
PRESSURE WILL BUILD IN FROM THE NORTHWEST MONDAY THROUGH TUESDAY.
LOW PRESSURE PASSING SOUTH OF NEW ENGLAND ON WEDNESDAY WILL DRAG A
WEAK COLD FRONT THROUGH THE AREA. HIGH PRESSURE WILL BUILD IN FROM
THE WEST THURSDAY THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
UPDATE...
ONLY MINOR UPDATES TO THE CURRENT GRIDDED PACKAGE THIS EVENING.
CLOUDS OVER CENTRAL NEW YORK STATE WILL CONTINUE TO PRESS EASTWARD
INTO OUR REGION TONIGHT. BY 05Z-06Z...PERHAPS A FEW FLURRIES WILL
MAKE IT THROUGH THE DRY AIR AND INTO EXTRME SRN NH. HAVE INCREASED
POPS JUST A TAD BASED ON THE LATEST HRRR MODEL...HOWEVER THEY
STILL REMAIN IN THE CHC CATEGORY OVER SRN NH.
SCAS HAVE BEEN DROPPED AS WINDS NOW BLO 25 KT.
OTHERWISE...MADE A FEW MINOR ADJUSTMENTS BASED ON CURRENT DEW
POINT AND CLOUD COVER TRENDS.
PREV DISC...
GUSTY NORTHWEST WINDS WILL QUICKLY DROP OFF THIS EVENING AS HIGH
PRESSURE BUILDS IN FROM THE WEST. ASIDE FROM VARIABLE HIGH CLOUDS
ACROSS THE CONNECTICUT VALLEY AND SOUTHERN NEW HAMPSHIRE SHOULD
SEE A MOSTLY CLEAR EVENING. SHORTWAVE DIVING SOUTHEAST THROUGH
WESTERN NEW YORK WILL THICKEN CLOUDS IN SOUTHWEST ZONES THROUGH
MIDNIGHT AND THERE COULD BE A FEW WIDELY SCATTERED SNOW SHOWERS
ACROSS SOUTHWEST NEW HAMPSHIRE AFTER MIDNIGHT. NORTH AND EAST OF
THE PORTLAND AREA SHOULD SEE A MOSTLY CLEAR NIGHT. OVERNIGHT LOWS
WILL RANGE THROUGH THE TEENS IN THE NORTH AND 20S IN THE SOUTH.
&&
.SHORT TERM /SATURDAY NIGHT/...
CLOUDS WILL PERSIST FOR MUCH OF THE DAY ACROSS SOUTHERN NEW
HAMPSHIRE AND SOUTHWEST MAINE ON SATURDAY AS LOW PRESSURE PASSES
OUT TO SEA SOUTH OF NEW ENGLAND. MAY SEE SOME RAIN OR SNOW SHOWERS
IN FAR SOUTHERN NEW HAMPSHIRE...ESPECIALLY DURING THE MORNING
HOURS BUT ONCE AGAIN ANY ACTIVITY WILL BE LIGHT AND SPOTTY.
ELSEWHERE SUNSHINE WILL BE FILTERED THROUGH VARIABLE HIGH AND MID
LEVEL CLOUDS...WHICH WILL GRADUALLY DIMINISH IN THE AFTERNOON.
LOOKING FOR HIGHS RANGING THROUGH THE 40S THROUGHOUT THE FORECAST
AREA.
CLOUDS WILL CLEAR ACROSS SOUTHERN NEW HAMPSHIRE SATURDAY NIGHT AND
THE REMAINDER OF THE FORECAST AREA WILL SEE A MOSTLY CLEAR NIGHT
WITH HIGH CLOUDS SPILLING BACK INTO THE REGION TOWARD SUNDAY
MORNING. LOOKING FOR LOWS IN THE UPPER TEENS TO UPPER 20S.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
UPR LVL TROF DROPS SE OUT OF CENTRAL CANADA IN THE NW FLOW
ALOFT... BRINGING A SFC LOW TOWARD THE FCST AREA SUNDAY. THIS
WILL SPREAD CLOUDS THEN PRCP INTO THE FCST AREA...WITH TIMING
STILL UP IN THE AIR AS MODELS CONT TO HAVE THEIR DIFFERENCES...
BOTH BETWEEN EACH MODEL AND WITH EACH RUN.
STILL SHOULD SEE SOME PRCP BEFORE THE END OF THE DAY. PRCP
CONTINUES SUNDAY NGT AS THE LOW TRACKS SE MOVING ACROSS SRN NEW
ENGLAND SUNDAY NGT AND OFF THE COAST ON MONDAY. MODELS BRING IN CD
AIR ALOFT BUT THE LOWER LEVELS AS INDICATED BY H9 TEMPS AND H10 TO
H8 THICKNESS VALUES WRM UP AND WILL LIKELY LEAD TO MOSTLY -RA
THOUGH MORE NRN AND HIGHER ELEVATION AREAS COULD SEE MIXED -RASN
OR EVEN A PERIOD OF -SN /ESPECIALLY TOWARD THE END OF THE EVENT
LATE SUNDAY NGT AS THE LOW MOVES OFFSHORE AND COLDER AIR FILTERS
IN ON NW WINDS/.
THE CD NW FLOW BEHIND THE LOW FOR MONDAY BRINGS IMPROVING WX
AFTER ANY -SHRASN ENDS. COOL DRY WX MONDAY NGT AS AN UPR LVL AND
SFC RIDGE BUILD IN. THESE SYSTEMS GIVE US FAIR WX TUESDAY. ANOTHER
UPR LVL TROF DIGS SE INTO THE REGION TUESDAY NGT. AS THE SYSTEM
INTENSIFIES AND MOVES OVERHEAD ON WEDNESDAY IT CAUSES A SFC LOW TO
DEVELOP AND PASS TO OUR S. PRPC MAY ARRIVE LATE TUESDAY NGT OVER
WRN AREAS. SHOULD SEE A CHC OF PRCP ACROSS THE FCST AREA WEDNESDAY
WITH PRCP MOSTLY -SHRA THOUGH AGAIN MIXED -SHRASN PSBL N/MT AREAS.
MOSTLY FAIR WX FOLLOWS FOR THURSDAY AND FRIDAY THOUGH ISOLD TO
MAYBE SCT -SHRA OR -SHRASN N/MT AREAS COULD OCCUR DUE TO CYCLONIC
FLOW AND CD POOL ALOFT.
GENERALLY USED GFS40...HPC QPF AND BLEND OF MAV/MET MOS FOR
SUNDAY AND SUNDAY NGT. USED GMOS FOR REST OF THE LONG TERM
FCST...EXCEPT USED A BLEND OF GFS40 AND MEX MOS GUIDANCE FOR MAX AND
MIN TEMPS.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...VFR TONIGHT THROUGH SATURDAY NIGHT.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...CONDITIONS LOWER TO IFR IN
-RA OR MAYBE -RASN N/MT AREAS DURING THE DAY SUNDAY...CONT SUNDAY
NGT. CONDITIONS IMPROVE TO VFR...EXCEPT MVFR N/MT AREAS...ON
MONDAY. CONDITIONS LOWER TO IFR AGAIN ON WEDNESDAY IN -RA OR MAYBE
-RASN N/MT AREAS.
&&
.MARINE...
SHORT TERM...NO FLAGS FOR TONIGHT THROUGH SATURDAY NIGHT.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...WINDS PICK UP TO SCA LEVELS
FOR MONDAY S THE SFC LOW MOVES BY TO OUR S...AND POSSIBLY CONT
MONDAY NGT AS CD AIR ENHANCES NW FLOW BEHIND THE DEPARTING LOW.
OTRW WINDS AND SEAS BELOW SCA CRITERIA.
&&
.FIRE WEATHER...
NO PROBLEMS EXPECTED THROUGH THE WEEKEND.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
818 PM EDT FRI MAR 30 2012
.SYNOPSIS...
LOW PRESSURE MOVES EAST FROM THE OHIO VALLEY TONIGHT AND ACROSS
THE AREA ON SATURDAY. THIS WILL PUSH A COLD FRONT ACROSS THE
REGION SATURDAY AFTERNOON. HIGH PRESSURE WILL BE OVER THE AREA ON
SUNDAY. A SECOND COLD FRONT WILL MOVE THROUGH THE AREA FROM THE
NORTH ON MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
TRICKY FORECAST TONIGHT AS SEVERAL DISTURBANCES IMPACT THE AREA.
ONCE DISTURBANCE HANDLED WELL BY THE HRRR IS CAUSING A FEW SHOWERS
ACROSS THE DELMARVA AND NORTHERN AREAS LATE THIS AFTERNOON AND
EVENING. THIS IS ALONG A DEVELOPING UPPER LEVEL WARM FRONT WHICH
WILL QUICKLY MOVE NORTH OF THE AREA. THE NEXT SYSTEM IS AN UPPER
DISTURBANCE OVER THE SOUTHEAST WHICH WILL MOVE ACROSS TO THE SOUTH
OF THE AREA TONIGHT AND EARLY ON SATURDAY. THIS IS CAUSING AN AREA
OF CONVECTION TO DEVELOP TO THE SOUTH OF THE AREA. HOW FAR NORTH
THIS CONVECTION DEVELOPS IS QUITE VARIED ON THE MODEL FORECAST.
THE VAST MAJORITY KEEP THE SOUTHERN CONVECTION SOUTH OF THE
VIRGINIA NORTH CAROLINA LINE. HOWEVER COULD SEE IT MOVE OVER
EXTREME SOUTHEASTERN VIRGINIA AROUND SUNRISE. THE OTHER SYSTEM IN
THE OHIO VALLY HAS A SURFACE LOW PRESSURE SYSTEM ASSOCIATED WITH
IT OVER OHIO. THIS LOW WILL MOVE EAST AND THEN SOUTHEAST ACROSS
THE AREA ON SATURDAY. THIS WILL BRING SOME SHOWERS TO THE
NORTHWEST SECTIONS LATER TONIGHT. ON SATURDAY SEVERAL MODELS ARE
SHOWING CONVECTION DEVELOPING AHEAD OF THIS SYSTEM DURING THE
AFTERNOON MAINLY SOUTHEAST OF THE RICHMOND AREA. LOOKING AT BUFKIT
THE MAIN QUESTION BECOMES HOW FAST DRIER AIR CAN WORK IN AND CUT
OFF THE CONVECTIVE POTENTIAL. ALL MODELS DO HAVE SOME FORCING WITH
THE SYSTEM. FOR NOW WENT WITH CHANCE POPS. TEMPERATURES TONIGHT
WILL ONLY DROP INTO THE 50S MOST AREAS ON DEVELOPING SOUTHWEST
WINDS. ON SATURDAY THE LIMITING FACTOR ON TEMPERATURES WILL BE THE
CLOUDS BUT STILL THINK MANY INLAND AREAS WILL BE IN THE 70S.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
BY SATURDAY NIGHT AND ON SUNDAY THE AREA IS BETWEEN SYSTEMS WITH
PLENTY OF DRY AIR SO SKIES WILL CLEAR. ON SUNDAY WILL HAVE SOME
COLD AIR ADVECTION ALOFT BUT TEMPERATURES STILL ABOVE NORMAL WITH
DOWNSLOPE NORTHWEST FLOW AND PLENTY OF SUNSHINE. BY SUNDAY NIGHT
THE NEXT FRONT APPROACHES FROM THE NORTHWEST. AGAIN THE MODELS
HAVE DIFFERENCES ON THE AMOUNT OF PRECIPITATION ASSOCIATED WITH
THIS FRONT. WILL LEAN TOWARD DRIER MODELS SUCH AS CANADIAN AND
GFS. STILL HAVE SLIGHT CHANCE POPS LATE SUNDAY NIGHT AND MONDAY
WITH THE HIGHEST POPS TO THE EASTERN SECTIONS. THE NAM DOES NOT
PUSH THE FRONT THROUGH BUT WILL BASE TEMPERATURES ON HAVING THE
FRONT TO THE SOUTH. AGAIN STILL ABOVE NORMAL MOST INLAND AREAS BUT
WITH SOME EAST COMPONENT TO THE WINDS AREAS OVER THE DELMARVA AND
ALONG THE COAST WILL REMAIN IN THE 60S FOR HIGHS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE MID AND UPPER LEVEL LONGWAVE PATTERN CONTINUES TO APPEAR MORE
AMPLIFIED AND NORTHERN STREAM DOMINATED DURING THE EXTENDED PERIOD
FROM MONDAY NIGHT THROUGH FRIDAY. GIVEN THIS...TEMPERATURES WERE
LOWERED A FEW DEGREES FOR TUESDAY AS A TROUGH OVER MARITIME CANADA
DRIVES NW FLOW FROM THE MID ATLANTIC TO NEW ENGLAND...BUT THE IDEA
OF A WARMING TREND OVER MONDAY REMAINS REASONABLE AS THICKNESS VALUE
ARE EXPECTED TO RISE. THE AMPLIFICATION IN THE PATTERN APPEARS TO
DELAY THE NEXT COLD FRONT TO TUESDAY NIGHT AND WEDNESDAY. MOISTURE
APPEARS RATHER LIMITED AS NORTHERN STREAM ENERGY KEEPS DEEPER
MOISTURE SOUTH OF THE LOCAL AREA. MORE SEASONAL TEMPERATURES ARE
EXPECTED BY THE END OF THE WEEK AS CANADIAN HIGH PRESSURE BUILDS IN
BEHIND THE AFOREMENTIONED COLD FRONT.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
LOW CLOUDS AND -RA WILL DEVELOP IN ADVANCE OF A COLD FRONT SAT
MORN. TIMING PRECIP IS A BIT DIFFICULT BUT THINK RAIN WILL LIKELY
AFFECT THE WESTERN PORTIONS OF THE AREA BY MID MORNING AND SPREAD
EAST BY THE AFTN...WITH TSTMS POSSIBLE DURING THE AFTN HOURS. THE
FRONT CLEARS THE REGION SAT EVENING.
CONDITIONS MAY DETERIORATE SUN MORNING WITH THE POSSIBILITY OF
LOW CLOUDS DEVELOPING WITH A NNE WIND. HIGH PRES BUILDS INTO THE
REGION SUN AFTN THROUGH MON WITH VFR CONDS EXPECTED.
&&
.MARINE...
SURFACE HIGH PRESSURE MOVES OFF THE COAST TONIGHT AS LOW PRESSURE
AND AN ASSOCIATED COLD FRONT APPROACH FROM THE WEST. THIS COLD FRONT
CROSSES THE MID ATLANTIC COAST N-S DURING THE LATE AFTERNOON AND
EARLY EVENING SATURDAY. A MODEST NORTHERLY SURGE IS EXPECTED IN THE
WAKE OF THE COLD FRONT. WIND SPEEDS SHOULD BE AROUND 20-25KT AND
THIS SHOULD ALSO PUSH SEAS TO AROUND 5FT. GIVEN THIS...SCA FLAGS
HAVE BEEN RAISED FOR ALL AREAS BEGINNING N-S SATURDAY AFTERNOON AND
EVENING...AND THEN ENDING N-S EARLY SUNDAY MORNING. HIGH PRESSURE
BRIEFLY BUILDS IN SUNDAY BEFORE MOVING OFF THE COAST AS ANOTHER LOW
PRESSURE SYSTEM MOVES OFF THE NEW ENGLAND COAST SUNDAY NIGHT AND
SUBSEQUENTLY DRAGS A COLD FRONT ACROSS THE MID ATLANTIC COAST. A
NORTHERLY SURGE WILL FOLLOW MONDAY MORNING...BUT THIS APPEARS
SUB-SCA AT THIS TIME. HIGH PRESSURE THEN PREVAILS THROUGH TUESDAY
BEFORE ANOTHER LOW PRESSURE SYSTEM ARRIVES MIDWEEK.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM SATURDAY TO 4 AM EDT SUNDAY FOR
ANZ632-634.
SMALL CRAFT ADVISORY FROM 7 PM SATURDAY TO 7 AM EDT SUNDAY FOR
ANZ633.
SMALL CRAFT ADVISORY FROM 4 PM SATURDAY TO 4 AM EDT SUNDAY FOR
ANZ630-631.
SMALL CRAFT ADVISORY FROM 4 PM SATURDAY TO 7 AM EDT SUNDAY FOR
ANZ650-652-654.
SMALL CRAFT ADVISORY FROM 7 PM SATURDAY TO 10 AM EDT SUNDAY
FOR ANZ656-658.
&&
$$
SYNOPSIS...JAB
NEAR TERM...JAB
SHORT TERM...JAB
LONG TERM...AJZ
AVIATION...DAP
MARINE...AJZ
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
410 PM EDT THU MAR 29 2012
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD IN OVERNIGHT, ALLOWING FOR A
FREEZE ACROSS MANY LOCATIONS. THE CHANCE OF SHOWERS AND
THUNDERSTORMS WILL INCREASE FRIDAY AS LOW PRESSURE CROSSES THE
REGION. WEEKEND WEATHER WILL FEATURE ONLY LOW PRECIPITATION
CHANCES AND MODERATING TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A BROAD RIDGE ACROSS
THE UPPER MIDWEST WITH THE UPPER OHIO VALLEY IN A NORTHWESTERLY
FLOW AHEAD OF THIS FEATURE. AT THE SURFACE, A HIGH CENTERED
ACROSS ONTARIO EXTENDS SOUTHWARD INTO THE GREAT LAKES. A COLD
NORTHWESTERLY FLOW IN THE LOWER LEVELS CONTINUES TO ALLOW FOR
STRATOCUMULUS TO FILTER ACROSS AREAS NORTH OF THE PITTSBURGH
METRO. OTHERWISE, CLOUD DECK IS ERODING AND SKIES ARE CLEARING
FROM THE SOUTH.
TONIGHT...HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE GREAT
LAKES, WITH A LOBE OF HIGHER PRESSURE CENTERED ACROSS CENTRAL PA BY
DAWN ON FRIDAY. WITH SKIES CLEARING AND LIGHT WINDS, RADIATIONAL
COOLING WILL ALLOW TEMPS TO DROP BELOW FREEZING PRIMARILY
NORTHEAST OF PITTSBURGH. FURTHER SOUTHWESTWARD, TDS IN THE MID 30S
AND UPPER LEVEL CLOUDS MOVING IN FROM THE WEST WILL BE LIMITING
FACTORS AND KEEP TEMPS ABOVE FREEZING. THUS, NO CHANGES TO THE FREEZE
WARNING OVERNIGHT.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
A SURFACE LOW ALONG WITH A WEAK SHORT WAVE WILL TRAVERSE ACROSS THE
OHIO VALLEY THROUGHOUT THE DAY ON FRIDAY. GFS/ECMWF SOLUTIONS
SUPPORT CHANCE POPS BEGINNING BEFORE NOON ON FRIDAY, AS
OVERRUNNING OCCURS AHEAD A WARM FRONTAL BOUNDARY APPROACHING FROM
THE SOUTHWEST. POPS INCREASE TO CATEGORICAL WITH THE SURFACE LOW
PROGGED TO REACH WESTERN PA BY 06Z ON SATURDAY. A FASTER AND MORE
NORTHERN TRACK WOULD INCREASE THE CHANCES OF SEVERE WEATHER ACROSS
THE AREA TOMORROW EVENING WITH THE NAM 4KM SUPPORTING CONVECTION
BECOMING LINEAR IN THE WARM SECTOR AHEAD OF THE COLD FRONT THAT
WILL SWING IN BEHIND THE LOW. FOR NOW, SEVERE THREAT IS JUST
MENTIONED IN THE HWO FOR EAST-CENTRAL OHIO WITH ANY LINEAR
CONVECTION THERE ANTICIPATED TO WEAKEN WITH THE LOSS OF HEATING AS
IT PUSHES ACROSS THE REMAINDER OF THE AREA.
CHALLENGING TEMPERATURE FORECAST FRIDAY AND FRIDAY NIGHT AS THE
FRONTAL BOUNDARY APPROACHES FROM THE SOUTHWEST AND THEN COLD AIR
ADVECTION BEGINS LATE FRIDAY NIGHT AS THE LOW PUSHES EAST OF THE AREA.
HIGHS 5 TO 10 DEGREES ABOVE SEASONAL NORMALS WILL BE REACHED IN THE
EVENING IN MANY LOCATIONS AS THE WARM SECTOR PUSHES INTO THE AREA.
FRIDAY NIGHT LOWS WILL RANGE FROM THE UPPER 40S ACROSS NORTH-
CENTRAL WV TO THE UPPER 30S NORTH OF PITTSBURGH.
SATURDAY AND SUNDAY...THE SURFACE LOW WILL PUSH OFF THE MID-
ATLANTIC COAST ON SATURDAY. WITH A NORTHWESTERLY MID-LEVEL FLOW AND COLD
AIR ADVECTION IN THE WAKE OF THE COLD FRONT. A FEW LINGERING
SHOWERS WILL CONTINUE EARLY ON INTO SATURDAY. MODEL THICKNESSES
WILL DECREASE TO SLIGHTLY TOO WARM FOR SNOW, SO PRECIP IS FORECAST
TO REMAIN ALL RAIN ACROSS THE I-80 CORRIDOR AND EASTERN RIDGES FOR
NOW. HIGH PRESSURE WILL THEN BRIEFLY BUILD IN WITH A DRY
FORECAST SATURDAY INTO EARLY SUNDAY. THE NEXT FRONTAL BOUNDARY
WILL LIFT INTO THE AREA LATE ON SUNDAY AND RETURN THE CHANCE OF
SHOWERS. TEMPERATURES WILL BE NEAR NORMAL VALUES ON SATURDAY AND
WARM TO AROUND 15 DEGREES ABOVE NORMAL BY SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE EXTENDED PERIOD BEGINS WITH GOOD AGREEMENT ON THE ADVANCEMENT
OF AN UPPER RIDGE TOWARD THE AREA FOR THE START OF NEXT WEEK. AS
THIS OCCURS...A GOOD BIT OF WARMING SHOULD OCCUR ACROSS THE CWA AS
850 MB TEMPERATURES ON ALL GUIDANCE WARM INTO THE 10-14C RANGE BY
EARLY TUESDAY. TIMING DIFFERENCES AMONGST THE MODELS BECOME VERY
APPARENT BY THE TIME THE RIDGE IS TRAVERSING THE AREA ON MONDAY
WITH REGARD TO THE NEXT ORGANIZED PIECE OF ENERGY THAT SHOULD
AFFECT THE AREA THAT WILL BE LIKELY MOVING INTO THE SOUTHERN
PLAINS OR MID-MISSISSIPPI VALLEY BY THAT JUNCTURE. THE GFS/DGEX
COMBO IS FAR DEEPER AND ALSO CLOSED OFF WITH THE MID-LEVEL ENERGY
WITH THIS SYSTEM BY MONDAY...WHILE THE ECMWF PREFER A MORE OPEN
WAVE AND FASTER SOLUTION. THE RAMIFICATIONS OF THESE DIFFERENCES
BECOME APPARENT IN OUR FORECAST BY THE TUESDAY TO WEDNESDAY TIME
FRAME AS THE GFS LAGS THE ECMWF IN BRINGING PRECIPITATION INTO THE
AREA. ADDITIONALLY...THE GFS BECAUSE OF ITS MORE AMPLIFIED
SCENARIO ALSO BRINGS SIGNIFICANTLY WARMER AIR INTO THE CWA FOR A
LONGER DURATION AHEAD OF THE SYSTEM. WHILE THERE REALLY IS LITTLE
TO GO ON IN TERMS OF REAL DATA TO SELECT A MODEL PREFERENCE...THE
GEFS MEMBERS DO LEAN MORE TOWARD AN OPEN WAVE SOLUTION...WHICH
TENDS TO FAVOR THE ECMWF SOLUTION OVER THE OPERATIONAL GFS. AS A
RESULT...THE FORECAST LEANS A BIT TOWARD THE FASTER ECMWF
SOLUTION. HOWEVER...IT DOES NOT NEGLECT THE CLOSED/SLOWER GFS
SOLUTION...AS THE GFS HAS BEEN DEPICTING THE CLOSED SOLUTION FOR
AT LEAST A COUPLE OF CYCLES NOW.
WITH THE PASSAGE OF THE MAIN SYSTEM BY TUESDAY NIGHT...GOOD
AGREEMENT AGAIN EXISTS IN THE ESTABLISHMENT OF DEEP LAYER
NORTHWESTERLY FLOW OVER THE AREA. AS THIS OCCURS...SIGNIFICANTLY
COLDER AIR IS SET TO ARRIVE IN THE CWA BY NEXT FRIDAY NIGHT. JUST
AFTER THE END OF THE VALID PERIOD OF THE FORECAST AND ESPECIALLY
INTO NEXT WEEKEND...EARLY INDICATIONS ARE THAT 850 MB TEMPERATURES
COULD FALL OFF INTO THE -4 TO -8C RANGE OVER A GOOD CHUNK OF THE
FORECAST AREA. IF THIS WERE TO OCCUR IN THE AFOREMENTIONED
UNSTABLE NORTHWESTERLY FLOW...A TRANSITION TO A PERIOD OF SNOW
SHOWERS WOULD BE LIKELY...WITH SIGNIFICANTLY COLDER TEMPERATURES
THAN THOSE TO WHICH WE HAVE BECOME ACCUSTOMED. STAY TUNED. FRIES
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
CUMULUS HAS BEEN DEVELOPING ON THE PERIPHERY OF THE STRATUS FIELD
THAT HAS BEEN STUBBORNLY ADVANCING FROM THE NORTHWEST ACROSS THE
TAF SITES ALL MORNING. SOME BETTER MIXING IS EVIDENT IN THE
STRATUS LAYER...AS BREAKS ARE EVEN BECOMING APPARENT AROUND KPIT
AS OF 18Z. AS THE AFTERNOON CONTINUES...BREAKS IN THE STRATUS
SHOULD BECOME MORE COMMON...WHILE CUMULUS WILL CONTINUE TO DEVELOP
AROUND IT. FLOW IN THE MIXED LAYER SHOULD GRADUALLY WEAKEN AND
TURN MORE WESTERLY BY EARLY EVENING...WHICH SHOULD HELP TO BRING
SOME DRIER AIR OVER THE AREA...THAT ALONG WITH THE LOSS OF
AFTERNOON HEATING SHOULD HELP TO DISSIPATE BOTH THE STRATUS AND
CUMULUS OVER THE AREA. AS THIS OCCURS...WINDS SHOULD
DECOUPLE...AND WE WILL LIKELY BE LEFT WITH LIGHT WINDS AND
CLEARING SKIES FOR THE OVERNIGHT AND EARLY HALF OF FRIDAY.
OUTLOOK...FRIDAY THROUGH TUESDAY...
RESTRICTIONS ARE POSSIBLE FRIDAY AFTERNOON INTO SATURDAY DUE TO
SHOWERS AND LOW CLOUDS ASSOCIATED WITH PASSING EASTBOUND LOW
PRESSURE SYSTEM. EXPECT MAINLY VFR SUNDAY AND MONDAY BEFORE
ANOTHER SYSTEM ADVANCES FOR TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR MDZ001.
OH...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR OHZ041.
PA...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR PAZ007>009-
013>016-020>023-029-073>076.
WV...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1010 AM EDT THU MAR 29 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD TODAY AND PROVIDE DRY...BUT COOLER
WEATHER. RAIN CHANCES ARE SET TO INCREASE ON FRIDAY AS LOW
PRESSURE CROSSES THE REGION. WEEKEND WEATHER WILL FEATURE
ONLY LOW PRECIPITATION CHANCES AND MODERATING TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
A MID-MORNING UPDATE HAS BEEN ISSUED IN ORDER TO ACCOUNT FOR THE
LATEST TRENDS IN SKY COVERAGE.
A COLD NORTHWESTERLY FLOW WILL CONTINUE TO ALLOW FOR STRATOCUMULUS
TO FILTER ACROSS AREAS MOSTLY EAST OF I-77 THROUGH THE EARLY
AFTERNOON. MOISTURE WILL BEGIN TO PULL EAST OF THE AREA AND ERODE
WITH BREAKS EARLY THIS AFTERNOON AND CLEARING FROM THE SOUTHWEST
BY LATE AFTERNOON. CLOUD COVERAGE WILL KEEP TEMPS DOWN TODAY.
HIGHS TODAY WILL RANGE FROM THE MID 40S ALONG THE I-80 CORRIDOR
AND EASTERN RIDGES TO THE UPPER 50S WITH MORE SUNSHINE IN PORTIONS
OF EASTERN OHIO.
WITH DIMINISHED WIND AND CLOUD COVER TONIGHT...RADIATIONAL COOLING
WILL RAPIDLY COMMENCE WITH TEMPERATURES FALLING INTO THE 30S
ACROSS THE ENTIRE AREA BY FRIDAY MORNING...AND UPPER 20S ARE
PROJECTED OVER THE RIDGE ZONES AND OVER COUNTIES NORTH OF
PITTSBURGH.
WARM...MOIST ADVECTION/MID LEVEL CLOUDINESS IN ADVANCE OF MIDWRN
LOW PRESSURE ARE CURRENTLY PROJECTED TO ARRIVE AT AROUND
DAYBREAK...TOO LATE TO PRECLUDE AREAS OF FROST FOR ALL ZONES.
FREEZE WARNING WAS ISSUED FOR THE NORTHEASTERN HALF OF THE COUNTY
WARNING AREA...WHERE SURFACE RIDGE AXIS WILL CROSS AND WHERE
DRIER AIR WILL SETTLE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AFOREMENTIONED MIDWRN LOW PRES LOOKS TO APPROACH THE AREA ON
FRIDAY...WITH PASSAGE PROJECTED FOR FRIDAY NIGHT...AND SYSTEM EXIT
ON SATURDAY. HAVE GENERALLY PERSISTED WITH PREVIOUS
FORECAST...BUT WITH ADJUSTMENTS TO TIMING AS PER LATEST
DETERMINISTIC MODEL TRENDS. HAVE ALSO INCLUDED A THUNDER MENTION
FOR THE SOUTHERN ZONES ON FRIDAY AFTERNOON GIVEN THE INSTABILITY
PROGNOSIS AND LOW PRESSURE TRACK.
BY SUNDAY...TEMPERATURE MODERATION IS FORECAST TO BE UNDERWAY AS
GREAT LAKES RIDGE AMPLIFIES...BUT SHORTWAVE IN NORTHWEST FLOW MAY
SPAWN SOME SHOWERS GIVEN LATEST MODEL SOLUTIONS. HAVE DECIDED TO
ENTER A SLIGHT CHANCE FOR NOW.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE NEXT LOW WILL TRACK FROM THE UPPER MS VALLEY INTO SOUTHERN
ONTARIO AND WILL PUSH A COLD FRONT THROUGH THE OHIO VALLEY
TUESDAY. SCATTERED SHOWERS SHOULD ACCOMPANY THIS SYSTEM TUESDAY
INTO EARLY WEDNESDAY.
TEMPERATURES ARE FORECAST TO RANGE BETWEEN 10 AND 15 DEGREES ABOVE
NORMAL THROUGH TUESDAY...WITH A RETURN TO NEAR NORMAL READINGS BY
WEDNESDAY.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
RECENT SURFACE AND SATELLITE DATA, COUPLED WITH HRRR AND NAM MODEL
OUTPUT, SHOW COLD POOL MVFR STRATOCUMULUS EXPANDING SOUTHWARD ACROSS
THE UPPER OHIO VALLEY THROUGH 12Z. DAYTIME HEATING WILL INDUCE
VERTICAL MIXING TO CAUSE CLOUD CEILINGS TO LIFT THIS MORNING AND
THEN DISSIPATE, SOUTH TO NORTH, THIS AFTERNOON. EXPECT VFR WITH
MOSTLY CLEAR SKIES TONIGHT.
SURFACE WINDS WILL BE NORTHWEST 10-15 KTS TODAY AND BECOME LIGHT
TONIGHT.
OUTLOOK...FRIDAY THROUGH MONDAY...
RESTRICTIONS ARE POSSIBLE FRIDAY AFTERNOON INTO SATURDAY DUE TO
SHOWERS AND LOW CLOUDS ASSOCIATED WITH PASSING EASTBOUND LOW
PRESSURE SYSTEM. EXPECT MAINLY VFR SUNDAY AND MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR MDZ001.
OH...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR OHZ041.
PA...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR PAZ007>009-
013>016-020>023-029-073>076.
WV...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
639 AM EDT THU MAR 29 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD TODAY AND PROVIDE DRY...BUT COOLER
WEATHER. RAIN CHANCES ARE SET TO INCREASE ON FRIDAY AS LOW
PRESSURE CROSSES THE REGION. WEEKEND WEATHER WILL FEATURE
ONLY LOW PRECIPITATION CHANCES AND MODERATING TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
630AM UPDATE. ONLY MINOR CHANGES TO REFLECT CURRENT CONDITIONS.
BRISK WINDS DURING THE DAY AND STRATOCU WILL ERODE BY LATE DAY AS
SURFACE RIDGE AXIS SLIDES OVER THE AREA.
TONIGHT WITH DIMINISHED WIND AND CLOUD COVER...RADIATIONAL
COOLING WILL RAPIDLY COMMENCE WITH TEMPERATURES FALLING INTO THE
30S ACROSS THE ENTIRE AREA BY FRIDAY MORNING...AND UPPER 20S ARE
PROJECTED OVER THE RIDGE ZONES AND OVER COUNTIES NORTH OF
PITTSBURGH.
WARM...MOIST ADVECTION/MID LEVEL CLOUDINESS IN ADVANCE OF MIDWRN
LOW PRESSURE ARE CURRENTLY PROJECTED TO ARRIVE AT AROUND
DAYBREAK...TOO LATE TO PRECLUDE AREAS OF FROST FOR ALL ZONES.
FREEZE WARNING WAS ISSUED FOR THE NORTHEASTERN HALF OF THE COUNTY
WARNING AREA...WHERE SURFACE RIDGE AXIS WILL CROSS AND WHERE
DRIER AIR WILL SETTLE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AFOREMENTIONED MIDWRN LOW PRES LOOKS TO APPROACH THE AREA ON
FRIDAY...WITH PASSAGE PROJECTED FOR FRIDAY NIGHT...AND SYSTEM EXIT
ON SATURDAY. HAVE GENERALLY PERSISTED WITH PREVIOUS
FORECAST...BUT WITH ADJUSTMENTS TO TIMING AS PER LATEST
DETERMINISTIC MODEL TRENDS. HAVE ALSO INCLUDED A THUNDER MENTION
FOR THE SOUTHERN ZONES ON FRIDAY AFTERNOON GIVEN THE INSTABILITY
PROGNOSIS AND LOW PRESSURE TRACK.
BY SUNDAY...TEMPERATURE MODERATION IS FORECAST TO BE UNDERWAY AS
GREAT LAKES RIDGE AMPLIFIES...BUT SHORTWAVE IN NORTHWEST FLOW MAY
SPAWN SOME SHOWERS GIVEN LATEST MODEL SOLUTIONS. HAVE DECIDED TO
ENTER A SLIGHT CHANCE FOR NOW.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE NEXT LOW WILL TRACK FROM THE UPPER MS VALLEY INTO SOUTHERN
ONTARIO AND WILL PUSH A COLD FRONT THROUGH THE OHIO VALLEY
TUESDAY. SCATTERED SHOWERS SHOULD ACCOMPANY THIS SYSTEM TUESDAY
INTO EARLY WEDNESDAY.
TEMPERATURES ARE FORECAST TO RANGE BETWEEN 10 AND 15 DEGREES ABOVE
NORMAL THROUGH TUESDAY...WITH A RETURN TO NEAR NORMAL READINGS BY
WEDNESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
RECENT SURFACE AND SATELLITE DATA, COUPLED WITH HRRR AND NAM MODEL
OUTPUT, SHOW COLD POOL MVFR STRATOCUMULUS EXPANDING SOUTHWARD ACROSS
THE UPPER OHIO VALLEY THROUGH 12Z. DAYTIME HEATING WILL INDUCE
VERTICAL MIXING TO CAUSE CLOUD CEILINGS TO LIFT THIS MORNING AND
THEN DISSIPATE, SOUTH TO NORTH, THIS AFTERNOON. EXPECT VFR WITH
MOSTLY CLEAR SKIES TONIGHT.
SURFACE WINDS WILL BE NORTHWEST 10-15 KTS TODAY AND BECOME LIGHT
TONIGHT.
OUTLOOK...FRIDAY THROUGH MONDAY...
RESTRICTIONS ARE POSSIBLE FRIDAY AFTERNOON INTO SATURDAY DUE TO
SHOWERS AND LOW CLOUDS ASSOCIATED WITH PASSING EASTBOUND LOW
PRESSURE SYSTEM. EXPECT MAINLY VFR SUNDAY AND MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR MDZ001.
OH...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR OHZ041.
PA...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR PAZ007>009-
013>016-020>023-029-073>076.
WV...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
406 AM EDT THU MAR 29 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD TODAY AND PROVIDE DRY...BUT COOLER
WEATHER. RAIN CHANCES ARE SET TO INCREASE ON FRIDAY AS LOW
PRESSURE CROSSES THE REGION. WEEKEND WEATHER WILL FEATURE
ONLY LOW PRECIPITATION CHANCES AND MODERATING TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
STRATOCUMULUS BLANKET WILL CONTINUE TO SLIDE SOUTHWARD ACROSS THE
UPPER OHIO REGION AS COLD ADVECTION IS UNDERWAY FOLLOWING PASSAGE
OF YESTERDAYS FRONT. PRECIP PROBABILITIES FOR THIS MORNING WERE
REDUCED GIVEN MODEL AGREEMENT ON LOW INVERSION LEVELS AND DRYING
ALOFT. SLIGHT NUMBERS WERE RETAINED FOR AREAS NORTH AND EAST OF
PITTSBURGH THROUGH THE PREDAWN HOURS.
STRATOCU WILL ERODE BY THE EVENING AS SURFACE RIDGE AXIS SLIDES
OVER THE AREA. WITH DIMINISHED WIND AND CLOUD COVER...RADIATIONAL
COOLING WILL RAPIDLY COMMENCE WITH TEMPERATURES FALLING INTO THE
30S ACROSS THE ENTIRE AREA BY FRIDAY MORNING...AND UPPER 20S ARE
PROJECTED OVER THE RIDGE ZONES AND OVER COUNTIES NORTH OF PITTSBURGH.
WARM...MOIST ADVECTION/MID LEVEL CLOUDINESS IN ADVANCE OF MIDWRN
LOW PRESSURE ARE CURRENTLY PROJECTED TO ARRIVE AT AROUND
DAYBREAK...TOO LATE TO PRECLUDE AREAS OF FROST FOR ALL ZONES.
FREEZE WARNING WAS ISSUED FOR THE NORTHEASTERN HALF OF THE COUNTY
WARNING AREA...WHERE SURFACE RIDGE AXIS WILL CROSS AND WHERE
DRIER AIR WILL SETTLE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AFOREMENTIONED MIDWRN LOW PRES LOOKS TO APPROACH THE AREA ON
FRIDAY...WITH PASSAGE PROJECTED FOR FRIDAY NIGHT...AND SYSTEM EXIT
ON SATURDAY. HAVE GENERALLY PERSISTED WITH PREVIOUS
FORECAST...BUT WITH ADJUSTMENTS TO TIMING AS PER LATEST
DETERMINISTIC MODEL TRENDS. HAVE ALSO INCLUDED A THUNDER MENTION
FOR THE SOUTHERN ZONES ON FRIDAY AFTERNOON GIVEN THE INSTABILITY
PROGNOSIS AND LOW PRESSURE TRACK.
BY SUNDAY...TEMPERATURE MODERATION IS FORECAST TO BE UNDERWAY AS
GREAT LAKES RIDGE AMPLIFIES...BUT SHORTWAVE IN NORTHWEST FLOW MAY
SPAWN SOME SHOWERS GIVEN LATEST MODEL SOLUTIONS. HAVE DECIDED TO
ENTER A SLIGHT CHANCE FOR NOW.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE NEXT LOW WILL TRACK FROM THE UPPER MS VALLEY INTO SOUTHERN
ONTARIO AND WILL PUSH A COLD FRONT THROUGH THE OHIO VALLEY
TUESDAY. SCATTERED SHOWERS SHOULD ACCOMPANY THIS SYSTEM TUESDAY
INTO EARLY WEDNESDAY.
TEMPERATURES ARE FORECAST TO RANGE BETWEEN 10 AND 15 DEGREES ABOVE
NORMAL THROUGH TUESDAY...WITH A RETURN TO NEAR NORMAL READINGS BY
WEDNESDAY.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
RECENT SURFACE AND SATELLITE DATA, COUPLED WITH HRRR AND NAM MODEL
OUTPUT, SHOW COLD POOL MVFR STRATOCUMULUS EXPANDING SOUTHWARD ACROSS
THE UPPER OHIO VALLEY THROUGH 12Z. DAYTIME HEATING WILL INDUCE
VERTICAL MIXING TO CAUSE CLOUD CEILINGS TO LIFT THIS MORNING AND
THEN DISSIPATE, SOUTH TO NORTH, THIS AFTERNOON. EXPECT VFR WITH
MOSTLY CLEAR SKIES TONIGHT.
SURFACE WINDS WILL BE NORTHWEST 10-15 KTS TODAY AND BECOME LIGHT
TONIGHT.
OUTLOOK...FRIDAY THROUGH MONDAY...
RESTRICTIONS ARE POSSIBLE FRIDAY AFTERNOON INTO SATURDAY DUE TO
SHOWERS AND LOW CLOUDS ASSOCIATED WITH PASSING EASTBOUND LOW
PRESSURE SYSTEM. EXPECT MAINLY VFR SUNDAY AND MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR MDZ001.
OH...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR OHZ041.
PA...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR PAZ007>009-
013>016-020>023-029-073>076.
WV...FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR WVZ023-041.
&&
$$
15/11
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
137 AM EDT THU MAR 29 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD TODAY AND PROVIDE DRY...BUT COOLER
WEATHER. RAIN CHANCES ARE SET TO INCREASE ON FRIDAY AS LOW
PRESSURE CROSSES THE REGION. WEEKEND WEATHER WILL FEATURE
IMPROVING CONDITIONS AND MODERATING TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
STRATOCUMULUS BLANKET WILL CONTINUE TO SLIDE SOUTHWARD ACROSS THE
UPPER OHIO REGION AS COLD ADVECTION IS UNDERWAY FOLLOWING PASSAGE
OF YESTERDAYS FRONT. PRECIP PROBABILITIES FOR THIS MORNING WERE
REDUCED GIVEN MODEL AGREEMENT ON LOW INVERSION LEVELS AND DRYING
ALOFT. SLIGHT NUMBERS WERE RETAINED FOR AREAS NORTH AND EAST OF
PITTSBURGH THROUGH THE PREDAWN HOURS.
STRATOCU WILL ERODE BY THE EVENING AS SURFACE RIDGE AXIS SLIDES
OVER THE AREA. WITH DIMINISHED WIND AND CLOUD COVER...RADIATIONAL
COOLING WILL RAPIDLY COMMENCE WITH TEMPERATURES FALLING INTO THE
30S ACROSS THE ENTIRE AREA BY FRIDAY MORNING...AND UPPER 20S ARE
PROJECTED OVER THE RIDGE ZONES AND OVER COUNTIES NORTH OF PITTSBURGH.
WARM...MOIST ADVECTION/MID LEVEL CLOUDINESS IN ADVANCE OF MIDWRN
LOW PRESSURE ARE CURRENTLY PROJECTED TO ARRIVE AT AROUND
DAYBREAK...TOO LATE TO PRECLUDE AREAS OF FROST FOR ALL ZONES. SUB
30 COUNTIES ARE BEING EVALUATED FOR HEADLINES.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AFOREMENTIONED MIDWRN LOW PRES LOOKS TO APPROACH THE AREA ON
FRIDAY...WITH PASSAGE PROJECTED FOR FRIDAY NIGHT...AND SYSTEM EXIT
ON SATURDAY. HAVE GENERALLY PERSISTED WITH PREVIOUS
FORECAST...BUT WITH ADJUSTMENTS TO TIMING AS PER LATEST
DETERMINISTIC MODEL TRENDS. HAVE ALSO INCLUDED A THUNDER MENTION
FOR THE SOUTHERN ZONES ON FRIDAY AFTERNOON GIVEN THE INSTABILITY
PROGNOSIS.
BY SUNDAY...TEMPERATURE MODERATION IS FORECAST TO BE UNDERWAY AS
GREAT LAKES RIDGE AMPLIFIES.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE NEXT LOW WILL TRACK FROM THE UPPER MS VALLEY INTO SOUTHERN
ONTARIO AND WILL PUSH A COLD FRONT THROUGH THE OHIO VALLEY
TUESDAY. SCATTERED SHOWERS SHOULD ACCOMPANY THIS SYSTEM TUESDAY
INTO EARLY WEDNESDAY.
TEMPERATURES ARE FORECAST TO RANGE BETWEEN 10 AND 15 DEGREES ABOVE
NORMAL THROUGH TUESDAY...WITH A RETURN TO NEAR NORMAL READINGS BY
WEDNESDAY.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
RECENT SURFACE AND SATELLITE DATA, COUPLED WITH HRRR AND NAM MODEL
OUTPUT, SHOW COLD POOL MVFR STRATOCUMULUS EXPANDING SOUTHWARD ACROSS
THE UPPER OHIO VALLEY THROUGH 12Z, BEFORE STOPPING NEAR THE I-70
CORRIDOR. DAYTIME HEATING WILL INDUCE VERTICAL MIXING TO CAUSE CLOUD
CEILINGS TO LIFT THIS MORNING AND THEN DISSIPATE, SOUTH TO NORTH,
THIS AFTERNOON. EXPECT VFR WITH MOSTLY CLEAR SKIES TONIGHT.
SURFACE WINDS WILL BE NORTHWEST 10-15 KTS TODAY AND BECOME LIGHT
TONIGHT.
OUTLOOK...FRIDAY THROUGH MONDAY...
RESTRICTIONS ARE POSSIBLE FRIDAY AFTERNOON INTO SATURDAY DUE TO
SHOWERS AND LOW CLOUDS ASSOCIATED WITH PASSING EASTBOUND LOW
PRESSURE SYSTEM. EXPECT MAINLY VFR SUNDAY AND MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
15/11
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1258 AM EDT THU MAR 29 2012
.UPDATE...
ISSUED AT 1214 AM EDT THU MAR 29 2012
RAISED LOW TEMPERATURES A BIT AS CLOUD COVER LOOKS TO BE STUBBORN
AND SLOW TO LEAVE. ALSO KEPT CLOUDS IN FOR THE REST OF TONIGHT
ALMOST EVERYWHERE EXCEPT THE FAR WEST AND SOUTH AS DRIER AIR WORKS
IN.
&&
.SYNOPSIS...
ISSUED AT 355 PM EDT WED MAR 28 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WNW FLOW ALF OVER
THE UPR GRT LKS DOWNSTREAM OF UPR RIDGE IN THE PLAINS. SHRTWV/SFC LO
THAT IMPACTED THE AREA YDAY IS NOW MOVING E THRU QUEBEC...BUT CYC
SFC-H85 NW FLOW OF MOIST AIR REMAINS IN PLACE OVER THE UPR GRT LKS.
A SHRTWV OVER MN IS MOVING SEWD...AND IN CONCERT WITH SOME DEEPER
MSTR SHOWN ON THE 12Z INL RAOB HAS CAUSED SOME SCT -SHRA THAT ARE
MIXING WITH SN AS COLDER AIR ARRIVES FM THE NW...WHERE THE 12Z H85
TEMP WAS AS LO AS -9C AT YPL. BUT UPSTREAM RAOBS SHOW MID LVL DRYING
IN THE WAKE OF THE SHRTWV IS SPREADING SEWD TOWARD THE UPR GRT LKS.
DESPITE THE HIER LVL DRYING...MUCH LO CLD LINGERS IN THE LLVL CYC
FLOW OF THE MOISTER LLVLS DEPICTED ON THE 12Z INL/YPL RAOBS. SOME
CLEARING IS SHOWING UP OVER MANITOBA CLOSER TO DRIER LLVL AIR SHOWN
ON THE 12Z THE PAS RAOB AND SFC HI PRES/RDG AXIS UNDER THE UPR RDG.
FARTHER TO THE W...A STRONG DISTURBANCE HAS COME ASHORE INTO THE PAC
NW.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 355 PM EDT WED MAR 28 2012
MAIN FCST CONCERNS IN THIS PERIOD ARE CLD/CLEARING TRENDS AND TEMPS.
TNGT...UPR RDG/SFC HI PRES RDG AXIS TO THE W ARE FCST TO BUILD INTO
THE UPR GRT LKS. WITH MORE ACYC FLOW AND SOME DRYING...EXPECT AT
LEAST PARTIAL CLRG ESPECIALLY IN DOWNSLOPE AREAS AWAY FM LK SUP IN
SLOWLY VEERING FLOW TO MORE NNE BY 12Z THU. BUT EXTENSIVE CLD COVER
UPSTREAM/LINGERING H925 THERMAL TROF SUGS THE SC WL BE MORE
RESILIENT IN UPSLOPE AREAS NEAR THE LAKE UNDER STRENGTHENING INVRN
ASSOCIATED WITH LARGER SCALE SUBSIDENCE. EXPECT THE LOWEST MIN TEMPS
WELL DOWN IN THE 20S OVER THE INTERIOR W WHERE MORE EXTENSIVE CLRG
IS MOST LIKELY.
THU...AS HI PRES IN ONTARIO DRIFTS SLOWLY TO THE E AND DISTURBANCE
NOW IN THE PAC NW/SFC LO MOVE TOWARD MN LATE...THE LLVL FLOW WL VEER
TO THE E THRU THE DAY. LINGERING LK SC SHOULD SHIFT TO MAINLY OVER
THE HURON MTNS/KEWEENAW AS MID/HIER CLD IN ADVANCE OF APRCHG
DISTURBANCE ARRIVE IN THE AFTN. THE GFS IS MOST AGGRESSIVE AT MOVING
PCPN E INTO THE WRN CWA IN THE AFTN...BUT WL FOLLOW THE SLOWER 12Z
NAM/CNDN/UKMET AND 00Z ECWMF WITH VERY DRY AIRMASS ASSOCIATED WITH
HUDSON BAY HI PRES IN PLACE AND GFS FCST SHARPER QVECTOR CNVGC/FGEN
HOLDING FARTHER TO THE W. MIXING TO H85 ON NAM FCST SDNGS YIELDS HI
TEMPS APRCHG 45 AWAY FM LK MODERATION.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 PM EDT WED MAR 28 2012
THURSDAY NIGHT INTO FRIDAY...SHORTWAVE TROUGH OVER THE NORTHERN
PLAINS POISED TO SLIDE THROUGH THE WESTERN GREAT LAKES BY LATE
THURSDAY NIGHT. INITIALLY JUST TO THE WEST OF CWA LARGE SCALE LIFT
FM THE SHORTWAVE IS COMPLEMENTED NICELY BY 925-850MB WARM AIR
ADVECTION AND DIVERGENCE ALOFT FM JET STREAK OVR ONTARIO. ALL THIS
FORCING IS ACTING ON RATHER MOIST AIRMASS WITH PWATS UP TOWARD 200
PCT OF NORMAL. SINCE PRIMARY SHORTWAVE IS SLIDING MAINLY SOUTH OF
UPR MI AND RIGHT ENTRANCE REGION/H85 THERMAL GRADIENT FADES THROUGH
THE NIGHT...WOULD EXPECT PCPN TO LIGHTEN AS IT MOVES INTO THE CWA
OVERNIGHT. FCST SOUNDINGS POINT TO PTYPE MAINLY TAKING THE FORM OF
SNOW WITH VERY LITTLE IN WAY OF NEAR SFC WARM LAYER ON SOUNDINGS.
BASED ON PREVIOUS MODEL RUNS THIS REPRESENTS A TREND IN THE COOLER
DIRECTION. EXPLICIT QPF OUTPUT WITH THE COLDER TREND WOULD SUGGEST A
FEW INCHES OF SNOW POSSIBLE IN THE INTERIOR WEST OVERNIGHT THURSDAY
NIGHT INTO EARLY FRIDAY. WILL NOT GO WITH THAT MUCH QPF/SNOW YET
THOUGH BASED ON NEGATIVE FACTORS MENTIONED BEFORE. STILL...COULD
SEE AROUND AN INCH OF SNOW OVER INTERIOR WEST AND SCNTRL. MAJORITY
OF PCPN SHOULD EXIT THE SCNTRL/EASTERN CWA FRIDAY AFTN. PLENTY OF
CLOUDS WITH THE PCPN ALONG WITH SE WIND OFF LK MICHIGAN WILL HOLD
DOWN TEMPERATURES OVR MOST OF THE CWA IN THE LOWER-MID 40S.
SHORTWAVE TROUGH SLIDES BY OVER CNTRL CANADA ON SATURDAY BUT MAIN
IMPACTS FM DISTURBANCE FCST TO REMAIN MOSTLY NORTH OF CWA WHERE BEST
LOW-LEVEL WARM ADVECTION OCCURS AND ALONG AND EAST OF TRACK OF
SHORTWAVE. DO HAVE SOME SMALL CHANCES FOR SHOWERS /JUST RAIN AT THIS
POINT/ OVER LK SUPERIOR AND IN NORTHERN CWA ON SATURDAY NIGHT.
IN THE EXTENDED...PIECE OF BROAD UPPER TROUGH OVER THE NORTHERN
PACIFIC IS FORECAST TO EJECT ACROSS THE ROCKIES ON SUNDAY. TROUGH
AND ASSOCIATED DEEPENING SFC LOW THEN SLIDE INTO THE UPR LAKES ON
MONDAY. DETERMINISTIC MEDIUM RANGE MODELS /GFS/ECMWF/CANADIAN/
INDICATE THAT THE UPPER LOW SLOWS UP EARLY NEXT WEEK AND MAY EVEN
TRY TO CUT OFF OVR UPR LAKES AND/OR ONTARIO. NCEP PREFERS THE SLOWER
APPROACH AS MODELS HAVE TRENDED THAT WAY. EVENTUALLY GENERAL RESULT
WILL BE COOLER AND UNSETTLED WEATHER PATTERN THROUGH MIDDLE OF NEXT
WEEK. INITIALLY THOUGH...MONDAY COULD BE ON THE WARMER SIDE OUT
AHEAD OF UPR LOW. ECMWF AND GFS DIFFER ON DETAILS AS GFS SHOWS MUCH
MORE IN WAY OF CLOUDS AND LIGHTER QPF SUNDAY NIGHT INTO MONDAY
MORNING WHILE ECMWF INDICATES A SHARPER COLD FRONT WITH GREATER
POTENTIAL FOR CONVECTION JUST AHEAD OF THE FRONT WITH H7-H5 LAPSE
RATES TO 7C/KM AND SI/S BLO 0C. THERE ALSO APPEARS TO BE ENHANCED
CONVECTIVE POTENTIAL DUE TO SHARPER 1000-850MB MOISTURE FLUX
CONVERGENCE FCST IN AFTN DURING PEAK HEATING. LATEST GFS HAS TRENDED
WARMER WITH INCREASED CHANCE OF CONVECTION. HAVE INTRODUCED CHANCES
FOR THUNDER...FIRST ON SUNDAY NIGHT FOR POSSIBLE ELEVATED CONVECTION
ON EDGE OF INSTABILITY GRADIENT AND THEN ON MONDAY WITH THE FROPA.
COLDER AIR WORKS IN FOR TUESDAY AND WEDNESDAY. GFS IS BROADER AND
LESS AMPLIFIED WITH OVERALL TROUGH WHILE ECMWF INDICATES COOLER AIR
SLOWLY MOVING IN ON TUESDAY WITH STRONGER SHOT OF COLD AIR ARRIVING
BY WEDNESDAY WITH SHARPER COLD FRONT FCST. ALTHOUGH CONSISTENCY IN
HANDLING OF THE TROUGH FM THE MODELS HAS BEEN MUDDLED...DOES APPEAR
TO BE A TREND IN HOLDING ON TO THE TROUGH LONGER AND KEEPING COOLER
TEMPERATURES OVER GREAT LAKES LONGER FURTHER INTO THE WEEK. TREND
MAKES SOME SENSE GIVEN THE AMPLIFIED PATTERN THAT APPEARS TO BE
SETTING UP COMPARED TO MORE ZONAL PATTERN IN PLACE CURRENTLY.
LATEST ECMWF SLOWER YET IN KEEPING COOL TROUGHING OVER GREAT LAKES
AND NORTHEAST INTO LATE NEXT WEEK. TRYING TO PIN DOWN DETAILS TOUGH
AT THIS POINT...BUT THIS KIND OF PATTERN WOULD HAVE POTENTIAL TO
BRING RAIN/SNOW SHOWERS TO UPR LAKES...ENHANCED BY DAYTIME HEATING
AND/OR ANY SHORTWAVES MOVING AROUND THE TROUGH. CONSENSUS POPS SHOW
SMALL CHANCES THROUGH MUCH OF THE EXTENDED WHICH SEEMS ON TRACK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1258 AM EDT THU MAR 29 2012
ALTHOUGH ACYC FLOW/SOME LOW LEVEL DRYING HAVE BROUGHT CIGS UP INTO
THE VFR RANGE. HOWEVER...A RETURN TO MVFR CIGS IS EXPECTED OVERNIGHT
AT SAW AND CMX AS NE OR ENE UPSLOPE FLOW DEVELOPS AS WINDS BACK.
BY THURSDAY AFTERNOON...EXPECT ANY LINGERING MVFR CIGS TO SCATTER
OUT AS MIXING/DRYING INCREASES. MID CLOUDS WILL THICKEN THIS EVENING
AHEAD OF A WARM FRONT TO THE SOUTHWEST. HOWEVER...ANY LOWER CIGS
VSBY WITH PCPN MOVING INTO THE AREA SHOULD HOLD OFF UNTIL AFTER THE
TAF PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 PM EDT WED MAR 28 2012
EXPECT NW WINDS UP TO 30 KTS EARLY OVER THE E HALF TO DIMINISH
TONIGHT AS HI PRES RIDGE BUILDS OVERHEAD. AS THE HI CENTER SHIFTS
EWD TOWARD HUDSON BAY ON THU...A STRONGER E WIND UP TO 25 KTS WILL
DEVELOP OVER WESTERN LK SUP WHERE TERRAIN ENHANCES THIS FLOW. GUSTY
EAST WINDS SHOULD CONTINUE ON THE LAKE INTO FRIDAY MORNING. AFTER A
BRIEF LULL...SOUTH WINDS INCREASE TO 30 KTS ON EAST HALF OF LK
SUPERIOR BY SATURDAY AFTN. WINDS SHOULD SETTLE DOWN INTO SUNDAY AS
PRESSURE GRADIENT WEAKENS. ANOTHER LOW PRESSURE SYSTEM...POSSIBLY
SLOW MOVING...IS EXPECTED TO AFFECT THE WESTERN GREAT LAKES EARLY
NEXT WEEK. COULD SEE WINDS UP TO 30 KTS WITH THIS SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...07
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...JLA
AVIATION...JLB
MARINE...KC
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1215 AM EDT THU MAR 29 2012
.UPDATE...
ISSUED AT 1214 AM EDT THU MAR 29 2012
RAISED LOW TEMPERATURES A BIT AS CLOUD COVER LOOKS TO BE STUBBORN
AND SLOW TO LEAVE. ALSO KEPT CLOUDS IN FOR THE REST OF TONIGHT
ALMOST EVERYWHERE EXCEPT THE FAR WEST AND SOUTH AS DRIER AIR WORKS
IN.
&&
.SYNOPSIS...
ISSUED AT 355 PM EDT WED MAR 28 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WNW FLOW ALF OVER
THE UPR GRT LKS DOWNSTREAM OF UPR RIDGE IN THE PLAINS. SHRTWV/SFC LO
THAT IMPACTED THE AREA YDAY IS NOW MOVING E THRU QUEBEC...BUT CYC
SFC-H85 NW FLOW OF MOIST AIR REMAINS IN PLACE OVER THE UPR GRT LKS.
A SHRTWV OVER MN IS MOVING SEWD...AND IN CONCERT WITH SOME DEEPER
MSTR SHOWN ON THE 12Z INL RAOB HAS CAUSED SOME SCT -SHRA THAT ARE
MIXING WITH SN AS COLDER AIR ARRIVES FM THE NW...WHERE THE 12Z H85
TEMP WAS AS LO AS -9C AT YPL. BUT UPSTREAM RAOBS SHOW MID LVL DRYING
IN THE WAKE OF THE SHRTWV IS SPREADING SEWD TOWARD THE UPR GRT LKS.
DESPITE THE HIER LVL DRYING...MUCH LO CLD LINGERS IN THE LLVL CYC
FLOW OF THE MOISTER LLVLS DEPICTED ON THE 12Z INL/YPL RAOBS. SOME
CLEARING IS SHOWING UP OVER MANITOBA CLOSER TO DRIER LLVL AIR SHOWN
ON THE 12Z THE PAS RAOB AND SFC HI PRES/RDG AXIS UNDER THE UPR RDG.
FARTHER TO THE W...A STRONG DISTURBANCE HAS COME ASHORE INTO THE PAC
NW.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 355 PM EDT WED MAR 28 2012
MAIN FCST CONCERNS IN THIS PERIOD ARE CLD/CLEARING TRENDS AND TEMPS.
TNGT...UPR RDG/SFC HI PRES RDG AXIS TO THE W ARE FCST TO BUILD INTO
THE UPR GRT LKS. WITH MORE ACYC FLOW AND SOME DRYING...EXPECT AT
LEAST PARTIAL CLRG ESPECIALLY IN DOWNSLOPE AREAS AWAY FM LK SUP IN
SLOWLY VEERING FLOW TO MORE NNE BY 12Z THU. BUT EXTENSIVE CLD COVER
UPSTREAM/LINGERING H925 THERMAL TROF SUGS THE SC WL BE MORE
RESILIENT IN UPSLOPE AREAS NEAR THE LAKE UNDER STRENGTHENING INVRN
ASSOCIATED WITH LARGER SCALE SUBSIDENCE. EXPECT THE LOWEST MIN TEMPS
WELL DOWN IN THE 20S OVER THE INTERIOR W WHERE MORE EXTENSIVE CLRG
IS MOST LIKELY.
THU...AS HI PRES IN ONTARIO DRIFTS SLOWLY TO THE E AND DISTURBANCE
NOW IN THE PAC NW/SFC LO MOVE TOWARD MN LATE...THE LLVL FLOW WL VEER
TO THE E THRU THE DAY. LINGERING LK SC SHOULD SHIFT TO MAINLY OVER
THE HURON MTNS/KEWEENAW AS MID/HIER CLD IN ADVANCE OF APRCHG
DISTURBANCE ARRIVE IN THE AFTN. THE GFS IS MOST AGGRESSIVE AT MOVING
PCPN E INTO THE WRN CWA IN THE AFTN...BUT WL FOLLOW THE SLOWER 12Z
NAM/CNDN/UKMET AND 00Z ECWMF WITH VERY DRY AIRMASS ASSOCIATED WITH
HUDSON BAY HI PRES IN PLACE AND GFS FCST SHARPER QVECTOR CNVGC/FGEN
HOLDING FARTHER TO THE W. MIXING TO H85 ON NAM FCST SDNGS YIELDS HI
TEMPS APRCHG 45 AWAY FM LK MODERATION.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 PM EDT WED MAR 28 2012
THURSDAY NIGHT INTO FRIDAY...SHORTWAVE TROUGH OVER THE NORTHERN
PLAINS POISED TO SLIDE THROUGH THE WESTERN GREAT LAKES BY LATE
THURSDAY NIGHT. INITIALLY JUST TO THE WEST OF CWA LARGE SCALE LIFT
FM THE SHORTWAVE IS COMPLEMENTED NICELY BY 925-850MB WARM AIR
ADVECTION AND DIVERGENCE ALOFT FM JET STREAK OVR ONTARIO. ALL THIS
FORCING IS ACTING ON RATHER MOIST AIRMASS WITH PWATS UP TOWARD 200
PCT OF NORMAL. SINCE PRIMARY SHORTWAVE IS SLIDING MAINLY SOUTH OF
UPR MI AND RIGHT ENTRANCE REGION/H85 THERMAL GRADIENT FADES THROUGH
THE NIGHT...WOULD EXPECT PCPN TO LIGHTEN AS IT MOVES INTO THE CWA
OVERNIGHT. FCST SOUNDINGS POINT TO PTYPE MAINLY TAKING THE FORM OF
SNOW WITH VERY LITTLE IN WAY OF NEAR SFC WARM LAYER ON SOUNDINGS.
BASED ON PREVIOUS MODEL RUNS THIS REPRESENTS A TREND IN THE COOLER
DIRECTION. EXPLICIT QPF OUTPUT WITH THE COLDER TREND WOULD SUGGEST A
FEW INCHES OF SNOW POSSIBLE IN THE INTERIOR WEST OVERNIGHT THURSDAY
NIGHT INTO EARLY FRIDAY. WILL NOT GO WITH THAT MUCH QPF/SNOW YET
THOUGH BASED ON NEGATIVE FACTORS MENTIONED BEFORE. STILL...COULD
SEE AROUND AN INCH OF SNOW OVER INTERIOR WEST AND SCNTRL. MAJORITY
OF PCPN SHOULD EXIT THE SCNTRL/EASTERN CWA FRIDAY AFTN. PLENTY OF
CLOUDS WITH THE PCPN ALONG WITH SE WIND OFF LK MICHIGAN WILL HOLD
DOWN TEMPERATURES OVR MOST OF THE CWA IN THE LOWER-MID 40S.
SHORTWAVE TROUGH SLIDES BY OVER CNTRL CANADA ON SATURDAY BUT MAIN
IMPACTS FM DISTURBANCE FCST TO REMAIN MOSTLY NORTH OF CWA WHERE BEST
LOW-LEVEL WARM ADVECTION OCCURS AND ALONG AND EAST OF TRACK OF
SHORTWAVE. DO HAVE SOME SMALL CHANCES FOR SHOWERS /JUST RAIN AT THIS
POINT/ OVER LK SUPERIOR AND IN NORTHERN CWA ON SATURDAY NIGHT.
IN THE EXTENDED...PIECE OF BROAD UPPER TROUGH OVER THE NORTHERN
PACIFIC IS FORECAST TO EJECT ACROSS THE ROCKIES ON SUNDAY. TROUGH
AND ASSOCIATED DEEPENING SFC LOW THEN SLIDE INTO THE UPR LAKES ON
MONDAY. DETERMINISTIC MEDIUM RANGE MODELS /GFS/ECMWF/CANADIAN/
INDICATE THAT THE UPPER LOW SLOWS UP EARLY NEXT WEEK AND MAY EVEN
TRY TO CUT OFF OVR UPR LAKES AND/OR ONTARIO. NCEP PREFERS THE SLOWER
APPROACH AS MODELS HAVE TRENDED THAT WAY. EVENTUALLY GENERAL RESULT
WILL BE COOLER AND UNSETTLED WEATHER PATTERN THROUGH MIDDLE OF NEXT
WEEK. INITIALLY THOUGH...MONDAY COULD BE ON THE WARMER SIDE OUT
AHEAD OF UPR LOW. ECMWF AND GFS DIFFER ON DETAILS AS GFS SHOWS MUCH
MORE IN WAY OF CLOUDS AND LIGHTER QPF SUNDAY NIGHT INTO MONDAY
MORNING WHILE ECMWF INDICATES A SHARPER COLD FRONT WITH GREATER
POTENTIAL FOR CONVECTION JUST AHEAD OF THE FRONT WITH H7-H5 LAPSE
RATES TO 7C/KM AND SI/S BLO 0C. THERE ALSO APPEARS TO BE ENHANCED
CONVECTIVE POTENTIAL DUE TO SHARPER 1000-850MB MOISTURE FLUX
CONVERGENCE FCST IN AFTN DURING PEAK HEATING. LATEST GFS HAS TRENDED
WARMER WITH INCREASED CHANCE OF CONVECTION. HAVE INTRODUCED CHANCES
FOR THUNDER...FIRST ON SUNDAY NIGHT FOR POSSIBLE ELEVATED CONVECTION
ON EDGE OF INSTABILITY GRADIENT AND THEN ON MONDAY WITH THE FROPA.
COLDER AIR WORKS IN FOR TUESDAY AND WEDNESDAY. GFS IS BROADER AND
LESS AMPLIFIED WITH OVERALL TROUGH WHILE ECMWF INDICATES COOLER AIR
SLOWLY MOVING IN ON TUESDAY WITH STRONGER SHOT OF COLD AIR ARRIVING
BY WEDNESDAY WITH SHARPER COLD FRONT FCST. ALTHOUGH CONSISTENCY IN
HANDLING OF THE TROUGH FM THE MODELS HAS BEEN MUDDLED...DOES APPEAR
TO BE A TREND IN HOLDING ON TO THE TROUGH LONGER AND KEEPING COOLER
TEMPERATURES OVER GREAT LAKES LONGER FURTHER INTO THE WEEK. TREND
MAKES SOME SENSE GIVEN THE AMPLIFIED PATTERN THAT APPEARS TO BE
SETTING UP COMPARED TO MORE ZONAL PATTERN IN PLACE CURRENTLY.
LATEST ECMWF SLOWER YET IN KEEPING COOL TROUGHING OVER GREAT LAKES
AND NORTHEAST INTO LATE NEXT WEEK. TRYING TO PIN DOWN DETAILS TOUGH
AT THIS POINT...BUT THIS KIND OF PATTERN WOULD HAVE POTENTIAL TO
BRING RAIN/SNOW SHOWERS TO UPR LAKES...ENHANCED BY DAYTIME HEATING
AND/OR ANY SHORTWAVES MOVING AROUND THE TROUGH. CONSENSUS POPS SHOW
SMALL CHANCES THROUGH MUCH OF THE EXTENDED WHICH SEEMS ON TRACK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 748 PM EDT WED MAR 28 2012
ALTHOUGH MORE ACYC FLOW/SOME LOW LEVEL DRYING WILL RESULT KEEP VFR
CONDITIONS AT CMX/IWD. HOWEVER...MVFR CONDITIONS SHOULD LINGER
TONIGHT THROUGH THU MORNING AT KSAW WHERE MORE UPSLOPE FLOW
PREVAILS. A RETURN TO MVFR CIGS MAY ALSO BE POSSIBLE AT KCMX AS
WINDS BACK MORE TO THE ENE. BY THURSDAY AFTERNOON...EXPECT ANY
LINGERING MVFR CIGS TO SCATTER OUT AS MIXING/DRYING INCREASES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 PM EDT WED MAR 28 2012
EXPECT NW WINDS UP TO 30 KTS EARLY OVER THE E HALF TO DIMINISH
TONIGHT AS HI PRES RIDGE BUILDS OVERHEAD. AS THE HI CENTER SHIFTS
EWD TOWARD HUDSON BAY ON THU...A STRONGER E WIND UP TO 25 KTS WILL
DEVELOP OVER WESTERN LK SUP WHERE TERRAIN ENHANCES THIS FLOW. GUSTY
EAST WINDS SHOULD CONTINUE ON THE LAKE INTO FRIDAY MORNING. AFTER A
BRIEF LULL...SOUTH WINDS INCREASE TO 30 KTS ON EAST HALF OF LK
SUPERIOR BY SATURDAY AFTN. WINDS SHOULD SETTLE DOWN INTO SUNDAY AS
PRESSURE GRADIENT WEAKENS. ANOTHER LOW PRESSURE SYSTEM...POSSIBLY
SLOW MOVING...IS EXPECTED TO AFFECT THE WESTERN GREAT LAKES EARLY
NEXT WEEK. COULD SEE WINDS UP TO 30 KTS WITH THIS SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...07
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...JLA
AVIATION...JLB
MARINE...KC
AREA FORECAST DISCUSSION...UPDATED FOR 18Z TAFS
NWS TWIN CITIES/CHANHASSEN MN
1255 PM CDT THU MAR 29 2012
.DISCUSSION...ISSUED 317 AM CDT
TEMPERATURES THIS MORNING ARE FINALLY NEAR NORMAL IN A FEW
AREAS ESPECIALLY OVER WEST CENTRAL WISCONSIN WHERE SOME UPPER 20S
TO LOW 30S WERE NOTED...COURTESY OF HIGH PRESSURE AND CLEAR SKIES.
FREEZE WARNING LOOKS GOOD THIS MORNING. ELSEWHERE....INCREASING
MID LEVEL CLOUDS OVER NORTH DAKOTA AND NORTHWEST MINNESOTA IN ZONE
OF DEVELOPING WARM ADVECTION AND MID LEVEL THETA E ADVECTION.
A FEW RETURNS SHOWING UP IN THE REGION BUT SATURATION A FEW HOURS
AWAY YET. THE 06Z RUC SEEMS TO HAVE A DECENT TREND ON THE
INCREASING FGEN FORCING THIS MORNING FOR WEST CENTRAL MINNESOTA.
LOW LOWER LEVEL MOISTURE TRANSPORT STILL BOTTLED UP OVER THE
CENTRAL PLAINS. HAVE DELAYED POPS A BIT TODAY UNTIL THE WAVE OVER
EASTERN ID AND WESTERN WY GETS CLOSER ALONG WITH SOME OF THE
MOISTURE TRANSPORT REACHING IOWA. THE GFS AND NAM BOTH SHOW
PRECIPITABLE WATER VALUES REACHING JUST OVER AN INCH BY 00Z AT MSP
WHICH IS NEAR 2 STANDARD DEVIATIONS ABOVE NORMAL. HAVE RAISED POPS
BY EVENING INTO THE CATEGORICAL AREA OVER AT LEAST THE CENTRAL CWA
AND THEN FARTHER EAST INTO WISCONSIN LATER IN THE EVENING. THE GFS
IS A LITTLE FASTER WITH THE WAVE BUT NOT BY MUCH. MOST LINGERING
PRECIP SHOULD BE CONFINED TO A FEW AREAS OF WEST CENTRAL WISCONSIN
BY FRIDAY MORNING. BEST CHANCE OF ISOLATED THUNDER OVER WEST
CENTRAL MN THIS MORNING INTO THE AFTERNOON WITH THE INITIAL BURST
OF WARM ADVECTION AND THEN MAINLY SOUTHERN HALF OF THE CWA IN THE
AFTERNOON AND EVENING NEAR THE EDGE OF THE DEEPER INSTABILITY
TO UR SOUTH.
LOOKS LIKE LINGERING CLOUDS EASTERN AREAS FRIDAY INTO SATURDAY
MORNING WITH THE DEVELOPING STRONGER WARM FRONT. A LITTLE
CONCERNED ABOUT A FEW SHOWERS DEVELOPING LATER FRIDAY NIGHT AND
SATURDAY MORNING NEAR THE FRONT. WILL LEAVE OUT FOR NOW WITH THE
INITIAL DRIER BEHIND THE DEPARTING WAVE LATER TONIGHT.
STILL LOOKS WARM FOR THE WEEKEND...ESPECIALLY SUNDAY DEEP INTO THE
WARM SECTOR. MIXING DOWN FROM AROUND 875-900MB EVEN YIELDS SOME
LOWER 80S ON THE SOUTH. CHANCES FOR TSTMS LOOK SLIM WITH A CAPPED
ENVIRONMENT INITIALLY BUT SUNDAY NIGHT LOOKS BETTER EASTERN AREAS.
&&
.AVIATION.../18Z TAF ISSUANCE/
BAND OF -SHRA WITH SOME EMBEDDED TSTMS HAS BEEN MOVING NE 25 TO 30
KTS. LEADING EDGE OF THIS BAND RUNS FROM NEAR AXN TO JUST W OF BKX
TO 20W OF FSD. THEY LIE E OF N-S SFC TROF ACROSS THE CENTRAL DKTS
WITH RATHER SHARP MID LVL TROF ACRS THE CNTL DKTS PROVIDING
FAVORABLE VERTICAL MOTION. SB INSTABILITY RATHER WEAK WITH LOW SFC
DWPTS...BUT FAIRLY GOOD ELEVATED MOVING ACROSS AREA THIS
AFTN/EVENING WHICH WILL MAINTAIN A CHANCE OF A FEW TSTMS. AS SHWRS
EXIT AREA IN THE OVERNIGHT...WINDS BECOME LIGHT WITH WEAK TROFFINESS
ACROSS AREA. THIS WILL BRING A GOOD POTENTIAL OF STRATUS ACROSS
AREA WITH POSSIBLY SOME DZL IN THE EAST. CIGS MAY BE SLOW TO IMPROVE
WITH LGT NELY SFC WINDS IN THE MORNING.
MSP...SHWRS WILL APRCH MSP BY 00Z WITH PCPN THEN BECOMING LIKELY
UNTIL AROUND 06Z. ENUF ELEVATED INSTABILTY ACROSS AREA FOR A CHANCE
OF A TSTM EARLY IN THE EVENING. MID CLDS...BASES ARND 10K MOVING
INTO AREA DRNG ERLY/MID AFTN. BY 23Z BASES SHUD BE ARND 5K WITH MVFR
CIGS DVLPG DURING THE EVENINGIN PCPN. BY 09Z EXPECT IFR CIGS AS
STRATUS DEVELOPS WITH POSSIBLY DZL AROUND DAYBREAK. EXPECT MVFR BY
MID MORNING INTO MID AFTN BEFORE BECOMING VFR.
.FRI MORNING...IFR/MVFR CIGS. VFR BY AFTN.
.SAT MORNING...BR/FG POSSIBLE. OTHERWISE VFR.
.SUN.VFR.
.MON...MVFR SHRA/TSRA.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPR/BAP
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
624 AM CDT THU MAR 29 2012
.DISCUSSION...
TEMPERATURES THIS MORNING ARE FINALLY NEAR NORMAL IN A FEW
AREAS ESPECIALLY OVER WEST CENTRAL WISCONSIN WHERE SOME UPPER 20S
TO LOW 30S WERE NOTED...COURTESY OF HIGH PRESSURE AND CLEAR SKIES.
FREEZE WARNING LOOKS GOOD THIS MORNING. ELSEWHERE....INCREASING
MID LEVEL CLOUDS OVER NORTH DAKOTA AND NORTHWEST MINNESOTA IN ZONE
OF DEVELOPING WARM ADVECTION AND MID LEVEL THETA E ADVECTION.
A FEW RETURNS SHOWING UP IN THE REGION BUT SATURATION A FEW HOURS
AWAY YET. THE 06Z RUC SEEMS TO HAVE A DECENT TREND ON THE
INCREASING FGEN FORCING THIS MORNING FOR WEST CENTRAL MINNESOTA.
LOW LOWER LEVEL MOISTURE TRANSPORT STILL BOTTLED UP OVER THE
CENTRAL PLAINS. HAVE DELAYED POPS A BIT TODAY UNTIL THE WAVE OVER
EASTERN ID AND WESTERN WY GETS CLOSER ALONG WITH SOME OF THE
MOISTURE TRANSPORT REACHING IOWA. THE GFS AND NAM BOTH SHOW
PRECIPITABLE WATER VALUES REACHING JUST OVER AN INCH BY 00Z AT MSP
WHICH IS NEAR 2 STANDARD DEVIATIONS ABOVE NORMAL. HAVE RAISED POPS
BY EVENING INTO THE CATEGORICAL AREA OVER AT LEAST THE CENTRAL CWA
AND THEN FARTHER EAST INTO WISCONSIN LATER IN THE EVENING. THE GFS
IS A LITTLE FASTER WITH THE WAVE BUT NOT BY MUCH. MOST LINGERING
PRECIP SHOULD BE CONFINED TO A FEW AREAS OF WEST CENTRAL WISCONSIN
BY FRIDAY MORNING. BEST CHANCE OF ISOLATED THUNDER OVER WEST
CENTRAL MN THIS MORNING INTO THE AFTERNOON WITH THE INITIAL BURST
OF WARM ADVECTION AND THEN MAINLY SOUTHERN HALF OF THE CWA IN THE
AFTERNOON AND EVENING NEAR THE EDGE OF THE DEEPER INSTABILITY
TO UR SOUTH.
LOOKS LIKE LINGERING CLOUDS EASTERN AREAS FRIDAY INTO SATURDAY
MORNING WITH THE DEVELOPING STRONGER WARM FRONT. A LITTLE
CONCERNED ABOUT A FEW SHOWERS DEVELOPING LATER FRIDAY NIGHT AND
SATURDAY MORNING NEAR THE FRONT. WILL LEAVE OUT FOR NOW WITH THE
INITIAL DRIER BEHIND THE DEPARTING WAVE LATER TONIGHT.
STILL LOOKS WARM FOR THE WEEKEND...ESPECIALLY SUNDAY DEEP INTO THE
WARM SECTOR. MIXING DOWN FROM AROUND 875-900MB EVEN YIELDS SOME
LOWER 80S ON THE SOUTH. CHANCES FOR TSTMS LOOK SLIM WITH A CAPPED
ENVIRONMENT INITIALLY BUT SUNDAY NIGHT LOOKS BETTER EASTERN AREAS.
&&
.AVIATION.../12Z TAF ISSUANCE/
MAIN AVIATION CONCERN IS TIMING OF INITIAL CONVECTION ACROSS
WESTERN MN...AND HOW IT TRANSLATES TO THE EAST THIS EVENING
OVERNIGHT.
THE FIRST 6-9 HRS SHOULD BE VFR ALONG WITH INCREASING E/SE WNDS.
CIGS WILL REMAIN AOA 6K. AFT 18-21Z...EXPECT SHRA AND EMBEDDED
TSRA TO DEVELOP NEAR AXN/RWF WITH TEMPORARY MVFR CIGS/VSBYS. THESE
CONDITIONS WILL OCCUR AT STC AFT 00Z...AND AT RNH/MSP BETWEEN
01-03Z. THERE SHOULD BE A PERIOD OF LIGHT TO MODERATE SHRA ALONG
WITH CIGS AVERAGING ARND 2-3K. VSBYS WILL ONLY LOWER IN HEAVIER
SHRA. AFT 3Z...MOST OF THE SHRA SHOULD MOVE EAST OF RWF/AXN WITH
CIGS DROPPING TO IFR. WNDS WILL REMAIN FROM THE SE THRU 00Z...THEN
DECREASE AND BECOME MORE W/NW AFT 3-6Z. TIMING IS THE MOST
IMPORTANT FACTOR IN THIS TAF PERIOD AS UPDATES WILL BE LIKELY AS
SHRA/TSRA DEVELOP.
MSP...VFR CONDITIONS ALONG WITH INCREASING ESE/SE WNDS DURING THE
MORNING. GUSTS UP TO 24 KTS POSSIBLE AFT 18Z...BEFORE DECREASING
DURING THE EVENING AND BECOMING MORE E...THEN NW TOWARD 12Z. MOST
OF THE SHRA/TSRA SHOULD HOLD OFF UNTIL AFT 01Z...WITH A PERIOD
BETWEEN 3-9Z WITH LIGHT TO MODERATE SHRA/TSRA. WILL CONTINUE CB/S
AS TIMING WHEN TSRA DEVELOP IS PROBLEMATIC. EVEN A TEMPORARY IS
NOT NECESSARY AT THIS TIME. LATER SHIFTS CAN PINPOINT THE 1-2 HR
PERIOD WHERE TSRA MOVE ACROSS THE AIRPORT THIS EVENING. CIGS WILL
LIKELY DROP TO MVFR ONCE THE HEAVIER SHRA DEVELOP...WITH IFR CIGS
BY 12Z.
.FRI MORNING...IFR/MVFR CIGS. VFR BY AFTN.
.SAT MORNING...BR/FG POSSIBLE. OTHERWISE VFR.
.SUN.VFR.
.MON...MVFR SHRA/TSRA.
.JLT..
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...FREEZE WARNING UNTIL 9 AM CDT THIS MORNING FOR BARRON-CHIPPEWA-
DUNN-EAU CLAIRE-POLK-RUSK.
&&
$$
JPR/JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
317 AM CDT THU MAR 29 2012
.DISCUSSION...
TEMPERATURES THIS MORNING ARE FINALLY NEAR NORMAL IN A FEW
AREAS ESPECIALLY OVER WEST CENTRAL WISCONSIN WHERE SOME UPPER 20S
TO LOW 30S WERE NOTED...COURTESY OF HIGH PRESSURE AND CLEAR SKIES.
FREEZE WARNING LOOKS GOOD THIS MORNING. ELSEWHERE....INCREASING
MID LEVEL CLOUDS OVER NORTH DAKOTA AND NORTHWEST MINNESOTA IN ZONE
OF DEVELOPING WARM ADVECTION AND MID LEVEL THETA E ADVECTION.
A FEW RETURNS SHOWING UP IN THE REGION BUT SATURATION A FEW HOURS
AWAY YET. THE 06Z RUC SEEMS TO HAVE A DECENT TREND ON THE
INCREASING FGEN FORCING THIS MORNING FOR WEST CENTRAL MINNESOTA.
LOW LOWER LEVEL MOISTURE TRANSPORT STILL BOTTLED UP OVER THE
CENTRAL PLAINS. HAVE DELAYED POPS A BIT TODAY UNTIL THE WAVE OVER
EASTERN ID AND WESTERN WY GETS CLOSER ALONG WITH SOME OF THE
MOISTURE TRANSPORT REACHING IOWA. THE GFS AND NAM BOTH SHOW
PRECIPITABLE WATER VALUES REACHING JUST OVER AN INCH BY 00Z AT MSP
WHICH IS NEAR 2 STANDARD DEVIATIONS ABOVE NORMAL. HAVE RAISED POPS
BY EVENING INTO THE CATEGORICAL AREA OVER AT LEAST THE CENTRAL CWA
AND THEN FARTHER EAST INTO WISCONSIN LATER IN THE EVENING. THE GFS
IS A LITTLE FASTER WITH THE WAVE BUT NOT BY MUCH. MOST LINGERING
PRECIP SHOULD BE CONFINED TO A FEW AREAS OF WEST CENTRAL WISCONSIN
BY FRIDAY MORNING. BEST CHANCE OF ISOLATED THUNDER OVER WEST
CENTRAL MN THIS MORNING INTO THE AFTERNOON WITH THE INITIAL BURST
OF WARM ADVECTION AND THEN MAINLY SOUTHERN HALF OF THE CWA IN THE
AFTERNOON AND EVENING NEAR THE EDGE OF THE DEEPER INSTABILITY
TO UR SOUTH.
LOOKS LIKE LINGERING CLOUDS EASTERN AREAS FRIDAY INTO SATURDAY
MORNING WITH THE DEVELOPING STRONGER WARM FRONT. A LITTLE
CONCERNED ABOUT A FEW SHOWERS DEVELOPING LATER FRIDAY NIGHT AND
SATURDAY MORNING NEAR THE FRONT. WILL LEAVE OUT FOR NOW WITH THE
INITIAL DRIER BEHIND THE DEPARTING WAVE LATER TONIGHT.
STILL LOOKS WARM FOR THE WEEKEND...ESPECIALLY SUNDAY DEEP INTO THE
WARM SECTOR. MIXING DOWN FROM AROUND 875-900MB EVEN YIELDS SOME
LOWER 80S ON THE SOUTH. CHANCES FOR TSTMS LOOK SLIM WITH A CAPPED
ENVIRONMENT INTITIALLY BUT SUNDAY NIGHT LOOKS BETTER EASTERN AREAS.
&&
.AVIATION.../06Z TAF ISSUANCE/
JUST SOME PATCHY CIRRUS CLOUDS OVERNIGHT BEFORE MID DECK OF CLOUDS
ROLL INTO WESTERN MN BY MID OR LATE MORNING. WEATHER CONDITIONS
REMAINING VFR THROUGH MID AFTERNOON THURSDAY...THEN SCATTERED SHRA
DEVELOPING AHEAD OF LOW PRESSURE TROUGH. SOME WEAK INSTABILITY OVER
THE FORECAST AREA THURSDAY AFTERNOON/EVENING. ONLY EXPECT SOME
ISOLATED THUNDERSTORMS EMBEDDED IN THE AREA OF RAINSHOWERS.
THERE ARE HIGHER PROBABILITIES FOR THUNDERSTORMS WELL TO THE SOUTH
OF THE AREA WHERE THE INSTABILITY WILL MUCH BETTER. ONCE THE SHOWERS
MOVE IN...THERE IS ROUGHLY A 3-5 HOUR WINDOW WHEN THE TAF SITES
COULD SEE THE RAIN. A LOT OF 5000-7000 CEILINGS TOMORROW...WITH
POTENTIAL FOR CEILINGS TO LOWER TO 3000-4000FT UNDER THE HEAVIER
SHOWER AND PERHAPS BRIEFLY YIELDING A 4-5SM VISIBILITY. MUCH BETTER
CHANCES FOR MVFR CEILINGS BEHIND THE SHOWERS THURSDAY NIGHT.
KMSP...NO PROBLEM TONIGHT THROUGH THURSDAY AFTERNOON. VFR FLYING
CONDITIONS PREVAILING THROUGH THE BULK OF THE PERIOD. RAIN
DEVELOPING AFTER 400 PM...WITH POSSIBLY AN EMBEDDED THUNDERSTORM
BEFORE MIDNIGHT. CEILINGS COULD LOWER BRIEFLY AROUND 3000-4000 FEET
AGL AND VISIBILITIES 5 TO 6 MILES IN HEAVIER SHOWERS ESPECIALLY
TOMORROW EVENING.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...FREEZE WARNING UNTIL 9 AM CDT THIS MORNING FOR BARRON-CHIPPEWA-
DUNN-EAU CLAIRE-POLK-RUSK.
&&
$$
JPR/JVM
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
310 PM CDT THU MAR 29 2012
.SHORT TERM...
ISSUED AT 204 PM CDT THU MAR 29 2012
(TONIGHT)
CONVECTION THAT HAS PERSISTED OVER NORTHWEST MISSOURI THE PAST
SEVERAL HOURS HAS SHOWN SLOW EAST SOUTHEASTWARD MOVEMENT IN THE
LAST HOUR OR TWO. THIS CONVECTION IS OCCURRING JUST NORTH OF A
WARM FRONT FROM THE KANSAS CITY METRO AREA TO SOUTH OF JEFFERSON
CITY. THIS FRONT WILL MOVE SLOWLY NORTH THE REST OF THE AFTERNOON
INTO TONIGHT IN RESPONSE TO THE TROUGH NOW MOVING EAST INTO THE
CENTRAL PLAINS. THE RUC IS SHOWING THAT THE BEST LOW LEVEL
MOISTURE CONVERGENCE WILL BE SHIFTING TO THE NORTHEAST WITH
TIME...SO WILL CONTINUE WITH SCT SHRA/TSRA BASICALLY ALONG AND
NORTH OF I-70 INTO EARLY THIS EVENING.
THEREAFTER...WARM FRONT WILL MOVE NORTH THIS EVENING. LOCAL VERSION
OF THE WRF AND GFS SHOWS 925-850MB MOISTURE CONVERGENCE MOVING
NORTH OF THE AREA THIS EVENING. MORE CONCENTRATED POTENTIAL FOR
ADDITIONAL THUNDERSTORMS WILL OCCUR AFTER MIDNIGHT AS A COLD FRONT
ASSOCIATED WITH THE AFOREMENTIONED TROUGH MOVES EASTWARD THROUGH
MISSOURI. HAVE KEPT LIKELY POPS OVER NORTHEAST MO/WEST CENTRAL IL
WHICH WILL BE CLOSEST TO THE TRACK OF THE ATTENDANT SURFACE LOW...
WITH SCATTERED THUNDERSTORMS TO THE SOUTH. MUCAPES IN THE 500-1000
J/KG RANGE AND DEEP LAYER SHEAR OF 30-40KTS SUGGEST THERE MAY
STILL BE A FEW STRONG STORMS CAPABLE OF PRODUCING HAIL AND GUSTY
WINDS INTO THE OVERNIGHT HOURS.
BRITT
&&
.LONG TERM...
ISSUED AT 309 PM CDT THU MAR 29 2012
(FRIDAY THROUGH THURSDAY)
GUIDANCE MOVES THE SURFACE LOW ACROSS NORTHERN ILLINOIS FRIDAY
MORNING WITH THE ATTENDANT WEAK COLD FRONT DROPPING THROUGH THE CWFA
INTO SOUTHERN MISSOURI BY 00-06Z SATURDAY. FORECAST SOUNDINGS ARE
INDICATING A WEAK CAP WITH MODEST INSTABILITY OF 1000-1500 J/KG.
CONVERGENCE ON THE FRONT DOESN`T LOOK VERY IMPRESSIVE...BUT THINK
SCATTERED THUNDERSTORMS WILL CONTINUE AS THE FRONT MOVES SOUTH.
WIND WILL QUICKLY SHIFT BACK TO THE SOUTH ON SATURDAY ALLOWING
TEMPERATURES TO ONCE AGAIN CLIMB INTO THE MID 70S TO LOW 80S. THE
GFS IS KICKING OUT A LITTLE OZARK-EFFECT DIURNAL CONVECTION LATE
SATURDAY AFTERNOON/EVENING AND THIS LOOKS REASONABLE GIVEN THE
PATTERN SO HAVE INCREASED POPS TO SLIGHT CHANCE ACROSS SOUTHERN
PORTIONS OF THE AREA. LOW LEVEL JET RAMPS UP LATE SATURDAY
NIGHT...ESPECIALLY ACROSS PARTS OF IOWA AND ILLINOIS AND BOTH THE
GFS AND NAM ARE PRINTING OUT PRECIP IN THOSE AREAS. LOW LEVEL
MOISTURE CONVERGENCE SIGNATURES ARE VERY BROAD AND COULD INDICATE
PRECIP ALMOST ANYWHERE IN EASTERN IOWA/WESTERN ILLINOIS. THINK SOME
RAIN IS LIKELY SOMEWHERE IN THAT AREA...BUT AM UNSURE WHAT THE
COVERAGE...STRENGTH...OR DURATION OF THE CONVECTION WILL BE. HAVE
THEREFORE DECIDED TO BE CONSERVATIVE AND ONLY INCREASED POPS TO
SLIGHT CHANCE THROUGH 12Z SUNDAY MORNING. WARM ADVECTION CONTINUES
SUNDAY WITH 850MB TEMPS BETWEEN 16-18C WHICH SHOULD EASILY PRODUCE
HIGHS IN THE LOW TO MID 80S ACROSS THE ENTIRE AREA...UNLESS THE
SATURDAY NIGHT CONVECTION IS STRONGER THAN ANTICIPATED AND COOLS THE
ATMOSPHERE OFF MORE THAN ANTICIPATED.
MEDIUM RANGE MODELS CONTINUE TO BRING A SHARP TROF OUT FROM THE
GREAT PLAINS ACROSS THE MIDWEST EARLY NEXT WEEK. WITH THE GULF OPEN
AND PLENTY OF MOISTURE AVAILABLE WE SHOULD SEE INCREASING COVERAGE
OF CONVECTION MONDAY AND MONDAY NIGHT AHEAD OF THE COLD FRONT
ASSOCIATED WITH THIS WAVE. ECMWF IS FASTER AND KEEPS AN OPEN WAVE
MOVING THROUGH THE AREA BY LATE MONDAY NIGHT WHILE THE GFS CLOSES
THE WAVE OFF AND HOLDS PRECIP BACK OVER THE AREA INTO TUESDAY
NIGHT. GEM IS MORE SIMILAR TO THE GFS...SO KEPT CHANCE POPS GOING
THROUGH TUESDAY BUT ENDED PRECIP TUESDAY NIGHT. TEMPERATURES WILL
FALL CLOSER TO CLIMATOLOGICAL AVERAGE BEHIND THE FRONT WEDNESDAY AND
THURSDAY.
CARNEY
&&
.AVIATION...
ISSUED AT 1250 PM CDT THU MAR 29 2012
COMPLEX OF THUNDERSTORMS OVER NORTHWEST MISSOURI IS MOVING SLOWLY
EASTWARD AND CURRENTLY BELIEVE THAT IT WILL STAY NORTH OF KCOU AND
THE ST. METRO ARE TAF SITES. IF THE SYSTEM DOES TURN SLIGHTLY
SOUTHEASTWARD AND MAINTAINS ITS STRENGTH...THEN AMENDMENTS WILL BE
REQUIRED FOR ALL OF THESE SITES TO INCLUDE TEMPO FOR TSRA. EXPECT
THERE WILL BE A PERIOD OF DRY WEATHER THIS EVENING BEFORE A COLD
FRONT APPROACHES THE AREA FROM THE WEST LATE TONIGHT AND EARLY
FRIDAY. HAVE ADDED VCSH WITH A CB GROUP TO ACCOMMODATE THE
POTENTIAL FOR SCATTERED THUNDERSTORMS MOVING ALONG THE FRONT.
WINDS IN THE ST. METRO AREA ARE CURRENTLY BEING INFLUENCED BY
DECAYING THUNDERSTORMS...BUT SHOULD TURN EASTERLY AND SLOWLY BACK
THROUGH THE TAF PERIOD.
SPECIFICS FOR KSTL...HAVE GONE INITIALLY WITH A DRY CONDITIONS
FOR THIS AFTERNOON. IF THE THUNDERSTORM COMPLEX TO THE NORTHWEST
OF KCOU HOLDS TOGETHER AND MOVES SLIGHTLY MORE SOUTHEAST...THEN IT
MAY AFFECT THE EVENING RUSH HOUR AFTER 23Z. OTHERWISE EXPECT
MAINLY DRY AND VFR CONDITIONS...THOUGH SCATTERED THUNDERSTORMS MAY
DEVELOP AHEAD OF A COLD FRONT THAT WILL MOVE THROUGH THE TERMINAL
LATE ON FRIDAY MORNING.
BRITT
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 59 77 53 79 / 40 40 10 10
QUINCY 56 73 50 78 / 60 50 10 10
COLUMBIA 60 76 54 81 / 50 30 10 10
JEFFERSON CITY 60 77 53 81 / 50 30 10 10
SALEM 55 77 50 74 / 20 30 10 10
FARMINGTON 58 77 52 80 / 20 30 10 20
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
204 PM CDT THU MAR 29 2012
.SHORT TERM...
ISSUED AT 204 PM CDT THU MAR 29 2012
(TONIGHT)
CONVECTION THAT HAS PERSISTED OVER NORTHWEST MISSOURI THE PAST
SEVERAL HOURS HAS SHOWN SLOW EAST SOUTHEASTWARD MOVEMENT IN THE
LAST HOUR OR TWO. THIS CONVECTION IS OCCURRING JUST NORTH OF A
WARM FRONT FROM THE KANSAS CITY METRO AREA TO SOUTH OF JEFFERSON
CITY. THIS FRONT WILL MOVE SLOWLY NORTH THE REST OF THE AFTERNOON
INTO TONIGHT IN RESPONSE TO THE TROUGH NOW MOVING EAST INTO THE
CENTRAL PLAINS. THE RUC IS SHOWING THAT THE BEST LOW LEVEL
MOISTURE CONVERGENCE WILL BE SHIFTING TO THE NORTHEAST WITH
TIME...SO WILL CONTINUE WITH SCT SHRA/TSRA BASICALLY ALONG AND
NORTH OF I-70 INTO EARLY THIS EVENING.
THEREAFTER...WARM FRONT WILL MOVE NORTH THIS EVENING. LOCAL VERSION
OF THE WRF AND GFS SHOWS 925-850MB MOISTURE CONVERGENCE MOVING
NORTH OF THE AREA THIS EVENING. MORE CONCENTRATED POTENTIAL FOR
ADDITIONAL THUNDERSTORMS WILL OCCUR AFTER MIDNIGHT AS A COLD FRONT
ASSOCIATED WITH THE AFOREMENTIONED TROUGH MOVES EASTWARD THROUGH
MISSOURI. HAVE KEPT LIKELY POPS OVER NORTHEAST MO/WEST CENTRAL IL
WHICH WILL BE CLOSEST TO THE TRACK OF THE ATTENDANT SURFACE LOW...
WITH SCATTERED THUNDERSTORMS TO THE SOUTH. MUCAPES IN THE 500-1000
J/KG RANGE AND DEEP LAYER SHEAR OF 30-40KTS SUGGEST THERE MAY
STILL BE A FEW STRONG STORMS CAPABLE OF PRODUCING HAIL AND GUSTY
WINDS INTO THE OVERNIGHT HOURS.
BRITT
&&
.LONG TERM...
ISSUED AT 328 AM CDT THU MAR 29 2012
(FRIDAY-WEDNESDAY)
KEPT POPS GOING FRI ALONG THE CDFNT MENTIONED ABOVE. AFTER THIS
SYSTEM MOVES OUT OF THE AREA...DRY CONDITIONS ARE FORECAST THRU
THE WEEKEND. IS SOME QUESTION ABOUT CHANCES FOR TSRA LATE SAT
NIGHT INTO SUN MORNING WITH RETURN FLOW SETUP AND DECENT LLJ OVER
THE AREA. HOWEVER...CHANCES ARE TOO LOW TO MENTION ATTM.
AFTER A BRIEF COOLER PERIOD EXPECTED ON FRI...CONTINUED A WARM
TREND FOR SAT WITH SLY FLOW RETURNING TO THE AREA.
FOR THE EXTD...PERIOD...AND APRIL...EXPECTED TO BEGIN WITH A VERY
WARM DAY. SOME GUIDANCE SUGGESTS TEMPS MAY BE NEAR RECORD HIGHS IN
THE UPPER 80S ACROSS MUCH OF THE REGION. HAVE NOT TRENDED THAT
WARM YET...BUT MDLS CONTINUE TO SUGGEST A VERY WARM PATTERN WITH
H85 TEMPS IN THE 16C TO 20C RANGE. THOUGHT A FORECAST GOING OVER
25 DEGREES ABOVE SEASONAL AVG WAS A GOOD START.
ECMWF/GFS HAVE COME INTO FAIRLY GOOD AGREEMENT FOR MON. WITH THE
GEM AS AN OUTLIER...HAVE TRENDED AWAY FROM THIS SOLN. WITH THE
ECMWF NOW ALSO SUGGESTING PRECIP ALONG THE CDFNT AS IT PUSHES THRU
THE REGION...HAVE RAISED POPS INTO THE CHANCE RANGE FOR MON INTO
MON NIGHT.
TRENDED TWD A GUIDANCE BLEND FOR TUES WITH A BRIEF PERIOD OF TEMPS
NEAR AVG BEFORE SW FLOW SETS UP AGAIN BY WED.
TILLY
&&
.AVIATION...
ISSUED AT 1250 PM CDT THU MAR 29 2012
COMPLEX OF THUNDERSTORMS OVER NORTHWEST MISSOURI IS MOVING SLOWLY
EASTWARD AND CURRENTLY BELIEVE THAT IT WILL STAY NORTH OF KCOU AND
THE ST. METRO ARE TAF SITES. IF THE SYSTEM DOES TURN SLIGHTLY
SOUTHEASTWARD AND MAINTAINS ITS STRENGTH...THEN AMENDMENTS WILL BE
REQUIRED FOR ALL OF THESE SITES TO INCLUDE TEMPO FOR TSRA. EXPECT
THERE WILL BE A PERIOD OF DRY WEATHER THIS EVENING BEFORE A COLD
FRONT APPROACHES THE AREA FROM THE WEST LATE TONIGHT AND EARLY
FRIDAY. HAVE ADDED VCSH WITH A CB GROUP TO ACCOMMODATE THE
POTENTIAL FOR SCATTERED THUNDERSTORMS MOVING ALONG THE FRONT.
WINDS IN THE ST. METRO AREA ARE CURRENTLY BEING INFLUENCED BY
DECAYING THUNDERSTORMS...BUT SHOULD TURN EASTERLY AND SLOWLY BACK
THROUGH THE TAF PERIOD.
SPECIFICS FOR KSTL...HAVE GONE INITIALLY WITH A DRY CONDITIONS
FOR THIS AFTERNOON. IF THE THUNDERSTORM COMPLEX TO THE NORTHWEST
OF KCOU HOLDS TOGETHER AND MOVES SLIGHTLY MORE SOUTHEAST...THEN IT
MAY AFFECT THE EVENING RUSH HOUR AFTER 23Z. OTHERWISE EXPECT
MAINLY DRY AND VFR CONDITIONS...THOUGH SCATTERED THUNDERSTORMS MAY
DEVELOP AHEAD OF A COLD FRONT THAT WILL MOVE THROUGH THE TERMINAL
LATE ON FRIDAY MORNING.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1251 PM CDT THU MAR 29 2012
.UPDATE...
ISSUED AT 1250 PM CDT THU MAR 29 2012
HAVE LEFT CHANCE POPS GOING BASICALLY NORTH OF INTERSTATE 70 FOR
THE REMAINDER TO THE AFTERNOON. CONVECTION OVER NORTHWEST
MISSOURI HAS ONLY RECENTLY SHOWN SOME SLOW EASTWARD PROPAGATION IN
THE LAST HOUR. THE RUC 925-850MB MOISTURE CONVERGENCE HAS HAD THE
BEST HANDLE ON THE DEVELOPMENT AND DEPICTS THAT IT WILL BE MOVING
NORTHEAST MO/WEST CENTRAL IL BY 00Z. HAVE ADJUSTED AFTERNOON
TEMPERATURES DOWNWARD BASED ON CLOUDS/RAIN CHANCES.
BRITT
&&
.SHORT TERM...
ISSUED AT 328 AM CDT THU MAR 29 2012
(TODAY-TONIGHT)
EXPECT ONGOING PRECIP TO GRADUALLY WEAKEN THIS MORNING ACROSS THE
AREA AND SHUD REFOCUS TO THE N AND W. THE EXACT TIMING OF THIS IS
ALSO UNCERTAIN...BUT EXPECT MOST OF THE CWA TO BE DRY BY NOON.
HOWEVER...CHANCES FOR TSRA SHUD INCREASE AGAIN THIS AFTERNOON
ALONG THE SFC WRMFNT. MDLS DIFFER EXACTLY WHERE THE WRMFNT WILL BE
LOCATED THIS AFTERNOON WITH THE NAM WITH A SRN OUTLIER SOLN.
BELIEVE THE NAM IS TOO FAR S...BUT THE ECMWF/GFS ARE LIKELY TOO
FAR N GIVEN THE CONVECTION THIS MORNING. HAVE TRENDED TWD A
COMPROMISE FCST WHICH IS CLOSE TO THE LOCAL WRF.
THIS WILL HAVE A LARGE IMPACT ON TEMPS FOR TODAY. TEMPS SHUD CLIMB
INTO THE 80S S OF THE FNT WHILE STRUGGLING TO REACH THE 70S
FURTHER N. TRENDED TWD THE WARMER MOS S OF THE FNT AND COOLER TO
THE N.
UNCERTAINTY REMAINS FOR PRECIP CHANCES TONIGHT. EXPECT PRECIP TO
DEVELOP AHEAD OF THE DEVELOPING SFC LOW ACROSS ERN KS THIS
AFTERNOON. THESE TSRA SHUD WEAKEN AS THE LOW APPROACHES THE
CWA...BUT BELIEVE THE NRN THIRD OF THE CWA WILL SEE TSRA TONIGHT.
STORMS MAY DEVELOP FURTHER S ALONG THE CDFNT AS IT MOVES THRU THE
REGION CLOSER TO SUNRISE FRI. CHANCES FOR THIS ARE LOWER AND JUST
HAVE LOW CHANCE POPS FOR NOW AS IS THERE IS ALSO A GREAT DEAL OF
UNCERTAINTY REGARDING TIMING OF THE FNT.
TILLY
&&
.LONG TERM...
ISSUED AT 328 AM CDT THU MAR 29 2012
(FRIDAY-WEDNESDAY)
KEPT POPS GOING FRI ALONG THE CDFNT MENTIONED ABOVE. AFTER THIS
SYSTEM MOVES OUT OF THE AREA...DRY CONDITIONS ARE FORECAST THRU
THE WEEKEND. IS SOME QUESTION ABOUT CHANCES FOR TSRA LATE SAT
NIGHT INTO SUN MORNING WITH RETURN FLOW SETUP AND DECENT LLJ OVER
THE AREA. HOWEVER...CHANCES ARE TOO LOW TO MENTION ATTM.
AFTER A BRIEF COOLER PERIOD EXPECTED ON FRI...CONTINUED A WARM
TREND FOR SAT WITH SLY FLOW RETURNING TO THE AREA.
FOR THE EXTD...PERIOD...AND APRIL...EXPECTED TO BEGIN WITH A VERY
WARM DAY. SOME GUIDANCE SUGGESTS TEMPS MAY BE NEAR RECORD HIGHS IN
THE UPPER 80S ACROSS MUCH OF THE REGION. HAVE NOT TRENDED THAT
WARM YET...BUT MDLS CONTINUE TO SUGGEST A VERY WARM PATTERN WITH
H85 TEMPS IN THE 16C TO 20C RANGE. THOUGHT A FORECAST GOING OVER
25 DEGREES ABOVE SEASONAL AVG WAS A GOOD START.
ECMWF/GFS HAVE COME INTO FAIRLY GOOD AGREEMENT FOR MON. WITH THE
GEM AS AN OUTLIER...HAVE TRENDED AWAY FROM THIS SOLN. WITH THE
ECMWF NOW ALSO SUGGESTING PRECIP ALONG THE CDFNT AS IT PUSHES THRU
THE REGION...HAVE RAISED POPS INTO THE CHANCE RANGE FOR MON INTO
MON NIGHT.
TRENDED TWD A GUIDANCE BLEND FOR TUES WITH A BRIEF PERIOD OF TEMPS
NEAR AVG BEFORE SW FLOW SETS UP AGAIN BY WED.
TILLY
&&
.AVIATION...
ISSUED AT 1250 PM CDT THU MAR 29 2012
COMPLEX OF THUNDERSTORMS OVER NORTHWEST MISSOURI IS MOVING SLOWLY
EASTWARD AND CURRENTLY BELIEVE THAT IT WILL STAY NORTH OF KCOU AND
THE ST. METRO ARE TAF SITES. IF THE SYSTEM DOES TURN SLIGHTLY
SOUTHEASTWARD AND MAINTAINS ITS STRENGTH...THEN AMENDMENTS WILL BE
REQUIRED FOR ALL OF THESE SITES TO INCLUDE TEMPO FOR TSRA. EXPECT
THERE WILL BE A PERIOD OF DRY WEATHER THIS EVENING BEFORE A COLD
FRONT APPROACHES THE AREA FROM THE WEST LATE TONIGHT AND EARLY
FRIDAY. HAVE ADDED VCSH WITH A CB GROUP TO ACCOMMODATE THE
POTENTIAL FOR SCATTERED THUNDERSTORMS MOVING ALONG THE FRONT.
WINDS IN THE ST. METRO AREA ARE CURRENTLY BEING INFLUENCED BY
DECAYING THUNDERSTORMS...BUT SHOULD TURN EASTERLY AND SLOWLY BACK
THROUGH THE TAF PERIOD.
SPECIFICS FOR KSTL...HAVE GONE INITIALLY WITH A DRY CONDITIONS
FOR THIS AFTERNOON. IF THE THUNDERSTORM COMPLEX TO THE NORTHWEST
OF KCOU HOLDS TOGETHER AND MOVES SLIGHTLY MORE SOUTHEAST...THEN IT
MAY AFFECT THE EVENING RUSH HOUR AFTER 23Z. OTHERWISE EXPECT
MAINLY DRY AND VFR CONDITIONS...THOUGH SCATTERED THUNDERSTORMS MAY
DEVELOP AHEAD OF A COLD FRONT THAT WILL MOVE THROUGH THE TERMINAL
LATE ON FRIDAY MORNING.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1203 AM CDT THU MAR 29 2012
.UPDATE...
ISSUED AT 933 PM CDT WED MAR 28 2012
ISOLATED SHOWERS AND STORMS CONTINUE TO DEVELOP ALONG FRONTAL
BOUNDARY WHICH EXTENDS FROM JUST S OF MCI SE THROUGH FAM. MORE
ORGANIZED CONVECTION WAS ACROSS ERN KS INTO W CNTRL MO JUST E OF
A SLY LOW LEVEL JET AXIS AND JUST AHEAD OF A WEAK SHORTWAVE OVER
SRN NEBRASKA AND NRN KANSAS. THIS ACTIVITY SHOULD SHIFT EWD TGT
WITH THE STRONGER STORMS IMPACTING CNTRL MO...AND WEAKER SHOWERS
AND STORMS FURTHER N MOVING EWD INTO NERN MO. AS THIS ACTIVITY
SPREADS EWD LATE TGT IT SHOULD WEAKEN AS IT GETS INTO ERN MO AND
ENCOUNTERS LESS LOW LEVEL MOISTURE AND INSTABILITY. WILL CONTINUE
WITH THE HIGHEST POPS OVER CNTRL MO INTO SERN MO NEAR THE
FRONT...WITH LITTLE IF ANY POPS OVER THE IL COUNTIES OF OUR
FORECAST AREA WITH A SFC RIDGE EXTENDING SWD THROUGH WI AND IL.
GKS
&&
.SHORT TERM...
ISSUED AT 320 PM CDT WED MAR 28 2012
(TONIGHT THROUGH FRIDAY)
PRIMARY CONCERN IN THE SHORT TERM IS POPS TONIGHT THROUGH FRIDAY.
QUASI-STATIONARY FRONT EXTENDS FROM NEAR FARMINGTON WEST-NORTHWEST
BETWEEN COLUMBIA AND SEDALIA TO NEAR TOPEKA. UNSTABLE AIRMASS IS
EVIDENT IN CUMULUS FIELD SOUTH OF THE FRONT AND SHOWERS ARE ALREADY
BREAKING OUT SOUTH OF THE ST LOUIS METRO AREA. EXPECT WIDELY
SCATTERED SHOWERS TO CONTINUE ALONG AND SOUTH OF THE FRONT THIS
AFTERNOON AND INTO THIS EVENING...BUT THE MAIN SHOW WILL DEVELOP
ACROSS SOUTHERN NEBRASKA AND NORTHERN KANSAS WHERE INSTABILITY AND
FORCING IS GREATEST. SOME QUESTION AS TO WHAT CONVECTIVE MODE THE
STORMS WILL ULTIMATELY TAKE. INSTABILITY AND SHEAR IS GREAT ENOUGH
FOR SOME ORGANIZATION...AND THE HRRR HAS ALTERNATELY BEEN DEVELOPING
DISCRETE SUPERCELLS...BOW ECHOS...AND OCCASIONALLY MULTICELL
CLUSTERS. THINK EITHER THE MULTICELL CLUSTER OR BOW ECHO IS MOST
LIKELY. FORWARD PROPAGATING CORFIDI VECTORS WOULD MOVE ANY MCS THAT
DEVELOPS EAST-SOUTHEAST INTO WESTERN MISSOURI. STORMS SHOULD RUN
OUT OF INSTABILITY AS THEY APPROACH CENTRAL MISSOURI AND SHOULD BE
IN THE WANING PHASE. WILL CONTINUE THE CHANCE FOR WIDELY SCATTERED
THUNDERSTORMS ON THURSDAY AS FRONT LIFTS BACK ACROSS THE AREA...THEN
ANOTHER SHOT OF PRECIP THURSDAY NIGHT AS A SHORTWAVE RIPPLES ACROSS
IOWA AND MISSOURI ACCOMPANIED BY ANOTHER WEAK COLD FRONT.
CARNEY
&&
.LONG TERM...
ISSUED AT 320 PM CDT WED MAR 28 2012
(SATURDAY THROUGH WEDNESDAY)
PRIMARY CONCERN IN THE SHORT TERM IS POPS TONIGHT THROUGH FRIDAY.
QUASI-STATIONARY FRONT EXTENDS FROM NEAR FARMINGTON WEST-NORTHWEST
BETWEEN COLUMBIA AND SEDALIA TO NEAR TOPEKA. UNSTABLE AIRMASS IS
EVIDENT IN CUMULUS FIELD SOUTH OF THE FRONT AND SHOWERS ARE ALREADY
BREAKING OUT SOUTH OF THE ST LOUIS METRO AREA. EXPECT WIDELY
SCATTERED SHOWERS TO CONTINUE ALONG AND SOUTH OF THE FRONT THIS
AFTERNOON AND INTO THIS EVENING...BUT THE MAIN SHOW WILL DEVELOP
ACROSS SOUTHERN NEBRASKA AND NORTHERN KANSAS WHERE INSTABILITY AND
FORCING IS GREATEST. SOME QUESTION AS TO WHAT CONVECTIVE MODE THE
STORMS WILL ULTIMATELY TAKE. INSTABILITY AND SHEAR IS GREAT ENOUGH
FOR SOME ORGANIZATION...AND THE HRRR HAS ALTERNATELY BEEN DEVELOPING
DISCRETE SUPERCELLS...BOW ECHOS...AND OCCASIONALLY MULTICELL
CLUSTERS. THINK EITHER THE MULTICELL CLUSTER OR BOW ECHO IS MOST
LIKELY. FORWARD PROPAGATING CORFIDI VECTORS WOULD MOVE ANY MCS THAT
DEVELOPS EAST-SOUTHEAST INTO WESTERN MISSOURI. STORMS SHOULD RUN
OUT OF INSTABILITY AS THEY APPROACH CENTRAL MISSOURI AND SHOULD BE
IN THE WANING PHASE. WILL CONTINUE THE CHANCE FOR WIDELY SCATTERED
THUNDERSTORMS ON THURSDAY AS FRONT LIFTS BACK ACROSS THE AREA...THEN
ANOTHER SHOT OF PRECIP THURSDAY NIGHT AS A SHORTWAVE RIPPLES ACROSS
IOWA AND MISSOURI ACCOMPANIED BY ANOTHER WEAK COLD FRONT.
THE FRONT WILL CONTINUE SOUTH INTO THE LOWER MISSISSIPPI VALLEY BY
SATURDAY BRINGING AN END TO THE PRECIP CHANCES FOR THE WEEKEND.
TEMPERATURES SHOULD REMAIN ABOVE NORMAL IN THE UPPER 70S TO THE
LOWER 80S. A SHARP TROF WILL DEVELOP OVER THE PLAINS SUNDAY NIGHT
INTO MONDAY WITH SURFACE CYCLOGENESIS TAKING PLACE OVER THE
NORTHEAST PLAINS OR THE UPPER MIDWEST. SOME TIMING DIFFERENCES ON
MEDIUM RANGE MODELS IS MAKING PRECIP TIMING DIFFICULT...BUT EXPECT
SHOWERS AND THUNDERSTORMS TO BE IN THE AREA MONDAY AND MONDAY
NIGHT...POSSIBLY LINGERING INTO TUESDAY. EXPECTING TEMPERATURES
BEHIND THE FRONT TO BE MORE SEASONABLE IN THE 60S AND LOWER 70S.
CARNEY
&&
.AVIATION...
ISSUED AT 1142 PM CDT WED MAR 28 2012
SHOWERS AND THUNDERSTORMS HAVE BOTH MOVED AND DEVELOPED FURTHER
EAST THAN EXPECTED THIS EVENING AND WERE SCATTERED ACROSS CENTRAL
MO TO AROUND 40-50 MILES WEST OF ST LOUIS. A BAND OF STRONGER AND
BETTER ORGANIZED THUNDERSTORMS WAS LOCATED THROUGH WEST CENTRAL
MO. ALL OF THIS ACTIVITY WAS OCCURING ALONG AND NORTH OF A
STATIONARY FRONT LOCATED ACORSS SOUTHERN MISSOURI AND SOUTHERN
ILLINOIS. THE SCATTERED ACTIVITY SHOULD GRADUALLY BE ENCOUNTERING
A MORE STABLE AIR MASS AS IT MOVES EAST SOUTHEAST. I HAVE ADDED A
-SHRA OR VCSH OVERNIGHT FOR THE ST LOUIS AREA TAFS GIVEN THE
SCATTERED COVERAGE AND UNCERTAINTY ABOUT A MORE DIRECT IMPACT AT
THE TERMINALS. KCOU HAS ALREADY SEEN SOME LIGHT RAIN AND THUNDER
AND THEY APPEAR TO BE IN LINE FOR ANOTHER STRONGER ROUND
OVERNIGHT. I THINK SOME OF THE ACTIVITY OVER NORTHWEST MO MAY HOLD
TOGETHER AS IT MOVES EAST AND IMPACT KUIN JUST AFTER DAYBREAK. I
THINK ALL THE PRECIPITATION WILL HAVE MOVED TO THE EAST BY MID
MORNING IF NOT SOONER WITH VFR CONDITIONS DOMINATING THE REMAINDER
OF THE TAF PERIOD.
SPECIFICS FOR KSTL...
SHOWERS AND THUNDERSTORMS HAVE BOTH MOVED AND DEVELOPED FURTHER
EAST THAN EXPECTED THIS EVENING AND WERE SCATTERED ACROSS CENTRAL
MO TO AROUND 40-50 MILES WEST OF ST LOUIS. THIS SCATTERED
ACTIVITY SHOULD GRADUALLY BE ENCOUNTERING A MORE STABLE AIR MASS
AS IT MOVES EAST SOUTHEAST. I HAVE ADDED -SHRA FOR A PERIOD OVERNIGHT
GIVEN THE SCATTERED COVERAGE AND UNCERTAINTY ABOUT A MORE DIRECT
IMPACT AT THE TERMINALS. I THINK ALL THE PRECIPITATION WILL HAVE
MOVED TO THE EAST OR DISSIPATED BY DAYBREAK IF NOT SOONER WITH VFR
CONDITIONS DOMINATING THE REMAINDER OF THE TAF PERIOD.
GLASS
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS HASTINGS NE
754 PM CDT FRI MAR 30 2012
.UPDATE...HAVE GONE AHEAD AND UPDATED THE FORECAST IN ANTICIPATION
OF THE ONE FINAL STORM IN MITCHELL COUNTY FINALLY DIEING OFF BETWEEN
8 AND 9 PM WITH SUNDOWN. ENTERTAINING SOME THOUGHT OF A LATE NIGHT
OR NEAR DAWN ISOLATED SHOWER IN NORTHERN CWFA WITH DECENT WARM
ADVECTION. ALL FORECASTS DRY...BUT WRF AND HRRR BOTH HAVE SOME
IDEA OF THIS POSSIBILITY.
&&
.PREV DISCUSSION... /ISSUED 614 PM CDT FRI MAR 30 2012/
UPDATE...ADDED A FEW THUNDERSTORMS THROUGH ABOUT 8 PM ALONG A
WEAKISH SURFACE TROUGH WITH A VERY NARROW SURGE OF MOISTURE INTO
THE SOUTHEAST CWFA. AN ISOLATED STRONG STORM IS POSSIBLE.
ELSEWHERE ITS DRY AND NICE.
AVIATION...VFR CONDITIONS ARE FORECAST FOR THE TAF PERIOD. WINDS
WILL DIE OFF EARLY...BUT PICK UP AGAIN DURING THE DAY SATURDAY AS
MIXING IS GOOD WITH HIGH TEMPERATURES WELL INTO THE 80S. WINDS
WILL TURN MORE SOUTHWESTERLY WITH GUSTS TO 20KTS AT TIMES. NO
VISIBILITY RESTRICTIONS ARE EXPECTED. ISOLATED THUNDERSTORMS IN
THE AREA THIS EVENING WILL BE SOUTHEAST OF THE KGRI AREA.
PREV DISCUSSION... /ISSUED 358 PM CDT FRI MAR 30 2012/
SHORT TERM...TONIGHT AND TOMORROW.
AS THE SHORT WAVE TROUGH AXIS PUSHES ACROSS THE CENTRAL PLAINS...A
FEW RAIN SHOWERS HAVE POPPED UP ACROSS NORTHEAST NEBRASKA. A FEW OF
THESE COULD BECOME THUNDERSTORMS AND MOVE ACROSS NORTHEAST PORTIONS
OF THE FORECAST AREA.
UPPER LEVEL ANALYSIS INDICATES MOSTLY ZONAL FLOW ACROSS THE CONUS
WITH A SHORT WAVE TROUGH ACROSS THE CENTRAL PLAINS. THE CORE OF THE
UPPER LEVEL JET REMAINS STRONGEST OFF THE WEST COAST...ALTHOUGH A
SECONDARY JET AXIS CONTINUES TO PUSH OFF THE EAST COAST. AT 500
MB...ZONAL FLOW CONTINUES ACROSS THE CONUS...WHILE A STRONG LOW
PRESSURE SYSTEM SPINS ACROSS CANADA. AT THE MID LEVELS...ZONAL FLOW
IS PREDOMINANT...ALTHOUGH THERE REMAINS A FEW SHORT WAVE TROUGHS
ACROSS THE REGION. ONE TROUGH REMAINS CENTERED OFF THE EAST OF THE
PLAINS WHILE A SECONDARY TROUGH BEGAN MOVING ACROSS THE CENTRAL
PLAINS TODAY. AT THE SURFACE A WEAK HIGH PRESSURE SYSTEM PASSED JUST
TO THE SOUTH OF THE REGION WHILE A WEAK LOW PRESSURE SYSTEM MOVED
ACROSS THE NORTHERN PLAINS FROM THE FRONT RANGE OF THE ROCKIES.
UPPER LEVEL RIDGING WILL BUILD ACROSS THE PLAINS ON SATURDAY...WHILE
THE MAIN CORE OF THE JET WRAPS AROUND THE TOP OF THE RIDGE. SKIES
ARE EXPECTED TO REMAIN PARTLY CLOUDY AS THE UPPER LEVEL JET NOSES
ACROSS THE REGION SATURDAY MORNING...AND WITH THE DEVELOPMENT OF
CUMULUS DURING THE AFTERNOON. 850 TEMPERATURES ARE EXPECTED TO SOAR
ACROSS THE REGION TO NEAR 20 DEGREES...COMBINED WITH STRONG BOUNDARY
LAYER MIXING...HIGH TEMPERATURES COULD EASILY REACH RECORD HIGHS
NEAR 90 DURING THE AFTERNOON TOMORROW. FIRE WEATHER THREATS WILL
REMAIN A CONCERN SATURDAY AFTERNOON AS RELATIVE HUMIDITY VALUES ARE
ALREADY FORECAST TO BE NEAR OR SLIGHTLY BELOW 20 PERCENT ACROSS THE
NORTHWEST. ALTHOUGH DEWPOINTS ARE QUITE LOW ALREADY...MODEL
SOUNDINGS INDICATE BOUNDARY LAYER MIXING TO NEAR 700 MB...THUS
REDUCING DEWPOINTS EVEN FARTHER. DECIDED NOT TO GO WITH ANY FIRE
WATCH AT THIS POINT...AS STRONGEST WINDS WILL REMAIN JUST UNDER
CRITERIA AND ACROSS THE NORTHEAST...VERSUS LOW RH VALUES ACROSS THE
NORTHWEST.
LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
FOR TUESDAY AND BEYOND...USED A BLEND OF 00Z OPERATIONAL ECMWF AND
ITS ENSEMBLES...TRANSITIONING TO ENSEMBLES TOWARD THE OUTER PERIODS
TO HELP TAKE A MIDDLE GROUND FOR MITIGATING DISCREPANCIES WITHIN THE
SYNOPTIC SCALE.
A PROMINENT UPPER LEVEL RIDGE WILL BE IN PLACE FOR SATURDAY NIGHT AS
A TROUGH MOVES ONTO THE WEST COAST...WITH A MODEST LOW-LEVEL JET
DEVELOPING OVER THE PLAINS. PROGGED SOUNDINGS INDICATE DRY CONDITIONS
WITH WARM AIR ADVECTION KEEPING LOW TEMPERATURES IN THE 50S.
SOUTH WIND WILL BECOME A BIT MORE BREEZY ON SUNDAY AS THE SURFACE
PRESSURE GRADIENT INCREASES AHEAD OF AN APPROACHING COLD FRONT. WITH
SOME INCREASED MOISTURE RETURN AT THE SURFACE...HIGHS WILL TOP OUT
IN THE MID 80S...MUCH ABOVE NORMAL BUT A TAD COOLER THAN HIGHS ON
SATURDAY. AS THE TROUGH MOVES EAST THROUGH THE ROCKY
MOUNTAINS...MODELS POINT TOWARD A CLOSED LOW DEVELOPING WITHIN THE
TROUGH BY SUNDAY NIGHT.
THE COLD FRONT WILL FINALLY BLOW THROUGH LATE SUNDAY NIGHT/EARLY
MONDAY MORNING...LATE ENOUGH FOR HIGHS TO BE QUITE WARM IN THE 50S
FOR MOST LOCATIONS. THERE IS STILL SOME UNCERTAINTY TO TIMING OF
THIS FRONT AND IT COULD ARRIVE A LITTLE LATER...GIVEN LATEST TRENDS.
THIS APPEARS TO BE A DRY COLD FRONT PASSAGE WITH NEARLY BONE DRY
MID-LEVELS BUT THERE COULD BE ENOUGH MOISTURE AND INSTABILITY TO
GIVE US A SMALL CHANCE OF SHOWERS AND PERHAPS THUNDERSTORMS WITH
SOME POSSIBLE INSTABILITY AHEAD OF THE FRONT. IMPRESSIVE HEIGHT RISES
WILL PROVIDE A STIFF NORTH WIND WITH SIGNIFICANTLY COLDER HIGHS IN
THE 60S...BUT STILL ABOVE NORMAL FOR THIS TIME OF YEAR. THERE COULD
BE A SMALL CHANCE OF ELEVATED POST-FRONTAL PRECIPITATION FOR MONDAY
INTO TUESDAY FOR PARTS OF THE CWA. LEFT SMALL CHANCES OF SHOWERS FOR
MONDAY NIGHT AS THE NORTHERN STREAM WAVE PASSES AND SOME LOWER
CHANCES IN THE SOUTH INTO TUESDAY...AS THEY COULD BE CLOSE ENOUGH TO
STILL BE UNDER THE INFLUENCE OF THE CLOSE LOW TO THE SOUTH.
INSTABILITY SHOULD BE LIMITED BY THEN.
MODELS DIFFER WITH THE TRACK OF THE CLOSED LOW FOR THE LAST FEW DAYS
OF THE EXTENDED FORECAST AFTER THE LOW SPILLS OUT INTO THE SOUTHERN
PLAINS BY AS THE ECMWF POINTS THIS LOW EAST ACROSS THE GULF
COAST...WHILE THE GFS SWINGS THE LOW A BIT FARTHER NORTHEAST INTO
THE MID-SOUTH. BOTH SOLUTIONS SHOULD KEEP CHANCES OF PRECIPITATION
SOUTH OF THE CWA.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
659 PM CDT FRI MAR 30 2012
.AVIATION...
00Z TAFS FOR KOMA...KLNK...KOFK.
SOME ISOLATED SHOWERS AND THUNDERSTORMS WILL AFFFECT KOMA AND
KLNK FOR A WHILE THIS EVENING...BUT GENERALLY VFR CONDITIONS
SHOULD PREVAIL.
MILLER
&&
.PREV DISCUSSION... /ISSUED 314 PM CDT FRI MAR 30 2012/
SHORT TERM...TONIGHT THROUGH MONDAY.
SEVERAL PERIODS OF ISOLD/SMALL POP CONVECTION CHANCES DOT SHORT
TERM FORECAST LANDSCAPE OTHERWISE TEMPERATURES ARE THE PRIMARY CONCERN.
FIRST SMALL PRECIP CHANCE IS EARLY THIS EVENING AS UPPER SHORT
WAVE ENERGY PUSHING TOWARD MO RIVER PER AFTERNOON STLT IMAGERY
FOCUSES ON CONVERGENT BOUNDARY WHICH AT 19Z STRETCHED FROM YKN-
TQE-OMA WITH SECOND CONVERGENT AREA APPROACHING LNK AND OLU.
SELECTIVE MODELS...I.E. HRRR+4KM WRF HAVE GENERATED SMALL QPF CLUSTER
WHICH PUSHES INTO SWRN IA BEFORE WEAKENING FAIRLY QUICKLY WITH
LOSS OF HEATING. MEANWHILE RUC KEPT MID LAYER PRETTY DRY/WELL
MIXED CAP AND GFS NOT OVERLY SUPPORTIVE EITHER. WILL EXTEND SMALL
POPS ERN ZONES EARLY THIS EVENING...HOWEVER...DUE TO CONVERGENT
CU AND OCNL WEAK CELLS THAT HAD CONTD TO DEVELOP ON RADAR IN
19-20Z PERIOD.
OTHERWISE FLAT UPPER RIDGING SPREADING ACROSS PLAINS ON SATURDAY
WILL BRING EVEN WARMER READINGS TO AREA WITH NEAR RECORD HIGHS
LIKELY AT OFK/OMA AND LNK. DID NOT INCLUDE LATE AFTERNOON POPS AT
THIS TIME NEAR H85 THERMAL AXIS NEAR OR N OF OMA AND POINTS
EWD...BUT CONVECTIVE TEMPERATURES COULD BE REACHED PER NAM
FORECAST SOUNDINGS. AREA WILL HAVE TO BE MONITORED...BUT LEFT OUT
DUE TO AREA APPEARS WILL EXTEND IN GENERAL UPPER RIDGE AREA.
UPPER RIDGE AMPS/SHIFTS EAST A LITTLE SUNDAY SPREADING EVEN
WARMER H85 TEMPS OVER AREA. RECORD HIGHS AGAIN APPROACHED MANY
LOCATIONS AS IT APPEARS MOST HIGHS SHOULD BE A FEW DEGREES WARMER
THAN THOSE EXPECTED ON SATURDAY.
LEFT IN SMALL POPS WITH FRONT ON MONDAY ALTHOUGH THERE WAS LITTLE
UPPER SUPPORT WITH FRONT PUSHING INTO NEGATIVELY TILTED UPPER
RIDGE AS ENERGY SPLITS. HOWEVER...WITH VERY WARM TEMPERATURES
AHEAD OF THIS STRONGER COLD FRONT...AND DELAYED TIMING A BIT...DID
BOOST MAX TEMPS A CATEGORY OR SO SERN 1/2-2/3RDS OF THE AREA.
LONG TERM...MONDAY NIGHT THROUGH FRIDAY.
FOCUS TURNS TO HOW FAR NORTH UPPER LOW WILL DRIFT FOR POSSIBLE
PRECIP CHANCES...IF IT LIFTS FAR ENOUGH N...OR FOR POTENTIAL
FROST/ISOLD FREEZING TEMPERATURES IF PATTERN DEVELOPS INTO A
STALLED REX-LIKE BLOCK WITH UPPER LOW FARTHER SOUTH. ALTHOUGH
LOWERED A FEW LOW TEMPERATURES INTO UPPER 30S-40ISH WED AM DID NOT
STRAY TOO FAR FROM MODEL BLEND WITH OTHER LOW TEMPS AS TOO MANY
UNCERTAINTIES PERSIST. DID ALSO LOWER MAX TEMPS A LITTLE IN WED-
THU PERIOD AND SPREAD POPS A LITTLE FARTHER NW MON NIGHT INTO TUE.
HOWEVER...ENTIRE PERIOD WILL LIKELY SEE CHANGES...AND AT LEAST
MODERATE ONES...AS CONFIDENCE WAS LOW WITH HOW PATTERN WILL
DEVELOP.
AVIATION...
18Z TAFS FOR KOMA...KLNK AND KOFK.
VFR CONDITIONS SHOULD PREVAIL THROUGH THE TAF PERIOD. A MID LEVEL
SHORTWAVE IS MOVING THROUGH EASTERN NEBRASKA THIS AFTERNOON. THIS
COULD SPARK A FEW THUNDERSTORMS...MAINLY BEFORE 7 PM.
PEARSON
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS HASTINGS NE
342 PM CDT THU MAR 29 2012
.SHORT TERM...THROUGH FRIDAY. MAIN FORECAST CONCERN WILL BE
THUNDERSTORMS THIS AFTERNOON.
STRATUS HAS BEEN PERSISTENT ACROSS THE CENTRAL PART OF THE
FORECAST AREA MUCH OF THE DAY...WHILE THE NORTH AND SOUTH HAVE HAD
SOME CLEARING. THE LATEST TREND IN THE RADAR HAS SOME WEAK SHOWERY
TYPE PRECIPITATION FORMING UNDER THE STRATUS. THUNDERSTORMS THAT
HAD DEVELOPED IN NORTH CENTRAL NEBRASKA EARLIER HAVE DECREASED TO
WEAK SHOWERS. SURFACE ANALYSIS SHOWS THE SURFACE LOW IN CENTRAL
KANSAS WITH A BOUNDARY EXTENDING TO THE NORTH THROUGH THE FORECAST
AREA. THE BOUNDARY IS MORE OF A BROAD TROUGH THAN A REAL COLD
FRONT. WINDS SWITCH FROM EASTERLY TO NORTHERLY AS THE TROUGH GOES
PAST...BUT THE DRIER AIR AND WIND INCREASE IS FURTHER TO THE WEST.
THE UPPER LEVEL WAVE AND SURFACE BOUNDARY WILL CONTINUE TO MOVE
TO THE EAST. THEY WILL PUSH THROUGH THE EASTERN HALF OF THE
FORECAST AREA DURING THE REMAINDER OF THE AFTERNOON AND SHOULD BE
TO THE EAST BY EVENING. THE MODELS CONTINUE TO HAVE SOME SHOWERS
AND THUNDERSTORMS DEVELOP LATE THIS AFTERNOON AS THE FRONT MOVES
THROUGH THE AREA. THE 00Z 4KM WRF AND THE HRRR DEVELOP SOME
SHOWERS AND THUNDERSTORMS ALONG AND JUST BEHIND THE FRONT LATE
THIS AFTERNOON. WILL KEEP CHANCES FOR THUNDERSTORMS ACROSS THE
AREA...BUT THE BEST CHANCE WILL BE IN THE NORTHEAST WHERE THE
UPPER WAVE IS STRONGEST. MUCAPE IS 1500 TO 2000 J/KG SO THERE
COULD BE SOME STRONG TO SEVERE THUNDERSTORMS.
ONCE THE BOUNDARY MOVES TO THE EAST THE CHANCES FOR THUNDERSTORMS
DROPS OFF AND HAVE KEPT THE FORECAST DRY FOR THIS EVENING. THE
PRECIPITATION SHOULD BE TO THE EAST OF THE FORECAST AREA BY EVENING.
BY LATE TONIGHT A SURFACE HIGH PRESSURE SYSTEM BUILDS INTO THE AREA
AND SKIES BECOME MOSTLY CLEAR TO PARTLY CLOUDY. ON FRIDAY THERE IS
WARM ADVECTION SO THE TEMPERATURES SHOULD WARM UP FROM TODAY.
.LONG TERM...SATURDAY THROUGH THURSDAY.
FOR MUCH OF THE MID TERM PERIOD...SATURDAY AND SUNDAY...THE
CENTRAL PLAINS REMAIN CENTERED UNDER A WEAK RIDGE...WITH FAIRLY
ZONAL FLOW ACROSS THE REGION. NO PRECIPITATION IS EXPECTED THROUGH
THE MID TERM PERIOD. DECIDED TO BUMP UP TEMPERATURES SLIGHTLY BOTH
SATURDAY AND SUNDAY AS GUIDANCE IS A FEW DEGREES IN HIGHER IN BOTH
THE NAM AND THE GFS. 850 TEMPERATURES NEAR 20 DEGREES CELSIUS BOTH
DAYS SHOULD WARM UP THE AREA QUITE NICELY.
BEGINNING THE EXTENDED PERIOD SUNDAY NIGHT...AN UPPER LEVEL
TROUGH CONTINUES TO PUSH OFF THE WEST COAST TOWARDS THE COLORADO
ROCKIES. THE GFS IS DEEPER THAN THE NAM SOLUTION WITH THIS
TROUGH...WHILE BOTH MODELS SUGGEST SURFACE LOW PRESSURE STRETCHING
FROM THE WESTERN PORTION OF THE PLAINS INTO CANADA SUNDAY NIGHT.
AS THE PRESSURE SYSTEMS PUSH THROUGH THE REGION SUNDAY NIGHT INTO
MONDAY MORNING...BOTH MODELS SUGGEST THE POSSIBILITY FOR
THUNDERSTORM CHANCES OVERNIGHT AHEAD OF THE SURFACE BOUNDARY. THE
EC REMAINS THE FASTER OF THE TWO SOLUTIONS WITH THE FRONT
COMPLETELY THROUGH THE FORECAST AREA BY 12Z...WHILE THE GFS PUSHES
THE FRONT ABOUT HALFWAY THROUGH BY 12Z. THAT BEING SAID...BOTH
MODELS ARE SUGGESTING A VERY TIGHT PRESSURE GRADIENT BEHIND THE
FRONT AND PRESSURE RISES OF 15 TO 20 MB ACROSS THE FORECAST AREA.
THE MAIN CONCERN WILL BE WITH THE TIMING OF THE INCREASED WINDS
BEHIND THE FRONT...WHILE THE EC INCREASES WINDS BY THE 6Z TO 12Z
TIME RANGE...THE GFS LAGS A BIT BEHIND AND INCREASES WINDS TOWARDS
THE MORNING AND AFTERNOON HOURS ON MONDAY. SUSTAINED NORTHWEST
WINDS NEAR 25 TO 30 MILES PER HOUR WITH WIND GUSTS NEAR 30 TO 35
MILES PER HOUR CAN BE EXPECTED BEHIND THE FRONT. DRY AIR BEHIND
THE FRONT WILL HELP REDUCE DEWPOINTS ACROSS THE REGION...IN
COMBINATION WITH HIGHER WINDS ON MONDAY...RELATIVE HUMIDITY VALUES
WILL NEED TO BE WATCHED AS THEY ARE CURRENTLY FORECAST TO BE IN
THE LOWER 20S ACROSS THE WEST. SHOULD HIGH TEMPERATURES INCREASE
OR DEWPOINTS DECREASE JUST SLIGHTLY...FIRE WEATHER MAY BE A
CONCERN ON MONDAY AFTERNOON.
AS THE TROUGH TRIES TO PUSH OUT OF THE REGION MONDAY
EVENING...THE EC BEGINS TO BRING IN AN UPPER LEVEL RIDGE AND
SURFACE HIGH PRESSURE SYSTEM IMMEDIATELY FOLLOWING...WHILE THE GFS
TAKES A BIT SLOWER TO MOVE OUT AND PRODUCES A CUT OFF LOW AT THE
UPPER LEVELS AND A STRONGER SURFACE LOW ACROSS OKLAHOMA AND
ARKANSAS BEFORE PUSHING OUT OF THE REGION BY TUESDAY EVENING.
COOLER TEMPERATURES ARE EXPECTED ACROSS THE PLAINS BOTH MONDAY AND
TUESDAY WITH HIGHS IN THE 60S.
BOTH MODELS KEEP THE CENTRAL PLAINS UNDER AN UPPER LEVEL RIDGE
AND SURFACE HIGH THROUGH THE END OF THE LONG TERM WITH SOUTHERLY
WINDS AND HIGH TEMPERATURES IN THE LOW TO MID 70S WEDNESDAY AND
THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 1219 PM CDT THU MAR 29 2012/
AVIATION...18Z TAF. LOWER CLOUDS HAVE BEEN PERSISTING ACROSS THE
AREA BUT SHOULD START TO LIFT SOME THIS AFTERNOON. THUNDERSTORMS
ARE POSSIBLE THIS AFTERNOON AS A BROAD TROUGH OF LOW PRESSURE
MOVES THROUGH THE KGRI TERMINAL AREA. ONCE THE BOUNDARY MOVES TO
THE EAST THE CLOUDS WILL DIMINISH THIS EVENING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1127 PM CDT WED MAR 28 2012
.AVIATION...
06Z TAFS FOR KOMA...KLNK AND KOFK.
SOME CONVECTIVE POTENTIAL WILL EXIST THROUGH MUCH OF THE PERIOD
AT ALL THREE SITES. WARM FRONT LOCATED SOUTH OF THE AREA AT 06Z
WILL LIFT NORTHEAST TONIGHT IN ADVANCE A COLD FRONT MOVING INTO
THE AREA ON THURSDAY AFTER 18Z. ANOTHER ROUND OF CONVECTION
POSSIBLE WITH THE COLD FRONT BETWEEN 18Z AND 00Z.
&&
.PREV DISCUSSION... /ISSUED 1033 PM CDT WED MAR 28 2012/
DISCUSSION...
UPDATE THE FORECAST FOR TONIGHT TO DECREASE THE POPS ACROSS THE
NW CWA AND DELAYED THE ONSET OF THE LIKELY POPS INTO SW. OTHERWISE
THE GOING FORECAST IS IN GOOD SHAPE.
DISTINCT AND STRONG WARM FRONT AT 850 MB WAS RIGHT ALONG THE
KS/NEB BORDER THIS EVNG. THIS FNT WILL TRY AND LIFT NWD THROUGH
THE NIGHT AS THE LOW LEVEL JET INCREASES FROM KANSAS INTO SE NEB.
THIS INCREASE IN THE LOW LEVEL JET AND SUBSEQUENT INCREASE IN
MASS CONVERGENCE HAS BEEN RESPONSIBLE FOR THE INCREASE IN
CONVECTION NEAR THE THE BORDER WITH KS. LATEST RUC ANALYSIS INDCS
THAT THERE IS AROUND 1000 J/KG OF MUCAPE RIGHT ALONG THE BORDER
BUT RAPIDLY DROPS OFF FARTHER NORTH. THUS AS STORMS LIFT NWD INTO
THE AREA THEY CONT TO WEAKEN. THERE MAY BE A SLIGHT RISK FOR AN
ISOLATED LARGE HAIL /NEAR QUARTER SIZE/ ALONG THE BORDER...BUT
OTHERWISE THERE IS LITTLE SVR WX THREAT FARTHER NORTH. THE
INCREASE IN THE LOW LEVEL JET SHOULD FOCUS OVER SE NEB AND SW IA
AND THIS IS WHERE WE SHOULD SEE THE HIGHEST CONCENTRATE OF PRECIP.
SHOWERS AND ISO STORMS SHOULD LINGER INTO THU MRNG OVER SW IA. NO
ADDITIONAL UPDATES ARE PLANNED AT THE MOMENT.
BOUSTEAD
PREV DISCUSSION... /ISSUED 258 PM CDT WED MAR 28 2012/
DISCUSSION...
MAIN FORECAST PROBLEM TONIGHT WILL BE INCREASING CHANCES FOR CONVECTION
AS A WEAK IMPULSE EJECTING OFF THE HIGH PLAINS COMBINES WITH A NORTHWARD
ADVANCING WARM FRONT MOVING INTO THE REGION. ELEVATION CONVECTION
WAS ALREADY ONGOING ACROSS SOUTH CENTRAL NEBRASKA. BELIEVE THIS
WILL DEVELOP FURTHER EAST THROUGH THE EVENING ALONG THE NEBRASKA
AND KANSAS BORDER REGION...THUS HAVE INCREASED POPS IN THAT
REGION THROUGH THE EVENING. COORDINATED WITH SPC EARLIER THAT THE
SLIGHT RISK MAY NEED TO MOVED JUST SLIGHTLY NORTHWARD TO ACCOUNT
FOR SOME MARGINAL HAIL IN THAT AREA THIS EVENING. AS WE MOVE
TOWARD LATE EVENING AND OVERNIGHT...BELIEVE THAT THERE`S AT LEAST
A CHANCE OF ADDITIONAL ELEVATION CONVECTION FURTHER NORTH UP THE
MISSOURI RIVER...PUSHING SLOWLY EAST THROUGH DAYBREAK THURSDAY.
A FEW LINGERING SHOWERS OR ISOLATED STORMS MAY BE ONGOING EARLY
THURSDAY MORNING ALONG AND EAST OF THE MISSOURI RIVER...BUT MOST
OF EASTERN NEBRASKA MAY ACTUALLY BE DRY. BY MIDDAY THURSDAY...THE
WARM FRONT WILL PROBABLY BE LOCATED ALONG THE NE/KS BORDER REGION
AGAIN...WHILE A COLD FRONT ADVANCES FROM THE NORTHWEST. THE MAIN
SEVERE THREAT WILL BE ALONG THE WARM FRONT IN SOUTHEAST NEBRASKA
AND SOUTHWEST IOWA...BUT GIVEN SHEAR ALONG THE ADVANCING COLD
FRONT...WOULD EXPECT SOME HAIL POTENTIAL THERE AS WELL. PRECIP
CHANCES INCREASE NOTABLY THROUGH THE AFTERNOON THROUGH PEAK
HEATING. THERE STILL REMAINS SOME UNCERTAINTY HOW FAR NORTH THE
WARM FRONT WILL MOVE THOUGH. EVENING THUNDERSTORMS SHOULD CONTINUE
TO PUSH OUT OF HERE THROUGH MIDNIGHT TOMORROW NIGHT.
THEN WE WARM BACK UP FRIDAY AND SATURDAY AS RIDGING ALOFT BUILD
INTO THE AREA WITH DRY CONDITIONS THAT LINGER THROUGH SUNDAY WITH
HIGHS BACK INTO THE LOWER TO MID 80S. ANOTHER WAVE MOVES INTO THE
REGION SUNDAY NIGHT WITH AN ATTACHED COLD FRONT. THIS WILL BRING
ANOTHER CHANCE OF THUNDERSTORMS...AND POSSIBLY SOME LINGERING
SHOWERS ON MONDAY. MORE IMPORTANTLY...IT WILL BRING SHARPLY COOLER
TEMPERATURES AGAIN WITH HIGHS BACK IN THE LOWER TO MIDDLE 60S AND
LOWS IN THE UPPER 30S AND LOWER 40S...BUT DRY CONDITIONS.
DEWALD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
FOBERT
AREA FORECAST DISCUSSION
NWS ELKO NV
633 PM PDT FRI MAR 30 2012
.SYNOPSIS...STRONG GUSTY WINDS WILL IMPACT THE REGION SATURDAY
AHEAD OF A STRONG SURFACE COLD FRONT. BLOWING DUST AND ISOLATED
THUNDERSTORMS WILL DEVELOP AHEAD OF THE FRONT. SATURDAY NIGHT
TEMPERATURES WILL RAPIDLY DROP BEHIND THE FRONT WITH SCATTERED
SNOW SHOWERS EXPECTED ON SUNDAY. A WARMING TREND AND DRIER WEATHER
IS EXPECTED FOR THE BEGINNING OF NEXT WEEK.
&&
.UPDATE...WINDS HAVE DECREASED OVER HUMBOLDT COUNTY THIS EVENING
SO HAVE CANCELLED THE WIND ADVISORY. WINDS ARE STILL EXPECTED TO
INCREASE SIGNIFICANTLY SATURDAY MORNING FOR A HIGH WIND WARNING
OVER THE ENTIRE CWA. SEE PREVIOUS DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED AT 311 PM /
SHORT TERM...TONIGHT THROUGH MONDAY. CURRENT WATER VAPOR IMAGERY
AND RUC ANALYSIS SHOWS A STRONG PACIFIC NORTHWEST JET MAX OF
130KTS AHEAD OF A DIGGING PACIFIC 500MB TROUGH. THE UPPER LEVEL
JET WILL CONTINUE TO PROGRESS EASTWARD INTO THE GREAT BASIN
TONIGHT. STILL LOOKING LIKE AN IMPRESSIVE WIND EVENT DURING THE
DAY TOMORROW ACROSS ALL ZONES. ALL HIGH WIND INDICES ARE LOOKING
GOOD WITH 700/500MB WIND ANOMALIES OF +3 TO 4 STANDARD
DEVIATIONS...MAV GUIDANCE FOR ALL TAF LOCATIONS IS SHOWING SOLID
32-38KTS...MIXING HEIGHTS ARE FORECASTED TO REACH 550MB...AND A
993 SURFACE LOW OVER SOUTHERN IDAHO WILL HELP ENHANCE LOW LEVEL
NORTH/SOUTH CHANNELING OF WINDS. HAVE UPGRADED ALL ZONES TO A HIGH
WIND WARNING FROM THE ONGOING WATCH. WILL MOST LIKELY HAVE SOME
BLOWING DUST TOMORROW WITH THE PROLONGED WIDE SPREAD WINDS. IN
ADDITION THERE COULD BE A FEW ISOLATED STRIKES DURING THE
AFTERNOON HOURS ALONG THE ID/OR/NV BORDER.
SATURDAY NIGHT THE FRONT WILL PUSH THROUGH THE AREA...WITH A VERY
TIGHT TEMP GRADIENT BEHIND THE FRONT. SHOULD SEE 20-30 DEGREE
TEMPS DROPS IN JUST A FEW HOURS BEHIND THE FRONT. PRECIP IS STILL
TRENDING LIGHT BEHIND THE FRONT...SO KEPT QPF AND SNOW AMOUNTS ON
THE LOW SIDE. MOST AREA WILL ONLY SEE A FEW HUNDREDTHS OF LIQUID
WITH MAYBE A TRACE OF SNOW ABOVE 5500FT. THERE STILL COULD BE A
FEW INCHES ACROSS THE MOUNTAINS OF EASTERN NV BY DAYBREAK SUNDAY.
SUNDAY A COLD UPPER LEVEL 500MB TROUGH WILL BE CENTERED OVER THE
REGION...LEADING TO STEEP LOW LEVEL LAPSE RATES. CONVECTIVE SNOW
SHOWERS WILL CONTINUE THROUGH THE DAY...WITH A FEW ADDITIONAL
INCHES OF ACCUMULATIONS ACROSS THE MOUNTAINS...ONLY A DUSTING IS
EXPECTED ACROSS THE WARMER VALLEYS. WARMER IS RELATIVE AS HIGHS
ARE ONLY EXPECTED TO REACH THE LOW TO MID 40S ACROSS THE VALLEYS
WITH BELOW ZERO TEMPS IN THE MOUNTAINS. RIDGING QUICKLY RETURNS BY
MONDAY...BRINGING A NICE DAY WITH MOSTLY CLEAR SKIES AND TEMPS
REBOUNDING INTO THE LOW 50S ONCE AGAIN...AFTER A COLD START TO THE
DAY WITH LOWS IN THE LOW 20S.
LONG TERM...MONDAY NIGHT THROUGH NEXT THURSDAY. GFS AND EURO IN
GOOD AGREEMENT MONDAY NIGHT THROUGH LATE TUESDAY NIGHT WITH
INCREASING SOUTHWEST FLOW FROM APPROACHING LONG WAVE TROUGH OFFSHORE
IN THE PACNW. AFTER THAT...THE GFS BECOMES SLIGHTLY DEEPER AND
SLIGHTLY NEGATIVELY TILTED AND CLOSES OFF A LOW AND MOVES IT INTO
THE INTERIOR PACIFIC NW...TRAILING A VORT LOBE OVER THE GREAT BASIN.
THE EURO HOLD BACK THIS LOW WHILE CLOSING IT OFF BUT MORE
SHALLOW...AND POSITIVELY TILTING THE TRAILING TROF. HENCE IT BRINGS
IN THE COLD FRONT...HUMIDITY...AND PRECIP LATER. HAVE OPTED TO GOT
WITH THE FASTER GFS. THE DRY SOUTHWEST FLOW WILL KEEP THINGS DRY
THROUGH WEDNESDAY MORNING WHEN A LITTLE SHORT WAVE WILL CROSS
NORTHERN NEVADA AND PROVIDE VERY LOW CHANCE POPS ALONG THE IDAHO
BORDER WITH SLIGHT CHANCE POPS IN NORTHERN NEVADA WITH BARELY DOUBLE
DIGIT POPS IN CENTRAL AND EASTERN NEVADA. DRY SOUTH TO SOUTHWEST
WINDS WILL INCREASE IN SPEED IN ADVANCE OF THE WAVE APPROACHING
TUESDAY NIGHT/WEDNESDAY MORNING. TEMPS SHOULD BE COOLER THAN OUR
CURRENT ABOVE NORMAL PATTERN. MINS WILL BE LOWER WITH FEWER CLOUDS
AND LIGHTER WINDS. AS CLOSED GFS LOW MOVES NORTH OF THE GREAT BASIN
EXPECTING TRAILING LOW LEVEL TROUGH TO CROSS THE STATE AND INCREASE
SOUTH-SOUTHWEST WINDS IN ADVANCE. MIGHT POSSIBLY MEET ADVISORY
CRITERIA LATE WEDNESDAY AND EARLY THURSDAY. POPS...TEMPS...REMAIN
CONSTANT DURING THE WED-THURSDAY FRAME.
AVIATION...A PACIFIC FRONT IS APPROACHING THE NORTHERN GREAT BASIN
AND WINDS AND CLOUDS WILL INCREASE OVER NIGHT AND ESPECIALLY ON
SATURDAY. ISOLATED SHOWERS WILL OCCUR NEAR KWMC AND KEKO ON
SATURDAY. CIGS AND VSBYS WILL BE TECHNICALLY VFR AT ALL SITES BUT
MOUNTAIN TOPS WILL BE POTENTIALLY OBSCURED AT ALL SITES. WINDS WILL
INCREASE TO OVER 35 KNOTS AT ALL SITES SATURDAY AFTERNOON WITH OVER
45 KNOTS AT KEKO...AND OVER 50 KNOTS AT KELY AND KTPH.
FIRE WEATHER...AN INTENSE COLD FRONT WILL ENTER THE FIRE DISTRICT
SATURDAY AFTERNOON AND EXIT EARLY SUNDAY MORNING. MIN RH WILL
GENERALLY BE AROUND 15% AND WIND GUSTS COULD REACH TO AROUND 70
MPH AS THE FRONT MOVES THROUGH SATURDAY AFTERNOON AND EVENING.
FUELS CONTINUE TO APPEAR NON-CRITICAL. AFTER COLLABORATION WITH
SPC...WILL HAVE A SEE-TEXT BOX FOR NORTHERN NYE COUNTY. FIRE
MANAGERS ARE URGED TO USE EXTREME CAUTION AND REFRAIN FROM ALL
BURNING SATURDAY AFTERNOON AND EVENING.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING FROM 11 AM TO 11 PM PDT SATURDAY FOR EXTREME
EASTERN ELKO COUNTY...NORTHERN ELKO COUNTY...NORTHERN LANDER
COUNTY AND NORTHERN EUREKA COUNTY...NORTHERN NYE COUNTY...RUBY
MOUNTAINS/EAST HUMBOLDT RANGE...SOUTHERN LANDER COUNTY AND
SOUTHERN EUREKA COUNTY...SOUTHWEST AND SOUTH CENTRAL ELKO
COUNTY...WHITE PINE COUNTY.
HIGH WIND WARNING FROM 8 AM TO 11 PM PDT SATURDAY FOR HUMBOLDT
COUNTY.
&&
$$
87/95/98/98/99
AREA FORECAST DISCUSSION
NWS RALEIGH NC
326 AM EDT THU MAR 29 2012
.SYNOPSIS...
A DRY COLD FRONT WILL CROSS NC TODAY AND SETTLE INTO SC TONIGHT. THE
FRONT WILL RETURN NORTHWARD AS A WARM FRONT ON FRIDAY...IN ADVANCE
OF A LOW PRESSURE SYSTEM AND TRAILING COLD FRONT THAT WILL CROSS THE
MIDDLE ATLANTIC STATES FRIDAY NIGHT THROUGH SATURDAY NIGHT.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
AS OF 10 PM EDT WEDNESDAY...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH AN APPROACHING COLD FRONT
HAVE REMAINED GENERALLY TO THE NORTH OF THE AREA THIS EVENING.
HOWEVER... THE LATEST HI-RES MODELS CONTINUE TO INDICATE SOME OF
THIS ACTIVITY MOVING INTO/DEVELOPING ACROSS OUR NORTHERN PIEDMONT
AND NORTHERN COASTAL PLAIN COUNTIES AS RAIN COOLED OUTFLOW FROM
CURRENT ACTIVITY ACROSS SOUTHERN VA HELPS TO OVERCOME THE NEAR
SURFACE STABLE LAYER. THIS ACTIVITY HAS DECREASED IN COVERAGE OVER
THE LAST SEVERAL HOURS THOUGH... THANKS IN PART TO A STABILIZING
BOUNDARY LAYER AND LACK OF ANY SIGNIFICANT UPPER DYNAMICS.
HOWEVER... GIVEN WESTERLY DEEP LAYER SHEAR OF AROUND 30 TO 40 KTS
AND STEEP MID LEVEL LAPSE RATES OF AROUND 7.5-8 DEGREES C/KM (WHICH
IS ALSO HELPING TO KEEP THE STORMS GOING) EXPECT WE COULD SEE SOME
STRONG WINDS GUSTS AND SMALL HAIL WITH THE STRONGEST STORMS (HIGHEST
THREAT AREA BASED ON CURRENT RADAR APPEARS TO CURRENTLY BE ACROSS
THE FAR NE PIEDMONT NEAR THE NC/VA BORDER AND THE FAR NORTHERN
COASTAL PLAIN)... WITH A VERY SMALL/WANING POTENTIAL OF AN ISOLATED
SEVERE STORM. THE LATEST HRRR SHOWS THE SHOWERS AND STORMS GENERALLY
ENDING ACROSS OUR AREA BY AROUND 05/06Z OR SO... WITH GENERALLY
ISOLATED TO SCATTERED COVERAGE ACROSS THE AFOREMENTIONED AREAS
THROUGH THEN. WILL CONTINUE TO GO WITH CHANCE POPS ACROSS THE FAR
NORTH WITH SLIGHT CHANCE POPS FOR SHOWERS AND STORMS AS FAR SOUTH AS
U.S. HIGHWAY 64... THROUGH 06/07Z. THUS... STILL THINK GIVEN THE
LACK OF APPRECIABLE UPPER FORCING AND STABILIZING BOUNDARY LAYER
THAT WE WILL SEE THE SHOWERS AND STORMS COME TO AN END BY THEN.
THE ACTUAL FRONT DOES NOT START TO PUSH SOUTHWARD THROUGH THE AREA
UNTIL AROUND 12Z THURSDAY... WHICH IS CURRENTLY EXTENDS FROM PORTION
OF SOUTHERN PA WSW`WARD INTO WV AND NORTHERN KY. THUS... WILL
CONTINUE TO GO WITH MILD OVERNIGHT LOWS RANGING FROM 56-60 DEGREES.
THURSDAY...SURFACE COLD FRONT WILL DRIFT SWD ACROSS THE SOUTHERN
COUNTIES EARLY THU MORNING. WHILE MOISTURE THROUGH THE COLUMN
ADEQUATE TO SUPPORT A FEW SHOWERS...FORCING WEAK OR NON-EXISTENT.
THUS ASIDE FROM SOME CLOUDINESS AND THE SURFACE WINDS SHIFTING TO
THE NW...FRONTAL PASSAGE WILL GO THROUGH VIRTUALLY UNEVENTFUL.
SUBSIDENCE BEHIND THE EXITING TROUGH WILL AID TO QUICKLY DIMINISH
CLOUD COVERAGE WITH MOSTLY SUNNY SKIES EXPECTED ALL LOCALES BY LATE
MORNING. WHILE 850MB NW...TEMP ADVECTION NEUTRAL OR SLIGHT CAA.
SINCE FLOW HAS DEFINITIVE DOWNSLOPE COMPONENT...ANY CAA WILL BE
OFFSET BY THE COMPRESSIONAL WARMING. MOS GUIDANCE IN THE 80-85
DEGREE RANGE APPEARS A TOUCH OVERDONE...SO FAVOR MAX TEMPS IN THE
UPPER 70S FAR NORTH TO LOWER 80S SOUTH.
THURSDAY NIGHT...HIGH PRESSURE CENTERED OVER ONTARIO WILL NOSE SWD
INTO CENTRAL NC. THIS WEATHER FEATURE SHOULD PROVIDE US WITH CLEAR
SKIES AND LIGHT NE FLOW. THIS WILL LEAD TO COOLER TEMPS WITH MIN
TEMPS MID 40S NE TO LOW/MID 50S FAR SOUTH.
ON FRIDAY WE`LL SEE THE HIGH PRESSURE TO OUR NORTH MOVE OFFSHORE AND
THE OLD COLD FRONT TO OUR SOUTH BEGIN TO LIFT NORTH AS A WARM FRONT
IN ADVANCE OF THE NEXT SHORT WAVE TO OUR WEST CROSSING THE OHIO
RIVER VALLEY. AFTER A MAINLY CLEAR START TO THE DAY...EXPECT TO SEE
INCREASING CLOUDINESS LATER IN THE DAY AND WARMING TEMPS WITH
SOUTHWEST LOW LEVEL FLOW INCREASING. AFTER A COOL START FRIDAY
MORNING...SOUNDINGS SUGGEST TEMPS WILL MODERATE TO NEAR NORMAL
VALUES IN THE AFTERNOON...GENERALLY UPPER 70S TO AROUND 80.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 325 AM...
A SHORT WAVE IS FORECAST TO BE APPROACHING THE MID ATLANTIC STATES
SATURDAY WITH A SURFACE LOW IN THE VICINITY OF DELAWARE. WITH
NORTHWEST FLOW ALOFT... THERE WOULD BE LIMITED POTENTIAL FOR RAIN...
CONFINED TO THE EAST DURING THE MORNING... WITH THE SURFACE LOW
EXITING INTO THE ATLANTIC EARLY IN THE DAY. UPPER LEVEL RIDGING
APPROACHED THE AREA FROM THE WEST. HIGH TEMPERATURES 80 TO 84
SATURDAY... UPPER 70S TO LOWER 80S SUNDAY. LOW TEMPERATURES IN THE
MID TO UPPER 50S.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 325 AM...
MAJORITY OF OPERATIONAL MODELS CLOSING OFF AN UPPER LOW IN THE
SOUTHERN ROCKIES OR PLAINS MONDAY WITH THE ECMWF CONTINUING WITH AN
OPEN WAVE. REGARDLESS THE MORE RAPID ADVANCE OF THE GFS IS DISCARDED
WITH THE EAST COAST RIDGE MUCH MORE PERSISTENT ON MOST MODELS. HAVE
DELAYED ANY SIGNIFICANT RAIN CHANCES (SLIGHT) UNTIL TUESDAY
AFTERNOON... ALTHOUGH THE UKMET AND CANADIAN SUGGEST EVEN THIS IS
TOO AGGRESSIVE. SHOULD THE TROUGH OR WAVE MOVE THROUGH CENTRAL NORTH
CAROLINA TUESDAY NIGHT... CLEARING SKIES AND COOLER TEMPERATURES
WOULD BE EXPECTED. THIS WOULD BE PERSISTENT WITH CURRENT FORECAST
AND HPC GUIDANCE AND ACCEPTED WITH LOW CONFIDENCE.
EXPECT HIGH TEMPERATURES IN THE MID 80S UNDER THE UPPER RIDGE WITH
UPPER 70S TO LOWER 80S TUESDAY WITH MORE CLOUDINESS AND MOISTURE.
ASSUMING THE SURFACE TROUGH PASSES THROUGH TUESDAY... HIGHS FALL TO
THE LOW TO MID 70S. LOW TEMPERATURES MID TO UPPER 50S UNTIL TUESDAY
NIGHT... WHEN SUNRISE TEMPERATURES WEDNESDAY SLIP TO 50 TO 55.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
AS OF 225 AM THURSDAY...
IT APPEARS THAT A BAND OF SHOWERS AND EVEN AN ISOLATED THUNDERSTORM
-- AND AN ASSOCIATED GUSTY WNW WIND AND VERY BRIEF MVFR CEILING/
VISIBILITY -- OVER SW VA AND NW NC AT 06Z WILL HOLD TOGETHER AND
THREATEN KGSO/KINT THROUGH ABOUT 08Z. OVERALL...THIS ACTIVITY IS
EXPECTED TO GRADUALLY DISSIPATE AS IT MOVES SOUTHEASTWARD INTO
CENTRAL NC...BUT CURRENT INDICATIONS ARE THAT IT MAY HOLD TOGETHER
TO AFFECT KRDU BETWEEN 07-08Z. OTHERWISE...VFR CONDITIONS WILL HOLD
THROUGH THE 06Z TAF PERIOD. A SOUTHWEST BREEZE WILL GRADUALLY VEER
TO NORTHWEST AND LESSEN THROUGH DAYBREAK...THEN INCREASE INTO THE
9-13 KT RANGE WITH OCCASIONAL GUSTINESS INTO THE MID-UPPER TEENS KTS
FROM MIDDAY THROUGH THIS AFTERNOON. WINDS WILL THEN BECOME LIGHT
NORTH TO NORTHEASTERLY AFTER 00Z...AS A DRY COLD FRONT SETTLES
SOUTHWARD INTO SC.
OUTLOOK:
A PERIOD OF MVFR CEILINGS...MAINLY AT KRDU AND KRWI...WILL BE
POSSIBLE LATE-MORNING THROUGH THE AFTERNOON FRI...AS THE
AFOREMENTIONED SURFACE FRONT RETURNS NORTHWARD AS A WARM FRONT
DURING THE DAY. THE PASSAGE OF THE BOUNDARY AND RESULTANT INCREASING
LIFT AND HUMIDITY WILL ALSO PROMOTE THE DEVELOPMENT OF SCATTERED
AFTERNOON THUNDERSTORMS MAINLY AT KRDU/KRWI/KFAY...FOLLOWED BY A LOW
CHANCE OF STRATUS...AND A CONTINUED THREAT OF A SHOWER OR STORM...
FRI NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...WSS
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
228 AM EDT THU MAR 29 2012
.SYNOPSIS...
A DRY COLD FRONT WILL CROSS NC TODAY AND SETTLE INTO SC TONIGHT. THE
FRONT WILL RETURN NORTHWARD AS A WARM FRONT ON FRIDAY...IN ADVANCE
OF A LOW PRESSURE SYSTEM AND TRAILING COLD FRONT THAT WILL CROSS THE
MIDDLE ATLANTIC STATES FRIDAY NIGHT THROUGH SATURDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10 PM EDT WEDNESDAY...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH AN APPROACHING COLD FRONT
HAVE REMAINED GENERALLY TO THE NORTH OF THE AREA THIS EVENING.
HOWEVER... THE LATEST HI-RES MODELS CONTINUE TO INDICATE SOME OF
THIS ACTIVITY MOVING INTO/DEVELOPING ACROSS OUR NORTHERN PIEDMONT
AND NORTHERN COASTAL PLAIN COUNTIES AS RAIN COOLED OUTFLOW FROM
CURRENT ACTIVITY ACROSS SOUTHERN VA HELPS TO OVERCOME THE NEAR
SURFACE STABLE LAYER. THIS ACTIVITY HAS DECREASED IN COVERAGE OVER
THE LAST SEVERAL HOURS THOUGH... THANKS IN PART TO A STABILIZING
BOUNDARY LAYER AND LACK OF ANY SIGNIFICANT UPPER DYNAMICS.
HOWEVER... GIVEN WESTERLY DEEP LAYER SHEAR OF AROUND 30 TO 40 KTS
AND STEEP MID LEVEL LAPSE RATES OF AROUND 7.5-8 DEGREES C/KM (WHICH
IS ALSO HELPING TO KEEP THE STORMS GOING) EXPECT WE COULD SEE SOME
STRONG WINDS GUSTS AND SMALL HAIL WITH THE STRONGEST STORMS (HIGHEST
THREAT AREA BASED ON CURRENT RADAR APPEARS TO CURRENTLY BE ACROSS
THE FAR NE PIEDMONT NEAR THE NC/VA BORDER AND THE FAR NORTHERN
COASTAL PLAIN)... WITH A VERY SMALL/WANING POTENTIAL OF AN ISOLATED
SEVERE STORM. THE LATEST HRRR SHOWS THE SHOWERS AND STORMS GENERALLY
ENDING ACROSS OUR AREA BY AROUND 05/06Z OR SO... WITH GENERALLY
ISOLATED TO SCATTERED COVERAGE ACROSS THE AFOREMENTIONED AREAS
THROUGH THEN. WILL CONTINUE TO GO WITH CHANCE POPS ACROSS THE FAR
NORTH WITH SLIGHT CHANCE POPS FOR SHOWERS AND STORMS AS FAR SOUTH AS
U.S. HIGHWAY 64... THROUGH 06/07Z. THUS... STILL THINK GIVEN THE
LACK OF APPRECIABLE UPPER FORCING AND STABILIZING BOUNDARY LAYER
THAT WE WILL SEE THE SHOWERS AND STORMS COME TO AN END BY THEN.
THE ACTUAL FRONT DOES NOT START TO PUSH SOUTHWARD THROUGH THE AREA
UNTIL AROUND 12Z THURSDAY... WHICH IS CURRENTLY EXTENDS FROM PORTION
OF SOUTHERN PA WSW`WARD INTO WV AND NORTHERN KY. THUS... WILL
CONTINUE TO GO WITH MILD OVERNIGHT LOWS RANGING FROM 56-60 DEGREES.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
AS OF 305 PM WEDNESDAY...
THURSDAY...SURFACE COLD FRONT WILL DRIFT SWD ACROSS THE SOUTHERN
COUNTIES EARLY THU MORNING. WHILE MOISTURE THROUGH THE COLUMN
ADEQUATE TO SUPPORT A FEW SHOWERS...FORCING WEAK OR NON-EXISTENT.
THUS ASIDE FROM SOME CLOUDINESS AND THE SURFACE WINDS SHIFTING TO
THE NW...FRONTAL PASSAGE WILL GO THROUGH VIRTUALLY UNEVENTFUL.
SUBSIDENCE BEHIND THE EXITING TROUGH WILL AID TO QUICKLY DIMINISH
CLOUD COVERAGE WITH MOSTLY SUNNY SKIES EXPECTED ALL LOCALES BY LATE
MORNING. WHILE 850MB NW...TEMP ADVECTION NEUTRAL OR SLIGHT CAA.
SINCE FLOW HAS DEFINITIVE DOWNSLOPE COMPONENT...ANY CAA WILL BE
OFFSET BY THE COMPRESSIONAL WARMING. MOS GUIDANCE IN THE 80-85
DEGREE RANGE APPEARS A TOUCH OVERDONE...SO FAVOR MAX TEMPS IN THE
UPPER 70S FAR NORTH TO LOWER 80S SOUTH.
THURSDAY NIGHT...HIGH PRESSURE CENTERED OVER ONTARIO WILL NOSE SWD
INTO CENTRAL NC. THIS WEATHER FEATURE SHOULD PROVIDE US WITH CLEAR
SKIES AND LIGHT NE FLOW. THIS WILL LEAD TO COOLER TEMPS WITH MIN
TEMPS MID 40S NE TO LOW/MID 50S FAR SOUTH.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 130 PM WEDNESDAY...
ON FRIDAY WE`LL SEE THE HIGH PRESSURE TO OUR NORTH MOVE OFFSHORE AND
THE OLD COLD FRONT TO OUR SOUTH BEGIN TO LIFT NORTH AS A WARM FRONT
IN ADVANCE OF THE NEXT SHORT WAVE TO OUR WEST CROSSING THE OHIO
RIVER VALLEY. AFTER A MAINLY CLEAR START TO THE DAY...EXPECT TO SEE
INCREASING CLOUDINESS LATER IN THE DAY AND WARMING TEMPS WITH
SOUTHWEST LOW LEVEL FLOW INCREASING. AFTER A COOL START FRIDAY
MORNING...SOUNDINGS SUGGEST TEMPS WILL MODERATE TO NEAR NORMAL
VALUES IN THE AFTERNOON...GENERALLY UPPER 70S TO AROUND 80.
WE CONTINUE TO SEE SIGNIFICANT DIFFERENCES IN MODEL SOLUTIONS
BEGINNING FRIDAY NIGHT. THE LATEST GFS AND MOST OTHER MODELS ARE
PROGRESSIVE WITH THE AFOREMENTIONED SHORT WAVE THAT WILL BE CROSSING
THE OHIO RIVER VALLEY DURING THE DAYTIME FRIDAY...AND MOVE IT AND
ITS ATTENDANT SFC COLD FRONT ACROSS OUR AREA LATE ON SATURDAY
FOLLOWED BY HIGH PRESSURE BUILDING ACROSS THE AREA FROM THE NORTH
SATURDAY NIGHT AND SUNDAY. MEANWHILE...THE 0Z ECMWF CONTINUES TO
INDICATE A MUCH DIFFERENT SOLUTION THAT BASICALLY SLOWS THE
SHORTWAVE AND DELAYS THE FRONTAL PASSAGE UNTIL SUNDAY. THE GFS AND
OTHER PROGRESSIVE MODELS BASICALLY RESULT IN LOWER-IMPACT SHOWERS
AND TSTMS LATE FRIDAY AND SATURDAY FOLLOWED BY FAIR WEATHER ON
SUNDAY...WHILE THE 0Z ECMWF WOULD SUGGEST POTENTIALLY HIGHER-IMPACT
THUNDERSTORMS DURING THE DAYTIME SATURDAY AND POSSIBLY AGAIN ON
SUNDAY WITH THE FRONTAL PASSAGE. GIVEN THE LOWER-THAN-USUAL
CONFIDENCE...FOR NOW WILL MAKE FEW CHANGES TO CURRENT FORECAST...
WHICH SHOWS RAIN CHANCES INCREASING FRIDAY NIGHT AND CONTINUING INTO
SATURDAY NIGHT THEN DIMINISHING POPS ON SUNDAY. WORTH REPEATING THAT
IF THE TREND GOES TOWARD THE 0Z ECMWF...THE RISK FOR AN ACTIVE
THUNDERSTORM DAY ON SATURDAY INCREASES. TEMPS DURING THE WEEKEND
WILL BE HIGHLY DEPENDENT ON THE EVOLUTION OF THE PRECIP AND FRONTAL
TIMING. FOR NOW WILL CONTINUE ABOVE NORMAL TEMPS SATURDAY IN THE
PREFRONTAL ENVIRONMENT...THEN COOLER ON SUNDAY WITH EITHER THE FRONT
TO OUR SOUTH (GFS)...OR DUE TO PRECIP (ECMWF) KEEPING TEMPS DOWN.
MODELS COME INTO BETTER AGREEMENT EARLY NEXT WEEK...AND INDICATE A
RIDGE ACROSS OUR REGION ON MONDAY YIELDING FAIR WEATHER WITH TEMPS
10+ DEGREES ABOVE NORMAL...FOLLOWED BY A HIGHLY AMPLIFIED TROUGH
AFFECTING THE EASTERN PORTION OF THE COUNTRY DURING THE MIDDLE OF
THE WEEK. THIS TROUGH WILL PUSH A SFC COLD FRONT ACROSS OUR AREA ON
TUESDAY AND WILL START A MUCH COOLER TREND THAT WILL LINGER THROUGH
THE MIDDLE TO LATTER PART OF THE WEEK. EXPECT A CHANCE FOR SHOWERS
AND THUNDERSTORMS ALONG AND AHEAD OF TUESDAYS COLD FRONT...OTHERWISE
MUCH OF NEXT WEEK SHOULD BE DRY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 225 AM THURSDAY...
IT APPEARS THAT A BAND OF SHOWERS AND EVEN AN ISOLATED THUNDERSTORM
-- AND AN ASSOCIATED GUSTY WNW WIND AND VERY BRIEF MVFR CEILING/
VISIBILITY -- OVER SW VA AND NW NC AT 06Z WILL HOLD TOGETHER AND
THREATEN KGSO/KINT THROUGH ABOUT 08Z. OVERALL...THIS ACTIVITY IS
EXPECTED TO GRADUALLY DISSIPATE AS IT MOVES SOUTHEASTWARD INTO
CENTRAL NC...BUT CURRENT INDICATIONS ARE THAT IT MAY HOLD TOGETHER
TO AFFECT KRDU BETWEEN 07-08Z. OTHERWISE...VFR CONDITIONS WILL HOLD
THROUGH THE 06Z TAF PERIOD. A SOUTHWEST BREEZE WILL GRADUALLY VEER
TO NORTHWEST AND LESSEN THROUGH DAYBREAK...THEN INCREASE INTO THE
9-13 KT RANGE WITH OCCASIONAL GUSTINESS INTO THE MID-UPPER TEENS KTS
FROM MIDDAY THROUGH THIS AFTERNOON. WINDS WILL THEN BECOME LIGHT
NORTH TO NORTHEASTERLY AFTER 00Z...AS A DRY COLD FRONT SETTLES
SOUTHWARD INTO SC.
OUTLOOK:
A PERIOD OF MVFR CEILINGS...MAINLY AT KRDU AND KRWI...WILL BE
POSSIBLE LATE-MORNING THROUGH THE AFTERNOON FRI...AS THE
AFOREMENTIONED SURFACE FRONT RETURNS NORTHWARD AS A WARM FRONT
DURING THE DAY. THE PASSAGE OF THE BOUNDARY AND RESULTANT INCREASING
LIFT AND HUMIDITY WILL ALSO PROMOTE THE DEVELOPMENT OF SCATTERED
AFTERNOON THUNDERSTORMS MAINLY AT KRDU/KRWI/KFAY...FOLLOWED BY A LOW
CHANCE OF STRATUS...AND A CONTINUED THREAT OF A SHOWER OR STORM...
FRI NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...BSD
SHORT TERM...WSS
LONG TERM...NP
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
128 AM EDT THU MAR 29 2012
.SYNOPSIS...
A DRY COLD FRONT WILL CROSS NC TODAY AND SETTLE INTO SC TONIGHT. THE
FRONT WILL RETURN NORTHWARD AS A WARM FRONT ON FRIDAY...IN ADVANCE
OF A LOW PRESSURE SYSTEM AND TRAILING COLD FRONT THAT WILL CROSS THE
MIDDLE ATLANTIC STATES FRIDAY NIGHT THROUGH SATURDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10 PM EDT WEDNESDAY...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH AN APPROACHING COLD FRONT
HAVE REMAINED GENERALLY TO THE NORTH OF THE AREA THIS EVENING.
HOWEVER... THE LATEST HI-RES MODELS CONTINUE TO INDICATE SOME OF
THIS ACTIVITY MOVING INTO/DEVELOPING ACROSS OUR NORTHERN PIEDMONT
AND NORTHERN COASTAL PLAIN COUNTIES AS RAIN COOLED OUTFLOW FROM
CURRENT ACTIVITY ACROSS SOUTHERN VA HELPS TO OVERCOME THE NEAR
SURFACE STABLE LAYER. THIS ACTIVITY HAS DECREASED IN COVERAGE OVER
THE LAST SEVERAL HOURS THOUGH... THANKS IN PART TO A STABILIZING
BOUNDARY LAYER AND LACK OF ANY SIGNIFICANT UPPER DYNAMICS.
HOWEVER... GIVEN WESTERLY DEEP LAYER SHEAR OF AROUND 30 TO 40 KTS
AND STEEP MID LEVEL LAPSE RATES OF AROUND 7.5-8 DEGREES C/KM (WHICH
IS ALSO HELPING TO KEEP THE STORMS GOING) EXPECT WE COULD SEE SOME
STRONG WINDS GUSTS AND SMALL HAIL WITH THE STRONGEST STORMS (HIGHEST
THREAT AREA BASED ON CURRENT RADAR APPEARS TO CURRENTLY BE ACROSS
THE FAR NE PIEDMONT NEAR THE NC/VA BORDER AND THE FAR NORTHERN
COASTAL PLAIN)... WITH A VERY SMALL/WANING POTENTIAL OF AN ISOLATED
SEVERE STORM. THE LATEST HRRR SHOWS THE SHOWERS AND STORMS GENERALLY
ENDING ACROSS OUR AREA BY AROUND 05/06Z OR SO... WITH GENERALLY
ISOLATED TO SCATTERED COVERAGE ACROSS THE AFOREMENTIONED AREAS
THROUGH THEN. WILL CONTINUE TO GO WITH CHANCE POPS ACROSS THE FAR
NORTH WITH SLIGHT CHANCE POPS FOR SHOWERS AND STORMS AS FAR SOUTH AS
U.S. HIGHWAY 64... THROUGH 06/07Z. THUS... STILL THINK GIVEN THE
LACK OF APPRECIABLE UPPER FORCING AND STABILIZING BOUNDARY LAYER
THAT WE WILL SEE THE SHOWERS AND STORMS COME TO AN END BY THEN.
THE ACTUAL FRONT DOES NOT START TO PUSH SOUTHWARD THROUGH THE AREA
UNTIL AROUND 12Z THURSDAY... WHICH IS CURRENTLY EXTENDS FROM PORTION
OF SOUTHERN PA WSW`WARD INTO WV AND NORTHERN KY. THUS... WILL
CONTINUE TO GO WITH MILD OVERNIGHT LOWS RANGING FROM 56-60 DEGREES.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
AS OF 305 PM WEDNESDAY...
THURSDAY...SURFACE COLD FRONT WILL DRIFT SWD ACROSS THE SOUTHERN
COUNTIES EARLY THU MORNING. WHILE MOISTURE THROUGH THE COLUMN
ADEQUATE TO SUPPORT A FEW SHOWERS...FORCING WEAK OR NON-EXISTENT.
THUS ASIDE FROM SOME CLOUDINESS AND THE SURFACE WINDS SHIFTING TO
THE NW...FRONTAL PASSAGE WILL GO THROUGH VIRTUALLY UNEVENTFUL.
SUBSIDENCE BEHIND THE EXITING TROUGH WILL AID TO QUICKLY DIMINISH
CLOUD COVERAGE WITH MOSTLY SUNNY SKIES EXPECTED ALL LOCALES BY LATE
MORNING. WHILE 850MB NW...TEMP ADVECTION NEUTRAL OR SLIGHT CAA.
SINCE FLOW HAS DEFINITIVE DOWNSLOPE COMPONENT...ANY CAA WILL BE
OFFSET BY THE COMPRESSIONAL WARMING. MOS GUIDANCE IN THE 80-85
DEGREE RANGE APPEARS A TOUCH OVERDONE...SO FAVOR MAX TEMPS IN THE
UPPER 70S FAR NORTH TO LOWER 80S SOUTH.
THURSDAY NIGHT...HIGH PRESSURE CENTERED OVER ONTARIO WILL NOSE SWD
INTO CENTRAL NC. THIS WEATHER FEATURE SHOULD PROVIDE US WITH CLEAR
SKIES AND LIGHT NE FLOW. THIS WILL LEAD TO COOLER TEMPS WITH MIN
TEMPS MID 40S NE TO LOW/MID 50S FAR SOUTH.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 130 PM WEDNESDAY...
ON FRIDAY WE`LL SEE THE HIGH PRESSURE TO OUR NORTH MOVE OFFSHORE AND
THE OLD COLD FRONT TO OUR SOUTH BEGIN TO LIFT NORTH AS A WARM FRONT
IN ADVANCE OF THE NEXT SHORT WAVE TO OUR WEST CROSSING THE OHIO
RIVER VALLEY. AFTER A MAINLY CLEAR START TO THE DAY...EXPECT TO SEE
INCREASING CLOUDINESS LATER IN THE DAY AND WARMING TEMPS WITH
SOUTHWEST LOW LEVEL FLOW INCREASING. AFTER A COOL START FRIDAY
MORNING...SOUNDINGS SUGGEST TEMPS WILL MODERATE TO NEAR NORMAL
VALUES IN THE AFTERNOON...GENERALLY UPPER 70S TO AROUND 80.
WE CONTINUE TO SEE SIGNIFICANT DIFFERENCES IN MODEL SOLUTIONS
BEGINNING FRIDAY NIGHT. THE LATEST GFS AND MOST OTHER MODELS ARE
PROGRESSIVE WITH THE AFOREMENTIONED SHORT WAVE THAT WILL BE CROSSING
THE OHIO RIVER VALLEY DURING THE DAYTIME FRIDAY...AND MOVE IT AND
ITS ATTENDANT SFC COLD FRONT ACROSS OUR AREA LATE ON SATURDAY
FOLLOWED BY HIGH PRESSURE BUILDING ACROSS THE AREA FROM THE NORTH
SATURDAY NIGHT AND SUNDAY. MEANWHILE...THE 0Z ECMWF CONTINUES TO
INDICATE A MUCH DIFFERENT SOLUTION THAT BASICALLY SLOWS THE
SHORTWAVE AND DELAYS THE FRONTAL PASSAGE UNTIL SUNDAY. THE GFS AND
OTHER PROGRESSIVE MODELS BASICALLY RESULT IN LOWER-IMPACT SHOWERS
AND TSTMS LATE FRIDAY AND SATURDAY FOLLOWED BY FAIR WEATHER ON
SUNDAY...WHILE THE 0Z ECMWF WOULD SUGGEST POTENTIALLY HIGHER-IMPACT
THUNDERSTORMS DURING THE DAYTIME SATURDAY AND POSSIBLY AGAIN ON
SUNDAY WITH THE FRONTAL PASSAGE. GIVEN THE LOWER-THAN-USUAL
CONFIDENCE...FOR NOW WILL MAKE FEW CHANGES TO CURRENT FORECAST...
WHICH SHOWS RAIN CHANCES INCREASING FRIDAY NIGHT AND CONTINUING INTO
SATURDAY NIGHT THEN DIMINISHING POPS ON SUNDAY. WORTH REPEATING THAT
IF THE TREND GOES TOWARD THE 0Z ECMWF...THE RISK FOR AN ACTIVE
THUNDERSTORM DAY ON SATURDAY INCREASES. TEMPS DURING THE WEEKEND
WILL BE HIGHLY DEPENDENT ON THE EVOLUTION OF THE PRECIP AND FRONTAL
TIMING. FOR NOW WILL CONTINUE ABOVE NORMAL TEMPS SATURDAY IN THE
PREFRONTAL ENVIRONMENT...THEN COOLER ON SUNDAY WITH EITHER THE FRONT
TO OUR SOUTH (GFS)...OR DUE TO PRECIP (ECMWF) KEEPING TEMPS DOWN.
MODELS COME INTO BETTER AGREEMENT EARLY NEXT WEEK...AND INDICATE A
RIDGE ACROSS OUR REGION ON MONDAY YIELDING FAIR WEATHER WITH TEMPS
10+ DEGREES ABOVE NORMAL...FOLLOWED BY A HIGHLY AMPLIFIED TROUGH
AFFECTING THE EASTERN PORTION OF THE COUNTRY DURING THE MIDDLE OF
THE WEEK. THIS TROUGH WILL PUSH A SFC COLD FRONT ACROSS OUR AREA ON
TUESDAY AND WILL START A MUCH COOLER TREND THAT WILL LINGER THROUGH
THE MIDDLE TO LATTER PART OF THE WEEK. EXPECT A CHANCE FOR SHOWERS
AND THUNDERSTORMS ALONG AND AHEAD OF TUESDAYS COLD FRONT...OTHERWISE
MUCH OF NEXT WEEK SHOULD BE DRY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 125 AM THURSDAY...
IT APPEARS THAT A BAND OF SHOWERS AND EVEN AN ISOLATED THUNDERSTORM
-- AND AN ASSOCIATED GUSTY WNW WIND AND VERY BRIEF MVFR CEILING/
VISIBILITY -- OVER SW VA AND NW NC AT 06Z WILL HOLD TOGETHER AND
THREATEN KGSO/KINT THROUGH ABOUT 08Z. OVERALL...THIS ACTIVITY IS
EXPECTED TO GRADUALLY DISSIPATE AS IT MOVES SOUTHEASTWARD INTO
CENTRAL NC...BUT CURRENT INDICATIONS ARE THAT IT MAY HOLD TOGETHER
TO AFFECT KRDU BETWEEN 07-08Z. OTHERWISE...VFR CONDITIONS WILL HOLD
THROUGH THE 06Z TAF PERIOD. A SOUTHWEST BREEZE WILL GRADUALLY VEER
TO NORTHWEST AND LESSEN THROUGH DAYBREAK...THEN INCREASE INTO THE
9-13 KT RANGE WITH OCCASIONAL GUSTINESS INTO THE MID-UPPER TEENS KTS
FROM MIDDAY THROUGH THIS AFTERNOON. WINDS WILL THEN BECOME LIGHT
NORTH TO NORTHEASTERLY AFTER 00Z...AS A DRY COLD FRONT SETTLES
SOUTHWARD INTO SC.
OUTLOOK:
A PERIOD OF MVFR CEILINGS...MAINLY AT KRDU AND KRWI...WILL BE
POSSIBLE LATE-MORNING THROUGH THE AFTERNOON FRI...AS THE
AFOREMENTIONED SURFACE FRONT RETURNS NORTHWARD AS A WARM FRONT
DURING THE DAY. THE PASSAGE OF THE BOUNDARY AND RESULTANT INCREASING
LIFT AND HUMIDITY WILL ALSO PROMOTE THE DEVELOPMENT OF SCATTERED
AFTERNOON THUNDERSTORMS MAINLY AT KRDU/KRWI/KFAY...FOLLOWED BY A LOW
CHANCE OF STRATUS...AND A CONTINUED THREAT OF A SHOWER OR STORM...
FRI NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...BSD
SHORT TERM...WSS
LONG TERM...NP
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
615 PM EDT THU MAR 29 2012
.SYNOPSIS...
HIGH PRESSURE WILL SHIFT EAST OF THE AREA TONIGHT. FRIDAY LOW
PRESSURE WILL MOVE ACROSS NORTHERN OHIO FROM THE WEST BRINGING A
THREAT OF SHOWERS AND THUNDERSTORMS TO THE REGION. HIGH PRESSURE
WILL BUILD INTO THE AREA LATE SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
NO CHANGES NEEDED FOR 630 PM UPDATE.
COMPLICATED FORECAST FOR TONIGHT WITH REGARD TO THE CURRENT
FROST/FREEZE HEADLINES. PERSISTENT STRATUS DECK CONTINUES TO ERODE
AND SHOULD LEAD TO SOME FAIRLY CLEAR SKIES FOR A WHILE TONIGHT.
SINCE TEMPS OVER MUCH OF THE EAST HALF OF THE AREA ALREADY NOT FAR
FROM THE FREEZING POINT...ANY CLEARING SHOULD SET THE STAGE FOR
FREEZING CONDITIONS TO OCCUR. THUS NOT CHANGES TO FROST/FREEZE
HEADLINES.
FIRST CONVECTIVE COMPLEX OVER IL IS WEAKENING AND WITH LOW LEVEL
DRIER FURTHER TO THE EAST NOT SEEING HOW THE HRRR MODEL CAN POSSIBLY
BE RIGHT WITH MEASURABLE PRECIP MOVING INTO THE SW PART OF THE AREA
BETWEEN 06Z AND 08Z.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY NIGHT/...
COMPACT SHORTWAVE TO MOVE QUICKLY THROUGH THE FLOW AND ACROSS THE
OHIO VALLEY FRIDAY. SOUTHWEST PART OF THE AREA IDENTIFIED IN A
SLIGHT RISK AREA FOR SEVERE THUNDERSTORMS. LOW CENTER SHOULD TRACK
WEST TO EAST ALONG U.S. ROUTE 30. GOOD PRECIP SHIELD EXPECTED
NORTH OF THE LOW TRACK TOO WITH EMBEDDED THUNDER...ACROSS
MI...LAKE ERIE/NRN OH...AND INTO NW PA. WILL HAVE CATEGORICAL POPS
FOR ALL. WILL HAVE A DECENT GRADIENT IN TEMPERATURE WITH ERIE
LIKELY HAVING A NORTHERLY COMPONENT WIND BY LATE IN THE DAY AND
THE WARM FRONT NOT MAKING IT MUCH FURTHER NORTH THAN MANSFIELD.
WILL HAVE UPPER 40S ACROSS THE EXTREME NORTHEAST AND MID 60S DOWN
AROUND MT VERNON. SHOWERS/THUNDERSTORMS SHOULD BE EAST OF THE I71
CORRIDOR BY 8PM. TEMPS WILL DROP BACK INTO THE 30S FRIDAY NIGHT.
QUESTION AS TO HOW MUCH SHOWERY ACTIVITY LINGERS ACROSS THE
EXTREME EAST SNOWBELT OVERNIGHT INTO SATURDAY MORNING.
SATURDAY HIGH PRESSURE WILL AGAIN NOSE SOUTH ACROSS THE GREAT
LAKES FROM CANADA INTO THE OHIO VALLEY WITH ONLY WEAK RIDGING
ALOFT. WILL HAVE SEASONABLE TEMPERATURES.
MODELS STRUGGLE WITH WHAT TO DO ON SUNDAY. WHILE IT LOOKS
WARMER...GFS AND NAM WANT TO TAKE A QUICK COLD FRONT ACROSS THE
AREA AND WILL SQUASH TEMPS SOMEWHAT ACROSS AT LEAST THE NORTHEAST.
WILL PUT IN A CHANCE OF SHOWERS AND HAVE A GRADIENT IN TEMPS FROM
AROUND 60 IN NW PA TO THE LOWER AND POSSIBLY MID 70S NEAR FINDLAY.
ECMWF DOES NOT HAVE MUCH OF THIS FEATURE AT ALL AND IS BUILDING
HEIGHTS/RIDGE AND REALLY WARMING THINGS UP.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
A FRONT WILL BE DRAPED ACROSS THE LOCAL AREA AT THE START OF
PERIOD. THERE COULD BE SOME LINGERING PRECIP ALONG THIS FEATURE BUT
NOT EXPECTING MUCH IN THE WAY OF QPF. WILL JUST MAINTAIN A SMALL
MENTION IN THE FORECAST. THE BIG STORY THE REMAINDER OF THE PERIOD
WILL BE A POTENT LOW THAT IS EXPECTED TO MOVE EAST ACROSS THE OHIO
VALLEY DURING THE MIDDLE PORTION OF THE WEEK. THE 12Z GUIDANCE IS
MUCH FURTHER SOUTH WITH THIS SYSTEM THAN THE MODELS WERE YESTERDAY.
STILL THINK THE LOCAL AREA WILL SEE PRECIP BUT HAVE BACKED OFF ON
TEMPS SOME FROM THE EARLIER PACKAGE. HIGH PRESSURE WILL REESTABLISH
ITSELF FOR THE END OF THE PERIOD WITH DRY WEATHER EXPECTED ON
THURSDAY. MONDAY WILL BE WARM WITH HIGHS MAINLY IN THE 70S. BY
WEDNESDAY AND THURSDAY TEMPS WILL BE BACK CLOSE TO NORMAL.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
STRATO CU DECK HAS OVERSPREAD ALL OF THE TAF SITES TODAY. DRIER
AIR WILL CONTINUE TO MOVE IN THE AREA AND SHOULD SEE THIS CLOUD
DECK ERODE FROM SW TO NE LATER THIS AFTERNOON. EXPECT ALL SITES
BUT KERI TO BE SCT BY 00Z. HIGH CLOUDS WILL MOVE IN FROM THE WEST
THIS EVENING AND BY MORNING EXPECT MID LEVEL CIGS MOST AREAS.
SHOWERS WILL REACH NW OH BY THE END OF THE PERIOD AS A WARM FRONT
SETS UP ACROSS THE REGION. NW TO N FLOW WILL BECOME NE BY EVENING AND
EASTERLY OVERNIGHT. SPEEDS FOR THE MOST PART WILL BE UNDER 10
KNOTS BUT SOME GUSTINESS POSSIBLE ON FRIDAY ESPECIALLY IN THE
SOUTH WHERE THE FLOW WILL TAKE ON A SOUTHERLY COMPONENT.
.OUTLOOK...NON VFR CONDITIONS LIKELY TO DEVELOP AGAIN ON FRIDAY
WITH SHOWERS THEN CONTINUE INTO SATURDAY.
&&
.MARINE...
SEVERAL SYSTEMS WILL BE MOVING ACROSS THE LAKE THROUGH THE SHORT
TERM PERIOD CREATING A RATHER UNSTABLE WIND PATTERN. HIGH PRESSURE
WILL REMAIN OVER THE LAKE TONIGHT. A WEAK SURFACE LOW IS PROGGED TO
MOVE ACROSS LAKE ERIE ON FRIDAY. THIS WILL CREATE A VARIABLE WIND
PATTERN WITH A MAINLY NORTH TO NORTHEAST FLOW OVER THE LAKE. HIGH
PRESSURE WILL BUILD ONCE AGAIN OVER THE LAKE ON SATURDAY. THE FLOW
WILL GRADUALLY SHIFT TO THE SOUTH IN ADVANCE OF A COLD FRONT ON
SUNDAY. THE CURRENT FORECAST MODELS SHOW SEVERAL STORM SYSTEMS
MOVING TOWARDS THE REGION FOR THE MIDDLE PART OF NEXT WEEK KEEPING
THE PATTERN UNSETTLED.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...FROST ADVISORY FROM 2 AM TO 9 AM EDT FRIDAY FOR OHZ009>012-019-
028>030-036-037-047-089.
FREEZE WARNING FROM 2 AM TO 9 AM EDT FRIDAY FOR OHZ013-014-
020>023-031>033-038.
PA...FROST ADVISORY FROM 2 AM TO 9 AM EDT FRIDAY FOR PAZ001.
FREEZE WARNING FROM 2 AM TO 9 AM EDT FRIDAY FOR PAZ002-003.
MARINE...NONE.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...OUDEMAN/ADAMS
SHORT TERM...OUDEMAN
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...GARNET
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
144 PM EDT THU MAR 29 2012
.SYNOPSIS...
HIGH PRESSURE PASSES TO THE NORTH LATE TODAY. LOW PRESSURE BRINGS
A WARM FRONT...THEN A COLD FRONT FRIDAY...THE LATTER WITH MORE
STORMS LATE FRIDAY. HIGH PRESSURE CROSSES SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
130 PM UPDATE...BUMPED MAX TEMPS UP A FEW DEGREES MAINLY IN THE
MOUNTAINS PER LATEST OBS. OTHERWISE...REMAINDER OF FORECAST ON TRACK.
PREVIOUS DISCUSSION...LATEST IR IMAGERY HAS CLEAR SKY FOR ENTIRE CWA
CURRENTLY. HOWEVER...LOW LEVEL MOISTURE ASSOCIATED WITH THE POST-FRONTAL
TROF TO OUR NORTH IS OOZING SOUTHWARD AND SHOULD BEGIN TO POOL UP AGAINST
THE NRN WV MOUNTAINS EVENTUALLY DEVELOPING OROGRAPHICALLY INDUCED CLOUDS
AND NOTHING MORE.
CURRENT WV IMAGERY SHOWING COPIOUS DRY AIR DIRECTLY OVER OUR
AREA...AND THIS IS HANDLED WELL IN THE RUC H5-H7 LAYER.
THIS...COMBINED WITH MORNING DAYTIME HEATING...SHOULD WORK TO
QUICKLY DISSIPATE THE LOW LEVEL CLOUDS THAT ARE CONTINUING TO
DEVELOP IN THE NRN WV MNTS CURRENTLY. OVERALL...A PLEASANT DAY IS ON
TAP WITH CLEAR SKY CONDITIONS AND TEMPERATURES RETURNING A LITTLE
CLOSER TO SEASONAL AVERAGE.
CLEAR SKY AND MODEST CAA EARLY TONIGHT WILL WORK TO BRING
TEMPERATURES DOWN IN THE NRN ZONES NEARING THE POINT OF FROST
DEVELOPMENT. AT THE SAME TIME...NEAR TERM MODELS HAVE BEEN SPEEDING
UP THE TIMING OF THE APPROACH OF THE NEXT WARM FRONT. 06Z NAM AND
03Z SREF MEAN HAS THETA-E GRADIENT EAST OF THE TUG FORK VALLEY AND
THE TRI-STATE AREA BY 12Z FRI. WITH THIS IN MIND...WILL NOT BE
ISSUING FROST ADVY FOR NRN ZONES WITH THIS ISSUANCE...BUT WILL
MENTION POSSIBILITY FOR PATCHY FROST IN WX GRIDS AND ZONES.
FOR REASONS MENTIONED ABOVE...HAVE SPED UP TIMING OF THE ONSET OF
CLOUD COVER AND POPS ASSOCIATED WITH WARM FRONT TOWARDS THE END OF
THE NEAR TERM. BY MID-DAY FRI...CWA SHOULD BE FIRMLY PLANTED IN THE
WARM SECTOR WITH TEMPS REBOUNDING QUICKLY.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
SHIFTED SAT SYSTEM TO FRI YESTERDAY...RESULTING IN AN ENTIRELY DRY
WEEKEND. NOW IT LOOKS LIKE WE MAY BE TAKING BACK SUNDAY.
FRI SYSTEM REMAINS ON TRACK AS EVEN ECMWF HAS COME AROUND TO THE
FASTER TIMING. NW-SE ORIENTED WARM FRONT...THEN THE WARM
SECTOR...THEN NE-SW ORIENTED COLD FRONT MARCH ACROSS IN A NICE
CLASSICAL SYNOPTIC SETUP. WORRIED PRECIPITATION COULD BREAK OUT
ALONG THE WARM FRONT FRI MORNING...WHICH IS MARKED BY WELL DEFINED
THETA E GRADIENT. WE COULD EVEN SEE A CONVECTIVE COMPLEX SIMILAR TO
WHAT IS GOING ON THIS MORNING OVER THE MIDWEST ALONG SAID GRADIENT.
AFTER A BREAK IN THE WARM SECTOR EARLY FRI AFTERNOON...SHOWERS AND
STRONG THUNDERSTORMS FIRE UP AHEAD OF THE COLD FRONT LATE FRI
AFTERNOON AND TRAVERSE THE AREA FROM NW TO SE THROUGH FRI EVENING.
THE THERMODYNAMIC AND KINEMATIC PARAMETERS LOOK SIMILAR TO THOSE
AHEAD OF THE COLD FRONT THAT TRAVERSED THE AREA LAST NIGHT...SO A
SIMILAR HAIL AND WIND THREAT IS ANTICIPATED. INSTABILITY LOOKS TO
BE GREATEST AS ONE MOVES SW ALONG FRONT...CLOSE TO MOISTURE SOURCE.
INDEED...SPC CONTINUES TO PEG WESTERN PORTIONS OF THE AREA FOR THE
SLIGHT RISK.
WILL KEEP HWO HAZARD AND RWS IMPACT FOR SEVERE THUNDERSTORMS
EMPHASIZING THE W.
COLD ADVECTION IN THE WAKE OF THE SYSTEM SAT WILL BE ACCOMPANIED BY
DEEPER MOISTURE COMPARED WITH TODAY...ALONG WITH SOME SUB FREEZING
LOW LEVEL TEMPERATURES...SO OPTED TO LEAVE SHOWER CHANCE IN THE
MOUNTAINS. ALSO LOTS OF STRATOCU ATOP MIXED LAYER THROUGHOUT THE
AREA.
THE CONUNDRUM SUNDAY IS A NW FLOW WARM ADVECTION FEATURE THAT MAY
AGAIN MATERIALIZE AS A CONVECTIVE COMPLEX. FOR NOW...JUST ADDED THE
SLIGHT CHANCE FOR SHOWERS IN CONCERT WITH NEIGHBORS TO THE N AND W.
THANKS ILN AND PBZ FOR COORD ON THIS CHANGE. WOULD NOT BE SURPRISED
TO SEE THIS BLOW UP INTO SOMETHING MORE IF THE GENERAL PATTERN
EVOLUTION HOLDS.
USED A CACOPHONY OF GUIDANCE BLENDS TO ARRIVE AT TEMPERATURES.
TRIED TO RAISE HIGHS FRI IN THE WARM SECTOR...ESPECIALLY SOUTHERN
AND CENTRAL PORTIONS OF THE AREA. LOWERED A LITTLE FRI NT THROUGH
SAT NT ALTHOUGH NAM12 SUGGESTS IT WILL BE EVEN COLDER. TRENDED
TEMPERATURES UP JUST A BIT SUN AND SUN NT.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
STILL HAVE A DEGREE OF UNCERTAINTY TO THE EXTENDED...PER
USUAL...RESULTING IN A BLEND COMING FROM HPC IN THE FORECAST GRIDS.
DID ADJUST SOME OF THE SKIES DURING THE EXTENDED PERIOD TO BETTER
MATCH UP WITH THE POPS IN THE FORECAST. OVERALL...LOOKING AT MORE
SEASONAL TEMPERATURES...AND DESPITE A COUPLE OF SYSTEMS IN THE LONG
TERM MODELS...OVERALL PRECIPITATION TO COME IN ON THE LOWER SIDE. DO
HAVE A COUPLE OF NIGHTS TOWARDS THE END OF THE PERIOD WHERE WE MAY
NEED TO BE CAREFUL OF FROST AND FREEZE GIVEN THE TRENDS IN THAT TIME
PERIOD WITH A DEEP TROUGH LIFTING OUT AND THE SKY TRYING TO
CLEAR...BUT AS OF NOW...NOTHING TO BE MENTIONED IN THE HWO OR RWS.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
18Z THURSDAY THRU 18Z FRIDAY...GENERALLY VFR THROUGHOUT THE PERIOD.
LIGHT SURFACE WINDS WILL SLOWLY VEER TO THE SOUTH/SOUTHWEST BY THE
MORNING HOURS FRIDAY AS A WARM FRONT LIFTS NORTHWARD ACROSS THE
AREA. SHOWERS AND A FEW THUNDERSTORMS MAY ACCOMPANY THE FRONT BUT
NOT ENOUGH CONFIDENCE IN COVERAGE AT THIS POINT TO INCLUDE IN TAF.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z FRIDAY...
FORECAST CONFIDENCE...HIGH.
ALTERNATE SCENARIOS: NONE
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z FRIDAY...IFR VISIBILITY MAY BE POSSIBLE IN STRONGER
STORMS LATE AFTERNOON AND EVENING FRIDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/TAX
NEAR TERM...50/TAX
SHORT TERM...TRM
LONG TERM...26
AVIATION...50/TAX
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1043 AM EDT THU MAR 29 2012
.SYNOPSIS...
HIGH PRESSURE PASSES TO THE NORTH LATE TODAY. LOW PRESSURE BRINGS
A WARM FRONT...THEN A COLD FRONT FRIDAY...THE LATTER WITH MORE
STORMS LATE FRIDAY. HIGH PRESSURE CROSSES SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030 AM UPDATE...BUMPED UP SKY COVER ACROSS ROUGHLY NORTHERN THIRD
OF FORECAST AREA. LOW-LEVEL STRATOCU OVER NORTHEAST OHIO CURRENTLY
PUSHING SOUTHWARD...ALONG WITH SOME LOW-LEVEL CU FORMING ACROSS NW
ZONES WARRANTED A BUMP IN SKY COVER TO MOSTLY SUNNY/PARTLY CLOUDY
PERHAPS DURING THE MID/LATE MORNING HOURS. THESE CLOUDS SHOULD
DISSIPATE DURING THE AFTERNOON HOURS. OTHERWISE...NO SIGNIFICANT
CHANGES MADE.
PREVIOUS DISCUSSION...LATEST IR IMAGERY HAS CLEAR SKY FOR ENTIRE CWA
CURRENTLY. HOWEVER...LOW LEVEL MOISTURE ASSOCIATED WITH THE POST-FRONTAL
TROF TO OUR NORTH IS OOZING SOUTHWARD AND SHOULD BEGIN TO POOL UP AGAINST
THE NRN WV MOUNTAINS EVENTUALLY DEVELOPING OROGRAPHICALLY INDUCED CLOUDS
AND NOTHING MORE.
CURRENT WV IMAGERY SHOWING COPIOUS DRY AIR DIRECTLY OVER OUR
AREA...AND THIS IS HANDLED WELL IN THE RUC H5-H7 LAYER.
THIS...COMBINED WITH MORNING DAYTIME HEATING...SHOULD WORK TO
QUICKLY DISSIPATE THE LOW LEVEL CLOUDS THAT ARE CONTINUING TO
DEVELOP IN THE NRN WV MNTS CURRENTLY. OVERALL...A PLEASANT DAY IS ON
TAP WITH CLEAR SKY CONDITIONS AND TEMPERATURES RETURNING A LITTLE
CLOSER TO SEASONAL AVERAGE.
CLEAR SKY AND MODEST CAA EARLY TONIGHT WILL WORK TO BRING
TEMPERATURES DOWN IN THE NRN ZONES NEARING THE POINT OF FROST
DEVELOPMENT. AT THE SAME TIME...NEAR TERM MODELS HAVE BEEN SPEEDING
UP THE TIMING OF THE APPROACH OF THE NEXT WARM FRONT. 06Z NAM AND
03Z SREF MEAN HAS THETA-E GRADIENT EAST OF THE TUG FORK VALLEY AND
THE TRI-STATE AREA BY 12Z FRI. WITH THIS IN MIND...WILL NOT BE
ISSUING FROST ADVY FOR NRN ZONES WITH THIS ISSUANCE...BUT WILL
MENTION POSSIBILITY FOR PATCHY FROST IN WX GRIDS AND ZONES.
FOR REASONS MENTIONED ABOVE...HAVE SPED UP TIMING OF THE ONSET OF
CLOUD COVER AND POPS ASSOCIATED WITH WARM FRONT TOWARDS THE END OF
THE NEAR TERM. BY MID-DAY FRI...CWA SHOULD BE FIRMLY PLANTED IN THE
WARM SECTOR WITH TEMPS REBOUNDING QUICKLY.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
SHIFTED SAT SYSTEM TO FRI YESTERDAY...RESULTING IN AN ENTIRELY DRY
WEEKEND. NOW IT LOOKS LIKE WE MAY BE TAKING BACK SUNDAY.
FRI SYSTEM REMAINS ON TRACK AS EVEN ECMWF HAS COME AROUND TO THE
FASTER TIMING. NW-SE ORIENTED WARM FRONT...THEN THE WARM
SECTOR...THEN NE-SW ORIENTED COLD FRONT MARCH ACROSS IN A NICE
CLASSICAL SYNOPTIC SETUP. WORRIED PRECIPITATION COULD BREAK OUT
ALONG THE WARM FRONT FRI MORNING...WHICH IS MARKED BY WELL DEFINED
THETA E GRADIENT. WE COULD EVEN SEE A CONVECTIVE COMPLEX SIMILAR TO
WHAT IS GOING ON THIS MORNING OVER THE MIDWEST ALONG SAID GRADIENT.
AFTER A BREAK IN THE WARM SECTOR EARLY FRI AFTERNOON...SHOWERS AND
STRONG THUNDERSTORMS FIRE UP AHEAD OF THE COLD FRONT LATE FRI
AFTERNOON AND TRAVERSE THE AREA FROM NW TO SE THROUGH FRI EVENING.
THE THERMODYNAMIC AND KINEMATIC PARAMETERS LOOK SIMILAR TO THOSE
AHEAD OF THE COLD FRONT THAT TRAVERSED THE AREA LAST NIGHT...SO A
SIMILAR HAIL AND WIND THREAT IS ANTICIPATED. INSTABILITY LOOKS TO
BE GREATEST AS ONE MOVES SW ALONG FRONT...CLOSE TO MOISTURE SOURCE.
INDEED...SPC CONTINUES TO PEG WESTERN PORTIONS OF THE AREA FOR THE
SLIGHT RISK.
WILL KEEP HWO HAZARD AND RWS IMPACT FOR SEVERE THUNDERSTORMS
EMPHASIZING THE W.
COLD ADVECTION IN THE WAKE OF THE SYSTEM SAT WILL BE ACCOMPANIED BY
DEEPER MOISTURE COMPARED WITH TODAY...ALONG WITH SOME SUB FREEZING
LOW LEVEL TEMPERATURES...SO OPTED TO LEAVE SHOWER CHANCE IN THE
MOUNTAINS. ALSO LOTS OF STRATOCU ATOP MIXED LAYER THROUGHOUT THE
AREA.
THE CONUNDRUM SUNDAY IS A NW FLOW WARM ADVECTION FEATURE THAT MAY
AGAIN MATERIALIZE AS A CONVECTIVE COMPLEX. FOR NOW...JUST ADDED THE
SLIGHT CHANCE FOR SHOWERS IN CONCERT WITH NEIGHBORS TO THE N AND W.
THANKS ILN AND PBZ FOR COORD ON THIS CHANGE. WOULD NOT BE SURPRISED
TO SEE THIS BLOW UP INTO SOMETHING MORE IF THE GENERAL PATTERN
EVOLUTION HOLDS.
USED A CACOPHONY OF GUIDANCE BLENDS TO ARRIVE AT TEMPERATURES.
TRIED TO RAISE HIGHS FRI IN THE WARM SECTOR...ESPECIALLY SOUTHERN
AND CENTRAL PORTIONS OF THE AREA. LOWERED A LITTLE FRI NT THROUGH
SAT NT ALTHOUGH NAM12 SUGGESTS IT WILL BE EVEN COLDER. TRENDED
TEMPERATURES UP JUST A BIT SUN AND SUN NT.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
STILL HAVE A DEGREE OF UNCERTAINTY TO THE EXTENDED...PER
USUAL...RESULTING IN A BLEND COMING FROM HPC IN THE FORECAST GRIDS.
DID ADJUST SOME OF THE SKIES DURING THE EXTENDED PERIOD TO BETTER
MATCH UP WITH THE POPS IN THE FORECAST. OVERALL...LOOKING AT MORE
SEASONAL TEMPERATURES...AND DESPITE A COUPLE OF SYSTEMS IN THE LONG
TERM MODELS...OVERALL PRECIPITATION TO COME IN ON THE LOWER SIDE. DO
HAVE A COUPLE OF NIGHTS TOWARDS THE END OF THE PERIOD WHERE WE MAY
NEED TO BE CAREFUL OF FROST AND FREEZE GIVEN THE TRENDS IN THAT TIME
PERIOD WITH A DEEP TROUGH LIFTING OUT AND THE SKY TRYING TO
CLEAR...BUT AS OF NOW...NOTHING TO BE MENTIONED IN THE HWO OR RWS.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
00Z THURSDAY THRU 00Z FRIDAY...
HIGH PRESSURE CURRENTLY BUILDING IN. GENERALLY VFR WITH MOSTLY CLEAR
CONDITIONS. LIGHT SURFACE FLOW OUT OF THE NORTH WILL BACK AROUND
TO THE SOUTH AND WEST TONIGHT. HIGH CLOUDS WILL BEGIN TO STREAM
IN TONIGHT AHEAD OF A WARM FRONT FOR FRIDAY...BUT VFR WILL REMAIN
THE PREVAILING CATEGORY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY...
FORECAST CONFIDENCE...HIGH.
ALTERNATE SCENARIOS: NONE
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z FRIDAY...
NO IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/TAX
NEAR TERM...50/TAX
SHORT TERM...TRM
LONG TERM...26
AVIATION...TAX
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
622 AM EDT THU MAR 29 2012
.SYNOPSIS...
HIGH PRESSURE PASSES TO THE NORTH LATE TODAY. LOW PRESSURE BRINGS
A WARM FRONT...THEN A COLD FRONT FRIDAY...THE LATTER WITH MORE
STORMS LATE FRIDAY. HIGH PRESSURE CROSSES SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST IR IMAGERY HAS CLEAR SKY FOR ENTIRE CWA CURRENTLY.
HOWEVER...LOW LEVEL MOISTURE ASSOCIATED WITH THE POST-FRONTAL TROF
TO OUR NORTH IS OOZING SOUTHWARD AND SHOULD BEGIN TO POOL UP AGAINST
THE NRN WV MOUNTAINS EVENTUALLY DEVELOPING OROGRAPHICALLY INDUCED
CLOUDS AND NOTHING MORE.
CURRENT WV IMAGERY SHOWING COPIOUS DRY AIR DIRECTLY OVER OUR
AREA...AND THIS IS HANDLED WELL IN THE RUC H5-H7 LAYER.
THIS...COMBINED WITH MORNING DAYTIME HEATING...SHOULD WORK TO
QUICKLY DISSIPATE THE LOW LEVEL CLOUDS THAT ARE CONTINUING TO
DEVELOP IN THE NRN WV MNTS CURRENTLY. OVERALL...A PLEASANT DAY IS ON
TAP WITH CLEAR SKY CONDITIONS AND TEMPERATURES RETURNING A LITTLE
CLOSER TO SEASONAL AVERAGE.
CLEAR SKY AND MODEST CAA EARLY TONIGHT WILL WORK TO BRING
TEMPERATURES DOWN IN THE NRN ZONES NEARING THE POINT OF FROST
DEVELOPMENT. AT THE SAME TIME...NEAR TERM MODELS HAVE BEEN SPEEDING
UP THE TIMING OF THE APPROACH OF THE NEXT WARM FRONT. 06Z NAM AND
03Z SREF MEAN HAS THETA-E GRADIENT EAST OF THE TUG FORK VALLEY AND
THE TRI-STATE AREA BY 12Z FRI. WITH THIS IN MIND...WILL NOT BE
ISSUING FROST ADVY FOR NRN ZONES WITH THIS ISSUANCE...BUT WILL
MENTION POSSIBILITY FOR PATCHY FROST IN WX GRIDS AND ZONES.
FOR REASONS MENTIONED ABOVE...HAVE SPED UP TIMING OF THE ONSET OF
CLOUD COVER AND POPS ASSOCIATED WITH WARM FRONT TOWARDS THE END OF
THE NEAR TERM. BY MID-DAY FRI...CWA SHOULD BE FIRMLY PLANTED IN THE
WARM SECTOR WITH TEMPS REBOUNDING QUICKLY.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
SHIFTED SAT SYSTEM TO FRI YESTERDAY...RESULTING IN AN ENTIRELY DRY
WEEKEND. NOW IT LOOKS LIKE WE MAY BE TAKING BACK SUNDAY.
FRI SYSTEM REMAINS ON TRACK AS EVEN ECMWF HAS COME AROUND TO THE
FASTER TIMING. NW-SE ORIENTED WARM FRONT...THEN THE WARM
SECTOR...THEN NE-SW ORIENTED COLD FRONT MARCH ACROSS IN A NICE
CLASSICAL SYNOPTIC SETUP. WORRIED PRECIPITATION COULD BREAK OUT
ALONG THE WARM FRONT FRI MORNING...WHICH IS MARKED BY WELL DEFINED
THETA E GRADIENT. WE COULD EVEN SEE A CONVECTIVE COMPLEX SIMILAR TO
WHAT IS GOING ON THIS MORNING OVER THE MIDWEST ALONG SAID GRADIENT.
AFTER A BREAK IN THE WARM SECTOR EARLY FRI AFTERNOON...SHOWERS AND
STRONG THUNDERSTORMS FIRE UP AHEAD OF THE COLD FRONT LATE FRI
AFTERNOON AND TRAVERSE THE AREA FROM NW TO SE THROUGH FRI EVENING.
THE THERMODYNAMIC AND KINEMATIC PARAMETERS LOOK SIMILAR TO THOSE
AHEAD OF THE COLD FRONT THAT TRAVERSED THE AREA LAST NIGHT...SO A
SIMILAR HAIL AND WIND THREAT IS ANTICIPATED. INSTABILITY LOOKS TO
BE GREATEST AS ONE MOVES SW ALONG FRONT...CLOSE TO MOISTURE SOURCE.
INDEED...SPC CONTINUES TO PEG WESTERN PORTIONS OF THE AREA FOR THE
SLIGHT RISK.
WILL KEEP HWO HAZARD AND RWS IMPACT FOR SEVERE THUNDERSTORMS
EMPHASIZING THE W.
COLD ADVECTION IN THE WAKE OF THE SYSTEM SAT WILL BE ACCOMPANIED BY
DEEPER MOISTURE COMPARED WITH TODAY...ALONG WITH SOME SUB FREEZING
LOW LEVEL TEMPERATURES...SO OPTED TO LEAVE SHOWER CHANCE IN THE
MOUNTAINS. ALSO LOTS OF STRATOCU ATOP MIXED LAYER THROUGHOUT THE
AREA.
THE CONUNDRUM SUNDAY IS A NW FLOW WARM ADVECTION FEATURE THAT MAY
AGAIN MATERIALIZE AS A CONVECTIVE COMPLEX. FOR NOW...JUST ADDED THE
SLIGHT CHANCE FOR SHOWERS IN CONCERT WITH NEIGHBORS TO THE N AND W.
THANKS ILN AND PBZ FOR COORD ON THIS CHANGE. WOULD NOT BE SURPRISED
TO SEE THIS BLOW UP INTO SOMETHING MORE IF THE GENERAL PATTERN
EVOLUTION HOLDS.
USED A CACOPHONY OF GUIDANCE BLENDS TO ARRIVE AT TEMPERATURES.
TRIED TO RAISE HIGHS FRI IN THE WARM SECTOR...ESPECIALLY SOUTHERN
AND CENTRAL PORTIONS OF THE AREA. LOWERED A LITTLE FRI NT THROUGH
SAT NT ALTHOUGH NAM12 SUGGESTS IT WILL BE EVEN COLDER. TRENDED
TEMPERATURES UP JUST A BIT SUN AND SUN NT.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
STILL HAVE A DEGREE OF UNCERTAINTY TO THE EXTENDED...PER
USUAL...RESULTING IN A BLEND COMING FROM HPC IN THE FORECAST GRIDS.
DID ADJUST SOME OF THE SKIES DURING THE EXTENDED PERIOD TO BETTER
MATCH UP WITH THE POPS IN THE FORECAST. OVERALL...LOOKING AT MORE
SEASONAL TEMPERATURES...AND DESPITE A COUPLE OF SYSTEMS IN THE LONG
TERM MODELS...OVERALL PRECIPITATION TO COME IN ON THE LOWER SIDE. DO
HAVE A COUPLE OF NIGHTS TOWARDS THE END OF THE PERIOD WHERE WE MAY
NEED TO BE CAREFUL OF FROST AND FREEZE GIVEN THE TRENDS IN THAT TIME
PERIOD WITH A DEEP TROUGH LIFTING OUT AND THE SKY TRYING TO
CLEAR...BUT AS OF NOW...NOTHING TO BE MENTIONED IN THE HWO OR RWS.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
00Z THURSDAY THRU 00Z FRIDAY...
HIGH PRESSURE CURRENTLY BUILDING IN. GENERALLY VFR WITH MOSTLY CLEAR
CONDITIONS. LIGHT SURFACE FLOW OUT OF THE NORTH WILL BACK AROUND
TO THE SOUTH AND WEST TONIGHT. HIGH CLOUDS WILL BEGIN TO STREAM
IN TONIGHT AHEAD OF A WARM FRONT FOR FRIDAY...BUT VFR WILL REMAIN
THE PREVAILING CATEGORY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY...
FORECAST CONFIDENCE...HIGH.
ALTERNATE SCENARIOS: NONE
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H L H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z FRIDAY...
NO IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/TAX
NEAR TERM...TAX
SHORT TERM...TRM
LONG TERM...26
AVIATION...TAX
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
526 AM EDT THU MAR 29 2012
.SYNOPSIS...
HIGH PRESSURE PASSES TO THE NORTH LATE TODAY. LOW PRESSURE BRINGS
A WARM FRONT...THEN A COLD FRONT FRIDAY...THE LATTER WITH MORE
STORMS LATE FRIDAY. HIGH PRESSURE CROSSES SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST IR IMAGERY HAS CLEAR SKY FOR ENTIRE CWA CURRENTLY.
HOWEVER...LOW LEVEL MOISTURE ASSOCIATED WITH THE POST-FRONTAL TROF
TO OUR NORTH IS OOZING SOUTHWARD AND SHOULD BEGIN TO POOL UP AGAINST
THE NRN WV MOUNTAINS EVENTUALLY DEVELOPING OROGRAPHICALLY INDUCED
CLOUDS AND NOTHING MORE.
CURRENT WV IMAGERY SHOWING COPIOUS DRY AIR DIRECTLY OVER OUR
AREA...AND THIS IS HANDLED WELL IN THE RUC H5-H7 LAYER.
THIS...COMBINED WITH MORNING DAYTIME HEATING...SHOULD WORK TO
QUICKLY DISSIPATE THE LOW LEVEL CLOUDS THAT ARE CONTINUING TO
DEVELOP IN THE NRN WV MNTS CURRENTLY. OVERALL...A PLEASANT DAY IS ON
TAP WITH CLEAR SKY CONDITIONS AND TEMPERATURES RETURNING A LITTLE
CLOSER TO SEASONAL AVERAGE.
CLEAR SKY AND MODEST CAA EARLY TONIGHT WILL WORK TO BRING
TEMPERATURES DOWN IN THE NRN ZONES NEARING THE POINT OF FROST
DEVELOPMENT. AT THE SAME TIME...NEAR TERM MODELS HAVE BEEN SPEEDING
UP THE TIMING OF THE APPROACH OF THE NEXT WARM FRONT. 06Z NAM AND
03Z SREF MEAN HAS THETA-E GRADIENT EAST OF THE TUG FORK VALLEY AND
THE TRI-STATE AREA BY 12Z FRI. WITH THIS IN MIND...WILL NOT BE
ISSUING FROST ADVY FOR NRN ZONES WITH THIS ISSUANCE...BUT WILL
MENTION POSSIBILITY FOR PATCHY FROST IN WX GRIDS AND ZONES.
FOR REASONS MENTIONED ABOVE...HAVE SPED UP TIMING OF THE ONSET OF
CLOUD COVER AND POPS ASSOCIATED WITH WARM FRONT TOWARDS THE END OF
THE NEAR TERM. BY MID-DAY FRI...CWA SHOULD BE FIRMLY PLANTED IN THE
WARM SECTOR WITH TEMPS REBOUNDING QUICKLY.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
SHIFTED SAT SYSTEM TO FRI YESTERDAY...RESULTING IN AN ENTIRELY DRY
WEEKEND. NOW IT LOOKS LIKE WE MAY BE TAKING BACK SUNDAY.
FRI SYSTEM REMAINS ON TRACK AS EVEN ECMWF HAS COME AROUND TO THE
FASTER TIMING. NW-SE ORIENTED WARM FRONT...THEN THE WARM
SECTOR...THEN NE-SW ORIENTED COLD FRONT MARCH ACROSS IN A NICE
CLASSICAL SYNOPTIC SETUP. WORRIED PRECIPITATION COULD BREAK OUT
ALONG THE WARM FRONT FRI MORNING...WHICH IS MARKED BY WELL DEFINED
THETA E GRADIENT. WE COULD EVEN SEE A CONVECTIVE COMPLEX SIMILAR TO
WHAT IS GOING ON THIS MORNING OVER THE MIDWEST ALONG SAID GRADIENT.
AFTER A BREAK IN THE WARM SECTOR EARLY FRI AFTERNOON...SHOWERS AND
STRONG THUNDERSTORMS FIRE UP AHEAD OF THE COLD FRONT LATE FRI
AFTERNOON AND TRAVERSE THE AREA FROM NW TO SE THROUGH FRI EVENING.
THE THERMODYNAMIC AND KINEMATIC PARAMETERS LOOK SIMILAR TO THOSE
AHEAD OF THE COLD FRONT THAT TRAVERSED THE AREA LAST NIGHT...SO A
SIMILAR HAIL AND WIND THREAT IS ANTICIPATED. INSTABILITY LOOKS TO
BE GREATEST AS ONE MOVES SW ALONG FRONT...CLOSE TO MOISTURE SOURCE.
INDEED...SPC CONTINUES TO PEG WESTERN PORTIONS OF THE AREA FOR THE
SLIGHT RISK.
WILL KEEP HWO HAZARD AND RWS IMPACT FOR SEVERE THUNDERSTORMS
EMPHASIZING THE W.
COLD ADVECTION IN THE WAKE OF THE SYSTEM SAT WILL BE ACCOMPANIED BY
DEEPER MOISTURE COMPARED WITH TODAY...ALONG WITH SOME SUB FREEZING
LOW LEVEL TEMPERATURES...SO OPTED TO LEAVE SHOWER CHANCE IN THE
MOUNTAINS. ALSO LOTS OF STRATOCU ATOP MIXED LAYER THROUGHOUT THE
AREA.
THE CONUNDRUM SUNDAY IS A NW FLOW WARM ADVECTION FEATURE THAT MAY
AGAIN MATERIALIZE AS A CONVECTIVE COMPLEX. FOR NOW...JUST ADDED THE
SLIGHT CHANCE FOR SHOWERS IN CONCERT WITH NEIGHBORS TO THE N AND W.
THANKS ILN AND PBZ FOR COORD ON THIS CHANGE. WOULD NOT BE SURPRISED
TO SEE THIS BLOW UP INTO SOMETHING MORE IF THE GENERAL PATTERN
EVOLUTION HOLDS.
USED A CACOPHONY OF GUIDANCE BLENDS TO ARRIVE AT TEMPERATURES.
TRIED TO RAISE HIGHS FRI IN THE WARM SECTOR...ESPECIALLY SOUTHERN
AND CENTRAL PORTIONS OF THE AREA. LOWERED A LITTLE FRI NT THROUGH
SAT NT ALTHOUGH NAM12 SUGGESTS IT WILL BE EVEN COLDER. TRENDED
TEMPERATURES UP JUST A BIT SUN AND SUN NT.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
STILL HAVE A DEGREE OF UNCERTAINTY TO THE EXTENDED...PER
USUAL...RESULTING IN A BLEND COMING FROM HPC IN THE FORECAST GRIDS.
DID ADJUST SOME OF THE SKIES DURING THE EXTENDED PERIOD TO BETTER
MATCH UP WITH THE POPS IN THE FORECAST. OVERALL...LOOKING AT MORE
SEASONAL TEMPERATURES...AND DESPITE A COUPLE OF SYSTEMS IN THE LONG
TERM MODELS...OVERALL PRECIPITATION TO COME IN ON THE LOWER SIDE. DO
HAVE A COUPLE OF NIGHTS TOWARDS THE END OF THE PERIOD WHERE WE MAY
NEED TO BE CAREFUL OF FROST AND FREEZE GIVEN THE TRENDS IN THAT TIME
PERIOD WITH A DEEP TROUGH LIFTING OUT AND THE SKY TRYING TO
CLEAR...BUT AS OF NOW...NOTHING TO BE MENTIONED IN THE HWO OR RWS.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
00Z THURSDAY THRU 00Z FRIDAY...
HIGH PRESSURE BUILDS IN THIS MORNING. GENERALLY VFR WITH MOSTLY
CLEAR CONDITIONS. SOME LOW LEVEL MOISTURE SNEAKS BACK IN LATE
TONIGHT AND THURSDAY IN THE NORTH AND EAST...BUT EXPECT VFR SCT-BKN
CLOUDS TO PREVAIL THERE THROUGH 00Z THURSDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY...
FORECAST CONFIDENCE...HIGH.
ALTERNATE SCENARIOS: NONE
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE THU 03/29/12
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z FRIDAY...
NO IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/TAX
NEAR TERM...TAX
SHORT TERM...TRM
LONG TERM...26
AVIATION...TAX
AREA FORECAST DISCUSSION
NWS NORMAN OK
328 PM CDT THU MAR 29 2012
.DISCUSSION...
WARM AND HUMID CONDITIONS WILL CONTINUE FOR THE NEXT SEVERAL DAYS
WITH A FEW OPPORTUNITIES FOR WIDELY SCATTERED SHOWERS AND STORMS.
RECENT HRRR RUNS/NAM12/GFS SIMILAR WITH DEVELOPMENT OF STORMS
ACROSS NORTHWEST OKLAHOMA LATE THIS AFTERNOON INTO THE EARLY
EVENING. STEEP LAPSE RATES AND FAIRLY WEAK MID-LEVEL FLOW WILL
FAVOR LARGE HAIL AND DAMAGING WINDS WITH THE STRONGER STORMS.
LOW AMPLITUDE WAVE WILL PROVIDE SOME SUPPORT...BUT STORM INTENSITY
SHOULD DECREASE BY MID EVENING.
A WEAK SURFACE BOUNDARY AND UPPER WAVE MAY PROVIDE ENOUGH LIFT
FOR ISOLATED/WIDELY SCATTERED SHOWERS AND STORMS MAINLY IN THE
LATE AFTERNOON/EARLY EVENING FRIDAY. OVERALL COVERAGE AND
ORGANIZATION APPEARS LOW.
MAINLY DRY CONDITIONS ARE EXPECTED FOR AT LEAST THE FIRST HALF
OF THE WEEKEND WITH LOW AMPLITUDE RIDGE OVER THE CENTRAL US.
MODELS BEGIN TO DIVERGE ON STRENGTH AND OVERALL TIMING WITH
ANOTHER TROUGH THAT IS FORECAST TO APPROACH THE SOUTHERN PLAINS
LATE SUNDAY INTO MONDAY. EC MODEL LESS AMPLIFIED AND FASTER WHICH
MATCHES CURRENT FORECAST. FOR NOW WILL FOLLOW FASTER SOLUTION
WHICH WILL PLACE BETTER CHANCES FOR STORM OVER EASTERN 1/3 OF
OKLAHOMA.
DRYLINE/COLD FRONT MAY BE DELAYED ENOUGH ON SUNDAY THAT HUMIDITY
LEVELS WILL REMAIN ABOVE 20-25 PERCENT ACROSS FAR WESTERN OKLAHOMA.
THIS SYSTEM WILL BRING IN SOMEWHAT COOLER AND DRIER AIR BY
MONDAY/TUESDAY OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 60 82 60 83 / 10 30 20 10
HOBART OK 58 85 57 83 / 20 20 20 0
WICHITA FALLS TX 60 88 59 87 / 10 30 20 0
GAGE OK 50 80 51 85 / 20 10 10 0
PONCA CITY OK 58 81 57 84 / 30 10 10 10
DURANT OK 61 81 60 83 / 10 30 20 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1110 PM CDT WED MAR 28 2012
.DISCUSSION.../ISSUED AT 920 PM CDT/
SEEING SOME LIGHT SHOWERS SHOWING UP ON RADAR ACROSS EASTERN
NEBRASKA AND PORTIONS OF IOWA ASSOCIATED WITH AN AREA OF THETAE
ADVECTION ON THE NOSE OF AN INCREASING LOW LEVEL JET. THIS AREA WILL
CONTINUE TO MOVE NORTH...REACHING SIOUX CITY BY 6Z AND SIOUX FALLS
BY 9Z. TOUGH TO SAY WHETHER WE GET MUCH OUT OF THIS THROUGH 12Z.
BEST CHANCE OF SEEING A SHOWER WILL BE RIGHT ALONG THE ELEVATED
INSTABILITY BOUNDARY....WHICH ACCORDING TO THE NAM WILL RUN FROM
SIOUX CITY NORTHWEST THROUGH SIOUX FALLS AND HURON. ELEVATED CAPE
ONLY EXPECTED TO BE A FEW HUNDRED J/KG. THUS NOT EXPECTING ANYTHING
SIGNIFICANT THROUGH 12Z...IN FACT WE MIGHT NOT EVEN BE ABLE TO GET
ANY THUNDER OUT OF THESE SHOWERS. FURTHER WEST...MUCAPE WILL BE
HIGHER...BUT THE COMBINATION OF LESS LOW LEVEL LIFT AND WARMER TEMPS
ALOFT ACTING AS A CAP...SHOULD PREVENT ANYTHING FROM FORMING THERE.
LATEST HRRR IS FURTHER SOUTHWEST WITH THE BEST LOW LEVEL MOISTURE
RETURN AND ELEVATED CAPE...AND KEEPS OUR ENTIRE CWA DRY THROUGH 12Z.
FOR NOW...DECIDED TO KEEP POPS IN THROUGH THE OVERNIGHT WITH THE
NAM...GFS AND SREF SHOWING SOME SPOTTY SHOWERS. /CHENARD
PREVIOUS DISCUSSION...
SURFACE RIDGE NOSING THROUGH MINNESOTA WILL BEGIN TO SLIP EAST WITH
AN INCREASING EAST TO SOUTHEAST FLOW ACROSS THE AREA. NOT MUCH FOR
IMMEDIATE MOISTURE RETURN...BUT 50S TO LOWER 60S DEWPOINTS ARE
GATHERING ACROSS KANSAS...WITH ELEVATED CONVECTION DEVELOPING ACROSS
SOUTHERN NEBRASKA. MORE SURFACE BASED CONVECTION IS EXPECTED TO
DEVELOP ALONG THE SURFACE TO 925 HPA MOISTURE DISCONTINUITY THIS
EVENING...AND THIS WILL LIKELY DISRUPT THE DEVELOPMENT OF THE LOW
LEVEL JET SOMEWHAT. HOWEVER...BY LATE NIGHT...SOME ELEVATED CAPES
FROM 800 HPA ON THE ORDER OF 400-600 J/KG WITH CAP WEAK ON ORDER OF
25 J/KG OR LESS...BUT DISTRIBUTED OVER ABOUT A 100 HPA DEEP LAYER...
SUGGESTING WILL NEED SOME APPRECIABLE FORCING TO GET ANY ELEVATED
ACTIVITY...WHICH WILL LIKELY WAIT UNTIL LOW LEVEL JET BECOMES
ESTABLISHED...ESPECIALLY TOWARD 12Z...AND USED THE GRADIENT IN
ELEVATED INSTABILITY TO DEFINE TIMING.
CONCERN IN PLACE THAT AFTER THE INITIAL ELEVATED PUSH DURING THE
EARLY TO MID MORNING HOURS...THAT MAY SEE A FAIRLY QUIET PERIOD FOR
MOST UNTIL STRONGER DYNAMIC FORCING ASSOCIATED WITH MID LEVEL WAVE
FROM THE WEST DURING THE AFTERNOON. SOME DISTRIBUTION OF
PRECIPITATION ISSUES WILL DEPEND ON DESTABILIZATION/BOUNDARY
LOCATIONS FROM MORNING ACTIVITY...BUT IN GENERAL WILL BE A BETTER
CHANCE FROM NEAR I29 AND EAST DURING THE AFTERNOON...AND ESPECIALLY
BY LATER IN THE DAY. AT THIS TIME...SEVERE WEATHER WOULD APPEAR TO
BE A FAIRLY MINIMAL THREAT WITH A LACK OF INSTABILITY...WITH
EFFECTIVE SHEAR PERHAPS INDICATING A MARGINAL ORGANIZATION/HAIL
THREAT THROUGH THE SOUTHERN TIER WITH THE AFTERNOON DEVELOPMENT.
TEMPERATURES DIFFICULT WITH UNCERTAINTY IN CONVECTIVE POTENTIAL...
BUT HEDGED TEMPS DOWN A BIT WITH EXPECTED CLOUDS/PRECIPITATION
AND FAIRLY STABLE LOW LEVEL CONDITIONS. /CHAPMAN
WINDS WILL DECREASE ON THURSDAY NIGHT ALLOWING FOR DECENT
RADIATIONAL COOLING. NOT TO THE EXTENT OF THIS MORNING BUT ENOUGH
THAT WILL LEAN ON THE COOLER GUIDANCE OR A LITTLE BELOW...WHICH
MEANS LOWS FROM THE UPPER 30S TO LOWER 40S.
FRIDAY INTO SUNDAY WILL SEE BROAD SCALE RIDGING DEVELOP WITH WARMING
TO WAY ABOVE NORMAL AGAIN...FOR FRIDAY INTO SUNDAY. HIGHS SATURDAY
MAY EXCEED 90 IN A FEW LOCATIONS IF SOMETHING CLOSER TO THE NAM/GFS
VERIFIES WHILE MID TO UPPER 80S WOULD BE THE WARMEST PER THE ECMWF.
FRIDAY AND SUNDAY STILL WAY ABOVE NORMAL BUT MORE IN THE 70S TO
LOWER 80S...ALTHOUGH NORTHWEST IOWA COULD SEE SOME MID 80S ON SUNDAY
AHEAD OF THE INCOMING FRONT. FRIDAY NIGHT WILL BE WARM WITH SOME
SOUTHERLY FLOW...BUT NOT EXCESSIVELY STRONG. SATURDAY NIGHT WILL BE
VERY WARM WITH STRONGER SOUTHERLY FLOW. LOOKING AT LOWS IN THE MID
TO UPPER 50S SATURDAY NIGHT.
IN THE LATTER PERIODS(SUN/WED)...MODELS STILL IN AGREEMENT WITH
BRINGING A WAVE THROUGH ON MONDAY BUT STILL DIFFER ON STRENGTH AND
PLACEMENT QUITE A BIT. THIS TIME AROUND MODELS ARE A LITTLE LESS
COLD WHICH IS ABOUT THE ONLY TREND TO GRAB ON TO. MOISTURE STILL
LIMITED ON SUNDAY AFTERNOON/SUNDAY NIGHT SO WILL MAINTAIN A CHANCE
FOR THUNDERSTORMS BUT THEY MIGHT BE HARD TO COME BY IF MODELS DO NOT
BEGIN TO INCREASE MOISTURE A LITTLE MORE. OTHERWISE...WHILE COLDER
DURING THIS TIME FRAME STILL LOOKING AT ABOVE NORMAL TEMPERATURES.
LOOKING AT HIGHS ON MONDAY...TUESDAY AND WEDNESDAY IN THE 50S WITH
LOWS GENERALLY IN THE 30S. NO MAJOR CHANCES FOR PRECIPITATION DURING
THIS TIME.
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
VFR CONDITIONS WILL BE PREVALENT FOR THE REST OF THE NIGHT. THERE IS
STILL A CHANCE THAT A FEW SHOWERS OR THUNDERSTORMS WILL MAKE IT AS
FAR NORTH AS SIOUX CITY AFTER MIDNIGHT TONIGHT. HOWEVER ELEVATED
CONDITIONS ARE MUCH MORE STABLE IN OUR AREA AS OPPOSED TO THE SOUTH.
ON THURSDAY...MORE RAINFALL IS EXPECTED WITH SHOWERS AND POSSIBLE
EMBEDDED THUNDERTORMS. RIGHT NOW...IT APPEARS THE BEST CHANCES FOR
THUNDERSTORMS WILL BE CONFINED TO THE AFTERNOON HOURS IN NORTHWEST
IOWA AHEAD OF THE SURFACE WIND SHIFT. LEFT EXPLICIT THUNDERSTORM
MENTION OUT OF THE KFSD AND KHON TAF SITES...AS STABILITY INCREASES
TO THE NORTH AND WEST OF OUR NORTHWEST IOWA ZONES. BUT STILL...
CANNOT RULE OUT SOME GENERAL THUNDER NEARLY ANYWHERE IN OUR FORECAST
AREA ON THURSDAY EMBEDDED WITH THE SHOWERS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
333 PM CDT THU MAR 29 2012
.SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...ATMOSPHERE WAS PRETTY
WORKED OVER TODAY FROM LAST NIGHT/S CONVECTION WITH REMNANT MCV
NOTED ACROSS HGX CWA. LOW CLOUD DECK HAS BEEN SLOW TO MIX OUT
ACROSS BRUSH COUNTRY...BUT IS FINALLY STARTING TO DO SO AND ALL IN
ALL ATMOSPHERE IS GRADUALLY BECOMING MORE UNSTABLE AGAIN. PATTERN
LOOKS MORE LIKE MAY THAN MARCH WITH VORT MAXES TRAVERSING ACROSS
SOUTH TX IN THE MID LEVEL FLOW PRODUCING CONTINUING CHANCES OF
SHOWERS AND THUNDERSTORMS. OVER THE PAST HOUR CONVECTION HAS BEEN
TRYING TO FIRE ALONG THE SEABREEZE AS IT MOVES INLAND. THE
COMBINATION OF AN INCREASINGLY UNSTABLE AIRMASS AND AN AXIS OF
HIGHER PWATS DRAPED FROM SW TO NE ACROSS THE COASTAL PLAINS SHOULD
ALLOW ADDITIONAL CONVECTION TO DEVELOP ALONG THE SEABREEZE THROUGH
EARLY EVENING. ATTENTION THEN TURNS TO THE WEST WHERE CONVECTION
IS CURRENTLY DEVELOPING ACROSS HIGHER TERRAIN OF OLD MEX. HIRES
MODELS PROVIDE A VARIETY OF OUTPUT WITH 4KM WRF DEVELOPING
SIGNIFICANT CONVECTION ACROSS MUCH OF S TX THIS EVENING WHILE HRRR
IS MORE OF THE ISOLATED VARIETY. HRRR INITIALIZED MUCH BETTER THAN
4KM WRF SO HAVE LEANED MORE TOWARDS ITS OUTPUT FOR TONIGHT.
TRIMMED POPS SOME FOR TONIGHT OUT WEST BUT NOT AS DRY AS HRRR
GIVEN UNCERTAINTY. ANY STORMS THAT DEVELOP MAY BRIEFLY PULSE TO
STRONG/SEVERE LEVELS BUT WIDESPREAD SEVERE WX IS NOT CURRENTLY
ANTICIPATED. TOMORROW S TX IS PROG TO BE IN BETWEEN VORT MAXES AND
SHOULD GENERALLY BE DRY ASIDE FROM ISOLATED CONVECTION DEVELOPING
FROM DAYTIME MIXING AND INTERACTIONS WITH THE SEABREEZE. STRONGER
VORT MAX PROG TO APPROACH AREA FRI NIGHT WITH GOOD
PVA...INSTABILITY...AND MOISTURE TO EXIST FOR MCS FEATURE TO
POSSIBLY DEVELOP ALONG RIO GRANDE AND MOVE WEST THROUGH THE NIGHT.
STRONG WINDS AND HAIL MAY OCCUR IF MCS DEVELOPS BUT FINER DETAILS
TO COME IN FUTURE FORECASTS. TEMPS THROUGH THE SHORT TERM PERIOD
WILL BE DEPENDENT ON IF THEY BECOME RAIN COOLED AND HOW MUCH CLOUD
COVER DEVELOPS FROM CONVECTION. FOR NOW HAVE GONE GENERALLY WITH A
MOS BLEND.
&&
.LONG TERM (SATURDAY THROUGH THURSDAY)...EXPECT NOCTURNAL MCS TO BE
MOVING OUT OF THE FORECAST AREA BY THE START OF THE EXTENDED PERIOD.
HAVE ADDED 20 POPS TO THE FAR EAST TO ACCOUNT FOR TIMING OF THE
CONVECTION POSSIBLY LASTING INTO THE SATURDAY MORNING TIME PERIOD.
EXPECT TIMING WILL BE SIMILAR TO THE CONVECTION THE PAST TWO NIGHTS.
BY SATURDAY NIGHT LOOKS LIKE ALTHOUGH THUNDERSTORMS OVER THE SIERRA
MADRE ARE POSSIBLE...THE MOVEMENT SHOULD BE QUITE DIFFERENT THAN
OTHER NIGHTS HAVE BEEN AND WILL BE. CORFIDI VECTORS AND THICKNESS
CONTOURS WOULD INDICATE AN ALMOST DUE SOUTH MOVEMENT SO HAVE OPTED
TO TAKE PRECIP WORDING OUT OF THE FORECAST FOR SATURDAY NIGHT. COLD
FRONT STILL ON TRACK FOR MONDAY...WITH RATHER IMPRESSIVE MODEL
AGREEMENT FOR FOUR DAYS OUT. TIMING IS CLOSER TO THE SLOWER ECMWF
FROM YDAY RUNS AND HAVE STUCK MAINLY WITH THE ECMWF FOR THE FORECAST
THIS AFTERNOON. PRECIP CHANCES DO NOT LOOK GREAT AT THIS TIME...WITH
SLIGHT CHANCES IN THE EAST. BEHIND THE FRONT LOOK FOR A MODEST COOL
DOWN OF 5 TO 10 DEGREES FOR THE NEXT FEW DAYS WITH DRIER CONDITIONS
AND MOSTLY CLEAR SKIES.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 67 86 68 86 68 / 20 20 30 20 10
VICTORIA 67 84 67 84 68 / 30 20 20 20 10
LAREDO 68 92 69 93 69 / 40 20 50 10 10
ALICE 68 89 66 89 68 / 30 20 40 10 10
ROCKPORT 69 82 69 80 70 / 20 20 20 20 10
COTULLA 67 86 65 88 67 / 40 20 50 10 10
KINGSVILLE 68 87 68 88 67 / 30 20 30 20 10
NAVY CORPUS 71 81 68 82 69 / 20 20 20 20 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
SHORT TERM...HART/79
LONG TERM...ZABEL/83
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
1131 AM CDT THU MAR 29 2012
.UPDATE...
AFTER A BRIEF FLIRTATION WITH MOISTURE ON THE CAPROCK THIS
MORNING...THE DRYLINE IS STARTING TO JUMP EAST. WEST TEXAS MESONET
OBS SHOW DEWPOINTS DROPPING QUICKLY ACROSS THE WEST. WINDS ARE
EVEN VEERING IN THE ROLLING PLAINS WHICH IS A BIT CONCERNING FOR
HOLDING ON TO SUFFICIENT MOISTURE FOR OUR AFTERNOON TSTM
CHANCES...BUT LATEST GUIDANCE STILL DEPICT THE WIND TO START TO BACK
ACROSS THE ROLLING PLAINS BY 21Z WHICH SHOULD PUT A QUICK STOP TO
THE DRYLINE/S EASTWARD PROGRESS. BETWEEN 21-0Z...THE QUASI-
STATIONARY DRYLINE SHOULD BE LOCATED ROUGHLY FROM HALL COUNTY TO
KENT COUNTY...BULGING SLIGHTLY EAST IN DICKENS AND MOTLEY
COUNTIES. ATMOSPHERE SHOULD BECOME NEARLY UNCAPPED DURING THIS
PERIOD WITH SFC TEMPS APPROACHING 90F. AROUND THE SAME TIME...WE
SHOULD BEGIN TO SEE INCREASING LARGE-SCALE ASCENT AS A SHORTWAVE
APPROACHES FROM THE WEST...ALTHOUGH THIS WILL BE BE PRIMARILY
FOCUSED TO OUR NORTH. CAPE-SHEAR COMBINATION WILL LIKELY SUPPORT
AN ISOLD THREAT OF SVR WIND AND HAIL ACROSS A LIMITED
AREA...MAINLY ERN HALL...CHILDRESS AND ERN COTTLE
COUNTIES...DEPENDING ON JUST WHERE EXACTLY THE DRYLINE ENDS
UP. MOST OF THE HIGH-RES GUIDANCE SUGGESTS THAT CAP WILL HOLD
UNTIL VERY LATE IN THE AFTERNOON OR POSSIBLY EARLY EVENING...ABOUT
23-01Z RANGE. IT MAY BREAK FIRST ACROSS THE ERN PANHANDLE WHERE
LOW-LVL CONVERGENCE WILL BE MAXIMIZED.
SO...EXCEPT FOR SOME MINOR ADJUSTMENTS THE BULK OF THE FCST LOOKS TO
BE ON TRACK WITH A 15-20 POPS STILL LOOKING VALID ALONG/EAST OF
THE DRYLINE.
&&
.PREV DISCUSSION... /ISSUED 641 AM CDT THU MAR 29 2012/
AVIATION...
A MODEST LOW LEVEL WIND MAXIMUM AROUND 35 KTS AT 800 FT ABOVE THE
GROUND CONTINUED OVER THE CENTRAL SOUTH PLAINS NEAR KLBB ACCORDING
TO THE HIGH RESOLUTION REESE CENTER SODAR FROM THE WEST TEXAS
MESONET. THE CURRENT RUC RUN SHIFTS THIS MAX TO THE NORTHEAST
BETWEEN 13Z AND 14Z THIS MORNING ABOUT AS MIXING OUT BEGINS.
SHALLOW LOW LEVEL MOISTURE WAS MORE NOTABLE WITH A PATCH OF
STRATUS FORMING NEAR KHOB AND THE LEADING EDGE OF A LARGE AREA OF
STRATUS NEAR KABI. SOME CHANCE THAT WE COULD SEE AN LIFR CIG FORM
NEAR EITHER KCDS OR KLBB OVER THE NEXT FEW HOURS BUT OVER-ALL RISK
SEEMS TOO LOW FOR INCLUSION IN THE TAF. WE DID HOLD ON TO MINOR
VISIBILITY RESTRICTIONS...HOWEVER...THROUGH 14Z. BY LATE MORNING
EXPECT DRIER SOUTHWEST BREEZES TO DOMINATE KLBB WHILE A DRY-LINE
WILL BE IN POSITION NEAR KCDS. APPROACH OF AN UPPER LEVEL TROUGH
LATER TODAY COULD BREAK CAP AND ALLOW HIGH-BASED THUNDERSTORMS NOT
FAR FROM KCDS. RETAINED CB MENTION AT KCDS LATER TODAY. RMCQUEEN
PREV DISCUSSION... /ISSUED 514 AM CDT THU MAR 29 2012/
SHORT TERM...
A FULL-LATITUDE UPPER LEVEL TROUGH WILL SWING EAST FROM THE ROCKIES
INTO THE NORTHERN AND CENTRAL HIGH PLAINS LATE THIS AFTERNOON AND
EVENING. SOMEWHAT ENHANCED LOW LEVEL WEST TO SOUTHWEST FLOW SHOULD
DEVELOP ON THE CAPROCK AND HELP TIGHTEN A DRY-LINE OVER THE ROLLING
PLAINS...PERHAPS DIRECTLY ADJACENT TO THE CAP-ROCK. PRIMARY UPWARDS
FORCING WILL OCCUR TO THE NORTH...BUT WE MAY SEE ENOUGH LIFT WITH A
MODESTLY UNSTABLE AIRMASS TO BREAK THE CAP AND ALLOW DEVELOPMENT OF
A FEW HIGH-BASED STORMS ALONG THE DRY-LINE. SOME THREAT FOR ENTIRE
DRY-LINE TO ERUPT BUT FORCING WEAKER HEADING SOUTHWARD AS WELL.
SEVERE THREAT FROM STORMS WILL BE HIGHEST AS WELL OVER NORTHERN
ROLLING PLAINS WITH STRONG WINDS GREATEST RISK. WE TRIMMED THUNDER
CHANCES A BIT MORE TO THE EAST WITH SOLUTIONS FAVORING THE DRY
SCENARIO ON THE CAPROCK TODAY WHILE EXPANDING LOW CHANCE MENTION
THIS EVENING OVER THE NORTHERN ROLLING PLAINS. THUNDER CHANCES WILL
DIMINISH LATER TONIGHT WHILE A COLD FRONT SHOULD SETTLE SOUTHWARD
OUT OF THE PANHANDLE INTO NORTHERN ZONES LATER TONIGHT. VERY WARM
TEMPERATURES FAVORED AGAIN TODAY WITH MINOR CHANGES. RMCQUEEN
LONG TERM...
LOW AMPLITUDE RIDGING WILL RETURN TO THE AREA ON FRIDAY BEHIND A
MINOR DISTURBANCE PASSING OVERHEAD AROUND MID-DAY. THIS RIDGING
WILL PERSIST UNTIL EARLY SUNDAY MORNING WHEN A RETURN TO ENHANCED
SOUTHWESTERLY FLOW COMES ON SUNDAY AHEAD OF A POTENT STORM SYSTEM
DIVING DOWN THE WEST COAST. GUIDANCE CONTINUES TO SLOW THE
PROGRESSION OF THE SYSTEM WHICH WILL HELP THE WIND/FIRE WEATHER
POTENTIAL TO SOME EXTENT THOUGH BOTH WIND SPEEDS AND FIRE DANGER WILL BE
ENHANCED. BY MONDAY MORNING NVA WILL SET IN WITH A RETURN TO
RIDGING FOR MID-WEEK.
QUESTION WILL BE IF THIS HAS MUCH CHANCE AT ALL AT INITIATING
CONVECTION ACROSS THE AREA FOR FRIDAY...GIVEN THE TRENDS THIS
WEEK...TSTM CHANCES REMAIN QUITE LOW...ACTUALLY...TOO LOW FOR A
MENTION IN THE GRIDS. THUS WILL CONTINUE WITH A POP FREE FORECAST
FOR THE ENTIRE EXTENDED. OF NOTE THOUGH ON FRIDAY WILL BE A WEAK
COLD FRONT WHICH IS PROGGED TO ENTER AT LEAST THE NORTHERN ZONES.
THIS WOULD UNDOUBTEDLY PLAY HAVOC WITH AFTERNOON HIGHS. THE
BOUNDARY IS TRENDING FURTHER SOUTH THAN EVIDENT FOR THE LAST FEW
NIGHTS AND THUS...WILL BLEND TEMPS DOWNWARD SOMEWHAT ACROSS THE
NORTH FRIDAY AFTERNOON. DRYLINE WILL REMAIN EAST OF THE AREA FOR
MUCH OF THE REST OF THE EXTENDED. WINDS STILL LOOK TO BE QUITE BREEZY ON
SUNDAY WITH AN ATTENDANT FIRE WEATHER THREAT DUE TO THE DRY NATURE
OF THE LOWER ATMOSPHERE. SUNDAY H7 GRADIENTS OF 60M/200NM WILL
LIKELY PUSH US INTO WIND ADVISORY TERRITORY AND IF TRENDS DO NOT
CHANGE WITH VIGOR...A RED FLAG PRODUCT AS WELL. COLD FRONT DUE IN
SUNDAY NIGHT WILL BRING GUSTY WINDS IN ITS WAKE AND THESE WINDS
MAY VERY WELL BRING ADVISORY WINDS TO THE AREA THROUGH MONDAY AS A
VERY TIGHT PRESSURE GRADIENT OVERSPREADS THE AREA. AFTER THE WINDS
DIE DOWN LATE MONDAY...QUIESCENT WEATHER RETURNS TO THE SOUTHERN
PLAINS.
FIRE WEATHER...
UPPER TROUGH PASSING EAST FROM THE ROCKIES INTO THE CENTRAL AND
NORTHER HIGH PLAINS THIS AFTERNOON AND EVENING SHOULD LEAD TO
ENHANCED DOWNWARD FORCING ACROSS CENTRAL AND WESTERN SOUTH PLAINS
WITH DEEPER MIXING INTO SOMEWHAT STRONGER WEST-SOUTHWEST FLOW ALOFT.
THIS SHOULD BE ENOUGH FOR MARGINAL WINDS TO ENHANCE FIRE WEATHER
RISK ALONG WITH VERY DRY AIRMASS AND TEMPERATURES WELL ABOVE NORMAL.
GREEN-UP RECENTLY CERTAINLY HAS LESSENED FUELS THREAT FOR MANY AREAS
CENTRAL AND EAST...PROBABLY LESS SO IN THE WEST. FIRE DANGER WAS
RATED HIGH ON WEDNESDAY AND WILL NOT BE ANY LESS TODAY. ANYWAY...
ENOUGH OF A MARGINAL RISK TODAY TO INCLUDE A FIRE DANGER STATEMENT
FOR AREAS ON THE CAP-ROCK THIS AFTERNOON AND EARLY THIS EVENING.
RMCQUEEN
DRY SURFACE CONDITIONS WILL CONTINUE THE REST OF THE WEEK LEADING TO
INCREASING FUEL VOLATILITY ACROSS THE REGION ESPECIALLY IN THE WEST
WHERE GREEN-UP HAS BEEN SLOW DUE TO A LACK OF MOISTURE. SATURDAY
MAY SEE ANOTHER RANGELAND FIRE DANGER DAY WITH MIN RH
VALUES NEAR 10 PCT. SUNDAY HAS PROSPECTS TO BE A CRITICAL FIRE
WEATHER DAY AS WINDS OF 20-30MPH COMBINE WITH MIN RH VALUES NEAR
10 PCT. H8 THERMAL RIDGE NOW PROGGED TO BE ORIENTED FROM THE BIG
BEND INTO WESTERN KANSAS WHILE H5 SPEED MAX WILL LIE ACROSS
CENTRAL NEW MEXICO. THIS POINTS TO THE MOST SIGNIFICANT THREAT
NEAR THE TX/NM STATE LINE. THE THREAT MAY PERSIST OVERNIGHT
WITH LITTLE RECOVERY AND BREEZY CONDITIONS. A COLD FRONT IS DUE IN
SUNDAY NIGHT AND WINDS BEHIND THE FRONT OF 25 TO 35 MPH MAY HAMPER
EFFORTS ON ANY FIRES WHICH MAY INITIATE. THESE WINDS LOOK TO
PERSIST WELL INTO MONDAY BEFORE SUBSIDING MONDAY NIGHT. THE
LATE WEEKEND SYSTEM CERTAINLY CONTINUES TO WARRANT CAREFUL
MONITORING.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 86 45 80 47 86 / 0 10 10 10 0
TULIA 87 47 78 51 87 / 10 10 10 10 0
PLAINVIEW 87 47 80 51 88 / 10 10 10 10 0
LEVELLAND 88 48 84 52 89 / 10 10 10 10 0
LUBBOCK 89 49 84 52 89 / 10 10 10 10 0
DENVER CITY 87 49 87 52 89 / 10 10 10 10 0
BROWNFIELD 89 50 87 53 90 / 10 10 10 10 0
CHILDRESS 91 55 82 55 89 / 20 30 10 10 0
SPUR 90 54 86 56 91 / 20 20 10 10 0
ASPERMONT 88 58 90 60 91 / 20 20 10 10 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33/93
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
641 AM CDT THU MAR 29 2012
.AVIATION...
A MODEST LOW LEVEL WIND MAXIMUM AROUND 35 KTS AT 800 FT ABOVE THE
GROUND CONTINUED OVER THE CENTRAL SOUTH PLAINS NEAR KLBB ACCORDING
TO THE HIGH RESOLUTION REESE CENTER SODAR FROM THE WEST TEXAS
MESONET. THE CURRENT RUC RUN SHIFTS THIS MAX TO THE NORTHEAST
BETWEEN 13Z AND 14Z THIS MORNING ABOUT AS MIXING OUT BEGINS.
SHALLOW LOW LEVEL MOISTURE WAS MORE NOTABLE WITH A PATCH OF
STRATUS FORMING NEAR KHOB AND THE LEADING EDGE OF A LARGE AREA OF
STRATUS NEAR KABI. SOME CHANCE THAT WE COULD SEE AN LIFR CIG FORM
NEAR EITHER KCDS OR KLBB OVER THE NEXT FEW HOURS BUT OVER-ALL RISK
SEEMS TOO LOW FOR INCLUSION IN THE TAF. WE DID HOLD ON TO MINOR
VISIBILITY RESTRICTIONS...HOWEVER...THROUGH 14Z. BY LATE MORNING
EXPECT DRIER SOUTHWEST BREEZES TO DOMINATE KLBB WHILE A DRY-LINE
WILL BE IN POSITION NEAR KCDS. APPROACH OF AN UPPER LEVEL TROUGH
LATER TODAY COULD BREAK CAP AND ALLOW HIGH-BASED THUNDERSTORMS NOT
FAR FROM KCDS. RETAINED CB MENTION AT KCDS LATER TODAY. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 514 AM CDT THU MAR 29 2012/
SHORT TERM...
A FULL-LATITUDE UPPER LEVEL TROUGH WILL SWING EAST FROM THE ROCKIES
INTO THE NORTHERN AND CENTRAL HIGH PLAINS LATE THIS AFTERNOON AND
EVENING. SOMEWHAT ENHANCED LOW LEVEL WEST TO SOUTHWEST FLOW SHOULD
DEVELOP ON THE CAPROCK AND HELP TIGHTEN A DRY-LINE OVER THE ROLLING
PLAINS...PERHAPS DIRECTLY ADJACENT TO THE CAP-ROCK. PRIMARY UPWARDS
FORCING WILL OCCUR TO THE NORTH...BUT WE MAY SEE ENOUGH LIFT WITH A
MODESTLY UNSTABLE AIRMASS TO BREAK THE CAP AND ALLOW DEVELOPMENT OF
A FEW HIGH-BASED STORMS ALONG THE DRY-LINE. SOME THREAT FOR ENTIRE
DRY-LINE TO ERUPT BUT FORCING WEAKER HEADING SOUTHWARD AS WELL.
SEVERE THREAT FROM STORMS WILL BE HIGHEST AS WELL OVER NORTHERN
ROLLING PLAINS WITH STRONG WINDS GREATEST RISK. WE TRIMMED THUNDER
CHANCES A BIT MORE TO THE EAST WITH SOLUTIONS FAVORING THE DRY
SCENARIO ON THE CAPROCK TODAY WHILE EXPANDING LOW CHANCE MENTION
THIS EVENING OVER THE NORTHERN ROLLING PLAINS. THUNDER CHANCES WILL
DIMINISH LATER TONIGHT WHILE A COLD FRONT SHOULD SETTLE SOUTHWARD
OUT OF THE PANHANDLE INTO NORTHERN ZONES LATER TONIGHT. VERY WARM
TEMPERATURES FAVORED AGAIN TODAY WITH MINOR CHANGES. RMCQUEEN
LONG TERM...
LOW AMPLITUDE RIDGING WILL RETURN TO THE AREA ON FRIDAY BEHIND A
MINOR DISTURBANCE PASSING OVERHEAD AROUND MID-DAY. THIS RIDGING
WILL PERSIST UNTIL EARLY SUNDAY MORNING WHEN A RETURN TO ENHANCED
SOUTHWESTERLY FLOW COMES ON SUNDAY AHEAD OF A POTENT STORM SYSTEM
DIVING DOWN THE WEST COAST. GUIDANCE CONTINUES TO SLOW THE
PROGRESSION OF THE SYSTEM WHICH WILL HELP THE WIND/FIRE WEATHER
POTENTIAL TO SOME EXTENT THOUGH BOTH WIND SPEEDS AND FIRE DANGER WILL BE
ENHANCED. BY MONDAY MORNING NVA WILL SET IN WITH A RETURN TO
RIDGING FOR MID-WEEK.
QUESTION WILL BE IF THIS HAS MUCH CHANCE AT ALL AT INITIATING
CONVECTION ACROSS THE AREA FOR FRIDAY...GIVEN THE TRENDS THIS
WEEK...TSTM CHANCES REMAIN QUITE LOW...ACTUALLY...TOO LOW FOR A
MENTION IN THE GRIDS. THUS WILL CONTINUE WITH A POP FREE FORECAST
FOR THE ENTIRE EXTENDED. OF NOTE THOUGH ON FRIDAY WILL BE A WEAK
COLD FRONT WHICH IS PROGGED TO ENTER AT LEAST THE NORTHERN ZONES.
THIS WOULD UNDOUBTEDLY PLAY HAVOC WITH AFTERNOON HIGHS. THE
BOUNDARY IS TRENDING FURTHER SOUTH THAN EVIDENT FOR THE LAST FEW
NIGHTS AND THUS...WILL BLEND TEMPS DOWNWARD SOMEWHAT ACROSS THE
NORTH FRIDAY AFTERNOON. DRYLINE WILL REMAIN EAST OF THE AREA FOR
MUCH OF THE REST OF THE EXTENDED. WINDS STILL LOOK TO BE QUITE BREEZY ON
SUNDAY WITH AN ATTENDANT FIRE WEATHER THREAT DUE TO THE DRY NATURE
OF THE LOWER ATMOSPHERE. SUNDAY H7 GRADIENTS OF 60M/200NM WILL
LIKELY PUSH US INTO WIND ADVISORY TERRITORY AND IF TRENDS DO NOT
CHANGE WITH VIGOR...A RED FLAG PRODUCT AS WELL. COLD FRONT DUE IN
SUNDAY NIGHT WILL BRING GUSTY WINDS IN ITS WAKE AND THESE WINDS
MAY VERY WELL BRING ADVISORY WINDS TO THE AREA THROUGH MONDAY AS A
VERY TIGHT PRESSURE GRADIENT OVERSPREADS THE AREA. AFTER THE WINDS
DIE DOWN LATE MONDAY...QUIESCENT WEATHER RETURNS TO THE SOUTHERN
PLAINS.
FIRE WEATHER...
UPPER TROUGH PASSING EAST FROM THE ROCKIES INTO THE CENTRAL AND
NORTHER HIGH PLAINS THIS AFTERNOON AND EVENING SHOULD LEAD TO
ENHANCED DOWNWARD FORCING ACROSS CENTRAL AND WESTERN SOUTH PLAINS
WITH DEEPER MIXING INTO SOMEWHAT STRONGER WEST-SOUTHWEST FLOW ALOFT.
THIS SHOULD BE ENOUGH FOR MARGINAL WINDS TO ENHANCE FIRE WEATHER
RISK ALONG WITH VERY DRY AIRMASS AND TEMPERATURES WELL ABOVE NORMAL.
GREEN-UP RECENTLY CERTAINLY HAS LESSENED FUELS THREAT FOR MANY AREAS
CENTRAL AND EAST...PROBABLY LESS SO IN THE WEST. FIRE DANGER WAS
RATED HIGH ON WEDNESDAY AND WILL NOT BE ANY LESS TODAY. ANYWAY...
ENOUGH OF A MARGINAL RISK TODAY TO INCLUDE A FIRE DANGER STATEMENT
FOR AREAS ON THE CAP-ROCK THIS AFTERNOON AND EARLY THIS EVENING.
RMCQUEEN
DRY SURFACE CONDITIONS WILL CONTINUE THE REST OF THE WEEK LEADING TO
INCREASING FUEL VOLATILITY ACROSS THE REGION ESPECIALLY IN THE WEST
WHERE GREEN-UP HAS BEEN SLOW DUE TO A LACK OF MOISTURE. SATURDAY
MAY SEE ANOTHER RANGELAND FIRE DANGER DAY WITH MIN RH
VALUES NEAR 10 PCT. SUNDAY HAS PROSPECTS TO BE A CRITICAL FIRE
WEATHER DAY AS WINDS OF 20-30MPH COMBINE WITH MIN RH VALUES NEAR
10 PCT. H8 THERMAL RIDGE NOW PROGGED TO BE ORIENTED FROM THE BIG
BEND INTO WESTERN KANSAS WHILE H5 SPEED MAX WILL LIE ACROSS
CENTRAL NEW MEXICO. THIS POINTS TO THE MOST SIGNIFICANT THREAT
NEAR THE TX/NM STATE LINE. THE THREAT MAY PERSIST OVERNIGHT
WITH LITTLE RECOVERY AND BREEZY CONDITIONS. A COLD FRONT IS DUE IN
SUNDAY NIGHT AND WINDS BEHIND THE FRONT OF 25 TO 35 MPH MAY HAMPER
EFFORTS ON ANY FIRES WHICH MAY INITIATE. THESE WINDS LOOK TO
PERSIST WELL INTO MONDAY BEFORE SUBSIDING MONDAY NIGHT. THE
LATE WEEKEND SYSTEM CERTAINLY CONTINUES TO WARRANT CAREFUL
MONITORING.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 86 45 80 47 86 / 10 10 10 10 0
TULIA 87 47 78 51 87 / 10 10 10 10 0
PLAINVIEW 87 47 80 51 88 / 10 10 10 10 0
LEVELLAND 88 48 84 52 89 / 10 10 10 10 0
LUBBOCK 89 49 84 52 89 / 10 10 10 10 0
DENVER CITY 87 49 87 52 89 / 10 10 10 10 0
BROWNFIELD 89 50 87 53 90 / 10 10 10 10 0
CHILDRESS 91 55 82 55 89 / 20 30 10 10 0
SPUR 90 54 86 56 91 / 20 20 10 10 0
ASPERMONT 88 58 90 60 91 / 20 20 10 10 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/05
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1148 PM CDT WED MAR 28 2012
.AVIATION...
BREEZY SOUTHERLY WINDS UNDER A MODERATE LLJ HAVE BROUGHT BACK
IMPROVED LOW-LEVEL MOISTURE TO THE TERMINALS. AS WINDS DECREASE
AND VEER TOWARD MORNING...TEMPERATURES WILL COOL TO NEAR THE
DEWPOINT AND THIS COULD RESULT IN A LITTLE FOG/LOW CLOUD FORMATION
IN/AROUND THE TERMINALS. IF ANY SUB-VFR CONDITIONS DEVELOP THEY
SHOULD QUICKLY DIMINISH AS HEATING/MIXING COMMENCES AFTER SUNRISE.
OTHERWISE...ANOTHER WARM DAY...COUPLED WITH A DRYLINE IN THE
AREA...COULD PRODUCE HIGH-BASED CONVECTION THURSDAY
AFTN/EVNG...FAVORING LOCATIONS OFF THE CAPROCK. HENCE...HAVE
CONTINUED A CB REMARK IN THE CDS TAF AFTER 21Z.
&&
.PREV DISCUSSION... /ISSUED 825 PM CDT WED MAR 28 2012/
UPDATE...
FLAT CUMULUS FROM EARLIER HAS DISAPPEARED. LOOKS LIKE A QUIET
NIGHT AHEAD. HAVE REMOVED THUNDER MENTION FROM THE FCST...TWEAKED
SKY GRIDS...AND CLEANED UP THE HWO. NO OTHER CHANGES ATTM.
PREV DISCUSSION... /ISSUED 345 PM CDT WED MAR 28 2012/
SHORT TERM...
CONVOLUTED PATTERN IN PLACE ACROSS THE AREA GIVEN THE LARGE
CONVECTIVELY ENHANCED DISTURBANCE LOCATED TO OUR SE AND GENERAL WEAK
KINEMATICS ACROSS WEST TEXAS. THE DRYLINE HAS REMAINED FAIRLY
DIFFUSE THROUGH THE DAY ALTHOUGH AS OF 3 PM...SOME BACKING OF THE
SFC WINDS HAVE BEEN NOTED ALONG WITH SOME CUMULUS DEVELOPMENT FROM
ERN GAINES COUNTY THROUGH BRISCOE COUNTY. MEANWHILE...AN OUTFLOW BOUNDARY
FROM THE MCS IS MOVING TOWARD THE SRN ROLLING PLAINS WITH NEAR 60F
DEWPOINTS APPROACHING STONEWALL COUNTY. THERE IS LITTLE INDICATION OF A
CONVECTIVE SIGNAL IN ANY OF THE OBJECTIVE GUIDANCE FOR THE REMAINDER
OF THE AFTERNOON AND EVENING...ALTHOUGH RUC ANALYSIS SHOWS THE
ATMOSPHERE TO BE NEARLY UNCAPPED WITH ABOUT 500-1000 J/KG OF CAPE IN
MUCH OF THE ROLLING PLAINS. ALOFT...THERE IS ANOTHER WEAK WAVE
LOCATED IN NRN MX BUT THIS IS LIKELY TOO FAR REMOVED TO PROVIDE
SIGNIFICANT LIFT THIS EVENING. THUS THE ENVIRONMENT IS JUST
MARGINALLY SUPPORTIVE OF CONVECTIVE DEVELOPMENT...WITH WEAK
DRYLINE FORCING WE CAN/T RULE OUT A FEW ISOLD STORMS MAINLY ACROSS
THE SRN SPLNS AND ROLLING PLAINS. THE MAIN STORM THREAT WILL BE
STRONG DOWNDRAFT WINDS BUT IF A STORM CAN TAP INTO THE DEEPER
MOISTURE MOVING IN FROM THE SE THERE MAY BE A MARGINAL HAIL THREAT
AS WELL. THE DRYLINE SHOULD RETREAT THROUGH MOST OF THE FA
OVERNIGHT...WITH HOPEFULLY NO REPEAT OF THE NOCTURNAL MCS
INTERCEPTING OUR MOISTURE RETURN.
SOME LIGHT FOG IS AGAIN EXPECTED EARLY THU MORNING...FOLLOWED BY THE
DRYLINE MIXING INTO THE WESTERN ROLLING PLAINS BY EARLY AFTERNOON.
FCST SDNGS SHOW THAT THE AIRMASS SHOULD WARM UP NICELY IN THE DRY
AIR WITH AFTERNOON HIGHS APPROACHING 90F ACROSS THE SRN AND CENTRAL
SPLNS. GIVEN THE DEGREE OF SFC HEATING...A LITTLE MORE SHARPLY DEFINED
DRYLINE...AND INCREASED LARGE-SCALE ASCENT AS A SHORTWAVE APPROACHES
FROM THE WEST LATE IN THE DAY...WE THINK THE POTENTIAL WILL IMPROVE FOR
CONVECTIVE INITIATION ALONG THE DRYLINE THU AFTERNOON/EVE. FCST
SDNGS SHOW A DEEP DRY-ADIABATIC CONVECTIVE BOUNDARY LAYER ALONG THE
DRYLINE BY LATE AFTERNOON WITH NO INHIBITION...AND MODEST
MLCAPES...AROUND 1000 J/KG OR SO. IN ADDITION...SFC TO 6 KM SHEAR
WILL BE FAIRLY WEAK. THIS WILL LIMIT STORM ORGANIZATION...AND KEEP
STRONG WIND GUSTS AND MARGINALLY LARGE HAIL AS THE MAIN THREATS.
SOME UNCERTAINTY WITH TIMING OF THE LIFT AND DRYLINE LOCATION
PREVENT US FROM GOING HIGHER THAN SLIGHT CHANCE FOR NOW.
LONG TERM...
LARGELY UNEVENTFUL FORECAST FOR MUCH /IF NOT ALL/ OF THE EXTENDED
FORECAST AS MECHANISMS FOR ASCENT APPEAR HARD TO COME BY WITHIN
WEAK WESTERLY UPPER FLOW. EVEN THE RECENT DRYLINE IS PROGGED TO
REMAIN DIFFUSE DURING THE AFTERNOON TOMORROW AND FRIDAY AS IT
MIXES ALONG OR JUST EAST OF THE EDGE OF THE CAPROCK. VERTICAL
CIRCULATIONS WITH SUCH DRYLINES ARE GREATLY REDUCED...BUT WE HAVE
RETAINED SOME MENTION OF PRECIP OFF THE CAP THU NIGHT AS A SHALLOW
S/W TROF IN THE CENTRAL PLAINS GLANCES THE REGION. ALSO...SUBTLE
UPPER DIVERGENCE ASSOCIATED WITH AN APPROACHING UPPER WIND MAX
COULD OFFER A BIT MORE ASSISTANCE FOR ISOLATED THUNDER BEFORE
LIFT DIMINISHES LATE IN THE NIGHT. DESPITE A FRONTOLYSIZING COLD
FRONT DRIFTING SOUTH FROM THE PANHANDLE ON FRIDAY BEHIND THE S/W
TROF...SUBTLE RIDGING ALOFT THROUGHOUT THE PLAINS IS NOT BODING
WELL FOR STORM CHANCES FRIDAY AFTERNOON. NAM CONTINUES TO CONVECT
THIS DAY...ALTHOUGH THIS RECENT OVERZEALOUS NATURE OF THE MODEL
HAS NOT ENJOYED MUCH SUCCESS SO WE ARE QUITE DOUBTFUL OF ITS QPF.
APPROACH OF A PROGRESSIVE PACIFIC TROUGH BY THE WEEKEND WILL
SECURE STRONGER W-SWLY WINDS IN THE LOW-MID TROPOSPHERE.
SUBSEQUENT BOOST OF THICKNESSES SHOULD EASILY PUSH MOST AREA HIGHS
AOA 90 DEG AS THE DRYLINE MIXES NEAR OR JUST BEYOND OUR ERN
COUNTIES. TREND WITH THIS NEXT TROUGH HAS BEEN TO SLOW DOWN A BIT
AMONG THE GFS/ECMWF/GEFS MEAN AND THIS WOULD DELAY THE ARRIVAL OF
STRONGEST WINDS INTO THE PANHANDLE AND NWRN SOUTH PLAINS. BIGGEST
CHANGE HERE CONCERNS THE IMPENDING PACIFIC FRONT THAT IS NOW
PROGGED TO RID MUCH OF THE LONE STAR STATE OF GULF MOISTURE ON
MONDAY AS THE BASE OF THE TROF BECOMES -TILTED AND DIVES INTO THE
OZARKS. THIS WILL LIKELY DELAY THE RETURN OF MOISTURE MUCH LATER
THAN EARLIER FORECASTS SUGGESTED...SO A DRY START TO APRIL APPEARS
IN ORDER. TEMPS SHOULD PLUMMET BLO NORMAL FOR A CHANGE ON MONDAY
WITH GRADUAL MODIFICATION THEREAFTER.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 46 85 44 82 48 / 10 10 10 10 10
TULIA 50 87 48 85 49 / 10 20 10 10 10
PLAINVIEW 50 88 49 86 50 / 10 20 10 10 10
LEVELLAND 49 89 50 87 50 / 10 10 10 10 10
LUBBOCK 54 90 53 88 52 / 10 20 10 10 10
DENVER CITY 49 89 50 86 50 / 10 10 10 10 10
BROWNFIELD 50 90 52 86 51 / 10 20 10 10 10
CHILDRESS 58 89 56 88 54 / 10 20 20 10 10
SPUR 55 88 56 87 53 / 10 20 20 10 10
ASPERMONT 61 87 58 87 56 / 10 20 20 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
23
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1021 PM CDT FRI MAR 30 2012
.UPDATE...NO BIG CHANGES TO GOING FORECAST...EXCEPT TO TWEAK
TEMPERATURES A BIT OVERNIGHT. SOME CLEARING OF LOW CLOUDS BEHIND
SHORT WAVE CROSSING EASTERN IOWA ON WATER VAPOR LOOPS. BUT RUC
SOUNDINGS AND INCOMING 31/00Z NAM12 LAYER RH FIELDS INDICATE
CLOUDS WILL LINGER OVER SOUTHERN WISCONSIN INTO MID-LATE MORNING SATURDAY
...VERIFIED BY THE SLOW/8 KTS/EASTWARD PROGRESSION OF CLEARING
LINE ON 11U-3.9U FOG PRODUCT IMAGES.
&&
.AVIATION/06Z TAFS/...
AS MENTIONED ABOVE...LATEST RUC FORECAST SOUNDINGS AND LATEST NAM
LOW-LEVEL RELATIVE HUMIDITY FORECASTS SUPPORT IFR CIGS INTO
SATURDAY MORNING...LIFTING FROM WEST TO EAST DURING THE LATE
MORNING/VERY EARLY AFTERNOON. EXPECT 3-5SM VSBYS IN FOG TO RETURN
AS TEMPERATURES COOL A BIT MORE...THEN LIFT WITH MIXING AS SKIES BREAK.
WARM ADVECTION BRINGS VFR CLOUD DECK BACK IN SATURDAY EVENING...WITH
A CHANCE OF PRECIPITATION OVERNIGHT. ELEVATED CAPE AND STEEP LAPSE RATES
INDICATE THUNDER A POSSIBILITY...BUT WILL ONLY BRING INTO MKE TAF
FOR NOW AS OTHER LOCATIONS WILL NOT SEE PRECIPITATION UNTIL AFTER
06Z SUNDAY.
&&
.MARINE...
WITH NORTHEAST WINDS GENERALLY IN THE 5-10 KNOT RANGE...AND FETCH
TO SHORTEN AS WINDS VEER TO THE EAST...HAVE CANCELLED THE SMALL
CRAFT ADVISORY WITH THE EVENING NSH ISSUANCE.
&&
.PREV DISCUSSION... /ISSUED 302 PM CDT FRI MAR 30 2012/
VERY SHORT TERM...TONIGHT AND SATURDAY.
LOW STRATUS CLOUDS WILL LINGER THROUGH TONIGHT AND INTO EARLY
SATURDAY MORNING...GIVEN WIDESPREAD UPSTREAM LOW CLOUD DECK AND AREA
FORECAST SOUNDINGS SHOWING THIS MOIST LAYER TRAPPED UNDER INVERSION.
WINDS WILL BACK NORTHEAST ACROSS THE AREA AND WEAKEN TONIGHT...WITH
WEAKENING SURFACE PRESSURE GRADIENT AS HIGH PRESSURE SLIDES
SOUTHEAST ACROSS THE WEST CENTRAL GREAT LAKES.
CURRENT COOL TEMPERATURES WITH THE ABOVE CONDITIONS SHOULD ALLOW
LOWS TO DIP INTO THE MID TO UPPER 30S...COOLEST IN THE NORTHERN
COUNTIES. HOWEVER...NOT EXPECTING FROST DUE TO CLOUD COVER. MAY ALSO
SEE PATCHY FOG DEVELOP DURING THE NIGHT...BUT LEFT OUT OF FORECAST
DUE TO EXPECTED MODEST 3 TO 5 MILE VISIBILITY RANGE.
LOW CLOUDS SHOULD GRADUALLY MIX OUT LATER SATURDAY MORNING...WITH
PARTLY SUNNY SKIES DURING THE AFTERNOON. REMOVED POPS FOR SATURDAY
AFTERNOON...AND AREA FORECAST SOUNDINGS REMAIN FAIRLY DRY WITH NO
LIFTING MECHANISMS IN THE AREA.
WINDS SHIFT SOUTHEAST DURING THE DAY...WHICH WILL KEEP LAKESHORE
AREAS MUCH COOLER THAN WELL INLAND. MID TO UPPER 40S SEEM REASONABLE
NEAR THE SHORE...WITH LOWER TO MID 60S SOUTHWEST OF MADISON.
SHORT TERM...SATURDAY NIGHT THROUGH MONDAY.
THREAT FOR CONVECTION CONTINUES SATURDAY NIGHT INTO EARLY SUNDAY BUT
THERE ARE SOME NEGATIVES. LOW LEVEL 850-700MB Q-VECTOR CONVERGENCE
PASSES ACROSS SRN WI DURING THIS PERIOD. LOW LEVEL JET AIMED AT SRN
WI INCREASES TO 25 TO 35KTS WITH INCREASING MOISTURE FLUX
CONVERGENCE AS PRECIPITABLE WATER VALUES INCREASE ONE QUARTER TO ONE
HALF INCH. HOWEVER OPPOSED TO THIS FORCING IS SYNOPTIC SCALE WHERE
RIGHT EXIT REGION OF 300MB JET PASSES ACROSS SRN WI LATE SAT NGT.
ALSO POTENTIAL THAT THIS NIGHTTIME CONVECTION REMAINS SOUTH OF WI
INTO SUN MRNG. HENCE WL KEEP POPS LOWER THAN MET GUIDANCE...MORE IN
LINE WITH PREFERRED MAV. LOW LEVEL JET PIVOTS AWAY FROM SRN WI
LATER SUNDAY...SO WL RESTRICT SMALL CHANCES IN SOUTH TO THE MRNG.
MID LEVELS WARM TO PREVENT ANYTHING MORE THAN ISOLD CONVECTION SUN
AFTN INTO SUN NGT AS STRONGEST LOW LEVEL FORCING REMAINS WEST AND
SOUTHWEST OF SRN WI. HENCE WL CONTINUE DRY WORDING FOR NOW.
ALL SHORT TERM GUIDANCE IN REASONABLE AGREEMENT ON WEAK BOUNDARY
SLIDING ACROSS SRN WI SATURDAY NIGHT AND SUNDAY MORNING RESULTING IN
SFC WINDS TAKING ON A ELY COMPONENT FOR A TIME BEFORE VEERING TO THE
SOUTHEAST. WITH P/C SKIES MOST OF THE DAY...EXPC A LARGE HIGH
TEMPERATURE GRADIENT ACROSS SRN WI ON SUN...WITH TEMPS CLOSE TO 60
IN THE EAST...AND NEARING 80 IN THE FAR WEST. 925H TEMPS APPROACH
20C IN THE WEST IN THE AFTN. SURFACE TROUGH APPROACHES WISCONSIN
LATER MONDAY BUT MID-LEVELS REMAIN FAIRLY DRY WITH CAPPING INVERSION
REMAINING IN PLACE MOST OF THE DAY. SURFACE WARM FRONT MAY MOVE NWD
INTO PARTS OF SRN WI...BUT SOUTHEASTERLY WINDS WILL PREVENT FRONT
FROM MAKING FURTHER INROADS ACROSS ALL OF SRN WI INTO CENTRAL WI.
FOR NOW WL LOWER POPS TO SCHC ACROSS MOST OF THE CWA...AND KEEP LOW
CHC IN MY NORTHWEST. BEST CHANCE FOR PRECIP WILL BE MON NGT AS
TROUGH AND DEEPER MOISTURE MOVE ACROSS SRN WI.
LONG TERM...MONDAY NIGHT THROUGH FRIDAY.
THE BULK OF THIS PERIOD LOOKS QUIET AND DRY WITH TEMPERATURES
REMAINING MOSTLY ABOVE FOR EARLY APRIL.
MID LEVEL SHORT WAVE TROUGH EXPECTED TO EXIT WISCONSIN LATER MONDAY
NIGHT AND EARLY TUE...WITH DRIER NORTHWEST FLOW SETTING UP THROUGH
MID-WEEK. DRIER NORTHWEST FLOW DEVELOPING AS A RESULT OF UPSTREAM
LONG WAVE RIDGING BUILDING ACROSS THE CENTRAL CONUS AHEAD OF
AMPLIFYING TROUGH PUSHING SLOWLY INTO THE FAR WRN CONUS FROM THE ERN
PACIFIC. EXPECT SLOW-MOVING RIDGE TO CONTINUE TO AFFECT WI AND THE
WRN GTLAKES INTO FRIDAY AS LONG WAVE TROUGH REMAINS ANCHORED OVER
ERN NAM.
AVIATION /00Z TAFS/...EXPECT MAINLY IFR CEILINGS...WITH SOME LIFR
POSSIBLE AT TIMES...TO PERSIST THROUGH TONIGHT INTO EARLY SATURDAY
MORNING. THIS IS IN RESPONSE TO CURRENT AND UPSTREAM CEILINGS.
NORTHEAST WINDS WILL WEAKEN TONIGHT...WITH HIGH PRESSURE PASSING
NORTHEAST OF THE AREA. SOME MVFR FOG SHOULD FORM AND PERSIST
TONIGHT...GIVEN THE LOW LEVEL MOISTURE AND LIGHT WINDS. CLOUDS
SHOULD KEEP FOG FROM BECOMING TOO THICK.
WINDS VEER SOUTHEAST ON SATURDAY AS HIGH MOVES AWAY FROM THE REGION.
IFR CLOUD DECK SHOULD GRADUALLY MIX OUT IN THE LATE MORNING...WITH
VFR CONDITIONS EXPECTED THROUGH THE REST OF THE DAY.
MARINE...SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 03Z SATURDAY
ACROSS THE NEARSHORE WATERS. WEAKENING PRESSURE GRADIENT WILL ALLOW
ONSHORE WINDS TO CONTINUE TO WEAKEN INTO THE EVENING. HIGH WAVES
CURRENTLY ACROSS THE NEARSHORE WATERS SHOULD SUBSIDE AS WELL DURING
THIS TIME.
CONFIDENCE...
TONIGHT AND SATURDAY...MEDIUM.
SATURDAY NIGHT AND SUNDAY...LOW.
SUNDAY NIGHT THROUGH MONDAY NIGHT...LOW TO MEDIUM
TUESDAY THROUGH FRIDAY...MEDIUM TO HIGH.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...REM
TONIGHT/SATURDAY AND AVIATION/MARINE...WOOD
SATURDAY NIGHT THROUGH FRIDAY...MBK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
347 PM CDT THU MAR 29 2012
.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
346 PM CDT THU MAR 29 2012
AT 3 PM...A SHORT WAVE TROUGH WAS PRODUCING A CLUSTER OF
THUNDERSTORMS ACROSS SOUTHERN IOWA AND NORTHERN MISSOURI.
FURTHER TO THE WEST OVER THE CENTRAL AND NORTHERN PLAINS...
THERE WERE TWO ADDITIONAL SHORT WAVE TROUGHS. THE 29.12Z
MODELS ARE IN FAIRLY GOOD AGREEMENT THE SHORT WAVE OVER THE
NORTHERN PLAINS WILL MOVE ACROSS NORTHERN MINNESOTA AND
WESTERN ONTARIO TONIGHT. MEANWHILE THE SECOND SHORT WAVE
/CURRENTLY OVER THE CENTRAL PLAINS WILL EAST SOUTHEAST
ACROSS IOWA AND MISSOURI TONIGHT AND FRIDAY. AS A RESULT...
THE BEST FORCING WILL BE TO THE NORTH AND SOUTH OF THE
FORECAST AREA TONIGHT. EVEN THOUGH THIS WILL BE THE CASE...
THE 850 MB JET WILL FOCUS MODEST MOISTURE TRANSPORT INTO THE AREA
FOR LATE THIS EVENING AND OVERNIGHT. AS A RESULT...THE AREA WILL
SEE ANYWHERE FROM A QUARTER TO A HALF INCH OF RAIN AS THESE
SYSTEMS MOVE THROUGH THE REGION. IN AREAS WHERE THE FORCING IS
BETTER PRECIPITATION TOTALS WILL LIKELY RANGE FROM A HALF TO ONE
INCH. THE MODELS CONTINUE TO INDICATE THAT THERE WILL BE SOME
ELEVATED CAPES /UP TO 200 J/KG MOVING ACROSS THE AREA FROM LATE
THIS EVENING INTO THE OVERNIGHT. THIS SHOULD BE ENOUGH TO KEEP THE
ISOLATED THUNDERSTORMS IN THE FORECAST. IN ADDITION...THE MODEL
SOUNDINGS ACROSS TAYLOR AND NORTHERN CLARK COUNTIES SHOW THAT
THERE WILL BE AN ELEVATED WARM LAYER /UP 2C/ BETWEEN 900 MB AND
750 MB WITH A COLD LAYER BELOW. THIS WILL BE DEEP ENOUGH TO
REFREEZE ANY SNOW THAT MELTED IN THE WARM LAYER AFTER MIDNIGHT. AS
A RESULT...WENT WITH A MIX OF RAIN...SLEET...AND SNOW FOR THESE
COUNTIES. WITH THE SURFACE TEMPERATURES AND SOILS UNUSUALLY
WARM...NOT EXPECTING ANY ACCUMULATIONS OF SNOW OR SLEET FROM THIS
SYSTEM.
ON FRIDAY...THE MODELS ARE INDICATING THAT THERE WILL BE A
CHANCE OF LIGHT RAIN OR DRIZZLE ACROSS WISCONSIN DURING THE
MORNING. ADDITIONAL RAINFALL AMOUNTS WILL LIKELY ONLY RANGE
FROM A TRACE TO A FEW HUNDREDTHS OF AN INCH. LIKE THE PAST
COUPLE OF DAYS...THE MODELS CONTINUE TO SHOW THAT EAST WINDS OFF
OF THE GREAT LAKES WILL BRING MUCH COOLER TEMPERATURES INTO THE
REGION. TEMPERATURES ACROSS MUCH OF EASTERN WISCONSIN WILL LIKELY
ONLY GET INTO THE 40S. MEANWHILE TEMPERATURES IN SOUTHEAST
MINNESOTA AND NORTHEAST IOWA WILL BE MAINLY IN THE 60S.
ON FRIDAY NIGHT...IT CONTINUES TO LOOK LIKE A SURFACE HIGH
WILL BUILD ACROSS NORTHERN AND EASTERN WISCONSIN. THIS HIGH
WILL RESULT IN LIGHT AND VARIABLE WINDS AND ALLOW THE
TEMPERATURES TO FALL OFF INTO THE MID 30S ACROSS NORTH-CENTRAL
AND CENTRAL WISCONSIN. IF SKIES HAPPEN TO CLEAR OFF MORE THAN
EXPECTED...THESE TEMPERATURES MAY FALL TO AROUND 30. FOR THE
TIME BEING...JUST MENTIONED THE POSSIBILITY OF FROST IN THE
GRIDS TO COVER THIS POTENTIAL.
ON SATURDAY AFTERNOON AND NIGHT...A WARM FRONT WILL BE LOCATED
ACROSS NORTHERN IOWA AND NORTHERN ILLINOIS. THE MODELS THAT
THE 850 MB JET WILL BRING SOME MODEST MOISTURE TRANSPORT INTO
NORTHEAST IOWA AND SOUTHWEST WISCONSIN. THE NAM/WRF IS THE
MOST ROBUST AND THE FASTEST AT GENERATING PRECIPITATION ACROSS
THIS AREA. MEANWHILE THE OTHER MODELS SUGGEST THAT THE BETTER
CHANCES WILL BE ON SATURDAY EVENING. WITH MEAN LAYER CAPES
CLIMBING INTO THE 500 TO 1000 J/KG RANGE...THERE WILL BE THE
POTENTIAL OF SOME THUNDERSTORMS. THE MODELS SHOW 0-6KM SHEAR
IN THE EXCESS OF 40 KNOTS. HOWEVER WITH MUCH OF THE SHEAR LOCATED
BELOW THE INVERSION...THERE IS SOME CONCERN THAT THE MODELS MAY BE
OVERDOING THE SHEAR AVAILABLE FOR THESE THUNDERSTORMS. THIS AREA
IS CURRENTLY UNDER SEE TEXT FOR DAY 3 AND WILL HAVE TO BE WATCHED
OVER THE NEXT TWO DAYS. IF SEVERE WEATHER DID HAPPEN TO OCCUR...
THE MAIN SEVERE WEATHER THREAT WOULD BE LARGE HAIL.
.LONG TERM...SUNDAY THROUGH THURSDAY
346 PM CDT THU MAR 29 2012
FOR SUNDAY...THE MODELS CONTINUE TO STRUGGLE WITH THE LOCATION OF
THE WARM FRONT. SOME OF THE MODELS SUGGEST A FURTHER SOUTHWEST
LOCATION. AS A RESULT...WESTERN WISCONSIN IS NOT AS WARM AS SOME
MODELS INDICATE...THEREFORE...WENT MORE CONSERVATIVE WITH MAXIMUM
TEMPERATURES FOR THIS TIME PERIOD.
FOR THE REMAINDER OF THIS TIME PERIOD...THE MODELS CONTINUE TO
STRUGGLE WITH THE TIMING AND STRENGTH OF SHORT WAVES MOVING THROUGH
THE REGION. THIS MAKES THE TEMPERATURE AND PRECIPITATION FORECAST
RATHER UNCERTAIN. AS A RESULT...STAYED WITH THE ALL BLEND DATA.
&&
.AVIATION...THROUGH 18Z FRIDAY
1242 PM CDT THU MAR 29 2012
MAIN AVIATION FORECAST CONCERNS ARE CLOUDS INCREASING AND CEILINGS
LOWERING INTO THE IFR/MVFR CONDITIONS...AND THE POSSIBILITY OF
THUNDERSTORMS AT BOTH RST AND LSE TAF SITES AFTER 02Z FRIDAY.
LATEST MOSAIC RADAR SHOWING A LINE OF SHOWERS AND THUNDERSTORMS
FROM NORTHWEST MINNESOTA INTO EASTERN SOUTH DAKOTA. LATEST 29.12Z
NAM AND 29.15Z RUC INDICATE LOW PRESSURE OVER THE CENTRAL PLAINS
TO TRACK SOUTH OF THE AREA AND INTO WESTERN ILLINOIS TONIGHT AND
FRIDAY MORNING. BOTH THE NAM/RUC BUFKIT SOUNDINGS SHOW CEILINGS
LOWERING AFTER 02Z FRIDAY AND VISIBILITIES REDUCED...DUE TO ONSET
OF SHOWERS...INTO THE IFR RANGE AT RST AFTER 05Z FRIDAY...WITH
MVFR TO NEAR IFR CONDITIONS EXPECTED AT LSE AFTER 06Z. THE 28.12Z
NAM AND 28.15Z RUC SHOW THE MVFR TO NEAR IFR CONDITIONS TO LINGER
THROUGH 18Z FRIDAY AND ALSO THE POSSIBILITY OF DRIZZLE PER BUFKIT
SOUNDINGS. HAVE CONTINUED THESE CONDITIONS AT BOTH TAF SITES
THROUGH 18Z. THE DETERMINISTIC RUC AND NAM CONTINUE SHOW SOME
INSTABILITY IN ASSOCIATION WITH THE LOW PRESSURE SYSTEM AND HAVE
MENTIONED CB BETWEEN 05-09Z FRIDAY WHEN THE BEST CHANCES OF
THUNDERSTORMS POSSIBLY OCCURRING AT BOTH RST AND LSE TAF SITES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
346 PM CDT THU MAR 29 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...DTJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1243 PM CDT THU MAR 29 2012
.SHORT TERM...TODAY
856 AM CDT THU MAR 29 2012
LATEST 14Z METARS INDICATE TEMPERATURES HAVE CLIMBED INTO THE
MIDDLE 30S TO UPPER 40S. THEREFORE...THE FREEZE WARNING AND FROST
ADVISORY HAS BEEN ALLOWED TO EXPIRE AT 9 AM THIS MORNING.
.LONG TERM...SUNDAY THROUGH WEDNESDAY
351 AM CDT THU MAR 29 2012
29.00Z MODELS IN BETTER AGREEMENT SUNDAY WITH THE AREA TO BE UNDER
STRONG RIDGING ALOFT AND IN THE WARM SECTOR OF THE NEXT LOW/TROUGH
MOVING ACROSS THE NORTHERN PLAINS. STRONG SOUTHERLY LOW LEVEL FLOW
OVER THE AREA SUN WITH 925MB TEMPS CLIMBING INTO THE +20 TO +24C
RANGE. RAISED SUNDAY HIGHS TOWARD THE WARMER MID 70S TO LOWER 80S
GUIDANCE VALUES OVER MUCH OF THE FCST AREA. BEYOND SUNDAY...MODELS
DIFFER...WITH LARGE DIFFERENCES...ON THE EVOLUTION OF THE TROUGHING
MOVING INTO/ACROSS THE CENTRAL CONUS. GFS/ECMWF ARE MORE PROGRESSIVE
SOLUTION WHILE UKMET/GEM SLOWER...MORE CLOSED LOW LINGERING IN THE
CENTRAL CONUS EARLY NEXT WEEK. ECMWF DOES SHOW SOME BETTER RUN-TO-
RUN CONSISTENCY IN THE MON-WED PERIOD AS THE TROUGHING MOVES ACROSS
THE UPPER MIDWEST. A BLEND OF IT AND THE ENSEMBLE MEANS PREFERRED.
SHRA/TSRA CHANCES IN THE 30-40 PERCENT RANGE CENTERED ON MON/MON
NIGHT REASONABLE FOR NOW WITH THE EXPECTED SFC-MID LEVEL TROUGH
PASSAGE. AFTER A WARM SUN/MON...TEMPS COOL IN DEEPER NORTHWEST FLOW
BEHIND THE TROUGH/LOW FOR TUE/WED. DAY 4-7 FCST GRIDS USING A
MODEL/ENSEMBLE CONSENSUS LOOK WELL TRENDED AT THIS TIME.
&&
.AVIATION...THROUGH 18Z FRIDAY
1242 PM CDT THU MAR 29 2012
MAIN AVIATION FORECAST CONCERNS ARE CLOUDS INCREASING AND CEILINGS
LOWERING INTO THE IFR/MVFR CONDITIONS...AND THE POSSIBILITY OF
THUNDERSTORMS AT BOTH RST AND LSE TAF SITES AFTER 02Z FRIDAY.
LATEST MOSAIC RADAR SHOWING A LINE OF SHOWERS AND THUNDERSTORMS
FROM NORTHWEST MINNESOTA INTO EASTERN SOUTH DAKOTA. LATEST 29.12Z
NAM AND 29.15Z RUC INDICATE LOW PRESSURE OVER THE CENTRAL PLAINS
TO TRACK SOUTH OF THE AREA AND INTO WESTERN ILLINOIS TONIGHT AND
FRIDAY MORNING. BOTH THE NAM/RUC BUFKIT SOUNDINGS SHOW CEILINGS
LOWERING AFTER 02Z FRIDAY AND VISIBILITIES REDUCED...DUE TO ONSET
OF SHOWERS...INTO THE IFR RANGE AT RST AFTER 05Z FRIDAY...WITH
MVFR TO NEAR IFR CONDITIONS EXPECTED AT LSE AFTER 06Z. THE 28.12Z
NAM AND 28.15Z RUC SHOW THE MVFR TO NEAR IFR CONDITIONS TO LINGER
THROUGH 18Z FRIDAY AND ALSO THE POSSIBILITY OF DRIZZLE PER BUFKIT
SOUNDINGS. HAVE CONTINUED THESE CONDITIONS AT BOTH TAF SITES
THROUGH 18Z. THE DETERMINISTIC RUC AND NAM CONTINUE SHOW SOME
INSTABILITY IN ASSOCIATION WITH THE LOW PRESSURE SYSTEM AND HAVE
MENTIONED CB BETWEEN 05-09Z FRIDAY WHEN THE BEST CHANCES OF
THUNDERSTORMS POSSIBLY OCCURRING AT BOTH RST AND LSE TAF SITES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
922 AM CDT THU MAR 29 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM....RRS
AVIATION...DTJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1136 PM MDT WED MAR 28 2012
.AVIATION...06Z TAF ISSUANCE...SCATTERED TO BROKEN MID AND HIGH
LEVEL CLOUDINESS WILL MOVE FROM WEST TO EAST ACROSS WYOMING
OVERNIGHT IN ADVANCE OF UPPER LEVEL TROUGH. A SURFACE FRONT
OVER CENTRAL WYOMING WILL MOVE THROUGH SOUTHEAST WYOMING BY
DAYBREAK...AND THE WESTERN PANHANDLE EARLY THURSDAY MORNING.
A BRIEF PERIOD OF MVFR CONDITIONS IN LIGHT RAIN/SNOW SHOWERS WILL
BE POSSIBLE AT RAWLINS. 00Z HRRR AND SREF MODEL GUIDANCE SUGGEST
SOME LOW LEVEL MOISTURE POOLING OVER THE SOUTHERN AND EAST
PANHANDLE...WITH AREAS OF FOG AND LOW CEILINGS DEVELOPING AFTER
08Z. A PERIOD OF IFR TO LIFR CONDITIONS WILL BE POSSIBLE FROM
ALLIANCE TO SIDNEY FROM 08Z TO 12Z. AS WINDS SHIFT TO THE WEST
AND PICK UP...CEILINGS AND FOG SHOULD LIFT. GUSTY NORTHWEST WINDS
WILL THEN OCCUR WITH THE FRONTAL PASSAGE AND LAST THROUGH THURSDAY
AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 941 PM MDT WED MAR 28 2012/
UPDATE...LATEST WATER VAPOR LOOP WAS SHOWING A FAIRLY DECENT
SHORTWAVE MOVING THROUGH EASTERN IDAHO WITH ABOUT 100-110KT JET
STREAK MOVING THROUGH THAT REGION. LATEST IR IMAGERY WAS SHOWING A
NARROW BAND OF CLOUD TOPS COOLING ACROSS NORTHERN UTAH STRETCHING
NORTHEAST INTO SOUTHEAST IDAHO. CURRENT OBSERVATIONS ARE NOT
SHOWING MUCH IN THE WAY OF PRECIP FALLING UNDERNEATH THESE COOLING
TOPS. HOWEVER...THIS MAY NOT LAST LONG AS THE COLUMN CONTINUES TO
SATURATE WHICH IS EVIDENT ON THE BLENDED PRECIPITABLE WATER
IMAGERY. THIS BAND OF PRECIP ALSO APPEARS TO BE ASSOCIATED WITH
SOME DECENT INSTABILITY IN THE 700-600MB LAYER WHICH MAY RESULT IN
SOME POCKETS OF HIGHER AMOUNTS (IE .10 INCH). THE MODELS ARE
PROGGING THIS BAND OF PRECIP TO SHIFT EAST AS THE NIGHT WEARS ON
WHICH MAY RESULT IN SOME LIGHT RAIN/SNOW SHOWERS WITH THE BULK OF
THE SNOW SHOWERS POSSIBLE IN ELEVATIONS ABOVE 7000FT. WE DID
INCREASE POPS ACROSS THE WESTERN COUNTIES OVERNIGHT INTO TOMORROW
MORNING AND ALSO RAISED SNOW AMOUNTS TO AROUND AN INCH IN THE
SNOWY AND SIERRA MADRE RANGES.
FOG IS STILL POSSIBLE IN THE SOUTHEAST PANHANDLE OVERNIGHT AS THE
SOUTHERLY FLOW CONTINUES TO ADVECT IN HIGHER DEW POINTS BEFORE THE
TROF PASSES THROUGH.
COX
PREV DISCUSSION... /ISSUED 557 PM MDT WED MAR 28 2012/
LATEST SURFACE ANALYSIS WAS SHOWING A FAIRLY DISTINCT SURFACE
TROF EXTENDING FROM NEAR GILLETTE TO AREAS BETWEEN CASPER AND
RIVERTON SOUTH TO NEAR ROCK SPRINGS. AHEAD OF THIS BOUNDARY THERE
IS ABOUT 2MB PRESSURE FALLS WITH VERY LIMITED PRESSURE RISES
DIRECTLY BEHIND IT. IN FACT...THE BETTER PRESSURE RISES ARE ACROSS
IDAHO WHERE THERMAL GRADIENT IS A LITTLE BETTER. AT THIS
JUNCTURE...I WOULD EXPECT SOUTH/SOUTHWEST FLOW TO PERSIST THROUGH
MUCH OF THE EVENING. THE BETTER SOUTHERLY FLOW SHOULD BE MAINLY
EAST OF THE LARAMIE RANGE WHILE TO THE WEST SHOULD BE MAINLY
SOUTHWEST. LATER TONIGHT THE TROF WILL PASS THROUGH LARAMIE
SHORTLY AFTER MIDNIGHT .CYS AND BFF NEAR DAYBREAK.
THE TAF SITES IN THE PANHANDLE WILL MAINLY SEE SOUTHERLY FLOW. 50
DEGREE DEWPOINT ARE BEGINNING TO KNOCK ON THE DOOR IN SOUTHWEST
NEBRASKA. I AM A BIT CONCERNED THAT SOME OF THIS LOW LEVEL
MOISTURE MAY BLEED INTO SNY OVERNIGHT AND CAUSE SOME LIFR CEILINGS
TO DEVELOP. AS A RESULT...I WENT AHEAD AND MENTIONED A BRIEF
PERIOD OF LIFR CEILINGS SHORTLY AFTER MIDNIGHT...BUT THESE
CEILINGS SHOULD ERODE FAIRLY QUICKLY BEFORE DAYBREAK AS THE TROF
PUSHES THROUGH. AFTER THE TROF PASSES THROUGH...NORTHWEST FLOW
WILL PERSIST ACROSS MOST OF THE TAF SITES TOMORROW AT SPEEDS OF 15
TO 25 KT.
COX
PREV DISCUSSION... /ISSUED 251 PM MDT WED MAR 28 2012/
SHORT TERM...TONIGHT THROUGH SATURDAY...TEMPERATURES TO REMAIN
WELL ABOVE NORMAL AND MINIMAL CHANCES FOR PRECIPITATION THROUGH
SATURDAY. THE ONE CHANCE FOR PRECIPITATION WILL BE TONIGHT WITH
THE PASSAGE OF AN UPPER TROUGH. WATER VAPOR SHOWING AN UPPER LOW
CURRENTLY OVER WESTERN WASHINGTON LIFTING NORTHEAST INTO SOUTHWEST
CANADA. SOUTHWEST FLOW AHEAD OF THE LOW IS STREAMING MOISTURE OUT
OF THE PACIFIC INTO THE SOUTHWEST CONUS. MOST MOISTURE WILL BE
RUNG OUT BEFORE REACHING THE FORECAST AREA. MAINLY EXPECTING
INCREASED CLOUD COVER TONIGHT BUT SOME RAIN AND SNOW IS A GOOD
POSSIBILITY INTO THE FAR WESTERN FORECAST AREA INCLUDING THE SNOWY
AND SIERRA RANGES. PRECIPITATION AMOUNTS IN THESE AREAS...SHOULD
IT OCCUR...WILL BE MINIMAL WITH LESS THAN A TENTH OF AN INCH OF
WATER EXPECTED. HIGHER ELEVATIONS MAINLY ABOVE 10 KFT WILL SEE
TEMPERATURES DROP ENOUGH LATE TONIGHT FOR SNOW. ANY ACCUMULATIONS
SHOULD BE ABOVE 10 KFT WITH AN INCH OR LESS OF ACCUMULATION.
CHANCES FOR MEASURABLE PRECIPITATION VERY LOW EAST OF THE LARAMIE
RANGE TONIGHT. PROGGED SOUNDINGS DRY BELOW ABOUT 10 KFT AGL SUCH
THAT PRECIPITATION ALOFT WILL HAVE A TOUGH TIME REACHING THE
GROUND. EXPECTING TO SEE PLENTY OF RETURNS ON RADAR LATE TONIGHT
BUT SHOULD MOSTLY BE VIRGA.
COULD SEE SOME FOG FORM OVER THE WESTERN NEBRASKA PANHANDLE FOR A
TIME TONIGHT. RELATIVELY JUICY DEW POINTS WILL CONTINUE TO ADVECT
INTO THE AREA THIS EVENING WITH DEW POINTS WELL INTO THE 40S
AROUND SIDNEY AND ALLIANCE. WINDS WILL BECOME LIGHT AND VARIABLE
POSSIBLE ALLOW FOR RADIATION FOG TO FORM. FORTUNATELY WINDS WILL
SHIFT TO THE WEST AS THE UPPER TROUGH APPROACHES. THIS WILL
SIGNIFICANTLY MITIGATE THE POTENTIAL FOR WIDESPREAD OR DENSE FOG
TONIGHT.
SLIGHTLY COOLER THURSDAY AS COOLER AIR WILL MOVE INTO THE AREA
BEHIND THE TROUGH TONIGHT. EVEN WITH THE COOLER AIR IN PLACE HIGH
TEMPERATURES WILL SEE BE AROUND 15 DEGREES ABOVE NORMAL THURSDAY.
RIDGING TOMORROW NIGHT INTO FRIDAY WILL ALLOW FOR HIGH
TEMPERATURES TO WARM BACK TO 20 TO 25 DEGREES ABOVE NORMAL. NOT
EXPECTING RECORD HIGH TEMPERATURES FRIDAY BUT RECORD HIGH ARE
A GOOD BET FOR SATURDAY AS VERY WARM AIR PUSHES NORTH AHEAD OF
THE NEXT UPPER LEVEL SYSTEM.
LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...ANOTHER MILD NIGHT
IS EXPECTED SATURDAY NIGHT BEFORE A PACIFIC COLD FRONT MOVES FROM
WEST TO EAST ACROSS THE AREA SUNDAY MORNING. SHOULD SEE COOLER
TEMPS FROM SATURDAY...ALTHOUGH VALUES STILL LOOK TO REMAIN ABOVE
NORMAL. THE OVERALL UPPER LEVEL TROUGH ASSOCIATED WITH THIS FRONT
LOOKS TO BE SLIGHTLY SLOWER AND DIGGING FURTHER SOUTH WITH THE
12Z MODELS...AND MID LEVEL MOISTURE LOOKS SUFFICIENT TO BRING A
CHANCE FOR RAIN AND SNOW ACROSS THE AREA SUNDAY AND SUNDAY NIGHT.
BUMPED UP POPS SOME FOR THIS SCENARIO AS THE MODELS ARE FAIRLY
CONSISTENT WITH EACH OTHER WITH THIS TREND. NORTHWEST WINDS BEHIND
THE FRONT WILL BE MODERATE TO STRONG AT TIMES ON SUNDAY AS
HIGH PRESSURE BUILDING IN FROM THE WEST TIGHTENS THE LLVL PRESSURE
GRADIENT...ESPECIALLY IN THE WIND CORRIDOR REGION. THE FRONT WILL
PUSH OFF TO THE EAST SUNDAY NIGHT AND MONDAY WITH THE GRADIENT
REMAINING RELATIVELY STRONG THROUGH THIS TIME. THE MAIN TROUGH
WILL MOVE OVERHEAD THEN AS WELL...SO THE COMBINATION OF SUBSIDENCE
ALOFT AND THE GRADIENT WILL KEEP WINDS ELEVATED ON MONDAY WITH
LESS WIND FOR TUESDAY. MONDAY WILL CONTINUE TO BE
COOLER...RELATIVELY SPEAKING...BUT RIDGING WILL RETURN TO THE
ROCKIES FOR TUESDAY WITH A RISE IN TEMPS ONCE AGAIN. DRY AND
BREEZY CONDITIONS WILL PERSIST THROUGH WEDNESDAY WITH A BETTER
CHANCE FOR CRITICAL FIRE WEATHER CONDITIONS TO BE MET DURING THIS
TIME.
&&
FIRE WEATHER...
RED FLAG WARNING TO EXPIRE THIS EVENING AS WINDS WILL DIE
OFF AND HUMIDITY RECOVERS. COOLER TEMPERATURES YIELDING HIGHER
HUMIDITY THURSDAY SHOULD PRECLUDE RED FLAG CONDITIONS ALTHOUGH
MARGINAL CONDITIONS ARE EXPECTED FOR A FEW HOURS TOWARD CHEYENNE
IN THE AFTERNOON...BUT CERTAINLY NOTHING WIDESPREAD. TROUGH
PASSING ACROSS THE AREA TONIGHT MAY PRODUCE SOME LIGHT RAIN
SHOWERS TOWARD THE RAWLINS AFTER MIDNIGHT WITH SOME SNOW
POSSIBLE IN THE HIGHER ELEVATIONS OF THE SNOWY AND SIERRA RANGES.
ANY ACCUMULATIONS SHOULD BE AN INCH OR LESS. TEMPERATURES FRIDAY
WILL BE SIMILAR TO THAT OF TODAY AS WILL WIND SPEEDS BUT HUMIDITY
VALUES MAY NOT DROP AS FAR. AT THIS TIME IT APPEARS MARGINAL FOR
RED FLAG FRIDAY DEPENDING ON SURFACE DEW POINTS...HOWEVER...
WIDESPREAD RED FLAG CONDITIONS ARE EXPECTED SATURDAY AS NEAR
RECORD TEMPERATURES AND GUSTY WEST TO SOUTHWEST WINDS DEVELOP.
ACTUALLY IT WILL BE VERY WINDY SATURDAY. DRY THURSDAY THROUGH
SATURDAY WITH VIRTUALLY NO CHANCE FOR PRECIPITATION.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...TJT
LONG TERM/AVIATION...JAMSKI
AREA FORECAST DISCUSSION
NWS LINCOLN IL
256 AM CDT SAT MAR 31 2012
.DISCUSSION...
ISSUED 255 AM CDT SAT MAR 31 2012
THE COLD FRONT THAT PASSED THROUGH LAST EVENING WAS NEAR THE OHIO
RIVER EARLY THIS MORNING. NORTHEAST WINDS ARE BRINGING A STRATUS
DECK SOUTHEASTWARD...REACHING TAYLORVILLE AND MATTOON AT 3 AM.
SIGNIFICANT PUSH OF COOLER AIR HAS DROPPED TEMPERATURES INTO THE
40S UNDERNEATH THE CLOUDS.
INITIAL FORECAST CONCERNS INVOLVE TEMPERATURES TODAY WITH THE
EFFECTS OF ANY LINGERING CLOUD COVER...AS WELL AS MUCH WARMER
CONDITIONS FOR SUNDAY AND MONDAY. TIMING AND COVERAGE OF MIDWEEK
SHOWERS ARE ALSO AN ISSUE.
SHORT TERM...TODAY THROUGH MONDAY...
LATEST RUC AND HRRR MODELS SUGGESTING THAT THE CLOUD DECK SHOULD
TRACK A LITTLE FURTHER SOUTH IN THE NEXT FEW HOURS...BEFORE
BEGINNING TO ERODE. WITH THIS THINKING...HAVE TRENDED THE SKY
GRIDS TO BE MOSTLY SUNNY BY MIDDAY...EXCEPT PERHAPS OVER THE FAR
NORTH. SHOULD GET TEMPERATURES INTO THE 70S ACROSS THE
SOUTHWEST...WITH COOLER 60S NORTHEAST. A SLOWER THAN EXPECTED
CLOUD BREAKUP WOULD RESULT IN TEMPERATURES IN THAT AREA CLOSER TO
THE COOLER MET GUIDANCE...BUT HAVE GONE CLOSER TO THE WARMER MAV
MOS AT THE MOMENT.
LATEST MODEL SUITE SHOWING MCS DEVELOPMENT ACROSS EASTERN IOWA
OVERNIGHT...AS A FRONTAL BOUNDARY ESTABLISHES ITSELF FROM NORTHERN
IOWA TO LOWER MICHIGAN. LATEST ECMWF MODEL IS THE FURTHEST SOUTH
WITH THE TRACK...REACHING POTENTIALLY AS FAR SOUTH AS SPRINGFIELD
AND DECATUR BY SUNRISE. THE REMAINING MODELS HAVE THE MCS SKIMMING
THE NORTH/NORTHEAST BORDER. HAVE MAINTAINED THE RAIN CHANCES OVER
THE NORTHERN HALF OF THE CWA...PRIMARILY BETWEEN MIDNIGHT AND
SUNRISE...AND SCALED THEM BACK ACROSS THE SOUTH.
UPPER RIDGE PROGGED BY THE MODELS TO AMPLIFY OVER THE CENTRAL
UNITED STATES THIS WEEKEND...SHIFTING TO THE MISSISSIPPI VALLEY BY
EARLY MONDAY MORNING. PRETTY GOOD SLUG OF WARM AIR WILL SPREAD
OVER THE STATE...WITH 850 MB TEMPERATURES RISING TO NEAR 20C ON
MONDAY. HAVE CONTINUED WITH THE 80S FOR HIGHS FOR SUNDAY...BUT
WILL NEED TO MONITOR THE CIRRUS BLOWOFF FROM THE MCS WHICH MAY
HELP KEEP TEMPS FROM RISING QUITE AS MUCH. HOWEVER...HAVE BOOSTED
HIGHS ON MONDAY BY A FEW DEGREES FROM EARLIER FORECASTS...AS THAT
WARMER AIR AT 850 MB MIXES TOWARD THE SURFACE. MAY SEE SOME RECORD
HIGHS AGAIN...AS CURRENT VALUES ARE IN THE MID TO UPPER 80S.
MAV/MEX MOS GUIDANCE SUGGESTING SOME 90 DEGREE READINGS ARE
POSSIBLE ACROSS THE SOUTHWEST CWA.
LONG TERM...TUESDAY THROUGH FRIDAY...
UPPER LEVEL TROUGHING ACROSS THE DESERT SOUTHWEST LATE THIS
WEEKEND WILL CUT OFF INTO A CLOSED LOW...WHICH IS PROGGED TO DRIFT
INTO THE CENTRAL PLAINS BY MIDWEEK. EXTENDED RANGE MODELS STARTING
TO TREND NORTHWARD WITH THIS TRACK...WITH THE GFS THE FARTHEST
NORTH INTO SOUTHERN IOWA. CURRENTLY PREFER THE MORE SOUTHERN
SOLUTION SOUTH OF THE OHIO VALLEY. AN EXTENDED PERIOD OF RAIN IS
LIKELY OVER PORTIONS OF THE MID-MISSISSIPPI VALLEY...BUT DRY
EASTERLY WINDS ASSOCIATED WITH A HIGH OVER THE GREAT LAKES WILL
CAUSE SOME EROSION OF THE PRECIP ON THE NORTHEAST FLANK. THE
LATEST ECMWF SURGES THE PRECIPITATION MUCH FURTHER NORTH THAN ITS
EARLIER RUN AND COVERS MOST OF THE CWA...WHILE THE CANADIAN MODEL
IS MORE LIMITED TO THE SOUTHEAST. HAVE INTRODUCED SLIGHT CHANCE
POPS FOR NOW ACROSS THE SOUTHEAST CWA WEDNESDAY NIGHT AND
THURSDAY...AND THESE MAY NEED TO BE BOOSTED IN FUTURE PACKAGES AS
MODEL AGREEMENT BECOMES TIGHTER.
GEELHART
&&
.AVIATION...
ISSUED 1115 PM CDT FRI MAR 30 2012
MVFR CIGS CONTINUE TO SETTLE SLOWLY SOUTH ACRS THE FORECAST AREA
LATE THIS EVENING. 1500-2000 FOOT CIGS HAVE SPREAD AS FAR SOUTH
AS A DNV-BMI-PIA LINE AND EXPECT THE SOUTHWARD DRIFT TO CONTINUE
THRU THE EARLY MORNING HOURS. CONFIDENCE ON JUST HOW FAR SOUTH THE
CLOUDS WILL GO IS RATHER LOW AS MODELS HAVING A DIFFICULT TIME
PICKING UP THE MOISTURE AT THIS LAYER. LOW LEVEL WIND FORECASTS
SUGGEST THE CLOUDS WILL CONTINUE TO SINK SOUTH OVERNIGHT BEFORE
THE BOUNDARY LAYER WINDS GO MORE EAST TO SOUTHEAST TOMORROW...
WHICH WOULD START TO SHIFT THE CLOUDS BACK TO THE WNW. WILL TIME
THE CLOUDS INTO THE SITES TONIGHT THAT HAVE NOT ALREADY SEEN THEM
MOVE IN...AND THEN KEEP THEM IN THRU AT LEAST MID MORNING SATURDAY
BEFORE A DECREASE IN CLOUD COVER IS SEEN. LOOKS AS IF DECATUR AND
SPRINGFIELD WILL BE THE LAST TO SEE THE CLOUDS MOVE IN OVERNIGHT
WITH TIMING IN THE 0630-0730Z RANGE.
SFC WINDS WILL CONTINUE TO GRADUALLY VEER MORE INTO A NORTHEAST
TO EAST DIRECTION OVERNIGHT...AND THEN VEER MORE INTO THE SE AS
THE DAY WEARS ON SATURDAY. SPEEDS TONIGHT AND SATURDAY WILL RANGE
FROM 8 TO 15 KTS.
SMITH
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
324 AM CDT SAT MAR 31 2012
...UPDATED LONG TERM DISCUSSION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 300 AM CDT SAT MAR 31 2012
.SYNOPSIS...
ISSUED AT 300 AM CDT SAT MAR 31 2012
THE 00Z 300 HPA SYNOPTIC MAP SHOWS A STRONG 140 KT JET TRAVERSING ACROSS
THE PACIFIC NORTHWEST. ACROSS THE PLAINS, 45 TO 65 KT NORTHWESTERLY
FLOW WAS OBSERVED IN THE WAKE OF A DEPARTING TROUGH AXIS LOCATED ACROSS
THE EASTERN PLAINS/MIDWEST. THE 500 HPA MAP SHOWED THAT VERY COLD AIR
OF -38 DEG C WAS OBSERVED ACROSS VANCOUVER ISLAND. IN THE LOWER LEVELS
(700 AND 850 HPA), A DRY AIRMASS WAS OVER THE PLAINS, PARTICULARLY ACROSS
THE NORTHERN PLAINS. SURFACE ANALYSIS FROM HPC SHOWED A LOW PRESSURE
SYSTEM WITH ASSOCIATED COLD AND WARM FRONTS MOVING ACROSS THE CANADIAN
PRAIRIES. HIGH PRESSURE WAS OVER THE CENTRAL AND SOUTHERN PLAINS. DEWPOINTS
CONTINUED TO BE IN THE MODERATE LEVELS (FOR END OF MARCH) WITH LOWER
TO MID 50S DEG F DEWPOINTS ACROSS SW AND SC KANSAS.
THIS MORNING:
THE MAIN FORECAST CONCERN FOR THIS MORNING IN TERMS OF SENSIBLE WEATHER
IS IF FOG WILL DEVELOP OR NOT. THE 01Z AND 02Z HRRR RUNS WERE VERY AGGRESSIVE
IN DEVELOPING DENSE FOG ACROSS THE SW/W KANSAS. THE 04Z HRRR RUN HAS
BACKED OFF ON THIS WITH A SMALLER AREA OF DENSE FOG MAINLY ACROSS HAMILTON
COUNTY. WHAT IS INTERESTING IS THAT EVEN THOUGH THE MODEL DEVELOPS THE
FOG, THE MODELS ALSO HAS DOWNSLOPE SSW AS THE SFC. THIS IS NOT CONDUCIVE
FOR DENSE FOG FORMATION ACROSS MY COUNTY WARNING AREA. VSREF ALSO SHOWED
SOME HIGHER PROBABILITIES FOR LOWER VIS ACROSS THE AREA. OTHER MODEL
GUIDANCE IS LESS SUGGESTIVE FOR FOG FORMATION. DESPITE THIS, OBSERVATIONS
ACROSS OKLAHOMA SHOW SOME PATCHY FOG DEVELOP THIS MORNING SO I HAVE
DECIDED TO MEET THE MODELS IN BETWEEN AND INSERT PATCHY FOG ACROSS MY
WESTERN COUNTIES. DEWPOINTS ARE CURRENTLY IN THE 50S DEG F WITH UPSLOPE
SE/S WINDS SO THE POTENTIAL CANNOT BE COMPLETELY DISMISSED ATTM.
TODAY:
500 HPA FLOW WILL BECOME MORE MORE WESTERLY THROUGH TODAY, WHICH WILL
STRENGTHEN LEE TROUGHING. AS A RESULT, A WARM AIR ADVECTION PATTERN
WILL BE IN PLACE TODAY WITH TEMPERATURES WARMING WELL ABOVE NORMAL.
MID 80S DEG F ARE EXPECTED FOR HIGHS TODAY, WHICH IS ABOUT 20 DEGREES
ABOVE NORMAL. THIS WARM MARCH WE HAVE BEEN EXPERIENCING WILL END ON
A VERY WARM NOTE FOR THE LAST DAY IN THE MONTH. TODAY WILL BE PRECIPITATION
FREE AS A FAIRLY FLAT UPPER LEVEL RIDGE PREVAILS ACROSS KANSAS. I HAVE
GONE WITH SLIGHTLY COOLER TEMPERATURES TODAY (MID 80S DEG F VERSUS UPPER
80S DEG F) AS RECENT VERIFICATION PER BOI VERIFY SHOWS THAT MODELS ARE
SUFFERING A BIT OF WARM BIAS. SOUTHERLY WINDS OF 15 TO 20 KT ARE EXPECTED
THIS AFTERNOON AS MIXING INCREASES TO ABOUT 750 HPA AND SOME STRONGER
WINDS MIX DOWN.
TONIGHT:
THE LEE SURFACE TROUGH AXIS WILL MOVE SLIGHTLY EASTWARD TONIGHT AND
FRAGMENT TOWARDS SUNDAY MORNING. THIS WILL KEEP SOUTHERLY WINDS IN THE
FORECAST OVERNIGHT. DEWPOINTS IN THE 30S DEG F WEST TO 50S DEG F EAST
WILL KEEP OVERNIGHT LOWS ON THE MILD SIDE, PARTICULARLY ACROSS SOUTH
CENTRAL KANSAS. HAVE AROUND 60 DEG F TOWARDS KP28 (MEDICINE LODGE, KS)
AND COOLER MID 40S NEAR K3K3 (SYRACUSE, KS).
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 322 AM CDT SAT MAR 31 2012
MODELS REMAINING VERY CONSISTENT WITH PREVIOUS RUNS AND KEEP
SUNDAY SUNNY AND WARM . 850MB 00Z MONDAY TEMPERATURES STILL
SUPPORT HIGHS AROUND 90 DEGREES FOR MUCH OF SOUTHWEST KANSAS.
THESE HIGHS FOR THE FIRST OF APRIL COULD EASILY SET NEW RECORD
HIGHS IN A FEW LOCATIONS. A FEW RECORDS FOR APRIL FIRST ARE....88
DEGREES AT DODGE CITY, 87 AT GARDEN CITY AND 93 DEGREES AT
MEDICINE LODGE.
IN ADDITION TO THIS UNSEASONABLY WARM TEMPERATURES...LOW DEW
POINTS WILL BE SPREADING INTO PORTIONS OF WESTERN KANSAS BEHIND A
DRYLINE. THIS WILL RESULT IN AFTERNOON RELATIVE HUMIDITIES
BOTTOMING OUT IN THE 10 TO 15 PERCENT RANGE IN SEVERAL LOCATIONS.
GIVEN THESE LOW RELATIVE HUMIDITIES ALONG WITH GUSTY SOUTHWEST
WINDS DEVELOPING DURING THE AFTERNOON HAVE DECIDED TO CONTINUE THE
FIRE WEATHER WATCH ACROSS MUCH OF WESTERN KANSAS.
FOR EARLY NEXT WEEK...OUR NEXT UPPER LEVEL STORM SYSTEM IS STILL
FORECAST BY THE GFS, ECMWF, AND CANADIAN TO CROSS THE FOUR CORNERS
REGION SUNDAY NIGHT. BY MONDAY THIS SYSTEM WILL BEGIN TO DEEPEN
ACROSS NEW MEXICO WHERE IT WILL MOVE VERY LITTLE THROUGH TUESDAY.
AHEAD OF THIS SYSTEM A SOUTHEAST FLOW WILL DRAW MORE HUMID AIR
NORTHWARD TOWARDS SOUTHWEST KANSAS ON MONDAY. IN ADDITION 850MB
WARM AIR ADVECTION AND 850-700 FRONTOGENESIS WILL BE ON THE
INCREASE LATE IN THE DAY ALONG AND JUST BEHIND A COLD FRONT WHICH
WILL BE CROSSING SOUTHERN KANSAS/NORTHERN OKLAHOMA. GIVEN THIS
IMPROVING LIFT/MOISTURE AHEAD OF THE DEEPENING NEW MEXICO LOW WILL
BEGIN INCREASING CLOUD COVER AND PRECIPITATION CHANCES EARLY
MONDAY NIGHT. WINDS BEHIND THIS COLD FRONT MAY ALSO BE AN ISSUE
LATE MONDAY AND EARLY MONDAY NIGHT AS A TIGHT SURFACE PRESSURE
GRADIENT IS EXPECTED TO DEVELOP ACROSS PORTIONS OF SOUTHWEST
KANSAS IN RESPONSE TO AN AREA OF LOW PRESSURE DEEPENING ALONG THIS
FRONTAL BOUNDARY NEAR THE OKLAHOMA PANHANDLE.
TUESDAY THROUGH EARLY WEDNESDAY STILL APPEARS SOMEWHAT UNCLEAR
GIVEN THE DISAGREEMENT ON TRACK OF THIS UPPER LOW AS IT MOVES EAST
INTO THE PANHANDLE OF TEXAS. SINCE MODELS DO NOT HANDLE THESE
SYSTEM WELL, ESPECIALLY BEYOND 72 HOURS WILL FOLLOW THE GENERAL
TREND OF THE ALLBLEND THROUGH MID WEEK. HAVE THEREFORE INCREASED
PRECIPITATION CHANCES ACROSS SOUTHWEST KANSAS AND GIVEN THE CLOUDS
AND PRECIPITATION EXPECTED HAVE ALSO LOWERED TEMPERATURES TUESDAY
AFTERNOON.
BY LATE WEDNESDAY THIS UPPER LOW MOVE EAST ACROSS THE PLAINS. AS
THIS SYSTEM MOVES EAST OF WESTERN KANSAS THE SKIES WILL CLEAR AS
AN UPPER LEVEL SHORTWAVE RIDGE STARTS TO BUILD INTO THE ROCKIES
FROM THE WEST. AS THE WESTERLY DOWNSLOPE FLOW IMPROVES LATE WEEK
TEMPERATURES WILL REBOUND OUT OF 60S AND BACK INTO THE
70S...POSSIBLY A FEW 80S BY LATE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1200 AM CDT SAT MAR 31 2012
VFR CIGS ARE EXPECTED THROUGH THE TAF PERIOD. THE 01Z HRRR WAS
SUGGESTING THAT FOG WILL DEVELOP ACROSS FAR WEST KANSAS TOMORROW MORNING
WEST OF THE TERMINALS. WILL HAVE TO WATCH THIS TO SEE IF THE TREND/OBSERVATIONS
SHOW THIS THROUGH THE OVERNIGHT PERIOD AND IF THE FOG WILL EXTEND EAST.
OTHERWISE, WILL LEAVE FG OUT OF THE TAFS FOR NOW AS THIS IS THE ONLY
MODEL SUGGESTING THE POSSIBILITY OF LIFR/IFR CIGS. OTHERWISE, SOUTHERLY
WINDS WILL BECOME BREEZY (15-20 KT) THIS AFTERNOON IN ASSOCIATION WITH
AN EASTWARD EXTENSION OF A SURFACE TROUGH AXIS ACROSS WESTERN KS.
&&
.FIRE WEATHER...
ISSUED AT 300 AM CDT SAT MAR 31 2012
MARGINAL FIRE WEATHER CONDITIONS ARE EXPECTED SATURDAY AFTERNOON, AS
THE RELATIVE HUMIDITIES WILL NOT MEET RH CRITERIA. HAVE ADDRESSED THIS
CONCERN IN FWF. NEXT CONCERN IS CRITICAL FIRE WEATHER CONDITIONS EXPECTED
SUNDAY AFTERNOON. TEMPERATURES WILL BE VERY WARM AND WINDS WILL BE STRONGER
AS LEE CYCLOGENESIS STRENGTHENS ACROSS EASTERN COLORADO AND THE RELATED
PRESSURE GRADIENT INCREASES ACROSS THE REGION. THE FUEL STATUS PAGE
SHOWS THAT STEVENS AND MORTON COUNTY ARE A NO GO AS FUELS ARE NOT AT
THE APPROPRIATE LEVELS (NOTHING TO BURN?). THIS MAY HAVE TO BE ADDRESSED
BEFORE THE RFW IS ISSUED. OTHERWISE, AFTER COLLABORATION, IT WAS DECIDED
TO CONTINUE THE FIRE WEATHER WATCH FOR FAR WESTERN KANSAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 85 56 90 53 / 0 0 0 10
GCK 86 52 90 50 / 0 0 0 10
EHA 85 51 90 50 / 0 0 0 10
LBL 86 53 92 49 / 0 0 0 10
HYS 86 58 88 53 / 0 0 0 10
P28 84 60 88 58 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR KSZ061-062-074-075-084-085.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....BURGERT
AVIATION...SUGDEN
FIRE WEATHER...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
300 AM CDT SAT MAR 31 2012
...UPDATED SYNOPSIS/SHORT TERM/FIRE WEATHER DISCUSSIONS...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 300 AM CDT SAT MAR 31 2012
.SYNOPSIS...
ISSUED AT 300 AM CDT SAT MAR 31 2012
THE 00Z 300 HPA SYNOPTIC MAP SHOWS A STRONG 140 KT JET TRAVERSING ACROSS
THE PACIFIC NORTHWEST. ACROSS THE PLAINS, 45 TO 65 KT NORTHWESTERLY
FLOW WAS OBSERVED IN THE WAKE OF A DEPARTING TROUGH AXIS LOCATED ACROSS
THE EASTERN PLAINS/MIDWEST. THE 500 HPA MAP SHOWED THAT VERY COLD AIR
OF -38 DEG C WAS OBSERVED ACROSS VANCOUVER ISLAND. IN THE LOWER LEVELS
(700 AND 850 HPA), A DRY AIRMASS WAS OVER THE PLAINS, PARTICULARLY ACROSS
THE NORTHERN PLAINS. SURFACE ANALYSIS FROM HPC SHOWED A LOW PRESSURE
SYSTEM WITH ASSOCIATED COLD AND WARM FRONTS MOVING ACROSS THE CANADIAN
PRAIRIES. HIGH PRESSURE WAS OVER THE CENTRAL AND SOUTHERN PLAINS. DEWPOINTS
CONTINUED TO BE IN THE MODERATE LEVELS (FOR END OF MARCH) WITH LOWER
TO MID 50S DEG F DEWPOINTS ACROSS SW AND SC KANSAS.
THIS MORNING:
THE MAIN FORECAST CONCERN FOR THIS MORNING IN TERMS OF SENSIBLE WEATHER
IS IF FOG WILL DEVELOP OR NOT. THE 01Z AND 02Z HRRR RUNS WERE VERY AGGRESSIVE
IN DEVELOPING DENSE FOG ACROSS THE SW/W KANSAS. THE 04Z HRRR RUN HAS
BACKED OFF ON THIS WITH A SMALLER AREA OF DENSE FOG MAINLY ACROSS HAMILTON
COUNTY. WHAT IS INTERESTING IS THAT EVEN THOUGH THE MODEL DEVELOPS THE
FOG, THE MODELS ALSO HAS DOWNSLOPE SSW AS THE SFC. THIS IS NOT CONDUCIVE
FOR DENSE FOG FORMATION ACROSS MY COUNTY WARNING AREA. VSREF ALSO SHOWED
SOME HIGHER PROBABILITIES FOR LOWER VIS ACROSS THE AREA. OTHER MODEL
GUIDANCE IS LESS SUGGESTIVE FOR FOG FORMATION. DESPITE THIS, OBSERVATIONS
ACROSS OKLAHOMA SHOW SOME PATCHY FOG DEVELOP THIS MORNING SO I HAVE
DECIDED TO MEET THE MODELS IN BETWEEN AND INSERT PATCHY FOG ACROSS MY
WESTERN COUNTIES. DEWPOINTS ARE CURRENTLY IN THE 50S DEG F WITH UPSLOPE
SE/S WINDS SO THE POTENTIAL CANNOT BE COMPLETELY DISMISSED ATTM.
TODAY:
500 HPA FLOW WILL BECOME MORE MORE WESTERLY THROUGH TODAY, WHICH WILL
STRENGTHEN LEE TROUGHING. AS A RESULT, A WARM AIR ADVECTION PATTERN
WILL BE IN PLACE TODAY WITH TEMPERATURES WARMING WELL ABOVE NORMAL.
MID 80S DEG F ARE EXPECTED FOR HIGHS TODAY, WHICH IS ABOUT 20 DEGREES
ABOVE NORMAL. THIS WARM MARCH WE HAVE BEEN EXPERIENCING WILL END ON
A VERY WARM NOTE FOR THE LAST DAY IN THE MONTH. TODAY WILL BE PRECIPITATION
FREE AS A FAIRLY FLAT UPPER LEVEL RIDGE PREVAILS ACROSS KANSAS. I HAVE
GONE WITH SLIGHTLY COOLER TEMPERATURES TODAY (MID 80S DEG F VERSUS UPPER
80S DEG F) AS RECENT VERIFICATION PER BOI VERIFY SHOWS THAT MODELS ARE
SUFFERING A BIT OF WARM BIAS. SOUTHERLY WINDS OF 15 TO 20 KT ARE EXPECTED
THIS AFTERNOON AS MIXING INCREASES TO ABOUT 750 HPA AND SOME STRONGER
WINDS MIX DOWN.
TONIGHT:
THE LEE SURFACE TROUGH AXIS WILL MOVE SLIGHTLY EASTWARD TONIGHT AND
FRAGMENT TOWARDS SUNDAY MORNING. THIS WILL KEEP SOUTHERLY WINDS IN THE
FORECAST OVERNIGHT. DEWPOINTS IN THE 30S DEG F WEST TO 50S DEG F EAST
WILL KEEP OVERNIGHT LOWS ON THE MILD SIDE, PARTICULARLY ACROSS SOUTH
CENTRAL KANSAS. HAVE AROUND 60 DEG F TOWARDS KP28 (MEDICINE LODGE, KS)
AND COOLER MID 40S NEAR K3K3 (SYRACUSE, KS).
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 216 PM CDT FRI MAR 30 2012
MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL RIDGE OF HIGH PRESSURE
TRANSITIONING EAST ACROSS THE CENTRAL PLAINS SUNDAY AND INTO THE
MISSISSIPPI RIVER VALLEY MONDAY RESULTING IN FAIRLY DRY CONDITIONS
ACROSS WESTERN KANSAS THROUGH SUNDAY NIGHT. MEANWHILE, AN UPPER
LEVEL TROUGH OF LOW PRESSURE IS EXPECTED TO PUSH EAST ACROSS THE
INTERMOUNTAIN WEST SUNDAY AND INTO THE WESTERN HIGH PLAINS EARLY
MONDAY BRINGING THE POSSIBILITY FOR PRECIP TO THE CENTRAL PLAINS
EARLY NEXT WEEK. ALTHOUGH STILL DIFFERING IN SOME DETAILS, THE GEM,
GFS, AND ECMWF ARE IN BETTER AGREEMENT SHOWING THE WAVE CLOSING OFF
AS IT SLIDES EAST-SOUTHEAST INTO THE SOUTH PLAINS OF OKLAHOMA, NORTH
TEXAS, AND PORTIONS OF SOUTHERN KANSAS. THE DETAILS AT ISSUE INCLUDE
THE TIMING OF AN ATTENDANT COLD FRONT EXPECTED TO PUSH THROUGH
WESTERN KANSAS SOMETIME MONDAY WITH A DRYLINE PASSAGE PRECLUDING THE
FRONT REDUCING THE AVAILABILITY OF LOW LEVEL MOISTURE AHEAD OF THE
UPPER LEVEL SYSTEM INITIALLY. THE ECMWF HAS FALLEN MORE IN LINE WITH
THE GFS SOLUTION BUT DIGS THE CLOSED OFF LOW A LITTLE FURTHER SOUTH
INTO TEXAS. THE GEM SOLUTION IS MUCH MORE IN LINE WITH THE GFS IN
HOW THIS MAY PLAY OUT SETTING UP THE CLOSED LOW SLIGHTLY MORE NORTH
BUT STILL JUST TO OUR SOUTH BY EARLY TUESDAY WITH H7 FRONTOGENETIC
BANDING INITIALLY DEVELOPING ACROSS PORTIONS OF SOUTHEASTERN
COLORADO AND SOUTHWESTERN KANSAS SOMETIME LATE MONDAY INTO EARLY
TUESDAY. ADDITIONALLY, TO SOME DEGREE ALL MODELS SHOW AN INCREASE IN
LOW TO MID LEVEL MOISTURE ACROSS WESTERN KANSAS LATE MONDAY INTO
TUESDAY AS THE UPPER LOW BEGINS TO DRAW MOISTURE NORTHWARD. THIS
COULD BRING A REASONABLE CHANCE FOR RAIN ACROSS PARTS OF KANSAS
DURING THIS GENERAL TIME FRAME. RIGHT NOW, 20 TO 30 POPS SEEMS
REASONABLE LATE MONDAY INTO TUESDAY CONSIDERING THE UNCERTAINTY OF
ALL THE FACTORS CONCERNED.
TEMPERATURES WILL BE WELL ABOVE NORMAL SUNDAY AS THE UPPER LEVEL
RIDGE MOVES EAST ACROSS THE CENTRAL PLAINS. A SURFACE LOW IS
EXPECTED TO DEVELOP ACROSS NORTHEASTERN COLORADO HELPING TO
MAINTAIN MORE OF A SOUTH TO SOUTHWEST LOW LEVEL FLOW ACROSS
WESTERN KANSAS. THIS WILL ENHANCE WARM AIR ADVECTION INTO THE
AREA WITH H85 TEMPERATURES RANGING FROM THE LOWER 20S(C) ACROSS
CENTRAL KANSAS TO JUST ABOVE 25C ALONG THE COLORADO BORDER. NAM AND
GFS MODEL SOUNDINGS ALSO SHOW STEEP LAPSE RATES DEVELOPING BY EARLY
TO MID AFTERNOON AS MAX HEATING IS APPROACHED. EXPECT HIGHS WELL UP
INTO THE 80S(F) WITH LOWER 90S(F) POSSIBLE IN SOME LOCATIONS SUNDAY
AFTERNOON. A SIGNIFICANT COOLING TREND IS EXPECTED TO BEGIN MONDAY
AS A COLD FRONT IS PROJECTED TO PUSH THROUGH WESTERN KANSAS SOMETIME
DURING THE DAY. THE TIMING OF THE FRONTAL PASSAGE IS STILL VERY MUCH
UNCERTAIN BUT CLOSER TO SEASONAL TEMPERATURES CAN BE EXPECTED MONDAY
WITH EVEN COOLER TEMPERATURES LIKELY TUESDAY AS COLDER AIR SURGES
SOUTH INTO WESTERN KANSAS. A GRADUAL WARMING TREND IS EXPECTED BY
THE END OF THE PERIOD AS UPPER LEVEL RIDGING IS PROJECTED TO
DEVELOP ACROSS THE WESTERN HIGH PLAINS BY MID TO LATE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1200 AM CDT SAT MAR 31 2012
VFR CIGS ARE EXPECTED THROUGH THE TAF PERIOD. THE 01Z HRRR WAS
SUGGESTING THAT FOG WILL DEVELOP ACROSS FAR WEST KANSAS TOMORROW MORNING
WEST OF THE TERMINALS. WILL HAVE TO WATCH THIS TO SEE IF THE TREND/OBSERVATIONS
SHOW THIS THROUGH THE OVERNIGHT PERIOD AND IF THE FOG WILL EXTEND EAST.
OTHERWISE, WILL LEAVE FG OUT OF THE TAFS FOR NOW AS THIS IS THE ONLY
MODEL SUGGESTING THE POSSIBILITY OF LIFR/IFR CIGS. OTHERWISE, SOUTHERLY
WINDS WILL BECOME BREEZY (15-20 KT) THIS AFTERNOON IN ASSOCIATION WITH
AN EASTWARD EXTENSION OF A SURFACE TROUGH AXIS ACROSS WESTERN KS.
&&
.FIRE WEATHER...
ISSUED AT 300 AM CDT SAT MAR 31 2012
MARGINAL FIRE WEATHER CONDITIONS ARE EXPECTED SATURDAY AFTERNOON, AS
THE RELATIVE HUMIDITIES WILL NOT MEET RH CRITERIA. HAVE ADDRESSED THIS
CONCERN IN FWF. NEXT CONCERN IS CRITICAL FIRE WEATHER CONDITIONS EXPECTED
SUNDAY AFTERNOON. TEMPERATURES WILL BE VERY WARM AND WINDS WILL BE STRONGER
AS LEE CYCLOGENESIS STRENGTHENS ACROSS EASTERN COLORADO AND THE RELATED
PRESSURE GRADIENT INCREASES ACROSS THE REGION. THE FUEL STATUS PAGE
SHOWS THAT STEVENS AND MORTON COUNTY ARE A NO GO AS FUELS ARE NOT AT
THE APPROPRIATE LEVELS (NOTHING TO BURN?). THIS MAY HAVE TO BE ADDRESSED
BEFORE THE RFW IS ISSUED. OTHERWISE, AFTER COLLABORATION, IT WAS DECIDED
TO CONTINUE THE FIRE WEATHER WATCH FOR FAR WESTERN KANSAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 85 56 90 53 / 0 0 0 10
GCK 86 52 90 50 / 0 0 0 10
EHA 85 51 90 50 / 0 0 0 10
LBL 86 53 92 49 / 0 0 0 10
HYS 86 58 88 53 / 0 0 0 10
P28 84 60 88 58 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR KSZ061-062-074-075-084-085.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....JJOHNSON
AVIATION...SUGDEN
FIRE WEATHER...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1200 AM CDT SAT MAR 31 2012
...UPDATE TO AVIATION FOR 06Z TAFS...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 212 PM CDT FRI MAR 30 2012
THE 12Z UPPER AIR ANALYSIS SHOWED A VERY WEAK SHORTWAVE TROUGH OVER
THE FRONT RANGE OF COLORADO EXTENDING SOUTHWARD INTO NEW MEXICO. AT
THE SURFACE...WEAK HIGH PRESSURE HAD SETTLED INTO WESTERN KANSAS
WHILE A WEAK LOW PRESSURE HAD MOVED SOUTH INTO NORTHWEST TEXAS.
MODEST LOW LEVEL MOISTURE WAS IN PLACE ACROSS SOUTH CENTRAL KANSAS
WHERE DEWPOINTS WERE IN THE MID 50S. DEWPOINTS WERE IN THE LOW 60S
ACROSS SOUTHERN OKLAHOMA INTO TEXAS.
THE SHORTWAVE HAS BEEN PROGRESSING STEADILY OVER THE CENTRAL HIGH
PLAINS THIS MORNING AND WILL BE MOVING INTO EASTERN KANSAS AND
OKLAHOMA BY LATE THIS AFTERNOON. MODEL SOUNDINGS ARE SHOWING SOME
MODERATE INSTABILITY OVER SOUTH CENTRAL KANSAS BUT ARE ALSO SHOWING
SOME WEAK BUT FAIRLY DEEP CAPPING IN THE 800-700 MB LAYER. WITH THE
WAVE MOVING PAST THE AREA BY PEAK HEATING, CONVECTIVE INHIBITION IN
THE CAPPING LAYER PLUS THE LACK OF ANY SURFACE CONVERGENCE...DO NOT
THINK WE WILL SEE ANY THUNDERSTORMS DEVELOPING ALONG THE OKLAHOMA
BORDER AND HAVE REMOVED THEM FROM THE FORECAST FOR THIS EVENING.
THE MODELS SHOW SURFACE DEWPOINTS INCREASING SOMEWHAT TONIGHT. HAVE
BUMPED UP OVERNIGHT LOWS A FEW DEGREES TO ACCOUNT FOR THIS. THERE
COULD BE SOME MIST DEVELOPING OVER PARTS OF SOUTHWEST KANSAS
OVERNIGHT BUT MODEL SOUNDINGS SHOW THE LOW LEVEL MOISTURE TO BE
PRETTY SHALLOW SO AM NOT EXPECTING ANY SIGNIFICANT FOG DEVELOPMENT.
ON SATURDAY AN UPPER LEVEL RIDGE WILL BE MOVING OVER THE CENTRAL
HIGH PLAINS. WE SHOULD SEE FAIRLY DEEP MIXING WHICH WILL ALLOW
TEMPERATURES TO CLIMB WELL UP INTO THE 80S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 216 PM CDT FRI MAR 30 2012
MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL RIDGE OF HIGH PRESSURE
TRANSITIONING EAST ACROSS THE CENTRAL PLAINS SUNDAY AND INTO THE
MISSISSIPPI RIVER VALLEY MONDAY RESULTING IN FAIRLY DRY CONDITIONS
ACROSS WESTERN KANSAS THROUGH SUNDAY NIGHT. MEANWHILE, AN UPPER
LEVEL TROUGH OF LOW PRESSURE IS EXPECTED TO PUSH EAST ACROSS THE
INTERMOUNTAIN WEST SUNDAY AND INTO THE WESTERN HIGH PLAINS EARLY
MONDAY BRINGING THE POSSIBILITY FOR PRECIP TO THE CENTRAL PLAINS
EARLY NEXT WEEK. ALTHOUGH STILL DIFFERING IN SOME DETAILS, THE GEM,
GFS, AND ECMWF ARE IN BETTER AGREEMENT SHOWING THE WAVE CLOSING OFF
AS IT SLIDES EAST-SOUTHEAST INTO THE SOUTH PLAINS OF OKLAHOMA, NORTH
TEXAS, AND PORTIONS OF SOUTHERN KANSAS. THE DETAILS AT ISSUE INCLUDE
THE TIMING OF AN ATTENDANT COLD FRONT EXPECTED TO PUSH THROUGH
WESTERN KANSAS SOMETIME MONDAY WITH A DRYLINE PASSAGE PRECLUDING THE
FRONT REDUCING THE AVAILABILITY OF LOW LEVEL MOISTURE AHEAD OF THE
UPPER LEVEL SYSTEM INITIALLY. THE ECMWF HAS FALLEN MORE IN LINE WITH
THE GFS SOLUTION BUT DIGS THE CLOSED OFF LOW A LITTLE FURTHER SOUTH
INTO TEXAS. THE GEM SOLUTION IS MUCH MORE IN LINE WITH THE GFS IN
HOW THIS MAY PLAY OUT SETTING UP THE CLOSED LOW SLIGHTLY MORE NORTH
BUT STILL JUST TO OUR SOUTH BY EARLY TUESDAY WITH H7 FRONTOGENETIC
BANDING INITIALLY DEVELOPING ACROSS PORTIONS OF SOUTHEASTERN
COLORADO AND SOUTHWESTERN KANSAS SOMETIME LATE MONDAY INTO EARLY
TUESDAY. ADDITIONALLY, TO SOME DEGREE ALL MODELS SHOW AN INCREASE IN
LOW TO MID LEVEL MOISTURE ACROSS WESTERN KANSAS LATE MONDAY INTO
TUESDAY AS THE UPPER LOW BEGINS TO DRAW MOISTURE NORTHWARD. THIS
COULD BRING A REASONABLE CHANCE FOR RAIN ACROSS PARTS OF KANSAS
DURING THIS GENERAL TIME FRAME. RIGHT NOW, 20 TO 30 POPS SEEMS
REASONABLE LATE MONDAY INTO TUESDAY CONSIDERING THE UNCERTAINTY OF
ALL THE FACTORS CONCERNED.
TEMPERATURES WILL BE WELL ABOVE NORMAL SUNDAY AS THE UPPER LEVEL
RIDGE MOVES EAST ACROSS THE CENTRAL PLAINS. A SURFACE LOW IS
EXPECTED TO DEVELOP ACROSS NORTHEASTERN COLORADO HELPING TO
MAINTAIN MORE OF A SOUTH TO SOUTHWEST LOW LEVEL FLOW ACROSS
WESTERN KANSAS. THIS WILL ENHANCE WARM AIR ADVECTION INTO THE
AREA WITH H85 TEMPERATURES RANGING FROM THE LOWER 20S(C) ACROSS
CENTRAL KANSAS TO JUST ABOVE 25C ALONG THE COLORADO BORDER. NAM AND
GFS MODEL SOUNDINGS ALSO SHOW STEEP LAPSE RATES DEVELOPING BY EARLY
TO MID AFTERNOON AS MAX HEATING IS APPROACHED. EXPECT HIGHS WELL UP
INTO THE 80S(F) WITH LOWER 90S(F) POSSIBLE IN SOME LOCATIONS SUNDAY
AFTERNOON. A SIGNIFICANT COOLING TREND IS EXPECTED TO BEGIN MONDAY
AS A COLD FRONT IS PROJECTED TO PUSH THROUGH WESTERN KANSAS SOMETIME
DURING THE DAY. THE TIMING OF THE FRONTAL PASSAGE IS STILL VERY MUCH
UNCERTAIN BUT CLOSER TO SEASONAL TEMPERATURES CAN BE EXPECTED MONDAY
WITH EVEN COOLER TEMPERATURES LIKELY TUESDAY AS COLDER AIR SURGES
SOUTH INTO WESTERN KANSAS. A GRADUAL WARMING TREND IS EXPECTED BY
THE END OF THE PERIOD AS UPPER LEVEL RIDGING IS PROJECTED TO
DEVELOP ACROSS THE WESTERN HIGH PLAINS BY MID TO LATE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1200 AM CDT SAT MAR 31 2012
VFR CIGS ARE EXPECTED THROUGH THE TAF PERIOD. THE 01Z HRRR WAS
SUGGESTING THAT FOG WILL DEVELOP ACROSS FAR WEST KANSAS TOMORROW MORNING
WEST OF THE TERMINALS. WILL HAVE TO WATCH THIS TO SEE IF THE TREND/OBSERVATIONS
SHOW THIS THROUGH THE OVERNIGHT PERIOD AND IF THE FOG WILL EXTEND EAST.
OTHERWISE, WILL LEAVE FG OUT OF THE TAFS FOR NOW AS THIS IS THE ONLY
MODEL SUGGESTING THE POSSIBILITY OF LIFR/IFR CIGS. OTHERWISE, SOUTHERLY
WINDS WILL BECOME BREEZY (15-20 KT) THIS AFTERNOON IN ASSOCIATION WITH
AN EASTWARD EXTENSION OF A SURFACE TROUGH AXIS ACROSS WESTERN KS.
&&
.FIRE WEATHER...
ISSUED AT 216 PM CDT FRI MAR 30 2012
CRITICAL FIRE WEATHER CONDITIONS ARE POSSIBLE SUNDAY AS AN UPPER
LEVEL RIDGE OF HIGH PRESSURE DRIFTS EAST ACROSS THE CENTRAL PLAINS.
AS MENTIONED EARLIER, A SURFACE LOW IS EXPECTED TO DEVELOP ACROSS
NORTHEASTERN COLORADO DURING THE DAY HELPING TO INFLUENCE A SOUTH TO
SOUTHWESTERLY LOW LEVEL FLOW ACROSS WESTERN KANSAS. NAM AND GFS
MODEL SOUNDINGS INDICATE A CAPPING INVERSION DISSOLVING BY EARLY TO
MID AFTERNOON ALLOWING STRONGER WINDS ALOFT TO MIX DOWN TO THE
SURFACE. ADDITIONALLY, A DRYLINE ATTENDANT TO THE SURFACE LOW IS
FORECAST TO EDGE EASTWARD ACROSS EXTREME WESTERN KANSAS RESULTING
IN VERY LOW RELATIVE HUMIDITY LEVELS. AS A RESULT, A FIRE WEATHER
WATCH WILL BE ISSUED FOR EXTREME SOUTHWESTERN KANSAS FOR SUNDAY
AFTERNOON INTO EARLY SUNDAY EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 52 85 57 90 / 0 0 0 0
GCK 49 86 51 90 / 0 0 0 0
EHA 48 86 47 90 / 0 0 0 0
LBL 51 87 52 92 / 0 0 0 0
HYS 52 87 58 88 / 0 0 0 0
P28 58 84 61 88 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR KSZ061-062-074-075-084-085.
&&
$$
SHORT TERM...GERARD
LONG TERM....JJOHNSON
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS WICHITA KS
1148 PM CDT FRI MAR 30 2012
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
THE FOG POTENTIAL IS INCREASING FOR SE KS WHERE NEARLY CALM WINDS &
NARROWING TEMP/DWPT DEPRESSIONS RESIDE. SHORT-TERM SOUNDINGS (MORE SO
THE NAMBUFR) ARE INDICATING SUCH INCREASED POTENTIAL AS WELL. AS SUCH
ANTICIPATE VSBYS TO VARY FROM 1 1/2SM-3SM BR OVER KCNU FROM 10Z-13Z.
THE BR SHOULD DISSIPATE QUICKLY ~13Z AS INSOLATION INCREASES & S WINDS
SLOWLY ASSERT THEMSELVES. THE BR/FOG POTENTIAL SHOULD BE MUCH LWR OVER
CNTRL KS (ESPECIALLY WHEN COMPARED TO EARLY THIS MORNING!) WHERE WINDS
TAKE ON MORE SWLY COMPONENT & SLOWLY INCREASE. AS SUCH ALL 5 TERMINALS
TO REALIZE VFR STATUS THE REST OF 06Z TAF CYCLE.
&&
PREV DISCUSSION... /ISSUED 302 PM CDT FRI MAR 30 2012/
DISCUSSION...
FORECAST CHALLENGES...ISOLATED STORM CHANCES/PATCHY FOG POTENTIAL
TONIGHT...THEN PRECIP CHANCES/COOLING TREND EARLY NEXT WEEK.
TONIGHT-SUNDAY
DRIER LOW LEVELS IN WAKE OF SURFACE TROF AND NOCTURNAL
CONVECTION/OUTFLOW THAT EXITED SOUTHERN KANSAS LAST NIGHT HAS
STABILIZED AIRMASS ACROSS THE AREA. HOWEVER THE RUC AND TO A
LESSER EXTENT THE HRRR SUGGEST ISOLATED CONVECTION MAY DEVELOP
ACROSS THE FLINT HILLS OR SOUTHEAST KANSAS BY EARLY THIS
EVENING...WHERE MODEST INSTABILITY WILL RESIDE IN PRESENCE OF
WEAKENING INHIBITION. SO WILL KEEP ISOLATED TSRA MENTION FOR
AREAS SOUTHEAST OF GREATER WICHITA. IF CONVECTION DEVELOPS IT MAY
PERSIST INTO A PORTION OF THE OVERNIGHT HOURS...AIDED BY A WEAK
UPPER SHORTWAVE MOVING ACROSS THE LOWER MISSOURI VALLEY. LOCAL
PROCEDURES OFF THE SHORT TERM MODELS ARE SUGGESTIVE OF PATCHY FOG
AROUND DAWN ACROSS PORTIONS OF SOUTH CENTRAL/SOUTHEAST KANSAS.
UNSEASONABLY WARM AND MAINLY DRY WEATHER STILL LOOKS IN ORDER
FOR THIS WEEKEND AS A LARGE AMPLITUDE UPPER RIDGE DEVELOPS ACROSS
THE PLAINS. ANOTHER MORE SUBTLE UPPER SHORTWAVE WILL RIPPLE THRU
THE DEVELOPING RIDGE TO OUR NORTH AND EAST ON SATURDAY AFTERNOON
AND EVENING. THIS WILL KEEP MID LEVEL TEMPERATURES RELATIVELY COOL
PORTENDING TO WEAK CAPPING ACROSS EASTERN KANSAS...WHERE MODEST
DIURNAL INSTABILITY WILL EXIST TOWARD PEAK HEATING. WHILE AN
ISOLATED STORM CANNOT BE RULED OUT...WILL KEEP THE FORECAST DRY
FOR NOW. SUNDAY LOOKS TO BE THE WARMEST DAY...DARE WE SUGGEST
ALMOST HOT...ACROSS THE FORECAST AREA. MAXS SHOULD APPROACH
RECORDS IN SOME AREAS NEAR 90F...WITH GUSTY SOUTH WINDS.
MONDAY
A SIGNIFICANT UPPER TROF WILL MOVE ACROSS THE ROCKIES ON SUNDAY
NIGHT AND INTO THE HIGH PLAINS ON MONDAY. WILL CONTINUE TO CARRY
MODEST CHANCE POPS AHEAD OF THIS FEATURE AND ASSOCIATED SURFACE
FRONT...THOUGH SOMEWHAT SLOWER TIMING SUGGESTED A SLIGHT UP-TWEAK
TO MAXS WERE NEEDED AND A BIT SLOWER ONSET TO POPS.
TUESDAY-FRIDAY
THE MEDIUM RANGE MODELS ARE STILL GRAPPLING WITH HANDLING THE
EVENTUAL UPPER FLOW STREAM SEPARATION AND MOVEMENT OF THE CLOSED
LOW WHICH BECOMES CUT-OFF FROM THE STRONGER WESTERLIES. THIS LOW
WILL IMPACT KANSAS WEATHER AND PRECIP CHANCES THROUGH THE EARLY
AND MID-WEEK PERIODS...AND FOR NOW HAVE CONTINUED TO LEAN TOWARD
THE HPC GUIDANCE AND MORE PROGRESSIVE GFS.
DARMOFAL
FIRE WEATHER...
DESPITE UNSEASONBALY WARM TEMPERATURES AND INCREASING WINDS OVER
THE WEEKEND...THE GRASSLAND FIRE DANGER RISK IS EXPECTED TO BE
ONLY SLIGHTLY ELEVATED DUE TO THE EARLY SPRING GREEN-UP.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 58 84 61 87 / 0 10 10 0
HUTCHINSON 56 85 61 88 / 0 10 10 0
NEWTON 58 84 61 87 / 0 10 10 0
ELDORADO 59 84 61 87 / 0 10 10 0
WINFIELD-KWLD 59 84 62 87 / 10 10 10 0
RUSSELL 55 87 59 89 / 10 10 10 0
GREAT BEND 55 86 59 88 / 0 10 10 0
SALINA 57 87 61 89 / 10 10 10 0
MCPHERSON 56 85 61 88 / 0 10 10 0
COFFEYVILLE 59 85 62 88 / 20 10 10 0
CHANUTE 59 84 62 87 / 10 10 10 10
IOLA 59 84 62 87 / 10 10 10 10
PARSONS-KPPF 59 84 62 87 / 10 10 10 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1252 AM EDT SAT MAR 31 2012
.Forecast Update...
Issued at 1250 AM EDT Mar 31 2012
The storms have weakened quite a bit across the area with just a
couple of stronger storms remaining across the western portion of
the forecast area. These should weaken over the next hour or two as
well. Rain chances will continue to diminish from northwest to
southeast overnight. The ongoing forecast is in good shape, so have
made only some minor tweaks to POPs and temps.
Issued at 1010 PM EDT Mar 30 2012
Strong to marginally severe storms with hail were across southern
Indiana as of 2Z. Several reports of pea to dime size hail have
been received with one report of quarter size hail in Austin, IN
which has been the strongest storm in our area so far. Expect
strong to marginally severe storms to continue through around 1AM
EDT before diminishing to garden variety t-storms as the line
continues to sink south into Kentucky and weaken. Only made some
minor tweaks to POPs, dewpts, and temps based on current trends this
evening. Temperatures should hold in the 50s for lows tonight.
After it gets done raining, we may see a period of only partly
cloudy or even clear skies. With plentiful moisture at the sfc,
this may allow for some light fog to form. However, don`t expect
any widespread fog due to the mixey nature of the atmosphere so will
leave fog out of the forecast as of now. Also, any clearing would
be brief as upstream obs as well as soundings indicate a good
stratus layer will build into the area before sunrise and stick
around through the morning hours.
Update issued at 840 PM EDT Mar 30 2012
A line of showers/t-storms ahead of/along a sfc cold front was
making steady progress southeast into our area this evening. These
storms have decreased in intensity somewhat and thus a severe
t-storm watch was not issued. Latest model trends indicated that it
will continue to sink south throughout the evening hours and weaken
as it does so. Still think portions of southern Indiana and
northern KY may see some strong storms with small hail and 40 mph
winds, but any severe threat should be diminishing this evening.
Updated the grids to reflect the latest timing of this line of
showers/storms through the forecast area tonight. Also, tweaked
cloud cover overnight to better match the line of storms, some brief
clearing just behind the front, and then low stratus that is
anticipated just before sunrise through early afternoon.
.Short Term (This Afternoon through Saturday Night)...
Issued at 405 PM EDT Mar 30 2012
Afternoon satellite imagery and observations reveal that the warm
front has moved well north of our forecast area. South of this warm
front, the atmosphere continues to destabilize with time. With
current temperatures in the upper 70s to the lower 80s and dewpoints
in the upper 50s to the lower 60s is resulting in mixed layer CAPE
values in the 1250-1750 J/Kg range. Surface lifted indices based
on RUC proximity soundings are running around -4 to -6 degrees
Celsius. Atmosphere remains generally uncapped across the
southeastern/eastern sections of the forecast area. However some
weak capping/CINH still exists out in areas west of I-65.
Sufficient mixing over the next few hours will likely mix that cap
out.
For the rest of the afternoon, we expect partly to mostly sunny
skies with isolated showers and thunderstorms being possible across
portions of the area. The greatest concentration of convection will
generally be east of I-65 where we have a local maxima in the
dewpoint field. Temperatures will remain in the upper 70s and lower
80s through the early evening before dropping into the upper 70s
toward sunset.
As for tonight, the latest high resolution models agree that
convection will continue to develop along a southward moving cold
front which is currently located across central IL, IN, and OH.
This line of convection will likely move eastward as it will be
embedded in the faster mid-level low aloft. However, the line will
slowly sag southward with time. The consensus of the latest models
have trended slower as they adjust to the initial conditions that
are being ingested into the model. Therefore, the slower solution
would keep the bulk of this thunderstorm activity concentrated north
of the Ohio River early this evening. Current thinking is that the
line will likely sag southward to near the Ohio River by 10-11 PM
EDT. As this line head south, it will be encountering a slowly
stabilizing airmass due to the loss of heating and nocturnal PBL
stabilization.
Despite the weaker instability, this line of storms should remain
largely intact as it approaches the Ohio River later this evening.
The main threats still appear to be damaging winds and large hail.
The tornado threat appears to be rather low across our area as
overall bulk shear values decrease the further south you go of the
Ohio River. As the line passes south of the Ohio River, expect the
line to weaken and gradually dissipate as it sinks further south
into KY. For this reason, we will keep highest PoP chances tonight
across southern Indiana and the northern parts of KY and have lesser
chances across southern KY. Overnight lows will cool into the
mid-upper 50s.
Surface frontal boundary is expected to push south of the state
early Saturday with high pressure building into the region. Partly
to mostly sunny skies are expected with highs topping out in the
upper 60s in the Bluegrass region and lower 70s in the central.
Warmest temperatures will be across the south/southwest with
mid-upper 70s. Overnight lows Saturday night will be in the upper
30s-lower 40s in the northeast with mid-upper 40s elsewhere.
.Long Term (Sunday through Friday)...
Updated at 330 PM EDT Mar 30 2012
Ohio Valley will be positioned in northwest mid level flow between
ridging over the south central CONUS and shortwave moving from the
eastern Great Lakes to New England on Sunday. Surface low associated
with northeast shortwave will drag a cold front south toward the
Ohio River by Sunday afternoon. At this point, will continue to keep
forecast dry however may have to eventually add low chance pops
across northern CWA for afternoon showers and storms. Looking for
highs in the low 80s on Sunday as skies stay mostly sunny to partly
cloudy.
Ridge axis slides east to the middle Mississippi River Valley Sunday
night with frontal boundary mentioned above sliding southwest over
the CWA from a backdoor entrance. Front then looks to stall as it
becomes parallel to the mid level flow. Will also continue to keep
this period dry as models do not show enough deep moisture to
warrant pops at this time. Could see a nice gradient in low
temperatures on Sunday night dependent on how much progress front
makes. Will go with low 60s west to upper 50s east.
Closed upper low will make its way to the southern plains on Monday
with surface low developing over the middle Mississippi River
Valley. The resultant tightening pressure gradient will create
steady southwesterly flow and likely lift stalled frontal boundary
back northeast as a warm front. Will include slight chance for a
shower or thunderstorm as this occurs. This will be the warmest day
of the period with low to mid 80s.
Will likely see a lull in activity sometime Monday evening before
more widespread precipitation moves over the area through midweek.
That being said, will leave chance pops in the east for departing
warm front induced showers and storms and uncertainty in timing.
Lows around 60 can be expected.
Confidence in forecast decreases from Tuesday on as models continue
to have trouble with timing on closed upper low meandering from the
southern Plains to the Tennessee Valley or the Gulf Coast states.
Adding to the uncertainty, models disagree on northern stream energy
and its associated surface features dragging a cold front through.
ECMWF is more aggressive with front, dragging it through the region
by Tuesday night, with closed upper low slower and further south.
Meanwhile, GFS/GEM are faster with the upper low which combines the
ample Gulf moisture with the front sagging south from northern
stream system. This scenarios could result from the differing model
solutions. 1.) The ECMWF solution would result in a quick-hitting
shower and storm episode from Tuesday afternoon through Wednesday
morning. 2.) The GFS/GEM solution would bring a prolonged
precipitation event from Tuesday afternoon through at least Thursday
evening as upper low would be further north and slower to move
through. Will lean toward the first solution at this point with best
chances for showers and storms Tuesday afternoon through Wednesday
morning. Thereafter, will keep forecast dry until models converge
on a solution.
Looking for a cool down from midweek with either solution as we will
either be in a post frontal cooler airmass or underneath the
influence of an upper low. Highs in the mid 60s each day with lows
in the mid 40s.
&&
.Aviation (06Z TAF Issuance)...
Updated at 1245 AM EDT Mar 31 2012
The strong storms have weakened quite a bit over the last hour with
just a few clusters of thunderstorms remaining. The rest of the
activity is mainly showers. LEX may see a lightning strike or two
over the next hour, but should be just SHRA by 06Z. The strongest
storm in the area is in south central KY, but it has the chance to
weaken and may stay north of BWG. Therefore, will continue to carry
only VCTS there.
Behind the line of showers and storms ceilings will remain VFR for a
couple of hours. The models do indicate a stratus layer will then
build down. Ceilings are expected to drop to around 1500 ft. and
remain there through mid day. These clouds should scatter out by mid
day with skies clearing in the afternoon. Winds will be generally
light and out of the north to NNW.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........AMS/EER
Short Term.......MJ
Long Term........BJS
Aviation.........EER
AREA FORECAST DISCUSSION
NWS DULUTH MN
331 AM CDT SAT MAR 31 2012
.SHORT TERM...
TODAY THROUGH SUNDAY AFTERNOON...
MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND THE PATCHY FOG
THROUGHOUT THE NORTHLAND WITH DENSE FOG ALONG THE NORTH SHORE AND
AROUND THE TWIN PORTS THIS MORNING...ALONG WITH RAIN SHOWERS MOVING
IN FROM THE NW TODAY...WITH PATCHY FREEZING DRIZZLE POSSIBLE IN THE
TIP OF THE ARROWHEAD BEFORE TEMPERATURES WARM LATE THIS MORNING.
UPPER LEVEL FLOW WILL REMAIN QUASI-ZONAL ACROSS MUCH OF THE CONUS
TODAY...BUT BECOME AMPLIFIED ON SUNDAY AS AN UPPER TROUGH DIGS
INTO THE WRN U.S. A WEAK 500MB S/W AND ASSOCIATED SFC TROUGH OVER
THE WRN DAKOTAS/SRN SASKATCHEWAN/MANITOBA REGION WILL TRACK TO THE
EAST THIS MORNING INTO WRN ONTARIO/NRN MN. RAIN SHOWERS WILL
ACCOMPANY THIS SYSTEM...MAINLY ACROSS THE NRN COUNTIES OF THE
FORECAST AREA. A FEW SHOWERS AND STORMS ARE ONGOING THIS MORNING
AROUND WINNIPEG...ALONG THE NRN EDGE OF A WARM/MOIST/UNSTABLE AIR
MASS BEING ADVECTED IN FROM THE SOUTH AND CO-LOCATED WITH A
NARROW BAND OF LOW LEVEL F-GEN. THIS PRECIP WILL TRY TO MOVE INTO
NE MN THIS MORNING...BUT WILL ENCOUNTER A MORE STABLE AIR MASS AND
DIMINISH IN INTENSITY THROUGH MID MORNING. THE OTHER CONCERN WITH
THIS PRECIP BAND WILL BE THE POTENTIAL FOR FREEZING DRIZZLE INTO
MAINLY LAKE AND COOK COUNTIES BEFORE 10AM. AS THE SURGE OF WARM
AIR ALOFT MOVES EWD OVER THE NEAR FREEZING SFC LAYER IN NE MN...THE
CHC FOR FREEZING PRECIP INCREASES. RUC SOUNDINGS AT ELY PRODUCE A
SATURATED THERMAL PROFILE NEAR FREEZING UP THROUGH 3000 FT...WITH
A VERY DRY LAYER ALOFT. SFC WINDS WILL EVENTUALLY VEER TO THE S/SW
AND USHER IN WARMER AIR FROM THE SOUTH BY LATE MORNING
TODAY...WHICH WILL ALLOW ANY PRECIP TO BECOME ALL LIQUID. LIQUID
PRECIP AMTS WILL RANGE FROM A TRACE UP TO A COUPLE TENTHS OF AN
INCH.
THE OTHER CONCERN IN THE SHORT TERM IS THE DENSE FOG AROUND THE
PERIPHERY OF LAKE SUPERIOR THIS MORNING. THE COMBINATION OF A
MOISTURE SFC LAYER...CONTINUOUS INFLUX OF COOL MOIST AIR FROM THE
EAST...AND A STRONG INVERSION AT THE TOP OF THE BOUNDARY LAYER ARE
ALL AIDING IN THE FORMATION AND PERSISTENCE OF FOG AROUND THE
NORTHLAND. WILL LIKELY SEE THE FOG CONTINUE TODAY AS LONG AS THE
WINDS REMAIN FROM THE EAST OFF THE LAKE. THE APPROACHING SFC
TROUGH SHOULD WIN OUT AND ALLOW WINDS TO VEER TO THE S/SW...WHICH
WILL HELP MIX DOWN SOME DRIER AIR ALOFT AND ERODE THE FOG LAYER BY
LATE MORNING. USUALLY TAKES LONGER THAN EXPECTED...SO MAY NEED TO
EXTEND DENSE FOG ADVISORY LONGER THAN 10AM. HOWEVER...FOR NOW WILL
KEEP WITH 10AM AS THE ENDING TIME.
THE DURATION OF THE EAST WINDS AND CLOUD LAYER WILL ALSO MITIGATE
HOW WARM TEMPERATURES GET TODAY. WITH CLOUD COVER EXPECTED THROUGH
A GOOD PORTION OF THE DAY...DECIDED TO DROP MAX TEMPS
TODAY...MAINLY IN NW WI. KEPT WITH 60S FOR INLAND LOCATIONS OF NE
MN...AND 40S AND 50S AROUND THE LAKE. TEMPS COOL INTO THE 30S AND
40S TONIGHT...AND WARM BACK INTO THE 60S AND LOWER 70S INLAND ON
SUNDAY...WITH 50S AROUND THE LAKE AS EAST WINDS RETURN. RIDGE OF
HIGH PRESSURE BUILDS IN ACROSS THE NRN PLAINS SUNDAY AS THE NEXT
SYSTEM PREPARES TO MOVE IN FROM THE SW SUNDAY NIGHT.
.LONG TERM...
SUNDAY NIGHT THROUGH FRIDAY...
MODEL DIFFERENCES WITH THE MAGNITUDE OF THE FLATTENING/MOVING OF
THE UPPER RIDGE AND THE APPROACHING CLOSED UPPER LOW MOVING
THROUGH CANADA SUNDAY NIGHT. THIS ALSO PLAYS A ROLE IN THE AMOUNT
OF INSTABILITY FOR THUNDERSTORM DEVELOPMENT. USED A BLEND OF
QPF/POPS WITH THE MAJORITY OF THE THUNDERSTORMS HOLDING OFF UNTIL
AFTER 06Z MONDAY. THIS IS WHEN THETAE ADVECTION IS GREATEST. MODEL
DIFFERENCES CONTINUE ON MONDAY AS THE GFS IS QUICK TO MOVE A FRONT
THROUGH THE FA WHILE THE ECMWF/GEM/UKMET ARE THE SLOWEST. HAVE
SIDED WITH THE SLOWER APPROACH WHICH KEEPS THE INSTABILITY AXIS
NEARBY AND THE MENTION OF THUNDERSTORMS NEEDED. CONTINUED WITH THE
SLOWER MODELS MONDAY NIGHT AND LINGERED THE POPS. AN UPPER LEVEL
TROF MOVES THROUGH THE FA TUESDAY PUSHING THE PCPN E ALLOWING SFC
RIDGING TO BUILD IN. THE SFC HIGH BECOMES ANCHORED OVER THE
EASTERN GREAT LAKES TUESDAY NIGHT THROUGH FRIDAY KEEPING THE AREA
IN AN EASTERLY FLOW AND NO PCPN WITH THE DRY AIR FROM THE HIGH
LOCKED INTO THE FA.
&&
.AVIATION...06Z TAFS...
SKIES HAD CLEARED OVER KBRD...BUT MVFR CEILINGS HAVE ALREADY MOVED
BACK IN. IFR OR LOW MVFR CONDITIONS WILL PERSIST TONIGHT...WITH SOME
MIXED PRECIPITATION ACROSS THE FAR NORTH. DENSE FOG CAN BE
EXPECTED AROUND LAKE SUPERIOR. LATEST MODEL RUNS SUGGEST THE LOW
CEILINGS WILL BE SLOWER TO CLEAR ON SATURDAY...AND WE DELAYED THE
TIMING BY 1 TO 3 HOURS IN THE 06Z TAFS.
A SHORTWAVE AND TROUGH WILL ALSO BRING A CHANCE FOR SHOWERS
THROUGH SATURDAY...WITH THE BEST CHANCE ACROSS THE FAR NORTHEAST.
&&
.POINT TEMPS/POPS...
DLH 57 38 56 40 / 20 10 10 40
INL 60 33 60 40 / 30 10 10 30
BRD 66 43 72 51 / 10 10 10 20
HYR 58 40 68 47 / 10 10 10 30
ASX 56 39 57 43 / 10 10 10 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ020-021-
037.
WI...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR WIZ001.
LS...NONE.
&&
$$
SHORT TERM...TENTINGER
LONG TERM....GSF
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS HASTINGS NE
330 AM CDT SAT MAR 31 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT. THE PATTERN ALOFT
FEATURED SUBTLE RIDGING ACROSS THE CENTRAL PLAINS AND RIDGE IS
FORECAST TO EXPAND/BUILD THIS WEEKEND AS PACIFIC TROUGH REACHES THE
WESTERN CONUS. THIS WILL ALLOW A VERY WARM AIRMASS...ON THE ORDER
OF +3.3 STANDARD DEVIATIONS FOR H85 TEMPS...TO SETTLE ACROSS THE
CENTRAL PLAINS...AND FORECAST SOUNDINGS SUGGEST MIXING WILL BE
EVEN HIGHER THAN THIS LEVEL. RIDGE AXIS WILL SHIFT EASTWARD ON
SUNDAY AS UPPER TROUGH MOVES INTO THE ROCKIES WITH FLOW ALOFT
TRANSITIONING SOUTHWESTERLY. THE UPPER LOW IS FORECAST TO EMERGE
ONTO THE PLAINS MONDAY/MONDAY ALTHOUGH MODELS ARE NOT CONSISTENT
ON THE TRACK OF SYSTEM ATTM AND FOLLOWED CLOSER TO ENSEMBLES FOR
NOW.
HEADING INTO TODAY...MODELS HINT AT AN OUTSIDE CHCS FOR SOME LIGHT
CONVECTION PRIOR TO DAYBREAK IN PRESENCE OF SOME MID LEVEL WAA
ACROSS OUR NORTHERN COUNTIES. WILL MONITOR TRENDS OF THIS FOR THE
NEXT SEVERAL HOURS. THIS MORNING INTO EARLY AFTN A WEAK SURFACE
TROUGH WILL SLIDE EAST ACROSS NEBRASKA SHIFTING WINDS WESTERLY CAUSING
MOISTURE AXIS TO SHIFT EASTWARD. MODEL FORECAST SOUNDINGS SUGGEST
MIXING THIS AFTN AROUND H75 WITH WINDS AT THE TOP OF THE LAYER
ROUGHLY BETWEEN 11KTS AND 20KTS ACROSS OUR WESTERN CWA WHILE RH
VALUES DROP NEAR TO BELOW 20 PERCENT GENERALLY WEST OF HIGHWAY
281. LOCATIONS FROM ROUGHLY ORD TO LEXINGTON TO ARAPAHOE LOOK LIKE
THEY WILL MEET THE LOW RH CRITERIA FOR 3HRS WITH MAIN QUESTION
BEING WILL WINDS BE GUSTY ENOUGH FOR FIRE WEATHER HEADLINE.
SURFACE GRADIENT RELAXES SOME IN OUR WEST FOLLOWING BOUNDARY AND
MODELS SUGGEST SFC DPS MAY ACTUALLY RISE SOME IN AFTN AS WEST
WINDS TURN MORE SOUTHWESTERLY. FIRE WEATHER HEADLINE IS NOT A SLAM
DUNK DUE TO UNCERTAINTY IN WIND SPEEDS. HRRR WIND GUSTS DECREASE
ACROSS OUR WEST THIS AFTN AND THIS IS SUPPORTED BY 06Z NAM
SOUNDINGS WHERE WINDS AT THE TOP OF THE MIXED LAYER DECREASE
BETWEEN 21Z AND 00Z. GIVEN THE DECREASING WIND TREND WILL NOT GO
WITH HEADLINE ATTM AS OUR STRONGER WINDS WILL RESIDE EAST OF OUR
LOW RH AREA. THAT BEING SAID...DAY SHIFT WILL NEED TO CLOSELY
MONITOR FOR RED FLAG CONDITIONS.
HIGH TEMPERATURES THIS AFTERNOON LOOK TO BE NEAR OR AT RECORD
BREAKING LEVELS. RECORD FOR GRAND ISLAND TODAY IS 90F SET IN 1978.
RECORD FOR HASTINGS IS 89F SET IN 1946 AND RECORD FOR KEARNEY IS
88F SET IN 1946. CURRENT FORECAST HAS MAX TEMPS RIGHT AROUND THESE
RECORD READINGS AND MARCH WILL DEFINITELY END ON A HOT NOTE.
OVERNIGHT...THE SURFACE TROUGH DEEPENS ALONG THE HIGH PLAINS AND
MOISTURE MAKES A BETTER SURGE NORTH THRU KS INTO SOUTHERN NEBRASKA.
THE GFS MORE SO THAN THE NAM SUGGESTS POTENTIAL FOR SOME LOW CLOUD
DEVELOPMENT MAINLY ACROSS NC KS AND INCREASED CLOUD COVER AND
INCLUDED SOME PATCHY FOG FOR NOW.
ON SUNDAY...THE SURFACE LOW DEEPENS IN EASTERN COLORADO WITH
SOUTHERLY LLVL FLOW INCREASING ACROSS OUR CWA. MOISTURE AXIS ALIGNS
ACROSS THE EASTERN HALF TO TWO THIRDS OF OUR CWA WITH SFC DPS
PROGGED NEAR 60F IN OUR FAR EAST. THE UNSEASONALLY WARM/HOT AIRMASS
REMAINS IN PLACE ACROSS OUR REGION AND WE WILL SEE ANOTHER DAY OF
HIGHS IN THE UPPER 80S TO NEAR 90F WHICH ARE AGAIN NEAR OR ABOVE
RECORDS FOR THE FIRST OF APRIL. SUNDAY NIGHT...SFC COLD FRONTAL
BOUNDARY IN NW NEBRASKA ADVANCES SOUTHEAST INTO OUR CWA...REACHING
ALL BUT OUR SOUTHEAST ZONES BY MORNING. GFS SUGGESTS PCPN MAY
DEVELOP IN VCNTY OF FRONT MAINLY ACROSS OUR NORTHERN ZONES...HOWEVER
SREF AND OTHER MODELS ARE NOT OVERLY SUPPORTIVE OF THIS ATTM AND
WILL KEEP THINGS DRY FOR THE TIME BEING.
OF BIGGER CONCERN TOWARD DAYBREAK MONDAY AND THROUGH THE DAY ON
MONDAY IS THE INCREASING NORTH WINDS FOLLOWING FROPA. MODELS
INDICATE 6HR PRESSURE RISES BEHIND THE BOUNDARY IN EXCESS OF 10MB TO
OUR WEST ALONG THE HIGH PLAINS AND AROUND 8MB ACROSS OUR CWA MIDDAY
MONDAY. GRADIENT REMAINS TIGHT THROUGH THE DAY AND ALL INDICATIONS
FM MODELS SUGGEST WE WILL AT A MINIMUM REACH WIND ADVISORY CRITERIA
AND PORTIONS OF OUR WEST MAY BE NEAR HIGH WIND WARNING CRITERIA AND
WILL NEED TO MONITOR CLOSELY.
THE UPPER LOW SHIFTS EAST ONTO THE SOUTHERN PLAINS TOWARD THE TX/OK
PANHANDLES MONDAY NIGHT. GFS IS FARTHER NORTH WITH CENTER OF SYSTEM
THAN ECMWF AND HAVE PLAYED MIDDLE GROUND AND FOLLOWED CLOSER TO
ENSEMBLE SOLUTIONS FOR NOW. PCPN CHCS INCREASE MONDAY NIGHT FM
SOUTH TO NORTH IN INCREASING LIFT/DYNAMICS ASSOCIATED WITH UPPER
LOW. HAVE LEFT THUNDER OUT FOR NOW AS BETTER INSTABILITY REMAINS TO
OUR SOUTH BUT THIS MAY NEED TO BE ADJUSTED AS TRACK OF SYSTEM IS
REFINED.
.LONG TERM...TUESDAY THROUGH FRIDAY. BIGGEST CONCERN IN THE
EXTENDED LOOKS TO BE THE TRACK OF THE UPPER LOW WHICH IS FORECAST
AFFECT OUR AREA MID WEEK.
LATEST RUN OF THE EXTENDED MODELS STILL SHOWING PLENTY OF
DIFFERENCES ON TRACK OF THE UPPER LOW. OPERATIONAL GFS IS ONE OF
THE QUICKEST SOLUTIONS AS IT TAKES THE 500 MB LOW FROM THE OK
PANHANDLE AT 12Z TUE TO THE SOUTHERN EDGE OF OUR CWA BY 12Z
WED...AND THEN PUSHES IT QUICKLY EAST TO THE NORTHEAST TIP OF
MISSOURI BY 12Z THU. OF COURSE THE PERTURBATION RUNS OF THE GFS HAVE
THE LOW ALL OVER THE PLACE. THE EC IS A LITTLE QUICKER THAN THE
PREVIOUS EC RUN AS IT MOVES THE LOW FROM ERN NEW MEXICO AT 12Z TUES
TO A LITTLE SE OF DDC AT 12Z WED...AND THEN INTO NW ARKANSAS BY 12Z
THU. THE GEM IS SIMILAR IN SPEED WITH THE SYSTEM BUT A LITTLE
FURTHER SOUTH WITH THE TRACK. ALL OF THE MODELS BRING THIS SYSTEM ON
SHORE TODAY AND THEN SPLIT THE ENERGY...TAKING SOME NORTH AND SOME
SOUTH. HOPEFULLY THE PICTURE GETS A LITTLE MORE CLEAR IN THE NEXT 24
HRS AS THE LOW MOVES ONTO THE CONUS. BIGGEST IMPLICATIONS FOR US
WILL BE DURATION OF THE PRECIPITATION. COULD SEE OFF AND ON RAIN
TUESDAY AND WED WITH A NORTHERN TRACK...OR THE NORTHERN PART OF THE
CWA MIGHT MISS OUT IF IT GOES SOUTH. IT DOES APPEAR THAT IT SHOULD
PUSH EAST ON THUR AS NEXT UPSTREAM SYSTEM IS SET TO MOVE INTO THE
WESTERN U.S. WHICH SHOULD KEEP THINGS PROGRESSIVE. INSTABILITY
LOOKS MARGINAL ON TUESDAY SO WILL KEEP THUNDER OUT FOR NOW.
OTHERWISE TEMPERATURES SHOULD STILL BE ABOVE NORMAL WITH HIGHS IN
THE UPPER 50S ON TUESDAY AND THEN CLIMBING BACK TO NEAR 70 FOR
THURSDAY AND FRIDAY. ALSO --- IT STILL DOES NOT LOOK LIKE WE WILL
GET BELOW FREEZING THROUGH THE UPCOMING WORKWEEK.
&&
.AVIATION...06Z KGRI TAF. EXPECT VFR CONDITIONS THROUGH THE
FORECAST PERIOD. UPPER LEVEL RIDGE WILL MOVE INTO THE CENTRAL
PLAINS WITH WEAK SURFACE TROUGH JUST TO THE WEST. WINDS SHOULD
PICK UP AROUND LUNCHTIME AS WE MIX OUT WELL FOR THE AFTERNOON.
WINDS NOT PROJECTED TO BE OVERLY STRONG ALOFT SO WILL KEEP GUSTS
TO AROUND 20 KTS. OTHERWISE NOT EXPECTING MUCH IN THE WAY OF
CLOUDS EXCEPT FOR A FEW HIGH CLOUDS EARLY. MAY SEE A FEW CU IN THE
AFTERNOON ALTHOUGH CONVECTIVE TEMPS MAY BE HARD TO REACH IN SPITE
OF VERY WARM TEMPS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM/AVIATION...EWALD
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1220 AM CDT SAT MAR 31 2012
.AVIATION...06Z KGRI TAF. EXPECT VFR CONDITIONS THROUGH THE
FORECAST PERIOD. UPPER LEVEL RIDGE WILL MOVE INTO THE CENTRAL
PLAINS WITH WEAK SURFACE TROUGH JUST TO THE WEST. WINDS SHOULD
PICK UP AROUND LUNCHTIME AS WE MIX OUT WELL FOR THE AFTERNOON.
WINDS NOT PROJECTED TO BE OVERLY STRONG ALOFT SO WILL KEEP GUSTS
TO AROUND 20 KTS. OTHERWISE NOT EXPECTING MUCH IN THE WAY OF
CLOUDS EXCEPT FOR A FEW HIGH CLOUDS EARLY. MAY SEE A FEW CU IN THE
AFTERNOON ALTHOUGH CONVECTIVE TEMPS MAY BE HARD TO REACH IN SPITE
OF VERY WARM TEMPS.
&&
.PREV DISCUSSION... /ISSUED 754 PM CDT FRI MAR 30 2012/
UPDATE...HAVE GONE AHEAD AND UPDATED THE FORECAST IN ANTICIPATION
OF THE ONE FINAL STORM IN MITCHELL COUNTY FINALLY DIEING OFF BETWEEN
8 AND 9 PM WITH SUNDOWN. ENTERTAINING SOME THOUGHT OF A LATE NIGHT
OR NEAR DAWN ISOLATED SHOWER IN NORTHERN CWFA WITH DECENT WARM
ADVECTION. ALL FORECASTS DRY...BUT WRF AND HRRR BOTH HAVE SOME
IDEA OF THIS POSSIBILITY.
PREV DISCUSSION... /ISSUED 614 PM CDT FRI MAR 30 2012/
UPDATE...ADDED A FEW THUNDERSTORMS THROUGH ABOUT 8 PM ALONG A
WEAKISH SURFACE TROUGH WITH A VERY NARROW SURGE OF MOISTURE INTO
THE SOUTHEAST CWFA. AN ISOLATED STRONG STORM IS POSSIBLE.
ELSEWHERE ITS DRY AND NICE.
PREV DISCUSSION... /ISSUED 358 PM CDT FRI MAR 30 2012/
SHORT TERM...TONIGHT AND TOMORROW.
AS THE SHORT WAVE TROUGH AXIS PUSHES ACROSS THE CENTRAL PLAINS...A
FEW RAIN SHOWERS HAVE POPPED UP ACROSS NORTHEAST NEBRASKA. A FEW OF
THESE COULD BECOME THUNDERSTORMS AND MOVE ACROSS NORTHEAST PORTIONS
OF THE FORECAST AREA.
UPPER LEVEL ANALYSIS INDICATES MOSTLY ZONAL FLOW ACROSS THE CONUS
WITH A SHORT WAVE TROUGH ACROSS THE CENTRAL PLAINS. THE CORE OF THE
UPPER LEVEL JET REMAINS STRONGEST OFF THE WEST COAST...ALTHOUGH A
SECONDARY JET AXIS CONTINUES TO PUSH OFF THE EAST COAST. AT 500
MB...ZONAL FLOW CONTINUES ACROSS THE CONUS...WHILE A STRONG LOW
PRESSURE SYSTEM SPINS ACROSS CANADA. AT THE MID LEVELS...ZONAL FLOW
IS PREDOMINANT...ALTHOUGH THERE REMAINS A FEW SHORT WAVE TROUGHS
ACROSS THE REGION. ONE TROUGH REMAINS CENTERED OFF THE EAST OF THE
PLAINS WHILE A SECONDARY TROUGH BEGAN MOVING ACROSS THE CENTRAL
PLAINS TODAY. AT THE SURFACE A WEAK HIGH PRESSURE SYSTEM PASSED JUST
TO THE SOUTH OF THE REGION WHILE A WEAK LOW PRESSURE SYSTEM MOVED
ACROSS THE NORTHERN PLAINS FROM THE FRONT RANGE OF THE ROCKIES.
UPPER LEVEL RIDGING WILL BUILD ACROSS THE PLAINS ON SATURDAY...WHILE
THE MAIN CORE OF THE JET WRAPS AROUND THE TOP OF THE RIDGE. SKIES
ARE EXPECTED TO REMAIN PARTLY CLOUDY AS THE UPPER LEVEL JET NOSES
ACROSS THE REGION SATURDAY MORNING...AND WITH THE DEVELOPMENT OF
CUMULUS DURING THE AFTERNOON. 850 TEMPERATURES ARE EXPECTED TO SOAR
ACROSS THE REGION TO NEAR 20 DEGREES...COMBINED WITH STRONG BOUNDARY
LAYER MIXING...HIGH TEMPERATURES COULD EASILY REACH RECORD HIGHS
NEAR 90 DURING THE AFTERNOON TOMORROW. FIRE WEATHER THREATS WILL
REMAIN A CONCERN SATURDAY AFTERNOON AS RELATIVE HUMIDITY VALUES ARE
ALREADY FORECAST TO BE NEAR OR SLIGHTLY BELOW 20 PERCENT ACROSS THE
NORTHWEST. ALTHOUGH DEWPOINTS ARE QUITE LOW ALREADY...MODEL
SOUNDINGS INDICATE BOUNDARY LAYER MIXING TO NEAR 700 MB...THUS
REDUCING DEWPOINTS EVEN FARTHER. DECIDED NOT TO GO WITH ANY FIRE
WATCH AT THIS POINT...AS STRONGEST WINDS WILL REMAIN JUST UNDER
CRITERIA AND ACROSS THE NORTHEAST...VERSUS LOW RH VALUES ACROSS THE
NORTHWEST.
LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
FOR TUESDAY AND BEYOND...USED A BLEND OF 00Z OPERATIONAL ECMWF AND
ITS ENSEMBLES...TRANSITIONING TO ENSEMBLES TOWARD THE OUTER PERIODS
TO HELP TAKE A MIDDLE GROUND FOR MITIGATING DISCREPANCIES WITHIN THE
SYNOPTIC SCALE.
A PROMINENT UPPER LEVEL RIDGE WILL BE IN PLACE FOR SATURDAY NIGHT AS
A TROUGH MOVES ONTO THE WEST COAST...WITH A MODEST LOW-LEVEL JET
DEVELOPING OVER THE PLAINS. PROGGED SOUNDINGS INDICATE DRY CONDITIONS
WITH WARM AIR ADVECTION KEEPING LOW TEMPERATURES IN THE 50S.
SOUTH WIND WILL BECOME A BIT MORE BREEZY ON SUNDAY AS THE SURFACE
PRESSURE GRADIENT INCREASES AHEAD OF AN APPROACHING COLD FRONT. WITH
SOME INCREASED MOISTURE RETURN AT THE SURFACE...HIGHS WILL TOP OUT
IN THE MID 80S...MUCH ABOVE NORMAL BUT A TAD COOLER THAN HIGHS ON
SATURDAY. AS THE TROUGH MOVES EAST THROUGH THE ROCKY
MOUNTAINS...MODELS POINT TOWARD A CLOSED LOW DEVELOPING WITHIN THE
TROUGH BY SUNDAY NIGHT.
THE COLD FRONT WILL FINALLY BLOW THROUGH LATE SUNDAY NIGHT/EARLY
MONDAY MORNING...LATE ENOUGH FOR HIGHS TO BE QUITE WARM IN THE 50S
FOR MOST LOCATIONS. THERE IS STILL SOME UNCERTAINTY TO TIMING OF
THIS FRONT AND IT COULD ARRIVE A LITTLE LATER...GIVEN LATEST TRENDS.
THIS APPEARS TO BE A DRY COLD FRONT PASSAGE WITH NEARLY BONE DRY
MID-LEVELS BUT THERE COULD BE ENOUGH MOISTURE AND INSTABILITY TO
GIVE US A SMALL CHANCE OF SHOWERS AND PERHAPS THUNDERSTORMS WITH
SOME POSSIBLE INSTABILITY AHEAD OF THE FRONT. IMPRESSIVE HEIGHT RISES
WILL PROVIDE A STIFF NORTH WIND WITH SIGNIFICANTLY COLDER HIGHS IN
THE 60S...BUT STILL ABOVE NORMAL FOR THIS TIME OF YEAR. THERE COULD
BE A SMALL CHANCE OF ELEVATED POST-FRONTAL PRECIPITATION FOR MONDAY
INTO TUESDAY FOR PARTS OF THE CWA. LEFT SMALL CHANCES OF SHOWERS FOR
MONDAY NIGHT AS THE NORTHERN STREAM WAVE PASSES AND SOME LOWER
CHANCES IN THE SOUTH INTO TUESDAY...AS THEY COULD BE CLOSE ENOUGH TO
STILL BE UNDER THE INFLUENCE OF THE CLOSE LOW TO THE SOUTH.
INSTABILITY SHOULD BE LIMITED BY THEN.
MODELS DIFFER WITH THE TRACK OF THE CLOSED LOW FOR THE LAST FEW DAYS
OF THE EXTENDED FORECAST AFTER THE LOW SPILLS OUT INTO THE SOUTHERN
PLAINS BY AS THE ECMWF POINTS THIS LOW EAST ACROSS THE GULF
COAST...WHILE THE GFS SWINGS THE LOW A BIT FARTHER NORTHEAST INTO
THE MID-SOUTH. BOTH SOLUTIONS SHOULD KEEP CHANCES OF PRECIPITATION
SOUTH OF THE CWA.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1141 PM CDT FRI MAR 30 2012
.AVIATION...
06Z TAFS FOR KOMA...KLNK...KOFK.
DID NOT MENTION ANY FOG TOWARD MORNING...BUT MODELS DO SHOW SOME
INCREASE IN LOW LEVEL RH TOWARD SUNRISE. EXPECT CLOUDS TO BE MAINLY
ABOVE 12000 FEET THROUGH THE PERIOD. SOME SCATTERED CLOUDS POSSIBLE
AROUND 5000 FEET SATURDAY AFTERNOON.
MILLER
&&
.PREV DISCUSSION... /ISSUED 314 PM CDT FRI MAR 30 2012/
SHORT TERM...TONIGHT THROUGH MONDAY.
SEVERAL PERIODS OF ISOLD/SMALL POP CONVECTION CHANCES DOT SHORT
TERM FORECAST LANDSCAPE OTHERWISE TEMPERATURES ARE THE PRIMARY CONCERN.
FIRST SMALL PRECIP CHANCE IS EARLY THIS EVENING AS UPPER SHORT
WAVE ENERGY PUSHING TOWARD MO RIVER PER AFTERNOON STLT IMAGERY
FOCUSES ON CONVERGENT BOUNDARY WHICH AT 19Z STRETCHED FROM YKN-
TQE-OMA WITH SECOND CONVERGENT AREA APPROACHING LNK AND OLU.
SELECTIVE MODELS...I.E. HRRR+4KM WRF HAVE GENERATED SMALL QPF CLUSTER
WHICH PUSHES INTO SWRN IA BEFORE WEAKENING FAIRLY QUICKLY WITH
LOSS OF HEATING. MEANWHILE RUC KEPT MID LAYER PRETTY DRY/WELL
MIXED CAP AND GFS NOT OVERLY SUPPORTIVE EITHER. WILL EXTEND SMALL
POPS ERN ZONES EARLY THIS EVENING...HOWEVER...DUE TO CONVERGENT
CU AND OCNL WEAK CELLS THAT HAD CONTD TO DEVELOP ON RADAR IN
19-20Z PERIOD.
OTHERWISE FLAT UPPER RIDGING SPREADING ACROSS PLAINS ON SATURDAY
WILL BRING EVEN WARMER READINGS TO AREA WITH NEAR RECORD HIGHS
LIKELY AT OFK/OMA AND LNK. DID NOT INCLUDE LATE AFTERNOON POPS AT
THIS TIME NEAR H85 THERMAL AXIS NEAR OR N OF OMA AND POINTS
EWD...BUT CONVECTIVE TEMPERATURES COULD BE REACHED PER NAM
FORECAST SOUNDINGS. AREA WILL HAVE TO BE MONITORED...BUT LEFT OUT
DUE TO AREA APPEARS WILL EXTEND IN GENERAL UPPER RIDGE AREA.
UPPER RIDGE AMPS/SHIFTS EAST A LITTLE SUNDAY SPREADING EVEN
WARMER H85 TEMPS OVER AREA. RECORD HIGHS AGAIN APPROACHED MANY
LOCATIONS AS IT APPEARS MOST HIGHS SHOULD BE A FEW DEGREES WARMER
THAN THOSE EXPECTED ON SATURDAY.
LEFT IN SMALL POPS WITH FRONT ON MONDAY ALTHOUGH THERE WAS LITTLE
UPPER SUPPORT WITH FRONT PUSHING INTO NEGATIVELY TILTED UPPER
RIDGE AS ENERGY SPLITS. HOWEVER...WITH VERY WARM TEMPERATURES
AHEAD OF THIS STRONGER COLD FRONT...AND DELAYED TIMING A BIT...DID
BOOST MAX TEMPS A CATEGORY OR SO SERN 1/2-2/3RDS OF THE AREA.
LONG TERM...MONDAY NIGHT THROUGH FRIDAY.
FOCUS TURNS TO HOW FAR NORTH UPPER LOW WILL DRIFT FOR POSSIBLE
PRECIP CHANCES...IF IT LIFTS FAR ENOUGH N...OR FOR POTENTIAL
FROST/ISOLD FREEZING TEMPERATURES IF PATTERN DEVELOPS INTO A
STALLED REX-LIKE BLOCK WITH UPPER LOW FARTHER SOUTH. ALTHOUGH
LOWERED A FEW LOW TEMPERATURES INTO UPPER 30S-40ISH WED AM DID NOT
STRAY TOO FAR FROM MODEL BLEND WITH OTHER LOW TEMPS AS TOO MANY
UNCERTAINTIES PERSIST. DID ALSO LOWER MAX TEMPS A LITTLE IN WED-
THU PERIOD AND SPREAD POPS A LITTLE FARTHER NW MON NIGHT INTO TUE.
HOWEVER...ENTIRE PERIOD WILL LIKELY SEE CHANGES...AND AT LEAST
MODERATE ONES...AS CONFIDENCE WAS LOW WITH HOW PATTERN WILL
DEVELOP.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ELKO NV
1125 PM PDT FRI MAR 30 2012
.SYNOPSIS...A FEW SHOWERS WILL LINGER THROUGH THE EARLY MORNING
HOURS. STRONG GUSTY WINDS WILL IMPACT THE REGION SATURDAY AHEAD
OF A STRONG SURFACE COLD FRONT. BLOWING DUST AND ISOLATED
THUNDERSTORMS WILL DEVELOP AHEAD OF THE FRONT. SATURDAY NIGHT
TEMPERATURES WILL RAPIDLY DROP BEHIND THE FRONT WITH SCATTERED
SNOW SHOWERS EXPECTED ON SUNDAY. A WARMING TREND AND DRIER WEATHER
IS EXPECTED FOR THE BEGINNING OF NEXT WEEK.
&&
.UPDATE...ANOTHER WEAK SHORTWAVE IS GENERATING SOME SHOWERS ACROSS
THE CWFA. UPDATED THE FORECAST TO INCLUDE ISOLATED SHOWERS ACROSS
MAINLY NORTHERN ZONES. NONE OF THE MODELS ALLUDED TO THIS LAST
WAVE. AND CURRENT MODELS ARE SHOWING AMPLIFICATION OF RIDGING THAT
SHOULD FORCE THE MOISTURE NORTH SO JUST UPDATED THROUGH 12Z THIS
MORNING...THEN DRY. WILL KEEP AN EYE ON THIS FOR THE NEXT PACKAGE
PRIOR TO THE STRONG WIND EVENT TODAY.
&&
.PREV DISCUSSION... /ISSUED AT 633 PM /
SYNOPSIS...STRONG GUSTY WINDS WILL IMPACT THE REGION SATURDAY
AHEAD OF A STRONG SURFACE COLD FRONT. BLOWING DUST AND ISOLATED
THUNDERSTORMS WILL DEVELOP AHEAD OF THE FRONT. SATURDAY NIGHT
TEMPERATURES WILL RAPIDLY DROP BEHIND THE FRONT WITH SCATTERED
SNOW SHOWERS EXPECTED ON SUNDAY. A WARMING TREND AND DRIER WEATHER
IS EXPECTED FOR THE BEGINNING OF NEXT WEEK.
UPDATE...WINDS HAVE DECREASED OVER HUMBOLDT COUNTY THIS EVENING
SO HAVE CANCELLED THE WIND ADVISORY. WINDS ARE STILL EXPECTED TO
INCREASE SIGNIFICANTLY SATURDAY MORNING FOR A HIGH WIND WARNING
OVER THE ENTIRE CWA. SEE PREVIOUS DISCUSSION.
PREV DISCUSSION... /ISSUED AT 311 PM /
SHORT TERM...TONIGHT THROUGH MONDAY. CURRENT WATER VAPOR IMAGERY
AND RUC ANALYSIS SHOWS A STRONG PACIFIC NORTHWEST JET MAX OF
130KTS AHEAD OF A DIGGING PACIFIC 500MB TROUGH. THE UPPER LEVEL
JET WILL CONTINUE TO PROGRESS EASTWARD INTO THE GREAT BASIN
TONIGHT. STILL LOOKING LIKE AN IMPRESSIVE WIND EVENT DURING THE
DAY TOMORROW ACROSS ALL ZONES. ALL HIGH WIND INDICES ARE LOOKING
GOOD WITH 700/500MB WIND ANOMALIES OF +3 TO 4 STANDARD
DEVIATIONS...MAV GUIDANCE FOR ALL TAF LOCATIONS IS SHOWING SOLID
32-38KTS...MIXING HEIGHTS ARE FORECASTED TO REACH 550MB...AND A
993 SURFACE LOW OVER SOUTHERN IDAHO WILL HELP ENHANCE LOW LEVEL
NORTH/SOUTH CHANNELING OF WINDS. HAVE UPGRADED ALL ZONES TO A HIGH
WIND WARNING FROM THE ONGOING WATCH. WILL MOST LIKELY HAVE SOME
BLOWING DUST TOMORROW WITH THE PROLONGED WIDE SPREAD WINDS. IN
ADDITION THERE COULD BE A FEW ISOLATED STRIKES DURING THE
AFTERNOON HOURS ALONG THE ID/OR/NV BORDER.
SATURDAY NIGHT THE FRONT WILL PUSH THROUGH THE AREA...WITH A VERY
TIGHT TEMP GRADIENT BEHIND THE FRONT. SHOULD SEE 20-30 DEGREE
TEMPS DROPS IN JUST A FEW HOURS BEHIND THE FRONT. PRECIP IS STILL
TRENDING LIGHT BEHIND THE FRONT...SO KEPT QPF AND SNOW AMOUNTS ON
THE LOW SIDE. MOST AREA WILL ONLY SEE A FEW HUNDREDTHS OF LIQUID
WITH MAYBE A TRACE OF SNOW ABOVE 5500FT. THERE STILL COULD BE A
FEW INCHES ACROSS THE MOUNTAINS OF EASTERN NV BY DAYBREAK SUNDAY.
SUNDAY A COLD UPPER LEVEL 500MB TROUGH WILL BE CENTERED OVER THE
REGION...LEADING TO STEEP LOW LEVEL LAPSE RATES. CONVECTIVE SNOW
SHOWERS WILL CONTINUE THROUGH THE DAY...WITH A FEW ADDITIONAL
INCHES OF ACCUMULATIONS ACROSS THE MOUNTAINS...ONLY A DUSTING IS
EXPECTED ACROSS THE WARMER VALLEYS. WARMER IS RELATIVE AS HIGHS
ARE ONLY EXPECTED TO REACH THE LOW TO MID 40S ACROSS THE VALLEYS
WITH BELOW ZERO TEMPS IN THE MOUNTAINS. RIDGING QUICKLY RETURNS BY
MONDAY...BRINGING A NICE DAY WITH MOSTLY CLEAR SKIES AND TEMPS
REBOUNDING INTO THE LOW 50S ONCE AGAIN...AFTER A COLD START TO THE
DAY WITH LOWS IN THE LOW 20S.
LONG TERM...MONDAY NIGHT THROUGH NEXT THURSDAY. GFS AND EURO IN
GOOD AGREEMENT MONDAY NIGHT THROUGH LATE TUESDAY NIGHT WITH
INCREASING SOUTHWEST FLOW FROM APPROACHING LONG WAVE TROUGH OFFSHORE
IN THE PACNW. AFTER THAT...THE GFS BECOMES SLIGHTLY DEEPER AND
SLIGHTLY NEGATIVELY TILTED AND CLOSES OFF A LOW AND MOVES IT INTO
THE INTERIOR PACIFIC NW...TRAILING A VORT LOBE OVER THE GREAT BASIN.
THE EURO HOLD BACK THIS LOW WHILE CLOSING IT OFF BUT MORE
SHALLOW...AND POSITIVELY TILTING THE TRAILING TROF. HENCE IT BRINGS
IN THE COLD FRONT...HUMIDITY...AND PRECIP LATER. HAVE OPTED TO GOT
WITH THE FASTER GFS. THE DRY SOUTHWEST FLOW WILL KEEP THINGS DRY
THROUGH WEDNESDAY MORNING WHEN A LITTLE SHORT WAVE WILL CROSS
NORTHERN NEVADA AND PROVIDE VERY LOW CHANCE POPS ALONG THE IDAHO
BORDER WITH SLIGHT CHANCE POPS IN NORTHERN NEVADA WITH BARELY DOUBLE
DIGIT POPS IN CENTRAL AND EASTERN NEVADA. DRY SOUTH TO SOUTHWEST
WINDS WILL INCREASE IN SPEED IN ADVANCE OF THE WAVE APPROACHING
TUESDAY NIGHT/WEDNESDAY MORNING. TEMPS SHOULD BE COOLER THAN OUR
CURRENT ABOVE NORMAL PATTERN. MINS WILL BE LOWER WITH FEWER CLOUDS
AND LIGHTER WINDS. AS CLOSED GFS LOW MOVES NORTH OF THE GREAT BASIN
EXPECTING TRAILING LOW LEVEL TROUGH TO CROSS THE STATE AND INCREASE
SOUTH-SOUTHWEST WINDS IN ADVANCE. MIGHT POSSIBLY MEET ADVISORY
CRITERIA LATE WEDNESDAY AND EARLY THURSDAY. POPS...TEMPS...REMAIN
CONSTANT DURING THE WED-THURSDAY FRAME.
AVIATION...A PACIFIC FRONT IS APPROACHING THE NORTHERN GREAT BASIN
AND WINDS AND CLOUDS WILL INCREASE OVER NIGHT AND ESPECIALLY ON
SATURDAY. ISOLATED SHOWERS WILL OCCUR NEAR KWMC AND KEKO ON
SATURDAY. CIGS AND VSBYS WILL BE TECHNICALLY VFR AT ALL SITES BUT
MOUNTAIN TOPS WILL BE POTENTIALLY OBSCURED AT ALL SITES. WINDS WILL
INCREASE TO OVER 35 KNOTS AT ALL SITES SATURDAY AFTERNOON WITH OVER
45 KNOTS AT KEKO...AND OVER 50 KNOTS AT KELY AND KTPH.
FIRE WEATHER...AN INTENSE COLD FRONT WILL ENTER THE FIRE DISTRICT
SATURDAY AFTERNOON AND EXIT EARLY SUNDAY MORNING. MIN RH WILL
GENERALLY BE AROUND 15% AND WIND GUSTS COULD REACH TO AROUND 70
MPH AS THE FRONT MOVES THROUGH SATURDAY AFTERNOON AND EVENING.
FUELS CONTINUE TO APPEAR NON-CRITICAL. AFTER COLLABORATION WITH
SPC...WILL HAVE A SEE-TEXT BOX FOR NORTHERN NYE COUNTY. FIRE
MANAGERS ARE URGED TO USE EXTREME CAUTION AND REFRAIN FROM ALL
BURNING SATURDAY AFTERNOON AND EVENING.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING FROM 11 AM TO 11 PM PDT SATURDAY FOR EXTREME
EASTERN ELKO COUNTY...NORTHERN ELKO COUNTY...NORTHERN LANDER
COUNTY AND NORTHERN EUREKA COUNTY...NORTHERN NYE COUNTY...RUBY
MOUNTAINS/EAST HUMBOLDT RANGE...SOUTHERN LANDER COUNTY AND
SOUTHERN EUREKA COUNTY...SOUTHWEST AND SOUTH CENTRAL ELKO
COUNTY...WHITE PINE COUNTY.
HIGH WIND WARNING FROM 8 AM TO 11 PM PDT SATURDAY FOR HUMBOLDT
COUNTY.
&&
$$
92/99
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1134 PM CDT FRI MAR 30 2012
.AVIATION...
FOR THE 06Z TAFS...VFR CONDITIONS ARE ANTICIPATED AT KDHT AND KGUY.
THERE IS A VERY REMOTE POSSIBILITY OF MVFR OR IFR CONDITIONS AT KGUY
09-13Z...BUT CONFIDENCE OF OCCURRENCE IS TOO LOW TO MENTION AT THIS
TIME. AT KAMA...HAVE MODERATE TO HIGH CONFIDENCE OF MVFR...POSSIBLY
AS LOW AS LIFR...CONDITIONS DEVELOPING 09-13Z. OTHERWISE...VFR
CONDITIONS WILL PREVAIL.
JACKSON
&&
.PREV DISCUSSION... /ISSUED 525 PM CDT FRI MAR 30 2012/
AVIATION...
FOR THE 00Z TAFS...VFR CONDITIONS ARE ANTICIPATED. THERE IS A VERY
MINIMAL THREAT FOR IFR CIGS TO DEVELOP AT KAMA 09-14Z...BUT
THINK THESE SHOULD REMAIN EAST OF THE TAF SITE.
JACKSON
PREV DISCUSSION... /ISSUED 420 PM CDT FRI MAR 30 2012/
DISCUSSION...
RECORD OR NEAR RECORD HEAT EXPECTED THIS WEEKEND...FOLLOWED BY A COOL
DOWN...RAIN CHANCES...AND POSSIBLY STRONG NORTHERLY WINDS EARLY NEXT
WEEK.
FOR THE REST OF THIS AFTERNOON AND EVENING...REMOVED THE ISOLATED
THUNDERSTORM MENTION. STILL A GOOD AMOUNT OF LOW-LEVEL MOISTURE AND
POTENTIAL INSTABILITY ACROSS CENTRAL AND EASTERN AREAS...BUT DON/T
THINK WE/LL TAP INTO IT. LAPS AND RUC ANALYSIS DATA SHOW 75 J/KG OR
MORE OF CIN STILL IN PLACE ACROSS THE EAST...AND ANY FORCING FROM
MID-LEVEL SHORTWAVE WILL BE SHIFTING INTO WESTERN OK WITH SUBSIDENCE
BUILDING IN BEHIND THIS WAVE AND AHEAD OF SHORTWAVE RIDGE TO THE
WEST. VERY FLAT CU FIELD THAT GREW OUT OF THIS MORNING/S STRATUS
CONTINUES TO PUSH EASTWARD LATE THIS AFTERNOON IN ASSOCIATION WITH
WEAK LIFT FROM AFOREMENTIONED SHORTWAVE...WITH MAINLY CLEAR SKIES TO
THE WEST ASIDE FROM A FEW FAIR WEATHER CU. AFTER MIDNIGHT...MAY SEE
SOME FOG DEVELOP ONCE AGAIN. LOW-LEVELS WILL REMAIN MOIST AND WINDS
WILL BE LIGHT UNDER MOSTLY CLEAR SKIES...POTENTIALLY LEADING TO SOME
RADIATION FOG.
SHORTWAVE UPPER RIDGING WILL BE IN PLACE ON SUNDAY...WHILE A WEAK LEE
TROUGH DEVELOPS AT THE SURFACE. SOUTH/SOUTHWEST WINDS WILL RETURN BUT
LOOK TO REMAIN FAIRLY LIGHT /AOB 15 MPH/. SHOULD BE A NICE SPRING DAY
AS TEMPS CLIMB INTO THE 80S. RECORD HIGH OF 87F MAY FALL AT KDHT.
MODELS HAVE ALL COME ON BOARD WITH CLOSING OFF AN UPPER LOW AS THE
NEXT UPPER TROUGH WORKS ACROSS THE SOUTHERN ROCKIES. THIS LEADS TO A
SLOWER PROGRESSION OF THE UPPER SYSTEM...AND IN TURN...WINDS ON
SUNDAY STILL LOOKING WEAKER THAN ONCE THOUGHT EARLIER THIS WEEK. IT
WILL STILL BE WINDY AS THE SURFACE GRADIENT TIGHTENS IN RESPONSE TO A
DEVELOPING LOW OVER THE CENTRAL HIGH PLAINS...BUT CERTAINLY NOTHING
OUT OF THE ORDINARY FOR THIS PART OF THE COUNTRY. GENERALLY LOOKING AT
SOUTHWEST WINDS IN THE 20-30 MPH RANGE WITH GUSTS UP TO 40 MPH...AND
LIKELY A LITTLE WEAKER THAN THIS IN THE EAST. HIGHS EXPECTED TO SOAR
INTO THE UPPER 80S TO MID 90S...PUTTING RECORDS IN JEOPARDY AT
KAMA...KDHT...AND KBGD.
STRONG COLD FRONT IS EXPECTED TO PUSH THROUGH MONDAY...AND NORTH
WINDS MAY REACH ADVISORY LEVELS IN THE TIGHT GRADIENT. WILL SEE MUCH
COOLER TEMPS MONDAY WITH ACTUAL READINGS DEPENDING ON THE FRONTAL
TIMING...AND EVEN COOLER ON TUESDAY. QUESTION THEN BECOMES HOW LONG
THE CLOSED LOW WILL LINGER AROUND THE AREA. GFS AND CMC GEM ARE
FAIRLY PROGRESSIVE WITH THE SYSTEM...PUSHING IT EAST BY TUESDAY
NIGHT. LATEST ECMWF IS SLOWER...KEEPING POTENTIAL FOR WRAPAROUND RAIN
SHOWERS INTO WEDNESDAY. FOR NOW WILL BRING CHANCES FOR RAIN SHOWERS
INTO THE WEST MONDAY AFTERNOON...EXPAND THEM AREA WIDE MONDAY
NIGHT...AND THEN LINGER THEM IN THE NORTHEAST TUESDAY BEFORE DRYING
THINGS OUT TUESDAY NIGHT. ONCE THE UPPER LOW PULLS EAST...WILL SEE
REBOUNDING TEMPERATURES AND DRY CONDITIONS MID TO LATE NEXT WEEK.
KB
FIRE WEATHER...
VERY WARM TEMPERATURES CAN BE EXPECTED ACROSS THE PANHANDLES THIS
WEEKEND...WITH HIGHS FORECAST TO REACH THE 80S SATURDAY AND UPPER 80S
TO MID 90S SUNDAY. RELATIVE HUMIDITIES WILL FALL TO 10 TO 20 PERCENT
ACROSS THE WESTERN AND CENTRAL PANHANDLES SATURDAY...BUT WINDS ARE
FORECAST TO REMAIN BELOW 15 MPH...KEEPING FIRE WEATHER CONDITIONS
BELOW ELEVATED LEVELS. SOUTHWEST WINDS WILL INCREASE ON SUNDAY AS
SURFACE LOW PRESSURE DEVELOPS OVER THE CENTRAL HIGH PLAINS. A FIRE
WEATHER WATCH HAS BEEN ISSUED FOR THE WESTERN AND CENTRAL PANHANDLES
SUNDAY WHERE SOUTHWEST WINDS ARE EXPECTED TO INCREASE TO 20 TO 30 MPH
WITH HIGHER GUSTS. ACROSS THE EASTERN PANHANDLES...WINDS ARE FORECAST
TO BE SLIGHTLY WEAKER IN THE 15 TO 25 MPH RANGE. RELATIVE HUMIDITIES
WILL FALL TO 5 TO 15 PERCENT AREA WIDE. A STRONG COLD FRONT WILL MOVE
THROUGH ON MONDAY...WITH STRONG NORTH WINDS DEVELOPING BEHIND THE
FRONT. RELATIVE HUMIDITIES EXPECTED TO STAY AROUND 20 PERCENT OR
HIGHER DUE TO COOLER CONDITIONS...BUT THE WINDS WILL BE STRONG
LEADING TO ELEVATED FIRE WEATHER CONDITIONS. ELEVATED FIRE WEATHER
CONDITIONS MAY RETURN LATE NEXT WEEK AS TEMPERATURES WARM BACK UP AND
SOUTH/SOUTHWEST WINDS RETURN.
KB
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...FIRE WEATHER WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING
FOR THE FOLLOWING ZONES: ARMSTRONG...CARSON...DALLAM...DEAF
SMITH...HANSFORD...HARTLEY...HUTCHINSON...MOORE...OLDHAM...
POTTER...RANDALL...SHERMAN.
OK...FIRE WEATHER WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING
FOR THE FOLLOWING ZONES: CIMARRON...TEXAS.
&&
$$
JJ/JC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
339 AM EDT SAT MAR 31 2012
.SYNOPSIS...
A WEAK COOL FRONT WILL SWEEP SOUTHEAST THROUGH THE MID APPALACHIAN
AND MID ATLANTIC REGION TODAY...ACCOMPANIED BY SCATTERED TO WIDELY
SCATTERED SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD
SOUTHEAST INTO THE AREA LATER THIS AFTERNOON...AND PERSIST
THROUGH SUNDAY...ENDING THE THREAT FOR RAIN AS SKIES GRADUALLY
CLEAR.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 335 AM EDT SATURDAY...
WEAK COOL FRONT PROGRESSING SOUTHEAST OUT OF THE OHIO VALLEY WILL
SWEEP SOUTHEAST THROUGH THE MOUNTAINS THIS MORNING...AND CONTINUE
EAST MOVING THROUGH THE PIEDMONT COUNTIES THIS AFTERNOON. LATEST
RUN OF THE HIGH RESOLUTION WRFARL AND HRRR MODELS DOING A VERY
GOOD JOB OF DEPICTING THE MOVEMENT...TIMING...AND AREAL COVERAGE
OF LINEAR SCATTERED CONVECTION IN THE VICINITY OF THE FRONT...WITH
MORE STRATIFORM AREA OF PRECIPITATION ADVANCING NORTHEAST THROUGH
THE SOUTHERN COUNTIES WHERE ISENTROPIC LIFT IS MAXIMIZED.
EXPECT TO SEE SOUTHERN STRATIFORM AREA OF PRECIPITATION MAINLY
SOUTH OF HIGHWAY 460 TO MOVE EAST OF THE BLACKSBURG FORECAST AREA
BY/SHORTLY AFTER DAYBREAK AS BEST ISENTROPIC LIFT MOVES EAST OF
REGION...AND AS LOWER TROPOSPHERIC WINDS GRADUALLY VEER INTO MORE
OF A DOWNSLOPING COMPONENT AS SURFACE LOW PRESSURE MOVES EAST TO
THE DELMARVA AREA.
MEANWHILE...FURTHER NW NEAR THE SURFACE FRONT...PAST SEVERAL HOURS
OF SATELLITE PICTURES AND SURFACE OBSERVATIONS SHOWING A MARKED
DECREASE OF CONVECTIVE ACTIVITY ALONG/NEAR FRONT DUE TO LIMITED
FORCING AND NEGLIGIBLE THERMODYNAMIC SUPPORT. SOME STRAY
SHOWERS/ISOLATED STORMS MAY REACH THE WESTERN TIER COUNTIES
SHORTLY BEFORE/AROUND DAYBREAK...SUPPORTED BY AT LEAST SOME
LIMITED UPSLOPING ALONG THE WESTERN FLANKS OF THE
APPALACHIANS...BUT ANY REIGNITING ALONG THE FRONT WILL LIKELY COME
LATER IN THE AFTERNOON AFTER THERMODYNAMIC SUPPORT INCREASES...AND
BY THEN...FRONT/SURFACE TROF LIKELY TO SOUTH AND EAST OF THE
BLACKSBURG FORECAST AREA.
DESPITE ARRIVAL AND PASSAGE OF FRONT AND ASSOCIATED CLOUDS...LITTLE
CHANGE IN AIR MASS IS EXPECTED DURING THE DAY SINCE DEEPER COOL
AIR LAGS WELL BEHIND WIND SHIFT. COMBINATION OF LINGERING CLOUDS
IN UPSLOPE AREAS OF THE WEST AND AT LEAST A FEW DEGREE REDUCTION
IN 850 MILLIBAR TEMPERATURE SHOULD PREVENT AFTERNOON READINGS
FROM REACHING THOSE EXPERIENCED ON FRIDAY. HOWEVER...DOWNSLOPING
WINDS FOLLOWING PASSAGE OF FRONT/TROF MAY VERY WELL ALLOW FOR A WARMER
DAY ACROSS MUCH OF THE PIEDMONT. ALL AND ALL...EXPECT TEMPERATURES
TO CONTINUE TO BE 10-15 DEGREES ABOVE NORMAL FOR THE LAST DAY OF
THE MONTH...GENERALLY 60S ACROSS THE WESTERN MOUNTAINS TO NEAR 80
ACROSS THE PIEDMONT. THIS WILL ENSURE THAT MOST CLIMATOLOGICAL
SITES END UP BREAKING OR BEING IN THE TOP SEVERAL WARMEST MARCHES
ON RECORD.
DRY SURFACE RIDGE OF HIGH PRESSURE BUILDING IN FROM THE NORTH AND
WEST TONIGHT SHOULD ALLOW FOR CLEARING SKIES WITH GOOD RADIATIVE
COOLING POTENTIAL. READINGS SHORTLY BEFORE DAYBREAK ON SUNDAY
EXPECTED TO RANGE FROM THE MID 30S TO LOWER 40S IN THE
MOUNTAINS...WHERE SOME PATCHY FROST MAY OCCUR IN SOME OF THE
DEEPER MOUNTAIN VALLEYS...TO THE MID AND UPPER 40S ACROSS THE
PIEDMONT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM EDT SATURDAY...
ON SUNDAY...WE ARE EXPECTING HIGH PRESSURE TO SETTLE OVER THE AREA
BY THE MORNING. A STRONGER NOSE OF HIGH PRESSURE IS EXPECTED TO HEAD
SOUTH THROUGH THE GREAT LAKES AREA LATER IN THE DAY. THIS FEATURE
MAY PROMPT A BACK DOOR COLD FRONT INTO THE AREA...WITH THE POTENTIAL
FOR SOME ISOLATED SHOWERS ALONG IT LATE IN THE AFTERNOON INTO SUNDAY
EVENING. AS THE BACK DOOR FRONT CONTINUES SOUTH THROUGH THE AREA
SUNDAY NIGHT...ANTICIPATE ISOLATED COVERAGE ACROSS
WESTERN...NORTHERN...AND EASTERN SECTIONS OF THE REGION. COVERAGE
MAY SCATTERED OVER SECTIONS OF SOUTHEAST WEST VIRGINIA.
THIS FRONT WILL BECOME STALLED OVER THE WESTERN THIRD OF THE AREA BY
MONDAY MORNING. DURING THE DAY MONDAY...AN AREA OF LOW PRESSURE WILL
BE MOVING EASTWARD THROUGH THE CENTRAL PART OF THE U.S. WIND FLOW
IN ADVANCE OF THIS FEATURE WILL TURN SOUTHERLY ACROSS THE WESTERN
GULF OF MEXICO...AND ADVECT INTO OUR REGION FROM THE SOUTHWEST. THE
RESULT WILL BE INCREASING COVERAGE OF SHOWERS ALONG THE STALLED
FRONT THANKS TO THE INCREASED MOISTURE. THE FRONT ITSELF WILL ALSO
TAKE ON MORE OF THE NATURE OF A WARM FRONT AND HEAD ACROSS THE AREA
BY MONDAY NIGHT.
ON TUESDAY...THE LOW WILL HEAD EASTWARD NEAR THE PA/MD LINE AND ITS
ASSOCIATED COLD FRONT WILL SWEEP THROUGH THE AREA. WE ARE
ANTICIPATING INCREASED CHANCES OF SHOWERS AND THUNDERSTORMS DURING
THE DAY...ESPECIALLY ACROSS THE MOUNTAINS. AREAS ALONG AND EAST OF A
FARMVILLE TO DANVILLE LINE MAY NOT SEE ANY ACTIVITY UNTIL TUESDAY
EVENING. BY TUESDAY NIGHT... MOST OF THE PRECIPITATION WILL BE SOUTH
OF THE AREA IN ASSOCIATION WITH THE COLD FRONT. LINGERING SHOWERS
WILL STILL BE POSSIBLE ACROSS THE AREA...ESPECIALLY OVER SOUTHEAST
WV WHERE NORTHWEST FLOW UPSLOPE SHOWERS ARE EXPECTED.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
WITH THE COLD FRONT PASSING THROUGH OUR AREA ON TUESDAY NIGHT AND
WEDNESDAY MORNING...EXPECT ANOTHER LARGE DOME OF CANADIAN HIGH
PRESSURE TO BUILD INTO THE UPPER MIDWEST...BRINGING OUR TEMPERATURES
MUCH CLOSER TO NORMAL FOR THE FIRST WEEK OF APRIL. WITH HIGH
PRESSURE MAINTAINING ITS CONTROL THROUGH THE BEGINNING OF NEXT
WEEKEND...THE ONLY WEATHER CONCERNS WILL BE CHILLY OVERNIGHT
TEMPERATURES...WHICH MAY APPROACH FREEZING ACROSS PARTS OF SOUTHEAST
WEST VIRGINIA...AND MAY RESULT IN OVERNIGHT FROST ELSEWHERE ACROSS
THE MOUNTAINS.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
AS OF 155 AM EDT SATURDAY...
MAINLY VFR WEATHER EXPECTED OVER THE ENTIRE BLACKSBURG TERMINAL
FORECAST AREA (KLWB...KBLF...KBCB...KROA...KLYH...KDAN) THROUGH
THE WEEKEND.
HOWEVER...APPROACH OF COOL FRONT AND ASSOCIATED SCATTERED SHOWERS
AND THUNDERSTORMS MAY SUPPORT SOME LOCALIZED MVFR FLIGHT
RESTRICTIONS TO BOTH CEILING AND VISIBILITY ALONG THE WESTERN
FLANKS OF THE APPALACHIANS THIS MORNING...MAINLY IN WEST
VIRGINIA.
PASSAGE OF COOL FRONT AND SURFACE RIDGE OF HIGH PRESSURE BUILDING
SOUTHEAST INTO THE MID APPALACHIAN AND MID ATLANTIC REGION THIS
AFTERNOON THROUGH SUNDAY SHOULD SUPPORT CLEARING CONDITIONS ACROSS
THE ENTIRE AREA.
THE NEXT THREAT FOR FLIGHT RESTRICTIONS WILL OCCUR LATE SUNDAY
NIGHT OR ON MONDAY...POSSIBLY CONTINUING INTO THE MID WEEK
PERIOD AS ANOTHER RIDGE OF HIGH PRESSURE BUILDS SOUTHWEST OUT OF
NEW ENGLAND. UPSLOPING WINDS ACROSS THE EASTERN FLANKS OF THE BLUE
RIDGE...WITH WEAK SHORT WAVES AND MOISTURE STREAMING NORTHEAST
OVER A STALLED FRONT OVER/NEAR THE AREA...MAY SET THE STAGE FOR
MVFR (AND POTENTIALLY LOWER) FLIGHT RESTRICTIONS INTO THE MID WEEK
PERIOD...ESPECIALLY OVER/IN THE MOUNTAINS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WERT
NEAR TERM...WERT
SHORT TERM...DS
LONG TERM...NF
AVIATION...WERT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
315 AM CDT SAT MAR 31 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
315 AM CDT SAT MAR 31 2012
MAIN FORECAST CONCERNS ARE ON CONVECTION CHANCES TONIGHT THROUGH
MONDAY NIGHT AS WELL AS TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED A POTENT SHORTWAVE TROUGH OFF THE CALIFORNIA COASTLINE BY
ABOUT 500 MILES...RIDGING BUILDING DOWNSTREAM FROM THE FOUR CORNERS
REGION INTO WYOMING AND SOUTH DAKOTA...AND A WEAK SHORTWAVE OVER
EASTERN IOWA. CONDITIONS ARE DRY OVER THE FORECAST AREA NOW BEING IN
THE WAKE OF THE WEAK SHORTWAVE...PLUS PLENTY OF DRY AIR EXISTS ABOVE
850MB...NOTED ON THE 00Z MPX AND GRB SOUNDINGS. HOWEVER...A LOW
STRATUS DECK OF CLOUDS PERSISTS FROM MICHIGAN WESTWARD TO I-35...
RESULTING FROM MOISTURE TRAPPED BELOW A SUBSIDENCE INVERSION. THIS
IS ALSO SEEN ON THE AFOREMENTIONED SOUNDINGS. A SURFACE RIDGE OF
HIGH PRESSURE THAT STRETCHED FROM HUDSON BAY THROUGH SOUTHERN
WISCONSIN IS ALSO HELPING TO PROVIDE A COOL FLOW OF AIR...THUS NOT
ALLOWING THE STRATUS DECK TO DISSIPATE. TO THE WEST...MUCH WARMER
AIR WAS PRESENT UNDER THE BUILDING RIDGING OVER THE NORTHERN PLAINS.
850MB TEMPS CLIMB FROM -1C AT GRB TO 7C AT MPX...10C AT ABR AND 19C
AT UNR. THIS WARM AIR HAS BEEN SLOWLY PUSHING EAST AHEAD OF A LEE
TROUGH OVER THE WESTERN DAKOTAS...WITH 850MB PROFILER DATA SHOWING
SOUTHWEST WINDS OF 10-25 KT FROM THE PLAINS TO NEAR I-35 IN MN AND
IOWA. SO FAR ONLY HIGH BASED ALTOSTRATUS AND CIRRUS WERE PRESENT
WITH THE WARM ADVECTION.
TODAY AND TONIGHT...AS THE UPPER TROUGHING OFF THE COAST OF
CALIFORNIA PLOWS INTO THE WEST COAST...UPPER RIDGING LOOKS TO
FURTHER BUILD/STRENGTHEN DOWNSTREAM OVER THE PLAINS. AS A RESULT...
THE UPPER FLOW OVER THE FORECAST AREA STAYS NORTHWESTERLY THROUGH
TONIGHT. DESPITE THE NORTHWEST FLOW AT 500MB...LOWER LEVELS SUCH AS
850MB DEPICT A WARM ADVECTION PATTERN...WHICH ALLOWS THE CURRENT
SURFACE RIDGE TO MOVE OFF TO THE EAST. THE COMBINATION OF THE RIDGE
PUSHING EAST TODAY AND DAYTIME HEATING WILL ALLOW THE LOW CLOUDS TO
MIX/CLEAR OUT. SHOULD STILL SEE SOME HIGH BASED MID/HIGH CLOUD COVER
LIKE IS BEING OBSERVED OVER THE DAKOTAS NOW. SO OVERALL...A CLOUDY
BECOMING PARTLY SUNNY DAY. 925MB TEMPS CLIMB THROUGH THE DAY...
TOPPING OUT FROM 8C EAST TO 14C WEST BY 00Z. SOUNDINGS SUGGEST EASY
MIXING TO THIS LEVEL AND LIKELY UP TO 900MB...SUPPORTING HIGHS FROM
THE MID 50S EAST TO MID/UPPER 60S WEST. FOR TONIGHT...A WARM FRONT
OVER SOUTHWEST IOWA AT 00Z LOOKS LIKE IT WILL LIFT INTO NORTHEAST
IOWA BY 12Z. ISENTROPIC LIFT SEEN ON 300-305K SURFACES OVER THIS
FRONT COULD SUPPORT SOME CONVECTION SOUTH OF I-90. A SURGE OF
850MB DEWPOINTS OF 8-10C AND TEMPS AROUND 16C ACCOMPANY THE
ISENTROPIC LIFT...RESULTING IN ELEVATED CAPE VALUES OF 500 TO
PERHAPS AS HIGH AS 1000 J/KG IF THE 31.00Z NAM IS CORRECT. 1-6 KM
SHEAR VALUES OF 30-40 KT EXIST WHICH WOULD SUPPORT ORGANIZED
CONVECTION WITH LARGE HAIL BEING THE MAIN HAZARD. SINCE GOOD
CONSENSUS CONTINUES FOR THIS PRECIPITATION SOUTH OF I-90...RAISED
PRECIPITATION CHANCES UP ANOTHER 10 PERCENT. ONE THING TO WATCH
FOR IS THAT THE ECMWF REMAINS EVEN A LITTLE FARTHER SOUTH WITH THE
CONVECTION. WITH SCT-BKN MID/HIGH CLOUDS THROUGHOUT MUCH OF THE
NIGHT AND A GENERAL WARM ADVECTION PATTERN IN PLACE...ANTICIPATING
A MUCH WARMER NIGHT TONIGHT. FOLLOW A BLEND OF GUIDANCE FOR LOWS.
SUNDAY INTO SUNDAY NIGHT...THE WEST COAST TROUGH IS PROGGED TO PUSH
EAST IT NO THE ROCKIES...PERHAPS BEGINNING TO SPLIT INTO TWO PIECES
BY 12Z MONDAY AS IT RUNS INTO THE STRONGER RIDGING DOWNSTREAM. THIS
RIDGING SHOULD ENVELOP MUCH OF THE FORECAST AREA SUNDAY NIGHT.
ANTICIPATING THE SUBSIDENCE UNDER THIS UPPER RIDGE WILL BE ENOUGH TO
KEEP THE MAJORITY OF THE FORECAST AREA DRY DURING THIS PERIOD.
HOWEVER...THERE HAS BEEN A SIGNAL FOR A FRONTOGENESIS BAND OF
SHOWERS AND EMBEDDED THUNDERSTORMS TO DEVELOP SUNDAY NIGHT...FROM
NORTHERN MN INTO NORTHWEST WISCONSIN AND SOUTHEAST TO THE GREEN BAY
AREA. THIS IS MOST PREVALENT IN THE 31.00Z NAM...WHERE THE 31.00Z
GFS/UKMET/CANADIAN KEEP IT CONFINED MORE TO NORTHERN MN AND
NORTHWEST WISCONSIN. 31.00Z ECMWF IS COMPLETELY DRY. HAVE STAYED
TOWARDS THE DRIER SCENARIOS SEEING THE STRENGTH OF THE UPPER
RIDGE...BUT JUST IN CASE CONVECTION OCCURS IN NORTHWEST WISCONSIN
DID PLACE A 20 PERCENT CHANCE OVER TAYLOR COUNTY. OTHERWISE...
TEMPERATURES ARE THE MAIN CONCERN. THAT WARM FRONT LIFTING UP
TONIGHT LOOKS TO GET STUCK NEAR OR JUST SOUTH OF THE FORECAST
AREA...DUE TO THE NORTHWEST FLOW ALOFT AHEAD OF THE UPPER RIDGE
AXIS. STILL...925MB TEMPS CLIMB TO 14C EAST TO 20-22C WEST. THESE
READINGS SUGGEST A WIDE RANGE OF HIGHS...LIKELY FROM THE UPPER 60S
SAY IN MEDFORD TO NEAR WISCONSIN RAPIDS...TO LOW OR PERHAPS EVEN MID
80S FROM CHARLES CITY IA TO AUSTIN MN. WARM NIGHT LIKELY ON TAP
SUNDAY NIGHT GIVEN THE WARM START AND A PERSISTENT EAST TO SOUTHEAST
BREEZE.
MONDAY AND MONDAY NIGHT...VERY GOOD AGREEMENT EXISTS THAT THE
WESTERN UPPER TROUGH SPLITS WITH THE SOUTHERN PORTION CUTTING OFF
INTO AN UPPER LOW OVER NEW MEXICO. MEANWHILE...THE NORTHERN PORTION
ENDS UP TRACKING WELL TO OUR NORTH...MOVING INTO NORTHWEST ONTARIO
BY 12Z TUESDAY. THIS PUTS SOME QUESTION MARKS INTO FORCING FOR
PRECIPITATION. THE UPPER RIDGE THAT WAS OVER THE AREA AT 12Z MONDAY
WILL BREAK DOWN WITH THE APPROACH OF THE NORTHERN TROUGH FEATURE...
WHICH SHOULD HELP. ALSO...AT THE SURFACE...A TROUGH/COLD FRONT LOOKS
TO CROSS THE AREA TO PROVIDE SURFACE CONVERGENCE. HOWEVER...THE
TIMING OF THIS SURFACE FEATURE IS FAR FROM CERTAIN...WITH THE 31.00Z
ECMWF/CANADIAN/UKMET POSITION OVER WESTERN MINNESOTA COMPARED TO
CENTRAL/EASTERN WISCONSIN FROM THE 31.00Z GFS/NAM. THE LATTER
SOLUTIONS PRODUCE SOME SHOWER AND THUNDERSTORM ACTIVITY ON MONDAY
INTO MONDAY EVENING...WHICH MAKES SENSE GIVEN THE TIMING DURING PEAK
HEATING. MEANWHILE...THE ECMWF/CANADIAN/UKMET WAIT UNTIL MONDAY
NIGHT. LEANED A LITTLE MORE TOWARD THE ECMWF/CANADIAN/UKMET
GROUP...KEEPING CHANCES ONLY AT 20-30 FOR MONDAY AND 30-50 FOR
MONDAY NIGHT. IN ADDITION...TEMPERATURES FOR MONDAY ARE EXTREMELY
TRICKY DEPENDING ON THE FRONTAL TIMING. FOR NOW STAYED WITH A
CONSENSUS BLEND...BUT IF THE ECMWF IS RIGHT...MONDAY COULD LOOKS
JUST LIKE SUNDAY AND BE A FEW DEGREES WARMER. NEEDLESS TO SAY...A
LOT OF UNCERTAINTY.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
315 AM CDT SAT MAR 31 2012
QUIET WEATHER LOOKS TO DOMINATE THE ENTIRE LONG TERM PERIOD. A
CANADIAN HIGH PRESSURE RIDGE IS PROGGED BY THE 31.00Z
ECMWF/GFS/CANADIAN/UKMET TO BUILD INTO THE FORECAST AREA
TUESDAY...BEHIND MONDAY NIGHTS COLD FRONT...THEN ONLY DRIFT OFF TO
THE EAST THROUGH FRIDAY NIGHT. MEANWHILE...UPPER RIDGING LOOKS TO
BUILD ALOFT AHEAD OF DEEP TROUGHING DEVELOPING OVER THE WESTERN U.S.
THROUGH THE LONG TERM PERIOD. THIS SETUP FAVORS DRY CONDITIONS.
NOTE...THE 31.00Z GFS TRIES TO BRING THE CUT-OFF UPPER LOW IN NEW
MEXICO MONDAY NIGHT INTO IOWA BY 12Z THURSDAY...RESULTING IN SOME
SHOWERS OVER THE FORECAST AREA. THIS MODEL IS AN OUTLIER...EVEN
COMPARED TO ITS PREVIOUS RUN AND MOST OF ITS ENSEMBLE MEMBERS...AND
THEREFORE IGNORED AT THIS TIME. 850MB TEMPS WILL SLOWLY COOL...
DROPPING TO 2-4C FOR BOTH WEDNESDAY AND THURSDAY...BEFORE CLIMBING
BACK UP TO 4-6C ON FRIDAY AS THE SURFACE RIDGE MOVES EAST.
STILL...PLENTY OF SUN IS EXPECTED WHICH SHOULD HELP KEEP HIGHS ABOVE
NORMAL. CERTAINLY POSSIBLE TO SEE SOME FROST AT TIMES...ESPECIALLY
OVER CENTRAL WISCONSIN. IN ADDITION...MAY HAVE TO KEEP AN EYE ON
RELATIVE HUMIDITIES GIVEN WHAT LOOKS TO BE A BRIEF HUDSON BAY HIGH
SCENARIO...KNOWN TO MIX DEWPOINTS LOWER THAN FORECAST. HOWEVER...
WITH GREEN-UP WELL UNDERWAY...EVAPOTRANSPIRATION COULD KEEP
DEWPOINTS HIGHER MORE THAN WHAT WOULD NORMALLY OCCUR WITH A HUDSON
BAY HIGH.
&&
.AVIATION...THROUGH 06Z SUNDAY
1146 PM CDT FRI MAR 30 2012
MAIN CHALLENGE REMAINS ON CEILING HEIGHTS AND POTENTIAL CLEARING
TREND ON SATURDAY. WIDESPREAD MVFR CEILINGS HAVE BEEN PRESENT OVER
THE TAFS SITES THROUGHOUT THE EVENING. STRATUS WAS BEGINNING TO
REFORM WHERE SKIES HAD CLEARED ACROSS SOUTH CENTRAL MINNESOTA.
31.02Z RUC AND 31.00Z NAM BUFKIT SOUNDINGS SHOW LOW LEVEL MOISTURE
TRAPPED UNDER THE INVERSION THROUGH AT LEAST MIDDAY SATURDAY. WILL
LIKELY SEE CEILINGS CONTINUE TO DROP INTO THE IFR CATEGORY AT BOTH
TAF SITES BETWEEN 06Z-09Z...AND THEN BEGIN TO RAISE AFTER 15Z INTO
THE MVFR CATEGORY AND FINALLY SCATTERED OUT BETWEEN 17Z-19Z.
NEXT QUESTION IS THE POTENTIAL FOR CONVECTION SATURDAY NIGHT. LOW
LEVEL MOISTURE TRANSPORT NOSES NORTHWARD INTO IOWA...WITH BOTH THE
NAM AND GFS GENERATING CONVECTION OVER NORTHEAST IOWA BETWEEN 00Z-
06Z. AT THIS POINT IT LOOKS LIKE CONVECTION WOULD BE SOUTH OF THE
TAF SITES...BUT WILL HAVE TO WATCHED. WILL NOT MENTION ANYTHING AT
THIS TIME...WITH THE EXCEPTION OF SOME SCATTERED CUMULUS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
315 AM CDT SAT MAR 31 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1146 PM CDT FRI MAR 30 2012
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT
343 PM CDT FRI MAR 30 2012
AT 3 PM...THE COMBINATION OF EXTENSIVE CLOUD COVER AND EASTERLY
WINDS BRINGING COOLER AIR INTO THE REGION FROM MICHIGAN...
TEMPERATURES ACROSS WISCONSIN WERE HELD IN THE 35 TO 45 DEGREE
RANGE. MEANWHILE A BIT OF SUNSHINE ALLOWED TEMPERATURES TO
CLIMB INTO THE LOWER AND MID 50S.
THE MODELS ARE IN GENERAL AGREEMENT THAT THE LOW CLOUDS WILL
REMAIN TRAPPED UNDERNEATH A SUBSIDENCE INVERSION INTO SATURDAY
MORNING. THESE CLOUDS WILL KEEP TEMPERATURES FROM FALLING BELOW
FREEZING ACROSS WESTERN WISCONSIN TONIGHT. DUE TO THIS...REMOVED
THE MENTION OF FROST ACROSS NORTH-CENTRAL AND CENTRAL WISCONSIN
FOR TONIGHT.
ON SATURDAY AFTERNOON...THE NAM/WRF CONTINUES TO GENERATE A CLUSTER
OF SHOWERS AND THUNDERSTORMS ACROSS NORTHEAST IOWA AND SOUTHWEST
WISCONSIN. THIS PRECIPITATION IS DEVELOPING ON THE NOSE AN 850 MB
JET. THIS PRECIPITATION THEN SHIFTS SOUTH AND EAST OF AREA.
MEANWHILE THE REMAINDER OF THE MODELS CONTINUE TO KEEP THIS PERIOD
DRY. OVERLY...NOT THAT IMPRESSED THE MOISTURE TRANSPORT IN THE
NAM/WRF...SO TREATED IT AS AN OUTLIER AND WENT DRY.
ON SATURDAY NIGHT...THERE IS MORE OF A CONSISTENT SIGNAL IN THE
MODELS THAT THE LOW LEVEL JET WILL BRING SOME MODEST MOISTURE
TRANSPORT INTO NORTHEAST IOWA AND SOUTHWEST WISCONSIN. IN ADDITION...
A BACK DOOR COLD FRONT WILL BE PUSHING SOUTHWEST ACROSS THE AREA.
THIS FRONT WILL BE THE FOCUS FOR THE DEVELOPMENT OF AN AREA OF
PRECIPITATION ACROSS NORTHEAST IOWA AND SOUTHWEST WISCONSIN. WITH
0-3 KM MOST UNSTABLE CAPES CLIMBING UP TO 500 J/KG...THERE SHOULD
BE ENOUGH INSTABILITY FOR THE DEVELOPMENT OF A FEW THUNDERSTORMS.
WITH 1-6 KM BULK SHEAR RUNNING BETWEEN 35 AND 40 KNOTS...THERE MAY
BE ENOUGH SHEAR FOR A FEW THUNDERSTORMS TO PRODUCE HAIL.
ON SUNDAY...THERE CONTINUES TO BE MUCH UNCERTAINTY ON THE
TEMPERATURES ACROSS THE REGION. THIS IS DUE TO THE UNCERTAINTY
THAT EXISTS ON WHERE THE WARM FRONT WILL BE LOCATED. TO THE SOUTH
AND WEST OF THE FRONT...TEMPERATURES WILL CLIMB WELL INTO THE 70S.
MEANWHILE NORTH AND EAST OF THIS FRONT...TEMPERATURES WILL REMAIN
IN THE 60S AND 70S. DUE TO THE POTENTIAL FOR MAJOR TEMPERATURE BUSTS...
WENT VERY CONSERVATIVE ON THE TEMPERATURE FORECAST FOR THIS TIME PERIOD.
.LONG TERM...MONDAY THROUGH FRIDAY
343 PM CDT FRI MAR 30 2012
ON MONDAY...THE 700 MB TEMPERATURES IN THE GFS ARE RUNNING BETWEEN
4 AND 6C. MEANWHILE THE OTHER MODELS SUGGEST 700 MB TEMPERATURES
AROUND 8C. AS A RESULT...THE OTHER MODELS SUGGEST MORE CAPPING.
ANOTHER DIFFERENCE IN THE GFS IS THAT ITS WARM FRONT IS MUCH FURTHER
SOUTH THAN THE OTHER MODELS. THESE DIFFERENCES ARE THE MAIN REASONS
WHY IT CONTINUES TO GENERATE PRECIPITATION ACROSS THE REGION AND THE
OTHER MODELS SUGGEST THAT THE AREA WILL REMAIN DRY. SINCE EITHER
SCENARIO IS STILL POSSIBLE...JUST LOWERED THE PRECIPITATION
CHANCES BY 10 TO 20 PERCENT FOR NOW. IF THE CAP HAPPENS TO BREAK...
THERE IS A DECENT AMOUNT OF INSTABILITY /NAM 1500-3000 J/KG AND
GFS UP TO 1500 J/KG/. THIS WOULD RESULT IN SOME THUNDERSTORM
DEVELOPMENT. HOWEVER THE 0-6 KM SHEAR IS LESS THAN 30 KNOTS...
SO PROBABLY NOT ENOUGH TO ORGANIZE THE CONVECTION.
ON MONDAY NIGHT...ALL OF THE MODELS ARE IN GOOD AGREEMENT THAT A
COLD FRONT WILL MOVE EAST THROUGH THE REGION. WITH THE BEST UPPER
LEVEL SUPPORT BEING WELL TO THE NORTH AND SOUTH OF THE AREA...NOT
EXPECTING TOO MUCH PRECIPITATION FROM THIS FRONT. A MATTER OF
FACT...THE SOUTHERN SHORT WAVE /WHICH IS BEGINNING TO TRANSITION TO
A CUT OFF LOW/ IS INTERCEPTING THE RICHER MOISTURE FROM THE GULF
OF MEXICO. WITH CAPES STILL UP TO 1500 J/KG...THERE SHOULD BE
ENOUGH INSTABILITY FOR THUNDERSTORMS...BUT THE BEST 0-6 KM SHEAR
SLIDES OFF TO OUR NORTH IN RESPONSE TO THE NORTHERN SHORT WAVE
MOVING NORTHEAST AWAY FROM THE AREA.
FROM TUESDAY THROUGH FRIDAY...THE MODELS ARE IN GOOD AGREEMENT THAT
AN OMEGA BLOCK WILL DEVELOP ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY. FURTHER TO THE SOUTH...A CLOSED LOW WILL BE MOVING SLOWLY
THROUGH THE SOUTHERN PLAINS AND LOWER MISSISSIPPI RIVER VALLEY. THIS
HIGH WILL PROVIDE DRY WEATHER AND SLIGHTLY ABOVE NORMAL
TEMPERATURES DURING THIS TIME PERIOD.
&&
.AVIATION...THROUGH 06Z SUNDAY
1146 PM CDT FRI MAR 30 2012
MAIN CHALLENGE REMAINS ON CEILING HEIGHTS AND POTENTIAL CLEARING
TREND ON SATURDAY. WIDESPREAD MVFR CEILINGS HAVE BEEN PRESENT OVER
THE TAFS SITES THROUGHOUT THE EVENING. STRATUS WAS BEGINNING TO
REFORM WHERE SKIES HAD CLEARED ACROSS SOUTH CENTRAL MINNESOTA.
31.02Z RUC AND 31.00Z NAM BUFKIT SOUNDINGS SHOW LOW LEVEL MOISTURE
TRAPPED UNDER THE INVERSION THROUGH AT LEAST MIDDAY SATURDAY. WILL
LIKELY SEE CEILINGS CONTINUE TO DROP INTO THE IFR CATEGORY AT BOTH
TAF SITES BETWEEN 06Z-09Z...AND THEN BEGIN TO RAISE AFTER 15Z INTO
THE MVFR CATEGORY AND FINALLY SCATTERED OUT BETWEEN 17Z-19Z.
NEXT QUESTION IS THE POTENTIAL FOR CONVECTION SATURDAY NIGHT. LOW
LEVEL MOISTURE TRANSPORT NOSES NORTHWARD INTO IOWA...WITH BOTH THE
NAM AND GFS GENERATING CONVECTION OVER NORTHEAST IOWA BETWEEN 00Z-
06Z. AT THIS POINT IT LOOKS LIKE CONVECTION WOULD BE SOUTH OF THE
TAF SITES...BUT WILL HAVE TO WATCHED. WILL NOT MENTION ANYTHING AT
THIS TIME...WITH THE EXCEPTION OF SOME SCATTERED CUMULUS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
343 PM CDT FRI MAR 30 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...RABERDING
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1040 AM CDT SAT MAR 31 2012
.DISCUSSION...
ISSUED 1040 AM CDT SAT MAR 31 2012
LOW STRATUS DECK COVERED MUCH OF CENTRAL AND SOUTHEAST THIS
MORNING. THIS MOISTURE WAS TRAPPED BENEATH A PRETTY STOUT
SUBSIDENCE INVERSION PER 12Z KILX/KDVN SOUNDINGS. THE INVERSION IS
STRONGER THAN FORECAST BY THE MODELS...AND HAS RESULTED IN A
SLOWER CLEARING TRENDS THAN PREVIOUSLY ANTICIPATED. HOWEVER...
RECENT VISIBLE SATELLITE LOOPS SHOW THE STRATUS STARTING TO ERODE
FROM THE SOUTHWEST. THIS CLEARING TREND IS EXPECTED TO CONTINUE AS
DIURNAL HEATING INCREASES...AND THE CLEARING TREND WILL ALSO BE
AIDED BY SURFACE WINDS TRENDING TO THE SOUTHEAST IN THE WAKE OF
THE SURFACE RIDGE AXIS CURRENTLY OVER THE AREA.
HAVE UPDATED GRIDS FOR SLOWER CLEARING TRENDS...AS WELL AS A
RELATED SLOWER TEMPERATURE WARM UP. ALSO KNOCKED A DEGREE OR TWO
OFF MAX TEMPERATURES ALONG/NORTH OF THE I-74 CORRIDOR WHERE SKIES
WILL CLEAR THE LATEST AND PRESENT TEMPS ARE 20 DEGREES BELOW
FORECAST HIGHS.
BAK
&&
.AVIATION...
ISSUED 645 AM CDT SAT MAR 31 2012...FOR THE 12Z TAFS
IFR/MVFR STRATUS HAS OVERSPREAD ALL THE TERMINAL SITES FROM THE
NORTHEAST. COLD LOW LEVEL FLOW HAS PERSISTED FROM HIGH PRESSURE
CENTERED TO THE NORTHEAST OF IL...IN EASTERN ONTARIO. THE SURFACE RIDGE
AXIS EXTENDS INTO CENTRAL ILLINOIS...AND IT WILL SLIDE EAST OF IL
TODAY...SETTING UP A MORE SOUTHEAST TO SOUTH FLOW WHICH SHOULD
HELP PUSH THE CLOUDS BACK TO THE NORTH. MIXING OF DRY AIR FROM
ALOFT WILL ALSO AID IN DISSIPATING THE LOW STRATUS CLOUDS. WE
EXPECT SPI AND DEC TO CLEAR OUT SOONEST...WITH SPI AT 15Z AND DEC
- 16Z. PIA/BMI/CMI WILL CLEAR OUT TOWARD EARLY AFTERNOON...UNLESS
MIXING BECOMES DEEPER TO TAP INTO A DEEPER DRY LAYER.
AT THE VERY LEAST...THE IFR CONDITIONS AT PIA AND BMI WILL LIFT TO
MVFR BY 15Z DUE TO DAYTIME HEATING AND THE ONSET OF MIXING. VFR
CONDITIONS ARE EXPECTED AT ALL TERMINALS BY 19Z-20Z.
INCREASING SUNSHINE THIS AFTERNOON WILL ALSO BOOST
MIXING...HELPING WINDS TO INCREASE INTO THE 12-14KT RANGE...AS
THEY VEER FROM ENE TO SE. WINDS WILL BECOME SOUTHERLY LATE TONIGHT
AS A STORM SYSTEM PASSES BY TO THE NORTH OF THE TERMINALS. WINDS
MAY INCREASE ABOVE 10KT AGAIN LATE IN RESPONSE TO THAT SHORTWAVE.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 255 AM CDT SAT MAR 31 2012
THE COLD FRONT THAT PASSED THROUGH LAST EVENING WAS NEAR THE OHIO
RIVER EARLY THIS MORNING. NORTHEAST WINDS ARE BRINGING A STRATUS
DECK SOUTHEASTWARD...REACHING TAYLORVILLE AND MATTOON AT 3 AM.
SIGNIFICANT PUSH OF COOLER AIR HAS DROPPED TEMPERATURES INTO THE
40S UNDERNEATH THE CLOUDS.
INITIAL FORECAST CONCERNS INVOLVE TEMPERATURES TODAY WITH THE
EFFECTS OF ANY LINGERING CLOUD COVER...AS WELL AS MUCH WARMER
CONDITIONS FOR SUNDAY AND MONDAY. TIMING AND COVERAGE OF MIDWEEK
SHOWERS ARE ALSO AN ISSUE.
SHORT TERM...TODAY THROUGH MONDAY...
LATEST RUC AND HRRR MODELS SUGGESTING THAT THE CLOUD DECK SHOULD
TRACK A LITTLE FURTHER SOUTH IN THE NEXT FEW HOURS...BEFORE
BEGINNING TO ERODE. WITH THIS THINKING...HAVE TRENDED THE SKY
GRIDS TO BE MOSTLY SUNNY BY MIDDAY...EXCEPT PERHAPS OVER THE FAR
NORTH. SHOULD GET TEMPERATURES INTO THE 70S ACROSS THE
SOUTHWEST...WITH COOLER 60S NORTHEAST. A SLOWER THAN EXPECTED
CLOUD BREAKUP WOULD RESULT IN TEMPERATURES IN THAT AREA CLOSER TO
THE COOLER MET GUIDANCE...BUT HAVE GONE CLOSER TO THE WARMER MAV
MOS AT THE MOMENT.
LATEST MODEL SUITE SHOWING MCS DEVELOPMENT ACROSS EASTERN IOWA
OVERNIGHT...AS A FRONTAL BOUNDARY ESTABLISHES ITSELF FROM NORTHERN
IOWA TO LOWER MICHIGAN. LATEST ECMWF MODEL IS THE FURTHEST SOUTH
WITH THE TRACK...REACHING POTENTIALLY AS FAR SOUTH AS SPRINGFIELD
AND DECATUR BY SUNRISE. THE REMAINING MODELS HAVE THE MCS SKIMMING
THE NORTH/NORTHEAST BORDER. HAVE MAINTAINED THE RAIN CHANCES OVER
THE NORTHERN HALF OF THE CWA...PRIMARILY BETWEEN MIDNIGHT AND
SUNRISE...AND SCALED THEM BACK ACROSS THE SOUTH.
UPPER RIDGE PROGGED BY THE MODELS TO AMPLIFY OVER THE CENTRAL
UNITED STATES THIS WEEKEND...SHIFTING TO THE MISSISSIPPI VALLEY BY
EARLY MONDAY MORNING. PRETTY GOOD SLUG OF WARM AIR WILL SPREAD
OVER THE STATE...WITH 850 MB TEMPERATURES RISING TO NEAR 20C ON
MONDAY. HAVE CONTINUED WITH THE 80S FOR HIGHS FOR SUNDAY...BUT
WILL NEED TO MONITOR THE CIRRUS BLOWOFF FROM THE MCS WHICH MAY
HELP KEEP TEMPS FROM RISING QUITE AS MUCH. HOWEVER...HAVE BOOSTED
HIGHS ON MONDAY BY A FEW DEGREES FROM EARLIER FORECASTS...AS THAT
WARMER AIR AT 850 MB MIXES TOWARD THE SURFACE. MAY SEE SOME RECORD
HIGHS AGAIN...AS CURRENT VALUES ARE IN THE MID TO UPPER 80S.
MAV/MEX MOS GUIDANCE SUGGESTING SOME 90 DEGREE READINGS ARE
POSSIBLE ACROSS THE SOUTHWEST CWA.
LONG TERM...TUESDAY THROUGH FRIDAY...
UPPER LEVEL TROUGHING ACROSS THE DESERT SOUTHWEST LATE THIS
WEEKEND WILL CUT OFF INTO A CLOSED LOW...WHICH IS PROGGED TO DRIFT
INTO THE CENTRAL PLAINS BY MIDWEEK. EXTENDED RANGE MODELS STARTING
TO TREND NORTHWARD WITH THIS TRACK...WITH THE GFS THE FARTHEST
NORTH INTO SOUTHERN IOWA. CURRENTLY PREFER THE MORE SOUTHERN
SOLUTION SOUTH OF THE OHIO VALLEY. AN EXTENDED PERIOD OF RAIN IS
LIKELY OVER PORTIONS OF THE MID-MISSISSIPPI VALLEY...BUT DRY
EASTERLY WINDS ASSOCIATED WITH A HIGH OVER THE GREAT LAKES WILL
CAUSE SOME EROSION OF THE PRECIP ON THE NORTHEAST FLANK. THE
LATEST ECMWF SURGES THE PRECIPITATION MUCH FURTHER NORTH THAN ITS
EARLIER RUN AND COVERS MOST OF THE CWA...WHILE THE CANADIAN MODEL
IS MORE LIMITED TO THE SOUTHEAST. HAVE INTRODUCED SLIGHT CHANCE
POPS FOR NOW ACROSS THE SOUTHEAST CWA WEDNESDAY NIGHT AND
THURSDAY...AND THESE MAY NEED TO BE BOOSTED IN FUTURE PACKAGES AS
MODEL AGREEMENT BECOMES TIGHTER.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
941 AM CDT SAT MAR 31 2012
.DISCUSSION...
941 AM CDT
SOME CHANGES MADE TO THE GOING CLOUD AND TEMPERATURE TRENDS TO
SLOW THE CLEARING IN A FEW AREAS AND ACCORDINGLY STIFLE THE
TEMPERATURE RISE.
A BLANKET OF CLOUDS REMAIN OVER THE REGION THIS MORNING WITHIN
LOW-LEVEL RIDGING. RAOBS AND AMDAR MEASUREMENTS...AND SATELLITE
ESTIMATES...INDICATE THE CLOUD DEPTH BETWEEN 700 AND 1000 FT
THICK...WHICH IS CERTAINLY SHALLOW ENOUGH FOR THE FINAL DAY OF
MARCH THAT ONE WOULD THINK HOLES WILL BEGIN TO DEVELOP AND SPREAD
QUICKLY. EVEN SOME FURTHER SUBSIDENCE IS PREDICTED THE NEXT FEW
HOURS ABOVE THE CLOUD LAYER TO AID THAT. THE LATEST HRRR AND 31.12
NAM INDICATE SOME SCATTERING OVER LAKE MI INTO FAR NORTHEAST IL
AND NORTHWEST IN THROUGH THE NEXT FEW HOURS....WHICH MAKES DECENT
SENSE WITH DECREASING DEW POINTS WORKING IN FROM THAT DIRECTION.
ALSO A BREAK DOWN IN CLOUDS IS FAVORED IN RELATIVE HUMIDITY FIELDS
ACROSS THE SOUTH AND THE WEST.
THE ONE AREA THAT IS SHOWING SOMEWHAT OF A CONSISTENT SIGNAL TO BE
CLOUDED IN POTENTIALLY THROUGH MID TO LATE AFTERNOON IS THE
WINNEBAGO...BOONE... MCHENRY...DEKALB...AND KANE COUNTY AREAS.
OBVIOUSLY THAT IS A SPECIFIC AREA...BUT THE IDEA THAT TOWARD THE
WISCONSIN STATE LINE AWAY FROM THE DRY ADVECTION FROM THE EAST
WILL BE ONE OF THE FINAL AREAS TO CLEAR SEEMS REASONABLE. WITH
ONLY 2 TO 4 DEGREES OR SO MORE OF WARMING THROUGH NOON UNDER
OVERCAST SKY...WENT AHEAD AND CUT THEIR HIGH TEMPERATURE BY
SEVERAL DEGREES...AND TOOK 1 TO 2 DEGREES OFF ELSEWHERE. WITH THE
EASTERLY FLOW OFF THE LAKE...BORDERING LAKE COUNTIES OF NORTHEAST
IL ALSO SHOULD NOT CLIMB TOO RAPIDLY THIS AFTERNOON...WITH HIGHS
AT OR JUST A TAD ABOVE NORMAL. STILL LOWER TO MID 60S EXPECTED
ACROSS THE FAR SOUTH AND WEST.
MTF
&&
.PREV DISCUSSION...
257 AM CDT
TODAY AND TONIGHT...RIDGE AXIS IN PLACE WITH EXPANSIVE AREA OF
STRATUS TRAPPED UNDER STRONG INVERSION EARLY THIS MORNING. EXPECT
CLOUD COVER TO ERODE BY LATE MORNING OR EARLY AFTERNOON UNDER
ANTICYCLONIC FLOW AND SUBSIDENCE. TEMPERATURES WILL THEN WARM INTO
THE LOW TO MID 60S AWAY FROM THE LAKE FRONT. NORTHEASTERLY FLOW OFF
THE LAKE WILL KEEP TEMPERATURES IN THE LOW TO MID 50S CLOSER TO THE
LAKEFRONT TODAY. THIS AFTERNOON...MOISTURE POOLING IS EXPECTED
ACROSS MISSOURI INTO CENTRAL IOWA WHERE DEW POINTS ARE EXPECTED TO
RISE INTO THE LOW 60S AS WARM FRONT LIFTS BACK NORTH. BY
TONIGHT...ISENTROPIC ASCENT WILL INCREASE WITH SHOWERS AND
THUNDERSTORMS DEVELOPING ALONG THE MOISTURE AXIS OVER PORTIONS OF
IOWA AND PUSHING EAST ON THE NOSE OF 40KT LOW LEVEL JET INTO
NORTHERN ILLINOIS LATE TONIGHT. SURFACE WINDS WILL VEER TO THE
SOUTHEAST WITH WARM ADVECTION OVERNIGHT HELPING TO PROP UP
TEMPERATURES...WHICH ARE EXPECTED TO FALL INTO THE UPPER 40S TO LOW
50S BY LATE EVENING THE HOLD STEADY OR SLOWLY RISE OVERNIGHT.
SUNDAY...WARM FRONT DOES NOT ADVANCE MUCH DURING THE DAY SUNDAY WITH
A NORTHERN STREAM SYSTEM DROPPING SOUTHEAST ACROSS QUEBEC AND
TURNING FLOW BACK TO THE NORTHEAST FOR AT LEAST NORTHERN PORTIONS OF
THE FORECAST AREA. APPEARS THAT WITH THE FRONTAL BOUNDARY LINGERING
THROUGH THE DAY SUNDAY THAT WE WILL SET UP A STRONG TEMP GRADIENT
ACROSS THE CWA. ECMWF HAS COME MORE IN LINE WITH THIS SOLUTION WHICH
GFS HAS BEEN ADVERTISING THE PAST COUPLE DAYS. DROPPED TEMPERATURES
SEVERAL DEGREES ALONG THE LAKE SHORE AND WENT WITH NON-DIURNAL
TREND...SHOWING TEMPERATURES PEAKING EARLY IN THE DAY THEN DROPPING
AS LAKE AIR SPREADS INLAND WITH THE HELP OF SYNOPTICALLY NORTHEAST
FLOW. LINGERING SHOWERS AND CLOUD COVER IN THE MORNING ADD
ADDITIONAL UNCERTAINTY TO TEMPERATURE FORECAST...PARTICULARLY IN THE
WARMER AIR ACROSS EAST CENTRAL ILLINOIS.
MONDAY...GUIDANCE STILL A BIT MIXED ON HOW FAR NORTH THE WARM FRONT
WILL LIFT WITH GFS A SLOW/SOUTHERN OUTLIER AND PLACING PRECIP ALONG
THE WARM FRONT ACROSS NORTHERN ILLINOIS. OPTED TO KEEP FORECAST DRY
PER NAM/GEM/ECMWF SOLUTIONS WITH DRY AIR IN PLACE...DEEP MIXING
LAYERS AND VERY WARM TEMPERATURES. BUMPED UP TEMPS...ESPECIALLY
ACROSS THE SOUTH. BIAS CORRECTED NAM/ECMWF SHOW TEMPS SOARING INTO
THE 90S SOUTH OF THE I-80 CORRIDOR. SREF PLUMES SUPPORT MID 80S
ACROSS THE SOUTHERN PORTIONS OF THE CWA WITH STRONG CLUSTERING IN
THAT RANGE BUT A FEW SIGNIFICANT COLD OUTLIERS PULLING THE MEAN
INTO THE LOW 80S. MODEL CONSENSUS BLEND ALSO SUPPORTS MID 80S
ACROSS THE SOUTH. LAKE BREEZE IS POSSIBLE WITH MARGINAL WINDS
SPEEDS ALOFT SO MAY SEE TEMPERATURES COOL ALONG THE LAKE FRONT
THAT AFTERNOON.
TUESDAY THROUGH FRIDAY...A COLD FRONT WILL SWEEP ACROSS THE REGION
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS
WHILE USHERING IN MORE SEASONABLE TEMPERATURES FOR THE REMAINDER OF
THE WEEK. HIGH PRESSURE BUILDS ACROSS THE GREAT LAKES REGION
WEDNESDAY AND LINGERS THROUGH THE END OF THE WEEK. DRY CONDITIONS
SHOULD PERSIST WITH PLENTY OF SUNSHINE. BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* CIGS AROUND 010 EXPECTED TO SLOWLY RISE THROUGH THE
MORNING...THEN SCATTER MIDDAY OR EARLY AFTERNOON.
* EAST TO NORTHEAST WIND DIRECTION THROUGH THE MORNING WITH A
TREND TOWARD A MORE EAST-SOUTHEAST DIRECTION THIS AFTERNOON.
* CHANCE FOR SHRA/TSRA TO MOVE ACROSS LATE TONIGHT/EARLY SUNDAY
MORNING.
PAW
//DISCUSSION...UPDATED 12Z...
STRATUS REMAINS THE MAIN CONCERN THIS MORNING. MIX OF IFR/LOW MVFR
CIGS ACROSS THE TERMINALS AT ISSUANCE TIME. MAY STILL SEE A
SLIGHT LOWERING OVER THE NEXT 1-2 HOURS BUT EXPECT A SLOW UPWARD
TREND FROM THAT POINT ONWARD THROUGH THE MORNING. SCATTERING IS
EXPECTED TO OCCUR BY AROUND MIDDAY OR EARLY AFTERNOON BUT THE
SPECIFIC TIMING DETAILS MAY NEED SOME TWEAKING BUT HAVE GOOD
CONFIDENCE IN THE TREND. ONCE CLOUDS DO SCATTER VFR IS EXPECTED TO
PREVAIL INTO THE OVERNIGHT. WINDS WILL GENERALLY BE EAST TO
NORTHEAST WITH A TENDENCY TOWARD EAST-SOUTHEAST THIS
AFTERNOON...THOUGH GYY MAY SEE A CONTINUED NORTHEAST DIRECTION
UNTIL EARLY EVENING BEING CLOSE TO LAKE MICHIGAN.
NEXT CONCERN IS POTENTIAL FOR A BAND OF SHRA/TSRA TO MOVE ACROSS
THE TERMINALS LATE TONIGHT/EARLY SUNDAY MORNING. HAVE INCLUDED A
PROB30 MENTION EARLY SUNDAY. AT THIS POINT...BASED ON ATMOSPHERIC
SET UP...IMPACT DURATION WOULD BE ON THE ORDER OF A FEW HOURS BUT
THE TIME OF OCCURRENCE MAY NEED ADJUSTMENT.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM CONFIDENCE IN CIG TREND AND DETAILS.
* HIGH CONFIDENCE IN WIND TREND.
* MEDIUM CONFIDENCE IN SHRA/TSRA OCCURRING LATE TONIGHT/EARLY SUNDAY
MORNING. LOW CONFIDENCE IN TIMING.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...VFR WITH CHANCE TSRA MONDAY NIGHT.
TUESDAY...VFR WITH CHANCE SHRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
MDB
&&
.MARINE...
257 AM CDT
HIGH PRESSURE SPREAD FROM HUDSON BAY SOUTH AND SOUTHWEST ACROSS LAKE
MICHIGAN CONTINUES TO PROVIDE NORTHEAST TO SOUTHEAST WINDS ACROSS
THE LAKE EARLY THIS MORNING. WINDS WILL TURN SOUTHERLY THIS
AFTERNOON AS THE RIDGE AXIS SHIFTS EASTWARD AND OUT OF THE AREA. LOW
PRESSURE ACROSS THE CANADIAN PRAIRIES WILL WEAKEN AS IT MOVES EAST
BUT THE PRESSURE GRADIENT BETWEEN THE RIDGE AND THE TROUGH WILL
BRING AN INCREASE IN SOUTHERLY WINDS TO NORTHERN SECTIONS OF THE
LAKE THIS EVENING. THE WEAKENED LOW WILL PASS TO THE NORTHEAST OF
LAKE MICHIGAN SUNDAY MORNING SHIFTING WINDS TO THE NORTHEAST ONCE
AGAIN DURING THE DAY SUNDAY. A RIDGE AXIS WILL THEN ARRIVE FROM THE
NORTH SUNDAY EVENING BRINGING WINDS MORE TO THE SOUTHEAST BUT
ANOTHER LOW WILL PASS TO THE SOUTH OF THE LAKE TUESDAY MORNING
BRINGING A RETURN OF NORTHERLY WINDS. HIGH PRESSURE IS EXPECTED TO
RETURN LATER TUESDAY AND REMAIN IN PLACE THROUGH THE END OF THE
WEEK.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
645 AM CDT SAT MAR 31 2012
.DISCUSSION...
ISSUED 255 AM CDT SAT MAR 31 2012
THE COLD FRONT THAT PASSED THROUGH LAST EVENING WAS NEAR THE OHIO
RIVER EARLY THIS MORNING. NORTHEAST WINDS ARE BRINGING A STRATUS
DECK SOUTHEASTWARD...REACHING TAYLORVILLE AND MATTOON AT 3 AM.
SIGNIFICANT PUSH OF COOLER AIR HAS DROPPED TEMPERATURES INTO THE
40S UNDERNEATH THE CLOUDS.
INITIAL FORECAST CONCERNS INVOLVE TEMPERATURES TODAY WITH THE
EFFECTS OF ANY LINGERING CLOUD COVER...AS WELL AS MUCH WARMER
CONDITIONS FOR SUNDAY AND MONDAY. TIMING AND COVERAGE OF MIDWEEK
SHOWERS ARE ALSO AN ISSUE.
SHORT TERM...TODAY THROUGH MONDAY...
LATEST RUC AND HRRR MODELS SUGGESTING THAT THE CLOUD DECK SHOULD
TRACK A LITTLE FURTHER SOUTH IN THE NEXT FEW HOURS...BEFORE
BEGINNING TO ERODE. WITH THIS THINKING...HAVE TRENDED THE SKY
GRIDS TO BE MOSTLY SUNNY BY MIDDAY...EXCEPT PERHAPS OVER THE FAR
NORTH. SHOULD GET TEMPERATURES INTO THE 70S ACROSS THE
SOUTHWEST...WITH COOLER 60S NORTHEAST. A SLOWER THAN EXPECTED
CLOUD BREAKUP WOULD RESULT IN TEMPERATURES IN THAT AREA CLOSER TO
THE COOLER MET GUIDANCE...BUT HAVE GONE CLOSER TO THE WARMER MAV
MOS AT THE MOMENT.
LATEST MODEL SUITE SHOWING MCS DEVELOPMENT ACROSS EASTERN IOWA
OVERNIGHT...AS A FRONTAL BOUNDARY ESTABLISHES ITSELF FROM NORTHERN
IOWA TO LOWER MICHIGAN. LATEST ECMWF MODEL IS THE FURTHEST SOUTH
WITH THE TRACK...REACHING POTENTIALLY AS FAR SOUTH AS SPRINGFIELD
AND DECATUR BY SUNRISE. THE REMAINING MODELS HAVE THE MCS SKIMMING
THE NORTH/NORTHEAST BORDER. HAVE MAINTAINED THE RAIN CHANCES OVER
THE NORTHERN HALF OF THE CWA...PRIMARILY BETWEEN MIDNIGHT AND
SUNRISE...AND SCALED THEM BACK ACROSS THE SOUTH.
UPPER RIDGE PROGGED BY THE MODELS TO AMPLIFY OVER THE CENTRAL
UNITED STATES THIS WEEKEND...SHIFTING TO THE MISSISSIPPI VALLEY BY
EARLY MONDAY MORNING. PRETTY GOOD SLUG OF WARM AIR WILL SPREAD
OVER THE STATE...WITH 850 MB TEMPERATURES RISING TO NEAR 20C ON
MONDAY. HAVE CONTINUED WITH THE 80S FOR HIGHS FOR SUNDAY...BUT
WILL NEED TO MONITOR THE CIRRUS BLOWOFF FROM THE MCS WHICH MAY
HELP KEEP TEMPS FROM RISING QUITE AS MUCH. HOWEVER...HAVE BOOSTED
HIGHS ON MONDAY BY A FEW DEGREES FROM EARLIER FORECASTS...AS THAT
WARMER AIR AT 850 MB MIXES TOWARD THE SURFACE. MAY SEE SOME RECORD
HIGHS AGAIN...AS CURRENT VALUES ARE IN THE MID TO UPPER 80S.
MAV/MEX MOS GUIDANCE SUGGESTING SOME 90 DEGREE READINGS ARE
POSSIBLE ACROSS THE SOUTHWEST CWA.
LONG TERM...TUESDAY THROUGH FRIDAY...
UPPER LEVEL TROUGHING ACROSS THE DESERT SOUTHWEST LATE THIS
WEEKEND WILL CUT OFF INTO A CLOSED LOW...WHICH IS PROGGED TO DRIFT
INTO THE CENTRAL PLAINS BY MIDWEEK. EXTENDED RANGE MODELS STARTING
TO TREND NORTHWARD WITH THIS TRACK...WITH THE GFS THE FARTHEST
NORTH INTO SOUTHERN IOWA. CURRENTLY PREFER THE MORE SOUTHERN
SOLUTION SOUTH OF THE OHIO VALLEY. AN EXTENDED PERIOD OF RAIN IS
LIKELY OVER PORTIONS OF THE MID-MISSISSIPPI VALLEY...BUT DRY
EASTERLY WINDS ASSOCIATED WITH A HIGH OVER THE GREAT LAKES WILL
CAUSE SOME EROSION OF THE PRECIP ON THE NORTHEAST FLANK. THE
LATEST ECMWF SURGES THE PRECIPITATION MUCH FURTHER NORTH THAN ITS
EARLIER RUN AND COVERS MOST OF THE CWA...WHILE THE CANADIAN MODEL
IS MORE LIMITED TO THE SOUTHEAST. HAVE INTRODUCED SLIGHT CHANCE
POPS FOR NOW ACROSS THE SOUTHEAST CWA WEDNESDAY NIGHT AND
THURSDAY...AND THESE MAY NEED TO BE BOOSTED IN FUTURE PACKAGES AS
MODEL AGREEMENT BECOMES TIGHTER.
GEELHART
&&
.AVIATION...
ISSUED 645 AM CDT SAT MAR 31 2012...FOR THE 12Z TAFS
IFR/MVFR STRATUS HAS OVERSPREAD ALL THE TERMINAL SITES FROM THE
NORTHEAST. COLD LOW LEVEL FLOW HAS PERSISTED FROM HIGH PRESSURE
CENTERED TO THE NORTHEAST OF IL...IN EASTERN ONTARIO. THE SURFACE RIDGE
AXIS EXTENDS INTO CENTRAL ILLINOIS...AND IT WILL SLIDE EAST OF IL
TODAY...SETTING UP A MORE SOUTHEAST TO SOUTH FLOW WHICH SHOULD
HELP PUSH THE CLOUDS BACK TO THE NORTH. MIXING OF DRY AIR FROM
ALOFT WILL ALSO AID IN DISSIPATING THE LOW STRATUS CLOUDS. WE
EXPECT SPI AND DEC TO CLEAR OUT SOONEST...WITH SPI AT 15Z AND DEC
- 16Z. PIA/BMI/CMI WILL CLEAR OUT TOWARD EARLY AFTERNOON...UNLESS
MIXING BECOMES DEEPER TO TAP INTO A DEEPER DRY LAYER.
AT THE VERY LEAST...THE IFR CONDITIONS AT PIA AND BMI WILL LIFT TO
MVFR BY 15Z DUE TO DAYTIME HEATING AND THE ONSET OF MIXING. VFR
CONDITIONS ARE EXPECTED AT ALL TERMINALS BY 19Z-20Z.
INCREASING SUNSHINE THIS AFTERNOON WILL ALSO BOOST
MIXING...HELPING WINDS TO INCREASE INTO THE 12-14KT RANGE...AS
THEY VEER FROM ENE TO SE. WINDS WILL BECOME SOUTHERLY LATE TONIGHT
AS A STORM SYSTEM PASSES BY TO THE NORTH OF THE TERMINALS. WINDS
MAY INCREASE ABOVE 10KT AGAIN LATE IN RESPONSE TO THAT SHORTWAVE.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
940 AM CDT SAT MAR 31 2012
.UPDATE...
ISSUED AT 939 AM CDT SAT MAR 31 2012
A VERY WEAK PRESSURE GRADIENT WILL CONTINUE ACROSS WESTERN KANSAS
THROUGH THE MORNING HOURS. PRESSURES WILL FALL IN THE LEE OF THE
ROCKIES THIS AFTERNOON AS THE UPPER LEVEL TROUGH MOVING THROUGH
MANITOBA CONTINUES MOVING NORTHEAST AND THE STRONG UPPER LEVEL
TROUGH NEAR 130W REACHES THE WEST COAST. LOW LEVEL FLOW WILL
INCREASE FROM THE SOUTH AS THE ATMOSPHERE RESPONDS TO THE LEE
TROUGHING. TEMPERATURES THIS AFTERNOON MAY NOT BE QUITE AS WARM AS
ANTICIPATED DUE TO ANOMALOUSLY STRONG EVAPOTRANSPIRATION FROM
EARLY PLANT GROWTH AFTER THE HEAVY RAINFALL LAST WEEK. MINOR
DOWNWARD ADJUSTMENTS WERE MADE WHERE THE HEAVIEST RAIN FELL.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 300 AM CDT SAT MAR 31 2012
.SYNOPSIS...
ISSUED AT 300 AM CDT SAT MAR 31 2012
THE 00Z 300 HPA SYNOPTIC MAP SHOWS A STRONG 140 KT JET TRAVERSING ACROSS
THE PACIFIC NORTHWEST. ACROSS THE PLAINS, 45 TO 65 KT NORTHWESTERLY
FLOW WAS OBSERVED IN THE WAKE OF A DEPARTING TROUGH AXIS LOCATED ACROSS
THE EASTERN PLAINS/MIDWEST. THE 500 HPA MAP SHOWED THAT VERY COLD AIR
OF -38 DEG C WAS OBSERVED ACROSS VANCOUVER ISLAND. IN THE LOWER LEVELS
(700 AND 850 HPA), A DRY AIRMASS WAS OVER THE PLAINS, PARTICULARLY ACROSS
THE NORTHERN PLAINS. SURFACE ANALYSIS FROM HPC SHOWED A LOW PRESSURE
SYSTEM WITH ASSOCIATED COLD AND WARM FRONTS MOVING ACROSS THE CANADIAN
PRAIRIES. HIGH PRESSURE WAS OVER THE CENTRAL AND SOUTHERN PLAINS. DEWPOINTS
CONTINUED TO BE IN THE MODERATE LEVELS (FOR END OF MARCH) WITH LOWER
TO MID 50S DEG F DEWPOINTS ACROSS SW AND SC KANSAS.
THIS MORNING:
THE MAIN FORECAST CONCERN FOR THIS MORNING IN TERMS OF SENSIBLE WEATHER
IS IF FOG WILL DEVELOP OR NOT. THE 01Z AND 02Z HRRR RUNS WERE VERY AGGRESSIVE
IN DEVELOPING DENSE FOG ACROSS THE SW/W KANSAS. THE 04Z HRRR RUN HAS
BACKED OFF ON THIS WITH A SMALLER AREA OF DENSE FOG MAINLY ACROSS HAMILTON
COUNTY. WHAT IS INTERESTING IS THAT EVEN THOUGH THE MODEL DEVELOPS THE
FOG, THE MODELS ALSO HAS DOWNSLOPE SSW AS THE SFC. THIS IS NOT CONDUCIVE
FOR DENSE FOG FORMATION ACROSS MY COUNTY WARNING AREA. VSREF ALSO SHOWED
SOME HIGHER PROBABILITIES FOR LOWER VIS ACROSS THE AREA. OTHER MODEL
GUIDANCE IS LESS SUGGESTIVE FOR FOG FORMATION. DESPITE THIS, OBSERVATIONS
ACROSS OKLAHOMA SHOW SOME PATCHY FOG DEVELOP THIS MORNING SO I HAVE
DECIDED TO MEET THE MODELS IN BETWEEN AND INSERT PATCHY FOG ACROSS MY
WESTERN COUNTIES. DEWPOINTS ARE CURRENTLY IN THE 50S DEG F WITH UPSLOPE
SE/S WINDS SO THE POTENTIAL CANNOT BE COMPLETELY DISMISSED ATTM.
TODAY:
500 HPA FLOW WILL BECOME MORE MORE WESTERLY THROUGH TODAY, WHICH WILL
STRENGTHEN LEE TROUGHING. AS A RESULT, A WARM AIR ADVECTION PATTERN
WILL BE IN PLACE TODAY WITH TEMPERATURES WARMING WELL ABOVE NORMAL.
MID 80S DEG F ARE EXPECTED FOR HIGHS TODAY, WHICH IS ABOUT 20 DEGREES
ABOVE NORMAL. THIS WARM MARCH WE HAVE BEEN EXPERIENCING WILL END ON
A VERY WARM NOTE FOR THE LAST DAY IN THE MONTH. TODAY WILL BE PRECIPITATION
FREE AS A FAIRLY FLAT UPPER LEVEL RIDGE PREVAILS ACROSS KANSAS. I HAVE
GONE WITH SLIGHTLY COOLER TEMPERATURES TODAY (MID 80S DEG F VERSUS UPPER
80S DEG F) AS RECENT VERIFICATION PER BOI VERIFY SHOWS THAT MODELS ARE
SUFFERING A BIT OF WARM BIAS. SOUTHERLY WINDS OF 15 TO 20 KT ARE EXPECTED
THIS AFTERNOON AS MIXING INCREASES TO ABOUT 750 HPA AND SOME STRONGER
WINDS MIX DOWN.
TONIGHT:
THE LEE SURFACE TROUGH AXIS WILL MOVE SLIGHTLY EASTWARD TONIGHT AND
FRAGMENT TOWARDS SUNDAY MORNING. THIS WILL KEEP SOUTHERLY WINDS IN THE
FORECAST OVERNIGHT. DEWPOINTS IN THE 30S DEG F WEST TO 50S DEG F EAST
WILL KEEP OVERNIGHT LOWS ON THE MILD SIDE, PARTICULARLY ACROSS SOUTH
CENTRAL KANSAS. HAVE AROUND 60 DEG F TOWARDS KP28 (MEDICINE LODGE, KS)
AND COOLER MID 40S NEAR K3K3 (SYRACUSE, KS).
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 322 AM CDT SAT MAR 31 2012
MODELS REMAINING VERY CONSISTENT WITH PREVIOUS RUNS AND KEEP
SUNDAY SUNNY AND WARM . 850MB 00Z MONDAY TEMPERATURES STILL
SUPPORT HIGHS AROUND 90 DEGREES FOR MUCH OF SOUTHWEST KANSAS.
THESE HIGHS FOR THE FIRST OF APRIL COULD EASILY SET NEW RECORD
HIGHS IN A FEW LOCATIONS. A FEW RECORDS FOR APRIL FIRST ARE....88
DEGREES AT DODGE CITY, 87 AT GARDEN CITY AND 93 DEGREES AT
MEDICINE LODGE.
IN ADDITION TO THIS UNSEASONABLY WARM TEMPERATURES...LOW DEW
POINTS WILL BE SPREADING INTO PORTIONS OF WESTERN KANSAS BEHIND A
DRYLINE. THIS WILL RESULT IN AFTERNOON RELATIVE HUMIDITIES
BOTTOMING OUT IN THE 10 TO 15 PERCENT RANGE IN SEVERAL LOCATIONS.
GIVEN THESE LOW RELATIVE HUMIDITIES ALONG WITH GUSTY SOUTHWEST
WINDS DEVELOPING DURING THE AFTERNOON HAVE DECIDED TO CONTINUE THE
FIRE WEATHER WATCH ACROSS MUCH OF WESTERN KANSAS.
FOR EARLY NEXT WEEK...OUR NEXT UPPER LEVEL STORM SYSTEM IS STILL
FORECAST BY THE GFS, ECMWF, AND CANADIAN TO CROSS THE FOUR CORNERS
REGION SUNDAY NIGHT. BY MONDAY THIS SYSTEM WILL BEGIN TO DEEPEN
ACROSS NEW MEXICO WHERE IT WILL MOVE VERY LITTLE THROUGH TUESDAY.
AHEAD OF THIS SYSTEM A SOUTHEAST FLOW WILL DRAW MORE HUMID AIR
NORTHWARD TOWARDS SOUTHWEST KANSAS ON MONDAY. IN ADDITION 850MB
WARM AIR ADVECTION AND 850-700 FRONTOGENESIS WILL BE ON THE
INCREASE LATE IN THE DAY ALONG AND JUST BEHIND A COLD FRONT WHICH
WILL BE CROSSING SOUTHERN KANSAS/NORTHERN OKLAHOMA. GIVEN THIS
IMPROVING LIFT/MOISTURE AHEAD OF THE DEEPENING NEW MEXICO LOW WILL
BEGIN INCREASING CLOUD COVER AND PRECIPITATION CHANCES EARLY
MONDAY NIGHT. WINDS BEHIND THIS COLD FRONT MAY ALSO BE AN ISSUE
LATE MONDAY AND EARLY MONDAY NIGHT AS A TIGHT SURFACE PRESSURE
GRADIENT IS EXPECTED TO DEVELOP ACROSS PORTIONS OF SOUTHWEST
KANSAS IN RESPONSE TO AN AREA OF LOW PRESSURE DEEPENING ALONG THIS
FRONTAL BOUNDARY NEAR THE OKLAHOMA PANHANDLE.
TUESDAY THROUGH EARLY WEDNESDAY STILL APPEARS SOMEWHAT UNCLEAR
GIVEN THE DISAGREEMENT ON TRACK OF THIS UPPER LOW AS IT MOVES EAST
INTO THE PANHANDLE OF TEXAS. SINCE MODELS DO NOT HANDLE THESE
SYSTEM WELL, ESPECIALLY BEYOND 72 HOURS WILL FOLLOW THE GENERAL
TREND OF THE ALLBLEND THROUGH MID WEEK. HAVE THEREFORE INCREASED
PRECIPITATION CHANCES ACROSS SOUTHWEST KANSAS AND GIVEN THE CLOUDS
AND PRECIPITATION EXPECTED HAVE ALSO LOWERED TEMPERATURES TUESDAY
AFTERNOON.
BY LATE WEDNESDAY THIS UPPER LOW MOVE EAST ACROSS THE PLAINS. AS
THIS SYSTEM MOVES EAST OF WESTERN KANSAS THE SKIES WILL CLEAR AS
AN UPPER LEVEL SHORTWAVE RIDGE STARTS TO BUILD INTO THE ROCKIES
FROM THE WEST. AS THE WESTERLY DOWNSLOPE FLOW IMPROVES LATE WEEK
TEMPERATURES WILL REBOUND OUT OF 60S AND BACK INTO THE
70S...POSSIBLY A FEW 80S BY LATE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 617 AM CDT SAT MAR 31 2012
VFR CIGS ARE EXPECTED THROUGH THE TAF PERIOD. A TROUGH OF LOW
PRESSURE AT THE SURFACE NEAR THE COLORADO BORDER WILL DEEPEN TODAY
WHICH WILL RESULT IN INCREASING SOUTH WINDS ACROSS WESTERN KANSAS.
WIND SPEEDS OF AROUND 15KTS CAN BE EXPECTED AFTER 18Z.
&&
.FIRE WEATHER...
ISSUED AT 300 AM CDT SAT MAR 31 2012
MARGINAL FIRE WEATHER CONDITIONS ARE EXPECTED SATURDAY AFTERNOON, AS
THE RELATIVE HUMIDITIES WILL NOT MEET RH CRITERIA. HAVE ADDRESSED THIS
CONCERN IN FWF. NEXT CONCERN IS CRITICAL FIRE WEATHER CONDITIONS EXPECTED
SUNDAY AFTERNOON. TEMPERATURES WILL BE VERY WARM AND WINDS WILL BE STRONGER
AS LEE CYCLOGENESIS STRENGTHENS ACROSS EASTERN COLORADO AND THE RELATED
PRESSURE GRADIENT INCREASES ACROSS THE REGION. THE FUEL STATUS PAGE
SHOWS THAT STEVENS AND MORTON COUNTY ARE A NO GO AS FUELS ARE NOT AT
THE APPROPRIATE LEVELS (NOTHING TO BURN?). THIS MAY HAVE TO BE ADDRESSED
BEFORE THE RFW IS ISSUED. OTHERWISE, AFTER COLLABORATION, IT WAS DECIDED
TO CONTINUE THE FIRE WEATHER WATCH FOR FAR WESTERN KANSAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 85 56 90 53 / 0 0 0 10
GCK 86 52 90 50 / 0 0 0 10
EHA 85 51 90 50 / 0 0 0 10
LBL 86 53 92 49 / 0 0 0 10
HYS 86 58 88 53 / 0 0 0 10
P28 84 60 88 58 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR KSZ061-062-074-075-084-085.
&&
$$
UPDATE...RUTHI
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
618 AM CDT SAT MAR 31 2012
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 300 AM CDT SAT MAR 31 2012
.SYNOPSIS...
ISSUED AT 300 AM CDT SAT MAR 31 2012
THE 00Z 300 HPA SYNOPTIC MAP SHOWS A STRONG 140 KT JET TRAVERSING ACROSS
THE PACIFIC NORTHWEST. ACROSS THE PLAINS, 45 TO 65 KT NORTHWESTERLY
FLOW WAS OBSERVED IN THE WAKE OF A DEPARTING TROUGH AXIS LOCATED ACROSS
THE EASTERN PLAINS/MIDWEST. THE 500 HPA MAP SHOWED THAT VERY COLD AIR
OF -38 DEG C WAS OBSERVED ACROSS VANCOUVER ISLAND. IN THE LOWER LEVELS
(700 AND 850 HPA), A DRY AIRMASS WAS OVER THE PLAINS, PARTICULARLY ACROSS
THE NORTHERN PLAINS. SURFACE ANALYSIS FROM HPC SHOWED A LOW PRESSURE
SYSTEM WITH ASSOCIATED COLD AND WARM FRONTS MOVING ACROSS THE CANADIAN
PRAIRIES. HIGH PRESSURE WAS OVER THE CENTRAL AND SOUTHERN PLAINS. DEWPOINTS
CONTINUED TO BE IN THE MODERATE LEVELS (FOR END OF MARCH) WITH LOWER
TO MID 50S DEG F DEWPOINTS ACROSS SW AND SC KANSAS.
THIS MORNING:
THE MAIN FORECAST CONCERN FOR THIS MORNING IN TERMS OF SENSIBLE WEATHER
IS IF FOG WILL DEVELOP OR NOT. THE 01Z AND 02Z HRRR RUNS WERE VERY AGGRESSIVE
IN DEVELOPING DENSE FOG ACROSS THE SW/W KANSAS. THE 04Z HRRR RUN HAS
BACKED OFF ON THIS WITH A SMALLER AREA OF DENSE FOG MAINLY ACROSS HAMILTON
COUNTY. WHAT IS INTERESTING IS THAT EVEN THOUGH THE MODEL DEVELOPS THE
FOG, THE MODELS ALSO HAS DOWNSLOPE SSW AS THE SFC. THIS IS NOT CONDUCIVE
FOR DENSE FOG FORMATION ACROSS MY COUNTY WARNING AREA. VSREF ALSO SHOWED
SOME HIGHER PROBABILITIES FOR LOWER VIS ACROSS THE AREA. OTHER MODEL
GUIDANCE IS LESS SUGGESTIVE FOR FOG FORMATION. DESPITE THIS, OBSERVATIONS
ACROSS OKLAHOMA SHOW SOME PATCHY FOG DEVELOP THIS MORNING SO I HAVE
DECIDED TO MEET THE MODELS IN BETWEEN AND INSERT PATCHY FOG ACROSS MY
WESTERN COUNTIES. DEWPOINTS ARE CURRENTLY IN THE 50S DEG F WITH UPSLOPE
SE/S WINDS SO THE POTENTIAL CANNOT BE COMPLETELY DISMISSED ATTM.
TODAY:
500 HPA FLOW WILL BECOME MORE MORE WESTERLY THROUGH TODAY, WHICH WILL
STRENGTHEN LEE TROUGHING. AS A RESULT, A WARM AIR ADVECTION PATTERN
WILL BE IN PLACE TODAY WITH TEMPERATURES WARMING WELL ABOVE NORMAL.
MID 80S DEG F ARE EXPECTED FOR HIGHS TODAY, WHICH IS ABOUT 20 DEGREES
ABOVE NORMAL. THIS WARM MARCH WE HAVE BEEN EXPERIENCING WILL END ON
A VERY WARM NOTE FOR THE LAST DAY IN THE MONTH. TODAY WILL BE PRECIPITATION
FREE AS A FAIRLY FLAT UPPER LEVEL RIDGE PREVAILS ACROSS KANSAS. I HAVE
GONE WITH SLIGHTLY COOLER TEMPERATURES TODAY (MID 80S DEG F VERSUS UPPER
80S DEG F) AS RECENT VERIFICATION PER BOI VERIFY SHOWS THAT MODELS ARE
SUFFERING A BIT OF WARM BIAS. SOUTHERLY WINDS OF 15 TO 20 KT ARE EXPECTED
THIS AFTERNOON AS MIXING INCREASES TO ABOUT 750 HPA AND SOME STRONGER
WINDS MIX DOWN.
TONIGHT:
THE LEE SURFACE TROUGH AXIS WILL MOVE SLIGHTLY EASTWARD TONIGHT AND
FRAGMENT TOWARDS SUNDAY MORNING. THIS WILL KEEP SOUTHERLY WINDS IN THE
FORECAST OVERNIGHT. DEWPOINTS IN THE 30S DEG F WEST TO 50S DEG F EAST
WILL KEEP OVERNIGHT LOWS ON THE MILD SIDE, PARTICULARLY ACROSS SOUTH
CENTRAL KANSAS. HAVE AROUND 60 DEG F TOWARDS KP28 (MEDICINE LODGE, KS)
AND COOLER MID 40S NEAR K3K3 (SYRACUSE, KS).
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 322 AM CDT SAT MAR 31 2012
MODELS REMAINING VERY CONSISTENT WITH PREVIOUS RUNS AND KEEP
SUNDAY SUNNY AND WARM . 850MB 00Z MONDAY TEMPERATURES STILL
SUPPORT HIGHS AROUND 90 DEGREES FOR MUCH OF SOUTHWEST KANSAS.
THESE HIGHS FOR THE FIRST OF APRIL COULD EASILY SET NEW RECORD
HIGHS IN A FEW LOCATIONS. A FEW RECORDS FOR APRIL FIRST ARE....88
DEGREES AT DODGE CITY, 87 AT GARDEN CITY AND 93 DEGREES AT
MEDICINE LODGE.
IN ADDITION TO THIS UNSEASONABLY WARM TEMPERATURES...LOW DEW
POINTS WILL BE SPREADING INTO PORTIONS OF WESTERN KANSAS BEHIND A
DRYLINE. THIS WILL RESULT IN AFTERNOON RELATIVE HUMIDITIES
BOTTOMING OUT IN THE 10 TO 15 PERCENT RANGE IN SEVERAL LOCATIONS.
GIVEN THESE LOW RELATIVE HUMIDITIES ALONG WITH GUSTY SOUTHWEST
WINDS DEVELOPING DURING THE AFTERNOON HAVE DECIDED TO CONTINUE THE
FIRE WEATHER WATCH ACROSS MUCH OF WESTERN KANSAS.
FOR EARLY NEXT WEEK...OUR NEXT UPPER LEVEL STORM SYSTEM IS STILL
FORECAST BY THE GFS, ECMWF, AND CANADIAN TO CROSS THE FOUR CORNERS
REGION SUNDAY NIGHT. BY MONDAY THIS SYSTEM WILL BEGIN TO DEEPEN
ACROSS NEW MEXICO WHERE IT WILL MOVE VERY LITTLE THROUGH TUESDAY.
AHEAD OF THIS SYSTEM A SOUTHEAST FLOW WILL DRAW MORE HUMID AIR
NORTHWARD TOWARDS SOUTHWEST KANSAS ON MONDAY. IN ADDITION 850MB
WARM AIR ADVECTION AND 850-700 FRONTOGENESIS WILL BE ON THE
INCREASE LATE IN THE DAY ALONG AND JUST BEHIND A COLD FRONT WHICH
WILL BE CROSSING SOUTHERN KANSAS/NORTHERN OKLAHOMA. GIVEN THIS
IMPROVING LIFT/MOISTURE AHEAD OF THE DEEPENING NEW MEXICO LOW WILL
BEGIN INCREASING CLOUD COVER AND PRECIPITATION CHANCES EARLY
MONDAY NIGHT. WINDS BEHIND THIS COLD FRONT MAY ALSO BE AN ISSUE
LATE MONDAY AND EARLY MONDAY NIGHT AS A TIGHT SURFACE PRESSURE
GRADIENT IS EXPECTED TO DEVELOP ACROSS PORTIONS OF SOUTHWEST
KANSAS IN RESPONSE TO AN AREA OF LOW PRESSURE DEEPENING ALONG THIS
FRONTAL BOUNDARY NEAR THE OKLAHOMA PANHANDLE.
TUESDAY THROUGH EARLY WEDNESDAY STILL APPEARS SOMEWHAT UNCLEAR
GIVEN THE DISAGREEMENT ON TRACK OF THIS UPPER LOW AS IT MOVES EAST
INTO THE PANHANDLE OF TEXAS. SINCE MODELS DO NOT HANDLE THESE
SYSTEM WELL, ESPECIALLY BEYOND 72 HOURS WILL FOLLOW THE GENERAL
TREND OF THE ALLBLEND THROUGH MID WEEK. HAVE THEREFORE INCREASED
PRECIPITATION CHANCES ACROSS SOUTHWEST KANSAS AND GIVEN THE CLOUDS
AND PRECIPITATION EXPECTED HAVE ALSO LOWERED TEMPERATURES TUESDAY
AFTERNOON.
BY LATE WEDNESDAY THIS UPPER LOW MOVE EAST ACROSS THE PLAINS. AS
THIS SYSTEM MOVES EAST OF WESTERN KANSAS THE SKIES WILL CLEAR AS
AN UPPER LEVEL SHORTWAVE RIDGE STARTS TO BUILD INTO THE ROCKIES
FROM THE WEST. AS THE WESTERLY DOWNSLOPE FLOW IMPROVES LATE WEEK
TEMPERATURES WILL REBOUND OUT OF 60S AND BACK INTO THE
70S...POSSIBLY A FEW 80S BY LATE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 617 AM CDT SAT MAR 31 2012
VFR CIGS ARE EXPECTED THROUGH THE TAF PERIOD. A TROUGH OF LOW
PRESSURE AT THE SURFACE NEAR THE COLORADO BORDER WILL DEEPEN TODAY
WHICH WILL RESULT IN INCREASING SOUTH WINDS ACROSS WESTERN KANSAS.
WIND SPEEDS OF AROUND 15KTS CAN BE EXPECTED AFTER 18Z.
&&
.FIRE WEATHER...
ISSUED AT 300 AM CDT SAT MAR 31 2012
MARGINAL FIRE WEATHER CONDITIONS ARE EXPECTED SATURDAY AFTERNOON, AS
THE RELATIVE HUMIDITIES WILL NOT MEET RH CRITERIA. HAVE ADDRESSED THIS
CONCERN IN FWF. NEXT CONCERN IS CRITICAL FIRE WEATHER CONDITIONS EXPECTED
SUNDAY AFTERNOON. TEMPERATURES WILL BE VERY WARM AND WINDS WILL BE STRONGER
AS LEE CYCLOGENESIS STRENGTHENS ACROSS EASTERN COLORADO AND THE RELATED
PRESSURE GRADIENT INCREASES ACROSS THE REGION. THE FUEL STATUS PAGE
SHOWS THAT STEVENS AND MORTON COUNTY ARE A NO GO AS FUELS ARE NOT AT
THE APPROPRIATE LEVELS (NOTHING TO BURN?). THIS MAY HAVE TO BE ADDRESSED
BEFORE THE RFW IS ISSUED. OTHERWISE, AFTER COLLABORATION, IT WAS DECIDED
TO CONTINUE THE FIRE WEATHER WATCH FOR FAR WESTERN KANSAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 85 56 90 53 / 0 0 0 10
GCK 86 52 90 50 / 0 0 0 10
EHA 85 51 90 50 / 0 0 0 10
LBL 86 53 92 49 / 0 0 0 10
HYS 86 58 88 53 / 0 0 0 10
P28 84 60 88 58 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR KSZ061-062-074-075-084-085.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1028 AM EDT SAT MAR 31 2012
.SYNOPSIS...
DRY AND SEASONABLY COOL WEATHER CAN BE EXPECTED TODAY AS HIGH
PRESSURE BUILDS ACROSS THE LOWER GREAT LAKES. A CROSSING
DISTURBANCE WILL BRING ANOTHER COLD FRONT AND THE CHANCE FOR
SHOWERS ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
CLOUDS CONTINUE TO HANG TOUGH IN THE COLD AIR ADVECTION. PUSHED
BACK BKN CONDITIONS A FEW HOURS BASED ON LATEST RUC SOUNDINGS. THE
REST OF THE FORECAST REMAINS UNCHANGED. DIURNAL TRACE TODAY SHOULD
BE AROUND 10F OR LESS.
DECREASED CLOUDS AND DRIER AIR MASS WL SUPPORT RADIATIVE COOLING
AS LIGHT SURFACE WIND VEERS WITH THE ADVANCE OF A SHORTWAVE IN THE
AFOREMENTIONED NORTHWEST FLOW. OVERNIGHT TEMPERATURES WERE ALSO
FORECAST NR THE NORMALS USING SREF MEANS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
AMPLIFYING RIDGE OVR THE MS VALLEY WILL STEEPEN THE NW FLOW OVER
THE AREA DURING THE SHORT TERM. LATEST MODEL RUNS SHOW A
SHORTWAVE TROUGH DIVING SOUTHEAST ACROSS THE EASTERN GREAT LAKES
SUNDAY INTO SUNDAY NIGHT. MODELS CONT TO INDICATE VARYING DEGREES
OF QPF AS THAT FEATURE PUSHES A COLD FRONT ACROSS THE REGION. WL
MAINTAIN CHANCE POPS FOR PASSAGE OF THIS SYSTEM...AND HAVE USED A
GUIDANCE BLEND WITH COOLER TEMPERATURES THAN PREVIOUS FORECAST FOR
MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
WRN STATES TROF IS FORECAST TO DVLP TWD THE PLAINS/WRN LAKES BY
MONDAY NGT...PUSHING THE RIDGE ACRS THE ERN HALF OF THE COUNTRY
BEFORE DIGGING AN EAST COAST TROF BY THE END OF THE PD. GIVEN MDL
DIFFERENCES...HAVE GENLY PERSISTED WITH THE PREVIOUS LONG TERM
FORECAST...BUT A BRIEF TEMPERATURE MODERATION AND MID WEEK CDFNT
CAN BE ANTICIPATED FOR THE LONG TERM PD.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
CIGS ARE STILL IFR / LOW END MVFR AND THAT WILL PERSIST THROUGH
THE EARLY AFTN HOURS WHEN BASES LIFT TO MVFR LEVELS ABV 2KFT. STILL
EXPECT CIGS TO CARRY THROUGH MOST OF THE AFTN. VFR CONDITIONS WILL
RETURN BY EARLY EVENING.
OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY...
NO WIDESPREAD IFR WEATHER EXPECTED.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
NEAR TERM...98
AVIATION...98
AREA FORECAST DISCUSSION
NWS DULUTH MN
635 AM CDT SAT MAR 31 2012
.AVIATION...12Z TAFS.
IFR/LIFR CIGS/VSBYS WITH FOG AT ALL SITES...AND -DZ AT KDLH. THE
FOG WILL PERSIST THROUGH 14Z-15Z WHEN APPROACHING SHORT WAVE AND
SFC FRONT WILL IMPROVE CIGS/VSBYS INTO MVFR RANGE. VCSH AT ALL
LOCATIONS EXCEPT KHYR AS SHORT WAVE/FRONT MOVE THROUGH THE FA
THROUGH 00Z SUNDAY. LLWS AHEAD OF THE FRONT. AFTER
FROPA...CIGS/VSBYS IMPROVE TO VFR.
&&
.PREV DISCUSSION... /ISSUED 331 AM CDT SAT MAR 31 2012/
SHORT TERM...
TODAY THROUGH SUNDAY AFTERNOON...
MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND THE PATCHY FOG
THROUGHOUT THE NORTHLAND WITH DENSE FOG ALONG THE NORTH SHORE AND
AROUND THE TWIN PORTS THIS MORNING...ALONG WITH RAIN SHOWERS MOVING
IN FROM THE NW TODAY...WITH PATCHY FREEZING DRIZZLE POSSIBLE IN THE
TIP OF THE ARROWHEAD BEFORE TEMPERATURES WARM LATE THIS MORNING.
UPPER LEVEL FLOW WILL REMAIN QUASI-ZONAL ACROSS MUCH OF THE CONUS
TODAY...BUT BECOME AMPLIFIED ON SUNDAY AS AN UPPER TROUGH DIGS
INTO THE WRN U.S. A WEAK 500MB S/W AND ASSOCIATED SFC TROUGH OVER
THE WRN DAKOTAS/SRN SASKATCHEWAN/MANITOBA REGION WILL TRACK TO THE
EAST THIS MORNING INTO WRN ONTARIO/NRN MN. RAIN SHOWERS WILL
ACCOMPANY THIS SYSTEM...MAINLY ACROSS THE NRN COUNTIES OF THE
FORECAST AREA. A FEW SHOWERS AND STORMS ARE ONGOING THIS MORNING
AROUND WINNIPEG...ALONG THE NRN EDGE OF A WARM/MOIST/UNSTABLE AIR
MASS BEING ADVECTED IN FROM THE SOUTH AND CO-LOCATED WITH A
NARROW BAND OF LOW LEVEL F-GEN. THIS PRECIP WILL TRY TO MOVE INTO
NE MN THIS MORNING...BUT WILL ENCOUNTER A MORE STABLE AIR MASS AND
DIMINISH IN INTENSITY THROUGH MID MORNING. THE OTHER CONCERN WITH
THIS PRECIP BAND WILL BE THE POTENTIAL FOR FREEZING DRIZZLE INTO
MAINLY LAKE AND COOK COUNTIES BEFORE 10AM. AS THE SURGE OF WARM
AIR ALOFT MOVES EWD OVER THE NEAR FREEZING SFC LAYER IN NE MN...THE
CHC FOR FREEZING PRECIP INCREASES. RUC SOUNDINGS AT ELY PRODUCE A
SATURATED THERMAL PROFILE NEAR FREEZING UP THROUGH 3000 FT...WITH
A VERY DRY LAYER ALOFT. SFC WINDS WILL EVENTUALLY VEER TO THE S/SW
AND USHER IN WARMER AIR FROM THE SOUTH BY LATE MORNING
TODAY...WHICH WILL ALLOW ANY PRECIP TO BECOME ALL LIQUID. LIQUID
PRECIP AMTS WILL RANGE FROM A TRACE UP TO A COUPLE TENTHS OF AN
INCH.
THE OTHER CONCERN IN THE SHORT TERM IS THE DENSE FOG AROUND THE
PERIPHERY OF LAKE SUPERIOR THIS MORNING. THE COMBINATION OF A
MOISTURE SFC LAYER...CONTINUOUS INFLUX OF COOL MOIST AIR FROM THE
EAST...AND A STRONG INVERSION AT THE TOP OF THE BOUNDARY LAYER ARE
ALL AIDING IN THE FORMATION AND PERSISTENCE OF FOG AROUND THE
NORTHLAND. WILL LIKELY SEE THE FOG CONTINUE TODAY AS LONG AS THE
WINDS REMAIN FROM THE EAST OFF THE LAKE. THE APPROACHING SFC
TROUGH SHOULD WIN OUT AND ALLOW WINDS TO VEER TO THE S/SW...WHICH
WILL HELP MIX DOWN SOME DRIER AIR ALOFT AND ERODE THE FOG LAYER BY
LATE MORNING. USUALLY TAKES LONGER THAN EXPECTED...SO MAY NEED TO
EXTEND DENSE FOG ADVISORY LONGER THAN 10AM. HOWEVER...FOR NOW WILL
KEEP WITH 10AM AS THE ENDING TIME.
THE DURATION OF THE EAST WINDS AND CLOUD LAYER WILL ALSO MITIGATE
HOW WARM TEMPERATURES GET TODAY. WITH CLOUD COVER EXPECTED THROUGH
A GOOD PORTION OF THE DAY...DECIDED TO DROP MAX TEMPS
TODAY...MAINLY IN NW WI. KEPT WITH 60S FOR INLAND LOCATIONS OF NE
MN...AND 40S AND 50S AROUND THE LAKE. TEMPS COOL INTO THE 30S AND
40S TONIGHT...AND WARM BACK INTO THE 60S AND LOWER 70S INLAND ON
SUNDAY...WITH 50S AROUND THE LAKE AS EAST WINDS RETURN. RIDGE OF
HIGH PRESSURE BUILDS IN ACROSS THE NRN PLAINS SUNDAY AS THE NEXT
SYSTEM PREPARES TO MOVE IN FROM THE SW SUNDAY NIGHT.
LONG TERM...
SUNDAY NIGHT THROUGH FRIDAY...
MODEL DIFFERENCES WITH THE MAGNITUDE OF THE FLATTENING/MOVING OF
THE UPPER RIDGE AND THE APPROACHING CLOSED UPPER LOW MOVING
THROUGH CANADA SUNDAY NIGHT. THIS ALSO PLAYS A ROLE IN THE AMOUNT
OF INSTABILITY FOR THUNDERSTORM DEVELOPMENT. USED A BLEND OF
QPF/POPS WITH THE MAJORITY OF THE THUNDERSTORMS HOLDING OFF UNTIL
AFTER 06Z MONDAY. THIS IS WHEN THETAE ADVECTION IS GREATEST. MODEL
DIFFERENCES CONTINUE ON MONDAY AS THE GFS IS QUICK TO MOVE A FRONT
THROUGH THE FA WHILE THE ECMWF/GEM/UKMET ARE THE SLOWEST. HAVE
SIDED WITH THE SLOWER APPROACH WHICH KEEPS THE INSTABILITY AXIS
NEARBY AND THE MENTION OF THUNDERSTORMS NEEDED. CONTINUED WITH THE
SLOWER MODELS MONDAY NIGHT AND LINGERED THE POPS. AN UPPER LEVEL
TROF MOVES THROUGH THE FA TUESDAY PUSHING THE PCPN E ALLOWING SFC
RIDGING TO BUILD IN. THE SFC HIGH BECOMES ANCHORED OVER THE
EASTERN GREAT LAKES TUESDAY NIGHT THROUGH FRIDAY KEEPING THE AREA
IN AN EASTERLY FLOW AND NO PCPN WITH THE DRY AIR FROM THE HIGH
LOCKED INTO THE FA.
AVIATION...06Z TAFS...
SKIES HAD CLEARED OVER KBRD...BUT MVFR CEILINGS HAVE ALREADY MOVED
BACK IN. IFR OR LOW MVFR CONDITIONS WILL PERSIST TONIGHT...WITH SOME
MIXED PRECIPITATION ACROSS THE FAR NORTH. DENSE FOG CAN BE
EXPECTED AROUND LAKE SUPERIOR. LATEST MODEL RUNS SUGGEST THE LOW
CEILINGS WILL BE SLOWER TO CLEAR ON SATURDAY...AND WE DELAYED THE
TIMING BY 1 TO 3 HOURS IN THE 06Z TAFS.
A SHORTWAVE AND TROUGH WILL ALSO BRING A CHANCE FOR SHOWERS
THROUGH SATURDAY...WITH THE BEST CHANCE ACROSS THE FAR NORTHEAST.
&&
.POINT TEMPS/POPS...
DLH 57 38 56 40 / 20 10 10 40
INL 60 33 60 40 / 30 10 10 30
BRD 66 43 72 51 / 10 10 10 20
HYR 58 40 68 47 / 10 10 10 30
ASX 56 39 57 43 / 10 10 10 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ020-021-
037.
WI...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR WIZ001.
LS...NONE.
&&
$$
SHORT TERM...TENTINGER
LONG TERM....GSF
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS JACKSON MS
1027 AM CDT SAT MAR 31 2012
.UPDATE...
OVERALL...HAVE MADE NO ADJUSTMENTS TO THE FORECAST FOR LATER TODAY
INTO THIS EVENING...BUT THERE ARE STILL MANY UNCERTAINTIES REGARDING
THE EXPECTED CONVECTIVE SCENARIO. IN TERMS OF ATMOSPHERIC MASS
CONTINUITY...THE ARKLAMISS CURRENTLY RESIDES IN SOMEWHAT OF A
"SINKHOLE" AS AN MCV CONTINUES TO MOVE EAST OF THE AREA ALONG THE FL
PANHANDLE REGION WHILE A COLD FRONT REMAINS WELL TO OUR NORTH ACROSS
THE MID MS/LOWER OH VALLEY REGION. IN ADDITION...A WEAK UPPER LEVEL
TROUGH OVER THE OZARK/ARKLATEX REGION IS ASSOCIATED WITH WANING TSTM
ACTIVITY.
SO DIVERGENT LOWER LEVELS ARE MAKING FOR A RATHER HOMOGENEOUS
AIRMASS OVER THE ARKLAMISS WITH NO REALLY DISTINGUISHABLE SFC
FEATURES. THE ONE EXCEPTION TO THIS MAY BE DUE TO A LINGERING STRATUS
DECK ALONG THE I-20 CORRIDOR TRAPPED BENEATH A STOUT MID LEVEL
INVERSION AND WEAK DEEP LAYER FLOW. THIS MOISTURE IS SLOW TO MIX OUT
AND IS CREATING DIFFERENTIAL BOUNDARIES TO THE NORTH AND SOUTH...BUT
EXPECT STRATUS TO MIX OUT WITH CONTINUED HEATING ALLOWING ANY
BOUNDARIES TO WASH OUT.
GIVEN THE LACK OF FOCUSING MECHANISMS...THE LATEST MODEL GUIDANCE IS
STRUGGLING TO DEVELOP MUCH CONVECTIVE PRECIPITATION OVER THE AREA
LATER THIS AFTERNOON/EVNG. THE HRRR DEVELOPS DISORGANIZED DIURNAL
SHOWER/ISO TSTMS OVER CNTRL/ERN MS BETWEEN 17-20Z AND THIS WILL BE
THE BASIS FOR KEEPING CURRENT TSTM CHANCES IN GRIDS...BUT OTHERWISE
THE ONLY CONVECTION IT DEVELOPS IS AHEAD OF THE COLD FRONT TO OUR
NORTH WHICH IS NOT FORECAST TO REACH THE ARKLAMISS. WILL CONTINUE TO
MONITOR THE TRENDS FOR THE POTENTIAL OF STRONG/SVR TSTMS. AM
RELUCTANT TO MAKE ANY CHANGES AT THIS POINT GIVEN INCREDIBLY STEEP
MID LEVEL LAPSE RATES (CURRENT 700-500MB ~8.0 DEG C/KM) AND
DECREASING CONVECTIVE INHIBITION WITH CONTINUED HEATING. THE
CONDITIONAL RISK FOR SEVERE HAIL SHOULD VIGOROUS CONVECTIVE
DEVELOPMENT TAKE PLACE IN A FASHION SIMILAR TO RECENT RUNS OF THE
HIGH-RES WRF WARRANTS KEEPING THE HAZARDOUS WEATHER PRODUCTS AS
THEY ARE FOR NOW. /EC/
.PREV DISCUSSION... /ISSUED 420 AM CDT SAT MAR 31 2012/
DISCUSSION...SHORT TERM(TODAY THROUGH SUNDAY NIGHT)
A FRONTAL BOUNDARY DROPPING SWD THROUGH THE OH VALLEY EXTENDED INTO
THE OZARKS AND SHOULD CROSS THE I-40 CORRIDOR ABOUT MIDDAY TODAY.
EXPECT SKIES IN OUR AREA TO BECOME PARTLY CLOUDY IN THE WAKE OF THE
COASTAL DISTURBANCE WITH RAPID DESTABILIZATION THIS AFTERNOON. NAM12
PROGS POCKETS OF MLCAPES REACHING 3000J/KG ALONG THE HIGHWAY 82
CORRIDOR IN CONJUNCTION WITH 7-500MB LAPSE RATES OF NEARLY 8.5C.
MEANWHILE...A WELL-DEFINED 300MB SHORTWAVE IN THE MO VALLEY EXPECTED
TO CROSS THE MID SOUTH THIS AFTERNOON HELPING TO SET OFF THE STRONG
TO SEVERE ROUND OF STORMS FOR ROUGHLY OUR N AND E CWFA PORTIONS
BETWEEN 2PM AND 9PM. THE STORMS SHOULD DRIFT SEWD ONCE THEY FORM BUT
RATHER WEAK LOW- MID LEVEL SHEAR WILL LIMIT THE PEAK STORM INTENSITY
TO MAINLY HAIL UP TO HALF-DOLLAR SIZE AND DAMAGING WIND GUSTS OF 50
TO 60 MPH.
ONCE THE TROUGH AXIS PASSES THE AREA 00-03Z THIS EVENING...RAIN
CHANCES WILL WANE THROUGH THE NIGHT TIME EXCEPT FOR SOME LINGERING
SHRA CHANCES IN ERN MS. EXPECT PATCHY FOG AGAIN LATE TONIGHT...
ESPECIALLY WHERE ANY RAINFALL OCCURS.
ON SUNDAY...MID LEVEL SUBSIDENCE RIDGE BUILDING WITH DRY AIR MIXING
TO THE SURFACE IN THE AFTERNOON. AN ISOLATED STORM APPEARS EVEN LESS
LIKELY AS PWATS DIP BELOW 1 INCH AND WILL KEEP POPS AT 5 PERCENT FOR
NOW. HOT AFTERNOON TEMPS WOULD SEEM TO BE THE MAIN FEATURE AS HIGHS
PUSH 85-90F WITH EXPECTED NEAR TOTAL SUNSHINE ONCE EARLY MORNING FOG
BURNS OFF. THE RIDGE HOLDS THROUGH SUNDAY NIGHT WITH TEMPS SAGGING
BACK INTO THE LOWER 60S AT MOST LOCATIONS. LOOK FOR AN EVEN NARROWER
WINDOW FOR ANY LATE NIGHT PATCHY FOG DEVELOPMENT. /40/
LONG TERM...MONDAY THROUGH NEXT SATURDAY
OVERALL MODEL ENVELOPE SLOWS THROUGH THE PERIOD WITH SOMEWHAT BETTER
AGREEMENT INITIALLY ON MON BUT DIVERGES BY WED/THU TIME FRAME. THIS
HAS RESULTED SOME DECENT POP/TEMP CHANGES THROUGH THE PERIOD. IN
ADDITION...THE QUESTION OF `WHEN` THE FRONTAL PASSAGE WILL OCCUR HAS
CHANGED TO `IF` A FRONTAL PASSAGE WILL OCCUR IN THE MID TO LATE-WEEK
TIME-FRAME.
HAVE FAVORED A BLEND OF THE GEM/GFS ENSEMBLE/DGEX WITH SOME
WEIGHTING TO THE 00Z OPS GFS WHILE DISCOUNTING THE 12Z/00Z EC. THE
GEM/GFSENS (INCLUDING INDIVIDUAL MEMBERS)/DGEX FAVOR A SLIGHTLY MORE
PROGRESSIVE...YET SLOWER TIMING WISE FROM PREVIOUS RUNS...TRACK OF
THE SRN-STREAM H5 CUT-OFF LOW TUES-THURS WHILE THE EC REMAINS THE
SLOWEST AND DEEPER SYSTEM THRU MID-WEEK. OF NOTE...THE 00Z EC DID
TREND FASTER THAN ITS 12Z COUNTERPART...FURTHER SUPPORTING THE
FASTER NWP ENVELOPE.
OVERALL SYNOPTIC PATTERN MONDAY WILL FEATURE DECENTLY-AMPLIFIED
LONGWAVE TROUGH IN THE TRANSITION OF CUTTING OFF OVER NEW MEXICO
WITH H5 RIDGING OVER LOWER TO MID-MS VALLEY. SOME SMALLER S/WV
TROUGHS WILL BE EMBEDDED IN THE SW FLOW FROM THE SABINE TO LOWER-MS
VALLEYS. THE IN SITU AIRMASS WILL BE BORDERLINE HOT AND MOIST WITH
AFTN TEMPS IN THE M/U80S AND DEWPOINTS IN THE L60S. A FEW STRONG TO
SEVERE PULSE TO MULTI-CLUSTER TSTORMS COULD BE POSSIBLE ACROSS SOUTH
AND WEST AREAS MON AFTN GIVEN NEAR 2.5-3.5K J/KG MUCAPE...L30
VT`S...AND S/WV`S PROGGED TO EJECT AHEAD OF PARENT CUT-OFF LOW. MAIN
SEVERE RISK WILL BE HAIL AND GUSTY WINDS TO 60 MPH. ROBUST TSTORMS
SHOULD DIMINISH SLOWLY AFTER SUNSET BUT ISO/SCT SHOWER ACTIVITY
COULD CONTINUE THROUGH MUCH OF THE OVERNIGHT INTO TUES.
FOR TUES...CNTRL AND WEST AREAS WILL HAVE BEST CHANCES FOR PULSE
RAIN/TSTORMS WITH CONTINUED S/WV AND INSTABILITY INFLUENCE AS THE
NOW COMPLETELY CUT-OFF LOW TRANSITS ACROSS SRN PLAINS. THIS WILL
HELP FEED ~1.6 IN PWATS NRD ACROSS ARKLAMISS REGION AHEAD OF SLOWLY
APPROACHING COLD FRONT STILL IN EAST TX.
DUE TO SLOWER OVERALL EVOLUTION...(WHILE BEING ON THE MORE
PROGRESSIVE ENVELOPE) WED POPS WERE INCREASED SUBSTANTIALLY AS
DEEP-LYR WIND SHEAR INCREASES OVERTOP UNSTABLE SECTOR AS THE COLD
FRONT APPROACHES WRN ARKLAMISS REGIONS BY LATE WED. THE BEST LIFT
APPEARS NOW TO BE DISPLACED FARTHER NORTH WITH OVERALL REDUCTION IN
SEVERE POTENTIAL FROM CURRENT ADVERTISED HWO/GRAPHICS WITH
ADJUSTMENTS FORTH-COMING. HOWEVER...DECENT COVERAGE OF
SHOWER/TSTORMS WILL BE LIKELY GIVEN FAVORABLE ENVIRONMENTAL
CONDITIONS.
AS POSED EARLIER...BY THURSDAY...THE QUESTION BECOMES IF THE FRONT
WILL BE ABLE TO MAKE IT THROUGH THE REGION OPPOSED TO THE PREVIOUS
NEAR CERTAINTY. 00Z OPS GFS SHOWS SFC FRONT STALING NW OF REGION BUT
ELEVATED DEWPOINT BOUNDARY APPEARS TO MAKE IT THROUGH. THE 00Z EC
BEING DEEPER...INDICATES SFC FRONT WILL MAKE IT THROUGH COMPLETELY.
THUR COULD HAVE THE LEAST RAIN COVERAGE WITH LOW-LVLS MINUS NEAR SFC
BL TO DRY TO SUPPORT DEEPER SHOWER DEVELOPMENT. FOR FRI-SAT
TIME-FRAME...BL APPEARS TO RECOVER POSSIBLY ALLOWING FOR MORE
SHOWER/TSTORM ACTIVITY UNDER WEAK H7-H5 RIDGING. /ALLEN/
&&
.AVIATION...FOG AND LOW STRATUS WILL CONTINUE TO LIFT THIS MORNING
WITH PATCHES OF IFR/LIFR CIGS/VSBY POSSIBLE THROUGH 16Z. VFR
SCATTERED CLOUDS ARE EXPECTED AFTER 16Z. SCT SHWRS/TSTMS WILL BE
POSSIBLE OVER NORTH/EAST PORTIONS OF THE AREA AFTER 19Z WITH
ISOLATED COVERAGE POSSIBLE OVER THE REMAINDER OF THE AREA. AN UPPER
LEVEL DISTURBANCE MOVING SEWD FROM THE OZARKS SHOULD CONCENTRATE THE
MOST INTENSE STORMS N OF HIGHWAY 82 AS A COLD FRONT APPROACHES THE
AREA FROM THE TN VALLEY 22-02Z. CONDITIONS EXPECTED TO REMAIN VFR
EARLY TONIGHT BEFORE PATCHY MVFR FOG DEVELOPS AFTER 07Z.
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
614 AM CDT SAT MAR 31 2012
.AVIATION...12Z KGRI TAF. SHOULD SEE VFR CONDITIONS THROUGHOUT THE
FORECAST PERIOD. SOUTHWEST WINDS WILL PICK UP AROUND LUNCHTIME AS
TEMPERATURES QUICKLY RISE AND GOOD MIXING TAKES PLACE. WINDS
ARE NOT OVERLY IMPRESSIVE A FEW THOUSAND FEET UP AND AND WILL KEEP
GUSTS TO AROUND 20 KTS. BY SUNSET...WINDS SHOULD BACK OFF TO NEAR
8-10 KTS. MAY SEE JUST A FEW HIGH BASED CU THIS AFTERNOON ALTHOUGH
CONVECTIVE TEMPS PRETTY HIGH. ALSO JUST A SLIGHT CHANCE OF SOME
FOG LATE IN THE PERIOD BUT WILL LEAVE OUT FOR NOW.
&&
.PREV DISCUSSION... /ISSUED 330 AM CDT SAT MAR 31 2012/
SHORT TERM...TODAY THROUGH MONDAY NIGHT. THE PATTERN ALOFT
FEATURED SUBTLE RIDGING ACROSS THE CENTRAL PLAINS AND RIDGE IS
FORECAST TO EXPAND/BUILD THIS WEEKEND AS PACIFIC TROUGH REACHES THE
WESTERN CONUS. THIS WILL ALLOW A VERY WARM AIRMASS...ON THE ORDER
OF +3.3 STANDARD DEVIATIONS FOR H85 TEMPS...TO SETTLE ACROSS THE
CENTRAL PLAINS...AND FORECAST SOUNDINGS SUGGEST MIXING WILL BE
EVEN HIGHER THAN THIS LEVEL. RIDGE AXIS WILL SHIFT EASTWARD ON
SUNDAY AS UPPER TROUGH MOVES INTO THE ROCKIES WITH FLOW ALOFT
TRANSITIONING SOUTHWESTERLY. THE UPPER LOW IS FORECAST TO EMERGE
ONTO THE PLAINS MONDAY/MONDAY ALTHOUGH MODELS ARE NOT CONSISTENT
ON THE TRACK OF SYSTEM ATTM AND FOLLOWED CLOSER TO ENSEMBLES FOR
NOW.
HEADING INTO TODAY...MODELS HINT AT AN OUTSIDE CHCS FOR SOME LIGHT
CONVECTION PRIOR TO DAYBREAK IN PRESENCE OF SOME MID LEVEL WAA
ACROSS OUR NORTHERN COUNTIES. WILL MONITOR TRENDS OF THIS FOR THE
NEXT SEVERAL HOURS. THIS MORNING INTO EARLY AFTN A WEAK SURFACE
TROUGH WILL SLIDE EAST ACROSS NEBRASKA SHIFTING WINDS WESTERLY CAUSING
MOISTURE AXIS TO SHIFT EASTWARD. MODEL FORECAST SOUNDINGS SUGGEST
MIXING THIS AFTN AROUND H75 WITH WINDS AT THE TOP OF THE LAYER
ROUGHLY BETWEEN 11KTS AND 20KTS ACROSS OUR WESTERN CWA WHILE RH
VALUES DROP NEAR TO BELOW 20 PERCENT GENERALLY WEST OF HIGHWAY
281. LOCATIONS FROM ROUGHLY ORD TO LEXINGTON TO ARAPAHOE LOOK LIKE
THEY WILL MEET THE LOW RH CRITERIA FOR 3HRS WITH MAIN QUESTION
BEING WILL WINDS BE GUSTY ENOUGH FOR FIRE WEATHER HEADLINE.
SURFACE GRADIENT RELAXES SOME IN OUR WEST FOLLOWING BOUNDARY AND
MODELS SUGGEST SFC DPS MAY ACTUALLY RISE SOME IN AFTN AS WEST
WINDS TURN MORE SOUTHWESTERLY. FIRE WEATHER HEADLINE IS NOT A SLAM
DUNK DUE TO UNCERTAINTY IN WIND SPEEDS. HRRR WIND GUSTS DECREASE
ACROSS OUR WEST THIS AFTN AND THIS IS SUPPORTED BY 06Z NAM
SOUNDINGS WHERE WINDS AT THE TOP OF THE MIXED LAYER DECREASE
BETWEEN 21Z AND 00Z. GIVEN THE DECREASING WIND TREND WILL NOT GO
WITH HEADLINE ATTM AS OUR STRONGER WINDS WILL RESIDE EAST OF OUR
LOW RH AREA. THAT BEING SAID...DAY SHIFT WILL NEED TO CLOSELY
MONITOR FOR RED FLAG CONDITIONS.
HIGH TEMPERATURES THIS AFTERNOON LOOK TO BE NEAR OR AT RECORD
BREAKING LEVELS. RECORD FOR GRAND ISLAND TODAY IS 90F SET IN 1978.
RECORD FOR HASTINGS IS 89F SET IN 1946 AND RECORD FOR KEARNEY IS
88F SET IN 1946. CURRENT FORECAST HAS MAX TEMPS RIGHT AROUND THESE
RECORD READINGS AND MARCH WILL DEFINITELY END ON A HOT NOTE.
OVERNIGHT...THE SURFACE TROUGH DEEPENS ALONG THE HIGH PLAINS AND
MOISTURE MAKES A BETTER SURGE NORTH THRU KS INTO SOUTHERN NEBRASKA.
THE GFS MORE SO THAN THE NAM SUGGESTS POTENTIAL FOR SOME LOW CLOUD
DEVELOPMENT MAINLY ACROSS NC KS AND INCREASED CLOUD COVER AND
INCLUDED SOME PATCHY FOG FOR NOW.
ON SUNDAY...THE SURFACE LOW DEEPENS IN EASTERN COLORADO WITH
SOUTHERLY LLVL FLOW INCREASING ACROSS OUR CWA. MOISTURE AXIS ALIGNS
ACROSS THE EASTERN HALF TO TWO THIRDS OF OUR CWA WITH SFC DPS
PROGGED NEAR 60F IN OUR FAR EAST. THE UNSEASONALLY WARM/HOT AIRMASS
REMAINS IN PLACE ACROSS OUR REGION AND WE WILL SEE ANOTHER DAY OF
HIGHS IN THE UPPER 80S TO NEAR 90F WHICH ARE AGAIN NEAR OR ABOVE
RECORDS FOR THE FIRST OF APRIL. SUNDAY NIGHT...SFC COLD FRONTAL
BOUNDARY IN NW NEBRASKA ADVANCES SOUTHEAST INTO OUR CWA...REACHING
ALL BUT OUR SOUTHEAST ZONES BY MORNING. GFS SUGGESTS PCPN MAY
DEVELOP IN VCNTY OF FRONT MAINLY ACROSS OUR NORTHERN ZONES...HOWEVER
SREF AND OTHER MODELS ARE NOT OVERLY SUPPORTIVE OF THIS ATTM AND
WILL KEEP THINGS DRY FOR THE TIME BEING.
OF BIGGER CONCERN TOWARD DAYBREAK MONDAY AND THROUGH THE DAY ON
MONDAY IS THE INCREASING NORTH WINDS FOLLOWING FROPA. MODELS
INDICATE 6HR PRESSURE RISES BEHIND THE BOUNDARY IN EXCESS OF 10MB TO
OUR WEST ALONG THE HIGH PLAINS AND AROUND 8MB ACROSS OUR CWA MIDDAY
MONDAY. GRADIENT REMAINS TIGHT THROUGH THE DAY AND ALL INDICATIONS
FM MODELS SUGGEST WE WILL AT A MINIMUM REACH WIND ADVISORY CRITERIA
AND PORTIONS OF OUR WEST MAY BE NEAR HIGH WIND WARNING CRITERIA AND
WILL NEED TO MONITOR CLOSELY.
THE UPPER LOW SHIFTS EAST ONTO THE SOUTHERN PLAINS TOWARD THE TX/OK
PANHANDLES MONDAY NIGHT. GFS IS FARTHER NORTH WITH CENTER OF SYSTEM
THAN ECMWF AND HAVE PLAYED MIDDLE GROUND AND FOLLOWED CLOSER TO
ENSEMBLE SOLUTIONS FOR NOW. PCPN CHCS INCREASE MONDAY NIGHT FM
SOUTH TO NORTH IN INCREASING LIFT/DYNAMICS ASSOCIATED WITH UPPER
LOW. HAVE LEFT THUNDER OUT FOR NOW AS BETTER INSTABILITY REMAINS TO
OUR SOUTH BUT THIS MAY NEED TO BE ADJUSTED AS TRACK OF SYSTEM IS
REFINED.
LONG TERM...TUESDAY THROUGH FRIDAY. BIGGEST CONCERN IN THE
EXTENDED LOOKS TO BE THE TRACK OF THE UPPER LOW WHICH IS FORECAST
AFFECT OUR AREA MID WEEK.
LATEST RUN OF THE EXTENDED MODELS STILL SHOWING PLENTY OF
DIFFERENCES ON TRACK OF THE UPPER LOW. OPERATIONAL GFS IS ONE OF
THE QUICKEST SOLUTIONS AS IT TAKES THE 500 MB LOW FROM THE OK
PANHANDLE AT 12Z TUE TO THE SOUTHERN EDGE OF OUR CWA BY 12Z
WED...AND THEN PUSHES IT QUICKLY EAST TO THE NORTHEAST TIP OF
MISSOURI BY 12Z THU. OF COURSE THE PERTURBATION RUNS OF THE GFS HAVE
THE LOW ALL OVER THE PLACE. THE EC IS A LITTLE QUICKER THAN THE
PREVIOUS EC RUN AS IT MOVES THE LOW FROM ERN NEW MEXICO AT 12Z TUES
TO A LITTLE SE OF DDC AT 12Z WED...AND THEN INTO NW ARKANSAS BY 12Z
THU. THE GEM IS SIMILAR IN SPEED WITH THE SYSTEM BUT A LITTLE
FURTHER SOUTH WITH THE TRACK. ALL OF THE MODELS BRING THIS SYSTEM ON
SHORE TODAY AND THEN SPLIT THE ENERGY...TAKING SOME NORTH AND SOME
SOUTH. HOPEFULLY THE PICTURE GETS A LITTLE MORE CLEAR IN THE NEXT 24
HRS AS THE LOW MOVES ONTO THE CONUS. BIGGEST IMPLICATIONS FOR US
WILL BE DURATION OF THE PRECIPITATION. COULD SEE OFF AND ON RAIN
TUESDAY AND WED WITH A NORTHERN TRACK...OR THE NORTHERN PART OF THE
CWA MIGHT MISS OUT IF IT GOES SOUTH. IT DOES APPEAR THAT IT SHOULD
PUSH EAST ON THUR AS NEXT UPSTREAM SYSTEM IS SET TO MOVE INTO THE
WESTERN U.S. WHICH SHOULD KEEP THINGS PROGRESSIVE. INSTABILITY
LOOKS MARGINAL ON TUESDAY SO WILL KEEP THUNDER OUT FOR NOW.
OTHERWISE TEMPERATURES SHOULD STILL BE ABOVE NORMAL WITH HIGHS IN
THE UPPER 50S ON TUESDAY AND THEN CLIMBING BACK TO NEAR 70 FOR
THURSDAY AND FRIDAY. ALSO --- IT STILL DOES NOT LOOK LIKE WE WILL
GET BELOW FREEZING THROUGH THE UPCOMING WORKWEEK.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM/AVIATION...EWALD
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1043 AM EDT SAT MAR 31 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION TODAY...PROVIDING COOLER
AND DRIER WEATHER. A FRONTAL BOUNDARY WILL DROP INTO OHIO ON
SUNDAY OFFERING A CHANCE OF SHOWERS AND THUNDERSTORMS. THE THREAT
FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO THE EARLY PART OF
THE WORK WEEK WITH THE FRONT REMAINING ACROSS THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
31.12Z KILN RAOB SHOWED AMPLE LOW LEVEL MOISTURE TRAPPED BENEATH
RATHER STRONG INVERSION CENTERED AROUND 900MB. WEAK COLD ADVECTION
BELOW THE INVERSION WILL CONTINUE THROUGH MUCH OF THE
AFTERNOON...SO HAVING DOUBTS THE DEGREE OF CLEARING ANY LOCATION
WILL SEE. TIME-LAGGED RUC SOUNDINGS FROM THE LAST 6 OPERATIONAL
13KM RUNS DEFINITELY TRENDING ON HOLDING LOW LEVEL MOISTURE IN
LONGER. 31.12Z RUC 950-900MB LAYER HUMIDITIES DO IMPROVE FOR SOME
CLEARING AFTER 20Z...MOST LIKELY A MANIFESTATION OF MUCH DRIER AIR
ABOVE THIS LAYER ADVECTING IN ON WLY FLOW FROM ILLINOIS /WHERE
CLEARING TAKING PLACE/...WITH MIXING/EROSION LIKELY CHEWING SOME HOLES
IN THE THICK LOW LEVEL STRATUS INTO MID/LATE AFTERNOON. EVEN WITH
THAT...FELT PRUDENT BASED ON CURRENT TEMPS AND BLEND OF HI-RES
SHORT TERM GUIDANCE /HRRR...WRF...LAMP...RUC/ TO DROP AFTERNOON
HIGH TEMPERATURES BY A GOOD 3 TO 5 DEGREES. SHOULD SEE THE VSBYS
SLOWLY IMPROVE THROUGH THE REST OF THE MORNING...AND THIS IS
ALREADY TRENDING IN 31.12Z - 31.14Z OBS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
UPPER LEVEL RIDGE BUILDING ACRS THE NATIONS MID SECTION WITH NWRLY
FLOW DOMINATING AND SURFACE RIDGE BUILDING INTO THE OHIO VALLEY BY
SUNDAY MORNING. ANY LINGERING CLOUDS WILL GIVE WAY TO CLEARING EARLY
TONIGHT WITH SOME INCREASE IN HIGH LEVEL CLOUDS LATE. EXPECT LOWS
FROM NEAR 40 NE TO THE MID 40S SOUTH.
EMBEDDED S/W IN THE NWRLY FLOW TO DROP SE THRU THE EASTERN GREAT
LAKES SUNDAY/SUNDAY NIGHT. ASSOCIATED BACK DOOR COLD FRONT TO DROP
SOUTH INTO OHIO SUNDAY AFTN. WL CONTINUE CURRENT TREND ALLOWING FOR
CHC POPS NORTH AND ONLY MENTIONING A SLIGHT CHC ACRS THE FAR S
LATE. THE INFLUENCE OF WAA AND SOME SUNSHINE AHD OF THIS FRONT
WILL ALLOW TEMPS TO WARM TO READINGS ABOUT 15 DEGREES ABOVE
NORMAL.
NUMERICAL MODEL SOLNS DIFFER ON WHERE THE BACK DOOR FRONT STALLS
OUT. EXPECT THIS FRONTAL BOUNDARY TO PUSH SW AND LOSE ITS IDENTITY
AS THE UPPER LEVEL RIDGE BUILDS INTO THE MS VLY. WL ONLY CONT
SLIGHT CHC POPS INTO SUNDAY EVENING AND THEN ALLOW FOR A DRY
OVERNIGHT. THE REMNANTS OF THE FRONTAL BOUNDARY STALLING OUT AND
BEGINNING TO PUSH BACK NE ON MONDAY. WITH A LACK OF UPPER SUPPORT
AND BEST INSTBY REMAINING TO OUR WEST. WL LIMIT POPS TO SLIGHT CHC
OF THUNDERSTORMS MONDAY AFTN ACRS THE SW. EXPECT MONDAYS HIGH TEMPS
TO BE 10 TO 15 DEGREES ABOVE NORMAL...RANGING FROM THE LOWER 70S
NE TO THE UPPER 70S SW.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MID LEVEL RIDGING WILL BE IN PLACE ACROSS THE OHIO VALLEY BY 12Z
MONDAY MORNING WITH A WEAKENING COLD FRONT TO OUR SOUTH. THE MODELS
ARE TRYING TO SHOW THIS FRONT LIFTING BACK TO THE NORTHEAST AS A
WARM FRONT THROUGH THE DAY ON MONDAY...BUT DISAGREE ON BOTH THE
TIMING AND THE STRENGTH OF THIS FEATURE. WILL THEREFORE JUST HANG ON
TO SOME LOWER CHANCE POPS MONDAY INTO MONDAY NIGHT.
THE MODELS ARE ALSO HAVING A DIFFICULT TIME RESOLVING THE SHORT
WAVE ENERGY MOVING OUT OF THE ROCKIES THROUGH MID WEEK. BOTH THE 12Z
NAM AND 12Z CMC ARE TRYING TO CLOSE OFF A 5H LOW AS IT MOVES INTO
THE TENNESSEE VALLEY WEDNESDAY INTO THURSDAY. HOWEVER...THE 00Z
ECMWF KEEPS THE CLOSED LOW WELL BACK TO THE SOUTHWEST AND AS A
RESULT IS MUCH SLOWER TO BRING RIDGING IN FROM THE WEST THROUGH
LATE IN THE WEEK. IN FACT...THE 00Z ECMWF KEEPS A FAIRLY DEEP TROUGH
OVER THE NORTHEASTERN UNITED STATES THROUGH THE LONG TERM PERIOD. IT
LOOKS LIKE THERE WILL BE A DECENT CHANCE OF SHOWERS AND
THUNDERSTORMS BY TUESDAY AS THE INITIAL ENERGY APPROACHES BUT THE
QUESTION WILL BE HOW LONG ANY TREAT WILL HANG AROUND INTO THE MIDDLE
PART OF THE WEEK. WITH THE CLOSED LOW OF THE GFS/CMC WOULD THINK ANY
LINGERING PCPN WOULD MAINLY REMAIN TO OUR SOUTHWEST. MEANWHILE...ANY
PCPN PUSHING DOWN THE BACK SIDE OF THE TROUGH OF THE ECMWF SHOULD
MAINLY REMAIN TO OUR EAST. WILL THEREFORE GO WITH A DRY FORECAST
FROM MID WEEK ON...BUT CONFIDENCE IS NOT VERY HIGH WITH THIS
FORECAST. OF COURSE TEMPERATURES THROUGH THE WEEK WILL ALSO BE
AFFECTED BY ALL OF THIS. WILL GENERALLY GO WITH A BLEND OF
PERSISTENCE AND THE MODELS BUT PERHAPS TREND A LITTLE MORE TOWARD
THE COOLER ECMWF...WHICH WOULD KEEP TEMPERATURES FAIRLY SEASONABLE
THROUGH THE WEEK.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
CIGS/VSBYS ONLY VERY SLOWLY IMPROVING AT 14Z...AND WILL CONTINUE
TO DO SO. WILL NEED TO CONSIDER EXTENDING DURATION OF MVFR/IFR
CIGS AND VSBYS LATER IN THE AFTERNOON. CIGS SHOULD SCATTER OUT
LATE THIS AFTERNOON INTO THIS EVENING WITH THE POTENTIAL FOR MORE
FOG FORMATION. WILL ADDRESS THESE ISSUES IN UPCOMING 18Z TERMINALS.
OUTLOOK...SCATTERED THUNDERSTORMS POSSIBLE MONDAY INTO TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...AR
NEAR TERM...BINAU
SHORT TERM...AR
LONG TERM...JGL
AVIATION...CONIGLIO
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
700 AM CDT SAT MAR 31 2012
.DISCUSSION.../ISSUED AT 700 AM CDT/
UPDATED TO ADD MORE FOG TO AREAS EAST OF I29 THROUGH MID MORNING.
FOG WILL BE DENSE IN PLACES. THIS SHOULD BURN OFF BY MID TO LATE
MORNING.
STRATUS HAS REFORMED ACROSS PORTIONS OF SOUTHWEST MINNESOTA AND
NORTHWEST IOWA WITH LOW LEVEL SOUTHEAST FLOW. REST OF CWA HAS PLENTY
OF HIGH CLOUDS STREAMING ACROSS THE REGION. SO WILL START OUT CLOUDY
TO MOSTLY CLOUDY WITH AREAS EAST OF I29 SLOWEST TO BREAK OUT DURING
THE MID TO LATE MORNING. THIS WILL SLOW DOWN WARMUP ACROSS EAST THIS
MORNING...BUT STILL SHOULD WARM INTO 70S EAST OF I29 AND 80 TO 85 TO
THE WEST.
WEAK SHORT WAVE IS PROGGED BY MODELS TO RIDE OVER TOP OF RIDGE THIS
AFTERNOON WITH WEAK QUASI WARM FRONT DEVELOPING OVER NORTHWEST IOWA.
SOME INSTABILITY DURING THE AFTERNOON ON EDGE OF MID CAP AND COULD
SEE AN ISOLATED THUNDERSTORMS ACROSS THE FAR SOUTHEAST AND HAVE
ADDED 20% THERE AFTER 20Z.
SHOULD CLEAR OUT ACROSS CWA TONIGHT WITH EVEN WARMER TEMPERATURES ON
SUNDAY AS H85 FLOW BECOME MORE SOUTHWEST ALLOWING FOR A LITTLE
BETTER MIXING. SO SHOULD SEE HIGHS IN THE 80S AND NEAR 90 ALONG THE
MISSOURI RIVER. SHOULD BE PLENTY OF RECORDS BEING SET THIS WEEKEND.
COLD FRONT WILL PUSH INTO WESTERN CWA LATE SUNDAY AFTERNOON...BUT
STRONG CAPPING WILL PROBABLY PREVENT ANY THUNDERSTORMS DEVELOPMENT
AHEAD OF FRONT.
WILL KEEP SMALL CHANCE OF THUNDERSTORMS SUNDAY NIGHT WEST OF I29
CORRIDOR JUST BEHIND FRONT WHERE COOLER MID LEVEL TEMPERATURES MAY
BE ENOUGH TO WEAKEN CAP.
INITIAL COOLING BEHIND THE FRONT WILL BE LAGGING AND WILL NOT REALLY
MAKE ITS PUSH UNTIL SUNDAY NIGHT...WITH WINDY AND COOLER CONDITIONS
ON MONDAY. WILL KEEP A LINGERING CHANCE OF THUNDERSTORMS ALONG AND
EAST OF INTERSTATE 29 ON MONDAY BEHIND THE FRONT...BUT DYNAMICS NOT
ALL THAT IMPRESSIVE TO GO MORE THAN 20 TO 30%.
WILL BE COOLER NEXT WEEK AS MORE OF AN EAST TO SOUTHEAST LOW LEVEL
FLOW OFF OF GREAT LAKES HIGH DEVELOPS. STILL ABOVE NORMAL
TEMPERATURES BUT HIGHS MAINLY IN THE UPPER 50S TO MID 60S TUESDAY
AND WEDNESDAY AND SLIGHTLY WARMER THURSDAY AND FRIDAY. WILL NEED TO
WATCH UPPER LOW OVER SOUTHWEST US AS IT MEANDERS ACROSS THE SOUTHERN
PLAINS MID WEEK. COULD SEE A FEW SHOWERS ACROSS FAR SOUTHEAST
WEDNESDAY OR THURSDAY...BUT FOR NOW WILL LEAVE DRY AS FLOW ALOFT
SHOULD KEEP STORM TO THE SOUTH.
LOOKS LIKE IT COULD BE MORE STORMY NEXT WEEKEND AS FAIRLY DECENT
WAVE MOVES EAST ACROSS THE NORTHERN PLAINS. MODELS NOT AGREEING ALL
THAT WELL WITH TIMING OF THIS FEATURE.
FIRE DANGER LIKELY TO BE VERY HIGH OR EXTREME WESTERN CWA TODAY AND
SUNDAY...BUT WINDS NOT STRONG ENOUGH TO WARRANT FIRE WEATHER WATCH.
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
SOUTHEAST WINDS ADVECTING IN MOISTURE...COMBINED WITH NIGHTTIME
COOLING...HAS ALLOWED FOG AND LOW STRATUS TO FORM ACROSS SOUTHWEST
MINNESOTA AND NORTHWEST IOWA...WITH LIFR CIGS OF A COUPLE HUNDRED
FEET AND VISIBILITIES AT OR BELOW 2 MILES. RUC AND HRRR BACK THIS TO
THE WEST A BIT MORE THIS MORNING. THUS THINK IT WILL MAKE IT AS FAR
WEST AS ROUGHLY ALONG A SIOUX FALLS TO BROOKINGS LINE. AS THE SUN
RISES AND LOW LEVEL MIXING COMMENCES...SHOULD INITIALLY SEE THIS
REINFORCE THE LOW CLOUD DECK. HOWEVER WITH CONTINUED HEATING WE WILL
SEE THE CLOUDS BEGIN TO DISSIPATE FROM WEST TO EAST BY MID MORNING.
CURRENT THINKING HAS KFSD VFR BY AROUND 11AM. KSUX IS ALSO RIGHT ON
THE EDGE OF THE STRATUS DECK...BUT THINK THEY SHOULD REMAIN JUST TO
ITS SOUTHWEST...ALTHOUGH CAN NOT RULE OUT THEM BRIEFLY DROPPING TO
MVFR THIS MORNING.
ONCE THE LOW CLOUDS ERODE...VFR FLYING CONDITIONS SHOULD PERSIST
INTO TOMORROW MORNING. SOUTH SOUTHEAST WINDS WILL BRIEFLY TURN
NORTHERLY NORTH OF INTERSTATE 90 THIS AFTERNOON...BEFORE SWITCHING
BACK TO THE SOUTHEAST TONIGHT. WINDS ARE EXPECTED TO MAINLY REMAIN
BELOW 12 KTS THROUGH THE PERIOD. /CHENARD
&&
.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
650 AM CDT SAT MAR 31 2012
.DISCUSSION.../ISSUED AT 255 AM CDT/
STRATUS HAS REFORMED ACROSS PORTIONS OF SOUTHWEST MINNESOTA AND
NORTHWEST IOWA WITH LOW LEVEL SOUTHEAST FLOW. REST OF CWA HAS PLENTY
OF HIGH CLOUDS STREAMING ACROSS THE REGION. SO WILL START OUT CLOUDY
TO MOSTLY CLOUDY WITH AREAS EAST OF I29 SLOWEST TO BREAK OUT DURING
THE MID TO LATE MORNING. THIS WILL SLOW DOWN WARMUP ACROSS EAST THIS
MORNING...BUT STILL SHOULD WARM INTO 70S EAST OF I29 AND 80 TO 85 TO
THE WEST.
WEAK SHORT WAVE IS PROGGED MY MODELS TO RIDE OVER TOP OF RIDGE THIS
AFTERNOON WITH WEAK QUASI WARM FRONT DEVELOPING OVER NORTHWEST IOWA.
SOME INSTABILITY DURING THE AFTERNOON ON EDGE OF MID CAP AND COULD
SEE AN ISOLATED THUNDERSTORMS ACROSS THE FAR SOUTHEAST AND HAVE
ADDED 20% THERE AFTER 20Z.
SHOULD CLEAR OUT ACROSS CWA TONIGHT WITH EVEN WARMER TEMPERATURES ON
SUNDAY AS H85 FLOW BECOME MORE SOUTHWEST ALLOWING FOR A LITTLE
BETTER MIXING. SO SHOULD SEE HIGHS IN THE 80S AND NEAR 90 ALONG THE
MISSOURI RIVER. SHOULD BE PLENTY OF RECORDS BEING SET THIS WEEKEND.
COLD FRONT WILL PUSH INTO WESTERN CWA LATE SUNDAY AFTERNOON...BUT
STRONG CAPPING WILL PROBABLY PREVENT ANY THUNDERSTORMS DEVELOPMENT
AHEAD OF FRONT.
WILL KEEP SMALL CHANCE OF THUNDERSTORMS SUNDAY NIGHT WEST OF I29
CORRIDOR JUST BEHIND FRONT WHERE COOLER MID LEVEL TEMPERATURES MAY
BE ENOUGH TO WEAKEN CAP.
INITIAL COOLING BEHIND THE FRONT WILL BE LAGGING AND WILL NOT REALLY
MAKE ITS PUSH UNTIL SUNDAY NIGHT...WITH WINDY AND COOLER CONDITIONS
ON MONDAY. WILL KEEP A LINGERING CHANCE OF THUNDERSTORMS ALONG AND
EAST OF INTERSTATE 29 ON MONDAY BEHIND THE FRONT...BUT DYNAMICS NOT
ALL THAT IMPRESSIVE TO GO MORE THAN 20 TO 30%.
WILL BE COOLER NEXT WEEK AS MORE OF AN EAST TO SOUTHEAST LOW LEVEL
FLOW OFF OF GREAT LAKES HIGH DEVELOPS. STILL ABOVE NORMAL
TEMPERATURES BUT HIGHS MAINLY IN THE UPPER 50S TO MID 60S TUESDAY
AND WEDNESDAY AND SLIGHTLY WARMER THURSDAY AND FRIDAY. WILL NEED TO
WATCH UPPER LOW OVER SOUTHWEST US AS IT MEANDERS ACROSS THE SOUTHERN
PLAINS MID WEEK. COULD SEE A FEW SHOWERS ACROSS FAR SOUTHEAST
WEDNESDAY OR THURSDAY...BUT FOR NOW WILL LEAVE DRY AS FLOW ALOFT
SHOULD KEEP STORM TO THE SOUTH.
LOOKS LIKE IT COULD BE MORE STORMY NEXT WEEKEND AS FAIRLY DECENT
WAVE MOVES EAST ACROSS THE NORTHERN PLAINS. MODELS NOT AGREEING ALL
THAT WELL WITH TIMING OF THIS FEATURE.
FIRE DANGER LIKELY TO BE VERY HIGH OR EXTREME WESTERN CWA TODAY AND
SUNDAY...BUT WINDS NOT STRONG ENOUGH TO WARRANT FIRE WEATHER WATCH.
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
SOUTHEAST WINDS ADVECTING IN MOISTURE...COMBINED WITH NIGHTTIME
COOLING...HAS ALLOWED FOG AND LOW STRATUS TO FORM ACROSS SOUTHWEST
MINNESOTA AND NORTHWEST IOWA...WITH LIFR CIGS OF A COUPLE HUNDRED
FEET AND VISIBILITIES AT OR BELOW 2 MILES. RUC AND HRRR BACK THIS TO
THE WEST A BIT MORE THIS MORNING. THUS THINK IT WILL MAKE IT AS FAR
WEST AS ROUGHLY ALONG A SIOUX FALLS TO BROOKINGS LINE. AS THE SUN
RISES AND LOW LEVEL MIXING COMMENCES...SHOULD INITIALLY SEE THIS
REINFORCE THE LOW CLOUD DECK. HOWEVER WITH CONTINUED HEATING WE WILL
SEE THE CLOUDS BEGIN TO DISSIPATE FROM WEST TO EAST BY MID MORNING.
CURRENT THINKING HAS KFSD VFR BY AROUND 11AM. KSUX IS ALSO RIGHT ON
THE EDGE OF THE STRATUS DECK...BUT THINK THEY SHOULD REMAIN JUST TO
ITS SOUTHWEST...ALTHOUGH CAN NOT RULE OUT THEM BRIEFLY DROPPING TO
MVFR THIS MORNING.
ONCE THE LOW CLOUDS ERODE...VFR FLYING CONDITIONS SHOULD PERSIST
INTO TOMORROW MORNING. SOUTH SOUTHEAST WINDS WILL BRIEFLY TURN
NORTHERLY NORTH OF INTERSTATE 90 THIS AFTERNOON...BEFORE SWITCHING
BACK TO THE SOUTHEAST TONIGHT. WINDS ARE EXPECTED TO MAINLY REMAIN
BELOW 12 KTS THROUGH THE PERIOD. /CHENARD
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1020 AM EDT SAT MAR 31 2012
.SYNOPSIS...
A WEAK COOL FRONT WILL SWEEP SOUTHEAST THROUGH THE MID APPALACHIAN
AND MID ATLANTIC REGION TODAY...ACCOMPANIED BY SCATTERED TO WIDELY
SCATTERED SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD
SOUTHEAST INTO THE AREA LATER THIS AFTERNOON...AND PERSIST
THROUGH SUNDAY...ENDING THE THREAT FOR RAIN AS SKIES GRADUALLY
CLEAR.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1010 AM EDT SATURDAY...
THE COLD FRONT IS JUST ENTERING OUR SOUTHEAST WEST VIRGINIA
COUNTIES AS OF 10 AM...AS INDICATED BY FALLING DEWPOINT
TEMPERATURES AND PRESSURE RISES. WITH DRIER AIR MAKING ITS WAY
IN...CLOUD COVER WILL GRADUALLY BEGIN TO BREAK UP ACROSS OUR AREA
THROUGH THE AFTERNOON. MAIN CHANGES TO THE EARLY MORNING FORECAST
WERE TO LOWER AFTERNOON TEMPERATURES A DEGREE OR TWO ACROSS THE
PIEDMONTS...AREAS THAT WILL STILL EXPERIENCE RAIN SHOWERS THROUGH
AROUND NOON.
AS OF 335 AM EDT SATURDAY...
WEAK COOL FRONT PROGRESSING SOUTHEAST OUT OF THE OHIO VALLEY WILL
SWEEP SOUTHEAST THROUGH THE MOUNTAINS THIS MORNING...AND CONTINUE
EAST MOVING THROUGH THE PIEDMONT COUNTIES THIS AFTERNOON. LATEST
RUN OF THE HIGH RESOLUTION WRFARL AND HRRR MODELS DOING A VERY
GOOD JOB OF DEPICTING THE MOVEMENT...TIMING...AND AREAL COVERAGE
OF LINEAR SCATTERED CONVECTION IN THE VICINITY OF THE FRONT...WITH
MORE STRATIFORM AREA OF PRECIPITATION ADVANCING NORTHEAST THROUGH
THE SOUTHERN COUNTIES WHERE ISENTROPIC LIFT IS MAXIMIZED.
EXPECT TO SEE SOUTHERN STRATIFORM AREA OF PRECIPITATION MAINLY
SOUTH OF HIGHWAY 460 TO MOVE EAST OF THE BLACKSBURG FORECAST AREA
BY MID MORNING AS BEST ISENTROPIC LIFT MOVES EAST OF REGION...AND
AS LOWER TROPOSPHERIC WINDS GRADUALLY VEER INTO MORE OF A
DOWNSLOPING COMPONENT AS SURFACE LOW PRESSURE MOVES EAST TO THE
DELMARVA AREA.
MEANWHILE...FURTHER NW NEAR THE SURFACE FRONT...PAST SEVERAL HOURS
OF SATELLITE PICTURES AND SURFACE OBSERVATIONS SHOWING A MARKED
DECREASE OF CONVECTIVE ACTIVITY ALONG/NEAR FRONT DUE TO LIMITED
FORCING AND NEGLIGIBLE THERMODYNAMIC SUPPORT. SOME STRAY
SHOWERS/ISOLATED STORMS MAY REACH THE WESTERN TIER COUNTIES
SHORTLY BEFORE/AROUND DAYBREAK...SUPPORTED BY AT LEAST SOME
LIMITED UPSLOPING ALONG THE WESTERN FLANKS OF THE
APPALACHIANS...BUT ANY REIGNITING ALONG THE FRONT WILL LIKELY COME
LATER IN THE AFTERNOON AFTER THERMODYNAMIC SUPPORT INCREASES...AND
BY THEN...FRONT/SURFACE TROF LIKELY TO SOUTH AND EAST OF THE
BLACKSBURG FORECAST AREA.
DESPITE ARRIVAL AND PASSAGE OF FRONT AND ASSOCIATED CLOUDS...LITTLE
CHANGE IN AIR MASS IS EXPECTED DURING THE DAY SINCE DEEPER COOL
AIR LAGS WELL BEHIND WIND SHIFT. COMBINATION OF LINGERING CLOUDS
IN UPSLOPE AREAS OF THE WEST AND AT LEAST A FEW DEGREE REDUCTION
IN 850 MILLIBAR TEMPERATURE SHOULD PREVENT AFTERNOON READINGS
FROM REACHING THOSE EXPERIENCED ON FRIDAY. HOWEVER...DOWNSLOPING
WINDS FOLLOWING PASSAGE OF FRONT/TROF MAY VERY WELL ALLOW FOR A WARMER
DAY ACROSS MUCH OF THE PIEDMONT. ALL AND ALL...EXPECT TEMPERATURES
TO CONTINUE TO BE 10-15 DEGREES ABOVE NORMAL FOR THE LAST DAY OF
THE MONTH...GENERALLY 60S ACROSS THE WESTERN MOUNTAINS TO NEAR 80
ACROSS THE PIEDMONT. THIS WILL ENSURE THAT MOST CLIMATOLOGICAL
SITES END UP BREAKING OR BEING IN THE TOP SEVERAL WARMEST MARCHES
ON RECORD.
DRY SURFACE RIDGE OF HIGH PRESSURE BUILDING IN FROM THE NORTH AND
WEST TONIGHT SHOULD ALLOW FOR CLEARING SKIES WITH GOOD RADIATIVE
COOLING POTENTIAL. READINGS SHORTLY BEFORE DAYBREAK ON SUNDAY
EXPECTED TO RANGE FROM THE MID 30S TO LOWER 40S IN THE
MOUNTAINS...WHERE SOME PATCHY FROST MAY OCCUR IN SOME OF THE
DEEPER MOUNTAIN VALLEYS...TO THE MID AND UPPER 40S ACROSS THE
PIEDMONT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM EDT SATURDAY...
ON SUNDAY...WE ARE EXPECTING HIGH PRESSURE TO SETTLE OVER THE AREA
BY THE MORNING. A STRONGER NOSE OF HIGH PRESSURE IS EXPECTED TO HEAD
SOUTH THROUGH THE GREAT LAKES AREA LATER IN THE DAY. THIS FEATURE
MAY PROMPT A BACK DOOR COLD FRONT INTO THE AREA...WITH THE POTENTIAL
FOR SOME ISOLATED SHOWERS ALONG IT LATE IN THE AFTERNOON INTO SUNDAY
EVENING. AS THE BACK DOOR FRONT CONTINUES SOUTH THROUGH THE AREA
SUNDAY NIGHT...ANTICIPATE ISOLATED COVERAGE ACROSS
WESTERN...NORTHERN...AND EASTERN SECTIONS OF THE REGION. COVERAGE
MAY SCATTERED OVER SECTIONS OF SOUTHEAST WEST VIRGINIA.
THIS FRONT WILL BECOME STALLED OVER THE WESTERN THIRD OF THE AREA BY
MONDAY MORNING. DURING THE DAY MONDAY...AN AREA OF LOW PRESSURE WILL
BE MOVING EASTWARD THROUGH THE CENTRAL PART OF THE U.S. WIND FLOW
IN ADVANCE OF THIS FEATURE WILL TURN SOUTHERLY ACROSS THE WESTERN
GULF OF MEXICO...AND ADVECT INTO OUR REGION FROM THE SOUTHWEST. THE
RESULT WILL BE INCREASING COVERAGE OF SHOWERS ALONG THE STALLED
FRONT THANKS TO THE INCREASED MOISTURE. THE FRONT ITSELF WILL ALSO
TAKE ON MORE OF THE NATURE OF A WARM FRONT AND HEAD ACROSS THE AREA
BY MONDAY NIGHT.
ON TUESDAY...THE LOW WILL HEAD EASTWARD NEAR THE PA/MD LINE AND ITS
ASSOCIATED COLD FRONT WILL SWEEP THROUGH THE AREA. WE ARE
ANTICIPATING INCREASED CHANCES OF SHOWERS AND THUNDERSTORMS DURING
THE DAY...ESPECIALLY ACROSS THE MOUNTAINS. AREAS ALONG AND EAST OF A
FARMVILLE TO DANVILLE LINE MAY NOT SEE ANY ACTIVITY UNTIL TUESDAY
EVENING. BY TUESDAY NIGHT... MOST OF THE PRECIPITATION WILL BE SOUTH
OF THE AREA IN ASSOCIATION WITH THE COLD FRONT. LINGERING SHOWERS
WILL STILL BE POSSIBLE ACROSS THE AREA...ESPECIALLY OVER SOUTHEAST
WV WHERE NORTHWEST FLOW UPSLOPE SHOWERS ARE EXPECTED.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
WITH THE COLD FRONT PASSING THROUGH OUR AREA ON TUESDAY NIGHT AND
WEDNESDAY MORNING...EXPECT ANOTHER LARGE DOME OF CANADIAN HIGH
PRESSURE TO BUILD INTO THE UPPER MIDWEST...BRINGING OUR TEMPERATURES
MUCH CLOSER TO NORMAL FOR THE FIRST WEEK OF APRIL. WITH HIGH
PRESSURE MAINTAINING ITS CONTROL THROUGH THE BEGINNING OF NEXT
WEEKEND...THE ONLY WEATHER CONCERNS WILL BE CHILLY OVERNIGHT
TEMPERATURES...WHICH MAY APPROACH FREEZING ACROSS PARTS OF SOUTHEAST
WEST VIRGINIA...AND MAY RESULT IN OVERNIGHT FROST ELSEWHERE ACROSS
THE MOUNTAINS.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
AS OF 735 AM EDT SATURDAY...
COOL FRONT WILL SWEEP SOUTHEAST THROUGH THE SOUTHEASTERN WV
TERMINAL FORECAST POINTS THIS MORNING...AND MOVE EAST OF THE
PIEDMONT TERMINAL FORECAST POINTS BY EARLY TO MID AFTERNOON.
UPSLOPING WINDS ACROSS THE WESTERN FLANKS OF THE APPALACHIANS WILL
RESULT IN AREAS OF MVFR FLIGHT RESTRICTIONS...WITH LOCALIZED IFR
CONDITIONS ALONG WITH MOUNTAIN TOP OBSCURATIONS INTO MID MORNING...
ESPECIALLY SOUTH OF BLUEFIELD INTO THE NW NC MOUNTAINS...WHERE
RAIN FELL OVERNIGHT. ELSEWHERE...VEERING WINDS IN LOWER TROPOSPHERE
AS LOW PRESSURE MOVES EAST AND OFF DELMARVA COASTLINE WILL RESULT
IN DEVELOPMENT OF DOWNSLOPING WINDS EAST OF THE BLUE RIDGE...
ENSURING THAT MAINLY VFR CONDITIONS PREVAIL IN THIS AREA DESPITE
SOME SHOWERS INTO MID MORNING SOUTH OF HIGHWAY 460.
SURFACE RIDGE OF HIGH PRESSURE BUILDING SOUTHEAST INTO THE MID
APPALACHIAN AND MID ATLANTIC REGION...AND ARRIVAL OF DRIER AIR
THIS AFTERNOON INTO SUNDAY SHOULD ENSURE CLEARING CONDITIONS WITH
VFR WEATHER TO RETURN TO EVEN THE WESTERN UPSLOPE AREAS BY EARLY
TO MID AFTERNOON.
THE NEXT THREAT FOR WIDESPREAD FLIGHT RESTRICTIONS WILL OCCUR
LATE SUNDAY NIGHT OR ON MONDAY...POSSIBLY CONTINUING INTO THE MID
WEEK PERIOD AS ANOTHER RIDGE OF HIGH PRESSURE BUILDS SOUTHWEST OUT
OF NEW ENGLAND. UPSLOPING WINDS ACROSS THE EASTERN FLANKS OF THE
BLUE RIDGE...WITH WEAK SHORT WAVES AND MOISTURE STREAMING
NORTHEAST OVER A STALLED FRONT OVER/NEAR THE AREA...MAY SET THE
STAGE FOR MVFR (AND POTENTIALLY LOWER) FLIGHT RESTRICTIONS INTO
THE MID WEEK PERIOD...ESPECIALLY OVER/IN THE MOUNTAINS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WERT
NEAR TERM...NF/WERT
SHORT TERM...DS
LONG TERM...NF
AVIATION...WERT
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
739 AM EDT SAT MAR 31 2012
.SYNOPSIS...
A WEAK COOL FRONT WILL SWEEP SOUTHEAST THROUGH THE MID APPALACHIAN
AND MID ATLANTIC REGION TODAY...ACCOMPANIED BY SCATTERED TO WIDELY
SCATTERED SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD
SOUTHEAST INTO THE AREA LATER THIS AFTERNOON...AND PERSIST
THROUGH SUNDAY...ENDING THE THREAT FOR RAIN AS SKIES GRADUALLY
CLEAR.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 335 AM EDT SATURDAY...
WEAK COOL FRONT PROGRESSING SOUTHEAST OUT OF THE OHIO VALLEY WILL
SWEEP SOUTHEAST THROUGH THE MOUNTAINS THIS MORNING...AND CONTINUE
EAST MOVING THROUGH THE PIEDMONT COUNTIES THIS AFTERNOON. LATEST
RUN OF THE HIGH RESOLUTION WRFARL AND HRRR MODELS DOING A VERY
GOOD JOB OF DEPICTING THE MOVEMENT...TIMING...AND AREAL COVERAGE
OF LINEAR SCATTERED CONVECTION IN THE VICINITY OF THE FRONT...WITH
MORE STRATIFORM AREA OF PRECIPITATION ADVANCING NORTHEAST THROUGH
THE SOUTHERN COUNTIES WHERE ISENTROPIC LIFT IS MAXIMIZED.
EXPECT TO SEE SOUTHERN STRATIFORM AREA OF PRECIPITATION MAINLY
SOUTH OF HIGHWAY 460 TO MOVE EAST OF THE BLACKSBURG FORECAST AREA
BY MID MORNING AS BEST ISENTROPIC LIFT MOVES EAST OF REGION...AND
AS LOWER TROPOSPHERIC WINDS GRADUALLY VEER INTO MORE OF A
DOWNSLOPING COMPONENT AS SURFACE LOW PRESSURE MOVES EAST TO THE
DELMARVA AREA.
MEANWHILE...FURTHER NW NEAR THE SURFACE FRONT...PAST SEVERAL HOURS
OF SATELLITE PICTURES AND SURFACE OBSERVATIONS SHOWING A MARKED
DECREASE OF CONVECTIVE ACTIVITY ALONG/NEAR FRONT DUE TO LIMITED
FORCING AND NEGLIGIBLE THERMODYNAMIC SUPPORT. SOME STRAY
SHOWERS/ISOLATED STORMS MAY REACH THE WESTERN TIER COUNTIES
SHORTLY BEFORE/AROUND DAYBREAK...SUPPORTED BY AT LEAST SOME
LIMITED UPSLOPING ALONG THE WESTERN FLANKS OF THE
APPALACHIANS...BUT ANY REIGNITING ALONG THE FRONT WILL LIKELY COME
LATER IN THE AFTERNOON AFTER THERMODYNAMIC SUPPORT INCREASES...AND
BY THEN...FRONT/SURFACE TROF LIKELY TO SOUTH AND EAST OF THE
BLACKSBURG FORECAST AREA.
DESPITE ARRIVAL AND PASSAGE OF FRONT AND ASSOCIATED CLOUDS...LITTLE
CHANGE IN AIR MASS IS EXPECTED DURING THE DAY SINCE DEEPER COOL
AIR LAGS WELL BEHIND WIND SHIFT. COMBINATION OF LINGERING CLOUDS
IN UPSLOPE AREAS OF THE WEST AND AT LEAST A FEW DEGREE REDUCTION
IN 850 MILLIBAR TEMPERATURE SHOULD PREVENT AFTERNOON READINGS
FROM REACHING THOSE EXPERIENCED ON FRIDAY. HOWEVER...DOWNSLOPING
WINDS FOLLOWING PASSAGE OF FRONT/TROF MAY VERY WELL ALLOW FOR A WARMER
DAY ACROSS MUCH OF THE PIEDMONT. ALL AND ALL...EXPECT TEMPERATURES
TO CONTINUE TO BE 10-15 DEGREES ABOVE NORMAL FOR THE LAST DAY OF
THE MONTH...GENERALLY 60S ACROSS THE WESTERN MOUNTAINS TO NEAR 80
ACROSS THE PIEDMONT. THIS WILL ENSURE THAT MOST CLIMATOLOGICAL
SITES END UP BREAKING OR BEING IN THE TOP SEVERAL WARMEST MARCHES
ON RECORD.
DRY SURFACE RIDGE OF HIGH PRESSURE BUILDING IN FROM THE NORTH AND
WEST TONIGHT SHOULD ALLOW FOR CLEARING SKIES WITH GOOD RADIATIVE
COOLING POTENTIAL. READINGS SHORTLY BEFORE DAYBREAK ON SUNDAY
EXPECTED TO RANGE FROM THE MID 30S TO LOWER 40S IN THE
MOUNTAINS...WHERE SOME PATCHY FROST MAY OCCUR IN SOME OF THE
DEEPER MOUNTAIN VALLEYS...TO THE MID AND UPPER 40S ACROSS THE
PIEDMONT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM EDT SATURDAY...
ON SUNDAY...WE ARE EXPECTING HIGH PRESSURE TO SETTLE OVER THE AREA
BY THE MORNING. A STRONGER NOSE OF HIGH PRESSURE IS EXPECTED TO HEAD
SOUTH THROUGH THE GREAT LAKES AREA LATER IN THE DAY. THIS FEATURE
MAY PROMPT A BACK DOOR COLD FRONT INTO THE AREA...WITH THE POTENTIAL
FOR SOME ISOLATED SHOWERS ALONG IT LATE IN THE AFTERNOON INTO SUNDAY
EVENING. AS THE BACK DOOR FRONT CONTINUES SOUTH THROUGH THE AREA
SUNDAY NIGHT...ANTICIPATE ISOLATED COVERAGE ACROSS
WESTERN...NORTHERN...AND EASTERN SECTIONS OF THE REGION. COVERAGE
MAY SCATTERED OVER SECTIONS OF SOUTHEAST WEST VIRGINIA.
THIS FRONT WILL BECOME STALLED OVER THE WESTERN THIRD OF THE AREA BY
MONDAY MORNING. DURING THE DAY MONDAY...AN AREA OF LOW PRESSURE WILL
BE MOVING EASTWARD THROUGH THE CENTRAL PART OF THE U.S. WIND FLOW
IN ADVANCE OF THIS FEATURE WILL TURN SOUTHERLY ACROSS THE WESTERN
GULF OF MEXICO...AND ADVECT INTO OUR REGION FROM THE SOUTHWEST. THE
RESULT WILL BE INCREASING COVERAGE OF SHOWERS ALONG THE STALLED
FRONT THANKS TO THE INCREASED MOISTURE. THE FRONT ITSELF WILL ALSO
TAKE ON MORE OF THE NATURE OF A WARM FRONT AND HEAD ACROSS THE AREA
BY MONDAY NIGHT.
ON TUESDAY...THE LOW WILL HEAD EASTWARD NEAR THE PA/MD LINE AND ITS
ASSOCIATED COLD FRONT WILL SWEEP THROUGH THE AREA. WE ARE
ANTICIPATING INCREASED CHANCES OF SHOWERS AND THUNDERSTORMS DURING
THE DAY...ESPECIALLY ACROSS THE MOUNTAINS. AREAS ALONG AND EAST OF A
FARMVILLE TO DANVILLE LINE MAY NOT SEE ANY ACTIVITY UNTIL TUESDAY
EVENING. BY TUESDAY NIGHT... MOST OF THE PRECIPITATION WILL BE SOUTH
OF THE AREA IN ASSOCIATION WITH THE COLD FRONT. LINGERING SHOWERS
WILL STILL BE POSSIBLE ACROSS THE AREA...ESPECIALLY OVER SOUTHEAST
WV WHERE NORTHWEST FLOW UPSLOPE SHOWERS ARE EXPECTED.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
WITH THE COLD FRONT PASSING THROUGH OUR AREA ON TUESDAY NIGHT AND
WEDNESDAY MORNING...EXPECT ANOTHER LARGE DOME OF CANADIAN HIGH
PRESSURE TO BUILD INTO THE UPPER MIDWEST...BRINGING OUR TEMPERATURES
MUCH CLOSER TO NORMAL FOR THE FIRST WEEK OF APRIL. WITH HIGH
PRESSURE MAINTAINING ITS CONTROL THROUGH THE BEGINNING OF NEXT
WEEKEND...THE ONLY WEATHER CONCERNS WILL BE CHILLY OVERNIGHT
TEMPERATURES...WHICH MAY APPROACH FREEZING ACROSS PARTS OF SOUTHEAST
WEST VIRGINIA...AND MAY RESULT IN OVERNIGHT FROST ELSEWHERE ACROSS
THE MOUNTAINS.
&&
.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
AS OF 735 AM EDT SATURDAY...
COOL FRONT WILL SWEEP SOUTHEAST THROUGH THE SOUTHEASTERN WV
TERMINAL FORECAST POINTS THIS MORNING...AND MOVE EAST OF THE
PIEDMONT TERMINAL FORECAST POINTS BY EARLY TO MID AFTERNOON.
UPSLOPING WINDS ACROSS THE WESTERN FLANKS OF THE APPALACHIANS WILL
RESULT IN AREAS OF MVFR FLIGHT RESTRICTIONS...WITH LOCALIZED IFR
CONDITIONS ALONG WITH MOUNTAIN TOP OBSCURATIONS INTO MID MORNING...
ESPECIALLY SOUTH OF BLUEFIELD INTO THE NW NC MOUNTAINS...WHERE
RAIN FELL OVERNIGHT. ELSEWHERE...VEERING WINDS IN LOWER TROPOSPHERE
AS LOW PRESSURE MOVES EAST AND OFF DELMARVA COASTLINE WILL RESULT
IN DEVELOPMENT OF DOWNSLOPING WINDS EAST OF THE BLUE RIDGE...
ENSURING THAT MAINLY VFR CONDITIONS PREVAIL IN THIS AREA DESPITE
SOME SHOWERS INTO MID MORNING SOUTH OF HIGHWAY 460.
SURFACE RIDGE OF HIGH PRESSURE BUILDING SOUTHEAST INTO THE MID
APPALACHIAN AND MID ATLANTIC REGION...AND ARRIVAL OF DRIER AIR
THIS AFTERNOON INTO SUNDAY SHOULD ENSURE CLEARING CONDITIONS WITH
VFR WEATHER TO RETURN TO EVEN THE WESTERN UPSLOPE AREAS BY EARLY
TO MID AFTERNOON.
THE NEXT THREAT FOR WIDESPREAD FLIGHT RESTRICTIONS WILL OCCUR
LATE SUNDAY NIGHT OR ON MONDAY...POSSIBLY CONTINUING INTO THE MID
WEEK PERIOD AS ANOTHER RIDGE OF HIGH PRESSURE BUILDS SOUTHWEST OUT
OF NEW ENGLAND. UPSLOPING WINDS ACROSS THE EASTERN FLANKS OF THE
BLUE RIDGE...WITH WEAK SHORT WAVES AND MOISTURE STREAMING
NORTHEAST OVER A STALLED FRONT OVER/NEAR THE AREA...MAY SET THE
STAGE FOR MVFR (AND POTENTIALLY LOWER) FLIGHT RESTRICTIONS INTO
THE MID WEEK PERIOD...ESPECIALLY OVER/IN THE MOUNTAINS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WERT
NEAR TERM...WERT
SHORT TERM...DS
LONG TERM...NF
AVIATION...WERT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
605 AM CDT SAT MAR 31 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
315 AM CDT SAT MAR 31 2012
MAIN FORECAST CONCERNS ARE ON CONVECTION CHANCES TONIGHT THROUGH
MONDAY NIGHT AS WELL AS TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED A POTENT SHORTWAVE TROUGH OFF THE CALIFORNIA COASTLINE BY
ABOUT 500 MILES...RIDGING BUILDING DOWNSTREAM FROM THE FOUR CORNERS
REGION INTO WYOMING AND SOUTH DAKOTA...AND A WEAK SHORTWAVE OVER
EASTERN IOWA. CONDITIONS ARE DRY OVER THE FORECAST AREA NOW BEING IN
THE WAKE OF THE WEAK SHORTWAVE...PLUS PLENTY OF DRY AIR EXISTS ABOVE
850MB...NOTED ON THE 00Z MPX AND GRB SOUNDINGS. HOWEVER...A LOW
STRATUS DECK OF CLOUDS PERSISTS FROM MICHIGAN WESTWARD TO I-35...
RESULTING FROM MOISTURE TRAPPED BELOW A SUBSIDENCE INVERSION. THIS
IS ALSO SEEN ON THE AFOREMENTIONED SOUNDINGS. A SURFACE RIDGE OF
HIGH PRESSURE THAT STRETCHED FROM HUDSON BAY THROUGH SOUTHERN
WISCONSIN IS ALSO HELPING TO PROVIDE A COOL FLOW OF AIR...THUS NOT
ALLOWING THE STRATUS DECK TO DISSIPATE. TO THE WEST...MUCH WARMER
AIR WAS PRESENT UNDER THE BUILDING RIDGING OVER THE NORTHERN PLAINS.
850MB TEMPS CLIMB FROM -1C AT GRB TO 7C AT MPX...10C AT ABR AND 19C
AT UNR. THIS WARM AIR HAS BEEN SLOWLY PUSHING EAST AHEAD OF A LEE
TROUGH OVER THE WESTERN DAKOTAS...WITH 850MB PROFILER DATA SHOWING
SOUTHWEST WINDS OF 10-25 KT FROM THE PLAINS TO NEAR I-35 IN MN AND
IOWA. SO FAR ONLY HIGH BASED ALTOSTRATUS AND CIRRUS WERE PRESENT
WITH THE WARM ADVECTION.
TODAY AND TONIGHT...AS THE UPPER TROUGHING OFF THE COAST OF
CALIFORNIA PLOWS INTO THE WEST COAST...UPPER RIDGING LOOKS TO
FURTHER BUILD/STRENGTHEN DOWNSTREAM OVER THE PLAINS. AS A RESULT...
THE UPPER FLOW OVER THE FORECAST AREA STAYS NORTHWESTERLY THROUGH
TONIGHT. DESPITE THE NORTHWEST FLOW AT 500MB...LOWER LEVELS SUCH AS
850MB DEPICT A WARM ADVECTION PATTERN...WHICH ALLOWS THE CURRENT
SURFACE RIDGE TO MOVE OFF TO THE EAST. THE COMBINATION OF THE RIDGE
PUSHING EAST TODAY AND DAYTIME HEATING WILL ALLOW THE LOW CLOUDS TO
MIX/CLEAR OUT. SHOULD STILL SEE SOME HIGH BASED MID/HIGH CLOUD COVER
LIKE IS BEING OBSERVED OVER THE DAKOTAS NOW. SO OVERALL...A CLOUDY
BECOMING PARTLY SUNNY DAY. 925MB TEMPS CLIMB THROUGH THE DAY...
TOPPING OUT FROM 8C EAST TO 14C WEST BY 00Z. SOUNDINGS SUGGEST EASY
MIXING TO THIS LEVEL AND LIKELY UP TO 900MB...SUPPORTING HIGHS FROM
THE MID 50S EAST TO MID/UPPER 60S WEST. FOR TONIGHT...A WARM FRONT
OVER SOUTHWEST IOWA AT 00Z LOOKS LIKE IT WILL LIFT INTO NORTHEAST
IOWA BY 12Z. ISENTROPIC LIFT SEEN ON 300-305K SURFACES OVER THIS
FRONT COULD SUPPORT SOME CONVECTION SOUTH OF I-90. A SURGE OF
850MB DEWPOINTS OF 8-10C AND TEMPS AROUND 16C ACCOMPANY THE
ISENTROPIC LIFT...RESULTING IN ELEVATED CAPE VALUES OF 500 TO
PERHAPS AS HIGH AS 1000 J/KG IF THE 31.00Z NAM IS CORRECT. 1-6 KM
SHEAR VALUES OF 30-40 KT EXIST WHICH WOULD SUPPORT ORGANIZED
CONVECTION WITH LARGE HAIL BEING THE MAIN HAZARD. SINCE GOOD
CONSENSUS CONTINUES FOR THIS PRECIPITATION SOUTH OF I-90...RAISED
PRECIPITATION CHANCES UP ANOTHER 10 PERCENT. ONE THING TO WATCH
FOR IS THAT THE ECMWF REMAINS EVEN A LITTLE FARTHER SOUTH WITH THE
CONVECTION. WITH SCT-BKN MID/HIGH CLOUDS THROUGHOUT MUCH OF THE
NIGHT AND A GENERAL WARM ADVECTION PATTERN IN PLACE...ANTICIPATING
A MUCH WARMER NIGHT TONIGHT. FOLLOW A BLEND OF GUIDANCE FOR LOWS.
SUNDAY INTO SUNDAY NIGHT...THE WEST COAST TROUGH IS PROGGED TO PUSH
EAST IT NO THE ROCKIES...PERHAPS BEGINNING TO SPLIT INTO TWO PIECES
BY 12Z MONDAY AS IT RUNS INTO THE STRONGER RIDGING DOWNSTREAM. THIS
RIDGING SHOULD ENVELOP MUCH OF THE FORECAST AREA SUNDAY NIGHT.
ANTICIPATING THE SUBSIDENCE UNDER THIS UPPER RIDGE WILL BE ENOUGH TO
KEEP THE MAJORITY OF THE FORECAST AREA DRY DURING THIS PERIOD.
HOWEVER...THERE HAS BEEN A SIGNAL FOR A FRONTOGENESIS BAND OF
SHOWERS AND EMBEDDED THUNDERSTORMS TO DEVELOP SUNDAY NIGHT...FROM
NORTHERN MN INTO NORTHWEST WISCONSIN AND SOUTHEAST TO THE GREEN BAY
AREA. THIS IS MOST PREVALENT IN THE 31.00Z NAM...WHERE THE 31.00Z
GFS/UKMET/CANADIAN KEEP IT CONFINED MORE TO NORTHERN MN AND
NORTHWEST WISCONSIN. 31.00Z ECMWF IS COMPLETELY DRY. HAVE STAYED
TOWARDS THE DRIER SCENARIOS SEEING THE STRENGTH OF THE UPPER
RIDGE...BUT JUST IN CASE CONVECTION OCCURS IN NORTHWEST WISCONSIN
DID PLACE A 20 PERCENT CHANCE OVER TAYLOR COUNTY. OTHERWISE...
TEMPERATURES ARE THE MAIN CONCERN. THAT WARM FRONT LIFTING UP
TONIGHT LOOKS TO GET STUCK NEAR OR JUST SOUTH OF THE FORECAST
AREA...DUE TO THE NORTHWEST FLOW ALOFT AHEAD OF THE UPPER RIDGE
AXIS. STILL...925MB TEMPS CLIMB TO 14C EAST TO 20-22C WEST. THESE
READINGS SUGGEST A WIDE RANGE OF HIGHS...LIKELY FROM THE UPPER 60S
SAY IN MEDFORD TO NEAR WISCONSIN RAPIDS...TO LOW OR PERHAPS EVEN MID
80S FROM CHARLES CITY IA TO AUSTIN MN. WARM NIGHT LIKELY ON TAP
SUNDAY NIGHT GIVEN THE WARM START AND A PERSISTENT EAST TO SOUTHEAST
BREEZE.
MONDAY AND MONDAY NIGHT...VERY GOOD AGREEMENT EXISTS THAT THE
WESTERN UPPER TROUGH SPLITS WITH THE SOUTHERN PORTION CUTTING OFF
INTO AN UPPER LOW OVER NEW MEXICO. MEANWHILE...THE NORTHERN PORTION
ENDS UP TRACKING WELL TO OUR NORTH...MOVING INTO NORTHWEST ONTARIO
BY 12Z TUESDAY. THIS PUTS SOME QUESTION MARKS INTO FORCING FOR
PRECIPITATION. THE UPPER RIDGE THAT WAS OVER THE AREA AT 12Z MONDAY
WILL BREAK DOWN WITH THE APPROACH OF THE NORTHERN TROUGH FEATURE...
WHICH SHOULD HELP. ALSO...AT THE SURFACE...A TROUGH/COLD FRONT LOOKS
TO CROSS THE AREA TO PROVIDE SURFACE CONVERGENCE. HOWEVER...THE
TIMING OF THIS SURFACE FEATURE IS FAR FROM CERTAIN...WITH THE 31.00Z
ECMWF/CANADIAN/UKMET POSITION OVER WESTERN MINNESOTA COMPARED TO
CENTRAL/EASTERN WISCONSIN FROM THE 31.00Z GFS/NAM. THE LATTER
SOLUTIONS PRODUCE SOME SHOWER AND THUNDERSTORM ACTIVITY ON MONDAY
INTO MONDAY EVENING...WHICH MAKES SENSE GIVEN THE TIMING DURING PEAK
HEATING. MEANWHILE...THE ECMWF/CANADIAN/UKMET WAIT UNTIL MONDAY
NIGHT. LEANED A LITTLE MORE TOWARD THE ECMWF/CANADIAN/UKMET
GROUP...KEEPING CHANCES ONLY AT 20-30 FOR MONDAY AND 30-50 FOR
MONDAY NIGHT. IN ADDITION...TEMPERATURES FOR MONDAY ARE EXTREMELY
TRICKY DEPENDING ON THE FRONTAL TIMING. FOR NOW STAYED WITH A
CONSENSUS BLEND...BUT IF THE ECMWF IS RIGHT...MONDAY COULD LOOKS
JUST LIKE SUNDAY AND BE A FEW DEGREES WARMER. NEEDLESS TO SAY...A
LOT OF UNCERTAINTY.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
315 AM CDT SAT MAR 31 2012
QUIET WEATHER LOOKS TO DOMINATE THE ENTIRE LONG TERM PERIOD. A
CANADIAN HIGH PRESSURE RIDGE IS PROGGED BY THE 31.00Z
ECMWF/GFS/CANADIAN/UKMET TO BUILD INTO THE FORECAST AREA
TUESDAY...BEHIND MONDAY NIGHTS COLD FRONT...THEN ONLY DRIFT OFF TO
THE EAST THROUGH FRIDAY NIGHT. MEANWHILE...UPPER RIDGING LOOKS TO
BUILD ALOFT AHEAD OF DEEP TROUGHING DEVELOPING OVER THE WESTERN U.S.
THROUGH THE LONG TERM PERIOD. THIS SETUP FAVORS DRY CONDITIONS.
NOTE...THE 31.00Z GFS TRIES TO BRING THE CUT-OFF UPPER LOW IN NEW
MEXICO MONDAY NIGHT INTO IOWA BY 12Z THURSDAY...RESULTING IN SOME
SHOWERS OVER THE FORECAST AREA. THIS MODEL IS AN OUTLIER...EVEN
COMPARED TO ITS PREVIOUS RUN AND MOST OF ITS ENSEMBLE MEMBERS...AND
THEREFORE IGNORED AT THIS TIME. 850MB TEMPS WILL SLOWLY COOL...
DROPPING TO 2-4C FOR BOTH WEDNESDAY AND THURSDAY...BEFORE CLIMBING
BACK UP TO 4-6C ON FRIDAY AS THE SURFACE RIDGE MOVES EAST.
STILL...PLENTY OF SUN IS EXPECTED WHICH SHOULD HELP KEEP HIGHS ABOVE
NORMAL. CERTAINLY POSSIBLE TO SEE SOME FROST AT TIMES...ESPECIALLY
OVER CENTRAL WISCONSIN. IN ADDITION...MAY HAVE TO KEEP AN EYE ON
RELATIVE HUMIDITIES GIVEN WHAT LOOKS TO BE A BRIEF HUDSON BAY HIGH
SCENARIO...KNOWN TO MIX DEWPOINTS LOWER THAN FORECAST. HOWEVER...
WITH GREEN-UP WELL UNDERWAY...EVAPOTRANSPIRATION COULD KEEP
DEWPOINTS HIGHER MORE THAN WHAT WOULD NORMALLY OCCUR WITH A HUDSON
BAY HIGH.
&&
.AVIATION...TODAY AND TONIGHT
605 AM CDT SAT MAR 31 2012
LOW STRATUS WILL PERIST AT THE TAF SITES THROUGH MID MORNING
PRODUCING CEILINGS IN THE 200 TO 700 FT RANGE AT KRST...AND IN THE
800 TO 1100 FT RANGE AT KLSE. IN ADDITION...VISIBLITIES WILL BE
REDUCED INTO THE 2 TO 3 SM RANGE AT KRST THROUGH 14Z. LOOK FOR
CONDITIONS TO GRADUALLY IMPROVE TO MVFR IN THE 14 TO 16 Z
TIMEFRAME AS THE STRATUS STARTS TO BREAK UP. CLOUD BASES WILL RISE
TO AROUND 1500 FT LATE THIS MORNING...BECOMING SCATTERED BY EARLY
THIS AFTERNOON. PLAN ON SOUTHEAST WINDS OF 6 TO 10 KTS THROUGH THE
DAY. A WARM FRONT WILL LIFT INTO NORTHERN IOWA AND SOUTHWEST
WISCONSIN THIS EVENING AND WILL BE THE FOCUS FOR SHOWER AND
THUNDERSTORM DEVELOPMENT. THE STRONGEST 850 MB MOISTURE TRANSPORT
WILL OCCUR ACROSS NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN. THE
SHOWERS AND THUNDERSTORMS SHOULD STAY SOUTH OF THE TAF SITES LATE
THIS EVENING INTO THE OVERNIGHT HOURS WITH VFR CONDITIONS
EXPECTED. WILL HAVE TO KEEP A CLOSE WATCH ON THE PROGRESSION OF
THE WARM FROM LATE THIS AFTERNOON INTO EARLY THIS EVENING. IF
THUNDERSTORMS DEVELOP...A FEW STORMS WILL BE CAPABLE OF PRODUCING
LARGE HAIL AND BRIEF HEAVY RAINFALL. LATEST GUIDANCE IS SUGGESTING
FOG DEVELOPMENT LATE TONIGHT INTO EARLY SUNDAY MORNING...MAINLY
ALONG AND NORTH OF THE WARM FRONT. CURRENT THINKING IS THAT THE
WINDS NEAR THE SURFACE WILL PROVIDE ENOUGH MIXING TO INHIBIT FOG
DEVELOPMENT. IF THE WARM FRONT ADVANCES FURTHER NORTH LATE
TONIGHT...AND DECOUPLING OCCURS...FOG COULD IMPACT THE TAF SITES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
315 AM CDT SAT MAR 31 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION...CORRECTION...
NWS DENVER/BOULDER CO
1052 AM MDT SAT MAR 31 2012
...CORRECTED TO ADD HIGHLIGHTS BELOW...
.UPDATE...CURRENT FORECASTS LOOK ON TRACK. LATEST RUC AS WELL AS
HRRR RUNS CONTINUE TO SUPPORT RED FLAG CONDITIONS ACROSS THE
FOOTHILLS OF SOUTHERN JEFFERSON AND DOUGLAS COUNTIES AS WELL AS
THE PALMER DIVIDE AND SOUTH PARK FOR THIS AFTERNOON AND EVENING.
BELIEVE THERE WILL BE ENOUGH MIXING TO GET GUSTS TO 30 MPH IN
THAT AREA. LOWER NORTH FORK FIRE AREA SHOULD SEE SOUTHERLY WINDS
IN THE 10-20 MPH RANGE PRIMARILY...ALONG WITH A FEW GUSTS TO
30 MPH. STILL SOME QUESTION WHETHER GUSTY WINDS WILL SPREAD
FURTHER NORTH ACROSS THE PLAINS. DESPITE MIXING...FEEL WINDS
SHOULD STAY BELOW CRITERIA. AS FOR TEMPERATURES...RECORD FOR
DENVER SHOULD BE BROKEN DESPITE HIGH LEVEL CLOUDS. AS FOR FIRE
WEATHER WATCH SUNDAY...LATEST GUIDANCE STILL SUGGESTING MARGINAL
CONDITIONS. HOWEVER...DESPITE COOLING IT LOOKS LIKE INCREASING
GRADIENT WILL BE ENOUGH FOR AN UPGRADE TO A WARNING. WILL LOOK
FURTHER INTO THIS SCENARIO LATER. DON`T THINK THAT AREA WILL NEED
TO BE EXPANDED.
&&
.AVIATION...CURRENT TAFS LOOKING ON TRACK. GUIDANCE STILL SHOWING
WINDS BECOMING MORE SOUTHEAST ACROSS THE AREA AIRPORTS THIS
AFTERNOON. LATEST RUC INDICATING A BIT MORE WIND...WILL INCREASE
THE SPEEDS A BIT AT APA AND DEN.
&&
.PREV DISCUSSION... /ISSUED 436 AM MDT SAT MAR 31 2012/
..CORRECTION TO THIRD PARAGRAPH...
SHORT TERM...NORTHWEST FLOW ALOFT TO SHIFT TO THE SOUTHWEST
TONIGHT AS AN UPPER LEVEL RIDGE PASSES OVER COLORADO. THIS RIDGE
WILL BRING VERY WARM TEMPERATURES FOR THIS TIME OF YEAR. AIRMASS
WILL BE ABOUT 5 DEGREES FAHRENHEIT WARMER THAN YESTERDAY. THIS
WILL PUT MOST LOCATIONS OVER NORTHEAST COLORADO IN THE UPPER 70S
TO MID 80S. THE RECORD FOR TODAY AT THE DENVER AIRPORT IS 80
DEGREES AND HAS A GOOD CHANCE OF BEING SURPASSED. HIGH CLOUDS WILL
MOVE OVER THE STATE AT TIMES TODAY. DOES NOT APPEAR THERE WILL BE
ENOUGH CLOUD TO AFFECT TEMPERATURES MUCH TODAY.
FIRE WEATHER...THE VERY WARM AND DRY CONDITIONS WILL KEEP
FUELS VERY DRY. MOST LOCATIONS WILL SEE RELATIVE HUMIDITIES BELOW
15 PERCENT TODAY. WINDS WILL BECOME BREEZY THIS AFTERNOON ACROSS
PARTS OF THE AREA. SOUNDINGS ACROSS THE AREA SHOW PEAK WINDS OF
20-30 KNOTS IN THE MIX LAYER THIS AFTERNOON. SO MAY SEE SOME GUST
OF 25-35 MPH MIX DOWN OVER PARTS OF THE HIGH COUNTRY AND EASTERN
PLAINS. A RED FLAG WARNING IS IN EFFECT FOR PARK COUNTY...THE
SOUTHERN FOOTHILLS AND THE PALMER DIVIDE. THE STRONGER WINDS LOOK
TO BE OVER PARK COUNTY AND SOUTHERN PARTS OF JEFFERSON AND
DOUGLAS COUNTIES WHERE GUSTS TO 30 MPH WILL BE POSSIBLE FOR A FEW
HOURS THIS AFTERNOON. WINDS WILL BE NOTHING LIKE THEY WERE THIS
PAST MONDAY WHEN THE LOWER NORTH FORK FIRE ROARED ACROSS THE
FOOTHILLS. THE WINDS ACROSS THE LOWER NORTH FORK FIRE THIS
AFTERNOON ARE EXPECTED TO BE 10 TO 20 MPH WITH A FEW GUSTS UP TO
30 MPH POSSIBLE. WILL NOT EXPAND THE RED FLAG WARNING FOR TODAY
BECAUSE THE WINDS WILL HARD TIME STAYING ABOVE THE 25 MPH
THRESHOLD FOR 3 HOURS.
LONG TERM...ONE MORE DAY OF UNSEASONABLY WARM AND DRY CONDITIONS
ESPLY EAST OF THE MTNS ON SUNDAY. MODELS CONTINUE TO EVOLVE THE
UPPER TROUGH TO OUR WEST ON SUNDAY. PAST FEW DAYS...ALL SORTS OF
SOLUTIONS HAVE COME FORTH...ALTHOUGH THE PAST FEW ITERATIONS HAVE
CONVERGED ON THE IDEA OF A DEEP TROUGH WITH A CLOSED LOW NEAR THE
FOUR CORNERS SUNDAY NIGHT. ON SUNDAY SOUTHWESTERLY FLOW ALOFT
STRENGTHENS THROUGH THE DAY AS THE PRESSURE GRADIENT ON THE PLAINS
TIGHTENS WITH PRESSURE AND HEIGHT FALLS WEST OF THE MTNS. AT PRESENT
TIME...A FIRE WEATHER WATCH IS OUT FOR THE SOUTHEAST QUADRANT OF THE
FORECAST AREA...SPECIFICALLY FOR THE SOUTHERN FOOTHILLS WEST OF
DENVER...DOUGLAS AND ELBERT COUNTIES...EASTERN PORTIONS OF ADAMS AND
ARAPAHOE COUNTIES...AND WASHINGTON COUNTY...AS WELL AS NORTH...
MIDDLE AND SOUTH PARKS. LATEST MODEL GUIDANCE WOULD SUPPORT THIS
AREA BEING UNDER A WATCH...ALTHOUGH WIND SPEEDS SUNDAY AFTERNOON
ONLY MARGINALLY STRONG ENOUGH. FOR NOW MUST CONSIDER LATER GUIDANCE
BEFORE UPGRADING THE WATCH TO A WARNING. OTHERWISE HIGHS ON SUNDAY
SLIGHTLY COOLER...OR LESS WARM THAN ON SATURDAY WITH MID 70S TO
LOWER 80S ON THE PLAINS. SHOULD HIGH CLOUD SHIELD THICKEN UP SOONER
THAN EXPECTED...MAY NOT GET INTO THE 80S. RECORD HIGH AT DENVER ON
SUNDAY IS 78. SHOULD COME CLOSE IF NOT EXCEED IT.
OVERNIGHT SUNDAY...AS THE UPPER TROUGH SHIFTS OVER WESTERN
COLORADO...MODELS SHOW A STRONG COLD FRONT SURGING SOUTH ALONG THE
FRONT RANGE PUSHED ALONG BY 25 TO 40 MPH NORTHERLY WINDS. BOUNDARY
LAYER STARTS OUT VERY DRY THAT EVENING BUT QUICKLY MOISTENS ESPLY
ALONG THE FOOTHILLS AFTER MIDNIGHT. MODELS INDICATE A GOOD DEAL OF
MID AND UPPER LEVEL QG ASCENT WITH THE SOUTHERN END OF THIS
TROUGH. HOWEVER MOST OF THIS ASCENT PASSES TO THE SOUTH OF THE
FORECAST AREA DURING THE DAY MONDAY. NEVERTHELESS...NORTH-
NORTHEASTERLY LOW LEVEL FLOW AND MODERATELY STRONG QG ASCENT
SHOULD BE SUFFICIENT TO PRODUCE SNOW SHOWERS IN THE N-CENTRAL MTNS
AND FRONT RANGE FOOTHILLS...AND SCATTERED RAIN SHOWERS AT LOWER
ELEVATIONS BY DAYLIGHT MONDAY. PRECIP UP AGAINST THE FOOTHILLS AND
OVER THE PALMER DIVIDE COULD CHANGE TO A MIX OF RAIN AND SNOW
BEFORE MORNING WITH THE MERCURY DIPPING TO THE LOWER 30S. HOWEVER
DO NOT EXPECT TO SEE ANY SNOW ACCUMULATION AS GROUND TEMPS WILL
REMAIN QUITE WARM. ANY SNOW AT LOWER ELEVATIONS SHOULD REVERT TO
ALL RAIN BY LATE MORNING WITH WARMING TEMPS...ONLY TO CHANGE BACK
TO A MIX OF RAIN AND SNOW TOWARDS EVENING. MODEL GUIDANCE
INDICATES UP TO AN INCH OR TWO OF WET SNOW OVER HIGHER AREAS JUST
SOUTH OF DENVER BY LATE THIS EVENING. AGAIN WITH THE GROUND AS
WARM AS IT IS...MUCH OF THIS SNOW SHOULD MELT SOON AFTER FALLING.
HIGHER AREAS IN THE FOOTHILLS...SAY ABOVE 7000 FEET...COULD SEE
SOME LIGHT SNOW ACCUMULATION ON THE ORDER OF 1 TO 4 INCHES BY
MONDAY EVENING...WITH SIMILAR TOTALS OVER THE HIGHER MTNS RIDGES
AND PASSES. THIS SYSTEM DOES NOT LOOK LIKE A BIG PRECIP PRODUCER
FOR US..BUT WE/LL TAKE WHAT WE CAN GET.
ON TUESDAY...MODELS SLOW TO MOVE OUT THIS TROUGH. SOME ACTUALLY
SHOW THIS SYSTEM WOBBLING BACK OVER EASTERN COLORADO DURING THE
DAY WHICH WOULD KEEP THE AREA UNDER CLOUDS AND COOL TEMPS AND
POSSIBLY KEEP A FEW SHOWERS AROUND. BY WEDNESDAY AND BEYOND
HIGH PRESSURE MOVES IN FROM THE WEST RESULTING IN A QUICK WARMUP
AND A RETURN TO DRY CONDITIONS AND PLENTY OF SUNSHINE AREAWIDE.
AVIATION...WINDS WILL REMAIN SOUTHERLY THROUGH TODAY AND TONIGHT.
MAY SEE SOME GUSTS TO 20 KNOTS THIS AFTERNOON AS STRONGER WINDS
ALOFT MIX DOWN. WILL SEE PERIODS OF HIGH CLOUDS THROUGH THE 24
HOURS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...RED FLAG WARNING FROM NOON TO 8
PM MDT SATURDAY FOR COZ214-216-241.
FIRE WEATHER WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING FOR
COZ211-213-214-216-241-245>247-249.
&&
$$
SHORT TERM...D-L
LONG TERM....BAKER
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1018 AM MDT SAT MAR 31 2012
.UPDATE...CURRENT FORECASTS LOOK ON TRACK. LATEST RUC AS WELL AS
HRRR RUNS CONTINUE TO SUPPORT RED FLAG CONDITIONS ACROSS THE
FOOTHILLS OF SOUTHERN JEFFERSON AND DOUGLAS COUNTIES AS WELL AS
THE PALMER DIVIDE AND SOUTH PARK FOR THIS AFTERNOON AND EVENING.
BELIEVE THERE WILL BE ENOUGH MIXING TO GET GUSTS TO 30 MPH IN
THAT AREA. LOWER NORTH FORK FIRE AREA SHOULD SEE SOUTHERLY WINDS
IN THE 10-20 MPH RANGE PRIMARILY...ALONG WITH A FEW GUSTS TO
30 MPH. STILL SOME QUESTION WHETHER GUSTY WINDS WILL SPREAD
FURTHER NORTH ACROSS THE PLAINS. DESPITE MIXING...FEEL WINDS
SHOULD STAY BELOW CRITERIA. AS FOR TEMPERATURES...RECORD FOR
DENVER SHOULD BE BROKEN DESPITE HIGH LEVEL CLOUDS. AS FOR FIRE
WEATHER WATCH SUNDAY...LATEST GUIDANCE STILL SUGGESTING MARGINAL
CONDITIONS. HOWEVER...DESPITE COOLING IT LOOKS LIKE INCREASING
GRADIENT WILL BE ENOUGH FOR AN UPGRADE TO A WARNING. WILL LOOK
FURTHER INTO THIS SCENARIO LATER. DON`T THINK THAT AREA WILL NEED
TO BE EXPANDED.
&&
.AVIATION...CURRENT TAFS LOOKING ON TRACK. GUIDANCE STILL SHOWING
WINDS BECOMING MORE SOUTHEAST ACROSS THE AREA AIRPORTS THIS
AFTERNOON. LATEST RUC INDICATING A BIT MORE WIND...WILL INCREASE
THE SPEEDS A BIT AT APA AND DEN.
&&
.PREV DISCUSSION... /ISSUED 436 AM MDT SAT MAR 31 2012/
..CORRECTION TO THIRD PARAGRAPH...
SHORT TERM...NORTHWEST FLOW ALOFT TO SHIFT TO THE SOUTHWEST
TONIGHT AS AN UPPER LEVEL RIDGE PASSES OVER COLORADO. THIS RIDGE
WILL BRING VERY WARM TEMPERATURES FOR THIS TIME OF YEAR. AIRMASS
WILL BE ABOUT 5 DEGREES FAHRENHEIT WARMER THAN YESTERDAY. THIS
WILL PUT MOST LOCATIONS OVER NORTHEAST COLORADO IN THE UPPER 70S
TO MID 80S. THE RECORD FOR TODAY AT THE DENVER AIRPORT IS 80
DEGREES AND HAS A GOOD CHANCE OF BEING SURPASSED. HIGH CLOUDS WILL
MOVE OVER THE STATE AT TIMES TODAY. DOES NOT APPEAR THERE WILL BE
ENOUGH CLOUD TO AFFECT TEMPERATURES MUCH TODAY.
FIRE WEATHER...THE VERY WARM AND DRY CONDITIONS WILL KEEP
FUELS VERY DRY. MOST LOCATIONS WILL SEE RELATIVE HUMIDITIES BELOW
15 PERCENT TODAY. WINDS WILL BECOME BREEZY THIS AFTERNOON ACROSS
PARTS OF THE AREA. SOUNDINGS ACROSS THE AREA SHOW PEAK WINDS OF
20-30 KNOTS IN THE MIX LAYER THIS AFTERNOON. SO MAY SEE SOME GUST
OF 25-35 MPH MIX DOWN OVER PARTS OF THE HIGH COUNTRY AND EASTERN
PLAINS. A RED FLAG WARNING IS IN EFFECT FOR PARK COUNTY...THE
SOUTHERN FOOTHILLS AND THE PALMER DIVIDE. THE STRONGER WINDS LOOK
TO BE OVER PARK COUNTY AND SOUTHERN PARTS OF JEFFERSON AND
DOUGLAS COUNTIES WHERE GUSTS TO 30 MPH WILL BE POSSIBLE FOR A FEW
HOURS THIS AFTERNOON. WINDS WILL BE NOTHING LIKE THEY WERE THIS
PAST MONDAY WHEN THE LOWER NORTH FORK FIRE ROARED ACROSS THE
FOOTHILLS. THE WINDS ACROSS THE LOWER NORTH FORK FIRE THIS
AFTERNOON ARE EXPECTED TO BE 10 TO 20 MPH WITH A FEW GUSTS UP TO
30 MPH POSSIBLE. WILL NOT EXPAND THE RED FLAG WARNING FOR TODAY
BECAUSE THE WINDS WILL HARD TIME STAYING ABOVE THE 25 MPH
THRESHOLD FOR 3 HOURS.
LONG TERM...ONE MORE DAY OF UNSEASONABLY WARM AND DRY CONDITIONS
ESPLY EAST OF THE MTNS ON SUNDAY. MODELS CONTINUE TO EVOLVE THE
UPPER TROUGH TO OUR WEST ON SUNDAY. PAST FEW DAYS...ALL SORTS OF
SOLUTIONS HAVE COME FORTH...ALTHOUGH THE PAST FEW ITERATIONS HAVE
CONVERGED ON THE IDEA OF A DEEP TROUGH WITH A CLOSED LOW NEAR THE
FOUR CORNERS SUNDAY NIGHT. ON SUNDAY SOUTHWESTERLY FLOW ALOFT
STRENGTHENS THROUGH THE DAY AS THE PRESSURE GRADIENT ON THE PLAINS
TIGHTENS WITH PRESSURE AND HEIGHT FALLS WEST OF THE MTNS. AT PRESENT
TIME...A FIRE WEATHER WATCH IS OUT FOR THE SOUTHEAST QUADRANT OF THE
FORECAST AREA...SPECIFICALLY FOR THE SOUTHERN FOOTHILLS WEST OF
DENVER...DOUGLAS AND ELBERT COUNTIES...EASTERN PORTIONS OF ADAMS AND
ARAPAHOE COUNTIES...AND WASHINGTON COUNTY...AS WELL AS NORTH...
MIDDLE AND SOUTH PARKS. LATEST MODEL GUIDANCE WOULD SUPPORT THIS
AREA BEING UNDER A WATCH...ALTHOUGH WIND SPEEDS SUNDAY AFTERNOON
ONLY MARGINALLY STRONG ENOUGH. FOR NOW MUST CONSIDER LATER GUIDANCE
BEFORE UPGRADING THE WATCH TO A WARNING. OTHERWISE HIGHS ON SUNDAY
SLIGHTLY COOLER...OR LESS WARM THAN ON SATURDAY WITH MID 70S TO
LOWER 80S ON THE PLAINS. SHOULD HIGH CLOUD SHIELD THICKEN UP SOONER
THAN EXPECTED...MAY NOT GET INTO THE 80S. RECORD HIGH AT DENVER ON
SUNDAY IS 78. SHOULD COME CLOSE IF NOT EXCEED IT.
OVERNIGHT SUNDAY...AS THE UPPER TROUGH SHIFTS OVER WESTERN
COLORADO...MODELS SHOW A STRONG COLD FRONT SURGING SOUTH ALONG THE
FRONT RANGE PUSHED ALONG BY 25 TO 40 MPH NORTHERLY WINDS. BOUNDARY
LAYER STARTS OUT VERY DRY THAT EVENING BUT QUICKLY MOISTENS ESPLY
ALONG THE FOOTHILLS AFTER MIDNIGHT. MODELS INDICATE A GOOD DEAL OF
MID AND UPPER LEVEL QG ASCENT WITH THE SOUTHERN END OF THIS
TROUGH. HOWEVER MOST OF THIS ASCENT PASSES TO THE SOUTH OF THE
FORECAST AREA DURING THE DAY MONDAY. NEVERTHELESS...NORTH-
NORTHEASTERLY LOW LEVEL FLOW AND MODERATELY STRONG QG ASCENT
SHOULD BE SUFFICIENT TO PRODUCE SNOW SHOWERS IN THE N-CENTRAL MTNS
AND FRONT RANGE FOOTHILLS...AND SCATTERED RAIN SHOWERS AT LOWER
ELEVATIONS BY DAYLIGHT MONDAY. PRECIP UP AGAINST THE FOOTHILLS AND
OVER THE PALMER DIVIDE COULD CHANGE TO A MIX OF RAIN AND SNOW
BEFORE MORNING WITH THE MERCURY DIPPING TO THE LOWER 30S. HOWEVER
DO NOT EXPECT TO SEE ANY SNOW ACCUMULATION AS GROUND TEMPS WILL
REMAIN QUITE WARM. ANY SNOW AT LOWER ELEVATIONS SHOULD REVERT TO
ALL RAIN BY LATE MORNING WITH WARMING TEMPS...ONLY TO CHANGE BACK
TO A MIX OF RAIN AND SNOW TOWARDS EVENING. MODEL GUIDANCE
INDICATES UP TO AN INCH OR TWO OF WET SNOW OVER HIGHER AREAS JUST
SOUTH OF DENVER BY LATE THIS EVENING. AGAIN WITH THE GROUND AS
WARM AS IT IS...MUCH OF THIS SNOW SHOULD MELT SOON AFTER FALLING.
HIGHER AREAS IN THE FOOTHILLS...SAY ABOVE 7000 FEET...COULD SEE
SOME LIGHT SNOW ACCUMULATION ON THE ORDER OF 1 TO 4 INCHES BY
MONDAY EVENING...WITH SIMILAR TOTALS OVER THE HIGHER MTNS RIDGES
AND PASSES. THIS SYSTEM DOES NOT LOOK LIKE A BIG PRECIP PRODUCER
FOR US..BUT WE/LL TAKE WHAT WE CAN GET.
ON TUESDAY...MODELS SLOW TO MOVE OUT THIS TROUGH. SOME ACTUALLY
SHOW THIS SYSTEM WOBBLING BACK OVER EASTERN COLORADO DURING THE
DAY WHICH WOULD KEEP THE AREA UNDER CLOUDS AND COOL TEMPS AND
POSSIBLY KEEP A FEW SHOWERS AROUND. BY WEDNESDAY AND BEYOND
HIGH PRESSURE MOVES IN FROM THE WEST RESULTING IN A QUICK WARMUP
AND A RETURN TO DRY CONDITIONS AND PLENTY OF SUNSHINE AREAWIDE.
AVIATION...WINDS WILL REMAIN SOUTHERLY THROUGH TODAY AND TONIGHT.
MAY SEE SOME GUSTS TO 20 KNOTS THIS AFTERNOON AS STRONGER WINDS
ALOFT MIX DOWN. WILL SEE PERIODS OF HIGH CLOUDS THROUGH THE 24
HOURS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....BAKER
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
247 PM CDT SAT MAR 31 2012
.DISCUSSION...
941 AM CDT
SOME CHANGES MADE TO THE GOING CLOUD AND TEMPERATURE TRENDS TO
SLOW THE CLEARING IN A FEW AREAS AND ACCORDINGLY STIFLE THE
TEMPERATURE RISE.
A BLANKET OF CLOUDS REMAIN OVER THE REGION THIS MORNING WITHIN
LOW-LEVEL RIDGING. RAOBS AND AMDAR MEASUREMENTS...AND SATELLITE
ESTIMATES...INDICATE THE CLOUD DEPTH BETWEEN 700 AND 1000 FT
THICK...WHICH IS CERTAINLY SHALLOW ENOUGH FOR THE FINAL DAY OF
MARCH THAT ONE WOULD THINK HOLES WILL BEGIN TO DEVELOP AND SPREAD
QUICKLY. EVEN SOME FURTHER SUBSIDENCE IS PREDICTED THE NEXT FEW
HOURS ABOVE THE CLOUD LAYER TO AID THAT. THE LATEST HRRR AND 31.12
NAM INDICATE SOME SCATTERING OVER LAKE MI INTO FAR NORTHEAST IL
AND NORTHWEST IN THROUGH THE NEXT FEW HOURS....WHICH MAKES DECENT
SENSE WITH DECREASING DEW POINTS WORKING IN FROM THAT DIRECTION.
ALSO A BREAK DOWN IN CLOUDS IS FAVORED IN RELATIVE HUMIDITY FIELDS
ACROSS THE SOUTH AND THE WEST.
THE ONE AREA THAT IS SHOWING SOMEWHAT OF A CONSISTENT SIGNAL TO BE
CLOUDED IN POTENTIALLY THROUGH MID TO LATE AFTERNOON IS THE
WINNEBAGO...BOONE... MCHENRY...DEKALB...AND KANE COUNTY AREAS.
OBVIOUSLY THAT IS A SPECIFIC AREA...BUT THE IDEA THAT TOWARD THE
WISCONSIN STATE LINE AWAY FROM THE DRY ADVECTION FROM THE EAST
WILL BE ONE OF THE FINAL AREAS TO CLEAR SEEMS REASONABLE. WITH
ONLY 2 TO 4 DEGREES OR SO MORE OF WARMING THROUGH NOON UNDER
OVERCAST SKY...WENT AHEAD AND CUT THEIR HIGH TEMPERATURE BY
SEVERAL DEGREES...AND TOOK 1 TO 2 DEGREES OFF ELSEWHERE. WITH THE
EASTERLY FLOW OFF THE LAKE...BORDERING LAKE COUNTIES OF NORTHEAST
IL ALSO SHOULD NOT CLIMB TOO RAPIDLY THIS AFTERNOON...WITH HIGHS
AT OR JUST A TAD ABOVE NORMAL. STILL LOWER TO MID 60S EXPECTED
ACROSS THE FAR SOUTH AND WEST.
MTF
//PREV DISCUSSION...
257 AM CDT
TODAY AND TONIGHT...RIDGE AXIS IN PLACE WITH EXPANSIVE AREA OF
STRATUS TRAPPED UNDER STRONG INVERSION EARLY THIS MORNING. EXPECT
CLOUD COVER TO ERODE BY LATE MORNING OR EARLY AFTERNOON UNDER
ANTICYCLONIC FLOW AND SUBSIDENCE. TEMPERATURES WILL THEN WARM INTO
THE LOW TO MID 60S AWAY FROM THE LAKE FRONT. NORTHEASTERLY FLOW OFF
THE LAKE WILL KEEP TEMPERATURES IN THE LOW TO MID 50S CLOSER TO THE
LAKEFRONT TODAY. THIS AFTERNOON...MOISTURE POOLING IS EXPECTED
ACROSS MISSOURI INTO CENTRAL IOWA WHERE DEW POINTS ARE EXPECTED TO
RISE INTO THE LOW 60S AS WARM FRONT LIFTS BACK NORTH. BY
TONIGHT...ISENTROPIC ASCENT WILL INCREASE WITH SHOWERS AND
THUNDERSTORMS DEVELOPING ALONG THE MOISTURE AXIS OVER PORTIONS OF
IOWA AND PUSHING EAST ON THE NOSE OF 40KT LOW LEVEL JET INTO
NORTHERN ILLINOIS LATE TONIGHT. SURFACE WINDS WILL VEER TO THE
SOUTHEAST WITH WARM ADVECTION OVERNIGHT HELPING TO PROP UP
TEMPERATURES...WHICH ARE EXPECTED TO FALL INTO THE UPPER 40S TO LOW
50S BY LATE EVENING THE HOLD STEADY OR SLOWLY RISE OVERNIGHT.
SUNDAY...WARM FRONT DOES NOT ADVANCE MUCH DURING THE DAY SUNDAY WITH
A NORTHERN STREAM SYSTEM DROPPING SOUTHEAST ACROSS QUEBEC AND
TURNING FLOW BACK TO THE NORTHEAST FOR AT LEAST NORTHERN PORTIONS OF
THE FORECAST AREA. APPEARS THAT WITH THE FRONTAL BOUNDARY LINGERING
THROUGH THE DAY SUNDAY THAT WE WILL SET UP A STRONG TEMP GRADIENT
ACROSS THE CWA. ECMWF HAS COME MORE IN LINE WITH THIS SOLUTION WHICH
GFS HAS BEEN ADVERTISING THE PAST COUPLE DAYS. DROPPED TEMPERATURES
SEVERAL DEGREES ALONG THE LAKE SHORE AND WENT WITH NON-DIURNAL
TREND...SHOWING TEMPERATURES PEAKING EARLY IN THE DAY THEN DROPPING
AS LAKE AIR SPREADS INLAND WITH THE HELP OF SYNOPTICALLY NORTHEAST
FLOW. LINGERING SHOWERS AND CLOUD COVER IN THE MORNING ADD
ADDITIONAL UNCERTAINTY TO TEMPERATURE FORECAST...PARTICULARLY IN THE
WARMER AIR ACROSS EAST CENTRAL ILLINOIS.
MONDAY...GUIDANCE STILL A BIT MIXED ON HOW FAR NORTH THE WARM FRONT
WILL LIFT WITH GFS A SLOW/SOUTHERN OUTLIER AND PLACING PRECIP ALONG
THE WARM FRONT ACROSS NORTHERN ILLINOIS. OPTED TO KEEP FORECAST DRY
PER NAM/GEM/ECMWF SOLUTIONS WITH DRY AIR IN PLACE...DEEP MIXING
LAYERS AND VERY WARM TEMPERATURES. BUMPED UP TEMPS...ESPECIALLY
ACROSS THE SOUTH. BIAS CORRECTED NAM/ECMWF SHOW TEMPS SOARING INTO
THE 90S SOUTH OF THE I-80 CORRIDOR. SREF PLUMES SUPPORT MID 80S
ACROSS THE SOUTHERN PORTIONS OF THE CWA WITH STRONG CLUSTERING IN
THAT RANGE BUT A FEW SIGNIFICANT COLD OUTLIERS PULLING THE MEAN
INTO THE LOW 80S. MODEL CONSENSUS BLEND ALSO SUPPORTS MID 80S
ACROSS THE SOUTH. LAKE BREEZE IS POSSIBLE WITH MARGINAL WINDS
SPEEDS ALOFT SO MAY SEE TEMPERATURES COOL ALONG THE LAKE FRONT
THAT AFTERNOON.
TUESDAY THROUGH FRIDAY...A COLD FRONT WILL SWEEP ACROSS THE REGION
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS
WHILE USHERING IN MORE SEASONABLE TEMPERATURES FOR THE REMAINDER OF
THE WEEK. HIGH PRESSURE BUILDS ACROSS THE GREAT LAKES REGION
WEDNESDAY AND LINGERS THROUGH THE END OF THE WEEK. DRY CONDITIONS
SHOULD PERSIST WITH PLENTY OF SUNSHINE. BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LIGHT EAST TO SOUTHEAST WINDS.
* CEILING AT MDW SCATTERING OUT BY LATE AFTERNOON.
* CHANCE FOR SHRA/TSRA TO MOVE ACROSS LATE TONIGHT/EARLY SUNDAY
MORNING.
PAW
//DISCUSSION...UPDATED 18Z...
SATELLITE SHOWS CEILINGS BREAKING UP TO THE SOUTHWEST OF THE
TERMINALS AND SOME THIN SPOTS DEVELOPING OVER NORTHEAST
ILLINOIS. THE TIMING OF CEILINGS SCATTERING OUT EARLY TO MID
AFTERNOON IS LOOKING GOOD.
THE NEXT SYSTEM WILL MOVE ACROSS NORTHERN ILLINOIS AND NORTHWEST
INDIANA SUNDAY MORNING. THERE IS POTENTIAL FOR A BAND OF SHRA/TSRA
TO MOVE ACROSS THE TERMINALS IN ADVANCE OF THE SYSTEM. HAVE NOT
CHANGED THE LATE TONIGHT/EARLY SUNDAY MORNING TIME FRAME AS BEING
THE MOST FAVORABLE FOR SHRA/TSRA...BUT MAY NEED TO ADJUST AS IT GETS
CLOSER.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN WIND.
* MEDIUM CONFIDENCE IN CIG TREND AT MDW.
* MEDIUM CONFIDENCE IN SHRA/TSRA OCCURRING LATE TONIGHT/SUNDAY
MORNING. LOW CONFIDENCE IN TIMING.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...VFR WITH CHANCE TSRA MONDAY NIGHT.
TUESDAY...VFR WITH CHANCE SHRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
MDB
&&
.MARINE...
115 PM CDT
WINDS WILL TURN SOUTHERLY AND GRADUALLY INCREASE ACROSS LAKE MI
TONIGHT AS HIGH PRESSURE MOVES EAST FROM THE CENTRAL GREAT LAKES.
LOW PRESSURE WILL EVOLVE EASTWARD ACROSS THE LAKE ON SUNDAY MORNING.
AN ASSOCIATED COLD FRONT WILL SLIP SOUTH AS THIS OCCURS...TURNING
WINDS NORTHERLY ACROSS THE LAKE. THIS FRONT WILL LIKELY MOVE ACROSS
THE NEARSHORE AREAS OF IL AND IN DURING THE EARLY TO MID AFTERNOON
ON SUNDAY. HIGH PRESSURE WILL BRIEFLY PREVAIL ON SUNDAY NIGHT BEFORE
ANOTHER LOW MOVES EAST ACROSS IOWA INTO NORTHERN ILLINOIS. WINDS ARE
EXPECTED TO TURN BACK SOUTHEAST AHEAD OF THIS FEATURE ON MONDAY
AFTERNOON...WITH SOME GUSTS UP TO 25 KT...INCLUDING POSSIBLY IN THE
ILLINOIS NEAR SHORE AREAS. BEHIND THE LOW PASSAGE LATE MONDAY NIGHT
INTO EARLY TUESDAY...THE WINDS WILL ONCE AGAIN SWING BACK NORTHERLY.
HIGH PRESSURE IS THEN FORECAST TO ENCOMPASS MUCH OF THE LAKE
WEDNESDAY THROUGH FRIDAY...THOUGH CONFIDENCE IN THIS IS FAIRLY LOW
DUE TO A CLOSED UPPER LOW IN THE CENTRAL PLAINS WHICH COULD MEANDER
CLOSE ENOUGH TO CAUSE SLIGHTLY STRONGER WINDS. OVERALL AT THIS
TIME...NO LONG-LIVED GUSTY OR HIGH WAVE PERIODS ARE EXPECTED IN
THE NEXT WEEK.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
115 PM CDT SAT MAR 31 2012
.DISCUSSION...
941 AM CDT
SOME CHANGES MADE TO THE GOING CLOUD AND TEMPERATURE TRENDS TO
SLOW THE CLEARING IN A FEW AREAS AND ACCORDINGLY STIFLE THE
TEMPERATURE RISE.
A BLANKET OF CLOUDS REMAIN OVER THE REGION THIS MORNING WITHIN
LOW-LEVEL RIDGING. RAOBS AND AMDAR MEASUREMENTS...AND SATELLITE
ESTIMATES...INDICATE THE CLOUD DEPTH BETWEEN 700 AND 1000 FT
THICK...WHICH IS CERTAINLY SHALLOW ENOUGH FOR THE FINAL DAY OF
MARCH THAT ONE WOULD THINK HOLES WILL BEGIN TO DEVELOP AND SPREAD
QUICKLY. EVEN SOME FURTHER SUBSIDENCE IS PREDICTED THE NEXT FEW
HOURS ABOVE THE CLOUD LAYER TO AID THAT. THE LATEST HRRR AND 31.12
NAM INDICATE SOME SCATTERING OVER LAKE MI INTO FAR NORTHEAST IL
AND NORTHWEST IN THROUGH THE NEXT FEW HOURS....WHICH MAKES DECENT
SENSE WITH DECREASING DEW POINTS WORKING IN FROM THAT DIRECTION.
ALSO A BREAK DOWN IN CLOUDS IS FAVORED IN RELATIVE HUMIDITY FIELDS
ACROSS THE SOUTH AND THE WEST.
THE ONE AREA THAT IS SHOWING SOMEWHAT OF A CONSISTENT SIGNAL TO BE
CLOUDED IN POTENTIALLY THROUGH MID TO LATE AFTERNOON IS THE
WINNEBAGO...BOONE... MCHENRY...DEKALB...AND KANE COUNTY AREAS.
OBVIOUSLY THAT IS A SPECIFIC AREA...BUT THE IDEA THAT TOWARD THE
WISCONSIN STATE LINE AWAY FROM THE DRY ADVECTION FROM THE EAST
WILL BE ONE OF THE FINAL AREAS TO CLEAR SEEMS REASONABLE. WITH
ONLY 2 TO 4 DEGREES OR SO MORE OF WARMING THROUGH NOON UNDER
OVERCAST SKY...WENT AHEAD AND CUT THEIR HIGH TEMPERATURE BY
SEVERAL DEGREES...AND TOOK 1 TO 2 DEGREES OFF ELSEWHERE. WITH THE
EASTERLY FLOW OFF THE LAKE...BORDERING LAKE COUNTIES OF NORTHEAST
IL ALSO SHOULD NOT CLIMB TOO RAPIDLY THIS AFTERNOON...WITH HIGHS
AT OR JUST A TAD ABOVE NORMAL. STILL LOWER TO MID 60S EXPECTED
ACROSS THE FAR SOUTH AND WEST.
MTF
//PREV DISCUSSION...
257 AM CDT
TODAY AND TONIGHT...RIDGE AXIS IN PLACE WITH EXPANSIVE AREA OF
STRATUS TRAPPED UNDER STRONG INVERSION EARLY THIS MORNING. EXPECT
CLOUD COVER TO ERODE BY LATE MORNING OR EARLY AFTERNOON UNDER
ANTICYCLONIC FLOW AND SUBSIDENCE. TEMPERATURES WILL THEN WARM INTO
THE LOW TO MID 60S AWAY FROM THE LAKE FRONT. NORTHEASTERLY FLOW OFF
THE LAKE WILL KEEP TEMPERATURES IN THE LOW TO MID 50S CLOSER TO THE
LAKEFRONT TODAY. THIS AFTERNOON...MOISTURE POOLING IS EXPECTED
ACROSS MISSOURI INTO CENTRAL IOWA WHERE DEW POINTS ARE EXPECTED TO
RISE INTO THE LOW 60S AS WARM FRONT LIFTS BACK NORTH. BY
TONIGHT...ISENTROPIC ASCENT WILL INCREASE WITH SHOWERS AND
THUNDERSTORMS DEVELOPING ALONG THE MOISTURE AXIS OVER PORTIONS OF
IOWA AND PUSHING EAST ON THE NOSE OF 40KT LOW LEVEL JET INTO
NORTHERN ILLINOIS LATE TONIGHT. SURFACE WINDS WILL VEER TO THE
SOUTHEAST WITH WARM ADVECTION OVERNIGHT HELPING TO PROP UP
TEMPERATURES...WHICH ARE EXPECTED TO FALL INTO THE UPPER 40S TO LOW
50S BY LATE EVENING THE HOLD STEADY OR SLOWLY RISE OVERNIGHT.
SUNDAY...WARM FRONT DOES NOT ADVANCE MUCH DURING THE DAY SUNDAY WITH
A NORTHERN STREAM SYSTEM DROPPING SOUTHEAST ACROSS QUEBEC AND
TURNING FLOW BACK TO THE NORTHEAST FOR AT LEAST NORTHERN PORTIONS OF
THE FORECAST AREA. APPEARS THAT WITH THE FRONTAL BOUNDARY LINGERING
THROUGH THE DAY SUNDAY THAT WE WILL SET UP A STRONG TEMP GRADIENT
ACROSS THE CWA. ECMWF HAS COME MORE IN LINE WITH THIS SOLUTION WHICH
GFS HAS BEEN ADVERTISING THE PAST COUPLE DAYS. DROPPED TEMPERATURES
SEVERAL DEGREES ALONG THE LAKE SHORE AND WENT WITH NON-DIURNAL
TREND...SHOWING TEMPERATURES PEAKING EARLY IN THE DAY THEN DROPPING
AS LAKE AIR SPREADS INLAND WITH THE HELP OF SYNOPTICALLY NORTHEAST
FLOW. LINGERING SHOWERS AND CLOUD COVER IN THE MORNING ADD
ADDITIONAL UNCERTAINTY TO TEMPERATURE FORECAST...PARTICULARLY IN THE
WARMER AIR ACROSS EAST CENTRAL ILLINOIS.
MONDAY...GUIDANCE STILL A BIT MIXED ON HOW FAR NORTH THE WARM FRONT
WILL LIFT WITH GFS A SLOW/SOUTHERN OUTLIER AND PLACING PRECIP ALONG
THE WARM FRONT ACROSS NORTHERN ILLINOIS. OPTED TO KEEP FORECAST DRY
PER NAM/GEM/ECMWF SOLUTIONS WITH DRY AIR IN PLACE...DEEP MIXING
LAYERS AND VERY WARM TEMPERATURES. BUMPED UP TEMPS...ESPECIALLY
ACROSS THE SOUTH. BIAS CORRECTED NAM/ECMWF SHOW TEMPS SOARING INTO
THE 90S SOUTH OF THE I-80 CORRIDOR. SREF PLUMES SUPPORT MID 80S
ACROSS THE SOUTHERN PORTIONS OF THE CWA WITH STRONG CLUSTERING IN
THAT RANGE BUT A FEW SIGNIFICANT COLD OUTLIERS PULLING THE MEAN
INTO THE LOW 80S. MODEL CONSENSUS BLEND ALSO SUPPORTS MID 80S
ACROSS THE SOUTH. LAKE BREEZE IS POSSIBLE WITH MARGINAL WINDS
SPEEDS ALOFT SO MAY SEE TEMPERATURES COOL ALONG THE LAKE FRONT
THAT AFTERNOON.
TUESDAY THROUGH FRIDAY...A COLD FRONT WILL SWEEP ACROSS THE REGION
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS
WHILE USHERING IN MORE SEASONABLE TEMPERATURES FOR THE REMAINDER OF
THE WEEK. HIGH PRESSURE BUILDS ACROSS THE GREAT LAKES REGION
WEDNESDAY AND LINGERS THROUGH THE END OF THE WEEK. DRY CONDITIONS
SHOULD PERSIST WITH PLENTY OF SUNSHINE. BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* CIGS SCATTERING OUT THIS AFTERNOON.
* LIGHT WINDS GRADUALLY SHIFTING TO MORE OF AN EAST-SOUTHEAST
DIRECTION THROUGH THE AFTERNOON.
* CHANCE FOR SHRA/TSRA TO MOVE ACROSS LATE TONIGHT/EARLY SUNDAY
MORNING.
PAW
//DISCUSSION...UPDATED 18Z...
SATELLITE SHOWS CEILINGS BREAKING UP TO THE SOUTHWEST OF THE
TERMINALS AND SOME THIN SPOTS DEVELOPING OVER NORTHEAST
ILLINOIS. THE TIMING OF CEILINGS SCATTERING OUT EARLY TO MID
AFTERNOON IS LOOKING GOOD.
THE NEXT SYSTEM WILL MOVE ACROSS NORTHERN ILLINOIS AND NORTHWEST
INDIANA SUNDAY MORNING. THERE IS POTENTIAL FOR A BAND OF SHRA/TSRA
TO MOVE ACROSS THE TERMINALS IN ADVANCE OF THE SYSTEM. HAVE NOT
CHANGED THE LATE TONIGHT/EARLY SUNDAY MORNING TIME FRAME AS BEING
THE MOST FAVORABLE FOR SHRA/TSRA...BUT MAY NEED TO ADJUST AS IT GETS
CLOSER.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN CEILING TREND AND TIMING.
* HIGH CONFIDENCE IN WIND TREND.
* MEDIUM CONFIDENCE IN SHRA/TSRA OCCURRING LATE TONIGHT/SUNDAY
MORNING. LOW CONFIDENCE IN TIMING.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...VFR WITH CHANCE TSRA MONDAY NIGHT.
TUESDAY...VFR WITH CHANCE SHRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
MDB
&&
.MARINE...
115 PM CDT
WINDS WILL TURN SOUTHERLY AND GRADUALLY INCREASE ACROSS LAKE MI
TONIGHT AS HIGH PRESSURE MOVES EAST FROM THE CENTRAL GREAT LAKES.
LOW PRESSURE WILL EVOLVE EASTWARD ACROSS THE LAKE ON SUNDAY MORNING.
AN ASSOCIATED COLD FRONT WILL SLIP SOUTH AS THIS OCCURS...TURNING
WINDS NORTHERLY ACROSS THE LAKE. THIS FRONT WILL LIKELY MOVE ACROSS
THE NEARSHORE AREAS OF IL AND IN DURING THE EARLY TO MID AFTERNOON
ON SUNDAY. HIGH PRESSURE WILL BRIEFLY PREVAIL ON SUNDAY NIGHT BEFORE
ANOTHER LOW MOVES EAST ACROSS IOWA INTO NORTHERN ILLINOIS. WINDS ARE
EXPECTED TO TURN BACK SOUTHEAST AHEAD OF THIS FEATURE ON MONDAY
AFTERNOON...WITH SOME GUSTS UP TO 25 KT...INCLUDING POSSIBLY IN THE
ILLINOIS NEAR SHORE AREAS. BEHIND THE LOW PASSAGE LATE MONDAY NIGHT
INTO EARLY TUESDAY...THE WINDS WILL ONCE AGAIN SWING BACK NORTHERLY.
HIGH PRESSURE IS THEN FORECAST TO ENCOMPASS MUCH OF THE LAKE
WEDNESDAY THROUGH FRIDAY...THOUGH CONFIDENCE IN THIS IS FAIRLY LOW
DUE TO A CLOSED UPPER LOW IN THE CENTRAL PLAINS WHICH COULD MEANDER
CLOSE ENOUGH TO CAUSE SLIGHTLY STRONGER WINDS. OVERALL AT THIS
TIME...NO LONG-LIVED GUSTY OR HIGH WAVE PERIODS ARE EXPECTED IN
THE NEXT WEEK.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1255 PM CDT SAT MAR 31 2012
.DISCUSSION...
ISSUED 1040 AM CDT SAT MAR 31 2012
LOW STRATUS DECK COVERED MUCH OF CENTRAL AND SOUTHEAST THIS
MORNING. THIS MOISTURE WAS TRAPPED BENEATH A PRETTY STOUT
SUBSIDENCE INVERSION PER 12Z KILX/KDVN SOUNDINGS. THE INVERSION IS
STRONGER THAN FORECAST BY THE MODELS...AND HAS RESULTED IN A
SLOWER CLEARING TRENDS THAN PREVIOUSLY ANTICIPATED. HOWEVER...
RECENT VISIBLE SATELLITE LOOPS SHOW THE STRATUS STARTING TO ERODE
FROM THE SOUTHWEST. THIS CLEARING TREND IS EXPECTED TO CONTINUE AS
DIURNAL HEATING INCREASES...AND THE CLEARING TREND WILL ALSO BE
AIDED BY SURFACE WINDS TRENDING TO THE SOUTHEAST IN THE WAKE OF
THE SURFACE RIDGE AXIS CURRENTLY OVER THE AREA.
HAVE UPDATED GRIDS FOR SLOWER CLEARING TRENDS...AS WELL AS A
RELATED SLOWER TEMPERATURE WARM UP. ALSO KNOCKED A DEGREE OR TWO
OFF MAX TEMPERATURES ALONG/NORTH OF THE I-74 CORRIDOR WHERE SKIES
WILL CLEAR THE LATEST AND PRESENT TEMPS ARE 20 DEGREES BELOW
FORECAST HIGHS.
BAK
&&
.AVIATION...
ISSUED 1255 PM CDT SAT MAR 31 2012
LOW CLOUDS HAVE FINALLY ERODED ACROSS THE CENTRAL ILLINOIS
TERMINALS...LEAVING MAINLY SCATTERED MID/HIGH CLOUDS IN THEIR
WAKE. VFR CONDITIONS SHOULD PREVAIL FOR THE MAJORITY OF THE 18Z TAF
VALID TIME. THE MAIN FLY IN THE OINTMENT IS THE EXPECTED MCS
DEVELOPMENT UPSTREAM ACROSS IOWA TONIGHT. THE MAJORITY OF THE
FORECAST MODELS HAVE THIS STORM COMPLEX IMPACTING AT LEAST SOME OF
THE TERMINALS OVERNIGHT/EARLY SUNDAY. STILL A FAIR AMOUNT OF
UNCERTAINTY WITH RESPECT TO TIMING AND AREAL COVERAGE...SO HAVE
ONLY CARRIED A VCTS MENTION IN THE TERMINALS AND LEFT CIGS/VSBYS
VFR. THIS COULD REQUIRE SIGNIFICANT CHANGES ONCE THE STORMS
INITIATE AND WE HAVE A BETTER IDEA OF WHERE/WHEN THEY WILL IMPACT
CENTRAL ILLINOIS.
WINDS...GENERALLY AOB 10 KTS...WILL CONTINUE TO TREND MORE
SOUTHERLY WITH TIME THIS AFTERNOON/TONIGHT AS A SURFACE RIDGE AXIS
CLEARS THE AREA. THEY SHOULD TREND MORE SOUTHWESTERLY AFTER
DAYBREAK SUNDAY IN THE WAKE OF THE MCS. CONSIDERABLE LOCAL
VARIABILITY IS POSSIBLE IF STORMS IMPACT A TERMINAL LATER TONIGHT.
BAK
&&
.PREV DISCUSSION...
ISSUED 255 AM CDT SAT MAR 31 2012
THE COLD FRONT THAT PASSED THROUGH LAST EVENING WAS NEAR THE OHIO
RIVER EARLY THIS MORNING. NORTHEAST WINDS ARE BRINGING A STRATUS
DECK SOUTHEASTWARD...REACHING TAYLORVILLE AND MATTOON AT 3 AM.
SIGNIFICANT PUSH OF COOLER AIR HAS DROPPED TEMPERATURES INTO THE
40S UNDERNEATH THE CLOUDS.
INITIAL FORECAST CONCERNS INVOLVE TEMPERATURES TODAY WITH THE
EFFECTS OF ANY LINGERING CLOUD COVER...AS WELL AS MUCH WARMER
CONDITIONS FOR SUNDAY AND MONDAY. TIMING AND COVERAGE OF MIDWEEK
SHOWERS ARE ALSO AN ISSUE.
SHORT TERM...TODAY THROUGH MONDAY...
LATEST RUC AND HRRR MODELS SUGGESTING THAT THE CLOUD DECK SHOULD
TRACK A LITTLE FURTHER SOUTH IN THE NEXT FEW HOURS...BEFORE
BEGINNING TO ERODE. WITH THIS THINKING...HAVE TRENDED THE SKY
GRIDS TO BE MOSTLY SUNNY BY MIDDAY...EXCEPT PERHAPS OVER THE FAR
NORTH. SHOULD GET TEMPERATURES INTO THE 70S ACROSS THE
SOUTHWEST...WITH COOLER 60S NORTHEAST. A SLOWER THAN EXPECTED
CLOUD BREAKUP WOULD RESULT IN TEMPERATURES IN THAT AREA CLOSER TO
THE COOLER MET GUIDANCE...BUT HAVE GONE CLOSER TO THE WARMER MAV
MOS AT THE MOMENT.
LATEST MODEL SUITE SHOWING MCS DEVELOPMENT ACROSS EASTERN IOWA
OVERNIGHT...AS A FRONTAL BOUNDARY ESTABLISHES ITSELF FROM NORTHERN
IOWA TO LOWER MICHIGAN. LATEST ECMWF MODEL IS THE FURTHEST SOUTH
WITH THE TRACK...REACHING POTENTIALLY AS FAR SOUTH AS SPRINGFIELD
AND DECATUR BY SUNRISE. THE REMAINING MODELS HAVE THE MCS SKIMMING
THE NORTH/NORTHEAST BORDER. HAVE MAINTAINED THE RAIN CHANCES OVER
THE NORTHERN HALF OF THE CWA...PRIMARILY BETWEEN MIDNIGHT AND
SUNRISE...AND SCALED THEM BACK ACROSS THE SOUTH.
UPPER RIDGE PROGGED BY THE MODELS TO AMPLIFY OVER THE CENTRAL
UNITED STATES THIS WEEKEND...SHIFTING TO THE MISSISSIPPI VALLEY BY
EARLY MONDAY MORNING. PRETTY GOOD SLUG OF WARM AIR WILL SPREAD
OVER THE STATE...WITH 850 MB TEMPERATURES RISING TO NEAR 20C ON
MONDAY. HAVE CONTINUED WITH THE 80S FOR HIGHS FOR SUNDAY...BUT
WILL NEED TO MONITOR THE CIRRUS BLOWOFF FROM THE MCS WHICH MAY
HELP KEEP TEMPS FROM RISING QUITE AS MUCH. HOWEVER...HAVE BOOSTED
HIGHS ON MONDAY BY A FEW DEGREES FROM EARLIER FORECASTS...AS THAT
WARMER AIR AT 850 MB MIXES TOWARD THE SURFACE. MAY SEE SOME RECORD
HIGHS AGAIN...AS CURRENT VALUES ARE IN THE MID TO UPPER 80S.
MAV/MEX MOS GUIDANCE SUGGESTING SOME 90 DEGREE READINGS ARE
POSSIBLE ACROSS THE SOUTHWEST CWA.
LONG TERM...TUESDAY THROUGH FRIDAY...
UPPER LEVEL TROUGHING ACROSS THE DESERT SOUTHWEST LATE THIS
WEEKEND WILL CUT OFF INTO A CLOSED LOW...WHICH IS PROGGED TO DRIFT
INTO THE CENTRAL PLAINS BY MIDWEEK. EXTENDED RANGE MODELS STARTING
TO TREND NORTHWARD WITH THIS TRACK...WITH THE GFS THE FARTHEST
NORTH INTO SOUTHERN IOWA. CURRENTLY PREFER THE MORE SOUTHERN
SOLUTION SOUTH OF THE OHIO VALLEY. AN EXTENDED PERIOD OF RAIN IS
LIKELY OVER PORTIONS OF THE MID-MISSISSIPPI VALLEY...BUT DRY
EASTERLY WINDS ASSOCIATED WITH A HIGH OVER THE GREAT LAKES WILL
CAUSE SOME EROSION OF THE PRECIP ON THE NORTHEAST FLANK. THE
LATEST ECMWF SURGES THE PRECIPITATION MUCH FURTHER NORTH THAN ITS
EARLIER RUN AND COVERS MOST OF THE CWA...WHILE THE CANADIAN MODEL
IS MORE LIMITED TO THE SOUTHEAST. HAVE INTRODUCED SLIGHT CHANCE
POPS FOR NOW ACROSS THE SOUTHEAST CWA WEDNESDAY NIGHT AND
THURSDAY...AND THESE MAY NEED TO BE BOOSTED IN FUTURE PACKAGES AS
MODEL AGREEMENT BECOMES TIGHTER.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1240 PM CDT SAT MAR 31 2012
.DISCUSSION...
941 AM CDT
SOME CHANGES MADE TO THE GOING CLOUD AND TEMPERATURE TRENDS TO
SLOW THE CLEARING IN A FEW AREAS AND ACCORDINGLY STIFLE THE
TEMPERATURE RISE.
A BLANKET OF CLOUDS REMAIN OVER THE REGION THIS MORNING WITHIN
LOW-LEVEL RIDGING. RAOBS AND AMDAR MEASUREMENTS...AND SATELLITE
ESTIMATES...INDICATE THE CLOUD DEPTH BETWEEN 700 AND 1000 FT
THICK...WHICH IS CERTAINLY SHALLOW ENOUGH FOR THE FINAL DAY OF
MARCH THAT ONE WOULD THINK HOLES WILL BEGIN TO DEVELOP AND SPREAD
QUICKLY. EVEN SOME FURTHER SUBSIDENCE IS PREDICTED THE NEXT FEW
HOURS ABOVE THE CLOUD LAYER TO AID THAT. THE LATEST HRRR AND 31.12
NAM INDICATE SOME SCATTERING OVER LAKE MI INTO FAR NORTHEAST IL
AND NORTHWEST IN THROUGH THE NEXT FEW HOURS....WHICH MAKES DECENT
SENSE WITH DECREASING DEW POINTS WORKING IN FROM THAT DIRECTION.
ALSO A BREAK DOWN IN CLOUDS IS FAVORED IN RELATIVE HUMIDITY FIELDS
ACROSS THE SOUTH AND THE WEST.
THE ONE AREA THAT IS SHOWING SOMEWHAT OF A CONSISTENT SIGNAL TO BE
CLOUDED IN POTENTIALLY THROUGH MID TO LATE AFTERNOON IS THE
WINNEBAGO...BOONE... MCHENRY...DEKALB...AND KANE COUNTY AREAS.
OBVIOUSLY THAT IS A SPECIFIC AREA...BUT THE IDEA THAT TOWARD THE
WISCONSIN STATE LINE AWAY FROM THE DRY ADVECTION FROM THE EAST
WILL BE ONE OF THE FINAL AREAS TO CLEAR SEEMS REASONABLE. WITH
ONLY 2 TO 4 DEGREES OR SO MORE OF WARMING THROUGH NOON UNDER
OVERCAST SKY...WENT AHEAD AND CUT THEIR HIGH TEMPERATURE BY
SEVERAL DEGREES...AND TOOK 1 TO 2 DEGREES OFF ELSEWHERE. WITH THE
EASTERLY FLOW OFF THE LAKE...BORDERING LAKE COUNTIES OF NORTHEAST
IL ALSO SHOULD NOT CLIMB TOO RAPIDLY THIS AFTERNOON...WITH HIGHS
AT OR JUST A TAD ABOVE NORMAL. STILL LOWER TO MID 60S EXPECTED
ACROSS THE FAR SOUTH AND WEST.
MTF
//PREV DISCUSSION...
257 AM CDT
TODAY AND TONIGHT...RIDGE AXIS IN PLACE WITH EXPANSIVE AREA OF
STRATUS TRAPPED UNDER STRONG INVERSION EARLY THIS MORNING. EXPECT
CLOUD COVER TO ERODE BY LATE MORNING OR EARLY AFTERNOON UNDER
ANTICYCLONIC FLOW AND SUBSIDENCE. TEMPERATURES WILL THEN WARM INTO
THE LOW TO MID 60S AWAY FROM THE LAKE FRONT. NORTHEASTERLY FLOW OFF
THE LAKE WILL KEEP TEMPERATURES IN THE LOW TO MID 50S CLOSER TO THE
LAKEFRONT TODAY. THIS AFTERNOON...MOISTURE POOLING IS EXPECTED
ACROSS MISSOURI INTO CENTRAL IOWA WHERE DEW POINTS ARE EXPECTED TO
RISE INTO THE LOW 60S AS WARM FRONT LIFTS BACK NORTH. BY
TONIGHT...ISENTROPIC ASCENT WILL INCREASE WITH SHOWERS AND
THUNDERSTORMS DEVELOPING ALONG THE MOISTURE AXIS OVER PORTIONS OF
IOWA AND PUSHING EAST ON THE NOSE OF 40KT LOW LEVEL JET INTO
NORTHERN ILLINOIS LATE TONIGHT. SURFACE WINDS WILL VEER TO THE
SOUTHEAST WITH WARM ADVECTION OVERNIGHT HELPING TO PROP UP
TEMPERATURES...WHICH ARE EXPECTED TO FALL INTO THE UPPER 40S TO LOW
50S BY LATE EVENING THE HOLD STEADY OR SLOWLY RISE OVERNIGHT.
SUNDAY...WARM FRONT DOES NOT ADVANCE MUCH DURING THE DAY SUNDAY WITH
A NORTHERN STREAM SYSTEM DROPPING SOUTHEAST ACROSS QUEBEC AND
TURNING FLOW BACK TO THE NORTHEAST FOR AT LEAST NORTHERN PORTIONS OF
THE FORECAST AREA. APPEARS THAT WITH THE FRONTAL BOUNDARY LINGERING
THROUGH THE DAY SUNDAY THAT WE WILL SET UP A STRONG TEMP GRADIENT
ACROSS THE CWA. ECMWF HAS COME MORE IN LINE WITH THIS SOLUTION WHICH
GFS HAS BEEN ADVERTISING THE PAST COUPLE DAYS. DROPPED TEMPERATURES
SEVERAL DEGREES ALONG THE LAKE SHORE AND WENT WITH NON-DIURNAL
TREND...SHOWING TEMPERATURES PEAKING EARLY IN THE DAY THEN DROPPING
AS LAKE AIR SPREADS INLAND WITH THE HELP OF SYNOPTICALLY NORTHEAST
FLOW. LINGERING SHOWERS AND CLOUD COVER IN THE MORNING ADD
ADDITIONAL UNCERTAINTY TO TEMPERATURE FORECAST...PARTICULARLY IN THE
WARMER AIR ACROSS EAST CENTRAL ILLINOIS.
MONDAY...GUIDANCE STILL A BIT MIXED ON HOW FAR NORTH THE WARM FRONT
WILL LIFT WITH GFS A SLOW/SOUTHERN OUTLIER AND PLACING PRECIP ALONG
THE WARM FRONT ACROSS NORTHERN ILLINOIS. OPTED TO KEEP FORECAST DRY
PER NAM/GEM/ECMWF SOLUTIONS WITH DRY AIR IN PLACE...DEEP MIXING
LAYERS AND VERY WARM TEMPERATURES. BUMPED UP TEMPS...ESPECIALLY
ACROSS THE SOUTH. BIAS CORRECTED NAM/ECMWF SHOW TEMPS SOARING INTO
THE 90S SOUTH OF THE I-80 CORRIDOR. SREF PLUMES SUPPORT MID 80S
ACROSS THE SOUTHERN PORTIONS OF THE CWA WITH STRONG CLUSTERING IN
THAT RANGE BUT A FEW SIGNIFICANT COLD OUTLIERS PULLING THE MEAN
INTO THE LOW 80S. MODEL CONSENSUS BLEND ALSO SUPPORTS MID 80S
ACROSS THE SOUTH. LAKE BREEZE IS POSSIBLE WITH MARGINAL WINDS
SPEEDS ALOFT SO MAY SEE TEMPERATURES COOL ALONG THE LAKE FRONT
THAT AFTERNOON.
TUESDAY THROUGH FRIDAY...A COLD FRONT WILL SWEEP ACROSS THE REGION
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS
WHILE USHERING IN MORE SEASONABLE TEMPERATURES FOR THE REMAINDER OF
THE WEEK. HIGH PRESSURE BUILDS ACROSS THE GREAT LAKES REGION
WEDNESDAY AND LINGERS THROUGH THE END OF THE WEEK. DRY CONDITIONS
SHOULD PERSIST WITH PLENTY OF SUNSHINE. BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* CIGS SCATTERING OUT THIS AFTERNOON.
* LIGHT WINDS GRADUALLY SHIFTING TO MORE OF AN EAST-SOUTHEAST
DIRECTION THROUGH THE AFTERNOON.
* CHANCE FOR SHRA/TSRA TO MOVE ACROSS LATE TONIGHT/EARLY SUNDAY
MORNING.
PAW
//DISCUSSION...UPDATED 18Z...
SATELLITE SHOWS CEILINGS BREAKING UP TO THE SOUTHWEST OF THE
TERMINALS AND SOME THIN SPOTS DEVELOPING OVER NORTHEAST
ILLINOIS. THE TIMING OF CEILINGS SCATTERING OUT EARLY TO MID
AFTERNOON IS LOOKING GOOD.
THE NEXT SYSTEM WILL MOVE ACROSS NORTHERN ILLINOIS AND NORTHWEST
INDIANA SUNDAY MORNING. THERE IS POTENTIAL FOR A BAND OF SHRA/TSRA
TO MOVE ACROSS THE TERMINALS IN ADVANCE OF THE SYSTEM. HAVE NOT
CHANGED THE LATE TONIGHT/EARLY SUNDAY MORNING TIME FRAME AS BEING
THE MOST FAVORABLE FOR SHRA/TSRA...BUT MAY NEED TO ADJUST AS IT GETS
CLOSER.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN CEILING TREND AND TIMING.
* HIGH CONFIDENCE IN WIND TREND.
* MEDIUM CONFIDENCE IN SHRA/TSRA OCCURRING LATE TONIGHT/SUNDAY
MORNING. LOW CONFIDENCE IN TIMING.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...VFR WITH CHANCE TSRA MONDAY NIGHT.
TUESDAY...VFR WITH CHANCE SHRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
MDB
&&
.MARINE...
257 AM CDT
HIGH PRESSURE SPREAD FROM HUDSON BAY SOUTH AND SOUTHWEST ACROSS LAKE
MICHIGAN CONTINUES TO PROVIDE NORTHEAST TO SOUTHEAST WINDS ACROSS
THE LAKE EARLY THIS MORNING. WINDS WILL TURN SOUTHERLY THIS
AFTERNOON AS THE RIDGE AXIS SHIFTS EASTWARD AND OUT OF THE AREA. LOW
PRESSURE ACROSS THE CANADIAN PRAIRIES WILL WEAKEN AS IT MOVES EAST
BUT THE PRESSURE GRADIENT BETWEEN THE RIDGE AND THE TROUGH WILL
BRING AN INCREASE IN SOUTHERLY WINDS TO NORTHERN SECTIONS OF THE
LAKE THIS EVENING. THE WEAKENED LOW WILL PASS TO THE NORTHEAST OF
LAKE MICHIGAN SUNDAY MORNING SHIFTING WINDS TO THE NORTHEAST ONCE
AGAIN DURING THE DAY SUNDAY. A RIDGE AXIS WILL THEN ARRIVE FROM THE
NORTH SUNDAY EVENING BRINGING WINDS MORE TO THE SOUTHEAST BUT
ANOTHER LOW WILL PASS TO THE SOUTH OF THE LAKE TUESDAY MORNING
BRINGING A RETURN OF NORTHERLY WINDS. HIGH PRESSURE IS EXPECTED TO
RETURN LATER TUESDAY AND REMAIN IN PLACE THROUGH THE END OF THE
WEEK.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1104 AM CDT SAT MAR 31 2012
.DISCUSSION...
941 AM CDT
SOME CHANGES MADE TO THE GOING CLOUD AND TEMPERATURE TRENDS TO
SLOW THE CLEARING IN A FEW AREAS AND ACCORDINGLY STIFLE THE
TEMPERATURE RISE.
A BLANKET OF CLOUDS REMAIN OVER THE REGION THIS MORNING WITHIN
LOW-LEVEL RIDGING. RAOBS AND AMDAR MEASUREMENTS...AND SATELLITE
ESTIMATES...INDICATE THE CLOUD DEPTH BETWEEN 700 AND 1000 FT
THICK...WHICH IS CERTAINLY SHALLOW ENOUGH FOR THE FINAL DAY OF
MARCH THAT ONE WOULD THINK HOLES WILL BEGIN TO DEVELOP AND SPREAD
QUICKLY. EVEN SOME FURTHER SUBSIDENCE IS PREDICTED THE NEXT FEW
HOURS ABOVE THE CLOUD LAYER TO AID THAT. THE LATEST HRRR AND 31.12
NAM INDICATE SOME SCATTERING OVER LAKE MI INTO FAR NORTHEAST IL
AND NORTHWEST IN THROUGH THE NEXT FEW HOURS....WHICH MAKES DECENT
SENSE WITH DECREASING DEW POINTS WORKING IN FROM THAT DIRECTION.
ALSO A BREAK DOWN IN CLOUDS IS FAVORED IN RELATIVE HUMIDITY FIELDS
ACROSS THE SOUTH AND THE WEST.
THE ONE AREA THAT IS SHOWING SOMEWHAT OF A CONSISTENT SIGNAL TO BE
CLOUDED IN POTENTIALLY THROUGH MID TO LATE AFTERNOON IS THE
WINNEBAGO...BOONE... MCHENRY...DEKALB...AND KANE COUNTY AREAS.
OBVIOUSLY THAT IS A SPECIFIC AREA...BUT THE IDEA THAT TOWARD THE
WISCONSIN STATE LINE AWAY FROM THE DRY ADVECTION FROM THE EAST
WILL BE ONE OF THE FINAL AREAS TO CLEAR SEEMS REASONABLE. WITH
ONLY 2 TO 4 DEGREES OR SO MORE OF WARMING THROUGH NOON UNDER
OVERCAST SKY...WENT AHEAD AND CUT THEIR HIGH TEMPERATURE BY
SEVERAL DEGREES...AND TOOK 1 TO 2 DEGREES OFF ELSEWHERE. WITH THE
EASTERLY FLOW OFF THE LAKE...BORDERING LAKE COUNTIES OF NORTHEAST
IL ALSO SHOULD NOT CLIMB TOO RAPIDLY THIS AFTERNOON...WITH HIGHS
AT OR JUST A TAD ABOVE NORMAL. STILL LOWER TO MID 60S EXPECTED
ACROSS THE FAR SOUTH AND WEST.
MTF
//PREV DISCUSSION...
257 AM CDT
TODAY AND TONIGHT...RIDGE AXIS IN PLACE WITH EXPANSIVE AREA OF
STRATUS TRAPPED UNDER STRONG INVERSION EARLY THIS MORNING. EXPECT
CLOUD COVER TO ERODE BY LATE MORNING OR EARLY AFTERNOON UNDER
ANTICYCLONIC FLOW AND SUBSIDENCE. TEMPERATURES WILL THEN WARM INTO
THE LOW TO MID 60S AWAY FROM THE LAKE FRONT. NORTHEASTERLY FLOW OFF
THE LAKE WILL KEEP TEMPERATURES IN THE LOW TO MID 50S CLOSER TO THE
LAKEFRONT TODAY. THIS AFTERNOON...MOISTURE POOLING IS EXPECTED
ACROSS MISSOURI INTO CENTRAL IOWA WHERE DEW POINTS ARE EXPECTED TO
RISE INTO THE LOW 60S AS WARM FRONT LIFTS BACK NORTH. BY
TONIGHT...ISENTROPIC ASCENT WILL INCREASE WITH SHOWERS AND
THUNDERSTORMS DEVELOPING ALONG THE MOISTURE AXIS OVER PORTIONS OF
IOWA AND PUSHING EAST ON THE NOSE OF 40KT LOW LEVEL JET INTO
NORTHERN ILLINOIS LATE TONIGHT. SURFACE WINDS WILL VEER TO THE
SOUTHEAST WITH WARM ADVECTION OVERNIGHT HELPING TO PROP UP
TEMPERATURES...WHICH ARE EXPECTED TO FALL INTO THE UPPER 40S TO LOW
50S BY LATE EVENING THE HOLD STEADY OR SLOWLY RISE OVERNIGHT.
SUNDAY...WARM FRONT DOES NOT ADVANCE MUCH DURING THE DAY SUNDAY WITH
A NORTHERN STREAM SYSTEM DROPPING SOUTHEAST ACROSS QUEBEC AND
TURNING FLOW BACK TO THE NORTHEAST FOR AT LEAST NORTHERN PORTIONS OF
THE FORECAST AREA. APPEARS THAT WITH THE FRONTAL BOUNDARY LINGERING
THROUGH THE DAY SUNDAY THAT WE WILL SET UP A STRONG TEMP GRADIENT
ACROSS THE CWA. ECMWF HAS COME MORE IN LINE WITH THIS SOLUTION WHICH
GFS HAS BEEN ADVERTISING THE PAST COUPLE DAYS. DROPPED TEMPERATURES
SEVERAL DEGREES ALONG THE LAKE SHORE AND WENT WITH NON-DIURNAL
TREND...SHOWING TEMPERATURES PEAKING EARLY IN THE DAY THEN DROPPING
AS LAKE AIR SPREADS INLAND WITH THE HELP OF SYNOPTICALLY NORTHEAST
FLOW. LINGERING SHOWERS AND CLOUD COVER IN THE MORNING ADD
ADDITIONAL UNCERTAINTY TO TEMPERATURE FORECAST...PARTICULARLY IN THE
WARMER AIR ACROSS EAST CENTRAL ILLINOIS.
MONDAY...GUIDANCE STILL A BIT MIXED ON HOW FAR NORTH THE WARM FRONT
WILL LIFT WITH GFS A SLOW/SOUTHERN OUTLIER AND PLACING PRECIP ALONG
THE WARM FRONT ACROSS NORTHERN ILLINOIS. OPTED TO KEEP FORECAST DRY
PER NAM/GEM/ECMWF SOLUTIONS WITH DRY AIR IN PLACE...DEEP MIXING
LAYERS AND VERY WARM TEMPERATURES. BUMPED UP TEMPS...ESPECIALLY
ACROSS THE SOUTH. BIAS CORRECTED NAM/ECMWF SHOW TEMPS SOARING INTO
THE 90S SOUTH OF THE I-80 CORRIDOR. SREF PLUMES SUPPORT MID 80S
ACROSS THE SOUTHERN PORTIONS OF THE CWA WITH STRONG CLUSTERING IN
THAT RANGE BUT A FEW SIGNIFICANT COLD OUTLIERS PULLING THE MEAN
INTO THE LOW 80S. MODEL CONSENSUS BLEND ALSO SUPPORTS MID 80S
ACROSS THE SOUTH. LAKE BREEZE IS POSSIBLE WITH MARGINAL WINDS
SPEEDS ALOFT SO MAY SEE TEMPERATURES COOL ALONG THE LAKE FRONT
THAT AFTERNOON.
TUESDAY THROUGH FRIDAY...A COLD FRONT WILL SWEEP ACROSS THE REGION
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS
WHILE USHERING IN MORE SEASONABLE TEMPERATURES FOR THE REMAINDER OF
THE WEEK. HIGH PRESSURE BUILDS ACROSS THE GREAT LAKES REGION
WEDNESDAY AND LINGERS THROUGH THE END OF THE WEEK. DRY CONDITIONS
SHOULD PERSIST WITH PLENTY OF SUNSHINE. BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CIGS SCATTERING OUT EARLY AFTERNOON.
* EAST TO NORTHEAST WIND DIRECTION WILL GRADUALLY SHIFT TO A MORE
EAST-SOUTHEAST DIRECTION THIS AFTERNOON.
* CHANCE FOR SHRA/TSRA TO MOVE ACROSS LATE TONIGHT/EARLY SUNDAY
MORNING.
PAW
//DISCUSSION...UPDATED 12Z...
STRATUS REMAINS THE MAIN CONCERN THIS MORNING. MIX OF IFR/LOW MVFR
CIGS ACROSS THE TERMINALS AT ISSUANCE TIME. MAY STILL SEE A
SLIGHT LOWERING OVER THE NEXT 1-2 HOURS BUT EXPECT A SLOW UPWARD
TREND FROM THAT POINT ONWARD THROUGH THE MORNING. SCATTERING IS
EXPECTED TO OCCUR BY AROUND MIDDAY OR EARLY AFTERNOON BUT THE
SPECIFIC TIMING DETAILS MAY NEED SOME TWEAKING BUT HAVE GOOD
CONFIDENCE IN THE TREND. ONCE CLOUDS DO SCATTER VFR IS EXPECTED TO
PREVAIL INTO THE OVERNIGHT. WINDS WILL GENERALLY BE EAST TO
NORTHEAST WITH A TENDENCY TOWARD EAST-SOUTHEAST THIS
AFTERNOON...THOUGH GYY MAY SEE A CONTINUED NORTHEAST DIRECTION
UNTIL EARLY EVENING BEING CLOSE TO LAKE MICHIGAN.
NEXT CONCERN IS POTENTIAL FOR A BAND OF SHRA/TSRA TO MOVE ACROSS
THE TERMINALS LATE TONIGHT/EARLY SUNDAY MORNING. HAVE INCLUDED A
PROB30 MENTION EARLY SUNDAY. AT THIS POINT...BASED ON ATMOSPHERIC
SET UP...IMPACT DURATION WOULD BE ON THE ORDER OF A FEW HOURS BUT
THE TIME OF OCCURRENCE MAY NEED ADJUSTMENT.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM CONFIDENCE IN CIG TREND.
* HIGH CONFIDENCE IN WIND TREND.
* MEDIUM CONFIDENCE IN SHRA/TSRA OCCURRING LATE TONIGHT/EARLY SUNDAY
MORNING. LOW CONFIDENCE IN TIMING.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...VFR WITH CHANCE TSRA MONDAY NIGHT.
TUESDAY...VFR WITH CHANCE SHRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
MDB
&&
.MARINE...
257 AM CDT
HIGH PRESSURE SPREAD FROM HUDSON BAY SOUTH AND SOUTHWEST ACROSS LAKE
MICHIGAN CONTINUES TO PROVIDE NORTHEAST TO SOUTHEAST WINDS ACROSS
THE LAKE EARLY THIS MORNING. WINDS WILL TURN SOUTHERLY THIS
AFTERNOON AS THE RIDGE AXIS SHIFTS EASTWARD AND OUT OF THE AREA. LOW
PRESSURE ACROSS THE CANADIAN PRAIRIES WILL WEAKEN AS IT MOVES EAST
BUT THE PRESSURE GRADIENT BETWEEN THE RIDGE AND THE TROUGH WILL
BRING AN INCREASE IN SOUTHERLY WINDS TO NORTHERN SECTIONS OF THE
LAKE THIS EVENING. THE WEAKENED LOW WILL PASS TO THE NORTHEAST OF
LAKE MICHIGAN SUNDAY MORNING SHIFTING WINDS TO THE NORTHEAST ONCE
AGAIN DURING THE DAY SUNDAY. A RIDGE AXIS WILL THEN ARRIVE FROM THE
NORTH SUNDAY EVENING BRINGING WINDS MORE TO THE SOUTHEAST BUT
ANOTHER LOW WILL PASS TO THE SOUTH OF THE LAKE TUESDAY MORNING
BRINGING A RETURN OF NORTHERLY WINDS. HIGH PRESSURE IS EXPECTED TO
RETURN LATER TUESDAY AND REMAIN IN PLACE THROUGH THE END OF THE
WEEK.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1158 AM CDT SAT MAR 31 2012
...AVIATION SECTION UPDATED AT 1154 AM...
.UPDATE...
ISSUED AT 939 AM CDT SAT MAR 31 2012
A VERY WEAK PRESSURE GRADIENT WILL CONTINUE ACROSS WESTERN KANSAS
THROUGH THE MORNING HOURS. PRESSURES WILL FALL IN THE LEE OF THE
ROCKIES THIS AFTERNOON AS THE UPPER LEVEL TROUGH MOVING THROUGH
MANITOBA CONTINUES MOVING NORTHEAST AND THE STRONG UPPER LEVEL
TROUGH NEAR 130W REACHES THE WEST COAST. LOW LEVEL FLOW WILL
INCREASE FROM THE SOUTH AS THE ATMOSPHERE RESPONDS TO THE LEE
TROUGHING. TEMPERATURES THIS AFTERNOON MAY NOT BE QUITE AS WARM AS
ANTICIPATED DUE TO ANOMALOUSLY STRONG EVAPOTRANSPIRATION FROM
EARLY PLANT GROWTH AFTER THE HEAVY RAINFALL LAST WEEK. MINOR
DOWNWARD ADJUSTMENTS WERE MADE WHERE THE HEAVIEST RAIN FELL.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 300 AM CDT SAT MAR 31 2012
.SYNOPSIS...
ISSUED AT 300 AM CDT SAT MAR 31 2012
THE 00Z 300 HPA SYNOPTIC MAP SHOWS A STRONG 140 KT JET TRAVERSING ACROSS
THE PACIFIC NORTHWEST. ACROSS THE PLAINS, 45 TO 65 KT NORTHWESTERLY
FLOW WAS OBSERVED IN THE WAKE OF A DEPARTING TROUGH AXIS LOCATED ACROSS
THE EASTERN PLAINS/MIDWEST. THE 500 HPA MAP SHOWED THAT VERY COLD AIR
OF -38 DEG C WAS OBSERVED ACROSS VANCOUVER ISLAND. IN THE LOWER LEVELS
(700 AND 850 HPA), A DRY AIRMASS WAS OVER THE PLAINS, PARTICULARLY ACROSS
THE NORTHERN PLAINS. SURFACE ANALYSIS FROM HPC SHOWED A LOW PRESSURE
SYSTEM WITH ASSOCIATED COLD AND WARM FRONTS MOVING ACROSS THE CANADIAN
PRAIRIES. HIGH PRESSURE WAS OVER THE CENTRAL AND SOUTHERN PLAINS. DEWPOINTS
CONTINUED TO BE IN THE MODERATE LEVELS (FOR END OF MARCH) WITH LOWER
TO MID 50S DEG F DEWPOINTS ACROSS SW AND SC KANSAS.
THIS MORNING:
THE MAIN FORECAST CONCERN FOR THIS MORNING IN TERMS OF SENSIBLE WEATHER
IS IF FOG WILL DEVELOP OR NOT. THE 01Z AND 02Z HRRR RUNS WERE VERY AGGRESSIVE
IN DEVELOPING DENSE FOG ACROSS THE SW/W KANSAS. THE 04Z HRRR RUN HAS
BACKED OFF ON THIS WITH A SMALLER AREA OF DENSE FOG MAINLY ACROSS HAMILTON
COUNTY. WHAT IS INTERESTING IS THAT EVEN THOUGH THE MODEL DEVELOPS THE
FOG, THE MODELS ALSO HAS DOWNSLOPE SSW AS THE SFC. THIS IS NOT CONDUCIVE
FOR DENSE FOG FORMATION ACROSS MY COUNTY WARNING AREA. VSREF ALSO SHOWED
SOME HIGHER PROBABILITIES FOR LOWER VIS ACROSS THE AREA. OTHER MODEL
GUIDANCE IS LESS SUGGESTIVE FOR FOG FORMATION. DESPITE THIS, OBSERVATIONS
ACROSS OKLAHOMA SHOW SOME PATCHY FOG DEVELOP THIS MORNING SO I HAVE
DECIDED TO MEET THE MODELS IN BETWEEN AND INSERT PATCHY FOG ACROSS MY
WESTERN COUNTIES. DEWPOINTS ARE CURRENTLY IN THE 50S DEG F WITH UPSLOPE
SE/S WINDS SO THE POTENTIAL CANNOT BE COMPLETELY DISMISSED ATTM.
TODAY:
500 HPA FLOW WILL BECOME MORE MORE WESTERLY THROUGH TODAY, WHICH WILL
STRENGTHEN LEE TROUGHING. AS A RESULT, A WARM AIR ADVECTION PATTERN
WILL BE IN PLACE TODAY WITH TEMPERATURES WARMING WELL ABOVE NORMAL.
MID 80S DEG F ARE EXPECTED FOR HIGHS TODAY, WHICH IS ABOUT 20 DEGREES
ABOVE NORMAL. THIS WARM MARCH WE HAVE BEEN EXPERIENCING WILL END ON
A VERY WARM NOTE FOR THE LAST DAY IN THE MONTH. TODAY WILL BE PRECIPITATION
FREE AS A FAIRLY FLAT UPPER LEVEL RIDGE PREVAILS ACROSS KANSAS. I HAVE
GONE WITH SLIGHTLY COOLER TEMPERATURES TODAY (MID 80S DEG F VERSUS UPPER
80S DEG F) AS RECENT VERIFICATION PER BOI VERIFY SHOWS THAT MODELS ARE
SUFFERING A BIT OF WARM BIAS. SOUTHERLY WINDS OF 15 TO 20 KT ARE EXPECTED
THIS AFTERNOON AS MIXING INCREASES TO ABOUT 750 HPA AND SOME STRONGER
WINDS MIX DOWN.
TONIGHT:
THE LEE SURFACE TROUGH AXIS WILL MOVE SLIGHTLY EASTWARD TONIGHT AND
FRAGMENT TOWARDS SUNDAY MORNING. THIS WILL KEEP SOUTHERLY WINDS IN THE
FORECAST OVERNIGHT. DEWPOINTS IN THE 30S DEG F WEST TO 50S DEG F EAST
WILL KEEP OVERNIGHT LOWS ON THE MILD SIDE, PARTICULARLY ACROSS SOUTH
CENTRAL KANSAS. HAVE AROUND 60 DEG F TOWARDS KP28 (MEDICINE LODGE, KS)
AND COOLER MID 40S NEAR K3K3 (SYRACUSE, KS).
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 322 AM CDT SAT MAR 31 2012
MODELS REMAINING VERY CONSISTENT WITH PREVIOUS RUNS AND KEEP
SUNDAY SUNNY AND WARM . 850MB 00Z MONDAY TEMPERATURES STILL
SUPPORT HIGHS AROUND 90 DEGREES FOR MUCH OF SOUTHWEST KANSAS.
THESE HIGHS FOR THE FIRST OF APRIL COULD EASILY SET NEW RECORD
HIGHS IN A FEW LOCATIONS. A FEW RECORDS FOR APRIL FIRST ARE....88
DEGREES AT DODGE CITY, 87 AT GARDEN CITY AND 93 DEGREES AT
MEDICINE LODGE.
IN ADDITION TO THIS UNSEASONABLY WARM TEMPERATURES...LOW DEW
POINTS WILL BE SPREADING INTO PORTIONS OF WESTERN KANSAS BEHIND A
DRYLINE. THIS WILL RESULT IN AFTERNOON RELATIVE HUMIDITIES
BOTTOMING OUT IN THE 10 TO 15 PERCENT RANGE IN SEVERAL LOCATIONS.
GIVEN THESE LOW RELATIVE HUMIDITIES ALONG WITH GUSTY SOUTHWEST
WINDS DEVELOPING DURING THE AFTERNOON HAVE DECIDED TO CONTINUE THE
FIRE WEATHER WATCH ACROSS MUCH OF WESTERN KANSAS.
FOR EARLY NEXT WEEK...OUR NEXT UPPER LEVEL STORM SYSTEM IS STILL
FORECAST BY THE GFS, ECMWF, AND CANADIAN TO CROSS THE FOUR CORNERS
REGION SUNDAY NIGHT. BY MONDAY THIS SYSTEM WILL BEGIN TO DEEPEN
ACROSS NEW MEXICO WHERE IT WILL MOVE VERY LITTLE THROUGH TUESDAY.
AHEAD OF THIS SYSTEM A SOUTHEAST FLOW WILL DRAW MORE HUMID AIR
NORTHWARD TOWARDS SOUTHWEST KANSAS ON MONDAY. IN ADDITION 850MB
WARM AIR ADVECTION AND 850-700 FRONTOGENESIS WILL BE ON THE
INCREASE LATE IN THE DAY ALONG AND JUST BEHIND A COLD FRONT WHICH
WILL BE CROSSING SOUTHERN KANSAS/NORTHERN OKLAHOMA. GIVEN THIS
IMPROVING LIFT/MOISTURE AHEAD OF THE DEEPENING NEW MEXICO LOW WILL
BEGIN INCREASING CLOUD COVER AND PRECIPITATION CHANCES EARLY
MONDAY NIGHT. WINDS BEHIND THIS COLD FRONT MAY ALSO BE AN ISSUE
LATE MONDAY AND EARLY MONDAY NIGHT AS A TIGHT SURFACE PRESSURE
GRADIENT IS EXPECTED TO DEVELOP ACROSS PORTIONS OF SOUTHWEST
KANSAS IN RESPONSE TO AN AREA OF LOW PRESSURE DEEPENING ALONG THIS
FRONTAL BOUNDARY NEAR THE OKLAHOMA PANHANDLE.
TUESDAY THROUGH EARLY WEDNESDAY STILL APPEARS SOMEWHAT UNCLEAR
GIVEN THE DISAGREEMENT ON TRACK OF THIS UPPER LOW AS IT MOVES EAST
INTO THE PANHANDLE OF TEXAS. SINCE MODELS DO NOT HANDLE THESE
SYSTEM WELL, ESPECIALLY BEYOND 72 HOURS WILL FOLLOW THE GENERAL
TREND OF THE ALLBLEND THROUGH MID WEEK. HAVE THEREFORE INCREASED
PRECIPITATION CHANCES ACROSS SOUTHWEST KANSAS AND GIVEN THE CLOUDS
AND PRECIPITATION EXPECTED HAVE ALSO LOWERED TEMPERATURES TUESDAY
AFTERNOON.
BY LATE WEDNESDAY THIS UPPER LOW MOVE EAST ACROSS THE PLAINS. AS
THIS SYSTEM MOVES EAST OF WESTERN KANSAS THE SKIES WILL CLEAR AS
AN UPPER LEVEL SHORTWAVE RIDGE STARTS TO BUILD INTO THE ROCKIES
FROM THE WEST. AS THE WESTERLY DOWNSLOPE FLOW IMPROVES LATE WEEK
TEMPERATURES WILL REBOUND OUT OF 60S AND BACK INTO THE
70S...POSSIBLY A FEW 80S BY LATE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1154 AM CDT SAT MAR 31 2012
A WEAK LOW PRESSURE TROUGH EXTENDED FROM A SURFACE CYCLONE IN
NORTHEAST NEBRASKA ACROSS NORTHWEST KANSAS INTO EASTERN COLORADO
LATE THIS MORNING. A DEEP UPPER LEVEL TROUGH NEAR 130W WILL DIG INTO
THE WESTERN UNITED STATES TONIGHT, AND PRESSURES WILL FALL QUICKLY
IN THE LEE OF THE ROCKIES. LOW LEVEL WINDS WILL BE SOUTH 10-20 KNOTS
TONIGHT AND INCREASE TO 20-25 KNOTS WITH HIGHER GUSTS SUNDAY. PATCHY
THIN CIRRIFORM CLOUDINESS AOA 250 WILL CONTINUE TO DRIFT ACROSS THE
CENTRAL PLAINS THROUGH SUNDAY. DRY AIR ALOFT OVER SHALLOW BOUNDARY
LAYER MOISTURE WILL FAVOR SUFFICIENT RADIATIONAL COOLING OF THE
MOIST LAYER TO RESULT IN SOME VISIBILITY RESTRICTION IN MIST,
ESPECIALLY AT THE HYS AND DDC TERMINAL SITES. VISIBILITIES MAY BE
RESTRICTED TO 4-5 MILES AT DDC AND HYS AROUND SUNRISE SUNDAY WITH
PATCHY DENSER FOG IN SOUTH CENTRAL KANSAS AROUND PRATT AND MEDICINE
LODGE. OTHERWISE VFR CONDITIONS WILL PREVAIL THROUGH SUNDAY.
&&
.FIRE WEATHER...
ISSUED AT 300 AM CDT SAT MAR 31 2012
MARGINAL FIRE WEATHER CONDITIONS ARE EXPECTED SATURDAY AFTERNOON, AS
THE RELATIVE HUMIDITIES WILL NOT MEET RH CRITERIA. HAVE ADDRESSED THIS
CONCERN IN FWF. NEXT CONCERN IS CRITICAL FIRE WEATHER CONDITIONS EXPECTED
SUNDAY AFTERNOON. TEMPERATURES WILL BE VERY WARM AND WINDS WILL BE STRONGER
AS LEE CYCLOGENESIS STRENGTHENS ACROSS EASTERN COLORADO AND THE RELATED
PRESSURE GRADIENT INCREASES ACROSS THE REGION. THE FUEL STATUS PAGE
SHOWS THAT STEVENS AND MORTON COUNTY ARE A NO GO AS FUELS ARE NOT AT
THE APPROPRIATE LEVELS (NOTHING TO BURN?). THIS MAY HAVE TO BE ADDRESSED
BEFORE THE RFW IS ISSUED. OTHERWISE, AFTER COLLABORATION, IT WAS DECIDED
TO CONTINUE THE FIRE WEATHER WATCH FOR FAR WESTERN KANSAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 84 56 90 53 / 0 0 0 10
GCK 86 52 90 50 / 0 0 0 10
EHA 87 51 90 50 / 0 0 0 10
LBL 88 53 92 49 / 0 0 0 10
HYS 86 58 88 53 / 0 0 0 10
P28 83 60 88 58 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR KSZ061-062-074-075-084-085.
&&
$$
UPDATE...RUTHI
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....BURGERT
AVIATION...RUTHI
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
330 PM CDT SAT MAR 31 2012
.DISCUSSION...
CONSIDERABLE CLOUDINESS CONTINUES TO PLAGUE MUCH OF THE FA AT MID
AFTERNOON. ONLY THE FAR WESTERN COUNTIES HAVE NEAR FULL SUN. SOME
THINNING APPEARS TO BE OCCURRING OVER WEST CENTRAL WI. THE HRRR IS
TRYING TO SHOW CLEARING WORKING INTO FAR EASTERN MN AND WEST
CENTRAL WI BY THIS EVENING. HOWEVER...CLEARING OR NOT...THE
PRESSURE GRADIENT WILL WEAKEN TONIGHT WITH SATURATION DEVELOPING
DURING THE OVERNIGHT HOURS. THIS WILL LIKELY TO LEAD FOG AND MORE
STRATUS REFORMING. NAM BUFKIT HYDROLAPSE SHOWS A NICE INCREASE
JUST ABOUT EVERYWHERE TONIGHT DURING THE LATE NIGHT HOURS.
INDICATED AREAS OF FOG IN THE FORECAST...BUT DENSE FOG IS NOT OUT
OF THE QUESTION SUNDAY MORNING.
IN ADDITION...A WEAK SHORT WAVE IS PASSING BY EARLY THIS EVENING.
SEVERAL MODEL SOLUTIONS STILL TRY TO DEVELOP SOME SHOWERS OVER
CENTRAL MN AND PASS THEM ACROSS THE TWIN CITIES AND WEST CENTRAL
WI. CONFIDENCE IS NOT HIGH AND HAVE KEPT THE FORECAST DRY BUT THE
DIFFERENTIAL HEATING OCCURRING TO OUR WEST NOW IS A CONCERN. MUCH BETTER
INSTABILITY IS DEVELOPING OVER WESTERN IA ATTM AND THE LOW LEVEL
MOISTURE TRANSPORT INCREASES EARLY THIS EVENING BETWEEN KDSM AND
KMKE. SO SOME STORMS ARE POSSIBLE JUST TO OUR SOUTH OF OUR FA THIS
EVENING.
SUNDAY WILL BE THE WARMEST DAY OF THE NEXT SEVEN FOR MANY AREAS. MUCH
WILL DEPEND ON THE AMOUNT OF STRATUS AND FOG IN THE MORNING...BUT
WEST CENTRAL THROUGH SOUTH CENTRAL MN HAVE A REALLY GOOD CHANCE
OF SEEING HIGHS REACH WELL INTO THE 80S. READINGS IN THE 80S ARE
OCCURRING RIGHT NOW TO THE WEST AND SOUTH OF KFSD WITH H85
TEMPERATURES OF +16 TO +18 DEGREES C. SOUTHWEST AREAS OF MN WILL
BE SOME 2 TO 3 DEGREES C ABOVE THIS SUNDAY AFTERNOON. A HIGH NEAR
90 IS NOT OUT OF THE QUESTION AROUND LUVERNE AND PIPESTONE.
A LOW PRESSURE SYSTEM AND ASSOCIATED FRONTAL BOUNDARIES WILL MOVE
INTO THE FA SUNDAY NIGHT. ELEVATED INSTABILITY DEVELOPS BY EVENING
NORTH OF THE WARM FRONT ACROSS CENTRAL MN AND PUSHES INTO
NORTHWEST WI DURING THE NIGHT. LOW LEVEL MOISTURE TRANSPORT
INCREASES DRAMATICALLY ACROSS EAST CENTRAL MN AS THE LOW LEVEL
JET INCREASE TO 40 KNOTS. LAPSE RATES ARE BETTER THAN 6.5 DEG C/KM
ALONG WITH A FAVORABLE DIFFERENTIAL TEMPERATURE ADVECTION PATTERN.
THE CROSSOVER BETWEEN 850 AND 500 MB IS RATHER IMPRESSIVE BUT A
LITTLE NORTH OF OUR CWA. ALL OF THIS POINTS TO SOME STORMS
DEVELOPING ACROSS CENTRAL MN AND MOVING TOWARDS KDLH. A FEW STORMS
WITH LARGE HAIL MAY OCCUR.
THERE STILL REMAINS MODEL SPREAD FROM MONDAY THROUGH TUESDAY ON
MOVING THE LOW AND TRAILING COLD FRONT ACROSS THE FA. THE ECMWF
REMAINS THE SLOWEST WHILE THE NAM IS THE FASTEST. THE GEM AND GEFS
ARE PRETTY SIMILAR. TRIED TIMING PRECIPITATION BASED ON THIS
COMBINATION. THIS YIELDED LIKELY POPS OVER EAST CENTRAL MN MONDAY
AFTERNOON AND ACROSS PARTS OF WEST CENTRAL WI MONDAY EVENING. HIGH
TEMPERATURES ON MONDAY MAY BE WARMER THAN FORECAST FOR SOUTHEAST
AREAS OF THE FA IF THE CLOUDINESS/SHOWERS/THUNDERSTORMS DO NOT
DEVELOP AS FORECAST.
DRY WEATHER FORECAST IN THE WAKE OF THE FRONT FOR TUESDAY THROUGH
FRIDAY AS HIGH PRESSURE STALLS OVER THE WESTERN GREAT LAKES. HIGHS
DURING THE PERIOD FROM 55 TO 65 WITH LOWS FROM 35 TO 45. A PACIFIC
COLD FRONT IS THEN PROJECTED ACROSS THE REGION FOR NEXT SATURDAY.
HOWEVER...THE ECMWF REMAINS THE SLOWEST ON MOVING THE FRONT
THROUGH ALONG WITH WEAKENING THE SYSTEM AS IT APPROACHES. FOR
NOW...INDICATED ONLY A SMALL CHANCE FOR RAIN SHOWERS.
&&
.AVIATION.../18Z TAF ISSUANCE/
IFR/LIFR CEILINGS AND SOME BR REMAIN OVER MUCH OF THE AREA.
LIFTING/ERODING OVER FAR WESTERN AREAS. THIS TREND EXPECTED TO
CONTINUE THROUGH THE AFTERNOON...MAKING VFR OVER EAST CENTRAL MN
AFTER 22Z. WEST CENTRAL WISCONSIN TO REMAIN MVFR THROUGH 00Z. LIKELY
WILL SEE WHATEVER CLOUD IS LEFTOVER OVER THE EASTERN AREAS TO BUILD
SLIGHTLY WEST AGAIN TONIGHT...AS WEAK BOUNDARY DROPS INTO THE
REGION. FOG MAY BECOME AN ISSUE AGAIN OVERNIGHT AS WINDS BECOME
LIGHT IN AND NEAR THE VICINITY OF THE BOUNDARY. WILL MENTION IFR
CONDITIONS DEVELOPING INTO WESTERN WISCONSIN AND HINT ON THAT
POSSIBILITY AGAIN INTO MN PORTION MAINLY AFTER 06Z SUNDAY. SOME
INDICATION OF MID/HIGH CLOUDS COMING IN WITH BOUNDARY AND IT MAY
LIMIT FOG FORMATION SOMEWHAT. WILL HAVE TO MONITOR CLOUD TRENDS
INTO THE EVENING. EXPECT LOWER CLOUDS TO BREAK UP THROUGH 15Z
SUNDAY AND INCREASE SOUTHEAST WINDS AGAIN INTO THE AFTERNOON WITH
GUSTS 20-25 KNOTS POSSIBLE.
KMSP...MVFR CIGS LIFTING THIS AFTERNOON TO MVFR AFTER 22Z. EXPECT
SOME REDEVELOPMENT OF ADVECTION OF REMAINING CLOUD COVER TO THE EAST
BACK INTO THE REGION OVERNIGHT. WILL HAVE TO MONITOR CLOUDS TRENDS
INTO THE EVENING. BUFKIT PROFILES DO SUGGEST FOG FORMING OVERNIGHT
AS WELL...AND SOME MID/HIGH LEVEL CLOUDS POSSIBLE WHICH MAY LIMIT
FOG FORMATION SOMEWHAT. EXPECT ANY LOWER IFR/MVFR CEILINGS/VSBYS TO
MOVE OUT THROUGH 15Z WITH MID/HIGH LEVEL CLOUDS THEREAFTER AHEAD OF
NEXT BOUNDARY. SOUTHEAST TO EAST WINDS INTO THE EVENING BECOMING
LIGHT...AND INCREASING OUT OF THE SOUTHEAST AGAIN SUNDAY
MORNING...AND A BIT GUSTY INTO THE AFTERNOON.
OUTLOOK...
SUNDAY...BECOMING VFR BY LATE MORNING.
LATE SUNDAY NIGHT-MONDAY...MVFR POSSIBLE WITH SHRA/TSRA AS A FRONT
MOVES THROUGH.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
RAH/DWE
AREA FORECAST DISCUSSION
NWS DULUTH MN
126 PM CDT SAT MAR 31 2012
.AVIATION.../18Z TAF ISSUANCE/
WIDESPREAD LIFR TO IFR CONDITIONS WILL BE FOUND ACROSS THE REGION
TODAY...ALTHOUGH CONDITIONS COULD IMPROVE TO VFR IN SOME OF THE
WESTERN AREAS. THEN IT LOOKS LIKE WIDESPREAD MVFR TO IFR/LIFR
CONDITIONS WILL ONCE AGAIN DEVELOP AGAIN TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 635 AM CDT SAT MAR 31 2012/
AVIATION...12Z TAFS.
IFR/LIFR CIGS/VSBYS WITH FOG AT ALL SITES...AND -DZ AT KDLH. THE
FOG WILL PERSIST THROUGH 14Z-15Z WHEN APPROACHING SHORT WAVE AND
SFC FRONT WILL IMPROVE CIGS/VSBYS INTO MVFR RANGE. VCSH AT ALL
LOCATIONS EXCEPT KHYR AS SHORT WAVE/FRONT MOVE THROUGH THE FA
THROUGH 00Z SUNDAY. LLWS AHEAD OF THE FRONT. AFTER
FROPA...CIGS/VSBYS IMPROVE TO VFR.
PREV DISCUSSION... /ISSUED 331 AM CDT SAT MAR 31 2012/
SHORT TERM...
TODAY THROUGH SUNDAY AFTERNOON...
MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND THE PATCHY FOG
THROUGHOUT THE NORTHLAND WITH DENSE FOG ALONG THE NORTH SHORE AND
AROUND THE TWIN PORTS THIS MORNING...ALONG WITH RAIN SHOWERS MOVING
IN FROM THE NW TODAY...WITH PATCHY FREEZING DRIZZLE POSSIBLE IN THE
TIP OF THE ARROWHEAD BEFORE TEMPERATURES WARM LATE THIS MORNING.
UPPER LEVEL FLOW WILL REMAIN QUASI-ZONAL ACROSS MUCH OF THE CONUS
TODAY...BUT BECOME AMPLIFIED ON SUNDAY AS AN UPPER TROUGH DIGS
INTO THE WRN U.S. A WEAK 500MB S/W AND ASSOCIATED SFC TROUGH OVER
THE WRN DAKOTAS/SRN SASKATCHEWAN/MANITOBA REGION WILL TRACK TO THE
EAST THIS MORNING INTO WRN ONTARIO/NRN MN. RAIN SHOWERS WILL
ACCOMPANY THIS SYSTEM...MAINLY ACROSS THE NRN COUNTIES OF THE
FORECAST AREA. A FEW SHOWERS AND STORMS ARE ONGOING THIS MORNING
AROUND WINNIPEG...ALONG THE NRN EDGE OF A WARM/MOIST/UNSTABLE AIR
MASS BEING ADVECTED IN FROM THE SOUTH AND CO-LOCATED WITH A
NARROW BAND OF LOW LEVEL F-GEN. THIS PRECIP WILL TRY TO MOVE INTO
NE MN THIS MORNING...BUT WILL ENCOUNTER A MORE STABLE AIR MASS AND
DIMINISH IN INTENSITY THROUGH MID MORNING. THE OTHER CONCERN WITH
THIS PRECIP BAND WILL BE THE POTENTIAL FOR FREEZING DRIZZLE INTO
MAINLY LAKE AND COOK COUNTIES BEFORE 10AM. AS THE SURGE OF WARM
AIR ALOFT MOVES EWD OVER THE NEAR FREEZING SFC LAYER IN NE MN...THE
CHC FOR FREEZING PRECIP INCREASES. RUC SOUNDINGS AT ELY PRODUCE A
SATURATED THERMAL PROFILE NEAR FREEZING UP THROUGH 3000 FT...WITH
A VERY DRY LAYER ALOFT. SFC WINDS WILL EVENTUALLY VEER TO THE S/SW
AND USHER IN WARMER AIR FROM THE SOUTH BY LATE MORNING
TODAY...WHICH WILL ALLOW ANY PRECIP TO BECOME ALL LIQUID. LIQUID
PRECIP AMTS WILL RANGE FROM A TRACE UP TO A COUPLE TENTHS OF AN
INCH.
THE OTHER CONCERN IN THE SHORT TERM IS THE DENSE FOG AROUND THE
PERIPHERY OF LAKE SUPERIOR THIS MORNING. THE COMBINATION OF A
MOISTURE SFC LAYER...CONTINUOUS INFLUX OF COOL MOIST AIR FROM THE
EAST...AND A STRONG INVERSION AT THE TOP OF THE BOUNDARY LAYER ARE
ALL AIDING IN THE FORMATION AND PERSISTENCE OF FOG AROUND THE
NORTHLAND. WILL LIKELY SEE THE FOG CONTINUE TODAY AS LONG AS THE
WINDS REMAIN FROM THE EAST OFF THE LAKE. THE APPROACHING SFC
TROUGH SHOULD WIN OUT AND ALLOW WINDS TO VEER TO THE S/SW...WHICH
WILL HELP MIX DOWN SOME DRIER AIR ALOFT AND ERODE THE FOG LAYER BY
LATE MORNING. USUALLY TAKES LONGER THAN EXPECTED...SO MAY NEED TO
EXTEND DENSE FOG ADVISORY LONGER THAN 10AM. HOWEVER...FOR NOW WILL
KEEP WITH 10AM AS THE ENDING TIME.
THE DURATION OF THE EAST WINDS AND CLOUD LAYER WILL ALSO MITIGATE
HOW WARM TEMPERATURES GET TODAY. WITH CLOUD COVER EXPECTED THROUGH
A GOOD PORTION OF THE DAY...DECIDED TO DROP MAX TEMPS
TODAY...MAINLY IN NW WI. KEPT WITH 60S FOR INLAND LOCATIONS OF NE
MN...AND 40S AND 50S AROUND THE LAKE. TEMPS COOL INTO THE 30S AND
40S TONIGHT...AND WARM BACK INTO THE 60S AND LOWER 70S INLAND ON
SUNDAY...WITH 50S AROUND THE LAKE AS EAST WINDS RETURN. RIDGE OF
HIGH PRESSURE BUILDS IN ACROSS THE NRN PLAINS SUNDAY AS THE NEXT
SYSTEM PREPARES TO MOVE IN FROM THE SW SUNDAY NIGHT.
LONG TERM...
SUNDAY NIGHT THROUGH FRIDAY...
MODEL DIFFERENCES WITH THE MAGNITUDE OF THE FLATTENING/MOVING OF
THE UPPER RIDGE AND THE APPROACHING CLOSED UPPER LOW MOVING
THROUGH CANADA SUNDAY NIGHT. THIS ALSO PLAYS A ROLE IN THE AMOUNT
OF INSTABILITY FOR THUNDERSTORM DEVELOPMENT. USED A BLEND OF
QPF/POPS WITH THE MAJORITY OF THE THUNDERSTORMS HOLDING OFF UNTIL
AFTER 06Z MONDAY. THIS IS WHEN THETAE ADVECTION IS GREATEST. MODEL
DIFFERENCES CONTINUE ON MONDAY AS THE GFS IS QUICK TO MOVE A FRONT
THROUGH THE FA WHILE THE ECMWF/GEM/UKMET ARE THE SLOWEST. HAVE
SIDED WITH THE SLOWER APPROACH WHICH KEEPS THE INSTABILITY AXIS
NEARBY AND THE MENTION OF THUNDERSTORMS NEEDED. CONTINUED WITH THE
SLOWER MODELS MONDAY NIGHT AND LINGERED THE POPS. AN UPPER LEVEL
TROF MOVES THROUGH THE FA TUESDAY PUSHING THE PCPN E ALLOWING SFC
RIDGING TO BUILD IN. THE SFC HIGH BECOMES ANCHORED OVER THE
EASTERN GREAT LAKES TUESDAY NIGHT THROUGH FRIDAY KEEPING THE AREA
IN AN EASTERLY FLOW AND NO PCPN WITH THE DRY AIR FROM THE HIGH
LOCKED INTO THE FA.
AVIATION...06Z TAFS...
SKIES HAD CLEARED OVER KBRD...BUT MVFR CEILINGS HAVE ALREADY MOVED
BACK IN. IFR OR LOW MVFR CONDITIONS WILL PERSIST TONIGHT...WITH SOME
MIXED PRECIPITATION ACROSS THE FAR NORTH. DENSE FOG CAN BE
EXPECTED AROUND LAKE SUPERIOR. LATEST MODEL RUNS SUGGEST THE LOW
CEILINGS WILL BE SLOWER TO CLEAR ON SATURDAY...AND WE DELAYED THE
TIMING BY 1 TO 3 HOURS IN THE 06Z TAFS.
A SHORTWAVE AND TROUGH WILL ALSO BRING A CHANCE FOR SHOWERS
THROUGH SATURDAY...WITH THE BEST CHANCE ACROSS THE FAR NORTHEAST.
&&
.POINT TEMPS/POPS...
DLH 57 38 56 40 / 20 10 10 40
INL 60 33 60 40 / 40 10 10 30
BRD 66 43 72 51 / 10 10 10 20
HYR 58 40 68 47 / 10 10 10 30
ASX 56 39 57 43 / 10 10 10 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 2 PM CDT THIS AFTERNOON FOR MNZ021.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...BERDES
LONG TERM....DAP
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS GLASGOW MT
1019 AM MDT SAT MAR 31 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH MONDAY...
UPDATE...ISOLATED SHOWERS BEGINNING TO TAKE SHAPE ACROSS CENTRAL
MONTANA...AND ARE TRACKING TOWARD THE NORTHEAST. THE HRRR AND NAM
BUFFER SOUNDINGS ARE HINTING AT ISOLATED SHOWERS IMPACTING AREAS
SOUTH OF THE MISSOURI RIVER THIS AFTERNOON. BUT WITH SUCH DRY LOW
LEVELS ONLY SPRINKLES ARE POSSIBLE...THUS UPDATED TO PUT IN
MENTION OF SPRINKLES ACROSS THE SOUTHEAST. OTHERWISE LOOKS LIKE A HOT DAY
ACROSS NORTHEAST MONTANA. GILCHRIST
PREVIOUS DISCUSSION...SEMI PERSISTENT PATTERN WITH WEST COAST
TROF AND CENTRAL STATES RIDGE CONTINUES ALTHOUGH SHORTWAVE WILL BE
PUSHING THROUGH THE GREAT BASIN THIS WEEKEND.
TROF DIGGING ALONG THE WEST COAST...AMPLIFYING THE RIDGE OVER THE
PLAINS... AND PUSHING WARM AIR NORTHWARD. RESULT IS ANOTHER DAY
WITH TEMPERATURES APPROACHING RECORD LEVELS OVER EASTERN MONTANA.
WEAK HIGH PRESSURE SLIDING INTO NORTH DAKOTA AND LEE TROF
DEVELOPING IN CENTRAL MONTANA WILL TURN WINDS TO THE SOUTH TODAY.
DEEP MIXING IN THE WARM AIR MAY RESULT IN OCCASIONAL GUSTY WINDS
BUT WEAK WARM AIR ADVECTION AND LIFT NOT TOO FAVORABLE.
SHORTWAVE LIFTING TOWARD THE STATE TONIGHT WILL DEVELOP A
SURFACE LOW ALONG THE BOUNDARY IN CENTRAL MONTANA...PUSHING IT
EAST OVERNIGHT. THUNDERSTORMS POSSIBLE OVER CENTRAL MONTANA DURING
THE EVENING...TRANSITIONING TO SHOWERS OVERNIGHT AS THE LOW LIFTS
NORTHEAST.
WINDS INCREASE BEHIND THE SYSTEM ON SUNDAY...WITH COLD AIR
ADVECTION HELPING TO PUSH THEM TO THE SURFACE. CAA WILL ALSO DROP
TEMPERATURES ABOUT 10 DEGREES. COOLER WEATHER CONTINUES INTO
MONDAY AS UPPER TROF MOVES ACROSS THE STATE. TROF SPLITS FORMING
CUT OFF LOW OVER THE FOUR CORNERS...WHICH WILL KEEP MUCH MOISTURE
FROM SPREADING NORTHWARD. THUS CHANCES FOR SIGNIFICANT
PRECIPITATION VERY LOW INTO EARLY NEXT WEEK. EBERT
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...
ANOTHER WARM AND DRY UPPER RIDGE GIVING ABOVE NORMAL TEMPS FOR
TUE/WED. 850 MB TEMPS CLIMB TO AS HIGH AS 16C WED...THUS MORE 70S
FOR HIGHS.
THEN AN APPARENT LARGE SCALE PATTERN CHANGE TAKES PLACE AS A
SIGNIFICANT PART OF THE LARGE LOW IN THE E PACIFIC STARTS TO PUSH
E INTO THE INLAND WESTERN STATES. MODELS IN GOOD AGREEMENT UP TO
THIS POINT WITH THE PATTERN...AND THE LEADING COLD FRONT THAT
MOVES ACROSS OUR AREA THU. THIS FRONT USHERS IN A CHANGE TO COOLER
AND MORE UNSETTLED WEATHER...AT LEAST THRU SATURDAY...ASSOCIATED
WITH THE LOW PRESSURE TROUGH ALOFT THAT SEEMS TO STALL OVER THE
WESTERN STATES.
MODELS HAVE QUITE A BIT OF OUR AREA BELOW 0C AT 850 MB LATE IN THE PERIOD
...SO IT APPEARS THAT A LITTLE LATE NIGHT/EARLY MORN SNOW IS POSSIBLE.
SOME MODEL RUNS...ESPECIALLY THE ECMWF...HAVE ALSO BEEN SHOWING
THAT A SIGNIFICANT SURFACE WAVE MAY FORM ON THE FRONT OVER WY AND
MOVE NE INTO OUR AREA...AND OTHER MODELS HAVE HINTED AT THIS
TOO...BUT A LOT OF VARIATION ON WHETHER THIS WILL EVEN DEVELOP AT
ALL THOUGH...AS WELL AS LOCATION AFFECTED AND TIMING. AN OUTSIDE
CHANCE THIS COULD BRING A SIGNIFICANT RAIN/SNOW EVENT FRI OR SAT.
SINCE THIS IS QUITE A WAYS OFF WITH LOTS OF MODEL VARIATION...WILL
STICK WITH JUST SLIGHT CHANCE POPS FOR EACH PERIOD THU NIGHT AND
BEYOND UNTIL THIS BECOMES MORE OBVIOUS. SIMONSEN
&&
.AVIATION...
VFR WITH SCATTERED TO BROKEN LAYERS BETWEEN 7 AND 12K FT AGL TODAY
AND TONIGHT. ISOLATED SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE
AS WELL LATE THIS AFTERNOON OR EVENING ACROSS THE KGGW AND KOLF
TERMINALS. RSMITH
&&
.FIRE WEATHER...
DRY AND WARMER THAN NORMAL CONDITIONS CONTINUE ACROSS NORTHEAST
MONTANA TODAY. RELATIVE HUMIDITY EXPECTED TO DROP TO AROUND 20
PERCENT THIS AFTERNOON...AND ALTHOUGH WINDS WILL NOT BE AS STRONG
AS YESTERDAY...STILL COULD GET 10-20 MPH WITH HIGHER GUSTS ACROSS
THE WESTERN ZONES. THUNDERSTORMS ARE ALSO POSSIBLE IN CENTRAL
MONTANA BY LATE AFTERNOON...SPREADING EAST INTO THE EVENING...AS A
COLD FRONT APPROACHES THE REGION. ISSUED RED FLAG WARNING FOR THE
WESTERN ZONES DUE TO THE COMBINATION OF DRY FUELS...LOW RH...GUSTY
WINDS AND THUNDERSTORMS.
THIS FRONT WILL CROSS EASTERN MONTANA TONIGHT. SLIGHTLY COOLER
BUT WINDIER CONDITIONS ARE EXPECTED ON SUNDAY. RH WILL BE
IMPROVING WITH THE COOLER WEATHER...AND SHOWERS ARE POSSIBLE
BEHIND THE FRONT...SO WIDESPREAD CRITICAL FIRE CONDITIONS NOT
ANTICIPATED. EXCEPTION MAY BE ZONE 122 WHERE WARMER AND DRIER AIR
WILL PERSIST AND SHOWER POTENTIAL IS LESS.
&&
.HYDROLOGY...
THE YELLOWSTONE RIVER WILL BE RISING OVER THE NEXT COUPLE OF DAYS
THEN CRESTING AGAIN LATER IN THE WEEK. A MENTION IN THE HWO WILL
SUFFICE FOR NOW AS CRESTS WILL REMAIN BELOW FLOOD STAGE. JAMBA
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 10 PM MDT THIS
EVENING FOR MTZ134>137.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1239 PM CDT SAT MAR 31 2012
.AVIATION...VFR CONDITIONS ARE EXPECTED THROUGHOUT THE TAF PERIOD.
BOUNDARY LAYER MIXING WILL HELP INCREASE WIND SPEEDS TODAY TO NEAR
15 KTS WITH WIND GUSTS UP TO 20 KTS POSSIBLE. WHILE WINDS WILL
DECREASE SLIGHTLY OVERNIGHT...MIXING DURING THE DAY ON SUNDAY
WILL INCREASE WINDS AGAIN. A LOW PRESSURE SYSTEM WILL ALSO BEGIN
TO KNOCK ON OUR FRONT DOOR FROM THE WEST TOMORROW EVENING WITH A
STRONG PRESSURE GRADIENT ACROSS THE PLAINS JUST BEYOND THE TAF
PERIOD...SUGGESTING GUSTY WINDS DURING THE AFTERNOON TOMORROW. A
FEW HIGH CLOUDS WILL REMAIN THROUGHOUT THE PERIOD...WHILE A FEW
CUMULUS ARE POSSIBLE DURING THE AFTERNOON HOURS.
&&
PREV DISCUSSION... /ISSUED 330 AM CDT SAT MAR 31 2012/
SHORT TERM...TODAY THROUGH MONDAY NIGHT. THE PATTERN ALOFT
FEATURED SUBTLE RIDGING ACROSS THE CENTRAL PLAINS AND RIDGE IS
FORECAST TO EXPAND/BUILD THIS WEEKEND AS PACIFIC TROUGH REACHES THE
WESTERN CONUS. THIS WILL ALLOW A VERY WARM AIRMASS...ON THE ORDER
OF +3.3 STANDARD DEVIATIONS FOR H85 TEMPS...TO SETTLE ACROSS THE
CENTRAL PLAINS...AND FORECAST SOUNDINGS SUGGEST MIXING WILL BE
EVEN HIGHER THAN THIS LEVEL. RIDGE AXIS WILL SHIFT EASTWARD ON
SUNDAY AS UPPER TROUGH MOVES INTO THE ROCKIES WITH FLOW ALOFT
TRANSITIONING SOUTHWESTERLY. THE UPPER LOW IS FORECAST TO EMERGE
ONTO THE PLAINS MONDAY/MONDAY ALTHOUGH MODELS ARE NOT CONSISTENT
ON THE TRACK OF SYSTEM ATTM AND FOLLOWED CLOSER TO ENSEMBLES FOR
NOW.
HEADING INTO TODAY...MODELS HINT AT AN OUTSIDE CHCS FOR SOME LIGHT
CONVECTION PRIOR TO DAYBREAK IN PRESENCE OF SOME MID LEVEL WAA
ACROSS OUR NORTHERN COUNTIES. WILL MONITOR TRENDS OF THIS FOR THE
NEXT SEVERAL HOURS. THIS MORNING INTO EARLY AFTN A WEAK SURFACE
TROUGH WILL SLIDE EAST ACROSS NEBRASKA SHIFTING WINDS WESTERLY CAUSING
MOISTURE AXIS TO SHIFT EASTWARD. MODEL FORECAST SOUNDINGS SUGGEST
MIXING THIS AFTN AROUND H75 WITH WINDS AT THE TOP OF THE LAYER
ROUGHLY BETWEEN 11KTS AND 20KTS ACROSS OUR WESTERN CWA WHILE RH
VALUES DROP NEAR TO BELOW 20 PERCENT GENERALLY WEST OF HIGHWAY
281. LOCATIONS FROM ROUGHLY ORD TO LEXINGTON TO ARAPAHOE LOOK LIKE
THEY WILL MEET THE LOW RH CRITERIA FOR 3HRS WITH MAIN QUESTION
BEING WILL WINDS BE GUSTY ENOUGH FOR FIRE WEATHER HEADLINE.
SURFACE GRADIENT RELAXES SOME IN OUR WEST FOLLOWING BOUNDARY AND
MODELS SUGGEST SFC DPS MAY ACTUALLY RISE SOME IN AFTN AS WEST
WINDS TURN MORE SOUTHWESTERLY. FIRE WEATHER HEADLINE IS NOT A SLAM
DUNK DUE TO UNCERTAINTY IN WIND SPEEDS. HRRR WIND GUSTS DECREASE
ACROSS OUR WEST THIS AFTN AND THIS IS SUPPORTED BY 06Z NAM
SOUNDINGS WHERE WINDS AT THE TOP OF THE MIXED LAYER DECREASE
BETWEEN 21Z AND 00Z. GIVEN THE DECREASING WIND TREND WILL NOT GO
WITH HEADLINE ATTM AS OUR STRONGER WINDS WILL RESIDE EAST OF OUR
LOW RH AREA. THAT BEING SAID...DAY SHIFT WILL NEED TO CLOSELY
MONITOR FOR RED FLAG CONDITIONS.
HIGH TEMPERATURES THIS AFTERNOON LOOK TO BE NEAR OR AT RECORD
BREAKING LEVELS. RECORD FOR GRAND ISLAND TODAY IS 90F SET IN 1978.
RECORD FOR HASTINGS IS 89F SET IN 1946 AND RECORD FOR KEARNEY IS
88F SET IN 1946. CURRENT FORECAST HAS MAX TEMPS RIGHT AROUND THESE
RECORD READINGS AND MARCH WILL DEFINITELY END ON A HOT NOTE.
OVERNIGHT...THE SURFACE TROUGH DEEPENS ALONG THE HIGH PLAINS AND
MOISTURE MAKES A BETTER SURGE NORTH THRU KS INTO SOUTHERN NEBRASKA.
THE GFS MORE SO THAN THE NAM SUGGESTS POTENTIAL FOR SOME LOW CLOUD
DEVELOPMENT MAINLY ACROSS NC KS AND INCREASED CLOUD COVER AND
INCLUDED SOME PATCHY FOG FOR NOW.
ON SUNDAY...THE SURFACE LOW DEEPENS IN EASTERN COLORADO WITH
SOUTHERLY LLVL FLOW INCREASING ACROSS OUR CWA. MOISTURE AXIS ALIGNS
ACROSS THE EASTERN HALF TO TWO THIRDS OF OUR CWA WITH SFC DPS
PROGGED NEAR 60F IN OUR FAR EAST. THE UNSEASONALLY WARM/HOT AIRMASS
REMAINS IN PLACE ACROSS OUR REGION AND WE WILL SEE ANOTHER DAY OF
HIGHS IN THE UPPER 80S TO NEAR 90F WHICH ARE AGAIN NEAR OR ABOVE
RECORDS FOR THE FIRST OF APRIL. SUNDAY NIGHT...SFC COLD FRONTAL
BOUNDARY IN NW NEBRASKA ADVANCES SOUTHEAST INTO OUR CWA...REACHING
ALL BUT OUR SOUTHEAST ZONES BY MORNING. GFS SUGGESTS PCPN MAY
DEVELOP IN VCNTY OF FRONT MAINLY ACROSS OUR NORTHERN ZONES...HOWEVER
SREF AND OTHER MODELS ARE NOT OVERLY SUPPORTIVE OF THIS ATTM AND
WILL KEEP THINGS DRY FOR THE TIME BEING.
OF BIGGER CONCERN TOWARD DAYBREAK MONDAY AND THROUGH THE DAY ON
MONDAY IS THE INCREASING NORTH WINDS FOLLOWING FROPA. MODELS
INDICATE 6HR PRESSURE RISES BEHIND THE BOUNDARY IN EXCESS OF 10MB TO
OUR WEST ALONG THE HIGH PLAINS AND AROUND 8MB ACROSS OUR CWA MIDDAY
MONDAY. GRADIENT REMAINS TIGHT THROUGH THE DAY AND ALL INDICATIONS
FM MODELS SUGGEST WE WILL AT A MINIMUM REACH WIND ADVISORY CRITERIA
AND PORTIONS OF OUR WEST MAY BE NEAR HIGH WIND WARNING CRITERIA AND
WILL NEED TO MONITOR CLOSELY.
THE UPPER LOW SHIFTS EAST ONTO THE SOUTHERN PLAINS TOWARD THE TX/OK
PANHANDLES MONDAY NIGHT. GFS IS FARTHER NORTH WITH CENTER OF SYSTEM
THAN ECMWF AND HAVE PLAYED MIDDLE GROUND AND FOLLOWED CLOSER TO
ENSEMBLE SOLUTIONS FOR NOW. PCPN CHCS INCREASE MONDAY NIGHT FM
SOUTH TO NORTH IN INCREASING LIFT/DYNAMICS ASSOCIATED WITH UPPER
LOW. HAVE LEFT THUNDER OUT FOR NOW AS BETTER INSTABILITY REMAINS TO
OUR SOUTH BUT THIS MAY NEED TO BE ADJUSTED AS TRACK OF SYSTEM IS
REFINED.
LONG TERM...TUESDAY THROUGH FRIDAY. BIGGEST CONCERN IN THE
EXTENDED LOOKS TO BE THE TRACK OF THE UPPER LOW WHICH IS FORECAST
AFFECT OUR AREA MID WEEK.
LATEST RUN OF THE EXTENDED MODELS STILL SHOWING PLENTY OF
DIFFERENCES ON TRACK OF THE UPPER LOW. OPERATIONAL GFS IS ONE OF
THE QUICKEST SOLUTIONS AS IT TAKES THE 500 MB LOW FROM THE OK
PANHANDLE AT 12Z TUE TO THE SOUTHERN EDGE OF OUR CWA BY 12Z
WED...AND THEN PUSHES IT QUICKLY EAST TO THE NORTHEAST TIP OF
MISSOURI BY 12Z THU. OF COURSE THE PERTURBATION RUNS OF THE GFS HAVE
THE LOW ALL OVER THE PLACE. THE EC IS A LITTLE QUICKER THAN THE
PREVIOUS EC RUN AS IT MOVES THE LOW FROM ERN NEW MEXICO AT 12Z TUES
TO A LITTLE SE OF DDC AT 12Z WED...AND THEN INTO NW ARKANSAS BY 12Z
THU. THE GEM IS SIMILAR IN SPEED WITH THE SYSTEM BUT A LITTLE
FURTHER SOUTH WITH THE TRACK. ALL OF THE MODELS BRING THIS SYSTEM ON
SHORE TODAY AND THEN SPLIT THE ENERGY...TAKING SOME NORTH AND SOME
SOUTH. HOPEFULLY THE PICTURE GETS A LITTLE MORE CLEAR IN THE NEXT 24
HRS AS THE LOW MOVES ONTO THE CONUS. BIGGEST IMPLICATIONS FOR US
WILL BE DURATION OF THE PRECIPITATION. COULD SEE OFF AND ON RAIN
TUESDAY AND WED WITH A NORTHERN TRACK...OR THE NORTHERN PART OF THE
CWA MIGHT MISS OUT IF IT GOES SOUTH. IT DOES APPEAR THAT IT SHOULD
PUSH EAST ON THUR AS NEXT UPSTREAM SYSTEM IS SET TO MOVE INTO THE
WESTERN U.S. WHICH SHOULD KEEP THINGS PROGRESSIVE. INSTABILITY
LOOKS MARGINAL ON TUESDAY SO WILL KEEP THUNDER OUT FOR NOW.
OTHERWISE TEMPERATURES SHOULD STILL BE ABOVE NORMAL WITH HIGHS IN
THE UPPER 50S ON TUESDAY AND THEN CLIMBING BACK TO NEAR 70 FOR
THURSDAY AND FRIDAY. ALSO --- IT STILL DOES NOT LOOK LIKE WE WILL
GET BELOW FREEZING THROUGH THE UPCOMING WORKWEEK.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BISMARCK ND
346 PM CDT SAT MAR 31 2012
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT...
THE MAIN PROBLEM IN THE SHORT TERM WILL BE FIRE WEATHER HIGHLIGHTS
ON SUNDAY AND SUNDAY EVENING. UTILIZED A MODEL BLEND. THE NAM/GFS
WERE ON THE PROGRESSIVE SIDE WHILE THE ECMWF WAS THE SLOWEST OF
THE DETERMINISTIC MODELS. A BLEND SHOULD YIELD A FAVORABLE SOLUTION.
TONIGHT...WEAK HIGH PRESSURE OVER THE AREA WILL MOVE EAST AS LOW
PRESSURE CONTINUES TO BUILD OVER EASTERN MONTANA. NEARLY FULL SUN
ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON. WE WILL
SEE CLOUDS INCREASE IN THE WEST BY LATE AFTERNOON AS WARM
ADVECTION SPREADS EAST ACROSS NORTHERN AND CENTRAL NORTH DAKOTA.
MODELS BRING SOME SPOTTY QPF ACROSS THE NORTH TONIGHT. THE LATEST
HIGH RESOLUTION RUC SHOWS RETURNS MOVING WEST TO EAST ACROSS THE
NORTH THROUGH 06Z BUT DOES NOT INDICATE ANY MEASURED
PRECIPITATION. LATE TONIGHT THE ECMWF SHOWS SOME HEAVIER QPF OVER
THE NORTH CENTRAL...SO CANNOT RULE OUT SOME MEASURABLE
PRECIPITATION. ENDED UP KEEPING A MENTION OF SPRINKLES THIS
EVENING AND A SLIGHT CHANCE OF SHOWERS AFTER MIDNIGHT. ANY
ACCUMULATIONS ARE EXPECTED TO BE INSIGNIFICANT.
SUNDAY...A COLD FRONT WILL MOVE THROUGH WESTERN AND CENTRAL NORTH
DAKOTA. THE FRONT SHOULD MOVE INTO THE WEST AROUND MIDDAY AND
TRACK ACROSS THE LOCAL AREA BY LATE SUNDAY EVENING. THERMAL
RIDGING AHEAD OF THE FRONT SHOULD ALLOW FOR RECORD BREAKING WARMTH
ACROSS MUCH OF CENTRAL NORTH DAKOTA. SHOWN BELOW ARE THE FORECAST
AND RECORD HIGHS FOR SUNDAY FOR SELECT LOCATIONS ACROSS THE AREA.
SITE FORECAST RECORD YEAR
DICKINSON 79 74 1964
MINOT 76 72 1928
BISMARCK 84 75 1976
JAMESTOWN 78 78 1907
WILLISTON 72 72 1991
.SUNDAY NIGHT...WINDS WILL DIMINISH DURING THE EVENING. WITH UPPER
LEVEL ENERGY SPLITTING AND TRACKING NORTH AND SOUTH OF THE
CWA...AND SUBSIDENCE BEHIND THE FRONTAL BOUNDARY...ANY
PRECIPITATION IS EXPECTED TO BE LIGHT. THE ECMWF IS A LITTLE
WETTER...DUE TO A DEEPER TROUGH IN THE NORTHERN STREAM PUSHING
INTO THE NORTHERN PLAINS. FOR NOW WILL KEEP THINGS DRY.
AGAIN...ANY AMOUNTS WOULD BE LIGHT.
.LONG TERM...MONDAY THROUGH FRIDAY NIGHT...
AN UPPER TROUGH APPROACHES VIA THE NORTHERN STREAM MONDAY AND MODEL
DISCREPANCIES IN THE PRECIPITATION FIELD ARE FAIRLY SIGNIFICANT. THE
THE NAM AND GFS ARE SIMILAR IN GENERATING A NARROW STRIP OF VERY
LIGHT SHOWERS BETWEEN BISMARCK AND JAMESTOWN MONDAY MORNING. THE GEM
IS COMPLETELY DRY...WHILE THE ECMWF IS ADVERTISING WIDESPREAD LIGHT
RAIN THROUGHOUT THE DAY. THE MAIN DIFFERENCE LOOKS TO BE THE ECMWF
HOLDING BACK THE ENTIRE TROUGH FURTHER WEST ALLOWING MORE MOISTURE
FEED INTO NORTH DAKOTA VERSUS THE OTHER MODELS. FOR NOW HAVE
MAINTAINED A SLIGHT CHANCE OF SHOWERS FOR CENTRAL NORTH DAKOTA
MONDAY UNTIL BETTER AGREEMENT IS REACHED. IT WILL BE MUCH COOLER
MONDAY...BY 20 TO 25 DEGREES THAN SUNDAYS HIGH TEMPERATURES. THAT
ESSENTIALLY PUTS HIGHS IN THE LOWER TO MID 50S ACROSS WESTERN AND
CENTRAL NORTH DAKOTA MONDAY.
FOR TUESDAY THROUGH THURSDAY...TEMPERATURES BEGIN TO REBOUND THROUGH
THE PERIOD AS DRY AND WARMER WEATHER DEVELOP VIA A REX BLOCK/HIGH
OVER LOW PATTERN TRANSITIONING ACROSS THE NORTHERN PLAINS. EXPECT
PLENTY OF SUNSHINE...WITH THE WARMEST AIR...HIGHS AROUND
70F...ARRIVING THURSDAY AHEAD OF A COLD FRONT. A CHANCE OF SHOWERS
ARE FORECAST THURSDAY NIGHT THROUGH FRIDAY NIGHT AS A STRONG
BAROCLINIC ZONE SLOWLY MOVES FROM WEST TO EAST DURING THE DAY
FRIDAY.
FOR FRIDAY NIGHT INTO SATURDAY...THE GFS AND ECMWF IN GOOD AGREEMENT
WITH H85 TEMPS OF -4C TO -6C ACROSS CENTRAL AND NORTHERN NORTH
DAKOTA. BOUNDARY LAYER WINDS ARE ADVERTISED BETWEEN 30KT AND 40KT.
WILL NEED TO KEEP A CLOSE WATCH ON THIS FOR A POSSIBLE EARLY SPRING
SNOW/WIND EVENT.
&&
.AVIATION...THE LATEST SATELLITE IMAGERY SHOWS AN AREA OF SCT/BKN
LOW TO MID LEVEL CLOUDS BASED FROM 6500FT AGL TO 11000FT AGL. THIS
AREA WILL CONTINUE TO MOVE TOWARD KISN/KDIK/KMOT/KBIS THROUGH 00Z
SUNDAY. THIS IS ASSOCIATED WITH A WARM FRONT WHICH WILL MOVE THROUGH
OVERNIGHT. A VCSH IS WARRANTED OVER KISN AND KMOT TONIGHT. WINDS
WILL BECOME EAST TO SOUTHEAST WITH THE WARM FRONT OVERNIGHT AND
INCREASE TO AROUND 15KT. A COLD FRONT WILL THEN MOVE INTO THE
WESTERN AERODROMES KISN/KDIK AROUND 16Z SUNDAY. EXPECT A WIND SHIFT
TO THE WEST AND NORTHWEST AND INCREASING TO BETWEEN 20KT AND 30KT.
THE COLD FRONT WILL THEN SHIFT INTO CENTRAL NORTH DAKOTA...KMOT/KBIS
BY AROUND 21Z SUNDAY.
&&
.FIRE WEATHER...A COLD FRONT WILL PRODUCE GUSTY WEST TO NORTHWEST
WINDS AS IT MOVES THROUGH WESTERN AND CENTRAL NORTH DAKOTA ON
SUNDAY AND SUNDAY EVENING. A THICKNESS RIDGE AHEAD OF THE FRONT
COMBINED WITH COMPRESSIONAL HEATING ASSOCIATED WITH THE FRONT WILL
ALLOW TEMPERATURES TO RISE TO RECORD VALUES...AND ALLOW MINIMUM
HUMIDITIES TO DROP INTO THE TEENS IN THE AFTERNOON. FARTHER
WEST...TEMPERATURES WILL NOT WARM AS MUCH...BUT HUMIDITIES WILL
REMAIN QUITE LOW. FORECAST SOUNDINGS INDICATE SUSTAINED WINDS OF
AROUND 20 MPH WITH GUSTS UP TO 35 MPH ACROSS MOST OF WESTERN AND
CENTRAL NORTH DAKOTA. IT IS POSSIBLE WE COULD TRIM A FEW COUNTIES
IN THE NORTH AND EAST...FROM THE CURRENT WATCH...BUT WITH
UNCERTAINTY IN THE TIMING OF THE COLD FRONT...WILL ISSUE A RED
FLAG WARNING FOR THE SAME COUNTIES AS THE FIRE WEATHER WATCH. WE
DID EXTEND THE WARNING AN HOUR EARLIER TO CATCH THE STRONGER WINDS
COMING INTO THE WEST LATE IN THE MORNING...AND AN HOUR LATER TO
CATCH THE LOW HUMIDITIES AND BREEZY CONDITIONS HOLDING ON IN THE
EAST THROUGH MID EVENING. LATER SHIFTS CAN ALWAYS ADJUST AS
NEEDED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON CDT /11 AM MDT/ TO 10 PM CDT /9 PM
MDT/ SUNDAY FOR NDZ009>012-017>023-031>036-040>047-050.
&&
$$
SHORT TERM...TWH
LONG TERM/AVIATION...KS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
210 PM EDT SAT MAR 31 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION TODAY...PROVIDING COOLER
AND DRIER WEATHER. A FRONTAL BOUNDARY WILL DROP INTO OHIO ON
SUNDAY OFFERING A CHANCE OF SHOWERS AND THUNDERSTORMS. THE THREAT
FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO THE EARLY PART OF
THE WORK WEEK WITH THE FRONT REMAINING ACROSS THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
31.12Z KILN RAOB SHOWED AMPLE LOW LEVEL MOISTURE TRAPPED BENEATH
RATHER STRONG INVERSION CENTERED AROUND 900MB. WEAK COLD ADVECTION
BELOW THE INVERSION WILL CONTINUE THROUGH MUCH OF THE
AFTERNOON...SO HAVING DOUBTS THE DEGREE OF CLEARING ANY LOCATION
WILL SEE. TIME-LAGGED RUC SOUNDINGS FROM THE LAST 6 OPERATIONAL
13KM RUNS DEFINITELY TRENDING ON HOLDING LOW LEVEL MOISTURE IN
LONGER. 31.12Z RUC 950-900MB LAYER HUMIDITIES DO IMPROVE FOR SOME
CLEARING AFTER 20Z...MOST LIKELY A MANIFESTATION OF MUCH DRIER AIR
ABOVE THIS LAYER ADVECTING IN ON WLY FLOW FROM ILLINOIS /WHERE
CLEARING TAKING PLACE/...WITH MIXING/EROSION LIKELY CHEWING SOME HOLES
IN THE THICK LOW LEVEL STRATUS INTO MID/LATE AFTERNOON. EVEN WITH
THAT...FELT PRUDENT BASED ON CURRENT TEMPS AND BLEND OF HI-RES
SHORT TERM GUIDANCE /HRRR...WRF...LAMP...RUC/ TO DROP AFTERNOON
HIGH TEMPERATURES BY A GOOD 3 TO 5 DEGREES. SHOULD SEE THE VSBYS
SLOWLY IMPROVE THROUGH THE REST OF THE MORNING...AND THIS IS
ALREADY TRENDING IN 31.12Z - 31.14Z OBS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
UPPER LEVEL RIDGE BUILDING ACRS THE NATIONS MID SECTION WITH NWRLY
FLOW DOMINATING AND SURFACE RIDGE BUILDING INTO THE OHIO VALLEY BY
SUNDAY MORNING. ANY LINGERING CLOUDS WILL GIVE WAY TO CLEARING EARLY
TONIGHT WITH SOME INCREASE IN HIGH LEVEL CLOUDS LATE. EXPECT LOWS
FROM NEAR 40 NE TO THE MID 40S SOUTH.
EMBEDDED S/W IN THE NWRLY FLOW TO DROP SE THRU THE EASTERN GREAT
LAKES SUNDAY/SUNDAY NIGHT. ASSOCIATED BACK DOOR COLD FRONT TO DROP
SOUTH INTO OHIO SUNDAY AFTN. WL CONTINUE CURRENT TREND ALLOWING FOR
CHC POPS NORTH AND ONLY MENTIONING A SLIGHT CHC ACRS THE FAR S
LATE. THE INFLUENCE OF WAA AND SOME SUNSHINE AHD OF THIS FRONT
WILL ALLOW TEMPS TO WARM TO READINGS ABOUT 15 DEGREES ABOVE
NORMAL.
NUMERICAL MODEL SOLNS DIFFER ON WHERE THE BACK DOOR FRONT STALLS
OUT. EXPECT THIS FRONTAL BOUNDARY TO PUSH SW AND LOSE ITS IDENTITY
AS THE UPPER LEVEL RIDGE BUILDS INTO THE MS VLY. WL ONLY CONT
SLIGHT CHC POPS INTO SUNDAY EVENING AND THEN ALLOW FOR A DRY
OVERNIGHT. THE REMNANTS OF THE FRONTAL BOUNDARY STALLING OUT AND
BEGINNING TO PUSH BACK NE ON MONDAY. WITH A LACK OF UPPER SUPPORT
AND BEST INSTBY REMAINING TO OUR WEST. WL LIMIT POPS TO SLIGHT CHC
OF THUNDERSTORMS MONDAY AFTN ACRS THE SW. EXPECT MONDAYS HIGH TEMPS
TO BE 10 TO 15 DEGREES ABOVE NORMAL...RANGING FROM THE LOWER 70S
NE TO THE UPPER 70S SW.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MID LEVEL RIDGING WILL BE IN PLACE ACROSS THE OHIO VALLEY BY 12Z
MONDAY MORNING WITH A WEAKENING COLD FRONT TO OUR SOUTH. THE MODELS
ARE TRYING TO SHOW THIS FRONT LIFTING BACK TO THE NORTHEAST AS A
WARM FRONT THROUGH THE DAY ON MONDAY...BUT DISAGREE ON BOTH THE
TIMING AND THE STRENGTH OF THIS FEATURE. WILL THEREFORE JUST HANG ON
TO SOME LOWER CHANCE POPS MONDAY INTO MONDAY NIGHT.
THE MODELS ARE ALSO HAVING A DIFFICULT TIME RESOLVING THE SHORT
WAVE ENERGY MOVING OUT OF THE ROCKIES THROUGH MID WEEK. BOTH THE 12Z
NAM AND 12Z CMC ARE TRYING TO CLOSE OFF A 5H LOW AS IT MOVES INTO
THE TENNESSEE VALLEY WEDNESDAY INTO THURSDAY. HOWEVER...THE 00Z
ECMWF KEEPS THE CLOSED LOW WELL BACK TO THE SOUTHWEST AND AS A
RESULT IS MUCH SLOWER TO BRING RIDGING IN FROM THE WEST THROUGH
LATE IN THE WEEK. IN FACT...THE 00Z ECMWF KEEPS A FAIRLY DEEP TROUGH
OVER THE NORTHEASTERN UNITED STATES THROUGH THE LONG TERM PERIOD. IT
LOOKS LIKE THERE WILL BE A DECENT CHANCE OF SHOWERS AND
THUNDERSTORMS BY TUESDAY AS THE INITIAL ENERGY APPROACHES BUT THE
QUESTION WILL BE HOW LONG ANY TREAT WILL HANG AROUND INTO THE MIDDLE
PART OF THE WEEK. WITH THE CLOSED LOW OF THE GFS/CMC WOULD THINK ANY
LINGERING PCPN WOULD MAINLY REMAIN TO OUR SOUTHWEST. MEANWHILE...ANY
PCPN PUSHING DOWN THE BACK SIDE OF THE TROUGH OF THE ECMWF SHOULD
MAINLY REMAIN TO OUR EAST. WILL THEREFORE GO WITH A DRY FORECAST
FROM MID WEEK ON...BUT CONFIDENCE IS NOT VERY HIGH WITH THIS
FORECAST. OF COURSE TEMPERATURES THROUGH THE WEEK WILL ALSO BE
AFFECTED BY ALL OF THIS. WILL GENERALLY GO WITH A BLEND OF
PERSISTENCE AND THE MODELS BUT PERHAPS TREND A LITTLE MORE TOWARD
THE COOLER ECMWF...WHICH WOULD KEEP TEMPERATURES FAIRLY SEASONABLE
THROUGH THE WEEK.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
BKN-OVC MVFR CIGS WILL CONTINUE TO SLOWLY LIFT AND BEGIN
SCATTERING OUT BY EARLY EVENING. WILL BE A SLOW PROCESS
HOWEVER...AND CONFIDENCE IS NOT HIGH ON THESE CIGS BREAKING AS
SCHEDULED DUE TO AMPLE MOISTURE BELOW INVERSION. IF CLOUDS CAN
BREAK...THINK THERE IS GOOD POTENTIAL FOR FOG GIVEN COOL/MOIST LOW
LEVELS AND RECENT RAINS FOR MUCH OF THE AREA. WIND FIELD IS LIGHT
ESPECIALLY LATE EVENING THROUGH EARLY MORNING WITH SURFACE HIGH
OVERHEAD. HAVE MVFR VSBYS IN ALL TAF SITES WITH IFR VSBYS AT LUK. ON
SUNDAY...BOUNDARY LAYER FLOW TURNS SWLY AND INCREASES...BRINGING
WARMER/MORE UNSTABLE AIRMASS INTO THE REGION. CONTINUED MENTION OF
STORMS IN CVG TAF IN AFTERNOON GIVEN RAPID DESTABILIZATION...AND
OTHER TAF SITES WILL NEED TO MONITORED AS THE AFTERNOON PERIOD
WORKS INTO THE NEXT TAF ISSUANCE. WHILE COVERAGE OF STORMS SHOULD
REMAIN SCATTERED...A MID AFTERNOON TO MID EVENING PEAK IN COVERAGE
IS EXPECTED.
OUTLOOK...SCATTERED THUNDERSTORMS POSSIBLE MONDAY INTO TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...AR
NEAR TERM...BINAU
SHORT TERM...AR
LONG TERM...JGL
AVIATION...BINAU
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1152 AM CDT SAT MAR 31 2012
.DISCUSSION.../ISSUED AT 1152 AM CDT/
EXTENDED COVERAGE OF FOG THROUGH THE NORTHEASTERN THIRD OF AREA
THROUGH MIDDAY...BUT EVENTUALLY SHOULD SEE ENOUGH HEATING TO ERODE
ALL LOWER CLOUDS...BUT NOT WITHOUT THE EXPENSE OF CUTTING BACK ON
HIGHS IN THE EXTREME EAST/NORTHEAST. WATCHING PROGRESSION OF WEAK
DRY LINE/BOUNDARY THROUGH THE WESTERN CWA THIS MORNING...WHICH WILL
SHARPEN UP JUST SOUTH OF THE MISSOURI VALLEY THIS EVENING. THERE IS
A WEAK WAVE ENHANCING SOME MID TO HIGH CLOUDS ACROSS WESTERN INTO
CENTRAL SD AS OF MID MORNING...AND WILL BE INTERESTING TO SEE IF
THERE IS ENOUGH LIFT FROM THIS FEATURE AS IT SLIDES EAST/SOUTHEAST
INTO NORTHWEST IOWA LATE THIS AFTERNOON...AND BREAK WHAT LOOKS TO BE
CAP REMAINING NEAR THE WARM FRONT THROUGH NORTHWEST IOWA BY MID TO
LATE AFTERNOON. AT THIS TIME...JUST ENOUGH CAPPING TO THINK ANYTHING
WILL HAPPEN...BUT IN THE EVENT THAT LOW LEVEL MOISTURE POOLS JUST A
BIT MORE THAN EXPECTED AND EFFECTIVELY WEAKENS CAP...WILL MAINTAIN A
SMALLER AREA OF SLIGHT CHANCE POPS IN FAR SOUTHEAST. NEVERTHELESS...
WEAK SHEAR WOULD KEEP ANY ROGUE STORMS IN NON SEVERE MODES.
LOOKING AT TONIGHT...MAY VERY WELL END UP WITH ANOTHER EPISODE OF
FOG/LOW CLOUDS DEVELOPING OVERNIGHT NORTH OF THIS FRONTAL BOUNDARY.
/CHAPMAN
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
SOUTHEAST WINDS ADVECTING IN MOISTURE...COMBINED WITH NIGHTTIME
COOLING...HAS ALLOWED FOG AND LOW STRATUS TO FORM ACROSS SOUTHWEST
MINNESOTA AND NORTHWEST IOWA...WITH LIFR CIGS OF A COUPLE HUNDRED
FEET AND VISIBILITIES AT OR BELOW 2 MILES. RUC AND HRRR BACK THIS TO
THE WEST A BIT MORE THIS MORNING. THUS THINK IT WILL MAKE IT AS FAR
WEST AS ROUGHLY ALONG A SIOUX FALLS TO BROOKINGS LINE. AS THE SUN
RISES AND LOW LEVEL MIXING COMMENCES...SHOULD INITIALLY SEE THIS
REINFORCE THE LOW CLOUD DECK. HOWEVER WITH CONTINUED HEATING WE WILL
SEE THE CLOUDS BEGIN TO DISSIPATE FROM WEST TO EAST BY MID MORNING.
CURRENT THINKING HAS KFSD VFR BY AROUND 11AM. KSUX IS ALSO RIGHT ON
THE EDGE OF THE STRATUS DECK...BUT THINK THEY SHOULD REMAIN JUST TO
ITS SOUTHWEST...ALTHOUGH CAN NOT RULE OUT THEM BRIEFLY DROPPING TO
MVFR THIS MORNING.
ONCE THE LOW CLOUDS ERODE...VFR FLYING CONDITIONS SHOULD PERSIST
INTO TOMORROW MORNING. SOUTH SOUTHEAST WINDS WILL BRIEFLY TURN
NORTHERLY NORTH OF INTERSTATE 90 THIS AFTERNOON...BEFORE SWITCHING
BACK TO THE SOUTHEAST TONIGHT. WINDS ARE EXPECTED TO MAINLY REMAIN
BELOW 12 KTS THROUGH THE PERIOD. /CHENARD
&&
.PREV DISCUSSION.../ISSUED AT 700 AM CDT/
UPDATED TO ADD MORE FOG TO AREAS EAST OF I29 THROUGH MID MORNING.
FOG WILL BE DENSE IN PLACES. THIS SHOULD BURN OFF BY MID TO LATE
MORNING.
STRATUS HAS REFORMED ACROSS PORTIONS OF SOUTHWEST MINNESOTA AND
NORTHWEST IOWA WITH LOW LEVEL SOUTHEAST FLOW. REST OF CWA HAS PLENTY
OF HIGH CLOUDS STREAMING ACROSS THE REGION. SO WILL START OUT CLOUDY
TO MOSTLY CLOUDY WITH AREAS EAST OF I29 SLOWEST TO BREAK OUT DURING
THE MID TO LATE MORNING. THIS WILL SLOW DOWN WARMUP ACROSS EAST THIS
MORNING...BUT STILL SHOULD WARM INTO 70S EAST OF I29 AND 80 TO 85 TO
THE WEST.
WEAK SHORT WAVE IS PROGGED BY MODELS TO RIDE OVER TOP OF RIDGE THIS
AFTERNOON WITH WEAK QUASI WARM FRONT DEVELOPING OVER NORTHWEST IOWA.
SOME INSTABILITY DURING THE AFTERNOON ON EDGE OF MID CAP AND COULD
SEE AN ISOLATED THUNDERSTORMS ACROSS THE FAR SOUTHEAST AND HAVE
ADDED 20% THERE AFTER 20Z.
SHOULD CLEAR OUT ACROSS CWA TONIGHT WITH EVEN WARMER TEMPERATURES ON
SUNDAY AS H85 FLOW BECOME MORE SOUTHWEST ALLOWING FOR A LITTLE
BETTER MIXING. SO SHOULD SEE HIGHS IN THE 80S AND NEAR 90 ALONG THE
MISSOURI RIVER. SHOULD BE PLENTY OF RECORDS BEING SET THIS WEEKEND.
COLD FRONT WILL PUSH INTO WESTERN CWA LATE SUNDAY AFTERNOON...BUT
STRONG CAPPING WILL PROBABLY PREVENT ANY THUNDERSTORMS DEVELOPMENT
AHEAD OF FRONT.
WILL KEEP SMALL CHANCE OF THUNDERSTORMS SUNDAY NIGHT WEST OF I29
CORRIDOR JUST BEHIND FRONT WHERE COOLER MID LEVEL TEMPERATURES MAY
BE ENOUGH TO WEAKEN CAP.
INITIAL COOLING BEHIND THE FRONT WILL BE LAGGING AND WILL NOT REALLY
MAKE ITS PUSH UNTIL SUNDAY NIGHT...WITH WINDY AND COOLER CONDITIONS
ON MONDAY. WILL KEEP A LINGERING CHANCE OF THUNDERSTORMS ALONG AND
EAST OF INTERSTATE 29 ON MONDAY BEHIND THE FRONT...BUT DYNAMICS NOT
ALL THAT IMPRESSIVE TO GO MORE THAN 20 TO 30%.
WILL BE COOLER NEXT WEEK AS MORE OF AN EAST TO SOUTHEAST LOW LEVEL
FLOW OFF OF GREAT LAKES HIGH DEVELOPS. STILL ABOVE NORMAL
TEMPERATURES BUT HIGHS MAINLY IN THE UPPER 50S TO MID 60S TUESDAY
AND WEDNESDAY AND SLIGHTLY WARMER THURSDAY AND FRIDAY. WILL NEED TO
WATCH UPPER LOW OVER SOUTHWEST US AS IT MEANDERS ACROSS THE SOUTHERN
PLAINS MID WEEK. COULD SEE A FEW SHOWERS ACROSS FAR SOUTHEAST
WEDNESDAY OR THURSDAY...BUT FOR NOW WILL LEAVE DRY AS FLOW ALOFT
SHOULD KEEP STORM TO THE SOUTH.
LOOKS LIKE IT COULD BE MORE STORMY NEXT WEEKEND AS FAIRLY DECENT
WAVE MOVES EAST ACROSS THE NORTHERN PLAINS. MODELS NOT AGREEING ALL
THAT WELL WITH TIMING OF THIS FEATURE.
FIRE DANGER LIKELY TO BE VERY HIGH OR EXTREME WESTERN CWA TODAY AND
SUNDAY...BUT WINDS NOT STRONG ENOUGH TO WARRANT FIRE WEATHER WATCH.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
218 PM EDT SAT MAR 31 2012
.SYNOPSIS...
A WEAK COOL FRONT WILL SWEEP SOUTHEAST THROUGH THE MID APPALACHIAN
AND MID ATLANTIC REGION TODAY...ACCOMPANIED BY SCATTERED TO WIDELY
SCATTERED SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD
SOUTHEAST INTO THE AREA LATER THIS AFTERNOON...AND PERSIST
THROUGH SUNDAY...ENDING THE THREAT FOR RAIN AS SKIES GRADUALLY
CLEAR.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1010 AM EDT SATURDAY...
THE COLD FRONT IS JUST ENTERING OUR SOUTHEAST WEST VIRGINIA
COUNTIES AS OF 10 AM...AS INDICATED BY FALLING DEWPOINT
TEMPERATURES AND PRESSURE RISES. WITH DRIER AIR MAKING ITS WAY
IN...CLOUD COVER WILL GRADUALLY BEGIN TO BREAK UP ACROSS OUR AREA
THROUGH THE AFTERNOON. MAIN CHANGES TO THE EARLY MORNING FORECAST
WERE TO LOWER AFTERNOON TEMPERATURES A DEGREE OR TWO ACROSS THE
PIEDMONTS...AREAS THAT WILL STILL EXPERIENCE RAIN SHOWERS THROUGH
AROUND NOON.
AS OF 335 AM EDT SATURDAY...
WEAK COOL FRONT PROGRESSING SOUTHEAST OUT OF THE OHIO VALLEY WILL
SWEEP SOUTHEAST THROUGH THE MOUNTAINS THIS MORNING...AND CONTINUE
EAST MOVING THROUGH THE PIEDMONT COUNTIES THIS AFTERNOON. LATEST
RUN OF THE HIGH RESOLUTION WRFARL AND HRRR MODELS DOING A VERY
GOOD JOB OF DEPICTING THE MOVEMENT...TIMING...AND AREAL COVERAGE
OF LINEAR SCATTERED CONVECTION IN THE VICINITY OF THE FRONT...WITH
MORE STRATIFORM AREA OF PRECIPITATION ADVANCING NORTHEAST THROUGH
THE SOUTHERN COUNTIES WHERE ISENTROPIC LIFT IS MAXIMIZED.
EXPECT TO SEE SOUTHERN STRATIFORM AREA OF PRECIPITATION MAINLY
SOUTH OF HIGHWAY 460 TO MOVE EAST OF THE BLACKSBURG FORECAST AREA
BY MID MORNING AS BEST ISENTROPIC LIFT MOVES EAST OF REGION...AND
AS LOWER TROPOSPHERIC WINDS GRADUALLY VEER INTO MORE OF A
DOWNSLOPING COMPONENT AS SURFACE LOW PRESSURE MOVES EAST TO THE
DELMARVA AREA.
MEANWHILE...FURTHER NW NEAR THE SURFACE FRONT...PAST SEVERAL HOURS
OF SATELLITE PICTURES AND SURFACE OBSERVATIONS SHOWING A MARKED
DECREASE OF CONVECTIVE ACTIVITY ALONG/NEAR FRONT DUE TO LIMITED
FORCING AND NEGLIGIBLE THERMODYNAMIC SUPPORT. SOME STRAY
SHOWERS/ISOLATED STORMS MAY REACH THE WESTERN TIER COUNTIES
SHORTLY BEFORE/AROUND DAYBREAK...SUPPORTED BY AT LEAST SOME
LIMITED UPSLOPING ALONG THE WESTERN FLANKS OF THE
APPALACHIANS...BUT ANY REIGNITING ALONG THE FRONT WILL LIKELY COME
LATER IN THE AFTERNOON AFTER THERMODYNAMIC SUPPORT INCREASES...AND
BY THEN...FRONT/SURFACE TROF LIKELY TO SOUTH AND EAST OF THE
BLACKSBURG FORECAST AREA.
DESPITE ARRIVAL AND PASSAGE OF FRONT AND ASSOCIATED CLOUDS...LITTLE
CHANGE IN AIR MASS IS EXPECTED DURING THE DAY SINCE DEEPER COOL
AIR LAGS WELL BEHIND WIND SHIFT. COMBINATION OF LINGERING CLOUDS
IN UPSLOPE AREAS OF THE WEST AND AT LEAST A FEW DEGREE REDUCTION
IN 850 MILLIBAR TEMPERATURE SHOULD PREVENT AFTERNOON READINGS
FROM REACHING THOSE EXPERIENCED ON FRIDAY. HOWEVER...DOWNSLOPING
WINDS FOLLOWING PASSAGE OF FRONT/TROF MAY VERY WELL ALLOW FOR A WARMER
DAY ACROSS MUCH OF THE PIEDMONT. ALL AND ALL...EXPECT TEMPERATURES
TO CONTINUE TO BE 10-15 DEGREES ABOVE NORMAL FOR THE LAST DAY OF
THE MONTH...GENERALLY 60S ACROSS THE WESTERN MOUNTAINS TO NEAR 80
ACROSS THE PIEDMONT. THIS WILL ENSURE THAT MOST CLIMATOLOGICAL
SITES END UP BREAKING OR BEING IN THE TOP SEVERAL WARMEST MARCHES
ON RECORD.
DRY SURFACE RIDGE OF HIGH PRESSURE BUILDING IN FROM THE NORTH AND
WEST TONIGHT SHOULD ALLOW FOR CLEARING SKIES WITH GOOD RADIATIVE
COOLING POTENTIAL. READINGS SHORTLY BEFORE DAYBREAK ON SUNDAY
EXPECTED TO RANGE FROM THE MID 30S TO LOWER 40S IN THE
MOUNTAINS...WHERE SOME PATCHY FROST MAY OCCUR IN SOME OF THE
DEEPER MOUNTAIN VALLEYS...TO THE MID AND UPPER 40S ACROSS THE
PIEDMONT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM EDT SATURDAY...
ON SUNDAY...WE ARE EXPECTING HIGH PRESSURE TO SETTLE OVER THE AREA
BY THE MORNING. A STRONGER NOSE OF HIGH PRESSURE IS EXPECTED TO HEAD
SOUTH THROUGH THE GREAT LAKES AREA LATER IN THE DAY. THIS FEATURE
MAY PROMPT A BACK DOOR COLD FRONT INTO THE AREA...WITH THE POTENTIAL
FOR SOME ISOLATED SHOWERS ALONG IT LATE IN THE AFTERNOON INTO SUNDAY
EVENING. AS THE BACK DOOR FRONT CONTINUES SOUTH THROUGH THE AREA
SUNDAY NIGHT...ANTICIPATE ISOLATED COVERAGE ACROSS
WESTERN...NORTHERN...AND EASTERN SECTIONS OF THE REGION. COVERAGE
MAY SCATTERED OVER SECTIONS OF SOUTHEAST WEST VIRGINIA.
THIS FRONT WILL BECOME STALLED OVER THE WESTERN THIRD OF THE AREA BY
MONDAY MORNING. DURING THE DAY MONDAY...AN AREA OF LOW PRESSURE WILL
BE MOVING EASTWARD THROUGH THE CENTRAL PART OF THE U.S. WIND FLOW
IN ADVANCE OF THIS FEATURE WILL TURN SOUTHERLY ACROSS THE WESTERN
GULF OF MEXICO...AND ADVECT INTO OUR REGION FROM THE SOUTHWEST. THE
RESULT WILL BE INCREASING COVERAGE OF SHOWERS ALONG THE STALLED
FRONT THANKS TO THE INCREASED MOISTURE. THE FRONT ITSELF WILL ALSO
TAKE ON MORE OF THE NATURE OF A WARM FRONT AND HEAD ACROSS THE AREA
BY MONDAY NIGHT.
ON TUESDAY...THE LOW WILL HEAD EASTWARD NEAR THE PA/MD LINE AND ITS
ASSOCIATED COLD FRONT WILL SWEEP THROUGH THE AREA. WE ARE
ANTICIPATING INCREASED CHANCES OF SHOWERS AND THUNDERSTORMS DURING
THE DAY...ESPECIALLY ACROSS THE MOUNTAINS. AREAS ALONG AND EAST OF A
FARMVILLE TO DANVILLE LINE MAY NOT SEE ANY ACTIVITY UNTIL TUESDAY
EVENING. BY TUESDAY NIGHT... MOST OF THE PRECIPITATION WILL BE SOUTH
OF THE AREA IN ASSOCIATION WITH THE COLD FRONT. LINGERING SHOWERS
WILL STILL BE POSSIBLE ACROSS THE AREA...ESPECIALLY OVER SOUTHEAST
WV WHERE NORTHWEST FLOW UPSLOPE SHOWERS ARE EXPECTED.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
WITH THE COLD FRONT PASSING THROUGH OUR AREA ON TUESDAY NIGHT AND
WEDNESDAY MORNING...EXPECT ANOTHER LARGE DOME OF CANADIAN HIGH
PRESSURE TO BUILD INTO THE UPPER MIDWEST...BRINGING OUR TEMPERATURES
MUCH CLOSER TO NORMAL FOR THE FIRST WEEK OF APRIL. WITH HIGH
PRESSURE MAINTAINING ITS CONTROL THROUGH THE BEGINNING OF NEXT
WEEKEND...THE ONLY WEATHER CONCERNS WILL BE CHILLY OVERNIGHT
TEMPERATURES...WHICH MAY APPROACH FREEZING ACROSS PARTS OF SOUTHEAST
WEST VIRGINIA...AND MAY RESULT IN OVERNIGHT FROST ELSEWHERE ACROSS
THE MOUNTAINS.
&&
.AVIATION /17Z SATURDAY THROUGH WEDNESDAY/...
AS OF 130 PM EDT SATURDAY...
ALL AIRPORTS ARE REPORTING VFR CONDITIONS THIS AFTERNOON UNDER A
BROKEN LAYER OF STRATOCU...WITH BASES RANGING FROM 4KFT TO 7KFT...
AS AN EAST TO WEST COLD FRONT PUSHES SOUTH THROUGH THE FORECAST
REGION. SATELLITE IMAGERY HAS INDICATED SOME OF THE STRATOCU
BUBBLING UPWARD AHEAD OF THE FRONT WITH THE DAYTIME HEATING...AND
WOULD NOT BE SURPRISED IF A FEW SHOWERS...AND POSSIBLY
THUNDERSTORMS...DEVELOP BY MID AFTERNOON. ANY SHOWERS OR STORMS
WHICH DO DEVELOP WILL MOVE EAST OF OUR AREA BY LATE AFTERNOON OR
EARLY EVENING AS THE COLD FRONT EXITS TO THE SOUTHEAST.
A WEAK RIDGE OF HIGH PRESSURE WILL CONTINUE TO BUILD IN BEHIND THE
COLD FRONT THROUGH THE NIGHT. EXPECT VFR CONDITIONS TO PERSIST AT
ROA...LYH AND DAN. HOWEVER...CONCERNED WITH THE POSSIBILITY OF FOG
AND LOW CIGS FURTHER WEST. THE NAM FORECAST MODEL HOLDS LIGHT
NORTHWEST FLOW IN AT BLF OVERNIGHT...AND CONSIDERING THE RESIDUAL
LOW LEVEL MOISTURE FOUND ACROSS WEST VIRGINIA...BELIEVE THERE IS A
POSSIBILITY OF LOW CLOUDS REDEVELOPING BENEATH THE INVERSION OVER
THE AIRPORT AFTER MIDNIGHT. ALSO...WITH ADVECTION NEUTRALIZING SHORTLY
BEFORE SUNRISE ACROSS THE MOUNTAINS...INTRODUCED A PERIOD OF LOW
VISIBILITIES FOR BCB AND LWB FOR THE 01/09Z TO 01/13Z TIMEFRAME.
WITH SOUTHERLY FLOW TAKING OVER BY LATE SUNDAY MORNING...DAYTIME
HEATING WILL HELP MVFR AND IFR CONDITIONS IMPROVE RAPIDLY.
THE NEXT THREAT FOR WIDESPREAD FLIGHT RESTRICTIONS WILL OCCUR
LATE SUNDAY NIGHT OR ON MONDAY...POSSIBLY CONTINUING INTO THE MID
WEEK PERIOD AS ANOTHER RIDGE OF HIGH PRESSURE BUILDS SOUTHWEST OUT
OF NEW ENGLAND. UPSLOPING WINDS ACROSS THE EASTERN FLANKS OF THE
BLUE RIDGE...WITH WEAK SHORT WAVES AND MOISTURE STREAMING
NORTHEAST OVER A STALLED FRONT OVER/NEAR THE AREA...MAY SET THE
STAGE FOR MVFR (AND POTENTIALLY LOWER) FLIGHT RESTRICTIONS INTO
THE MID WEEK PERIOD...ESPECIALLY OVER/IN THE MOUNTAINS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WERT
NEAR TERM...NF/WERT
SHORT TERM...DS
LONG TERM...NF
AVIATION...NF/WERT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1236 PM CDT SAT MAR 31 2012
.SHORT TERM...THIS AFTERNOON
1131 AM CDT SAT MAR 31 2012
THE LATEST RUC AND NAM/WRF CONTINUE TO SUGGEST THAT THE LOW CLOUDS
WILL LINGER INTO TONIGHT. AS A RESULT THINKING THAT OUR HIGH
TEMPERATURE FORECAST IS WAY TOO GENEROUS. YESTERDAY UNDERNEATH
THESE CLOUDS TEMPERATURES STRUGGLED TO CLIMB INTO THE MID AND
UPPER 40S ACROSS WISCONSIN. EVEN IN SOUTHEAST MINNESOTA AND
NORTHEAST IOWA...THEY WERE ONLY ABLE TO CLIMB INTO THE MID 50S AND
THAT WAS DUE TO A BRIEF PERIOD OF PARTIAL SUNSHINE. THE LATEST RUC
IS ONLY SUGGESTING HIGHS IN THE 40S THIS AFTERNOON WHICH SEEMS
RATHER REASONABLE. SINCE THIS WOULD BE A CONSIDERABLE DROP IN OUR
FORECAST HIGH TEMPERATURES...DECIDED TO TAKE OUR EXISTING MAXIMUM
TEMPERATURE GRID AND BLEND IT WITH THE LATEST RUC. MOST LIKELY
STILL TOO WARM...BUT AT LEAST IT IS IN THE RIGHT DIRECTION.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
315 AM CDT SAT MAR 31 2012
QUIET WEATHER LOOKS TO DOMINATE THE ENTIRE LONG TERM PERIOD. A
CANADIAN HIGH PRESSURE RIDGE IS PROGGED BY THE 31.00Z
ECMWF/GFS/CANADIAN/UKMET TO BUILD INTO THE FORECAST AREA
TUESDAY...BEHIND MONDAY NIGHTS COLD FRONT...THEN ONLY DRIFT OFF TO
THE EAST THROUGH FRIDAY NIGHT. MEANWHILE...UPPER RIDGING LOOKS TO
BUILD ALOFT AHEAD OF DEEP TROUGHING DEVELOPING OVER THE WESTERN U.S.
THROUGH THE LONG TERM PERIOD. THIS SETUP FAVORS DRY CONDITIONS.
NOTE...THE 31.00Z GFS TRIES TO BRING THE CUT-OFF UPPER LOW IN NEW
MEXICO MONDAY NIGHT INTO IOWA BY 12Z THURSDAY...RESULTING IN SOME
SHOWERS OVER THE FORECAST AREA. THIS MODEL IS AN OUTLIER...EVEN
COMPARED TO ITS PREVIOUS RUN AND MOST OF ITS ENSEMBLE MEMBERS...AND
THEREFORE IGNORED AT THIS TIME. 850MB TEMPS WILL SLOWLY COOL...
DROPPING TO 2-4C FOR BOTH WEDNESDAY AND THURSDAY...BEFORE CLIMBING
BACK UP TO 4-6C ON FRIDAY AS THE SURFACE RIDGE MOVES EAST.
STILL...PLENTY OF SUN IS EXPECTED WHICH SHOULD HELP KEEP HIGHS ABOVE
NORMAL. CERTAINLY POSSIBLE TO SEE SOME FROST AT TIMES...ESPECIALLY
OVER CENTRAL WISCONSIN. IN ADDITION...MAY HAVE TO KEEP AN EYE ON
RELATIVE HUMIDITIES GIVEN WHAT LOOKS TO BE A BRIEF HUDSON BAY HIGH
SCENARIO...KNOWN TO MIX DEWPOINTS LOWER THAN FORECAST. HOWEVER...
WITH GREEN-UP WELL UNDERWAY...EVAPOTRANSPIRATION COULD KEEP
DEWPOINTS HIGHER MORE THAN WHAT WOULD NORMALLY OCCUR WITH A HUDSON
BAY HIGH.
&&
.AVIATION...THROUGH 18Z SUNDAY
1235 PM CDT SAT MAR 31 2012
EXTENSIVE IFR/MVFR CEILINGS PERSIST ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY AND GREAT LAKES EARLY THIS AFTERNOON. THE RUC
SUGGESTS THAT THESE CEILINGS WILL SLOWLY RISE INTO THE 1500 TO
2500 FOOT RANGE BY MID TO LATE AFTERNOON. THE NAM/WRF THEN
SUGGESTS THAT THESE CLOUDS WILL LIKELY LOWER AND BECOME LIFR/IFR
AFTER 01.06Z AND REMAIN THERE THROUGH AT LEAST 01.15Z. THE MODELS
THEN SUGGEST THAT THE CLOUDS MAY SCATTER OUT. HOWEVER WITH THE
925 MB OFF OF LAKE MICHIGAN...THERE IS SOME CONCERN THAT THESE
CLOUDS WILL LINGER MUCH LONGER THAN WHAT THE MODELS INDICATE...
THEREFORE...WENT MORE PESSIMISTIC WITHE CLOUD FORECAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
315 AM CDT SAT MAR 31 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...AJ
AVIATION...BOYNE
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1201 PM CDT SAT MAR 31 2012
.UPDATE...LOW CLOUD DECK CONTINUES TO HOLD STRONG ACROSS THE
REGION THIS MORNING. AREA RUC FORECAST SOUNDINGS AND TAMDAR
SOUNDINGS SHOWING THIS DECK TO BE ABOUT 1000 TO 2000 FEET THICK.
RUC/NAM SOUNDINGS AND HIGH RESOLUTION RAPID REFRESH MODEL SHOW
THIS LOW DECK SLOWLY MIXING OUT THIS AFTERNOON. HOWEVER...MID TO
HIGH CLOUDS ASSOCIATED WITH WARM AIR ADVECTION WILL CONTINUE TO
STREAM SOUTHEAST THROUGH THE REGION THROUGH THE AFTERNOON AND
EVENING.
THUS...HAVE GONE WITH MOSTLY CLOUDY WORDING THROUGH THIS
AFTERNOON...AND LIKELY THROUGH THE EVENING AS WELL. HAVE LOWERED
HIGH TEMPERATURES THIS AFTERNOON INTO THE MID TO UPPER 40S IN MOST
AREAS AS A RESULT OF THE CLOUDS. THIS MAY BE TOO WARM IN SOME
AREAS AND FURTHER ADJUSTMENTS DOWNWARD MAY BE NECESSARY.
12Z NAM/GFS MODELS SHOWING BULK OF POSSIBLE ELEVATED CONVECTION
LATER TONIGHT INTO SUNDAY MORNING STAYING JUST SOUTH OF THE AREA.
STILL HAVE 25 TO 30 KNOT WEST SOUTHWESTERLY LOW LEVEL JET POINTING
TOWARD THE AREA BY 06Z SUNDAY...THEN VEERS DUE WEST LATER TONIGHT.
NOT A LOT OF MOISTURE ADVECTION INTO THE REGION WITH THIS
FEATURE...BUT AREA FORECAST SOUNDINGS DO SHOW 500 TO 1000 J/KG
ELEVATED CAPE WITH DECENT EFFECTIVE LAYER SHEAR. LOW WET BULB ZERO
HEIGHTS SUGGEST SMALL HAIL IS POSSIBLE WITH ANY STORMS THAT DO
FORM AND MAKE IT INTO THE AREA.
HIGHEST POPS TONIGHT INTO SUNDAY MORNING LIKELY TO BE IN THE FAR
SOUTHERN COUNTIES...TAPERING DOWN TO THE NORTH. TEMPERATURES
LIKELY TO REMAIN NEARLY STEADY OR SLOWLY RISE WITH WARM AIR
ADVECTION CONTINUING. LIGHT WINDS AND LINGERING LOW LEVEL MOISTURE
SHOULD ALLOW FOR FOG DEVELOPMENT LATER TONIGHT/EARLY SUNDAY AS
WELL. DENSE FOG NOT EXPECTED WITH SOME HIGH CLOUDS LINGERING.
&&
.AVIATION/18Z TAFS/...MVFR/IFR CEILINGS ARE EXPECTED TO LINGER
INTO MID AFTERNOON ACROSS TAF SITES...BEFORE SLOWLY MIXING OUT
LATER THIS AFTERNOON. MVFR VISIBILITIES AT MADISON SHOULD ALSO
BECOME VFR DURING THIS TIME. VFR CEILINGS WITH MID TO HIGH CLOUDS
THEN EXPECTED THROUGH THIS EVENING...BEFORE SOME BREAKS OCCUR
LATER TONIGHT AND SUNDAY.
BEST CHANCES FOR ANY SHOWERS OR STORMS WOULD BE BETWEEN 06Z AND
12Z SUNDAY...BUT BEST CHANCES REMAIN SOUTH OF THE AREA...SO WILL
NOT MENTION IN TAFS AT THIS TIME.
LIGHT WINDS BETWEEN 09Z AND 14Z SUNDAY...WITH LINGERING LOW LEVEL
MOISTURE...MAY ALLOW FOR IFR/LIFR FOG FORMATION. SOME HIGH CLOUDS
LINGERING SHOULD PREVENT WIDESPREAD DENSE FOG. VFR CONDITIONS THEN
EXPECTED THROUGH THE REST OF SUNDAY. WINDS SHOULD BECOME EAST
NORTHEAST ON SUNDAY...AS WARM FRONT STAYS SOUTH OF THE AREA.
&&
.PREV DISCUSSION... /ISSUED 330 AM CDT SAT MAR 31 2012/
SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM.
LOW STRATUS AND PATCHY DRIZZLE WILL LINGER INTO THIS MORNING...GIVEN
AREA FORECAST SOUNDINGS SHOWING THE MOIST LAYER TRAPPED UNDER AN
INVERSION AROUND 2 THSD FT. NAM FORECAST SOUNDINGS SHOW SOME MIXING
DURING THE EARLY AFTERNOON ACROSS THE FORECAST AREA.
A WEAK SHORTWAVE WILL BE EXITING NORTHERN ILLINOIS AROUND 12Z/7AM.
A FEW SHOWERS FROM THIS SHOULD STAY JUST SOUTH OF THE ILLINOIS
BORDER.
850/700MB WARM AIR ADVECTION BEGINS TODAY WITH FORECAST SOUNDINGS
SHOWING SOME ELEVATED CAPE AROUND 190 J/KG LIFTED FROM AROUND
5 THSD FT. NO REAL SOURCE OF LIFT. 850 MB WINDS INCREASE EARLY
THIS EVENING AS A SHORTWAVE MOVES ACROSS NORTHERN LAKE SUPERIOR.
ELEVATED CAPE REACHES 1000 J/KG MAINLY LATE TONIGHT LIFTED FROM
AROUND 3 THSD FT. 850 MB DEWPOINTS INCREASE TO AROUND 10 CELSIUS
OVER THE SOUTHERN PORTIONS OF THE FORECAST AREA WITH SOME 850 MB
CONVERGENCE AROUND MIDNIGHT. 850 MB LIFTED INDEX VALUES REACH -3.5
CELSIUS. SURFACE WARM FRONT PUSHES NORTH INTO FAR NORTHERN
ILLINOIS. THIS WILL RESULT IN A CHANCE OF THUNDERSTORMS...
ESPECIALLY ACROSS SOUTHERN SECTIONS. WET BULB ZERO VALUES JUST
UNDER 8 THSD FT SO SOME SMALL HAIL WOULD BE POSSIBLE.
EXPECT HIGHS IN THE MID 40S NEAR LAKE MICHIGAN...BUT TEMPERATURES
MAY REACH NEAR 60 WEST OF MADISON.
SUNDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM.
THUNDERSTORM CHANCES CONTINUE ACROSS SOUTHERN WI SUN MORNING WITH
MODELS IN STRONG AGREEMENT OF A COMPACT SYSTEM ROLLING ACROSS THE
WI/IL BORDER. ECMWF/CANADIAN A LITTLE FURTHER SOUTH THAN THE
NAM/GFS SOLUTIONS.
00Z ECMWF HAS NOW TAKEN ON THE COOLER LOOK OF THE GFS ON SUN AND
MON...WITH 925MB TEMPS RANGING FROM AROUND 12C NEAR THE SHORE AND
18C IN SOUTH CENTRAL WI. NAM IS WARMER AND AGREED MORE WITH THE
12Z ECMWF. WENT WITH CONSENSUS OF TEMPS FOR MAX T ON SUN AND MON.
TIGHT TEMP GRADIENT BETWEEN LOW 60S ALONG THE LAKESHORE AND UPPER
70S IN SW FORECAST AREA.
THERE IS PLENTY OF UNCERTAINTY ABOUT WHETHER OR NOT CONVECTION COULD
BREAK OUT SUN NIGHT. THE 850MB BAROCLINIC ZONE SHOULD PROBABLY BE
NORTH OF THE FORECAST AREA/CWA/...WITH THE 925MB ZONE LAGGING
SLIGHTLY BEHIND IN OUR CWA. NOSE OF LOW LEVEL JET IS MORE UNCERTAIN.
FEEL THAT BETTER CHANCE FOR ELEVATED CONVECTION SHOULD BE IN
NORTHEAST CWA SO ADDED SLIGHT CHANCE. STEEP MID LEVEL LAPSE RATES
ALLOW FOR DECENT CAPE AROUND 800 J/KG. SHEAR IS WEAK IN THE MID
LEVELS.
THE CONVECTION POSSIBILITY CONTINUES INTO MONDAY BUT THERE IS
STILL UNCERTAINTY IN THE BAROCLINIC ZONE LOCATION AND LACK OF A
TRIGGER TO BEAT THE CAPPED ENVIRONMENT. DUE TO THE STRONG CAP PER
FCST SNDGS...CONVECTION WOULD HAVE TO BE ELEVATED AND HAVE
DEVELOPED UPSTREAM. SLIGHT CHANCE OF TSTORMS FOR MON.
BACKED OFF ON THE TSTORM CHANCES MON NIGHT AS MODELS HAVE SLOWED
DOWN THE TIMING OF THE COLD FRONT UNTIL LATE MON NIGHT/TUE
MORNING...ESPECIALLY THE ECMWF. THE NAM AND GFS ARE PERSISTENT IN
KEEPING THE 925MB BAROCLINIC ZONE ACROSS SOUTHERN WI MON AND MON
NIGHT WHILE THE ECMWF MOVES IT INTO CENTRAL WI.
LONG TERM...
TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM.
CONSENSUS OF MODELS SHOW MOST OF PRECIP EXITING SOUTHEAST WI TUE
MORNING. HOWEVER WITH THE LATEST 00Z ECMWF SLOWING DOWN THE
SYSTEM...POPS MAY HAVE TO BE INCREASED SLIGHTLY. ALSO ONLY MENTIONED
SHOWERS...BUT THUNDERSTORMS JUST AHEAD OF THE FRONT WILL BE
POSSIBLE.
TEMPS WILL BE COOLER ON TUE WITH HIGHS IN THE 50S TO LOWER 60S WITH
925MB TEMPS DROPPING BACK TO AROUND 5C. HIGH PRESSURE SINKING DOWN
INTO THE UPPER GREAT LAKES REGION WILL KEEP PRECIP CHANCES TO OUR
SOUTH AND TEMPS MILD IN THE 50S AND 60S THROUGH THE END OF THE WEEK.
A PERSISTENT EASTERLY COMPONENT OF THE WINDS OFF OF LAKE MICHIGAN
WILL KEEP TEMPS COOLER NEAR THE LAKESHORE.
AVIATION/12Z TAFS/...
EXPECT MAINLY IFR CEILINGS...WITH SOME LIFR EARLY THIS MORNING. THE
IFR CIGS WILL PERSIST THROUGH MUCH OF THE MORNING.
WINDS VEER SOUTHEAST ON SATURDAY AS THE SURFACE HIGH MOVES INTO
LOWER MICHIGAN THIS AFTERNOON. THE IFR CLOUD DECK SHOULD GRADUALLY
MIX OUT THIS AFTERNOON...MAYBE LATE MORNING OVER PORTIONS OF SOUTH
CENTRAL WISCONSIN. MAINLY VFR CONDITIONS EXPECTED LATER THIS
AFTERNOON.
A SURFACE WARM FRONT PUSHES NORTH INTO FAR NORTHERN ILLINOIS. THIS
WILL RESULT IN A CHANCE OF THUNDERSTORMS...ESPECIALLY ACROSS
SOUTHERN SECTIONS. SOME SMALL HAIL WILL BE POSSIBLE.
MAINLY VFR CEILINGS ALTHOUGH SOME IFR FOG WILL BE POSSIBLE.
MARINE...
EAST WINDS WILL GRADUALLY BECOME SOUTHEAST...AND WILL REMAIN BELOW
SMALL CRAFT CRITERIA. SOME FOG WILL BE POSSIBLE...ESPECIALLY
TONIGHT AS A WARM FRONT APPROACHES FROM NORTHERN ILLINOIS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...WOOD
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
SUNDAY THROUGH FRIDAY...MRC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1131 AM CDT SAT MAR 31 2012
.SHORT TERM...THIS AFTERNOON
1131 AM CDT SAT MAR 31 2012
THE LATEST RUC AND NAM/WRF CONTINUE TO SUGGEST THAT THE LOW CLOUDS
WILL LINGER INTO TONIGHT. AS A RESULT THINKING THAT OUR HIGH
TEMPERATURE FORECAST IS WAY TOO GENEROUS. YESTERDAY UNDERNEATH
THESE CLOUDS TEMPERATURES STRUGGLED TO CLIMB INTO THE MID AND
UPPER 40S ACROSS WISCONSIN. EVEN IN SOUTHEAST MINNESOTA AND
NORTHEAST IOWA...THEY WERE ONLY ABLE TO CLIMB INTO THE MID 50S AND
THAT WAS DUE TO A BRIEF PERIOD OF PARTIAL SUNSHINE. THE LATEST RUC
IS ONLY SUGGESTING HIGHS IN THE 40S THIS AFTERNOON WHICH SEEMS
RATHER REASONABLE. SINCE THIS WOULD BE A CONSIDERABLE DROP IN OUR
FORECAST HIGH TEMPERATURES...DECIDED TO TAKE OUR EXISTING MAXIMUM
TEMPERATURE GRID AND BLEND IT WITH THE LATEST RUC. MOST LIKELY
STILL TOO WARM...BUT AT LEAST IT IS IN THE RIGHT DIRECTION.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
315 AM CDT SAT MAR 31 2012
QUIET WEATHER LOOKS TO DOMINATE THE ENTIRE LONG TERM PERIOD. A
CANADIAN HIGH PRESSURE RIDGE IS PROGGED BY THE 31.00Z
ECMWF/GFS/CANADIAN/UKMET TO BUILD INTO THE FORECAST AREA
TUESDAY...BEHIND MONDAY NIGHTS COLD FRONT...THEN ONLY DRIFT OFF TO
THE EAST THROUGH FRIDAY NIGHT. MEANWHILE...UPPER RIDGING LOOKS TO
BUILD ALOFT AHEAD OF DEEP TROUGHING DEVELOPING OVER THE WESTERN U.S.
THROUGH THE LONG TERM PERIOD. THIS SETUP FAVORS DRY CONDITIONS.
NOTE...THE 31.00Z GFS TRIES TO BRING THE CUT-OFF UPPER LOW IN NEW
MEXICO MONDAY NIGHT INTO IOWA BY 12Z THURSDAY...RESULTING IN SOME
SHOWERS OVER THE FORECAST AREA. THIS MODEL IS AN OUTLIER...EVEN
COMPARED TO ITS PREVIOUS RUN AND MOST OF ITS ENSEMBLE MEMBERS...AND
THEREFORE IGNORED AT THIS TIME. 850MB TEMPS WILL SLOWLY COOL...
DROPPING TO 2-4C FOR BOTH WEDNESDAY AND THURSDAY...BEFORE CLIMBING
BACK UP TO 4-6C ON FRIDAY AS THE SURFACE RIDGE MOVES EAST.
STILL...PLENTY OF SUN IS EXPECTED WHICH SHOULD HELP KEEP HIGHS ABOVE
NORMAL. CERTAINLY POSSIBLE TO SEE SOME FROST AT TIMES...ESPECIALLY
OVER CENTRAL WISCONSIN. IN ADDITION...MAY HAVE TO KEEP AN EYE ON
RELATIVE HUMIDITIES GIVEN WHAT LOOKS TO BE A BRIEF HUDSON BAY HIGH
SCENARIO...KNOWN TO MIX DEWPOINTS LOWER THAN FORECAST. HOWEVER...
WITH GREEN-UP WELL UNDERWAY...EVAPOTRANSPIRATION COULD KEEP
DEWPOINTS HIGHER MORE THAN WHAT WOULD NORMALLY OCCUR WITH A HUDSON
BAY HIGH.
&&
.AVIATION...TODAY AND TONIGHT
605 AM CDT SAT MAR 31 2012
LOW STRATUS WILL PERIST AT THE TAF SITES THROUGH MID MORNING
PRODUCING CEILINGS IN THE 200 TO 700 FT RANGE AT KRST...AND IN THE
800 TO 1100 FT RANGE AT KLSE. IN ADDITION...VISIBLITIES WILL BE
REDUCED INTO THE 2 TO 3 SM RANGE AT KRST THROUGH 14Z. LOOK FOR
CONDITIONS TO GRADUALLY IMPROVE TO MVFR IN THE 14 TO 16 Z
TIMEFRAME AS THE STRATUS STARTS TO BREAK UP. CLOUD BASES WILL RISE
TO AROUND 1500 FT LATE THIS MORNING...BECOMING SCATTERED BY EARLY
THIS AFTERNOON. PLAN ON SOUTHEAST WINDS OF 6 TO 10 KTS THROUGH THE
DAY. A WARM FRONT WILL LIFT INTO NORTHERN IOWA AND SOUTHWEST
WISCONSIN THIS EVENING AND WILL BE THE FOCUS FOR SHOWER AND
THUNDERSTORM DEVELOPMENT. THE STRONGEST 850 MB MOISTURE TRANSPORT
WILL OCCUR ACROSS NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN. THE
SHOWERS AND THUNDERSTORMS SHOULD STAY SOUTH OF THE TAF SITES LATE
THIS EVENING INTO THE OVERNIGHT HOURS WITH VFR CONDITIONS
EXPECTED. WILL HAVE TO KEEP A CLOSE WATCH ON THE PROGRESSION OF
THE WARM FROM LATE THIS AFTERNOON INTO EARLY THIS EVENING. IF
THUNDERSTORMS DEVELOP...A FEW STORMS WILL BE CAPABLE OF PRODUCING
LARGE HAIL AND BRIEF HEAVY RAINFALL. LATEST GUIDANCE IS SUGGESTING
FOG DEVELOPMENT LATE TONIGHT INTO EARLY SUNDAY MORNING...MAINLY
ALONG AND NORTH OF THE WARM FRONT. CURRENT THINKING IS THAT THE
WINDS NEAR THE SURFACE WILL PROVIDE ENOUGH MIXING TO INHIBIT FOG
DEVELOPMENT. IF THE WARM FRONT ADVANCES FURTHER NORTH LATE
TONIGHT...AND DECOUPLING OCCURS...FOG COULD IMPACT THE TAF SITES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
315 AM CDT SAT MAR 31 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...AJ
AVIATION...WETENKAMP