Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 03/30/12
AREA FORECAST DISCUSSION
NWS TAUNTON MA
139 PM EDT WED MAR 28 2012
.SYNOPSIS...
A LOW PRESSURE WILL MOVES ACROSS NEW ENGLAND LATE TODAY INTO
THURSDAY BRINGING A CHANCE OF SHOWERS. COOL AND DRY WEATHER
FOLLOWS FRIDAY...WITH ANOTHER LOW PRESSURE LIKELY TO MOVE SOUTH
OF OUR REGION DURING THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
130 PM UPDATE...
HRRR MODEL IS DOING A GOOD JOB WITH CURRENT AREA OF SHOWERS WHICH
HAVE MOVED TO THE S COAST AS EXPECTED ASSOCD WITH THE LOW LEVEL
JET. STILL SOME LIGHTNING STRIKES ACROSS COASTAL CT AND THE RI
COASTAL WATERS BUT GREATER INSTABILITY AND MID LEVEL LAPSE RATES
ARE CONFINED FURTHER S OVER THE MID ATLC REGION. HRRR MOVES THESE
SHOWERS S OF THE COAST 18-20Z AND CANT RULE OUT A BRIEF TSTM ALONG
THE COAST AND ADJACENT WATERS AS THE SHOWERS MOVE THROUGH.
CLEARING HAS DEVELOPED ACROSS CENTRAL NY AND MAY SEE SOME SUNSHINE
THIS AFTERNOON...ESPECIALLY SW ZONES. HRRR IS SHOWING A FEW
SHOWERS DEVELOPING ACROSS W ZONES LATE TODAY ASSOCD WITH SOME
LEFTOVER ELEVATED INSTABILITY BUT STRONG MID LEVEL DRYING SHOULD
LIMIT CONVECTIVE POTENTIAL.
TEMPS ARE TRICKY TODAY AS WARM FRONT WILL BE APPROACHING FROM THE
SW BUT WILL LIKELY REMAIN TO THE S OR POSSIBLY GET CLOSE TO HFD-
WST LINE. TEMPS ACROSS N ZONES SHOULD REMAIN IN THE 40S...BUT
RISING INTO THE 50S ELSEWHERE. GUSTY SW WINDS WILL CONTINUE NEAR
THE S COAST ASSOCD WITH THE LOW LEVEL JET.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
BOTH THE NAM AND GFS EXHIBIT EXCELLENT CONVECTIVE INDICES FOR THIS
TIME OF YEAR. THE PROBLEM IS THE SUBSTANTIAL INVERSION WITH A BASE
AROUND 900 MB OR LOWER. NAM IS SLIGHTLY MORE AGGRESSIVE ADVERTISING
ELEVATED INSTABILITY ABOVE THIS INVERSION...BUT IT IS SHORT-LIVED
AND SHALLOW. KEPT THUNDER OUT OF THE FORECAST FOR NOW FOR THIS
EVENING. THIS POSSIBILITY WILL NEED TO BE WATCHED THOUGH.
THIS LOW PRESSURE AND ITS ASSOCIATED FRONTS EXPECTED TO MOVE
OFFSHORE WEDNESDAY NIGHT. HIGH PRESSURE OVER EASTERN CANADA STARTS
TO EXERT ITS INFLUENCE ON OUR WEATHER...BUT IT IS STILL FAR AWAY
MOST OF THURSDAY. EXPECTING LOW CLOUDS AND LINGERING SHOWERS
ACROSS EASTERN SOUTHERN NEW ENGLAND AS A RESULT.
A BLEND OF MAV/MET TEMPERATURES LOOKED REASONABLE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...
* DRY FOR THURS NIGHT INTO FRI NIGHT
* A WEATHER DISTURBANCE LOOKS TO STAY S OF THE REGION DURING THE WEEKEND
OVERVIEW...
FCST GUIDANCE CONSISTENCY FOR THE WEEKEND SYS HAS GENERALLY TRENDED
WITH A SOUTH COAST STORM...YET THE SPECIFICS IN BOTH TIMING AND
EVOLUTION ARE QUITE VARIED. SUBSEQUENTLY...LOW CONFIDENCE PREVAILS
FOR THE WEEKEND ONWARD. MASS FIELDS OF THE 28/0Z PACKAGE OF THE
GFS/NAM ARE BROUGHT INTO QUESTION...SUCH A WEAK TROF AXIS WITH
ATTENDANT SHRTWV ENERGY AND LESSER JET DYNAMICS PER GFS YIELDS A
ROBUST AND STRONG SYS? HAVE GREATER CONFIDENCE IN THE 28/0Z
CANADIAN/ECMWF PACKAGE WHICH EXHIBITS MASS FIELDS ONE WOULD EXPECT
WITH THE FCST MODEST S COAST STORM. NOT ABSOLUTELY SURE ON THE
PROGRESSIVENESS OF THE SYS. AO IS FCST TO BE POSITIVE WITH THE NAO
NEAR NEUTRAL...SO ITS NOT A CLEAR CUT PROGRESSIVE PATTERN OVER THE N
ATLANTIC. THERE IS A STRONG LOW ROTATING OVER ERN CANADA THAT COULD
BE PROBLEMATIC. A LOT OF QUESTIONS ARE STILL ON THE TABLE...AND THE
ASSOC PACIFIC ENERGY IS JUST COMING ONSHORE OF THE WRN CONUS. AM
EXPECTING THAT FCST GUIDANCE WILL EXHIBIT BETTER AGREEMENT WITH THE
NEXT MDL RUN OR TWO. OTHERWISE THE FCST SPECIFICS ARE TRULY
SPECULATIVE.
THURSDAY NIGHT...
SFC HIGH PRES RIDGE BUILDING EWD OUT OF CENTRAL CANADA WITH NW FLOW
AND DRIER AIR. NLY COMPONENT OF FLOW INITIALLY WILL ALLOW FOR
CONTINUED SHOWER ACTIVITY ALONG THE E SHORE AND ADJACENT WATERS /SST
TEMPS AROUND +7C WITH H85 TEMPS AROUND -8C...A DIFFERENCE BETWEEN
10-13C WARRANT CLOUDS AND PSBL SHOWERS/. YET ACTIVITY SHOULD BE
SHORT-LIVED AND PUSH EWD AS SFC WINDS EXHIBIT A MORE WLY COMPONENT
WITH TIME. SHOULD REMAIN MOSTLY CLEAR...BUT WITH NW WINDS REMAINING
MODEST...NOT THINKING A GOOD NOCTURNAL COOLING SCENARIO. MIN TEMPS
AROUND THE LOW 30S. MAIN COLD POOL ALOFT SHOULD BE ACROSS NEW
ENGLAND BY FRI MORN.
FRIDAY...
SFC HIGH PRES RIDGE IN CONTROL WITH NW FLOW WEAKENING THRU THE DAY.
MOSTLY CLEAR CONDITIONS SHOULD ALLOW FOR LOW-LVL MIXING OF DRIER AIR
TO THE SFC. LOOKING LIKE A DAY WHERE CONDITIONS MAY BE FAVORABLE FOR
FIRE WX SPREAD...YET LESSER WINDS WILL KEEP CONDITIONS FROM REACHING
RED FLAG CRITERIA. WILL KEEP THE PD DRY...WITH INCREASING MID LVL
CLOUDS AHEAD OF AN APPROACHING TROF SYS THRU THE ZONAL LONGWAVE
PATTERN. HIGHS AROUND THE UPR 40S WITH LOW 50S ALONG THE SRN TIER OF
NEW ENGLAND.
FRIDAY NGT INTO THE WEEKEND...
AS EMPHASIZED IN THE OVERVIEW...AM MORE INCLINED TO GO WITH THE
28/0Z CANADIAN/ECMWF PACKAGE AS THE FCST MASS FIELDS ARE MORE
IN-LINE WITH THE SFC OUTCOMES. IN FURTHER DETAIL...DEPENDING UPON
THE EVOLUTION AND PROXIMITY OF THE SFC LOW AND ATTENDANT MID-LVL
TROF WITH NEW ENGLAND...THERE ARE SOME NOTABLE DETAILS...
* ISENTROPIC UPGLIDE OF A WARM MOIST CONVEYOR BELT IS AMPLIFIED
ALONG WITH SW MID LVL FLOW IN RESPONSE TO H3 JET LVL DYNAMICS AND
DIV ALOFT
* LIFT OCCURS AHEAD OF THE SYS /SSW TO NE/ ACROSS THE SFC-H8 WARM
FRNT...THE STRONGEST OF WHICH IS ADJACENT AND N OF THE WARM FRNT
AROUND H8 WHERE ISENTROPIC UPGLIDE COUPLES WITH UPR LVL DIFLUENCE
PROMOTING DEEP LYR LIFT /SO AHEAD AND N OF THE SYS THERE WILL LIKELY
BE SOME GOOD MID-LVL FRONTOGENETICAL LIFT AND UPR LVL DIV TO PROMOTE
BANDING OF PRECIP/
* CONSEQUENTIALLY THERE WILL LIKELY BE AN OVERRUNNING WARM TONGUE OF
AIR OVER UNDERCUTTING SFC COLD AIR /AND NLY FLOW/ FROM THE COLD HIGH
PRES OUT OF CENTRAL CANADA...MAKING FOR SOME ISSUES WITH PRECIP TYPE
SO AN OVERRUNNING SITUATION ACROSS S NEW ENGLAND IS POSSIBLE...YET
AGAIN THE TIMING /DURING THE DAY OR NIGHT?/ AND PROXIMITY OF THE SFC
LOW /CLOSER TO S NEW ENGLAND WOULD PUSH GREATER PRECIP CHCS AND PSBL
WINTRY WX INTO INTERIOR NEW ENGLAND...OR IT MAY REMAIN OUTRIGHT DRY/
ARE KEY FOR THE FCST.
THE FCST AS IT STANDS RIGHT NOW IS A BROAD BLEND OF FCST GUIDANCE
WITH HEAVIER WEIGHT ON THE 28/0Z ECMWF/CANADIAN SOLN OVER MOST OF
THE WEEKEND AS SOLNS DIFFER ON THE TIMING OF THE STORM. FCST WILL BE
REFINED AS WE GET CLOSER IN TIME. CONFIDENCE AS IT STANDS IS THAT A
SYS IS EXPECTED TO SWEEP S OF NEW ENGLAND...THAT SEEMS CERTAIN...
BUT SPECIFICS ARE VERY UNCERTAIN AS OF NOW.
BEYOND THE WEEKEND...
WHILE A BRIEF PD OF HIGH PRES IS EXPECTED IN WAKE OF THE STORM...IT
APPEARS THE RETURN OF WARM WX IS IN THE CARDS WITH AN ATTENDANT WARM
FRNT INTO MIDWEEK. BUT THIS MAY BE SHORT-LIVED AS A COLD FRNT SWEEPS
THRU THE RGN TOWARDS THE LATER HALF OF THE WEEK. A FAIRLY UNCERTAIN
FCST INTO THE END OF NEXT WEEK.
&&
.AVIATION /17Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
THROUGH 00Z...
MODERATE TO HIGH CONFIDENCE. VFR CIGS WILL CONTINUE WITH AREAS OF
MVFR VSBYS IN SHOWERS ALONG THE S COAST THROUGH 19-20Z. SW WIND
GUSTS TO 25 KT DEVELOPING ALONG THE S COAST.
TONIGHT...
MODERATE CONFIDENCE. EXPECT VFR CIGS TO LOWER TO MVFR
OVERNIGHT...MAINLY ACROSS N ZONES WHERE A FEW SHOWERS POSSIBLE WHILE
REMAINING VFR CLOSER TO THE S COAST. WINDS SHIFTING TO NW LATE
TONIGHT.
THURSDAY...
MODERATE CONFIDENCE. AREAS OF MVFR CIGS IN THE
MORNING...ESPECIALLY E OF CT VALLEY. THEN CIGS LIFTING TO VFR IN
THE AFTERNOON. A FEW SHOWERS POSSIBLE E NEW ENG.
THURSDAY NIGHT...
MODERATE TO HIGH CONFIDENCE VFR.
KBOS TERMINAL...
MODERATE CONFIDENCE IN TAF. MAY SEE A PERIOD OF MVFR CIGS
1500-2500 FT DEVELOPING OVERNIGHT...MAINLY AFTER 06Z AND
CONTINUING INTO THE MORNING. THEN LIFTING TO VFR DURING THE
AFTERNOON.
OUTLOOK...FRIDAY THROUGH SUNDAY...
FRIDAY... MODERATE CONFIDENCE VFR.
FRIDAY NIGHT INTO THE WEEKEND...
LOW CONFIDENCE. STORM WILL SWEEP S OF NEW ENGLAND LENDING TO PSBL
MVFR-IFR CIGS AND VSBYS. SPECIFICS DEPEND UPON THE TIMING AND
PROXIMITY OF THE SFC LOW WHICH IS UNCERTAIN AS OF NOW. SHOULD SEE
INCREASING ELY FLOW IN RESPONSE TO DEEPENING SYS TRACKING S OF NEW
ENGLAND...BECOMING NWLY AND REMAINING MODEST AS THE SYS EXITS E.
PSBL RAIN/SNOW SHOWERS...MORESO FOR THE S COAST...SO HAVE GREATEST
CONFIDENCE IN IMPACTS FOR THE SRN TERMINALS.
&&
.MARINE...
ANOTHER PERIOD OF GUSTS TO 25 KT IS LIKELY ACROSS THE SOUTH
COASTAL WATERS THIS AFTERNOON AS A LOW-LEVEL JET MOVES EAST
ACROSS THE WATERS. EXPANDED THE SCA TO INCLUDE NARRAGNSETT
BAY...BUZZARDS BAY AND MVY SOUND.
WINDS SHIFT TO THE NW AFTER MIDNIGHT TONIGHT BEHIND A COLD
FRONT.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY NIGHT INTO FRIDAY...
NW FLOW REMAIN BLUSTERY OVER THE WATERS WITH SCTD RAIN AND PSBL SNOW
SHOWERS. SEAS ALONG THE OUTER WATERS TO REMAIN AROUND 5 FT INTO THE
LATE FRI PD BY WHICH TIME WINDS AND SEAS SHOULD SUBSIDE.
FRIDAY NIGHT INTO THE WEEKEND...
STORM SYS IS EXPECTED TO BECOME ORGANIZED AND DEEPEN AS IT PASSES
THRU THE MID-ATLANTIC AND OFFSHORE JUST S OF NEW ENGLAND. ELY FLOW
WILL INCREASE IN RESPONSE AND SHOULD SEE SEAS BUILD ALONG THE S
COAST ACCORDINGLY. NW FLOW IN WAKE OF THE SYS AS IT DEPARTS. A GREAT
DEAL OF UNCERTAINTY IN THE FCST AS THE SPECIFICS OF BOTH THE TIMING
AND PROXIMITY OF THE SFC LOW TO S NEW ENGLAND ARE STILL IN QUESTION.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR
ANZ232>234-236.
SMALL CRAFT ADVISORY UNTIL NOON EDT THURSDAY FOR ANZ235-237.
SMALL CRAFT ADVISORY FROM 2 AM TO 8 PM EDT THURSDAY FOR ANZ250.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THURSDAY FOR ANZ254.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THURSDAY FOR ANZ255-256.
&&
$$
SYNOPSIS...BELK/SIPPRELL
NEAR TERM...KJC
SHORT TERM...BELK
LONG TERM...SIPPRELL
AVIATION...KJC/SIPPRELL
MARINE...BELK/KJC/SIPPRELL
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1107 AM EDT WED MAR 28 2012
.SYNOPSIS...
LOW PRESSURE APPROACHES TODAY AND MOVES TO THE EAST TONIGHT. AN
ASSOCIATED COLD FRONT WILL FOLLOW. HIGH PRESSURE BUILDS IN FOR
THURSDAY NIGHT INTO FRIDAY. LOW PRESSURE APPROACHES THE REGION
FRIDAY NIGHT...TRACKING JUST SOUTH OF THE AREA. HIGH PRESSURE
BUILDS IN FOR SUNDAY. A WARM FRONT LIFTS NORTH OF THE REGION
SUNDAY NIGHT. COLD FRONT MOVES THROUGH MONDAY NIGHT...WITH HIGH
PRESSURE BUILDING IN FOR MID-WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST GENERALLY ON TRACK. MADE ADJUSTMENTS TO HOURLY DEW POINTS
WHICH HAVE RISEN SLIGHTLY QUICKER THAN FORECAST. ALSO FINE TUNED
THE POPS AND WX TO BETTER REFLECT TIMING OF SHOWERS. SOME SHOWERS
WILL HAVE EMBEDDED THUNDER WITH IT SO WILL INCLUDE CHANCE OF
THUNDER EVERYWHERE IN THE GRIDS.
OTHERWISE...WARM AIR ADVECTION UNDERWAY AS SFC HIGH PRESSURE HAS
PASSED WELL TO THE SOUTH. RIDGING ALOFT...WITH RIDGE AXIS TO THE
EAST...OCCURRING AHEAD OF DIGGING TROUGH TRAVERSING ACROSS THE
GREAT LAKES REGION. SFC LOW PRESSURE MOVES ACROSS THE SAINT
LAWRENCE VALLEY AND PASSES ACROSS NEW ENGLAND THIS AFTERNOON.
LOOKING AT SREF/GEFS DATA...PROBABILITY OF AT LEAST MEASURABLE QPF
HIGHER THAN MET MOS SUGGESTS. PW VALUES INCREASE AHEAD OF THE COLD
FRONT THIS AFTERNOON...WITH THETA E RIDGE EXTENDED ACROSS THE AREA
AND LAYER PW PERCENTAGE WELL ABOVE NORMAL. SOME JET SUPPORT ALOFT
FOR POSSIBLE CONVECTION.
DEPENDING ON ANY SUNSHINE...MOS NUMBERS APPEAR REASONABLE WITH
60S WEST...AND 50S EAST DUE TO SW FLOW OFF COOL WATER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
SHORTWAVE PIVOTS ACROSS THE NORTHEAST TONIGHT AND THURSDAY...WITH
MUCH DRIER AIR USHERED IN IN DEEP NW FLOW. SFC LOW PRESSURE TRACKS
OFF THE NEW ENGLAND COAST TONIGHT...DRAGGING A COLD FRONT THROUGH.
WEAK UPPER SUPPORT/ASSOC LIFT FOR WIDESPREAD SHOWERS...AND DRY
AIR SHOULD KEEP ANY PRECIP POTENTIAL TO A MINIMUM TONIGHT INTO
EARLY THURSDAY. IT WILL BE COLDER (ALTHOUGH STILL ABOVE
NORMAL)...AND MOS NUMBERS LOOK REASONABLE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGH PRESSURE BUILDS IN FOR FRIDAY...KEEPING THE AREA DRY. SOME
MODEL DIFFERENCE AS NAM AND GFS HAVE AN UPPER LEVELS TROUGH AND
ASSOCIATED SURFACE LOW MOVE EAST FROM THE MID-WEST...WITH
PRECIPITATION BEGINNING FRIDAY NIGHT. THE LOW IS FORECAST TO PASS
WELL TO OUR SOUTH BY 12Z ON SATURDAY...WITH A PERIOD OF MODERATE TO
HEAVY RAIN LATE FRIDAY NIGHT. GEM IS ABOUT 12 HOURS SLOWER...PUSHING
THE LOW OFFSHORE BY SUNDAY 00Z. THE ONSET OF PRECIPITATION FOR THE
GEM/NAM/GFS ARE SIMILAR HOWEVER. THE GEM KEEPS PRECIPITATION IN
THROUGH SATURDAY NIGHT. THE ECMWF IS AN OUTLIER...NOT PUSHING THE
LOW OFFSHORE UNTIL SATURDAY NIGHT...WITH THE AREA NOT DRYING OUT
UNTIL LATE SUNDAY NIGHT...THEREFORE...LEANED WITH THE NAM/GFS
SOLUTION
GFS HAS A WARM FRONT THAT LIFTS NORTH OF THE AREA ON SUNDAY...WHILE
THE ECMWF DOES NOT HAVE THIS OCCURRING UNTIL MONDAY. THEY THEN COME
INTO AGREEMENT WITH COLD FRONTAL PASSAGE MONDAY NIGHT AS A SURFACE
LOW TRACKS FROM THE GREAT LAKES REGION INTO SOUTHERN CANADA. THE GEM
IS THE OUTLIER IN THIS TIME PERIOD AS IT HAS A SURFACE LOW IN
SOUTHERN CANADA DIVING SOUTHEASTWARD...MOVING OVER OUR AREA...AND
OFFSHORE BYE MONDAY MORNING. GFS AND ECMWF ARE IN AGREEMENT WITH
ANOTHER COLD FRONT MOVING THROUGH TUESDAY.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
HIGH PRES SOUTH OF THE AREA CONTINUES TO DEPART AS A FRONTAL
SYSTEM MOVES ACROSS THE REGION LATER TODAY.
GENERALLY A VFR FORECAST WITH CIGS LOWERING TO AROUND 5K
FT...THOUGH BRIEF PERIODS OF MVFR POSSIBLE IN -SHRA THIS
AFTERNOON.
TIMING FOR FIRST ROUND OF ELEVATED CONVECTION WITH -SHRA IN TEMPO
GROUPS IS BASED ON LATEST RADAR TRENDS...WHICH AGREES FAIRLY WELL
WITH HRRR GUIDANCE. EXCEPT AT KSWF...WHICH SHOULD HAVE A -TSRA
PASS JUST TO THE NORTH WITHIN THE NEXT HOUR...HAVE REFRAINED FROM
INCLUDING TS/CB IN TAFS AS CONFIDENCE IN THUNDER AT ANY GIVEN
LOCATION IS LOW...BUT WILL MONITOR AND AMEND AS NEEDED. A SECOND
ROUND OF CONVECTION IS POSSIBLE LATE THIS AFTERNOON/EARLY THIS
EVENING WITH BEST TIMING OF -SHRA REFLECTED IN TEMPO GROUP IN
TAFS.
SSW WINDS 10-15KT WITH GUSTS TO AROUND 20KT TO GET STARTED BECOME
MORE SW AND GUSTS INCREASE TO 20-25KT THIS AFTERNOON.
FRONTAL SYSTEM DEPARTS THIS EVENING...AND WINDS SHIFT TO A
W...THEN NW FLOW...AND DECREASE TO AROUND 10 KT. WINDS THEN
INCREASE TO 10-15 KT WITH 20-25 KT GUSTS TOWARDS DAYBREAK
THURSDAY.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR CHANGES IN WIND
SPEED/DIRECTION...AND TIMING OF -SHRA AND ANY TS THIS AFTERNOON.
KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR CHANGES IN WIND
SPEED/DIRECTION...AND TIMING OF -SHRA AND ANY TS THIS AFTERNOON.
KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR CHANGES IN WIND
SPEED/DIRECTION...AND TIMING OF -SHRA AND ANY TS THIS AFTERNOON.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR CHANGES IN WIND
SPEED/DIRECTION...AND TIMING OF -SHRA AND ANY TS THIS AFTERNOON.
KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR CHANGES IN WIND
SPEED/DIRECTION...AND TIMING OF -SHRA AND ANY TS THIS AFTERNOON.
KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR CHANGES IN WIND
SPEED/DIRECTION...AND TIMING OF -SHRA AND ANY TS THIS AFTERNOON.
OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY...
.THURSDAY...VFR. GUSTY NW FLOW...DIMINISHING LATE.
.FRIDAY-SUNDAY...VFR.
&&
.MARINE...
A TIGHTENING PRESSURE GRADIENT IS EXPECTED TODAY AS HIGH PRESSURE
SETTLES WELL TO THE SOUTH AND LOW PRESSURE APPROACHES FROM THE
NORTH. GUSTY SOUTHWEST WINDS ARE ANTICIPATED...AND OCEAN SEAS WILL
BUILD TO SCA LEVELS. OTHER WATERS SHOULD FALL JUST SHORT OF SCA
CRITERIA WINDS...BUT THIS WILL NEED TO BE WATCHED. SEAS/WAVES WILL
BECOME CHOPPY AS A RESULT.
BY TONIGHT...THE LOW PRESSURE PASSES JUST NORTHEAST...ALLOWING WINDS
TO TEMPORARILY LIGHTEN. HOWEVER...SW WINDS SHIFT TO THE NW AND
WILL BECOME GUSTY ONCE AGAIN. SCA WINDS ARE ANTICIPATED LATE
TONIGHT AND THROUGH THURSDAY AS THIS LOW PULLS AWAY. EXPECT SCA
CONDITIONS ACROSS ALL WATERS THURSDAY.
WAVES BEGIN TO BUILD LATE FRIDAY NIGHT...COMING UP ABOVE 5 FT ON
SATURDAY AS LOW PRESSURE APPROACHES AND MOVES THROUGH THE WATERS.
WINDS WILL ALSO BE ON THE INCREASE AS THE PRESSURE GRADIENT
INCREASES. WINDS WILL GUST ABOVE 25 KT...BUT WILL DIMINISH SATURDAY
NIGHT. WAVES INCREASE ABOVE 5 FT AGAIN MONDAY NIGHT ON A STRONG
SOUTHWESTERLY FLOW...AND REMAIN ELEVATED THROUGH TUESDAY NIGHT.
&&
.FIRE WEATHER...
DEPENDING ON FINE FUEL MOISTURE AFTER POSSIBLE WETTING RAINS
TODAY...THURSDAY COULD BE ANOTHER DAY OF CONCERN IN THE NYC METRO
AREA...WITH RH LOWERING TO NEAR 30 PERCENT AND WINDS GUSTING TO 25
MPH AFTER A COLD FRONTAL PASSAGE. CONFIDENCE NOT HIGH ENOUGH TO
WARRANT A FIRE WEATHER WATCH AT THIS TIME FOR THURSDAY.
&&
.HYDROLOGY...
NO SIGNIFICANT QPF IS EXPECTED MID WEEK. ABOUT HALF AN INCH OF
RAINFALL IS EXPECTED FRIDAY NIGHT INTO SATURDAY. NO FLOODING IS
EXPECTED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT THURSDAY FOR ANZ330-
335-338-340-345.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ350-353-
355.
&&
$$
SYNOPSIS...JP/PW
NEAR TERM...BC/PW
SHORT TERM...PW
LONG TERM...JP
AVIATION...MALOIT/MPS
MARINE...JP/PW
FIRE WEATHER...
HYDROLOGY...JP/PW
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1033 PM EDT THU MAR 29 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE EAST ACROSS CENTRAL INDIANA WHICH
WILL RESULT IN NUMEROUS THUNDERSTORMS FROM TONIGHT THROUGH FRIDAY
EVENING. SOME OF THESE COULD BE SEVERE WITH DAMAGING WINDS AND HAIL
FRIDAY AFTERNOON AND EVENING. SATURDAY IS EXPECTED TO BE DRY...AND
THEN THUNDERSTORM CHANCES WILL RETURN SATURDAY NIGHT AS A WARM FRONT
LIFTS NORTHEAST ACROSS CENTRAL INDIANA ON SUNDAY FOLLOWED BY A COLD
FRONT ON TUESDAY.
&&
.NEAR TERM /REST OF TONIGHT/...
AREA OF SHOWERS ASSOCIATED WITH WEAK ENERGY ALOFT WILL CONTINUE TO
PUSH ACROSS THE FORECAST AREA THE NEXT FEW HOURS. THUS WILL KEEP LOW
POPS FOR SHOWERS THROUGH THEN. OVERNIGHT...ISENTROPIC LIFT WILL
CONTINUE AHEAD OF A WARM FRONT. HOWEVER LIFT IS NOT IMPRESSIVE...AND
LATEST HRRR MODEL SHOWS VERY LITTLE CONVECTION OVERNIGHT.
THINK THAT THE HRRR MAY BE A BIT UNDERDONE...BUT STILL THE TREND IS
FOR LOWER COVERAGE THAN PREVIOUSLY THOUGHT. THUS HAVE LOWERED POPS
OUT OF THE LIKELY CATEGORY NORTHWEST AND NUDGED DOWN ELSEWHERE.
LOW TEMPERATURES STILL LOOK OK...SO ONLY ADJUSTED HOURLY TRENDS.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
BASED ON LATEST TRENDS AND LATEST MODEL DATA...FEEL THAT POPS DURING
FRIDAY MORNING WILL BE LOWER THAN WAS PREVIOUSLY FORECAST. THUS
LOWERED POPS TO CHANCE CATEGORY FOR MUCH OF THE MORNING. LIKELY
STILL LOOKS GOOD WITH THE COLD FRONT IN THE AFTERNOON.
PREVIOUS DISCUSSION FROM THURSDAY AFTERNOON FOLLOWS...
MAIN CHALLENGE TO THE FORECAST WILL BE POSSIBILITY OF SEVERE WEATHER
ACROSS THE FORECAST AREA FRIDAY AFTERNOON AND EVENING WITH SPC DAY2
SLIGHT RISK FOR DAMAGING WINDS AND LARGE HAIL ACROSS ALL OF CENTRAL
INDIANA. MODELS IN FAIR AGREEMENT ON MOVING SURFACE LOW PRESSURE
CENTER JUST NORTH OF OUT NORTHERN COUNTIES ON FRIDAY AFTERNOON WITH
A COLD FRONT SLIDING SOUTHEAST TO NEAR THE OHIO RIVER FRIDAY
EVENING. IN ADDITION...A DECENT UPPER SHORT WAVE WILL MOVE ACROSS
DURING THE AFTERNOON IN THE FAST WESTERLY UPPER FLOW. IN
ADDITION...MODEL MIXED LAYER CAPES WILL REACH 1000-1500 J/KG WITH
THE HIGHER AMOUNTS ACROSS OUR SOUTH. WILL GO WITH LIKELY AFTERNOON
POPS WITH PLENTY OF LIFT AND INSTABILITY AND CHANCES POPS LINGERING
INTO THE EVENING. DECENT 35 KNOT DEEP LAYER UNIDIRECTIONAL SHEAR
ALONG WITH THE INSTABILITY SUGGESTS SLIGHT RISK LOOKS OK WITH LINEAR
UPWARD VERTICAL MOTION FIELD SUGGESTING A SQUALL LINE LOOKS VERY
POSSIBLE WITH PROPAGATION NORTHWEST TO SOUTHEAST. RIDGING AND A
DRYING COLUMN SHOULD ALLOW INCREASING SUNSHINE ON SATURDAY.
FINALLY...A WARM FRONT WILL LIFT NORTHEAST INTO CENTRAL INDIANA
SATURDAY NIGHT AND SUNDAY AND SHOULD COMBINE WITH INSTABILITY FOR
ANOTHER ROUND OF THUNDERSTORMS.
WITH MODELS FAR APART IN TEMPERATURES...CONFIDENCE NOT GREAT AND
THUS WENT WITH A COMBO OF A BLEND ALONG WITH TRYING TO MATCH UP WITH
ADJACENT OFFICES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ENSEMBLES IN GENERAL AGREEMENT IN BRINGING A SYSTEM THAT IS
CURRENTLY PROGGED TO BE MOVING INTO THE WEST COAST OVER THE UPCOMING
WEEKEND ACROSS THE LOCAL AREA DURING THE EARLY TO MIDDLE PARTS OF
NEXT WEEK. THERE ARE DIFFERENCES WITH RESPECT TO TIMING...BUT IT
APPEARS THE BEST CHANCES FOR PRECIPITATION WOULD BE MONDAY NIGHT
INTO TUESDAY. SOME OF THE ENSEMBLES INDICATE RATHER LOW SEA LEVEL
PRESSURES WITH THIS SYSTEM...SO THERE IS POTENTIAL FOR A SIGNIFICANT
SURFACE SYSTEM TO ACCOMPANY THE UPPER TROUGH. WILL GO WITH CHANCE
POPS MONDAY AND TUESDAY. A FEW ENSEMBLES CUT OFF THIS TROUGH OVER
THE MIDWEST BY THE MIDDLE OF NEXT WEEK...BUT THE MAJORITY OF THE
MEMBERS KEEP THIS TROUGH FAIRLY PROGRESSIVE. WILL KEEP NEXT
WEDNESDAY AND THURSDAY DRY FOR NOW.
&&
.AVIATION /DISCUSSION FOR 300300Z TAF UPDATE/...
LIGHT RAIN ASSOCIATED WITH A WEAK UPPER LEVEL DISTURBANCE PASSING
THROUGH THE FORECAST AREA THIS EVENING. PRECIP SHOULD MOVE OUT OF
THE TERMINALS WITHIN THE NEXT 1-2 HOURS WITH ONLY ISOLATED TO
SCATTERED CONVECTION ANTICIPATED THE REST OF THE OVERNIGHT.
00Z DISCUSSION FOLLOWS.
VFR CONDITIONS EXPECTED THROUGH MUCH OF THE PERIOD. POTENTIAL FOR
BRIEF DROPS TO IFR CONDITIONS WITHIN CONVECTION ON FRIDAY
AFTERNOON.
DYING CONVECTIVE CLUSTER SPREADING INTO WESTERN INDIANA EARLY THIS
EVENING WITH MID LEVEL CLOUD SHIELD ENCOMPASSING THE TERMINALS.
LIGHT RAIN WITH NO RESTRICTIONS TO VISIBILITY WILL LIKELY IMPACT
KHUF AND KLAF THIS EVENING...AND POSSIBLY KBMG AND KIND AS WELL
DEPENDING ON HOW WELL THE AREA OF RAIN CAN HOLD TOGETHER AS IT
MOVES EAST. HAVE LEANED TOWARDS HRRR GUIDANCE IN TRACKING THE
PRECIP EAST ACROSS THE REGION OVER THE NEXT SEVERAL HOURS.
ADDITIONAL SCATTERED CONVECTION MAY DEVELOP AFTER 06Z AS THE WARM
FRONT LIFTS INTO THE REGION. WITH UNCERTAINTY WITH REGARDS TO
CONVECTIVE COVERAGE...WILL CONTINUE WITH A CB MENTION ONLY INTO
FRIDAY MORNING. WINDS WILL VEER TO SOUTHEAST LATE TONIGHT IN
RESPONSE TO THE APPROACH OF THE WARM FRONT.
AFTER DAYBREAK FRIDAY...THE WARM FRONT WILL SWEEP NORTH ACROSS THE
TERMINALS WITH WINDS VEERING TO S/SW AND BECOMING GUSTY BY MIDDAY.
LIKELY TO SEE A LULL IN ANY PRECIP COVERAGE DURING THE FIRST HALF
OF THE DAY WITH CONVECTION REDEVELOPING BY EARLY AFTERNOON AS LOW
PRESSURE AND AN ASSOCIATED COLD FRONT MOVE INTO THE FORECAST AREA.
HIGHEST CONFIDENCE IN CONVECTIVE IMPACTS TO TERMINALS AFTER 17-18Z
AND HAVE INTRODUCED VCTS AT ALL SITES. POTENTIAL FOR BRIEF DROPS
TO IFR CONDITIONS WITHIN HEAVIER OR LOCALLY SEVERE CONVECTION ALL
AFTERNOON. WINDS WILL SHIFT TO WESTERLY BEHIND THE FRONT BY EARLY
EVENING WITH MODEL SOUNDINGS STRONGLY SUGGESTIVE OF THE DEVELOPMENT
OF POST-FRONTAL MVFR STRATOCU DURING THE EVENING AS AN INVERSION
SETS UP. MAY ALSO SEE A RENEWED PERIOD OF GUSTINESS FRIDAY EVENING
AS WINDS VEER TO NORTHWESTERLY AND SURFACE PRESSURE GRADIENT
TIGHTENS IN WAKE OF THE PASSAGE OF THE LOW. WILL ADDRESS THIS IN
GREATER DETAIL FOR THE 06Z TAF FORECAST.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK/50
SHORT TERM...MK/50
LONG TERM....JAS
AVIATION...RYAN
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1010 PM EDT THU MAR 29 2012
.UPDATE...
THE NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE EAST ACROSS CENTRAL INDIANA WHICH
WILL RESULT IN NUMEROUS THUNDERSTORMS FROM TONIGHT THROUGH FRIDAY
EVENING. SOME OF THESE COULD BE SEVERE WITH DAMAGING WINDS AND HAIL
FRIDAY AFTERNOON AND EVENING. SATURDAY IS EXPECTED TO BE DRY...AND
THEN THUNDERSTORM CHANCES WILL RETURN SATURDAY NIGHT AS A WARM FRONT
LIFTS NORTHEAST ACROSS CENTRAL INDIANA ON SUNDAY FOLLOWED BY A COLD
FRONT ON TUESDAY.
&&
.NEAR TERM /REST OF TONIGHT/...
AREA OF SHOWERS ASSOCIATED WITH WEAK ENERGY ALOFT WILL CONTINUE TO
PUSH ACROSS THE FORECAST AREA THE NEXT FEW HOURS. THUS WILL KEEP LOW
POPS FOR SHOWERS THROUGH THEN. OVERNIGHT...ISENTROPIC LIFT WILL
CONTINUE AHEAD OF A WARM FRONT. HOWEVER LIFT IS NOT IMPRESSIVE...AND
LATEST HRRR MODEL SHOWS VERY LITTLE CONVECTION OVERNIGHT.
THINK THAT THE HRRR MAY BE A BIT UNDERDONE...BUT STILL THE TREND IS
FOR LOWER COVERAGE THAN PREVIOUSLY THOUGHT. THUS HAVE LOWERED POPS
OUT OF THE LIKELY CATEGORY NORTHWEST AND NUDGED DOWN ELSEWHERE.
LOW TEMPERATURES STILL LOOK OK...SO ONLY ADJUSTED HOURLY TRENDS.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
BASED ON LATEST TRENDS AND LATEST MODEL DATA...FEEL THAT POPS DURING
FRIDAY MORNING WILL BE LOWER THAN WAS PREVIOUSLY FORECAST. THUS
LOWERED POPS TO CHANCE CATEGORY FOR MUCH OF THE MORNING. LIKELY
STILL LOOKS GOOD WITH THE COLD FRONT IN THE AFTERNOON.
PREVIOUS DISCUSSION FROM THURSDAY AFTERNOON FOLLOWS...
MAIN CHALLENGE TO THE FORECAST WILL BE POSSIBILITY OF SEVERE WEATHER
ACROSS THE FORECAST AREA FRIDAY AFTERNOON AND EVENING WITH SPC DAY2
SLIGHT RISK FOR DAMAGING WINDS AND LARGE HAIL ACROSS ALL OF CENTRAL
INDIANA. MODELS IN FAIR AGREEMENT ON MOVING SURFACE LOW PRESSURE
CENTER JUST NORTH OF OUT NORTHERN COUNTIES ON FRIDAY AFTERNOON WITH
A COLD FRONT SLIDING SOUTHEAST TO NEAR THE OHIO RIVER FRIDAY
EVENING. IN ADDITION...A DECENT UPPER SHORT WAVE WILL MOVE ACROSS
DURING THE AFTERNOON IN THE FAST WESTERLY UPPER FLOW. IN
ADDITION...MODEL MIXED LAYER CAPES WILL REACH 1000-1500 J/KG WITH
THE HIGHER AMOUNTS ACROSS OUR SOUTH. WILL GO WITH LIKELY AFTERNOON
POPS WITH PLENTY OF LIFT AND INSTABILITY AND CHANCES POPS LINGERING
INTO THE EVENING. DECENT 35 KNOT DEEP LAYER UNIDIRECTIONAL SHEAR
ALONG WITH THE INSTABILITY SUGGESTS SLIGHT RISK LOOKS OK WITH LINEAR
UPWARD VERTICAL MOTION FIELD SUGGESTING A SQUALL LINE LOOKS VERY
POSSIBLE WITH PROPAGATION NORTHWEST TO SOUTHEAST. RIDGING AND A
DRYING COLUMN SHOULD ALLOW INCREASING SUNSHINE ON SATURDAY.
FINALLY...A WARM FRONT WILL LIFT NORTHEAST INTO CENTRAL INDIANA
SATURDAY NIGHT AND SUNDAY AND SHOULD COMBINE WITH INSTABILITY FOR
ANOTHER ROUND OF THUNDERSTORMS.
WITH MODELS FAR APART IN TEMPERATURES...CONFIDENCE NOT GREAT AND
THUS WENT WITH A COMBO OF A BLEND ALONG WITH TRYING TO MATCH UP WITH
ADJACENT OFFICES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ENSEMBLES IN GENERAL AGREEMENT IN BRINGING A SYSTEM THAT IS
CURRENTLY PROGGED TO BE MOVING INTO THE WEST COAST OVER THE UPCOMING
WEEKEND ACROSS THE LOCAL AREA DURING THE EARLY TO MIDDLE PARTS OF
NEXT WEEK. THERE ARE DIFFERENCES WITH RESPECT TO TIMING...BUT IT
APPEARS THE BEST CHANCES FOR PRECIPITATION WOULD BE MONDAY NIGHT
INTO TUESDAY. SOME OF THE ENSEMBLES INDICATE RATHER LOW SEA LEVEL
PRESSURES WITH THIS SYSTEM...SO THERE IS POTENTIAL FOR A SIGNIFICANT
SURFACE SYSTEM TO ACCOMPANY THE UPPER TROUGH. WILL GO WITH CHANCE
POPS MONDAY AND TUESDAY. A FEW ENSEMBLES CUT OFF THIS TROUGH OVER
THE MIDWEST BY THE MIDDLE OF NEXT WEEK...BUT THE MAJORITY OF THE
MEMBERS KEEP THIS TROUGH FAIRLY PROGRESSIVE. WILL KEEP NEXT
WEDNESDAY AND THURSDAY DRY FOR NOW.
&&
.AVIATION /DISCUSSION FOR 300000Z TAF ISSUANCE/...
VFR CONDITIONS EXPECTED THROUGH MUCH OF THE PERIOD. POTENTIAL FOR
BRIEF DROPS TO IFR CONDITIONS WITHIN CONVECTION ON FRIDAY
AFTERNOON.
DYING CONVECTIVE CLUSTER SPREADING INTO WESTERN INDIANA EARLY THIS
EVENING WITH MID LEVEL CLOUD SHIELD ENCOMPASSING THE TERMINALS.
LIGHT RAIN WITH NO RESTRICTIONS TO VISIBILITY WILL LIKELY IMPACT
KHUF AND KLAF THIS EVENING...AND POSSIBLY KBMG AND KIND AS WELL
DEPENDING ON HOW WELL THE AREA OF RAIN CAN HOLD TOGETHER AS IT
MOVES EAST. HAVE LEANED TOWARDS HRRR GUIDANCE IN TRACKING THE
PRECIP EAST ACROSS THE REGION OVER THE NEXT SEVERAL HOURS.
ADDITIONAL SCATTERED CONVECTION MAY DEVELOP AFTER 06Z AS THE WARM
FRONT LIFTS INTO THE REGION. WITH UNCERTAINTY WITH REGARDS TO
CONVECTIVE COVERAGE...WILL CONTINUE WITH A CB MENTION ONLY INTO
FRIDAY MORNING. WINDS WILL VEER TO SOUTHEAST LATE TONIGHT IN
RESPONSE TO THE APPROACH OF THE WARM FRONT.
AFTER DAYBREAK FRIDAY...THE WARM FRONT WILL SWEEP NORTH ACROSS THE
TERMINALS WITH WINDS VEERING TO S/SW AND BECOMING GUSTY BY MIDDAY.
LIKELY TO SEE A LULL IN ANY PRECIP COVERAGE DURING THE FIRST HALF
OF THE DAY WITH CONVECTION REDEVELOPING BY EARLY AFTERNOON AS LOW
PRESSURE AND AN ASSOCIATED COLD FRONT MOVE INTO THE FORECAST AREA.
HIGHEST CONFIDENCE IN CONVECTIVE IMPACTS TO TERMINALS AFTER 17-18Z
AND HAVE INTRODUCED VCTS AT ALL SITES. POTENTIAL FOR BRIEF DROPS
TO IFR CONDITIONS WITHIN HEAVIER OR LOCALLY SEVERE CONVECTION ALL
AFTERNOON. WINDS WILL SHIFT TO WESTERLY BEHIND THE FRONT BY EARLY
EVENING WITH MODEL SOUNDINGS STRONGLY SUGGESTIVE OF THE DEVELOPMENT
OF POST-FRONTAL MVFR STRATOCU DURING THE EVENING AS AN INVERSION
SETS UP. MAY ALSO SEE A RENEWED PERIOD OF GUSTINESS FRIDAY EVENING
AS WINDS VEER TO NORTHWESTERLY AND SURFACE PRESSURE GRADIENT
TIGHTENS IN WAKE OF THE PASSAGE OF THE LOW. WILL ADDRESS THIS IN
GREATER DETAIL FOR THE 06Z TAF FORECAST.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK/50
SHORT TERM...MK/50
LONG TERM....JAS
AVIATION...RYAN
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
747 PM EDT THU MAR 29 2012
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE EAST ACROSS CENTRAL INDIANA WHICH
WILL RESULT IN NUMEROUS THUNDERSTORMS FROM TONIGHT THROUGH FRIDAY
EVENING. SOME OF THESE COULD BE SEVERE WITH DAMAGING WINDS AND HAIL
FRIDAY AFTERNOON AND EVENING. SATURDAY IS EXPECTED TO BE DRY...AND
THEN THUNDERSTORM CHANCES WILL RETURN SATURDAY NIGHT AS A WARM FRONT
LIFTS NORTHEAST ACROSS CENTRAL INDIANA ON SUNDAY FOLLOWED BY A COLD
FRONT ON TUESDAY.
&&
.NEAR TERM /TONIGHT/...
WEAKENING AREA OF CONVECTION WAS HOLDING TOGETHER AS IT WORKS INTO
THE FORECAST AREA THIS EVENING. BASED ON RADAR TRENDS AS WELL AS THE
HRRR MODEL...HAVE ADDED LOW POPS TO THE ENTIRE FORECAST AREA BEFORE
06Z. PRECIPITATION IS VERY LIGHT...AND SOME OF IT IS EVAPORATING
BEFORE IT REACHES THE GROUND. THUS HAVE ONLY WENT CHANCE POPS...WITH
HIGHEST POPS IN THE NORTHWEST WHERE BETTER RADAR RETURNS ARE. NO
THUNDER EXPECTED WITH THIS WEAKENING COMPLEX.
RELEVANT PORTION OF PREVIOUS DISCUSSION FOLLOWS...
MODELS AND TRENDS FAVOR LIKELY POPS NORTHWEST AND CHANCE POPS
ELSEWHERE OVERNIGHT AS ISENTROPIC LIFT SHIFTS EAST ACROSS CENTRAL
INDIANA ALONG WITH LOW CONDENSATION PRESSURE DEFICITS IN THE 300 AND
300K LEVELS. MODEL MOST UNSTABLE CAPES ARE FROM 300-800 J/KG
OVERNIGHT WHICH SHOULD BE PLENTY TO KEEP THUNDER GOING.
MOS TEMPERATURES WERE CLOSE AND APPEAR REASONABLE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
MAIN CHALLENGE TO THE FORECAST WILL BE POSSIBILITY OF SEVERE WEATHER
ACROSS THE FORECAST AREA FRIDAY AFTERNOON AND EVENING WITH SPC DAY2
SLIGHT RISK FOR DAMAGING WINDS AND LARGE HAIL ACROSS ALL OF CENTRAL
INDIANA. MODELS IN FAIR AGREEMENT ON MOVING SURFACE LOW PRESSURE
CENTER JUST NORTH OF OUT NORTHERN COUNTIES ON FRIDAY AFTERNOON WITH
A COLD FRONT SLIDING SOUTHEAST TO NEAR THE OHIO RIVER FRIDAY
EVENING. IN ADDITION...A DECENT UPPER SHORT WAVE WILL MOVE ACROSS
DURING THE AFTERNOON IN THE FAST WESTERLY UPPER FLOW. IN
ADDITION...MODEL MIXED LAYER CAPES WILL REACH 1000-1500 J/KG WITH
THE HIGHER AMOUNTS ACROSS OUR SOUTH. WILL GO WITH LIKELY AFTERNOON
POPS WITH PLENTY OF LIFT AND INSTABILITY AND CHANCES POPS LINGERING
INTO THE EVENING. DECENT 35 KNOT DEEP LAYER UNIDIRECTIONAL SHEAR
ALONG WITH THE INSTABILITY SUGGESTS SLIGHT RISK LOOKS OK WITH LINEAR
UPWARD VERTICAL MOTION FIELD SUGGESTING A SQUALL LINE LOOKS VERY
POSSIBLE WITH PROPAGATION NORTHWEST TO SOUTHEAST. RIDGING AND A
DRYING COLUMN SHOULD ALLOW INCREASING SUNSHINE ON SATURDAY.
FINALLY...A WARM FRONT WILL LIFT NORTHEAST INTO CENTRAL INDIANA
SATURDAY NIGHT AND SUNDAY AND SHOULD COMBINE WITH INSTABILITY FOR
ANOTHER ROUND OF THUNDERSTORMS.
WITH MODELS FAR APART IN TEMPERATURES...CONFIDENCE NOT GREAT AND
THUS WENT WITH A COMBO OF A BLEND ALONG WITH TRYING TO MATCH UP WITH
ADJACENT OFFICES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ENSEMBLES IN GENERAL AGREEMENT IN BRINGING A SYSTEM THAT IS
CURRENTLY PROGGED TO BE MOVING INTO THE WEST COAST OVER THE UPCOMING
WEEKEND ACROSS THE LOCAL AREA DURING THE EARLY TO MIDDLE PARTS OF
NEXT WEEK. THERE ARE DIFFERENCES WITH RESPECT TO TIMING...BUT IT
APPEARS THE BEST CHANCES FOR PRECIPITATION WOULD BE MONDAY NIGHT
INTO TUESDAY. SOME OF THE ENSEMBLES INDICATE RATHER LOW SEA LEVEL
PRESSURES WITH THIS SYSTEM...SO THERE IS POTENTIAL FOR A SIGNIFICANT
SURFACE SYSTEM TO ACCOMPANY THE UPPER TROUGH. WILL GO WITH CHANCE
POPS MONDAY AND TUESDAY. A FEW ENSEMBLES CUT OFF THIS TROUGH OVER
THE MIDWEST BY THE MIDDLE OF NEXT WEEK...BUT THE MAJORITY OF THE
MEMBERS KEEP THIS TROUGH FAIRLY PROGRESSIVE. WILL KEEP NEXT
WEDNESDAY AND THURSDAY DRY FOR NOW.
&&
.AVIATION /DISCUSSION FOR 300000Z TAF ISSUANCE/...
VFR CONDITIONS EXPECTED THROUGH MUCH OF THE PERIOD. POTENTIAL FOR
BRIEF DROPS TO IFR CONDITIONS WITHIN CONVECTION ON FRIDAY
AFTERNOON.
DYING CONVECTIVE CLUSTER SPREADING INTO WESTERN INDIANA EARLY THIS
EVENING WITH MID LEVEL CLOUD SHIELD ENCOMPASSING THE TERMINALS.
LIGHT RAIN WITH NO RESTRICTIONS TO VISIBILITY WILL LIKELY IMPACT
KHUF AND KLAF THIS EVENING...AND POSSIBLY KBMG AND KIND AS WELL
DEPENDING ON HOW WELL THE AREA OF RAIN CAN HOLD TOGETHER AS IT
MOVES EAST. HAVE LEANED TOWARDS HRRR GUIDANCE IN TRACKING THE
PRECIP EAST ACROSS THE REGION OVER THE NEXT SEVERAL HOURS.
ADDITIONAL SCATTERED CONVECTION MAY DEVELOP AFTER 06Z AS THE WARM
FRONT LIFTS INTO THE REGION. WITH UNCERTAINTY WITH REGARDS TO
CONVECTIVE COVERAGE...WILL CONTINUE WITH A CB MENTION ONLY INTO
FRIDAY MORNING. WINDS WILL VEER TO SOUTHEAST LATE TONIGHT IN
RESPONSE TO THE APPROACH OF THE WARM FRONT.
AFTER DAYBREAK FRIDAY...THE WARM FRONT WILL SWEEP NORTH ACROSS THE
TERMINALS WITH WINDS VEERING TO S/SW AND BECOMING GUSTY BY MIDDAY.
LIKELY TO SEE A LULL IN ANY PRECIP COVERAGE DURING THE FIRST HALF
OF THE DAY WITH CONVECTION REDEVELOPING BY EARLY AFTERNOON AS LOW
PRESSURE AND AN ASSOCIATED COLD FRONT MOVE INTO THE FORECAST AREA.
HIGHEST CONFIDENCE IN CONVECTIVE IMPACTS TO TERMINALS AFTER 17-18Z
AND HAVE INTRODUCED VCTS AT ALL SITES. POTENTIAL FOR BRIEF DROPS
TO IFR CONDITIONS WITHIN HEAVIER OR LOCALLY SEVERE CONVECTION ALL
AFTERNOON. WINDS WILL SHIFT TO WESTERLY BEHIND THE FRONT BY EARLY
EVENING WITH MODEL SOUNDINGS STRONGLY SUGGESTIVE OF THE DEVELOPMENT
OF POST-FRONTAL MVFR STRATOCU DURING THE EVENING AS AN INVERSION
SETS UP. MAY ALSO SEE A RENEWED PERIOD OF GUSTINESS FRIDAY EVENING
AS WINDS VEER TO NORTHWESTERLY AND SURFACE PRESSURE GRADIENT
TIGHTENS IN WAKE OF THE PASSAGE OF THE LOW. WILL ADDRESS THIS IN
GREATER DETAIL FOR THE 06Z TAF FORECAST.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK/50
SHORT TERM...MK
LONG TERM....JAS
AVIATION...RYAN
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
710 PM EDT THU MAR 29 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE EAST ACROSS CENTRAL INDIANA WHICH
WILL RESULT IN NUMEROUS THUNDERSTORMS FROM TONIGHT THROUGH FRIDAY
EVENING. SOME OF THESE COULD BE SEVERE WITH DAMAGING WINDS AND HAIL
FRIDAY AFTERNOON AND EVENING. SATURDAY IS EXPECTED TO BE DRY...AND
THEN THUNDERSTORM CHANCES WILL RETURN SATURDAY NIGHT AS A WARM FRONT
LIFTS NORTHEAST ACROSS CENTRAL INDIANA ON SUNDAY FOLLOWED BY A COLD
FRONT ON TUESDAY.
&&
.NEAR TERM /TONIGHT/...
MAIN CHALLENGE TO THE FORECAST TONIGHT WILL BE POPS. RADAR CURRENTLY
WAS SHOWING WARM AIR ADVECTION SHOWER AND THUNDERSTORM ACTIVITY
ACROSS WESTERN ILLINOIS AND NORTHEASTERN MISSOURI JUST NORTH OF A
WARM FRONT THAT WAS STRETCHING FROM NEAR KANSAS CITY TO WESTERN
KENTUCKY. MODELS AND TRENDS FAVOR SMALL POPS WEST THIS EVENING WITH
LIKELY POPS NORTHWEST AND CHANCE POPS ELSEWHERE OVERNIGHT AS
ISENTROPIC LIFT SHIFTS EAST ACROSS CENTRAL INDIANA ALONG WITH LOW
CONDENSATION PRESSURE DEFICITS IN THE 300 AND 300K LEVELS. MODEL
MOST UNSTABLE CAPES ARE FROM 300-800 J/KG OVERNIGHT WHICH SHOULD BE
PLENTY TO KEEP THUNDER GOING.
MOS TEMPERATURES WERE CLOSE AND APPEAR REASONABLE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
MAIN CHALLENGE TO THE FORECAST WILL BE POSSIBILITY OF SEVERE WEATHER
ACROSS THE FORECAST AREA FRIDAY AFTERNOON AND EVENING WITH SPC DAY2
SLIGHT RISK FOR DAMAGING WINDS AND LARGE HAIL ACROSS ALL OF CENTRAL
INDIANA. MODELS IN FAIR AGREEMENT ON MOVING SURFACE LOW PRESSURE
CENTER JUST NORTH OF OUT NORTHERN COUNTIES ON FRIDAY AFTERNOON WITH
A COLD FRONT SLIDING SOUTHEAST TO NEAR THE OHIO RIVER FRIDAY
EVENING. IN ADDITION...A DECENT UPPER SHORT WAVE WILL MOVE ACROSS
DURING THE AFTERNOON IN THE FAST WESTERLY UPPER FLOW. IN
ADDITION...MODEL MIXED LAYER CAPES WILL REACH 1000-1500 J/KG WITH
THE HIGHER AMOUNTS ACROSS OUR SOUTH. WILL GO WITH LIKELY AFTERNOON
POPS WITH PLENTY OF LIFT AND INSTABILITY AND CHANCES POPS LINGERING
INTO THE EVENING. DECENT 35 KNOT DEEP LAYER UNIDIRECTIONAL SHEAR
ALONG WITH THE INSTABILITY SUGGESTS SLIGHT RISK LOOKS OK WITH LINEAR
UPWARD VERTICAL MOTION FIELD SUGGESTING A SQUALL LINE LOOKS VERY
POSSIBLE WITH PROPAGATION NORTHWEST TO SOUTHEAST. RIDGING AND A
DRYING COLUMN SHOULD ALLOW INCREASING SUNSHINE ON SATURDAY.
FINALLY...A WARM FRONT WILL LIFT NORTHEAST INTO CENTRAL INDIANA
SATURDAY NIGHT AND SUNDAY AND SHOULD COMBINE WITH INSTABILITY FOR
ANOTHER ROUND OF THUNDERSTORMS.
WITH MODELS FAR APART IN TEMPERATURES...CONFIDENCE NOT GREAT AND
THUS WENT WITH A COMBO OF A BLEND ALONG WITH TRYING TO MATCH UP WITH
ADJACENT OFFICES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ENSEMBLES IN GENERAL AGREEMENT IN BRINGING A SYSTEM THAT IS
CURRENTLY PROGGED TO BE MOVING INTO THE WEST COAST OVER THE UPCOMING
WEEKEND ACROSS THE LOCAL AREA DURING THE EARLY TO MIDDLE PARTS OF
NEXT WEEK. THERE ARE DIFFERENCES WITH RESPECT TO TIMING...BUT IT
APPEARS THE BEST CHANCES FOR PRECIPITATION WOULD BE MONDAY NIGHT
INTO TUESDAY. SOME OF THE ENSEMBLES INDICATE RATHER LOW SEA LEVEL
PRESSURES WITH THIS SYSTEM...SO THERE IS POTENTIAL FOR A SIGNIFICANT
SURFACE SYSTEM TO ACCOMPANY THE UPPER TROUGH. WILL GO WITH CHANCE
POPS MONDAY AND TUESDAY. A FEW ENSEMBLES CUT OFF THIS TROUGH OVER
THE MIDWEST BY THE MIDDLE OF NEXT WEEK...BUT THE MAJORITY OF THE
MEMBERS KEEP THIS TROUGH FAIRLY PROGRESSIVE. WILL KEEP NEXT
WEDNESDAY AND THURSDAY DRY FOR NOW.
&&
.AVIATION /DISCUSSION FOR 300000Z TAF ISSUANCE/...
VFR CONDITIONS EXPECTED THROUGH MUCH OF THE PERIOD. POTENTIAL FOR
BRIEF DROPS TO IFR CONDITIONS WITHIN CONVECTION ON FRIDAY
AFTERNOON.
DYING CONVECTIVE CLUSTER SPREADING INTO WESTERN INDIANA EARLY THIS
EVENING WITH MID LEVEL CLOUD SHIELD ENCOMPASSING THE TERMINALS.
LIGHT RAIN WITH NO RESTRICTIONS TO VISIBILITY WILL LIKELY IMPACT
KHUF AND KLAF THIS EVENING...AND POSSIBLY KBMG AND KIND AS WELL
DEPENDING ON HOW WELL THE AREA OF RAIN CAN HOLD TOGETHER AS IT
MOVES EAST. HAVE LEANED TOWARDS HRRR GUIDANCE IN TRACKING THE
PRECIP EAST ACROSS THE REGION OVER THE NEXT SEVERAL HOURS.
ADDITIONAL SCATTERED CONVECTION MAY DEVELOP AFTER 06Z AS THE WARM
FRONT LIFTS INTO THE REGION. WITH UNCERTAINTY WITH REGARDS TO
CONVECTIVE COVERAGE...WILL CONTINUE WITH A CB MENTION ONLY INTO
FRIDAY MORNING. WINDS WILL VEER TO SOUTHEAST LATE TONIGHT IN
RESPONSE TO THE APPROACH OF THE WARM FRONT.
AFTER DAYBREAK FRIDAY...THE WARM FRONT WILL SWEEP NORTH ACROSS THE
TERMINALS WITH WINDS VEERING TO S/SW AND BECOMING GUSTY BY MIDDAY.
LIKELY TO SEE A LULL IN ANY PRECIP COVERAGE DURING THE FIRST HALF
OF THE DAY WITH CONVECTION REDEVELOPING BY EARLY AFTERNOON AS LOW
PRESSURE AND AN ASSOCIATED COLD FRONT MOVE INTO THE FORECAST AREA.
HIGHEST CONFIDENCE IN CONVECTIVE IMPACTS TO TERMINALS AFTER 17-18Z
AND HAVE INTRODUCED VCTS AT ALL SITES. POTENTIAL FOR BRIEF DROPS
TO IFR CONDITIONS WITHIN HEAVIER OR LOCALLY SEVERE CONVECTION ALL
AFTERNOON. WINDS WILL SHIFT TO WESTERLY BEHIND THE FRONT BY EARLY
EVENING WITH MODEL SOUNDINGS STRONGLY SUGGESTIVE OF THE DEVELOPMENT
OF POST-FRONTAL MVFR STRATOCU DURING THE EVENING AS AN INVERSION
SETS UP. MAY ALSO SEE A RENEWED PERIOD OF GUSTINESS FRIDAY EVENING
AS WINDS VEER TO NORTHWESTERLY AND SURFACE PRESSURE GRADIENT
TIGHTENS IN WAKE OF THE PASSAGE OF THE LOW. WILL ADDRESS THIS IN
GREATER DETAIL FOR THE 06Z TAF FORECAST.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK
SHORT TERM...MK
LONG TERM....JAS
AVIATION...RYAN
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1255 PM EDT WED MAR 28 2012
.UPDATE...
AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A COLD FRONT SLOWLY SAGGING SOUTH THROUGH SOUTHERN CENTRAL INDIANA
WILL KEEP LOW CHANCES FOR THUNDER AROUND THE SOUTHERN COUNTIES UNTIL
MID AFTERNOON. MEANWHILE HIGH PRESSURE WILL BUILD IN FROM THE NORTH
AND OVERSPREAD THE AREA BRINGING CLEARING SKIES. THE RIDGING WILL
RESULT IN DRY WEATHER THROUGH FRIDAY WHEN THE NEXT DISTURBANCE
ENTERS THE FORECAST AREA. BEYOND THAT...QUIET CONDITIONS FOR THE
REMAINDER OF THE WEEKEND...AND THEN ANOTHER SYSTEM OVER THE GREAT
LAKES REGION IS PROGGED FOR MONDAY. ITS ASSOCIATED COLD FRONT WILL
TRIGGER THUNDERSTORM ACTIVITY ACROSS CENTRAL INDIANA.
&&
.NEAR TERM /REST OF TODAY/...
COLD FRONT HAS SLOWED IN ITS MOVEMENT THROUGH THE AREA AND CONTINUES
TO SLOWLY SAG SOUTH. REMOVED POPS FROM AREAS NORTH OF THE
FRONT...BUT EVEN THOUGH RPECIP HAS FOR THE MOST PART LEFT THE AREA
RAPID UPDATE MODELS SUCH AS HRRR AND VSREFS SHOW REDEVELOPMENT OVER
THE NEXT FEW HOURS ALONG/AHEAD OF THE FRONT SO WILL KEEP A LOW
CHANCE POPS GOING ACROSS THE SOUTH INTO THE MID AFTERNOON. OTHERWISE
HIGH PRESSURE CONTINUES TO BUILD IN FROM THE NORTH AND WILL CLEAR
SKIES OUT FROM NORTH TO SOUTH THROUGH THE DAY.
TEMPS...MODELS DO NOT SEEM TO BE ACCOUNTING FOR CLEARING VERY
WELL...THUS SEEM A TAD LOW ON TODAY/S HIGHS. AS A RESULT...TRENDED A
FEW DEGREES ABOVE GUIDANCE DUE TO SUFFICIENT SUNSHINE LATER TODAY.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
THE MAIN FOCUS OF THE SHORT TERM IS THE NEXT ROUND OF SHOWERS AND
THUNDERSTORMS ON FRIDAY.
RIDGE WILL RE-ESTABLISH ITSELF ACROSS FORECAST AREA TONIGHT
BRINGING DRY CONDITIONS THROUGH FRIDAY. HOWEVER...THE RIDGE WILL
BREAK DOWN ON THURSDAY NIGHT AS A 500 MB SHORTWAVE APPROACHES
CENTRAL INDIANA. THE GFS AND EURO ARE A TAD MORE PROGRESSIVE THAN
THE NAM IN REGARD TO PRECIP ON THURSDAY NIGHT...BUT INCREASING
ISENTROPIC LIFT SUPPORTS POPS AS EARLY AS FRI 06Z. THE BEST LIFT
WILL OCCUR IN THE FRI 12-18Z TIME FRAME AS SHORT WAVE AND SURFACE
LOW PASS OVER CENTRAL INDIANA. SO...INTRODUCED DEFINITE POPS INTO
GRIDS DURING THAT PERIOD...WHICH MAY HAVE TO BE EXTENDED INTO
FRIDAY NIGHT DEPENDING ON POSITION OF ASSOCIATED COLD FRONT.
TEMPS...STUCK WITH A BLEND UNTIL FRIDAY. THAT/S WHEN MODELS
STARTED HAVING A LITTLE TROUBLE WITH THE AFOREMENTIONED
DISTURBANCE. TRENDED ON THE COOLER SIDE FOR DAYTIME HIGHS...AND
LEANED ON THE WARMER SIDE FOR FRIDAY NIGHT LOWS DUE TO INCREASED
CLOUD COVER.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY NIGHT/...
THIS PERIOD BEGINS WITH SOME REMAINING LOW CHANCES FOR POPS AS FRONT
IS PROGGED TO BE DROPPING SOUTH OF THE AREA BY SATURDAY AFTERNOON.
MODELS HAVE BEEN INCREASINGLY PROGRESSIVE WITH THIS FRONT SO HAVE
BACKED OFF ON POPS SLIGHTLY FOR SATURDAY. UPPER RIDGING BUILDS IN
EARNEST BY SATURDAY NIGHT...AND PROVIDES QUIET DRY AND WARMER
WEATHER FOR CENTRAL INDIANA THROUGH SUNDAY NIGHT. ANOTHER FRONT IS
PROGGED TO APPROACH THE REGION SUNDAY NIGHT AND CROSS THE AREA
MONDAY INTO MONDAY EVENING...BRINGING CHANCES FOR THUNDER BACK INTO
THE FORECAST. RIDGE BUILDS BACK IN BY TUESDAY.
&&
.AVIATION /DISCUSSION FOR 281800Z TAF ISSUANCE/...
VFR THROUGH THE PERIOD AND EXCEPT FOR POSSIBLY KBMG...TAFS SHOULD BE
MOSTLY CLEAR TOO. A WEAK COLD FRONT OVER SOUTHERN INDIANA MAY
PRODUCE AN ISOLATED CB SOUTH OF KBMG EARLY THIS AFTERNOON. BUT I
DON`T THINK IT WILL AFFECT ANY OF OUR TAF`S.
THIS COLD FRONT WILL MOVE ON TO THE SOUTHEAST AS HIGH PRESSURE OVER
THE NORTHERN PLAINS BUILDS EAST INTO THE GREAT LAKES LATER TONIGHT
AND THURSDAY.
MAIN ISSUE WILL BE WINDS THIS AFTERNOON AS SUSTAINED NORTHWEST WINDS
UP TO 15 KNOTS AND GUSTS UP TO 25 KNOTS POSSIBLE. PRESSURE GRADIENT
WILL DECREASE THIS AFTERNOON AND WINDS WILL BECOME LIGHT BY TONIGHT.
ON THURSDAY WINDS WILL BECOME NORTHEAST 7 TO 10 KNOTS.
SOME MID/HIGH CLOUDS MAY SPREAD SPREAD INTO SOUTHERN AND WEST
SECTIONS BY MIDDAY THURSDAY AS A WARM FRONT STARTS TO APPROACH FROM
THE SOUTHWEST.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD/CP
NEAR TERM...TDUD/CP
SHORT TERM...TDUD
LONG TERM....SMF
AVIATION...JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1048 AM EDT WED MAR 28 2012
.UPDATE...
AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A COLD FRONT SLOWLY SAGGING SOUTH THROUGH SOUTHERN CENTRAL INDIANA
WILL KEEP LOW CHANCES FOR THUNDER AROUND THE SOUTHERN COUNTIES UNTIL
MID AFTERNOON. MEANWHILE HIGH PRESSURE WILL BUILD IN FROM THE NORTH
AND OVERSPREAD THE AREA BRINGING CLEARING SKIES. THE RIDGING WILL
RESULT IN DRY WEATHER THROUGH FRIDAY WHEN THE NEXT DISTURBANCE
ENTERS THE FORECAST AREA. BEYOND THAT...QUIET CONDITIONS FOR THE
REMAINDER OF THE WEEKEND...AND THEN ANOTHER SYSTEM OVER THE GREAT
LAKES REGION IS PROGGED FOR MONDAY. ITS ASSOCIATED COLD FRONT WILL
TRIGGER THUNDERSTORM ACTIVITY ACROSS CENTRAL INDIANA.
&&
.NEAR TERM /REST OF TODAY/...
COLD FRONT HAS SLOWED IN ITS MOVEMENT THROUGH THE AREA AND CONTINUES
TO SLOWLY SAG SOUTH. REMOVED POPS FROM AREAS NORTH OF THE
FRONT...BUT EVEN THOUGH RPECIP HAS FOR THE MOST PART LEFT THE AREA
RAPID UPDATE MODELS SUCH AS HRRR AND VSREFS SHOW REDEVELOPMENT OVER
THE NEXT FEW HOURS ALONG/AHEAD OF THE FRONT SO WILL KEEP A LOW
CHANCE POPS GOING ACROSS THE SOUTH INTO THE MID AFTERNOON. OTHERWISE
HIGH PRESSURE CONTINUES TO BUILD IN FROM THE NORTH AND WILL CLEAR
SKIES OUT FROM NORTH TO SOUTH THROUGH THE DAY.
TEMPS...MODELS DO NOT SEEM TO BE ACCOUNTING FOR CLEARING VERY
WELL...THUS SEEM A TAD LOW ON TODAY/S HIGHS. AS A RESULT...TRENDED A
FEW DEGREES ABOVE GUIDANCE DUE TO SUFFICIENT SUNSHINE LATER TODAY.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
THE MAIN FOCUS OF THE SHORT TERM IS THE NEXT ROUND OF SHOWERS AND
THUNDERSTORMS ON FRIDAY.
RIDGE WILL RE-ESTABLISH ITSELF ACROSS FORECAST AREA TONIGHT
BRINGING DRY CONDITIONS THROUGH FRIDAY. HOWEVER...THE RIDGE WILL
BREAK DOWN ON THURSDAY NIGHT AS A 500 MB SHORTWAVE APPROACHES
CENTRAL INDIANA. THE GFS AND EURO ARE A TAD MORE PROGRESSIVE THAN
THE NAM IN REGARD TO PRECIP ON THURSDAY NIGHT...BUT INCREASING
ISENTROPIC LIFT SUPPORTS POPS AS EARLY AS FRI 06Z. THE BEST LIFT
WILL OCCUR IN THE FRI 12-18Z TIME FRAME AS SHORT WAVE AND SURFACE
LOW PASS OVER CENTRAL INDIANA. SO...INTRODUCED DEFINITE POPS INTO
GRIDS DURING THAT PERIOD...WHICH MAY HAVE TO BE EXTENDED INTO
FRIDAY NIGHT DEPENDING ON POSITION OF ASSOCIATED COLD FRONT.
TEMPS...STUCK WITH A BLEND UNTIL FRIDAY. THAT/S WHEN MODELS
STARTED HAVING A LITTLE TROUBLE WITH THE AFOREMENTIONED
DISTURBANCE. TRENDED ON THE COOLER SIDE FOR DAYTIME HIGHS...AND
LEANED ON THE WARMER SIDE FOR FRIDAY NIGHT LOWS DUE TO INCREASED
CLOUD COVER.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY NIGHT/...
THIS PERIOD BEGINS WITH SOME REMAINING LOW CHANCES FOR POPS AS FRONT
IS PROGGED TO BE DROPPING SOUTH OF THE AREA BY SATURDAY AFTERNOON.
MODELS HAVE BEEN INCREASINGLY PROGRESSIVE WITH THIS FRONT SO HAVE
BACKED OFF ON POPS SLIGHTLY FOR SATURDAY. UPPER RIDGING BUILDS IN
EARNEST BY SATURDAY NIGHT...AND PROVIDES QUIET DRY AND WARMER
WEATHER FOR CENTRAL INDIANA THROUGH SUNDAY NIGHT. ANOTHER FRONT IS
PROGGED TO APPROACH THE REGION SUNDAY NIGHT AND CROSS THE AREA
MONDAY INTO MONDAY EVENING...BRINGING CHANCES FOR THUNDER BACK INTO
THE FORECAST. RIDGE BUILDS BACK IN BY TUESDAY.
&&
.AVIATION /DISCUSSION FOR 281500Z KIND TAF UPDATE/...
MINOR CHANGES MAKED TO KIND TAF PER OBSERVATIONS. OTHERWISE...NO
OTHER CHANGES NEEDED AT THIS TIME. PREVIOUS AVIATION DISCUSSION
FOLLOWS...
VFR CONDITIONS EXPECTED THROUGHOUT THE FORECAST PERIOD.
AS OF 7 AM THIS MORNING...FRONTAL BOUNDARY JUST ABOUT READY TO
DROP SOUTH OF ALL THE FORECAST TERMINALS. WILL START OFF THE
PERIOD WITHOUT ANY MENTION OF SHOWERS (EXCEPT FOR POSSIBLY KEEPING
SOME IN FOR KBMG FOR THE FIRST HALF HOUR TO HR) JUST SOME SCATTERED
CU IN THE WAKE OF THE FRONT.
CLOUDS SHOULD QUICKLY CLEAR BY MIDDAY AS DRIER AIR ADVECTS INTO
THE REGION BEHIND THE FRONT. PRESENCE OF STRONGER WINDS ALOFT
THROUGH THE DAY AND MIXING LEVELS UP TO AROUND 5KFT WILL PROMOTE
W/NW WIND GUSTS AT 25-30KTS FOR MUCH OF THE AFTERNOON. WINDS WILL
VEER TO NORTHERLY AND LIGHTEN DURING THE EVENING AS A RIDGE OF
HIGH PRESSURE EXPANDS INTO THE REGION FROM THE NORTHWEST.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD/CP
NEAR TERM...TDUD/CP
SHORT TERM...TDUD
LONG TERM....SMF
AVIATION...SMF/JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1044 AM EDT WED MAR 28 2012
.UPDATE...
THE SYNOPSIS AND NEAR TERM SECTION HAVE BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A COLD FRONT SLOWLY SAGGING SOUTH THROUGH SOUTHERN CENTRAL INDIANA
WILL KEEP LOW CHANCES FOR THUNDER AROUND THE SOUTHERN COUNTIES UNTIL
MID AFTERNOON. MEANWHILE HIGH PRESSURE WILL BUILD IN FROM THE NORTH
AND OVERSPREAD THE AREA BRINGING CLEARING SKIES. THE RIDGING WILL
RESULT IN DRY WEATHER THROUGH FRIDAY WHEN THE NEXT DISTURBANCE
ENTERS THE FORECAST AREA. BEYOND THAT...QUIET CONDITIONS FOR THE
REMAINDER OF THE WEEKEND...AND THEN ANOTHER SYSTEM OVER THE GREAT
LAKES REGION IS PROGGED FOR MONDAY. ITS ASSOCIATED COLD FRONT WILL
TRIGGER THUNDERSTORM ACTIVITY ACROSS CENTRAL INDIANA.
&&
.NEAR TERM /REST OF TODAY/...
COLD FRONT HAS SLOWED IN ITS MOVEMENT THROUGH THE AREA AND CONTINUES
TO SLOWLY SAG SOUTH. REMOVED POPS FROM AREAS NORTH OF THE
FRONT...BUT EVEN THOUGH RPECIP HAS FOR THE MOST PART LEFT THE AREA
RAPID UPDATE MODELS SUCH AS HRRR AND VSREFS SHOW REDEVELOPMENT OVER
THE NEXT FEW HOURS ALONG/AHEAD OF THE FRONT SO WILL KEEP A LOW
CHANCE POPS GOING ACROSS THE SOUTH INTO THE MID AFTERNOON. OTHERWISE
HIGH PRESSURE CONTINUES TO BUILD IN FROM THE NORTH AND WILL CLEAR
SKIES OUT FROM NORTH TO SOUTH THROUGH THE DAY.
TEMPS...MODELS DO NOT SEEM TO BE ACCOUNTING FOR CLEARING VERY
WELL...THUS SEEM A TAD LOW ON TODAY/S HIGHS. AS A RESULT...TRENDED A
FEW DEGREES ABOVE GUIDANCE DUE TO SUFFICIENT SUNSHINE LATER TODAY.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
THE MAIN FOCUS OF THE SHORT TERM IS THE NEXT ROUND OF SHOWERS AND
THUNDERSTORMS ON FRIDAY.
RIDGE WILL RE-ESTABLISH ITSELF ACROSS FORECAST AREA TONIGHT
BRINGING DRY CONDITIONS THROUGH FRIDAY. HOWEVER...THE RIDGE WILL
BREAK DOWN ON THURSDAY NIGHT AS A 500 MB SHORTWAVE APPROACHES
CENTRAL INDIANA. THE GFS AND EURO ARE A TAD MORE PROGRESSIVE THAN
THE NAM IN REGARD TO PRECIP ON THURSDAY NIGHT...BUT INCREASING
ISENTROPIC LIFT SUPPORTS POPS AS EARLY AS FRI 06Z. THE BEST LIFT
WILL OCCUR IN THE FRI 12-18Z TIME FRAME AS SHORT WAVE AND SURFACE
LOW PASS OVER CENTRAL INDIANA. SO...INTRODUCED DEFINITE POPS INTO
GRIDS DURING THAT PERIOD...WHICH MAY HAVE TO BE EXTENDED INTO
FRIDAY NIGHT DEPENDING ON POSITION OF ASSOCIATED COLD FRONT.
TEMPS...STUCK WITH A BLEND UNTIL FRIDAY. THAT/S WHEN MODELS
STARTED HAVING A LITTLE TROUBLE WITH THE AFOREMENTIONED
DISTURBANCE. TRENDED ON THE COOLER SIDE FOR DAYTIME HIGHS...AND
LEANED ON THE WARMER SIDE FOR FRIDAY NIGHT LOWS DUE TO INCREASED
CLOUD COVER.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY NIGHT/...
THIS PERIOD BEGINS WITH SOME REMAINING LOW CHANCES FOR POPS AS FRONT
IS PROGGED TO BE DROPPING SOUTH OF THE AREA BY SATURDAY AFTERNOON.
MODELS HAVE BEEN INCREASINGLY PROGRESSIVE WITH THIS FRONT SO HAVE
BACKED OFF ON POPS SLIGHTLY FOR SATURDAY. UPPER RIDGING BUILDS IN
EARNEST BY SATURDAY NIGHT...AND PROVIDES QUIET DRY AND WARMER
WEATHER FOR CENTRAL INDIANA THROUGH SUNDAY NIGHT. ANOTHER FRONT IS
PROGGED TO APPROACH THE REGION SUNDAY NIGHT AND CROSS THE AREA
MONDAY INTO MONDAY EVENING...BRINGING CHANCES FOR THUNDER BACK INTO
THE FORECAST. RIDGE BUILDS BACK IN BY TUESDAY.
&&
.AVIATION /DISCUSSION FOR 281200Z TAF ISSUANCE/...
VFR CONDITIONS EXPECTED THROUGHOUT THE FORECAST PERIOD.
AS OF 7 AM THIS MORNING...FRONTAL BOUNDARY JUST ABOUT READY TO
DROP SOUTH OF ALL THE FORECAST TERMINALS. WILL START OFF THE
PERIOD WITHOUT ANY MENTION OF SHOWERS (EXCEPT FOR POSSIBLY KEEPING
SOME IN FOR KBMG FOR THE FIRST HALF HOUR TO HR) JUST SOME SCATTERED
CU IN THE WAKE OF THE FRONT.
CLOUDS SHOULD QUICKLY CLEAR BY MIDDAY AS DRIER AIR ADVECTS INTO
THE REGION BEHIND THE FRONT. PRESENCE OF STRONGER WINDS ALOFT
THROUGH THE DAY AND MIXING LEVELS UP TO AROUND 5KFT WILL PROMOTE
W/NW WIND GUSTS AT 25-30KTS FOR MUCH OF THE AFTERNOON. WINDS WILL
VEER TO NORTHERLY AND LIGHTEN DURING THE EVENING AS A RIDGE OF
HIGH PRESSURE EXPANDS INTO THE REGION FROM THE NORTHWEST.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD/CP
NEAR TERM...TDUD/CP
SHORT TERM...TDUD
LONG TERM....SMF
AVIATION...SMF
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1139 PM CDT TUE MAR 27 2012
.UPDATE 28/06Z AVIATION DISCUSSION...
.SHORT TERM /TONIGHT/...
REMOVED ADV FROM AFD...REST OF FORECAST LOOKS ON TRACK. /REV
.PREVIOUS SHORT TERM /TONIGHT/...
SFC TROUGH AXIS ASSOCIATED WITH NORTHERN MINNESOTA LOW PRESSURE IS
EXTENDING SOUTH THROUGH CNTRL IA THIS AFTERNOON. AIRMASS BEHIND THE
TROUGH HAS DOWNSLOPE PROPERTIES INITIALLY REMAINING MILD YET MUCH
DRIER WITH DEWPOINTS IN THE 30S ADVECTING IN. DEWPOINTS REMAIN IN
THE MID TO UPPER 50S OVER THE SOUTHEAST IN ADVANCE OF THE SYSTEM.
UPPER PV ANOMALY OVER SRN SOUTH DAKOTA WILL TRACK EAST AND WILL BE
OVER FAR SOUTH CENTRAL MINNESOTA BY 00Z. SOME ASSOCIATED KINEMATIC
FORCING WILL OCCUR TO THE SOUTHEAST OF THE SYSTEM. CURRENTLY
INSTABILITY HAS BEEN INCREASING OVER THE SOUTHEAST THIRD OF THE
WARNING AREA. RUC AND NAM PROXIMITY SOUNDINGS SHOW A WEAK CAP
LOCATED NEAR 750 MB WHICH DOES NOT ERODE UNTIL AFTER 23Z WITH THE
ARRIVAL OF MID LEVEL COOLING AND KINEMATICS WITH THE MID LEVEL WAVE.
POSSIBLE A STORM OR TWO MAY FIRE OVER THE FAR SOUTHEAST BUT OVERALL
THE CURRENT INSTABILITY IS NOT EXPECTED TO BE REALIZED UNTIL IT
PUSHES SOUTHEAST OF THE STATE.
A FEW SITES NEAR WIND ADVISORY CRITERIA ATTM MOMENT THOUGH OVERALL
MOST ARE BELOW. HAVE TRIMMED PORTIONS OF THE ADVISORY BUT HAVE KEPT
THE NORTH TO KEEP COLLABORATED WITH SURROUNDING SITES. HAVE MOVED
END TIME UP TO 7 PM WITH WINDS DIMINISHING WITH THE LOSS OF DAY TIME
HEATING AND MIXING.
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
TWO PRIMARY SYSTEMS TO CONTEND WITH IN THIS PERIOD. WEAK RIDGE
APPROACHING THE MO VALLEY PRECEDING SHORT WAVE EJECTING OUT OF
CURRENT EAST PACIFIC LONG WAVE THROUGH. THIS WAVE SHOULD REACH THE
HIGH PLAINS LATE TOMORROW WHICH...COMBINED WITH THE DEPARTING
RIDGE...WILL INCREASE WARM ADVECTION INTO THE MO VALLEY. THETA-E
ADVECTION ADVANCES INTO SWRN IA COINCIDENT WITH ELEVATED CAPE
GRADIENT. ALTHOUGH BEST ISENTROPIC LIFT WILL REMAIN NW INTO THE
DAKOTAS AND ERN MN...MODEL 300K SURFACES NEAR INVERSION TOP SUGGEST
THERE WILL BE SUFFICIENT LIFT AND SATURATION EARLY THU MORNING FOR
CONVECTION TO DEVELOP AND LINGER INTO THE MORNING.
ATTENTION THEN TURNS UPSTREAM WHERE BOTH NAM AND GFS DEPICT
1500-2500 J/KG MLCAPES BECOMING UNCAPPED JUST WEST OF MO RIVER
DURING PEAK HEATING. LOW LEVEL CONVERGENCE IS SOMEWHAT WEAK...BUT
THIS FAVORABLE THERMODYNAMIC ENVIRONMENT AIDED BY LARGE SCALE
FORCING WITH WAVE SHOULD BE SUFFICIENT FOR A MCS TO DEVELOP AND THEN
LIKELY WEAKEN INTO THE EVENING WITH LOSS OF HEATING. REGARDING
SEVERE POTENTIAL DURING EVENT...ELEVATED NATURE AND FAIRLY WEAK
UNIDIRECTIONAL FLOW IN EFFECTIVE INFLOW LAYER EARLY THU SHOULD
DIMINISH THIS SEVERE POTENTIAL. MOST LIKELY SEVERE CHANCES LOOK TO
BE DURING PEAK HEATING TAPPING BETTER 0-6KM SHEAR LATE AFTERNOON AND
EVENING WHEN AND IF CONVECTION BECOMES SURFACE BASED.
WEAK NORTHERN STREAM WAVE HAS RESULTED IN SLIGHT CHANCES FRI NIGHT
WITH NEXT LARGE SYSTEM IN THE OFFING EARLY NEXT WEEK. MODELS HAVE
COME INTO SOMEWHAT BETTER AGREEMENT WITH RESPECT TO TIMING
SUGGESTING FORCING INCREASING SUN NIGHT FOLLOWED BY FRONTAL PASSAGE
LATE SUNDAY AFTERNOON OR SUNDAY NIGHT. BEST SHEAR SEEMS TO REMAIN
TO OUR SOUTH AND INSTABILITY IS UNREMARKABLE AT THIS POINT SO DO NOT
SEE ELEVATED SEVERE THREAT WITH THIS SYSTEM AT THE MOMENT. DIRTY NW
FLOW WILL KEPT LOW CHANCES GOING IN ITS WAKE THROUGH TUE. TEMPS
WILL DROP SHARPLY BEHIND THIS...BUT ONLY DOWN TO ABOUT CLIMO. NO
FREEZING TEMPS OR FROST ANTICIPATED THROUGH DAY 7.
&&
.AVIATION...28/06Z
VFR TO UNLIMITED CIGS EXPECTED FOR THE NIGHT WITH SCT150 WITH SOME
MID LEVEL CLOUDS TAKING AIM AT SOUTHERN REGIONS OVERNIGHT. OTHERWISE
WINDS HAVE RELAXED...BUT WILL INCREASE AS EXPECTED AT 15Z WITH
MIXING ONCE AGAIN THROUGH 23Z. AFT 23Z...CIGS WILL LOWER ACROSS THE
WEST BUT REMAIN VFR. NORTHWEST WINDS WILL GIVE WAY TO LIGHT EAST
WINDS PRIOR TO INCREASING RAPIDLY 6 TO 12 HOURS AFT END OF TAF
PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE
&&
$$
SHORT TERM...DONAVON/REV
AVIATION...REV
LONG TERM...SMALL
AREA FORECAST DISCUSSION
NWS TOPEKA KS
324 PM CDT WED MAR 28 2012
.DISCUSSION...
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
&&
.AVIATION...
SATELLITE OBS SHOW A BAND OF VFR CLOUDS DRIFTING EASTWARD AROUND
THE SURFACE LOW OVER NORTHWEST OKLAHOMA. A SURFACE WARM FRONT WILL
SLOWLY LIFT NORTHWARD WITH DEVELOPING STRONG TO SEVERE TSRA OVER
THE AREA AFTER 23Z AT KMHK AND 01Z AT KTOP/KFOE. KEPT VCTS AT THIS
TIME AS EXACT TIMING OR COVERAGE OF THESE STORMS IS UNCERTAIN. WIND
SPEEDS BELOW 10 KTS WILL VARY ALONG THE FRONTAL BOUNDARY FROM
NORTHEAST AT KMHK TO EAST SOUTHEAST AT KTOP/KFOE THROUGH 20Z
BEFORE BECOMING PREDOMINANTLY SOUTHEAST JUST ABOVE 10 KTS. MVFR
CIGS ARE POSSIBLE AS THE PRECIPITATION CLEARS TAF SITES AFTER 05Z
AT KMHK AND 07Z AT KTOP/KFOE.
BOWEN
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
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.
&&
.AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
AN AREA OF STRATUS/MVFR CIGS MIGRATED INTO CENTRAL KANSAS AT
MIDDAY AND WILL GRADUALLY LIFT/DISSIPATE INTO MID-AFTERNOON.
ISOLATED TO WIDELY SCATTERED CONVECTION IS EXPECTED TO DEVELOP
BY EARLY THIS EVENING ALONG A WARM FRONT...FROM CENTRAL KANSAS
INTO THE FLINT HILLS. THIS ACTIVITY SHOULD THEN MOVE OR DEVELOP
EAST AND SOUTHEAST INTO FAR EASTERN KANSAS TONIGHT. SURFACE LOW
PRESSURE WILL CONTINUE TO HANG OUT ACROSS CENTRAL KANSAS INTO
THURSDAY MORNING...WITH A PERIOD OF LOW CIGS/MVFR EXPECTED ACROSS
CENTRAL KANSAS.
KED
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 61 85 56 79 / 30 30 20 10
HUTCHINSON 60 83 54 78 / 30 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 / 20 20 20 10
SALINA 59 83 54 80 / 30 20 20 10
MCPHERSON 61 82 54 79 / 30 20 20 10
COFFEYVILLE 63 85 59 81 / 30 20 60 20
CHANUTE 61 84 59 81 / 50 20 60 10
IOLA 61 83 59 81 / 50 20 60 10
PARSONS-KPPF 62 85 59 80 / 30 20 60 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
111 AM MDT WED MAR 28 2012
.UPDATE...
ISSUED AT 848 PM MDT TUE MAR 27 2012
JUST COMPLETED AN UPDATE. ADJUSTED CLOUD COVER BEST ON LATEST
SATELLITE MODEL DATA. MODELS HAVE BACKED OFF ON THE CLOUD COVER
THE REST OF THE NIGHT AND DECREASED. LATEST HRRR BRINGS SOME FOG
CLOSE TO THE SOUTHERN PORTION OF THE FORECAST AREA. INSERTED
PATCHY FOG IN THIS AREA FROM 09Z TO 14Z. ADJUSTED THE
DEWPOINTS/WINDS PER LATEST RUC/HRRR. 00Z SOUNDINGS AND NAM WOULD
INDICATE THAT EVEN THOUGH THERE IS ELEVATED INSTABILITY...THE
SOUNDINGS ARE VERY VERY DRY AND CAPPED ALOFT. SO LEFT ANY MENTION
OF THUNDERSTORMS THE REST OF THE NIGHT.
UPDATE ISSUED AT 536 PM MDT TUE MAR 27 2012
CANCELLED RED FLAG WARNING EARLY AS WINDS HAVE DROPPED OFF
DRAMATICALLY. CURRENTLY RATHER THICK HIGH LEVEL CLOUD COVER IS
DRAPED ACROSS THE AREA. THIS IS BEING CAUSE BY RIGHT REAR QUADRANT
OF MID/UPPER JET THAT REMAINS/MOVES ACROSS THE AREA THROUGH MOST
OF THE NIGHT. SO INCREASED CLOUD COVER...ESPECIALLY FOR THIS
EVENING. WIND FIELD IS RATHER LIGHT RIGHT NOW WITH RUC/HRRR
CATCHING THE WIND FIELD NICELY SO ADJUSTED USING THEM.
SOMETHING TO WATCH FOR LATER TONIGHT. THERE WILL BE A RIGHT REAR
QUADRANT OF THE JET NEAR THE EASTERN PORTION OF THE FORECAST AREA
WITH AN APPROACHING SHORTWAVE TROUGH. MODELS SHOWING A RATHER HIGH
AMOUNT OF ELEVATED INSTABILITY. HOWEVER...THE CINH LOOKS STRONG
BUT WITH SOME POCKETS OF WEAKNESS. QUESTION WILL THERE BE ENOUGH
MOISTURE IN THE COLUMN TO GET THIS FULLY REALIZED. WILL CONTINUE
TO WATCH THROUGH THE EVENING AND LOOK AT LATEST MODEL DATA/00Z
SOUNDINGS TO SEE IF NEED TO ADD SOME THUNDERSTORMS FOR LATER TONIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 200 PM MDT TUE MAR 27 2012
WEAK UPPER LEVEL RIDGING WILL OCCUR ACROSS THE CENTRAL PLAINS
TONIGHT AND WEDNESDAY BEFORE SEVERAL WEAK SHORT WAVE TROUGHS FLATTEN
IT OUT WEDNESDAY NIGHT AND THURSDAY. TEMPERATURES WILL CONTINUE
UNSEASONABLY MILD FOR LATE MARCH UNDER THIS REGIME.
THE WEAK COLD FRONT WHICH PASSED THROUGH THE AREA LAST NIGHT IS
APPROACHING THE WICHITA AREA WHERE IT WILL BEGIN TO STALL. SURFACE
DEWPOINTS IN THE MIDDLE 50S ARE BEING PUSHED INTO SOUTHEAST KANSAS
IN THE SHORT TERM AS A RESULT OF THE FRONTAL PASSAGE...BUT AS A LEE
TROUGH AND RETURN SURFACE FLOW SET UP DURING THE DAY WEDNESDAY...LOW
LEVEL MOISTURE WILL RAPIDLY RETURN TO NORTHWEST KANSAS.
FORECAST SOUNDINGS HINT AT A STRATUS/STRATOCU DECK BY MIDDAY
TOMORROW MOVING ACROSS OUR EASTERN COUNTIES. CANNOT RULE OUT SOME
LIGHT SHOWERS AT THAT TIME GIVEN 700 MB WARM ADVECTION PATTERN. HAVE
INCLUDED LOW POPS AND SHOWERS MAINLY FOR WEDNESDAY AFTERNOON IN THIS
AREA. KEPT THUNDER OUT FOR THE TIME BEING GIVEN THE ANTICIPATED
CLOUD COVER AND LACK OF GOOD INSTABILITY.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 101 AM MDT WED MAR 28 2012
UPPER RIDGE AXIS WILL BE OVER THE REGION ON SATURDAY WITH WARM AND
DRY CONDITIONS. HOWEVER IT WILL QUICKLY BREAK DOWN WITH APPROACH
OF SHORTWAVE TROUGH ON SUNDAY. IT IS FORECAST TO EJECT ACROSS THE
NORTHERN ROCKIES AND ADJACENT PLAINS...TOO FAR NORTH TO BRING
PRECIPITATION CHANCES. HOWEVER WITH A JET MAX FORECAST TO ROTATE
THROUGH THE BASE OF THE TROUGH OVER THE CENTRAL HIGH PLAINS IT
COULD EASILY TURN INTO OUR NEXT HIGH WIND AND FIRE WEATHER EVENT.
COOLER TEMPERATURES WILL FOLLOW IN ITS WAKE FOR MONDAY AND
TUESDAY...BUT AS RIDGE REBUILDS TEMPERATURES WILL BEGIN WARMING
AGAIN FOR THE MIDDLE OF THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1051 PM MDT TUE MAR 27 2012
INTERESTING SET OF TAFS. LOT OF LOW LEVEL MOISTURE NOT TOO FAR TO
OUR SOUTH AND WILL EVENTUALLY GET DRAWN UP INTO THE AREA. MODELS
HAVE CHANGED THEIR TUNE A LITTLE AND NOW APPEAR MORE AGGRESSIVE IN
BRINGING UP LOWER CEILINGS. CONSIDERING THE WEAK LOW LEVEL FLOW
WHICH EVENTUALLY TRANSITIONS TO AN EASTERLY DIRECTION...DO NOT
THINK THE MODELS ARE UNREASONABLE IN THEIR DEPICTION. AS A RESULT
BY LATER TONIGHT THROUGH THE DAY TOMORROW...THE CEILINGS LOWER
NEAR TO MVFR OR INTO THE MVFR CATEGORY. THERE APPEARS TO BE SOME
CLEARING LATER IN THE DAY BUT THAT WILL BE SHORT LIVED AS MORE
ABUNDANT LOW LEVEL MOISTURE GETS DRAWN UP INTO THE AREA NEAR THE
END OR JUST AFTER THE END OF THIS PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
KS...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...DLF
LONG TERM....024
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1056 PM MDT TUE MAR 27 2012
.UPDATE...
ISSUED AT 848 PM MDT TUE MAR 27 2012
JUST COMPLETED AN UPDATE. ADJUSTED CLOUD COVER BEST ON LATEST
SATELLITE MODEL DATA. MODELS HAVE BACKED OFF ON THE CLOUD COVER
THE REST OF THE NIGHT AND DECREASED. LATEST HRRR BRINGS SOME FOG
CLOSE TO THE SOUTHERN PORTION OF THE FORECAST AREA. INSERTED
PATCHY FOG IN THIS AREA FROM 09Z TO 14Z. ADJUSTED THE
DEWPOINTS/WINDS PER LATEST RUC/HRRR. 00Z SOUNDINGS AND NAM WOULD
INDICATE THAT EVEN THOUGH THERE IS ELEVATED INSTABILITY...THE
SOUNDINGS ARE VERY VERY DRY AND CAPPED ALOFT. SO LEFT ANY MENTION
OF THUNDERSTORMS THE REST OF THE NIGHT.
UPDATE ISSUED AT 536 PM MDT TUE MAR 27 2012
CANCELLED RED FLAG WARNING EARLY AS WINDS HAVE DROPPED OFF
DRAMATICALLY. CURRENTLY RATHER THICK HIGH LEVEL CLOUD COVER IS
DRAPED ACROSS THE AREA. THIS IS BEING CAUSE BY RIGHT REAR QUADRANT
OF MID/UPPER JET THAT REMAINS/MOVES ACROSS THE AREA THROUGH MOST
OF THE NIGHT. SO INCREASED CLOUD COVER...ESPECIALLY FOR THIS
EVENING. WIND FIELD IS RATHER LIGHT RIGHT NOW WITH RUC/HRRR
CATCHING THE WIND FIELD NICELY SO ADJUSTED USING THEM.
SOMETHING TO WATCH FOR LATER TONIGHT. THERE WILL BE A RIGHT REAR
QUADRANT OF THE JET NEAR THE EASTERN PORTION OF THE FORECAST AREA
WITH AN APPROACHING SHORTWAVE TROUGH. MODELS SHOWING A RATHER HIGH
AMOUNT OF ELEVATED INSTABILITY. HOWEVER...THE CINH LOOKS STRONG
BUT WITH SOME POCKETS OF WEAKNESS. QUESTION WILL THERE BE ENOUGH
MOISTURE IN THE COLUMN TO GET THIS FULLY REALIZED. WILL CONTINUE
TO WATCH THROUGH THE EVENING AND LOOK AT LATEST MODEL DATA/00Z
SOUNDINGS TO SEE IF NEED TO ADD SOME THUNDERSTORMS FOR LATER TONIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 200 PM MDT TUE MAR 27 2012
WEAK UPPER LEVEL RIDGING WILL OCCUR ACROSS THE CENTRAL PLAINS
TONIGHT AND WEDNESDAY BEFORE SEVERAL WEAK SHORT WAVE TROUGHS FLATTEN
IT OUT WEDNESDAY NIGHT AND THURSDAY. TEMPERATURES WILL CONTINUE
UNSEASONABLY MILD FOR LATE MARCH UNDER THIS REGIME.
THE WEAK COLD FRONT WHICH PASSED THROUGH THE AREA LAST NIGHT IS
APPROACHING THE WICHITA AREA WHERE IT WILL BEGIN TO STALL. SURFACE
DEWPOINTS IN THE MIDDLE 50S ARE BEING PUSHED INTO SOUTHEAST KANSAS
IN THE SHORT TERM AS A RESULT OF THE FRONTAL PASSAGE...BUT AS A LEE
TROUGH AND RETURN SURFACE FLOW SET UP DURING THE DAY WEDNESDAY...LOW
LEVEL MOISTURE WILL RAPIDLY RETURN TO NORTHWEST KANSAS.
FORECAST SOUNDINGS HINT AT A STRATUS/STRATOCU DECK BY MIDDAY
TOMORROW MOVING ACROSS OUR EASTERN COUNTIES. CANNOT RULE OUT SOME
LIGHT SHOWERS AT THAT TIME GIVEN 700 MB WARM ADVECTION PATTERN. HAVE
INCLUDED LOW POPS AND SHOWERS MAINLY FOR WEDNESDAY AFTERNOON IN THIS
AREA. KEPT THUNDER OUT FOR THE TIME BEING GIVEN THE ANTICIPATED
CLOUD COVER AND LACK OF GOOD INSTABILITY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 200 PM MDT TUE MAR 27 2012
WEDNESDAY NIGHT-THURSDAY...LOW CLOUDS AND FOG EXPECTED WEDNESDAY
NIGHT SLOWLY DECREASING IN COVERAGE THURSDAY MORNING. MAY HAVE A
BRIEF PERIOD NORTH WINDS GUSTING 30 MPH ALONG AND WEST OF THE
CO/KS BORDER DURING THE AFTERNOON AS A FRONT MOVES THROUGH. HIGH
TEMPERATURES IN THE 70S.
FRIDAY...DRY WITH HIGHS IN THE MID 70S TO AROUND 80.
SATURDAY-MONDAY...ATTENTION TURNS TO DEVELOPING UPPER TROUGH
WHICH BY 00Z SUNDAY SHOULD BE COMING ASHORE ALONG THE WEST COAST
AND MOVING THROUGH THE FORECAST AREA BY 00Z MONDAY. BY 00Z TUESDAY
THE SYSTEM IS EXPECTED TO LIFT NORTHEAST. SOUTHERLY WINDS WILL
SLOWLY INCREASE THROUGH THE DAY SATURDAY AND MAY BECOME BREEZY
ALONG AND WEST OF THE CO/KS BORDER. ON SUNDAY A COLD FRONT MOVES
IN ASSOCIATED WITH THE UPPER TROUGH. WINDS WILL SHIFT TO THE
NORTHWEST AND INCREASE IN SPEED WITH WINDY CONDITIONS EXPECTED.
THESE GUSTY NORTHWEST WINDS WILL CONTINUE SUNDAY NIGHT AND MONDAY
WITH GUSTS TO 45 MPH POSSIBLE. A WIND ADVISORY MAY BE NEEDED.
HIGH TEMPERATURES SATURDAY IN THE 80S FALLING INTO THE LOW 70S
WEST OF THE CO/KS BORDER SUNDAY...MID TO UPPER 70S EAST. ON MONDAY
EXPECTED MID 50S TO LOW 60S WHICH IS RIGHT NEAR NORMAL FOR LATE
MARCH.
PRECIPITATION CHANCES WILL BE CONFINED TO SUNDAY AFTERNOON AND
SUNDAY NIGHT WHERE SOME RAIN SHOWERS ARE POSSIBLE.
TUESDAY...BROAD UPPER RIDGE REDEVELOPS AS SUNDAYS SYSTEM LIFTS
TOWARD THE GREAT LAKES AND ANOTHER STORM MOVES TOWARD THE PACIFIC
NORTHWEST. AFTERNOON HIGHS GENERALLY IN THE 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1051 PM MDT TUE MAR 27 2012
INTERESTING SET OF TAFS. LOT OF LOW LEVEL MOISTURE NOT TOO FAR TO
OUR SOUTH AND WILL EVENTUALLY GET DRAWN UP INTO THE AREA. MODELS
HAVE CHANGED THEIR TUNE A LITTLE AND NOW APPEAR MORE AGGRESSIVE IN
BRINGING UP LOWER CEILINGS. CONSIDERING THE WEAK LOW LEVEL FLOW
WHICH EVENTUALLY TRANSITIONS TO AN EASTERLY DIRECTION...DO NOT
THINK THE MODELS ARE UNREASONABLE IN THEIR DEPICTION. AS A RESULT
BY LATER TONIGHT THROUGH THE DAY TOMORROW...THE CEILINGS LOWER
NEAR TO MVFR OR INTO THE MVFR CATEGORY. THERE APPEARS TO BE SOME
CLEARING LATER IN THE DAY BUT THAT WILL BE SHORT LIVED AS MORE
ABUNDANT LOW LEVEL MOISTURE GETS DRAWN UP INTO THE AREA NEAR THE
END OR JUST AFTER THE END OF THIS PERIOD.
&&
.FIRE WEATHER...
ISSUED AT 200 PM MDT TUE MAR 27 2012
THURSDAY AFTERNOON...THE COMBINATION OF RELATIVE HUMIDITY BELOW
20 PERCENT AND NORTH WINDS GUSTING TO 30 MPH MAY CREATE CRITICAL
FIRE WEATHER CONDITIONS GENERALLY WEST OF A LINE FROM BENKELMAN
NEBRASKA TO GOODLAND.
SUNDAY AFTERNOON...RELATIVE HUMIDITY WILL BE BELOW 20 PERCENT.
WEST TO SOUTHWEST WINDS OF 15 TO 20 MPH WITH HIGHER GUSTS MID TO LATE
AFTERNOON WILL SHIFT TO THE NORTHWEST AND GUST AROUND 30 MPH LATE
IN THE DAY TO CREATE CRITICAL FIRE WEATHER CONDITIONS...GENERALLY
WEST OF A LINE FROM TRENTON NEBRASKA TO GOODLAND AND TRIBUNE
KANSAS.
MONDAY AFTERNOON AND TUESDAY AFTERNOON...CRITICAL FIRE WEATHER
CONDITIONS EXPECTED ACROSS THE ENTIRE FORECAST AREA AS NORTHWEST
WINDS GUSTING IN THE 35 TO 45 MPH RANGE COMBINE WITH AFTERNOON
HUMIDITY BELOW 20 PERCENT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
KS...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...DLF
LONG TERM....007
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
417 PM EDT WED MAR 28 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL CROSS THE REGION THIS EVENING. HIGH PRESSURE
BUILDS OVER THE AREA THURSDAY AND FRIDAY. A LOW PRESSURE SYSTEM AND
ASSOCIATED COLD FRONT WILL AFFECT THE REGION LATE FRIDAY NIGHT
THROUGH SATURDAY. HIGH PRESSURE RETURNS SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
A WEAK COLD FRONT CONTINUES TO TRACK SOUTHWARD THIS AFTERNOON AND WILL
PASS THROUGH OUR FA MAINLY BETWEEN 00Z AND 06Z THIS EVENING. AN
INCREASED PRESSURE GRADIENT AHEAD OF THE FRONT IS RESULTING IN
WARM BUT WINDY CONDITIONS THIS AFTERNOON. GUSTS BETWEEN 30-35 MPH
WILL BE COMMON UNTIL SUNSET. CURRENT REGIONAL RADAR MOSAIC SHOWS A
BROKEN LINE OF SHOWERS AND TSTMS ALONG THE FRONT. LATEST HRRR AND
RUC FORECAST GUIDANCE HAS THE LINE MOSTLY DISSIPATING BEFORE
REACHING OUR NORTHERN AREAS AROUND SUNSET. WILL MAINTAIN SLIGHT CHC
POPS THROUGH THIS EVENING TO ACCOUNT FOR THE POSSIBILITY THAT THIS
ACTIVITY HOLDS TOGETHER BUT NOT OVERLY CONFIDENT THAT IT WILL BE
MUCH OF AN ISSUE GIVEN DRY LOW-LEVEL DOWNSLOPE FLOW AND LACK OF
INSTABILITY. ONCE THE FRONT DROPS SOUTH OF THE FA OVERNIGHT WILL
SEE WIND SHIFT TO THE NW. LOWS WILL BE MILDER THAN LAST NIGHT...IN
THE 50S TO LOW 60S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
HIGH PRESSURE OVER THE NORTHERN GREAT LAKES WILL BEGIN BUILDING SE
ON THURSDAY. SHOULD BE ENOUGH OF A PRESSURE GRADIENT BETWEEN LOW
PRESSURE OFF THE NEW ENGLAND COAST AND THE HIGH OVER THE GREAT
LAKES TO ALLOW FOR BREEZY NW WINDS (ESPECIALLY EASTERN AREAS
THROUGH MID AFTN). DRY AIRMASS BUILDING IN WITH THE SFC HIGH WILL
ALLOW FOR PLENTY OF SUNSHINE. LOW-LEVEL THICKNESS VALUES/H85 TEMPS
SUPPORT HIGHS FROM THE MID-60S ON THE LOWER MD EASTERN SHORE TO
THE LOW/MID 70S IN THE SW ZONES. TURNING CHILLY AGAIN THURSDAY
NIGHT WITH THE SFC HIGH BUILDING OVERHEAD AND DRY AIR IN PLACE. LOWS
IN THE UPR 30S TO LOW 40S. FOR FRIDAY...THE SFC HIGH MOVES
OFFSHORE AND ALLOWS FOR A S-SE FLOW. ANY PRECIP IS EXPECTED TO
REMAIN TO OUR SOUTH ALONG A WEAK WARM FRONT. AN ONSHORE COMPONENT
TO THE WIND WILL CAUSE THE COOLEST TEMPS TO BE NEAR THE COAST.
HIGHS WILL RANGE FROM NR 60 ON THE LWR MD EASTERN SHORE TO THE LOW
70S IN OUR SW ZONES. AN AREA OF LOW PRESSURE WILL TRACK ACROSS THE
REGION LATE FRIDAY NIGHT THROUGH SATURDAY MORNING BEFORE MOVING
OFFSHORE SATURDAY AFTERNOON. BEST CHANCE FOR PRECIP WILL BE ACROSS
OUR NORTHERN ZONES FRIDAY NIGHT...CLOSEST TO THE APPROACHING LOW.
WILL THEN CARRY LOW END CHC POPS ALL AREAS ON SATURDAY AS THE SFC
LOW TRAVERSES THE REGION. LOWS FRIDAY NIGHT IN THE UPR 40S TO MID
50S. HIGHS SATURDAY FROM THE 60S ON THE EASTERN SHORE TO THE
MID/UPR 70S IN OUR SW ZONES.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A COLD FRONT IS EXPECTED TO DROP THROUGH THE MID ATLANTIC SATURDAY
NIGHT FOLLOWED BY HIGH PRESSURE BUILDING IN FROM THE NORTH LATE
SATURDAY NIGHT INTO SUNDAY. THERE IS SOME DISAGREEMENT AMONGST MODEL
GUIDANCE WITH RESPECT TO HOW QUICKLY THE HIGH MOVES OFF THE COAST
SUNDAY AFTERNOON. GIVEN THAT THE HIGH APPEARS RATHER WEAK WILL GO
WITH THE IDEA OF IT MOVING OFF THE COAST BY AFTERNOON WITH HIGH
TEMPERATURES REACHING THE UPPER 60S IN THE EASTERN SHORE TO MID 70S
IN THE PIEDMONT. LOW-LEVEL WARM AIR SURGES INTO THE REGION BY MONDAY
ALONG WITH DOWNSLOPE FLOW AND THIS WILL RESULT IN MUCH WARMER HIGH
TEMPERATURES. MAXIMA WERE RAISED INTO THE UPPER 70S TO LOW 80S WEST
OF THE BAY...BUT LATEST LOW-LEVEL THICKNESSES WOULD SUPPORT LOW TO
MID 80S INLAND. TUESDAY SHOULD REMAIN MILD AHEAD OF A COLD FRONT
APPROACHING FROM THE WEST. MOISTURE WITH THIS FRONT IS UNCERTAIN AT
THIS TIME...SO SLIGHT CHANCE POPS WILL BE MAINTAINED. MORE SEASONAL
TEMPERATURES SHOULD ARRIVE BEHIND THE FRONT FOR MIDWEEK.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
A STRONG SURFACE PRESSURE GRADIENT AHEAD OF A COLD FRONT
APPROACHING FROM THE NORTH WILL CONTINUE TO DRIVE A 15-20KT SW
WIND WITH 25-30KT GUSTS THROUGH LATE AFTERNOON/EARLY EVENING. A
BROKEN LINE OF THUNDERSTORMS NEAR THE MASON-DIXON LINE AS OF
17-18Z IS EXPECTED TO DECREASE IN COVERAGE AND INTENSITY AS IT
APPROACHES THE LOCAL THE LOCAL TAF SITES VERY LATE THIS AFTERNOON.
SBY WOULD APPEAR TO HAVE THE BEST CHANCE (ALBEIT LOW) OF A TS AROUND
22-00Z...WITH A FEW SHOWERS PROGRESSING DOWN THE COAST LATER THIS
EVENING. CONFIDENCE OF SHRA OR TS AFFECTING A TERMINAL IS LOW...SO
NO WEATHER HAS BEEN INCLUDED WITH THE 18Z TAF ISSUANCE. THE COLD
FRONT CLEARS THE REGION LATER TONIGHT WITH A GUSTY NW WIND
DEVELOPING THURSDAY MORNING (ESPECIALLY NEAR THE COAST). THERE IS
A POTENTIAL FOR ANOTHER ROUND OF 15-20KT SUSTAINED WIND WITH
25-30KT GUSTS.
&&
.MARINE...
A COLD FRONT CROSSES THE MID ATLANTIC COAST TONIGHT FOLLOWED BY HIGH
PRESSURE BUILDING IN FROM THE NORTH THURSDAY. THE SW WIND OF TODAY
WILL DECLINE THIS EVENING...BEFORE SHIFTING TO THE NW AND INCREASING
ONCE AGAIN LATE. A MODESTLY STRONG NW WIND SHOULD CONTINUE DURING
THE DAY THURSDAY...BEFORE DIMINISHING THURSDAY NIGHT AS HIGH
PRESSURE SETTLES OVERHEAD. CURRENT SCA HEADLINES WILL BE MAINTAINED
AS IS...ALTHOUGH LATEST GUIDANCE SUGGEST SCA CONDITIONS COULD END
BEFORE THURSDAY NIGHT. HIGH PRESSURE SHIFTS OFFSHORE FRIDAY AS LOW
PRESSURE APPROACHES FROM THE WEST. THIS AREA OF LOW PRESSURE CROSSES
THE MARINE AREA FRIDAY NIGHT AND SATURDAY...WITH HIGH PRESSURE
RETURNING SATURDAY NIGHT INTO SUNDAY. HIGH PRESSURE SETTLES OFF THE
SOUTHEAST COAST EARLY NEXT WEEK.
&&
.FIRE WEATHER...
DRY AND BREEZY CONDITIONS ON THURSDAY MAY ENHANCE FIRE DANGER
ESPECIALLY IF THERE IS NOT ANY RAIN WITH THE WEAK COLD FRONTAL
PASSAGE TONIGHT. NW WINDS WILL AVERAGE 12-20 MPH THURSDAY WITH
GUSTS UP TO 25 MPH. THE STRONGEST WINDS ARE EXPECTED DURING THE
MORNING AND EARLY AFTERNOON. ALSO...RH VALUES ARE EXPECTED TO
TUMBLE THURSDAY AFTERNOON...LIKELY FALLING INTO THE 22-32 PERCENT
RANGE. AFTER COORDINATING WITH THE FIRE AGENCIES IN MD AND
VA...WILL NOT BE ISSUING ANY HEADLINES ATTM BECAUSE CONFIDENCE IS
NOT HIGH ENOUGH THAT WE SEE WIDESPREAD 20 MPH SUSTAINED
WINDS...ESPECIALLY DURING PEAK HEATING IN THE AFTERNOON. WILL SEE
HOW MUCH RAIN FALLS TONIGHT AND THEN WILL LIKELY ISSUE AN ENHANCED
FIRE DANGER STATEMENT FOR A PORTION OF OUR MD AND VA COUNTIES
EARLY THURSDAY MORNING.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT THURSDAY NIGHT FOR
ANZ630>634-656-658.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT FRIDAY FOR ANZ650-652-654.
&&
$$
SYNOPSIS...JDM
NEAR TERM...JDM
SHORT TERM...JDM
LONG TERM...AJZ
AVIATION...AJZ
MARINE...AJZ
FIRE WEATHER...JDM
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
347 PM EDT WED MAR 28 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL CROSS THE REGION THIS EVENING. HIGH PRESSURE
BUILDS OVER THE AREA THURSDAY AND FRIDAY. A LOW PRESSURE SYSTEM AND
ASSOCIATED COLD FRONT WILL AFFECT THE REGION LATE FRIDAY NIGHT
THROUGH SATURDAY. HIGH PRESSURE RETURNS SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
A WEAK COLD FRONT CONTINUES TO TRACK SOUTHWARD THIS AFTERNOON AND WILL
PASS THROUGH OUR FA MAINLY BETWEEN 00Z AND 06Z THIS EVENING. AN
INCREASED PRESSURE GRADIENT AHEAD OF THE FRONT IS RESULTING IN
WARM BUT WINDY CONDITIONS THIS AFTERNOON. GUSTS BETWEEN 30-35 MPH
WILL BE COMMON UNTIL SUNSET. CURRENT REGIONAL RADAR MOSAIC SHOWS A
BROKEN LINE OF SHOWERS AND TSTMS ALONG THE FRONT. LATEST HRRR AND
RUC FORECAST GUIDANCE HAS THE LINE MOSTLY DISSIPATING BEFORE
REACHING OUR NORTHERN AREAS AROUND SUNSET. WILL MAINTAIN SLIGT CHC
POPS THROUGH THIS EVENING TO ACCOUNT FOR THE POSSIBILITY THAT THIS
ACTIVITY HOLDS TOGETHER BUT NOT OVERLY CONFIDENT THAT IT WILL BE
MUCH OF AN ISSUE GIVEN DRY LOW-LEVEL DOWNSLOPE FLOW AND LACK OF
INSTABILITY. ONCE THE FRONT DROPS SOUTH OF THE FA OVERNIGHT WILL
SEE WIND SHIFT TO THE NW. LOWS WILL BE MILDER THAN LAST NIGHT...IN
THE 50S TO LOW 60S.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
HIGH PRESSURE OVER THE NORTHERN GREAT LAKES WILL BEGIN BUILDING SE
ON THURSDAY. SHOULD BE ENOUGH OF A PRESSURE GRADIENT BETWEEN LOW
PRESSURE OFF THE NEW ENGLAND COAST AND THE HIGH OVER THE GREAT
LAKES TO ALLOW FOR BREEZY NW WINDS (ESPECIALLY EASTERN AREAS
THROUGH MID AFTN). DRY AIRMASS BUILDING IN WITH THE SFC HIGH WILL
ALLOW FOR PLENTY OF SUNSHINE. LOW-LEVEL THICKNESS VALUES/H85 TEMPS
SUPPORT HIGHS FROM THE MID-60S ON THE LOWER MD EASTERN SHORE TO
THE LOW/MID 70S IN THE SW ZONES. TURNING CHILLY AGAIN THURSDAY
NIGHT WITH THE SFC HIGH BUILDING OVERHEAD AND DRY AIR IN PLACE. LOWS
IN THE UPR 30S TO LOW 40S. FOR FRIDAY...THE SFC HIGH MOVES
OFFSHORE AND ALLOWS FOR A S-SE FLOW. ANY PRECIP IS EXPECTED TO
REMAIN TO OUR SOUTH ALONG A WEAK WARM FRONT. AN ONSHORE COMPONENT
TO THE WIND WILL CAUSE THE COOLEST TEMPS TO BE NEAR THE COAST.
HIGHS WILL RANGE FROM NR 60 ON THE LWR MD EASTERN SHORE TO THE LOW
70S IN OUR SW ZONES. AN AREA OF LOW PRESSURE WILL TRACK ACROSS THE
REGION LATE FRIDAY NIGHT THROUGH SATURDAY MORNING BEFORE MOVING
OFFSHORE SATURDAY AFTERNOON. BEST CHANCE FOR PRECIP WILL BE ACROSS
OUR NORTHERN ZONES FRIDAY NIGHT...CLOSEST TO THE APPROACHING LOW.
WILL THEN CARRY LOW END CHC POPS ALL AREAS ON SATURDAY AS THE SFC
LOW TRAVERSES THE REGION. LOWS FRIDAY NIGHT IN THE UPR 40S TO MID
50S. HIGHS SATURDAY FROM THE 60S ON THE EASTERN SHORE TO THE
MID/UPR 70S IN OUR SW ZONES.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
WILL LEAN A LITTLE CLSR TO THE 12Z ECMWF FOR THE EXTENDED PERIOD.
A WRM FRNT WILL LIFT INTO THE AREA FRI NGT THRU SAT NGT...WITH LO
PRES EXPECTED TO MOVE EWRD ALNG THE BNDRY...AND OFF THE CST. HAVE
SML CHC FOR SHOWERS OR TSTMS DURING SAT...THEN SLGT OR SML CHC FOR
SHOWERS SAT NGT INTO SUN MORNG. HI PRES WILL BLD IN AND PROVIDE
DRY WX FOR SUN AFTN THRU MON. A COLD FRNT WILL THEN BRING AT LEAST
A SLGT CHC FOR SHOWERS OR TSTMS MON NGT AND TUE.
MIN TEMPS WILL MAINLY BE IN THE UPR 40S TO MID 50S THRU THE PERIOD.
MAX TEMPS WILL RANGE FM THE MID 60S TO UPR 70S SAT...AND MAINLY
RANGE FM THE MID 60S TO MID 70S SUN...MON AND TUE.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
A STRONG SURFACE PRESSURE GRADIENT AHEAD OF A COLD FRONT
APPROACHING FROM THE NORTH WILL CONTINUE TO DRIVE A 15-20KT SW
WIND WITH 25-30KT GUSTS THROUGH LATE AFTERNOON/EARLY EVENING. A
BROKEN LINE OF THUNDERSTORMS NEAR THE MASON-DIXON LINE AS OF
17-18Z IS EXPECTED TO DECREASE IN COVERAGE AND INTENSITY AS IT
APPROACHES THE LOCAL THE LOCAL TAF SITES VERY LATE THIS AFTERNOON.
SBY WOULD APPEAR TO HAVE THE BEST CHANCE (ALBEIT LOW) OF A TS AROUND
22-00Z...WITH A FEW SHOWERS PROGRESSING DOWN THE COAST LATER THIS
EVENING. CONFIDENCE OF SHRA OR TS AFFECTING A TERMINAL IS LOW...SO
NO WEATHER HAS BEEN INCLUDED WITH THE 18Z TAF ISSUANCE. THE COLD
FRONT CLEARS THE REGION LATER TONIGHT WITH A GUSTY NW WIND
DEVELOPING THURSDAY MORNING (ESPECIALLY NEAR THE COAST). THERE IS
A POTENTIAL FOR ANOTHER ROUND OF 15-20KT SUSTAINED WIND WITH
25-30KT GUSTS.
&&
.MARINE...
A WINDY PERIOD ON TAP TODAY THROUGH THURSDAY EVENING. TIMING OF WHEN
WNDS ACTUALLY REACH SCA LEVELS RATHER PROBLEMATIC. GIST OF FORECAST
WAS TO INCREASE SW WINDS INTO SCA LEVELS OVER THE ENTIRE MARINE AREA.
GIVEN WAA OVER COOLER WATERS...MIXING WILL BE LIMITED SO WILL STICK
WITH A MINIMAL SCA ALTHOUGH THERE COULD BE SOME GUSTS ARND 25 KTS...
ESPECIALLY NEAR THE SHORE.
LATEST GUID SUGGESTS A LULL IN WINDS THIS EVENING FOR A FEW HOUR
PERIOD EITHER SIDE OF THE FROPA...WITH CAA INCREASING THE WINDS
LATER TONIGHT. DID NOT WANT TO SPLIT UP THE HEADLINES INTO 2 EVENTS
SO WILL ONLY CARRY ONE LONG HEADLINE TO COVER BOTH SIDES OF THE
FRONT TO KEEP IT SIMPLE. DECENT CAA THURSDAY WILL INCREASE LAPSE
RATES AND ALLOW GOOD MIXING. BUFFER DATA SUGGESTS GUSTS ARND 30 KTS
SO WILL CAP THE GUSTS AT THAT LEVEL ATTM.
CONDITIONS SLOWLY IMPROVE BY FRIDAY AS HIGH PRESSURE BUILDS INTO THE
AREA ALLOWING WINDS AND SEAS TO DROP BELOW SCA LEVELS.
&&
.FIRE WEATHER...
DRY AND BREEZY CONDITIONS ON THURSDAY MAY ENHANCE FIRE DANGER
ESPECIALLY IF THERE IS NOT ANY RAIN WITH THE WEAK COLD FRONTAL
PASSAGE TONIGHT. NW WINDS WILL AVERAGE 12-20 MPH THURSDAY WITH
GUSTS UP TO 25 MPH. THE STRONGEST WINDS ARE EXPECTED DURING THE
MORNING AND EARLY AFTERNOON. ALSO...RH VALUES ARE EXPECTED TO
TUMBLE THURSDAY AFTERNOON...LIKELY FALLING INTO THE 22-32 PERCENT
RANGE. AFTER COORDINATING WITH THE FIRE AGENCIES IN MD AND
VA...WILL NOT BE ISSUING ANY HEADLINES ATTM BECAUSE CONFIDENCE IS
NOT HIGH ENOUGH THAT WE SEE WIDESPREAD 20 MPH SUSTAINED
WINDS...ESPECIALLY DURING PEAK HEATING IN THE AFTERNOON. WILL SEE
HOW MUCH RAIN FALLS TONIGHT AND THEN WILL LIKELY ISSUE AN ENHANCED
FIRE DANGER STATEMENT FOR A PORTION OF OUR MD AND VA COUNTIES
EARLY THURSDAY MORNING.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT THURSDAY NIGHT FOR
ANZ630>634-656-658.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT FRIDAY FOR ANZ650-652-654.
&&
$$
SYNOPSIS...JDM
NEAR TERM...JDM
SHORT TERM...JDM
LONG TERM...
AVIATION...AJZ
MARINE...
FIRE WEATHER...JDM
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1050 AM EDT WED MAR 28 2012
.SYNOPSIS...
A COLD FRONT WILL BRING SHOWERS WITH THE CHANCE OF THUNDERSTORMS
TO THE UPPER OHIO VALLEY REGION TODAY. SEASONABLY COOL WEATHER
WILL FOLLOW FOR THURSDAY...BUT LOOK FOR INCREASED RAIN CHANCES
AGAIN ON FRIDAY AS LOW PRESSURE APPROACHES THE AREA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A SURFACE WARM FRONT IS ADVANCING NORTHEASTWARD ACROSS THE AREA
THIS MORNING...WITH ELEVATED CONVECTION GENERALLY DRIVEN BY STEEP
MID-LEVEL LAPSE RATES SPAWNING THUNDERSTORMS THAT HAVE CROSSED THE
PITTSBURGH METRO AREA THIS MORNING. THUNDERSTORMS CONTINUE TO
BISECT THE FORECAST AREA...WITH THEIR SOUTHWARD PROGRESS LIKELY
BECOMING INCREASINGLY RETARDED AS THE AFTERNOON ENSUES DUE TO MID-
LEVEL FORCING STARTING TO SHEAR OFF TO THE EAST. SHEAR IN THE 0-6
KM LAYER WILL REMAIN ROUGHLY IN THE 50 KT RANGE THROUGH THE
AFTERNOON...WHILE INSTABILITY SHOULD INCREASE AHEAD OF A SLOWLY
SOUTHWARD ADVANCING COLD FRONT BY THE AFTERNOON...THIS MAY LEAD TO
A CHANCE OF SEVERE THUNDERSTORMS YET AGAIN THIS AFTERNOON ACROSS
THE SOUTHERN HALF OF THE FORECAST AREA. FRIES
PREVIOUS...
LOW PRESSURE MOVING ACROSS THE NORTHERN LAKES WILL PULL A COLD
FRONT ACROSS THE UPPER OHIO REGION TODAY. STRONG WARM ADVECTION IN
ADVANCE OF THE LOW HAS DEVELOPED A SHALLOW INVERSION AND WILL
INITIALLY CAP THE BOUNDARY LAYER. HOWEVER...SUFFICIENT FUEL/INSTABILITY
IS INDICATED FOR DEVELOPMENT OF SOME ELEVATED SHOWERS/POSSIBLE
THUNDERSTORMS THIS MORNING...WHICH SHOULD BECOME MORE SURFACE
BASED AS THE FRONT AND THE DAY PROGRESS. OVERALL SEVERE POTENTIAL
REMAINS LOW DESPITE FAVORABLE DEEP LAYER SHEAR WITH LIMITATIONS
IMPOSED BY A LACK OF INSTABILITY.
MODELS ARE IN GENERAL AGREEMENT IN MORE RAPID PASSAGE OF THE FRONT THAN
PREVIOUSLY DEPICTED...SO ADJUSTMENTS THIS MORNING FEATURE FADING
PRECIP PROBABILITIES DURING THE AFTERNOON. ALSO OF INTEREST FOR
THE AFTERNOON IS THE AFOREMENTIONED STRONG WIND FIELD IN CONJUNCTION
WITH THE STEEPENING LOW LAPSE RATE AS DISPLAYED VIA MODEL
SOUNDINGS. WIND GUSTS HAVE THUS BEEN INCREASED...BUT ARE EXPECTED
TO REMAIN BELOW ADVISORY THRESHOLDS.
COLDER AIR IS PROJECTED TO ADVECT OFF THE LAKES TONIGHT...AND LOW
INVERSION LEVELS SHOULD PRECLUDE MUCH THE WAY OF SHOWERS. SMALL
PRECIP PROBABILITIES WERE TWEAKED TO FAVOR AREAS IN LEE OF THE
LAKES AND THE RIDGES. PROJECTED TEMPERATURE PROFILE ALSO IS
INDICATIVE OF SOME FROZEN PRECIP OVER NORTHERN COUNTIES...SNOW
SHOWER MENTION WAS THUS ADDED.
NEAR TERM TEMPERATURES WERE FORECAST USING TWEAKED SREF MEANS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
BUILDING HIGH PRESSURE SHOULD SNUFF ANY LINGERING SHOWERS BY
MIDDAY THURSDAY...AND CONTINUED COLD ADVECTION SHOULD HOLD
TEMPERATURES A FEW DEGREES BELOW THE SEASONAL NORMALS. THE SURFACE
HIGH PRESSURE AXIS IS NAM/GFS FORECAST TO SLIDE ACROSS THE UPPER
OHIO ON THURSDAY NIGHT...AND THE AIRMASS WILL BE PLENTY DRY FOR A
PERIOD OF RADIATIONAL COOLING BEFORE WARM...MOIST ADVECTION
RESUMES IN ADVANCE OF MIDWESTERN LOW PRESSURE. ANOTHER FREEZE IS
THUS FORECAST...BUT DURATION/MAGNITUDE LOOKS TO BE LIMITED AS MID LEVEL
CLOUDINESS INCREASES.
ANOTHER SHORTWAVE IS FORECAST FOR A FRIDAY APPROACH AND SATURDAY
EXIT...HENCE CHANCE POPS WERE MAINTAINED FOR THE CLOSE OF THE WORK
WEEK...FOLLOWED BY DIMINISHED NUMBERS INTO THE WEEKEND.
SHORT TERM TEMPERATURES SHOULD AVERAGE OUT FAIRLY CLOSE TO NORMAL
AND WERE FORECAST USING A BLEND OF SREF AND GFS MOS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
PROGRESSIVE PATTERN IS GFS/ECMWF DEPICTED FOR THE LONG TERM PERIOD
AND AS SENSIBLE WEATHER WILL THUS BE SHORTWAVE DEPENDENT...FORECAST
WILL GENERALLY BE OF PERSISTENCE AND ALTERATIONS MINIMAL THIS
MORNING. WITH THE JET PROJECTED TO MEANDER OVER...OR NORTH OF THE
GREAT LAKES...TEMPERATURES WERE FORECAST ABOVE THE SEASONAL
AVERAGES USING TWEAKED HPC GUIDANCE.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
MAIN AVIATION CONCERN THROUGH 14Z WILL BE LOW LEVEL WIND SHEAR.
RECENT NAM MODEL PROFILES SHOW A VERY STRONG AND SHALLOW SURFACE
INVERSION THIS MORNING, WITH BASE 1 KFT AGL, HAVING SURFACE WINDS FROM
THE SOUTH AT 5-10 KTS. RADAR VERTICAL WIND PROFILES AND NAM MODEL
PROFILES SHOW WINDS FROM THE SOUTHWEST AND WEST 35-50 KTS IN THE
LAYER 1-2 KFT AGL WILL CONTINUE TODAY.
BLEND OF HIGH RESOLUTION MODEL OUTPUT SHOW VERTICAL MIXING,
ACCOMPANYING THE COLD FRONTAL PASSAGE 14Z-18Z, DEEPENING THE SURFACE
LAYER WHICH WILL THEN TAP THE FAST WINDS ALOFT AND CAUSE SOUTHWEST
TO WEST SURFACE WINDS TO GUST TO 25-30 KTS THROUGH 22Z.
FLIGHT CONDITIONS SHOULD BE MAINLY VFR THROUGH 06Z, DESPITE PASSAGE OF
FRONTAL BAND OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
14Z-18Z, AS HAVE TOO LOW CONFIDENCE TO MENTION. TIMING OF SHOWERS
HAS BEEN BASED ON RECENT WRF-NMM AND HRRR MODEL OUTPUT.
COLD POOL STRATOCUMULUS LATE TONIGHT INTO THURSDAY MORNING MAY
PROMOTE A PERIOD OF MVFR CEILINGS.
OUTLOOK...THURSDAY THROUGH SUNDAY...
VFR THURSDAY AFTERNOON INTO FRIDAY. RESTRICTIONS THEN POSSIBLE DUE
TO SHOWERS FROM A LOW PRESSURE SYSTEM PASSAGE FRIDAY NIGHT INTO
SATURDAY, AND LINGERING COLD POOL CLOUDS SUNDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
826 AM EDT WED MAR 28 2012
.SYNOPSIS...
A COLD FRONT WILL BRING SHOWERS WITH THE CHANCE OF THUNDERSTORMS
TO THE UPPER OHIO VALLEY REGION TODAY. SEASONABLY COOL WEATHER
WILL FOLLOW FOR THURSDAY...BUT LOOK FOR INCREASED RAIN CHANCES
AGAIN ON FRIDAY AS LOW PRESSURE APPROACHES THE AREA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ONGOING THUNDERSTORMS IN THE NORTHERN HALF OF THE CWA HAVE BEEN
YIELDING REPORTS OF NEARLY QUARTER SIZED HAIL. INSTABILITY LOOKS
TO BE VERY LEAN...HOWEVER 50-60 KTS OF 0-6 KM BULK UNIDIRECTIONAL
SHEAR ARE MANAGING TO YIELD DECENT ENOUGH SUPPORT TO MANAGE TO
SUSTAIN BRIEFLY STRONG UPDRAFTS. THE FORECAST HAS BEEN UPDATED TO
INCLUDE GUSTY WINDS AND LARGE HAIL WITH THE THUNDERSTORMS ACROSS
THE NORTHERN TIER OF COUNTIES THIS MORNING. FRIES
PREVIOUS...
LOW PRESSURE MOVING ACROSS THE NORTHERN LAKES WILL PULL A COLD
FRONT ACROSS THE UPPER OHIO REGION TODAY. STRONG WARM ADVECTION IN
ADVANCE OF THE LOW HAS DEVELOPED A SHALLOW INVERSION AND WILL
INITIALLY CAP THE BOUNDARY LAYER. HOWEVER...SUFFICIENT FUEL/INSTABILITY
IS INDICATED FOR DEVELOPMENT OF SOME ELEVATED SHOWERS/POSSIBLE
THUNDERSTORMS THIS MORNING...WHICH SHOULD BECOME MORE SURFACE
BASED AS THE FRONT AND THE DAY PROGRESS. OVERALL SEVERE POTENTIAL
REMAINS LOW DESPITE FAVORABLE DEEP LAYER SHEAR WITH LIMITATIONS
IMPOSED BY A LACK OF INSTABILITY.
MODELS ARE IN GENERAL AGREEMENT IN MORE RAPID PASSAGE OF THE FRONT THAN
PREVIOUSLY DEPICTED...SO ADJUSTMENTS THIS MORNING FEATURE FADING
PRECIP PROBABILITIES DURING THE AFTERNOON. ALSO OF INTEREST FOR
THE AFTERNOON IS THE AFOREMENTIONED STRONG WIND FIELD IN CONJUNCTION
WITH THE STEEPENING LOW LAPSE RATE AS DISPLAYED VIA MODEL
SOUNDINGS. WIND GUSTS HAVE THUS BEEN INCREASED...BUT ARE EXPECTED
TO REMAIN BELOW ADVISORY THRESHOLDS.
COLDER AIR IS PROJECTED TO ADVECT OFF THE LAKES TONIGHT...AND LOW
INVERSION LEVELS SHOULD PRECLUDE MUCH THE WAY OF SHOWERS. SMALL
PRECIP PROBABILITIES WERE TWEAKED TO FAVOR AREAS IN LEE OF THE
LAKES AND THE RIDGES. PROJECTED TEMPERATURE PROFILE ALSO IS
INDICATIVE OF SOME FROZEN PRECIP OVER NORTHERN COUNTIES...SNOW
SHOWER MENTION WAS THUS ADDED.
NEAR TERM TEMPERATURES WERE FORECAST USING TWEAKED SREF MEANS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
BUILDING HIGH PRESSURE SHOULD SNUFF ANY LINGERING SHOWERS BY
MIDDAY THURSDAY...AND CONTINUED COLD ADVECTION SHOULD HOLD
TEMPERATURES A FEW DEGREES BELOW THE SEASONAL NORMALS. THE SURFACE
HIGH PRESSURE AXIS IS NAM/GFS FORECAST TO SLIDE ACROSS THE UPPER
OHIO ON THURSDAY NIGHT...AND THE AIRMASS WILL BE PLENTY DRY FOR A
PERIOD OF RADIATIONAL COOLING BEFORE WARM...MOIST ADVECTION
RESUMES IN ADVANCE OF MIDWESTERN LOW PRESSURE. ANOTHER FREEZE IS
THUS FORECAST...BUT DURATION/MAGNITUDE LOOKS TO BE LIMITED AS MID LEVEL
CLOUDINESS INCREASES.
ANOTHER SHORTWAVE IS FORECAST FOR A FRIDAY APPROACH AND SATURDAY
EXIT...HENCE CHANCE POPS WERE MAINTAINED FOR THE CLOSE OF THE WORK
WEEK...FOLLOWED BY DIMINISHED NUMBERS INTO THE WEEKEND.
SHORT TERM TEMPERATURES SHOULD AVERAGE OUT FAIRLY CLOSE TO NORMAL
AND WERE FORECAST USING A BLEND OF SREF AND GFS MOS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
PROGRESSIVE PATTERN IS GFS/ECMWF DEPICTED FOR THE LONG TERM PERIOD
AND AS SENSIBLE WEATHER WILL THUS BE SHORTWAVE DEPENDENT...FORECAST
WILL GENERALLY BE OF PERSISTENCE AND ALTERATIONS MINIMAL THIS
MORNING. WITH THE JET PROJECTED TO MEANDER OVER...OR NORTH OF THE
GREAT LAKES...TEMPERATURES WERE FORECAST ABOVE THE SEASONAL
AVERAGES USING TWEAKED HPC GUIDANCE.
&&
.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
MAIN AVIATION CONCERN THROUGH 14Z WILL BE LOW LEVEL WIND SHEAR.
RECENT NAM MODEL PROFILES SHOW A VERY STRONG AND SHALLOW SURFACE
INVERSION THIS MORNING, WITH BASE 1 KFT AGL, HAVING SURFACE WINDS FROM
THE SOUTH AT 5-10 KTS. RADAR VERTICAL WIND PROFILES AND NAM MODEL
PROFILES SHOW WINDS FROM THE SOUTHWEST AND WEST 35-50 KTS IN THE
LAYER 1-2 KFT AGL WILL CONTINUE TODAY.
BLEND OF HIGH RESOLUTION MODEL OUTPUT SHOW VERTICAL MIXING,
ACCOMPANYING THE COLD FRONTAL PASSAGE 14Z-18Z, DEEPENING THE SURFACE
LAYER WHICH WILL THEN TAP THE FAST WINDS ALOFT AND CAUSE SOUTHWEST
TO WEST SURFACE WINDS TO GUST TO 25-30 KTS THROUGH 22Z.
FLIGHT CONDITIONS SHOULD BE MAINLY VFR THROUGH 06Z, DESPITE PASSAGE OF
FRONTAL BAND OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
14Z-18Z, AS HAVE TOO LOW CONFIDENCE TO MENTION. TIMING OF SHOWERS
HAS BEEN BASED ON RECENT WRF-NMM AND HRRR MODEL OUTPUT.
COLD POOL STRATOCUMULUS LATE TONIGHT INTO THURSDAY MORNING MAY
PROMOTE A PERIOD OF MVFR CEILINGS.
OUTLOOK...THURSDAY THROUGH SUNDAY...
VFR THURSDAY AFTERNOON INTO FRIDAY. RESTRICTIONS THEN POSSIBLE DUE
TO SHOWERS FROM A LOW PRESSURE SYSTEM PASSAGE FRIDAY NIGHT INTO
SATURDAY, AND LINGERING COLD POOL CLOUDS SUNDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
646 AM EDT WED MAR 28 2012
.SYNOPSIS...
A COLD FRONT WILL BRING SHOWERS WITH THE CHANCE OF THUNDERSTORMS
TO THE UPPER OHIO VALLEY REGION TODAY. SEASONABLY COOL WEATHER
WILL FOLLOW FOR THURSDAY...BUT LOOK FOR INCREASED RAIN CHANCES
AGAIN ON FRIDAY AS LOW PRESSURE APPROACHES THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
HAVE DECIDED TO EXPAND THE SPC SLIGHT RISK AREA A FEW COUNTIES
NORTHWARD TO INCLUDE GARRETT COUNTY AND THE NORTHERN WEST VIRGINIA
ZONES EXCLUDING THE PANHANDLE. SHOULD THUNDERSTORM SUPPORT SURVIVE
INTO THE AFTERNOON AS FORECAST...DAMAGING WIND GUSTS WILL BE
POSSIBLE IN THE DEEPENING MIXING LAYER. THIS MENTION WAS INCLUDED
IN THE HAZARDOUS WEATHER OUTLOOK.
PREVIOUS...
LOW PRESSURE MOVING ACROSS THE NORTHERN LAKES WILL PULL A COLD
FRONT ACROSS THE UPPER OHIO REGION TODAY. STRONG WARM ADVECTION IN
ADVANCE OF THE LOW HAS DEVELOPED A SHALLOW INVERSION AND WILL
INITIALLY CAP THE BOUNDARY LAYER. HOWEVER...SUFFICIENT FUEL/INSTABILITY
IS INDICATED FOR DEVELOPMENT OF SOME ELEVATED SHOWERS/POSSIBLE
THUNDERSTORMS THIS MORNING...WHICH SHOULD BECOME MORE SURFACE
BASED AS THE FRONT AND THE DAY PROGRESS. OVERALL SEVERE POTENTIAL
REMAINS LOW DESPITE FAVORABLE DEEP LAYER SHEAR WITH LIMITATIONS
IMPOSED BY A LACK OF INSTABILITY.
MODELS ARE IN GENERAL AGREEMENT IN MORE RAPID PASSAGE OF THE FRONT THAN
PREVIOUSLY DEPICTED...SO ADJUSTMENTS THIS MORNING FEATURE FADING
PRECIP PROBABILITIES DURING THE AFTERNOON. ALSO OF INTEREST FOR
THE AFTERNOON IS THE AFOREMENTIONED STRONG WIND FIELD IN CONJUNCTION
WITH THE STEEPENING LOW LAPSE RATE AS DISPLAYED VIA MODEL
SOUNDINGS. WIND GUSTS HAVE THUS BEEN INCREASED...BUT ARE EXPECTED
TO REMAIN BELOW ADVISORY THRESHOLDS.
COLDER AIR IS PROJECTED TO ADVECT OFF THE LAKES TONIGHT...AND LOW
INVERSION LEVELS SHOULD PRECLUDE MUCH THE WAY OF SHOWERS. SMALL
PRECIP PROBABILITIES WERE TWEAKED TO FAVOR AREAS IN LEE OF THE
LAKES AND THE RIDGES. PROJECTED TEMPERATURE PROFILE ALSO IS
INDICATIVE OF SOME FROZEN PRECIP OVER NORTHERN COUNTIES...SNOW
SHOWER MENTION WAS THUS ADDED.
NEAR TERM TEMPERATURES WERE FORECAST USING TWEAKED SREF MEANS.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
BUILDING HIGH PRESSURE SHOULD SNUFF ANY LINGERING SHOWERS BY
MIDDAY THURSDAY...AND CONTINUED COLD ADVECTION SHOULD HOLD
TEMPERATURES A FEW DEGREES BELOW THE SEASONAL NORMALS. THE SURFACE
HIGH PRESSURE AXIS IS NAM/GFS FORECAST TO SLIDE ACROSS THE UPPER
OHIO ON THURSDAY NIGHT...AND THE AIRMASS WILL BE PLENTY DRY FOR A
PERIOD OF RADIATIONAL COOLING BEFORE WARM...MOIST ADVECTION
RESUMES IN ADVANCE OF MIDWESTERN LOW PRESSURE. ANOTHER FREEZE IS
THUS FORECAST...BUT DURATION/MAGNITUDE LOOKS TO BE LIMITED AS MID LEVEL
CLOUDINESS INCREASES.
ANOTHER SHORTWAVE IS FORECAST FOR A FRIDAY APPROACH AND SATURDAY
EXIT...HENCE CHANCE POPS WERE MAINTAINED FOR THE CLOSE OF THE WORK
WEEK...FOLLOWED BY DIMINISHED NUMBERS INTO THE WEEKEND.
SHORT TERM TEMPERATURES SHOULD AVERAGE OUT FAIRLY CLOSE TO NORMAL
AND WERE FORECAST USING A BLEND OF SREF AND GFS MOS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
PROGRESSIVE PATTERN IS GFS/ECMWF DEPICTED FOR THE LONG TERM PERIOD
AND AS SENSIBLE WEATHER WILL THUS BE SHORTWAVE DEPENDENT...FORECAST
WILL GENERALLY BE OF PERSISTENCE AND ALTERATIONS MINIMAL THIS
MORNING. WITH THE JET PROJECTED TO MEANDER OVER...OR NORTH OF THE
GREAT LAKES...TEMPERATURES WERE FORECAST ABOVE THE SEASONAL
AVERAGES USING TWEAKED HPC GUIDANCE.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
MAIN AVIATION CONCERN THROUGH 14Z WILL BE LOW LEVEL WIND SHEAR.
RECENT NAM MODEL PROFILES SHOW A VERY STRONG AND SHALLOW SURFACE
INVERSION THIS MORNING, WITH BASE 1 KFT AGL, HAVING SURFACE WINDS FROM
THE SOUTH AT 5-10 KTS. RADAR VERTICAL WIND PROFILES AND NAM MODEL
PROFILES SHOW WINDS FROM THE SOUTHWEST AND WEST 35-50 KTS IN THE
LAYER 1-2 KFT AGL WILL CONTINUE TODAY.
BLEND OF HIGH RESOLUTION MODEL OUTPUT SHOW VERTICAL MIXING,
ACCOMPANYING THE COLD FRONTAL PASSAGE 14Z-18Z, DEEPENING THE SURFACE
LAYER WHICH WILL THEN TAP THE FAST WINDS ALOFT AND CAUSE SOUTHWEST
TO WEST SURFACE WINDS TO GUST TO 25-30 KTS THROUGH 22Z.
FLIGHT CONDITIONS SHOULD BE MAINLY VFR THROUGH 06Z, DESPITE PASSAGE OF
FRONTAL BAND OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
14Z-18Z, AS HAVE TOO LOW CONFIDENCE TO MENTION. TIMING OF SHOWERS
HAS BEEN BASED ON RECENT WRF-NMM AND HRRR MODEL OUTPUT.
COLD POOL STRATOCUMULUS LATE TONIGHT INTO THURSDAY MORNING MAY
PROMOTE A PERIOD OF MVFR CEILINGS.
OUTLOOK...THURSDAY THROUGH SUNDAY...
VFR THURSDAY AFTERNOON INTO FRIDAY. RESTRICTIONS THEN POSSIBLE DUE
TO SHOWERS FROM A LOW PRESSURE SYSTEM PASSAGE FRIDAY NIGHT INTO
SATURDAY, AND LINGERING COLD POOL CLOUDS SUNDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
404 PM EDT WED MAR 28 2012
.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 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 133 PM EDT WED MAR 28 2012
EXPECT GUSTY WINDS TO DIMINISH THIS PERIOD AND VEER TO ENE AT ALL
SITES AS HI PRES RDG/WEAKER PRES GRADIENT BUILDS INTO THE UPR GRT
LKS. ALTHOUGH MORE ACYC FLOW/SOME LLVL DRYING WL RESULT IN
CONDITIONS IMPROVING TO VFR BY THIS EVNG...EXTENSIVE LO CLD/CIGS
OBSERVED UPSTREAM SUGGEST A MORE PESSIMISTIC CIG FORECAST THAN SHOWN
ON PREVIOUS TAFS. OPTED TO FCST AN MVFR CIG LATER TNGT/EARLY THU AT
CMX/SAW DURING TIMES OF UPSLOPE FLOW. THE BEST CHC OF A MORE
PERSISTENT VFR CONDITION WL BE AT IWD...WHERE EXPECTED ENE LLVL FLOW
WL DOWNSLOPE.
&&
.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.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...JLA
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
132 AM EDT WED MAR 28 2012
.SYNOPSIS...
ISSUED AT 408 PM EDT TUE MAR 27 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW POTENT NEGATIVELY
TILTED SHRTWV/STACKED LO MOVING ENEWD THRU NRN MN ON TOP OF MEAN RDG
OVER THE SE CONUS. PCPN/WARM CONVEYOR BELT WELL E OF THE LO HAS
MOVED E OF THE CWA...BUT LO CLDS LINGER IN THE RELATIVELY MOIST LYR
ASSOCIATED WITH SHARP WAD INVRN DEPICTED ON THE 12Z RAOBS. SKIES ARE
MOCLR OVER MN UNDER THE DRY SLOT/JET SURGE REGION OF THE LO...AND
TEMPS HAVE RISEN WELL INTO THE 50S AND 60S IN THAT AREA. DESPITE
THIS SHARP WAD STABILITY...GUSTY S WINDS UP TO 50 MPH UNDER SHARP
PRES GRADIENT BTWN THE LO AND RETREATING HI PRES OVER SE ONTARIO
HAVE IMPACTED LOCATIONS NEAR THE LK SUP SHORE...PROMPTING ISSUANCE
OF WIND ADVY. IN FACT...THE 12Z MPX RAOB INDICATED A WIND SPEED OF
61KTS AT 3K FT AGL WITHIN THE STABLE INVRN LYR. THE S WIND OFF THE
RELATIVELY CHILLY LK MI WATERS HAVE ENHANCED THE LLVL STABILITY AND
PREVENTED THE WINDS IN THAT AREA FM BEING AS STRONG AS NEAR LK SUP.
FARTHER TO THE W...DEEP WRAP ARND MSTR SHOWN ON THE 12Z BISMARCK
RAOB IS MOVING INTO NW NW IN THE WAKE OF THE DEPARTING LO.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 408 PM EDT TUE MAR 27 2012
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON WINDS/CLD TRENDS AND
PSBL WRAP ARND -SHRA AS MN LO MOVES ACRS NRN LK SUP AND INTO SE
ONTARIO ON WED.
TNGT...SHRTWV/CLOSED LO IN MN ARE PROGGED TO MOVE INTO SE ONTARIO
JUST NE OF THE SAULT BY 12Z WED. AS THE PRES GRADIENT WEAKENS AT
LEAST TEMPORARILY WITH THE APRCH OF THE SFC LO...EXPECT WINDS TO
DIMINISH LATE THIS AFTN/EARLY EVNG. SO WL LET THE GOING WIND ADVY
EXPIRE AT 21Z AS SCHEDULED. ALTHOUGH THE EARLY EVNG WL BE PCPN FREE
FOR THE MOST PART UNDER DRY SLOT...MORE CLDS/SCT -SHRA WL ARRIVE FM
THE W AS THE WRAP ARND MSTR ACCOMPANYING THE EWARD MOVING LO PRES
SLIDES INTO THE UPR LKS. STRONG W H925 WINDS UP TO 40-50 KTS ON THE
WRN FLANK OF THE LO WL ADVECT MUCH COOLER AIR INTO THE AREA...WITH
H85 TEMPS FCST AS LO AS -2C OR -3C OVER THE W BY 12Z...BUT FCST WBLB
ZERO HGT WELL ABV 1K FT SUGS THE PCPN WL REMAIN MAINLY IN THE FORM
OF RA EXCEPT OVER THE HIER TERRAIN OF THE W LATE. EXPECT STRONG W
WINDS TO IMPACT THE W LATE AS WELL...WITH WIND GUSTS APRCHG ADVY LVL
AGAIN OVER THE FAR W S OF CMX WHERE THE CORE OF STRONGEST WINDS
COINCIDES WITH THE INCOMING H85 THERMAL TROF. CONSIDERED EXTENDING
WIND ADVY FOR THE KEWEENAW...BUT AXIS OF STRONGER WINDS POINTING
TOWARD THIS EXPOSED AREA DOES NOT COINCIDE WITH THERMAL TROFFING/
REDUCED STABILITY THAT WOULD ENHANCE MIXING.
WED...AS THE CLOSED LO TO THE E MOVES FARTHER AWAY...SFC HI PRES RDG
WL BLD INTO THE AREA UNDER RISING H5 AHEAD OF PROGRESSIVE UPR RDG IN
THE PLAINS. MRNG -SHRA...MIXED WITH SN PER LOWER WBLB ZERO HGTS AS
H85 TEMPS FALL TO ARND -5C...MAINLY IN THE UPSLOPE AREAS OVER THE
NRN TIER WL DIMINISH WITH TIME UNDER NEGATIVE DYNAMICS/MID LVL
DRYING AND GRDLY MORE ACYC FLOW... BUT FCST SDNGS SUG PLENTY OF LO
CLD WL LINGER...SO TENDED TOWARD THE LOWER END OF GUIDANCE FOR
TEMPS. AS THE LO MOVES AWAY AND HI PRES MOVES TOWARD THE AREA...THE
WINDS WL DIMINISH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 408 PM EDT TUE MAR 27 2012
WED NIGHT...H925 TEMPS AROUND -6C WILL LEAD TO ENOUGH LK INSTABILITY
TO KEEP CLOUDS GOING THROUGH MUCH OF THE NIGHT FOR LOCATIONS FAVORED
BY VEERING N TO NE WINDS NEAR LK SUPERIOR. LINGERED SLIGHT CHANCES
THROUGH THE EVENING FOR THE NRLY FAVORED LOCATIONS BEFORE
DIMINISHING IT OVERNIGHT. DID HOLD ON TO THE SLIGHTS LONGER FOR THE
UPSLOPE LOCATIONS IN NCNTRL UPPER MI...ALTHOUGH THE LOWERING
INVERSION WILL LIMIT CLOUD DEPTH.
THURS SHOULD BE A SIMILAR DAY TO YESTERDAY WITH HUDSON BAY HIGH
PRESSURE RIDGE OVER UPPER MI. NE WINDS WILL PULL DRIER AIR INTO
UPPER MI AND LEAD TO A MOSTLY SUNNY DAY OVER THE EAST HALF. FARTHER
WEST...MID CLOUDS WILL BE WORKING OVER THE AREA THROUGH THE
AFTERNOON...ALONG WITH SOME SHOWERS OVER WRN LK SUPERIOR...AHEAD OF
THE APPROACHING SHORTWAVE. HIGHS WILL BE WARMEST INTERIOR AWAY FROM
THE LK SUPERIOR INFLUENCE...WHICH WILL ALLOW FOR DEEPER MIXING AND
HIGHS RISING INTO THE MID-UPPER 40S. OTHERWISE...LOCATIONS NEAR LAKE
SUPERIOR WILL BE IN THE UPPER 30S AND LOWER 40S. DEWPOINTS ARE THE
MAIN ADJUSTMENT TO THE FORECAST...AS MODELS ARE COMING INTO BETTER
AGREEMENT WITH ML DEWPOINTS FALLING INTO THE SINGLE DIGITS ABOVE
ZERO OVER THE ERN CWA. WILL DROP TD VALUES AGAIN SEVERAL DEGREES
OVER THE ERN CWA INTO THE UPPER TEENS. MAY NEED TO DROP THEM EVEN
MORE...SINCE MIXED LAYER DEWPOINTS VERIFIED FAIRLY WELL YESTERDAY.
THURS NIGHT...CLEAR INITIALLY AND WITH THE LIGHT WINDS OVER THE ERN
CWA...SHOULD SEE A QUICK FALL IN TEMPS DURING THE EVENING HOURS. BUT
INCREASING CLOUDS AHEAD OF THE APPROACHING SHORTWAVE WILL CAUSE THE
TEMPS TO RISE THROUGH THE NIGHT. TRIED TO SHOW A QUICK DROP IN
THE EVENING...BUT UNSURE THE AMOUNT OF WARMING WITH LIMITED
WINDS AND MAINLY MID-HIGH CLOUDS...SO HAVE HELD THEM STEADY. SHOWERS
ENTERING THE WRN HALF OF THE CWA DURING THE OVERNIGHT
HOURS. ASSOCIATED WITH H850-700 WAA IN THE EVENING...WHICH THEN
FOCUSES FARTHER S THROUGH THE OVERNIGHT HOURS. THIS SHOULD DIMINISH
THE COVERAGE OF THE SHOWERS AS THEY PUSH E. PTYPE IS TRICKY SINCE IT
WILL BE FALLING AS SNOW...BUT THEN AN ISOTHERMAL LAYER AT 0C LOOKS
TO SETUP FROM 2-6KFT BEFORE NEAR SFC TEMPS BELOW 2KFT WILL BE ABOVE
FREEZING. THIS CREATES A SNOW/RAIN MIX SCENARIO AND SMALL
DIFFERENCES IN THE THERMAL PROFILE WILL DETERMINE PCPN TYPE.
THUS...WENT WITH A RAIN/SNOW MIX OVER UPPER MI...WITH BETTER SNOW
CHANCES TO THE NE HALF.
FRI...MODELS BECOMING MORE CONSISTENT ON THE BULK OF THE PCPN GOING
S OF THE CWA WITH THE SHORTWAVE WEAKENING AS IT TRIES TO PUSH
THROUGH THE UPPER RIDGE AND FOCUSING OF THE BETTER H850-700 WAA
FARTHER SE OVER LK MI AND LOWER MI. THEREFORE...HAVE A DIMINISHING
TREND OVER THE ERN CWA THROUGH THE DAY DUE TO THE PERSISTENT LLVL
DRY AIR FROM THE HUDSON BAY HIGH. SHOULD BE A MIX OF RAIN/SNOW IN
THE MORNING BEFORE DAYTIME HEATING WOULD CHANGE ANY LINGERING PCPN
TO RAIN.
EXTENDED /FRIDAY NIGHT THROUGH TUESDAY/...
HPC FOLLOWED A 00Z GFS/ECMWF ENS MEAN FOR DAYS 5-7...SINCE THERE IS
DECENT CONSISTENCY IN THE TROUGH MOVING OUT OF THE WRN CONUS DURING
THAT TIMEFRAME.
ANOTHER SHORTWAVE MOVES THROUGH THE UPPER GREAT LKS FOR FRI NIGHT
INTO SAT. MOISTURE IS FAIRLY LIMITED...ALONG WITH H850-700 Q-VECTOR
CONV...SO THINK OVERALL PCPN CHANCES WILL BE LIMITED.
UPPER RIDGE BUILDS OVER THE AREA ON SAT NIGHT INTO SUN NIGHT IN
RESPONSE TO UPPER TROUGH OVER THE WRN CONUS SHIFTING INTO THE
PLAINS STATES. DETERMINISTIC RUNS STILL DIFFERING IN THE
INTENSITY/AMPLITUDE OF THIS TROUGH...WITH THE 00Z GFS MUCH DEEPER
AND THE 00Z ECMWF BROADER AND OVER THE CNTRL/NRN PLAINS. 12Z GFS
HAS TRENDED TOWARDS THE 00Z ECMWF AND WILL FOLLOW THE
HPC SOLN AND HAVE THE BROAD SFC LOW OVER THE CNTRL/NRN PLAINS ON SUN
SLIDING SE THROUGH THE UPPER MISS VALLEY AND LOWER GREAT LKS THROUGH
TUES. BEFORE THAT...WARM FRONT LOOKS TO SETUP SOMEWHERE OVER THE
UPPER GREAT LKS OR SRN ONTARIO...WHICH WOULD HAVE A LARGE AFFECT ON
HIGHS. DIFFERENCES IN MODEL SOLNS GIVE UNCERTAINTY IN TEMPS FOR
SUN...AS H850 TEMPS RANGE FROM 7-14C. MAY NOT MIX QUITE THAT
HIGH...BUT MIXING TO H900 WOULD STILL YIELD HIGHS IN THE 60S. SO
HAVE BUMPED UP THE EXISTING FORECAST A FEW DEGREES.
HEADING INTO SUN NIGHT THROUGH TUES...AREA WILL BE ON THE
NRN FRINGES OF THE SFC LOW FEATURES. IF THE LOW TRENDS TOWARDS THE
00Z GFS...WILL LIKELY BE DRY...BUT IF THE 00Z ECMWF AND 12Z GFS ARE
CORRECT WE/LL HAVE BETTER SHOT OF SEEING PCPN. DON/T SEE ANY REASON
TO GO ANYTHING MORE THAN LOW END CHANCES AND WILL KEEP THE PCPN AS
RAIN WITH THE ABUNDANT WARM AIR REMAINING OVER THE AREA.
AS THIS UPPER TROUGH SHIFTS E FOR THE END OF THE WEEK...COULD SEE A
TRANSITION TO A BELOW NORMAL TEMPERATURE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 131 AM EDT WED MAR 28 2012
EXPECT STRONG WEST WINDS IN THE WAKE OF A SFC TROUGH/COLD FRONT AT
KIWD AND KCMX WITH GUSTS OF 30 TO 35KTS EXPECTED THROUGH
TONIGHT...ESPECIALLY AT KCMX. WITH COLDER AIR MOVING IN BEHIND THE
FRONT...LOW CLOUDS IN THE MVFR TO OCCASIONAL IFR RANGE ALONG WITH
LAKE EFFECT RAIN SHOWERS WILL ALSO MOVE INTO KIWD AND KCMX. IT MAY
GET COLD ENOUGH AT KIWD FOR SOME SNOW TO MIX IN WITH THE RAIN LATE
TONIGHT AND WED MORNING. MVFR CLOUD DECK WILL ALSO MOVE INTO KSAW
LATE TONIGHT BUT RAIN SHOWERS SHOULD GENERALLY HOLD OFF UNTIL AFT
12Z WED WHEN WINDS VEER NW. WINDS WILL DIMINISH AND CIGS SHOULD
IMPROVE...ESPECIALLY FM THE WEST LATE WED AS A HIGH PRESSURE RIDGE
BUILDS IN FROM NRN ONTARIO.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 408 PM EDT TUE MAR 27 2012
ALTHOUGH THE GOING S GALES OVER THE E HALF OF LK SUP WILL DIMINISH
BY EARLY THIS EVENING AS LO PRES IN MN/WEAKER PRES GRADIENT
ARRIVE...A STRONGER W TO NW WIND WILL REDEVELOP LATER TONIGHT AS THE
LO MOVES TO THE E ACROSS LAKE SUP...WITH MORE GALE FORCE WINDS OVER
MAINLY THE W AND NCENTRAL AT TIMES INTO WED MORNING WHEN THE ARRIVAL
OF COLDER AIR AS WELL WILL RESULT IN ENHANCED MIXING. THE APPROACH
OF A HI PRES RIDGE AND WEAKER PRES GRADIENT WILL RESULT IN
DIMINISHING WINDS BY WED AFTERNOON.
HIGH PRESSURE RIDGE OVER THE AREA ON WED NIGHT WILL LEAD TO
DIMINISHING WINDS AS THEY BACK TO THE NE. EXPECT WINDS TO STAY
BELOW 20KTS FOR MUCH OF THE PERIOD AS A SERIES OF WEAK DISTURBANCES
AND HIGH PRESSURE RIDGES MOVE ACROSS THE AREA THROUGH THE WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 11 AM EDT THIS MORNING FOR LSZ266.
GALE WARNING FROM 5 AM TO 11 AM EDT THIS MORNING FOR LSZ244-245-
264.
GALE WARNING UNTIL 5 AM EDT /4 AM CDT/ EARLY THIS MORNING FOR
LSZ241-242-263.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...SRF
AVIATION...VOSS
MARINE...KC/SRF
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1029 PM CDT THU MAR 29 2012
.UPDATE...
ISSUED AT 949 PM CDT THU MAR 29 2012
CLOUD COVER AND SCATTERED LIGHT SHOWERS SHIFTING E OF THE
FORECAST AREA LATE THIS EVNG...WITH A CLEAR SKY FOR MOST OF OUR
AREA. CONVECTIVE CLUSTERS MOVING FROM ERN NEBRASKA AND NWRN MO
NEWD THROUGH SWRN AND S CNTRL IA IN AREA OF STRONG 850 MB
WAA...MOISTURE CONVERGENCE AND THETA E ADVECTION ON NOSE OF SLY
LOW LEVEL JET. THIS ACTIVITY WAS ALSO AHEAD OF A SHORTWAVE TROUGH
MOVING EWD THROUGH THE NRN PLAINS...AND NEAR AND N-NE OF SFC LOW
OVER SERN NEBRASKA AND N OF WARM FRONT EXTENDING SE OF SFC LOW.
MOST OF THESE STORMS WERE MOVING EWD OR NEWD. IF ENOUGH OF AN
ORGANIZED COLD POOL DEVELOPS COULD SEE SOME OF THIS ACTIVITY
DROPPING SEWD. IT APPEARS THAT MOST OF THE SHOWER AND
THUNDERSTORM ACTIVITY WILL BE MAINLY CONFINED TO NERN MO AND W
CNTRL IL LATE TGT AHEAD OF THE SFC LOW MOVING EWD ALONG THE MO IA
BORDER AND N OF THE WARM FRONT EXTENDING SE OF THE SFC LOW. HAD TO
LOWER TEMPERATURES OVER NERN MO AND W CNTRL IL WHERE IT HAS FALLEN
INTO THE LOWER 50S. TEMPERATURES HERE SHOULD REMAIN NEARLY STEADY
OR ACTUALLY RISE A LITTLE OVERNIGHT.
GKS
&&
.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 553 PM CDT THU MAR 29 2012
A PRETTY QUIET EVENING LOOKS ON TAP WITH VFR CONDITIONS AND MOSTLY
CLEAR SKIES DOMINATING. SHOWERS FROM EARLIER TODAY HAVE PUSHED TO
THE EAST WITH CLEAR OR CLEARING SKIES IN THE WAKE.
A WARM FRONT REMAINS ACROSS FAR SRN IL THROUGH SE MO INTO NW
MO...THEN TURNS WESTWARD ALONG THE NEBRASKA/KANSAS BORDER TO A LOW
PRESSURE SYSTEM NEAR KBIE. A COLD FRONT THEN EXTENDS SWWD FROM
THIS SURFACE LOW INTO CENTRAL KS. THUNDERSTORMS ARE EXPECTED TO
DEVELOP AND INCREASE IN COVERAGE FROM SE NEBRASKA INTO NW MO TO
THE NORTH OF THE WARM FRONT...WHILE ALSO DEVELOPING ALONG THE
ADVANCING COLD FRONT. THE SURFACE LOW AND COLD FRONT ARE THEN
FORECAST TO TRACK EASTWARD TONIGHT AND FRIDAY WITH A THREAT OF
SHOWERS AND THUNDERSTORMS IN ADVANCE OF IT. FOR KUIN AND KCOU THIS
THREAT WILL BE OVERNIGHT TONIGHT TO JUST PAST DAWN ON FRIDAY...AND
HAVE KEPT WITH VCTS AND CB CLOUD GROUPS FOR NOW. ANY THREAT IN THE
ST LOUIS AREA SHOULD BE FROM MID MORNING THROUGH EARLY AFTERNOON
ALONG AND AHEAD OF THE ADVANCING COLD FRONT.
SPECIFICS FOR KSTL...
A PRETTY QUIET NIGHT LOOKS ON TAP WITH VFR CONDITIONS AND MOSTLY
CLEAR SKIES DOMINATING THIS EVENING AND THEN INCREASING HIGH
CLOUDS LATER TONIGHT.
SHOWERS FROM EARLIER TODAY HAVE PUSHED TO THE EAST WITH CLEAR OR
CLEARING SKIES IN THE WAKE. A WARM FRONT TO THE SOUTH WILL MOVE
NORTHWARD THROUGH THE TERMINAL NEAR OR JUST AFTER MIDNIGHT WITH
THE WIND VEERING TO THE SOUTH. ANY THREAT OF SHOWERS AND
THUNDERSTORMS IN THE ST LOUIS AREA SHOULD BE FROM MID MORNING
FRIDAY THROUGH EARLY AFTERNOON ALONG AND AHEAD OF THE ADVANCING
COLD FRONT. CONFIDENCE IS TOO LOW TO INCLUDE THIS FAR OUT IN THE
FORECAST AND FOR NOW HAVE JUST MENTIONED VCSH AND A CB CLOUD GROUP.
GLASS
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 59 77 53 79 / 40 40 10 10
QUINCY 53 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 / 30 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...UPDATED AVIATION
NWS ST LOUIS MO
610 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 553 PM CDT THU MAR 29 2012
A PRETTY QUIET EVENING LOOKS ON TAP WITH VFR CONDITIONS AND MOSTLY
CLEAR SKIES DOMINATING. SHOWERS FROM EARLIER TODAY HAVE PUSHED TO
THE EAST WITH CLEAR OR CLEARING SKIES IN THE WAKE.
A WARM FRONT REMAINS ACROSS FAR SRN IL THROUGH SE MO INTO NW
MO...THEN TURNS WESTWARD ALONG THE NEBRASKA/KANSAS BORDER TO A LOW
PRESSURE SYSTEM NEAR KBIE. A COLD FRONT THEN EXTENDS SWWD FROM
THIS SURFACE LOW INTO CENTRAL KS. THUNDERSTORMS ARE EXPECTED TO
DEVELOP AND INCREASE IN COVERAGE FROM SE NEBRASKA INTO NW MO TO
THE NORTH OF THE WARM FRONT...WHILE ALSO DEVELOPING ALONG THE
ADVANCING COLD FRONT. THE SURFACE LOW AND COLD FRONT ARE THEN
FORECAST TO TRACK EASTWARD TONIGHT AND FRIDAY WITH A THREAT OF
SHOWERS AND THUNDERSTORMS IN ADVANCE OF IT. FOR KUIN AND KCOU THIS
THREAT WILL BE OVERNIGHT TONIGHT TO JUST PAST DAWN ON FRIDAY...AND
HAVE KEPT WITH VCTS AND CB CLOUD GROUPS FOR NOW. ANY THREAT IN THE
ST LOUIS AREA SHOULD BE FROM MID MORNING THROUGH EARLY AFTERNOON
ALONG AND AHEAD OF THE ADVANCING COLD FRONT.
SPECIFICS FOR KSTL...
A PRETTY QUIET NIGHT LOOKS ON TAP WITH VFR CONDITIONS AND MOSTLY
CLEAR SKIES DOMINATING THIS EVENING AND THEN INCREASING HIGH
CLOUDS LATER TONIGHT.
SHOWERS FROM EARLIER TODAY HAVE PUSHED TO THE EAST WITH CLEAR OR
CLEARING SKIES IN THE WAKE. A WARM FRONT TO THE SOUTH WILL MOVE
NORTHWARD THROUGH THE TERMINAL NEAR OR JUST AFTER MIDNIGHT WITH
THE WIND VEERING TO THE SOUTH. ANY THREAT OF SHOWERS AND
THUNDERSTORMS IN THE ST LOUIS AREA SHOULD BE FROM MID MORNING
FRIDAY THROUGH EARLY AFTERNOON ALONG AND AHEAD OF THE ADVANCING
COLD FRONT. CONFIDENCE IS TOO LOW TO INCLUDE THIS FAR OUT IN THE
FORECAST AND FOR NOW HAVE JUST MENTIONED VCSH AND A CB CLOUD GROUP.
GLASS
&&
.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
321 PM CDT WED MAR 28 2012
.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 1226 PM CDT WED MAR 28 2012
FRONT BISECTS THE CWA WITH ALL TERMINALS TO THE NORTH OF THIS
FEATURE WITH CLEAR SKIES AND LIGHT NORTHERLY WINDS. FRONT IS
ATTEMPTING TO BUCKLE BACK NORTH ACROSS WESTERN MISSOURI AND THIS
IS WHERE CONVECTIVE INITIATION WILL TAKE PLACE THIS EVENING. AT
THIS TIME IT APPEARS THAT AN MCS WILL DEVELOP NEAR KANSAS CITY AND
MOVE EAST/SOUTHEAST INTO CENTRAL MISSOURI AND THE OZARKS
OVERNIGHT. HAVE MAINTAINED A PERIOD OF SHOWERS AT KCOU...WITH JUST AN
INCREASE OF HIGH/MID LEVEL CLOUDS ELSEWHERE.
SPECIFICS FOR KSTL...
VFR CONDITIONS EXPECTED AS FRONT HAS DRIFTED SOUTH OF THE
TERMINAL. LIGHT NORTH WIND WILL CONTINUE WITH ONLY AN INCREASE IN
HIGH/MID LEVEL CLOUDS FROM CONVECTION THAT WILL REMAIN WEST OF THE
TERMINAL THROUGH AT LEAST 12Z.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
929 AM CDT WED MAR 28 2012
.UPDATE...
ISSUED AT 915 AM CDT WED MAR 28 2012
WEAK COLD FRONT/WIND SHIFT IS STALLING AND CURRENTLY STRETCHES
FROM KDMO-KUUV-KBLV-KSLO. THIS WAS A TAD FURTHER NORTH THAN
GRIDDED DATABASE REFLECTED SO HAVE ADJUSTED FORECAST A BIT TO
ACCOUNT FOR THIS LOCATION. EXPECT TEMPERATURES WILL BE QUITE WARM
ALONG AND SOUTH OF THIS FRONT WITH FAVORABLE WESTERLY WIND AND
DEEP MIXING. HAVE MAINTAINED SLIGHT CHANCE POPS FOR THUNDERSTORMS
THIS AFTERNOON ALONG AND SOUTH OF THE BOUNDARY...BUT BELIEVE BEST
CHANCES WILL REMAIN TO OUR WEST WHERE HRRR IS SHOWING CONVECTIVE
INITIATION FROM ST. JOSEPH TO KANSAS CITY BY 00Z.
CVKING
&&
.SHORT TERM...
ISSUED AT 349 AM CDT WED MAR 28 2012
(TODAY-TONIGHT)
FOCUS THRU THE PERIOD WILL BE TEMPS TODAY AND POPS TONIGHT.
CDFNT CONTINUES TO MOVE S...JUST ENTERING THE NRN PORTIONS OF THE
CWA AS OF 08Z. HAVE KEPT SLIGHT CHANCE POPS GOING FOR A COUPLE OF
HRS AFTER SUNRISE TO ACCOUNT FOR ANY SURPRISE TSRA. IF ANYTHING DOES
FORM...COVERAGE SHUD BE ISOD. EVEN WITH THE CDFNT PUSHING THRU MUCH
OF THE CWA...EXPECT DEEP MIXING TO OCCUR BEHIND THE FNT WITH TEMPS
REACHING THE UPPER 70S TO LOWER 80S. WITH MIXING EXPECTED TO REACH
NEARLY 800MB...HAVE TRENDED ABOVE MOS FOR TODAY.
THE FNT SHUD STALL ACROSS THE SRN HALF OF THE CWA...THO THERE IS
SOME UNCERTAINTY JUST HOW FAR S IT WILL REACH BEFORE STALLING. WITH
INCREASED SFC CONVERGENCE AND SOME FORCING THRU THE LOWER
LEVELS...EXPECT TSRA TO DEVELOP ALONG THE FNT THIS AFTERNOON. WITH
THESE BEING DIURNALLY DRIVEN...SHUD DISSIPATE DURING THE EVENING AS
FORCING BEGINS TO REFOCUS FURTHER W ACROSS KS. THIS SHUD BE THE
GENESIS REGION FOR AN MCS.
EXPECT TSRA TO DEVELOP THIS AFTERNOON ACROSS THE ERN HALF OF KS JUST
AHEAD OF A WEAK SFC WAVE. MDLS DIFFER WHERE THIS WILL OCCUR WHICH
WILL HAVE DRAMATIC IMPACTS ON THE FCST FOR TONIGHT. BELIEVE MCS
ACTIVITY WILL TRACK SE ALONG THE FNT AND SHUD REMAIN W OF THE CWA.
IN THE WAKE OF THIS COMPLEX...EXPECT H85 FLOW TO BECOME MORE WLY AND
INTERSECT THE H85 FNT ALLOWING A SECOND ROUND OF TSRA TO FORM. THESE
TSRA ARE EXPECTED TO REACH CNTL MO AROUND/JUST BEFORE SUNRISE THURS.
SOME UNCERTAINTY IF THESE TSRA WILL HAVE SEVERE POTENTIAL AS MDLS
DEPICT SOMEWHAT MEAGER MID LEVEL LAPSE RATES.
TILLY
&&
.LONG TERM...
ISSUED AT 409 AM CDT WED MAR 28 2012
(THURSDAY-TUESDAY)
BEGINNING OF PERIOD WILL DEPEND UPON WHAT OCCURS OVERNIGHT AS
DISCUSSED ABOVE. MDLS STILL DIFFER REGARDING WHERE PRECIP WILL BE
ONGOING AT THE BEGINNING OF THE PERIOD. OVERALL...BELIEVE PRECIP
SHUD DIMINISH DURING THE MORNING AND REFOCUS FURTHER W AHEAD OF A
DEVELOPING SFC LOW ASSOC WITH A DEEPER UPPER TROF. MAIN QUESTION
WILL BE HOW FAR E THE ELEVATED TSRA GET DURING THE MORNING BEFORE
DISSIPATING. KEPT POPS FOR THURS AFTERNOON ALONG THE SFC FNT DURING
THE AFTERNOON WHERE SFC CONVERGENCE SHUD HELP INITIATE TSRA.
INCREASED POPS FOR THURS NIGHT AS THE SYSTEM PUSHES THRU THE
REGION...BUT KEPT LINGERING POPS INTO FRI TO ACCOUNT FOR TIMING
DIFFERENCES IN MDLS. THIS SYSTEM SHUD BRING SOMEWHAT COOLER TEMPS
FOR FRI AND SAT...THO STILL WELL ABOVE SEASONAL AVG.
FOR THE EXTD...MAIN FOCUS WILL BE TEMPS AS NOT MUCH EXPECTED IN THE
WAY OF PRECIP CHANCES.
WITH RETURN FLOW STARTING ALREADY BY SAT MORNING...TEMPS SHUD
REBOUND QUICKLY. STARTED A WARMER TREND SAT AND SUN...THO DID NOT GO
AS WARM AS THE MEX MOS WUD SUGGEST WITH NEAR RECORD TEMPS FOR CNTL
MO ON SAT AND THE ENTIRE CWA FOR SUN.
MDLS HAVE SPED UP TIMING OF FROPA ON SUN NIGHT INTO MON WITH THE GFS
AS A FAST OUTLIER. HAVE THEREFORE TRENDED TWD THE SLOWER ECMWF/GEM.
KEPT LOW POPS FOR FROPA. THE GEM/GFS DO SUGGEST SOME PRECIP WILL BE
POSSIBLE...THO TIMING DIFFERS.
BEHIND THIS SYSTEM...MDLS ARE IN FAIRLY GOOD AGREEMENT SUGGESTING
MUCH COOLER TEMPS WITH HIGHS ON ON TUES ONLY A FEW DEGREES ABOVE
AVG.
TILLY
&&
.AVIATION...
ISSUED AT 635 AM CDT WED MAR 28 2012
COLD FRONT APPROACHING COU-DEC LINE ATTM...WITH RADAR IMAGERY ONLY
INDICATING SPORATIC FEEBLE ATTEMPTS AT PRECIP DEVELOPMENT IN
MODEST POCKET OF RESDIUAL INSTABILITY AHEAD OF THE BOUNDARY. WITH
FRONT PUSHING S OF THE STL AREA OVER THE NEXT FEW HOURS...ANY
REDEVELOPMENT THAT OCCURS NEAR THE BOUNDARY LATER THIS MORNING OR
THIS AFTERNOON WILL BE S OF ALL TAF LOCATIONS. AMS N OF THE FRONT
IS QUITE DRY...SO EXPECTING LITTLE IF ANY CLOUDINESS TODAY.
THUNDERSTORMS SHOULD REDEVELOP OVER E KS AND W MO TONIGHT AS WARM
ADVECTION INTERACTS WITH STALLED BOUNDARY. GETTING THE IMPRESSION
THERE COULD BE TWO WAVES OF STORMS...THE FIRST THAT FORMS LATER
THIS AFTERNOON/EARLY THIS EVENING THAT WILL TRACK NEAR THE
SURFACE FRONT ACROSS S MO...AND THEN A MORE ELEVATED BATCH OF
STORMS THAT WOULD IMPACT COU DURING THE PREDAWN HOURS.
SPECIFICS FOR KSTL...
FRONTAL PASSAGE WILL OCCUR IN THE NEXT FEW HOURS. ONCE WIND SHIFT
OCCURS...EXPECT A GRADUAL VEERING OF THE WIND TO A NE DIRECTION BY
EARLY EVENING WITH SPEEDS AOB 8KTS. OUTSIDE OF A FEW SCATTERED MID
CLOUDS OVER THE NEXT FEW HOURS...LITTLE IF ANY CLOUDINESS EXPECTED
TODAY. ELEVATED STORMS MENTIONED IN GENERAL DISCUSSION SHOULD
REMAIN WELL WEST OF STL THROUGH THURSDAY MORNING.
TRUETT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS GLASGOW MT
303 PM MDT WED MAR 28 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH FRIDAY...
AN OPEN SHORTWAVE TROUGH AND COLD FRONT MOVES OVER WESTERN AND
CENTRAL MONTANA TODAY. THUNDERSTORMS ARE EXPECTED WITH THE
FRONT. THIS EVENING THE FRONT SPREADS ACROSS NORTHEAST
MONTANA...LOSING SOME OF ITS PUNCH. A FEW THUNDERSTORMS MIGHT MAKE
IT INTO OUR WESTERN ZONES...BUT CAPE THAT IS APPARENT TO OUR WEST
DISSIPATES BY 00Z. BOTH THE RUC AND GFS BRING SCATTERED RAIN
SHOWERS WITH THIS FRONT THIS EVENING...MAINLY OVER PHILLIPS AND
VALLEY COUNTIES. KEPT ISOLATED POPS IN ACROSS THE AREA AFTER
MIDNIGHT. A LEE SURFACE TROUGH SHIFTING EAST ACROSS THE AREA THE
MOSTLY SOUTHEASTERLY WINDS WILL SHIFT TO THE NORTHWEST.
AFTER PASSAGE OF THE TROUGH...FLOW ALOFT BECOMES MOSTLY ZONAL
WHILE SURFACE WINDS BECOME SOUTHWESTERLY THROUGH FRIDAY...WHICH
WILL TREND TEMPERATURES UPWARD.
THICKNESS HEIGHTS BEGIN THURSDAY MORNING AROUND 540DM...THEN
INCREASE TO OVER 550DM BY EVENING. SO EXPECT MAXIMUM TEMPERATURES
TO WARM TO AROUND 15F DEGREES ABOVE NORMAL. WEAK UPPER RIDGING
WILL WILL BRING MOSTLY SUNNY SKIES FOR A MILD DAY.
THICKNESS HEIGHTS INCREASE TO AROUND 560DM ON FRIDAY SO HIGHS COULD
REACH AROUND 25F DEGREES ABOVE NORMAL. HOWEVER A SIGNIFICANT
AMOUNT OF PACIFIC MOISTURE MOVES INTO THE NORTHERN ROCKIES AND
DISTURBANCES IN THE FLOW ALOFT WILL INCREASE CLOUD COVER...WHICH
COULD INITIATE A FEW SHOWERS IN THE AFTERNOON. WHILE MET AND MAV
GUIDANCE SUGGEST WARM TEMPERATURES...OVERCAST SKY COVER COULD
LIMIT MAXIMUM TEMPERATURES LOWER THAN GUIDANCE. SCT
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...
THE BULK OF CHANGES WERE MADE IN REGARDS TO THE LATE WEEKEND
SYSTEM. MODELS CONTINUE TO STRUGGLE WITH THE DETAILS OF THE
LOW PRESSURE SYSTEM FOR SATURDAY NIGHT INTO SUNDAY NIGHT. BUT
GIVEN ANY SOLUTION A PATTERN CHANGE IS IN STORE FOR NORTHEAST
MONTANA...WITH COOLER MORE NORMAL TEMPERATURES LINGERING INTO
EARLY NEXT WEEK. THUS CONSERVATIVELY TRENDED UP POPS FOR THE
SATURDAY NIGHT INTO SUNDAY NIGHT TIME-FRAME. ALSO TRENDED UP WINDS
AS SUNDAY INTO MONDAY LOOKS WINDY AS THE SURFACE LOW MOVES
THROUGH. OTHERWISE ANY OTHER TWEAKS WERE MINOR AS UPPER RIDGING
BUILDS IN NEXT WEEK. GILCHRIST
PREVIOUS LONG TERM DISCUSSION...A MODERATELY STRONG LOW PRESSURE
SYSTEM FROM THE W ARRIVES THIS WEEKEND...WHICH MODELS AGREE WITH
AND ALL PRODUCE SIGNIFICANT PRECIP OVER PARTS OF NE MT.
DIFFERENCES THOUGH ON LOCATION IN NE MT...AS MOST...BUT NOT
ALL...RECENT MODELS KEEP THE STRONGER PART OF THE SYSTEM OVER
CANADA. ALSO WITH POOR MODEL HANDLING OF PAST FEW SYSTEMS AND THE
DRY PATTERN OF LATE...WILL GO SOMEWHAT CONSERVATIVE WITH POPS. 2
PERIODS OF CHANCE POPS LOOK PLENTY ADEQUATE.
THE AIR-MASS WITH THIS SYSTEM WILL BE UNSTABLE ENOUGH FOR SHOWERY
PRECIP...AND POSSIBLY AN ISOLATED THUNDERSTORM...ALTHOUGH MODELS
TEND OVERLY UNSTABLE IN EARLY SPRING. STRONG COLD ADVECTION
FOLLOWS...BUT THEY VARY QUITE A BIT TOO ON WHETHER THERE WILL BE
ENOUGH COLD ADVECTION FOR SOME PRECIP TO END AS SNOW LATE SAT
NIGHT. ADDED SNOW SHOWER MENTION TO ONLY N VALLEY AND SW PHILLIPS
ZONES. A VERY WINDY DAY SUNDAY THOUGH AS 850 WINDS OF 35 TO 50
KT LIKELY TO MIX TO THE SURFACE.
FOR THE REST OF THE FORECAST PERIOD...POOR MODEL AGREEMENT. MOST
MODELS FAVOR RIDGING WITH DRY WEATHER AND MODEST WARMING. LATEST
GFS WAS AN OUTLIER WITH OTHER MODELS THOUGH AND LOOKS THAT WAY ON
ITS ENSEMBLES AS IT BREAKS THE RIDGE DOWN VERY QUICK TUE/WED.
SIMONSEN
&&
.AVIATION...
VFR CONDITIONS WILL LARGELY DOMINATE AT ALL THE TERMINALS OVER THE
NEXT 24 HOURS. A WEAK FRONTAL PASSAGE THIS EVENING WILL BRING A
FEW SHOWERS...BUT CEILINGS AND OR VISIBILITY IS EXPECTED TO REMAIN
VFR. GUSTY SOUTHEAST WINDS WILL CONTINUE THROUGH EARLY
EVENING...WHEN THEY WILL DECREASE TO AROUND 10KTS. A WIND SHIFT
WILL OCCUR WITH THE SURFACE FRONT AFTER MIDNIGHT FROM SOUTHEAST TO
NORTHWEST. NORTHWEST WINDS WILL CONTINUE INTO THURSDAY
MORNING...AND SKIES WILL GRADUALLY CLEAR BY MIDDAY THURSDAY.
GILCHRIST
&&
.FIRE WEATHER...
WILL CONTINUE TO WATCH THE SOUTHERN HALF OF THE FORECAST AREA THIS
AFTERNOON. METEOROLOGICAL CONDITIONS REMAIN MARGINAL FOR
CRITICAL FIRE WEATHER CONDITIONS...BASED ON RELATIVE HUMIDITIES IN
THE LOWER 20S AND WINDS OF 15-20 MPH. FIRE WEATHER CONDITIONS
COULD BECOME CRITICAL ON FRIDAY AFTERNOON...ALSO BASED ON EXPECTED
WARM TEMPERATURES...RESULTING IN LOW RELATIVE HUMIDITIES...ALONG
WITH SOUTHWEST WINDS OF AROUND 20MPH. SCT
&&
.CLIMATE...
THE FIRST 27 DAYS OF MARCH ARE THE WARMEST ON RECORD IN GLASGOW.
THE AVERAGE TEMPERATURE OF 40.7 DEGREES IS 10.0 DEGREES ABOVE
NORMAL. WE HAVE A GOOD CHANCE OF SETTING THE ALL-TIME RECORD FOR
THE ENTIRE MONTH OF MARCH...WHICH WAS MARCH 1986. MARCH WILL MAKE
FOR THE 9TH STRAIGHT MONTH THAT HAS BEEN WARMER THAN NORMAL.
THE 26 DAY PERIOD FROM THE 2ND TO THE 27TH...ONLY 0.07 INCH OF
PRECIP FELL...WHICH IS TIED FOR 10TH DRIEST. DUE TO 0.33 ON THE
FIRST...MARCH AS A WHOLE WILL NOT RANK AS UNUSUALLY DRY. SIMONSEN
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 6 PM MDT THIS EVENING FOR FORT PECK
LAKE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
613 PM CDT THU MAR 29 2012
.AVIATION...00Z KGRI TAF. A LINE OF THUNDERSTORMS IS TRACKING EAST
TOWARDS KGRI AND IF IT HOLDS TOGETHER THE STORMS SHOULD ARRIVE
AROUND OR SHORTLY AFTER 7 PM. THE WEATHER WILL QUICKLY QUIET DOWN
AFTER THESE THUNDERSTORMS PASS...WHICH SHOULD BE BY 8 PM. LIGHT
WINDS WITH VFR CEILINGS WILL BE EXPECTED FOR THE REMAINDER OF THE
TAF VALID PERIOD. THE WIND WILL PRIMARILY BE NORTHWEST TONIGHT AND
THEN SOUTHWEST TOMORROW.
&&
.PREV DISCUSSION... /ISSUED 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.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
207 AM EDT WED MAR 28 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM MOVING THROUGH THE UPPER GREAT LAKES AND
SOUTHERN CANADA WILL SWING A WARM FRONT THROUGH THE REGION
WEDNESDAY MORNING...FOLLOWED BY A COLD FRONT IN THE AFTERNOON.
THESE FRONTS WILL BRING SOME RAIN SHOWERS AND POSSIBLE THUNDER TO
THE AREA WEDNESDAY. SCATTERED RAIN OR SNOW SHOWERS WILL BE
POSSIBLE ACROSS CENTRAL NEW YORK ON WEDNESDAY NIGHT...WITH SLOWLY
IMPROVING CONDITIONS EXPECTED ON THURSDAY. HIGH PRESSURE WILL
BUILD IN WITH FAIR SKIES ON THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TODAY/...
.1250 AM UPDATE...
QUICK UPDATED DESPERATELY NEEDED TO ACCOUNT FOR RISING TEMPS
ACROSS THE WESTERN CWA AS REGION BECOMES ENVELOPED IN A WELL-
ESTABLISHED WARM AIR ADVECTION REGIME. UNFORTUNATELY THERE IS NO
MODEL GUIDANCE THAT SEEMS TO BE HANDLING THIS NON-DIURNAL TEMP TREND
WELL SO QUITE A BIT OF MANUAL GRID MANIPULATION WAS NEEDED. IN ANY
EVENT FURTHER TO OUR WEST...ANOTHER WARM FRONT IS DRAPED ACROSS
THE UPPER OHIO VLY WHICH WILL BE APPROACHING THE AREA AFTER
SUNRISE. MODELS CONTINUE TO SUGGEST SHWRS AND POSSIBLY EVEN AN
ELEVATED THUNDERSTORM OR TWO ACCOMPANYING ITS PASSAGE AS ELEVATED
CAPE VALUES QUICKLY APPROACH 500 J/KG ACROSS A GOOD CHUNK OF THE
CWA. THIS WILL BE THE FIRST OF TWO ROUNDS OF RAIN/POSSIBLE THUNDER
AS THE OCCLUDED TRIPLE POINT PASSES THROUGH THE AREA DURING THE
AFTERNOON. WILL TACKLE THOSE DETAILS MORE THOROUGHLY WITH NEXT
UPDATE.
.PREVIOUS NEAR TERM UPDATES...
1030 PM UPDATE...FORECAST UPDATED TO INCREASE POPS
WEDNESDAY MORNING...AND EVEN INCLUDE MENTION OF THUNDER. WE REMAIN
VERY DRY AT THE LOW LEVELS...BUT THE STRENGTH OF THE WARM AIR
ADVECTION WITH THE INCOMING SYSTEM MUST BE RESPECTED. IN
FACT...DESPITE 35 DEGREE DEW POINT DEPRESSION FROM AN OBS SITE ON
BRUCE PENINSULA AT THE SURFACE...ALOFT THERE IS ENOUGH MOISTURE
AND EVEN INSTABILITY FOR A CLUSTER OF THUNDERSTORMS THAT HAS
MANAGED TO DEVELOP. SURFACE-BASED LIFTED INDICES IN OUR SOUNDINGS
12Z-15Z OF COURSE ARE VERY POSITIVE. BUT A CLOSER LOOK AT THE
LATEST SOUNDINGS REVEAL THAT ABOVE THE VERY STABLE NEAR SURFACE
LAYER...THERE IS ACTUALLY A FAIR AMOUNT OF INSTABILITY. KELM NAM
SOUNDING SEEN VIA BUFKIT FOR EXAMPLE MANAGES A FEW HUNDRED J/KG
ELEVATED CAPE...AND PRECIPITABLE WATER CLIMBS ABOVE AN INCH. THE
RAPID UPDATE HIGH RESOLUTION MODELS SUCH AS THE HRRR AND ARW ARE
ALSO CATCHING ON TO THIS QUICKLY EVOLVING TREND...THAT SHOWERS AND
EVEN THUNDER ARE BECOMING MORE PROBABLE IN THE MORNING. BRIEF WARM
SECTOR THEN COMES IN BEHIND THE MORNING BATCH...ONLY FOR COLD
FRONT TO THEN PASS THROUGH THE AREA FOR ADDITIONAL CHANCE OF
SHOWERS AND THUNDER. WELL UPSTREAM...THUNDERSTORMS IN ILLINOIS ARE
GIVING US A HINT OF THIS POTENTIAL.
AS CAN BE EXPECTED WITH THE RADIATIONAL COOLING SITUATION UP TO
NOW THIS EVENING...TEMPERATURES HAVE NEEDED TWEAKING TO KEEP UP
WITH CURRENT CONDITIONS AND TRENDS. THICKENING HIGH CLOUDS AND
INCREASING WARM AIR ADVECTION WILL ALLOW LOWS TO OCCUR BY AROUND
MIDNIGHT OR SO...WITH HIGH CLOUDS AND WARM AIR ADVECTION HELPING
TEMPERATURES TURN THE CORNER TO RISE FOR THE REMAINDER OF THE
NIGHT. IF SHOWERS MOVE IN FAST ENOUGH...A COUPLE PLACES IN MOHAWK
VALLEY...PARTICULARLY NORTHERN ONEIDA COUNTY COULD A LIGHT
FREEZING RAIN THAT QUICKLY SWITCHES OVER TO PLAIN RAIN.
HOWEVER...THIS IS NOT CONSIDERED VERY LIKELY AT THIS TIME...WITH
MORE PROBABLE OUTCOME BEING TEMPERATURES BREAKING ABOVE FREEZING
BEFORE OR JUST AS SHOWERS ARRIVE.
BIG GRADIENT IN TEMPERATURES WEDNESDAY...WITH SURGE OF WARM AIR
CAPTURING MOST OF THE AREA...YET TRIPLE POINT PASSING CLOSE TO THE
NORTHEASTERN ZONES AND ALSO STABLE LOW LEVEL AIR BEING PERHAPS A
BIT HARDER TO SCOUR OUT. PARTIAL SUNSHINE BETWEEN BATCHES OF
SHOWERS/THUNDER...WILL ALLOW TEMPERATURES IN WARM SECTOR FOR MOST
OF THE AREA TO CLIMB INTO THE UPPER 50S TO MID 60S...YET CLOSER TO
50 IN THE MOHAWK VALLEY NORTHWARD.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
2NDRY SURGE OF COOLER AIR WORKS SOUTH ON WED NGT...AS S/WV
MOVS BY TO THE N. MDLS SHOW MOIST NW FLOW...SO CHC POPS FOR
-SHRA/-SHSN OVRNGT. SLOW IMPROVEMENT ON THU AS HIGH PRES TRIES TO
BUILD IN BUT GUSTY NW WINDS SHUD PERSIST DURING THE DAY. WENT
BELOW MOS GUIDANCE ON THU AS MOS MAXES WERE NOT SUPPORTED BY MDL
925 MB TEMPS...WHICH INFERRED MAXES THE L/M 40S. MAINLY SKC ON
THU NGT AS SFC RDG AXIS MOVS INTO THE AREA. ON FRI LEANED TWDS THE
12Z GFS/00Z EURO...AND ONLY MENTIONED A SLGT CHC OF -SHRA ACRS FAR
SW SXNS OF THE CWA LATE IN THE DAY. OTRW...IT APPEARS THAT THERE WILL
BE PLENTY OF MID AND HI CLD SPREADING ACRS CNTRL AND SRN SXNS ON
FRI.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
440 PM UPDATE...LONG TERM PATTERN IS SOMEWHAT BUSY WITH QUICK
SUCCESSION OF MID SCALE UPPER RIDGES AND WAVES. YET BECAUSE THESE
UPPER FEATURES ARE NOT VERY BIG...THE FORECAST IS PRONE TO MODEL-
TO-MODEL AND RUN-TO-RUN INCONSISTENCIES ON TIMING FOR EACH OF
THEM. ALSO...WITH THE QUICK TIMING BETWEEN FEATURES...MOISTURE
AVAILABILITY COULD BE AND ISSUE. THUS I DID NOT STRAY MUCH FROM
HPC GUIDANCE...WHICH ITSELF WAS FAIRLY NON-COMMITTAL WITH SLIGHT
TO LOW CHANCE POPS. ON A LARGER SCALE THOUGH...GFS/ECMWF AT LEAST
HAVE COME INTO AGREEMENT ON NEAR NORMAL 500MB HEIGHTS EARLY IN THE
WEEKEND...TRANSITIONING TO BRIEF PERIOD OF ABOVE NORMAL HEADING
INTO MONDAY/TUESDAY. OUR FORECAST THUS ALSO TRENDS FROM NEAR
NORMAL EARLY IN THE PERIOD...TO ROUGHLY 10 DEGREES ABOVE
CLIMATOLOGY BY MONDAY/TUESDAY.
ONE OTHER NOTE...NEW 12Z ECMWF HAS A COASTAL SURFACE LOW MOVING
UP FROM THE MID-ATLANTIC TO OFFSHORE THE NORTHEAST...WITH THE BACK
PART OF ITS PRECIPITATION SHIELD ALONG WITH A MORE AMPLIFIED UPPER
WAVE OVER OUR REGION ON SUNDAY. THIS IS A SIGNIFICANT DEPARTURE
FROM THE 00Z ECMWF...AND IS STARKLY DIFFERENT FROM THE 12Z
GFS...SO NOT PUTTING TOO MUCH STOCK INTO THAT SCENARIO AT THIS
TIME.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
06Z UPDATE... VFR SHOULD PREVAIL THE MAJORITY OF THE TAF PD. THE
BEST CHC FOR RESTRICTIVE CONDS WILL COME LTR TNT (STARTING IN THE
04-06Z THU TIME FRAME)...WHEN LWR CIGS/-SHRA SHOULD
DEVELOP...INITIALLY ACRS THE CNY TERMINALS.
IN THE NEAR-TERM (THROUGH ABT 12Z)...THE PRIMARY ISSUE WILL BE
LLWS...AS A SHARP SFC-BASED INVERSION EXISTS...WITH MUCH STGR
WINDS JUST OFF THE DECK (AOA 1500-2000 FEET AGL).
SCTD -SHRA SHOULD MOVE ACRS THE NRN TERMINALS (KSYR/KRME/KITH) IN
THE 12-15Z TIME FRAME...BUT UNRESTRICTED CIGS/VSBYS ARE
ANTICIPATED WITH THIS ACTIVITY. THEN...THIS AFTN...ANOTHER ROUND
OF ISOLD/SCTD -SHRA ARE EXPECTED. AGAIN...THOUGH...UNRESTRICTED
CONDS ARE GENERALLY FORESEEN...AND COVERAGE IS EVEN A BIT MORE
QUESTIONABLE...SO WE`VE LEFT OUT OF THE FORECAST AT THIS JUNCTURE.
SFC WINDS SHOULD TURN SW AND BECOME FAIRLY GUSTY IN THE LATE
MRNG/EARLY AFTN PD. BEHIND THE COLD FRNT LATER IN THE DAY AND THIS
EVE...GUSTY NW WINDS ARE EXPECTED (UP TO 25-30 KT).
.OUTLOOK...
THU MRNG...CHC MVFR IN -SHRA...MIXED WITH -SHSN AT TIMES...SPCLY
KBGM/KITH.
THU AFTN TO FRI...MAINLY VFR.
FRI NGT INTO SAT...CHC OF RESTRICTIONS IN LWR CIGS/-RA...PSBLY
MIXED WITH -SN ON THE HILLS AT KBGM/KITH BY EARLY SAT.
SAT AFTN AND NGT...MAINLY VFR.
SUN...CHC MVFR IN -SHRA.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...CMG/MDP
SHORT TERM...
LONG TERM...MDP
AVIATION...MLJ/TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
100 AM EDT WED MAR 28 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM MOVING THROUGH THE UPPER GREAT LAKES AND
SOUTHERN CANADA WILL SWING A WARM FRONT THROUGH THE REGION
WEDNESDAY MORNING...FOLLOWED BY A COLD FRONT IN THE AFTERNOON.
THESE FRONTS WILL BRING SOME RAIN SHOWERS AND POSSIBLE THUNDER TO
THE AREA WEDNESDAY. SCATTERED RAIN OR SNOW SHOWERS WILL BE
POSSIBLE ACROSS CENTRAL NEW YORK ON WEDNESDAY NIGHT...WITH SLOWLY
IMPROVING CONDITIONS EXPECTED ON THURSDAY. HIGH PRESSURE WILL
BUILD IN WITH FAIR SKIES ON THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TODAY/...
.1250 AM UPDATE...
QUICK UPDATED DESPERATELY NEEDED TO ACCOUNT FOR RISING TEMPS
ACROSS THE WESTERN CWA AS REGION BECOMES ENVELOPED IN A WELL-
ESTABLISHED WARM AIR ADVECTION REGIME. UNFORTUNATELY THERE IS NO
MODEL GUIDANCE THAT SEEMS TO BE HANDLING THIS NON-DIURNAL TEMP TREND
WELL SO QUITE A BIT OF MANUAL GRID MANIPULATION WAS NEEDED. IN ANY
EVENT FURTHER TO OUR WEST...ANOTHER WARM FRONT IS DRAPED ACROSS
THE UPPER OHIO VLY WHICH WILL BE APPROACHING THE AREA AFTER
SUNRISE. MODELS CONTINUE TO SUGGEST SHWRS AND POSSIBLY EVEN AN
ELEVATED THUNDERSTORM OR TWO ACCOMPANYING ITS PASSAGE AS ELEVATED
CAPE VALUES QUICKLY APPROACH 500 J/KG ACROSS A GOOD CHUNK OF THE
CWA. THIS WILL BE THE FIRST OF TWO ROUNDS OF RAIN/POSSIBLE THUNDER
AS THE OCCLUDED TRIPLE POINT PASSES THROUGH THE AREA DURING THE
AFTERNOON. WILL TACKLE THOSE DETAILS MORE THOROUGHLY WITH NEXT
UPDATE.
.PREVIOUS NEAR TERM UPDATES...
1030 PM UPDATE...FORECAST UPDATED TO INCREASE POPS
WEDNESDAY MORNING...AND EVEN INCLUDE MENTION OF THUNDER. WE REMAIN
VERY DRY AT THE LOW LEVELS...BUT THE STRENGTH OF THE WARM AIR
ADVECTION WITH THE INCOMING SYSTEM MUST BE RESPECTED. IN
FACT...DESPITE 35 DEGREE DEWPOINT DEPRESSION FROM AN OBS SITE ON
BRUCE PENINSULA AT THE SURFACE...ALOFT THERE IS ENOUGH MOISTURE
AND EVEN INSTABILITY FOR A CLUSTER OF THUNDERSTORMS THAT HAS
MANAGED TO DEVELOP. SURFACE-BASED LIFTED INDICES IN OUR SOUNDINGS
12Z-15Z OF COURSE ARE VERY POSITIVE. BUT A CLOSER LOOK AT THE
LATEST SOUNDINGS REVEAL THAT ABOVE THE VERY STABLE NEAR SURFACE
LAYER...THERE IS ACTUALLY A FAIR AMOUNT OF INSTABILITY. KELM NAM
SOUNDING SEEN VIA BUFKIT FOR EXAMPLE MANAGES A FEW HUNDRED J/KG
ELEVATED CAPE...AND PRECIPITABLE WATER CLIMBS ABOVE AN INCH. THE
RAPID UPDATE HIGH RESOLUTION MODELS SUCH AS THE HRRR AND ARW ARE
ALSO CATCHING ON TO THIS QUICKLY EVOLVING TREND...THAT SHOWERS AND
EVEN THUNDER ARE BECOMING MORE PROBABLE IN THE MORNING. BRIEF WARM
SECTOR THEN COMES IN BEHIND THE MORNING BATCH...ONLY FOR COLD
FRONT TO THEN PASS THROUGH THE AREA FOR ADDITIONAL CHANCE OF
SHOWERS AND THUNDER. WELL UPSTREAM...THUNDERSTORMS IN ILLINOIS ARE
GIVING US A HINT OF THIS POTENTIAL.
AS CAN BE EXPECTED WITH THE RADIATIONAL COOLING SITUATION UP TO
NOW THIS EVENING...TEMPERATURES HAVE NEEDED TWEAKING TO KEEP UP
WITH CURRENT CONDITIONS AND TRENDS. THICKENING HIGH CLOUDS AND
INCREASING WARM AIR ADVECTION WILL ALLOW LOWS TO OCCUR BY AROUND
MIDNIGHT OR SO...WITH HIGH CLOUDS AND WARM AIR ADVECTION HELPING
TEMPERATURES TURN THE CORNER TO RISE FOR THE REMAINDER OF THE
NIGHT. IF SHOWERS MOVE IN FAST ENOUGH...A COUPLE PLACES IN MOHAWK
VALLEY...PARTICULARLY NORTHERN ONEIDA COUNTY COULD A LIGHT
FREEZING RAIN THAT QUICKLY SWITCHES OVER TO PLAIN RAIN.
HOWEVER...THIS IS NOT CONSIDERED VERY LIKELY AT THIS TIME...WITH
MORE PROBABLE OUTCOMING BEING TEMPERATURES BREAKING ABOVE FREEZING
BEFORE OR JUST AS SHOWERS ARRIVE.
BIG GRADIENT IN TEMPERATURES WEDNESDAY...WITH SURGE OF WARM AIR
CAPTURING MOST OF THE AREA...YET TRIPLE POINT PASSING CLOSE TO THE
NORTHEASTERN ZONES AND ALSO STABLE LOW LEVEL AIR BEING PERHAPS A
BIT HARDER TO SCOUR OUT. PARTIAL SUNSHINE BETWEEN BATCHES OF
SHOWERS/THUNDER...WILL ALLOW TEMPERATURES IN WARM SECTOR FOR MOST
OF THE AREA TO CLIMB INTO THE UPPER 50S TO MID 60S...YET CLOSER TO
50 IN THE MOHAWK VALLEY NORTHWARD.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
2NDRY SURGE OF COOLER AIR WORKS SOUTH ON WED NGT...AS S/WV
MOVS BY TO THE N. MDLS SHOW MOIST NW FLOW...SO CHC POPS FOR
-SHRA/-SHSN OVRNGT. SLOW IMPROVMENT ON THU AS HIGH PRES TRIES TO
BUILD IN BUT GUSTY NW WINDS SHUD PERSIST DURING THE DAY. WENT
BELOW MOS GUIDANCE ON THU AS MOS MAXES WERE NOT SUPPORTED BY MDL
925 MB TEMPS...WHICH INFERRED MAXES THE L/M 40S. MAINLY SKC ON
THU NGT AS SFC RDG AXIS MOVS INTO THE AREA. ON FRI LEANED TWDS THE
12Z GFS/00Z EURO...AND ONLY MENTIONED A SLGT CHC OF -SHRA ACRS FAR
SW SXNS OF THE CWA LATE IN THE DAY. OTRW...IT APPEARS THAT THERE WILL
BE PLENTY OF MID AND HI CLD SPREADING ACRS CNTRL AND SRN SXNS ON
FRI.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
440 PM UPDATE...LONG TERM PATTERN IS SOMEWHAT BUSY WITH QUICK
SUCCESSION OF MID SCALE UPPER RIDGES AND WAVES. YET BECAUSE THESE
UPPER FEATURES ARE NOT VERY BIG...THE FORECAST IS PRONE TO MODEL-
TO-MODEL AND RUN-TO-RUN INCONSISTENCIES ON TIMING FOR EACH OF
THEM. ALSO...WITH THE QUICK TIMING BETWEEN FEATURES...MOISTURE
AVAILABILITY COULD BE AND ISSUE. THUS I DID NOT STRAY MUCH FROM
HPC GUIDANCE...WHICH ITSELF WAS FAIRLY NON-COMMITTAL WITH SLIGHT
TO LOW CHANCE POPS. ON A LARGER SCALE THOUGH...GFS/ECMWF AT LEAST
HAVE COME INTO AGREEMENT ON NEAR NORMAL 500MB HEIGHTS EARLY IN THE
WEEKEND...TRANSITIONING TO BRIEF PERIOD OF ABOVE NORMAL HEADING
INTO MONDAY/TUESDAY. OUR FORECAST THUS ALSO TRENDS FROM NEAR
NORMAL EARLY IN THE PERIOD...TO ROUGHLY 10 DEGREES ABOVE
CLIMATOLOGY BY MONDAY/TUESDAY.
ONE OTHER NOTE...NEW 12Z ECMWF HAS A COASTAL SURFACE LOW MOVING
UP FROM THE MIDATLANTIC TO OFFSHORE THE NORTHEAST...WITH THE BACK
PART OF ITS PRECIPITATION SHIELD ALONG WITH A MORE AMPLIFIED UPPER
WAVE OVER OUR REGION ON SUNDAY. THIS IS A SIGNIFICANT DEPARTURE
FROM THE 00Z ECMWF...AND IS STARKLY DIFFERENT FROM THE 12Z
GFS...SO NOT PUTTING TOO MUCH STOCK INTO THAT SCENARIO AT THIS
TIME.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
730 PM UPDATE...
IN GENERAL VFR CONDITIONS EXPECTED THROUGH TAF PERIOD.
SFC LOW PRES MOVING THROUGH THE UPPER GREAT LAKES INTO SOUTHERN
ONTARIO WILL BRING A WARM FRONT NEAR THE REGION LATE WED MORNING.
MID/HIGH LEVEL CLOUDS WILL INCREASE OVERNIGHT WITH CIGS DROPPING
TO 5K FT AROUND 11Z IN NY. SYSTEM LACKS MOISTURE AND IS MOVING
INTO A VERY DRY AIRMASS THEREFORE ONLY INCLUDED PROB30 FOR MVFR
RAIN SHOWERS AT KRME/KSYR BETWEEN 14Z TO 18Z. CIGS AT KRME COULD
FALL TO MVFR WITH ANY MIDDAY SHOWERS. FOR THE AFTN AT KRME/KSYR PUT
PREDOMINANT SHOWERS BUT CONFIDENCE NOT HIGH. NOT EXPECTING MVFR
WITH THE SHOWERS. A BETTER CHANCE FOR SHOWERS EARLY EVENING AFTER
00Z.
LIGHT AND VARIABLE WINDS BECOMING E/SE OVERNIGHT AT 5-10 KNOTS.
LOW LEVEL WINDS SHEAR IS LIKELY LATE TONIGHT DUE TO SHARP
INVERSION WITH STRONG SPEED/DIRECTIONAL SHEAR. WINDS AT 2K FT BY
06Z WILL BE 22035KT. SFC WINDS BECOMING S/SW AFTER SUNRISE AROUND
10 KNOTS. WINDS SHIFT TO WEST IN THE AFTN AT 12G20KTS.
.OUTLOOK...
WED NIGHT TO THU...CHC MVFR IN -SHRA...MIXED WITH -SHSN AT TIMES
LATE WEDNESDAY NIGHT AND THURSDAY MORNING.
THURSDAY AFTN TO FRIDAY NIGHT...VFR.
SAT...CHC MVFR IN -SHRA...MOSTLY FOR KAVP.
SAT NGT...VFR.
SUNDAY...CHC MVFR IN -SHRA.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...CMG/MDP
SHORT TERM...
LONG TERM...MDP
AVIATION...TAC
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1042 AM CDT WED MAR 28 2012
.DISCUSSION...
CHALLENGES TODAY ARE CLOUDS AND TEMPERATURES. 15 UTC SATELLITE
LOOP SHOWS LOW STRATUS DECK FROM SOUTHEAST SASKATCHEWAN TO WEST-
CENTRAL MN. CLOUDS ARE MORE OR LESS STATIONARY AND FLOW ALOFT
WEAKENS TODAY AS SURFACE RIDGE AXIS MOVES ACROSS THE FORECAST
AREA. RUC 925 HPA RH APPEARS TO HAVE BEST HANDLE ON CURRENT
CONDITIONS AND HINTS THAT CLOUDS WILL BE VERY SLOW TO DISSIPATE
THROUGH THE DAY. THERE ARE SOME BREAKS IN THE CLOUDS ACROSS
NORTHEAST ND AND NORTHWEST MN...BUT CONVECTIVE TEMPERATURES IN THE
MID 40S SUGGEST SOME AFTERNOON THERMAL CUMULUS. OVERALL...EXPECT
MOSTLY CLOUDY CONDITIONS WITH SOME SUN BY LATE THIS AFTERNOON...
ESPECIALLY ACROSS THE NORTHERN FORECAST AREA.
WITH BKN-OVC SKY COVER AND NEAR NEUTRAL LOW-LEVEL TEMPERATURE
ADVECTION...TEMPERATURES WILL STRUGGLE TO REACH PREVIOUS FORECAST
AFTERNOON HIGHS. DROPPED HIGHS 2 TO 3 DEGREES ACROSS THE SOUTH...
BUT THIS MAY NOT BE ENOUGH IF CLOUD COVER HOLDS STEADY. DID
INCREASE VALUES A DEGREE OR TWO ACROSS THE NORTH WHERE THERE IS
SOME SUN THIS MORNING. WILL GO WITH HIGHS IN THE MID 40S TO NEAR
50 DEGREES ACROSS THE SOUTHERN VALLEY...BUT WOULD NOT BE SURPRISED
IF SOME AREAS ONLY REACH THE LOW 40S.
&&
.AVIATION...
MVFR/IFR CEILINGS WILL BE SLOW TO ERODE TODAY AT ALL TAF SITES
GIVEN WEAK FLOW ALOFT AND SURFACE HIGH PRESSURE. LIGHT NORTH-NORTHEAST
WIND WILL GRADUALLY SHIFT TO THE EAST LATER THIS EVENING.
&&
.PREV DISCUSSION... /ISSUED 430 AM CDT WED MAR 28 2012/
SHORT TERM...TODAY THROUGH FRIDAY NIGHT.
PROGRESSIVE UPPER AIR PATTERN IS FORECAST FOR THE NORTHERN PLAINS.
NORTHWEST FLOW ALOFT WAS OVER THE AREA. UPPER LEVEL RIDGE OVER THE
NORTHERN ROCKIES WILL MOVE ACROSS THE AREA TONIGHT. THEREAFTER FLOW
ALOFT BECOMES ZONAL. WATER VAPOR LOOP INDICATED A PARADE OF SHORT
WAVES UPSTREAM. ONE SHORT WAS OVER THE AREA. WILL ADD LOW POPS OVER
NORTHEAST ZONES THIS MORNING.
INL OBSERVED SOUNDING INDICATED FAIRLY DEEP LOW LEVEL MOISTURE UP TO
775 HPA. EXPECT CLOUDS FOR MUCH OF THE DAY. CLEARING MOST LIKELY
OVER SOUTH AND WEST ZONES THIS AFTERNOON.
AN UNSETTLED PERIOD IS EXPECTED FOR THE NEXT 84 HOURS. LOW LEVEL JET
TO INCREASE LATER TONIGHT. WILL ADD LOW POPS AFTER MIDNIGHT. SHORT
WAVE OFF THE WEST COAST WILL MOVE THROUGH THU/THU NIGHT. POPS WERE
TWEAKED FOR THU AND THU NIGHT. NO CHANGE TO POPS FOR FRI IN THE
NORTH.
LONG TERM...[SATURDAY-TUESDAY]
ALL THE DETERMINISTIC MODELS HAVE A FAIRLY ACTIVE PATTERN FOR THE
PERIOD...BUT THERE ARE SOME SIGNIFICANT DIFFERENCES IN PLACEMENT AND
TIMING OF VARIOUS SHORTWAVES COMING THROUGH. TEMPERATURES CONTINUE
TO LOOK MILD THROUGH THE WEEKEND AS THE GFS...ECMWF...AND GEM ALL
HAVE 850MB TEMPS WELL INTO THE TEENS C. THE DIFFERENCES START WITH
THE TIMING OF THE NEXT SHORTWAVE COMING IN SUNDAY
NIGHT/MONDAY...WITH THE GFS MUCH MORE PROGRESSIVE WITH THE SYSTEM
THAN THE OTHER MODELS. THERE IS FAIRLY GOOD AGREEMENT ON SOME
COLDER TEMPS COMING DOWN FOR THE EARLY PART OF NEXT WEEK BEHIND THE
SHORTWAVE...BUT AS FAR AS PRECIP GOES TIMING OF ANYTHING IS VERY
MUCH UP IN THE AIR. THE GFS BRINGS ANOTHER SHORTWAVE INTO WESTERN
ND BY TUESDAY WHILE THE ECMWF KEEPS THE CWA UNDER NORTHWESTERLY
FLOW. ENSEMBLE SPREAD BECOMES VERY HIGH AS EARLY AS SUNDAYS
SYSTEM...SO CONFIDENCE IN ANY ONE SOLUTION IS VERY LOW.
THUS...CONTINUED TO KEEP THE BLENDED FORECAST...WITH SOME MINOR
TWEAKS TO AGREE A BIT BETTER WITH THE NEIGHBORS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
ROGERS/HOPPES
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
800 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 /00Z FRIDAY THROUGH TUESDAY/...
MVFR STRATOCUMULUS WILL GRADUALLY DISSIPATE EARLY TONIGHT...THEN
VFR WITH INCREASING HIGH CLOUDS. SHORT WAVE WILL MOVE EAST ON
FRIDAY WITH ASSOCIATED SHOWERS. THE WARM FRONT OVER THE MID
MISSISSIPPI VALLEY WILL TAKE A RUN NORTHWARD INTO MID OHIO AND
THUNDER IS POSSIBLE. FOR NOW WILL MENTION IT ONLY AT FDY AND MFD
WHICH SHOULD BE CLOSE TO THE WARM FRONT/TRIPLE POINT. CEILINGS
WILL COME DOWN AFTER THE SHOWERS/RAIN STARTS AND LOCAL IFR
CEILINGS WILL BE POSSIBLE ESPECIALLY AT SITES NEAR LAKE ERIE AS
THE FLOW BACKS TO THE NORTHEAST OFF THE LAKE LATE FRIDAY.
.OUTLOOK...NON VFR CONDITIONS LIKELY TO CONTINUE FRIDAY NIGHT 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
SHORT TERM...OUDEMAN
LONG TERM...KUBINA
AVIATION...KOSARIK
MARINE...GARNET
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
100 PM EDT WED MAR 28 2012
.SYNOPSIS...
A COLD FRONT WILL PASS SOUTHEAST THROUGH THE REGION TODAY...BRINGING
A CHANCE OF SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD IN
BEHIND THE FRONT...LEADING TO TRANQUIL CONDITIONS ON THURSDAY. ON
FRIDAY...A LOW PRESSURE SYSTEM WILL DEVELOP IN THE CENTRAL PLAINS
AND MOVE INTO THE REGION...BRINGING THE NEXT CHANCE OF
PRECIPITATION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
GOING FORECAST IN GOOD SHAPE AND ONLY MINOR TWEAKS NEEDED THIS
MORNING. 28.12Z KILN RAOB INDICATED IN EXCESS OF 1000 J/KG OF
ELEVATED INSTABILITY FOR PARCELS LIFTED FROM ABOUT 900MB...AND NO
DOUBT SOME OF THIS BEING REALIZED WITH SHOWERS/SCT STORMS SEEN ON
KILN WSR-88D THIS MORNING. FORCING FOR ASCENT THUS FAR DRIVEN BY
LOW LEVEL THETA-E ADVECTION JUST ABOVE THE INVERSION...AS SFC COLD
FRONT ATTENDANT TO THE GREAT LAKES SHORTWAVE TROUGH IS STILL BACK
IN NWRN OH INTO SWRN IND.
FRONT SHOULD PASS QUICKLY SOUTHEAST THROUGH THE ILN FORECAST AREA
THROUGH 6 PM...AND THERE IS REMARKABLE AGREEMENT FROM THE
CONVECTION ALLOWING MODELS /NSSL-WRF...NCEP ARW WRF...AND HRRR/
THAT CONVECTION WILL SLOWLY DEVELOP THROUGH THE DAY ALONG/JUST
AHEAD OF THE FRONT...PEAKING IN THE FAR SOUTHERN/SERN FORECAST
AREA BETWEEN 2PM AND 5 PM. BEST CHANCE FOR A STRONGER STORM IN THE
LOWER SCIOTO VALLEY AND NERN KY...WHERE BEST INSTABILITY /MLCAPE
AROUND 1000 J/KG/ WILL HAVE BUILT. 28.12Z RUC FORECAST SOUNDINGS
AT PMH VALID 20Z INDICATE DEEP WLY TROPOSPHERIC FLOW...AND
STRONG...SUGGESTING SOME STORM ORGANIZATION IS LIKELY BUT NOT
DIRECTIONAL SHEAR IS DEFINITELY LACKING. WIND/HAIL THE MAIN
THREATS IN THE FAR SOUTH.
BACK TO THE N/W BEHIND THE FRONT IN WCNTL/CNTL OH...AMPLE SUNSHINE
AND CRASHING DEWPOINTS/COLD ADVECTION WILL BRING WINDS UP IN THE
MID TO LATE AFTERNOON WHICH SHOULD GET SOME GUSTS ABOVE 30KTS IN
THE WIND PRONE AREAS. LAPSE RATES ON FCST SOUNDINGS ARE STEEP WITH
A STRONG FLOW IN THE BOUNDARY LAYER.
CHANGES THIS MORNING TO FORECAST TO BUMP WINDS UP JUST A BIT IN
THE NORTH...AND BUMP RAIN CHANCES IN THE SOUTH UP A BIT. OTHERWISE
FCST IN GOOD SHAPE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
HIGH PRESSURE WILL FILL IN BEHIND THE COLD FRONT FOR TONIGHT AND
THURSDAY...AS NORTHWEST FLOW CONTINUES ALOFT. THE COOL DOWN BEHIND
THE FRONT WILL RESULT IN A 10-15 DEGREE DROP FROM WEDNESDAY TO
THURSDAY...WITH WARM ADVECTION NOT REALLY KICKING BACK IN UNTIL
THURSDAY NIGHT. THIS WILL LEAD TO TWO NIGHTS ON THE COOL SIDE OF
THINGS. TEMPERATURES IN THE FAR NORTH ON WEDNESDAY NIGHT APPEAR
THAT THEY MAY BE COLD ENOUGH TO SUPPORT SOME FROST...ALTHOUGH A
LACK OF MOISTURE MAY PRECLUDE THIS FROM OCCURRING. CONDITIONS FOR
A FREEZE IN CENTRAL OHIO ON THURSDAY NIGHT LOOK SLIGHTLY LESS
FAVORABLE THAN THEY DID PREVIOUSLY (WITH A BUMP FORWARD IN TIMING
ON THE NEXT WEATHER SYSTEM)...BUT THERE IS CERTAINLY STILL ENOUGH
OF A CHANCE TO KEEP AN HWO MENTION.
MODEL GUIDANCE REMAINS IN POOR AGREEMENT FOR THE SYSTEM ON FRIDAY
AND SATURDAY. OF CONCERN IS THE FACT THAT THE ECMWF HAS BEEN
STEADY IN ITS SLOWER SOLUTION WITH A DEEPER MID-LEVEL
TROUGH...WHILE THE GFS AND NAM ARE BOTH IN REMARKABLE AGREEMENT ON
A FASTER PROGRESSION AND STRONGER SURFACE LOW. THUS...CONFIDENCE
IN THE FORECAST FROM FRIDAY AND BEYOND IS BELOW AVERAGE.
PRECIPITATION OVER THE FORECAST AREA IS CERTAIN TO OCCUR DURING
THIS TIME FRAME...AND THE OVERALL TREND HAS BEEN SLIGHTLY SPED UP
IN THIS FORECAST PACKAGE. ASIDE FROM THE PRECIPITATION
CHANCES...THE TRACK AND STRENGTH OF THE SURFACE LOW WILL ALSO HAVE
MAJOR IMPLICATIONS ON FRONTS...TEMPERATURES...AND ANY POTENTIAL
SEVERE THREAT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
TEMPERATURES WILL BE ABOVE NORMAL WITH HIGHS IN THE 60S AND 70S.
THE COOLEST DAY LOOKS TO BE SATURDAY WITH LOW TO MID 60S FORECAST
DUE TO COLD ADVECTION AND CLOUDS BEHIND THE LOW. THE WARMEST
READINGS INTO THE MID 70S ARE FORECAST FOR MONDAY WHEN ADVECTION
OCCURS AHEAD OF THE COLD FRONT.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
18Z TAFS WILL FEATURE VFR CONDITIONS FOR ALL THE SITES...AS IT IS
EXPECTED THAT THUNDERSTORM ACTIVITY WILL BE SOUTH/EAST OF
KCVG/KLUK BY 18Z. THEREFORE...TAFS MAINLY DEAL WITH GUSTY
AFTERNOON WINDS TODAY AS COLD FRONT SHIFTS THROUGH AND COLD
ADVECTION AND STEEPENING LAPSE RATES YIELD SOME WNWLY GUSTS TO 25
OR 30KTS. DO EXPECT SOME SCT CUMULUS TO FORM THIS AFTERNOON
ESPECIALLY NEAR CNTL OH BUT SHOULD BE VFR. WATCHING ANOTHER BATCH
OF STRATOCUMULUS OVER WI/LOWER MI THAT MAY TRY TO STRETCH INTO
CNTL OH AND THE MIAMI VALLEY LATER TONIGHT. RIGHT NOW THINKING IT
WILL BREAK UP/SCATTER AS IT DOES SO. WILL HINT AT THIS LOW
CONFIDENCE ITEM WITH SCTO25-SCT030 HOWEVER. FLOW SHOULD TURN NLY
OVERNIGHT AND NOT COMPLETELY DECOUPLE...WINDS STAYING ABOVE 5KTS
IN MOST AREAS. COULD EVEN TURN NELY FOR A TIME AT THE CINCINNATI
AREA TERMINALS. A QUIET THURSDAY IN STORE WITH RESIDUAL
STRATOCUMULUS /AT THIS TIME EXPECTED TO BE VFR AND SCATTERED/ WITH
LIGHT NLY FLOW.
OUTLOOK...THUNDERSTORMS POSSIBLE FRIDAY INTO SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...BINAU
SHORT TERM...HATZOS
LONG TERM...CONIGLIO
AVIATION...BINAU
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1017 AM EDT WED MAR 28 2012
.SYNOPSIS...
A COLD FRONT WILL PASS SOUTHEAST THROUGH THE REGION TODAY...BRINGING
A CHANCE OF SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD IN
BEHIND THE FRONT...LEADING TO TRANQUIL CONDITIONS ON THURSDAY. ON
FRIDAY...A LOW PRESSURE SYSTEM WILL DEVELOP IN THE CENTRAL PLAINS
AND MOVE INTO THE REGION...BRINGING THE NEXT CHANCE OF
PRECIPITATION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
GOING FORECAST IN GOOD SHAPE AND ONLY MINOR TWEAKS NEEDED THIS
MORNING. 28.12Z KILN RAOB INDICATED IN EXCESS OF 1000 J/KG OF
ELEVATED INSTABILITY FOR PARCELS LIFTED FROM ABOUT 900MB...AND NO
DOUBT SOME OF THIS BEING REALIZED WITH SHOWERS/SCT STORMS SEEN ON
KILN WSR-88D THIS MORNING. FORCING FOR ASCENT THUS FAR DRIVEN BY
LOW LEVEL THETA-E ADVECTION JUST ABOVE THE INVERSION...AS SFC COLD
FRONT ATTENDANT TO THE GREAT LAKES SHORTWAVE TROUGH IS STILL BACK
IN NWRN OH INTO SWRN IND.
FRONT SHOULD PASS QUICKLY SOUTHEAST THROUGH THE ILN FORECAST AREA
THROUGH 6 PM...AND THERE IS REMARKABLE AGREEMENT FROM THE
CONVECTION ALLOWING MODELS /NSSL-WRF...NCEP ARW WRF...AND HRRR/
THAT CONVECTION WILL SLOWLY DEVELOP THROUGH THE DAY ALONG/JUST
AHEAD OF THE FRONT...PEAKING IN THE FAR SOUTHERN/SERN FORECAST
AREA BETWEEN 2PM AND 5 PM. BEST CHANCE FOR A STRONGER STORM IN THE
LOWER SCIOTO VALLEY AND NERN KY...WHERE BEST INSTABILITY /MLCAPE
AROUND 1000 J/KG/ WILL HAVE BUILT. 28.12Z RUC FORECAST SOUNDINGS
AT PMH VALID 20Z INDICATE DEEP WLY TROPOSPHERIC FLOW...AND
STRONG...SUGGESTING SOME STORM ORGANIZATION IS LIKELY BUT NOT
DIRECTIONAL SHEAR IS DEFINITELY LACKING. WIND/HAIL THE MAIN
THREATS IN THE FAR SOUTH.
BACK TO THE N/W BEHIND THE FRONT IN WCNTL/CNTL OH...AMPLE SUNSHINE
AND CRASHING DEWPOINTS/COLD ADVECTION WILL BRING WINDS UP IN THE
MID TO LATE AFTERNOON WHICH SHOULD GET SOME GUSTS ABOVE 30KTS IN
THE WIND PRONE AREAS. LAPSE RATES ON FCST SOUNDINGS ARE STEEP WITH
A STRONG FLOW IN THE BOUNDARY LAYER.
CHANGES THIS MORNING TO FORECAST TO BUMP WINDS UP JUST A BIT IN
THE NORTH...AND BUMP RAIN CHANCES IN THE SOUTH UP A BIT. OTHERWISE
FCST IN GOOD SHAPE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
HIGH PRESSURE WILL FILL IN BEHIND THE COLD FRONT FOR TONIGHT AND
THURSDAY...AS NORTHWEST FLOW CONTINUES ALOFT. THE COOL DOWN BEHIND
THE FRONT WILL RESULT IN A 10-15 DEGREE DROP FROM WEDNESDAY TO
THURSDAY...WITH WARM ADVECTION NOT REALLY KICKING BACK IN UNTIL
THURSDAY NIGHT. THIS WILL LEAD TO TWO NIGHTS ON THE COOL SIDE OF
THINGS. TEMPERATURES IN THE FAR NORTH ON WEDNESDAY NIGHT APPEAR
THAT THEY MAY BE COLD ENOUGH TO SUPPORT SOME FROST...ALTHOUGH A
LACK OF MOISTURE MAY PRECLUDE THIS FROM OCCURRING. CONDITIONS FOR
A FREEZE IN CENTRAL OHIO ON THURSDAY NIGHT LOOK SLIGHTLY LESS
FAVORABLE THAN THEY DID PREVIOUSLY (WITH A BUMP FORWARD IN TIMING
ON THE NEXT WEATHER SYSTEM)...BUT THERE IS CERTAINLY STILL ENOUGH
OF A CHANCE TO KEEP AN HWO MENTION.
MODEL GUIDANCE REMAINS IN POOR AGREEMENT FOR THE SYSTEM ON FRIDAY
AND SATURDAY. OF CONCERN IS THE FACT THAT THE ECMWF HAS BEEN
STEADY IN ITS SLOWER SOLUTION WITH A DEEPER MID-LEVEL
TROUGH...WHILE THE GFS AND NAM ARE BOTH IN REMARKABLE AGREEMENT ON
A FASTER PROGRESSION AND STRONGER SURFACE LOW. THUS...CONFIDENCE
IN THE FORECAST FROM FRIDAY AND BEYOND IS BELOW AVERAGE.
PRECIPITATION OVER THE FORECAST AREA IS CERTAIN TO OCCUR DURING
THIS TIME FRAME...AND THE OVERALL TREND HAS BEEN SLIGHTLY SPED UP
IN THIS FORECAST PACKAGE. ASIDE FROM THE PRECIPITATION
CHANCES...THE TRACK AND STRENGTH OF THE SURFACE LOW WILL ALSO HAVE
MAJOR IMPLICATIONS ON FRONTS...TEMPERATURES...AND ANY POTENTIAL
SEVERE THREAT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
TEMPERATURES WILL BE ABOVE NORMAL WITH HIGHS IN THE 60S AND 70S.
THE COOLEST DAY LOOKS TO BE SATURDAY WITH LOW TO MID 60S FORECAST
DUE TO COLD ADVECTION AND CLOUDS BEHIND THE LOW. THE WARMEST
READINGS INTO THE MID 70S ARE FORECAST FOR MONDAY WHEN ADVECTION
OCCURS AHEAD OF THE COLD FRONT.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
A COLD FRONT WILL DROP SE ACROSS THE TAF SITES BETWEEN 16Z AND
20Z. ALTHOUGH THERE WILL BE INCREASING INSTABILITY AHEAD OF THE
FRONT...LOW LEVEL CONVERGENCE AND DYNAMICS DO NOT LOOK ALL THAT
IMPRESSIVE FOR THIS MORNING. AS A RESULT...HAVE ONLY EMPLOYED A
VCSH OR A VCTS AT THE TAF SITES BEFORE FRONTAL PASSAGE. MUCH
DRIER AIR WILL ADVECT IN BEHIND THE FRONT WILL ONLY SOME SCATTERED
CIRRUS EXPECTED THIS AFTERNOON. OF BIGGER CONCERN WILL BE THE
GUSTY WEST TO NORTHWEST WINDS OF 15 TO 20 KNOTS WITH GUSTS AROUND
30 KNOTS.
FOR TONIGHT...HIGH PRESSURE WILL BUILD SOUTHWARD INTO THE WESTERN
GREAT LAKES AND OHIO VALLEY. SKIES WILL BE MAINLY CLEAR WITH
DIMINISHING WINDS EXPECTED AFTER SUNSET.
OUTLOOK...THUNDERSTORMS POSSIBLE FRIDAY INTO SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...BINAU
SHORT TERM...HATZOS
LONG TERM...CONIGLIO
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
356 AM EDT WED MAR 28 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE EAST THROUGH THE UPPER GREAT LAKES
TODAY...PUSHING A COLD FRONT SOUTH ACROSS THE AREA BY TONIGHT. HIGH
PRESSURE WILL BUILD SOUTH OUT OF CANADA ON THURSDAY WITH COLDER
TEMPERATURES AND FROST POSSIBLE AGAIN ON THURSDAY NIGHT. ANOTHER
LOW PRESSURE SYSTEM WILL TRACK EAST ACROSS THE AREA ON FRIDAY
BRINGING ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A LOW PRESSURE SYSTEM WILL MOVE EAST ACROSS THE UPPER GREAT LAKES
TODAY...WITH WARM ADVECTION OCCURRING EARLY THIS MORNING...
FOLLOWED BY A WEAK COLD FRONT THAT WILL GRADUALLY SINK SOUTH LATE
THIS AFTERNOON. MOISTURE ADVECTION IS OCCURRING IN THE WARM SECTOR
ALTHOUGH UPSTREAM COVERAGE OF SHOWERS AND THUNDERSTORMS EARLY THIS
MORNING HAS BEEN UNIMPRESSIVE ACROSS INDIANA. 06Z SPC RUC ANALYSIS
SHOWS BETTER MOISTURE LOCATED IN CENTRAL ILLINOIS WHERE CONVECTION
CONTINUES TO FIRE IMMEDIATELY AHEAD OF THE COLD FRONT. ALTHOUGH
MOISTURE TRANSPORT WILL CONTINUE INTO NORTHERN OHIO THIS
MORNING...WONDERING IF THE BETTER MOISTURE IS GETTING PINCHED OFF
AS THE FLOW ALOFT BECOMES INCREASINGLY ORIENTED PARALLEL TO THE
FRONT. IT IS STILL POSSIBLE THAT WE WILL SEE AN UPTICK IN SHOWERS
AS THE FRONT SLIDES EAST ACROSS THE AREA THROUGH MID-MORNING WITH
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS STILL POSSIBLE.
CLOUDS WILL CLEAR OUT BY AFTERNOON AS THE DRY SLOT WORKS INTO THE
AREA FROM THE WEST. WE ARE EXPECTED TO MIX TO AROUND 850MB THIS
AFTERNOON UNDER MOSTLY SUNNY SKIES ALLOWING TEMPERATURES TO CLIMB
SEVERAL DEGREES WARMER THAN YESTERDAY...PEAKING IN THE LOW TO MID
60S BY EARLY AFTERNOON. WINDY CONDITIONS ARE ALSO EXPECTED WITH
WESTERLY WINDS NEAR 20 MPH AND GUSTS TO 35 MPH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
COLD ADVECTION WILL CONTINUE INTO TONIGHT WITH A POCKET OF COLD AIR
AT 850MB (-2 TO -4C) SETTLING SOUTHEAST OUT OF MICHIGAN TOWARDS NW
PA. THE COMBINATION OF INCREASING LOW LEVEL MOISTURE AND MOISTURE
OFF LAKE ERIE WILL RESULT IN PARTLY TO MOSTLY CLOUDY SKIES.
INSTABILITY OVER THE LAKE WILL BE MARGINAL FOR PURE LAKE EFFECT RAIN
SHOWERS...BUT ENOUGH LOW LEVEL MOISTURE SHOULD BE PRESENT TO SEE
SCATTERED LIGHT RAIN SHOWERS OFF THE LAKE OVER THE HIGHER TERRAIN OF
NE OH/NW PA. THE INCREASING CLOUD COVER AND BREEZY NORTHWESTERLY
WINDS WILL HELP TO PREVENT FROST TONIGHT...WITH LOWS GENERALLY
BOTTOMING OUT IN THE MID 30S.
CLOUDS WILL SCATTER OUT FROM WEST TO EAST ON THURSDAY AS HIGH
PRESSURE BUILDS SOUTHEAST OUT OF CANADA. OUR PROXIMITY TO THE
SOUTHERN FRINGE OF THE SURFACE HIGH ON THURSDAY NIGHT WITH MOSTLY
CLEAR SKIES WILL BE MORE FAVORABLE FOR FROST WITH LOWS FORECAST TO
DROP INTO THE MID 20S EAST TO MID 30S WEST. THERE WILL BE SOME HIGH
CLOUDS AROUND ON THURSDAY NIGHT BUT FROST/FREEZING CONDITIONS WILL
BE POSSIBLE AGAIN...MAINLY IN EASTERN PORTIONS OF THE FORECAST
AREA.
SHORTWAVE ENERGY APPROACHING THE WEST COAST WILL MAKE ITS WAY EAST
ACROSS THE PLAINS TOWARDS THE SOUTHERN GREAT LAKES BY FRIDAY. LIFT
WILL RAMP UP AND BECOME STRONG ALONG THE 925-850MB FRONT AS THE
SURFACE LOW TRACKS EAST INTO INDIANA ON FRIDAY. MODELS HAVE BEEN
TRENDING IN THIS DIRECTION FOR A COUPLE DAYS AND HAVE RAISED POPS
FOR FRIDAY AFTERNOON. ALTHOUGH THE SURFACE WARM FRONT MAY STRUGGLE
TO LIFT NORTH OF A DAYTON TO MARION LINE...ENOUGH ELEVATED
INSTABILITY WILL BE IN PLACE FOR THUNDERSTORMS AND COULD END UP WITH
A GOOD STEADY RAIN. HIGH PRESSURE WILL BUILD SOUTH OVER THE AREA
BEHIND THE DEPARTING SURFACE LOW ON SATURDAY WITH SHOWERS ENDING
FROM NORTH TO SOUTH DURING THE MORNING.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
FOLLOWED GFS TIMING FOR MOST OF THE EXTENDED. SUNDAY AND MONDAY
LOOK MILD WITH TEMPS INTO THE 70S DURING THE AFTERNOONS AND
NIGHTTIME LOWS 55 TO 60 SUNDAY NIGHT. DURING MONDAY A COLD FRONT
WILL MOVES THROUGH THE AREA FOLLOWED BY ANOTHER COLD FRONT MONDAY
NIGHT. BY TUESDAY MORNING EXPECT LOWS TO DROP THROUGH THE 40S.
HIGHS POST FRONT TUESDAY 55 TO 60 LOOK REASONABLE. AS FOR POPS WILL
KEEP FORECAST DRY SUNDAY AND THEN BRING IN A CHANCE POP FOR MONDAY
THROUGH TUESDAY WITH THE FRONT.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS ACROSS NRN OHIO AND NWRN PA AT 05Z. A WARM FRONT
EXTENDING NORTH/SOUTH ACROSS EASTERN OHIO WILL CONTINUE EAST. TO
THE WEST...A COLD FRONT IS APPROACHING ILLINOIS WHILE A SURFACE
TROF AHEAD OF THE FRONT IS RESPONSIBLE FOR SHOWERS AND
THUNDERSTORMS FROM VPZ VCNTY SW TO PIA VCNTY. THESE SHOWERS AND
THUNDERSTORMS WILL CONTINUE MOVING EAST AND SHOULD REACH INTO
WESTERN/NWRN OHIO AROUND 10-12Z BASED ON CURRENT TIMING. NOT
CONFIDENT ABOUT THUNDER SUSTAINING ACROSS THE ENTIRE AREA DURING
THE MORNING SO EAST OF MFD BACKED OFF TO JUST SHOWERS. EXPECT A
BRIEF PERIOD OF SHOWERS AS THE TROF MOVES THROUGH AND THEN CLOUDS
SHOULD BREAK UP AGAIN FOR MUCH OF THE LATE MORNING AND AFTERNOON
ACROSS THE AREA. WINDS HOWEVER WILL CONTINUE TO BE GUSTY WITH
WINDS FROM THE SSW GUSTING INTO THE 20-25 KNOT RANGE EXCEPT 30
KNOTS AT KERI OVERNIGHT AHEAD OF THE FRONT. POST FRONT WINDS WILL
TURN WEST-NORTHWEST AND GUST TO THE 30 KNOT RANGE THROUGH MUCH OF
THE AFTERNOON BEFORE DROPPING BACK THIS EVENING. LATE
AFTERNOON/EARLY EVENING EXPECT LOW VFR TO MVFR CIGS TO DROP ACROSS
THE AREA FROM THE NORTH.
.OUTLOOK...NON VFR LIKELY TONIGHT (WED NGT) INTO THURSDAY AND
AGAIN FRIDAY NIGHT INTO SATURDAY.
&&
.MARINE...
LOW PRESSURE JUST NORTH OF THE GREAT LAKES WILL MOVE EAST TO NEW
ENGLAND BY THIS EVENING DRAGGING A COLD FRONT ACROSS LAKE ERIE THIS
MORNING. WILL MOVE SMALL CRAFT UP TO ISSUE TIME. WINDS ON THE LAKE
AWAY FROM SHORE SHOULD BE LOWER THAN NEAR THE SHORELINE GIVEN THE
COLD WATER HOWEVER WINDS NEAR THE SHORELINE ARE CLOSE TO CRITERIA.
WOULD RATHER BE CAUTIOUS GIVEN THE DANGER OF THE COLD WATER. WINDS
AND WAVES WILL BE INCREASING THROUGH THE MORNING ESPECIALLY BEHIND
THE COLD FRONT. EXPECT WINDS IN THE 15 TO 25 KNOT RANGE WITH
WAVES APPROACHING 4 TO 6 FEET. WINDS/WAVES WILL DROP OFF TONIGHT.
HIGH PRESSURE WILL NOSE INTO THE AREA FROM THE NORTH FOR MID WEEK.
FRIDAY THE NAM MOVES A LOW ACROSS OHIO. THIS SHOULD BRING SHOWERS
AND THUNDERSTORMS TO THE LAKE WITH EAST WINDS TURNING NORTHEAST AT
15 TO 20 KNOTS OR SO DURING THE DAY. FRIDAY NIGHT THE WINDS WILL
TURN NORTH/NORTHWEST BEHIND THE LOW. WILL LIKELY NEED SMALL CRAFT
HEADLINES WITH THIS SYSTEM. SATURDAY ANOTHER HIGH WILL BUILD ACROSS
THE LAKE. SUNDAY THE HIGH WILL MOVE EAST ALONG THE MID ATLANTIC
COAST WITH LOW PRESSURE IN THE DAKOTAS. THIS SHOULD BRING MILD AIR
TO THE REGION AND SOUTHWEST TO WEST WINDS 10 TO 20 KNOTS TO THE
LAKE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
LEZ142>149.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC
SHORT TERM...KEC
LONG TERM...TK
AVIATION...TK
MARINE...TK
AREA FORECAST DISCUSSION
NWS NORMAN OK
1213 AM CDT WED MAR 28 2012
.AVIATION...ANTICIPATE DEVELOPMENT OF MVFR CEILINGS MOST TAF
SITES IN THE PERIOD 2809/2815 UTC. DID NOT GO AS PESSIMISTIC AS
THE IFR CEILINGS IN THE NAM GUIDANCE...BUT SOME IFR CONDITIONS
WILL BE POSSIBLE. STEADY SOUTH WINDS WILL CONTINUE THROUGH THE 24
HOUR PERIOD...WITH STRONGER SUSTAINED SPEEDS BEGINNING MIDDAY
THURSDAY. NO PRECIPITATION EXPECTED.
&&
.PREV DISCUSSION... /ISSUED 937 PM CDT TUE MAR 27 2012/
DISCUSSION...
ADJUSTMENTS WERE MADE TO SKY COVER FOR LATE TONIGHT. THE RUC AND
GFS AND HRRR ARE SIMILAR IN DEVELOPING LOW CLOUDS IN WESTERN
OKLAHOMA AND/OR ADVECTING THEM ACROSS SOUTHERN OKLAHOMA FROM THE
SOUTH. OTHERWISE LITTLE CHANGES ARE NECESSARY FOR THE OVERNIGHT
PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 58 82 60 81 / 10 10 20 20
HOBART OK 59 82 59 80 / 20 20 20 20
WICHITA FALLS TX 60 84 60 83 / 10 20 20 30
GAGE OK 54 85 56 85 / 20 20 30 20
PONCA CITY OK 58 83 61 84 / 20 20 30 20
DURANT OK 59 81 60 77 / 10 10 10 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
09/22/22
AREA FORECAST DISCUSSION
NWS TULSA OK
1137 PM CDT TUE MAR 27 2012
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
SHOWERS OVER CENTRAL OK HAVE LONG SINCE DISSIPATED AND ONLY
PASSING MID CLOUDS REMAIN. GRADUAL INCREASE IN MOISTURE WILL LEAD
TO CEILINGS IN THE 5-6KFT RANGE BY WEDNESDAY MORNING. ANY
THUNDERSTORMS THAT DEVELOP ALONG THE FRONTAL BOUNDARY ACROSS
KANSAS WILL LIKELY REMAIN TO OUR NORTH.
&&
.PREV DISCUSSION... /ISSUED 728 PM CDT TUE MAR 27 2012/
DISCUSSION...
THE LATEST DATA FROM THE NAM AND HRRR SUGGESTS THAT WE WILL REMAIN
CAPPED THIS EVENING IN THE WARM SECTOR SOUTH OF THE STALLED FRONT
OVER KS. THE 00Z OUN SOUNDING CONFIRMS THIS...WITH A STOUT EML
FROM 600MB DOWN TO AROUND 800MB. SOME HIGH BASED SHOWERS AND A FEW
LIGHTNING STRIKES OCCURRED EARLIER OVER CENTRAL OK ABOVE THE CAP
AT THE TOP OF THE EML...BUT THAT ACTIVITY HAS SINCE DISSIPATED.
ONE WOULD THINK THAT IF THERE IS ANY WARM ADV ACTIVITY TONIGHT IT
WOULD BE NORTH OF THE FRONT OVER KS...THUS I HAVE REMOVED THUNDER
MENTION FROM THE FORECAST TONIGHT. SOME SMALL TWEAKS WERE MADE TO
THE LOWS TONIGHT AS WELL. UPDATED PRODUCTS HAVE BEEN SENT.
LACY
PREV DISCUSSION... /ISSUED 602 PM CDT TUE MAR 27 2012/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
UPPER LEVEL DISTURBANCE WILL MOVE FROM CENTRAL OK INTO NE OKLAHOMA
THIS EVENING...HOWEVER SHOWERS ASSOCIATED WITH THIS SYSTEM APPEAR
UNLIKELY TO HOLD TOGETHER MUCH LONGER. THUS A DRY FORECAST FOR THE
EVENING WILL BE MAINTAINED WITH INCREASING MID CLOUDS. CEILINGS
EVENTUALLY WILL LOWER BUT SHOULD REMAIN ABOVE VFR LEVELS
THROUGHOUT THE PERIOD. ANY THUNDERSTORMS THAT DEVELOP ALONG A
FRONTAL BOUNDARY IN KANSAS WILL REMAIN NORTH OF ALL TAF SITES AS
WELL.
PREV DISCUSSION... /ISSUED 407 PM CDT TUE MAR 27 2012/
DISCUSSION...
FRONTAL BOUNDARY FROM NORTHWEST MISSOURI TO THE TEXAS
PANHANDLE WILL NOT REACH NORTHEAST OK OVERNIGHT GIVEN
SLIGHTLY SOUTH OF WEST UPPER FLOW. HOWEVER CONVECTION
OUT AHEAD OF THAT FRONT..MAY REACH..THE NORTHERN TIER
OF NORTHEAST OK COUNTIES. CHANCE POPS CARRIED ABOUT
I-44 NORTH TO KANSAS BORDER. BEST CHANCE NEAR KANSAS.
NORTHERN TIER OF ZONES REMAIN WITH LOW POPS WEDNESDAY
WHERE INSTABILITY GREATEST AND INCREASING LOW LEVEL
MOISTURE SUPPORTS HEALTHY THUNDER IF THUNDER DEVELOPS.
CHANCE POPS CONTINUE WEDNESDAY NIGHT THROUGH THURSDAY
NIGHT. A WAVE IN THE UPPER FLOW SHOULD ENHANCE PRECIP
CHANCES FRIDAY AND FRIDAY NIGHT. KEPT POPS JUST BELOW
LIKELY THRESHOLD FRIDAY. FIRST HALF OF WEEKEND LOOKS
IFFY DEPENDING ON WAVE SPEED. ECMWF ABOUT STATE AHEAD
OF LINGERING GFS. AS USUAL LEANED EUROPEAN. CONTINUED
TO LEAN ECMWF THROUGH REMAINDER OF FORECAST.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...14
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
910 PM CDT THU MAR 29 2012
.DISCUSSION...AS THE MESOSCALE CONVECTIVE VORTEX LIFTED INTO
SOUTHEAST TEXAS LATE THIS AFTERNOON...AIR MASS BECAME STRONGLY
UNSTABLE OVER THE COASTAL PLAINS WITH LIFTED INDECES AROUND -10
DEGREES AND CAPE VALUES AROUND 3000 J/KG. STRONG TO SEVERE
STORMS DEVELOPED ALONG THE SEA BREEZE WITH THE MOST SEVERE
AFFECTING ROBSTOWN WITH DAMAGING WINDS AND HAIL UP TO 2 INCHES.
MOST OF THE ACTIVITY DIMINISHED WITH THE LOSS OF HEATING AND
WEAK STABILIZATION BEHIND THE SEA BREEZE. BUT MORE ACTIVITY
LINGERING OVER DEEP SOUTH TEXAS HAS SHOWN A DRIFT TO THE
NORTHEAST AHEAD OF AN UPPER LEVEL SHORT WAVE TROUGH NORTH
OF MONTERREY MOVES EAST-NORTHEAST. WILL MODIFY POPS TO SHOW
BEST CHANCES FROM SOUTHWEST TO LIMITED NORTHEAST AND OVER THE
GULF WATERS. MODELS SHOW THIS VERY UNSTABLE AIRMASS TO REMAIN
OVER THE REGION FOR FRIDAY. FORECAST INSTABILITY FIELDS SHOW
CAPE FROM 3500-4000 J/KG OVER THE INLAND COASTAL PLAINS AND
BRUSH COUNTRY WITH LIFTED INDEX VALUES AROUND -11 TO -12
DEGREES WITH LIMITED CONVECTIVE INHIBITION. RAISED POPS TO
LOW END CHANCE OVER MOST OF THE BRUSH COUNTRY TO INLAND COASTAL
PLAINS FRIDAY AFTERNOON. POTENTIAL FOR ISOLATED SEVERE
THUNDERSTORMS AGAIN TOMORROW AFTERNOON INTO THE EVENING.
&&
.PREV DISCUSSION... /ISSUED 642 PM CDT THU MAR 29 2012/
DISCUSSION...SEE AVIATION SECTION BELOW.
AVIATION...ONGOING CONVECTION ALONG A SEA BREEZE THIS AFTERNOON
WILL CONTINUE TO MOVE SLOWLY WEST THRU THE EVENING HOURS. AREAS
AHEAD OF AND IN THE WAKE OF THE SEA BREEZE ARE GENERALLY VFR.
THESE STORMS ARE EXPECTED TO DIMINISH OVER THE NEXT TWO TO THREE
HOURS...HOWEVER THUNDERSTORMS ACROSS MEX ARE EXPECTED TO AFFECT
LRD LATER THIS EVENING TOWARD MIDNIGHT. THIS SYSTEM IS EXPECTED TO
GENERALLY MOVE E TO SE OVERNIGHT ACROSS S TX. GENERALLY MVFR CIGS
ARE EXPECTED TO DVLP OVERNIGHT WITH IFR/LIFR CONDITIONS IN AND
NEAR TSRA`S. ONCE THIS STORM SYSTEM HAS EXITED THE AREA...VFR
CONDITIONS ARE EXPECTED TO DVLP BY FRI AFTERNOON.
PREV DISCUSSION... /ISSUED 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 69 86 68 86 68 / 40 30 30 20 10
VICTORIA 67 84 67 84 68 / 20 20 20 20 10
LAREDO 68 92 69 93 69 / 50 20 50 10 10
ALICE 68 89 66 89 68 / 50 30 40 10 10
ROCKPORT 69 82 69 80 70 / 20 20 20 20 10
COTULLA 67 86 65 88 67 / 40 30 50 10 10
KINGSVILLE 69 87 68 88 67 / 50 30 30 20 10
NAVY CORPUS 71 81 68 82 69 / 30 20 20 20 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TMT/89...SHORT TERM
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
642 PM CDT THU MAR 29 2012
.DISCUSSION...SEE AVIATION SECTION BELOW.
&&
.AVIATION...ONGOING CONVECTION ALONG A SEA BREEZE THIS AFTERNOON
WILL CONTINUE TO MOVE SLOWLY WEST THRU THE EVENING HOURS. AREAS
AHEAD OF AND IN THE WAKE OF THE SEA BREEZE ARE GENERALLY VFR.
THESE STORMS ARE EXPECTED TO DIMINISH OVER THE NEXT TWO TO THREE
HOURS...HOWEVER THUNDERSTORMS ACROSS MEX ARE EXPECTED TO AFFECT
LRD LATER THIS EVENING TOWARD MIDNIGHT. THIS SYSTEM IS EXPECTED TO
GENERALLY MOVE E TO SE OVERNIGHT ACROSS S TX. GENERALLY MVFR CIGS
ARE EXPECTED TO DVLP OVERNIGHT WITH IFR/LIFR CONDITIONS IN AND
NEAR TSRA`S. ONCE THIS STORM SYSTEM HAS EXITED THE AREA...VFR
CONDITIONS ARE EXPECTED TO DVLP BY FRI AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 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.
&&
$$
TT/89...SHORT TERM
TE/81...AVIATION
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
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 / 20 20 20 10 10
ASPERMONT 61 87 58 87 56 / 10 20 20 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33/93
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
1233 PM CDT WED MAR 28 2012
.DISCUSSION...
SEE 18Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
CURRENTLY...THERE IS AN AREA OF SHOWERS AND THUNDERSTORMS MOVING
NORTH/NORTHWEST TOWARD THE KBBD TERMINAL. THIS IS LIKELY A RESULT
OF A SMALL MID LEVEL DISTURBANCE SPINNING OVER THE WESTERN HILL
COUNTRY AREA. EXPECT THIS ACTIVITY TO IMPACT BRADY BETWEEN NOW
AND 19Z BEFORE GENERALLY DISSIPATING. ALSO EXPECT MOST OF THE
ACTIVITY ASSOCIATED WITH THIS DISTURBANCE TO BEGIN MOVING EASTWARD
AS THE DISTURBANCE DOES AS WELL. OVERNIGHT...WE MAY SEE ISOLATED
TO SCATTERED THUNDERSTORMS DEVELOP WEST OF THE AREA...AND TRY TO
MOVE EAST TOWARD OUR TAF SITES...BUT EXPECT THE ACTIVITY TO
DISSIPATE DURING THE EVENING HOURS BEFORE GETTING A CHANCE TO MAKE
SIGNIFICANT PROGRESS INTO OUR FORECAST AREA. OVERNIGHT...SOUTHEAST
WINDS SHOULD CONTINUE. MODEL SOUNDINGS SUGGEST THAT LOW CLOUDS
WILL STRUGGLE TO IMPACT KSJT AND KABI...SO HAVE ONLY INCLUDED A
SCT020 GROUP FOR THESE SITES DURING THE EARLY MORNING HOURS WHILE
MVFR CIGS ARE EXPECTED TO IMPACT KSOA...KJCT AND KBBD. 20
&&
.PREV DISCUSSION... /ISSUED 1042 AM CDT WED MAR 28 2012/
DISCUSSION...
HAVE MADE SOME MINOR ADJUSTMENTS TO CLOUD COVER AND MAX TEMPS FOR
TODAY AS WELL AS WX/POP GRIDS TO ACCOUNT FOR DEVELOPING
SHOWERS/STORMS ACROSS OUR SOUTHEASTERN COUNTIES. THE HRRR SHOWS
THIS ACTIVITY DISSIPATING DURING THE AFTERNOON...SO WILL KEEP THE
AREA CONFINED TO OUR SOUTHEASTERN COUNTIES FOR NOW...AND KEEP AN
EYE ON IT. HAVE SLIGHTLY LOWERED MAX TEMPS FOR SOUTHERN AREAS
WHERE MORE CLOUD COVER AND THE AFOREMENTIONED PRECIPITATION IS
OCCURRING. UPDATED GRIDS HAVE BEEN PUBLISHED. 20
PREV DISCUSSION... /ISSUED 555 AM CDT WED MAR 28 2012/
DISCUSSION...
/SEE BELOW FOR AVIATION DISCUSSION/
AVIATION...
STRATUS WITH MVFR CIGS WAS REDEVELOPING ACROSS WEST CENTRAL THIS
MORNING...HAVING BEEN PARTIALLY DISRUPTED BY MCS OVER SOUTH CENTRAL
TEXAS. CIGS EXPECTED TO LIFT OR SCATTER OUT BY LATE MORNING ACROSS
WEST CENTRAL TEXAS. WHILE AN ISOLATED THUNDERSTORM POSSIBLE LATE
AFTERNOON AND EVENING...BEST CHANCE OF STORMS WILL NEAR
SONORA...MAINLY AFTER 3Z. HAVE STRATUS WITH MVFR CIGS RETURNING AT
CLIMATOLOGICAL FAVORABLE TIMES TONIGHT...6Z AT KJCT AND KSOA...7Z
AT KBBD...AND 9Z AT SJT.
PREV DISCUSSION... /ISSUED 348 AM CDT WED MAR 28 2012/
SHORT TERM...
MCS THAT MOVED THROUGH CROCKETT AND SUTTON COUNTIES OVERNIGHT...WAS
MOVING THROUGH THE HILL COUNTRY AND RIO GRANDE RIVER THIS
MORNING...AS FAR SOUTH AS LAREDO. MCS DEVELOPED IN THE HIGHER
ELEVATIONS AROUND FT STOCKTON YESTERDAY AFTERNOON...THEN MOVED
SOUTHEAST. IT HAS LEFT AN OUTFLOW BOUNDARY IN THE CONCHO VALLEY.
WITH DAYTIME HEATING...POTENTIAL EXISTS FOR SOME ISOLATED
THUNDERSTORMS TO DEVELOP ALONG THE REMNANT THUNDERSTORM OUTFLOW
BOUNDARY LATE AFTERNOON. THERE IS A BETTER CHANCE OF STORMS TONIGHT
HOWEVER...TO THE WEST AND SOUTH OF THE CONCHO VALLEY...AS BOTH NAM
AND GFS MODELS INDICATED ANOTHER AREA OF CONVECTION TO REDEVELOP IN
HIGHER ELEVATIONS AROUND FORT STOCKTON...THEN MOVE SOUTHEAST.
APPROACH OF AN UPPER TROUGH NEAR BAJA CALIFORNIA WILL HELP PROVIDE
ADDITIONAL LIFT. DEVELOPMENT AND PATH OF MCS REMAINS PROBLEMATIC
HOWEVER... AS STEERING CURRENTS ALOFT ARE WEAK...AND MCS MOVEMENT
WILL BE DEPENDENT IF OR WHERE A STRONG COLD POOL DEVELOPS. WILL KEEP
HIGHEST POPS OVER CROCKETT COUNTY TONIGHT.
LONG TERM...
UPPER LEVEL SHORTWAVE EVIDENT ON WATER VAPOR NEAR BAJA WILL SLIDE
INTO WEST CENTRAL TEXAS FOR THURSDAY...AIDING CONVECTIVE DEVELOPMENT. RIGHT
NOW...WILL FOCUS POPS ON THURSDAY ACROSS THE SOUTHERN
COUNTIES...WHERE A REMNANT MCS FROM TONIGHT AND/OR ITS BOUNDARIES
MAY STILL BE IN THE AREA...AND ALONG THE WESTERN CONCHO VALLEY AND
BIG COUNTRY ALONG THE DRYLINE. WILL THEN SPREAD THE RAIN CHANCES
AREAWIDE FOR THURSDAY NIGHT. STILL SOME QUESTION ABOUT THE SPEED
OF THE SHORTWAVE AND HOW QUICKLY IT WILL EXIT TO THE EAST...BUT
FOR RIGHT NOW...WILL CONTINUE THE TREND IN THE CURRENT FORECAST
AND WILL CARRY SLIGHT SOME POPS FOR THE EASTERN AREA INTO FRIDAY
AS WELL.
UPPER LEVEL SUPPORT FOR ANY CONVECTIVE DEVELOPMENT OVER THE
WEEKEND WILL BE QUESTIONABLE...AND BEST INSTABILITY WILL BE ALONG
THE EASTERN BORDER OF THE AREA. COULD RUN ISOLATED POPS FOR THE
FEW STORMS THAT MAY DEVELOP...BUT AT THIS POINT...WILL JUST OPT TO
NOT INCLUDE A MENTION AT ALL. FAIRLY STRONG FRONTAL BOUNDARY MOVES
THROUGH THE AREA ON MONDAY...KNOCKING DOWN THE WELL ABOVE
TEMPERATURES DOWN TO SOMETHING CLOSER TO NORMAL.
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 61 84 61 85 57 / 10 20 30 20 10
SAN ANGELO 60 83 60 84 56 / 20 30 30 20 10
JUNCTION 61 80 62 80 57 / 20 30 40 20 20
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1201 AM CDT WED MAR 28 2012
.AVIATION...
MCS PROGRESSING ACROSS THE RIO GRANDE PLAINS IS EXPECTED TO DIE
OUT BEFORE REACHING KSAT/KSSF. HOWEVER...MODELS HAVE HAD A HARD
TIME WITH THE MCS THIS EVENING...AND MAY NEED TO SEND AN UPDATE BY
ABOUT 08Z. OTHERWISE...MVFR STRATUS WILL DEVELOP OVERNIGHT...THOUGH
CURRENTLY HAVE MUCH LOWER CONFIDENCE AS FAR AS TIMING DUE TO THE
AFOREMENTIONED THUNDERSTORMS. HAVE KEPT A MIX OF FOG AND LOW
STRATUS OVERNIGHT AND GRADUALLY RETURNING TO VFR BY ABOUT 18Z.
&&
.PREV DISCUSSION... /ISSUED 916 PM CDT TUE MAR 27 2012/
UPDATE...
MCS ENTERING THE FAR WESTERN VAL VERDE COUNTY...WITH THE LEADING
EDGE OF STORMS HAVE SHOWN A SLIGHT WEAKENING TREND THE LAST HOUR.
00Z RUC AND NAM SHOW CONVECTION WEAKENING THRU 06Z...ALTHOUGH WILL
KEEP LOW POPS IN ACROSS THE RIO GRANDE PLAINS OVER THE WESTERN 3RD
OF THE CWA A FEW HOURS LONGER...SIMILAR TO LAST NIGHT. OTHERWISE
ONGOING FORECAST IN GOOD SHAPE AND NO MAJOR CHANGES WILL BE
NEEDED.
PREV DISCUSSION... /ISSUED 635 PM CDT TUE MAR 27 2012/
AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGH THE EVENING. THE COMPLEX OF
THUNDERSTORMS ACROSS THE BIG BEND REGION IS MAKING SLOW S/SW-WRD
PROGRESS THIS EVENING. LATEST RUC ANALYSIS SUGGESTS THAT THE TSRA
WILL CONTINUE TO MOVE SW-WRD THIS EVENING...BUT SHEAR APART/DISSIPATE
BEFORE REACHING KDRT. HAVE THEREFORE OPTED TO MENTION CB AROUND KDRT
LATER TONIGHT...BUT CONFIDENCE IS TOO LOW TO WARRANT EXPLICIT
MENTION OF TSRA AT THE TERMINAL. OTHERWISE...SHRA/TSRA EARLIER
THIS AFTERNOON ACROSS THE RIO GRANDE PLAINS AND ADJACENT AREAS IS
RAPIDLY TRENDING DOWNWARD AND SHOULD CONTINUE TO DO SO WITH THE
LOSS OF DAYTIME HEATING. ANTICIPATE ANOTHER ROUND OF MVFR STRATUS
AOB 2KFT TO SETTLE IN ALONG THE I-35 CORRIDOR BY ABOUT 06Z. CIGS
WILL LOWER AND SPREAD WEST OVERNIGHT...WITH LIFR CIGS POSSIBLE AT
KAUS/KSAT/KSSF IN THE NEAR-DAYBREAK HOURS. SIMILAR TO
TODAY...CONDITIONS WILL BE SLOW TO IMPROVE...BUT VFR CONDITIONS
WILL RETURN AROUND/AFTER 18Z.
PREV DISCUSSION... /ISSUED 331 PM CDT TUE MAR 27 2012/
DISCUSSION...
THE SOUTHERN PLAINS SITS UNDER THE BACKSIDE OF AN UPPER LEVEL
RIDGE FROM 700-250MB THIS AFTERNOON. WE ARE BEGINNING TO SEE A
SLOW SHIFT IN THE PATTERN. HEIGHTS HAVE FALLEN SLIGHTLY OVER THE
PAST DAY. THIS COMBINED WITH STRONG HEATING OVER THE MOUNTAINS IN
NORTHERN MEXICO IS ALLOWING THUNDERSTORMS TO FORM. SIMILAR TO LAST
NIGHT EXPECT STORMS THROUGH THE EVENING...BUT QUESTION IS WHETHER
THEY CAN MAKE ACROSS THE PLAINS INTO TX. ATMOSPHERE IS FAIRLY
CAPPED OVER OUR CWA...SO HAVE ONLY SLIGHT CHANCE POPS OVER THE
WESTERN THIRD OF THE AREA. ANY STORMS THAT DO MAKE IT ACROSS MAY
BE STRONG WITH SMALL HAIL AND GUSTY WINDS. WED LOOKS VERY SIMILAR
TO TODAY WITH PERHAPS A LITTLE BETTER CHANCE OF STORMS MAKING
ACROSS NORTHERN MEXICO INTO TX. THU THE UPPER TROUGH WHICH IS OVER
THE WEST COAST WILL APPROACH TX AND THIS WILL BRING A BETTER
CHANCE FOR THUNDERSTORMS TO MORE OF THE AREA. AT THIS TIME MODEL
SOUNDINGS SUGGEST STORMS WILL BE NOT BE PARTICULARLY STRONG WITH
MODERATE INSTABILITY AND VERTICAL WIND SHEAR. THE UPPER TROUGH
SHOULD CLEAR THE AREA BY FRI EVENING LEAVING DRY WEATHER FOR THE
WEEKEND. ECMWF AND GFS ARE BOTH SHOWING A COLD FRONT EARLY NEXT
WEEK...BUT DIFFER ON ITS STRENGTH. GFS IS STRONGER. HAVE TRENDED
TOWARD THE WEAKER ECMWF AND INCREASED TEMPS FOR MON AND TUE.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 64 81 63 79 61 / 10 10 10 20 40
AUSTIN BERGSTROM INTL AIRPORT 63 81 61 79 60 / 10 10 10 20 40
NEW BRAUNFELS MUNI AIRPORT 64 80 62 77 60 / 10 10 10 20 40
BURNET MUNI AIRPORT 63 80 61 77 61 / 10 10 10 20 40
DEL RIO INTL AIRPORT 67 83 67 78 64 / 40 10 30 40 50
GEORGETOWN MUNI AIRPORT 62 78 61 77 60 / 10 10 10 20 40
HONDO MUNI AIRPORT 65 82 64 77 62 / 20 10 20 40 50
SAN MARCOS MUNI AIRPORT 63 80 62 78 60 / 10 10 10 20 40
LA GRANGE - FAYETTE REGIONAL 63 80 61 78 61 / 10 - 10 20 30
SAN ANTONIO INTL AIRPORT 66 81 64 77 63 / 10 10 10 30 50
STINSON MUNI AIRPORT 67 82 65 77 63 / 10 10 10 30 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...25
SYNOPTIC/GRIDS...01
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
347 PM CDT WED MAR 28 2012
.SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
347 PM CDT WED MAR 28 2012
AT 3 PM...A 1020 MB SURFACE HIGH WAS CENTERED OVER THE EASTERN
DAKOTAS AND WESTERN MINNESOTA. THIS HIGH WILL DRIFT EAST ACROSS
THE AREA TONIGHT. MEANWHILE A TROUGH OF LOW PRESSURE...LOCATED
OVER NORTHEAST WISCONSIN...WAS PRODUCING A BROKEN DECK OF CLOUDS
ACROSS NORTHERN MINNESOTA...AND NORTHERN AND EASTERN WISCONSIN.
THE VISIBLE SATELLITE LOOP SHOWS THAT THESE CLOUDS ARE CELLULAR IN
NATURE...THEREFORE...EXPECT THAT THESE CLOUDS WILL CONTINUE TO
QUICKLY ERODE AND DISSIPATE LATE THIS AFTERNOON AND EVENING.
WITH CLEAR SKIES AND LIGHT WINDS EXPECTED TONIGHT...TEMPERATURES
ALONG AND NORTH OF THE INTERSTATE 94 CORRIDOR WILL LIKELY FALL
INTO THE UPPER 20S. DUE TO THIS...A FREEZE WARNING HAS BEEN
ISSUED FOR THESE AREAS. DUE TO THE URBAN HEAT ISLAND AND THE
PROXIMITY TO THE UNUSUALLY WARM MISSISSIPPI RIVER...THE CITY OF
LA CROSSE MAY NOT SEE FROST...BUT THE REMAINDER OF LA CROSSE
COUNTY WILL LIKELY SEE FROST ALONG WITH BUFFALO...TREMPEALEAU...AND
VERNON COUNTIES. DUE TO THIS...A FROST ADVISORY HAS BEEN ISSUED
FOR THESE COUNTIES FOR TONIGHT.
ON THURSDAY...THE CLOUDS WILL BE ON THE INCREASE AS A SHORT WAVE
TROUGH MOVES TOWARD THE REGION FROM THE DAKOTAS. THIS SYSTEM WILL
THEN MOVE EAST THROUGH THE REGION ON THURSDAY NIGHT AND EARLY
FRIDAY MORNING. THIS IS A BIT FASTER THAN PREVIOUS MODEL RUNS...
SO THE PRECIPITATION WAS REMOVED FOR FRIDAY AFTERNOON. ALONG WITH
SHOWERS...THE MOST UNSTABLE CAPES CLIMB UP TO 250 J/KG. DUE TO
THIS...KEPT ISOLATED THUNDERSTORMS IN THE FORECAST FROM LATE
THURSDAY AFTERNOON INTO THURSDAY NIGHT.
ON FRIDAY AND FRIDAY NIGHT...ANOTHER AREA OF COOLER AIR WILL SPILL
INTO THE WESTERN GREAT LAKES BEHIND THE DEPARTING SHORT WAVE
TROUGH. BOTH OF THESE TIME PERIODS HAVE BEEN GETTING PROGRESSIVELY
COOLER ACROSS WISCONSIN. DUE TO THIS...LOWERED THE TEMPERATURES A
FEW MORE DEGREES THAN THE PREVIOUS FORECAST. UNLIKE TONIGHT...
THERE LOOKS LIKE THERE MAY BE A BIT MORE CLOUDS. HOWEVER IF THERE
IS LESS CLOUDS...WE MAY HAVE ANOTHER NIGHT FOR POTENTIAL FROST AND
FREEZE HEADLINES ACROSS CENTRAL AND NORTH-CENTRAL WISCONSIN.
.LONG TERM...SATURDAY THROUGH WEDNESDAY
347 PM CDT WED MAR 28 2012
ON SATURDAY...THE MODELS CONTINUE TO SHOW THAT THE COLDER AIR WILL
BE MUCH SLOWER AT MOVING OUT OF THE WESTERN GREAT LAKES. AS A
RESULT...LOWERED THE MAXIMUM TEMPERATURES A FEW MORE DEGREES.
THESE TEMPERATURES ARE NOT QUITE AS COLD WHAT THE ECMWF OR GEM IS
INDICATING...SO THEY MAY HAVE TO BE LOWERED EVEN MORE.
ON SUNDAY...850 MB TEMPERATURES WILL CLIMB INTO 16 TO 18C RANGE
AND SOUTHERLY WINDS IN THE 10 TO 20 KNOT RANGE. THIS WILL ALLOW
TEMPERATURES TO CLIMB WELL INTO MID AND UPPER 70S. THERE MAY BE
EVEN A FEW LOW 80S.
ON SUNDAY NIGHT...IT LOOKS LIKE THE COLD FRONT WILL BE A BIT
SLOWER MOVING INTO THE REGION. AS A RESULT...THE PRECIPITATION
CHANCES WERE REMOVED FROM THE FORECAST.
&&
.AVIATION...THROUGH 18Z THURSDAY
1236 PM CDT WED MAR 28 2012
MAIN AVIATION FORECAST CONCERNS IS LOW PRESSURE OVER THE GREAT LAKES
REGION WRAPPING STRATOCUMULUS CLOUD DECK INTO THE REGION THIS
AFTERNOON AND INTO THE EARLY EVENING HOURS. CEILING HEIGHTS WITHIN
THE STRATOCUMULUS DECK ARE IN THE MVFR RANGE OF 2000 TO 3500 FEET.
THE COMBINATION OF ABUNDANT SUNSHINE AHEAD OF THE DECK OF CLOUDS
AND SURFACE HIGH PRESSURE BUILDING INTO THE AREA FROM THE NORTHERN
PLAINS...STRATOCUMULUS DECK IS SLOWLY ERODING ON SOUTHERN FLANK
PER LATEST VISIBLE SATELLITE IMAGERY. LATEST 28.15Z RUC AND 28.12Z
NAM SHOW STRATOCUMULUS DECK TO HOLD TOGETHER BEFORE ERODING LATE
THIS AFTERNOON AND EARLY EVENING HOURS PER RELATIVE HUMIDITY
FIELDS AT 850MB AND 925MB. FOR NOW...HAVE INTRODUCED BROKEN LAYER
AT MVFR CONDITIONS AT KRST AND ADDED A TEMPO GROUP OF SCATTERED
CLOUDS THROUGH 22Z WEDNESDAY. AT KLSE...CEILINGS HEIGHTS SHOULD BE
ABOVE 3000 FEET AND IN THE VFR RANGE. NEXT AVIATION CONCERN IS
APPROACHING COLD FRONT FOR THURSDAY. LATEST DETERMINISTIC 28.12Z
MODELS SHOW PRESSURE GRADIENT TIGHTENING AND WIND DIRECTION
SHIFTING TO SOUTHEAST AFTER 13Z THURSDAY. SUSTAIN WIND SPEEDS ARE
EXPECTED TO BE AROUND 15 KNOTS AND GUST UP TO AROUND 20
KNOTS...ESPECIALLY AT KRST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
253 PM CDT WED MAR 28 2012
WI...FROST ADVISORY FROM 1 AM TO 9 AM CDT THURSDAY FOR WIZ032-033-041-
053.
FREEZE WARNING FROM 1 AM TO 9 AM CDT THURSDAY FOR WIZ017-029-034-
042>044.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...DTJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1237 PM CDT WED MAR 28 2012
.SHORT TERM...
356 AM CDT WED MAR 28 2012
FORECAST CONCERNS THIS PACKAGE...FROST POTENTIAL TONIGHT...RAIN
CHANCES CENTERED ON THU NIGHT...TEMPERATURES.
DATA ANALYSIS AT 06Z HAD A BROAD AREA OF LOW PRESSURE CENTERED JUST
NORTH OF LK SUPERIOR. PRESSURE GRADIENT AROUND THIS LOW STILL
EXTENDED ACROSS MN/WI/MUCH OF IA AND CONTINUED TO RELAX EARLY
THIS MORNING. WINDS ACROSS MOST OF MN/WI REMAINED IN THE 10-20KT
RANGE. CLOUDS IN THE CIRCULATION AROUND THE LOW COVERED CENTRAL/
NORTHERN MN AND WI NORTH OF HWY 29...WITH GENERALLY CLEAR SKIES
ELSEWHERE ACROSS THE UPPER MIDWEST. TEMPS ACROSS THE REGION COOLING
IN THE WEST/NORTHWEST FLOW BUT REMAINED WELL ABOVE NORMAL.
28.00Z MODELS INITIALIZED WELL. SOLUTIONS QUITE SIMILAR FOR TODAY
THRU THU THEN DIVERGE WITH THE STRENGTH/TIMING OF THE SHORTWAVE AND
SFC LOW/TROUGH TO MOVE ACROSS THE MID/UPPER MS VALLEY THU NIGHT.
DPROG/DT OF 500MB HGTS AT 28.00Z SHOWED THE RUNS OF 26.00Z AND
27.00Z VERIFIED WELL ACROSS NOAM/EASTERN PAC WITH BETTER RUN-TO-RUN
CONSISTENCY BY ECMWF. MODELS CONVERGING TOWARD A TIGHTER CONSENSUS
THRU THU AS THE NEXT SHORTWAVE ENERGY FROM THE PACIFIC MOVES INTO
THE CENTRAL/NORTHERN PLAINS BY 00Z FRI. FROM THERE MODELS DIVERGE
WITH THE EVOLUTION OF THIS TROUGH AS IT MOVES EAST THRU THE REGION
THU NIGHT/FRI. SOMEWHAT BETTER RUN-TO-RUN CONSISTENCY BY ECMWF THU
NIGHT THRU FRI NIGHT...BUT COULD BE BETTER. CHECK OF OBS VS. MODEL
DATA AT 06Z SHOWED MODELS ON TRACK WITH THE SFC FEATURES OVER
CENTRAL NOAM. PER WV IMAGERY...ECMWF/GEM LOOKED BETTER THAN
NAM/GFS/MET WITH THE SHORTWAVE ENERGY IN THE TROUGH APPROACHING THE
WEST COAST. ECMWF/GEM ARE A COUPLE OF THE SLOWER SOLUTIONS WITH THIS
ENERGY AS IT CROSSES THE MID/UPPER MS VALLEY THU NIGHT/FRI. WITH
ECMWF/GEM LOOKING BETTER AT 06Z...FAVORED A MODEL/ENSEMBLE CONSENSUS
WEIGHTED TOWARD THEM ESPECIALLY THU NIGHT/FRI. HOWEVER GIVEN THE
MODEL SPREAD FCST CONFIDENCE FALLS TO AVERAGE FOR THU NIGHT THRU FRI
NIGHT.
FOR THE SHORT TERM...THE LOW NORTH OF LK SUPERIOR MOVES QUICKLY AWAY
FROM THE REGION TODAY. HOWEVER MDT 925 PRESSURE GRADIENT/WINDS
REMAIN OVER THE AREA MUCH OF THE DAY. WITH PLENTY OF SUNSHINE AND
MODEL SOUNDINGS INDICATING MIXING TO AROUND 900MB...WINDS WILL
REMAIN BRISK/BREEZY TODAY. SFC RIDGE AXIS DRIFTS RATHER QUICKLY EAST
ACROSS THE AREA TONIGHT...AND IS OVER EASTERN WI BY 12Z THU. WINDS
BECOME LIGHT THIS EVENING BUT APPEARS WINDS MAY STIR/INCREASE A BIT
LATE TONIGHT...ESPECIALLY OVER THE WEST HALF OF THE FCST AREA.
COLDEST OF THE LOW LEVEL AIRMASS IS OVER THE EAST HALF OF THE FCST
AREA TONIGHT...ALONG WITH THE LIGHTEST WINDS...WITH LOWS TONIGHT
FALLING INTO THE 30S...COLDEST ALONG/NORTHEAST OF I-94. CONTINUED
MENTION OF FROST OVER MAINLY THE EAST 2/3 OF THE FCST AREA TONIGHT.
WILL LEAVE ANY POTENTIAL FROST HEADLINES TONIGHT TO DAY CREW WHO CAN
MONITOR TEMPS/DEWPOINT/WIND TRENDS THRU THE EARLY AFTERNOON HOURS.
HIGH CONTINUES TO MOVE OFF THU WITH INCREASING SOUTHEAST WINDS
BETWEEN IT AND THE NEXT LOW/TROUGH INTO THE CENTRAL/NORTHERN PLAINS.
MID/HIGH LEVEL MOISTURE AHEAD OF THIS TROUGH SPREADS EAST ACROSS
THE AREA THU WITH THE INCREASE OF LOWER LEVEL MOISTURE REACHING THE
WEST END OF THE FCST AREA EITHER LATE THU AFTERNOON OR THU EVENING.
DEEPER/STRONGER OF THE FORCING FROM 925-850MB WARM/MOISTURE
ADVECTION/ISENTROPIC LIFT THRU PV ADVECTION/DIVERGENCE ALOFT AHEAD
OF THE SHORTWAVE MOVE INTO/ACROSS THE AREA THU NIGHT. ADDED A SMALL
-SHRA CHANCE TO THE WEST END OF THE FCST AREA LATE THU AFTERNOON TO
BLEND WITH NEIGHBORING GRIDS. RAISED RAIN CHANCES BY LATE THU NIGHT
TOWARD 80 PERCENT WITH EVEN THE LOOSE MODEL CONSENSUS ALL PRODUCING
SOME PRECIP OVER THE AREA. LEANING TOWARD THE SLOWER ECMWF/GEM FOR
FRI...CONTINUED 20-50 PERCENT RAIN CHANCES...HIGHEST EAST...OVER THE
FCST AREA FRI MORNING. CAPE LOOKS TO REMAIN LIMITED THU NIGHT/FRI
MORNING. GIVEN THE STRENGTH/DEPTH OF THE FORCING/LIFT AND MODEL
SOUNDINGS SHOWING NEAR NEUTRAL STABILITY ABOVE 850MB CONTINUED
MENTION OF ISOLATED OR SCT TSRA IN THE LATE THU AFTERNOON THRU FRI
MORNING PERIODS. WEAK SFC-500MB RIDGING BUILDS ACROSS THE AREA FOR
LATER FRI/FRI NIGHT. LEANING TOWARD THE SLOWER ECMWF/GEM...ANY
RETURNING LOWER LEVEL MOISTURE TRANSPORT/WARM ADVECTION WOULD REMAIN
WEST OF THE FCST AREA FRI NIGHT AND REMOVED THE SMALL -SHRA/TSRA
CHANCE.
WITH PLENTY OF SUNSHINE TODAY...AT LEAST OVER THE CENTRAL/SOUTH
PARTS OF THE FCST AREA...FAVORED WARMER OF THE GUIDANCE HIGHS. WITH
THE COOL/DRY AIRMASS OVER THE AREA...FAVORED COOLER OF GUIDANCE
LOWS TONIGHT. GUIDANCE HIGHS SIMILAR AND LOOK REASONABLE FOR THU.
WITH THICKER CLOUDS/-SHRA...FAVORED WARMER OF GUIDANCE LOWS THU
NIGHT. WITH TIMING UNCERTAINTIES...USED A BLEND OF GUIDANCE HIGHS/
LOWS FOR FRI/FRI NIGHT.
.LONG TERM...SATURDAY THROUGH TUESDAY
356 AM CDT WED MAR 28 2012
SOME IMPROVEMENT OF CONSISTENCY AMONG 28.00Z MODEL RUNS FOR SAT INTO
SUN...BUT BETWEEN MODEL AND RUN-TO-RUN CONSISTENCY CONTINUES TO
LEAVE A LOT TO BE DESIRED BY SUN NIGHT AND FOR EARLY NEXT WEEK.
AVERAGE CONFIDENCE SAT INTO SUN WITH IMPROVING MODEL CONSENSUS
INDICATING SHORTWAVE RIDGING ALOFT CROSSING THE UPPER MIDWEST.
WEEKEND TRENDING TO BE DRY OR ONLY VERY SMALL -SHRA/TSRA CHANCES AND
A WARMING PERIOD WITH THE RIDGING/RISING HGTS AND PERSISTENT LOW
LEVEL WARM ADVECTION OVER THE REGION. WITH THE VERY LOW CONSISTENCY
AMONG THE MODELS BY MON/TUE...FCST CONFIDENCE THESE PERIODS QUITE
LOW AS WELL. SOME SIGNAL AMONG ALL MODELS FOR TROUGHING TO MOVE
INTO/ACROSS THE UPPER MIDWEST IN THE MON/TUE TIMEFRAME BUT DETAIL
DIFFERENCE QUITE LARGE. ONE OF THE MOST EXTREME SOLUTIONS FOR EARLY
NEXT WEEK IS THE UKMET...WITH A LARGE NEGATIVE TILT CENTRAL CONUS
TROUGH AND A 984MB SFC LOW NEAR KDBQ MON EVENING. IMPLICATIONS FOR
THIS WOULD NOT GO WELL WITH OUR WARM/EARLY START TO SPRING. WITH LOW
CONFIDENCE AND ALL THE MODEL SPREAD STAYED NEAR THE MODEL/ENSEMBLE
CONSENSUS FOR DAYS 6/7. DID RAISE HIGHS A BIT SUNDAY WITH STRONG
RIDGING/WARMING AHEAD OF ANY TROUGHING/SFC LOW FOR EARLY NEXT WEEK.
&&
.AVIATION...THROUGH 18Z THURSDAY
1236 PM CDT WED MAR 28 2012
MAIN AVIATION FORECAST CONCERNS IS LOW PRESSURE OVER THE GREAT LAKES
REGION WRAPPING STRATOCUMULUS CLOUD DECK INTO THE REGION THIS
AFTERNOON AND INTO THE EARLY EVENING HOURS. CEILING HEIGHTS WITHIN
THE STRATOCUMULUS DECK ARE IN THE MVFR RANGE OF 2000 TO 3500 FEET.
THE COMBINATION OF ABUNDANT SUNSHINE AHEAD OF THE DECK OF CLOUDS
AND SURFACE HIGH PRESSURE BUILDING INTO THE AREA FROM THE NORTHERN
PLAINS...STRATOCUMULUS DECK IS SLOWLY ERODING ON SOUTHERN FLANK
PER LATEST VISIBLE SATELLITE IMAGERY. LATEST 28.15Z RUC AND 28.12Z
NAM SHOW STRATOCUMULUS DECK TO HOLD TOGETHER BEFORE ERODING LATE
THIS AFTERNOON AND EARLY EVENING HOURS PER RELATIVE HUMIDITY
FIELDS AT 850MB AND 925MB. FOR NOW...HAVE INTRODUCED BROKEN LAYER
AT MVFR CONDITIONS AT KRST AND ADDED A TEMPO GROUP OF SCATTERED
CLOUDS THROUGH 22Z WEDNESDAY. AT KLSE...CEILINGS HEIGHTS SHOULD BE
ABOVE 3000 FEET AND IN THE VFR RANGE. NEXT AVIATION CONCERN IS
APPROACHING COLD FRONT FOR THURSDAY. LATEST DETERMINISTIC 28.12Z
MODELS SHOW PRESSURE GRADIENT TIGHTENING AND WIND DIRECTION
SHIFTING TO SOUTHEAST AFTER 13Z THURSDAY. SUSTAIN WIND SPEEDS ARE
EXPECTED TO BE AROUND 15 KNOTS AND GUST UP TO AROUND 20
KNOTS...ESPECIALLY AT KRST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
356 AM CDT WED MAR 28 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...DTJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
356 AM CDT WED MAR 28 2012
.SHORT TERM...
356 AM CDT WED MAR 28 2012
FORECAST CONCERNS THIS PACKAGE...FROST POTENTIAL TONIGHT...RAIN
CHANCES CENTERED ON THU NIGHT...TEMPERATURES.
DATA ANALYSIS AT 06Z HAD A BROAD AREA OF LOW PRESSURE CENTERED JUST
NORTH OF LK SUPERIOR. PRESSURE GRADIENT AROUND THIS LOW STILL
EXTENDED ACROSS MN/WI/MUCH OF IA AND CONTINUED TO RELAX EARLY
THIS MORNING. WINDS ACROSS MOST OF MN/WI REMAINED IN THE 10-20KT
RANGE. CLOUDS IN THE CIRCULATION AROUND THE LOW COVERED CENTRAL/
NORTHERN MN AND WI NORTH OF HWY 29...WITH GENERALLY CLEAR SKIES
ELSEWHERE ACROSS THE UPPER MIDWEST. TEMPS ACROSS THE REGION COOLING
IN THE WEST/NORTHWEST FLOW BUT REMAINED WELL ABOVE NORMAL.
28.00Z MODELS INITIALIZED WELL. SOLUTIONS QUITE SIMILAR FOR TODAY
THRU THU THEN DIVERGE WITH THE STRENGTH/TIMING OF THE SHORTWAVE AND
SFC LOW/TROUGH TO MOVE ACROSS THE MID/UPPER MS VALLEY THU NIGHT.
DPROG/DT OF 500MB HGTS AT 28.00Z SHOWED THE RUNS OF 26.00Z AND
27.00Z VERIFIED WELL ACROSS NOAM/EASTERN PAC WITH BETTER RUN-TO-RUN
CONSISTENCY BY ECMWF. MODELS CONVERGING TOWARD A TIGHTER CONSENSUS
THRU THU AS THE NEXT SHORTWAVE ENERGY FROM THE PACIFIC MOVES INTO
THE CENTRAL/NORTHERN PLAINS BY 00Z FRI. FROM THERE MODELS DIVERGE
WITH THE EVOLUTION OF THIS TROUGH AS IT MOVES EAST THRU THE REGION
THU NIGHT/FRI. SOMEWHAT BETTER RUN-TO-RUN CONSISTENCY BY ECMWF THU
NIGHT THRU FRI NIGHT...BUT COULD BE BETTER. CHECK OF OBS VS. MODEL
DATA AT 06Z SHOWED MODELS ON TRACK WITH THE SFC FEATURES OVER
CENTRAL NOAM. PER WV IMAGERY...ECMWF/GEM LOOKED BETTER THAN
NAM/GFS/MET WITH THE SHORTWAVE ENERGY IN THE TROUGH APPROACHING THE
WEST COAST. ECMWF/GEM ARE A COUPLE OF THE SLOWER SOLUTIONS WITH THIS
ENERGY AS IT CROSSES THE MID/UPPER MS VALLEY THU NIGHT/FRI. WITH
ECMWF/GEM LOOKING BETTER AT 06Z...FAVORED A MODEL/ENSEMBLE CONSENSUS
WEIGHTED TOWARD THEM ESPECIALLY THU NIGHT/FRI. HOWEVER GIVEN THE
MODEL SPREAD FCST CONFIDENCE FALLS TO AVERAGE FOR THU NIGHT THRU FRI
NIGHT.
FOR THE SHORT TERM...THE LOW NORTH OF LK SUPERIOR MOVES QUICKLY AWAY
FROM THE REGION TODAY. HOWEVER MDT 925 PRESSURE GRADIENT/WINDS
REMAIN OVER THE AREA MUCH OF THE DAY. WITH PLENTY OF SUNSHINE AND
MODEL SOUNDINGS INDICATING MIXING TO AROUND 900MB...WINDS WILL
REMAIN BRISK/BREEZY TODAY. SFC RIDGE AXIS DRIFTS RATHER QUICKLY EAST
ACROSS THE AREA TONIGHT...AND IS OVER EASTERN WI BY 12Z THU. WINDS
BECOME LIGHT THIS EVENING BUT APPEARS WINDS MAY STIR/INCREASE A BIT
LATE TONIGHT...ESPECIALLY OVER THE WEST HALF OF THE FCST AREA.
COLDEST OF THE LOW LEVEL AIRMASS IS OVER THE EAST HALF OF THE FCST
AREA TONIGHT...ALONG WITH THE LIGHTEST WINDS...WITH LOWS TONIGHT
FALLING INTO THE 30S...COLDEST ALONG/NORTHEAST OF I-94. CONTINUED
MENTION OF FROST OVER MAINLY THE EAST 2/3 OF THE FCST AREA TONIGHT.
WILL LEAVE ANY POTENTIAL FROST HEADLINES TONIGHT TO DAY CREW WHO CAN
MONITOR TEMPS/DEWPOINT/WIND TRENDS THRU THE EARLY AFTERNOON HOURS.
HIGH CONTINUES TO MOVE OFF THU WITH INCREASING SOUTHEAST WINDS
BETWEEN IT AND THE NEXT LOW/TROUGH INTO THE CENTRAL/NORTHERN PLAINS.
MID/HIGH LEVEL MOISTURE AHEAD OF THIS TROUGH SPREADS EAST ACROSS
THE AREA THU WITH THE INCREASE OF LOWER LEVEL MOISTURE REACHING THE
WEST END OF THE FCST AREA EITHER LATE THU AFTERNOON OR THU EVENING.
DEEPER/STRONGER OF THE FORCING FROM 925-850MB WARM/MOISTURE
ADVECTION/ISENTROPIC LIFT THRU PV ADVECTION/DIVERGENCE ALOFT AHEAD
OF THE SHORTWAVE MOVE INTO/ACROSS THE AREA THU NIGHT. ADDED A SMALL
-SHRA CHANCE TO THE WEST END OF THE FCST AREA LATE THU AFTERNOON TO
BLEND WITH NEIGHBORING GRIDS. RAISED RAIN CHANCES BY LATE THU NIGHT
TOWARD 80 PERCENT WITH EVEN THE LOOSE MODEL CONSENSUS ALL PRODUCING
SOME PRECIP OVER THE AREA. LEANING TOWARD THE SLOWER ECMWF/GEM FOR
FRI...CONTINUED 20-50 PERCENT RAIN CHANCES...HIGHEST EAST...OVER THE
FCST AREA FRI MORNING. CAPE LOOKS TO REMAIN LIMITED THU NIGHT/FRI
MORNING. GIVEN THE STRENGTH/DEPTH OF THE FORCING/LIFT AND MODEL
SOUNDINGS SHOWING NEAR NEUTRAL STABILITY ABOVE 850MB CONTINUED
MENTION OF ISOLATED OR SCT TSRA IN THE LATE THU AFTERNOON THRU FRI
MORNING PERIODS. WEAK SFC-500MB RIDGING BUILDS ACROSS THE AREA FOR
LATER FRI/FRI NIGHT. LEANING TOWARD THE SLOWER ECMWF/GEM...ANY
RETURNING LOWER LEVEL MOISTURE TRANSPORT/WARM ADVECTION WOULD REMAIN
WEST OF THE FCST AREA FRI NIGHT AND REMOVED THE SMALL -SHRA/TSRA
CHANCE.
WITH PLENTY OF SUNSHINE TODAY...AT LEAST OVER THE CENTRAL/SOUTH
PARTS OF THE FCST AREA...FAVORED WARMER OF THE GUIDANCE HIGHS. WITH
THE COOL/DRY AIRMASS OVER THE AREA...FAVORED COOLER OF GUIDANCE
LOWS TONIGHT. GUIDANCE HIGHS SIMILAR AND LOOK REASONABLE FOR THU.
WITH THICKER CLOUDS/-SHRA...FAVORED WARMER OF GUIDANCE LOWS THU
NIGHT. WITH TIMING UNCERTAINTIES...USED A BLEND OF GUIDANCE HIGHS/
LOWS FOR FRI/FRI NIGHT.
.LONG TERM...SATURDAY THROUGH TUESDAY
356 AM CDT WED MAR 28 2012
SOME IMPROVEMENT OF CONSISTENCY AMONG 28.00Z MODEL RUNS FOR SAT INTO
SUN...BUT BETWEEN MODEL AND RUN-TO-RUN CONSISTENCY CONTINUES TO
LEAVE A LOT TO BE DESIRED BY SUN NIGHT AND FOR EARLY NEXT WEEK.
AVERAGE CONFIDENCE SAT INTO SUN WITH IMPROVING MODEL CONSENSUS
INDICATING SHORTWAVE RIDGING ALOFT CROSSING THE UPPER MIDWEST.
WEEKEND TRENDING TO BE DRY OR ONLY VERY SMALL -SHRA/TSRA CHANCES AND
A WARMING PERIOD WITH THE RIDGING/RISING HGTS AND PERSISTENT LOW
LEVEL WARM ADVECTION OVER THE REGION. WITH THE VERY LOW CONSISTENCY
AMONG THE MODELS BY MON/TUE...FCST CONFIDENCE THESE PERIODS QUITE
LOW AS WELL. SOME SIGNAL AMONG ALL MODELS FOR TROUGHING TO MOVE
INTO/ACROSS THE UPPER MIDWEST IN THE MON/TUE TIMEFRAME BUT DETAIL
DIFFERENCE QUITE LARGE. ONE OF THE MOST EXTREME SOLUTIONS FOR EARLY
NEXT WEEK IS THE UKMET...WITH A LARGE NEGATIVE TILT CENTRAL CONUS
TROUGH AND A 984MB SFC LOW NEAR KDBQ MON EVENING. IMPLICATIONS FOR
THIS WOULD NOT GO WELL WITH OUR WARM/EARLY START TO SPRING. WITH LOW
CONFIDENCE AND ALL THE MODEL SPREAD STAYED NEAR THE MODEL/ENSEMBLE
CONSENSUS FOR DAYS 6/7. DID RAISE HIGHS A BIT SUNDAY WITH STRONG
RIDGING/WARMING AHEAD OF ANY TROUGHING/SFC LOW FOR EARLY NEXT WEEK.
&&
.AVIATION...THROUGH 06Z THURSDAY
1150 PM CDT TUE MAR 27 2012
SOME WEAK PRESSURE RISES HAVE KEPT SOME GUSTINESS AT THE TAF SITES
THIS PAST EVENING. THESE GUSTS SHOULD DIMINISH AS THE NIGHT WEARS
ON WITH A RELAXING PRESSURE GRADIENT. 29.02Z RUC BUFKIT SOUNDINGS
CONTINUE TO HINT AT THE POSSIBILITY OF A BROKEN CEILING AROUND
030K FEET AFTER 08Z. HOWEVER...28.00Z NAM LESS ROBUST WITH THIS
MOISTURE AND GIVEN SATELLITE TRENDS WITH CLOUDS REMAINING NORTH OF
THE TAF SITES...JUST WENT WITH A SCATTERED DECK OF CLOUDS AFTER
08Z. AFTER 14Z SOUNDINGS INDICATE MIXING AND COULD SEE SOME GUSTS
TO BETWEEN 20 TO 23 KNOTS FOR A FEW HOURS. HIGH PRESSURE THEN
BUILDS IN LATE WEDNESDAY AFTERNOON...WITH CLEAR SKIES AND LIGHT
WINDS AFTER 01Z.650 PM CDT TUE MAR 27 2012
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
356 AM CDT WED MAR 28 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION.....RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1150 PM CDT TUE MAR 27 2012
.SHORT TERM...
650 PM CDT TUE MAR 27 2012
WILL ALLOW WIND ADVISORY TO EXPIRE AT 7 PM. WINDS WILL CONTINUE
TO DIMINISH EARLY THIS EVENING AS THE PRESSURE GRADIENT SLACKENS.
UPDATED PRODUCTS WILL BE OUT SHORTLY.
.LONG TERM...SATURDAY THROUGH TUESDAY
250 PM CDT TUE MAR 27 2012
CONSIDERABLE MODEL DIFFERENCES FOR THE WEEKEND INTO EARLY NEXT WEEK.
THE GFS FAVORS A CLOSED LOW AND LARGE TROUGH OVER THE ROCKIES WHILE
THE EC IS WEAKER AND MORE PROGRESSIVE WITH THIS FEATURE. THUS...THE
GFS WOULD HANG ONTO A RIDGE FOR MUCH OF THE EXTENDED PERIOD WHILE
THE EC WOULD BRING IN PCPN CHANCES MON-TUE. A LOT OF INCONSISTENCIES
WITHIN THE MODELS TOO...ESPECIALLY THE EC. WILL LEAN ON THE A
GFS/CONSENSUS SOLUTION FOR THE DETAILS. THE WEEKEND IS SHAPING UP
DRY THOUGH...AND WITH A RIDGE MORE LIKELY...HIGHS COULD POP BACK UP
INTO THE 70S SUNDAY.
&&
.AVIATION...THROUGH 06Z THURSDAY
1150 PM CDT TUE MAR 27 2012
SOME WEAK PRESSURE RISES HAVE KEPT SOME GUSTINESS AT THE TAF SITES
THIS PAST EVENING. THESE GUSTS SHOULD DIMINISH AS THE NIGHT WEARS
ON WITH A RELAXING PRESSURE GRADIENT. 29.02Z RUC BUFKIT SOUNDINGS
CONTINUE TO HINT AT THE POSSIBILITY OF A BROKEN CEILING AROUND
030K FEET AFTER 08Z. HOWEVER...28.00Z NAM LESS ROBUST WITH THIS
MOISTURE AND GIVEN SATELLITE TRENDS WITH CLOUDS REMAINING NORTH OF
THE TAF SITES...JUST WENT WITH A SCATTERED DECK OF CLOUDS AFTER
08Z. AFTER 14Z SOUNDINGS INDICATE MIXING AND COULD SEE SOME GUSTS
TO BETWEEN 20 TO 23 KNOTS FOR A FEW HOURS. HIGH PRESSURE THEN
BUILDS IN LATE WEDNESDAY AFTERNOON...WITH CLEAR SKIES AND LIGHT
WINDS AFTER 01Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
650 PM CDT TUE MAR 27 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RABERDING
LONG TERM......RIECK
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
433 AM EDT FRI MAR 30 2012
.UPDATE...
AVIATION SECTION HAS BEEN UDPATED BELOW.
&&
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE EAST ACROSS CENTRAL INDIANA WHICH
WILL RESULT IN NUMEROUS THUNDERSTORMS FROM TONIGHT THROUGH FRIDAY
EVENING. SOME OF THESE COULD BE SEVERE WITH DAMAGING WINDS AND HAIL
FRIDAY AFTERNOON AND EVENING. SATURDAY IS EXPECTED TO BE DRY...AND
THEN THUNDERSTORM CHANCES WILL RETURN SATURDAY NIGHT AS A WARM FRONT
LIFTS NORTHEAST ACROSS CENTRAL INDIANA ON SUNDAY FOLLOWED BY A COLD
FRONT ON TUESDAY.
&&
.NEAR TERM /REST OF TONIGHT/...
AREA OF SHOWERS ASSOCIATED WITH WEAK ENERGY ALOFT WILL CONTINUE TO
PUSH ACROSS THE FORECAST AREA THE NEXT FEW HOURS. THUS WILL KEEP LOW
POPS FOR SHOWERS THROUGH THEN. OVERNIGHT...ISENTROPIC LIFT WILL
CONTINUE AHEAD OF A WARM FRONT. HOWEVER LIFT IS NOT IMPRESSIVE...AND
LATEST HRRR MODEL SHOWS VERY LITTLE CONVECTION OVERNIGHT.
THINK THAT THE HRRR MAY BE A BIT UNDERDONE...BUT STILL THE TREND IS
FOR LOWER COVERAGE THAN PREVIOUSLY THOUGHT. THUS HAVE LOWERED POPS
OUT OF THE LIKELY CATEGORY NORTHWEST AND NUDGED DOWN ELSEWHERE.
LOW TEMPERATURES STILL LOOK OK...SO ONLY ADJUSTED HOURLY TRENDS.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
BASED ON LATEST TRENDS AND LATEST MODEL DATA...FEEL THAT POPS DURING
FRIDAY MORNING WILL BE LOWER THAN WAS PREVIOUSLY FORECAST. THUS
LOWERED POPS TO CHANCE CATEGORY FOR MUCH OF THE MORNING. LIKELY
STILL LOOKS GOOD WITH THE COLD FRONT IN THE AFTERNOON.
PREVIOUS DISCUSSION FROM THURSDAY AFTERNOON FOLLOWS...
MAIN CHALLENGE TO THE FORECAST WILL BE POSSIBILITY OF SEVERE WEATHER
ACROSS THE FORECAST AREA FRIDAY AFTERNOON AND EVENING WITH SPC DAY2
SLIGHT RISK FOR DAMAGING WINDS AND LARGE HAIL ACROSS ALL OF CENTRAL
INDIANA. MODELS IN FAIR AGREEMENT ON MOVING SURFACE LOW PRESSURE
CENTER JUST NORTH OF OUT NORTHERN COUNTIES ON FRIDAY AFTERNOON WITH
A COLD FRONT SLIDING SOUTHEAST TO NEAR THE OHIO RIVER FRIDAY
EVENING. IN ADDITION...A DECENT UPPER SHORT WAVE WILL MOVE ACROSS
DURING THE AFTERNOON IN THE FAST WESTERLY UPPER FLOW. IN
ADDITION...MODEL MIXED LAYER CAPES WILL REACH 1000-1500 J/KG WITH
THE HIGHER AMOUNTS ACROSS OUR SOUTH. WILL GO WITH LIKELY AFTERNOON
POPS WITH PLENTY OF LIFT AND INSTABILITY AND CHANCES POPS LINGERING
INTO THE EVENING. DECENT 35 KNOT DEEP LAYER UNIDIRECTIONAL SHEAR
ALONG WITH THE INSTABILITY SUGGESTS SLIGHT RISK LOOKS OK WITH LINEAR
UPWARD VERTICAL MOTION FIELD SUGGESTING A SQUALL LINE LOOKS VERY
POSSIBLE WITH PROPAGATION NORTHWEST TO SOUTHEAST. RIDGING AND A
DRYING COLUMN SHOULD ALLOW INCREASING SUNSHINE ON SATURDAY.
FINALLY...A WARM FRONT WILL LIFT NORTHEAST INTO CENTRAL INDIANA
SATURDAY NIGHT AND SUNDAY AND SHOULD COMBINE WITH INSTABILITY FOR
ANOTHER ROUND OF THUNDERSTORMS.
WITH MODELS FAR APART IN TEMPERATURES...CONFIDENCE NOT GREAT AND
THUS WENT WITH A COMBO OF A BLEND ALONG WITH TRYING TO MATCH UP WITH
ADJACENT OFFICES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ON MONDAY AN UPPER RIDGE WILL BE ACROSS OUR REGION WHILE A BROAD
UPPER TROUGH WILL EXTEND FROM CENTRAL CANADA TO NEAR NEW MEXICO.
ACTUALLY THESE CONSISTS OF TWO SYSTEMS EACH BEING CLOSED UPPER LOWS
ONE OVER CENTRAL CANADA AND THE OTHER OVER THE SOUTHWEST U.S. BOTH
OF THESE GRADUALLY MOVE TO THE EAST WITH THE CLOSED UPPER LOW MOVING
INTO THE DEEP SOUTH AND THE NORTHERN SYSTEM MOVING EAST ACROSS
SOUTHERN CANADA.
THIS ALLOWS A COLD FRONT TO MOVE INTO OUR REGION BY EARLY THURSDAY
AND THEN STALL ACROSS THE SOUTH BY MIDWEEK AS HIGH PRESSURE BUILDS
IN FROM THE NORTHWEST.
ONLY SIGNIFICANT CHANGES MADE TO ALL BLEND WAS TO GO CLOSER TO
WARMER CONSALL TEMPERATURES MONDAY AND MONDAY NIGHT WITH WARM
ADVECTION ACROSS OUR REGION. ON WEDNESDAY NIGHT I LOWERED
TEMPERATURES A LITTLE AS MODELS SEEM TO BE A BIT TOO WARM THIS RUN
AS SKIES WILL BE MOSTLY CLEAR ALLOWING FOR STRONG RADIATIONAL
COOLING.
&&
.AVIATION /DISCUSSION FOR 300900Z KIND TAF UPDATE/...
RADAR INDICATEES SCATTERED SHOWERS ADN A FEW SHOWERS WILL PASS NEAR
OR JUST NORTH OF KIND. HAVE UPDATED TO ADD TEMPO THUNDER FOR NEXT
FEW HOURS. NO OTHER CHANGES NEEDED AT THIS TIME. PREVIOUS AVIATION
DISCUSSION FOLLOWS...
VFR CONDITIONS EXPECTED THROUGH MIDDAY. IFR CONDITIONS POSSIBLE
WITHIN CONVECTION DURING THE AFTERNOON...THEN MVFR CEILINGS THIS
EVENING.
WARM FRONT APPROACHING EARLY THIS MORNING BUT WITH LIMITED FORCING
PRESENT...CONVECTION LIKELY TO REMAIN ISOLATED AT BEST. SKIES MAY
CLEAR FOR A BRIEF PERIOD BEFORE MID LEVEL CLOUDS ASSOCIATED WITH THE
CONVECTIVE COMPLEX OVER IOWA SPREAD BACK INTO THE REGION. WINDS WILL
VEER TO S/SW AND BECOMING GUSTY BY MIDDAY AS THE WARM FRONT LIFTS
NORTH THROUGH THE REGION.
AS LOW PRESSURE AND AN ASSOCIATED COLD FRONT TRACKS INTO WESTERN
INDIANA DURING THE AFTERNOON...CONVECTION EXPECTED TO DEVELOP AND
SWEEP ACROSS THE FORECAST AREA THROUGH EARLY EVENING. HIGHEST
CONFIDENCE IN CONVECTIVE IMPACTS TO TERMINALS AFTER 17-18Z AND WILL
CONTINUE WITH VCTS AT ALL SITES. POTENTIAL EXISTS FOR BRIEF DROPS TO
IFR CONDITIONS WITHIN HEAVIER OR LOCALLY SEVERE CONVECTION. WINDS
WILL SHIFT TO NORTHWEST BEHIND THE FRONT DURING THE EVENING WITH
MODEL SOUNDINGS STRONGLY SUGGESTIVE OF THE DEVELOPMENT OF MVFR
STRATOCU DURING THE EVENING AS MOISTURE BECOMES TRAPPED UNDERNEATH A
LOW LEVEL INVERSION.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK/50
SHORT TERM...MK/50
LONG TERM....JEH
AVIATION...RYAN/JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
317 AM EDT FRI MAR 30 2012
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE EAST ACROSS CENTRAL INDIANA WHICH
WILL RESULT IN NUMEROUS THUNDERSTORMS FROM TONIGHT THROUGH FRIDAY
EVENING. SOME OF THESE COULD BE SEVERE WITH DAMAGING WINDS AND HAIL
FRIDAY AFTERNOON AND EVENING. SATURDAY IS EXPECTED TO BE DRY...AND
THEN THUNDERSTORM CHANCES WILL RETURN SATURDAY NIGHT AS A WARM FRONT
LIFTS NORTHEAST ACROSS CENTRAL INDIANA ON SUNDAY FOLLOWED BY A COLD
FRONT ON TUESDAY.
&&
.NEAR TERM /REST OF TONIGHT/...
AREA OF SHOWERS ASSOCIATED WITH WEAK ENERGY ALOFT WILL CONTINUE TO
PUSH ACROSS THE FORECAST AREA THE NEXT FEW HOURS. THUS WILL KEEP LOW
POPS FOR SHOWERS THROUGH THEN. OVERNIGHT...ISENTROPIC LIFT WILL
CONTINUE AHEAD OF A WARM FRONT. HOWEVER LIFT IS NOT IMPRESSIVE...AND
LATEST HRRR MODEL SHOWS VERY LITTLE CONVECTION OVERNIGHT.
THINK THAT THE HRRR MAY BE A BIT UNDERDONE...BUT STILL THE TREND IS
FOR LOWER COVERAGE THAN PREVIOUSLY THOUGHT. THUS HAVE LOWERED POPS
OUT OF THE LIKELY CATEGORY NORTHWEST AND NUDGED DOWN ELSEWHERE.
LOW TEMPERATURES STILL LOOK OK...SO ONLY ADJUSTED HOURLY TRENDS.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
BASED ON LATEST TRENDS AND LATEST MODEL DATA...FEEL THAT POPS DURING
FRIDAY MORNING WILL BE LOWER THAN WAS PREVIOUSLY FORECAST. THUS
LOWERED POPS TO CHANCE CATEGORY FOR MUCH OF THE MORNING. LIKELY
STILL LOOKS GOOD WITH THE COLD FRONT IN THE AFTERNOON.
PREVIOUS DISCUSSION FROM THURSDAY AFTERNOON FOLLOWS...
MAIN CHALLENGE TO THE FORECAST WILL BE POSSIBILITY OF SEVERE WEATHER
ACROSS THE FORECAST AREA FRIDAY AFTERNOON AND EVENING WITH SPC DAY2
SLIGHT RISK FOR DAMAGING WINDS AND LARGE HAIL ACROSS ALL OF CENTRAL
INDIANA. MODELS IN FAIR AGREEMENT ON MOVING SURFACE LOW PRESSURE
CENTER JUST NORTH OF OUT NORTHERN COUNTIES ON FRIDAY AFTERNOON WITH
A COLD FRONT SLIDING SOUTHEAST TO NEAR THE OHIO RIVER FRIDAY
EVENING. IN ADDITION...A DECENT UPPER SHORT WAVE WILL MOVE ACROSS
DURING THE AFTERNOON IN THE FAST WESTERLY UPPER FLOW. IN
ADDITION...MODEL MIXED LAYER CAPES WILL REACH 1000-1500 J/KG WITH
THE HIGHER AMOUNTS ACROSS OUR SOUTH. WILL GO WITH LIKELY AFTERNOON
POPS WITH PLENTY OF LIFT AND INSTABILITY AND CHANCES POPS LINGERING
INTO THE EVENING. DECENT 35 KNOT DEEP LAYER UNIDIRECTIONAL SHEAR
ALONG WITH THE INSTABILITY SUGGESTS SLIGHT RISK LOOKS OK WITH LINEAR
UPWARD VERTICAL MOTION FIELD SUGGESTING A SQUALL LINE LOOKS VERY
POSSIBLE WITH PROPAGATION NORTHWEST TO SOUTHEAST. RIDGING AND A
DRYING COLUMN SHOULD ALLOW INCREASING SUNSHINE ON SATURDAY.
FINALLY...A WARM FRONT WILL LIFT NORTHEAST INTO CENTRAL INDIANA
SATURDAY NIGHT AND SUNDAY AND SHOULD COMBINE WITH INSTABILITY FOR
ANOTHER ROUND OF THUNDERSTORMS.
WITH MODELS FAR APART IN TEMPERATURES...CONFIDENCE NOT GREAT AND
THUS WENT WITH A COMBO OF A BLEND ALONG WITH TRYING TO MATCH UP WITH
ADJACENT OFFICES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ON MONDAY AN UPPER RIDGE WILL BE ACROSS OUR REGION WHILE A BROAD
UPPER TROUGH WILL EXTEND FROM CENTRAL CANADA TO NEAR NEW MEXICO.
ACTUALLY THESE CONSISTS OF TWO SYSTEMS EACH BEING CLOSED UPPER LOWS
ONE OVER CENTRAL CANADA AND THE OTHER OVER THE SOUTHWEST U.S. BOTH
OF THESE GRADUALLY MOVE TO THE EAST WITH THE CLOSED UPPER LOW MOVING
INTO THE DEEP SOUTH AND THE NORTHERN SYSTEM MOVING EAST ACROSS
SOUTHERN CANADA.
THIS ALLOWS A COLD FRONT TO MOVE INTO OUR REGION BY EARLY THURSDAY
AND THEN STALL ACROSS THE SOUTH BY MIDWEEK AS HIGH PRESSURE BUILDS
IN FROM THE NORTHWEST.
ONLY SIGNIFICANT CHANGES MADE TO ALL BLEND WAS TO GO CLOSER TO WARMER
CONSALL TEMPERATURES MONDAY AND MONDAY NIGHT WITH WARM ADVECTION
ACROSS OUR REGION. ON WEDNESDAY NIGHT I LOWERED TEMPERATURES A
LITTLE AS MODELS SEEM TO BE A BIT TOO WARM THIS RUN AS SKIES WILL BE
MOSTLY CLEAR ALLOWING FOR STRONG RADIATIONAL COOLING.
&&
.AVIATION /DISCUSSION FOR 300600Z TAF ISSUANCE/...
VFR CONDITIONS EXPECTED THROUGH MIDDAY. IFR CONDITIONS POSSIBLE
WITHIN CONVECTION DURING THE AFTERNOON...THEN MVFR CEILINGS THIS
EVENING.
WARM FRONT APPROACHING EARLY THIS MORNING BUT WITH LIMITED FORCING
PRESENT...CONVECTION LIKELY TO REMAIN ISOLATED AT BEST. SKIES MAY
CLEAR FOR A BRIEF PERIOD BEFORE MID LEVEL CLOUDS ASSOCIATED WITH THE
CONVECTIVE COMPLEX OVER IOWA SPREAD BACK INTO THE REGION. WINDS WILL
VEER TO S/SW AND BECOMING GUSTY BY MIDDAY AS THE WARM FRONT LIFTS
NORTH THROUGH THE REGION.
AS LOW PRESSURE AND AN ASSOCIATED COLD FRONT TRACKS INTO WESTERN
INDIANA DURING THE AFTERNOON...CONVECTION EXPECTED TO DEVELOP AND
SWEEP ACROSS THE FORECAST AREA THROUGH EARLY EVENING. HIGHEST
CONFIDENCE IN CONVECTIVE IMPACTS TO TERMINALS AFTER 17-18Z AND WILL
CONTINUE WITH VCTS AT ALL SITES. POTENTIAL EXISTS FOR BRIEF DROPS TO
IFR CONDITIONS WITHIN HEAVIER OR LOCALLY SEVERE CONVECTION. WINDS
WILL SHIFT TO NORTHWEST BEHIND THE FRONT DURING THE EVENING WITH
MODEL SOUNDINGS STRONGLY SUGGESTIVE OF THE DEVELOPMENT OF MVFR
STRATOCU DURING THE EVENING AS MOISTURE BECOMES TRAPPED UNDERNEATH A
LOW LEVEL INVERSION.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK/50
SHORT TERM...MK/50
LONG TERM....JEH
AVIATION...RYAN/JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1253 AM EDT FRI MAR 30 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE EAST ACROSS CENTRAL INDIANA WHICH
WILL RESULT IN NUMEROUS THUNDERSTORMS FROM TONIGHT THROUGH FRIDAY
EVENING. SOME OF THESE COULD BE SEVERE WITH DAMAGING WINDS AND HAIL
FRIDAY AFTERNOON AND EVENING. SATURDAY IS EXPECTED TO BE DRY...AND
THEN THUNDERSTORM CHANCES WILL RETURN SATURDAY NIGHT AS A WARM FRONT
LIFTS NORTHEAST ACROSS CENTRAL INDIANA ON SUNDAY FOLLOWED BY A COLD
FRONT ON TUESDAY.
&&
.NEAR TERM /REST OF TONIGHT/...
AREA OF SHOWERS ASSOCIATED WITH WEAK ENERGY ALOFT WILL CONTINUE TO
PUSH ACROSS THE FORECAST AREA THE NEXT FEW HOURS. THUS WILL KEEP LOW
POPS FOR SHOWERS THROUGH THEN. OVERNIGHT...ISENTROPIC LIFT WILL
CONTINUE AHEAD OF A WARM FRONT. HOWEVER LIFT IS NOT IMPRESSIVE...AND
LATEST HRRR MODEL SHOWS VERY LITTLE CONVECTION OVERNIGHT.
THINK THAT THE HRRR MAY BE A BIT UNDERDONE...BUT STILL THE TREND IS
FOR LOWER COVERAGE THAN PREVIOUSLY THOUGHT. THUS HAVE LOWERED POPS
OUT OF THE LIKELY CATEGORY NORTHWEST AND NUDGED DOWN ELSEWHERE.
LOW TEMPERATURES STILL LOOK OK...SO ONLY ADJUSTED HOURLY TRENDS.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
BASED ON LATEST TRENDS AND LATEST MODEL DATA...FEEL THAT POPS DURING
FRIDAY MORNING WILL BE LOWER THAN WAS PREVIOUSLY FORECAST. THUS
LOWERED POPS TO CHANCE CATEGORY FOR MUCH OF THE MORNING. LIKELY
STILL LOOKS GOOD WITH THE COLD FRONT IN THE AFTERNOON.
PREVIOUS DISCUSSION FROM THURSDAY AFTERNOON FOLLOWS...
MAIN CHALLENGE TO THE FORECAST WILL BE POSSIBILITY OF SEVERE WEATHER
ACROSS THE FORECAST AREA FRIDAY AFTERNOON AND EVENING WITH SPC DAY2
SLIGHT RISK FOR DAMAGING WINDS AND LARGE HAIL ACROSS ALL OF CENTRAL
INDIANA. MODELS IN FAIR AGREEMENT ON MOVING SURFACE LOW PRESSURE
CENTER JUST NORTH OF OUT NORTHERN COUNTIES ON FRIDAY AFTERNOON WITH
A COLD FRONT SLIDING SOUTHEAST TO NEAR THE OHIO RIVER FRIDAY
EVENING. IN ADDITION...A DECENT UPPER SHORT WAVE WILL MOVE ACROSS
DURING THE AFTERNOON IN THE FAST WESTERLY UPPER FLOW. IN
ADDITION...MODEL MIXED LAYER CAPES WILL REACH 1000-1500 J/KG WITH
THE HIGHER AMOUNTS ACROSS OUR SOUTH. WILL GO WITH LIKELY AFTERNOON
POPS WITH PLENTY OF LIFT AND INSTABILITY AND CHANCES POPS LINGERING
INTO THE EVENING. DECENT 35 KNOT DEEP LAYER UNIDIRECTIONAL SHEAR
ALONG WITH THE INSTABILITY SUGGESTS SLIGHT RISK LOOKS OK WITH LINEAR
UPWARD VERTICAL MOTION FIELD SUGGESTING A SQUALL LINE LOOKS VERY
POSSIBLE WITH PROPAGATION NORTHWEST TO SOUTHEAST. RIDGING AND A
DRYING COLUMN SHOULD ALLOW INCREASING SUNSHINE ON SATURDAY.
FINALLY...A WARM FRONT WILL LIFT NORTHEAST INTO CENTRAL INDIANA
SATURDAY NIGHT AND SUNDAY AND SHOULD COMBINE WITH INSTABILITY FOR
ANOTHER ROUND OF THUNDERSTORMS.
WITH MODELS FAR APART IN TEMPERATURES...CONFIDENCE NOT GREAT AND
THUS WENT WITH A COMBO OF A BLEND ALONG WITH TRYING TO MATCH UP WITH
ADJACENT OFFICES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ENSEMBLES IN GENERAL AGREEMENT IN BRINGING A SYSTEM THAT IS
CURRENTLY PROGGED TO BE MOVING INTO THE WEST COAST OVER THE UPCOMING
WEEKEND ACROSS THE LOCAL AREA DURING THE EARLY TO MIDDLE PARTS OF
NEXT WEEK. THERE ARE DIFFERENCES WITH RESPECT TO TIMING...BUT IT
APPEARS THE BEST CHANCES FOR PRECIPITATION WOULD BE MONDAY NIGHT
INTO TUESDAY. SOME OF THE ENSEMBLES INDICATE RATHER LOW SEA LEVEL
PRESSURES WITH THIS SYSTEM...SO THERE IS POTENTIAL FOR A SIGNIFICANT
SURFACE SYSTEM TO ACCOMPANY THE UPPER TROUGH. WILL GO WITH CHANCE
POPS MONDAY AND TUESDAY. A FEW ENSEMBLES CUT OFF THIS TROUGH OVER
THE MIDWEST BY THE MIDDLE OF NEXT WEEK...BUT THE MAJORITY OF THE
MEMBERS KEEP THIS TROUGH FAIRLY PROGRESSIVE. WILL KEEP NEXT
WEDNESDAY AND THURSDAY DRY FOR NOW.
&&
.AVIATION /DISCUSSION FOR 300600Z TAF ISSUANCE/...
VFR CONDITIONS EXPECTED THROUGH MIDDAY. IFR CONDITIONS POSSIBLE
WITHIN CONVECTION DURING THE AFTERNOON...THEN MVFR CEILINGS THIS
EVENING.
WARM FRONT APPROACHING EARLY THIS MORNING BUT WITH LIMITED FORCING
PRESENT...CONVECTION LIKELY TO REMAIN ISOLATED AT BEST. SKIES MAY
CLEAR FOR A BRIEF PERIOD BEFORE MID LEVEL CLOUDS ASSOCIATED WITH THE
CONVECTIVE COMPLEX OVER IOWA SPREAD BACK INTO THE REGION. WINDS WILL
VEER TO S/SW AND BECOMING GUSTY BY MIDDAY AS THE WARM FRONT LIFTS
NORTH THROUGH THE REGION.
AS LOW PRESSURE AND AN ASSOCIATED COLD FRONT TRACKS INTO WESTERN
INDIANA DURING THE AFTERNOON...CONVECTION EXPECTED TO DEVELOP AND
SWEEP ACROSS THE FORECAST AREA THROUGH EARLY EVENING. HIGHEST
CONFIDENCE IN CONVECTIVE IMPACTS TO TERMINALS AFTER 17-18Z AND WILL
CONTINUE WITH VCTS AT ALL SITES. POTENTIAL EXISTS FOR BRIEF DROPS TO
IFR CONDITIONS WITHIN HEAVIER OR LOCALLY SEVERE CONVECTION. WINDS
WILL SHIFT TO NORTHWEST BEHIND THE FRONT DURING THE EVENING WITH
MODEL SOUNDINGS STRONGLY SUGGESTIVE OF THE DEVELOPMENT OF MVFR
STRATOCU DURING THE EVENING AS MOISTURE BECOMES TRAPPED UNDERNEATH A
LOW LEVEL INVERSION.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK/50
SHORT TERM...MK/50
LONG TERM....JAS
AVIATION...RYAN/JH
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1113 PM CDT THU MAR 29 2012
.UPDATE 30/06Z 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...30/06Z
THUNDER CONTINUES OVER THE EAST AND ANOTHER LINE FORMING IN THE
NORTHWEST WILL MOVE EAST SOUTHEAST THROUGH 11Z. STRONGER STORMS
ACROSS THE SOUTH AND EAST WILL AFFECT KALO...KOTM...THROUGH 10Z WITH
LOWERING CIGS FROM 06Z THROUGH 11Z AS MOIST BOUNDARY LAYER CONTINUES
NEAR SATURATION. HAVE MVFR CIGS/VISBYS WITH SOME CHANCE OF IFR FOR
BRIEF PERIOD NORTH AND EAST. OTHERWISE SOME REDUCTION IN VSBY BY
11-14Z THEN IMPROVING FROM 14Z ONWARD. LIGHT WINDS AND GENERALLY VFR
CIGS EXPECTED FOR THE REMAINDER OF TAF PERIOD. WINDS SWING BACK TO
SOUTHEAST AFT 31/00Z.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...JUNGBLUTH
AVIATION...REV
LONG TERM...SMALL
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
424 AM EDT FRI MAR 30 2012
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 423 AM EDT FRI MAR 30 2012
BROAD AREA OF SHOWERS STRETCHING FROM THE ARROWHEAD OF MN THROUGH
WRN UPPER MI...WRN TWO THIRDS OF WI AND INTO ERN IOWA AT 07Z. OVER
THE ARROWHEAD OF MN AND INTO WRN UPPER MI...SHOWERS HAVE BEEN MAINLY
IN THE FORM OF SNOW. RECENT WEBCAM IMAGES IN IRONWOOD SHOW A DUSTING
OF SNOW ON THE GROUND OVER THE LAST HOUR OR SO. FARTHER SOUTH AND
WEST...STARTING TO SEE A TRANSITION TO RAIN AS THE NOSE OF WARM
AIR AND DRY AIR ALOFT ARE STARTING TO TURN THE PCPN BACK TO RAIN
OVER NW WI. THIS IS ALL RAIN THROUGH THE REST OF WI AND INTO
IOWA...WHERE CONVECTION DEVELOPED DURING THE EVENING AND HAS SPREAD
NE. THE PCPN IS ASSOCIATED WITH A SHORTWAVE MOVING THROUGH THE
CNTRL/NRN PLAINS STATES...WHILE A SFC LOW IS TRACKING THROUGH NRN
MO AND SRN IOWA.
PCPN FOR THIS MORNING IS THE MAIN FEATURE OF CONCERN FOR THE SHORT
TERM FORECAST. THE NRN PART OF THE PCPN AREA IS THE INITIAL AREA OF
CONCERN. THIS SHOULD CONTINUE TO THE E OVER THE NEXT SEVERAL
HOURS...BUT WITH THE MID-LOW LVL DRY AIR IN PLACE...EXPECT THIS TO
EAT AWAY AT THE PCPN AS IT MOVES OUT OF WRN UPPER MI. THIS
DIMINISHING TREND WILL ALSO BE DUE TO THE FORCING FOCUSING FARTHER
S OVER CNTRL WI...ASSOCIATED WITH THE RIGHT REAR OF THE UPPER JET
AND H850-700 WAA. THIS REFOCUSING HAS BEEN SEEN ON RADAR OVER THE
LAST HOUR...WITH SHOWERS BECOMING MORE WIDESPREAD OVER CNTRL/SRN
WI.
THE QUESTION WITH THE SRN AREA OF PCPN WILL BE HOW FAR N IT
WILL TRACK. MODELS CONSISTENT ON THE H925-850 WAA REMAINING OVER THE
SE HALF OF WI AND THE ONLY THING REALLY GOING FOR SOME PCPN FARTHER
TO THE N IS SOME H850-700 FGEN OVER THE SCNTRL. LOOKING AT FGEN
CROSS-SECTIONS OVER THE CWA...THAT AREA IS UNDER THE ASCENDING
BRANCH OF FGEN. OTHERWISE...IT SEEMS LIKE MUCH OF REST OF THE AREA
WILL BE ON THE DESCENDING BRANCH OF THE FGEN. THIS SUPPORTS A
DIMINISHING TREND THE MODELS SHOW WITH THE NRN PCPN AREA AND
THINK THAT LLVL DRY ERLY FLOW WILL COMBINE TO LIMIT THE PCPN FROM
GOING TOO FAR EAST OF A LINE FROM KMQT/KESC. THUS...HAVE DIMINISHED
POPS OVER THE E TO JUST SLIGHTS. FOR THE STRONGER PCPN AREA...00Z
MODEL RUNS...ALONG WITH THE HOURLY RUC RUNS...ALL SHOW THIS STRONGER
PCPN JUST BRUSHING THE SCNTRL CWA AND CORRELATES WELL WITH THE FGEN.
AS FOR PCPN AMNTS...THE DIMINISHING TREND OVER THE N SHOULD KEEP
LIQUID AMNTS LIGHT. ALONG THE WI BORDER...COULD SEE AMNTS IN THE
0.1 TO 0.2 RANGE...WITH THE HIGHEST AMNTS NEAR THE CITY OF
MENOMINEE. 29/21Z SREF SUPPORTS THAT SOLN AND SHOWING BEST CHANCES
OF 0.1IN ALONG THE WI BORDER AND MAINLY NEAR MENOMINEE...SO FEEL
THAT IS THE WAY TO GO. RUC/NAM SOUNDINGS SHOW THE PCPN FALLING AS
SNOW FOR THE FIRST HOUR OR TWO OF PCPN...BUT THEN START
TRANSITIONING TO A -RA/DZ THROUGH THE MORNING HOURS FROM W TO E.
THIS IS DUE TO DRIER AIR ALOFT MOVING INTO THE AREA FROM W TO E
AFTER 12Z. OVER THE FAR WEST...WARMER H875 TEMPS WILL PRODUCE A
QUICKER CHANGE OVER TO RAIN OVER GOGEBIC COUNTY...PROBABLY TOWARDS
DAYBREAK. FORTUNATELY...LLVL TEMPERATURES SHOULD BE WARMING AT THAT
TIME AND LIMIT POTENTIAL FOR FREEZING ON THE SFC. PREVIOUS SHIFT HAD
A GOOD HANDLE ON THIS AND WILL FOLLOW THAT TRANSITION. THUS...SNOW
AMNTS SHOULDN/T BE ANYTHING TOO SUBSTANTIAL. HAVE AROUND AN INCH
FOR THE WI BORDER AREA AND TAPER IT OFF TO A DUSTING OVER THE N. IF
STRONGER PCPN MAKES IT TO MENOMINEE...COULD SEE A HEAVIER BURST OF
SNOW TOWARDS THE MORNING COMMUTE THAT COULD QUICKLY PRODUCE AN INCH
OR TWO OF SNOW. WITH THIS BEING THE FIRST MEASUREABLE SNOW FOR A
WHILE AND IT OCCURRING DURING THE MORNING COMMUTE...WITH CONTINUE
THE SPS FOR THE SCNTRL THROUGH THE MORNING HOURS.
FOR THE REST OF THE DAY...EXPECT THE PCPN TO QUICKLY TRANSITION TO
THE SE WITH THE BETTER LLVL WAA AND END UP PRODUCING A CLOUDY DAY.
HAVE LINGERING SOME LOW POPS FOR SOME LIGHT RAIN SHOWERS AND
DRIZZLE THROUGH THE EARLY AFTN...BUT THEN EXPECT THAT TO COME TO AN
END.
TONIGHT...SFC HIGH PRESSURE RIDGE MOVES BACK INTO THE AREA...BUT
LLVL MOISTURE BELOW H900 REMAINS. THINK THE LOW CLOUDS WILL PERSIST
AND BE THE THICKEST OVER THE CNTRL CWA...WHERE THE LLVL MOISTURE
REMAINS IN PLACE AND H925 TEMPS OF -3C OVER LK MI WILL HELP WITH
SOME LK INSTABILITY. IN ADDITION...LIGHT SE UPSLOPE FLOW WILL HELP
KEEP THE CLOUDS IN PLACE. FARTHER E...DRY ERLY FLOW FROM THE SFC
RIDGE WILL KEEP SKIES MORE PARTLY CLOUDY TOWARDS LUCE COUNTY. OVER
THE FAR W...COULD BE SOME DOWNSLOPE BREAKS IN THE CLOUDS OVER WRN
GOGEBIC/ONTONAGON COUNTIES. WITH THIS LLVL MOISTURE AND UPSLOPE
FLOW...COULD BE SOME -DZ OR LOW CLOUD FOG FROM KMQT/KSAW TO KIMT BUT
OVERALL POTENTIAL SEEMS LIMITED TO MENTION AT THIS POINT.
SATURDAY...SFC HIGH SLIDES E AS STRONG UPPER JET ROUNDING
THE AMPLIFYING UPPER RIDGE MOVES INTO SRN MANITOBA/ONTARIO.
SHORTWAVE ASSOCIATED WITH THIS JET WILL DEVELOP A SFC LOW IN THE
SAME AREA ON SAT. EXPECT LLVL MOISTURE TO BE LINGERING INTO THE
MORNING. DIURNAL MIXING AND WINDS BACKING TO THE S SHOULD
ALLOW FOR THE LOW CLOUDS TO BREAK UP TOWARDS MID DAY...WITH THEM
HANGING ON THE LONGEST OVER THE UPSLOPE CNTRL CWA.
AS THE LOW CLOUDS DIMINISH...MID CLOUDS WILL BEGIN MOVING IN
AHEAD OF THE SHORTWAVE AND UNDER THE INCREASING WAA...ESPECIALLY
OVER THE NW HALF OF THE CWA. MOISTURE IS MARGINAL...AND BEST FORCING
FROM THE SHORTWAVE IS IN CANADA...SO DON/T THINK THE CHANCES OF PCPN
DEVELOPING IS TOO HIGH BUT WILL CONTINUE TO MENTION SLIGHTS. DID
BRING THE POPS A LITTLE FARTHER S TO COVER THE KEWEENAW PENINSULA.
LOWERED TD VALUES SOME OVER THE FAR ERN CWA...WHERE THERE WILL BE
GREATER MIXING WITH LESS CLOUDS AND DRIER AIR CLOSER TO THE SFC
RIDGE. DIDN/T GO AS LOW AS NAM/ECMWF ML DEWPOINT VALUES...IN THE
MID TEENS...BUT LOWERED INTO THE LOWER 20S. WARMEST HIGHS WILL
BE OUT WEST...WHERE THE SRLY FLOW WILL PULL H875 TOWARDS 10C.
WON/T MIX QUITE THAT HIGH...BUT SHOULD MIX BETWEEN THERE AND
H900...WHICH WOULD PRODUCE HIGHS IN THE UPPER 50S TO NEAR 60. IF IT
COULD MIX SLIGHTLY HIGHER...WOULD EASILY HAVE TEMPS IN THE MID 60S.
FARTHER E...THE LINGERING LOW CLOUDS IN THE MORNING WILL LIMIT THE
WARM UP...ALONG WITH COOLER H900 TEMPS LINGERING UNDER THE INITIAL
ESE FLOW. TEMPS OVER THE CNTRL/EAST WILL DEPEND ON HOW QUICKLY THE
WARMER AIR ALOFT ARRIVES IN THE AFTN...BUT THE BREAKS TOWARDS MID
DAY WILL PRODUCE HIGHS IN THE MID 40S TO LOWER 50S.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 423 AM EDT FRI MAR 30 2012
GFS SHOWS A RIDGE BUILDING INTO THE AREA ON SUNDAY WITH A SHORTWAVE
PASSING BY TO THE NORTH SAT NIGHT. A WARM FRONT COMES THROUGH ON
SUNDAY NIGHT WITH TROUGHING MOVING IN FOR MONDAY. THIS WILL CONTINUE
TO BE QUITE ACTIVE THIS PERIOD WITH PCPN CHANCES OVER THE NORTH AND
EAST SAT NIGHT AND THEN OVER THE AREA FOR SUNDAY NIGHT AND MONDAY.
WENT WITH CHANCE POPS FOR THESE TIME PERIODS. OVERALL...DID NOT MAKE
TOO MANY CHANGES TO THE GOING FORECAST FOR TEMPERATURES OR WEATHER.
IN THE EXTENDED...ABOVE NORMAL TEMPERATURES CONTINUE...BUT
CONFIDENCE IS FAIRLY LOW AS POSITION OF FRONTS COULD BE TRICKY FOR
HIGH TEMPERATURES. IF THE WARM FRONT AND WARM SECTOR PART OF THE
STORM MAKES IT THROUGH THE AREA...COULD BE VERY WARM. RIGHT
NOW...GFS AND ECMWF TAKE SFC LOW PRESSURE TO THE SOUTH AND KEEP THE
AREA MORE TOWARDS THE COLDER PART OF THE STORM. CHANCE POPS CONTINUE
MONDAY INTO TUESDAY BEFORE DRY WEATHER MOVES IN FOR TUE NIGHT AND
LASTS INTO THURSDAY AS TROUGHING CONTINUES TO THE EAST OF THE AREA
WITH UPPER LEVEL RIDGING TO THE WEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 135 AM EDT FRI MAR 30 2012
A SHORTWAVE MOVING TOWARD THE AREA WILL BRING PCPN INTO UPPER
MICHIGAN. HOWEVER...THE GREATER FORCING AND HEAVIER AMOUNTS ARE
EXPECTED TO REMAIN SOUTH OF THE TAF SITES. NEVERTHELESS...SOME
-SN/RA WILL MOVE INTO IWD OVERNIGHT AND EVENTUALLY TOWARD CMX AND
SAW TOWARD 12Z. CIGS SHOULD DROP INTO THE MVFR RANGE AS THE PCPN
DEVELOPS. CONTINUED TO USE THE NAM FOR TIMING OF PRECIP AND MOISTURE
FOR LOW CLOUDS. CONFIDENCE IN PRECIP CHANCES AND TIMING IS LOWER
GIVEN TRENDS TOWARD A MORE SOUTHERN TRACK OF THE PCPN AREA.
HOWEVER...EXPECT THAT WITH UPSLOPE ESE FLOW INTO CMX/SAW MVFR
CONDITIONS ARE STILL ON TRACK. BY LATER IN THE DAY...SOME
IMRPROVEMENT IS EXPECTED WITH VFR CONDITIONS AT IWD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 423 AM EDT FRI MAR 30 2012
LAKE SUPERIOR WILL BE BETWEEN HIGH PRESSURE IN ONTARIO AND A LOW
PRESSURE SYSTEM MOVING THROUGH NRN ILLINOIS. THIS WILL PRODUCE SE
WINDS UP TO 25KTS TODAY...BEFORE DIMINISHING THIS AFTN/EVENING...AS
A HIGH PRESSURE RIDGE REESTABLISHES ITSELF OVER LAKE SUPERIOR.
THIS SHOULD KEEP WINDS BELOW 25KTS THROUGH THE WEEKEND AS
ANOTHER LOW MOVES THROUGH MANITOBA/ONTARIO ON SATURDAY. LOW
PRESSURE DEVELOPING OVER THE NORTHERN/CENTRAL PLAINS ON SUNDAY WILL
APPROACH THE GREAT LAKES FOR THE BEGINNING OF NEXT WEEK. THIS LOW
WILL WEAKEN AS IT MOVES ACROSS THE GREAT LAKES ON MONDAY AND
TUESDAY AND WINDS SHOULD STAY BELOW 20KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...07
AVIATION...JLB
MARINE...SRF
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1156 PM CDT THU MAR 29 2012
.UPDATE...
ISSUED AT 949 PM CDT THU MAR 29 2012
CLOUD COVER AND SCATTERED LIGHT SHOWERS SHIFTING E OF THE
FORECAST AREA LATE THIS EVNG...WITH A CLEAR SKY FOR MOST OF OUR
AREA. CONVECTIVE CLUSTERS MOVING FROM ERN NEBRASKA AND NWRN MO
NEWD THROUGH SWRN AND S CNTRL IA IN AREA OF STRONG 850 MB
WAA...MOISTURE CONVERGENCE AND THETA E ADVECTION ON NOSE OF SLY
LOW LEVEL JET. THIS ACTIVITY WAS ALSO AHEAD OF A SHORTWAVE TROUGH
MOVING EWD THROUGH THE NRN PLAINS...AND NEAR AND N-NE OF SFC LOW
OVER SERN NEBRASKA AND N OF WARM FRONT EXTENDING SE OF SFC LOW.
MOST OF THESE STORMS WERE MOVING EWD OR NEWD. IF ENOUGH OF AN
ORGANIZED COLD POOL DEVELOPS COULD SEE SOME OF THIS ACTIVITY
DROPPING SEWD. IT APPEARS THAT MOST OF THE SHOWER AND
THUNDERSTORM ACTIVITY WILL BE MAINLY CONFINED TO NERN MO AND W
CNTRL IL LATE TGT AHEAD OF THE SFC LOW MOVING EWD ALONG THE MO IA
BORDER AND N OF THE WARM FRONT EXTENDING SE OF THE SFC LOW. HAD TO
LOWER TEMPERATURES OVER NERN MO AND W CNTRL IL WHERE IT HAS FALLEN
INTO THE LOWER 50S. TEMPERATURES HERE SHOULD REMAIN NEARLY STEADY
OR ACTUALLY RISE A LITTLE OVERNIGHT.
GKS
&&
.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 1138 PM CDT THU MAR 29 2012
THE SURFACE LOW HAS PROGRESSED INTO FAR NW MO WITH THE COLD FRONT
TRAILING INTO CENTRAL KS AND WARM FRONT STRETCHING THROUGH WEST
CENTRAL MO INTO SE MO. THUNDERSTORMS WHICH FORMED EARLIER ACROSS
THE CENTRAL PLAINS HAVE DIMINISHED SIGNIFICANTLY IN COVERAGE WHILE
A LARGE THUNDERSTORM COMPLEX WAS CENTERED IN IOWA WITH THE
SOUTHERN PORTION POKING INTO NW MO. THE SURFACE LOW WILL TRACK
INTO SE IA BY DAYBREAK AND EASTWARD INTO THE OH VALLEY ON FRIDAY.
THUNDERSTORM CHANCES OVERNIGHT DEPEND ON WHETHER ANY ACTIVITY FROM
THE IOWA COMPLEX WILL SINK FAR ENOUGH SOUTH TO IMPACT KUIN. I CANT
RULE IT OUT AT THIS TIME AND WILL KEEP WITH THE CURRENT FORECAST
OF VCTS BEGINNING AT 08Z. NOT EXPECTING ANY ACTIVITY FURTHER SOUTH
AHEAD OF THE ADVANCING COLD FRONT OVERNIGHT INTO THE FIRST PART OF
FRIDAY MORNING. THUNDERSTORMS MAY ATTEMPT TO DEVELOP ALONG THE
COLD FRONT BETWEEN 15-19Z FRIDAY AS IT MOVES THROUGH THE ST LOUIS
METRO AREA...BUT UNCERTAINTY IS HIGH.
SPECIFICS FOR KSTL...
TRANQUIL WEATHER EXPECTED OVERNIGHT WITH VFR CONDITIONS
DOMINATING. HIGH CLOUDS WILL BE ON THE INCREASE AS A WARM FRONT
LIFTS NORTHWARD THROUGH THE AREA.
ANY THREAT OF SHOWERS AND THUNDERSTORMS IN THE ST LOUIS AREA
SHOULD BE FROM 15Z-19Z FRIDAY ALONG AND AHEAD OF THE ADVANCING
COLD FRONT. CONFIDENCE IS TOO LOW TO INCLUDE THIS FAR OUT IN THE
FORECAST AND FOR NOW HAVE JUST MENTIONED VCSH AND A CB CLOUD
GROUP.
GLASS
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 59 77 53 79 / 40 40 10 10
QUINCY 53 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 HASTINGS NE
328 AM CDT FRI MAR 30 2012
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT. A FAIRLY PROGRESSIVE
ZONAL FLOW PATTERN WAS IN PLACE ACROSS THE CENTRAL PLAINS WITH ONE
SHORTWAVE TRANSLATING TO OUR EAST...EAST OF THE MISSOURI
RIVER...WITH ANOTHER UPSTREAM SHORTWAVE TROUGH LOCATED IN EASTERN
WY/CO. CURRENTLY AT THE SURFACE...LOW PRESSURE WAS CENTERED IN
NORTHWEST MISSOURI WITH COOL FRONTAL BOUNDARY STRETCHING THROUGH
CENTRAL KANSAS. SFC DPS REMAIN HIGH ALONG THE MISSOURI RIVER INTO
NORTH CENTRAL AND EASTERN KANSAS WITH READINGS IN THE 50S TO
AROUND 60F AND HRRR SUGGESTS SOME FOG DEVELOPMENT ACROSS NORTHEAST
KANSAS INTO SOUTHEAST NEBRASKA OR JUST ON THE PERIPHERY OF OUR
SOUTHEAST CWA. OBSERVATION AT 08Z AT BELOIT SHOWED VSBY DROPPED TO
ONE QUARTER MILE AND IF TRENDS CONTINUE FOG HEADLINE WILL BE
WARRANTED.
AFOREMENTIONED UPSTREAM SHORTWAVE WILL CROSS OUR CWA AROUND
MIDDAY/EARLY AFTERNOON WITH NEGLIGIBLE EFFECT OTHER THAN INCREASING
CLOUD COVER AND WIND SHIFT TO A MORE WESTERLY DIRECTION AS
ASSOCIATED SURFACE TROUGH SLIDES EAST. CONVECTIVE TEMPS ARE IN THE
MID 70S THIS AFTERNOON AND EXPECT SOME MID LEVEL CU DEVELOPMENT
THIS AFTERNOON WHICH LOOKS TO SLOW TEMP RISE THIS AFTERNOON AND
LOWERED MAX TEMPS BY JUST A DEGREE OR TWO. MODEL FORECAST
SOUNDINGS SUGGEST DEEP MIXING ACROSS OUR WESTERN CWA WITH SFC DPS
DROPPING TO THE 30S THIS AFTN. LOW RELATIVE HUMIDITIES ACROSS OUR
WESTERN CWA...MAINLY DAWSON COUNTY...DROP NEAR 20 PERCENT THIS
AFTERNOON. WIND SPEEDS DO NOT APPEAR EXTREMELY STRONG BUT GUSTS
OVER 20 MPH CANNOT BE RULED OUT AND RIGHT NOW CONDITIONS APPEAR
CLOSE BUT NOT QUITE AT FIRE WEATHER CRITERIA...HOWEVER WILL NEED
TO MONITOR CONDITIONS CLOSELY THIS AFTN IN WESTERN ZONES.
HEADING INTO THE WEEKEND...DRY AND WARM...OR SHALL WE SAY HOT
CONDITIONS FOR LATE MARCH/EARLY APRIL WILL SETTLE INTO OUR REGION.
HEIGHTS RISE TONIGHT BEHIND DEPARTING SHORTWAVE TROUGH...WITH UPPER
RIDGING BUILDING ACROSS THE CENTRAL PLAINS ON SATURDAY AHEAD OF AN
UPPER TROUGH DEEPENING ALONG THE WEST COAST. THE RIDGE REMAINS IN
PLACE ACROSS THE CENTRAL PLAINS EARLY SUNDAY BEFORE FLOW
TRANSITIONS SOUTHWESTERLY BY AFTERNOON AS UPPER TROUGH MOVES INTO
THE ROCKIES. H85 TEMPS ARE RIGHT AROUND 20C BOTH SATURDAY AND
SUNDAY AND FORECAST SOUNDINGS SUGGEST MIXING WILL BE EVEN HIGHER
THAN H85. HAVE MAINTAINED UPPER 80S FOR HIGHS ON SATURDAY WITH A
DRIER AIRMASS IN PLACE AND WARMING AIDED BY DOWNSLOPE WIND
COMPONENT. BY SUNDAY LLVL FLOW TRANSITIONS SOUTHERLY WITH SFC
CYCLOGENESIS ALONG THE HIGH PLAINS AND MOISTURE RETURNS NORTH WITH
DPS RETURNING TO THE 50S. CURRENTLY HAVE HIGHS FORECAST IN THE
MID/UPPER 80S FOR SUNDAY. RECORD HIGHS BOTH SATURDAY AND SUNDAY
ARE IN THE 88 TO 90 RANGE FOR GRAND ISLAND...HASTINGS AND
KEARNEY...AND WE WILL BE RIGHT NEAR THERE.
SATURDAY WILL BE A DAY TO MONITOR FOR FIRE WEATHER CONCERNS AS WELL
AS A LARGER PORTION OF OUR CWA WILL SEE LOW RELATIVE HUMIDITIES
BELOW 20 PERCENT...BUT THAT BEING SAID...WINDS ARE NOT LOOKING
OVERLY STRONG AT THIS POINT.
UPPER TROUGH CONTINUES TO DEEPEN IN THE SOUTHERN ROCKIES SUNDAY
NIGHT AND FRONTAL PROGRESSION HAS SLOWED. WITH SLOWER FROPA...HAVE
RAISED LOW TEMPS QUITE A BIT AS DPS LOOK TO HOLD IN THE 50S FOR THE
MOST PART THROUGH THE NIGHT. WITH FRONT MAINLY TO OUR WEST OR ON
THE PERIPHERY OF OUR WESTERN COUNTIES...HAVE REMOVED POPS FOR THIS
TIME FRAME.
.LONG TERM...STARTING 12Z MONDAY. GUIDANCE SUGGESTS A MID LEVEL LOW
WILL PUSH ACROSS THE SOUTHERN PLAINS DURING THE DAY MONDAY...WITH
A MID LEVEL SHORT WAVE ALSO PUSHING ACROSS THE CENTRAL AND
NORTHERN PLAINS ON MONDAY. AN ASSOCIATED LOW LEVEL BAROCLINIC ZONE
IS ALSO EXPECTED TO CLEAR OUR CWA EARLY MONDAY. ALTHOUGH THERE IS
STILL CONSIDERABLE UNCERTAINTY AS TO WHEN THE SURFACE FRONT WILL
ACTUALLY CLEAR THE AREA...INCREASED VALUES OF LOW LEVEL MOISTURE
AHEAD OF THE FRONT WILL STILL PROMOTE ENOUGH INSTABILITY FOR
CONVECTIVE DEVELOPMENT AND WITH QPF FIELDS FROM THE OPERATIONAL
GFS STILL SUGGESTING PRECIPITATION WILL BE REALIZED ACROSS OUR
EAST ON MONDAY...WILL GO AHEAD AND CONTINUE CARRYING SLIGHT
CHANCES POPS ACROSS OUR EAST FOR MONDAY. THE MID LEVEL LOW OVER
THE SOUTHERN PLAINS IS THEN EXPECTED TO LIFT TO THE NORTHEAST
MONDAY NIGHT...WITH PERHAPS ENOUGH MID LEVEL THERMAL ADVECTION TO
THE EAST AND NORTHEAST OF THE LOW FOR PRECIPITATION PRODUCTION
ACROSS PORTIONS OF OUR CWA MONDAY NIGHT INTO TUESDAY AND AS A
RESULT...WENT AHEAD AND CONTINUED SLIGHT CHANCE POPS ACROSS MUCH
OF THE CWA MONDAY NIGHT INTO TUESDAY. AN OVERALL LACK IN KINEMATIC
FORCING DUE TO STRENGTHENING UPPER LEVEL RIDGING ACROSS THE
CENTRAL CONUS SHOULD KEEP US DRY TUESDAY NIGHT THROUGH THURSDAY.
RELATIVELY COOLER WEATHER WILL BE OBSERVED DURING MUCH OF THE
EXTENDED FORECAST PERIOD AS A COOLER AIRMASS INFILTRATES OUR AREA
POST-FROPA ON MONDAY. THAT BEING SAID...TEMPERATURES ARE STILL
EXPECTED TO REMAIN AT ABOVE-NORMAL LEVELS WITH HIGHS GENERALLY IN
THE 60S AND 70S...AND LOWS GENERALLY IN THE 30S AND 40S.
&&
.AVIATION...06Z KGRI TAF. VFR CONDITIONS TO CONTINUE AT KGRI
THROUGH THE NEXT 24 HOURS. INCREASING HIGH LEVEL CLOUDS WILL BE
OBSERVED...BUT NOTHING BELOW 10000FT AGL IS CURRENTLY EXPECTED.
SURFACE WINDS WILL REMAIN LIGHT AND VARIABLE TONIGHT...INCREASING
FROM THE SOUTHWEST DURING THE DAY FRIDAY. VISIBILITY RESTRICTIONS
ARE NOT EXPECTED THROUGH THE NEXT 24 HOURS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM...BRYANT
AVATION...BRYANT
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1206 AM CDT FRI MAR 30 2012
.AVIATION...06Z KGRI TAF. VFR CONDITIONS TO CONTINUE AT KGRI
THROUGH THE NEXT 24 HOURS. INCREASING HIGH LEVEL CLOUDS WILL BE
OBSERVED...BUT NOTHING BELOW 10000FT AGL IS CURRENTLY EXPECTED.
SURFACE WINDS WILL REMAIN LIGHT AND VARIABLE TONIGHT...INCREASING
FROM THE SOUTHWEST DURING THE DAY FRIDAY. VISIBILITY RESTRICTIONS
ARE NOT EXPECTED THROUGH THE NEXT 24 HOURS.
&&
.PREV DISCUSSION... /ISSUED 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.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION...BRYANT
AREA FORECAST DISCUSSION...CORRECTED
NWS BISMARCK ND
422 AM CDT FRI MAR 30 2012
.SHORT TERM...TODAY THROUGH SATURDAY...
THE HIGHLIGHTS OF THE SHORT TERM WILL BE FOG AND FIRE WEATHER FOR
TODAY...FOLLOWED BY NEAR RECORD HIGHS ON SATURDAY FOR THE SOUTHERN
HALF OF THE CWA.
AS DEPICTED BY HRRR FORECAST CYCLES THROUGHOUT THE EARLY MORNING
HOURS...WIDESPREAD DENSE FOG HAS PUSHED TOWARDS NORTH DAKOTA
HIGHWAY 14 THROUGH THE NIGHT WITH WEAK EASTERLY SURFACE FLOW ON
THE EASTERN SIDE OF A QUASI-STATIONARY FRONT. THE DENSE FOG
ADVISORY ISSUED EARLIER TONIGHT REMAINS IN EFFECT THROUGH 17 UTC
THIS MORNING FOR LOCATIONS GENERALLY ALONG AND EAST OF HIGHWAY
14...WITH PATCHY FOG POSSIBLY ALONG THE HIGHWAY 83 CORRIDOR.
FOR THE REMAINDER OF TODAY THE FOCUS WILL BE ON CRITICAL FIRE
WEATHER CONDITIONS ACROSS FAR WESTERN NORTH DAKOTA...IN GENERAL
ALONG AND WEST OF NORTH DAKOTA HIGHWAY 8. THE 30/00 UTC GFS AND ITS
ASSOCIATED STATISTICAL GUIDANCE HAVE TRENDED TOWARDS THE WEAKER
WINDS OF THE NAM. HOWEVER...WITH ADIABATIC LAPSE RATES FORECAST
THROUGH 700 MB BY LATE AFTERNOON...EXCELLENT MOMENT EM TRANSFER IS
FORECAST TO YIELD SUSTAINED WINDS OF 15-20 KTS WITH GUST TO NEAR 25
KTS...AND AFTERNOON MINIMUM RELATIVE HUMIDITY VALUES NEAR 20 PERCENT
WITH TEMPERATURES IN THE LOWER 70S. GIVEN THE ABUNDANCE OF DRY
FUELS AND LITTLE GREEN UP...HAVE UPGRADED THE FIRE WEATHER WATCH
TO A RED FLAG WARNING FROM 18-02 UTC.
FOR TONIGHT...THE AFOREMENTIONED STATIONARY FRONT IS FORECAST TO
SHIFT EAST AS A WARM FRONT AS A CLIPPER SYSTEM PROPAGATES ACROSS
SOUTHERN CANADA...WITH A COLD FRONT ENTERING THE FAR NORTHWEST
LATE TONIGHT. GIVEN THE RELATIVELY MILD TEMPERATURES FORECAST
TODAY AND BOUNDARY LAYER MIXING THROUGH THE NIGHT WITH THE PASSAGE
OF THE CLIPPER TO THE NORTH...A RELATIVELY MILD OVERNIGHT IS
FORECAST WITH LOWS GENERALLY IN THE 40S.
THE AFOREMENTIONED COLD FRONT IS FORECAST TO STALL OUT BETWEEN THE
US HIGHWAY 2 AND ND HIGHWAY 200 CORRIDORS ON SATURDAY MORNING AND
SLOWLY LIFT NORTH THROUGH THE DAY AS A WARM FRONT. RECORD HIGH
TEMPERATURES ARE POSSIBLE SOUTH OF THE FRONT ON SATURDAY. SHOWN
BELOW ARE THE FORECAST AND RECORD HIGHS FOR SELECT LOCATIONS ACROSS
THE CWA.
SITE FORECAST RECORD YEAR
DICKINSON 76 75 1964
MINOT 70 68 1963
BISMARCK 74 75 2003
JAMESTOWN 71 77 1963
THESE FORECAST HIGHS ARE COOLER COMPARED TO PREVIOUS
FORECASTS...LARGELY DUE LOWER MAGNITUDES OF FORECAST MIXING...WHICH
HOWEVER WILL HELP TO KEEP FIRE WEATHER CONDITIONS FROM REACHING
CRITICAL LEVELS.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
THE MEDIUM RANGE MODELS CONTINUE TO TREND DRIER AND DRIER WITH
RESPECT TO THE NEXT LOW PRESSURE SYSTEM EXPECTED TO AFFECT THE
REGION THIS WEEKEND. THE ECMWF/GFS/GEM ARE IN FAIRLY GOOD AGREEMENT
WITH THE OVERALL DRY/WARM WEATHER PATTERN OVER NORTH DAKOTA NEXT
WEEK. AS A RESULT...DECIDED TO USE A BLEND OF SOLUTIONS FOR THIS
FORECAST PACKAGE.
SURFACE CYCLOGENESIS IS FORECAST TO DEVELOP ACROSS THE CANADIAN
ROCKIES SATURDAY NIGHT. A STRENGTHENING LOW-LEVEL JET COMBINED WITH
INCREASING DYNAMICS ALOFT SHOULD GENERATE A SLIGHT CHANCE OF SHOWERS
NORTH (PROXIMATE TO THE STRONGEST UPPER DYNAMICS) SATURDAY NIGHT.
THE SHOWALTER INDEX INDICATES THERE WILL BE A POTENTIAL FOR
THUNDERSTORM ACTIVITY NORTHWEST FROM 00Z-06Z...THEN MID-LEVEL LAPSE
RATES BECOME RELATIVELY MORE STABLE AFTER 06Z PRECLUDING ANY
THUNDERSTORM DEVELOPMENT AFTER MIDNIGHT SATURDAY NIGHT. THE SLIGHT
CHANCES FOR SHOWERS WILL CONTINUE NORTH (AGAIN...PROXIMATE TO THE
STRONGEST FORCING) SUNDAY AS THE LOW LIFTS INTO NORTHERN
SASKATCHEWAN AND PUSHES A FRONT THROUGH NORTH DAKOTA. WINDY
CONDITIONS WILL DEVELOP IN THE WAKE OF THE FRONT WEST AND CENTRAL.
HUMIDITIES WILL ALSO PLUMMET WITH A VERY HIGH FIRE DANGER
EXPECTED SOUTHWEST OF THE MISSOURI RIVER SUNDAY AFTERNOON.
HIGH PRESSURE BUILDING INTO THE STATE WILL MAINTAIN BREEZY TO WINDY
CONDITIONS ACROSS WESTERN AND CENTRAL NORTH DAKOTA SUNDAY NIGHT AND
MONDAY. THE COMBINATION OF WINDS AND DRY CONDITIONS WILL GENERATE A
VERY HIGH FIRE DANGER MAINLY ALONG AND SOUTH OF HIGHWAY 2 MONDAY
AFTERNOON.
AN AMPLIFYING UPPER LEVEL RIDGE IS FORECAST TO BUILD OVER THE
CENTRAL GREAT PLAINS TUESDAY THROUGH THURSDAY. DRY CONDITIONS AND A
WARMING TREND ARE EXPECTED THROUGH THE END OF THE FORECAST PERIOD.
&&
.AVIATION...LIGHT WINDS AND A STABLE/MOIST BOUNDARY LAYER WILL
MAINTAIN LIFR CONDITIONS IN DENSE FOG ACROSS KJMS THROUGH THE MID TO
LATE MORNING HOURS. MVFR VSBYS WILL BE POSSIBLE FROM KMOT-KBIS
THROUGH THE EARLY MORNING HOURS. OTHERWISE...VFR CONDITIONS ARE
EXPECTED TO DEVELOP FROM WEST TO EAST DURING THE MORNING HOURS WITH
VFR CONDITIONS EXPECTED AREA WIDE BY THIS AFTERNOON. LINGERING
MOISTURE COULD ALLOW FOR THE DEVELOPMENT OF IFR VSBYS OVER KJMS ONCE
AGAIN AFTER 00Z SATURDAY.
&&
.FIRE WEATHER...
THE FIRE WEATHER WATCH FOR FAR WESTERN NORTH DAKOTA TODAY HAS BEEN
UPGRADED TO A RED FLAG WARNING. SOUTHWEST WINDS SUSTAINED TO 20
MPH WITH GUSTS OF 25 TO 30 MPH...MINIMUM RH VALUES NEAR 20
PERCENT AND TEMPERATURES IN THE LOWER 70S ARE EXPECTED...COUPLED
WITH AN ABUNDANCE OF DRY FUELS WITH LITTLE GREEN UP.
FOR SATURDAY...A COLD FRONT IS FORECAST TO STALL OUT BETWEEN THE
US HIGHWAY 2 AND ND HIGHWAY 200 CORRIDORS DURING THE MORNING HOURS
AND SLOWLY LIFT NORTH AS A WARM FRONT THROUGH THE DAY. HIGHS IN
THE MID TO UPPER 70S ARE FORECAST SOUTH OF THE FRONT WITH AFTERNOON
RH VALUES OF 20 TO 25 PERCENT. HOWEVER...THE OVERALL WIND FIELD
...AND THUS THE FIRE DANGER....IS FORECAST TO BE WEAKER COMPARED TO
FRIDAY...WITH SOUTHWEST WINDS OF 10 TO 15 MPH EXPECTED SATURDAY AFTERNOON.
HOWEVER...CRITICAL FIRE WEATHER CONDITIONS ARE POSSIBLE ON
SUNDAY....ESPECIALLY ACROSS THE SOUTHWEST. WINDY AND DRY
CONDITIONS ARE POSSIBLE BEHIND A COLD FRONT WITH THE POTENTIAL FOR
SUSTAINED WINDS OF 20 TO 30 MPH AND GUSTS POSSIBLY NEAR 40 MPH AS
GOOD MIXING YIELDS RH VALUES DURING THE AFTERNOON AS LOW AS 20
PERCENT. A FIRE WEATHER WATCH MAY BE NEEDED FOR THE SOUTHWEST ON
SUNDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ THIS AFTERNOON TO 9 PM
CDT /8 PM MDT/ THIS EVENING FOR NDZ001-009-017-018-031>033-040-
041-043-044.
DENSE FOG ADVISORY UNTIL 11 AM CDT THIS MORNING FOR NDZ004-005-
012-013-022-023-025-036-037-047-048-050-051.
&&
$$
SHORT TERM/FIRE...AYD
LONG TERM/AVIATION....TM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
347 AM CDT FRI MAR 30 2012
.SHORT TERM...TODAY THROUGH SATURDAY...
THE HIGHLIGHTS OF THE SHORT TERM WILL BE FOG AND FIRE WEATHER FOR
TODAY...FOLLOWED BY NEAR RECORD HIGHS ON SATURDAY FOR THE SOUTHERN
HALF OF THE CWA.
AS DEPICTED BY HRRR FORECAST CYCLES THROUGHOUT THE EARLY MORNING
HOURS...WIDESPREAD DENSE FOG HAS PUSHED TOWARDS NORTH DAKOTA
HIGHWAY 14 THROUGH THE NIGHT WITH WEAK EASTERLY SURFACE FLOW ON
THE EASTERN SIDE OF A QUASI-STATIONARY FRONT. THE DENSE FOG
ADVISORY ISSUED EARLIER TONIGHT REMAINS IN EFFECT THROUGH 17 UTC
THIS MORNING FOR LOCATIONS GENERALLY ALONG AND EAST OF HIGHWAY
14...WITH PATCHY FOG POSSIBLY ALONG THE HIGHWAY 83 CORRIDOR.
FOR THE REMAINDER OF TODAY THE FOCUS WILL BE ON CRITICAL FIRE
WEATHER CONDITIONS ACROSS FAR WESTERN NORTH DAKOTA...IN GENERAL
ALONG AND WEST OF NORTH DAKOTA HIGHWAY 8. THE 30/00 UTC GFS AND ITS
ASSOCIATED STATISTICAL GUIDANCE HAVE TRENDED TOWARDS THE WEAKER
WINDS OF THE NAM. HOWEVER...WITH ADIABATIC LAPSE RATES FORECAST
THROUGH 700 MB BY LATE AFTERNOON...EXCELLENT MOMENT EM TRANSFER IS
FORECAST TO YIELD SUSTAINED WINDS OF 15-20 KTS WITH GUST TO NEAR 25
KTS...AND AFTERNOON MINIMUM RELATIVE HUMIDITY VALUES NEAR 20 PERCENT
WITH TEMPERATURES IN THE LOWER 70S. GIVEN THE ABUNDANCE OF DRY
FUELS AND LITTLE GREEN UP...HAVE UPGRADED THE FIRE WEATHER WATCH
TO A RED FLAG WARNING FROM 18-02 UTC.
FOR TONIGHT...THE AFOREMENTIONED STATIONARY FRONT IS FORECAST TO
SHIFT EAST AS A WARM FRONT AS A CLIPPER SYSTEM PROPAGATES ACROSS
SOUTHERN CANADA...WITH A COLD FRONT ENTERING THE FAR NORTHWEST
LATE TONIGHT. GIVEN THE RELATIVELY MILD TEMPERATURES FORECAST
TODAY AND BOUNDARY LAYER MIXING THROUGH THE NIGHT WITH THE PASSAGE
OF THE CLIPPER TO THE NORTH...A RELATIVELY MILD OVERNIGHT IS
FORECAST WITH LOWS GENERALLY IN THE 40S.
THE AFOREMENTIONED COLD FRONT IS FORECAST TO STALL OUT BETWEEN THE
US HIGHWAY 2 AND ND HIGHWAY 200 CORRIDORS ON SATURDAY MORNING AND
SLOWLY LIFT NORTH THROUGH THE DAY AS A WARM FRONT. RECORD HIGH
TEMPERATURES ARE POSSIBLE SOUTH OF THE FRONT ON SATURDAY. SHOWN
BELOW ARE THE FORECAST AND RECORD HIGHS FOR SELECT LOCATIONS ACROSS
THE CWA.
SITE FORECAST RECORD YEAR
DICKINSON 76 75 1964
MINOT 70 68 1963
BISMARCK 74 75 2003
JAMESTOWN 71 77 1963
THESE FORECAST HIGHS ARE COOLER COMPARED TO PREVIOUS
FORECASTS...LARGELY DUE LOWER MAGNITUDES OF FORECAST MIXING...WHICH
HOWEVER WILL HELP TO KEEP FIRE WEATHER CONDITIONS FROM REACHING
CRITICAL LEVELS.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
THE MEDIUM RANGE MODELS CONTINUE TO TREND DRIER AND DRIER WITH
RESPECT TO THE NEXT LOW PRESSURE SYSTEM EXPECTED TO AFFECT THE
REGION THIS WEEKEND. THE ECMWF/GFS/GEM ARE IN FAIRLY GOOD AGREEMENT
WITH THE OVERALL DRY/WARM WEATHER PATTERN OVER NORTH DAKOTA NEXT
WEEK. AS A RESULT...DECIDED TO USE A BLEND OF SOLUTIONS FOR THIS
FORECAST PACKAGE.
SURFACE CYCLOGENESIS IS FORECAST TO DEVELOP ACROSS THE CANADIAN
ROCKIES SATURDAY NIGHT. A STRENGTHENING LOW-LEVEL JET COMBINED WITH
INCREASING DYNAMICS ALOFT SHOULD GENERATE A SLIGHT CHANCE OF SHOWERS
NORTH (PROXIMATE TO THE STRONGEST UPPER DYNAMICS) SATURDAY NIGHT.
THE SHOWALTER INDEX INDICATES THERE WILL BE A POTENTIAL FOR
THUNDERSTORM ACTIVITY NORTHWEST FROM 00Z-06Z...THEN MID-LEVEL LAPSE
RATES BECOME RELATIVELY MORE STABLE AFTER 06Z PRECLUDING ANY
THUNDERSTORM DEVELOPMENT AFTER MIDNIGHT SATURDAY NIGHT. THE SLIGHT
CHANCES FOR SHOWERS WILL CONTINUE NORTH (AGAIN...PROXIMATE TO THE
STRONGEST FORCING) SUNDAY AS THE LOW LIFTS INTO NORTHERN
SASKATCHEWAN AND PUSHES A FRONT THROUGH NORTH DAKOTA. WINDY
CONDITIONS WILL DEVELOP IN THE WAKE OF THE FRONT WEST AND CENTRAL.
HUMIDITIES WILL ALSO PLUMMET WITH A VERY HIGH FIRE DANGER
EXPECTED SOUTHWEST OF THE MISSOURI RIVER SUNDAY AFTERNOON.
HIGH PRESSURE BUILDING INTO THE STATE WILL MAINTAIN BREEZY TO WINDY
CONDITIONS ACROSS WESTERN AND CENTRAL NORTH DAKOTA SUNDAY NIGHT AND
MONDAY. THE COMBINATION OF WINDS AND DRY CONDITIONS WILL GENERATE A
VERY HIGH FIRE DANGER MAINLY ALONG AND SOUTH OF HIGHWAY 2 MONDAY
AFTERNOON.
AN AMPLIFYING UPPER LEVEL RIDGE IS FORECAST TO BUILD OVER THE
CENTRAL GREAT PLAINS TUESDAY THROUGH THURSDAY. DRY CONDITIONS AND A
WARMING TREND ARE EXPECTED THROUGH THE END OF THE FORECAST PERIOD.
&&
.AVIATION...LIGHT WINDS AND A STABLE/MOIST BOUNDARY LAYER WILL
MAINTAIN LIFR CONDITIONS IN DENSE FOG ACROSS KJMS THROUGH THE MID TO
LATE MORNING HOURS. MVFR VSBYS WILL BE POSSIBLE FROM KMOT-KBIS
THROUGH THE EARLY MORNING HOURS. OTHERWISE...VFR CONDITIONS ARE
EXPECTED TO DEVELOP FROM WEST TO EAST DURING THE MORNING HOURS WITH
VFR CONDITIONS EXPECTED AREA WIDE BY THIS AFTERNOON. LINGERING
MOISTURE COULD ALLOW FOR THE DEVELOPMENT OF IFR VSBYS OVER KJMS ONCE
AGAIN AFTER 00Z SATURDAY.
&&
.FIRE WEATHER...
THE FIRE WEATHER WATCH FOR FAR WESTERN NORTH DAKOTA TODAY HAS BEEN
UPGRADED TO A RED FLAG WARNING. SOUTHWEST WINDS SUSTAINED TO 20
MPH WITH GUSTS OF 25 TO 30 MPH...MINIMUM RH VALUES NEAR 20
PERCENT AND TEMPERATURES IN THE LOWER 70S ARE EXPECTED...COUPLED
WITH AN ABIDANCE OF DRY FUELS WITH LITTLE GREEN UP.
FOR SATURDAY...A COLD FRONT IS FORECAST TO STALL OUT BETWEEN THE
US HIGHWAY 2 AND ND HIGHWAY 200 CORRIDORS DURING THE MORNING HOURS
AND SLOWLY LIFT NORTH AS A WARM FRONT THROUGH THE DAY. HIGHS IN
THE MID TO UPPER 70S ARE FORECAST SOUTH OF THE FRONT WITH AFTERNOON
RH VALUES OF 20 TO 25 PERCENT. HOWEVER...THE OVERALL WIND FIELD
...AND THUS THE FIRE DANGER....IS FORECAST TO BE WEAKER COMPARED TO
FRIDAY...WITH SOUTHWEST WINDS OF 10 TO 15 MPH EXPECTED SATURDAY AFTERNOON.
HOWEVER...CRITICAL FIRE WEATHER CONDITIONS ARE POSSIBLE ON
SUNDAY....ESPECIALLY ACROSS THE SOUTHWEST. WINDY AND DRY
CONDITIONS ARE POSSIBLE BEHIND A COLD FRONT WITH THE POTENTIAL FOR
SUSTAINED WINDS OF 20 TO 30 MPH AND GUSTS POSSIBLY NEAR 40 MPH AS
GOOD MIXING YIELDS RH VALUES DURING THE AFTERNOON AS LOW AS 20
PERCENT. A FIRE WEATHER WATCH MAY BE NEEDED FOR THE SOUTHWEST ON
SUNDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ THIS AFTERNOON TO 9 PM
CDT /8 PM MDT/ THIS EVENING FOR NDZ001-009-017-018-031>033-040-
041-043-044.
DENSE FOG ADVISORY UNTIL 11 AM CDT THIS MORNING FOR NDZ004-005-
012-013-022-023-025-036-037-047-048-050-051.
&&
$$
SHORT TERM...AYD
LONG TERM....TM
AVIATION...TM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1200 AM CDT FRI MAR 30 2012
.DISCUSSION...
QUICK UPDATE FOR THE ISSUANCE OF A DENSE FOG ADVISORY THE TURTLE
MOUNTAINS THROUGH THE JAMES RIVER VALLEY EXTENDING WEST TOWARDS
NORTH DAKOTA HIGHWAYS 3 AND 14. THE LATEST HRRR LOW LEVEL CLOUD
COVER AND VISIBILITY FORECASTS AND THE 21 UTC SREF PROBABILITIES
OF VISIBILITY BELOW ONE MILE SUPPORT THE CONTINUATION AND
EXPANSION OF FOG WEST THROUGH THE OVERNIGHT HOURS.
&&
.AVIATION...
FOG SHOWING UP AT JAMESTOWN IN LIGHT WIND REGION. ADDED
SOME REDUCED VISIBILITY TO IFR THROUGH THE NIGHT UNTIL 8 AM CDT.
OTHERWISE VFR AT ALL OTHER TAF SITES THROUGH THE PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM FRIDAY AFTERNOON THROUGH FRIDAY EVENING
FOR NDZ001-009-017-018-031>033-040-041-043-044.
DENSE FOG ADVISORY UNTIL 10 AM CDT FRIDAY FOR NDZ004-005-012-013-
022-023-025-036-037-047-048-051.
&&
$$
UPDATE..AYD
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1121 PM CDT THU MAR 29 2012
.DISCUSSION...
QUICK UPDATE TO ADD PATCHY DENSE FOG TO THE TURTLE MOUNTAINS
THROUGH THE JAMES RIVER VALLEY THROUGH 06 UTC...SPREADING THE FOG
THEREAFTER WEST TOWARDS NORTH DAKOTA HIGHWAY 14...WHICH IS IN
AGREEMENT WITH THE LATEST HRRR LOW LEVEL CLOUD COVER AND
VISIBILITY FORECASTS AND THE 21 UTC SREF PROBABILITIES OF
VISIBILITY BELOW ONE MILE. WILL CONTINUE TO MONITOR TRENDS...AND
A DENSE FOG ADVISORY MAY BE NEEDED AT SOME POINT TONIGHT. ALL
OTHER FORECAST FIELDS WERE ON TRACK AND ADJUSTED TO THE LATEST 04
UTC OBSERVED TRENDS.
&&
.AVIATION...
FOG SHOWING UP AT JAMESTOWN IN LIGHT WIND REGION. ADDED
SOME REDUCED VISIBILITY TO IFR THROUGH THE NIGHT UNTIL 8 AM CDT.
OTHERWISE VFR AT ALL OTHER TAF SITES THROUGH THE PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM FRIDAY AFTERNOON THROUGH FRIDAY EVENING
FOR NDZ001-009-017-018-031>033-040-041-043-044.
&&
$$
SHORT TERM...AYD
AVIATION...WAA
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
444 AM CDT FRI MAR 30 2012
.DISCUSSION...
ISSUED A SMALL DENSE FOG ADVISORY FOR THE AREA OF CONCERN OUTLINED
IN THE DISCUSSION BELOW.
&&
.PREV DISCUSSION.../ISSUED AT 347 AM CDT/
AREAS OF FOG HAVE DEVELOPED OVERNIGHT EAST OF THE JAMES RIVER
VALLEY. AM WATCHING AREAS UP NORTH OF 90 AND EAST OF I-29 WHERE
VISIBILITIES HAVE CONSISTENTLY BEEN THE LOWEST DUE TO INCREASED
AMOUNTS OF LOW LEVEL MOISTURE FROM THE RAIN THURSDAY EVENING. FOG
APPEARS TO BE RELATIVELY SHALLOW RIGHT NOW...BUT RUC MODEL SOUNDINGS
SUGGESTS OVER THE NEXT FEW HOURS FOG WILL THICKEN. RAIN TOTALS WERE
FAIRLY LIGHT ESPECIALLY SOUTH OF I-90 SO THERE IS SOME QUESTION AS
TO HOW THICK THE FOG WILL GET DOW THERE. IF DENSE FOG BECOMES MORE
WIDESPREAD OVER THE PRE-DAWN HOURS...WILL ISSUE DENSE FOG ADVISORY.
OTHERWISE...EXPECTING FOG TO GRADUALLY BURN OFF TODAY LEADING TO A
PLEASANT DAY ACROSS THE AREA. SOUTHEAST WINDS WILL GRADUALLY
INCREASE FROM WEST TO EAST TODAY...BUT WILL STILL NOT BE ALL THAT
STRONG. TEMPERATURES WILL STILL BE 20-25 DEGREES ABOVE NORMAL.
GREATEST MIXING IS IN THE WEST TODAY...AND SOME CONCERN ACROSS
SOUTHWEST MINNESOTA THAT LOW LEVEL MOISTURE MAY NOT MIX OUT TODAY.
AS SUCH...ADDED MENTION OF PATCHY FOG THERE BUT MAY NEED TO BEEF UP
WORDING IN FUTURE UPDATES.
WARMING TREND EXPECTED OVER THE WEEKEND. APPEARS AS THOUGH FAIRLY
DENSE CIRRUS SHIELD WILL HINDER WARMING POTENTIAL ON
SATURDAY...HOWEVER...SUNDAY LOOKS TO BE DOWNRIGHT HOT WITH STRONG
UPPER LEVEL RIDGE BUILDING INTO THE AREA. HAVE INCREASED FORECAST
HIGHS SLIGHTLY...ESPECIALLY ACROSS WESTERN CWA WITH SLOWER
PROGRESSION OF THE FRONT. CURRENT FORECAST HIGHS ARE AROUND 3
DEGREES ABOVE RECORD IN MOST LOCATIONS.
NOT A LOT OF MOISTURE OR UPPER LEVEL DYNAMICS WITH FRONT ON SUNDAY
NIGHT. AS SUCH...CONTINUED TO DECREASE POP MENTION SUNDAY NIGHT
INTO MONDAY MORNING.
ALTHOUGH WINDS WILL BE STRONG OUT OF THE NORTHWEST AND TEMPERATURES
WILL BE MUCH COOLER THAN THE PREVIOUS DAY...TEMPERATURES STILL
APPEAR TO BE WELL ABOVE NORMAL ON MONDAY. APPEARS AS THOUGH THERE
WILL BE A GENERAL WARMING TREND NEXT WEEK...WITH THE POTENTIAL FOR
80S RETURNING BY WEEKS END.
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
HAD TO MAKE A FEW QUICK CHANGES. WIDESPREAD MVFR TO IFR CEILINGS CAN
BE EXPECTED ALONG AND EAST IF I29 THROUGH 14Z FRIDAY ALONG WITH
VISIBILITIES BELOW 1 MILE AT TIMES ON FOG. SHOWERS MAY LINGER
THROUGH 08Z EXTREME EASTERN PART OF AREA WELL EAST OF TAF SITES.
OTHERWISE GENERALLY VFR CONDITIONS SHOULD RULE THROUGH 31/06Z. LOCAL
EXCEPTIONS SEEM POSSIBLE IN THE FORM OF 3-5SM IN LIGHT FOG 08Z-13Z.
AM MENTIONING THIS REDUCTION IN HON AND FSD TAFS BUT NTO IN SUX TAF
DUE TO LONGER LINGERING NORTHERLY SURFACE FLOW ALTHOUGH THIO S AREA
AND EAST WILL HAVE THE WEAKEST DRYING. NO OTHER POSSIBLE EXCEPTION
SEEN WITH DRY REGIME DEVELOPING. A FEW CEILINGS AROUND 10K FEET
12Z-31/00Z IS PROBABLY THE WORST CONDITION FORSEEN OTHER THAN THE
ABOVE MENTIONED LIGHT FOG. / WILLIAMS
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ071-072-
080-097.
NE...NONE.
SD...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR SDZ039-040-
054>056.
&&
$$
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
446 AM CDT FRI MAR 30 2012
.SHORT TERM (TODAY THROUGH SATURDAY)...REMNANT MCV IS APPARENT ON
SATELLITE IMAGERY OVER THE WESTERN GULF IN ASSOCIATION WITH
DECAYING CONVECTION THAT LIFTED FROM THE RGV AND TAMAULIPAS INTO
THE OFFSHORE WATERS. WEAK SUBSIDENCE WILL TAKE PLACE THIS MORNING
IN THE WAKE OF THE MCV. ATMOSPHERE WILL BECOME INCREASINGLY
UNSTABLE AS THE MORNING PROGRESSES INTO AFTERNOON. MODELS SHOW
THIS VERY UNSTABLE AIRMASS TO REMAIN OVER THE REGION TODAY.
FORECAST INSTABILITY FIELDS SHOW CAPE FROM 3500-4000 J/KG OVER THE
INLAND COASTAL PLAINS AND BRUSH COUNTRY THIS AFTERNOON WITH LIFTED
INDEX VALUES AROUND -10 TO -12 DEGREES WITH LIMITED CONVECTIVE
INHIBITION. RAISED POPS TO HIGH END CHANCES OF THUNDERSTORMS
BETWEEN THE PARALLELING HIGHWAY 16 AND HIGHWAY 281 CORRIDOR THIS
AFTERNOON. POTENTIAL FOR ISOLATED STRONG TO SEVERE THUNDERSTORMS
POSSIBLE AGAIN THIS AFTERNOON INTO THE EARLY EVENING AS SEABREEZE
PUSHES WESTWARD. TURNING THE FOCUS OUT WEST TONIGHT...GFS MODEL
INDICATES A STRONG VORT LOBE FORECAST TO MOVE TOWARD THE NUEVO
LEON/COAHUILA/TAMAULIPAS MEXICAN TRI- STATE REGION FRI NIGHT WITH
GOOD PVA...INSTABILITY...AND MOISTURE TO EXIST FOR MCS FEATURE
POSSIBLY DEVELOPING ALONG RIO GRANDE WITH CORFIDI VECTORS
SUGGESTING A TRACK TO THE SOUTHWEST THROUGH THE NIGHT.
HOWEVER...ECMWF...TEXAS TECH WRF AND HRRR NOT AS ROBUST WITH THIS
MCS POTENTIAL. PAINTED 30 TO 50 PERCENT CHANCES OF SHOWERS AND
THUNDERSTORMS MAINLY WEST OF HIGHWAY 281 DURING THE NOCTURNAL
HOURS WHILE STRATIFYING POPS TO THE LOWER SIDE TOWARD THE COAST.
QUIETER WEATHER...WITH MAINLY ISOLATED TO WIDELY SCATTERED
CONVECTION ANTICIPATED SATURDAY IN THE WAKE OF A MID LEVEL SHORT-
WAVE TROF WITH PWATS TRENDING SLIGHTLY LOWER WITH DRIER AIR
STARTING TO WORK INTO THE REGION WITH CAPES STILL REMAINING ABOVE
2500 J/KG. ABOVE NORMAL TEMPERATURES THROUGH THE SHORT TERM PERIOD
WITH BREEZY LATE MORNING AND AFTERNOON WINDS.
&&
.LONG TERM (SATURDAY NIGHT THROUGH WEDNESDAY NIGHT)...DESPITE
WEAKNESS IN FLOW ALOFT STILL EXISTING SATURDAY NIGHT...MODELS
SUGGEST MOISTURE MAY NOT BE AS IMPRESSIVE AS THE LAST FEW DAYS.
PWATS VALUES MAY DROP BELOW 1 INCH BY 12Z SUNDAY SO HAVE OPTED TO
LEAVE THUNDERSTORM CHANCES OUT OF THE FORECAST AT THIS TIME. ANOTHER
WARM DAY CAN EXPECTED ON SUNDAY ACROSS SOUTH TEXAS WITH LOWER/MID
90S IN THE BRUSH COUNTRY TO LOWER 80S ALONG THE COAST. GUIDANCE HAS
BEEN TOO WARM OUT WEST LATELY...AND WITH RECENT RAINS OVER THOSE
LOCATIONS TOOK A FEW DEGREES OFF MOS TEMPS. FOR EARLY NEXT WEEK...
TIMING OF COLD FRONT WILL REMAIN THE MAIN FORECAST CHALLENGE. MODELS
NOW OFFERING UP A CLOSED LOW SOLUTION OVER THE CENTRAL PLAINS STATES
MONDAY AND TUESDAY. COLD FRONT TIMING HAS BEEN SLOWED DOWN WITH THE
00Z RUNS AND HAVE INCORPORATED THIS INTO THE FORECAST...WITH THE GFS
BEING QUICKER THAN THE EURO WITH FROPA OFF THE COAST. FORECAST
CONFIDENCE IS NOT THE HIGHEST IN TIMING OF THE FRONT AND SUSPECT
FURTHER FINE TUNING WILL BE NEEDED. FOR NOW WILL PLACE THE FRONT
ROUGHLY THROUGH THE WESTERN HALF OF THE REGION BY 12Z TUESDAY AND
OFF THE COAST BY 18Z. ANOTHER DAY OF WARM TEMPS IN ADVANCE OF THE
FRONT WILL OCCUR ON MONDAY. INCLUDED SOME LOW END THUNDERSTORM
CHANCES MONDAY AND MONDAY NIGHT AS LIFT/INSTABILITY INCREASES AHEAD
OF UPPER TROUGH/FRONT. TEMPS WILL BE KNOCKED DOWN BY 5 TO 10 DEGREES
FOR TUESDAY AND WEDNESDAY...WITH LOWER 80S OUT WEST TO UPPER 70S
ALONG THE COAST. AS FOR THE LATTER HALF OF THE WEEK...THERE WILL BE
A SLOW RETURN IN MOISTURE AS NORTHEAST-EASTERLY FLOW AT THE SURFACE
BECOMES SOUTHEAST LATE THURSDAY. RIDGING ALOFT WILL LEAD TO PARTLY
CLOUDY SKIES IN THE AFTERNOON...QUIET WEATHER AND A GRADUAL WARMING
TREND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 86 68 86 68 87 / 30 30 20 10 10
VICTORIA 84 67 84 68 85 / 30 20 20 10 10
LAREDO 92 69 93 68 94 / 20 50 20 10 10
ALICE 89 66 89 68 89 / 50 40 30 10 10
ROCKPORT 82 69 80 70 80 / 30 20 20 10 10
COTULLA 87 65 90 67 92 / 30 50 20 10 10
KINGSVILLE 87 68 88 67 88 / 30 30 20 10 10
NAVY CORPUS 81 68 82 69 82 / 30 20 20 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
SC/70...SHORT TERM
TB/78...LONG TERM
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1159 PM CDT THU MAR 29 2012
.DISCUSSION...SEE AVIATION SECTION FOR 06Z TAFS.
&&
.AVIATION...CONVECTIVE DEBRIS CLOUDINESS WILL REMAIN OVER THE
REGION FROM LARGE CONVECTIVE COMPLEX OVER DEEP SOUTH TEXAS. THERE
WILL BE SOME RESIDUAL PRECIP AROUND LAREDO AND POSSIBLY INTO THE
ALICE AREA FOR A COUPLE MORE HOURS. EXPECT MVFR CEILINGS WILL BE
PREVALENT OVER THE COASTAL PLAINS WITH IFR CIGS OVER THE VCT
AREA THROUGH EARLY MORNING. EXPECT IMPROVEMENT IN CEILINGS BY
LATE MORNING AND VFR BY 18Z. MODELS ARE NOT SHOWING MUCH IN THE
WAY OF CONVECTIVE ACTIVITY FOR FRIDAY BUT THINK THERE WILL BE
SOME DEVELOPMENT ON THE SEA BREEZE BOUNDARY IN THE AFTERNOON.
AIR MASS IS EXPECTED TO BE VERY UNSTABLE AGAIN AS IT WAS ON
THURSDAY. MVFR CEILINGS ARE EXPECTED TO MOVE BACK INTO THE
COASTAL PLAINS BY 03Z SATURDAY.
&&
.PREV DISCUSSION... /ISSUED 910 PM CDT THU MAR 29 2012/
DISCUSSION...AS THE MESOSCALE CONVECTIVE VORTEX LIFTED INTO
SOUTHEAST TEXAS LATE THIS AFTERNOON...AIR MASS BECAME STRONGLY
UNSTABLE OVER THE COASTAL PLAINS WITH LIFTED INDECES AROUND -10
DEGREES AND CAPE VALUES AROUND 3000 J/KG. STRONG TO SEVERE
STORMS DEVELOPED ALONG THE SEA BREEZE WITH THE MOST SEVERE
AFFECTING ROBSTOWN WITH DAMAGING WINDS AND HAIL UP TO 2 INCHES.
MOST OF THE ACTIVITY DIMINISHED WITH THE LOSS OF HEATING AND
WEAK STABILIZATION BEHIND THE SEA BREEZE. BUT MORE ACTIVITY
LINGERING OVER DEEP SOUTH TEXAS HAS SHOWN A DRIFT TO THE
NORTHEAST AHEAD OF AN UPPER LEVEL SHORT WAVE TROUGH NORTH
OF MONTERREY MOVES EAST-NORTHEAST. WILL MODIFY POPS TO SHOW
BEST CHANCES FROM SOUTHWEST TO LIMITED NORTHEAST AND OVER THE
GULF WATERS. MODELS SHOW THIS VERY UNSTABLE AIRMASS TO REMAIN
OVER THE REGION FOR FRIDAY. FORECAST INSTABILITY FIELDS SHOW
CAPE FROM 3500-4000 J/KG OVER THE INLAND COASTAL PLAINS AND
BRUSH COUNTRY WITH LIFTED INDEX VALUES AROUND -11 TO -12
DEGREES WITH LIMITED CONVECTIVE INHIBITION. RAISED POPS TO
LOW END CHANCE OVER MOST OF THE BRUSH COUNTRY TO INLAND COASTAL
PLAINS FRIDAY AFTERNOON. POTENTIAL FOR ISOLATED SEVERE
THUNDERSTORMS AGAIN TOMORROW AFTERNOON INTO THE EVENING.
PREV DISCUSSION... /ISSUED 642 PM CDT THU MAR 29 2012/
DISCUSSION...SEE AVIATION SECTION BELOW.
AVIATION...ONGOING CONVECTION ALONG A SEA BREEZE THIS AFTERNOON
WILL CONTINUE TO MOVE SLOWLY WEST THRU THE EVENING HOURS. AREAS
AHEAD OF AND IN THE WAKE OF THE SEA BREEZE ARE GENERALLY VFR.
THESE STORMS ARE EXPECTED TO DIMINISH OVER THE NEXT TWO TO THREE
HOURS...HOWEVER THUNDERSTORMS ACROSS MEX ARE EXPECTED TO AFFECT
LRD LATER THIS EVENING TOWARD MIDNIGHT. THIS SYSTEM IS EXPECTED TO
GENERALLY MOVE E TO SE OVERNIGHT ACROSS S TX. GENERALLY MVFR CIGS
ARE EXPECTED TO DVLP OVERNIGHT WITH IFR/LIFR CONDITIONS IN AND
NEAR TSRA`S. ONCE THIS STORM SYSTEM HAS EXITED THE AREA...VFR
CONDITIONS ARE EXPECTED TO DVLP BY FRI AFTERNOON.
PREV DISCUSSION... /ISSUED 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 69 86 68 86 68 / 40 30 30 20 10
VICTORIA 67 84 67 84 68 / 20 20 20 20 10
LAREDO 68 92 69 93 69 / 50 20 50 10 10
ALICE 68 89 66 89 68 / 50 30 40 10 10
ROCKPORT 69 82 69 80 70 / 20 20 20 20 10
COTULLA 67 86 65 88 67 / 40 30 50 10 10
KINGSVILLE 69 87 68 88 67 / 50 30 30 20 10
NAVY CORPUS 71 81 68 82 69 / 30 20 20 20 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TMT/89...SHORT TERM/AVIATION
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
329 AM CDT FRI MAR 30 2012
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
329 AM CDT FRI MAR 30 2012
MAIN FORECAST CONCERNS ARE ON CLOUDS THROUGH SATURDAY MORNING AS
WELL AS TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED TROUGHING OVER THE NORTHEAST PACIFIC INTO SOUTHWEST
CANADA...WEAK RIDGING OVER ONTARIO...THEN TROUGHING IN SOUTHEAST
CANADA. SOUTH OF THE WEAK RIDGING...THERE WERE A FEW SHORTWAVES
MOVING THROUGH A NEARLY ZONAL FLOW. THE FIRST AND MOST SIGNIFICANT
ONE STRETCHED FROM NORTHEAST MINNESOTA INTO WESTERN IOWA. DPVA FROM
THIS SHORTWAVE COMBINED WITH NUMEROUS OTHER FAVORABLE PRECIPITATION
MECHANISMS WERE HELPING TO PRODUCE SHOWERS OVER MUCH OF THE FORECAST
AREA. SOME OF THE MECHANISMS INCLUDE: RIGHT ENTRANCE REGION SUPPORT
OF A 90-100 KT JET AT 200-225MB OVER NORTHERN WISCONSIN AND UPPER
MICHIGAN PER RUC ANALYSIS...ISENTROPIC LIFT/WARM ADVECTION JUST
NOTED FROM A 30-40 KT JET AT 850MB FROM LA CROSSE INTO NORTHERN
MISSOURI PER PROFILER DATA...AND A MOISTURE STREAM INDICATED BY
PRECIPITABLE WATER VALUES OF 0.75 TO 1.2 INCHES EXTENDING FROM THE
FORECAST AREA SOUTHWEST INTO MISSOURI. SCATTERED THUNDERSTORMS HAVE
ALSO OCCURRED...MAINLY SOUTH OF I-90 WHERE MUCAPE VALUES HAVE BEEN
UP AROUND 300 J/KG. ALONG AND NORTH OF I-94 WHERE TEMPERATURES ARE
IN THE LOW TO MID 30S...RESULTING FROM A COOLING AND DRYING EASTERLY
FLOW...PRECIPITATION IN THE FORMS OF RAIN...SLEET AND SNOW HAVE
OCCURRED. OTHER SHORTWAVES OF NOTE ON WATER VAPOR WITH MUCH LESS
GOING ON WERE PRESENT OVER WESTERN SOUTH DAKOTA AND FROM NORTHWEST
MINNESOTA INTO EASTERN MANITOBA. THE REASON FOR THE LACK OF ACTIVITY
WITH THESE WAVES IS MID-LEVEL DRYING...SEEN ON THE 00Z BIS...UNR AND
ABR SOUNDINGS. CLEARING LINE IS WELL OFF TO THE WEST...ALONG THE
DAKOTAS/MINNESOTA BORDER.
TODAY AND TONIGHT...CURRENT SHORTWAVE COMING INTO THE WESTERN
PORTION OF THE FORECAST AREA IS PROGGED TO MOVE ACROSS THE AREA
QUICKLY THIS MORNING...REACHING LAKE MICHIGAN BY 18Z. WITH THE FAST
PROGRESSION OF THE SHORTWAVE...ANTICIPATING ALL PRECIPITATION TO END
BY 15Z...AS PREVIOUS FORECASTS HAVE SUGGESTED. NEXT SHORTWAVE OVER
WESTERN SOUTH DAKOTA FOLLOWS QUICKLY ON ITS HEELS...CROSSING THE
FORECAST AREA LATE THIS AFTERNOON INTO THE EVENING...WITH WEAK UPPER
RIDGING THEN BUILDING IN AFTER MIDNIGHT. GIVEN LACK OF ANY ACTIVITY
UPSTREAM WITH THIS SHORTWAVE...ENVISION IT SHOULD COME THROUGH DRY.
IN FACT...THE MORE PROBLEMATIC ISSUE THROUGH TONIGHT IS CLOUD COVER.
SUBSIDENCE IN THE WAKE OF THIS MORNINGS SHORTWAVE...COMBINED WITH
RECENT MOISTURE AND AN EASTERLY LOW LEVEL FLOW...ALL WOULD SUGGEST A
CLOUDY-TYPE FORECAST IS THE WAY TO GO. DAYTIME MIXING SHOULD BE ABLE
TO GRADUALLY BREAK UP CLOUDS SOMEWHAT WEST OF THE MISSISSIPPI RIVER
THIS AFTERNOON. SOME HINTS THAT THIS CLEARING MAY SPREAD EAST INTO
WISCONSIN AFTER MIDNIGHT TONIGHT...RESULTING FROM PERSISTENT
SUBSIDENCE. ON THE OTHER HAND...CEILINGS COULD JUST LOWER INSTEAD.
ANOTHER ISSUE...WITH THAT RIDGING MOVING IN LATER TONIGHT...WARM
ADVECTION MID-CLOUDS LOOK TO RE-ENTER THE PICTURE...ESPECIALLY WEST
OF THE MISSISSIPPI RIVER. IN ADDITION...AM CONCERNED THAT LOW
STRATUS COULD RE-DEVELOP WHERE SKIES CLEAR WEST OF THE MISSISSIPPI
RIVER...RESULTING FROM RADIATIONAL COOLING AND AN UPSLOPING
SOUTHEAST WIND DEVELOPING. GIVEN THE CLOUD CONCERNS...GENERALLY TOOK
A BLEND OF ALL GUIDANCE FOR BOTH HIGHS AND LOWS. CONCERN DOES EXIST
THAT CENTRAL WISCONSIN ZONES COULD SEE FROST TONIGHT...BUT CLOUD
COVER ISSUES PRECLUDE ISSUING ANY ADVISORY AT THIS TIME.
SATURDAY AND SATURDAY NIGHT...THE WEAK UPPER RIDGING BUILDING OVER
THE AREA LATE FRIDAY NIGHT LOOKS TO CONTINUE INTO SATURDAY...
RESPONDING TO A POTENT SHORTWAVE TRACKING INTO NORTHERN ONTARIO.
UPPER RIDGING THEN RE-BUILDS BACK TO THE WEST OVER THE DAKOTAS
RESULTING FROM A DEEP SHORTWAVE TROUGH MOVING THROUGH CALIFORNIA.
DAYTIME MIXING IN CONJUNCTION WITH SUBSIDENCE UNDER THE WEAK UPPER
RIDGE SHOULD HELP BUST UP ANY MORNING LOW LEVEL STRATUS.
HOWEVER...BEING IN A WARM ADVECTION PATTERN AM CONCERNED THERE COULD
BE SOME LOW/MID CLOUDS TO DEAL WITH. BOTH THE NAM/GFS SHOW THESE
AROUND 800MB IN THE RH FIELDS...IN A NORTH-SOUTH BAND THAT MOVES
WEST TO EAST ACROSS THE FORECAST AREA THROUGH THE DAY. IN FACT...IF
YOU LIFT A PARCEL FROM 800MB IN THIS BAND...CAPE VALUES OF 300-500
J/KG ARE OBTAINABLE WITH NO CIN. ALTHOUGH NEITHER THE 30.00Z
GFS...NAM OR REGIONAL CANADIAN PRODUCE ANY QPF FROM THIS BAND...FEEL
COMPELLED TO HAVE SOME 20 PERCENT CHANCES. ACTUALLY...THE 30.00Z
UKMET PRODUCES A LITTLE LIGHT QPF. ON SATURDAY NIGHT...ANOTHER SURGE
OF ISENTROPIC LIFT NOTED ON 295-305K SURFACES IS PROGGED TO MOVE
INTO/THROUGH THE AREA. THE UKMET IS BY FAR THE MOST BULLISH WITH
CONVECTION...THOUGH THE HEAVIEST PORTION IS CENTERED OVER NORTHERN
ILLINOIS. THE 30.00Z GFS/NAM BOTH DEVELOP CONVECTION...MAINLY OVER
THE SOUTHEAST HALF BETWEEN 06-12Z SUNDAY. EITHER WAY...SOME
PRECIPITATION CHANCES ARE WARRANTED...WHICH HAVE BEEN RAISED ABOUT
10 PERCENT FROM THE PREVIOUS FORECAST. WITH MORE CLOUDS TO DEAL WITH
ON SATURDAY AND 925MB TEMPS ONLY REACHING 10-14C BY 00Z...LOWERED
HIGHS 3-4 DEGREES. CONTINUOUS WARM ADVECTION THROUGH MUCH OF
SATURDAY NIGHT SHOULD HELP TO KEEP TEMPERATURES UP AND PREVIOUS
FORECAST LOWS SEEM REASONABLE.
SUNDAY AND SUNDAY NIGHT...UPPER RIDGING OVER THE NORTHERN PLAINS IS
EXPECTED TO GRADUALLY SHIFT EAST...MOVING OVER THE FORECAST AREA
SUNDAY NIGHT. AGAIN...THIS IN RESPONSE TO THE DEEP TROUGHING OVER
THE WESTERN U.S. SLOWLY MOVING EAST. THIS UPPER RIDGE IS STRONGER
THAN THE PREVIOUS COUPLE ONES MOVING THROUGH...SO ITS SUBSIDENCE
SHOULD BE STRONGER. INDEED...MOST MODELS KEEP THE FORECAST AREA DRY
THROUGH SUNDAY NIGHT AND HAVE TRENDED THE FORECAST IN THIS
DIRECTION. THIS LEAVES TEMPERATURES THE BIGGER ISSUE. WITH A MORE
AMPLIFIED LOOK TO THE UPPER RIDGING...THAT WARM FRONT MENTIONED IN
PREVIOUS DISCUSSIONS TO COME THROUGH ON SUNDAY MAY END UP STAYING
ALONG OR SOUTH OF I-90. IN FACT...THE 30.00Z GFS/UKMET HINT AT
BACKDOOR COLD FRONT POTENTIAL. STILL...IT SEEMS LIKE A SOLID BET FOR
SUNDAY TO END UP QUITE A BIT WARMER THAN SATURDAY...ESPECIALLY WEST
OF THE MISSISSIPPI RIVER WHERE 925MB TEMPERATURE CONSENSUS SUGGESTS
READINGS OF 20-22C. CLOSER TO CENTRAL WISCONSIN...14-16C READINGS
SHOULD BE MORE COMMON. WITH THE COOLER TREND NOTED IN MODELS...DID
KNOCK HIGHS BACK A FEW DEGREES OVER WISCONSIN AREAS. FURTHER
LOWERING MAY BE REQUIRED DEPENDING ON THE BACKDOOR COLD FRONT
POTENTIAL. WARM AIR SHOULD HOLD IN HERE SUNDAY NIGHT...IN
COMBINATION WITH THE UPPER RIDGE AND WITH A LOW PRESSURE SYSTEM
TRYING TO APPROACH THE AREA FROM THE CENTRAL PLAINS. PREVIOUS LOW
TEMPERATURE FORECAST LOOKS ON TRACK.
.LONG TERM...MONDAY THROUGH THURSDAY NIGHT
329 AM CDT FRI MAR 30 2012
TREND IN THE RECENT 30.00Z GFS/ECMWF/UKMET/CANADIAN IS TO SUGGEST
THAT THE WESTERN TROUGHING IS GOING TO SPLIT INTO TWO. THE SOUTHERN
END CUTS OFF OVER TEXAS FOR MUCH OF THE LONG TERM PERIOD...WHILE THE
NORTHERN END COMES THROUGH THE FORECAST AREA ON TUESDAY. THIS IS
SLOWER THAN PREVIOUSLY FORECAST...AND IN FACT IF THE 30.00Z ECMWF IS
CORRECT...MONDAY COULD BE A VERY WARM AND EVEN HUMID DAY ACROSS MUCH
OF THE FORECAST AREA. SUGGESTION FROM THE MODEL IS HIGHS IN THE LOW
80S AND DEWPOINTS IN THE LOW 60S...ALL FROM THE LOW PRESSURE SYSTEM
IN THE CENTRAL PLAINS LIFTING NORTHEAST INTO NORTHWEST WISCONSIN.
HAVE NOT JUMPED ON THIS SCENARIO QUITE YET...SINCE MOST MODELS KEEP
THIS SYSTEM TO THE SOUTH OF THE AREA...BUT DEFINITELY WARRANTS
WATCHING. ALSO THE ECMWF WOULD SUGGEST SOME STRONG CONVECTION AT
LEAST AS THE COLD FRONT COMES THROUGH. NEEDLESS TO SAY...CHANCES OF
PRECIPITATION CONTINUE IN THE FORECAST FOR MONDAY INTO MONDAY
NIGHT...MAINLY IN THE 20-40 RANGE UNTIL THIS WHOLE SYSTEM CAN BE
IRONED OUT. DRYING TREND THEN IS FORECAST FOR TUESDAY AND CONTINUING
THROUGH THE REST OF THE LONG TERM PERIOD WITH MOST MODELS AND
ENSEMBLES SHOWING NORTHWEST FLOW OVER THE FORECAST AREA. DID KEEP A
20 PERCENT CHANCE OF SHOWERS GOING ON TUESDAY WITH THE UPPER TROUGH
MOVING THROUGH...THOUGH. HOW MUCH NORTHWEST FLOW AND THE COLD AIR
ASSOCIATED WITH IT VARIES...SO FOR NOW STAYED WITH A BLEND OF MODELS
FOR TEMPERATURES. READINGS STILL LOOK TO STAY ABOVE NORMAL AS HIGHS
ONLY DROP INTO THE MID TO UPPER 50S AT THE LOWEST. NORMAL HIGHS ARE
IN THE LOW 50S.
&&
.AVIATION...THROUGH 06Z SATURDAY
1201 AM CDT THU MAR 29 2012
A MID LEVEL SHORTWAVE TROUGH WAS MOVING INTO WESTERN MINNESOTA
LATE THIS EVENING. THE ATTENDANT SURFACE LOW WAS LOCATED OVER
NORTHEAST KANSAS/SOUTHEAST NEBRASKA. MOISTURE TRANSPORT AHEAD OF
THE LOW WAS SPAWNING SHOWERS AND THUNDERSTORMS FROM IOWA INTO
MINNESOTA. THE STRONGEST STORMS WERE LOCATED OVER SOUTHERN IOWA.
THUS FAR CEILINGS HAVE REMAINED IN THE VFR CATEGORY AT THE TAF
SITES. HOWEVER...AS LOW LEVEL MOISTURE CONTINUES TO
INCREASE...SHOWERS WILL BECOME MORE NUMEROUS AND BUFKIT SOUNDINGS
FROM BOTH THE 30.02 RUC AND 30.00Z NAM SHOWS LOW LEVEL SATURATION
TAKING PLACE THROUGH THE NIGHT. THUS EXPECT CEILINGS TO FALL INTO
THE MVFR CATEGORY...AND EVEN INTO THE IFR CATEGORY AT KRST. THE
SHOWERS WILL END AROUND 14-15Z FRIDAY...BUT ALTHOUGH CEILINGS WILL
SLOWLY RISE...MODELS SUGGEST THEY WILL STAY IN THE MVFR CATEGORY
FOR MUCH OF THE DAY...RISING INTO THE VFR CATEGORY LATE IN THE
DAY. STILL UNCERTAINTY WITH CLEARING TREND FRIDAY EVENING BETWEEN
00Z-06Z. NAM CONTINUES TO SHOW QUITE BIT OF LOW LEVEL MOISTURE.
DID SCATTERED THE CLOUDS OUT AT KRST...BUT KEPT A BROKEN VFR
CEILINGS AT KLSE THROUGH 06Z.
&&
.HYDROLOGY...
329 AM CDT FRI MAR 30 2012
AS OF 3 AM...MAJORITY OF THE PRECIPITATION SO FAR HAS FALLEN
ALONG AND SOUTH OF A LINE FROM ST ANSGAR IOWA TO WINONA MN AND
BLACK RIVER FALLS WISCONSIN. RADAR ESTIMATES SHOW THAT THE SHOWERS
AND THUNDERSTORMS PRODUCED AMOUNTS RANGING FROM 0.25 TO 0.75
INCHES. HOWEVER...THERE IS AN AREA COVERING SOUTHEAST
FAYETTE...MUCH OF CLAYTON AND NORTHERN GRANT COUNTIES WHERE 0.75
TO 1.75 INCHES FELL...HIGHEST NEAR STRAWBERRY POINT. NO REPORTS OF
ANY FLOODING THUS FAR BUT EXPECT SOME BRIEF RISES IN SMALL
STREAMS. WILL HAVE TO KEEP AN EYE ON THE TURKEY RIVER...THOUGH
THE LACK OF SIGNIFICANT RAINFALL AND GENERALLY DRY SOILS SHOULD
KEEP THE RIVER BELOW FLOOD STAGE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
328 AM CDT FRI MAR 30 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1201 AM CDT FRI MAR 30 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 06Z SATURDAY
1201 AM CDT THU MAR 29 2012
A MID LEVEL SHORTWAVE TROUGH WAS MOVING INTO WESTERN MINNESOTA
LATE THIS EVENING. THE ATTENDANT SURFACE LOW WAS LOCATED OVER
NORTHEAST KANSAS/SOUTHEAST NEBRASKA. MOISTURE TRANSPORT AHEAD OF
THE LOW WAS SPAWNING SHOWERS AND THUNDERSTORMS FROM IOWA INTO
MINNESOTA. THE STRONGEST STORMS WERE LOCATED OVER SOUTHERN IOWA.
THUS FAR CEILINGS HAVE REMAINED IN THE VFR CATEGORY AT THE TAF
SITES. HOWEVER...AS LOW LEVEL MOISTURE CONTINUES TO
INCREASE...SHOWERS WILL BECOME MORE NUMEROUS AND BUFKIT SOUNDINGS
FROM BOTH THE 30.02 RUC AND 30.00Z NAM SHOWS LOW LEVEL SATURATION
TAKING PLACE THROUGH THE NIGHT. THUS EXPECT CEILINGS TO FALL INTO
THE MVFR CATEGORY...AND EVEN INTO THE IFR CATEGORY AT KRST. THE
SHOWERS WILL END AROUND 14-15Z FRIDAY...BUT ALTHOUGH CEILINGS WILL
SLOWLY RISE...MODELS SUGGEST THEY WILL STAY IN THE MVFR CATEGORY
FOR MUCH OF THE DAY...RISING INTO THE VFR CATEGORY LATE IN THE
DAY. STILL UNCERTAINTY WITH CLEARING TREND FRIDAY EVENING BETWEEN
00Z-06Z. NAM CONTINUES TO SHOW QUITE BIT OF LOW LEVEL MOISTURE.
DID SCATTERED THE CLOUDS OUT AT KRST...BUT KEPT A BROKEN VFR
CEILINGS AT KLSE THROUGH 06Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
346 PM CDT THU MAR 29 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1125 AM EDT FRI MAR 30 2012
.UPDATE...
CONVECTIVE TRENDS CONTINUE TO BE MONITORED ACROSS THE AREA.
ELEVATED SHOWERS AND EMBEDDED STORMS WERE PERSISTING EITHER SIDE
OF THE IN/OH/MI STATE LINES WITH SPORADIC REPORTS OF PEA SIZE
HAIL. THIS ACTIVITY SHOULD REMAIN BELOW SEVERE LEVELS AS IT
CONTINUES TO MOVE EAST.
ONE STORM HAS DEVELOPED ON THE SW PART OF THIS AREA OF RAIN AND
HAS BEEN SHOWING SIGNS OF SOME ORGANIZATION. RADAR DATA AND SFC
OBS INDICATE IT IS LIKELY STILL ELEVATED BUT MAY BECOME SFC BASED
OVER THE NEXT COUPLE OF HOURS WITH WARM SECTOR RAPIDLY EXPANDING
NE TOWARDS SOUTHERN PARTS OF THE AREA. TEMP/DEWPTS HAVE BEEN
INCREASE DRAMATICALLY ACROSS CENTRAL AND EC ILLINOIS WHERE NEAR 60
DEWPTS HAVE ALREADY ARRIVE SW OF CMI. RUC13 AND NEW NAM
SUGGEST THAT SOUTHERN THIRD TO HALF IS LIKELY IN BEST POSITION
FOR STRONG TO SEVERE STORMS WITH SFC BASED LI`S -4 TO -8 C AND
CAPES IN EXCESS OF 1000 J/KG. ADDITIONAL CONCERN LIES WITH MODELS
SHOWING A FAIR AMOUNT OF ELEVATED INSTABILITY WITH SHOW WALTER
VALUES ON THE -2 TO -4 C EVEN INTO THIS AFTERNOON.
IN TERMS OF TEMPS...WILL LOOK AT 16Z OBS AND SEE HOW TRENDS ARE IN
FAR SOUTHERN AREAS. GIVEN AMOUNT OF CLEARING AHEAD OF ANTICIPATED
LINE...A FEW 70S ARE POSSIBLE SOUTH OF US 24.
&&
.PREV DISCUSSION... /ISSUED 657 AM EDT FRI MAR 30 2012/
AVIATION.../12Z TAFS/
SFC LOW PRESSURE REMAINS RATHER BROAD AND DISORGANIZED ACROSS NW
IL AND IA THIS MORNING. AREA OF TSTMS E-NE OF THE LOW HAS
CONTINUED TO SLOWLY WKN AS IT MOVED EAST ACROSS NERN IL AND SRN
LM...BUT SOME BACK-BUILDING TOWARD NW IL IN PAST HOUR. THIS AREA
OF SHRA/TS SHOULD MOVE EAST AHEAD OF THE SFC LOW THIS MORNING SO
MAINTAINED PREV SBN TAF FCST OF TEMPO TSRA 13Z-17Z. LATEST HIGH RES
GUIDANCE CONTS TO SUGGEST LOW WL DEEPEN AS IT MOVES ESE TODAY
ALLOWING AIRMASS TO DESTABILIZE OVER NE INDIANA THIS AFTN AHEAD OF
THE SYSTEMS CDFNT. THIS SHOULD RESULT LINE OF TSRA DVLPG TO THE
WEST OF FWA THIS AFTN AND IMPACTING THE TERMINAL 19Z-22Z. SOME
-RA/DZ AND MVFR CIGS SHOULD PERSIST AS THE LOW MOVES TO THE EAST
TONIGHT.
PREV DISCUSSION... /ISSUED 444 AM EDT FRI MAR 30 2012/
SHORT TERM.../TODAY THROUGH SAT NGT/
BROAD SFC LOW OVER IA/SWRN MN THIS MORNING EXPECTED TO CONSOLIDATE
AND DEEPEN AS IT MOVES ESE THROUGH A CHICAGO-FWA-LIMA LINE TODAY.
LARGE CLUSTER OF TSTMS TO E-NE OF THE SFC LOW IN AREA OF LOW LEVEL
THETA-E ADVECTION AND UPR LEVEL DIV. IR IMAGERY SHOWING TREND OF WARMING
OF CLOUD TOPS IN THIS AREA... BUT NEW CONVECTION DVLPG FARTHER
EAST ACROSS NW INDIANA. EXPECT MUCH OF THE CWA WILL HAVE SHOWERS
AND TSTMS THIS MORNING...BUT GREATEST COVERAGE BTWN 12Z-18Z
EXPECTED TO BE ACROSS NW 1/2 OF CWA ASSOCIATED WITH TSTM CLUSTER
CURRENTLY MOVG THROUGH NW IL/SW WI.
TRACK OF SFC LOW ACROSS THE AREA TODAY SHOULD RESULT IN A LARGE
TEMP GRADIENT WITH 40S IN OUR MI COUNTIES AND NR 70 IN THE SRN
TIER OF OUR INDIANA COUNTIES THIS AFTN. NAM AND LOCAL 12KM WRF
INDICATE MODERATE INSTABILITY WILL DVLP OVER SRN PORTION OF OUR
CWA THIS AFTN WITH 1000-1500J/KG MLCAPE AND RATHER STRONG 0-6KM
SHEAR OF 30-40KT. SPC 4KM WRF SUGGESTS TSTMS WILL DEVELOP ALONG
THE CDFNT THIS AFTN AS IT MOVES THROUGH THIS ENVIRONMENT ACROSS
SRN PORTION OF OUR CWA. DISCREET STORMS EXPECTED TO QUICKLY
TRANSITION INTO A LINE AND RACE EASTWARD ACROSS SRN PORTION OF THE
AREA BETWEEN 18-00Z. CONT TO THINK AREAS ALONG AND SOUTH OF A
RCR-FDY LINE ARE AT GREATEST RISK OF SVR STORMS THIS AFTN... BUT
DEPENDING ON EXACT TRACK OF LOW AND SUBSEQUENT NORTHWARD ADVANCE
OF WARM SECTOR... THREAT COULD EXTEND FARTHER NORTH A COUPLE MORE
COUNTIES INTO NRN INDIANA AND NW OH PER LATEST SPC DAY1 OUTLOOK.
AS LOW CONTS ESE ACROSS THE UPR OH VALLEY TONIGHT... LOW LEVEL CAA
SHOULD RESULT IN WIDESPREAD LOW CLOUDS OVER THE AREA WHICH WILL
PERSIST INTO SATURDAY MORNING. SKIES SHOULD CLEAR SAT AFTN AS SFC
RIDGE MOVES ACROSS THE AREA. DESPITE WK LOW LEVEL FLOW/WAA... EXPECT
AFTN SUNSHINE WILL ALLOW TEMPS TO REACH THE MID/U50S OVER MOST OF
THE CWA. GOOD RADIATIONAL COOLING EARLY SAT NGT SHOULD GIVE WAY TO
INCREASING WAA/CLOUDS/GRADIENT WINDS LATE AS RIDGE MOVES TO THE EAST
AND A WK CDFNT DROPS SE ACROSS THE UPR GRTLKS. GIVEN THIS
SCENARIO...GENERALLY LEANED TOWARD WARMER GUIDANCE VALUES.
LONG TERM...
SUNDAY THROUGH THURSDAY...THE MAIN CHALLENGE THIS PERIOD INCLUDES
THE TIMING AND TRACK OF SHORT WAVE ENERGY EJECTING EAST EARLY NEXT
WEEK. THE PERSISTENT PATTERN OF A NEGATIVE HEIGHT ANOMALY ALONG AND
OFF THE WESTERN COAST OF NORTH AMERICA WILL CONTINUE TO KEEP RATHER
EXTENSIVE UPPER LEVEL RIDGING OVER THE NORTH AMERICAN INTERIOR. FOR
THIS PACKAGE...USED A ECMWF/GFS/CANADIAN GEM ENSEMBLE BLEND WITH
ANALOGS. THE ONGOING CHANCES FOR SHOWERS AND THUNDERSTORMS MONDAY
NIGHT AND TUESDAY APPEAR ON TRACK. IT LOOKS LIKE A PORTION OF THE
SHORT WAVE ENERGY WILL SHEAR OUT TO THE NORTHEAST WITH SOME TYPE OF
CUT OFF LOW LINGERING TO THE SOUTH OR SOUTHWEST OF THE AREA. SEVERE
STORMS ARE PLAUSIBLE GIVEN CAPES APPROACHING 2000 J/KG WITH UPPER
LEVEL SUPPORT. IT HAS BEEN REAL HARD TO TAP MUCH COLD AIR BEHIND
THESE SYSTEMS THE PAST SEVERAL WEEKS. THE BEST CHANCE FOR COLD AIR
AND FREEZING TEMPERATURES IS LATE IN THE PERIOD AS NORTH TO
NORTHEAST FLOW SETS UP WITH A SURFACE RIDGE EXTENDING SOUTH FROM
JUST WEST OF HUDSON BAY. OTHERWISE...WENT WITH THE HIGH END CANADIAN
AND GFS ENSEMBLE MEMBERS WITH HIGHS WELL INTO THE 70S SUNDAY AND
MONDAY GIVEN 850 MB TEMPS 14C TO 17C.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...JT
LONG TERM...SKIPPER
AVIATION...JT
UPDATE...FISHER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
706 AM EDT FRI MAR 30 2012
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 423 AM EDT FRI MAR 30 2012
BROAD AREA OF SHOWERS STRETCHING FROM THE ARROWHEAD OF MN THROUGH
WRN UPPER MI...WRN TWO THIRDS OF WI AND INTO ERN IOWA AT 07Z. OVER
THE ARROWHEAD OF MN AND INTO WRN UPPER MI...SHOWERS HAVE BEEN MAINLY
IN THE FORM OF SNOW. RECENT WEBCAM IMAGES IN IRONWOOD SHOW A DUSTING
OF SNOW ON THE GROUND OVER THE LAST HOUR OR SO. FARTHER SOUTH AND
WEST...STARTING TO SEE A TRANSITION TO RAIN AS THE NOSE OF WARM
AIR AND DRY AIR ALOFT ARE STARTING TO TURN THE PCPN BACK TO RAIN
OVER NW WI. THIS IS ALL RAIN THROUGH THE REST OF WI AND INTO
IOWA...WHERE CONVECTION DEVELOPED DURING THE EVENING AND HAS SPREAD
NE. THE PCPN IS ASSOCIATED WITH A SHORTWAVE MOVING THROUGH THE
CNTRL/NRN PLAINS STATES...WHILE A SFC LOW IS TRACKING THROUGH NRN
MO AND SRN IOWA.
PCPN FOR THIS MORNING IS THE MAIN FEATURE OF CONCERN FOR THE SHORT
TERM FORECAST. THE NRN PART OF THE PCPN AREA IS THE INITIAL AREA OF
CONCERN. THIS SHOULD CONTINUE TO THE E OVER THE NEXT SEVERAL
HOURS...BUT WITH THE MID-LOW LVL DRY AIR IN PLACE...EXPECT THIS TO
EAT AWAY AT THE PCPN AS IT MOVES OUT OF WRN UPPER MI. THIS
DIMINISHING TREND WILL ALSO BE DUE TO THE FORCING FOCUSING FARTHER
S OVER CNTRL WI...ASSOCIATED WITH THE RIGHT REAR OF THE UPPER JET
AND H850-700 WAA. THIS REFOCUSING HAS BEEN SEEN ON RADAR OVER THE
LAST HOUR...WITH SHOWERS BECOMING MORE WIDESPREAD OVER CNTRL/SRN
WI.
THE QUESTION WITH THE SRN AREA OF PCPN WILL BE HOW FAR N IT
WILL TRACK. MODELS CONSISTENT ON THE H925-850 WAA REMAINING OVER THE
SE HALF OF WI AND THE ONLY THING REALLY GOING FOR SOME PCPN FARTHER
TO THE N IS SOME H850-700 FGEN OVER THE SCNTRL. LOOKING AT FGEN
CROSS-SECTIONS OVER THE CWA...THAT AREA IS UNDER THE ASCENDING
BRANCH OF FGEN. OTHERWISE...IT SEEMS LIKE MUCH OF REST OF THE AREA
WILL BE ON THE DESCENDING BRANCH OF THE FGEN. THIS SUPPORTS A
DIMINISHING TREND THE MODELS SHOW WITH THE NRN PCPN AREA AND
THINK THAT LLVL DRY ERLY FLOW WILL COMBINE TO LIMIT THE PCPN FROM
GOING TOO FAR EAST OF A LINE FROM KMQT/KESC. THUS...HAVE DIMINISHED
POPS OVER THE E TO JUST SLIGHTS. FOR THE STRONGER PCPN AREA...00Z
MODEL RUNS...ALONG WITH THE HOURLY RUC RUNS...ALL SHOW THIS STRONGER
PCPN JUST BRUSHING THE SCNTRL CWA AND CORRELATES WELL WITH THE FGEN.
AS FOR PCPN AMNTS...THE DIMINISHING TREND OVER THE N SHOULD KEEP
LIQUID AMNTS LIGHT. ALONG THE WI BORDER...COULD SEE AMNTS IN THE
0.1 TO 0.2 RANGE...WITH THE HIGHEST AMNTS NEAR THE CITY OF
MENOMINEE. 29/21Z SREF SUPPORTS THAT SOLN AND SHOWING BEST CHANCES
OF 0.1IN ALONG THE WI BORDER AND MAINLY NEAR MENOMINEE...SO FEEL
THAT IS THE WAY TO GO. RUC/NAM SOUNDINGS SHOW THE PCPN FALLING AS
SNOW FOR THE FIRST HOUR OR TWO OF PCPN...BUT THEN START
TRANSITIONING TO A -RA/DZ THROUGH THE MORNING HOURS FROM W TO E.
THIS IS DUE TO DRIER AIR ALOFT MOVING INTO THE AREA FROM W TO E
AFTER 12Z. OVER THE FAR WEST...WARMER H875 TEMPS WILL PRODUCE A
QUICKER CHANGE OVER TO RAIN OVER GOGEBIC COUNTY...PROBABLY TOWARDS
DAYBREAK. FORTUNATELY...LLVL TEMPERATURES SHOULD BE WARMING AT THAT
TIME AND LIMIT POTENTIAL FOR FREEZING ON THE SFC. PREVIOUS SHIFT HAD
A GOOD HANDLE ON THIS AND WILL FOLLOW THAT TRANSITION. THUS...SNOW
AMNTS SHOULDN/T BE ANYTHING TOO SUBSTANTIAL. HAVE AROUND AN INCH
FOR THE WI BORDER AREA AND TAPER IT OFF TO A DUSTING OVER THE N. IF
STRONGER PCPN MAKES IT TO MENOMINEE...COULD SEE A HEAVIER BURST OF
SNOW TOWARDS THE MORNING COMMUTE THAT COULD QUICKLY PRODUCE AN INCH
OR TWO OF SNOW. WITH THIS BEING THE FIRST MEASUREABLE SNOW FOR A
WHILE AND IT OCCURRING DURING THE MORNING COMMUTE...WITH CONTINUE
THE SPS FOR THE SCNTRL THROUGH THE MORNING HOURS.
FOR THE REST OF THE DAY...EXPECT THE PCPN TO QUICKLY TRANSITION TO
THE SE WITH THE BETTER LLVL WAA AND END UP PRODUCING A CLOUDY DAY.
HAVE LINGERING SOME LOW POPS FOR SOME LIGHT RAIN SHOWERS AND
DRIZZLE THROUGH THE EARLY AFTN...BUT THEN EXPECT THAT TO COME TO AN
END.
TONIGHT...SFC HIGH PRESSURE RIDGE MOVES BACK INTO THE AREA...BUT
LLVL MOISTURE BELOW H900 REMAINS. THINK THE LOW CLOUDS WILL PERSIST
AND BE THE THICKEST OVER THE CNTRL CWA...WHERE THE LLVL MOISTURE
REMAINS IN PLACE AND H925 TEMPS OF -3C OVER LK MI WILL HELP WITH
SOME LK INSTABILITY. IN ADDITION...LIGHT SE UPSLOPE FLOW WILL HELP
KEEP THE CLOUDS IN PLACE. FARTHER E...DRY ERLY FLOW FROM THE SFC
RIDGE WILL KEEP SKIES MORE PARTLY CLOUDY TOWARDS LUCE COUNTY. OVER
THE FAR W...COULD BE SOME DOWNSLOPE BREAKS IN THE CLOUDS OVER WRN
GOGEBIC/ONTONAGON COUNTIES. WITH THIS LLVL MOISTURE AND UPSLOPE
FLOW...COULD BE SOME -DZ OR LOW CLOUD FOG FROM KMQT/KSAW TO KIMT BUT
OVERALL POTENTIAL SEEMS LIMITED TO MENTION AT THIS POINT.
SATURDAY...SFC HIGH SLIDES E AS STRONG UPPER JET ROUNDING
THE AMPLIFYING UPPER RIDGE MOVES INTO SRN MANITOBA/ONTARIO.
SHORTWAVE ASSOCIATED WITH THIS JET WILL DEVELOP A SFC LOW IN THE
SAME AREA ON SAT. EXPECT LLVL MOISTURE TO BE LINGERING INTO THE
MORNING. DIURNAL MIXING AND WINDS BACKING TO THE S SHOULD
ALLOW FOR THE LOW CLOUDS TO BREAK UP TOWARDS MID DAY...WITH THEM
HANGING ON THE LONGEST OVER THE UPSLOPE CNTRL CWA.
AS THE LOW CLOUDS DIMINISH...MID CLOUDS WILL BEGIN MOVING IN
AHEAD OF THE SHORTWAVE AND UNDER THE INCREASING WAA...ESPECIALLY
OVER THE NW HALF OF THE CWA. MOISTURE IS MARGINAL...AND BEST FORCING
FROM THE SHORTWAVE IS IN CANADA...SO DON/T THINK THE CHANCES OF PCPN
DEVELOPING IS TOO HIGH BUT WILL CONTINUE TO MENTION SLIGHTS. DID
BRING THE POPS A LITTLE FARTHER S TO COVER THE KEWEENAW PENINSULA.
LOWERED TD VALUES SOME OVER THE FAR ERN CWA...WHERE THERE WILL BE
GREATER MIXING WITH LESS CLOUDS AND DRIER AIR CLOSER TO THE SFC
RIDGE. DIDN/T GO AS LOW AS NAM/ECMWF ML DEWPOINT VALUES...IN THE
MID TEENS...BUT LOWERED INTO THE LOWER 20S. WARMEST HIGHS WILL
BE OUT WEST...WHERE THE SRLY FLOW WILL PULL H875 TOWARDS 10C.
WON/T MIX QUITE THAT HIGH...BUT SHOULD MIX BETWEEN THERE AND
H900...WHICH WOULD PRODUCE HIGHS IN THE UPPER 50S TO NEAR 60. IF IT
COULD MIX SLIGHTLY HIGHER...WOULD EASILY HAVE TEMPS IN THE MID 60S.
FARTHER E...THE LINGERING LOW CLOUDS IN THE MORNING WILL LIMIT THE
WARM UP...ALONG WITH COOLER H900 TEMPS LINGERING UNDER THE INITIAL
ESE FLOW. TEMPS OVER THE CNTRL/EAST WILL DEPEND ON HOW QUICKLY THE
WARMER AIR ALOFT ARRIVES IN THE AFTN...BUT THE BREAKS TOWARDS MID
DAY WILL PRODUCE HIGHS IN THE MID 40S TO LOWER 50S.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 423 AM EDT FRI MAR 30 2012
GFS SHOWS A RIDGE BUILDING INTO THE AREA ON SUNDAY WITH A SHORTWAVE
PASSING BY TO THE NORTH SAT NIGHT. A WARM FRONT COMES THROUGH ON
SUNDAY NIGHT WITH TROUGHING MOVING IN FOR MONDAY. THIS WILL CONTINUE
TO BE QUITE ACTIVE THIS PERIOD WITH PCPN CHANCES OVER THE NORTH AND
EAST SAT NIGHT AND THEN OVER THE AREA FOR SUNDAY NIGHT AND MONDAY.
WENT WITH CHANCE POPS FOR THESE TIME PERIODS. OVERALL...DID NOT MAKE
TOO MANY CHANGES TO THE GOING FORECAST FOR TEMPERATURES OR WEATHER.
IN THE EXTENDED...ABOVE NORMAL TEMPERATURES CONTINUE...BUT
CONFIDENCE IS FAIRLY LOW AS POSITION OF FRONTS COULD BE TRICKY FOR
HIGH TEMPERATURES. IF THE WARM FRONT AND WARM SECTOR PART OF THE
STORM MAKES IT THROUGH THE AREA...COULD BE VERY WARM. RIGHT
NOW...GFS AND ECMWF TAKE SFC LOW PRESSURE TO THE SOUTH AND KEEP THE
AREA MORE TOWARDS THE COLDER PART OF THE STORM. CHANCE POPS CONTINUE
MONDAY INTO TUESDAY BEFORE DRY WEATHER MOVES IN FOR TUE NIGHT AND
LASTS INTO THURSDAY AS TROUGHING CONTINUES TO THE EAST OF THE AREA
WITH UPPER LEVEL RIDGING TO THE WEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 705 AM EDT FRI MAR 30 2012
UPPER LEVEL DISTURBANCE MOVING ACROSS WISCONSIN AND SOUTHERN UPPER
MICHIGAN WILL BRUSH KCMX/KSAW WITH -SN AT THE START OF THE TAF
PERIOD. SHOULD SEE VSBYS IMPROVING QUICKLY THIS MORNING AS THE SNOW
CONTINUES IT/S DIMINISHING TREND. HAVE LINGERED IFR CIGS AT KCMX
THROUGH THE MORNING HOURS DUE TO FAVORABLE UPSLOPE FLOW AND
MOISTENING FROM THE SNOW. OTHERWISE...EXPECT MVFR CIGS AT THE REST
OF THE SITES THROUGH THE AFTN.
TONIGHT...LOW LEVEL MOISTURE WILL LIKELY REMAIN TONIGHT AND LEAD TO
LOWERING MVFR CIGS AT ALL THREE SITES. KSAW WILL HAVE THE BEST
CHANCE OF SEEING IFR CIGS WITH UPSLOPE SERLY FLOW. KCMX
ALSO WILL HAVE FAVORABLE FLOW...BUT KIWD WILL SEE SOME DOWNSLOPING
WITH THAT WIND DIRECTION SO HAVE CIGS A LITTLE HIGHER IN MVFR CAT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 423 AM EDT FRI MAR 30 2012
LAKE SUPERIOR WILL BE BETWEEN HIGH PRESSURE IN ONTARIO AND A LOW
PRESSURE SYSTEM MOVING THROUGH NRN ILLINOIS. THIS WILL PRODUCE SE
WINDS UP TO 25KTS TODAY...BEFORE DIMINISHING THIS AFTN/EVENING...AS
A HIGH PRESSURE RIDGE REESTABLISHES ITSELF OVER LAKE SUPERIOR.
THIS SHOULD KEEP WINDS BELOW 25KTS THROUGH THE WEEKEND AS
ANOTHER LOW MOVES THROUGH MANITOBA/ONTARIO ON SATURDAY. LOW
PRESSURE DEVELOPING OVER THE NORTHERN/CENTRAL PLAINS ON SUNDAY WILL
APPROACH THE GREAT LAKES FOR THE BEGINNING OF NEXT WEEK. THIS LOW
WILL WEAKEN AS IT MOVES ACROSS THE GREAT LAKES ON MONDAY AND
TUESDAY AND WINDS SHOULD STAY BELOW 20KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...07
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
733 AM CDT FRI MAR 30 2012
.UPDATE...
12Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
THE RAIN WITH YESTERDAYS SYSTEM SHOULD BE OUT OF OUR EASTERN AREAS
BY THIS MORNING ALTHOUGH THE RADAR LOOP SHOWS A BIT OF A TWIST ON
THE BACK EDGE. IN FACT..THE OVERALL PATTERN OVER THE CONUS AND
INTO CANADA SHOWS MULTIPLE SMALL WAVES. ONE OF THESE IS CROSSING
INTO SOUTH DAKOTA AT THIS TIME AND LOOKS TO PASS MAINLY OVER IOWA
BUT BRUSHING FAR SOUTHERN MINNESOTA. A FEW RETURNS SHOWING UP BUT
RAIN NOT LIKELY AS MOST OF THE DEEPER MOISTURE SWEPT OUT FROM THE SYSTEM
OFF TO THE EAST. AREAS OF STRATUS AND FOG HAS FORMED OVER WESTERN
MINNESOTA IN THE LINGERING HIGHER DEW POINTS. THERE ARE
INDICATIONS THAT THE LOW CLOUDS WILL HANG IN OVER WISCONSIN AND
EASTERN MINNESOTA IN THE EASTERLY FLOW WHICH WILL OF COURSE BE
PROBLEMATIC FOR HIGH TEMPS..ESPECIALLY TODAY AND SATURDAY...BUT
EVEN INTO SUNDAY WITH THE WARM FRONT INTENSIFYING.
WILL HAVE TO WATCH THE DEVELOPING WARM ADVECTION PATTERN FOR
SATURDAY AS THERE IS A HINT OF WEAK WAVE IN THE NORTHWEST FLOW
BEFORE MORE UPPER RIDGING DEVELOPS FOR SUNDAY. HAVE ADDED A SLIGHT
CHANCE OVER WESTERN WI SATURDAY...BUT WOULD NOT BE SURPRISED TO SEE
A NEED FOR PARTS OF EASTERN MN. IT LOOK LIKE MORE OF A HIGH BASED
ACCAS SITUATION BUT COULD SEE ISOLATED SHOWERS.
FOR SUNDAY HAVE NOT CHANGED MAX TEMPS EXCEPT FOR A FEW DEGREES
HIGHER IN SOUTHWEST MN BEHIND THE WARM FRONT. DO NOT SEE MUCH
CHANCE OF PRECIP UNTIL LATER SUNDAY NIGHT WITH THE THICKNESS RIDGE
GENERALLY OVER THE AREA. IT LOOKS LIKE A SPLIT UPPER FLOW
DEVELOPING OVER THE CENTRAL CONUS BUT A RIGHT ENTRANCE REGION OF
THE NORTHERN BRANCH OF THE UPPER JET OVER NORTHWEST MN SHOULD AID
IN SHOWER THUNDERSTORM DEVELOPMENT. THIS COULD BE SOMEWHAT POST
FRONTAL ON MONDAY. IT LOOKS LIKE A DRY PERIOD FOR THE REST OF NEXT
WEEK WITH UPPER RIDGING OVER THE NORTHERN AND CENTRAL PLAINS.
&&
.AVIATION.../12Z TAF ISSUANCE/
RAIN HAS MOVED EAST OF THE TERMINALS THIS MORNING...BUT AN EVER
LOWERING STRATUS DECK...WITH DENSE FOG ACROSS WRN MN HAS REPLACED
IT. NOT EXPECTING ANY IMPROVEMENTS IN CURRENT CONDITIONS UNTIL AT
LEAST 15/16Z...WITH BACK EDGE OF STRATUS SLOWLY WORKING EAST
TODAY. LATEST RUC RUN HAS THE BACK EDGE OF CLOUDS ALONG I-35 AT
21Z. WI TERMINALS WILL LIKELY NEVER LOSE CIGS TODAY...THOUGH THEY
SHOULD WORK THEIR WAY BACK UP TO LOW VFR LEVELS DURING THE
AFTERNOON. FOR TONIGHT...CURRENT THINKING BASED OFF OF SREF PROB
FOR CIGS LESS THAN 3K FT AND BUFKIT SOUNDINGS FROM BOTH THE NAM/GFS
IS THAT LOW STRATUS WILL RETURN. WITH GENERALLY LOW LEVEL RIDGING
WORKING ACROSS THE REGION TODAY...WE WILL LIKELY NOT SEE THE
MOISTURE SCOURED OUT...SO FAVORED THE STRATUS RETURNING TONIGHT
/WITH THE LOWEST CIGS EXPECTED OVER WI/. PRESSURE GRADIENT WILL
REMAIN BAGGY THIS PERIOD...WITH LIGHT E-SE WINDS BEING MAINTAINED.
KMSP...WITH IFR CIGS OVER WI...IS THE THREAT THROUGH 14Z THAT EAST
WINDS MAY BRING SOME OF THESE CIGS INTO THE FIELD...BUT MVFR
CONDITIONS WILL BE MOST PREVALENT. DO NOT EXPECT CIGS TO LIFT
ABOVE 017 UNTIL BETWEEN 16Z AND 18Z. SHOULD SEE SKIES MOSTLY
CLEAR OUT AROUND 00Z...BUT WILL HAVE TO WATCH LOW STRATUS
RETURNING LATE TONIGHT. WAS ON THE FENCE ABOUT BRINGING IT
BACK...BUT WITH SUB 3K FT CIG PROBS OFF THE SREF UP AROUND 80
PERCENT...DECIDED TO BRING THEM BACK AS CLEARING WILL LIKELY NOT
MAKE IT TOO FAR INTO WI. BASED ON NAM/GFS SOUNDINGS...IF THESE
CIGS COME IN...THEY COULD DO SO AS IFR.
//OUTLOOK...SATURDAY THROUGH WEDNESDAY//
SAT-SUN...VFR.
SUN NGT-MON...SHRA/TSRA POSSIBLE WITH FROPA.
MON NGT-WED...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPR/MPG
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
919 AM CDT FRI MAR 30 2012
.UPDATE...
ISSUED AT 910 AM CDT FRI MAR 30 2012
HAVE UPDATED FORECAST THIS MORNING TO BOOST TEMPERATURES A FEW
DEGREES ACROSS THE SOUTHERN PORTION OF THE CWA...AHEAD OF THE
FRONT. 850MB TEMPERATURES WOULD SUGGEST HIGHS IN THE LOWER 80S.
STRIPPED POPS FROM THE FORECAST FOR THIS MORNING AND CONCENTRATED
SCATTERED POPS ALONG AND SOUTH OF I-44 IN MISSOURI AND I-70 IN
ILLINOIS FOR THE AFTERNOON HOURS. LATEST HRRR SUGGESTS CONVECTIVE
INITIATION WILL OCCUR BETWEEN 18 AND 20Z ALONG THE FRONT.
CVKING
&&
.SHORT TERM...
ISSUED AT 325 AM CDT FRI MAR 30 2012
(TODAY)
SURFACE LOW TO CONTINUE TRACKING TO THE EAST THIS MORNING ACROSS
NORTHERN MISSOURI...THEN INTO WESTERN OHIO BY EARLY THIS EVENING.
ASSOCIATED COLD FRONT TO SLIDE THROUGH FORECAST AREA TODAY...MOVING
INTO NORTHEAST MO...WEST CENTRAL IL JUST AFTER DAYBREAK...THEN INTO
THE ST. LOUIS METRO AREA BY MIDDAY. AS FOR CHANCES OF SHOWERS AND
THUNDERSTORMS WITH THIS BOUNDARY...DESPITE CAPES BETWEEN 500 AND
2000 J/KG...CONVERGENCE ALONG BOUNDARY CONTINUES TO LOOK WEAK WITH
BEST LIFT FURTHER TO THE EAST ALONG THE FRONT...CLOSER TO THE
SURFACE LOW. SO BACKED OFF ON POPS A BIT...WITH BEST CHANCES ALONG
AND EAST OF MISSISSIPPI RIVER TODAY. COULD SEE SOME STRONG STORMS BY
THIS AFTERNOON...MAINLY OVER SOUTHERN IL.
AS FOR CLOUDS...SEEING PLENTY OF RESIDUAL MID AND HIGH CLOUDS FROM
ACTIVITY THAT FIRED UP OVERNIGHT...BUT THIS SHOULD THIN A BIT
ALLOWING FOR A MIX OF SUN AND CLOUDS TODAY. SO TEMPS TO WARM UP INTO
THE LOW 70S FAR NORTH TO THE UPPER 70S ALONG AND SOUTH OF I-70.
WINDS TO PICKUP FROM THE SOUTH TO SOUTHWEST THIS MORNING AHEAD OF
FRONT...THEN SWITCH TO THE NORTHWEST WITH THE PASSAGE OF THE COLD
FRONT.
BYRD
&&
.LONG TERM...
ISSUED AT 320 AM CDT FRI MAR 30 2012
(TONIGHT THROUGH THURSDAY)
CDFNT IS EXPECTED TO STALL OVER SRN MO AND FAR SRN IL TONIGHT. A FEW
STRAGGLER SHRA/TSRA MAY EXIST INVOF FRONT EARLY THIS EVENING FOR
SECTIONS OF SERN MO AND SRN IL BUT SHOULD EXIT OR DISSIPATE BY 9PM.
UPPER LEVEL DISTURBANCES...IN THE MEANTIME...WILL CONTINUE TO RIPPLE
THRU THE AREA LATER TONIGHT AND SATURDAY BUT ARE REALLY ONLY
EXPECTED TO HAVE MUCH IF ANY IMPACT NEAR THE FRONTAL ZONE IN THE FAR
SRN FA LATE TONIGHT AND EXPANDING A BIT NWD BY SATURDAY AFTERNOON AS
FRONT BEGINS TO BUCKLE NWD AS A WRMFNT. FOR POPS TONIGHT AND
SATURDAY...A LOT OF CLOSE CALLS BUT NOT A GOOD FEEL FOR ANYTHING
CONSIDERING FRONTAL BOUNDARY SHOULD BE LARGELY IF NOT ENTIRELY OUT
OF THE FA DURING THESE TIMES...SO JUST WENT WITH SLIGHT CHCS.
WRMFNT WILL MAKE ITS BIG PUSH THRU THE FA SATURDAY NIGHT. MUCH OF
THE BETTER LIFT WITH THE LO LEVEL JET SHOULD BE TO THE N OF THE FA
BUT WHAT DOES DEVELOP WILL TRY TO TURN SE TOWARDS THE FA AND HAVE
ACCOUNTED FOR WITH SOME LO-END POPS.
BIG STORY FOR SUNDAY AND MONDAY WILL BE WHAT SHOULD BE THE WARMEST
DAYS OF THIS ABNORMALLY WARM SEASON. SUNDAY WILL FEATURE A
MODERATELY STRONG S-SW FLOW WITH ABUNDANT SUNSHINE. MIXING HEIGHTS
SHOULD REACH H850 AND H850 TEMPS OF 16-18C STRONGLY POINT TOWARDS
MID-UPR 80S FOR MAX TEMPS WITH A REASONABLE CHC OF TOUCHING 90F.
FEEL COMFORTABLE GOING 2-3F ABOVE THE HIGHEST MOS ON THIS DAY.
MONDAY WILL FEATURE A BIT MORE UNCERTAINTY BUT A STRONG ENOUGH
SIGNAL WITH WHAT SHOULD BE A FURTHER DELAY TO THE UPPER LEVEL SYSTEM
TO THE W TO ALSO GO NEAR PERSISTENCE.
SPEAKING OF THE DELAY TO THE UPPER LEVEL SYSTEM ON MONDAY...MODELS
CONTINUE TO SHOVE BACK THE BETTER CHCS FOR RAIN EARLY NEXT WEEK TO
THE MIDDLE PART OF THE WEEK...WITH BOTH ECMWF AND GFS CLOSING A LO
OFF AND AT THIS POINT SHOW A LARGE DEAL OF UNCERTAINTY ON WHERE TO
TRACK IT AND HOW FAST TO DO IT. IT IS WELL WITHIN THE REALM OF
POSSIBILITY THAT NO RAIN WILL RESULT FROM THIS IF THE UPPER LO
TRACKS TOO FAR S OR IS DELAYED TOO MUCH BUT LEANING TOWARDS THE GFS
SOLN SINCE IT WAS THE FIRST TO SHOW THE CUTOFF POTENTIAL AND HAS HAD
BETTER RUN-TO-RUN CONSISTENCY. THE GFS SUGGESTS AN EXTENDED PERIOD
OF RAIN FROM TUESDAY THRU WEDNESDAY AND HAVE CHC CATEGORY POPS FOR
THIS PERIOD. TEMPS APPEAR THEY WILL EDGE CLOSER TO SEASONAL
AVERAGES...ESPECIALLY IF RAIN MATERIALIZES...BUT WITH ANOTHER BIG
RIDGE READY TO BOUNCE BACK FOR LATE WEEK...TEMPS SHOULD HAVE A
FAIRLY EASY TIME STAYING ABOVE AVERAGE.
TES
&&
.AVIATION...
ISSUED AT 652 AM CDT FRI MAR 30 2012
SURFACE LOW HAS MOVED INTO NORTHEASTERN MO AS OF 11Z...NEAR KUIN
AND WILL CONTINUE TO TRACK TO THE EAST WITH ASSOCIATED COLD FRONT
SLOWLY SLIDING TO THE SOUTH ACROSS THE FORECAST AREA. CONFIDENCE
ON TIMING AND COVERAGE OF ANY SHOWERS AND STORMS THAT DO POP UP
ARE HARD TO PIN DOWN...SO KEPT VCSH/CB MENTION FOR SITES ALONG AND
EAST OF MISSISSIPPI RIVER...THROUGH MIDDAY. FEEL THAT KCOU SHOULD
REMAIN DRY. OTHERWISE...SOUTH WINDS TO BECOME SOUTHWEST...THEN
VEER TO THE WEST TO NORTHWEST BEHIND THE FRONTAL BOUNDARY...WITH
VFR CIGS.
SPECIFICS FOR KSTL...COLD FRONT SLOWLY SLIDING TO THE SOUTH
TODAY ACROSS THE FORECAST AREA. CONFIDENCE ON TIMING AND COVERAGE
OF ANY SHOWERS AND STORMS THAT DO POP UP ARE HARD TO PIN DOWN...SO
KEPT VCSH/CB MENTION BETWEEN 15Z AND 20Z. OTHERWISE...SOUTH WINDS
TO BECOME SOUTHWEST...THEN VEER TO THE WEST TO NORTHWEST BEHIND
THE FRONTAL BOUNDARY AROUND 20Z...WITH VFR CIGS THROUGHOUT THE
FORECAST PERIOD.
BYRD
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
607 AM CDT FRI MAR 30 2012
.AVIATION...12Z KGRI TAF. VFR CONDITIONS WILL CONTINUE THROUGH THE
NEXT 24 HOURS. MID TO HIGH LEVEL CLOUDS WILL BE ON THE INCREASE
BUT NOTHING LOWER THAN 10000FT AGL IS CURRENTLY EXPECTED. SURFACE
WINDS WILL BECOME MORE ESTABLISHED FROM THE SOUTHWEST TODAY.
VISIBILITY RESTRICTIONS ARE NOT EXPECTED THROUGH THE NEXT 24
HOURS.
&&
.PREV DISCUSSION... /ISSUED 328 AM CDT FRI MAR 30 2012/
SHORT TERM...TODAY THROUGH SUNDAY NIGHT. A FAIRLY PROGRESSIVE
ZONAL FLOW PATTERN WAS IN PLACE ACROSS THE CENTRAL PLAINS WITH ONE
SHORTWAVE TRANSLATING TO OUR EAST...EAST OF THE MISSOURI
RIVER...WITH ANOTHER UPSTREAM SHORTWAVE TROUGH LOCATED IN EASTERN
WY/CO. CURRENTLY AT THE SURFACE...LOW PRESSURE WAS CENTERED IN
NORTHWEST MISSOURI WITH COOL FRONTAL BOUNDARY STRETCHING THROUGH
CENTRAL KANSAS. SFC DPS REMAIN HIGH ALONG THE MISSOURI RIVER INTO
NORTH CENTRAL AND EASTERN KANSAS WITH READINGS IN THE 50S TO
AROUND 60F AND HRRR SUGGESTS SOME FOG DEVELOPMENT ACROSS NORTHEAST
KANSAS INTO SOUTHEAST NEBRASKA OR JUST ON THE PERIPHERY OF OUR
SOUTHEAST CWA. OBSERVATION AT 08Z AT BELOIT SHOWED VSBY DROPPED TO
ONE QUARTER MILE AND IF TRENDS CONTINUE FOG HEADLINE WILL BE
WARRANTED.
AFOREMENTIONED UPSTREAM SHORTWAVE WILL CROSS OUR CWA AROUND
MIDDAY/EARLY AFTERNOON WITH NEGLIGIBLE EFFECT OTHER THAN INCREASING
CLOUD COVER AND WIND SHIFT TO A MORE WESTERLY DIRECTION AS
ASSOCIATED SURFACE TROUGH SLIDES EAST. CONVECTIVE TEMPS ARE IN THE
MID 70S THIS AFTERNOON AND EXPECT SOME MID LEVEL CU DEVELOPMENT
THIS AFTERNOON WHICH LOOKS TO SLOW TEMP RISE THIS AFTERNOON AND
LOWERED MAX TEMPS BY JUST A DEGREE OR TWO. MODEL FORECAST
SOUNDINGS SUGGEST DEEP MIXING ACROSS OUR WESTERN CWA WITH SFC DPS
DROPPING TO THE 30S THIS AFTN. LOW RELATIVE HUMIDITIES ACROSS OUR
WESTERN CWA...MAINLY DAWSON COUNTY...DROP NEAR 20 PERCENT THIS
AFTERNOON. WIND SPEEDS DO NOT APPEAR EXTREMELY STRONG BUT GUSTS
OVER 20 MPH CANNOT BE RULED OUT AND RIGHT NOW CONDITIONS APPEAR
CLOSE BUT NOT QUITE AT FIRE WEATHER CRITERIA...HOWEVER WILL NEED
TO MONITOR CONDITIONS CLOSELY THIS AFTN IN WESTERN ZONES.
HEADING INTO THE WEEKEND...DRY AND WARM...OR SHALL WE SAY HOT
CONDITIONS FOR LATE MARCH/EARLY APRIL WILL SETTLE INTO OUR REGION.
HEIGHTS RISE TONIGHT BEHIND DEPARTING SHORTWAVE TROUGH...WITH UPPER
RIDGING BUILDING ACROSS THE CENTRAL PLAINS ON SATURDAY AHEAD OF AN
UPPER TROUGH DEEPENING ALONG THE WEST COAST. THE RIDGE REMAINS IN
PLACE ACROSS THE CENTRAL PLAINS EARLY SUNDAY BEFORE FLOW
TRANSITIONS SOUTHWESTERLY BY AFTERNOON AS UPPER TROUGH MOVES INTO
THE ROCKIES. H85 TEMPS ARE RIGHT AROUND 20C BOTH SATURDAY AND
SUNDAY AND FORECAST SOUNDINGS SUGGEST MIXING WILL BE EVEN HIGHER
THAN H85. HAVE MAINTAINED UPPER 80S FOR HIGHS ON SATURDAY WITH A
DRIER AIRMASS IN PLACE AND WARMING AIDED BY DOWNSLOPE WIND
COMPONENT. BY SUNDAY LLVL FLOW TRANSITIONS SOUTHERLY WITH SFC
CYCLOGENESIS ALONG THE HIGH PLAINS AND MOISTURE RETURNS NORTH WITH
DPS RETURNING TO THE 50S. CURRENTLY HAVE HIGHS FORECAST IN THE
MID/UPPER 80S FOR SUNDAY. RECORD HIGHS BOTH SATURDAY AND SUNDAY
ARE IN THE 88 TO 90 RANGE FOR GRAND ISLAND...HASTINGS AND
KEARNEY...AND WE WILL BE RIGHT NEAR THERE.
SATURDAY WILL BE A DAY TO MONITOR FOR FIRE WEATHER CONCERNS AS WELL
AS A LARGER PORTION OF OUR CWA WILL SEE LOW RELATIVE HUMIDITIES
BELOW 20 PERCENT...BUT THAT BEING SAID...WINDS ARE NOT LOOKING
OVERLY STRONG AT THIS POINT.
UPPER TROUGH CONTINUES TO DEEPEN IN THE SOUTHERN ROCKIES SUNDAY
NIGHT AND FRONTAL PROGRESSION HAS SLOWED. WITH SLOWER FROPA...HAVE
RAISED LOW TEMPS QUITE A BIT AS DPS LOOK TO HOLD IN THE 50S FOR THE
MOST PART THROUGH THE NIGHT. WITH FRONT MAINLY TO OUR WEST OR ON
THE PERIPHERY OF OUR WESTERN COUNTIES...HAVE REMOVED POPS FOR THIS
TIME FRAME.
LONG TERM...STARTING 12Z MONDAY. GUIDANCE SUGGESTS A MID LEVEL LOW
WILL PUSH ACROSS THE SOUTHERN PLAINS DURING THE DAY MONDAY...WITH
A MID LEVEL SHORT WAVE ALSO PUSHING ACROSS THE CENTRAL AND
NORTHERN PLAINS ON MONDAY. AN ASSOCIATED LOW LEVEL BAROCLINIC ZONE
IS ALSO EXPECTED TO CLEAR OUR CWA EARLY MONDAY. ALTHOUGH THERE IS
STILL CONSIDERABLE UNCERTAINTY AS TO WHEN THE SURFACE FRONT WILL
ACTUALLY CLEAR THE AREA...INCREASED VALUES OF LOW LEVEL MOISTURE
AHEAD OF THE FRONT WILL STILL PROMOTE ENOUGH INSTABILITY FOR
CONVECTIVE DEVELOPMENT AND WITH QPF FIELDS FROM THE OPERATIONAL
GFS STILL SUGGESTING PRECIPITATION WILL BE REALIZED ACROSS OUR
EAST ON MONDAY...WILL GO AHEAD AND CONTINUE CARRYING SLIGHT
CHANCES POPS ACROSS OUR EAST FOR MONDAY. THE MID LEVEL LOW OVER
THE SOUTHERN PLAINS IS THEN EXPECTED TO LIFT TO THE NORTHEAST
MONDAY NIGHT...WITH PERHAPS ENOUGH MID LEVEL THERMAL ADVECTION TO
THE EAST AND NORTHEAST OF THE LOW FOR PRECIPITATION PRODUCTION
ACROSS PORTIONS OF OUR CWA MONDAY NIGHT INTO TUESDAY AND AS A
RESULT...WENT AHEAD AND CONTINUED SLIGHT CHANCE POPS ACROSS MUCH
OF THE CWA MONDAY NIGHT INTO TUESDAY. AN OVERALL LACK IN KINEMATIC
FORCING DUE TO STRENGTHENING UPPER LEVEL RIDGING ACROSS THE
CENTRAL CONUS SHOULD KEEP US DRY TUESDAY NIGHT THROUGH THURSDAY.
RELATIVELY COOLER WEATHER WILL BE OBSERVED DURING MUCH OF THE
EXTENDED FORECAST PERIOD AS A COOLER AIRMASS INFILTRATES OUR AREA
POST-FROPA ON MONDAY. THAT BEING SAID...TEMPERATURES ARE STILL
EXPECTED TO REMAIN AT ABOVE-NORMAL LEVELS WITH HIGHS GENERALLY IN
THE 60S AND 70S...AND LOWS GENERALLY IN THE 30S AND 40S.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
AVIATION/LONG TERM...BRYANT
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1100 AM CDT FRI MAR 30 2012
.DISCUSSION...
CHALLENGE THIS MORNING IS FOG...CLOUD TRENDS AND TEMPERATURES. DENSE
FOG WITH VISIBILITY LESS THAN ONE QUARTER MILE HAS LIFTED ACROSS
MUCH OF EASTERN ND...EXCEPT ACROSS THE FAR WESTERN FORECAST AREA
FROM ROLLA TO DEVILS LAKE TO JAMESTOWN. AS PRESSURE GRADIENT
STRENGTHENS...EXPECT SOUTHERLY SURFACE WINDS TO INCREASE AND SCOUR
OUT REMAINING AREAS OF FOG. WILL ALLOW THE DENSE FOG ADVISORY TO
EXPIRE AT 11 AM CDT AND COVER ANY LINGERING FOGGY AREAS WITH
NOWCASTS.
LOW STRATUS DECK ACROSS ALL AREAS EXCEPT SOUTHEAST ND WILL BE VERY
SLOW TO DISSIPATE GIVEN WEAK FLOW ALOFT. RUC 925 HPA RH SEEMS TO
HAVE A GOOD HANDLE ON CURRENT CONDITIONS AND SUGGESTS SOME CLEARING
ALONG AND WEST OF THE VALLEY THIS AFTERNOON...BUT PERSISTENT
OVERCAST CONDITIONS ACROSS NORTHWEST MN THROUGH AT LEAST 00 UTC
TONIGHT. AS A RESULT...SIGNIFICANTLY INCREASED SKY COVER THROUGH THE
DAY AND DROPPED TEMPERATURES 2-5 DEGREES. IF CLOUDS HANG TOUGH...
STILL MAY BE TOO WARM WITH SOME AREAS EAST OF THE VALLEY NOT
BREAKING THE 40 DEGREE MARK. WILL MAKE ADDITIONAL ADJUSTMENTS THIS
AFTERNOON IF NEEDED.
&&
.AVIATION...
WHEREAS VISIBILITY WILL IMPROVE LATE THIS MORNING AND EARLY
AFTERNOON AS FOG LIFTS AND DISSIPATES...IFR/MVFR STRATUS DECK WILL
BE SLOW TO ERODE THROUGH THE DAY. DIFFICULT TO SAY EXACTLY WHEN
CEILINGS WILL IMPROVE...SO WILL UPDATE TAFS AS NECESSARY. LIGHT
AND VARIABLE WIND THIS MORNING WILL INCREASE AND SHIFT TO THE
SOUTH THIS AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 430 AM CDT FRI MAR 30 2012/
SHORT TERM...TODAY THROUGH SUNDAY NIGHT.
UPPER LEVEL FLOW WAS ZONAL AND IS FORECAST TO BECOME A LITTLE MORE
AMPLIFIED AFTER 48 HOURS. UPPER TROUGH OVER THE EASTERN PACIFIC
WILL MOVE INTO THE WESTERN US SAT NIGHT AND WILL BEGIN TO AFFECT THE
FORECAST AREA SUN NIGHT. UPPER LEVEL JET WILL BE NORTH OF THE
FORECAST AREA SAT AND SUN.
WATER VAPOR LOOP SHOWED A SHORT WAVE OVER SOUTHERN ALTA/BC THAT WILL
MOVE ACROSS SOUTHERN MAN TONIGHT. MAY PRODUCE LIGHT SHOWERS OVER THE
FAR NORTH AND NORTHEAST SAT MORNING.
EAST WEST CROSS SECTION INDICATED DRY AIR WAS MOVING IN ALOFT WHILE
THE BOUNDARY LAYER REMAINED MOIST. SURFACE OBS AND FOG LOOP
INDICATED FOG WAS SPREADING SOUTH AND WEST OVER EASTERN ND WHILE A
CLOUD DECK REMAINED STATIONARY OVER NORTHWEST AND WEST CENTRAL MN.
WILL KEEP FOG ADVISORY GOING OVER EASTERN ND AS CLOUD DECK OVER MN
DOES NOT APPEAR TO BE MOVING.
LONG TERM [MONDAY-THURSDAY]...
GFS AND GEM START OUT IN GOOD AGREEMENT ON MONDAY...WITH A SPLIT
SYSTEM MOVING INTO THE PLAINS AND THE NORTHERN BRANCH SHORTWAVE INTO
THE DAKOTAS. 12Z ECMWF WAS MORE PHASED WITH THE TROUGH...BUT THE
00Z RUN IS MORE IN LINE WITH THE OTHER DETERMINISTIC MODELS. ALL
HAVE A TROUGH OF LOW PRESSURE MAINLY OVER THE EASTERN CWA WITH
PRECIP. SHOWALTERS ARE NEGATIVE...SO WILL KEEP A THUNDER MENTION
FOR THE EASTERN TIER MONDAY MORNING BEFORE MORE STABLE AIR MOVES IN
WITH A COLD FRONT. PRECIP SHOULD BE MOSTLY RAIN ALTHOUGH WITH 850MB
TEMPS DROPPING BELOW ZERO AS THE SYSTEM EXITS MONDAY NIGHT SOME SNOW
MIXING IN OVER LAKE OF THE WOODS IS NOT OUT OF THE QUESTION. BY
TUESDAY AND THROUGH THE REST OF THE WORK WEEK...ALL OF THE MEDIUM
RANGE MODELS ARE IN PRETTY GOOD AGREEMENT FOR WARMER AND DRIER
CONDITIONS AS UPPER RIDGING AMPLIFIES OVER THE NORTHERN PLAINS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
ROGERS/HOPPES
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1045 AM CDT FRI MAR 30 2012
.DISCUSSION.../ISSUED AT 1045 AM CDT/
A BAND OF MID CLOUDS OVERSPREADING MUCH OF THE AREA HAS ALLOWED FOG
TO PERSIST GENERALLY EAST OF THE INTERSTATE 29 CORRIDOR THROUGH THE
MORNING...SO EARLIER EXTENDED DENSE FOG ADVISORY THROUGH 17Z.
OTHERWISE...RADAR PICKING UP A BROAD AREA OF ECHOES THROUGH THE
JAMES RIVER VALLEY WITH MID LEVEL WAVE PUSHING OUT OF CENTRAL SOUTH
DAKOTA. OBS HAVE NOT REPORTED ANY RAIN WITH THIS ACTIVITY...AND
CEILINGS ARE RUNNING AROUND 9 TO 10 KFT...SO NOT MUCH REACHING THE
GROUND AT THIS POINT...SO JUST EXPANDED THE MENTION OF SPRINKLES
EASTWARD TO I 29 INTO THE AFTERNOON. ALSO LOWERED HIGH TEMPERATURES
IN PORTIONS OF OUR NORTH AND EAST WHERE THINK CLOUDS WILL REMAIN THE
LONGEST. UPDATES OUT.
&&
.PREV DISCUSSION.../ISSUED AT 347 AM CDT/
AREAS OF FOG HAVE DEVELOPED OVERNIGHT EAST OF THE JAMES RIVER
VALLEY. AM WATCHING AREAS UP NORTH OF 90 AND EAST OF I-29 WHERE
VISIBILITIES HAVE CONSISTENTLY BEEN THE LOWEST DUE TO INCREASED
AMOUNTS OF LOW LEVEL MOISTURE FROM THE RAIN THURSDAY EVENING. FOG
APPEARS TO BE RELATIVELY SHALLOW RIGHT NOW...BUT RUC MODEL SOUNDINGS
SUGGESTS OVER THE NEXT FEW HOURS FOG WILL THICKEN. RAIN TOTALS WERE
FAIRLY LIGHT ESPECIALLY SOUTH OF I-90 SO THERE IS SOME QUESTION AS
TO HOW THICK THE FOG WILL GET DOW THERE. IF DENSE FOG BECOMES MORE
WIDESPREAD OVER THE PRE-DAWN HOURS...WILL ISSUE DENSE FOG ADVISORY.
OTHERWISE...EXPECTING FOG TO GRADUALLY BURN OFF TODAY LEADING TO A
PLEASANT DAY ACROSS THE AREA. SOUTHEAST WINDS WILL GRADUALLY
INCREASE FROM WEST TO EAST TODAY...BUT WILL STILL NOT BE ALL THAT
STRONG. TEMPERATURES WILL STILL BE 20-25 DEGREES ABOVE NORMAL.
GREATEST MIXING IS IN THE WEST TODAY...AND SOME CONCERN ACROSS
SOUTHWEST MINNESOTA THAT LOW LEVEL MOISTURE MAY NOT MIX OUT TODAY.
AS SUCH...ADDED MENTION OF PATCHY FOG THERE BUT MAY NEED TO BEEF UP
WORDING IN FUTURE UPDATES.
WARMING TREND EXPECTED OVER THE WEEKEND. APPEARS AS THOUGH FAIRLY
DENSE CIRRUS SHIELD WILL HINDER WARMING POTENTIAL ON
SATURDAY...HOWEVER...SUNDAY LOOKS TO BE DOWNRIGHT HOT WITH STRONG
UPPER LEVEL RIDGE BUILDING INTO THE AREA. HAVE INCREASED FORECAST
HIGHS SLIGHTLY...ESPECIALLY ACROSS WESTERN CWA WITH SLOWER
PROGRESSION OF THE FRONT. CURRENT FORECAST HIGHS ARE AROUND 3
DEGREES ABOVE RECORD IN MOST LOCATIONS.
NOT A LOT OF MOISTURE OR UPPER LEVEL DYNAMICS WITH FRONT ON SUNDAY
NIGHT. AS SUCH...CONTINUED TO DECREASE POP MENTION SUNDAY NIGHT
INTO MONDAY MORNING.
ALTHOUGH WINDS WILL BE STRONG OUT OF THE NORTHWEST AND TEMPERATURES
WILL BE MUCH COOLER THAN THE PREVIOUS DAY...TEMPERATURES STILL
APPEAR TO BE WELL ABOVE NORMAL ON MONDAY. APPEARS AS THOUGH THERE
WILL BE A GENERAL WARMING TREND NEXT WEEK...WITH THE POTENTIAL FOR
80S RETURNING BY WEEKS END.
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
HAD TO MAKE A FEW QUICK CHANGES. WIDESPREAD MVFR TO IFR CEILINGS CAN
BE EXPECTED ALONG AND EAST IF I29 THROUGH 14Z FRIDAY ALONG WITH
VISIBILITIES BELOW 1 MILE AT TIMES ON FOG. SHOWERS MAY LINGER
THROUGH 08Z EXTREME EASTERN PART OF AREA WELL EAST OF TAF SITES.
OTHERWISE GENERALLY VFR CONDITIONS SHOULD RULE THROUGH 31/06Z. LOCAL
EXCEPTIONS SEEM POSSIBLE IN THE FORM OF 3-5SM IN LIGHT FOG 08Z-13Z.
AM MENTIONING THIS REDUCTION IN HON AND FSD TAFS BUT NOT IN SUX TAF
DUE TO LONGER LINGERING NORTHERLY SURFACE FLOW ALTHOUGH THIS S AREA
AND EAST WILL HAVE THE WEAKEST DRYING. NO OTHER POSSIBLE EXCEPTION
SEEN WITH DRY REGIME DEVELOPING. A FEW CEILINGS AROUND 10K FEET
12Z-31/00Z IS PROBABLY THE WORST CONDITION FORESEEN OTHER THAN THE
ABOVE MENTIONED LIGHT FOG. / WILLIAMS
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ071-072-
080-097.
NE...NONE.
SD...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR SDZ039-040-
054>056.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1044 AM CDT FRI MAR 30 2012
.DISCUSSION...ADJUSTED TEMPERATURES (ESPECIALLY HOURLY) BASED ON
OBSERVATIONS AND TRENDS...BUT OVERALL DID LOWER SOME VALUES A
DEGREE OR SO. ATMOSPHERE IS TRYING TO RE-LOAD AFTER LAST NIGHTS
ACTIVITY BUT STILL PRETTY CAPPED. STILL A CHANCE FOR AFTERNOON
CONVECTION MAINLY INLAND IF HEATING ALONG WITH SOME SURFACE
BOUNDARIES/CONVERGENT AREAS DEVELOP AS AIRMASS REMAINS PRETTY
UNSTABLE. WATER VAPOR IMAGERY SHOWING ANOTHER VERY WEAK IMPULSE
GOING INTO NORTHERN MEXICO WHICH SHOULD IMPACT WESTERN AREAS LATE
THIS AFTERNOON OR EARLY TONIGHT. ERGO...KEPT POPS IN FOR TONIGHT
AS-IS...BUT DID ADJUST SOME INLAND POPS DOWN FROM WHAT WAS
PREVIOUSLY FORECAST GIVEN THE SLIGHTLY DRIER AIRMASS TODAY AND
MORE STABLE BEGINNINGS TO SOUTH TEXAS WEATHER THIS MORNING.
UPDATED PRODUCTS OUT.
&&
.MARINE...CONVECTION OFFSHORE HAS RESULTED IN LIGHT AND VARIABLE
WINDS THIS MORNING. SHOULD RETURN TO ONSHORE FLOW THIS AFTERNOON
AS SEA BREEZE GETS GOING. KEPT SOME CONVECTION IN FOR LATER THIS
AFTERNOON BUT LIKELY ACTIVITY WILL REMAIN INLAND. NO CHANGES TO
LATTER PERIODS YET.
&&
.PREV DISCUSSION... /ISSUED 709 AM CDT FRI MAR 30 2012/
DISCUSSION...SEE AVIATION SECTION FOR 12Z TAF DISCUSSION.
AVIATION...CONDITIONS AT KVCT WILL REMAIN AT LIFR THROUGH 15Z BEFORE
GRADUALLY IMPROVING DURING THE MID TO LATE MORNING. OTHERWISE...VFR
CONDITIONS WILL PREVAIL AT OTHER TAF SITES ACROSS SOUTH TX WITH A
MID AND HIGH LEVEL DECK OF CLOUDS. A REPEAT OF LATE AFTERNOON
SHRA/TSRA ACROSS THE REGION IS POSSIBLE...BUT NOT EXPLICITLY
MENTIONED IN TAFS DUE TO TIMING CONCERNS. A VERY UNSTABLE AIRMASS
WILL BE IN PLACE TODAY WHERE AFTERNOON SCATTERED CONVECTION
DEVELOPMENT CAN BE INITIATED ON THE SEA BREEZE BOUNDARY...PARTICULARLY
ACROSS THE EASTERN COASTAL PLAINS AND BRUSH COUNTRY AFFECTING
SITES SUCH AS KCOT AND KALI BETWEEN 19-23Z. MVFR CEILINGS ARE EXPECTED
TO MOVE BACK INTO THE COASTAL PLAINS BY 03Z SATURDAY. LOOKING OUT
WEST...A COMPLEX OF THUNDERSTORMS ACROSS MEX ARE EXPECTED TO
AFFECT LRD LATER THIS EVENING TOWARD MIDNIGHT. THIS SYSTEM IS
EXPECTED TO GENERALLY MOVE SE ACROSS PORTIONS OF WEBB AND DUVAL
COUNTIES.
PREV DISCUSSION... /ISSUED 446 AM CDT FRI MAR 30 2012/
SHORT TERM (TODAY THROUGH SATURDAY)...REMNANT MCV IS APPARENT ON
SATELLITE IMAGERY OVER THE WESTERN GULF IN ASSOCIATION WITH
DECAYING CONVECTION THAT LIFTED FROM THE RGV AND TAMAULIPAS INTO
THE OFFSHORE WATERS. WEAK SUBSIDENCE WILL TAKE PLACE THIS MORNING
IN THE WAKE OF THE MCV. ATMOSPHERE WILL BECOME INCREASINGLY
UNSTABLE AS THE MORNING PROGRESSES INTO AFTERNOON. MODELS SHOW
THIS VERY UNSTABLE AIRMASS TO REMAIN OVER THE REGION TODAY.
FORECAST INSTABILITY FIELDS SHOW CAPE FROM 3500-4000 J/KG OVER THE
INLAND COASTAL PLAINS AND BRUSH COUNTRY THIS AFTERNOON WITH LIFTED
INDEX VALUES AROUND -10 TO -12 DEGREES WITH LIMITED CONVECTIVE
INHIBITION. RAISED POPS TO HIGH END CHANCES OF THUNDERSTORMS
BETWEEN THE PARALLELING HIGHWAY 16 AND HIGHWAY 281 CORRIDOR THIS
AFTERNOON. POTENTIAL FOR ISOLATED STRONG TO SEVERE THUNDERSTORMS
POSSIBLE AGAIN THIS AFTERNOON INTO THE EARLY EVENING AS SEABREEZE
PUSHES WESTWARD. TURNING THE FOCUS OUT WEST TONIGHT...GFS MODEL
INDICATES A STRONG VORT LOBE FORECAST TO MOVE TOWARD THE NUEVO
LEON/COAHUILA/TAMAULIPAS MEXICAN TRI- STATE REGION FRI NIGHT WITH
GOOD PVA...INSTABILITY...AND MOISTURE TO EXIST FOR MCS FEATURE
POSSIBLY DEVELOPING ALONG RIO GRANDE WITH CORFIDI VECTORS
SUGGESTING A TRACK TO THE SOUTHWEST THROUGH THE NIGHT.
HOWEVER...ECMWF...TEXAS TECH WRF AND HRRR NOT AS ROBUST WITH THIS
MCS POTENTIAL. PAINTED 30 TO 50 PERCENT CHANCES OF SHOWERS AND
THUNDERSTORMS MAINLY WEST OF HIGHWAY 281 DURING THE NOCTURNAL
HOURS WHILE STRATIFYING POPS TO THE LOWER SIDE TOWARD THE COAST.
QUIETER WEATHER...WITH MAINLY ISOLATED TO WIDELY SCATTERED
CONVECTION ANTICIPATED SATURDAY IN THE WAKE OF A MID LEVEL SHORT-
WAVE TROF WITH PWATS TRENDING SLIGHTLY LOWER WITH DRIER AIR
STARTING TO WORK INTO THE REGION WITH CAPES STILL REMAINING ABOVE
2500 J/KG. ABOVE NORMAL TEMPERATURES THROUGH THE SHORT TERM PERIOD
WITH BREEZY LATE MORNING AND AFTERNOON WINDS.
LONG TERM (SATURDAY NIGHT THROUGH WEDNESDAY NIGHT)...DESPITE
WEAKNESS IN FLOW ALOFT STILL EXISTING SATURDAY NIGHT...MODELS
SUGGEST MOISTURE MAY NOT BE AS IMPRESSIVE AS THE LAST FEW DAYS.
PWATS VALUES MAY DROP BELOW 1 INCH BY 12Z SUNDAY SO HAVE OPTED TO
LEAVE THUNDERSTORM CHANCES OUT OF THE FORECAST AT THIS TIME. ANOTHER
WARM DAY CAN EXPECTED ON SUNDAY ACROSS SOUTH TEXAS WITH LOWER/MID
90S IN THE BRUSH COUNTRY TO LOWER 80S ALONG THE COAST. GUIDANCE HAS
BEEN TOO WARM OUT WEST LATELY...AND WITH RECENT RAINS OVER THOSE
LOCATIONS TOOK A FEW DEGREES OFF MOS TEMPS. FOR EARLY NEXT WEEK...
TIMING OF COLD FRONT WILL REMAIN THE MAIN FORECAST CHALLENGE. MODELS
NOW OFFERING UP A CLOSED LOW SOLUTION OVER THE CENTRAL PLAINS STATES
MONDAY AND TUESDAY. COLD FRONT TIMING HAS BEEN SLOWED DOWN WITH THE
00Z RUNS AND HAVE INCORPORATED THIS INTO THE FORECAST...WITH THE GFS
BEING QUICKER THAN THE EURO WITH FROPA OFF THE COAST. FORECAST
CONFIDENCE IS NOT THE HIGHEST IN TIMING OF THE FRONT AND SUSPECT
FURTHER FINE TUNING WILL BE NEEDED. FOR NOW WILL PLACE THE FRONT
ROUGHLY THROUGH THE WESTERN HALF OF THE REGION BY 12Z TUESDAY AND
OFF THE COAST BY 18Z. ANOTHER DAY OF WARM TEMPS IN ADVANCE OF THE
FRONT WILL OCCUR ON MONDAY. INCLUDED SOME LOW END THUNDERSTORM
CHANCES MONDAY AND MONDAY NIGHT AS LIFT/INSTABILITY INCREASES AHEAD
OF UPPER TROUGH/FRONT. TEMPS WILL BE KNOCKED DOWN BY 5 TO 10 DEGREES
FOR TUESDAY AND WEDNESDAY...WITH LOWER 80S OUT WEST TO UPPER 70S
ALONG THE COAST. AS FOR THE LATTER HALF OF THE WEEK...THERE WILL BE
A SLOW RETURN IN MOISTURE AS NORTHEAST-EASTERLY FLOW AT THE SURFACE
BECOMES SOUTHEAST LATE THURSDAY. RIDGING ALOFT WILL LEAD TO PARTLY
CLOUDY SKIES IN THE AFTERNOON...QUIET WEATHER AND A GRADUAL WARMING
TREND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 87 68 86 68 87 / 30 30 20 10 10
VICTORIA 83 67 84 68 85 / 30 20 20 10 10
LAREDO 91 69 93 68 94 / 20 50 20 10 10
ALICE 89 66 89 68 89 / 30 40 30 10 10
ROCKPORT 81 69 80 70 80 / 30 20 20 10 10
COTULLA 87 65 90 67 92 / 30 50 20 10 10
KINGSVILLE 88 68 88 67 88 / 30 30 20 10 10
NAVY CORPUS 82 68 82 69 82 / 30 20 20 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
GW/86...SHORT TERM
RH/79...LONG TERM
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
709 AM CDT FRI MAR 30 2012
.DISCUSSION...SEE AVIATION SECTION FOR 12Z TAF DISCUSSION.
&&
.AVIATION...CONDITIONS AT KVCT WILL REMAIN AT LIFR THROUGH 15Z BEFORE
GRADUALLY IMPROVING DURING THE MID TO LATE MORNING. OTHERWISE...VFR
CONDITIONS WILL PREVAIL AT OTHER TAF SITES ACROSS SOUTH TX WITH A
MID AND HIGH LEVEL DECK OF CLOUDS. A REPEAT OF LATE AFTERNOON
SHRA/TSRA ACROSS THE REGION IS POSSIBLE...BUT NOT EXPLICITLY
MENTIONED IN TAFS DUE TO TIMING CONCERNS. A VERY UNSTABLE AIRMASS
WILL BE IN PLACE TODAY WHERE AFTERNOON SCATTERED CONVECTION
DEVELOPMENT CAN BE INITIATED ON THE SEA BREEZE BOUNDARY...PARTICULARLY
ACROSS THE EASTERN COASTAL PLAINS AND BRUSH COUNTRY AFFECTING
SITES SUCH AS KCOT AND KALI BETWEEN 19-23Z. MVFR CEILINGS ARE EXPECTED
TO MOVE BACK INTO THE COASTAL PLAINS BY 03Z SATURDAY. LOOKING OUT
WEST...A COMPLEX OF THUNDERSTORMS ACROSS MEX ARE EXPECTED TO
AFFECT LRD LATER THIS EVENING TOWARD MIDNIGHT. THIS SYSTEM IS
EXPECTED TO GENERALLY MOVE SE ACROSS PORTIONS OF WEBB AND DUVAL
COUNTIES.
&&
.PREV DISCUSSION... /ISSUED 446 AM CDT FRI MAR 30 2012/
SHORT TERM (TODAY THROUGH SATURDAY)...REMNANT MCV IS APPARENT ON
SATELLITE IMAGERY OVER THE WESTERN GULF IN ASSOCIATION WITH
DECAYING CONVECTION THAT LIFTED FROM THE RGV AND TAMAULIPAS INTO
THE OFFSHORE WATERS. WEAK SUBSIDENCE WILL TAKE PLACE THIS MORNING
IN THE WAKE OF THE MCV. ATMOSPHERE WILL BECOME INCREASINGLY
UNSTABLE AS THE MORNING PROGRESSES INTO AFTERNOON. MODELS SHOW
THIS VERY UNSTABLE AIRMASS TO REMAIN OVER THE REGION TODAY.
FORECAST INSTABILITY FIELDS SHOW CAPE FROM 3500-4000 J/KG OVER THE
INLAND COASTAL PLAINS AND BRUSH COUNTRY THIS AFTERNOON WITH LIFTED
INDEX VALUES AROUND -10 TO -12 DEGREES WITH LIMITED CONVECTIVE
INHIBITION. RAISED POPS TO HIGH END CHANCES OF THUNDERSTORMS
BETWEEN THE PARALLELING HIGHWAY 16 AND HIGHWAY 281 CORRIDOR THIS
AFTERNOON. POTENTIAL FOR ISOLATED STRONG TO SEVERE THUNDERSTORMS
POSSIBLE AGAIN THIS AFTERNOON INTO THE EARLY EVENING AS SEABREEZE
PUSHES WESTWARD. TURNING THE FOCUS OUT WEST TONIGHT...GFS MODEL
INDICATES A STRONG VORT LOBE FORECAST TO MOVE TOWARD THE NUEVO
LEON/COAHUILA/TAMAULIPAS MEXICAN TRI- STATE REGION FRI NIGHT WITH
GOOD PVA...INSTABILITY...AND MOISTURE TO EXIST FOR MCS FEATURE
POSSIBLY DEVELOPING ALONG RIO GRANDE WITH CORFIDI VECTORS
SUGGESTING A TRACK TO THE SOUTHWEST THROUGH THE NIGHT.
HOWEVER...ECMWF...TEXAS TECH WRF AND HRRR NOT AS ROBUST WITH THIS
MCS POTENTIAL. PAINTED 30 TO 50 PERCENT CHANCES OF SHOWERS AND
THUNDERSTORMS MAINLY WEST OF HIGHWAY 281 DURING THE NOCTURNAL
HOURS WHILE STRATIFYING POPS TO THE LOWER SIDE TOWARD THE COAST.
QUIETER WEATHER...WITH MAINLY ISOLATED TO WIDELY SCATTERED
CONVECTION ANTICIPATED SATURDAY IN THE WAKE OF A MID LEVEL SHORT-
WAVE TROF WITH PWATS TRENDING SLIGHTLY LOWER WITH DRIER AIR
STARTING TO WORK INTO THE REGION WITH CAPES STILL REMAINING ABOVE
2500 J/KG. ABOVE NORMAL TEMPERATURES THROUGH THE SHORT TERM PERIOD
WITH BREEZY LATE MORNING AND AFTERNOON WINDS.
LONG TERM (SATURDAY NIGHT THROUGH WEDNESDAY NIGHT)...DESPITE
WEAKNESS IN FLOW ALOFT STILL EXISTING SATURDAY NIGHT...MODELS
SUGGEST MOISTURE MAY NOT BE AS IMPRESSIVE AS THE LAST FEW DAYS.
PWATS VALUES MAY DROP BELOW 1 INCH BY 12Z SUNDAY SO HAVE OPTED TO
LEAVE THUNDERSTORM CHANCES OUT OF THE FORECAST AT THIS TIME. ANOTHER
WARM DAY CAN EXPECTED ON SUNDAY ACROSS SOUTH TEXAS WITH LOWER/MID
90S IN THE BRUSH COUNTRY TO LOWER 80S ALONG THE COAST. GUIDANCE HAS
BEEN TOO WARM OUT WEST LATELY...AND WITH RECENT RAINS OVER THOSE
LOCATIONS TOOK A FEW DEGREES OFF MOS TEMPS. FOR EARLY NEXT WEEK...
TIMING OF COLD FRONT WILL REMAIN THE MAIN FORECAST CHALLENGE. MODELS
NOW OFFERING UP A CLOSED LOW SOLUTION OVER THE CENTRAL PLAINS STATES
MONDAY AND TUESDAY. COLD FRONT TIMING HAS BEEN SLOWED DOWN WITH THE
00Z RUNS AND HAVE INCORPORATED THIS INTO THE FORECAST...WITH THE GFS
BEING QUICKER THAN THE EURO WITH FROPA OFF THE COAST. FORECAST
CONFIDENCE IS NOT THE HIGHEST IN TIMING OF THE FRONT AND SUSPECT
FURTHER FINE TUNING WILL BE NEEDED. FOR NOW WILL PLACE THE FRONT
ROUGHLY THROUGH THE WESTERN HALF OF THE REGION BY 12Z TUESDAY AND
OFF THE COAST BY 18Z. ANOTHER DAY OF WARM TEMPS IN ADVANCE OF THE
FRONT WILL OCCUR ON MONDAY. INCLUDED SOME LOW END THUNDERSTORM
CHANCES MONDAY AND MONDAY NIGHT AS LIFT/INSTABILITY INCREASES AHEAD
OF UPPER TROUGH/FRONT. TEMPS WILL BE KNOCKED DOWN BY 5 TO 10 DEGREES
FOR TUESDAY AND WEDNESDAY...WITH LOWER 80S OUT WEST TO UPPER 70S
ALONG THE COAST. AS FOR THE LATTER HALF OF THE WEEK...THERE WILL BE
A SLOW RETURN IN MOISTURE AS NORTHEAST-EASTERLY FLOW AT THE SURFACE
BECOMES SOUTHEAST LATE THURSDAY. RIDGING ALOFT WILL LEAD TO PARTLY
CLOUDY SKIES IN THE AFTERNOON...QUIET WEATHER AND A GRADUAL WARMING
TREND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 86 68 86 68 87 / 30 30 20 10 10
VICTORIA 84 67 84 68 85 / 30 20 20 10 10
LAREDO 92 69 93 68 94 / 20 50 20 10 10
ALICE 89 66 89 68 89 / 50 40 30 10 10
ROCKPORT 82 69 80 70 80 / 30 20 20 10 10
COTULLA 87 65 90 67 92 / 30 50 20 10 10
KINGSVILLE 87 68 88 67 88 / 30 30 20 10 10
NAVY CORPUS 81 68 82 69 82 / 30 20 20 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
SC/70...SHORT TERM
TB/78...LONG TERM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
615 AM CDT FRI MAR 30 2012
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
329 AM CDT FRI MAR 30 2012
MAIN FORECAST CONCERNS ARE ON CLOUDS THROUGH SATURDAY MORNING AS
WELL AS TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED TROUGHING OVER THE NORTHEAST PACIFIC INTO SOUTHWEST
CANADA...WEAK RIDGING OVER ONTARIO...THEN TROUGHING IN SOUTHEAST
CANADA. SOUTH OF THE WEAK RIDGING...THERE WERE A FEW SHORTWAVES
MOVING THROUGH A NEARLY ZONAL FLOW. THE FIRST AND MOST SIGNIFICANT
ONE STRETCHED FROM NORTHEAST MINNESOTA INTO WESTERN IOWA. DPVA FROM
THIS SHORTWAVE COMBINED WITH NUMEROUS OTHER FAVORABLE PRECIPITATION
MECHANISMS WERE HELPING TO PRODUCE SHOWERS OVER MUCH OF THE FORECAST
AREA. SOME OF THE MECHANISMS INCLUDE: RIGHT ENTRANCE REGION SUPPORT
OF A 90-100 KT JET AT 200-225MB OVER NORTHERN WISCONSIN AND UPPER
MICHIGAN PER RUC ANALYSIS...ISENTROPIC LIFT/WARM ADVECTION JUST
NOTED FROM A 30-40 KT JET AT 850MB FROM LA CROSSE INTO NORTHERN
MISSOURI PER PROFILER DATA...AND A MOISTURE STREAM INDICATED BY
PRECIPITABLE WATER VALUES OF 0.75 TO 1.2 INCHES EXTENDING FROM THE
FORECAST AREA SOUTHWEST INTO MISSOURI. SCATTERED THUNDERSTORMS HAVE
ALSO OCCURRED...MAINLY SOUTH OF I-90 WHERE MUCAPE VALUES HAVE BEEN
UP AROUND 300 J/KG. ALONG AND NORTH OF I-94 WHERE TEMPERATURES ARE
IN THE LOW TO MID 30S...RESULTING FROM A COOLING AND DRYING EASTERLY
FLOW...PRECIPITATION IN THE FORMS OF RAIN...SLEET AND SNOW HAVE
OCCURRED. OTHER SHORTWAVES OF NOTE ON WATER VAPOR WITH MUCH LESS
GOING ON WERE PRESENT OVER WESTERN SOUTH DAKOTA AND FROM NORTHWEST
MINNESOTA INTO EASTERN MANITOBA. THE REASON FOR THE LACK OF ACTIVITY
WITH THESE WAVES IS MID-LEVEL DRYING...SEEN ON THE 00Z BIS...UNR AND
ABR SOUNDINGS. CLEARING LINE IS WELL OFF TO THE WEST...ALONG THE
DAKOTAS/MINNESOTA BORDER.
TODAY AND TONIGHT...CURRENT SHORTWAVE COMING INTO THE WESTERN
PORTION OF THE FORECAST AREA IS PROGGED TO MOVE ACROSS THE AREA
QUICKLY THIS MORNING...REACHING LAKE MICHIGAN BY 18Z. WITH THE FAST
PROGRESSION OF THE SHORTWAVE...ANTICIPATING ALL PRECIPITATION TO END
BY 15Z...AS PREVIOUS FORECASTS HAVE SUGGESTED. NEXT SHORTWAVE OVER
WESTERN SOUTH DAKOTA FOLLOWS QUICKLY ON ITS HEELS...CROSSING THE
FORECAST AREA LATE THIS AFTERNOON INTO THE EVENING...WITH WEAK UPPER
RIDGING THEN BUILDING IN AFTER MIDNIGHT. GIVEN LACK OF ANY ACTIVITY
UPSTREAM WITH THIS SHORTWAVE...ENVISION IT SHOULD COME THROUGH DRY.
IN FACT...THE MORE PROBLEMATIC ISSUE THROUGH TONIGHT IS CLOUD COVER.
SUBSIDENCE IN THE WAKE OF THIS MORNINGS SHORTWAVE...COMBINED WITH
RECENT MOISTURE AND AN EASTERLY LOW LEVEL FLOW...ALL WOULD SUGGEST A
CLOUDY-TYPE FORECAST IS THE WAY TO GO. DAYTIME MIXING SHOULD BE ABLE
TO GRADUALLY BREAK UP CLOUDS SOMEWHAT WEST OF THE MISSISSIPPI RIVER
THIS AFTERNOON. SOME HINTS THAT THIS CLEARING MAY SPREAD EAST INTO
WISCONSIN AFTER MIDNIGHT TONIGHT...RESULTING FROM PERSISTENT
SUBSIDENCE. ON THE OTHER HAND...CEILINGS COULD JUST LOWER INSTEAD.
ANOTHER ISSUE...WITH THAT RIDGING MOVING IN LATER TONIGHT...WARM
ADVECTION MID-CLOUDS LOOK TO RE-ENTER THE PICTURE...ESPECIALLY WEST
OF THE MISSISSIPPI RIVER. IN ADDITION...AM CONCERNED THAT LOW
STRATUS COULD RE-DEVELOP WHERE SKIES CLEAR WEST OF THE MISSISSIPPI
RIVER...RESULTING FROM RADIATIONAL COOLING AND AN UPSLOPING
SOUTHEAST WIND DEVELOPING. GIVEN THE CLOUD CONCERNS...GENERALLY TOOK
A BLEND OF ALL GUIDANCE FOR BOTH HIGHS AND LOWS. CONCERN DOES EXIST
THAT CENTRAL WISCONSIN ZONES COULD SEE FROST TONIGHT...BUT CLOUD
COVER ISSUES PRECLUDE ISSUING ANY ADVISORY AT THIS TIME.
SATURDAY AND SATURDAY NIGHT...THE WEAK UPPER RIDGING BUILDING OVER
THE AREA LATE FRIDAY NIGHT LOOKS TO CONTINUE INTO SATURDAY...
RESPONDING TO A POTENT SHORTWAVE TRACKING INTO NORTHERN ONTARIO.
UPPER RIDGING THEN RE-BUILDS BACK TO THE WEST OVER THE DAKOTAS
RESULTING FROM A DEEP SHORTWAVE TROUGH MOVING THROUGH CALIFORNIA.
DAYTIME MIXING IN CONJUNCTION WITH SUBSIDENCE UNDER THE WEAK UPPER
RIDGE SHOULD HELP BUST UP ANY MORNING LOW LEVEL STRATUS.
HOWEVER...BEING IN A WARM ADVECTION PATTERN AM CONCERNED THERE COULD
BE SOME LOW/MID CLOUDS TO DEAL WITH. BOTH THE NAM/GFS SHOW THESE
AROUND 800MB IN THE RH FIELDS...IN A NORTH-SOUTH BAND THAT MOVES
WEST TO EAST ACROSS THE FORECAST AREA THROUGH THE DAY. IN FACT...IF
YOU LIFT A PARCEL FROM 800MB IN THIS BAND...CAPE VALUES OF 300-500
J/KG ARE OBTAINABLE WITH NO CIN. ALTHOUGH NEITHER THE 30.00Z
GFS...NAM OR REGIONAL CANADIAN PRODUCE ANY QPF FROM THIS BAND...FEEL
COMPELLED TO HAVE SOME 20 PERCENT CHANCES. ACTUALLY...THE 30.00Z
UKMET PRODUCES A LITTLE LIGHT QPF. ON SATURDAY NIGHT...ANOTHER SURGE
OF ISENTROPIC LIFT NOTED ON 295-305K SURFACES IS PROGGED TO MOVE
INTO/THROUGH THE AREA. THE UKMET IS BY FAR THE MOST BULLISH WITH
CONVECTION...THOUGH THE HEAVIEST PORTION IS CENTERED OVER NORTHERN
ILLINOIS. THE 30.00Z GFS/NAM BOTH DEVELOP CONVECTION...MAINLY OVER
THE SOUTHEAST HALF BETWEEN 06-12Z SUNDAY. EITHER WAY...SOME
PRECIPITATION CHANCES ARE WARRANTED...WHICH HAVE BEEN RAISED ABOUT
10 PERCENT FROM THE PREVIOUS FORECAST. WITH MORE CLOUDS TO DEAL WITH
ON SATURDAY AND 925MB TEMPS ONLY REACHING 10-14C BY 00Z...LOWERED
HIGHS 3-4 DEGREES. CONTINUOUS WARM ADVECTION THROUGH MUCH OF
SATURDAY NIGHT SHOULD HELP TO KEEP TEMPERATURES UP AND PREVIOUS
FORECAST LOWS SEEM REASONABLE.
SUNDAY AND SUNDAY NIGHT...UPPER RIDGING OVER THE NORTHERN PLAINS IS
EXPECTED TO GRADUALLY SHIFT EAST...MOVING OVER THE FORECAST AREA
SUNDAY NIGHT. AGAIN...THIS IN RESPONSE TO THE DEEP TROUGHING OVER
THE WESTERN U.S. SLOWLY MOVING EAST. THIS UPPER RIDGE IS STRONGER
THAN THE PREVIOUS COUPLE ONES MOVING THROUGH...SO ITS SUBSIDENCE
SHOULD BE STRONGER. INDEED...MOST MODELS KEEP THE FORECAST AREA DRY
THROUGH SUNDAY NIGHT AND HAVE TRENDED THE FORECAST IN THIS
DIRECTION. THIS LEAVES TEMPERATURES THE BIGGER ISSUE. WITH A MORE
AMPLIFIED LOOK TO THE UPPER RIDGING...THAT WARM FRONT MENTIONED IN
PREVIOUS DISCUSSIONS TO COME THROUGH ON SUNDAY MAY END UP STAYING
ALONG OR SOUTH OF I-90. IN FACT...THE 30.00Z GFS/UKMET HINT AT
BACKDOOR COLD FRONT POTENTIAL. STILL...IT SEEMS LIKE A SOLID BET FOR
SUNDAY TO END UP QUITE A BIT WARMER THAN SATURDAY...ESPECIALLY WEST
OF THE MISSISSIPPI RIVER WHERE 925MB TEMPERATURE CONSENSUS SUGGESTS
READINGS OF 20-22C. CLOSER TO CENTRAL WISCONSIN...14-16C READINGS
SHOULD BE MORE COMMON. WITH THE COOLER TREND NOTED IN MODELS...DID
KNOCK HIGHS BACK A FEW DEGREES OVER WISCONSIN AREAS. FURTHER
LOWERING MAY BE REQUIRED DEPENDING ON THE BACKDOOR COLD FRONT
POTENTIAL. WARM AIR SHOULD HOLD IN HERE SUNDAY NIGHT...IN
COMBINATION WITH THE UPPER RIDGE AND WITH A LOW PRESSURE SYSTEM
TRYING TO APPROACH THE AREA FROM THE CENTRAL PLAINS. PREVIOUS LOW
TEMPERATURE FORECAST LOOKS ON TRACK.
.LONG TERM...MONDAY THROUGH THURSDAY NIGHT
329 AM CDT FRI MAR 30 2012
TREND IN THE RECENT 30.00Z GFS/ECMWF/UKMET/CANADIAN IS TO SUGGEST
THAT THE WESTERN TROUGHING IS GOING TO SPLIT INTO TWO. THE SOUTHERN
END CUTS OFF OVER TEXAS FOR MUCH OF THE LONG TERM PERIOD...WHILE THE
NORTHERN END COMES THROUGH THE FORECAST AREA ON TUESDAY. THIS IS
SLOWER THAN PREVIOUSLY FORECAST...AND IN FACT IF THE 30.00Z ECMWF IS
CORRECT...MONDAY COULD BE A VERY WARM AND EVEN HUMID DAY ACROSS MUCH
OF THE FORECAST AREA. SUGGESTION FROM THE MODEL IS HIGHS IN THE LOW
80S AND DEWPOINTS IN THE LOW 60S...ALL FROM THE LOW PRESSURE SYSTEM
IN THE CENTRAL PLAINS LIFTING NORTHEAST INTO NORTHWEST WISCONSIN.
HAVE NOT JUMPED ON THIS SCENARIO QUITE YET...SINCE MOST MODELS KEEP
THIS SYSTEM TO THE SOUTH OF THE AREA...BUT DEFINITELY WARRANTS
WATCHING. ALSO THE ECMWF WOULD SUGGEST SOME STRONG CONVECTION AT
LEAST AS THE COLD FRONT COMES THROUGH. NEEDLESS TO SAY...CHANCES OF
PRECIPITATION CONTINUE IN THE FORECAST FOR MONDAY INTO MONDAY
NIGHT...MAINLY IN THE 20-40 RANGE UNTIL THIS WHOLE SYSTEM CAN BE
IRONED OUT. DRYING TREND THEN IS FORECAST FOR TUESDAY AND CONTINUING
THROUGH THE REST OF THE LONG TERM PERIOD WITH MOST MODELS AND
ENSEMBLES SHOWING NORTHWEST FLOW OVER THE FORECAST AREA. DID KEEP A
20 PERCENT CHANCE OF SHOWERS GOING ON TUESDAY WITH THE UPPER TROUGH
MOVING THROUGH...THOUGH. HOW MUCH NORTHWEST FLOW AND THE COLD AIR
ASSOCIATED WITH IT VARIES...SO FOR NOW STAYED WITH A BLEND OF MODELS
FOR TEMPERATURES. READINGS STILL LOOK TO STAY ABOVE NORMAL AS HIGHS
ONLY DROP INTO THE MID TO UPPER 50S AT THE LOWEST. NORMAL HIGHS ARE
IN THE LOW 50S.
&&
.AVIATION...TODAY AND TONIGHT
615 AM CDT FRI MAR 30 2012
PLAN ON IFR CONDITIONS IN LOW STRATUS AT THE TAF SITES THROUGH MID
MORNING. LOOK FOR CEILINGS IN THE 600 TO 900 FT RANGE. IN
ADDITION...VISIBILITIES WILL BE REDUCED TO AROUND 5 SM IN BR. THE
LOW STRATUS SHOULD LIFT INTO AN MVFR STRATUS DECK THIS AFTERNOON
AS THE PRESSURE GRADIENT TIGHTENS ACROSS THE AREA WITH HIGH PRESSURE
ATTEMPTING TO BUILD IN FROM THE NORTHEAST. CLOUD BASES ARE
EXPECTED TO RISE TO AROUND 2 KFT BY EARLY THIS AFTERNOON...AND
POSSIBLY INCREASING TO AROUND 3500 FT IN THE 22Z-00Z TIMEFRAME.
FORECAST SOUNDINGS ARE SHOWING THE STRATUS LOWERING AGAIN TONIGHT
INTO THE IFR CATEGORY. THE INCREASING PRESSURE GRADIENT SHOULD
KEEP WINDS JUST ABOVE THE SURFACE IN THE 10 TO 15 KT
RANGE...PREVENTING FOG DEVELOPMENT. PLAN ON CEILINGS LOWERING INTO
THE 600 TO 900 FT RANGE AGAIN LATE THIS EVENING AND PERSISTING
THROUGH THE OVERNIGHT HOURS. IF LESS WIND IS REALIZED...FOG WILL
BE POSSIBLE ESPECIALLY AT KLSE WHERE DECOUPLING COULD OCCUR.
&&
.HYDROLOGY...
329 AM CDT FRI MAR 30 2012
AS OF 3 AM...MAJORITY OF THE PRECIPITATION SO FAR HAS FALLEN
ALONG AND SOUTH OF A LINE FROM ST ANSGAR IOWA TO WINONA MN AND
BLACK RIVER FALLS WISCONSIN. RADAR ESTIMATES SHOW THAT THE SHOWERS
AND THUNDERSTORMS PRODUCED AMOUNTS RANGING FROM 0.25 TO 0.75
INCHES. HOWEVER...THERE IS AN AREA COVERING SOUTHEAST
FAYETTE...MUCH OF CLAYTON AND NORTHERN GRANT COUNTIES WHERE 0.75
TO 1.75 INCHES FELL...HIGHEST NEAR STRAWBERRY POINT. NO REPORTS OF
ANY FLOODING THUS FAR BUT EXPECT SOME BRIEF RISES IN SMALL
STREAMS. WILL HAVE TO KEEP AN EYE ON THE TURKEY RIVER...THOUGH
THE LACK OF SIGNIFICANT RAINFALL AND GENERALLY DRY SOILS SHOULD
KEEP THE RIVER BELOW FLOOD STAGE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
328 AM CDT FRI MAR 30 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1026 AM MDT FRI MAR 30 2012
.UPDATE...WINDS HAVE INCREASED BEHIND WAVE THAN PASSED THROUGH THE
AREA THIS MORNING. APPEARS SUBSIDENCE PLAYING A ROLE IN THE WINDS.
12Z NAM CROSS SECTIONS DID SHOW CROSS MOUNTAIN FLOW CLOSE TO 50
KTS AT MOUNTAIN TOP ALONG WITH WEAK MOUNTAIN WAVE THROUGH 18Z. SO
QUESTION FOR TODAY IS HOW LONG THESE WINDS WILL CONTINUE. NAM
CONTINUES SOME SORT OF WESTERLY...EVEN NORTHWEST...COMPONENT
THROUGHOUT THE AFTERNOON...WHILE GFS AND RUC DEVELOP A CYCLONE IN
THE DENVER AREA BY 19Z WITH MORE OF AN EASTERLY COMPONENT. WINDS
ALOFT WILL REMAIN NORTHWEST THROUGH THE EVENING...THOUGH ON THE
DECREASE AS RIDGE TRIES TO BUILD INTO THE REGION. FOR THIS
UPDATE...WILL LEAN TOWARD THE NAM SOLUTION...THOUGH NOT AS STRONG
WITH THE WINDS. FEEL THERE WILL BE ENOUGH MIXING TO OFFSET THE
CYCLONE. SO ONLY CHANGE TO CURRENT GRIDS WILL BE TO TWEAK THE
WINDS GRIDS A BIT INTO THE AFTERNOON. CURRENT THINKING IS THAT
WINDS ACROSS THE AREA SHOULD BE DECREASING A BIT AND SPEEDS NOT
EXPECTED TO MEET THE RED FLAG CRITERIA...BUT WILL CONTINUE TO
MONITOR IF ANY HILITES ARE NEEDED. AS FOR THE FIRE AREA...STILL
THINKING DIURNAL UPSLOPE CONDITIONS SHOULD PREVAIL TODAY.
&&
.AVIATION...WILL MAINTAIN WSW WINDS AT DIA AND BJC THROUGH ABOUT 19Z
THEN MORE OF A NORTHWEST DIRECTION...WITH SPEEDS IN THE 12-18 KT
RANGE. STILL SOME CHANCE OF A DENVER CYCLONE DEVELOPING...AS
SHOWN BY THE GFS AND RUC SOLUTIONS...WITH MORE OF AN EASTERLY
COMPONENT. WILL HOLD OFF ON THE EASTERLY DIRECTION FOR NOW.
OTHERWISE...REST OF TAF TRENDS...INCLUDING APA TRENDS...SEEM ON
TRACK.
&&
.PREV DISCUSSION... /ISSUED 418 AM MDT FRI MAR 30 2012/
..CORRECTION FOR A FEW TYPOS AND MISSING WORDS
SHORT TERM...A WEAK SHORT WAVE CURRENTLY OVER EASTERN COLORADO
WILL CONTINUE TO PUSH EAST THIS MORNING. THIS BROUGHT SOME MID
AND HIGH CLOUDS OVERNIGHT. DOWNWARD MOTION AND DRIER AIR BEHIND IT
WILL BRING MOSTLY SUNNY SKIES THIS MORNING. MODELS SHOWING HIGH
CLOUDS INCREASING LATE THIS AFTERNOON AND EARLY EVENING. THERE
WILL BE SOME RIDGING IN THE FLOW ALOFT TODAY. THE AIRMASS WILL
WARM 3-6 DEGREES FAHRENHEIT FROM YESTERDAY...RESULTING IN HIGHS
IN THE MID TO UPPER 70S TODAY ACROSS NORTHEAST COLORADO. FAR
NORTHEAST COLORADO WILL SEE BREEZY CONDITIONS TODAY. WINDS AND
HUMIDITY WILL BE CLOSE TO RED FLAG WARNING CRITERIA TODAY...BUT DO
NOT EXPECT THEM TO MEET CRITERIA FOR THE REQUIRED TIME...3 HOURS.
AREAS WEST OF THE CONTINENTAL DIVIDE WILL ALSO SEE BREEZY
CONDITIONS WITH GUSTS TO 25 MPH.
LONG TERM...A POTPOURRI OF WEATHER TO CONTEND WITH IN THE
EXTENDED PERIOD OF THE FORECAST. WE/LL BEGIN WITH THE UNSEASONABLY
WARM IF NOT RECORD BREAKING TEMPERATURES ANTICIPATED ON SATURDAY AND
NOW IT LOOKS LIKE SUNDAY...TOO. FOR SATURDAY...STATE WILL BE
UNDERNEATH AN UPPER RIDGE EXTENDING FM MEXICO TO THE CANADIAN
BORDER. 700 MB TEMPERATURES ALONG THE FRONT RANGE PROGGED TO BE IN
THE 10-12C RANGE WHICH WHEN BROUGHT DOWN TO THE SFC DRY
ADIABATICALLY EQUATES TO HIGH TEMPERATURES IN THE LOWER/MID 80S ON
THE PLAINS. RECORD HIGH AT DENVER ON SAT IS 80F. WOULDN/T THINK WE
WOULD HAVE ANY PROBLEM BREAKING THAT AS LONG AS THE HIGH LEVEL CLOUD
COVER EXPECTED THAT DAY DOESN/T BECOME TOO THICK. IT EARLIER LOOKED
AS THOUGH WE COULD SEE RED FLAG WARNING CONDITIONS ON
SATURDAY...MAINLY REFERRING TO STG AND GUSTY SOUTH-SOUTHWEST WINDS.
NO LONGER APPEARS TO BE THE CASE WITH THE SLOWER EASTWARD PROGRESS
OF THE UPPER RIDGE... WINDS SFC AND ALOFT NOT EXPECTED TO BE ALL
THAT STRONG. HIGH COUNTRY COULD SEE QUITE OF BIT OF SNOW MELT EVEN
AT THE HIGHEST ELEVATIONS...BUT HEAVY SNOWMELT RUNOFF IS NOT LIKELY
TO BE A PROBLEM.
BY SUNDAY..MODELS SHOW THE UPPER RIDGE MOVING OVER THE GREAT PLAINS
CAUSING THE FLOW ALOFT TO GO SOUTHWESTERLY. WINDS ALOFT ARE FCST TO
STRENGTHEN THRU THE DAY. COULD SEE THIS MOMENTUM MIXING DOWN TO THE
SFC ON THE PLAINS BY AFTERNOON WITH GUSTS IN THE 20-30 MPH RANGE ON
THE PALMER DIVIDE AND OUT ACROSS LINCOLN AND WASHINGTON COUNTIES.
WILL NEED TO MONITOR THIS TO SEE HOW THIS DEVELOPS AS A FIRE WEATHER
WATCH MAY BE NECESSARY OUT THERE.
THEN ALL THIS HEAT AND DRYNESS COMES TO AN END SUNDAY NIGHT WITH A
STRONG COLD FRONT BARRELING SOUTH ALONG THE FRONT RANGE OVERNIGHT
AND A FULL LATITUDE MULTI-LAYER TROUGH MOVES OVER COLORADO. MODELS
HAVE HAD A HECK OF A TIME WITH THIS SYSTEM THE PAST FEW DAYS. ONE
MINUTE THEY SHOW AN OPEN WAVE...THE NEXT A DEEP CLOSED LOW. HOWEVER
THE PAST TWO RUNS OF THE EC HAVE COME MORE IN LINE WITH THE
GFS...NAM AND CANADIAN GEM WHICH SHOW THIS SYSTEM DIPPING AND
FORMING A CLOSED LOW IN THE 4-CORNERS AREA LATE SUNDAY NIGHT. THE
LATEST 06Z RUN OF THE NAM SHOWS AN EVEN DEEPER SYSTEM NOW. ANYHOW...
MODELS MOVE THIS TROUGH/UPR LOW ALONG WITH MUCH COOLER AND WETTER
AIR ACROSS THE AREA ON MONDAY. COULD SEE PCPN IN THE FROM OF RAIN
AND SNOW AT LOWER ELEVATIONS MONDAY MORNING AND LATER MONDAY AFTN
AND EVENING. FOR NOW WILL STICK WITH SCATTERED POPS. HIGH
ELEVATIONS...PARTICULARLY THE EAST FACE OF THE FRONT RANGE...HAS THE
POTENTIAL TO SEE MEASURABLE SNOWFALL SHOULD WE SEE THIS SYSTEM
WRAPPING AS MODELS NOW INDICATE. MAY NOT CLIMB OUT OF THE 40S AT
LOWER ELEVATIONS ON THE PLAINS...COLDEST WE/VE SEEN IN QUITE SOME
TIME.
LOOKING AHEAD...SYSTEM SLOWLY MOVES OUT WITH TEMPERATURES
RETURNING ABOVE AVERAGE BY MIDWEEK AND POSSIBLY BACK TO THE 80 DEG
MARK ON THE PLAINS BY THE END OF THE WEEK UNDER A BIG RIDGE OF
HIGH PRESSURE.
AVIATION...THERE WILL BE PERIODS OF HIGH CLOUDS THROUGH THE NEXT
24 HOURS. NORMAL DRAINAGE WINDS THIS MORNING TO SHIFT WESTERLY THIS
AFTERNOON. EXPECT A PERIOD OF LIGHT AND VARIABLE WINDS LATE THIS
MORNING. WINDS WILL REMAIN LIGHT TODAY...LESS THAN 12 KNOTS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....BAKER
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
203 PM EDT FRI MAR 30 2012
.AVIATION..
RISK FOR THUNDER HAS DIMINISHED AT KSBN WITH MAIN ACTIVITY TO
REMAIN EAST AND SOUTH OF THE AREA. SHOWERS WILL REMAIN POSSIBLE
UNTIL PASSAGE OF THE LOW...WITH PATCHY LIGHT RAIN OR DRIZZLE IN
ITS WAKE AS STRATUS MOVES IN FOR THE REMAINDER OF THE NIGHT. AT
KFWA...TRICKY FORECAST REMAINS. ACTUAL WARM FRONT STILL RESIDED
SOUTH OF KFWA BUT MAY MAKE A BRIEF EXCURSION IN FOR A FEW HOURS.
STRONGEST STORMS WILL LIKELY REMAIN JUST SOUTH OF KFWA...BUT WILL
BE A CLOSE CALL. ONLY CHANGE TO TEMPO GROUP WAS TO SPEED UP
ARRIVAL BY AN HOUR WITH INITIAL SURGE OF CONVECTION DEVELOPING
WEST OF THE AIRPORT.
AFTER FROPA...SKIES WILL FILL BACK IN WITH STRATUS WHICH WILL
LINGER INTO SAT MORNING.
&&
.UPDATE...
UPDATE ISSUED TO INCREASE TEMPS IN THE FAR SOUTH AND ADJUST
CONVECTIVE THREAT SOMEWHAT SOUTHWARD. SCT LINE OF SHOWERS AND
STORMS HAS FORMED ALONG WEAK WAVE MOVING THROUGH THE AREA. THIS
SHOULD REMAIN ELEVATED AND MUCH LIKE THIS MORNING SHOULD NOT POSE
A SEVERE THREAT. MAIN AREA TO BE WATCHED WILL BE SE THIRD OF THE
FORECAST AREA...ROUGHLY SOUTH OF A LOGANSPORT TO FT WAYNE TO
PAULDING LINE. STILL LOOKS LIKE IT WILL BE A SMALL WINDOW OF
OPPORTUNITY FOR SEVERE TO OCCUR...MAINLY BETWEEN 20Z AND 23Z. WITH
INCREASING CLOUD COVER ALONG THE FRONT...HAVE SOME RESERVATIONS
ABOUT SEVERE POTENTIAL WITH 60+ DEWPTS REMAINING JUST TO THE
SOUTH. HOWEVER...WILL SIDE WITH RUC13 AND NAM 12 AND KEEP WITH SVR
THREAT.
&&
.PREV DISCUSSION... /ISSUED 444 AM EDT FRI MAR 30 2012/
SHORT TERM.../TODAY THROUGH SAT NGT/
BROAD SFC LOW OVER IA/SWRN MN THIS MORNING EXPECTED TO CONSOLIDATE
AND DEEPEN AS IT MOVES ESE THROUGH A CHICAGO-FWA-LIMA LINE TODAY.
LARGE CLUSTER OF TSTMS TO E-NE OF THE SFC LOW IN AREA OF LOW LEVEL
THETA-E ADVECTION AND UPR LEVEL DIV. IR IMAGERY SHOWING TREND OF WARMING
OF CLOUD TOPS IN THIS AREA... BUT NEW CONVECTION DVLPG FARTHER
EAST ACROSS NW INDIANA. EXPECT MUCH OF THE CWA WILL HAVE SHOWERS
AND TSTMS THIS MORNING...BUT GREATEST COVERAGE BTWN 12Z-18Z
EXPECTED TO BE ACROSS NW 1/2 OF CWA ASSOCIATED WITH TSTM CLUSTER
CURRENTLY MOVG THROUGH NW IL/SW WI.
TRACK OF SFC LOW ACROSS THE AREA TODAY SHOULD RESULT IN A LARGE
TEMP GRADIENT WITH 40S IN OUR MI COUNTIES AND NR 70 IN THE SRN
TIER OF OUR INDIANA COUNTIES THIS AFTN. NAM AND LOCAL 12KM WRF
INDICATE MODERATE INSTABILITY WILL DVLP OVER SRN PORTION OF OUR
CWA THIS AFTN WITH 1000-1500J/KG MLCAPE AND RATHER STRONG 0-6KM
SHEAR OF 30-40KT. SPC 4KM WRF SUGGESTS TSTMS WILL DEVELOP ALONG
THE CDFNT THIS AFTN AS IT MOVES THROUGH THIS ENVIRONMENT ACROSS
SRN PORTION OF OUR CWA. DISCREET STORMS EXPECTED TO QUICKLY
TRANSITION INTO A LINE AND RACE EASTWARD ACROSS SRN PORTION OF THE
AREA BETWEEN 18-00Z. CONT TO THINK AREAS ALONG AND SOUTH OF A
RCR-FDY LINE ARE AT GREATEST RISK OF SVR STORMS THIS AFTN... BUT
DEPENDING ON EXACT TRACK OF LOW AND SUBSEQUENT NORTHWARD ADVANCE
OF WARM SECTOR... THREAT COULD EXTEND FARTHER NORTH A COUPLE MORE
COUNTIES INTO NRN INDIANA AND NW OH PER LATEST SPC DAY1 OUTLOOK.
AS LOW CONTS ESE ACROSS THE UPR OH VALLEY TONIGHT... LOW LEVEL CAA
SHOULD RESULT IN WIDESPREAD LOW CLOUDS OVER THE AREA WHICH WILL
PERSIST INTO SATURDAY MORNING. SKIES SHOULD CLEAR SAT AFTN AS SFC
RIDGE MOVES ACROSS THE AREA. DESPITE WK LOW LEVEL FLOW/WAA... EXPECT
AFTN SUNSHINE WILL ALLOW TEMPS TO REACH THE MID/U50S OVER MOST OF
THE CWA. GOOD RADIATIONAL COOLING EARLY SAT NGT SHOULD GIVE WAY TO
INCREASING WAA/CLOUDS/GRADIENT WINDS LATE AS RIDGE MOVES TO THE EAST
AND A WK CDFNT DROPS SE ACROSS THE UPR GRTLKS. GIVEN THIS
SCENARIO...GENERALLY LEANED TOWARD WARMER GUIDANCE VALUES.
LONG TERM...
SUNDAY THROUGH THURSDAY...THE MAIN CHALLENGE THIS PERIOD INCLUDES
THE TIMING AND TRACK OF SHORT WAVE ENERGY EJECTING EAST EARLY NEXT
WEEK. THE PERSISTENT PATTERN OF A NEGATIVE HEIGHT ANOMALY ALONG AND
OFF THE WESTERN COAST OF NORTH AMERICA WILL CONTINUE TO KEEP RATHER
EXTENSIVE UPPER LEVEL RIDGING OVER THE NORTH AMERICAN INTERIOR. FOR
THIS PACKAGE...USED A ECMWF/GFS/CANADIAN GEM ENSEMBLE BLEND WITH
ANALOGS. THE ONGOING CHANCES FOR SHOWERS AND THUNDERSTORMS MONDAY
NIGHT AND TUESDAY APPEAR ON TRACK. IT LOOKS LIKE A PORTION OF THE
SHORT WAVE ENERGY WILL SHEAR OUT TO THE NORTHEAST WITH SOME TYPE OF
CUT OFF LOW LINGERING TO THE SOUTH OR SOUTHWEST OF THE AREA. SEVERE
STORMS ARE PLAUSIBLE GIVEN CAPES APPROACHING 2000 J/KG WITH UPPER
LEVEL SUPPORT. IT HAS BEEN REAL HARD TO TAP MUCH COLD AIR BEHIND
THESE SYSTEMS THE PAST SEVERAL WEEKS. THE BEST CHANCE FOR COLD AIR
AND FREEZING TEMPERATURES IS LATE IN THE PERIOD AS NORTH TO
NORTHEAST FLOW SETS UP WITH A SURFACE RIDGE EXTENDING SOUTH FROM
JUST WEST OF HUDSON BAY. OTHERWISE...WENT WITH THE HIGH END CANADIAN
AND GFS ENSEMBLE MEMBERS WITH HIGHS WELL INTO THE 70S SUNDAY AND
MONDAY GIVEN 850 MB TEMPS 14C TO 17C.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...JT
LONG TERM...SKIPPER
AVIATION...FISHER
UPDATE...FISHER
AREA FORECAST DISCUSSION
NWS WICHITA KS
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
&&
.AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
LIGHT WINDS AND CLEAR SKIES ANTICIPATED THROUGH THE NEXT 24
HOURS FOR MOST TERMINALS...ALTHOUGH KCNU SHOULD SEE SOME
SCT025-035 CUMULUS THIS AFTERNOON. ADDITIONALLY...CANNOT RULE OUT
A STRAY AFTERNOON/EVENING THUNDERSTORM FOR KICT-KCNU ALONG VERY
WEAK CONVERGENCE ZONE AHEAD OF SHORTWAVE ENERGY APPROACHING FROM
THE NORTHWEST. HOWEVER...THESE CHANCES ARE QUITE LOW.
OTHERWISE...DIURNAL COOLING IN CONCERT WITH LIGHT WINDS AND MOIST
LOW-LEVELS COULD PROMOTE SOME PATCHY FOG TONIGHT-EARLY
SATURDAY...AFFECTING MAINLY KICT-KHUT-KCNU. FOR NOW ONLY WENT
3-5SM VSBYS...ALTHOUGH PATCHY VSBYS COULD GO BRIEFLY LOWER.
ADK
&&
.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 LOUISVILLE KY
410 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 (18Z TAF Issuance)...
Updated at 105 PM EDT Mar 30 2012
Surface warm frontal boundary has now cleared all the terminals and
southwesterly flow is picking up across the region. Partly to
mostly sunny skies are expected through the early afternoon hours,
but a distinct Cu field is already developing in the warm sector,
south of the warm front. Can not completely rule out an isolated
thunderstorm or two across the region this afternoon, but feel that
the best convective potential will increase this afternoon to our
northwest along an approaching frontal boundary. Scattered-broken
line of storms will likely develop out ahead of this boundary and
head east-southeastward across the area this evening. Feel that the
best chances of convection at KSDF/KLEX will be between
30/23Z-31/06Z. Given the uncertainty in the timing, will keep
VCTS going in the TAFs for now. Further south at KBWG, storms may
not be an issue tonight as the line is expected to weaken due to the
loss of instability as it heads southward into KY. Will maintain a
VCTS group after 31/04Z. After cold frontal passage late tonight,
we`ll see winds kick around to the northwest and then eventually to
the northeast during the day on Saturday.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Short Term.......MJ
Long Term........BJS
Aviation.........MJ
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1255 PM CDT FRI MAR 30 2012
.UPDATE...
ISSUED AT 1253 PM CDT FRI MAR 30 2012
LATEST UPDATE INCLUDES NEW AVIATION SECTION AND LONG TERM UPDATE.
UPDATE ISSUED AT 1233 PM CDT FRI MAR 30 2012
REFINED THE TIMING AND INTENSITY OF THE POP/WEATHER GRIDS FOR THE REST
OF TODAY AND INTO TONIGHT. ADJUSTMENTS WERE ALSO MADE TO REFINE OTHER
SENSIBLE WEATHER ELEMENTS...SUCH AS TEMPERATURE...DEWPOINT...WIND...SKY
COVER AND RELATIVE HUMIDITY.
WITH THE MANDATORY LEVEL UPPER AIR ANALYSIS...THERE WAS A MAXIMUM
OF HIGHER THETA-E AIR OVER SOUTHEAST OK...NORTHERN AR...AND
SOUTHEAST MISSOURI THIS MORNING...WITH A SECONDARY AREA OVER
NORTHERN AND NORTHEAST ILLINOIS. THE BEST LOW LEVEL MOISTURE WAS OVER
WEST KENTUCKY...SOUTHEAST ILLINOIS AND SOUTHWEST INDIANA.
THE 12KM NAM-WRF AND 3KM HRRR NUMERICAL MODEL
MASS/INSTABILITY/RADAR REFLECTIVITY FIELDS SUGGEST THAT THE
NORTHERN INDIANA CONVECTION AND NEWLY MINTED CENTRAL KENTUCKY CONVECTION
SHOULD GRADUALLY BUILD WESTWARD WITH TIME. THE 0-3/3-6KM NAM-WRF BULK
SHEAR REMAINS LOW /15-25 KNOTS/...SO SIGNIFICANT STORM
ORGANIZATION MAY NOT BE IN THE CARDS FOR THE AREA. HOWEVER...SHARP
LAPSE RATES AND DECENT CAPE/DOWNDRAFT CAPE SUGGEST THE POTENTIAL
THAT GOOD UPDRAFTS WILL WARRANT THE MENTION OF AT LEAST SMALL HAIL
AND GUSTY WINDS IN THE GRIDDED FORECAST THIS AFTERNOON AND INTO
THE EARLY EVENING HOURS. AT THIS TIME...FOCUSED THIS MENTION OF
HAIL/WIND IN THE SCATTERED THUNDERSTORM COVERAGE AREA.
THE NAM-WRF/GFS/RUC APPEARED TO INITIALIZE BETTER WITH INSTABILITY
/LIFTED INDEXES/ AND PRECIPITABLE WATER FROM THE GOES SOUNDER
IMAGERY VERSUS THE REST OF THE MODEL GUIDANCE THIS MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 1233 PM CDT FRI MAR 30 2012
IN LINE WITH THE MIDNIGHT SHIFT ADJUSTMENT FOR POPS/WEATHER
TONIGHT INTO SATURDAY...ADJUSTED AND SLIGHTLY INCREASED RAIN
CHANCES MAINLY OVER SOUTHEAST MISSOURI. GIVEN THE STRONGER DRY AIR
ADVECTION AHEAD OF THE FRONTAL BOUNDARY ON SATURDAY...KEPT RAIN
CHANCES OUT OF A VAST MAJORITY OF SOUTHERN ILLINOIS AND WEST
KENTUCKY AND ALL OF SOUTHWEST INDIANA.
RIDGING ON SUNDAY STILL REMAINS DOMINANT...SO LOW TO MIDDLE 80S
AND LIMITED CLOUD COVER REMAIN ON TARGET IN THE FORECAST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 1253 PM CDT FRI MAR 30 2012
GENERALLY THE GFS HAS BEEN MORE CONSISTENT IN BRINGING ENERGY OUT OF
THE SOUTHWEST U.S. EARLY IN THE WEEK...IN THE FORM OF A CUT OFF AS
IT MOVES ACROSS THE SOUTHERN PLAINS AND TOWARD THE MISSISSIPPI
VALLEY REGION. THE GFS AND GEM MODELS ARE IN DECENT AGREEMENT AND
WE GENERALLY USED A BLEND OF THE TWO AS A GUIDE.
H5 RIDGING ACROSS THE REGION SHOULD KEEP MONDAY ESSENTIALLY DRY.
CANNOT RULE OUT SOMETHING ISOLD...BUT TOO LOW OF A CHANCE TO MENTION
AT THIS TIME. CHANCES OF CONVECTION WILL INCREASE FROM LATE MONDAY
NIGHT THROUGH TUESDAY AS SOME ASSEMBLANCE OF THE CUT OFF APPROACHES
THE REGION FROM THE WEST. WILL CONTINUE CHANCES THROUGH WEDNESDAY
AND THEN LEAVE THE REST OF THE FORECAST DRY FOR NOW. WE MAY WITH
TIME NEED TO LINGER POPS FOR CONVECTION BEYOND WEDNESDAY. BUT GIVEN
THE DEGREE OF LOW CONFIDENCE/UNCERTAINTY...PREFER TO WAIT UNTIL
LATER SOLUTIONS SHOW A MORE CONSISTENT TREND DAY 6 AND BEYOND.
MONDAY WILL START OFF UNSEASONABLY WARM...NOTHING NEW THIS EARLY
SPRING. ONCE THE UPPER LOW BECOMES A FACTOR...TEMPERATURES SHOULD
LOWER TO CLOSER TO NORMAL VALUES FOR EARLY APRIL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1253 PM CDT FRI MAR 30 2012
GENERALLY KEPT THE TAFS SIMPLE GIVEN LOW PROBABILITIES OF CONVECTION
AT ANY GIVEN POINT. DEPICTED CU AND SSW WINDS GUSTY THROUGH LATE
AFTERNOON. KEPT CB MENTION GOING UNTIL WINDS SHIFT AROUND LATER
TONIGHT TO NNE. UPDATES MAY BE REQUIRED SHOULD CONFIDENCE INCREASE
THAT CONVECTION WILL DIRECTLY AFFECT THE TERMINALS.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
147 PM EDT FRI MAR 30 2012
.Forecast Update...
Issued at 145 PM EDT Mar 30 2012
Surface analysis, observations and satellite data confirm that the
warm front now has lifted northward across the region. In the warm
sector, south of the front, SW-NE oriented enhanced Cu field has
rapidly developed. With temperatures in the upper 70s and the
dewpoints in the upper 50s, this has resulted in increased
atmospheric instability. Objective analysis suggests that
mixed-layer CAPE values are in the 1000-1500 J/Kg range with surface
LI`s now dipping below 0 degrees C. RUC proximity soundings still
show a bit of CINH out to our west and that agrees well with recent
high-res satellite imagery showing relatively little Cu development
west of the Natcher/Green River Parkway region. Within the area of
increasing CAPE, isolated convection has recently develop. Given
the increasing instability and relatively weak shear, multi-cellular
convection is likely to continue, but probably will remain
disorganized to an extent. Pulse type hailers, and downbursts will
be possible with this activity as we head into the afternoon hours.
Feel that convection will likely remain fairly isolated but
gradually become scattered as more instability develops. Given the
SW-NE oriented Cu field along the developing horizontal convective
rolls, most convection should head northeastward.
Additional convection is likely to fire later this afternoon from
central IL into central IN ahead of an approaching cold front.
Convective activity now starting to develop across NE IN and far NW
OH closer to the upper dynamics and surface low pressure system.
Expect convection to backbuild to the southwest later this afternoon
and then begin to sink southward through the evening hours. This
line of convection will likely impact our southern Indiana counties
early this evening with areas along the Ohio River and extreme
northern KY getting in on the action probably in the mid-late
evening hours. Main threats still look to be damaging winds and
large hail.
Update issued at 1155 AM EDT Mar 30 2012
Will do a quick update to freshen up the forecast a bit. Backed off
on the cloud cover across the region based on the current satellite
imagery. Mostly sunny skies are expected through the afternoon and
this will allow good diurnal heating to take place. Some Cu may
develop later this afternoon...but partly to mostly sunny skies are
generally expected. Cold front is still well northwest of the
region and convection is expected to fire along this front later
this afternoon...mostly likely after 4PM EDT. Current temperature
forecast still looks good with mid-upper 70s in the Bluegrass region
and upper 70s to lower 80s elsewhere.
Current 12Z data is now ingesting and we`ll address this afternoon
and evening`s convective potential in the next update which will be
a few hours from now.
Update issued at 756 AM EDT Mar 30 2012
Going to do a quick update to add some isolated rain showers to the
Bluegrass region. Surface warm front is pushing through the central
sections of the forecast area this morning. As a result, a few
isolated showers have continue to develop here and there across our
northeastern third. These very isolated showers should continue for
the next 1-2 hours and then diminish. Rest of the forecast looks on
track and only minor adjustments to the remainder of the elements
will be done.
.Short Term (Today through Saturday)...
Issued at 220 AM EDT Mar 29 2012
Convection over Iowa earlier this morning was associated with a
flat progressive 500mb wave that is forecast to dig slightly across
Ohio by early Saturday. At the surface, low pressure will move east
across central Indiana late this afternoon.
At the moment, a warm front extends from low pressure across northern
Missouri southeast across western Kentucky and northern Tennessee.
Well north of this surface feature, lift along an elevated boundary
will allow scattered showers to move east towards southern Ohio
during the pre-dawn hours. These showers will have departed the
northern Bluegrass by 6 am this morning. Feel that much of today
will be dry through at least mid-afternoon.
As the warm front lifts north of the Commonwealth by early
afternoon, southwest winds will increase as central Kentucky will
find itself totally within the warm sector of the disturbance to our
north. Afternoon highs will range from the upper 70s to the lower
80s today with south winds increasing this afternoon to 10 to 15 mph
with some higher gusts. Expect mostly clear skies today with partly
cloudy skies across southern Indiana and the northern Bluegrass.
A cold front will cross into Kentucky late this evening. The 00z SPC
WRF model depicts a scattered to broken line of storms developing
across southern Indiana late this afternoon, then crossing the Ohio
River this evening. Despite better dynamics farther northeast closer
to the surface low, moderate to strong instability coupled with
steep lapse rates and unidirectional winds from the west may lead to
some scattered severe storms. Feel the best chance of large hail or
damaging winds will lie north of interstate 64 around early to mid
evening. Expect that thunderstorm intensity and coverage will
decrease a bit before this weakening line reaches the Tennessee
border early Saturday. Behind this front, residual low level
moisture will lead to mostly cloudy skies through Saturday morning.
Distinctly cooler air will invade southern Ohio behind yet another
in a recent series of backdoor cold fronts. The NAM is much more
aggressive than the GFS in cooling off the northern Bluegrass for
Saturday, suggesting that highs will struggle to reach 60. Will
trend toward the warmer GFS and forecast a wide range for high
temperatures, varying from the lower 60s south of Cincinnati to the
mid 70s south of Bowling Green.
.Long Term (Saturday night through Thursday)...
Updated at 306 AM EDT Mar 30 2012
Looks like the rest of the weekend will generally be dry as ridging
develops to our west and pushes east. The front will be to our south
on Saturday, and should hang up just south of the KY/TN border
Saturday night, keeping any precip south of our region. By Sunday
though, upper-level ridging will start to slide in from the west as
surface low pressure develops over the Central Plains. Removed POPs
on Sunday even though we`ll be under a northwest flow. Think the
ridge will move in fast enough to help suppress any convection, or
divert it to the north as a backdoor cold front associated with a
northeastern CONUS low drops across the upper Ohio Valley. This
should stay to our northeast as the warm front from the Central
Plains` surface low stretches as far east as our CWA by Monday.
Thus, have kept the mention of a slight chance of convection in for
Monday, though think any storms would be attributed to warm frontal
location and not just scattered in nature. After a warm and
generally dry Sunday with temps in the mid 70s northeast to the low
80s southwest.
From Monday afternoon on, there are significant differences with the
approaching low pressure system as the GFS and GEM show a much
slower solution than the Euro. Even the last hours of the NAM hint
at the same thing the GFS/GEM do, and that`s cutting off an upper
low over the southern Plains as the Euro is much more progressive
with the cold front approach. Either way, Monday should at least be
warm and moist with the warm front pushing northward across the
region. Then scattered afternoon-evening convection should develop
in the warm sector ahead of the approaching surface low/cold front.
However, since the Euro appears as the outlier, will trend with the
GFS which really slow down the low/front and fills it in, most
likely bringing a longer event than previously anticipated. Thus,
will slowly increase POPs from Monday afternoon through at least
Tuesday evening. Even hang onto rain showers Wednesday over the
southern half of the CWA as the low slowly exits the area. Went
below guidance for highs Wed thinking more clouds/precip will be
around than previously thought. After a warm Monday (highs in the
lower 80s most everywhere), temps fall back to around 70 for highs
on Tuesday with ample clouds and precip around, and into the 60s for
highs for the same reason(s) on Wednesday.
From Wednesday night on, system moves to our east and more ridging
returns to the Lower Ohio Valley, keeping us dry through Thursday.
Temperatures will moderate somewhat on Thursday. Under mostly clear
skies and dry conditions, highs should still reach the upper 60s on
Thursday after a chilly start to the day with morning lows in the
low 40s, mainly over the east/northeast. Because of these temps this
far out, may need to think about frost conditions over the Bluegrass
Wed night as a result.
&&
.Aviation (18Z TAF Issuance)...
Updated at 105 PM EDT Mar 30 2012
Surface warm frontal boundary has now cleared all the terminals and
southwesterly flow is picking up across the region. Partly to
mostly sunny skies are expected through the early afternoon hours,
but a distinct Cu field is already developing in the warm sector,
south of the warm front. Can not completely rule out an isolated
thunderstorm or two across the region this afternoon, but feel that
the best convective potential will increase this afternoon to our
northwest along an approaching frontal boundary. Scattered-broken
line of storms will likely develop out ahead of this boundary and
head east-southeastward across the area this evening. Feel that the
best chances of convection at KSDF/KLEX will be between
30/23Z-31/06Z. Given the uncertainty in the timing, will keep
VCTS going in the TAFs for now. Further south at KBWG, storms may
not be an issue tonight as the line is expected to weaken due to the
loss of instability as it heads southward into KY. Will maintain a
VCTS group after 31/04Z. After cold frontal passage late tonight,
we`ll see winds kick around to the northwest and then eventually to
the northeast during the day on Saturday.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........MJ
Short Term.......JSD
Long Term........AL
Aviation.........MJ
AREA FORECAST DISCUSSION...UPDATED
NWS PADUCAH KY
1234 PM CDT FRI MAR 30 2012
.UPDATE...
ISSUED AT 1233 PM CDT FRI MAR 30 2012
REFINED THE TIMING AND INTENSITY OF THE POP/WEATHER GRIDS FOR THE REST
OF TODAY AND INTO TONIGHT. ADJUSTMENTS WERE ALSO MADE TO REFINE OTHER
SENSIBLE WEATHER ELEMENTS...SUCH AS TEMPERATURE...DEWPOINT...WIND...SKY
COVER AND RELATIVE HUMIDITY.
WITH THE MANDATORY LEVEL UPPER AIR ANALYSIS...THERE WAS A MAXIMUM
OF HIGHER THETA-E AIR OVER SOUTHEAST OK...NORTHERN AR...AND
SOUTHEAST MISSOURI THIS MORNING...WITH A SECONDARY AREA OVER
NORTHERN AND NORTHEAST ILLINOIS. THE BEST LOW LEVEL MOISTURE WAS OVER
WEST KENTUCKY...SOUTHEAST ILLINOIS AND SOUTHWEST INDIANA.
THE 12KM NAM-WRF AND 3KM HRRR NUMERICAL MODEL
MASS/INSTABILITY/RADAR REFLECTIVITY FIELDS SUGGEST THAT THE
NORTHERN INDIANA CONVECTION AND NEWLY MINTED CENTRAL KENTUCKY CONVECTION
SHOULD GRADUALLY BUILD WESTWARD WITH TIME. THE 0-3/3-6KM NAM-WRF BULK
SHEAR REMAINS LOW /15-25 KNOTS/...SO SIGNIFICANT STORM
ORGANIZATION MAY NOT BE IN THE CARDS FOR THE AREA. HOWEVER...SHARP
LAPSE RATES AND DECENT CAPE/DOWNDRAFT CAPE SUGGEST THE POTENTIAL
THAT GOOD UPDRAFTS WILL WARRANT THE MENTION OF AT LEAST SMALL HAIL
AND GUSTY WINDS IN THE GRIDDED FORECAST THIS AFTERNOON AND INTO
THE EARLY EVENING HOURS. AT THIS TIME...FOCUSED THIS MENTION OF
HAIL/WIND IN THE SCATTERED THUNDERSTORM COVERAGE AREA.
THE NAM-WRF/GFS/RUC APPEARED TO INITIALIZE BETTER WITH INSTABILITY
/LIFTED INDEXES/ AND PRECIPITABLE WATER FROM THE GOES SOUNDER
IMAGERY VERSUS THE REST OF THE MODEL GUIDANCE THIS MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 1233 PM CDT FRI MAR 30 2012
IN LINE WITH THE MIDNIGHT SHIFT ADJUSTMENT FOR POPS/WEATHER
TONIGHT INTO SATURDAY...ADJUSTED AND SLIGHTLY INCREASED RAIN
CHANCES MAINLY OVER SOUTHEAST MISSOURI. GIVEN THE STRONGER DRY AIR
ADVECTION AHEAD OF THE FRONTAL BOUNDARY ON SATURDAY...KEPT RAIN
CHANCES OUT OF A VAST MAJORITY OF SOUTHERN ILLINOIS AND WEST
KENTUCKY AND ALL OF SOUTHWEST INDIANA.
RIDGING ON SUNDAY STILL REMAINS DOMINANT...SO LOW TO MIDDLE 80S
AND LIMITED CLOUD COVER REMAIN ON TARGET IN THE FORECAST.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 332 AM CDT FRI MAR 30 2012
HIGH PRESSURE AT THE SURFACE AND ALOFT WILL KEEP THE REGION DRY
SUNDAY AND SUNDAY NIGHT. BEYOND THAT MODELS NOT IN THE BEST
AGREEMENT IN THE WAY THEY HANDLE THE STORM SYSTEM TO AFFECT THE
AREA BEGINNING EARLY NEXT WEEK.
AS THE NEXT STORM SYSTEM MOVES OUT OF THE PLAINS...PRECIP CHANCES
MAKE THEIR WAY BACK INTO THE FORECAST ON MONDAY. HARD TO SAY HOW
MUCH COVERAGE THERE WILL BE ON MONDAY. MODELS SHOW DECENT RIDGING
ALOFT DIRECTLY OVER OUR CWA...BUT ALSO SHOW A SFC TROF AND WARM
FRONT OVER THE NORTHEAST SECTIONS ASSOCIATED WITH THE APPROACHING
STORM SYSTEM.
SHOWER AND THUNDERSTORM CHANCES APPEAR TO BE GREATEST MONDAY NIGHT
AND TUESDAY AS THE AFOREMENTIONED SYSTEM ACTUALLY MOVES ACROSS THE
AREA. NOT NEARLY AS CONFIDENT FOR PRECIP CHANCES TUESDAY NIGHT AND
WEDNESDAY. DURING THOSE PERIODS THE ECMWF IS MORE PROGRESSIVE AND
SHOWS HIGH PRESSURE OVERSPREADING THE AREA IN THE WAKE OF THE STORM
SYSTEM WHILE THE GFS WINDS UP THE UPPER LOW ASSOCIATED WITH THIS
SYSTEM AND MOVES IT SLOWLY ACROSS THE SOUTHERN SECTIONS OF THE CWA
DURING THE SAME PERIOD. DECIDED TO GO WITH SOMEWHAT OF A BLEND BUT
WITH A LEAN TOWARD THE GFS SOLUTION.
IN THE WAKE OF THIS SYSTEM SURFACE HIGH PRESSURE OVERSPREADING THE
AREA WILL KEEP THINGS DRY WITH TEMPERATURES CLOSER TO NORMAL FOR
THIS TIME OF YEAR.
BETWEEN A STORM SYSTEM DEVELOPING OVER THE PLAINS AND THE DEPARTING
SURFACE HIGH...SOUTHERLY FLOW WILL ADVECT ENOUGH MOISTURE BACK INTO
REGION TO WARRANT SHOWER AND THUNDERSTORM CHANCES ON MONDAY AND
MONDAY NIGHT. A FEW SHOWERS ARE POSSIBLE OVER THE NORTHEAST SECTIONS
OF THE CWA ON TUESDAY IN THE WRAP AROUND MOISTURE.
SURFACE HIGH PRESSURE IN THE WAKE OF THE FRONT AND WEAK RIDGING
ALOFT SHOULD KEEP THE REGION DRY AND SLIGHTLY COOLER THROUGH THE END
OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 705 AM CDT FRI MAR 30 2012
VFR CONDITIONS WILL PREVAIL OVER THE NEXT 24 HOURS. SOUTH WINDS
WILL PICK UP THIS MORNING TO 10 TO 15 KNOTS...WITH GUSTS OF 15 TO
20 KNOTS AT TIMES. SCATTERED CUMULUS DEVELOPMENT IS EXPECTED BY
LATE MORNING INTO THE AFTERNOON. ISOLATED THUNDERSTORMS WILL
DEVELOP DURING THE MID TO LATE AFTERNOON AHEAD OF A SOUTHWARD
ADVANCING COLD FRONT...SO INCLUDED A CB MENTION IN THE TAFS. THE
STORMS SHOULD DIMINISH DURING THE EVENING AS WINDS SUBSIDE.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...SMITH
SHORT TERM...SMITH
LONG TERM....JP
AVIATION...RJP
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
425 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 /20Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDS ACROSS THE REGION AT 18Z BUT AN AREA OF RAIN ASSOC WITH
A LOW PRES AREA IS MOVG THRU NOVA AND SRN MD. AT THE PRESENT SPEED
THE RAIN WILL LIKELY MOVE ONTO EASTERN SHORE MD AROUND 19Z AND
THEN AFFECT SBY. TEMPO MVFR CIGS/VSBY PSBL WITH THIS PRECIP THRU
THE AFTN. A WARM FRONT WILL MOVE N FROM THE CAROLINAS THIS EVENING
AND TONIGHT. LOW CLOUDS AND -RA WILL DEVELOP IN ADVANCE OF THE
FRONT DURING THE OVERNIGHT HOURS. TIMING IS DIFFICULT BUT THINK
RAIN WILL LIKELY AFFECT NE NC AND SRN VA FROM AFTER MIDNIGHT TO
MID MORNING ON SAT. THE WARM FRONT WILL BE NORTH OF OUR CWA EARLY
SAT. THEN A COLD FRONT IS EXPECTED TO APPROACH SAT AFTN/EVENING.
THIS WILL BRING ANOTHER CHC OF RAIN/TSTMS. THE FRONT CLEARS THE
REGION EARLY SAT EVENING. HIGH PRES BUILDS INTO THE REGION SUN AND
MON WITH EXPECTED GOOD VFR CONDS.
&&
.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...JEF
MARINE...AJZ
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
336 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/...
LATEST NUMERICAL MODEL GUIDANCE IS SUGGESTING SOMEWHAT MORE OF AN
AMPLIFIED MID AND UPPER LEVEL PATTERN FOR THE MEDIUM RANGE PERIOD.
THIS WOULD ENHANCE NW FLOW OVER THE MID ATLANTIC AND NORTHEAST
SUNDAY NIGHT AND INTO MONDAY...WHICH LOCALLY WOULD ALLOW A WEAK
BACKDOOR FRONT TO DROP INTO THE FORECAST AREA. NO SIGNIFICANT WX
EXPECTED WITH THIS...BUT THE POTENTIAL EXISTS FOR A 20+ DEGREE
TEMP DIFFERENCE ACROSS THE RGN. TMPS 65-70 EASTERN SHORE TO U70S-
L80S W OF THE BAY (NOT OUT OF THE QSTN TO SEE OXB DROP INTO THE
50S BY LATE IN THE DAY AS THE FLOW TURNS E). TUESDAY SHOULD REMAIN
MILD AHEAD OF AN APRCHG COLD FRONT. POPS WERE INCREASED TO CHANCE
FOR TUESDAY AFTERNOON EVENING...BUT THIS FRONT COULD END UP BEING
SLOWER IF THE AFOREMENTIONED AMPLIFICATION OCCURS. TEMPERATURES
WILL BE LOWER BEHIND THE FRONT...BUT STILL ON THE WARM SIDE OF
SEASONAL AVERAGES (LOW/MID 70S).
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDS ACROSS THE REGION AT 18Z BUT AN AREA OF RAIN ASSOC WITH
A LOW PRES AREA IS MOVG THRU NOVA AND SRN MD. AT THE PRESENT SPEED
THE RAIN WILL LIKELY MOVE ONTO EASTERN SHORE MD AROUND 19Z AND
THEN AFFECT SBY. TEMPO MVFR CIGS/VSBY PSBL WITH THIS PRECIP THRU
THE AFTN. A WARM FRONT WILL MOVE N FROM THE CAROLINAS THIS EVENING
AND TONIGHT. LOW CLOUDS AND -RA WILL DEVELOP IN ADVANCE OF THE
FRONT DURING THE OVERNIGHT HOURS. TIMING IS DIFFICULT BUT THINK
RAIN WILL LIKELY AFFECT NE NC AND SRN VA FROM AFTER MIDNIGHT TO
MID MORNING ON SAT. THE WARM FRONT WILL BE NORTH OF OUR CWA EARLY
SAT. THEN A COLD FRONT IS EXPECTED TO APPROACH SAT AFTN/EVENING.
THIS WILL BRING ANOTHER CHC OF RAIN/TSTMS. THE FRONT CLEARS THE
REGION EARLY SAT EVENING. HIGH PRES BUILDS INTO THE REGION SUN AND
MON WITH EXPECTED GOOD VFR CONDS.
&&
.MARINE...
WINDS HAVE SUBSIDED A LITTLE AS A SFC HIGH MOVD OVER THE WTRS AND
IS CONTINUING EAST. THIS WILL CAUSE SOME OF THE WINDS TO SHFT
MORE SE THIS AFTN. SPDS SHOULD AVG 10-15 KTS DURING THE AFTN WITH
SOME ISOLD GUST TO 20 KT PSBL BY EARLY EVENING. A FRONTL BNDRY
OVER THE CAROLINAS WILL MOVE NORTH AS A WARM FRONT THIS AFTN AND
EVENING AND WILL PASS OVER THE WTRS TONIGHT. EXPECT SOME INCREASE
IN WND SPDS AS THE FRONT MOVES NORTH AND THERE IS A CHC OF MINIMAL
SCA BY TONIGHT.
LO PRES AND ASSOCIATED COLD FRNT CROSS THE MID ATLANTIC
SAT...WITH A GOOD CHANCE OF SCA CONDS OVER ALL WATERS (ESPECIALLY
LWR BAY) SAT EVNING/NGT FOLLOWING THE FROPA. WILL HOLD OFF ON A
4TH PERIOD ADVISORY ATTM DUE TO UNCERTAINTIES WITH THE TIMING AND
STRENGTH OF THE SURGE THIS FAR OUT IN TIME. ASIDE FROM LINGERING 5
FT SEAS ON SUN...SUB- SCA CONDS EXPECTED AS HI PRES BUILDS IN FROM
THE W. FOLLOWING ANOTHER COLD FROPA EARLY MON...HI PRES AND QUIET
WX RETURNS OVER THE WATERS LATE MON/TUE.
&&
.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...JEF
MARINE...JEF
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
309 PM EDT FRI MAR 30 2012
.SYNOPSIS...
LOW PRESSURE AND ITS ASSOCIATED COLD FRONT WILL PASS THROUGH THE
REGION TONIGHT INTO SATURDAY. HIGH PRESSURE WILL BUILD OVERHEAD
SATURDAY NIGHT BEFORE MOVING OFF THE COAST SUNDAY. ANOTHER COLD
FRONT WILL PASS THROUGH THE REGION SUNDAY NIGHT FOLLOWED BY HIGH
PRESSURE EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
WARM ADVECTION HAS LED TO PLENTY OF CLOUDS AND ALSO SOME SHOWERS
ACROSS THE CWA THIS AFTERNOON. HRRR AND WRF-ARW HAVE DONE A DECENT
JOB IN HANDLING THIS ACTIVITY...AND MOVE THE SHOWERS EAST OF THE
CHESAPEAKE BAY AREA THROUGH 20Z-21Z.
AFTER THEN...CLOUD COVER WILL HANG ON ALTHOUGH THERE MAY BE A
RELATIVE LULL IN SHOWERS FOR A FEW HOURS FOR THE REST OF THE
AFTERNOON /SAVE FOR AN ISOLATED SHOWER ACROSS THE HIGHLANDS/.
ADDITIONAL ACTIVITY WILL DEVELOP ACROSS OHIO/WESTERN PA/WEST
VIRGINIA...AND WILL MOVE EAST THIS EVENING. ISENTROPIC LIFT IS ALSO
FORECAST TO STRENGTHEN ESPECIALLY ACROSS THE NORTHERN PORTION OF
THE CWA AS A WARM FRONT APPROACHES FROM THE SOUTH AND LOW PRESSURE
APPROACHES FROM THE WEST.
HAVE HIGHEST POPS /LIKELY TO CATEGORICAL/ ACROSS NORTHERN AND
WESTERN PORTIONS OF THE CWA TONIGHT WITHIN THE BEST LIFT...TAPERING
TO CHANCE POPS ACROSS THE SOUTHERN PORTION OF THE CWA. THIS LEANS
TOWARD POPS FROM THE SREFS.
HAVE ALSO INCLUDED ISOLATED THUNDERSTORMS ACROSS THE WESTERN PORTION
OF THE CWA FOR ANY ONGOING CONVECTION TO THE WEST MAKING IT INTO THE
CWA. WHILE THE ENVIRONMENT WILL BE LESS UNSTABLE THAN AREAS TO THE
WEST...NAM KEEPS SOME ELEVATED INSTABILITY ACROSS THE CWA.
LOW PRESSURE /AND ASSOCIATED FRONT/ MOVES ACROSS THE CWA EARLY
SATURDAY MORNING. UNTIL IT MOVES OFF THE COAST...WILL KEEP POPS
ACROSS THE CWA ESPECIALLY NEAR THE BAY. MUCH OF THE AFTERNOON SHOULD
DRY OUT...HOWEVER CLEARING WILL LAG A BIT AND CLOUDS MAY NOT BREAK
UNTIL EVENING.
TEMPERATURE GUIDANCE WAS GENERALLY SIMILAR AND FOLLOWED TONIGHT.
GUIDANCE WAS DIFFERENT BY UP TO 10 DEG F FOR MAX T ON SATURDAY.
FOLLOWED THE MET MOS WHICH KEEPS CLOUDS THROUGH THE AFTERNOON VERSUS
THE MAV MOS WHICH BREAKS CLOUDS SOONER.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE WILL BUILD OVERHEAD SATURDAY NIGHT BEHIND A COLD
FRONT...RESULTING IN DRY AND SEASONABLY CHILLY CONDITIONS. MIN TEMPS
WILL RANGE FROM THE MID 30S ACROSS NORTHERN MARYLAND TO THE LOWER
AND MIDDLE 40S IN LOWER SOUTHERN MARYLAND INTO THE VIRGINIA
PIEDMONT. PATCHY FROST IS POSSIBLE MAINLY IN RURAL AREAS AND
SHELTERED VALLEYS LATE SATURDAY NIGHT ACROSS NORTHERN MARYLAND INTO
THE EASTERN PANHANDLE OF WEST VIRGINIA.
SURFACE HIGH PRESSURE WILL MOVE OFF THE COAST SUNDAY ALLOWING FOR
RETURN FLOW TO DEVELOP. THE RETURN FLOW WILL USHER IN MILD
CONDITIONS WITH MAX TEMPS RANGING FROM THE MID 60S ACROSS
NORTHEASTERN MARYLAND TO THE MIDDLE AND UPPER 70S ACROSS CENTRAL
VIRGINIA. A COLD FRONT WILL APPROACH THE REGION LATE SUNDAY FROM THE
NORTH. THE FRONT SHOULD REMAIN FAR ENOUGH TO THE NORTH FOR DRY
CONDITIONS ALONG WITH SOME SUNSHINE ACROSS MOST AREAS. HOWEVER...A
COUPLE SHOWERS MAY REACH NORTHERN MARYLAND/EASTERN WEST VIRGINIA
LATER IN THE AFTERNOON.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
UPPER-LEVEL LOW PRESSURE WILL DEVELOP OFF THE NEW ENGLAND COAST
SUNDAY NIGHT INTO EARLY NEXT WEEK. THE COLD FRONT ASSOCIATED WITH
THIS SYSTEM WILL PASS THROUGH THE REGION SUNDAY NIGHT. SHOWERS ARE
POSSIBLE WITH THE FRONTAL PASSAGE.
HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT FOR MONDAY THROUGH
MONDAY NIGHT...BRINGING DRY AND SEASONABLE CONDITIONS.
HIGH PRESSURE WILL MOVE OFF THE COAST TUESDAY AND ANOTHER COLD FRONT
WILL PASS THROUGH THE AREA TUESDAY NIGHT INTO WEDNESDAY. SHOWERS AND
THUNDERSTORMS ARE POSSIBLE WITH THE FRONTAL PASSAGE. THE BEST CHANCE
FOR T-STORMS WILL LIKELY BE ACROSS THE WESTERN PORTION OF THE CWA
WHERE THERE WILL BE MORE INSTABILITY.
SURFACE HIGH PRESSURE WILL LIKELY BUILD OVERHEAD WHILE THE COLD
FRONT MOVES TO OUR SOUTH LATE IN THE WEEK. HOWEVER...THERE IS STILL
A HIGH DEGREE OF UNCERTAINTY TO THE EXACT POSITION OF THE FRONT
DURING THIS TIME. SHOULD THE FRONT BE A BIT FARTHER NORTH...THEN
UNSETTLED CONDITIONS ARE POSSIBLE.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
MID LEVEL CLOUD DECK WILL LOWER THIS EVENING WITH SOUTHEAST FLOW IN
PLACE AND LOW PRESSURE APPROACHING FROM THE WEST. GFS MOS/LAMP ARE
AGGRESSIVE IN BRINGING IN IFR/LIFR TO ALL TERMINALS
OVERNIGHT/SATURDAY MORNING. NAM MOS BRINGS IN IFR AT BWI/MTN AS WELL
BUT NOT THE OTHER TERMINALS. TAFS LEAN MORE TOWARD THIS SOLUTION.
BELIEVE WARM FRONT WILL MOVE NORTH TOWARD/PAST THE IAD-DCA TERMINALS
OVERNIGHT. BWI/MTN AND ALSO MRB TO THE NORTH OF THE BOUNDARY ARE
EXPECTED TO DETERIORATE INTO IFR WITH SHOWERS MOVING ACROSS
OVERNIGHT/EARLY SATURDAY. TO THE SOUTH OF THE BOUNDARY...HAVE
SIDED WITH MVFR WITH LOWER CONFIDENCE IN IFR. SREFS PROBS FOR IFR
SUPPORT THE IFR INCLUSION AT MRB/BWI/MTN AND NOT THE FURTHER SOUTH
TERMINALS. ALL RESTRICTIONS WILL IMPROVE BY MID-MORNING SATURDAY
AS WINDS SHIFT TO THE NORTHWEST WITH LOW PRESSURE MOVING OFF THE
COAST. DESPITE THIS...NAM MOS ACTUALLY KEEPS IFR AT BWI/MTN
HOWEVER BELIEVE THIS IS OVERDONE.
HIGH PRESSURE WILL BUILD OVER THE TERMINALS SATURDAY
NIGHT...BRINGING VFR CONDITIONS MOST OF THE TIME. PATCHY BR MAY
CAUSE VSBYS TO APPROACH MVFR LEVELS EARLY SUNDAY MORNING.
A SOUTHERLY FLOW WILL INCREASE SUNDAY AS HIGH PRESSURE MOVES
OFFSHORE. VFR CONDITIONS ARE EXPECTED. THE COLD FRONT WILL PASS
THROUGH SUNDAY NIGHT BEFORE HIGH PRESSURE BUILDS OVERHEAD EARLY NEXT
WEEK. VFR CONDITIONS ARE EXPECTED MOST OF THE TIME. ANOTHER COLD
FRONT WILL IMPACT THE TERMINALS DURING THE MIDDLE PORTION OF NEXT
WEEK.
&&
.MARINE...
SMALL CRAFT ADVISORY WILL REMAIN IN EFFECT FOR THIS EVENING. IT
LOOKS MARGINAL...BUT GUIDANCE SUGGESTS SOUTHEAST WINDS INCREASING
THIS EVENING ACROSS THE LOWER TIDAL POTOMAC/MD BAY AREA. HIGHER
PROBABILITY SMALL CRAFT ADVISORY LOOKS TO BE SATURDAY AFTERNOON AS
DEPARTING LOW PRESSURE MOVES OFF THE COAST AND WINDS TURN TO THE
NORTHWEST.
HIGH PRESSURE WILL BUILD OVER THE WATERS SATURDAY NIGHT.
NORTH-NORTHEAST WINDS AHEAD OF THE HIGH WILL GUST PAST SCA CRITERIA.
A SMALL CRAFT ADVISORY IS IN EFFECT FOR ALL OF THE WATERS SATURDAY
EVENING...AND FOR THE MIDDLE PORTION OF THE BAY AND LOWER TIDAL
POTOMAC RIVER OVERNIGHT. WINDS WILL DIMINISH TOWARD MORNING AS THE
HIGH BUILDS OVERHEAD.
HIGH PRESSURE WILL MOVE OFF THE COAST SUNDAY AND A SOUTHERLY RETURN
FLOW WILL INCREASE. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR
PORTIONS OF THE WATERS SUNDAY AFTERNOON. A COLD FRONT WILL PASS
THROUGH THE WATERS SUNDAY NIGHT AND HIGH PRESSURE WILL BUILD
OVERHEAD EARLY NEXT WEEK. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR
PORTIONS OF THE WATERS AHEAD OF THE COLD FRONT SUNDAY EVENING AND
AGAIN FOR BEHIND THE COLD FRONT SUNDAY NIGHT AND MONDAY.
HIGH PRESSURE WILL MOVE OFF THE COAST TUESDAY AND ANOTHER COLD FRONT
MAY IMPACT THE WATERS DURING THE MIDDLE PORTION OF NEXT WEEK. A
SMALL CRAFT ADVISORY MAY BE NEEDED FOR PORTIONS OF THE WATERS DURING
THE MIDDLE PORTION OF NEXT WEEK.
&&
.TIDES/COASTAL FLOODING...
WILL HAVE TO CONTINUE TO MONITOR WATER LEVELS FOR THE TONIGHT HIGH
TIDE CYCLE. FORTUNATELY...ASTRONOMICAL TIDES ARE RELATIVELY LOW
CONSIDERING THE LUNAR CYCLE. ANOMALIES NEAR 1 FT AT ANNAPOLIS
CAUSED A WATER LEVEL OF NEAR 2.2 FT MLLW DURING HIGH TIDE AROUND
NOON. ANOMALIES MAY GO UP A LITTLE MORE THIS EVENING...HOWEVER THE
EVENING HIGH TIDE IS ALSO THE LOWER OF THE TWO.
THEREFORE...CURRENT FORECAST IS FOR WATER LEVELS TO REMAIN JUST
UNDER MINOR TIDAL FLOODING THRESHOLDS. HOWEVER...IF ANOMALIES
INCREASE MORE/FASTER THEN SENSITIVE LOCATIONS SUCH AS ANNAPOLIS
COULD REACH MINOR TIDAL FLOODING THRESHOLDS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO MIDNIGHT EDT
TONIGHT FOR ANZ531>534-537>543.
SMALL CRAFT ADVISORY FROM 1 PM TO 10 PM EDT SATURDAY FOR
ANZ530-531-535-536-538-539.
SMALL CRAFT ADVISORY FROM 1 PM SATURDAY TO 6 AM EDT SUNDAY FOR
ANZ532>534-537-540>543.
&&
$$
SYNOPSIS...BJL/BPP
NEAR TERM...BPP
SHORT TERM...BJL
LONG TERM...BJL
AVIATION...BJL/BPP
MARINE...BJL/BPP
TIDES/COASTAL FLOODING...BPP
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
131 PM EDT FRI MAR 30 2012
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 423 AM EDT FRI MAR 30 2012
BROAD AREA OF SHOWERS STRETCHING FROM THE ARROWHEAD OF MN THROUGH
WRN UPPER MI...WRN TWO THIRDS OF WI AND INTO ERN IOWA AT 07Z. OVER
THE ARROWHEAD OF MN AND INTO WRN UPPER MI...SHOWERS HAVE BEEN MAINLY
IN THE FORM OF SNOW. RECENT WEBCAM IMAGES IN IRONWOOD SHOW A DUSTING
OF SNOW ON THE GROUND OVER THE LAST HOUR OR SO. FARTHER SOUTH AND
WEST...STARTING TO SEE A TRANSITION TO RAIN AS THE NOSE OF WARM
AIR AND DRY AIR ALOFT ARE STARTING TO TURN THE PCPN BACK TO RAIN
OVER NW WI. THIS IS ALL RAIN THROUGH THE REST OF WI AND INTO
IOWA...WHERE CONVECTION DEVELOPED DURING THE EVENING AND HAS SPREAD
NE. THE PCPN IS ASSOCIATED WITH A SHORTWAVE MOVING THROUGH THE
CNTRL/NRN PLAINS STATES...WHILE A SFC LOW IS TRACKING THROUGH NRN
MO AND SRN IOWA.
PCPN FOR THIS MORNING IS THE MAIN FEATURE OF CONCERN FOR THE SHORT
TERM FORECAST. THE NRN PART OF THE PCPN AREA IS THE INITIAL AREA OF
CONCERN. THIS SHOULD CONTINUE TO THE E OVER THE NEXT SEVERAL
HOURS...BUT WITH THE MID-LOW LVL DRY AIR IN PLACE...EXPECT THIS TO
EAT AWAY AT THE PCPN AS IT MOVES OUT OF WRN UPPER MI. THIS
DIMINISHING TREND WILL ALSO BE DUE TO THE FORCING FOCUSING FARTHER
S OVER CNTRL WI...ASSOCIATED WITH THE RIGHT REAR OF THE UPPER JET
AND H850-700 WAA. THIS REFOCUSING HAS BEEN SEEN ON RADAR OVER THE
LAST HOUR...WITH SHOWERS BECOMING MORE WIDESPREAD OVER CNTRL/SRN
WI.
THE QUESTION WITH THE SRN AREA OF PCPN WILL BE HOW FAR N IT
WILL TRACK. MODELS CONSISTENT ON THE H925-850 WAA REMAINING OVER THE
SE HALF OF WI AND THE ONLY THING REALLY GOING FOR SOME PCPN FARTHER
TO THE N IS SOME H850-700 FGEN OVER THE SCNTRL. LOOKING AT FGEN
CROSS-SECTIONS OVER THE CWA...THAT AREA IS UNDER THE ASCENDING
BRANCH OF FGEN. OTHERWISE...IT SEEMS LIKE MUCH OF REST OF THE AREA
WILL BE ON THE DESCENDING BRANCH OF THE FGEN. THIS SUPPORTS A
DIMINISHING TREND THE MODELS SHOW WITH THE NRN PCPN AREA AND
THINK THAT LLVL DRY ERLY FLOW WILL COMBINE TO LIMIT THE PCPN FROM
GOING TOO FAR EAST OF A LINE FROM KMQT/KESC. THUS...HAVE DIMINISHED
POPS OVER THE E TO JUST SLIGHTS. FOR THE STRONGER PCPN AREA...00Z
MODEL RUNS...ALONG WITH THE HOURLY RUC RUNS...ALL SHOW THIS STRONGER
PCPN JUST BRUSHING THE SCNTRL CWA AND CORRELATES WELL WITH THE FGEN.
AS FOR PCPN AMNTS...THE DIMINISHING TREND OVER THE N SHOULD KEEP
LIQUID AMNTS LIGHT. ALONG THE WI BORDER...COULD SEE AMNTS IN THE
0.1 TO 0.2 RANGE...WITH THE HIGHEST AMNTS NEAR THE CITY OF
MENOMINEE. 29/21Z SREF SUPPORTS THAT SOLN AND SHOWING BEST CHANCES
OF 0.1IN ALONG THE WI BORDER AND MAINLY NEAR MENOMINEE...SO FEEL
THAT IS THE WAY TO GO. RUC/NAM SOUNDINGS SHOW THE PCPN FALLING AS
SNOW FOR THE FIRST HOUR OR TWO OF PCPN...BUT THEN START
TRANSITIONING TO A -RA/DZ THROUGH THE MORNING HOURS FROM W TO E.
THIS IS DUE TO DRIER AIR ALOFT MOVING INTO THE AREA FROM W TO E
AFTER 12Z. OVER THE FAR WEST...WARMER H875 TEMPS WILL PRODUCE A
QUICKER CHANGE OVER TO RAIN OVER GOGEBIC COUNTY...PROBABLY TOWARDS
DAYBREAK. FORTUNATELY...LLVL TEMPERATURES SHOULD BE WARMING AT THAT
TIME AND LIMIT POTENTIAL FOR FREEZING ON THE SFC. PREVIOUS SHIFT HAD
A GOOD HANDLE ON THIS AND WILL FOLLOW THAT TRANSITION. THUS...SNOW
AMNTS SHOULDN/T BE ANYTHING TOO SUBSTANTIAL. HAVE AROUND AN INCH
FOR THE WI BORDER AREA AND TAPER IT OFF TO A DUSTING OVER THE N. IF
STRONGER PCPN MAKES IT TO MENOMINEE...COULD SEE A HEAVIER BURST OF
SNOW TOWARDS THE MORNING COMMUTE THAT COULD QUICKLY PRODUCE AN INCH
OR TWO OF SNOW. WITH THIS BEING THE FIRST MEASUREABLE SNOW FOR A
WHILE AND IT OCCURRING DURING THE MORNING COMMUTE...WITH CONTINUE
THE SPS FOR THE SCNTRL THROUGH THE MORNING HOURS.
FOR THE REST OF THE DAY...EXPECT THE PCPN TO QUICKLY TRANSITION TO
THE SE WITH THE BETTER LLVL WAA AND END UP PRODUCING A CLOUDY DAY.
HAVE LINGERING SOME LOW POPS FOR SOME LIGHT RAIN SHOWERS AND
DRIZZLE THROUGH THE EARLY AFTN...BUT THEN EXPECT THAT TO COME TO AN
END.
TONIGHT...SFC HIGH PRESSURE RIDGE MOVES BACK INTO THE AREA...BUT
LLVL MOISTURE BELOW H900 REMAINS. THINK THE LOW CLOUDS WILL PERSIST
AND BE THE THICKEST OVER THE CNTRL CWA...WHERE THE LLVL MOISTURE
REMAINS IN PLACE AND H925 TEMPS OF -3C OVER LK MI WILL HELP WITH
SOME LK INSTABILITY. IN ADDITION...LIGHT SE UPSLOPE FLOW WILL HELP
KEEP THE CLOUDS IN PLACE. FARTHER E...DRY ERLY FLOW FROM THE SFC
RIDGE WILL KEEP SKIES MORE PARTLY CLOUDY TOWARDS LUCE COUNTY. OVER
THE FAR W...COULD BE SOME DOWNSLOPE BREAKS IN THE CLOUDS OVER WRN
GOGEBIC/ONTONAGON COUNTIES. WITH THIS LLVL MOISTURE AND UPSLOPE
FLOW...COULD BE SOME -DZ OR LOW CLOUD FOG FROM KMQT/KSAW TO KIMT BUT
OVERALL POTENTIAL SEEMS LIMITED TO MENTION AT THIS POINT.
SATURDAY...SFC HIGH SLIDES E AS STRONG UPPER JET ROUNDING
THE AMPLIFYING UPPER RIDGE MOVES INTO SRN MANITOBA/ONTARIO.
SHORTWAVE ASSOCIATED WITH THIS JET WILL DEVELOP A SFC LOW IN THE
SAME AREA ON SAT. EXPECT LLVL MOISTURE TO BE LINGERING INTO THE
MORNING. DIURNAL MIXING AND WINDS BACKING TO THE S SHOULD
ALLOW FOR THE LOW CLOUDS TO BREAK UP TOWARDS MID DAY...WITH THEM
HANGING ON THE LONGEST OVER THE UPSLOPE CNTRL CWA.
AS THE LOW CLOUDS DIMINISH...MID CLOUDS WILL BEGIN MOVING IN
AHEAD OF THE SHORTWAVE AND UNDER THE INCREASING WAA...ESPECIALLY
OVER THE NW HALF OF THE CWA. MOISTURE IS MARGINAL...AND BEST FORCING
FROM THE SHORTWAVE IS IN CANADA...SO DON/T THINK THE CHANCES OF PCPN
DEVELOPING IS TOO HIGH BUT WILL CONTINUE TO MENTION SLIGHTS. DID
BRING THE POPS A LITTLE FARTHER S TO COVER THE KEWEENAW PENINSULA.
LOWERED TD VALUES SOME OVER THE FAR ERN CWA...WHERE THERE WILL BE
GREATER MIXING WITH LESS CLOUDS AND DRIER AIR CLOSER TO THE SFC
RIDGE. DIDN/T GO AS LOW AS NAM/ECMWF ML DEWPOINT VALUES...IN THE
MID TEENS...BUT LOWERED INTO THE LOWER 20S. WARMEST HIGHS WILL
BE OUT WEST...WHERE THE SRLY FLOW WILL PULL H875 TOWARDS 10C.
WON/T MIX QUITE THAT HIGH...BUT SHOULD MIX BETWEEN THERE AND
H900...WHICH WOULD PRODUCE HIGHS IN THE UPPER 50S TO NEAR 60. IF IT
COULD MIX SLIGHTLY HIGHER...WOULD EASILY HAVE TEMPS IN THE MID 60S.
FARTHER E...THE LINGERING LOW CLOUDS IN THE MORNING WILL LIMIT THE
WARM UP...ALONG WITH COOLER H900 TEMPS LINGERING UNDER THE INITIAL
ESE FLOW. TEMPS OVER THE CNTRL/EAST WILL DEPEND ON HOW QUICKLY THE
WARMER AIR ALOFT ARRIVES IN THE AFTN...BUT THE BREAKS TOWARDS MID
DAY WILL PRODUCE HIGHS IN THE MID 40S TO LOWER 50S.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 423 AM EDT FRI MAR 30 2012
GFS SHOWS A RIDGE BUILDING INTO THE AREA ON SUNDAY WITH A SHORTWAVE
PASSING BY TO THE NORTH SAT NIGHT. A WARM FRONT COMES THROUGH ON
SUNDAY NIGHT WITH TROUGHING MOVING IN FOR MONDAY. THIS WILL CONTINUE
TO BE QUITE ACTIVE THIS PERIOD WITH PCPN CHANCES OVER THE NORTH AND
EAST SAT NIGHT AND THEN OVER THE AREA FOR SUNDAY NIGHT AND MONDAY.
WENT WITH CHANCE POPS FOR THESE TIME PERIODS. OVERALL...DID NOT MAKE
TOO MANY CHANGES TO THE GOING FORECAST FOR TEMPERATURES OR WEATHER.
IN THE EXTENDED...ABOVE NORMAL TEMPERATURES CONTINUE...BUT
CONFIDENCE IS FAIRLY LOW AS POSITION OF FRONTS COULD BE TRICKY FOR
HIGH TEMPERATURES. IF THE WARM FRONT AND WARM SECTOR PART OF THE
STORM MAKES IT THROUGH THE AREA...COULD BE VERY WARM. RIGHT
NOW...GFS AND ECMWF TAKE SFC LOW PRESSURE TO THE SOUTH AND KEEP THE
AREA MORE TOWARDS THE COLDER PART OF THE STORM. CHANCE POPS CONTINUE
MONDAY INTO TUESDAY BEFORE DRY WEATHER MOVES IN FOR TUE NIGHT AND
LASTS INTO THURSDAY AS TROUGHING CONTINUES TO THE EAST OF THE AREA
WITH UPPER LEVEL RIDGING TO THE WEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 130 PM EDT FRI MAR 30 2012
LOW LEVEL MOISTURE STREAMING OVER THE AREA THIS AFTERNOON SHOULD
LEAD TO SOME SHOWERS AT SAW AND BR AT IWD. WITH THE SE FLOW...CMX IS
NOT EXPERIENCING AS LOW OF CIGS/VIS DUE TO DOWNSLOPING WINDS OFF THE
HURON MOUNTAINS.
TONIGHT...LOW LEVEL MOISTURE WILL LIKELY REMAIN TONIGHT AND LEAD TO
LOWERING MVFR CIGS AT ALL THREE SITES. KSAW WILL HAVE THE BEST
CHANCE OF SEEING IFR CIGS WITH UPSLOPE SERLY FLOW. KCMX WILL NOT SEE
AS LOW OF CIGS DUE TO CONTINUED DOWNSLOPING FLOW OFF THE HURON
MOUNTAINS. KIWD WILL SEE SOME DOWNSLOPING WITH THAT WIND DIRECTION
SO HAVE CIGS HIGHER THAN SAW BUT STILL IN THE MVFR CATEGORY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 423 AM EDT FRI MAR 30 2012
LAKE SUPERIOR WILL BE BETWEEN HIGH PRESSURE IN ONTARIO AND A LOW
PRESSURE SYSTEM MOVING THROUGH NRN ILLINOIS. THIS WILL PRODUCE SE
WINDS UP TO 25KTS TODAY...BEFORE DIMINISHING THIS AFTN/EVENING...AS
A HIGH PRESSURE RIDGE REESTABLISHES ITSELF OVER LAKE SUPERIOR.
THIS SHOULD KEEP WINDS BELOW 25KTS THROUGH THE WEEKEND AS
ANOTHER LOW MOVES THROUGH MANITOBA/ONTARIO ON SATURDAY. LOW
PRESSURE DEVELOPING OVER THE NORTHERN/CENTRAL PLAINS ON SUNDAY WILL
APPROACH THE GREAT LAKES FOR THE BEGINNING OF NEXT WEEK. THIS LOW
WILL WEAKEN AS IT MOVES ACROSS THE GREAT LAKES ON MONDAY AND
TUESDAY AND WINDS SHOULD STAY BELOW 20KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...07
AVIATION...TITUS
MARINE...SRF
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1230 PM CDT FRI MAR 30 2012
.UPDATE...
ISSUED AT 910 AM CDT FRI MAR 30 2012
HAVE UPDATED FORECAST THIS MORNING TO BOOST TEMPERATURES A FEW
DEGREES ACROSS THE SOUTHERN PORTION OF THE CWA...AHEAD OF THE
FRONT. 850MB TEMPERATURES WOULD SUGGEST HIGHS IN THE LOWER 80S.
STRIPPED POPS FROM THE FORECAST FOR THIS MORNING AND CONCENTRATED
SCATTERED POPS ALONG AND SOUTH OF I-44 IN MISSOURI AND I-70 IN
ILLINOIS FOR THE AFTERNOON HOURS. LATEST HRRR SUGGESTS CONVECTIVE
INITIATION WILL OCCUR BETWEEN 18 AND 20Z ALONG THE FRONT.
CVKING
&&
.SHORT TERM...
ISSUED AT 325 AM CDT FRI MAR 30 2012
(TODAY)
SURFACE LOW TO CONTINUE TRACKING TO THE EAST THIS MORNING ACROSS
NORTHERN MISSOURI...THEN INTO WESTERN OHIO BY EARLY THIS EVENING.
ASSOCIATED COLD FRONT TO SLIDE THROUGH FORECAST AREA TODAY...MOVING
INTO NORTHEAST MO...WEST CENTRAL IL JUST AFTER DAYBREAK...THEN INTO
THE ST. LOUIS METRO AREA BY MIDDAY. AS FOR CHANCES OF SHOWERS AND
THUNDERSTORMS WITH THIS BOUNDARY...DESPITE CAPES BETWEEN 500 AND
2000 J/KG...CONVERGENCE ALONG BOUNDARY CONTINUES TO LOOK WEAK WITH
BEST LIFT FURTHER TO THE EAST ALONG THE FRONT...CLOSER TO THE
SURFACE LOW. SO BACKED OFF ON POPS A BIT...WITH BEST CHANCES ALONG
AND EAST OF MISSISSIPPI RIVER TODAY. COULD SEE SOME STRONG STORMS BY
THIS AFTERNOON...MAINLY OVER SOUTHERN IL.
AS FOR CLOUDS...SEEING PLENTY OF RESIDUAL MID AND HIGH CLOUDS FROM
ACTIVITY THAT FIRED UP OVERNIGHT...BUT THIS SHOULD THIN A BIT
ALLOWING FOR A MIX OF SUN AND CLOUDS TODAY. SO TEMPS TO WARM UP INTO
THE LOW 70S FAR NORTH TO THE UPPER 70S ALONG AND SOUTH OF I-70.
WINDS TO PICKUP FROM THE SOUTH TO SOUTHWEST THIS MORNING AHEAD OF
FRONT...THEN SWITCH TO THE NORTHWEST WITH THE PASSAGE OF THE COLD
FRONT.
BYRD
&&
.LONG TERM...
ISSUED AT 320 AM CDT FRI MAR 30 2012
(TONIGHT THROUGH THURSDAY)
CDFNT IS EXPECTED TO STALL OVER SRN MO AND FAR SRN IL TONIGHT. A FEW
STRAGGLER SHRA/TSRA MAY EXIST INVOF FRONT EARLY THIS EVENING FOR
SECTIONS OF SERN MO AND SRN IL BUT SHOULD EXIT OR DISSIPATE BY 9PM.
UPPER LEVEL DISTURBANCES...IN THE MEANTIME...WILL CONTINUE TO RIPPLE
THRU THE AREA LATER TONIGHT AND SATURDAY BUT ARE REALLY ONLY
EXPECTED TO HAVE MUCH IF ANY IMPACT NEAR THE FRONTAL ZONE IN THE FAR
SRN FA LATE TONIGHT AND EXPANDING A BIT NWD BY SATURDAY AFTERNOON AS
FRONT BEGINS TO BUCKLE NWD AS A WRMFNT. FOR POPS TONIGHT AND
SATURDAY...A LOT OF CLOSE CALLS BUT NOT A GOOD FEEL FOR ANYTHING
CONSIDERING FRONTAL BOUNDARY SHOULD BE LARGELY IF NOT ENTIRELY OUT
OF THE FA DURING THESE TIMES...SO JUST WENT WITH SLIGHT CHCS.
WRMFNT WILL MAKE ITS BIG PUSH THRU THE FA SATURDAY NIGHT. MUCH OF
THE BETTER LIFT WITH THE LO LEVEL JET SHOULD BE TO THE N OF THE FA
BUT WHAT DOES DEVELOP WILL TRY TO TURN SE TOWARDS THE FA AND HAVE
ACCOUNTED FOR WITH SOME LO-END POPS.
BIG STORY FOR SUNDAY AND MONDAY WILL BE WHAT SHOULD BE THE WARMEST
DAYS OF THIS ABNORMALLY WARM SEASON. SUNDAY WILL FEATURE A
MODERATELY STRONG S-SW FLOW WITH ABUNDANT SUNSHINE. MIXING HEIGHTS
SHOULD REACH H850 AND H850 TEMPS OF 16-18C STRONGLY POINT TOWARDS
MID-UPR 80S FOR MAX TEMPS WITH A REASONABLE CHC OF TOUCHING 90F.
FEEL COMFORTABLE GOING 2-3F ABOVE THE HIGHEST MOS ON THIS DAY.
MONDAY WILL FEATURE A BIT MORE UNCERTAINTY BUT A STRONG ENOUGH
SIGNAL WITH WHAT SHOULD BE A FURTHER DELAY TO THE UPPER LEVEL SYSTEM
TO THE W TO ALSO GO NEAR PERSISTENCE.
SPEAKING OF THE DELAY TO THE UPPER LEVEL SYSTEM ON MONDAY...MODELS
CONTINUE TO SHOVE BACK THE BETTER CHCS FOR RAIN EARLY NEXT WEEK TO
THE MIDDLE PART OF THE WEEK...WITH BOTH ECMWF AND GFS CLOSING A LO
OFF AND AT THIS POINT SHOW A LARGE DEAL OF UNCERTAINTY ON WHERE TO
TRACK IT AND HOW FAST TO DO IT. IT IS WELL WITHIN THE REALM OF
POSSIBILITY THAT NO RAIN WILL RESULT FROM THIS IF THE UPPER LO
TRACKS TOO FAR S OR IS DELAYED TOO MUCH BUT LEANING TOWARDS THE GFS
SOLN SINCE IT WAS THE FIRST TO SHOW THE CUTOFF POTENTIAL AND HAS HAD
BETTER RUN-TO-RUN CONSISTENCY. THE GFS SUGGESTS AN EXTENDED PERIOD
OF RAIN FROM TUESDAY THRU WEDNESDAY AND HAVE CHC CATEGORY POPS FOR
THIS PERIOD. TEMPS APPEAR THEY WILL EDGE CLOSER TO SEASONAL
AVERAGES...ESPECIALLY IF RAIN MATERIALIZES...BUT WITH ANOTHER BIG
RIDGE READY TO BOUNCE BACK FOR LATE WEEK...TEMPS SHOULD HAVE A
FAIRLY EASY TIME STAYING ABOVE AVERAGE.
TES
&&
.AVIATION...
ISSUED AT 1226 PM CDT FRI MAR 30 2012
WEAK COLD FRONT WILL CONTINUE TO SLIDE SOUTHEAST THIS AFTERNOON
ACROSS THE AREA WITH SHOWERS AND STORMS DEVELOPING ACROSS
SOUTHEAST MISSOURI AND SOUTHWEST ILLINOIS. TOO CLOSE TO NOT HAVE
AT LEAST A VCSH/CB IN THE ST. LOUIS METRO TAFS. OTHERWISE...VFR
CONDITIONS EXPECTED UNTIL LATER TONIGHT WHEN LIGHT WINDS AND
SUFFICIENT LOW LEVEL MOISTURE SHOULD RESULT IN MVFR FOG.
SPECIFICS FOR KSTL...
VFR CONDITIONS THIS AFTERNOON WITH JUST A SLIGHT CHANCE OF A
SHOWER DEVELOPING OVER THE TERMINAL. COLD FRONT WILL SLIDE
SOUTHEAST EARLY ON...WITH WINDS BECOMING NORTHWEST. WINDS BECOME
LIGHT TONIGHT AND THIS COULD RESULT IN SOME MVFR FOG. WINDS BECOME
EAST ON SATURDAY.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
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.
&&
$$
CHERMOK
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1155 AM CDT FRI MAR 30 2012
.AVIATION...18Z KGRI TAF. VFR CONDITIONS ARE EXPECTED THROUGHOUT
THE ENTIRE TAF PERIOD. AS AN UPPER LEVEL RIDGE BUILDS INTO THE
REGION...THE MAIN CONCERN FOR THE TAF PERIOD WILL BE INCREASING
WINDS TODAY AS BOUNDARY LAYER MIXING OCCURS. SUSTAINED WINDS NEAR
12 KTS IS CERTAINLY POSSIBLE THROUGHOUT THE AFTERNOON HOURS. A FEW
MID TO HIGH CLOUDS ARE EXPECTED DURING THE TAF PERIOD AS THE UPPER
LEVEL JET WRAPS AROUND THE TOP OF THE RIDGE. WINDS WILL BECOME
LIGHT THIS EVENING BEFORE INCREASING AGAIN SATURDAY MORNING FROM
THE SOUTHWEST.
&&
PREV DISCUSSION... /ISSUED 328 AM CDT FRI MAR 30 2012/
SHORT TERM...TODAY THROUGH SUNDAY NIGHT. A FAIRLY PROGRESSIVE
ZONAL FLOW PATTERN WAS IN PLACE ACROSS THE CENTRAL PLAINS WITH ONE
SHORTWAVE TRANSLATING TO OUR EAST...EAST OF THE MISSOURI
RIVER...WITH ANOTHER UPSTREAM SHORTWAVE TROUGH LOCATED IN EASTERN
WY/CO. CURRENTLY AT THE SURFACE...LOW PRESSURE WAS CENTERED IN
NORTHWEST MISSOURI WITH COOL FRONTAL BOUNDARY STRETCHING THROUGH
CENTRAL KANSAS. SFC DPS REMAIN HIGH ALONG THE MISSOURI RIVER INTO
NORTH CENTRAL AND EASTERN KANSAS WITH READINGS IN THE 50S TO
AROUND 60F AND HRRR SUGGESTS SOME FOG DEVELOPMENT ACROSS NORTHEAST
KANSAS INTO SOUTHEAST NEBRASKA OR JUST ON THE PERIPHERY OF OUR
SOUTHEAST CWA. OBSERVATION AT 08Z AT BELOIT SHOWED VSBY DROPPED TO
ONE QUARTER MILE AND IF TRENDS CONTINUE FOG HEADLINE WILL BE
WARRANTED.
AFOREMENTIONED UPSTREAM SHORTWAVE WILL CROSS OUR CWA AROUND
MIDDAY/EARLY AFTERNOON WITH NEGLIGIBLE EFFECT OTHER THAN INCREASING
CLOUD COVER AND WIND SHIFT TO A MORE WESTERLY DIRECTION AS
ASSOCIATED SURFACE TROUGH SLIDES EAST. CONVECTIVE TEMPS ARE IN THE
MID 70S THIS AFTERNOON AND EXPECT SOME MID LEVEL CU DEVELOPMENT
THIS AFTERNOON WHICH LOOKS TO SLOW TEMP RISE THIS AFTERNOON AND
LOWERED MAX TEMPS BY JUST A DEGREE OR TWO. MODEL FORECAST
SOUNDINGS SUGGEST DEEP MIXING ACROSS OUR WESTERN CWA WITH SFC DPS
DROPPING TO THE 30S THIS AFTN. LOW RELATIVE HUMIDITIES ACROSS OUR
WESTERN CWA...MAINLY DAWSON COUNTY...DROP NEAR 20 PERCENT THIS
AFTERNOON. WIND SPEEDS DO NOT APPEAR EXTREMELY STRONG BUT GUSTS
OVER 20 MPH CANNOT BE RULED OUT AND RIGHT NOW CONDITIONS APPEAR
CLOSE BUT NOT QUITE AT FIRE WEATHER CRITERIA...HOWEVER WILL NEED
TO MONITOR CONDITIONS CLOSELY THIS AFTN IN WESTERN ZONES.
HEADING INTO THE WEEKEND...DRY AND WARM...OR SHALL WE SAY HOT
CONDITIONS FOR LATE MARCH/EARLY APRIL WILL SETTLE INTO OUR REGION.
HEIGHTS RISE TONIGHT BEHIND DEPARTING SHORTWAVE TROUGH...WITH UPPER
RIDGING BUILDING ACROSS THE CENTRAL PLAINS ON SATURDAY AHEAD OF AN
UPPER TROUGH DEEPENING ALONG THE WEST COAST. THE RIDGE REMAINS IN
PLACE ACROSS THE CENTRAL PLAINS EARLY SUNDAY BEFORE FLOW
TRANSITIONS SOUTHWESTERLY BY AFTERNOON AS UPPER TROUGH MOVES INTO
THE ROCKIES. H85 TEMPS ARE RIGHT AROUND 20C BOTH SATURDAY AND
SUNDAY AND FORECAST SOUNDINGS SUGGEST MIXING WILL BE EVEN HIGHER
THAN H85. HAVE MAINTAINED UPPER 80S FOR HIGHS ON SATURDAY WITH A
DRIER AIRMASS IN PLACE AND WARMING AIDED BY DOWNSLOPE WIND
COMPONENT. BY SUNDAY LLVL FLOW TRANSITIONS SOUTHERLY WITH SFC
CYCLOGENESIS ALONG THE HIGH PLAINS AND MOISTURE RETURNS NORTH WITH
DPS RETURNING TO THE 50S. CURRENTLY HAVE HIGHS FORECAST IN THE
MID/UPPER 80S FOR SUNDAY. RECORD HIGHS BOTH SATURDAY AND SUNDAY
ARE IN THE 88 TO 90 RANGE FOR GRAND ISLAND...HASTINGS AND
KEARNEY...AND WE WILL BE RIGHT NEAR THERE.
SATURDAY WILL BE A DAY TO MONITOR FOR FIRE WEATHER CONCERNS AS WELL
AS A LARGER PORTION OF OUR CWA WILL SEE LOW RELATIVE HUMIDITIES
BELOW 20 PERCENT...BUT THAT BEING SAID...WINDS ARE NOT LOOKING
OVERLY STRONG AT THIS POINT.
UPPER TROUGH CONTINUES TO DEEPEN IN THE SOUTHERN ROCKIES SUNDAY
NIGHT AND FRONTAL PROGRESSION HAS SLOWED. WITH SLOWER FROPA...HAVE
RAISED LOW TEMPS QUITE A BIT AS DPS LOOK TO HOLD IN THE 50S FOR THE
MOST PART THROUGH THE NIGHT. WITH FRONT MAINLY TO OUR WEST OR ON
THE PERIPHERY OF OUR WESTERN COUNTIES...HAVE REMOVED POPS FOR THIS
TIME FRAME.
LONG TERM...STARTING 12Z MONDAY. GUIDANCE SUGGESTS A MID LEVEL LOW
WILL PUSH ACROSS THE SOUTHERN PLAINS DURING THE DAY MONDAY...WITH
A MID LEVEL SHORT WAVE ALSO PUSHING ACROSS THE CENTRAL AND
NORTHERN PLAINS ON MONDAY. AN ASSOCIATED LOW LEVEL BAROCLINIC ZONE
IS ALSO EXPECTED TO CLEAR OUR CWA EARLY MONDAY. ALTHOUGH THERE IS
STILL CONSIDERABLE UNCERTAINTY AS TO WHEN THE SURFACE FRONT WILL
ACTUALLY CLEAR THE AREA...INCREASED VALUES OF LOW LEVEL MOISTURE
AHEAD OF THE FRONT WILL STILL PROMOTE ENOUGH INSTABILITY FOR
CONVECTIVE DEVELOPMENT AND WITH QPF FIELDS FROM THE OPERATIONAL
GFS STILL SUGGESTING PRECIPITATION WILL BE REALIZED ACROSS OUR
EAST ON MONDAY...WILL GO AHEAD AND CONTINUE CARRYING SLIGHT
CHANCES POPS ACROSS OUR EAST FOR MONDAY. THE MID LEVEL LOW OVER
THE SOUTHERN PLAINS IS THEN EXPECTED TO LIFT TO THE NORTHEAST
MONDAY NIGHT...WITH PERHAPS ENOUGH MID LEVEL THERMAL ADVECTION TO
THE EAST AND NORTHEAST OF THE LOW FOR PRECIPITATION PRODUCTION
ACROSS PORTIONS OF OUR CWA MONDAY NIGHT INTO TUESDAY AND AS A
RESULT...WENT AHEAD AND CONTINUED SLIGHT CHANCE POPS ACROSS MUCH
OF THE CWA MONDAY NIGHT INTO TUESDAY. AN OVERALL LACK IN KINEMATIC
FORCING DUE TO STRENGTHENING UPPER LEVEL RIDGING ACROSS THE
CENTRAL CONUS SHOULD KEEP US DRY TUESDAY NIGHT THROUGH THURSDAY.
RELATIVELY COOLER WEATHER WILL BE OBSERVED DURING MUCH OF THE
EXTENDED FORECAST PERIOD AS A COOLER AIRMASS INFILTRATES OUR AREA
POST-FROPA ON MONDAY. THAT BEING SAID...TEMPERATURES ARE STILL
EXPECTED TO REMAIN AT ABOVE-NORMAL LEVELS WITH HIGHS GENERALLY IN
THE 60S AND 70S...AND LOWS GENERALLY IN THE 30S AND 40S.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ELKO NV
311 PM PDT FRI MAR 30 2012
.SYNOPSIS...VERY STRONG WINDS WILL IMPACT THE REGION TOMORROW
AHEAD OF A STRONG SURFACE COLD FRONT. BLOWING DUST AND A FEW
ISOLATED THUNDERSTORMS WILL DEVELOP AHEAD OF THE FRONT. SATURDAY
NIGHT TEMPERATURES WILL RAPIDLY DROP BEHIND THE FRONT WITH
SCATTERED SNOW SHOWERS EXPECTED DURING THE DAY ON SUNDAY. WARMING
TREND AND DRIER WEATHER IS EXPECTED FOR THE BEGINNING OF NEXT
WEEK.
&&
.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.
WIND ADVISORY UNTIL 7 PM PDT THIS EVENING FOR HUMBOLDT COUNTY.
&&
$$
95/98/98/99
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
130 PM CDT FRI MAR 30 2012
.DISCUSSION.../ISSUED AT 1045 AM CDT/
A BAND OF MID CLOUDS OVERSPREADING MUCH OF THE AREA HAS ALLOWED FOG
TO PERSIST GENERALLY EAST OF THE INTERSTATE 29 CORRIDOR THROUGH THE
MORNING...SO EARLIER EXTENDED DENSE FOG ADVISORY THROUGH 17Z.
OTHERWISE...RADAR PICKING UP A BROAD AREA OF ECHOES THROUGH THE
JAMES RIVER VALLEY WITH MID LEVEL WAVE PUSHING OUT OF CENTRAL SOUTH
DAKOTA. OBS HAVE NOT REPORTED ANY RAIN WITH THIS ACTIVITY...AND
CEILINGS ARE RUNNING AROUND 9 TO 10 KFT...SO NOT MUCH REACHING THE
GROUND AT THIS POINT...SO JUST EXPANDED THE MENTION OF SPRINKLES
EASTWARD TO I 29 INTO THE AFTERNOON. ALSO LOWERED HIGH TEMPERATURES
IN PORTIONS OF OUR NORTH AND EAST WHERE THINK CLOUDS WILL REMAIN THE
LONGEST. UPDATES OUT.
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
GENERALLY VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD WITH
RELATIVELY LIGHT SOUTHEASTERLY SURFACE FLOW AND PERIODS OF CEILINGS
IN THE 10 TO 12 KFT RANGE. CANNOT RULE OUT SOME LOCALLY REDUCED
VISIBILITIES BETWEEN 10Z TO 14Z ON SATURDAY IF WINDS GO LIGHT ENOUGH.
&&
.PREV DISCUSSION.../ISSUED AT 347 AM CDT/
AREAS OF FOG HAVE DEVELOPED OVERNIGHT EAST OF THE JAMES RIVER
VALLEY. AM WATCHING AREAS UP NORTH OF 90 AND EAST OF I-29 WHERE
VISIBILITIES HAVE CONSISTENTLY BEEN THE LOWEST DUE TO INCREASED
AMOUNTS OF LOW LEVEL MOISTURE FROM THE RAIN THURSDAY EVENING. FOG
APPEARS TO BE RELATIVELY SHALLOW RIGHT NOW...BUT RUC MODEL SOUNDINGS
SUGGESTS OVER THE NEXT FEW HOURS FOG WILL THICKEN. RAIN TOTALS WERE
FAIRLY LIGHT ESPECIALLY SOUTH OF I-90 SO THERE IS SOME QUESTION AS
TO HOW THICK THE FOG WILL GET DOW THERE. IF DENSE FOG BECOMES MORE
WIDESPREAD OVER THE PRE-DAWN HOURS...WILL ISSUE DENSE FOG ADVISORY.
OTHERWISE...EXPECTING FOG TO GRADUALLY BURN OFF TODAY LEADING TO A
PLEASANT DAY ACROSS THE AREA. SOUTHEAST WINDS WILL GRADUALLY
INCREASE FROM WEST TO EAST TODAY...BUT WILL STILL NOT BE ALL THAT
STRONG. TEMPERATURES WILL STILL BE 20-25 DEGREES ABOVE NORMAL.
GREATEST MIXING IS IN THE WEST TODAY...AND SOME CONCERN ACROSS
SOUTHWEST MINNESOTA THAT LOW LEVEL MOISTURE MAY NOT MIX OUT TODAY.
AS SUCH...ADDED MENTION OF PATCHY FOG THERE BUT MAY NEED TO BEEF UP
WORDING IN FUTURE UPDATES.
WARMING TREND EXPECTED OVER THE WEEKEND. APPEARS AS THOUGH FAIRLY
DENSE CIRRUS SHIELD WILL HINDER WARMING POTENTIAL ON
SATURDAY...HOWEVER...SUNDAY LOOKS TO BE DOWNRIGHT HOT WITH STRONG
UPPER LEVEL RIDGE BUILDING INTO THE AREA. HAVE INCREASED FORECAST
HIGHS SLIGHTLY...ESPECIALLY ACROSS WESTERN CWA WITH SLOWER
PROGRESSION OF THE FRONT. CURRENT FORECAST HIGHS ARE AROUND 3
DEGREES ABOVE RECORD IN MOST LOCATIONS.
NOT A LOT OF MOISTURE OR UPPER LEVEL DYNAMICS WITH FRONT ON SUNDAY
NIGHT. AS SUCH...CONTINUED TO DECREASE POP MENTION SUNDAY NIGHT
INTO MONDAY MORNING.
ALTHOUGH WINDS WILL BE STRONG OUT OF THE NORTHWEST AND TEMPERATURES
WILL BE MUCH COOLER THAN THE PREVIOUS DAY...TEMPERATURES STILL
APPEAR TO BE WELL ABOVE NORMAL ON MONDAY. APPEARS AS THOUGH THERE
WILL BE A GENERAL WARMING TREND NEXT WEEK...WITH THE POTENTIAL FOR
80S RETURNING BY WEEKS END.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
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 AMARILLO TX
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
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 51 88 49 91 48 / 10 0 0 0 5
BEAVER OK 51 86 51 92 50 / 10 0 0 0 5
BOISE CITY OK 48 85 49 89 46 / 5 0 0 0 5
BORGER TX 54 87 54 92 54 / 10 0 0 0 5
BOYS RANCH TX 48 88 48 92 47 / 10 0 0 0 0
CANYON TX 49 88 46 92 47 / 10 0 0 0 5
CLARENDON TX 54 88 53 93 52 / 10 0 0 0 5
DALHART TX 44 86 42 89 45 / 5 0 0 0 5
GUYMON OK 48 87 48 92 48 / 10 0 0 0 5
HEREFORD TX 47 86 47 91 46 / 5 0 0 0 5
LIPSCOMB TX 49 85 51 92 51 / 10 0 0 0 5
PAMPA TX 52 85 53 90 52 / 10 0 0 0 5
SHAMROCK TX 51 87 52 94 54 / 10 0 0 0 5
WELLINGTON TX 55 89 51 95 55 / 10 0 0 0 5
&&
.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.
&&
$$
07/08
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1251 PM CDT FRI MAR 30 2012
.DISCUSSION...SEE 18Z TAF DISCUSSION.
&&
.AVIATION...MAIN CONCERN IS HOW TO HANDLE POSSIBLE CONVECTION.
MODEL CONSENSUS SHOWING SOMETHING IN THE KLRD AREA AFTER 00Z...BUT
MODELS DIVERGE EVERYWHERE ELSE. IN SHORT...BELIEVE WITH S/W COMING
ACROSS MEXICO LATER THIS AFTERNOON AND WITH DAYTIME
HEATING...CONVECTION WILL DEVELOP LATE IN KLRD (AFTER 00Z) AND
HAVE PUT A PROB30 THERE MAINLY AFTER 03Z. ELSEWHERE...CONFIDENCE
IS NOT HIGH CONSIDERING THAT SFC/BOUNDARY LAYER WINDS ARE NOT THAT
GREAT TO PUSH MCS ACROSS THAT FAR FOR THUNDER (COULD MAYBE SEE
SHOWERS BUT NOT SURE). THUS...EXCEPT FOR VCTS AT KALI THIS
AFTERNOON...ONLY CONVECTION MENTIONED IS IN KLRD. WILL HAVE VFR
OUTSIDE OF THUNDER AT KLRD. ELSEWHERE...SKY AND VSBY CONDITIONS
WILL DETERIORATE TO AT LEAST MVFR AT KCRP (CIGS) BY 10Z...IFR AT
KALI (CIGS) BY 11Z...AND BOTTOMING OUT AT KVCT (1/2SM FG OVC002).
CONDITIONS IMPROVE AFTER 15Z. WILL HAVE TO LOOK AT MESO MODELS
MORE THOUGH FOR ZONE FORECAST...AND BRIEF NEXT SHIFT FOR 00Z TAF
ISSUANCE SHOULD SHOWERS/THUNDER NEED TO BE ADDED FARTHER WEST.
&&
.PREV DISCUSSION... /ISSUED 1044 AM CDT FRI MAR 30 2012/
DISCUSSION...ADJUSTED TEMPERATURES (ESPECIALLY HOURLY) BASED ON
OBSERVATIONS AND TRENDS...BUT OVERALL DID LOWER SOME VALUES A
DEGREE OR SO. ATMOSPHERE IS TRYING TO RE-LOAD AFTER LAST NIGHTS
ACTIVITY BUT STILL PRETTY CAPPED. STILL A CHANCE FOR AFTERNOON
CONVECTION MAINLY INLAND IF HEATING ALONG WITH SOME SURFACE
BOUNDARIES/CONVERGENT AREAS DEVELOP AS AIRMASS REMAINS PRETTY
UNSTABLE. WATER VAPOR IMAGERY SHOWING ANOTHER VERY WEAK IMPULSE
GOING INTO NORTHERN MEXICO WHICH SHOULD IMPACT WESTERN AREAS LATE
THIS AFTERNOON OR EARLY TONIGHT. ERGO...KEPT POPS IN FOR TONIGHT
AS-IS...BUT DID ADJUST SOME INLAND POPS DOWN FROM WHAT WAS
PREVIOUSLY FORECAST GIVEN THE SLIGHTLY DRIER AIRMASS TODAY AND
MORE STABLE BEGINNINGS TO SOUTH TEXAS WEATHER THIS MORNING.
UPDATED PRODUCTS OUT.
MARINE...CONVECTION OFFSHORE HAS RESULTED IN LIGHT AND VARIABLE
WINDS THIS MORNING. SHOULD RETURN TO ONSHORE FLOW THIS AFTERNOON
AS SEA BREEZE GETS GOING. KEPT SOME CONVECTION IN FOR LATER THIS
AFTERNOON BUT LIKELY ACTIVITY WILL REMAIN INLAND. NO CHANGES TO
LATTER PERIODS YET.
PREV DISCUSSION... /ISSUED 709 AM CDT FRI MAR 30 2012/
DISCUSSION...SEE AVIATION SECTION FOR 12Z TAF DISCUSSION.
AVIATION...CONDITIONS AT KVCT WILL REMAIN AT LIFR THROUGH 15Z BEFORE
GRADUALLY IMPROVING DURING THE MID TO LATE MORNING. OTHERWISE...VFR
CONDITIONS WILL PREVAIL AT OTHER TAF SITES ACROSS SOUTH TX WITH A
MID AND HIGH LEVEL DECK OF CLOUDS. A REPEAT OF LATE AFTERNOON
SHRA/TSRA ACROSS THE REGION IS POSSIBLE...BUT NOT EXPLICITLY
MENTIONED IN TAFS DUE TO TIMING CONCERNS. A VERY UNSTABLE AIRMASS
WILL BE IN PLACE TODAY WHERE AFTERNOON SCATTERED CONVECTION
DEVELOPMENT CAN BE INITIATED ON THE SEA BREEZE BOUNDARY...PARTICULARLY
ACROSS THE EASTERN COASTAL PLAINS AND BRUSH COUNTRY AFFECTING
SITES SUCH AS KCOT AND KALI BETWEEN 19-23Z. MVFR CEILINGS ARE EXPECTED
TO MOVE BACK INTO THE COASTAL PLAINS BY 03Z SATURDAY. LOOKING OUT
WEST...A COMPLEX OF THUNDERSTORMS ACROSS MEX ARE EXPECTED TO
AFFECT LRD LATER THIS EVENING TOWARD MIDNIGHT. THIS SYSTEM IS
EXPECTED TO GENERALLY MOVE SE ACROSS PORTIONS OF WEBB AND DUVAL
COUNTIES.
PREV DISCUSSION... /ISSUED 446 AM CDT FRI MAR 30 2012/
SHORT TERM (TODAY THROUGH SATURDAY)...REMNANT MCV IS APPARENT ON
SATELLITE IMAGERY OVER THE WESTERN GULF IN ASSOCIATION WITH
DECAYING CONVECTION THAT LIFTED FROM THE RGV AND TAMAULIPAS INTO
THE OFFSHORE WATERS. WEAK SUBSIDENCE WILL TAKE PLACE THIS MORNING
IN THE WAKE OF THE MCV. ATMOSPHERE WILL BECOME INCREASINGLY
UNSTABLE AS THE MORNING PROGRESSES INTO AFTERNOON. MODELS SHOW
THIS VERY UNSTABLE AIRMASS TO REMAIN OVER THE REGION TODAY.
FORECAST INSTABILITY FIELDS SHOW CAPE FROM 3500-4000 J/KG OVER THE
INLAND COASTAL PLAINS AND BRUSH COUNTRY THIS AFTERNOON WITH LIFTED
INDEX VALUES AROUND -10 TO -12 DEGREES WITH LIMITED CONVECTIVE
INHIBITION. RAISED POPS TO HIGH END CHANCES OF THUNDERSTORMS
BETWEEN THE PARALLELING HIGHWAY 16 AND HIGHWAY 281 CORRIDOR THIS
AFTERNOON. POTENTIAL FOR ISOLATED STRONG TO SEVERE THUNDERSTORMS
POSSIBLE AGAIN THIS AFTERNOON INTO THE EARLY EVENING AS SEABREEZE
PUSHES WESTWARD. TURNING THE FOCUS OUT WEST TONIGHT...GFS MODEL
INDICATES A STRONG VORT LOBE FORECAST TO MOVE TOWARD THE NUEVO
LEON/COAHUILA/TAMAULIPAS MEXICAN TRI- STATE REGION FRI NIGHT WITH
GOOD PVA...INSTABILITY...AND MOISTURE TO EXIST FOR MCS FEATURE
POSSIBLY DEVELOPING ALONG RIO GRANDE WITH CORFIDI VECTORS
SUGGESTING A TRACK TO THE SOUTHWEST THROUGH THE NIGHT.
HOWEVER...ECMWF...TEXAS TECH WRF AND HRRR NOT AS ROBUST WITH THIS
MCS POTENTIAL. PAINTED 30 TO 50 PERCENT CHANCES OF SHOWERS AND
THUNDERSTORMS MAINLY WEST OF HIGHWAY 281 DURING THE NOCTURNAL
HOURS WHILE STRATIFYING POPS TO THE LOWER SIDE TOWARD THE COAST.
QUIETER WEATHER...WITH MAINLY ISOLATED TO WIDELY SCATTERED
CONVECTION ANTICIPATED SATURDAY IN THE WAKE OF A MID LEVEL SHORT-
WAVE TROF WITH PWATS TRENDING SLIGHTLY LOWER WITH DRIER AIR
STARTING TO WORK INTO THE REGION WITH CAPES STILL REMAINING ABOVE
2500 J/KG. ABOVE NORMAL TEMPERATURES THROUGH THE SHORT TERM PERIOD
WITH BREEZY LATE MORNING AND AFTERNOON WINDS.
LONG TERM (SATURDAY NIGHT THROUGH WEDNESDAY NIGHT)...DESPITE
WEAKNESS IN FLOW ALOFT STILL EXISTING SATURDAY NIGHT...MODELS
SUGGEST MOISTURE MAY NOT BE AS IMPRESSIVE AS THE LAST FEW DAYS.
PWATS VALUES MAY DROP BELOW 1 INCH BY 12Z SUNDAY SO HAVE OPTED TO
LEAVE THUNDERSTORM CHANCES OUT OF THE FORECAST AT THIS TIME. ANOTHER
WARM DAY CAN EXPECTED ON SUNDAY ACROSS SOUTH TEXAS WITH LOWER/MID
90S IN THE BRUSH COUNTRY TO LOWER 80S ALONG THE COAST. GUIDANCE HAS
BEEN TOO WARM OUT WEST LATELY...AND WITH RECENT RAINS OVER THOSE
LOCATIONS TOOK A FEW DEGREES OFF MOS TEMPS. FOR EARLY NEXT WEEK...
TIMING OF COLD FRONT WILL REMAIN THE MAIN FORECAST CHALLENGE. MODELS
NOW OFFERING UP A CLOSED LOW SOLUTION OVER THE CENTRAL PLAINS STATES
MONDAY AND TUESDAY. COLD FRONT TIMING HAS BEEN SLOWED DOWN WITH THE
00Z RUNS AND HAVE INCORPORATED THIS INTO THE FORECAST...WITH THE GFS
BEING QUICKER THAN THE EURO WITH FROPA OFF THE COAST. FORECAST
CONFIDENCE IS NOT THE HIGHEST IN TIMING OF THE FRONT AND SUSPECT
FURTHER FINE TUNING WILL BE NEEDED. FOR NOW WILL PLACE THE FRONT
ROUGHLY THROUGH THE WESTERN HALF OF THE REGION BY 12Z TUESDAY AND
OFF THE COAST BY 18Z. ANOTHER DAY OF WARM TEMPS IN ADVANCE OF THE
FRONT WILL OCCUR ON MONDAY. INCLUDED SOME LOW END THUNDERSTORM
CHANCES MONDAY AND MONDAY NIGHT AS LIFT/INSTABILITY INCREASES AHEAD
OF UPPER TROUGH/FRONT. TEMPS WILL BE KNOCKED DOWN BY 5 TO 10 DEGREES
FOR TUESDAY AND WEDNESDAY...WITH LOWER 80S OUT WEST TO UPPER 70S
ALONG THE COAST. AS FOR THE LATTER HALF OF THE WEEK...THERE WILL BE
A SLOW RETURN IN MOISTURE AS NORTHEAST-EASTERLY FLOW AT THE SURFACE
BECOMES SOUTHEAST LATE THURSDAY. RIDGING ALOFT WILL LEAD TO PARTLY
CLOUDY SKIES IN THE AFTERNOON...QUIET WEATHER AND A GRADUAL WARMING
TREND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 87 68 86 68 87 / 30 30 20 10 10
VICTORIA 83 67 84 68 85 / 30 20 20 10 10
LAREDO 91 69 93 68 94 / 20 50 20 10 10
ALICE 89 66 89 68 89 / 30 40 30 10 10
ROCKPORT 81 69 80 70 80 / 30 20 20 10 10
COTULLA 87 65 90 67 92 / 30 50 20 10 10
KINGSVILLE 88 68 88 67 88 / 30 30 20 10 10
NAVY CORPUS 82 68 82 69 82 / 30 20 20 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
GW/86...SHORT TERM/AVIATION
RH/79...LONG TERM
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1226 PM CDT FRI MAR 30 2012
.UPDATE...
PATCHY MORNING FOG HAS SINCE DISSIPATED AND LOW CLOUDS CONTINUE TO
LIFT AND SCATTER OUT LATE THIS MORNING. HAVE UPDATED THE FORECAST TO
REFLECT THESE CHANGES AND ALSO TO SLIGHTLY ADJUST POPS FOR THIS
AFTERNOON AND EVENING. HUNG ONTO AN ISOLATED THUNDERSTORM MENTION
ACROSS MOST OF THE AREA LATE AFTERNOON TROUGH EARLY EVENING...BUT
REMOVED FROM THE FAR WEST WHERE LOW-LEVEL MOISTURE WILL CONTINUE TO
MIX OUT. ELSEWHERE...THUNDERSTORM CHANCES LOOK VERY SLIM AND EXPECT
ANY CONVECTION TO BE VERY ISOLATED IF IT DEVELOPS. LOW-LEVEL MOISTURE
/AND ASSOCIATED INSTABILITY/ WILL REMAIN IN PLACE ACROSS EASTERN AND
CENTRAL AREAS DUE TO CIRCULATION AROUND SURFACE LOW OVER THE ROLLING
PLAINS...AND DAYTIME HEATING WILL HELP TO ERODE THE CAP BY LATE IN
THE DAY. HOWEVER...AT LEAST SOME WEAK CAPPING IS EXPECTED TO REMAIN
AND NOT MUCH FORCING WILL BE AVAILABLE TO TRIGGER ANYTHING. FORCING
FROM MID-LEVEL SHORTWAVE CURRENTLY PASSING OVER THE AREA WILL SHIFT
EAST BY LATER IN THE DAY. WATER VAPOR IMAGERY AND RUC ANALYSIS DATA
DO SHOW A WEAK RIPPLE OVER SOUTH CENTRAL CO...WHICH COULD PROVIDE
SOME WEAK FORCING BUT IT MAY BE TRUMPED BY SUBSIDENCE IN WAKE OF
STRONGER LEAD WAVE. VERY WEAK UPSLOPE SURFACE FLOW WILL DEVELOP NORTH
OF THE SURFACE LOW...BUT IT WILL BE WEAK WITH NO BOUNDARIES FORESEEN
TO ENHANCE LOW-LEVEL CONVERGENCE. THUS...CHANCES OF ANYTHING
DEVELOPING ARE LOW...BUT CANNOT RULE OUT AN ISOLATED STORM OR TWO AS
SOME SHORT-RANGE MODELS SUCH AS THE RUC AND WRF-NMM CONTINUE TO
INDICATE LATE IN THE DAY AROUND PEAK HEATING. IF SOMETHING DOES
DEVELOP...IT COULD VERY WELL BE STRONG TO SEVERE AS MLCAPES WILL BE
IN THE 1500-2000 J/KG RANGE WITH DEEP-LAYER SHEAR AROUND 25-35
KTS...POSSIBLY 40 KTS EARLY THIS EVENING IN THE NORTHEAST. LARGE HAIL
WOULD BE THE MAIN HAZARD...WITH STRONG WINDS ALSO POSSIBLE.
KB
&&
.PREV DISCUSSION... /ISSUED 1219 PM CDT FRI MAR 30 2012/
AVIATION...
WEAK SHORTWAVE WILL MOVE EAST OF THE PANHANDLES THIS AFTERNOON. SUBSIDENCE
BEHIND WAVE SHOULD PRECLUDE THUNDERSTORM DEVELOPMENT AT TAF SITES.
LIGHT SOUTH SOUTHEAST LOW LEVEL FLOW COULD BRING LOW CLOUDS BACK INTO
THE PANHANDLES TONIGHT BUT CURRENT THINKING IS CLOUDS WILL BE CONFINED
TO THE EASTERN PANHANDLES AND NOT AFFECT THE TERMINALS. OVERALL...VFR
CONDITIONS TO PREVAIL ACROSS THE TAF SITES THROUGH 31/18Z.
PREV DISCUSSION... /ISSUED 708 AM CDT FRI MAR 30 2012/
AVIATION...
FOR THE 12Z TAFS...LOW CLOUDS HAVE MOVED ACROSS THE TERMINALS WITH
CONDITIONS FLUCTUATING BETWEEN MVFR AND IFR. EXPECT LOW CLOUDS TO
DISSIPATE LATER THIS MORNING WITH VFR CONDITIONS RETURNING. MEANWHILE
A COLD FRONT HAS PUSHED THROUGH THE TERMINALS WITH NORTHWEST WINDS
BEHIND THE FRONT WHILE OUTFLOW FROM ONGOING TSRA IN OKLAHOMA HAS KEPT
SURFACE WINDS OUT OF THE SOUTHEAST AT THE KAMA TERMINAL. WINDS AT
KAMA WILL VEER TO NORTH BY 15Z. A SURFACE TROUGH DIVING SOUTHEAST
INTO CENTRAL TEXAS LATER TODAY WILL KEEP WIND SPEEDS LIGHT /AT OR
UNDER 10 KTS/ THROUGH THE FORECAST PERIOD. A WEAK SHORTWAVE TROUGH
WILL CROSS THE AREA LATER TODAY WHICH CAN GENERATE ISOLATED
THUNDERSTORMS THIS AFTERNOON AND EVENING. HOWEVER LIFT ASSOCIATED
WITH THIS SYSTEM IS PRETTY WEAK AND THEREFORE CHANCES FOR TSRA TO
IMPACT ANY OF THE TERMINALS IS PRETTY SLIM SO LEFT OUT EVEN CB
REMARKS IN THE TAFS. LOW-LEVEL MOISTURE MAY INCREASE AGAIN LATE
TONIGHT/EARLY SATURDAY BUT HAVE KEPT CONDITIONS VFR FOR NOW AS
CONFIDENCE IS TOO LOW TO MENTION DETERIORATING CIGS/VISBYS WITH FOG.
CLK
PREV DISCUSSION... /ISSUED 634 AM CDT FRI MAR 30 2012/
DISCUSSION...
SFC COLD FRONT HAS PUSHED S OF FCST AREA. LOW CLOUDS AND PATCHY FOG
HAVE DEVELOPED OVER THE AREA...AND THIS IS ACCOUNTED FOR IN GRIDS.
EXPECT THE FOG AND LOW CLOUDS TO ERODE SOMETIME THIS MORNING WITH
PTCLDY SKIES FOR AFTERNOON. RETAINED A LESS THAN 20 PERCENT CHANCE OF
TSTMS OVER MOST OF AREA THIS AFTERNOON...AND SRN HALF OF TX PNHDL
THIS EVENING. IT APPEARS MAIN FORCING WILL BE OUT OF PHASE WITH
DAYTIME HEATING SO IF STORMS FORM THEY SHOULD BE RATHER ISOLATED.
WELL ABOVE NORMAL TEMPS ARE LIKELY AGAIN FOR THE WEEKEND. ALL MODELS
NOW SUGGEST NEXT VIGOROUS UPPER LEVEL LOW PRESSURE SYSTEM WILL BE EVEN
SLOWER TO ARRIVE AND MOVE ACROSS THE AREA...AND WILL ALSO HAVE MORE
OF A CLOSED OFF LOOK AS OPPOSED TO AN OPEN WAVE. THIS EXPECTED SLOWER
MOVEMENT ALSO MEANS WIND MACHINE WILL NOT CRANK UP IN EARNEST ON
SUNDAY AS EARLIER THOUGHT. IN FACT MOS WINDS FOR THAT TIME PERIOD ARE
MUCH LESS. THE WINDIER DAY APPEARS TO BE MONDAY INTO TUESDAY...AND
HAVE ADJUSTED THIS TIMING IN THE GRIDS. SPEEDS COULD APPROACH
ADVISORY LEVELS SOMETIME MONDAY.
DUE TO SLOWER AND FURTHER S PROJECTED PATH OF THIS NEXT UPPER LOW...
MOST MODELS...INCLUDING GFS AND ECMWF...PAINT WRAPAROUND QPF ACROSS
THE AREA LATE MONDAY AFTERNOON INTO TUESDAY MORNING. HAVE INTRODUCED
SLGT CHC POPS FOR RAINSHOWERS MONDAY AFTERNOON ACROSS NWRN ZONES...
THEN SPREAD THEM S AND E TO INCLUDE ALL OF FCST AREA MONDAY NIGHT.
KEPT TUESDAY DRY FOR NOW BUT IF THIS STORM SYSTEM ENDS UP EVEN SLOWER
TO MOVE OUT OF THE AREA...THEN POPS MAY BE NEEDED FOR PART OF THE AREA
ON TUESDAY. DRY WEATHER SEEN FROM TUE NIGHT ONWARD THRU REST OF
EXTENDED PERIODS.
ANDRADE
FIRE WEATHER...
ELEVATED FIRE WEATHER CONDITIONS WILL BE POSSIBLE ACROSS WESTERN AND
CENTRAL SECTIONS OF THE OK AND TX PNHDLS SATURDAY DUE TO SOUTH TO
SOUTHWEST WINDS OF 10 TO 20 MPH WITH SOME HIGHER GUSTS ALONG WITH
FORECAST MINIMUM RELATIVE HUMIDITY VALUES AROUND 15 PERCENT. CRITICAL
FIRE WEATHER CONDITIONS ARE EXPECTED ACROSS THE PNHDLS ON SUNDAY DUE
TO STRONG SW WINDS AND LOW RELATIVE HUMIDITY VALUES OF 5 TO 15
PERCENT. ELEVATED FIRE WEATHER CONDITIONS ARE ALSO ANTICIPATED ON
MONDAY ACROSS MOST OF THE AREA DUE TO STRONG WINDS AND MINIMUM
RELATIVE HUMIDITY VALUES AROUND 20 PERCENT.
ANDRADE
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
07/08
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1216 PM CDT FRI MAR 30 2012
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
329 AM CDT FRI MAR 30 2012
MAIN FORECAST CONCERNS ARE ON CLOUDS THROUGH SATURDAY MORNING AS
WELL AS TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED TROUGHING OVER THE NORTHEAST PACIFIC INTO SOUTHWEST
CANADA...WEAK RIDGING OVER ONTARIO...THEN TROUGHING IN SOUTHEAST
CANADA. SOUTH OF THE WEAK RIDGING...THERE WERE A FEW SHORTWAVES
MOVING THROUGH A NEARLY ZONAL FLOW. THE FIRST AND MOST SIGNIFICANT
ONE STRETCHED FROM NORTHEAST MINNESOTA INTO WESTERN IOWA. DPVA FROM
THIS SHORTWAVE COMBINED WITH NUMEROUS OTHER FAVORABLE PRECIPITATION
MECHANISMS WERE HELPING TO PRODUCE SHOWERS OVER MUCH OF THE FORECAST
AREA. SOME OF THE MECHANISMS INCLUDE: RIGHT ENTRANCE REGION SUPPORT
OF A 90-100 KT JET AT 200-225MB OVER NORTHERN WISCONSIN AND UPPER
MICHIGAN PER RUC ANALYSIS...ISENTROPIC LIFT/WARM ADVECTION JUST
NOTED FROM A 30-40 KT JET AT 850MB FROM LA CROSSE INTO NORTHERN
MISSOURI PER PROFILER DATA...AND A MOISTURE STREAM INDICATED BY
PRECIPITABLE WATER VALUES OF 0.75 TO 1.2 INCHES EXTENDING FROM THE
FORECAST AREA SOUTHWEST INTO MISSOURI. SCATTERED THUNDERSTORMS HAVE
ALSO OCCURRED...MAINLY SOUTH OF I-90 WHERE MUCAPE VALUES HAVE BEEN
UP AROUND 300 J/KG. ALONG AND NORTH OF I-94 WHERE TEMPERATURES ARE
IN THE LOW TO MID 30S...RESULTING FROM A COOLING AND DRYING EASTERLY
FLOW...PRECIPITATION IN THE FORMS OF RAIN...SLEET AND SNOW HAVE
OCCURRED. OTHER SHORTWAVES OF NOTE ON WATER VAPOR WITH MUCH LESS
GOING ON WERE PRESENT OVER WESTERN SOUTH DAKOTA AND FROM NORTHWEST
MINNESOTA INTO EASTERN MANITOBA. THE REASON FOR THE LACK OF ACTIVITY
WITH THESE WAVES IS MID-LEVEL DRYING...SEEN ON THE 00Z BIS...UNR AND
ABR SOUNDINGS. CLEARING LINE IS WELL OFF TO THE WEST...ALONG THE
DAKOTAS/MINNESOTA BORDER.
TODAY AND TONIGHT...CURRENT SHORTWAVE COMING INTO THE WESTERN
PORTION OF THE FORECAST AREA IS PROGGED TO MOVE ACROSS THE AREA
QUICKLY THIS MORNING...REACHING LAKE MICHIGAN BY 18Z. WITH THE FAST
PROGRESSION OF THE SHORTWAVE...ANTICIPATING ALL PRECIPITATION TO END
BY 15Z...AS PREVIOUS FORECASTS HAVE SUGGESTED. NEXT SHORTWAVE OVER
WESTERN SOUTH DAKOTA FOLLOWS QUICKLY ON ITS HEELS...CROSSING THE
FORECAST AREA LATE THIS AFTERNOON INTO THE EVENING...WITH WEAK UPPER
RIDGING THEN BUILDING IN AFTER MIDNIGHT. GIVEN LACK OF ANY ACTIVITY
UPSTREAM WITH THIS SHORTWAVE...ENVISION IT SHOULD COME THROUGH DRY.
IN FACT...THE MORE PROBLEMATIC ISSUE THROUGH TONIGHT IS CLOUD COVER.
SUBSIDENCE IN THE WAKE OF THIS MORNINGS SHORTWAVE...COMBINED WITH
RECENT MOISTURE AND AN EASTERLY LOW LEVEL FLOW...ALL WOULD SUGGEST A
CLOUDY-TYPE FORECAST IS THE WAY TO GO. DAYTIME MIXING SHOULD BE ABLE
TO GRADUALLY BREAK UP CLOUDS SOMEWHAT WEST OF THE MISSISSIPPI RIVER
THIS AFTERNOON. SOME HINTS THAT THIS CLEARING MAY SPREAD EAST INTO
WISCONSIN AFTER MIDNIGHT TONIGHT...RESULTING FROM PERSISTENT
SUBSIDENCE. ON THE OTHER HAND...CEILINGS COULD JUST LOWER INSTEAD.
ANOTHER ISSUE...WITH THAT RIDGING MOVING IN LATER TONIGHT...WARM
ADVECTION MID-CLOUDS LOOK TO RE-ENTER THE PICTURE...ESPECIALLY WEST
OF THE MISSISSIPPI RIVER. IN ADDITION...AM CONCERNED THAT LOW
STRATUS COULD RE-DEVELOP WHERE SKIES CLEAR WEST OF THE MISSISSIPPI
RIVER...RESULTING FROM RADIATIONAL COOLING AND AN UPSLOPING
SOUTHEAST WIND DEVELOPING. GIVEN THE CLOUD CONCERNS...GENERALLY TOOK
A BLEND OF ALL GUIDANCE FOR BOTH HIGHS AND LOWS. CONCERN DOES EXIST
THAT CENTRAL WISCONSIN ZONES COULD SEE FROST TONIGHT...BUT CLOUD
COVER ISSUES PRECLUDE ISSUING ANY ADVISORY AT THIS TIME.
SATURDAY AND SATURDAY NIGHT...THE WEAK UPPER RIDGING BUILDING OVER
THE AREA LATE FRIDAY NIGHT LOOKS TO CONTINUE INTO SATURDAY...
RESPONDING TO A POTENT SHORTWAVE TRACKING INTO NORTHERN ONTARIO.
UPPER RIDGING THEN RE-BUILDS BACK TO THE WEST OVER THE DAKOTAS
RESULTING FROM A DEEP SHORTWAVE TROUGH MOVING THROUGH CALIFORNIA.
DAYTIME MIXING IN CONJUNCTION WITH SUBSIDENCE UNDER THE WEAK UPPER
RIDGE SHOULD HELP BUST UP ANY MORNING LOW LEVEL STRATUS.
HOWEVER...BEING IN A WARM ADVECTION PATTERN AM CONCERNED THERE COULD
BE SOME LOW/MID CLOUDS TO DEAL WITH. BOTH THE NAM/GFS SHOW THESE
AROUND 800MB IN THE RH FIELDS...IN A NORTH-SOUTH BAND THAT MOVES
WEST TO EAST ACROSS THE FORECAST AREA THROUGH THE DAY. IN FACT...IF
YOU LIFT A PARCEL FROM 800MB IN THIS BAND...CAPE VALUES OF 300-500
J/KG ARE OBTAINABLE WITH NO CIN. ALTHOUGH NEITHER THE 30.00Z
GFS...NAM OR REGIONAL CANADIAN PRODUCE ANY QPF FROM THIS BAND...FEEL
COMPELLED TO HAVE SOME 20 PERCENT CHANCES. ACTUALLY...THE 30.00Z
UKMET PRODUCES A LITTLE LIGHT QPF. ON SATURDAY NIGHT...ANOTHER SURGE
OF ISENTROPIC LIFT NOTED ON 295-305K SURFACES IS PROGGED TO MOVE
INTO/THROUGH THE AREA. THE UKMET IS BY FAR THE MOST BULLISH WITH
CONVECTION...THOUGH THE HEAVIEST PORTION IS CENTERED OVER NORTHERN
ILLINOIS. THE 30.00Z GFS/NAM BOTH DEVELOP CONVECTION...MAINLY OVER
THE SOUTHEAST HALF BETWEEN 06-12Z SUNDAY. EITHER WAY...SOME
PRECIPITATION CHANCES ARE WARRANTED...WHICH HAVE BEEN RAISED ABOUT
10 PERCENT FROM THE PREVIOUS FORECAST. WITH MORE CLOUDS TO DEAL WITH
ON SATURDAY AND 925MB TEMPS ONLY REACHING 10-14C BY 00Z...LOWERED
HIGHS 3-4 DEGREES. CONTINUOUS WARM ADVECTION THROUGH MUCH OF
SATURDAY NIGHT SHOULD HELP TO KEEP TEMPERATURES UP AND PREVIOUS
FORECAST LOWS SEEM REASONABLE.
SUNDAY AND SUNDAY NIGHT...UPPER RIDGING OVER THE NORTHERN PLAINS IS
EXPECTED TO GRADUALLY SHIFT EAST...MOVING OVER THE FORECAST AREA
SUNDAY NIGHT. AGAIN...THIS IN RESPONSE TO THE DEEP TROUGHING OVER
THE WESTERN U.S. SLOWLY MOVING EAST. THIS UPPER RIDGE IS STRONGER
THAN THE PREVIOUS COUPLE ONES MOVING THROUGH...SO ITS SUBSIDENCE
SHOULD BE STRONGER. INDEED...MOST MODELS KEEP THE FORECAST AREA DRY
THROUGH SUNDAY NIGHT AND HAVE TRENDED THE FORECAST IN THIS
DIRECTION. THIS LEAVES TEMPERATURES THE BIGGER ISSUE. WITH A MORE
AMPLIFIED LOOK TO THE UPPER RIDGING...THAT WARM FRONT MENTIONED IN
PREVIOUS DISCUSSIONS TO COME THROUGH ON SUNDAY MAY END UP STAYING
ALONG OR SOUTH OF I-90. IN FACT...THE 30.00Z GFS/UKMET HINT AT
BACKDOOR COLD FRONT POTENTIAL. STILL...IT SEEMS LIKE A SOLID BET FOR
SUNDAY TO END UP QUITE A BIT WARMER THAN SATURDAY...ESPECIALLY WEST
OF THE MISSISSIPPI RIVER WHERE 925MB TEMPERATURE CONSENSUS SUGGESTS
READINGS OF 20-22C. CLOSER TO CENTRAL WISCONSIN...14-16C READINGS
SHOULD BE MORE COMMON. WITH THE COOLER TREND NOTED IN MODELS...DID
KNOCK HIGHS BACK A FEW DEGREES OVER WISCONSIN AREAS. FURTHER
LOWERING MAY BE REQUIRED DEPENDING ON THE BACKDOOR COLD FRONT
POTENTIAL. WARM AIR SHOULD HOLD IN HERE SUNDAY NIGHT...IN
COMBINATION WITH THE UPPER RIDGE AND WITH A LOW PRESSURE SYSTEM
TRYING TO APPROACH THE AREA FROM THE CENTRAL PLAINS. PREVIOUS LOW
TEMPERATURE FORECAST LOOKS ON TRACK.
.LONG TERM...MONDAY THROUGH THURSDAY NIGHT
329 AM CDT FRI MAR 30 2012
TREND IN THE RECENT 30.00Z GFS/ECMWF/UKMET/CANADIAN IS TO SUGGEST
THAT THE WESTERN TROUGHING IS GOING TO SPLIT INTO TWO. THE SOUTHERN
END CUTS OFF OVER TEXAS FOR MUCH OF THE LONG TERM PERIOD...WHILE THE
NORTHERN END COMES THROUGH THE FORECAST AREA ON TUESDAY. THIS IS
SLOWER THAN PREVIOUSLY FORECAST...AND IN FACT IF THE 30.00Z ECMWF IS
CORRECT...MONDAY COULD BE A VERY WARM AND EVEN HUMID DAY ACROSS MUCH
OF THE FORECAST AREA. SUGGESTION FROM THE MODEL IS HIGHS IN THE LOW
80S AND DEWPOINTS IN THE LOW 60S...ALL FROM THE LOW PRESSURE SYSTEM
IN THE CENTRAL PLAINS LIFTING NORTHEAST INTO NORTHWEST WISCONSIN.
HAVE NOT JUMPED ON THIS SCENARIO QUITE YET...SINCE MOST MODELS KEEP
THIS SYSTEM TO THE SOUTH OF THE AREA...BUT DEFINITELY WARRANTS
WATCHING. ALSO THE ECMWF WOULD SUGGEST SOME STRONG CONVECTION AT
LEAST AS THE COLD FRONT COMES THROUGH. NEEDLESS TO SAY...CHANCES OF
PRECIPITATION CONTINUE IN THE FORECAST FOR MONDAY INTO MONDAY
NIGHT...MAINLY IN THE 20-40 RANGE UNTIL THIS WHOLE SYSTEM CAN BE
IRONED OUT. DRYING TREND THEN IS FORECAST FOR TUESDAY AND CONTINUING
THROUGH THE REST OF THE LONG TERM PERIOD WITH MOST MODELS AND
ENSEMBLES SHOWING NORTHWEST FLOW OVER THE FORECAST AREA. DID KEEP A
20 PERCENT CHANCE OF SHOWERS GOING ON TUESDAY WITH THE UPPER TROUGH
MOVING THROUGH...THOUGH. HOW MUCH NORTHWEST FLOW AND THE COLD AIR
ASSOCIATED WITH IT VARIES...SO FOR NOW STAYED WITH A BLEND OF MODELS
FOR TEMPERATURES. READINGS STILL LOOK TO STAY ABOVE NORMAL AS HIGHS
ONLY DROP INTO THE MID TO UPPER 50S AT THE LOWEST. NORMAL HIGHS ARE
IN THE LOW 50S.
&&
.AVIATION...THROUGH 18Z SATURDAY
1216 PM CDT FRI MAR 30 2012
VISIBLE SATELLITE SHOWING A LARGE AREA OF IFR/MVFR CLOUDS
COVERING MUCH OF THE UPPER MIDWEST. LOOKING AT THE 30.12Z
NAM...NOT EXPECTING THESE CLOUDS TO DISSIPATE ANYTIME SOON AS THE
RELATIVE HUMIDITY AT 925 MB IS EXPECTED TO STAY HIGH INTO SATURDAY
MORNING. THE CONCERN IS WHETHER THERE WILL BE ANY BREAK IN THE
CLOUDS THIS EVENING. THE NAM BUFKIT SOUNDINGS WOULD SUGGEST THE
LOW CLOUDS BREAKING UP FOR A WHILE THIS EVENING AS DOES THE 30.12Z
HRRR BEFORE THEY REFORM OVERNIGHT. THE WESTERN EDGE OF THE CLOUDS
ACROSS WESTERN MINNESOTA AND IOWA DO SHOW SIGNS OF BREAKING UP BUT
NOT SURE IF THIS WILL BE ABLE TO WORK EAST INTO THE AREA GIVEN THE
LIGHT FLOW IN THE LOW LEVELS. FOR NOW...WILL CONTINUE THE TRENDS
OF KEEPING THE CLOUDS IN THROUGH THE EVENING AND THEN LOWERING
THEM BACK TO IFR OVERNIGHT WITH SOME COOLING. WILL NOT INCLUDE ANY
FOG OVERNIGHT AT EITHER SITE AS THE WINDS SHOULD BE INCREASING OUT
OF THE SOUTHEAST AS AN AREA OF HIGH PRESSURE MOVES OFF TO THE EAST
AND THE NEXT FRONT MOVES INTO THE DAKOTAS.
&&
.HYDROLOGY...
329 AM CDT FRI MAR 30 2012
AS OF 3 AM...MAJORITY OF THE PRECIPITATION SO FAR HAS FALLEN
ALONG AND SOUTH OF A LINE FROM ST ANSGAR IOWA TO WINONA MN AND
BLACK RIVER FALLS WISCONSIN. RADAR ESTIMATES SHOW THAT THE SHOWERS
AND THUNDERSTORMS PRODUCED AMOUNTS RANGING FROM 0.25 TO 0.75
INCHES. HOWEVER...THERE IS AN AREA COVERING SOUTHEAST
FAYETTE...MUCH OF CLAYTON AND NORTHERN GRANT COUNTIES WHERE 0.75
TO 1.75 INCHES FELL...HIGHEST NEAR STRAWBERRY POINT. NO REPORTS OF
ANY FLOODING THUS FAR BUT EXPECT SOME BRIEF RISES IN SMALL
STREAMS. WILL HAVE TO KEEP AN EYE ON THE TURKEY RIVER...THOUGH
THE LACK OF SIGNIFICANT RAINFALL AND GENERALLY DRY SOILS SHOULD
KEEP THE RIVER BELOW FLOOD STAGE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
328 AM CDT FRI MAR 30 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
HYDROLOGY...AJ