Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 04/01/12
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 CHICAGO/ROMEOVILLE IL
1010 PM CDT SAT MAR 31 2012
.DISCUSSION...
908 PM CDT
SOME MINOR CHANGES TO POPS AND WX FOR TONIGHT. MAINLY DELAYING
ARRIVAL OF THREAT OF SHRA AND TSRA UNTIL LATER TONIGHT AND
REDUCING POPS OVER FAR NE IL FOR OVERNIGHT.
RADAR COMPOSITE SHOWS WEAK ECHOES TO THE W THRU N OF THE LOCAL
AREA WHERE INITIAL WAA AND RESULTING UVV AT MAINLY MID LEVELS
OCCURRING. EXPECT THESE ECHOES...ALREADY MOSTLY VIRGA UPSTREAM
WITH FEW IF ANY METARS REPORTING ANY PRECIP...WILL CONTINUE TO
DRY UP AS THEY MOVE INTO INCREASINGLY DRY MID AND LOW LEVELS.
A THUNDERSTORM DEVELOPED JUST NE OF DSM AROUND 0030Z AND ARE
SLOWLY INCREASING IN NUMBER AS THEY MOVE ENE-E. THESE TSRA ARE
WHERE BETTER MOISTURE IN THE 850 TO 800 HPA LAYER IS IN
PLACE...WHERE WEAK SURFACE CONVERGENCE IS OCCURRING...WHERE NOSE
OF 45 KT SOUTHWESTERLY JET AT 5 TO 6 K FT AGL SHOWN BY KDMX VAD
WIND PROFILE IS LOCATED...AND JUST AHEAD OF WEAK MID LEVEL SHORT
WAVE TROF MOVING OVER CENTRAL IA.
CHALLENGE TO FORECAST IS HOW EXTENSIVE FURTHER TSRA DEVELOPMENT
WILL BE AND WHERE AREA OF STORMS IS LIKELY TO MOVE OVERNIGHT.
LATEST RUC13 RUN INDICATES A RATHER SMALL AREA OF MID LEVEL
ISENTROPIC LIFT CURRENTLY OVER CENTRAL IA MOVES THIS AREA
EASTWARD TO E CENTRAL IA 04-06Z...AND THEN SOUTHEASTWARD ACROSS
N CENTRAL IL TO THE CENTRAL IL-IND BORDER BY 12Z. THIS APPEARS TO
BE BEST TRACK FOR THE ELEVATED TSRA THAT IS EXPECTED TO BE
MAINTAINED THROUGH THE OVERNIGHT BY THE LLJ...THE MID LEVEL SHORT
WAVE AND STEEPENING MID LEVEL LAPSE RATES.
EXPECT RATHER SMALL AREA OF TSRA AS MOISTURE WILL BE MARGINAL SO
ONLY ANTICIPATE ACTIVITY WHERE FORCING FACTORS ARE MAXIMIZED
DURING THE OVERNIGHT.
TRS
//PREV DISCUSSION...
317 PM CDT
MAIN FORECAST ISSUES/CONCERNS FOR THE REMAINDER OF THE WEEKEND ARE
WITH CHANCES FOR SHOWERS/THUNDERSTORMS LATE TONIGHT INTO SUNDAY
MORNING...AS WELL AS TEMPERATURE TRENDS SUNDAY.
WITH THE LOW LEVEL CLOUD COVER TODAY MASKING THE FACT THAT HIGH
PRESSURE IS OVERHEAD...RELATIVELY QUIET CONDITIONS HAVE BEEN IN
PLACE FOR ALL OF TODAY. ALTHOUGH...OVER THE LAST COUPLE OF HOURS
SEVERAL HOLES DEVELOPED WITHIN THIS LOW LEVEL MOISTURE. A WARM SUN
AND DRIER AIR ALOFT HAS ALLOWED FOR THESE HOLES TO CONTINUE TO
EXPAND WITH SOME AREAS ACROSS THE SOUTHERN CWA OBSERVING SUNNY TO
PARTLY CLOUDY SKIES. WITHIN THESE AREAS OF BETTER SOLAR
INSOLATION...TEMPS HAVE QUICKLY RISEN INTO THE 50S WITH SOME AREAS
OBSERVING SOME PLEASANT CONDITIONS AS RATHER LIGHT FLOW REMAINS IN
PLACE. EXPECT THIS LOW CLOUD SHIELD TO CONTINUE TO ERODE WITH TIME
LATE THIS AFTERNOON AND EARLY EVENING BUT WITH SOME MID AND HIGH
LEVEL CLOUD COVER TO PUSH OVERHEAD. THIS IN ITSELF SHOULD PROVIDE
PARTLY CLOUDY SKIES FOR TONIGHT...BUT WITH PRECIP CHANCES LATER
TONIGHT TO POSSIBLY BRING MORE CLOUDY CONDITIONS MORE TOWARDS
EARLY SUNDAY MORNING.
LATEST GUIDANCE CONTINUES TO INDICATE SHOWERS AND THUNDERSTORMS
DEVELOPING TONIGHT ACROSS EASTERN IOWA AND SHIFTING EAST/SOUTHEAST
ACROSS A PORTION OF THE CWA THROUGH SUNDAY MORNING. ALL GUIDANCE
IS INDICATING THIS POSSIBILITY BUT WITH SOME VARIABILITY STILL
REMAINING WITH REGARDS TO EXACT TIMING AND PLACEMENT/TRACK. WITH
BACKING 850MB FLOW...A WARMER AND MORE MOIST AIR MASS LOCATED
ACROSS THE CENTRAL PLAINS WILL ADVECT NORTH/NORTHEAST WITH TIME
TONIGHT BRINGING HIGHER DEW POINT AIR TO THE REGION. NORTHWEST FLOW
ALOFT WILL STEER A MID LEVEL IMPULSE AND ATTENDANT SURFACE TROUGH
OUT OF THE NORTHERN PLAINS THIS EVENING...AND HELP TO INITIATE
CONVECTION ALONG A LOW LEVEL BAROCLINIC ZONE DRAPED ACROSS THE
REGION. WITH LOW LEVEL FLOW FEEDING HIGHER THETA E AIR OVER THIS
BOUNDARY AND INTO ANY DEVELOPING PRECIP...THIS AREA OF CONVECTION
COULD SEE SOME EXPANSION IN COVERAGE AS IT SHIFTS EAST/SOUTHEAST
THROUGH THE CWA EARLY SUNDAY MORNING. ALTHOUGH...GUIDANCE
CONTINUES TO STRUGGLE WITH EXACT TIMING OF WHEN CONVECTION WILL
DEVELOP AND WHERE THIS DEVELOPING AREA OF PRECIPITATION WILL
PROGRESS THROUGH. DUE TO THIS UNCERTAINTY STILL IN PLACE...HAVE
NOT MADE MANY CHANGES TO THE GOING POP GRIDS FOR TONIGHT KEEPING
HIGH CHANCE POPS FOR MUCH OF THE CWA AFTER THE MIDNIGHT TIME FRAME
THROUGH MID MORNING SUNDAY. THIS IS BASED ON THE LIKELIHOOD THAT
CONVECTION SHOULD BEGIN TO DEVELOP OVER IOWA ONCE WE DECOUPLE AND
THE LLJ RAMPS UP...WHICH SHOULD BE AROUND THE 3Z-6Z TIME FRAME.
SOME HI RES DATA IS SHOWING THE POSSIBILITY OF AN MCS DEVELOPING
AND QUICKLY SHIFTING THROUGH THE REGION SUNDAY MORNING. HAVE NOT
COMPLETELY THROWN THIS OUT AS A POSSIBILITY...WITH DECENT LOW
LEVEL SHEAR TO BE PRESENT ACROSS THE REGION. A LIMITING FACTOR
WILL BE THE AMOUNT OF INSTABILITY PRESENT OVER NORTHERN ILLINOIS
AND NORTHWEST...WHICH AM CURRENTLY LEANING MORE ON THE SREF MUCAPE
OUTPUT WHICH IS SHOWING WEAKER INSTABILITY PRESENT BY EARLY SUNDAY
MORNING LIMITING MORE ROBUST CONVECTION...WITH OTHER GUIDANCE OF
COURSE ALSO VARYING TO THIS AMOUNT. SO WITH ANY PRECIP WHICH MOVES
THROUGH THE AREA LATE TONIGHT AND EARLY SUNDAY MORNING...A MORE
LIKELY SCENARIO WILL BE FOR THIS TO BE AN UNORGANIZED AREA OF
SHOWERS AND ELEVATED THUNDERSTORMS WITH LITTLE CHANCES FOR SEVERE
WEATHER...HAIL/WIND. ONLY AN ISOLATED THREAT OF HAIL COULD BE
OBSERVED MAINLY FOR THE WESTERN CWA WHERE BETTER INSTABILITY AND
STRONGER EFFECTIVE BULK SHEAR WILL RESIDE. EVEN IF A MORE
ORGANIZED MCS COULD DEVELOP...WOULD EXPECT IT TO FOLLOW THE HIGHER
SURFACE DEW POINT AIR AND BETTER INSTABILITY WHICH WOULD MORE THAN
LIKELY BE SITUATED TO THE SOUTH OF THE CWA. THUS...ONCE AGAIN
KEEPING ANY THREAT FOR SEVERE WEATHER JUST OUTSIDE OF THE CWA.
THIS SITUATION WARRANTS CONTINUED MONITORING...AND WILL MAINTAIN A
MENTION FOR THE CHANCES FOR THUNDERSTORMS TONIGHT IN THE HWO.
ANY LINGERING SHOWERS/THUNDERSTORMS SHOULD EXIT THE CWA BY MID DAY
WITH PARTLY CLOUDY TO SUNNY CONDITIONS EXPECTED THROUGH THE
AFTERNOON. THE EXTENT OF THE MORNINGS PRECIP WILL DEFINITELY PLAY
A KEY ROLE WITH MAX TEMPS ON SUNDAY WITH PERSISTENT WAA ADVECTING
A WARMER AIR MASS OVERHEAD. AS SURFACE WARM FRONT TRIES TO LIFT
NORTHEAST ACROSS THE CWA DURING THE DAY SUNDAY...IT WILL ACTUALLY
BEGIN TO RETREAT AS A COLD FRONT WITH COOLER LOW LEVEL AIR WORKING
ITS WAY BACK WEST ACROSS THE CWA LATE IN THE AFTERNOON AND EARLY
EVENING. SO OUTSIDE OF PRECIP TRENDS POSSIBLY AFFECTING TEMP
TRENDS SUNDAY...PLACEMENT OF THIS BOUNDARY AND MOVEMENT WILL BE
KEY IN DEFINING MAX TEMPS FOR SUNDAY. DID BRING DOWN TEMPS A TAD
FROM GOING FORECAST BUT HAVE KEPT THE WEST/SOUTHWEST CWA WARMER
THAN THE EAST WITH AREAS STILL TO POSSIBLY REACH THE 80 MARK...AND
AREAS ACROSS THE EASTERN CWA TO REACH THE LOWER 70S WITH 60S
EXPECTED FOR AREAS NEAR THE LAKE. HAVE ADDED SLIGHT CHANCE POPS
FOR THE SOUTHEAST PORTION OF THE CWA FOR SUNDAY AFTERNOON WHERE
BETTER FOCUS AND UPPER LEVEL SUPPORT COULD PROVIDE FOR DEVELOPMENT
OF THUNDERSTORMS.
STRONG UPPER LEVEL RIDGING WILL OCCUR ON MONDAY WITH MID AND UPPER
LEVEL FLOW BECOMING RATHER WEAK. THIS WEAK FLOW COINCIDING WITH A
FORECASTED CLOSED UPPER LEVEL LOW TRACKING THROUGH THE SOUTHERN US
WILL PROVIDE A TRICKY FORECAST THROUGH THE REMAINDER OF THE WEEK
WITH THE ANTICIPATION FOR GUIDANCE TO CONTINUE TO STRUGGLE WITH
PLACEMENT OF LOW LEVEL FEATURES AND INEVITABLE PRECIP.
ALTHOUGH...THERE DOES APPEAR TO BE BETTER CHANCES FOR OBSERVING
CONVECTION MONDAY NIGHT. BETTER FORCING AS WELL AS INSTABILITY
LOOK TO BE IN PLACE FOR THE DEVELOPMENT OF POSSIBLY MORE ORGANIZED
CONVECTION...WITH CURRENT GUIDANCE INDICATING BETTER CHANCES
RESIDING ACROSS NORTHERN ILLINOIS INTO EARLY TUESDAY MORNING. HAVE
NOT GONE OVERLY EXCITED WITH POPS DURING THIS TIME FRAME AS THE
ECMWF REMAINS THE OUTLIER KEEPING A SURFACE LOW AND FORCING/PRECIP
OFF TO THE WEST FOR MOST OF MONDAY AND MONDAY NIGHT. IF THIS WERE
TO COME INTO FRUITION...THAN DRIER CONDITIONS WOULD BE OBSERVED
MONDAY NIGHT WITH PRECIP DELAYED UNTIL TUESDAY.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* POTENTIAL FOR THUNDERSTORMS AFTER 08-09Z.
* WINDS SHIFTING NORTHEAST 10-15 KT BY LATE SUNDAY MORNING.
* POTENTIAL FOR A PERIOD OF MVFR CEILINGS AROUND 1500 FT BEHIND
WIND SHIFT AND LASTING INTO MID AFTERNOON BEFORE SCATTERING.
RATZER
//DISCUSSION...UPDATED 03Z...
ISOLATED STRONG THUNDERSTORMS HAVE DEVELOPED OVER EAST CENTRAL
IOWA AS EARLIER ANTICIPATED...AND WERE CLUSTERED ROUGHLY KCID AND
KMLI AT 03Z. RADAR TRENDS INDICATE A SOUTHEASTWARD PROPAGATION
AS SUPPORTED BY THE LARGE SCALE THERMAL/THICKNESS FIELD...SO
CURRENT STORMS SHOULD PASS LARGELY SOUTH OF THE TERMINALS LATER
TONIGHT. HOWEVER...HIGH-RES CONVECTION ALLOWING GUIDANCE CONTINUES
TO SUGGEST ADDITIONAL DEVELOPMENT OVER FAR NORTHERN/NORTHEAST IL
IN THE 08-10Z TIME FRAME...WHICH WOULD LIKELY IMPACT THE TERMINALS
VERY CLOSELY IF NOT DIRECTLY IF IT DOES DEVELOP. GUIDANCE HAS BEEN
CONSISTENT IN THIS SIGNAL...SO HAVE ELECTED TO CONVERT PROB30
GROUPS TO TEMPOS FOR THE AIRPORTS EARLY SUNDAY MORNING. HAVE TRIED
TO NARROW DOWN A 2-3 HOUR WINDOW OF GREATEST PROBABILITY...THOUGH
MAY HAVE TO ADJUST LATER IN THE NIGHT BASED ON ACTUAL CONVECTIVE
DEVELOPMENT.
RATZER
PREVIOUS DISCUSSION FROM 00Z...
MAIN CONCERNS WITH 00Z TAFS ARE POTENTIAL FOR TSRA LATE TONIGHT
INTO EARLY SUNDAY...AS WELL AS THE POTENTIAL FOR A PERIOD OF MVFR
CEILINGS DURING THE DAY SUNDAY AS WINDS TURN NORTHEAST OFF THE
LAKE.
HIGH PRESSURE WAS CENTERED OVER THE CENTRAL GREAT LAKES EARLY THIS
EVENING...WHILE A WEAK AREA OF LOW PRESSURE WAS NOTED OVER THE
MID-MISSOURI RIVER VALLEY NORTH OF OMAHA. THIS LOW WILL WEAKEN
WHILE MOVING EAST ACROSS NORTHERN ILLINOIS BY SUNDAY MORNING. AS
THE LOW ADVANCES...WARM MOIST AND UNSTABLE AIR WILL BE FORCED
OVER A WARM FRONT EXTENDING FROM SOUTHEAST IOWA INTO CENTRAL
ILLINOIS. FORECAST SOUNDINGS DEPICT CONSIDERABLE ELEVATED
INSTABILITY TO BE IN PLACE ACROSS EASTERN IOWA AND NORTHERN
IL...WHICH COMBINED WITH A 35 KT WEST-SOUTHWEST LOW LEVEL JET AND
A SMALL AMPLITUDE SHORT WAVE MOVING FROM IA/MN INTO IL BY 12Z
SUNDAY SHOULD ALLOW FOR THUNDERSTORM DEVELOPMENT. HIGH-RES MODELS
INDICATE CONVECTIVE INITIATION WILL TAKE PLACE OVER CENTRAL-EASTERN
IA THIS EVENING...WITH ELEVATED STORMS THEN SPREADING EAST
INTO NORTHERN AND CENTRAL IL AROUND/AFTER MIDNIGHT. WHILE THE
OVERALL POTENTIAL FOR THUNDERSTORM DEVELOPMENT APPEARS FAIRLY
HIGH...THE MAIN QUESTION IS WHETHER THEY WILL DIRECTLY IMPACT THE
TERMINALS. THE COMBINATION OF THE LOW LEVEL JET VEERING WEST
OVERNIGHT AND THE NORTHWEST TO SOUTHEAST ORIENTATION OF THE LARGER
SCALE THERMAL FIELD SUGGESTS THAT STORMS MAY SCOOT JUST SOUTH OF
RFD-ORD-GYY. THUS OVERALL CONFIDENCE IS FAIRLY HIGH THAT STORMS
WILL DEVELOP AND BE CLOSE TO THE TERMINAL/TRACON AIRSPACE...BUT
LOW THAT THEY WILL MOVE OVER ANY PARTICULAR TERMINAL. WILL HAVE TO
WATCH TO SEE WHERE INITIATION OCCURS TO OUR WEST THIS EVENING TO
GET A BETTER HANDLE ON TRENDS FARTHER TO THE EAST LATE TONIGHT.
ONCE SHOWERS/THUNDERSTORMS MOVE EAST WITH MID-LEVEL AND SURFACE
WAVES SUNDAY MORNING...CONCERNS SHIFT TO POTENTIAL FOR MVFR
CEILINGS AS LOW LEVEL WINDS SHIFT TO THE NORTHEAST WITH A
REINFORCING COOL FRONT. FORECAST SOUNDINGS COOL/SATURATE THE
SHALLOW BOUNDARY LAYER WITH CLOUD BASES EXPECTED TO BE AROUND THE
1500 FT LEVEL...WITH DRYING/SCATTERING INDICATED BY MID/LATE
AFTERNOON.
WINDS...LIGHT EAST-SOUTHEAST WINDS TO BECOME SOUTH OVERNIGHT.
WINDS MAY BECOME LIGHT/VARIABLE FOR A TIME SUNDAY MORNING IN
VICINITY OF THE SURFACE LOW PRESSURE WAVE...THEN SHOULD SHIFT TO
THE NORTHEAST WITH GUSTS AROUND 15 KTS AS FRONT SAGS THROUGH AREA
BY MID/LATE MORNING.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM-HIGH CONFIDENCE IN TSRA DEVELOPMENT ACROSS FAR NORTHERN
IL TONIGHT...BUT LOW CONFIDENCE ON DIRECT IMPACT TO TERMINALS
AT THIS TIME.
* MEDIUM CONFIDENCE IN CEILING TRENDS SUNDAY.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR WITH CHANCE TSRA MONDAY NIGHT.
TUESDAY...VFR WITH CHANCE SHRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
RATZER
&&
.MARINE...
115 PM CDT
WINDS WILL TURN SOUTHERLY AND GRADUALLY INCREASE ACROSS LAKE MI
TONIGHT AS HIGH PRESSURE MOVES EAST FROM THE CENTRAL GREAT LAKES.
LOW PRESSURE WILL EVOLVE EASTWARD ACROSS THE LAKE ON SUNDAY MORNING.
AN ASSOCIATED COLD FRONT WILL SLIP SOUTH AS THIS OCCURS...TURNING
WINDS NORTHERLY ACROSS THE LAKE. THIS FRONT WILL LIKELY MOVE ACROSS
THE NEARSHORE AREAS OF IL AND IN DURING THE EARLY TO MID AFTERNOON
ON SUNDAY. HIGH PRESSURE WILL BRIEFLY PREVAIL ON SUNDAY NIGHT BEFORE
ANOTHER LOW MOVES EAST ACROSS IOWA INTO NORTHERN ILLINOIS. WINDS ARE
EXPECTED TO TURN BACK SOUTHEAST AHEAD OF THIS FEATURE ON MONDAY
AFTERNOON...WITH SOME GUSTS UP TO 25 KT...INCLUDING POSSIBLY IN THE
ILLINOIS NEAR SHORE AREAS. BEHIND THE LOW PASSAGE LATE MONDAY NIGHT
INTO EARLY TUESDAY...THE WINDS WILL ONCE AGAIN SWING BACK NORTHERLY.
HIGH PRESSURE IS THEN FORECAST TO ENCOMPASS MUCH OF THE LAKE
WEDNESDAY THROUGH FRIDAY...THOUGH CONFIDENCE IN THIS IS FAIRLY LOW
DUE TO A CLOSED UPPER LOW IN THE CENTRAL PLAINS WHICH COULD MEANDER
CLOSE ENOUGH TO CAUSE SLIGHTLY STRONGER WINDS. OVERALL AT THIS
TIME...NO LONG-LIVED GUSTY OR HIGH WAVE PERIODS ARE EXPECTED IN
THE NEXT WEEK.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
909 PM CDT SAT MAR 31 2012
.DISCUSSION...UPDATE FOR REST OF TONIGHT...
908 PM CDT
SOME MINOR CHANGES TO POPS AND WX FOR TONIGHT. MAINLY DELAYING
ARRIVAL OF THREAT OF SHRA AND TSRA UNTIL LATER TONIGHT AND
REDUCING POPS OVER FAR NE IL FOR OVERNIGHT.
RADAR COMPOSITE SHOWS WEAK ECHOES TO THE W THRU N OF THE LOCAL
AREA WHERE INITIAL WAA AND RESULTING UVV AT MAINLY MID LEVELS
OCCURRING. EXPECT THESE ECHOES...ALREADY MOSTLY VIRGA UPSTREAM
WITH FEW IF ANY METARS REPORTING ANY PRECIP...WILL CONTINUE TO
DRY UP AS THEY MOVE INTO INCREASINGLY DRY MID AND LOW LEVELS.
A THUNDERSTORM DEVELOPED JUST NE OF DSM AROUND 0030Z AND ARE
SLOWLY INCREASING IN NUMBER AS THEY MOVE ENE-E. THESE TSRA ARE
WHERE BETTER MOISTURE IN THE 850 TO 800 HPA LAYER IS IN
PLACE...WHERE WEAK SURFACE CONVERGENCE IS OCCURRING...WHERE NOSE
OF 45 KT SOUTHWESTERLY JET AT 5 TO 6 K FT AGL SHOWN BY KDMX VAD
WIND PROFILE IS LOCATED...AND JUST AHEAD OF WEAK MID LEVEL SHORT
WAVE TROF MOVING OVER CENTRAL IA.
CHALLENGE TO FORECAST IS HOW EXTENSIVE FURTHER TSRA DEVELOPMENT
WILL BE AND WHERE AREA OF STORMS IS LIKELY TO MOVE OVERNIGHT.
LATEST RUC13 RUN INDICATES A RATHER SMALL AREA OF MID LEVEL
ISENTROPIC LIFT CURRENTLY OVER CENTRAL IA MOVES THIS AREA
EASTWARD TO E CENTRAL IA 04-06Z...AND THEN SOUTHEASTWARD ACROSS
N CENTRAL IL TO THE CENTRAL IL-IND BORDER BY 12Z. THIS APPEARS TO
BE BEST TRACK FOR THE ELEVATED TSRA THAT IS EXPECTED TO BE
MAINTAINED THROUGH THE OVERNIGHT BY THE LLJ...THE MID LEVEL SHORT
WAVE AND STEEPENING MID LEVEL LAPSE RATES.
EXPECT RATHER SMALL AREA OF TSRA AS MOISTURE WILL BE MARGINAL SO
ONLY ANTICIPATE ACTIVITY WHERE FORCING FACTORS ARE MAXIMIZED
DURING THE OVERNIGHT.
TRS
&&
.PREV DISCUSSION...
317 PM CDT
MAIN FORECAST ISSUES/CONCERNS FOR THE REMAINDER OF THE WEEKEND ARE
WITH CHANCES FOR SHOWERS/THUNDERSTORMS LATE TONIGHT INTO SUNDAY
MORNING...AS WELL AS TEMPERATURE TRENDS SUNDAY.
WITH THE LOW LEVEL CLOUD COVER TODAY MASKING THE FACT THAT HIGH
PRESSURE IS OVERHEAD...RELATIVELY QUIET CONDITIONS HAVE BEEN IN
PLACE FOR ALL OF TODAY. ALTHOUGH...OVER THE LAST COUPLE OF HOURS
SEVERAL HOLES DEVELOPED WITHIN THIS LOW LEVEL MOISTURE. A WARM SUN
AND DRIER AIR ALOFT HAS ALLOWED FOR THESE HOLES TO CONTINUE TO
EXPAND WITH SOME AREAS ACROSS THE SOUTHERN CWA OBSERVING SUNNY TO
PARTLY CLOUDY SKIES. WITHIN THESE AREAS OF BETTER SOLAR
INSOLATION...TEMPS HAVE QUICKLY RISEN INTO THE 50S WITH SOME AREAS
OBSERVING SOME PLEASANT CONDITIONS AS RATHER LIGHT FLOW REMAINS IN
PLACE. EXPECT THIS LOW CLOUD SHIELD TO CONTINUE TO ERODE WITH TIME
LATE THIS AFTERNOON AND EARLY EVENING BUT WITH SOME MID AND HIGH
LEVEL CLOUD COVER TO PUSH OVERHEAD. THIS IN ITSELF SHOULD PROVIDE
PARTLY CLOUDY SKIES FOR TONIGHT...BUT WITH PRECIP CHANCES LATER
TONIGHT TO POSSIBLY BRING MORE CLOUDY CONDITIONS MORE TOWARDS
EARLY SUNDAY MORNING.
LATEST GUIDANCE CONTINUES TO INDICATE SHOWERS AND THUNDERSTORMS
DEVELOPING TONIGHT ACROSS EASTERN IOWA AND SHIFTING EAST/SOUTHEAST
ACROSS A PORTION OF THE CWA THROUGH SUNDAY MORNING. ALL GUIDANCE
IS INDICATING THIS POSSIBILITY BUT WITH SOME VARIABILITY STILL
REMAINING WITH REGARDS TO EXACT TIMING AND PLACEMENT/TRACK. WITH
BACKING 850MB FLOW...A WARMER AND MORE MOIST AIR MASS LOCATED
ACROSS THE CENTRAL PLAINS WILL ADVECT NORTH/NORTHEAST WITH TIME
TONIGHT BRINGING HIGHER DEW POINT AIR TO THE REGION. NORTHWEST FLOW
ALOFT WILL STEER A MID LEVEL IMPULSE AND ATTENDANT SURFACE TROUGH
OUT OF THE NORTHERN PLAINS THIS EVENING...AND HELP TO INITIATE
CONVECTION ALONG A LOW LEVEL BAROCLINIC ZONE DRAPED ACROSS THE
REGION. WITH LOW LEVEL FLOW FEEDING HIGHER THETA E AIR OVER THIS
BOUNDARY AND INTO ANY DEVELOPING PRECIP...THIS AREA OF CONVECTION
COULD SEE SOME EXPANSION IN COVERAGE AS IT SHIFTS EAST/SOUTHEAST
THROUGH THE CWA EARLY SUNDAY MORNING. ALTHOUGH...GUIDANCE
CONTINUES TO STRUGGLE WITH EXACT TIMING OF WHEN CONVECTION WILL
DEVELOP AND WHERE THIS DEVELOPING AREA OF PRECIPITATION WILL
PROGRESS THROUGH. DUE TO THIS UNCERTAINTY STILL IN PLACE...HAVE
NOT MADE MANY CHANGES TO THE GOING POP GRIDS FOR TONIGHT KEEPING
HIGH CHANCE POPS FOR MUCH OF THE CWA AFTER THE MIDNIGHT TIME FRAME
THROUGH MID MORNING SUNDAY. THIS IS BASED ON THE LIKELIHOOD THAT
CONVECTION SHOULD BEGIN TO DEVELOP OVER IOWA ONCE WE DECOUPLE AND
THE LLJ RAMPS UP...WHICH SHOULD BE AROUND THE 3Z-6Z TIME FRAME.
SOME HI RES DATA IS SHOWING THE POSSIBILITY OF AN MCS DEVELOPING
AND QUICKLY SHIFTING THROUGH THE REGION SUNDAY MORNING. HAVE NOT
COMPLETELY THROWN THIS OUT AS A POSSIBILITY...WITH DECENT LOW
LEVEL SHEAR TO BE PRESENT ACROSS THE REGION. A LIMITING FACTOR
WILL BE THE AMOUNT OF INSTABILITY PRESENT OVER NORTHERN ILLINOIS
AND NORTHWEST...WHICH AM CURRENTLY LEANING MORE ON THE SREF MUCAPE
OUTPUT WHICH IS SHOWING WEAKER INSTABILITY PRESENT BY EARLY SUNDAY
MORNING LIMITING MORE ROBUST CONVECTION...WITH OTHER GUIDANCE OF
COURSE ALSO VARYING TO THIS AMOUNT. SO WITH ANY PRECIP WHICH MOVES
THROUGH THE AREA LATE TONIGHT AND EARLY SUNDAY MORNING...A MORE
LIKELY SCENARIO WILL BE FOR THIS TO BE AN UNORGANIZED AREA OF
SHOWERS AND ELEVATED THUNDERSTORMS WITH LITTLE CHANCES FOR SEVERE
WEATHER...HAIL/WIND. ONLY AN ISOLATED THREAT OF HAIL COULD BE
OBSERVED MAINLY FOR THE WESTERN CWA WHERE BETTER INSTABILITY AND
STRONGER EFFECTIVE BULK SHEAR WILL RESIDE. EVEN IF A MORE
ORGANIZED MCS COULD DEVELOP...WOULD EXPECT IT TO FOLLOW THE HIGHER
SURFACE DEW POINT AIR AND BETTER INSTABILITY WHICH WOULD MORE THAN
LIKELY BE SITUATED TO THE SOUTH OF THE CWA. THUS...ONCE AGAIN
KEEPING ANY THREAT FOR SEVERE WEATHER JUST OUTSIDE OF THE CWA.
THIS SITUATION WARRANTS CONTINUED MONITORING...AND WILL MAINTAIN A
MENTION FOR THE CHANCES FOR THUNDERSTORMS TONIGHT IN THE HWO.
ANY LINGERING SHOWERS/THUNDERSTORMS SHOULD EXIT THE CWA BY MID DAY
WITH PARTLY CLOUDY TO SUNNY CONDITIONS EXPECTED THROUGH THE
AFTERNOON. THE EXTENT OF THE MORNINGS PRECIP WILL DEFINITELY PLAY
A KEY ROLE WITH MAX TEMPS ON SUNDAY WITH PERSISTENT WAA ADVECTING
A WARMER AIR MASS OVERHEAD. AS SURFACE WARM FRONT TRIES TO LIFT
NORTHEAST ACROSS THE CWA DURING THE DAY SUNDAY...IT WILL ACTUALLY
BEGIN TO RETREAT AS A COLD FRONT WITH COOLER LOW LEVEL AIR WORKING
ITS WAY BACK WEST ACROSS THE CWA LATE IN THE AFTERNOON AND EARLY
EVENING. SO OUTSIDE OF PRECIP TRENDS POSSIBLY AFFECTING TEMP
TRENDS SUNDAY...PLACEMENT OF THIS BOUNDARY AND MOVEMENT WILL BE
KEY IN DEFINING MAX TEMPS FOR SUNDAY. DID BRING DOWN TEMPS A TAD
FROM GOING FORECAST BUT HAVE KEPT THE WEST/SOUTHWEST CWA WARMER
THAN THE EAST WITH AREAS STILL TO POSSIBLY REACH THE 80 MARK...AND
AREAS ACROSS THE EASTERN CWA TO REACH THE LOWER 70S WITH 60S
EXPECTED FOR AREAS NEAR THE LAKE. HAVE ADDED SLIGHT CHANCE POPS
FOR THE SOUTHEAST PORTION OF THE CWA FOR SUNDAY AFTERNOON WHERE
BETTER FOCUS AND UPPER LEVEL SUPPORT COULD PROVIDE FOR DEVELOPMENT
OF THUNDERSTORMS.
STRONG UPPER LEVEL RIDGING WILL OCCUR ON MONDAY WITH MID AND UPPER
LEVEL FLOW BECOMING RATHER WEAK. THIS WEAK FLOW COINCIDING WITH A
FORECASTED CLOSED UPPER LEVEL LOW TRACKING THROUGH THE SOUTHERN US
WILL PROVIDE A TRICKY FORECAST THROUGH THE REMAINDER OF THE WEEK
WITH THE ANTICIPATION FOR GUIDANCE TO CONTINUE TO STRUGGLE WITH
PLACEMENT OF LOW LEVEL FEATURES AND INEVITABLE PRECIP.
ALTHOUGH...THERE DOES APPEAR TO BE BETTER CHANCES FOR OBSERVING
CONVECTION MONDAY NIGHT. BETTER FORCING AS WELL AS INSTABILITY
LOOK TO BE IN PLACE FOR THE DEVELOPMENT OF POSSIBLY MORE ORGANIZED
CONVECTION...WITH CURRENT GUIDANCE INDICATING BETTER CHANCES
RESIDING ACROSS NORTHERN ILLINOIS INTO EARLY TUESDAY MORNING. HAVE
NOT GONE OVERLY EXCITED WITH POPS DURING THIS TIME FRAME AS THE
ECMWF REMAINS THE OUTLIER KEEPING A SURFACE LOW AND FORCING/PRECIP
OFF TO THE WEST FOR MOST OF MONDAY AND MONDAY NIGHT. IF THIS WERE
TO COME INTO FRUITION...THAN DRIER CONDITIONS WOULD BE OBSERVED
MONDAY NIGHT WITH PRECIP DELAYED UNTIL TUESDAY.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* LIGHT EAST WINDS BECOMING SOUTH-SOUTHEAST THIS EVENING.
* POTENTIAL FOR THUNDERSTORMS LATE TONIGHT INTO EARLY SUNDAY
MORNING.
* WINDS SHIFTING NORTHEAST 10-15 KT BY LATE SUNDAY MORNING.
* POTENTIAL FOR A PERIOD OF MVFR CEILINGS AROUND 1500 FT BEHIND
WIND SHIFT AND LASTING INTO MID AFTERNOON BEFORE SCATTERING.
RATZER
//DISCUSSION...UPDATED 00Z...
MAIN CONCERNS WITH 00Z TAFS ARE POTENTIAL FOR TSRA LATE TONIGHT
INTO EARLY SUNDAY...AS WELL AS THE POTENTIAL FOR A PERIOD OF MVFR
CEILINGS DURING THE DAY SUNDAY AS WINDS TURN NORTHEAST OFF THE
LAKE.
HIGH PRESSURE WAS CENTERED OVER THE CENTRAL GREAT LAKES EARLY THIS
EVENING...WHILE A WEAK AREA OF LOW PRESSURE WAS NOTED OVER THE
MID-MISSOURI RIVER VALLEY NORTH OF OMAHA. THIS LOW WILL WEAKEN
WHILE MOVING EAST ACROSS NORTHERN ILLINOIS BY SUNDAY MORNING. AS
THE LOW ADVANCES...WARM MOIST AND UNSTABLE AIR WILL BE FORCED
OVER A WARM FRONT EXTENDING FROM SOUTHEAST IOWA INTO CENTRAL
ILLINOIS. FORECAST SOUNDINGS DEPICT CONSIDERABLE ELEVATED
INSTABILITY TO BE IN PLACE ACROSS EASTERN IOWA AND NORTHERN
IL...WHICH COMBINED WITH A 35 KT WEST-SOUTHWEST LOW LEVEL JET AND
A SMALL AMPLITUDE SHORT WAVE MOVING FROM IA/MN INTO IL BY 12Z
SUNDAY SHOULD ALLOW FOR THUNDERSTORM DEVELOPMENT. HIGH-RES MODELS
INDICATE CONVECTIVE INITIATION WILL TAKE PLACE OVER CENTRAL-EASTERN
IA THIS EVENING...WITH ELEVATED STORMS THEN SPREADING EAST
INTO NORTHERN AND CENTRAL IL AROUND/AFTER MIDNIGHT. WHILE THE
OVERALL POTENTIAL FOR THUNDERSTORM DEVELOPMENT APPEARS FAIRLY
HIGH...THE MAIN QUESTION IS WHETHER THEY WILL DIRECTLY IMPACT THE
TERMINALS. THE COMBINATION OF THE LOW LEVEL JET VEERING WEST
OVERNIGHT AND THE NORTHWEST TO SOUTHEAST ORIENTATION OF THE LARGER
SCALE THERMAL FIELD SUGGESTS THAT STORMS MAY SCOOT JUST SOUTH OF
RFD-ORD-GYY. THUS OVERALL CONFIDENCE IS FAIRLY HIGH THAT STORMS
WILL DEVELOP AND BE CLOSE TO THE TERMINAL/TRACON AIRSPACE...BUT
LOW THAT THEY WILL MOVE OVER ANY PARTICULAR TERMINAL. WILL HAVE TO
WATCH TO SEE WHERE INITIATION OCCURS TO OUR WEST THIS EVENING TO
GET A BETTER HANDLE ON TRENDS FARTHER TO THE EAST LATE TONIGHT.
ONCE SHOWERS/THUNDERSTORMS MOVE EAST WITH MID-LEVEL AND SURFACE
WAVES SUNDAY MORNING...CONCERNS SHIFT TO POTENTIAL FOR MVFR
CEILINGS AS LOW LEVEL WINDS SHIFT TO THE NORTHEAST WITH A
REINFORCING COOL FRONT. FORECAST SOUNDINGS COOL/SATURATE THE
SHALLOW BOUNDARY LAYER WITH CLOUD BASES EXPECTED TO BE AROUND THE
1500 FT LEVEL...WITH DRYING/SCATTERING INDICATED BY MID/LATE
AFTERNOON.
WINDS...LIGHT EAST-SOUTHEAST WINDS TO BECOME SOUTH OVERNIGHT.
WINDS MAY BECOME LIGHT/VARIABLE FOR A TIME SUNDAY MORNING IN
VICINITY OF THE SURFACE LOW PRESSURE WAVE...THEN SHOULD SHIFT TO
THE NORTHEAST WITH GUSTS AROUND 15 KTS AS FRONT SAGS THROUGH AREA
BY MID/LATE MORNING.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH CONFIDENCE IN WIND TRENDS THROUGH TONIGHT.
* MEDIUM-HIGH CONFIDENCE IN TSRA DEVELOPMENT TONIGHT...BUT LOW
CONFIDENCE ON DIRECT IMPACT TO TERMINALS AT THIS TIME.
* MEDIUM CONFIDENCE IN CEILING TRENDS SUNDAY.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR WITH CHANCE TSRA MONDAY NIGHT.
TUESDAY...VFR WITH CHANCE SHRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
RATZER
&&
.MARINE...
115 PM CDT
WINDS WILL TURN SOUTHERLY AND GRADUALLY INCREASE ACROSS LAKE MI
TONIGHT AS HIGH PRESSURE MOVES EAST FROM THE CENTRAL GREAT LAKES.
LOW PRESSURE WILL EVOLVE EASTWARD ACROSS THE LAKE ON SUNDAY MORNING.
AN ASSOCIATED COLD FRONT WILL SLIP SOUTH AS THIS OCCURS...TURNING
WINDS NORTHERLY ACROSS THE LAKE. THIS FRONT WILL LIKELY MOVE ACROSS
THE NEARSHORE AREAS OF IL AND IN DURING THE EARLY TO MID AFTERNOON
ON SUNDAY. HIGH PRESSURE WILL BRIEFLY PREVAIL ON SUNDAY NIGHT BEFORE
ANOTHER LOW MOVES EAST ACROSS IOWA INTO NORTHERN ILLINOIS. WINDS ARE
EXPECTED TO TURN BACK SOUTHEAST AHEAD OF THIS FEATURE ON MONDAY
AFTERNOON...WITH SOME GUSTS UP TO 25 KT...INCLUDING POSSIBLY IN THE
ILLINOIS NEAR SHORE AREAS. BEHIND THE LOW PASSAGE LATE MONDAY NIGHT
INTO EARLY TUESDAY...THE WINDS WILL ONCE AGAIN SWING BACK NORTHERLY.
HIGH PRESSURE IS THEN FORECAST TO ENCOMPASS MUCH OF THE LAKE
WEDNESDAY THROUGH FRIDAY...THOUGH CONFIDENCE IN THIS IS FAIRLY LOW
DUE TO A CLOSED UPPER LOW IN THE CENTRAL PLAINS WHICH COULD MEANDER
CLOSE ENOUGH TO CAUSE SLIGHTLY STRONGER WINDS. OVERALL AT THIS
TIME...NO LONG-LIVED GUSTY OR HIGH WAVE PERIODS ARE EXPECTED IN
THE NEXT WEEK.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1013 PM EDT SAT MAR 31 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...A WEAK FRONTAL SYSTEM MOVING THROUGH COULD BRING
CHANCES FOR THUNDERSTORMS ACROSS THE AREA LATE TONIGHT INTO SUNDAY.
BY SUNDAY NIGHT UPPER RIDGING SHOULD REBUILD AND DRY THE WEATHER
OUT THROUGH MONDAY...BUT BY MONDAY NIGHT ANOTHER FRONTAL SYSTEM
WILL APPROACH AND STALL OUT AND BRING THUNDERSTORM CHANCES FOR
MONDAY NIGHT THROUGH THURSDAY. MORE UPPER RIDGING WILL DRY THINGS
OUT FOR THE WEEKEND.
&&
.NEAR TERM /OVERNIGHT/...
LARGE AREA OF LOW STRATUS HAS FINALLY SHIFTED EAST WITH ONLY FAR
NORTHEASTERN COUNTIES STILL UNDERNEATH THE DECK. REMAINDER OF THE
FORECAST AREA HAD BECOME PARTLY CLOUDY WITH MID AND HIGH LEVEL
CLOUDS DRIFTING ACROSS THE REGION. QUITE A RANGE OF TEMPERATURES
EXISTED ACROSS THE FORECAST AREA AS OF 00Z...FROM MID 40S OVER THE
NORTHEAST WHERE SKIES HAD BEEN CLOUDY ALL DAY TO MID 60S IN THE
LOWER WABASH VALLEY.
FOCUS FOR THE OVERNIGHT IS POTENTIAL FOR CONVECTION TO IMPACT
WESTERN COUNTIES PRIOR TO DAYBREAK. SHORT RANGE MODEL GUIDANCE
CONTINUING TO ADVERTISE DEVELOPMENT OF SCATTERED CONVECTION OVER
EASTERN IOWA/WESTERN ILLINOIS SHORTLY AFTER MIDNIGHT AS AN UPPER
LEVEL DISTURBANCE MOVES INTO THE REGION. PRESENCE OF A 35KT LOW
LEVEL JET AND AXIS OF ELEVATED INSTABILITY SHOULD FURTHER
CONTRIBUTE TO CONVECTIVE DEVELOPMENT IN THESE AREAS. STEERING FLOW
ALOFT WOULD SUGGEST THAT CONVECTION WILL MOVE SOUTHEAST AND
POTENTIALLY MIGRATE INTO THE NORTHERN WABASH VALLEY LATE TONIGHT.
HAVE CHOSEN TO EXPAND LOW CHANCE POPS TO ENCOMPASS PORTIONS OF THE
FORECAST AREA WEST OF A KOKOMO TO INDY METRO TO TERRE HAUTE LINE
BETWEEN 09-12Z. HRRR GUIDANCE SUGGESTIVE OF LEADING EDGE OF
CONVECTION ARRIVING INTO THESE AREAS SHORTLY BEFORE DAYBREAK.
WHILE STORMS SHOULD BE WEAKENING BY THE TIME THEY ARRIVE IN
CENTRAL INDIANA AS THE ENVIRONMENT WILL BE LESS FAVORABLE...
POTENTIAL FOR STRONGER CELLS TO PRODUCE SMALL HAIL. WILL CONTINUE
TO HIGHLIGHT IN THE HWO.
LOWERED TEMPS A DEGREE OR TWO OVERNIGHT BASED ON CURRENT OBS...AND
ADJUSTED TIMING AS LOWS LIKELY TO BOTTOM OUT BETWEEN 06 AND 08Z
BEFORE ANY STORMS ARRIVE.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
MODELS ARE IN DECENT AGREEMENT ON THE SHORT TERM SO WILL USE A
CONSENSUS GENERALLY...BUT THOUGHT EARLY ON THE NAM WAS A LITTLE
OVERZEALOUS IN POPS AND PRECIP ARRIVAL WITH THE SUNDAY SYSTEM SO
THERE WILL LEAN TOWARD THE GFS/ECMWF/SREFS. COULD HAVE AN MCS
ARRIVING IN THE NORTHWEST TO START OUT SUNDAY. VERY WEAK UPPER
FORCING WITH A LITTLE SHORTWAVE MOVING THROUGH BUT ISENTROPIC LIFT
SHOULD BE GOING THROUGH THE DAY ON SUNDAY. INSTABILITY WILL INCREASE
THROUGH THE DAY SO THAT MIXED LAYER CAPES OF 1000 TO 1500 OR SO WILL
BE IN PLACE ACROSS THE EAST BY THE AFTERNOON. MARGINAL SHEAR /BOTH
DIRECTIONAL AND SPEED/ WILL BE AVAILABLE AS WELL DURING THE
AFTERNOON...AND THUS THE INCLUSION OF A SLIGHT RISK FOR SEVERE
WEATHER ACROSS MUCH OF THE EASTERN COUNTIES FOR THAT TIME. ALSO HAVE
MID LEVEL LAPSE RATES AROUND 7-8C SO EXPECT THE MAIN THREAT TO BE
LARGE HAIL.
LEFT A SLIGHT CHANCE IN THE FAR EAST THROUGH 3Z AS SYSTEM IS MOVING
OUT OF THE AREA. UPPER RIDGING BUILDS BACK IN AND KEPT POPS OUT
THROUGH MONDAY. BY MONDAY NIGHT ANOTHER FRONTAL SYSTEM MOVES IN TO
NORTHERN ILLINOIS AND POSSIBLY NORTHERN INDIANA. THIS SURFACE LOW
AND ISENTROPIC LIFT WILL SERVE AS THE MAIN FORCING MECHANISMS
WITHOUT MUCH IN THE WAY OF UPPER FORCING AVAILABLE. WILL HAVE A
CHANCE FOR THUNDERSTORMS MONDAY NIGHT AND INTO TUESDAY WITH
THIS...WITH HIGHER CHANCES ON TUESDAY WITH THE LOW PASSING OVER THE
AREA.
FOR HIGH TEMPERATURES GENERALLY STUCK TOWARD THE WARMER END OF THE
GUIDANCE ENVELOPE BASED ON RECENT VERIFICATION...AND COULD SEE A
DECENT GRADIENT ACROSS THE AREA ON TUESDAY. FOR LOWS WENT A BIT
WARMER THAN A CONSENSUS BASED ON EXPECTED CLOUD COVER AND FOR MONDAY
NIGHT STUCK NEAR THE WET BULB TEMPERATURES WITH POTENTIAL FOR RAIN.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ENSEMBLES IN GENERAL AGREEMENT IN BRINGING A SYSTEM THAT IS PROGGED
TO BE MOVING INTO THE WEST COAST SUNDAY ACROSS THE LOCAL AREA AROUND
THE MIDDLE OF NEXT WEEK. ENSEMBLE TREND HAS BEEN TOWARDS CUTTING
THIS SYSTEM OFF FROM THE MAIN WESTERLIES...AND TODAY THE MAJORITY OF
THE ENSEMBLES POINT IN THIS DIRECTION...WITH THE EFFECTS OF THE
CUTOFF AFFECTING THE AREA INTO THURSDAY. WILL GO WITH CHANCE POPS ON
WEDNESDAY AND THURSDAY OVER MAINLY THE SOUTHERN ZONES...WHICH WILL
BE CLOSER TO CUTOFF LOW. WILL CONTINUE WITH A DRY FORECAST FRIDAY
AND SATURDAY AT THIS TIME WITH UPPER RIDGING MOVING THROUGH...
ALTHOUGH SOME ENSEMBLES BRING A PRECIPITATION THREAT BACK INTO THE
AREA BY NEXT SATURDAY. MAY NEED TO ADD POPS TO NEXT WEEKEND AT A
LATER TIME IF FUTURE TRENDS POINT IN THAT DIRECTION.
&&
.AVIATION /DISCUSSION FOR THE 010230Z TAF UPDATE/...
KIND VISIBILITY HAS DIPPED INTO MVFR CATEGORY AS OF 02Z. THIS SHOULD
CONTINUE INTO THE OVERNIGHT...BUT DO NOT EXPECT MUCH WORSENING OF
CONDITIONS GIVEN THICKENING CLOUD COVER. CONVECTION IS DEVELOPING
ACROSS IOWA AT THE MOMENT...AND THIS CONVECTION SHOULD EVENTUALLY
SLIDE SOUTHEAST TOWARD THE SITE. FOR NOW WILL CONTINUE WITH CB
MENTION AROUND 10Z AND WILL CONTINUE TO MONITOR.
PREVIOUS DISCUSSION FOLLOWS...
VFR EXPECTED INTO THE OVERNIGHT...BUT A POSSIBLE THUNDERSTORM
COMPLEX LATER TONIGHT COULD BRING MVFR CONDITIONS. THERE IS ALSO A
POSSIBILITY OF MVFR FOG OVERNIGHT. VFR CONDITIONS ARE EXPECTED FOR
MUCH OF SUNDAY.
ONLY MID AND HIGH CLOUDS ARE EXPECTED FOR THE FIRST SEVERAL HOURS OF
THE TAF PERIOD. MODELS ARE HINTING AT A THUNDERSTORM COMPLEX
DEVELOPING IN ILLINOIS AFTER 06Z...WITH THE COMPLEX MOVING SOUTHEAST
AFTERWARD. BASED ON MODEL AGREEMENT HAVE ADDED CB MENTION AFTER 09Z
AND CONTINUING THROUGH 15Z. CONFIDENCE IS MODERATE HERE. IF TSRA AND
CLOUDS DO NOT DEVELOP...MVFR FOG MAY FORM.
KBMG LOOKS TO HAVE THE LOWEST CHANCE FOR TSRA AT THE MOMENT...SO
LEFT MENTION OUT THERE. WITH THE LESSER CHANCE FOR CLOUD COVER FROM
TSRA...EXPECT MVFR FOG TO DEVELOP AT KBMG. CONFIDENCE IS LOW IN THIS
SOLUTION.
AFTER TSRA COMPLEX MOVES OUT OF THE AREA ON SUNDAY...EXPECT SCT-BKN
CU. HAVE INCLUDED A BKN060 LAYER FOR MUCH OF THE DAY TO SHOW
LEFTOVER CLOUDS FROM TSRA AND THEN THE BKN CU DECK.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...RYAN
SHORT TERM...CP
LONG TERM....JAS
AVIATION...50
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
849 PM EDT SAT MAR 31 2012
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...A WEAK FRONTAL SYSTEM MOVING THROUGH COULD BRING
CHANCES FOR THUNDERSTORMS ACROSS THE AREA LATE TONIGHT INTO SUNDAY.
BY SUNDAY NIGHT UPPER RIDGING SHOULD REBUILD AND DRY THE WEATHER
OUT THROUGH MONDAY...BUT BY MONDAY NIGHT ANOTHER FRONTAL SYSTEM
WILL APPROACH AND STALL OUT AND BRING THUNDERSTORM CHANCES FOR
MONDAY NIGHT THROUGH THURSDAY. MORE UPPER RIDGING WILL DRY THINGS
OUT FOR THE WEEKEND.
&&
.NEAR TERM /OVERNIGHT/...
LARGE AREA OF LOW STRATUS HAS FINALLY SHIFTED EAST WITH ONLY FAR
NORTHEASTERN COUNTIES STILL UNDERNEATH THE DECK. REMAINDER OF THE
FORECAST AREA HAD BECOME PARTLY CLOUDY WITH MID AND HIGH LEVEL
CLOUDS DRIFTING ACROSS THE REGION. QUITE A RANGE OF TEMPERATURES
EXISTED ACROSS THE FORECAST AREA AS OF 00Z...FROM MID 40S OVER THE
NORTHEAST WHERE SKIES HAD BEEN CLOUDY ALL DAY TO MID 60S IN THE
LOWER WABASH VALLEY.
FOCUS FOR THE OVERNIGHT IS POTENTIAL FOR CONVECTION TO IMPACT
WESTERN COUNTIES PRIOR TO DAYBREAK. SHORT RANGE MODEL GUIDANCE
CONTINUING TO ADVERTISE DEVELOPMENT OF SCATTERED CONVECTION OVER
EASTERN IOWA/WESTERN ILLINOIS SHORTLY AFTER MIDNIGHT AS AN UPPER
LEVEL DISTURBANCE MOVES INTO THE REGION. PRESENCE OF A 35KT LOW
LEVEL JET AND AXIS OF ELEVATED INSTABILITY SHOULD FURTHER
CONTRIBUTE TO CONVECTIVE DEVELOPMENT IN THESE AREAS. STEERING FLOW
ALOFT WOULD SUGGEST THAT CONVECTION WILL MOVE SOUTHEAST AND
POTENTIALLY MIGRATE INTO THE NORTHERN WABASH VALLEY LATE TONIGHT.
HAVE CHOSEN TO EXPAND LOW CHANCE POPS TO ENCOMPASS PORTIONS OF THE
FORECAST AREA WEST OF A KOKOMO TO INDY METRO TO TERRE HAUTE LINE
BETWEEN 09-12Z. HRRR GUIDANCE SUGGESTIVE OF LEADING EDGE OF
CONVECTION ARRIVING INTO THESE AREAS SHORTLY BEFORE DAYBREAK.
WHILE STORMS SHOULD BE WEAKENING BY THE TIME THEY ARRIVE IN
CENTRAL INDIANA AS THE ENVIRONMENT WILL BE LESS FAVORABLE...
POTENTIAL FOR STRONGER CELLS TO PRODUCE SMALL HAIL. WILL CONTINUE
TO HIGHLIGHT IN THE HWO.
LOWERED TEMPS A DEGREE OR TWO OVERNIGHT BASED ON CURRENT OBS...AND
ADJUSTED TIMING AS LOWS LIKELY TO BOTTOM OUT BETWEEN 06 AND 08Z
BEFORE ANY STORMS ARRIVE.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
MODELS ARE IN DECENT AGREEMENT ON THE SHORT TERM SO WILL USE A
CONSENSUS GENERALLY...BUT THOUGHT EARLY ON THE NAM WAS A LITTLE
OVERZEALOUS IN POPS AND PRECIP ARRIVAL WITH THE SUNDAY SYSTEM SO
THERE WILL LEAN TOWARD THE GFS/ECMWF/SREFS. COULD HAVE AN MCS
ARRIVING IN THE NORTHWEST TO START OUT SUNDAY. VERY WEAK UPPER
FORCING WITH A LITTLE SHORTWAVE MOVING THROUGH BUT ISENTROPIC LIFT
SHOULD BE GOING THROUGH THE DAY ON SUNDAY. INSTABILITY WILL INCREASE
THROUGH THE DAY SO THAT MIXED LAYER CAPES OF 1000 TO 1500 OR SO WILL
BE IN PLACE ACROSS THE EAST BY THE AFTERNOON. MARGINAL SHEAR /BOTH
DIRECTIONAL AND SPEED/ WILL BE AVAILABLE AS WELL DURING THE
AFTERNOON...AND THUS THE INCLUSION OF A SLIGHT RISK FOR SEVERE
WEATHER ACROSS MUCH OF THE EASTERN COUNTIES FOR THAT TIME. ALSO HAVE
MID LEVEL LAPSE RATES AROUND 7-8C SO EXPECT THE MAIN THREAT TO BE
LARGE HAIL.
LEFT A SLIGHT CHANCE IN THE FAR EAST THROUGH 3Z AS SYSTEM IS MOVING
OUT OF THE AREA. UPPER RIDGING BUILDS BACK IN AND KEPT POPS OUT
THROUGH MONDAY. BY MONDAY NIGHT ANOTHER FRONTAL SYSTEM MOVES IN TO
NORTHERN ILLINOIS AND POSSIBLY NORTHERN INDIANA. THIS SURFACE LOW
AND ISENTROPIC LIFT WILL SERVE AS THE MAIN FORCING MECHANISMS
WITHOUT MUCH IN THE WAY OF UPPER FORCING AVAILABLE. WILL HAVE A
CHANCE FOR THUNDERSTORMS MONDAY NIGHT AND INTO TUESDAY WITH
THIS...WITH HIGHER CHANCES ON TUESDAY WITH THE LOW PASSING OVER THE
AREA.
FOR HIGH TEMPERATURES GENERALLY STUCK TOWARD THE WARMER END OF THE
GUIDANCE ENVELOPE BASED ON RECENT VERIFICATION...AND COULD SEE A
DECENT GRADIENT ACROSS THE AREA ON TUESDAY. FOR LOWS WENT A BIT
WARMER THAN A CONSENSUS BASED ON EXPECTED CLOUD COVER AND FOR MONDAY
NIGHT STUCK NEAR THE WET BULB TEMPERATURES WITH POTENTIAL FOR RAIN.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ENSEMBLES IN GENERAL AGREEMENT IN BRINGING A SYSTEM THAT IS PROGGED
TO BE MOVING INTO THE WEST COAST SUNDAY ACROSS THE LOCAL AREA AROUND
THE MIDDLE OF NEXT WEEK. ENSEMBLE TREND HAS BEEN TOWARDS CUTTING
THIS SYSTEM OFF FROM THE MAIN WESTERLIES...AND TODAY THE MAJORITY OF
THE ENSEMBLES POINT IN THIS DIRECTION...WITH THE EFFECTS OF THE
CUTOFF AFFECTING THE AREA INTO THURSDAY. WILL GO WITH CHANCE POPS ON
WEDNESDAY AND THURSDAY OVER MAINLY THE SOUTHERN ZONES...WHICH WILL
BE CLOSER TO CUTOFF LOW. WILL CONTINUE WITH A DRY FORECAST FRIDAY
AND SATURDAY AT THIS TIME WITH UPPER RIDGING MOVING THROUGH...
ALTHOUGH SOME ENSEMBLES BRING A PRECIPITATION THREAT BACK INTO THE
AREA BY NEXT SATURDAY. MAY NEED TO ADD POPS TO NEXT WEEKEND AT A
LATER TIME IF FUTURE TRENDS POINT IN THAT DIRECTION.
&&
.AVIATION /DISCUSSION FOR THE 010000Z TAFS/...
VFR EXPECTED INTO THE OVERNIGHT...BUT A POSSIBLE THUNDERSTORM
COMPLEX LATER TONIGHT COULD BRING MVFR CONDITIONS. THERE IS ALSO A
POSSIBILITY OF MVFR FOG OVERNIGHT. VFR CONDITIONS ARE EXPECTED FOR
MUCH OF SUNDAY.
ONLY MID AND HIGH CLOUDS ARE EXPECTED FOR THE FIRST SEVERAL HOURS OF
THE TAF PERIOD. MODELS ARE HINTING AT A THUNDERSTORM COMPLEX
DEVELOPING IN ILLINOIS AFTER 06Z...WITH THE COMPLEX MOVING SOUTHEAST
AFTERWARD. BASED ON MODEL AGREEMENT HAVE ADDED CB MENTION AFTER 09Z
AND CONTINUING THROUGH 15Z. CONFIDENCE IS MODERATE HERE. IF TSRA AND
CLOUDS DO NOT DEVELOP...MVFR FOG MAY FORM.
KBMG LOOKS TO HAVE THE LOWEST CHANCE FOR TSRA AT THE MOMENT...SO
LEFT MENTION OUT THERE. WITH THE LESSER CHANCE FOR CLOUD COVER FROM
TSRA...EXPECT MVFR FOG TO DEVELOP AT KBMG. CONFIDENCE IS LOW IN THIS
SOLUTION.
AFTER TSRA COMPLEX MOVES OUT OF THE AREA ON SUNDAY...EXPECT SCT-BKN
CU. HAVE INCLUDED A BKN060 LAYER FOR MUCH OF THE DAY TO SHOW
LEFTOVER CLOUDS FROM TSRA AND THEN THE BKN CU DECK.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...RYAN
SHORT TERM...CP
LONG TERM....JAS
AVIATION...50
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
750 PM EDT SAT MAR 31 2012
.AVIATION...
INITIAL AVIATION PROBLEM IS CIGS AT KFWA. SATELLITE SHOWS CLEARING
LINE ON THE EDGE OF KFWA WITH ONLY A SLOW EROSION AS NEXT SYSTEM
DEVELOPS UPSTREAM. EXPECT THESE CLOUDS TO SCATTER SHORTLY GIVEN
PROXIMITY OF CLEARING TO AIRPORT SEEN ON SATELLITE. SHORT RANGE
MODELS STILL HAVING DIFFERENCES RESOLVING EXTENT AND LOCATION OF
CONVECTION FOR LATER TONIGHT INTO SUNDAY. FOR THIS TAF PACKAGE HAVE
OPTED FOR A BLEND OF HRRR AND 4KM WRF-NMM. THESE MODELS INDICATE
CONVECTIVE DEVELOPMENT OVERNIGHT ACROSS IA ALONG WARM FRONT AND MOVE
THIS EAST INTO CENTRAL INDIANA SUNDAY MORNING. TAF SITES REMAIN
NORTH OF BEST LIFT AND MOST PRECIPITATION THOUGH LIGHTER SHOWERS
POSSIBLE AFTER DAYBREAK. FOR NOW ONLY INCLUDED SOME MARGINAL VIS
RESTRICTIONS WITH BR LATE TONIGHT AND OPTED TO KEEP PCPN OUT OF TAFS
FOR NOW. WILL MONITOR UPSTREAM TRENDS FOR CHANGES WITH NEXT PACKAGE.
BACKDOOR COLD FRONT EXPECTED TO DROP SOUTH SUNDAY AFTERNOON WITH
WINDS SHIFTING NORTH AROUND OR AFTER 18Z. SOME SCATTERED LIGHT RAIN
SHOWERS POSSIBLE WITH THETA E GRADIENT AND MODEST LIFT NEAR FRONT.
&&
.SHORT TERM... /TONIGHT THROUGH SUNDAY NIGHT/
CLOUD COVER HAS BEEN EXTREMELY PERSISTENT UNDER STRONG LL INVERSION
IN PLACE ACROSS THE REGION. VIS SATELLITE AND SFC OBS SHOWING
CLEARING LINE ADVANCING NE FROM ILLINOIS TOWARDS THE FORECAST AREA.
DESPITE NE FLOW...DEPTH OF DRY AIR HAS BEEN FAIRLY LIMITED WITH
SUFFICIENT MSTR STILL AROUND TO ALLOW FOR LAKE EFFECT CLOUD BANDS
ACROSS EASTERN MICHIGAN. MODELS CONTINUE TO THIN OUT THE CLOUD DECK
AND BASED ON SFC OBS WITH SLOWLY RISING CIGS THIS TREND SEEMS
REASONABLE. HAVE BACKED OFF ON CLEARING TIMING SOMEWHAT GOING NO
BETTER THAN PARTLY TO MOSTLY CLOUDY.
TONIGHT...WARM FRONT TO THE SW WILL ONLY EDGE NORTHWARD SOMEWHAT.
FLOW OF BETTER LL MSTR AND INCREASING LIFT WILL CONTINUE ACROSS IOWA
WHERE NAM12/SPC 4KM WRF INITIATES CONVECTION AFTER 6Z AND MOVES IT
SE ACROSS CNTRL IL INTO CNTRL IN. LOCAL WRF ALSO DEVELOPS LIMITED
CONVECTION IN EASTERN IOWA BUT CLOSER TO 12Z THEN DROPPING TOWARDS
THE FORECAST AREA DURING THE DAY. REGARDLESS OF MODEL OF
CHOICE...DRY CONDITIONS WOULD APPEAR TO BE IN STORE THROUGH THE
NIGHT SO WILL MAINTAIN THE DRY FORECAST AND LOWS FALLING INTO THE
40S (WARMEST SW).
SUN/SUN NGT...AS NOTED ABOVE...SEVERAL SOLUTIONS IN PLACE REGARDING
DEVELOPMENT OF CONVECTION WITH REMNANTS EITHER TRACKING ACROSS THE
AREA OR COMPLETELY MISSING US. WEAK COLD FRONT WILL BE DROPPING
SOUTH DURING THE DAY WITH AT LEAST SOME INSTABILITY ARRIVING AND 70+
KT MID LEVEL JET DYNAMICS ARRIVING DURING THE AFTERNOON. STAGE WOULD
BE SET FOR CONVECTION TO EITHER EXPAND OR DEVELOP ACROSS THE AREA
DURING THE AFTERNOON. HOWEVER...IF NAM SOLUTION WORKS OUT WITH
FURTHER SW TRACK OF MCS AND CUT OFF OF BETTER MSTR...THEN REGION
WILL BE LACKING BEST COMBINATION OF EVERYTHING RESULTING IN LOW
CHANCES FOR CONVECTION AND MINIMIZED SEVERE THREAT. NEW SWODY2
OUTLOOK PLACED OUR FAR SOUTHERN COUNTIES IN SLGT RISK WITH REMAINDER
OF AREA STILL 5%. MID RANGE CHC POPS IS BEST OPTION FOR THE TIME
BEING THROUGH THE DAY. WILL HOLD OFF ON ANY SVR MENTION IN ZONES AND
MAY BEEF UP WORDING A BIT IN HWO. HIGHS WILL BE HIGHLY DEPENDENT ON
CLOUD COVER...BUT CURRENT FORECAST SEEMS REASONABLE AT THIS POINT
WITH BUST POTENTIAL LOW TO MODERATE.
OTHER THAN A LINGERING SHOWER OR STORM EARLY...DRY CONDITIONS SHOULD
PREVAIL SUN NGT. SURROUNDING OFFICES HAVE REMOVED ALL MENTION OF
PRECIP WHICH SEEMS REASONABLE SO HAVE FOLLOWED SUIT. LOWS WILL DROP
BACK INTO THE UPPER 40S TO UPPER 50S.
&&
.LONG TERM...MONDAY THROUGH SATURDAY
UPPER LEVEL PATTERN SLOW TO EVOLVE FOR MONDAY WITH DIGGING UPPER
TROUGH EXPECTED TO CUT OFF ACROSS THE FOUR CORNERS REGION WHILE A
MORE PROGRESSIVE NORTHERN STREAM TAKES SHAPE ACROSS SOUTHWEST
CANADA. AMPLIFIED UPPER LEVEL RIDGING WILL MAINTAIN ITSELF ACROSS
THE GREAT LAKES REGION ON MONDAY...WITH LOW LEVEL WARM FRONT/LOW
LEVEL JET TO QUICKLY ADVECT A STRONG LOW LEVEL THERMAL RIDGE BACK
INTO THE REGION FOR MONDAY AFTERNOON...AND ESPECIALLY BY EVENING.
850/700 HPA LAPSE RATES WILL REMAIN RELATIVELY WEAK HOWEVER AND WITH
STRONGEST ISENTROPIC LIFT NOT AFFECTING THE AREA UNTIL
EVENING...PROSPECTS FOR ANY SFC BASED OR ELEVATED CONVECTION ARE TOO
LOW FOR INCLUSION IN THE FORECAST MONDAY AFTERNOON. LITTLE IF ANY
CHANGE TO PREVIOUS FORECAST IN REGARDS TO HIGH TEMPERATURES ON
MONDAY WITH ORIENTATION OF WAA/DEPARTING RIDGE AXIS SUPPORTING
WARMEST READINGS SOUTHWEST OF UPPER 70S TO NEAR 80...AND COOLEST
ACROSS THE NORTHEAST IN THE MID TO UPPER 60S.
BY MONDAY EVENING...POSITIVE LOW LEVEL THEATE ADVECTION AND
STEEPENING MID LEVEL LAPSE RATES MAY SUPPORT ANOTHER ROUND OF
SCATTERED ELEVATED SHOWERS/THUNDERSTORMS. THE PROGRESSIVE NORTHERN
STREAM TROUGH TRACKING ACROSS SOUTH CENTRAL CANADA WILL EVENTUALLY
DRIVE A SFC LOW/COLD FRONT SOUTHWARD ACROSS THE AREA ON
TUESDAY...ALTHOUGH A GOOD DEAL OF UNCERTAINTY REMAINS AS TO HOW
QUICKLY THIS BOUNDARY WILL PUSH THROUGH. HAVE UTILIZED A BLEND
BETWEEN GFS AND THE SLIGHTLY SLOWER GEM/ECMWF IDEA FOR FRONTAL
PROGRESSION ON TUESDAY WITH THESE DIFFERENCES STEMMING MAINLY FROM
SUBTLE DIFFERENCES IN TIMING AND AMPLITUDE OF THE NORTHERN STREAM
TROUGH. AFTER POTENTIAL ELEVATED CONVECTION MONDAY NIGHT/TUESDAY
MORNING...ATTENTION WILL SHIFT TO POSSIBLE AFTERNOON REDEVELOPMENT
ALONG AND AHEAD OF THE COLD FRONT...ALTHOUGH TIMING OF THE FRONT MAY
END UP FAVORING FAR SOUTHERN AREAS TUESDAY AFTERNOON/EVENING FOR
BETTER CONVECTIVE POTENTIAL. STRENGTH OF MID/UPPER LEVEL FORCING
ALSO IN QUESTION AS LOCAL AREA BECOMES POSITIONED BETWEEN MORE
PRONOUNCED FORCING FROM SOUTHERN/NORTHERN STREAM. WILL MAINTAIN LOW
TO MID RANGE CHANCE POPS FOR THUNDER TUESDAY WITH FRONT DROPPING
SOUTH OF THE AREA TUESDAY NIGHT.
MEDIUM RANGE MODELS FOR WED-FRI ARE FAIRLY CONSISTENT WITH CONSENSUS
IDEA TO TAKE SOUTHERN STREAM UPPER LEVEL LOW SOUTH OF THE AREA
WEDNESDAY NIGHT INTO THURSDAY WITH BROAD CANADIAN SFC HIGH AND
COOLER AIR BUILDING SOUTHWARD. PREDICTABILITY DWINDLES BY LATE DAY 6
AND 7 WITH A GREAT DEAL OF DETERMINISTIC/ENSEMBLE MODEL SPREADS WITH
PROGRESSION OF NEXT SIGNIFICANT EASTERN PACIFIC TROUGH. FASTER
CLUSTER OF GUIDANCE WOULD SUGGEST LOW POPS ACROSS WESTERN PORTIONS
OF FORECAST AREA TOWARD THE END OF THE PERIOD...BUT WILL MAINTAIN
DRY DAY 7 FORECAST AT THIS TIME WITH ABOVE NORMAL TEMPS CONTINUING.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...FISHER
LONG TERM...MARSILI
AVIATION...LASHLEY
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 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 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 WICHITA KS
708 PM CDT SAT MAR 31 2012
.AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MAIN CONCERN: POTENTIAL FOR IFR/LIFR STRATUS
LEE TROUGH WILL ALLOW LIGHT SOUTH-SOUTHEASTERLY WINDS TO CONTINUE
OVERNIGHT WITH INCREASING BOUNDARY LAYER MOISTURE. THIS SHOULD
RESULT IN IFR (POSSIBLY LIFR) STRATUS DEVELOPMENT OVER MUCH OF THE
AREA DURING THE EARLY AM HOURS SUNDAY. THIS IS SUPPORTED IN THE
NAM...GFS...RUC...AND 3KM HRRR MODELS. FORECAST CONFIDENCE ABOVE
AVERAGE GIVEN THE LOW STRATUS OCCURRENCE IN CENTRAL/SOUTHWEST OK AND
NORTH CENTRAL TEXAS THIS MORNING. THE STRATUS LOOKS TO BURN OFF
TOWARD MIDDAY SUNDAY. BETTER MIXING AND NEAR FULL SUNSHINE SUNDAY
AFTERNOON SHOULD RESULT IN SOUTHERLY GUSTS ~25 KT MOST OF THE
AREA.
JMC
&&
.PREV DISCUSSION... /ISSUED 243 PM CDT SAT MAR 31 2012/
DISCUSSION...
FORECAST CHALLENGES...LOW CLOUD TRENDS TONIGHT/SUNDAY MORNING AND
THEN PRECIP CHANCES/TRENDS EARLY NEXT WEEK.
TONIGHT-MONDAY
LITTLE CHANGE TO THE FORECAST TO CLOSE OUT THE WEEKEND...WITH
THE UNSEASONABLE WARMTH CLOSING IN ON SOME RECORDS. FOR THIS
EVENING...SOUTHEAST KANSAS WILL REMAIN ON EDGE OF WEAKER CAP
WHERE MODERATE INSTABILITY WILL BE PRESENT PRIOR TO DARK. HOWEVER
LACK OF FOCUS/TRIGGER SHOULD PRECLUDE CONVECTION SO WILL KEEP
FORECAST DRY. SOME PATCHY LIGHT FOG WITH PERHAPS BETTER CHANCE FOR
SOME LOW CLOUDS TO DEVELOP AROUND DAWN ACROSS SOUTHERN PORTIONS OF
THE AREA WITH CLOUDS LINGERING INTO MIDDAY FOR AREAS EAST OF THE
TURNPIKE. OTHERWISE...INCREASING SOUTHERLY FLOW/BETTER MIXING INTO
SUNDAY AFTERNOON SHOULD RESULT IN MORE SUNSHINE...WIND AND VERY
WARM MAXS ACROSS THE ENTIRE...GENERALLY IN THE 85 TO 90F RANGE.
THE APPROACHING UPPER TROF WILL MOVE ACROSS THE SOUTHWEST CONUS
SUNDAY NIGHT...BECOMING A CLOSED LOW AS IT MOVES ACROSS THE
SOUTHERN ROCKIES DURING MONDAY. THE INHERITED FORECAST SUPPORTS
THE LATEST MODEL CONSENSUS IN SLOWING THE SURFACE FRONTAL PASSAGE
AND PRECIP/CONVECTIVE CHANCES TO LATER IN THE DAY ON MONDAY. THIS
WILL RESULT IN ONE MORE DAY OF UNSEASONABLY WARM TEMPERATURES
ESPECIALLY FOR LOCATIONS ALONG AND EAST OF THE TURNPIKE.
TUESDAY-WEDNESDAY
A LITTLE BETTER MODEL CONTINUITY EXISTS WITH THE MOVEMENT OF
THE CLOSED UPPER LOW ACROSS MID-AMERICA INTO MID-WEEK...WITH
BEST CHANCE FOR SHOWERS/STORMS ON TUESDAY AND WEDNESDAY.
THURSDAY-SATURDAY
A COUPLE DAYS OF DRY WEATHER EXPECTED IN THE WAKE OF THE
DEPARTING UPPER LOW FOR THURSDAY AND FRIDAY. MEANWHILE UPPER
TROUGHING WILL DEVELOP ACROSS THE WESTERN CONUS WITH A
SIGNIFICANT SHORTWAVE LIFTING NORTHEAST ACROSS THE NORTHERN
PLAINS BY SATURDAY. WHILE CONFIDENCE IS MODEST AT BEST...WILL
SHOW SMALL PRECIP/CONVECTIVE CHANCES ALONG THE ASSOCIATED
SURFACE FRONT FRIDAY NIGHT/SATURDAY.
DARMOFAL
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
FAIRLY QUIET AVIATION FORECAST FOR MOST OF THE PERIOD. FEW-SCT
DIURNAL CUMULUS THIS AFTERNOON AT KICT-KHUT-KCNU WILL BURN OFF BY
00-02Z. OTHERWISE...DIURNAL COOLING IN CONCERT WITH INCREASING
BOUNDARY LAYER MOISTURE MAY PROMOTE A 3-5 HOUR PERIOD OF IFR/LIFR
CIGS FROM 10/11Z THROUGH 14/15Z. THE NAM MODEL MAY BE
OVER-MOISTENING THE BOUNDARY LAYER AS IT OFTEN DOES...HENCE
CONFIDENCE IS LOW ON THIS OCCURRING...SO ONLY HINTED AT IT IN THE
18Z TAFS.
ADK
FIRE WEATHER...
DESPITE UNSEASONBALY WARM TEMPERATURES AND INCREASING WINDS ON
SUNDAY...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 60 87 61 84 / 0 0 0 20
HUTCHINSON 59 89 59 81 / 0 0 0 20
NEWTON 60 87 62 82 / 0 0 0 20
ELDORADO 60 87 63 85 / 0 0 0 20
WINFIELD-KWLD 61 88 63 86 / 0 0 0 20
RUSSELL 59 91 56 75 / 0 0 0 20
GREAT BEND 58 90 55 77 / 0 0 0 20
SALINA 61 90 60 81 / 0 0 0 20
MCPHERSON 60 89 60 81 / 0 0 0 20
COFFEYVILLE 62 88 66 88 / 0 10 10 10
CHANUTE 61 88 65 87 / 0 10 10 10
IOLA 61 88 65 87 / 0 10 10 10
PARSONS-KPPF 61 88 65 88 / 0 10 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
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 PADUCAH KY
630 PM CDT SAT MAR 31 2012
.UPDATE...
UPDATED AVIATION SECTION FOR 00Z TAF ISSUANCE
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 1253 PM CDT SAT MAR 31 2012
AFTER ANY EARLY EVENING CONVECTION DIES DOWN OVER SOUTHEAST
MISSOURI...DRY CONDITIONS SHOULD REMAIN OVER THE WFO PAH FORECAST
AREA TONIGHT THROUGH MONDAY.
IN REVIEWING THE 12Z SUNDAY UPPER AIR ANALYSIS...THERE APPEARED TO
BE A SUBTLE 850-700 MB TROUGH/FRONTAL BOUNDARY EXTENDING FROM
SOUTHEAST IA...THROUGH CENTRAL IL INTO CENTRAL AND SOUTHEAST
INDIANA. WHEN THE LOW LEVEL JET KICKS IN LATER TONIGHT...THE ZONE
WILL LIKELY BE THE FOCUS FOR AN OVERNIGHT MESOSCALE CONVECTIVE
SYSTEM /MCS/. THE LIFT AND INSTABILITY SHOULD REMAIN WELL TO THE
NORTH OF THE WFO PAH FORECAST AREA...AS THE UPPER RIDGE BUILDS IN
FROM THE SOUTHWEST TONIGHT INTO SUNDAY. THEREFORE...ANY MENTION OF
POP/WEATHER REMAINS OUT OF THE FORECAST AT THIS TIME.
FROM EARLIER IN THE WEEK TO TODAY...THE DOMINANCE OF INCREASED
THICKNESSES WITH THE BUILDING RIDGE FROM THE SOUTHWEST /EVIDENT IN
THE SOUTHWEST U.S. IN THE 12Z UPPER AIR ANALYSIS/ HAS REQUIRED
NEARLY DAILY UPWARD ADJUSTMENTS IN THE MAX/MIN TEMPERATURE FORECAST
FOR SUNDAY AND MONDAY. NOW THAT THE PRECIPITATION IS NO LONGER AN
ISSUE FOR MONDAY AFTERNOON...A BROAD INCREASE TEMPERATURES AND
DEWPOINTS /DUE TO THE MOIST SOUTHERLY FLOW UNDER THE SUBSIDENCE
INVERSION/ WILL BE EVEN MORE PRONOUNCED. HEAT INDEX VALUES WILL
NOT VARY MUCH FROM THE ACTUAL TEMPERATURES...BUT THE EARLY SEASON
HEAT MAY BE OF SOME CONCERN FOR THOSE ESPECIALLY SENSITIVE TO THE
WARM TEMPERATURES.
WE WILL LIKELY TIE OR BREAK BOTH THE CURRENT RECORD MAX
TEMPERATURE AND MAXIMUM OVERNIGHT MINIMUM TEMPERATURES FOR APRIL
1ST INTO 2ND.
HERE ARE THE CURRENT RECORDS AT THIS TIME FOR EVANSVILLE AND PADUCAH.
EVANSVILLE INDIANA
APRIL 1ST...RECORD MAX...85 DEGREES SET IN 1940.
APRIL 1ST...RECORD MAX MINIMUM TEMPERATURE...62 DEGREES SET IN 1946.
APRIL 2ST...RECORD MAX...83 DEGREES SET IN 1967.
PADUCAH KENTUCKY
APRIL 1ST...RECORD MAX...86 DEGREES SET IN 1946.
APRIL 1ST...RECORD MAX MINIMUM TEMPERATURE...60 DEGREES SET IN 1988.
APRIL 2ST...RECORD MAX...84 DEGREES SET IN 1946.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 339 PM CDT SAT MAR 31 2012
MAIN ISSUE WITH THE TUE THROUGH THU TIME FRAME LIES WITH YET ANOTHER
IN A SEEMINGLY ENDLESS STRING OF SPLIT FLOW UPPER LOWS THIS SEASON
THAT TRUDGE SLOWLY EAST OUT OF THE FOUR CORNERS AREA AND INTO THE
SOUTHERN PLAINS. OPERATIONAL GFS AND EURO MODELS ARE IN SURPRISING
DECENT AGREEMENT WITH THE PLACEMENT OF THE MID LEVEL CIRCULATION
WEDNESDAY AFTN. HOWEVER...THEY DIVERGE SOMEWHAT FROM THERE WITH THE
OP GFS TAKING MORE OF A NRN ROUTE INTO MO...WHEREAS THE ECMWF DIPS
SE INTO AR. TIMING LOOKS GOOD THOUGH AS FAR AS EASTWARD PROGRESSION
BY THU AFTN.
MEANWHILE...AT THE SFC...ESSENTIALLY A COLD FRONT IS EXPECTED TO
DROP SE INTO THE OHIO VALLEY REGION BY TUE NIGHT AND WED...THEN
REMAIN NEARLY STATIONARY UNTIL THE SLOW MOVING UPPER LOW CAN PASS BY
LATER THU AFTERNOON OR THU NIGHT. THE COMBINATION OF THE MID LEVEL
FORCING/ASCENT GENERATED BY THE UPPER LOW...SFC DEW POINTS NEAR 60
AND THE WEAK LOW LEVEL FORCING ASSOCIATED WITH THE SFC FRONT WILL
LEAD TO SEVERAL PERIODS OF SCATTERED SHOWERS AND THUNDERSTORMS TUE
THROUGH THU. THE UPPER SYSTEM IS NOT NEARLY AS POTENT AS PREVIOUS
SPLIT SRN STREAM UPPER LOWS...AND LOW LEVEL FORCING/CONVERGENCE IS
NOT IMPRESSIVE. THEREFORE...EVEN THOUGH WE WILL HAVE AN EXTENDED
PERIOD OF RAIN/THUNDER CHANCES...WE DO NOT EXPECT EXTENSIVE HEAVY
RAINS OR SEVERE STORMS AT THIS TIME. OF COURSE...MAY BE LOCALLY
HEAVY DOWNPOURS FROM TIME TO TIME IN SOME LOCATIONS...AND CANNOT
RULE OUT A FEW STRONG OR ISOLATED SEVERE STORMS...ESP IF WE CAN GET
SOME DAYTIME HEATING AHEAD OF THE MID LEVEL LOW.
ALL OF THE CLOUDS AND PERIODS OF RAIN SHOULD HELP HOLD TEMPS DOWN
SOME...AND MAY EVEN RETURN TO NEAR NORMAL ONCE THE FRONT PASSES LATE
NEXT WEEK.
&&
.AVIATION...
ISSUED AT 630 PM CDT SAT MAR 31 2012
STILL SOME CONCERN ABOUT THE POTENTIAL REDEVELOPMENT OF FOG AND LOW
STRATUS LATE TONIGHT. THE POTENTIAL APPEARS TO BE MITIGATED BY THE
PRESENCE OF DECENT LOW LEVEL SOUTHWEST WINDS ABOVE THE SURFACE.
HOWEVER...THE 21Z RUC MODEL INDICATED THE PRESENCE OF A VERY SHALLOW
SATURATED LAYER RIGHT NEAR THE SURFACE AFTER 06Z. THE HIGHEST
POTENTIAL FOR IFR CONDITIONS APPEARS TO BE IN THE KEVV/KOWB
AREA...WHERE TEMP/DEW POINT SPREADS WERE SMALLEST AND SURFACE
RELATIVE HUMIDITY WAS HIGHEST TODAY. WHATEVER LOW CLOUDS AND FOG
FORM OVERNIGHT WILL DISSIPATE RATHER QUICKLY AFTER SUNRISE...MAINLY
DUE TO STRENGTHENING SOUTHWEST LOW LEVEL WINDS.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...SMITH
LONG TERM....GM
AVIATION...MY
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
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 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
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 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...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...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 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 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
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
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
NWS WILMINGTON NC
1035 PM EDT SAT MAR 31 2012
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL IMPACT THE AREA THROUGH TONIGHT AS
A COLD FRONT CROSSES THE AREA ...AND THEN MOVES OFF THE COAST.
DRY WEATHER IS EXPECTED SUNDAY AS HIGH PRESSURE PASSES ACROSS THE
REGION. A WEAK COLD FRONT WILL DROP SOUTH THROUGH THE AREA MONDAY.
UNSETTLED CONDITIONS WILL RETURN BY THE MIDDLE OF NEXT WEEK AS A
LOW PRESSURE SYSTEM APPROACHES THE EASTERN CAROLINAS.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1030 PM SATURDAY...LATEST SFC ANALYSIS PLACES THE COLD FRONT
PARTIALLY INTO NC...DROPPING FROM THE NORTH. THE CONVECTION ACROSS
THE NE PORTION OF THE STATE IS BASICALLY ALONG THE COLD FRONT
ITSELF. THE OUTFLOW FROM THIS CONVECTION IS AIDING THE COLD FRONTS
PUSH SOUTHWARD...AND COULD REACH THE NORTHERN PORTIONS OF THE ILM
CWA BY MIDNIGHT THROUGH 1 AM SUNDAY. SLIGHTLY FASTER THAN 1ST
PROGGED WITH HRRR AND AN EARLIER NAM MODEL RUN. HRRR INDICATES 1
MORE POTENTIAL MINI ROUND OF CONVECTION TO PUSH THROUGH IMMEDIATELY
AHEAD OF THE COLD FRONT. WILL CONTINUE WITH LOW CHANCE POPS THROUGH
ROUGHLY 2 AM SUNDAY. LOOKING AT NAM 1K-8H PARTIAL THICKNESS PACKING
AND HRRR HRLY WINDS...THE COLD FRONT WILL DROP NEARLY DUE SOUTH
ACROSS THE FA BETWEEN 1AM AND 7AM SUNDAY. LOOK FOR NW WINDS TO VEER
TO THE N-NE ALONG WITH A MINI CAA SURGE THAT WILL ONLY LAST THRU
MIDDAY SUNDAY B4 SHUTTING OFF. WITH THREAT OF PCPN INTO THE EARLY AM
HRS OF SUNDAY AND CLOUDS STICKING AROUND FOR MUCH OF THE REMAINDER
OF THE NIGHT. HAVE KEPT FOG DEVELOPMENT AT A MINIMUM WITH AN
INCREASED POTENTIAL FOR A BRIEF STRATUS DECK UP THRU 1-2 HRS AFTER
DAYBREAK. HAVE KEPT OVERNIGHT LOWS STABLE AFTER INCREASING A DEGREE
OR 3 EARLIER...ESPECIALLY THE SOUTHERNMOST LOCALES WHERE THE FROPA
WILL COINCIDE WITH DAYBREAK.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 300 PM SATURDAY...COLD FRONT POSITIONED JUST OFFSHORE AT THE
START OF THE PERIOD. NVA AND SOME DRY AIR ADVECTION THROUGH THE MID
LEVELS OF THE COLUMN KEEP SUNDAY SUNNY...BUT TEMPS WILL WARM WELL
INTO THE 70S WITH LACK OF ANY CAA AND ENHANCED RIDGING ALOFT. TEMPS
REMAIN WELL ABOVE CLIMO SUNDAY NIGHT AS GRADIENT TIGHTENS BETWEEN
RIDGE OF HIGH PRESSURE AND ADVANCING COLD FRONT FROM THE NORTH. THIS
COMBINED WITH SOME INCREASING MID-LEVEL CLOUDINESS WILL KEEPS MINS
IN THE MID/UPPER 50S.
SHORTWAVE TROUGH ROTATING DOWN FROM NEW ENGLAND SPAWNS A SURFACE LOW
IN THE MID ATLANTIC WHICH TRIES TO DRIVE A COLD FRONT THROUGH EARLY
MONDAY. WITH N/NW FLOW ALOFT...ANTICIPATE THIS FRONT TO WORK ALL THE
WAY SOUTH THROUGH THE CWA BY AFTN. DURING FROPA...MID LEVEL LAPSE
RATES STEEPEN AND FORECAST SOUNDINGS DEPICT INCREASING SATURATION IN
THE 800-500MB LAYER. FORCING IS NOT STRONG...BUT WILL ADD A SCHC POP
FOR TSTMS MONDAY...DECREASING FROM NORTH TO SOUTH THROUGH THE AFTN.
THIS FRONT WILL MAKE FOR A DIFFICULT TEMP FORECAST MONDAY AS
WELL...WITH 850MB TEMPS POSSIBLY FALLING THROUGH PEAK
HEATING...ESPECIALLY ACROSS NE ZONES. EXPECT TEMPS TO RANGE FROM THE
UPPER 80S IN THE TYPICAL WARM PEE DEE LOCATIONS...TO AROUND 80 IN
THE NORTHEAST ZONES...EVEN WITH FAVORED DOWNSLOPE COMPRESSIONAL
WARMING OCCURRING.
FRONT STALLS SOUTH OF THE AREA AND SOME ISENTROPIC LIFT BEGINS LATE
MONDAY NIGHT...ESPECIALLY ACROSS THE SOUTHERN PORTIONS OF THE CWA.
WILL RAMP POP BACK UP TO SCHC ACROSS THE SOUTH. MINS WILL FALL TO
AROUND 50 ACROSS THE NORTHEAST CWA...TO NEAR 60 IN THE SOUTH.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 300 PM SATURDAY...AMPLITUDE WILL ONCE AGAIN BE
THE NAME OF THE GAME FOR THE EXTENDED AS A LARGE MID LEVEL CYCLONE
WILL BE WOBBLING OVER THE FOUR CORNERS REGION INITIALLY WITH RIDGING
JUST WEST OF OUR REGION. AT THE SURFACE A FRONT WILL RESIDE JUST TO
THE SOUTHWEST BEFORE GETTING WASHED OUT WEDNESDAY. A BACKDOOR FRONT
WILL MOVE ACROSS THURSDAY INCREASING THE WEAK FORCING MECHANISMS IN
PLACE...THIS AS THE MID LEVEL PATTERN AMPLIFIES SLIGHTLY. FINALLY
LATE THURSDAY AND FRIDAY THE MAIN SYSTEM ASSOCIATED WITH THE
PREVIOUSLY MENTIONED MID LEVEL LOW MOVES ACROSS. BOTTOM LINE...I
HAVE INCREASED POPS FROM TUESDAY THROUGH THURSDAY INCREMENTALLY
BASED ON A DIURNAL SCENARIO. THE NEW DAY...SATURDAY LOOKS DRY AT
THIS POINT BUT THE INHERIT DIFFICULTIES OF FORECASTING A CLOSED
SYSTEM THIS FAR OUT IN TIME MAKE FOR A LOW CONFIDENCE DRY
FORECAST.
REGARDING TEMPERATURES...HAVE INCREASED TEMPERATURES A BIT ACROSS
THE BOARD TO MATCH GUIDANCE AND ADJACENT OFFICES BUT OVERALL TRENDS
OF SLIGHTLY ABOVE EARLY TREND TO NEAR NORMAL LATE REMAIN INTACT.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 00Z...LINGERING CONVECTION WILL AFFECT MYR FOR THE FIRST HOUR
OR SO...THEN MOVE OFFSHORE WITH THE PRE FRONTAL TROUGH. AFTER
03Z...A SECONDARY BATCH OF CONVECTION IS POSSIBLE WITH THE ACTUAL
FRONT. THIS PRECIP WILL BE WANING AS IS COMES OVER THE
MOUNTAINS...AND IT SHOULD NOT BE MUCH OF A FACTOR. TOWARD
MORNING...WINDS WILL SHIFT TO THE NORTHEAST...AND AN IFR CEILING IS
POSSIBLE BUT CONFIDENCE IS FAIRLY LOW. LOOK FOR A COMBINATION OF
CEILING AND VISIBILITY PROBLEMS AROUND SUNRISE...BECOMING VFR AT ALL
TERMINALS BY 13-14Z. WINDS WILL CONTINUE TO VEER TO THE EAST
NORTHEAST...THEN SOUTHEAST ALONG THE COAST IN THE AFTERNOON WITH THE
RESULTANT.
EXTENDED OUTLOOK...LOW CONFIDENCE SHOWERS/ISOLATED THUNDERSTORM
MONDAY AND TUESDAY. SCATTERED CONVECTION POSSIBLE WEDNESDAY WITH A
BETTER CHANCE FOR PRECIP ON THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM SATURDAY...LATEST OBSERVATIONS OVER THE ILM NC WATERS
INDICATE SEAS STILL RUNNING WITHIN SCA THRESHOLDS ACROSS THE OUTER
WATERS OFF CAPE FEAR. THE SCA WILL REMAIN THRU MIDNIGHT WHICH IS
AMPLE TIME FOR THESE SEAS TO SUBSIDE BELOW SCA THRESHOLDS. GUIDANCE
CONTINUES TO FURTHER SUBSIDE SEAS DURING THE PRE-DAWN HRS OF SUNDAY
AS A COLD FRONT DROPS SOUTH ACROSS THE ILM WATERS BETWEEN 1 AM AND 7
AM SUNDAY. WINDS WILL VEER TO THE N-NE AFTER FROPA AND AID IN
KNOCKING DOWN THE BUILT UP SHORT PERIOD SW WIND DRIVEN SEAS FROM THE
PAST 1-2 DAYS. COULD SEE THE LAST ROUND OF CONVECTION MOVE OFF THE
MAINLAND THROUGH 2 AM SUNDAY. OTHERWISE...LOOK FOR A N-NE MINI SHORT
LIVED COLD SURGE BEHIND THE COLD FRONT...LASTING THROUGH MID TO LATE
SUNDAY MORNING.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 PM SATURDAY...COLD FRONT WILL BE POSITIONED OFFSHORE AT
THE START OF THE PERIOD WITH N/NE WINDS ONGOING ACROSS THE WATERS.
RIDGE OF HIGH PRESSURE BUILDS IN FROM THE SOUTH DURING THE AFTN AND
WINDS BECOME LIGHT...VEERING TO THE SW THROUGH THE EVE AS A
PRE FRONTAL AIRMASS MOVES OVER THE AREA AND INCREASING RAPIDLY TO
15-20 KTS SUN NIGHT AS A COLD FRONT APPROACHES FROM THE WEST. COLD
FRONT DROPS SOUTH DURING MONDAY...AND WINDS WILL GRADUALLY VEER FROM
SW TO N...THEN NE MONDAY NIGHT...ALL AT SPEEDS OF AROUND 10 KTS.
LACK OF ANY MEANINGFUL SWELL WITHIN THE WAVE SPECTRUM MEANS THAT
SEAS WILL BE PRIMARILY WIND DRIVEN...2-3 FT THROUGH THE
PERIOD...WITH A COMBINATION OF NE AND SW CHOP SUNDAY...BECOMING
DOMINATED BY NE WAVE ON MONDAY.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 300 PM SATURDAY...MAIN EVENT FOR THE MARINE
COMMUNITY WILL BE THE BACK DOOR FRONT MOVING ACROSS THURSDAY. THIS
FRONT WILL EVENTUALLY BRING ALL WINDS AROUND TO NORTHEAST BUT FOR
MOST OF THE DAY THURSDAY THE NORTH CAROLINA AND SOUTH CAROLINA
WATERS WILL BE DIVIDED BY THE FRONT. FOR EARLIER IN THE
PERIOD...EASTERLY WINDS INITIALLY WITH A SOUTH TO SOUTHWESTERLY FLOW
DEVELOPING LATER TUESDAY AND PREVAILING THROUGH WEDNESDAY. SEAS ARE
GENERALLY 2-4 FEET WITH WINDS WAVES DOMINATING THE SPECTRUM.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR
AMZ250-252.
&&
$$
NEAR TERM...DCH
SHORT TERM...JDW
LONG TERM...SHK
AVIATION...HDL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
745 PM EDT SAT MAR 31 2012
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL IMPACT THE AREA THROUGH TONIGHT AS
A COLD FRONT CROSSES THE AREA ...AND THEN MOVES OFF THE COAST.
DRY WEATHER IS EXPECTED SUNDAY AS HIGH PRESSURE PASSES ACROSS THE
REGION. A WEAK COLD FRONT WILL DROP SOUTH THROUGH THE AREA MONDAY.
UNSETTLED CONDITIONS WILL RETURN BY THE MIDDLE OF NEXT WEEK AS A
LOW PRESSURE SYSTEM APPROACHES THE EASTERN CAROLINAS.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 735 PM SATURDAY...LATEST SFC ANALYSIS PLACES THE COLD FRONT
GENERALLY FROM THE NC-VA BORDER AT THE COAST...WESTWARD TO ROUGHLY
ASHEVILLE. HRRR INDICATES 1 MORE MINI ROUND OF CONVECTION TO PUSH
THROUGH IMMEDIATELY AHEAD OF THE COLD FRONT BETWEEN 02Z-06Z. HAVE
INDICATED LOW CHANCE POPS THROUGH MIDNIGHT PRIOR TO THE CFP. LOOKING
AT NAM 1K-8H THICKNESS PACKING AND HRRR HRLY WINDS...THE COLD FRONT
WILL DROP NEARLY DUE SOUTH ACROSS THE FA BETWEEN 2AM AND 7AM SUNDAY.
LOOK FOR NW WINDS TO VEER TO THE N-NE ALONG WITH A MINI CAA SURGE
THAT WILL ONLY LAST THRU MIDDAY SUNDAY B4 SHUTTING OFF. WITH THREAT
OF PCPN INTO THE EARLY AM HRS OF SUNDAY AND CLOUDS STICKING AROUND
FOR MUCH OF THE NIGHT...HAVE KEPT FOG DEVELOPMENT AT A MINIMUM. IN
ADDITION...HAVE INCREASED OVERNIGHT LOWS A FEW DEGREES ESPECIALLY
THE SOUTHERNMOST LOCALES WHERE THE FROPA WILL COINCIDE WITH
DAYBREAK.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 300 PM SATURDAY...COLD FRONT POSITIONED JUST OFFSHORE AT THE
START OF THE PERIOD. NVA AND SOME DRY AIR ADVECTION THROUGH THE MID
LEVELS OF THE COLUMN KEEP SUNDAY SUNNY...BUT TEMPS WILL WARM WELL
INTO THE 70S WITH LACK OF ANY CAA AND ENHANCED RIDGING ALOFT. TEMPS
REMAIN WELL ABOVE CLIMO SUNDAY NIGHT AS GRADIENT TIGHTENS BETWEEN
RIDGE OF HIGH PRESSURE AND ADVANCING COLD FRONT FROM THE NORTH. THIS
COMBINED WITH SOME INCREASING MID-LEVEL CLOUDINESS WILL KEEPS MINS
IN THE MID/UPPER 50S.
SHORTWAVE TROUGH ROTATING DOWN FROM NEW ENGLAND SPAWNS A SURFACE LOW
IN THE MID ATLANTIC WHICH TRIES TO DRIVE A COLD FRONT THROUGH EARLY
MONDAY. WITH N/NW FLOW ALOFT...ANTICIPATE THIS FRONT TO WORK ALL THE
WAY SOUTH THROUGH THE CWA BY AFTN. DURING FROPA...MID LEVEL LAPSE
RATES STEEPEN AND FORECAST SOUNDINGS DEPICT INCREASING SATURATION IN
THE 800-500MB LAYER. FORCING IS NOT STRONG...BUT WILL ADD A SCHC POP
FOR TSTMS MONDAY...DECREASING FROM NORTH TO SOUTH THROUGH THE AFTN.
THIS FRONT WILL MAKE FOR A DIFFICULT TEMP FORECAST MONDAY AS
WELL...WITH 850MB TEMPS POSSIBLY FALLING THROUGH PEAK
HEATING...ESPECIALLY ACROSS NE ZONES. EXPECT TEMPS TO RANGE FROM THE
UPPER 80S IN THE TYPICAL WARM PEE DEE LOCATIONS...TO AROUND 80 IN
THE NORTHEAST ZONES...EVEN WITH FAVORED DOWNSLOPE COMPRESSIONAL
WARMING OCCURRING.
FRONT STALLS SOUTH OF THE AREA AND SOME ISENTROPIC LIFT BEGINS LATE
MONDAY NIGHT...ESPECIALLY ACROSS THE SOUTHERN PORTIONS OF THE CWA.
WILL RAMP POP BACK UP TO SCHC ACROSS THE SOUTH. MINS WILL FALL TO
AROUND 50 ACROSS THE NORTHEAST CWA...TO NEAR 60 IN THE SOUTH.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 300 PM SATURDAY...AMPLITUDE WILL ONCE AGAIN BE
THE NAME OF THE GAME FOR THE EXTENDED AS A LARGE MID LEVEL CYCLONE
WILL BE WOBBLING OVER THE FOUR CORNERS REGION INITIALLY WITH RIDGING
JUST WEST OF OUR REGION. AT THE SURFACE A FRONT WILL RESIDE JUST TO
THE SOUTHWEST BEFORE GETTING WASHED OUT WEDNESDAY. A BACKDOOR FRONT
WILL MOVE ACROSS THURSDAY INCREASING THE WEAK FORCING MECHANISMS IN
PLACE...THIS AS THE MID LEVEL PATTERN AMPLIFIES SLIGHTLY. FINALLY
LATE THURSDAY AND FRIDAY THE MAIN SYSTEM ASSOCIATED WITH THE
PREVIOUSLY MENTIONED MID LEVEL LOW MOVES ACROSS. BOTTOM LINE...I
HAVE INCREASED POPS FROM TUESDAY THROUGH THURSDAY INCREMENTALLY
BASED ON A DIURNAL SCENARIO. THE NEW DAY...SATURDAY LOOKS DRY AT
THIS POINT BUT THE INHERIT DIFFICULTIES OF FORECASTING A CLOSED
SYSTEM THIS FAR OUT IN TIME MAKE FOR A LOW CONFIDENCE DRY
FORECAST.
REGARDING TEMPERATURES...HAVE INCREASED TEMPERATURES A BIT ACROSS
THE BOARD TO MATCH GUIDANCE AND ADJACENT OFFICES BUT OVERALL TRENDS
OF SLIGHTLY ABOVE EARLY TREND TO NEAR NORMAL LATE REMAIN INTACT.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 00Z...LINGERING CONVECTION WILL AFFECT MYR FOR THE FIRST HOUR
OR SO...THEN MOVE OFFSHORE WITH THE PRE FRONTAL TROUGH. AFTER
03Z...A SECONDARY BATCH OF CONVECTION IS POSSIBLE WITH THE ACTUAL
FRONT. THIS PRECIP WILL BE WANING AS IS COMES OVER THE
MOUNTAINS...AND IT SHOULD NOT BE MUCH OF A FACTOR. TOWARD
MORNING...WINDS WILL SHIFT TO THE NORTHEAST...AND AN IFR CEILING IS
POSSIBLE BUT CONFIDENCE IS FAIRLY LOW. LOOK FOR A COMBINATION OF
CEILING AND VISIBILITY PROBLEMS AROUND SUNRISE...BECOMING VFR AT ALL
TERMINALS BY 13-14Z. WINDS WILL CONTINUE TO VEER TO THE EAST
NORTHEAST...THEN SOUTHEAST ALONG THE COAST IN THE AFTERNOON WITH THE
RESULTANT.
EXTENDED OUTLOOK...LOW CONFIDENCE SHOWERS/ISOLATED THUNDERSTORM
MONDAY AND TUESDAY. SCATTERED CONVECTION POSSIBLE WEDNESDAY WITH A
BETTER CHANCE FOR PRECIP ON THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 735 PM SATURDAY...LATEST OBSERVATIONS OVER THE ILM NC WATERS
INDICATE SEAS STILL RUNNING WITHIN SCA THRESHOLDS ACROSS THE OUTER
WATERS OFF CAPE FEAR. WILL EXTEND THE SCA THRU MIDNIGHT ALLOWING THE
SEAS TO SUBSIDE BELOW SCA THRESHOLDS. GUIDANCE CONTINUES TO FURTHER
SUBSIDE SEAS DURING THE PRE-DAWN HRS OF SUNDAY AS A COLD FRONT DROPS
SOUTH ACROSS THE ILM WATERS BETWEEN 1 AM AND 7 AM SUNDAY. WINDS WILL
VEER TO THE N-NE AFTER FROPA AND AID IN KNOCKING DOWN THE BUILT UP
SHORT PERIOD SW WIND DRIVEN SEAS FROM THE PAST 1-2 DAYS. COULD SEE A
ROUND OF CONVECTION MOVE OFF THE MAINLAND IMMEDIATELY PRIOR TO THE
CFP. OTHERWISE...LOOK FOR A N-NE MINI SHORT LIVED COLD SURGE BEHIND
THE FRONT THROUGH MID TO LATE SUNDAY MORNING.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 PM SATURDAY...COLD FRONT WILL BE POSITIONED OFFSHORE AT
THE START OF THE PERIOD WITH N/NE WINDS ONGOING ACROSS THE WATERS.
RIDGE OF HIGH PRESSURE BUILDS IN FROM THE SOUTH DURING THE AFTN AND
WINDS BECOME LIGHT...VEERING TO THE SW THROUGH THE EVE AS A
PRE FRONTAL AIRMASS MOVES OVER THE AREA AND INCREASING RAPIDLY TO
15-20 KTS SUN NIGHT AS A COLD FRONT APPROACHES FROM THE WEST. COLD
FRONT DROPS SOUTH DURING MONDAY...AND WINDS WILL GRADUALLY VEER FROM
SW TO N...THEN NE MONDAY NIGHT...ALL AT SPEEDS OF AROUND 10 KTS.
LACK OF ANY MEANINGFUL SWELL WITHIN THE WAVE SPECTRUM MEANS THAT
SEAS WILL BE PRIMARILY WIND DRIVEN...2-3 FT THROUGH THE
PERIOD...WITH A COMBINATION OF NE AND SW CHOP SUNDAY...BECOMING
DOMINATED BY NE WAVE ON MONDAY.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 300 PM SATURDAY...MAIN EVENT FOR THE MARINE
COMMUNITY WILL BE THE BACK DOOR FRONT MOVING ACROSS THURSDAY. THIS
FRONT WILL EVENTUALLY BRING ALL WINDS AROUND TO NORTHEAST BUT FOR
MOST OF THE DAY THURSDAY THE NORTH CAROLINA AND SOUTH CAROLINA
WATERS WILL BE DIVIDED BY THE FRONT. FOR EARLIER IN THE
PERIOD...EASTERLY WINDS INITIALLY WITH A SOUTH TO SOUTHWESTERLY FLOW
DEVELOPING LATER TUESDAY AND PREVAILING THROUGH WEDNESDAY. SEAS ARE
GENERALLY 2-4 FEET WITH WINDS WAVES DOMINATING THE SPECTRUM.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR
AMZ250-252.
&&
$$
NEAR TERM...DCH
SHORT TERM...JDW
LONG TERM...SHK
AVIATION...HDL
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
845 PM CDT SAT MAR 31 2012
.DISCUSSION...
CHALLENGES FOR TONIGHT INCLUDE TEMPERATURES AND FOG POTENTIAL.
WILL LEAN ON HIGH RESOLUTION RUC/HRRR GUIDANCE FOR EVENING UPDATE.
CLEAR SKIES WILL GIVE WAY TO INCREASING MID-HIGH LEVEL CLOUDS
ALONG STRENGTHENING MID-LEVEL BAROCLINIC ZONE. THERE ARE SOME
RADAR ECHOES ACROSS NORTHEAST MT AND NORTHWEST ND...BUT VERY
LITTLE LIQUID IS REACHING THE GROUND. WILL MAINTAIN SLIGHT CHANCE
POPS AFTER MIDNIGHT ACROSS PORTIONS OF THE DEVILS LAKE BASIN AND
NORTHERN VALLEY...BUT DO NOT ANTICIPATE MUCH ACCUMULATION IF ANY.
INCREASING WARM AIR ADVECTION FROM THE WEST WILL KEEP NIGHTTIME
LOWS ELEVATED INTO THE MID TO UPPER 40S ACROSS EASTERN ND WITH
SLIGHTLY COOLER CONDITIONS EAST OF THE RIVER GIVEN LOWER DAYTIME
HIGHS AND CLEAR SKIES EARLY THIS EVENING.
BIG QUESTION FOR TONIGHT IS FOG. LATEST HRRR SHOWS VISIBILITY
DROPPING TO LESS THAN ONE HALF MILE ACROSS A LARGE SWATH OF NORTH-
CENTRAL AND NORTHWEST MN AFTER 03 UTC. THIS MAKES SENSE GIVEN HIGH
SURFACE DEW POINTS...LIGHT WIND AND CLEAR SKIES THIS EVENING. DO
NOT THINK LOW STRATUS DECK ACROSS EASTERN MN WILL RETROGRADE TO
THE WEST TOO FAR GIVEN WEAK SURFACE FLOW...BUT AREAS OF FOG ARE
POSSIBLE. ADDED AREAS OF FOG EAST OF THE VALLEY FROM 06 TO 15 UTC
THIS MORNING. WILL MONITOR THE LATEST CONDITIONS AND UPDATE THE
FORECAST AS NEEDED.
&&
.AVIATION...
CLEAR SKIES WILL GIVE WAY TO SOME INCREASING MID-HIGH LEVEL
CLOUDS OVERNIGHT. BIGGER CONCERN IS FOG POTENTIAL ALONG AND EAST OF
THE VALLEY GIVEN HIGH LOW-LEVEL MOISTURE AND LIGHT WIND. COVERAGE
AND TIMING UNCERTAINTY EXISTS...SO WILL WAIT TO ADD MENTION AND
UPDATE AS NECESSARY.
&&
.PREV DISCUSSION... /ISSUED 230 PM CDT SAT MAR 31 2012/
DISCUSSION...FORECAST CHALLENGE CONCERNS SHORT TERM RAIN CHANCES
AND TEMPERATURES. MAIN MODEL DIFFERENCES ARE TIMING OF BOUNDARY
PASSAGE LATER SUNDAY. GFS/GEM A COMPROMISE BETWEEN QUICKER NAM AND
SLOWER ECMWF SO WILL USE GFS FOR TIMING PURPOSES.
WEAK SURFACE BOUNDARY SHOULD CONTINUE TO PUSH EAST REMAINDER OF
AFTERNOON FOLLOWED BY SURFACE HIGH PRESSURE. RIDGE AXIS SHIFTS OVER
EASTERN FA TOWARDS MORNING AND WITH EXPECTED SKC COULD SEE SOME
PATCHY FOG. ELSEWHERE EASTERLY FLOW AHEAD OF NEXT SYSTEM SHOULD
INCREASE ENOUGH TO LIMIT FOG ELSEWHERE. WILL SEE A N-S LOW LEVEL
MOISTURE GRADIENT SO WARMEST TEMPERATURES EXPECTED ACROSS THE SOUTH.
WILL MAINTAIN LOW POPS ACROSS FAR N-W AS DEEPER LAYERED RH INCREASES
SOME ALONG WITH SOME MID LEVEL FRONTOGENETIC FORCING.
MID LEVEL RIDGE SHIFTS ACROSS FA ON SUNDAY. SURFACE BOUNDARY WILL
SHIFT EAST BUT THINKING BOUNDARY WILL REMAIN WEST OF FA THROUGH THE
AFTERNOON. THIS WILL KEEP FA IN WARM SECTOR AND IF CLOUDS ARE
LIMITED COULD SEE SOME RECORD HIGHS FALL. WILL BE WINDY AND WILL
NEED TO BE MONITORED FOR POTENTIAL ADVISORY HEADLINES. NORTHERN MN
WILL HAVE SOME LOWER DEWPOINTS BUT TEMPERATURES WILL BE COOLER SO
FEEL CONDITIONS WILL BE BLO ANY FIRE WEATHER CONCERNS.
BOUNDARY CROSSES FA SUNDAY NIGHT. AIRMASS AHEAD OF THIS FEATURE
PRIMARILY ACROSS MN BECOMES MODESTLY UNSTABLE WITH SOME ELEVATED
CAPE SO WILL MAINTAIN LOW CHANCES FOR ELEVATED THUNDERSTORMS.
MID LEVEL FLOW BECOMES SPLIT WITH NORTHERN STREAM WAVE TO AFFECT FA
MONDAY. MODELS DIFFER ON TIMING OF BOUNDARY AND APPROACHING MID
LEVEL SUPPORT. ECMWF SLOWER WITH PASSAGE OF INVERTED TROUGH AND
SPREADING MORE PCPN ON COLD SIDE OF TROUGH SO WILL SPREAD POPS
FARTHER WEST A BIT.
HIGH PRESSURE TO BUILD IN FROM WEST TO EAST MONDAY NIGHT INTO
TUESDAY. TUESDAY LOOKS DRY WITH ABOVE AVERAGE TEMPERATURES.
LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
GFS/ECMWF/DGEX/GEM IN GOOD AGREEMENT THROUGH 00 UTC FRIDAY...
DIVERGING SOMEWHAT THEREAFTER WITH NEXT EASTERN PACIFIC TROUGH.
TUESDAY THROUGH MOST OF FRIDAY WILL BE QUITE PLEASANT AS AN UPPER
LEVEL RIDGE AND SURFACE HIGH MOVE SLOWLY ACROSS THE NATION/S
MIDSECTION. WITH THE EXCEPTION OF SOME LIGHT RAIN SHOWERS POSSIBLE
WEST OF THE VALLEY LATE FRIDAY...CONDITIONS WILL BE DRY WITH HIGHS
IN THE 60S AND LOWS IN THE 40S. THE SURFACE PRESSURE GRADIENT WILL
STRENGTHEN THURSDAY AND FRIDAY AS THE SURFACE HIGH MOVES INTO THE
GREAT LAKES...RESULTING IN BREEZY SOUTHERLY WIND EACH AFTERNOON.
GFS AND ECMWF SHOW A SHORT-WAVE EJECTING NORTHEASTWARD FROM WESTERN
CONUS TROUGH FRIDAY NIGHT ANS SATURDAY. PWATS AROUND AN INCH MAY
RESULT IN SOME DECENT RAIN...BUT WITH LITTLE INSTABILITY...ONLY
EXPECT SHOWERS AT THIS TIME. TEMPERATURES WILL COOL SATURDAY WITH
HIGHS DROPPING INTO THE 50S.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
ROGERS/VOELKER
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...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
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 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 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 SAN ANGELO TX
635 PM CDT SAT MAR 31 2012
.DISCUSSION...
EXPECT VFR CONDITIONS TO CONTINUE ACROSS WEST CENTRAL TEXAS FOR
THE NEXT 24 HOURS. AVIATION BELOW HAS ADDITIONAL INFORMATION.
&&
.AVIATION...
MODELS CONTINUE TO HOLD A SURFACE TROUGH OF LOW PRESSURE...AND AN
ASSOCIATED SURFACE DRYLINE...IN THE TEXAS AND NEW MEXICO AREA FOR
THE NEXT 24 HOURS. THE LATEST RUC INDICATES THE SURFACE PRESSURE
GRADIENT WILL INCREASE ACROSS WEST CENTRAL TEXAS OVERNIGHT
TONIGHT. THUS...LOOK FOR GUSTY SOUTHWEST SURFACE WINDS TO DOMINATE
WEST CENTRAL TEXAS BY 06Z TONIGHT. FOR TOMORROW AFTERNOON...WATCH
FOR STRONGER SOUTHWEST SURFACE WINDS AS THE SURFACE PRESSURE GRADIENT
STRENGTHENS ACROSS WEST CENTRAL TEXAS.
HUBER
&&
.PREV DISCUSSION... /ISSUED 334 PM CDT SAT MAR 31 2012/
SHORT TERM...
AN UPPER LEVEL RIDGE WILL AMPLIFY THROUGH TOMORROW AS IT BUILDS EAST
OF THE FORECAST AREA AHEAD OF AN APPROACHING UPPER LEVEL TROUGH...
WHICH WILL BE OVER THE SOUTHERN ROCKIES BY LATE TOMORROW. HOT AND
DRY WEATHER WILL CONTINUE ACROSS WEST CENTRAL TEXAS TOMORROW WITH
LOW TO UPPER 90S OVER THE CWA...THE WARMEST TEMPERATURES SHOULD BE
OVER THE NORTHERN HALF OF THE CWA AS THE 850MB THERMAL RIDGE LIFTS
FURTHER TO THE NORTH.
15
LONG TERM...
THE DEEP CLOSED LOW OFF THE PACNW COAST WILL BE A PLAYER IN OUR
WEATHER AS THE LONG TERM OPENS BUT THE MEDIUM RANGE MODELS
CONTINUE TO STRUGGLE WITH THE TIMING. THE LATEST RUNS SUGGEST THAT
THIS FEATURE WILL SLOW AS IT MOVES ACROSS THE SOUTHWEST
CONUS...LIFTING NORTHEAST ACROSS THE TX PANHANDLE AFTER 00Z
WEDNESDAY. THIS LATER ARRIVAL WILL LIKELY RESULT IN THE DRYLINE
SETTING UP FARTHER WEST THAN PREVIOUS ANTICIPATED GIVEN WEAKER
FORCING. STRONG SYNOPTIC LIFT /DEPICTED BY H5-H3 Q VECTOR
CONVERGENCE/ IS PROGGED TO REMAIN WEST OF THE CWA UNTIL MONDAY
NIGHT BY WHICH TIME THE DRYLINE WILL BE RETREATING. THUNDERSTORMS
WILL BE POSSIBLE ALONG AND EAST OF THE DRYLINE LATE MONDAY
AFTERNOON. SURFACE TEMPS IN THE MID/UPPER 80S AND DEWPOINTS WILL
RESULT IN SIGNIFICANT INSTABILITY /SBCAPES OF 1500-3000/ BUT A
SLOWER ARRIVAL OF SYNOPTIC ASCENT MAY RESULT IN THE CAP HOLDING
STRONG AND LIMITING THE CONVECTIVE POTENTIAL /ESPECIALLY IN THE
EAST IN THE AREA OF STRONGEST INSTABILITY/...MUCH OF THE CHAGRIN
OF THE SOUTHERN PLAINS CHASE COMMUNITY. I OPTED TO MAINTAIN THE
INHERITED POPS ON THE CENTRAL AND EAST ON MONDAY AFTERNOON BUT
EXPANDED THEM WEST MONDAY NIGHT AND TUESDAY TO ACCOUNT FOR THE
SLOWER TIMING.
COOLER TEMPS ARE EXPECTED ON TUESDAY AS A PACIFIC COLD FRONT MOVES
THROUGH THE AREA. I LOWERED MAX TEMPS INTO THE MID/UPPER 70S BUT
FEEL I MAY STILL BE A FEW DEGREES ON THE WARM SIDE BASED ON H85
TEMPS. I AM NOT SOLD ON THE AGGRESSIVE RETURN OF SOUTHERLY FLOW
SHOWN BY THE GFS AND LEANED MORE HEAVILY ON THE ECMWF SOLUTION IN
THE POST FRONTAL ENVIRONMENT. WITH THAT SAID...I KEPT MAX TEMPS
GENERALLY AT OR JUST BELOW 80 DEGREES ON WEDNESDAY BUT DRY
CONDITIONS WILL RESULT IN A VERY PLEASANT DAY. MIN TEMPS TUESDAY
NIGHT ARE EXPECTED TO BE IN THE MID/UPPER 50S...WARMING SLIGHTLY
/LOWER 50S/ BY WEDNESDAY NIGHT. BY THURSDAY...THE H85 THERMAL RIDGE
WILL BUILD BACK OVER THE AREA WITH INCREASING SOUTHERLY WINDS. TEMPS
ARE EXPECTED TO WARM BACK INTO THE MID 80S. THESE SOUTHERLY WINDS
WILL BRING THE LOW LEVEL MOISTURE BACK THURSDAY NIGHT AND FRIDAY.
THE MODELS ARE HINTING AT SOME CONVECTION DEVELOPING OVER WEST TX
FRIDAY EVENING ALONG THE DRYLINE BUT MY GUT SAYS THAT MOISTURE
RETURN WILL NOT BE ADEQUATE TO SUPPORT MORE THAN FEW HIGH BASED
STORMS. THUS...NO POPS WERE INCLUDED AT THIS TIME.
HOWEVER...CONSIDERABLE UNCERTAINTY EXISTS AT THIS TIME. TEMPS WILL
AGAIN BE WARM ON FRIDAY WITH HIGHS IN THE MID/UPPER 80S.
THE GFS/DGEX DEPICT A WEAK COLD FRONT STALLING OVER THE AREA BY NEXT
WEEKEND...ENHANCING RAIN CHANCES. HOWEVER...THE ECMWF KEEPS THIS
BOUNDARY NORTH OF THE CWA IN CONJUNCTION WITH THE UPPER LEVEL
SYSTEM. THE ECMWF ALSO PUSHES H5 HEIGHTS UP NEAR 585DM WITH THE MID
LEVEL ANTICYCLONE CENTERED OVER DEEP SOUTH TX WHEREAS THE GFS KEEPS
HEIGHTS AROUND 580DM WITH THE RIDGE CENTERED OVER THE GULF OF
MEXICO. I WILL LET THE MODELS CONTINUE TO TEASE US OVER THE NEXT FEW
DAYS BEFORE JUMPING ON ANY PARTICULAR SOLUTION.
JOHNSON
FIRE WEATHER...
ELEVATED FIRE WEATHER CONDITIONS CAN BE EXPECTED SUNDAY OVER THE BIG
COUNTRY...CONCHO VALLEY AND THE NORTHERN EDWARDS PLATEAU WITH
UNSEASONABLY HOT TEMPERATURES IN THE 90S CONTINUING...ACCOMPANIED BY
LOW RELATIVE HUMIDITY VALUES...AND SOUTHWEST WINDS BETWEEN 15 AND 20
MPH. CRITICAL FIRE WEATHER CONDITIONS ARE POSSIBLE MAINLY WEST OF A
LINE FROM HASKELL TO STERLING CITY SUNDAY AFTERNOON WITH 20 FOOT
SOUTHWEST WINDS APPROACHING 20 MPH AND RELATIVE HUMIDITY VALUES
DROPPING TO LESS THAN 10 PERCENT.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 65 96 65 85 52 / 0 0 0 20 30
SAN ANGELO 60 96 62 86 51 / 0 0 0 20 20
JUNCTION 62 93 64 87 51 / 10 10 10 20 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
HUBER
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...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 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 BLACKSBURG VA
949 PM EDT SAT MAR 31 2012
.SYNOPSIS...
WEAK HIGH PRESSURE WILL CONTINUE TO BUILD INTO OUR AREA TONIGHT.
THIS HIGH WILL MOVE SOUTHEAST OF OUR AREA ON SUNDAY. ANOTHER
APPROACHING COLD FRONT WILL ENTER OUR AREA BY MONDAY MORNING.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 945 PM EDT SATURDAY...
PERSISTENT CLUSTER OF SCATTERED THUNDERSTORMS FROM GRAYSON COUNTY
INTO WILKES COUNTY WAS GRADUALLY DRIFTING EAST. AREAS RADAR
CONTINUES TO SHOW ISOLATED SHOWERS AND THUNDERSTORMS ON THE
EASTERN AND SOUTHEAST FRINGE OF THE COUNTY WARNING AREA. LOCAL WRF
AND HRRR GUIDANCE HAD PRECIPITATION ENDING ACROSS THE FORECAST
AREA BY MIDNIGHT. ADJUSTED PROBABILITY OF PRECIPITATION IN THE
FORECAST FOR THIS TIMING. ALSO ADDED PATCHY FOG IN FOG THE
GREENBRIER RIVER VALLEY AND IN THE AREAS ACROSS THE SOUTHWEST
COUNTY WARNING AREA THAT HAD RAIN SATURDAY AFTERNOON AND EVENING.
DEW POINTS HAVE ALREADY DROPPED INTO THE UPPER 30S TO LOWER 40S
IN THE FAR NORTHERN COUNTY WARNING AREA. SURFACE DEW POINTS WILL
CONTINUE TO LOWER BEHIND THE FRONT ACROSS THE SOUTHERN COUNTIES OF
THE FORECAST AREA. HAD MADE SLIGHT ADJUSTMENTS TO OVERNIGHT LOWS
BASED ON 9PM OBS...CLOUD COVER AND THE LATEST LAMP GUIDANCE.
NAM AND LOCAL WRF HAD LAYER OF LOW CLOUDS SPREADING ACROSS CENTRAL
AND EASTERN VIRGINIA OVERNIGHT...AND REACHING AS FAR WEST AS
LYNCHBURG AND DANVILLE. HAVE ADDED MORE CLOUD COVER IN THE EAST
SINCE CEILINGS ARE ALREADY LOWERING JUST NORTH AND EAST OF THE
FORECAST AREA. THE CLOUDS IN THE EAST MAY TAKE MOST OF THE MORNING
TO MIX OUT. BUFKIT SOUNDINGS WERE SUGGESTING THAT CLOUDS MAY NOT
BECOME SCATTERED UNTIL AFTER 11AM.
AS OF 330 PM EDT SATURDAY...
SURFACE ANALYSIS INDICATES THAT THE COLD FRONT IS LOCATED ACROSS
OUR SOUTHERNMOST TIER OF COUNTIES THIS AFTERNOON...AND IS
CONTINUING TO MOVE SOUTHEAST. RADAR HAS INDICATED THAT SPOTTY
SHOWER ACTIVITY...AND A FEW THUNDERSTORMS...HAS DEVELOPED ACROSS
OUR AREA WITH AFTERNOON HEATING...BUT NONE OF THIS ACTIVITY IS
VERY STRONG. THAT STATED...CANNOT RULE OUT ONE OR TWO STRONG BUT
SHORT LIVED THUNDERSTORMS DEVELOPING DURING EARLY EVENING.
WEAK HIGH PRESSURE WILL CONTINUE TO BUILD INTO OUR AREA THIS
EVENING...WHICH WILL RESULT IN NORTHWESTERLY FLOW THROUGH THE
FIRST FEW HOURS OF SUNDAY MORNING. THIS DOWNSLOPE FLOW WILL ALLOW
CLOUD COVER TO DIMINISH ACROSS MUCH OF OUR AREA...ESPECIALLY AFTER
SUNSET WITH THE LOSS OF DAYTIME HEATING. HOWEVER...WEATHER FORECAST
MODELS HAVE INDICATED THE POSSIBILITY OF LOW CLOUDS REDEVELOPING
TONIGHT ALONG THE EAST FACING SLOPES IN SOUTHEAST WEST VIRGINIA
AND THE MOUNTAIN EMPIRE...AS RESIDUAL LOW LEVEL MOISTURE BECOMES
WEDGED ALONG THE RIDGELINES. WITH LIGHT WINDS ACROSS THE
AREA...WILL ALSO BE LOOKING AT THE POSSIBILITY OF PATCHY FOG
DEVELOPING ACROSS PORTIONS OF THE MOUNTAINS...ESPECIALLY IN THE
RIVER VALLEYS.
THE HIGH WILL SLIDE SOUTHEAST BY SUNRISE SUNDAY MORNING...AND WE
WILL BEGIN TO SEE SOUTHERLY WINDS TAKE OVER. WITH PLENTY OF DRY
AIR ALOFT...EXPECT THAT ANY FOG AND LOW CEILINGS WILL BURN OFF BY
10 AM...AND EXPECT MOSTLY CLEAR SKIES THROUGH EARLY AFTERNOON
AREAWIDE.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 330 PM EDT SATURDAY...
ON SUNDAY NIGHT...THE NORTHEAST U.S. UPPER TROF DEEPENS IN RESPONSE
TO A SHORTWAVE MOVING SOUTHEAST. THIS WILL DRIVE A COLD FRONT
THROUGH THE FORECAST AREA AND SPARK A COMPLEX OF STORMS AS LOW LEVEL
THETA-E RIDGE INCREASES IN ADVANCE OF THE FRONT. BEST LOW LEVEL
CONVERGENCE WILL BE FOUND SE WV AND WEST OF I-77 WHERE HIGHEST POPS
WERE PLACED. INCREASED LOW TEMPERATURES A COUPLE OF DEGREES WITH A
FAIR AMOUNT OF CLOUDS AND MIXING.
AS WEAK HIGH PRESSURE TRIES TO WEDGE DOWN THE EASTERN U.S. A WEAK
LOW LEVEL CONVERGENCE ZONE IS ESTABLISHED IN THE FAR SOUTHWEST
PORTION OF THE FORECAST AREA. WITH THE GREATEST INSTABILITY EXPECTED
TO BE LOCATED HERE...WIDELY SCATTERED THUNDERSTORMS WILL BE
POSSIBLE. LEANED TOWARD THE COOLER NAM MOS GUIDANCE FOR HIGHS IN THE
EAST WITH A LOW LEVEL NORTHEAST FLOW IN PLACE.
FOR MONDAY NIGHT AND TUESDAY...AN UPPER LEVEL RIDGE TRIES TO BUILD
OVER THE REGION...BUT IS QUICKLY FLATTENED BY A NORTHERN STREAM
SYSTEM MOVES ACROSS SOUTHERN CANADA AND THE NORTHERN GREAT LAKES.
THE LOW LEVEL FLOW IN ADVANCE OF THIS SYSTEM COMES AROUND TO THE
SOUTH/SOUTHWEST USHERING IN HIGHER DEWPOINTS AND POTENTIALLY A DECK
OF LOW LEVEL STRATUS CLOUDS WITH GOOD MOISTURE ADVECTION. ISENTROPIC
LIFT ON THE LEADING EDGE OF THIS MAY BRING ANOTHER ROUND OF RAIN
THE FAR SOUTHWEST MONDAY NIGHT...WITH SHOWERS AND THUNDERSTORMS
DEVELOPING IN ADVANCE OF THE FRONT IN THE NORTHERN AND WESTERN
PORTION OF THE FORECAST AREA ON TUESDAY UNDER THE INSTABILITY AXIS.
TEMPERATURE FORECAST TUESDAY IS A TRICKY ONE AND HIGHS WILL DEPEND
ON THE AMOUNT OF CLOUD COVER SEEN. WITH THE POTENTIAL FOR LOW
CLOUDS TO ADVANCE INTO OUR AREA...DROPPED HIGHS A FEW DEGREES TOWARD
THE COOLER LOCALLY DERIVED MOS FORECAST HIGHS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 330 PM EDT SATURDAY...
FOR THE LONG TERM PORTION OF THE FORECAST...WE LEANED HEAVILY ON THE
00Z ECMWF SOLUTION WHICH SHOWS BETTER RUN TO RUN CONSISTENCY
COMPARED TO THE GFS WITH ITS HANDLING OF THE TIMING AND EVOLUTION OF
A CUT OFF LOW DRIFTING ACROSS THE SOUTHERN PLAINS...THEN THE
SOUTHEAST U.S. LATE IN THE PERIOD. THE ECMWF IS ALSO IN BETTER
AGREEMENT WITH THE CANADIAN AND UKMET SOLUTIONS. THE GFS ENSEMBLE
MEMBERS SHOW A WIDE RANGE OF POTENTIAL SOLUTIONS TO THE STRENGTH AND
LOCATION OF THIS UPPER LEVEL LOW WHICH GIVES US LOW CONFIDENCE IN
THE OPERATIONAL GFS SOLUTION.
SOME SIGNIFICANT MODIFICATIONS WERE MADE TO THE FORECAST BASED ON
THE ECMWF FORECAST. FIRST...WITH THE SLOWER TIMING...NOW EXPECT THE
COLD FRONT TO MOVE THROUGH LATE WEDNESDAY...ALLOWING TEMPERATURES TO
BE WELL ABOVE NORMAL WITH A DEEP WEST...DOWNSLOPING FLOW...WITH
THUNDERSTORMS POSSIBLE ALONG THE FRONT.
BEHIND THIS FRONT...TRENDED TEMPERATURES DOWN BY SEVERAL DEGREES
THUR-SATURDAY AS A LOW LEVEL NORTHEAST...THEN EAST...FLOW DEVELOPS
WITH THE UPPER LOW TO OUR SOUTH AND CANADIAN HIGH PRESSURE BUILDING
IN THE NE U.S.
WITH THE NAO FORECAST TO BECOME NEGATIVE AND THE GLOBAL WIND
OSCILLATION (GWO) IN A FAVORABLE PHASE FOR COOLER THAN NORMAL
CONDITIONS IN THE EASTERN U.S...THE COOLER ECMWF TEMPERATURES APPEAR
REASONABLE.
DEPENDING ON THE LOCATION OF THE UPPER LOW...SHOWERS/RAIN WILL BE
POSSIBLE EACH DAY...ESPECIALLY FOR THOSE FAVORED EASTERN UPSLOPE
AREAS AND TO THE SOUTH...CLOSER TO THE LOCATION OF THE UPPER LOW.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
AS OF 130 PM EDT SATURDAY...
ISOLATED THUNDERSTORMS WILL CONTINUE IN FAR SOUTHWEST VIRGINIA AND
EXTREME NORTHWEST NORTH CAROLINA AND IN SOUTH CENTRAL VIRGINIA
THROUGH MIDNIGHT. THESE STORMS ARE NOT EXPECTED TO IMPACT
BCB/LWB/BLF/LYH/ROA OR DAN.
MODELS WERE SHOWING LOW LEVEL MOISTURE BANKING UP AGAINST THE
WESTERN SLOPES OF THE APPALACHIANS TONIGHT. HAVE KEPT MVFR
CEILINGS IN THE TAF AT BLF FOR LATE TONIGHT THROUGH SUNRISE.
EXPECT A SMALL ENOUGH TEMPERATURE/DEW POINT SPREAD AT LWB FOR FOG
TO FORM OVERNIGHT. HAVE TYPICAL LIFR CONDITIONS AT LWB THROUGH
SUNRISE. MOISTURE IN THE WEST IS SHALLOW. FOG AND CLOUDS WILL DISSIPATE
QUICKLY IN THE MORNING.
NAM AND LOCAL WRF WERE SHOWING STRONGER NORTHEAST SURFACE AND LOW
LEVEL WINDS TONIGHT THAN THE OTHER GUIDANCE AND BRINGING MVFR
CLOUDS INTO LYH AND DAN AFTER 06Z. ALREADY SEEING THE LOW CLOUDS
ADVANCING WEST ON SATELLITE LOOPS. MEDIUM CONFIDENCE THAT THIS
CLOUD LAYER WILL REACH LYH/DAN AND HIGHER CONFIDENCE THAT THE
CLOUDS WILL STAY EAST OF ROA. MAKE TAKE MOST OF THE MORNING TO MIX
OUT TO VFR. BUFKIT WAS NOT SHOWING IMPROVEMENT UNTIL AFTER
15Z/11AM.
THE NEXT THREAT FOR WIDESPREAD FLIGHT RESTRICTIONS WILL OCCUR
LATE SUNDAY NIGHT OR ON MONDAY...POSSIBLY CONTINUING INTO THE MID
WEEK. WEAK SHORT WAVES AND MOISTURE STREAMING NORTHEAST OVER A
STALLED FRONT OVER/NEAR THE AREA...MAY SET THE STAGE FOR MVFR...AND
POTENTIALLY LOWER...FLIGHT RESTRICTIONS...ESPECIALLY OVER/IN THE
MOUNTAINS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/NF
NEAR TERM...AMS/NF
SHORT TERM...PH
LONG TERM...PH
AVIATION...AMS/NF
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
854 PM CDT SAT MAR 31 2012
.UPDATE...
SPC ADDED A SLGT RISK ON DAY 1 UPDATE THAT EXTENDS FROM EAST
CENTRAL IOWA INTO EAST CENTRAL ILLINOIS NORTH OF A DECENT LOW
LEVEL BAROCLINIC ZONE. THIS RISK AREA BARELY CLIPS SOUTHERN
LAFAYETTE COUNTY. LATEST RUC GUIDANCE IN GOOD AGREEMENT WITH 18Z
NAM/GFS IN TAKING STRONGEST 700 MB WARM ADVECTION SOUTH OF
WISCONSIN. INITIAL THUNDERSTORMS EAST OF DSM HAVE DEVELOPED RIGHT
IN THE MIDDLE OF THIS 700 MB ADVECTION ZONE...AND SHOULD RIDE DOWN
THE BAROCLINIC ZONE THROUGH THE HEART OF SLIGT RISK. DECENT 850
MB POSITIVE THETA-E ADVECTION IS SHOWN ON THE MODELS BRUSHING
SOUTHERN WISCONSIN...ALONG WITH LIGHT QPF. SO THIS CONTINUES TO
JUSTIFY LOW POPS ACROSS THE SOUTH.
PERSISTENT AND PESKY LOW CLOUD DECK AS FINALLY LIFTED ACROSS
SOUTHERN HALF...BUT IS TOPPED BY MID/HIGH CLOUDS. THESE SHOULD
CLEAR LATE TONIGHT AS WEAK DISTURBANCE SLIDES BY WHICH OPENS THE
DOOR FOR FOG/STRATUS TO REDEVELOP TOWARD MORNING. 18Z NAM KEPT
HIGH 925 MB RH THROUGH 21Z FOR SOUTHERN WISCONSIN...WHICH IS CAUSE
FOR CONCERN ON HIGH TEMPERATURE FORECAST AND SKY COVER ONCE AGAIN.
DID NOT ADJUST THESE YET BUT CAUTION IS ADVISED.
&&
.AVIATION/06Z TAFS/...
STRATUS LIFTING NORTH OF THE TAF SITES FOR THE TIME BEING.
THUNDERSTORMS SHOULD STAY SOUTH OF THE TAF SITES SO DID NOT
INCLUDE THEM AS PROBABLY A BIT TOO LOW.
CLEARING OF MIDDLE/HIGH CLOUDS LATER TONIGHT OPENS THE DOOR FOR
FOG AND STRATUS FORMATION BETWEEN 09Z AND 14Z. WENT WITH LIFR
VISIBILITY AND IFR CEILINGS BUT DID NOT GO 1/4SM PER BOTH GFS AND
NAM MOS OUTPUT. THIS IS CERTAINLY POSSIBLE AND WILL TAKE A CLOSE
LOOK PRIOR TO NEXT PRIMARY TAF ISSUANCE AT 00Z GUIDANCE TO SEE IF
WE NEED TO GO VLIFR. THIS STRATUS DECK COULD LINGER WELL INTO THE
DAY BUT LIKELY AS MVFR BUT CURRENTLY CLEAR THINGS OUT BY 18Z. THIS
TOO WILL BE PROBLEMATIC AND MAY NEED REVISION.
&&
.PREV DISCUSSION... /ISSUED 310 PM CDT SAT MAR 31 2012/
VERY SHORT TERM...TONIGHT AND SUNDAY.
LOW CLOUD DECK CONTINUES TO HOLD STRONG ACROSS THE REGION EARLY THIS
AFTERNOON...THOUGH STARTING TO SEE SOME OF THIS DECK MIX OUT IN
NORTHEAST ILLINOIS. ALSO SEEING CEILING HEIGHTS RISE AS WELL. AREA
RUC FORECAST SOUNDINGS AND TAMDAR SOUNDINGS SHOWING THIS DECK TO BE
ABOUT 1000 TO 2000 FEET THICK. RUC/NAM SOUNDINGS AND HIGH RESOLUTION
RAPID REFRESH MODEL SHOW THIS LOW DECK SLOWLY MIXING OUT THROUGH
LATE THIS AFTERNOON/EARLY EVENING. HOWEVER...MID TO HIGH CLOUDS
ASSOCIATED WITH WARM AIR ADVECTION WILL CONTINUE TO STREAM SOUTHEAST
THROUGH THE REGION DURING THIS TIME.
THUS...HAVE GONE WITH MOSTLY CLOUDY WORDING IN MOST AREAS INTO THE
EARLY EVENING. DID MIX OUT LOW CLOUDS IN THE FAR SOUTHEAST COUNTIES
BY 00Z SUNDAY...ASSUMING CURRENT TREND CONTINUES. THIS MAY HAVE TO
BE ADJUSTED RIGHT BEFORE FORECAST ISSUANCE. ONCE LOW CLOUDS MIX
OUT...MIDDLE TO HIGH CLOUDS SHOULD DEVELOP SOME BREAKS LATER THIS
EVENING AND OVERNIGHT. WARM AIR ADVECTION CONTINUES TONIGHT...AND
EXPECT A NON DIURNAL TREND WITH SLOWLY RISING TEMPERATURES...GIVEN
THE COOL TEMPERATURES TODAY. RISING DEW POINTS AND LIGHT AND
VARIABLE WINDS BY LATE TONIGHT/EARLY SUNDAY SHOULD ALLOW FOR FOG
FORMATION ACROSS THE AREA. PATCHY DENSE FOG IS POSSIBLE IN LOW LYING
AREAS...AND WILL HAVE TO BE WATCHED FOR MORE WIDESPREAD DEVELOPMENT
IF MIDDLE TO HIGH CLOUDS MOVE OUT QUICKER THAN EXPECTED.
12Z NAM/GFS/CANADIAN/ECMWF MODELS SHOWING WARM FRONT AND BULK OF
POSSIBLE ELEVATED CONVECTION LATER TONIGHT INTO SUNDAY MORNING
STAYING JUST SOUTH OF THE AREA. STILL HAVE 25 TO 30 KNOT WEST
SOUTHWESTERLY LOW LEVEL JET POINTING TOWARD THE AREA BY 06Z
SUNDAY...THEN VEERS DUE WEST LATER TONIGHT. NOT A LOT OF MOISTURE
ADVECTION AT 850MB INTO THE REGION WITH THIS FEATURE...BUT AREA
FORECAST SOUNDINGS DO SHOW 500 TO 1000 J/KG ELEVATED CAPE WITH
DECENT EFFECTIVE LAYER SHEAR. LOW WET BULB ZERO HEIGHTS SUGGEST
SMALL HAIL IS POSSIBLE WITH ANY STORMS THAT DO FORM AND MAKE IT INTO
THE AREA.
WENT WITH CHANCE POPS IN THE FAR SOUTHERN COUNTIES BETWEEN 06Z AND
12Z SUNDAY...WITH SLIGHT CHANCE POPS TO THE NORTH. KEPT SLIGHT
CHANCE WORDING SOUTHWEST OF MADISON MID TO LATE EVENING...AND IN THE
FAR SOUTHEAST SUNDAY MORNING. DRY AND PARTLY SUNNY SUNDAY AFTERNOON
WITH LACK OF UPWARD VERTICAL MOTION AND MOISTURE IN THE AREA.
ONSHORE WINDS WILL KEEP LAKESHORE AREAS MUCH COOLER...IN THE
50S...THAN WELL INLAND...IN THE 70S.
SHORT TERM...SUNDAY NIGHT THROUGH TUESDAY.
SHORT TERM GUIDANCE COMING INTO REASONABLE AGREEMENT CONCERNING
SURFACE FEATURES SUNDAY NIGHT AND MONDAY. INCREASED SUBSIDENCE
ASSOCIATED WITH EXPANDING MID-LEVEL RIDGING OCCURRING ON
SUNDAY...PERSISTS INTO MONDAY. SHARP RIDGE DIVERTS STRONGER SHORT
WAVES CAUGHT IN SOUTHWESTERLY FLOW TO THE NORTH AND WEST OF CWA. IN
ADDITION...850H LOW LEVEL JET REMAINS WEST AND WELL SOUTH OF
AREA...AT LEAST INITIALLY. WEAKER LLJ DEVELOPS OVER WI ON MONDAY
WHICH USHERS IN HIGHER LOW LEVEL RH. WARM MID-LEVELS RESULT IN
CAPPING FOR MOST OF MONDAY...BUT PASSING WEAK WAVE ACROSS CENTRAL WI
MAY HAVE JUST ENOUGH FORCING TO BREAK THROUGH CAP. HENCE WL CONTINUE
SCHC POPS FOR MON OVER MOST OF CWA...EXCEPT FAR SOUTH. EXPCD
BKN-OVC CLOUD COVER ACCOMPANYING SURGE OF HIGHER RH WL ALSO PREVENT
STRONGLY UNSTABLE AIRMASS. BETTER CHANCE FOR PRECIP AND T MONDAY
NIGHT AS MAIN SHORT WAVE TROUGH MOVES SOUTHEAST ACROSS WI. AT THIS
TIME...RIGHT EXIT OF 300H JET AND LAYER FN VECTOR RESPONSE TO
FRONTOGENESIS PASS THROUGH SRN WI...SO WL CONTINUE HIGH CHANCE POPS
FOR NOW. LACK OF MID LEVEL WAVE AND INDICATIONS OF POSSIBLE SPLIT
FORCING PREVENT ME FROM GOING WITH LIKELY WORDING FOR NOW.
MID-LEVEL TROUGH EXITS SRN WI TUE MRNG WITH DRIER...NLY FLOW
SETTLING INTO THE REGION. WITH WARM FRONT REMAINING TO THE SOUTH OF
WI FOR MONDAY...NEEDED TO LWR MAX TEMPS SLIGHTLY...ESPECIALLY IN THE
EAST DUE TO SELY WINDS AND EXPCD CLOUDS.
LONG TERM...TUESDAY NIGHT THROUGH SATURDAY.
THIS PERIOD STILL LOOKING GENERALLY DRY AND QUIET WITH TEMPERATURES
AVERAGING ABOVE THE SEASONAL NORMAL FOR EARLY APRIL. THERE MAY BE A
NIGHT OR TWO WHEN FROST WILL BE A POSSIBILITY WITH TEMPERATURES
FALLING INTO THE MID TO UPPER 30S LATE AT NIGHT...ESPECIALLY
THURSDAY NIGHT.
LINGERING WEAK MID-LEVEL TROUGH OVER SRN WI ON TUESDAY WILL SUCCUMB
TO INFLUENCE OF INCREASING LARGE SCALE RIDGING BUILDING INTO THE WRN
GTLAKES AND FURTHER WEAKEN AND MOVE EAST OF AREA BY TUESDAY NIGHT.
HENCE DRY CONDITIONS STILL ANTICIPATED FOR THE PERIOD FROM TUESDAY
NIGHT THROUGH FRIDAY.
HOWEVER ONE FLY POSSIBLY LANDING IN OUR SOUP IS THE TREND BY LAST
SEVERAL DETERMINISTIC RUNS OF BOTH THE GFS AND ECWMF PUSHING CUTOFF
LOW OVER SRN PLAINS FARTHER NORTH INTO THE CENTRAL PLAINS BY
MID-WEEK. ACTUALLY WITH LONG WAVE TROF SPREADING FROM THE NORTHERN
PACIFIC INTO THE NW CONUS...SEEMS REASONABLE THAT CUTOFF LOW WOULD
TRACK FARTHER NWD. OTHER LONG RANGE GUIDANCE INCLUDING GEM-NHEM AND
UKMO TRACK CUTOFF LOW EAST ACROSS CENTRAL MS VALLEY REGION WED NGT
AND THU WHILE LINGERING HIGH PRESSURE OVER THE WRN GTLAKES
SUPPRESSES LOW TO THE SOUTH. 12Z ECMWF DETERMINISTIC RUN...ECMWF
ENSEMBLE MEAN AND HPC ALSO LEANING TWD THIS CONTINUED DRY SOLUTION.
LONG WAVE TROUGH OVER WRN CONUS BY THE END OF THE WEEK WILL
EVENTUALLY RESULT IN INCREASING WARM AIR ADVECTION AND MOISTURE
RETURNING TO WISCONSIN LATER IN THE WEEKEND. HENCE THREAT FOR
PRECIP MAY INCREASE SAT NGT INTO SUN.
AVIATION /00Z TAFS/...MAINLY MVFR CEILINGS ARE EXPECTED TO LINGER
THROUGH LATE THIS AFTERNOON ACROSS TAF SITES...BEFORE MIXING OUT BY
EARLY EVENING. VFR CEILINGS WITH MID TO HIGH CLOUDS THEN EXPECTED
FROM MID TO LATE EVENING...BEFORE SOME BREAKS OCCUR LATER TONIGHT
AND INTO SUNDAY.
BEST CHANCES FOR ANY SHOWERS OR STORMS WOULD BE BETWEEN 06Z AND 12Z
SUNDAY...BUT BEST CHANCES REMAIN JUST SOUTH OF THE FORECAST
AREA...SO WILL NOT MENTION IN TAFS AT THIS TIME.
LIGHT WINDS BETWEEN 06Z AND 15Z SUNDAY...WITH LINGERING LOW LEVEL
MOISTURE...SHOULD ALLOW FOR IFR/LIFR FOG FORMATION. SOME HIGH CLOUDS
LINGERING SHOULD PREVENT WIDESPREAD DENSE FOG...BUT WILL HAVE TO BE
WATCHED CLOSELY IN CASE THEY CLEAR OUT QUICKER THAN EXPECTED. VFR
CONDITIONS THEN EXPECTED THROUGH THE REST OF SUNDAY. WINDS SHOULD
BECOME EAST NORTHEAST ON SUNDAY...AS WARM FRONT STAYS SOUTH OF THE
AREA.
MARINE...
WINDS AND WAVES WILL APPROACH SMALL CRAFT ADVISORY LEVELS MONDAY
THROUGH TUESDAY ACROSS THE NEARSHORE WATERS...AS LOW PRESSURE MOVES
SOUTH OF THE AREA. ONSHORE WINDS MONDAY SHOULD BUILD HIGH
WAVES...WITH TIGHT PRESSURE GRADIENT BRINGING BRISK ONSHORE WINDS
AND HIGH WAVES MONDAY NIGHT AND TUESDAY. HIGH WAVES MAY LINGER INTO
TUESDAY NIGHT BEFORE DIMINISHING.
CONFIDENCE...
TONIGHT AND SUNDAY...MEDIUM.
SUNDAY NIGHT THROUGH TUESDAY...MEDIUM.
TUESDAY NIGHT THROUGH SATURDAY...MEDIUM TO HIGH.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...CRAVEN
TONIGHT/SUNDAY AND AVIATION/MARINE...WOOD
SUNDAY NIGHT THROUGH SATURDAY...MBK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
659 PM CDT SAT MAR 31 2012
.SHORT TERM...THROUGH MONDAY NIGHT
301 PM CDT SAT MAR 31 2012
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TONIGHT AND THEN
SUNDAY NIGHT THROUGH MONDAY NIGHT.
SURFACE ANALYSIS THIS AFTERNOON SHOWS HIGH PRESSURE CENTERED OVER
LOWER MICHIGAN. A WEAK AREA OF LOW PRESSURE WAS OVER SOUTHEAST
SOUTH DAKOTA WITH A WARM FRONT ALONG THE MISSOURI RIVER INTO
NORTHERN MISSOURI.
VISIBLE SATELLITE SHOWS THE CLOUDS HAVE HUNG ON TOUGH OVER THE
ENTIRE AREA SO FAR TODAY. THE 31.12Z NAM SUGGESTS THE LOW LEVEL
MOISTURE WITH THESE CLOUDS WILL REMAIN OVER THE REGION THROUGH THE
NIGHT WHILE THE BUFKIT SOUNDINGS WOULD SUGGEST THE LOW CLOUDS
SHOULD BREAK UP YET THIS AFTERNOON OR EVENING. SATELLITE TRENDS
CERTAINLY DO NOT SUPPORT THE CLEARING OCCURRING AS FAST AS THE
SOUNDINGS WOULD SUGGEST SO HAVE GONE MORE PESSIMISTIC ON THE CLOUD
COVER HOLDING ON TO FOR MOST OF THE NIGHT. THE OTHER CONCERN FOR
TONIGHT IS WHETHER ANY STORMS ARE GOING TO DEVELOP OVER THE AREA
AS THE WARM FRONT LIFTS NORTH. CURRENT MODEL CONSENSUS SUGGESTS
THE WARM FRONT WILL MOVE FROM ITS CURRENT POSITION INTO CENTRAL
IOWA AND NORTHERN ILLINOIS OVERNIGHT. AS IT DOES...THE LOW LEVEL
JET WILL FORM WITH THE NOSE OF THE MOISTURE TRANSPORT IMPINGING ON
THE FRONT OVER EASTERN IOWA. SOME WEAK TO MODERATE FRONTOGENESIS
SHOULD OCCUR WITH THE FRONT IN THE 1000-700 MB LAYER AS FAR NORTH
AS NORTHEAST IOWA AND SOUTHWEST WISCONSIN. THIS AREA SHOULD ALSO
SEE BETWEEN 1 AND 3 UBAR/S OF UP GLIDE ON THE 305K ISENTROPIC
SURFACE. THIS FORCING COMBINED WITH THE MOISTURE TRANSPORT SHOULD
ALLOW SOME SHOWERS AND THUNDERSTORMS TO FORM ALONG AND NORTH OF
THE FRONT. THE POSITION OF THE FRONT LOOKS TO BE FARTHER SOUTH
THAN PREVIOUS RUNS HAVE SUGGESTED SO HAVE MOVED THE RAIN CHANCES
FARTHER SOUTH AND LOWERED THEM TO A 20 TO 30 PERCENT CHANCES
EXPECTING THE ACTIVITY TO PRIMARILY BE TO THE SOUTH OF THE AREA.
ANY CONVECTION THAT FORMS TONIGHT SHOULD MOVE QUICKLY OFF TO THE
EAST AS THE LOW LEVEL JET VEERS OFF TO THE SOUTHEAST. BY 12Z
SUNDAY WOULD EXPECT ALL THE ACTIVITY TO BE OUT OF THE AREA SO HAVE
REMOVED THE POPS FOR SUNDAY MORNING. AFTER THAT...THE WARM FRONT
WILL CONTINUE TO LIFT NORTH MAKING IT INTO CENTRAL MINNESOTA AND
WISCONSIN BY THE OF THE DAY. THE NAM AND 31.12Z GFS ARE IN GOOD
AGREEMENT ON THE POSITION OF THE BAROCLINIC ZONE WITH 850 MB
TEMPERATURES EXPECTED TO RANGE FROM ABOUT 10C ACROSS THE NORTH TO
17C IN THE SOUTHWEST. THE MIXING WILL NOT BE AS DEEP NORTH OF THE
FRONT WHICH WILL KEEP SURFACE TEMPERATURES IN THE UPPER 60S THERE
WHILE THE SOUTHWEST COULD SEE LOWER 80S WITH DEEPER MIXING.
THE NEXT CHANCE FOR SOME RAIN LOOKS TO ARRIVE STARTING SUNDAY
NIGHT AND CONTINUING THROUGH MONDAY NIGHT...ALTHOUGH THE MODELS
ARE NOT IN VERY GOOD AGREEMENT ON HOW THIS WILL PLAY OUT. THE
UPPER LEVEL RIDGE IS EXPECTED TO MOVE EAST OF THE AREA AS THE
SYSTEM COMING INTO THE WEST COAST SPLITS OVER THE ROCKIES WITH ONE
SHORT WAVE TROUGH TRACKING ACROSS SOUTHERN CANADA AND THE NORTHERN
UPPER MIDWEST WITH A SECOND SHORT WAVE TROUGH FORMING A CUT OFF
LOW AS IT DROPS INTO THE SOUTHERN PLAINS. THE GFS IS THE QUICKEST
TO PUSH THE RIDGE OUT OF THE AREA AS IT RAPIDLY PROGRESSES THE
NORTHERN STREAM SYSTEM ACROSS CANADA. AS A RESULT...IT PUSHES A
SURFACE COLD FRONT INTO THE AREA SUNDAY NIGHT AND ACROSS THE
REGION MONDAY AND MONDAY NIGHT. THE 31.00Z AND 31.12Z RUNS OF THE
ECMWF WERE THE SLOWEST TO PUSH THE RIDGE OUT OF THE AREA
SUGGESTING THIS MAY NOT OCCUR UNTIL MONDAY AFTERNOON OR NIGHT. THE
NAM WAS SOMEWHAT IN THE MIDDLE OF THESE SOLUTIONS. ONE THING ALL
THE MODELS DO AGREE ON IS THAT THE BEST FORCING WILL LIKELY SPLIT
THE AREA WITH THE NORTHERN PARTS OF THE FORECAST AREA JUST GETTING
BRUSHED WITH THE SOUTHERN EXTEND OF THE PV ADVECTION IN THE
500-300 MB LAYER AS THE NORTHERN STREAM SYSTEM PASSES BY. ONLY
MADE SOME MINOR ADJUSTMENTS FORM THE ONGOING FORECAST BY GOING
WITH A DRY FORECAST SUNDAY EVENING AND BRINGING IN A 20 PERCENT
CHANCE ACROSS THE NORTH SUNDAY NIGHT. NO SUBSTANTIAL CHANGES TO
MONDAY WITH 20 TO 30 PERCENT CHANCES FOR THE ENTIRE AREA AND THEN
HELD WITH A 30 TO 50 PERCENT CHANCE FROM WEST TO EAST MONDAY
NIGHT. IF THE SLOWER ECMWF SOLUTIONS PAN OUT...THESE RAIN CHANCES
WILL BE TOO HIGH WITH THE POTENTIAL FOR RAIN JUST ACROSS THE WEST
MONDAY AND PRIMARILY ACROSS THE NORTH MONDAY NIGHT.
.LONG TERM...TUESDAY THROUGH SATURDAY
301 PM CDT SAT MAR 31 2012
THE FRONT SHOULD CLEAR THE AREA ALLOWING THE RAIN TO BE CONFINED
TO AREAS EAST AND SOUTH OF THE REGION TUESDAY. AFTER THAT...HIGH
PRESSURE BUILDS IN AND REMAINS THROUGH FRIDAY. MODELS SHOWING
CONSIDERABLE VARIABILITY ON HOW FAST THE UPPER LEVEL RIDGE WILL
BREAK DOWN ALLOWING THE NEXT SYSTEM TO COME IN. THE 31.12Z GFS
BRINGS THIS SYSTEM IN FOR FRIDAY NIGHT AND SATURDAY WITH A COLD
FRONT WORKING ACROSS THE ARA. HOWEVER...LOOKING BACK AT ITS
PREVIOUS RUNS...IT HAS SHOWN NO CONTINUITY ON THE PLACEMENT OR
TIMING OF THE UPPER LEVEL TROUGH. THE 31.00Z ECMWF HAD SHOWN THIS
SYSTEM TO BE MUCH SLOWER REMAINING WEST OF THE AREA AND HAD GOOD
CONTINUITY WITH ITS PREVIOUS RUNS. THE NEW 12Z RUN CAME IN MUCH
QUICKER AND IN GOOD AGREEMENT WITH THE GFS. FOR NOW...WILL CARRY
SOME LOW RAIN CHANCES WITH THIS SYSTEM FOR FRIDAY NIGHT AND
SATURDAY.
&&
.AVIATION...TONIGHT AND SUNDAY
659 PM CDT SAT MAR 31 2012
ANOTHER NIGHT OF STRATUS ACROSS MUCH OF EASTERN MINNESOTA AND
IOWA...AND ALL OF WISCONSIN. MOSTLY A MIX OF MVFR CEILINGS ALONG
THE MISSISSIPPI RIVER...WITH IFR CIGS/VISIBILITIES ALONG THE I-35 CORRIDOR
IN MINNESOTA. LIGHT SOUTHEASTERLY FLOW OFF LAKE MICHIGAN HAS
REALLY KEPT INVERSION IN PLACE TODAY. FOR THIS EVENING...THE RUC
AND HRRR GUIDANCE SHOWS STATUS BREAKING UP AS SLIGHTLY DRIER AIR
IS PULLED IN FROM THE SOUTHEAST AND THIS COULD POTENTIALLY LEAD
TO CEILINGS RISING TO 2000 FT AT KRST AND 2500-3000 FT AT KLSE.
HOWEVER...NOT A LOT OF CONFIDENCE IN THIS SCENARIO...BUT WILL HAVE
TO MONITOR CLOSELY. AFTER MIDNIGHT...KEPT A LOWERING TREND TO IFR
CEILINGS AT KRST AT 04Z AND 09Z AT KLSE.
AS FOR FOG/LOW STRATUS POTENTIAL OVERNIGHT...THERE IS A SIMILAR
SETUP TO LAST NIGHT. GIVEN PLENTIFUL LOW-LEVEL MOISTURE AND LIGHT
WINDS...PLAN ON LOWERING CEILINGS/VISIBILITIES TO 400 FT/1SM AT
KRST AND 900 FT/4SM AT KLSE.
SINCE RECENT MODEL HANDLING OF FOG/STRATUS HAS BEEN POOR...PARTICULARLY
WHEN TRYING TO LIFT/BREAK UP FOG THE MORNING AFTER...REMAINED
PESSIMISTIC WITH ANY CLEARING TRENDS. BY AFTERNOON...INCREASING
SOUTHEASTERLY WINDS SHOULD MIX UP TO BETWEEN 2000-3000
FT...HELPING TO BREAK UP LOW-LEVEL CLOUDS...AND GIVE WAY TO HIGH-
LEVEL CLOUDS AROUND 15 KFT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
301 PM CDT SAT MAR 31 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...ZT
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
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 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 CHICAGO/ROMEOVILLE IL
406 AM CDT SUN APR 1 2012
.DISCUSSION...
315 AM CDT
THIS MORNING HIGH PRESSURE OVER THE EASTERN GREAT LAKES REGION WILL
PUSH EASTWARD WITH FRONTAL BOUNDARY SLOWLY TRYING TO LIFT NORTHWARD
THROUGH THE EARLY MORNING HOURS. ONGOING ELEVATED CONVECTION ON NOSE
OF LOW LEVEL JET WILL CONTINUE TO PUSH SOUTHEAST ACROSS THE REGION
RIDING H5 HEIGHTS DOWN THE RIDGE ALONG THE INSTABILITY GRADIENT.
SEVERE THREAT THROUGH THE PREDAWN HOURS WILL REMAIN MARGINAL...BUT
LATEST RUC CONTINUES TO SHOW NEAR 1000 J/KG GENERALLY ALONG AND WEST
OF THE I39 CORRIDOR SUPPORTING AT LEAST SOME THREAT FOR HAIL. THREAT
SHOULD TAPER THROUGH DAYBREAK THIS MORNING AS LOW LEVEL JET VEERS
AND THETA E ADVECTION WEAKENS. MEANWHILE...WEAK AREA OF LOW
PRESSURE NEAR LAKE SUPERIOR WILL PUSH EAST INTO SOUTHEASTERN
ONTARIO BY EARLY THIS AFTERNOON. GUIDANCE SUGGESTS BAROCLINIC ZONE
WILL BE FARTHER SOUTH/WEST THAN ORIGINALLY ANTICIPATED THUS BUMPED
DOWN TEMPERATURES SLIGHTLY ACROSS THE AREA FOR THIS AFTERNOON. IN
ADDITION WINDS TURNING TO THE NORTHEAST BY MID MORNING IN RESPONSE
TO LOW MOVING ACROSS ONTARIO WILL LIMIT HIGH TEMPS ALONG THE LAKE
SHORE...WITH TEMPERATURES FALLING INLAND THROUGH THE AFTERNOON AS
MARINE LAYER SPREADS INLAND.
MONDAY...GUIDANCE CONTINUES TO STRUGGLE WITH PLACEMENT OF BAROCLINIC
ZONE/LOW PRESSURE. A LARGE TEMPERATURE SPREAD IS STILL EXPECTED TO
SET UP ACROSS THE CWA. MAJORITY OF GUIDANCE SHOWS SOUTHWEST PORTIONS
OF THE CWA TRYING TO REACHING THE 80 MARK...BUT WARMER TEMPERATURES
ARE NOW EXPECTED TO BE FARTHER WEST. ALSO HAD TO DROP TEMPERATURES
ALONG THE LAKE FRONT SEVERAL DEGREES AS LATEST GUIDANCE IN GENERAL
SUGGESTS 60S POSSIBLY EVEN 50S AS WE STAY UNDER SOUTHEAST FLOW
THROUGH THE DAY WITH WINDS OFF THE LAKE IN ILLINOIS. AM CONCERNED
TEMPS ARE STILL A LITTLE HIGH THOUGH FOR MONDAY ALONG THE ILLINOIS
SHORES.
TUESDAY THOUGH SATURDAY...COLD FRONT WILL SWEEP ACROSS THE REGION
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS.
BROAD AREA OF HIGH PRESSURE BUILDS ACROSS THE CANADIAN PRAIRIES EAST
TOWARDS THE GREAT LAKE REGION THROUGH THE END OF THE WEEK. NORTHERN
ILLINOIS AND NORTHWEST INDIANA WILL BE IN AREA OF NORTHERLY FLOW AND
EXPECT TO BE CLIPPED BY COOLER AIR ALOFT //H85 TEMPS FALLING TO
AROUND -3C THURSDAY// BEHIND THE COLD FRONT. SHOULD SEE PLENTY OF
SUNSHINE FOR THE LATTER HALF OF THE WEEK. TEMPERATURES WILL CONTINUE
TO RUN SLIGHTLY ABOVE NORMAL...BUT SHOULD BE MORE SEASONABLE WITH
HIGHS IN THE UPPER 50S TO LOW 60S AND LOWS IN THE UPPER 30S TO LOW
40S. BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* SCATTERED BANDS OF TSRA APPROACHING FROM THE WEST AROUND 10Z.
INTERMITTENT TSRA EXPECTED UNTIL AROUND 12Z...POSSIBLY LINGERING
TIL 13-14Z IF NEW DEVELOPMENT ON THE REAR FLANK.
* WIND SHIFT TO NORTHEAST BY LATE MORNING/MID-DAY. WINDS MAY
BECOME LIGHT AND VARIABLE FOR A FEW HOURS AS THIS OCCURS.
* POTENTIAL FOR PERIOD OF MVFR CEILINGS 1500-2000 FT LATE MORNING
TO MID-AFTERNOON.
MDB
//DISCUSSION...UPDATED 09Z...
BAND OF CLUSTERED SHRA/TSRA CONTINUES TO MOVE EASTWARD INTO THE
FAR WESTERN CHI METRO AREA AT 09Z. THIS WILL CONTINUE TO MOVE
EASTWARD OVER THE NEXT SEVERAL HOURS BRINGING BRIEF HEAVY
DOWNPOURS AND IFR/MVFR VSBY. SOME ADDITIONAL DEVELOPMENT MAY OCCUR
IMMEDIATELY BEHIND THE CURRENT BAND PROLONGING THE DURATION
SOMEWHAT.
MDB
FROM 06Z...
INITIAL CONCERN THIS MORNING IS WITH POTENTIAL FOR THUNDERSTORMS
TO AFFECT TERMINALS DURING THE PRE-DAWN HOURS. AREA OF ELEVATED
CONVECTION OVER FAR WESTERN IL AND NORTHEAST IA IS SLOWLY
PROPAGATING TO THE EAST-SOUTHEAST AND WOULD LIKELY SKIRT SOUTH OF
TERMINALS LATER THIS AM. NEW DEVELOPMENT CONTINUES TO OCCUR ON THE
NORTHERN FRINGE OF THE CONVECTIVE COMPLEX ACROSS NORTHEAST IA
HOWEVER...AND SEVERAL HIGH RES EXPLICIT CONVECTION MODELS CONTINUE
TO DEPICT CONTINUED DEVELOPMENT INTO FAR NORTHERN IL TOWARD
09-10Z. THEREFORE HAVE MAINTAINED A BRIEF TEMPO MENTION FOR TS
WITH SOME MINOR TIMING ADJUSTMENTS BASED ON RADAR EXTRAPOLATION
PARTICULARLY FOR KRFD.
ONCE MORNING STORMS MOVE OFF TO THE EAST...NEXT CONCERN IS WINDS
SHIFTING TO THE NORTHEAST AND THE POTENTIAL FOR A PERIOD OF MVFR
CEILINGS. GUIDANCE CONTINUES TO INDICATE WIND SHIFT BY VERY LATE
MORNING/MID-DAY AS WEAK SURFACE WAVE MOVES EAST AND REINFORCING
COLD FRONT SAGS SOUTH ACROSS TERMINALS. FORECAST SOUNDINGS DEPICT
MOIST LAYER 1500-2000 FT IN COOL ADVECTION BENEATH INVERSION
ALOFT. FORECAST SOUNDINGS INDICATE ENOUGH DRYING TAKES PLACE BY
MID-LATE AFTERNOON TO SCATTER CLOUDS.
WINDS...SOUTHEAST LESS THAN 10 KTS AT TAF ISSUANCE EXPECTED TO
BECOME SOUTH OVERNIGHT...THEN LIGHT WESTERLY AFTER SUNRISE.
AFOREMENTIONED FRONT THEN SAGS THROUGH WITH SHIFT TO THE NORTHEAST
BY LATE MORNING OR SO...WITH GUSTS TO 15 KT POSSIBLE IN DEEPER
MIXING WITH LOW LEVEL COLD ADVECTION.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH CONFIDENCE IN TSRA AFFECTING THE IMMEDIATE TERMINAL AREAS
APPROX 10-12Z...WITH LOW CONFIDENCE IN POTENTIAL FOR NEW
DEVELOPMENT IMMEDIATELY BEHIND CURRENT ACTIVITY PROLONGING
IMPACT.
* HIGH CONFIDENCE IN WIND TRENDS THROUGH PERIOD.
* MEDIUM CONFIDENCE IN PERIOD OF 1500-2000 FT CIGS LATE MORNING INTO
THIS AFTERNOON.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR WITH CHANCE TSRA MONDAY NIGHT.
TUESDAY...VFR WITH CHANCE SHRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
RATZER
&&
.MARINE...
210 AM CDT
HIGH PRESSURE OVER OHIO EXTENDS NORTHEASTWARD ACROSS THE ST.
LAWRENCE VALLEY THIS MORNING WHILE A COMPLEX SERIES OF WEAK LOW
PRESSURE SYSTEMS ARE NOTED FROM LAKE SUPERIOR INTO THE MID
MISSISSIPPI RIVER VALLEY...WITH BETTER ORGANIZED LOW PRESSURE IN THE
LEE OF THE ROCKIES. ONE LOW...OVER LAKE SUPERIOR...WILL MOVE
SOUTHEASTWARD TODAY AND MOVE OFF THE EAST COAST THIS EVENING WHERE
IT WILL DEEPEN. ANOTHER AREA OF LOW PRESSURE OVER WESTERN IOWA
WILL DRIFT EAST WITH A COOL FRONTAL BOUNDARY SETTING UP FROM THE
FIRST LOW INTO THIS WEAKER LOW. HIGH PRESSURE WILL THEN SPREAD
SOUTHWARD FROM HUDSON BAY AND INTO THE GREAT LAKES BEHIND THE
LOW. AS A RESULT OF THIS FAIRLY COMPLEX PATTERN SOUTHERLY WINDS IN
PLACE ACROSS LAKE MICHIGAN THIS MORNING WILL TURN NORTHEASTERLY
TODAY AND EASTERLY TONIGHT...BEFORE BECOMING SOUTHEAST FOR MONDAY.
IT APPEARS THAT THERE WILL BE SEVERAL PERIODS OF STRONGER WINDS
FROM TONIGHT THROUGH TUESDAY AS THE PRESSURE GRADIENT MODULATES
BETWEEN SYSTEMS. THE FIRST INCREASE SHOULD OCCUR TONIGHT ACROSS
CENTRAL AND SOUTHERN PARTS OF THE LAKE WITH GUSTS TO AROUND 25 KT
EXPECTED. SPEEDS LOOK TO EASE SOMEWHAT MONDAY BEFORE INCREASING
AGAIN MONDAY EVENING THEN DROPPING OFF TUESDAY MORNING AS A LOW
PASSES JUST TO THE SOUTH. THE GRADIENT TIGHTENS BEHIND THE LOW
TUESDAY AFTERNOON AS STRONG HIGH PRESSURE SPREADS INTO THE UPPER
MISSISSIPPI RIVER VALLEY. THIS LOOKS TO BE THE PERIOD OF STRONGEST
WINDS WITH 30 KT POSSIBLE FROM THE NORTH. THE HIGH THEN GRADUALLY
SPREADS EASTWARD KEEPING ITS INFLUENCE OVER THE LAKE THROUGH THE
END OF THE WEEK. LOWS WILL PASS TO THE EAST AND SOUTH OF THE LAKE
SO PERIODS OF SLIGHTLY STRONGER WINDS WILL BE POSSIBLE DESPITE THE
PRESENCE OF THE HIGH...BUT HIGHEST SPEEDS LOOK TO BE UNDER 20 KTS
OR SO FROM MID WEEK ONWARD.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
320 AM CDT SUN APR 1 2012
.DISCUSSION...
315 AM CDT
THIS MORNING HIGH PRESSURE OVER THE EASTERN GREAT LAKES REGION WILL
PUSH EASTWARD WITH FRONTAL BOUNDARY SLOWLY TRYING TO LIFT NORTHWARD
THROUGH THE EARLY MORNING HOURS. ONGOING ELEVATED CONVECTION ON NOSE
OF LOW LEVEL JET WILL CONTINUE TO PUSH SOUTHEAST ACROSS THE REGION
RIDING H5 HEIGHTS DOWN THE RIDGE ALONG THE INSTABILITY GRADIENT.
SEVERE THREAT THROUGH THE PREDAWN HOURS WILL REMAIN MARGINAL...BUT
LATEST RUC CONTINUES TO SHOW NEAR 1000 J/KG GENERALLY ALONG AND WEST
OF THE I39 CORRIDOR SUPPORTING AT LEAST SOME THREAT FOR HAIL. THREAT
SHOULD TAPER THROUGH DAYBREAK THIS MORNING AS LOW LEVEL JET VEERS
AND THETA E ADVECTION WEAKENS. MEANWHILE...WEAK AREA OF LOW
PRESSURE NEAR LAKE SUPERIOR WILL PUSH EAST INTO SOUTHEASTERN
ONTARIO BY EARLY THIS AFTERNOON. GUIDANCE SUGGESTS BAROCLINIC ZONE
WILL BE FARTHER SOUTH/WEST THAN ORIGINALLY ANTICIPATED THUS BUMPED
DOWN TEMPERATURES SLIGHTLY ACROSS THE AREA FOR THIS AFTERNOON. IN
ADDITION WINDS TURNING TO THE NORTHEAST BY MID MORNING IN RESPONSE
TO LOW MOVING ACROSS ONTARIO WILL LIMIT HIGH TEMPS ALONG THE LAKE
SHORE...WITH TEMPERATURES FALLING INLAND THROUGH THE AFTERNOON AS
MARINE LAYER SPREADS INLAND.
MONDAY...GUIDANCE CONTINUES TO STRUGGLE WITH PLACEMENT OF BAROCLINIC
ZONE/LOW PRESSURE. A LARGE TEMPERATURE SPREAD IS STILL EXPECTED TO
SET UP ACROSS THE CWA. MAJORITY OF GUIDANCE SHOWS SOUTHWEST PORTIONS
OF THE CWA TRYING TO REACHING THE 80 MARK...BUT WARMER TEMPERATURES
ARE NOW EXPECTED TO BE FARTHER WEST. ALSO HAD TO DROP TEMPERATURES
ALONG THE LAKE FRONT SEVERAL DEGREES AS LATEST GUIDANCE IN GENERAL
SUGGESTS 60S POSSIBLY EVEN 50S AS WE STAY UNDER SOUTHEAST FLOW
THROUGH THE DAY WITH WINDS OFF THE LAKE IN ILLINOIS. AM CONCERNED
TEMPS ARE STILL A LITTLE HIGH THOUGH FOR MONDAY ALONG THE ILLINOIS
SHORES.
TUESDAY THOUGH SATURDAY...COLD FRONT WILL SWEEP ACROSS THE REGION
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS.
BROAD AREA OF HIGH PRESSURE BUILDS ACROSS THE CANADIAN PRAIRIES EAST
TOWARDS THE GREAT LAKE REGION THROUGH THE END OF THE WEEK. NORTHERN
ILLINOIS AND NORTHWEST INDIANA WILL BE IN AREA OF NORTHERLY FLOW AND
EXPECT TO BE CLIPPED BY COOLER AIR ALOFT //H85 TEMPS FALLING TO
AROUND -3C THURSDAY// BEHIND THE COLD FRONT. SHOULD SEE PLENTY OF
SUNSHINE FOR THE LATTER HALF OF THE WEEK. TEMPERATURES WILL CONTINUE
TO RUN SLIGHTLY ABOVE NORMAL...BUT SHOULD BE MORE SEASONABLE WITH
HIGHS IN THE UPPER 50S TO LOW 60S AND LOWS IN THE UPPER 30S TO LOW
40S. BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* COVERAGE/TIMING OF THUNDERSTORMS EARLY THIS MORNING.
* WIND SHIFT TO NORTHEAST BY LATE MORNING/MID-DAY.
* POTENTIAL FOR PERIOD OF MVFR CEILINGS 1500-2000 FT LATE MORNING
TO MID-AFTERNOON.
RATZER
//DISCUSSION...UPDATED 06Z...
INITIAL CONCERN THIS MORNING IS WITH POTENTIAL FOR THUNDERSTORMS
TO AFFECT TERMINALS DURING THE PRE-DAWN HOURS. AREA OF ELEVATED
CONVECTION OVER FAR WESTERN IL AND NORTHEAST IA IS SLOWLY
PROPAGATING TO THE EAST-SOUTHEAST AND WOULD LIKELY SKIRT SOUTH OF
TERMINALS LATER THIS AM. NEW DEVELOPMENT CONTINUES TO OCCUR ON THE
NORTHERN FRINGE OF THE CONVECTIVE COMPLEX ACROSS NORTHEAST IA
HOWEVER...AND SEVERAL HIGH RES EXPLICIT CONVECTION MODELS CONTINUE
TO DEPICT CONTINUED DEVELOPMENT INTO FAR NORTHERN IL TOWARD
09-10Z. THEREFORE HAVE MAINTAINED A BRIEF TEMPO MENTION FOR TS
WITH SOME MINOR TIMING ADJUSTMENTS BASED ON RADAR EXTRAPOLATION
PARTICULARLY FOR KRFD.
ONCE MORNING STORMS MOVE OFF TO THE EAST...NEXT CONCERN IS WINDS
SHIFTING TO THE NORTHEAST AND THE POTENTIAL FOR A PERIOD OF MVFR
CEILINGS. GUIDANCE CONTINUES TO INDICATE WIND SHIFT BY VERY LATE
MORNING/MID-DAY AS WEAK SURFACE WAVE MOVES EAST AND REINFORCING
COLD FRONT SAGS SOUTH ACROSS TERMINALS. FORECAST SOUNDINGS DEPICT
MOIST LAYER 1500-2000 FT IN COOL ADVECTION BENEATH INVERSION
ALOFT. FORECAST SOUNDINGS INDICATE ENOUGH DRYING TAKES PLACE BY
MID-LATE AFTERNOON TO SCATTER CLOUDS.
WINDS...SOUTHEAST LESS THAN 10 KTS AT TAF ISSUANCE EXPECTED TO
BECOME SOUTH OVERNIGHT...THEN LIGHT WESTERLY AFTER SUNRISE.
AFOREMENTIONED FRONT THEN SAGS THROUGH WITH SHIFT TO THE NORTHEAST
BY LATE MORNING OR SO...WITH GUSTS TO 15 KT POSSIBLE IN DEEPER
MIXING WITH LOW LEVEL COLD ADVECTION.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE THUNDERSTORMS WILL AFFECT TRACON AIRSPACE...BUT
MEDIUM CONFIDENCE IN DIRECT IMPACT ON INDIVIDUAL TERMINALS.
* HIGH CONFIDENCE IN WIND TRENDS THROUGH PERIOD.
* MEDIUM CONFIDENCE IN PERIOD OF 1500-2000 FT CIGS LATE MORNING INTO
THIS AFTERNOON.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR WITH CHANCE TSRA MONDAY NIGHT.
TUESDAY...VFR WITH CHANCE SHRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
RATZER
&&
.MARINE...
210 AM CDT
HIGH PRESSURE OVER OHIO EXTENDS NORTHEASTWARD ACROSS THE ST.
LAWRENCE VALLEY THIS MORNING WHILE A COMPLEX SERIES OF WEAK LOW
PRESSURE SYSTEMS ARE NOTED FROM LAKE SUPERIOR INTO THE MID
MISSISSIPPI RIVER VALLEY...WITH BETTER ORGANIZED LOW PRESSURE IN THE
LEE OF THE ROCKIES. ONE LOW...OVER LAKE SUPERIOR...WILL MOVE
SOUTHEASTWARD TODAY AND MOVE OFF THE EAST COAST THIS EVENING WHERE
IT WILL DEEPEN. ANOTHER AREA OF LOW PRESSURE OVER WESTERN IOWA
WILL DRIFT EAST WITH A COOL FRONTAL BOUNDARY SETTING UP FROM THE
FIRST LOW INTO THIS WEAKER LOW. HIGH PRESSURE WILL THEN SPREAD
SOUTHWARD FROM HUDSON BAY AND INTO THE GREAT LAKES BEHIND THE
LOW. AS A RESULT OF THIS FAIRLY COMPLEX PATTERN SOUTHERLY WINDS IN
PLACE ACROSS LAKE MICHIGAN THIS MORNING WILL TURN NORTHEASTERLY
TODAY AND EASTERLY TONIGHT...BEFORE BECOMING SOUTHEAST FOR MONDAY.
IT APPEARS THAT THERE WILL BE SEVERAL PERIODS OF STRONGER WINDS
FROM TONIGHT THROUGH TUESDAY AS THE PRESSURE GRADIENT MODULATES
BETWEEN SYSTEMS. THE FIRST INCREASE SHOULD OCCUR TONIGHT ACROSS
CENTRAL AND SOUTHERN PARTS OF THE LAKE WITH GUSTS TO AROUND 25 KT
EXPECTED. SPEEDS LOOK TO EASE SOMEWHAT MONDAY BEFORE INCREASING
AGAIN MONDAY EVENING THEN DROPPING OFF TUESDAY MORNING AS A LOW
PASSES JUST TO THE SOUTH. THE GRADIENT TIGHTENS BEHIND THE LOW
TUESDAY AFTERNOON AS STRONG HIGH PRESSURE SPREADS INTO THE UPPER
MISSISSIPPI RIVER VALLEY. THIS LOOKS TO BE THE PERIOD OF STRONGEST
WINDS WITH 30 KT POSSIBLE FROM THE NORTH. THE HIGH THEN GRADUALLY
SPREADS EASTWARD KEEPING ITS INFLUENCE OVER THE LAKE THROUGH THE
END OF THE WEEK. LOWS WILL PASS TO THE EAST AND SOUTH OF THE LAKE
SO PERIODS OF SLIGHTLY STRONGER WINDS WILL BE POSSIBLE DESPITE THE
PRESENCE OF THE HIGH...BUT HIGHEST SPEEDS LOOK TO BE UNDER 20 KTS
OR SO FROM MID WEEK ONWARD.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
302 AM CDT SUN APR 1 2012
.DISCUSSION...
ISSUED 300 AM CDT SUN APR 1 2012
SMALL MCS FORMED AS EXPECTED OVER EASTERN IOWA LATE IN THE
EVENING...AND HAS BEEN MOVING ACROSS THE NORTHERN CWA
OVERNIGHT...PRODUCING SEVERE HAIL AT TIMES. HAVE SEEN SOME
SHOWERS/STORMS AS FAR SOUTH AS LINCOLN AT 2 AM.
SHORT TERM...TODAY THROUGH TUESDAY...
LATEST HRRR MODEL...WHICH HAS A GOOD HANDLE ON THE ACTIVITY...
SHOWS MUCH OF THE RAIN SHOULD LARGELY BE OUT OF THE CWA BY
SUNRISE. WILL MAKE A LAST MINUTE DECISION ON HOW LONG TO LINGER IT
THIS MORNING. ONCE THAT CLEARS OUT...TEMPERATURES BECOME THE
PRIMARY FOCUS. STILL LOOKING FOR HIGHS IN THE 80S ACROSS THE
ENTIRE AREA...CLOSE TO THE DAILY RECORDS. HOWEVER...EVENING MODEL
RUNS SHOWING A FRONTAL BOUNDARY NEAR THE I-80 CORRIDOR WILL LIKELY
SLIP A BIT SOUTHWARD THIS AFTERNOON...DRIVEN BY A RATHER STIFF
NORTHEAST FLOW. IF IT SLIPS TOO FAR...THEN TEMPERATURES ACROSS THE
NORTHEAST CWA MAY END UP BEING COOLER THAN EXPECTED. WRF MODEL OUT
OF WFO CHICAGO HAS THE BOUNDARY ALMOST ALL THE WAY TO I-74 BY
6 PM. WILL NEED TO WATCH THIS CLOSELY DURING THE AFTERNOON.
BOUNDARY WILL PROBABLY REACH AT LEAST INTO PART OF THE CWA THIS
EVENING...BEFORE BEGINNING TO RETREAT. SAME PROBLEM EXISTS WITH
TEMPERATURES MONDAY AFTERNOON...DUE TO ITS POSITION. HAVE PULLED
HIGH TEMPERATURES DOWN A BIT NORTH OF I-74...BUT STILL GOING A FEW
DEGREES ABOVE GUIDANCE IN THAT AREA. REMAINDER OF THE CWA MORE
LIKELY TO REACH THE 85-90 DEGREE RANGE...AGAIN NEAR THE RECORDS.
TIMING OF COLD FRONTAL PASSAGE TUESDAY MORNING APPEARS TO HAVE
SLOWED A BIT FROM EARLIER RUNS...SO HAVE KEPT TEMPERATURES SOUTH
OF I-70 WARMER THAN PREVIOUSLY FORECAST...WITH LOWER 80S.
THREAT OF SHOWERS/STORMS TO CONTINUE INTO THE AFTERNOON WITH THE
BOUNDARY IN THE AREA.
LONG TERM...WEDNESDAY THROUGH SATURDAY...
STILL LOOKING TO BE MUCH COOLER THAN THE START OF THE WEEK...ALTHOUGH
STILL A BIT ABOVE NORMAL. FOCUS IN THIS PERIOD REMAINS WITH A
CUTOFF LOW WHICH WILL DEVELOP OVER THE SOUTHERN ROCKIES EARLY IN
THE WEEK. LONGER RANGE MODELS IN REASONABLE AGREEMENT WITH A TRACK
THAT TAKES IT SOUTH OF THE OHIO VALLEY...BUT WILL STILL SEE THE
RAIN SHIELD ON THE NORTHERN FLANK EXTEND WELL TO THE NORTH. HAVE
CUT BACK ON THE RAIN ACROSS THE NORTHERN CWA FOR WEDNESDAY/THURSDAY...
WITH THE PERSISTENT NORTHEAST FLOW BRINGING DRIER AIR INTO CENTRAL
ILLINOIS. MAINLY DRY CONDITIONS EXPECTED LATE IN THE WEEK...AS A
NARROW RIDGE OF HIGH PRESSURE MOVES INTO THE MISSISSIPPI VALLEY.
GEELHART
&&
.AVIATION...
ISSUED 1240 AM CDT SUN APR 1 2012...FOR THE 06Z TAFS
STORMS WILL PUSH ACROSS PIA/BMI/CMI BETWEEN 06Z AND 09Z...WITH
MVFR VIS IN HEAVY RAIN AND SMALL HAIL. BASED ON UPSTREAM OBS
DURING STORMS...CIGS SHOULD REMAIN VFR DURING THE STORMS. WIND
GUSTS UP TO 35 MPH ARE POSSIBLE. LIGHTER RAIN AND MORE ISOLATED
THUNDERSTORMS ARE PROJECTED TO REACH THE SOUTHERN TERMINALS OF
SPI/DEC. STILL BRIEF PERIODS OF MVFR VIS IN RAIN IS POSSIBLE. WE
DID NOT INCLUDE TEMPOS FOR MVFR AT SPI/DEC WITH THE INITIAL
ISSUANCE...AS WE EXPECT THE LINE OF STORMS TO WEAKEN AS IT
PROGRESSES FARTHER FROM THE FAVORABLE WIND SHEAR...LLJ...AND
INSTABILITY.
SKIES ARE EXPECTED TO CLEAR RELATIVELY QUICKLY BEHIND THE LINE OF
SHOWERS/STORMS. A PERIOD OF MVFR VIS IN FOG MAY DEVELOP IN
PIA/BMI/CMI IF ANY CLEARING DEVELOPS BEFORE SUNRISE. FOG WOULD
CLEAR TO VFR BY 15Z IN THAT SCENARIO.
WINDS WILL VEER FROM SOUTHEAST TO SOUTHWEST BETWEEN 10Z-14Z...THEN
REMAIN SOUTHWEST UNTIL A BACK DOOR COLD FRONT REACHES NEAR
PIA/BMI/CMI TOWARD 06Z. THEN WINDS WILL BACK TO THE EAST BEHIND
THAT FRONT.
SHIMON
&&
.CLIMATE...
ISSUED 218 AM CDT SUN APR 1 2012
RECORD HIGHS FOR TODAY...MONDAY...
BLOOMINGTON......82/1981...85/1903
CHAMPAIGN........83/1946...81/1932
DECATUR..........87/1946...85/1940
EFFINGHAM........83/1986...82/2010
JACKSONVILLE.....85/1946...85/1903
LINCOLN..........85/1946...84/1940
OLNEY............85/1946...85/1940
PEORIA...........83/1946...84/1940
SPRINGFIELD......87/1946...87/1981
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
214 AM CDT SUN APR 1 2012
.DISCUSSION...
908 PM CDT
SOME MINOR CHANGES TO POPS AND WX FOR TONIGHT. MAINLY DELAYING
ARRIVAL OF THREAT OF SHRA AND TSRA UNTIL LATER TONIGHT AND
REDUCING POPS OVER FAR NE IL FOR OVERNIGHT.
RADAR COMPOSITE SHOWS WEAK ECHOES TO THE W THRU N OF THE LOCAL
AREA WHERE INITIAL WAA AND RESULTING UVV AT MAINLY MID LEVELS
OCCURRING. EXPECT THESE ECHOES...ALREADY MOSTLY VIRGA UPSTREAM
WITH FEW IF ANY METARS REPORTING ANY PRECIP...WILL CONTINUE TO
DRY UP AS THEY MOVE INTO INCREASINGLY DRY MID AND LOW LEVELS.
A THUNDERSTORM DEVELOPED JUST NE OF DSM AROUND 0030Z AND ARE
SLOWLY INCREASING IN NUMBER AS THEY MOVE ENE-E. THESE TSRA ARE
WHERE BETTER MOISTURE IN THE 850 TO 800 HPA LAYER IS IN
PLACE...WHERE WEAK SURFACE CONVERGENCE IS OCCURRING...WHERE NOSE
OF 45 KT SOUTHWESTERLY JET AT 5 TO 6 K FT AGL SHOWN BY KDMX VAD
WIND PROFILE IS LOCATED...AND JUST AHEAD OF WEAK MID LEVEL SHORT
WAVE TROF MOVING OVER CENTRAL IA.
CHALLENGE TO FORECAST IS HOW EXTENSIVE FURTHER TSRA DEVELOPMENT
WILL BE AND WHERE AREA OF STORMS IS LIKELY TO MOVE OVERNIGHT.
LATEST RUC13 RUN INDICATES A RATHER SMALL AREA OF MID LEVEL
ISENTROPIC LIFT CURRENTLY OVER CENTRAL IA MOVES THIS AREA
EASTWARD TO E CENTRAL IA 04-06Z...AND THEN SOUTHEASTWARD ACROSS
N CENTRAL IL TO THE CENTRAL IL-IND BORDER BY 12Z. THIS APPEARS TO
BE BEST TRACK FOR THE ELEVATED TSRA THAT IS EXPECTED TO BE
MAINTAINED THROUGH THE OVERNIGHT BY THE LLJ...THE MID LEVEL SHORT
WAVE AND STEEPENING MID LEVEL LAPSE RATES.
EXPECT RATHER SMALL AREA OF TSRA AS MOISTURE WILL BE MARGINAL SO
ONLY ANTICIPATE ACTIVITY WHERE FORCING FACTORS ARE MAXIMIZED
DURING THE OVERNIGHT.
TRS
//PREV DISCUSSION...
317 PM CDT
MAIN FORECAST ISSUES/CONCERNS FOR THE REMAINDER OF THE WEEKEND ARE
WITH CHANCES FOR SHOWERS/THUNDERSTORMS LATE TONIGHT INTO SUNDAY
MORNING...AS WELL AS TEMPERATURE TRENDS SUNDAY.
WITH THE LOW LEVEL CLOUD COVER TODAY MASKING THE FACT THAT HIGH
PRESSURE IS OVERHEAD...RELATIVELY QUIET CONDITIONS HAVE BEEN IN
PLACE FOR ALL OF TODAY. ALTHOUGH...OVER THE LAST COUPLE OF HOURS
SEVERAL HOLES DEVELOPED WITHIN THIS LOW LEVEL MOISTURE. A WARM SUN
AND DRIER AIR ALOFT HAS ALLOWED FOR THESE HOLES TO CONTINUE TO
EXPAND WITH SOME AREAS ACROSS THE SOUTHERN CWA OBSERVING SUNNY TO
PARTLY CLOUDY SKIES. WITHIN THESE AREAS OF BETTER SOLAR
INSOLATION...TEMPS HAVE QUICKLY RISEN INTO THE 50S WITH SOME AREAS
OBSERVING SOME PLEASANT CONDITIONS AS RATHER LIGHT FLOW REMAINS IN
PLACE. EXPECT THIS LOW CLOUD SHIELD TO CONTINUE TO ERODE WITH TIME
LATE THIS AFTERNOON AND EARLY EVENING BUT WITH SOME MID AND HIGH
LEVEL CLOUD COVER TO PUSH OVERHEAD. THIS IN ITSELF SHOULD PROVIDE
PARTLY CLOUDY SKIES FOR TONIGHT...BUT WITH PRECIP CHANCES LATER
TONIGHT TO POSSIBLY BRING MORE CLOUDY CONDITIONS MORE TOWARDS
EARLY SUNDAY MORNING.
LATEST GUIDANCE CONTINUES TO INDICATE SHOWERS AND THUNDERSTORMS
DEVELOPING TONIGHT ACROSS EASTERN IOWA AND SHIFTING EAST/SOUTHEAST
ACROSS A PORTION OF THE CWA THROUGH SUNDAY MORNING. ALL GUIDANCE
IS INDICATING THIS POSSIBILITY BUT WITH SOME VARIABILITY STILL
REMAINING WITH REGARDS TO EXACT TIMING AND PLACEMENT/TRACK. WITH
BACKING 850MB FLOW...A WARMER AND MORE MOIST AIR MASS LOCATED
ACROSS THE CENTRAL PLAINS WILL ADVECT NORTH/NORTHEAST WITH TIME
TONIGHT BRINGING HIGHER DEW POINT AIR TO THE REGION. NORTHWEST FLOW
ALOFT WILL STEER A MID LEVEL IMPULSE AND ATTENDANT SURFACE TROUGH
OUT OF THE NORTHERN PLAINS THIS EVENING...AND HELP TO INITIATE
CONVECTION ALONG A LOW LEVEL BAROCLINIC ZONE DRAPED ACROSS THE
REGION. WITH LOW LEVEL FLOW FEEDING HIGHER THETA E AIR OVER THIS
BOUNDARY AND INTO ANY DEVELOPING PRECIP...THIS AREA OF CONVECTION
COULD SEE SOME EXPANSION IN COVERAGE AS IT SHIFTS EAST/SOUTHEAST
THROUGH THE CWA EARLY SUNDAY MORNING. ALTHOUGH...GUIDANCE
CONTINUES TO STRUGGLE WITH EXACT TIMING OF WHEN CONVECTION WILL
DEVELOP AND WHERE THIS DEVELOPING AREA OF PRECIPITATION WILL
PROGRESS THROUGH. DUE TO THIS UNCERTAINTY STILL IN PLACE...HAVE
NOT MADE MANY CHANGES TO THE GOING POP GRIDS FOR TONIGHT KEEPING
HIGH CHANCE POPS FOR MUCH OF THE CWA AFTER THE MIDNIGHT TIME FRAME
THROUGH MID MORNING SUNDAY. THIS IS BASED ON THE LIKELIHOOD THAT
CONVECTION SHOULD BEGIN TO DEVELOP OVER IOWA ONCE WE DECOUPLE AND
THE LLJ RAMPS UP...WHICH SHOULD BE AROUND THE 3Z-6Z TIME FRAME.
SOME HI RES DATA IS SHOWING THE POSSIBILITY OF AN MCS DEVELOPING
AND QUICKLY SHIFTING THROUGH THE REGION SUNDAY MORNING. HAVE NOT
COMPLETELY THROWN THIS OUT AS A POSSIBILITY...WITH DECENT LOW
LEVEL SHEAR TO BE PRESENT ACROSS THE REGION. A LIMITING FACTOR
WILL BE THE AMOUNT OF INSTABILITY PRESENT OVER NORTHERN ILLINOIS
AND NORTHWEST...WHICH AM CURRENTLY LEANING MORE ON THE SREF MUCAPE
OUTPUT WHICH IS SHOWING WEAKER INSTABILITY PRESENT BY EARLY SUNDAY
MORNING LIMITING MORE ROBUST CONVECTION...WITH OTHER GUIDANCE OF
COURSE ALSO VARYING TO THIS AMOUNT. SO WITH ANY PRECIP WHICH MOVES
THROUGH THE AREA LATE TONIGHT AND EARLY SUNDAY MORNING...A MORE
LIKELY SCENARIO WILL BE FOR THIS TO BE AN UNORGANIZED AREA OF
SHOWERS AND ELEVATED THUNDERSTORMS WITH LITTLE CHANCES FOR SEVERE
WEATHER...HAIL/WIND. ONLY AN ISOLATED THREAT OF HAIL COULD BE
OBSERVED MAINLY FOR THE WESTERN CWA WHERE BETTER INSTABILITY AND
STRONGER EFFECTIVE BULK SHEAR WILL RESIDE. EVEN IF A MORE
ORGANIZED MCS COULD DEVELOP...WOULD EXPECT IT TO FOLLOW THE HIGHER
SURFACE DEW POINT AIR AND BETTER INSTABILITY WHICH WOULD MORE THAN
LIKELY BE SITUATED TO THE SOUTH OF THE CWA. THUS...ONCE AGAIN
KEEPING ANY THREAT FOR SEVERE WEATHER JUST OUTSIDE OF THE CWA.
THIS SITUATION WARRANTS CONTINUED MONITORING...AND WILL MAINTAIN A
MENTION FOR THE CHANCES FOR THUNDERSTORMS TONIGHT IN THE HWO.
ANY LINGERING SHOWERS/THUNDERSTORMS SHOULD EXIT THE CWA BY MID DAY
WITH PARTLY CLOUDY TO SUNNY CONDITIONS EXPECTED THROUGH THE
AFTERNOON. THE EXTENT OF THE MORNINGS PRECIP WILL DEFINITELY PLAY
A KEY ROLE WITH MAX TEMPS ON SUNDAY WITH PERSISTENT WAA ADVECTING
A WARMER AIR MASS OVERHEAD. AS SURFACE WARM FRONT TRIES TO LIFT
NORTHEAST ACROSS THE CWA DURING THE DAY SUNDAY...IT WILL ACTUALLY
BEGIN TO RETREAT AS A COLD FRONT WITH COOLER LOW LEVEL AIR WORKING
ITS WAY BACK WEST ACROSS THE CWA LATE IN THE AFTERNOON AND EARLY
EVENING. SO OUTSIDE OF PRECIP TRENDS POSSIBLY AFFECTING TEMP
TRENDS SUNDAY...PLACEMENT OF THIS BOUNDARY AND MOVEMENT WILL BE
KEY IN DEFINING MAX TEMPS FOR SUNDAY. DID BRING DOWN TEMPS A TAD
FROM GOING FORECAST BUT HAVE KEPT THE WEST/SOUTHWEST CWA WARMER
THAN THE EAST WITH AREAS STILL TO POSSIBLY REACH THE 80 MARK...AND
AREAS ACROSS THE EASTERN CWA TO REACH THE LOWER 70S WITH 60S
EXPECTED FOR AREAS NEAR THE LAKE. HAVE ADDED SLIGHT CHANCE POPS
FOR THE SOUTHEAST PORTION OF THE CWA FOR SUNDAY AFTERNOON WHERE
BETTER FOCUS AND UPPER LEVEL SUPPORT COULD PROVIDE FOR DEVELOPMENT
OF THUNDERSTORMS.
STRONG UPPER LEVEL RIDGING WILL OCCUR ON MONDAY WITH MID AND UPPER
LEVEL FLOW BECOMING RATHER WEAK. THIS WEAK FLOW COINCIDING WITH A
FORECASTED CLOSED UPPER LEVEL LOW TRACKING THROUGH THE SOUTHERN US
WILL PROVIDE A TRICKY FORECAST THROUGH THE REMAINDER OF THE WEEK
WITH THE ANTICIPATION FOR GUIDANCE TO CONTINUE TO STRUGGLE WITH
PLACEMENT OF LOW LEVEL FEATURES AND INEVITABLE PRECIP.
ALTHOUGH...THERE DOES APPEAR TO BE BETTER CHANCES FOR OBSERVING
CONVECTION MONDAY NIGHT. BETTER FORCING AS WELL AS INSTABILITY
LOOK TO BE IN PLACE FOR THE DEVELOPMENT OF POSSIBLY MORE ORGANIZED
CONVECTION...WITH CURRENT GUIDANCE INDICATING BETTER CHANCES
RESIDING ACROSS NORTHERN ILLINOIS INTO EARLY TUESDAY MORNING. HAVE
NOT GONE OVERLY EXCITED WITH POPS DURING THIS TIME FRAME AS THE
ECMWF REMAINS THE OUTLIER KEEPING A SURFACE LOW AND FORCING/PRECIP
OFF TO THE WEST FOR MOST OF MONDAY AND MONDAY NIGHT. IF THIS WERE
TO COME INTO FRUITION...THAN DRIER CONDITIONS WOULD BE OBSERVED
MONDAY NIGHT WITH PRECIP DELAYED UNTIL TUESDAY.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* COVERAGE/TIMING OF THUNDERSTORMS EARLY THIS MORNING.
* WIND SHIFT TO NORTHEAST BY LATE MORNING/MID-DAY.
* POTENTIAL FOR PERIOD OF MVFR CEILINGS 1500-2000 FT LATE MORNING
TO MID-AFTERNOON.
RATZER
//DISCUSSION...UPDATED 06Z...
INITIAL CONCERN THIS MORNING IS WITH POTENTIAL FOR THUNDERSTORMS
TO AFFECT TERMINALS DURING THE PRE-DAWN HOURS. AREA OF ELEVATED
CONVECTION OVER FAR WESTERN IL AND NORTHEAST IA IS SLOWLY
PROPAGATING TO THE EAST-SOUTHEAST AND WOULD LIKELY SKIRT SOUTH OF
TERMINALS LATER THIS AM. NEW DEVELOPMENT CONTINUES TO OCCUR ON THE
NORTHERN FRINGE OF THE CONVECTIVE COMPLEX ACROSS NORTHEAST IA
HOWEVER...AND SEVERAL HIGH RES EXPLICIT CONVECTION MODELS CONTINUE
TO DEPICT CONTINUED DEVELOPMENT INTO FAR NORTHERN IL TOWARD
09-10Z. THEREFORE HAVE MAINTAINED A BRIEF TEMPO MENTION FOR TS
WITH SOME MINOR TIMING ADJUSTMENTS BASED ON RADAR EXTRAPOLATION
PARTICULARLY FOR KRFD.
ONCE MORNING STORMS MOVE OFF TO THE EAST...NEXT CONCERN IS WINDS
SHIFTING TO THE NORTHEAST AND THE POTENTIAL FOR A PERIOD OF MVFR
CEILINGS. GUIDANCE CONTINUES TO INDICATE WIND SHIFT BY VERY LATE
MORNING/MID-DAY AS WEAK SURFACE WAVE MOVES EAST AND REINFORCING
COLD FRONT SAGS SOUTH ACROSS TERMINALS. FORECAST SOUNDINGS DEPICT
MOIST LAYER 1500-2000 FT IN COOL ADVECTION BENEATH INVERSION
ALOFT. FORECAST SOUNDINGS INDICATE ENOUGH DRYING TAKES PLACE BY
MID-LATE AFTERNOON TO SCATTER CLOUDS.
WINDS...SOUTHEAST LESS THAN 10 KTS AT TAF ISSUANCE EXPECTED TO
BECOME SOUTH OVERNIGHT...THEN LIGHT WESTERLY AFTER SUNRISE.
AFOREMENTIONED FRONT THEN SAGS THROUGH WITH SHIFT TO THE NORTHEAST
BY LATE MORNING OR SO...WITH GUSTS TO 15 KT POSSIBLE IN DEEPER
MIXING WITH LOW LEVEL COLD ADVECTION.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE THUNDERSTORMS WILL AFFECT TRACON AIRSPACE...BUT
MEDIUM CONFIDENCE IN DIRECT IMPACT ON INDIVIDUAL TERMINALS.
* HIGH CONFIDENCE IN WIND TRENDS THROUGH PERIOD.
* MEDIUM CONFIDENCE IN PERIOD OF 1500-2000 FT CIGS LATE MORNING INTO
THIS AFTERNOON.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR WITH CHANCE TSRA MONDAY NIGHT.
TUESDAY...VFR WITH CHANCE SHRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
RATZER
&&
.MARINE...
210 AM CDT
HIGH PRESSURE OVER OHIO EXTENDS NORTHEASTWARD ACROSS THE ST.
LAWRENCE VALLEY THIS MORNING WHILE A COMPLEX SERIES OF WEAK LOW
PRESSURE SYSTEMS ARE NOTED FROM LAKE SUPERIOR INTO THE MID
MISSISSIPPI RIVER VALLEY...WITH BETTER ORGANIZED LOW PRESSURE IN THE
LEE OF THE ROCKIES. ONE LOW...OVER LAKE SUPERIOR...WILL MOVE
SOUTHEASTWARD TODAY AND MOVE OFF THE EAST COAST THIS EVENING WHERE
IT WILL DEEPEN. ANOTHER AREA OF LOW PRESSURE OVER WESTERN IOWA
WILL DRIFT EAST WITH A COOL FRONTAL BOUNDARY SETTING UP FROM THE
FIRST LOW INTO THIS WEAKER LOW. HIGH PRESSURE WILL THEN SPREAD
SOUTHWARD FROM HUDSON BAY AND INTO THE GREAT LAKES BEHIND THE
LOW. AS A RESULT OF THIS FAIRLY COMPLEX PATTERN SOUTHERLY WINDS IN
PLACE ACROSS LAKE MICHIGAN THIS MORNING WILL TURN NORTHEASTERLY
TODAY AND EASTERLY TONIGHT...BEFORE BECOMING SOUTHEAST FOR MONDAY.
IT APPEARS THAT THERE WILL BE SEVERAL PERIODS OF STRONGER WINDS
FROM TONIGHT THROUGH TUESDAY AS THE PRESSURE GRADIENT MODULATES
BETWEEN SYSTEMS. THE FIRST INCREASE SHOULD OCCUR TONIGHT ACROSS
CENTRAL AND SOUTHERN PARTS OF THE LAKE WITH GUSTS TO AROUND 25 KT
EXPECTED. SPEEDS LOOK TO EASE SOMEWHAT MONDAY BEFORE INCREASING
AGAIN MONDAY EVENING THEN DROPPING OFF TUESDAY MORNING AS A LOW
PASSES JUST TO THE SOUTH. THE GRADIENT TIGHTENS BEHIND THE LOW
TUESDAY AFTERNOON AS STRONG HIGH PRESSURE SPREADS INTO THE UPPER
MISSISSIPPI RIVER VALLEY. THIS LOOKS TO BE THE PERIOD OF STRONGEST
WINDS WITH 30 KT POSSIBLE FROM THE NORTH. THE HIGH THEN GRADUALLY
SPREADS EASTWARD KEEPING ITS INFLUENCE OVER THE LAKE THROUGH THE
END OF THE WEEK. LOWS WILL PASS TO THE EAST AND SOUTH OF THE LAKE
SO PERIODS OF SLIGHTLY STRONGER WINDS WILL BE POSSIBLE DESPITE THE
PRESENCE OF THE HIGH...BUT HIGHEST SPEEDS LOOK TO BE UNDER 20 KTS
OR SO FROM MID WEEK ONWARD.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1234 AM CDT SUN APR 1 2012
.DISCUSSION...
908 PM CDT
SOME MINOR CHANGES TO POPS AND WX FOR TONIGHT. MAINLY DELAYING
ARRIVAL OF THREAT OF SHRA AND TSRA UNTIL LATER TONIGHT AND
REDUCING POPS OVER FAR NE IL FOR OVERNIGHT.
RADAR COMPOSITE SHOWS WEAK ECHOES TO THE W THRU N OF THE LOCAL
AREA WHERE INITIAL WAA AND RESULTING UVV AT MAINLY MID LEVELS
OCCURRING. EXPECT THESE ECHOES...ALREADY MOSTLY VIRGA UPSTREAM
WITH FEW IF ANY METARS REPORTING ANY PRECIP...WILL CONTINUE TO
DRY UP AS THEY MOVE INTO INCREASINGLY DRY MID AND LOW LEVELS.
A THUNDERSTORM DEVELOPED JUST NE OF DSM AROUND 0030Z AND ARE
SLOWLY INCREASING IN NUMBER AS THEY MOVE ENE-E. THESE TSRA ARE
WHERE BETTER MOISTURE IN THE 850 TO 800 HPA LAYER IS IN
PLACE...WHERE WEAK SURFACE CONVERGENCE IS OCCURRING...WHERE NOSE
OF 45 KT SOUTHWESTERLY JET AT 5 TO 6 K FT AGL SHOWN BY KDMX VAD
WIND PROFILE IS LOCATED...AND JUST AHEAD OF WEAK MID LEVEL SHORT
WAVE TROF MOVING OVER CENTRAL IA.
CHALLENGE TO FORECAST IS HOW EXTENSIVE FURTHER TSRA DEVELOPMENT
WILL BE AND WHERE AREA OF STORMS IS LIKELY TO MOVE OVERNIGHT.
LATEST RUC13 RUN INDICATES A RATHER SMALL AREA OF MID LEVEL
ISENTROPIC LIFT CURRENTLY OVER CENTRAL IA MOVES THIS AREA
EASTWARD TO E CENTRAL IA 04-06Z...AND THEN SOUTHEASTWARD ACROSS
N CENTRAL IL TO THE CENTRAL IL-IND BORDER BY 12Z. THIS APPEARS TO
BE BEST TRACK FOR THE ELEVATED TSRA THAT IS EXPECTED TO BE
MAINTAINED THROUGH THE OVERNIGHT BY THE LLJ...THE MID LEVEL SHORT
WAVE AND STEEPENING MID LEVEL LAPSE RATES.
EXPECT RATHER SMALL AREA OF TSRA AS MOISTURE WILL BE MARGINAL SO
ONLY ANTICIPATE ACTIVITY WHERE FORCING FACTORS ARE MAXIMIZED
DURING THE OVERNIGHT.
TRS
//PREV DISCUSSION...
317 PM CDT
MAIN FORECAST ISSUES/CONCERNS FOR THE REMAINDER OF THE WEEKEND ARE
WITH CHANCES FOR SHOWERS/THUNDERSTORMS LATE TONIGHT INTO SUNDAY
MORNING...AS WELL AS TEMPERATURE TRENDS SUNDAY.
WITH THE LOW LEVEL CLOUD COVER TODAY MASKING THE FACT THAT HIGH
PRESSURE IS OVERHEAD...RELATIVELY QUIET CONDITIONS HAVE BEEN IN
PLACE FOR ALL OF TODAY. ALTHOUGH...OVER THE LAST COUPLE OF HOURS
SEVERAL HOLES DEVELOPED WITHIN THIS LOW LEVEL MOISTURE. A WARM SUN
AND DRIER AIR ALOFT HAS ALLOWED FOR THESE HOLES TO CONTINUE TO
EXPAND WITH SOME AREAS ACROSS THE SOUTHERN CWA OBSERVING SUNNY TO
PARTLY CLOUDY SKIES. WITHIN THESE AREAS OF BETTER SOLAR
INSOLATION...TEMPS HAVE QUICKLY RISEN INTO THE 50S WITH SOME AREAS
OBSERVING SOME PLEASANT CONDITIONS AS RATHER LIGHT FLOW REMAINS IN
PLACE. EXPECT THIS LOW CLOUD SHIELD TO CONTINUE TO ERODE WITH TIME
LATE THIS AFTERNOON AND EARLY EVENING BUT WITH SOME MID AND HIGH
LEVEL CLOUD COVER TO PUSH OVERHEAD. THIS IN ITSELF SHOULD PROVIDE
PARTLY CLOUDY SKIES FOR TONIGHT...BUT WITH PRECIP CHANCES LATER
TONIGHT TO POSSIBLY BRING MORE CLOUDY CONDITIONS MORE TOWARDS
EARLY SUNDAY MORNING.
LATEST GUIDANCE CONTINUES TO INDICATE SHOWERS AND THUNDERSTORMS
DEVELOPING TONIGHT ACROSS EASTERN IOWA AND SHIFTING EAST/SOUTHEAST
ACROSS A PORTION OF THE CWA THROUGH SUNDAY MORNING. ALL GUIDANCE
IS INDICATING THIS POSSIBILITY BUT WITH SOME VARIABILITY STILL
REMAINING WITH REGARDS TO EXACT TIMING AND PLACEMENT/TRACK. WITH
BACKING 850MB FLOW...A WARMER AND MORE MOIST AIR MASS LOCATED
ACROSS THE CENTRAL PLAINS WILL ADVECT NORTH/NORTHEAST WITH TIME
TONIGHT BRINGING HIGHER DEW POINT AIR TO THE REGION. NORTHWEST FLOW
ALOFT WILL STEER A MID LEVEL IMPULSE AND ATTENDANT SURFACE TROUGH
OUT OF THE NORTHERN PLAINS THIS EVENING...AND HELP TO INITIATE
CONVECTION ALONG A LOW LEVEL BAROCLINIC ZONE DRAPED ACROSS THE
REGION. WITH LOW LEVEL FLOW FEEDING HIGHER THETA E AIR OVER THIS
BOUNDARY AND INTO ANY DEVELOPING PRECIP...THIS AREA OF CONVECTION
COULD SEE SOME EXPANSION IN COVERAGE AS IT SHIFTS EAST/SOUTHEAST
THROUGH THE CWA EARLY SUNDAY MORNING. ALTHOUGH...GUIDANCE
CONTINUES TO STRUGGLE WITH EXACT TIMING OF WHEN CONVECTION WILL
DEVELOP AND WHERE THIS DEVELOPING AREA OF PRECIPITATION WILL
PROGRESS THROUGH. DUE TO THIS UNCERTAINTY STILL IN PLACE...HAVE
NOT MADE MANY CHANGES TO THE GOING POP GRIDS FOR TONIGHT KEEPING
HIGH CHANCE POPS FOR MUCH OF THE CWA AFTER THE MIDNIGHT TIME FRAME
THROUGH MID MORNING SUNDAY. THIS IS BASED ON THE LIKELIHOOD THAT
CONVECTION SHOULD BEGIN TO DEVELOP OVER IOWA ONCE WE DECOUPLE AND
THE LLJ RAMPS UP...WHICH SHOULD BE AROUND THE 3Z-6Z TIME FRAME.
SOME HI RES DATA IS SHOWING THE POSSIBILITY OF AN MCS DEVELOPING
AND QUICKLY SHIFTING THROUGH THE REGION SUNDAY MORNING. HAVE NOT
COMPLETELY THROWN THIS OUT AS A POSSIBILITY...WITH DECENT LOW
LEVEL SHEAR TO BE PRESENT ACROSS THE REGION. A LIMITING FACTOR
WILL BE THE AMOUNT OF INSTABILITY PRESENT OVER NORTHERN ILLINOIS
AND NORTHWEST...WHICH AM CURRENTLY LEANING MORE ON THE SREF MUCAPE
OUTPUT WHICH IS SHOWING WEAKER INSTABILITY PRESENT BY EARLY SUNDAY
MORNING LIMITING MORE ROBUST CONVECTION...WITH OTHER GUIDANCE OF
COURSE ALSO VARYING TO THIS AMOUNT. SO WITH ANY PRECIP WHICH MOVES
THROUGH THE AREA LATE TONIGHT AND EARLY SUNDAY MORNING...A MORE
LIKELY SCENARIO WILL BE FOR THIS TO BE AN UNORGANIZED AREA OF
SHOWERS AND ELEVATED THUNDERSTORMS WITH LITTLE CHANCES FOR SEVERE
WEATHER...HAIL/WIND. ONLY AN ISOLATED THREAT OF HAIL COULD BE
OBSERVED MAINLY FOR THE WESTERN CWA WHERE BETTER INSTABILITY AND
STRONGER EFFECTIVE BULK SHEAR WILL RESIDE. EVEN IF A MORE
ORGANIZED MCS COULD DEVELOP...WOULD EXPECT IT TO FOLLOW THE HIGHER
SURFACE DEW POINT AIR AND BETTER INSTABILITY WHICH WOULD MORE THAN
LIKELY BE SITUATED TO THE SOUTH OF THE CWA. THUS...ONCE AGAIN
KEEPING ANY THREAT FOR SEVERE WEATHER JUST OUTSIDE OF THE CWA.
THIS SITUATION WARRANTS CONTINUED MONITORING...AND WILL MAINTAIN A
MENTION FOR THE CHANCES FOR THUNDERSTORMS TONIGHT IN THE HWO.
ANY LINGERING SHOWERS/THUNDERSTORMS SHOULD EXIT THE CWA BY MID DAY
WITH PARTLY CLOUDY TO SUNNY CONDITIONS EXPECTED THROUGH THE
AFTERNOON. THE EXTENT OF THE MORNINGS PRECIP WILL DEFINITELY PLAY
A KEY ROLE WITH MAX TEMPS ON SUNDAY WITH PERSISTENT WAA ADVECTING
A WARMER AIR MASS OVERHEAD. AS SURFACE WARM FRONT TRIES TO LIFT
NORTHEAST ACROSS THE CWA DURING THE DAY SUNDAY...IT WILL ACTUALLY
BEGIN TO RETREAT AS A COLD FRONT WITH COOLER LOW LEVEL AIR WORKING
ITS WAY BACK WEST ACROSS THE CWA LATE IN THE AFTERNOON AND EARLY
EVENING. SO OUTSIDE OF PRECIP TRENDS POSSIBLY AFFECTING TEMP
TRENDS SUNDAY...PLACEMENT OF THIS BOUNDARY AND MOVEMENT WILL BE
KEY IN DEFINING MAX TEMPS FOR SUNDAY. DID BRING DOWN TEMPS A TAD
FROM GOING FORECAST BUT HAVE KEPT THE WEST/SOUTHWEST CWA WARMER
THAN THE EAST WITH AREAS STILL TO POSSIBLY REACH THE 80 MARK...AND
AREAS ACROSS THE EASTERN CWA TO REACH THE LOWER 70S WITH 60S
EXPECTED FOR AREAS NEAR THE LAKE. HAVE ADDED SLIGHT CHANCE POPS
FOR THE SOUTHEAST PORTION OF THE CWA FOR SUNDAY AFTERNOON WHERE
BETTER FOCUS AND UPPER LEVEL SUPPORT COULD PROVIDE FOR DEVELOPMENT
OF THUNDERSTORMS.
STRONG UPPER LEVEL RIDGING WILL OCCUR ON MONDAY WITH MID AND UPPER
LEVEL FLOW BECOMING RATHER WEAK. THIS WEAK FLOW COINCIDING WITH A
FORECASTED CLOSED UPPER LEVEL LOW TRACKING THROUGH THE SOUTHERN US
WILL PROVIDE A TRICKY FORECAST THROUGH THE REMAINDER OF THE WEEK
WITH THE ANTICIPATION FOR GUIDANCE TO CONTINUE TO STRUGGLE WITH
PLACEMENT OF LOW LEVEL FEATURES AND INEVITABLE PRECIP.
ALTHOUGH...THERE DOES APPEAR TO BE BETTER CHANCES FOR OBSERVING
CONVECTION MONDAY NIGHT. BETTER FORCING AS WELL AS INSTABILITY
LOOK TO BE IN PLACE FOR THE DEVELOPMENT OF POSSIBLY MORE ORGANIZED
CONVECTION...WITH CURRENT GUIDANCE INDICATING BETTER CHANCES
RESIDING ACROSS NORTHERN ILLINOIS INTO EARLY TUESDAY MORNING. HAVE
NOT GONE OVERLY EXCITED WITH POPS DURING THIS TIME FRAME AS THE
ECMWF REMAINS THE OUTLIER KEEPING A SURFACE LOW AND FORCING/PRECIP
OFF TO THE WEST FOR MOST OF MONDAY AND MONDAY NIGHT. IF THIS WERE
TO COME INTO FRUITION...THAN DRIER CONDITIONS WOULD BE OBSERVED
MONDAY NIGHT WITH PRECIP DELAYED UNTIL TUESDAY.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* COVERAGE/TIMING OF THUNDERSTORMS EARLY THIS MORNING.
* WIND SHIFT TO NORTHEAST BY LATE MORNING/MID-DAY.
* POTENTIAL FOR PERIOD OF MVFR CEILINGS 1500-2000 FT LATE MORNING
TO MID-AFTERNOON.
RATZER
//DISCUSSION...UPDATED 06Z...
INITIAL CONCERN THIS MORNING IS WITH POTENTIAL FOR THUNDERSTORMS
TO AFFECT TERMINALS DURING THE PRE-DAWN HOURS. AREA OF ELEVATED
CONVECTION OVER FAR WESTERN IL AND NORTHEAST IA IS SLOWLY
PROPAGATING TO THE EAST-SOUTHEAST AND WOULD LIKELY SKIRT SOUTH OF
TERMINALS LATER THIS AM. NEW DEVELOPMENT CONTINUES TO OCCUR ON THE
NORTHERN FRINGE OF THE CONVECTIVE COMPLEX ACROSS NORTHEAST IA
HOWEVER...AND SEVERAL HIGH RES EXPLICIT CONVECTION MODELS CONTINUE
TO DEPICT CONTINUED DEVELOPMENT INTO FAR NORTHERN IL TOWARD
09-10Z. THEREFORE HAVE MAINTAINED A BRIEF TEMPO MENTION FOR TS
WITH SOME MINOR TIMING ADJUSTMENTS BASED ON RADAR EXTRAPOLATION
PARTICULARLY FOR KRFD.
ONCE MORNING STORMS MOVE OFF TO THE EAST...NEXT CONCERN IS WINDS
SHIFTING TO THE NORTHEAST AND THE POTENTIAL FOR A PERIOD OF MVFR
CEILINGS. GUIDANCE CONTINUES TO INDICATE WIND SHIFT BY VERY LATE
MORNING/MID-DAY AS WEAK SURFACE WAVE MOVES EAST AND REINFORCING
COLD FRONT SAGS SOUTH ACROSS TERMINALS. FORECAST SOUNDINGS DEPICT
MOIST LAYER 1500-2000 FT IN COOL ADVECTION BENEATH INVERSION
ALOFT. FORECAST SOUNDINGS INDICATE ENOUGH DRYING TAKES PLACE BY
MID-LATE AFTERNOON TO SCATTER CLOUDS.
WINDS...SOUTHEAST LESS THAN 10 KTS AT TAF ISSUANCE EXPECTED TO
BECOME SOUTH OVERNIGHT...THEN LIGHT WESTERLY AFTER SUNRISE.
AFOREMENTIONED FRONT THEN SAGS THROUGH WITH SHIFT TO THE NORTHEAST
BY LATE MORNING OR SO...WITH GUSTS TO 15 KT POSSIBLE IN DEEPER
MIXING WITH LOW LEVEL COLD ADVECTION.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE THUNDERSTORMS WILL AFFECT TRACON AIRSPACE...BUT
MEDIUM CONFIDENCE IN DIRECT IMPACT ON INDIVIDUAL TERMINALS.
* HIGH CONFIDENCE IN WIND TRENDS THROUGH PERIOD.
* MEDIUM CONFIDENCE IN PERIOD OF 1500-2000 FT CIGS LATE MORNING INTO
THIS AFTERNOON.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR WITH CHANCE TSRA MONDAY NIGHT.
TUESDAY...VFR WITH CHANCE SHRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
RATZER
&&
.MARINE...
115 PM CDT
WINDS WILL TURN SOUTHERLY AND GRADUALLY INCREASE ACROSS LAKE MI
TONIGHT AS HIGH PRESSURE MOVES EAST FROM THE CENTRAL GREAT LAKES.
LOW PRESSURE WILL EVOLVE EASTWARD ACROSS THE LAKE ON SUNDAY MORNING.
AN ASSOCIATED COLD FRONT WILL SLIP SOUTH AS THIS OCCURS...TURNING
WINDS NORTHERLY ACROSS THE LAKE. THIS FRONT WILL LIKELY MOVE ACROSS
THE NEARSHORE AREAS OF IL AND IN DURING THE EARLY TO MID AFTERNOON
ON SUNDAY. HIGH PRESSURE WILL BRIEFLY PREVAIL ON SUNDAY NIGHT BEFORE
ANOTHER LOW MOVES EAST ACROSS IOWA INTO NORTHERN ILLINOIS. WINDS ARE
EXPECTED TO TURN BACK SOUTHEAST AHEAD OF THIS FEATURE ON MONDAY
AFTERNOON...WITH SOME GUSTS UP TO 25 KT...INCLUDING POSSIBLY IN THE
ILLINOIS NEAR SHORE AREAS. BEHIND THE LOW PASSAGE LATE MONDAY NIGHT
INTO EARLY TUESDAY...THE WINDS WILL ONCE AGAIN SWING BACK NORTHERLY.
HIGH PRESSURE IS THEN FORECAST TO ENCOMPASS MUCH OF THE LAKE
WEDNESDAY THROUGH FRIDAY...THOUGH CONFIDENCE IN THIS IS FAIRLY LOW
DUE TO A CLOSED UPPER LOW IN THE CENTRAL PLAINS WHICH COULD MEANDER
CLOSE ENOUGH TO CAUSE SLIGHTLY STRONGER WINDS. OVERALL AT THIS
TIME...NO LONG-LIVED GUSTY OR HIGH WAVE PERIODS ARE EXPECTED IN
THE NEXT WEEK.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
401 AM EDT SUN APR 1 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...A WEAK FRONTAL SYSTEM MOVING THROUGH COULD BRING
CHANCES FOR THUNDERSTORMS ACROSS THE AREA LATE TONIGHT INTO SUNDAY.
BY SUNDAY NIGHT UPPER RIDGING SHOULD REBUILD AND DRY THE WEATHER
OUT THROUGH MONDAY...BUT BY MONDAY NIGHT ANOTHER FRONTAL SYSTEM
WILL APPROACH AND STALL OUT AND BRING THUNDERSTORM CHANCES FOR
MONDAY NIGHT THROUGH THURSDAY. MORE UPPER RIDGING WILL DRY THINGS
OUT FOR THE WEEKEND.
&&
.NEAR TERM /OVERNIGHT/...
LARGE AREA OF LOW STRATUS HAS FINALLY SHIFTED EAST WITH ONLY FAR
NORTHEASTERN COUNTIES STILL UNDERNEATH THE DECK. REMAINDER OF THE
FORECAST AREA HAD BECOME PARTLY CLOUDY WITH MID AND HIGH LEVEL
CLOUDS DRIFTING ACROSS THE REGION. QUITE A RANGE OF TEMPERATURES
EXISTED ACROSS THE FORECAST AREA AS OF 00Z...FROM MID 40S OVER THE
NORTHEAST WHERE SKIES HAD BEEN CLOUDY ALL DAY TO MID 60S IN THE
LOWER WABASH VALLEY.
FOCUS FOR THE OVERNIGHT IS POTENTIAL FOR CONVECTION TO IMPACT
WESTERN COUNTIES PRIOR TO DAYBREAK. SHORT RANGE MODEL GUIDANCE
CONTINUING TO ADVERTISE DEVELOPMENT OF SCATTERED CONVECTION OVER
EASTERN IOWA/WESTERN ILLINOIS SHORTLY AFTER MIDNIGHT AS AN UPPER
LEVEL DISTURBANCE MOVES INTO THE REGION. PRESENCE OF A 35KT LOW
LEVEL JET AND AXIS OF ELEVATED INSTABILITY SHOULD FURTHER
CONTRIBUTE TO CONVECTIVE DEVELOPMENT IN THESE AREAS. STEERING FLOW
ALOFT WOULD SUGGEST THAT CONVECTION WILL MOVE SOUTHEAST AND
POTENTIALLY MIGRATE INTO THE NORTHERN WABASH VALLEY LATE TONIGHT.
HAVE CHOSEN TO EXPAND LOW CHANCE POPS TO ENCOMPASS PORTIONS OF THE
FORECAST AREA WEST OF A KOKOMO TO INDY METRO TO TERRE HAUTE LINE
BETWEEN 09-12Z. HRRR GUIDANCE SUGGESTIVE OF LEADING EDGE OF
CONVECTION ARRIVING INTO THESE AREAS SHORTLY BEFORE DAYBREAK.
WHILE STORMS SHOULD BE WEAKENING BY THE TIME THEY ARRIVE IN
CENTRAL INDIANA AS THE ENVIRONMENT WILL BE LESS FAVORABLE...
POTENTIAL FOR STRONGER CELLS TO PRODUCE SMALL HAIL. WILL CONTINUE
TO HIGHLIGHT IN THE HWO.
LOWERED TEMPS A DEGREE OR TWO OVERNIGHT BASED ON CURRENT OBS...AND
ADJUSTED TIMING AS LOWS LIKELY TO BOTTOM OUT BETWEEN 06 AND 08Z
BEFORE ANY STORMS ARRIVE.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
MODELS ARE IN DECENT AGREEMENT ON THE SHORT TERM SO WILL USE A
CONSENSUS GENERALLY...BUT THOUGHT EARLY ON THE NAM WAS A LITTLE
OVERZEALOUS IN POPS AND PRECIP ARRIVAL WITH THE SUNDAY SYSTEM SO
THERE WILL LEAN TOWARD THE GFS/ECMWF/SREFS. COULD HAVE AN MCS
ARRIVING IN THE NORTHWEST TO START OUT SUNDAY. VERY WEAK UPPER
FORCING WITH A LITTLE SHORTWAVE MOVING THROUGH BUT ISENTROPIC LIFT
SHOULD BE GOING THROUGH THE DAY ON SUNDAY. INSTABILITY WILL INCREASE
THROUGH THE DAY SO THAT MIXED LAYER CAPES OF 1000 TO 1500 OR SO WILL
BE IN PLACE ACROSS THE EAST BY THE AFTERNOON. MARGINAL SHEAR /BOTH
DIRECTIONAL AND SPEED/ WILL BE AVAILABLE AS WELL DURING THE
AFTERNOON...AND THUS THE INCLUSION OF A SLIGHT RISK FOR SEVERE
WEATHER ACROSS MUCH OF THE EASTERN COUNTIES FOR THAT TIME. ALSO HAVE
MID LEVEL LAPSE RATES AROUND 7-8C SO EXPECT THE MAIN THREAT TO BE
LARGE HAIL.
LEFT A SLIGHT CHANCE IN THE FAR EAST THROUGH 3Z AS SYSTEM IS MOVING
OUT OF THE AREA. UPPER RIDGING BUILDS BACK IN AND KEPT POPS OUT
THROUGH MONDAY. BY MONDAY NIGHT ANOTHER FRONTAL SYSTEM MOVES IN TO
NORTHERN ILLINOIS AND POSSIBLY NORTHERN INDIANA. THIS SURFACE LOW
AND ISENTROPIC LIFT WILL SERVE AS THE MAIN FORCING MECHANISMS
WITHOUT MUCH IN THE WAY OF UPPER FORCING AVAILABLE. WILL HAVE A
CHANCE FOR THUNDERSTORMS MONDAY NIGHT AND INTO TUESDAY WITH
THIS...WITH HIGHER CHANCES ON TUESDAY WITH THE LOW PASSING OVER THE
AREA.
FOR HIGH TEMPERATURES GENERALLY STUCK TOWARD THE WARMER END OF THE
GUIDANCE ENVELOPE BASED ON RECENT VERIFICATION...AND COULD SEE A
DECENT GRADIENT ACROSS THE AREA ON TUESDAY. FOR LOWS WENT A BIT
WARMER THAN A CONSENSUS BASED ON EXPECTED CLOUD COVER AND FOR MONDAY
NIGHT STUCK NEAR THE WET BULB TEMPERATURES WITH POTENTIAL FOR RAIN.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
EUROPEAN MODEL BECOMES MUCH COLDER THAN GFS AT 850 MILLIBARS LATE
IN PERIOD. OVERALL EUROPEAN MORE CONSISTENT WITH CANADIAN AND
BRITISH MODELS IN DEVELOPING A VORTEX OVER THE NORTHEAST STATES THAT
WILL DRAW RELATIVELY CHILLY AIR INTO INDIANA.
FORTUNATELY...ALL BLEND MODEL SEEMS TO CAPTURE THIS
FAIRLY WELL WITH HIGHS LOWER 60S AND LOWS LOWER 40S LATE IN THE
PERIOD. DID NOT SEE NEED TO CHANGE ALL BLEND INITIALIZATION.
ALTHOUGH EUROPEAN AND GFS MUCH DIFFERENT IN STRENGTH...THEIR PHASE
IS NOT THAT DIFFERENT. WHILE THIS RESULTS IN BIG DIFFERENCES FOR
TEMPERATURES...TIMING OF PRECIPITATION APT TO BE CLOSER. ALL BLEND
SEEMS TO CAPTURE THIS WITH QUITE LOW POPS FRIDAY AND SATURDAY IN
PARTICULAR. NO NEED TO CHANGE INITIALIZATION MUCH.
&&
.AVIATION /DISCUSSION FOR THE 010900Z TAF UPDATE/...
EARLIER FORECAST ON TRACK OVERALL...BUT TUNING WILL BE NEEDED FOR
PRECISE TIMING AS SHOWERS AND THUNDERSTORMS MOVE IN FROM THE WEST
AND NORTH. CONFIDENCE IS LOW SINCE EXACT CONDITIONS AT ANY ONE
TERMINAL COULD CHANGE GREATLY OVER SHORT PERIODS.
MVFR CONDITIONS IN TSRA POSSIBLE THROUGH 15Z...THEN EXPECT A
RETURN TO VFR FOR THE REMAINDER OF SUNDAY.
AREA OF TSRA ACROSS NORTHWEST ILLINOIS WILL CONTINUE TO SHIFT
SOUTHEAST TOWARD THE SITES. QUESTIONS ARISE IN HOW WELL THEY WILL
HOLD TOGETHER AS UPPER SUPPORT WILL FIGHT WITH POOR INSTABILITY IN
THE LOWER LEVELS. FOR NOW WILL JUST GO WITH VCSH AND CB
MENTION...BUT WILL HAVE TO KEEP A CLOSE EYE ON TSRA EVOLUTION.
TEMPO GROUPS MAY BE NEEDED FOR SHORT TIME IN TAFS.
TSRA THREAT SHOULD DIMINISH BY 15Z. UNCERTAINTY REMAINS ON ANY
LINGERING CLOUD COVER FROM TSRA...BUT EXPECT BKN CU TO DEVELOP IF
THERE IS SUNSHINE. THUS JUST KEPT BKN060 DURING THE DAY SUNDAY.
ADDITIONAL CONVECTION MAY DEVELOP SUNDAY AFTERNOON...BUT THAT IS
TOO FAR OUT TO MENTION IN TAFS AT THE MOMENT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...RYAN
SHORT TERM...CP
LONG TERM....JK
AVIATION...JK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
317 AM EDT SUN APR 1 2012
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...A WEAK FRONTAL SYSTEM MOVING THROUGH COULD BRING
CHANCES FOR THUNDERSTORMS ACROSS THE AREA LATE TONIGHT INTO SUNDAY.
BY SUNDAY NIGHT UPPER RIDGING SHOULD REBUILD AND DRY THE WEATHER
OUT THROUGH MONDAY...BUT BY MONDAY NIGHT ANOTHER FRONTAL SYSTEM
WILL APPROACH AND STALL OUT AND BRING THUNDERSTORM CHANCES FOR
MONDAY NIGHT THROUGH THURSDAY. MORE UPPER RIDGING WILL DRY THINGS
OUT FOR THE WEEKEND.
&&
.NEAR TERM /OVERNIGHT/...
LARGE AREA OF LOW STRATUS HAS FINALLY SHIFTED EAST WITH ONLY FAR
NORTHEASTERN COUNTIES STILL UNDERNEATH THE DECK. REMAINDER OF THE
FORECAST AREA HAD BECOME PARTLY CLOUDY WITH MID AND HIGH LEVEL
CLOUDS DRIFTING ACROSS THE REGION. QUITE A RANGE OF TEMPERATURES
EXISTED ACROSS THE FORECAST AREA AS OF 00Z...FROM MID 40S OVER THE
NORTHEAST WHERE SKIES HAD BEEN CLOUDY ALL DAY TO MID 60S IN THE
LOWER WABASH VALLEY.
FOCUS FOR THE OVERNIGHT IS POTENTIAL FOR CONVECTION TO IMPACT
WESTERN COUNTIES PRIOR TO DAYBREAK. SHORT RANGE MODEL GUIDANCE
CONTINUING TO ADVERTISE DEVELOPMENT OF SCATTERED CONVECTION OVER
EASTERN IOWA/WESTERN ILLINOIS SHORTLY AFTER MIDNIGHT AS AN UPPER
LEVEL DISTURBANCE MOVES INTO THE REGION. PRESENCE OF A 35KT LOW
LEVEL JET AND AXIS OF ELEVATED INSTABILITY SHOULD FURTHER
CONTRIBUTE TO CONVECTIVE DEVELOPMENT IN THESE AREAS. STEERING FLOW
ALOFT WOULD SUGGEST THAT CONVECTION WILL MOVE SOUTHEAST AND
POTENTIALLY MIGRATE INTO THE NORTHERN WABASH VALLEY LATE TONIGHT.
HAVE CHOSEN TO EXPAND LOW CHANCE POPS TO ENCOMPASS PORTIONS OF THE
FORECAST AREA WEST OF A KOKOMO TO INDY METRO TO TERRE HAUTE LINE
BETWEEN 09-12Z. HRRR GUIDANCE SUGGESTIVE OF LEADING EDGE OF
CONVECTION ARRIVING INTO THESE AREAS SHORTLY BEFORE DAYBREAK.
WHILE STORMS SHOULD BE WEAKENING BY THE TIME THEY ARRIVE IN
CENTRAL INDIANA AS THE ENVIRONMENT WILL BE LESS FAVORABLE...
POTENTIAL FOR STRONGER CELLS TO PRODUCE SMALL HAIL. WILL CONTINUE
TO HIGHLIGHT IN THE HWO.
LOWERED TEMPS A DEGREE OR TWO OVERNIGHT BASED ON CURRENT OBS...AND
ADJUSTED TIMING AS LOWS LIKELY TO BOTTOM OUT BETWEEN 06 AND 08Z
BEFORE ANY STORMS ARRIVE.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
MODELS ARE IN DECENT AGREEMENT ON THE SHORT TERM SO WILL USE A
CONSENSUS GENERALLY...BUT THOUGHT EARLY ON THE NAM WAS A LITTLE
OVERZEALOUS IN POPS AND PRECIP ARRIVAL WITH THE SUNDAY SYSTEM SO
THERE WILL LEAN TOWARD THE GFS/ECMWF/SREFS. COULD HAVE AN MCS
ARRIVING IN THE NORTHWEST TO START OUT SUNDAY. VERY WEAK UPPER
FORCING WITH A LITTLE SHORTWAVE MOVING THROUGH BUT ISENTROPIC LIFT
SHOULD BE GOING THROUGH THE DAY ON SUNDAY. INSTABILITY WILL INCREASE
THROUGH THE DAY SO THAT MIXED LAYER CAPES OF 1000 TO 1500 OR SO WILL
BE IN PLACE ACROSS THE EAST BY THE AFTERNOON. MARGINAL SHEAR /BOTH
DIRECTIONAL AND SPEED/ WILL BE AVAILABLE AS WELL DURING THE
AFTERNOON...AND THUS THE INCLUSION OF A SLIGHT RISK FOR SEVERE
WEATHER ACROSS MUCH OF THE EASTERN COUNTIES FOR THAT TIME. ALSO HAVE
MID LEVEL LAPSE RATES AROUND 7-8C SO EXPECT THE MAIN THREAT TO BE
LARGE HAIL.
LEFT A SLIGHT CHANCE IN THE FAR EAST THROUGH 3Z AS SYSTEM IS MOVING
OUT OF THE AREA. UPPER RIDGING BUILDS BACK IN AND KEPT POPS OUT
THROUGH MONDAY. BY MONDAY NIGHT ANOTHER FRONTAL SYSTEM MOVES IN TO
NORTHERN ILLINOIS AND POSSIBLY NORTHERN INDIANA. THIS SURFACE LOW
AND ISENTROPIC LIFT WILL SERVE AS THE MAIN FORCING MECHANISMS
WITHOUT MUCH IN THE WAY OF UPPER FORCING AVAILABLE. WILL HAVE A
CHANCE FOR THUNDERSTORMS MONDAY NIGHT AND INTO TUESDAY WITH
THIS...WITH HIGHER CHANCES ON TUESDAY WITH THE LOW PASSING OVER THE
AREA.
FOR HIGH TEMPERATURES GENERALLY STUCK TOWARD THE WARMER END OF THE
GUIDANCE ENVELOPE BASED ON RECENT VERIFICATION...AND COULD SEE A
DECENT GRADIENT ACROSS THE AREA ON TUESDAY. FOR LOWS WENT A BIT
WARMER THAN A CONSENSUS BASED ON EXPECTED CLOUD COVER AND FOR MONDAY
NIGHT STUCK NEAR THE WET BULB TEMPERATURES WITH POTENTIAL FOR RAIN.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
EUROPEAN MODEL BECOMES MUCH COLDER THAN GFS AT 850 MILLIBARS LATE
IN PERIOD. OVERALL EUROPEAN MORE CONSISTENT WITH CANADIAN AND
BRITISH MODELS IN DEVELOPING A VORTEX OVER THE NORTHEAST STATES THAT
WILL DRAW RELATIVELY CHILLY AIR INTO INDIANA.
FORTUNATELY...ALL BLEND MODEL SEEMS TO CAPTURE THIS
FAIRLY WELL WITH HIGHS LOWER 60S AND LOWS LOWER 40S LATE IN THE
PERIOD. DID NOT SEE NEED TO CHANGE ALL BLEND INITIALIZATION.
ALTHOUGH EUROPEAN AND GFS MUCH DIFFERENT IN STRENGTH...THEIR PHASE
IS NOT THAT DIFFERENT. WHILE THIS RESULTS IN BIG DIFFERENCES FOR
TEMPERATURES...TIMING OF PRECIPITATION APT TO BE CLOSER. ALL BLEND
SEEMS TO CAPTURE THIS WITH QUITE LOW POPS FRIDAY AND SATURDAY IN
PARTICULAR. NO NEED TO CHANGE INITIALIZATION MUCH.
&&
.AVIATION /DISCUSSION FOR THE 010600Z TAFS/...
MVFR CONDITIONS IN FOG OR TSRA POSSIBLE THROUGH 15Z...THEN EXPECT A
RETURN TO VFR FOR THE REMAINDER OF THE DAY ON SUNDAY.
AREA OF TSRA ACROSS NORTHWEST ILLINOIS WILL CONTINUE TO SHIFT
SOUTHEAST TOWARD THE SITES. QUESTIONS ARISE IN HOW WELL THEY WILL
HOLD TOGETHER AS UPPER SUPPORT WILL FIGHT WITH POOR INSTABILITY IN
THE LOWER LEVELS. FOR NOW WILL JUST GO WITH VCSH AND CB
MENTION...BUT WILL HAVE TO KEEP A CLOSE EYE ON TSRA EVOLUTION. AT
THE MOMENT CONFIDENCE IS LOW.
TSRA/FOG THREAT SHOULD DIMINISH BY 15Z. UNCERTAINTY REMAINS ON ANY
LINGERING CLOUD COVER FROM TSRA...BUT EXPECT BKN CU TO DEVELOP IF
THERE IS SUNSHINE. THUS JUST KEPT BKN060 DURING THE DAY SUNDAY.
ADDITIONAL CONVECTION MAY DEVELOP SUNDAY AFTERNOON...BUT THAT IS TOO
FAR OUT TO MENTION IN TAFS AT THE MOMENT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...RYAN
SHORT TERM...CP
LONG TERM....JK
AVIATION...50/JK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1245 AM EDT SUN APR 1 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...A WEAK FRONTAL SYSTEM MOVING THROUGH COULD BRING
CHANCES FOR THUNDERSTORMS ACROSS THE AREA LATE TONIGHT INTO SUNDAY.
BY SUNDAY NIGHT UPPER RIDGING SHOULD REBUILD AND DRY THE WEATHER
OUT THROUGH MONDAY...BUT BY MONDAY NIGHT ANOTHER FRONTAL SYSTEM
WILL APPROACH AND STALL OUT AND BRING THUNDERSTORM CHANCES FOR
MONDAY NIGHT THROUGH THURSDAY. MORE UPPER RIDGING WILL DRY THINGS
OUT FOR THE WEEKEND.
&&
.NEAR TERM /OVERNIGHT/...
LARGE AREA OF LOW STRATUS HAS FINALLY SHIFTED EAST WITH ONLY FAR
NORTHEASTERN COUNTIES STILL UNDERNEATH THE DECK. REMAINDER OF THE
FORECAST AREA HAD BECOME PARTLY CLOUDY WITH MID AND HIGH LEVEL
CLOUDS DRIFTING ACROSS THE REGION. QUITE A RANGE OF TEMPERATURES
EXISTED ACROSS THE FORECAST AREA AS OF 00Z...FROM MID 40S OVER THE
NORTHEAST WHERE SKIES HAD BEEN CLOUDY ALL DAY TO MID 60S IN THE
LOWER WABASH VALLEY.
FOCUS FOR THE OVERNIGHT IS POTENTIAL FOR CONVECTION TO IMPACT
WESTERN COUNTIES PRIOR TO DAYBREAK. SHORT RANGE MODEL GUIDANCE
CONTINUING TO ADVERTISE DEVELOPMENT OF SCATTERED CONVECTION OVER
EASTERN IOWA/WESTERN ILLINOIS SHORTLY AFTER MIDNIGHT AS AN UPPER
LEVEL DISTURBANCE MOVES INTO THE REGION. PRESENCE OF A 35KT LOW
LEVEL JET AND AXIS OF ELEVATED INSTABILITY SHOULD FURTHER
CONTRIBUTE TO CONVECTIVE DEVELOPMENT IN THESE AREAS. STEERING FLOW
ALOFT WOULD SUGGEST THAT CONVECTION WILL MOVE SOUTHEAST AND
POTENTIALLY MIGRATE INTO THE NORTHERN WABASH VALLEY LATE TONIGHT.
HAVE CHOSEN TO EXPAND LOW CHANCE POPS TO ENCOMPASS PORTIONS OF THE
FORECAST AREA WEST OF A KOKOMO TO INDY METRO TO TERRE HAUTE LINE
BETWEEN 09-12Z. HRRR GUIDANCE SUGGESTIVE OF LEADING EDGE OF
CONVECTION ARRIVING INTO THESE AREAS SHORTLY BEFORE DAYBREAK.
WHILE STORMS SHOULD BE WEAKENING BY THE TIME THEY ARRIVE IN
CENTRAL INDIANA AS THE ENVIRONMENT WILL BE LESS FAVORABLE...
POTENTIAL FOR STRONGER CELLS TO PRODUCE SMALL HAIL. WILL CONTINUE
TO HIGHLIGHT IN THE HWO.
LOWERED TEMPS A DEGREE OR TWO OVERNIGHT BASED ON CURRENT OBS...AND
ADJUSTED TIMING AS LOWS LIKELY TO BOTTOM OUT BETWEEN 06 AND 08Z
BEFORE ANY STORMS ARRIVE.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
MODELS ARE IN DECENT AGREEMENT ON THE SHORT TERM SO WILL USE A
CONSENSUS GENERALLY...BUT THOUGHT EARLY ON THE NAM WAS A LITTLE
OVERZEALOUS IN POPS AND PRECIP ARRIVAL WITH THE SUNDAY SYSTEM SO
THERE WILL LEAN TOWARD THE GFS/ECMWF/SREFS. COULD HAVE AN MCS
ARRIVING IN THE NORTHWEST TO START OUT SUNDAY. VERY WEAK UPPER
FORCING WITH A LITTLE SHORTWAVE MOVING THROUGH BUT ISENTROPIC LIFT
SHOULD BE GOING THROUGH THE DAY ON SUNDAY. INSTABILITY WILL INCREASE
THROUGH THE DAY SO THAT MIXED LAYER CAPES OF 1000 TO 1500 OR SO WILL
BE IN PLACE ACROSS THE EAST BY THE AFTERNOON. MARGINAL SHEAR /BOTH
DIRECTIONAL AND SPEED/ WILL BE AVAILABLE AS WELL DURING THE
AFTERNOON...AND THUS THE INCLUSION OF A SLIGHT RISK FOR SEVERE
WEATHER ACROSS MUCH OF THE EASTERN COUNTIES FOR THAT TIME. ALSO HAVE
MID LEVEL LAPSE RATES AROUND 7-8C SO EXPECT THE MAIN THREAT TO BE
LARGE HAIL.
LEFT A SLIGHT CHANCE IN THE FAR EAST THROUGH 3Z AS SYSTEM IS MOVING
OUT OF THE AREA. UPPER RIDGING BUILDS BACK IN AND KEPT POPS OUT
THROUGH MONDAY. BY MONDAY NIGHT ANOTHER FRONTAL SYSTEM MOVES IN TO
NORTHERN ILLINOIS AND POSSIBLY NORTHERN INDIANA. THIS SURFACE LOW
AND ISENTROPIC LIFT WILL SERVE AS THE MAIN FORCING MECHANISMS
WITHOUT MUCH IN THE WAY OF UPPER FORCING AVAILABLE. WILL HAVE A
CHANCE FOR THUNDERSTORMS MONDAY NIGHT AND INTO TUESDAY WITH
THIS...WITH HIGHER CHANCES ON TUESDAY WITH THE LOW PASSING OVER THE
AREA.
FOR HIGH TEMPERATURES GENERALLY STUCK TOWARD THE WARMER END OF THE
GUIDANCE ENVELOPE BASED ON RECENT VERIFICATION...AND COULD SEE A
DECENT GRADIENT ACROSS THE AREA ON TUESDAY. FOR LOWS WENT A BIT
WARMER THAN A CONSENSUS BASED ON EXPECTED CLOUD COVER AND FOR MONDAY
NIGHT STUCK NEAR THE WET BULB TEMPERATURES WITH POTENTIAL FOR RAIN.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ENSEMBLES IN GENERAL AGREEMENT IN BRINGING A SYSTEM THAT IS PROGGED
TO BE MOVING INTO THE WEST COAST SUNDAY ACROSS THE LOCAL AREA AROUND
THE MIDDLE OF NEXT WEEK. ENSEMBLE TREND HAS BEEN TOWARDS CUTTING
THIS SYSTEM OFF FROM THE MAIN WESTERLIES...AND TODAY THE MAJORITY OF
THE ENSEMBLES POINT IN THIS DIRECTION...WITH THE EFFECTS OF THE
CUTOFF AFFECTING THE AREA INTO THURSDAY. WILL GO WITH CHANCE POPS ON
WEDNESDAY AND THURSDAY OVER MAINLY THE SOUTHERN ZONES...WHICH WILL
BE CLOSER TO CUTOFF LOW. WILL CONTINUE WITH A DRY FORECAST FRIDAY
AND SATURDAY AT THIS TIME WITH UPPER RIDGING MOVING THROUGH...
ALTHOUGH SOME ENSEMBLES BRING A PRECIPITATION THREAT BACK INTO THE
AREA BY NEXT SATURDAY. MAY NEED TO ADD POPS TO NEXT WEEKEND AT A
LATER TIME IF FUTURE TRENDS POINT IN THAT DIRECTION.
&&
.AVIATION /DISCUSSION FOR THE 010600Z TAFS/...
MVFR CONDITIONS IN FOG OR TSRA POSSIBLE THROUGH 15Z...THEN EXPECT A
RETURN TO VFR FOR THE REMAINDER OF THE DAY ON SUNDAY.
AREA OF TSRA ACROSS NORTHWEST ILLINOIS WILL CONTINUE TO SHIFT
SOUTHEAST TOWARD THE SITES. QUESTIONS ARISE IN HOW WELL THEY WILL
HOLD TOGETHER AS UPPER SUPPORT WILL FIGHT WITH POOR INSTABILITY IN
THE LOWER LEVELS. FOR NOW WILL JUST GO WITH VCSH AND CB
MENTION...BUT WILL HAVE TO KEEP A CLOSE EYE ON TSRA EVOLUTION. AT
THE MOMENT CONFIDENCE IS LOW.
TSRA/FOG THREAT SHOULD DIMINISH BY 15Z. UNCERTAINTY REMAINS ON ANY
LINGERING CLOUD COVER FROM TSRA...BUT EXPECT BKN CU TO DEVELOP IF
THERE IS SUNSHINE. THUS JUST KEPT BKN060 DURING THE DAY SUNDAY.
ADDITIONAL CONVECTION MAY DEVELOP SUNDAY AFTERNOON...BUT THAT IS TOO
FAR OUT TO MENTION IN TAFS AT THE MOMENT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...RYAN
SHORT TERM...CP
LONG TERM....JAS
AVIATION...50/JK
AREA FORECAST DISCUSSION
NWS WICHITA KS
337 AM CDT SUN APR 1 2012
.DISCUSSION...
TODAY-TONIGHT:
UNSEASONABLY WARM TEMPERTURES ARE EXPECTED WITH FORECAST MAXES
GETTING CLOSE TO RECORDS AT SEVERAL LOCATIONS. ANTICIPATE LOW
CLOUDS WILL THIN/ERODE BY MIDDAY WITH TEMPERATURES BASED ON WARMER
MODEL OUTPUT STATISTICS/BIASES FROM YESTERDAY. FAIR AMOUNT OF
SPREAD IN SHORT TERM MODELS/MODEL OUTPUT STATISTICS WITH WIND SPEEDS
DURING THE DAY...WITH SOME MODEL OUTPUT STATISTICS APPROACHING
ADVISORY CRITERIA AT 2100 UTC. LOW CLOUDS MAY DEVELOP AGAIN
TONIGHT IN SOUTHEAST KS
MON-MON NIGHT:
GOING TREND OF POPS MON AFTERNOON ALONG SAGGING FRONT STILL LOOKS
ON TARGET. STILL FAIR AMOUNT OF WIGGLE ROOM WHERE BOUNDARY WILL BE
WHEN INITIATION OCCURS...AND SHADED POPS BASED ON MODEL CONSENSUS.
WHILE BOTH GFS/NAM SHOW GOOD INSTABILITY...DEEP LAYER SHEAR AND
HODOGRAPHS ARE NOT FAVORABLE FOR SEVERE. HOWEVER GIVEN PROXIMITY
TO UPPER LOW AND EFFECT OF EVEN SMALL CHANGES TO ITS TRACK...WILL
CONTINUE MENTION OF STRONG STORMS IN HAZARDOUS WEATHER OUTLOOK FOR
MON AFTERNOON-EVENING. VERY MILD TEMPERATURES ANTICIPATED MON
NIGHT WITH WINDS STAYING UP A BIT AND INFLUX OF LOW LEVEL MOISTURE.
TUE-WED:
LATEST RUNS LESS LIKELY TO SUPPORT SIGNIFICANT DRY SLOT WHICH
COULD SIGNIFICANTLY IMPACT POPS/TEMPERATURES. PRECIPITATION
CHANCES SHOULD BE HIGHEST ON W-NW-NE SIDE OF UPPER LOW...AND
SHADED HIGHEST POPS ACROSS CENTRAL KS. TEMPERATURES SOMEWHAT
TRICKY WITH COMBO OF COLD AIR ADVECTION/CLOUDS AND PRECIPITATION.
THU-SAT:
ALTHOUGH TEMPERATURES WILL BE COOLER THIS PERIOD...VALUES WILL
STILL BE ABOVE NORMAL. LATEST MODELS STILL HINTING AT SOME
PRECIPITATION POTENTIAL ON FRI NIGHT/SAT WITH FRONT MOVING THROUGH
THE AREA...ALTHOUGH THERE IS SOME QUESTION AS TO THE AMOUNT/DEPTH
OF MOISTURE. -HOWERTON
&&
.FIRE WEATHER... DESPITE UNSEASONBALY WARM TEMPERATURES AND
INCREASING WINDS ON TODAY...THE GRASSLAND FIRE DANGER RISK IS
EXPECTED TO BE ONLY SLIGHTLY ELEVATED DUE TO THE EARLY SPRING
GREEN-UP.-HOWERTON
&&
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MAIN CONCERN REMAINS POTENTIAL FOR LOW STRATUS.
LEE TROUGH WILL ALLOW LIGHT SOUTH-SOUTHEASTERLY WINDS TO CONTINUE
OVERNIGHT WITH INCREASING BOUNDARY LAYER MOISTURE. THIS SHOULD
RESULT IN LIFR-IFR STRATUS DEVELOPMENT OVER MUCH OF THE AREA DURING
THE EARLY AM HOURS SUNDAY. THIS IS SUPPORTED IN THE NAM...GFS...RUC...AND
3KM HRRR MODELS. FORECAST CONFIDENCE IS ABOVE AVERAGE GIVEN THE
LOW STRATUS OCCURRENCE IN CENTRAL/SOUTHWEST OK AND NORTH CENTRAL
TEXAS SATURDAY MORNING. THE STRATUS LOOKS TO BURN OFF TOWARD MIDDAY
SUNDAY. BETTER MIXING AND NEAR FULL SUNSHINE SUNDAY AFTERNOON
SHOULD RESULT IN SOUTHERLY GUSTS ~25 KT MOST OF THE AREA.
JMC
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 85 63 80 54 / 0 0 20 60
HUTCHINSON 86 60 78 51 / 0 0 20 50
NEWTON 84 63 79 53 / 0 0 20 50
ELDORADO 84 66 82 55 / 0 0 20 50
WINFIELD-KWLD 86 65 85 57 / 0 0 20 60
RUSSELL 88 56 70 45 / 0 0 10 30
GREAT BEND 87 55 72 44 / 0 0 20 40
SALINA 87 61 76 50 / 0 0 20 40
MCPHERSON 86 61 77 50 / 0 0 20 50
COFFEYVILLE 87 68 88 62 / 0 10 10 40
CHANUTE 86 65 88 60 / 0 10 10 40
IOLA 86 65 88 59 / 0 10 10 30
PARSONS-KPPF 87 67 88 60 / 0 10 10 40
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...CORRECTED
NWS DODGE CITY KS
334 AM CDT SUN APR 1 2012
...UPDATED SYNOPSIS/SHORT TERM/FIRE WEATHER/CLIMATE DISCUSSIONS...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 333 AM CDT SUN APR 1 2012
.SYNOPSIS...
ISSUED AT 333 AM CDT SUN APR 1 2012
THE APRIL 1 2012 00Z 300 HPA SYNOPTIC MAP SHOWED A LARGE ANTICYCLONIC
CURVED JET EXTENDING ACROSS THE WESTERN UNITED STATES AND INTO THE CANADIAN
PRAIRIE PROVINCES. A JET STREAK OF AROUND 130-140 KT WAS OBSERVED FROM
KREV TO KBOI. AT 500 HPA, AN AMPLIFIED TROUGH ASSOCIATED WITH THE JET
STREAK WAS LOCATED ACROSS THE PACIFIC NORTHWEST AND INTO NORTHERN CALIFORNIA.
CONSIDERABLE COLD AIR ADVECTION WITH 500 HPA DELTA TEMPERATURES AROUND
10 DEG C WAS OBSERVED ACROSS THE PACIFIC NORTHWEST ALONG WITH SIGNIFICANT
HEIGHT FALLS. MORE LOCALLY AND AT LOWER LEVELS, A WARM AND DRY PLUME
AT 700 AND 850 HPA PREVAILED ACROSS THE HIGH PLAINS. AT THE SFC, A LOW
PRESSURE CENTER WAS LOCATED ACROSS EASTERN COLORADO. A DRYLINE ASSOCIATED
WITH THIS FEATURE WAS LOCATED ACROSS THE SOUTHERN HIGH PLAINS AS WELL.
THIS MORNING:
AS WITH LAST NIGHT, HAVE FOLLOWED HRRR GUIDANCE IN CONCERNING THE POTENTIAL
FOR PATCHY FOG FORMATION THIS MORNING. THIS MODEL HAS BEEN TRENDING
WELL AS SITES AROUND KANSAS AND OKLAHOMA HAVE BEEN REPORTING BR THROUGH
THE OVERNIGHT HOURS. I DID, HOWEVER, TAKE A MORE CONSERVATIVE APPROACH
AS FAR AS DENSE FOG IS CONCERNED AND STUCK WITH PATCHY RATHER THAN +FG
AS THE WINDS HAVE REMAINED ELEVATED THIS MORNING, WHICH COULD LIMIT
THE OVERALL FOG INTENSITY. RECENT LAMP GUIDANCE AND RUC VIS OUTPUT SEEMS
TO AGREE WITH THIS APPROACH AS WELL. FOG CONCERNS WILL BE OVER BY MID
MORNING IF NOT SOONER.
TODAY:
UNPLEASANTLY WARM TEMPERATURES ARE EXPECTED TODAY. I SAY UNPLEASANT
BECAUSE IT WILL FEEL DOWN RIGHT "HOT" RELATIVE TO THE BEGINNING OF APRIL.
I DID TAKE THE COOLER SIDE OF MOS GUIDANCE AS BOISE VERIFICATION STILL
SHOWS A WARM BIAS FROM THE MODELS. ONE REASON AS SUGGESTED FROM YESTERDAYS
DAY SHIFT IS THAT EVAPOTRANSPIRATION FROM A RECENT HEAVY RAINFALL EVENT
IS SLOWING DOWN HEAT FLUXES. IN ADDITION, DEWPOINTS ARE RUNNING AROUND
60 DEG F THIS MORNING SO THE ATMOSPHERE DOES HAVE SOME MOISTURE WHICH
WILL RETARD SENSIBLE HEATING. THESE DEWPOINTS WILL LOWER AS THE DRYLINE
WILL MIX EAST THROUGH THE AFTERNOON. CONVECTION IS NOT EXPECTED ALONG
THE DRYLINE AS UPPER LEVEL RIDGING CONTINUES AND SUBSIDE PREVAILS AHEAD
OF A WESTERN TROUGH. SOME RECORDS COULD BE IN JEOPARDY TODAY WHICH HAS
BEEN HIGHLIGHTED IN THE CLIMATE SECTION BELOW.
ANOTHER CONCERN FOR TODAY IS WINDS. THE 00Z GFS IS STRONGER WITH 850
HPA WINDS COMPARED TO THE 00Z NAM. THE ATMOSPHERE WILL BECOME WELL MIXED
THIS AFTERNOON IN THE WAKE OF THE DRYLINE, HOWEVER WINDS PER THE MESOSCALE
MODELS ARE NOT THAT IMPRESSIVE AND USING MIX DOWN TECHNIQUES SHOWS THAT
A MARGINAL OR SUB MARGINAL WIND ADVISORY SPEEDS ARE POSSIBLE ACROSS
THE WESTERN AND CENTRAL SECTIONS OF THE CWFA TODAY. AS A RESULT, DID
NOT ISSUE A WIND ADVISORY FOR TODAY.
LASTLY, CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TODAY WHICH IS
ADDRESSED BELOW IN THE FIRE WEATHER SECTION.
TONIGHT:
WINDS WILL GRADUALLY VEER OVERNIGHT AHEAD OF AN APPROACHING SIGNIFICANT
COLD FRONT. TEMPERATURES WILL BE MILD AND GENERALLY IN THE 40S DEG F
WEST TO 50S DEG F EAST. NO PRECIPITATION IS EXPECTED DURING THIS TIME FRAME
AS DYNAMICS WILL NOT ARRIVE UNTIL AS DESCRIBED IN THE LONG TERM SECTION.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 243 AM CDT SUN APR 1 2012
MODELS THIS MORNING REMAIN IN GOOD AGREEMENT WITH QUICKLY MOVING
AN UPPER LEVEL TROUGH WHICH WAS LOCATED JUST OFF THE WEST COAST OF
CALIFORNIA TO NEAR THE FOUR CORNERS REGION BY 06Z MONDAY. THIS
UPPER LEVEL SYSTEM THEN DEEPENS AS IT CROSSES NEW MEXICO DURING
THE DAY ON MONDAY. BY 00Z TUESDAY THE GFS, ECMWF, AND NAM ALL
PLACE THIS UPPER LEVEL LOW NEAR EAST CENTRAL NEW MEXICO. AHEAD OF
THIS DEEPENING UPPER LEVEL SYSTEM A COLD FRONT WILL BE MOVING
SOUTH ACROSS WESTERN KANSAS DURING THE DAY AND BASED ON THE GFS
AND NAM THIS FRONTAL BOUNDARY WILL BE LOCATED NEAR THE OKLAHOMA
BORDER AND SOUTH CENTRAL KANSAS BY 00Z TUESDAY. BOTH MODELS THIS
MORNING ARE IN GOOD AGREEMENT WITH CONVECTION DEVELOPING ALONG
THIS COLD FRONT LATE DAY DESPITE THE DIFFERENCES IN THE LOCATION OF
THIS FRONT MONDAY EVENING. THE CONVECTION LATE DAY DOES APPEAR
REASONABLE GIVEN THE MOISTURE RETURN FORECAST AHEAD OF THIS FRONT,
IMPROVING LOW LEVEL FORCING AND LATE DAY INSTABILITY. AS A RESULT WILL
CONTINUE TO FAVOR KEEPING A MENTION OF LATE DAY STORMS ACROSS
SOUTH CENTRAL KANSAS AFTER 21Z. DECENT MID LEVEL INSTABILITY AT
00Z TUESDAY AND CAPES ARE FORECAST TO BE AT OR ABOVE 2000 J/KG.
MARGINAL SHEAR HOWEVER IS EXPECTED WITH 0-6KM SHEAR AT OR BELOW
30KTS. STILL GIVEN SOME LATE DAY HEATING AND IMPROVING FORCING
ALONG THIS BOUNDARY DO THINK A FEW STORMS THAT DO DEVELOP ALONG
THIS FRONT LATE DAY MAY BECOME SEVERE WITH HAIL UP TO QUARTER SIZE
BEING THE MAIN HAZARD.
NORTH/NORTHWEST OF THIS COLD FRONT LATE MONDAY GUSTY
NORTHERLY WINDS ARE EXPECTED TO INCREASE INTO THE 25 TO 35 MPH
RANGE AS AN AREA OF LOW PRESSURE AT THE SURFACE DEEPENS ALONG THIS
COLD FRONT ACROSS THE PANHANDLE OF TEXAS. THIS WILL BEGIN TO USHER
IN SOME COOLER AIR LATE IN THE DAY SO TEMPERATURES BEHIND THIS
COLD FRONT ARE EXPECTED TO STRUGGLE INTO THE UPPER 60S TO LOWER
70S. AHEAD OF THIS FRONT LOWER 80S STILL APPEAR LIKELY.
THE CHANCES FOR PRECIPITATION THEN SPREADS NORTHWARD ACROSS ALL OF
WESTERN AND MUCH OF NORTH CENTRAL KANSAS MONDAY NIGHT AS THE UPPER
LEVEL LOW BEGINS TO LOWLY MOVE EAST INTO THE PANHANDLE OF TEXAS
AND WARM AIR ADVECTION AND MOISTURE IMPROVES ACROSS WESTERN KANSAS
DURING THE OVERNIGHT HOURS MONDAY NIGHT.
FROM TUESDAY THROUGH EARLY WEDNESDAY A SERIES OF UPPER LEVEL
DISTURBANCES WILL ROTATE AROUND THIS UPPER LOW AS IT MOVES FROM
THE PANHANDLE OF TEXAS INTO SOUTH CENTRAL KANSAS. MOISTURE AND
LIFT (WARM AIR ADVECTION, ISENTROPIC LIFT, 850-700MB
FRONTOGENESIS) CONTINUES SO HAVE THEREFORE RAISE PRECIPITATION
CHANCES ACROSS THE ENTIRE AREA.
BY LATE WEDNESDAY AN UPPER LEVEL SHORT WAVE RIDGE WILL BEGIN TO
BUILD INTO THE ROCKIES AS THE UPPER LOW CONTINUES TO TRACK
EASTWARD ACROSS EASTERN KANSAS. SKIES ARE EXPECTED TO CLEAR FROM
WEST TO EAST AS THE PRECIPITATION ENDS. TEMPERATURES WEDNESDAY
NIGHT HAS THE POTENTIAL TO FALL BACK TO NEAR FREEZING IF SKIES
CLEAR QUICK ENOUGH AND WIND GO LIGHT BUT GIVEN THE TIMING ISSUES
OF THE UPPER LOW HAVE DECIDED TO STAY CLOSE TO LATEST ALLBLEND.
ON THURSDAY AND FRIDAY A WARMING TREND CAN BE EXPECTED ACROSS
WESTERN KANSAS AS THE UPPER LEVEL RIDGE AXIS BUILDS EAST OUT INTO
THE PLAINS AND WESTERLY DOWN SLOPE FLOW IMPROVES
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1201 AM CDT SUN APR 1 2012
TWO CONCERNS FOR THE 06Z TAFS. FOG AND WINDS. THE 01/02Z HRRR IS
MOST AGGRESSIVE IN BRINGING DENSE FOG ACROSS SOUTH CENTRAL KANSAS BY
MORNING. THIS MODEL WAS FAIRLY ACCURATE LAST NIGHT ALTHOUGH A LITTLE
TOO LOW ON VIS. THE RUC ALSO SHOWS LOWERED VIS GENERALLY IN THE SAME
AREA. DON`T HAVE ENOUGH CONFIDENCE FOR LIFR CIGS BUT HAVE LOWERED CIGS
FROM VFR TO MVFR TO START OUT ON THE CONSERVATIVE SIDE SINCE THE HRRR
OVERDID IT LAST NIGHT. SECOND CONCERN IS WINDS. HAVE INCREASED SW WINDS
20-25 KT WITH GUSTS TO 30-35 KT AS THE LEE SFC TROUGH STRENGTHENS TOMORROW
AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 333 AM CDT SUN APR 1 2012
AFTER COORDINATION WITH SURROUNDING WFO`S, HAVE CONTINUED THE RFW TODAY
AND ADDED CLARK COUNTY IN. THE EASTERN COLUMN OF COUNTIES IS A BIT MARGINAL
AS RH`S WILL BE IN THE 15 TO 17 PERCENT RANGE. DECIDED TO ERROR ON THE
SIDE OF CAUTION AND KEEP THE COUNTIES IN THE WARNING AS TODAYS HIGHS
WILL BE VERY WARM AND THE MODELS TYPICALLY UNDER FORECAST DEWPOINTS
IN ASSOCIATION WITH A MIXING DRYLINE AND ADIABATIC COMPRESSIONAL WARMING.
&&
.CLIMATE...
ISSUED AT 333 AM CDT SUN APR 1 2012
A VERY ANOMALOUS DAY OF EXTREMELY WARM TEMPERATURES IS EXPECTED TODAY.
POSITIVE TEMPERATURE DEVIATIONS OF 20 TO 30 DEGREES IS LIKELY ACROSS
SOUTHWEST AND SOUTH CENTRAL KANSAS. SOME RECORDS COULD BE BROKEN TODAY.
CLIMATE RECORDS IS AS FOLLOWS:
RECORD (YEAR)..........................FORECAST HIGH FOR TODAY
DODGE CITY: 88 (1940, 1964)............89
MEDICINE LODGE: 93 (1946)..............86
GARDEN CITY: 87 (1964).................90
ELKHART 89 (1946)......................90
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 89 52 74 41 / 0 10 10 60
GCK 90 50 69 40 / 0 10 10 50
EHA 90 49 66 38 / 0 10 20 50
LBL 90 50 71 40 / 0 10 20 50
HYS 88 54 72 41 / 0 10 10 50
P28 86 57 82 51 / 0 10 40 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON CDT /11 AM MDT/ TODAY TO 9 PM CDT /8
PM MDT/ THIS EVENING FOR KSZ030-043>045-061>064-074>078-084>088.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....BURGERT
AVIATION...SUGDEN
FIRE WEATHER...SUGDEN
CLIMATE...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
333 AM CDT SUN APR 1 2012
...UPDATED SYNOPSIS/SHORT TERM/FIRE WEATHER/CLIMATE DISCUSSIONS...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 333 AM CDT SUN APR 1 2012
.SYNOPSIS...
ISSUED AT 333 AM CDT SUN APR 1 2012
THE APRIL 1 2012 00Z 300 HPA SYNOPTIC MAP SHOWED A LARGE ANTICYCLONIC
CURVED JET EXTENDING ACROSS THE WESTERN UNITED STATES AND INTO THE CANADIAN
PRAIRIE PROVINCES. A JET STREAK OF AROUND 130-140 KT WAS OBSERVED FROM
KREV TO KBOI. AT 500 HPA, AN AMPLIFIED TROUGH ASSOCIATED WITH THE JET
STREAK WAS LOCATED ACROSS THE PACIFIC NORTHWEST AND INTO NORTHERN CALIFORNIA.
CONSIDERABLE COLD AIR ADVECTION WITH 500 HPA DELTA TEMPERATURES AROUND
10 DEG C WAS OBSERVED ACROSS THE PACIFIC NORTHWEST ALONG WITH SIGNIFICANT
HEIGHT FALLS. MORE LOCALLY AND AT LOWER LEVELS, A WARM AND DRY PLUME
AT 700 AND 850 HPA PREVAILED ACROSS THE HIGH PLAINS. AT THE SFC, A LOW
PRESSURE CENTER WAS LOCATED ACROSS EASTERN COLORADO. A DRYLINE ASSOCIATED
WITH THIS FEATURE WAS LOCATED ACROSS THE SOUTHERN HIGH PLAINS AS WELL.
THIS MORNING:
AS WITH LAST NIGHT, HAVE FOLLOWED HRRR GUIDANCE IN CONCERNING THE POTENTIAL
FOR PATCHY FOG FORMATION THIS MORNING. THIS MODEL HAS BEEN TRENDING
WELL AS SITES AROUND KANSAS AND OKLAHOMA HAVE BEEN REPORTING BR THROUGH
THE OVERNIGHT HOURS. I DID, HOWEVER, TAKE A MORE CONSERVATIVE APPROACH
AS FAR AS DENSE FOG IS CONCERNED AND STUCK WITH PATCHY RATHER THAN +FG
AS THE WINDS HAVE REMAINED ELEVATED THIS MORNING, WHICH COULD LIMIT
THE OVERALL FOG INTENSITY. RECENT LAMP GUIDANCE AND RUC VIS OUTPUT SEEMS
TO AGREE WITH THIS APPROACH AS WELL. FOG CONCERNS WILL BE OVER BY MID
MORNING IF NOT SOONER.
TODAY:
UNPLEASANTLY WARM TEMPERATURES ARE EXPECTED TODAY. I SAY UNPLEASANT
BECAUSE IT WILL FEEL DOWN RIGHT "HOT" RELATIVE TO THE BEGINNING OF APRIL.
I DID TAKE THE COOLER SIDE OF MOS GUIDANCE AS BOISE VERIFICATION STILL
SHOWS A WARM BIAS FROM THE MODELS. ONE REASON AS SUGGESTED FROM YESTERDAYS
DAY SHIFT IS THAT EVAPOTRANSPIRATION FROM A RECENT HEAVY RAINFALL EVENT
IS SLOWING DOWN HEAT FLUXES. IN ADDITION, DEWPOINTS ARE RUNNING AROUND
60 DEG F THIS MORNING SO THE ATMOSPHERE DOES HAVE SOME MOISTURE WHICH
WILL RETARD SENSIBLE HEATING. THESE DEWPOINTS WILL LOWER AS THE DRYLINE
WILL MIX EAST THROUGH THE AFTERNOON. CONVECTION IS NOT EXPECTED ALONG
THE DRYLINE AS UPPER LEVEL RIDGING CONTINUES AND SUBSIDE PREVAILS AHEAD
OF A WESTERN TROUGH. SOME RECORDS COULD BE IN JEOPARDY TODAY WHICH HAS
BEEN HIGHLIGHTED IN THE CLIMATE SECTION BELOW.
ANOTHER CONCERN FOR TODAY IS WINDS. THE 00Z GFS IS STRONGER WITH 850
HPA WINDS COMPARED TO THE 00Z NAM. THE ATMOSPHERE WILL BECOME WELL MIXED
THIS AFTERNOON IN THE WAKE OF THE DRYLINE, HOWEVER WINDS PER THE MESOSCALE
MODELS ARE NOT THAT IMPRESSIVE AND USING MIX DOWN TECHNIQUES SHOWS THAT
A MARGINAL OR SUB MARGINAL WIND ADVISORY SPEEDS ARE POSSIBLE ACROSS
THE WESTERN AND CENTRAL SECTIONS OF THE CWFA TODAY. AS A RESULT, DID
NOT ISSUE A WIND ADVISORY FOR TODAY.
LASTLY, CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TODAY WHICH IS
ADDRESSED BELOW IN THE FIRE WEATHER SECTION.
TONIGHT:
WINDS WILL GRADUALLY VEER OVERNIGHT AHEAD OF AN APPROACHING SIGNIFICANT
COLD FRONT. TEMPERATURES WILL BE MILD AND GENERALLY IN THE 40S DEG F
WEST TO 50S DEG F EAST. NO PRECIPITATION IS EXPECTED DURING THIS TIME FRAME
AS DYNAMICS WILL NOT ARRIVE UNTIL AS DESCRIBED IN THE LONG TERM SECTION.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 335 PM CDT SAT MAR 31 2012
ON MONDAY AN ELONGATED UPPER LEVEL TROUGH WILL BEGIN TO GET CUTOFF
AT THE BASE JUST SOUTH OF THE FOUR CORNERS REGION AND MOVE INTO
NORTHEASTERN NEW MEXICO. THIS WILL ALLOW A COLD FRONT TO SURGE INTO
SOUTHWESTERN KANSAS ON MONDAY MORNING, THEN ACROSS MUCH OF SOUTH
CENTRAL KANSAS BY EVENING TO NEAR MEDICINE LODGE. PREFER THE
FASTER FRONTAL MOVEMENT OF THE NAM/GFS THAN THE ECMWF BECAUSE OF
THE STRONGER NORTHERN BRANCH WAVE MOVING ACROSS THE DAKOTAS. A FEW
THUNDERSTORMS WILL BE POSSIBLE IN THE AFTERNOON ALONG AND AHEAD OF
THE COLD FRONT, MAINLY EAST OF LINE FROM COLDWATER TO SAINT JOHN.
IF STORMS FORM A FEW COULD HAVE SOME SMALL HAIL. HOWEVER IF THE
FRONT DELAYS THE STORMS COULD BE STRONGER NEAR A COLD FRONT
AND DRYLINE INTERSECTION. AHEAD OF THE COLD FRONT LOWS WILL BE
MILD AND INTO THE UPPER 40S NORTHEAST AND MID 50S SOUTHEAST FA.
HIGH TEMPERATURES ON MONDAY WILL RANGE FROM THE 60S NORTHWEST TO
THE LOW TO MID 80S SOUTHEAST FA.
FOR TUESDAY THE UPPER LOW MOVES NORTHEASTWARD SLOWLY INTO THE TEXAS
PANHANDLE AND PARTS OF FAR SOUTHWESTERN KANSAS. THE GEM AND THE
ECMWF ARE A BIT FASTER WITH THE UPPER LOW THAN THE GFS. RAIN SHOWERS
AND A FEW THUNDERSTORMS WILL RAPIDLY SPREAD NORTH AHEAD OF THE UPPER
LOW INTO SOUTHWEST AND SOUTH CENTRAL KANSAS. THE BEST CHANCES WILL
OCCUR AFTER MIDNIGHT. A CHANCE FOR THUNDERSTORMS WITH SOME ELEVATED
CAPE WILL BE MAINLY EAST OF A LINE FROM LARNED TO ASHLAND. SEVERE
WEATHER IS NOT EXPECTED. LOWS ON TUESDAY MORNING LOOK TO BE IN THE
UPPER 30S WEST TO NEAR 50 EAST FA. HIGHS ON TUESDAY WILL RANGE FROM
NEAR 50 IN THE FAR WEST TO THE LOW TO MID 60S FAR EAST FA.
ON WEDNESDAY THE UPPER LOW CONTINUES TO MOVE NORTHEAST AND INTO
EASTERN KANSAS AND OKLAHOMA. LOWS IN MORNING WILL BE IN THE UPPER
30S FAR WEST TO THE MID AND UPPER 40S EAST. HIGH TEMPERATURES WILL
RANGE FROM THE MID 60S WEST TO AROUND 60 NORTHEAST. RAIN CHANCES
DIMINISH FROM WEST TO EAST WITH THE UPPER LOW. TOTAL RAINFALL
COULD RANGE FROM ONE QUARTER TO OVER ONE HALF INCH WITH THE
HIGHEST IN THE SOUTHEASTERN FA FROM LARNED TO ASHLAND.
FOR THURSDAY THE UPPER LEVEL SHORTWAVE RIDGING WILL MOVE INTO THE
PLAINS WITH A WARM UP BACK INTO THE 70S.
ANOTHER UPPER LEVEL SHORTWAVE TROUGH WILL MOVE RAPIDLY NORTHEASTWARD
ACROSS THE NORTHERN AND CENTRAL PLAINS FOR FRIDAY PUSHING ANOTHER
COLD FRONT ACROSS KANSAS ON SATURDAY AS IT MOVES INTO THE NORTHERN
HIGH PLAINS. LITTLE IF ANY RAINFALL IS EXPECTED. HIGHS ON FRIDAY
LOOK TO BE IN THE MID TO UPPER 70S WITH SLIGHTLY COOLER TEMPS ON
SATURDAY TO AROUND 70. OVERNIGHT LOWS WILL BE IN THE 40S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1201 AM CDT SUN APR 1 2012
TWO CONCERNS FOR THE 06Z TAFS. FOG AND WINDS. THE 01/02Z HRRR IS
MOST AGGRESSIVE IN BRINGING DENSE FOG ACROSS SOUTH CENTRAL KANSAS BY
MORNING. THIS MODEL WAS FAIRLY ACCURATE LAST NIGHT ALTHOUGH A LITTLE
TOO LOW ON VIS. THE RUC ALSO SHOWS LOWERED VIS GENERALLY IN THE SAME
AREA. DON`T HAVE ENOUGH CONFIDENCE FOR LIFR CIGS BUT HAVE LOWERED CIGS
FROM VFR TO MVFR TO START OUT ON THE CONSERVATIVE SIDE SINCE THE HRRR
OVERDID IT LAST NIGHT. SECOND CONCERN IS WINDS. HAVE INCREASED SW WINDS
20-25 KT WITH GUSTS TO 30-35 KT AS THE LEE SFC TROUGH STRENGTHENS TOMORROW
AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 333 AM CDT SUN APR 1 2012
AFTER COORDINATION WITH SURROUNDING WFO`S, HAVE CONTINUED THE RFW TODAY
AND ADDED CLARK COUNTY IN. THE EASTERN COLUMN OF COUNTIES IS A BIT MARGINAL
AS RH`S WILL BE IN THE 15 TO 17 PERCENT RANGE. DECIDED TO ERROR ON THE
SIDE OF CAUTION AND KEEP THE COUNTIES IN THE WARNING AS TODAYS HIGHS
WILL BE VERY WARM AND THE MODELS TYPICALLY UNDER FORECAST DEWPOINTS
IN ASSOCIATION WITH A MIXING DRYLINE AND ADIABATIC COMPRESSIONAL WARMING.
&&
.CLIMATE...
ISSUED AT 333 AM CDT SUN APR 1 2012
A VERY ANOMALOUS DAY OF EXTREMELY WARM TEMPERATURES IS EXPECTED TODAY.
POSITIVE TEMPERATURE DEVIATIONS OF 20 TO 30 DEGREES IS LIKELY ACROSS
SOUTHWEST AND SOUTH CENTRAL KANSAS. SOME RECORDS COULD BE BROKEN TODAY.
CLIMATE RECORDS IS AS FOLLOWS:
RECORD (YEAR)..........................FORECAST HIGH FOR TODAY
DODGE CITY: 88 (1940, 1964)............89
MEDICINE LODGE: 93 (1946)..............86
GARDEN CITY: 87 (1964).................90
ELKHART 89 (1946)......................90
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 89 52 74 41 / 0 10 10 60
GCK 90 50 69 40 / 0 10 10 50
EHA 90 49 66 38 / 0 10 20 50
LBL 90 50 71 40 / 0 10 20 50
HYS 88 54 72 41 / 0 10 10 50
P28 86 57 82 51 / 0 10 40 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON CDT /11 AM MDT/ TODAY TO 9 PM CDT /8
PM MDT/ THIS EVENING FOR KSZ030-043>045-061>064-074>078-084>088.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....KRUSE
AVIATION...SUGDEN
FIRE WEATHER...SUGDEN
CLIMATE...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
247 AM CDT SUN APR 1 2012
...UPDATED LONG TERM DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 321 PM CDT SAT MAR 31 2012
THE PRIMARY FORECAST CHALLENGES IN THE SHORT TERM ARE THE FOLLOWING:
1) EVALUATING THE PROBABILITY FOR PATCHY DENSE FOG SUNDAY MORNING IN
THE RICH BUT SHALLOW LOW LEVEL MOISTURE FIELD IN SOUTH CENTRAL
KANSAS; 2) DETERMINING HOW FAR EAST THE DRYLINE WILL PROGRESS ON
SUNDAY AS CYCLOGENESIS OCCURS IN EASTERN COLORADO; 3) DETERMINING
THE AREA WHERE RED FLAG CONDITIONS WILL BE MET SUNDAY AFTERNOON; AND
4) ANTICIPATING TEMPERATURES IN THE ANOMALOUSLY WARM AIR SUNDAY
AFTERNOON.
A MADDEN-JULIAN OSCILLATION CONTINUES TO MOVE DOWN THE SOUTH PACIFIC
CONVERGENCE ZONE FROM NORTH OF AUSTRALIA INTO THE TROPICAL SOUTH
PACIFIC. A TROPICAL CYCLONE WAS IN PROGRESS EAST OF VIET NAM ON THE
TRAILING EDGE OF THE MADDEN-JULIAN OSCILLATION. THE GLOBAL MODELS
ARE IN GOOD AGREEMENT IN MOVING THE MADDEN-JULIAN OSCILLATION INTO
PHASE 8 OF THE WHEELER-HENDON PHASE SPACE DIAGRAM BY AROUND EASTER,
AND THIS PATTERN FAVORS ANTICYCLONIC FLOW ALOFT IN THE NORTHERN
ROCKIES. THE MODEL SOLUTIONS OF A SPLIT FLOW WITH AN
ANTICYCLONICALLY BREAKING UPPER LEVEL CYCLONE WALLOWING INTO THE
CENTRAL PART OF THE COUNTRY FOLLOWED BY A BUILDING RIDGE BACK INTO
THE NORTHERN ROCKIES NEXT WEEKEND SEEM VERY REASONABLE.
IN THE SHORTER TERM, THE MODELS ARE IN GOOD AGREEMENT WITH DIGGING
THE SOUTHERN PART OF THE STRONG TROUGH INTO ARIZONA BY SUNDAY
EVENING WHILE THE NORTHERN PORTION OF THE TROUGH LIFTS OUT INTO
SASKATCHEWAN IN THE NORTHERN BRANCH OF THE WESTERLIES. THERE ALWAYS
IS UNCERTAINTY ON HOW CLOSED UPPER LEVEL CYCLONES WILL EVOLVE WITH
TIME, BUT THE SLOWER GFS SOLUTION PROBABLY IS FAIRLY GOOD. THE GFS
LARGELY WAS USED FOR GRID MODIFICATIONS THROUGH SUNDAY.
PRESSURES ALREADY ARE FALLING IN THE LEE OF THE ROCKIES THIS
AFTERNOON, AND THE TROUGH WILL CONTINUE TO DEEPEN TONIGHT. LOW LEVEL
MOISTURE WILL SLOSH BACK WESTWARD TONIGHT AS THE LOW LEVEL WINDS
BACK, BUT THE MOISTURE FIELD WILL BE RATHER SHALLOW ACROSS MOST OF
WESTERN KANSAS. BY SUNRISE, VEERING LOW LEVEL FLOW WILL BEGIN TO
ERODE THE MOISTURE IN FAR WESTERN KANSAS, AND THE DRYLINE GRADUALLY
WILL MIX EASTWARD DURING THE DAY. THE RICHEST LOW LEVEL MOISTURE
WILL BE IN SOUTH CENTRAL KANSAS TONIGHT WITH DRY AIR ABOVE THE MOIST
LAYER. LOW LEVEL WINDS WILL BE RELATIVELY LIGHT IN SOUTH CENTRAL
KANSAS, AND THE MOISTURE MAY BE DEEP ENOUGH THAT THE HYDROLAPSE WILL
FAVOR PATCHY FOG FORMATION BY SUNRISE. WHATEVER FOG DOES FORM WILL
BURN OFF QUICKLY AS WINDS INCREASE DURING THE EARLY MORNING
HOURS.
PRESSURES WILL CONTINUE TO FALL IN THE LEE OF THE ROCKIES SUNDAY AS
CYCLOGENESIS OCCURS IN NORTHEASTERN COLORADO. THE SHALLOW MOISTURE
WILL MIX OUT AT LEAST AS FAR EAST AS DODGE CITY BY MID AFTERNOON,
AND A VERY DEEPLY MIXED BOUNDARY LAYER WILL EVOLVE DURING THE DAY.
H8 WINDS WILL INCREASE TO 30-35 KNOTS BY LATE MORNING, SO
SURFACE WINDS IN THE 20 TO 25 KNOT RANGE WITH GUSTS INTO THE 30-35
KNOT RANGE SEEM REASONABLE. H8 DEWPOINTS WILL DROP TO NEAR -10C IN
FAR WESTERN KANSAS WITH VALUES NEAR 0C AS FAR EAST AS DODGE CITY.
WITH H8 TEMPERATURES ABOVE 25C IN THE DRY AIR, SURFACE TEMPERATURES
WILL APPROACH RECORDS IN A FEW LOCATIONS. EVAPOTRANSPIRATION FROM
VEGETATION MAY SHAVE TWO OR THREE DEGREES OFF MAXIMUM TEMPERATURES,
BUT HIGHS NEAR 90 DEGREES ARE LIKELY. WINDS MAY APPROACH ADVISORY
CRITERIA BY MID AFTERNOON AND WILL HAVE TO BE MONITORED FOR POSSIBLE
HEADLINES BY SUBSEQUENT SHIFTS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 243 AM CDT SUN APR 1 2012
MODELS THIS MORNING REMAIN IN GOOD AGREEMENT WITH QUICKLY MOVING
AN UPPER LEVEL TROUGH WHICH WAS LOCATED JUST OFF THE WEST COAST OF
CALIFORNIA TO NEAR THE FOUR CORNERS REGION BY 06Z MONDAY. THIS
UPPER LEVEL SYSTEM THEN DEEPENS AS IT CROSSES NEW MEXICO DURING
THE DAY ON MONDAY. BY 00Z TUESDAY THE GFS, ECMWF, AND NAM ALL
PLACE THIS UPPER LEVEL LOW NEAR EAST CENTRAL NEW MEXICO. AHEAD OF
THIS DEEPENING UPPER LEVEL SYSTEM A COLD FRONT WILL BE MOVING
SOUTH ACROSS WESTERN KANSAS DURING THE DAY AND BASED ON THE GFS
AND NAM THIS FRONTAL BOUNDARY WILL BE LOCATED NEAR THE OKLAHOMA
BORDER AND SOUTH CENTRAL KANSAS BY 00Z TUESDAY. BOTH MODELS THIS
MORNING ARE IN GOOD AGREEMENT WITH CONVECTION DEVELOPING ALONG
THIS COLD FRONT LATE DAY DESPITE THE DIFFERENCES IN THE LOCATION OF
THIS FRONT MONDAY EVENING. THE CONVECTION LATE DAY DOES APPEAR
REASONABLE GIVEN THE MOISTURE RETURN FORECAST AHEAD OF THIS FRONT,
IMPROVING LOW LEVEL FORCING AND LATE DAY INSTABILITY. AS A RESULT WILL
CONTINUE TO FAVOR KEEPING A MENTION OF LATE DAY STORMS ACROSS
SOUTH CENTRAL KANSAS AFTER 21Z. DECENT MID LEVEL INSTABILITY AT
00Z TUESDAY AND CAPES ARE FORECAST TO BE AT OR ABOVE 2000 J/KG.
MARGINAL SHEAR HOWEVER IS EXPECTED WITH 0-6KM SHEAR AT OR BELOW
30KTS. STILL GIVEN SOME LATE DAY HEATING AND IMPROVING FORCING
ALONG THIS BOUNDARY DO THINK A FEW STORMS THAT DO DEVELOP ALONG
THIS FRONT LATE DAY MAY BECOME SEVERE WITH HAIL UP TO QUARTER SIZE
BEING THE MAIN HAZARD.
NORTH/NORTHWEST OF THIS COLD FRONT LATE MONDAY GUSTY
NORTHERLY WINDS ARE EXPECTED TO INCREASE INTO THE 25 TO 35 MPH
RANGE AS AN AREA OF LOW PRESSURE AT THE SURFACE DEEPENS ALONG THIS
COLD FRONT ACROSS THE PANHANDLE OF TEXAS. THIS WILL BEGIN TO USHER
IN SOME COOLER AIR LATE IN THE DAY SO TEMPERATURES BEHIND THIS
COLD FRONT ARE EXPECTED TO STRUGGLE INTO THE UPPER 60S TO LOWER
70S. AHEAD OF THIS FRONT LOWER 80S STILL APPEAR LIKELY.
THE CHANCES FOR PRECIPITATION THEN SPREADS NORTHWARD ACROSS ALL OF
WESTERN AND MUCH OF NORTH CENTRAL KANSAS MONDAY NIGHT AS THE UPPER
LEVEL LOW BEGINS TO LOWLY MOVE EAST INTO THE PANHANDLE OF TEXAS
AND WARM AIR ADVECTION AND MOISTURE IMPROVES ACROSS WESTERN KANSAS
DURING THE OVERNIGHT HOURS MONDAY NIGHT.
FROM TUESDAY THROUGH EARLY WEDNESDAY A SERIES OF UPPER LEVEL
DISTURBANCES WILL ROTATE AROUND THIS UPPER LOW AS IT MOVES FROM
THE PANHANDLE OF TEXAS INTO SOUTH CENTRAL KANSAS. MOISTURE AND
LIFT (WARM AIR ADVECTION, ISENTROPIC LIFT, 850-700MB
FRONTOGENESIS) CONTINUES SO HAVE THEREFORE RAISE PRECIPITATION
CHANCES ACROSS THE ENTIRE AREA.
BY LATE WEDNESDAY AN UPPER LEVEL SHORT WAVE RIDGE WILL BEGIN TO
BUILD INTO THE ROCKIES AS THE UPPER LOW CONTINUES TO TRACK
EASTWARD ACROSS EASTERN KANSAS. SKIES ARE EXPECTED TO CLEAR FROM
WEST TO EAST AS THE PRECIPITATION ENDS. TEMPERATURES WEDNESDAY
NIGHT HAS THE POTENTIAL TO FALL BACK TO NEAR FREEZING IF SKIES
CLEAR QUICK ENOUGH AND WIND GO LIGHT BUT GIVEN THE TIMING ISSUES
OF THE UPPER LOW HAVE DECIDED TO STAY CLOSE TO LATEST ALLBLEND.
ON THURSDAY AND FRIDAY A WARMING TREND CAN BE EXPECTED ACROSS
WESTERN KANSAS AS THE UPPER LEVEL RIDGE AXIS BUILDS EAST OUT INTO
THE PLAINS AND WESTERLY DOWN SLOPE FLOW IMPROVES
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1201 AM CDT SUN APR 1 2012
TWO CONCERNS FOR THE 06Z TAFS. FOG AND WINDS. THE 01/02Z HRRR IS
MOST AGGRESSIVE IN BRINGING DENSE FOG ACROSS SOUTH CENTRAL KANSAS BY
MORNING. THIS MODEL WAS FAIRLY ACCURATE LAST NIGHT ALTHOUGH A LITTLE
TOO LOW ON VIS. THE RUC ALSO SHOWS LOWERED VIS GENERALLY IN THE SAME
AREA. DON`T HAVE ENOUGH CONFIDENCE FOR LIFR CIGS BUT HAVE LOWERED CIGS
FROM VFR TO MVFR TO START OUT ON THE CONSERVATIVE SIDE SINCE THE HRRR
OVERDID IT LAST NIGHT. SECOND CONCERN IS WINDS. HAVE INCREASED SW WINDS
20-25 KT WITH GUSTS TO 30-35 KT AS THE LEE SFC TROUGH STRENGTHENS TOMORROW
AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 89 52 74 41 / 0 10 10 60
GCK 90 50 69 40 / 0 10 10 50
EHA 90 49 66 38 / 0 10 20 50
LBL 90 50 71 40 / 0 10 20 50
HYS 88 54 72 41 / 0 10 10 50
P28 86 57 82 51 / 0 10 40 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON CDT /11 AM MDT/ TODAY TO 9 PM CDT /8
PM MDT/ THIS EVENING FOR KSZ030-043>045-061>064-074>078-084>088.
&&
$$
UPDATE...RUTHI
SYNOPSIS...RUTHI
SHORT TERM...RUTHI
LONG TERM....BURGERT
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1208 AM CDT SUN APR 1 2012
...UPDATE TO AVIATION FOR 06Z TAFS...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 321 PM CDT SAT MAR 31 2012
THE PRIMARY FORECAST CHALLENGES IN THE SHORT TERM ARE THE FOLLOWING:
1) EVALUATING THE PROBABILITY FOR PATCHY DENSE FOG SUNDAY MORNING IN
THE RICH BUT SHALLOW LOW LEVEL MOISTURE FIELD IN SOUTH CENTRAL
KANSAS; 2) DETERMINING HOW FAR EAST THE DRYLINE WILL PROGRESS ON
SUNDAY AS CYCLOGENESIS OCCURS IN EASTERN COLORADO; 3) DETERMINING
THE AREA WHERE RED FLAG CONDITIONS WILL BE MET SUNDAY AFTERNOON; AND
4) ANTICIPATING TEMPERATURES IN THE ANOMALOUSLY WARM AIR SUNDAY
AFTERNOON.
A MADDEN-JULIAN OSCILLATION CONTINUES TO MOVE DOWN THE SOUTH PACIFIC
CONVERGENCE ZONE FROM NORTH OF AUSTRALIA INTO THE TROPICAL SOUTH
PACIFIC. A TROPICAL CYCLONE WAS IN PROGRESS EAST OF VIET NAM ON THE
TRAILING EDGE OF THE MADDEN-JULIAN OSCILLATION. THE GLOBAL MODELS
ARE IN GOOD AGREEMENT IN MOVING THE MADDEN-JULIAN OSCILLATION INTO
PHASE 8 OF THE WHEELER-HENDON PHASE SPACE DIAGRAM BY AROUND EASTER,
AND THIS PATTERN FAVORS ANTICYCLONIC FLOW ALOFT IN THE NORTHERN
ROCKIES. THE MODEL SOLUTIONS OF A SPLIT FLOW WITH AN
ANTICYCLONICALLY BREAKING UPPER LEVEL CYCLONE WALLOWING INTO THE
CENTRAL PART OF THE COUNTRY FOLLOWED BY A BUILDING RIDGE BACK INTO
THE NORTHERN ROCKIES NEXT WEEKEND SEEM VERY REASONABLE.
IN THE SHORTER TERM, THE MODELS ARE IN GOOD AGREEMENT WITH DIGGING
THE SOUTHERN PART OF THE STRONG TROUGH INTO ARIZONA BY SUNDAY
EVENING WHILE THE NORTHERN PORTION OF THE TROUGH LIFTS OUT INTO
SASKATCHEWAN IN THE NORTHERN BRANCH OF THE WESTERLIES. THERE ALWAYS
IS UNCERTAINTY ON HOW CLOSED UPPER LEVEL CYCLONES WILL EVOLVE WITH
TIME, BUT THE SLOWER GFS SOLUTION PROBABLY IS FAIRLY GOOD. THE GFS
LARGELY WAS USED FOR GRID MODIFICATIONS THROUGH SUNDAY.
PRESSURES ALREADY ARE FALLING IN THE LEE OF THE ROCKIES THIS
AFTERNOON, AND THE TROUGH WILL CONTINUE TO DEEPEN TONIGHT. LOW LEVEL
MOISTURE WILL SLOSH BACK WESTWARD TONIGHT AS THE LOW LEVEL WINDS
BACK, BUT THE MOISTURE FIELD WILL BE RATHER SHALLOW ACROSS MOST OF
WESTERN KANSAS. BY SUNRISE, VEERING LOW LEVEL FLOW WILL BEGIN TO
ERODE THE MOISTURE IN FAR WESTERN KANSAS, AND THE DRYLINE GRADUALLY
WILL MIX EASTWARD DURING THE DAY. THE RICHEST LOW LEVEL MOISTURE
WILL BE IN SOUTH CENTRAL KANSAS TONIGHT WITH DRY AIR ABOVE THE MOIST
LAYER. LOW LEVEL WINDS WILL BE RELATIVELY LIGHT IN SOUTH CENTRAL
KANSAS, AND THE MOISTURE MAY BE DEEP ENOUGH THAT THE HYDROLAPSE WILL
FAVOR PATCHY FOG FORMATION BY SUNRISE. WHATEVER FOG DOES FORM WILL
BURN OFF QUICKLY AS WINDS INCREASE DURING THE EARLY MORNING
HOURS.
PRESSURES WILL CONTINUE TO FALL IN THE LEE OF THE ROCKIES SUNDAY AS
CYCLOGENESIS OCCURS IN NORTHEASTERN COLORADO. THE SHALLOW MOISTURE
WILL MIX OUT AT LEAST AS FAR EAST AS DODGE CITY BY MID AFTERNOON,
AND A VERY DEEPLY MIXED BOUNDARY LAYER WILL EVOLVE DURING THE DAY.
H8 WINDS WILL INCREASE TO 30-35 KNOTS BY LATE MORNING, SO
SURFACE WINDS IN THE 20 TO 25 KNOT RANGE WITH GUSTS INTO THE 30-35
KNOT RANGE SEEM REASONABLE. H8 DEWPOINTS WILL DROP TO NEAR -10C IN
FAR WESTERN KANSAS WITH VALUES NEAR 0C AS FAR EAST AS DODGE CITY.
WITH H8 TEMPERATURES ABOVE 25C IN THE DRY AIR, SURFACE TEMPERATURES
WILL APPROACH RECORDS IN A FEW LOCATIONS. EVAPOTRANSPIRATION FROM
VEGETATION MAY SHAVE TWO OR THREE DEGREES OFF MAXIMUM TEMPERATURES,
BUT HIGHS NEAR 90 DEGREES ARE LIKELY. WINDS MAY APPROACH ADVISORY
CRITERIA BY MID AFTERNOON AND WILL HAVE TO BE MONITORED FOR POSSIBLE
HEADLINES BY SUBSEQUENT SHIFTS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 335 PM CDT SAT MAR 31 2012
ON MONDAY AN ELONGATED UPPER LEVEL TROUGH WILL BEGIN TO GET CUTOFF
AT THE BASE JUST SOUTH OF THE FOUR CORNERS REGION AND MOVE INTO
NORTHEASTERN NEW MEXICO. THIS WILL ALLOW A COLD FRONT TO SURGE INTO
SOUTHWESTERN KANSAS ON MONDAY MORNING, THEN ACROSS MUCH OF SOUTH
CENTRAL KANSAS BY EVENING TO NEAR MEDICINE LODGE. PREFER THE
FASTER FRONTAL MOVEMENT OF THE NAM/GFS THAN THE ECMWF BECAUSE OF
THE STRONGER NORTHERN BRANCH WAVE MOVING ACROSS THE DAKOTAS. A FEW
THUNDERSTORMS WILL BE POSSIBLE IN THE AFTERNOON ALONG AND AHEAD OF
THE COLD FRONT, MAINLY EAST OF LINE FROM COLDWATER TO SAINT JOHN.
IF STORMS FORM A FEW COULD HAVE SOME SMALL HAIL. HOWEVER IF THE
FRONT DELAYS THE STORMS COULD BE STRONGER NEAR A COLD FRONT
AND DRYLINE INTERSECTION. AHEAD OF THE COLD FRONT LOWS WILL BE
MILD AND INTO THE UPPER 40S NORTHEAST AND MID 50S SOUTHEAST FA.
HIGH TEMPERATURES ON MONDAY WILL RANGE FROM THE 60S NORTHWEST TO
THE LOW TO MID 80S SOUTHEAST FA.
FOR TUESDAY THE UPPER LOW MOVES NORTHEASTWARD SLOWLY INTO THE TEXAS
PANHANDLE AND PARTS OF FAR SOUTHWESTERN KANSAS. THE GEM AND THE
ECMWF ARE A BIT FASTER WITH THE UPPER LOW THAN THE GFS. RAIN SHOWERS
AND A FEW THUNDERSTORMS WILL RAPIDLY SPREAD NORTH AHEAD OF THE UPPER
LOW INTO SOUTHWEST AND SOUTH CENTRAL KANSAS. THE BEST CHANCES WILL
OCCUR AFTER MIDNIGHT. A CHANCE FOR THUNDERSTORMS WITH SOME ELEVATED
CAPE WILL BE MAINLY EAST OF A LINE FROM LARNED TO ASHLAND. SEVERE
WEATHER IS NOT EXPECTED. LOWS ON TUESDAY MORNING LOOK TO BE IN THE
UPPER 30S WEST TO NEAR 50 EAST FA. HIGHS ON TUESDAY WILL RANGE FROM
NEAR 50 IN THE FAR WEST TO THE LOW TO MID 60S FAR EAST FA.
ON WEDNESDAY THE UPPER LOW CONTINUES TO MOVE NORTHEAST AND INTO
EASTERN KANSAS AND OKLAHOMA. LOWS IN MORNING WILL BE IN THE UPPER
30S FAR WEST TO THE MID AND UPPER 40S EAST. HIGH TEMPERATURES WILL
RANGE FROM THE MID 60S WEST TO AROUND 60 NORTHEAST. RAIN CHANCES
DIMINISH FROM WEST TO EAST WITH THE UPPER LOW. TOTAL RAINFALL
COULD RANGE FROM ONE QUARTER TO OVER ONE HALF INCH WITH THE
HIGHEST IN THE SOUTHEASTERN FA FROM LARNED TO ASHLAND.
FOR THURSDAY THE UPPER LEVEL SHORTWAVE RIDGING WILL MOVE INTO THE
PLAINS WITH A WARM UP BACK INTO THE 70S.
ANOTHER UPPER LEVEL SHORTWAVE TROUGH WILL MOVE RAPIDLY NORTHEASTWARD
ACROSS THE NORTHERN AND CENTRAL PLAINS FOR FRIDAY PUSHING ANOTHER
COLD FRONT ACROSS KANSAS ON SATURDAY AS IT MOVES INTO THE NORTHERN
HIGH PLAINS. LITTLE IF ANY RAINFALL IS EXPECTED. HIGHS ON FRIDAY
LOOK TO BE IN THE MID TO UPPER 70S WITH SLIGHTLY COOLER TEMPS ON
SATURDAY TO AROUND 70. OVERNIGHT LOWS WILL BE IN THE 40S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1201 AM CDT SUN APR 1 2012
TWO CONCERNS FOR THE 06Z TAFS. FOG AND WINDS. THE 01/02Z HRRR IS
MOST AGGRESSIVE IN BRINGING DENSE FOG ACROSS SOUTH CENTRAL KANSAS BY
MORNING. THIS MODEL WAS FAIRLY ACCURATE LAST NIGHT ALTHOUGH A LITTLE
TOO LOW ON VIS. THE RUC ALSO SHOWS LOWERED VIS GENERALLY IN THE SAME
AREA. DON`T HAVE ENOUGH CONFIDENCE FOR LIFR CIGS BUT HAVE LOWERED CIGS
FROM VFR TO MVFR TO START OUT ON THE CONSERVATIVE SIDE SINCE THE HRRR
OVERDID IT LAST NIGHT. SECOND CONCERN IS WINDS. HAVE INCREASED SW WINDS
20-25 KT WITH GUSTS TO 30-35 KT AS THE LEE SFC TROUGH STRENGTHENS TOMORROW
AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 52 74 43 57 / 0 10 50 50
GCK 49 69 41 55 / 0 10 50 50
EHA 50 66 37 50 / 0 20 50 40
LBL 49 71 40 55 / 0 20 50 50
HYS 52 72 44 59 / 0 10 40 50
P28 57 82 49 63 / 0 30 50 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON CDT /11 AM MDT/ TODAY TO 9 PM CDT /8
PM MDT/ THIS EVENING FOR KSZ030-043>045-061>064-074>078-084>087.
&&
$$
UPDATE...RUTHI
SYNOPSIS...RUTHI
SHORT TERM...RUTHI
LONG TERM....KRUSE
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS WICHITA KS
1135 PM CDT SAT MAR 31 2012
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MAIN CONCERN REMAINS POTENTIAL FOR LOW STRATUS.
LEE TROUGH WILL ALLOW LIGHT SOUTH-SOUTHEASTERLY WINDS TO CONTINUE
OVERNIGHT WITH INCREASING BOUNDARY LAYER MOISTURE. THIS SHOULD
RESULT IN LIFR-IFR STRATUS DEVELOPMENT OVER MUCH OF THE AREA DURING
THE EARLY AM HOURS SUNDAY. THIS IS SUPPORTED IN THE NAM...GFS...RUC...AND
3KM HRRR MODELS. FORECAST CONFIDENCE IS ABOVE AVERAGE GIVEN THE
LOW STRATUS OCCURRENCE IN CENTRAL/SOUTHWEST OK AND NORTH CENTRAL
TEXAS SATURDAY MORNING. THE STRATUS LOOKS TO BURN OFF TOWARD MIDDAY
SUNDAY. BETTER MIXING AND NEAR FULL SUNSHINE SUNDAY AFTERNOON
SHOULD RESULT IN SOUTHERLY GUSTS ~25 KT MOST OF THE AREA.
JMC
&&
PREV DISCUSSION... /ISSUED 243 PM CDT SAT MAR 31 2012/
DISCUSSION...
FORECAST CHALLENGES...LOW CLOUD TRENDS TONIGHT/SUNDAY MORNING AND
THEN PRECIP CHANCES/TRENDS EARLY NEXT WEEK.
TONIGHT-MONDAY
LITTLE CHANGE TO THE FORECAST TO CLOSE OUT THE WEEKEND...WITH
THE UNSEASONABLE WARMTH CLOSING IN ON SOME RECORDS. FOR THIS
EVENING...SOUTHEAST KANSAS WILL REMAIN ON EDGE OF WEAKER CAP
WHERE MODERATE INSTABILITY WILL BE PRESENT PRIOR TO DARK. HOWEVER
LACK OF FOCUS/TRIGGER SHOULD PRECLUDE CONVECTION SO WILL KEEP
FORECAST DRY. SOME PATCHY LIGHT FOG WITH PERHAPS BETTER CHANCE FOR
SOME LOW CLOUDS TO DEVELOP AROUND DAWN ACROSS SOUTHERN PORTIONS OF
THE AREA WITH CLOUDS LINGERING INTO MIDDAY FOR AREAS EAST OF THE
TURNPIKE. OTHERWISE...INCREASING SOUTHERLY FLOW/BETTER MIXING INTO
SUNDAY AFTERNOON SHOULD RESULT IN MORE SUNSHINE...WIND AND VERY
WARM MAXS ACROSS THE ENTIRE...GENERALLY IN THE 85 TO 90F RANGE.
THE APPROACHING UPPER TROF WILL MOVE ACROSS THE SOUTHWEST CONUS
SUNDAY NIGHT...BECOMING A CLOSED LOW AS IT MOVES ACROSS THE
SOUTHERN ROCKIES DURING MONDAY. THE INHERITED FORECAST SUPPORTS
THE LATEST MODEL CONSENSUS IN SLOWING THE SURFACE FRONTAL PASSAGE
AND PRECIP/CONVECTIVE CHANCES TO LATER IN THE DAY ON MONDAY. THIS
WILL RESULT IN ONE MORE DAY OF UNSEASONABLY WARM TEMPERATURES
ESPECIALLY FOR LOCATIONS ALONG AND EAST OF THE TURNPIKE.
TUESDAY-WEDNESDAY
A LITTLE BETTER MODEL CONTINUITY EXISTS WITH THE MOVEMENT OF
THE CLOSED UPPER LOW ACROSS MID-AMERICA INTO MID-WEEK...WITH
BEST CHANCE FOR SHOWERS/STORMS ON TUESDAY AND WEDNESDAY.
THURSDAY-SATURDAY
A COUPLE DAYS OF DRY WEATHER EXPECTED IN THE WAKE OF THE
DEPARTING UPPER LOW FOR THURSDAY AND FRIDAY. MEANWHILE UPPER
TROUGHING WILL DEVELOP ACROSS THE WESTERN CONUS WITH A
SIGNIFICANT SHORTWAVE LIFTING NORTHEAST ACROSS THE NORTHERN
PLAINS BY SATURDAY. WHILE CONFIDENCE IS MODEST AT BEST...WILL
SHOW SMALL PRECIP/CONVECTIVE CHANCES ALONG THE ASSOCIATED
SURFACE FRONT FRIDAY NIGHT/SATURDAY.
DARMOFAL
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
FAIRLY QUIET AVIATION FORECAST FOR MOST OF THE PERIOD. FEW-SCT
DIURNAL CUMULUS THIS AFTERNOON AT KICT-KHUT-KCNU WILL BURN OFF BY
00-02Z. OTHERWISE...DIURNAL COOLING IN CONCERT WITH INCREASING
BOUNDARY LAYER MOISTURE MAY PROMOTE A 3-5 HOUR PERIOD OF IFR/LIFR
CIGS FROM 10/11Z THROUGH 14/15Z. THE NAM MODEL MAY BE
OVER-MOISTENING THE BOUNDARY LAYER AS IT OFTEN DOES...HENCE
CONFIDENCE IS LOW ON THIS OCCURRING...SO ONLY HINTED AT IT IN THE
18Z TAFS.
ADK
FIRE WEATHER...
DESPITE UNSEASONBALY WARM TEMPERATURES AND INCREASING WINDS ON
SUNDAY...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 60 87 61 84 / 0 0 0 20
HUTCHINSON 59 89 59 81 / 0 0 0 20
NEWTON 60 87 62 82 / 0 0 0 20
ELDORADO 60 87 63 85 / 0 0 0 20
WINFIELD-KWLD 61 88 63 86 / 0 0 0 20
RUSSELL 59 91 56 75 / 0 0 0 20
GREAT BEND 58 90 55 77 / 0 0 0 20
SALINA 61 90 60 81 / 0 0 0 20
MCPHERSON 60 89 60 81 / 0 0 0 20
COFFEYVILLE 62 88 66 88 / 0 10 10 10
CHANUTE 61 88 65 87 / 0 10 10 10
IOLA 61 88 65 87 / 0 10 10 10
PARSONS-KPPF 61 88 65 88 / 0 10 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DULUTH MN
342 AM CDT SUN APR 1 2012
LARGE AREA OF LOW CLOUDS/FOG HAS PERSISTED ACROSS MOST OF CWA
OVERNIGHT AS APPROACHING FRNTL SYSTEM HAS STALLED/WEAKENED
UNDERNEATH BUILDING MID LVL RIDGE. RUC13 SHOWS WINDS NORTH OF
FRNTL BDRY AT 925 HAVE ALREADY SWITCHED TO NE INDICATING NOT MUCH
PUSH TO GET THE BDRY THROUGH ANYTIME SOON. MSAS HAS PRESS RISES
WEAKENING NORTH OF BDRY AS WELL. SFC T/TD SPREADS ARE NEAR ZERO
OVER MOST OF NRN CWA WHERE MSTR HAS POOLED AHEAD OF DECAYING
FRONT. LOCALLY DENSE FOG AT THIS TIME ACROSS NRN ITASCA/KOOCH/NRN
STL COUNTIES. WILL ISSUE DFA FOR EARLY MORNING.
TODAY..WIDESPREAD CLOUDS/FOG SHOULD GRADUALLY DIMINISH BY MIDDAY
AS MID LVL RIDGE AXIS SHIFTS EAST TOWARDS LAKE SUPERIOR. BDRY LYR
FLOW WILL INCREASE FROM SOUTHEAST DURING AFTN AND CEILINGS SHOULD
LIFT. CLOUD FCST WILL BE CHALLENGING TODAY BUT HAVE LEANED WITH
WRF ARW 4KM IDEA THAT CLEARING WILL ADVECT FROM MPX CWA BY LATE
MORNING. HAVE USED A BIAS CORRECTED BLEND OF THE EC/ALLBLEND TO
FCST MAX TEMPS. THIS ALSO RESPECTS THE BRISK ONSHORE COMPONENT THAT
DEVELOPS THIS AFTN AS MESOSCALE WEDGE OF HIGH PRESSURE NOSES DOWN
LAKE FROM ONTARIO.
TONIGHT...CYCLOGENESIS OVER WRN HI PLAINS CREATES STRENGTHENING
WARM ADVECTION PATTERN ACROSS NRN PLAINS. LLJ IS FCST TO PUSH INTO
CWA WITH ELEVATED CONVECTION DEVELOPING AFTER 6Z. USING SREF CPTP
AND EC/NAM CONVECTIVE FCSTS OF SHEAR/MUCAPE PUTS INCREASING
LIKELIHOOD OF THUNDER INTO SWRN CWA MIDNIGHT...THEN ACROSS
MOST OF CWA EXCEPT ERN ARROWHEAD BY 12Z. SREF 3HR CALIBRATED SVR
VALUES QUITE LOW AT THIS TIME.
TOMORROW...SFC LOW WILL TRACK INTO SWRN MN BY 0Z TUES. MAIN PUSH
OF 85H MSTR TRANSPORT WILL BE FOCUSED ACROSS NRN TIER OF CWA WHERE
LOCALLY HEAVY PRECIP IS POSSIBLE. EC/GEM/NAM IN MDT AGREEMENT THAT
STRONG LOW LVL INVERTED TROUGH WILL BE AIDED BY APPROACHING UPPER
TROF. MID LVL WARM ADVECTION MAY LIMIT MUCH PRECIP DEVELOPMENT OVER
WISC ZONES..AND PERHAPS AS FAR NORTH AND WEST AS TWIN PORTS. LATER
SHIFTS MAY NEED TO LOWER POPS EVEN FARTHER IN THIS AREA.
.EXTENDED...MONDAY NIGHT THROUGH SATURDAY...
AN UPPER LEVEL TROF WILL MOVE INTO THE FA MONDAY NIGHT PUSHING A SFC
FRONT INTO NORTH CENTRAL WI BY 12Z TUESDAY. SHOWERS AND
THUNDERSTORMS WILL OCCUR AHEAD OF THE TROF AND NEAR THE FRONT. THE
TROF REACHES NE WI BY 00Z WEDNESDAY AND PUSHES THE FRONT WELL E OF
THE AREA AND ENDS THE PCPN. TUESDAY NIGHT THROUGH FRIDAY WILL BE
DOMINATED BY HIGH PRESSURE OVER THE GREAT LAKES. BY FRIDAY
NIGHT...RETURN FLOW SETS UP AS THE SFC HIGH SLIPS FARTHER TO THE E.
A STRONG LLJ AT 850MB WILL USHER IN WARM/MOIST AIR. ENOUGH
DESTABILIZATION OCCURS TO MENTION SOME POPS OVER THE WESTERN TWO
THIRDS OF THE FA. POPS ARE SPREAD OVER THE ENTIRE FA ON SATURDAY AS
A CLOSED/STACKED UPPER LOW MEANDERS THROUGH THE NORTHERN
PLAINS...SENDING PIECES OF ENERGY TOWARD THE FA.
.AVIATION...06Z TAFS
IFR OR LOW MVFR CEILINGS COVERED MOST OF THE NORTHLAND...WITH
CLEAR SKIES FROM WALKER TO COOK TO CRANE LAKE AND POINTS NORTH AND
WEST. SATELLITE DID SHOW THE STRATUS WAS MOVING BACK TOWARD THE
WEST AND NORTH TOWARD WALKER. FOG WAS ALSO DEVELOPING...AND VSBYS
SHOULD CONTINUE TO DROP OVERNIGHT. LOW LEVEL WINDS WILL BE VEERING
TO EASTERLY LATE TONIGHT INTO SUNDAY...AND DENSE FOG MAY DEVELOP
AROUND LAKE SUPERIOR AS AN ONSHORE FLOW DEVELOPS.
NAM BUFR SOUNDINGS CONTINUE TO SHOW THE CEILINGS LIFTING QUICKLY
ON SUNDAY...BUT WE HAVE LOW CONFIDENCE IN THAT OCCURRING GIVEN THE
EASTERLY LOW LEVEL FLOW.
MOISTURE/WARM AIR ADVECTION WILL BE INCREASING SUNDAY NIGHT...WITH
THE STABILITY DROPPING. THE MODELS DO SHOW SHOWERS/STORMS
DEVELOPING OVER PARTS OF THE NORTHLAND BY LATE EVENING. SOME OF
THE STORMS COULD BE QUITE STRONG.
.POINT TEMPS/POPS...
DLH 55 41 54 38 / 10 30 40 50
INL 63 40 53 33 / 10 50 60 40
BRD 67 50 64 38 / 10 40 50 40
HYR 67 45 64 39 / 10 30 30 50
ASX 58 43 58 38 / 10 30 30 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR MNZ010>012-
018-019-021-025-026.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...CANNON
LONG TERM....GSF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1201 AM CDT SUN APR 1 2012
.UPDATE...
UPDATED FOR THE 06Z AVIATION DISCUSSION BELOW.
&&
.DISCUSSION...
CONSIDERABLE CLOUDINESS CONTINUES TO PLAGUE MUCH OF THE FA AT MID
AFTERNOON. ONLY THE FAR WESTERN COUNTIES HAVE NEAR FULL SUN. SOME
THINNING APPEARS TO BE OCCURRING OVER WEST CENTRAL WI. THE HRRR IS
TRYING TO SHOW CLEARING WORKING INTO FAR EASTERN MN AND WEST
CENTRAL WI BY THIS EVENING. HOWEVER...CLEARING OR NOT...THE
PRESSURE GRADIENT WILL WEAKEN TONIGHT WITH SATURATION DEVELOPING
DURING THE OVERNIGHT HOURS. THIS WILL LIKELY TO LEAD FOG AND MORE
STRATUS REFORMING. NAM BUFKIT HYDROLAPSE SHOWS A NICE INCREASE
JUST ABOUT EVERYWHERE TONIGHT DURING THE LATE NIGHT HOURS.
INDICATED AREAS OF FOG IN THE FORECAST...BUT DENSE FOG IS NOT OUT
OF THE QUESTION SUNDAY MORNING.
IN ADDITION...A WEAK SHORT WAVE IS PASSING BY EARLY THIS EVENING.
SEVERAL MODEL SOLUTIONS STILL TRY TO DEVELOP SOME SHOWERS OVER
CENTRAL MN AND PASS THEM ACROSS THE TWIN CITIES AND WEST CENTRAL
WI. CONFIDENCE IS NOT HIGH AND HAVE KEPT THE FORECAST DRY BUT THE
DIFFERENTIAL HEATING OCCURRING TO OUR WEST NOW IS A CONCERN. MUCH BETTER
INSTABILITY IS DEVELOPING OVER WESTERN IA ATTM AND THE LOW LEVEL
MOISTURE TRANSPORT INCREASES EARLY THIS EVENING BETWEEN KDSM AND
KMKE. SO SOME STORMS ARE POSSIBLE JUST TO OUR SOUTH OF OUR FA THIS
EVENING.
SUNDAY WILL BE THE WARMEST DAY OF THE NEXT SEVEN FOR MANY AREAS. MUCH
WILL DEPEND ON THE AMOUNT OF STRATUS AND FOG IN THE MORNING...BUT
WEST CENTRAL THROUGH SOUTH CENTRAL MN HAVE A REALLY GOOD CHANCE
OF SEEING HIGHS REACH WELL INTO THE 80S. READINGS IN THE 80S ARE
OCCURRING RIGHT NOW TO THE WEST AND SOUTH OF KFSD WITH H85
TEMPERATURES OF +16 TO +18 DEGREES C. SOUTHWEST AREAS OF MN WILL
BE SOME 2 TO 3 DEGREES C ABOVE THIS SUNDAY AFTERNOON. A HIGH NEAR
90 IS NOT OUT OF THE QUESTION AROUND LUVERNE AND PIPESTONE.
A LOW PRESSURE SYSTEM AND ASSOCIATED FRONTAL BOUNDARIES WILL MOVE
INTO THE FA SUNDAY NIGHT. ELEVATED INSTABILITY DEVELOPS BY EVENING
NORTH OF THE WARM FRONT ACROSS CENTRAL MN AND PUSHES INTO
NORTHWEST WI DURING THE NIGHT. LOW LEVEL MOISTURE TRANSPORT
INCREASES DRAMATICALLY ACROSS EAST CENTRAL MN AS THE LOW LEVEL
JET INCREASE TO 40 KNOTS. LAPSE RATES ARE BETTER THAN 6.5 DEG C/KM
ALONG WITH A FAVORABLE DIFFERENTIAL TEMPERATURE ADVECTION PATTERN.
THE CROSSOVER BETWEEN 850 AND 500 MB IS RATHER IMPRESSIVE BUT A
LITTLE NORTH OF OUR CWA. ALL OF THIS POINTS TO SOME STORMS
DEVELOPING ACROSS CENTRAL MN AND MOVING TOWARDS KDLH. A FEW STORMS
WITH LARGE HAIL MAY OCCUR.
THERE STILL REMAINS MODEL SPREAD FROM MONDAY THROUGH TUESDAY ON
MOVING THE LOW AND TRAILING COLD FRONT ACROSS THE FA. THE ECMWF
REMAINS THE SLOWEST WHILE THE NAM IS THE FASTEST. THE GEM AND GEFS
ARE PRETTY SIMILAR. TRIED TIMING PRECIPITATION BASED ON THIS
COMBINATION. THIS YIELDED LIKELY POPS OVER EAST CENTRAL MN MONDAY
AFTERNOON AND ACROSS PARTS OF WEST CENTRAL WI MONDAY EVENING. HIGH
TEMPERATURES ON MONDAY MAY BE WARMER THAN FORECAST FOR SOUTHEAST
AREAS OF THE FA IF THE CLOUDINESS/SHOWERS/THUNDERSTORMS DO NOT
DEVELOP AS FORECAST.
DRY WEATHER FORECAST IN THE WAKE OF THE FRONT FOR TUESDAY THROUGH
FRIDAY AS HIGH PRESSURE STALLS OVER THE WESTERN GREAT LAKES. HIGHS
DURING THE PERIOD FROM 55 TO 65 WITH LOWS FROM 35 TO 45. A PACIFIC
COLD FRONT IS THEN PROJECTED ACROSS THE REGION FOR NEXT SATURDAY.
HOWEVER...THE ECMWF REMAINS THE SLOWEST ON MOVING THE FRONT
THROUGH ALONG WITH WEAKENING THE SYSTEM AS IT APPROACHES. FOR
NOW...INDICATED ONLY A SMALL CHANCE FOR RAIN SHOWERS.
&&
.AVIATION.../06Z TAF ISSUANCE/
DIFFICULT CEILING FCST THRU THE NEXT 24 HRS DUE TO THE SLOW
PROGRESSION OF THE SFC FRONTS OVER WRN MN/ERN DAKOTAS COMBINED
WITH THICK ENOUGH LOW CLOUDS PREVENTING MIXING. FOG SATELLITE
PRODUCE SHOWS LARGE SWATH OF LOW STRATUS WITH FOG ENCOMPASSING THE
AREA. WITH ONE TAF SITE...KAXN...ALREADY WELL INTO THE LIFR
CATEGORY...SEE NO REASNO WHY THE OTHERS WOULD NOT GET THERE...ESP
THOSE THAT WOULD BE E AND N OF THE SFC BOUNDARIES. WILL LOOK FOR
ALL TAF SITES TO GET DOWN TO A VARIATION OF IFR-OR-WORSE...WHETHER
FROM CIG OR VSBY...THROUGH DAYBREAK. ONCE PAST THE DEGRADED FLIGHT
CONDS THROUGH DAYBREAK...QUESTION BECOMES HOW LONG WILL THE IFR-
TO-MVFR CIGS LAST THROUGH THE AFTN. MODELS SUGGEST DELAYED
PROGRESSION OF THE WMFNT OUT WEST...WHICH WOULD KEEP LOW LEVEL
EAST-TO-SOUTHEAST WINDS IN PLACE THRU THE DAY AND HENCE THE LOW
MOISTURE WHICH WOULD NOT MIX OUT WELL AND KEEP LOW STRATUS GOING.
HAVE ADVERTISED THIS TREND FOR ALL BUT KAXN AND KRWF...WHICH
WOULD BE MOST LIKELY TO CLEAR OUT. HIGH CIRRUS WOULD THEN PREVAIL
THRU THE EVENING UNTIL HIGH CLOUDS LOWER AND THICKEN TMRW NIGHT.
MSP...CIGS MAINTAINING AT LOWER-END MVFR AND WILL LOOK FOR THEM TO
TOUCH INTO IFR BEFORE SLOWLY RISING OUT DURG THE DAY TMRW.
HOWEVER...THAT RISE WILL BE SLOW SO WILL MAINTAIN MVFR CIGS
THROUGH THE DAY. DIFFICULT TO TELL IF THE CIGS WILL BE ABOVE OR
BELOW THE 1700 FT THRESHOLD BUT GIVEN THAT THE CHANGE HAS BEEN
MADE TO DELAY CLEARING WITH THIS ISSUANCE...HAVE COMPROMISED AND
KEPT THE LATE MRNG THRU AFTN CIGS AT 2000 FT. CLOUDS SCATTER OUT
LATE DAY THEN HIGH CLOUDS FILL IN.
OUTLOOK...
/SUN NIGHT-MON NIGHT/...FRONTAL SYSTEM MOVING THRU WILL PRODUCE
SHWRS AND TSTMS ACRS THE REGION. MVFR-IFR CONDS LIKELY.
/TUE-THU/...VFR UNDER HIGH PRESSURE.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
144 AM EDT SUN APR 1 2012
.SYNOPSIS...
ISOLATED SHOWERS AND THUNDERSTORMS WILL LINGER OVER THE AREA AS A
COLD FRONT MOVES SOUTH ACROSS THE AREA EARLY THIS MORNING...WITH
DRY WEATHER SETTLING IN TODAY AND TONIGHT. A DRY COLD FRONT WILL
DROP QUICKLY SOUTHEAST OVER THE AREA MONDAY. UNSETTLED CONDITIONS
WILL RETURN BY MID WEEK...AS A LOW PRESSURE SYSTEM APPROACHES THE
EASTERN CAROLINAS.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1030 PM SATURDAY...LATEST SFC ANALYSIS PLACES THE COLD FRONT
PARTIALLY INTO NC...DROPPING FROM THE NORTH. THE CONVECTION ACROSS
THE NE PORTION OF THE STATE IS BASICALLY ALONG THE COLD FRONT
ITSELF. THE OUTFLOW FROM THIS CONVECTION IS AIDING THE COLD FRONTS
PUSH SOUTHWARD...AND COULD REACH THE NORTHERN PORTIONS OF THE ILM
CWA BY MIDNIGHT THROUGH 1 AM SUNDAY. SLIGHTLY FASTER THAN 1ST
PROGGED WITH HRRR AND AN EARLIER NAM MODEL RUN. HRRR INDICATES 1
MORE POTENTIAL MINI ROUND OF CONVECTION TO PUSH THROUGH IMMEDIATELY
AHEAD OF THE COLD FRONT. WILL CONTINUE WITH LOW CHANCE POPS THROUGH
ROUGHLY 2 AM SUNDAY. LOOKING AT NAM 1K-8H PARTIAL THICKNESS PACKING
AND HRRR HRLY WINDS...THE COLD FRONT WILL DROP NEARLY DUE SOUTH
ACROSS THE FA BETWEEN 1AM AND 7AM SUNDAY. LOOK FOR NW WINDS TO VEER
TO THE N-NE ALONG WITH A MINI CAA SURGE THAT WILL ONLY LAST THRU
MIDDAY SUNDAY B4 SHUTTING OFF. WITH THREAT OF PCPN INTO THE EARLY AM
HRS OF SUNDAY AND CLOUDS STICKING AROUND FOR MUCH OF THE REMAINDER
OF THE NIGHT. HAVE KEPT FOG DEVELOPMENT AT A MINIMUM WITH AN
INCREASED POTENTIAL FOR A BRIEF STRATUS DECK UP THRU 1-2 HRS AFTER
DAYBREAK. HAVE KEPT OVERNIGHT LOWS STABLE AFTER INCREASING A DEGREE
OR 3 EARLIER...ESPECIALLY THE SOUTHERNMOST LOCALES WHERE THE FROPA
WILL COINCIDE WITH DAYBREAK.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 300 PM SATURDAY...COLD FRONT POSITIONED JUST OFFSHORE AT THE
START OF THE PERIOD. NVA AND SOME DRY AIR ADVECTION THROUGH THE MID
LEVELS OF THE COLUMN KEEP SUNDAY SUNNY...BUT TEMPS WILL WARM WELL
INTO THE 70S WITH LACK OF ANY CAA AND ENHANCED RIDGING ALOFT. TEMPS
REMAIN WELL ABOVE CLIMO SUNDAY NIGHT AS GRADIENT TIGHTENS BETWEEN
RIDGE OF HIGH PRESSURE AND ADVANCING COLD FRONT FROM THE NORTH. THIS
COMBINED WITH SOME INCREASING MID-LEVEL CLOUDINESS WILL KEEPS MINS
IN THE MID/UPPER 50S.
SHORTWAVE TROUGH ROTATING DOWN FROM NEW ENGLAND SPAWNS A SURFACE LOW
IN THE MID ATLANTIC WHICH TRIES TO DRIVE A COLD FRONT THROUGH EARLY
MONDAY. WITH N/NW FLOW ALOFT...ANTICIPATE THIS FRONT TO WORK ALL THE
WAY SOUTH THROUGH THE CWA BY AFTN. DURING FROPA...MID LEVEL LAPSE
RATES STEEPEN AND FORECAST SOUNDINGS DEPICT INCREASING SATURATION IN
THE 800-500MB LAYER. FORCING IS NOT STRONG...BUT WILL ADD A SCHC POP
FOR TSTMS MONDAY...DECREASING FROM NORTH TO SOUTH THROUGH THE AFTN.
THIS FRONT WILL MAKE FOR A DIFFICULT TEMP FORECAST MONDAY AS
WELL...WITH 850MB TEMPS POSSIBLY FALLING THROUGH PEAK
HEATING...ESPECIALLY ACROSS NE ZONES. EXPECT TEMPS TO RANGE FROM THE
UPPER 80S IN THE TYPICAL WARM PEE DEE LOCATIONS...TO AROUND 80 IN
THE NORTHEAST ZONES...EVEN WITH FAVORED DOWNSLOPE COMPRESSIONAL
WARMING OCCURRING.
FRONT STALLS SOUTH OF THE AREA AND SOME ISENTROPIC LIFT BEGINS LATE
MONDAY NIGHT...ESPECIALLY ACROSS THE SOUTHERN PORTIONS OF THE CWA.
WILL RAMP POP BACK UP TO SCHC ACROSS THE SOUTH. MINS WILL FALL TO
AROUND 50 ACROSS THE NORTHEAST CWA...TO NEAR 60 IN THE SOUTH.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 300 PM SATURDAY...AMPLITUDE WILL ONCE AGAIN BE
THE NAME OF THE GAME FOR THE EXTENDED AS A LARGE MID LEVEL CYCLONE
WILL BE WOBBLING OVER THE FOUR CORNERS REGION INITIALLY WITH RIDGING
JUST WEST OF OUR REGION. AT THE SURFACE A FRONT WILL RESIDE JUST TO
THE SOUTHWEST BEFORE GETTING WASHED OUT WEDNESDAY. A BACKDOOR FRONT
WILL MOVE ACROSS THURSDAY INCREASING THE WEAK FORCING MECHANISMS IN
PLACE...THIS AS THE MID LEVEL PATTERN AMPLIFIES SLIGHTLY. FINALLY
LATE THURSDAY AND FRIDAY THE MAIN SYSTEM ASSOCIATED WITH THE
PREVIOUSLY MENTIONED MID LEVEL LOW MOVES ACROSS. BOTTOM LINE...I
HAVE INCREASED POPS FROM TUESDAY THROUGH THURSDAY INCREMENTALLY
BASED ON A DIURNAL SCENARIO. THE NEW DAY...SATURDAY LOOKS DRY AT
THIS POINT BUT THE INHERIT DIFFICULTIES OF FORECASTING A CLOSED
SYSTEM THIS FAR OUT IN TIME MAKE FOR A LOW CONFIDENCE DRY
FORECAST.
REGARDING TEMPERATURES...HAVE INCREASED TEMPERATURES A BIT ACROSS
THE BOARD TO MATCH GUIDANCE AND ADJACENT OFFICES BUT OVERALL TRENDS
OF SLIGHTLY ABOVE EARLY TREND TO NEAR NORMAL LATE REMAIN INTACT.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...CONVECTION ASSOCIATED WITH COLD FRONT WILL DROP INTO THE
NORTHERN TERMINALS SHORTLY AFTER TAF ISSUANCE. THE CONVECTION WILL
BE WANING WITH MVFR/IFR CONDITIONS INTO DAYBREAK BEHIND THE FRONT.
WINDS WILL SHIFT TO THE NORTHEAST...WITH MODERATE CONFIDENCE FOR AN
IFR/NEAR MVFR CEILING. SOME MVFR VISIBILITIES ARE POSSIBLE BUT LESS
LIKELY. THE STRATUS SHOULD MIX OUT AROUND 14Z...BUT TAKE A BIT
LONGER WITH THE NORTHEAST WIND SURGE. WINDS WILL VEER TO EAST
NORTHEAST...THEN SOUTHEAST ALONG THE COAST IN THE AFTERNOON WITH
THE RESULTANT WIND FROM A WEAK TO MODERATE SEA BREEZE.
EXTENDED OUTLOOK...LOW CONFIDENCE SHOWERS/ISOLATED THUNDERSTORM
MONDAY AND TUESDAY. SCATTERED CONVECTION POSSIBLE WEDNESDAY WITH A
BETTER CHANCE FOR PRECIP ON THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM SATURDAY...LATEST OBSERVATIONS OVER THE ILM NC WATERS
INDICATE SEAS STILL RUNNING WITHIN SCA THRESHOLDS ACROSS THE OUTER
WATERS OFF CAPE FEAR. THE SCA WILL REMAIN THRU MIDNIGHT WHICH IS
AMPLE TIME FOR THESE SEAS TO SUBSIDE BELOW SCA THRESHOLDS. GUIDANCE
CONTINUES TO FURTHER SUBSIDE SEAS DURING THE PRE-DAWN HRS OF SUNDAY
AS A COLD FRONT DROPS SOUTH ACROSS THE ILM WATERS BETWEEN 1 AM AND 7
AM SUNDAY. WINDS WILL VEER TO THE N-NE AFTER FROPA AND AID IN
KNOCKING DOWN THE BUILT UP SHORT PERIOD SW WIND DRIVEN SEAS FROM THE
PAST 1-2 DAYS. COULD SEE THE LAST ROUND OF CONVECTION MOVE OFF THE
MAINLAND THROUGH 2 AM SUNDAY. OTHERWISE...LOOK FOR A N-NE MINI SHORT
LIVED COLD SURGE BEHIND THE COLD FRONT...LASTING THROUGH MID TO LATE
SUNDAY MORNING.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 PM SATURDAY...COLD FRONT WILL BE POSITIONED OFFSHORE AT
THE START OF THE PERIOD WITH N/NE WINDS ONGOING ACROSS THE WATERS.
RIDGE OF HIGH PRESSURE BUILDS IN FROM THE SOUTH DURING THE AFTN AND
WINDS BECOME LIGHT...VEERING TO THE SW THROUGH THE EVE AS A
PRE FRONTAL AIRMASS MOVES OVER THE AREA AND INCREASING RAPIDLY TO
15-20 KTS SUN NIGHT AS A COLD FRONT APPROACHES FROM THE WEST. COLD
FRONT DROPS SOUTH DURING MONDAY...AND WINDS WILL GRADUALLY VEER FROM
SW TO N...THEN NE MONDAY NIGHT...ALL AT SPEEDS OF AROUND 10 KTS.
LACK OF ANY MEANINGFUL SWELL WITHIN THE WAVE SPECTRUM MEANS THAT
SEAS WILL BE PRIMARILY WIND DRIVEN...2-3 FT THROUGH THE
PERIOD...WITH A COMBINATION OF NE AND SW CHOP SUNDAY...BECOMING
DOMINATED BY NE WAVE ON MONDAY.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 300 PM SATURDAY...MAIN EVENT FOR THE MARINE
COMMUNITY WILL BE THE BACK DOOR FRONT MOVING ACROSS THURSDAY. THIS
FRONT WILL EVENTUALLY BRING ALL WINDS AROUND TO NORTHEAST BUT FOR
MOST OF THE DAY THURSDAY THE NORTH CAROLINA AND SOUTH CAROLINA
WATERS WILL BE DIVIDED BY THE FRONT. FOR EARLIER IN THE
PERIOD...EASTERLY WINDS INITIALLY WITH A SOUTH TO SOUTHWESTERLY FLOW
DEVELOPING LATER TUESDAY AND PREVAILING THROUGH WEDNESDAY. SEAS ARE
GENERALLY 2-4 FEET WITH WINDS WAVES DOMINATING THE SPECTRUM.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH/COLBY
SHORT TERM...JDW
LONG TERM...SHK
AVIATION...HDL/COLBY
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
350 AM CDT SUN APR 1 2012
.DISCUSSION...THE DENSE FOG IS BECOMING MORE WIDESPREAD AND
ADVECTING TO THE NORTH AND WEST ACCORDING TO WEB CAMS AND
OBSERVATIONS. THE HRRR IS DOING AN EXCELLENT JOB WITH THIS
FOG...AND WILL FOLLOW FOR THE FORECAST. ISSUED A DENSE FOG
ADVISORY FOR AREAS ALONG AND SOUTH OF A VALLEY CITY TO GRAND FORKS
TO BAUDETTE LINE. RADAR SHOWS SHOWERS NEAR THE INTERNATIONAL
BORDER...AND THESE WILL BE NORTH OF THE DENSE FOG AREA. FAIRLY
CONFIDENT THAT THE DENSE FOG WILL BE ABLE TO ADVECT INTO THE
VALLEY CITY...FARGO...AND GRAND FORKS AREAS.
&&
.AVIATION...LIFR/IFR CIGS/VSBY WILL CONTINUE TO ADVECT NORTHEAST
FROM WEST CENTRAL MINNESOTA INTO THE EARLY MORNING HOURS. THE MAIN
QUESTION WILL BE HOW FAR TO THE NORTH/WEST THESE CONDITIONS WILL
ADVECT. CURRENT HI-RES MODEL GUIDANCE SUGGESTS THAT A SURE BET
WILL BE KBJI AND KFAR...WHILE KGFK AND KTVF WILL BE ON THE
EDGE...AND KDVL SHOULD REMAIN VFR. MOST GUIDANCE SUGGESTS ALL
SITES VFR BY 18Z. GUSTY SOUTHEAST WINDS EXPECTED TO DEVELOP BY
AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 310 AM CDT SUN APR 1 2012/
SHORT TERM (SUN-TUE)...INTERESTING FORECAST WITH MULTIPLE
CHALLENGES. MODEL DIFFERENCES ARISE ON MONDAY WITH TIMING OF
FRONT. GEM/ECMWF SLOW WHILE NAM/GFS QUICKER. ECMWF HAS BEEN
CONSISTENT WITH THE SLOW SOLUTION...BUT HAD BEEN AN OUTLIER UNTIL
THIS SET OF MODEL RUNS WITH THE GEM TRENDING SLOWER. WILL HAVE TO
FOLLOW A BLEND.
UPPER RIDGE BUILDING INTO THE REGION FOR TODAY. AHEAD OF THIS
UPPER RIDGING...SCATTERED SHOWERS ASSOCIATED WITH WEAK WAVE (WARM
AIR ADVECTION) POSSIBLE DURING THE EARLY MORNING HOURS...EXITING
THE NE FA BY NOON. LOW-LEVEL FLOW IS INCREASING FROM THE
SOUTHEAST...AND ADVECTING LOW LEVEL MOISTURE (LOW CLOUDS/FOG) BACK
INTO THE REGION FROM CENTRAL MINNESOTA. FOLLOWING HRRR...EXPECT
THESE CIGS TO ADVECT INTO ALL BUT THE FAR NORTHERN FA BY
12Z...THEN SCATTER WITH DAYTIME HEATING AND STRONG SE WINDS BY
MID TO LATE MORNING. DENSE FOG POSSIBLE UNTIL MID-MORNING...AND
WILL MONITOR CONDITIONS FOR POSSIBLE ADVISORY. SO FAR DENSE FOG
IS NOT TOO WIDESPREAD...BUT HRRR SUGGESTS THAT DENSE FOG WILL
BECOME WIDESPREAD BY 05Z. WINDS WILL BE CLOSE TO ADVISORY CRITERIA
THIS AFTERNOON...BUT PARAMETERS SUGGEST JUST BELOW. WITH SOLAR AND
GOOD MIXING...EXPECT FULL HEATING POTENTIAL...WITH MAX TEMPS
AROUND 80F ACROSS THE SW FA TO UPPER 60S ACROSS THE NE FA.
EXPECTED TEMP VALUES ALONG AND WEST OF THE VALLEY WILL BE RECORD
HIGHS.
UPPER RIDGING WILL BE BRIEF WITH UPPER FLOW BECOMING SOUTHWEST
TONIGHT. STRONG 850MB JET WILL DEVELOP AND TRANSPORT MOISTURE
ALONG AND AHEAD COLD FRONT. FOLLOWING MODEL COMPROMISE FOR
TIMING...BEST PRECIP CHANCES WILL BE ALONG AND EAST OF THE
VALLEY...FROM 06Z MON INTO THE AFTERNOON HOURS. 850MB CAPE
1000-1500 J/KG INTO THE EARLY MORNING ALONG WITH STRONG LOW-LEVEL
JET ACROSS SE FA COULD LEAD TO ISOLD SEVERE HAIL (SPC HAS A 5%
PROBABILITY)...ALTHOUGH DEEP LAYER SHEAR WILL BE MARGINAL. UPPER
TROUGH SWINGS THROUGH BY MON NIGHT. AS THIS FEATURE APPROACHES
CANNOT RULE OUT SHOWERS ANYWHERE ON MONDAY...BUT HEAVIEST RAINFALL
SHOULD BE IN MINNESOTA COUNTIES (AHEAD OF COLD FRONT WHERE PWATS
ARE HIGHEST). CLOUDS AND COOLER AIRMASS WILL LEAD TO MUCH COLDER
TEMPS ON MONDAY (ALTHOUGH STILL ABOVE NORMAL).
RIDGING MOVES BACK INTO THE REGION ON TUESDAY...AND TEMPS BEGIN TO
TREND WARMER AGAIN.
LONG TERM (WED-SAT)...RIDGING DOMINATES INTO FRIDAY BEFORE MOVING
TO THE EAST ALLOWING SW FLOW ALOFT. DRY AND WARM CONDITIONS SHOULD
TRANSITION TO COOLER AND WETTER BY SATURDAY IF MODELS HAVE TIMING
CORRECT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR NDZ027-029-
030-038-039-049-052-053.
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ001>003-
006-008-009-013>017-022>024-027>032-040.
&&
$$
TG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
349 AM CDT SUN APR 1 2012
.SHORT TERM...TODAY THROUGH MONDAY...
RECORD WARMTH AND CRITICAL FIRE WEATHER WILL HIGHLIGHT THE SHORT
TERM FORECAST FOR TODAY...FOLLOWED BY COOLER...BUT STILL ABOVE
NORMAL TEMPERATURES FOR MONDAY WITH MARGINAL FIRE WEATHER CONCERNS.
FOR THIS MORNING ADDED A PATCHY FOG MENTION TO THE JAMES RIVER
VALLEY AS STRATUS AND FOG CONTINUE TO EXPAND EAST AS PROGGED BY
THE LATEST HRRR MODEL RUNS OVERNIGHT. OTHERWISE...AS OF 08
UTC...BROAD SURFACE LOW PRESSURE WAS ANALYZED ACROSS MUCH OF
CENTRAL AND EASTERN MONTANA...WITH TWO DISTINCT CIRCULATIONS
ACROSS FAR SOUTHEAST MONTANA AND SOUTHEAST ALBERTA...WITH A COLD
FRONT ACROSS CENTRAL MONTANA AND A WARM FRONT FROM NEAR HAVRE
MONTANA THROUGH FAR SOUTHEAST SOUTH DAKOTA. THE OVERALL
PROPAGATION OF THE SYSTEM HAS SLOWED...WITH THE COLD FRONT
FORECAST TO REACH THE NORTH DAKOTA BORDER CLOSER TO 18 UTC...WITH
THE SURFACE WARM FRONT AT THAT TIME EXTENDING FROM APPROXIMATELY
CROSBY THROUGH LINTON. NEAR TO RECORD BREAKING HIGH TEMPERATURES
ARE FORECAST IN THE WARM SECTOR OF THE SURFACE LOW ACROSS MUCH OF
WESTERN AND CENTRAL NORTH DAKOTA ENHANCED BY COMPRESSIONAL HEATING
AND MIXING JUST AHEAD OF THE COLD FRONT. SHOWN BELOW ARE FORECAST
HIGHS AND RECORDS FOR TODAY FOR SELECT LOCATIONS ACROSS THE AREA.
SITE FORECAST RECORD YEAR
DICKINSON 76 74 1964
MINOT 78 72 1928
BISMARCK 82 75 1976
JAMESTOWN 78 78 1907
WILLISTON 70 72 1991
OVERALL THE DETERMINISTIC AND STATISTICAL GUIDANCE SUITE LOW LEVEL
THERMAL FIELDS ARE IN GOOD AGREEMENT...AND CHOSE TO GO A COUPLE OF
DEGREES ABOVE THE CONSENSUS GIVEN THE EFFECTS OF BROWN VEGETATION
ENHANCING MIXING HEIGHTS.
THE AFOREMENTIONED COLD FRONT IS EXPECTED TO PROPAGATE AS FAR EAST
AS NORTH DAKOTA HIGHWAY 3 BY LATE AFTERNOON. THE WIND FIELD BEHIND
THE COLD FRONT IS FORECAST TO BE SLIGHTLY WEAKER COMPARED TO
PREVIOUS FORECASTS...WITH THE 01/00 UTC NAM/GFS BUFR SOUNDINGS
INDICATING A WEAK INVERSION NEAR 800-750 MB...WHICH WILL LIMIT
MIXING HEIGHTS. THAT SAID...POST FRONTAL WINDS SUSTAINED TO NEAR
20 KTS WITH GUSTS OF 25-30KTS ARE EXPECTED WITH MINIMUM RH VALUES
OF 15 TO 25 PERCENT WITH POST FRONTAL TEMPERATURES STILL IN THE
60S AND 70S. WHEN COMBINED WITH THE ABUNDANCE OF DRY FUELS AND
LACK OF GREEN UP....VERY HIGH FIRE DANGER IS FORECAST ACROSS MUCH
OF THE AREA...WITH EXTREME FIRE DANGER ACROSS THE FAR SOUTHWEST.
THE CURRENT RED FLAG WARNING LOOKS GOOD...EXCEPT FOR THE FAR
EASTERN TIER OF COUNTIES WHICH MAY NOT SEE FRONTAL PASSAGE UNTIL
THE EARLY EVENING...AND THUS NOT MEET CRITERIA. HOWEVER...IT WILL
BE CLOSE AND WILL LEAVE THE WARNING AS IS FOR NOW.
FOR TONIGHT...STRONG ISALLOBARIC FORCING VIA AN 8-10 MB/6 HR
PRESSURE RISE BUBBLE IS FORECAST ACROSS MUCH OF WESTERN AND CENTRAL
NORTH DAKOTA BEHIND THE COLD FRONT. THE QUESTION WILL BE HOW WELL
THE BOUNDARY LAYER WILL BE ABLE TO STAY MIXED AFTER SUNSET. AT THIS
TIME THE BEST POTENTIAL LOOKS TO BE ACROSS THE SOUTHWEST AND SOUTH
CENTRAL...WHERE LITTLE CHANGE IN WIND MAGNITUDE IS POSSIBLE EVEN
AFTER SUNSET...WHICH IS OF CONCERN FOR ANY ONGOING FIRES THAT MAY
START TODAY. GIVEN THE EXPECTED MIXING CWA WIDE...FOLLOWED A
CONSENSUS OF 01/00 UTC NAM/GFS FOR OVERNIGHT LOWS...WHICH YIELDS
WIDESPREAD 40S FOR NEARLY ALL OF THE CWA...WITH LOWS POSSIBLY AS
WARM AS 50 ACROSS THE SOUTH CENTRAL.
MONDAY LOOKS TO BE COOLER...WITH HIGHS IN THE 50S WITH GOOD
AFTERNOON MIXING CWA WIDE. HOWEVER...TEMPERATURES ARE STILL FORECAST
TO BE 5 TO 10 DEGREES ABOVE NORMAL. DESPITE THE COOLER
TEMPERATURES...MARGINAL FIRE WEATHER CONCERNS ARE POSSIBLE ACROSS
THE FAR SOUTHWEST WHERE WIND GUSTS IN EXCESS OF 25 KTS MAY BE
POSSIBLE...WITH RH VALUES OF 20-25 PERCENT. GIVEN THE MARGINAL
NATURE OF THE THREAT AND TO AVOID CONFUSION WITH THE CURRENT FIRE
WEATHER HEADLINES...WILL LET THE DAY SHIFT EVALUATE FURTHER.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...
THE MEDIUM RANGE MODELS ARE CONSISTENT WITH RESPECT TO THE SYNOPTIC
PATTERN OVER THE NORTHERN PLAINS THROUGH THURSDAY. MODEL SOLUTIONS
BEGIN TO DIVERGE WITH RESPECT TO THE UPPER PATTERN FRIDAY AND
SATURDAY. AS A RESULT...USED A BLEND OF SOLUTIONS FOR THE END OF
THE WEEK.
A REX BLOCK/HIGH OVER LOW PATTERN WILL TRAVERSE ACROSS THE GREAT
PLAINS TUESDAY THROUGH THURSDAY. THIS WILL GENERATE DRY CONDITIONS
AND A GRADUAL WARMING TREND ACROSS NORTH DAKOTA THROUGH MID-WEEK
WITH HIGHS GENERALLY IN THE UPPER 60S TO LOWER 70S BY THURSDAY.
MODEL SOLUTIONS BEGIN TO DIVERGE WITH RESPECT TO A POSSIBLE LATE
SEASON WINTER STORM EXPECTED TO IMPACT THE REGION THURSDAY NIGHT
THROUGH SATURDAY. THE MAIN QUESTIONS ARE WHEN EXACTLY THIS SYSTEM
WILL BEGIN TO IMPACT WESTERN AND CENTRAL NORTH DAKOTA AND WHAT THE
PRECIPITATION TYPE WILL BE.
AS IS TYPICAL WITH HIGH IMPACT WEATHER SYSTEMS...THE ECMWF IS THE
SLOWEST SOLUTION RELATIVE TO THE GFS/GEM. IT PAINTS QPF ACROSS
WESTERN NORTH DAKOTA ALONG A STRONG BAROCLINIC ZONE FRIDAY AFTERNOON
WHEREAS THE GFS/GEM IS ABOUT 12-18 HOURS FASTER BEGINNING PRECIP
WEST THURSDAY NIGHT. WOULD LIKE TO SIDE WITH THE ECMWF GIVEN ITS
SUPERIOR PERFORMANCE IN THE EXTENDED. HOWEVER...THE HIGH UNCERTAINTY
WARRANTS A BROAD BRUSHING OF POPS FOR THE THURSDAY NIGHT THROUGH
SATURDAY PERIOD WITH THE HIGHEST POPS WEST.
AS THIS SYSTEM MOVES ACROSS THE STATE...ITS SURFACE REFLECTION IS
PROGGED TO GENERATE VERY WINDY CONDITIONS ACROSS WESTERN AND CENTRAL
NORTH DAKOTA DURING THE FRIDAY NIGHT/SATURDAY PERIOD. IN
ADDITION...WRAP-AROUND MOISTURE COMBINED WITH 850MB TEMPERATURES
FALLING BELOW ZERO SHOULD ALLOW FOR A WINTRY MIX OF PRECIPITATION TO
DEVELOP FRIDAY NIGHT WITH PRIMARILY SNOW EXPECTED NORTHWEST BY
SATURDAY. THE COMBINATION OF HIGH WINDS AND WINTRY PRECIPITATION
COULD MAKE FOR AN INTERESTING WEEKEND. STAY TUNED.
&&
.AVIATION...
PRIMARILY VFR CONDITIONS ARE EXPECTED ACROSS WESTERN AND
CENTRAL NORTH DAKOTA THROUGH THE TAF PERIOD. LIGHT SHOWERS WILL
CONTINUE TO IMPACT KMOT THROUGH THE MORNING HOURS.
EXPECT E/SE WINDS THIS MORNING AHEAD OF A STRONG FRONT THAT WILL
SWEEP THROUGH NORTH DAKOTA TODAY. WINDS WILL BECOME W/NW BEHIND THE
FRONT AND GUST AROUND 30 KTS IN THE AFTERNOON AT ALL SITES EXCEPT
FOR KJMS.
&&
.FIRE WEATHER...
A COLD FRONT IS FORECAST TO ENTER FAR WESTERN NORTH DAKOTA NEAR
MID DAY TODAY...AND PUSH AS FAR EAST AS NORTH DAKOTA HIGHWAY 3 BY
LATE AFTERNOON. WIDESPREAD NEAR TO RECORDING BREAKING HIGH
TEMPERATURES INTO THE MID TO UPPER 70S...TO PERHAPS THE LOWER 80S
ARE FORECAST AHEAD OF THE COLD FRONT. BEHIND THE FRONT...GOOD
MIXING SHOULD ALLOW FOR SUSTAINED WESTERLY WINDS TO 25 MPH WITH
GUSTS APPROACHING 35 MPH...AS RH VALUES FALL TO 15 TO 25 PERCENT
WITH TEMPERATURES STILL IN THE 60S AND 70S. THE FAR EASTERN TIER
OF COUNTIES IN THE RED FLAG WARNING MAY NOT SEE FRONTAL PASSAGE
UNTIL THE EARLY EVENING...AND THUS NOT MEET CRITERIA. HOWEVER...IT
WILL BE CLOSE AND WILL LEAVE THE WARNING AS IS FOR NOW. FOR
TONIGHT...STRONG WINDS MAY CONTINUE THROUGH MUCH OF THE
OVERNIGHT...ESPECIALLY ACROSS THE SOUTHWEST AND SOUTH
CENTRAL...WITH NORTHWEST WINDS OF SIMILIAR SPEEDS AS SEEN PRIOR TO
SUNSET LASTING THROUGH THE NIGHT.
MONDAY LOOKS TO BE COOLER AND BREEZY BEHIND THE FRONT WITH HIGHS IN THE
50S AND RH VALUES FALLING TO 20 TO 30 PERCENT FOR MOST AREAS WITH
AFTERNOON MIXING. THE COOLER TEMPERATURES AND SLIGHTLY HIGHER RH
VALUES WILL HELP TO LIMIT THE OVERALL THREAT. THE AREA OF MOST
CONCERN FOR POSSIBLY REACHING CRITICAL VALUES IS THE FAR
SOUTHWEST...WHERE STRONGER NORTHWEST WINDS OF 20 TO 30 MPH ARE
POSSIBLE. HOWEVER...TO AVOID CONFUSION WITH THE CURRENT FIRE
WEATHER HEADLINES...WILL LET THE DAY SHIFT EVALUATE FURTHER.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON CDT /11 AM MDT/ TODAY TO 10 PM CDT /9
PM MDT/ THIS EVENING FOR NDZ009>012-017>023-031>036-040>047-050.
&&
$$
SHORT TERM/FIRE...AYD
LONG TERM/AVIATION....TM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
310 AM CDT SUN APR 1 2012
.SHORT TERM (SUN-TUE)...INTERESTING FORECAST WITH MULTIPLE
CHALLENGES. MODEL DIFFERENCES ARISE ON MONDAY WITH TIMING OF
FRONT. GEM/ECMWF SLOW WHILE NAM/GFS QUICKER. ECMWF HAS BEEN
CONSISTENT WITH THE SLOW SOLUTION...BUT HAD BEEN AN OUTLIER UNTIL
THIS SET OF MODEL RUNS WITH THE GEM TRENDING SLOWER. WILL HAVE TO
FOLLOW A BLEND.
UPPER RIDGE BUILDING INTO THE REGION FOR TODAY. AHEAD OF THIS
UPPER RIDGING...SCATTERED SHOWERS ASSOCIATED WITH WEAK WAVE (WARM
AIR ADVECTION) POSSIBLE DURING THE EARLY MORNING HOURS...EXITING
THE NE FA BY NOON. LOW-LEVEL FLOW IS INCREASING FROM THE
SOUTHEAST...AND ADVECTING LOW LEVEL MOISTURE (LOW CLOUDS/FOG) BACK
INTO THE REGION FROM CENTRAL MINNESOTA. FOLLOWING HRRR...EXPECT
THESE CIGS TO ADVECT INTO ALL BUT THE FAR NORTHERN FA BY
12Z...THEN SCATTER WITH DAYTIME HEATING AND STRONG SE WINDS BY
MID TO LATE MORNING. DENSE FOG POSSIBLE UNTIL MID-MORNING...AND
WILL MONITOR CONDITIONS FOR POSSIBLE ADVISORY. SO FAR DENSE FOG
IS NOT TOO WIDESPREAD...BUT HRRR SUGGESTS THAT DENSE FOG WILL
BECOME WIDESPREAD BY 05Z. WINDS WILL BE CLOSE TO ADVISORY CRITERIA
THIS AFTERNOON...BUT PARAMETERS SUGGEST JUST BELOW. WITH SOLAR AND
GOOD MIXING...EXPECT FULL HEATING POTENTIAL...WITH MAX TEMPS
AROUND 80F ACROSS THE SW FA TO UPPER 60S ACROSS THE NE FA.
EXPECTED TEMP VALUES ALONG AND WEST OF THE VALLEY WILL BE RECORD
HIGHS.
UPPER RIDGING WILL BE BRIEF WITH UPPER FLOW BECOMING SOUTHWEST
TONIGHT. STRONG 850MB JET WILL DEVELOP AND TRANSPORT MOISTURE
ALONG AND AHEAD COLD FRONT. FOLLOWING MODEL COMPROMISE FOR
TIMING...BEST PRECIP CHANCES WILL BE ALONG AND EAST OF THE
VALLEY...FROM 06Z MON INTO THE AFTERNOON HOURS. 850MB CAPE
1000-1500 J/KG INTO THE EARLY MORNING ALONG WITH STRONG LOW-LEVEL
JET ACROSS SE FA COULD LEAD TO ISOLD SEVERE HAIL (SPC HAS A 5%
PROBABILITY)...ALTHOUGH DEEP LAYER SHEAR WILL BE MARGINAL. UPPER
TROUGH SWINGS THROUGH BY MON NIGHT. AS THIS FEATURE APPROACHES
CANNOT RULE OUT SHOWERS ANYWHERE ON MONDAY...BUT HEAVIEST RAINFALL
SHOULD BE IN MINNESOTA COUNTIES (AHEAD OF COLD FRONT WHERE PWATS
ARE HIGHEST). CLOUDS AND COOLER AIRMASS WILL LEAD TO MUCH COLDER
TEMPS ON MONDAY (ALTHOUGH STILL ABOVE NORMAL).
RIDGING MOVES BACK INTO THE REGION ON TUESDAY...AND TEMPS BEGIN TO
TREND WARMER AGAIN.
.LONG TERM (WED-SAT)...RIDGING DOMINATES INTO FRIDAY BEFORE MOVING
TO THE EAST ALLOWING SW FLOW ALOFT. DRY AND WARM CONDITIONS SHOULD
TRANSITION TO COOLER AND WETTER BY SATURDAY IF MODELS HAVE TIMING
CORRECT.
&&
.AVIATION...LIFR/IFR CIGS/VSBY WILL CONTINUE TO ADVECT NORTHEAST
FROM WEST CENTRAL MINNESOTA INTO THE EARLY MORNING HOURS. THE MAIN
QUESTION WILL BE HOW FAR TO THE NORTH/WEST THESE CONDITIONS WILL
ADVECT. CURRENT HI-RES MODEL GUIDANCE SUGGESTS THAT A SURE BET
WILL BE KBJI AND KFAR...WHILE KGFK AND KTVF WILL BE ON THE
EDGE...AND KDVL SHOULD REMAIN VFR. MOST GUIDANCE SUGGESTS ALL
SITES VFR BY 18Z. GUSTY SOUTHEAST WINDS EXPECTED TO DEVELOP BY
AFTERNOON.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
TG
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1149 PM CDT SAT MAR 31 2012
.DISCUSSION...
LOOKS LIKE VFR CONDITIONS WILL CONTINUE FOR THE NEXT 24 HOURS. SEE
THE BELOW AVIATION SECTION.
&&
.AVIATION...
LATEST MODELS DID NOT INDICATE ANY NEED FOR CHANGES TO THE CURRENT
TERMINALS. GUSTY SOUTHWEST SURFACE WINDS TOMORROW AFTERNOON
STILL LOOK LIKELY.
HUBER
&&
.PREV DISCUSSION... /ISSUED 635 PM CDT SAT MAR 31 2012/
DISCUSSION...
EXPECT VFR CONDITIONS TO CONTINUE ACROSS WEST CENTRAL TEXAS FOR
THE NEXT 24 HOURS. AVIATION BELOW HAS ADDITIONAL INFORMATION.
AVIATION...
MODELS CONTINUE TO HOLD A SURFACE TROUGH OF LOW PRESSURE...AND AN
ASSOCIATED SURFACE DRYLINE...IN THE TEXAS AND NEW MEXICO AREA FOR
THE NEXT 24 HOURS. THE LATEST RUC INDICATES THE SURFACE PRESSURE
GRADIENT WILL INCREASE ACROSS WEST CENTRAL TEXAS OVERNIGHT
TONIGHT. THUS...LOOK FOR GUSTY SOUTHWEST SURFACE WINDS TO DOMINATE
WEST CENTRAL TEXAS BY 06Z TONIGHT. FOR TOMORROW AFTERNOON...WATCH
FOR STRONGER SOUTHWEST SURFACE WINDS AS THE SURFACE PRESSURE GRADIENT
STRENGTHENS ACROSS WEST CENTRAL TEXAS.
HUBER
PREV DISCUSSION... /ISSUED 334 PM CDT SAT MAR 31 2012/
SHORT TERM...
AN UPPER LEVEL RIDGE WILL AMPLIFY THROUGH TOMORROW AS IT BUILDS EAST
OF THE FORECAST AREA AHEAD OF AN APPROACHING UPPER LEVEL TROUGH...
WHICH WILL BE OVER THE SOUTHERN ROCKIES BY LATE TOMORROW. HOT AND
DRY WEATHER WILL CONTINUE ACROSS WEST CENTRAL TEXAS TOMORROW WITH
LOW TO UPPER 90S OVER THE CWA...THE WARMEST TEMPERATURES SHOULD BE
OVER THE NORTHERN HALF OF THE CWA AS THE 850MB THERMAL RIDGE LIFTS
FURTHER TO THE NORTH.
15
LONG TERM...
THE DEEP CLOSED LOW OFF THE PACNW COAST WILL BE A PLAYER IN OUR
WEATHER AS THE LONG TERM OPENS BUT THE MEDIUM RANGE MODELS
CONTINUE TO STRUGGLE WITH THE TIMING. THE LATEST RUNS SUGGEST THAT
THIS FEATURE WILL SLOW AS IT MOVES ACROSS THE SOUTHWEST
CONUS...LIFTING NORTHEAST ACROSS THE TX PANHANDLE AFTER 00Z
WEDNESDAY. THIS LATER ARRIVAL WILL LIKELY RESULT IN THE DRYLINE
SETTING UP FARTHER WEST THAN PREVIOUS ANTICIPATED GIVEN WEAKER
FORCING. STRONG SYNOPTIC LIFT /DEPICTED BY H5-H3 Q VECTOR
CONVERGENCE/ IS PROGGED TO REMAIN WEST OF THE CWA UNTIL MONDAY
NIGHT BY WHICH TIME THE DRYLINE WILL BE RETREATING. THUNDERSTORMS
WILL BE POSSIBLE ALONG AND EAST OF THE DRYLINE LATE MONDAY
AFTERNOON. SURFACE TEMPS IN THE MID/UPPER 80S AND DEWPOINTS WILL
RESULT IN SIGNIFICANT INSTABILITY /SBCAPES OF 1500-3000/ BUT A
SLOWER ARRIVAL OF SYNOPTIC ASCENT MAY RESULT IN THE CAP HOLDING
STRONG AND LIMITING THE CONVECTIVE POTENTIAL /ESPECIALLY IN THE
EAST IN THE AREA OF STRONGEST INSTABILITY/...MUCH OF THE CHAGRIN
OF THE SOUTHERN PLAINS CHASE COMMUNITY. I OPTED TO MAINTAIN THE
INHERITED POPS ON THE CENTRAL AND EAST ON MONDAY AFTERNOON BUT
EXPANDED THEM WEST MONDAY NIGHT AND TUESDAY TO ACCOUNT FOR THE
SLOWER TIMING.
COOLER TEMPS ARE EXPECTED ON TUESDAY AS A PACIFIC COLD FRONT MOVES
THROUGH THE AREA. I LOWERED MAX TEMPS INTO THE MID/UPPER 70S BUT
FEEL I MAY STILL BE A FEW DEGREES ON THE WARM SIDE BASED ON H85
TEMPS. I AM NOT SOLD ON THE AGGRESSIVE RETURN OF SOUTHERLY FLOW
SHOWN BY THE GFS AND LEANED MORE HEAVILY ON THE ECMWF SOLUTION IN
THE POST FRONTAL ENVIRONMENT. WITH THAT SAID...I KEPT MAX TEMPS
GENERALLY AT OR JUST BELOW 80 DEGREES ON WEDNESDAY BUT DRY
CONDITIONS WILL RESULT IN A VERY PLEASANT DAY. MIN TEMPS TUESDAY
NIGHT ARE EXPECTED TO BE IN THE MID/UPPER 50S...WARMING SLIGHTLY
/LOWER 50S/ BY WEDNESDAY NIGHT. BY THURSDAY...THE H85 THERMAL RIDGE
WILL BUILD BACK OVER THE AREA WITH INCREASING SOUTHERLY WINDS. TEMPS
ARE EXPECTED TO WARM BACK INTO THE MID 80S. THESE SOUTHERLY WINDS
WILL BRING THE LOW LEVEL MOISTURE BACK THURSDAY NIGHT AND FRIDAY.
THE MODELS ARE HINTING AT SOME CONVECTION DEVELOPING OVER WEST TX
FRIDAY EVENING ALONG THE DRYLINE BUT MY GUT SAYS THAT MOISTURE
RETURN WILL NOT BE ADEQUATE TO SUPPORT MORE THAN FEW HIGH BASED
STORMS. THUS...NO POPS WERE INCLUDED AT THIS TIME.
HOWEVER...CONSIDERABLE UNCERTAINTY EXISTS AT THIS TIME. TEMPS WILL
AGAIN BE WARM ON FRIDAY WITH HIGHS IN THE MID/UPPER 80S.
THE GFS/DGEX DEPICT A WEAK COLD FRONT STALLING OVER THE AREA BY NEXT
WEEKEND...ENHANCING RAIN CHANCES. HOWEVER...THE ECMWF KEEPS THIS
BOUNDARY NORTH OF THE CWA IN CONJUNCTION WITH THE UPPER LEVEL
SYSTEM. THE ECMWF ALSO PUSHES H5 HEIGHTS UP NEAR 585DM WITH THE MID
LEVEL ANTICYCLONE CENTERED OVER DEEP SOUTH TX WHEREAS THE GFS KEEPS
HEIGHTS AROUND 580DM WITH THE RIDGE CENTERED OVER THE GULF OF
MEXICO. I WILL LET THE MODELS CONTINUE TO TEASE US OVER THE NEXT FEW
DAYS BEFORE JUMPING ON ANY PARTICULAR SOLUTION.
JOHNSON
FIRE WEATHER...
ELEVATED FIRE WEATHER CONDITIONS CAN BE EXPECTED SUNDAY OVER THE BIG
COUNTRY...CONCHO VALLEY AND THE NORTHERN EDWARDS PLATEAU WITH
UNSEASONABLY HOT TEMPERATURES IN THE 90S CONTINUING...ACCOMPANIED BY
LOW RELATIVE HUMIDITY VALUES...AND SOUTHWEST WINDS BETWEEN 15 AND 20
MPH. CRITICAL FIRE WEATHER CONDITIONS ARE POSSIBLE MAINLY WEST OF A
LINE FROM HASKELL TO STERLING CITY SUNDAY AFTERNOON WITH 20 FOOT
SOUTHWEST WINDS APPROACHING 20 MPH AND RELATIVE HUMIDITY VALUES
DROPPING TO LESS THAN 10 PERCENT.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 65 96 65 85 52 / 0 0 0 20 30
SAN ANGELO 60 96 62 86 51 / 0 0 0 20 20
JUNCTION 62 93 64 87 51 / 10 10 10 20 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
HUBER
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
205 AM EDT SUN APR 1 2012
.SYNOPSIS...
WEAK HIGH PRESSURE WILL CONTINUE TO BUILD INTO OUR AREA TONIGHT.
THIS HIGH WILL MOVE SOUTHEAST OF OUR AREA ON SUNDAY. ANOTHER
APPROACHING COLD FRONT WILL ENTER OUR AREA BY MONDAY MORNING.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 945 PM EDT SATURDAY...
PERSISTENT CLUSTER OF SCATTERED THUNDERSTORMS FROM GRAYSON COUNTY
INTO WILKES COUNTY WAS GRADUALLY DRIFTING EAST. AREAS RADAR
CONTINUES TO SHOW ISOLATED SHOWERS AND THUNDERSTORMS ON THE
EASTERN AND SOUTHEAST FRINGE OF THE COUNTY WARNING AREA. LOCAL WRF
AND HRRR GUIDANCE HAD PRECIPITATION ENDING ACROSS THE FORECAST
AREA BY MIDNIGHT. ADJUSTED PROBABILITY OF PRECIPITATION IN THE
FORECAST FOR THIS TIMING. ALSO ADDED PATCHY FOG IN FOG THE
GREENBRIER RIVER VALLEY AND IN THE AREAS ACROSS THE SOUTHWEST
COUNTY WARNING AREA THAT HAD RAIN SATURDAY AFTERNOON AND EVENING.
DEW POINTS HAVE ALREADY DROPPED INTO THE UPPER 30S TO LOWER 40S
IN THE FAR NORTHERN COUNTY WARNING AREA. SURFACE DEW POINTS WILL
CONTINUE TO LOWER BEHIND THE FRONT ACROSS THE SOUTHERN COUNTIES OF
THE FORECAST AREA. HAD MADE SLIGHT ADJUSTMENTS TO OVERNIGHT LOWS
BASED ON 9PM OBS...CLOUD COVER AND THE LATEST LAMP GUIDANCE.
NAM AND LOCAL WRF HAD LAYER OF LOW CLOUDS SPREADING ACROSS CENTRAL
AND EASTERN VIRGINIA OVERNIGHT...AND REACHING AS FAR WEST AS
LYNCHBURG AND DANVILLE. HAVE ADDED MORE CLOUD COVER IN THE EAST
SINCE CEILINGS ARE ALREADY LOWERING JUST NORTH AND EAST OF THE
FORECAST AREA. THE CLOUDS IN THE EAST MAY TAKE MOST OF THE MORNING
TO MIX OUT. BUFKIT SOUNDINGS WERE SUGGESTING THAT CLOUDS MAY NOT
BECOME SCATTERED UNTIL AFTER 11AM.
AS OF 330 PM EDT SATURDAY...
SURFACE ANALYSIS INDICATES THAT THE COLD FRONT IS LOCATED ACROSS
OUR SOUTHERNMOST TIER OF COUNTIES THIS AFTERNOON...AND IS
CONTINUING TO MOVE SOUTHEAST. RADAR HAS INDICATED THAT SPOTTY
SHOWER ACTIVITY...AND A FEW THUNDERSTORMS...HAS DEVELOPED ACROSS
OUR AREA WITH AFTERNOON HEATING...BUT NONE OF THIS ACTIVITY IS
VERY STRONG. THAT STATED...CANNOT RULE OUT ONE OR TWO STRONG BUT
SHORT LIVED THUNDERSTORMS DEVELOPING DURING EARLY EVENING.
WEAK HIGH PRESSURE WILL CONTINUE TO BUILD INTO OUR AREA THIS
EVENING...WHICH WILL RESULT IN NORTHWESTERLY FLOW THROUGH THE
FIRST FEW HOURS OF SUNDAY MORNING. THIS DOWNSLOPE FLOW WILL ALLOW
CLOUD COVER TO DIMINISH ACROSS MUCH OF OUR AREA...ESPECIALLY AFTER
SUNSET WITH THE LOSS OF DAYTIME HEATING. HOWEVER...WEATHER FORECAST
MODELS HAVE INDICATED THE POSSIBILITY OF LOW CLOUDS REDEVELOPING
TONIGHT ALONG THE EAST FACING SLOPES IN SOUTHEAST WEST VIRGINIA
AND THE MOUNTAIN EMPIRE...AS RESIDUAL LOW LEVEL MOISTURE BECOMES
WEDGED ALONG THE RIDGELINES. WITH LIGHT WINDS ACROSS THE
AREA...WILL ALSO BE LOOKING AT THE POSSIBILITY OF PATCHY FOG
DEVELOPING ACROSS PORTIONS OF THE MOUNTAINS...ESPECIALLY IN THE
RIVER VALLEYS.
THE HIGH WILL SLIDE SOUTHEAST BY SUNRISE SUNDAY MORNING...AND WE
WILL BEGIN TO SEE SOUTHERLY WINDS TAKE OVER. WITH PLENTY OF DRY
AIR ALOFT...EXPECT THAT ANY FOG AND LOW CEILINGS WILL BURN OFF BY
10 AM...AND EXPECT MOSTLY CLEAR SKIES THROUGH EARLY AFTERNOON
AREAWIDE.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
AS OF 330 PM EDT SATURDAY...
ON SUNDAY NIGHT...THE NORTHEAST U.S. UPPER TROF DEEPENS IN RESPONSE
TO A SHORTWAVE MOVING SOUTHEAST. THIS WILL DRIVE A COLD FRONT
THROUGH THE FORECAST AREA AND SPARK A COMPLEX OF STORMS AS LOW LEVEL
THETA-E RIDGE INCREASES IN ADVANCE OF THE FRONT. BEST LOW LEVEL
CONVERGENCE WILL BE FOUND SE WV AND WEST OF I-77 WHERE HIGHEST POPS
WERE PLACED. INCREASED LOW TEMPERATURES A COUPLE OF DEGREES WITH A
FAIR AMOUNT OF CLOUDS AND MIXING.
AS WEAK HIGH PRESSURE TRIES TO WEDGE DOWN THE EASTERN U.S. A WEAK
LOW LEVEL CONVERGENCE ZONE IS ESTABLISHED IN THE FAR SOUTHWEST
PORTION OF THE FORECAST AREA. WITH THE GREATEST INSTABILITY EXPECTED
TO BE LOCATED HERE...WIDELY SCATTERED THUNDERSTORMS WILL BE
POSSIBLE. LEANED TOWARD THE COOLER NAM MOS GUIDANCE FOR HIGHS IN THE
EAST WITH A LOW LEVEL NORTHEAST FLOW IN PLACE.
FOR MONDAY NIGHT AND TUESDAY...AN UPPER LEVEL RIDGE TRIES TO BUILD
OVER THE REGION...BUT IS QUICKLY FLATTENED BY A NORTHERN STREAM
SYSTEM MOVES ACROSS SOUTHERN CANADA AND THE NORTHERN GREAT LAKES.
THE LOW LEVEL FLOW IN ADVANCE OF THIS SYSTEM COMES AROUND TO THE
SOUTH/SOUTHWEST USHERING IN HIGHER DEWPOINTS AND POTENTIALLY A DECK
OF LOW LEVEL STRATUS CLOUDS WITH GOOD MOISTURE ADVECTION. ISENTROPIC
LIFT ON THE LEADING EDGE OF THIS MAY BRING ANOTHER ROUND OF RAIN
THE FAR SOUTHWEST MONDAY NIGHT...WITH SHOWERS AND THUNDERSTORMS
DEVELOPING IN ADVANCE OF THE FRONT IN THE NORTHERN AND WESTERN
PORTION OF THE FORECAST AREA ON TUESDAY UNDER THE INSTABILITY AXIS.
TEMPERATURE FORECAST TUESDAY IS A TRICKY ONE AND HIGHS WILL DEPEND
ON THE AMOUNT OF CLOUD COVER SEEN. WITH THE POTENTIAL FOR LOW
CLOUDS TO ADVANCE INTO OUR AREA...DROPPED HIGHS A FEW DEGREES TOWARD
THE COOLER LOCALLY DERIVED MOS FORECAST HIGHS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 330 PM EDT SATURDAY...
FOR THE LONG TERM PORTION OF THE FORECAST...WE LEANED HEAVILY ON THE
00Z ECMWF SOLUTION WHICH SHOWS BETTER RUN TO RUN CONSISTENCY
COMPARED TO THE GFS WITH ITS HANDLING OF THE TIMING AND EVOLUTION OF
A CUT OFF LOW DRIFTING ACROSS THE SOUTHERN PLAINS...THEN THE
SOUTHEAST U.S. LATE IN THE PERIOD. THE ECMWF IS ALSO IN BETTER
AGREEMENT WITH THE CANADIAN AND UKMET SOLUTIONS. THE GFS ENSEMBLE
MEMBERS SHOW A WIDE RANGE OF POTENTIAL SOLUTIONS TO THE STRENGTH AND
LOCATION OF THIS UPPER LEVEL LOW WHICH GIVES US LOW CONFIDENCE IN
THE OPERATIONAL GFS SOLUTION.
SOME SIGNIFICANT MODIFICATIONS WERE MADE TO THE FORECAST BASED ON
THE ECMWF FORECAST. FIRST...WITH THE SLOWER TIMING...NOW EXPECT THE
COLD FRONT TO MOVE THROUGH LATE WEDNESDAY...ALLOWING TEMPERATURES TO
BE WELL ABOVE NORMAL WITH A DEEP WEST...DOWNSLOPING FLOW...WITH
THUNDERSTORMS POSSIBLE ALONG THE FRONT.
BEHIND THIS FRONT...TRENDED TEMPERATURES DOWN BY SEVERAL DEGREES
THUR-SATURDAY AS A LOW LEVEL NORTHEAST...THEN EAST...FLOW DEVELOPS
WITH THE UPPER LOW TO OUR SOUTH AND CANADIAN HIGH PRESSURE BUILDING
IN THE NE U.S.
WITH THE NAO FORECAST TO BECOME NEGATIVE AND THE GLOBAL WIND
OSCILLATION (GWO) IN A FAVORABLE PHASE FOR COOLER THAN NORMAL
CONDITIONS IN THE EASTERN U.S...THE COOLER ECMWF TEMPERATURES APPEAR
REASONABLE.
DEPENDING ON THE LOCATION OF THE UPPER LOW...SHOWERS/RAIN WILL BE
POSSIBLE EACH DAY...ESPECIALLY FOR THOSE FAVORED EASTERN UPSLOPE
AREAS AND TO THE SOUTH...CLOSER TO THE LOCATION OF THE UPPER LOW.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 200 AM EDT SUNDAY...
WEAK SURFACE HIGH PRESSURE BUILDING SOUTH OUT OF NEW ENGLAND
RESULTING IN NORTHEASTERLY MOIST FLOW FROM OFF ATLANTIC ALONG WITH
MVFR CEILINGS AT KLYH AND KDAN. UPSLOPING WESTERLY MOIST FLOW
ALSO RESULTING IN MVFR RESTRICTIONS AT KBLF. THESE CONDITIONS ARE
LIKELY TO PERSIST FOR THE REST OF THE NIGHT...BUT SHOULD GRADUALLY
MIX BACK OUT TO VFR WITH UNRESTRICTED CONDITIONS BY MID TO LATE
MORNING AS STRONG INSOLATION HELPS TO MIX UP/OUT INVERSION LAYER.
ELSEWHERE AT KROA AND KBCB...MAINLY VFR CONDITIONS SHOULD PREVAIL
THROUGH THE PERIOD. HOWEVER...SOME PATCHY FOG WITH LOCALIZED IFR TO
EVEN LIFR RESTRICTIONS IS POSSIBLE IN SOME OF THE MOUNTAIN
VALLEYS UNTIL SHORTLY AFTER DAYBREAK SUNDAY...AND THIS THREAT
CONTINUES TO BE REFLECTED IN CLIMATOLOGICALLY FAVORED LOCATIONS...
SUCH AS AT/NEAR KLWB.
APPROACH OF NEXT UPSTREAM WEATHER SYSTEM AND ASSOCIATED COOL
FRONT MAY BRING A THREAT FOR SCATTERED SHOWERS/THUNDERSTORMS
TONIGHT (SUNDAY NIGHT)...ALONG WITH POSSIBLE RESTRICTIONS BACK
INTO MVFR RANGE...ESPECIALLY IN THE MOUNTAINS.
THIS FRONT IS EXPECTED TO STALL OVER/ALONG THE MID APPALACHIANS
ON/BY MONDAY. ADDITIONAL WEAK SHORT WAVES AND MOISTURE STREAMING
NORTHEAST OVER THE STALLED FRONT...COMBINING WITH AN EASTERLY FLOW
FROM OFF THE ATLANTIC...MAY SET THE STAGE FOR ADDITIONAL MVFR
WEATHER...POTENTIALLY LOWER...INTO THE MID WEEK PERIOD...ESPECIALLY
OVER THE MOUNTAINS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/NF
NEAR TERM...AMS/NF
SHORT TERM...PH
LONG TERM...PH
AVIATION...WERT
AREA FORECAST DISCUSSION
NWS SEATTLE WA
930 PM PDT SAT MAR 31 2012
.SYNOPSIS...A LOW PRESSURE SYSTEM WILL MOVE THROUGH WESTERN
WASHINGTON THIS EVENING AND INLAND LATER TONIGHT. STRONG ONSHORE
FLOW WILL DEVELOP LATER TONIGHT AND PERSIST THROUGH SUNDAY MORNING.
A STRONG CONVERGENCE ZONE MAY GIVE HEAVY SNOW FOR THE CENTRAL
CASCADES SUNDAY MORNING. A WARM FRONT WILL REACH THE AREA SUNDAY
NIGHT. A STRONG WET FRONTAL SYSTEM COULD DIRECT HEAVY RAIN INTO THE
OLYMPIC MOUNTAINS MONDAY AND MONDAY NIGHT. THE SECOND HALF OF THE
WEEK WILL BE COOL WITH JUST SCATTERED SHOWERS.
&&
.SHORT TERM...AT 9PM LOW PRES EXTENDS ALONG THE WA AND NRN HALF OF
THE ORE COAST...THE LOW WILL SHIFT INLAND WITH STRONG ONSHORE FLOW
DEVELOPING OVERNIGHT. IT WILL BE BLUSTERY LATER TONIGHT THRU SUNDAY
MORNING...ALTHOUGH BECAUSE A PSCZ SETS UP OVER SEATTLE ON THE UW
WRFGFS I BELIEVE THE SSW WIND THROUGH THE PUGET SOUND BASIN SHOULD
NOT BE ALL THAT STRONG AS IT MIGHT IF THE GRADIENTS FROM THE RUC OR
NAM SLP FCSTS VERIFY. SHOWERS ARE INCREASING THIS EVENING...AND
THERE WILL BE AN ADDITIONAL BURST OF HEAVIER SHOWERS AT THE LEADING
EDGE OF THE STRONG ONSHORE FLOW...ESPECIALLY THROUGH THE STRAIT AND
OVER THE NW INTERIOR LATE TONIGHT AS DEPICTED IN THE UW MM5NAM...OR
OVER SW WA AND THEN THE CENTRAL CASCADES AS THE WRFGFS DEPICTS.
OVERALL THE BEST BET FOR HEAVY PRECIP WILL BE OVER THE CENTRAL
CASCADES FROM ABOUT 3AM TO 9AM WITH THE PSCZ...AND I THINK THE
SNOWFALL FORECAST FOR STEVENS AND SNOQUALMIE SHOULD PROBABLY BE
SOMETHING LIKE 6-12 INCHES SUNDAY MORNING SO WE MAY NEED A SNOW
ADVISORY FOR THE MAIN PASSES SUN MORNING. SHOWERS WILL LIKELY TAPER
OFF LATER SUN MORNING BEFORE INCREASING AGAIN LATE IN THE AFTERNOON
AND EVENING AS THE DISTURBANCE WHICH IS NEAR 137W AT 9PM REACHES WRN
WA...WITH PRETTY STRONG WLY FLOW IN THE MID LEVELS AND STRONG
JETSTREAM. THAT SYSTEM IS QUICKLY OVERTAKEN BY MOISTURE FROM THE
NEXT FRONTAL SYSTEM AND THE WARM ADVECTION MERGES WITH IT OVER WRN
WA SUN NITE. AFTER THAT THE STRONG WLY FLOW BUCKLES AND BACKS TO SSW
AS THE NEXT UPPER TROUGH ARRIVES JUST OFFSHORE. THIS SYSTEM WHICH
AFFECTS WRN WA ON MONDAY IS THE FRONTAL SYSTEM CURRENTLY OUT AT 155W
THIS EVENING WHICH DEVELOPS VERY RAPIDLY TONIGHT WITH A DEEP LOW
WHICH HAPPENS GO FROM A 998MB CENTER THIS EVENING IN THE GFS TO A
968MB CENTER APPROACHING THE CHARLOTTES BY 12Z MON. PRECIP AMOUNTS
IN THE MODELS VARY. THE GFS HAS THE HEAVY RAIN GOING INTO VANCOUVER
ISLAND...THE NAM ON THE OTHER HAND SHOWS 36HR PCPN OF 3-9 INCHES
OVER THE OLYMPICS WHICH WOULD GIVE RIVER FLOODING FOR PROBABLY THE
SATSOP AND SKOKOMISH. ALSO SEE HYDRO DISCUSSION BELOW. 19
.LONG TERM...A COOL UPPER LEVEL TROUGH WILL BE OVER THE PAC NW FOR
THE SECOND HALF OF THE WEEK. THAT WILL KEEP A CHANCE OF SHOWERS IN
THE FCST BUT IT WILL BE PARTLY SUNNY MOST DAYS...TEMPS WILL STAY
BELOW NORMAL. THIS WILL BE A GOOD PATTERN FOR SOME LATE SEASON
SKIING AND A VITAMIN D RECHARGE. 19
&&
.HYDROLOGY...A WET FRONTAL SYSTEM IS ON TAP FOR MON AND MONDAY
NIGHT...WITH HEAVY RAIN LIKELY FOR THE OLYMPICS. THE LATEST NAM
SHOWS THE CASCADES GET MUCH LESS RAIN THAN THE OLYMPICS AND RIVERS
FLOWING OUT OF THE CASCADES WOULD SEE PRETTY MODEST RISES...WITH WET
SNOW ABOVE ABOUT 4KFT IN THE CASCADES LIKELY. THE OLYMPICS ON THE
OTHER HAND REALLY GET HIT BY THE NAM WITH 3-9 INCHES OF RAIN IN
36HRS. THE 18Z GFS HAD A MAX OF 3-6.5 INCHES...BUT THE 00Z SOLUTION
PUTS ALL THE HEAVY RAIN OVER VANCOUVER ISLAND WITH JUST AN INCH OR
TWO FOR THE OLYMPICS. BEST BET NOW IS FLOODING POSSIBLE FOR A FEW
OLYMPIC RIVERS BUT NO SOLUTIONS SUGGEST PROBLEMS FOR CASCADE RIVERS.
19
&&
.AVIATION...SOUTHWESTERLY FLOW ALOFT BECOMING WESTERLY ON SUNDAY.
ELONGATED SURFACE LOW OVER WESTERN WASHINGTON WILL MOVE EAST
OVERNIGHT. AIR MASS UNSTABLE WITH A LARGE AREA OF SHOWERS ASSOCIATED
WITH THE LOW. CEILINGS LOWERING OVERNIGHT BACK DOWN TO THE 2000-3000
FOOT RANGE WITH THE INCREASING SHOWERS.
AS THE SURFACE LOW MOVES EAST OF THE CASCADES AND HIGH PRESSURE
BUILDS ALONG THE COAST STRONG ONSHORE FLOW WILL DEVELOP SUNDAY
MORNING. THIS WILL GENERALLY KEEP CEILINGS IN THE 2000-3000 FOOT
RANGE. A SHORTWAVE TROUGH MOVING QUICKLY IN THE JET STREAM SHOULD
ENHANCE SHOWERS OVER THE AREA AGAIN SUNDAY AFTERNOON KEEPING AT
LEAST AREAS OF CEILINGS IN THE 2000-3000 FOOT RANGE. SOME
IMPROVEMENT LATE SUNDAY AFTERNOON INTO SUNDAY EVENING ESPECIALLY
OVER THE CENTRAL PUGET SOUND WITH THE INCREASING WESTERLY FLOW
ALOFT.
KSEA...LIGHT WIND BECOMING SOUTHERLY 4 TO 8 KNOTS AFTER 09Z.
SOUTHERLY WINDS INCREASING QUICKLY AROUND 15Z TO THE 15 GUST 25 KNOT
RANGE. WINDS EASING IN THE AFTERNOON. CEILINGS BOUNCING AROUND WITH
THE SHOWER ACTIVITY WITH MVFR CEILINGS A MAJORITY OF THE TIME
ESPECIALLY AFTER 12Z. FELTON
&&
.MARINE...ELONGATED SURFACE LOW OVER THE INTERIOR OF WESTERN WESTERN
SHIFTING EAST OF THE CASCADES OVERNIGHT. STRONG SOUTHWEST ONSHORE
PUSH DEVELOPS SUNDAY MORNING...WITH GALES LIKELY FOR THE FIRST HALF
OF THE DAY FOR THE CENTRAL/EAST ENTRANCE AND HIGHER END SCA LEVEL
WINDS OVER OTHER WATERS. GRADIENTS WILL BRIEFLY EASE SUNDAY
AFTERNOON AS AN UPPER LEVEL DISTURBANCE SLIDING OVER SOUTHERN
WASHINGTON IN THE AFTERNOON HELPS TO DECREASE ONSHORE GRADIENTS.
A STRONG FRONTAL SYSTEM IS PEGGED TO REACH THE AREA ON MONDAY. 00Z
GFS MODEL STILL SHOWS WARM FRONT LIFTING OVER THE AREA SUNDAY
NIGHT...WITH INCREASINGLY S-SE WINDS OVER THE COAST AND USUAL
INTERIOR ZONES. GALE WATCH WILL REMAIN IN EFFECT FOR THE COASTAL
WATERS...NORTHERN INLAND WATERS...AND EAST ENTRANCE. FELTON
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD ADVISORY REMAINS IN EFFECT FOR THE CHEHALIS RIVER NEAR
GRAND MOUND IN THURSTON COUNTY.
PZ...GALE WARNING IN EFFECT FROM 2 AM TO 5 PM PDT SUNDAY FOR THE
CENTRAL AND EASTERN STRAIT OF JUAN DE FUCA.
SMALL CRAFT ADVISORIES ARE IN EFFECT FOR THE COASTAL
WATERS...WEST ENTRANCE TO THE STRAIT OF JUAN DE FUCA...
NORTHERN INLAND WATERS...ADMIRALTY INLET...AND PUGET SOUND/
HOOD CANAL.
SMALL CRAFT ADVISORY FOR ROUGH BAR UNTIL 11 PM PDT SUNDAY
FOR THE GRAYS HARBOR BAR.
GALE WATCH IN EFFECT FROM SUNDAY EVENING THROUGH MONDAY
EVENING FOR THE COASTAL WATERS...ADMIRALTY INLET...
ENTRANCES TO THE STRAIT OF JUAN DE FUCA...AND NORTHERN
INLAND WATERS.
&&
$$
WWW.WEATHER.GOV/SEATTLE
FOR THE GRAPHICAL AFD VISIT...
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
325 AM CDT SUN APR 1 2012
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
325 AM CDT SUN APR 1 2012
MAIN FORECAST CONCERNS ARE ON STRATUS TRENDS TODAY...AS WELL AS
PRECIPITATION CHANCES TONIGHT THROUGH MONDAY NIGHT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED DEEP TROUGHING ALONG THE WEST COAST OF THE U.S....BUILDING
RIDGING DOWNSTREAM ACROSS THE PLAINS INTO MANITOBA...AND TROUGHING
OVER SOUTHEAST CANADA. WITHIN THIS LATTER TROUGHING...A STRONG
SHORTWAVE WAS DROPPING SOUTHEAST THROUGH NORTHERN ONTARIO. WITH THE
BUILDING RIDGING/HEIGHTS AT 500MB TAKING PLACE NEAR AND WEST OF THE
FORECAST AREA...A WARM ADVECTION PATTERN IS IN PLACE. SOUNDINGS AT
GRB AND MPX REFLECT THIS...SHOWING 850MB TEMPS THAT ROSE TO 9C AT
15C RESPECTIVELY AT 00Z...COMPARED TO -2C AND 9C AT 12Z YESTERDAY.
THE WARM ADVECTION OCCURRING ALOFT WAS A PROBLEM GETTING RID OF THE
STRATUS DURING THE DAY YESTERDAY...PLUS THE DEPTH OF THE STRATUS AT
12Z WAS 75MB...BOTH MAKING IT TOUGHER TO MIX OUT. DURING THE
EVENING...INCREASING 925MB WINDS OF 30-40KT HELPED TO BRING DRIER
AIR BELOW 900MB SEEN ON THE 00Z DVN SOUNDING NORTHWARD...WHICH HAS
CLEARED OUT THE LOW CLOUDS UP TO A FARIBAULT MN TO OSHKOSH WI
LINE. SEEING SOME FOG DEVELOP IN THE CLEARING AREA. ACROSS
NORTHERN WISCONSIN...925MB WINDS HAVE TURNED NORTHWEST...IN THE
WAKE OF A COLD FRONT ABOVE THE SURFACE ASSOCIATED WITH THAT
NORTHERN ONTARIO SHORTWAVE. BACK FARTHER TO THE SOUTH...CONVECTION
ROLLED EAST ACROSS FAR SOUTHERN WISCONSIN...EASTERN IOWA INTO
NORTHERN ILLINOIS OVERNIGHT...ON THE NOSE OF A LOW LEVEL JET AND
SURFACE WARM FRONT WHICH SITS NOW NEAR I-80.
TODAY AND TONIGHT...UPPER RIDGING SEEN BUILDING OVER THE PLAINS WILL
SHIFT EAST THROUGH TONIGHT WITH THE AXIS RIGHT OVER THE FORECAST
AREA AT 12Z. WITH THE UPPER FLOW GAINING A LITTLE MORE
AMPLITUDE...THAT COLD FRONT SEEN IN 925MB PROFILER/VWP DATA LOOKS TO
DROP SOUTH THROUGH MUCH OF THE FORECAST AREA BETWEEN 12-18Z. THE
FRONT THEN STALLS OUT FOR THE AFTERNOON FROM SOUTHWEST MINNESOTA
INTO NORTHERN ILLINOIS. WITH THE 925MB WINDS VEERING NORTHEASTERLY
THEN SOUTHEASTERLY BEHIND THIS FRONT...THE STRATUS WILL MAKE ITS WAY
BACK SOUTH ACROSS WISCONSIN PORTIONS OF THE FORECAST AREA. QUESTION
THEN BECOMES FOR THE AFTERNOON...DOES THE STRATUS MIX OUT? FOR
YESTERDAY...THE 31.00Z NAM AND 31.00-07Z RUC MODELS...AS WELL AS THE
HRRR...WERE ALL SAYING THE STRATUS WOULD MIX OUT BY 19Z. SEEING THE
SAME THING FROM THESE MODELS TODAY. ONE ADVANTAGE TO CLEARING IS
THAT DRIER AIR IS LOWER IN THE ATMOSPHERE COMPARED TO THIS TIME
YESTERDAY...NOTED BETWEEN THE 12Z AND 00Z GRB SOUNDING. THIS DRIER
AIR LOOKS TO CONTINUE TO SINK TOWARDS THE SURFACE TODAY WHILE MIXING
OCCURS. THE COMBINATION OF THE TWO SHOULD BE ABLE TO SCOUR OUT THE
STRATUS. WITH THE STRATUS CONCERNS...HAVE LOWERED TEMPERATURES
CLOSER TO THE NAM12 AND REGIONAL CANADIAN 2 METER OUTPUT...WHICH
SEEMS REASONABLE. CERTAINLY IF CLOUDS STICK AROUND LONGER LIKE
YESTERDAY...THESE STILL MAY BE TOO HIGH. HOWEVER...DO NOT WANT TO
DROP TOO MUCH GIVEN ANY SUN AND 850MB TEMPS OF 12-16C COULD EASILY
JUMP TEMPERATURES WELL INTO THE 70S. TONIGHT...THE LINGERING
MOISTURE COULD REDEVELOP OR EXPAND INTO A STRATUS DECK WEST OF THE
MISSISSIPPI RIVER AS THE 925MB WINDS INCREASE OUT OF THE SOUTHEAST.
THE INCREASING WINDS ARE IN RESPONSE TO DEEPENING LOW PRESSURE OVER
NEBRASKA WITH AN INVERTED TROUGH EXTENDING NORTHEAST THROUGH WESTERN
MINNESOTA. SHOULD SEE A SURGE OF ISENTROPIC LIFT WITH THIS SYSTEM AS
WELL...WHICH SHOWS UP WELL ON 305K SURFACES IN THE 06-12Z MONDAY
TIME PERIOD FROM LA CROSSE SOUTHWESTWARD. SOUNDINGS CONTINUE TO
SUGGEST A CAPPING INVERSION AT 750MB TO PREVENT ACCAS THAT DEVELOPS
FROM THE LIFT INTO BECOMING DEEP CONVECTION. WILL CONTINUE THE DRY
FORECAST...BUT MONITORING OF THIS CAP IS NEEDED. FURTHER NORTH...
MODELS WERE SUGGESTING BEFORE CONVECTION POSSIBLY INTO TAYLOR
COUNTY. THIS IS NOW PROGGED TO STAY WELL OFF TO THE NORTHWEST...UP
NEAR DULUTH. THEREFORE HAVE PULLED THE 20 PERCENT CHANCES.
MONDAY THROUGH TUESDAY NIGHT...THE UPPER RIDGE OVER THE FORECAST
AREA IS PROGGED TO SLOWLY FALL APART...IN RESPONSE TO THE NORTHERN
PORTION OF THE CURRENT WESTERN TROUGH CROSSING FROM THE NORTHERN
PLAINS THROUGH THE WESTERN GREAT LAKES. THE TIMING OF THE NORTHERN
FEATURE CONTINUES TO BE A PROBLEM...WITH THE ECMWF/UKMET/CANADIAN
CONSISTENTLY REMAINING SLOWER THAN THE NAM/GFS. THIS HAS SIGNIFICANT
IMPLICATIONS ON TEMPERATURES AND ANY PRECIP TIMING. TRENDS IN THE
NAM/GFS SINCE THE 31.00Z RUNS HAVE SHOWN SOME SLOWING...THEREFORE
HAVE BIASED THE FORECAST TOWARDS THE SLOWER ECMWF/UKMET/CANADIAN.
ALL MODELS ARE SUGGESTING A DRIER FORECAST MONDAY...ESPECIALLY
DURING THE MORNING...AS ALL SYNOPTIC FORCING IS EITHER ACROSS
NORTHERN MINNESOTA OR BACK IN THE FRONTOGENETIC AREA BEHIND THE
INVERTED TROUGH CROSSING MINNESOTA. HAVE REDUCED PRECIPITATION
CHANCES SOME FOR MONDAY AND LATER FORECASTS MAY BE ABLE TO
COMPLETELY DRY IT OUT. WITH THE TRACK OF THE UPPER TROUGH...BEST
DPVA FORCING SHOULD CONTINUE TO STAY MORE TOWARDS THE NORTH FOR
MONDAY NIGHT. AS SUCH...WHEN YOU LOOK AT MODEL QPF FIELDS...MOST OF
THE QPF ENDS UP NORTH OF I-94. PLUS...500MB HEIGHT FALLS ARE ONLY
10-20 METERS TOPS FROM I-90 SOUTH. THEREFORE...REDUCED MONDAY
NIGHTS CHANCES ABOUT 10 PERCENT SOUTH OF I-90 AND KEPT 50 CHANCES
GOING NORTH OF I-94. SPC CONTINUES TO SHOW A 5% CHANCE OF SEVERE
WEATHER FOR MONDAY AND MONDAY NIGHT...BUT CONFIDENCE IS REALLY LOW
WITH PRECIPITATION IN THE FIRST PLACE SEEING MODEL TRENDS TOWARDS
DRIER OVERALL. INVERTED TROUGH SHOULD HAVE PUSHED THROUGH THE AREA
MONDAY NIGHT...ALLOWING A COOLER...DRIER AREA OF HIGH PRESSURE TO
BUILD IN FOR TUESDAY AND TUESDAY NIGHT. PREVIOUS FORECAST OF DRY
CONDITIONS FOR THIS TIME PERIOD STILL LOOKS GOOD...AS WELL AS THE
TEMPERATURES. REGARDING TEMPERATURES MONDAY AND MONDAY NIGHT...THESE
ARE TRICKY AS ALREADY MENTIONED TIMING OF THE TROUGH IS CRITICAL.
THERE COULD ALSO BE SOME STRATUS AND/OR ACCAS TO DEAL WITH MONDAY.
LASTLY...THE WIND FLOW MONDAY IS STILL EAST TO SOUTHEAST. ON THE
OTHER HAND...850MB TEMPS ARE 12-16C. FOR NOW COOLED HIGHS ACROSS
WISCONSIN WITH MORE CLOUDS AND CLOSER TO EASTERLY FLOW. LOCATIONS
LIKE OELWEIN AND CHARLES CITY COULD HIT 80...THOUGH.
.LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT
325 AM CDT SUN APR 1 2012
01.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES REMAIN IN GOOD AGREEMENT
OF AN OMEGA BLOCK PATTERN OVER CANADA AND THE U.S. FOR WEDNESDAY
THROUGH FRIDAY...THEN BEGINS TO BREAK DOWN HEADING INTO THE WEEKEND.
THE FORECAST AREA LIES EAST OF THE RIDGE AXIS IN THE OMEGA BLOCK...
WHICH IS IN THE DAKOTAS AND MINNESOTA THROUGH EARLY FRIDAY. THIS
FAVORS A RIDGE OF HIGH PRESSURE AT THE SURFACE WITH A COOL/DRY AIR
FEED OUT OF CANADA. STILL...TEMPERATURES LOOK LIKE THEY SHOULD END
UP A BIT ABOVE NORMAL. MAY HAVE TO DEAL WITH FROST FOR A FEW
NIGHTS...THOUGH. SOME WARMING SHOULD OCCUR ON FRIDAY AS THE UPPER
RIDGE AXIS MOVES IN AND THE SURFACE RIDGE MOVES EAST... ALLOWING A
SOUTHERLY RETURN FLOW TO DEVELOP. FOR THE WEEKEND...TROUGHING OVER
THE WESTERN U.S. IS EXPECTED TO EJECT OUT INTO THE NORTHERN
PLAINS...BRINGING A COLD FRONT INTO OR THROUGH THE FORECAST AREA
SATURDAY NIGHT. ENVISION THE WEEKEND TIMING OF ALL THIS WILL GET
ADJUSTED OVER THE COMING DAYS...AND HAVE SOME CONCERN THE MAJORITY
OF MODELS INCLUDING THE 01.00Z ECMWF ARE TOO FAST WITH THIS TIMING
GIVEN THE DOWNSTREAM RIDGE. THEREFORE...PRECIPITATION CHANCES WITH
THE WARM CONVEYOR BELT AHEAD OF THE COLD FRONT ARE HELD TO 20-30 AT
THIS TIME. DID NOT INTRODUCE ANY THUNDER BECAUSE THERE APPEARS TO BE
LIMITED INSTABILITY AT THIS TIME. TEMPERATURES SHOULD STAY ABOVE
NORMAL FOR FRIDAY NIGHT THROUGH SATURDAY NIGHT...UNTIL THE COLD
FRONT PASSES. EVEN BEHIND IT...READINGS COULD STAY NEAR OR ABOVE
NORMAL.
&&
.AVIATION...THROUGH 06Z MONDAY
1150 PM CDT SAT MAR 31 2012
CHALLENGING CLOUD FORECAST ONCE AGAIN FOR THIS SET OF TAFS. 925MB
WINDS HAVE BECOME MORE SOUTHERLY THROUGH THE EVENING HOURS WHICH
HAS PUSHED THE LOW STRATUS NORTH OF THE TAF SITES. 01.00Z HRRR
DOES SHOW THIS NORTHWARD TREND THROUGHOUT THE NIGHT...BEFORE
EXPANDING IT BACK SOUTHWARD BETWEEN 11Z-14Z. THE BIGGEST QUESTION
IS WILL THEY MAKE IT BACK IN TO KLSE AND KRST. BOTH THE 01.00Z RUC
AND NAM SHOWS THESE LOW LEVEL WINDS TO BECOME MORE EASTERLY BY 12Z
WHICH WOULD TEND TO FAVOR THE CLOUDS MOVING BACK SOUTHWARD OR
RE-DEVELOPING. FOR THE 06Z TAFS...DID BRING THE STRATUS BACK IN AT
BOTH SITES BETWEEN 13Z-19Z...ALONG WITH SOME REDUCED VISIBILITIES.
COULD BE SOME IFR CONDITIONS...ESPECIALLY AT KRST. STILL EXPECT
THESE TO SCATTERED OUT MIDDAY TO EARLY AFTERNOON SUNDAY AS
STRONGER PRESSURE GRADIENT INCREASES THE WINDS. VFR CONDITIONS
THEN WILL PERSIST THROUGH 06Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
325 AM CDT SUN APR 1 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS ALBANY NY
1038 AM EDT SUN APR 1 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE FROM THE GREAT LAKES AND ACROSS
THE REGION THIS AFTERNOON INTO TONIGHT...ALLOWING FOR SOME RAIN
SHOWERS. SOME WET SNOW MAY MIX IN WITH THE RAIN SHOWERS ACROSS THE
HIGHEST TERRAIN TONIGHT. HIGH PRESSURE WILL BUILD SOUTH INTO THE
REGION PROVIDING FAIR WEATHER FOR EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST VISIBLE SATELLITE IMAGERY SHOWS THAT LOWER STRATUS CLOUDS
HAVE COMPLETELY OVERTAKEN THE CWA. MEANWHILE...THE 12 UTC KALY
SOUNDING SHOWS ENOUGH DRY AIR IN PLACE FOR THE BOTTOM FEW THOUSAND
FEET OF THE COLUMN...AND BUFR MODEL SOUNDING SUPPORT THIS HOLDING
FOR A FEW HOURS AS WELL. THE LATEST REGIONAL RADAR IMAGERY
CONTINUES TO SHOW NO RETURNS ACROSS OUR AREA...BUT INCREASING
AMOUNTS OF LIGHT TO MODERATE PRECIP ACROSS WESTERN NY/LAKE
ONTARIO DUE TO A SHORTWAVE AND WEAK SURFACE LOW ACROSS THE GREAT
LAKES. FOR NOW...WILL CONTINUE TO FORECAST CLOUDY...BUT DRY
WEATHER FOR MUCH OF THE AREA THROUGH AROUND NOON.
FOR THE AFTERNOON HOURS...WILL STEADILY INCREASE POPS TO
CATEGORICAL FOR MOST AREAS BY THE LATE AFTN HOURS. THE NEW 12 UTC
NAM AND 10 UTC 3KM HRRR ALL SHOW BATCHES OF LIGHT RAIN SHOWERS
MOVING ACROSS THE AREA FROM NORTHWEST TO SOUTHEAST THROUGH THE
AFTN AND EVENING HOURS...WITH THE BEST QPF ACROSS THE
CATSKILLS...AS THE LOW PRESSURE WAVE MOVES ACROSS OUR AREA. ALTOUGH
QPF SHOULD BE FAIRLY LIGHT...ALL AREAS SEEM TO AT LEAST GET A FEW
HUNDREDTHS...SO HIGH LIKELY/CATEGORICAL POPS SEEM WARRANTED. MAX
TEMPS TODAY WILL PROBABLY BE IN THE EARLY AFTN JUST BEFORE THE
START OF PRECIP...WITH TEMPS RANGING FROM THE UPPER 30S ACROSS THE
SRN DACKS TO NEAR 50 IN THE MID HUDSON VALLEY.
AFTER 00 UTC...WILL START TO LOWER POPS FROM NORTHWEST TO
SOUTHEAST...AS MODEL GUIDANCES SHOWS THE BEST FORCING AND
ASSOCIATED PRECIPITATION DROPPING SOUTHEAST OF THE REGION. AT THE
HIGHEST TERRAIN /GENERALLY 2500 FT AND ABOVE/...ANY LINGERING RAIN
SHOWERS COULD START TO MIX WITH OR CHANGE OVER TO SNOW SHOWERS AS
TEMPS ALOFT START TO CRASH. ANY SNOW ACCUMULATION LOOKS VERY
LIGHT...OF ABOUT A HALF INCH OR SO...AND MAINLY LIMITED TO THE
HIGH PEAKS OF THE CATSKILLS AND HIGHEST ELEVATIONS IN SOUTHERN
VERMONT. A COATING OF SNOW IS POSSIBLE ACROSS THE SOUTHERN
ADIRONDACKS AS WELL. VALLEY AREAS WILL PROBABLY JUST STAY AS RAIN
SHOWERS BEFORE ENDING AND NO SNOW ACCUMULATION IS EXPECTED IN ANY
VALLEY AREAS AT THIS TIME.
ANY PRECIP SHOULD BE FINISHED BY AROUND 06 UTC...WITH CLEARING
TAKING PLACE FOR THE REMAINDER OF THE NIGHT...AS SKIES BECOME
PARTLY CLOUDY. THIS SHOULD ALLOW TEMPS TO FALL OFF...WITH MIN TEMPS
RANGING FROM THE 20S IN THE DACKS TO THE MID 30S IN THE CAPITAL
REGION/MID HUDSON VALLEY.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
MONDAY INTO TUESDAY MODEL SUITE IS IN AGREEMENT OTHER THAN 6-9
HOURS DIFFERENCE IN TIMING OF TUES CDFNT AND INTENSITY OF 500HPA
SHORT WAVES WED.
FAST MOVING FLOW AT 500HPA OVER RGN...AS 500HPA TROF DEPARTS...RIDGE
BUILDS EAST...ANOTHER SHORT WV FOLLOWS LATE TUESDAY. TUESDAY NIGHT
SOME DIFFERENCES BEGIN TO EMERGE. AT SFC MASSIVE HIGH BUILDS FM
HUDSONS BAY S INTO GRTLKS AS A SERIES OF STRONG 500HPA SHORT WVS
DIVE SE ACROSS THE RGN. THE MODEL SUITE GENERALLY (GFS/GEM/12UTC
ECMWF) ARE AGGRESSIVE WITH THE SHORT WAVES...THE NAM THE LEAST AND
THE OUTLIER. THE MORE AGGRESSIVE SHORT WV SOLUTION RESULTS IN SOME
INSTAB -SHRA/SN AT HIR TRRN...VRBL CLOUDS...BRISK N WINDS AND THIS
SOLUTION IS THE ONE THE FCST WILL LEAN TWRD WITH NAM BEING THROWN
OUT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
GFS AND ECMWF FAIRLY SIMILAR IN THIS PERIOD. 500HPA TROF OVER
MARITIMES WILL SLOWLY DEPART...MASSIVE SFC HIGH FM HUDSONS BAY
WILL BUILD INTO GRTLKS. FCA WILL BE BTWN THESE TWO SYSTEMS WITH
GENERALLY DRY CONDS...SOME CLOUDS INTO FRI AS 500 HPA SHORT WAVES
ROTATED ACROSS FCA. BY SAT SFC HIGH HAS MOVED INTO RGN. GFS SHIFTS
500HPA TROF OFFSHORE...ECMWF HAS CUTOFF FORM ALONG DELMARVA/SE
COAST WHILE GFS KEEPS PROGRESSIVE TROFS MOVING OFFSHORE. ECMWF
DEVELOPS POTENTIAL COASTAL SFC LOW THAT DRIFTS N WITH CUTOFF. THIS
SYSTEM BACKS INTO FCA SUN WITH CLDS AN LT RN. FOR NOW WILL GO
W/GMOS SOLUTION. SINCE ONLY DIFFERENCE IS IN DAYS 7-8. TEMPS WILL
REMAIN NR NRMLS...REACHING 5 DEGREES ABV BY END OF PD.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS DESPITE THE EXPANDING STRATUS DECK ACROSS THE
REGION. UPSTREAM SYSTEM APPROACHES DURING THE DAY WITH LOWER CIGS
AND INCREASING CHANCES FOR WET CONDITIONS. THERE WILL BE A PERIOD
LATER THIS AFTERNOON INTO EARLY EVENING WITH MVFR FLIGHT
CONDITIONS.
WINDS WILL BE LIGHT AND VARIABLE THIS EARLY SUNDAY MORNING. THOSE
WINDS BECOME WEST-SOUTHWEST LATE THIS MORNING IN ADVANCE OF THIS
SYSTEM AT SPEEDS LESS THAN 10KTS. WINDS QUICKLY SHIFT TO THE
NORTH-NORTHWEST IN THE WAKE OF THIS STORM THIS EVENING AROUND 10 KTS
AND CONTINUE OVERNIGHT.
OUTLOOK...
MON-TUE...VFR...NO SIG WX.
TUE NT...MAINLY VFR...CHC -RA OR -SHRA.
WED-THU...VFR...NO SIG WX.
&&
.FIRE WEATHER...
LOW PRESSURE DROPPING SOUTHEAST FROM THE GREAT LAKES WILL MOVE
ACROSS THE REGION TODAY INTO THIS EVENING...THEN A MASSIVE HIGH
PRESSURE WILL BUILD SOUTH INTO THE REGION FOR EARLY NEXT WEEK.
AS SHOWERS MOVE ACROSS THE REGION...RELATIVE HUMIDITY VALUES WILL
GENERALLY REMAIN ABOVE 50 PERCENT. AS THIS SYSTEM DEPARTS
TONIGHT...THE WET WEATHER ALSO SUBSIDES AS RELATIVE HUMIDITIES RANGE
BETWEEN 80 AND 90 PERCENT.
SURFACE WINDS WILL BE WEST-SOUTHWEST AT 5 TO 15 MPH TODAY...BECOMING
NORTHERLY TONIGHT AT 10 MPH OR LESS...THEN INCREASING TOWARD SUNRISE
AND THROUGH THE DAY MONDAY WITH GUSTS OVER 20 MPH.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED FOR THE NEXT FIVE DAYS.
THE ONLY PCPN EXPECTED IN THE NEXT WEEK WILL BE A QUARTER TO THIRD
INCH TODAY...ISOLATED -SHRA LATE TUESDAY. OTHERWISE WILL BE DRY
WITH TEMPS BLO NORMAL AT FIRST...RISING NEAR NORMAL MID WEEK AND
ENDING THE WEEK ABV NORMALS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...BGM
FIRE WEATHER...BGM
HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
634 AM EDT SUN APR 1 2012
.SYNOPSIS...
LOW PRESSURE DROPPING SOUTHEAST FROM THE GREAT LAKES WILL MOVE
ACROSS THE REGION TODAY. A LOBE OF HIGH PRESSURE WILL BUILD SOUTH
INTO THE REGION FROM HUDSON BAY MONDAY...AND SLIDE OFFSHORE
TUESDAY. LATE TUESDAY A COLD FRONT DROP THROUGH THE REGION.
WEDNESDAY THROUGH THE END OF THE WEEK...THE REST OF THE HUDSONS
BAY HIGH PRESSURE AREA WILL BUILD INTO THE GREAT LAKES WHILE A
STORM LINGERS IN THE MARITIMES.
&&
.NEAR TERM /THROUGH TONIGHT/...
STRATUS DECK EXPANDING SLOWLY THIS EARLY SUNDAY MORNING PER
THE 11U-3.9U IMAGERY. MEANWHILE...AN INCREASE IN HIGH LEVEL
MOISTURE WAS UNDERWAY FROM THE CLIPPER TYPE SYSTEM ACROSS THE
NORTHERN GREAT LAKES REGION. PER THE SATELLITE DERIVED WINDS...THE
UPPER JET WAS GREATER THAN 120KTS...SO A RATHER DYNAMIC SYSTEM.
FORECAST BUFR PROFILES ALL SUGGEST THE LOW LEVEL DRY AIR WILL HANG
ON TOUGH THROUGH MOST OF THE MORNING AND WILL CUT BACK POPS
ACCORDINGLY. LATEST RUC13/HRRR DOES SUGGEST SHOWER ACTIVITY WILL
DEVELOP AND BECOME ENHANCED WITH FAVORABLE UPSLOPE CONDITIONS
THROUGH THE NOON HOUR AND INTO THE AFTERNOON AND WE WILL RAISE POPS
INTO THE LIKELY CATEGORY. LATEST HRRR CONTINUES ALONG THIS FORECAST
LINE THIS SUNDAY MORNING.
THERMAL PROFILES ARE CHILLY YET THOSE BOUNDARY LAYER VALUES ARE
EXPECTED TO REMAIN RATHER MILD TODAY. THE FREEZING LEVEL FORECASTS
FROM THE NCEP MODEL SUITE SUGGEST FOR SNOW LEVELS WILL BE RATHER
HIGH...AT OR ABOVE 2K FEET. SO FOR MOST OF THE REGION...EXPECTATIONS
ARE FOR MAINLY RAIN/RAIN SHOWERS TODAY UNDER CLOUDY SKIES. WE WILL
SHADE A LITTLE CLOSER TO THE COOLER SIDE OF THE GUIDANCE ENVELOPE
WHICH IS IN LINE WITH THE LATEST LAV/LAMP.
PRECIP WILL END FROM NORTHWEST TO SOUTHEAST THIS EVENING WITH THE
QUICK DEPARTURE OF THIS SYSTEM. SOME UPSLOPE CLOUD
ENHANCEMENT...ESPECIALLY FOR OUR ADJACENT WESTERN NEW ENGLAND
COUNTIES...ARE EXPECTED BUT WE WILL DIMINISH THOSE POPS ACCORDINGLY.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
MONDAY INTO TUESDAY MODEL SUITE IS IN AGREEMENT OTHER THAN 6-9
HOURS DIFFERENCE IN TIMING OF TUES CDFNT AND INTENSITY OF 500HPA
SHORT WAVES WED.
FAST MOVING FLOW AT 500HPA OVER RGN...AS 500HPA TROF DEPARTS...RIDGE
BUILDS EAST...ANOTHER SHORT WV FOLLOWS LATE TUESDAY. TUESDAY NIGHT
SOME DIFFERENCES BEGIN TO EMERGE. AT SFC MASSIVE HIGH BUILDS FM
HUDSONS BAY S INTO GRTLKS AS A SERIES OF STRONG 500HPA SHORT WVS
DIVE SE ACROSS THE RGN. THE MODEL SUITE GENERALLY (GFS/GEM/12UTC
ECMWF) ARE AGGRESSIVE WITH THE SHORT WAVES...THE NAM THE LEAST AND
THE OUTLIER. THE MORE AGGRESSIVE SHORT WV SOLUTION RESULTS IN SOME
INSTAB -SHRA/SN AT HIR TRRN...VRBL CLOUDS...BRISK N WINDS AND THIS
SOLUTION IS THE ONE THE FCST WILL LEAN TWRD WITH NAM BEING THROWN
OUT.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
GFS AND ECMWF FAIRLY SIMILAR IN THIS PERIOD. 500HPA TROF OVER
MARITIMES WILL SLOWLY DEPART...MASSIVE SFC HIGH FM HUDSONS BAY
WILL BUILD INTO GRTLKS. FCA WILL BE BTWN THESE TWO SYSTEMS WITH
GENERALLY DRY CONDS...SOME CLOUDS INTO FRI AS 500 HPA SHORT WAVES
ROTATED ACROSS FCA. BY SAT SFC HIGH HAS MOVED INTO RGN. GFS SHIFTS
500HPA TROF OFFSHORE...ECMWF HAS CUTOFF FORM ALONG DELMARVA/SE
COAST WHILE GFS KEEPS PROGRESSIVE TROFS MOVING OFFSHORE. ECMWF
DEVELOPS POTENTIAL COASTAL SFC LOW THAT DRIFTS N WITH CUTOFF. THIS
SYSTEM BACKS INTO FCA SUN WITH CLDS AN LT RN. FOR NOW WILL GO
W/GMOS SOLUTION. SINCE ONLY DIFFERENCE IS IN DAYS 7-8. TEMPS WILL
REMAIN NR NRMLS...REACHING 5 DEGREES ABV BY END OF PD.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS DESPITE THE EXPANDING STRATUS DECK ACROSS THE
REGION. UPSTREAM SYSTEM APPROACHES DURING THE DAY WITH LOWER CIGS
AND INCREASING CHANCES FOR WET CONDITIONS. THERE WILL BE A PERIOD
LATER THIS AFTERNOON INTO EARLY EVENING WITH MVFR FLIGHT
CONDITIONS.
WINDS WILL BE LIGHT AND VARIABLE THIS EARLY SUNDAY MORNING. THOSE
WINDS BECOME WEST-SOUTHWEST LATE THIS MORNING IN ADVANCE OF THIS
SYSTEM AT SPEEDS LESS THAN 10KTS. WINDS QUICKLY SHIFT TO THE
NORTH-NORTHWEST IN THE WAKE OF THIS STORM THIS EVENING AROUND 10 KTS
AND CONTINUE OVERNIGHT.
OUTLOOK...
MON-TUE...VFR...NO SIG WX.
TUE NT...MAINLY VFR...CHC -RA OR -SHRA.
WED-THU...VFR...NO SIG WX.
&&
.FIRE WEATHER...
LOW PRESSURE DROPPING SOUTHEAST FROM THE GREAT LAKES WILL MOVE
ACROSS THE REGION TODAY INTO THIS EVENING...THEN A MASSIVE HIGH
PRESSURE WILL BUILD SOUTH INTO THE REGION FOR EARLY NEXT WEEK.
AS SHOWERS MOVE ACROSS THE REGION...RELATIVE HUMIDITY VALUES WILL
GENERALLY REMAIN ABOVE 50 PERCENT. AS THIS SYSTEM DEPARTS
TONIGHT...THE WET WEATHER ALSO SUBSIDES AS RELATIVE HUMIDITIES RANGE
BETWEEN 80 AND 90 PERCENT.
SURFACE WINDS WILL BE WEST-SOUTHWEST AT 5 TO 15 MPH TODAY...BECOMING
NORTHERLY TONIGHT AT 10 MPH OR LESS...THEN INCREASING TOWARD SUNRISE
AND THROUGH THE DAY MONDAY WITH GUSTS OVER 20 MPH.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED FOR THE NEXT FIVE DAYS.
THE ONLY PCPN EXPECTED IN THE NEXT WEEK WILL BE A QUARTER TO THIRD
INCH TODAY...ISOLATED -SHRA LATE TUESDAY. OTHERWISE WILL BE DRY
WITH TEMPS BLO NORMAL AT FIRST...RISING NEAR NORMAL MID WEEK AND
ENDING THE WEEK ABV NORMALS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...BGM
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...BGM
FIRE WEATHER...BGM
HYDROLOGY...BGM
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1051 AM CDT SUN APR 1 2012
.DISCUSSION...
ISSUED 1040 AM CDT SUN APR 1 2012
PRECIP ASSOCIATED WITH EXITING MCS WELL OFF TO THE EAST LEAVING
SUNNY SKIES IN ITS WAKE. TEMPERATURES ARE QUICK TO REBOUND AS
WELL...LENDING MORE CONFIDENCE TO THE WARM FORECAST. NEWEST NAM
KEEPS AFTERNOON DRY...CONSIDERING THE RAPID RETREAT OF THE SHOWERS
THIS MORNING...WILL KEEP ISL WORDING...AND NOT RAISE THE POP THIS
AFTERNOON IN THE EAST. MINOR TWEAKS TO HRLY AND POP GRIDS. UPDATE
OUT MOMENTARILY.
HJS
&&
.AVIATION...
ISSUED 655 AM CDT SUN APR 1 2012...FOR THE 12Z TAFS
THE ONLY LINGERING MVFR CONDITIONS ARE IN DEC WITH 5SM BR AT
1145Z. STORMS HAVE MOVE EAST OF CMI...AN NO PRECIP SHOULD AFFECT
ANY OF THE TERMINALS FOR MOST OF THE DAY. ACTUALLY...ALL OUR TERMINALS
SHOULD BE VFR FOR MOST OF THE NEXT 24 HOURS.
FORECAST SOUNDINGS CONFIRM WHAT THE CU RULE IS INDICATING FOR VFR
CLOUD REDEVELOPMENT THIS AFTERNOON. THOSE CLOUDS MAY REDUCE HIGH
TEMPS A LITTLE, BUT IT WILL STILL BE A VERY WARM DAY.
SOME LIGHT MVFR FOG MAY FORM AGAIN LATER TONIGHT...AS A BACK DOOR
COLD FRONT DROPS SOUTH INTO CENTRAL IL FROM NORTHERN IL AND N
INDIANA. THE PRIMARY FOCUS FOR PRECIP WILL BE IN THE EAST...FOR
CMI AND POSSIBLY DEC. WE INTRODUCED A VCSH WITH CB IN CMI AFTER
10Z.
WINDS WILL SHIFT FROM SOUTHEAST EARLY IN THE TAF PERIOD TO
SOUTHWEST BY MID MORNING. WIND SPEEDS MAY REACH UP NEAR 20KT AT
TIMES DURING PEAK MIXING OF LATE MORNING/EARLY AFTERNOON. AS THE
COLD FRONT DROPS INTO C IL TONIGHT...WINDS WILL SHIFT EAST-
SOUTHEAST AGAIN...REMAINING IN THE 10-13KT RANGE FOR MOST TERMINAL
SITES. LIGHT MVFR FOG MAY REDEVELOP LATE TONIGHT...ESPECIALLY FOR
OUR NORTHERN TAFS OF PIA/BMI/CMI. MVFR CLOUDS WILL BE POSSIBLE AS
WELL.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 300 AM CDT SUN APR 1 2012
SMALL MCS FORMED AS EXPECTED OVER EASTERN IOWA LATE IN THE
EVENING...AND HAS BEEN MOVING ACROSS THE NORTHERN CWA
OVERNIGHT...PRODUCING SEVERE HAIL AT TIMES. HAVE SEEN SOME
SHOWERS/STORMS AS FAR SOUTH AS LINCOLN AT 2 AM.
SHORT TERM...TODAY THROUGH TUESDAY...
LATEST HRRR MODEL...WHICH HAS A GOOD HANDLE ON THE ACTIVITY...
SHOWS MUCH OF THE RAIN SHOULD LARGELY BE OUT OF THE CWA BY
SUNRISE. WILL MAKE A LAST MINUTE DECISION ON HOW LONG TO LINGER IT
THIS MORNING. ONCE THAT CLEARS OUT...TEMPERATURES BECOME THE
PRIMARY FOCUS. STILL LOOKING FOR HIGHS IN THE 80S ACROSS THE
ENTIRE AREA...CLOSE TO THE DAILY RECORDS. HOWEVER...EVENING MODEL
RUNS SHOWING A FRONTAL BOUNDARY NEAR THE I-80 CORRIDOR WILL LIKELY
SLIP A BIT SOUTHWARD THIS AFTERNOON...DRIVEN BY A RATHER STIFF
NORTHEAST FLOW. IF IT SLIPS TOO FAR...THEN TEMPERATURES ACROSS THE
NORTHEAST CWA MAY END UP BEING COOLER THAN EXPECTED. WRF MODEL OUT
OF WFO CHICAGO HAS THE BOUNDARY ALMOST ALL THE WAY TO I-74 BY
6 PM. WILL NEED TO WATCH THIS CLOSELY DURING THE AFTERNOON.
BOUNDARY WILL PROBABLY REACH AT LEAST INTO PART OF THE CWA THIS
EVENING...BEFORE BEGINNING TO RETREAT. SAME PROBLEM EXISTS WITH
TEMPERATURES MONDAY AFTERNOON...DUE TO ITS POSITION. HAVE PULLED
HIGH TEMPERATURES DOWN A BIT NORTH OF I-74...BUT STILL GOING A FEW
DEGREES ABOVE GUIDANCE IN THAT AREA. REMAINDER OF THE CWA MORE
LIKELY TO REACH THE 85-90 DEGREE RANGE...AGAIN NEAR THE RECORDS.
TIMING OF COLD FRONTAL PASSAGE TUESDAY MORNING APPEARS TO HAVE
SLOWED A BIT FROM EARLIER RUNS...SO HAVE KEPT TEMPERATURES SOUTH
OF I-70 WARMER THAN PREVIOUSLY FORECAST...WITH LOWER 80S.
THREAT OF SHOWERS/STORMS TO CONTINUE INTO THE AFTERNOON WITH THE
BOUNDARY IN THE AREA.
LONG TERM...WEDNESDAY THROUGH SATURDAY...
STILL LOOKING TO BE MUCH COOLER THAN THE START OF THE WEEK...ALTHOUGH
STILL A BIT ABOVE NORMAL. FOCUS IN THIS PERIOD REMAINS WITH A
CUTOFF LOW WHICH WILL DEVELOP OVER THE SOUTHERN ROCKIES EARLY IN
THE WEEK. LONGER RANGE MODELS IN REASONABLE AGREEMENT WITH A TRACK
THAT TAKES IT SOUTH OF THE OHIO VALLEY...BUT WILL STILL SEE THE
RAIN SHIELD ON THE NORTHERN FLANK EXTEND WELL TO THE NORTH. HAVE
CUT BACK ON THE RAIN ACROSS THE NORTHERN CWA FOR WEDNESDAY/THURSDAY...
WITH THE PERSISTENT NORTHEAST FLOW BRINGING DRIER AIR INTO CENTRAL
ILLINOIS. MAINLY DRY CONDITIONS EXPECTED LATE IN THE WEEK...AS A
NARROW RIDGE OF HIGH PRESSURE MOVES INTO THE MISSISSIPPI VALLEY.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
1005 AM CDT SUN APR 1 2012
.DISCUSSION...
1005 AM CDT
THE EARLY MORNING STORMS HAVE MOVED QUICKLY SOUTHEAST INTO
SOUTHERN INDIANA. IN THEIR WAKE...THEY HELPED TO SINK THE FRONTAL
BOUNDARY SOUTH TO NEAR INTERSTATE 88 AT AROUND 10 AM. TO THE
NORTH...WHERE STRATUS AND NORTHERLY WINDS PREVAIL...TEMPERATURES
HAVE BEEN BASICALLY FLAT LINE. WHILE SOME MIXING OUT OF THE
STRATUS MAY OCCUR LATE THIS MORNING...REINFORCING NORTHEAST COLD
AIR ADVECTION WILL EVOLVE AS A WEAK LOW SHIFTS EAST ALONG THE
FRONTAL BOUNDARY. THIS SCENARIO SHOULD ENABLE THE FRONT TO MOVE
SOUTH KEEPING TEMPERATURES COOLER TO THE NORTH...WITH PLACES
SEEING A FALL THIS AFTERNOON ESPECIALLY IN THE NEAR DOWNSTREAM OF
LAKE MICHIGAN. THE 01.12 NAM CAPTURES THIS TREND WELL...AND SEEMS
TO HAVE A DECENT HANDLE ON THE STRATUS EVOLUTION...HINTING AT LOW
CLOUDS ALONG AND IMMEDIATELY BEHIND THE BOUNDARY THROUGH THIS
AFTERNOON.
IT IS A TALE OF TWO DIFFERENT DAYS ACROSS THE CWA AS TO THE SOUTH
OF THE FRONT...TEMPERATURES ARE OFF TO THE RACES WITH MID 60S
ALREADY AT 10 AM IN PERU AND PONTIAC. A WARM-UP TO AROUND OR JUST
ABOVE 80 DEGREES STILL LOOKS WELL IN PLACE...ESPECIALLY SEEING
GUSTS TO AROUND 20 KTS ALREADY INDICATING GOOD MIXING AND
CONTINUED LOW- LEVEL WARM AIR ADVECTION. THE 12Z ILX RAOB HAD NEAR
1300 J/KG OF MUCAPE WHICH SHOULD BE A GOOD BASELINE FOR WHAT IS
SHIFTING OVER THE SOUTHERN FORECAST AREA AS IT CONTINUES TO WARM.
THIS LOOKS TO MAXIMIZE/POOL THIS AFTERNOON BETWEEN 1500 AND 2000
J/KG IN THE FAR SOUTH...BUT IN THE ABSENCE OF ANY PRONOUNCED
TRIGGER AND A QUICKLY WEAKENING LOW- LEVEL JET. THE WEAK SURFACE
CIRCULATION ALONG THE BOUNDARY MAY HELP TO INCREASE CONVERGENCE
SOME AS IT SHIFTS EAST THROUGH THE AFTERNOON. ALSO...AN ILL-
DEFINED SHORT WAVE RIPPLE IN EASTERN IA IS SHIFTING EAST. TOGETHER
IT MIGHT BE ENOUGH TO SPARK ISOLATED THUNDERSTORMS...GENERALLY
SOUTH OF U.S. HIGHWAY 24 THIS AFTERNOON. ABOUT ONE THIRD OF
EXPLICIT CONVECTIVE GUIDANCE LOOKED AT HAS THAT FORM OF SOLUTION.
INSTABILITY PROFILES ARE ENOUGH TO WARRANT MAINLY A HAIL THREAT IF
ANY STORM WERE TO SUSTAIN ITSELF.
MTF
&&
.PREV DISCUSSION...
315 AM CDT
THIS MORNING HIGH PRESSURE OVER THE EASTERN GREAT LAKES REGION WILL
PUSH EASTWARD WITH FRONTAL BOUNDARY SLOWLY TRYING TO LIFT NORTHWARD
THROUGH THE EARLY MORNING HOURS. ONGOING ELEVATED CONVECTION ON NOSE
OF LOW LEVEL JET WILL CONTINUE TO PUSH SOUTHEAST ACROSS THE REGION
RIDING H5 HEIGHTS DOWN THE RIDGE ALONG THE INSTABILITY GRADIENT.
SEVERE THREAT THROUGH THE PREDAWN HOURS WILL REMAIN MARGINAL...BUT
LATEST RUC CONTINUES TO SHOW NEAR 1000 J/KG GENERALLY ALONG AND WEST
OF THE I39 CORRIDOR SUPPORTING AT LEAST SOME THREAT FOR HAIL. THREAT
SHOULD TAPER THROUGH DAYBREAK THIS MORNING AS LOW LEVEL JET VEERS
AND THETA E ADVECTION WEAKENS. MEANWHILE...WEAK AREA OF LOW
PRESSURE NEAR LAKE SUPERIOR WILL PUSH EAST INTO SOUTHEASTERN
ONTARIO BY EARLY THIS AFTERNOON. GUIDANCE SUGGESTS BAROCLINIC ZONE
WILL BE FARTHER SOUTH/WEST THAN ORIGINALLY ANTICIPATED THUS BUMPED
DOWN TEMPERATURES SLIGHTLY ACROSS THE AREA FOR THIS AFTERNOON. IN
ADDITION WINDS TURNING TO THE NORTHEAST BY MID MORNING IN RESPONSE
TO LOW MOVING ACROSS ONTARIO WILL LIMIT HIGH TEMPS ALONG THE LAKE
SHORE...WITH TEMPERATURES FALLING INLAND THROUGH THE AFTERNOON AS
MARINE LAYER SPREADS INLAND.
MONDAY...GUIDANCE CONTINUES TO STRUGGLE WITH PLACEMENT OF BAROCLINIC
ZONE/LOW PRESSURE. A LARGE TEMPERATURE SPREAD IS STILL EXPECTED TO
SET UP ACROSS THE CWA. MAJORITY OF GUIDANCE SHOWS SOUTHWEST PORTIONS
OF THE CWA TRYING TO REACHING THE 80 MARK...BUT WARMER TEMPERATURES
ARE NOW EXPECTED TO BE FARTHER WEST. ALSO HAD TO DROP TEMPERATURES
ALONG THE LAKE FRONT SEVERAL DEGREES AS LATEST GUIDANCE IN GENERAL
SUGGESTS 60S POSSIBLY EVEN 50S AS WE STAY UNDER SOUTHEAST FLOW
THROUGH THE DAY WITH WINDS OFF THE LAKE IN ILLINOIS. AM CONCERNED
TEMPS ARE STILL A LITTLE HIGH THOUGH FOR MONDAY ALONG THE ILLINOIS
SHORES.
TUESDAY THOUGH SATURDAY...COLD FRONT WILL SWEEP ACROSS THE REGION
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS.
BROAD AREA OF HIGH PRESSURE BUILDS ACROSS THE CANADIAN PRAIRIES EAST
TOWARDS THE GREAT LAKE REGION THROUGH THE END OF THE WEEK. NORTHERN
ILLINOIS AND NORTHWEST INDIANA WILL BE IN AREA OF NORTHERLY FLOW AND
EXPECT TO BE CLIPPED BY COOLER AIR ALOFT //H85 TEMPS FALLING TO
AROUND -3C THURSDAY// BEHIND THE COLD FRONT. SHOULD SEE PLENTY OF
SUNSHINE FOR THE LATTER HALF OF THE WEEK. TEMPERATURES WILL CONTINUE
TO RUN SLIGHTLY ABOVE NORMAL...BUT SHOULD BE MORE SEASONABLE WITH
HIGHS IN THE UPPER 50S TO LOW 60S AND LOWS IN THE UPPER 30S TO LOW
40S. BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* FOG WITH VIS OF 3-5SM THROUGH LATE MORNING...WITH CONDITIONS
IMPROVING BY MID DAY.
* POTENTIAL REMAINING FOR A PERIOD OF MVFR CEILINGS 1500-2000 FT
LATE MORNING TO MID AFTERNOON.
* NORTHEAST WINDS STEADILY INCREASING THROUGHOUT THE DAY...WITH
SOME GUSTS POSSIBLE IN THE AFTERNOON.
RODRIGUEZ
//DISCUSSION...UPDATED 12Z...
EXPECT SOME RATHER VARIABLE CONDITIONS THROUGH EARLY AFTERNOON IN
TERMS OF WINDS/CIGS/VSBY. CURRENTLY...SHRA/TSRA ACTIVITY ACROSS
FAR NE IL IS MOVING INTO NW IN AND WILL EXIT TO THE EAST OF GYY
TOWARD 14Z. NEXT CONCERNS ARE RELATED TO WEAK LOW PRESSURE WHICH
WILL MOVE ALONG A FRONTAL BOUNDARY EXTENDING FROM NEAR KCID TO
KRPJ TO JUST NORTH OF KPWK THIS MORNING. THIS FRONT IS EXPECTED TO
SAG SOUTHWARD THROUGH THE MORNING BRINGING WINDS TO THE NORTHEAST
ACROSS THE CHI AND NW IN TERMINALS...WITH RFD ALREADY SEEING NE
WINDS. AS THE FRONT MOVES WINDS WILL LIKELY BECOME LIGHT AND
VARIABLE WITH A SOUTH TO WEST DIRECTION. GIVEN THE RAINFALL THIS
MORNING AND THE LIGHT WIND REGIME EXPECT THAT MVFR VSBY WILL
PREVAIL...WITH SOME IFR TOWARDS DPA AND RFD...THROUGH AT LEAST MID
MORNING AND POSSIBLY LONGER. IN ADDITION...FORECAST SOUNDINGS
CONTINUE TO SHOW DEVELOPMENT OF MVFR LEVEL STRATUS DECK BY MIDDAY
WHICH WOULD THEN SCATTER LATER THIS AFTERNOON. THIS SEEMS
PLAUSIBLE GIVEN THE SHIFT TO A COOLER NORTHEASTERLY FLOW OFF THE
LAKE AND THE ABUNDANT LOW LEVEL MOISTURE ALREADY IN PLACE. THERE
IS A CHANCE THAT MIST/HAZE WILL CONTINUE THROUGH THE AFTERNOON AS
WELL BUT CONFIDENCE IS LOW.
NORTHEAST WINDS WILL TURN EASTERLY TONIGHT AS RIDGING BUILDS TO
THE EAST AND LOW PRESSURE TAKES SHAPE ACROSS THE CENTRAL PLAINS.
VFR SHOULD PREVAIL BUT SOME MVFR VSBY REDUCTION IS POSSIBLE LATE.
WINDS WILL THEN TURN MORE SOUTHEASTERLY MONDAY MORNING.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM HIGH CONFIDENCE OF FOG/VIS TRENDS WITH MEDIUM CONFIDENCE
OF TIMING IMPROVEMENT.
* LOW MEDIUM CONFIDENCE OF A PERIOD OF 1500-2000 FT CEILINGS LATE
MORNING INTO THIS AFTERNOON.
* HIGH CONFIDENCE IN WIND SPEED AND DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...VFR WITH CHANCE TSRA.
TUESDAY...VFR WITH CHANCE SHRA/TSRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
MDB
&&
.MARINE...
210 AM CDT
HIGH PRESSURE OVER OHIO EXTENDS NORTHEASTWARD ACROSS THE ST.
LAWRENCE VALLEY THIS MORNING WHILE A COMPLEX SERIES OF WEAK LOW
PRESSURE SYSTEMS ARE NOTED FROM LAKE SUPERIOR INTO THE MID
MISSISSIPPI RIVER VALLEY...WITH BETTER ORGANIZED LOW PRESSURE IN THE
LEE OF THE ROCKIES. ONE LOW...OVER LAKE SUPERIOR...WILL MOVE
SOUTHEASTWARD TODAY AND MOVE OFF THE EAST COAST THIS EVENING WHERE
IT WILL DEEPEN. ANOTHER AREA OF LOW PRESSURE OVER WESTERN IOWA
WILL DRIFT EAST WITH A COOL FRONTAL BOUNDARY SETTING UP FROM THE
FIRST LOW INTO THIS WEAKER LOW. HIGH PRESSURE WILL THEN SPREAD
SOUTHWARD FROM HUDSON BAY AND INTO THE GREAT LAKES BEHIND THE
LOW. AS A RESULT OF THIS FAIRLY COMPLEX PATTERN SOUTHERLY WINDS IN
PLACE ACROSS LAKE MICHIGAN THIS MORNING WILL TURN NORTHEASTERLY
TODAY AND EASTERLY TONIGHT...BEFORE BECOMING SOUTHEAST FOR MONDAY.
IT APPEARS THAT THERE WILL BE SEVERAL PERIODS OF STRONGER WINDS
FROM TONIGHT THROUGH TUESDAY AS THE PRESSURE GRADIENT MODULATES
BETWEEN SYSTEMS. THE FIRST INCREASE SHOULD OCCUR TONIGHT ACROSS
CENTRAL AND SOUTHERN PARTS OF THE LAKE WITH GUSTS TO AROUND 25 KT
EXPECTED. SPEEDS LOOK TO EASE SOMEWHAT MONDAY BEFORE INCREASING
AGAIN MONDAY EVENING THEN DROPPING OFF TUESDAY MORNING AS A LOW
PASSES JUST TO THE SOUTH. THE GRADIENT TIGHTENS BEHIND THE LOW
TUESDAY AFTERNOON AS STRONG HIGH PRESSURE SPREADS INTO THE UPPER
MISSISSIPPI RIVER VALLEY. THIS LOOKS TO BE THE PERIOD OF STRONGEST
WINDS WITH 30 KT POSSIBLE FROM THE NORTH. THE HIGH THEN GRADUALLY
SPREADS EASTWARD KEEPING ITS INFLUENCE OVER THE LAKE THROUGH THE
END OF THE WEEK. LOWS WILL PASS TO THE EAST AND SOUTH OF THE LAKE
SO PERIODS OF SLIGHTLY STRONGER WINDS WILL BE POSSIBLE DESPITE THE
PRESENCE OF THE HIGH...BUT HIGHEST SPEEDS LOOK TO BE UNDER 20 KTS
OR SO FROM MID WEEK ONWARD.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
912 AM CDT SUN APR 1 2012
.DISCUSSION...
315 AM CDT
THIS MORNING HIGH PRESSURE OVER THE EASTERN GREAT LAKES REGION WILL
PUSH EASTWARD WITH FRONTAL BOUNDARY SLOWLY TRYING TO LIFT NORTHWARD
THROUGH THE EARLY MORNING HOURS. ONGOING ELEVATED CONVECTION ON NOSE
OF LOW LEVEL JET WILL CONTINUE TO PUSH SOUTHEAST ACROSS THE REGION
RIDING H5 HEIGHTS DOWN THE RIDGE ALONG THE INSTABILITY GRADIENT.
SEVERE THREAT THROUGH THE PREDAWN HOURS WILL REMAIN MARGINAL...BUT
LATEST RUC CONTINUES TO SHOW NEAR 1000 J/KG GENERALLY ALONG AND WEST
OF THE I39 CORRIDOR SUPPORTING AT LEAST SOME THREAT FOR HAIL. THREAT
SHOULD TAPER THROUGH DAYBREAK THIS MORNING AS LOW LEVEL JET VEERS
AND THETA E ADVECTION WEAKENS. MEANWHILE...WEAK AREA OF LOW
PRESSURE NEAR LAKE SUPERIOR WILL PUSH EAST INTO SOUTHEASTERN
ONTARIO BY EARLY THIS AFTERNOON. GUIDANCE SUGGESTS BAROCLINIC ZONE
WILL BE FARTHER SOUTH/WEST THAN ORIGINALLY ANTICIPATED THUS BUMPED
DOWN TEMPERATURES SLIGHTLY ACROSS THE AREA FOR THIS AFTERNOON. IN
ADDITION WINDS TURNING TO THE NORTHEAST BY MID MORNING IN RESPONSE
TO LOW MOVING ACROSS ONTARIO WILL LIMIT HIGH TEMPS ALONG THE LAKE
SHORE...WITH TEMPERATURES FALLING INLAND THROUGH THE AFTERNOON AS
MARINE LAYER SPREADS INLAND.
MONDAY...GUIDANCE CONTINUES TO STRUGGLE WITH PLACEMENT OF BAROCLINIC
ZONE/LOW PRESSURE. A LARGE TEMPERATURE SPREAD IS STILL EXPECTED TO
SET UP ACROSS THE CWA. MAJORITY OF GUIDANCE SHOWS SOUTHWEST PORTIONS
OF THE CWA TRYING TO REACHING THE 80 MARK...BUT WARMER TEMPERATURES
ARE NOW EXPECTED TO BE FARTHER WEST. ALSO HAD TO DROP TEMPERATURES
ALONG THE LAKE FRONT SEVERAL DEGREES AS LATEST GUIDANCE IN GENERAL
SUGGESTS 60S POSSIBLY EVEN 50S AS WE STAY UNDER SOUTHEAST FLOW
THROUGH THE DAY WITH WINDS OFF THE LAKE IN ILLINOIS. AM CONCERNED
TEMPS ARE STILL A LITTLE HIGH THOUGH FOR MONDAY ALONG THE ILLINOIS
SHORES.
TUESDAY THOUGH SATURDAY...COLD FRONT WILL SWEEP ACROSS THE REGION
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS.
BROAD AREA OF HIGH PRESSURE BUILDS ACROSS THE CANADIAN PRAIRIES EAST
TOWARDS THE GREAT LAKE REGION THROUGH THE END OF THE WEEK. NORTHERN
ILLINOIS AND NORTHWEST INDIANA WILL BE IN AREA OF NORTHERLY FLOW AND
EXPECT TO BE CLIPPED BY COOLER AIR ALOFT //H85 TEMPS FALLING TO
AROUND -3C THURSDAY// BEHIND THE COLD FRONT. SHOULD SEE PLENTY OF
SUNSHINE FOR THE LATTER HALF OF THE WEEK. TEMPERATURES WILL CONTINUE
TO RUN SLIGHTLY ABOVE NORMAL...BUT SHOULD BE MORE SEASONABLE WITH
HIGHS IN THE UPPER 50S TO LOW 60S AND LOWS IN THE UPPER 30S TO LOW
40S. BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* FOG WITH VIS OF 3-5SM THROUGH LATE MORNING...WITH CONDITIONS
IMPROVING BY MID DAY.
* POTENTIAL REMAINING FOR A PERIOD OF MVFR CEILINGS 1500-2000 FT
LATE MORNING TO MID AFTERNOON.
* NORTHEAST WINDS STEADILY INCREASING THROUGHOUT THE DAY...WITH
SOME GUSTS POSSIBLE IN THE AFTERNOON.
RODRIGUEZ
//DISCUSSION...UPDATED 12Z...
EXPECT SOME RATHER VARIABLE CONDITIONS THROUGH EARLY AFTERNOON IN
TERMS OF WINDS/CIGS/VSBY. CURRENTLY...SHRA/TSRA ACTIVITY ACROSS
FAR NE IL IS MOVING INTO NW IN AND WILL EXIT TO THE EAST OF GYY
TOWARD 14Z. NEXT CONCERNS ARE RELATED TO WEAK LOW PRESSURE WHICH
WILL MOVE ALONG A FRONTAL BOUNDARY EXTENDING FROM NEAR KCID TO
KRPJ TO JUST NORTH OF KPWK THIS MORNING. THIS FRONT IS EXPECTED TO
SAG SOUTHWARD THROUGH THE MORNING BRINGING WINDS TO THE NORTHEAST
ACROSS THE CHI AND NW IN TERMINALS...WITH RFD ALREADY SEEING NE
WINDS. AS THE FRONT MOVES WINDS WILL LIKELY BECOME LIGHT AND
VARIABLE WITH A SOUTH TO WEST DIRECTION. GIVEN THE RAINFALL THIS
MORNING AND THE LIGHT WIND REGIME EXPECT THAT MVFR VSBY WILL
PREVAIL...WITH SOME IFR TOWARDS DPA AND RFD...THROUGH AT LEAST MID
MORNING AND POSSIBLY LONGER. IN ADDITION...FORECAST SOUNDINGS
CONTINUE TO SHOW DEVELOPMENT OF MVFR LEVEL STRATUS DECK BY MIDDAY
WHICH WOULD THEN SCATTER LATER THIS AFTERNOON. THIS SEEMS
PLAUSIBLE GIVEN THE SHIFT TO A COOLER NORTHEASTERLY FLOW OFF THE
LAKE AND THE ABUNDANT LOW LEVEL MOISTURE ALREADY IN PLACE. THERE
IS A CHANCE THAT MIST/HAZE WILL CONTINUE THROUGH THE AFTERNOON AS
WELL BUT CONFIDENCE IS LOW.
NORTHEAST WINDS WILL TURN EASTERLY TONIGHT AS RIDGING BUILDS TO
THE EAST AND LOW PRESSURE TAKES SHAPE ACROSS THE CENTRAL PLAINS.
VFR SHOULD PREVAIL BUT SOME MVFR VSBY REDUCTION IS POSSIBLE LATE.
WINDS WILL THEN TURN MORE SOUTHEASTERLY MONDAY MORNING.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM HIGH CONFIDENCE OF FOG/VIS TRENDS WITH MEDIUM CONFIDENCE
OF TIMING IMPROVEMENT.
* LOW MEDIUM CONFIDENCE OF A PERIOD OF 1500-2000 FT CEILINGS LATE
MORNING INTO THIS AFTERNOON.
* HIGH CONFIDENCE IN WIND SPEED AND DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...VFR WITH CHANCE TSRA.
TUESDAY...VFR WITH CHANCE SHRA/TSRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
MDB
&&
.MARINE...
210 AM CDT
HIGH PRESSURE OVER OHIO EXTENDS NORTHEASTWARD ACROSS THE ST.
LAWRENCE VALLEY THIS MORNING WHILE A COMPLEX SERIES OF WEAK LOW
PRESSURE SYSTEMS ARE NOTED FROM LAKE SUPERIOR INTO THE MID
MISSISSIPPI RIVER VALLEY...WITH BETTER ORGANIZED LOW PRESSURE IN THE
LEE OF THE ROCKIES. ONE LOW...OVER LAKE SUPERIOR...WILL MOVE
SOUTHEASTWARD TODAY AND MOVE OFF THE EAST COAST THIS EVENING WHERE
IT WILL DEEPEN. ANOTHER AREA OF LOW PRESSURE OVER WESTERN IOWA
WILL DRIFT EAST WITH A COOL FRONTAL BOUNDARY SETTING UP FROM THE
FIRST LOW INTO THIS WEAKER LOW. HIGH PRESSURE WILL THEN SPREAD
SOUTHWARD FROM HUDSON BAY AND INTO THE GREAT LAKES BEHIND THE
LOW. AS A RESULT OF THIS FAIRLY COMPLEX PATTERN SOUTHERLY WINDS IN
PLACE ACROSS LAKE MICHIGAN THIS MORNING WILL TURN NORTHEASTERLY
TODAY AND EASTERLY TONIGHT...BEFORE BECOMING SOUTHEAST FOR MONDAY.
IT APPEARS THAT THERE WILL BE SEVERAL PERIODS OF STRONGER WINDS
FROM TONIGHT THROUGH TUESDAY AS THE PRESSURE GRADIENT MODULATES
BETWEEN SYSTEMS. THE FIRST INCREASE SHOULD OCCUR TONIGHT ACROSS
CENTRAL AND SOUTHERN PARTS OF THE LAKE WITH GUSTS TO AROUND 25 KT
EXPECTED. SPEEDS LOOK TO EASE SOMEWHAT MONDAY BEFORE INCREASING
AGAIN MONDAY EVENING THEN DROPPING OFF TUESDAY MORNING AS A LOW
PASSES JUST TO THE SOUTH. THE GRADIENT TIGHTENS BEHIND THE LOW
TUESDAY AFTERNOON AS STRONG HIGH PRESSURE SPREADS INTO THE UPPER
MISSISSIPPI RIVER VALLEY. THIS LOOKS TO BE THE PERIOD OF STRONGEST
WINDS WITH 30 KT POSSIBLE FROM THE NORTH. THE HIGH THEN GRADUALLY
SPREADS EASTWARD KEEPING ITS INFLUENCE OVER THE LAKE THROUGH THE
END OF THE WEEK. LOWS WILL PASS TO THE EAST AND SOUTH OF THE LAKE
SO PERIODS OF SLIGHTLY STRONGER WINDS WILL BE POSSIBLE DESPITE THE
PRESENCE OF THE HIGH...BUT HIGHEST SPEEDS LOOK TO BE UNDER 20 KTS
OR SO FROM MID WEEK ONWARD.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
655 AM CDT SUN APR 1 2012
.DISCUSSION...
ISSUED 300 AM CDT SUN APR 1 2012
SMALL MCS FORMED AS EXPECTED OVER EASTERN IOWA LATE IN THE
EVENING...AND HAS BEEN MOVING ACROSS THE NORTHERN CWA
OVERNIGHT...PRODUCING SEVERE HAIL AT TIMES. HAVE SEEN SOME
SHOWERS/STORMS AS FAR SOUTH AS LINCOLN AT 2 AM.
SHORT TERM...TODAY THROUGH TUESDAY...
LATEST HRRR MODEL...WHICH HAS A GOOD HANDLE ON THE ACTIVITY...
SHOWS MUCH OF THE RAIN SHOULD LARGELY BE OUT OF THE CWA BY
SUNRISE. WILL MAKE A LAST MINUTE DECISION ON HOW LONG TO LINGER IT
THIS MORNING. ONCE THAT CLEARS OUT...TEMPERATURES BECOME THE
PRIMARY FOCUS. STILL LOOKING FOR HIGHS IN THE 80S ACROSS THE
ENTIRE AREA...CLOSE TO THE DAILY RECORDS. HOWEVER...EVENING MODEL
RUNS SHOWING A FRONTAL BOUNDARY NEAR THE I-80 CORRIDOR WILL LIKELY
SLIP A BIT SOUTHWARD THIS AFTERNOON...DRIVEN BY A RATHER STIFF
NORTHEAST FLOW. IF IT SLIPS TOO FAR...THEN TEMPERATURES ACROSS THE
NORTHEAST CWA MAY END UP BEING COOLER THAN EXPECTED. WRF MODEL OUT
OF WFO CHICAGO HAS THE BOUNDARY ALMOST ALL THE WAY TO I-74 BY
6 PM. WILL NEED TO WATCH THIS CLOSELY DURING THE AFTERNOON.
BOUNDARY WILL PROBABLY REACH AT LEAST INTO PART OF THE CWA THIS
EVENING...BEFORE BEGINNING TO RETREAT. SAME PROBLEM EXISTS WITH
TEMPERATURES MONDAY AFTERNOON...DUE TO ITS POSITION. HAVE PULLED
HIGH TEMPERATURES DOWN A BIT NORTH OF I-74...BUT STILL GOING A FEW
DEGREES ABOVE GUIDANCE IN THAT AREA. REMAINDER OF THE CWA MORE
LIKELY TO REACH THE 85-90 DEGREE RANGE...AGAIN NEAR THE RECORDS.
TIMING OF COLD FRONTAL PASSAGE TUESDAY MORNING APPEARS TO HAVE
SLOWED A BIT FROM EARLIER RUNS...SO HAVE KEPT TEMPERATURES SOUTH
OF I-70 WARMER THAN PREVIOUSLY FORECAST...WITH LOWER 80S.
THREAT OF SHOWERS/STORMS TO CONTINUE INTO THE AFTERNOON WITH THE
BOUNDARY IN THE AREA.
LONG TERM...WEDNESDAY THROUGH SATURDAY...
STILL LOOKING TO BE MUCH COOLER THAN THE START OF THE WEEK...ALTHOUGH
STILL A BIT ABOVE NORMAL. FOCUS IN THIS PERIOD REMAINS WITH A
CUTOFF LOW WHICH WILL DEVELOP OVER THE SOUTHERN ROCKIES EARLY IN
THE WEEK. LONGER RANGE MODELS IN REASONABLE AGREEMENT WITH A TRACK
THAT TAKES IT SOUTH OF THE OHIO VALLEY...BUT WILL STILL SEE THE
RAIN SHIELD ON THE NORTHERN FLANK EXTEND WELL TO THE NORTH. HAVE
CUT BACK ON THE RAIN ACROSS THE NORTHERN CWA FOR WEDNESDAY/THURSDAY...
WITH THE PERSISTENT NORTHEAST FLOW BRINGING DRIER AIR INTO CENTRAL
ILLINOIS. MAINLY DRY CONDITIONS EXPECTED LATE IN THE WEEK...AS A
NARROW RIDGE OF HIGH PRESSURE MOVES INTO THE MISSISSIPPI VALLEY.
GEELHART
&&
.AVIATION...
ISSUED 655 AM CDT SUN APR 1 2012...FOR THE 12Z TAFS
THE ONLY LINGERING MVFR CONDITIONS ARE IN DEC WITH 5SM BR AT
1145Z. STORMS HAVE MOVE EAST OF CMI...AN NO PRECIP SHOULD AFFECT
ANY OF THE TERMINALS FOR MOST OF THE DAY. ACTUALLY...ALL OUR TERMINALS
SHOULD BE VFR FOR MOST OF THE NEXT 24 HOURS.
FORECAST SOUNDINGS CONFIRM WHAT THE CU RULE IS INDICATING FOR VFR
CLOUD REDEVELOPMENT THIS AFTERNOON. THOSE CLOUDS MAY REDUCE HIGH
TEMPS A LITTLE, BUT IT WILL STILL BE A VERY WARM DAY.
SOME LIGHT MVFR FOG MAY FORM AGAIN LATER TONIGHT...AS A BACK DOOR
COLD FRONT DROPS SOUTH INTO CENTRAL IL FROM NORTHERN IL AND N
INDIANA. THE PRIMARY FOCUS FOR PRECIP WILL BE IN THE EAST...FOR
CMI AND POSSIBLY DEC. WE INTRODUCED A VCSH WITH CB IN CMI AFTER
10Z.
WINDS WILL SHIFT FROM SOUTHEAST EARLY IN THE TAF PERIOD TO
SOUTHWEST BY MID MORNING. WIND SPEEDS MAY REACH UP NEAR 20KT AT
TIMES DURING PEAK MIXING OF LATE MORNING/EARLY AFTERNOON. AS THE
COLD FRONT DROPS INTO C IL TONIGHT...WINDS WILL SHIFT EAST-
SOUTHEAST AGAIN...REMAINING IN THE 10-13KT RANGE FOR MOST TERMINAL
SITES. LIGHT MVFR FOG MAY REDEVELOP LATE TONIGHT...ESPECIALLY FOR
OUR NORTHERN TAFS OF PIA/BMI/CMI. MVFR CLOUDS WILL BE POSSIBLE AS
WELL.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
647 AM CDT SUN APR 1 2012
.DISCUSSION...
315 AM CDT
THIS MORNING HIGH PRESSURE OVER THE EASTERN GREAT LAKES REGION WILL
PUSH EASTWARD WITH FRONTAL BOUNDARY SLOWLY TRYING TO LIFT NORTHWARD
THROUGH THE EARLY MORNING HOURS. ONGOING ELEVATED CONVECTION ON NOSE
OF LOW LEVEL JET WILL CONTINUE TO PUSH SOUTHEAST ACROSS THE REGION
RIDING H5 HEIGHTS DOWN THE RIDGE ALONG THE INSTABILITY GRADIENT.
SEVERE THREAT THROUGH THE PREDAWN HOURS WILL REMAIN MARGINAL...BUT
LATEST RUC CONTINUES TO SHOW NEAR 1000 J/KG GENERALLY ALONG AND WEST
OF THE I39 CORRIDOR SUPPORTING AT LEAST SOME THREAT FOR HAIL. THREAT
SHOULD TAPER THROUGH DAYBREAK THIS MORNING AS LOW LEVEL JET VEERS
AND THETA E ADVECTION WEAKENS. MEANWHILE...WEAK AREA OF LOW
PRESSURE NEAR LAKE SUPERIOR WILL PUSH EAST INTO SOUTHEASTERN
ONTARIO BY EARLY THIS AFTERNOON. GUIDANCE SUGGESTS BAROCLINIC ZONE
WILL BE FARTHER SOUTH/WEST THAN ORIGINALLY ANTICIPATED THUS BUMPED
DOWN TEMPERATURES SLIGHTLY ACROSS THE AREA FOR THIS AFTERNOON. IN
ADDITION WINDS TURNING TO THE NORTHEAST BY MID MORNING IN RESPONSE
TO LOW MOVING ACROSS ONTARIO WILL LIMIT HIGH TEMPS ALONG THE LAKE
SHORE...WITH TEMPERATURES FALLING INLAND THROUGH THE AFTERNOON AS
MARINE LAYER SPREADS INLAND.
MONDAY...GUIDANCE CONTINUES TO STRUGGLE WITH PLACEMENT OF BAROCLINIC
ZONE/LOW PRESSURE. A LARGE TEMPERATURE SPREAD IS STILL EXPECTED TO
SET UP ACROSS THE CWA. MAJORITY OF GUIDANCE SHOWS SOUTHWEST PORTIONS
OF THE CWA TRYING TO REACHING THE 80 MARK...BUT WARMER TEMPERATURES
ARE NOW EXPECTED TO BE FARTHER WEST. ALSO HAD TO DROP TEMPERATURES
ALONG THE LAKE FRONT SEVERAL DEGREES AS LATEST GUIDANCE IN GENERAL
SUGGESTS 60S POSSIBLY EVEN 50S AS WE STAY UNDER SOUTHEAST FLOW
THROUGH THE DAY WITH WINDS OFF THE LAKE IN ILLINOIS. AM CONCERNED
TEMPS ARE STILL A LITTLE HIGH THOUGH FOR MONDAY ALONG THE ILLINOIS
SHORES.
TUESDAY THOUGH SATURDAY...COLD FRONT WILL SWEEP ACROSS THE REGION
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS.
BROAD AREA OF HIGH PRESSURE BUILDS ACROSS THE CANADIAN PRAIRIES EAST
TOWARDS THE GREAT LAKE REGION THROUGH THE END OF THE WEEK. NORTHERN
ILLINOIS AND NORTHWEST INDIANA WILL BE IN AREA OF NORTHERLY FLOW AND
EXPECT TO BE CLIPPED BY COOLER AIR ALOFT //H85 TEMPS FALLING TO
AROUND -3C THURSDAY// BEHIND THE COLD FRONT. SHOULD SEE PLENTY OF
SUNSHINE FOR THE LATTER HALF OF THE WEEK. TEMPERATURES WILL CONTINUE
TO RUN SLIGHTLY ABOVE NORMAL...BUT SHOULD BE MORE SEASONABLE WITH
HIGHS IN THE UPPER 50S TO LOW 60S AND LOWS IN THE UPPER 30S TO LOW
40S. BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* SHRA/TSRA EXITING TO THE EAST 12-13Z.
* FEW-SCT IFR LEVEL CLOUDS POSSIBLE NEXT HOUR OR SO...ESPECIALLY
AT MDW.
* MVFR MIST/HAZE EXPECTED TO CONTINUE THROUGH THE MORNING.
* LIGHT/VARIABLE SOUTH/SOUTHWEST WINDS SHIFTING TO NORTHEAST BY
LATE MORNING/MID-DAY.
* POTENTIAL FOR PERIOD OF MVFR CEILINGS 1500-2000 FT LATE MORNING
TO MID-AFTERNOON.
MDB
//DISCUSSION...UPDATED 12Z...
EXPECT SOME RATHER VARIABLE CONDITIONS THROUGH EARLY AFTERNOON IN
TERMS OF WINDS/CIGS/VSBY. CURRENTLY...SHRA/TSRA ACTIVITY ACROSS
FAR NE IL IS MOVING INTO NW IN AND WILL EXIT TO THE EAST OF GYY
TOWARD 14Z. NEXT CONCERNS ARE RELATED TO WEAK LOW PRESSURE WHICH
WILL MOVE ALONG A FRONTAL BOUNDARY EXTENDING FROM NEAR KCID TO
KRPJ TO JUST NORTH OF KPWK THIS MORNING. THIS FRONT IS EXPECTED TO
SAG SOUTHWARD THROUGH THE MORNING BRINGING WINDS TO THE NORTHEAST
ACROSS THE CHI AND NW IN TERMINALS...WITH RFD ALREADY SEEING NE
WINDS. AS THE FRONT MOVES WINDS WILL LIKELY BECOME LIGHT AND
VARIABLE WITH A SOUTH TO WEST DIRECTION. GIVEN THE RAINFALL THIS
MORNING AND THE LIGHT WIND REGIME EXPECT THAT MVFR VSBY WILL
PREVAIL...WITH SOME IFR TOWARDS DPA AND RFD...THROUGH AT LEAST MID
MORNING AND POSSIBLY LONGER. IN ADDITION...FORECAST SOUNDINGS
CONTINUE TO SHOW DEVELOPMENT OF MVFR LEVEL STRATUS DECK BY MIDDAY
WHICH WOULD THEN SCATTER LATER THIS AFTERNOON. THIS SEEMS
PLAUSIBLE GIVEN THE SHIFT TO A COOLER NORTHEASTERLY FLOW OFF THE
LAKE AND THE ABUNDANT LOW LEVEL MOISTURE ALREADY IN PLACE. THERE
IS A CHANCE THAT MIST/HAZE WILL CONTINUE THROUGH THE AFTERNOON AS
WELL BUT CONFIDENCE IS LOW.
NORTHEAST WINDS WILL TURN EASTERLY TONIGHT AS RIDGING BUILDS TO
THE EAST AND LOW PRESSURE TAKES SHAPE ACROSS THE CENTRAL PLAINS.
VFR SHOULD PREVAIL BUT SOME MVFR VSBY REDUCTION IS POSSIBLE LATE.
WINDS WILL THEN TURN MORE SOUTHEASTERLY MONDAY MORNING.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN SHRA/TSRA ACTIVITY EXITING TO THE EAST 12-13Z.
* MEDIUM-HIGH CONFIDENCE THAN FEW-SCT IFR LEVEL CLOUDS WILL BE
SHORT LIVED THIS MORNING...CANNOT RULE OUT BRIEF BKN COVERAGE
BUT PROBABILITY IS LOW.
* MEDIUM CONFIDENCE IN MVFR MIST/HAZE CONTINUING FOR AT LEAST A
FEW HOURS...LOW CONFIDENCE ON TIMING OF IMPROVEMENT.
* HIGH CONFIDENCE IN WIND TRENDS THROUGH PERIOD AND THAT THERE
WILL LIKELY BE SOME VARIABILITY IN WIND DIRECTION THROUGH MID
MORNING.
* MEDIUM CONFIDENCE IN PERIOD OF 1500-2000 FT CIGS LATE MORNING INTO
THIS AFTERNOON.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...VFR WITH CHANCE TSRA.
TUESDAY...VFR WITH CHANCE SHRA/TSRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
MDB
&&
.MARINE...
210 AM CDT
HIGH PRESSURE OVER OHIO EXTENDS NORTHEASTWARD ACROSS THE ST.
LAWRENCE VALLEY THIS MORNING WHILE A COMPLEX SERIES OF WEAK LOW
PRESSURE SYSTEMS ARE NOTED FROM LAKE SUPERIOR INTO THE MID
MISSISSIPPI RIVER VALLEY...WITH BETTER ORGANIZED LOW PRESSURE IN THE
LEE OF THE ROCKIES. ONE LOW...OVER LAKE SUPERIOR...WILL MOVE
SOUTHEASTWARD TODAY AND MOVE OFF THE EAST COAST THIS EVENING WHERE
IT WILL DEEPEN. ANOTHER AREA OF LOW PRESSURE OVER WESTERN IOWA
WILL DRIFT EAST WITH A COOL FRONTAL BOUNDARY SETTING UP FROM THE
FIRST LOW INTO THIS WEAKER LOW. HIGH PRESSURE WILL THEN SPREAD
SOUTHWARD FROM HUDSON BAY AND INTO THE GREAT LAKES BEHIND THE
LOW. AS A RESULT OF THIS FAIRLY COMPLEX PATTERN SOUTHERLY WINDS IN
PLACE ACROSS LAKE MICHIGAN THIS MORNING WILL TURN NORTHEASTERLY
TODAY AND EASTERLY TONIGHT...BEFORE BECOMING SOUTHEAST FOR MONDAY.
IT APPEARS THAT THERE WILL BE SEVERAL PERIODS OF STRONGER WINDS
FROM TONIGHT THROUGH TUESDAY AS THE PRESSURE GRADIENT MODULATES
BETWEEN SYSTEMS. THE FIRST INCREASE SHOULD OCCUR TONIGHT ACROSS
CENTRAL AND SOUTHERN PARTS OF THE LAKE WITH GUSTS TO AROUND 25 KT
EXPECTED. SPEEDS LOOK TO EASE SOMEWHAT MONDAY BEFORE INCREASING
AGAIN MONDAY EVENING THEN DROPPING OFF TUESDAY MORNING AS A LOW
PASSES JUST TO THE SOUTH. THE GRADIENT TIGHTENS BEHIND THE LOW
TUESDAY AFTERNOON AS STRONG HIGH PRESSURE SPREADS INTO THE UPPER
MISSISSIPPI RIVER VALLEY. THIS LOOKS TO BE THE PERIOD OF STRONGEST
WINDS WITH 30 KT POSSIBLE FROM THE NORTH. THE HIGH THEN GRADUALLY
SPREADS EASTWARD KEEPING ITS INFLUENCE OVER THE LAKE THROUGH THE
END OF THE WEEK. LOWS WILL PASS TO THE EAST AND SOUTH OF THE LAKE
SO PERIODS OF SLIGHTLY STRONGER WINDS WILL BE POSSIBLE DESPITE THE
PRESENCE OF THE HIGH...BUT HIGHEST SPEEDS LOOK TO BE UNDER 20 KTS
OR SO FROM MID WEEK ONWARD.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
611 AM CDT SUN APR 1 2012
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 333 AM CDT SUN APR 1 2012
.SYNOPSIS...
ISSUED AT 333 AM CDT SUN APR 1 2012
THE APRIL 1 2012 00Z 300 HPA SYNOPTIC MAP SHOWED A LARGE ANTICYCLONIC
CURVED JET EXTENDING ACROSS THE WESTERN UNITED STATES AND INTO THE CANADIAN
PRAIRIE PROVINCES. A JET STREAK OF AROUND 130-140 KT WAS OBSERVED FROM
KREV TO KBOI. AT 500 HPA, AN AMPLIFIED TROUGH ASSOCIATED WITH THE JET
STREAK WAS LOCATED ACROSS THE PACIFIC NORTHWEST AND INTO NORTHERN CALIFORNIA.
CONSIDERABLE COLD AIR ADVECTION WITH 500 HPA DELTA TEMPERATURES AROUND
10 DEG C WAS OBSERVED ACROSS THE PACIFIC NORTHWEST ALONG WITH SIGNIFICANT
HEIGHT FALLS. MORE LOCALLY AND AT LOWER LEVELS, A WARM AND DRY PLUME
AT 700 AND 850 HPA PREVAILED ACROSS THE HIGH PLAINS. AT THE SFC, A LOW
PRESSURE CENTER WAS LOCATED ACROSS EASTERN COLORADO. A DRYLINE ASSOCIATED
WITH THIS FEATURE WAS LOCATED ACROSS THE SOUTHERN HIGH PLAINS AS WELL.
THIS MORNING:
AS WITH LAST NIGHT, HAVE FOLLOWED HRRR GUIDANCE IN CONCERNING THE POTENTIAL
FOR PATCHY FOG FORMATION THIS MORNING. THIS MODEL HAS BEEN TRENDING
WELL AS SITES AROUND KANSAS AND OKLAHOMA HAVE BEEN REPORTING BR THROUGH
THE OVERNIGHT HOURS. I DID, HOWEVER, TAKE A MORE CONSERVATIVE APPROACH
AS FAR AS DENSE FOG IS CONCERNED AND STUCK WITH PATCHY RATHER THAN +FG
AS THE WINDS HAVE REMAINED ELEVATED THIS MORNING, WHICH COULD LIMIT
THE OVERALL FOG INTENSITY. RECENT LAMP GUIDANCE AND RUC VIS OUTPUT SEEMS
TO AGREE WITH THIS APPROACH AS WELL. FOG CONCERNS WILL BE OVER BY MID
MORNING IF NOT SOONER.
TODAY:
UNPLEASANTLY WARM TEMPERATURES ARE EXPECTED TODAY. I SAY UNPLEASANT
BECAUSE IT WILL FEEL DOWN RIGHT "HOT" RELATIVE TO THE BEGINNING OF APRIL.
I DID TAKE THE COOLER SIDE OF MOS GUIDANCE AS BOISE VERIFICATION STILL
SHOWS A WARM BIAS FROM THE MODELS. ONE REASON AS SUGGESTED FROM YESTERDAYS
DAY SHIFT IS THAT EVAPOTRANSPIRATION FROM A RECENT HEAVY RAINFALL EVENT
IS SLOWING DOWN HEAT FLUXES. IN ADDITION, DEWPOINTS ARE RUNNING AROUND
60 DEG F THIS MORNING SO THE ATMOSPHERE DOES HAVE SOME MOISTURE WHICH
WILL RETARD SENSIBLE HEATING. THESE DEWPOINTS WILL LOWER AS THE DRYLINE
WILL MIX EAST THROUGH THE AFTERNOON. CONVECTION IS NOT EXPECTED ALONG
THE DRYLINE AS UPPER LEVEL RIDGING CONTINUES AND SUBSIDE PREVAILS AHEAD
OF A WESTERN TROUGH. SOME RECORDS COULD BE IN JEOPARDY TODAY WHICH HAS
BEEN HIGHLIGHTED IN THE CLIMATE SECTION BELOW.
ANOTHER CONCERN FOR TODAY IS WINDS. THE 00Z GFS IS STRONGER WITH 850
HPA WINDS COMPARED TO THE 00Z NAM. THE ATMOSPHERE WILL BECOME WELL MIXED
THIS AFTERNOON IN THE WAKE OF THE DRYLINE, HOWEVER WINDS PER THE MESOSCALE
MODELS ARE NOT THAT IMPRESSIVE AND USING MIX DOWN TECHNIQUES SHOWS THAT
A MARGINAL OR SUB MARGINAL WIND ADVISORY SPEEDS ARE POSSIBLE ACROSS
THE WESTERN AND CENTRAL SECTIONS OF THE CWFA TODAY. AS A RESULT, DID
NOT ISSUE A WIND ADVISORY FOR TODAY.
LASTLY, CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TODAY WHICH IS
ADDRESSED BELOW IN THE FIRE WEATHER SECTION.
TONIGHT:
WINDS WILL GRADUALLY VEER OVERNIGHT AHEAD OF AN APPROACHING SIGNIFICANT
COLD FRONT. TEMPERATURES WILL BE MILD AND GENERALLY IN THE 40S DEG F
WEST TO 50S DEG F EAST. NO PRECIPITATION IS EXPECTED DURING THIS TIME FRAME
AS DYNAMICS WILL NOT ARRIVE UNTIL AS DESCRIBED IN THE LONG TERM SECTION.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 243 AM CDT SUN APR 1 2012
MODELS THIS MORNING REMAIN IN GOOD AGREEMENT WITH QUICKLY MOVING
AN UPPER LEVEL TROUGH WHICH WAS LOCATED JUST OFF THE WEST COAST OF
CALIFORNIA TO NEAR THE FOUR CORNERS REGION BY 06Z MONDAY. THIS
UPPER LEVEL SYSTEM THEN DEEPENS AS IT CROSSES NEW MEXICO DURING
THE DAY ON MONDAY. BY 00Z TUESDAY THE GFS, ECMWF, AND NAM ALL
PLACE THIS UPPER LEVEL LOW NEAR EAST CENTRAL NEW MEXICO. AHEAD OF
THIS DEEPENING UPPER LEVEL SYSTEM A COLD FRONT WILL BE MOVING
SOUTH ACROSS WESTERN KANSAS DURING THE DAY AND BASED ON THE GFS
AND NAM THIS FRONTAL BOUNDARY WILL BE LOCATED NEAR THE OKLAHOMA
BORDER AND SOUTH CENTRAL KANSAS BY 00Z TUESDAY. BOTH MODELS THIS
MORNING ARE IN GOOD AGREEMENT WITH CONVECTION DEVELOPING ALONG
THIS COLD FRONT LATE DAY DESPITE THE DIFFERENCES IN THE LOCATION OF
THIS FRONT MONDAY EVENING. THE CONVECTION LATE DAY DOES APPEAR
REASONABLE GIVEN THE MOISTURE RETURN FORECAST AHEAD OF THIS FRONT,
IMPROVING LOW LEVEL FORCING AND LATE DAY INSTABILITY. AS A RESULT WILL
CONTINUE TO FAVOR KEEPING A MENTION OF LATE DAY STORMS ACROSS
SOUTH CENTRAL KANSAS AFTER 21Z. DECENT MID LEVEL INSTABILITY AT
00Z TUESDAY AND CAPES ARE FORECAST TO BE AT OR ABOVE 2000 J/KG.
MARGINAL SHEAR HOWEVER IS EXPECTED WITH 0-6KM SHEAR AT OR BELOW
30KTS. STILL GIVEN SOME LATE DAY HEATING AND IMPROVING FORCING
ALONG THIS BOUNDARY DO THINK A FEW STORMS THAT DO DEVELOP ALONG
THIS FRONT LATE DAY MAY BECOME SEVERE WITH HAIL UP TO QUARTER SIZE
BEING THE MAIN HAZARD.
NORTH/NORTHWEST OF THIS COLD FRONT LATE MONDAY GUSTY
NORTHERLY WINDS ARE EXPECTED TO INCREASE INTO THE 25 TO 35 MPH
RANGE AS AN AREA OF LOW PRESSURE AT THE SURFACE DEEPENS ALONG THIS
COLD FRONT ACROSS THE PANHANDLE OF TEXAS. THIS WILL BEGIN TO USHER
IN SOME COOLER AIR LATE IN THE DAY SO TEMPERATURES BEHIND THIS
COLD FRONT ARE EXPECTED TO STRUGGLE INTO THE UPPER 60S TO LOWER
70S. AHEAD OF THIS FRONT LOWER 80S STILL APPEAR LIKELY.
THE CHANCES FOR PRECIPITATION THEN SPREADS NORTHWARD ACROSS ALL OF
WESTERN AND MUCH OF NORTH CENTRAL KANSAS MONDAY NIGHT AS THE UPPER
LEVEL LOW BEGINS TO LOWLY MOVE EAST INTO THE PANHANDLE OF TEXAS
AND WARM AIR ADVECTION AND MOISTURE IMPROVES ACROSS WESTERN KANSAS
DURING THE OVERNIGHT HOURS MONDAY NIGHT.
FROM TUESDAY THROUGH EARLY WEDNESDAY A SERIES OF UPPER LEVEL
DISTURBANCES WILL ROTATE AROUND THIS UPPER LOW AS IT MOVES FROM
THE PANHANDLE OF TEXAS INTO SOUTH CENTRAL KANSAS. MOISTURE AND
LIFT (WARM AIR ADVECTION, ISENTROPIC LIFT, 850-700MB
FRONTOGENESIS) CONTINUES SO HAVE THEREFORE RAISE PRECIPITATION
CHANCES ACROSS THE ENTIRE AREA.
BY LATE WEDNESDAY AN UPPER LEVEL SHORT WAVE RIDGE WILL BEGIN TO
BUILD INTO THE ROCKIES AS THE UPPER LOW CONTINUES TO TRACK
EASTWARD ACROSS EASTERN KANSAS. SKIES ARE EXPECTED TO CLEAR FROM
WEST TO EAST AS THE PRECIPITATION ENDS. TEMPERATURES WEDNESDAY
NIGHT HAS THE POTENTIAL TO FALL BACK TO NEAR FREEZING IF SKIES
CLEAR QUICK ENOUGH AND WIND GO LIGHT BUT GIVEN THE TIMING ISSUES
OF THE UPPER LOW HAVE DECIDED TO STAY CLOSE TO LATEST ALLBLEND.
ON THURSDAY AND FRIDAY A WARMING TREND CAN BE EXPECTED ACROSS
WESTERN KANSAS AS THE UPPER LEVEL RIDGE AXIS BUILDS EAST OUT INTO
THE PLAINS AND WESTERLY DOWN SLOPE FLOW IMPROVES
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 608 AM CDT SUN APR 1 2012
AREAS OF LOW IFR STATUS AND PATCHY FOG HAVE BEEN DEVELOPING
ACROSS MUCH OF SOUTHWEST KANSAS EARLIER THIS MORNING. THIS WAS
OCCURRING EAST OF A DRYLINE WHICH WAS LOCATED NEAR THE COLORADO
BORDER. THE NAM/RUC WERE IN GOOD AGREEMENT WITH THE DRYLINE QUICKLY
MOVING EAST TODAY. WHAT STATUS/FOG THAT WILL DEVELOP BETWEEN 12Z AND
14Z AT DDC AND GCK WILL QUICKLY ERODE AS A DRIER SOUTHWEST WIND
DEVELOPS. THESE SOUTHWEST WINDS WILL THEN INCREASE THROUGH THE DAY
INTO THE 15 TO 25 KNOT RANGE. AFTER SUNSET...WINDS WILL DECREASE
BACK INTO THE 10-15 KNOT RANGE AND BACK MORE TO THE SOUTH.
&&
.FIRE WEATHER...
ISSUED AT 333 AM CDT SUN APR 1 2012
AFTER COORDINATION WITH SURROUNDING WFO`S, HAVE CONTINUED THE RFW TODAY
AND ADDED CLARK COUNTY IN. THE EASTERN COLUMN OF COUNTIES IS A BIT MARGINAL
AS RH`S WILL BE IN THE 15 TO 17 PERCENT RANGE. DECIDED TO ERROR ON THE
SIDE OF CAUTION AND KEEP THE COUNTIES IN THE WARNING AS TODAYS HIGHS
WILL BE VERY WARM AND THE MODELS TYPICALLY UNDER FORECAST DEWPOINTS
IN ASSOCIATION WITH A MIXING DRYLINE AND ADIABATIC COMPRESSIONAL WARMING.
&&
.CLIMATE...
ISSUED AT 333 AM CDT SUN APR 1 2012
A VERY ANOMALOUS DAY OF EXTREMELY WARM TEMPERATURES IS EXPECTED TODAY.
POSITIVE TEMPERATURE DEVIATIONS OF 20 TO 30 DEGREES IS LIKELY ACROSS
SOUTHWEST AND SOUTH CENTRAL KANSAS. SOME RECORDS COULD BE BROKEN TODAY.
CLIMATE RECORDS IS AS FOLLOWS:
RECORD (YEAR)..........................FORECAST HIGH FOR TODAY
DODGE CITY: 88 (1940, 1964)............89
MEDICINE LODGE: 93 (1946)..............86
GARDEN CITY: 87 (1964).................90
ELKHART 89 (1946)......................90
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 89 52 71 41 / 0 10 10 60
GCK 90 50 68 40 / 0 10 10 60
EHA 90 49 63 38 / 0 10 20 50
LBL 90 50 68 40 / 0 10 20 60
HYS 88 54 70 41 / 0 10 10 50
P28 86 57 79 51 / 0 10 40 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON CDT /11 AM MDT/ TODAY TO 9 PM CDT /8
PM MDT/ THIS EVENING FOR KSZ030-043>045-061>064-074>078-084>088.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1149 AM EDT SUN APR 1 2012
.SYNOPSIS...
A COLD FRONT MOVING SOUTHEASTWARD THROUGH THE UPPER OHIO VALLEY
THIS AFTERNOON AND EVENING WILL PROVIDE SHOWERS WITH SCATTERED
THUNDERSTORMS ACROSS OHIO AND WEST VIRGINIA. CANADIAN HIGH
PRESSURE WILL PROVIDE A DRY BREAK MONDAY BEFORE THE FRONT RETURNS
AS A WARM FRONT WITH SCATTERED SHOWERS AND THUNDERSTORMS TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
RECENT SATELLITE DATA SHOWS CLOUDS HAVE DECREASED FOR THE MIDDAY,
BUT BLEND OF RECENT HRRR AND NAM MODEL OUTPUT SHOW CLOUDS WILL
INCREASE THIS AFTERNOON AND SHOWERS WILL START TO DEVELOP NEAR A
SOUTHEAST MOVING COLD FRONT ACROSS NORTHWEST PENNSYLVANIA AND A
NEAR STATIONARY WARM FRONT POSITIONED JUST SOUTH OF THE I-70.
RECENT HRRR AND NAM MODEL OUTPUT THEN SHOW THE COLD FRONTAL BAND
OF SHOWERS, WITH SCATTERED THUNDERSTORMS OVER OHIO AND NORTHERN
WEST VIRGINIA, WILL CONTINUE TO MOVE SOUTHEASTWARD ACROSS THE
UPPER OHIO VALLEY INTO EVENING, EXITING THE REGION BY ABOUT
MIDNIGHT.
CLOUDS WILL LIKEWISE DECREASE, NORTH TO SOUTH, AS CANADIAN HIGH
PRESSURE PROVIDES SUBSIDENCE AND SURFACE LAYER DRYING.
ADJUSTED TEMPERATURE FORECAST TOWARD SLIGHTLY COOLER VALUES USING BLEND
OF HRRR, SREF, GFS, AND NAM MODEL OUTPUT.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
MONDAY WEATHER LOOKS DRY WITH MODELS IN AGREEMENT IN DEPICTIONS
OF DRY SURFACE HIGH SLIDING OVER THE UPPER OHIO REGION AS RIDGE
ALOFT AMPLIFIES OVER THE WESTERN GREAT LAKES.
COOL NORTH TO NORTHEAST WIND SHOULD LIMIT TEMPERATURE RECOVERY
DESPITE SUNSHINE. READINGS WERE FORECAST USING SREF WITH AN
APPROXIMATE 10 DEGREE SPREAD FM NR DUBOIS TO ZANESVILLE AS REGION
WL BE UNDER BAROCLINIC ZONE TO THE EAST OF THE RIDGE AXIS.
THAT BAROCLINIC ZONE/FRONTAL BOUNDARY WILL BE THE FOCUS FOR SHOWER
AND THUNDERSTORM DEVELOPMENT LATE MONDAY NIGHT AND TUESDAY AS
SHORTWAVE CROSSES THE LAKES AND ERODES THE RIDGE. TEMPERATURES WL
MODERATE IN THE WARM ADVECTION ON THE VAN OF THAT SYSTEM.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
IN GENERAL...NORTHWEST FLOW PATTERN ACROSS THE GREAT LAKES REGION
IS PROJECTED TO CONTINUE FOR THE SECOND HALF OF THE WEEK. TEMPERATURES
WL THUS BE WITHIN A FEW DEGREES OF THE SEASONAL AVERAGES. HAVE
PERSISTED WITH SUB CLIMO POPS...BUT CHANGES SHOULD BE ANTICIPATED
AS EVENTUAL WEATHER WL BE SHORTWAVE DEPENDENT.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
LAST OF THE MVFR STRATOCUMULUS CEILINGS SHOULD EITHER DISSIPATE OR
LIFT TO VFR LEVELS BY 17Z.
SOUTHEASTWARD MOVING COLD FRONTAL BAND OF MVFR SHOWERS WILL MOVE
FROM THE I-80 CORRIDOR AROUND 20Z TO SOUTH OF THE I-70 CORRIDOR BY
00Z.
RAIN SHOWERS WILL END FROM NORTH TO SOUTH AS THE FRONT EXITS, BUT
LOWER CLOUDS WILL MOVE BACK IN WITH THE CAA. EXPECT GENERAL MVFR
RESTRICTIONS AT ALL PORTS, WITH THE EXCEPTION OF ZZV FOR THE LATE
EVENING HOURS, THEN POSSIBLE IFR RESTRICTIONS BY LATE SUNDAY NIGHT,
EARLY MONDAY MORNING.
OUTLOOK...MONDAY THROUGH WEDNESDAY...MONDAY WILL BEGIN WITH IFR/MVFR
CLOUDS WITH THE EXCEPTION OF ZZV THEN A RAPID IMPROVEMENT TO VFR
CONDITIONS AS HIGH PRESSURE BUILDS IN. THE NEXT LOW PRESSURE SYSTEM
WILL BRING RESTRICTIONS LATE TUESDAY AFT AND TUESDAY NIGHT, WITH A
RETURN TO VFR LATER WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
725 AM CDT SUN APR 1 2012
.DISCUSSION...WILL CANCEL THE NORTHERN PORTION OF THE DENSE FOG
ADVISORY SINCE THE LOW CLOUDS AND FOG NEVER ADVECTED THAT FAR
NORTH. THE OPPORTUNITY FOR DENSE FOG ACROSS THIS AREA IS NOW
MINIMAL CONSIDERING SUNRISE HAS OCCURRED. MUCH OF THE REMAINDER OF
THE ADVISORY STILL HAS DENSE FOG.
&&
.AVIATION...LIFR/IFR CIGS/VSBY WILL CONTINUE TO AFFECT KBJI INTO
THE MID MORNING HOURS. THIS IS STILL A CHANCE THESE CONDITIONS
WILL AFFECT FARGO. KTVF/KGFK/KDVL APPEAR THAT THEY WILL BE VFR THE
REMAINDER OF THE DAY. GUSTY SOUTHEAST WINDS EXPECTED TO DEVELOP
BY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 350 AM CDT SUN APR 1 2012/
DISCUSSION...THE DENSE FOG IS BECOMING MORE WIDESPREAD AND
ADVECTING TO THE NORTH AND WEST ACCORDING TO WEB CAMS AND
OBSERVATIONS. THE HRRR IS DOING AN EXCELLENT JOB WITH THIS
FOG...AND WILL FOLLOW FOR THE FORECAST. ISSUED A DENSE FOG
ADVISORY FOR AREAS ALONG AND SOUTH OF A VALLEY CITY TO GRAND FORKS
TO BAUDETTE LINE. RADAR SHOWS SHOWERS NEAR THE INTERNATIONAL
BORDER...AND THESE WILL BE NORTH OF THE DENSE FOG AREA. FAIRLY
CONFIDENT THAT THE DENSE FOG WILL BE ABLE TO ADVECT INTO THE
VALLEY CITY...FARGO...AND GRAND FORKS AREAS.
PREV DISCUSSION... /ISSUED 310 AM CDT SUN APR 1 2012/
SHORT TERM (SUN-TUE)...INTERESTING FORECAST WITH MULTIPLE
CHALLENGES. MODEL DIFFERENCES ARISE ON MONDAY WITH TIMING OF
FRONT. GEM/ECMWF SLOW WHILE NAM/GFS QUICKER. ECMWF HAS BEEN
CONSISTENT WITH THE SLOW SOLUTION...BUT HAD BEEN AN OUTLIER UNTIL
THIS SET OF MODEL RUNS WITH THE GEM TRENDING SLOWER. WILL HAVE TO
FOLLOW A BLEND.
UPPER RIDGE BUILDING INTO THE REGION FOR TODAY. AHEAD OF THIS
UPPER RIDGING...SCATTERED SHOWERS ASSOCIATED WITH WEAK WAVE (WARM
AIR ADVECTION) POSSIBLE DURING THE EARLY MORNING HOURS...EXITING
THE NE FA BY NOON. LOW-LEVEL FLOW IS INCREASING FROM THE
SOUTHEAST...AND ADVECTING LOW LEVEL MOISTURE (LOW CLOUDS/FOG) BACK
INTO THE REGION FROM CENTRAL MINNESOTA. FOLLOWING HRRR...EXPECT
THESE CIGS TO ADVECT INTO ALL BUT THE FAR NORTHERN FA BY
12Z...THEN SCATTER WITH DAYTIME HEATING AND STRONG SE WINDS BY
MID TO LATE MORNING. DENSE FOG POSSIBLE UNTIL MID-MORNING...AND
WILL MONITOR CONDITIONS FOR POSSIBLE ADVISORY. SO FAR DENSE FOG
IS NOT TOO WIDESPREAD...BUT HRRR SUGGESTS THAT DENSE FOG WILL
BECOME WIDESPREAD BY 05Z. WINDS WILL BE CLOSE TO ADVISORY CRITERIA
THIS AFTERNOON...BUT PARAMETERS SUGGEST JUST BELOW. WITH SOLAR AND
GOOD MIXING...EXPECT FULL HEATING POTENTIAL...WITH MAX TEMPS
AROUND 80F ACROSS THE SW FA TO UPPER 60S ACROSS THE NE FA.
EXPECTED TEMP VALUES ALONG AND WEST OF THE VALLEY WILL BE RECORD
HIGHS.
UPPER RIDGING WILL BE BRIEF WITH UPPER FLOW BECOMING SOUTHWEST
TONIGHT. STRONG 850MB JET WILL DEVELOP AND TRANSPORT MOISTURE
ALONG AND AHEAD COLD FRONT. FOLLOWING MODEL COMPROMISE FOR
TIMING...BEST PRECIP CHANCES WILL BE ALONG AND EAST OF THE
VALLEY...FROM 06Z MON INTO THE AFTERNOON HOURS. 850MB CAPE
1000-1500 J/KG INTO THE EARLY MORNING ALONG WITH STRONG LOW-LEVEL
JET ACROSS SE FA COULD LEAD TO ISOLD SEVERE HAIL (SPC HAS A 5%
PROBABILITY)...ALTHOUGH DEEP LAYER SHEAR WILL BE MARGINAL. UPPER
TROUGH SWINGS THROUGH BY MON NIGHT. AS THIS FEATURE APPROACHES
CANNOT RULE OUT SHOWERS ANYWHERE ON MONDAY...BUT HEAVIEST RAINFALL
SHOULD BE IN MINNESOTA COUNTIES (AHEAD OF COLD FRONT WHERE PWATS
ARE HIGHEST). CLOUDS AND COOLER AIRMASS WILL LEAD TO MUCH COLDER
TEMPS ON MONDAY (ALTHOUGH STILL ABOVE NORMAL).
RIDGING MOVES BACK INTO THE REGION ON TUESDAY...AND TEMPS BEGIN TO
TREND WARMER AGAIN.
LONG TERM (WED-SAT)...RIDGING DOMINATES INTO FRIDAY BEFORE MOVING
TO THE EAST ALLOWING SW FLOW ALOFT. DRY AND WARM CONDITIONS SHOULD
TRANSITION TO COOLER AND WETTER BY SATURDAY IF MODELS HAVE TIMING
CORRECT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR NDZ038-039-
049-052-053.
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ003-016-
017-023-024-027>032-040.
&&
$$
TG
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1040 AM EDT SUN APR 1 2012
.SYNOPSIS...
A FRONTAL BOUNDARY WILL DROP SOUTH INTO THE OHIO VALLEY TODAY
OFFERING ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS. THIS FRONT
WILL PUSH INTO THE TENNESSEE VALLEY WITH SURFACE HIGH PRESSURE
PROVIDING A TEMPORARY DRY PERIOD ON MONDAY. THIS FRONT IS EXPECTED
TO RETURN BRINGING ADDITIONAL THUNDERSTORMS MONDAY NIGHT INTO
TUESDAY.
&&
.NEAR TERM /UNTIL 9 PM THIS EVENING/...
DECAYING MCS WILL BRING A CHANCE FOR SHOWERS MAINLY WEST OF I-75
THROUGH THE LATE MORNING. GRADUAL CLEARING BEHIND THIS
FEATURE...COMBINED WITH AMPLE WARM/MOISTURE ADVECTION FROM THE
SOUTHWEST ASSOCIATED WITH A WARM FRONT WILL LEAD TO TEMPERATURES
INTO THE LOW TO MID 70S ACROSS THE MAJORITY OF THE AREA BY LATE
THIS AFTERNOON.
NORTHWESTERLY FLOW ALOFT WILL INTENSIFY LATER TODAY AROUND THE
PERIPHERY A MID/UPPER LEVEL RIDGE BUILDING ACROSS THE PLAINS. AT
THE SAME TIME...A SHORTWAVE TROUGH WILL DROP ACROSS THE EASTERN
GREAT LAKES. THIS SHORTWAVE WILL DEVELOP A BACK DOOR COLD FRONT
WHICH WILL PUSH TOWARD THE OHIO VALLEY THIS EVENING. AHEAD OF THIS
FRONT...AN INCREASINGLY UNSTABLE BOUNDARY LAYER WILL COMBINE WITH
DEEP SHEAR TO DEVELOP THUNDERSTORMS ACROSS OUR AREA LATE THIS
AFTERNOON AND INTO THE EVENING. SOME OF THESE STORMS HAVE THE
POTENTIAL TO BECOME SEVERE. THE MAIN THREAT FROM THESE STORMS WILL
BE LARGE HAIL AND DAMAGING WINDS. HOWEVER...CANNOT RULE OUT AN
ISOLATED TORNADO...PARTICULARLY IF STORMS INTERACT WITH OTHER
OUTFLOW BOUNDARIES. OVERALL...CONVECTION WILL INITIATE ACROSS THE
NORTH LATE THIS AFTERNOON...AND PUSH SSE ACROSS OUR SOUTH THIS
EVENING WITH THE MEAN FLOW.
HAVE FAVORED THE 12Z RUC FOR THIS UPDATE FOR TEMPS AND STORM
TIMING.
&&
.SHORT TERM /9 PM THIS EVENING THROUGH TUESDAY/...
A BACK DOOR TYPE COLD FRONT TO DROP SOUTH THRU THE OHIO VALLEY
AND STALL OUT OVER THE TN VLY OVERNIGHT. WL BUMP POPS UP TO LKLY
EARLY ACRS THE SE WHERE BEST FORCING WL EXIST AND THEN TAPER
PRECIP OFF FROM NORTH TO SOUTH. SOME OF THE STORMS MAY BE SEVERE
DURING INTO THE EARLY EVENING HOURS WITH THE MAIN THREATS BEING
WIND AND HAIL.
SFC HIGH PRESSURE WILL BRIEFLY BUILD INTO THE FA MONDAY PROVIDING
A TEMPORARY DRY PERIOD. HAVE TRENDED MONDAYS HIGHS A LTL COOLER ON
MONDAY...FROM THE MID 60S NE TO THE MID/UPR 70S SOUTHWEST. THE MID
LEVEL RIDGE WL BUILD E INTO THE REGION WITH UPPER LEVEL DISTURBANCE
PASSING THRU THE GREAT LAKES TUESDAY. ASSOCIATED SFC WAVE TO TRACK THRU
THE SRN GREAT LAKES. FRONT BOUNDARY TO PIVOT BACK NORTHEAST AS A
WARM FRONT LATE MON NIGHT/TUE AND THEN COLD FRONT TO DROP BACK DOWN
THRU THE OHIO VALLEY TUES NIGHT. NUMERICAL MODELS ARE NOT IN
AGREEMENT REGARDING THIS SYSTEM AND HOW ACTIVE THE INITIAL WARM FRONT
WL BE LATE MONDAY NIGHT/TUES. HAVE CHANCE/SLIGHT POPS RE-DEVELOPING
LATE WITH THE BEST PROBABILITY ACRS W CENTRAL OHIO. THEN ALLOW CHC
POPS TO LAY OUT E-W ON TUESDAY WITH THE APPROACH OF FRONT.
CONFIDENCE IS NOT HIGH REGARDING PRECIP CHANCES TUESDAY. ETA/GFS SOLNS
ARE FASTER BRINGING THE FRONT IN...WHICH THE ECMWF HOLDS IT BACK.
GOING WITH A SLIGHTLY SLOWER SOLN HAVE WARM TEMPS WITH TUESDAYS
FCST HIGHS RANGING FROM THE LOWER 70S FAR N TO AROUND 80 SOUTH.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HAVE FAVORED NON-GFS SOLUTION EARLY ON. THIS WOULD LEAD TO A SLOWER
PROGRESSION OF A FRONT AND ASSOCIATED PRECIPITATION. HOWEVER THERE
COULD BE SOME ELEVATED SHOWERS AND THUNDERSTORMS TUESDAY MORNING
WELL AHEAD OF THE FRONT. BUT MOST STORMS SHOULD HOLD OFF UNTIL LATE
TUESDAY AFTERNOON INTO TUESDAY NIGHT AS THE FRONT MOVES THROUGH.
THIS BOUNDARY WILL STALL IN THE TENNESSEE VALLEY AS HIGH PRESSURE
BUILDS ACROSS THE GREAT LAKES ON WEDNESDAY.
A CLOSED LOW WILL PASS SOUTH OF THE REGION ON THURSDAY AND THURSDAY
NIGHT WHICH MAY SPREAD SHOWERS AND THUNDERSTORMS BACK INTO THE
SOUTHERN ZONES. AFTER THIS PASSES HIGH PRESSURE WILL BE ABLE TO
BUILD SOUTH OVER THE REGION FOR THE END OF THE WEEK.
ABOVE NORMAL TEMPERATURES AT THE BEGINNING OF THE PERIOD WILL TREND
TOWARDS NORMAL BY LATER IN THE WEEK.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
WITH HIGH PRESSURE MOVING EAST...CONVECTION WILL ENTER THE
REGION FROM THE WEST AS A WARM FRONTAL ZONE SETS UP THIS MORNING.
THUNDERSTORMS OCCURRING OVER INDIANA WILL MOVE TO ILN TAF SITES
STARTING AT 12Z. CONVECTION WITH MVFR MAY DIMINISH LATE THIS
MORNING BEFORE REDEVELOPING IN THE AFTERNOON TO EARLY EVENING.
WINDS WILL GUST OVER 20 KNOTS OUT OF THE SOUTHWEST DURING THE
AFTERNOON AS THE PRESSURE GRADIENT TIGHTENS ALONG THE FRONT. WINDS
WILL SHIFT TO NORTHWEST IN THE EVENING AS THE WARM FRONT
TRANSITIONS TO A BACK DOOR COLD FRONT...BRINGING DRIER AIR AND AN
END TO THE CONVECTION.
OUTLOOK...SCATTERED THUNDERSTORMS POSSIBLE MONDAY INTO TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...AR
NEAR TERM...LATTO
SHORT TERM...AR
LONG TERM...
AVIATION...CONIGLIO
AREA FORECAST DISCUSSION
NWS SPOKANE WA
855 AM PDT Sun Apr 1 2012
.SYNOPSIS...
A low pressure system will bring rain, mountain snow and gusty winds
to the Inland Northwest today. Snow levels will be around 3000 feet
today which is a lower elevation than the last few days. The cooler
air mass will slow the rate of mountain snow melt, which should
decrease runoff into the rivers of north Idaho. Many swollen rivers
will begin to recede today. The Inland Northwest will experience a
break Monday and Tuesday however cool and unsettled weather will
return late Tuesday and linger through the upcoming weekend.
&&
.DISCUSSION...
Another quick update to the forecast. Intense snow shower
producing some brief accumulations this morning in the metro area.
But it is quickly fading on radar and moving east, so this won`t
last long. As this last wave moves into the Panhandle showers will
continue there all day.
Tougher call is what will happen behind this wave this afternoon.
On the one hand the models show dry air moving in and this is
confirmed by the dropping dew points at Wenatchee, Ellensburg, and
Yakima. This dry air will move east into the Spokane/Pullman area
this afternoon. So that will be working against afternoon showers.
The flip side is climatology and the NAM model. Typically with
this set up we will see afternoon showers, although they might
not produce measurable precipitation. NAM wants to do this. The
last run of the HRRR (10Z) doesn`t have as much coverage but it
did show the typical convergence lines of showers. So have kept in
the mention of showers this afternoon/evening. These could be rain
or snow with no accumulation.
Last item to address is the Wind Advisory. Winds are picking up in
southeast Washington and this will spread northward by mid day.
The problem is that the guidance is all consistent in suggesting
that winds will actually subside a bit late this afternoon, during
peak heating time. This typically isn`t good for strong winds so
the Advisory may have a tough time verifying in some locations.
Will stick with it since it will still be windy, maybe just not as
strong as previously thought. RJ
&&
.AVIATION...
12z TAFS: Rain and snow showers will be widespread through 18z over
the Idaho Panhandle and far eastern Washington including the Spokane
area. Ceilings of 2000 feet or lower will likely accompany the
heaviest precipitation between 14z-17z. Ceilings will likely lift
quickly by late morning as gusty post-frontal winds develop from
Wenatchee to Spokane to Pullman. Gusts in the 30-35kt range will be
possible through 22z-24z. Winds should subside early in the evening
as the surface gradient between low pressure over Montana and high
pressure over Oregon weakens. /GKoch
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 44 31 52 38 61 39 / 100 20 10 10 10 60
Coeur d`Alene 43 31 50 35 61 38 / 100 30 10 10 10 70
Pullman 43 31 53 37 61 35 / 90 20 0 0 10 70
Lewiston 49 34 60 41 66 40 / 60 10 0 0 10 60
Colville 48 31 51 36 62 37 / 100 20 30 20 40 60
Sandpoint 42 30 47 34 58 38 / 100 40 20 10 10 70
Kellogg 38 31 46 33 58 36 / 100 40 20 10 10 80
Moses Lake 55 33 58 42 64 39 / 10 10 10 10 30 50
Wenatchee 51 36 56 42 58 35 / 10 10 10 10 50 40
Omak 51 31 55 39 58 35 / 20 10 20 40 60 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Wind Advisory until 5 PM PDT this afternoon for Idaho Palouse.
WA...Wind Advisory until 5 PM PDT this afternoon for Lower Garfield
and Asotin Counties-Moses Lake Area-Upper Columbia Basin-
Washington Palouse-Waterville Plateau-Wenatchee Area.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
636 AM CDT SUN APR 1 2012
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
325 AM CDT SUN APR 1 2012
MAIN FORECAST CONCERNS ARE ON STRATUS TRENDS TODAY...AS WELL AS
PRECIPITATION CHANCES TONIGHT THROUGH MONDAY NIGHT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED DEEP TROUGHING ALONG THE WEST COAST OF THE U.S....BUILDING
RIDGING DOWNSTREAM ACROSS THE PLAINS INTO MANITOBA...AND TROUGHING
OVER SOUTHEAST CANADA. WITHIN THIS LATTER TROUGHING...A STRONG
SHORTWAVE WAS DROPPING SOUTHEAST THROUGH NORTHERN ONTARIO. WITH THE
BUILDING RIDGING/HEIGHTS AT 500MB TAKING PLACE NEAR AND WEST OF THE
FORECAST AREA...A WARM ADVECTION PATTERN IS IN PLACE. SOUNDINGS AT
GRB AND MPX REFLECT THIS...SHOWING 850MB TEMPS THAT ROSE TO 9C AT
15C RESPECTIVELY AT 00Z...COMPARED TO -2C AND 9C AT 12Z YESTERDAY.
THE WARM ADVECTION OCCURRING ALOFT WAS A PROBLEM GETTING RID OF THE
STRATUS DURING THE DAY YESTERDAY...PLUS THE DEPTH OF THE STRATUS AT
12Z WAS 75MB...BOTH MAKING IT TOUGHER TO MIX OUT. DURING THE
EVENING...INCREASING 925MB WINDS OF 30-40KT HELPED TO BRING DRIER
AIR BELOW 900MB SEEN ON THE 00Z DVN SOUNDING NORTHWARD...WHICH HAS
CLEARED OUT THE LOW CLOUDS UP TO A FARIBAULT MN TO OSHKOSH WI
LINE. SEEING SOME FOG DEVELOP IN THE CLEARING AREA. ACROSS
NORTHERN WISCONSIN...925MB WINDS HAVE TURNED NORTHWEST...IN THE
WAKE OF A COLD FRONT ABOVE THE SURFACE ASSOCIATED WITH THAT
NORTHERN ONTARIO SHORTWAVE. BACK FARTHER TO THE SOUTH...CONVECTION
ROLLED EAST ACROSS FAR SOUTHERN WISCONSIN...EASTERN IOWA INTO
NORTHERN ILLINOIS OVERNIGHT...ON THE NOSE OF A LOW LEVEL JET AND
SURFACE WARM FRONT WHICH SITS NOW NEAR I-80.
TODAY AND TONIGHT...UPPER RIDGING SEEN BUILDING OVER THE PLAINS WILL
SHIFT EAST THROUGH TONIGHT WITH THE AXIS RIGHT OVER THE FORECAST
AREA AT 12Z. WITH THE UPPER FLOW GAINING A LITTLE MORE
AMPLITUDE...THAT COLD FRONT SEEN IN 925MB PROFILER/VWP DATA LOOKS TO
DROP SOUTH THROUGH MUCH OF THE FORECAST AREA BETWEEN 12-18Z. THE
FRONT THEN STALLS OUT FOR THE AFTERNOON FROM SOUTHWEST MINNESOTA
INTO NORTHERN ILLINOIS. WITH THE 925MB WINDS VEERING NORTHEASTERLY
THEN SOUTHEASTERLY BEHIND THIS FRONT...THE STRATUS WILL MAKE ITS WAY
BACK SOUTH ACROSS WISCONSIN PORTIONS OF THE FORECAST AREA. QUESTION
THEN BECOMES FOR THE AFTERNOON...DOES THE STRATUS MIX OUT? FOR
YESTERDAY...THE 31.00Z NAM AND 31.00-07Z RUC MODELS...AS WELL AS THE
HRRR...WERE ALL SAYING THE STRATUS WOULD MIX OUT BY 19Z. SEEING THE
SAME THING FROM THESE MODELS TODAY. ONE ADVANTAGE TO CLEARING IS
THAT DRIER AIR IS LOWER IN THE ATMOSPHERE COMPARED TO THIS TIME
YESTERDAY...NOTED BETWEEN THE 12Z AND 00Z GRB SOUNDING. THIS DRIER
AIR LOOKS TO CONTINUE TO SINK TOWARDS THE SURFACE TODAY WHILE MIXING
OCCURS. THE COMBINATION OF THE TWO SHOULD BE ABLE TO SCOUR OUT THE
STRATUS. WITH THE STRATUS CONCERNS...HAVE LOWERED TEMPERATURES
CLOSER TO THE NAM12 AND REGIONAL CANADIAN 2 METER OUTPUT...WHICH
SEEMS REASONABLE. CERTAINLY IF CLOUDS STICK AROUND LONGER LIKE
YESTERDAY...THESE STILL MAY BE TOO HIGH. HOWEVER...DO NOT WANT TO
DROP TOO MUCH GIVEN ANY SUN AND 850MB TEMPS OF 12-16C COULD EASILY
JUMP TEMPERATURES WELL INTO THE 70S. TONIGHT...THE LINGERING
MOISTURE COULD REDEVELOP OR EXPAND INTO A STRATUS DECK WEST OF THE
MISSISSIPPI RIVER AS THE 925MB WINDS INCREASE OUT OF THE SOUTHEAST.
THE INCREASING WINDS ARE IN RESPONSE TO DEEPENING LOW PRESSURE OVER
NEBRASKA WITH AN INVERTED TROUGH EXTENDING NORTHEAST THROUGH WESTERN
MINNESOTA. SHOULD SEE A SURGE OF ISENTROPIC LIFT WITH THIS SYSTEM AS
WELL...WHICH SHOWS UP WELL ON 305K SURFACES IN THE 06-12Z MONDAY
TIME PERIOD FROM LA CROSSE SOUTHWESTWARD. SOUNDINGS CONTINUE TO
SUGGEST A CAPPING INVERSION AT 750MB TO PREVENT ACCAS THAT DEVELOPS
FROM THE LIFT INTO BECOMING DEEP CONVECTION. WILL CONTINUE THE DRY
FORECAST...BUT MONITORING OF THIS CAP IS NEEDED. FURTHER NORTH...
MODELS WERE SUGGESTING BEFORE CONVECTION POSSIBLY INTO TAYLOR
COUNTY. THIS IS NOW PROGGED TO STAY WELL OFF TO THE NORTHWEST...UP
NEAR DULUTH. THEREFORE HAVE PULLED THE 20 PERCENT CHANCES.
MONDAY THROUGH TUESDAY NIGHT...THE UPPER RIDGE OVER THE FORECAST
AREA IS PROGGED TO SLOWLY FALL APART...IN RESPONSE TO THE NORTHERN
PORTION OF THE CURRENT WESTERN TROUGH CROSSING FROM THE NORTHERN
PLAINS THROUGH THE WESTERN GREAT LAKES. THE TIMING OF THE NORTHERN
FEATURE CONTINUES TO BE A PROBLEM...WITH THE ECMWF/UKMET/CANADIAN
CONSISTENTLY REMAINING SLOWER THAN THE NAM/GFS. THIS HAS SIGNIFICANT
IMPLICATIONS ON TEMPERATURES AND ANY PRECIP TIMING. TRENDS IN THE
NAM/GFS SINCE THE 31.00Z RUNS HAVE SHOWN SOME SLOWING...THEREFORE
HAVE BIASED THE FORECAST TOWARDS THE SLOWER ECMWF/UKMET/CANADIAN.
ALL MODELS ARE SUGGESTING A DRIER FORECAST MONDAY...ESPECIALLY
DURING THE MORNING...AS ALL SYNOPTIC FORCING IS EITHER ACROSS
NORTHERN MINNESOTA OR BACK IN THE FRONTOGENETIC AREA BEHIND THE
INVERTED TROUGH CROSSING MINNESOTA. HAVE REDUCED PRECIPITATION
CHANCES SOME FOR MONDAY AND LATER FORECASTS MAY BE ABLE TO
COMPLETELY DRY IT OUT. WITH THE TRACK OF THE UPPER TROUGH...BEST
DPVA FORCING SHOULD CONTINUE TO STAY MORE TOWARDS THE NORTH FOR
MONDAY NIGHT. AS SUCH...WHEN YOU LOOK AT MODEL QPF FIELDS...MOST OF
THE QPF ENDS UP NORTH OF I-94. PLUS...500MB HEIGHT FALLS ARE ONLY
10-20 METERS TOPS FROM I-90 SOUTH. THEREFORE...REDUCED MONDAY
NIGHTS CHANCES ABOUT 10 PERCENT SOUTH OF I-90 AND KEPT 50 CHANCES
GOING NORTH OF I-94. SPC CONTINUES TO SHOW A 5% CHANCE OF SEVERE
WEATHER FOR MONDAY AND MONDAY NIGHT...BUT CONFIDENCE IS REALLY LOW
WITH PRECIPITATION IN THE FIRST PLACE SEEING MODEL TRENDS TOWARDS
DRIER OVERALL. INVERTED TROUGH SHOULD HAVE PUSHED THROUGH THE AREA
MONDAY NIGHT...ALLOWING A COOLER...DRIER AREA OF HIGH PRESSURE TO
BUILD IN FOR TUESDAY AND TUESDAY NIGHT. PREVIOUS FORECAST OF DRY
CONDITIONS FOR THIS TIME PERIOD STILL LOOKS GOOD...AS WELL AS THE
TEMPERATURES. REGARDING TEMPERATURES MONDAY AND MONDAY NIGHT...THESE
ARE TRICKY AS ALREADY MENTIONED TIMING OF THE TROUGH IS CRITICAL.
THERE COULD ALSO BE SOME STRATUS AND/OR ACCAS TO DEAL WITH MONDAY.
LASTLY...THE WIND FLOW MONDAY IS STILL EAST TO SOUTHEAST. ON THE
OTHER HAND...850MB TEMPS ARE 12-16C. FOR NOW COOLED HIGHS ACROSS
WISCONSIN WITH MORE CLOUDS AND CLOSER TO EASTERLY FLOW. LOCATIONS
LIKE OELWEIN AND CHARLES CITY COULD HIT 80...THOUGH.
.LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT
325 AM CDT SUN APR 1 2012
01.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES REMAIN IN GOOD AGREEMENT
OF AN OMEGA BLOCK PATTERN OVER CANADA AND THE U.S. FOR WEDNESDAY
THROUGH FRIDAY...THEN BEGINS TO BREAK DOWN HEADING INTO THE WEEKEND.
THE FORECAST AREA LIES EAST OF THE RIDGE AXIS IN THE OMEGA BLOCK...
WHICH IS IN THE DAKOTAS AND MINNESOTA THROUGH EARLY FRIDAY. THIS
FAVORS A RIDGE OF HIGH PRESSURE AT THE SURFACE WITH A COOL/DRY AIR
FEED OUT OF CANADA. STILL...TEMPERATURES LOOK LIKE THEY SHOULD END
UP A BIT ABOVE NORMAL. MAY HAVE TO DEAL WITH FROST FOR A FEW
NIGHTS...THOUGH. SOME WARMING SHOULD OCCUR ON FRIDAY AS THE UPPER
RIDGE AXIS MOVES IN AND THE SURFACE RIDGE MOVES EAST... ALLOWING A
SOUTHERLY RETURN FLOW TO DEVELOP. FOR THE WEEKEND...TROUGHING OVER
THE WESTERN U.S. IS EXPECTED TO EJECT OUT INTO THE NORTHERN
PLAINS...BRINGING A COLD FRONT INTO OR THROUGH THE FORECAST AREA
SATURDAY NIGHT. ENVISION THE WEEKEND TIMING OF ALL THIS WILL GET
ADJUSTED OVER THE COMING DAYS...AND HAVE SOME CONCERN THE MAJORITY
OF MODELS INCLUDING THE 01.00Z ECMWF ARE TOO FAST WITH THIS TIMING
GIVEN THE DOWNSTREAM RIDGE. THEREFORE...PRECIPITATION CHANCES WITH
THE WARM CONVEYOR BELT AHEAD OF THE COLD FRONT ARE HELD TO 20-30 AT
THIS TIME. DID NOT INTRODUCE ANY THUNDER BECAUSE THERE APPEARS TO BE
LIMITED INSTABILITY AT THIS TIME. TEMPERATURES SHOULD STAY ABOVE
NORMAL FOR FRIDAY NIGHT THROUGH SATURDAY NIGHT...UNTIL THE COLD
FRONT PASSES. EVEN BEHIND IT...READINGS COULD STAY NEAR OR ABOVE
NORMAL.
&&
.AVIATION...TODAY AND TONIGHT
635 AM CDT SUN APR 1 2012
LIFR/VLIFR CONDITIONS IN FOG/STRATUS CAN BE EXPECTED ACROSS
SOUTHEAST MINNESOTA THROUGH MID MORNING. PLAN ON VISIBILITIES OF
1/2 MILE IN FOG AT KRST...WITH CEILINGS AT 200FT. LOOK FOR THESE
CONDITIONS TO GRADUALLY START TO IMPROVE AROUND 14Z...WITH VFR
CONDITIONS EXPECTED BY 16Z. MVFR VISIBILITIES AT KLSE WILL QUICKLY
IMPROVE THIS MORNING WITH VFR CONDITIONS ANTICIPATED BY 14Z.
STRATUS WILL PRODUCE CLOUD BASES IN THE 3 TO 4 KFT RANGE THROUGH
MID MORNING BEFORE DISSIPATING. VFR CONDITIONS CAN BE EXPECTED AT
THE TAF SITE THIS AFTERNOON INTO THIS EVENING. SOUTHEAST WINDS ARE
EXPECTED TO INCREASE INTO THE 8 TO 16 KT RANGE THIS EVENING AS LOW
PRESSURE DEVELOPS OVER THE CENTRAL PLAINS. WILL HAVE TO KEEP A
CLOSE WATCH ON LOW LEVEL WIND SHEAR POTENTIAL TONIGHT...WITH WINDS
AROUND 1500 FT INCREASING TO 45 KTS. IN ADDITION...FORECAST
SOUNDINGS ARE SHOWING THE POTENTIAL FOR AN MVFR STRATUS DECK TO
DEVELOP AT KLSE AND KRST AS SOUTHEAST WINDS ADVECT 925 MB MOISTURE
INTO THE AREA. WILL ALSO HAVE TO MONITOR THIS POTENTIAL VERY
CLOSELY TODAY. IF THE STRATUS DEVELOPS...CLOUD BASES WILL LOWER TO
AROUND 1500 FT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
325 AM CDT SUN APR 1 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS ALBANY NY
133 PM EDT SUN APR 1 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE FROM THE GREAT LAKES AND ACROSS
THE REGION THIS AFTERNOON INTO TONIGHT...ALLOWING FOR SOME RAIN
SHOWERS. SOME WET SNOW MAY MIX IN WITH THE RAIN SHOWERS ACROSS THE
HIGHEST TERRAIN TONIGHT. HIGH PRESSURE WILL BUILD SOUTH INTO THE
REGION PROVIDING FAIR WEATHER FOR EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1245 PM...RADAR INDICATES SHOWERS MOVING SLIGHTLY FASTER THAN
CURRENT HOURLY POPS INDICATE...SO HAVE SHIFTED HOURLY POP/WX GRIDS
AHEAD BY AN HOUR. REST OF PREVIOUS FORECAST LOOKS GOOD AND WAS
UNCHANGED.
****PREVIOUS DISCUSSION****
LATEST VISIBLE SATELLITE IMAGERY SHOWS THAT LOWER STRATUS CLOUDS
HAVE COMPLETELY OVERTAKEN THE CWA. MEANWHILE...THE 12 UTC KALY
SOUNDING SHOWS ENOUGH DRY AIR IN PLACE FOR THE BOTTOM FEW THOUSAND
FEET OF THE COLUMN...AND BUFR MODEL SOUNDING SUPPORT THIS HOLDING
FOR A FEW HOURS AS WELL. THE LATEST REGIONAL RADAR IMAGERY
CONTINUES TO SHOW NO RETURNS ACROSS OUR AREA...BUT INCREASING
AMOUNTS OF LIGHT TO MODERATE PRECIP ACROSS WESTERN NY/LAKE
ONTARIO DUE TO A SHORTWAVE AND WEAK SURFACE LOW ACROSS THE GREAT
LAKES. FOR NOW...WILL CONTINUE TO FORECAST CLOUDY...BUT DRY
WEATHER FOR MUCH OF THE AREA THROUGH AROUND NOON.
FOR THE AFTERNOON HOURS...WILL STEADILY INCREASE POPS TO
CATEGORICAL FOR MOST AREAS BY THE LATE AFTN HOURS. THE NEW 12 UTC
NAM AND 10 UTC 3KM HRRR ALL SHOW BATCHES OF LIGHT RAIN SHOWERS
MOVING ACROSS THE AREA FROM NORTHWEST TO SOUTHEAST THROUGH THE
AFTN AND EVENING HOURS...WITH THE BEST QPF ACROSS THE
CATSKILLS...AS THE LOW PRESSURE WAVE MOVES ACROSS OUR AREA. ALTHOUGH
QPF SHOULD BE FAIRLY LIGHT...ALL AREAS SEEM TO AT LEAST GET A FEW
HUNDREDTHS...SO HIGH LIKELY/CATEGORICAL POPS SEEM WARRANTED. MAX
TEMPS TODAY WILL PROBABLY BE IN THE EARLY AFTN JUST BEFORE THE
START OF PRECIP...WITH TEMPS RANGING FROM THE UPPER 30S ACROSS THE
SRN DACKS TO NEAR 50 IN THE MID HUDSON VALLEY.
AFTER 00 UTC...WILL START TO LOWER POPS FROM NORTHWEST TO
SOUTHEAST...AS MODEL GUIDANCE SHOWS THE BEST FORCING AND
ASSOCIATED PRECIPITATION DROPPING SOUTHEAST OF THE REGION. AT THE
HIGHEST TERRAIN /GENERALLY 2500 FT AND ABOVE/...ANY LINGERING RAIN
SHOWERS COULD START TO MIX WITH OR CHANGE OVER TO SNOW SHOWERS AS
TEMPS ALOFT START TO CRASH. ANY SNOW ACCUMULATION LOOKS VERY
LIGHT...OF ABOUT A HALF INCH OR SO...AND MAINLY LIMITED TO THE
HIGH PEAKS OF THE CATSKILLS AND HIGHEST ELEVATIONS IN SOUTHERN
VERMONT. A COATING OF SNOW IS POSSIBLE ACROSS THE SOUTHERN
ADIRONDACKS AS WELL. VALLEY AREAS WILL PROBABLY JUST STAY AS RAIN
SHOWERS BEFORE ENDING AND NO SNOW ACCUMULATION IS EXPECTED IN ANY
VALLEY AREAS AT THIS TIME.
ANY PRECIP SHOULD BE FINISHED BY AROUND 06 UTC...WITH CLEARING
TAKING PLACE FOR THE REMAINDER OF THE NIGHT...AS SKIES BECOME
PARTLY CLOUDY. THIS SHOULD ALLOW TEMPS TO FALL OFF...WITH MIN TEMPS
RANGING FROM THE 20S IN THE DACKS TO THE MID 30S IN THE CAPITAL
REGION/MID HUDSON VALLEY.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
MONDAY INTO TUESDAY MODEL SUITE IS IN AGREEMENT OTHER THAN 6-9
HOURS DIFFERENCE IN TIMING OF TUES CDFNT AND INTENSITY OF 500HPA
SHORT WAVES WED.
FAST MOVING FLOW AT 500HPA OVER RGN...AS 500HPA TROF DEPARTS...RIDGE
BUILDS EAST...ANOTHER SHORT WV FOLLOWS LATE TUESDAY. TUESDAY NIGHT
SOME DIFFERENCES BEGIN TO EMERGE. AT SFC MASSIVE HIGH BUILDS FM
HUDSONS BAY S INTO GRTLKS AS A SERIES OF STRONG 500HPA SHORT WVS
DIVE SE ACROSS THE RGN. THE MODEL SUITE GENERALLY (GFS/GEM/12UTC
ECMWF) ARE AGGRESSIVE WITH THE SHORT WAVES...THE NAM THE LEAST AND
THE OUTLIER. THE MORE AGGRESSIVE SHORT WV SOLUTION RESULTS IN SOME
INSTAB -SHRA/SN AT HIR TRRN...VRBL CLOUDS...BRISK N WINDS AND THIS
SOLUTION IS THE ONE THE FCST WILL LEAN TWRD WITH NAM BEING THROWN
OUT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
GFS AND ECMWF FAIRLY SIMILAR IN THIS PERIOD. 500HPA TROF OVER
MARITIMES WILL SLOWLY DEPART...MASSIVE SFC HIGH FM HUDSONS BAY
WILL BUILD INTO GRTLKS. FCA WILL BE BTWN THESE TWO SYSTEMS WITH
GENERALLY DRY CONDS...SOME CLOUDS INTO FRI AS 500 HPA SHORT WAVES
ROTATED ACROSS FCA. BY SAT SFC HIGH HAS MOVED INTO RGN. GFS SHIFTS
500HPA TROF OFFSHORE...ECMWF HAS CUTOFF FORM ALONG DELMARVA/SE
COAST WHILE GFS KEEPS PROGRESSIVE TROFS MOVING OFFSHORE. ECMWF
DEVELOPS POTENTIAL COASTAL SFC LOW THAT DRIFTS N WITH CUTOFF. THIS
SYSTEM BACKS INTO FCA SUN WITH CLDS AN LT RN. FOR NOW WILL GO
W/GMOS SOLUTION. SINCE ONLY DIFFERENCE IS IN DAYS 7-8. TEMPS WILL
REMAIN NR NRMLS...REACHING 5 DEGREES ABV BY END OF PD.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
RAIN SHOWERS OVER CENTRAL NEW YORK AND THE MOHAWK VALLEY ARE
ADVANCING EAST SOUTHEAST TOWARDS THE HUDSON VALLEY TAF SITES. WITH
DRY AIR IN PLACE AT LOW LEVELS...IT MAY TAKE A LITTLE BIT UNTIL
THE BOUNDARY LAYER MOISTENS UP ENOUGH TO REDUCE FLYING CONDITIONS.
WITH SITES CURRENTLY VFR...IT MAY TAKE UNTIL THE MID TO LATE AFTN
FOR VSBYS/CIGS TO BE REDUCED TO MVFR. RAINFALL SHOULD BE
LIGHT...AND BASED ON UPSTREAM CONDITIONS...DO NOT ANTICIPATE ANY
IFR CONDITIONS WITHIN THIS RAINFALL. SFC WINDS WILL BE LIGHT AND
VARIABLE.
RAIN SHOWERS SHOULD TAPER OFF LATER IN THE EVENING...LINGERING
LONGEST /PERHAPS TOWARDS MIDNIGHT/ NEAR KPOU. AFTERWARD...WINDS
WILL SWITCH TO W-NW DIRECTION AND BECOME STRONGER...ABOUT 5-10
KTS. ANY MVFR CIGS SHOULD GIVE WAY TO VFR CONDITIONS...AS LOWER
CLOUDS LIFT TO 4-6 KFT AND BECOME SCT-BKN.
ON MONDAY...VFR CONDITIONS ARE EXPECTED WITH JUST SCT CU AROUND 6
KFT. WITHIN DAYTIME MIXING...N-NW WINDS WILL BE GUSTY AT
TIMES...ESP IN AREAS OF CHANNELED FLOW. SOME GUSTS MAY REACH 20-25
KTS...ESP BY AFTN.
OUTLOOK...
MON PM-TUE...VFR...NO SIG WX.
TUE NT...MAINLY VFR...CHC -SHRA.
WED-THU...VFR...NO SIG WX.
&&
.FIRE WEATHER...
LOW PRESSURE DROPPING SOUTHEAST FROM THE GREAT LAKES WILL MOVE
ACROSS THE REGION TODAY INTO THIS EVENING...THEN A MASSIVE HIGH
PRESSURE WILL BUILD SOUTH INTO THE REGION FOR EARLY NEXT WEEK.
AS SHOWERS MOVE ACROSS THE REGION...RELATIVE HUMIDITY VALUES WILL
GENERALLY REMAIN ABOVE 50 PERCENT. AS THIS SYSTEM DEPARTS
TONIGHT...THE WET WEATHER ALSO SUBSIDES AS RELATIVE HUMIDITIES RANGE
BETWEEN 80 AND 90 PERCENT.
SURFACE WINDS WILL BE WEST-SOUTHWEST AT 5 TO 15 MPH TODAY...BECOMING
NORTHERLY TONIGHT AT 10 MPH OR LESS...THEN INCREASING TOWARD SUNRISE
AND THROUGH THE DAY MONDAY WITH GUSTS OVER 20 MPH.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED FOR THE NEXT FIVE DAYS.
THE ONLY PCPN EXPECTED IN THE NEXT WEEK WILL BE A QUARTER TO THIRD
INCH TODAY...ISOLATED -SHRA LATE TUESDAY. OTHERWISE WILL BE DRY
WITH TEMPS BLO NORMAL AT FIRST...RISING NEAR NORMAL MID WEEK AND
ENDING THE WEEK ABV NORMALS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS/GJM
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...FRUGIS
FIRE WEATHER...BGM
HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
110 AM EDT SUN APR 1 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE FROM THE GREAT LAKES AND ACROSS
THE REGION THIS AFTERNOON INTO TONIGHT...ALLOWING FOR SOME RAIN
SHOWERS. SOME WET SNOW MAY MIX IN WITH THE RAIN SHOWERS ACROSS THE
HIGHEST TERRAIN TONIGHT. HIGH PRESSURE WILL BUILD SOUTH INTO THE
REGION PROVIDING FAIR WEATHER FOR EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1245 PM...RADAR INDICATES SHOWERS MOVING SLIGHTLY FASTER THAN
CURRENT HOURLY POPS INDICATE...SO HAVE SHIFTED HOURLY POP/WX GRIDS
AHEAD BY AN HOUR. REST OF PREVIOUS FORECAST LOOKS GOOD AND WAS
UNCHANGED.
****PREVIOUS DISCUSSION****
LATEST VISIBLE SATELLITE IMAGERY SHOWS THAT LOWER STRATUS CLOUDS
HAVE COMPLETELY OVERTAKEN THE CWA. MEANWHILE...THE 12 UTC KALY
SOUNDING SHOWS ENOUGH DRY AIR IN PLACE FOR THE BOTTOM FEW THOUSAND
FEET OF THE COLUMN...AND BUFR MODEL SOUNDING SUPPORT THIS HOLDING
FOR A FEW HOURS AS WELL. THE LATEST REGIONAL RADAR IMAGERY
CONTINUES TO SHOW NO RETURNS ACROSS OUR AREA...BUT INCREASING
AMOUNTS OF LIGHT TO MODERATE PRECIP ACROSS WESTERN NY/LAKE
ONTARIO DUE TO A SHORTWAVE AND WEAK SURFACE LOW ACROSS THE GREAT
LAKES. FOR NOW...WILL CONTINUE TO FORECAST CLOUDY...BUT DRY
WEATHER FOR MUCH OF THE AREA THROUGH AROUND NOON.
FOR THE AFTERNOON HOURS...WILL STEADILY INCREASE POPS TO
CATEGORICAL FOR MOST AREAS BY THE LATE AFTN HOURS. THE NEW 12 UTC
NAM AND 10 UTC 3KM HRRR ALL SHOW BATCHES OF LIGHT RAIN SHOWERS
MOVING ACROSS THE AREA FROM NORTHWEST TO SOUTHEAST THROUGH THE
AFTN AND EVENING HOURS...WITH THE BEST QPF ACROSS THE
CATSKILLS...AS THE LOW PRESSURE WAVE MOVES ACROSS OUR AREA. ALTOUGH
QPF SHOULD BE FAIRLY LIGHT...ALL AREAS SEEM TO AT LEAST GET A FEW
HUNDREDTHS...SO HIGH LIKELY/CATEGORICAL POPS SEEM WARRANTED. MAX
TEMPS TODAY WILL PROBABLY BE IN THE EARLY AFTN JUST BEFORE THE
START OF PRECIP...WITH TEMPS RANGING FROM THE UPPER 30S ACROSS THE
SRN DACKS TO NEAR 50 IN THE MID HUDSON VALLEY.
AFTER 00 UTC...WILL START TO LOWER POPS FROM NORTHWEST TO
SOUTHEAST...AS MODEL GUIDANCES SHOWS THE BEST FORCING AND
ASSOCIATED PRECIPITATION DROPPING SOUTHEAST OF THE REGION. AT THE
HIGHEST TERRAIN /GENERALLY 2500 FT AND ABOVE/...ANY LINGERING RAIN
SHOWERS COULD START TO MIX WITH OR CHANGE OVER TO SNOW SHOWERS AS
TEMPS ALOFT START TO CRASH. ANY SNOW ACCUMULATION LOOKS VERY
LIGHT...OF ABOUT A HALF INCH OR SO...AND MAINLY LIMITED TO THE
HIGH PEAKS OF THE CATSKILLS AND HIGHEST ELEVATIONS IN SOUTHERN
VERMONT. A COATING OF SNOW IS POSSIBLE ACROSS THE SOUTHERN
ADIRONDACKS AS WELL. VALLEY AREAS WILL PROBABLY JUST STAY AS RAIN
SHOWERS BEFORE ENDING AND NO SNOW ACCUMULATION IS EXPECTED IN ANY
VALLEY AREAS AT THIS TIME.
ANY PRECIP SHOULD BE FINISHED BY AROUND 06 UTC...WITH CLEARING
TAKING PLACE FOR THE REMAINDER OF THE NIGHT...AS SKIES BECOME
PARTLY CLOUDY. THIS SHOULD ALLOW TEMPS TO FALL OFF...WITH MIN TEMPS
RANGING FROM THE 20S IN THE DACKS TO THE MID 30S IN THE CAPITAL
REGION/MID HUDSON VALLEY.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
MONDAY INTO TUESDAY MODEL SUITE IS IN AGREEMENT OTHER THAN 6-9
HOURS DIFFERENCE IN TIMING OF TUES CDFNT AND INTENSITY OF 500HPA
SHORT WAVES WED.
FAST MOVING FLOW AT 500HPA OVER RGN...AS 500HPA TROF DEPARTS...RIDGE
BUILDS EAST...ANOTHER SHORT WV FOLLOWS LATE TUESDAY. TUESDAY NIGHT
SOME DIFFERENCES BEGIN TO EMERGE. AT SFC MASSIVE HIGH BUILDS FM
HUDSONS BAY S INTO GRTLKS AS A SERIES OF STRONG 500HPA SHORT WVS
DIVE SE ACROSS THE RGN. THE MODEL SUITE GENERALLY (GFS/GEM/12UTC
ECMWF) ARE AGGRESSIVE WITH THE SHORT WAVES...THE NAM THE LEAST AND
THE OUTLIER. THE MORE AGGRESSIVE SHORT WV SOLUTION RESULTS IN SOME
INSTAB -SHRA/SN AT HIR TRRN...VRBL CLOUDS...BRISK N WINDS AND THIS
SOLUTION IS THE ONE THE FCST WILL LEAN TWRD WITH NAM BEING THROWN
OUT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
GFS AND ECMWF FAIRLY SIMILAR IN THIS PERIOD. 500HPA TROF OVER
MARITIMES WILL SLOWLY DEPART...MASSIVE SFC HIGH FM HUDSONS BAY
WILL BUILD INTO GRTLKS. FCA WILL BE BTWN THESE TWO SYSTEMS WITH
GENERALLY DRY CONDS...SOME CLOUDS INTO FRI AS 500 HPA SHORT WAVES
ROTATED ACROSS FCA. BY SAT SFC HIGH HAS MOVED INTO RGN. GFS SHIFTS
500HPA TROF OFFSHORE...ECMWF HAS CUTOFF FORM ALONG DELMARVA/SE
COAST WHILE GFS KEEPS PROGRESSIVE TROFS MOVING OFFSHORE. ECMWF
DEVELOPS POTENTIAL COASTAL SFC LOW THAT DRIFTS N WITH CUTOFF. THIS
SYSTEM BACKS INTO FCA SUN WITH CLDS AN LT RN. FOR NOW WILL GO
W/GMOS SOLUTION. SINCE ONLY DIFFERENCE IS IN DAYS 7-8. TEMPS WILL
REMAIN NR NRMLS...REACHING 5 DEGREES ABV BY END OF PD.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS DESPITE THE EXPANDING STRATUS DECK ACROSS THE
REGION. UPSTREAM SYSTEM APPROACHES DURING THE DAY WITH LOWER CIGS
AND INCREASING CHANCES FOR WET CONDITIONS. THERE WILL BE A PERIOD
LATER THIS AFTERNOON INTO EARLY EVENING WITH MVFR FLIGHT
CONDITIONS.
WINDS WILL BE LIGHT AND VARIABLE THIS EARLY SUNDAY MORNING. THOSE
WINDS BECOME WEST-SOUTHWEST LATE THIS MORNING IN ADVANCE OF THIS
SYSTEM AT SPEEDS LESS THAN 10KTS. WINDS QUICKLY SHIFT TO THE
NORTH-NORTHWEST IN THE WAKE OF THIS STORM THIS EVENING AROUND 10 KTS
AND CONTINUE OVERNIGHT.
OUTLOOK...
MON-TUE...VFR...NO SIG WX.
TUE NT...MAINLY VFR...CHC -RA OR -SHRA.
WED-THU...VFR...NO SIG WX.
&&
.FIRE WEATHER...
LOW PRESSURE DROPPING SOUTHEAST FROM THE GREAT LAKES WILL MOVE
ACROSS THE REGION TODAY INTO THIS EVENING...THEN A MASSIVE HIGH
PRESSURE WILL BUILD SOUTH INTO THE REGION FOR EARLY NEXT WEEK.
AS SHOWERS MOVE ACROSS THE REGION...RELATIVE HUMIDITY VALUES WILL
GENERALLY REMAIN ABOVE 50 PERCENT. AS THIS SYSTEM DEPARTS
TONIGHT...THE WET WEATHER ALSO SUBSIDES AS RELATIVE HUMIDITIES RANGE
BETWEEN 80 AND 90 PERCENT.
SURFACE WINDS WILL BE WEST-SOUTHWEST AT 5 TO 15 MPH TODAY...BECOMING
NORTHERLY TONIGHT AT 10 MPH OR LESS...THEN INCREASING TOWARD SUNRISE
AND THROUGH THE DAY MONDAY WITH GUSTS OVER 20 MPH.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED FOR THE NEXT FIVE DAYS.
THE ONLY PCPN EXPECTED IN THE NEXT WEEK WILL BE A QUARTER TO THIRD
INCH TODAY...ISOLATED -SHRA LATE TUESDAY. OTHERWISE WILL BE DRY
WITH TEMPS BLO NORMAL AT FIRST...RISING NEAR NORMAL MID WEEK AND
ENDING THE WEEK ABV NORMALS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...GJM/FRUGIS
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...BGM
FIRE WEATHER...BGM
HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
223 PM CDT SUN APR 1 2012
.DISCUSSION...
1005 AM CDT
THE EARLY MORNING STORMS HAVE MOVED QUICKLY SOUTHEAST INTO
SOUTHERN INDIANA. IN THEIR WAKE...THEY HELPED TO SINK THE FRONTAL
BOUNDARY SOUTH TO NEAR INTERSTATE 88 AT AROUND 10 AM. TO THE
NORTH...WHERE STRATUS AND NORTHERLY WINDS PREVAIL...TEMPERATURES
HAVE BEEN BASICALLY FLAT LINE. WHILE SOME MIXING OUT OF THE
STRATUS MAY OCCUR LATE THIS MORNING...REINFORCING NORTHEAST COLD
AIR ADVECTION WILL EVOLVE AS A WEAK LOW SHIFTS EAST ALONG THE
FRONTAL BOUNDARY. THIS SCENARIO SHOULD ENABLE THE FRONT TO MOVE
SOUTH KEEPING TEMPERATURES COOLER TO THE NORTH...WITH PLACES
SEEING A FALL THIS AFTERNOON ESPECIALLY IN THE NEAR DOWNSTREAM OF
LAKE MICHIGAN. THE 01.12 NAM CAPTURES THIS TREND WELL...AND SEEMS
TO HAVE A DECENT HANDLE ON THE STRATUS EVOLUTION...HINTING AT LOW
CLOUDS ALONG AND IMMEDIATELY BEHIND THE BOUNDARY THROUGH THIS
AFTERNOON.
IT IS A TALE OF TWO DIFFERENT DAYS ACROSS THE CWA AS TO THE SOUTH
OF THE FRONT...TEMPERATURES ARE OFF TO THE RACES WITH MID 60S
ALREADY AT 10 AM IN PERU AND PONTIAC. A WARM-UP TO AROUND OR JUST
ABOVE 80 DEGREES STILL LOOKS WELL IN PLACE...ESPECIALLY SEEING
GUSTS TO AROUND 20 KTS ALREADY INDICATING GOOD MIXING AND
CONTINUED LOW- LEVEL WARM AIR ADVECTION. THE 12Z ILX RAOB HAD NEAR
1300 J/KG OF MUCAPE WHICH SHOULD BE A GOOD BASELINE FOR WHAT IS
SHIFTING OVER THE SOUTHERN FORECAST AREA AS IT CONTINUES TO WARM.
THIS LOOKS TO MAXIMIZE/POOL THIS AFTERNOON BETWEEN 1500 AND 2000
J/KG IN THE FAR SOUTH...BUT IN THE ABSENCE OF ANY PRONOUNCED
TRIGGER AND A QUICKLY WEAKENING LOW- LEVEL JET. THE WEAK SURFACE
CIRCULATION ALONG THE BOUNDARY MAY HELP TO INCREASE CONVERGENCE
SOME AS IT SHIFTS EAST THROUGH THE AFTERNOON. ALSO...AN ILL-
DEFINED SHORT WAVE RIPPLE IN EASTERN IA IS SHIFTING EAST. TOGETHER
IT MIGHT BE ENOUGH TO SPARK ISOLATED THUNDERSTORMS...GENERALLY
SOUTH OF U.S. HIGHWAY 24 THIS AFTERNOON. ABOUT ONE THIRD OF
EXPLICIT CONVECTIVE GUIDANCE LOOKED AT HAS THAT FORM OF SOLUTION.
INSTABILITY PROFILES ARE ENOUGH TO WARRANT MAINLY A HAIL THREAT IF
ANY STORM WERE TO SUSTAIN ITSELF.
MTF
//PREV DISCUSSION...
315 AM CDT
THIS MORNING HIGH PRESSURE OVER THE EASTERN GREAT LAKES REGION WILL
PUSH EASTWARD WITH FRONTAL BOUNDARY SLOWLY TRYING TO LIFT NORTHWARD
THROUGH THE EARLY MORNING HOURS. ONGOING ELEVATED CONVECTION ON NOSE
OF LOW LEVEL JET WILL CONTINUE TO PUSH SOUTHEAST ACROSS THE REGION
RIDING H5 HEIGHTS DOWN THE RIDGE ALONG THE INSTABILITY GRADIENT.
SEVERE THREAT THROUGH THE PREDAWN HOURS WILL REMAIN MARGINAL...BUT
LATEST RUC CONTINUES TO SHOW NEAR 1000 J/KG GENERALLY ALONG AND WEST
OF THE I39 CORRIDOR SUPPORTING AT LEAST SOME THREAT FOR HAIL. THREAT
SHOULD TAPER THROUGH DAYBREAK THIS MORNING AS LOW LEVEL JET VEERS
AND THETA E ADVECTION WEAKENS. MEANWHILE...WEAK AREA OF LOW
PRESSURE NEAR LAKE SUPERIOR WILL PUSH EAST INTO SOUTHEASTERN
ONTARIO BY EARLY THIS AFTERNOON. GUIDANCE SUGGESTS BAROCLINIC ZONE
WILL BE FARTHER SOUTH/WEST THAN ORIGINALLY ANTICIPATED THUS BUMPED
DOWN TEMPERATURES SLIGHTLY ACROSS THE AREA FOR THIS AFTERNOON. IN
ADDITION WINDS TURNING TO THE NORTHEAST BY MID MORNING IN RESPONSE
TO LOW MOVING ACROSS ONTARIO WILL LIMIT HIGH TEMPS ALONG THE LAKE
SHORE...WITH TEMPERATURES FALLING INLAND THROUGH THE AFTERNOON AS
MARINE LAYER SPREADS INLAND.
MONDAY...GUIDANCE CONTINUES TO STRUGGLE WITH PLACEMENT OF BAROCLINIC
ZONE/LOW PRESSURE. A LARGE TEMPERATURE SPREAD IS STILL EXPECTED TO
SET UP ACROSS THE CWA. MAJORITY OF GUIDANCE SHOWS SOUTHWEST PORTIONS
OF THE CWA TRYING TO REACHING THE 80 MARK...BUT WARMER TEMPERATURES
ARE NOW EXPECTED TO BE FARTHER WEST. ALSO HAD TO DROP TEMPERATURES
ALONG THE LAKE FRONT SEVERAL DEGREES AS LATEST GUIDANCE IN GENERAL
SUGGESTS 60S POSSIBLY EVEN 50S AS WE STAY UNDER SOUTHEAST FLOW
THROUGH THE DAY WITH WINDS OFF THE LAKE IN ILLINOIS. AM CONCERNED
TEMPS ARE STILL A LITTLE HIGH THOUGH FOR MONDAY ALONG THE ILLINOIS
SHORES.
TUESDAY THOUGH SATURDAY...COLD FRONT WILL SWEEP ACROSS THE REGION
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS.
BROAD AREA OF HIGH PRESSURE BUILDS ACROSS THE CANADIAN PRAIRIES EAST
TOWARDS THE GREAT LAKE REGION THROUGH THE END OF THE WEEK. NORTHERN
ILLINOIS AND NORTHWEST INDIANA WILL BE IN AREA OF NORTHERLY FLOW AND
EXPECT TO BE CLIPPED BY COOLER AIR ALOFT //H85 TEMPS FALLING TO
AROUND -3C THURSDAY// BEHIND THE COLD FRONT. SHOULD SEE PLENTY OF
SUNSHINE FOR THE LATTER HALF OF THE WEEK. TEMPERATURES WILL CONTINUE
TO RUN SLIGHTLY ABOVE NORMAL...BUT SHOULD BE MORE SEASONABLE WITH
HIGHS IN THE UPPER 50S TO LOW 60S AND LOWS IN THE UPPER 30S TO LOW
40S. BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* PERSISTENT FOG WITH 4-5SM VIS TO LINGER THROUGH THE AFTERNOON
AND OVERNIGHT HOURS.
* HIGH END MVFR CEILINGS THIS AFTERNOON BEFORE BECOMING VFR THIS
EVENING.
* NORTHEAST WINDS THIS AFTERNOON AND EVENING BECOMING EAST
SOUTHEAST MONDAY MORNING.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
A COMPLEX WEATHER PATTERN REMAINS OVER THE TERMINALS EARLY THIS
AFTERNOON AS A FRONTAL BOUNDARY IS SITUATED ACROSS NORTHERN
ILLINOIS AND NORTHWEST INDIANA. ITS THIS BOUNDARY WHICH IS HELPING
TO PROVIDE VARYING SKY AND WEATHER CONDITIONS OVER RATHER SMALL
DISTANCES. LOWER CEILINGS WHICH HAVE BEEN SITUATED OVER FAR
NORTHERN ILLINOIS AND SOUTHERN WISCONSIN HAVE FINALLY WORKED THEIR
WAY SOUTH OVER ALL OF THE TERMINALS...WITH THE EXCEPTION OF GYY AT
THIS TIME. WITH THIS SOUTHERLY PUSH...HIGH END MVFR CEILINGS HAVE
SHIFTED OVERHEAD AND EXPECT THESE CEILINGS/HEIGHTS TO REMAIN
THROUGH THE REMAINDER OF THE AFTERNOON/EARLY EVENING WITH GYY ALSO
OBSERVING THESE LOWER CEILINGS THIS AFTERNOON. THE OVERALL EXTENT
OF THIS LOW CLOUD COVER HAS BEEN ERODING ON ALL SIDES TODAY AND
EXPECT THIS TO CONTINUE AS DRIER AIR TO THE NORTH ADVECTS
SOUTH...WITH CEILINGS TO SCATTER/SHIFT OUT OF THE TERMINALS LATER
THIS EVENING. WITH THE BOUNDARY OVER THE TERMINALS TODAY...FOG
WITH VIS OF 3-5SM HAS BEEN IN PLACE. INITIAL THOUGHTS WERE THAT
THIS FOG WOULD SCATTER OUT BY MID DAY...BUT LATEST THINKING HAS
SINCE CHANGED WITH LITTLE IF ANY IMPROVEMENT HAS BEEN OBSERVED.
NOW THAT THESE LOWER CEILINGS HAVE MOVED OVERHEAD...DONT SEE ANY
REASON WHY THE FOG WILL IMPROVE THROUGH THE REMAINDER OF THE
AFTERNOON. SO HAVE INCLUDED FOG OF 4-5SM THROUGH THIS AFTERNOON
AND EVENING...WITH CONDITIONS TO IMPROVE BY MONDAY MORNING.
WINDS WILL HOLD OUT OF THE NORTHEAST THIS AFTERNOON WITH SOME
INCREASE IN SPEED...BUT WITH NO PREVAILING GUSTS EXPECTED. THEN
WINDS WILL SLOWLY SHIFT TO MORE OF AN EAST SOUTHEAST DIRECTION
TONIGHT INTO MONDAY WITH SPEEDS/GUSTS INCREASING THROUGHOUT THE DAY
WITH DAY TIME MIXING.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM HIGH CONFIDENCE WITH FOG/VIS TRENDS.
* MEDIUM CONFIDENCE WITH CEILINGS/TRENDS THIS AFTERNOON AND
EVENING.
* HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...VFR WITH CHANCE TSRA.
TUESDAY...VFR WITH CHANCE SHRA/TSRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
MDB
&&
.MARINE...
220 PM CDT
LIGHT EAST TO NORTHEAST WINDS WILL BE WITH US THROUGH TUESDAY. A
LARGE HIGH PRESSURE IS CURRENTLY OVER HUDSON BAY...AND A SERIES OF
LOWS EXTEND FROM SASKATCHEWAN THROUGH THE CENTRAL GREAT PLAINS. AS
THE LOWS MOVE EASTWARD EARLY THIS WEEK...THE GRADIENT OVER THE
SOUTHERN HALF OF THE LAKE WILL TIGHTEN...BUT WINDS ARE EXPECTED TO
BE 25 KT OR LESS THROUGHOUT THE FORECAST. ALTHOUGH WINDS WILL BE
LIGHT...AN EXTENDED PERIOD OF EASTERLY WINDS RAISES CONCERNS OF
HIGHER WAVES ACROSS THE ILLINOIS NEARSHORE ZONES. NO PLANS TO ISSUE
A SMALL CRAFT ADVISORY...BUT WILL MONITOR TRENDS. THE SOUTHERN LOW
WEAKENS AS IT PASSES OVER SOUTHERN LAKE MICHIGAN TUESDAY. EXACT
TIMING OF WHEN THE LOW WILL PASS OVER THE LAKE IS UNCERTAIN AS THE
MODELS SHOW A 6 HOUR DIFFERENCE IN TIMING. THE NORTHERN LOW MOVES
EASTWARD INTO NORTHERN ONTARIO...AND ITS COLD FRONT MOVES SOUTHWARD
ACROSS THE LAKE TUESDAY. WINDS WILL SHIFT FROM SOUTH TO NORTH
BEHIND THE FRONT. HIGH PRESSURE BUILDS IN BEHIND THE COLD FRONT
LEADING TO ANOTHER PERIOD OF NORTHEAST TO EAST WINDS OF 20 KT OR
LESS THROUGH THE END OF THE WEEK.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
114 PM CDT SUN APR 1 2012
.DISCUSSION...
1005 AM CDT
THE EARLY MORNING STORMS HAVE MOVED QUICKLY SOUTHEAST INTO
SOUTHERN INDIANA. IN THEIR WAKE...THEY HELPED TO SINK THE FRONTAL
BOUNDARY SOUTH TO NEAR INTERSTATE 88 AT AROUND 10 AM. TO THE
NORTH...WHERE STRATUS AND NORTHERLY WINDS PREVAIL...TEMPERATURES
HAVE BEEN BASICALLY FLAT LINE. WHILE SOME MIXING OUT OF THE
STRATUS MAY OCCUR LATE THIS MORNING...REINFORCING NORTHEAST COLD
AIR ADVECTION WILL EVOLVE AS A WEAK LOW SHIFTS EAST ALONG THE
FRONTAL BOUNDARY. THIS SCENARIO SHOULD ENABLE THE FRONT TO MOVE
SOUTH KEEPING TEMPERATURES COOLER TO THE NORTH...WITH PLACES
SEEING A FALL THIS AFTERNOON ESPECIALLY IN THE NEAR DOWNSTREAM OF
LAKE MICHIGAN. THE 01.12 NAM CAPTURES THIS TREND WELL...AND SEEMS
TO HAVE A DECENT HANDLE ON THE STRATUS EVOLUTION...HINTING AT LOW
CLOUDS ALONG AND IMMEDIATELY BEHIND THE BOUNDARY THROUGH THIS
AFTERNOON.
IT IS A TALE OF TWO DIFFERENT DAYS ACROSS THE CWA AS TO THE SOUTH
OF THE FRONT...TEMPERATURES ARE OFF TO THE RACES WITH MID 60S
ALREADY AT 10 AM IN PERU AND PONTIAC. A WARM-UP TO AROUND OR JUST
ABOVE 80 DEGREES STILL LOOKS WELL IN PLACE...ESPECIALLY SEEING
GUSTS TO AROUND 20 KTS ALREADY INDICATING GOOD MIXING AND
CONTINUED LOW- LEVEL WARM AIR ADVECTION. THE 12Z ILX RAOB HAD NEAR
1300 J/KG OF MUCAPE WHICH SHOULD BE A GOOD BASELINE FOR WHAT IS
SHIFTING OVER THE SOUTHERN FORECAST AREA AS IT CONTINUES TO WARM.
THIS LOOKS TO MAXIMIZE/POOL THIS AFTERNOON BETWEEN 1500 AND 2000
J/KG IN THE FAR SOUTH...BUT IN THE ABSENCE OF ANY PRONOUNCED
TRIGGER AND A QUICKLY WEAKENING LOW- LEVEL JET. THE WEAK SURFACE
CIRCULATION ALONG THE BOUNDARY MAY HELP TO INCREASE CONVERGENCE
SOME AS IT SHIFTS EAST THROUGH THE AFTERNOON. ALSO...AN ILL-
DEFINED SHORT WAVE RIPPLE IN EASTERN IA IS SHIFTING EAST. TOGETHER
IT MIGHT BE ENOUGH TO SPARK ISOLATED THUNDERSTORMS...GENERALLY
SOUTH OF U.S. HIGHWAY 24 THIS AFTERNOON. ABOUT ONE THIRD OF
EXPLICIT CONVECTIVE GUIDANCE LOOKED AT HAS THAT FORM OF SOLUTION.
INSTABILITY PROFILES ARE ENOUGH TO WARRANT MAINLY A HAIL THREAT IF
ANY STORM WERE TO SUSTAIN ITSELF.
MTF
//PREV DISCUSSION...
315 AM CDT
THIS MORNING HIGH PRESSURE OVER THE EASTERN GREAT LAKES REGION WILL
PUSH EASTWARD WITH FRONTAL BOUNDARY SLOWLY TRYING TO LIFT NORTHWARD
THROUGH THE EARLY MORNING HOURS. ONGOING ELEVATED CONVECTION ON NOSE
OF LOW LEVEL JET WILL CONTINUE TO PUSH SOUTHEAST ACROSS THE REGION
RIDING H5 HEIGHTS DOWN THE RIDGE ALONG THE INSTABILITY GRADIENT.
SEVERE THREAT THROUGH THE PREDAWN HOURS WILL REMAIN MARGINAL...BUT
LATEST RUC CONTINUES TO SHOW NEAR 1000 J/KG GENERALLY ALONG AND WEST
OF THE I39 CORRIDOR SUPPORTING AT LEAST SOME THREAT FOR HAIL. THREAT
SHOULD TAPER THROUGH DAYBREAK THIS MORNING AS LOW LEVEL JET VEERS
AND THETA E ADVECTION WEAKENS. MEANWHILE...WEAK AREA OF LOW
PRESSURE NEAR LAKE SUPERIOR WILL PUSH EAST INTO SOUTHEASTERN
ONTARIO BY EARLY THIS AFTERNOON. GUIDANCE SUGGESTS BAROCLINIC ZONE
WILL BE FARTHER SOUTH/WEST THAN ORIGINALLY ANTICIPATED THUS BUMPED
DOWN TEMPERATURES SLIGHTLY ACROSS THE AREA FOR THIS AFTERNOON. IN
ADDITION WINDS TURNING TO THE NORTHEAST BY MID MORNING IN RESPONSE
TO LOW MOVING ACROSS ONTARIO WILL LIMIT HIGH TEMPS ALONG THE LAKE
SHORE...WITH TEMPERATURES FALLING INLAND THROUGH THE AFTERNOON AS
MARINE LAYER SPREADS INLAND.
MONDAY...GUIDANCE CONTINUES TO STRUGGLE WITH PLACEMENT OF BAROCLINIC
ZONE/LOW PRESSURE. A LARGE TEMPERATURE SPREAD IS STILL EXPECTED TO
SET UP ACROSS THE CWA. MAJORITY OF GUIDANCE SHOWS SOUTHWEST PORTIONS
OF THE CWA TRYING TO REACHING THE 80 MARK...BUT WARMER TEMPERATURES
ARE NOW EXPECTED TO BE FARTHER WEST. ALSO HAD TO DROP TEMPERATURES
ALONG THE LAKE FRONT SEVERAL DEGREES AS LATEST GUIDANCE IN GENERAL
SUGGESTS 60S POSSIBLY EVEN 50S AS WE STAY UNDER SOUTHEAST FLOW
THROUGH THE DAY WITH WINDS OFF THE LAKE IN ILLINOIS. AM CONCERNED
TEMPS ARE STILL A LITTLE HIGH THOUGH FOR MONDAY ALONG THE ILLINOIS
SHORES.
TUESDAY THOUGH SATURDAY...COLD FRONT WILL SWEEP ACROSS THE REGION
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS.
BROAD AREA OF HIGH PRESSURE BUILDS ACROSS THE CANADIAN PRAIRIES EAST
TOWARDS THE GREAT LAKE REGION THROUGH THE END OF THE WEEK. NORTHERN
ILLINOIS AND NORTHWEST INDIANA WILL BE IN AREA OF NORTHERLY FLOW AND
EXPECT TO BE CLIPPED BY COOLER AIR ALOFT //H85 TEMPS FALLING TO
AROUND -3C THURSDAY// BEHIND THE COLD FRONT. SHOULD SEE PLENTY OF
SUNSHINE FOR THE LATTER HALF OF THE WEEK. TEMPERATURES WILL CONTINUE
TO RUN SLIGHTLY ABOVE NORMAL...BUT SHOULD BE MORE SEASONABLE WITH
HIGHS IN THE UPPER 50S TO LOW 60S AND LOWS IN THE UPPER 30S TO LOW
40S. BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* PERSISTENT FOG WITH 4-5SM VIS TO LINGER THROUGH THE AFTERNOON
AND OVERNIGHT HOURS.
* HIGH END MVFR CEILINGS THIS AFTERNOON BEFORE BECOMING VFR THIS
EVENING.
* NORTHEAST WINDS THIS AFTERNOON AND EVENING BECOMING EAST
SOUTHEAST MONDAY MORNING.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
A COMPLEX WEATHER PATTERN REMAINS OVER THE TERMINALS EARLY THIS
AFTERNOON AS A FRONTAL BOUNDARY IS SITUATED ACROSS NORTHERN
ILLINOIS AND NORTHWEST INDIANA. ITS THIS BOUNDARY WHICH IS HELPING
TO PROVIDE VARYING SKY AND WEATHER CONDITIONS OVER RATHER SMALL
DISTANCES. LOWER CEILINGS WHICH HAVE BEEN SITUATED OVER FAR
NORTHERN ILLINOIS AND SOUTHERN WISCONSIN HAVE FINALLY WORKED THEIR
WAY SOUTH OVER ALL OF THE TERMINALS...WITH THE EXCEPTION OF GYY AT
THIS TIME. WITH THIS SOUTHERLY PUSH...HIGH END MVFR CEILINGS HAVE
SHIFTED OVERHEAD AND EXPECT THESE CEILINGS/HEIGHTS TO REMAIN
THROUGH THE REMAINDER OF THE AFTERNOON/EARLY EVENING WITH GYY ALSO
OBSERVING THESE LOWER CEILINGS THIS AFTERNOON. THE OVERALL EXTENT
OF THIS LOW CLOUD COVER HAS BEEN ERODING ON ALL SIDES TODAY AND
EXPECT THIS TO CONTINUE AS DRIER AIR TO THE NORTH ADVECTS
SOUTH...WITH CEILINGS TO SCATTER/SHIFT OUT OF THE TERMINALS LATER
THIS EVENING. WITH THE BOUNDARY OVER THE TERMINALS TODAY...FOG
WITH VIS OF 3-5SM HAS BEEN IN PLACE. INITIAL THOUGHTS WERE THAT
THIS FOG WOULD SCATTER OUT BY MID DAY...BUT LATEST THINKING HAS
SINCE CHANGED WITH LITTLE IF ANY IMPROVEMENT HAS BEEN OBSERVED.
NOW THAT THESE LOWER CEILINGS HAVE MOVED OVERHEAD...DONT SEE ANY
REASON WHY THE FOG WILL IMPROVE THROUGH THE REMAINDER OF THE
AFTERNOON. SO HAVE INCLUDED FOG OF 4-5SM THROUGH THIS AFTERNOON
AND EVENING...WITH CONDITIONS TO IMPROVE BY MONDAY MORNING.
WINDS WILL HOLD OUT OF THE NORTHEAST THIS AFTERNOON WITH SOME
INCREASE IN SPEED...BUT WITH NO PREVAILING GUSTS EXPECTED. THEN
WINDS WILL SLOWLY SHIFT TO MORE OF AN EAST SOUTHEAST DIRECTION
TONIGHT INTO MONDAY WITH SPEEDS/GUSTS INCREASING THROUGHOUT THE DAY
WITH DAY TIME MIXING.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM HIGH CONFIDENCE WITH FOG/VIS TRENDS.
* MEDIUM CONFIDENCE WITH CEILINGS/TRENDS THIS AFTERNOON AND
EVENING.
* HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...VFR WITH CHANCE TSRA.
TUESDAY...VFR WITH CHANCE SHRA/TSRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
MDB
&&
.MARINE...
210 AM CDT
HIGH PRESSURE OVER OHIO EXTENDS NORTHEASTWARD ACROSS THE ST.
LAWRENCE VALLEY THIS MORNING WHILE A COMPLEX SERIES OF WEAK LOW
PRESSURE SYSTEMS ARE NOTED FROM LAKE SUPERIOR INTO THE MID
MISSISSIPPI RIVER VALLEY...WITH BETTER ORGANIZED LOW PRESSURE IN THE
LEE OF THE ROCKIES. ONE LOW...OVER LAKE SUPERIOR...WILL MOVE
SOUTHEASTWARD TODAY AND MOVE OFF THE EAST COAST THIS EVENING WHERE
IT WILL DEEPEN. ANOTHER AREA OF LOW PRESSURE OVER WESTERN IOWA
WILL DRIFT EAST WITH A COOL FRONTAL BOUNDARY SETTING UP FROM THE
FIRST LOW INTO THIS WEAKER LOW. HIGH PRESSURE WILL THEN SPREAD
SOUTHWARD FROM HUDSON BAY AND INTO THE GREAT LAKES BEHIND THE
LOW. AS A RESULT OF THIS FAIRLY COMPLEX PATTERN SOUTHERLY WINDS IN
PLACE ACROSS LAKE MICHIGAN THIS MORNING WILL TURN NORTHEASTERLY
TODAY AND EASTERLY TONIGHT...BEFORE BECOMING SOUTHEAST FOR MONDAY.
IT APPEARS THAT THERE WILL BE SEVERAL PERIODS OF STRONGER WINDS
FROM TONIGHT THROUGH TUESDAY AS THE PRESSURE GRADIENT MODULATES
BETWEEN SYSTEMS. THE FIRST INCREASE SHOULD OCCUR TONIGHT ACROSS
CENTRAL AND SOUTHERN PARTS OF THE LAKE WITH GUSTS TO AROUND 25 KT
EXPECTED. SPEEDS LOOK TO EASE SOMEWHAT MONDAY BEFORE INCREASING
AGAIN MONDAY EVENING THEN DROPPING OFF TUESDAY MORNING AS A LOW
PASSES JUST TO THE SOUTH. THE GRADIENT TIGHTENS BEHIND THE LOW
TUESDAY AFTERNOON AS STRONG HIGH PRESSURE SPREADS INTO THE UPPER
MISSISSIPPI RIVER VALLEY. THIS LOOKS TO BE THE PERIOD OF STRONGEST
WINDS WITH 30 KT POSSIBLE FROM THE NORTH. THE HIGH THEN GRADUALLY
SPREADS EASTWARD KEEPING ITS INFLUENCE OVER THE LAKE THROUGH THE
END OF THE WEEK. LOWS WILL PASS TO THE EAST AND SOUTH OF THE LAKE
SO PERIODS OF SLIGHTLY STRONGER WINDS WILL BE POSSIBLE DESPITE THE
PRESENCE OF THE HIGH...BUT HIGHEST SPEEDS LOOK TO BE UNDER 20 KTS
OR SO FROM MID WEEK ONWARD.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1258 PM CDT SUN APR 1 2012
.DISCUSSION...
ISSUED 1040 AM CDT SUN APR 1 2012
PRECIP ASSOCIATED WITH EXITING MCS WELL OFF TO THE EAST LEAVING
SUNNY SKIES IN ITS WAKE. TEMPERATURES ARE QUICK TO REBOUND AS
WELL...LENDING MORE CONFIDENCE TO THE WARM FORECAST. NEWEST NAM
KEEPS AFTERNOON DRY...CONSIDERING THE RAPID RETREAT OF THE SHOWERS
THIS MORNING...WILL KEEP ISL WORDING...AND NOT RAISE THE POP THIS
AFTERNOON IN THE EAST. MINOR TWEAKS TO HRLY AND POP GRIDS. UPDATE
OUT MOMENTARILY.
&&
.AVIATION...
ISSUED 1254 PM CDT SUN APR 1 2012
NEW MODELS COMING IN DRY THRU TAF PD. SWRLY/WRLY WINDS COMING
AROUND TO SRLY THEN EASTERLY AFTER 06Z TONIGHT AS WEAK BOUNDARY
MOVES BACK NORTH. CU THRU THE AFTERNOON SCT OUT AS LLVL STRATUS
DEVELOPS WITH MOISTURE TRAPPED IN BOUNDARY LAYER ON RH TIME
HEIGHTS. NOT DROPPING CIGS BELOW MVFR HOWEVER...AS PLENTY OF
SUNSHINE THIS AFTERNOON MAY COUNTER AND MIX OUT A BIT MORE
EFFECTIVELY THAN MOS HINTS.
HJS
&&
.PREV DISCUSSION...
ISSUED 300 AM CDT SUN APR 1 2012
SMALL MCS FORMED AS EXPECTED OVER EASTERN IOWA LATE IN THE
EVENING...AND HAS BEEN MOVING ACROSS THE NORTHERN CWA
OVERNIGHT...PRODUCING SEVERE HAIL AT TIMES. HAVE SEEN SOME
SHOWERS/STORMS AS FAR SOUTH AS LINCOLN AT 2 AM.
SHORT TERM...TODAY THROUGH TUESDAY...
LATEST HRRR MODEL...WHICH HAS A GOOD HANDLE ON THE ACTIVITY...
SHOWS MUCH OF THE RAIN SHOULD LARGELY BE OUT OF THE CWA BY
SUNRISE. WILL MAKE A LAST MINUTE DECISION ON HOW LONG TO LINGER IT
THIS MORNING. ONCE THAT CLEARS OUT...TEMPERATURES BECOME THE
PRIMARY FOCUS. STILL LOOKING FOR HIGHS IN THE 80S ACROSS THE
ENTIRE AREA...CLOSE TO THE DAILY RECORDS. HOWEVER...EVENING MODEL
RUNS SHOWING A FRONTAL BOUNDARY NEAR THE I-80 CORRIDOR WILL LIKELY
SLIP A BIT SOUTHWARD THIS AFTERNOON...DRIVEN BY A RATHER STIFF
NORTHEAST FLOW. IF IT SLIPS TOO FAR...THEN TEMPERATURES ACROSS THE
NORTHEAST CWA MAY END UP BEING COOLER THAN EXPECTED. WRF MODEL OUT
OF WFO CHICAGO HAS THE BOUNDARY ALMOST ALL THE WAY TO I-74 BY
6 PM. WILL NEED TO WATCH THIS CLOSELY DURING THE AFTERNOON.
BOUNDARY WILL PROBABLY REACH AT LEAST INTO PART OF THE CWA THIS
EVENING...BEFORE BEGINNING TO RETREAT. SAME PROBLEM EXISTS WITH
TEMPERATURES MONDAY AFTERNOON...DUE TO ITS POSITION. HAVE PULLED
HIGH TEMPERATURES DOWN A BIT NORTH OF I-74...BUT STILL GOING A FEW
DEGREES ABOVE GUIDANCE IN THAT AREA. REMAINDER OF THE CWA MORE
LIKELY TO REACH THE 85-90 DEGREE RANGE...AGAIN NEAR THE RECORDS.
TIMING OF COLD FRONTAL PASSAGE TUESDAY MORNING APPEARS TO HAVE
SLOWED A BIT FROM EARLIER RUNS...SO HAVE KEPT TEMPERATURES SOUTH
OF I-70 WARMER THAN PREVIOUSLY FORECAST...WITH LOWER 80S.
THREAT OF SHOWERS/STORMS TO CONTINUE INTO THE AFTERNOON WITH THE
BOUNDARY IN THE AREA.
LONG TERM...WEDNESDAY THROUGH SATURDAY...
STILL LOOKING TO BE MUCH COOLER THAN THE START OF THE WEEK...ALTHOUGH
STILL A BIT ABOVE NORMAL. FOCUS IN THIS PERIOD REMAINS WITH A
CUTOFF LOW WHICH WILL DEVELOP OVER THE SOUTHERN ROCKIES EARLY IN
THE WEEK. LONGER RANGE MODELS IN REASONABLE AGREEMENT WITH A TRACK
THAT TAKES IT SOUTH OF THE OHIO VALLEY...BUT WILL STILL SEE THE
RAIN SHIELD ON THE NORTHERN FLANK EXTEND WELL TO THE NORTH. HAVE
CUT BACK ON THE RAIN ACROSS THE NORTHERN CWA FOR WEDNESDAY/THURSDAY...
WITH THE PERSISTENT NORTHEAST FLOW BRINGING DRIER AIR INTO CENTRAL
ILLINOIS. MAINLY DRY CONDITIONS EXPECTED LATE IN THE WEEK...AS A
NARROW RIDGE OF HIGH PRESSURE MOVES INTO THE MISSISSIPPI VALLEY.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1122 AM CDT SUN APR 1 2012
.DISCUSSION...
1005 AM CDT
THE EARLY MORNING STORMS HAVE MOVED QUICKLY SOUTHEAST INTO
SOUTHERN INDIANA. IN THEIR WAKE...THEY HELPED TO SINK THE FRONTAL
BOUNDARY SOUTH TO NEAR INTERSTATE 88 AT AROUND 10 AM. TO THE
NORTH...WHERE STRATUS AND NORTHERLY WINDS PREVAIL...TEMPERATURES
HAVE BEEN BASICALLY FLAT LINE. WHILE SOME MIXING OUT OF THE
STRATUS MAY OCCUR LATE THIS MORNING...REINFORCING NORTHEAST COLD
AIR ADVECTION WILL EVOLVE AS A WEAK LOW SHIFTS EAST ALONG THE
FRONTAL BOUNDARY. THIS SCENARIO SHOULD ENABLE THE FRONT TO MOVE
SOUTH KEEPING TEMPERATURES COOLER TO THE NORTH...WITH PLACES
SEEING A FALL THIS AFTERNOON ESPECIALLY IN THE NEAR DOWNSTREAM OF
LAKE MICHIGAN. THE 01.12 NAM CAPTURES THIS TREND WELL...AND SEEMS
TO HAVE A DECENT HANDLE ON THE STRATUS EVOLUTION...HINTING AT LOW
CLOUDS ALONG AND IMMEDIATELY BEHIND THE BOUNDARY THROUGH THIS
AFTERNOON.
IT IS A TALE OF TWO DIFFERENT DAYS ACROSS THE CWA AS TO THE SOUTH
OF THE FRONT...TEMPERATURES ARE OFF TO THE RACES WITH MID 60S
ALREADY AT 10 AM IN PERU AND PONTIAC. A WARM-UP TO AROUND OR JUST
ABOVE 80 DEGREES STILL LOOKS WELL IN PLACE...ESPECIALLY SEEING
GUSTS TO AROUND 20 KTS ALREADY INDICATING GOOD MIXING AND
CONTINUED LOW- LEVEL WARM AIR ADVECTION. THE 12Z ILX RAOB HAD NEAR
1300 J/KG OF MUCAPE WHICH SHOULD BE A GOOD BASELINE FOR WHAT IS
SHIFTING OVER THE SOUTHERN FORECAST AREA AS IT CONTINUES TO WARM.
THIS LOOKS TO MAXIMIZE/POOL THIS AFTERNOON BETWEEN 1500 AND 2000
J/KG IN THE FAR SOUTH...BUT IN THE ABSENCE OF ANY PRONOUNCED
TRIGGER AND A QUICKLY WEAKENING LOW- LEVEL JET. THE WEAK SURFACE
CIRCULATION ALONG THE BOUNDARY MAY HELP TO INCREASE CONVERGENCE
SOME AS IT SHIFTS EAST THROUGH THE AFTERNOON. ALSO...AN ILL-
DEFINED SHORT WAVE RIPPLE IN EASTERN IA IS SHIFTING EAST. TOGETHER
IT MIGHT BE ENOUGH TO SPARK ISOLATED THUNDERSTORMS...GENERALLY
SOUTH OF U.S. HIGHWAY 24 THIS AFTERNOON. ABOUT ONE THIRD OF
EXPLICIT CONVECTIVE GUIDANCE LOOKED AT HAS THAT FORM OF SOLUTION.
INSTABILITY PROFILES ARE ENOUGH TO WARRANT MAINLY A HAIL THREAT IF
ANY STORM WERE TO SUSTAIN ITSELF.
MTF
//PREV DISCUSSION...
315 AM CDT
THIS MORNING HIGH PRESSURE OVER THE EASTERN GREAT LAKES REGION WILL
PUSH EASTWARD WITH FRONTAL BOUNDARY SLOWLY TRYING TO LIFT NORTHWARD
THROUGH THE EARLY MORNING HOURS. ONGOING ELEVATED CONVECTION ON NOSE
OF LOW LEVEL JET WILL CONTINUE TO PUSH SOUTHEAST ACROSS THE REGION
RIDING H5 HEIGHTS DOWN THE RIDGE ALONG THE INSTABILITY GRADIENT.
SEVERE THREAT THROUGH THE PREDAWN HOURS WILL REMAIN MARGINAL...BUT
LATEST RUC CONTINUES TO SHOW NEAR 1000 J/KG GENERALLY ALONG AND WEST
OF THE I39 CORRIDOR SUPPORTING AT LEAST SOME THREAT FOR HAIL. THREAT
SHOULD TAPER THROUGH DAYBREAK THIS MORNING AS LOW LEVEL JET VEERS
AND THETA E ADVECTION WEAKENS. MEANWHILE...WEAK AREA OF LOW
PRESSURE NEAR LAKE SUPERIOR WILL PUSH EAST INTO SOUTHEASTERN
ONTARIO BY EARLY THIS AFTERNOON. GUIDANCE SUGGESTS BAROCLINIC ZONE
WILL BE FARTHER SOUTH/WEST THAN ORIGINALLY ANTICIPATED THUS BUMPED
DOWN TEMPERATURES SLIGHTLY ACROSS THE AREA FOR THIS AFTERNOON. IN
ADDITION WINDS TURNING TO THE NORTHEAST BY MID MORNING IN RESPONSE
TO LOW MOVING ACROSS ONTARIO WILL LIMIT HIGH TEMPS ALONG THE LAKE
SHORE...WITH TEMPERATURES FALLING INLAND THROUGH THE AFTERNOON AS
MARINE LAYER SPREADS INLAND.
MONDAY...GUIDANCE CONTINUES TO STRUGGLE WITH PLACEMENT OF BAROCLINIC
ZONE/LOW PRESSURE. A LARGE TEMPERATURE SPREAD IS STILL EXPECTED TO
SET UP ACROSS THE CWA. MAJORITY OF GUIDANCE SHOWS SOUTHWEST PORTIONS
OF THE CWA TRYING TO REACHING THE 80 MARK...BUT WARMER TEMPERATURES
ARE NOW EXPECTED TO BE FARTHER WEST. ALSO HAD TO DROP TEMPERATURES
ALONG THE LAKE FRONT SEVERAL DEGREES AS LATEST GUIDANCE IN GENERAL
SUGGESTS 60S POSSIBLY EVEN 50S AS WE STAY UNDER SOUTHEAST FLOW
THROUGH THE DAY WITH WINDS OFF THE LAKE IN ILLINOIS. AM CONCERNED
TEMPS ARE STILL A LITTLE HIGH THOUGH FOR MONDAY ALONG THE ILLINOIS
SHORES.
TUESDAY THOUGH SATURDAY...COLD FRONT WILL SWEEP ACROSS THE REGION
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS.
BROAD AREA OF HIGH PRESSURE BUILDS ACROSS THE CANADIAN PRAIRIES EAST
TOWARDS THE GREAT LAKE REGION THROUGH THE END OF THE WEEK. NORTHERN
ILLINOIS AND NORTHWEST INDIANA WILL BE IN AREA OF NORTHERLY FLOW AND
EXPECT TO BE CLIPPED BY COOLER AIR ALOFT //H85 TEMPS FALLING TO
AROUND -3C THURSDAY// BEHIND THE COLD FRONT. SHOULD SEE PLENTY OF
SUNSHINE FOR THE LATTER HALF OF THE WEEK. TEMPERATURES WILL CONTINUE
TO RUN SLIGHTLY ABOVE NORMAL...BUT SHOULD BE MORE SEASONABLE WITH
HIGHS IN THE UPPER 50S TO LOW 60S AND LOWS IN THE UPPER 30S TO LOW
40S. BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* FOG WITH VIS OF 4-5SM THROUGH LATE MORNING...WITH CONDITIONS
IMPROVING BY MID DAY.
* VFR CEILINGS SCATTERING OUT BY MID AFTERNOON.
* NORTHEAST WINDS STEADILY INCREASING THROUGHOUT THE DAY...WITH
SOME GUSTS POSSIBLE IN THE AFTERNOON.
RODRIGUEZ
//DISCUSSION...UPDATED 12Z...
EXPECT SOME RATHER VARIABLE CONDITIONS THROUGH EARLY AFTERNOON IN
TERMS OF WINDS/CIGS/VSBY. CURRENTLY...SHRA/TSRA ACTIVITY ACROSS
FAR NE IL IS MOVING INTO NW IN AND WILL EXIT TO THE EAST OF GYY
TOWARD 14Z. NEXT CONCERNS ARE RELATED TO WEAK LOW PRESSURE WHICH
WILL MOVE ALONG A FRONTAL BOUNDARY EXTENDING FROM NEAR KCID TO
KRPJ TO JUST NORTH OF KPWK THIS MORNING. THIS FRONT IS EXPECTED TO
SAG SOUTHWARD THROUGH THE MORNING BRINGING WINDS TO THE NORTHEAST
ACROSS THE CHI AND NW IN TERMINALS...WITH RFD ALREADY SEEING NE
WINDS. AS THE FRONT MOVES WINDS WILL LIKELY BECOME LIGHT AND
VARIABLE WITH A SOUTH TO WEST DIRECTION. GIVEN THE RAINFALL THIS
MORNING AND THE LIGHT WIND REGIME EXPECT THAT MVFR VSBY WILL
PREVAIL...WITH SOME IFR TOWARDS DPA AND RFD...THROUGH AT LEAST MID
MORNING AND POSSIBLY LONGER. IN ADDITION...FORECAST SOUNDINGS
CONTINUE TO SHOW DEVELOPMENT OF MVFR LEVEL STRATUS DECK BY MIDDAY
WHICH WOULD THEN SCATTER LATER THIS AFTERNOON. THIS SEEMS
PLAUSIBLE GIVEN THE SHIFT TO A COOLER NORTHEASTERLY FLOW OFF THE
LAKE AND THE ABUNDANT LOW LEVEL MOISTURE ALREADY IN PLACE. THERE
IS A CHANCE THAT MIST/HAZE WILL CONTINUE THROUGH THE AFTERNOON AS
WELL BUT CONFIDENCE IS LOW.
NORTHEAST WINDS WILL TURN EASTERLY TONIGHT AS RIDGING BUILDS TO
THE EAST AND LOW PRESSURE TAKES SHAPE ACROSS THE CENTRAL PLAINS.
VFR SHOULD PREVAIL BUT SOME MVFR VSBY REDUCTION IS POSSIBLE LATE.
WINDS WILL THEN TURN MORE SOUTHEASTERLY MONDAY MORNING.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE OF FOG/VIS TRENDS AND TIMING IMPROVEMENT.
* MEDIUM CONFIDENCE WITH CEILING TRENDS THROUGH THE AFTERNOON.
* HIGH CONFIDENCE IN WIND SPEED AND DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...VFR WITH CHANCE TSRA.
TUESDAY...VFR WITH CHANCE SHRA/TSRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
MDB
&&
.MARINE...
210 AM CDT
HIGH PRESSURE OVER OHIO EXTENDS NORTHEASTWARD ACROSS THE ST.
LAWRENCE VALLEY THIS MORNING WHILE A COMPLEX SERIES OF WEAK LOW
PRESSURE SYSTEMS ARE NOTED FROM LAKE SUPERIOR INTO THE MID
MISSISSIPPI RIVER VALLEY...WITH BETTER ORGANIZED LOW PRESSURE IN THE
LEE OF THE ROCKIES. ONE LOW...OVER LAKE SUPERIOR...WILL MOVE
SOUTHEASTWARD TODAY AND MOVE OFF THE EAST COAST THIS EVENING WHERE
IT WILL DEEPEN. ANOTHER AREA OF LOW PRESSURE OVER WESTERN IOWA
WILL DRIFT EAST WITH A COOL FRONTAL BOUNDARY SETTING UP FROM THE
FIRST LOW INTO THIS WEAKER LOW. HIGH PRESSURE WILL THEN SPREAD
SOUTHWARD FROM HUDSON BAY AND INTO THE GREAT LAKES BEHIND THE
LOW. AS A RESULT OF THIS FAIRLY COMPLEX PATTERN SOUTHERLY WINDS IN
PLACE ACROSS LAKE MICHIGAN THIS MORNING WILL TURN NORTHEASTERLY
TODAY AND EASTERLY TONIGHT...BEFORE BECOMING SOUTHEAST FOR MONDAY.
IT APPEARS THAT THERE WILL BE SEVERAL PERIODS OF STRONGER WINDS
FROM TONIGHT THROUGH TUESDAY AS THE PRESSURE GRADIENT MODULATES
BETWEEN SYSTEMS. THE FIRST INCREASE SHOULD OCCUR TONIGHT ACROSS
CENTRAL AND SOUTHERN PARTS OF THE LAKE WITH GUSTS TO AROUND 25 KT
EXPECTED. SPEEDS LOOK TO EASE SOMEWHAT MONDAY BEFORE INCREASING
AGAIN MONDAY EVENING THEN DROPPING OFF TUESDAY MORNING AS A LOW
PASSES JUST TO THE SOUTH. THE GRADIENT TIGHTENS BEHIND THE LOW
TUESDAY AFTERNOON AS STRONG HIGH PRESSURE SPREADS INTO THE UPPER
MISSISSIPPI RIVER VALLEY. THIS LOOKS TO BE THE PERIOD OF STRONGEST
WINDS WITH 30 KT POSSIBLE FROM THE NORTH. THE HIGH THEN GRADUALLY
SPREADS EASTWARD KEEPING ITS INFLUENCE OVER THE LAKE THROUGH THE
END OF THE WEEK. LOWS WILL PASS TO THE EAST AND SOUTH OF THE LAKE
SO PERIODS OF SLIGHTLY STRONGER WINDS WILL BE POSSIBLE DESPITE THE
PRESENCE OF THE HIGH...BUT HIGHEST SPEEDS LOOK TO BE UNDER 20 KTS
OR SO FROM MID WEEK ONWARD.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
527 PM EDT SUN APR 1 2012
.UPDATE...
ISSUED AT 526 PM EDT SUN APR 1 2012
LAST OF THE MCS IS FINALLY DEPARTING OFF TO OUR SOUTHEAST...WITH
SKIES QUICKLY CLEARING ACROSS THE AREA THIS EVENING. THIS SHOULD
ALLOW FOR MOST PLACES TO REACH THEIR HIGH FOR THE DAY OVER THE NEXT
HOUR OR TWO AS TEMPERATURES QUICKLY SHOOT UP WITH THE SUNSHINE. WITH
STABLE AREA ENTRENCHED ACROSS EASTERN KENTUCKY STRETCHING NORTH INTO
SOUTHERN OHIO...ANY DEVELOPING MCS WILL BE AT LEAST 3 TO 6 HOURS
BEFORE IT IMPACTS OUR NECK OF THE WOODS. WITH THIS IN MIND...HAVE
GONE AHEAD AND DELAYED THE BETTER PRECIPITATION CHANCES UNTIL AFTER
04Z (MIDNIGHT). THE HRRR SEEMS TO HAVE THE BEST TIMING AND HANDLING
ON THE SITUATION WITH ALL OTHER MODELS TO AGGRESSIVE ON REDEVELOPING
ACTIVITY IN THE STABLE BOUNDARY LAYER OVER THE NEXT FEW HOURS. NO
INDICATION THIS WILL HAPPEN AS CLOUDS ARE FEW AND FAR BETWEEN.
THUS...THE HRRR INDICATION OF LATER CONVECTION SEEMS LIKE THE WAY TO
GO UNTIL SOMETHING SHOWS ME OTHERWISE. STILL GOING TO BE MAINLY A
HAIL THREAT...ESPECIALLY GIVEN MOST OF THE ACTIVITY SHOULD BE
ELEVATED. WILL CONTINUE TO MONITOR FOR ADDITIONAL UPDATES AS EVENTS
UNFOLD OVER THE NEXT 3 TO 6 HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 359 PM EDT SUN APR 1 2012
THE LEFTOVER MCS IS FINALLY MAKING AN EXIT ACROSS THE AREA...WITH
THE BACK EDGE LIKELY TO EXIT BETWEEN 4 AND 5 PM. HIGHS HAVE REALLY
BEEN HAMPERED BY THE CLOUD COVER...BUT DO EXPECT A LATE IN THE DAY
PUSH...WITH SOME LOW TO MID 70S FOUND WEST OF I-75...WHILE MOST
OTHERS RANGE FROM THE MIDDLE 60S TO AROUND 70 DEGREES.
THE MODELS CONTINUE TO PLAY UP ANOTHER THUNDERSTORM COMPLEX TO
DEVELOP ACROSS THE UPPER OHIO BASIN LATER THIS EVENING IN RESPONSE TO
A DIGGING SHORT WAVE TROUGH WHICH WILL NOSE IN FROM THE SAINT
LAWRENCE RIVER VALLEY OVERNIGHT. THE MODEL TIMING OF THIS ACTIVITY IF
IT DOES HAPPEN...SEEMS A BIT FAST...AS THERE IS NOTHING POPPING YET
IN NORTHERN OHIO. WILL CONTINUE TO ALLOW FOR SOME GOOD CHANCE POPS
LATER TONIGHT FOR THE NORTHEAST HALF OF THE AREA...SCALING BACK
QUICKLY TO SLIGHT CHANCE TO THE SOUTHWEST.
AS FOR THE SEVERE THREAT...HAVE EVEN LESS CONFIDENCE IN THIS...AS WE
HAVE BEEN STABILIZED BY THE STORMS THAT TOOK PLACE THIS AFTERNOON.
WILL HAVE TO WAIT AND SEE HOW THE ATMOSPHERE RECOVERS TONIGHT...WITH
AT LEAST LIGHT SOUTHWEST WINDS ADVECTING SOME LOW LEVEL
MOISTURE...WHICH MAY RECHARGE US SOMEWHAT.
THIS COMPLEX...WILL HELP DRAG A BACKDOOR COOL FRONT THROUGH THE AREA
DURING THE DAY TOMORROW. BESIDES SOME LEFTOVER CONVECTION IN THE
MORNING...DO NOT EXPECT ANY RE-FIRING LATER IN THE DAY...WITH THE
MODEL SOUNDINGS SHOWING SOME DECENT CAPPING. THE FRONT WILL THEN MOVE
BACK TO THE NORTHEAST MONDAY NIGHT AS A WARM FRONT...PERHAPS KICKING
OFF SOME ISOLATED CONVECTION AS THIS OCCURS.
AS FOR TEMPERATURES...ABOVE NORMAL READINGS WILL CONTINUE...ALTHOUGH
READINGS HAVE COME IN A BIT COOLER FOR MONDAY WITH A LITTLE MORE
COOLER AND DRIER AIR INTRUSION...SO 70S WILL MOST LIKELY BE THE RULE
FOR MOST LOCATIONS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 359 PM EDT SUN APR 1 2012
A RATHER COMPLEX AND SOMEWHAT PROGRESSIVE PATTERN IS ANTICIPATED
DURING THE LONG TERM PERIOD. MOST OF THE TIME THE MAIN BAND OF
WESTERLIES ARE EXPECTED TO RESIDE TO OUR WEST...NORTH OR NORTHEAST
WITH UPPER LEVEL RIDGING POSSIBLY DOMINATING DURING TWO DISTINCT
PERIODS...WITH THE HIGHEST CHANCE OF THIS LATE IN THE PERIOD.
OVERALL...MODELS ARE IN REASONABLY GOOD AGREEMENT WITH THE PATTERN
WITH SOME DIFFERENCES LATER IN THE PERIOD AND SOME TIMING
DIFFERENCES FROM INDIVIDUAL MODEL RUN TO MODEL RUN.
EARLY ON...A WARM FRONT WILL BE MOVING NORTHEAST AND POSSIBLY EXIT
NORTHEAST OF THE AREA BY TUESDAY AFTERNOON OR EVENING. MODELS
GENERALLY DEVELOP PRECIP ONLY OVER THE EASTERN HALF OF THE CWA EARLY
IN THE PERIOD...WITH A POSSIBLE PERIOD OF SHORTWAVE RIDGING/DRY
SLOTTING OCCURRING BEFORE A COLD FRONT APPROACHES LATE IN THE DAY OR
TUE NIGHT.
THIS COLD FRONT WILL DROP SLOWLY SOUTH FROM TUE NIGHT INTO
WED...WITH THE MODEL CONSENSUS TAKING THE BOUNDARY SOUTH OF THE CWA
BY WED EVENING. HOWEVER...THE BOUNDARY SHOULD THEN STALL FOR A
TIME...THOUGH THE MODELS VARY IN HOW LONG DUE TO DIFFERENCES IN
HANDLING AN UPPER LOW THAT WILL MEANDER SOUTH OF A NORTHERN
PLAINS/NORTHERN GREAT LAKES RIDGE FROM THE SOUTHERN ROCKIES ACROSS
THE PLAINS AND MS VALLEY AND ON INTO THE EASTERN CONUS...POSSIBLY
ACROSS THE TN VALLEY AND INTO THE SOUTHERN APPALACHIANS AND THEN OFF
THE EASTERN SEABOARD. THIS UPPER LOW IS EXPECTED TO FOLLOW THIS
MEANDERING PATH FROM THE START OF THE PERIOD ON TUE THROUGH FRI.
AS MENTIONED BY THE PREVIOUS FORECASTER....BUT FRI IT SHOULD FINALLY
GET PICKED UP BY A TROUGH TO ITS NORTHEAST AND THIS SHOULD THEN TAKE
IT OUT TO SEA. THEREAFTER...THE MODEL CONSENSUS IS FOR THE UPPER
LEVEL RIDGE TO BUILD IN AND DOMINATE THAT LAST TWO TO TWO AND A HALF
DAYS OF THE PERIOD.
AS FOR POPS...WENT WITH SLIGHT CHANCE TO CHANCE POPS EARLY ON TUE
WITH THE WARM FRONT AND THEN INCREASED POPS LATE ON TUE INTO TUE
EVENING IN ADVANCE OF THE APPROACHING COLD FRONT AND SHORTWAVE THAT
THE MODEL CONSENSUS TAKES ACROSS THE OH VALLEY REGION OR THE CWA ON
TUE NIGHT. THE BOUNDARY SHOULD CONTINUE SLIPPING SOUTH ON WED AND
CONTINUED CHANCE POPS DURING WED...BUT GRADUALLY LOWERED POPS IN THE
NORTH FARTHER AWAY FROM THE BOUNDARY. A SFC LOW MAY DEVELOP ALONG
THE BOUNDARY AS THE UPPER LOW APPROACHES AROUND MIDWEEK AND SLOW THE
SOUTHWARD PROGRESS OF THE FRONT AND HOLD IN CHANCES FOR ISOLATED TO
SCATTERED CONVECTION AS THE SFC LOW AND UPPER SYSTEM PROBABLY TRACK
JUST TO OUR SOUTH ACROSS THE TN VALLEYS. ONCE THE UPPER SYSTEM
TRACKS EAST...PRECIP CHANCES WILL DIMINISH LATE THU NIGHT OR FRI.
FOR NOW THE END OF THE FORECAST IS EXPECTED TO BE DRY...WITH UPPER
LEVEL RIDGING DOMINATING. WITH THIS RIDGE...OPTED TO FAVOR THE ECMWF
RUNS.
TEMPERATURES SHOULD BE WARMEST AND MOST ABOVE NORMAL ON TUESDAY AND THEN
MORE MODEST DEPARTURES OF ABOUT 5 DEGREES ABOVE NORMAL AT THE END OF
THE PERIOD. OVERNIGHT LOWS SHOULD AVERAGE AT LEAST 5 DEGREES ABOVE
NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 158 PM EDT SUN APR 1 2012
A COMPLEX OF SHOWERS AND THUNDERSTORMS WILL GRADUALLY WEAKEN AND EXIT
OFF TO THE SOUTHEAST IN THE NEXT FEW HOURS...ALLOWING FOR AT LEAST
TEMPORARILY IMPROVING CONDITIONS AT SME AND LOZ. VFR CONDITIONS WILL
RETURN...ALTHOUGH THERE WILL BE A RENEWED THREAT OF CONVECTION THIS
EVENING AND INTO THE OVERNIGHT HOURS TONIGHT...HOWEVER WILL ONLY
MAINTAIN THE VCTS WORDING FOR NOW...AS CONFIDENCE REMAINS LOW IN
WHERE AND WHEN THE CONVECTION WILL OCCUR. RIGHT NOW...IT DOES APPEAR
THAT THE BETTER THREAT WILL BE ALONG AND EAST OF A LINE FROM
MOREHEAD...TO JACKSON...TO HARLAN.
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...GEOGERIAN
LONG TERM....JP
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
412 PM EDT SUN APR 1 2012
.SYNOPSIS...
A COLD FRONT MOVING SOUTHEASTWARD THROUGH THE UPPER OHIO VALLEY
TONIGHT WILL SPAWN SHOWERS AND SCATTERED EVENING THUNDERSTORMS.
CANADIAN HIGH PRESSURE WILL THEN PROVIDE DRY SEASONABLE WEATHER MONDAY.
A LOW PRESSURE SYSTEM, COMING SOUTHEAST FROM MONTANA, WILL BRING
SHOWERS AND SCATTERED THUNDERSTORMS TUESDAY AFTERNOON AND NIGHT.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
BLEND OF RECENT RADAR DATA AND HRRR MODEL OUTPUT SHOW A SLOWER
DEVELOPMENT OF THE COLD FRONTAL SHOWER BAND ACROSS THE I-80
CORRIDOR. THIS MAY BE DUE TO SURFACE LAYER DRYNESS WHICH WOULD
INHIBIT INSTABILITY. THIS WOULD LIKEWISE INHIBIT THUNDERSTORM
DEVELOPMENT THIS EVENING, BUT AT THIS JUNCTURE HAVE NOT OMITTED
MENTION OF SCATTERED EVENING THUNDERSTORMS.
CONCUR WITH RECENT HRRR THAT ANY REMAINING SHOWERS WILL HAVE
EXITED SOUTH INTO CENTRAL WEST VIRGINIA BY LATE TONIGHT.
FORECASTED TEMPERATURES TONIGHT USING BLEND OF HRRR, LAMP, AND NAM
MODEL OUTPUT WHICH YIELDED VALUES EITHER NEAR OR SLIGHTLY WARMER
THAN NORMAL.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
BLEND OF RECENT SREF MODEL OUTPUT SHOWS CANADIAN HIGH PRESSURE
PROVIDING SUBSIDENCE AND DRYING MONDAY. HENCE EXPECT SUNSHINE TO
BE PREVALENT.
LOW PRESSURE SYSTEM, COMING SOUTHEAST FROM MONTANA, WILL NEXT SPREAD
CLOUDS EASTWARD ACROSS THE UPPER OHIO VALLEY STARTING LATE MONDAY
NIGHT. HAVE MAINTAINED A FORECAST OF A CHANCE OF SHOWERS AND
THUNDERSTORMS TUESDAY AFTERNOON AND NIGHT WITH THE EASTWARD PASSAGE
OF THE LOW PRESSURE CENTER ACROSS THE UPPER OHIO VALLEY.
HIGH PRESSURE WILL FOLLOW WITH DRY CONDITIONS WEDNESDAY.
FORECASTED TEMPERATURES, USING CONSENSUS OF SREF, GFS AND NAM
GUIDANCE, TO BE NEAR NORMAL MONDAY, 7 TO 10 DEGREES WARMER THAN
NORMAL TUESDAY, AND NO MORE LIKE 3 TO 5 DEGREES WARMER THAN NORMAL
DAYTIME WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
DRY WEATHER SHOULD PREVAIL ACROSS THE UPPER OHIO VALLEY REGION INTO
THE WEEKEND AS A LARGE AREA OF HIGH PRESSURE SLIDES SOUTHEAST ACROSS
THE GREAT LAKES.
A SLOW MOVING LOW PRESSURE SYSTEM WILL TRACK EASTWARD FROM THE LOWER
MS VALLEY TO OFF SOUTHEAST COAST LATE IN THE WEEK. THE BULK OF
ASSOCIATED MOISTURE IS PROGGED TO REMAIN SOUTH OF THE FORECAST AREA.
HPC GUIDANCE SHOWS THE NEXT COLD FRONT APPROACHING FROM THE WEST
WITH A CHANCE OF SHOWERS LATE SUNDAY.
TEMPERATURES ARE FORECAST TO BE NEAR NORMAL THROUGH FRIDAY...THEN
WARMING TO AROUND 10 DEGREES ABOVE NORMAL DURING THE WEEKEND.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
A SHORTWAVE TROUGH WILL CONTINUE TO PLUNGE SOUTHEAST OFF THE MID
ATLANTIC COAST EARLY TONIGHT. THE ASSOCIATED WEAK SURFACE REFLECTION
AND COLD FRONT WILL MOVE ACROSS THE TERMINALS EARLY TONIGHT.
SCATTERED SHOWERS WITH BRIEF MVFR RESTRICTIONS ARE EXPECTED AS THE
SYSTEM MOVES THROUGH...FOLLOWED BY GENERALLY MVFR CEILINGS BEHIND
THE FRONT OVERNIGHT.
CONDITIONS ARE FORECAST TO IMPROVE TO VFR BY LATE MONDAY MORNING AS
A SURFACE RIDGE BUILDS IN FROM THE NORTH.
SOUTHWEST SURFACE WINDS WILL BECOME NORTHWEST AROUND 10KT BEHIND THE
FRONTAL BOUNDARY TONIGHT.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...
ANOTHER SHORTWAVE TROUGH AND COLD FRONT WILL BRING SCATTERED SHOWERS
AND THE POTENTIAL FOR RESTRICTIONS LATE TUESDAY INTO TUESDAY NIGHT.
A RETURN TO PREDOMINATELY VFR WEATHER IS EXPECTED WEDNESDAY THROUGH
FRIDAY AS HIGH PRESSURE SLIDES ACROSS THE REGION.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
307 PM EDT SUN APR 1 2012
.SYNOPSIS...
A COLD FRONT WILL PASS THROUGH THE REGION TONIGHT BEFORE HIGH
PRESSURE BUILDS OVERHEAD MONDAY THROUGH MONDAY NIGHT. HIGH PRESSURE
WILL MOVE OFF THE COAST TUESDAY AND ANOTHER COLD FRONT WILL IMPACT
THE REGION WEDNESDAY. HIGH PRESSURE IS EXPECTED TO BUILD OVERHEAD
LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
CU/STRATOCU FIELD EAST OF THE BLUE RIDGE WAS BREAKING
UP/SCATTERING THIS AFTERNOON. THIS WILL ALLOW FOR PARTIAL
SUNSHINE THIS AFTERNOON BEFORE THE NEXT BATCH OF CLOUDS ROLLS IN BY
EARLY EVENING.
HAVE A FEW SHOWERS MAKING THEIR WAY INTO CENTRAL PENNSYLVANIA AT 2
PM. SOUTHERN EDGE MAY CLIP MARYLAND COUNTIES ALONG THE MASON DIXON
LINE THIS AFTERNOON BUT PER HRRR GUIDANCE THE BULK OF THESE STAY TO
THE NORTH/NORTHEAST OF THE CWA THIS AFTERNOON.
HOWEVER...AS LOW PRESSURE AND A COLD FRONT APPROACH FROM THE
WEST...EXPECT A NEW AREA OF SHOWERS TO DEVELOP AND PRESS SOUTH
THROUGH THE EVENING/OVERNIGHT HOURS. WRF-ARW SEEMS A LITTLE ON THE
FAST SIDE...AND PREFER THE TIMING/EVOLUTION INDICATED BY THE HRRR
WHICH HAS GENERAL SUPPORT FROM THE NAM/GFS/SREFS. HAVE INCREASED
POPS TO CATEGORICAL ACROSS THE NORTHERN HALF OF THE CWA...WITH HIGH
CHANCE TO LIKELY ACROSS THE SOUTHERN REACHES OF THE CWA.
GIVEN TIME OF DAY/RELATIVE LACK OF INSTABILITY...HAVE LOW CONFIDENCE
IN THUNDERSTORMS. HAVE ALLOWED FOR ISOLATED EVENING THUNDER ACROSS
THE WEST WHERE SUNSHINE THIS AFTERNOON HAS BEEN LONGER AND WHERE
THERE MAY BE A LITTLE INSTABILITY. FURTHER EAST...ONLY P-TYPE
INCLUDED IS SHOWERS.
LOW PRESSURE SHOULD BE OFF THE COAST AND THE COLD FRONT SOUTH OF THE
AREA BY AROUND 10Z MONDAY. SKIES WILL CLEAR OUT BEHIND THE
FRONT...PAVING THE WAY FOR PLENTY OF SUNSHINE. HOWEVER WITH SUNSHINE
MIXING WILL BE DECENT AND EXPECT WIND GUSTS AOA 25 MPH. LEANED
TOWARD THE WARMER SET OF MOS FOR MAX T ON MONDAY...WHICH RANGES FROM
LOWER 60S ACROSS NORTHEAST MARYLAND TO UPPER 60S TOWARD THE CENTRAL
VA FOOTHILLS.
&&
.SHORT TERM /MONDAY NIGHT/...
SURFACE HIGH PRESSURE WILL BUILD OVERHEAD MONDAY NIGHT...CAUSING DRY
AND SEASONABLY CHILLY CONDITIONS. LIGHT WINDS...DRY AIR AND MAINLY
CLEAR SKIES WILL PROVIDE A GOOD SETUP FOR RADIATIONAL COOLING. MIN
TEMPS WILL RANGE FROM THE LOWER AND MIDDLE 30S ACROSS NORTHERN
MARYLAND INTO EASTERN WEST VIRGINIA AND NORTHERN VIRGINIA...TO THE
LOWER AND MIDDLE 40S IN DOWNTOWN WASHINGTON/BALTIMORE AND LOWER
SOUTHERN MARYLAND.
AREAS OF FROST ARE POSSIBLE ACROSS PORTIONS OF THE NORTHERN
MARYLAND...EASTERN WEST VIRGINIA AND NORTHERN VIRGINIA LATE MONDAY
NIGHT. A FROST ADVISORY MAY BE NEEDED.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL MOVE OFF THE COAST TUESDAY AND A RETURN FLOW FROM
THE SOUTH WILL USHER IN MILD CONDITIONS. MAX TEMPS WILL RANGE FROM
THE MID 60S ACROSS NORTHEASTERN MARYLAND TO THE MIDDLE 70S ACROSS
CENTRAL VIRGINIA. WARM AND MOIST AIR WILL LEAD TO LIMITED
INSTABILITY ACROSS THE POTOMAC HIGHLANDS AND SHENANDOAH VALLEY.
SCATTERED SHOWERS/T-STORMS ARE POSSIBLE ACROSS THESE AREAS LATE IN
THE DAY.
A COLD FRONT WILL PASS THROUGH THE AREA TUESDAY NIGHT INTO
WEDNESDAY. A FEW SHOWERS ARE POSSIBLE ALONG AND AHEAD OF THE COLD
FRONT. THE BEST CHANCE FOR PRECIPITATION WILL BE ACROSS CENTRAL
VIRGINIA AND LOWER SOUTHERN MARYLAND WEDNESDAY AFTERNOON.
HIGH PRESSURE WILL BUILD IN BEHIND THIS SYSTEM WEDNESDAY NIGHT
THROUGH THURSDAY...BRINGING DRY AND SEASONABLE CONDITIONS. A STORM
SYSTEM WILL PASS BY TO OUR SOUTH THURSDAY NIGHT AND FRIDAY. AS OF
NOW IT APPEARS THAT IT WILL BE TOO FAR TO OUR SOUTH TO HAVE A
SIGNIFICANT IMPACT ON OUR WEATHER...BUT THE CERTAINTY REMAINS LOW
THIS FAR OUT. HIGH PRESSURE WILL RETURN NEXT WEEKEND BEHIND THIS
SYSTEM.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
MAINLY VFR CU/STRATOCU WILL CONTINUE TO BREAK UP THIS AFTERNOON
BEFORE CLOUDS ROLL BACK IN THIS EVENING. LOW PRESSURE/FRONT WILL
BRING THE LIKELIHOOD OF SHOWERS TONIGHT DURING A SEVERAL HOUR
WINDOW. TIMING FROM HRRR MODEL LOOKS REASONABLE. INCLUDED MVFR
RESTRICTIONS IN SHOWERS. WINDS SHIFT TO THE NORTHWEST OVERNIGHT AND
BECOME GUSTY. GUSTS AOA 25 KT ARE EXPECTED ON MONDAY BEFORE
DIMINISHING LATE.
HIGH PRESSURE WILL BUILD OVER THE TERMINALS MONDAY NIGHT BEFORE
MOVING OFF THE COAST TUESDAY. VFR CONDITIONS ARE EXPECTED DURING
THIS TIME. A COLD FRONT WILL BRING THE CHANCE FOR SHOWERS TUESDAY
NIGHT AND WEDNESDAY. THE TIMING OF THE FRONTAL PASSAGE REMAINS
UNCERTAIN THIS FAR OUT...BUT IF THE FRONTAL PASSAGE IS SLOW ENOUGH
THEN THUNDERSTORMS ARE POSSIBLE WEDNESDAY AFTERNOON.
HIGH PRESSURE WILL RETURN FOR LATE IN THE WEEK.
&&
.MARINE...
WILL HAVE TO WATCH SOUTHERLY FLOW THIS EVENING. WINDS HAVE REMAINED
IN CHECK /AROUND 10 KT/ SO FAR THIS AFTERNOON...BUT CHANNELLING THIS
EVENING COULD BRING WINDS CLOSE TO SCA THRESHOLDS UP THE BAY. HIGHER
CONFIDENCE EXISTS IN SCA CONDITIONS WITH A FROPA/WIND SHIFT TO THE
NORTHWEST TONIGHT AND CONTINUING INTO MONDAY.
HIGH PRESSURE WILL BUILD OVER THE WATERS MONDAY NIGHT BEFORE MOVING
OFF THE COAST TUESDAY. NORTHWEST WINDS AHEAD OF THE HIGH WILL GUST
PAST SCA CRITERIA CROSS THE MIDDLE PORTION OF THE BAY AND LOWER
TIDAL POTOMAC RIVER. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THESE
AREAS. WINDS WILL DIMINISH TOWARD TUESDAY MORNING AS HIGH PRESSURE
BUILDS OVERHEAD.
A RETURN FLOW WILL DEVELOP AROUND THE DEPARTING HIGH TUESDAY. A COLD
FRONT WILL PASS THROUGH THE WATERS LATE TUESDAY NIGHT INTO
WEDNESDAY. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR PORTIONS OF THE
WATERS DURING THIS TIME. HIGH PRESSURE WILL BUILD IN BEHIND THE
FRONT LATE IN THE WEEK. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR
PORTIONS OF THE WATERS THURSDAY.
&&
.TIDES/COASTAL FLOODING...
WILL CONTINUE COASTAL FLOOD ADVISORY THROUGH HIGH TIDE TIMES IN
COUNTIES ADJACENT TO THE UPPER BAY THIS AFTERNOON. AT 2
PM...ANNAPOLIS REMAINED ABOUT 2.5 FT MLWW BUT WILL BE ON THE WAY
DOWN OVER THE NEXT COUPLE OF HOURS. BIG QUESTION IS WHAT OCCURS ON
THE OVERNIGHT HIGH TIDE CYCLE. THERE IS THE CHANCE THAT ANOMALIES
MAY REMAIN STEADY AND IF THAT IS THE CASE THE COASTAL FLOOD ADVISORY
MAY NEED TO BE EXTENDED FOR THE NEXT HIGH TIDE CYCLE BEFORE
NORTHWEST WINDS DRIVE WATER OUT OF THE BAY OVERNIGHT INTO MONDAY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...COASTAL FLOOD ADVISORY UNTIL 7 PM EDT THIS EVENING FOR MDZ007-
011-014-018.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 AM TO 8 PM EDT MONDAY FOR ANZ530-
531-535-536-538-539.
SMALL CRAFT ADVISORY FROM 2 AM MONDAY TO 2 AM EDT TUESDAY FOR
ANZ532>534-537-540>543.
&&
$$
SYNOPSIS...BPP/BJL
NEAR TERM...BPP
SHORT TERM...BJL
LONG TERM...BJL
AVIATION...BPP/BJL
MARINE...BPP/BJL
TIDES/COASTAL FLOODING...BPP
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
347 PM EDT SUN APR 1 2012
.SYNOPSIS...
ISSUED AT 347 PM EDT SUN APR 1 2012
A STALLED FRONT WILL BRING SOME ISOLATED SHOWERS THIS EVENING.
FAIR WEATHER IS EXPECTED FOR MONDAY THEN SOME SHOWERS AND AN
ISOLATED THUNDERSTORM IS POSSIBLE MONDAY NIGHT AS LOW PRESSURE
MOVES JUST SOUTH OF LOWER MICHIGAN. CANADIAN HIGH PRESSURE WILL
BUILD IN FOR WEDNESDAY THROUGH THE END OF THE WEEK WITH FAIR
WEATHER AND FROSTY OVERNIGHT LOWS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 347 PM EDT SUN APR 1 2012
BANDS OF LIGHT OVERRUNNING SHOWERS ACROSS NORTHERN WISCONSIN WILL
BE MOVING INTO THE FORECAST AREA THROUGH THE EVENING. MOST OF
THESE SHOWERS ARE LIGHT AND SOME OF THE RAIN IS EVAPORATING BEFORE
REACHING THE GROUND...SO SLIGHT CHANCE POPS AND ISOLATED WORDING
SHOULD COVER IT. HRRR RUC HAS HAD A GOOD HANDLE ON THIS THROUGH
THE DAY...SO FOLLOWED IT FOR POPS OVERNIGHT.
AFTER A BREAK IN THE PRECIP...MORE SHOWERS SHOULD MOVE IN MONDAY
EVENING AS SFC LOW APPROACHES. SOME ELEVATED INSTABILITY EXISTS
BUT IT IS MARGINAL...SO WENT WITH ISOLATED THUNDER CHANCES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 335 PM EDT SUN APR 1 2012
LOW PRESSURE IS EXPECTED TO BE SLIDING EAST OVER THE LOWER GREAT
LAKES ON TUESDAY. IT STILL LOOKS LIKE SOME POTENTIAL FOR STRONG
STORMS WILL HAIL...ESPECIALLY EARLY IN THE DAY...AND MAINLY ALONG
AND SOUTH OF I-96. SYSTEM LOOKS A BIT SLOWER NOW...SO HAVE POPS
GOING THROUGHOUT THE DAY.
VERY DRY AIR FOLLOWS THE SYSTEM BY TUESDAY EVENING WITH CLEARING
SKIES. COULD BE THE THREAT OF FROST BY WEDNESDAY MORNING...BUT
THIS SHOULD BE PATCHY OVER INLAND AREAS AS THE PRESSURE GRADIENT
SHOULD STILL CAUSE SOME MIXING THROUGH THE NIGHT. LOOKS LIKE THE
BEST CHANCE OF FROST WILL COME LATE WEDNESDAY NIGHT AND LATE
THURSDAY NIGHT AS THE SURFACE RIDGE AXIS WILL BE NEARBY GIVING US
LIGHTER WINDS AND SINKING TEMPS TO THE LOW TO MID 30S IN MANY
LOCATIONS.
NEXT CHANCE OF RAIN SHOULD NOT COME UNTIL SATURDAY NIGHT INTO
SUNDAY. STILL SOME UNCERTAINTY IN THIS GIVEN THE STRONG RIDGE TO
OUR EAST. BUT GENERAL GUIDANCE CONSCIENCE SHOWS A FRONT COMING
THROUGH ON SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED
AT 256 PM EDT SUN APR 1 2012
MVFR IN HAZE AND SOME CEILINGS BELOW 2000 FEET SHOULD BE GOING TO
VFR BY LATE AFTERNOON. SOME LIGHT SHOWERS MOVING IN BY 00Z
CONTINUING THIS EVENING BUT THESE SHOULD BE ISOLATED AND NOT
AFFECT THE GENERALLY VFR CONDITIONS OVERNIGHT.
&&
.MARINE...
ISSUED AT 256 PM EDT SUN APR 1 2012
WINDS AND WAVES WILL BE RELATIVELY CALM THIS WEEK.
&&
.HYDROLOGY...
ISSUED AT 256 PM EDT SUN APR 1 2012
NO HYDRO ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM....JK
AVIATION...OSTUNO
HYDROLOGY...OSTUNO
MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
336 PM EDT SUN APR 1 2012
.SYNOPSIS...
ISSUED AT 1256 PM EDT SUN APR 1 2012
A FEW SHOWERS ARE POSSIBLE LATE THIS AFTERNOON AND EVENING. ANOTHER
CHANCE FOR SHOWERS AND THUNDERSTORMS WILL COME MONDAY NIGHT AND
TUESDAY. THEN HIGH PRESSURE WILL BRING FAIR WEATHER WITH FROSTY
OVERNIGHT LOWS FOR THE REST OF THE WEEK.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 1256 PM EDT SUN APR 1 2012
ADDED SLIGHT CHANCE POPS FOR LATE AFTERNOON INTO THIS EVENING.
OVERRUNNING SHOWERS CURRENTLY OVER NORTHERN WISCONSIN WILL BE
SINKING SOUTHEAST INTO LOWER MICHIGAN. HRRR RUC SEEMS TO HAVE A
HANDLE ON THESE AND THE TIMING WAS FOLLOWED IN THE GRIDS. ALSO
TWEAKED TEMPS DOWN A FEW DEGREES THIS AFTERNOON BASED ON CURRENT
OBS AND STUBBORN LOW LEVEL STRATUS THIS IS SLOW TO MIX OUT GIVEN
CURRENT STRONG INVERSION BELOW 700 MB.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 335 PM EDT SUN APR 1 2012
LOW PRESSURE IS EXPECTED TO BE SLIDING EAST OVER THE LOWER GREAT
LAKES ON TUESDAY. IT STILL LOOKS LIKE SOME POTENTIAL FOR STRONG
STORMS WILL HAIL...ESPECIALLY EARLY IN THE DAY...AND MAINLY ALONG
AND SOUTH OF I-96. SYSTEM LOOKS A BIT SLOWER NOW...SO HAVE POPS
GOING THROUGHOUT THE DAY.
VERY DRY AIR FOLLOWS THE SYSTEM BY TUESDAY EVENING WITH CLEARING
SKIES. COULD BE THE THREAT OF FROST BY WEDNESDAY MORNING...BUT
THIS SHOULD BE PATCHY OVER INLAND AREAS AS THE PRESSURE GRADIENT
SHOULD STILL CAUSE SOME MIXING THROUGH THE NIGHT. LOOKS LIKE THE
BEST CHANCE OF FROST WILL COME LATE WEDNESDAY NIGHT AND LATE
THURSDAY NIGHT AS THE SURFACE RIDGE AXIS WILL BE NEARBY GIVING US
LIGHTER WINDS AND SINKING TEMPS TO THE LOW TO MID 30S IN MANY
LOCATIONS.
NEXT CHANCE OF RAIN SHOULD NOT COME UNTIL SATURDAY NIGHT INTO
SUNDAY. STILL SOME UNCERTAINTY IN THIS GIVEN THE STRONG RIDGE TO
OUR EAST. BUT GENERAL GUIDANCE CONSCIENCE SHOWS A FRONT COMING
THROUGH ON SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED
AT 256 PM EDT SUN APR 1 2012
MVFR IN HAZE AND SOME CEILINGS BELOW
2000 FEET SHOULD BE GOING TO VFR BY LATE AFTERNOON. SOME LIGHT
SHOWERS MOVING IN BY 00Z CONTINUING THIS EVENING BUT THESE SHOULD
BE ISOLATED AND NOT AFFECT THE GENERALLY VFR CONDITIONS OVERNIGHT.
&&
.MARINE...
ISSUED AT 256 PM EDT SUN APR 1 2012
WINDS AND WAVES WILL BE RELATIVELY CALM THIS WEEK.
&&
.HYDROLOGY...
ISSUED AT 256 PM EDT SUN APR 1 2012
NO HYDRO ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM....JK
AVIATION...OSTUNO
HYDROLOGY...OSTUNO
MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
256 PM EDT SUN APR 1 2012
.SYNOPSIS...
ISSUED AT 1256 PM EDT SUN APR 1 2012
A FEW SHOWERS ARE POSSIBLE LATE THIS AFTERNOON AND EVENING. ANOTHER
CHANCE FOR SHOWERS AND THUNDERSTORMS WILL COME MONDAY NIGHT AND
TUESDAY. THEN HIGH PRESSURE WILL BRING FAIR WEATHER WITH FORSTY
OVERNIGHT LOWS FOR THE REST OF THE WEEK.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 1256 PM EDT SUN APR 1 2012
ADDED SLIGHT CHANCE POPS FOR LATE AFTERNOON INTO THIS EVENING.
OVERRUNNING SHOWERS CURRENTLY OVER NORTHERN WISCONSIN WILL BE
SINKING SOUTHEAST INTO LOWER MICHIGAN. HRRR RUC SEEMS TO HAVE A
HANDLE ON THESE AND THE TIMING WAS FOLLOWED IN THE GRIDS. ALSO
TWEAKED TEMPS DOWN A FEW DEGREES THIS AFTERNOON BASED ON CURRENT
OBS AND STUBBORN LOW LEVEL STRATUS THIS IS SLOW TO MIX OUT GIVEN
CURRENT STRONG INVERSION BELOW 700 MB.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 400 AM EDT SUN APR 1 2012
MONDAY NIGHT AND EARLY TUESDAY COULD BE ACTIVE WITH MCS ACTIVITY AS
H8 THETA-E RIDGE AND LOW LEVEL JET ARE PROGGED TO BE IMPACTING THE
REGION. ELEVATED INSTABILITY LOOKS PRETTY IMPRESSIVE WITH H8 LI/S
AROUND -6C. DEEP LAYER SHEAR IS IN EXCESS OF 35-40 KTS AND SUSPECT A
LARGE HAIL THREAT WILL EXIST WITH ANY TSTM CELLS/CLUSTERS TRACKING
SOUTHEAST THROUGH THE AREA. THE NAM/GFS SHOW THE SFC FRONT/TROUGH
EXITING THE REGION BY 18Z TUESDAY BUT THE EURO IS SLOWER AND
SUGGESTS A CONVECTIVE THREAT LINGERING ALL DAY TUESDAY.
WEDNESDAY THROUGH SATURDAY IS DOMINATED BY A LARGE/DRY AREA OF HIGH
PRESSURE. THIS FEATURE WILL BRING A THREAT OF FROST EACH NIGHT...
WITH SUNNY/PLEASANT CONDITIONS AND HIGHS IN THE 50S/60S EXPECTED FOR
THE DAYS. DIURNAL TEMP SWINGS SHOULD BE RATHER LARGE DUE TO THE DRY
AIR MASS AND MAINLY CLEAR SKIES. CONSIDERING THAT THE LOW LEVEL FLOW
SHOULD BE PREDOMINATELY NORTHEASTERLY... WOULD EXPECT THE WARMEST
HIGH TEMPERATURES TO BE IN THE WRN HALF OF THE CWFA DURING THE MID
TO LATE WEEK PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED
AT 256 PM EDT SUN APR 1 2012
MVFR IN HAZE AND SOME CEILINGS BELOW
2000 FEET SHOULD BE GOING TO VFR BY LATE AFTERNOON. SOME LIGHT
SHOWERS MOVING IN BY 00Z CONTINUING THIS EVENING BUT THESE SHOULD
BE ISOLATED AND NOT AFFECT THE GENERALLY VFR CONDITIONS OVERNIGHT.
&&
.MARINE...
ISSUED AT 256 PMEDT SUN APR 1 2012
WINDS AND WAVES WILL BE RELATIVELY CALM THIS WEEK.
&&
.HYDROLOGY...
ISSUED AT 256 PM EDT SUN APR 1 2012
NO HYDRO ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM....MEADE
AVIATION...OSTUNO
HYDROLOGY...OSTUNO
MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1257 PM EDT SUN APR 1 2012
.SYNOPSIS...
ISSUED AT 1256 PM EDT SUN APR 1 2012
A FEW SHOWERS ARE POSSIBLE LATE THIS AFTERNOON AND EVENING. ANOTHER
CHANCE FOR SHOWERS AND THUNDERSTORMS WILL COME MONDAY NIGHT AND
TUESDAY. THEN HIGH PRESSURE WILL BRING FAIR WEATHER WITH FORSTY
OVERNIGHT LOWS FOR THE REST OF THE WEEK.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 1256 PM EDT SUN APR 1 2012
ADDED SLIGHT CHANCE POPS FOR LATE AFTERNOON INTO THIS EVENING.
OVERRUNNING SHOWERS CURRENTLY OVER NORTHERN WISCONSIN WILL BE
SINKING SOUTHEAST INTO LOWER MICHIGAN. HRRR RUC SEEMS TO HAVE A
HANDLE ON THESE AND THE TIMING WAS FOLLOWED IN THE GRIDS. ALSO
TWEAKED TEMPS DOWN A FEW DEGREES THIS AFTERNOON BASED ON CURRENT
OBS AND STUBBORN LOW LEVEL STRATUS THIS IS SLOW TO MIX OUT GIVEN
CURRENT STRONG INVERSION BELOW 700 MB.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 400 AM EDT SUN APR 1 2012
MONDAY NIGHT AND EARLY TUESDAY COULD BE ACTIVE WITH MCS ACTIVITY AS
H8 THETA-E RIDGE AND LOW LEVEL JET ARE PROGGED TO BE IMPACTING THE
REGION. ELEVATED INSTABILITY LOOKS PRETTY IMPRESSIVE WITH H8 LI/S
AROUND -6C. DEEP LAYER SHEAR IS IN EXCESS OF 35-40 KTS AND SUSPECT A
LARGE HAIL THREAT WILL EXIST WITH ANY TSTM CELLS/CLUSTERS TRACKING
SOUTHEAST THROUGH THE AREA. THE NAM/GFS SHOW THE SFC FRONT/TROUGH
EXITING THE REGION BY 18Z TUESDAY BUT THE EURO IS SLOWER AND
SUGGESTS A CONVECTIVE THREAT LINGERING ALL DAY TUESDAY.
WEDNESDAY THROUGH SATURDAY IS DOMINATED BY A LARGE/DRY AREA OF HIGH
PRESSURE. THIS FEATURE WILL BRING A THREAT OF FROST EACH NIGHT...
WITH SUNNY/PLEASANT CONDITIONS AND HIGHS IN THE 50S/60S EXPECTED FOR
THE DAYS. DIURNAL TEMP SWINGS SHOULD BE RATHER LARGE DUE TO THE DRY
AIR MASS AND MAINLY CLEAR SKIES. CONSIDERING THAT THE LOW LEVEL FLOW
SHOULD BE PREDOMINATELY NORTHEASTERLY... WOULD EXPECT THE WARMEST
HIGH TEMPERATURES TO BE IN THE WRN HALF OF THE CWFA DURING THE MID
TO LATE WEEK PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 750 AM EDT SUN APR 1 2012
MVFR CONDITIONS DUE TO 3-5 MILE VSBYS IN LIGHT FOG WERE PRESENT
EARLY THIS MORNING. CIGS WERE MOSTLY 4-6K FEET WITH A FEW LIGHT
RAIN SHOWERS OR VIRGA/SPRINKLES DOTTING THE REGION.
DRIER AIR IS EXPECTED TO FLOW INTO THE REGION TODAY FROM NORTH TO
SOUTH AS A WEAK SFC FRONT PASSES THROUGH AND SETTLES SOUTH OF MI
THIS AFTERNOON. VSBYS ARE EXPECTED TO INCREASE ABOVE 6SM WITH THE
4-6K CLOUD DECK SCATTERING OUT AS THE FRONT COMES THROUGH AND
WINDS SHIFT NORTHERLY AROUND 8 KTS.
OPTED TO LEAVE THE MENTION OF TS/CB OUT OF THE I-94 CORRIDOR TAF
SITES SINCE THE ACTIVITY CURRENTLY OVER CHICAGO IS SLIDING SE AND
SHOULD NOT BE A FACTOR. ANY REDEVELOPMENT LATER TODAY SHOULD BE
JUST SOUTH OF THE MI BORDER NEAR THE SFC FRONT.
&&
.MARINE...
ISSUED AT 400 AM EDT SUN APR 1 2012
WINDS/WAVES WILL REMAIN UNDER SMALL CRAFT ADVISORY CRITERIA TODAY
INTO EARLY NEXT WEEK.
&&
.HYDROLOGY...
ISSUED AT 400 AM EDT SUN APR 1 2012
NO HYDRO CONCERNS DUE TO LITTLE IF ANY PCPN TODAY... LIGHT QPF
AMOUNTS MONDAY NIGHT/TUE FOLLOWED BY DRY WX MID TO LATE WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM....MEADE
AVIATION...MEADE
HYDROLOGY...LAURENS
MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS GLASGOW MT
1023 AM MDT SUN APR 1 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH TUESDAY...
UPDATED THE FORECAST TO LOWER THE CHANCE OF RAIN PER THE CURRENT
RADAR AND THE HRRR MODEL FOR THIS MORNING AND AFTERNOON. ALSO
LOWERED SKY COVER FOR THE AFTERNOON. REST OF THE SHORT TERM
FORECAST IS ON TRACK. RSMITH
PREVIOUS DISCUSSION...SPLITTING UPPER TROF MOVING ACROSS THE WEST
COAST...WILL BE FORMING A CUT OFF LOW OVER THE FOUR CORNERS WHILE
THE NORTHERN PORTION LIFTS ACROSS MONTANA AND INTO CENTRAL CANADA
THROUGH MONDAY. COLD FRONT ALONG THE WESTERN BORDER OF CWA WITH
SHOWERS AND A FEW THUNDERSTORMS STREAMING NORTHWARD ACROSS CENTRAL
MONTANA. WEAK SURFACE LOW DEVELOPING OVER SOUTHEAST MONTANA
EXPECTED TO PUSH TO THE NORTHEAST TODAY WHILE COLD FRONT MOVES
ACROSS EASTERN MONTANA. AREA OF SHOWERS AND THUNDERSTORMS ALSO
EXPECTED TO BE LIFTING NORTH SO MAINLY WILL BE AFFECTING THE FAR
WESTERN ZONES THIS MORNING.
STRONG COLD AIR ADVECTION BEHIND THE FRONT ALONG WITH TIGHTENING
PRESSURE GRADIENT WILL RESULT IN STRONG WEST WINDS BY AFTERNOON
PERSISTING INTO THE EVENING. AS SHOWERS MOVE NORTH AND WIND
INCREASE...RELATIVE HUMIDITY IS EXPECTED TO DROP IN THE
AFTERNOON... BRINGING ON CRITICAL FIRE WEATHER CONDITIONS.
COLD AIR ADVECTION CONTINUES THROUGH SUNDAY NIGHT WITH THE UPPER
TROF MOVING ACROSS THE STATE. THIS WILL KEEP WINDS FROM
DIMINISHING COMPLETELY.
BY MONDAY MORNING RIDGE BEGINS REBOUNDING OVER THE NORTHERN ROCKIES
BUT COLD AIR WILL LINGER OVER EASTERN MONTANA. WINDS WILL KICK UP
AGAIN IN THE AFTERNOON WITH GOOD MIXING EXPECTED.
UPPER RIDGE SPREADS OVER THE NORTHERN PLAINS ON TUESDAY WITH
WARMER AIR PUSHING INTO THE TREASURE STATE. HIGH PRESSURE MOVES
INTO THE CENTRAL PLAINS WITH WINDS GOING AROUND TO THE SOUTH AND
WEAK LEE TROF DEVELOPING IN CENTRAL MONTANA. EBERT
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
SYNOPTIC SET UP AS OF TUESDAY AFTERNOON... TO THE EAST A COLD AIR
POOL OVER THE HUDSON BAY IS DIVING INTO THE GREAT LAKES. A RIDGE
RIDES FROM DEATH VALLEY THROUGH CENTRAL MONTANA AND UP INTO
NORTHERN ALBERTA. A LONG WAVE TROUGH STRETCHES FROM YUKON TO THE
COAST OF BRITISH COLUMBIA DOWN TO OFF THE COAST OF NORTHERN
CALIFORNIA. FURTHER UP STREAM A SMALL RIDGE/TROUGH COMBO LIES JUST
SOUTH OF THE ALEUTIANS.
TUESDAY NIGHT THROUGH WEDNESDAY... RIDGE WILL BE IN FULL CONTROL
OVER THE AREA AND SHOULD PRECLUDE ANY SHOWERS WITH A SEMI STABLE
ATMOSPHERE. ANTICIPATE PARTLY CLOUDY TO CLEAR SKIES.
WEDNESDAY NIGHT THROUGH FRIDAY... OFF SHORE TROUGH WILL MOVE OVER
THE INTERMOUNTAIN WEST AND BEGIN IMPACTING THE CENTRAL MONTANA.
INITIALLY THUNDERSHOWERS WILL BE POSSIBLE DUE TO THE RIDGE
BREAKING DOWN AND LEE SIDE MOUNTAIN TROUGH SETTING UP THURSDAY
AFTERNOON. SOUTHWEST FLOW WILL ALSO BEING PUMPING MID LEVEL
MOISTURE AND MESOSCALE DISTURBANCES INTO THE REGION AS WELL.
THURSDAY NIGHT INTO FRIDAY A SURFACE LOW WILL BEGIN TO FORM AND
DRAG IN COLD AIR BEHIND THE SYSTEM. THE CONTRAST WILL PROVIDE LIFT
BUT SHOULD TURN IT INTO A STRATIFORM EVENT BY FRIDAY.
FRIDAY NIGHT ONWARD... MODELS ARE SWINGING AROUND A BIT AND
CONFIDENCE IS BELOW AVERAGE. WHERE AT FIRST WENT WITH AND EC/GEM
12Z BLEND THE NEW CONSENSUS IS GFS/EC 00Z BLEND. GOING PREDOMINATELY
PERSISTENCE AND USING SLIGHT BLENDS. SURFACE LOW PREVIOUSLY WAS
KICKED OUT TO THE EAST EARLY BUT NOW HOLDS ON OVER SOUTHERN CANADA
BEFORE EXITING SATURDAY AFTERNOON. REGION LOOKS TO PUSH FOR ZONAL
SO MODERATED TEMPERATURES OUT BY BLUNTING ANY COLD OR WARM PUSHES.
GAH
&&
.AVIATION...
VFR WITH ISOLATED SHOWERS THIS MORNING ACROSS THE TERMINALS.
THE WINDS WILL BE OUT OF THE EAST AT 5 TO 15 KNOTS DURING THE
EARLY MORNING. BY LATE MORNING TO MIDDAY A COLD FRONT WILL BACK
THE WINDS TO THE NORTHWEST AND INCREASE THEM TO AROUND 20 KTS
GUSTING TO 30 KTS.
KGDV TERMINAL AWOS EQUIPMENT IS HAVING PROBLEMS WITH VISIBILITY
AND OCCASIONAL CEILINGS IN METARS. AMENDMENTS WILL BE LIMITED TO
WINDS ONLY.
GAH
&&
.FIRE WEATHER...
A COLD FRONT WILL CROSS EASTERN MONTANA THIS MORNING WITH SLIGHTLY
COOLER BUT WINDIER CONDITIONS EXPECTED. RH WILL AGAIN DIP INTO
THE LOWER 20S DRIVING ANOTHER ROUND OF CRITICAL FIRE WEATHER
CONDITIONS ACROSS ALL OF NORTHEAST MONTANA.
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR
MTZ120-122-134>137.
LAKE WIND ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR FORT PECK LAKE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
656 PM EDT SUN APR 1 2012
.SYNOPSIS...
HIGH PRESSURE NORTH OF LAKE SUPERIOR WILL BUILD SOUTHEAST INTO THE
AREA TONIGHT THEN SHIFT OFF TO THE EAST TUESDAY. A COLD FRONT WILL
MOVE SOUTHEAST ACROSS THE REGION LATE TUESDAY THEN HIGH PRESSURE
WILL SPREAD SOUTHEAST INTO THE AREA BY WEDNESDAY NIGHT AND BECOMES
NEARLY STATIONARY INTO NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
SHOWERS AND A FEW EMBEDDED THUNDERSTORMS CONTINUE ALONG A CORRIDOR
THROUGH THE CENTRAL PORTION OF THE FORECAST AREA. THIS IS WELL
ALIGNED WITH THE GFS MODEL. THE GFS SHOWS A SMALL AREA OF POSITIVE
VORTICITY ADVECTION AND ASSOCIATED VORTICITY MAXIMUM MOVING
SOUTHEAST INTO THE AREA. A SWATH OF MOISTURE IS ALSO MOVING
SOUTHEAST INTO THE AREA AND HENCE THE PRECIPITATION. THE WHOLE
AREA WILL MOVE SOUTHWEST WITH TIME AS 500 MB LOW PRESSURE SYSTEM
RETROGRADES SOUTHWEST INTO THE AREA. THIS WILL HELP TO AMPLIFY THE
500 MB RIDGE WEST OF THE FORECAST AREA FORCING AXIS OF
PRECIPITATION TO SHIFT WEST AS WELL.
I WILL KEEP A MENTION OF THUNDER JUST IN CASE A RENEGADE CELL
DEVELOPS. I THINK THE THREAT FOR THUNDER WILL CONTINUE TO DIMINISH
AS THE SUN SETS THIS EVENING.
COLD AIR ADVECTION CONTINUES TO PUSH SOUTH AND HAS REACHED THE
EXTREME NORTHEAST PORTIONS OF THE FORECAST AREA BEHIND THE COLD
FRONT. CURRENT FORECAST TEMPERATURES LOOK REASONABLE AT THIS TIME.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
THE RIDGE OF HIGH PRESSURE OVER THE AREA SHOULD KEEP CONDITIONS DRY
INTO MON EVENING. A WEAKENING LOW ALONG A COLD FRONT WILL CROSS THE
AREA TUESDAY. MODELS HAVE BACKED DOWN ON OVERALL QPF FOR THIS EVENT
BUT STILL THINK MOST PLACES WILL SEE SOMETHING AT SOME POINT FROM
LATE MON NIGHT INTO TUE EVENING. AIRMASS CONTINUES TO LOOK UNSTABLE
ENOUGH FOR TSRA.
ANOTHER HIGH RIDGES SOUTH INTO THE CWA TUE NIGHT THROUGH WED
BRINGING DRIER AIR AND SHOULD END MOST OF THE SHRA THREAT FROM NORTH
TO SOUTH TUE EVENING. RIDGING REMAINS OVER AREA AND SHOULD KEEP DRY
WEATHER IN PLACE THROUGH THU NIGHT. HOWEVER...LATEST GFS NOW TRYING
TO BRING CUTOFF UPPER LOW CLOSER TO SW OH SO THIS WILL NEED TO BE
WATCHES NEXT FEW MODEL RUNS TO SEE IF THIS WILL TURN INTO A TYPICAL
SPRINGTIME UPPER LOW THAT FINDS A HOME IN OHIO.
WILL HAVE TO WATCH FOR FROST OR FREEZE THREAT FOR WED AND THU NIGHT
BUT RIGHT NOW LOOKS LIKE NORTH TO NE WINDS WILL STAY UP ENOUGH TO
KEEP FROST AWAY SO REAL CONCERN WILL BE WHERE TEMPS MAY TRY TO DROP
TO 32 OR LESS IN THE INLAND EAST THESE NIGHTS. SOME MOISTURE DROPS
SOUTH INTO THE SNOWBELT AREA FOR LATER WED NIGHT THROUGH THU NIGHT
AND COULD RESULT IN ENOUGH LAKE EFFECT CLOUDS TO KEEP TEMPS FROM
GETTING DOWN TO 32...THEREFORE A LOT OF UNCERTAINTY AS TO HOW LOW
TEMPS WILL GO WED AND THU NIGHT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
THE FORECASTS REMAIN CONSISTENT WITH A RIDGE ACROSS THE AREA FOR
FRIDAY AND SATURDAY. HOWEVER...A SYSTEM IS MOVING JUST TO THE SOUTH
OF THE REGION...THIS WILL HAVE TO BE WATCHED. AT THIS TIME IT SEEMS
LIKE THE RIDGE WILL BE STRONG ENOUGH TO KEEP IT SOUTH. FOR SUNDAY
AND SUNDAY NIGHT A FRONT WILL BE MOVING THROUGH. TIMING IS ON THE
EDGE. DID INCLUDE A CHANCE WEST SUNDAY AND MUCH OF THE AREA SUNDAY
NIGHT. TEMPERATURES WILL MODERATE AS THE RIDGE MOVES SLOWLY EAST.
WENT CLOSE TO HPC GUIDANCE FOR TEMPERATURE. DEPENDING ON THE
STRENGTH OF THE NORTHERLY FLOW IT WILL HELP KEEP TEMPERATURES COOLER
ALONG THE LAKESHORE AT TIMES.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
FRONTAL SYSTEMS AND LOW HEADED TOWARD THE FORECAST AREA FOR THE
AFTERNOON AND EVENING. THE FRONTS SEEM DIFFUSE SO THE WINDS WILL
PROBABLY JUST SHIFT ONCE THE LOW MOVES THROUGH. ATTM NOT THAT
EXCITED ABOUT A LOT OF THUNDERSTORM ACTIVITY AS MOST OF THE
UNSTABLE AIR WILL BE NEAR AND SOUTH OF THE SOUTHERN PORTION OF THE
FORECAST AREA. THE CLOUDS WILL BE IN AND OUT THROUGH MID AFTERNOON
BUT THE TREND WILL BE FOR CLOUDS MOVING BACK IN FROM THE
NORTHWEST.
THE WINDS WILL SHIFT FROM THE SOUTHWEST TO NORTHWEST AND THEN TO
NORTHEAST BY THIS EVENING. AS THIS HAPPENS AREAS OF MVFR CEILINGS
AND MAY BE EVEN SOME IFR THINGS WILL DEVELOP. AT THIS TIME IT
LOOKS LIKE IT SHOULD BE DRY TONIGHT. THE HRRR MODEL IS INDICATING
SOME SHOWERS...BUT ATTM THEY ARE NOT REACHING THE GROUND. THE
FORECAST IS FOR THE CLOUDS TO MOVE OUT OF THE REGION BY DAYBREAK
MONDAY. CONFIDENCE IN THIS IS FAIR.
.OUTLOOK...NON VFR POSSIBLE TUESDAY AND TUESDAY EVENING.
&&
.MARINE...
A LOW WILL BE MOVING ACROSS NORTHERN OHIO AND NORTHWEST PA THROUGH
THIS EVENING AND THIS WILL BRING THE WINDS AROUND FROM THE SOUTHWEST
TO NORTHEAST BETWEEN DARK AND MIDNIGHT. AS THIS HAPPENS THE WINDS
AND WAVES WILL PICK UP...THUS ISSUED A SMALL CRAFT ADVISORY FOR LAKE
ERIE STARTING AT 8 PM AND LASTING UNTIL NOON MONDAY.
AFTER THAT A RIDGE WILL BUILD IN BRIEFLY FOR MONDAY EVENING
DECREASING THE WINDS AND WAVES AND THEN IT WILL MOVE EAST.
FOR LATE TUESDAY THROUGH FRIDAY A THREAT FOR SMALL CRAFT ADVISORIES
AT TIMES WILL OCCUR. ANOTHER LOW WILL MOVE ACROSS OHIO LATE TUESDAY
AND THIS IN COMBINATION WITH A RIDGE BUILDING BACK IN THE WINDS AND
WAVES COULD BE CLOSE TO SMALL CRAFT ADVISORY CRITERIA. ON FRIDAY
ANOTHER LOW WILL MOVE THROUGH THE TENNESSEE VALLEY AND THIS IN
COMBINATION WITH THE RIDGE OVER LAKE ERIE WILL CAUSE A NORTHEAST
FLOW AND IT COULD BE STRONG ENOUGH TO CAUSE WAVES TO BE 3 TO 5 FEET.
ALL THIS WILL BE WATCHED CLOSELY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT MONDAY FOR LEZ142>149.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...LOMBARDY
SHORT TERM...ADAMS
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
325 PM EDT SUN APR 1 2012
.SYNOPSIS...
HIGH PRESSURE NORTH OF LAKE SUPERIOR WILL BUILD SOUTHEAST INTO THE
AREA TONIGHT THEN SHIFT OFF TO THE EAST TUESDAY. A COLD FRONT WILL
MOVE SOUTHEAST ACROSS THE REGION LATE TUESDAY THEN HIGH PRESSURE
WILL SPREAD SOUTHEAST INTO THE AREA BY WEDNESDAY NIGHT AND BECOMES
NEARLY STATIONARY INTO NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
DRIER AIR PUSHING SOUTH BEHIND THE COLD FRONT WILL PUSH THE THREAT
OF SHRA SOUTH OF THE CWA DURING THE EVENING OR CERTAINLY BY 1 TO 2
AM. SOME LAKE EFFECT CLOUDS MAY OCCUR BUT OVERALL LAKE EFFECT
CONDITIONS DO NOT APPEAR STRONG ENOUGH TO OFFSET STRONG SUBSIDENCE
OCCURRING AS HIGH PRESSURE RIDGES SOUTH INTO THE AREA. ANOTHER COOL
NIGHT WITH TEMPS IN THE EAST CLOSE TO FREEZING POINT BY DAYBREAK.
HOWEVER...THINK JUST ENOUGH WIND WILL CONTINUE THROUGH THE NIGHT TO
KEEP FROST FROM FORMING SO NO ADVISORY PLANNED.
&&
.SHORT TERM /MONDAY THROUGH THURSDAY NIGHT/...
THE RIDGE OF HIGH PRESSURE OVER THE AREA SHOULD KEEP CONDITIONS DRY
INTO MON EVENING. A WEAKENING LOW ALONG A COLD FRONT WILL CROSS THE
AREA TUESDAY. MODELS HAVE BACKED DOWN ON OVERALL QPF FOR THIS EVENT
BUT STILL THINK MOST PLACES WILL SEE SOMETHING AT SOME POINT FROM
LATE MON NIGHT INTO TUE EVENING. AIRMASS CONTINUES TO LOOK UNSTABLE
ENOUGH FOR TSRA.
ANOTHER HIGH RIDGES SOUTH INTO THE CWA TUE NIGHT THROUGH WED
BRINGING DRIER AIR AND SHOULD END MOST OF THE SHRA THREAT FROM NORTH
TO SOUTH TUE EVENING. RIDGING REMAINS OVER AREA AND SHOULD KEEP DRY
WEATHER IN PLACE THROUGH THU NIGHT. HOWEVER...LATEST GFS NOW TRYING
TO BRING CUTOFF UPPER LOW CLOSER TO SW OH SO THIS WILL NEED TO BE
WATCHES NEXT FEW MODEL RUNS TO SEE IF THIS WILL TURN INTO A TYPICAL
SPRINGTIME UPPER LOW THAT FINDS A HOME IN OHIO.
WILL HAVE TO WATCH FOR FROST OR FREEZE THREAT FOR WED AND THU NIGHT
BUT RIGHT NOW LOOKS LIKE NORTH TO NE WINDS WILL STAY UP ENOUGH TO
KEEP FROST AWAY SO REAL CONCERN WILL BE WHERE TEMPS MAY TRY TO DROP
TO 32 OR LESS IN THE INLAND EAST THESE NIGHTS. SOME MOISTURE DROPS
SOUTH INTO THE SNOWBELT AREA FOR LATER WED NIGHT THROUGH THU NIGHT
AND COULD RESULT IN ENOUGH LAKE EFFECT CLOUDS TO KEEP TEMPS FROM
GETTING DOWN TO 32...THEREFORE A LOT OF UNCERTAINTY AS TO HOW LOW
TEMPS WILL GO WED AND THU NIGHT.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
THE FORECASTS REMAIN CONSISTENT WITH A RIDGE ACROSS THE AREA FOR
FRIDAY AND SATURDAY. HOWEVER...A SYSTEM IS MOVING JUST TO THE SOUTH
OF THE REGION...THIS WILL HAVE TO BE WATCHED. AT THIS TIME IT SEEMS
LIKE THE RIDGE WILL BE STRONG ENOUGH TO KEEP IT SOUTH. FOR SUNDAY
AND SUNDAY NIGHT A FRONT WILL BE MOVING THROUGH. TIMING IS ON THE
EDGE. DID INCLUDE A CHANCE WEST SUNDAY AND MUCH OF THE AREA SUNDAY
NIGHT. TEMPERATURES WILL MODERATE AS THE RIDGE MOVES SLOWLY EAST.
WENT CLOSE TO HPC GUIDANCE FOR TEMPERATURE. DEPENDING ON THE
STRENGTH OF THE NORTHERLY FLOW IT WILL HELP KEEP TEMPERATURES COOLER
ALONG THE LAKESHORE AT TIMES.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
FRONTAL SYSTEMS AND LOW HEADED TOWARD THE FORECAST AREA FOR THE
AFTERNOON AND EVENING. THE FRONTS SEEM DIFFUSE SO THE WINDS WILL
PROBABLY JUST SHIFT ONCE THE LOW MOVES THROUGH. ATTM NOT THAT
EXCITED ABOUT A LOT OF THUNDERSTORM ACTIVITY AS MOST OF THE
UNSTABLE AIR WILL BE NEAR AND SOUTH OF THE SOUTHERN PORTION OF THE
FORECAST AREA. THE CLOUDS WILL BE IN AND OUT THROUGH MID AFTERNOON
BUT THE TREND WILL BE FOR CLOUDS MOVING BACK IN FROM THE
NORTHWEST.
THE WINDS WILL SHIFT FROM THE SOUTHWEST TO NORTHWEST AND THEN TO
NORTHEAST BY THIS EVENING. AS THIS HAPPENS AREAS OF MVFR CEILINGS
AND MAY BE EVEN SOME IFR THINGS WILL DEVELOP. AT THIS TIME IT
LOOKS LIKE IT SHOULD BE DRY TONIGHT. THE HRRR MODEL IS INDICATING
SOME SHOWERS...BUT ATTM THEY ARE NOT REACHING THE GROUND. THE
FORECAST IS FOR THE CLOUDS TO MOVE OUT OF THE REGION BY DAYBREAK
MONDAY. CONFIDENCE IN THIS IS FAIR.
.OUTLOOK...NON VFR POSSIBLE TUESDAY AND TUESDAY EVENING.
&&
.MARINE...
A LOW WILL BE MOVING ACROSS NORTHERN OHIO AND NORTHWEST PA THROUGH
THIS EVENING AND THIS WILL BRING THE WINDS AROUND FROM THE SOUTHWEST
TO NORTHEAST BETWEEN DARK AND MIDNIGHT. AS THIS HAPPENS THE WINDS
AND WAVES WILL PICK UP...THUS ISSUED A SMALL CRAFT ADVISORY FOR LAKE
ERIE STARTING AT 8 PM AND LASTING UNTIL NOON MONDAY.
AFTER THAT A RIDGE WILL BUILD IN BRIEFLY FOR MONDAY EVENING
DECREASING THE WINDS AND WAVES AND THEN IT WILL MOVE EAST.
FOR LATE TUESDAY THROUGH FRIDAY A THREAT FOR SMALL CRAFT ADVISORIES
AT TIMES WILL OCCUR. ANOTHER LOW WILL MOVE ACROSS OHIO LATE TUESDAY
AND THIS IN COMBINATION WITH A RIDGE BUILDING BACK IN THE WINDS AND
WAVES COULD BE CLOSE TO SMALL CRAFT ADVISORY CRITERIA. ON FRIDAY
ANOTHER LOW WILL MOVE THROUGH THE TENNESSEE VALLEY AND THIS IN
COMBINATION WITH THE RIDGE OVER LAKE ERIE WILL CAUSE A NORTHEAST
FLOW AND IT COULD BE STRONG ENOUGH TO CAUSE WAVES TO BE 3 TO 5 FEET.
ALL THIS WILL BE WATCHED CLOSELY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO NOON EDT
MONDAY FOR LEZ142>149.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...TK
SHORT TERM...ADAMS
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
150 PM EDT SUN APR 1 2012
.SYNOPSIS...
WEAK LOW PRESSURE WILL MOVE ACROSS THE GREAT LAKES TODAY. A WARM
FRONT WILL MOVE INTO THE AREA AHEAD OF THE LOW...FOLLOWED QUICKLY
BY A COLD FRONT. HIGH PRESSURE OVER ONTARIO WILL EXTEND ACROSS THE
EASTERN GREAT LAKES INTO THE OHIO VALLEY TONIGHT AND MONDAY. THE
HIGH WILL MOVE EAST TUESDAY AND ALLOW LOW PRESSURE TO DRIFT IN
FROM THE WEST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
GENERAL THINKING FROM PREVIOUS UPDATE (BELOW) REMAINS ON TRACK. ONLY
CHANGES ARE FOR CURRENT CONDITIONS AND BLENDING.
COLD FRONT SAGGING SOUTH ACROSS MUCH OF THE CWA THIS AFTERNOON INTO
EARLY EVENING STILL WELL NORTH OF THE CWA SO THINK MORE OF A SOUTH
TO SW FLOW SHOULD DOMINATE UNTIL AT LEAST 19Z TO 20Z THEN SHIFT TO
NW AND NORTH SHOULD START NEAR LERI AND PUSH SOUTH REST OF AFTERNOON
AND EVENING.
AS AIRMASS DESTABILIZES MORE WITH HEAT OF THE DAY EXPECT MORE
CONVECTION TO DEVELOP SO AS FRONT PUSHES THROUGH STILL SEE A GOOD
CHANCE FOR MOST AREAS. COULD BE SOME STRONG STORMS IN THE FAR SW BUT
THE SEVERE THREAT SHOULD STAY SW OF THE AREA WHERE MORE UNSTABLE AIR
EXISTS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
00Z THIS EVENING THE COLD FRONT SHOULD BE ACROSS SOUTHERN OHIO
WITH DRY AIR MOVING INTO THE AREA FROM THE NORTH. ENDED PRECIP
QUICKLY ALTHOUGH DID HOLD ONTO CHANCE POPS...HIGHEST SOUTH...THIS
EVENING TO COVER ANY LINGERING PRECIP. BY 03Z HOWEVER NAM SHOWS
DRY AIR IN PLACE AND POSITIVE CAPES WELL SOUTH OF THE AREA.
OVERNIGHT HIGH PRESSURE WILL CONTINUE TO BUILD IN. PAST TWO HIGHS
HAVE NOT MANAGED TO CLEAR OUT THE STRATUS BUT BUFKIT SHOWS DRIER
AIR WILL BE MOVING IN SO WILL GO AHEAD AND BUY INTO THE CLEARING.
MONDAY...HIGH PRESSURE WILL CONTINUE OVER THE AREA ALTHOUGH WINDS
WILL BE FROM THE NORTH/NORTHEAST. EXPECT LAKESHORE AREAS TO REMAIN
CHILLY VS INLAND. ALSO EXPECT A SIZABLE TEMP GRADIENT FROM
NORTHEAST TO SOUTHWEST WITH 850MB TEMPS 0 TO 2C OVER ERIE IN THE
AFTERNOON AND 8 TO 10C OVER FDY. TUESDAY THE HIGH WILL MOVE EAST
AND LOW PRESSURE WILL MOVE IN FROM THE WEST. 850MB TEMPS RISE TO
14C WITH ALL OF THE AREA IN THE WARM SECTOR AHEAD OF THE
APPROACHING COLD FRONT. EXPECTING A MILD AFTERNOON ALTHOUGH WITH
CAPES SHOWN ON THE NAM AROUND 2000 J/KG WILL LIKELY BE STORMY SO
WEST ABOVE GUIDANCE WITH LIKELY POPS FOR THUNDERSTORMS. MUCH DRIER
AIR MOVES IN DURING THE EVENING POST COLD FRONT AND BY
MORNING...IF SKIES CLEAR COULD SEE ANOTHER ROUND OF FROST.
WEDNESDAY AND WED NIGHT WILL BE DRY WITH NEAR NORMAL TEMPS.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
GFS AND ECMWF HAVE INCREASED IN SIMILARITY OVER THE PAST DAY TO
BRING STRONGER CONFIDENCE IN SHOWING HIGH PRESSURE OVER THE GREAT
LAKES WILL DOMINATE ACROSS THE FORECAST AREA THROUGH THE SECOND HALF
OF THE UPCOMING WEEK. THIS WILL ALLOW FOR DRY CONDITIONS AND
SEASONABLE TEMPERATURES. AS PREVIOUSLY MENTIONED...THE NORTH FLOW
OFF THE LAKE OR DEVELOPING LAKE BREEZES WITH A LIGHT GRADIENT...WILL
CAUSE FOR AT LEAST SEASONABLE TEMPERATURES ACROSS THE INTERIOR BUT
COOLER MAXES ALONG THE LAKESHORE.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
FRONTAL SYSTEMS AND LOW HEADED TOWARD THE FORECAST AREA FOR THE
AFTERNOON AND EVENING. THE FRONTS SEEM DIFFUSE SO THE WINDS WILL
PROBABLY JUST SHIFT ONCE THE LOW MOVES THROUGH. ATTM NOT THAT
EXCITED ABOUT A LOT OF THUNDERSTORM ACTIVITY AS MOST OF THE
UNSTABLE AIR WILL BE NEAR AND SOUTH OF THE SOUTHERN PORTION OF THE
FORECAST AREA. THE CLOUDS WILL BE IN AND OUT THROUGH MID AFTERNOON
BUT THE TREND WILL BE FOR CLOUDS MOVING BACK IN FROM THE
NORTHWEST.
THE WINDS WILL SHIFT FROM THE SOUTHWEST TO NORTHWEST AND THEN TO
NORTHEAST BY THIS EVENING. AS THIS HAPPENS AREAS OF MVFR CEILINGS
AND MAY BE EVEN SOME IFR THINGS WILL DEVELOP. AT THIS TIME IT
LOOKS LIKE IT SHOULD BE DRY TONIGHT. THE HRRR MODEL IS INDICATING
SOME SHOWERS...BUT ATTM THEY ARE NOT REACHING THE GROUND. THE
FORECAST IS FOR THE CLOUDS TO MOVE OUT OF THE REGION BY DAYBREAK
MONDAY. CONFIDENCE IN THIS IS FAIR.
.OUTLOOK...NON VFR POSSIBLE TUESDAY AND TUESDAY EVENING.
&&
.MARINE...
SFC HIGH PRESSURE OVER THE LAKE THIS MORNING WILL MOVE TO THE EAST
THIS MORNING AS A LOW PRESSURE AND COLD FRONT CROSS THE LAKE THIS
AFTERNOON AND EVENING. THIS WILL SHIFT WINDS FROM SOUTHERLY TODAY TO
NORTH AND NORTHEAST TONIGHT. WILL HAVE TO WATCH FOR SMALL CRAFT
ADVISORY POTENTIAL...BUT LOOKS LIKE THE GRADIENT WILL BE LIGHT
ENOUGH TO KEEP WINDS AROUND 15KT AND WAVES AROUND 3 FEET. THE NEXT
LOW PRESSURE EXPECTED TO MOVE ACROSS THE LAKE ON TUESDAY.
HOWEVER...AGAIN THIS SYSTEM LOOKS BE ON THE WEAKER SIDE ALSO. WHILE
WINDS WILL SHIFT FROM SOUTH TO NORTHERLY BETWEEN TUESDAY MORNING AND
TUESDAY NIGHT...CONDITIONS MAY ALSO REMAIN JUST BELOW SMALL CRAFT
CRITERIA. HIGH PRESSURE TO THE NORTH WILL DOMINATE OVER THE LAKE BY
WEDNESDAY AND PERSIST THROUGH THE WEEK. WITH HIGH PRESSURE RIDGING
SOUTH OVER THE LAKE DURING THE SECOND HALF OF THE WEEK...THE IS THE
CHANCE FOR A PERIOD OF SMALL CRAFT CONDITIONS WEDNESDAY OR THURSDAY
BEFORE IT BECOMES SETTLED OVER THE LAKE FOR THE END OF THE WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...ADAMS
SHORT TERM...TK
LONG TERM...ABE
AVIATION...ADAMS
MARINE...ABE
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
135 PM EDT SUN APR 1 2012
.SYNOPSIS...
A FRONTAL BOUNDARY WILL DROP SOUTH INTO THE OHIO VALLEY TODAY
OFFERING ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS. THIS FRONT
WILL PUSH INTO THE TENNESSEE VALLEY WITH SURFACE HIGH PRESSURE
PROVIDING A TEMPORARY DRY PERIOD ON MONDAY. THIS FRONT IS EXPECTED
TO RETURN BRINGING ADDITIONAL THUNDERSTORMS MONDAY NIGHT INTO
TUESDAY.
&&
.NEAR TERM /UNTIL 9 PM THIS EVENING/...
DECAYING MCS WILL BRING A CHANCE FOR SHOWERS MAINLY WEST OF I-75
THROUGH THE LATE MORNING. GRADUAL CLEARING BEHIND THIS
FEATURE...COMBINED WITH AMPLE WARM/MOISTURE ADVECTION FROM THE
SOUTHWEST ASSOCIATED WITH A WARM FRONT WILL LEAD TO TEMPERATURES
INTO THE LOW TO MID 70S ACROSS THE MAJORITY OF THE AREA BY LATE
THIS AFTERNOON.
NORTHWESTERLY FLOW ALOFT WILL INTENSIFY LATER TODAY AROUND THE
PERIPHERY A MID/UPPER LEVEL RIDGE BUILDING ACROSS THE PLAINS. AT
THE SAME TIME...A SHORTWAVE TROUGH WILL DROP ACROSS THE EASTERN
GREAT LAKES. THIS SHORTWAVE WILL DEVELOP A BACK DOOR COLD FRONT
WHICH WILL PUSH TOWARD THE OHIO VALLEY THIS EVENING. AHEAD OF THIS
FRONT...AN INCREASINGLY UNSTABLE BOUNDARY LAYER WILL COMBINE WITH
DEEP SHEAR TO DEVELOP THUNDERSTORMS ACROSS OUR AREA LATE THIS
AFTERNOON AND INTO THE EVENING. SOME OF THESE STORMS HAVE THE
POTENTIAL TO BECOME SEVERE. THE MAIN THREAT FROM THESE STORMS WILL
BE LARGE HAIL AND DAMAGING WINDS. HOWEVER...CANNOT RULE OUT AN
ISOLATED TORNADO. OVERALL...CONVECTION WILL INITIATE ACROSS THE
NORTH LATE THIS AFTERNOON...AND PUSH SSE ACROSS OUR SOUTH THIS
EVENING WITH THE MEAN FLOW.
HAVE FAVORED THE 12Z RUC FOR THIS UPDATE FOR TEMPS AND STORM
TIMING.
&&
.SHORT TERM /9 PM THIS EVENING THROUGH TUESDAY/...
A BACK DOOR TYPE COLD FRONT TO DROP SOUTH THRU THE OHIO VALLEY
AND STALL OUT OVER THE TN VLY OVERNIGHT. WL BUMP POPS UP TO LKLY
EARLY ACRS THE SE WHERE BEST FORCING WL EXIST AND THEN TAPER
PRECIP OFF FROM NORTH TO SOUTH. SOME OF THE STORMS MAY BE SEVERE
DURING INTO THE EARLY EVENING HOURS WITH THE MAIN THREATS BEING
WIND AND HAIL.
SFC HIGH PRESSURE WILL BRIEFLY BUILD INTO THE FA MONDAY PROVIDING
A TEMPORARY DRY PERIOD. HAVE TRENDED MONDAYS HIGHS A LTL COOLER ON
MONDAY...FROM THE MID 60S NE TO THE MID/UPR 70S SOUTHWEST. THE MID
LEVEL RIDGE WL BUILD E INTO THE REGION WITH UPPER LEVEL DISTURBANCE
PASSING THRU THE GREAT LAKES TUESDAY. ASSOCIATED SFC WAVE TO TRACK THRU
THE SRN GREAT LAKES. FRONT BOUNDARY TO PIVOT BACK NORTHEAST AS A
WARM FRONT LATE MON NIGHT/TUE AND THEN COLD FRONT TO DROP BACK DOWN
THRU THE OHIO VALLEY TUES NIGHT. NUMERICAL MODELS ARE NOT IN
AGREEMENT REGARDING THIS SYSTEM AND HOW ACTIVE THE INITIAL WARM FRONT
WL BE LATE MONDAY NIGHT/TUES. HAVE CHANCE/SLIGHT POPS RE-DEVELOPING
LATE WITH THE BEST PROBABILITY ACRS W CENTRAL OHIO. THEN ALLOW CHC
POPS TO LAY OUT E-W ON TUESDAY WITH THE APPROACH OF FRONT.
CONFIDENCE IS NOT HIGH REGARDING PRECIP CHANCES TUESDAY. ETA/GFS SOLNS
ARE FASTER BRINGING THE FRONT IN...WHICH THE ECMWF HOLDS IT BACK.
GOING WITH A SLIGHTLY SLOWER SOLN HAVE WARM TEMPS WITH TUESDAYS
FCST HIGHS RANGING FROM THE LOWER 70S FAR N TO AROUND 80 SOUTH.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HAVE FAVORED NON-GFS SOLUTION EARLY ON. THIS WOULD LEAD TO A SLOWER
PROGRESSION OF A FRONT AND ASSOCIATED PRECIPITATION. HOWEVER THERE
COULD BE SOME ELEVATED SHOWERS AND THUNDERSTORMS TUESDAY MORNING
WELL AHEAD OF THE FRONT. BUT MOST STORMS SHOULD HOLD OFF UNTIL LATE
TUESDAY AFTERNOON INTO TUESDAY NIGHT AS THE FRONT MOVES THROUGH.
THIS BOUNDARY WILL STALL IN THE TENNESSEE VALLEY AS HIGH PRESSURE
BUILDS ACROSS THE GREAT LAKES ON WEDNESDAY.
A CLOSED LOW WILL PASS SOUTH OF THE REGION ON THURSDAY AND THURSDAY
NIGHT WHICH MAY SPREAD SHOWERS AND THUNDERSTORMS BACK INTO THE
SOUTHERN ZONES. AFTER THIS PASSES HIGH PRESSURE WILL BE ABLE TO
BUILD SOUTH OVER THE REGION FOR THE END OF THE WEEK.
ABOVE NORMAL TEMPERATURES AT THE BEGINNING OF THE PERIOD WILL TREND
TOWARDS NORMAL BY LATER IN THE WEEK.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AFTER CLEARING DURING THE EARLY AFTERNOON...THUNDERSTORMS WILL
DEVELOP OUT AHEAD OF A BACK DOOR COLD FRONT LATE THIS AFTERNOON.
THESE STORMS WILL LIKELY AFFECT ALL TERMINALS DURING THE EVENING
HOURS. EXACT TIMING IS STILL A BIT UNCERTAIN FOR THE ARRIVAL OF
THESE STORMS...THEREFORE HAVE KEPT ANY TEMPOS OUT OF THE FORECAST
FOR NOT. THESE WILL LIKELY BE ADDED IN AMENDMENTS LATER ON...AFTER
THE STORMS ACTUALLY DEVELOP. REGARDLESS...MVFR/IFR VSBYS WILL BE
POSSIBLE IN HEAVIER STORMS.
WINDS WILL START OF SOUTHWESTERLY...THEN WILL VEER AS THE STORMS
PUSH ACROSS THE AREA...AND THE COLD FRONT MOVES THROUGH OVERNIGHT.
BY MONDAY MORNING...WINDS WILL BE NORTHEASTERLY AT 5 TO 10 KT.
THERE MAY BE A BRIEF PERIOD AFTER FRONTAL PASSAGE OVERNIGHT
TONIGHT WHERE CIGS DROP BELOW 3 KFT AS WELL. VFR CONDITIONS ARE
EXPECTED DURING THE DAY MONDAY.
OUTLOOK...SCATTERED THUNDERSTORMS POSSIBLE MONDAY NIGHT INTO
TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...AR
NEAR TERM...LATTO
SHORT TERM...AR
LONG TERM...
AVIATION...LATTO
AREA FORECAST DISCUSSION
NWS SPOKANE WA
225 PM PDT Sun Apr 1 2012
.SYNOPSIS...
The widespread wet weather over the past several days will come to
an end tonight leading to a dry start of the work week. A Pacific
cold front will move through the area Tuesday night and Wednesday
for more rain and mountain snow. The remainder of the week will
see cool temperatures with afternoon and evening showers. Next
weekend should be dry and warmer.
&&
.DISCUSSION...
Tonight: Afternoon instability convective showers will quickly die
off this evening along with the winds. The HRRR model (which has
done a great job with the convective line between Coulee Dam and
Spokane) is suggesting the formation of a convective line that
will move across the Spokane/Cd`A metro area around 7pm this
evening. Not enough confidence to hit the forecast hard but the
HRRR suggests it would be a graupel shower.
Winds are gusting to 35 mph but should be diminishing quickly so
will cancel the wind advisory with the afternoon forecast package.
Another minor wave has moved onto the Oregon coast today. Models
show the remnants of this wave tracking across northern Oregon and
then into the southern Panhandle. Will keep pops in the Panhandle
higher south of I-90. Any precip that does fall would all be in
the form of snow as snow levels come crashing down to the valleys
overnight. Light accumulations are possible in the valleys
south/east of Pullman. RJ
Monday through Tuesday night...High pressure will build over the
region on Monday for a warming and drying trend. This will be
followed by another deep low pressure system moving into the
region Tuesday and Tuesday night.
Monday and Monday night the ridge axis will be over the Inland
Northwest Monday morning ans slide east through the day. The 12z
models were showing a weak wave moving through my southeast zones
overnight and early Monday morning, with the NAM being a bit
stronger with this feature. The 18z NAM is still showing the wave,
but not quite as robust. However with southwest flow and lingering
low level moisture some showers were kept in the forecast. For
the rest of Monday southerly winds will result in up-sloping flow into
the northern mountains. Some light showers will be possible, but
not widespread and only light accumulations are expected at best.
Otherwise the southerly flow will increase temperatures across the
region into the upper 40s to upper 50s. Winds will remain gusty
through the day, but less then Sunday.
Tuesday and Tuesday night the flow will back to almost southerly
as the upper level low currently moving through the Gulf of Alaska
moves off the west coast. Southerly flow with warm air advection
will increase into the 50s and 60s, which are 5 to 8 degrees
above normal. Moisture will increase along the Cascades through
the day as the southerly flow taps into deep atmospheric river.
PW`S are on the order of .50 to .60 which are 120-130 percent of
normal. With the upper level flow parallel to the front it will
take time for precipitation to cross the Cascade through the day
on Tuesday with little eastward movement expected until later in
the afternoon/evening when the following cold front moves through
the region. Snow levels start out above 4000 feet across the
northwest zones and over 5500 feet across the southeast Tuesday,
then drop below 2500 feet behind the cold front Tuesday night.
By this time, however, the heaviest precipitation should have
moved east in the warm sector. As such precipitation will be mainly
as rain with high elevation snow turning to snow with and behind
the front. Accumulations will only be a few to several inches near
the Cascade crest and less for the northern and eastern mountains.
/Tobin
Wednesday through Sunday: A longwave trough will settle into
the region on Wednesday and remain stationary over the Interior
West through much of the work-week courtesy of a blocking high,
downstream across the central US/Canada. In comparison to Tuesday,
temperatures will be on the downward trend with widely scattered
showers possible for any location, just about every day, through
Saturday; especially late afternoon coinciding with afternoon
heating. Models are in pretty good agreement regarding the
placement/timing of the mid-level trough but continue to struggle
resolving each shortwave circulating within. We have maintained the
highest PoPs across the Northeast Mountains of WA and N ID due to
breezy southwest flow initially however as each of these shortwaves
pivoting within the mean trough, become better resolved, we can
anticipate that each shortwave will organize larger clusters of
showers and moderate changes to PoPs are highly anticipated. The
upper-level trough will eventually fill and become replaced by
shortwave ridging as a second pacific wave or "kicker" approaches
the coast over the weekend. The evolution of this wave still
carries a lot of uncertainty but loose agreement indicates the
potential for seasonal temperatures and dry conditions to return
to close out the weekend into the start of the new week. /sb
&&
.AVIATION...
18z TAFS: Afternoon showers will be most numerous in the Panhandle
and extreme eastern WA. Gusty winds will develop at most TAF sites
but should subside by late afternoon. Look for IFR cigs to develop
overnight at KGEG/KSFF/KCOE but these should lift by mid-morning
on Monday. RJ
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 31 52 39 62 39 45 / 20 10 0 10 60 60
Coeur d`Alene 31 49 36 61 38 44 / 30 10 0 10 70 70
Pullman 31 52 37 63 35 42 / 20 0 0 0 70 60
Lewiston 34 59 42 67 39 48 / 10 0 0 0 60 60
Colville 31 50 37 63 37 50 / 20 20 10 20 70 60
Sandpoint 30 47 35 60 38 44 / 40 10 10 10 70 70
Kellogg 31 45 33 59 36 41 / 40 20 10 10 80 90
Moses Lake 33 57 43 62 39 56 / 10 10 10 20 60 20
Wenatchee 36 56 43 56 35 54 / 10 10 10 40 40 20
Omak 31 54 40 58 35 53 / 10 10 10 60 50 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$