Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 03/14/12
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
759 PM MDT TUE MAR 13 2012
.UPDATE...
&&
.AVIATION...LATEST RUC SEEMS TO HAVE BEST HANDLE ON SFC WINDS
WHICH WILL GRADUALLY SHIFT FROM THE NW TO THE SW BY 05Z. BY 09Z
THEY WILL BECOME MORE SSW AND THEN REMAIN THAT WAY THROUGH 15Z.
&&
.PREV DISCUSSION... /ISSUED 305 PM MDT TUE MAR 13 2012/
SHORT TERM...VERY DRY SOUTHWESTERLY FLOW ALOFT WILL CONTINUE
THROUGH WEDNESDAY. DEW POINTS HAVE DROPPED TO SINGLE DIGITS AND
LOWER TODAY...AND EXPECT THAT TO HAPPEN AGAIN TOMORROW. TEMPERATURE
FORECASTS SHOW MAYBE ANOTHER DEGREE OR TWO OF WARMING OVER THE NEXT
24 HOURS. RELATIVE HUMIDITIES WILL ONCE AGAIN DROP TO ABOUT 10
PERCENT. ONCE AGAIN...PRESSURE GRADIENTS WILL REMAIN WEAK WHICH
WILL HELP KEEP WINDS DOWN. 700 MB WINDS LOOK TO BE ABOUT 5 KNOTS
WEAKER TOMORROW THAN THEY ARE TODAY...SO AFTERNOON GUSTS TOMORROW
AFTERNOON SHOULD REMAIN BELOW 20 KNOTS. WITHOUT THE WIND...THE NEED
FOR ANY FIRE WEATHER HIGHLIGHTS IS LOW. SUNNY SKIES AND
TEMPERATURES CLOSE TO RECORD HIGHS WILL CONTINUE TO BE THE MAIN
STORY.
LONG TERM...LITTLE CHANGE EXPECTED WEDNESDAY NIGHT THROUGH FRIDAY
NIGHT. MODELS HAVE PRETTY WEAK WEST-SOUTHWESTERLY FLOW ALOFT FOR
THE CWA THROUGH THAT PERIOD. THE QG VERTICAL VELOCITY FIELDS SHOW
BENIGN SYNOPTIC SCALE ENERGY THROUGH FRIDAY NIGHT. THE BOUNDARY
LAYER FLOW LOOKS LIKE A MIX BETWEEN NORMAL DIURNAL TRENDS COUPLED
WITH SOME DOWNSLOPING. WIND SPEED PROGGS ARE NOT SIGNIFICANT. FOR
MOISTURE...THERE IS JUST A BIT PROGGED IN THE MID AND UPPER LEVELS
FROM TIME TO TIME WEDNESDAY NIGHT THROUGH FRIDAY NIGHT. THERE IS NO
MEASURABLE PRECIPITATION ON THE QPF FIELDS WEDNESDAY NIGHT THROUGH
FRIDAY NIGHT. NO POPS. FOR TEMPERATURES...THURSDAY`S HIGHS ARE A
TAD COOLER THAN WEDNESDAY`S. THEN FRIDAY`S ARE UP A BIT FROM
THURSDAY`S. FOR THE LATER DAYS...SATURDAY THROUGH TUESDAY...MODELS
HAVE SOUTHWESTERLY FLOW ALOFT ON SATURDAY...THEN IT INCREASES AND IS
SOUTH-SOUTHWESTERLY ON SUNDAY. BY MONDAY INTO TUESDAY...THE FLOW
ALOFT IS DUE SOUTHERLY WITH A 100 PLUS KNOW JET MAXIMUM OVER
COLORADO. AT 00Z LATE TUESDAY AFTERNOON...THE GFS HAS THE CENTER OF
AN UPPER LOW OVER NEW MEXICO...THE ECMWF HAS IT OVER THE SOUTHERN
TIP OF NEVADA. FOR MOISTURE...SATURDAY AND SUNDAY ARE PRETTY DRY.
ON MONDAY...MOISTURE STARTS TO INCREASE. THE MOISTURE IS BEST ON
TUESDAY...BUT STILL NOT GREAT. THE GFS HAS MORE ON TUESDAY THAN THE
ECMWF. POPS SHOULD BE IN THE 20-30%S RANGE FOR THE MOUNTAINS SUNDAY
THROUGH TUESDAY...WITH A "SLIGHT CHANCE" OF SHOWERS FOR PLAINS
TUESDAY. TEMPERATURES STAY FAIRLY WARM THROUGH MONDAY.
AVIATION...NO AVIATION IMPACTS FOR THE NEXT 24 HOURS. WINDS WILL
CONTINUE TO HAVE A SOUTHERLY COMPONENT OVERNIGHT AND AGAIN
WEDNESDAY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DANKERS
LONG TERM....RJK
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1246 PM CDT MON MAR 12 2012
.DISCUSSION...
ISSUED 1020 AM CDT MON MAR 12 2012
UPDATED THE FORECAST TODAY TO INCREASE CHANCES OF SHOWERS AND
ADDED ISOLATED THUNDERSTORMS LATE THIS MORNING AROUND GALESBURG
IN KNOX COUNTY. ALSO INCREASED WIND SPEEDS TODAY AS SOUTH WINDS
15 TO 25 MPH AND GUSTS 30 TO 40 MPH TURN SW DURING THE AFTERNOON.
ANOTHER MINOR ADJUSTMENT TO THE FORECAST WAS TO EXPAND THE SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON A BIT FURTHER
SOUTH (TO JUST SOUTH OF I-74).
FAIRLY STRONG 543 DM 500 MB LOW WAS DEEPENING OVER THE EASTERN
MN/IA BORDER AS IT WAS TRACKING NE. AS THE SURFACE A STRONG 990 MB
LOW PRESSURE WAS ALONG THE NORTHERN ALBERTA/SASKATCHEWAN PROVINCE
LINE WITH A FRONTAL BOUNDARY EXTENDING SOUTHWARD ACROSS THE
CENTRAL PLAINS OVER CENTRAL NE/KS INTO NW TX. 1032 MB HIGH
PRESSURE WAS OFF THE EAST COAST. BREEZY SOUTH WINDS OF 15 TO 25
MPH AND GUSTS TO AROUND 30 MPH OVER CENTRAL IL BETWEEN THESE
WEATHER FEATURES. THIS HAD BROUGHT IN MILD AND MOIST AIR INTO IL
WITH DEWPOINTS IN THE MID TO UPPER 50S AND TEMPS AT 10 AM IN THE
LOWER 60S. RADAR MOSAIC SHOWS A STRENGTHENING BAND OF SHOWERS WITH
A FEW EMBEDDED THUNDERSTORMS IN NW IL NORTH OF GALESBURG INTO EAST
CENTRAL IA AND SOUTHERN WI AND MOVING NE.
12Z MODELS TAKE UPPER LEVEL LOW PRESSURE NE INTO WESTERN LAKE
SUPERIOR BY SUNSET WHILE THE FRONTAL BOUNDARY IN THE CENTRAL
PLAINS WEAKENS AS IT DRIFTS EASTWARD TOWARD THE MS VALLEY. INSTABILITY
INCREASES ACROSS EASTERN IL THIS AFTERNOON WITH CAPES INCREASING
TO 1000-1500 J/KG BY 21Z/4 PM EAST OF I-55. UPPER LEVEL DYNAMICS
PASS ACROSS NORTHERN IL SO BEST CHANCES OF SHOWERS AND
THUNDERSTORMS WILL BE OVER NE IL AROUND CHICAGO METRO. SPC HAS A
SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON FROM PONTIAC NE
WITH GENERAL RISK OF THUNDERSTORM SW TO ALONG I-74 CORRIDOR.
ISOLATED SHOWERS AND THUNDERSTORMS EXPECTED THIS AFTERNOON ALONG
AND NE OF I-74 AND A FEW STORMS COULD BECOME STRONG WITH HAIL AND
GUSTY WINDS. SPC HAS 2% RISK OF TORNADOES AND 5% RISK OF LARGE
HAIL AND DAMAGING WIND GUSTS NE OF BLOOMINGTON AND DANVILLE THIS
AFTERNOON. TEMPS TO CLIMB ANOTHER 10 DEGREES INTO THE LOWER TO
MIDDLE 70S AS MOSTLY CLOUDY SKIES BECOME PARTLY TO MOSTLY SUNNY
THIS AFTERNOON.
HUETTL
&&
.AVIATION...
ISSUED 1245 PM CDT MON MAR 12 2012
MVFR BROKEN CEILINGS OF 2.5-3K FT ALONG I-74 TAF SITES OF PIA...
BMI AND CMI. ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE ALONG
I-74 THIS AFTERNOON AND SINCE QUITE ISOLATED IN NATURE...JUST
CARRIED A CB WITH BETTER CHANCES OF THUNDERSTORMS IN NE IL. THIS
DUE TO 544 DM 500 MB LOW NEAR THE MN/WI BORDER THAT MOVES INTO
WESTERN LAKE SUPERIOR BY 00Z/7 PM EALRY THIS EVENING. STRONG SSW
WINDS OF 15 TO 25 KTS WITH GUSTS OF 25 TO 35 KTS TO DIMINISH UNDER
10 KTS AND TURN WSW AFTER SUNSET. HAVE MVFR VISIBILITIES WITH
LIGHT FOG OF 4-5 MILES POSSIBLE FROM 09Z-14Z (4-9 AM) TUE
MORNING. FAIR CONDITIONS EXPECTED TUE WITH LIGHT WINDS AS WEAK
HIGH PRESSURE RIDGE SETTLES OVER IL BY 18Z/1 PM TUE.
HUETTL
&&
.PREV DISCUSSION...
ISSUED 227 AM CDT MON MAR 12 2012
UPPER LOW CLEARLY EVIDENT IN INFRARED AND WATER VAPOR SATELLITE
IMAGERY...CENTERED OVER EASTERN NEBRASKA. DRY SLOT HAS PUSHED
ACROSS MUCH OF THE CWA...REDUCING THE RAIN TO SCATTERED SHOWERS.
THE EXTENT OF THE LINGERING RAIN IS THE INITIAL FORECAST CONCERN...
BUT THE PRIMARY FOCUS IS THE EXTENDED PERIOD OF ABNORMALLY WARM
WEATHER FOR MID MARCH.
SHORT TERM...TODAY THROUGH WEDNESDAY...
00Z MODELS ARE IN GOOD AGREEMENT WITH TRACKING THE LOW INTO WEST
CENTRAL WISCONSIN BY LATE MORNING...THEN TO THE UPPER PENINSULA OF
MICHIGAN BY EARLY EVENING. LINGERING SHOWERS ACROSS THE EASTERN
CWA SHOULD BE OUT OF THE AREA BY MID TO LATE MORNING. NORTHERN CWA
IS A BIT MORE QUESTIONABLE...AS NAM AND HRRR BOTH SHOWING SOME
INSTABILITY SHOWERS REFORMING IN THE COLDER AIR ALOFT. BOTH MODELS
SHOWING THE BEST RAIN CHANCES IN OUR NORTHERN CWA IN THE MORNING...
BUT WILL LINGER SOME SLIGHT CHANCES THERE INTO THE AFTERNOON AS
WELL.
UPPER RIDGING ACROSS THE CENTRAL U.S. BEGINS IN EARNEST LATER
TONIGHT AND PERSISTS MUCH OF THE WEEK. START OF THE WARMING TREND
BEGINS TODAY AND BY WEDNESDAY...WE WILL LIKELY BE SEEING 80 DEGREE
TEMPERATURES IN SEVERAL LOCATIONS. MOST RECORD HIGHS ON WEDNESDAY
ARE IN THE 74-78 RANGE...WITH SOME LOWER 80S ACROSS THE
SOUTHEAST...SO WILL LIKELY SEE SEVERAL RECORDS FALL. MODELS ARE
SOMEWHAT INCONSISTENT WITH SHOWER/THUNDERSTORM POTENTIAL ON
WEDNESDAY WITH THE RIDGE IN PLACE...BUT RAIN CHANCES INCREASE
WEDNESDAY NIGHT AS A WEAKENING BOUNDARY DROPS INTO THE AREA.
LONG TERM...THURSDAY THROUGH SUNDAY...
850 MB TEMPERATURES REMAIN CLOSE TO +12C THROUGH THE PERIOD...AS
THE UPPER RIDGE GRADUALLY SHIFTS TO THE EAST COAST. HOWEVER...CLOUD
COVER WILL BE MORE OF A FACTOR...AS WEAK WAVES IN THE UPPER FLOW
BRING PERIODIC CHANCES OF SHOWERS AND STORMS. HAVE KEPT HIGHS WELL
INTO THE 70S THROUGH THE PERIOD...BUT HAVE NOT GONE AS AGGRESSIVE
AS WEDNESDAY DUE TO THIS ISSUE.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1023 AM CDT MON MAR 12 2012
.DISCUSSION...
ISSUED 1020 AM CDT MON MAR 12 2012
UPDATED THE FORECAST TODAY TO INCREASE CHANCES OF SHOWERS AND
ADDED ISOLATED THUNDERSTORMS LATE THIS MORNING AROUND GALESBURG
IN KNOX COUNTY. ALSO INCREASED WIND SPEEDS A BIT TODAY AS SOUTH
WINDS 15 TO 25 MPH AND GUSTS AROUND 35 MPH TURN SW DURING THE
AFTERNOON. ANOTHER MINOR ADJUSTMENT TO THE FORECAST WAS TO EXPAND
THE SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON A
BIT FURTHER SOUTH (TO JUST SOUTH OF I-74).
FAIRLY STRONG 543 DM 500 MB LOW WAS DEEPENING OVER THE EASTERN
MN/IA BORDER AS IT WAS TRACKING NE. AS THE SURFACE A STRONG 990 MB
LOW PRESSURE WAS ALONG THE NORTHERN ALBERTA/SASKATCHEWAN PROVINCE
LINE WITH A FRONTAL BOUNDARY EXTENDING SOUTHWARD ACROSS THE
CENTRAL PLAINS OVER CENTRAL NE/KS INTO NW TX. 1032 MB HIGH
PRESSURE WAS OFF THE EAST COAST. BREEZY SOUTH WINDS OF 15 TO 25
MPH AND GUSTS TO AROUND 30 MPH OVER CENTRAL IL BETWEEN THESE
WEATHER FEATURES. THIS HAD BROUGHT IN MILD AND MOIST AIR INTO IL
WITH DEWPOINTS IN THE MID TO UPPER 50S AND TEMPS AT 10 AM IN THE
LOWER 60S. RADAR MOSAIC SHOWS A STRENGTHENING BAND OF SHOWERS WITH
A FEW EMBEDDED THUNDERSTORMS IN NW IL NORTH OF GALESBURG INTO EAST
CENTRAL IA AND SOUTHERN WI AND MOVING NE.
12Z MODELS TAKE UPPER LEVEL LOW PRESSURE NE INTO WESTERN LAKE
SUPERIOR BY SUNSET WHILE THE FRONTAL BOUNDARY IN THE CENTRAL
PLAINS WEAKENS AS IT DRIFTS EASTWARD TOWARD THE MS VALLEY. INSTABILITY
INCREASES ACROSS EASTERN IL THIS AFTERNOON WITH CAPES INCREASING
TO 1000-1500 J/KG BY 21Z/4 PM EAST OF I-55. UPPER LEVEL DYNAMICS
PASS ACROSS NORTHERN IL SO BEST CHANCES OF SHOWERS AND
THUNDERSTORMS WILL BE OVER NE IL AROUND CHICAGO METRO. SPC HAS A
SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON FROM PONTIAC NE
WITH GENERAL RISK OF THUNDERSTORM SW TO ALONG I-74 CORRIDOR.
ISOLATED SHOWERS AND THUNDERSTORMS EXPECTED THIS AFTERNOON ALONG
AND NE OF I-74 AND A FEW STORMS COULD BECOME STRONG WITH HAIL AND
GUSTY WINDS. SPC HAS 2% RISK OF TORNADOES AND 5% RISK OF LARGE
HAIL AND DAMAGING WIND GUSTS NE OF BLOOMINGTON AND DANVILLE THIS
AFTERNOON. TEMPS TO CLIMB ANOTHER 10 DEGREES INTO THE LOWER TO
MIDDLE 70S AS MOSTLY CLOUDY SKIES BECOME PARTLY TO MOSTLY SUNNY
THIS AFTERNOON.
HUETTL
&&
.AVIATION...
ISSUED 530 AM CDT MON MAR 12 2012
UPPER LOW SHIFTING NE THRU WEST CENTRAL IA EARLY THIS MORNING HAS
SPREAD MVFR AND ISOLD IFR CIGS ACRS THE FORECAST AREA ALONG WITH
ISOLD SHOWERS. LOOKS LIKE AREAS ALONG THE ILLINOIS RIVER VALLEY
AND WEST STAND THE BEST CHANCE FOR SEEING ADDL RAINFALL THIS MRNG
BUT COVERAGE HAS DIMINISHED FROM EARLIER SO WILL JUST ADD VCSH
RATHER THAN TEMPO A GROUP FOR ANY PROLONGED PERIOD OF RAINFALL.
SHOULD SEE SOME DRY AIR WORK ITS WAY INTO THE SOUTHERN PORTIONS
OF THE TAF AREA THIS MRNG WITH MVFR CIGS COMMON ACRS THE NORTH
INTO THIS AFTERNOON. WEAK FRONTAL BOUNDARY WILL THEN SHIFT SE
ACRS THE AREA AFTR 21Z WITH THE POTENTIAL FOR ISOLD TSRA ALONG
IT...BUT COVERAGE WILL BE TOO LIMITED TO MENTION IN TAFS OTHER
THAN A CB GROUP IN PIA...BMI AND CMI IN THE 22Z-02Z TIME FRAME.
FRONTAL BOUNDARY SHOULD THEN SHIFT EAST OF THE TAF SITES AFTR 04Z
WITH VFR CONDITIONS EXPECTED UNTIL LATE TONIGHT WHEN SOME GROUND
FOG MAY DEVELOP IN THE 09Z-12Z TIME FRAME. WILL ADD 4-5SM IN FOG
LATE IN THE FORECAST PERIOD TO COVER THIS POTENTIAL. SFC WINDS
WILL BE GUSTY TODAY OUT OF THE SOUTH TO SOUTHWEST WITH PREVAILING
SPEEDS OF 12 TO 17 KTS...AND GUSTS IN THE 25 TO 30 KT RANGE LATE
THIS MRNG INTO THIS AFTN. WINDS SHOULD VEER MORE INTO A WESTERLY
DIRECTION LATE THIS AFTN AND EVENING AND THEN BEGIN TO DIMINISH
AFTR DARK.
SMITH
&&
.PREV DISCUSSION...
ISSUED 227 AM CDT MON MAR 12 2012
UPPER LOW CLEARLY EVIDENT IN INFRARED AND WATER VAPOR SATELLITE
IMAGERY...CENTERED OVER EASTERN NEBRASKA. DRY SLOT HAS PUSHED
ACROSS MUCH OF THE CWA...REDUCING THE RAIN TO SCATTERED SHOWERS.
THE EXTENT OF THE LINGERING RAIN IS THE INITIAL FORECAST CONCERN...
BUT THE PRIMARY FOCUS IS THE EXTENDED PERIOD OF ABNORMALLY WARM
WEATHER FOR MID MARCH.
SHORT TERM...TODAY THROUGH WEDNESDAY...
00Z MODELS ARE IN GOOD AGREEMENT WITH TRACKING THE LOW INTO WEST
CENTRAL WISCONSIN BY LATE MORNING...THEN TO THE UPPER PENINSULA OF
MICHIGAN BY EARLY EVENING. LINGERING SHOWERS ACROSS THE EASTERN
CWA SHOULD BE OUT OF THE AREA BY MID TO LATE MORNING. NORTHERN CWA
IS A BIT MORE QUESTIONABLE...AS NAM AND HRRR BOTH SHOWING SOME
INSTABILITY SHOWERS REFORMING IN THE COLDER AIR ALOFT. BOTH MODELS
SHOWING THE BEST RAIN CHANCES IN OUR NORTHERN CWA IN THE MORNING...
BUT WILL LINGER SOME SLIGHT CHANCES THERE INTO THE AFTERNOON AS
WELL.
UPPER RIDGING ACROSS THE CENTRAL U.S. BEGINS IN EARNEST LATER
TONIGHT AND PERSISTS MUCH OF THE WEEK. START OF THE WARMING TREND
BEGINS TODAY AND BY WEDNESDAY...WE WILL LIKELY BE SEEING 80 DEGREE
TEMPERATURES IN SEVERAL LOCATIONS. MOST RECORD HIGHS ON WEDNESDAY
ARE IN THE 74-78 RANGE...WITH SOME LOWER 80S ACROSS THE
SOUTHEAST...SO WILL LIKELY SEE SEVERAL RECORDS FALL. MODELS ARE
SOMEWHAT INCONSISTENT WITH SHOWER/THUNDERSTORM POTENTIAL ON
WEDNESDAY WITH THE RIDGE IN PLACE...BUT RAIN CHANCES INCREASE
WEDNESDAY NIGHT AS A WEAKENING BOUNDARY DROPS INTO THE AREA.
LONG TERM...THURSDAY THROUGH SUNDAY...
850 MB TEMPERATURES REMAIN CLOSE TO +12C THROUGH THE PERIOD...AS
THE UPPER RIDGE GRADUALLY SHIFTS TO THE EAST COAST. HOWEVER...CLOUD
COVER WILL BE MORE OF A FACTOR...AS WEAK WAVES IN THE UPPER FLOW
BRING PERIODIC CHANCES OF SHOWERS AND STORMS. HAVE KEPT HIGHS WELL
INTO THE 70S THROUGH THE PERIOD...BUT HAVE NOT GONE AS AGGRESSIVE
AS WEDNESDAY DUE TO THIS ISSUE.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
536 AM CDT MON MAR 12 2012
.DISCUSSION...
ISSUED 227 AM CDT MON MAR 12 2012
UPPER LOW CLEARLY EVIDENT IN INFRARED AND WATER VAPOR SATELLITE
IMAGERY...CENTERED OVER EASTERN NEBRASKA. DRY SLOT HAS PUSHED
ACROSS MUCH OF THE CWA...REDUCING THE RAIN TO SCATTERED SHOWERS.
THE EXTENT OF THE LINGERING RAIN IS THE INITIAL FORECAST CONCERN...
BUT THE PRIMARY FOCUS IS THE EXTENDED PERIOD OF ABNORMALLY WARM
WEATHER FOR MID MARCH.
SHORT TERM...TODAY THROUGH WEDNESDAY...
00Z MODELS ARE IN GOOD AGREEMENT WITH TRACKING THE LOW INTO WEST
CENTRAL WISCONSIN BY LATE MORNING...THEN TO THE UPPER PENINSULA OF
MICHIGAN BY EARLY EVENING. LINGERING SHOWERS ACROSS THE EASTERN
CWA SHOULD BE OUT OF THE AREA BY MID TO LATE MORNING. NORTHERN CWA
IS A BIT MORE QUESTIONABLE...AS NAM AND HRRR BOTH SHOWING SOME
INSTABILITY SHOWERS REFORMING IN THE COLDER AIR ALOFT. BOTH MODELS
SHOWING THE BEST RAIN CHANCES IN OUR NORTHERN CWA IN THE MORNING...
BUT WILL LINGER SOME SLIGHT CHANCES THERE INTO THE AFTERNOON AS
WELL.
UPPER RIDGING ACROSS THE CENTRAL U.S. BEGINS IN EARNEST LATER
TONIGHT AND PERSISTS MUCH OF THE WEEK. START OF THE WARMING TREND
BEGINS TODAY AND BY WEDNESDAY...WE WILL LIKELY BE SEEING 80 DEGREE
TEMPERATURES IN SEVERAL LOCATIONS. MOST RECORD HIGHS ON WEDNESDAY
ARE IN THE 74-78 RANGE...WITH SOME LOWER 80S ACROSS THE
SOUTHEAST...SO WILL LIKELY SEE SEVERAL RECORDS FALL. MODELS ARE
SOMEWHAT INCONSISTENT WITH SHOWER/THUNDERSTORM POTENTIAL ON
WEDNESDAY WITH THE RIDGE IN PLACE...BUT RAIN CHANCES INCREASE
WEDNESDAY NIGHT AS A WEAKENING BOUNDARY DROPS INTO THE AREA.
LONG TERM...THURSDAY THROUGH SUNDAY...
850 MB TEMPERATURES REMAIN CLOSE TO +12C THROUGH THE PERIOD...AS
THE UPPER RIDGE GRADUALLY SHIFTS TO THE EAST COAST. HOWEVER...CLOUD
COVER WILL BE MORE OF A FACTOR...AS WEAK WAVES IN THE UPPER FLOW
BRING PERIODIC CHANCES OF SHOWERS AND STORMS. HAVE KEPT HIGHS WELL
INTO THE 70S THROUGH THE PERIOD...BUT HAVE NOT GONE AS AGGRESSIVE
AS WEDNESDAY DUE TO THIS ISSUE.
GEELHART
&&
.AVIATION...
ISSUED 530 AM CDT MON MAR 12 2012
UPPER LOW SHIFTING NE THRU WEST CENTRAL IA EARLY THIS MORNING HAS
SPREAD MVFR AND ISOLD IFR CIGS ACRS THE FORECAST AREA ALONG WITH
ISOLD SHOWERS. LOOKS LIKE AREAS ALONG THE ILLINOIS RIVER VALLEY
AND WEST STAND THE BEST CHANCE FOR SEEING ADDL RAINFALL THIS MRNG
BUT COVERAGE HAS DIMINISHED FROM EARLIER SO WILL JUST ADD VCSH
RATHER THAN TEMPO A GROUP FOR ANY PROLONGED PERIOD OF RAINFALL.
SHOULD SEE SOME DRY AIR WORK ITS WAY INTO THE SOUTHERN PORTIONS
OF THE TAF AREA THIS MRNG WITH MVFR CIGS COMMON ACRS THE NORTH
INTO THIS AFTERNOON. WEAK FRONTAL BOUNDARY WILL THEN SHIFT SE
ACRS THE AREA AFTR 21Z WITH THE POTENTIAL FOR ISOLD TSRA ALONG
IT...BUT COVERAGE WILL BE TOO LIMITED TO MENTION IN TAFS OTHER
THAN A CB GROUP IN PIA...BMI AND CMI IN THE 22Z-02Z TIME FRAME.
FRONTAL BOUNDARY SHOULD THEN SHIFT EAST OF THE TAF SITES AFTR 04Z
WITH VFR CONDITIONS EXPECTED UNTIL LATE TONIGHT WHEN SOME GROUND
FOG MAY DEVELOP IN THE 09Z-12Z TIME FRAME. WILL ADD 4-5SM IN FOG
LATE IN THE FORECAST PERIOD TO COVER THIS POTENTIAL. SFC WINDS
WILL BE GUSTY TODAY OUT OF THE SOUTH TO SOUTHWEST WITH PREVAILING
SPEEDS OF 12 TO 17 KTS...AND GUSTS IN THE 25 TO 30 KT RANGE LATE
THIS MRNG INTO THIS AFTN. WINDS SHOULD VEER MORE INTO A WESTERLY
DIRECTION LATE THIS AFTN AND EVENING AND THEN BEGIN TO DIMINISH
AFTR DARK.
SMITH
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
229 AM CDT MON MAR 12 2012
.DISCUSSION...
ISSUED 227 AM CDT MON MAR 12 2012
UPPER LOW CLEARLY EVIDENT IN INFRARED AND WATER VAPOR SATELLITE
IMAGERY...CENTERED OVER EASTERN NEBRASKA. DRY SLOT HAS PUSHED
ACROSS MUCH OF THE CWA...REDUCING THE RAIN TO SCATTERED SHOWERS.
THE EXTENT OF THE LINGERING RAIN IS THE INITIAL FORECAST CONCERN...
BUT THE PRIMARY FOCUS IS THE EXTENDED PERIOD OF ABNORMALLY WARM
WEATHER FOR MID MARCH.
SHORT TERM...TODAY THROUGH WEDNESDAY...
00Z MODELS ARE IN GOOD AGREEMENT WITH TRACKING THE LOW INTO WEST
CENTRAL WISCONSIN BY LATE MORNING...THEN TO THE UPPER PENINSULA OF
MICHIGAN BY EARLY EVENING. LINGERING SHOWERS ACROSS THE EASTERN
CWA SHOULD BE OUT OF THE AREA BY MID TO LATE MORNING. NORTHERN CWA
IS A BIT MORE QUESTIONABLE...AS NAM AND HRRR BOTH SHOWING SOME
INSTABILITY SHOWERS REFORMING IN THE COLDER AIR ALOFT. BOTH MODELS
SHOWING THE BEST RAIN CHANCES IN OUR NORTHERN CWA IN THE MORNING...
BUT WILL LINGER SOME SLIGHT CHANCES THERE INTO THE AFTERNOON AS
WELL.
UPPER RIDGING ACROSS THE CENTRAL U.S. BEGINS IN EARNEST LATER
TONIGHT AND PERSISTS MUCH OF THE WEEK. START OF THE WARMING TREND
BEGINS TODAY AND BY WEDNESDAY...WE WILL LIKELY BE SEEING 80 DEGREE
TEMPERATURES IN SEVERAL LOCATIONS. MOST RECORD HIGHS ON WEDNESDAY
ARE IN THE 74-78 RANGE...WITH SOME LOWER 80S ACROSS THE
SOUTHEAST...SO WILL LIKELY SEE SEVERAL RECORDS FALL. MODELS ARE
SOMEWHAT INCONSISTENT WITH SHOWER/THUNDERSTORM POTENTIAL ON
WEDNESDAY WITH THE RIDGE IN PLACE...BUT RAIN CHANCES INCREASE
WEDNESDAY NIGHT AS A WEAKENING BOUNDARY DROPS INTO THE AREA.
LONG TERM...THURSDAY THROUGH SUNDAY...
850 MB TEMPERATURES REMAIN CLOSE TO +12C THROUGH THE PERIOD...AS
THE UPPER RIDGE GRADUALLY SHIFTS TO THE EAST COAST. HOWEVER...CLOUD
COVER WILL BE MORE OF A FACTOR...AS WEAK WAVES IN THE UPPER FLOW
BRING PERIODIC CHANCES OF SHOWERS AND STORMS. HAVE KEPT HIGHS WELL
INTO THE 70S THROUGH THE PERIOD...BUT HAVE NOT GONE AS AGGRESSIVE
AS WEDNESDAY DUE TO THIS ISSUE.
GEELHART
&&
.AVIATION...
ISSUED 1150 PM CDT SUN MAR 11 2012
CEILINGS HAVE GRADUALLY LOWERED THIS EVENING AS LIGHT RAIN
OVERSPREADS THE AREA. EXPECT THIS TREND TO CONTINUE AS MOISTURE
CONTINUE INCREASES UNDER A 45-55 KT LOW LEVEL JET. SATELLITE LOOPS
SHOW THE DRY SLOT ROTATING AROUND THE NORTHERN KS UPPER LOW AND
COMING ABOUT MIDWAY THROUGH MO/AR. AS THIS CONTINUES EASTWARD INTO
IL...EXPECT RAIN TO BECOME MORE SPOTTY AND WILL LIKELY TRANSITION TO
MORE OF A DRIZZLE SITUATION AS MID/UPPER LEVEL MOISTURE IS PUSHED
OUT. FURTHER BEHIND THE DEEP-LAYER DRY SLOT...SKIES ARE BEGINNING TO
CLEAR OVER SOUTHEAST KS/NORTHEAST OK/SOUTHWESTERN MO. COMBINATION OF
MODEL TIMING AND EXTRAPOLATION USED TO TIME THE CLEARING INTO THE
SOUTHWEST AROUND 11Z...CONTINUING ACROSS THE REMAINDER OF THE TAF
SITES BEFORE 14Z. AFTER THAT...STRATOCU SHOULD INCREASE AGAIN AS
INSOLATION WORKS ON THE REMAINING LOW LEVEL MOISTURE AND DEEP
CYCLONIC FLOW. AFTER A MORNING LULL... WINDS WILL ALSO BE PICKING UP
BY MIDDAY WITH SOUTH-SOUTHWEST WINDS 18-22KT GUSTING ABOVE 30 KT AT
TIMES. SURFACE TROUGH WILL THEN COME THROUGH CENTRAL IL 00Z-04Z AND
CLEAR OUT THE CLOUDS AND BRING DECREASED WESTERLY WINDS.
04
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
655 PM EDT MON MAR 12 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISOLATED SHOWERS AND THUNDERSTORMS WILL REMAIN POSSIBLE THROUGH
TONIGHT...AS A WEAK FRONTAL BOUNDARY PASSES THROUGH THE LOWER GREAT
LAKES. HIGH PRESSURE WILL THEN BUILD IN THROUGH MIDWEEK...BRINGING
DRY AND UNSEASONABLY WARM WEATHER. CHANCES FOR SHOWERS AND
THUNDERSTORMS RETURN BEGINNING WEDNESDAY NIGHT AND CONTINUING INTO
THE WEEKEND...AS MOISTURE INCREASES AND A FRONTAL BOUNDARY BECOMES
NEARLY STATIONARY NORTH OF THE FORECAST AREA.
&&
.NEAR TERM /REST OF TODAY/...
PRECIP IS ISOLATED IN NATURE AT THIS TIME WITH ONLY SOME LIGHT
SHOWERS ACROSS THE FAR SOUTHERN COUNTIES. HOWEVER...WILL KEEP
CHANCE POPS IN GRIDS THROUGH EARLY AFTERNOON. DRY SLOT WILL THEN
WORK ITS WAY INTO FORECAST AREA PUTTING AN END TO THE PRECIP
ACROSS MOST OF THE AREA. DID LEAVE SLIGHT CHANCE POPS ACROSS THE
NORTHERN PORTIONS IN CASE ANY OF THE PRECIP OVER NORTHERN INDIANA
MAKES ITS WAY INTO THOSE COUNTIES.
TEMPERATURES ACROSS CENTRAL INDIANA ARE CURRENTLY IN THE UPPER
50S/LOW 60S. NO CHANGES TO FORECASTED HIGHS. UPPER 60S ARE
EXPECTED ACROSS THE EASTERN PORTIONS WHERE CLOUD COVER AND PRECIP
WILL LINGER LONGEST. ELSEWHERE...HIGHS SHOULD CLIMB INTO THE LOW
70S AFTER DRY SLOT MOVES IN AND SUN BREAKS OUT THIS AFTERNOON.
UPDATED GRIDS HAVE BEEN SENT.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
THE MAIN FOCUS OF THIS SHORT TERM FORECAST WILL CONTINUE TO REMAIN
ON THE UNSEASONABLY WARM TEMPERATURES AND POP CHANCES TOWARD THE END
OF THE SHORT TERM TIMEFRAME.
THE PERIOD BEGINS WITH AN UPPER LOW OVER THE WESTERN GREAT LAKES
TREKKING TO THE EAST NORTHEAST WITH ITS ASSOCIATED SURFACE FRONT
FROM NORTHWEST INDIANA DOWN THROUGH CENTRAL ILLINOIS. THE MAJORITY
OF THE PRECIPITATION WITH THIS SYSTEM WILL HAVE PUSHED FURTHER EAST
WITH THE FORECAST AREA UNDER THE INFLUENCE OF THE DRY SLOT.
HOWEVER...MODEL GUIDANCE CURRENTLY ILLUSTRATES LOW LEVEL MOISTURE
HANGING ON ESPECIALLY ACROSS THE SOUTHWESTERN HALF OF THE FORECAST
AREA...AS EVIDENCED BY LOW CONDENSATION PRESSURE DEFICITS AT 925 MB
AND THE 1000-925 MB LAYER. KEPT AND EXPANDED SOUTHWARD THE SLIGHT
CHANCE POP FOR TONIGHT AS THE FRONT MAKES ITS WAY THROUGH THE AREA.
CONFIDENCE NOT HIGH THAT RAIN WILL MAKE IT INTO THE FORECAST AREA.
UPPER RIDGE AND SURFACE HIGH PRESSURE MOVES TOWARD THE AREA TUESDAY
AND TUESDAY NIGHT...BRINGING DRY CONDITIONS TO THE OHIO VALLEY.
UNSEASONABLY WARM TEMPERATURES ARE EXPECTED TO CONTINUE THROUGH THE
ENTIRE SHORT RANGE...WITH A GRADUAL WARMING ON WEDNESDAY AS THE SFC
HIGH PRESSES EAST AND S/SW WINDS RETURN. NOT MUCH CHANGE TO TEMPS AS
THEY MATCHED UP WELL WITH MOS GUIDANCE. STAYED ON THE HIGH SIDE OF
ENSEMBLE MOS SPREAD ON WEDNESDAY AND AFTER.
WITH MINOR UPPER LEVEL DISTURBANCES PUSHING TOWARD THE FORECAST AREA
UNDER SOUTHWEST FLOW ALOFT...POPS MAKE A RETURN TO THE FORECAST AREA
WEDNESDAY NIGHT...OWING TO INCREASING MOISTURE AND ISENTROPIC LIFT
AOA THE 300-305K SFCS. INCREASING GULF MOISTURE AND AT LEAST MODEST
INSTABILITY IS EXPECTED WEDNESDAY NIGHT THROUGH THURSDAY.
THUS...KEPT THUNDER GOING IN WX GRIDS. ON THURSDAY AFTN...THE NAM
FCST SOUNDINGS HAS 2500-3000 J/KG OF CAPE FORECAST WITH A MEAGER
20KT 0-6KM BULK SHEAR...WHILE THE GFS IS LESS BULLISH WITH THE CAPE
AOA 900 J/KG. IF THE NAM PANS OUT AND CONVECTIVE TEMPERATURES ARE
REACHED...ISOLATED SEVERE MAY BE POSSIBLE ON THURSDAY. LARGE HAIL
BEING THE MAIN THREAT WITH A FREEZING LEVEL FROM 9-10K. RIGHT NOW
CONFIDENCE IS LOW IN THIS SCENARIO...AS MODEL FORECAST SOUNDINGS
DISAGREE. WILL CONTINUE TO MONITOR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MODELS INDICATE AN UPPER AIR DISTURBANCE WILL BE MOVING ACROSS OUR
REGION EARLY IN THE EXTENDED PERIOD AND WILL AFFECT OUR
WEATHER...ESPECIALLY THURSDAY NIGHT. WILL MENTION LIKELY POPS
HERE. OTHERWISE IT IS HARD TO KEY ON ANYTHING ONE SYSTEM FRIDAY
THROUGH SATURDAY EXCEPT MODELS HAVE US UNDER A WARM HUMID AIRMASS
AND CONTINUALLY ARE PRODUCING QPF ACROSS OUR REGION AND WILL
CONTINUE CHANCE POPS HERE..
ENSEMBLES AMPLIFY THE UPPER RIDGE STRONGLY ACROSS OUR REGION EARLY
NEXT WEEK AS A STRONG UPPER TROUGH MOVES INTO THE WESTERN U.S. WILL
CONTINUE WITH A DRY FORECAST FOR SUNDAY AND I HAVE DOUBTS ABOUT ANY
PRECIP MONDAY GIVEN THE STRENGTH OF THE UPPER HIGH. FOR NOW WILL
ONLY MENTION 20 PERCENT POPS FOR MONDAY.
AS FAR AS TEMPERATURES ARE CONCERNED...FOLLOWED ALL BLEND NUMBERS
EARLY ON AND THEN WENT WITH A MIX OF HPC AND ALL BLEND NUMBERS FROM
THE WEEKEND ON. I SUSPECT ALL BLEND MAY BE A BIT COOL DURING THE
DAY AND A BIT TOO WARM AT NIGHT SUNDAY AND MONDAY GIVEN THAT THE
AIRMASS WILL BE DRYING OUT SOME.
&&
.AVIATION /DISCUSSION FOR 130000Z TAF ISSUANCE/...
WIND GUSTS OUT OF THE SOUTHWEST OF 20-30 KTS SHOULD BE DROPPING
OFF AROUND THE TIME OF ISSUANCE BUT MAY SEE ISOLATED GUSTS HANG
ON THROUGH 0-1Z BEFORE DROPPING OFF COMPLETELY. SUSTAINED WINDS
WILL DROP DURING THE NIGHT TO AROUND 5 - 10KTS BY 6Z. WHILE MAV
SHOWS ONLY A COUPLE OF HOURS OF MVFR MAINLY BASED ON VISIBILITIES
OVERNIGHT...MET NUMBERS BRING IN MVFR AND THEN AROUND 6 HOURS OF
IFR CEILINGS. BOTH NAM AND RUC FORECAST SOUNDINGS SUPPORT THE
INCLUSION OF IFR...AND VSREFS SHOW A MEAN OF MVFR CEILINGS OVER
THE ENTIRE AREA AFTER ABOUT 3-4Z WITH A HIGH PROBABILITY OF IFR
CEILINGS DEVELOPING AT LEAST OVER THE WEST AFTER 6Z. WILL FAVOR A
PREVAILING MVFR SOLUTION WITH PERHAPS THE INCLUSION OF A FEW HOURS
OF TEMPO IFR AT KIND AND KBMG BASED ON THE MORE NUMEROUS
PESSIMISTIC SOLUTIONS. WILL KEEP THE WESTERN SITES OUT OF THE IFR
AS CEILINGS MAY NOT BUILD BACK THAT FAR. CEILINGS SHOULD BE COMING
BACK UP TO VFR BETWEEN 12 AND 15Z. ON ANOTHER NOTE...MODELS ARE
SHOWING SOME POSSIBILITY THAT KLAF COULD SEE A SHOWER OR
THUNDERSTORM TONIGHT IN THE 3-6Z TIMEFRAME AT THE TAIL END OF A
SQUALL LINE HEADING THROUGH MICHIGAN. STILL LOOKS LIKE PROBABILITY
IS LOW ENOUGH TO LEAVE OUT OF FORECAST AT THIS TIME.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MRD
NEAR TERM...TDUD
SHORT TERM...MRD
LONG TERM....JH
AVIATION...CP
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1045 AM EDT MON MAR 12 2012
.UPDATE...
ZONES UPDATED TO REMOVE EARLY MORNING WORDING AND WIND DOWN SHOWER
MENTION.
BULK OF PRECIP HAS SHIFTED NE OF THE AREA. A NARROW BAND OF
SHOWERS WAS LOCATED ON THE LEADING EDGE OF AT LEAST PARTIAL
CLEARING. THIS WILL QUICKLY TRAVERSE THE REMAINDER OF THE AREA AND
EXIT BY 17Z. FOCUS THEN SHIFTS TO THE WEST IN PROXIMITY OF THE
UPPER LOW. LIMITED CLEARING WAS ALREADY UNDERWAY ACROSS PORTIONS
OF CENTRAL ILLINOIS. VIS SAT SHOWING HINTS OF SOME TOWERING CU
DEVELOPMENT JUST EAST OF LINCOLN ILLINOIS. AS TEMPS CONTINUE TO
WARM AND DEWPTS CLIMB INTO THE MID AND UPPER 50S...STAGE WILL BE
SET FOR AT LEAST SCT STORM DEVELOPMENT. NARROW LINE OF CONVECTION
ALREADY FIRING ON EASTERN FRINGE OF COLD AIR ASSOCIATED WITH UPPER
LOW WITH A FEW LIGHTNING STRIKES NOTED. 11Z HRRR KEYS IN ON THIS
AREA WITH EVENTUAL DEVELOPMENT OF AFTERNOON/EVENING CONVECTION
LIKELY INITIATING ON THIS FEATURE. 12Z SWODY1 EXPANDED THE SLGT
RISK ACROSS MOST OF THE FORECAST AREA AND INCREASED PROBS FOR
DAMAGING WINDS. WILL CONTINUE TO MONITOR TRENDS THROUGH EARLY
AFTERNOON FOR CHANGES TO ZONES...INCLUDING POSSIBLE INCLUSION OF
SVR MENTION.
&&
.PREV DISCUSSION... /ISSUED 811 AM EDT MON MAR 12 2012/
AVIATION /12 UTC TAFS/...
WARM FNTL RAIN BAND MOVG NE OF THE AREA THIS MORNING BUT LEAVING
MVFR CIGS IN ITS WAKE. 55KT LLJ OVER INDIANA EARLY THIS MORNING
CONTS THREAT OF SGFNT LLWS. MIDDAY BREAKOUT WITH STRONG HEATING AS
DRY SLOT ENVELOPES NRN IN AND SW WINDS INCREASE WITH GUSTS INTO
UPPER 20S...PERHAPS SETTING STAGE FOR ERLY EVENING CONVECTION
POTNL...ADDED TSGS AT SBN WITH JUST CONTD CB MENTION AT FWA WHERE
CAPPING STILL VERY PSBL.
PREV DISCUSSION
SHORT TERM...
TODAY THROUGH TUESDAY NIGHT. HIGHLY CONDITIONAL FCST WRT CONVECTION
IN SHORT TERM WEIGHS NEGATIVELY ON OVERALL CONFIDENCE. OVERALL NOD
TOWARD NAM IN CAPTURING STRENGTH OF UPSTREAM MIDLVL CIRCULATION/CYCL
CURVED JETLET TO LIFT NEWD FM SERN KS/SWRN MO THIS AM. INITIAL WARM
CONVEYOR BELT RAFL IN STABLE ENVIRON SANS MUCAPE AND GIVEN SHALLOW
OBSERVED 88-D TOPS/POOR IR SIGNAL HAVE SQUELCHED TSRA MENTION THIS
AM. PD OF WDSPRD MVFR STRATOCU IN ORPHANED LLVL MSTR FOR SVRL HOURS
BEFORE MIX OUT INTO DRY SLOT AFFORDS RAPID INSOLATION RESPONSE. MAX
SFC HEATING/DESTABILIZATION ACRS NERN IL/NWRN IN BY LATE AFTN
COINCIDENT WITH PEAK OF SFC DPS SHOULD NOSE INTO MID 50S TO YIELD
MLCAPE AROUND 1000-1250 J/KG PER MODIFIED 21-00 UTC SNDGS ACRS NWRN
CWA. INCREASED CIN/WARM 8-7H WARM LYR SHOULD INHIBIT TSRA CHCS WITH
S/SERN EXTENT THROUGH CWA. UPDRAFT INITIATION LKLY TO PROGRESS BOTH
UPSTREAM AND TO LEE OF SRN LK MI INVOF LK INDUCED THERMAL
CIRCULATIONS/MESOSCALE BOUNDARY INTERACTIONS IN HIGH SHEAR
ENVIRONMENT WITH 50-55KT 0-6KM DEEP LYR SHEAR NWRN CWA TRAILING TO
40 KTS SOUTH. WILL ADDRESS SEVERE POTNL WITH WIND/HAIL AND SIG
LESSER EXTENT TOR IN HWO AND AWAIT INCRSD CONFIDENCE IN
STORM/UPDRAFT MORPHOLOGY TIED TO FINER DETAILS AND CONDITIONAL WRT
ADEQUATE INSTABILITY. STRONGEST HEATING/TIMING OF DRY SLOT MIXOUT
SHOULD BE AFFORDED ACRS NERN IL INTO WRN CWA SUPPORTIVE OF INCRSD
SFC BASED LAPSE RATES NOSING INTO SRN EDGE OF COLD CORE 5H CLOSED
LOW...THOUGH QUITE FARTHER AWAY THAN PREFERRED TORNADIC CONCEPTUAL
MODEL PER DAVIES. LOW WETBULB ZERO HGHTS 7.5-8.5 KFT TO PROVE
EFFICIENT FOR HAIL PRODUCTION/ALBEIT LKLY SMALL DIAMETER. BEST
CONVECTIVE POTNL/HIEST POPS NW STRADDLING EVENING/ERLY TONIGHT
PERIOD IN MORE FAVORABLE SHEAR/INSTABILITY OVERLAP WITH LAKE
BOUNDARY INFLUENCES. CHCS THEN DWINDLE ONCE DOWNSTREAM INSTABILITY
WANES WITH INCRSD DIURNAL COOLING AS SYSTEM CONTS NEWD INTO LK
SUPR/SRN CAN WHILE UNDERGOING PHASING INTO ACCELERATING SRN CAN/NEG
TILT TROF TONIGHT INTO ERLY TUES. THEREAFTER QUITE BENIGN AND WARM
PATTERN WITH UNSEASONABLY HIGH BELTED FLOW/STRONG RIDGING SFC/ALOFT
BUILDING INTO GRTLKS WITH STRONG INSOLATION/DEEP MIXING TO LKLY
OVERCOME ANY BRIEF SHALLOW COOLER AIR INTRUSION FOR SIMILAR MAX
TEMPS ON TUE...W/EXCEPTION OF LAKE SHADOW/ONSHORE COMPONENT FLOW
DY2...TO WHICH WAS REMOVED DY1 GIVEN TDYS DEEP SRLY FLOW.
LONG TERM...
WEDNESDAY THROUGH SUNDAY...A LONG WAVE TROF WILL REMAIN ENTRENCHED
ALONG THE WESTERN NORTH AMERICAN COAST THROUGH THIS PERIOD. THIS
TROF WILL CAUSE LARGE SCALE AMPLIFICATION DOWNSTREAM OVER THE
CENTRAL AND EASTERN CONUS WITH UNSEASONABLY WARM CONDITIONS THROUGH
THE ENTIRE PERIOD. THE CHALLENGE REMAINS WITH TIMING OF INDIVIDUAL
SHORT WAVES IN THE LARGE SCALE PATTERN AS GULF MOISTURE SPREADS
NORTH AND NORTHEAST ACROSS THE OHIO RIVER AND PERSISTS THROUGH THE
PERIOD. FOR THIS PACKAGE...WENT WITH A GENERAL GFS AND CANADIAN
ENSEMBLE BLEND AND USED DAILY FREQUENCIES OF THE PAST CLIMATOLOGICAL
RECORD. MADE JUST MINOR CHANGES TO SHOWER/STORM CHANCES. TEMPERED
HIGHS SOME BUT ESPECIALLY TEMPERED LOWS TO COME BETTER IN LINE WITH
CLIMATOLOGY. LOWS OF 55F OR HIGHER AT FWA FROM MARCH 14 TO 18 HAVE
ONLY OCCURRED TWICE IN THE LAST 110 YEARS. KEPT THUNDER THROUGH MOST
OF THE WEDNESDAY NIGHT THROUGH SATURDAY PERIOD. WIND FLOW SHOULD
STAY RELATIVELY WEAK...BUT MOISTURE WILL PERSIST WITH FAIRLY STEEP
LAPSE RATES.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ043-046.
&&
$$
SHORT TERM...MURPHY
LONG TERM...SKIPPER
AVIATION...MURPHY/JT
UPDATE...FISHER
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
628 AM EDT MON MAR 12 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
RAIN WILL MOVE EAST OF THE REGION BY MIDDAY AS AN UPPER LEVEL
DISTURBANCES TRACKS TO NEAR LAKE SUPERIOR. ISOLATED SHOWERS AND
THUNDERSTORMS WILL REMAIN POSSIBLE THOUGH INTO TONIGHT AS A WEAK
FRONTAL BOUNDARY PASSES THROUGH THE LOWER GREAT LAKES. HIGH PRESSURE
WILL THEN BUILD IN THROUGH MIDWEEK BRINGING DRY AND UNSEASONABLY
WARM WEATHER. CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN BEGINNING
WEDNESDAY NIGHT AND CONTINUING INTO THE WEEKEND AS A FRONTAL
BOUNDARY BECOMES NEARLY STATIONARY ACROSS THE REGION.
&&
.NEAR TERM /TODAY/...
RAIN CURRENTLY EXPANDING ACROSS CENTRAL INDIANA EARLY THIS MORNING.
LOW LEVEL DRY AIR HAS BEEN A SIGNIFICANT IMPEDIMENT TO RAINFALL
COVERAGE AND INTENSITY SO FAR. TEMPS WERE IN THE MID AND UPPER 50S
AS OF 07Z.
HAVE TRENDED TOWARDS THE HRRR WITH RESPECT TO PRECIPITATION TIMING
AND COVERAGE THROUGH MID MORNING AS IT APPEARS TO BE CAPTURING
CURRENT ACTIVITY WELL. AS MENTIONED ABOVE...DRY AIR THROUGH THE
BOUNDARY LAYER HAS REALLY CUT DOWN THE COVERAGE TO RAINFALL FROM
WHAT HAD BEEN PREVIOUSLY THOUGHT. DEWPOINTS AT 07Z REMAIN IN THE 30S
OVER EASTERN COUNTIES WITH QUICK RISES INTO THE 40S AND LOWER 50S
FURTHER WEST AS LOWER LEVELS SATURATE. MOST WIDESPREAD RAINFALL
COVERAGE WILL BE EXPERIENCED THROUGH 12Z WITH STRONGEST ISENTROPIC
LIFT ONGOING AND LOW LEVEL JET TRAVERSING THROUGH THE AREA. WILL
MAINTAIN CATEGORICAL POPS THROUGH DAYBREAK...BUT OVERALL QPF VALUES
WILL BE UNDER 0.25 INCHES. WILL MAINTAIN AN ISOLATED THUNDER MENTION
AS WELL BASED ON SUBTLE LEVELS OF INSTABILITY AND SAID FORCING ALOFT
PRESENT.
MUCH OF THE RAIN WILL SHIFT EAST OF THE FORECAST AREA THROUGH MID
MORNING AS DRIER PUNCH OF AIR SURGES INTO THE REGION FROM THE
SOUTHWEST. WILL HOLD ONTO HIGHEST POPS OVER EASTERN COUNTIES THROUGH
ABOUT 15Z DIMINISHING TO CHANCE OR LOWER THEREAFTER. AS DRIER AIR
PRESSES INTO CENTRAL INDIANA...MODEL SOUNDINGS INDICATE LOW LEVEL
MOISTURE WILL BECOME TRAPPED UNDERNEATH A BOUNDARY LAYER INVERSION.
THIS WOULD SUGGEST STRATOCU LIKELY TO BE SLOW TO DEPART TODAY...
WITH ANY SUNSHINE HOLDING OFF UNTIL THE AFTERNOON AS THE LOWER
LEVELS BEGIN MIXING OUT. ARRIVAL OF A SECOND LOW LEVEL JET THIS
AFTERNOON COMBINED WITH STRATOCU MIXING OUT WILL SET THE STAGE FOR
GUSTY WINDS POSSIBLY TO 30 TO 35 MPH DURING THE AFTERNOON. HAVE HELD
ONTO LOW CHANCE POPS OVER EASTERN COUNTIES THIS AFTERNOON WITH WEAK
INSTABILITY AND LINGERING LOW LEVEL MOISTURE PRESENT. LACK OF
APPRECIABLE FORCING ALOFT HOWEVER SHOULD KEEP ANY CONVECTION THAT
DEVELOPS ISOLATED AT BEST.
TEMPS...LOW LEVEL THERMALS WILL CLIMB FURTHER TODAY WITH THE STRONG
SOUTHWEST FLOW INTO THE OHIO VALLEY. DESPITE THE PRESENCE OF CLOUDS
INTO THE AFTERNOON...MANY LOCATIONS LIKELY TO MAKE IT TO THE 70
DEGREE MARK FOR THE FIRST TIME THIS YEAR. TRENDED A DEGREE OR TWO
ABOVE GUIDANCE IN MOST AREAS.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON TEMPS AS SPRING PREVIEW ARRIVES TO
CENTRAL INDIANA THIS WEEK.
UPPER LOW WILL TRACK THROUGH THE NORTHERN GREAT LAKES TONIGHT WITH A
WEAK SURFACE BOUNDARY PASSING THROUGH THE LOWER GREAT LAKES
OVERNIGHT. EXPECTED CONVECTIVE DEVELOPMENT ACROSS MICHIGAN AND
NORTHERN INDIANA WHERE FORCING ALOFT AND AVAILABLE INSTABILITY WILL
BE GREATER MAY CLIP FAR NORTHERN COUNTIES AND HAVE HELD ONTO
ISOLATED POPS IN THESE AREAS. HOWEVER WITH SHALLOW MOISTURE PROFILES
NOTED ON MODEL SOUNDINGS...BOUNDARY MORE LIKELY TO PASS THROUGH THE
FORECAST AREA UNEVENTFULLY.
SURFACE HIGH PRESSURE EXPANDS INTO THE REGION TUESDAY WITH RIDGING
ALOFT. ANY LINGERING LOWER CLOUDS TUESDAY MORNING WILL DIMINISH AS
INCREASING SUBSIDENCE ABOVE THE BOUNDARY LAYER EXPANDS ACROSS THE
OHIO VALLEY. AS THE HIGH DRIFTS EAST BY WEDNESDAY NIGHT...DEVELOPING
S/SW FLOW THROUGH THE LOW LEVELS WILL BRING INCREASINGLY MOIST AIR
NORTH OUT OF THE GULF OF MEXICO. DESPITE LITTLE IF ANY FORCING ALOFT
WEDNESDAY NIGHT...ISOLATED TO SCATTERED CONVECTIVE DEVELOPMENT IS
EXPECTED AS THE INCREASING MOISTURE AND INSTABILITY INTERACT WITH AN
APPROACHING WEAK FRONTAL BOUNDARY. WILL CARRY 30 POPS OVERNIGHT
WEDNESDAY.
TEMPS...UNSEASONABLY WARM TEMPERATURES THROUGH THE PERIOD AS LOW
LEVEL THERMALS CONTINUE TO RISE WITH 850MB TEMPS APPROACHING 13C AND
15-16C AT 925MB BY WEDNESDAY. HAVE GONE AT OR ABOVE MAVMOS GUIDANCE
BOTH TUESDAY AND WEDNESDAY WITH 70S EXPECTED. HIGH TEMPERATURES MAY
APPROACH NEAR RECORD HIGHS ON WEDNESDAY AND NOT OUT OF THE QUESTION
AT THIS POINT THAT WESTERN COUNTIES FLIRT WITH 80 DEGREES. MOS
GUIDANCE LOOKED REASONABLE FOR LOWS THROUGH THE PERIOD. JUST THE
BEGINNING OF WHAT APPEARS TO BE AN EXTENDED PERIOD OF WELL ABOVE
NORMAL TEMPS FOR CENTRAL INDIANA.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ENSEMBLES SUGGEST UPPER PATTERN WILL BECOME HIGHLY AMPLIFIED
DURING THIS PERIOD. STRONG RIDGING IS EXPECTED TO DEVELOP OVER THE
EASTERN PARTS OF THE COUNTRY...WHILE A DEEP TROUGH WILL DEVELOP OVER
THE WEST COAST. ENSEMBLES SUGGEST AN UPPER DISTURBANCE MAY BE MOVING
THROUGH THE NORTHERN GREAT LAKES AROUND THURSDAY. TOWARDS NEXT
WEEKEND...IT APPEARS THAT A BROAD SOUTHWESTERLY UPPER FLOW WILL
DEVELOP OVER THE LOCAL AREA AHEAD OF WESTERN TROUGH. THIS WILL
RESULT IN THE POSSIBILITY OF EMBEDDED DISTURBANCES EJECTING OUT OF
THE TROUGH...WITH ENSEMBLES SUGGESTING A PRECIPITATION THREAT PRETTY
MUCH ALL THROUGH THE EXTENDED PERIOD. WILL KEEP POPS GOING FROM
THURSDAY THROUGH SATURDAY. INHERITED A DRY FORECAST FOR NEXT
SUNDAY...BUT SOME OF ENSEMBLE MEMBERS AND OPERATIONAL MODELS SUGGEST
AN UNSTABLE AIR MASS AND RESULTANT PRECIPITATION THREAT AT THAT TIME.
WILL CONTINUE TO KEEP SUNDAY DRY FOR NOW...BUT POPS MAY NEED TO BE
ADDED AT A LATER TIME IF TRENDS LEAN TOWARDS A WETTER SOLUTION.
&&
.AVIATION /DISCUSSION FOR THE 121200Z TAFS/...
RADAR TRENDS AND SHORT RANGE MODEL DATA SUGGEST THE MAIN RAIN THREAT
WILL PASS EAST OF KIND/KBMG AROUND 121300Z. OTHERWISE...EXTENSIVE
AREA OF MVFR CEILINGS 015-025 UPSTREAM. MOST OF THESE LOWER CEILINGS
SHOULD MIX OUT BY THE EARLY TO MID AFTERNOON HOURS...ALTHOUGH MODEL
DATA INDICATE THERE MAY BE A PERSISTENT INVERSION AROUND 035 THIS
AFTERNOON. THIS MAY RESULT IN THE MVFR CEILINGS MIXING OUT INTO A
BROKEN DECK AROUND 035 RATHER THAN DISSIPATING COMPLETELY.
POTENTIAL FOR CONVECTIVE DEVELOPMENT MID TO LATE AFTERNOON ACROSS
NORTHERN ILLINOIS OR NORTHWEST INDIANA ALONG AN APPROACHING FRONT.
APPEARS IF ANYTHING DOES DEVELOP...IT SHOULD REMAIN NORTHWEST OF
KLAF...AT LEAST THROUGH 130000Z.
MODEL WIND PROGS INDICATE GOOD POTENTIAL FOR SURFACE WIND GUSTS
25-28KTS FROM 200-220 DEGREES THIS AFTERNOON.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....JAS
AVIATION...JAS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
423 AM EDT MON MAR 12 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
RAIN WILL MOVE EAST OF THE REGION BY MIDDAY AS AN UPPER LEVEL
DISTURBANCES TRACKS TO NEAR LAKE SUPERIOR. ISOLATED SHOWERS AND
THUNDERSTORMS WILL REMAIN POSSIBLE THOUGH INTO TONIGHT AS A WEAK
FRONTAL BOUNDARY PASSES THROUGH THE LOWER GREAT LAKES. HIGH PRESSURE
WILL THEN BUILD IN THROUGH MIDWEEK BRINGING DRY AND UNSEASONABLY
WARM WEATHER. CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN BEGINNING
WEDNESDAY NIGHT AND CONTINUING INTO THE WEEKEND AS A FRONTAL
BOUNDARY BECOMES NEARLY STATIONARY ACROSS THE REGION.
&&
.NEAR TERM /TODAY/...
RAIN CURRENTLY EXPANDING ACROSS CENTRAL INDIANA EARLY THIS MORNING.
LOW LEVEL DRY AIR HAS BEEN A SIGNIFICANT IMPEDIMENT TO RAINFALL
COVERAGE AND INTENSITY SO FAR. TEMPS WERE IN THE MID AND UPPER 50S
AS OF 07Z.
HAVE TRENDED TOWARDS THE HRRR WITH RESPECT TO PRECIPITATION TIMING
AND COVERAGE THROUGH MID MORNING AS IT APPEARS TO BE CAPTURING
CURRENT ACTIVITY WELL. AS MENTIONED ABOVE...DRY AIR THROUGH THE
BOUNDARY LAYER HAS REALLY CUT DOWN THE COVERAGE TO RAINFALL FROM
WHAT HAD BEEN PREVIOUSLY THOUGHT. DEWPOINTS AT 07Z REMAIN IN THE 30S
OVER EASTERN COUNTIES WITH QUICK RISES INTO THE 40S AND LOWER 50S
FURTHER WEST AS LOWER LEVELS SATURATE. MOST WIDESPREAD RAINFALL
COVERAGE WILL BE EXPERIENCED THROUGH 12Z WITH STRONGEST ISENTROPIC
LIFT ONGOING AND LOW LEVEL JET TRAVERSING THROUGH THE AREA. WILL
MAINTAIN CATEGORICAL POPS THROUGH DAYBREAK...BUT OVERALL QPF VALUES
WILL BE UNDER 0.25 INCHES. WILL MAINTAIN AN ISOLATED THUNDER MENTION
AS WELL BASED ON SUBTLE LEVELS OF INSTABILITY AND SAID FORCING ALOFT
PRESENT.
MUCH OF THE RAIN WILL SHIFT EAST OF THE FORECAST AREA THROUGH MID
MORNING AS DRIER PUNCH OF AIR SURGES INTO THE REGION FROM THE
SOUTHWEST. WILL HOLD ONTO HIGHEST POPS OVER EASTERN COUNTIES THROUGH
ABOUT 15Z DIMINISHING TO CHANCE OR LOWER THEREAFTER. AS DRIER AIR
PRESSES INTO CENTRAL INDIANA...MODEL SOUNDINGS INDICATE LOW LEVEL
MOISTURE WILL BECOME TRAPPED UNDERNEATH A BOUNDARY LAYER INVERSION.
THIS WOULD SUGGEST STRATOCU LIKELY TO BE SLOW TO DEPART TODAY...
WITH ANY SUNSHINE HOLDING OFF UNTIL THE AFTERNOON AS THE LOWER
LEVELS BEGIN MIXING OUT. ARRIVAL OF A SECOND LOW LEVEL JET THIS
AFTERNOON COMBINED WITH STRATOCU MIXING OUT WILL SET THE STAGE FOR
GUSTY WINDS POSSIBLY TO 30 TO 35 MPH DURING THE AFTERNOON. HAVE HELD
ONTO LOW CHANCE POPS OVER EASTERN COUNTIES THIS AFTERNOON WITH WEAK
INSTABILITY AND LINGERING LOW LEVEL MOISTURE PRESENT. LACK OF
APPRECIABLE FORCING ALOFT HOWEVER SHOULD KEEP ANY CONVECTION THAT
DEVELOPS ISOLATED AT BEST.
TEMPS...LOW LEVEL THERMALS WILL CLIMB FURTHER TODAY WITH THE STRONG
SOUTHWEST FLOW INTO THE OHIO VALLEY. DESPITE THE PRESENCE OF CLOUDS
INTO THE AFTERNOON...MANY LOCATIONS LIKELY TO MAKE IT TO THE 70
DEGREE MARK FOR THE FIRST TIME THIS YEAR. TRENDED A DEGREE OR TWO
ABOVE GUIDANCE IN MOST AREAS.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON TEMPS AS SPRING PREVIEW ARRIVES TO
CENTRAL INDIANA THIS WEEK.
UPPER LOW WILL TRACK THROUGH THE NORTHERN GREAT LAKES TONIGHT WITH A
WEAK SURFACE BOUNDARY PASSING THROUGH THE LOWER GREAT LAKES
OVERNIGHT. EXPECTED CONVECTIVE DEVELOPMENT ACROSS MICHIGAN AND
NORTHERN INDIANA WHERE FORCING ALOFT AND AVAILABLE INSTABILITY WILL
BE GREATER MAY CLIP FAR NORTHERN COUNTIES AND HAVE HELD ONTO
ISOLATED POPS IN THESE AREAS. HOWEVER WITH SHALLOW MOISTURE PROFILES
NOTED ON MODEL SOUNDINGS...BOUNDARY MORE LIKELY TO PASS THROUGH THE
FORECAST AREA UNEVENTFULLY.
SURFACE HIGH PRESSURE EXPANDS INTO THE REGION TUESDAY WITH RIDGING
ALOFT. ANY LINGERING LOWER CLOUDS TUESDAY MORNING WILL DIMINISH AS
INCREASING SUBSIDENCE ABOVE THE BOUNDARY LAYER EXPANDS ACROSS THE
OHIO VALLEY. AS THE HIGH DRIFTS EAST BY WEDNESDAY NIGHT...DEVELOPING
S/SW FLOW THROUGH THE LOW LEVELS WILL BRING INCREASINGLY MOIST AIR
NORTH OUT OF THE GULF OF MEXICO. DESPITE LITTLE IF ANY FORCING ALOFT
WEDNESDAY NIGHT...ISOLATED TO SCATTERED CONVECTIVE DEVELOPMENT IS
EXPECTED AS THE INCREASING MOISTURE AND INSTABILITY INTERACT WITH AN
APPROACHING WEAK FRONTAL BOUNDARY. WILL CARRY 30 POPS OVERNIGHT
WEDNESDAY.
TEMPS...UNSEASONABLY WARM TEMPERATURES THROUGH THE PERIOD AS LOW
LEVEL THERMALS CONTINUE TO RISE WITH 850MB TEMPS APPROACHING 13C AND
15-16C AT 925MB BY WEDNESDAY. HAVE GONE AT OR ABOVE MAVMOS GUIDANCE
BOTH TUESDAY AND WEDNESDAY WITH 70S EXPECTED. HIGH TEMPERATURES MAY
APPROACH NEAR RECORD HIGHS ON WEDNESDAY AND NOT OUT OF THE QUESTION
AT THIS POINT THAT WESTERN COUNTIES FLIRT WITH 80 DEGREES. MOS
GUIDANCE LOOKED REASONABLE FOR LOWS THROUGH THE PERIOD. JUST THE
BEGINNING OF WHAT APPEARS TO BE AN EXTENDED PERIOD OF WELL ABOVE
NORMAL TEMPS FOR CENTRAL INDIANA.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ENSEMBLES SUGGEST UPPER PATTERN WILL BECOME HIGHLY AMPLIFIED
DURING THIS PERIOD. STRONG RIDGING IS EXPECTED TO DEVELOP OVER THE
EASTERN PARTS OF THE COUNTRY...WHILE A DEEP TROUGH WILL DEVELOP OVER
THE WEST COAST. ENSEMBLES SUGGEST AN UPPER DISTURBANCE MAY BE MOVING
THROUGH THE NORTHERN GREAT LAKES AROUND THURSDAY. TOWARDS NEXT
WEEKEND...IT APPEARS THAT A BROAD SOUTHWESTERLY UPPER FLOW WILL
DEVELOP OVER THE LOCAL AREA AHEAD OF WESTERN TROUGH. THIS WILL
RESULT IN THE POSSIBILITY OF EMBEDDED DISTURBANCES EJECTING OUT OF
THE TROUGH...WITH ENSEMBLES SUGGESTING A PRECIPITATION THREAT PRETTY
MUCH ALL THROUGH THE EXTENDED PERIOD. WILL KEEP POPS GOING FROM
THURSDAY THROUGH SATURDAY. INHERITED A DRY FORECAST FOR NEXT
SUNDAY...BUT SOME OF ENSEMBLE MEMBERS AND OPERATIONAL MODELS SUGGEST
AN UNSTABLE AIR MASS AND RESULTANT PRECIPITATION THREAT AT THAT TIME.
WILL CONTINUE TO KEEP SUNDAY DRY FOR NOW...BUT POPS MAY NEED TO BE
ADDED AT A LATER TIME IF TRENDS LEAN TOWARDS A WETTER SOLUTION.
&&
.AVIATION /DISCUSSION FOR THE 120900Z KIND TAF UPDATE/...
BASED ON RADAR TRENDS...PRECIPITATION EXPECTED TO BECOME MORE
INTERMITTENT IN NATURE IN THE VICINITY OF KIND THROUGH THE MID
MORNING HOURS. LOWER CEILINGS AROUND 015 HAVE BEEN SLOW TO
MATERIALIZE SO FAR...BUT ARE BEGINNING TO SHOW UP OVER EASTERN
ILLINOIS AND FAR WESTERN INDIANA. WILL BACK OFF ON THE ARRIVAL OF
THESE LOWER CEILINGS TO AROUND SUNRISE. COULD BE SOME SURFACE WIND
GUSTS 20-22KTS FROM 160-180 HEADINGS DEVELOPING OVER THE NEXT COUPLE
OF HOURS BASED ON OBSERVATIONS UPSTREAM. PREVIOUS DISCUSSION
FOLLOWS.
VFR...BECOMING MVFR EARLY THIS MORNING AND THEN BACK TO VFR BY
EARLY AFTERNOON.
CEILINGS AND VISIBILITIES WILL BEGIN LOWER TO MVFR AFTER 06Z AS A
FRONTAL BOUNDARY APPROACHES THE REGION AND THEN LIFTS NORTH OVER THE
STATE EARLY TODAY. NUMEROUS SHOWERS (NOTED UPSTREAM) WILL OCCUR WITH
THIS FEATURE. AN ISOLATED THUNDER SHOWER IS ALSO POSSIBLE (MOSTLY
ELEVATED CONVECTION)...THROUGH EARLY THIS MORNING. HOWEVER CHANCES
REMAIN TOO LOW TO MENTION. DRIER AIR BEHIND FRONT WILL BEGIN TO WORK
IN TO OUR REGION AFTER MID MORNING AND CEILINGS AND VISIBILITIES
WILL IMPROVE AFTER THAT. (AROUND 16-18Z). MID MORNING WINDS WILL
INCREASE AND BE SOUTH TO SOUTHWEST AROUND 15 KNOTS WITH GUSTS TO
25 KNOTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....JAS
AVIATION...SMF/JAS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
331 AM EDT MON MAR 12 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE
BEEN UPDATED BELOW.
&&
.SYNOPSIS...
RAIN WILL MOVE EAST OF THE REGION BY MIDDAY AS AN UPPER LEVEL
DISTURBANCES TRACKS TO NEAR LAKE SUPERIOR. ISOLATED SHOWERS AND
THUNDERSTORMS WILL REMAIN POSSIBLE THOUGH INTO TONIGHT AS A WEAK
FRONTAL BOUNDARY PASSES THROUGH THE LOWER GREAT LAKES. HIGH PRESSURE
WILL THEN BUILD IN THROUGH MIDWEEK BRINGING DRY AND UNSEASONABLY
WARM WEATHER. CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN BEGINNING
WEDNESDAY NIGHT AND CONTINUING INTO THE WEEKEND AS A FRONTAL
BOUNDARY BECOMES NEARLY STATIONARY ACROSS THE REGION.
&&
.NEAR TERM /TODAY/...
RAIN CURRENTLY EXPANDING ACROSS CENTRAL INDIANA EARLY THIS MORNING.
LOW LEVEL DRY AIR HAS BEEN A SIGNIFICANT IMPEDIMENT TO RAINFALL
COVERAGE AND INTENSITY SO FAR. TEMPS WERE IN THE MID AND UPPER 50S
AS OF 07Z.
HAVE TRENDED TOWARDS THE HRRR WITH RESPECT TO PRECIPITATION TIMING
AND COVERAGE THROUGH MID MORNING AS IT APPEARS TO BE CAPTURING
CURRENT ACTIVITY WELL. AS MENTIONED ABOVE...DRY AIR THROUGH THE
BOUNDARY LAYER HAS REALLY CUT DOWN THE COVERAGE TO RAINFALL FROM
WHAT HAD BEEN PREVIOUSLY THOUGHT. DEWPOINTS AT 07Z REMAIN IN THE 30S
OVER EASTERN COUNTIES WITH QUICK RISES INTO THE 40S AND LOWER 50S
FURTHER WEST AS LOWER LEVELS SATURATE. MOST WIDESPREAD RAINFALL
COVERAGE WILL BE EXPERIENCED THROUGH 12Z WITH STRONGEST ISENTROPIC
LIFT ONGOING AND LOW LEVEL JET TRAVERSING THROUGH THE AREA. WILL
MAINTAIN CATEGORICAL POPS THROUGH DAYBREAK...BUT OVERALL QPF VALUES
WILL BE UNDER 0.25 INCHES. WILL MAINTAIN AN ISOLATED THUNDER MENTION
AS WELL BASED ON SUBTLE LEVELS OF INSTABILITY AND SAID FORCING ALOFT
PRESENT.
MUCH OF THE RAIN WILL SHIFT EAST OF THE FORECAST AREA THROUGH MID
MORNING AS DRIER PUNCH OF AIR SURGES INTO THE REGION FROM THE
SOUTHWEST. WILL HOLD ONTO HIGHEST POPS OVER EASTERN COUNTIES THROUGH
ABOUT 15Z DIMINISHING TO CHANCE OR LOWER THEREAFTER. AS DRIER AIR
PRESSES INTO CENTRAL INDIANA...MODEL SOUNDINGS INDICATE LOW LEVEL
MOISTURE WILL BECOME TRAPPED UNDERNEATH A BOUNDARY LAYER INVERSION.
THIS WOULD SUGGEST STRATOCU LIKELY TO BE SLOW TO DEPART TODAY...
WITH ANY SUNSHINE HOLDING OFF UNTIL THE AFTERNOON AS THE LOWER
LEVELS BEGIN MIXING OUT. ARRIVAL OF A SECOND LOW LEVEL JET THIS
AFTERNOON COMBINED WITH STRATOCU MIXING OUT WILL SET THE STAGE FOR
GUSTY WINDS POSSIBLY TO 30 TO 35 MPH DURING THE AFTERNOON. HAVE HELD
ONTO LOW CHANCE POPS OVER EASTERN COUNTIES THIS AFTERNOON WITH WEAK
INSTABILITY AND LINGERING LOW LEVEL MOISTURE PRESENT. LACK OF
APPRECIABLE FORCING ALOFT HOWEVER SHOULD KEEP ANY CONVECTION THAT
DEVELOPS ISOLATED AT BEST.
TEMPS...LOW LEVEL THERMALS WILL CLIMB FURTHER TODAY WITH THE STRONG
SOUTHWEST FLOW INTO THE OHIO VALLEY. DESPITE THE PRESENCE OF CLOUDS
INTO THE AFTERNOON...MANY LOCATIONS LIKELY TO MAKE IT TO THE 70
DEGREE MARK FOR THE FIRST TIME THIS YEAR. TRENDED A DEGREE OR TWO
ABOVE GUIDANCE IN MOST AREAS.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON TEMPS AS SPRING PREVIEW ARRIVES TO
CENTRAL INDIANA THIS WEEK.
UPPER LOW WILL TRACK THROUGH THE NORTHERN GREAT LAKES TONIGHT WITH A
WEAK SURFACE BOUNDARY PASSING THROUGH THE LOWER GREAT LAKES
OVERNIGHT. EXPECTED CONVECTIVE DEVELOPMENT ACROSS MICHIGAN AND
NORTHERN INDIANA WHERE FORCING ALOFT AND AVAILABLE INSTABILITY WILL
BE GREATER MAY CLIP FAR NORTHERN COUNTIES AND HAVE HELD ONTO
ISOLATED POPS IN THESE AREAS. HOWEVER WITH SHALLOW MOISTURE PROFILES
NOTED ON MODEL SOUNDINGS...BOUNDARY MORE LIKELY TO PASS THROUGH THE
FORECAST AREA UNEVENTFULLY.
SURFACE HIGH PRESSURE EXPANDS INTO THE REGION TUESDAY WITH RIDGING
ALOFT. ANY LINGERING LOWER CLOUDS TUESDAY MORNING WILL DIMINISH AS
INCREASING SUBSIDENCE ABOVE THE BOUNDARY LAYER EXPANDS ACROSS THE
OHIO VALLEY. AS THE HIGH DRIFTS EAST BY WEDNESDAY NIGHT...DEVELOPING
S/SW FLOW THROUGH THE LOW LEVELS WILL BRING INCREASINGLY MOIST AIR
NORTH OUT OF THE GULF OF MEXICO. DESPITE LITTLE IF ANY FORCING ALOFT
WEDNESDAY NIGHT...ISOLATED TO SCATTERED CONVECTIVE DEVELOPMENT IS
EXPECTED AS THE INCREASING MOISTURE AND INSTABILITY INTERACT WITH AN
APPROACHING WEAK FRONTAL BOUNDARY. WILL CARRY 30 POPS OVERNIGHT
WEDNESDAY.
TEMPS...UNSEASONABLY WARM TEMPERATURES THROUGH THE PERIOD AS LOW
LEVEL THERMALS CONTINUE TO RISE WITH 850MB TEMPS APPROACHING 13C AND
15-16C AT 925MB BY WEDNESDAY. HAVE GONE AT OR ABOVE MAVMOS GUIDANCE
BOTH TUESDAY AND WEDNESDAY WITH 70S EXPECTED. HIGH TEMPERATURES MAY
APPROACH NEAR RECORD HIGHS ON WEDNESDAY AND NOT OUT OF THE QUESTION
AT THIS POINT THAT WESTERN COUNTIES FLIRT WITH 80 DEGREES. MOS
GUIDANCE LOOKED REASONABLE FOR LOWS THROUGH THE PERIOD. JUST THE
BEGINNING OF WHAT APPEARS TO BE AN EXTENDED PERIOD OF WELL ABOVE
NORMAL TEMPS FOR CENTRAL INDIANA.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ENSEMBLES SUGGEST UPPER PATTERN WILL BECOME HIGHLY AMPLIFIED
DURING THIS PERIOD. STRONG RIDGING IS EXPECTED TO DEVELOP OVER THE
EASTERN PARTS OF THE COUNTRY...WHILE A DEEP TROUGH WILL DEVELOP OVER
THE WEST COAST. ENSEMBLES SUGGEST AN UPPER DISTURBANCE MAY BE MOVING
THROUGH THE NORTHERN GREAT LAKES AROUND THURSDAY. TOWARDS NEXT
WEEKEND...IT APPEARS THAT A BROAD SOUTHWESTERLY UPPER FLOW WILL
DEVELOP OVER THE LOCAL AREA AHEAD OF WESTERN TROUGH. THIS WILL
RESULT IN THE POSSIBILITY OF EMBEDDED DISTURBANCES EJECTING OUT OF
THE TROUGH...WITH ENSEMBLES SUGGESTING A PRECIPITATION THREAT PRETTY
MUCH ALL THROUGH THE EXTENDED PERIOD. WILL KEEP POPS GOING FROM
THURSDAY THROUGH SATURDAY. INHERITED A DRY FORECAST FOR NEXT
SUNDAY...BUT SOME OF ENSEMBLE MEMBERS AND OPERATIONAL MODELS SUGGEST
AN UNSTABLE AIR MASS AND RESULTANT PRECIPITATION THREAT AT THAT TIME.
WILL CONTINUE TO KEEP SUNDAY DRY FOR NOW...BUT POPS MAY NEED TO BE
ADDED AT A LATER TIME IF TRENDS LEAN TOWARDS A WETTER SOLUTION.
&&
.AVIATION /DISCUSSION FOR THE 120600Z TAFS/...
VFR...BECOMING MVFR EARLY THIS MORNING AND THEN BACK TO VFR BY
EARLY AFTERNOON.
CEILINGS AND VISIBILITIES WILL BEGIN LOWER TO MVFR AFTER 06Z AS A
FRONTAL BOUNDARY APPROACHES THE REGION AND THEN LIFTS NORTH OVER THE
STATE EARLY TODAY. NUMEROUS SHOWERS (NOTED UPSTREAM) WILL OCCUR WITH
THIS FEATURE. AN ISOLATED THUNDER SHOWER IS ALSO POSSIBLE (MOSTLY
ELEVATED CONVECTION)...THROUGH EARLY THIS MORNING. HOWEVER CHANCES
REMAIN TOO LOW TO MENTION. DRIER AIR BEHIND FRONT WILL BEGIN TO WORK
IN TO OUR REGION AFTER MID MORNING AND CEILINGS AND VISIBILITIES
WILL IMPROVE AFTER THAT. (AROUND 16-18Z). MID MORNING WINDS WILL
INCREASE AND BE SOUTH TO SOUTHWEST AROUND 15 KNOTS WITH GUSTS TO
25 KNOTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....JAS
AVIATION...SMF/JAS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
310 PM CDT MON MAR 12 2012
.SYNOPSIS...
12Z UA ANALYSIS HAD A 700MB LOW OVER WESTERN MINNESOTA WITH SEVERAL
TROFS RUNNING FROM THE WESTERN GREAT LAKES BACK INTO THE PLAINS. A
MODERATELY STRONG LLJ RAN FROM THE OKLAHOMA PANHANDLE INTO THE GREAT
LAKES. SATELLITE TRENDS SHOWS A VORT MAX MOVING FROM NORTHERN
MISSOURI INTO NORTHERN ILLINOIS WHILE THE MAIN VORT MAX MOVES INTO
NORTHERN WISCONSIN. RADAR SHOWS SPRINKLES OVER THE AREA WITH SOME
LOW CONVECTION OVER NORTHEAST ILLINOIS.
18Z SFC ANALYSIS HAS A WEAK LOW NEAR KDLH WITH A WARM FRONT RUNNING
SOUTHEAST TO NEAR DETROIT. A COLD FRONT RAN FROM THE LOW SOUTH TO
KUIN. DEW POINTS WERE IN THE 50S AND 60S OVER THE GREAT LAKES AND
LOWER MISSISSIPPI VALLEY WITH 30S AND 40S OVER MUCH OF THE PLAINS.
&&
.SHORT TERM...TONIGHT AND TUESDAY...
REFER TO THE CLIMATE SECTION BELOW FOR RECORD HIGHS FOR MARCH 13TH
AND 14TH.
CURRENT OBSERVATIONS THROUGH 20Z COMBINED WITH RECENT RUC TRENDS
INDICATE THE WINDOW OF OPPORTUNITY FOR ANY NEW CONVECTION IS
CLOSING. RADAR INDICATES SPRINKLES WITH SOME VERY MINOR SHOWERS OVER
THE SOUTHEAST HALF OF THE CWFA BUT RUC TRENDS INDICATE THE
INSTABILITY NEEDED TO GET ANYTHING STRONGER GOING WILL END BY 2130Z.
THUS SPRINKLES WITH PERHAPS A FEW SHRA WILL CONTINUE THROUGH SUNSET
WITH POSSIBLY AN ISOLD TSRA IN THE FAR EASTERN/SOUTHEASTERN CWFA.
SATELLITE TRENDS INDICATE THE CLOUDS ARE TAKING ON A MORE CELLULAR
NATURE AND WILL SLOWLY DISSIPATE WITH SUNSET.
SO A CLEARING TREND WILL OCCUR TONIGHT AS THE STORM SYSTEM MOVES
INTO CANADA. HIGH PRESSURE BUILDING INTO THE CWFA LATE TONIGHT WILL
RESULT IN LIGHT WINDS WHICH SHOULD ALLOW TEMPERATURES TO BECOME
CHILLY BUT STILL ABOVE NORMAL.
THE HIGH WILL INITIALLY LIMIT MIXING ON TUESDAY UNTIL IT MOVES EAST
OF THE AREA. RETURN FLOW DEVELOPING BY MID DAY COMBINED WITH THE
STRONG MARCH SUN WILL ALLOW TEMPERATURES TO CLIMB WELL ABOVE NORMAL.
THE NORTHERN THIRD OR SO OF THE CWFA SHOULD REACH THE UPPER 60S WITH
70 TO 75 ELSEWHERE. ..08..
.LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY...
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...BOTH SFC AND UPPER RIDGE
AXIS WILL MIGRATE OFF TO THE EAST OF THE CWA INTO WED MORNING
ALLOWING RETURN FLOW TO INCREASE LATE TUE NIGHT FOR NON-DIURNAL
TEMP CURVES. LOWS WILL PROBABLY OCCUR FROM 03Z-07Z WED BEFORE STEADY
TO SLOW RISE TREND BEGINS. AS SFC FRONT TRIES TO SAG TOWARD THE CWA
FROM THE NORTHWEST...THE CWA WILL BECOME UNDER FULL INFLUENCE OF
WARM THRUST. ONLY THE WET BIASED 12Z GFS BREAKS OUT PRECIP ON WED
BEFORE 00Z THU AND WILL REMOVE ANY DAYTIME POPS. MORE INSOLATION AND
EXTENT OF CURRENTLY PROGGED THERMAL PROFILES SUGGEST HIGHS IN THE
MID TO UPPER 70S ON WED WITH THE SHOT AT A FEW 80S...ALL OF WHICH
WILL BE RECORD HIGH TERRITORY FOR ALL CLIMATE SITES FOR MARCH 14TH.
FLATTENING RIDGE-RIDING VORT WILL COMBINE WITH LLVL MOISTURE
CONVERGENCE ALONG THE INCOMING FRONT FOR A CHANCE AT SOME NOCTURNAL
SHOWERS AND THUNDERSTORMS WED NIGHT. IF A STORM COULD GET GOING IN
THE LOCAL AREA WED AFTERNOON AND EARLY EVENING AND BECOME SOMEWHAT
ORGANIZED...FCST SOUNDINGS SUGGEST A POTENTIAL FOR A SVR STORM WITH
LARGE HAIL AND DAMAGING WIND...BUT AGAIN A TRIGGER DOES NOT APPEAR
UNTIL LATER THAT NIGHT. ALSO THESE SVR PARAMETERS ARE BEING
ADVERTISED ON THE GFS AND ESPECIALLY THE NAM FCST SOUNDINGS WHICH MAY
AGAIN BE OVERDOING BOUNDARY LAYER MOISTURE.
THURSDAY AND FRIDAY...FLATTENING NON-SENSIBLE FLOW ACRS THE
MIDWEST...UNSEASONABLY MILD REGIME CONTINUES WITH LITTLE FOCUS FOR
ORGANIZED CONVECTION. WILL KEEP LOW POPS FOR WDLY SCTRD SHOWERS OR
THUNDERSTORMS POPPING UP IN THE AFTERNOON CAPES. HIGHS IN THE MID TO
UPPER 70S BOTH DAYS AS MAY ARRIVES EARLY.
SATURDAY THROUGH MONDAY...MOST 12Z RUN MEDIUM RANGE SOLUTIONS AND
LATEST ENSEMBLES SUGGEST PATTERN TO BECOME HIGH AMPLITUDE SINE WAVE
PATTERN ACRS THE CONUS...WITH THE MID MS RVR VALLEY STUCK IN THE
MIDDLE FOR THE REST OF THE EXTENDED. WARM MOIST CONVEYOR UP OFF THE
WESTERN GULF TO CONTINUE TO FLOW UP INTO THE REGION TO FUEL POSSIBLE
SHOWER AND THUNDERSTORM ACTIVITY...BUT AGAIN NO REAL SYNOPTICS SCALE
FEATURES TO SUGGEST MORE ORGANIZATION TO THE CONVECTION EVIDENT AT
THIS TIME THROUGH AT LEAST MON NIGHT...POSSIBLY NOT UNTIL MID NEXT
WEEK AS HIGH AMPLITUDE PATTERN SLOW TO MOVE. THUS WILL KEEP LOW
DIURNAL CHANCES FOR WDLY SCTRD UNORGANIZED CONVECTION IN MAINLY
DAYTIME HEATING WHICH MAY LEAD TO HIGHS IN THE MID TO UPPER 70S
EVERY DAY. ..12..
&&
.AVIATION...
MVFR TO VFR CONDITIONS WILL CONTINUE THROUGH 00Z/13 AS A STORM
SYSTEM MOVES INTO CANADA. A DISTURBANCE MOVING FROM MISSOURI INTO
ILLINOIS MIGHT ALLOW SOME SHRA OR ISOLD TSRA TO DVLP EAST OF THE
MISSISSIPPI RIVER PRIOR TO 00Z BUT WILL NOT AFFECT KMLI/KBRL. HIGH
PRESSURE BUILDING INTO THE MIDWEST AFTER 00Z/13 WILL ALLOW VFR
CONDITIONS TO SLOWLY DVLP THROUGH 12Z/13. ..08..
&&
.CLIMATE...
RECORD HIGHS FOR MARCH 13TH...
BURLINGTON........77 IN 2007 AND OTHER YEARS
CEDAR RAPIDS......74 IN 2007
DUBUQUE...........71 IN 2007
MOLINE............77 IN 2007
RECORD HIGHS FOR MARCH 14TH...
BURLINGTON........76 IN 1995
CEDAR RAPIDS......75 IN 1995
DUBUQUE...........72 IN 1995
MOLINE............77 IN 1995
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
08/12
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
136 PM CDT MON MAR 12 2012
.UPDATE...
COLD POOL ALOFT COMBINED WITH CLOUD COVER IS HELPING TO SUPPRESS
TEMPERATURES. SATELLITE AND OBS TRENDS INDICATE THE PUSH OF WARM
TEMPERATURES WILL AT BEST JUST BRUSH THE FAR EASTERN AND POSSIBLY
SOUTHEAST CWFA THIS AFTERNOON. RADAR TRENDS SHOWS NEW CONVECTION
HAS DEVELOPED FROM DE KALB COUNTY BACK INTO NORTHERN BUREAU. RUC
TRENDS USING THE LIFT TOOL SUGGEST POSSIBLE DEVELOPMENT BACK TO
THE SOUTHWEST TO AREAS EAST OF THE MISSISSIPPI. FCST SOUNDINGS ARE
MARGINAL AT BEST TO SUPPORT CONVECTION AND ONLY FOR A NARROW
WINDOW BEFORE A CAP DEVELOPS BY LATE AFTERNOON.
THERE MAY STILL BE A THREAT FOR SMALL HAIL AND GUSTY WINDS THIS
AFTERNOON IN THE FAR EASTERN CWFA AND POSSIBLY THE SOUTHEAST CWFA.
HOWEVER...IF ADDITIONAL HEATING AND INSTABILITY DOES NOT DEVELOP
SOON THEN THAT THREAT WILL BE OVER BY LATE AFTERNOON.
AN UPDATE REFLECTING THE CURRENT TRENDS HAS BEEN SENT.
..08..
&&
.PREV DISCUSSION... /ISSUED 1229 PM CDT MON MAR 12 2012/
AVIATION...
MVFR TO VFR CONDITIONS WILL BE SEEN ACROSS THE AREA THROUGH 00Z/13.
STORM SYSTEM OVER THE MIDWEST WILL SLOWLY MOVE NORTHEAST THIS
AFTERNOON AND TONIGHT. A DISTURBANCE ROTATING AROUND THE STORM MAY
ALLOW SOME TSRA TO DVLP ALONG/EAST OF THE MISSISSIPPI RIVER.
KMLI/KBRL SHOULD HAVE THE BULK OF THE ACTIVITY EAST OF THEM BUT A
CB WORDING WAS INCLUDED WITH THE 18Z TAFS. CONVECTION SHOULD REMAIN
WELL EAST OF KCID/KDBQ. AFT 00Z/13 HIGH PRESSURE WILL BUILD INTO
THE MIDWEST AND ALLOW VFR CONDITIONS TO DEVELOP.
.08..
PREV DISCUSSION... /ISSUED 1047 AM CDT MON MAR 12 2012/
UPDATE...
THE OVERALL FCST HAS BEEN UPDATED TO BETTER REFLECT CURRENT
CONDITIONS. THE RUC SHOWS A NARROW AREA OF F VECTOR CONVERGENCE
FROM ABOUT KBRL TO KDKB WHICH WAS ALSO ALONG A THETA E GRADIENT IN
THE 850-300MB LAYER. THESE FEATURES EXPLAIN THE NARROW BAND OF
CONVECTION WITH A FEW TSRA ASSOCIATED WITH IT. THE REMAINDER OF
THE STRATIFORM RAIN CAN BE EXPLAINED WITH CONVERGENCE IN THE
800-750MB LAYER.
RUC TRENDS SHOW THE CURRENT PRECIP EXITING THE AREA LATE THIS
MORNING. WATER VAPOR INDICATES A VORT MAX ACROSS NORTHERN MISSOURI
THAT WILL ROTATE OVER THE SOUTHEAST HALF OF THE CWFA DURING THE
AFTERNOON HOURS. LIFT TOOL SHOWS STRONG CONVERGENCE DEVELOPING
WITH ANOTHER THETA E GRADIENT ROTATING INTO THE CWFA AS THE COLD
POCKET ALOFT MOVES EAST. THUS SHOWERS SHOULD BE MOST PREVALENT
OVER THE SOUTHEAST HALF OF THE CWFA WITH LOWER CHANCES OVER THE
NORTHWEST HALF OF THE CWFA. FCST SOUNDINGS FROM THE RUC SUGGEST
THAT TSRA WILL BE ALSO POSSIBLE OVER ROUGHLY THE SOUTHEAST HALF OF
THE CWFA AND BASED ON THE PROGGED WBZ HEIGHTS SMALL HAIL MAY BE
POSSIBLE WITH THE STRONGER CELLS.
.08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1229 PM CDT MON MAR 12 2012
.AVIATION...
MVFR TO VFR CONDITIONS WILL BE SEEN ACROSS THE AREA THROUGH 00Z/13.
STORM SYSTEM OVER THE MIDWEST WILL SLOWLY MOVE NORTHEAST THIS
AFTERNOON AND TONIGHT. A DISTURBANCE ROTATING AROUND THE STORM MAY
ALLOW SOME TSRA TO DVLP ALONG/EAST OF THE MISSISSIPPI RIVER.
KMLI/KBRL SHOULD HAVE THE BULK OF THE ACTIVITY EAST OF THEM BUT A
CB WORDING WAS INCLUDED WITH THE 18Z TAFS. CONVECTION SHOULD REMAIN
WELL EAST OF KCID/KDBQ. AFT 00Z/13 HIGH PRESSURE WILL BUILD INTO
THE MIDWEST AND ALLOW VFR CONDITIONS TO DEVELOP.
..08..
&&
.PREV DISCUSSION... /ISSUED 1047 AM CDT MON MAR 12 2012/
UPDATE...
THE OVERALL FCST HAS BEEN UPDATED TO BETTER REFLECT CURRENT
CONDITIONS. THE RUC SHOWS A NARROW AREA OF F VECTOR CONVERGENCE
FROM ABOUT KBRL TO KDKB WHICH WAS ALSO ALONG A THETA E GRADIENT IN
THE 850-300MB LAYER. THESE FEATURES EXPLAIN THE NARROW BAND OF
CONVECTION WITH A FEW TSRA ASSOCIATED WITH IT. THE REMAINDER OF
THE STRATIFORM RAIN CAN BE EXPLAINED WITH CONVERGENCE IN THE
800-750MB LAYER.
RUC TRENDS SHOW THE CURRENT PRECIP EXITING THE AREA LATE THIS
MORNING. WATER VAPOR INDICATES A VORT MAX ACROSS NORTHERN MISSOURI
THAT WILL ROTATE OVER THE SOUTHEAST HALF OF THE CWFA DURING THE
AFTERNOON HOURS. LIFT TOOL SHOWS STRONG CONVERGENCE DEVELOPING
WITH ANOTHER THETA E GRADIENT ROTATING INTO THE CWFA AS THE COLD
POCKET ALOFT MOVES EAST. THUS SHOWERS SHOULD BE MOST PREVALENT
OVER THE SOUTHEAST HALF OF THE CWFA WITH LOWER CHANCES OVER THE
NORTHWEST HALF OF THE CWFA. FCST SOUNDINGS FROM THE RUC SUGGEST
THAT TSRA WILL BE ALSO POSSIBLE OVER ROUGHLY THE SOUTHEAST HALF OF
THE CWFA AND BASED ON THE PROGGED WBZ HEIGHTS SMALL HAIL MAY BE
POSSIBLE WITH THE STRONGER CELLS.
..08..
PREV DISCUSSION... /ISSUED 320 AM CDT MON MAR 12 2012/
SYNOPSIS...
AS EXPECTED WIDESPREAD RAIN IN THE MOIST CONVEYOR BELT MOVED
THROUGH THE DVN CWA DURING THE NIGHT AND HAS FOR THE MOST PART
LIFTED TO THE NORTHEAST OF THE CWA EARLY THIS MORNING. DOPPLER
RADAR ESTIMATES RAINFALL IN THE 1/4 TO 1/2 INCH RANGE WEST OF THE
MS RIVER WITH LESSER AMOUNTS TO THE EAST. OTHERWISE THE UPPER LOW
WAS SPINNING ACROSS WESTERN IA WITH AN AREA OF SHOWERS INTO
CENTRAL IA. THERE WAS ALSO A TRAILING VORT MAX OVER NORTHWEST MO
AND WAS LIFTING TO THE NORTHEAST...AND WAS ALSO PRODUCING SHOWERS.
INCREDIBLY MILD AND MOIST FOR THIS TIME OF NIGHT IN THE MIDDLE OF
MARCH. CURRENT SURFACE DEWPOINTS IN THE CWA WERE IN THE UPPER 40S
TO LOWER 50S WITH TEMPERATURES MAINLY IN THE LOWER TO MID 50S.
HAASE..
SHORT TERM...TODAY AND TONIGHT...
FORECAST FOCUS ON THUNDERSTORM POTENTIAL ESPECIALLY THIS
AFTERNOON...THEN CLEAR AND COOLER TONIGHT.
TODAY...WILL START OUT THE DAY WITH LOW CLOUDS AND SCATTERED
SHOWERS. HOWEVER BY AFTERNOON ENOUGH BREAKS IN THE CLOUDS TO HAVE
A MIX OF CLOUDS AND SUNSHINE TO BOOST TEMPERATURES INTO THE MID
60S NORTH TO LOWER 70S SOUTH. THE COMBINATION OF THE UPPER LOW AND
COLD POCKET LIFTING ACROSS NORTHERN IA AND INTO WISCONSIN TODAY...
AND A TRAILING VORT MAX COMING OUT OF NW MO SHOULD TRIGGER ADDITIONAL
SCATTERED SHOWERS AND EVEN A FEW THUNDERSTORMS. THE BEST COVERAGE
WILL BE IN OUR NORTHERN CWA AND WILL HAVE AT LEAST 50 POPS. WILL
NEED TO KEEP AN EYE ON THUNDERSTORM POTENTIAL THIS AFTERNOON AS
THE VORT MAX LIFTS ACROSS THE CWA IN CONCERT WITH DAYTIME HEATING.
STEEP LAPSE RATES...MODERATE TO STRONG SHEAR WILL BE IN PLACE BUT
CAPES ARE MARGINAL AND A SURFACE LOW IS LACKING TO FOCUS SURFACE
CONVERGENCE. NONETHELESS FREEZING LEVELS OF LESS THAN 8K FT ARE
IDEAL FOR SMALL HAIL AND ANY ROTATING STORM MAY BE ABLE TO PRODUCE
ISOLATED DAMAGING WIND. SPC HAS A SLIGHT RISK FOR SEVERE STORMS
EAST OF THE DVN CWA FROM NORTHEAST IL INTO LOWER MI FOR MAINLY
THIS AFTERNOON. THE VORT MAX SHOULD LIFT AWAY FROM THE DVN CWA BY
LATE AFTERNOON IF NOT SOONER ENDING THE THUNDERSTORM THREAT.
TONIGHT...HIGH PRESSURE RIDGE WITH CLEAR SKIES AND LIGHT WINDS
OVER THE REGION. WITH LOWERING DEWPOINTS MINIMUM TEMPERATURES
SHOULD BOTTOM OUT IN THE UPPER 30S TO MID 40S.
HAASE..
LONG TERM...TUESDAY THROUGH SUNDAY...
THE FORECAST OF A LONG PERIOD OF VERY WARM...POSSIBLY RECORD LEVEL
WARMTH CONTINUES TO BE EXPECTED THROUGHOUT THE ENTIRE EXTENDED
FORECAST...AND BEYOND. A VERY SUMMER-LIKE AIRMASS SHOULD SET UP
TUESDAY...WITH A WEAK FRONTAL CONVERGENCE INTO THE CWA FROM
WEDNESDAY AFTERNOON THROUGH SATURDAY OR SUNDAY. THIS WEAK
CONVERGENCE WILL COMBINE WITH THE EXTREMELY MILD AND MOIST AIRMASS
TO PROVIDE A DAILY THREAT FOR SHOWERS AND STORMS...ALBEIT VERY LOW
DAILY CONFIDENCE IN THEM. I.E. SUMMER-LIKE.
DESPITE SURFACE HIGH PRESSURE AND LIGHT WINDS TUESDAY...THE SUN AND
VERY MILD AIR ALOFT SHOULD AID GETTING MIXING HEIGHTS HIGH ENOUGH TO
TAP INTO THE MILD AIR. THUS...WIDESPREAD UPPER 60S TO MID 70S ARE
FORECAST. WEDNESDAY WILL SEE BETTER MIXING YET...AND MID 70S TO NEAR
80 IS RIGHT ON TRACK FOR NOW...ESPECIALLY SINCE CLOUDS DO NOT LOOK
OPAQUE UNTIL LATE AFTERNOON...WHEN A FEW STORMS COULD FORM ALONG THE
WEAK FRONT.
THIS WEAK FORCING CONTINUES THROUGH THE END OF THE WEEK...WITH VERY
SIMILAR DAYTIME TEMPERATURES UNLESS ORGANIZED STORMS CAN FORM. WITH
SUCH LOW CONFIDENCE IN CONVECTION...OUR TEMPERATURE ARE FORECAST
BELOW THE SUNNY POTENTIAL...BUT WELL ABOVE THE LEVELS IF STORMS
OCCUR IN ANY PERIOD.
LOOKING SLIGHTLY BEYOND...THE UPPER PATTERN BECOMES MORE VOLATILE
WITH VERY FAST WINDS ALOFT AND STRONG FORCING WITH TIME...AND OUR
AIRMASS WILL LIKELY BECOME MORE MOIST AND WARM. THIS COMBINATION
COULD BRING OUR FIRST SEVERE WEATHER TO THE DVN CWA BY EARLY NEXT
WEEK.
ERVIN..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1047 AM CDT MON MAR 12 2012
.UPDATE...
THE OVERALL FCST HAS BEEN UPDATED TO BETTER REFLECT CURRENT
CONDITIONS. THE RUC SHOWS A NARROW AREA OF F VECTOR CONVERGENCE
FROM ABOUT KBRL TO KDKB WHICH WAS ALSO ALONG A THETA E GRADIENT IN
THE 850-300MB LAYER. THESE FEATURES EXPLAIN THE NARROW BAND OF
CONVECTION WITH A FEW TSRA ASSOCIATED WITH IT. THE REMAINDER OF
THE STRATIFORM RAIN CAN BE EXPLAINED WITH CONVERGENCE IN THE
800-750MB LAYER.
RUC TRENDS SHOW THE CURRENT PRECIP EXITING THE AREA LATE THIS
MORNING. WATER VAPOR INDICATES A VORT MAX ACROSS NORTHERN MISSOURI
THAT WILL ROTATE OVER THE SOUTHEAST HALF OF THE CWFA DURING THE
AFTERNOON HOURS. LIFT TOOL SHOWS STRONG CONVERGENCE DEVELOPING
WITH ANOTHER THETA E GRADIENT ROTATING INTO THE CWFA AS THE COLD
POCKET ALOFT MOVES EAST. THUS SHOWERS SHOULD BE MOST PREVALENT
OVER THE SOUTHEAST HALF OF THE CWFA WITH LOWER CHANCES OVER THE
NORTHWEST HALF OF THE CWFA. FCST SOUNDINGS FROM THE RUC SUGGEST
THAT TSRA WILL BE ALSO POSSIBLE OVER ROUGHLY THE SOUTHEAST HALF OF
THE CWFA AND BASED ON THE PROGGED WBZ HEIGHTS SMALL HAIL MAY BE
POSSIBLE WITH THE STRONGER CELLS.
...08..
&&
.AVIATION... /ISSUED 721 AM CDT MON MAR 12 2012/
VFR CONDS SOUTH OF I-80 WITH IFR CONDS TO THE NORTH THIS MORNING.
SCATTERED SHOWERS ALL AREAS THIS MORNING THEN SCATTERED
THUNDERSTORMS THIS AFTERNOON ESPECIALLY NORTH OF INTERSTATE 80.
MVFR CIGS/VIS IN SHOWERS. HIGH PRESSURE RIDGE BRINGS SKC TONIGHT
AND TUESDAY. SOUTH TO SOUTHWEST WINDS 10 TO 20 KNOTS WITH GUSTS TO
25 KNOTS TODAY. NORTHWEST WINDS LESS THAN 10 KNOTS TONIGHT. WINDS
BECOMING SOUTHEAST LESS THAN 10 KNOTS ON TUESDAY.
&&
PREV DISCUSSION... /ISSUED 320 AM CDT MON MAR 12 2012/
SYNOPSIS...
AS EXPECTED WIDESPREAD RAIN IN THE MOIST CONVEYOR BELT MOVED
THROUGH THE DVN CWA DURING THE NIGHT AND HAS FOR THE MOST PART
LIFTED TO THE NORTHEAST OF THE CWA EARLY THIS MORNING. DOPPLER
RADAR ESTIMATES RAINFALL IN THE 1/4 TO 1/2 INCH RANGE WEST OF THE
MS RIVER WITH LESSER AMOUNTS TO THE EAST. OTHERWISE THE UPPER LOW
WAS SPINNING ACROSS WESTERN IA WITH AN AREA OF SHOWERS INTO
CENTRAL IA. THERE WAS ALSO A TRAILING VORT MAX OVER NORTHWEST MO
AND WAS LIFTING TO THE NORTHEAST...AND WAS ALSO PRODUCING SHOWERS.
INCREDIBLY MILD AND MOIST FOR THIS TIME OF NIGHT IN THE MIDDLE OF
MARCH. CURRENT SURFACE DEWPOINTS IN THE CWA WERE IN THE UPPER 40S
TO LOWER 50S WITH TEMPERATURES MAINLY IN THE LOWER TO MID 50S.
HAASE..
SHORT TERM...TODAY AND TONIGHT...
FORECAST FOCUS ON THUNDERSTORM POTENTIAL ESPECIALLY THIS
AFTERNOON...THEN CLEAR AND COOLER TONIGHT.
TODAY...WILL START OUT THE DAY WITH LOW CLOUDS AND SCATTERED
SHOWERS. HOWEVER BY AFTERNOON ENOUGH BREAKS IN THE CLOUDS TO HAVE
A MIX OF CLOUDS AND SUNSHINE TO BOOST TEMPERATURES INTO THE MID
60S NORTH TO LOWER 70S SOUTH. THE COMBINATION OF THE UPPER LOW AND
COLD POCKET LIFTING ACROSS NORTHERN IA AND INTO WISCONSIN TODAY...
AND A TRAILING VORT MAX COMING OUT OF NW MO SHOULD TRIGGER ADDITIONAL
SCATTERED SHOWERS AND EVEN A FEW THUNDERSTORMS. THE BEST COVERAGE
WILL BE IN OUR NORTHERN CWA AND WILL HAVE AT LEAST 50 POPS. WILL
NEED TO KEEP AN EYE ON THUNDERSTORM POTENTIAL THIS AFTERNOON AS
THE VORT MAX LIFTS ACROSS THE CWA IN CONCERT WITH DAYTIME HEATING.
STEEP LAPSE RATES...MODERATE TO STRONG SHEAR WILL BE IN PLACE BUT
CAPES ARE MARGINAL AND A SURFACE LOW IS LACKING TO FOCUS SURFACE
CONVERGENCE. NONETHELESS FREEZING LEVELS OF LESS THAN 8K FT ARE
IDEAL FOR SMALL HAIL AND ANY ROTATING STORM MAY BE ABLE TO PRODUCE
ISOLATED DAMAGING WIND. SPC HAS A SLIGHT RISK FOR SEVERE STORMS
EAST OF THE DVN CWA FROM NORTHEAST IL INTO LOWER MI FOR MAINLY
THIS AFTERNOON. THE VORT MAX SHOULD LIFT AWAY FROM THE DVN CWA BY
LATE AFTERNOON IF NOT SOONER ENDING THE THUNDERSTORM THREAT.
TONIGHT...HIGH PRESSURE RIDGE WITH CLEAR SKIES AND LIGHT WINDS
OVER THE REGION. WITH LOWERING DEWPOINTS MINIMUM TEMPERATURES
SHOULD BOTTOM OUT IN THE UPPER 30S TO MID 40S.
HAASE..
LONG TERM...TUESDAY THROUGH SUNDAY...
THE FORECAST OF A LONG PERIOD OF VERY WARM...POSSIBLY RECORD LEVEL
WARMTH CONTINUES TO BE EXPECTED THROUGHOUT THE ENTIRE EXTENDED
FORECAST...AND BEYOND. A VERY SUMMER-LIKE AIRMASS SHOULD SET UP
TUESDAY...WITH A WEAK FRONTAL CONVERGENCE INTO THE CWA FROM
WEDNESDAY AFTERNOON THROUGH SATURDAY OR SUNDAY. THIS WEAK
CONVERGENCE WILL COMBINE WITH THE EXTREMELY MILD AND MOIST AIRMASS
TO PROVIDE A DAILY THREAT FOR SHOWERS AND STORMS...ALBEIT VERY LOW
DAILY CONFIDENCE IN THEM. I.E. SUMMER-LIKE.
DESPITE SURFACE HIGH PRESSURE AND LIGHT WINDS TUESDAY...THE SUN AND
VERY MILD AIR ALOFT SHOULD AID GETTING MIXING HEIGHTS HIGH ENOUGH TO
TAP INTO THE MILD AIR. THUS...WIDESPREAD UPPER 60S TO MID 70S ARE
FORECAST. WEDNESDAY WILL SEE BETTER MIXING YET...AND MID 70S TO NEAR
80 IS RIGHT ON TRACK FOR NOW...ESPECIALLY SINCE CLOUDS DO NOT LOOK
OPAQUE UNTIL LATE AFTERNOON...WHEN A FEW STORMS COULD FORM ALONG THE
WEAK FRONT.
THIS WEAK FORCING CONTINUES THROUGH THE END OF THE WEEK...WITH VERY
SIMILAR DAYTIME TEMPERATURES UNLESS ORGANIZED STORMS CAN FORM. WITH
SUCH LOW CONFIDENCE IN CONVECTION...OUR TEMPERATURE ARE FORECAST
BELOW THE SUNNY POTENTIAL...BUT WELL ABOVE THE LEVELS IF STORMS
OCCUR IN ANY PERIOD.
LOOKING SLIGHTLY BEYOND...THE UPPER PATTERN BECOMES MORE VOLATILE
WITH VERY FAST WINDS ALOFT AND STRONG FORCING WITH TIME...AND OUR
AIRMASS WILL LIKELY BECOME MORE MOIST AND WARM. THIS COMBINATION
COULD BRING OUR FIRST SEVERE WEATHER TO THE DVN CWA BY EARLY NEXT
WEEK.
ERVIN..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
228 PM CDT MON MAR 12 2012
...UPDATED LONG TERM DISCUSSION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 347 AM CDT MON MAR 12 2012
MAIN FORECAST CONCERN DURING THE SHORT TERM WILL BE AREAS OF DENSE
FOG OVER SOUTH CENTRAL KANSAS EARLY THIS MORNING. LOW CLOUD
ENHANCEMENT CHANNEL HAS BEEN SHOWING AREAS OF FOG WITH SOME PATCHY
DENSE FOG GENERALLY ALONG AND EAST OF HIGHWAY 183 SINCE BEFORE
MIDNIGHT. IN THE PAST HOUR THIS AREA HAS EXPANDED AND FILLED IN
CONSIDERABLY WITH AWOS OBS INDICATING A QUARTER MILE OR LESS AT
PRATT AND MEDICINE LODGE. HRRR VISIBILITY HAS BEEN HINTING AT THIS
AS WELL. WINDS CONTINUE TO BE LIGHT FROM THE EAST IN THIS AREA SO
THINK THAT WE WILL SEE THESE CONDITIONS CONTINUE THROUGH ABOUT
SUNRISE. WINDS WILL BE SWITCHING TO A WESTERLY DOWNSLOPE COMPONENT
BY THEN SO THE FOG SHOULD BE FAIRLY SHORT LIVED AFTER SUNRISE.
THE REST OF TODAY WILL BE A PLEASANT SPRINGLIKE DAY. A SHORTWAVE
RIDGE MOVES EAST OVER THE CENTRAL HIGH PLAINS WITH WARMER TEMPERATURES
IN THE LOWER TO MID LEVELS OF THE ATMOSPHERE ADVECTING BACK OUT OVER
WESTERN KANSAS. WITH AFTERNOON MIXING WE SHOULD SEE HIGHS CLIMBING
IN THE MID AND UPPER 70S. WINDS MAY GUST AS HIGH AS TO 10 TO 15 KNOTS
THROUGH MIDDAY BUT SHOULD BECOME FAIRLY LIGHT THROUGH THE AFTERNOON
HOURS.
TONIGHT THE SHORTWAVE RIDGE MOVES EAST OF THE AREA WITH THE MID
LEVEL FLOW BECOMING MORE SOUTHWESTERLY IN ADVANCE OF AN UPPER
TROUGH APPROACHING THE WEST COAST. WEAK LEE TROUGHING ALONG THE
EASTERN SLOPES WILL BRING WINDS BACK TO THE SOUTH. THE BOUNDARY
LAYER WILL REMAIN DRY SO WE SHOULD SEE CLEAR CONDITIONS OVERNIGHT.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 224 PM CDT MON MAR 12 2012
THE NAM, GFS AND ECMWF REMAINS CONSISTENT WITH PREVIOUS RUNS IN
PLACING A DRYLINE ACROSS PORTIONS OF SOUTHWEST KANSAS WEDNESDAY
AFTERNOON WITH OVER 1000J/KG OF CAPE FORECAST BY 00Z THURSDAY. THIS
INSTABILITY AND SURFACE BOUNDARY WILL BE LOCATED NEAR THE LEFT EXIT
REGION OF AN UPPER LEVEL JET SO GIVEN THIS WILL CONTINUE TO MENTION
A CHANCE OF LATE DAY/EVENING STORMS ACROSS SOUTH CENTRAL AND
PORTIONS OF SOUTHWEST KANSAS CLOSE TO THE OKLAHOMA BORDER. ALTHOUGH
THE EXACT LOCATION OF THE DRYLINE AND COLD FRONT IS STILL SOMEWHAT
UNCLEAR IT DOES APPEAR THAT THE MORE FAVORABLE LOCATION WILL BE NEAR
OR EAST OF A LIBERAL TO DODGE CITY TO NEAR GREAT BEND LINE. IT ALSO
APPEARS THE MAIN HAZARD FROM ANY STORM THAT MAY DEVELOP STILL BE
HAIL GIVEN THE MID LEVEL INSTABILITY, 0-6KM SHEAR AT OR BELOW
30KTS AND A WET BULB ZERO HEIGHT BETWEEN 1100-1300FT.
FOR THURSDAY AND FRIDAY THIS SURFACE BOUNDARY WILL MOVE VERY LITTLE
AND LATE DAY INSTABILITY BASED ON MIXED LAYER CAPES EACH EVENING
WILL RANGE FROM 1000 AND 1500J/KG. AS A RESULT UNABLE TO COMPLETELY
RULE OUT A LATE DAY STORM EITHER EVENING BUT BASED ON THE LATEST
TIMING OF A SUBTLE WAVE ROTATING ACROSS THE CENTRAL PLAINS LATE
FRIDAY WILL FOCUS THE BETTER OPPORTUNITY FOR CONVECTION FRIDAY
NIGHT.
AS FOR TEMPERATURES...THE PREVIOUS FORECAST STILL LOOKS ON TRACK
WITH ABOVE NORMAL TEMPERATURES PERSISTING INTO THE WEEKEND PERIOD
BASED ON THE 925-850MB TEMPERATURE TRENDS. ALSO WILL BE KEEPING LOWS
ABOVE GUIDANCE LATE WEEK AND OVER THE WEEKEND PERIOD BASED ON THE
EXPECTED RETURN OF LOW LEVEL MOISTURE ACROSS SOUTH CENTRAL AND MUCH
OF SOUTHWEST KANSAS.
LATE THIS WEEKEND THE NEXT SIGNIFICANT UPPER LEVEL SYSTEM WILL START
TO MOVE OUT OF THE EASTERN PACIFIC AND ONTO THE WEST COAST. THIS
UPPER LEVEL TROUGH IS EXPECTED TO DEEPEN EARLY NEXT WEEK AS IT
CROSSES THE SOUTHWEST UNITED STATES. MODELS TODAY CONTINUE TO
STRUGGLE WITH THE TRACK AND STRENGTH OF THIS NEXT SYSTEM EARLY WEEK
BUT IT DOES APPEAR A CHANCE FOR PRECIPITATION WILL RETURN BY LATE
MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1123 AM CDT MON MAR 12 2012
A DEEP DRY 12 UTC KDDC SOUNDING WAS OBSERVED WITH MODERATE WINDS
IN THE BOUNDARY LAYER. MOMENTUM TRANSFER WILL NOT BE IMPRESSIVE
THIS AFTERNOON AND WINDS ARE ANTICIPATED TO REMAIN AROUND 12 KNOTS
THROUGH THE AFTERNOON WITH MINIMAL GUSTS. SLIGHTLY STRONGER
SOUTHERLY WINDS ARE EXPECTED BY TUESDAY MORNING MAINLY DU8E TO A
BETTER SURFACE PRESSURE GRADIENT AND A BETTER 850 MB JET NOTED BY
MOS AND THE MESOSCALE MODEL. THE DRY LOWER AND MIDDLE LEVELS WILL
REMAIN IN PLACE THROUGH THE PERIOD ENSURING VFR CONDITIONS.
&&
.FIRE WEATHER...
ISSUED AT 1123 AM CDT MON MAR 12 2012
CONCERNS ARE INCREASING FOR CRITICAL FIRE WEATHER CRITERIA FARTHER
EAST THAN THE CURRENT WATCH HAD INDICATED. THIS MORNING`S VERY
DRY AND WARM BOUNDARY LAYER WITH +16 DEGREES AT 850 MB IN
ADDITION OT THE DRY AIR SHOULD CREATE A GREAT PRE EVENT
ENVIRONMENT FOR RAPIDLY FALLING RELATIVE HUMIDITIES WITH STRONG
MIXING ON TUESDAY. THE WINDS WOULD BE ASSUMED TO BE NEGLIGIBLE
ACCORDING TO THE GLOBAL MODELS, BUT MESOSCALE MODELS ARE
INDICATING 2 METER WINDS ABOVE 15 KNOTS WHICH SHOULD TRANSLATE INTO
FREQUENT GUSTS ABOVE 20 MPH EASILY. ADDITIONALLY THE MOS IS
ADVERTISING 20 KNOT WINDS AREA WIDE. WE WILL UPGRADE ALL WATCH
COUNTIES TO RED FLAG, AND ADD HODGEMAN, NESS AND TREGO COUNTIES
TO THE RED FLAG AS WELL. A BIT OF UNCERTAINTY EXISTS FARTHER EAST
AS MOISTURE ADVECTION COMES INTO PLAY WHICH MIGHT TEND TO NEGATE
THE LOWERING RH FARTHER SOUTHEAST. TO ACCOUNT FOR THIS, A WATCH
WILL BE ISSUED FOR MUCH OF THE REMAINDER OF OUR FORECAST AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 41 83 46 81 / 0 0 0 10
GCK 39 82 42 80 / 0 0 0 0
EHA 38 82 41 81 / 0 0 0 0
LBL 39 81 42 83 / 0 0 0 0
HYS 42 82 46 79 / 0 0 0 0
P28 44 81 53 81 / 0 0 0 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ TO 8 PM CDT /7 PM MDT/
TUESDAY FOR KSZ030-043>045-061>064-074>077-084>087.
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR KSZ031-046-065-066-078>080-088-089.
&&
$$
UPDATE...RUSSELL
SHORT TERM...GERARD
LONG TERM....BURGERT
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1145 AM CDT MON MAR 12 2012
...UPDATED FOR FIRE WEATHER AND AVIATION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 347 AM CDT MON MAR 12 2012
MAIN FORECAST CONCERN DURING THE SHORT TERM WILL BE AREAS OF DENSE
FOG OVER SOUTH CENTRAL KANSAS EARLY THIS MORNING. LOW CLOUD
ENHANCEMENT CHANNEL HAS BEEN SHOWING AREAS OF FOG WITH SOME PATCHY
DENSE FOG GENERALLY ALONG AND EAST OF HIGHWAY 183 SINCE BEFORE
MIDNIGHT. IN THE PAST HOUR THIS AREA HAS EXPANDED AND FILLED IN
CONSIDERABLY WITH AWOS OBS INDICATING A QUARTER MILE OR LESS AT
PRATT AND MEDICINE LODGE. HRRR VISIBILITY HAS BEEN HINTING AT THIS
AS WELL. WINDS CONTINUE TO BE LIGHT FROM THE EAST IN THIS AREA SO
THINK THAT WE WILL SEE THESE CONDITIONS CONTINUE THROUGH ABOUT
SUNRISE. WINDS WILL BE SWITCHING TO A WESTERLY DOWNSLOPE COMPONENT
BY THEN SO THE FOG SHOULD BE FAIRLY SHORT LIVED AFTER SUNRISE.
THE REST OF TODAY WILL BE A PLEASANT SPRINGLIKE DAY. A SHORTWAVE
RIDGE MOVES EAST OVER THE CENTRAL HIGH PLAINS WITH WARMER TEMPERATURES
IN THE LOWER TO MID LEVELS OF THE ATMOSPHERE ADVECTING BACK OUT OVER
WESTERN KANSAS. WITH AFTERNOON MIXING WE SHOULD SEE HIGHS CLIMBING
IN THE MID AND UPPER 70S. WINDS MAY GUST AS HIGH AS TO 10 TO 15 KNOTS
THROUGH MIDDAY BUT SHOULD BECOME FAIRLY LIGHT THROUGH THE AFTERNOON
HOURS.
TONIGHT THE SHORTWAVE RIDGE MOVES EAST OF THE AREA WITH THE MID
LEVEL FLOW BECOMING MORE SOUTHWESTERLY IN ADVANCE OF AN UPPER
TROUGH APPROACHING THE WEST COAST. WEAK LEE TROUGHING ALONG THE
EASTERN SLOPES WILL BRING WINDS BACK TO THE SOUTH. THE BOUNDARY
LAYER WILL REMAIN DRY SO WE SHOULD SEE CLEAR CONDITIONS OVERNIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 358 AM CDT MON MAR 12 2012
UPPER-LEVEL TROUGHING WILL PERSIST THROUGH MARCH 18TH ACROSS THE FAR
WESTERN UNITED STATES, THEN SLOWLY PROGRESS EASTWARD AND AMPLIFY
JUST TO OUR WEST BY MARCH 19-20TH. GIVEN THE EXPECTED POSITIONING OF
THIS TROUGH OVER THE FAR WESTERN UNITED STATES BY MID-WEEK,
SOUTHWESTERLY MID-LEVEL FLOW WILL BE PRESENT ACROSS THE ROCKIES AND
OVER THE PLAINS. LEE TROUGHING WILL DEVELOP IN RESPONSE TO THE FLOW
ACROSS THE ROCKIES, AND THIS WILL SERVE TO DRAW RICH LOW-LEVEL
MOISTURE NORTHWARD INTO THE SOUTHERN PLAINS. THE SURFACE DRYLINE
WILL MARK THE INTERFACE BETWEEN THE MOIST AIRMASS OVER THE PLAINS
AND THE DRY AIRMASS OVER THE WESTERN HIGH PLAINS AND ROCKIES. IT
WILL BE WARM EVERY DAY THROUGH THE WEEKEND WITH HIGHS IN THE 70S AND
80S AND LOWS FROM THE UPPER 40S WEST TO 55 TO 62 IN SOUTH CENTRAL
KANSAS. OFTENTIMES IN RETURN FLOW SITUATIONS IN MARCH, PREVIOUS COLD
FRONTAL PASSAGES THROUGH THE GULF AND EVEN INTO THE CARIBBEAN RESULT
IN ONLY MODEST MOISTURE RETURNS INTO THE PLAINS. THIS WILL NOT BE
THE CASE THIS WEEK SINCE THE GULF SEA SURFACE IS NEARLY AT
EQUILIBRIUM WITH THE AIR IMMEDIATELY ABOVE. GULF BUOY DATA INDICATE
DEWPOINTS AROUND 70F IN THE CENTRAL GULF CURRENTLY, WHICH IS VERY
IMPRESSIVE FOR THIS TIME OF YEAR. KEEP IN MIND THAT JUST BECAUSE 70F
DEWPOINTS ARE PRESENT IN THE CENTRAL GULF DOESN`T MEAN THAT WE CAN
EXPECT DEWPOINTS THAT HIGH IN SOUTHWEST KANSAS LATER THIS WEEK.
WHEN MOIST, MARINE AIR MOVES NORTHWARD INTO THE PLAINS, DEEP
VERTICAL MIXING OCCURS, WHICH CAUSES THE MOIST LAYER TO BE DEEPER,
BUT NOT QUITE AS RICH. ALSO, DODGE CITY IS 2600FT ABOVE SEA LEVEL
AND THIS INCREASED ELEVATION WILL RESULT IN SOME REDUCTION IN
DEWPOINT AS WELL AS THE MOISTURE MOVES ONTO THE HIGHER TERRAIN. SO
IT IS MORE REASONABLE TO EXPECT DEWPOINT TEMPERATURES FROM THE MID
50S TO THE MID 60S (13-18C) AHEAD OF THE DRYLINE.
BY WEDNESDAY AFTERNOON, THE SURFACE DRYLINE WILL STRETCH FROM A
WEAK SURFACE LOW AND FRONT OVER SOUTHWEST KANSAS SOUTH-SOUTHWESTWARD
INTO THE TEXAS PANHANDLE. A SUBTROPICAL JET STREAK WILL BE SITUATED
ACROSS THE TEXAS PANHANDLE. SURFACE BASED CAPE VALUES WILL APPROACH
2000 J/KG BY LATE AFTERNOON FROM DODGE CITY SOUTH AND EAST. THERE
MAY BE ENOUGH CONVERGENCE ALONG THE DRYLINE AND NEAR THE FRONT-
DRYLINE INTERSECTION, ALONG WITH STRONG ELEVATED HEATING, TO YIELD
ISOLATED THUNDERSTORMS. ANY STORMS THAT DEVELOP COULD BE SEVERE WITH
LARGE HAIL.
ISOLATED THUNDERSTORMS CANNOT BE RULED ANY DAY THROUGH MARCH 20TH AS THE
SURFACE DRYLINE REMAINS OVER WESTERN KANSAS. THE ECMWF INDICATES
THAT THE BEST CHANCES MAY BE SATURDAY FROM DODGE CITY SOUTHEASTWARD,
AND THEN AGAIN BY MONDAY AND TUESDAY AS THE UPPER-LEVEL TROUGH AND
ASSOCIATED MID-LEVEL COOLING APPROACH WESTERN KANSAS. ANY STORMS
THAT DEVELOP IN THESE PERIODS COULD BE SEVERE, ALTHOUGH THE BEST
CHANCE OF HIGH-END SEVERE STORMS WITH TORNADOES SHOULD BE LATER
MONDAY OR TUESDAY AS THE MID TO HIGH-LEVEL WINDS BECOME MUCH
STRONGER IN ADVANCE OF THE UPPER-LEVEL TROUGH. OF COURSE, A LOT
COULD CHANGE BETWEEN NOW AND MARCH 19TH-20TH; AND IT IS IMPOSSIBLE
TO SAY AT THIS POINT EXACTLY WHERE IN THE PLAINS THE BEST CHANCE
OF THUNDERSTORMS WILL BE.
KEEP IN MIND THAT DUE TO THE VERY WARM EXPECTED TEMPERATURES, RECORD
HIGH NIGHTTIME AND DAYTIME TEMPERATURES ARE POSSIBLE ACROSS WESTERN
KANSAS LATER THIS WEEK AND THIS WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1123 AM CDT MON MAR 12 2012
A DEEP DRY 12 UTC KDDC SOUNDING WAS OBSERVED WITH MODERATE WINDS
IN THE BOUNDARY LAYER. MOMENTUM TRANSFER WILL NOT BE IMPRESSIVE
THIS AFTERNOON AND WINDS ARE ANTICIPATED TO REMAIN AROUND 12 KNOTS
THROUGH THE AFTERNOON WITH MINIMAL GUSTS. SLIGHTLY STRONGER
SOUTHERLY WINDS ARE EXPECTED BY TUESDAY MORNING MAINLY DU8E TO A
BETTER SURFACE PRESSURE GRADIENT AND A BETTER 850 MB JET NOTED BY
MOS AND THE MESOSCALE MODEL. THE DRY LOWER AND MIDDLE LEVELS WILL
REMAIN IN PLACE THROUGH THE PERIOD ENSURING VFR CONDITIONS.
&&
.FIRE WEATHER...
ISSUED AT 1123 AM CDT MON MAR 12 2012
CONCERNS ARE INCREASING FOR CRITICAL FIRE WEATHER CRITERIA FARTHER
EAST THAN THE CURRENT WATCH HAD INDICATED. THIS MORNING`S VERY
DRY AND WARM BOUNDARY LAYER WITH +16 DEGREES AT 850 MB IN
ADDITION OT THE DRY AIR SHOULD CREATE A GREAT PRE EVENT
ENVIRONMENT FOR RAPIDLY FALLING RELATIVE HUMIDITIES WITH STRONG
MIXING ON TUESDAY. THE WINDS WOULD BE ASSUMED TO BE NEGLIGIBLE
ACCORDING TO THE GLOBAL MODELS, BUT MESOSCALE MODELS ARE
INDICATING 2 METER WINDS ABOVE 15 KNOTS WHICH SHOULD TRANSLATE INTO
FREQUENT GUSTS ABOVE 20 MPH EASILY. ADDITIONALLY THE MOS IS
ADVERTISING 20 KNOT WINDS AREA WIDE. WE WILL UPGRADE ALL WATCH
COUNTIES TO RED FLAG, AND ADD HODGEMAN, NESS AND TREGO COUNTIES
TO THE RED FLAG AS WELL. A BIT OF UNCERTAINTY EXISTS FARTHER EAST
AS MOISTURE ADVECTION COMES INTO PLAY WHICH MIGHT TEND TO NEGATE
THE LOWERING RH FARTHER SOUTHEAST. TO ACCOUNT FOR THIS, A WATCH
WILL BE ISSUED FOR MUCH OF THE REMAINDER OF OUR FORECAST AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 77 41 83 46 / 0 0 0 0
GCK 76 39 82 42 / 0 0 0 0
EHA 75 38 82 41 / 0 0 0 0
LBL 76 39 81 42 / 0 0 0 0
HYS 78 42 82 46 / 0 0 0 0
P28 78 44 81 53 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR KSZ043-044-061>063-074>077-084>087.
&&
$$
UPDATE...RUSSELL
SHORT TERM...GERARD
LONG TERM....FINCH
AVIATION...99
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
926 AM CDT MON MAR 12 2012
...UPDATE TO REMOVE DENSE FOG...
.UPDATE...
ISSUED AT 920 AM CDT MON MAR 12 2012
THE 11-3.9 MICRON SATELLITE IMAGERY AS WELL AS LOCAL METAR
OBSERVATIONS INDICATED THAT THE DENSE FOG ACROSS THE FAR
SOUTHEAST COUNTIES HAD DISSIPATED RAPIDLY THIS MORNING. THE DENSE
FOG ADVISORY WAS CANCELED EARLY. NO OTHER IMMEDIATE SHORT TERM
CHANGES ARE ANTICIPATED AS FIRE WEATHER ISSUES FOR TUESDAY ARE
BEING EVALUATED.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 347 AM CDT MON MAR 12 2012
MAIN FORECAST CONCERN DURING THE SHORT TERM WILL BE AREAS OF DENSE
FOG OVER SOUTH CENTRAL KANSAS EARLY THIS MORNING. LOW CLOUD
ENHANCEMENT CHANNEL HAS BEEN SHOWING AREAS OF FOG WITH SOME PATCHY
DENSE FOG GENERALLY ALONG AND EAST OF HIGHWAY 183 SINCE BEFORE
MIDNIGHT. IN THE PAST HOUR THIS AREA HAS EXPANDED AND FILLED IN
CONSIDERABLY WITH AWOS OBS INDICATING A QUARTER MILE OR LESS AT
PRATT AND MEDICINE LODGE. HRRR VISIBILITY HAS BEEN HINTING AT THIS
AS WELL. WINDS CONTINUE TO BE LIGHT FROM THE EAST IN THIS AREA SO
THINK THAT WE WILL SEE THESE CONDITIONS CONTINUE THROUGH ABOUT
SUNRISE. WINDS WILL BE SWITCHING TO A WESTERLY DOWNSLOPE COMPONENT
BY THEN SO THE FOG SHOULD BE FAIRLY SHORT LIVED AFTER SUNRISE.
THE REST OF TODAY WILL BE A PLEASANT SPRINGLIKE DAY. A SHORTWAVE
RIDGE MOVES EAST OVER THE CENTRAL HIGH PLAINS WITH WARMER TEMPERATURES
IN THE LOWER TO MID LEVELS OF THE ATMOSPHERE ADVECTING BACK OUT OVER
WESTERN KANSAS. WITH AFTERNOON MIXING WE SHOULD SEE HIGHS CLIMBING
IN THE MID AND UPPER 70S. WINDS MAY GUST AS HIGH AS TO 10 TO 15 KNOTS
THROUGH MIDDAY BUT SHOULD BECOME FAIRLY LIGHT THROUGH THE AFTERNOON
HOURS.
TONIGHT THE SHORTWAVE RIDGE MOVES EAST OF THE AREA WITH THE MID
LEVEL FLOW BECOMING MORE SOUTHWESTERLY IN ADVANCE OF AN UPPER
TROUGH APPROACHING THE WEST COAST. WEAK LEE TROUGHING ALONG THE
EASTERN SLOPES WILL BRING WINDS BACK TO THE SOUTH. THE BOUNDARY
LAYER WILL REMAIN DRY SO WE SHOULD SEE CLEAR CONDITIONS OVERNIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 358 AM CDT MON MAR 12 2012
UPPER-LEVEL TROUGHING WILL PERSIST THROUGH MARCH 18TH ACROSS THE FAR
WESTERN UNITED STATES, THEN SLOWLY PROGRESS EASTWARD AND AMPLIFY
JUST TO OUR WEST BY MARCH 19-20TH. GIVEN THE EXPECTED POSITIONING OF
THIS TROUGH OVER THE FAR WESTERN UNITED STATES BY MID-WEEK,
SOUTHWESTERLY MID-LEVEL FLOW WILL BE PRESENT ACROSS THE ROCKIES AND
OVER THE PLAINS. LEE TROUGHING WILL DEVELOP IN RESPONSE TO THE FLOW
ACROSS THE ROCKIES, AND THIS WILL SERVE TO DRAW RICH LOW-LEVEL
MOISTURE NORTHWARD INTO THE SOUTHERN PLAINS. THE SURFACE DRYLINE
WILL MARK THE INTERFACE BETWEEN THE MOIST AIRMASS OVER THE PLAINS
AND THE DRY AIRMASS OVER THE WESTERN HIGH PLAINS AND ROCKIES. IT
WILL BE WARM EVERY DAY THROUGH THE WEEKEND WITH HIGHS IN THE 70S AND
80S AND LOWS FROM THE UPPER 40S WEST TO 55 TO 62 IN SOUTH CENTRAL
KANSAS. OFTENTIMES IN RETURN FLOW SITUATIONS IN MARCH, PREVIOUS COLD
FRONTAL PASSAGES THROUGH THE GULF AND EVEN INTO THE CARIBBEAN RESULT
IN ONLY MODEST MOISTURE RETURNS INTO THE PLAINS. THIS WILL NOT BE
THE CASE THIS WEEK SINCE THE GULF SEA SURFACE IS NEARLY AT
EQUILIBRIUM WITH THE AIR IMMEDIATELY ABOVE. GULF BUOY DATA INDICATE
DEWPOINTS AROUND 70F IN THE CENTRAL GULF CURRENTLY, WHICH IS VERY
IMPRESSIVE FOR THIS TIME OF YEAR. KEEP IN MIND THAT JUST BECAUSE 70F
DEWPOINTS ARE PRESENT IN THE CENTRAL GULF DOESN`T MEAN THAT WE CAN
EXPECT DEWPOINTS THAT HIGH IN SOUTHWEST KANSAS LATER THIS WEEK.
WHEN MOIST, MARINE AIR MOVES NORTHWARD INTO THE PLAINS, DEEP
VERTICAL MIXING OCCURS, WHICH CAUSES THE MOIST LAYER TO BE DEEPER,
BUT NOT QUITE AS RICH. ALSO, DODGE CITY IS 2600FT ABOVE SEA LEVEL
AND THIS INCREASED ELEVATION WILL RESULT IN SOME REDUCTION IN
DEWPOINT AS WELL AS THE MOISTURE MOVES ONTO THE HIGHER TERRAIN. SO
IT IS MORE REASONABLE TO EXPECT DEWPOINT TEMPERATURES FROM THE MID
50S TO THE MID 60S (13-18C) AHEAD OF THE DRYLINE.
BY WEDNESDAY AFTERNOON, THE SURFACE DRYLINE WILL STRETCH FROM A
WEAK SURFACE LOW AND FRONT OVER SOUTHWEST KANSAS SOUTH-SOUTHWESTWARD
INTO THE TEXAS PANHANDLE. A SUBTROPICAL JET STREAK WILL BE SITUATED
ACROSS THE TEXAS PANHANDLE. SURFACE BASED CAPE VALUES WILL APPROACH
2000 J/KG BY LATE AFTERNOON FROM DODGE CITY SOUTH AND EAST. THERE
MAY BE ENOUGH CONVERGENCE ALONG THE DRYLINE AND NEAR THE FRONT-
DRYLINE INTERSECTION, ALONG WITH STRONG ELEVATED HEATING, TO YIELD
ISOLATED THUNDERSTORMS. ANY STORMS THAT DEVELOP COULD BE SEVERE WITH
LARGE HAIL.
ISOLATED THUNDERSTORMS CANNOT BE RULED ANY DAY THROUGH MARCH 20TH AS THE
SURFACE DRYLINE REMAINS OVER WESTERN KANSAS. THE ECMWF INDICATES
THAT THE BEST CHANCES MAY BE SATURDAY FROM DODGE CITY SOUTHEASTWARD,
AND THEN AGAIN BY MONDAY AND TUESDAY AS THE UPPER-LEVEL TROUGH AND
ASSOCIATED MID-LEVEL COOLING APPROACH WESTERN KANSAS. ANY STORMS
THAT DEVELOP IN THESE PERIODS COULD BE SEVERE, ALTHOUGH THE BEST
CHANCE OF HIGH-END SEVERE STORMS WITH TORNADOES SHOULD BE LATER
MONDAY OR TUESDAY AS THE MID TO HIGH-LEVEL WINDS BECOME MUCH
STRONGER IN ADVANCE OF THE UPPER-LEVEL TROUGH. OF COURSE, A LOT
COULD CHANGE BETWEEN NOW AND MARCH 19TH-20TH; AND IT IS IMPOSSIBLE
TO SAY AT THIS POINT EXACTLY WHERE IN THE PLAINS THE BEST CHANCE
OF THUNDERSTORMS WILL BE.
KEEP IN MIND THAT DUE TO THE VERY WARM EXPECTED TEMPERATURES, RECORD
HIGH NIGHTTIME AND DAYTIME TEMPERATURES ARE POSSIBLE ACROSS WESTERN
KANSAS LATER THIS WEEK AND THIS WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 600 AM CDT MON MAR 12 2012
VFR CONDITIONS WILL PREVAIL. A WEAK TROUGH OF LOW PRESSURE WILL BE SITUATED
THROUGH THE CENTRAL PLAINS TODAY. WINDS WILL SHIFT TO THE NORTHWEST
BEHIND THIS TROUGH BY MIDDAY. THE PRESSURE GRADIENT WILL WEAKEN BY
LATE AFTERNOON RESULTING IN LIGHT WINDS BY THIS EVENING.
&&
.FIRE WEATHER...
ISSUED AT 402 AM CDT MON MAR 12 2012
FIRE WEATHER WILL BE A CONCERN ON TUESDAY. AFTERNOON VERTICAL
MIXING WILL RESULT IN RELATIVE HUMIDITIES FROM 10 TO 15 PERCENT
ALONG WITH FREQUENT WIND GUSTS NEAR OR JUST IN EXCESS OF 25 MPH.
A FIRE WEATHER WATCH IS IN EFFECT ALONG AND WEST OF A LINE FROM
MEADE TO DIGHTON. THIS WAS NOT UPGRADED SINCE THERE IS SOME
QUESTION AS TO WHETHER SURFACE WINDS WILL BE STRONG ENOUGH. ALSO
ELLIS AND TREGO COUNTIES MAY NEED TO BE ADDED.
AFTER A LESSENING OF THE PRESSURE GRADIENT WEDNESDAY AND THURSDAY,
FIRE WEATHER WILL BE A CONCERN EVERY DAY FROM FRIDAY THROUGH SUNDAY,
ESPECIALLY IN FAR WESTERN KANSAS BEHIND THE SURFACE DRYLINE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 77 41 83 46 / 0 0 0 0
GCK 76 39 82 42 / 0 0 0 0
EHA 75 38 82 41 / 0 0 0 0
LBL 76 39 81 42 / 0 0 0 0
HYS 78 42 82 46 / 0 0 0 0
P28 78 44 81 53 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR KSZ043-044-061>063-074>077-084>087.
&&
$$
UPDATE...RUSSELL
SHORT TERM...GERARD
LONG TERM....FINCH
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS TOPEKA KS
621 AM CDT MON MAR 12 2012
...AVIATION UPDATE...
.DISCUSSION...
SEE PREV DISCUSSION.
&&
.AVIATION...
LATEST RUC AND NAM FORECAST SOUNDINGS SHOW THE BOUNDARY LAYER
REMAINING CAPPED WITH LOW LEVEL MOISTURE TRAPPED THROUGH ABOUT
16Z. WITH SATELLITE SHOWING A BROAD AREA OF STRATUS...WILL HANG
ONTO MVFR CIGS FOR TOP AND FOE A LITTLE LONGER THAN PREV FORECAST.
THERE ARE ACTUALLY SOME IFR AND LIFR CIGS JUST WEST OF MHK WHICH
COULD MOVE IN. THINK THE CLEAR SKIES CURRENTLY BEING REPORTED WILL
BE TEMPORARY UNTIL THE BOUNDARY LAYER MIXES OUT AROUND 16Z. ONCE
THE LOW LEVEL MOISTURE IS SCOURED OUT...LARGE SCALE SUBSIDENCE
SHOULD LEAD TO VFR CONDITIONS.
WOLTERS
&&
.FIRE WEATHER... /ISSUED 335 AM CDT MON MAR 12 2012/
TODAY WITH THE WARM AFTERNOON TEMPERATURES AND DEWPOINTS IN THE
MIDDLE 30S TO NEAR 40...THE RANGELAND FIRE DANGER INDEX WILL REACH
THE VERY HIGH CATEGORY FOR MUCH OF THE AREA. OF GREATEST CONCERN
WILL BE NORTH CENTRAL KANSAS...WITH MINIMUM RELATIVE HUMIDITY
VALUES IN THE 22 TO 26 PERCENT RANGE. THE PRESSURE GRADIENT
RELAXES BY EARLY AFTERNOON...WITH WIND SPEEDS DECREASING DURING
THE AFTERNOON HOURS. ADDITIONALLY...MANY LOCATIONS RECEIVED
PRECIPITATION ON SUNDAY. THESE MITIGATING FACTORS MAY HELP KEEP
FIRE WEATHER ISSUES SOMEWHAT IN CHECK. ON TUESDAY...A GRADUAL
INCREASE IN LOW LEVEL MOISTURE SHOULD KEEP CONDITIONS BELOW RED
FLAG CRITERIA...EVEN WITH SURFACE TEMPERATURES NEARING 80 DEGREES.
BLAIR
&&
.PREV DISCUSSION... /ISSUED 335 AM CDT MON MAR 12 2012/
TODAY/TONIGHT...CENTER OF UPPER LOW CURRENTLY LOCATED OVER
SOUTHEAST NEBRASKA WILL CONTINUE ITS QUICK NORTHEASTWARD EXIT FROM
THE AREA THIS MORNING. THE LAST REMAINING PRECIPITATION AREA
REMAINS IN A FRONTOGENETICAL REGION OVER NORTH CENTRAL KANSAS.
WITH ITS CURRENT TRAJECTORY AND SOME WEAKENING ON THE SOUTHERN
END...HAVE INTRODUCED A SLIGHT CHANCE OF SHOWERS TO CONTINUE FROM
12Z THROUGH 15Z OVER THE FAR NORTHEASTERN CWA. ALL PRECIPITATION
WILL END ACROSS THE CWA BY 15Z...WITH RAPIDLY CLEARING SKIES FROM
SOUTHWEST TO NORTHEAST. TEMPERATURES WILL QUICKLY INCREASE BY
MID/LATE MORNING BEHIND THE DEPARTING SYSTEM...WITH READINGS
REACHING THE LOWER TO MIDDLE 70S DURING THE AFTERNOON. WINDS WILL
BECOME LIGHT TONIGHT WITH LITTLE INCREASE IN LOW LEVEL MOISTURE
OVERNIGHT. LOWS WILL FALL INTO THE MIDDLE 40S IN MOST LOCATIONS.
SEE FIRE WEATHER DISCUSSION BELOW FOR ADDITIONAL FORECAST DETAILS
FOR TODAY.
TUESDAY THROUGH SUNDAY...RELATIVELY PERSISTENT PATTERN EXPECTED OVER
THE PERIOD WITH THE UPPER JET RETREATING NORTHWARD AS UPPER RIDGING
DOMINATES THE CENTRAL CONUS. WEAK TO MODERATE SOUTHWEST FLOW ALOFT
WILL SPREAD OVER THE CENTRAL PLAINS...WITH OPERATIONAL MODELS
SUGGESTING OCCASIONAL WEAK DISTURBANCES TRAVERSING THE AREA. AT THE
SURFACE...A DRYLINE WILL RESIDE OVER OR JUST WEST OF THE CWA THROUGH
THE PERIOD...PLACING THE FORECAST AREA IN A WARM...MOIST AND
UNSTABLE AIRMASS. SLIGHT CHANCES OF THUNDERSTORMS WILL BE POSSIBLE
EACH DAY...WITH SPECIFIC TIMING BETTER RESOLVED AS UPPER FEATURES
AND MESOSCALE PROCESSES BECOME IDENTIFIED. TEMPERATURES WILL BE WELL
ABOVE NORMAL...CLOSER TO READINGS FOR EARLY/MID MAY...WITH HIGHS IN
THE MIDDLE 70S TO LOWER 80S. WITH DEWPOINTS INCREASING TO THE MIDDLE
50S TO LOWER 60S...LOWS WILL ONLY FALL INTO THE 50S EACH NIGHT.
BLAIR
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
603 AM CDT MON MAR 12 2012
...UPDATED FOR AVIATION DISCUSSION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 347 AM CDT MON MAR 12 2012
MAIN FORECAST CONCERN DURING THE SHORT TERM WILL BE AREAS OF DENSE
FOG OVER SOUTH CENTRAL KANSAS EARLY THIS MORNING. LOW CLOUD
ENHANCEMENT CHANNEL HAS BEEN SHOWING AREAS OF FOG WITH SOME PATCHY
DENSE FOG GENERALLY ALONG AND EAST OF HIGHWAY 183 SINCE BEFORE
MIDNIGHT. IN THE PAST HOUR THIS AREA HAS EXPANDED AND FILLED IN
CONSIDERABLY WITH AWOS OBS INDICATING A QUARTER MILE OR LESS AT
PRATT AND MEDICINE LODGE. HRRR VISIBILITY HAS BEEN HINTING AT THIS
AS WELL. WINDS CONTINUE TO BE LIGHT FROM THE EAST IN THIS AREA SO
THINK THAT WE WILL SEE THESE CONDITIONS CONTINUE THROUGH ABOUT
SUNRISE. WINDS WILL BE SWITCHING TO A WESTERLY DOWNSLOPE COMPONENT
BY THEN SO THE FOG SHOULD BE FAIRLY SHORT LIVED AFTER SUNRISE.
THE REST OF TODAY WILL BE A PLEASANT SPRINGLIKE DAY. A SHORTWAVE
RIDGE MOVES EAST OVER THE CENTRAL HIGH PLAINS WITH WARMER TEMPERATURES
IN THE LOWER TO MID LEVELS OF THE ATMOSPHERE ADVECTING BACK OUT OVER
WESTERN KANSAS. WITH AFTERNOON MIXING WE SHOULD SEE HIGHS CLIMBING
IN THE MID AND UPPER 70S. WINDS MAY GUST AS HIGH AS TO 10 TO 15 KNOTS
THROUGH MIDDAY BUT SHOULD BECOME FAIRLY LIGHT THROUGH THE AFTERNOON
HOURS.
TONIGHT THE SHORTWAVE RIDGE MOVES EAST OF THE AREA WITH THE MID
LEVEL FLOW BECOMING MORE SOUTHWESTERLY IN ADVANCE OF AN UPPER
TROUGH APPROACHING THE WEST COAST. WEAK LEE TROUGHING ALONG THE
EASTERN SLOPES WILL BRING WINDS BACK TO THE SOUTH. THE BOUNDARY
LAYER WILL REMAIN DRY SO WE SHOULD SEE CLEAR CONDITIONS OVERNIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 358 AM CDT MON MAR 12 2012
UPPER-LEVEL TROUGHING WILL PERSIST THROUGH MARCH 18TH ACROSS THE FAR
WESTERN UNITED STATES, THEN SLOWLY PROGRESS EASTWARD AND AMPLIFY
JUST TO OUR WEST BY MARCH 19-20TH. GIVEN THE EXPECTED POSITIONING OF
THIS TROUGH OVER THE FAR WESTERN UNITED STATES BY MID-WEEK,
SOUTHWESTERLY MID-LEVEL FLOW WILL BE PRESENT ACROSS THE ROCKIES AND
OVER THE PLAINS. LEE TROUGHING WILL DEVELOP IN RESPONSE TO THE FLOW
ACROSS THE ROCKIES, AND THIS WILL SERVE TO DRAW RICH LOW-LEVEL
MOISTURE NORTHWARD INTO THE SOUTHERN PLAINS. THE SURFACE DRYLINE
WILL MARK THE INTERFACE BETWEEN THE MOIST AIRMASS OVER THE PLAINS
AND THE DRY AIRMASS OVER THE WESTERN HIGH PLAINS AND ROCKIES. IT
WILL BE WARM EVERY DAY THROUGH THE WEEKEND WITH HIGHS IN THE 70S AND
80S AND LOWS FROM THE UPPER 40S WEST TO 55 TO 62 IN SOUTH CENTRAL
KANSAS. OFTENTIMES IN RETURN FLOW SITUATIONS IN MARCH, PREVIOUS COLD
FRONTAL PASSAGES THROUGH THE GULF AND EVEN INTO THE CARIBBEAN RESULT
IN ONLY MODEST MOISTURE RETURNS INTO THE PLAINS. THIS WILL NOT BE
THE CASE THIS WEEK SINCE THE GULF SEA SURFACE IS NEARLY AT
EQUILIBRIUM WITH THE AIR IMMEDIATELY ABOVE. GULF BUOY DATA INDICATE
DEWPOINTS AROUND 70F IN THE CENTRAL GULF CURRENTLY, WHICH IS VERY
IMPRESSIVE FOR THIS TIME OF YEAR. KEEP IN MIND THAT JUST BECAUSE 70F
DEWPOINTS ARE PRESENT IN THE CENTRAL GULF DOESN`T MEAN THAT WE CAN
EXPECT DEWPOINTS THAT HIGH IN SOUTHWEST KANSAS LATER THIS WEEK.
WHEN MOIST, MARINE AIR MOVES NORTHWARD INTO THE PLAINS, DEEP
VERTICAL MIXING OCCURS, WHICH CAUSES THE MOIST LAYER TO BE DEEPER,
BUT NOT QUITE AS RICH. ALSO, DODGE CITY IS 2600FT ABOVE SEA LEVEL
AND THIS INCREASED ELEVATION WILL RESULT IN SOME REDUCTION IN
DEWPOINT AS WELL AS THE MOISTURE MOVES ONTO THE HIGHER TERRAIN. SO
IT IS MORE REASONABLE TO EXPECT DEWPOINT TEMPERATURES FROM THE MID
50S TO THE MID 60S (13-18C) AHEAD OF THE DRYLINE.
BY WEDNESDAY AFTERNOON, THE SURFACE DRYLINE WILL STRETCH FROM A
WEAK SURFACE LOW AND FRONT OVER SOUTHWEST KANSAS SOUTH-SOUTHWESTWARD
INTO THE TEXAS PANHANDLE. A SUBTROPICAL JET STREAK WILL BE SITUATED
ACROSS THE TEXAS PANHANDLE. SURFACE BASED CAPE VALUES WILL APPROACH
2000 J/KG BY LATE AFTERNOON FROM DODGE CITY SOUTH AND EAST. THERE
MAY BE ENOUGH CONVERGENCE ALONG THE DRYLINE AND NEAR THE FRONT-
DRYLINE INTERSECTION, ALONG WITH STRONG ELEVATED HEATING, TO YIELD
ISOLATED THUNDERSTORMS. ANY STORMS THAT DEVELOP COULD BE SEVERE WITH
LARGE HAIL.
ISOLATED THUNDERSTORMS CANNOT BE RULED ANY DAY THROUGH MARCH 20TH AS THE
SURFACE DRYLINE REMAINS OVER WESTERN KANSAS. THE ECMWF INDICATES
THAT THE BEST CHANCES MAY BE SATURDAY FROM DODGE CITY SOUTHEASTWARD,
AND THEN AGAIN BY MONDAY AND TUESDAY AS THE UPPER-LEVEL TROUGH AND
ASSOCIATED MID-LEVEL COOLING APPROACH WESTERN KANSAS. ANY STORMS
THAT DEVELOP IN THESE PERIODS COULD BE SEVERE, ALTHOUGH THE BEST
CHANCE OF HIGH-END SEVERE STORMS WITH TORNADOES SHOULD BE LATER
MONDAY OR TUESDAY AS THE MID TO HIGH-LEVEL WINDS BECOME MUCH
STRONGER IN ADVANCE OF THE UPPER-LEVEL TROUGH. OF COURSE, A LOT
COULD CHANGE BETWEEN NOW AND MARCH 19TH-20TH; AND IT IS IMPOSSIBLE
TO SAY AT THIS POINT EXACTLY WHERE IN THE PLAINS THE BEST CHANCE
OF THUNDERSTORMS WILL BE.
KEEP IN MIND THAT DUE TO THE VERY WARM EXPECTED TEMPERATURES, RECORD
HIGH NIGHTTIME AND DAYTIME TEMPERATURES ARE POSSIBLE ACROSS WESTERN
KANSAS LATER THIS WEEK AND THIS WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 600 AM CDT MON MAR 12 2012
VFR CONDITIONS WILL PREVAIL. A WEAK TROUGH OF LOW PRESSURE WILL BE SITUATED
THROUGH THE CENTRAL PLAINS TODAY. WINDS WILL SHIFT TO THE NORTHWEST
BEHIND THIS TROUGH BY MIDDAY. THE PRESSURE GRADIENT WILL WEAKEN BY
LATE AFTERNOON RESULTING IN LIGHT WINDS BY THIS EVENING.
&&
.FIRE WEATHER...
ISSUED AT 402 AM CDT MON MAR 12 2012
FIRE WEATHER WILL BE A CONCERN ON TUESDAY. AFTERNOON VERTICAL
MIXING WILL RESULT IN RELATIVE HUMIDITIES FROM 10 TO 15 PERCENT
ALONG WITH FREQUENT WIND GUSTS NEAR OR JUST IN EXCESS OF 25 MPH.
A FIRE WEATHER WATCH IS IN EFFECT ALONG AND WEST OF A LINE FROM
MEADE TO DIGHTON. THIS WAS NOT UPGRADED SINCE THERE IS SOME
QUESTION AS TO WHETHER SURFACE WINDS WILL BE STRONG ENOUGH. ALSO
ELLIS AND TREGO COUNTIES MAY NEED TO BE ADDED.
AFTER A LESSENING OF THE PRESSURE GRADIENT WEDNESDAY AND THURSDAY,
FIRE WEATHER WILL BE A CONCERN EVERY DAY FROM FRIDAY THROUGH SUNDAY,
ESPECIALLY IN FAR WESTERN KANSAS BEHIND THE SURFACE DRYLINE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 77 41 83 46 / 0 0 0 0
GCK 76 39 82 42 / 0 0 0 0
EHA 75 38 82 41 / 0 0 0 0
LBL 76 39 81 42 / 0 0 0 0
HYS 78 42 82 46 / 0 0 0 0
P28 78 44 81 53 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR KSZ043-044-061>063-074>077-084>087.
DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR KSZ065-066-
079>081-089-090.
&&
$$
UPDATE...BURKE
SHORT TERM...GERARD
LONG TERM....FINCH
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
410 AM CDT MON MAR 12 2012
...UPDATED FOR FIRE WEATHER DISCUSSION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 347 AM CDT MON MAR 12 2012
MAIN FORECAST CONCERN DURING THE SHORT TERM WILL BE AREAS OF DENSE
FOG OVER SOUTH CENTRAL KANSAS EARLY THIS MORNING. LOW CLOUD
ENHANCEMENT CHANNEL HAS BEEN SHOWING AREAS OF FOG WITH SOME PATCHY
DENSE FOG GENERALLY ALONG AND EAST OF HIGHWAY 183 SINCE BEFORE
MIDNIGHT. IN THE PAST HOUR THIS AREA HAS EXPANDED AND FILLED IN
CONSIDERABLY WITH AWOS OBS INDICATING A QUARTER MILE OR LESS AT
PRATT AND MEDICINE LODGE. HRRR VISIBILITY HAS BEEN HINTING AT THIS
AS WELL. WINDS CONTINUE TO BE LIGHT FROM THE EAST IN THIS AREA SO
THINK THAT WE WILL SEE THESE CONDITIONS CONTINUE THROUGH ABOUT
SUNRISE. WINDS WILL BE SWITCHING TO A WESTERLY DOWNSLOPE COMPONENT
BY THEN SO THE FOG SHOULD BE FAIRLY SHORT LIVED AFTER SUNRISE.
THE REST OF TODAY WILL BE A PLEASANT SPRINGLIKE DAY. A SHORTWAVE
RIDGE MOVES EAST OVER THE CENTRAL HIGH PLAINS WITH WARMER TEMPERATURES
IN THE LOWER TO MID LEVELS OF THE ATMOSPHERE ADVECTING BACK OUT OVER
WESTERN KANSAS. WITH AFTERNOON MIXING WE SHOULD SEE HIGHS CLIMBING
IN THE MID AND UPPER 70S. WINDS MAY GUST AS HIGH AS TO 10 TO 15 KNOTS
THROUGH MIDDAY BUT SHOULD BECOME FAIRLY LIGHT THROUGH THE AFTERNOON
HOURS.
TONIGHT THE SHORTWAVE RIDGE MOVES EAST OF THE AREA WITH THE MID
LEVEL FLOW BECOMING MORE SOUTHWESTERLY IN ADVANCE OF AN UPPER
TROUGH APPROACHING THE WEST COAST. WEAK LEE TROUGHING ALONG THE
EASTERN SLOPES WILL BRING WINDS BACK TO THE SOUTH. THE BOUNDARY
LAYER WILL REMAIN DRY SO WE SHOULD SEE CLEAR CONDITIONS OVERNIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 358 AM CDT MON MAR 12 2012
UPPER-LEVEL TROUGHING WILL PERSIST THROUGH MARCH 18TH ACROSS THE FAR
WESTERN UNITED STATES, THEN SLOWLY PROGRESS EASTWARD AND AMPLIFY
JUST TO OUR WEST BY MARCH 19-20TH. GIVEN THE EXPECTED POSITIONING OF
THIS TROUGH OVER THE FAR WESTERN UNITED STATES BY MID-WEEK,
SOUTHWESTERLY MID-LEVEL FLOW WILL BE PRESENT ACROSS THE ROCKIES AND
OVER THE PLAINS. LEE TROUGHING WILL DEVELOP IN RESPONSE TO THE FLOW
ACROSS THE ROCKIES, AND THIS WILL SERVE TO DRAW RICH LOW-LEVEL
MOISTURE NORTHWARD INTO THE SOUTHERN PLAINS. THE SURFACE DRYLINE
WILL MARK THE INTERFACE BETWEEN THE MOIST AIRMASS OVER THE PLAINS
AND THE DRY AIRMASS OVER THE WESTERN HIGH PLAINS AND ROCKIES. IT
WILL BE WARM EVERY DAY THROUGH THE WEEKEND WITH HIGHS IN THE 70S AND
80S AND LOWS FROM THE UPPER 40S WEST TO 55 TO 62 IN SOUTH CENTRAL
KANSAS. OFTENTIMES IN RETURN FLOW SITUATIONS IN MARCH, PREVIOUS COLD
FRONTAL PASSAGES THROUGH THE GULF AND EVEN INTO THE CARIBBEAN RESULT
IN ONLY MODEST MOISTURE RETURNS INTO THE PLAINS. THIS WILL NOT BE
THE CASE THIS WEEK SINCE THE GULF SEA SURFACE IS NEARLY AT
EQUILIBRIUM WITH THE AIR IMMEDIATELY ABOVE. GULF BUOY DATA INDICATE
DEWPOINTS AROUND 70F IN THE CENTRAL GULF CURRENTLY, WHICH IS VERY
IMPRESSIVE FOR THIS TIME OF YEAR. KEEP IN MIND THAT JUST BECAUSE 70F
DEWPOINTS ARE PRESENT IN THE CENTRAL GULF DOESN`T MEAN THAT WE CAN
EXPECT DEWPOINTS THAT HIGH IN SOUTHWEST KANSAS LATER THIS WEEK.
WHEN MOIST, MARINE AIR MOVES NORTHWARD INTO THE PLAINS, DEEP
VERTICAL MIXING OCCURS, WHICH CAUSES THE MOIST LAYER TO BE DEEPER,
BUT NOT QUITE AS RICH. ALSO, DODGE CITY IS 2600FT ABOVE SEA LEVEL
AND THIS INCREASED ELEVATION WILL RESULT IN SOME REDUCTION IN
DEWPOINT AS WELL AS THE MOISTURE MOVES ONTO THE HIGHER TERRAIN. SO
IT IS MORE REASONABLE TO EXPECT DEWPOINT TEMPERATURES FROM THE MID
50S TO THE MID 60S (13-18C) AHEAD OF THE DRYLINE.
BY WEDNESDAY AFTERNOON, THE SURFACE DRYLINE WILL STRETCH FROM A
WEAK SURFACE LOW AND FRONT OVER SOUTHWEST KANSAS SOUTH-SOUTHWESTWARD
INTO THE TEXAS PANHANDLE. A SUBTROPICAL JET STREAK WILL BE SITUATED
ACROSS THE TEXAS PANHANDLE. SURFACE BASED CAPE VALUES WILL APPROACH
2000 J/KG BY LATE AFTERNOON FROM DODGE CITY SOUTH AND EAST. THERE
MAY BE ENOUGH CONVERGENCE ALONG THE DRYLINE AND NEAR THE FRONT-
DRYLINE INTERSECTION, ALONG WITH STRONG ELEVATED HEATING, TO YIELD
ISOLATED THUNDERSTORMS. ANY STORMS THAT DEVELOP COULD BE SEVERE WITH
LARGE HAIL.
ISOLATED THUNDERSTORMS CANNOT BE RULED ANY DAY THROUGH MARCH 20TH AS THE
SURFACE DRYLINE REMAINS OVER WESTERN KANSAS. THE ECMWF INDICATES
THAT THE BEST CHANCES MAY BE SATURDAY FROM DODGE CITY SOUTHEASTWARD,
AND THEN AGAIN BY MONDAY AND TUESDAY AS THE UPPER-LEVEL TROUGH AND
ASSOCIATED MID-LEVEL COOLING APPROACH WESTERN KANSAS. ANY STORMS
THAT DEVELOP IN THESE PERIODS COULD BE SEVERE, ALTHOUGH THE BEST
CHANCE OF HIGH-END SEVERE STORMS WITH TORNADOES SHOULD BE LATER
MONDAY OR TUESDAY AS THE MID TO HIGH-LEVEL WINDS BECOME MUCH
STRONGER IN ADVANCE OF THE UPPER-LEVEL TROUGH. OF COURSE, A LOT
COULD CHANGE BETWEEN NOW AND MARCH 19TH-20TH; AND IT IS IMPOSSIBLE
TO SAY AT THIS POINT EXACTLY WHERE IN THE PLAINS THE BEST CHANCE
OF THUNDERSTORMS WILL BE.
KEEP IN MIND THAT DUE TO THE VERY WARM EXPECTED TEMPERATURES, RECORD
HIGH NIGHTTIME AND DAYTIME TEMPERATURES ARE POSSIBLE ACROSS WESTERN
KANSAS LATER THIS WEEK AND THIS WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1230 AM CDT MON MAR 12 2012
SOME EARLY MORNING MIST COULD REDUCE VISIBILITIES DOWN TO 5-6 MILES
AT DODGE CITY AND HAYS AT THE BEGINNING OF THIS TAF PERIOD BUT VFR
CONDITIONS SHOULD QUICKLY RETURN AND PREVAIL THROUGH THE REMAINDER OF
THE PERIOD. SOUTHERLY WINDS WILL SWITCH AROUND TO THE WEST BY 12Z AND
INCREASE INTO THE 10 TO 15 KNOT RANGE DURING THE MORNING HOURS.
&&
.FIRE WEATHER...
ISSUED AT 402 AM CDT MON MAR 12 2012
FIRE WEATHER WILL BE A CONCERN ON TUESDAY. AFTERNOON VERTICAL
MIXING WILL RESULT IN RELATIVE HUMIDITIES FROM 10 TO 15 PERCENT
ALONG WITH FREQUENT WIND GUSTS NEAR OR JUST IN EXCESS OF 25 MPH.
A FIRE WEATHER WATCH IS IN EFFECT ALONG AND WEST OF A LINE FROM
MEADE TO DIGHTON. THIS WAS NOT UPGRADED SINCE THERE IS SOME
QUESTION AS TO WHETHER SURFACE WINDS WILL BE STRONG ENOUGH. ALSO
ELLIS AND TREGO COUNTIES MAY NEED TO BE ADDED.
AFTER A LESSENING OF THE PRESSURE GRADIENT WEDNESDAY AND THURSDAY,
FIRE WEATHER WILL BE A CONCERN EVERY DAY FROM FRIDAY THROUGH SUNDAY,
ESPECIALLY IN FAR WESTERN KANSAS BEHIND THE SURFACE DRYLINE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 77 41 83 46 / 0 0 0 0
GCK 76 39 82 42 / 0 0 0 0
EHA 75 38 82 41 / 0 0 0 0
LBL 76 39 81 42 / 0 0 0 0
HYS 78 42 82 46 / 0 0 0 0
P28 78 44 81 53 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR KSZ043-044-061>063-074>077-084>087.
DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR KSZ065-066-
079>081-089-090.
&&
$$
UPDATE...BURKE
SHORT TERM...GERARD
LONG TERM....FINCH
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
400 AM CDT MON MAR 12 2012
...UPDATED FOR LONG TERM DISCUSSION...
.UPDATE...
ISSUED AT 821 PM CDT SUN MAR 11 2012
THE UPPER LEVEL LOW WAS PULLING OUT FASTER THAN PREVIOUSLY
THOUGHT, AS WAS THE LOW LEVEL PRESSURE SYSTEM. A FEW SHOWERS MAY
MOVE THROUGH THE NORTHEASTERN SIDE OF OUR CWA IN THE WRAPAROUND,
BUT THESE SHOULD BE FAR AND FEW BETWEEN, AND VERY LIGHT IN
PRECIPITATION AMOUNTS. WILL ONLY LEAVE PRECIP CHANCES IN THE
NORTHEAST FOR A FEW HOURS, THEN DIMINISH THEM ALL TOGETHER. I
REDUCED QPF TO .01-INCH. THE REST OF FORECAST WILL REMAIN THE
SAME.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 347 AM CDT MON MAR 12 2012
MAIN FORECAST CONCERN DURING THE SHORT TERM WILL BE AREAS OF DENSE
FOG OVER SOUTH CENTRAL KANSAS EARLY THIS MORNING. LOW CLOUD
ENHANCEMENT CHANNEL HAS BEEN SHOWING AREAS OF FOG WITH SOME PATCHY
DENSE FOG GENERALLY ALONG AND EAST OF HIGHWAY 183 SINCE BEFORE
MIDNIGHT. IN THE PAST HOUR THIS AREA HAS EXPANDED AND FILLED IN
CONSIDERABLY WITH AWOS OBS INDICATING A QUARTER MILE OR LESS AT
PRATT AND MEDICINE LODGE. HRRR VISIBILITY HAS BEEN HINTING AT THIS
AS WELL. WINDS CONTINUE TO BE LIGHT FROM THE EAST IN THIS AREA SO
THINK THAT WE WILL SEE THESE CONDITIONS CONTINUE THROUGH ABOUT
SUNRISE. WINDS WILL BE SWITCHING TO A WESTERLY DOWNSLOPE COMPONENT
BY THEN SO THE FOG SHOULD BE FAIRLY SHORT LIVED AFTER SUNRISE.
THE REST OF TODAY WILL BE A PLEASANT SPRINGLIKE DAY. A SHORTWAVE
RIDGE MOVES EAST OVER THE CENTRAL HIGH PLAINS WITH WARMER TEMPERATURES
IN THE LOWER TO MID LEVELS OF THE ATMOSPHERE ADVECTING BACK OUT OVER
WESTERN KANSAS. WITH AFTERNOON MIXING WE SHOULD SEE HIGHS CLIMBING
IN THE MID AND UPPER 70S. WINDS MAY GUST AS HIGH AS TO 10 TO 15 KNOTS
THROUGH MIDDAY BUT SHOULD BECOME FAIRLY LIGHT THROUGH THE AFTERNOON
HOURS.
TONIGHT THE SHORTWAVE RIDGE MOVES EAST OF THE AREA WITH THE MID
LEVEL FLOW BECOMING MORE SOUTHWESTERLY IN ADVANCE OF AN UPPER
TROUGH APPROACHING THE WEST COAST. WEAK LEE TROUGHING ALONG THE
EASTERN SLOPES WILL BRING WINDS BACK TO THE SOUTH. THE BOUNDARY
LAYER WILL REMAIN DRY SO WE SHOULD SEE CLEAR CONDITIONS OVERNIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 358 AM CDT MON MAR 12 2012
UPPER-LEVEL TROUGHING WILL PERSIST THROUGH MARCH 18TH ACROSS THE FAR
WESTERN UNITED STATES, THEN SLOWLY PROGRESS EASTWARD AND AMPLIFY
JUST TO OUR WEST BY MARCH 19-20TH. GIVEN THE EXPECTED POSITIONING OF
THIS TROUGH OVER THE FAR WESTERN UNITED STATES BY MID-WEEK,
SOUTHWESTERLY MID-LEVEL FLOW WILL BE PRESENT ACROSS THE ROCKIES AND
OVER THE PLAINS. LEE TROUGHING WILL DEVELOP IN RESPONSE TO THE FLOW
ACROSS THE ROCKIES, AND THIS WILL SERVE TO DRAW RICH LOW-LEVEL
MOISTURE NORTHWARD INTO THE SOUTHERN PLAINS. THE SURFACE DRYLINE
WILL MARK THE INTERFACE BETWEEN THE MOIST AIRMASS OVER THE PLAINS
AND THE DRY AIRMASS OVER THE WESTERN HIGH PLAINS AND ROCKIES. IT
WILL BE WARM EVERY DAY THROUGH THE WEEKEND WITH HIGHS IN THE 70S AND
80S AND LOWS FROM THE UPPER 40S WEST TO 55 TO 62 IN SOUTH CENTRAL
KANSAS. OFTENTIMES IN RETURN FLOW SITUATIONS IN MARCH, PREVIOUS COLD
FRONTAL PASSAGES THROUGH THE GULF AND EVEN INTO THE CARIBBEAN RESULT
IN ONLY MODEST MOISTURE RETURNS INTO THE PLAINS. THIS WILL NOT BE
THE CASE THIS WEEK SINCE THE GULF SEA SURFACE IS NEARLY AT
EQUILIBRIUM WITH THE AIR IMMEDIATELY ABOVE. GULF BUOY DATA INDICATE
DEWPOINTS AROUND 70F IN THE CENTRAL GULF CURRENTLY, WHICH IS VERY
IMPRESSIVE FOR THIS TIME OF YEAR. KEEP IN MIND THAT JUST BECAUSE 70F
DEWPOINTS ARE PRESENT IN THE CENTRAL GULF DOESN`T THEN THAT WE
CAN EXPECT DEWPOINTS THAT HIGH IN SOUTHWEST KANSAS LATER THIS WEEK.
WHEN MOIST, MARINE AIR MOVES NORTHWARD INTO THE PLAINS, DEEP VERTICAL
MIXING OCCURS, WHICH CAUSES THE MOIST LAYER TO BE DEEPER, BUT NOT
QUITE AS RICH. ALSO, DODGE CITY IS 2600FT ABOVE SEA LEVEL AND THIS
INCREASED ELEVATION WILL RESULT IN SOME REDUCTION IN DEWPOINT AS
WELL AS THE MOISTURE MOVES ONTO THE HIGHER TERRAIN. SO IT IS MORE
REASONABLE TO EXPECT DEWPOINT TEMPERATURES FROM THE MID 50S TO THE
MID 60S (13-18C) AHEAD OF THE DRYLINE.
BY WEDNESDAY AFTERNOON, THE SURFACE DRYLINE WILL STRETCH FROM A
WEAK SURFACE LOW AND FRONT OVER SOUTHWEST KANSAS SOUTH-SOUTHWESTWARD
INTO THE TEXAS PANHANDLE. A SUBTROPICAL JET STREAK WILL BE SITUATED
ACROSS THE TEXAS PANHANDLE. SURFACE BASED CAPE VALUES WILL APPROACH
2000 J/KG BY LATE AFTERNOON FROM DODGE CITY SOUTH AND EAST. THERE
MAY BE ENOUGH CONVERGENCE ALONG THE DRYLINE AND NEAR THE FRONT-
DRYLINE INTERSECTION, ALONG WITH STRONG ELEVATED HEATING, TO YIELD
ISOLATED THUNDERSTORMS. ANY STORMS THAT DEVELOP COULD BE SEVERE WITH
LARGE HAIL.
ISOLATED THUNDERSTORMS CANNOT BE RULED ANY DAY THROUGH MARCH 20TH AS THE
SURFACE DRYLINE REMAINS OVER WESTERN KANSAS. THE ECMWF INDICATES
THAT THE BEST CHANCES MAY BE SATURDAY FROM DODGE CITY SOUTHEASTWARD,
AND THEN AGAIN BY MONDAY AND TUESDAY AS THE UPPER-LEVEL TROUGH AND
ASSOCIATED MID-LEVEL COOLING APPROACHE WESTERN KANSAS. ANY STORMS
THAT DEVELOP IN THESE PERIODS COULD BE SEVERE, ALTHOUGH THE BEST
CHANCE OF HIGH-END SEVERE STORMS WITH TORNADOES SHOULD BE LATER
MONDAY OR TUESDAY AS THE MID TO HIGH-LEVEL WINDS BECOME MUCH
STRONGER IN ADVANCE OF THE UPPER-LEVEL TROUGH. OF COURSE, A LOT
COULD CHANGE BETWEEN NOW AND MARCH 19TH-20TH, AND IT IS IMPOSSIBLE
TO SAY AT THIS POINT EXACTLY WHERE IN THE PLAINS THE BEST CHANCE OF
THUNDERSTORMS WILL BE.
KEEP IN MIND THAT DUE TO THE VERY WARM EXPECTED TEMPERATURES, RECORD
HIGH NIGHTTIME AND DAYTIME TEMPERATURES ARE POSSIBLE ACROSS WESTERN
KANSAS LATER THIS WEEK AND THIS WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1230 AM CDT MON MAR 12 2012
SOME EARLY MORNING MIST COULD REDUCE VISIBILITIES DOWN TO 5-6 MILES
AT DODGE CITY AND HAYS AT THE BEGINNING OF THIS TAF PERIOD BUT VFR
CONDITIONS SHOULD QUICKLY RETURN AND PREVAIL THROUGH THE REMAINDER OF
THE PERIOD. SOUTHERLY WINDS WILL SWITCH AROUND TO THE WEST BY 12Z AND
INCREASE INTO THE 10 TO 15 KNOT RANGE DURING THE MORNING HOURS.
&&
.FIRE WEATHER...
ISSUED AT 403 AM CDT SUN MAR 11 2012
RED FLAG WARNING CRITERIA MAY BE MET TUESDAY BEHIND THE SURFACE DRYLINE
ALONG AND WEST OF A LINE FROM DIGHTON TO GARDEN CITY TO LIBERAL.
MID-LEVEL MOMENTUM IS EXPECTED TO EASILY MIX TO THE SURFACE DURING
THE AFTERNOON WITH WIND GUSTS AS HIGH AS 25-30 KTS FOR A FEW
HOURS, ALONG WITH RELATIVE HUMIDITY VALUES BETWEEN 10 AND 15
PERCENT.
FIRE WEATHER MAY ALSO BE A CONCERN JUST ABOUT EVERY DAY IN FAR
SOUTHWEST KANSAS BEHIND THE DRYLINE FROM WEDNESDAY THROUGH THE
WEEKEND, BUT PARTICULARLY FROM FRIDAY INTO SUNDAY AS SURFACE
PRESSURES FALL IN THE LEE OF THE ROCKIES AND SURFACE WINDS
INCREASE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 77 41 83 46 / 0 0 0 0
GCK 76 39 82 42 / 0 0 0 0
EHA 75 38 82 41 / 0 0 0 0
LBL 76 39 81 42 / 0 0 0 0
HYS 78 42 82 46 / 0 0 0 0
P28 78 44 81 53 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR KSZ043-044-061>063-074>077-084>087.
DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR KSZ065-066-
079>081-089-090.
&&
$$
UPDATE...BURKE
SHORT TERM...GERARD
LONG TERM....FINCH
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
347 AM CDT MON MAR 12 2012
...UPDATED FOR SHORT TERM DISCUSSION...
.UPDATE...
ISSUED AT 821 PM CDT SUN MAR 11 2012
THE UPPER LEVEL LOW WAS PULLING OUT FASTER THAN PREVIOUSLY
THOUGHT, AS WAS THE LOW LEVEL PRESSURE SYSTEM. A FEW SHOWERS MAY
MOVE THROUGH THE NORTHEASTERN SIDE OF OUR CWA IN THE WRAPAROUND,
BUT THESE SHOULD BE FAR AND FEW BETWEEN, AND VERY LIGHT IN
PRECIPITATION AMOUNTS. WILL ONLY LEAVE PRECIP CHANCES IN THE
NORTHEAST FOR A FEW HOURS, THEN DIMINISH THEM ALL TOGETHER. I
REDUCED QPF TO .01-INCH. THE REST OF FORECAST WILL REMAIN THE
SAME.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 347 AM CDT MON MAR 12 2012
MAIN FORECAST CONCERN DURING THE SHORT TERM WILL BE AREAS OF DENSE
FOG OVER SOUTH CENTRAL KANSAS EARLY THIS MORNING. LOW CLOUD
ENHANCEMENT CHANNEL HAS BEEN SHOWING AREAS OF FOG WITH SOME PATCHY
DENSE FOG GENERALLY ALONG AND EAST OF HIGHWAY 183 SINCE BEFORE
MIDNIGHT. IN THE PAST HOUR THIS AREA HAS EXPANDED AND FILLED IN
CONSIDERABLY WITH AWOS OBS INDICATING A QUARTER MILE OR LESS AT
PRATT AND MEDICINE LODGE. HRRR VISIBILITY HAS BEEN HINTING AT THIS
AS WELL. WINDS CONTINUE TO BE LIGHT FROM THE EAST IN THIS AREA SO
THINK THAT WE WILL SEE THESE CONDITIONS CONTINUE THROUGH ABOUT
SUNRISE. WINDS WILL BE SWITCHING TO A WESTERLY DOWNSLOPE COMPONENT
BY THEN SO THE FOG SHOULD BE FAIRLY SHORT LIVED AFTER SUNRISE.
THE REST OF TODAY WILL BE A PLEASANT SPRINGLIKE DAY. A SHORTWAVE
RIDGE MOVES EAST OVER THE CENTRAL HIGH PLAINS WITH WARMER TEMPERATURES
IN THE LOWER TO MID LEVELS OF THE ATMOSPHERE ADVECTING BACK OUT OVER
WESTERN KANSAS. WITH AFTERNOON MIXING WE SHOULD SEE HIGHS CLIMBING
IN THE MID AND UPPER 70S. WINDS MAY GUST AS HIGH AS TO 10 TO 15 KNOTS
THROUGH MIDDAY BUT SHOULD BECOME FAIRLY LIGHT THROUGH THE AFTERNOON
HOURS.
TONIGHT THE SHORTWAVE RIDGE MOVES EAST OF THE AREA WITH THE MID
LEVEL FLOW BECOMING MORE SOUTHWESTERLY IN ADVANCE OF AN UPPER
TROUGH APPROACHING THE WEST COAST. WEAK LEE TROUGHING ALONG THE
EASTERN SLOPES WILL BRING WINDS BACK TO THE SOUTH. THE BOUNDARY
LAYER WILL REMAIN DRY SO WE SHOULD SEE CLEAR CONDITIONS OVERNIGHT.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 323 PM CDT SUN MAR 11 2012
THE THEME FOR THE EXTENDED PERIOD IS WARM TEMPS (WELL ABOVE NORMAL
TEMPERATURES...20 TO 30 DEGREES ABOVE NORMAL) AND SOME SMALL CHANCES
FOR THUNDERSTORMS LATE IN THE PERIOD.
FOR TUESDAY, THE LEE SURFACE TROUGH WILL STRENGTHEN WITH SW 20 TO 30
KT OF WIND DEVELOPING AT 850 HPA AND AROUND 15 TO 20 MPH
SOUTHWESTERLY DOWNSLOPE WINDS EXPECTED AT THE SFC. THIS WILL RESULT
IN A WELL MIXED ATMOSPHERE WITH RESULTANT GUSTY SOUTHWESTERLY WINDS.
MIXING FROM FORECAST SOUNDINGS IS EXPECTED TO ABOUT 700 HPA. MIX
DOWN TEMPERATURES SUPPORT LOW TO MID 80S DEG F ACROSS MUCH OF SW
KANSAS. DEWPOINTS WILL MIX DOWN TO LOW 20S DEG F TO POSSIBLY UPPER
TEENS DEG F WHICH WILL RESULT IN RH`S CRASHING DOWN TO 10 TO 15
PERCENT. AS A RESULT OF THE AFOREMENTIONED CONCERNS, HAVE ISSUED A
FIRE WEATHER WATCH (RFW) FOR TUESDAY AFTERNOON FOR FAR WESTERN
KANSAS.
BEYOND TUESDAY, A BROAD UPPER AND LOW LEVEL RIDGE ACROSS THE
SOUTHEAST ALONG WITH CONTINUED LEE SURFACE TROUGHING WILL RESULT IN
RETURN FLOW ACROSS THE SOUTHERN/CENTRAL PLAINS. THE DRYLINE SHOULD
BEGIN TO SHARPEN WEDNESDAY WITH UPPER 50S DEG F DEWPOINTS SOUTH OF
THE DRYLINE LOCATED ACROSS SOUTH CENTRAL/SE KANSAS. THE INCREASING
DEWPOINTS WILL LEAD TO MILD LOWS TOWARDS KP28 THROUGH THE REST OF
THE PD.
THE DRYLINE WILL EVENTUALLY MIX WESTWARD AS UPPER LEVEL FLOW BECOMES
MORE MERIDIONAL. THE EXACT DRYLINE POSITION FOR ANY GIVEN DAY IS
UNCERTAIN AT THIS POINT, HOWEVER...THE GENERAL TREND IN THE MODELS
IS TO MIX THE DRYLINE WESTWARD THROUGH THE END OF NEXT WEEK.
THE DRYLINE IN COMBINATION WITH WEAK IMPULSES EMBEDDED IN THE FLOW
ALOFT COULD LEAD TO SOME ISOLATED CONVECTION BEGINNING THURSDAY AND
CONTINUING THROUGH THE WEEKEND. DID NOT DEVIATE FROM THE ALLBLEND
APPROACH AS CONFIDENCE IN STORM INITIATION IS LOW AT THIS POINT. THE
BEST LOCATION FOR SEEING THUNDERSTORM ACTIVITY WILL BE ACROSS SOUTH
CENTRAL KANSAS WHERE BETTER BOUNDARY LAYER MOISTURE/HIGHER CAPE
VALUES IS EXPECTED. CAPPING COULD BE A CONCERN, PARTICULARLY IF YOU
BUY THE WARMER AND DRIER ECMWF.
LOOKING AT WEEK TWO, THE MODELS CONTINUE TO STRUGGLE WITH TIMING OF
THE EJECTION OF THE UPPER LEVEL TROUGH. BY MARCH 19TH, UL FLOW
BECOMES STRONGER AND MORE SOUTHERLY. CAPE VALUES FROM THE ECMWF SHOW
AROUND 2000 J/KG AND 0 TO 6 KM SHEAR INCREASES TO AROUND 50 KT. AT
SOME POINT SEVERE WEATHER COULD BE A SIGNIFICANT CONCERN...
PARTICULARLY AS THE UPPER LEVEL WAVE FINALLY EJECTS OUT ACROSS THE
PLAINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1230 AM CDT MON MAR 12 2012
SOME EARLY MORNING MIST COULD REDUCE VISIBILITIES DOWN TO 5-6 MILES
AT DODGE CITY AND HAYS AT THE BEGINNING OF THIS TAF PERIOD BUT VFR
CONDITIONS SHOULD QUICKLY RETURN AND PREVAIL THROUGH THE REMAINDER OF
THE PERIOD. SOUTHERLY WINDS WILL SWITCH AROUND TO THE WEST BY 12Z AND
INCREASE INTO THE 10 TO 15 KNOT RANGE DURING THE MORNING HOURS.
&&
.FIRE WEATHER...
ISSUED AT 403 AM CDT SUN MAR 11 2012
RED FLAG WARNING CRITERIA MAY BE MET TUESDAY BEHIND THE SURFACE DRYLINE
ALONG AND WEST OF A LINE FROM DIGHTON TO GARDEN CITY TO LIBERAL.
MID-LEVEL MOMENTUM IS EXPECTED TO EASILY MIX TO THE SURFACE DURING
THE AFTERNOON WITH WIND GUSTS AS HIGH AS 25-30 KTS FOR A FEW
HOURS, ALONG WITH RELATIVE HUMIDITY VALUES BETWEEN 10 AND 15
PERCENT.
FIRE WEATHER MAY ALSO BE A CONCERN JUST ABOUT EVERY DAY IN FAR
SOUTHWEST KANSAS BEHIND THE DRYLINE FROM WEDNESDAY THROUGH THE
WEEKEND, BUT PARTICULARLY FROM FRIDAY INTO SUNDAY AS SURFACE
PRESSURES FALL IN THE LEE OF THE ROCKIES AND SURFACE WINDS
INCREASE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 77 41 83 46 / 0 0 0 0
GCK 76 39 82 42 / 0 0 0 0
EHA 75 38 82 41 / 0 0 0 0
LBL 76 39 81 42 / 0 0 0 0
HYS 78 42 82 46 / 0 0 0 0
P28 78 44 81 53 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR KSZ043-044-061>063-074>077-084>087.
DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR KSZ065-066-
079>081-089-090.
&&
$$
UPDATE...BURKE
SHORT TERM...GERARD
LONG TERM....SUDDEN
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
521 PM EDT MON MAR 12 2012
.SYNOPSIS...
AN UPPER-LEVEL DISTURBANCE WILL PASS THROUGH THE REGION TONIGHT
CAUSING SOME SHOWERS. HIGH PRESSURE WILL REMAIN OVER THE WESTERN
ATLANTIC DURING THE MIDDLE PORTION OF THE WEEK AND A SOUTHERLY FLOW
AROUND THE HIGH WILL USHER IN UNUSUALLY WARM CONDITIONS FOR THIS
TIME OF YEAR. A COLD FRONT WILL STALL OUT NEAR THE REGION LATE IN
THE WEEK INTO THE WEEKEND...BRINGING UNSETTLED CONDITIONS.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
2030Z UPDATE...RADAR INDICATES SHOWERS HAVE MOVED INTO THE POTOMAC
HIGHLANDS. HRRR INDICATES POTENTIAL FOR ANOTHER LINE OF SHOWERS TO
DEVELOP FURTHER EAST. INCREASED POPS TO CHANCE ACROSS THE NORTHERN
SHENANDOAH VALLEY...NORTHERN VA AND N CNTRL MD THIS EVENING.
PREVIOUS DISCUSSION...
AN UPPER-LEVEL RIDGE AXIS WILL SHIFT EAST TONIGHT WHILE UPPER-
LEVEL LOW PRESSURE TRACKS THROUGH THE GREAT LAKES AND INTO
SOUTHERN CANADA. A SOUTHERLY FLOW AROUND SURFACE HIGH PRESSURE
OVER THE ATLANTIC HAS BROUGHT ABNORMALLY WARM CONDITIONS TO THE
REGION THIS AFTERNOON. THE SOUTHERLY FLOW WILL CAUSE DEEP MOISTURE
TO MOVE INTO THE REGION TONIGHT. A WEAK AREA OF CONVERGENCE
ASSOCIATED WITH THE DEPARTING RIDGE AXIS WILL COMBINE WITH THE
MOISTURE TO TRIGGER SHOWERS ACROSS PORTIONS OF THE AREA. DESPITE
THE RAPID INCREASE IN MOISTURE...RAINFALL AMOUNTS WILL BE LIGHT
DUE TO THE WEAK FORCING. RAINFALL AMOUNTS WILL AVERAGE LESS THAN
ONE TENTH OF AN INCH ACROSS MOST LOCATIONS...BUT PERHAPS AROUND A
QUARTER INCH ACROSS THE ALLEGHENY AND POTOMAC HIGHLANDS.
MIN TEMPS WILL BE MUCH MILDER THAN RECENT NIGHTS DUE TO CLOUD COVER
AND A SOUTHERLY FLOW. MIN TEMPS WILL RANGE FROM THE MID AND UPPER
40S IN THE POTOMAC HIGHLANDS TO THE MID 50S IN WASHINGTON/BALTIMORE.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
UPPER-LEVEL LOW PRESSURE WILL CONTINUE TO TRACK THROUGH SOUTHERN
CANADA TUESDAY WHILE A SURFACE PRESSURE TROUGH DEVELOPS OVER THE
REGION. A SOUTHWEST FLOW AROUND HIGH PRESSURE OVER THE ATLANTIC WILL
USHER IN EVEN WARMER CONDITIONS TUESDAY. THE DRY SLOT ASSOCIATED
WITH THE UPPER-LEVEL LOW WILL MOVE INTO THE REGION CAUSING SOME
SUNSHINE. SUNSHINE ALONG WITH A SOUTHWEST FLOW WILL ALLOW FOR MAX
TEMPS TO SOAR INTO THE 70S ACROSS MOST LOCATIONS. A FEW LOCATIONS
ACROSS CENTRAL VIRGINIA MAY REACH 80 DEGREES.
UNUSUALLY WARM AIR ALONG WITH DEWPOINTS IN THE 50S WILL CAUSE
MODERATE INSTABILITY TO DEVELOP. THE NAM/GFS BUFKIT INDICATE ABOUT
500-1000J/KG OF MLCAPE DEVELOPING TUESDAY AFTERNOON. INSTABILITY
WILL COMBINE WITH FORCING FROM THE SURFACE TROUGH FOR POSSIBLE
T-STORMS TUESDAY AFTERNOON. HOWEVER...T-STORMS WILL BE FIGHTING WITH
MID-LEVEL DRY AIR AND SUBSIDENCE. ANY T-STORMS THAT DO DEVELOP WILL
BE ISOLATED TO PERHAPS SCATTERED. THE BEST CHANCE FOR T-STORMS WILL
BE NEAR AND EAST OF THE I-95 CORRIDOR LATER TUESDAY AFTERNOON. IF
T-STORMS DO DEVELOP THAN MID-LEVEL DRY AIR AND AN INVERTED V
SIGNATURE IN THE SOUNDINGS SUGGEST THAT GUSTY WINDS AND HAIL ARE
POSSIBLE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE ERN HALF OF THE CONUS AND PAC NW WILL BE PARTICULARLY ACTIVE
OVER THE COMING WEEK. ACTIVITY OVER THE ERN HALF WILL BE MORE OF A
SLOW BOIL. A LEFTOVER FRONTAL BOUNDARY WILL STALL FROM THE SRN MS
VLY TO THE OHIO VLY...ALLOWING DISORGANIZED BATCHES OF SHOWERS/TSTMS
TO DEVELOP DAILY ON THE WRN SIDE OF A SLOW-MOVING UPPER RIDGE. THE
RIDGE WILL TEMPORARILY BOUNCED TO SOUTH WHILE THE TUESDAY UPPER
TROF SLIDES BY TO THE NORTH. THE RIDGE WILL BUILD BACK UP THE
SOUTHEAST AND SLOWLY INCH TOWARD THE SRN ATLC COAST BY THE END OF
THE WEEK. AS IT APPROACHES...CHANCES FOR SCATTERED SHOWER/TSTM
ACTIVITY INCREASES ACROSS THE DEEP SOUTH AND INTO THE MID ATLC
REGION.
IN BETWEEN ANY POTENTIAL RAINFALL FOR THE AREA IN THE COMING DAYS...
TEMPS WILL BE ALLOWED TO RISE WELL ABOVE NORMAL - NEAR RECORD
VALUES. WITH AVG HIGHS THIS TIME OF YEAR IN THE M50S /LOWS IN THE
M30S/...HIGHS MOST DAYS THIS WEEK WILL TOP OUT WELL INTO THE
70S/NEAR 80...AND 50S FOR OVERNIGHT LOWS. THE SLOW-MOVING HIGH
PRESSURE RIDGE ACROSS THE DEEP SOUTH WILL BE RESPONSIBLE FOR THESE
FEW STRAIGHT DAYS OF MUCH WARMER WX.
TOWARD THE END OF THE WEEK...THE WEAK/MODERATE ACTIVITY ACROSS THE
MS AND TENN VLY REGIONS WILL MAKE IT TO THE EAST COAST. POPS FOR FRI
AND SAT HAVE BEEN INCREASED TO AT LEAST HIGH-CHANCE RANGE BUT MOSTLY
OF THE WIDELY SCATTERED VARIETY COMING OVER TOP THE UPPER RIDGE.
HEADING INTO THE WEEKEND AND EARLY NEXT WEEK...ANOTHER PATTERN
CHANGE. EARLY INDICATIONS ARE THAT A LARGE AND POTENT UPPER TROF
WILL DIG DOWN THE PACIFIC COAST. THIS UPPER WAVE WILL ENCOMPASS THE
ENTIRE WRN HALF OF THE CONUS AT LEAST THE FIRST HALF OF THE WEEK
BEFORE MOVING INTO THE CNTRL PLAINS. MEANWHILE...THE ERN HALF WILL
BE UNDER A LARGE DOME OF HIGH PRESSURE.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
VFR CONDITIONS EXPECTED THROUGH TONIGHT. GUSTS HAVE ENDED AT SOME
TERMINALS...BUT CONTINUE AT KDCA/KCHO. GUSTS AT THESE TERMINALS
SHOULD END OR AT LEAST BE SPORADIC BY 23Z.
SHOWERS ARE LIKELY TONIGHT AS A DISTURBANCES MOVES THROUGH.
CIGS/VSBYS MAY APPROACH MVFR LEVELS LATE TONIGHT IN SHOWERS. VFR
CONDITIONS ARE EXPECTED TUESDAY WITH SOUTHWEST WINDS GUSTING UP TO
20 KNOTS IN THE AFTERNOON. ISOLATED/SCATTERED T-STORMS ARE POSSIBLE
TUESDAY AFTERNOON. IF T-STORMS DO DEVELOP...GUSTY WINDS AND HAIL
CANNOT BE RULED OUT. THE BEST CHANCE FOR T-STORMS WILL BE ACROSS THE
EASTERN TERMINALS LATE TUESDAY AFTERNOON.
RAIN CHANCES LOW WED-THU AS A LARGE AREA OF GULF MOISTURE MOVES
TOWARD THE ATLC COAST. INGREDIENTS WILL COME TOGETHER BETTER THU
NIGHT INTO FRI FROM SCATTERED SHOWERS...A FEW ISOLATED TSTMS. SAME
STORY INTO SAT...W/ THIS ACTIVITY EXITING OFF THE COAST LATE SAT
INTO SUN. WINDS DURING THE MED-LONG RANGE FORECAST ARE SOME OF THE
LIGHTEST IN A WHILE...MOST DAYS WE WILL SEE SFC WINDS 10KT OR LESS.
&&
.MARINE...
A SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH TONIGHT FOR THE
WATERS. SOUTHERLY WINDS LATE THIS AFTERNOON WILL GUST UP TO 20
KNOTS. AN UPPER-LEVEL DISTURBANCE WILL PASS THROUGH THE WATERS
TONIGHT LIKELY BRINGING SHOWERS. WIND GUSTS AROUND 20 KNOTS ARE
EXPECTED ESPECIALLY IN SHOWERS TONIGHT.
HIGH PRESSURE WILL REMAIN OVER THE ATLANTIC TUESDAY ALLOWING FOR A
SOUTHWEST FLOW. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE MIDDLE
PORTION OF THE BAY AND LOWER TIDAL POTOMAC TUESDAY MORNING...AND FOR
ALL THE WATERS TUESDAY AFTERNOON. GUSTS AROUND 20 KNOTS ARE
EXPECTED.
ISOLATED-SCATTERED T-STORMS ARE POSSIBLE TUESDAY AFTERNOON. ANY
T-STORMS THAT DO DEVELOP WILL BE CAPABLE OF PRODUCING GUSTY WINDS
AND HAIL.
A HIGH PRESSURE RIDGE WILL BUILD ACROSS THE SOUTHEAST DURING THE
MIDDLE AND LATTER PART OF THE WEEK...KEEPING THE AREA QUIET THRU
AT LEAST LATE THU. SCATTERED SHOWERS AND ISOLATED TSTMS MAY IMPACT
THE WATERS FRI/SAT...THOUGH WINDS WILL STAY FAIRLY LIGHT
THROUGHOUT THE NEXT SEVERAL DAYS /10KT OR LESS MOST DAYS/.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT TUESDAY FOR ANZ530-531-535-
536-538-539.
SMALL CRAFT ADVISORY FROM NOON TO 6 PM EDT TUESDAY FOR ANZ530-
531-535-536-538-539.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ532>534-537-
540>543.
&&
$$
SYNOPSIS...
NEAR TERM...BJL/KS
SHORT TERM...BJL
LONG TERM...GMS
AVIATION...BJL/GMS/KS
MARINE...BJL/GMS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
320 PM EDT MON MAR 12 2012
.SYNOPSIS...
SOME SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE POSSIBLE
TONIGHT INTO TOMORROW...WITH DRY WEATHER EXPECTED FOR WEDNESDAY.
TEMPERATURES ARE EXPECTED TO BE WELL ABOVE NORMAL FOR THE ENTIRE 7
DAY FORECAST.
&&
.NEAR TERM /THROUGH TUESDAY/...
WIDESPREAD RAINFALL HAS CLEARED OHIO COUNTIES AND CONTINUES TO MOVE
TO THE EAST. HOWEVER...A LINE OF SCATTERED SHOWERS HAS DEVELOPED
ACROSS WESTERN OHIO. IF ANY LIGHTNING IS TO OCCUR...IT WOULD LIKELY
BE WITH THE SECOND LINE OF SHOWERS. ALL RAIN SHOULD CLEAR THE AREA
BY LATE EVENING. A COLD FRONT IS THEN EXPECTED TO CROSS THE EASTERN
GREAT LAKES LATE TONIGHT...AND CLIP THE FORECAST AREA TOMORROW.
FRONT WILL NOT HAVE MUCH MOISTURE TO WORK WITH...AND WILL ONLY GO
CHANCE POPS. ONCE AGAIN...INSTABILITY VALUES WARRANT AT LEAST A
SLIGHT CHANCE OF THUNDER. TEMPERATURES WILL REMAIN NEARLY STEADY
FROM AFTERNOON READINGS THROUGHOUT THE NIGHT...THEN RISE INTO THE
60S TOMORROW. THESE VALUES WILL BE MUCH HIGHER THAN SEASONAL NORMALS
OF MID 40S AND MID 20S.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE RIDGE WILL BUILD IN FROM THE SOUTH TUESDAY
NIGHT...WITH ALL PRECIPITATION HAVING MOVED EAST. THIS WILL KEEP
WEATHER QUIET THROUGH WEDNESDAY NIGHT. ASSOCIATED UPPER LEVEL RIDGE
WILL BEGIN TO MOVE OFFSHORE THURSDAY. 12Z GFS/00Z ECMWF SHOW
SHORTWAVE RIDING UP FROM THE PLAINS...AND WITH SOUTHWESTERLY FLOW
BRINGING IN GULF OF MEXICO MOISTURE...CHANCE OF THUNDERSTORMS WILL
RETURN TO THE FORECAST FOR THURSDAY. HIGHS WILL APPROACH 70 DEGREES
BOTH DAYS...WITH LOWS ALSO ABOVE NORMAL...IN THE 40S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
BLEND OF HPC-PREFERRED ECMWF ENSEMBLE MEAN AND NAEFS MODEL OUTPUT
SHOW THE UPPER LEVEL JETSTREAM REMAINING SOUTHWEST IN ORIENTATION
THIS PERIOD. DEEP TROUGHING ALONG THE PACIFIC COAST MAY EVEN RESULT
IN STRONG ENOUGH RIDGING OVER THE EASTERN U.S. TO DEVELOP A BLOCKED
CUTOFF LOW OFF THE ATLANTIC COAST. HENCE EXPECT SPRINGLIKE
TEMPERATURES TO CONTINUE ACROSS THE UPPER OHIO VALLEY THIS PERIOD.
JUDGING FROM THE OPERATIONAL ECMWF, CMC AND GFS, AN EASTBOUND UPPER
LEVEL SHORT-WAVE TROUGH WILL DEVELOP AN OCCLUDED FRONTAL SYSTEM
ACROSS THE MISSISSIPPI VALLEY THURSDAY, THAT WILL BE PRECEDED BY LOW
LEVEL SOUTHERLY WINDS. THE RESULTING LIFT AND INFLUX OF GULF
MOISTURE WILL RESULT IN SHOWERS ACROSS THE UPPER OHIO VALLEY FRIDAY
AND FRIDAY NIGHT.
HAVE CONTINUED A CHANCE OF SHOWERS FOR THE WEEKEND, AS THE SYSTEM
MAY BE SLOW TO EXIT AND REMAINING MOISTURE MAY GENERATE AFTERNOON
INSTABILITY SHOWERS.
FORECASTED TEMPERATURE DETAILS USING HPC-PREFERRED ECMWF MODEL
OUTPUT, TEMPERED WITH SLIGHTLY COOLER GFS MOS AND NAEFS MEDIAN
VALUES. THIS YIELDED LOWS AND HIGHS OF GENERALLY 20 DEGREES WARMER
THAN NORMAL. ALTHOUGH HIGHS CAN BE IN THE 70S, MOST MID-MARCH
RECORD HIGHS ARE CLOSER TO 80.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
EXPECT MVFR CONDITIONS TO LINGER INTO TUESDAY MORNING.
BLEND OF RECENT SURFACE AND RADAR DATA, ALONG WITH HRRR AND NAM
MODEL OUTPUT, SHOW THE WARM FRONTAL BAND OF MVFR SHOWERS WILL EXIT
EAST BY 00Z. THERE CAN BE BRIEF IFR EPISODES.
NOCTURNAL COOLING OF THE RAIN-MOISTENED SURFACE LAYER SHOULD
MAINTAIN MVFR CONDITIONS TONIGHT. A SECOND BAND OF SCATTERED SHOWERS
MAY DELAY IMPROVEMENT TO VFR LEVELS UNTIL TUESDAY AFTERNOON.
WINDS WILL GENERALLY REMAIN SOUTHERLY AT 10KTS WITH GUSTS TO
15-20KTS INTO EARLY EVENING. WINDS WILL THEN BECOME SOUTHWEST AT 5-8
KTS TONIGHT.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
VFR INTO THURSDAY. RESTRICTIONS WITH SHOWERS WILL BE POSSIBLE
THURSDAY NIGHT INTO SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
821 AM EDT MON MAR 12 2012
.SYNOPSIS...
LOW PRESSURE, MOVING NORTHEASTWARD TO WISCONSIN, WILL PUSH A WARM
FRONTAL BAND OF SHOWERS EASTWARD THROUGH THE UPPER OHIO VALLEY
THIS AFTERNOON AND EVENING, FOLLOWED BY A SECOND BAND OF SCATTERED
SHOWERS TUESDAY. HIGH PRESSURE WILL FOLLOW WITH DRY CONDITIONS
INTO THURSDAY AND SPRINGLIKE CONDITIONS INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THIS UPDATE CONSISTED MAINLY OF TWEAKS BASED ON BLEND OF RECENT
SURFACE AND RADAR DATA AND HRRR AND NAM MODEL OUTPUT.
THINKING REMAINS THAT A LOW PRESSURE CENTER, MOVING NORTHEASTWARD
TOWARD WISCONSIN, WILL PUSH A WARM FRONTAL BAND OF NUMEROUS
SHOWERS EASTWARD THROUGH THE UPPER OHIO VALLEY THIS AFTERNOON AND
EVENING. MAINTAINED A SLIGHT CHANCE OF THUNDER, AS SURFACE
TEMPERATURES AND INSTABILITY CAN BE STUNTED BY PRECEDING CLOUD
COVER. FOR EXAMPLE, HIGHS IN EAST CENTRAL OHIO MAY OCCUR MIDDAY.
LOWS TONIGHT CAN BE 15 TO 20 DEGREES WARMER THAN NORMAL PER RECENT
GFS AND NAM MOS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
UPPER LEVEL TROUGH AXIS WILL CROSS THE GREAT LAKES TUESDAY AND
WITH MOIST LOW LEVELS SHOULD BE ABLE TO PRODUCE SCATTERED SHOWERS.
BEHIND THIS DRY CONDITIONS AND WELL ABOVE NORMAL TEMPERATURES
THROUGH WEDNESDAY UNDER SURFACE RIDGE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
THE EXTENDED FORECAST WILL RESEMBLE MORE OF A SPRINGTIME PATTERN
THAN A LATE WINTER PATTERN.
AN UPPER LEVEL RIDGE WILL REMAIN FIXED ALONG THE EAST COAST
THROUGHOUT THE PERIOD. SOUTHERLY WINDS, AHEAD OF GREAT PLAINS LOW
PRESSURE, WILL ADD GULF MOISTURE TO THE SPRINGLIKE WARMTH. HENCE,
DAYTIME SHOWERS AND LATE DAY THUNDERSTORMS MAY BE POSSIBLE BY
LATER THURSDAY. TEMPERATURES WILL REMAIN MORE THAN 15 DEGREES
ABOVE NORMAL ON AVERAGE.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
VFR ALTOCUMULUS CEILINGS WILL LOWER TO STRATOCUMULUS LEVELS LATE
MORNING WITH ONSET OF WARM FRONTAL BAND OF NUMEROUS RAIN SHOWERS
AND ISOLATED THUNDERSTORMS.
LATER THIS AFTERNOON, AS THE RAIN SHOWERS MOISTEN THE SURFACE
LAYER, VISIBILITIES AND CEILINGS CAN LOWER TO MVFR. NOCTURNAL
COOLING CAN HELP MAINTAIN MVFR CONDITIONS TONIGHT.
WINDS WILL GENERALLY REMAIN SOUTHERLY AT 10KTS WITH GUSTS TO 20
KTS THIS AFTERNOON AND EARLY EVENING.
OUTLOOK...TUESDAY THROUGH FRIDAY...
RESTRICTIONS MAY STILL BE POSSIBLE WITH A SECOND FRONTAL BAND OF
SHOWERS TUESDAY MORNING. HIGH PRESSURE WILL PROMOTE VFR LATER TUESDAY
INTO THURSDAY. RESTRICTIONS WITH SHOWERS WILL BE POSSIBLE THURSDAY
NIGHT AND FRIDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
414 PM EDT MON MAR 12 2012
.SYNOPSIS...
ISSUED AT 413 PM EDT MON MAR 12 2012
UNSEASONABLY WARM WEATHER WILL DOMINATE THIS WEEK AS ABOVE NORMAL
500MB HEIGHTS RISE SLOWLY OVERALL. INTO THE UPCOMING WEEKEND...500MB
HEIGHT ANOMALIES OVER THE UPPER LAKES WILL INCREASE FROM 2 TO 2.5
STANDARD DEVIATIONS ABOVE THE LONG TERM AVG FOR MID MARCH. 850MB
TEMPS WILL ALSO BE RUNNING 2-2.5 STANDARD DEVIATIONS ABOVE THE LONG
TERM AVG. OVERALL...IT WILL PROBABLY FEEL MORE LIKE MID MAY THAN MID
MARCH. AT LEAST HERE AT THE OFFICE...SEVERAL HIGH TEMP RECORDS WILL
PROBABLY BE CHALLENGED OVER THE NEXT 7 DAYS. RAIN CHANCES LOOK
LIMITED WITH TROF SETTING UP WELL TO THE W OVER THE WRN CONUS AND A
STRONG RIDGE BUILDING OVER THE ERN CONUS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 413 PM EDT MON MAR 12 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WELL-DEFINED MID LEVEL
LOW SPINNING NE THRU WI. MAIN ARC OF STEADIER PCPN ASSOCIATED WITH
SYSTEM HAS LIFTED N AND E THRU UPPER MI TODAY. SCT PCPN IS OCCURRING
CLOSER TO THE CENTER OF THE MID LEVEL LOW WITH COVERAGE GENERALLY
INCREASING. UNDER APPROACHING COLD POCKET ALOFT ASSOCIATED WITH THE
LOW...A FEW LIGHTNING STRIKES HAVE FINALLY BEEN NOTED OVER CNTRL WI.
AFTER MORNING RAINFALL SATURATED THE LOW-LEVELS AND WITH PCPN LESS
WIDESPREAD THIS AFTN...FOG IS FAIRLY WIDESPREAD WITH SOME AREAS OF
DENSE FOG ALONG LAKE MICHIGAN AND WHERE WINDS ARE UPSLOPING.
WITH MID LEVEL LOW MOVING ACROSS THE AREA THIS EVENING...EXPECT
SCT/NMRS SHRA THIS EVENING. MAINTAINED SLIGHT CHC THUNDER OVER THE
SCNTRL THRU LATE AFTN SINCE SHRA ACTIVITY AROUND LOW APPEARS TO BE
INCREASING IN INTENSITY AND A FEW LIGHTNING STRIKES HAVE RECENTLY
OCCURRED IN CNTRL WI. SHORTWAVE CURRENTLY OVER THE DAKOTAS MAY WORK
TO MAINTAIN BETTER COVERAGE OF SHRA INTO THE LATE EVENING HRS OVER
THE NW PORTION OF THE FCST AREA AS IT TRACKS TO LAKE SUPERIOR.
OTHERWISE...PCPN LOOKS TO END RATHER QUICKLY OVERNIGHT FROM W TO E
AS STRONG DRYING SURGES INTO THE AREA UNDERNEATH UPPER JET.
-SHRA MAY LINGER INTO THE MORNING HRS OVER THE FAR NE FCST AREA.
OTHERWISE...THE STRONG DRYING WILL SET THE STAGE FOR A SUNNY DAY
TUE. DEEP DRY AIRMASS WILL SUPPORT DEEP MIXING...PERHAPS TO
800-750MB. PER FCST SOUNDINGS...THAT WILL YIELD MAX TEMPS AROUND 60F
OVER THE SCNTRL WHERE DOWNSLOPING WRLY WINDS WILL AID WARMING. 50S
SHOULD BE THE RULE ELSEWHERE...WITH LWR 40S ON THE W SIDE OF THE
KEWEENAW AND ALONG LAKE SUPERIOR E OF MUNISING DUE TO WINDS OFF THE
COLD WATERS. GIVEN THE VERY DRY AIRMASS ALOFT THAT CAN BE TAPPED...
LEANED TOWARD DWPTS THAT CAN BE ACHIEVED BY MIXING TUE AFTN.
ALTHOUGH POTENTIAL IS THERE FOR DWPTS TO CRASH TOWARD 0F OVER THE
FAR W AND CNTRL FCST AREA...OPTED TO JUST TREND FCST IN THAT
DIRECTION BY LOWERING GOING FCST SEVERAL DEGREES TO AROUND 10F AS A
START. THIS WILL PUT AFTN RH VALUES DOWN AROUND 15PCT.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 413 PM EDT MON MAR 12 2012
THE PERIOD STARTS 00Z WEDNESDAY WITH A LOW PRESSURE SYSTEM ENE OF
THE CWA AND A 500MB RIDGE OF HIGH PRESSURE CENTERED JUST W OF THE
CWA. AT THE SAME TIME...AN UPPER SHORTWAVE TROUGH WILL BE OVER THE
NWRN CONUS/WRN CANADA...WITH A SFC LOW OVER SASK AND SFC TROUGHING
LEEWARD OF THE ROCKIES STRETCHING INTO CO.
THE UPPER RIDGE WILL BE OVER THE CENTER OF THE CWA BY 12Z WED. THE
NW CONUS SHORTWAVE WILL BE NEAR THE NRN SASK/MANITOBA
BORDER...PUSHING THE SFC TROUGH FARTHER E INTO FAR WRN MN. THE
EASTWARD MOVING TROUGH COMBINED WITH A SFC RIDGE JUST E OF THE CWA
WILL RESULT IN INCREASING SW WAA TUE NIGHT INTO WED. 850MB TEMPS
WILL INCREASE FROM 0-5C BY 00Z WED TO 10-13C BY 18Z WED. THIS
RESULTS IN VERY WARM TEMPS FOR WED...WITH HIGHS IN THE MID TO UPPER
60S EXPECTED OVER PORTIONS OF CENTRAL AND WRN UPPER MI...ESPECIALLY
IN DOWNSLOPING AREAS. OVER ERN UPPER MI...HIGHS WILL BE LOWER IN THE
LOW TO MID 50S WITH THE SSW FLOW OFF LAKE MI. THROUGH 00Z THU THINGS
SHOULD STAY DRY AS THE SFC TROUGH MOVES INTO THE FAR WRN CWA. THE
NAM SHOWS SOME CONVECTION POPPING UP BETWEEN 18Z WED AND 00Z THU
OVER THE FAR ERN CWA...BUT THE NAM IS ALSO THE FASTEST WITH MOVING
THE COLD FRONT THROUGH. WITH THE CONSENSUS IDEA...THE COLD FRONT
WILL BE MOVING OUT OF THE SERN CWA BY 00Z FRI. CONSENSUS MODELS ALSO
SHOW CONVECTION OVER CENTRAL AND ERN UPPER MI...BUT MAINLY NEAR LAKE
MI AND OVER FAR ERN UPPER MI AFTER 00Z THU. THE HEAVIER CONVECTION
SHOULD STAY S/SE OF THE CWA AS MODELS SHOW TOO MUCH CAPPING THIS FAR
N...SO SLIGHT CHANCE OF THUNDER WAS RETAINED FROM PREVIOUS FORECAST.
THURSDAY...WITH THE COLD FRONT STALLING JUST SE OF THE CWA...RAIN
WILL REMAIN POSSIBLE NEAR LAKE MI AND E...BUT ONLY CHANCE TO SLIGHT
CHANCE POPS SEEM WARRANTED AT THIS TIME. THURSDAY LOOKS TO BE COOLER
BEHIND THE COLD FRONT WITH 850MB TEMPS AROUND 7C...SO HIGHS WILL BE
IN THE 40S NEAR LAKE SUPERIOR AND NEAR 60 NEAR THE WI BORDER.
FOR THE EXTENDED...MODELS SHOW ANOTHER UPPER DISTURBANCE MOVING N OF
THE CWA THU NIGHT...WITH AN UPPER RIDGE MOVING OVER THE CWA ON FRI.
AFTER FRI...CONFIDENCE IS DECREASED SOME AS MODELS SHOW DIFFERING
SOLUTIONS WITH THE PASSAGE OF A SERIES OF SHORTWAVES THROUGH MONDAY.
HOWEVER...WARM CONDITIONS ARE A CERTAINTY INTO EARLY NEXT WEEK GIVEN
STEADY S/SW FLOW WITH SFC HIGH PRESSURE E AND LOW PRESSURE W. USED
CONSENSUS OF MODELS THROUGH THE EXTENDED WITH SLIGHT CHANCE TO LOW
CHANCE POPS AS MODELS SHOW SOME PRECIP/CONVECTION IN THE WAA REGIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 147 PM EDT MON MAR 12 2012
COMPLEX AVIATION FORECAST THIS AFTN AS MID LEVEL LOW CURRENTLY OVER
SE MN/SW WI MOVES NORTHEAST. DENSE FOG/VLIFR CONDITIONS HAVE SETTLED
INTO KCMX/KSAW UNDER LOCALLY UPSLOPING WINDS. WITH DOWNSLOPING WINDS
AT KIWD...CONDITIONS HAVE BEEN MVFR AND THAT SHOULD CONTINUE THIS
AFTN. AS NEXT ROUND OF SCT SHRA ARRIVES ALONG WITH SFC TROF...EXPECT
CONDITIONS TO IMPROVE TO MVFR AT KCMX/KSAW BY LATE AFTN. WIND SHIFT
TO SW WILL ALSO HELP IMPROVE CONDITIONS. AS THE LOW MOVES NE
OVERNIGHT...EXPECT A FAIRLY QUICK TRANSITION TO CLEAR SKIES UNDER
STRONG DRYING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 413 PM EDT MON MAR 12 2012
UPPER LEVEL DISTURBANCE AND SURFACE TROF WILL MOVE ENE ACROSS LAKE
SUPERIOR TONIGHT. AHEAD OF THE TROF...SHOWERS AND INCREASINGLY MOIST
AIRMASS WILL SUPPORT SOME FOG...ESPECIALLY OVER WRN AND NRN PORTIONS
OF THE LAKE. FOG SHOULD THIN OUT AFTER TROF PASSES AND WINDS SHIFT
AROUND TO THE W AND INCREASE. WARM AIR ABOVE THE SURFACE WILL LIKELY
KEEP THE MARINE LAYER IN PLACE AND LIMIT THE STRONGER WINDS ALOFT
FROM REACHING THE SURFACE LATE TONIGHT AND TUE. AT THIS TIME...ONLY
EXPECT GUSTS REACHING 30KTS. AFTER TUE...WINDS WILL PROBABLY REMAIN
MOSTLY UNDER 20KTS WITH A RELATIVELY WEAK PRESSURE GRADIENT IN
PLACE. UNSEASONABLY WARM AIRMASS OVER THE UPPER GREAT LAKES WILL
ALSO RESULT IN PERSISTENT MARINE LAYER/STRONG STABILITY OVER THE
LAKE...HELPING TO KEEP WINDS LIGHTER.
&&
.HYDROLOGY...
ISSUED AT 413 PM EDT MON MAR 12 2012
NEAR RECORD TO RECORD SETTING TEMPS YESTERDAY HAS HELPED RIPEN THE
SNOW PACK. RAIN MOVING THROUGH TODAY WILL EXIT THE AREA TONIGHT. THE
BULK OF THE RAIN FELL DURING THE MORNING TO EARLY AFTERNOON HOURS
TODAY...WITH ACCUMULATIONS OF AROUND 0.25 TO 0.70IN. THE
RAIN...COMBINED WITH DEWPOINTS IN THE 40S...WILL HELP TO QUICKEN
SNOWMELT THIS EVENING. AS OF THIS AFTERNOON...LARGER RIVERS ARE
STARTING TO SHOW SOME INCREASED RESPONSE TO THE MELTING AND
PRECIPITATION.
THE RAIN AND SNOW MELT TODAY...COMBINED WITH ABOVE NORMAL
TEMPERATURES THROUGH NEXT WEEKEND WILL LEAD TO A INCREASE IN
RIVER AND STREAM LEVELS OVER THE NEXT SEVERAL DAYS. EXPECT SOME OF
THE RIVERS ACROSS THE AREA TO EXCEED THEIR BANKS BY THE END OF THIS
WEEK. PERSONS LIVING NEAR RIVERS AND STREAMS SHOULD
MONITOR THE LATEST RIVER CONDITIONS AND USE CAUTION IF WALKING
ALONG RIVER BANKS...ESPECIALLY THE CHOCOLAY RIVER...TRAP ROCK
RIVER...AND THE STURGEON RIVER IN WESTERN UPPER MICHIGAN.
ICE JAM WISE...NOT MUCH ICE HAS BEEN NOTED BY OBSERVERS ON THE
FASTER FLOWING RIVERS OVER NRN UPPER MI. BUT THE FORD RIVER...BOTH
AT HYDE AND THE MOUTH AT LK MI...STILL HAS GOOD ICE COVER THAT
LEADS TO SOME CONCERN FOR ICE JAM POTENTIAL WITH THE FASTER RUNOFF.
ALTHOUGH LIMITED SNOW WAS NOTED NEAR LK MI...THERE IS STILL 3-8IN
OF SNOW ...AND NOHRSC ESTIMATED AROUND 1.25IN OF LIQUID...TOWARDS
THE HEADWATERS THAT WILL BE MELTED OVER THE COMING DAYS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ221-248-
250.
&&
$$
SYNOPSIS...ROLFSON
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...ROLFSON
HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
351 PM EDT MON MAR 12 2012
.SHORT TERM...THIS EVENING AND TONIGHT
STRONG UPPER LOW NOW LOCATED OVER NORTHERN WISCONSIN WILL CONTINUE
TO TRACK TO THE NE ACROSS LAKE SUPERIOR TONIGHT. THE SURFACE
REFLECTION IS RATHER WEAK AS IT REMAINS AN OPEN TROUGH TIED TO A
CLOSED CIRCULATION FURTHER NW OVER MANITOBA. MID LEVEL DRY SLOT IS
WORKING ITS WAY ACROSS SOUTHERN MI PUSHING THE DEEPER MOISTURE FROM
THIS MORNING OFF TO THE EAST. BREAKS IN THE CLOUD COVER HAS ALLOWED
SOME DIURNAL HEATING OVER FAR SW LOWER MI. TEMPS ARE PUSHING THE
UPPER 60S IN THOSE LOCATIONS. IN ADDITION...S/SW WINDS GUSTING UP TO
25 KNOTS HAS BROUGHT IN ABUNDANT SFC MOISTURE WITH DEWPOINTS IN THE
MID 50S ACROSS ALL OF SOUTHERN MI. THE EXCEPTION IS OVER THE EXTREME
EASTERN PORTIONS OF THE CWA WHERE A SE COMPONENT IS STILL HANGING
ON. THIS HELD THE SUB 1000FT CLOUDS FIRMLY UNTIL ABOUT THE LAST WHEN
THEY STARTED TO SCATTER OUT. THUNDERSTORM COMPLEX FROM EARLIER WEST
OF CHICAGO HAS TRACKED NORTH INTO WESTERN MI NORTH OF MUSKEGON. WITH
WIND SHEAR NEARLY UNIDIRECTIONAL FROM THE SW...COMPLEX IS STRUGGLING
TO MAKE ANY EASTWARD PROGRESS.
FOR TONIGHT...THREAT FOR SEVERE WEATHER LATE THIS EVENING REMAINS
CONDITIONAL ON AMOUNT OF SURFACE BASED INSTABILITY WE CAN ACHIEVE.
THERE LOOKS TO BE PLENTY OF WIDESPREAD LIFT SUPPORTING STORM
DEVELOPMENT WITH THE UPPER LEVEL COLD POOL IN PLACE AND THE ENTRANCE
REGION OF A JET STREAK OVER THE REGION. THERE ARE FAVORABLE WIND
PARAMETERS ASSOCIATED WITH THE FRONTAL PASSAGE. BULK SHEAR VALUES
AROUND 40-50 KNOTS...BOTH 0-3KM AND 0-1 KN HELICITY IN EXCESS OF 300
M2/S2. LOOKING AT CAPE VALUES...THOUGH NAM MUCAPE IS ADVERTISED AT
800J/KG...NEITHER THE NAM OR RUC FIND MUCH IN THE WAY OF SFC BASED
CAPE WITH VALUES UP TO 100-200 J/KG WITH HIGHEST AMOUNTS FOR THE
WESTERN PART OF THE CWA. HIRES MODELS SHOW SOME ISOLATED CELLS
TRYING TO GO UP IN ADVANCE OF THE COLD FRONT WITH THE BULK OF THE
SHOWERS/STORMS OCCURRING THE FRONT ITSELF MAINLY FROM
23Z-05Z...WORKING SOUTH FROM MBS TO DTW. LOOKS LIKE SMALL HAIL AND
WIND GUSTS TO 50MPH WILL BE THE MOST LIKELY RESULTS OF THESE
STORMS...ALTHOUGH IF WE CAN GET MORE SFC BASED INSTABILITY SEVERE
STORMS WILL NOT BE OUT OF THE QUESTION.
&&
.LONG TERM...
THE WARM PATTERN LOOKS TO STICKING AROUND FOR THE EXTENDED
PERIOD...WITH POTENTIAL PSEUDO OMEGA BLOCKING PATTERN SETTING UP
LATE IN THE WEEKEND/EARLY NEXT WEEK.
CONSOLIDATING UPPER WAVES TAKES PLACE OVER ONTARIO TOMORROW...WITH
SHORTWAVE TROUGH AXIS AND SLIGHT HEIGHT FALLS TAKING PLACE LATE IN
THE DAY. STILL...WITH FAVORABLE WESTERLY WINDS AND THE TEMP GRADIENT
ADVERTISED (925 MB TEMPS OF 8 C NORTH TO 11 C SOUTH)...LOOKING AT
UPPER 50S NORTH TO MID 60S SOUTH WITH PLENTY OF SUNSHINE.
SURFACE RIDGE AXIS ARRIVING TOMORROW EVENING SHOULD ALLOW FOR
FAVORABLE RADIATING CONDITIONS...BUT WE ALREADY HAVE MODEST LOW
LEVEL WARM ADVECTION RETURNING BY SUNRISE WEDNESDAY. GUIDANCE TEMPS
IN THE 30S APPEAR REASONABLE.
A DRY WARM FRONT EXPECTED TO PUSH NORTH OF SOUTHERN LOWER MICHIGAN
DURING WEDNESDAY AS UPPER LEVEL RIDGE BUILDS OVERHEAD...PUSHING
TEMPS TO 70 DEGREES OR BETTER BASED ON FORECASTED 925 MB TEMPS OF
+15 TO +16 C. THE EXCEPTION WILL BE ACROSS THUMB REGION WHERE FRONT
WILL PROBABLY NOT CLEAR BY DAYS END...WITH BACKED SOUTHEAST FLOW
COMING OFF COOL WATERS OF SOUTHERN LAKE HURON.
DEEP SOUTHWEST FLOW OVER THE CENTRAL CONUS THURSDAY/FRIDAY...WITH
POTENTIAL UPPER LEVEL PV FILAMENT ROLLING THROUGH ON THURSDAY...PER
12Z GFS...TO TRIGGER SHOWERS AND POSSIBLE THUNDERSTORMS...AS
RESPECTABLE SURGE IN MOISTURE TAKES PLACE. CLOUDS AND CONVECTIVE
ACTIVITY COULD BE ENOUGH TO KEEP TEMPS STUCK IN THE UPPER 60S
DESPITE THE VERY MILD START TO THE DAY. THE 12Z EUROPEAN OFFERS A
DIFFERENT SOLUTION AND SUGGESTS THE SHORTWAVE/TROUGH COMING OUT OF
THE NORTHERN PLAINS WILL BE STRONGER...MOVING THROUGH ON FRIDAY.
THIS WOULD TRANSLATE TO A WARM DAY ON THURSDAY (70S) AND BETTER
CHANCE OF SHOWERS ON FRIDAY. THE CANADIAN IS MORE IN LINE WITH THE
GFS...SO WILL NOT MAKE A BIG PUSH TO EXTENDED GRIDS MUCH.
MEDIUM RANGE MODELS STILL FORECASTING AMPLIFIED PATTERN FOR THE
WEEKEND INTO EARLY NEXT WEEK...WITH LONGWAVE TROUGH OUT WEST AND
UPPER LEVEL RIDGE BUILDING NEAR THE GREAT LAKES REGION. ALMOST
SUMMER LIKE RIDGE (582-586 DAM AT 500 MB)...AND TEMPS APPROACHING 80
DEGREES IS NOT OUT OF THE QUESTION AS WE GET TO TUESDAY AS 1000-500
MB THICKNESSES CLIMB TOWARD 564 DAM. LAKE BREEZES WOULD LIKELY BE
COMING INTO PLAY HOWEVER AND WILL NEED TO REMAIN MORE CONSERVATIVE
THAT FAR OUT...ESPECIALLY WITH THE EUROPEAN PROFILES A BIT COOLER.
&&
.MARINE...
OUTSIDE OF A FEW POSSIBLE THUNDERSTORMS THIS EVENING...MARINE
CONDITIONS ARE EXPECTED TO REMAIN QUIET. UNUSUALLY MILD AIR IN PLACE
FOR EARLY MARCH WILL LEAD TO STABLE STABLE LOW LEVEL PROFILES OVER
THE GREAT LAKES. THIS WILL MINIMIZE THE GUST POTENTIAL TO AROUND 20
KNOTS OVER THE NEXT SEVERAL DAYS. THOSE STRONGER WINDS LOOKED TO BE
CONFINED TO THE NORTH THIRD OF LAKE HURON TOMORROW...AS CHANNELING
OCCURS WITH WESTERLY FLOW. THE NEXT CHANCE OF THUNDERSTORMS RETURNS
ON THURSDAY.
&&
.AVIATION...ISSUED 133 PM EDT MON MAR 12 2012
//DISCUSSION...
FIRST WAVE OF RAIN HAS EXITED THE AREA AS THE DRY SLOT WORKS INTO
SOUTHERN MI. THIS WILL MAKE FOR MVFR CIGS THROUGH THE
AFTERNOON. ANY LINGERING IFR CIGS BELOW 1000FT WILL LIFT RAPIDLY
AFTER ISSUANCE. ATTENTION TURNS TO LATER THIS EVENING WHEN A COLD
FRONT WILL SWEEP THROUGH SE MI BRINGING ANOTHER ROUND OF SHOWERS.
GENERAL TIMING WILL BE BETWEEN 00Z (MBS) TO 05Z (DTW/DET). POTENTIAL
EXISTS FOR SOME THUNDERSTORMS TO DEVELOP BUT COVERAGE MAY BE TOO
LIMITED TO INCLUDE IN THE TAFS AT THIS TIME. TIMING OF THE FRONT
WOULD SUGGEST MBS/FNT HAVE THE BEST CHANCE FOR THUNDER BEING ABLE TO
TAP INTO DIURNAL INSTABILITY. DRY AIR WILL ADVECT INTO THE STATE ON
TUESDAY LEADING TO CLEAR SKIES BY LATE MORNING.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FEET THROUGH TONIGHT.
* LOW CONFIDENCE IN THUNDERSTORM POTENTIAL THIS EVENING.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...DRK
LONG TERM....SF
MARINE.......SF
AVIATION.....DRK
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
148 PM EDT MON MAR 12 2012
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 411 AM EDT MON MAR 12 2012
WV IMAGERY AND RUC ANALYSIS SHOWING UPPER LOW SPINNING OVER ERN
NEB. BROAD AREA OF LIGHT/MOD RAIN ON RADAR/OBS COVERING MUCH OF WI
AT THIS TIME AND PUSHING N. THIS WILL BE THE INITIAL FEATURE OF
CONCERN FOR THE FIRST PART OF THE MORNING.
THIS PCPN IS LOCATED ALONG AN AREA OF H925-700 WAA/FGEN...ALONG WITH
290-300K ISENTROPIC ASCENT. IN ADDITION...NOSE OF UPPER JET ROTATING
AROUND THE BASE OF THE UPPER LOW IS FOCUSED OVER WI AND WITH THE
AREA OF PCPN. HAVE DEFINITE POPS PUSHING N ACROSS THE CWA AS THIS
AREA OF RAIN PUSHES N...BUT THERE IS CONCERN ON WHETHER THIS WILL
HOLD TOGETHER. MODELS CONSISTENT ON THIS AREA OF FORCING DIMINISHING
AND SHEARING OUT AS IT PUSHES N INTO THE CWA EARLY THIS MORNING AND
ENCOUNTERS EXISTING DRY AIR. HIRES MODELS...INCLUDING
RUC/HRRR...HAVE BEEN HANDLING THE COVERAGE OF THE RAIN WELL THIS
MORNING AND ALSO SHOW THE PCPN DIMINISHING AS IT MOVES OVER THE NRN
HALF OF THE CWA. PCPN MAY ACTUALLY END FOR A PERIOD OF TIME OVER
PORTIONS OF THE SW CWA SHORTLY AFTER MORNING DRIVE TIME. EXPECT LOW
CLOUDS TO REMAIN IN PLACE BEHIND THIS INITIAL SURGE OF RAIN...AS DRY
AIR ABOVE H850 ROTATES THROUGH. SHOULD ALSO SEE SOME FOG DEVELOP
THROUGH THE MORNING...ESPECIALLY FOR AREAS FAVORED BY UPSLOPE SE
FLOW...INCLUDING NCNTRL UPPER MI AND THE KEWEENAW.
AFTER A BRIEF REPRIEVE BEHIND THIS INITIAL BAND OF RAIN...SECONDARY
SURGE LOOKS TO ARRIVE TOWARDS MID DAY AND CONTINUE INTO THE AFTN.
THIS IS ASSOCIATED WITH THE UPPER LOW AND SFC TROUGH PUSHING NE
INTO THE CWA. NOSE OF THE UPPER JET WILL BE FOCUSED OVER LOWER MI
AT THIS TIME...BUT FORCING FROM THE UPPER LOW AND ASSOCIATED HEIGHT
FALLS SHOULD BE SUFFICIENT TO REDEVELOP SCT/NUMEROUS SHOWERS THAT
MOVE FROM SW TO NE ACROSS THE CWA. COULD EVEN HAVE A FEW RUMBLES OF
THUNDER OVER PORTIONS OF THE SRN HALF OF THE CWA THIS AFTN WITH ANY
OF THE STRONGER SHOWERS. WITH THE UPPER LOW AND STRONG HEIGHT FALLS
MOVING THROUGH THIS AFTN...MID LVL LAPSE RATES INCREASE AND CREATES
POCKETS OF WEAK INSTABILITY. HAVE EXPANDED THE PREVIOUS ISOLATED
THUNDER MENTION SLIGHTLY BASED OFF LATEST TRENDS. AS WINDS TURN TO
THE SW IN THE AFTN...EXPECT FOG TO BECOME MORE PATCHY...AS MODELS
INDICATE A LITTLE DEEPER MIXING. DELAYED THE DIMINISHING FOG A
LITTLE FARTHER INTO THE AFTN. CONTINUED TO LINGER THE FOG INTO THE
EVENING OVER THE E WHERE THE RELATIVELY WARM/MOIST AIR WILL BE
FLOWING OFF LK MI.
AS THE UPPER LOW MOVES OVER LK SUPERIOR LATE THIS AFTN AND
EVENING...THIRD WAVE OF RAIN WILL AFFECT MAINLY THE WRN HALF OF THE
CWA. THIS IS ASSOCIATED WITH THE WRAP AROUND MOISTURE AND WEAK
290-305K ISENTROPIC ASCENT. THIS SHOULD CONTINUE THROUGH MUCH OF THE
EVENING HOURS OVER THE W HALF...AS THE BACK EDGE OF THE PCPN SLIDES
FROM MN AND THROUGH THE AREA. WITH THE MOISTURE AND PCPN CLOSELY
TIED WITH THE UPPER LOW...EXPECT A QUICK DIMINISHING TREND TO
POPS/SKY AFTER MIDNIGHT TONIGHT AS THE LOW MOVES INTO ONTARIO.
OVERALL...TRYING TO TIME THESE FEATURES IS EXTREMELY
DIFFICULT...ESPECIALLY WITH THE SEVERAL PERIODS OF RAIN. HAVE OPTED
TO GO WITH A SHOWERY WORDING INSTEAD OF STRATIFORM DUE TO THESE
PERIODS.
TUES...UPPER LOW THAT PASSED THROUGH THE AREA TODAY AND THIS EVENING
WILL PHASE WITH NRN STREAM TROUGH JUST TO THE N OF LK SUPERIOR ON
TUES. THIS WILL LEAD TO NW FLOW ALOFT ON TUES...BUT TROUGH IS
QUICKLY SHIFTING EAST. SOME DIFFERENCES IN HOW FAR S THE PHASING
OCCURS...WHICH COULD LEAD TO SOME LINGERING CLOUDS OVER THE KEWEENAW
AND FAR ERN UPPER MI. 18Z/00Z GFS WAS MUCH FARTHER S THAN OTHER
MODELS...WHICH ACTUALLY HOLDS PCPN INTO THE MORNING HOURS OVER FAR
ERN UPPER MI DUE TO THE DEEPER PHASING. WILL KEEP THE CLOUDS MAINLY
OVER NE LAKE SUPERIOR TO ACCOUNT FOR THIS UNCERTAINTY.
DECENT SPREAD IN GUIDANCE FOR HIGHS DUE TO THE DIFFERENCES IN
HANDLING THE PHASING OF THE UPPER THROUGH. MIXING TO H875-850
/AROUND 2C/ YIELDS HIGHS IN THE MID 50S...SO HAVE ADJUSTED EXISTING
HIGHS DOWN A TOUCH. WITH MAINLY NW FLOW...HAVE KEPT TEMPS NEAR LK
SUPERIOR A LITTLE COOLER. DEWPOINT VALUES WILL BE THE MAIN CONCERN
FOR TUES AFTN. DROPPED VALUES A GOOD 7-10 DEGREES OVER THE WRN
HALF OF THE CWA...WITH MODELS CONSISTENTLY SHOWING DECENT MIXING
INTO DRY AIR ALOFT. SOME OF OUR LOCAL MIXED TD TOOLS ACTUALLY GIVE
VALUES IN THE SINGLE DIGITS ABOVE ZERO...WHICH DOESN/T SEEM TOO
UNREASONABLE. STRAIGHT MODEL MIXED TD VALUES ARE IN THE LOWER
TEENS...SO HAVE TRENDED TOWARDS THAT WITH VALUES IN THE UPPER
TEENS. FORTUNATELY...THERE IS STILL A DECENT SNOW PACK...OTHERWISE
THERE COULD BE FIRE WX CONCERNS WITH GUSTY NW WINDS AND RH VALUES
FALLING INTO THE LOW 20S.
TUES NIGHT...WITH UPPER TROUGH CONTINUING E AND UPPER RIDGE
REBUILDING OVER THE NRN PLAINS...EXPECT DRY WX AND MOSTLY CLEAR
SKIES. SFC RIDGE MOVING ACROSS THE AREA WILL LEAD TO LIGHT WINDS
AND HAVE DROPPED TEMPS A FEW DEGREES. COULD SEE TEMPS FALL A LITTLE
MORE THAN EXPECTED OVER THE ERN CWA...DUE TO LIGHTER WINDS AND DRY
AIR ALOFT PRODUCING PWATS AROUND 70 PERCENT OF NORMAL. HAVE COOLED
THE TRADITIONAL COLD SPOTS SOME OVER THE ERN CWA TO BELOW FREEZING
VALUES. FINALLY...H850 WAA COULD LEAD TO A FEW CLOUDS DEVELOPING
OVER THE WRN LK AND WRN UPPER MI AFTER MIDNIGHT...BUT LIMITED
MOISTURE HAS CONFIDENCE LOW.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 411 AM EDT MON MAR 12 2012
WED...THE UPR RDG OVER THE GRT LKS WL MOVE SLOWLY TO THE E...BUT ITS
EWD PROGRESS WL BE SLOWED BY CUTOFF LO OVER NEW ENGLAND. AS A FAIRLY
STRONG DISTURBANCE MOVES INTO CNTRL CAN...ITS ATTENDANT TROF WL
APRCH THE UPR LKS BY LATE IN THE DAY. THE NAM IS THE FASTEST MOVING
THIS TROF ACRS THE CWA ON WED...BUT PREFER THE CONSENSUS OF THE
SLOWER MODELS GIVEN THE BLOCKING CUTOFF IN NEW ENGLAND. THESE MODELS
HINT THE TROF WL REACH THE W ONLY LATE IN THE DAY. WITH THE DRYNESS
OF THE ANTECEDENT AIRMASS AND A LACK OF ANY SGNFT UPR FORCING SO FAR
S OF THE DISTURBANCE MOVING THRU CNTRL CAN...OPTED TO RETAIN GOING
DRY FCST. WITH H85 TEMPS PEAKING ARND 10C...EXPECT ANOTHER DAY OF
WELL ABV NORMAL TEMPS...EVEN IF THE MORE PESSIMISTIC GFS IS CORRECT
ON SHOWING ENUF LLVL MSTR ARRIVING TO SUPPORT SC DEVELOPMENT IN THE
SW FLOW AHEAD OF THE INCOMING TROF. MIXING TO JUST H875 ON GFS FCST
SDNGS WOULD YIELD HI TEMPS APRCHG 70 AWAY FM THE MODIFIYING
INFLUENCE OF LK MI WITH LLVL SLY FLOW...ESPECIALLY IN THE DOWNSLOPE
AREAS W OF MQT. SUSPECT AT LEAST SOME PLACES OVER THE W HALF MAY SEE
DAILY RECORD HI TEMPS.
WED NGT...AS THE SFC TROF/PACIFIC TYPE COLD FNT MOVES E ACRS THE
CWA...THE 00Z GFS AND ESPECIALLY THE CNDN MODELS ARE MOST AGGRESSIVE
AT GENERATING SOME PCPN OVER MAINLY THE SE ZNS UNDER AREA OF STEEPER
H7-5 LAPSE RATES UP TO 7.5-8.0C/KM AND SHOWALTER INDEX AS LO AS -2
TO -4C. THE CNDN INSTABILITY IS GREATER AS THIS MODEL SHOWS A
STRONGER SHRTWV MOVING ENEWD IN THE WSW FLOW ALF. ALTHOUGH THE TIME
OF DAY WOULD NOT BE CONDUCIVE TO TS...OPTED TO INCLUDE SCHC TS OVER
THE SE ZNS CONSIDERING THE ANOMALOUS LLVL WARMTH OF THE ANTECEDENT
AIRMASS/FCST STABILITY INDICES. DRIER AND SOMEWHAT COOLER AIR WL
ARRIVE OVER ESPECIALLY THE W IN THE WAKE OF THE COLD FROPA AS WEAK
HI PRES MOVES TO THE MN ARROWHEAD BY 12Z THU.
EXTENDED...THE STEADY SLY FLOW BTWN WRN TROF/ERN RDG WL PERSIST THRU
THE WEEKEND WITH NEAR UNPRECEDENTED WARMTH POSSIBLE FRI THRU SUN IN
THE PRESENCE OF H85 TEMPS NOT FAR FM 10-12C. THE THU-FRI PERIOD
SHOULD BE DRY WITH HI PRES RDG OVER THE AREA...BUT THERE WL BE A CHC
OF SHRA OVER THE WEEKEND AS HI PRES SHIFTS TO THE E. LACK OF
CONSISTENCY ON SHRTWV PRESENCE/TIMING SUGS NO MORE THAN CHC POPS ARE
WARRANTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 147 PM EDT MON MAR 12 2012
COMPLEX AVIATION FORECAST THIS AFTN AS MID LEVEL LOW CURRENTLY OVER
SE MN/SW WI MOVES NORTHEAST. DENSE FOG/VLIFR CONDITIONS HAVE SETTLED
INTO KCMX/KSAW UNDER LOCALLY UPSLOPING WINDS. WITH DOWNSLOPING WINDS
AT KIWD...CONDITIONS HAVE BEEN MVFR AND THAT SHOULD CONTINUE THIS
AFTN. AS NEXT ROUND OF SCT SHRA ARRIVES ALONG WITH SFC TROF...EXPECT
CONDITIONS TO IMPROVE TO MVFR AT KCMX/KSAW BY LATE AFTN. WIND SHIFT
TO SW WILL ALSO HELP IMPROVE CONDITIONS. AS THE LOW MOVES NE
OVERNIGHT...EXPECT A FAIRLY QUICK TRANSITION TO CLEAR SKIES UNDER
STRONG DRYING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 AM EDT MON MAR 12 2012
UPPER LEVEL DISTURBANCE AND SURFACE TROUGH WILL SLIDE NE ACROSS
LAKE SUPERIOR THIS AFTERNOON AND TONIGHT. EXPECT SSE WINDS TO
MAINLY STAY BELOW 20KTS...BUT THERE COULD BE A FEW GUSTS TO 25KTS
OVER THE NRN LK. AS WARM/MOIST AIR MOVES OVER LAKE SUPERIOR
TODAY...SHOULD SEE AREAS OF FOG DEVELOP LATE THIS MORNING AND
CONTINUE INTO THIS EVENING. BEHIND THE SURFACE TROUGH...EXPECT
WINDS TO INCREASE OUT OF THE WEST AFTER MIDNIGHT AND CONTINUE INTO
TUESDAY. WARM AIR ABOVE THE SURFACE WILL LIKELY KEEP THE MARINE
LAYER IN PLACE AND LIMIT THE VERY STRONG WINDS ALOFT FROM
REACHING THE SURFACE. AT THIS TIME...ONLY HAVE GUSTS REACHING
30KTS. AFTER TUESDAY...WINDS WILL REMAIN UNDER 25KTS WITH A
RELATIVELY WEAK PRESSURE GRADIENT IN PLACE.
&&
.HYDROLOGY...
ISSUED AT 411 AM EDT MON MAR 12 2012
NEAR RECORD TO RECORD SETTING TEMPS YESTERDAY HAS HELPED RIPEN THE
SNOW PACK. RAIN TODAY AND FOR PARTS OF TONIGHT WILL PROVIDE
ADDITIONAL MOISTURE TO THE AREA. EXPECT THE BULK OF THE
RAIN TO FALL DURING THE MORNING TO EARLY AFTERNOON HOURS...WITH
ACCUMULATIONS OF AROUND 0.25 TO 0.40IN. THE RAIN...COMBINED
WITH DEWPOINTS RISING INTO THE 40S...WILL HELP TO QUICKEN
SNOWMELT. AS OF THIS MORNING...THERE HAS BEEN ONLY LIMITED
RESPONSES ON THE LARGER RIVERS.
THE RAIN AND SNOW MELT TODAY...COMBINED WITH ABOVE NORMAL
TEMPERATURES THROUGH NEXT WEEKEND WILL LEAD TO A INCREASE IN
RIVER AND STREAM LEVELS OVER THE NEXT SEVERAL DAYS. EXPECT SOME OF
THE RIVERS ACROSS THE AREA TO EXCEED THEIR BANKS BY THE END OF THIS
WEEK. PERSONS LIVING NEAR RIVERS AND STREAMS SHOULD
MONITOR THE LATEST RIVER CONDITIONS AND USE CAUTION IF WALKING
ALONG RIVER BANKS...ESPECIALLY THE CHOCOLAY RIVER...TRAP ROCK
RIVER...AND THE STURGEON RIVER IN WESTERN UPPER MICHIGAN.
ICE JAM WISE...NOT MUCH ICE HAS BEEN NOTED BY OBSERVERS ON THE
FASTER FLOWING RIVERS OVER NRN UPPER MI. BUT THE FORD RIVER...BOTH
AT HYDE AND THE MOUTH AT LK MI...STILL HAS GOOD ICE COVER THAT
LEADS TO SOME CONCERN FOR ICE JAM POTENTIAL WITH THE FASTER RUNOFF.
ALTHOUGH LIMITED SNOW WAS NOTED NEAR LK MI...THERE IS STILL 4-9IN
OF SNOW ...AND NOHRSC ESTIMATED AROUND 1.25IN OF LIQUID...TOWARDS
THE HEADWATERS THAT WILL BE MELTED OVER THE COMING DAYS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ221-248-
250.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...ROLFSON
MARINE...SRF
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
717 AM EDT MON MAR 12 2012
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 411 AM EDT MON MAR 12 2012
WV IMAGERY AND RUC ANALYSIS SHOWING UPPER LOW SPINNING OVER ERN
NEB. BROAD AREA OF LIGHT/MOD RAIN ON RADAR/OBS COVERING MUCH OF WI
AT THIS TIME AND PUSHING N. THIS WILL BE THE INITIAL FEATURE OF
CONCERN FOR THE FIRST PART OF THE MORNING.
THIS PCPN IS LOCATED ALONG AN AREA OF H925-700 WAA/FGEN...ALONG WITH
290-300K ISENTROPIC ASCENT. IN ADDITION...NOSE OF UPPER JET ROTATING
AROUND THE BASE OF THE UPPER LOW IS FOCUSED OVER WI AND WITH THE
AREA OF PCPN. HAVE DEFINITE POPS PUSHING N ACROSS THE CWA AS THIS
AREA OF RAIN PUSHES N...BUT THERE IS CONCERN ON WHETHER THIS WILL
HOLD TOGETHER. MODELS CONSISTENT ON THIS AREA OF FORCING DIMINISHING
AND SHEARING OUT AS IT PUSHES N INTO THE CWA EARLY THIS MORNING AND
ENCOUNTERS EXISTING DRY AIR. HIRES MODELS...INCLUDING
RUC/HRRR...HAVE BEEN HANDLING THE COVERAGE OF THE RAIN WELL THIS
MORNING AND ALSO SHOW THE PCPN DIMINISHING AS IT MOVES OVER THE NRN
HALF OF THE CWA. PCPN MAY ACTUALLY END FOR A PERIOD OF TIME OVER
PORTIONS OF THE SW CWA SHORTLY AFTER MORNING DRIVE TIME. EXPECT LOW
CLOUDS TO REMAIN IN PLACE BEHIND THIS INITIAL SURGE OF RAIN...AS DRY
AIR ABOVE H850 ROTATES THROUGH. SHOULD ALSO SEE SOME FOG DEVELOP
THROUGH THE MORNING...ESPECIALLY FOR AREAS FAVORED BY UPSLOPE SE
FLOW...INCLUDING NCNTRL UPPER MI AND THE KEWEENAW.
AFTER A BRIEF REPRIEVE BEHIND THIS INITIAL BAND OF RAIN...SECONDARY
SURGE LOOKS TO ARRIVE TOWARDS MID DAY AND CONTINUE INTO THE AFTN.
THIS IS ASSOCIATED WITH THE UPPER LOW AND SFC TROUGH PUSHING NE
INTO THE CWA. NOSE OF THE UPPER JET WILL BE FOCUSED OVER LOWER MI
AT THIS TIME...BUT FORCING FROM THE UPPER LOW AND ASSOCIATED HEIGHT
FALLS SHOULD BE SUFFICIENT TO REDEVELOP SCT/NUMEROUS SHOWERS THAT
MOVE FROM SW TO NE ACROSS THE CWA. COULD EVEN HAVE A FEW RUMBLES OF
THUNDER OVER PORTIONS OF THE SRN HALF OF THE CWA THIS AFTN WITH ANY
OF THE STRONGER SHOWERS. WITH THE UPPER LOW AND STRONG HEIGHT FALLS
MOVING THROUGH THIS AFTN...MID LVL LAPSE RATES INCREASE AND CREATES
POCKETS OF WEAK INSTABILITY. HAVE EXPANDED THE PREVIOUS ISOLATED
THUNDER MENTION SLIGHTLY BASED OFF LATEST TRENDS. AS WINDS TURN TO
THE SW IN THE AFTN...EXPECT FOG TO BECOME MORE PATCHY...AS MODELS
INDICATE A LITTLE DEEPER MIXING. DELAYED THE DIMINISHING FOG A
LITTLE FARTHER INTO THE AFTN. CONTINUED TO LINGER THE FOG INTO THE
EVENING OVER THE E WHERE THE RELATIVELY WARM/MOIST AIR WILL BE
FLOWING OFF LK MI.
AS THE UPPER LOW MOVES OVER LK SUPERIOR LATE THIS AFTN AND
EVENING...THIRD WAVE OF RAIN WILL AFFECT MAINLY THE WRN HALF OF THE
CWA. THIS IS ASSOCIATED WITH THE WRAP AROUND MOISTURE AND WEAK
290-305K ISENTROPIC ASCENT. THIS SHOULD CONTINUE THROUGH MUCH OF THE
EVENING HOURS OVER THE W HALF...AS THE BACK EDGE OF THE PCPN SLIDES
FROM MN AND THROUGH THE AREA. WITH THE MOISTURE AND PCPN CLOSELY
TIED WITH THE UPPER LOW...EXPECT A QUICK DIMINISHING TREND TO
POPS/SKY AFTER MIDNIGHT TONIGHT AS THE LOW MOVES INTO ONTARIO.
OVERALL...TRYING TO TIME THESE FEATURES IS EXTREMELY
DIFFICULT...ESPECIALLY WITH THE SEVERAL PERIODS OF RAIN. HAVE OPTED
TO GO WITH A SHOWERY WORDING INSTEAD OF STRATIFORM DUE TO THESE
PERIODS.
TUES...UPPER LOW THAT PASSED THROUGH THE AREA TODAY AND THIS EVENING
WILL PHASE WITH NRN STREAM TROUGH JUST TO THE N OF LK SUPERIOR ON
TUES. THIS WILL LEAD TO NW FLOW ALOFT ON TUES...BUT TROUGH IS
QUICKLY SHIFTING EAST. SOME DIFFERENCES IN HOW FAR S THE PHASING
OCCURS...WHICH COULD LEAD TO SOME LINGERING CLOUDS OVER THE KEWEENAW
AND FAR ERN UPPER MI. 18Z/00Z GFS WAS MUCH FARTHER S THAN OTHER
MODELS...WHICH ACTUALLY HOLDS PCPN INTO THE MORNING HOURS OVER FAR
ERN UPPER MI DUE TO THE DEEPER PHASING. WILL KEEP THE CLOUDS MAINLY
OVER NE LAKE SUPERIOR TO ACCOUNT FOR THIS UNCERTAINTY.
DECENT SPREAD IN GUIDANCE FOR HIGHS DUE TO THE DIFFERENCES IN
HANDLING THE PHASING OF THE UPPER THROUGH. MIXING TO H875-850
/AROUND 2C/ YIELDS HIGHS IN THE MID 50S...SO HAVE ADJUSTED EXISTING
HIGHS DOWN A TOUCH. WITH MAINLY NW FLOW...HAVE KEPT TEMPS NEAR LK
SUPERIOR A LITTLE COOLER. DEWPOINT VALUES WILL BE THE MAIN CONCERN
FOR TUES AFTN. DROPPED VALUES A GOOD 7-10 DEGREES OVER THE WRN
HALF OF THE CWA...WITH MODELS CONSISTENTLY SHOWING DECENT MIXING
INTO DRY AIR ALOFT. SOME OF OUR LOCAL MIXED TD TOOLS ACTUALLY GIVE
VALUES IN THE SINGLE DIGITS ABOVE ZERO...WHICH DOESN/T SEEM TOO
UNREASONABLE. STRAIGHT MODEL MIXED TD VALUES ARE IN THE LOWER
TEENS...SO HAVE TRENDED TOWARDS THAT WITH VALUES IN THE UPPER
TEENS. FORTUNATELY...THERE IS STILL A DECENT SNOW PACK...OTHERWISE
THERE COULD BE FIRE WX CONCERNS WITH GUSTY NW WINDS AND RH VALUES
FALLING INTO THE LOW 20S.
TUES NIGHT...WITH UPPER TROUGH CONTINUING E AND UPPER RIDGE
REBUILDING OVER THE NRN PLAINS...EXPECT DRY WX AND MOSTLY CLEAR
SKIES. SFC RIDGE MOVING ACROSS THE AREA WILL LEAD TO LIGHT WINDS
AND HAVE DROPPED TEMPS A FEW DEGREES. COULD SEE TEMPS FALL A LITTLE
MORE THAN EXPECTED OVER THE ERN CWA...DUE TO LIGHTER WINDS AND DRY
AIR ALOFT PRODUCING PWATS AROUND 70 PERCENT OF NORMAL. HAVE COOLED
THE TRADITIONAL COLD SPOTS SOME OVER THE ERN CWA TO BELOW FREEZING
VALUES. FINALLY...H850 WAA COULD LEAD TO A FEW CLOUDS DEVELOPING
OVER THE WRN LK AND WRN UPPER MI AFTER MIDNIGHT...BUT LIMITED
MOISTURE HAS CONFIDENCE LOW.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 411 AM EDT MON MAR 12 2012
WED...THE UPR RDG OVER THE GRT LKS WL MOVE SLOWLY TO THE E...BUT ITS
EWD PROGRESS WL BE SLOWED BY CUTOFF LO OVER NEW ENGLAND. AS A FAIRLY
STRONG DISTURBANCE MOVES INTO CNTRL CAN...ITS ATTENDANT TROF WL
APRCH THE UPR LKS BY LATE IN THE DAY. THE NAM IS THE FASTEST MOVING
THIS TROF ACRS THE CWA ON WED...BUT PREFER THE CONSENSUS OF THE
SLOWER MODELS GIVEN THE BLOCKING CUTOFF IN NEW ENGLAND. THESE MODELS
HINT THE TROF WL REACH THE W ONLY LATE IN THE DAY. WITH THE DRYNESS
OF THE ANTECEDENT AIRMASS AND A LACK OF ANY SGNFT UPR FORCING SO FAR
S OF THE DISTURBANCE MOVING THRU CNTRL CAN...OPTED TO RETAIN GOING
DRY FCST. WITH H85 TEMPS PEAKING ARND 10C...EXPECT ANOTHER DAY OF
WELL ABV NORMAL TEMPS...EVEN IF THE MORE PESSIMISTIC GFS IS CORRECT
ON SHOWING ENUF LLVL MSTR ARRIVING TO SUPPORT SC DEVELOPMENT IN THE
SW FLOW AHEAD OF THE INCOMING TROF. MIXING TO JUST H875 ON GFS FCST
SDNGS WOULD YIELD HI TEMPS APRCHG 70 AWAY FM THE MODIFIYING
INFLUENCE OF LK MI WITH LLVL SLY FLOW...ESPECIALLY IN THE DOWNSLOPE
AREAS W OF MQT. SUSPECT AT LEAST SOME PLACES OVER THE W HALF MAY SEE
DAILY RECORD HI TEMPS.
WED NGT...AS THE SFC TROF/PACIFIC TYPE COLD FNT MOVES E ACRS THE
CWA...THE 00Z GFS AND ESPECIALLY THE CNDN MODELS ARE MOST AGGRESSIVE
AT GENERATING SOME PCPN OVER MAINLY THE SE ZNS UNDER AREA OF STEEPER
H7-5 LAPSE RATES UP TO 7.5-8.0C/KM AND SHOWALTER INDEX AS LO AS -2
TO -4C. THE CNDN INSTABILITY IS GREATER AS THIS MODEL SHOWS A
STRONGER SHRTWV MOVING ENEWD IN THE WSW FLOW ALF. ALTHOUGH THE TIME
OF DAY WOULD NOT BE CONDUCIVE TO TS...OPTED TO INCLUDE SCHC TS OVER
THE SE ZNS CONSIDERING THE ANOMALOUS LLVL WARMTH OF THE ANTECEDENT
AIRMASS/FCST STABILITY INDICES. DRIER AND SOMEWHAT COOLER AIR WL
ARRIVE OVER ESPECIALLY THE W IN THE WAKE OF THE COLD FROPA AS WEAK
HI PRES MOVES TO THE MN ARROWHEAD BY 12Z THU.
EXTENDED...THE STEADY SLY FLOW BTWN WRN TROF/ERN RDG WL PERSIST THRU
THE WEEKEND WITH NEAR UNPRECEDENTED WARMTH POSSIBLE FRI THRU SUN IN
THE PRESENCE OF H85 TEMPS NOT FAR FM 10-12C. THE THU-FRI PERIOD
SHOULD BE DRY WITH HI PRES RDG OVER THE AREA...BUT THERE WL BE A CHC
OF SHRA OVER THE WEEKEND AS HI PRES SHIFTS TO THE E. LACK OF
CONSISTENCY ON SHRTWV PRESENCE/TIMING SUGS NO MORE THAN CHC POPS ARE
WARRANTED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 716 AM EDT MON MAR 12 2012
COMPLEX AVIATION FORECAST TODAY...AS AN UPPER LEVEL DISTURBANCE
LOCATED OVER NW IOWA AND SOUTHERN MN MOVES NORTHEAST ACROSS UPPER
MICHIGAN. THE FIRST WAVE OF -RA HAS QUICKLY MOVED IN THIS MORNING.
EXPECT THIS STEADIER RAIN TO END FROM S TO N OVER THE NEXT COUPLE
OF HOURS. THIS WILL LEAD TO MORE OFF/ON SHOWERS AT THE TAF
SITES...WITH CONCERNS FOR UPSLOPE FOG AT BOTH KCMX/KSAW. WITH THE
FAVORABLE SE WINDS AND INCREASING MOISTURE...EXPECT AIRFIELD LANDING
MINS TO BE REACHED FROM MID MORNING INTO MID AFTN. HAVE KEPT KIWD A
LITTLE HIGHER DUE TO UNFAVORABLE SE FLOW. EXPECT THE FOG TO DIMINISH
AS WINDS TURN SW THIS AFTN...BUT THIS WILL BRING THE SECOND PERIOD
OF SHOWERS. UPSTREAM OBS REINFORCE THE POTENTIAL FOR LOW MVFR AND
IFR CIGS TO REMAIN THROUGH THE EVENING WITH THESE SHOWERS. AS THE
LOW MOVES NE OVERNIGHT...EXPECT A QUICK TRANSITION TO CLEAR SKIES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 AM EDT MON MAR 12 2012
UPPER LEVEL DISTURBANCE AND SURFACE TROUGH WILL SLIDE NE ACROSS
LAKE SUPERIOR THIS AFTERNOON AND TONIGHT. EXPECT SSE WINDS TO
MAINLY STAY BELOW 20KTS...BUT THERE COULD BE A FEW GUSTS TO 25KTS
OVER THE NRN LK. AS WARM/MOIST AIR MOVES OVER LAKE SUPERIOR
TODAY...SHOULD SEE AREAS OF FOG DEVELOP LATE THIS MORNING AND
CONTINUE INTO THIS EVENING. BEHIND THE SURFACE TROUGH...EXPECT
WINDS TO INCREASE OUT OF THE WEST AFTER MIDNIGHT AND CONTINUE INTO
TUESDAY. WARM AIR ABOVE THE SURFACE WILL LIKELY KEEP THE MARINE
LAYER IN PLACE AND LIMIT THE VERY STRONG WINDS ALOFT FROM
REACHING THE SURFACE. AT THIS TIME...ONLY HAVE GUSTS REACHING
30KTS. AFTER TUESDAY...WINDS WILL REMAIN UNDER 25KTS WITH A
RELATIVELY WEAK PRESSURE GRADIENT IN PLACE.
&&
.HYDROLOGY...
ISSUED AT 411 AM EDT MON MAR 12 2012
NEAR RECORD TO RECORD SETTING TEMPS YESTERDAY HAS HELPED RIPEN THE
SNOW PACK. RAIN TODAY AND FOR PARTS OF TONIGHT WILL PROVIDE
ADDITIONAL MOISTURE TO THE AREA. EXPECT THE BULK OF THE
RAIN TO FALL DURING THE MORNING TO EARLY AFTERNOON HOURS...WITH
ACCUMULATIONS OF AROUND 0.25 TO 0.40IN. THE RAIN...COMBINED
WITH DEWPOINTS RISING INTO THE 40S...WILL HELP TO QUICKEN
SNOWMELT. AS OF THIS MORNING...THERE HAS BEEN ONLY LIMITED
RESPONSES ON THE LARGER RIVERS.
THE RAIN AND SNOW MELT TODAY...COMBINED WITH ABOVE NORMAL
TEMPERATURES THROUGH NEXT WEEKEND WILL LEAD TO A INCREASE IN
RIVER AND STREAM LEVELS OVER THE NEXT SEVERAL DAYS. EXPECT SOME OF
THE RIVERS ACROSS THE AREA TO EXCEED THEIR BANKS BY THE END OF THIS
WEEK. PERSONS LIVING NEAR RIVERS AND STREAMS SHOULD
MONITOR THE LATEST RIVER CONDITIONS AND USE CAUTION IF WALKING
ALONG RIVER BANKS...ESPECIALLY THE CHOCOLAY RIVER...TRAP ROCK
RIVER...AND THE STURGEON RIVER IN WESTERN UPPER MICHIGAN.
ICE JAM WISE...NOT MUCH ICE HAS BEEN NOTED BY OBSERVERS ON THE
FASTER FLOWING RIVERS OVER NRN UPPER MI. BUT THE FORD RIVER...BOTH
AT HYDE AND THE MOUTH AT LK MI...STILL HAS GOOD ICE COVER THAT
LEADS TO SOME CONCERN FOR ICE JAM POTENTIAL WITH THE FASTER RUNOFF.
ALTHOUGH LIMITED SNOW WAS NOTED NEAR LK MI...THERE IS STILL 4-9IN
OF SNOW ...AND NOHRSC ESTIMATED AROUND 1.25IN OF LIQUID...TOWARDS
THE HEADWATERS THAT WILL BE MELTED OVER THE COMING DAYS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...SRF
MARINE...SRF
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
414 AM EDT MON MAR 12 2012
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 411 AM EDT MON MAR 12 2012
WV IMAGERY AND RUC ANALYSIS SHOWING UPPER LOW SPINNING OVER ERN
NEB. BROAD AREA OF LIGHT/MOD RAIN ON RADAR/OBS COVERING MUCH OF WI
AT THIS TIME AND PUSHING N. THIS WILL BE THE INITIAL FEATURE OF
CONCERN FOR THE FIRST PART OF THE MORNING.
THIS PCPN IS LOCATED ALONG AN AREA OF H925-700 WAA/FGEN...ALONG WITH
290-300K ISENTROPIC ASCENT. IN ADDITION...NOSE OF UPPER JET ROTATING
AROUND THE BASE OF THE UPPER LOW IS FOCUSED OVER WI AND WITH THE
AREA OF PCPN. HAVE DEFINITE POPS PUSHING N ACROSS THE CWA AS THIS
AREA OF RAIN PUSHES N...BUT THERE IS CONCERN ON WHETHER THIS WILL
HOLD TOGETHER. MODELS CONSISTENT ON THIS AREA OF FORCING DIMINISHING
AND SHEARING OUT AS IT PUSHES N INTO THE CWA EARLY THIS MORNING AND
ENCOUNTERS EXISTING DRY AIR. HIRES MODELS...INCLUDING
RUC/HRRR...HAVE BEEN HANDLING THE COVERAGE OF THE RAIN WELL THIS
MORNING AND ALSO SHOW THE PCPN DIMINISHING AS IT MOVES OVER THE NRN
HALF OF THE CWA. PCPN MAY ACTUALLY END FOR A PERIOD OF TIME OVER
PORTIONS OF THE SW CWA SHORTLY AFTER MORNING DRIVE TIME. EXPECT LOW
CLOUDS TO REMAIN IN PLACE BEHIND THIS INITIAL SURGE OF RAIN...AS DRY
AIR ABOVE H850 ROTATES THROUGH. SHOULD ALSO SEE SOME FOG DEVELOP
THROUGH THE MORNING...ESPECIALLY FOR AREAS FAVORED BY UPSLOPE SE
FLOW...INCLUDING NCNTRL UPPER MI AND THE KEWEENAW.
AFTER A BRIEF REPRIEVE BEHIND THIS INITIAL BAND OF RAIN...SECONDARY
SURGE LOOKS TO ARRIVE TOWARDS MID DAY AND CONTINUE INTO THE AFTN.
THIS IS ASSOCIATED WITH THE UPPER LOW AND SFC TROUGH PUSHING NE
INTO THE CWA. NOSE OF THE UPPER JET WILL BE FOCUSED OVER LOWER MI
AT THIS TIME...BUT FORCING FROM THE UPPER LOW AND ASSOCIATED HEIGHT
FALLS SHOULD BE SUFFICIENT TO REDEVELOP SCT/NUMEROUS SHOWERS THAT
MOVE FROM SW TO NE ACROSS THE CWA. COULD EVEN HAVE A FEW RUMBLES OF
THUNDER OVER PORTIONS OF THE SRN HALF OF THE CWA THIS AFTN WITH ANY
OF THE STRONGER SHOWERS. WITH THE UPPER LOW AND STRONG HEIGHT FALLS
MOVING THROUGH THIS AFTN...MID LVL LAPSE RATES INCREASE AND CREATES
POCKETS OF WEAK INSTABILITY. HAVE EXPANDED THE PREVIOUS ISOLATED
THUNDER MENTION SLIGHTLY BASED OFF LATEST TRENDS. AS WINDS TURN TO
THE SW IN THE AFTN...EXPECT FOG TO BECOME MORE PATCHY...AS MODELS
INDICATE A LITTLE DEEPER MIXING. DELAYED THE DIMINISHING FOG A
LITTLE FARTHER INTO THE AFTN. CONTINUED TO LINGER THE FOG INTO THE
EVENING OVER THE E WHERE THE RELATIVELY WARM/MOIST AIR WILL BE
FLOWING OFF LK MI.
AS THE UPPER LOW MOVES OVER LK SUPERIOR LATE THIS AFTN AND
EVENING...THIRD WAVE OF RAIN WILL AFFECT MAINLY THE WRN HALF OF THE
CWA. THIS IS ASSOCIATED WITH THE WRAP AROUND MOISTURE AND WEAK
290-305K ISENTROPIC ASCENT. THIS SHOULD CONTINUE THROUGH MUCH OF THE
EVENING HOURS OVER THE W HALF...AS THE BACK EDGE OF THE PCPN SLIDES
FROM MN AND THROUGH THE AREA. WITH THE MOISTURE AND PCPN CLOSELY
TIED WITH THE UPPER LOW...EXPECT A QUICK DIMINISHING TREND TO
POPS/SKY AFTER MIDNIGHT TONIGHT AS THE LOW MOVES INTO ONTARIO.
OVERALL...TRYING TO TIME THESE FEATURES IS EXTREMELY
DIFFICULT...ESPECIALLY WITH THE SEVERAL PERIODS OF RAIN. HAVE OPTED
TO GO WITH A SHOWERY WORDING INSTEAD OF STRATIFORM DUE TO THESE
PERIODS.
TUES...UPPER LOW THAT PASSED THROUGH THE AREA TODAY AND THIS EVENING
WILL PHASE WITH NRN STREAM TROUGH JUST TO THE N OF LK SUPERIOR ON
TUES. THIS WILL LEAD TO NW FLOW ALOFT ON TUES...BUT TROUGH IS
QUICKLY SHIFTING EAST. SOME DIFFERENCES IN HOW FAR S THE PHASING
OCCURS...WHICH COULD LEAD TO SOME LINGERING CLOUDS OVER THE KEWEENAW
AND FAR ERN UPPER MI. 18Z/00Z GFS WAS MUCH FARTHER S THAN OTHER
MODELS...WHICH ACTUALLY HOLDS PCPN INTO THE MORNING HOURS OVER FAR
ERN UPPER MI DUE TO THE DEEPER PHASING. WILL KEEP THE CLOUDS MAINLY
OVER NE LAKE SUPERIOR TO ACCOUNT FOR THIS UNCERTAINTY.
DECENT SPREAD IN GUIDANCE FOR HIGHS DUE TO THE DIFFERENCES IN
HANDLING THE PHASING OF THE UPPER THROUGH. MIXING TO H875-850
/AROUND 2C/ YIELDS HIGHS IN THE MID 50S...SO HAVE ADJUSTED EXISTING
HIGHS DOWN A TOUCH. WITH MAINLY NW FLOW...HAVE KEPT TEMPS NEAR LK
SUPERIOR A LITTLE COOLER. DEWPOINT VALUES WILL BE THE MAIN CONCERN
FOR TUES AFTN. DROPPED VALUES A GOOD 7-10 DEGREES OVER THE WRN
HALF OF THE CWA...WITH MODELS CONSISTENTLY SHOWING DECENT MIXING
INTO DRY AIR ALOFT. SOME OF OUR LOCAL MIXED TD TOOLS ACTUALLY GIVE
VALUES IN THE SINGLE DIGITS ABOVE ZERO...WHICH DOESN/T SEEM TOO
UNREASONABLE. STRAIGHT MODEL MIXED TD VALUES ARE IN THE LOWER
TEENS...SO HAVE TRENDED TOWARDS THAT WITH VALUES IN THE UPPER
TEENS. FORTUNATELY...THERE IS STILL A DECENT SNOW PACK...OTHERWISE
THERE COULD BE FIRE WX CONCERNS WITH GUSTY NW WINDS AND RH VALUES
FALLING INTO THE LOW 20S.
TUES NIGHT...WITH UPPER TROUGH CONTINUING E AND UPPER RIDGE
REBUILDING OVER THE NRN PLAINS...EXPECT DRY WX AND MOSTLY CLEAR
SKIES. SFC RIDGE MOVING ACROSS THE AREA WILL LEAD TO LIGHT WINDS
AND HAVE DROPPED TEMPS A FEW DEGREES. COULD SEE TEMPS FALL A LITTLE
MORE THAN EXPECTED OVER THE ERN CWA...DUE TO LIGHTER WINDS AND DRY
AIR ALOFT PRODUCING PWATS AROUND 70 PERCENT OF NORMAL. HAVE COOLED
THE TRADITIONAL COLD SPOTS SOME OVER THE ERN CWA TO BELOW FREEZING
VALUES. FINALLY...H850 WAA COULD LEAD TO A FEW CLOUDS DEVELOPING
OVER THE WRN LK AND WRN UPPER MI AFTER MIDNIGHT...BUT LIMITED
MOISTURE HAS CONFIDENCE LOW.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 411 AM EDT MON MAR 12 2012
WED...THE UPR RDG OVER THE GRT LKS WL MOVE SLOWLY TO THE E...BUT ITS
EWD PROGRESS WL BE SLOWED BY CUTOFF LO OVER NEW ENGLAND. AS A FAIRLY
STRONG DISTURBANCE MOVES INTO CNTRL CAN...ITS ATTENDANT TROF WL
APRCH THE UPR LKS BY LATE IN THE DAY. THE NAM IS THE FASTEST MOVING
THIS TROF ACRS THE CWA ON WED...BUT PREFER THE CONSENSUS OF THE
SLOWER MODELS GIVEN THE BLOCKING CUTOFF IN NEW ENGLAND. THESE MODELS
HINT THE TROF WL REACH THE W ONLY LATE IN THE DAY. WITH THE DRYNESS
OF THE ANTECEDENT AIRMASS AND A LACK OF ANY SGNFT UPR FORCING SO FAR
S OF THE DISTURBANCE MOVING THRU CNTRL CAN...OPTED TO RETAIN GOING
DRY FCST. WITH H85 TEMPS PEAKING ARND 10C...EXPECT ANOTHER DAY OF
WELL ABV NORMAL TEMPS...EVEN IF THE MORE PESSIMISTIC GFS IS CORRECT
ON SHOWING ENUF LLVL MSTR ARRIVING TO SUPPORT SC DEVELOPMENT IN THE
SW FLOW AHEAD OF THE INCOMING TROF. MIXING TO JUST H875 ON GFS FCST
SDNGS WOULD YIELD HI TEMPS APRCHG 70 AWAY FM THE MODIFIYING
INFLUENCE OF LK MI WITH LLVL SLY FLOW...ESPECIALLY IN THE DOWNSLOPE
AREAS W OF MQT. SUSPECT AT LEAST SOME PLACES OVER THE W HALF MAY SEE
DAILY RECORD HI TEMPS.
WED NGT...AS THE SFC TROF/PACIFIC TYPE COLD FNT MOVES E ACRS THE
CWA...THE 00Z GFS AND ESPECIALLY THE CNDN MODELS ARE MOST AGGRESSIVE
AT GENERATING SOME PCPN OVER MAINLY THE SE ZNS UNDER AREA OF STEEPER
H7-5 LAPSE RATES UP TO 7.5-8.0C/KM AND SHOWALTER INDEX AS LO AS -2
TO -4C. THE CNDN INSTABILITY IS GREATER AS THIS MODEL SHOWS A
STRONGER SHRTWV MOVING ENEWD IN THE WSW FLOW ALF. ALTHOUGH THE TIME
OF DAY WOULD NOT BE CONDUCIVE TO TS...OPTED TO INCLUDE SCHC TS OVER
THE SE ZNS CONSIDERING THE ANOMALOUS LLVL WARMTH OF THE ANTECEDENT
AIRMASS/FCST STABILITY INDICES. DRIER AND SOMEWHAT COOLER AIR WL
ARRIVE OVER ESPECIALLY THE W IN THE WAKE OF THE COLD FROPA AS WEAK
HI PRES MOVES TO THE MN ARROWHEAD BY 12Z THU.
EXTENDED...THE STEADY SLY FLOW BTWN WRN TROF/ERN RDG WL PERSIST THRU
THE WEEKEND WITH NEAR UNPRECEDENTED WARMTH POSSIBLE FRI THRU SUN IN
THE PRESENCE OF H85 TEMPS NOT FAR FM 10-12C. THE THU-FRI PERIOD
SHOULD BE DRY WITH HI PRES RDG OVER THE AREA...BUT THERE WL BE A CHC
OF SHRA OVER THE WEEKEND AS HI PRES SHIFTS TO THE E. LACK OF
CONSISTENCY ON SHRTWV PRESENCE/TIMING SUGS NO MORE THAN CHC POPS ARE
WARRANTED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 126 AM EDT MON MAR 12 2012
A MID LEVEL LOW PRESSURE SYSTEM DEVELOPING OVER ERN KS WILL LIFT
NORTHEAST INTO NW WI BY MONDAY AFTERNOON. S-SE WINDS AHEAD OF THIS
FEATURE WILL BRING IN INCREASING LOW-LVL MOISTURE AND A BAND OF RAIN
SHOWERS LATE TONIGHT AND MONDAY. EXPECT CONDITIONS TO QUICKLY FALL
FROM VFR TO IFR AND THEN TO ALT LANDING MINS AT KCMX AND KSAW BY
LATE MORNING MONDAY IN SE-E WIND UPSLOPE FOG AND STRATUS. SNOW PACK
WILL LIKELY ENHANCE FOG POTENTIAL. LOOK FOR CONDITIONS TO IMPROVE TO
IFR AS KCMX AND KSAW BY MID MONDAY AFTERNOON AS RAIN TAPERS OFF AND
WINDS VEER MORE TO THE SW. CONDITIONS AT KCMX AND KSAW MAY DIP BACK
DOWN TO ALT LANDING MINS MON EVENING AS NOCTURNAL FALL IN TEMPS AND
LINGERING LOW-LVL MOISTURE LEADS TO SATURATION. CONDITIONS WILL
LIKELY IMPROVE TO MVFR AT KIWD BY LATE MONDAY EVENING AS DRIER AIR
ADVECTS IN FROM THE WEST BEHIND SYSTEM/S COLD FRONT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 AM EDT MON MAR 12 2012
UPPER LEVEL DISTURBANCE AND SURFACE TROUGH WILL SLIDE NE ACROSS
LAKE SUPERIOR THIS AFTERNOON AND TONIGHT. EXPECT SSE WINDS TO
MAINLY STAY BELOW 20KTS...BUT THERE COULD BE A FEW GUSTS TO 25KTS
OVER THE NRN LK. AS WARM/MOIST AIR MOVES OVER LAKE SUPERIOR
TODAY...SHOULD SEE AREAS OF FOG DEVELOP LATE THIS MORNING AND
CONTINUE INTO THIS EVENING. BEHIND THE SURFACE TROUGH...EXPECT
WINDS TO INCREASE OUT OF THE WEST AFTER MIDNIGHT AND CONTINUE INTO
TUESDAY. WARM AIR ABOVE THE SURFACE WILL LIKELY KEEP THE MARINE
LAYER IN PLACE AND LIMIT THE VERY STRONG WINDS ALOFT FROM
REACHING THE SURFACE. AT THIS TIME...ONLY HAVE GUSTS REACHING
30KTS. AFTER TUESDAY...WINDS WILL REMAIN UNDER 25KTS WITH A
RELATIVELY WEAK PRESSURE GRADIENT IN PLACE.
&&
.HYDROLOGY...
ISSUED AT 411 AM EDT MON MAR 12 2012
NEAR RECORD TO RECORD SETTING TEMPS YESTERDAY HAS HELPED RIPEN THE
SNOW PACK. RAIN TODAY AND FOR PARTS OF TONIGHT WILL PROVIDE
ADDITIONAL MOISTURE TO THE AREA. EXPECT THE BULK OF THE
RAIN TO FALL DURING THE MORNING TO EARLY AFTERNOON HOURS...WITH
ACCUMULATIONS OF AROUND 0.25 TO 0.40IN. THE RAIN...COMBINED
WITH DEWPOINTS RISING INTO THE 40S...WILL HELP TO QUICKEN
SNOWMELT. AS OF THIS MORNING...THERE HAS BEEN ONLY LIMITED
RESPONSES ON THE LARGER RIVERS.
THE RAIN AND SNOW MELT TODAY...COMBINED WITH ABOVE NORMAL
TEMPERATURES THROUGH NEXT WEEKEND WILL LEAD TO A INCREASE IN
RIVER AND STREAM LEVELS OVER THE NEXT SEVERAL DAYS. EXPECT SOME OF
THE RIVERS ACROSS THE AREA TO EXCEED THEIR BANKS BY THE END OF THIS
WEEK. PERSONS LIVING NEAR RIVERS AND STREAMS SHOULD
MONITOR THE LATEST RIVER CONDITIONS AND USE CAUTION IF WALKING
ALONG RIVER BANKS...ESPECIALLY THE CHOCOLAY RIVER...TRAP ROCK
RIVER...AND THE STURGEON RIVER IN WESTERN UPPER MICHIGAN.
ICE JAM WISE...NOT MUCH ICE HAS BEEN NOTED BY OBSERVERS ON THE
FASTER FLOWING RIVERS OVER NRN UPPER MI. BUT THE FORD RIVER...BOTH
AT HYDE AND THE MOUTH AT LK MI...STILL HAS GOOD ICE COVER THAT
LEADS TO SOME CONCERN FOR ICE JAM POTENTIAL WITH THE FASTER RUNOFF.
ALTHOUGH LIMITED SNOW WAS NOTED NEAR LK MI...THERE IS STILL 4-9IN
OF SNOW ...AND NOHRSC ESTIMATED AROUND 1.25IN OF LIQUID...TOWARDS
THE HEADWATERS THAT WILL BE MELTED OVER THE COMING DAYS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...VOSS
MARINE...SRF
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
124 AM EDT MON MAR 12 2012
.UPDATE...
ISSUED AT 1018 PM EDT SUN MAR 11 2012
LATEST WATER VAPOR IMAGERY SHOWS A WELL DEFINED UPPER LOW MOVING
TOWARD THE WESTERN GREAT LAKES. REGIONAL RADAR SHOWS A STEADY
INCREASE IN PCPN SOUTHWEST OF THE CWA. BASED ON RADAR TRENDS AND
LATEST RUC DATA...WE INCREASED POPS OVERNIGHT. THUNDER STILL A
POSSIBILITY AFTER 06Z AS THETA-E DECREASES WITH HEIGHT.
&&
.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 337 PM EDT SUN MAR 11 2012
FORECAST IMPACTS REVOLVE AROUND SEVERE THREAT MONDAY AFTERNOON AND
EVENING. SPC CURRENTLY HAS UPGRADED MUCH OF SOUTHERN AND CENTRAL
LOWER MICHIGAN TO A SLIGHT RISK FOR DAY 2 BUT THIS IS CONDITIONAL ON
AIRMASS RECOVERY/SFC HEATING IN DRY SLOT AFTER FIRST BATCH OF
SHOWERS AND STORMS MOVES THROUGH LATE TONIGHT AND EARLY MONDAY
MORNING.
12Z NAM IS MOST BULLISH ON SEVERE THREAT SHOWING MUCH BETTER
INSTABILITY MONDAY AFTERNOON WITH SFC HEATING AND STEEP LAPSE RATES
IN THE DRY SLOT...WHILE 12Z GFS AND ECMWF SUGGEST LESS SFC BASED
INSTABILITY BUT STILL SOME POTENTIAL FOR CONVECTION AS SHEAR
PROFILES AND HELICITIES WOULD SUPPORT STRONG TO SEVERE STORMS
INCLUDING ROTATING UPDRAFTS IF SFC BASED INSTABILITY IS REALIZED.
FOR TONIGHT...LEADING EDGE OF SHOWERS SHOULD ARRIVE ACROSS THE FAR
SOUTHWEST CWA AFTER MIDNIGHT AND SPREAD NORTH. BEAST CHANCE FOR RAIN
WILL BE FROM 08Z TO 14Z AS THIS FIRST BATCH MOVES THROUGH. FORECAST
SOUNDINGS SUGGEST MARGINAL ELEVATED INSTABILITY...BUT ENOUGH TO
INCLUDE ISOLATED THUNDER IN THE FORECAST.
THEN THE DRY SLOT ARRIVES AND THERE SHOULD BE A LULL BETWEEN 14Z AND
18Z...FOLLOWED BY POTENTIAL FOR MORE CONVECTION AS SECONDARY SPEED
MAX ROTATES THROUGH DURING THE LATE AFTERNOON AND EARLY EVENING.
GIVEN STRONG SPEED SHEAR PROFILES AND DECENT LOW LEVEL
HELICITIES...CONVECTIVE TRENDS WILL HAVE TO BE CLOSELY MONITORED
DURING THE AFTERNOON AND EVENING. THREAT DECREASES AFTER 00Z WITH
LOSS OF SFC BASED INSTABILITY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 337 PM EDT SUN MAR 11 2012
UNSEASONABLY WARM WX ANTICIPATED THRU THE LONG RANGE FCST PERIOD
WITH TEMPS AVERAGING 20 TO 25 DEGREES ABOVE NORMAL THROUGH THE
WEEKEND INTO EARLY NEXT WEEK. HIGH PRESSURE WILL BRING FAIR AND VERY
WARM WX TUE/WED WITH MAX TEMPS REACHING THE UPPER 50S TO LOWER 60S
TUE AND UPPER 60S TO LOWER 70S WED.
A WEAK FRONTAL BOUNDARY WILL BRING A FEW SHOWERS WEDNESDAY NIGHT AND
A FEW SHOWERS MAY LINGER THURSDAY THROUGH SATURDAY AS THE SW FLOW
WARM AIR ADVECTION PATTERN CONTINUES. HOWEVER COVERAGE OF ANY
SHOWERS THUR-SAT SHOULD BE LOW AND MOST OF THE TIME DRY CONDITIONS
WILL CONTINUE ALONG WITH UNSEASONABLY WARM CONDITIONS.
SOME OF THE WARMEST WEATHER OF ALL SHOULD COME SUNDAY AND ESPECIALLY
MONDAY OF EARLY NEXT WEEK AS A HIGH AMPLITUDE RIDGE/OMEGA BLOCK
DEVELOPS RIGHT OVER THE GREAT LAKES REGION AS A DEEP TROF CARVES
ITSELF OUT OVER THE ROCKIES. IT IS POSSIBLE THAT THE FIRST 80 DEGREE
READING OF THE YEAR COULD COME BY NEXT MONDAY AS H5 HEIGHTS REACH
580 DM WITH H8 TEMPS POTENTIALLY REACHING 14-16C BY THEN. MEX
NUMERICAL GUIDANCE MAX TEMPS ARE BEING SKEWED DOWN TOO MUCH BY CLIMO
VALUES FOR NEXT WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 120 AM EDT MON MAR 12 2012
RADAR SHOWS LIGHT RAIN MOVING TOWARD LOWER MICHIGAN. CIGS WILL
FALL TO MVFR OVERNIGHT AS THE RAIN MOVES IN. NOT EXPECTING TSRA AT
THE TAF SITES OVERNIGHT. A QUESTION MARK REMAINS CONCERNING STORMS
LATER THIS AFTERNOON. SOME INGREDIENTS EXIST FOR STRONG TO SEVERE
STORMS MAINLY AFTER 20Z AT THE THE SRN TAF SITES. WE COVERED THIS
WITH A VCTS COMMENT. IT/S POSSIBLE COVERAGE COULD BE MORE
WIDESPREAD THAN THAT BUT CONFIDENCE WASN/T HIGH ENOUGH TO PUT AS A
PREDOMINATE GROUP.
&&
.MARINE...
ISSUED AT 337 PM EDT SUN MAR 11 2012
DROPPED THE SCA FOR ALL BUT THE NORTHERN MARINE ZONE BASED ON
CURRENT OBS AND TRENDS. CONDITIONS SHOULD IMPROVE OVERNIGHT BUT
SHOWERS AND THUNDERSTORMS ARE POSSIBLE AFTER MIDNIGHT.
&&
.HYDROLOGY...
ISSUED AT 337 PM EDT SUN MAR 11 2012
SOME RISES ARE POSSIBLE THIS WEEK AS RAIN AND THUNDERSTORMS ARE
POSSIBLE MONDAY AFTERNOON AND THURSDAY INTO THURSDAY NIGHT.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...93
SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM....LAURENS
AVIATION...93
MARINE...OSTUNO
HYDROLOGY...OSTUNO
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1234 AM CDT MON MAR 12 2012
.AVIATION...
THE UPPER LOW WILL CONTINUE CROSSING EASTERN NEBRASKA OVERNIGHT
AND WIDESPREAD RAIN WILL CONTINUE EAST OF A VTN-MHN-LBF LINE AND
SLOWLY END FROM THE WEST. IT IS LIKELY TO MOVE EAST OF AN ONL-BBW
LINE BY 15Z. WITH THE RAIN...LOW CEILINGS 800-1200 FEET AGL AND
VISIBILITY AT OR BELOW 3SM CAN BE EXPECTED. CEILING IN THE REST OF
THE AREA WILL BE AT OR ABOVE 4000 FEET AGL WITH UNRESTRICTED
VISIBILITY.
WIND AT VTN AND LBF IS EXPECTED TO SWITCH TO THE NORTHWEST
09-12Z AND BECOME 290-320 AT 12-16G24-28KT 14-18Z.
&&
.PREV DISCUSSION... /ISSUED 653 PM CDT SUN MAR 11 2012/
SHORT TERM UPDATE...
BASED ON RADAR AND RECORDED PRECIPITATION AMOUNTS...WE HAVE
UPDATE THE FORECAST FOR TONIGHT FOR HIGHER PROBABILITY OF
PRECIPITATION AND SLIGHTLY HIGHER PRECIPITATION AMOUNTS FOR THIS
EVENING IN NORTH CENTRAL THROUGH SOUTHWEST NEBRASKA EAST OF A LINE
FROM VALENTINE THROUGH MULLEN AND OGALLALA TO IMPERIAL.
&&
.PREV DISCUSSION... /ISSUED 310 PM CDT SUN MAR 11 2012/
DISCUSSION...
THE UPPER LEVEL LOW ACROSS ERN COLO/WRN KS WILL LIFT SLOWLY NORTHEAST
THRU ERN NEB OVERNIGHT. CURRENT RADAR TRENDS AND THE RUC SUGGEST
ISOLATED SHOWERS THIS EVENING AS FAR WEST AS SWRN NEB WHICH THEN
SPREAD NORTHEAST OVERNIGHT AND EXIT THE FCST AREA BY ROUGHLY 12Z
MONDAY.
ANOTHER BIG FIRE DAY IS POSSIBLE MONDAY. BLENDED BIAS CORRECTED
MET MAV DEW PT DATA POINTS TOWARD DEW POINTS IN THE UPPER TEENS.
MEANWHILE THE STRONGER MAV WINDS AND ASSOCIATED DEEPER MIXING
PRODUCES STRONGER WINDS. SO RED FLAG CONDITIONS ARE POSSIBLE
ACROSS A LARGE PART OF THE FCST AREA. GREATER FIRE DANGER COULD
DEVELOP TUESDAY AS LOW PRESSURE ACROSS ALBERTA AND SASKATCHEWAN
DEEPENS TO AROUND 985 MB. A DRY LINE IS FCST TO DEVELOP AND PUSH
EAST TO AROUND HIGHWAY 183 WITH WINDS GUSTING TO 25 TO 30KTS. ON
WEDNESDAY CANADIAN LOW PRESSURE WILL FORCE THE DRY LINE FARTHER
EAST TO NEAR OMAHA WHICH COULD ALSO PRODUCE CRITICAL FIRE DANGER.
TEMPERATURES CONTINUE TO SOAR IN ALL MODEL SOLNS THROUGH WEDNESDAY.
THE CANADIAN LOW PRESSURE SYSTEMS WILL TRACK FAR ENOUGH NORTH TO
PREVENT ANY KIND OF STRONG COLD FRONTS AND COOLER TEMPS FROM
MOVING THROUGH THE FCST AREA BUT IT APPEARS THE SYSTEMS WILL BE
STRONG ENOUGH TO PREVENT THE DRY LINE FROM BACKING UP VERY FAR
WEST. THIS IS VERY UNCERTAIN AT THIS POINT AS WE HAVE YET TO SEE
THIS TYPE OF PATTERN AND IN WET YEARS THE DRY LINE TENDS TO HANG
OUT AROUND HIGHWAY 61.
THE GFS CONTINUES TO INDICATE SOME CIRRUS TUESDAY AND WEDNESDAY
BUT THIS SHOULD BE A FAIRLY THIN VEIL AND HAVE ONLY MINOR IMPACT ON
MAX TEMPS.
THURSDAY THROUGH SUNDAY...THE ECM CONTINUES TO KEEP A DEVELOPING
LONG WAVE TROF WEST OF THE FCST AREA. WITH NO SIGNIFICANT NRN
STREAM LEAD SHORT WAVE...THE FCST AREA SHOULD REMAIN IN THE WARM
SECTOR. A SERIES OF LOW PRESSURE SYSTEMS LIFT OUT OF THE TROF AND
THROUGH THE ROCKIES AND HIGH PLAINS. EACH WILL SUBSEQUENTLY DRAW
HIGH PRESSURE AND COOLER TEMPS CLOSER TO THE FCST AREA. THE
EARLIEST WE MIGHT SEE COOLING IS NEXT SUNDAY WHEN WINDS MAY BACK
AROUND TO THE EAST IN RESPONSE TO DEEP LOW PRESSURE ACROSS ERN WY.
THE GFS IS FASTER BRINGING THE LONG WAVE TROF EAST QUICKER. THE
FCST LEANS TOWARD THE SLOWER ECM AND WARMER TEMPS.
THERE IS SOME SPREAD IN THE POSITION OF A VERY STRONG DRY LINE FCST
TO DEVELOP ACROSS CNTL NEB IN THE EXTENDED FCST. ALL SOLNS INDICATE
DEW POINTS IN THE 50S ACROSS ERN NEB WITH 20S OVER WRN NEB. THESE
DIFFERENCES APPEAR TO BE RELATED TO THE TIMING...LOCATION AND
INTENSITY OF THE DISTURBANCES LIFTING OUT OF THE LONG WAVE TROF.
THE MODELS APPEAR TO BE DEVELOPING A BROAD AREA OF NOCTURNAL
STRATUS IN THE DEEPER MOISTURE EAST OF THE DRY LINE SO THE POSITION OF THE
DRY LINE WILL BE CLOSELY WATCHED. LATER MODEL SOLNS MAY SHOW THE
DRY LINE BACKING UP WESTWARD TOWARD A MORE CLIMATOLOGICAL
LOCATION.
FIRE WEATHER...
A FIRE WEATHER WATCH HAS BEEN ISSUED FOR FIRE ZONES
204...206...209...210 AND 219 MONDAY AFTERNOON. THE COMBINATION OF
CURED FUELS...WEST NORTHWESTERLY DOWNSLOPING WIND...AND ABNORMALLY
WARM TEMPERATURES WILL CREATE CONDITIONS FAVORABLE FOR EXTREME FIRE
GROWTH. ONE CAVEAT HOWEVER...WIND SPEEDS MAY BE MARGINAL /BELOW RFW
CRITERIA/ AS HIGH PRESSURE BUILDS OVER THE REGION. BUT EMPLOYING
THE USE MAV GUIDANCE WOULD INDICATE THE POTENTIAL FOR GUSTS OF 25
MPH FOR A THREE TO FOUR HOUR PERIOD EARLY MONDAY AFTERNOON. BUFR
SOUNDINGS AND OTHER GUIDANCE INDICATE A WEAKER WIND PROFILE...WITH
THE NAM GOING AS FAR AS TO SUGGEST WIND SPEEDS OF LESS THAN 20 KTS
AT 700MB OVER MUCH OF THE CWA BY 21Z CONSIDERING THAT THE MODELS
INDICATE A RELAXING PRESSURE GRADIENT...PEAK WIND SPEEDS MAY NOT
CORRESPOND WITH PEAK HEATING/MINIMUM RH. HOWEVER...THE MODELS
GENERALLY HAVE STRUGGLED RECENTLY AND UNDERESTIMATED NOT ONLY WIND
SPEEDS BUT ALSO TEMPERATURES/RH VALUES DURING PEAK HEATING...FELT
THAT CONFIDENCE WAS HIGH ENOUGH FOR AT LEAST A FIRE WEATHER WATCH AT
THIS TIME. WILL INCLUDE MOST OF WESTERN AND NORTH CENTRAL NEBRASKA
IN THIS WATCH THAT WILL BE IN EFFECT FROM 17Z MONDAY UNTIL 01Z
TUESDAY.
FIRE HEADLINES MAY BE NEEDED FOR THE REMAINDER OF NEXT WEEK AS
RIDGING BUILDS OVER THE CENTRAL AND NORTHERN PLAINS. TEMPERATURES
BEYOND MONDAY SHOULD REMAIN IN THE 70S FOR HIGHS THROUGH THE END OF
THE WORK WEEK. IN FACT...TEMPERATURES TUESDAY THROUGH THURSDAY MAY
APPROACH 80 DEGREES ALONG AND SOUTH OF THE INTERSTATE 80
CORRIDOR...AND ACROSS MUCH OF THE CENTRAL/NORTHERN SAND HILLS. WITH
CURED FUELS IN PLACE...THESE ABOVE NORMAL TEMPERATURES WILL COMBINE
WITH MEAGER ATMOSPHERIC MOISTURE AND AT TIMES GUSTY WIND SPEEDS TO
CREATE CONDITIONS FAVORABLE FOR EXTREME FIRE BEHAVIOR. ALL FIRE
INTERESTS SHOULD MONITOR THIS SITUATION CLOSELY UNTIL APPRECIABLE
MOISTURE FALLS OR GREEN UP OCCURS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING
FOR NEZ204-206-209-210-219.
&&
$$
SHORT TERM/EXTENDED...CDC
FIRE WEATHER...JACOBS
AVIATION/SHORT TERM UPDATE...SPRINGER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
729 PM EDT TUE MAR 13 2012
.SYNOPSIS...
HIGH PRESSURE OFFSHORE WILL EXTEND WESTWARD ACROSS THE EASTERN
CAROLINAS INTO EARLY NEXT WEEK. SOUTHERLY WINDS WILL BRING WARM
TEMPERATURES. A WEAK FRONT MAY BRIEFLY REACH THE AREA WEDNESDAY
BEFORE DISSIPATING. THERE WILL BE SOME OPPORTUNITY FOR RAINFALL
INTO TONIGHT...AND THEN AGAIN DURING THE WEEKEND AS A COLD FRONT
APPROACHES THE AREA.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 6:45 PM TUESDAY...HAVE DROPPED POPS TO THE SLIGHT CHANCE
CATEGORY AND ELIMINATED QPF FOR THE EVENING HOURS. CONVECTION JUST
CANNOT GET GOING LATE THIS AFTERNOON. RADAR LOOPS SHOW SOME BRIEF
FLARE-UPS OVER OUR SC COUNTIES...THEN A FEW SCANS LATER...GONE.
WATER VAPOR LOOPS SHOW BULK OF SHORT WAVE ENERGY PASSING TO OUR
SOUTH AND WITH LOSS OF DAYTIME HEATING SEE LITTLE IN THE WAY OF
TRIGGERS FOR SIGNIFICANT CONVECTION FOR THE REMAINDER OF THE NEAR
TERM. NEXT UPDATE WILL LIKELY ELIMINATE POPS COMPLETELY. HAVE ALSO
ADJUSTED THE TEMPERATURE CURVE UPWARDS BY A FEW DEGREES FOR THE
AFTERNOON AND EVENING HOURS. LATEST OBS SHOW PLENTY OF MID 70S AND
EVEN SOME UPPER 70S WELL INLAND. PREVIOUS DISCUSSION FOLLOWS:
SHORTWAVE EVIDENT ON WV IMAGERY MOVING ACROSS THE UPSTATE OF SC IS
CREATING SOME SCATTERED SHOWERS/TSTMS WHICH ARE PUSHING EAST
TOWARDS THE ILM CWA. THIS ACTIVITY IS NOT AS WIDESPREAD AS
PREVIOUSLY ANTICIPATED...WHICH IS INTERESTING SINCE CLOUDS HAVE
BROKEN...WHICH WAS EXPECTED TO BE THE LIMITING FACTOR TO
CONVECTIVE TRIGGER. A GLANCE AT LATEST RUC SOUNDINGS INDICATE A
SUBADIABATIC LAYER BETWEEN 950MB-800MB WHICH IS LIKELY ACTING AS A
WEAK CAP TO INHIBIT SURFACE PARCELS FROM BECOMING UNSTABLE...AND
LACK OF AGITATED CU IN THE CLEAR BREAKS IS A FURTHER SIGNAL OF
THIS. APPEARS THE NAM/SREF ARE OVERDOING CONVECTIVE POTENTIAL
THROUGH TONIGHT...SO HAVE TRIMMED SPATIAL COVERAGE OF CHANCE POP.
EXPECT THE AREA OF TSTMS JUST AHEAD OF THE S/W TO PUSH EAST AND
SURVIVE TO THE COAST IN THE NEXT SEVERAL HOURS...WITH HIGH CHANCE
TSTMS FROM ALONG AND SOUTH OF A LINE FROM HVS...TO MYR.
OTHERWISE...NO SIGNIFICANT PRECIP EXPECTED TO DEVELOP...WITH ONLY
SCHC POP ACROSS NORTHERN ZONES THROUGH TONIGHT BEFORE ACTIVITY
WILL ERODE DIURNALLY.
ONE LAST S/W WILL PIVOT THROUGH TONIGHT AND A WEAK COLD FRONT
APPROACHES FROM THE NW TRAILED FROM A LOW MOVING ACROSS NEW
ENGLAND. LATEST GUIDANCE HAS SPED UP THIS FRONT JUST
SLIGHTLY...AND HAVE VEERED WINDS TO THE WEST BY MORNING WEDNESDAY.
THIS FRONT ACTS AS THE MAIN PLAYER INTO FOG/STRATUS DEVELOPMENT
OVERNIGHT. DO NOT EXPECT FULL DECOUPLING SINCE THE GRADIENT WILL
REMAIN SLIGHTLY PINCHED...AND MET/MAV WIND VALUES REFLECT THIS
WELL. AT THE SAME TIME...FORECAST SOUNDINGS DEPICT A LLJ OF AROUND
20 KTS JUST ABOVE THE SURFACE INVERSION...ALL OF THESE WOULD POINT
TOWARDS A STRATUS EVENT TONIGHT IN THE MOIST ATMOSPHERE AS OPPOSED
TO FOG. HOWEVER...MODERATELY STEEP LOW LEVEL HYDROLAPSE RATES AND
CLEARING SKY CONDITIONS FAVOR FOG...AND CROSSOVER TEMPS WILL
LIKELY BE REACHED AT MOST LOCALES. FOR THIS REASON HAVE KEPT AREAS
OF FOG TO BE CONSISTENT WITH NEIGHBORS...BUT NOT MENTIONED
WIDESPREAD FOR THE POTENTIAL OF MORE STRATUS THAN FOG. HAVE
DROPPED MINS A DEGREE ACROSS THE BOARD FOR THE SLIGHTLY FASTER
VEER IN WIND DIRECTION...WITH LOW 50S FAR NW AND MID 50S AT THE
COAST. IF STRATUS BECOMES PREDOMINANT OR DEVELOPS MORE
RAPIDLY...THESE MINS MAY BE A BIT TOO COOL.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...FAIR WEATHER EXPECTED THROUGH THE PERIOD AS
HIGH PRESSURE CONTROLS AREA WEATHER. EXPECT HIGHS EACH DAY IN THE
UPPER 70S TO LOWER 80S...PERHAPS MID 80S WELL INLAND...WITH COOLER
ON TAP NEARER THE BEACHES. LOWS EACH NIGHT WILL FALL INTO THE
MIDDLE 50S. AFTER WEDNESDAY MORNING...SKIES SHOULD BE MAINLY CLEAR
THOUGH SOME INCREASE IN CLOUDS IS POSSIBLE IN ADVANCE OF THE NEXT
SYSTEM THURSDAY NIGHT. IT IS WORTH NOTING THAT ISOLATED SHOWERS ARE
POSSIBLE ALONG THE SEA BREEZE EACH AFTERNOON BUT THE PROBABILITY OF
SHOWERS IS LOW ENOUGH THAT MENTION IN THE FORECAST IS NOT WARRANTED
AT THIS TIME.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 PM TUESDAY...DECENT MODEL COHESIVENESS FRIDAY THROUGH
TUESDAY IN DEPICTING A DEVELOPING OMEGA-BLOCK PATTERN OVER THE
CONUS...WITH SUBTLE BUT IMPORTANT DIFFERENCES IN THE LONGITUDINAL
PLACEMENT OF THE OMEGA-RIDGE AXIS. THE FARTHER WEST POSITIONING
OFFERED IN THE ECMWF IMPLIES A MARITIME OR COASTAL-LOW INFLUENCE
IN OUR FORECASTS...WHEREAS THE GFS ENVELOPS THE REGION IN AN
AMPLIFYING UPPER RIDGE THROUGH THE EVOLUTION OF THE OMEGA-BLOCK
FORMATION...YIELDING WARM AND DRY. HAVE OPTED FOR SLIGHTLY LESS
AMPLIFIES SOLUTION TO THE GFS.
AT THE SURFACE...A WEAK SURFACE TROUGH WILL RESIDE ACROSS THE AREA
LATE FRIDAY THROUGH SATURDAY WITH ENOUGH MOISTURE TO WARRANT
MENTIONABLE POP VALUES. THE BOUNDARY WILL STALL SOUTH OF OUR AREA
SUNDAY ONWARD. RETURN FLOW SHOULD BRING A SLIGHT CHANCE OF SHOWERS
BY TUE. THIS PERIOD WILL BE MARKED BY ABOVE NORMAL TEMPERATURES
SINCE WE WILL BE IMPACTED BY THE RIDGE PORTION OF THE OMEGA-BLOCK.
THE COLD FRONTS WILL BE SHALLOW AND THE UPPER RIDGE WILL BE HIGHLY
AMPLIFIED OVER OR JUST WEST OF THE FORECAST AREA.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 00Z...EXPECT VFR THROUGH VALID PERIOD...WITH EXCEPTION OF
MVFR/IFR LATE OVERNIGHT INTO THE EARLY MORNING HOURS. CURRENT RADAR
IS QUIET...WITH CURRENT 11-3.9U SATELLITE LIGHTING UP WITH MID TO
HIGH LEVEL CLOUDS ASSOCIATED WITH A WEAK S/W PROPAGATING ACROSS THE
CAROLINAS. VFR WILL PREVAIL THROUGH THE EARLY OVERNIGHT HOURS...WITH
LIGHT SOUTH/SOUTHWEST WINDS. FOR THE EARLY MORNING
HOURS...TIME-HEIGHT ANALYSIS DEPICTS MODERATE LOW LEVEL MOISTURE
ACROSS MUCH OF THE AREA. THIS WITH ANTICIPATED LIGHTER WINDS
OVERNIGHT COULD AID IN THE DEVELOPMENT OF FOG. HOWEVER...CURRENT
GUIDANCE SUGGESTS A LLVL JET IN THE LOWEST 2KFT WHICH MAY INHIBIT
FOG DEVELOPMENT...AND OVERALL CREATE A MVFR/IFR STRATUS EVENT. FOR
NOW...HAVE KEPT IN MVFR FOG BEGINNING AFTER 8Z...EXCEPT FOR POSSIBLE
IFR AT KCRE JUST AFTER DAYBREAK...WITH IFR CIGS AT ALL TAF SITES.
AFTER 15Z...ANTICIPATE ANY FOG THAT MAY HAVE DEVELOPED TO QUICKLY
DISSIPATE. ANY LINGERING IFR/MVFR CIGS WILL GRADUALLY SCATTER TO
VFR. WINDS WILL BECOME GENERALLY WEST THROUGHOUT THE DAY AOB 10
KTS...BACKING MORE TOWARDS THE SOUTHWEST BY THE END OF THE VALID
PERIOD WITH WINDS AOB 5 KTS.
EXTENDED OUTLOOK...MORNING IFR FOG POSSIBLE THURSDAY. VFR FRIDAY.
SHOWERS POSSIBLE LATE FRIDAY INTO SATURDAY. VFR SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6:45 PM TUESDAY...WINDS HAVE PICKED UP A TAD OVER THE WATERS
BUT ARE STILL LIGHT...IN THE 10 KNOT RANGE EXCEPT NEAR THE COAST
WHERE THE SEA BREEZE CIRCULATION IS KICKING WINDS UP INTO THE 15
KT RANGE. SEAS RIGHT AROUND 2 TO 3 FT THIS EVENING. NO CHANGES
ANTICIPATED TO GOING FORECAST. PREVIOUS DISCUSSION FOLLOWS:
VERY LIGHT GRADIENT OVER THE WATERS CONTRIBUTING TO WINDS LESS
THAN 5 KTS AT ALL BUOYS. OF COURSE WITH NO WIND...THERE IS NO
MEANINGFUL WIND CHOP...AND THE WAVE SPECTRUM IS COMPLETELY
DOMINATED BY A SE 3FT/9SEC SWELL. THIS SWELL HAS ERODED A BIT ON
ACCOUNT OF THE POSITIONING OF THE OFFSHORE RIDGE NOT ALLOWING FOR
IDEAL SE FETCH...SO WAVE GUIDANCE HAS OVERESTIMATED SEAS BY ABOUT
A FOOT THIS AFTN...AND SEAS OF ONLY 2-3 FT PRESENTLY OCCURRING.
EXPECT FAIRLY UNIFORM WIND/WAVE CONDITIONS THROUGH
NIGHTFALL...BEFORE WINDS WILL INCREASE TO AROUND 10 KTS AS
GRADIENT BECOMES PINCHED JUST SLIGHTLY AND AIR TEMPS FALL TO
VALUES BELOW OCEAN TEMPS. THIS WILL CREATE SEAS BUILDING TO 3-4 FT
BY TUESDAY MORNING.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...GENERALLY EXPECT LIGHT SW FLOW THROUGH THE
PERIOD BUT THE PRESSURE GRADIENT WILL BE WEAK ENOUGH DURING THE
PERIOD THAT THE SEA BREEZE BY DAY AND LAND BREEZE BY NIGHT COULD
BECOME DOMINANT AT TIMES. THIS COULD PRODUCE S TO SE WINDS NEAR
SHORE IN THE AFTERNOON AND MORE WESTERLY WINDS OVERNIGHT. SPEEDS
WILL REMAIN BELOW 15 KT THROUGH THE PERIOD WITH MAXIMUM SEAS OF 3 FT
EXPECTED.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 3 PM TUESDAY...DECENT MARINE CONDITIONS FRI-SUN WITH
SUB-ADVISORY SW WINDS FRI AND SAT AHEAD OF AN INLAND SURFACE
TROUGH. THIS FEATURE WILL PUSH SOUTH OF OUR WATERS AS A COLD FRONT
SUNDAY WITH NE WIND FLOW BEHIND IT...BUT BELOW ADVISORY WIND SPEEDS
EXPECTED. IT WILL BE A BUMPY 3-4 FEET SUNDAY...AS THE NNE WIND-
WAVES CO-MINGLE WITH RESIDUAL SOUTH WAVE ENERGY. A FEW SHOWERS
POSSIBLE FRI AND SAT BUT NO TSTMS EXPECTED. PATCHY INSHORE FOG IS
POSSIBLE LATE FRIDAY AND SATURDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...REK/JDW
SHORT TERM...RAN
LONG TERM...MJC
AVIATION...SGL
MARINE...MJC/REK/JDW/RAN
AREA FORECAST DISCUSSION
NWS RALEIGH NC
333 PM EDT MON MAR 12 2012
.SYNOPSIS...
HIGH PRESSURE CENTERED OFFSHORE WILL CONTINUE TO EXTEND WESTWARD
INTO THE CAROLINAS THROUGH TONIGHT. A WEAK SURFACE TROUGH AND UPPER
LEVEL DISTURBANCE WILL PROGRESS INTO THE AREA FROM THE WEST ON
TUESDAY. A GENERAL WARMING TREND IS EXPECTED THROUGH MID-WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 215 PM MONDAY...
THIS AFTERNOON:
THE PROGRESSIVE UPPER LOW CURRENTLY IN THE NORTHERN MS RIVER VALLEY
WILL TRACK NORTHEAST INTO ONTARIO TODAY...WHILE ADDITIONAL SHORTWAVE
ENERGY CURRENTLY OVER SASKATCHEWAN/MONTANA PROGRESSES EAST TOWARD
MANITOBA. HEIGHT FALLS (ASSOC/W THE AFOREMENTIONED UPPER LOW) OVER
THE OH VALLEY/MID-ATLANTIC WILL PUSH THE H5 RIDGE OFFSHORE
TODAY...WITH INCREASINGLY WESTERLY FLOW ALOFT OVER CENTRAL NC. A
MINOR SHORTWAVE WAS PRESENT UPSTREAM OVER OKLAHOMA AT 15Z...AND IS
PROGGED TO PROGRESS EAST INTO THE WESTERN TN VALLEY BY 00Z THIS
EVENING. THE LATEST RUC MODEL DATA SHOWED A MID-LEVEL VORTICITY
MAXIMUM OVER THE DEEP SOUTH AT 15Z...APPARENTLY EMANATING FROM DEEP
CONVECTION/STRONG MID-LEVEL LATENT HEATING PRESENT OVER THE LA/MS
GULF COAST THIS MORNING...AND THE RUC SHOWS THIS FEATURE PROGRESSING
NORTHEAST INTO GA/UPSTATE SC/WESTERN NC BY 00Z THIS EVENING. IN THE
LOWER LEVELS...A 5-10 KT SOUTHERLY RETURN FLOW WILL PREVAIL OVER THE
AREA...ON THE WESTERN PERIPHERY OF THE LOW-LEVEL RIDGE AXIS NOW
CENTERED OFFSHORE THE CAROLINA COAST. W/REGARD TO PRECIP CHANCES...
LITTLE OR NO FORCING FOR ASCENT WILL BE PRESENT THIS AFTERNOON...
ASIDE FROM VERY WEAK/BROAD WARM ADVECTION ASSOC/W SOUTHERLY RETURN
FLOW. INCREASING MID/UPPER LEVEL CLOUD COVER (LIMITING INSOLATION IN
THE WEST) AND A LINGERING MID-LEVEL SUBSIDENCE INVERSION (ASSOC/W
THE DEPARTING H5 RIDGE AXIS IN THE EAST) SHOULD SIGNIFICANTLY HAMPER
ANY DIURNAL DESTABILIZATION THIS AFTERNOON...WITH VERY LITTLE OR NO
AVAILABLE INSTABILITY. AS A RESULT...EXPECT A DRY FORECAST THROUGH
00Z THIS EVENING. HIGHS WILL PRIMARILY DEPEND ON THE TIMING AND
COVERAGE OF MID/UPPER LEVEL CLOUD COVER SLOWLY PROGRESSING INTO THE
AREA FROM THE WEST. WILL FCST HIGHS RANGING FROM THE MID/UPPER 60S
(W/NW PIEDMONT) TO UPPER 60S/LOWER 70S ELSEWHERE.
TONIGHT:
UNCERTAINTY INCREASES TONIGHT...PRIMARILY WITH THE PRECIPITATION
FORECAST. FORCING FOR ASCENT OVER CENTRAL NC OVERNIGHT WILL
GENERALLY BE LIMITED TO WEAK/BROAD MID-LEVEL HEIGHT FALLS AND
LOW-LEVEL WARM ADVECTION. W/REGARD TO THERMODYNAMICS...WEAK
MID-LEVEL LAPSE RATES AND BAD DIURNAL TIMING WILL CONTRIBUTE TO VERY
LITTLE OR NO AVAILABLE INSTABILITY OVERNIGHT. THE ABOVE ALONE WOULD
ARGUE FOR VERY LITTLE OR NO CHANCE OF SHOWER ACTIVITY OVERNIGHT...
AND VIRTUALLY NO CHANCE OF THUNDER. HOWEVER...THE MID-LEVEL
VORTICITY MAXIMUM THAT DEVELOPED IN ASSOC/W DEEP CONVECTION UPSTREAM
OF THE AREA THIS MORNING IS PROGGED TO APPROACH THE WEST/SW PIEDMONT
BY ~00Z...PROGRESSING THROUGH CENTRAL NC OVERNIGHT. DESPITE POOR
THERMODYNAMICS AND WEAK BACKGROUND/SYNOPTIC ASCENT...DPVA ASSOC/W
THIS FEATURE WILL PROVIDE ADDITIONAL/FOCUSED FORCING...AND ISOLD/SCT
SHOWER ACTIVITY WILL CERTAINLY BE POSSIBLE. THE LATEST 12Z WRF-NMM
SIMULATED REFLECTIVITY PRODUCT IS MORE ROBUST THAN THE 00Z RUN IN
SHOWING SHOWER ACTIVITY DEVELOPING OVERNIGHT IN ASSOC/W THIS FEATURE.
ADDITIONALLY...THE SHORTWAVE CURRENTLY IN OKLAHOMA WILL APPROACH THE
SOUTHERN APPALACHIANS BY ~12Z TUE...AND SOME WEAK AMPLIFICATION WILL
BE POSSIBLE AS ADDITIONAL UPPER LEVEL ENERGY PROGRESSES FROM THE
DESERT SOUTHWEST INTO THE TN VALLEY. THIS COULD PROVIDE ADDITIONAL
FORCING FOR ASCENT FROM THE WEST CLOSE TO SUNRISE TUE MORNING...
ALTHOUGH THE LATEST GUIDANCE CONTINUES TO SUGGEST THE BEST FORCING
ASSOC/W THE SECOND WAVE WILL MOST LIKELY OCCUR AFTER SUNRISE...
DURING THE DAY TUE. WITH THE ABOVE IN MIND...FEEL THAT A SMALL
INCREASE IN PRECIP CHANCES IS WARRANTED OVERNIGHT...AND WILL
INDICATE A 30% CHANCE OF SHOWERS EVERYWHERE. DESPITE THE PRESENCE OF
AN UPPER LEVEL DISTURBANCE...GIVEN POOR DIURNAL TIMING AND WEAK/
INCREASINGLY MOIST ADIABATIC LAPSE RATES...LITTLE IF ANY INSTABILITY
IS EXPECTED...AND WILL LEAVE OUT MENTION OF THUNDER. WITH MOSTLY
CLOUDY OR OVERCAST SKIES...EXPECT LOWS MUCH WARMER THAN IN RECENT
DAYS...IN THE LOWER/MID 50S. -VINCENT
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 330 PM MONDAY...
TUESDAY:
AS MENTIONED IN THE NEAR TERM DISCUSSION...AN AMPLIFYING SHORTWAVE
IS EXPECTED TO PROGRESS EASTWARD ACROSS THE CAROLINAS DURING THE DAY
TUE...THOUGH THE EXACT TIMING REMAINS SOMEWHAT UNCERTAIN. IN THE
LOWER LEVELS...A PIEDMONT TROUGH DURING IS PROGGED TO DEVELOP DURING
PEAK HEATING. OTHERWISE...LIFT WILL BE CONFINED TO VERY WEAK/BROAD
LOW-LEVEL WARM ADVECTION AND MID-LEVEL HEIGHT FALLS. W/REGARD TO
THERMODYNAMICS...DESTABILIZATION WILL LIKELY BE HAMPERED BY
PERVASIVE CLOUD COVER THROUGH MUCH OF THE DAY...PARTICULARLY EAST OF
HIGHWAY 1. SOME CLEARING IS EXPECTED IN THE WEST/NW PIEDMONT BY ~18Z
IN THE PRESENCE OF A CONTINUED MOIST BOUNDARY LAYER...AND
INSTABILITY COULD ACTUALLY BE MORE FAVORABLE WEST OF HWY 1.
HOWEVER...SIGNIFICANT DRYING ALOFT IS ALSO EXPECTED AS A MUCH DRIER
MID/UPPER LEVEL AIRMASS ADVECTS INTO WESTERN PORTIONS OF THE STATE
TUE AFTERNOON...AND DRY AIR ENTRAINMENT MAY OFFSET OR COMPLETELY
NEGATE THE BENEFIT OF BETTER INSOLATION. REGARDLESS...WITH WEAK
MID-LEVEL LAPSE RATES OVER MOST OF THE AREA (ASIDE FROM WEST/NW
PIEDMONT) DURING PEAK HEATING...MLCAPE VALUES WILL LIKELY NOT EXCEED
250-500 J/KG. WITH THE ABOVE IN MIND...EXPECT SUFFICIENT FORCING AND
INSTABILITY TO WARRANT AT LEAST A LOW CHANCE (20-30%) OF SHOWERS/
STORMS...WITH THE BEST CHANCE OF THUNDER EAST OF HIGHWAY 1.
HOWEVER...IF FORCING ASSOC/W THE UPPER LEVEL WAVE IS STRONG ENOUGH
TO OVERCOME THE SIGNIFICANT AMOUNT OF DRY AIR ALOFT PROGGED IN THE
WEST/NW PIEDMONT...THUNDER WILL BE POSSIBLE THERE AS WELL. GIVEN
MARGINAL INSTABILITY...0-6 KM BULK SHEAR VALUES NO HIGHER THAN 20-25
KT (BARELY SUPPORTIVE OF MULTICELLULAR CONVECTION)...AND A
RELATIVELY SHALLOW MIXED LAYER WITH LITTLE POTENTIAL FOR
EVAPORATIVELY ENHANCED DOWNDRAFTS...DO NOT ANTICIPATE A SEVERE
THREAT WITH ANY CONVECTION. EXPECT HIGHS ON TUE TO RANGE FROM THE
UPPER 60S/LOWER 70S IN THE EAST TO THE LOWER/MID 70S IN THE WEST.
TUESDAY NIGHT:
SUBSIDENCE AND SHORTWAVE RIDGING BUILDING INTO THE AREA IN THE WAKE
OF THE SHORTWAVE SHOULD RESULT IN MOSTLY CLEAR SKIES TUE NIGHT.
GIVEN A WEAK/BAGGY MSLP GRADIENT AND THE CONTINUED PRESENCE OF A
MOIST BOUNDARY LAYER...ANTICIPATE A POTENTIAL FOR FOG ACROSS THE
AREA 06-12Z WED MORNING...ESPECIALLY IN AREAS THAT RECEIVE RAINFALL
DURING THE DAY TUE. EXPECT LOWS IN THE LOWER/MID 50S. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 230 PM MONDAY...
AS SURFACE SYSTEM MOVES OFFSHORE EARLY WEDNESDAY...WARM AIR WILL BE
SPREADING NORTH DUE TO SUBTROPICAL RIDGING INTO THE SOUTHERN PLAINS
AND WESTERN GULF STATES. HIGHS WEDNESDAY WILL BE 15 TO 20 DEGREES
ABOVE NORMAL...UPPER 70S OVER MOST OF THE AREA. MOISTURE WILL BE
BUILDING NORTH INTO THE TENNESSEE VALLEY AND POOLING ON THE WESTERN
SLOPES AS THE RIDGE HOLDS TIGHT THROUGH THURSDAY...INSTABILITY WILL
BE MINIMAL AND CAPPED...PROVIDING ANOTHER WARM DRY DAY WITH HIGHS IN
THE UPPER 70S TO LOWER 80S AFTER MILD MORNING LOWS IN THE LOWER 50S.
A MID LEVEL WAVE ORIGINATING IN THE SOUTHERN PLAINS WILL BE
DAMPENING THE RIDGE AMPLITUDE WITH WEAK SURFACE HIGH PRESSURE
SHIFTING OFFSHORE. THIS WILL PRODUCE A SLIGHT CHANCE OF SHOWERS
THURSDAY NIGHT...WITH A LITTLE BETTER CHANCES ON FRIDAY AS A WEAK
SURFACE FRONT EDGES VERY SLOWLY SOUTH AND EAST INTO THE MID ATLANTIC
REGION. PROGGED INSTABILITY IS SUFFICIENT FOR THUNDER GIVEN THE LOW
LEVEL FORCING AS HIGHS FRIDAY WILL STILL BE ON THE WARM SIDE...MID
TO UPPER 70S.
THE SURFACE FRONT WILL SAG FURTHER SOUTH ON SATURDAY AS LOW PRESSURE
AREA DEVELOPS OFF THE MID ATLANTIC COAST...WILL MAINTAIN SLIGHT
CHANCE TO CHANCE POPS ACROSS THE AREA THROUGH SATURDAY...AGAIN WITH
A CHANCE OF THUNDER GIVEN THE WARM AIRMASS AND POTENTIAL FOR THE
FRONT TO STALL OVER THE AREA. HIGHS WILL STILL BE IN THE MID TO
UPPER 70S.
THE FRONTS WILL BE SHOVED SOUTH OF THE AREA...SATURDAY NIGHT OR
SUNDAY AND WILL MAINTAIN SLIGHT CHANCES TO COVER THE TIMING
UNCERTAINTY. HIGH PRESSURE WILL WEDGE DOWN THE COAST SUNDAY/MONDAY
AND WILL TAPER OFF THE POPS SUNDAY NIGHT AND LEAVE MONDAY DRY FOR
NOW. HIGHS SUNDAY WILL BE IN THE LOW TO MID 70S WITH COOLER TEMPS IN
THE NORTHEAST WITH LINGERING CLOUD COVERAGE AND COOL AIR WEDGING
IN...WITH HIGHS ON MONDAY A TOUCH COOLER...LOWER 70S ACROSS THE
AREA.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 215 PM MONDAY...
24-HR TAF PERIOD:
VFR CONDITIONS ARE EXPECTED TO PREDOMINATE THROUGH 00Z THIS
EVENING...WITH SUB-VFR CONDITIONS POSSIBLE OVERNIGHT INTO TUESDAY.
VFR CEILINGS BETWEEN 3000-5000 FT WERE OBSERVED OVER MOST OF CENTRAL
NC AS OF 18Z THIS AFTERNOON. EXPECT CEILINGS TO REMAIN VFR OR
BORDERLINE MVFR AT BEST THROUGH 00Z THIS EVENING. TONIGHT...AN UPPER
LEVEL DISTURBANCE APPROACHING THE AREA FROM THE SOUTHWEST MAY HELP
ISOLD/SCT SHOWER ACTIVITY DEVELOP ACROSS THE AREA...THOUGH ENOUGH
UNCERTAINTY REMAINS TO PRECLUDE MENTION OF SHOWERS IN THE 18Z TAF
ISSUANCE. ADDITIONALLY...SOUTHWESTERLY RETURN FLOW AND WARM
ADVECTION IN THE LOWER LEVELS COULD RESULT IN THE DEVELOPMENT OF
MVFR/IFR CEILINGS ACROSS PORTIONS OF THE AREA OVERNIGHT. ALTHOUGH
SUB-VFR CONDITIONS WILL BE POSSIBLE EVERYWHERE...AT THIS TIME THE
BEST CHANCE THROUGH 12Z TUE APPEARS TO BE AT THE INT/GSO/RDU TAF
SITES. AFTER SUNRISE TUESDAY...THE FAY/RWI TAF SITES WILL HAVE THE
RELATIVE BEST CHANCE OF ISOLD/SCT SHOWER ACTIVITY AND SUB-VFR
CEILINGS. AN ISOLD THUNDERSTORM CANNOT BE RULED OUT AT FAY/RWI NEAR
OR PRIOR TO 18Z TUE. WINDS WILL BE SOUTHWEST AT ~10 KT THIS
AFTERNOON...WEAKENING TO ~5 KT OVERNIGHT...INCREASING TO ~10 KT
AGAIN ON TUE.
LOOKING AHEAD:
SUB-VFR CEILINGS OR FOG WILL BE POSSIBLE TUE NIGHT GIVEN MID/UPPER
LEVEL DRYING (CLEARING SKIES) IN THE PRESENCE OF A MOIST BOUNDARY
LAYER AND LIGHT/CALM WINDS. EXPECT VFR CONDITIONS TO PREVAIL WED
THROUGH THU IN ASSOC/W HIGH PRESSURE AND A RELATIVELY DRIER AIRMASS
IN PLACE. AFTER A BRIEF POTENTIAL FOR FOG FRIDAY MORNING...SHOWERS
AND STORMS WILL BE POSSIBLE FRI/FRI NIGHT AND POSSIBLY INTO SAT IN
ASSOC/W AN UPPER LEVEL DISTURBANCE AND SURFACE TROUGH PROGGED TO
PROGRESS THROUGH THE AREA. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...MLM
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
240 PM EDT MON MAR 12 2012
.SYNOPSIS...
HIGH PRESSURE CENTERED OFFSHORE WILL CONTINUE TO EXTEND WESTWARD
INTO THE CAROLINAS THROUGH TONIGHT. A WEAK SURFACE TROUGH AND UPPER
LEVEL DISTURBANCE WILL PROGRESS INTO THE AREA FROM THE WEST ON
TUESDAY. A GENERAL WARMING TREND IS EXPECTED THROUGH MID-WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 215 PM MONDAY...
THIS AFTERNOON:
THE PROGRESSIVE UPPER LOW CURRENTLY IN THE NORTHERN MS RIVER VALLEY
WILL TRACK NORTHEAST INTO ONTARIO TODAY...WHILE ADDITIONAL SHORTWAVE
ENERGY CURRENTLY OVER SASKATCHEWAN/MONTANA PROGRESSES EAST TOWARD
MANITOBA. HEIGHT FALLS (ASSOC/W THE AFOREMENTIONED UPPER LOW) OVER
THE OH VALLEY/MID-ATLANTIC WILL PUSH THE H5 RIDGE OFFSHORE
TODAY...WITH INCREASINGLY WESTERLY FLOW ALOFT OVER CENTRAL NC. A
MINOR SHORTWAVE WAS PRESENT UPSTREAM OVER OKLAHOMA AT 15Z...AND IS
PROGGED TO PROGRESS EAST INTO THE WESTERN TN VALLEY BY 00Z THIS
EVENING. THE LATEST RUC MODEL DATA SHOWED A MID-LEVEL VORTICITY
MAXIMUM OVER THE DEEP SOUTH AT 15Z...APPARENTLY EMANATING FROM DEEP
CONVECTION/STRONG MID-LEVEL LATENT HEATING PRESENT OVER THE LA/MS
GULF COAST THIS MORNING...AND THE RUC SHOWS THIS FEATURE PROGRESSING
NORTHEAST INTO GA/UPSTATE SC/WESTERN NC BY 00Z THIS EVENING. IN THE
LOWER LEVELS...A 5-10 KT SOUTHERLY RETURN FLOW WILL PREVAIL OVER THE
AREA...ON THE WESTERN PERIPHERY OF THE LOW-LEVEL RIDGE AXIS NOW
CENTERED OFFSHORE THE CAROLINA COAST. W/REGARD TO PRECIP CHANCES...
LITTLE OR NO FORCING FOR ASCENT WILL BE PRESENT THIS AFTERNOON...
ASIDE FROM VERY WEAK/BROAD WARM ADVECTION ASSOC/W SOUTHERLY RETURN
FLOW. INCREASING MID/UPPER LEVEL CLOUD COVER (LIMITING INSOLATION IN
THE WEST) AND A LINGERING MID-LEVEL SUBSIDENCE INVERSION (ASSOC/W
THE DEPARTING H5 RIDGE AXIS IN THE EAST) SHOULD SIGNIFICANTLY HAMPER
ANY DIURNAL DESTABILIZATION THIS AFTERNOON...WITH VERY LITTLE OR NO
AVAILABLE INSTABILITY. AS A RESULT...EXPECT A DRY FORECAST THROUGH
00Z THIS EVENING. HIGHS WILL PRIMARILY DEPEND ON THE TIMING AND
COVERAGE OF MID/UPPER LEVEL CLOUD COVER SLOWLY PROGRESSING INTO THE
AREA FROM THE WEST. WILL FCST HIGHS RANGING FROM THE MID/UPPER 60S
(W/NW PIEDMONT) TO UPPER 60S/LOWER 70S ELSEWHERE.
TONIGHT:
UNCERTAINTY INCREASES TONIGHT...PRIMARILY WITH THE PRECIPITATION
FORECAST. FORCING FOR ASCENT OVER CENTRAL NC OVERNIGHT WILL
GENERALLY BE LIMITED TO WEAK/BROAD MID-LEVEL HEIGHT FALLS AND
LOW-LEVEL WARM ADVECTION. W/REGARD TO THERMODYNAMICS...WEAK
MID-LEVEL LAPSE RATES AND BAD DIURNAL TIMING WILL CONTRIBUTE TO VERY
LITTLE OR NO AVAILABLE INSTABILITY OVERNIGHT. THE ABOVE ALONE WOULD
ARGUE FOR VERY LITTLE OR NO CHANCE OF SHOWER ACTIVITY OVERNIGHT...
AND VIRTUALLY NO CHANCE OF THUNDER. HOWEVER...THE MID-LEVEL
VORTICITY MAXIMUM THAT DEVELOPED IN ASSOC/W DEEP CONVECTION UPSTREAM
OF THE AREA THIS MORNING IS PROGGED TO APPROACH THE WEST/SW PIEDMONT
BY ~00Z...PROGRESSING THROUGH CENTRAL NC OVERNIGHT. DESPITE POOR
THERMODYNAMICS AND WEAK BACKGROUND/SYNOPTIC ASCENT...DPVA ASSOC/W
THIS FEATURE WILL PROVIDE ADDITIONAL/FOCUSED FORCING...AND ISOLD/SCT
SHOWER ACTIVITY WILL CERTAINLY BE POSSIBLE. THE LATEST 12Z WRF-NMM
SIMULATED REFLECTIVITY PRODUCT IS MORE ROBUST THAN THE 00Z RUN IN
SHOWING SHOWER ACTIVITY DEVELOPING OVERNIGHT IN ASSOC/W THIS FEATURE.
ADDITIONALLY...THE SHORTWAVE CURRENTLY IN OKLAHOMA WILL APPROACH THE
SOUTHERN APPALACHIANS BY ~12Z TUE...AND SOME WEAK AMPLIFICATION WILL
BE POSSIBLE AS ADDITIONAL UPPER LEVEL ENERGY PROGRESSES FROM THE
DESERT SOUTHWEST INTO THE TN VALLEY. THIS COULD PROVIDE ADDITIONAL
FORCING FOR ASCENT FROM THE WEST CLOSE TO SUNRISE TUE MORNING...
ALTHOUGH THE LATEST GUIDANCE CONTINUES TO SUGGEST THE BEST FORCING
ASSOC/W THE SECOND WAVE WILL MOST LIKELY OCCUR AFTER SUNRISE...
DURING THE DAY TUE. WITH THE ABOVE IN MIND...FEEL THAT A SMALL
INCREASE IN PRECIP CHANCES IS WARRANTED OVERNIGHT...AND WILL
INDICATE A 30% CHANCE OF SHOWERS EVERYWHERE. DESPITE THE PRESENCE OF
AN UPPER LEVEL DISTURBANCE...GIVEN POOR DIURNAL TIMING AND WEAK/
INCREASINGLY MOIST ADIABATIC LAPSE RATES...LITTLE IF ANY INSTABILITY
IS EXPECTED...AND WILL LEAVE OUT MENTION OF THUNDER. WITH MOSTLY
CLOUDY OR OVERCAST SKIES...EXPECT LOWS MUCH WARMER THAN IN RECENT
DAYS...IN THE LOWER/MID 50S. -VINCENT
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM MONDAY...
OVERNIGHT SHOWERS SHOULD BE MOVING INTO THE NORTHERN COASTAL PLAIN
BY AROUND 12Z TUESDAY MORNING AS THE FIRST ROUND OF FORCING
ASSOCIATED WITH A SHORTWAVE CROSSING THE GREAT LAKES MOVES OFF THE
MID ATLANTIC COAST. WESTERLY MID LEVEL FLOW BRING DRIER MID LEVEL
AIR ACROSS THE CWA DURING THE DAY...WITH A WEAK LEE TROUGH
DEVELOPING OVER THE WESTERN PIEDMONT/FOOTHILLS. A SECOND...LOW
AMPLITUDE UPPER TROUGH/DISTURBANCE IS THEN FORECAST TO CROSS THE
AREA BETWEEN 15 AND 21Z. BECAUSE THE ORIGINAL COLD FRONT WILL
ESSENTIALLY WASH OUT AS IT CROSS THE MOUNTAINS...LOW LEVEL MOISTURE
WILL CHANGE VERY LITTLE DURING THE DAY TUESDAY. STRONG HEATING
WILL ALLOW TEMPS TO RISE INTO THE LOW TO MID 70S WITH DEWPOINTS
HOLDING IN THE MID 50S. THIS DAYTIME HEATING COMBINED WITH SLIGHTLY
STEEPER MID LEVEL LAPSE RATES SHOULD LEAD TO ANOTHER ROUND OF
ISOLATED SHOWERS...FOCUSED MAINLY NEAR THE LEE TROUGH AND AIDED BY
THE AFOREMENTIONED WEAK UPPER TROUGH PASSAGE. THE MUCH DRIER MID
LEVEL AIR WILL LIMIT COVERAGE...BUT 400-800 J/KG MAY SUPPORT A FEW
ISOLATED THUNDERSTORMS OVER THE WESTERN PIEDMONT. WEAK DEEP LAYER
SHEAR AND THIN CAPE PROFILES SHOULD PRECLUDE ANY SEVERE STORMS...BUT
DOWNDRAFT CAPE COULD CLIMB INTO THE 500-1000 J/KG RANGE AND SUPPORT
SOME ENHANCED WIND GUSTS. BASED ON THE LIMITED COVERAGE
EXPECTED...WE WILL CONTINUE THE SLIGHT CHANCE POP ADVERTISED.
ANOTHER MILD NIGHT EXPECTED TUESDAY NIGHT AS SHOWERS COME TO AN END
BUT LOW LEVEL MOISTURE REMAINS IN PLACE. SOME FOG MAY BE POSSIBLE
IN THE EAST AS WINDS BECOME LIGHT. LOWS IN THE LOW TO MID 50S.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 230 PM MONDAY...
AS SURFACE SYSTEM MOVES OFFSHORE EARLY WEDNESDAY...WARM AIR WILL BE
SPREADING NORTH DUE TO SUBTROPICAL RIDGING INTO THE SOUTHERN PLAINS
AND WESTERN GULF STATES. HIGHS WEDNESDAY WILL BE 15 TO 20 DEGREES
ABOVE NORMAL...UPPER 70S OVER MOST OF THE AREA. MOISTURE WILL BE
BUILDING NORTH INTO THE TENNESSEE VALLEY AND POOLING ON THE WESTERN
SLOPES AS THE RIDGE HOLDS TIGHT THROUGH THURSDAY...INSTABILITY WILL
BE MINIMAL AND CAPPED...PROVIDING ANOTHER WARM DRY DAY WITH HIGHS IN
THE UPPER 70S TO LOWER 80S AFTER MILD MORNING LOWS IN THE LOWER 50S.
A MID LEVEL WAVE ORIGINATING IN THE SOUTHERN PLAINS WILL BE
DAMPENING THE RIDGE AMPLITUDE WITH WEAK SURFACE HIGH PRESSURE
SHIFTING OFFSHORE. THIS WILL PRODUCE A SLIGHT CHANCE OF SHOWERS
THURSDAY NIGHT...WITH A LITTLE BETTER CHANCES ON FRIDAY AS A WEAK
SURFACE FRONT EDGES VERY SLOWLY SOUTH AND EAST INTO THE MID ATLANTIC
REGION. PROGGED INSTABILITY IS SUFFICIENT FOR THUNDER GIVEN THE LOW
LEVEL FORCING AS HIGHS FRIDAY WILL STILL BE ON THE WARM SIDE...MID
TO UPPER 70S.
THE SURFACE FRONT WILL SAG FURTHER SOUTH ON SATURDAY AS LOW PRESSURE
AREA DEVELOPS OFF THE MID ATLANTIC COAST...WILL MAINTAIN SLIGHT
CHANCE TO CHANCE POPS ACROSS THE AREA THROUGH SATURDAY...AGAIN WITH
A CHANCE OF THUNDER GIVEN THE WARM AIRMASS AND POTENTIAL FOR THE
FRONT TO STALL OVER THE AREA. HIGHS WILL STILL BE IN THE MID TO
UPPER 70S.
THE FRONTS WILL BE SHOVED SOUTH OF THE AREA...SATURDAY NIGHT OR
SUNDAY AND WILL MAINTAIN SLIGHT CHANCES TO COVER THE TIMING
UNCERTAINTY. HIGH PRESSURE WILL WEDGE DOWN THE COAST SUNDAY/MONDAY
AND WILL TAPER OFF THE POPS SUNDAY NIGHT AND LEAVE MONDAY DRY FOR
NOW. HIGHS SUNDAY WILL BE IN THE LOW TO MID 70S WITH COOLER TEMPS IN
THE NORTHEAST WITH LINGERING CLOUD COVERAGE AND COOL AIR WEDGING
IN...WITH HIGHS ON MONDAY A TOUCH COOLER...LOWER 70S ACROSS THE
AREA.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 215 PM MONDAY...
24-HR TAF PERIOD:
VFR CONDITIONS ARE EXPECTED TO PREDOMINATE THROUGH 00Z THIS
EVENING...WITH SUB-VFR CONDITIONS POSSIBLE OVERNIGHT INTO TUESDAY.
VFR CEILINGS BETWEEN 3000-5000 FT WERE OBSERVED OVER MOST OF CENTRAL
NC AS OF 18Z THIS AFTERNOON. EXPECT CEILINGS TO REMAIN VFR OR
BORDERLINE MVFR AT BEST THROUGH 00Z THIS EVENING. TONIGHT...AN UPPER
LEVEL DISTURBANCE APPROACHING THE AREA FROM THE SOUTHWEST MAY HELP
ISOLD/SCT SHOWER ACTIVITY DEVELOP ACROSS THE AREA...THOUGH ENOUGH
UNCERTAINTY REMAINS TO PRECLUDE MENTION OF SHOWERS IN THE 18Z TAF
ISSUANCE. ADDITIONALLY...SOUTHWESTERLY RETURN FLOW AND WARM
ADVECTION IN THE LOWER LEVELS COULD RESULT IN THE DEVELOPMENT OF
MVFR/IFR CEILINGS ACROSS PORTIONS OF THE AREA OVERNIGHT. ALTHOUGH
SUB-VFR CONDITIONS WILL BE POSSIBLE EVERYWHERE...AT THIS TIME THE
BEST CHANCE THROUGH 12Z TUE APPEARS TO BE AT THE INT/GSO/RDU TAF
SITES. AFTER SUNRISE TUESDAY...THE FAY/RWI TAF SITES WILL HAVE THE
RELATIVE BEST CHANCE OF ISOLD/SCT SHOWER ACTIVITY AND SUB-VFR
CEILINGS. AN ISOLD THUNDERSTORM CANNOT BE RULED OUT AT FAY/RWI NEAR
OR PRIOR TO 18Z TUE. WINDS WILL BE SOUTHWEST AT ~10 KT THIS
AFTERNOON...WEAKENING TO ~5 KT OVERNIGHT...INCREASING TO ~10 KT
AGAIN ON TUE.
LOOKING AHEAD:
SUB-VFR CEILINGS OR FOG WILL BE POSSIBLE TUE NIGHT GIVEN MID/UPPER
LEVEL DRYING (CLEARING SKIES) IN THE PRESENCE OF A MOIST BOUNDARY
LAYER AND LIGHT/CALM WINDS. EXPECT VFR CONDITIONS TO PREVAIL WED
THROUGH THU IN ASSOC/W HIGH PRESSURE AND A RELATIVELY DRIER AIRMASS
IN PLACE. AFTER A BRIEF POTENTIAL FOR FOG FRIDAY MORNING...SHOWERS
AND STORMS WILL BE POSSIBLE FRI/FRI NIGHT AND POSSIBLY INTO SAT IN
ASSOC/W AN UPPER LEVEL DISTURBANCE AND SURFACE TROUGH PROGGED TO
PROGRESS THROUGH THE AREA. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...SMITH
LONG TERM...MLM
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
215 PM EDT MON MAR 12 2012
.SYNOPSIS...
HIGH PRESSURE CENTERED OFFSHORE WILL CONTINUE TO EXTEND WESTWARD
INTO THE CAROLINAS THROUGH TONIGHT. A WEAK SURFACE TROUGH AND UPPER
LEVEL DISTURBANCE WILL PROGRESS INTO THE AREA FROM THE WEST ON
TUESDAY. A GENERAL WARMING TREND IS EXPECTED THROUGH MID-WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 215 PM MONDAY...
THIS AFTERNOON:
THE PROGRESSIVE UPPER LOW CURRENTLY IN THE NORTHERN MS RIVER VALLEY
WILL TRACK NORTHEAST INTO ONTARIO TODAY...WHILE ADDITIONAL SHORTWAVE
ENERGY CURRENTLY OVER SASKATCHEWAN/MONTANA PROGRESSES EAST TOWARD
MANITOBA. HEIGHT FALLS (ASSOC/W THE AFOREMENTIONED UPPER LOW) OVER
THE OH VALLEY/MID-ATLANTIC WILL PUSH THE H5 RIDGE OFFSHORE
TODAY...WITH INCREASINGLY WESTERLY FLOW ALOFT OVER CENTRAL NC. A
MINOR SHORTWAVE WAS PRESENT UPSTREAM OVER OKLAHOMA AT 15Z...AND IS
PROGGED TO PROGRESS EAST INTO THE WESTERN TN VALLEY BY 00Z THIS
EVENING. THE LATEST RUC MODEL DATA SHOWED A MID-LEVEL VORTICITY
MAXIMUM OVER THE DEEP SOUTH AT 15Z...APPARENTLY EMANATING FROM DEEP
CONVECTION/STRONG MID-LEVEL LATENT HEATING PRESENT OVER THE LA/MS
GULF COAST THIS MORNING...AND THE RUC SHOWS THIS FEATURE PROGRESSING
NORTHEAST INTO GA/UPSTATE SC/WESTERN NC BY 00Z THIS EVENING. IN THE
LOWER LEVELS...A 5-10 KT SOUTHERLY RETURN FLOW WILL PREVAIL OVER THE
AREA...ON THE WESTERN PERIPHERY OF THE LOW-LEVEL RIDGE AXIS NOW
CENTERED OFFSHORE THE CAROLINA COAST. W/REGARD TO PRECIP CHANCES...
LITTLE OR NO FORCING FOR ASCENT WILL BE PRESENT THIS AFTERNOON...
ASIDE FROM VERY WEAK/BROAD WARM ADVECTION ASSOC/W SOUTHERLY RETURN
FLOW. INCREASING MID/UPPER LEVEL CLOUD COVER (LIMITING INSOLATION IN
THE WEST) AND A LINGERING MID-LEVEL SUBSIDENCE INVERSION (ASSOC/W
THE DEPARTING H5 RIDGE AXIS IN THE EAST) SHOULD SIGNIFICANTLY HAMPER
ANY DIURNAL DESTABILIZATION THIS AFTERNOON...WITH VERY LITTLE OR NO
AVAILABLE INSTABILITY. AS A RESULT...EXPECT A DRY FORECAST THROUGH
00Z THIS EVENING. HIGHS WILL PRIMARILY DEPEND ON THE TIMING AND
COVERAGE OF MID/UPPER LEVEL CLOUD COVER SLOWLY PROGRESSING INTO THE
AREA FROM THE WEST. WILL FCST HIGHS RANGING FROM THE MID/UPPER 60S
(W/NW PIEDMONT) TO UPPER 60S/LOWER 70S ELSEWHERE.
TONIGHT:
UNCERTAINTY INCREASES TONIGHT...PRIMARILY WITH THE PRECIPITATION
FORECAST. FORCING FOR ASCENT OVER CENTRAL NC OVERNIGHT WILL
GENERALLY BE LIMITED TO WEAK/BROAD MID-LEVEL HEIGHT FALLS AND
LOW-LEVEL WARM ADVECTION. W/REGARD TO THERMODYNAMICS...WEAK
MID-LEVEL LAPSE RATES AND BAD DIURNAL TIMING WILL CONTRIBUTE TO VERY
LITTLE OR NO AVAILABLE INSTABILITY OVERNIGHT. THE ABOVE ALONE WOULD
ARGUE FOR VERY LITTLE OR NO CHANCE OF SHOWER ACTIVITY OVERNIGHT...
AND VIRTUALLY NO CHANCE OF THUNDER. HOWEVER...THE MID-LEVEL
VORTICITY MAXIMUM THAT DEVELOPED IN ASSOC/W DEEP CONVECTION UPSTREAM
OF THE AREA THIS MORNING IS PROGGED TO APPROACH THE WEST/SW PIEDMONT
BY ~00Z...PROGRESSING THROUGH CENTRAL NC OVERNIGHT. DESPITE POOR
THERMODYNAMICS AND WEAK BACKGROUND/SYNOPTIC ASCENT...DPVA ASSOC/W
THIS FEATURE WILL PROVIDE ADDITIONAL/FOCUSED FORCING...AND ISOLD/SCT
SHOWER ACTIVITY WILL CERTAINLY BE POSSIBLE. THE LATEST 12Z WRF-NMM
SIMULATED REFLECTIVITY PRODUCT IS MORE ROBUST THAN THE 00Z RUN IN
SHOWING SHOWER ACTIVITY DEVELOPING OVERNIGHT IN ASSOC/W THIS FEATURE.
ADDITIONALLY...THE SHORTWAVE CURRENTLY IN OKLAHOMA WILL APPROACH THE
SOUTHERN APPALACHIANS BY ~12Z TUE...AND SOME WEAK AMPLIFICATION WILL
BE POSSIBLE AS ADDITIONAL UPPER LEVEL ENERGY PROGRESSES FROM THE
DESERT SOUTHWEST INTO THE TN VALLEY. THIS COULD PROVIDE ADDITIONAL
FORCING FOR ASCENT FROM THE WEST CLOSE TO SUNRISE TUE MORNING...
ALTHOUGH THE LATEST GUIDANCE CONTINUES TO SUGGEST THE BEST FORCING
ASSOC/W THE SECOND WAVE WILL MOST LIKELY OCCUR AFTER SUNRISE...
DURING THE DAY TUE. WITH THE ABOVE IN MIND...FEEL THAT A SMALL
INCREASE IN PRECIP CHANCES IS WARRANTED OVERNIGHT...AND WILL
INDICATE A 30% CHANCE OF SHOWERS EVERYWHERE. DESPITE THE PRESENCE OF
AN UPPER LEVEL DISTURBANCE...GIVEN POOR DIURNAL TIMING AND WEAK/
INCREASINGLY MOIST ADIABATIC LAPSE RATES...LITTLE IF ANY INSTABILITY
IS EXPECTED...AND WILL LEAVE OUT MENTION OF THUNDER. WITH MOSTLY
CLOUDY OR OVERCAST SKIES...EXPECT LOWS MUCH WARMER THAN IN RECENT
DAYS...IN THE LOWER/MID 50S. -VINCENT
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM MONDAY...
OVERNIGHT SHOWERS SHOULD BE MOVING INTO THE NORTHERN COASTAL PLAIN
BY AROUND 12Z TUESDAY MORNING AS THE FIRST ROUND OF FORCING
ASSOCIATED WITH A SHORTWAVE CROSSING THE GREAT LAKES MOVES OFF THE
MID ATLANTIC COAST. WESTERLY MID LEVEL FLOW BRING DRIER MID LEVEL
AIR ACROSS THE CWA DURING THE DAY...WITH A WEAK LEE TROUGH
DEVELOPING OVER THE WESTERN PIEDMONT/FOOTHILLS. A SECOND...LOW
AMPLITUDE UPPER TROUGH/DISTURBANCE IS THEN FORECAST TO CROSS THE
AREA BETWEEN 15 AND 21Z. BECAUSE THE ORIGINAL COLD FRONT WILL
ESSENTIALLY WASH OUT AS IT CROSS THE MOUNTAINS...LOW LEVEL MOISTURE
WILL CHANGE VERY LITTLE DURING THE DAY TUESDAY. STRONG HEATING
WILL ALLOW TEMPS TO RISE INTO THE LOW TO MID 70S WITH DEWPOINTS
HOLDING IN THE MID 50S. THIS DAYTIME HEATING COMBINED WITH SLIGHTLY
STEEPER MID LEVEL LAPSE RATES SHOULD LEAD TO ANOTHER ROUND OF
ISOLATED SHOWERS...FOCUSED MAINLY NEAR THE LEE TROUGH AND AIDED BY
THE AFOREMENTIONED WEAK UPPER TROUGH PASSAGE. THE MUCH DRIER MID
LEVEL AIR WILL LIMIT COVERAGE...BUT 400-800 J/KG MAY SUPPORT A FEW
ISOLATED THUNDERSTORMS OVER THE WESTERN PIEDMONT. WEAK DEEP LAYER
SHEAR AND THIN CAPE PROFILES SHOULD PRECLUDE ANY SEVERE STORMS...BUT
DOWNDRAFT CAPE COULD CLIMB INTO THE 500-1000 J/KG RANGE AND SUPPORT
SOME ENHANCED WIND GUSTS. BASED ON THE LIMITED COVERAGE
EXPECTED...WE WILL CONTINUE THE SLIGHT CHANCE POP ADVERTISED.
ANOTHER MILD NIGHT EXPECTED TUESDAY NIGHT AS SHOWERS COME TO AN END
BUT LOW LEVEL MOISTURE REMAINS IN PLACE. SOME FOG MAY BE POSSIBLE
IN THE EAST AS WINDS BECOME LIGHT. LOWS IN THE LOW TO MID 50S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 235 AM MONDAY...
FOR WEDNESDAY/WEDNESDAY NIGHT: WHAT IS LEFT OF THE WEAK SURFACE
TROUGH WILL SETTLE OVER THE SOUTHEAST CWA WEDNESDAY MORNING.
LINGERING HIGHER SURFACE DEW POINTS ALONG AND SOUTHEAST OF THIS
FRONTAL ZONE ALONG WITH LIMITED MIXING SHOULD YIELD PATCHY STRATUS
ACROSS THE EASTERN/SOUTHERN CWA EARLY WEDNESDAY MORNING... SLOWLY
MIXING OUT AND DISSIPATING BY LATE MORNING DUE TO THE DRY AIR ABOVE
850 MB. THE MID LEVEL LOW WILL MOVE SLOWLY FROM SOUTHERN QUEBEC
ACROSS MAINE AND OFF ITS COAST BY WEDNESDAY NIGHT... ALLOWING FOR
JUST A SUBTLE RISE IN MID LEVEL THICKNESSES OVER NC. DESPITE THE
LACK OF STRONG SUBSIDENCE ALOFT HOWEVER... THE MID AND UPPER LEVELS
WILL BE QUITE DRY AND THUS EXPECT PLENTY OF SUNSHINE WITH ONLY
SCATTERED FLAT STRATOCUMULUS FROM LATE MORNING ONWARD. THEN AFTER
NIGHTFALL... SURFACE WINDS WILL REMAIN VERY LIGHT WITH A LINGERING
WEAK SURFACE BOUNDARY EVIDENT OVER THE SOUTHEAST CWA. THE GFS
RETAINS GREATER LOW LEVEL MOISTURE THAN THE NAM WITH HIGHER 850 MB
THETA-E... WHICH RESULTS IN THE GFS BRINGING BROKEN MID CLOUDS OVER
THE WESTERN AND NORTHERN CWA WEDNESDAY NIGHT. THIS IS CERTAINLY
POSSIBLE GIVEN THE WEAK BUT STILL DISTINCT 850 MB WARM FRONTAL ZONE
OVER VA/NE NC AND THE POTENTIAL FOR CONVECTION UPSTREAM OVER THE MID
MISS VALLEY INTO THE OHIO VALLEY. WILL BRING IN AT LEAST SCATTERED
CLOUDS WEDNESDAY NIGHT NORTH. MODEL-PREDICTED THICKNESSES WILL BE
40+ METERS ABOVE SEASONAL NORMALS... SUPPORTING WARM FORECAST HIGHS
OF 76-80. LOWS 50-54 UNDER MOSTLY CLEAR TO PARTLY CLOUDY SKIES.
FOR THURSDAY/THURSDAY NIGHT: THE VERY WEAK SURFACE HIGH CENTERED TO
OUR NORTH WEDNESDAY NIGHT SHIFTS EASTWARD AND OFFSHORE THURSDAY...
AND THE ENSUING SOUTHEASTERLY/SOUTHERLY RETURN FLOW WILL BRING
INCREASING AMOUNTS OF LOW LEVEL MOISTURE INTO CENTRAL NC. BUT THE
GFS/ECMWF BRING THE MID LEVEL RIDGE AXIS OVERHEAD THURSDAY THROUGH
THURSDAY NIGHT WITH ENOUGH DRY AIR ALOFT TO KEEP THE FORECAST DRY...
ALBEIT WITH SCATTERED TO BRIEFLY BROKEN FLAT CUMULUS IN THE
AFTERNOON. HIGHS IN THE UPPER 70S AND LOWS IN THE LOWER-MID 50S.
FOR FRIDAY THROUGH SUNDAY: CONTINUED VERY WARM... BUT THE CHANCES
FOR AFTERNOON/EVENING CONVECTION WILL INCREASE A BIT. THE MID LEVEL
RIDGE AXIS DROPS JUST TO OUR SOUTHEAST FRIDAY AND MODELS DEPICT
MINOR DISTURBANCES TRACKING TOWARD AND INTO THE REGION WITHIN THE
FLATTENING WSW FLOW ALOFT. GFS/ECMWF SHOW ONE SUCH WEAK PERTURBATION
APPROACHING THE SOUTHERN APPALACHIANS AND INSTIGATING CONVECTION
FRIDAY AFTERNOON OVER THE MOUNTAINS/FOOTHILLS AND WRN PIEDMONT...
ALONG A SOUTH-SOUTHWESTERLY 20-25 KT 850 MB JET AND A WEAK LEE
SURFACE TROUGH JUST EAST OF THE MOUNTAINS. GIVEN THE SHIFT IN 700 MB
WINDS FROM DRY NORTHWESTERLY TO MOIST SOUTHWESTERLY AS THE RIDGE
AXIS PIVOTS ESE THROUGH CENTRAL NC... WILL RETAIN A CHANCE OF
SHOWERS AND PERHAPS A STORM OR TWO FRIDAY AFTERNOON INTO THE NIGHT
OVER THE NORTHERN AND WESTERN CWA. DEEP MID LEVEL LONGWAVE TROUGHING
CONTINUES TO DIG OVER THE WEST COAST AND ROCKIES OVER THE WEEKEND...
KEEPING A PREVAILING MEAN RIDGE OVER THE GULF AND SOUTHEAST STATES
THROUGH SUNDAY. LOW LEVEL MOISTURE WILL INCREASE STEADILY OVER NC
WITH THE PERSISTENT CARIBBEAN-SOURCE SE/S FLOW... WHILE THE EASTWARD
SHIFT OF THE 700 MB ANTICYCLONE CENTER WILL ALLOW WEST GULF MOISTURE
RIDING AROUND THE RIDGE TO WORK INTO NC FROM THE WSW. SINCE THE
RIDGE ALOFT WILL NOT BE PARTICULARLY STRONG AND WITH STRONG
SUBSIDENCE LACKING... THE SCENARIO OF INCREASING DIURNAL CONVECTION
IS REASONABLE... PARTICULARLY CONSIDERING THE RISING PRECIPITABLE
WATER TO 200-250% OF NORMAL. WILL HAVE CHANCE POPS SATURDAY THROUGH
SUNDAY... MAINLY IN THE AFTERNOON AND EVENING. WEAK STEERING WILL
SUPPORT SLOW-MOVING CELLS WITH ANY SHOWERS OR STORMS WHICH DEVELOP.
THICKNESSES HOLD WELL ABOVE NORMAL... SUPPORTING HIGHS IN THE MID
70S TO NEAR 80 AND LOWS MOSTLY IN THE MID 50S. -GIH
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 215 PM MONDAY...
24-HR TAF PERIOD:
VFR CONDITIONS ARE EXPECTED TO PREDOMINATE THROUGH 00Z THIS
EVENING...WITH SUB-VFR CONDITIONS POSSIBLE OVERNIGHT INTO TUESDAY.
VFR CEILINGS BETWEEN 3000-5000 FT WERE OBSERVED OVER MOST OF CENTRAL
NC AS OF 18Z THIS AFTERNOON. EXPECT CEILINGS TO REMAIN VFR OR
BORDERLINE MVFR AT BEST THROUGH 00Z THIS EVENING. TONIGHT...AN UPPER
LEVEL DISTURBANCE APPROACHING THE AREA FROM THE SOUTHWEST MAY HELP
ISOLD/SCT SHOWER ACTIVITY DEVELOP ACROSS THE AREA...THOUGH ENOUGH
UNCERTAINTY REMAINS TO PRECLUDE MENTION OF SHOWERS IN THE 18Z TAF
ISSUANCE. ADDITIONALLY...SOUTHWESTERLY RETURN FLOW AND WARM
ADVECTION IN THE LOWER LEVELS COULD RESULT IN THE DEVELOPMENT OF
MVFR/IFR CEILINGS ACROSS PORTIONS OF THE AREA OVERNIGHT. ALTHOUGH
SUB-VFR CONDITIONS WILL BE POSSIBLE EVERYWHERE...AT THIS TIME THE
BEST CHANCE THROUGH 12Z TUE APPEARS TO BE AT THE INT/GSO/RDU TAF
SITES. AFTER SUNRISE TUESDAY...THE FAY/RWI TAF SITES WILL HAVE THE
RELATIVE BEST CHANCE OF ISOLD/SCT SHOWER ACTIVITY AND SUB-VFR
CEILINGS. AN ISOLD THUNDERSTORM CANNOT BE RULED OUT AT FAY/RWI NEAR
OR PRIOR TO 18Z TUE. WINDS WILL BE SOUTHWEST AT ~10 KT THIS
AFTERNOON...WEAKENING TO ~5 KT OVERNIGHT...INCREASING TO ~10 KT
AGAIN ON TUE.
LOOKING AHEAD:
SUB-VFR CEILINGS OR FOG WILL BE POSSIBLE TUE NIGHT GIVEN MID/UPPER
LEVEL DRYING (CLEARING SKIES) IN THE PRESENCE OF A MOIST BOUNDARY
LAYER AND LIGHT/CALM WINDS. EXPECT VFR CONDITIONS TO PREVAIL WED
THROUGH THU IN ASSOC/W HIGH PRESSURE AND A RELATIVELY DRIER AIRMASS
IN PLACE. AFTER A BRIEF POTENTIAL FOR FOG FRIDAY MORNING...SHOWERS
AND STORMS WILL BE POSSIBLE FRI/FRI NIGHT AND POSSIBLY INTO SAT IN
ASSOC/W AN UPPER LEVEL DISTURBANCE AND SURFACE TROUGH PROGGED TO
PROGRESS THROUGH THE AREA. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...SMITH
LONG TERM...HARTFIELD
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1216 PM EDT MON MAR 12 2012
.SYNOPSIS...
HIGH PRESSURE CENTERED OFFSHORE WILL CONTINUE TO EXTEND WESTWARD
INTO THE CAROLINAS THROUGH TONIGHT. A WEAK SURFACE TROUGH AND UPPER
LEVEL DISTURBANCE WILL PROGRESS INTO THE AREA FROM THE WEST ON
TUESDAY. A GENERAL WARMING TREND IS EXPECTED THROUGH MID-WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1215 PM MONDAY...
TODAY:
THE PROGRESSIVE UPPER LOW CURRENTLY IN THE NORTHERN MS RIVER VALLEY
WILL TRACK NORTHEAST INTO ONTARIO TODAY...WHILE ADDITIONAL SHORTWAVE
ENERGY CURRENTLY OVER SASKATCHEWAN/MONTANA PROGRESSES EAST TOWARD
MANITOBA. HEIGHT FALLS (ASSOC/W THE AFOREMENTIONED UPPER LOW) OVER
THE OH VALLEY/MID-ATLANTIC WILL PUSH THE H5 RIDGE OFFSHORE
TODAY...WITH INCREASINGLY WESTERLY FLOW ALOFT OVER CENTRAL NC. A
MINOR SHORTWAVE WAS PRESENT UPSTREAM OVER OKLAHOMA AT 15Z...AND IS
PROGGED TO PROGRESS EAST INTO THE WESTERN TN VALLEY BY 00Z THIS
EVENING. THE LATEST RUC MODEL DATA SHOWED A MID-LEVEL VORTICITY
MAXIMUM OVER THE DEEP SOUTH AT 15Z...APPARENTLY EMANATING FROM DEEP
CONVECTION/STRONG MID-LEVEL LATENT HEATING PRESENT OVER THE LA/MS
GULF COAST THIS MORNING...AND THE RUC SHOWS THIS FEATURE PROGRESSING
NORTHEAST INTO GA/UPSTATE SC/WESTERN NC BY 00Z THIS EVENING. IN THE
LOWER LEVELS...A 5-10 KT SOUTHERLY RETURN FLOW WILL PREVAIL OVER THE
AREA...ON THE WESTERN PERIPHERY OF THE LOW-LEVEL RIDGE AXIS NOW
CENTERED OFFSHORE THE CAROLINA COAST. W/REGARD TO PRECIP CHANCES...
LITTLE OR NO FORCING FOR ASCENT WILL BE PRESENT THIS AFTERNOON...
ASIDE FROM VERY WEAK/BROAD WARM ADVECTION ASSOC/W SOUTHERLY RETURN
FLOW. INCREASING MID/UPPER LEVEL CLOUD COVER (LIMITING INSOLATION IN
THE WEST) AND A LINGERING MID-LEVEL SUBSIDENCE INVERSION (ASSOC/W
THE DEPARTING H5 RIDGE AXIS IN THE EAST) SHOULD SIGNIFICANTLY HAMPER
ANY DIURNAL DESTABILIZATION THIS AFTERNOON...WITH VERY LITTLE OR NO
AVAILABLE INSTABILITY. AS A RESULT...EXPECT A DRY FORECAST THROUGH
00Z THIS EVENING. HIGHS WILL PRIMARILY DEPEND ON THE TIMING AND
COVERAGE OF MID/UPPER LEVEL CLOUD COVER SLOWLY PROGRESSING INTO THE
AREA FROM THE WEST. WILL FCST HIGHS RANGING FROM THE MID/UPPER 60S
(W/NW PIEDMONT) TO UPPER 60S/LOWER 70S ELSEWHERE.
TONIGHT:
UNCERTAINTY IN THE FORECAST INCREASES TONIGHT...PRIMARILY WITH THE
PRECIPITATION FORECAST. FORCING FOR ASCENT OVER CENTRAL NC OVERNIGHT
WILL PRIMARILY BE LIMITED TO WEAK/BROAD MID-LEVEL HEIGHT FALLS AND
LOW-LEVEL WARM ADVECTION. W/REGARD TO THERMODYNAMICS...WEAK
MID-LEVEL LAPSE RATES AND BAD DIURNAL TIMING WILL CONTRIBUTE TO VERY
LITTLE OR NO AVAILABLE INSTABILITY OVERNIGHT. THE ABOVE ALONE WOULD
ARGUE FOR VERY LITTLE OR NO CHANCE OF SHOWER ACTIVITY OVERNIGHT...
AND VIRTUALLY NO CHANCE OF THUNDER. HOWEVER...THE MID-LEVEL
VORTICITY MAXIMUM THAT DEVELOPED IN ASSOC/W DEEP CONVECTION UPSTREAM
OF THE AREA THIS MORNING IS PROGGED TO APPROACH THE WEST/SW PIEDMONT
BY ~00Z...PROGRESSING THROUGH CENTRAL NC BETWEEN 00-06Z. DESPITE
POOR THERMODYNAMICS AND WEAK BACKGROUND/ SYNOPTIC ASCENT...DPVA
ASSOC/W THIS FEATURE WILL PROVIDE ADDITIONAL FORCING BETWEEN ROUGHLY
SUNSET AND MIDNIGHT...AND ISOLD SHOWER ACTIVITY WILL AT LEAST BE
POSSIBLE...THOUGH THE 00Z WRF-NMM SIMULATED REFLECTIVITY PRODUCT
SHOWS NO PRECIP OVER CENTRAL NC IN THAT TIME FRAME. ADDITIONALLY...
BY THE TIME THE SHORTWAVE CURRENTLY IN OKLAHOMA APPROACHES THE
SOUTHERN APPALACHIANS (~12Z TUE)...SOME WEAK AMPLIFICATION WILL BE
POSSIBLE AS ADDITIONAL UPPER LEVEL ENERGY PROGRESSES FROM THE DESERT
SOUTHWEST INTO THE TN VALLEY. THIS COULD PROVIDE ADDITIONAL FORCING
FOR ASCENT FROM THE WEST CLOSE TO SUNRISE TUE MORNING...ALTHOUGH THE
LATEST GUIDANCE SUGGESTS THE BEST FORCING ASSOC/W THE AFOREMENTIONED
FEATURE WILL MOST LIKELY OCCUR AFTER SUNRISE...DURING THE DAY TUE.
THE 00Z WRF-NMM KEEPS CENTRAL NC DRY THROUGH 09Z...THEN SHOWS
ISOLD/SCT SHOWER ACTIVITY DEVELOPING OVER THE NORTHWESTERN HALF OF
THE AREA RIGHT AROUND 12Z. WITH THE ABOVE IN MIND...WILL INDICATE A
SLIGHT TO LOW CHANCE (20-30%) OF SHOWERS OVER MOST OF THE AREA
BETWEEN 00-06Z...HIGHEST (30%) IN THE SW PIEDMONT...AND WILL KEEP A
SLIGHT CHANCE OF SHOWERS OVER THE ENTIRE AREA THROUGH THE REMAINDER
OF THE NIGHT...RELATIVE BEST CHANCE NEAR OR WEST OF HWY 1 BETWEEN
09-12Z. WILL LEAVE OUT MENTION OF THUNDER AS MENTIONED ABOVE. WITH
MOSTLY CLOUDY OR OVERCAST SKIES...EXPECT LOWS MUCH WARMER THAN IN
RECENT DAYS...IN THE LOWER/MID 50S. -VINCENT
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM MONDAY...
OVERNIGHT SHOWERS SHOULD BE MOVING INTO THE NORTHERN COASTAL PLAIN
BY AROUND 12Z TUESDAY MORNING AS THE FIRST ROUND OF FORCING
ASSOCIATED WITH A SHORTWAVE CROSSING THE GREAT LAKES MOVES OFF THE
MID ATLANTIC COAST. WESTERLY MID LEVEL FLOW BRING DRIER MID LEVEL
AIR ACROSS THE CWA DURING THE DAY...WITH A WEAK LEE TROUGH
DEVELOPING OVER THE WESTERN PIEDMONT/FOOTHILLS. A SECOND...LOW
AMPLITUDE UPPER TROUGH/DISTURBANCE IS THEN FORECAST TO CROSS THE
AREA BETWEEN 15 AND 21Z. BECAUSE THE ORIGINAL COLD FRONT WILL
ESSENTIALLY WASH OUT AS IT CROSS THE MOUNTAINS...LOW LEVEL MOISTURE
WILL CHANGE VERY LITTLE DURING THE DAY TUESDAY. STRONG HEATING
WILL ALLOW TEMPS TO RISE INTO THE LOW TO MID 70S WITH DEWPOINTS
HOLDING IN THE MID 50S. THIS DAYTIME HEATING COMBINED WITH SLIGHTLY
STEEPER MID LEVEL LAPSE RATES SHOULD LEAD TO ANOTHER ROUND OF
ISOLATED SHOWERS...FOCUSED MAINLY NEAR THE LEE TROUGH AND AIDED BY
THE AFOREMENTIONED WEAK UPPER TROUGH PASSAGE. THE MUCH DRIER MID
LEVEL AIR WILL LIMIT COVERAGE...BUT 400-800 J/KG MAY SUPPORT A FEW
ISOLATED THUNDERSTORMS OVER THE WESTERN PIEDMONT. WEAK DEEP LAYER
SHEAR AND THIN CAPE PROFILES SHOULD PRECLUDE ANY SEVERE STORMS...BUT
DOWNDRAFT CAPE COULD CLIMB INTO THE 500-1000 J/KG RANGE AND SUPPORT
SOME ENHANCED WIND GUSTS. BASED ON THE LIMITED COVERAGE
EXPECTED...WE WILL CONTINUE THE SLIGHT CHANCE POP ADVERTISED.
ANOTHER MILD NIGHT EXPECTED TUESDAY NIGHT AS SHOWERS COME TO AN END
BUT LOW LEVEL MOISTURE REMAINS IN PLACE. SOME FOG MAY BE POSSIBLE
IN THE EAST AS WINDS BECOME LIGHT. LOWS IN THE LOW TO MID 50S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 235 AM MONDAY...
FOR WEDNESDAY/WEDNESDAY NIGHT: WHAT IS LEFT OF THE WEAK SURFACE
TROUGH WILL SETTLE OVER THE SOUTHEAST CWA WEDNESDAY MORNING.
LINGERING HIGHER SURFACE DEW POINTS ALONG AND SOUTHEAST OF THIS
FRONTAL ZONE ALONG WITH LIMITED MIXING SHOULD YIELD PATCHY STRATUS
ACROSS THE EASTERN/SOUTHERN CWA EARLY WEDNESDAY MORNING... SLOWLY
MIXING OUT AND DISSIPATING BY LATE MORNING DUE TO THE DRY AIR ABOVE
850 MB. THE MID LEVEL LOW WILL MOVE SLOWLY FROM SOUTHERN QUEBEC
ACROSS MAINE AND OFF ITS COAST BY WEDNESDAY NIGHT... ALLOWING FOR
JUST A SUBTLE RISE IN MID LEVEL THICKNESSES OVER NC. DESPITE THE
LACK OF STRONG SUBSIDENCE ALOFT HOWEVER... THE MID AND UPPER LEVELS
WILL BE QUITE DRY AND THUS EXPECT PLENTY OF SUNSHINE WITH ONLY
SCATTERED FLAT STRATOCUMULUS FROM LATE MORNING ONWARD. THEN AFTER
NIGHTFALL... SURFACE WINDS WILL REMAIN VERY LIGHT WITH A LINGERING
WEAK SURFACE BOUNDARY EVIDENT OVER THE SOUTHEAST CWA. THE GFS
RETAINS GREATER LOW LEVEL MOISTURE THAN THE NAM WITH HIGHER 850 MB
THETA-E... WHICH RESULTS IN THE GFS BRINGING BROKEN MID CLOUDS OVER
THE WESTERN AND NORTHERN CWA WEDNESDAY NIGHT. THIS IS CERTAINLY
POSSIBLE GIVEN THE WEAK BUT STILL DISTINCT 850 MB WARM FRONTAL ZONE
OVER VA/NE NC AND THE POTENTIAL FOR CONVECTION UPSTREAM OVER THE MID
MISS VALLEY INTO THE OHIO VALLEY. WILL BRING IN AT LEAST SCATTERED
CLOUDS WEDNESDAY NIGHT NORTH. MODEL-PREDICTED THICKNESSES WILL BE
40+ METERS ABOVE SEASONAL NORMALS... SUPPORTING WARM FORECAST HIGHS
OF 76-80. LOWS 50-54 UNDER MOSTLY CLEAR TO PARTLY CLOUDY SKIES.
FOR THURSDAY/THURSDAY NIGHT: THE VERY WEAK SURFACE HIGH CENTERED TO
OUR NORTH WEDNESDAY NIGHT SHIFTS EASTWARD AND OFFSHORE THURSDAY...
AND THE ENSUING SOUTHEASTERLY/SOUTHERLY RETURN FLOW WILL BRING
INCREASING AMOUNTS OF LOW LEVEL MOISTURE INTO CENTRAL NC. BUT THE
GFS/ECMWF BRING THE MID LEVEL RIDGE AXIS OVERHEAD THURSDAY THROUGH
THURSDAY NIGHT WITH ENOUGH DRY AIR ALOFT TO KEEP THE FORECAST DRY...
ALBEIT WITH SCATTERED TO BRIEFLY BROKEN FLAT CUMULUS IN THE
AFTERNOON. HIGHS IN THE UPPER 70S AND LOWS IN THE LOWER-MID 50S.
FOR FRIDAY THROUGH SUNDAY: CONTINUED VERY WARM... BUT THE CHANCES
FOR AFTERNOON/EVENING CONVECTION WILL INCREASE A BIT. THE MID LEVEL
RIDGE AXIS DROPS JUST TO OUR SOUTHEAST FRIDAY AND MODELS DEPICT
MINOR DISTURBANCES TRACKING TOWARD AND INTO THE REGION WITHIN THE
FLATTENING WSW FLOW ALOFT. GFS/ECMWF SHOW ONE SUCH WEAK PERTURBATION
APPROACHING THE SOUTHERN APPALACHIANS AND INSTIGATING CONVECTION
FRIDAY AFTERNOON OVER THE MOUNTAINS/FOOTHILLS AND WRN PIEDMONT...
ALONG A SOUTH-SOUTHWESTERLY 20-25 KT 850 MB JET AND A WEAK LEE
SURFACE TROUGH JUST EAST OF THE MOUNTAINS. GIVEN THE SHIFT IN 700 MB
WINDS FROM DRY NORTHWESTERLY TO MOIST SOUTHWESTERLY AS THE RIDGE
AXIS PIVOTS ESE THROUGH CENTRAL NC... WILL RETAIN A CHANCE OF
SHOWERS AND PERHAPS A STORM OR TWO FRIDAY AFTERNOON INTO THE NIGHT
OVER THE NORTHERN AND WESTERN CWA. DEEP MID LEVEL LONGWAVE TROUGHING
CONTINUES TO DIG OVER THE WEST COAST AND ROCKIES OVER THE WEEKEND...
KEEPING A PREVAILING MEAN RIDGE OVER THE GULF AND SOUTHEAST STATES
THROUGH SUNDAY. LOW LEVEL MOISTURE WILL INCREASE STEADILY OVER NC
WITH THE PERSISTENT CARIBBEAN-SOURCE SE/S FLOW... WHILE THE EASTWARD
SHIFT OF THE 700 MB ANTICYCLONE CENTER WILL ALLOW WEST GULF MOISTURE
RIDING AROUND THE RIDGE TO WORK INTO NC FROM THE WSW. SINCE THE
RIDGE ALOFT WILL NOT BE PARTICULARLY STRONG AND WITH STRONG
SUBSIDENCE LACKING... THE SCENARIO OF INCREASING DIURNAL CONVECTION
IS REASONABLE... PARTICULARLY CONSIDERING THE RISING PRECIPITABLE
WATER TO 200-250% OF NORMAL. WILL HAVE CHANCE POPS SATURDAY THROUGH
SUNDAY... MAINLY IN THE AFTERNOON AND EVENING. WEAK STEERING WILL
SUPPORT SLOW-MOVING CELLS WITH ANY SHOWERS OR STORMS WHICH DEVELOP.
THICKNESSES HOLD WELL ABOVE NORMAL... SUPPORTING HIGHS IN THE MID
70S TO NEAR 80 AND LOWS MOSTLY IN THE MID 50S. -GIH
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 720 AM MONDAY...
THERE IS SOME STRATUS OVER THE FOOTHILLS DRIFTING TOWARD
KINT/KGSO...AND ALSO SOME FOG OVER THE COASTAL PLAIN NEAR KFAY AND
KRWI THIS MORNING. HOWEVER... BASED ON SATELLITE AND FORECAST
SOUNDINGS IT DOES NOT APPEAR THAT EITHER SHOULD CAUSE MORE THAN A
BRIEF PERIOD OF MVFR CEILINGS OR VSBYS THROUGH 15Z. MIXING WILL THEN
ERODE THE FOG AND LIFT CEILINGS TO AT OR ABOVE 4K FT OVER THE
WESTERN PIEDMONT...LEADING TO VFR CONDITIONS WITH 5-10KT
SOUTHWESTERLY WINDS TODAY AND GUSTS TO 15-20KT AT TIMES.
DEEP LAYER MOISTURE WILL CONTINUE TO INCREASE THIS EVENING AS A COLD
FRONT APPROACHES THE MOUNTAINS FROM WEST. THE COLD FRONT IS
EXPECTED TO WEAKEN DRAMATICALLY AND MOST PRECIP ASSOCIATED WITH THE
FRONT SHOULD PASS ACROSS VA OVERNIGHT. CEILINGS ARE FORECAST TO
LOWER OVERNIGHT...WITH MVFR CONDITIONS EXPECTED TO DEVELOP AFTER
MIDNIGHT. THERE IS A SLIGHT CHANCE THAT KING/KGSO AND KRDU COULD
EXPERIENCE A SHOWER OVERNIGHT...WHICH COULD BRING CEILINGS AND VSBYS
DOWN TO MVFR OR LOWER SOONER THAN EXPECTED. THE LONE EXCEPTION IS
KFAY...WHICH MAY EXPERIENCE SOME LIMITED VSBYS AS STRATUS SHOULD
REMAIN MOSTLY NORTH OF THAT TERMINAL.
LOOKING AHEAD:
SHOWERS AND POSSIBLY AN ISOLATED THUNDERSTORM ASSOCIATED WITH A
WEAKENING COLD FRONT AND AN UPPER LEVEL DISTURBANCE WILL BE POSSIBLE
TUESDAY. THUS..SOME ADVERSE AVIATION CONDITIONS CAN BE EXPECTED
TUESDAY. FOG WILL BE POSSIBLE DURING THE PREDAWN HOURS (06-12Z)
THROUGHOUT MUCH OF THE WORK WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...SMITH
LONG TERM...HARTFIELD
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1000 PM CDT TUE MAR 13 2012
.DISCUSSION...
MADE SOME MORE WIND ADJUSTMENTS TO FAVOR THE NEAR TERM RUC TRENDS.
THERE WILL LIKELY BE BRIEF PERIODS OF STRONG GUSTS BEGINNING NEAR OR
SHORTLY BEFORE MIDNIGHT...FROM DIVIDE THROUGH GOLDEN VALLEY AND
BILLINGS COUNTIES. WITH THE BRIEF NATURE OF THE GUSTS
EXPECTED...WILL NOT ISSUED ADVISORY AT THIS TIME...BUT HANDLE WITH
SHORT TERM FORECASTS/SPECIAL WEATHER STATEMENTS AS NEEDED. GUSTS
OVER 40 MPH ARE POSSIBLE IN THE FAR WEST AND NW COUNTIES...BUT
WINDS ARE NOT EXPECTED TO BE AS STRONG BEHIND THE COLD FRONT AS IT
PROGRESSES TO THE EAST.
&&
.AVIATION...
VFR CONDITIONS EXPECTED THROUGH 15/06Z...BUT THERE WILL BE A
PERIOD OF STRONG WINDS DURING THE EARLY MORNING HOURS...ESPECIALLY
AT KISN/KMOT AND POSSIBLY KDIK. BRIEF GUSTS AROUND 40 KTS ARE
POSSIBLE. WINDS WILL DROP OFF FROM WEST TO EAST PRIOR TO SUNRISE
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION/AVIATION...RK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
951 AM CDT MON MAR 12 2012
.DISCUSSION...
RAIN CONTINUES TO BE CONCENTRATED ALONG THE MID LEVEL
FRONTOGENESIS BAND...CURRENTLY STRETCHING FROM THE SOUTHERN RED
RIVER VALLEY UP TOWARDS ROSEAU...BUT THE BAND SHOULD CONTINUE TO
PUSH SLOWLY EAST THROUGHOUT THE DAY. MADE ONLY A FEW MINOR TWEAKS
TO GOING POPS AS WHAT WE HAD CURRENTLY SEEMED TO CAPTURE THE BAND
WELL. MAIN CHANGE FOR THE MORNING UPDATE WAS TO ADD FOG TO THE
GRIDS FOR MUCH OF THE MORNING. INCLUDED A PATCHY MENTION ALONG THE
RAIN BAND BUT AREAS OF FOG JUST TO THE EAST AND WEST OF THE RAIN.
SOME AWOS SITES IN THE NORTHWEST AND SOUTHEASTERN COUNTIES ARE DOWN
TO A QUARTER OF A MILE...BUT WEBCAMS SHOW THAT COVERAGE IS NOT
WIDESPREAD. FOG SHOULD DECREASE THIS AFTERNOON AS WINDS PICK UP IN
THE WESTERN COUNTIES AND THE RAIN BAND MOVES INTO THE EAST. WILL
HOLD OFF ON ANY FOG HEADLINES AND JUST COVER WITH NOWCASTS FOR THE
TIME BEING.
&&
.AVIATION...
A BAND OF LIGHT TO MODERATE RAIN SHOWERS FROM LISBON TO GRAND FORKS
TO ROSEAU WILL CONTINUE TO MOVE NORTH AND EAST LATE THIS MORNING AND
AFTERNOON. IFR/LIFR CEILINGS WILL GRADUALLY IMPROVE FROM WEST TO
EAST THIS AFTERNOON AND EVENING. VISIBILITY WILL BE REDUCED TO 1 SM
AT TIMES IN RAIN ALONG AND EAST OF THE VALLEY...AND DOWN TO 1/4 SM IN
FOG AT KTVF AND KBJI. SOME FOG/MIST IS ALSO POSSIBLE AT OTHER TAF
SITES. AS CEILINGS IMPROVE...SOUTHERLY WINDS WILL SHIFT TO THE
NORTHWEST AND BECOME BREEZY THIS AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 335 AM CDT MON MAR 12 2012/
SHORT TERM...MAIN CONCERNS WILL BE RAIN AND QPF ALONG WITH WIND
SPEEDS TODAY. 00Z MODELS IN DECENT AGREEMENT WITH SYNOPTIC
FEATURES AND WILL USE A BLEND.
UPPER LOW WILL PROPAGATE THROUGH IOWA AND INTO THE GREAT LAKES
REGION BY THIS EVENING...WHILE ANOTHER SHORTWAVE ACROSS THE NW
CONUS WILL PROPAGATE INTO THE NORTHERN FA. THESE TWO WAVE WILL
MAKE FOR A COMPLICATED FORECAST SCENARIO. MODELS APPEAR TO BE
HINTING THAT A BAND OF MODERATE RAIN WILL SET UP SOMEWHERE ACROSS
THE FA AND SLOWLY MOVE EAST. THIS BAND WILL BE ASSOCIATED WITH
STRONG 850-700MB FRONTOGENESIS...SYMMETRIC INSTABILITY...AND PWATS
UP TOWARD 0.9 INCHES. GIVEN THE BANDING POTENTIAL...THINK THAT
LOWER RESOLUTION MODELS ARE UNDERESTIMATING QPF POTENTIAL (SHOWING
UP TO 0.25 INCHES). HIGHER RESOLUTION MODELS ARE INDICATING 0.50
TO 1.00 INCH...WHICH APPEARS POSSIBLE GIVEN THE FORCING
MECHANISMS AND AVAILABLE MOISTURE. THE MAIN QUESTION IS WHERE WILL
THE BAND SET UP...AND HOW FAR NORTH WOULD THE HIGHER RAIN TOTALS
BE. MUCH DEPENDS ON THE EXACT SPEED OF THE EACH WAVE. WILL FOLLOW
THE HRRR AND RUC WHICH APPEAR TO HAVE A HANDLE ON THE CURRENT
RADAR TRENDS. GIVEN THESE MODELS...AND CURRENT RADAR...IT APPEARS
THIS BAND OF RAIN WILL BE LOCATED FROM THE SOUTHWEST FA INTO THE
NE FA THIS MORNING. HRRR AND RUC INDICATING STRONGER FORCING
ACROSS THE SOUTHERN FA...WITH THE HIGHER QPF TOTALS ACROSS THE
SOUTHERN VALLEY. GIVEN UNCERTAINTY...WILL GO WITH AREAL AVERAGE
QPF 0.30-0.50 INCHES WITHIN THIS EXPECTED RAIN BAND (PLUS 1.0 INCH
RAINFALL WOULD LIKELY BE ISOLATED). WILL TRY TO REFINE THIS ONCE
MORE CONFIDENCE IS OBTAINED. AS THE SECOND KICKER WAVE
APPROACHES...CLEARING SHOULD MOVE THROUGH FROM WEST TO EAST BY
THIS EVENING.
MODELS INDICATE STRONG 850MB COLD AIR ADVECTION WITH WINDS 40-43
KNOTS AT THIS LEVEL ACROSS THE DEVILS LAKE BASIN BY THIS
AFTERNOON. WILL ISSUE A WIND ADVISORY FOR THIS AREA. THE COLD AIR
ADVECTION WEAKENS AS IT MOVES EAST...WHICH SHOULD KEEP ADVISORY
CONDITIONS CONFINED TO THE DEVILS LAKE BASIN. TEMPERATURE TRICKY
TODAY...BUT THINK SOME SOLAR WILL GET TEMPS INTO THE 50S VALLEY
AND WEST (40S WHERE CLOUD COVER EXPECTED MUCH OF THE DAY).
PROGRESSIVE PATTERN REMAINDER OF THE PERIOD AND TIMING WILL HAVE
AFFECT ON TEMPERATURES. APPLIED A MODEL BIAS FROM THE PAST COUPLE
DAYS FOR GUIDANCE. NO MEASURABLE PRECIP EXPECTED.
LONG TERM (THUR-SUN)...EARLY IN THE EXTENDED PERIOD MODELS IN
GOOD AGREEMENT THAT AN UPPER LOW WILL BE PASSING WELL NORTH OF THE
REGION. RESULTANT WESTERLY SURFACE FLOW WILL CONTINUE THE DRY AND
WARM WEATHER. FLAT WESTERLY FLOW GRADUALLY TRANSITIONS TO MORE
SOUTHWEST FLOW BY LATER ON FRIDAY. ECMWF SLOWER THAN THE
GFS/DGEX/GEM AND BASED ON OVERALL HEMISPHERIC PATTERN PROBABLY
BETTER.
VARIOUS ENSEMBLES IN AGREEMENT THAT BLOCKING OVER THE NORTHEAST U.S.
IN THE FORM OF VERY STRONG RIDGE WILL FAVOR DEEP TROUGH OVER EASTERN
PACIFIC/WESTERN U.S. BY SATURDAY DGEX/GFS BOTH BRING A SURGE OF
MODERATELY UNSTABLE AIR...FOR MARCH...INTO THE NORTHERN PLAINS. 45
KT 850 JET AND LI IN THE -2C TO -4C RANGE SET UP JUST AHEAD OF COLD
FRONT FORECAST TO MOVE THROUGH LATE IN THE DAY. SURFACE TD REACH THE
MID 50S WITH OPEN GULF OF MEXICO FLOW FORECAST FOR SEVERAL DAYS
AHEAD OF DEEPENING SURFACE LOW.
WHILE CLIMATOLOGICALLY NOT THE BEST TIME OF YEAR TSRA NOT UNHEARD OF
IN MID MARCH SO PUT TSRA VALLEY EAST SATURDAY AND EAST OF VALLEY
SATURDAY NIGHT. IF SLOWER ECMWF VERIFIES COULD EASILY SEE MORE
THUNDER AT END OF PERIOD.
MAX TEMPERATURES PEAK INTO THE 60S FRIDAY AND SATURDAY AHEAD OF
STRONG UPPER WAVE AND SURFACE FRONT. ATTM FORECAST TEMPERATURES TO
COOL BACK INTO THE 50S BEHIND EXPECTED FRONT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR NDZ006-007-014-015-
024.
MN...NONE.
&&
$$
JR/ROGERS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
335 AM CDT MON MAR 12 2012
.SHORT TERM...MAIN CONCERNS WILL BE RAIN AND QPF ALONG WITH WIND
SPEEDS TODAY. 00Z MODELS IN DECENT AGREEMENT WITH SYNOPTIC
FEATURES AND WILL USE A BLEND.
UPPER LOW WILL PROPAGATE THROUGH IOWA AND INTO THE GREAT LAKES
REGION BY THIS EVENING...WHILE ANOTHER SHORTWAVE ACROSS THE NW
CONUS WILL PROPAGATE INTO THE NORTHERN FA. THESE TWO WAVE WILL
MAKE FOR A COMPLICATED FORECAST SCENARIO. MODELS APPEAR TO BE
HINTING THAT A BAND OF MODERATE RAIN WILL SET UP SOMEWHERE ACROSS
THE FA AND SLOWLY MOVE EAST. THIS BAND WILL BE ASSOCIATED WITH
STRONG 850-700MB FRONTOGENESIS...SYMMETRIC INSTABILITY...AND PWATS
UP TOWARD 0.9 INCHES. GIVEN THE BANDING POTENTIAL...THINK THAT
LOWER RESOLUTION MODELS ARE UNDERESTIMATING QPF POTENTIAL (SHOWING
UP TO 0.25 INCHES). HIGHER RESOLUTION MODELS ARE INDICATING 0.50
TO 1.00 INCH...WHICH APPEARS POSSIBLE GIVEN THE FORCING
MECHANISMS AND AVAILABLE MOISTURE. THE MAIN QUESTION IS WHERE WILL
THE BAND SET UP...AND HOW FAR NORTH WOULD THE HIGHER RAIN TOTALS
BE. MUCH DEPENDS ON THE EXACT SPEED OF THE EACH WAVE. WILL FOLLOW
THE HRRR AND RUC WHICH APPEAR TO HAVE A HANDLE ON THE CURRENT
RADAR TRENDS. GIVEN THESE MODELS...AND CURRENT RADAR...IT APPEARS
THIS BAND OF RAIN WILL BE LOCATED FROM THE SOUTHWEST FA INTO THE
NE FA THIS MORNING. HRRR AND RUC INDICATING STRONGER FORCING
ACROSS THE SOUTHERN FA...WITH THE HIGHER QPF TOTALS ACROSS THE
SOUTHERN VALLEY. GIVEN UNCERTAINTY...WILL GO WITH AREAL AVERAGE
QPF 0.30-0.50 INCHES WITHIN THIS EXPECTED RAIN BAND (PLUS 1.0 INCH
RAINFALL WOULD LIKELY BE ISOLATED). WILL TRY TO REFINE THIS ONCE
MORE CONFIDENCE IS OBTAINED. AS THE SECOND KICKER WAVE
APPROACHES...CLEARING SHOULD MOVE THROUGH FROM WEST TO EAST BY
THIS EVENING.
MODELS INDICATE STRONG 850MB COLD AIR ADVECTION WITH WINDS 40-43
KNOTS AT THIS LEVEL ACROSS THE DEVILS LAKE BASIN BY THIS
AFTERNOON. WILL ISSUE A WIND ADVISORY FOR THIS AREA. THE COLD AIR
ADVECTION WEAKENS AS IT MOVES EAST...WHICH SHOULD KEEP ADVISORY
CONDITIONS CONFINED TO THE DEVILS LAKE BASIN. TEMPERATURE TRICKY
TODAY...BUT THINK SOME SOLAR WILL GET TEMPS INTO THE 50S VALLEY
AND WEST (40S WHERE CLOUD COVER EXPECTED MUCH OF THE DAY).
PROGRESSIVE PATTERN REMAINDER OF THE PERIOD AND TIMING WILL HAVE
AFFECT ON TEMPERATURES. APPLIED A MODEL BIAS FROM THE PAST COUPLE
DAYS FOR GUIDANCE. NO MEASURABLE PRECIP EXPECTED.
.LONG TERM (THUR-SUN)...EARLY IN THE EXTENDED PERIOD MODELS IN
GOOD AGREEMENT THAT AN UPPER LOW WILL BE PASSING WELL NORTH OF THE
REGION. RESULTANT WESTERLY SURFACE FLOW WILL CONTINUE THE DRY AND
WARM WEATHER. FLAT WESTERLY FLOW GRADUALLY TRANSITIONS TO MORE
SOUTHWEST FLOW BY LATER ON FRIDAY. ECMWF SLOWER THAN THE
GFS/DGEX/GEM AND BASED ON OVERALL HEMISPHERIC PATTERN PROBABLY
BETTER.
VARIOUS ENSEMBLES IN AGREEMENT THAT BLOCKING OVER THE NORTHEAST U.S.
IN THE FORM OF VERY STRONG RIDGE WILL FAVOR DEEP TROUGH OVER EASTERN
PACIFIC/WESTERN U.S. BY SATURDAY DGEX/GFS BOTH BRING A SURGE OF
MODERATELY UNSTABLE AIR...FOR MARCH...INTO THE NORTHERN PLAINS. 45
KT 850 JET AND LI IN THE -2C TO -4C RANGE SET UP JUST AHEAD OF COLD
FRONT FORECAST TO MOVE THROUGH LATE IN THE DAY. SURFACE TD REACH THE
MID 50S WITH OPEN GULF OF MEXICO FLOW FORECAST FOR SEVERAL DAYS
AHEAD OF DEEPENING SURFACE LOW.
WHILE CLIMATOLOGICALLY NOT THE BEST TIME OF YEAR TSRA NOT UNHEARD OF
IN MID MARCH SO PUT TSRA VALLEY EAST SATURDAY AND EAST OF VALLEY
SATURDAY NIGHT. IF SLOWER ECMWF VERIFIES COULD EASILY SEE MORE
THUNDER AT END OF PERIOD.
MAX TEMPERATURES PEAK INTO THE 60S FRIDAY AND SATURDAY AHEAD OF
STRONG UPPER WAVE AND SURFACE FRONT. ATTM FORECAST TEMPERATURES TO
COOL BACK INTO THE 50S BEHIND EXPECTED FRONT.
&&
.AVIATION...MVFR CIGS EXPECTED ALONG AND EAST OF THE RED RIVER
VALLEY INTO THE AFTERNOON HOURS. A BAND OF RAIN WILL SET UP ACROSS
THE AREA...AND IFR CONDITIONS POSSIBLE WITHIN THIS BAND. VFR
CONDITIONS WILL SPREAD FROM WEST TO EAST BY LATE AFTERNOON. SOUTH
WINDS WILL BECOME NORTHWEST...AND BREEZY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND ADVISORY FROM 11 AM THIS MORNING TO 6 PM CDT THIS EVENING
FOR NDZ006-007-014-015-024.
MN...NONE.
&&
$$
TG/EWENS
AREA FORECAST DISCUSSION
NWS PORTLAND OR
525 AM PDT SUN MAR 12 2012
.SYNOPSIS...A STRONG PACIFIC FRONT WILL BRING STRONG WINDS...HEAVY
RAIN AND MOUNTAIN SNOW TODAY. A SERIES OF SYSTEMS WILL MAINTAIN
DAMP AND COOL WEATHER THROUGH NEXT WEEK.
&&
.UPDATE...WE ARE ISSUING A WIND ADVISORY FOR THE VALLEY...GUSTS TO
50 MPH POSSIBLE IN THE SOUTH AND CENTRAL VALLEY...GENERALLY 45 MPH
IN THE NORTH. SEE THE LATEST NPWPQR FOR MORE DETAILS. REASONING IS
THAT THE WARM SECTOR WILL GET INTO AREAS SOUTH OF MCMINNVILLE/SALEM
BRINGING THE POTENTIAL FOR SOME GOOD GUSTS...AND A LITTLE LESS
FAVORABLE ORIENTATION TO THE PRES GRADIENT FARTHER NORTH.
MCMINNVILLE HAS A GUST TO 47 MPH...AND EUGENE AND MCMINNVILLE HAVE
SUSTAINED WINDS OF 30 MPH. PEAK WINDS WILL BE THIS
MORNING...LINGERING SOUTH IN THE AFTERNOON. HEADLINES ARE UPDATED
BELOW.
ON THE MARINE FRONT...BUOY 89 HAD A PEAK GUST TO 58 KT AS OF
12Z...AND SEAS ARE ALREADY UP TO 22 TO 26 FT.
AND ON COASTAL WINDS...LINCOLN CITY HAD A GUST TO 61 MPH...AND THE
GRADIENT IS REALLY TIGHT...BUT THE WARM SECTOR IS STILL SOUTH...BUT
SHOULD BE HEADING NORTH THROUGH THE MORNING.
.SHORT TERM...POTENT STORM SYSTEM TO DEAL WITH IN THE NEXT 24 HOURS.
THE VERY STRONG SUBSIDENCE SEEN IN WATER VAPOR PICTURES NEAR 46N
130W SUPPORTS THE EXPLOSIVE CYCLOGENESIS DEPICTED IN THE MODELS
BETWEEN 06Z AND 12Z THIS MORNING. MODELS CONTINUE TO SHOW A VERY
STRONG WIND FIELD ALOFT. THE TRIPLE POINT OF THE FRONT IS DIFFICULT
TO DETERMINE DEFINITIVELY...MAKING THE FORECAST OF LAND WINDS AND
SNOW LEVELS N OF THE WARM FRONT ALL THE MORE DIFFICULT. ISENTROPIC
LIFT WITH THIS SYSTEM IS MODEST...MODELS INDICATE MOST OF THE LIFT
COMING WITH STRONG FRONTOGENESIS...WHICH MEANS THE SPREAD OF HEAVY
PRECIPITATION INLAND WILL BE RELATIVELY SLOW AND TIED TO THE SURFACE
COLD/OCCLUDED FRONT. BEST GUESS IS THAT THE TRIPLE POINT IS HEADED
INLAND ON THE NORTH OR CENTRAL OREGON COAST...AND INLAND INTO THE S
WILLAMETTE VALLEY. THIS WOULD PUT THE POTENTIAL FOR STRONGEST
SURFACE WINDS ON THE OREGON COAST...ALTHOUGH CONVECTIVE GUSTS
FURTHER N SHOULD STILL EXCEED HIGH WIND CRITERIA AS EVIDENCED BY
OBSERVED WINDS OVERNIGHT AT CLATSOP SPIT AND CAPE DISAPPOINTMENT.
GIVEN MODELS CONTINUOUSLY PUTTING PEAK GUSTS OVER THE WATER ON THE
ORDER OF 75 KT TODAY... WILL BUMP UP PEAK GUSTS SOME ESP ON THE
OREGON COAST. INLAND WINDS ALSO PROBLEMATIC AS THE UW MM5-NAM MODEL
CONTINUES TO SUGGEST WIND ADVISORY TYPE GUSTS IN THE VALLEY TODAY.
GIVEN THE LACK OF A STRONG N-S SURFACE PRES GRADIENT THOUGH...AM
RELUCTANT TO ISSUE ANY SORT OF INLAND ADVISORIES FOR WIND UNTIL WILL
SEE SOME EVIDENCE OF SUCH WINDS DEVELOPING IN SURFACE OBSERVATIONS.
AT THE END OF THE DAY...00Z TUE...WRF-GFS SUGGESTS TAIL END OF A
BENT BACK OCCLUSION BRINGING ANOTHER SHOT OF WINDS TO THE S WA AND N
OREGON COAST. AS THIS APPEARS TO BE A NEW DEVELOPMENT NOT SUPPORTED
BY OTHER MODELS...WILL NOT ACT ON THIS FEATURE BUT IT DOES BEAR
WATCHING TODAY.
SURFACE OBSERVATIONS SUGGEST SNOW LEVEL ON THE ORDER OF 1500-2000
FEET EARLY THIS MORNING. WITH LOW LEVEL OFFSHORE FLOW...SNOW LEVELS
LOOK UNLIKELY TO WARM MUCH UNTIL MAYBE THE END OF THE DAY WHEN WIND
FINALLY PICKS UP AN ONSHORE COMPONENT. WITH FAIRLY HEAVY
PRECIPITATION RATES EXPECTED WITH THE FRONT...POTENTIAL EXISTS FOR
THE N COAST RANGE AND WILLAPA HILLS TO SEE LOWERING SNOW LEVELS IN
THE HEAVY PRECIPITATION THIS AFTERNOON AND EVENING. AS SUCH...WILL
GO FOR A WINTER STORM WARNING IN THE COAST RANGE AND WILLAPA HILLS
TODAY INTO TONIGHT...MAINLY FOR AREAS ABOVE 2000 FT. THE S WA
CASCADES AND FOOTHILLS WILL BENEFIT FROM PROLONGED GOOD OROGRAPHICS
DUE TO THE STRONG SSW LOW LEVEL FLOW...SO WILL ALSO BUMP THOSE AREAS
UP TO A WINTER STORM WARNING FOR TODAY AND TONIGHT.
THE PRECIPITATION WILL TURN TO SHOWERS BEHIND THE FRONT TUE AS
COLDER AIR MOVES IN. NAM BUFR SOUNDINGS SUGGEST SNOW LEVELS BELOW
1000 FT...BUT GIVEN ONSHORE FLOW WITH 1000-500 MB THICKNESS OF 522
DM AND H8 TEMPS ON THE ORDER OF -6 C...WILL BOTTOM OUT SNOW LEVELS
AT 1000 FT IN THE SHOWERS. SHOWERS WEAKEN WITH WEAKENING ONSHORE
FLOW TUE NIGHT...THEN CHANCE FOR PRECIPITATION INCREASE AGAIN ON WED
IN THE NW PART OF THE AREA AS MOIST WARM AIR ADVECTION KICKS IN
AHEAD OF THE NEXT SYSTEM.
.LONG TERM...NO CHANGES...PREVIOUS DISCUSSION FOLLOWS.
IT CONTINUES TO LOOK LIKE COOL AND WET WEATHER WILL DOMINATE THE
EXTENDED FCST PERIOD. A STRONG UPPER LEVEL JET AND LONGWAVE
TROUGHING PATTERN WILL REMAIN OVER THE EASTERN PAC AT LEAST
THROUGH NEXT WEEKEND. MODEL AGREEMENT IS FAIRLY GOOD THAT WARM
FRONTAL RAIN ALONG WITH GUSTY COASTAL WINDS WILL SPREAD INTO THE
FCST AREA DURING THE SECOND HALF OF WED. AN APPROACHING SHORTWAVE
WILL BRING EVEN WETTER CONDITIONS ON THU. SNOW LEVELS WILL REMAIN
FAIRLY HIGH ON WED AND THU...WITH SIGNIFICANT SNOWFALL ACCUMULATIONS
CONFINED TO THE HIGHER ELEVATIONS OF THE CASCADES. HEADING INTO NEXT
WEEKEND...THE EXTENDED MODELS CONTINUE TO SUGGEST THAT THE UPPER
LEVEL TROUGHING WILL DIG FURTHER SOUTH...WITH THE BULK OF THE ENERGY
FOCUSED IN NORTHERN CALIFORNIA. THIS WOULD LEAVE US IN A SHOWERY
PATTERN WITH SNOW LEVELS DOWN INTO THE COAST RANGE AND CASCADE
FOOTHILLS. JFP
&&
.AVIATION...CIGS WILL GENERALLY BE MVFR ALONG THE COAST..THEN DROP
TO IFR THIS MORNING AT TIMES...EVEN LIFR IN HEAVY RAIN LATE THIS
MORNING THIS AFTERNOON. BIG ISSUE WILL BE THE VERY STRONG WINDS
EXPECTED IN THE MORNING ALONG THE NORTH COAST...LINGERING INTO THE
AFTERNOON SOUTH NEAR NEWPORT. SOUTH WIND GUSTS TO 50 KT AND HIGHER
ARE POSSIBLE.
INLAND WINDS WILL INCREASE AROUND 12Z ESPECIALLY ALOFT STRONG
WINDS IN THE LOWER LEVELS AFTER 12Z MON...GENERALLY BELOW 900
MB...WILL LIKELY RESULT IN LOW-LEVEL WIND SHEAR...MAINLY SPEED
SHEAR OF +/- 15 KT OR MORE..AT MOST OF THE TAF SITES...BUT THE
BEST SHOT AT THE KPDX/KTTD TAF SITES WHERE LESS MIXING MAY BE
OCCURRING. WE WILL TAKE A CLOSER LOOK AT THIS TO SEE IF IT IS
NEEDED...BUT FLIERS SHOULD AWARE THAT WHETHER THESE WINDS SURFACE
OR NOT...WINDS AT 1000-1500 FT WILL BE IN THE 40-50 KT RANGE.
EXPECT MOST OF THE INLAND PRECIP TO HOLD OFF UNTIL MID
MORNING...WITH VFR UNTIL THEN...THEN MVFR...WITH IFR IN MODERATE
TO HEAVY RAIN THIS EVENING. WE MAY SEE SOME SNOW MIXED IN DOWN TO
LOW LEVELS LATER THIS EVENING OR OVERNIGHT...BUT CONFIDENCE LOW
RIGHT NOW.
KPDX AND APPROACHES...EXPECT PRIMARILY VFR THROUGH AT LEAST 12Z
MON. LOW- LEVEL WIND INCREASES AFTER 12Z MON...FOR A THREAT OF
LOW-LEVEL WIND SHEAR (SPEED SHEAR) OF AT LEAST +/- 15 KT. EXPECT
CIGS TO REMAIN VFR UNTIL MIDDAY WHEN CIGS WILL LOWER AS THE FRONT
APPROACHES. IFR IS POSSIBLE IN MODERATE TO HEAVY RAIN THIS
EVENING. KMD
&&
.MARINE...SEAS ARE COMING UP VERY QUICKLY THIS MORNING WITH BUOY
29 NOW UP TO 22 FT...AND THE ASTORIA CANYON BUOY WHICH IS SLIGHTLY
FURTHER OFFSHORE AT 23 FT...AND OVERALL SWAN/ENP GUIDANCE IS NOT
TOO FAR OFF THE MARK. BUOY 5...ABOUT 300 NM OFFSHORE HIT ITS
LOWEST PRESSURE OF 974 MB AT 9Z...AND NOW IS ALREADY BACK UP TO
978 MB AS THE LOW HEADS NORTH INSIDE OF 130 W. WE HAVE HAD PEAK
WINDS SO FAR TO 51 KT IN THE OUTER WATERS...BUT AN IMPRESSIVE
GRADIENT IS DRAPED OVER THE WATERS WITH PRESSURES AT THE COAST
GENERALLY STILL AT 1000 MB OR HIGHER.
THE HRRR MODEL...AMONG OTHERS...ARE STILL SHOWING HURRICANE FORCE
GUSTS UP TO 75KT OVER THE COASTAL WATERS. IT IS ADVERTISING 64 KT
GUSTS AS OF NOW...AND WE HAVE HAD PEAK WINDS AT BUOY 29 (20 NM
OFFSHORE) OF 51 KT...54 KT AT BUOY 89 (70 NM OFFSHORE) SO IT MAY BE
RUNNING HIGH...POSSIBLY A TIMING ISSUE...OR THE BUOY IS STRUGGLING TO
REPORT HIGHER GUSTS. GIVEN THAT THIS CYCLOGENESIS BOMB...SEEN IN THE
BUOY 5 OBS DROPPING 25 MB IN 8 HOURS...EXPECT THAT WE WILL SEE VERY
HIGH END STORM FORCE WINDS AND SOME HURRICANE FORCE WINDS TO
MAINTAIN THE MESOSCALE MODEL ADVERTISED WIND GUSTS.
HAVE MAINTAINED THE GOING FORECAST FOR SEAS GETTING INTO THE UPPER
TO 20S TO LOW 30S AS THE SWAN ADVERTISES...AS SEAS ARE COMING UP
FAST. THE MAJORITY OF THE ENERGY WITH THESE WAVES WILL BE WITH THE
SHORTER PERIOD 12 SECOND WAVES. ALTHOUGH THE DIRECTION WILL BE
FROM THE SOUTHWEST WE ARE STILL AT THE LOW END FOR A HIGH SURF
WARNING. THE TIDAL ANOMALIES HAVE BEEN RUNNING 1 TO 2 FEET AND
EXPECT THIS TO REACH 3 FT TOMORROW MORNING. WITH THE HIGH TIDES
AROUND 10Z TO 12Z...THIS HAS PUT THE SOUTH WASHINGTON COAST INTO
COASTAL FLOOD ADVISORY CATEGORY FOR MINOR TIDAL OVERFLOW FOR A FEW
HOURS AROUND HIGH TIDE THIS MORNING...SET AROUND 430 AM AT TOKE
POINT. WIDESPREAD COASTAL FLOODING SHOULD NOT BE A CONCERN...AS THE
TIMING OF THE HIGHEST SWELL IS EXPECTED TO BE WHEN THE TIDE IS
FALLING AND DURING LOW TIDE. DURING THE SECOND HIGH TIDE SEAS SHOULD
NOT BE HIGH ENOUGH TO PRODUCE COASTAL FLOODING. SEAS WILL REMAIN
ABOVE 20 FEET THROUGH LATE MONDAY AFTERNOON...THEN FALL OFF
OVERNIGHT MONDAY.
AN DESPITE THE UW NAM ADVERTISING 50 KT WORKING ITS WAY BACK INTO
THE N OR/S WA COAST THIS AFTERNOON...IT WAS THE ONLY MODEL DOING
SO AND ONLY IN ITS CURRENT RUN. AT THIS TIME MOST MODELS KEEP THE
POISONOUS TAIL OF THE BENT BACK OCCLUSION HEADED TO OUR
NORTH...AND THUS WILL MAINTAIN THE CURRENT TIMING FOR OUR WARNINGS.
AFTER THE MON SYSTEM...IT LOOKS LIKE ANOTHER FAIRLY STRONG
DISTURBANCE MOVES THROUGH THE WATERS WED...AND A STRONGER LOW WED
NIGHT FOR SOLID GALES ON BOTH...POSSIBLY SOME LOW END STORM FORCE
GUSTS ON THE LATTER. THINGS LOOK TO CALM DOWN A BIT AFTER THIS.
KMD/SCHNEIDER
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 7 AM PDT
TUESDAY FOR NORTHERN OREGON CASCADES.
WINTER WEATHER ADVISORY FROM 1 AM TO 11 AM PDT TUESDAY FOR
CASCADES IN LANE COUNTY.
HIGH WIND WARNING UNTIL 5 PM PDT THIS AFTERNOON FOR CENTRAL
OREGON COAST-NORTH OREGON COAST.
HIGH SURF WARNING UNTIL 11 PM PDT THIS EVENING FOR CENTRAL
OREGON COAST-NORTH OREGON COAST.
WINTER STORM WARNING FROM 8 AM THIS MORNING TO 3 AM PDT TUE
FOR COAST RANGE OF NORTHWEST OREGON.
WIND ADVISORY FOR THE NORTH WILLAMETTE VALLEY UNTIL 1 PM.
WIND ADVISORY FOR THE CENTRAL AND SOUTHERN WILLAMETTE VALLEY
UNTIL 5 PM.
WA...WINTER STORM WARNING FROM 8 AM THIS MORNING TO 5 AM PDT TUE
FOR SOUTH WASHINGTON CASCADE FOOTHILLS-SOUTH WASHINGTON
CASCADES.
HIGH WIND WARNING UNTIL 5 PM PDT THIS AFTERNOON FOR SOUTH
WASHINGTON COAST.
HIGH SURF WARNING UNTIL 11 PM PDT THIS EVENING FOR SOUTH
WASHINGTON COAST.
WINTER STORM WARNING FROM 8 AM THIS MORNING TO 3 AM PDT TUE
FOR WILLAPA HILLS.
COASTAL FLOOD ADVISORY UNTIL 6 AM PDT EARLY THIS MORNING FOR
SOUTH WASHINGTON COAST.
WIND ADVISORY FOR CLARK COUNTY IN SW WASHINGTON UNTIL 1 PM.
PZ...HURRICANE FORCE WIND WARNING UNTIL 1 PM PDT THIS AFTERNOON FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
OUT 10 NM-WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
FROM 10 TO 60 NM.
HURRICANE FORCE WIND WARNING UNTIL 6 PM PDT THIS EVENING FOR
COASTAL WATERS FROM CASCADE HEAD TO FLORENCE OR OUT 10 NM-
WATERS FROM CASCADE HEAD TO FLORENCE OR FROM 10 TO 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
11 AM PDT TUESDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS PORTLAND OR
333 AM PDT SUN MAR 12 2012
.SYNOPSIS...A STRONG PACIFIC FRONT WILL BRING STRONG WINDS...HEAVY
RAIN AND MOUNTAIN SNOW TODAY. A SERIES OF SYSTEMS WILL MAINTAIN
DAMP AND COOL WEATHER THROUGH NEXT WEEK.
&&
.SHORT TERM...POTENT STORM SYSTEM TO DEAL WITH IN THE NEXT 24 HOURS.
THE VERY STRONG SUBSIDENCE SEEN IN WATER VAPOR PICTURES NEAR 46N
130W SUPPORTS THE EXPLOSIVE CYCLOGENESIS DEPICTED IN THE MODELS
BETWEEN 06Z AND 12Z THIS MORNING. MODELS CONTINUE TO SHOW A VERY
STRONG WIND FIELD ALOFT. THE TRIPLE POINT OF THE FRONT IS DIFFICULT
TO DETERMINE DEFINITIVELY...MAKING THE FORECAST OF LAND WINDS AND
SNOW LEVELS N OF THE WARM FRONT ALL THE MORE DIFFICULT. ISENTROPIC
LIFT WITH THIS SYSTEM IS MODEST...MODELS INDICATE MOST OF THE LIFT
COMING WITH STRONG FRONTOGENESIS...WHICH MEANS THE SPREAD OF HEAVY
PRECIPITATION INLAND WILL BE RELATIVELY SLOW AND TIED TO THE SURFACE
COLD/OCCLUDED FRONT. BEST GUESS IS THAT THE TRIPLE POINT IS HEADED
INLAND ON THE NORTH OR CENTRAL OREGON COAST...AND INLAND INTO THE S
WILLAMETTE VALLEY. THIS WOULD PUT THE POTENTIAL FOR STRONGEST
SURFACE WINDS ON THE OREGON COAST...ALTHOUGH CONVECTIVE GUSTS
FURTHER N SHOULD STILL EXCEED HIGH WIND CRITERIA AS EVIDENCED BY
OBSERVED WINDS OVERNIGHT AT CLATSOP SPIT AND CAPE DISAPPOINTMENT.
GIVEN MODELS CONTINUOUSLY PUTTING PEAK GUSTS OVER THE WATER ON THE
ORDER OF 75 KT TODAY... WILL BUMP UP PEAK GUSTS SOME ESP ON THE
OREGON COAST. INLAND WINDS ALSO PROBLEMATIC AS THE UW MM5-NAM MODEL
CONTINUES TO SUGGEST WIND ADVISORY TYPE GUSTS IN THE VALLEY TODAY.
GIVEN THE LACK OF A STRONG N-S SURFACE PRES GRADIENT THOUGH...AM
RELUCTANT TO ISSUE ANY SORT OF INLAND ADVISORIES FOR WIND UNTIL WILL
SEE SOME EVIDENCE OF SUCH WINDS DEVELOPING IN SURFACE OBSERVATIONS.
AT THE END OF THE DAY...00Z TUE...WRF-GFS SUGGESTS TAIL END OF A
BENT BACK OCCLUSION BRINGING ANOTHER SHOT OF WINDS TO THE S WA AND N
OREGON COAST. AS THIS APPEARS TO BE A NEW DEVELOPMENT NOT SUPPORTED
BY OTHER MODELS...WILL NOT ACT ON THIS FEATURE BUT IT DOES BEAR
WATCHING TODAY.
SURFACE OBSERVATIONS SUGGEST SNOW LEVEL ON THE ORDER OF 1500-2000
FEET EARLY THIS MORNING. WITH LOW LEVEL OFFSHORE FLOW...SNOW LEVELS
LOOK UNLIKELY TO WARM MUCH UNTIL MAYBE THE END OF THE DAY WHEN WIND
FINALLY PICKS UP AN ONSHORE COMPONENT. WITH FAIRLY HEAVY
PRECIPITATION RATES EXPECTED WITH THE FRONT...POTENTIAL EXISTS FOR
THE N COAST RANGE AND WILLAPA HILLS TO SEE LOWERING SNOW LEVELS IN
THE HEAVY PRECIPITATION THIS AFTERNOON AND EVENING. AS SUCH...WILL
GO FOR A WINTER STORM WARNING IN THE COAST RANGE AND WILLAPA HILLS
TODAY INTO TONIGHT...MAINLY FOR AREAS ABOVE 2000 FT. THE S WA
CASCADES AND FOOTHILLS WILL BENEFIT FROM PROLONGED GOOD OROGRAPHICS
DUE TO THE STRONG SSW LOW LEVEL FLOW...SO WILL ALSO BUMP THOSE AREAS
UP TO A WINTER STORM WARNING FOR TODAY AND TONIGHT.
THE PRECIPITATION WILL TURN TO SHOWERS BEHIND THE FRONT TUE AS
COLDER AIR MOVES IN. NAM BUFR SOUNDINGS SUGGEST SNOW LEVELS BELOW
1000 FT...BUT GIVEN ONSHORE FLOW WITH 1000-500 MB THICKNESS OF 522
DM AND H8 TEMPS ON THE ORDER OF -6 C...WILL BOTTOM OUT SNOW LEVELS
AT 1000 FT IN THE SHOWERS. SHOWERS WEAKEN WITH WEAKENING ONSHORE
FLOW TUE NIGHT...THEN CHANCE FOR PRECIPITATION INCREASE AGAIN ON WED
IN THE NW PART OF THE AREA AS MOIST WARM AIR ADVECTION KICKS IN
AHEAD OF THE NEXT SYSTEM.
.LONG TERM...NO CHANGES...PREVIOUS DISCUSSION FOLLOWS.
IT CONTINUES TO LOOK LIKE COOL AND WET WEATHER WILL DOMINATE THE
EXTENDED FCST PERIOD. A STRONG UPPER LEVEL JET AND LONGWAVE
TROUGHING PATTERN WILL REMAIN OVER THE EASTERN PAC AT LEAST
THROUGH NEXT WEEKEND. MODEL AGREEMENT IS FAIRLY GOOD THAT WARM
FRONTAL RAIN ALONG WITH GUSTY COASTAL WINDS WILL SPREAD INTO THE
FCST AREA DURING THE SECOND HALF OF WED. AN APPROACHING SHORTWAVE
WILL BRING EVEN WETTER CONDITIONS ON THU. SNOW LEVELS WILL REMAIN
FAIRLY HIGH ON WED AND THU...WITH SIGNIFICANT SNOWFALL ACCUMULATIONS
CONFINED TO THE HIGHER ELEVATIONS OF THE CASCADES. HEADING INTO NEXT
WEEKEND...THE EXTENDED MODELS CONTINUE TO SUGGEST THAT THE UPPER
LEVEL TROUGHING WILL DIG FURTHER SOUTH...WITH THE BULK OF THE ENERGY
FOCUSED IN NORTHERN CALIFORNIA. THIS WOULD LEAVE US IN A SHOWERY
PATTERN WITH SNOW LEVELS DOWN INTO THE COAST RANGE AND CASCADE
FOOTHILLS. JFP
&&
.AVIATION...CIGS WILL GENERALLY BE MVFR ALONG THE COAST..THEN DROP
TO IFR THIS MORNING AT TIMES...EVEN LIFR IN HEAVY RAIN LATE THIS
MORNING THIS AFTERNOON. BIG ISSUE WILL BE THE VERY STRONG WINDS
EXPECTED IN THE MORNING ALONG THE NORTH COAST...LINGERING INTO THE
AFTERNOON SOUTH NEAR NEWPORT. SOUTH WIND GUSTS TO 50 KT AND HIGHER
ARE POSSIBLE.
INLAND WINDS WILL INCREASE AROUND 12Z ESPECIALLY ALOFT STRONG
WINDS IN THE LOWER LEVELS AFTER 12Z MON...GENERALLY BELOW 900
MB...WILL LIKELY RESULT IN LOW-LEVEL WIND SHEAR...MAINLY SPEED
SHEAR OF +/- 15 KT OR MORE..AT MOST OF THE TAF SITES...BUT THE
BEST SHOT AT THE KPDX/KTTD TAF SITES WHERE LESS MIXING MAY BE
OCCURRING. WE WILL TAKE A CLOSER LOOK AT THIS TO SEE IF IT IS
NEEDED...BUT FLIERS SHOULD AWARE THAT WHETHER THESE WINDS SURFACE
OR NOT...WINDS AT 1000-1500 FT WILL BE IN THE 40-50 KT RANGE.
EXPECT MOST OF THE INLAND PRECIP TO HOLD OFF UNTIL MID
MORNING...WITH VFR UNTIL THEN...THEN MVFR...WITH IFR IN MODERATE
TO HEAVY RAIN THIS EVENING. WE MAY SEE SOME SNOW MIXED IN DOWN TO
LOW LEVELS LATER THIS EVENING OR OVERNIGHT...BUT CONFIDENCE LOW
RIGHT NOW.
KPDX AND APPROACHES...EXPECT PRIMARILY VFR THROUGH AT LEAST 12Z
MON. LOW- LEVEL WIND INCREASES AFTER 12Z MON...FOR A THREAT OF
LOW-LEVEL WIND SHEAR (SPEED SHEAR) OF AT LEAST +/- 15 KT. EXPECT
CIGS TO REMAIN VFR UNTIL MIDDAY WHEN CIGS WILL LOWER AS THE FRONT
APPROACHES. IFR IS POSSIBLE IN MODERATE TO HEAVY RAIN THIS
EVENING. KMD
&&
.MARINE...SEAS ARE COMING UP VERY QUICKLY THIS MORNING WITH BUOY
29 NOW UP TO 22 FT...AND THE ASTORIA CANYON BUOY WHICH IS SLIGHTLY
FURTHER OFFSHORE AT 23 FT...AND OVERALL SWAN/ENP GUIDANCE IS NOT
TOO FAR OFF THE MARK. BUOY 5...ABOUT 300 NM OFFSHORE HIT ITS
LOWEST PRESSURE OF 974 MB AT 9Z...AND NOW IS ALREADY BACK UP TO
978 MB AS THE LOW HEADS NORTH INSIDE OF 130 W. WE HAVE HAD PEAK
WINDS SO FAR TO 51 KT IN THE OUTER WATERS...BUT AN IMPRESSIVE
GRADIENT IS DRAPED OVER THE WATERS WITH PRESSURES AT THE COAST
GENERALLY STILL AT 1000 MB OR HIGHER.
THE HRRR MODEL...AMONG OTHERS...ARE STILL SHOWING HURRICANE FORCE
GUSTS UP TO 75KT OVER THE COASTAL WATERS. IT IS ADVERTISING 64 KT
GUSTS AS OF NOW...AND WE HAVE HAD PEAK WINDS AT BUOY 29 (20 NM
OFFSHORE) OF 51 KT...54 KT AT BUOY 89 (70 NM OFFSHORE) SO IT MAY BE
RUNNING HIGH...POSSIBLY A TIMING ISSUE...OR THE BUOY IS STRUGGLING TO
REPORT HIGHER GUSTS. GIVEN THAT THIS CYCLOGENESIS BOMB...SEEN IN THE
BUOY 5 OBS DROPPING 25 MB IN 8 HOURS...EXPECT THAT WE WILL SEE VERY
HIGH END STORM FORCE WINDS AND SOME HURRICANE FORCE WINDS TO
MAINTAIN THE MESOSCALE MODEL ADVERTISED WIND GUSTS.
HAVE MAINTAINED THE GOING FORECAST FOR SEAS GETTING INTO THE UPPER
TO 20S TO LOW 30S AS THE SWAN ADVERTISES...AS SEAS ARE COMING UP
FAST. THE MAJORITY OF THE ENERGY WITH THESE WAVES WILL BE WITH THE
SHORTER PERIOD 12 SECOND WAVES. ALTHOUGH THE DIRECTION WILL BE
FROM THE SOUTHWEST WE ARE STILL AT THE LOW END FOR A HIGH SURF
WARNING. THE TIDAL ANOMALIES HAVE BEEN RUNNING 1 TO 2 FEET AND
EXPECT THIS TO REACH 3 FT TOMORROW MORNING. WITH THE HIGH TIDES
AROUND 10Z TO 12Z...THIS HAS PUT THE SOUTH WASHINGTON COAST INTO
COASTAL FLOOD ADVISORY CATEGORY FOR MINOR TIDAL OVERFLOW FOR A FEW
HOURS AROUND HIGH TIDE THIS MORNING...SET AROUND 430 AM AT TOKE
POINT. WIDESPREAD COASTAL FLOODING SHOULD NOT BE A CONCERN...AS THE
TIMING OF THE HIGHEST SWELL IS EXPECTED TO BE WHEN THE TIDE IS
FALLING AND DURING LOW TIDE. DURING THE SECOND HIGH TIDE SEAS SHOULD
NOT BE HIGH ENOUGH TO PRODUCE COASTAL FLOODING. SEAS WILL REMAIN
ABOVE 20 FEET THROUGH LATE MONDAY AFTERNOON...THEN FALL OFF
OVERNIGHT MONDAY.
AN DESPITE THE UW NAM ADVERTISING 50 KT WORKING ITS WAY BACK INTO
THE N OR/S WA COAST THIS AFTERNOON...IT WAS THE ONLY MODEL DOING
SO AND ONLY IN ITS CURRENT RUN. AT THIS TIME MOST MODELS KEEP THE
POISONOUS TAIL OF THE BENT BACK OCCLUSION HEADED TO OUR
NORTH...AND THUS WILL MAINTAIN THE CURRENT TIMING FOR OUR WARNINGS.
AFTER THE MON SYSTEM...IT LOOKS LIKE ANOTHER FAIRLY STRONG
DISTURBANCE MOVES THROUGH THE WATERS WED...AND A STRONGER LOW WED
NIGHT FOR SOLID GALES ON BOTH...POSSIBLY SOME LOW END STORM FORCE
GUSTS ON THE LATTER. THINGS LOOK TO CALM DOWN A BIT AFTER THIS.
KMD/SCHNEIDER
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 7 AM PDT
TUESDAY FOR NORTHERN OREGON CASCADES.
WINTER WEATHER ADVISORY FROM 1 AM TO 11 AM PDT TUESDAY FOR
CASCADES IN LANE COUNTY.
HIGH WIND WARNING UNTIL 5 PM PDT THIS AFTERNOON FOR CENTRAL
OREGON COAST-NORTH OREGON COAST.
HIGH SURF WARNING UNTIL 11 PM PDT THIS EVENING FOR CENTRAL
OREGON COAST-NORTH OREGON COAST.
WINTER STORM WARNING FROM 8 AM THIS MORNING TO 3 AM PDT TUE
FOR COAST RANGE OF NORTHWEST OREGON.
WA...WINTER STORM WARNING FROM 8 AM THIS MORNING TO 5 AM PDT TUE
FOR SOUTH WASHINGTON CASCADE FOOTHILLS-SOUTH WASHINGTON
CASCADES.
HIGH WIND WARNING UNTIL 5 PM PDT THIS AFTERNOON FOR SOUTH
WASHINGTON COAST.
HIGH SURF WARNING UNTIL 11 PM PDT THIS EVENING FOR SOUTH
WASHINGTON COAST.
WINTER STORM WARNING FROM 8 AM THIS MORNING TO 3 AM PDT TUE
FOR WILLAPA HILLS.
COASTAL FLOOD ADVISORY UNTIL 6 AM PDT EARLY THIS MORNING FOR
SOUTH WASHINGTON COAST.
PZ...HURRICANE FORCE WIND WARNING UNTIL 1 PM PDT THIS AFTERNOON FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
OUT 10 NM-WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
FROM 10 TO 60 NM.
HURRICANE FORCE WIND WARNING UNTIL 6 PM PDT THIS EVENING FOR
COASTAL WATERS FROM CASCADE HEAD TO FLORENCE OR OUT 10 NM-
WATERS FROM CASCADE HEAD TO FLORENCE OR FROM 10 TO 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
11 AM PDT TUESDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS PORTLAND OR
913 PM PDT SUN MAR 11 2012
.SYNOPSIS...A WARM FRONT WILL CONTINUE RAIN ALONG THE COAST
TONIGHT..WITH DECREASING SHOWERS ELSEWHERE. A STRONG PACIFIC FRONT
WILL BRING STRONG WINDS...HEAVY RAIN AND MOUNTAIN SNOW MONDAY. A
SERIES OF SYSTEMS WILL MAINTAIN DAMP AND COOL WEATHER THROUGH NEXT
WEEK.
&&
.UPDATE...WE HAVE UPGRADED THE STORM WARNING FOR THE COASTAL WATERS
TO A HURRIANCE FORCE WIND WARNING. MULTIPLE MESOSCALE
MODELS...INCLUDING THE UW NAM...RUC HRRR...AND THE PORTLAND WFO
LOCAL WRF BRING GUSTS TO 70KT...AND PRESSURE FALLS WELL OFFSHORE
HAVE BEEN 5 MB IN 1 HR/ 13 MB IN 3 HR.
.SHORT TERM...SHOWERS ARE WINDING DOWN THIS EVENING...BUT THERE WILL
NOT BE MUCH BREAK IN THE WEATHER...AT LEAST FOR THE COAST...AS THE
WARM FRONT ASSOCIATED WITH THE NEXT LOW IS QUICKLY APPROACHING FROM
THE WEST. SATELLITE IMAGERY SHOWS A SURFACE LOW DEVELOPING AROUND 37N
137W EARLY THIS EVENING. THIS LOW WILL DEEPEN AS IT NEARS THE COAST
AND SOUTH WINDS WILL INCREASE OFFSHORE AND ALONG THE COAST THROUGH
THE NIGHT. THIS STORM WILL BRING STRONG WINDS...HEAVY RAIN AND
MOUNTAIN SNOW MONDAY.
RAIN ASSOCIATED AHEAD OF THE WARM FRONT IS STARTING TO SHOW ON RADAR
AROUND 60 MILES OFFSHORE. LIGHT RAIN WILL CONTINUE ALONG THE COAST
THROUGH THE NIGHT BUT THE REST OF THE FORECAST AREA WILL HAVE A BRIEF
BREAK IN PRECIPITATION. MODELS CONTINUE TO SHOW THE OCCLUDED OR COLD
FRONT PUSHING STEADILY INLAND MONDAY. THE PRECIPITATION WILL BE HEAVY
AT TIMES AND EXPECT RAINFALL TOTALS TO APPROACH 2 INCHES ALONG THE
COAST AND 3 INCHES FOR THE COAST RANGE.
THE CASCADES WILL SEE PLENTY OF SNOW AND HAVE KEPT FORECAST SNOW
AMOUNTS NEAR HIGH END ADVISORY LEVELS. THE HIGHEST SNOW TOTALS AND
LONGEST DURATION OF SNOWFALL IS EXPECTED ACROSS THE SOUTH WASHINGTON
CASCADES. PRECIPITATION IN THE COAST RANGE AND CASCADE FOOTHILLS WILL
LIKELY START OUT AS SNOW MONDAY MORNING WITH A FEW INCHES POSSIBLE.
HOWEVER...WARM AIR WILL MOVE IN DURING THE DAY CAUSING A CHANGE OVER
TO RAIN.
WINDS OFFSHORE ARE ALREADY PICKING UP THIS EVENING WITH BUOY
OBSERVATIONS REPORTING GUSTS TO 41 KT. THE WIND FIELDS ASSOCIATED
WITH MONDAYS CYCLOGENIC BOMB ARE IMPRESSIVE. WHILE THE MODELS APPEAR
SET ON RUNNING THE DEEPENING LOW EARLY MON UP AROUND 130W OFF OF
VANCOUVER ISLAND...THE STRONG WINDS SURROUNDING THE STORM EXTEND
OUTWARDS CONSIDERABLY. GFS ENSEMBLES
CONTINUE TO SHOW SSW H8 WINDS OF 60 TO 70 KT OVER NW OREGON AND SW
WA MON MORNING...WHICH IS FIVE STANDARD DEVIATIONS ABOVE NORMAL. THE
UW MM5-NAM THROWS IN SOME 50 KT GUSTS IN THE WILLAMETTE VALLEY
MONDAY...BUT WOULD PREFER TO SEE A STRONGER N-S SURFACE PRESSURE
GRADIENT BEFORE PUTTING TOO MUCH WIND INLAND.
THE PRECIPITATION WILL TURN TO SHOWERS BEHIND THE FRONT MONDAY NIGHT
AND TUESDAY AS COLDER AIR MOVES IN. SNOW LEVELS WILL DROP DOWN TO
AROUND 1000 FEET TUESDAY MORNING...BUT SNOW ACCUMULATIONS AT THE
LOWER ELEVATIONS SHOULD BE MINIMAL.
.LONG TERM...MADE NO CHANGES...PREVIOUS DISCUSSION FOLLOWS...IT
CONTINUES TO LOOK LIKE COOL AND WET WEATHER WILL DOMINATE THE
EXTENDED FCST PERIOD. A STRONG UPPER LEVEL JET AND LONGWAVE TROUGHING
PATTERN WILL REMAIN OVER THE EASTERN PAC AT LEAST
THROUGH NEXT WEEKEND. MODEL AGREEMENT IS FAIRLY GOOD THAT WARM
FRONTAL RAIN ALONG WITH GUSTY COASTAL WINDS WILL SPREAD INTO THE
FCST AREA DURING THE SECOND HALF OF WED. AN APPROACHING SHORTWAVE
WILL BRING EVEN WETTER CONDITIONS ON THU. SNOW LEVELS WILL REMAIN
FAIRLY HIGH ON WED AND THU...WITH SIGNIFICANT SNOWFALL ACCUMULATIONS
CONFINED TO THE HIGHER ELEVATIONS OF THE CASCADES. HEADING INTO NEXT
WEEKEND...THE EXTENDED MODELS CONTINUE TO SUGGEST THAT THE UPPER
LEVEL TROUGHING WILL DIG FURTHER SOUTH...WITH THE BULK OF THE ENERGY
FOCUSED IN NORTHERN CALIFORNIA. THIS WOULD LEAVE US IN A SHOWERY
PATTERN WITH SNOW LEVELS DOWN INTO THE COAST RANGE AND CASCADE
FOOTHILLS. JFP
&&
.AVIATION...MVFR CONDITIONS WILL CONTINUE THIS EVENING BUT CIGS AND
VISIBILITY WILL BEGIN TO LOWER ON THE COAST AFTER MIDNIGHT AS A
WARM FRONT APPROACHES. CIGS WILL LOWER TO FR ALONG THE COAST
AROUND 12Z AS THE WARM FRONT PASSES WITH STRONG SOUTH WINDS. WINDS
WILL REMAIN STRONG IN THE WARM SECTOR UNTIL THE COLD FRONT PASSES.
EXPECT THE COLD FRONT TO REACH ASTORIA AROUND 19Z AND TO NEWPORT
AROUND 12Z. INLAND WINDS WILL INCREASE AROUND 12Z ESPECIALLY ALOFT
STRONG WINDS IN THE LOWER LEVELS AFTER 12Z MON...GENERALLY BELOW
900 MB...WILL LIKELY RESULT IN LOW-LEVEL WIND SHEAR...MAINLY SPEED
SHEAR OF +/- 15 KT OR MORE..AT MOST OF THE TAF SITES.
KPDX AND APPROACHES...EXPECT PRIMARILY VFR THROUGH AT LEAST 12Z
MON. LOW- LEVEL WIND INCREASES AFTER 12Z MON...FOR A THREAT OF
LOW-LEVEL WIND SHEAR (SPEED SHEAR) OF AT LEAST +/- 15 KT. EXPECT
CIGS TO REMAIN VFR UNTIL AFTERNOON WHEN CIGS WILL LOWER AS THE
FRONT APPROACHES.
&&
.MARINE...WINDS THIS EVENING HAVE BEEN VERY GUSTY WITH SHOWERS AND
ARE A BIT STRONGER THAN PREVIOUS FORECAST. THE NEW MODELS REMAIN
CONSTANT IN SHOWING SOLID STORM FORCE WINDS WITH THE DEVELOPING
LOW AND FRONT EARLY MONDAY MORNING. THE HRRR MODEL SHOWS HURRICANE
FORCE GUSTS UP TO 75KT OVER THE COASTAL WATERS...BUT SINCE THIS
GUIDANCE IS RELATIVELY NEW I HAVE CHOSEN TO STICK WITH A HIGH END
STORM WARNING. WE WILL NEED TO WATCH CLOSELY HOW THE LOW DEVELOPS.
THESE BOMB SYSTEMS ARE CAPABLE OF BEING DEEPER THAN THE MODELS
FORECAST. MODELS..SHOW STORM FORCE WIND HANGING ON LONGER OVER THE
FAR SOUTHERN WATERS MON AFTERNOON. HAD SOME CONCERNS THAT WE COULD
GET SOME ADDITIONAL STRONG WIND ON THE BACK SIDE OF THE LOW OVER THE
WASHINGTON WATERS...BUT AT THIS TIME MOST MODELS KEEP THE POISONOUS
TAIL OF THE BENT BACK OCCLUSION HEADED TO OUR NORTH.
AFTER THE MON SYSTEM...IT LOOKS LIKE ANOTHER FAIRLY STRONG
DISTURBANCE MOVES THROUGH THE WATERS WED. NAM AND GFS HAVE BACKED
OFF AND SLOWED IT DOWN...MORE INTO WED AFTERNOON. THE ECMWF STILL
BRINGS SOLID GALES TO THE WATERS LATE TUE NIGHT THROUGH WED
MORNING.
SEAS ALREADY IN THE 15 TO 16 FT RANGE WILL CONTINUE TO BUILD
RAPIDLY OVERNIGHT. WITH 12 HOURS OF STORM TO NEAR HURRICANE FORCE
WINDS I AM ADJUSTING THE SEA HEIGHTS UP IN THE FORECAST. THIS WILL
BE MORE IN LINE WITH OUR SWAN MODEL FORECAST WHICH IS BETTER WITH
THESE SYSTEMS THAT DEVELOP RAPIDLY NEAR THE COAST THAN THE
WAVEWATCH III MODEL. EXPECT TO SEE 28 TO 32 FOOT SEAS IN THE WATERS
TOMORROW...IN THE NORTH DURING THE MORNING AND IN THE SOUTH DURING
THE AFTERNOON. THE MAJORITY OF THE ENERGY WILL BE WITH THE SHORTER
PERIOD 12 SECOND WAVES. ALTHOUGH THE DIRECTION WILL BE FROM THE
SOUTHWEST WE ARE STILL AT THE LOW END FOR A HIGH SURF WARNING. THE
TIDAL ANOMALIES HAVE BEEN RUNNING 1 TO 2 FEET AND EXPECT THIS TO
REACH 3 FT TOMORROW MORNING. WITH THE HIGH TIDES AROUND 10Z TO 12Z
WE COULD HAVE COASTAL FLOODING IF THE SEAS WERE HIGH ENOUGH.
HOWEVER THE TIMING OF THE HIGHEST SWELL IS EXPECTED TO BE WHEN THE
TIDE IS FALLING AND DURING LOW TIDE. DURING THE SECOND HIGH TIDE
SHOULD NOT BE HIGH ENOUGH TO PRODUCE COASTAL FLOODING. SO FOR NOW
WE WILL NOT ISSUED A COASTAL FLOOD WARNING. SEAS WILL REMAIN ABOVE
20 FEET THROUGH LATE MONDAY AFTERNOON...THEN FALL OFF OVERNIGHT
MONDAY.
SCHNEIDER
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING FROM 2 AM TO 5 PM PDT MONDAY FOR CENTRAL
OREGON COAST-NORTH OREGON COAST.
HIGH SURF WARNING FROM 5 AM TO 11 PM PDT MONDAY FOR CENTRAL
OREGON COAST-NORTH OREGON COAST.
WINTER WEATHER ADVISORY FROM 3 PM MONDAY TO 7 AM PDT TUESDAY
FOR NORTHERN OREGON CASCADES.
WINTER WEATHER ADVISORY FROM 1 AM TO 11 AM PDT TUESDAY FOR
CASCADES IN LANE COUNTY.
WA...HIGH WIND WARNING FROM 2 AM TO 5 PM PDT MONDAY FOR SOUTH
WASHINGTON COAST.
HIGH SURF WARNING FROM 5 AM TO 11 PM PDT MONDAY FOR SOUTH
WASHINGTON COAST.
WINTER WEATHER ADVISORY FROM 7 AM MONDAY TO 5 AM PDT TUESDAY
FOR SOUTH WASHINGTON CASCADES.
PZ...HURRICANE FORCE WIND WARNING UNTIL 1 PM PDT MONDAY FOR COASTAL
WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60 NM.
HURRICANE FORCE WIND WARNING UNTIL 6 PM PDT MONDAY FOR COASTAL
WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 6 PM
PDT MONDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1121 PM EDT TUE MAR 13 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL CROSS THE OHIO VALLEY AND NORTHEAST UNITED
STATES TONIGHT. HIGH PRESSURE WILL REMAIN OVER THE MID ATLANTIC
AND SOUTHEAST STATES THROUGH THURSDAY. ANOTHER WEAK COLD FRONT
WILL APPROACH THE REGION ON FRIDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 1113 PM EDT TUESDAY...
WITH CONVECTION ALL BUT FADED ACROSS THE NW AND INSTABILITY
DIMINISHING...SENDING A QUICK UPDATE TO REMOVE MOST POPS
OVERNIGHT. HOWEVER MAY LEAVE IN AN ISOLATED MENTION FAR SW FOR A
COUPLE MORE HOURS WHERE A FEW NEW SHRA HAVE POPPED UP. OTRW
REDUCED CLOUD COVER OUTSIDE OF LATE NIGHT FOG WITH TREND TOWARD
MOSTLY CLEAR ALL AREAS AFTER MIDNIGHT.
AS OF 840 PM EDT TUESDAY...
ISOLATED CONVECTION CONTINUES JUST NW OF THE CWA THIS EVENING
AHEAD OF THE SFC COLD FRONT LAGGING BACK NEAR THE OHIO RIVER. WITH
A RIBBON OF RESIDUAL CAPE STILL OVER THE NW PER SPC MESO
ANALYSIS...MAY SEE SOME OF THIS COVERAGE MAKE A RUN AT THE FAR NW
ZONES BEFORE FADING IN THE NEXT HOUR OR TWO...AS LOW LEVELS REMAIN
QUITE DRY PER EVENING RAOBS/DEWPOINTS. LATEST HRRR AND LOCAL WRF
ALSO DISSIPATE ANY SHRA AFTER 10 PM SO ONLY PLANNING TO CARRY AN
ISOLATED MENTION AT BEST NW PENDING RELEASE COVERAGE. OTRW SHOULD
SEE ANY REMAINING CU FADE WITH LOSS OF HEATING ALLOWING FOR MAINLY
CLEAR SKIES AS THE SFC FRONT HANGS UP JUST TO THE NORTH BY
MORNING. WITH THE FLOW BECOMING LIGHT UNDER WEAK HIGH PRESSURE THE
OTHER CONCERN IS WITH FOG COVERAGE LATE ESPCLY SOUTH WHERE
MOISTURE IS A BIT HIGHER. LATEST RUC SOUNDINGS AND FOG STAB VALUES
DO SUPPORT AT LEAST PATCHY FOG IN THE VALLEYS BUT MORESO IN NW NC
WHERE BEEFED UP COVERAGE TO AREAS OF FOG LATE. MADE SMALL ADJUSTS
TO TEMPS TO RAISE VALUES ON THE RIDGES WITH STILL SOME 40S
POSSIBLE IN THE DEEPER VALLEYS.
PREVIOUS DISCUSSION AS OF 250 PM EDT TUESDAY...
WEAK SHORT WAVE ENERGY WILL BE MOVING WELL EAST OF THE FORECAST AREA
OVERNIGHT. WINDS FROM THE SURFACE THROUGH MID LEVEL WILL BECOME
NORTHWEST BY WEDNESDAY MORNING WHICH WILL SUPPRESS ANY DEVELOPMENT
OF PRECIPITATION EAST OF THE BLUE RIDGE ON WEDNESDAY.
MODELS HAVE THE TAIL END OF THE WEAK COLD FRONT CROSSING THE
NORTHEAST UNITED STATES JUST REACHING THE FAR NORTHERN COUNTY
WARNING AREA THIS EVENING. DEW POINTS MAY DROP BACK INTO THE 40S
NORTH OF THE FRONT OVERNIGHT...BUT OVERALL NO REAL CHANGE IN AIR
MASS TONIGHT OR WEDNESDAY. WITH SURFACE DEW POINTS STAYING THE
50S...HAVE ADDED FOG IN THE WESTERN VALLEYS TONIGHT.
STAYED CLOSE TO A BLEND OF BIAS CORRECTED MAV AND MET GUIDANCE FOR
LOWS TONIGHT AND HIGHS ON WEDNESDAY.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 300 PM EST TUESDAY...
WILL BE LOOKING AT A DIFFUSE WEATHER PATTERN THROUGH THE LATER HALF
OF THE WORKWEEK HEADING INTO THE WEEKEND. HIGH PRESSURE WILL SIT OFF
THE EAST COAST WEDNESDAY NIGHT AND THURSDAY...MAKING FOR SOUTHERLY
TO SOUTHWESTERLY WIND FLOW ACROSS OUR AREA. THIS FLOW WILL ALLOW THE
UNSEASONABLY WARM TEMPERATURES TO CONTINUE FOR THE EAST...AND WE CAN
EXPECT TEMPERATURES IN THE MID 40S TO LOWER 50S FOR WEDNESDAY NIGHT
LOWS. SPOTTY SHOWER ACTIVITY WILL MAKE ITS WAY INTO THE MOUNTAINS
THURSDAY MORNING...WITH THE POSSIBILITY OF A FEW SHOWERS DEVELOPING
INTO THUNDERSTORMS DURING THE MID AFTERNOON...AS A WEAK LOW PRESSURE
SYSTEM PASSES ALONG THE GREAT LAKES. CANNOT RULE OUT THE CHANCE OF A
STRONG THUNDERSTORM OR TWO DEVELOPING DURING THE AFTERNOON...BUT DO
NOT ANTICIPATE ANY ORGANIZED STRONG THUNDERSTORM ACTIVITY. THURSDAY
AFTERNOON TEMPERATURES WILL CONTINUE TO BE SIMILAR TO THOSE EXPECTED
IN LATE SPRING...WITH LOW TO MID 70S ACROSS THE MOUNTAINS...AND
UPPER 70S TO LOWER 80S ACROSS THE PIEDMONT.
SHOWER AND ISOLATED THUNDERSTORM ACTIVITY WILL CONTINUE THURSDAY
NIGHT AND EARLY FRIDAY MORNING...SPREADING TO THE PIEDMONTS AS THE
LOW PRESSURE SYSTEM CONTINUES TO PUSH EAST. THE INCREASED CLOUD
COVER WILL KEEP OVERNIGHT TEMPERATURES EXCEPTIONALLY WARM...WITH
LOWS EXPECTED TO FALL INTO THE LOW TO MID 50S ACROSS MOST AREAS.
SHOWER AND THUNDERSTORM ACTIVITY WILL INCREASE IN COVERAGE ON FRIDAY
AS THE LOW PRESSURE SYSTEM DRAGS A WEAK COLD FRONT ACROSS OUR AREA.
AGAIN...CANNOT RULE OUT THE POSSIBILITY OF ISOLATED STRONG
THUNDERSTORMS...BUT DO NOT ANTICIPATE ORGANIZED SEVERE WEATHER FOR
FRIDAY AFTERNOON. SHOWER ACTIVITY AND INCREASED CLOUD COVER WILL
KEEP FRIDAY HIGHS SLIGHTLY COOLER...WITH HIGHS RANGING FROM THE
UPPER 60S AND LOWER 70S ACROSS THE MOUNTAINS...TO THE MID TO UPPER
70S FURTHER EAST. SHOWER AND ISOLATED THUNDERSTORM ACTIVITY WILL
CONTINUE FOR OUR AREA ON SATURDAY AS THE SLOW MOVING COLD FRONT
LINGERS JUST TO THE SOUTH OF OUR REGION. SATURDAY HIGH TEMPERATURES
WILL RANGE FROM THE MID 60S TO THE LOWER 70S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 PM EDT TUESDAY...
SPOTTY SHOWER ACTIVITY WILL CONTINUE INTO SUNDAY AFTERNOON...BUT
WILL DIMINISH FROM NORTHEAST TO SOUTHWEST AS HIGH PRESSURE TAKES
CONTROL OF THE NEW ENGLAND STATES...AND WORKS ITS WAY SOUTH ALONG
THE EASTERN FACE OF THE APPALACHIANS. WITH ALMOST A SUMMER LIKE
WEATHER PATTERN IN PLACE...WILL LIKELY SEE SPOTTY SHOWERS AND
ISOLATED THUNDERSTORMS DEVELOP EACH AFTERNOON HEADING INTO THE NEXT
WORKWEEK...BUT THIS ACTIVITY SHOULD FIZZLE SHORTLY AFTER SUNSET.
AFTERNOON HIGHS FROM SUNDAY THROUGH TUESDAY WILL REMAIN MILD...
RANGING FROM THE UPPER 60S TO THE LOWER 70S...WHILE OVERNIGHT LOWS
WILL RANGE FROM THE MID 40S TO THE LOWER 50S.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
AS OF 125 PM EDT TUESDAY...
NO CHANGE IN AIR MASS IN EXPECTED TONIGHT OR WEDNESDAY. SURFACE
DEW POINTS WILL BE IN THE 50S AND WITH CLOUDS CLEARING OUT
OVERNIGHT...PATCHY FOG IN EXPECTED. HAVE MVFR FOG IN THE
LYH/DAN/BLF/LWB AND BCB TAFS OVERNIGHT. CONSIDERING CURRENT
DEWPOINT DEPRESSION...DAN LOOKS MOST FAVORABLE FOR VIS REDUCTIONS
TONIGHT AND POSSIBLY BRIEF IFR VIS. ANY FOG WILL DISSIPATE SHORTLY
AFTER SUNRISE ON WEDNESDAY.
WE CAN EXPECT MAINLY VFR CONDITIONS WEDNESDAY THROUGH
SUNDAY...ALTHOUGH CANNOT RULE OUT SOME SCATTERED SHOWERS MAINLY
IN THE WEST...ESPECIALLY ON THURSDAY AFTERNOON AND FRIDAY
AFTERNOON...AS MOIST SOUTHWEST FLOW REDEVELOPS ONCE HIGH PRESSURE
MOVES EAST OF THE AREA.
&&
.CLIMATE...
MARCH 14 MARCH 15
STATION RECORD...FORECAST RECORD...FORECAST
ROANOKE 86 IN 1990...81 82/1944...83
LYNCHBURG 85 IN 1973...81 80/1944...81
DANVILLE 89 IN 1990...82 88/1990...83
BLACKSBURG 77 IN 2007...76 82/1973...77
BLUEFIELD 80 IN 1990...76 76/1977...78
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/JH
SHORT TERM...NF
LONG TERM...NF
AVIATION...AMS/KM
CLIMATE...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
854 PM EDT TUE MAR 13 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL CROSS THE OHIO VALLEY AND NORTHEAST UNITED
STATES TONIGHT. HIGH PRESSURE WILL REMAIN OVER THE MID ATLANTIC
AND SOUTHEAST STATES THROUGH THURSDAY. ANOTHER WEAK COLD FRONT
WILL APPROACH THE REGION ON FRIDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 840 PM EDT TUESDAY...
ISOLATED CONVECTION CONTINUES JUST NW OF THE CWA THIS EVENING
AHEAD OF THE SFC COLD FRONT LAGGING BACK NEAR THE OHIO RIVER. WITH
A RIBBON OF RESIDUAL CAPE STILL OVER THE NW PER SPC MESO
ANALYSIS...MAY SEE SOME OF THIS COVERAGE MAKE A RUN AT THE FAR NW
ZONES BEFORE FADING IN THE NEXT HOUR OR TWO...AS LOW LEVELS REMAIN
QUITE DRY PER EVENING RAOBS/DEWPOINTS. LATEST HRRR AND LOCAL WRF
ALSO DISSIPATE ANY SHRA AFTER 10 PM SO ONLY PLANNING TO CARRY AN
ISOLATED MENTION AT BEST NW PENDING RELEASE COVERAGE. OTRW SHOULD
SEE ANY REMAINING CU FADE WITH LOSS OF HEATING ALLOWING FOR MAINLY
CLEAR SKIES AS THE SFC FRONT HANGS UP JUST TO THE NORTH BY
MORNING. WITH THE FLOW BECOMING LIGHT UNDER WEAK HIGH PRESSURE THE
OTHER CONCERN IS WITH FOG COVERAGE LATE ESPCLY SOUTH WHERE
MOISTURE IS A BIT HIGHER. LATEST RUC SOUNDINGS AND FOG STAB VALUES
DO SUPPORT AT LEAST PATCHY FOG IN THE VALLEYS BUT MORESO IN NW NC
WHERE BEEFED UP COVERAGE TO AREAS OF FOG LATE. MADE SMALL ADJUSTS
TO TEMPS TO RAISE VALUES ON THE RIDGES WITH STILL SOME 40S
POSSIBLE IN THE DEEPER VALLEYS.
PREVIOUS DISCUSSION AS OF 250 PM EDT TUESDAY...
WEAK SHORT WAVE ENERGY WILL BE MOVING WELL EAST OF THE FORECAST AREA
OVERNIGHT. WINDS FROM THE SURFACE THROUGH MID LEVEL WILL BECOME
NORTHWEST BY WEDNESDAY MORNING WHICH WILL SUPPRESS ANY DEVELOPMENT
OF PRECIPITATION EAST OF THE BLUE RIDGE ON WEDNESDAY.
MODELS HAVE THE TAIL END OF THE WEAK COLD FRONT CROSSING THE
NORTHEAST UNITED STATES JUST REACHING THE FAR NORTHERN COUNTY
WARNING AREA THIS EVENING. DEW POINTS MAY DROP BACK INTO THE 40S
NORTH OF THE FRONT OVERNIGHT...BUT OVERALL NO REAL CHANGE IN AIR
MASS TONIGHT OR WEDNESDAY. WITH SURFACE DEW POINTS STAYING THE
50S...HAVE ADDED FOG IN THE WESTERN VALLEYS TONIGHT.
STAYED CLOSE TO A BLEND OF BIAS CORRECTED MAV AND MET GUIDANCE FOR
LOWS TONIGHT AND HIGHS ON WEDNESDAY.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 300 PM EST TUESDAY...
WILL BE LOOKING AT A DIFFUSE WEATHER PATTERN THROUGH THE LATER HALF
OF THE WORKWEEK HEADING INTO THE WEEKEND. HIGH PRESSURE WILL SIT OFF
THE EAST COAST WEDNESDAY NIGHT AND THURSDAY...MAKING FOR SOUTHERLY
TO SOUTHWESTERLY WIND FLOW ACROSS OUR AREA. THIS FLOW WILL ALLOW THE
UNSEASONABLY WARM TEMPERATURES TO CONTINUE FOR THE EAST...AND WE CAN
EXPECT TEMPERATURES IN THE MID 40S TO LOWER 50S FOR WEDNESDAY NIGHT
LOWS. SPOTTY SHOWER ACTIVITY WILL MAKE ITS WAY INTO THE MOUNTAINS
THURSDAY MORNING...WITH THE POSSIBILITY OF A FEW SHOWERS DEVELOPING
INTO THUNDERSTORMS DURING THE MID AFTERNOON...AS A WEAK LOW PRESSURE
SYSTEM PASSES ALONG THE GREAT LAKES. CANNOT RULE OUT THE CHANCE OF A
STRONG THUNDERSTORM OR TWO DEVELOPING DURING THE AFTERNOON...BUT DO
NOT ANTICIPATE ANY ORGANIZED STRONG THUNDERSTORM ACTIVITY. THURSDAY
AFTERNOON TEMPERATURES WILL CONTINUE TO BE SIMILAR TO THOSE EXPECTED
IN LATE SPRING...WITH LOW TO MID 70S ACROSS THE MOUNTAINS...AND
UPPER 70S TO LOWER 80S ACROSS THE PIEDMONT.
SHOWER AND ISOLATED THUNDERSTORM ACTIVITY WILL CONTINUE THURSDAY
NIGHT AND EARLY FRIDAY MORNING...SPREADING TO THE PIEDMONTS AS THE
LOW PRESSURE SYSTEM CONTINUES TO PUSH EAST. THE INCREASED CLOUD
COVER WILL KEEP OVERNIGHT TEMPERATURES EXCEPTIONALLY WARM...WITH
LOWS EXPECTED TO FALL INTO THE LOW TO MID 50S ACROSS MOST AREAS.
SHOWER AND THUNDERSTORM ACTIVITY WILL INCREASE IN COVERAGE ON FRIDAY
AS THE LOW PRESSURE SYSTEM DRAGS A WEAK COLD FRONT ACROSS OUR AREA.
AGAIN...CANNOT RULE OUT THE POSSIBILITY OF ISOLATED STRONG
THUNDERSTORMS...BUT DO NOT ANTICIPATE ORGANIZED SEVERE WEATHER FOR
FRIDAY AFTERNOON. SHOWER ACTIVITY AND INCREASED CLOUD COVER WILL
KEEP FRIDAY HIGHS SLIGHTLY COOLER...WITH HIGHS RANGING FROM THE
UPPER 60S AND LOWER 70S ACROSS THE MOUNTAINS...TO THE MID TO UPPER
70S FURTHER EAST. SHOWER AND ISOLATED THUNDERSTORM ACTIVITY WILL
CONTINUE FOR OUR AREA ON SATURDAY AS THE SLOW MOVING COLD FRONT
LINGERS JUST TO THE SOUTH OF OUR REGION. SATURDAY HIGH TEMPERATURES
WILL RANGE FROM THE MID 60S TO THE LOWER 70S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 PM EDT TUESDAY...
SPOTTY SHOWER ACTIVITY WILL CONTINUE INTO SUNDAY AFTERNOON...BUT
WILL DIMINISH FROM NORTHEAST TO SOUTHWEST AS HIGH PRESSURE TAKES
CONTROL OF THE NEW ENGLAND STATES...AND WORKS ITS WAY SOUTH ALONG
THE EASTERN FACE OF THE APPALACHIANS. WITH ALMOST A SUMMER LIKE
WEATHER PATTERN IN PLACE...WILL LIKELY SEE SPOTTY SHOWERS AND
ISOLATED THUNDERSTORMS DEVELOP EACH AFTERNOON HEADING INTO THE NEXT
WORKWEEK...BUT THIS ACTIVITY SHOULD FIZZLE SHORTLY AFTER SUNSET.
AFTERNOON HIGHS FROM SUNDAY THROUGH TUESDAY WILL REMAIN MILD...
RANGING FROM THE UPPER 60S TO THE LOWER 70S...WHILE OVERNIGHT LOWS
WILL RANGE FROM THE MID 40S TO THE LOWER 50S.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 125 PM EDT TUESDAY...
NO CHANGE IN AIR MASS IN EXPECTED TONIGHT OR WEDNESDAY. SURFACE
DEW POINTS WILL BE IN THE 50S AND WITH CLOUDS CLEARING OUT
OVERNIGHT...PATCHY FOG IN EXPECTED. HAVE MVFR FOG IN THE
LYH/DAN/BLF/LWB AND BCB TAFS OVERNIGHT. CONSIDERING CURRENT
DEWPOINT DEPRESSION...DAN LOOKS MOST FAVORABLE FOR VIS REDUCTIONS
TONIGHT AND POSSIBLY BRIEF IFR VIS. ANY FOG WILL DISSIPATE SHORTLY
AFTER SUNRISE ON WEDNESDAY.
WE CAN EXPECT MAINLY VFR CONDITIONS WEDNESDAY THROUGH
SUNDAY...ALTHOUGH CANNOT RULE OUT SOME SCATTERED SHOWERS MAINLY
IN THE WEST...ESPECIALLY ON THURSDAY AFTERNOON AND FRIDAY
AFTERNOON...AS MOIST SOUTHWEST FLOW REDEVELOPS ONCE HIGH PRESSURE
MOVES EAST OF THE AREA.
&&
.CLIMATE...
MARCH 14 MARCH 15
STATION RECORD...FORECAST RECORD...FORECAST
ROANOKE 86 IN 1990...81 82/1944...83
LYNCHBURG 85 IN 1973...81 80/1944...81
DANVILLE 89 IN 1990...82 88/1990...83
BLACKSBURG 77 IN 2007...76 82/1973...77
BLUEFIELD 80 IN 1990...76 76/1977...78
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/JH
SHORT TERM...NF
LONG TERM...NF
AVIATION...AMS/KM
CLIMATE...
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
303 PM CDT MON MAR 12 2012
...NEAR OR ABOVE RECORD HIGHS EXPECTED THROUGHOUT MUCH OF THE
FORECAST...
.SHORT TERM...TONIGHT THROUGH THURSDAY
303 PM CDT MON MAR 12 2012
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT
ANALYSIS SHOWED SOUTHWEST FLOW FROM THE PACIFIC NORTHWEST TO
HUDSON BAY... WITH A SHORTWAVE TROUGH OVER SASKATCHEWAN. IN THE
SOUTHERN STREAM...AN UPPER LOW WAS NEAR EAU CLAIRE WITH A
SHORTWAVE ROUNDING ITS BASE OVER NORTHERN ILLINOIS. THIS LATTER
SHORTWAVE IS HELPING TO SUSTAIN SHOWERS AND A FEW THUNDERSTORMS
OVER SOUTHEAST WISCONSIN AND NORTHERN ILLINOIS...AIDED BY DAYTIME
HEATING. OTHER SHOWER ACTIVITY WAS OVER NORTHERN AND CENTRAL
WISCONSIN...AIDED BY DPVA FORCING AHEAD OF THE UPPER LOW. ANOTHER
AREA OF SHOWERS WERE WEST OF MINNEAPOLIS IN THE DEFORMATION ON THE
BACK SIDE OF THE UPPER LOW. THERE HAS BEEN SOME PARTIAL CLEARING
TODAY SOUTH OF I-90...THANKS TO DRY AIR WRAPPING AROUND THE UPPER
LOW. THIS CLEARING COMBINED WITH A WARM LAST NIGHT HAS ALLOWED
TEMPERATURES TO CLIMB MOSTLY INTO THE 50S...DESPITE 850MB TEMPS
WHICH HAVE DROPPED TO 2-4C PER RUC ANALYSIS...AND THE 3C READING
AT OAX AT 12Z. MUCH WARMER AIR AT 850MB EXISTS OVER THE
DAKOTAS...THOUGH...WITH READINGS OF 12C AT BIS AND UNR AT 12Z.
TONIGHT AND TUESDAY...THE UPPER LOW OVER WESTERN WISCONSIN IS
PROGGED TO CONTINUE ITS NORTHEASTWARD TREK...LIFTING INTO NORTHEAST
ONTARIO BY 12Z TUESDAY. IT APPEARS THIS UPPER LOW WILL THEN SLOW
DOWN...DUE TO THE CURRENT SHORTWAVE TROUGH IN SASKATCHEWAN WHICH
MODELS HAVE IT PHASING WITH THE UPPER LOW. THE ONLY IMPACTS THIS
PHASING HAS ON OUR FORECAST AREA IS NORTH OF I-94 TUESDAY
MORNING...WHERE SLIGHTLY COOLER AND DRIER AIR WILL MOVE IN.
OTHERWISE...850MB TEMPS ARE PROGGED TO BE ON THE RISE THROUGHOUT
THIS TIME PERIOD. AT 12Z TUESDAY...THEY SHOULD RANGE FROM
4-8C...THEN RISE TO 8-12C BY 00Z WEDNESDAY. THIS WARMING COMBINED
WITH CLEARING SKIES AND DRIER AIR FOR TUESDAY SHOULD RESULT IN
DECENT MIXING. STAYED TOWARD THE HIGH END OF GUIDANCE FOR HIGHS
WHICH PUTS THEM CLOSE TO OR ABOVE RECORD VALUES. REGARDING TONIGHTS
LOWS...PRECIPITABLE WATER VALUES ARE FORECAST TO DROP TO 0.25 INCH
BY 12Z OR LOWER AFTER BEING UP BETWEEN 0.5-0.75 INCHES. THIS DRY AIR
SHOULD HELP TEMPERATURES DROP...THOUGH WINDS KIND OF STAY UP THROUGH
MUCH OF THE NIGHT UNTIL LATE. THEREFORE HAVE TAKEN A BLEND OF
GUIDANCE APPROACH. COULD HAVE SOME PATCHY FOG WHERE WINDS CAN
DECOUPLE DUE TO RECENT RAINS...WHILE THE OVERALL WIND ESPECIALLY
RIGHT ABOVE THE SURFACE KEEPS THE FOG FROM BECOMING MORE WIDESPREAD.
TUESDAY NIGHT THROUGH THURSDAY...A BIG CHUNK OF THE UPPER TROUGHING
CURRENTLY OFF THE PACIFIC NORTHWEST COAST IS FORECAST TO LIFT OUT
INTO SOUTHWEST CANADA TUESDAY NIGHT...THEN UP TO HUDSON BAY BY
WEDNESDAY NIGHT. A STRONG LOW PRESSURE SYSTEM DEVELOPS FROM THIS
UPPER TROUGHING...THOUGH AGAIN WELL OFF TO OUR NORTH. HOWEVER...
THERE ARE GOING TO BE SOME IMPACTS FROM IT. FIRST...A SURGE OF WARM
AIR CAUSED BY DOWNSLOPING OFF THE ROCKIES WILL MOVE INTO THE AREA.
THE FIRST FEELING OF THIS COMES TUESDAY NIGHT AS INCREASING
SOUTHEAST TO SOUTH WINDS BRING HIGHER DEWPOINTS AND 850MB TEMPS RISE
TO 12-14C. THIS SITUATION MAY KEEP TEMPERATURES FROM FALLING BELOW
50 ALONG AND WEST OF THE MISSISSIPPI RIVER. ON WEDNESDAY...WINDS
TURN SOUTHWEST AHEAD OF THE LOW PRESSURE SYSTEMS COLD FRONT
CROSSING MINNESOTA. THERE ARE INDICATIONS FROM THE 12.12Z NAM/ECMWF
THAT 850MB TEMPS COULD EVEN RISE TO 16C OVER NORTHEAST IOWA...ALMOST
3 STANDARD DEVIATIONS ABOVE NORMAL. WITH PLENTY OF SUN AND A WARM
START...TEMPERATURES SHOULD EASILY CLIMB INTO THE 70S. AN 80F
READING MAY EVEN OCCUR (NOTE 81F HIGH FOR SPARTA OFF MET GUIDANCE).
DEWPOINTS ARE ALSO EXPECTED TO CLIMB INTO THE 50S WITH A GOOD FETCH
COMING OUT OF THE GULF OF MEXICO. THE COMBINATION OF THE
UNPRECEDENTED WARMTH AND DEWPOINTS WILL LIKELY LEAD TO CUMULUS
DEVELOPMENT...MAKING IT FEEL MORE LIKE LATE SPRING THAN MID MARCH.
FOR WEDNESDAY NIGHT INTO THURSDAY...THE UPPER FLOW TURNS A LITTLE
MORE TOWARDS WEST...ENOUGH TO ALLOW THE WEAKENING COLD FRONT TO MOVE
INTO THE FORECAST AREA. BELIEVE THE 12.12Z NAM IS TOO AGGRESSIVE ON
THE SPEED GIVEN THE 12.12Z GFS/UKMET/ECMWF SLOWER. IN ANY EVENT...
THE FRONT WILL RE-ORIENT ITSELF WEST-EAST...LIKELY OCCURRING ON
THURSDAY NEAR OR JUST SOUTH OF I-90. CONVECTIVE INITIATION ON THE
FRONT DOES NOT SEEM LIKELY...DUE TO CAPPING. THE 12.12Z GFS DOES TRY
TO SPIT OUT THESE VERY LIGHT QPF VALUES...BUT THIS IS MORE FROM THE
MODEL BRINGING IN TOO MUCH LOW LEVEL MOISTURE AND GENERATING
STRATUS/DRIZZLE VERSUS CONVECTION. EVEN THEN...THE PATTERN DOES NOT
FAVOR STRATUS/DRIZZLE AND THE MODEL SEEMS TO HAVE A HIGH MOISTURE
BIAS. EVEN WITH THE FRONTAL PASSAGE...850MB TEMPS ONLY DROP TO
10-12C SO THURSDAY MAY ONLY END UP A LITTLE COOLER THAN WEDNESDAY.
WEDNESDAY NIGHT ALSO LIKELY STAYING MILD...ESPECIALLY AHEAD OF THE
FRONT.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
303 PM CDT MON MAR 12 2012
MAIN STORY REMAINS THE UNPRECEDENTED WARMTH WHICH LOOKS TO PERSIST
THROUGH THE ENTIRE LONG TERM PERIOD AND BEYOND.
VERY GOOD MODEL AGREEMENT EXISTS THAT A DEEP UPPER LEVEL TROUGH IS
GOING TO DEVELOP ALONG THE WEST COAST OF THE U.S. FRIDAY INTO
SATURDAY. AS A RESULT...RIDGING BUILDS DOWNSTREAM OVER THE CENTRAL
AND EASTERN U.S.. THIS RIDGE BECOMES QUITE STRONG AND ACCORDING TO
THE CFS V2 MODEL...IT MAY PERSIST RIGHT THROUGH THE END OF THE
MONTH...WHILE THE WEST COAST TROUGH STAYS PUT OR CUTS-OFF. SINCE THE
CFS HAS BEEN DOING VERY WELL OVER THE PAST FEW MONTHS...HAVE
PREFERRED MODEL SCENARIOS WHICH KEEP THE WESTERN TROUGH IN
PLACE...WHICH LUCKILY MOST MODELS DO INCLUDING THE NEW 12.12Z ECMWF.
FOLLOWING THIS IDEA...850MB TEMPS THROUGHOUT THE LONG TERM PERIOD
STAY BETWEEN 10-14C OR 2-2.5 STANDARD DEVIATIONS ABOVE NORMAL. THIS
WOULD MEAN HIGHS NEAR OR ABOVE RECORD HIGHS. HAVE ADJUSTED ALL HIGH
TEMPERATURES TOWARDS THE HIGH END OF GUIDANCE. A PERSISTENT SOUTH
WIND OF 20-40 KT AT 925MB WILL HELP TO KEEP A PULL OF MOISTURE OUT
OF THE GULF OF MEXICO...THOUGH LACK OF VEGETATION AND THE DISTANCE
FROM THE GULF SHOULD HOLD DEWPOINTS BELOW 60. WITH THE WARM
TEMPERATURES AND DEWPOINTS...ANTICIPATING A LOT OF PARTLY SUNNY DAYS
DUE TO CUMULUS DEVELOPMENT.
PRECIPITATION CHANCES ARE VERY UNCERTAIN AND IT IS ENTIRELY POSSIBLE
THAT THE WHOLE LONG TERM PERIOD ENDS UP DRY. HOWEVER...WITH THE WELL
ABOVE NORMAL DEWPOINTS INTERACTING WITH WEAK SHORTWAVES COMING OUT
OF THE PACIFIC THROUGH THE BUILDING RIDGING...CANNOT RULE OUT A FEW
PERIODS OF SHOWERS AND THUNDERSTORMS. HAVE 20-30 PERCENT CHANCES
THROUGHOUT MUCH OF THE LONG TERM AS A RESULT. MUST BE STRESSED THAT
MUCH OF THIS PERIOD WILL LIKELY BE DRY.
&&
.AVIATION...THROUGH 18Z TUESDAY
1232 PM CDT MON MAR 12 2012
17Z WATER VAPOR IMAGERY SHOWS MID LEVEL LOW NOW OVER WEST CENTRAL
WISCONSIN. THIS LOW WILL CONTINUE TO LIFT NORTHEAST AWAY FROM THE
AREA. CEILINGS HAVE BEEN UNDULATING BETWEEN MVFR AND VFR SINCE
LATE MORNING...AS VISIBLE SATELLITE IMAGERY SHOWS SOME HOLES IN
THE CLOUDS. EXPECT THIS TREND TO CONTINUE THIS AFTERNOON AND WITH
SOME WEAK INSTABILITY WILL LIKELY SEE SOME SCATTERED SHOWERS THAT
MAY AFFECT THE TAF SITES FROM TIME TO TIME THROUGH 21Z. SURFACE
RIDGE MOVES IN FROM THE WEST TONIGHT. MODEL CONSENSUS IS FOR CLOUDS
TO CLEAR OUT BETWEEN 03Z-05Z WITH SKC AFTER THAT. WITH RIDGE AXIS
PUSHING INTO SOUTHEAST MINNESOTA LATE TONIGHT...QUESTION WILL BE
FOG POTENTIAL. BOTH THE 14.00Z NAM AND 14.15Z RUC BUFKIT SOUNDINGS
SHOWING WINDS AT THE SURFACE AROUND 5 TO 7 KNOTS...AND 10 TO 15
KNOTS JUST ABOVE THE SURFACE. CONFIDENCE CERTAINLY NOT HIGH FOR
ANY GOG. DID INCLUDE A 6SM BR AT BOTH SITES. LATER SHIFTS WILL
HAVE TO MONITOR WINDS AND IF LIGHTER MAY HAVE TO LOWER
VISIBILITIES.
&&
.CLIMATE...THROUGH EARLY NEXT WEEK
303 PM CDT MON MAR 12 2012
WELL ABOVE NORMAL TEMPERATURES ARE EXPECTED THROUGHOUT MUCH OF THE
NEXT 7 DAYS AND LIKELY BEYOND. AT LA CROSSE AND ROCHESTER...THE NEXT
3 DAYS APPEAR TO BE RELATIVE MINIMUMS FOR WHAT THE GOING RECORDS
ARE...SO ANY OF THE DAYS WILL HOLD A CHANCE FOR BREAKING THE RECORD.
WEDNESDAY STILL LOOKS LIKE THE WARMEST DAY OF THE WEEK AND HOLDS THE
HIGHEST POTENTIAL FOR BREAKING THE RECORDS WITH HIGHS EXPECTED IN
THE 70S. A FEW PLACES COULD EVEN APPROACH 80. HEADING INTO THE
WEEKEND AND EARLY NEXT WEEK...RECORDS VARY IN TERMS OF HOW HIGH THEY
ARE...BUT DEFINITELY POTENTIAL EXISTS FOR MORE RECORDS TO BE BROKEN.
SEE OUR WEBSITE FOR A LISTING OF RECORD HIGHS THROUGH EARLY NEXT
WEEK.
&&
.HYDROLOGY...
1232 PM CDT MON MAR 12 2012
ACCORDING TO OFFICIALS THERE HAVE BEEN SOME LOCALIZED ICE BLOCKAGES
ALONG THE BLACK RIVER FROM AROUND THE NEILLSVILLE AREA DOWN TO THE
UPPER PORTION OF LAKE ARBUTUS NEAR HATFIELD. REPORTS INDICATE THAT
THERE ARE LARGE BLOCKS OF ICE MOVING DOWN THE RIVER...AND THEY ARE
OCCASIONALLY GETTING HUNG UP ON RIVER BENDS AND WHERE ROCKS CAUSE
CONSTRICTIONS IN THE RIVER.
AT THIS POINT...IT DOES NOT APPEAR THERE IS A LARGE RISK FOR
FLOODING DUE TO ICE JAMS. BUT THERE IS A RISK FOR RAPID WITHIN-BANK
RISES ALONG THE BLACK RIVER DUE TO THIS ICE ACTION. WE HAVE ALREADY
SEEN SOME RISES ON THE RIVER MONITORING GAUGES IN THAT AREA.
THERE IS STILL SOME SNOW COVER OVER THE HEADWATER OF THE BLACK RIVER
BASIN...FROM WITHEE UP TO MEDFORD. WITH THE WARM TEMPERATURES
EXPECTED THIS WEEK...THAT SNOW IS EXPECTED TO MELT AND RUNOFF
QUICKLY INTO THE RIVER. THE ICE THAT REMAINS IN THE RIVER IS
EXPECTED TO BREAK UP AND MOVE DOWNSTREAM...SO WATER LEVELS WILL NEED
TO BE MONITORED THIS WEEK AS THAT COMBINATION WILL LEAD TO HIGHER
WATER ALONG THE BLACK RIVER THIS WEEK.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
303 PM CDT MON MAR 12 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
CLIMATE...AJ
HYDROLOGY...MW
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1232 PM CDT MON MAR 12 2012
.SHORT TERM...TODAY THROUGH THURSDAY
315 AM CDT MON MAR 12 2012
THE MAIN FOCUS IN THE SHORT TERM IS WITH THE RAIN SHOWERS AND
POSSIBLE THUNDERSTORMS TODAY FOLLOWED BY THE RETURN OF NEAR RECORD
BREAKING TEMPERATURES THROUGH MID WEEK.
A MID TO UPPER LEVEL LOW CURRENTLY CENTERED OVER THE IOWA/NEBRASKA
BORDER WILL CONTINUE TO PROPAGATE NORTHEASTWARD INTO THE UPPER
MISSISSIPPI RIVER VALLEY BEFORE GETTING INTO THE GREAT LAKES BY
THIS EVENING. THE LEADING MOISTURE CHANNEL OUT OF THE GULF HAS
PUSHED INTO THE REGION WITH A NORTHWARD ADVANCING LIGHT TO
MODERATE RAIN BAND THAT IS ALREADY CLEAR OF NORTHEAST IOWA. THIS
BAND OF RAIN WILL CONTINUE TO MOVE NORTHWARD THIS MORNING WITH
MORE SCATTERED RAIN SHOWERS TO CONTEND WITH THROUGH THE REST OF
THE DAYTIME HOURS AS THE CORE OF THE LOW APPROACHES FROM THE
SOUTHWEST. THESE SHOWERS SHOULD END FROM WEST TO EAST THIS
AFTERNOON AND EVENING AS THE CORE OF THE TROUGH PASSES THROUGH.
THE MAIN QUESTION ABOUT TODAY IS WHETHER ANY CONVECTION WILL BE
ABLE TO DEVELOP...PARTICULARLY ACROSS WESTERN WISCONSIN. AS THE
CORE OF THE MID LEVEL LOW MOVES IN...THE LOW TO MID LEVEL PORTION
OF THE ATMOSPHERE WILL COOL WHICH WILL STEEPEN THE LAPSE RATES
ACROSS MUCH OF THE REGION. HOW MUCH INSTABILITY CAN DEVELOP WILL
DEPEND ON SURFACE TEMPERATURES WHICH WILL LIKELY BE HAMPERED BY A
BROKEN TO OVERCAST LOW LEVEL CLOUD DECK THIS MORNING AND
AFTERNOON. BY THE TIME ANY CLEARING STARTS TO GET IN...THE BETTER
FORCING WILL BE OFF TO THE EAST IN THE GREAT LAKES. WIND SHEAR
PROFILES GET BETTER THE FURTHER SOUTH AND EAST YOU GET FROM
WESTERN WISCONSIN AS A 70KT 500MB JET STREAK ROUNDS THE BASE OF
THE TROUGH FROM NORTHERN ILLINOIS INTO WESTERN MICHIGAN. THE
12.00Z NAM AND GFS BOTH DO PRODUCE A FEW HUNDRED J/KG OF MUCAPE
LATE THIS MORNING AND EARLY AFTERNOON BEFORE THE FORCING SHIFTS
OFF TO THE EAST...SO THE SLIGHT CHANCES FOR THUNDER STILL LOOK
WARRANTED. ANYTHING ORGANIZED...HOWEVER...SHOULD STAY OFF TO THE
EAST OF THE FORECAST AREA WHERE THE FORCING...SHEAR AND
INSTABILITY WILL BE BETTER MAXIMIZED.
SKIES WILL CLEAR OUT TONIGHT AS A RIDGE OF HIGH PRESSURE FOLLOWS
QUICKLY ON THE HEELS OF THIS SYSTEM WITH THE RIDGE AXIS MOVING
THROUGH THE FORECAST AREA BY TUESDAY NIGHT. AS A
RESULT...TEMPERATURES WILL QUICKLY REBOUND AS THE LOW LEVEL FLOW
COMES BACK AROUND TO THE SOUTH. THIS LOW LEVEL WARM AIR ADVECTION
WILL INCREASE GOING INTO WEDNESDAY WITH 850MB TEMPERATURES WARMING
TO AROUND +17C OFF OF THE 12.00Z NAM AND GFS. THIS LEADS TO 850MB
TEMPERATURE ANOMALIES OF +2 TO +3 STANDARD DEVIATIONS ON
WEDNESDAY...WHICH IS TYPICAL OF RECORD BREAKING TEMPERATURES.
THUS...WITH FORECAST SOUNDINGS LOOKING VERY DRY AND CAPPED...HAVE
BUMPED HIGHS INTO THE LOW TO MID 70S ACROSS MUCH OF THE REGION
WHICH WOULD LIKELY BREAK MANY RECORDS. THE COLD FRONT NOW IS BEING
FORECAST TO COME THROUGH THE REGION WEDNESDAY NIGHT...BUT DOES NOT
APPEAR TO HAVE PRECIPITATION FORM ALONG IT UNTIL IT IS INTO THE
GREAT LAKES REGION WHEN THE MID LEVEL FORCING STRENGTHENS.
.LONG TERM...THURSDAY NIGHT THROUGH SUNDAY NIGHT
315 AM CDT MON MAR 12 2012
THE MAIN CERTAINTY IN THE EXTENDED TIME FRAME IS THAT WITH THE
SOUTHWESTERLY FLOW ALOFT...OUR TEMPERATURES WILL REMAIN WELL ABOVE
NORMAL WITH MORE RECORDS POSSIBLY GOING DOWN. OTHERWISE...THE
12.00Z GFS AND ECMWF CONTINUE TO HINT AT SOME ENHANCED LOW LEVEL
MOISTURE TRANSPORT GOING INTO NEXT WEEKEND AS THE TROUGH STARTS TO
DIG SOUTH ACROSS THE ROCKIES. THIS MAY LEAD TO SOME DIURNAL SHOWER
AND THUNDERSTORM CHANCES THROUGH MUCH OF THE EXTENDED. THE TIMING
OF ANY MID LEVEL SHORT WAVE TROUGHS EJECTING NORTHEASTWARD OUT OF
THIS FLOW IS FAIRLY UNCERTAIN AT THIS POINT WITH THE EXTENDED
GUIDANCE NOT MATCHING UP WELL WITH THESE FEATURES. FOR NOW...HAVE
SOME LOW CHANCES FOR SHOWERS/THUNDER GOING THROUGH A GOOD CHUNK OF
THE EXTENDED PERIOD...BUT THESE LIKELY WOULD NOT BE ALL DAY RAINS.
&&
.AVIATION...THROUGH 18Z TUESDAY
1232 PM CDT MON MAR 12 2012
17Z WATER VAPOR IMAGERY SHOWS MID LEVEL LOW NOW OVER WEST CENTRAL
WISCONSIN. THIS LOW WILL CONTINUE TO LIFT NORTHEAST AWAY FROM THE
AREA. CEILINGS HAVE BEEN UNDULATING BETWEEN MVFR AND VFR SINCE
LATE MORNING...AS VISIBLE SATELLITE IMAGERY SHOWS SOME HOLES IN
THE CLOUDS. EXPECT THIS TREND TO CONTINUE THIS AFTERNOON AND WITH
SOME WEAK INSTABILITY WILL LIKELY SEE SOME SCATTERED SHOWERS THAT
MAY AFFECT THE TAF SITES FROM TIME TO TIME THROUGH 21Z. SURFACE
RIDGE MOVES IN FROM THE WEST TONIGHT. MODEL CONSENSUS IS FOR CLOUDS
TO CLEAR OUT BETWEEN 03Z-05Z WITH SKC AFTER THAT. WITH RIDGE AXIS
PUSHING INTO SOUTHEAST MINNESOTA LATE TONIGHT...QUESTION WILL BE
FOG POTENTIAL. BOTH THE 14.00Z NAM AND 14.15Z RUC BUFKIT SOUNDINGS
SHOWING WINDS AT THE SURFACE AROUND 5 TO 7 KNOTS...AND 10 TO 15
KNOTS JUST ABOVE THE SURFACE. CONFIDENCE CERTAINLY NOT HIGH FOR
ANY GOG. DID INCLUDE A 6SM BR AT BOTH SITES. LATER SHIFTS WILL
HAVE TO MONITOR WINDS AND IF LIGHTER MAY HAVE TO LOWER
VISIBILITIES.
&&
.CLIMATE...THIS WEEK
315 AM CDT MON MAR 12 2012
WITH ABOVE NORMAL TEMPERATURES TO CONTINUE THROUGH THE NEXT
WEEK...THERE WILL BE MANY OPPORTUNITIES TO BREAK THE RECORD HIGHS
AND HIGH MINIMUMS. AT LA CROSSE AND ROCHESTER...THE NEXT 5 DAYS
APPEAR TO BE RELATIVE MINIMUMS FOR WHAT THE GOING RECORDS ARE...SO
ANY OF THE DAYS THIS WEEK BESIDE TODAY WILL HOLD A CHANCE FOR
BREAKING THE RECORD. WEDNESDAY WILL LIKELY BE THE WARMEST OF THE
WEEK AND HOLDS THE HIGHEST POTENTIAL FOR BREAKING THE RECORDS WITH
HIGHS EXPECTED TO BE IN THE LOW TO MID 70S ACROSS THE REGION.
&&
.HYDROLOGY...
1232 PM CDT MON MAR 12 2012
ACCORDING TO OFFICIALS THERE HAVE BEEN SOME LOCALIZED ICE BLOCKAGES
ALONG THE BLACK RIVER FROM AROUND THE NEILLSVILLE AREA DOWN TO THE
UPPER PORTION OF LAKE ARBUTUS NEAR HATFIELD. REPORTS INDICATE THAT
THERE ARE LARGE BLOCKS OF ICE MOVING DOWN THE RIVER...AND THEY ARE
OCCASIONALLY GETTING HUNG UP ON RIVER BENDS AND WHERE ROCKS CAUSE
CONSTRICTIONS IN THE RIVER.
AT THIS POINT...IT DOES NOT APPEAR THERE IS A LARGE RISK FOR
FLOODING DUE TO ICE JAMS. BUT THERE IS A RISK FOR RAPID WITHIN-BANK
RISES ALONG THE BLACK RIVER DUE TO THIS ICE ACTION. WE HAVE ALREADY
SEEN SOME RISES ON THE RIVER MONITORING GAUGES IN THAT AREA.
THERE IS STILL SOME SNOW COVER OVER THE HEADWATER OF THE BLACK RIVER
BASIN...FROM WITHEE UP TO MEDFORD. WITH THE WARM TEMPERATURES
EXPECTED THIS WEEK...THAT SNOW IS EXPECTED TO MELT AND RUNOFF
QUICKLY INTO THE RIVER. THE ICE THAT REMAINS IN THE RIVER IS
EXPECTED TO BREAK UP AND MOVE DOWNSTREAM...SO WATER LEVELS WILL NEED
TO BE MONITORED THIS WEEK AS THAT COMBINATION WILL LEAD TO HIGHER
WATER ALONG THE BLACK RIVER THIS WEEK.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
1209 AM CDT MON MAR 12 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...RABERDING
CLIMATE...HALBACH
HYDROLOGY...MW
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1151 PM CDT SUN MAR 11 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY
255 PM CDT SUN MAR 11 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION TONIGHT INTO MONDAY AS
WELL AS THE ABOVE NORMAL TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED AN UPPER TROUGH FROM THE NORTHEAST PACIFIC INTO THE PACIFIC
NORTHWEST...THEN ZONAL FLOW FROM MANITOBA EAST INTO QUEBEC. IN THE
SOUTHERN STREAM...AN UPPER LOW WAS OVER THE OKLAHOMA PANHANDLE WITH
RIDGING BUILDING DOWNSTREAM INTO THE UPPER MISSISSIPPI RIVER VALLEY
REGION. AHEAD OF THE UPPER LOW...SHOWERS AND EMBEDDED THUNDERSTORMS
EXTENDED FROM FAR SOUTHWEST IOWA INTO KANSAS...MISSOURI AND SOUTH TO
THE GULF COAST. THE PRECIPITATION WAS BEING FORCED FROM A NUMBER OF
FACTORS: DPVA AHEAD OF THE UPPER LOW THE BIG ONE...A STREAM OF LOW
LEVEL MOISTURE TRANSPORT NOTED BY 30-40 KT 925-850MB WINDS ON
PROFILER DATA...INSTABILITY PRODUCED BY DAYTIME HEATING ACTING WITH
THE UPPER LOW AND SURFACE DEWPOINTS CLIMBING INTO THE 40S AND 50S.
PRECIPITABLE WATER VALUES IN THE MOISTURE STREAM ARE 1-1.5 INCHES OR
200-270 PERCENT OF NORMAL PER 12Z RAOBS. OVER THE FORECAST
AREA...DRY AIR ON THE 12Z MPX AND DVN SOUNDINGS HAVE KEPT ANY CLOUD
COVERAGE AHEAD OF THE PRECIPITATION LIMITED TO CIRRUS AND MID-LEVEL
CLOUDS THUS FAR...AND THESE ARE JUST COMING INTO LOCATIONS ALONG AND
SOUTH OF I-90. WITH PLENTY OF SUN...850MB TEMPS BETWEEN 8-10C PER
12Z RAOB ANALYSIS AND A RELATIVELY BREEZY SOUTH WIND...TEMPERATURES
HAVE CLIMBED AGAIN INTO THE 60S TODAY.
TONIGHT AND MONDAY...UPPER LOW OVER THE CENTRAL PLAINS IS FORECAST
TO LIFT NORTHEAST...CROSSING THE AREA SHORTLY AFTER 12Z MONDAY...
THEN REACH LAKE SUPERIOR BY 00Z TUESDAY. THIS EJECTION IS IN
RESPONSE TO THE TROUGHING CURRENTLY OVER THE PACIFIC NORTHWEST
LIFTING INTO MANITOBA. PRETTY IMPRESSIVE 500MB HEIGHT FALLS PROGGED
TONIGHT INTO MONDAY MORNING...ANYWHERE BETWEEN 150 AND 200 METERS.
SO NEEDLESS TO SAY THE DYNAMIC FORCING IS REALLY STRONG. A STRONG
SURGE OF MOISTURE COMES UP AHEAD OF THE LOW...SEEN IN PRECIPITABLE
WATER PROGS OF AROUND 1 INCH OR 300 PERCENT OF NORMAL. THEREFORE...
THE DYNAMICS SHOULD HAVE NO PROBLEM BRINGING PRECIPITATION TO THE
AREA. DESPITE THE ABOVE NORMAL MOISTURE...NOT ANTICIPATING THIS TO
BE A HEAVY QPF EVENT FOR A NUMBER OF REASONS: THE HIGH AMOUNT OF
MOISTURE DOES NOT STICK AROUND LONG DUE TO THE UPPER LOW MOVING
QUICKLY...MUCAPE FROM THE NAM FOR MUCH OF THIS TIME PERIOD STAYS
BELOW 200 J/KG LIMITING THUNDERSTORMS TO ISOLATED AT BEST...NO UPPER
JET SUPPORT AND BEST 850MB MOISTURE TRANSPORT AIMED EAST OF HERE.
WHAT INSTABILITY DOES EXIST IS OVER WISCONSIN DURING THE DAY
MONDAY...THUS HAVE KEPT A SLIGHT CHANCE FOR THUNDER THEN. REGARDING
PRECIPITATION TRENDS IN THE FORECAST...SHOULD SEE SHOWERS MOVE IN
THIS EVENING OVER MUCH OF THE FORECAST AREA...THEN BECOME MORE
SCATTERED ON MONDAY AS THE UPPER LOW PULLS AWAY BUT ITS COLD POOL
ALOFT LINGERS. TEMPERATURES ARE LIKELY TO REMAIN MILD TONIGHT WITH
CLOUDS AND HIGHER DEWPOINTS MOVING IN. LITTLE CHANGE REQUIRED FOR
LOWS. HIGHS ON MONDAY ARE TRICKY GIVEN THAT ONLY SUN POTENTIAL WOULD
OCCUR IN THE AFTERNOON AND SOUTH OF I-90. FOR NOW STUCK WITH A BLEND
OF GUIDANCE...BUT IF CLOUDS STAY AROUND LONGER THAN FORECAST...HIGHS
MAY NEED TO BE COOLED.
MONDAY NIGHT THROUGH WEDNESDAY...UPPER LOW IS PROGGED TO MOVE
FURTHER AWAY FROM THE REGION WHILE A FEW NEW TROUGHS DROP DOWN INTO
THE PACIFIC NORTHWEST AND EJECT UP INTO CENTRAL CANADA. THE RESPONSE
OF ALL OF THIS IS TO BUILD RIDGING OVER THE UPPER MISSISSIPPI RIVER
VALLEY REGION...SENDING A SURGE OF WARMER AIR INTO THE FORECAST
AREA. 850MB TEMPS WHICH START OFF AT 4-8C AT 12Z TUESDAY ARE
FORECAST TO CLIMB TO 8-12C BY 00Z WEDNESDAY AND TO 12-14C FOR THE
WHOLE DAYTIME HOURS ON WEDNESDAY. THERE ARE EVEN SOME HINTS OF 16C
850MB TEMPS APPROACHING THE WESTERN PORTION OF THE FORECAST AREA ON
WEDNESDAY...AHEAD OF A DYING SURFACE COLD FRONT COMING INTO
MINNESOTA. THESE 850MB READINGS ARE 2-2.5 STANDARD DEVIATIONS ABOVE
NORMAL...FAVORING TEMPERATURES APPROACHING OR EXCEEDING RECORD HIGHS
GIVEN TOO THAT PLENTY OF SUN SHOULD OCCUR BOTH DAYS. LEANED TOWARDS
THE HIGH END OF ALL GUIDANCE AS A RESULT FOR HIGHS. SOME
PRECIPITATION NOTES. THE 11.12Z NAM SHOWS ELEVATED CONVECTION
BETWEEN 09-15Z WEDNESDAY OVER EASTERN IOWA AND FAR SOUTHWEST
WISCONSIN. THIS PRECIPITATION FORMS DUE TO THE PRESENCE OF A WEAK
SHORTWAVE...A WARM FRONT AND ELEVATED CAPE VALUES BETWEEN 1000-1500
J/KG. HOWEVER...THE 850MB DEWPOINT HELPING TO PRODUCE THIS CAPE IS
AROUND 10C...OR 8C HIGHER THAN THE ECMWF. THE GFS IS ALSO SLIGHTLY
LOWER. THEREFORE AM DISCOUNTING THE NAM AT THE PRESENT TIME. ON
WEDNESDAY...THE GFS SEEMS TO HAVE TOO MUCH MOISTURE AT AND BELOW
900MB...A KNOWN PROBLEM SEEN IN SOME RECENT WARM EVENTS...AND THUS
STRATUS AND DRIZZLE OUT. DISCOUNTING THIS SCENARIO AS WELL SINCE IT
DOES NOT AGREE WITH THE ECMWF/NAM/CANADIAN. LASTLY...ON WEDNESDAY
AFTERNOON THE NAM CONVECTS OVER EASTERN IOWA AND SOUTHERN
WISCONSIN...THOUGH THERE IS NO SURFACE TRIGGER. IN ADDITION...THE
MODEL BRINGS SURFACE DEWPOINTS INTO THE 60S WHICH SEEMS WAY TOO
HIGH. AS SUCH...HAVE FOLLOWED THE DRY ECMWF/CANADIAN SCENARIO.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
255 PM CDT SUN MAR 11 2012
GOOD MODEL AGREEMENT EXISTS THAT THE FLOW OF TROUGHS COMING INTO THE
PACIFIC NORTHWEST THEN LIFTING INTO NORTH CENTRAL CANADA PERSISTS
THROUGH THURSDAY NIGHT. THEN ON FRIDAY AND HEADING INTO THE
WEEKEND...ALL MODELS SHOW A REALLY DEEP TROUGH FORMING ALONG THE
WEST COAST OF THE U.S. THE 11.12Z GFS IS BY FAR THE MOST PROGRESSIVE
WITH A STRONG SHORTWAVE COMING OUT OF THIS TROUGH...RESULTING IN A
FRONT MOVING THROUGH THE AREA AT 12Z SUNDAY. THE 11.00Z/12Z ECMWF
AND 11.12Z CANADIAN KEEPS THIS SHORTWAVE WRAPPED IN THE TROUGH WHICH
SEEMS MORE REASONABLE. BASICALLY ALL THIS MEANS IS THAT THE FORECAST
AREA STAYS UNDER UPPER RIDGING AND IN THE WARM SECTOR. THERE IS ONE
POTENTIAL CAVEAT TO THE WARM SECTOR WHICH IS THE COLD FRONT FROM
WEDNESDAY OVER MINNESOTA. MODELS PROG THIS FRONT TO DIE AS IT COMES
INTO THE FORECAST AREA WEDNESDAY NIGHT AND THURSDAY...WHILE BECOMING
ORIENTED MORE WEST-EAST WITH THE UPPER FLOW. AT THIS TIME HAVE
MAINTAINED A CONSENSUS 20 PERCENT CHANCES FOR PRECIPITATION ON THUS
FRONT OVER SOUTHWEST WISCONSIN WEDNESDAY NIGHT...THEN IN NORTHEAST
IOWA ON THURSDAY. STILL...THINKING MUCH OF THIS PERIOD WILL END UP
DRY. AFTER THIS...IT BECOMES A LITTLE MORE DIFFICULT TO PINPOINT
WHEN PRECIPITATION OCCURS. AS THE UPPER LEVEL FLOW AMPLIFIES...THERE
ARE INDICATIONS OF A FEW SHORTWAVES RIDING THROUGH DURING THE FRIDAY
THROUGH SATURDAY NIGHT TIME PERIOD. DEPENDING ON THE MODEL THE
TIMING VARIES. FOR NOW HAVE STAYED WITH A CONSENSUS APPROACH WHICH
RESULTS IN MUCH OF THE FORECAST AREA HAVING 20-40 PERCENT CHANCES.
STRONGER UPPER RIDGING ON SUNDAY SHOULD PREVENT ANY PRECIPITATION.
THE MAIN STORY CONTINUES TO BE THE WARMTH. 850MB TEMPS ON AVERAGE
HOLD BETWEEN 10-14C...OR 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL.
THIS SHOULD HELP TO KEEP HIGH TEMPERATURES MOSTLY IN THE 70S AND
NEAR OR ABOVE RECORDS. PERHAPS THE ONLY EXCEPTION TO THIS MIGHT BE
ON THURSDAY OVER NORTH CENTRAL WISCONSIN ON THE NORTH SIDE OF THAT
DYING COLD FRONT. ALSO OF NOTE IS THAT LOW TEMPERATURES ARE GOING TO
BE VERY WARM FOR THIS TIME OF YEAR TOO...AIDED BY DEWPOINTS HOLDING
MAINLY IN THE 50S. IN FACT...LOWS COULD BE 10-15 DEGREES ABOVE
NORMAL HIGHS.
&&
.AVIATION...THROUGH 06Z TUESDAY
1151 PM CDT SUN MAR 11 2012
500MB LOW NOW OVER SOUTHERN NEBRASKA AND WILL CONTINUE TO LIFT
NORTHWARD OVERNIGHT AND BY IN NORTHWEST WISCONSIN BY 18Z MONDAY.
RAIN WAS SPREADING NORTHWARD OUT OF IOWA INTO SOUTHERN MINNESOTA
AND WILL OVERSPREAD THE TAF SITES BY ISSUANCE TIME. EXPECT
CEILINGS TO DROP INTO IFR CATEGORY AND REMAIN THERE THROUGH AT
LEAST 15Z-17Z. CEILINGS WILL THEN RISE INTO THE MVFR CATEGORY AS
THE LOW LIFTS AWAY FROM THE AREA. LIGHT RAIN SHOWERS LOOK TO
PERSIST THROUGH MUCH OF THE DAY...ENDING BY MID TO LATE AFTERNOON.
SURFACE RIDGE THEN BEGINS TO BUILD INTO THE REGION FROM THE WEST.
THIS WILL CLEAR SKIES OUT BETWEEN 03Z-0-6Z AT THE TAF SITES.
&&
.CLIMATE...
255 PM CDT SUN MAR 11 2012
RECORD HIGHS HAVE BEEN BROKEN AT KLSE AND KRST...JUST BARELY WITH
ONLY BEING 1 DEGREE ABOVE THEM...BUT RECORDS NONETHELESS. POTENTIAL
STILL EXISTS FOR A DEGREE OR TWO RISE SO RECORD EVENT REPORTS WILL
BE HELD UNTIL DAYTIME HEATING ENDS AROUND 5 PM.
BEING NEAR OR AT RECORDS FOR HIGHS WILL BE THE NORM HERE STARTING
TUESDAY AND LASTING PERHAPS INTO EARLY NEXT WEEK. AN ANOMALOUS WARM
PATTERN IS SETTING UP OVER THE FORECAST AREA. LOW TEMPERATURES COULD
EVEN BE HIGH ENOUGH THAT WE SET NEW RECORD HIGH MINIMUMS. SEE OUR
WEBSITE FOR DETAILS ON RECORD HIGHS.
&&
.HYDROLOGY...THROUGH MONDAY
255 PM CDT SUN MAR 11 2012
NOT MUCH IN THE WAY OF ANY CHANGES TO THE GOING FORECAST. SNOWPACK
IN TAYLOR COUNTY IS IN FULL MELT MODE NOW / PER NOHRSC SNOW PACK
TEMPERATURE ANALYSIS / AND WILL CONTINUE TO MELT DURING THE NEXT
COUPLE OF DAYS. FORECAST RAINFALL AMOUNTS ARE STILL IN THE 0.35 TO
0.60 INCH RANGE WHICH WILL LIKELY LEAD TO SOME RISES ALONG THE
BLACK AND TREMPEALEAU RIVERS...BUT STILL NOT UP TO FLOOD STAGE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
255 PM CDT SUN MAR 11 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
CLIMATE...AJ
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
333 AM EDT WED MAR 14 2012
.SHORT TERM /TODAY THROUGH THURSDAY NIGHT/...
SHORTWAVE THAT MOVED THROUGH THE AREA LAST NIGHT CONTINUES TO
PRESS TOWARD THE COAST...AS RIDGING BUILDS ACROSS THE SOUTHEAST.
OVERALL...SHORT-TERM MODEL MASS FIELDS ARE FAIRLY SIMILAR BUT HAVE
SIDED WITH THE GFS AS IT AND THE ECMWF ARE IN BETTER AGREEMENT...
NAM IS A LITTLE FASTER AND A LITTLE MORE AGGRESSIVE WITH THE
MOISTURE.
BEST DEEP MOISTURE WILL BE SHUNTED SOUTH TODAY BY THE EXITING
SHORTWAVE BUT WITH TEMPERATURES CLIMBING INTO THE 80S JUST ABOUT
EVERYWHERE PLUS PLENTIFUL SURFACE MOISTURE...MLCAPE VALUES THIS
AFTERNOON CLIMB TO ABOVE 1000 J/KG ACROSS THE AREA. HRRR AND LOCAL
WRF DO DEVELOP CONVECTION THIS AFTERNOON BUT MAINLY LIMIT IT TO
THE SOUTHWEST CORNER. FOR THESE REASONS...HAVE INCLUDED SLIGHT
CHANCE POPS BUT KEPT POPS CONFINED MAINLY SOUTH. VERY LITTLE SHEAR
TO WORK WITH /LESS THAN 30M2/S2 0-6KM SHEAR/ SO DO NOT EXPECT
CONVECTION TO REALLY ORGANIZE...BUT LAPSE RATES REMAIN PRETTY
STEEP /AROUND 7C/KM/. OVERALL DO NOT REALLY EXPECT ANY SEVERE
THUNDERSTORMS...HOWEVER CENTRAL GEORGIA DID SEE LARGE HAIL LAST
NIGHT SO IT CANNOT BE TOTALLY RULED OUT.
AS MENTIONED...HIGH TEMPS TODAY EXPECTED TO CLIMB INTO THE 80S
JUST ABOUT EVERYWHERE...WITH MID 80S POSSIBLE ON THURSDAY. TODAY/S
HIGHS REMAIN JUST BELOW RECORD VALUES BUT THURSDAY/S FORECAST DOES
INCLUDE SOME RECORDS...SEE CLIMATE SECTION BELOW.
ANOTHER SHORTWAVE MOVES ACROSS THE OHIO VALLEY THURSDAY NIGHT INTO
FRIDAY...THUS POPS RETURN TO NORTH GEORGIA LATE IN THE SHORT-
TERM. OVERALL A VERY SUMMER-LIKE PATTERN WITH WARM TEMPS...A MOIST
BOUNDARY LAYER...AND A HIGH CAPE LOW SHEAR ENVIRONMENT.
TDP
.LONG TERM /FRIDAY THROUGH TUESDAY/...
SUMMER HAS STARTED EARLY. A HIGH-AMPLITUDE RIDGE TAKES FIRM HOLD
OF THE EASTERN U.S. WITH GFS PUSHING 587 DM 500 MB HEIGHTS
THROUGH THE WEEKEND. ALL EXTENDED MODELS AND ENSEMBLES ARE
CONSISTENT IN THIS...SO CONFIDENCE IS FAIRLY HIGH FOR HIGHER THAN
NORMAL TEMPS. THEREFORE...I BUMPED MAX TEMPS UPWARD A FEW DEGREES
IN THE EXTENDED TO COUNTERACT MOS TENDENCIES TOWARD CLIMATOLOGICAL
NORMS. PRECIPITABLE WATER VALUES REMAIN MUCH HIGHER THAN NORMAL
FOR THIS PERIOD...SO INCREASED AFTERNOON POPS TO REFLECT
SCATTERED...SUMMER-LIKE CONVECTION FOR THE WEEKEND. GFS SLIDES
SLIGHTLY DRIER AIR MOVES INTO NORTH GEORGIA BY MONDAY...SO POP
CHANCES DIMINISH. AM NOT QUITE CONVINCED THIS WILL BE ENOUGH TO
ELIMINATE PRECIP CHANCES...ESPECIALLY WITH ONSHORE FLOW BEGINNING
AS SURFACE RIDGE CENTERS ON MID-ATLANTIC SEABOARD EARLY IN THE
WEEK. WILL GO WITH /LOW/ MOS POPS FOR NOW...BUT THEY MAY BE TOO
LOW.
27
&&
.CLIMATE...
RECORDS FOR 03-14
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 84 1918 33 1993 61 1933 16 1926
1918
KATL 82 1989 33 1993 64 1918 18 1993
1926
KCSG 84 1989 40 1993 65 1973 20 1993
1982
KMCN 85 1973 41 1993 67 1918 21 1926
1953
1918
RECORDS FOR 03-15
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 84 1921 43 1960 62 1990 19 1993
1989
KATL 81 1973 39 1901 64 1989 20 1993
1946
KCSG 83 1989 44 1960 66 1973 21 1993
KMCN 86 1977 42 1960 65 1990 20 1993
1973
RECORDS FOR 03-16
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 82 1945 37 1960 62 2002 19 1890
KATL 84 1945 34 1900 64 2002 18 1890
KCSG 85 2002 51 1969 65 2002 27 1988
1949
KMCN 87 1955 42 1900 65 1942 26 1916
RECORDS FOR 03-17
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 85 1945 39 2005 62 1945 23 1924
KATL 86 1945 38 1892 65 2002 23 1895
KCSG 88 2002 45 2005 67 2002 30 1981
1954
KMCN 88 1945 44 2005 65 1908 27 1988
RECORDS FOR 03-18
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 87 1921 45 1998 63 1908 23 1967
1941
1902
KATL 84 1982 30 1892 67 1908 20 1902
KCSG 89 1982 49 1988 64 1982 29 1967
KMCN 88 1908 43 1902 67 1908 28 2007
1941
RECORDS FOR 03-19
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 86 1982 45 1947 61 1908 22 1892
KATL 85 1982 44 1892 65 1927 17 1892
KCSG 88 1982 52 2001 66 1948 30 1985
1960
KMCN 88 1963 49 1947 64 1982 26 1967
1945 1902
1927
RECORDS FOR 03-20
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 86 1907 38 1906 62 1948 20 1923
KATL 86 1907 36 1906 67 1948 17 1923
KCSG 85 2004 46 2001 66 1982 31 1956
1996 1948 1949
KMCN 90 1907 45 1906 67 1907 23 1923
&&
.AVIATION...
06Z UPDATE...
MAINLY SKC CONDITIONS AT TAF/AFD TIME WILL ALLOW FOR GOOD
CONDITIONS FOR RADIATIONAL FOG TO FORM THIS MORNING...ALREADY
SEEING INTERMITTENT LIFR CONDITIONS AT MCN. FOR NOW...
ANTICIPATING MOST OTHER TAFS WILL BOTTOM OUT AT IFR BUT BRIEF LIFR
CONDITIONS POSSIBLE. EXPECT MORE OF A FOG THAN LOW CIG SCENARIO
THOUGH LIFR OR VLIFR VV CONDITIONS NOT OUT OF THE QUESTION...
ESPECIALLY AT MCN. VSBY IMPROVES AFTER 12Z WITH VFR CU DEVELOPING
THIS AFTERNOON... DISSIPATING TOWARD EVENING. WESTERLY WINDS
LIGHT...BELOW 5KT EXCEPT FOR ATL...THROUGH THE PERIOD.
//ATL CONFIDENCE...06Z UPDATE...
HIGH ON WINDS.
MEDIUM ON VFR CIGS AND IFR VSBY THROUGH 13Z...LOW ON POTENTIAL
IFR/LIFR CIGS AND LIFR VSBY.
HIGH ON CIGS/VSBY AFTER 13Z.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 82 54 85 58 / 10 10 10 20
ATLANTA 80 61 83 62 / 10 10 20 20
BLAIRSVILLE 75 51 76 54 / 10 10 20 30
CARTERSVILLE 80 51 81 54 / 10 10 20 20
COLUMBUS 83 58 85 61 / 20 10 10 10
GAINESVILLE 79 57 82 60 / 10 10 20 20
MACON 83 54 84 58 / 20 10 10 10
ROME 82 52 81 55 / 10 10 30 30
PEACHTREE CITY 81 50 82 54 / 20 10 10 10
VIDALIA 83 57 85 59 / 20 10 5 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
243 AM CDT WED MAR 14 2012
.DISCUSSION...
ISSUED 240 AM CDT WED MAR 14 2012
MAIN FOCUS CONTINUES TO BE WITH THE SUMMER-LIKE WEATHER EXPECTED
THE NEXT SEVERAL DAYS...AS WELL AS TIMING OF ANY SHOWERS AND
THUNDERSTORMS. HAVE GONE WITH HIGH TEMPERATURES IN THE UPPER 70S
TO LOWER 80S ALMOST EVERY DAY THROUGH TUESDAY...WITH HIGHS A
COUPLE DEGREES COOLER ON SATURDAY. WILL LIKELY BE SEEING TEMPERATURE
RECORDS BEING BROKEN EACH DAY OVER SOME PART OF THE FORECAST AREA
INTO EARLY NEXT WEEK.
SHORT TERM...TODAY THROUGH SATURDAY...
THE UPPER PATTERN WILL FEATURE A RIDGE BUILDING ACROSS THE CENTER
OF THE NATION...BECOMING MORE AMPLIFIED ON FRIDAY AND SATURDAY. A
WEAK FRONTAL BOUNDARY APPROACHING FROM THE NORTHWEST IS PROGGED TO
WASH OUT AS IT REACHES ILLINOIS. WHILE THE MODELS GENERALLY AGREE
ON THIS SCENARIO...THEY ARE ALL VARYING IN WHERE EXACTLY TO
GENERATE ANY SHOWERS AND STORMS. THE ABNORMALLY WARM TEMPS...AND
A WIDE-OPEN MOISTURE FLOW OFF THE GULF FOR THE FORESEEABLE
FUTURE...ALLOW FOR PLENTY OF INSTABILITY WITH CAPES RISING TO
OVER 2000 J/KG AND LITTLE CAP. ANY STORMS THAT FORM WILL HAVE THE
CAPABILITY TO APPROACH SEVERE LEVELS DURING PEAK HEATING. HOWEVER...
THERE IS NOT A LOT OF FOCUS ON ANY PARTICULAR BOUNDARY TO GET ANY
WIDESPREAD ACTIVITY GOING. HAVE TENDED TO GO WITH THE LOWEST POPS
ACROSS THE NORTHWEST CWA...BUT 30 TO 40 PERCENT POPS ARE
DOMINATING THROUGH THIS PART OF THE FORECAST.
LONG TERM...SUNDAY THROUGH TUESDAY...
THE RIDGE CONTINUES TO BUILD THROUGH THE WEEKEND...AS TROUGHING
ALONG THE WEST COAST INTENSIFIES. THIS DEEP TROUGH WILL BE PUSHING
TOWARD THE ROCKIES EARLY NEXT WEEK. HAVE KEPT SOME SLIGHT CHANCE
POPS INTO SUNDAY...BUT DRY WEATHER WILL PREVAIL AS HIGH PRESSURE
DOMINATES THE EASTERN HALF OF THE COUNTRY. GOING INTO MIDWEEK...
THE QUESTION WILL BE HOW FAST THE RIDGE BREAKS DOWN WITH THE
ANOMALOUSLY HIGH 500 MB HEIGHTS IN PLACE. THE ECMWF IS FASTER IN
THIS REGARD AS THE GFS HAS THE RIDGE MUCH STRONGER IN THE FIRST
PLACE. BUT...THE NEXT SIGNIFICANT PRECIPITATION CHANCE IS LIKELY
AS THIS TRANSITION OCCURS.
GEELHART
&&
.AVIATION...
ISSUED 1152 PM CDT TUE MAR 13 2012
SOME ADJUSTMENTS SEEM IN ORDER FOR THE 06Z TAFS IN REGARDS TO LOW
LEVEL MOISTURE AND THE PROSPECTS FOR MVFR CEILINGS LATER THIS
MORNING. SATELLITE IMAGES SHOW MEAGER AMOUNTS OF LOW CLOUDS COMING
UP THROUGH EASTERN OK EVEN THOUGH THE LOW LEVEL JET HAS VEERED TO
SOUTHWESTERLY AND INCREASED TO 45-55 KT AS PREDICTED. THE LATEST RUC
AND HRRR OUTPUT ARE NOW DELAYING THE ONSET OF LOW STRATOCU UNTIL
MIDDAY AND SUGGEST THAT CEILINGS WILL BE 3K-5K FT. THE 00Z GFS AND
NAM MODELS ARE SHOWING SIMILAR SOLUTIONS. SO WILL KEEP SOME TEMPO
MVFR FOG AROUND SUNRISE...BUT DELAY THE ONSET OF BROKEN CEILINGS TIL
AROUND 18Z AND HAVE THEM IN THE VFR RANGE. ONCE THEY ARRIVE...THE
CLOUDS SHOULD HANG ON THROUGH THE END OF THE TAF PERIOD AS THE
SOUTHERLY FLOW CONTINUES TO BRING MOISTURE NORTHWARD.
THE AIRMASS IS FORECAST TO BECOME UNSTABLE WEDNESDAY AFTERNOON WITH
DEWPOINTS OF 55-60F AND CAPE VALUES OF 1K-2K J/KG. HOWEVER UPPER
SUPPORT FOR ASCENT WILL BE MINIMAL WITH BROAD RIDGING ALOFT...AND A
LOW LEVEL FOCUS WILL BE ABSENT. THE ABUNDANCE OF CLOUDS WILL NOT
HELP MATTERS EITHER. THUS AN ISOLATED STORM MAY BE POSSIBLE ALMOST
ANYWHERE...BUT EXPECTED AERIAL COVERAGE AND LOW CONFIDENCE IN WHERE
STORMS MAY DEVELOP PRECLUDES A THUNDER MENTION IN THE TAFS AT THIS
TIME.
04
&&
.CLIMATE...
ISSUED 240 AM CDT WED MAR 14 2012
RECORD HIGHS FOR...WEDNESDAY.............THURSDAY
BLOOMINGTON........76 IN 2007............76 IN 2007
CHAMPAIGN..........78 IN 2007............76 IN 1995
DECATUR............78 IN 2007............78 IN 1995
EFFINGHAM..........81 IN 2007............79 IN 2007
LINCOLN............77 IN 1933............78 IN 1935
PEORIA.............76 IN 1995............77 IN 1935
SPRINGFIELD........75 IN 1971/75/2007....79 IN 1935/1995
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1152 PM CDT TUE MAR 13 2012
.DISCUSSION...
ISSUED 830 PM CDT TUE MAR 13 2012
QUIET WEATHER EXPECTED OVERNIGHT WITH ONLY A FEW CIRRUS DRIFTING BY.
FOG FORMATION WILL BE POSSIBLE AGAIN TOWARD DAWN...BUT NOT AS DENSE
AS THIS MORNING SINCE PROJECTED LOWS ARE SEVERAL DEGREES ABOVE THE
DEWPOINT. THIS WILL BE MAINLY AN AVIATION CONCERN. CURRENT
TEMPERATURES ARE HOLDING PRETTY CLOSE TO THE FORECAST CURVE...SO NO
CHANGES TO THE ONGOING FORECAST ANTICIPATED AT THIS TIME.
04
&&
.AVIATION...
ISSUED 1152 PM CDT TUE MAR 13 2012
SOME ADJUSTMENTS SEEM IN ORDER FOR THE 06Z TAFS IN REGARDS TO LOW
LEVEL MOISTURE AND THE PROSPECTS FOR MVFR CEILINGS LATER THIS
MORNING. SATELLITE IMAGES SHOW MEAGER AMOUNTS OF LOW CLOUDS COMING
UP THROUGH EASTERN OK EVEN THOUGH THE LOW LEVEL JET HAS VEERED TO
SOUTHWESTERLY AND INCREASED TO 45-55 KT AS PREDICTED. THE LATEST RUC
AND HRRR OUTPUT ARE NOW DELAYING THE ONSET OF LOW STRATOCU UNTIL
MIDDAY AND SUGGEST THAT CEILINGS WILL BE 3K-5K FT. THE 00Z GFS AND
NAM MODELS ARE SHOWING SIMILAR SOLUTIONS. SO WILL KEEP SOME TEMPO
MVFR FOG AROUND SUNRISE...BUT DELAY THE ONSET OF BROKEN CEILINGS TIL
AROUND 18Z AND HAVE THEM IN THE VFR RANGE. ONCE THEY ARRIVE...THE
CLOUDS SHOULD HANG ON THROUGH THE END OF THE TAF PERIOD AS THE
SOUTHERLY FLOW CONTINUES TO BRING MOISTURE NORTHWARD.
THE AIRMASS IS FORECAST TO BECOME UNSTABLE WEDNESDAY AFTERNOON WITH
DEWPOINTS OF 55-60F AND CAPE VALUES OF 1K-2K J/KG. HOWEVER UPPER
SUPPORT FOR ASCENT WILL BE MINIMAL WITH BROAD RIDGING ALOFT...AND A
LOW LEVEL FOCUS WILL BE ABSENT. THE ABUNDANCE OF CLOUDS WILL NOT
HELP MATTERS EITHER. THUS AN ISOLATED STORM MAY BE POSSIBLE ALMOST
ANYWHERE...BUT EXPECTED AERIAL COVERAGE AND LOW CONFIDENCE IN WHERE
STORMS MAY DEVELOP PRECLUDES A THUNDER MENTION IN THE TAFS AT THIS
TIME.
04
&&
.PREV DISCUSSION...
ISSUED 211 PM CDT TUE MAR 13 2012
BIGGEST DIFFERENCES IN MODELS FOCUS ON STRENGTH OF RIDGE EARLY NEXT
WEEK. EITHER WAY...TEMPS SHOULD CONTINUE TO BE WELL ABOVE NORMAL
FOR THE FORSEEABLE FUTURE.
SHORT TERM...TONIGHT THROUGH SATURDAY
ENHANCE MOISTURE CONVERGENCE ALONG THE REMNANTS OF A DISSIPATING
COLD FRONT BROUGHT PATCHY DENSE FOG TO THE REGION LAST NIGHT. DRIER
AIR HAS ADVECTED IN TODAY AND WOULD NOT EXPECT QUITE THE COVERAGE OR
LOW VISIBILITIES ACROSS THE REGION WEDNESDAY MORNING AS THIS
MORNING. SOME PATCHY FOG REMAINS POSSIBLE.
MODELS ARE IN GENERAL AGREEMENT IN TRANSITIONING TO A MORE
MERIDIONAL FLOW PATTERN THROUGH THE WEEK. PRIOR TO THE RIDGE
BUILDING TO THE POINT OF CUTTING OFF ENERGY FROM IMPACTING IL...IT
APPEARS THAT A SERIES OF WEAK WAVES MAY EFFECT THE AREA PERIODICALLY
INTO SATURDAY. WITH DAYTIME TEMPS IN THE 70S...THE INSTABILITY WILL
BE WELL OVER 1000J/KG AT TIMES. HOWEVER...SHEAR IS VERY LIMITED AND
DEEP MOISTURE IS LACKING. SCATTERED THUNDERSTORMS MAY DEVELOP WITH
SOME LOCALLY STRONG CELLS...BUT WIDESPREAD CONVECTION IS UNLIKELY.
WILL GO WITH CHC POPS THROUGH MUCH OF THE PERIOD.
LONG TERM...SATURDAY NIGHT THROUGH TUESDAY
WITH HEIGHTS BUILDING FROM SATURDAY NIGHT THROUGH TUESDAY...
ATMOSPHERE SHOULD CONTINUE TO DRY. HAVE GONE LOWER ON SKY COVER AND
REMOVED POPS FOR THE PERIOD. GFS IS STRONGEST OF THE 12Z SUITE WITH
STRENGTH OF RIDGE...5850M+ AT 500MB BY 00Z WED...AND RESULTANT
WARMING. GENERALLY FAVOR ITS SOLUTION GIVEN THE WARM TREND OF LATE.
THE ECMWF DOES HAVE SOME PRECIP MAINLY DURING THE AFTERNOON AND
EVENING AS THE RIDGE IS WEAKER BY ALMOST 100M IN THAT SOLUTION AND
ALLOWS MORE ENERGY TO IMPACT IL...BUT IT IS HARD TO SEE WHERE THE
DEEP MOISTURE CAN ADVECT IN FROM AND WILL GO DRY.
MODELS ARE IN GOOD AGREEMENT IN KEEPING 850MB TEMPS 10C OR HIGHER
THROUGH FORECAST PERIOD. WARMER GFS EVEN APPROACHES 15C BY EARLY
NEXT WEEK. WILL KEEP TEMPS 15-25 DEGREES ABOVE NORMAL WITH HIGHS
CONSISTENTLY IN THE 70S AND POSSIBLY A FEW 80S.
BARKER
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
416 AM EDT WED MAR 14 2012
.SYNOPSIS...
ISSUED AT 413 AM EDT WED MAR 14 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG OVER MN
BTWN CLOSED LO SHIFTING SEWD THRU QUEBEC AND A MEAN TROF ALONG THE W
COAST. WITH CWA UNDER THE CONFLUENT NW FLOW ALF/12HR H3 RISES AOA
100M...ASSOCIATED SFC HI PRES RDG IS BRINGING TRANQUIL WX/MOCLR
SKIES. AIRMASS IN PLACE IS ALSO RELATIVELY DRY PER LOCAL 00Z
RAOBS...SO SFC TEMPS HAVE FALLEN AOB 32 AT MANY INTERIOR COLD
LOCATIONS WITH THE MOCLR SKIES/LGT WINDS. BUT A MUCH WARMER AIRMASS
IS EVIDENT JUST TO THE W UNDER THE STRONG SLY FLOW BTWN THE SFC HI
PRES RDG OVER THE GRT LKS AND LOWER PRES IN THE HI PLAINS ASSOCIATED
WITH STRONG SHRTWV LIFTING NEWD THRU SW CAN TO THE E OF TROF ALONG
THE W COAST. 00Z H85 TEMPS REACHED AOA 15C ALL THE WAY UP TO GLASGOW
MONTANA AND BISMARCK...AND SFC HI TEMPS WERE UP TO 75 IN EASTERN
MONTANA AND WRN NDAKOTA UNDER THIS WARM SURGE. PIERRE SDAKOTA
REPORTED A MAX TEMP OF 82. THE AIRMASS IN THE CENTRAL AND NRN PLAINS
IS VERY DRY PER 00Z PWAT OF 0.14/0.17 AT RAPID CITY SDAKOTA/NORTH
PLATTE NEBRASKA. BUT A SURGE OF HIER SFC DWPTS IS NOTED MOVING N FM
THE SRN PLAINS...WITH SFC DWPTS AT 03Z UP TO 55 AT KANSAS CITY UNDER
THE STRONG S WINDS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 413 AM EDT WED MAR 14 2012
TODAY...AS SFC HI PRES SHIFTS INTO THE MID ATLANTIC STATES AND SFC
TROF/COLD FNT ASSOCIATED WITH DEEP SHRTWV LIFTING FM SW CAN TOWARD
HUDSON BAY MOVES INTO WRN LK SUP IN THE AFTN...STRONGER SSW FLOW
UNDER SHARPER PRES GRADIENT BTWN THESE FEATURES IS FCST TO LIFT H85
TEMPS UP TO 12-14C THIS AFTN. ALTHOUGH SOME OF THE MORE COPIOUS LLVL
MSTR IS FCST TO PUSH IN THIS AFTN...THE ARRIVAL OF THIS MSTR WL
COINCIDE WITH PEAK HEATING TIME...SO THERE SHOULD NOT BE MUCH IN THE
WAY OF CLD COVER AHEAD OF THE APRCHG TROF/FNT. WITH PLENTY OF
SUNSHINE AND MIXING TO H85 ON NAM FCST SDNGS...EXPECT TEMPS OVER THE
INTERIOR W TO REACH 70 TO 75. AREAS OVER THE E HALF WL BE COOLER
DOWNWIND OF THE MODIFYING INFLUENCE OF LK MI. DAILY RECORD HI TEMPS
OF 62 AT IWD...56 AT CMX...67 AT IMT...AND 60 AT THE MQT NWS OFFICE
ARE IN SERIOUS JEOPARDY. THE ARRIVAL OF THE SFC COLD FNT LATE OVER
THE W WL BRING SOME MORE CLDS/COOLER TEMPS TOWARD EVNG...BUT THE
OVERALL AIRMASS WL BE TOO DRY WITH PERSISTENT INVRN H75-8 TO SUPPORT
ANY PCPN CONSIDERING THE ABSENCE OF H5 FALLS WITH PASSAGE OF THE
MAIN DYNAMICS WELL TO THE N CLOSER TO SHRTWV TRACK. SO IGNORED THE
LGT QPF GENERATED BY THE 00Z GFS.
TNGT...AS MAIN SHRTWV TO THE N MOVES ACRS HUDSON BAY...SFC COOL FNT
WL DRIFT W-E ACRS THE CWA AND INTO NRN LWR MI BY 12Z THU. MODELS...
ESPECIALLY THE GFS...GENERATE SPOTTY QPF OVER MAINLY THE SE ZNS IN
THE EVNG JUST AHEAD OF THE TROF. SINCE THE INCOMING LLVL MSTR DOES
GET DEEPER AND UP TO H85-8 PER NAM FCST SDNGS...OPTED TO MAINTAIN
SCHC POPS FM ROUGHLY MNM TO ERY THRU ABOUT 06Z...WHEN DRYING WITH A
WSHFT TO THE W BEHIND THE FROPA WL ADVECT DRIER AIR EWD. OPTED TO
ADD MENTION OF ELEVATED TS GIVEN STEEP MID LVL LAPSE RATES ABV LLVL
MOISTENING. PERSISTENCE OF INVRN H8-75 IN ABSENCE OF SGNFT MID LVL
DYNAMICS WL BE THE LIMITING FACTOR FOR ANY SHRA/TS. ALTHOUGH THERE
WL BE DRYING ALF AS HI PRES MOVES ACRS NW LK SUP UNDER WSW FLOW
ALF... VARIOUS GUIDANCE SHOWS MORE LLVL MSTR PERSISTING EVEN AFT THE
FROPA. SO TENDED TO MAINTAIN MORE CLD COVER THRU THE NGT WHERE THE
NW VEERING N WIND WL UPSLOPE.
THU...WITH PERSISTENT WSW FLOW ALF BTWN MEAN UPR RDG OVER THE SE
CONUS AND TROFFING OUT W...SFC HI PRES IS PROGGED TO DRIFT INTO
QUEBEC...LEAVING A SFC RDG OVER THE UPR LKS. ALTHOUGH DRY AIR IN THE
MID LVLS WL RESULT IN A PCPN-FREE DAY...VARIOUS MODELS CONTINUE TO
SHOW LINGERING LLVL MSTR WITH SHALLOW COOL AIR INFUSION MAINTAINING
FAIRLY SHARP SFC-BASED INVRN. TRICKY TEMPS FCST FOR THU CONSIDERING
DIFFERENCES IN LLVL MSTR SHOWN BY THE VARIOUS MODELS AND POTENTIAL
FOR MORE PERSISTENT ST/SC. TENDED COOLEST NEAR THE LK SHORES WITH
LGT NE FLOW TENDING TO VEER E AND GREATER HEATING INLAND SUPPORTING
LK BREEZE COOLING. ALTHOUGH TEMPS WL BE CONSIDERABLY COOLER THAN
TDAY AND PROBABLY CLOSER TO THE LOWER NAM GUIDANCE GIVEN RATHER HI
STABILITY SHOWN ON FCST SDNGS/POTENTIAL LO CLDS...READINGS WL STILL
BE WELL ABV NORMAL FOR THE IDES OF MARCH.
THU NGT...MAJORITY OF MODELS SHOW WEAK SHRTWV MOVING IN FM THE
WSW...CAUSING LGT LLVL FLOW TO VEER MORE TO THE S. WHILE THIS WSHFT
MIGHT LIMIT UPSLOPE CLD OFF LK SUP...CONCERN SOME ST/SC COULD DRIFT
IN FM LK MI/BAY OF GREEN BAY. SINCE THE FLOW WL BE LGT AND THE MID
LVLS DRY...ALSO MAINTAINED PATCHY FOG IN THE FCST OVER THE E
DOWNWIND OF LK MI.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 413 AM EDT WED MAR 14 2012
WEAK DISTURBANCE THAT MOVED JUST N OF LK SUPERIOR ON THURS NIGHT
WILL SHIFT E OF THE AREA ON FRI...ALLOWING THE UPPER RIDGE TO
RE-ESTABLISH ITSELF OVER THE UPPER GREAT LAKES ON FRI AND FRI NIGHT.
FRI... MOSTLY SUNNY DUE TO DRY AIR AND SUBSIDENCE UNDER THE UPPER
RIDGE AND EXITING SFC HIGH. MIX TO H900 WOULD YIELD TEMPS IN THE
LOW-MID 60S AWAY FROM LK MI INFLUENCES. MODEL CONSENSUS IS A LIGHT
SE BREEZE...WHICH COULD PRODUCE ONSHORE FLOW OVER THE KEWEENAW
PENINSULA AND LEADS TO THE POTENTIAL FOR LIGHT LK BREEZES OVER THE W
AND NCTNRL. LATEST NAM HAS TRENDED TOWARDS STRONGER WINDS AS IT
TRIES TO MIX INTO THE STRONGER WINDS ALOFT...WHICH WOULD LIMIT LK
BREEZE POTENTIAL.
FRI NIGHT...SRLY FLOW INCREASES AS THE AREA IS BETWEEN SFC HIGH OVER
SW QUEBEC AND LOW NEAR LK WINNIPEG. THIS TRIES TO PULL ADDITIONAL
LLVL MOISTURE OVER THE AREA. GFS IS THE MOST AGGRESSIVE WITH
THIS...WHICH ATTEMPTS TO SOCK THE AREA IN WITH LOW CLOUDS BELOW THE
INVERSION AROUND H850-800. NAM A LITTLE SLOWER...BUT EVENTUALLY
SHOWS A SIMILAR SITUATION. NOT ENTIRELY CONFIDENT THIS WILL
OCCUR...BUT WILL TREND TOWARDS A MORE CLOUDY SOLN. IF THIS LLVL
MOISTURE DOES OCCUR...EXPECT FOG TO DEVELOP OVER LK MI AND MOVE INTO
THE ERN CWA. HAVE ADDED A MENTION OF PATCHY FOG NEAR/OVER LK MI AND
ADDED IT OVER NRN LK SUPERIOR OVERNIGHT.
MODELS STILL OUTPUTTING PCPN...LIKELY LIGHT DRIZZLE...IN ONLY A 1 TO
MAYBE 2KFT AREA OF MOISTURE/CLOUDS NEAR THE SFC. REALLY NOT BUYING
THAT SITUATION...SO WILL CAP POPS JUST BELOW SLIGHT CHANCES.
DAYS 4 THROUGH 7 /SATURDAY THROUGH TUESDAY/...
ANOMALOUS H500 HEIGHTS...AROUND 2-3 STD DEV ABOVE NORMAL FOR
MID-LATE MARCH WILL REMAIN OVER THE AREA FOR THE EXTENDED PERIOD.
OTHER THAN A COUPLE WEAK IMPULSES MOVING THROUGH THE SWRLY FLOW
ALOFT...EXPECT A FAIRLY WARM/DRY PERIOD TO CONTINUE INTO THE FIRST
HALF OF NEXT WEEK.
BEST OPPORTUNITY FOR A WEAK WAVE LOOKS TO BE ON SAT AFTN INTO SUN
MORN. MODELS SHOWING SOME MOISTURE TO WORK WITH ABOVE H850 AND
ELEVATED INSTABILITY WOULD SUPPORT THE POTENTIAL FOR THUNDER IF ANY
SHOWERS DEVELOP WITH THE WEAK SHORTWAVE. OTHERWISE...DON/T SEE ANY
SIGNIFICANT WAVES OR FORCING AFFECTING THE AREA.
MAIN FOCUS FOR THE EXTENDED IS LLVL MOISTURE AND TEMPS. 00Z GFS
CONTINUES TO SHOW ABUNDANT LLVL MOISTURE BELOW THE H850 INVERSION
THROUGH THE EXTENDED PERIOD. 12Z ECMWF...EVEN WITH THE LIMITED LOWER
LEVELS AVAILABLE DOESN/T SHOW THAT EXTENT OF LLVL MOISTURE. GEM DOES
HINT AT IT AND WONDERING IF IT WILL BE DIURNALLY DRIVEN WITH MORE
CLOUDS AT NIGHT AND THEN ATTEMPT TO MIX OUT DURING THE DAY. IT IS
ONE OF THOSE TOUGH SITUATIONS...DUE TO NO SIGNIFICANT CHANGES AND
THE DECENT CAP...WHICH COULD LEAD TO LOW CLOUDS BECOMING TRAPPED
BELOW THE INVERSION AND STRUGGLING TO BREAK OUT. DON/T HAVE ENOUGH
CONFIDENCE ONE WAY OR ANOTHER TO BUCK THE MODEL CONSENSUS AND WILL
LEAVE IT AS IS. MODELS TRYING TO DROP A HUNDREDTH OF QPF OVER THE
GREAT LKS...WHICH IS LARGELY A FUNCTION OF THE LLVL MOISTURE AND
RESULTANT FOG. ADDED PATCHY FOG NEAR LK MI FOR SAT/SUN AND ALSO LK
SUPERIOR JUST OFF SHORE FROM UPPER MI WITH THE SSE FLOW. MAY NEED TO
EXTEND IT THROUGH THE EXTENDED PERIOD IF LLVL MOISTURE PANS
OUT...WHICH WOULD PROBABLY PRODUCE SOME DENSE PERIODS.
TEMPS REMAIN WELL ABOVE NORMAL THROUGH THE FIRST PART OF NEXT
WEEK...WITH HIGHS IN THE 60S AWAY FROM THE SOUTHERLY WINDS OF LK
MI. LOW CLOUDS/FOG COULD CAUSE ISSUES WITH THESE TEMPS AND ONLY
CHANGES MADE TO THE MODEL CONSENSUS WAS TO WARM UP DOWNSLOPE AREAS
NEAR LK SUPERIOR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 110 AM EDT WED MAR 14 2012
DRY AIRMASS WILL PERSIST OVER THE AREA AS VFR CONDITIONS SHOULD
PREVAIL AT KIWD/KCMX/KSAW THRU THE FCST PERIOD. AS HIGH PRES RIDGE
SHIFTS E OF THE AREA OVERNIGHT...WINDS WILL INCREASE ABOVE NOCTURNAL
INVERSION...RESULTING IN LLWS AT KIWD AND KCMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 413 AM EDT WED MAR 14 2012
EXPECT WINDS TO BE GENERALLY UNDER 25 KTS INTO THIS WEEKEND AS A
RELATIVELY WEAK PRES GRADIENT DOMINATES. ALTHOUGH A SHARPER PRES
GRADIENT/STRONGER S FLOW WILL DEVELOP OVER THE WEEKEND...THE
UNSEASONABLY WARM AIR OVER THE UPPER GREAT LAKES WILL ALSO RESULT IN
PERSISTENT MARINE LAYER/STRONG STABILITY OVER THE LAKE...HELPING TO
KEEP SURFACE WINDS ON THE LIGHTER SIDE. AT SOME POINT...FOG MAY
BECOME AN ISSUE...BUT EXPECTED DRY WEATHER THRU THE WEEKEND WILL
LIMIT THIS POTENTIAL.
&&
.HYDROLOGY...
ISSUED AT 413 AM EDT WED MAR 14 2012
WARM TEMPERATURES OVER THE LAST SEVERAL DAYS...ALONG WITH RAIN OF
0.10 TO MORE THAN 0.5 INCH ON MON HAS LED TO INCREASED SNOWMELT/
RUNOFF. THIS RUNOFF HAS PRODUCED SOME RISE IN LEVELS OF RIVERS IN
UPR MI OVER THE LAST COUPLE OF DAYS. TEMPS HAVE FALLEN BLO 32 AT
MANY SPOTS OVER THE CWA EARLY THIS MRNG...BRINGING A TEMPORARY
RESPITE TO THE STEADY MELTING.
ABOVE NORMAL TEMPERATURES INTO NEXT WEEK WILL CONTINUE TO MELT THE
SNOW PACK AND LEAD TO FURTHER INCREASES IN RIVER AND STREAM LEVELS.
DESPITE THE BREAK EARLY THIS MRNG...A PERIOD OF RAPID MELTING WILL
OCCUR TODAY...AS TEMPERATURES RISE AOA 70 DEGREES OVER THE WEST AND
DEWPOINTS RISE INTO THE 40S LATER IN THE DAY. ALTHOUGH A COOLER
AIRMASS WILL ARRIVE ON THU...EXPECT SOME OF THE RIVERS ACROSS THE
AREA TO EXCEED THEIR BANKS BY THE END OF THIS WEEK. PERSONS LIVING
NEAR RIVERS AND STREAMS SHOULD MONITOR THE LATEST RIVER CONDITIONS
AND USE CAUTION IF WALKING ALONG RIVER BANKS...ESPECIALLY THE
CHOCOLAY RIVER...TRAP ROCK RIVER...AND THE STURGEON RIVER IN WESTERN
UPPER MICHIGAN.
THERE WAS AN APPARENT ICE JAM ON THE ONTONAGON RIVER NEAR ROCKLAND
MON EVENING. THIS CAUSED THE RIVER LEVELS TO RISE 4FT BEFORE IT
BROKE FREE. WILL NEED TO MONITOR CONDITIONS ALONG THE ONTONAGON RIVER
OVER THE NEXT DAY OR TWO...AS THE NUMEROUS BENDS COULD CAUSE THE ICE
TO FORM ANOTHER JAM. IN ADDITION...ICE WAS REPORTED ON THE FORD RIVER
AT HYDE AND THE MOUTH AT LK MI. DEPENDING ON THE BREAKUP OF THE
ICE...THERE IS A POTENTIAL FOR ICE JAMS THIS WEEK. &&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...SRF
AVIATION...VOSS
MARINE...KC
HYDROLOGY...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
357 AM EDT WED MAR 14 2012
.SYNOPSIS...
ISSUED AT 355 AM EDT WED MAR 14 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG OVER MN
BTWN CLOSED LO SHIFTING SEWD THRU QUEBEC AND A MEAN TROF ALONG THE W
COAST. WITH CWA UNDER THE CONFLUENT NW FLOW ALF/12HR H3 RISES AOA
100M...ASSOCIATED SFC HI PRES RDG IS BRINGING TRANQUIL WX/MOCLR
SKIES. AIRMASS IN PLACE IS ALSO RELATIVELY DRY PER LOCAL 00Z
RAOBS...SO SFC TEMPS HAVE FALLEN AOB 32 AT MANY INTERIOR COLD
LOCATIONS WITH THE MOCLR SKIES/LGT WINDS. BUT A MUCH WARMER AIRMASS
IS EVIDENT JUST TO THE W UNDER THE STRONG SLY FLOW BTWN THE SFC HI
PRES RDG OVER THE GRT LKS AND LOWER PRES IN THE HI PLAINS ASSOCIATED
WITH STRONG SHRTWV LIFTING NEWD THRU SW CAN TO THE E OF TROF ALONG
THE W COAST. 00Z H85 TEMPS REACHED AOA 15C ALL THE WAY UP TO GLASGOW
MONTANA AND BISMARCK...AND SFC HI TEMPS WERE UP TO 75 IN EASTERN
MONTANA AND WRN NDAKOTA UNDER THIS WARM SURGE. PIERRE SDAKOTA
REPORTED A MAX TEMP OF 82. THE AIRMASS IN THE CENTRAL AND NRN PLAINS
IS VERY DRY PER 00Z PWAT OF 0.14/0.17 AT RAPID CITY SDAKOTA/NORTH
PLATTE NEBRASKA. BUT A SURGE OF HIER SFC DWPTS IS NOTED MOVING N FM
THE SRN PLAINS...WITH SFC DWPTS AT 03Z UP TO 55 AT KANSAS CITY UNDER
THE STRONG S WINDS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT) ISSUED AT 355 AM EDT
WED MAR 14 2012
TODAY...AS SFC HI PRES SHIFTS INTO THE MID ATLANTIC STATES AND SFC
TROF/COLD FNT ASSOCIATED WITH DEEP SHRTWV LIFTING FM SW CAN TOWARD
HUDSON BAY MOVES INTO WRN LK SUP IN THE AFTN...STRONGER SSW FLOW
UNDER SHARPER PRES GRADIENT BTWN THESE FEATURES IS FCST TO LIFT H85
TEMPS UP TO 12-14C THIS AFTN. ALTHOUGH SOME OF THE MORE COPIOUS LLVL
MSTR IS FCST TO PUSH IN THIS AFTN...THE ARRIVAL OF THIS MSTR WL
COINCIDE WITH PEAK HEATING TIME...SO THERE SHOULD NOT BE MUCH IN THE
WAY OF CLD COVER AHEAD OF THE APRCHG TROF/FNT. WITH PLENTY OF
SUNSHINE AND MIXING TO H85 ON NAM FCST SDNGS...EXPECT TEMPS OVER THE
INTERIOR W TO REACH 70 TO 75. AREAS OVER THE E HALF WL BE COOLER
DOWNWIND OF THE MODIFYING INFLUENCE OF LK MI. DAILY RECORD HI TEMPS
OF 62 AT IWD...56 AT CMX...67 AT IMT...AND 60 AT THE MQT NWS OFFICE
ARE IN SERIOUS JEOPARDY. THE ARRIVAL OF THE SFC COLD FNT LATE OVER
THE W WL BRING SOME MORE CLDS/COOLER TEMPS TOWARD EVNG...BUT THE
OVERALL AIRMASS WL BE TOO DRY WITH PERSISTENT INVRN H75-8 TO SUPPORT
ANY PCPN CONSIDERING THE ABSENCE OF H5 FALLS WITH PASSAGE OF THE
MAIN DYNAMICS WELL TO THE N CLOSER TO SHRTWV TRACK. SO IGNORED THE
LGT QPF GENERATED BY THE 00Z GFS.
TNGT...AS MAIN SHRTWV TO THE N MOVES ACRS HUDSON BAY...SFC COOL FNT
WL DRIFT W-E ACRS THE CWA AND INTO NRN LWR MI BY 12Z THU. MODELS...
ESPECIALLY THE GFS...GENERATE SPOTTY QPF OVER MAINLY THE SE ZNS IN
THE EVNG JUST AHEAD OF THE TROF. SINCE THE INCOMING LLVL MSTR DOES
GET DEEPER AND UP TO H85-8 PER NAM FCST SDNGS...OPTED TO MAINTAIN
SCHC POPS FM ROUGHLY MNM TO ERY THRU ABOUT 06Z...WHEN DRYING WITH A
WSHFT TO THE W BEHIND THE FROPA WL ADVECT DRIER AIR EWD. OPTED TO
ADD MENTION OF ELEVATED TS GIVEN STEEP MID LVL LAPSE RATES ABV LLVL
MOISTENING. PERSISTENCE OF INVRN H8-75 IN ABSENCE OF SGNFT MID LVL
DYNAMICS WL BE THE LIMITING FACTOR FOR ANY SHRA/TS. ALTHOUGH THERE
WL BE DRYING ALF AS HI PRES MOVES ACRS NW LK SUP UNDER WSW FLOW
ALF... VARIOUS GUIDANCE SHOWS MORE LLVL MSTR PERSISTING EVEN AFT THE
FROPA. SO TENDED TO MAINTAIN MORE CLD COVER THRU THE NGT WHERE THE
NW VEERING N WIND WL UPSLOPE.
THU...WITH PERSISTENT WSW FLOW ALF BTWN MEAN UPR RDG OVER THE SE
CONUS AND TROFFING OUT W...SFC HI PRES IS PROGGED TO DRIFT INTO
QUEBEC...LEAVING A SFC RDG OVER THE UPR LKS. ALTHOUGH DRY AIR IN THE
MID LVLS WL RESULT IN A PCPN-FREE DAY...VARIOUS MODELS CONTINUE TO
SHOW LINGERING LLVL MSTR WITH SHALLOW COOL AIR INFUSION MAINTAINING
FAIRLY SHARP SFC-BASED INVRN. TRICKY TEMPS FCST FOR THU CONSIDERING
DIFFERENCES IN LLVL MSTR SHOWN BY THE VARIOUS MODELS AND POTENTIAL
FOR MORE PERSISTENT ST/SC. TENDED COOLEST NEAR THE LK SHORES WITH
LGT NE FLOW TENDING TO VEER E AND GREATER HEATING INLAND SUPPORTING
LK BREEZE COOLING. ALTHOUGH TEMPS WL BE CONSIDERABLY COOLER THAN
TDAY AND PROBABLY CLOSER TO THE LOWER NAM GUIDANCE GIVEN RATHER HI
STABILITY SHOWN ON FCST SDNGS/POTENTIAL LO CLDS...READINGS WL STILL
BE WELL ABV NORMAL FOR THE IDES OF MARCH.
THU NGT...MAJORITY OF MODELS SHOW WEAK SHRTWV MOVING IN FM THE
WSW...CAUSING LGT LLVL FLOW TO VEER MORE TO THE S. WHILE THIS WSHFT
MIGHT LIMIT UPSLOPE CLD OFF LK SUP...CONCERN SOME ST/SC COULD DRIFT
IN FM LK MI/BAY OF GREEN BAY. SINCE THE FLOW WL BE LGT AND THE MID
LVLS DRY...ALSO MAINTAINED PATCHY FOG IN THE FCST OVER THE E
DOWNWIND OF LK MI.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 355 AM EDT WED MAR 14 2012
WEAK DISTURBANCE THAT MOVED JUST N OF LK SUPERIOR ON THURS NIGHT
WILL SHIFT E OF THE AREA ON FRI...ALLOWING THE UPPER RIDGE TO
RE-ESTABLISH ITSELF OVER THE UPPER GREAT LAKES ON FRI AND FRI NIGHT.
FRI... MOSTLY SUNNY DUE TO DRY AIR AND SUBSIDENCE UNDER THE UPPER
RIDGE AND EXITING SFC HIGH. MIX TO H900 WOULD YIELD TEMPS IN THE
LOW-MID 60S AWAY FROM LK MI INFLUENCES. MODEL CONSENSUS IS A LIGHT
SE BREEZE...WHICH COULD PRODUCE ONSHORE FLOW OVER THE KEWEENAW
PENINSULA AND LEADS TO THE POTENTIAL FOR LIGHT LK BREEZES OVER THE W
AND NCTNRL. LATEST NAM HAS TRENDED TOWARDS STRONGER WINDS AS IT
TRIES TO MIX INTO THE STRONGER WINDS ALOFT...WHICH WOULD LIMIT LK
BREEZE POTENTIAL.
FRI NIGHT...SRLY FLOW INCREASES AS THE AREA IS BETWEEN SFC HIGH OVER
SW QUEBEC AND LOW NEAR LK WINNIPEG. THIS TRIES TO PULL ADDITIONAL
LLVL MOISTURE OVER THE AREA. GFS IS THE MOST AGGRESSIVE WITH
THIS...WHICH ATTEMPTS TO SOCK THE AREA IN WITH LOW CLOUDS BELOW THE
INVERSION AROUND H850-800. NAM A LITTLE SLOWER...BUT EVENTUALLY
SHOWS A SIMILAR SITUATION. NOT ENTIRELY CONFIDENT THIS WILL
OCCUR...BUT WILL TREND TOWARDS A MORE CLOUDY SOLN. IF THIS LLVL
MOISTURE DOES OCCUR...EXPECT FOG TO DEVELOP OVER LK MI AND MOVE INTO
THE ERN CWA. HAVE ADDED A MENTION OF PATCHY FOG NEAR/OVER LK MI AND
ADDED IT OVER NRN LK SUPERIOR OVERNIGHT.
MODELS STILL OUTPUTTING PCPN...LIKELY LIGHT DRIZZLE...IN ONLY A 1 TO
MAYBE 2KFT AREA OF MOISTURE/CLOUDS NEAR THE SFC. REALLY NOT BUYING
THAT SITUATION...SO WILL CAP POPS JUST BELOW SLIGHT CHANCES.
DAYS 4 THROUGH 7 /SATURDAY THROUGH TUESDAY/...
ANOMALOUS H500 HEIGHTS...AROUND 2-3 STD DEV ABOVE NORMAL FOR
MID-LATE MARCH WILL REMAIN OVER THE AREA FOR THE EXTENDED PERIOD.
OTHER THAN A COUPLE WEAK IMPULSES MOVING THROUGH THE SWRLY FLOW
ALOFT...EXPECT A FAIRLY WARM/DRY PERIOD TO CONTINUE INTO THE FIRST
HALF OF NEXT WEEK.
BEST OPPORTUNITY FOR A WEAK WAVE LOOKS TO BE ON SAT AFTN INTO SUN
MORN. MODELS SHOWING SOME MOISTURE TO WORK WITH ABOVE H850 AND
ELEVATED INSTABILITY WOULD SUPPORT THE POTENTIAL FOR THUNDER IF ANY
SHOWERS DEVELOP WITH THE WEAK SHORTWAVE. OTHERWISE...DON/T SEE ANY
SIGNIFICANT WAVES OR FORCING AFFECTING THE AREA.
MAIN FOCUS FOR THE EXTENDED IS LLVL MOISTURE AND TEMPS. 00Z GFS
CONTINUES TO SHOW ABUNDANT LLVL MOISTURE BELOW THE H850 INVERSION
THROUGH THE EXTENDED PERIOD. 12Z ECMWF...EVEN WITH THE LIMITED LOWER
LEVELS AVAILABLE DOESN/T SHOW THAT EXTENT OF LLVL MOISTURE. GEM DOES
HINT AT IT AND WONDERING IF IT WILL BE DIURNALLY DRIVEN WITH MORE
CLOUDS AT NIGHT AND THEN ATTEMPT TO MIX OUT DURING THE DAY. IT IS
ONE OF THOSE TOUGH SITUATIONS...DUE TO NO SIGNIFICANT CHANGES AND
THE DECENT CAP...WHICH COULD LEAD TO LOW CLOUDS BECOMING TRAPPED
BELOW THE INVERSION AND STRUGGLING TO BREAK OUT. DON/T HAVE ENOUGH
CONFIDENCE ONE WAY OR ANOTHER TO BUCK THE MODEL CONSENSUS AND WILL
LEAVE IT AS IS. MODELS TRYING TO DROP A HUNDREDTH OF QPF OVER THE
GREAT LKS...WHICH IS LARGELY A FUNCTION OF THE LLVL MOISTURE AND
RESULTANT FOG. ADDED PATCHY FOG NEAR LK MI FOR SAT/SUN AND ALSO LK
SUPERIOR JUST OFF SHORE FROM UPPER MI WITH THE SSE FLOW. MAY NEED TO
EXTEND IT THROUGH THE EXTENDED PERIOD IF LLVL MOISTURE PANS
OUT...WHICH WOULD PROBABLY PRODUCE SOME DENSE PERIODS.
TEMPS REMAIN WELL ABOVE NORMAL THROUGH THE FIRST PART OF NEXT
WEEK...WITH HIGHS IN THE 60S AWAY FROM THE SOUTHERLY WINDS OF LK
MI. LOW CLOUDS/FOG COULD CAUSE ISSUES WITH THESE TEMPS AND ONLY
CHANGES MADE TO THE MODEL CONSENSUS WAS TO WARM UP DOWNSLOPE AREAS
NEAR LK SUPERIOR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 110 AM EDT WED MAR 14 2012
DRY AIRMASS WILL PERSIST OVER THE AREA AS VFR CONDITIONS SHOULD
PREVAIL AT KIWD/KCMX/KSAW THRU THE FCST PERIOD. AS HIGH PRES RIDGE
SHIFTS E OF THE AREA OVERNIGHT...WINDS WILL INCREASE ABOVE NOCTURNAL
INVERSION...RESULTING IN LLWS AT KIWD AND KCMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 AM EDT WED MAR 14 2012
EXPECT WINDS TO BE GENERALLY UNDER 25 KTS INTO THIS WEEKEND AS A
RELATIVELY WEAK PRES GRADIENT DOMINATES. ALTHOUGH A SHARPER PRES
GRADIENT/STRONGER S FLOW WILL DEVELOP OVER THE WEEKEND...THE
UNSEASONABLY WARM AIR OVER THE UPPER GREAT LAKES WILL ALSO RESULT IN
PERSISTENT MARINE LAYER/STRONG STABILITY OVER THE LAKE...HELPING TO
KEEP SURFACE WINDS ON THE LIGHTER SIDE. AT SOME POINT...FOG MAY
BECOME AN ISSUE...BUT EXPECTED DRY WEATHER THRU THE WEEKEND WILL
LIMIT THIS POTENTIAL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...SRF
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
359 AM CDT WED MAR 14 2012
.DISCUSSION...
FOCUS CENTERS AROUND RECORD/NEAR RECORD TEMPS AND CHANCES FOR
TSTMS NEXT FEW DAYS.
WEAK UPPER LEVEL RIDGE HAS MOVED WELL EAST OF THE REGION LEAVING
CENTRAL PLAINS IN WEAK SOUTHWESTERLY FLOW ALOFT FOR NEXT FEW DAYS.
SEVERAL WEAK SHORTWAVES ARE EMBEDDED WITHIN THIS SOUTHWEST FLOW
AND WILL COMPLICATE THE FORECAST INTO THE WEEKEND. MODEL AGREEMENT
ON STRENGTH OF THESE SHORTWAVES IS POOR...LEADING TO LOW
FORECASTER CONFIDENCE ON TSTM CHANCES INTO THE WEEKEND.
TEMPERATURES REMAIN QUITE WARM THIS MORNING AND WILL BE CLOSE TO
RECORD MAX MINS. STRONG MOIST ADVECTION CONTINUES WITH UPSTREAM
DEWPOINTS IN THE UPPER 50S. PATCHY STRATUS IS BEGINNING TO DEVELOP
ACROSS SRN KS AND SO WILL HAVE TO KEEP A CLOSE EYE ON HOW
WIDESPREAD THIS BECOMES THROUGH THE MORNING HOURS. 06Z NAM AND
LATEST HRRR ARE TOO QUICK ON SPREADING THIS STRATUS INTO OUR SERN
COUNTIES SO DO HAVE RESERVATIONS ABOUT ADDING CLOUDS TO THE
SOUTHEAST. SURFACE COLD FRONT CURRENTLY EXTENDS ACROSS CNTRL ND
AND INTO NWRN SD AND WILL QUICKLY PUSH SEWD THROUGH THE MORNING
HOURS AND ENTER INTO THE NWRN CWA BY LATE MORNING. WE SHOULD BE
ABLE TO MIX OUT AHEAD OF THE BOUNDARY WITH THE FRONT COMING THRU A
MAJORITY OF THE CWA BY PEAK HEATING. HAVE FOLLOWED MORE CLOSELY TO
PREVIOUS FORECAST HIGHS TODAY RATHER THAN JUMP ONTO NEW MET
GUIDANCE WHICH IS ABOUT 10 DEGREES COOLER. WE ARE STILL
FORECASTING NEAR RECORD HIGHS AT LNK AND OMA. DID REMOVE CHANCE OF
TSTMS TONIGHT AS FORCING IS MINIMAL AND INSTABILITY AXIS IS FAR TO
OUR SOUTH. SFC FRONT WASHES OUT OVER THE FORECAST AREA THIS
EVENING.
SOUTHERLY LOW LEVEL FLOW RETURNS ON THURSDAY WITH SFC DEWPOINTS
RETURNING INTO THE UPPER 50S TO NEAR 60 IN OUR SOUTH BY THURSDAY
AFTERNOON. DRY LINE/SFC TROF IS FORECAST TO REMAIN JUST TO OUR WEST
AND AS A WEAK UPPER LEVEL SHORTWAVE APPROACHES THE REGION...TSTMS
COULD POSSIBLY DEVELOP BY LATE AFTERNOON. SWODY2 HAS LARGE AREA OF
SLIGHT RISK OVER THE CWA. WL CONCENTRATE TSTM CHANCES MAINLY IN THE
SOUTH WHERE RICH THETA-E AIR RESIDES. VEERED LOW LEVEL JET AROUND
30KTS WL AID IN LLVL CONVERGENCE INTO THE EVENING HOURS. CONFIDENCE
IS LOW ON THE TSTM CHANCES SO THEREFORE HAVE ONLY GONE WITH A SLIGHT
CHANCE POP.
SOUTHWESTERLY FLOW ALOFT CONTINUES INTO THE WEEKEND WITH RICH
BOUNDARY LAYER MOISTURE REMAINING IN PLACE. SHORTWAVE IS
FORECAST TO PASS OVER THE REGION WITH LITTLE CONFIDENCE ONCE
AGAIN ON STRENGTH. WL NOT GET TOO CARRIED AWAY ADDING TSTMS OVER
THE ENTIRE FORECAST AREA JUST YET BUT DO HAVE LOW POPS IN THE SOUTH
ON FRIDAY NIGHT AS NOSE OF VEERED 50KT LOW LEVEL JET CREEPS INTO
SERN NEB WHERE INSTABILITY REMAINS MODERATE.
IN THE EXTENDED...LARGE WESTERN TROF AXIS IS FORECAST TO SLOWLY
PROGRESS INTO THE FOUR CORNERS REGION BY MONDAY AND BECOME SLIGHTLY
NEGATIVELY TILTED BY TUESDAY AS IT MOVES TOWARD THE CNTRL PLAINS.
CHANCE POPS CONTINUE FOR MUCH OF NEXT WEEK AHEAD OF THIS LARGE
TROUGH.
KERN
&&
.AVIATION...
06Z TAFS FOR KOFK...KLNK AND KOMA.
MAINLY VFR CONDITIONS WILL CONTINUE THROUGH WEDNESDAY EVENING.
SOME LOW LEVEL WIND SHEAR IS LIKELY THROUGH 11Z AT KLNK AND KOMA
AS LOW LEVEL JET KICKS UP TO OVER 40KTS. INCREASING LOW LEVEL
MOISTURE THROUGH MID MORNING COULD BRING BRIEF MVFR VSBYS TO KLNK
AND KOMA...AND MAYBE SCATTERED CLOUDS BELOW FL020. OTHERWISE A
WIND SHIFT IS EXPECTED AT KOFK IN THE EARLY AFTERNOON WITH WINDS
BECOMING NORTHWESTERLY BUT REMAINING FAIRLY LIGHT.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
325 AM EDT WED MAR 14 2012
.SYNOPSIS...
AN UPPER LEVEL RIDGE WILL BUILD OVER THE REGION THROUGH THE REST OF
THE WORK WEEK RESULTING IN ABOVE NORMAL TEMPERATURES THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 305 AM WEDNESDAY...
SKIES ARE CLEAR ACROSS CENTRAL NC EARLY THIS MORNING...BUT
NORTHWESTERLY UPPER LEVEL FLOW CONTINUES TO SUPPORT SOME WEAK
DISTURBANCES ALOFT AND A COUPLE OF ISOLATED SHOWERS/STORMS HAVE
DEVELOPED OVER SOUTHWEST VA. WHILE THE AIRMASS EAST OF THE
MOUNTAINS IS QUITE A BIT DRIER THIS EVENING...THE 00Z KGSO RAOB DID
SHOW AROUND 500 J/KG OF SBCAPE...SO WE CANT ENTIRELY RULE OUT THAT
THESE SHOWERS COULD MOVE INTO THE NORTHWEST PIEDMONT. HOWEVER...THE
PROBABILITY SEEMS MUCH TOO LOW FOR MENTION IN THE FORECAST THIS
MORNING. THE OTHER CONCERN IS THE POTENTIAL FOR FOG PRIOR TO
SUNRISE. WHILE VISIBILITIES HAVE NOT DROPPED ACROSS NC...FOG IS
BEING REPORTED IN PORTIONS OF SC AND THE HRRR AVIATION FIELDS
CONTINUE TO SUGGEST FOG WILL DEVELOP NORTHWARD INTO THE SOUTHERN
PIEDMONT AND SANDHILLS IN THE NEXT COUPLE OF HOUR. LIGHT STIRRING
OF SURFACE WINDS ON THE EASTERN SIDE OF THE LEE TROUGH IS LIKELY
STAVING OFF FOG FOR THE MOMENT...BUT DEWPOINT DEPRESSIONS ARE DOWN
TO LESS THAN 5 DEGREES EVERYWHERE...SO WE WILL CONTINUE THE FORECAST
OF LOCALLY DENSE FOG ACROSS THE SOUTH AND EAST.
TODAY...THE 850MB RIDGE TO OUR SOUTHWEST WILL EXPAND ACROSS THE
SOUTHEAST STATES AS THE UPPER LEVEL RIDGE BEGINS TO AMPLIFY JUST
EAST OF THE MS VALLEY. HOWEVER...ON THE NORTHEASTERN PERIPHERY OF
THE RIDGE...MID LEVEL LAPSE RATES WILL CONTINUE TO BE MODESTLY STEEP
AROUND 6.5 TO 7 C/KM. DEWPOINTS IN THE TRIAD SHOULD DROP INTO THE
UPPER 40S WHICH WILL KEEP MLCAPE LOW. THERE IS A GOOD CHANCE THAT
DEWPOINTS WILL HOLD IN THE MID 50S IN THE SOUTHEAST...AND SREF
PROBABILITIES OF 500 J/KG OF SBCAPE AND MLCAPE ARE ABOVE 80
PERCENT. THE MSLP GRADIENT WILL BE WEAK WITH VERY LITTLE LOW LEVEL
FORCING FOR ACCENT...BUT WITH GUIDANCE GIVING LOW TO MID 80S FOR
HIGHS...THE SEA BREEZE MAY BE ABLE TO PUSH INLAND TOWARD THE
SANDHILLS AND PROVIDE AT LEAST SOME LOW LEVEL CONVERGENCE. ANY
SHOWERS OR STORMS SHOULD BE TOO ISOLATED FOR A MENTION OF SLIGHT
CHANCE...BUT THE ABOVE REASONING ALONG WITH SOME HI-RES WRF MODEL
SUPPORT WOULD SUGGEST IT CANT BE RULED OUT.
STATISTICAL GUIDANCE HAS BEEN PLAYING CATCH UP TO THE WARMING TREND
THE PAYS COUPLE OF DAYS IT SEEMS...SO WE WILL NUDGE HIGHS UP TO
81-83. RECORD HIGHS ARE 86/82 AT RDU/GSO.
FOG WILL BE POSSIBLE AGAIN TONIGHT...THROUGH SLIGHTLY LOWER
DEWPOINTS MAY MAKE FOG MORE PATCHY AND FOCUSED OVER THE EAST. LOWS
IN THE MID 50S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 305 AM WEDNESDAY...
THE MID LEVEL RIDGE WILL INCH NORTHEASTWARD THURSDAY WITH THE RIDGE
AXIS FORECAST TO LIE ACROSS GA...SC...AND SOUTHEASTERN NC. FORECAST
SOUNDINGS REMAIN MOSTLY UNCAPPED BUT DEEPER MIXING WILL HELP TO
LIMIT MLCAPE...AND WEAK FORCING WILL PRECLUDE ANY POP AT LEAST
THROUGH MID AFTERNOON. OPERATIONAL MODELS SHOW WEAK UPPER
DISTURANCES DRIFTING ATOP THE UPPER RIDGE AND THEN DIPPING SOUTHEAST
INTO NC/VA THURSDAY EVENING. SOME OF THE LONGER RANGE HI-RES WRF
MODELS SHOW CONVECTION UPSTREAM OF THE MOUNTAINS MOVING INTO WESTERN
NC/VA LATE AFTERNOON AND APPROACHING THE WESTERN PIEDMONT BY 00Z
FRIDAY. TIMING OF THE WEAK UPPER DISTURBANCES IS DIFFICULT TO
FORECAST...BUT THE FASTEST NAM SOLUTION WOULD BARELY HAVE ANY OF THE
CONVECTION INTO THE NORTHWEST PIEDMONT BY 21-00Z...SO WE WILL HOLD
OFF ON POPS UNTIL AFTER 21Z. THERE SHOULD BE MORE CUMULI AROUND
THURSDAYS AFTERNOON AS MOISTURE INCREASES NEAR THE TOP OF THE
BOUNDARY LAYER. AFTERNOON 1000-850MB THICKNESSES ARE FORECAST TO
RISE 3-5 METERS THURSDAY...SO HIGHS SHOULD ONLY BE A DEGREE OR TWO
WARMER AT BEST...82-85. -BLS
FOR THURSDAY NIGHT THROUGH FRIDAY NIGHT: THE WEAK SOUTHERN-STREAM
SHORTWAVE TROUGH NOW OVER NRN MEXICO WILL APPROACH THE SRN
APPALACHIANS THURSDAY NIGHT... PUSHING THE MID LEVEL RIDGE AXIS TO
OUR SE... WHILE AT THE SURFACE... LEE TROUGHING SHARPENS OVER THE
WESTERN PIEDMONT. AFTER A BRIEF RESPITE FROM THE HIGH
PRECIPITABLE-WATER AIR TODAY... VALUES OVER 200% OF NORMAL CURRENTLY
OVER TX ARE EXPECTED TO SURGE BACK NORTHWARD THROUGH THE NATION`S
MIDSECTION BY TONIGHT... THEN TRANSLATE EASTWARD... REACHING CENTRAL
NC THURSDAY NIGHT ACCOMPANIED BY INCREASING LOW LEVEL MOISTURE
TRANSPORT THAT CONTINUES THROUGH FRIDAY. THE WEAK WIND FIELD THROUGH
THE COLUMN (WHICH WILL REDUCE THE DEGREE OF DPVA CROSSING CENTRAL
NC) WILL YIELD JUST MINOR FORCING FOR ASCENT... AND THIS SHOULD
LIMIT COVERAGE SOMEWHAT DESPITE THE MOISTURE. BUT MODELS INDICATE AT
LEAST WEAK INSTABILITY... MLCAPE AROUND 200 J/KG THURSDAY NIGHT...
BECOMING MODERATE BY RISING TO 800-1200 J/KG MAINLY IN THE
CENTRAL/ERN CWA ON FRIDAY... AND THIS MAY PARTIALLY COMPENSATE FOR
THE WEAK DYNAMICS... ALTHOUGH DEEP LAYER SHEAR WILL REMAIN QUITE
WEAK AT JUST 15-20 KTS. WILL BRING SMALL CHANCE POPS INTO THE
WESTERN/CENTRAL CWA THURSDAY NIGHT... HOLDING POPS A BIT UNDER
STATISTICAL GUIDANCE GIVEN THAT SREF PROBABILITIES OF MEASURABLE
PRECIP ARE 30% OR LOWER. THESE PROBABILITIES CLIMB TO 50-70% DURING
FRIDAY AS THE VERY MOIST COLUMN AND DAYTIME HEATING/DESTABILIZATION
COMBINE WITH WEAK BUT TRACKABLE FORCING FEATURES... INCLUDING
IMPROVING UPPER DIVERGENCE AS THE MID-UPPER LEVEL WAVE DROPS INTO
THE AREA FROM THE NW. WILL RAISE POPS TO GOOD CHANCE BY FRIDAY
AFTERNOON... HIGHEST ALONG HIGHWAY 1 EAST. EXPECT A GRADUAL
DIMINISHING OF POPS NNW TO SSE FRIDAY NIGHT WITH THE LOSS OF HEATING
AND WITH MODELS INDICATING LOWER-PW AIR WORKING INTO THE NW CWA...
DUE IN PART TO THE BUILDING RIDGE JUST TO OUR WEST FROM THE LOWER
GREAT LAKES TO THE CENTRAL/WRN GULF... A RESULT OF THE STRONG
LONGWAVE TROUGH DIGGING OVER THE WESTERN CONUS. BUT WE SHOULD RETAIN
MOSTLY CLOUDY SKIES THROUGH THE NIGHT AS THE MID LEVEL SHEAR AXIS
SITS OVERHEAD WITH SURFACE TROUGHING HOLDING IN PLACE THROUGH THE
PIEDMONT. LITTLE CHANGE IN TEMPS WITH HIGHS IN THE UPPER 70S TO
AROUND 80... ALTHOUGH WILL ADD A DEGREE OR TWO TO ALREADY-WARM LOW
TEMPS... BRINGING THEM INTO THE UPPER 50S TO NEAR 60. -GIH
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 320 AM WEDNESDAY...
FOR SATURDAY/SATURDAY NIGHT: RECENT MODEL RUNS HAVE VARIED IN THEIR
HANDLING OF A NORTHERN STREAM WAVE LOCATED OVER ONTARIO THURSDAY
NIGHT... WHICH DROPS SOUTHEASTWARD OVER THE ST LAWRENCE VALLEY INTO
THE NORTHEAST AND NORTHERN MIDATLANTIC STATES. AFTER AMPLIFYING THIS
FEATURE STRONGLY TOWARD THE SW IN YESTERDAY`S RUNS... THE ECMWF IS
NOW MUCH WEAKER AND HOLDS IT WELL TO OUR NORTH WITHOUT ABSORBING THE
SOUTHERN STREAM WAVE OVER THE CAROLINAS... WHILE THE GFS IS NOW
STRONGER WITH A PROMINENT WAVE DROPPING SOUTHWARD TOWARD NC. GIVEN
THE STRONG TROUGHING IN THE WEST AND RESULTANT AMPLIFYING LONGWAVE
RIDGING EAST OF THE MISS VALLEY TOWARD THE APPALACHIANS... THE
WEAKER AND FARTHER-NORTH SOLUTION APPEARS MORE LIKELY. EXPECT THE
ASSOCIATED BACKDOOR SURFACE FRONT TO HOLD TO OUR NORTH THROUGH
SATURDAY NIGHT. PW VALUES WILL LIKELY HAVE FALLEN BUT SHOULD STILL
BE ABOVE NORMAL WITH NO SIGNIFICANT CAPPING EVIDENT. SO DESPITE THE
LIGHT WIND FIELD THROUGH THE COLUMN (INCLUDING VERY WEAK LOW LEVEL
MASS CONVERGENCE ALONG A WEAK SURFACE TROUGH) AND LACK OF
DYNAMICS... PATCHY SHOWERS WILL REMAIN POSSIBLE ESPECIALLY IN THE
EASTERN AND SOUTHERN CWA WHERE MODELS INDICATE MARGINAL INSTABILITY
(700-900 J/KG). THICKNESSES STAY 40-45 METERS ABOVE NORMAL
SUPPORTING HIGHS IN THE MID-UPPER 70S EVEN WITH VARIABLY CLOUDY
SKIES. LOWS 54-58 SATURDAY NIGHT AS COOL SURFACE HIGH PRESSURE OVER
THE NORTHEAST STATES BEGINS TO WORK SOUTHWARD ALONG THE EASTERN
SEABOARD WITH THE LEADING EDGE APPROACHING NC.
FOR SUNDAY THROUGH TUESDAY: EXPECT A SLIGHT COOLDOWN (AS THE SURFACE
HIGH BUILDS IN FROM THE NNE) BUT STILL ABOVE-NORMAL TEMPS FOR
CENTRAL NC THROUGH EARLY NEXT WEEK. THE BIG PICTURE REMAINS CLEAR...
BUT SOLUTIONS VARY REGARDING THE FORECAST DETAILS. LONGWAVE
TROUGHING CONTINUES TO DEEPEN OVER THE WESTERN STATES... WHILE
RIDGING HOLDS OVER THE MISS VALLEY INTO THE APPALACHIANS AND THE
BAGGY NORTHEAST-TO-SOUTHWEST-ORIENTED TROUGH SITS FROM NEAR OR JUST
OFF THE CAROLINA COAST INTO THE NW ATLANTIC. THE GFS`S STRONGER
TROUGH PUSHING TO OUR SW MEANS DRY WEATHER FOR CENTRAL NC... WHEREAS
THE ECMWF`S LINGERING MID LEVEL SHEAR AXIS AND SURFACE TROUGH ACROSS
THE CAROLINAS YIELDS A WETTER SOLUTION FOR OUR AREA. WITH LOW
CONFIDENCE IN SUCH WEAKLY FORCED FEATURES AND WITH LITTLE RUN-TO-RUN
MODEL CONSISTENCY... WILL KEEP ANY POPS AT SLIGHT CHANCE OR LOWER
FOR NOW. THICKNESSES AND THE LONGWAVE PATTERN SUPPORT CONTINUED WARM
TEMPS WITH HIGHS IN THE 70S AND LOWS IN THE 50S. -GIH
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 150 AM WEDNESDAY...
LIGHT WIND AND RELATIVELY HIGH SURFACE DEWPOINTS SHOULD LEAD TO FOG
DEVELOPMENT OVERNIGHT. WHILE VSBYS HAVE YET TO DROP AS OF 06Z...
LIFR VSBYS ARE BEING REPORTED OVER SC AND NEAR TERM GUIDANCE SHOWS
FOG DEVELOPING NORTHWARD OUT OF SC TO KFAY AND AT LEAST NEAR
KRWI/KRDU. THUS..THE CURRENT TAF WILL REFLECT IFR VSBYS AT THOSE
SITES BY 09Z...WITH THE POTENTIAL FOR LIFR VSBYS BETWEEN 09Z AND
13Z. CONFIDENCE IN DENSE FOG IS HIGHEST AT KFAY. IN THE
TRIAD...LOWER DEWPOINTS SHOULD PRECLUDE VSBYS DROPPING INTO
IFR...BUT A BRIEF PERIOD OF IFR CONDITIONS IS POSSIBLE PRIOR TO 13Z.
DURING THE DAY...WINDS WILL BE LIGHT AND VARIABLE AS AN UPPER LEVEL
RIDGE BUILDS TOWARD THE AREA AND THE SLP GRADIENT REMAINS WEAK. VFR
CONDITIONS WILL PREVAIL WITH MOSTLY CLEAR SKIES.
OUTLOOK...
IMPACTS INCLUDE LOCAL MORNING FOG POSSIBLE AGAIN OVERNIGHT
WEDNESDAY INTO THURSDAY MORNING. THE CHANCES FOR SHOWERS AND
THUNDERSTORMS INCREASE FRIDAY INTO SATURDAY AS WEAK LOW PRESSURE
DEVELOPS OVER THE MID-ATLANTIC AND A COLD FRONT APPROACHES FROM THE
NORTH. CURRENT LONG-TERM GUIDANCE SUPPORTS A GOOD POTENTIAL FOR IFR
CONDITIONS IN LOW CLOUDS LATE SATURDAY NIGHT AND SUNDAY MORNING IN
LINGERING MOISTURE ON A NORTHEAST SURFACE FLOW.
&&
.CLIMATE...
HERE ARE UPCOMING HIGH TEMPERATURES RECORDS...
AT RDU:
03/14: 86 IN 1990
03/15: 87 IN 1973
03/16: 86 IN 1945
AT GSO:
03/14: 82 IN 1990
03/15: 87 IN 1967
03/16: 85 IN 1945
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...SMITH
SHORT TERM...SMITH/HARTFIELD
LONG TERM...HARTFIELD
AVIATION...SMITH/DJF
CLIMATE...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
305 AM EDT WED MAR 14 2012
.SYNOPSIS...
AN UPPER LEVEL RIDGE WILL BUILD OVER THE REGION THROUGH THE REST OF
THE WORK WEEK RESULTING IN ABOVE NORMAL TEMPERATURES THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 305 AM WEDNESDAY...
SKIES ARE CLEAR ACROSS CENTRAL NC EARLY THIS MORNING...BUT
NORTHWESTERLY UPPER LEVEL FLOW CONTINUES TO SUPPORT SOME WEAK
DISTURBANCES ALOFT AND A COUPLE OF ISOLATED SHOWERS/STORMS HAVE
DEVELOPED OVER SOUTHWEST VA. WHILE THE AIRMASS EAST OF THE
MOUNTAINS IS QUITE A BIT DRIER THIS EVENING...THE 00Z KGSO RAOB DID
SHOW AROUND 500 J/KG OF SBCAPE...SO WE CANT ENTIRELY RULE OUT THAT
THESE SHOWERS COULD MOVE INTO THE NORTHWEST PIEDMONT. HOWEVER...THE
PROBABILITY SEEMS MUCH TOO LOW FOR MENTION IN THE FORECAST THIS
MORNING. THE OTHER CONCERN IS THE POTENTIAL FOR FOG PRIOR TO
SUNRISE. WHILE VISIBILITIES HAVE NOT DROPPED ACROSS NC...FOG IS
BEING REPORTED IN PORTIONS OF SC AND THE HRRR AVIATION FIELDS
CONTINUE TO SUGGEST FOG WILL DEVELOP NORTHWARD INTO THE SOUTHERN
PIEDMONT AND SANDHILLS IN THE NEXT COUPLE OF HOUR. LIGHT STIRRING
OF SURFACE WINDS ON THE EASTERN SIDE OF THE LEE TROUGH IS LIKELY
STAVING OFF FOG FOR THE MOMENT...BUT DEWPOINT DEPRESSIONS ARE DOWN
TO LESS THAN 5 DEGREES EVERYWHERE...SO WE WILL CONTINUE THE FORECAST
OF LOCALLY DENSE FOG ACROSS THE SOUTH AND EAST.
TODAY...THE 850MB RIDGE TO OUR SOUTHWEST WILL EXPAND ACROSS THE
SOUTHEAST STATES AS THE UPPER LEVEL RIDGE BEGINS TO AMPLIFY JUST
EAST OF THE MS VALLEY. HOWEVER...ON THE NORTHEASTERN PERIPHERY OF
THE RIDGE...MID LEVEL LAPSE RATES WILL CONTINUE TO BE MODESTLY STEEP
AROUND 6.5 TO 7 C/KM. DEWPOINTS IN THE TRIAD SHOULD DROP INTO THE
UPPER 40S WHICH WILL KEEP MLCAPE LOW. THERE IS A GOOD CHANCE THAT
DEWPOINTS WILL HOLD IN THE MID 50S IN THE SOUTHEAST...AND SREF
PROBABILITIES OF 500 J/KG OF SBCAPE AND MLCAPE ARE ABOVE 80
PERCENT. THE MSLP GRADIENT WILL BE WEAK WITH VERY LITTLE LOW LEVEL
FORCING FOR ACCENT...BUT WITH GUIDANCE GIVING LOW TO MID 80S FOR
HIGHS...THE SEA BREEZE MAY BE ABLE TO PUSH INLAND TOWARD THE
SANDHILLS AND PROVIDE AT LEAST SOME LOW LEVEL CONVERGENCE. ANY
SHOWERS OR STORMS SHOULD BE TOO ISOLATED FOR A MENTION OF SLIGHT
CHANCE...BUT THE ABOVE REASONING ALONG WITH SOME HI-RES WRF MODEL
SUPPORT WOULD SUGGEST IT CANT BE RULED OUT.
STATISTICAL GUIDANCE HAS BEEN PLAYING CATCH UP TO THE WARMING TREND
THE PAYS COUPLE OF DAYS IT SEEMS...SO WE WILL NUDGE HIGHS UP TO
81-83. RECORD HIGHS ARE 86/82 AT RDU/GSO.
FOG WILL BE POSSIBLE AGAIN TONIGHT...THROUGH SLIGHTLY LOWER
DEWPOINTS MAY MAKE FOG MORE PATCHY AND FOCUSED OVER THE EAST. LOWS
IN THE MID 50S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 305 AM WEDNESDAY...
THE MID LEVEL RIDGE WILL INCH NORTHEASTWARD THURSDAY WITH THE RIDGE
AXIS FORECAST TO LIE ACROSS GA...SC...AND SOUTHEASTERN NC. FORECAST
SOUNDINGS REMAIN MOSTLY UNCAPPED BUT DEEPER MIXING WILL HELP TO
LIMIT MLCAPE...AND WEAK FORCING WILL PRECLUDE ANY POP AT LEAST
THROUGH MID AFTERNOON. OPERATIONAL MODELS SHOW WEAK UPPER
DISTURANCES DRIFTING ATOP THE UPPER RIDGE AND THEN DIPPING SOUTHEAST
INTO NC/VA THURSDAY EVENING. SOME OF THE LONGER RANGE HI-RES WRF
MODELS SHOW CONVECTION UPSTREAM OF THE MOUNTAINS MOVING INTO WESTERN
NC/VA LATE AFTERNOON AND APPROACHING THE WESTERN PIEDMONT BY 00Z
FRIDAY. TIMING OF THE WEAK UPPER DISTURBANCES IS DIFFICULT TO
FORECAST...BUT THE FASTEST NAM SOLUTION WOULD BARELY HAVE ANY OF THE
CONVECTION INTO THE NORTHWEST PIEDMONT BY 21-00Z...SO WE WILL HOLD
OFF ON POPS UNTIL AFTER 21Z. THERE SHOULD BE MORE CUMULI AROUND
THURSDAYS AFTERNOON AS MOISTURE INCREASES NEAR THE TOP OF THE
BOUNDARY LAYER. AFTERNOON 1000-850MB THICKNESSES ARE FORECAST TO
RISE 3-5 METERS THURSDAY...SO HIGHS SHOULD ONLY BE A DEGREE OR TWO
WARMER AT BEST...82-85.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 110 PM TUESDAY...
SURFACE HIGH PRESSURE ORIENTED WEST-EAST ACROSS THE NORTHERN GULF
RETREATS EAST INTO THE ATLANTIC WITH INCREASING MOISTURE RETURN INTO
THE LOWER MISSISSIPPI AND TENNESSEE VALLEYS THURSDAY INTO FRIDAY.
INITIALLY THE BUILDING MID LEVEL RIDGE OVER THE EASTERN CONUS WILL
BLOCK THIS MOISTURE AND A VERY WARM DAY IS ON TAP THURSDAY.
THICKNESSES AND MOS GUIDANCE HAVE TRENDED UPWARDS...WITH LOW 80S NOW
WIDESPREAD AND NEAR RECORD MID 80S NOT OUT OF THE QUESTION. LOW
LEVEL MOISTURE WILL BE ON THE INCREASE THURSDAY NIGHT AS THE SURFACE
HIGH MOVES EAST ALLOWING MORE SOUTH TO SOUTHWEST FLOW. IN
ADDITION...AN UPPER WAVE MOVES ACROSS THE RIDGE AND A WEAK BACK DOOR
FRONT WILL BE SAGGING SOUTH INTO THE MID ATLANTIC. COULD SEE SOME
PATCHY LIGHT RAIN IN THE WEST LATE THURSDAY NIGHT...OTHERWISE
BECOMING MOSTLY CLOUDY AND MILD WITH LOWS IN THE MID 50S.
LONG-TERM GUIDANCE TRENDS SHOW A TENDENCY TO BE FARTHER WEST WITH
THE RIDGE AXIS ALOFT...WITH LOWER HEIGHTS OFFSHORE OVER THE WESTERN
ATLANTIC. THE ECMWF HAS TRENDED STRONGEST WITH UPPER-LEVEL LOW
PRESSURE MOVING OVER THE BROAD UPPER RIDGE...WHICH IN TURN PUSHES A
STRONGER COLD FRONT FROM THE NORTH THROUGH CENTRAL NORTH CAROLINA
EARLY IN THIS LONG-TERM PERIOD. THE GFS AND CANADIAN TREND WEAKER
AND GENERALLY SLOWER...AND THOUGH THE GFS HAS TRENDED LOWER WITH ITS
HEIGHTS ALOFT OFFSHORE...FRONTAL CONVERGENCE STILL APPEARS WEAKER
WITH WEAKER MID- AND UPPER-LEVEL FORCING THAT LINGERS LONGER INTO
THE WEEKEND.
GFSX MOS ENSEMBLE CHANCES FOR PRECIPITATION ARE CONSISTENTLY ABOVE
CLIMATOLOGY FRIDAY INTO SATURDAY...AND EVEN INTO SUNDAY...
DIMINISHING BY MONDAY AS DRIER AIR SHOULD GRADUALLY MOVE INTO
CENTRAL NORTH CAROLINA FROM THE NORTH AND NORTHEAST BEHIND ANY
SURFACE BOUNDARY. THE PATTERN OF DIMINISHING 850MB THETA-E FROM THE
NORTHEAST ON THE ECMWF DURING THE LATER PART OF THE WEEKEND APPEARS
REASONABLE...WITH MAINLY THE TIMING IN QUESTION. WILL FOCUS CHANCES
FOR SHOWERS HIGHER IN THE WESTERN PIEDMONT AND TOWARD THE VIRGINIA
BORDER FRIDAY NIGHT...WITH HIGHER CHANCES TRANSITIONING SOUTH
SATURDAY AND SATURDAY NIGHT AS THE SURFACE BOUNDARY MOVES SOUTH AND
MORE STABLE AIR GRADUALLY MOVES IN FROM THE NORTH. GIVEN SURFACE
RIDGING OVER THE SOUTHEAST STATES INTO THE EASTERN GULF...DO NOT
EXPECT ANY PERIOD TO BE A WASHOUT...WITH SCATTERED SHOWERS OR
PERIODS OF SHOWERS PRIMARILY EXPECTED. ABNORMALLY WARM THICKNESSES
AND COOLING ALOFT WITH TROUGHING COULD LEAD TO STEEP ENOUGH LAPSE
RATES TO PROVIDE FOR THUNDER...AS NOTED ON COARSE ECMWF MODEL
SOUNDINGS.
COOLER AIR WILL BE IN PLACE TUESDAY BUT THERE ARE CONSIDERABLE
DIFFERENCES IN MODELS CONCERNING SMALLER SCALE DETAILS WHICH WILL
DETERMINE SKY COVER AND THE POSSIBILITY OF SHOWERS IN THE
EAST...WHICH WILL BE NEARER IN PROXIMITY TO AN UPPER LOW OFFSHORE.
WILL HAVE A DRY FORECAST WITH A LOW PERCENTAGE OF CLOUD COVER
LEADING TO HIGHS IN THE MID 70S.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 150 AM WEDNESDAY...
LIGHT WIND AND RELATIVELY HIGH SURFACE DEWPOINTS SHOULD LEAD TO FOG
DEVELOPMENT OVERNIGHT. WHILE VSBYS HAVE YET TO DROP AS OF 06Z...
LIFR VSBYS ARE BEING REPORTED OVER SC AND NEAR TERM GUIDANCE SHOWS
FOG DEVELOPING NORTHWARD OUT OF SC TO KFAY AND AT LEAST NEAR
KRWI/KRDU. THUS..THE CURRENT TAF WILL REFLECT IFR VSBYS AT THOSE
SITES BY 09Z...WITH THE POTENTIAL FOR LIFR VSBYS BETWEEN 09Z AND
13Z. CONFIDENCE IN DENSE FOG IS HIGHEST AT KFAY. IN THE
TRIAD...LOWER DEWPOINTS SHOULD PRECLUDE VSBYS DROPPING INTO
IFR...BUT A BRIEF PERIOD OF IFR CONDITIONS IS POSSIBLE PRIOR TO 13Z.
DURING THE DAY...WINDS WILL BE LIGHT AND VARIABLE AS AN UPPER LEVEL
RIDGE BUILDS TOWARD THE AREA AND THE SLP GRADIENT REMAINS WEAK. VFR
CONDITIONS WILL PREVAIL WITH MOSTLY CLEAR SKIES.
OUTLOOK...
IMPACTS INCLUDE LOCAL MORNING FOG POSSIBLE AGAIN OVERNIGHT
WEDNESDAY INTO THURSDAY MORNING. THE CHANCES FOR SHOWERS AND
THUNDERSTORMS INCREASE FRIDAY INTO SATURDAY AS WEAK LOW PRESSURE
DEVELOPS OVER THE MID-ATLANTIC AND A COLD FRONT APPROACHES FROM THE
NORTH. CURRENT LONG-TERM GUIDANCE SUPPORTS A GOOD POTENTIAL FOR IFR
CONDITIONS IN LOW CLOUDS LATE SATURDAY NIGHT AND SUNDAY MORNING IN
LINGERING MOISTURE ON A NORTHEAST SURFACE FLOW.
&&
.CLIMATE...
HERE ARE UPCOMING HIGH TEMPERATURES RECORDS...
AT RDU:
03/14: 86 IN 1990
03/15: 87 IN 1973
03/16: 86 IN 1945
AT GSO:
03/14: 82 IN 1990
03/15: 87 IN 1967
03/16: 85 IN 1945
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...SMITH
SHORT TERM...SMITH
LONG TERM...DJF/MLM
AVIATION...SMITH/DJF
CLIMATE...HARTFIELD
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
336 AM CDT WED MAR 14 2012
.DISCUSSION...
UPPER LEVEL RIDGING AND PERSISTENT SOUTHERLY LOW LEVEL FLOW WILL
LEAD TO ABOVE-NORMAL TEMPERATURES ACROSS NORTH AND CENTRAL TEXAS
FOR THE NEXT SEVERAL DAYS. WITH ABUNDANT LOW LEVEL MOISTURE IN
PLACE...THERE IS SOME CONCERN FOR FOG DEVELOPMENT DURING THE
EARLY MORNING HOURS AS TEMPERATURES APPROACH DEWPOINT READINGS. IN
FACT THE LAST FEW HRRR CYCLES HAVE HINTED AT LOWERING VISIBILITIES
ACROSS PARTS OF THE AREA PRIOR TO SUNRISE. HOWEVER...WITH WINDS
REMAINING MAINLY IN THE 10-15 MPH RANGE...FEEL WE WILL BE DEALING
MAINLY WITH LOW STRATUS AND SURFACE VISIBILITIES SHOULD REMAIN
OVERALL OKAY.
THE NEXT CHALLENGE WILL BE POPS FOR NOW THROUGH NEXT WEEK. THE
ATMOSPHERE IS UNSTABLE TODAY WITH MODEL FORECAST SB CAPE APPROACHING
1500 J/KG THIS AFTERNOON. NAM ALSO ERODES THE CAP ALMOST
COMPLETELY BY MID AFTERNOON...WHILE GFS HOLDS ONTO A GOOD AMOUNT
OF CIN. BELIEVE THAT WITH THE LACK OF A TRIGGER OR ANY UPPER LEVEL
SUPPORT...CONVECTION WILL HAVE A DIFFICULT TIME TODAY AND WILL
KEEP POPS BELOW 20 PERCENT WITHOUT ANY MENTION OF PRECIP IN THE
FORECAST. A SUBTLE SHORTWAVE WILL THEN PASS OVERHEAD DURING THE
DAY TOMORROW. FEEL THIS WILL ALLOW FOR THE DEVELOPMENT OF AT LEAST
ISOLATED STORMS. FOR NOW WILL LEAVE 20 POPS IN AREAWIDE AND REFINE
IF NEEDED LATER. THE UPPER DISTURBANCE SHIFTS EAST OF THE AREA
ALONG WITH THE ASSOCIATED PRECIPITATION THURSDAY NIGHT.
BY FRIDAY IT LOOKS LIKE THE RIDGE WILL BE TOO STRONG FOR
SIGNIFICANT RAIN CHANCES. ONE THING TO KEEP AN EYE ON WILL BE
DRYLINE DEVELOPMENT TO OUR NORTHWEST FRIDAY EVENING. AT THIS TIME
IT LOOKS LIKE ANY ACTIVITY THAT GETS GOING SHOULD DIMINISH BEFORE
REACHING THE AREA FRIDAY NIGHT. IF ANYTHING HOLDS TOGETHER AN
UPWARD ADJUSTMENT OF POPS MAY BE NEEDED LATE FRIDAY FOR THE
NORTHWESTERN COUNTIES.
THE UPPER RIDGE WILL BEGIN TO SLOWLY BREAK DOWN OVER THE WEEKEND
AS A LARGE SCALE UPPER TROUGH DEVELOPS OVER THE WESTERN CONUS.
ISOLATED SHOWERS AND STORMS WILL BE POSSIBLE BOTH SATURDAY AND
SUNDAY...ESPECIALLY DURING PEAK HEATING IN THE AFTERNOON. RAIN
CHANCES WILL THEN INCREASE SIGNIFICANTLY EARLY NEXT WEEK AS THE
UPPER TROUGH DIGS SOUTHEASTWARD TOWARDS THE REGION. GFS AND ECMWF
ARE SIMILAR WITH THE EVOLUTION OF THIS SYSTEM WITH ONLY MINOR
VARIATIONS IN THE TIMING. LARGE SCALE ASCENT AHEAD OF THE SYSTEM
SHOULD LEAD TO WIDESPREAD PRECIPITATION BY MONDAY OR MONDAY NIGHT.
MODELS ARE SHOWING NEGATIVE TILT...AND RESPECTIVE MODEL SOUNDINGS
AND HODOGRAPHS APPEAR CONDUCIVE FOR SEVERE WEATHER POTENTIAL. IT
IS STILL FAR TOO EARLY FOR ANY SPECIFICS BUT CERTAINLY WORTH
WATCHING AS THE FIRST DAYS OF SPRING DRAW NEAR. LONG RANGE
GUIDANCE THEN POINTS TOWARDS TEMPERATURES FINALLY RETURNING TO
NEAR-NORMAL AROUND THE MIDDLE OF NEXT WEEK AS THE AFOREMENTIONED
UPPER TROUGH SHOVES EAST OF THE AREA AND THE NEXT FRONT MOVES
THROUGH.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 77 66 78 66 77 / 10 10 20 10 10
WACO, TX 78 67 78 64 77 / 10 10 20 10 10
PARIS, TX 79 62 77 60 77 / 10 10 20 20 10
DENTON, TX 77 67 78 64 77 / 10 10 20 10 10
MCKINNEY, TX 77 67 77 65 77 / 10 10 20 20 10
DALLAS, TX 77 67 78 65 77 / 10 10 20 10 10
TERRELL, TX 78 66 78 64 77 / 10 10 20 20 10
CORSICANA, TX 78 65 78 64 78 / 10 10 20 10 10
TEMPLE, TX 78 66 78 64 77 / 10 10 20 10 10
MINERAL WELLS, TX 77 63 79 63 77 / 10 10 20 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
58/30
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
325 AM CDT WED MAR 14 2012
.SHORT TERM...TODAY THROUGH THURSDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE HIGH
PRESSURE STRETCHING FROM THE SE U.S. TO THE CENTRAL GREAT
LAKES...WHILE A COLD FRONT IS HEADING EAST OVER THE NORTHERN
PLAINS. WARMER AND MORE HUMID AIR IS SURGING NE OVER THE CENTRAL
PLAINS WHERE DEWPOINTS AND TEMPERATURES ARE IN THE 50S AND 60S FROM
WESTERN IOWA TO KANSAS. AS THIS MOISTURE FLOWS INTO THE REGION
AHEAD OF THE FRONT LATE THIS AFTERNOON INTO TONIGHT...SMALL POPS ARE
THE MAIN FORECAST CONCERN FOR THIS FORECAST.
TODAY...STRONG SHORTWAVE MOVING NE OVER CENTRAL CANADA WILL PUSH A
WEAKENING COLD FRONT ACROSS THE MISSISSIPPI VALLEY THIS MORNING AND
INTO CENTRAL WISCONSIN THIS AFTERNOON. ANTICIPATE SE WINDS THIS
MORNING TO HOLD DEWPOINTS BACK SOMEWHAT...BUT SW WINDS THIS
AFTERNOON SHOULD BRING LOW TO MID 50S DEWPOINTS FROM KANSAS AND
OKLAHOMA INTO CENTRAL AND NORTHERN WISCONSIN. THE SW WINDS WILL
ALSO BRING PLENTY OF WARM AIR NE...WITH BOTH THE ECMWF AND NAM
SHOWING 18C AT 925MB...WHICH EQUATES TO MID TO UPPER 70S FOR HIGHS
OVER CENTRAL AND E-C WISCONSIN. AS THE FRONT APPROACHES THIS
AFTERNOON...A GENEROUS 77/56 PARCEL YIELDS ABOUT 2100 J/KG OF SB
CAPE AND 42 J/KG OF CIN AT STEVENS POINT. NORMALLY WOULDNT RULE OUT
CONVECTION ALONG THE FRONT WITH THAT SMALLISH LEVEL OF CIN...BUT
MID-LEVELS ARE AWFULLY DRY AND CONVERGENCE IS PRETTY WEAK ALONG THE
FRONT. WITH NO UPPER SUPPORT (MID-LEVEL HEIGHTS ACTUALLY
INCREASE)...HAVING TROUBLE ADDING ISOLATED POPS WHEN THINK ITS GOING
TO BE DIFFICULT JUST TO GENERATE CU. IF A STORM DOES POP...AMPLE
INSTABILITY COMBINED WITH LOW WET BULB ZERO HEIGHTS OF 7500 FT AND
MID-LEVEL DRY AIR SUGGEST A HAIL/WIND THREAT WOULD BE POSSIBLE.
CONFIDENCE IS TOO LOW THOUGH TO INCLUDE ISOLATED WORDING IN THE
FORECAST.
TONIGHT...THE FRONT WILL CONTINUE TO MOVE SLOWLY ACROSS THE REST OF
CENTRAL AND NORTHEAST WISCONSIN MOSTLY DURING THE EVENING HOURS.
THE AIRMASS ALONG THE BOUNDARY WILL BECOME INCREASINGLY MORE STABLE
AS NOCTURNAL COOLING SETS IN AND THINK A THREAT OF ELEVATED
CONVECTION IS SMALL WITH THE LLJ DEVELOPING EAST OF THE REGION.
WITH CONDITIONS ONLY BECOMING INCREASINGLY MORE HOSTILE TO
CONVECTION...JUSTIFYING POPS IS A DIFFICULT SELL IF GOING WITH A DRY
FORECAST IN THE AFTERNOON. WILL KEEP AN ISOLATED MENTION THOUGH TO
BLEND WITH SURROUNDING OFFICES. STATISTICAL GUIDANCE IS RATHER
BULLISH IN PRODUCING FOG TONIGHT ACROSS THE REGION. A DRY AIRMASS
ARRIVES NORTH OF THE FRONT OVER N-C WISCONSIN SO THINK THEY ARE
RELATIVELY SAFE. BUT CLOSER TO THE BOUNDARY...WHERE LIGHTER FLOW
AND ELEVATED DEWPOINTS RESIDE...THINK THERE IS POTENTIAL FOR FOG.
WILL ADD IT TO THE FORECAST.
THURSDAY...THE SURFACE FRONT WILL DROP INTO THE SOUTHERN GREAT LAKES
ON THURSDAY...WITH WINDS SHIFTING TO THE NE BEHIND THE BOUNDARY.
SINCE THE 850MB FRONT WILL HANG FARTHER BACK OVER CENTRAL AND NE
WISCONSIN...PLENTY OF LOW LEVEL MOISTURE WILL STICK AROUND AND WILL
GO WITH PARTLY TO MOSTLY CLOUDY CONDITIONS OVER NE WISCONSIN. NOT
OUT OF THE QUESTION THAT A COUPLE SHOWERS COULD DEVELOP OVER E-C
WISCONSIN BUT WILL LET LATER SHIFTS EVALUATE BEFORE GOING OUT OF
LINE WITH SURROUNDING OFFICES. QUITE A CHALLENGING TEMPERATURE
FORECAST DUE TO THE NE WINDS OFF LAKE MICHIGAN COMBINED WITH
POTENTIAL FOR CLOUD COVER AND A WARM AIRMASS IN PLACE. HAVE DROPPED
TEMPS NEXT TO THE BAY AND LAKE THOUGH ADMIT THAT POTENTIAL IS THERE
FOR THE LAKE INFLUENCE TO PENETRATE FARTHER INLAND. TEMPS WILL
MOSTLY BE IN THE 60S AWAY FROM THE BAY AND LAKE.
.LONG TERM...THURSDAY NIGHT THRU TUESDAY. MAIN FORECAST CHALLENGES
CONTINUE TO BE HOW WARM TEMPS WILL CLIMB...AND DETERMINING BEST
CHANCE FOR SHOWERS/STORMS.
MODELS FAIRLY CONSISTENT SHOWING SW FLOW ALOFT DEVELOPING LATE
THIS WEEK...AND CONTINUING INTO EARLY NEXT WEEK. VERY MILD AIR
WILL DOMINATE THE PERIOD...WITH MORE RECORDS LIKELY TO BE BROKEN.
925-850MB TEMPS SUPPORT TEMPS IN THE UPPER 60S AND 70S ACROSS
CENTRAL AND EAST-CENTRAL WI FROM SATURDAY-TUESDAY...WITH ONLY
SLIGHTLY COOLER TEMPS ACROSS THE NORTH. SIGNIFICANTLY COOLER TEMPS
ARE EXPECTED NEAR LAKE MICHIGAN WITH A PERSISTENT ONSHORE FLOW
STARTING FRIDAY.
WEAK SHORTWAVE PASSES NORTH OF THE AREA THURSDAY NIGHT...BUT WITH
WEAK LIFT AND LIMITED MOISTURE ABOVE 925MB...WILL CONTINUE WITH A
DRY FORECAST. MODELS SHOW THE POTENTIAL FOR FOG THURSDAY NIGHT AS
WINDS DIE OFF AND DEWPOINTS REMAINING IN THE 40S. BELIEVE MODELS
ARE BEING FOOLED WITH THE VERY WARM AIRMASS IN PLACE...AS
TEMP/DEWPOINT SPREADS REMAIN ABOVE 3 DEGREES FOR MOST LOCATIONS
THROUGH THE NIGHT...LIMITING FOG POTENTIAL. SOME MET/MAV GUIDANCE
EVEN SHOWING FOG WITH SPREADS NEAR 10 DEGREES. WILL ADD SOME
PATCHY FOG ACROSS THE FOX VALLEY AND LAKESHORE...AS SE WINDS OFF
LAKE MICHIGAN COULD BRING SOME COOLER...RELATIVELY MOIST AIR
INLAND...BUT FOG CHANCES NEED TO BE MONITORED FOR THE ENTIRE AREA.
MODELS SEEM TO BE FOCUSING ON LATE SATURDAY NIGHT AND SUNDAY
FOR THE NEXT BEST CHANCE FOR SHOWERS/STORMS ACROSS THE AREA...AS A
WEAK MID-LEVEL SHORTWAVE MOVES FROM THE SOUTHERN PLAINS INTO THE
WESTERN GREAT LAKES. NO OTHER REAL SUPPORT FOR CONVECTION UNDER
THIS SYNOPTIC PATTERN...SO WILL ONLY ADD SLIGHT CHANCE POPS IN FOR
NOW AND SEE HOW THIS SYSTEM DEVELOPS. TIMING THIS TYPE OF SYSTEM
WILL BE A CHALLENGE THIS FAR OUT...SO WOULD NOT BE SURPRISED IF
ADJUSTMENTS ARE NEEDED. UPPER RIDGE BUILDS OVER THE GREAT LAKES
FOR EARLY NEXT WEEK...AS DEEP TROUGH EJECTS OUT OF THE WESTERN
CONUS INTO THE PLAINS. THE RIDGE WILL KEEP STORM CHANCES WEST OF
THE AREA THROUGH AT LEAST TUESDAY...BEFORE THE RIDGE FINALLY
BREAKS DOWN ENOUGH TO ALLOW THE TROUGH TO PROGRESS SLOWLY
EASTWARD. HOWEVER...MODELS HAVE SIGNIFICANT DIFFERENCES IN TIMING
THIS TRANSITION...WITH THE ECMWF MUCH FASTER THAN THE GFS ON
WEDNESDAY. SOMETHING TO WATCH OVER THE NEXT FEW MODEL RUNS.
&&
.AVIATION...VFR CONDITIONS EXPECTED MOST OF THE PERIOD. WINDS
ALOFT WL CONT TO INCR TNGT...BUT PROBABLY NOT TO THE POINT TO MEET
LLWS CRITERIA. SOME MVRF CIGS COULD DEVELOP TOMORROW AFTN...ESP
ACRS THE NW 1/2 OF THE FCST AREA.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/BERSCH
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
316 AM CDT WED MAR 14 2012
TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM.
A MODERATE MID LEVEL WEST/SOUTHWEST FLOW WILL OCCUR TODAY AND
TONIGHT WITH ONLY WEAK...LESS THAN 2 UBAR/SEC UPWARD MOTION. 700 MB
RELATIVE HUMIDITY REMAINS DRY AND LITTLE MID/UPPER LEVEL DIVERGENCE
WITH
MAIN JET STREAK MOVING NORTHEAST ACROSS NORTH DAKOTA LATE THIS
AFTERNOON AND INTO SOUTHERN CANADA TONIGHT.
850 MB SOUTHWEST FLOW INCREASES TO 30 KNOTS THIS AFTERNOON THEN SAGS
SOUTH ACROSS NORTHERN ILLINOIS TONIGHT. LITTLE IN WAY OF
CONVERGENCE.
WEAK SOUTHEAST WINDS NEAR LAKE MICHIGAN EARLY THIS AFTERNOON SHOULD
BECOME MORE SOUTH TO SOUTHWEST WITH THE INCREASING GRADIENT. SOME
LAKE BREEZE POTENTIAL...BUT THIS WOULD NOT HAVE MUCH INLAND PUSH TO
IT.
MAIN FORECAST PROBLEM CENTERS ON INCREASING SURFACE TO 850 MB
MOISTURE. THE INCREASE IN DEWPOINTS INTO THE LOWER 60S BY 00Z ON
THE NAM APPEARS EXCESSIVE. THE NAM/GFS MOS DO INCREASE THE
DEWPOINTS INTO THE UPPER 50S TO AROUND 60...BUT THIS OCCURS DURING
THE EVENING. CLOSEST 60 DEWPOINT NOW IS OVER OKLAHOMA. WITH DEW
POINTS LIKELY LESS THAN MODELS INDICATE SO TOO WILL BE THE
INSTABILITY. MID LEVEL LAPSE RATES ARE QUITE STEEP...AROUND 9C/KM
BUT THERE IS VERY DRY AIR AROUND 7 THSD FT. GFS ALSO HAS A STRONGER
LOW LEVEL CAP THAN THE NAM. RUC IS SOMEWHAT IN BETWEEN. THEREFORE
EVEN WITH THE LOW LEVEL INCREASE IN MOISTURE A LACK OF A TRIGGER
WILL HAMPER DEEP MOIST CONVECTIVE POTENTIAL.
THERE WILL BE A COLD FRONT THAT SAGS SOUTH LATE TONIGHT IN RESPONSE
TO HIGH PRESSURE MOVING INTO THE LAKE SUPERIOR AREA.
THIS WILL BE VERY SHALLOW AND WILL LIKELY NOT PRESENT MUCH OF A
TRIGGER POTENTIAL. THE INCREASING MOISTURE AND WEAK WIND SHIFT WILL
POSE A RISK OF FOG DEVELOPMENT...POSSIBLY DENSE.
THURSDAY - CONFIDENCE...LOW TO MEDIUM
MAIN CONCERN CENTERS ON TEMPERATURES. BIG DIFFERENCES BETWEEN MET
AND MAV GUIDANCE NUMBERS. GFS ESSENTIALLY IGNORING THE LAKE. GIVEN
THE COLDER LAKE TEMPS PREFER LEANING ON THE TRENDS OF THE NAM IN THE
WIND/TEMPS IN THIS POST FRONTAL ENVIRONMENT. NAM 2 METER TEMP
STRUCTURE SUGGESTS INLAND BUST POTENTIAL CONCERN AS WELL. MET MOS
WAS A NICE COMPROMISE BETWEEN VERY COLD 2 METER TEMPS AND VERY WARM
LOOK OF THE GFS MAV MOS. SURFACE LOW/WEAK UPPER WAVE RIPPLES THROUGH
IN THE MORNING WITH ALL MODELS SHOWING LIGHT QPF IN THE SOUTHEAST
CWA. LINGERING ELEVATED CAPE WITH SOME WEAK 850-700 Q-VECTOR
CONVERGENCE. WILL CARRY SMALL POPS FOR ISOLATED STORM DUE TO THE
CAPE AND PROGGD QPF THOUGH OVERALL AIRMASS ABOVE 800 MILLIBARS IS
PARCHED AND FORCING IS MARGINAL. WITH THE COOLER AND MOIST FLOW
OFF THE LAKE WILL HAVE TO KEEP AN EYE OUT FOR MORE COVERAGE OF FOG/
STRATUS THAN CURRENTLY ADVERTISING. LIGHT WIND REGIME SETS UP FOR
THURSDAY NIGHT SO MAY BE A MORE PRIME TIME FOR THIS DEVELOPMENT
AND THIS COULD LINGER INTO FRIDAY MORNING.
FRIDAY - CONFIDENCE...MEDIUM
SOUTHERLY FLOW RETURNS WITH 925 TEMPS IN THE TEENS. STILL A LAKE
CONTRIBUTION THOUGH MUCH LESS THAN THURSDAY. STILL THINK THE MET MOS
HAS A BETTER HANDLE ON THINGS THAN THE GFS MOS...SO STEERED IN THAT
DIRECTION IN THE FAR EAST CLOSER TO LAKE MICHIGAN. WILL GO WITH THE
DRY LOOK PLAYED OUT BY THE GFS/ECMWF AND NOT LATCH ONTO THE
EXPLOSIVE VORT THEN NAM IS SHOWING IN CENTRAL WI MIDDAY TIME FRAME.
SATURDAY AND SUNDAY - CONFIDENCE...LOW
MILD AND MOIST FLOW WITH POTENTIAL FOR WEAK VORTICITY MAXIMA
TRIGGERING A FEW SHOWERS/THUNDERSTORMS FROM TIME TO TIME. NOT A LOT
OF ORGANIZATION TO ANY OF THESE WAVES BUT NECESSITATES SMALL POPS TO
ACCOUNT FOR THESE MOVING THROUGH. GFS DOES SUGGEST A CAP THAT MAY
HOLD SO THE LOWER POPS OK FOR NOW.
MONDAY AND TUESDAY - CONFIDENCE...LOW TO MEDIUM
DEEP UPPER TROUGH IN THE WESTERN CONUS WITH RIDGE IN THE EAST.
APPEARS WI WILL BE MORE IN THE ANTICYCLONIC GRIP OF THE RIDGE
KEEPING THINGS WARM AND DRY.
&&
.AVIATION/12Z TAFS/...SOME PATCHY IFR FOG POTENTIAL MAINLY IN LOW
AREAS AND RIVER VALLEYS EARLY THIS MORNING. THIS WOULD QUICKLY
DISSIPATE AFTER SUNRISE.
INCREASING LOW LEVEL MOISTURE LATE IN THE AFTERNOON COULD DEVELOP
SOME CUMULUS...BUT ENOUGH OF A CAP AND DRY AIR ABOVE SO LITTLE
DEVELOPMENT EXPECTED. ALTHOUGH A SLIGHT CHANCE OF A THUNDERSTORM
EXISTS...DUE TO THE LACK OF FORCING WILL KEEP THE TAF FORECASTS DRY.
A WEAK COLD FRONT WILL SAG SOUTH LATE TONIGHT...AND WITH THE
INCREASED MOISTURE SOME FOG POTENTIAL WILL INCREASE ALONG WITH THE
POSSIBILITY OF LIFR FOG.
&&
.MARINE...SOUTH WINDS WILL INCREASE THIS AFTERNOON BUT WIND SPEEDS
SHOULD BE BELOW SMALL CRAFT CRITERIA. A WEAK COLD FRONT WILL SAG
IN FROM THE NORTH LATE TONIGHT THEN A NORTHEAST FLOW AND LAKE
COOLING EXPECTED ON THURSDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
THURSDAY THROUGH TUESDAY...COLLAR
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1018 AM EDT WED MAR 14 2012
.UPDATE...
WHATS LEFT OF THE FOG OVER W GA EXPECTED TO QUICKLY IMPROVE.
DECENT INSTABILITY FORECAST OVER W AND CENTRAL GA WITH THE MAIN
UPPER SHORT WAVE PASSING BY THIS MORNING AND ANOTHER MOVING TO FAR
NW GA LATE DAY. WILL JUST NEED TO MONITOR THINGS AS THE 12Z NAM IS
PRODUCING NO PRECIP THIS AFTERNOON AND SPOTTY LOW AMOUNTS TONIGHT.
FORECAST HIGH TEMPERATURES RUNNING 13-16 DEGREES ABOVE NORMAL
TODAY AND 1-3 DEGREES BELOW RECORDS. BDL
&&
.PREV DISCUSSION... /ISSUED 746 AM EDT WED MAR 14 2012/
UPDATE...
WILL SEND A QUICK UPDATE TO UPDATE POPS ACROSS WEST CENTRAL
GEORGIA. PESKY SHOWERS IN HARALSON...POLK...AND PAULDING COUNTIES
ARE MAINTAINING THEMSELVES SO HAVE ADJUSTED POPS ACCORDINGLY.
TDP
SHORT TERM /TODAY THROUGH THURSDAY NIGHT/...
SHORTWAVE THAT MOVED THROUGH THE AREA LAST NIGHT CONTINUES TO
PRESS TOWARD THE COAST...AS RIDGING BUILDS ACROSS THE SOUTHEAST.
OVERALL...SHORT- TERM MODEL MASS FIELDS ARE FAIRLY SIMILAR BUT
HAVE SIDED WITH THE GFS AS IT AND THE ECMWF ARE IN BETTER
AGREEMENT... NAM IS A LITTLE FASTER AND A LITTLE MORE AGGRESSIVE
WITH THE MOISTURE.
BEST DEEP MOISTURE WILL BE SHUNTED SOUTH TODAY BY THE EXITING
SHORTWAVE BUT WITH TEMPERATURES CLIMBING INTO THE 80S JUST ABOUT
EVERYWHERE PLUS PLENTIFUL SURFACE MOISTURE...MLCAPE VALUES THIS
AFTERNOON CLIMB TO ABOVE 1000 J/KG ACROSS THE AREA. HRRR AND LOCAL
WRF DO DEVELOP CONVECTION THIS AFTERNOON BUT MAINLY LIMIT IT TO
THE SOUTHWEST CORNER. FOR THESE REASONS...HAVE INCLUDED SLIGHT
CHANCE POPS BUT KEPT POPS CONFINED MAINLY SOUTH. VERY LITTLE SHEAR
TO WORK WITH /LESS THAN 30M2/S2 0-6KM SHEAR/ SO DO NOT EXPECT
CONVECTION TO REALLY ORGANIZE...BUT LAPSE RATES REMAIN PRETTY
STEEP /AROUND 7C/KM/. OVERALL DO NOT REALLY EXPECT ANY SEVERE
THUNDERSTORMS...HOWEVER CENTRAL GEORGIA DID SEE LARGE HAIL LAST
NIGHT SO IT CANNOT BE TOTALLY RULED OUT.
AS MENTIONED...HIGH TEMPS TODAY EXPECTED TO CLIMB INTO THE 80S
JUST ABOUT EVERYWHERE...WITH MID 80S POSSIBLE ON THURSDAY. TODAY/S
HIGHS REMAIN JUST BELOW RECORD VALUES BUT THURSDAY/S FORECAST DOES
INCLUDE SOME RECORDS...SEE CLIMATE SECTION BELOW.
ANOTHER SHORTWAVE MOVES ACROSS THE OHIO VALLEY THURSDAY NIGHT INTO
FRIDAY...THUS POPS RETURN TO NORTH GEORGIA LATE IN THE SHORT-
TERM. OVERALL A VERY SUMMER-LIKE PATTERN WITH WARM TEMPS...A MOIST
BOUNDARY LAYER...AND A HIGH CAPE LOW SHEAR ENVIRONMENT.
TDP
LONG TERM /FRIDAY THROUGH TUESDAY/...
SUMMER HAS STARTED EARLY. A HIGH-AMPLITUDE RIDGE TAKES FIRM HOLD
OF THE EASTERN U.S. WITH GFS PUSHING 587 DM 500 MB HEIGHTS
THROUGH THE WEEKEND. ALL EXTENDED MODELS AND ENSEMBLES ARE
CONSISTENT IN THIS...SO CONFIDENCE IS FAIRLY HIGH FOR HIGHER THAN
NORMAL TEMPS. THEREFORE...I BUMPED MAX TEMPS UPWARD A FEW DEGREES
IN THE EXTENDED TO COUNTERACT MOS TENDENCIES TOWARD CLIMATOLOGICAL
NORMS. PRECIPITABLE WATER VALUES REMAIN MUCH HIGHER THAN NORMAL
FOR THIS PERIOD...SO INCREASED AFTERNOON POPS TO REFLECT
SCATTERED...SUMMER-LIKE CONVECTION FOR THE WEEKEND. GFS SLIDES
SLIGHTLY DRIER AIR MOVES INTO NORTH GEORGIA BY MONDAY...SO POP
CHANCES DIMINISH. AM NOT QUITE CONVINCED THIS WILL BE ENOUGH TO
ELIMINATE PRECIP CHANCES...ESPECIALLY WITH ONSHORE FLOW BEGINNING
AS SURFACE RIDGE CENTERS ON MID-ATLANTIC SEABOARD EARLY IN THE
WEEK. WILL GO WITH /LOW/ MOS POPS FOR NOW...BUT THEY MAY BE TOO
LOW.
27
CLIMATE...
RECORDS FOR 03-14
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 84 1918 33 1993 61 1933 16 1926
1918
KATL 82 1989 33 1993 64 1918 18 1993
1926
KCSG 84 1989 40 1993 65 1973 20 1993
1982
KMCN 85 1973 41 1993 67 1918 21 1926
1953
1918
RECORDS FOR 03-15
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 84 1921 43 1960 62 1990 19 1993
1989
KATL 81 1973 39 1901 64 1989 20 1993
1946
KCSG 83 1989 44 1960 66 1973 21 1993
KMCN 86 1977 42 1960 65 1990 20 1993
1973
RECORDS FOR 03-16
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 82 1945 37 1960 62 2002 19 1890
KATL 84 1945 34 1900 64 2002 18 1890
KCSG 85 2002 51 1969 65 2002 27 1988
1949
KMCN 87 1955 42 1900 65 1942 26 1916
RECORDS FOR 03-17
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 85 1945 39 2005 62 1945 23 1924
KATL 86 1945 38 1892 65 2002 23 1895
KCSG 88 2002 45 2005 67 2002 30 1981
1954
KMCN 88 1945 44 2005 65 1908 27 1988
RECORDS FOR 03-18
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 87 1921 45 1998 63 1908 23 1967
1941
1902
KATL 84 1982 30 1892 67 1908 20 1902
KCSG 89 1982 49 1988 64 1982 29 1967
KMCN 88 1908 43 1902 67 1908 28 2007
1941
RECORDS FOR 03-19
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 86 1982 45 1947 61 1908 22 1892
KATL 85 1982 44 1892 65 1927 17 1892
KCSG 88 1982 52 2001 66 1948 30 1985
1960
KMCN 88 1963 49 1947 64 1982 26 1967
1945 1902
1927
RECORDS FOR 03-20
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 86 1907 38 1906 62 1948 20 1923
KATL 86 1907 36 1906 67 1948 17 1923
KCSG 85 2004 46 2001 66 1982 31 1956
1996 1948 1949
KMCN 90 1907 45 1906 67 1907 23 1923
AVIATION...
12Z UPDATE...
WIDESPREAD VLIFR CONDITIONS ACROSS THE AREA WITH DENSE FOG NOTED.
THE ONE EXCEPTION IS ATL...VLIFR CONDITIONS SURROUNDING THE
AIRPORT BUT ATL ITSELF HAS NOT DROPPED YET. BEGINNING TO SEE SOME
IMPROVEMENT...WITH VFR EXPECTED JUST ABOUT EVERYWHERE BY 14Z.
ADDED VCSH TO THE METRO TAFS TO COVER ISOLATED CONVECTION ON THE
WEST SIDE OF ATLANTA. OTHERWISE...VFR FOR THE REST OF THE DAY WITH
SCT CU 3-4KFT THIS AFTERNOON AND LIGHT WESTERLY WINDS. GUIDANCE
HINTING AT ANOTHER IFR/LIFR VSBY EPISODE THURSDAY MORNING BUT FOR
NOW HAVE ONLY INTRODUCED MVFR CIGS.
//ATL CONFIDENCE...
06Z UPDATE...
HIGH ON WINDS.
MEDIUM ON CIGS/VSBY THIS MORNING AND AFTER 06Z THURSDAY.
OTHERWISE HIGH ON CIGS/VSBY.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 82 54 85 58 / 10 10 10 20
ATLANTA 80 61 83 62 / 10 10 20 20
BLAIRSVILLE 75 51 76 54 / 10 10 20 30
CARTERSVILLE 80 51 81 54 / 20 10 20 20
COLUMBUS 83 58 85 61 / 20 10 10 10
GAINESVILLE 79 57 82 60 / 10 10 20 20
MACON 83 54 84 58 / 20 10 10 10
ROME 82 52 81 55 / 10 10 30 30
PEACHTREE CITY 81 50 82 54 / 20 10 10 10
VIDALIA 83 57 85 59 / 20 10 5 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
746 AM EDT WED MAR 14 2012
.UPDATE...
WILL SEND A QUICK UPDATE TO UPDATE POPS ACROSS WEST CENTRAL
GEORGIA. PESKY SHOWERS IN HARALSON...POLK...AND PAULDING COUNTIES
ARE MAINTAINING THEMSELVES SO HAVE ADJUSTED POPS ACCORDINGLY.
TDP
&&
.PREV DISCUSSION... /ISSUED 333 AM EDT WED MAR 14 2012/
SHORT TERM /TODAY THROUGH THURSDAY NIGHT/...
SHORTWAVE THAT MOVED THROUGH THE AREA LAST NIGHT CONTINUES TO
PRESS TOWARD THE COAST...AS RIDGING BUILDS ACROSS THE SOUTHEAST.
OVERALL...SHORT-TERM MODEL MASS FIELDS ARE FAIRLY SIMILAR BUT HAVE
SIDED WITH THE GFS AS IT AND THE ECMWF ARE IN BETTER AGREEMENT...
NAM IS A LITTLE FASTER AND A LITTLE MORE AGGRESSIVE WITH THE
MOISTURE.
BEST DEEP MOISTURE WILL BE SHUNTED SOUTH TODAY BY THE EXITING
SHORTWAVE BUT WITH TEMPERATURES CLIMBING INTO THE 80S JUST ABOUT
EVERYWHERE PLUS PLENTIFUL SURFACE MOISTURE...MLCAPE VALUES THIS
AFTERNOON CLIMB TO ABOVE 1000 J/KG ACROSS THE AREA. HRRR AND LOCAL
WRF DO DEVELOP CONVECTION THIS AFTERNOON BUT MAINLY LIMIT IT TO
THE SOUTHWEST CORNER. FOR THESE REASONS...HAVE INCLUDED SLIGHT
CHANCE POPS BUT KEPT POPS CONFINED MAINLY SOUTH. VERY LITTLE SHEAR
TO WORK WITH /LESS THAN 30M2/S2 0-6KM SHEAR/ SO DO NOT EXPECT
CONVECTION TO REALLY ORGANIZE...BUT LAPSE RATES REMAIN PRETTY
STEEP /AROUND 7C/KM/. OVERALL DO NOT REALLY EXPECT ANY SEVERE
THUNDERSTORMS...HOWEVER CENTRAL GEORGIA DID SEE LARGE HAIL LAST
NIGHT SO IT CANNOT BE TOTALLY RULED OUT.
AS MENTIONED...HIGH TEMPS TODAY EXPECTED TO CLIMB INTO THE 80S
JUST ABOUT EVERYWHERE...WITH MID 80S POSSIBLE ON THURSDAY. TODAY/S
HIGHS REMAIN JUST BELOW RECORD VALUES BUT THURSDAY/S FORECAST DOES
INCLUDE SOME RECORDS...SEE CLIMATE SECTION BELOW.
ANOTHER SHORTWAVE MOVES ACROSS THE OHIO VALLEY THURSDAY NIGHT INTO
FRIDAY...THUS POPS RETURN TO NORTH GEORGIA LATE IN THE SHORT-
TERM. OVERALL A VERY SUMMER-LIKE PATTERN WITH WARM TEMPS...A MOIST
BOUNDARY LAYER...AND A HIGH CAPE LOW SHEAR ENVIRONMENT.
TDP
LONG TERM /FRIDAY THROUGH TUESDAY/...
SUMMER HAS STARTED EARLY. A HIGH-AMPLITUDE RIDGE TAKES FIRM HOLD
OF THE EASTERN U.S. WITH GFS PUSHING 587 DM 500 MB HEIGHTS
THROUGH THE WEEKEND. ALL EXTENDED MODELS AND ENSEMBLES ARE
CONSISTENT IN THIS...SO CONFIDENCE IS FAIRLY HIGH FOR HIGHER THAN
NORMAL TEMPS. THEREFORE...I BUMPED MAX TEMPS UPWARD A FEW DEGREES
IN THE EXTENDED TO COUNTERACT MOS TENDENCIES TOWARD CLIMATOLOGICAL
NORMS. PRECIPITABLE WATER VALUES REMAIN MUCH HIGHER THAN NORMAL
FOR THIS PERIOD...SO INCREASED AFTERNOON POPS TO REFLECT
SCATTERED...SUMMER-LIKE CONVECTION FOR THE WEEKEND. GFS SLIDES
SLIGHTLY DRIER AIR MOVES INTO NORTH GEORGIA BY MONDAY...SO POP
CHANCES DIMINISH. AM NOT QUITE CONVINCED THIS WILL BE ENOUGH TO
ELIMINATE PRECIP CHANCES...ESPECIALLY WITH ONSHORE FLOW BEGINNING
AS SURFACE RIDGE CENTERS ON MID-ATLANTIC SEABOARD EARLY IN THE
WEEK. WILL GO WITH /LOW/ MOS POPS FOR NOW...BUT THEY MAY BE TOO
LOW.
27
CLIMATE...
RECORDS FOR 03-14
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 84 1918 33 1993 61 1933 16 1926
1918
KATL 82 1989 33 1993 64 1918 18 1993
1926
KCSG 84 1989 40 1993 65 1973 20 1993
1982
KMCN 85 1973 41 1993 67 1918 21 1926
1953
1918
RECORDS FOR 03-15
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 84 1921 43 1960 62 1990 19 1993
1989
KATL 81 1973 39 1901 64 1989 20 1993
1946
KCSG 83 1989 44 1960 66 1973 21 1993
KMCN 86 1977 42 1960 65 1990 20 1993
1973
RECORDS FOR 03-16
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 82 1945 37 1960 62 2002 19 1890
KATL 84 1945 34 1900 64 2002 18 1890
KCSG 85 2002 51 1969 65 2002 27 1988
1949
KMCN 87 1955 42 1900 65 1942 26 1916
RECORDS FOR 03-17
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 85 1945 39 2005 62 1945 23 1924
KATL 86 1945 38 1892 65 2002 23 1895
KCSG 88 2002 45 2005 67 2002 30 1981
1954
KMCN 88 1945 44 2005 65 1908 27 1988
RECORDS FOR 03-18
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 87 1921 45 1998 63 1908 23 1967
1941
1902
KATL 84 1982 30 1892 67 1908 20 1902
KCSG 89 1982 49 1988 64 1982 29 1967
KMCN 88 1908 43 1902 67 1908 28 2007
1941
RECORDS FOR 03-19
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 86 1982 45 1947 61 1908 22 1892
KATL 85 1982 44 1892 65 1927 17 1892
KCSG 88 1982 52 2001 66 1948 30 1985
1960
KMCN 88 1963 49 1947 64 1982 26 1967
1945 1902
1927
RECORDS FOR 03-20
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 86 1907 38 1906 62 1948 20 1923
KATL 86 1907 36 1906 67 1948 17 1923
KCSG 85 2004 46 2001 66 1982 31 1956
1996 1948 1949
KMCN 90 1907 45 1906 67 1907 23 1923
&&
.AVIATION...
12Z UPDATE...
WIDESPREAD VLIFR CONDITIONS ACROSS THE AREA WITH DENSE FOG NOTED.
THE ONE EXCEPTION IS ATL...VLIFR CONDITIONS SURROUNDING THE
AIRPORT BUT ATL ITSELF HAS NOT DROPPED YET. BEGINNING TO SEE SOME
IMPROVEMENT...WITH VFR EXPECTED JUST ABOUT EVERYWHERE BY 14Z.
ADDED VCSH TO THE METRO TAFS TO COVER ISOLATED CONVECTION ON THE
WEST SIDE OF ATLANTA. OTHERWISE...VFR FOR THE REST OF THE DAY WITH
SCT CU 3-4KFT THIS AFTERNOON AND LIGHT WESTERLY WINDS. GUIDANCE
HINTING AT ANOTHER IFR/LIFR VSBY EPISODE THURSDAY MORNING BUT FOR
NOW HAVE ONLY INTRODUCED MVFR CIGS.
//ATL CONFIDENCE...
06Z UPDATE...
HIGH ON WINDS.
MEDIUM ON CIGS/VSBY THIS MORNING AND AFTER 06Z THURSDAY.
OTHERWISE HIGH ON CIGS/VSBY.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 82 54 85 58 / 10 10 10 20
ATLANTA 80 61 83 62 / 20 10 20 20
BLAIRSVILLE 75 51 76 54 / 10 10 20 30
CARTERSVILLE 80 51 81 54 / 20 10 20 20
COLUMBUS 83 58 85 61 / 20 10 10 10
GAINESVILLE 79 57 82 60 / 10 10 20 20
MACON 83 54 84 58 / 20 10 10 10
ROME 82 52 81 55 / 10 10 30 30
PEACHTREE CITY 81 50 82 54 / 20 10 10 10
VIDALIA 83 57 85 59 / 20 10 5 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR THE
FOLLOWING ZONES: BALDWIN...BANKS...BARROW...BIBB...BLECKLEY...
BUTTS...CARROLL...CHATTAHOOCHEE...CHEROKEE...CLARKE...CLAYTON...
COBB...COWETA...CRAWFORD...CRISP...DEKALB...DODGE...DOOLY...
DOUGLAS...EMANUEL...FAYETTE...FORSYTH...GLASCOCK...GREENE...
GWINNETT...HALL...HANCOCK...HARRIS...HEARD...HENRY...HOUSTON...
JACKSON...JASPER...JEFFERSON...JOHNSON...JONES...LAMAR...
LAURENS...MACON...MADISON...MARION...MERIWETHER...MONROE...
MONTGOMERY...MORGAN...MUSCOGEE...NEWTON...NORTH FULTON...
OCONEE...OGLETHORPE...PAULDING...PEACH...PIKE...PULASKI...
PUTNAM...ROCKDALE...SCHLEY...SOUTH FULTON...SPALDING...STEWART...
SUMTER...TALBOT...TALIAFERRO...TAYLOR...TELFAIR...TOOMBS...
TREUTLEN...TROUP...TWIGGS...UPSON...WALTON...WARREN...
WASHINGTON...WEBSTER...WHEELER...WILCOX...WILKES...WILKINSON.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
721 AM EDT WED MAR 14 2012
.SYNOPSIS...
ISSUED AT 413 AM EDT WED MAR 14 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG OVER MN
BTWN CLOSED LO SHIFTING SEWD THRU QUEBEC AND A MEAN TROF ALONG THE W
COAST. WITH CWA UNDER THE CONFLUENT NW FLOW ALF/12HR H3 RISES AOA
100M...ASSOCIATED SFC HI PRES RDG IS BRINGING TRANQUIL WX/MOCLR
SKIES. AIRMASS IN PLACE IS ALSO RELATIVELY DRY PER LOCAL 00Z
RAOBS...SO SFC TEMPS HAVE FALLEN AOB 32 AT MANY INTERIOR COLD
LOCATIONS WITH THE MOCLR SKIES/LGT WINDS. BUT A MUCH WARMER AIRMASS
IS EVIDENT JUST TO THE W UNDER THE STRONG SLY FLOW BTWN THE SFC HI
PRES RDG OVER THE GRT LKS AND LOWER PRES IN THE HI PLAINS ASSOCIATED
WITH STRONG SHRTWV LIFTING NEWD THRU SW CAN TO THE E OF TROF ALONG
THE W COAST. 00Z H85 TEMPS REACHED AOA 15C ALL THE WAY UP TO GLASGOW
MONTANA AND BISMARCK...AND SFC HI TEMPS WERE UP TO 75 IN EASTERN
MONTANA AND WRN NDAKOTA UNDER THIS WARM SURGE. PIERRE SDAKOTA
REPORTED A MAX TEMP OF 82. THE AIRMASS IN THE CENTRAL AND NRN PLAINS
IS VERY DRY PER 00Z PWAT OF 0.14/0.17 AT RAPID CITY SDAKOTA/NORTH
PLATTE NEBRASKA. BUT A SURGE OF HIER SFC DWPTS IS NOTED MOVING N FM
THE SRN PLAINS...WITH SFC DWPTS AT 03Z UP TO 55 AT KANSAS CITY UNDER
THE STRONG S WINDS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 413 AM EDT WED MAR 14 2012
TODAY...AS SFC HI PRES SHIFTS INTO THE MID ATLANTIC STATES AND SFC
TROF/COLD FNT ASSOCIATED WITH DEEP SHRTWV LIFTING FM SW CAN TOWARD
HUDSON BAY MOVES INTO WRN LK SUP IN THE AFTN...STRONGER SSW FLOW
UNDER SHARPER PRES GRADIENT BTWN THESE FEATURES IS FCST TO LIFT H85
TEMPS UP TO 12-14C THIS AFTN. ALTHOUGH SOME OF THE MORE COPIOUS LLVL
MSTR IS FCST TO PUSH IN THIS AFTN...THE ARRIVAL OF THIS MSTR WL
COINCIDE WITH PEAK HEATING TIME...SO THERE SHOULD NOT BE MUCH IN THE
WAY OF CLD COVER AHEAD OF THE APRCHG TROF/FNT. WITH PLENTY OF
SUNSHINE AND MIXING TO H85 ON NAM FCST SDNGS...EXPECT TEMPS OVER THE
INTERIOR W TO REACH 70 TO 75. AREAS OVER THE E HALF WL BE COOLER
DOWNWIND OF THE MODIFYING INFLUENCE OF LK MI. DAILY RECORD HI TEMPS
OF 62 AT IWD...56 AT CMX...67 AT IMT...AND 60 AT THE MQT NWS OFFICE
ARE IN SERIOUS JEOPARDY. THE ARRIVAL OF THE SFC COLD FNT LATE OVER
THE W WL BRING SOME MORE CLDS/COOLER TEMPS TOWARD EVNG...BUT THE
OVERALL AIRMASS WL BE TOO DRY WITH PERSISTENT INVRN H75-8 TO SUPPORT
ANY PCPN CONSIDERING THE ABSENCE OF H5 FALLS WITH PASSAGE OF THE
MAIN DYNAMICS WELL TO THE N CLOSER TO SHRTWV TRACK. SO IGNORED THE
LGT QPF GENERATED BY THE 00Z GFS.
TNGT...AS MAIN SHRTWV TO THE N MOVES ACRS HUDSON BAY...SFC COOL FNT
WL DRIFT W-E ACRS THE CWA AND INTO NRN LWR MI BY 12Z THU. MODELS...
ESPECIALLY THE GFS...GENERATE SPOTTY QPF OVER MAINLY THE SE ZNS IN
THE EVNG JUST AHEAD OF THE TROF. SINCE THE INCOMING LLVL MSTR DOES
GET DEEPER AND UP TO H85-8 PER NAM FCST SDNGS...OPTED TO MAINTAIN
SCHC POPS FM ROUGHLY MNM TO ERY THRU ABOUT 06Z...WHEN DRYING WITH A
WSHFT TO THE W BEHIND THE FROPA WL ADVECT DRIER AIR EWD. OPTED TO
ADD MENTION OF ELEVATED TS GIVEN STEEP MID LVL LAPSE RATES ABV LLVL
MOISTENING. PERSISTENCE OF INVRN H8-75 IN ABSENCE OF SGNFT MID LVL
DYNAMICS WL BE THE LIMITING FACTOR FOR ANY SHRA/TS. ALTHOUGH THERE
WL BE DRYING ALF AS HI PRES MOVES ACRS NW LK SUP UNDER WSW FLOW
ALF... VARIOUS GUIDANCE SHOWS MORE LLVL MSTR PERSISTING EVEN AFT THE
FROPA. SO TENDED TO MAINTAIN MORE CLD COVER THRU THE NGT WHERE THE
NW VEERING N WIND WL UPSLOPE.
THU...WITH PERSISTENT WSW FLOW ALF BTWN MEAN UPR RDG OVER THE SE
CONUS AND TROFFING OUT W...SFC HI PRES IS PROGGED TO DRIFT INTO
QUEBEC...LEAVING A SFC RDG OVER THE UPR LKS. ALTHOUGH DRY AIR IN THE
MID LVLS WL RESULT IN A PCPN-FREE DAY...VARIOUS MODELS CONTINUE TO
SHOW LINGERING LLVL MSTR WITH SHALLOW COOL AIR INFUSION MAINTAINING
FAIRLY SHARP SFC-BASED INVRN. TRICKY TEMPS FCST FOR THU CONSIDERING
DIFFERENCES IN LLVL MSTR SHOWN BY THE VARIOUS MODELS AND POTENTIAL
FOR MORE PERSISTENT ST/SC. TENDED COOLEST NEAR THE LK SHORES WITH
LGT NE FLOW TENDING TO VEER E AND GREATER HEATING INLAND SUPPORTING
LK BREEZE COOLING. ALTHOUGH TEMPS WL BE CONSIDERABLY COOLER THAN
TDAY AND PROBABLY CLOSER TO THE LOWER NAM GUIDANCE GIVEN RATHER HI
STABILITY SHOWN ON FCST SDNGS/POTENTIAL LO CLDS...READINGS WL STILL
BE WELL ABV NORMAL FOR THE IDES OF MARCH.
THU NGT...MAJORITY OF MODELS SHOW WEAK SHRTWV MOVING IN FM THE
WSW...CAUSING LGT LLVL FLOW TO VEER MORE TO THE S. WHILE THIS WSHFT
MIGHT LIMIT UPSLOPE CLD OFF LK SUP...CONCERN SOME ST/SC COULD DRIFT
IN FM LK MI/BAY OF GREEN BAY. SINCE THE FLOW WL BE LGT AND THE MID
LVLS DRY...ALSO MAINTAINED PATCHY FOG IN THE FCST OVER THE E
DOWNWIND OF LK MI.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 413 AM EDT WED MAR 14 2012
WEAK DISTURBANCE THAT MOVED JUST N OF LK SUPERIOR ON THURS NIGHT
WILL SHIFT E OF THE AREA ON FRI...ALLOWING THE UPPER RIDGE TO
RE-ESTABLISH ITSELF OVER THE UPPER GREAT LAKES ON FRI AND FRI NIGHT.
FRI... MOSTLY SUNNY DUE TO DRY AIR AND SUBSIDENCE UNDER THE UPPER
RIDGE AND EXITING SFC HIGH. MIX TO H900 WOULD YIELD TEMPS IN THE
LOW-MID 60S AWAY FROM LK MI INFLUENCES. MODEL CONSENSUS IS A LIGHT
SE BREEZE...WHICH COULD PRODUCE ONSHORE FLOW OVER THE KEWEENAW
PENINSULA AND LEADS TO THE POTENTIAL FOR LIGHT LK BREEZES OVER THE W
AND NCTNRL. LATEST NAM HAS TRENDED TOWARDS STRONGER WINDS AS IT
TRIES TO MIX INTO THE STRONGER WINDS ALOFT...WHICH WOULD LIMIT LK
BREEZE POTENTIAL.
FRI NIGHT...SRLY FLOW INCREASES AS THE AREA IS BETWEEN SFC HIGH OVER
SW QUEBEC AND LOW NEAR LK WINNIPEG. THIS TRIES TO PULL ADDITIONAL
LLVL MOISTURE OVER THE AREA. GFS IS THE MOST AGGRESSIVE WITH
THIS...WHICH ATTEMPTS TO SOCK THE AREA IN WITH LOW CLOUDS BELOW THE
INVERSION AROUND H850-800. NAM A LITTLE SLOWER...BUT EVENTUALLY
SHOWS A SIMILAR SITUATION. NOT ENTIRELY CONFIDENT THIS WILL
OCCUR...BUT WILL TREND TOWARDS A MORE CLOUDY SOLN. IF THIS LLVL
MOISTURE DOES OCCUR...EXPECT FOG TO DEVELOP OVER LK MI AND MOVE INTO
THE ERN CWA. HAVE ADDED A MENTION OF PATCHY FOG NEAR/OVER LK MI AND
ADDED IT OVER NRN LK SUPERIOR OVERNIGHT.
MODELS STILL OUTPUTTING PCPN...LIKELY LIGHT DRIZZLE...IN ONLY A 1 TO
MAYBE 2KFT AREA OF MOISTURE/CLOUDS NEAR THE SFC. REALLY NOT BUYING
THAT SITUATION...SO WILL CAP POPS JUST BELOW SLIGHT CHANCES.
DAYS 4 THROUGH 7 /SATURDAY THROUGH TUESDAY/...
ANOMALOUS H500 HEIGHTS...AROUND 2-3 STD DEV ABOVE NORMAL FOR
MID-LATE MARCH WILL REMAIN OVER THE AREA FOR THE EXTENDED PERIOD.
OTHER THAN A COUPLE WEAK IMPULSES MOVING THROUGH THE SWRLY FLOW
ALOFT...EXPECT A FAIRLY WARM/DRY PERIOD TO CONTINUE INTO THE FIRST
HALF OF NEXT WEEK.
BEST OPPORTUNITY FOR A WEAK WAVE LOOKS TO BE ON SAT AFTN INTO SUN
MORN. MODELS SHOWING SOME MOISTURE TO WORK WITH ABOVE H850 AND
ELEVATED INSTABILITY WOULD SUPPORT THE POTENTIAL FOR THUNDER IF ANY
SHOWERS DEVELOP WITH THE WEAK SHORTWAVE. OTHERWISE...DON/T SEE ANY
SIGNIFICANT WAVES OR FORCING AFFECTING THE AREA.
MAIN FOCUS FOR THE EXTENDED IS LLVL MOISTURE AND TEMPS. 00Z GFS
CONTINUES TO SHOW ABUNDANT LLVL MOISTURE BELOW THE H850 INVERSION
THROUGH THE EXTENDED PERIOD. 12Z ECMWF...EVEN WITH THE LIMITED LOWER
LEVELS AVAILABLE DOESN/T SHOW THAT EXTENT OF LLVL MOISTURE. GEM DOES
HINT AT IT AND WONDERING IF IT WILL BE DIURNALLY DRIVEN WITH MORE
CLOUDS AT NIGHT AND THEN ATTEMPT TO MIX OUT DURING THE DAY. IT IS
ONE OF THOSE TOUGH SITUATIONS...DUE TO NO SIGNIFICANT CHANGES AND
THE DECENT CAP...WHICH COULD LEAD TO LOW CLOUDS BECOMING TRAPPED
BELOW THE INVERSION AND STRUGGLING TO BREAK OUT. DON/T HAVE ENOUGH
CONFIDENCE ONE WAY OR ANOTHER TO BUCK THE MODEL CONSENSUS AND WILL
LEAVE IT AS IS. MODELS TRYING TO DROP A HUNDREDTH OF QPF OVER THE
GREAT LKS...WHICH IS LARGELY A FUNCTION OF THE LLVL MOISTURE AND
RESULTANT FOG. ADDED PATCHY FOG NEAR LK MI FOR SAT/SUN AND ALSO LK
SUPERIOR JUST OFF SHORE FROM UPPER MI WITH THE SSE FLOW. MAY NEED TO
EXTEND IT THROUGH THE EXTENDED PERIOD IF LLVL MOISTURE PANS
OUT...WHICH WOULD PROBABLY PRODUCE SOME DENSE PERIODS.
TEMPS REMAIN WELL ABOVE NORMAL THROUGH THE FIRST PART OF NEXT
WEEK...WITH HIGHS IN THE 60S AWAY FROM THE SOUTHERLY WINDS OF LK
MI. LOW CLOUDS/FOG COULD CAUSE ISSUES WITH THESE TEMPS AND ONLY
CHANGES MADE TO THE MODEL CONSENSUS WAS TO WARM UP DOWNSLOPE AREAS
NEAR LK SUPERIOR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 720 AM EDT WED MAR 14 2012
WITH DAYTIME HEATING...EXPECT STRONG LLVL WINDS JUST ABV SFC
RADIATION INVRN THAT IS CAUSING SOME LLWS AT CMX/IWD TO MIX OUT THIS
MRNG AND RESULT IN SOME GUSTY WINDS...ESPECIALLY AT THE MORE EXPOSED
SAW/IWD LOCATIONS. VFR CONDITIONS WILL DOMINATE WITH VERY DRY
AIRMASS IN PLACE. A COLD FNT WILL ARRIVE LATE TDAY OVER WRN UP MI...
BRINGING A WSHFT BY 00Z AT IWD/CMX AND LATER IN THE EVNG AT SAW.
THERE ARE QUESTIONS AS TO HOW MUCH LLVL MSTR WILL TRAIL THE FNT AND
WHETHER LO CLDS WILL DEVELOP TNGT AT THE TAF SITES IN ITS WAKE. THE
BEST CHC FOR LOWER CIGS WITH UPSLOPE NW VEERING NE WIND LOOKS TO BE
AT SAW...WHICH WL BE FARTHEST FROM CORE OF DRY AIR PASSING WITH SFC
HI PRES ENEWD FROM MINNESOTA INTO ONTARIO.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 413 AM EDT WED MAR 14 2012
EXPECT WINDS TO BE GENERALLY UNDER 25 KTS INTO THIS WEEKEND AS A
RELATIVELY WEAK PRES GRADIENT DOMINATES. ALTHOUGH A SHARPER PRES
GRADIENT/STRONGER S FLOW WILL DEVELOP OVER THE WEEKEND...THE
UNSEASONABLY WARM AIR OVER THE UPPER GREAT LAKES WILL ALSO RESULT IN
PERSISTENT MARINE LAYER/STRONG STABILITY OVER THE LAKE...HELPING TO
KEEP SURFACE WINDS ON THE LIGHTER SIDE. AT SOME POINT...FOG MAY
BECOME AN ISSUE...BUT EXPECTED DRY WEATHER THRU THE WEEKEND WILL
LIMIT THIS POTENTIAL.
&&
.HYDROLOGY...
ISSUED AT 413 AM EDT WED MAR 14 2012
WARM TEMPERATURES OVER THE LAST SEVERAL DAYS...ALONG WITH RAIN OF
0.10 TO MORE THAN 0.5 INCH ON MON HAS LED TO INCREASED SNOWMELT/
RUNOFF. THIS RUNOFF HAS PRODUCED SOME RISE IN LEVELS OF RIVERS IN
UPR MI OVER THE LAST COUPLE OF DAYS. TEMPS HAVE FALLEN BLO 32 AT
MANY SPOTS OVER THE CWA EARLY THIS MRNG...BRINGING A TEMPORARY
RESPITE TO THE STEADY MELTING.
ABOVE NORMAL TEMPERATURES INTO NEXT WEEK WILL CONTINUE TO MELT THE
SNOW PACK AND LEAD TO FURTHER INCREASES IN RIVER AND STREAM LEVELS.
DESPITE THE BREAK EARLY THIS MRNG...A PERIOD OF RAPID MELTING WILL
OCCUR TODAY...AS TEMPERATURES RISE AOA 70 DEGREES OVER THE WEST AND
DEWPOINTS RISE INTO THE 40S LATER IN THE DAY. ALTHOUGH A COOLER
AIRMASS WILL ARRIVE ON THU...EXPECT SOME OF THE RIVERS ACROSS THE
AREA TO EXCEED THEIR BANKS BY THE END OF THIS WEEK. PERSONS LIVING
NEAR RIVERS AND STREAMS SHOULD MONITOR THE LATEST RIVER CONDITIONS
AND USE CAUTION IF WALKING ALONG RIVER BANKS...ESPECIALLY THE
CHOCOLAY RIVER...TRAP ROCK RIVER...AND THE STURGEON RIVER IN WESTERN
UPPER MICHIGAN.
THERE WAS AN APPARENT ICE JAM ON THE ONTONAGON RIVER NEAR ROCKLAND
MON EVENING. THIS CAUSED THE RIVER LEVELS TO RISE 4FT BEFORE IT
BROKE FREE. WILL NEED TO MONITOR CONDITIONS ALONG THE ONTONAGON RIVER
OVER THE NEXT DAY OR TWO...AS THE NUMEROUS BENDS COULD CAUSE THE ICE
TO FORM ANOTHER JAM. IN ADDITION...ICE WAS REPORTED ON THE FORD RIVER
AT HYDE AND THE MOUTH AT LK MI. DEPENDING ON THE BREAKUP OF THE
ICE...THERE IS A POTENTIAL FOR ICE JAMS THIS WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...KC
HYDROLOGY...KC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
642 AM CDT WED MAR 14 2012
.AVIATION...
12Z TAFS FOR KOFK...KLNK AND KOMA.
GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH THURSDAY MORNING.
LOW LEVEL CLOUDS NEAR FL020 WERE DEVELOPING ACROSS NORTHEAST
KANSAS...AND ARE EXPECTED TO SPREAD NORTHEAST THROUGH SOUTHEAST
NEBRASKA. OCCASIONAL MVFR CIGS COULD SKIRT THE KOMA AREA FOR A FEW
HOURS BETWEEN 12Z AND 18Z...BUT WILL LIKELY STAY JUST TO THE
SOUTHEAST. OTHERWISE SCATTERED TO BROKEN HIGH CLOUDS ARE FORECAST.
A SOUTH TO SOUTHWEST WINDS AT ALL TAF SITES EARLY WILL GRADUALLY
BECOME NORTHERLY AS A COLD FRONT DRIFTS THROUGH EASTERN NEBRASKA
DURING THE DAY.
DERGAN
&&
.PREV DISCUSSION... /ISSUED 359 AM CDT WED MAR 14 2012/
DISCUSSION...
FOCUS CENTERS AROUND RECORD/NEAR RECORD TEMPS AND CHANCES FOR
TSTMS NEXT FEW DAYS.
WEAK UPPER LEVEL RIDGE HAS MOVED WELL EAST OF THE REGION LEAVING
CENTRAL PLAINS IN WEAK SOUTHWESTERLY FLOW ALOFT FOR NEXT FEW DAYS.
SEVERAL WEAK SHORTWAVES ARE EMBEDDED WITHIN THIS SOUTHWEST FLOW
AND WILL COMPLICATE THE FORECAST INTO THE WEEKEND. MODEL AGREEMENT
ON STRENGTH OF THESE SHORTWAVES IS POOR...LEADING TO LOW
FORECASTER CONFIDENCE ON TSTM CHANCES INTO THE WEEKEND.
TEMPERATURES REMAIN QUITE WARM THIS MORNING AND WILL BE CLOSE TO
RECORD MAX MINS. STRONG MOIST ADVECTION CONTINUES WITH UPSTREAM
DEWPOINTS IN THE UPPER 50S. PATCHY STRATUS IS BEGINNING TO DEVELOP
ACROSS SRN KS AND SO WILL HAVE TO KEEP A CLOSE EYE ON HOW
WIDESPREAD THIS BECOMES THROUGH THE MORNING HOURS. 06Z NAM AND
LATEST HRRR ARE TOO QUICK ON SPREADING THIS STRATUS INTO OUR SERN
COUNTIES SO DO HAVE RESERVATIONS ABOUT ADDING CLOUDS TO THE
SOUTHEAST. SURFACE COLD FRONT CURRENTLY EXTENDS ACROSS CNTRL ND
AND INTO NWRN SD AND WILL QUICKLY PUSH SEWD THROUGH THE MORNING
HOURS AND ENTER INTO THE NWRN CWA BY LATE MORNING. WE SHOULD BE
ABLE TO MIX OUT AHEAD OF THE BOUNDARY WITH THE FRONT COMING THRU A
MAJORITY OF THE CWA BY PEAK HEATING. HAVE FOLLOWED MORE CLOSELY TO
PREVIOUS FORECAST HIGHS TODAY RATHER THAN JUMP ONTO NEW MET
GUIDANCE WHICH IS ABOUT 10 DEGREES COOLER. WE ARE STILL
FORECASTING NEAR RECORD HIGHS AT LNK AND OMA. DID REMOVE CHANCE OF
TSTMS TONIGHT AS FORCING IS MINIMAL AND INSTABILITY AXIS IS FAR TO
OUR SOUTH. SFC FRONT WASHES OUT OVER THE FORECAST AREA THIS
EVENING.
SOUTHERLY LOW LEVEL FLOW RETURNS ON THURSDAY WITH SFC DEWPOINTS
RETURNING INTO THE UPPER 50S TO NEAR 60 IN OUR SOUTH BY THURSDAY
AFTERNOON. DRY LINE/SFC TROF IS FORECAST TO REMAIN JUST TO OUR WEST
AND AS A WEAK UPPER LEVEL SHORTWAVE APPROACHES THE REGION...TSTMS
COULD POSSIBLY DEVELOP BY LATE AFTERNOON. SWODY2 HAS LARGE AREA OF
SLIGHT RISK OVER THE CWA. WL CONCENTRATE TSTM CHANCES MAINLY IN THE
SOUTH WHERE RICH THETA-E AIR RESIDES. VEERED LOW LEVEL JET AROUND
30KTS WL AID IN LLVL CONVERGENCE INTO THE EVENING HOURS. CONFIDENCE
IS LOW ON THE TSTM CHANCES SO THEREFORE HAVE ONLY GONE WITH A SLIGHT
CHANCE POP.
SOUTHWESTERLY FLOW ALOFT CONTINUES INTO THE WEEKEND WITH RICH
BOUNDARY LAYER MOISTURE REMAINING IN PLACE. SHORTWAVE IS
FORECAST TO PASS OVER THE REGION WITH LITTLE CONFIDENCE ONCE
AGAIN ON STRENGTH. WL NOT GET TOO CARRIED AWAY ADDING TSTMS OVER
THE ENTIRE FORECAST AREA JUST YET BUT DO HAVE LOW POPS IN THE SOUTH
ON FRIDAY NIGHT AS NOSE OF VEERED 50KT LOW LEVEL JET CREEPS INTO
SERN NEB WHERE INSTABILITY REMAINS MODERATE.
IN THE EXTENDED...LARGE WESTERN TROF AXIS IS FORECAST TO SLOWLY
PROGRESS INTO THE FOUR CORNERS REGION BY MONDAY AND BECOME SLIGHTLY
NEGATIVELY TILTED BY TUESDAY AS IT MOVES TOWARD THE CNTRL PLAINS.
CHANCE POPS CONTINUE FOR MUCH OF NEXT WEEK AHEAD OF THIS LARGE
TROUGH.
KERN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
554 AM CDT WED MAR 14 2012
.AVIATION...12Z TAF. A TROUGH OF LOW PRESSURE WILL MOVE THROUGH
THE AREA THIS MORNING AND TURN WINDS TO THE WEST...AND EVENTUALLY
TO THE NORTHWEST. WINDS WILL BE LIGHTER TODAY WITH SPEEDS AROUND
10 KNOTS OR LESS. VFR CONDITIONS ARE EXPECTED WITH SOME CIRRUS
STREAMING ACROSS THE AREA.
&&
.PREV DISCUSSION... /ISSUED 525 AM CDT WED MAR 14 2012/
SHORT TERM...THROUGH FRIDAY NIGHT. PRIMARY FORECAST CHALLENGE IS
DETERMINING WHEN...AND EVEN TO SOME EXTENT IF...LEGITIMATE
SHOWER/THUNDERSTORM DEVELOPMENT WILL TAKE PLACE WITHIN THE CWA AS
THE AIRMASS DESTABILIZES OVER THE NEXT FEW DAYS.
09Z OBJECTIVE SURFACE ANALYSIS REVEALS A WEAK TROUGH AXIS CUTTING
ACROSS THE HEART OF THE CWA FROM NORTHEAST TO SOUTHWEST...TRAILING
WELL SOUTH OF A STRONG...PARENT SURFACE LOW IN CANADA. TO THE
SOUTHEAST OF THIS TROUGH AXIS...AN INCREDIBLY BALMY NIGHT HAS BEEN
OBSERVED WITH TEMPS EVEN AT THIS HOUR RIGHT AROUND 60 IN THE
SOUTHEAST CWA...ACCOMPANIED BY SOUTHERLY BREEZES GUSTING TO AROUND
20 MPH OR HIGHER. FOR THE MAJORITY OF THE CWA HOWEVER...BREEZES
ARE LIGHTER WITH A LIGHT NORTHWEST COMPONENT STARTING TO WORK INTO
NORTHWEST ZONES...WHERE TEMPS ARE NOTABLY COOLER IN THE 40S AND
EVEN SOME UPPER 30S. ALOFT...11-3.9 MICRON AND WATER VAPOR
SATELLITE IMAGERY REVEAL EXPANSIVE WEST-SOUTHWEST FLOW ACROSS THE
CENTRAL PLAINS...WELL TO THE SOUTH OF A POWERFUL NEGATIVELY TILTED
SHORTWAVE GRINDING ACROSS SOUTH CENTRAL CANADA. WHILE SKIES ARE
GENERALLY CLEAR OVER THE CWA...A PLUME OF THIN CIRRUS IS SKIRTING
ACROSS NORTHERN COUNTIES...WHILE A FEW COUNTIES SOUTHEAST OF THE
CWA...SOME LOW STRATUS IS STARTING TO EXPAND ACROSS SOUTH CENTRAL
AND EASTERN KANSAS.
STARTING OFF RIGHT AWAY THIS MORNING...WILL RUN WITH THE
ASSUMPTION THAT ANY LOW STRATUS DEVELOPING TO OUR SOUTHEAST WILL
REMAIN JUST SOUTHEAST OF THE CWA...ALTHOUGH IT COULD BE A FAIRLY
CLOSE CALL PER 925MB RH PROGS FROM THE 06Z NAM. HRRR HAS ALSO BEEN
SUGGESTING SOME PRE-DAWN FOG DEVELOPMENT IN SOUTHEAST ZONES...BUT
UNLESS WINDS REALLY DROP OFF NOT ANTICIPATING ANYTHING MORE THAN
MAYBE A LIGHT HAZE NOT WORTH MENTIONING IN THE FORECAST AT THIS
POINT. GETTING ON WITH THE BULK OF THE DAY...ANOTHER IN A
REMARKABLE STRING OF DAYS WITH TEMPS RUNNING AROUND 30 DEGREES
ABOVE NORMAL IS IN STORE...AS THE LOW LEVEL TEMP PROFILE IS
ESSENTIALLY UNCHANGED FROM YESTERDAY. ONLY MAIN DIFFERENCE FROM
YESTERDAY IS THAT WINDS WILL BE LIGHTER AND TRANSITION TO MORE OF
A NORTHWEST/NORTHERLY COMPONENT AS THE AFOREMENTIONED TROUGH
AXIS/WEAK COLD FRONT SLIDES THROUGH. 06Z RUC SUGGESTS NORTHERLY
BREEZES COULD GET SLIGHTLY BREEZY FOR A FEW HOURS MAINLY LATER
THIS MORNING...BUT SPEEDS ARE ANTICIPATED TO REMAIN SHORT OF RED
FLAG WARNING CRITERIA. FOR MORE FIRE WEATHER DISCUSSION...PLEASE
SEE SEPARATE SECTION BELOW. GETTING BACK TO HIGH TEMPS...CHANGED
LITTLE FROM PREVIOUS WITH WIDESPREAD UPPER 70S/NEAR 80 IN NEB
ZONES...AND LOW-MID 80S IN KS.
THIS EVENING/TONIGHT...THE LARGE SCALE PATTERN ALOFT REMAINS
LARGELY UNCHANGED WITH THE BROAD WEST-SOUTHWEST FLOW...BUT AT
LEAST KS PORTIONS OF THE CWA SHOULD FINALLY START REALIZING SOME
LEGITIMATE ELEVATED INSTABILITY MAINLY AFTER MIDNIGHT WITH THE
06Z NAM/GFS PROGGING MUCAPE IN THE 850-700MB LAYER INCREASING TO
BETWEEN 500-1000 J/KG AFTER MIDNIGHT. THIS IS IN RESPONSE TO
MODEST THETA-E ADVECTION SPARKED BY A SUBTLE SHORTWAVE
TRANSITIONING THROUGH THE FLOW. COMPARED TO 24 HOURS AGO...MODELS
IN GENERAL ARE MUCH LESS BULLISH ON INITIATING CONVECTION...WITH
THE NAM NOW DRY AND GFS FOCUSING OVERNIGHT CONVECTION SOUTH OF THE
CWA. 00Z 4KM WRF-NMM IS ALSO DRY. ALL THAT BEING SAID...TRIMMED
SLIGHT CHANCE FOR STORMS OUT OF NEB ZONES BUT KEPT A TOKEN MENTION
GOING ACROSS KS...AS WOULD NOT BE SURPRISED TO SEE A ROGUE STORM
POP IN THE FAVORABLE THETA-E ADVECTION REGIME. STILL...WOULD NOT
BE SURPRISED IF DAY SHIFT OPTS TO PULL THE SLIGHT POP ALTOGETHER
DEPENDING ON WHAT NEW MODEL SUITE HAS TO OFFER. FOR LOW TEMPS
TONIGHT...KEPT SIMILAR TO PREVIOUS OVERALL...BUT NUDGED DOWN
SOUTHEAST SLIGHTLY AS LIGHT/VARIABLE WIND REGIME SHOULD ALLOW FOR
MORE OF A DROP. THUS HAVE A RANGE FROM UPPER 30S FAR NORTHWEST TO
LOW 50S FAR SOUTHEAST.
THURSDAY...SAME OLD STORY ALOFT WITH THE WEST-SOUTHWEST FLOW...BUT
DOWN LOW...INSTABILITY REALLY RAMPS UP DURING THE AFTERNOON TO THE
EAST OF ANOTHER FAIRLY SUBTLE SURFACE TROUGH AXIS DROPPING IN FROM
THE NORTHWEST. ALTHOUGH THE NAM CAPE VALUES MAY BE OVERDONE...EVEN
THE 06 GFS BRINGS 0-1KM MLCAPE INTO THE 1000-1500 J/KG RANGE
DURING PEAK HEATING IN EASTERN ZONES...WITH FAIRLY WEAK CAPPING
AND AROUND 30KT OF DEEP LAYER SHEAR. THE ULTIMATE QUESTION IS
WHETHER SUBTLE FORCING WILL BE STRONG ENOUGH TO FIRE CONVECTION.
MODELS CONTINUE TO THROW VARIOUS QPF SOLUTIONS...WITH THE 06Z NAM
LESS AGGRESSIVE THAN ITS 00Z RUN FOR THURSDAY AFTERNOON...BUT
STILL SHOWING CONVECTIVE POTENTIAL IN THE EVENING MAINLY EAST OF
HWY 281. THE 00Z ECMWF KEEPS ALL CONVECTION SEVERAL COUNTIES EAST
OF THE CWA DURING THIS TIME. ALL THINGS CONSIDERED...CONFIDENCE IS
QUITE LOW WHETHER CONVECTION WILL FIRE...BUT AGREE WITH SPC DAY 2
OUTLOOK THAT ANYTHING THAT DOES GO COULD BECOME STRONG/SEVERE AND
YIELD HAIL/STRONG WINDS. THUS INTRODUCED LOW CONFIDENCE SLIGHT
CHANCE POPS MAINLY ACROSS EASTERN ZONES THURS AFTERNOON INTO
EVENING...WITH NOTHING AFTER 06Z AS ANY POTENTIAL STORMS EXPECTED
TO BE OFF TO THE EAST BY THEN. GETTING BACK TO THE DAYTIME
HOURS...ESSENTIALLY COOKIE CUTTER HIGH TEMPS CONTINUE...WITH
WIDESPREAD UPPER 70S TO NEAR 80.
FRIDAY INTO FRIDAY NIGHT...UPPER PATTERN STARTS TO SHIFT MORE
SOUTHWESTERLY AS LARGE SCALE TROUGH BEGINS TO IMPINGE ON WEST
COAST. SOUTHERLY BREEZES WILL START PICKING UP DURING THE
DAY...AND BOOSTED SPEEDS NOTICEABLY IN GRIDS...WITH SUSTAINED
SPEEDS AT LEAST AROUND 20 MPH ANTICIPATED. ALTHOUGH AIR MASS WILL
CONTINUE TO MOISTEN WITH WIDESPREAD 50+ DEWPOINTS PROGGED IN
EASTERN COUNTIES...AGAIN HAVE HIGH TEMPS RIGHT AROUND 80 MOST
AREAS. STRONGLY CONSIDERED ADDING ANOTHER SLIGHT CHANCE OF
THUNDERSTORMS DURING THIS TIME FRAME AS VARIOUS MODELS DEPICT AN
EMBEDDED MID LEVEL WAVE SPARKING CONVECTION IN OR NEAR THE
CWA...ESPECIALLY THE GFS ON FRIDAY NIGHT WITHIN A STRONG LOW LEVEL
JET AXIS AND MUCAPE IN EXCESS OF 1000 J/KG. CERTAINLY IF ANY
STORMS DO MANAGE TO FIRE FRIDAY AFTERNOON INTO THE NIGHT...STRONG
TO SEVERE POTENTIAL IS THERE PER SPC DAY 3 OUTLOOK...BUT WITH THIS
STILL BEING 5-6 PERIODS OUT AND MODELS STRUGGLING WITH RUN TO RUN
CONSISTENCY OF FORCING/TIMING OF QUICK MOVING WAVES...WILL OPT TO
OMIT THUNDERSTORM MENTION FOR NOW. WOULD RATHER PLAY IT
CONSERVATIVE AND NOT LITTER THE FORECAST WITH MULTIPLE SLIGHT
CHANCES OF STORMS UNTIL CONFIDENCE BECOMES CLEARER AT THIS RANGE.
AS MENTIONED LAST NIGHT...WILL NEED TO ALSO MONITOR NEXT FEW
NIGHTS FOR POSSIBLE FOG DEVELOPMENT MAINLY IN SOUTHEAST ZONES
WHERE BETTER LOW LEVEL MOISTURE WILL RESIDE...BUT CONFIDENCE IS
STILL TOO LOW TO INSERT A FORMAL FOG MENTION INTO FORECAST.
LONG TERM...SATURDAY THROUGH TUESDAY. MAIN FORECAST CONCERNS WILL
BE CHANCES FOR THUNDERSTORMS MONDAY THROUGH TUESDAY AND TEMPERATURES
THROUGH THE PERIOD.
SOUTHWESTERLY FLOW ALOFT WILL CONTINUE SATURDAY THROUGH SUNDAY
NIGHT. A FEW WAVES MOVE THROUGH THE FLOW BUT THE FORECAST SHOULD
REMAIN DRY. THE SURFACE GRADIENT TIGHTENS THROUGH THE PERIOD AND
EXPECT THAT WINDS WILL BE FAIRLY STRONG OVER THE WEEKEND.
TEMPERATURES DURING THIS PERIOD REMAIN VERY WARM WITH READINGS 25 TO
30 DEGREES ABOVE NORMAL.
THE UPPER LOW IN THE SOUTHWEST CONUS STARTS TO MOVE TO THE EAST
SUNDAY NIGHT AND AFFECTS THE AREA MONDAY THROUGH TUESDAY. MODELS
HAVE QUITE A FEW INCONSISTENCIES BOTH BETWEEN MODELS AND EVEN RUN TO
RUN WITHIN THE MODEL. DESPITE THESE DIFFERENCES THERE ARE SOME
SIMILARITIES AS WELL. THERE IS A LONG TERM FETCH OF WARM MOIST AIR
FROM THE GULF INTO THE EASTERN PART OF THE REGION. AS THE LOW GETS
CLOSER THE MOISTURE GETS PULLED INTO THE CIRCULATION AND THERE IS A
CHANCE FOR THUNDERSTORMS. THE MODEL DEPICTION OF PRECIPITATION IS
FAIRLY SIMILAR CONSIDERING ALL THE DIFFERENCES. WILL KEEP CHANCES
FOR THUNDERSTORMS ACROSS THE AREA MONDAY THROUGH TUESDAY.
TEMPERATURES AT 850MB ARE SEVERAL DEGREES COOLER THAN DURING THE
WEEKEND SO EXPECT THAT TEMPERATURES WILL BE A BIT COOLER...BUT STILL
SHOULD BE ABOVE NORMAL.
FIRE WEATHER...ALTHOUGH WINDS TODAY SHOULD FALL WELL SHORT OF
OFFICIAL RED FLAG WARNING CRITERIA OF SUSTAINED 20 MPH/GUST 25
MPH...RELATIVE HUMIDITY VALUES ARE YET AGAIN PROGGED TO SLIP AT
LEAST DOWN INTO THE 15-20 PERCENT RANGE FOR MANY AREAS THIS
AFTERNOON...ESPECIALLY WEST OF THE HIGHWAY 281 CORRIDOR. AS A
RESULT...THE GRASSLAND FIRE DANGER PRODUCT...RFDGID...HAS DECLARED
EXTREME FIRE DANGER ACROSS THESE CENTRAL AND WESTERN AREAS THIS
AFTERNOON...WITH CATEGORICAL VERY HIGH FIRE DANGER IN COUNTIES TO
THE EAST. WITH INCREASING LOW LEVEL MOISTURE OVER THE NEXT SEVERAL
DAYS...TODAY SHOULD BE THE LAST DAY FOR AWHILE THAT WILL FEATURE
WIDESPREAD RH VALUES BELOW 20 PERCENT. GIVEN THE INCREDIBLE WARM
PATTERN WE ARE IN...THE AREA CAN CERTAINLY USE SOME WIDESPREAD
RAINFALL TO QUELL THE FIRE THREAT...ALTHOUGH FOR MUCH OF THE CWA
THAT MAY HAVE TO WAIT UNTIL AT LEAST EARLY NEXT WEEK WHEN THE
LARGE SCALE TROUGH MOVES IN.
CLIMATE...GONNA BE ANOTHER DAY OF AT LEAST NEARING RECORD HIGHS
IN THE TRI-CITIES. ALTHOUGH OFFICIAL FORECAST CURRENTLY KEEPS
READINGS JUST SHORT...THE HIGHS TO BREAK ARE ALL FROM WAY BACK IN
1935...AND CONSIST OF 81 IN GRAND ISLAND...83 IN HASTINGS AND 82
IN KEARNEY. THIS DOES NOT LOOK TO BE THE LAST DAY OF THE NEXT
SEVERAL IN WHICH RECORD HIGHS COULD BE IN JEOPARDY OF
FALLING...BUT THOSE FOR THURSDAY DO APPEAR LEGITIMATELY OUT OF
REACH AS THINGS STAND.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
525 AM CDT WED MAR 14 2012
.SHORT TERM...THROUGH FRIDAY NIGHT. PRIMARY FORECAST CHALLENGE IS
DETERMINING WHEN...AND EVEN TO SOME EXTENT IF...LEGITIMATE
SHOWER/THUNDERSTORM DEVELOPMENT WILL TAKE PLACE WITHIN THE CWA AS
THE AIRMASS DESTABILIZES OVER THE NEXT FEW DAYS.
09Z OBJECTIVE SURFACE ANALYSIS REVEALS A WEAK TROUGH AXIS CUTTING
ACROSS THE HEART OF THE CWA FROM NORTHEAST TO SOUTHWEST...TRAILING
WELL SOUTH OF A STRONG...PARENT SURFACE LOW IN CANADA. TO THE
SOUTHEAST OF THIS TROUGH AXIS...AN INCREDIBLY BALMY NIGHT HAS BEEN
OBSERVED WITH TEMPS EVEN AT THIS HOUR RIGHT AROUND 60 IN THE
SOUTHEAST CWA...ACCOMPANIED BY SOUTHERLY BREEZES GUSTING TO AROUND
20 MPH OR HIGHER. FOR THE MAJORITY OF THE CWA HOWEVER...BREEZES
ARE LIGHTER WITH A LIGHT NORTHWEST COMPONENT STARTING TO WORK INTO
NORTHWEST ZONES...WHERE TEMPS ARE NOTABLY COOLER IN THE 40S AND
EVEN SOME UPPER 30S. ALOFT...11-3.9 MICRON AND WATER VAPOR
SATELLITE IMAGERY REVEAL EXPANSIVE WEST-SOUTHWEST FLOW ACROSS THE
CENTRAL PLAINS...WELL TO THE SOUTH OF A POWERFUL NEGATIVELY TILTED
SHORTWAVE GRINDING ACROSS SOUTH CENTRAL CANADA. WHILE SKIES ARE
GENERALLY CLEAR OVER THE CWA...A PLUME OF THIN CIRRUS IS SKIRTING
ACROSS NORTHERN COUNTIES...WHILE A FEW COUNTIES SOUTHEAST OF THE
CWA...SOME LOW STRATUS IS STARTING TO EXPAND ACROSS SOUTH CENTRAL
AND EASTERN KANSAS.
STARTING OFF RIGHT AWAY THIS MORNING...WILL RUN WITH THE
ASSUMPTION THAT ANY LOW STRATUS DEVELOPING TO OUR SOUTHEAST WILL
REMAIN JUST SOUTHEAST OF THE CWA...ALTHOUGH IT COULD BE A FAIRLY
CLOSE CALL PER 925MB RH PROGS FROM THE 06Z NAM. HRRR HAS ALSO BEEN
SUGGESTING SOME PRE-DAWN FOG DEVELOPMENT IN SOUTHEAST ZONES...BUT
UNLESS WINDS REALLY DROP OFF NOT ANTICIPATING ANYTHING MORE THAN
MAYBE A LIGHT HAZE NOT WORTH MENTIONING IN THE FORECAST AT THIS
POINT. GETTING ON WITH THE BULK OF THE DAY...ANOTHER IN A
REMARKABLE STRING OF DAYS WITH TEMPS RUNNING AROUND 30 DEGREES
ABOVE NORMAL IS IN STORE...AS THE LOW LEVEL TEMP PROFILE IS
ESSENTIALLY UNCHANGED FROM YESTERDAY. ONLY MAIN DIFFERENCE FROM
YESTERDAY IS THAT WINDS WILL BE LIGHTER AND TRANSITION TO MORE OF
A NORTHWEST/NORTHERLY COMPONENT AS THE AFOREMENTIONED TROUGH
AXIS/WEAK COLD FRONT SLIDES THROUGH. 06Z RUC SUGGESTS NORTHERLY
BREEZES COULD GET SLIGHTLY BREEZY FOR A FEW HOURS MAINLY LATER
THIS MORNING...BUT SPEEDS ARE ANTICIPATED TO REMAIN SHORT OF RED
FLAG WARNING CRITERIA. FOR MORE FIRE WEATHER DISCUSSION...PLEASE
SEE SEPARATE SECTION BELOW. GETTING BACK TO HIGH TEMPS...CHANGED
LITTLE FROM PREVIOUS WITH WIDESPREAD UPPER 70S/NEAR 80 IN NEB
ZONES...AND LOW-MID 80S IN KS.
THIS EVENING/TONIGHT...THE LARGE SCALE PATTERN ALOFT REMAINS
LARGELY UNCHANGED WITH THE BROAD WEST-SOUTHWEST FLOW...BUT AT
LEAST KS PORTIONS OF THE CWA SHOULD FINALLY START REALIZING SOME
LEGITIMATE ELEVATED INSTABILITY MAINLY AFTER MIDNIGHT WITH THE
06Z NAM/GFS PROGGING MUCAPE IN THE 850-700MB LAYER INCREASING TO
BETWEEN 500-1000 J/KG AFTER MIDNIGHT. THIS IS IN RESPONSE TO
MODEST THETA-E ADVECTION SPARKED BY A SUBTLE SHORTWAVE
TRANSITIONING THROUGH THE FLOW. COMPARED TO 24 HOURS AGO...MODELS
IN GENERAL ARE MUCH LESS BULLISH ON INITIATING CONVECTION...WITH
THE NAM NOW DRY AND GFS FOCUSING OVERNIGHT CONVECTION SOUTH OF THE
CWA. 00Z 4KM WRF-NMM IS ALSO DRY. ALL THAT BEING SAID...TRIMMED
SLIGHT CHANCE FOR STORMS OUT OF NEB ZONES BUT KEPT A TOKEN MENTION
GOING ACROSS KS...AS WOULD NOT BE SURPRISED TO SEE A ROGUE STORM
POP IN THE FAVORABLE THETA-E ADVECTION REGIME. STILL...WOULD NOT
BE SURPRISED IF DAY SHIFT OPTS TO PULL THE SLIGHT POP ALTOGETHER
DEPENDING ON WHAT NEW MODEL SUITE HAS TO OFFER. FOR LOW TEMPS
TONIGHT...KEPT SIMILAR TO PREVIOUS OVERALL...BUT NUDGED DOWN
SOUTHEAST SLIGHTLY AS LIGHT/VARIABLE WIND REGIME SHOULD ALLOW FOR
MORE OF A DROP. THUS HAVE A RANGE FROM UPPER 30S FAR NORTHWEST TO
LOW 50S FAR SOUTHEAST.
THURSDAY...SAME OLD STORY ALOFT WITH THE WEST-SOUTHWEST FLOW...BUT
DOWN LOW...INSTABILITY REALLY RAMPS UP DURING THE AFTERNOON TO THE
EAST OF ANOTHER FAIRLY SUBTLE SURFACE TROUGH AXIS DROPPING IN FROM
THE NORTHWEST. ALTHOUGH THE NAM CAPE VALUES MAY BE OVERDONE...EVEN
THE 06 GFS BRINGS 0-1KM MLCAPE INTO THE 1000-1500 J/KG RANGE
DURING PEAK HEATING IN EASTERN ZONES...WITH FAIRLY WEAK CAPPING
AND AROUND 30KT OF DEEP LAYER SHEAR. THE ULTIMATE QUESTION IS
WHETHER SUBTLE FORCING WILL BE STRONG ENOUGH TO FIRE CONVECTION.
MODELS CONTINUE TO THROW VARIOUS QPF SOLUTIONS...WITH THE 06Z NAM
LESS AGGRESSIVE THAN ITS 00Z RUN FOR THURSDAY AFTERNOON...BUT
STILL SHOWING CONVECTIVE POTENTIAL IN THE EVENING MAINLY EAST OF
HWY 281. THE 00Z ECMWF KEEPS ALL CONVECTION SEVERAL COUNTIES EAST
OF THE CWA DURING THIS TIME. ALL THINGS CONSIDERED...CONFIDENCE IS
QUITE LOW WHETHER CONVECTION WILL FIRE...BUT AGREE WITH SPC DAY 2
OUTLOOK THAT ANYTHING THAT DOES GO COULD BECOME STRONG/SEVERE AND
YIELD HAIL/STRONG WINDS. THUS INTRODUCED LOW CONFIDENCE SLIGHT
CHANCE POPS MAINLY ACROSS EASTERN ZONES THURS AFTERNOON INTO
EVENING...WITH NOTHING AFTER 06Z AS ANY POTENTIAL STORMS EXPECTED
TO BE OFF TO THE EAST BY THEN. GETTING BACK TO THE DAYTIME
HOURS...ESSENTIALLY COOKIE CUTTER HIGH TEMPS CONTINUE...WITH
WIDESPREAD UPPER 70S TO NEAR 80.
FRIDAY INTO FRIDAY NIGHT...UPPER PATTERN STARTS TO SHIFT MORE
SOUTHWESTERLY AS LARGE SCALE TROUGH BEGINS TO IMPINGE ON WEST
COAST. SOUTHERLY BREEZES WILL START PICKING UP DURING THE
DAY...AND BOOSTED SPEEDS NOTICEABLY IN GRIDS...WITH SUSTAINED
SPEEDS AT LEAST AROUND 20 MPH ANTICIPATED. ALTHOUGH AIR MASS WILL
CONTINUE TO MOISTEN WITH WIDESPREAD 50+ DEWPOINTS PROGGED IN
EASTERN COUNTIES...AGAIN HAVE HIGH TEMPS RIGHT AROUND 80 MOST
AREAS. STRONGLY CONSIDERED ADDING ANOTHER SLIGHT CHANCE OF
THUNDERSTORMS DURING THIS TIME FRAME AS VARIOUS MODELS DEPICT AN
EMBEDDED MID LEVEL WAVE SPARKING CONVECTION IN OR NEAR THE
CWA...ESPECIALLY THE GFS ON FRIDAY NIGHT WITHIN A STRONG LOW LEVEL
JET AXIS AND MUCAPE IN EXCESS OF 1000 J/KG. CERTAINLY IF ANY
STORMS DO MANAGE TO FIRE FRIDAY AFTERNOON INTO THE NIGHT...STRONG
TO SEVERE POTENTIAL IS THERE PER SPC DAY 3 OUTLOOK...BUT WITH THIS
STILL BEING 5-6 PERIODS OUT AND MODELS STRUGGLING WITH RUN TO RUN
CONSISTENCY OF FORCING/TIMING OF QUICK MOVING WAVES...WILL OPT TO
OMIT THUNDERSTORM MENTION FOR NOW. WOULD RATHER PLAY IT
CONSERVATIVE AND NOT LITTER THE FORECAST WITH MULTIPLE SLIGHT
CHANCES OF STORMS UNTIL CONFIDENCE BECOMES CLEARER AT THIS RANGE.
AS MENTIONED LAST NIGHT...WILL NEED TO ALSO MONITOR NEXT FEW
NIGHTS FOR POSSIBLE FOG DEVELOPMENT MAINLY IN SOUTHEAST ZONES
WHERE BETTER LOW LEVEL MOISTURE WILL RESIDE...BUT CONFIDENCE IS
STILL TOO LOW TO INSERT A FORMAL FOG MENTION INTO FORECAST.
.LONG TERM...SATURDAY THROUGH TUESDAY. MAIN FORECAST CONCERNS WILL
BE CHANCES FOR THUNDERSTORMS MONDAY THROUGH TUESDAY AND TEMPERATURES
THROUGH THE PERIOD.
SOUTHWESTERLY FLOW ALOFT WILL CONTINUE SATURDAY THROUGH SUNDAY
NIGHT. A FEW WAVES MOVE THROUGH THE FLOW BUT THE FORECAST SHOULD
REMAIN DRY. THE SURFACE GRADIENT TIGHTENS THROUGH THE PERIOD AND
EXPECT THAT WINDS WILL BE FAIRLY STRONG OVER THE WEEKEND.
TEMPERATURES DURING THIS PERIOD REMAIN VERY WARM WITH READINGS 25 TO
30 DEGREES ABOVE NORMAL.
THE UPPER LOW IN THE SOUTHWEST CONUS STARTS TO MOVE TO THE EAST
SUNDAY NIGHT AND AFFECTS THE AREA MONDAY THROUGH TUESDAY. MODELS
HAVE QUITE A FEW INCONSISTENCIES BOTH BETWEEN MODELS AND EVEN RUN TO
RUN WITHIN THE MODEL. DESPITE THESE DIFFERENCES THERE ARE SOME
SIMILARITIES AS WELL. THERE IS A LONG TERM FETCH OF WARM MOIST AIR
FROM THE GULF INTO THE EASTERN PART OF THE REGION. AS THE LOW GETS
CLOSER THE MOISTURE GETS PULLED INTO THE CIRCULATION AND THERE IS A
CHANCE FOR THUNDERSTORMS. THE MODEL DEPICTION OF PRECIPITATION IS
FAIRLY SIMILAR CONSIDERING ALL THE DIFFERENCES. WILL KEEP CHANCES
FOR THUNDERSTORMS ACROSS THE AREA MONDAY THROUGH TUESDAY.
TEMPERATURES AT 850MB ARE SEVERAL DEGREES COOLER THAN DURING THE
WEEKEND SO EXPECT THAT TEMPERATURES WILL BE A BIT COOLER...BUT STILL
SHOULD BE ABOVE NORMAL.
&&
.FIRE WEATHER...ALTHOUGH WINDS TODAY SHOULD FALL WELL SHORT OF
OFFICIAL RED FLAG WARNING CRITERIA OF SUSTAINED 20 MPH/GUST 25
MPH...RELATIVE HUMIDITY VALUES ARE YET AGAIN PROGGED TO SLIP AT
LEAST DOWN INTO THE 15-20 PERCENT RANGE FOR MANY AREAS THIS
AFTERNOON...ESPECIALLY WEST OF THE HIGHWAY 281 CORRIDOR. AS A
RESULT...THE GRASSLAND FIRE DANGER PRODUCT...RFDGID...HAS DECLARED
EXTREME FIRE DANGER ACROSS THESE CENTRAL AND WESTERN AREAS THIS
AFTERNOON...WITH CATEGORICAL VERY HIGH FIRE DANGER IN COUNTIES TO
THE EAST. WITH INCREASING LOW LEVEL MOISTURE OVER THE NEXT SEVERAL
DAYS...TODAY SHOULD BE THE LAST DAY FOR AWHILE THAT WILL FEATURE
WIDESPREAD RH VALUES BELOW 20 PERCENT. GIVEN THE INCREDIBLE WARM
PATTERN WE ARE IN...THE AREA CAN CERTAINLY USE SOME WIDESPREAD
RAINFALL TO QUELL THE FIRE THREAT...ALTHOUGH FOR MUCH OF THE CWA
THAT MAY HAVE TO WAIT UNTIL AT LEAST EARLY NEXT WEEK WHEN THE
LARGE SCALE TROUGH MOVES IN.
&&
.CLIMATE...GONNA BE ANOTHER DAY OF AT LEAST NEARING RECORD HIGHS
IN THE TRI-CITIES. ALTHOUGH OFFICIAL FORECAST CURRENTLY KEEPS
READINGS JUST SHORT...THE HIGHS TO BREAK ARE ALL FROM WAY BACK IN
1935...AND CONSIST OF 81 IN GRAND ISLAND...83 IN HASTINGS AND 82
IN KEARNEY. THIS DOES NOT LOOK TO BE THE LAST DAY OF THE NEXT
SEVERAL IN WHICH RECORD HIGHS COULD BE IN JEOPARDY OF
FALLING...BUT THOSE FOR THURSDAY DO APPEAR LEGITIMATELY OUT OF
REACH AS THINGS STAND.
&&
.PREV DISCUSSION... /ISSUED 1228 AM CDT WED MAR 14 2012/
AVIATION...06Z TAF. VFR CONDITIONS THROUGH THE PERIOD WITH ONLY
SOME CIRRUS MOVING ACROSS THE AREA DURING THE PERIOD. A TROUGH OF
LOW PRESSURE WILL MOVE THROUGH THE AREA DURING THE MORNING AND
TURN WINDS FROM SOUTH TO WEST AND EVENTUALLY NORTHWEST. WINDS WILL
BE FAIRLY LIGHT DURING THE PERIOD...AROUND 10 KNOTS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM/FIRE WEATHER/CLIMATE...PFANNKUCH
LONG TERM...JCB
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1040 AM CDT WED MAR 14 2012
.UPDATE...
TEMPERATURES THIS MORNING STARTED OUT PRETTY WARM FOR THIS TIME OF
YEAR WITH TEMPERATURES GENERALLY IN THE MID TO UPPER 60S. MOSTLY
CLOUDY SKIES WILL PREVAIL AGAIN TODAY AND THUS IT WILL AGAIN BE
TOUGH TO DESTABILIZE THE ATMOSPHERE THIS AFTERNOON.
HOWEVER...THERE ARE MORE BREAKS IN THE CLOUDS THIS MORNING WHICH
SHOULD YIELD SLIGHTLY WARMER LOW LEVEL TEMPS LATER TODAY. WITH
WEAK SHORTWAVES MOVING OVERHEAD AND A RELATIVELY STRONGER
SHORTWAVE EVIDENT NEAR THE EL PASO AREA...WILL INCLUDE A MENTION
FOR ISOLATED SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING.
ONCE AGAIN...IF A STORM CAN DEVELOP...IT WILL HAVE THE POTENTIAL TO
BECOME STRONG TO MARGINALLY SEVERE. OTHERWISE...ADJUSTED
TEMPERATURES DOWN A FEW DEGREES IN THE WEST WHERE THICK CLOUD
COVER SHOULD PERSIST FOR MUCH OF THE DAY.
82/JLD
&&
.AVIATION...
AFTER FURTHER CONSIDERATION...HAVE DECIDED NOT TO INCLUDE IFR
CONDITIONS IN A 12-15Z TEMPO GROUPING. THE WINDS ARE KEEPING THE
LOWER LEVELS SUFFICIENTLY MIXED TO KEEP FOG FROM DEVELOPING.
LIKEWISE...CEILINGS TO THE SOUTH REMAIN 1200-2500 FEET. THUS WILL
JUST LEAVE MVFR CEILINGS WITH NO VISIBILITY RESTRICTIONS THIS
MORNING.
.../PREVIOUS AVIATION DISCUSSION/...
GENERAL MVFR CEILINGS ARE EXPECTED TO PREVAIL THROUGH LATE
MORNING. HAVE LEFT A MENTION OF LIGHT FOG AND SOME HIGHER END IFR
CEILINGS IN THE TAFS FOR THE 12-15Z PERIOD...BUT WITH SURFACE
WINDS OF 10-15 KNOTS WILL LIKELY JUST RESULT IN LOWER END MVFR
CEILINGS. AS GREATER VERTICAL MIXING OCCURS LATER THIS
MORNING...EXPECT TO SEE CEILINGS RISE BACK TO THE VFR CATEGORY.
MVFR CEILINGS SHOULD RETURN AFTER 06-08Z THURSDAY.
58
&&
.PREV DISCUSSION... /ISSUED 336 AM CDT WED MAR 14 2012/
UPPER LEVEL RIDGING AND PERSISTENT SOUTHERLY LOW LEVEL FLOW WILL
LEAD TO ABOVE-NORMAL TEMPERATURES ACROSS NORTH AND CENTRAL TEXAS
FOR THE NEXT SEVERAL DAYS. WITH ABUNDANT LOW LEVEL MOISTURE IN
PLACE...THERE IS SOME CONCERN FOR FOG DEVELOPMENT DURING THE
EARLY MORNING HOURS AS TEMPERATURES APPROACH DEWPOINT READINGS. IN
FACT THE LAST FEW HRRR CYCLES HAVE HINTED AT LOWERING VISIBILITIES
ACROSS PARTS OF THE AREA PRIOR TO SUNRISE. HOWEVER...WITH WINDS
REMAINING MAINLY IN THE 10-15 MPH RANGE...FEEL WE WILL BE DEALING
MAINLY WITH LOW STRATUS AND SURFACE VISIBILITIES SHOULD REMAIN
OVERALL OKAY.
THE NEXT CHALLENGE WILL BE POPS FOR NOW THROUGH NEXT WEEK. THE
ATMOSPHERE IS UNSTABLE TODAY WITH MODEL FORECAST SB CAPE APPROACHING
1500 J/KG THIS AFTERNOON. NAM ALSO ERODES THE CAP ALMOST
COMPLETELY BY MID AFTERNOON...WHILE GFS HOLDS ONTO A GOOD AMOUNT
OF CIN. BELIEVE THAT WITH THE LACK OF A TRIGGER OR ANY UPPER LEVEL
SUPPORT...CONVECTION WILL HAVE A DIFFICULT TIME TODAY AND WILL
KEEP POPS BELOW 20 PERCENT WITHOUT ANY MENTION OF PRECIP IN THE
FORECAST. A SUBTLE SHORTWAVE WILL THEN PASS OVERHEAD DURING THE
DAY TOMORROW. FEEL THIS WILL ALLOW FOR THE DEVELOPMENT OF AT LEAST
ISOLATED STORMS. FOR NOW WILL LEAVE 20 POPS IN AREAWIDE AND REFINE
IF NEEDED LATER. THE UPPER DISTURBANCE SHIFTS EAST OF THE AREA
ALONG WITH THE ASSOCIATED PRECIPITATION THURSDAY NIGHT.
BY FRIDAY IT LOOKS LIKE THE RIDGE WILL BE TOO STRONG FOR
SIGNIFICANT RAIN CHANCES. ONE THING TO KEEP AN EYE ON WILL BE
DRYLINE DEVELOPMENT TO OUR NORTHWEST FRIDAY EVENING. AT THIS TIME
IT LOOKS LIKE ANY ACTIVITY THAT GETS GOING SHOULD DIMINISH BEFORE
REACHING THE AREA FRIDAY NIGHT. IF ANYTHING HOLDS TOGETHER AN
UPWARD ADJUSTMENT OF POPS MAY BE NEEDED LATE FRIDAY FOR THE
NORTHWESTERN COUNTIES.
THE UPPER RIDGE WILL BEGIN TO SLOWLY BREAK DOWN OVER THE WEEKEND
AS A LARGE SCALE UPPER TROUGH DEVELOPS OVER THE WESTERN CONUS.
ISOLATED SHOWERS AND STORMS WILL BE POSSIBLE BOTH SATURDAY AND
SUNDAY...ESPECIALLY DURING PEAK HEATING IN THE AFTERNOON. RAIN
CHANCES WILL THEN INCREASE SIGNIFICANTLY EARLY NEXT WEEK AS THE
UPPER TROUGH DIGS SOUTHEASTWARD TOWARDS THE REGION. GFS AND ECMWF
ARE SIMILAR WITH THE EVOLUTION OF THIS SYSTEM WITH ONLY MINOR
VARIATIONS IN THE TIMING. LARGE SCALE ASCENT AHEAD OF THE SYSTEM
SHOULD LEAD TO WIDESPREAD PRECIPITATION BY MONDAY OR MONDAY NIGHT.
MODELS ARE SHOWING NEGATIVE TILT...AND RESPECTIVE MODEL SOUNDINGS
AND HODOGRAPHS APPEAR CONDUCIVE FOR SEVERE WEATHER POTENTIAL. IT
IS STILL FAR TOO EARLY FOR ANY SPECIFICS BUT CERTAINLY WORTH
WATCHING AS THE FIRST DAYS OF SPRING DRAW NEAR. LONG RANGE
GUIDANCE THEN POINTS TOWARDS TEMPERATURES FINALLY RETURNING TO
NEAR-NORMAL AROUND THE MIDDLE OF NEXT WEEK AS THE AFOREMENTIONED
UPPER TROUGH SHOVES EAST OF THE AREA AND THE NEXT FRONT MOVES
THROUGH.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 77 66 78 66 77 / 10 10 20 10 10
WACO, TX 78 67 78 64 77 / 10 10 20 10 10
PARIS, TX 78 62 77 60 77 / 10 10 20 20 10
DENTON, TX 77 67 78 64 77 / 10 10 20 10 10
MCKINNEY, TX 77 67 77 65 77 / 10 10 20 20 10
DALLAS, TX 77 67 78 65 77 / 10 10 20 10 10
TERRELL, TX 78 66 78 64 77 / 10 10 20 20 10
CORSICANA, TX 78 65 78 64 78 / 10 10 20 10 10
TEMPLE, TX 78 66 78 64 77 / 10 10 20 10 10
MINERAL WELLS, TX 76 63 79 63 77 / 10 10 20 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
69/82
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
624 AM CDT WED MAR 14 2012
.AVIATION...
AFTER FURTHER CONSIDERATION...HAVE DECIDED NOT TO INCLUDE IFR
CONDITIONS IN A 12-15Z TEMPO GROUPING. THE WINDS ARE KEEPING THE
LOWER LEVELS SUFFICIENTLY MIXED TO KEEP FOG FROM DEVELOPING.
LIKEWISE...CEILINGS TO THE SOUTH REMAIN 1200-2500 FEET. THUS WILL
JUST LEAVE MVFR CEILINGS WITH NO VISIBILITY RESTRICTIONS THIS
MORNING.
588
.../PREVIOUS AVIATION DISCUSSION/...
GENERAL MVFR CEILINGS ARE EXPECTED TO PREVAIL THROUGH LATE
MORNING. HAVE LEFT A MENTION OF LIGHT FOG AND SOME HIGHER END IFR
CEILINGS IN THE TAFS FOR THE 12-15Z PERIOD...BUT WITH SURFACE
WINDS OF 10-15 KNOTS WILL LIKELY JUST RESULT IN LOWER END MVFR
CEILINGS. AS GREATER VERTICAL MIXING OCCURS LATER THIS
MORNING...EXPECT TO SEE CEILINGS RISE BACK TO THE VFR CATEGORY.
MVFR CEILINGS SHOULD RETURN AFTER 06-08Z THURSDAY.
58
58
&&
.PREV DISCUSSION... /ISSUED 336 AM CDT WED MAR 14 2012/
UPPER LEVEL RIDGING AND PERSISTENT SOUTHERLY LOW LEVEL FLOW WILL
LEAD TO ABOVE-NORMAL TEMPERATURES ACROSS NORTH AND CENTRAL TEXAS
FOR THE NEXT SEVERAL DAYS. WITH ABUNDANT LOW LEVEL MOISTURE IN
PLACE...THERE IS SOME CONCERN FOR FOG DEVELOPMENT DURING THE
EARLY MORNING HOURS AS TEMPERATURES APPROACH DEWPOINT READINGS. IN
FACT THE LAST FEW HRRR CYCLES HAVE HINTED AT LOWERING VISIBILITIES
ACROSS PARTS OF THE AREA PRIOR TO SUNRISE. HOWEVER...WITH WINDS
REMAINING MAINLY IN THE 10-15 MPH RANGE...FEEL WE WILL BE DEALING
MAINLY WITH LOW STRATUS AND SURFACE VISIBILITIES SHOULD REMAIN
OVERALL OKAY.
THE NEXT CHALLENGE WILL BE POPS FOR NOW THROUGH NEXT WEEK. THE
ATMOSPHERE IS UNSTABLE TODAY WITH MODEL FORECAST SB CAPE APPROACHING
1500 J/KG THIS AFTERNOON. NAM ALSO ERODES THE CAP ALMOST
COMPLETELY BY MID AFTERNOON...WHILE GFS HOLDS ONTO A GOOD AMOUNT
OF CIN. BELIEVE THAT WITH THE LACK OF A TRIGGER OR ANY UPPER LEVEL
SUPPORT...CONVECTION WILL HAVE A DIFFICULT TIME TODAY AND WILL
KEEP POPS BELOW 20 PERCENT WITHOUT ANY MENTION OF PRECIP IN THE
FORECAST. A SUBTLE SHORTWAVE WILL THEN PASS OVERHEAD DURING THE
DAY TOMORROW. FEEL THIS WILL ALLOW FOR THE DEVELOPMENT OF AT LEAST
ISOLATED STORMS. FOR NOW WILL LEAVE 20 POPS IN AREAWIDE AND REFINE
IF NEEDED LATER. THE UPPER DISTURBANCE SHIFTS EAST OF THE AREA
ALONG WITH THE ASSOCIATED PRECIPITATION THURSDAY NIGHT.
BY FRIDAY IT LOOKS LIKE THE RIDGE WILL BE TOO STRONG FOR
SIGNIFICANT RAIN CHANCES. ONE THING TO KEEP AN EYE ON WILL BE
DRYLINE DEVELOPMENT TO OUR NORTHWEST FRIDAY EVENING. AT THIS TIME
IT LOOKS LIKE ANY ACTIVITY THAT GETS GOING SHOULD DIMINISH BEFORE
REACHING THE AREA FRIDAY NIGHT. IF ANYTHING HOLDS TOGETHER AN
UPWARD ADJUSTMENT OF POPS MAY BE NEEDED LATE FRIDAY FOR THE
NORTHWESTERN COUNTIES.
THE UPPER RIDGE WILL BEGIN TO SLOWLY BREAK DOWN OVER THE WEEKEND
AS A LARGE SCALE UPPER TROUGH DEVELOPS OVER THE WESTERN CONUS.
ISOLATED SHOWERS AND STORMS WILL BE POSSIBLE BOTH SATURDAY AND
SUNDAY...ESPECIALLY DURING PEAK HEATING IN THE AFTERNOON. RAIN
CHANCES WILL THEN INCREASE SIGNIFICANTLY EARLY NEXT WEEK AS THE
UPPER TROUGH DIGS SOUTHEASTWARD TOWARDS THE REGION. GFS AND ECMWF
ARE SIMILAR WITH THE EVOLUTION OF THIS SYSTEM WITH ONLY MINOR
VARIATIONS IN THE TIMING. LARGE SCALE ASCENT AHEAD OF THE SYSTEM
SHOULD LEAD TO WIDESPREAD PRECIPITATION BY MONDAY OR MONDAY NIGHT.
MODELS ARE SHOWING NEGATIVE TILT...AND RESPECTIVE MODEL SOUNDINGS
AND HODOGRAPHS APPEAR CONDUCIVE FOR SEVERE WEATHER POTENTIAL. IT
IS STILL FAR TOO EARLY FOR ANY SPECIFICS BUT CERTAINLY WORTH
WATCHING AS THE FIRST DAYS OF SPRING DRAW NEAR. LONG RANGE
GUIDANCE THEN POINTS TOWARDS TEMPERATURES FINALLY RETURNING TO
NEAR-NORMAL AROUND THE MIDDLE OF NEXT WEEK AS THE AFOREMENTIONED
UPPER TROUGH SHOVES EAST OF THE AREA AND THE NEXT FRONT MOVES
THROUGH.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 77 66 78 66 77 / 10 10 20 10 10
WACO, TX 78 67 78 64 77 / 10 10 20 10 10
PARIS, TX 79 62 77 60 77 / 10 10 20 20 10
DENTON, TX 77 67 78 64 77 / 10 10 20 10 10
MCKINNEY, TX 77 67 77 65 77 / 10 10 20 20 10
DALLAS, TX 77 67 78 65 77 / 10 10 20 10 10
TERRELL, TX 78 66 78 64 77 / 10 10 20 20 10
CORSICANA, TX 78 65 78 64 78 / 10 10 20 10 10
TEMPLE, TX 78 66 78 64 77 / 10 10 20 10 10
MINERAL WELLS, TX 77 63 79 63 77 / 10 10 20 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
58/30
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
526 AM CDT WED MAR 14 2012
.AVIATION...
GENERAL MVFR CEILINGS ARE EXPECTED TO PREVAIL THROUGH LATE
MORNING. HAVE LEFT A MENTION OF LIGHT FOG AND SOME HIGHER END IFR
CEILINGS IN THE TAFS FOR THE 12-15Z PERIOD...BUT WITH SURFACE
WINDS OF 10-15 KNOTS WILL LIKELY JUST RESULT IN LOWER END MVFR
CEILINGS. AS GREATER VERTICAL MIXING OCCURS LATER THIS
MORNING...EXPECT TO SEE CEILINGS RISE BACK TO THE VFR CATEGORY.
MVFR CEILINGS SHOULD RETURN AFTER 06-08Z THURSDAY.
58
&&
.PREV DISCUSSION... /ISSUED 336 AM CDT WED MAR 14 2012/
UPPER LEVEL RIDGING AND PERSISTENT SOUTHERLY LOW LEVEL FLOW WILL
LEAD TO ABOVE-NORMAL TEMPERATURES ACROSS NORTH AND CENTRAL TEXAS
FOR THE NEXT SEVERAL DAYS. WITH ABUNDANT LOW LEVEL MOISTURE IN
PLACE...THERE IS SOME CONCERN FOR FOG DEVELOPMENT DURING THE
EARLY MORNING HOURS AS TEMPERATURES APPROACH DEWPOINT READINGS. IN
FACT THE LAST FEW HRRR CYCLES HAVE HINTED AT LOWERING VISIBILITIES
ACROSS PARTS OF THE AREA PRIOR TO SUNRISE. HOWEVER...WITH WINDS
REMAINING MAINLY IN THE 10-15 MPH RANGE...FEEL WE WILL BE DEALING
MAINLY WITH LOW STRATUS AND SURFACE VISIBILITIES SHOULD REMAIN
OVERALL OKAY.
THE NEXT CHALLENGE WILL BE POPS FOR NOW THROUGH NEXT WEEK. THE
ATMOSPHERE IS UNSTABLE TODAY WITH MODEL FORECAST SB CAPE APPROACHING
1500 J/KG THIS AFTERNOON. NAM ALSO ERODES THE CAP ALMOST
COMPLETELY BY MID AFTERNOON...WHILE GFS HOLDS ONTO A GOOD AMOUNT
OF CIN. BELIEVE THAT WITH THE LACK OF A TRIGGER OR ANY UPPER LEVEL
SUPPORT...CONVECTION WILL HAVE A DIFFICULT TIME TODAY AND WILL
KEEP POPS BELOW 20 PERCENT WITHOUT ANY MENTION OF PRECIP IN THE
FORECAST. A SUBTLE SHORTWAVE WILL THEN PASS OVERHEAD DURING THE
DAY TOMORROW. FEEL THIS WILL ALLOW FOR THE DEVELOPMENT OF AT LEAST
ISOLATED STORMS. FOR NOW WILL LEAVE 20 POPS IN AREAWIDE AND REFINE
IF NEEDED LATER. THE UPPER DISTURBANCE SHIFTS EAST OF THE AREA
ALONG WITH THE ASSOCIATED PRECIPITATION THURSDAY NIGHT.
BY FRIDAY IT LOOKS LIKE THE RIDGE WILL BE TOO STRONG FOR
SIGNIFICANT RAIN CHANCES. ONE THING TO KEEP AN EYE ON WILL BE
DRYLINE DEVELOPMENT TO OUR NORTHWEST FRIDAY EVENING. AT THIS TIME
IT LOOKS LIKE ANY ACTIVITY THAT GETS GOING SHOULD DIMINISH BEFORE
REACHING THE AREA FRIDAY NIGHT. IF ANYTHING HOLDS TOGETHER AN
UPWARD ADJUSTMENT OF POPS MAY BE NEEDED LATE FRIDAY FOR THE
NORTHWESTERN COUNTIES.
THE UPPER RIDGE WILL BEGIN TO SLOWLY BREAK DOWN OVER THE WEEKEND
AS A LARGE SCALE UPPER TROUGH DEVELOPS OVER THE WESTERN CONUS.
ISOLATED SHOWERS AND STORMS WILL BE POSSIBLE BOTH SATURDAY AND
SUNDAY...ESPECIALLY DURING PEAK HEATING IN THE AFTERNOON. RAIN
CHANCES WILL THEN INCREASE SIGNIFICANTLY EARLY NEXT WEEK AS THE
UPPER TROUGH DIGS SOUTHEASTWARD TOWARDS THE REGION. GFS AND ECMWF
ARE SIMILAR WITH THE EVOLUTION OF THIS SYSTEM WITH ONLY MINOR
VARIATIONS IN THE TIMING. LARGE SCALE ASCENT AHEAD OF THE SYSTEM
SHOULD LEAD TO WIDESPREAD PRECIPITATION BY MONDAY OR MONDAY NIGHT.
MODELS ARE SHOWING NEGATIVE TILT...AND RESPECTIVE MODEL SOUNDINGS
AND HODOGRAPHS APPEAR CONDUCIVE FOR SEVERE WEATHER POTENTIAL. IT
IS STILL FAR TOO EARLY FOR ANY SPECIFICS BUT CERTAINLY WORTH
WATCHING AS THE FIRST DAYS OF SPRING DRAW NEAR. LONG RANGE
GUIDANCE THEN POINTS TOWARDS TEMPERATURES FINALLY RETURNING TO
NEAR-NORMAL AROUND THE MIDDLE OF NEXT WEEK AS THE AFOREMENTIONED
UPPER TROUGH SHOVES EAST OF THE AREA AND THE NEXT FRONT MOVES
THROUGH.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 77 66 78 66 77 / 10 10 20 10 10
WACO, TX 78 67 78 64 77 / 10 10 20 10 10
PARIS, TX 79 62 77 60 77 / 10 10 20 20 10
DENTON, TX 77 67 78 64 77 / 10 10 20 10 10
MCKINNEY, TX 77 67 77 65 77 / 10 10 20 20 10
DALLAS, TX 77 67 78 65 77 / 10 10 20 10 10
TERRELL, TX 78 66 78 64 77 / 10 10 20 20 10
CORSICANA, TX 78 65 78 64 78 / 10 10 20 10 10
TEMPLE, TX 78 66 78 64 77 / 10 10 20 10 10
MINERAL WELLS, TX 77 63 79 63 77 / 10 10 20 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
58/30
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
556 AM CDT WED MAR 14 2012
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE.
.SHORT TERM...TODAY THROUGH THURSDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE HIGH
PRESSURE STRETCHING FROM THE SE U.S. TO THE CENTRAL GREAT
LAKES...WHILE A COLD FRONT IS HEADING EAST OVER THE NORTHERN
PLAINS. WARMER AND MORE HUMID AIR IS SURGING NE OVER THE CENTRAL
PLAINS WHERE DEWPOINTS AND TEMPERATURES ARE IN THE 50S AND 60S FROM
WESTERN IOWA TO KANSAS. AS THIS MOISTURE FLOWS INTO THE REGION
AHEAD OF THE FRONT LATE THIS AFTERNOON INTO TONIGHT...SMALL POPS ARE
THE MAIN FORECAST CONCERN FOR THIS FORECAST.
TODAY...STRONG SHORTWAVE MOVING NE OVER CENTRAL CANADA WILL PUSH A
WEAKENING COLD FRONT ACROSS THE MISSISSIPPI VALLEY THIS MORNING AND
INTO CENTRAL WISCONSIN THIS AFTERNOON. ANTICIPATE SE WINDS THIS
MORNING TO HOLD DEWPOINTS BACK SOMEWHAT...BUT SW WINDS THIS
AFTERNOON SHOULD BRING LOW TO MID 50S DEWPOINTS FROM KANSAS AND
OKLAHOMA INTO CENTRAL AND NORTHERN WISCONSIN. THE SW WINDS WILL
ALSO BRING PLENTY OF WARM AIR NE...WITH BOTH THE ECMWF AND NAM
SHOWING 18C AT 925MB...WHICH EQUATES TO MID TO UPPER 70S FOR HIGHS
OVER CENTRAL AND E-C WISCONSIN. AS THE FRONT APPROACHES THIS
AFTERNOON...A GENEROUS 77/56 PARCEL YIELDS ABOUT 2100 J/KG OF SB
CAPE AND 42 J/KG OF CIN AT STEVENS POINT. NORMALLY WOULDNT RULE OUT
CONVECTION ALONG THE FRONT WITH THAT SMALLISH LEVEL OF CIN...BUT
MID-LEVELS ARE AWFULLY DRY AND CONVERGENCE IS PRETTY WEAK ALONG THE
FRONT. WITH NO UPPER SUPPORT (MID-LEVEL HEIGHTS ACTUALLY
INCREASE)...HAVING TROUBLE ADDING ISOLATED POPS WHEN THINK ITS GOING
TO BE DIFFICULT JUST TO GENERATE CU. IF A STORM DOES POP...AMPLE
INSTABILITY COMBINED WITH LOW WET BULB ZERO HEIGHTS OF 7500 FT AND
MID-LEVEL DRY AIR SUGGEST A HAIL/WIND THREAT WOULD BE POSSIBLE.
CONFIDENCE IS TOO LOW THOUGH TO INCLUDE ISOLATED WORDING IN THE
FORECAST.
TONIGHT...THE FRONT WILL CONTINUE TO MOVE SLOWLY ACROSS THE REST OF
CENTRAL AND NORTHEAST WISCONSIN MOSTLY DURING THE EVENING HOURS.
THE AIRMASS ALONG THE BOUNDARY WILL BECOME INCREASINGLY MORE STABLE
AS NOCTURNAL COOLING SETS IN AND THINK A THREAT OF ELEVATED
CONVECTION IS SMALL WITH THE LLJ DEVELOPING EAST OF THE REGION.
WITH CONDITIONS ONLY BECOMING INCREASINGLY MORE HOSTILE TO
CONVECTION...JUSTIFYING POPS IS A DIFFICULT SELL IF GOING WITH A DRY
FORECAST IN THE AFTERNOON. WILL KEEP AN ISOLATED MENTION THOUGH TO
BLEND WITH SURROUNDING OFFICES. STATISTICAL GUIDANCE IS RATHER
BULLISH IN PRODUCING FOG TONIGHT ACROSS THE REGION. A DRY AIRMASS
ARRIVES NORTH OF THE FRONT OVER N-C WISCONSIN SO THINK THEY ARE
RELATIVELY SAFE. BUT CLOSER TO THE BOUNDARY...WHERE LIGHTER FLOW
AND ELEVATED DEWPOINTS RESIDE...THINK THERE IS POTENTIAL FOR FOG.
WILL ADD IT TO THE FORECAST.
THURSDAY...THE SURFACE FRONT WILL DROP INTO THE SOUTHERN GREAT LAKES
ON THURSDAY...WITH WINDS SHIFTING TO THE NE BEHIND THE BOUNDARY.
SINCE THE 850MB FRONT WILL HANG FARTHER BACK OVER CENTRAL AND NE
WISCONSIN...PLENTY OF LOW LEVEL MOISTURE WILL STICK AROUND AND WILL
GO WITH PARTLY TO MOSTLY CLOUDY CONDITIONS OVER NE WISCONSIN. NOT
OUT OF THE QUESTION THAT A COUPLE SHOWERS COULD DEVELOP OVER E-C
WISCONSIN BUT WILL LET LATER SHIFTS EVALUATE BEFORE GOING OUT OF
LINE WITH SURROUNDING OFFICES. QUITE A CHALLENGING TEMPERATURE
FORECAST DUE TO THE NE WINDS OFF LAKE MICHIGAN COMBINED WITH
POTENTIAL FOR CLOUD COVER AND A WARM AIRMASS IN PLACE. HAVE DROPPED
TEMPS NEXT TO THE BAY AND LAKE THOUGH ADMIT THAT POTENTIAL IS THERE
FOR THE LAKE INFLUENCE TO PENETRATE FARTHER INLAND. TEMPS WILL
MOSTLY BE IN THE 60S AWAY FROM THE BAY AND LAKE.
.LONG TERM...THURSDAY NIGHT THRU TUESDAY. MAIN FORECAST CHALLENGES
CONTINUE TO BE HOW WARM TEMPS WILL CLIMB...AND DETERMINING BEST
CHANCE FOR SHOWERS/STORMS.
MODELS FAIRLY CONSISTENT SHOWING SW FLOW ALOFT DEVELOPING LATE
THIS WEEK...AND CONTINUING INTO EARLY NEXT WEEK. VERY MILD AIR
WILL DOMINATE THE PERIOD...WITH MORE RECORDS LIKELY TO BE BROKEN.
925-850MB TEMPS SUPPORT TEMPS IN THE UPPER 60S AND 70S ACROSS
CENTRAL AND EAST-CENTRAL WI FROM SATURDAY-TUESDAY...WITH ONLY
SLIGHTLY COOLER TEMPS ACROSS THE NORTH. SIGNIFICANTLY COOLER TEMPS
ARE EXPECTED NEAR LAKE MICHIGAN WITH A PERSISTENT ONSHORE FLOW
STARTING FRIDAY.
WEAK SHORTWAVE PASSES NORTH OF THE AREA THURSDAY NIGHT...BUT WITH
WEAK LIFT AND LIMITED MOISTURE ABOVE 925MB...WILL CONTINUE WITH A
DRY FORECAST. MODELS SHOW THE POTENTIAL FOR FOG THURSDAY NIGHT AS
WINDS DIE OFF AND DEWPOINTS REMAINING IN THE 40S. BELIEVE MODELS
ARE BEING FOOLED WITH THE VERY WARM AIRMASS IN PLACE...AS
TEMP/DEWPOINT SPREADS REMAIN ABOVE 3 DEGREES FOR MOST LOCATIONS
THROUGH THE NIGHT...LIMITING FOG POTENTIAL. SOME MET/MAV GUIDANCE
EVEN SHOWING FOG WITH SPREADS NEAR 10 DEGREES. WILL ADD SOME
PATCHY FOG ACROSS THE FOX VALLEY AND LAKESHORE...AS SE WINDS OFF
LAKE MICHIGAN COULD BRING SOME COOLER...RELATIVELY MOIST AIR
INLAND...BUT FOG CHANCES NEED TO BE MONITORED FOR THE ENTIRE AREA.
MODELS SEEM TO BE FOCUSING ON LATE SATURDAY NIGHT AND SUNDAY
FOR THE NEXT BEST CHANCE FOR SHOWERS/STORMS ACROSS THE AREA...AS A
WEAK MID-LEVEL SHORTWAVE MOVES FROM THE SOUTHERN PLAINS INTO THE
WESTERN GREAT LAKES. NO OTHER REAL SUPPORT FOR CONVECTION UNDER
THIS SYNOPTIC PATTERN...SO WILL ONLY ADD SLIGHT CHANCE POPS IN FOR
NOW AND SEE HOW THIS SYSTEM DEVELOPS. TIMING THIS TYPE OF SYSTEM
WILL BE A CHALLENGE THIS FAR OUT...SO WOULD NOT BE SURPRISED IF
ADJUSTMENTS ARE NEEDED. UPPER RIDGE BUILDS OVER THE GREAT LAKES
FOR EARLY NEXT WEEK...AS DEEP TROUGH EJECTS OUT OF THE WESTERN
CONUS INTO THE PLAINS. THE RIDGE WILL KEEP STORM CHANCES WEST OF
THE AREA THROUGH AT LEAST TUESDAY...BEFORE THE RIDGE FINALLY
BREAKS DOWN ENOUGH TO ALLOW THE TROUGH TO PROGRESS SLOWLY
EASTWARD. HOWEVER...MODELS HAVE SIGNIFICANT DIFFERENCES IN TIMING
THIS TRANSITION...WITH THE ECMWF MUCH FASTER THAN THE GFS ON
WEDNESDAY. SOMETHING TO WATCH OVER THE NEXT FEW MODEL RUNS.
&&
.AVIATION...VFR CONDITIONS TODAY AS SURFACE WINDS VEER AROUND FROM
THE SE TO THE SW. EXPECT CLOUDS TO INCREASE LATE THIS AFTERNOON
INTO THIS EVENING WHEN A COLD FRONT MOVES ACROSS THE REGION.
CHANCES OF A SHOWER OR THUNDERSTORM WERE TOO SMALL TO INCLUDE IN THE
FORECAST...AS THE FRONT MAY BE TOO WEAK TO BREAK THE CAP. WINDS
WILL SHIFT AROUND TO THE NE BEHIND THE FRONT TONIGHT AND MAY BRING
LOW STRATUS OFF LAKE MICHIGAN INTO NE WISCONSIN LATE. PATCHY FOG IS
ALSO POSSIBLE LATE TONIGHT AS WINDS TURN CALM WITH THE FRONTAL
PASSAGE.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1124 AM MDT WED MAR 14 2012
.UPDATE...CURRENT FORECAST TRENDS STILL ON TRACK. BATCH OF MID AND
HIGH LEVEL MOISTURE ACROSS PORTIONS OF PLAINS SHOWING SIGNS OF
DECREASING AS IT HEADS EAST. POTENTIAL FOR MORE HIGH LEVEL CLOUD
THIS EVENING. AIRMASS DRY WITH LOW HUMIDITY FOR THE AFTERNOON.
WINDS TO REMAIN BELOW CRITICAL FIRE WEATHER THRESHOLDS.
&&
.AVIATION...SOUTHERLY SURFACE WINDS TO PREVAIL ACROSS THE AREA
AIRPORTS THROUGH THE EVENING. STILL THE POTENTIAL FOR A WESTERLY
PUSH OFF THE FOOTHILLS LATER THIS AFTERNOON AS NOTED BY MOST SHORT
TERM MODELS. HRRR SHOWING LIGHTER WINDS...WITH DIURNAL EASTERLY
PATTERN. WILL CONTINUE THE TREND OF CURRENT TAFS.
&&
.PREV DISCUSSION... /ISSUED 319 AM MDT WED MAR 14 2012/
SHORT TERM...VERY LITTLE CHANGE IN THE FORECAST WITH THE
CONTINUED SOUTHWEST FLOW ALOFT. SATELLITE IMAGERY SHOWING MUCH OF
THE HIGH CLOUDINESS DEPARTING TO THE NORTHEAST. THERE IS SOME
MORE CLOUDS UPSTREAM WHICH MAY INCREASE OVER COLORADO LATER TODAY
AND TONIGHT. MAIN STORY FOR TODAY IS THE CONTINUED WARM
TEMPERATURES WITH READINGS EXPECTED IN THE 70S. THE RECORD FOR
DENVER TODAY IS 78...SO THINK WILL BE A BIT SHY ON REACHING THE
RECORD. HUMIDITIES WILL AGAIN BE VERY LOW...AND IN FACT THERE HAS
BEEN VERY LITTLE RECOVERY DURING THE NIGHT AS SURFACE DEWPOINTS
HAVE REMAINED IN THE SINGLE DIGITS OVER THE FRONT RANGE. THE WINDS
WILL ACTUALLY BE A BIT LIGHTER TODAY AS THE MID LEVEL FLOW AS
WEAKENED. SO EVEN THOUGH HUMIDITY LEVELS WILL AGAIN BE UNDER 10
PERCENT...NOT EXPECTING MAJOR FIRE WEATHER CONCERNS DUE TO THE
LIGHTER WINDS.
LONG TERM...SOUTHWEST FLOW ALOFT CONTINUES TO BE PROGGED OVER
NORTHEASTERN COLORADO THROUGH THE END OF THE WEEK AS WE ARE IN
BETWEEN TROUGHING OVER THE WESTERN STATES AND RIDGING OVER THE
CENTRAL AND EASTERN STATES. THIS PATTERN WILL KEEP THE DRY AND
MUCH WARMER TEMPERATURES OVER THE FORECAST AREA THROUGH SATURDAY
AT LEAST. TEMPERATURES WILL CONTINUE TO BE 10 TO 20 DEGREES
WARMER THAN NORMAL OVER THE AREA.
THE UPPER TROUGH OVER THE WEST COAST WILL DIG SOUTH SATURDAY THEN
BEGIN TO MOVE INLAND SUNDAY. THIS IS WHERE MODELS CONTINUE TO
DIVERGE ON THEIR SOLUTIONS. THESE MODELS ARE NOT ONLY DIVERGING IN
FROM EACH OTHER...BUT ARE ALSO DIVERGING IN THEIR OWN RUN TO RUN
SOLUTIONS WITHIN EACH MODEL. SOME ARE DIGGING IT INTO A CUTOFF LOW
WHERE AS OTHERS KEEP IT AN OPEN TROUGH. EITHER WAY...ALL MODELS
ARE HAVING THE UPPER TROUGH/LOW FEATURE MOVE OVER THE STATE IN THE
MONDAY AND TUESDAY TIME FRAME.
FLOW ALOFT WILL BECOME SOUTHERLY SATURDAY INTO SUNDAY WITH
MOISTURE INCREASING. WILL LIKELY BEGIN TO SEE SOME ISOLATED SNOW
SHOWERS OVER THE MOUNTAINS LATE SATURDAY INTO SUNDAY...INCREASING
IN COVERAGE THROUGH THE FIRST HALF OF THE WEEK. TEMPERATURES WILL
STILL BE RELATIVELY WARM SO THE HIGH VALLEYS WILL LIKELY SEE RAIN
MIXING IN WITH THE SNOW...UNTIL MONDAY AND TUESDAY WITH THE SYSTEM
ALOFT AND SNOW LEVELS DROPPING AGAIN.
OVER THE PLAINS...SOUTHERLY SURFACE WINDS WILL BE INCREASING
SATURDAY AND SUNDAY AS LOW PRESSURE DEEPENS OVER THE NORTHERN
PLAINS AHEAD OF THE UPPER SYSTEM. WILL HAVE TO MONITOR THESE DAYS
FOR FIRE DANGER. HOWEVER A SLIGHT DECREASE IN TEMPERATURES EACH
DAY MAY HELP KEEP HUMIDITIES ABOVE CRITERIA. YET STILL THE EASTERN PLAINS
WILL LIKELY SEE GUSTS IN THE 30 TO 40 MPH RANGE ON THESE DAYS.
DEPENDING ON WHICH MODEL SOLUTION COMES TO FRUITION...WE MAY SEE
THESE STRONG SOUTHERLY WINDS AGAIN ON MONDAY...BUT TEMPERATURES
ARE EXPECTED TO COOL OFF ENOUGH TO TAKE LOW HUMIDITIES OUT OF THE
EQUATION. THERE IS A SLIGHT CHANCE OF SHOWERS MONDAY AS SYNOPTIC
LIFT AHEAD OF THE TROUGH WILL MOVE OVER THE STATE. AN ASSOCIATED
COLD FRONT IS EXPECTED TO DROP SOUTH OVER THE STATE SOMETIME
MONDAY NIGHT OR TUESDAY TO BRING EVEN COOLER TEMPERATURES AND A
MUCH BETTER CHANCE FOR PRECIPITATION. RIGHT NOW TEMPERATURES LOOK
TO STAY WARM ENOUGH FOR ONLY RAIN OR RAIN MIXED WITH SNOW TUESDAY.
AVIATION...VFR WITH UNRESTRICTED VISIBILITIES TODAY AND MAYBE
SOME HIGH LEVEL CLOUDINESS INCREASING TONIGHT. SURFACE WINDS WILL
REMAIN LIGHT UNDER 12KT FROM THE SOUTH TO SOUTHWEST THIS
MORNING...THEN MAYBE A PUNCH OF WESTERLY WINDS LATER THIS
AFTERNOON AS THE SURFACE GRADIENT TIGHTENS SLIGHTLY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....KRIEDERMAN
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
211 PM EDT WED MAR 14 2012
.SYNOPSIS...
HIGH PRESSURE WILL EXTENDED ACROSS THE REGION THROUGH LATE WEEK
BEFORE A BACKDOOR COLD FRONT DESCENDS INTO THE AREA OVER THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY THIS AFTERNOON...NO CHANGE TO THE FORECAST THINKING. BASED
ON RECENT RUNS OF THE HRRR AND THE GFS I HAVE ADDED AN AREA OF
CHANCE POPS ACROSS SE GA THIS AFTERNOON. OTHERWISE...THE CU FIELD
AND SEABREEZE ARE DEVELOPING AND WILL CONTINUE THROUGH THE
AFTERNOON. PREVIOUS DISCUSSION CONTINUES BELOW.
THE DEEP MOISTURE BOUNDARY IS QUITE NOTICEABLE ON WATER VAPOR
IMAGERY AND IN THE PWAT VALUES OFF THE 12Z SOUNDINGS FROM KCHS AND
KJAX. THE BOUNDARY CURRENTLY RESTS IN THE VICINITY OF THE ALTAMAHA
AND RUNS NEARLY WEST TO EAST WITH SOME ONGOING CONVECTION BACK
ACROSS CENTRAL AL/GA ASSOCIATED WITH WEAK AND SUBTLE SHORTWAVE
ENERGY DOWNSTREAM OF THE RIDGE AXIS. THIS ENERGY WILL CONTINUE TO
MOVE SLOWLY TO THE SE AS THE RIDGE AMPLIFIES AND SHOULD CROSS S GA
THIS AFTERNOON. SO...THIS FEATURE MAY PASS CLOSE ENOUGH TO OUR SE
GA AREAS TO PROVIDE SOME LIFT (ALBEIT WEAK). AT THE SURFACE...THE
WESTERN PERIPHERY OF THE SUBTROPICAL HIGH OVER THE ATLANTIC WILL
CONTINUE TO NOSE IN UNDER A OVERALL WEAK SYNOPTIC PATTERN. WITH
CLEAR SKIES AND VERY WARM LOW LEVEL THICKNESSES...HIGH TEMPS WILL
RISE TO ABOUT 10-12 DEGREES ABOVE CLIMO. THE ABUNDANT SURFACE
HEATING JUXTAPOSED WITH THE COOL WATER TEMPS (LOW 60S) JUST
OFFSHORE SHOULD SET THE STAGE FOR A PROMINENT SEABREEZE TODAY.
THIS SHOULD PUSH THROUGH IN TIME TO PREVENT TEMPS FROM GETTING OUT
OF THE LOW 80S WITH MUCH COOLER AIR BEHIND IT. I HAVE LEFT MAX
TEMPS AND HOURLY TEMPS ALONG FOR NOW AS THEY LOOK TO BE IN VERY
GOOD SHAPE.
AS THE SEA BREEZE MARCHES INLAND TODAY THE MAIN QUESTION WILL
REVOLVE AROUND THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS TO
DEVELOP. GIVEN THE WEAK UPPER SHORTWAVE PRESENT AND THE PLACEMENT
OF THE DEEP MOISTURE BOUNDARY...IT APPEARS THE AREA WITH THE BEST
CHANCE TO SEE ANY CONVECTIVE DEVELOPMENT IS SE GA. THUS...I HAVE
TRIMMED THE SLIGHT CHANCES AWAY FROM MUCH OF SOUTHERN SC AND
LIMITED IT TO AREAS NEAR THE SAVANNAH RIVER AND SE GA. ANY STORMS
THAT DO DEVELOP HAVE THE POTENTIAL TO GET INTERESTING. MODEL
SOUNDINGS SHOW STEEP MID LEVEL LAPSE RATES (500 MB TEMPS AROUND
-17C) WITH VERY DRY 700-500 MB AIR. AS A RESULT LI VALUES WILL
REACH -5 TO -6 WITH CAPES REACHING UPWARDS OF 2000 J/KG. THE
ROBUST MID LEVEL DRY AIR SHOULD ALSO RESULT IN DCAPES IN THE
800-1000 RANGE. SO...ANY THUNDERSTORMS THAT DO DEVELOP COULD BE
CAPABLE OF PRODUCING LARGE HAIL AND PERHAPS A DAMAGING WIND GUST.
I STILL ANTICIPATE THE OVERALL COVERAGE WILL BE LOW BUT WHAT DOES
DEVELOP COULD CERTAINLY BE STRONG TO SEVERE. WILL ADD A BRIEF
MENTION TO THE HWO TO HANDLE THE POSSIBLE THREAT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
TONIGHT...THE SEA BREEZE WILL BE APPROACHING THE FAR INTERIOR
ZONES BY SUNSET WITH THE RISK FOR ISOLATED SHOWERS/TSTMS OCCURRING
AHEAD OF IT. ANY RISK FOR MEASURABLE RAIN WILL QUICKLY END AS THE
CIRCULATION GRADUALLY WEAKENS AND MOVES WEST INTO THE MIDLANDS AND
EAST-CENTRAL GEORGIA. EXPECT DRY CONDITIONS OVERNIGHT. FOG COULD
BECOME AN ISSUE AGAIN AFTER MIDNIGHT...SOME OF WHICH COULD BECOME
LOCALLY DENSE. WILL SHOW PATCHY FOG IN THE GRIDDED AND TEXT
FORECASTS TO TREND. CLEAR SKIES AND LIGHT WINDS WILL PROMOTE
MODEST RADIATIONAL CONDITIONS SO FAVORED THE COOLER SIDE OF THE
GUIDANCE ENVELOP. LOWS WILL RANGE FROM THE LOWER 50S INLAND TO THE
UPPER 50S AT THE BEACHES. /77
THURSDAY....THE FORECAST AREA WILL BECOME LOCATED ALONG THE
PERIPHERY OF SURFACE HIGH PRESSURE CENTERED OVER THE ATLANTIC...
WHILE THE AXIS OF THE UPPER RIDGE LEANS INTO THE SOUTHEAST STATES.
LIMITED MID LEVEL MOISTURE...AS WELL AS SUBSIDENCE WITHIN DEEP
LAYER RIDGING...WILL LIKELY SUPPRESS CONVECTIVE DEVELOPMENT
THURSDAY AFTERNOON. HAVE THEREFORE CAPPED RAIN CHANCES BELOW 15
PERCENT AT THIS TIME. RISING HEIGHTS ALOFT...WARM SOUTH/SOUTHEAST
FLOW...AND MOSTLY CLEAR TO PARTLY CLOUDY SKIES...AGAIN SUPPORT
UNSEASONABLY WARM TEMPERATURES THURSDAY AFTERNOON. EXPECT HIGH
TEMPERATURES TO REACH THE LOW TO MID 80S AWAY FROM THE LOCALLY
COOLER COASTLINE.
FRIDAY...SHORTWAVE ENERGY WILL BEGIN TO BREAK THROUGH THE UPPER
RIDGE BY EARLY FRIDAY...AS A SURFACE TROUGH MOVES INTO THE
APPALACHIAN REGION. THICKER SKY COVER WILL GRADUALLY SPREAD WEST
TO EAST WITH DEEP MOISTURE INCREASING AS THE DAY PROGRESSES.
SLIGHTLY LOWER HEIGHTS ALOFT WITHIN THE WEAKENED RIDGE...AS WELL
AS LESS SUNSHINE ACROSS FAR INLAND AREAS LATE IN THE
DAY...SUGGESTS HIGH TEMPERATURES WILL BE A DEGREE OR TWO COOLER IN
THE LOWER 80S AWAY FROM THE COAST. WILL ALSO INTRODUCE A SLIGHT
CHANCE FOR SHOWERS/THUNDERSTORMS ACROSS FAR INLAND
LOCATIONS...CLOSEST TO MOISTURE CONVERGENCE FROM THE SURFACE
TROUGH AND RESULTING UPSTREAM CONVECTION.
SATURDAY...A WEAK FRONT EMBEDDED WITHIN THE SURFACE TROUGH WILL
GRADUALLY SHIFT EAST/SOUTHEAST FRIDAY NIGHT INTO SATURDAY...PULLED
BY A DEVELOPING WAVE OF LOW PRESSURE OFF THE VIRGINIA/NORTH
CAROLINA COASTLINE. THE WEAKENING FRONT WILL DESCEND TOWARD THE
FORECAST AREA DURING THE AFTERNOON AND EVENING HOURS...BRINGING A
SLIGHT CHANCE FOR SHOWERS/THUNDERSTORMS TO MANY LOCATIONS. AS THE
FRONT IS EXPECTED TO BECOME DIFFUSE LATE SATURDAY...IT IS
POSSIBLE THAT PORTIONS OF THE GEORGIA COASTLINE COULD NOT SEE ANY
RAIN WITH THIS SYSTEM. HIGH TEMPERATURES WILL BE MITIGATED BY MORE
ABUNDANT CLOUD COVER AND POSSIBLY WEAK UPPER TROUGHING...LIKELY
RANGING FROM THE UPPER 70S NORTH TO THE LOWER 80S SOUTH OF THE
FRONT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
SURFACE HIGH PRESSURE WILL BUILD FROM THE NORTH BEHIND THE
DESCENDING/DISSIPATING FRONT ON SUNDAY. DRIER AIR WILL SHIFT INTO
THE REGION ACCORDINGLY. HOWEVER...ENOUGH LINGERING MOISTURE AND
CONVERGENCE IN THE VICINITY OF THE FRONT COULD SUPPORT ISOLATED
SHOWERS/THUNDERSTORMS SUNDAY ACROSS THE FAR SOUTHWEST COUNTIES
AHEAD OF THE SEABREEZE. HIGH PRESSURE WILL GENERALLY REMAIN IN
CONTROL OF THE PATTERN THROUGH AT LEAST EARLY NEXT WEEK...WHILE A
HIGHLY AMPLIFIED UPPER RIDGE DEVELOPS OVER THE ENTIRE EASTERN
UNITED STATES. MID RANGE MODELS ALL SEEM TO DEVELOP A COASTAL
TROUGH OF VARYING DEGREES ACROSS THE SOUTHEAST COAST...WHICH COULD
IMPACT MOISTURE CONVERGENCE AND RESULTING RAIN CHANCES...ESPECIALLY
ALONG THE COAST. PREFER TO KEEP POPS UNDER 15 PERCENT AT THIS
TIME...UNTIL BETTER MODEL CONSISTENCY LEADS TO HIGHER CONFIDENCE
IN SUCH DETAILS. TEMPERATURES WILL REMAIN UNSEASONABLY WARM
THROUGH THE EXTENDED PERIOD...WITH HIGH TEMPERATURES TYPICALLY
REACHING THE UPPER 70S AWAY FROM THE LOCALLY COOLER COASTLINE.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR CONDITIONS ARE EXPECTED TO PREVAIL INTO THE EVENING. I HAVE
ADDED A TEMPO GROUP FOR VICINITY SHOWERS AND A CB MENTION AT KSAV AS
ISOLATED TO WIDELY SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP
ALONG THE SEABREEZE. THE LIKELIHOOD IS HIGHER AT KSAV COMPARED TO
KCHS SO I HAVE LEFT IT OUT THERE.
TONIGHT THE FOCUS ONCE AGAIN TURNS TO THE POTENTIAL FOR FOG
DEVELOPMENT. MODEL GUIDANCE IS MIXED WITH SOME INDICATIONS OF THE
POTENTIAL FOR DENSE FOG...AND OTHER INDICATIONS OF ONLY PATCHY
MVFR FOG OR SHALLOW GROUND FOG. AGAIN FOG CHANCES ARE HIGHLY
DEPENDENT ON THE COVERAGE OF CLOUDS OVERNIGHT. MODELS CONTINUE TO
DEPICT AT LEAST SOME DEGREE OF CLOUDINESS IN THE 4-6 KFT RANGE
WHICH MAY PREVENT VSBYS FROM GETTING TOO LOW. I HAVE ADDED MVFR
LEVEL FOG TO THE TAF/S THIS PACKAGE THOUGH FUTURE ISSUANCES MAY
NEED TEMPO GROUPS TO ACCOUNT FOR LOWER VSBYS.
EXTENDED AVIATION OUTLOOK...MODERATE POTENTIAL FOR LATE NIGHT/EARLY
MORNING FOG AND/OR LOW CEILINGS THROUGH AT LEAST FRIDAY MORNING.
&&
.MARINE...
A BROAD SOUTHERLY WIND REGIME WILL PERSIST THROUGH TONIGHT AS THE
WATERS REMAIN ALONG THE WESTERN FRINGES OF ATLANTIC HIGH PRESSURE.
WINDS WILL BECOME ENHANCED IN THE CHARLESTON HARBOR AND NEAR THE
LAND/SEA INTERFACE THIS AFTERNOON AS A ROBUST RESULTANT FORMS AND
MOVES INLAND. WINDS SHOULD MAX OUT NO HIGHER THAN 15 KT. OTHERWISE
BOTH WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY
THRESHOLDS THROUGH TONIGHT.
THURSDAY THROUGH SUNDAY...EXPECT GENERALLY QUIET MARINE
CONDITIONS THROUGH SATURDAY DUE TO A WEAK PRESSURE PATTERN IN
PLACE...AS ATLANTIC HIGH PRESSURE GENERALLY DOMINATES. SEAS WILL
MAINLY FALL WITHIN A 2 TO 4 FT RANGE...MAINLY IN AN 8 TO 9 SECOND
EAST SWELL. CONDITIONS COULD BECOME FAVORABLE FOR SEA FOG DEVELOPMENT
ALONG THE COOL NEARSHORE WATERS LATER THIS WEEK...AS SURFACE
DEWPOINTS RISE...BUT PROBABILITIES ARE TOO LOW TO JUSTIFY MENTIONING
IN THE FORECAST AT THIS TIME.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
134 PM EDT WED MAR 14 2012
.PREV DISCUSSION... /ISSUED 1018 AM EDT WED MAR 14 2012/
UPDATE...
WHATS LEFT OF THE FOG OVER W GA EXPECTED TO QUICKLY IMPROVE.
DECENT INSTABILITY FORECAST OVER W AND CENTRAL GA WITH THE MAIN
UPPER SHORT WAVE PASSING BY THIS MORNING AND ANOTHER MOVING TO FAR
NW GA LATE DAY. WILL JUST NEED TO MONITOR THINGS AS THE 12Z NAM IS
PRODUCING NO PRECIP THIS AFTERNOON AND SPOTTY LOW AMOUNTS TONIGHT.
FORECAST HIGH TEMPERATURES RUNNING 13-16 DEGREES ABOVE NORMAL
TODAY AND 1-3 DEGREES BELOW RECORDS. BDL
PREV DISCUSSION... /ISSUED 746 AM EDT WED MAR 14 2012/
UPDATE...
WILL SEND A QUICK UPDATE TO UPDATE POPS ACROSS WEST CENTRAL
GEORGIA. PESKY SHOWERS IN HARALSON...POLK...AND PAULDING COUNTIES
ARE MAINTAINING THEMSELVES SO HAVE ADJUSTED POPS ACCORDINGLY.
TDP
SHORT TERM /TODAY THROUGH THURSDAY NIGHT/...
SHORTWAVE THAT MOVED THROUGH THE AREA LAST NIGHT CONTINUES TO
PRESS TOWARD THE COAST...AS RIDGING BUILDS ACROSS THE SOUTHEAST.
OVERALL...SHORT- TERM MODEL MASS FIELDS ARE FAIRLY SIMILAR BUT
HAVE SIDED WITH THE GFS AS IT AND THE ECMWF ARE IN BETTER
AGREEMENT... NAM IS A LITTLE FASTER AND A LITTLE MORE AGGRESSIVE
WITH THE MOISTURE.
BEST DEEP MOISTURE WILL BE SHUNTED SOUTH TODAY BY THE EXITING
SHORTWAVE BUT WITH TEMPERATURES CLIMBING INTO THE 80S JUST ABOUT
EVERYWHERE PLUS PLENTIFUL SURFACE MOISTURE...MLCAPE VALUES THIS
AFTERNOON CLIMB TO ABOVE 1000 J/KG ACROSS THE AREA. HRRR AND LOCAL
WRF DO DEVELOP CONVECTION THIS AFTERNOON BUT MAINLY LIMIT IT TO
THE SOUTHWEST CORNER. FOR THESE REASONS...HAVE INCLUDED SLIGHT
CHANCE POPS BUT KEPT POPS CONFINED MAINLY SOUTH. VERY LITTLE SHEAR
TO WORK WITH /LESS THAN 30M2/S2 0-6KM SHEAR/ SO DO NOT EXPECT
CONVECTION TO REALLY ORGANIZE...BUT LAPSE RATES REMAIN PRETTY
STEEP /AROUND 7C/KM/. OVERALL DO NOT REALLY EXPECT ANY SEVERE
THUNDERSTORMS...HOWEVER CENTRAL GEORGIA DID SEE LARGE HAIL LAST
NIGHT SO IT CANNOT BE TOTALLY RULED OUT.
AS MENTIONED...HIGH TEMPS TODAY EXPECTED TO CLIMB INTO THE 80S
JUST ABOUT EVERYWHERE...WITH MID 80S POSSIBLE ON THURSDAY. TODAY/S
HIGHS REMAIN JUST BELOW RECORD VALUES BUT THURSDAY/S FORECAST DOES
INCLUDE SOME RECORDS...SEE CLIMATE SECTION BELOW.
ANOTHER SHORTWAVE MOVES ACROSS THE OHIO VALLEY THURSDAY NIGHT INTO
FRIDAY...THUS POPS RETURN TO NORTH GEORGIA LATE IN THE SHORT-
TERM. OVERALL A VERY SUMMER-LIKE PATTERN WITH WARM TEMPS...A MOIST
BOUNDARY LAYER...AND A HIGH CAPE LOW SHEAR ENVIRONMENT.
TDP
LONG TERM /FRIDAY THROUGH TUESDAY/...
SUMMER HAS STARTED EARLY. A HIGH-AMPLITUDE RIDGE TAKES FIRM HOLD
OF THE EASTERN U.S. WITH GFS PUSHING 587 DM 500 MB HEIGHTS
THROUGH THE WEEKEND. ALL EXTENDED MODELS AND ENSEMBLES ARE
CONSISTENT IN THIS...SO CONFIDENCE IS FAIRLY HIGH FOR HIGHER THAN
NORMAL TEMPS. THEREFORE...I BUMPED MAX TEMPS UPWARD A FEW DEGREES
IN THE EXTENDED TO COUNTERACT MOS TENDENCIES TOWARD CLIMATOLOGICAL
NORMS. PRECIPITABLE WATER VALUES REMAIN MUCH HIGHER THAN NORMAL
FOR THIS PERIOD...SO INCREASED AFTERNOON POPS TO REFLECT
SCATTERED...SUMMER-LIKE CONVECTION FOR THE WEEKEND. GFS SLIDES
SLIGHTLY DRIER AIR MOVES INTO NORTH GEORGIA BY MONDAY...SO POP
CHANCES DIMINISH. AM NOT QUITE CONVINCED THIS WILL BE ENOUGH TO
ELIMINATE PRECIP CHANCES...ESPECIALLY WITH ONSHORE FLOW BEGINNING
AS SURFACE RIDGE CENTERS ON MID-ATLANTIC SEABOARD EARLY IN THE
WEEK. WILL GO WITH /LOW/ MOS POPS FOR NOW...BUT THEY MAY BE TOO
LOW.
27
CLIMATE...
RECORDS FOR 03-14
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 84 1918 33 1993 61 1933 16 1926
1918
KATL 82 1989 33 1993 64 1918 18 1993
1926
KCSG 84 1989 40 1993 65 1973 20 1993
1982
KMCN 85 1973 41 1993 67 1918 21 1926
1953
1918
RECORDS FOR 03-15
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 84 1921 43 1960 62 1990 19 1993
1989
KATL 81 1973 39 1901 64 1989 20 1993
1946
KCSG 83 1989 44 1960 66 1973 21 1993
KMCN 86 1977 42 1960 65 1990 20 1993
1973
RECORDS FOR 03-16
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 82 1945 37 1960 62 2002 19 1890
KATL 84 1945 34 1900 64 2002 18 1890
KCSG 85 2002 51 1969 65 2002 27 1988
1949
KMCN 87 1955 42 1900 65 1942 26 1916
RECORDS FOR 03-17
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 85 1945 39 2005 62 1945 23 1924
KATL 86 1945 38 1892 65 2002 23 1895
KCSG 88 2002 45 2005 67 2002 30 1981
1954
KMCN 88 1945 44 2005 65 1908 27 1988
RECORDS FOR 03-18
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 87 1921 45 1998 63 1908 23 1967
1941
1902
KATL 84 1982 30 1892 67 1908 20 1902
KCSG 89 1982 49 1988 64 1982 29 1967
KMCN 88 1908 43 1902 67 1908 28 2007
1941
RECORDS FOR 03-19
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 86 1982 45 1947 61 1908 22 1892
KATL 85 1982 44 1892 65 1927 17 1892
KCSG 88 1982 52 2001 66 1948 30 1985
1960
KMCN 88 1963 49 1947 64 1982 26 1967
1945 1902
1927
RECORDS FOR 03-20
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 86 1907 38 1906 62 1948 20 1923
KATL 86 1907 36 1906 67 1948 17 1923
KCSG 85 2004 46 2001 66 1982 31 1956
1996 1948 1949
KMCN 90 1907 45 1906 67 1907 23 1923
&&
.AVIATION...
18Z UPDATE...
VFR CONDITIONS THIS AFTERNOON WITH 4000-5000 SCT-BKN CONDITIONS.
POTENTIAL FOR IFR-MVFR VSBYS OVERNIGHT DUE TO FOG. SMALL POTENTIAL
FOR THUNDERSTORMS TO AFFECT CSG/MCN AND POSSIBLY GET CLOSE TO ATL
AREA. SURFACE WINDS GENERALLY WEST AROUND 5 KTS THIS AFTERNOON
BECOMING CALM OR LIGHT AND VARIABLE OVERNIGHT.
//ATL CONFIDENCE...18Z UPDATE...
HIGH CONFIDENCE THIS AFTERNOON EXCEPT LOW CONFIDENCE FOR
CONVECTION AND IMPACTS.
HIGH CONFIDENCE FOR WINDS OVERNIGHT.
LOW TO MEDIUM CONFIDENCE FOR CEILINGS AND VSBYS OVERNIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 82 54 85 58 / 10 10 10 20
ATLANTA 80 61 83 62 / 10 10 20 20
BLAIRSVILLE 75 51 76 54 / 10 10 20 30
CARTERSVILLE 80 51 81 54 / 10 10 20 20
COLUMBUS 83 58 85 61 / 20 10 10 10
GAINESVILLE 79 57 82 60 / 10 10 20 20
MACON 83 54 84 58 / 20 10 10 10
ROME 82 52 81 55 / 10 10 30 30
PEACHTREE CITY 81 50 82 54 / 20 10 10 10
VIDALIA 83 57 85 59 / 20 10 5 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
253 PM CDT WED MAR 14 2012
.DISCUSSION...
ISSUED 252 PM CDT WED MAR 14 2012
18Z SFC MAP SHOWED A LATE SPRING PATTERN IN PLACE AS SOUTHWEST WINDS
GUSTING UP TO 30 MPH AHEAD OF A COLD FRONT IN WESTERN
IOWA...HELPED BOOST TEMPERATURES TO RECORD LEVELS THE UPPER
70S AND LOWER 80S. SEVERAL DAYS OF SUSTAINED SOUTHERLY FLOW HAS
ALLOWED DEWPOINTS TO CLIMB TO UNSEASONABLY HIGH LEVELS IN THE
LOWER 60S. ALOFT...BROAD WEST-SOUTHWEST MID LEVEL FLOW FEATURED
SEVERAL WEAK EMBEDDED SHORTWAVES WHICH WILL BE THE FOCUS FOR
THUNDERSTORM CHANCES THE NEXT FEW DAYS.
SHORT TERM...TONIGHT THROUGH THURSDAY
POTENTIAL CONVECTION FOR THE SOUTHEAST HALF OF THE AREA LATE THIS
AFTERNOON AND EVENING IS FIRST FORECAST CONCERN. WARM AND HUMID
BOUNDARY LAYER COMBINED WITH STEEP MID LEVEL LAPSE RATES AND
INCREASING MOISTURE ADVECTION BELOW 800 MB HAVE LED TO AN UNCAPPED
ATMOSPHERE WITH SURFACE BASED CAPES OF 2500-3000 J/KG. INCREASING
DPVA AHEAD OF A WEAK SHORTWAVE LIFTING NE OUT OF OKLAHOMA SHOULD
LEAD TO AN INCREASE IN CONVECTION ACROSS SOUTHEAST MISSOURI AND
SOUTHERN ILLINOIS OVER THE NEXT COUPLE HOURS. WIND FIELDS ALOFT
ARE UNCHARACTERISTICALLY WEAK FOR EARLY SPRING...WITH 0-6 KM
EFFECTIVE SHEAR ONLY 25 KTS. THIS SHOULD LEAD TO A
DISORGANIZED/PULSE TYPE THUNDERSTORM MODE AND EVEN WITH HIGH
INSTABILITY WOULD ONLY EXPECT SOME NEAR SVR WIND GUSTS AND HAIL
PRIMARILY IN A 3PM-7PM WINDOW...AND BEST CHANCES SOUTH OF I-70. THIS
THINKING IS SUPPORTED BY LATEST RUN HIGH-RES HRRR AND WRF-NMM
MODEL RUNS...WITH ANY CONVECTION PUSHING INTO INDIANA AFTER 7 OR 8
PM.
THE NEXT FOCUS FOR THUNDERSTORM DEVELOPMENT LOOKS TO BE
AHEAD OF THE COLD FRONT TO OUR NORTHWEST. ISOLATED TO SCATTERED
ELEVATED STORMS SHOULD FORM LATER THIS EVENING NEAR OR EAST OF THE
MISSISSIPPI RIVER AS 30-35 KT WSW ORIENTED LOW LEVEL JET DEVELOPS.
DUE TO LIMITED INSTABILITY SEVERE STORMS ARE NOT EXPECTED WITH
THIS ACTIVITY AS IT DROPS SOUTHEAST OVERNIGHT.
THE COLD FRONT WILL BECOME ALIGNED WITH THE UPPER LEVEL FLOW ON
THURSDAY AND TEND TO PUSH MORE EAST THAN SOUTH. CURRENT GUIDANCE
SUGGESTS THE FRONT WILL NOT MAKE IT INTO OUR CWA SO ANOTHER DAY
WITH HIGHS NEAR 80. ASSUMING THE FRONT STAYS TO OUR NORTH AND
WASHES OUT...ANY CONVECTION WOULD BE DRIVEN BY SUBTLE SHORTWAVE
ENERGY. HAVE MAINTAINED LOW CHC POPS DUE TO UNCERTAINTY IN
TIMING OR LOCATION OF DEVELOPMENT...BUT WITH HIGH INSTABILITY HAIL
AND GUSTY WINDS WOULD BE POSSIBLE.
LONG TERM...FRIDAY THROUGH WEDNESDAY
THE EXTENDED PORTION OF THE FORECAST WILL FEATURE AN AMPLIFIED
UPPER AIR PATTERN WITH A WESTERN TROUGH DEEPENING AS IT APPROACHES
THE ROCKIES EARLY NEXT WEEK...WHILE A STRONG RIDGE BUILDS ACROSS
THE EASTERN THIRD OF THE COUNTRY. THIS WILL KEEP THE LOCAL AREA
BATHED IN SOUTHERLY FLOW AND TEMPERATURES MORE TYPICAL OF MID TO
LATE MAY WITH HIGHS IN THE 70S TO NEAR 80 AND LOWS IN THE UPPER 50S.
DEW POINTS WILL CONTINUE TO BE UNSEASONABLY HIGH IN THE UPPER 50S
TO LOWER 60S...GIVING A SOMEWHAT HUMID FEEL TO THE AIR. THE BEST
CHANCE OF THUNDERSTORMS DURING THE PERIOD WILL BE SATURDAY WHEN A
MORE ORGANIZED SHORTWAVE LIFTS FROM THE CENTRAL PLAINS INTO THE
LOWER GREAT LAKES. HAVE TRIED TO FOCUS ANOTHER PERIOD OF HIGHER
POPS LATE IN THE EXTENDED WHEN THE UPPER TROUGH TRACKS EAST INTO
THE PLAINS. LATEST 12Z RUN GFS AND ECMWF HAVE SLOWED THIS SYSTEM
WITH AN UPPER LOW CUTTING OFF IN THE SOUTHERN OR CENTRAL PLAINS.
THIS WOULD KEEP THE AREA IN SOUTHERLY FLOW THROUGH MID WEEK WITH
EASTERN FRINGES OF A MORE UNSETTLED PATTERN APPROACHING THE
MISSISSIPPI RIVER VALLEY.
25
&&
.AVIATION...
ISSUED 1255 PM CDT WED MAR 14 2012
EXPECT ISOLATED CONVECTION TO DEVELOP AFTER 20Z/3 PM OVER THE I-72
CORRIDOR REACHING SPI AND DEC FIRST AND GOING UNTIL MID EVENING
UNTIL 02Z-04Z AS CONVECTION CHANCES SHIFT FURTHER SE WITH LOW
LEVEL JET ENHANCEMENT AND A SUBTLE SHORT WAVE. HAVE VCTS AT
SPI...DEC AND CMI TO ACCOUNT FOR THIS ISOLATED CONVECTION AND LESS
OF A CHANCE AT PIA AND BMI SO KEPT THEM DRY. HIGH END MVFR BROKEN
CEILINGS AROUND 3K FT POSSIBLE THIS AFTERNOON AND EARLY EVENING
ACROSS CENTRAL IL. EXTENSIVE CUMULUS CLOUD FIELD ALREADY OVER
AREAS WEST OF I-57 AT MIDDAY WITH GENERALLY LOW END VFR CEILINGS
FROM 3-4K FT. BREEZY SSW WINDS OF 12 TO 17 KTS WITH GUSTS OF 20-27
KTS THIS AFTERNOON TO GRADUALLY DIMINISH THIS EVENING TO BETWEEN
10-15 KTS. A COLD FRONT FROM NW WI/IA INTO CENTRAL KS TO PRESS SE
TOWARD THE IL/IA BORDER BY THU MORNING BUT NOT MUCH CONVECTION
EXPECTED ALONG THIS BOUNDARY THROUGH THU MORNING.
HUETTL
&&
.CLIMATE...
ISSUED 252 PM CDT WED MAR 14 2012
RECORD HIGHS FOR...WEDNESDAY.............THURSDAY
BLOOMINGTON........76 IN 2007............76 IN 2007
CHAMPAIGN..........78 IN 2007............76 IN 1995
DECATUR............78 IN 2007............78 IN 1995
EFFINGHAM..........81 IN 2007............79 IN 2007
LINCOLN............77 IN 1933............78 IN 1935
PEORIA.............76 IN 1995............77 IN 1935
SPRINGFIELD........75 IN 1971/75/2007....79 IN 1935/1995
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
244 PM CDT WED MAR 14 2012
.DISCUSSION...
1136 AM CDT
GOING FORECAST FOR THIS AFTERNOON...INCLUDING RECORD
WARMTH...LOOKS GOOD. TEMPERATURES ALREADY ARE REACHING THE MID 70S
AT 1130 AM IN SOME PARTS OF THE FORECAST AREA. MIXING ON BOTH ILX
AND DVN SOUNDINGS WOULD PROVIDE LOWER 80S...EVEN MID 80S ON THE
LATTER. INCREASING DEW POINTS AND SOME CIRRUS/CU WILL LIKELY KEEP
VALUES BETWEEN 79 AND 82 ACROSS MOST OF THE CWA.
A SOMEWHAT NOISY UPSTREAM MID-LEVEL FLOW EXISTS PER WATER VAPOR
SATELLITE IMAGERY AND PROFILERS. THERE APPEARS TO BE A COUPLE
LOW AMPLITUDE SHORT WAVE RIPPLES APPROACHING IL FROM IA AND MO.
INSTABILITY IS ALSO ON THE INCREASE FROM THE SOUTHWEST...WITH THE
COMBINATION OF THIS AND THE AFOREMENTIONED SHORT WAVES GENERATING
AGITATED CU/ACCAS ACROSS EASTERN MO AND SOUTHWEST IL. THIS IS ON
THE LEADING EDGE OF MUCAPES AROUND 2000 J/KG AND ELEVATED MOISTURE
TRANSPORT. THIS LEADING GRADIENT IS EXPECTED TO PROPAGATE
NORTHEAST OVER THE FORECAST AREA LATER THIS AFTERNOON INTO THIS
EVENING. EXPLICIT CONVECTIVE MODELS SUCH AS THE HRRR AND WRF
INDICATE SOME SCATTERED CONVECTION DEVELOPING ACROSS DOWNSTATE IL
WORKING NORTHEAST INTO OR NEAR THE SOUTHEAST FORECAST AREA. THIS
SEEMS PLAUSIBLE GIVEN THE FORECAST STRONG INSTABILITY AND THE
AGITATED FLOW ALOFT.
THE LOW-LEVEL JET IS ALSO FORECAST TO INTENSITY THIS
EVENING...DRIVEN IN PART TO THE APPROACHING NORTHERN STREAM COLD
FRONT. THIS COULD AS WELL INDUCE SCATTERED THUNDERSTORM COVERAGE
FURTHER WEST AND NORTH. THIS INCLUDES OVERNIGHT...AS THE
CONVERGENCE OF THE FRONTAL BOUNDARY MOVES INTO THE REGION. THE
DEEP LAYER SHEAR FROM LATE AFTERNOON INTO TONIGHT IS FAIRLY
MARGINAL FOR WELL ORGANIZED STORMS...ON THE ORDER OF 20 TO 30 KTS.
SO THE POTENTIAL FOR ANY SEVERE STORMS WOULD SEEM A LITTLE BETTER
WHEN THE INSTABILITY IS ITS DEEPEST AND THE LOW-LEVEL JET NOSE IS
INTO OUR AREA...BASICALLY WITH THE EVENING CONVECTION ACROSS OUR
SOUTHEAST FORECAST AREA /IF IT CAN DEVELOP THIS FAR NORTH/...BUT
INSTABILITY IS MODEST ENOUGH THROUGH ALL OF TONIGHT ACROSS OUR
ENTIRE FORECAST AREA THAT IT WILL BE SOMETHING TO CONTINUE TO
MONITOR.
MTF
//PREV DISCUSSION...
314 AM CDT
ADJUSTMENTS TO TEMPERATURE FORECAST FOR LATE THU AND FRI THANKS TO
PNEUMONIA FRONT PUSHING DOWN LAKE MICHIGAN...THIS WILL BREAK THE
STRING OF 70 DEGREE DAYS FOR CHICAGO...OTHERWISE MILD WEATHER
THROUGH THE MIDDLE OF NEXT WEEK. OTHER CONCERN IS POTENTIAL FOR
THUNDERSTORMS...MAINLY THU THROUGH SAT NIGHT.
SHORT WAVE TROF MOVING THROUGH THE NORTHERN ROCKIES TOWARD HUDSON
BAY TODAY WITH BROAD SOUTHWEST FLOW OVER THE MIDWEST. AT THE
SURFACE...HIGH PRESSURE SETTLING OVER THE SOUTHEAST STATES. SURFACE
LOW ASSOCIATED WITH CANADIAN SHORT WAVE WILL DRAG A TRAILING COLD
FRONT/TROF THROUGH THE PLAINS TODAY AND INTO UPPER GREAT LAKES BY
TONIGHT. A STRONG PRESSURE GRADIENT WILL SET UP ACROSS
NORTHERN IL AND NORTHWEST IN TODAY. SOUTHWESTERLY WINDS WILL
TRANSPORT UNSEASONABLY WARM MOIST AIR INTO THE REGION. NAM
SOUNDINGS AND 925 MB TEMPS STILL SUPPORT UPPER 70S TO NEAR 80
TODAY.
THE FRONT SAGS SOUTH DOWN THE LAKE TONIGHT INTO THU MORNING.
NAM/SREF APPEAR TO HAVE A MUCH BETTER HANDLE ON HOW FAR SOUTH THE
FRONT SAGS AND ALSO THE LOW LEVEL THERMAL PROFILES FOR THU AND FRI.
WITH FRONT PUSHING DOWN THE LAKE THIS TIME OF YEAR...THE COLD HEAVY
AIR OVER THE LAKE HAS A TENDENCY TO PUSH FRONTS FURTHER SOUTH THAN
THE MODELS WOULD SUGGEST. SO WILL LEAN HEAVILY ON NAM/SREF FOR WINDS
AND TEMP TRENDS THU AND FRI. EXPECT TEMPERATURES IN THE 70S FOR
MUCH OF THE AREA AGAIN THU BUT AREAS NEAR LAKE MI WILL SEE
TEMPERATURES PLUMMET THROUGH THE AFTERNOON AS THE COLD LAKE AIR SPREADS
SOUTHWEST ACROSS NORTHERN IL AND NORTHWEST IN. THE AREA SHOULD
REMAIN IN EAST FLOW MUCH OF FRI MORNING BUT AS UPPER LEVEL RIDGE
REBUILDS AND SURFACE WINDS GRADUALLY TURN SOUTHEAST THEN
SOUTH...AREAS AWAY FROM THE LAKE SHOULD WARM UP INTO THE 70S.
MOS GUIDANCE SUGGESTING DENSE FOG DEVELOPING TONIGHT THROUGH THU
NIGHT BUT WE THINK MOS IS EXPECTING THE GROUND TO BE MUCH
COLDER/WETTER THIS TIME OF YEAR...AND ISNT QUITE SURE HOW TO
HANDLE 60 DEGREE DEWPOINTS IN MID MARCH. WILL LIKELY SEE FOG
DEVELOP OVER THE LAKE THIS AFTERNOON AS UNSEASONABLY HUMID AIR
SPREADS NORTH. COULD SEE THE FOG SPREAD INLAND THURSDAY AFTERNOON
AND EVENING AS THE COOL AIR MASS PUSHES INLAND. DIFFICULT ENOUGH
TO FORECAST FOG A FEW HOURS IN ADVANCE LET ALONE TWO DAYS IN
ADVANCE...BUT THIS SEEMS LIKE A GOOD CASE FOR LAKE EFFECT FOG.
THE OTHER CONCERN IS THUNDERSTORM CHANCES. MODELS DEPICT A SOUTHERN
STREAM WAVE COMING UP FROM MEXICO MOVING INTO THE OH VALLEY THU.
THIS IS A LITTLE SLOWER THAN PREVIOUS MODEL RUNS AND MOST OF THE
ENERGY STAYS SOUTH TOWARDS THE OHIO VALLEY. THE OTHER AREA OF
POTENTIAL THUNDERSTORM DEVELOPMENT WOULD BE IN THE NORTHERN LAKES
TONIGHT AND SPREADING SOUTH THU ALONG THE FRONT. WILL GO WITH LOW
POPS HERE TONIGHT THROUGH THROUGH FRI.
GFS AND ECMWF BRING ANOTHER WAVE THROUGH THE REGION SAT-SUN MORNING
WHICH LOOKS LIKE A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS. THEN
MODELS CONTINUE TO DEVELOP A DEEP TROF OVER THE WESTERN US AND PUMP
UP THE RIDGE OVER THE EASTERN US SUN THROUGH THE MIDDLE OF NEXT
WEEK. EXPECT DRY AND UNSEASONABLY WARM WEATHER THROUGH THIS
PERIOD.
ALLSOPP
&&
.CLIMATE...
316 PM CDT
DAILY RECORD HIGHS AND RECORD WARM LOWS ARE IN JEOPARDY NEARLY
EVERY ONE OF THE NEXT 8 DAYS...SO RATHER THAN LIST EACH RECORD
HERE IS THE LINK TO THE RECORDS:
CHICAGO: HTTP://WWW.CRH.NOAA.GOV/LOT/?N=MARREC-ORD
(ALL LOWERCASE)
RFD: HTTP://WWW.CRH.NOAA.GOV/LOT/?N=MARREC-RFD
(ALL LOWERCASE)
IF CHICAGO REACHES 80 DEGREES ON WEDNESDAY IT WILL BE THE THIRD
EARLIEST 80 DEGREE DAY EVER IN CHICAGO. THE EARLIEST FIRST 80
DEGREE DAY WAS BACK ON MARCH 3RD 1974 AND THE SECOND EARLIEST WAS
BACK ON MARCH 12 1990. IN ROCKFORD...THE EARLIEST FIRST 80 DEGREE
DAY ON RECORD IS MARCH 23RD 1939...SO IF ROCKFORD WERE TO REACH
80 ON WEDNESDAY IT WOULD BE THE EARLIEST ON RECORD BREAKING THE
PREVIOUS RECORD EARLIEST BY OVER A WEEK.
RECORD HIGHS WED MARCH 14. CURRENT FORECAST BREAKS BOTH OF THESE.
CHICAGO 77
ROCKFORD 74
NORMAL NUMBER OF 70 DEGREE DAYS IN MARCH FOR BOTH CHICAGO AND
ROCKFORD IS 1.2.
RECORD NUMBER OF DAYS WITH MAX TEMP 70 OR ABOVE IN MARCH
CHICAGO 9 IN 1945...6 IN 1910 AND 1907.
ROCKFORD 11 IN 1910...7 IN 1945.
RECORD FOR CONSECUTIVE 70 DEGREE DAYS IN MARCH
CHICAGO...5 FROM MARCH 12-16 1995.
ROCKFORD...9 MARCH 23-31 1910.
ALLSOPP/IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SOUTH/SOUTHWEST WINDS. GUSTY THROUGH SUNSET.
* ISOLATED SHOWERS/TS POSSIBLE INTO THIS EVENING.
* FOG/LOW CEILING POTENTIAL OVERNIGHT INTO THURSDAY MORNING.
PAW
//DISCUSSION...UPDATED 18Z...
SURFACE FRONTAL SYSTEM APPROACHING FROM THE WEST THIS AFTERNOON.
LOW LEVEL MOISTURE INCREASING OVER NORTHERN IL AND NORTHWEST IN
AHEAD OF THE FRONT. AN UPPER LEVEL DISTURBANCE WILL LIFT ACROSS
THE AREA LATE THIS AFTERNOON AND EVENING. TYPICAL PARAMETERS IN
PLACE FOR SHOWERS AND THUNDERSTORMS...BUT LITTLE TO TRIGGER THE
CONVECTION. SO CONFIDENCE IS LOW IN ANYTHING OCCURRING AT THE
TERMINALS. THE BETTER CHANCE IS TO THE SOUTH AND SOUTHEAST.
MVFR CEILINGS PUSHING NORTHEAST THROUGH MO AND CENTRAL IL SHOULD
MAKE IT INTO THE TERMINALS THIS AFTERNOON. SOME BREAK UP OF THESE
CEILING THIS EVENING...BUT THEY WILL REDEVELOP AS THE FRONT GETS
CLOSE LATER TONIGHT. SOME LIGHT FOG MAY DEVELOP LATE TONIGHT AS
WINDS DIMINISH.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN WIND.
* LOW CONFIDENCE IN SHOWERS/TS INTO THIS EVENING.
* LOW CONFIDENCE IN FOG/LOW CIGS TONIGHT INTO THURSDAY MORNING.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT THROUGH SUNDAY...PREVAILING VFR...CHANCE TSRA
PRODUCING LOCAL MVFR TO IFR.
* MONDAY AND TUESDAY...VFR. CMS
&&
.MARINE...
207 PM CDT
PERSISTENT SOUTHERLY FLOW WILL CONTINUE OVER LAKE MICHIGAN INTO THIS
EVENING. A COLD FRONT WILL MOVE SOUTHEAST OVER THE NORTHERN PART OF
THE LAKE OVERNIGHT...AND THEN ADVANCE DOWN THE LAKE THURSDAY AS
THE COLD WATER TEMPERATURES AND ASSOCIATED PRESSURE DIFFERENCES
HELP TO DRIVE THE BOUNDARY SOUTH. THIS FRONT AND ASSOCIATED WIND
SHIFT TO THE NORTH NORTHEAST SHOULD ARRIVE IN THE ILLINOIS
NEARSHORE AREAS BY EARLY AFTERNOON THURSDAY AND THE INDIANA SHORE
BY MID AFTERNOON. WITH THIS FRONT WILL NOT ONLY COME A WIND SHIFT
AND A BRIEF INCREASE IN WIND SPEEDS...BUT ALSO THE LIKELIHOOD OF
FOG. SOME OF THIS FOG WILL POTENTIALLY BE DENSE...ESPECIALLY NEAR
THE FRONTAL BOUNDARY LATE TONIGHT INTO THURSDAY MORNING. THERE IS
A CHANCE OF PRECIPITATION WITH THIS FRONT...WITH THE POSSIBILITY
OF SCATTERED THUNDERSTORMS. BEYOND THURSDAY...SOUTHEAST WINDS WILL
RETURN FOR FRIDAY...BECOMING SOUTHERLY FOR THE WEEKEND AND THE
FIRST HALF OF NEXT WEEK AS THE ANOMALOUSLY WARM PATTERN CONTINUES.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
209 PM CDT WED MAR 14 2012
.DISCUSSION...
1136 AM CDT
GOING FORECAST FOR THIS AFTERNOON...INCLUDING RECORD
WARMTH...LOOKS GOOD. TEMPERATURES ALREADY ARE REACHING THE MID 70S
AT 1130 AM IN SOME PARTS OF THE FORECAST AREA. MIXING ON BOTH ILX
AND DVN SOUNDINGS WOULD PROVIDE LOWER 80S...EVEN MID 80S ON THE
LATTER. INCREASING DEW POINTS AND SOME CIRRUS/CU WILL LIKELY KEEP
VALUES BETWEEN 79 AND 82 ACROSS MOST OF THE CWA.
A SOMEWHAT NOISY UPSTREAM MID-LEVEL FLOW EXISTS PER WATER VAPOR
SATELLITE IMAGERY AND PROFILERS. THERE APPEARS TO BE A COUPLE
LOW AMPLITUDE SHORT WAVE RIPPLES APPROACHING IL FROM IA AND MO.
INSTABILITY IS ALSO ON THE INCREASE FROM THE SOUTHWEST...WITH THE
COMBINATION OF THIS AND THE AFOREMENTIONED SHORT WAVES GENERATING
AGITATED CU/ACCAS ACROSS EASTERN MO AND SOUTHWEST IL. THIS IS ON
THE LEADING EDGE OF MUCAPES AROUND 2000 J/KG AND ELEVATED MOISTURE
TRANSPORT. THIS LEADING GRADIENT IS EXPECTED TO PROPAGATE
NORTHEAST OVER THE FORECAST AREA LATER THIS AFTERNOON INTO THIS
EVENING. EXPLICIT CONVECTIVE MODELS SUCH AS THE HRRR AND WRF
INDICATE SOME SCATTERED CONVECTION DEVELOPING ACROSS DOWNSTATE IL
WORKING NORTHEAST INTO OR NEAR THE SOUTHEAST FORECAST AREA. THIS
SEEMS PLAUSIBLE GIVEN THE FORECAST STRONG INSTABILITY AND THE
AGITATED FLOW ALOFT.
THE LOW-LEVEL JET IS ALSO FORECAST TO INTENSITY THIS
EVENING...DRIVEN IN PART TO THE APPROACHING NORTHERN STREAM COLD
FRONT. THIS COULD AS WELL INDUCE SCATTERED THUNDERSTORM COVERAGE
FURTHER WEST AND NORTH. THIS INCLUDES OVERNIGHT...AS THE
CONVERGENCE OF THE FRONTAL BOUNDARY MOVES INTO THE REGION. THE
DEEP LAYER SHEAR FROM LATE AFTERNOON INTO TONIGHT IS FAIRLY
MARGINAL FOR WELL ORGANIZED STORMS...ON THE ORDER OF 20 TO 30 KTS.
SO THE POTENTIAL FOR ANY SEVERE STORMS WOULD SEEM A LITTLE BETTER
WHEN THE INSTABILITY IS ITS DEEPEST AND THE LOW-LEVEL JET NOSE IS
INTO OUR AREA...BASICALLY WITH THE EVENING CONVECTION ACROSS OUR
SOUTHEAST FORECAST AREA /IF IT CAN DEVELOP THIS FAR NORTH/...BUT
INSTABILITY IS MODEST ENOUGH THROUGH ALL OF TONIGHT ACROSS OUR
ENTIRE FORECAST AREA THAT IT WILL BE SOMETHING TO CONTINUE TO
MONITOR.
MTF
//PREV DISCUSSION...
314 AM CDT
ADJUSTMENTS TO TEMPERATURE FORECAST FOR LATE THU AND FRI THANKS TO
PNEUMONIA FRONT PUSHING DOWN LAKE MICHIGAN...THIS WILL BREAK THE
STRING OF 70 DEGREE DAYS FOR CHICAGO...OTHERWISE MILD WEATHER
THROUGH THE MIDDLE OF NEXT WEEK. OTHER CONCERN IS POTENTIAL FOR
THUNDERSTORMS...MAINLY THU THROUGH SAT NIGHT.
SHORT WAVE TROF MOVING THROUGH THE NORTHERN ROCKIES TOWARD HUDSON
BAY TODAY WITH BROAD SOUTHWEST FLOW OVER THE MIDWEST. AT THE
SURFACE...HIGH PRESSURE SETTLING OVER THE SOUTHEAST STATES. SURFACE
LOW ASSOCIATED WITH CANADIAN SHORT WAVE WILL DRAG A TRAILING COLD
FRONT/TROF THROUGH THE PLAINS TODAY AND INTO UPPER GREAT LAKES BY
TONIGHT. A STRONG PRESSURE GRADIENT WILL SET UP ACROSS
NORTHERN IL AND NORTHWEST IN TODAY. SOUTHWESTERLY WINDS WILL
TRANSPORT UNSEASONABLY WARM MOIST AIR INTO THE REGION. NAM
SOUNDINGS AND 925 MB TEMPS STILL SUPPORT UPPER 70S TO NEAR 80
TODAY.
THE FRONT SAGS SOUTH DOWN THE LAKE TONIGHT INTO THU MORNING.
NAM/SREF APPEAR TO HAVE A MUCH BETTER HANDLE ON HOW FAR SOUTH THE
FRONT SAGS AND ALSO THE LOW LEVEL THERMAL PROFILES FOR THU AND FRI.
WITH FRONT PUSHING DOWN THE LAKE THIS TIME OF YEAR...THE COLD HEAVY
AIR OVER THE LAKE HAS A TENDENCY TO PUSH FRONTS FURTHER SOUTH THAN
THE MODELS WOULD SUGGEST. SO WILL LEAN HEAVILY ON NAM/SREF FOR WINDS
AND TEMP TRENDS THU AND FRI. EXPECT TEMPERATURES IN THE 70S FOR
MUCH OF THE AREA AGAIN THU BUT AREAS NEAR LAKE MI WILL SEE
TEMPERATURES PLUMMET THROUGH THE AFTERNOON AS THE COLD LAKE AIR SPREADS
SOUTHWEST ACROSS NORTHERN IL AND NORTHWEST IN. THE AREA SHOULD
REMAIN IN EAST FLOW MUCH OF FRI MORNING BUT AS UPPER LEVEL RIDGE
REBUILDS AND SURFACE WINDS GRADUALLY TURN SOUTHEAST THEN
SOUTH...AREAS AWAY FROM THE LAKE SHOULD WARM UP INTO THE 70S.
MOS GUIDANCE SUGGESTING DENSE FOG DEVELOPING TONIGHT THROUGH THU
NIGHT BUT WE THINK MOS IS EXPECTING THE GROUND TO BE MUCH
COLDER/WETTER THIS TIME OF YEAR...AND ISNT QUITE SURE HOW TO
HANDLE 60 DEGREE DEWPOINTS IN MID MARCH. WILL LIKELY SEE FOG
DEVELOP OVER THE LAKE THIS AFTERNOON AS UNSEASONABLY HUMID AIR
SPREADS NORTH. COULD SEE THE FOG SPREAD INLAND THURSDAY AFTERNOON
AND EVENING AS THE COOL AIR MASS PUSHES INLAND. DIFFICULT ENOUGH
TO FORECAST FOG A FEW HOURS IN ADVANCE LET ALONE TWO DAYS IN
ADVANCE...BUT THIS SEEMS LIKE A GOOD CASE FOR LAKE EFFECT FOG.
THE OTHER CONCERN IS THUNDERSTORM CHANCES. MODELS DEPICT A SOUTHERN
STREAM WAVE COMING UP FROM MEXICO MOVING INTO THE OH VALLEY THU.
THIS IS A LITTLE SLOWER THAN PREVIOUS MODEL RUNS AND MOST OF THE
ENERGY STAYS SOUTH TOWARDS THE OHIO VALLEY. THE OTHER AREA OF
POTENTIAL THUNDERSTORM DEVELOPMENT WOULD BE IN THE NORTHERN LAKES
TONIGHT AND SPREADING SOUTH THU ALONG THE FRONT. WILL GO WITH LOW
POPS HERE TONIGHT THROUGH THROUGH FRI.
GFS AND ECMWF BRING ANOTHER WAVE THROUGH THE REGION SAT-SUN MORNING
WHICH LOOKS LIKE A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS. THEN
MODELS CONTINUE TO DEVELOP A DEEP TROF OVER THE WESTERN US AND PUMP
UP THE RIDGE OVER THE EASTERN US SUN THROUGH THE MIDDLE OF NEXT
WEEK. EXPECT DRY AND UNSEASONABLY WARM WEATHER THROUGH THIS
PERIOD.
ALLSOPP
&&
.CLIMATE...
316 PM CDT
DAILY RECORD HIGHS AND RECORD WARM LOWS ARE IN JEOPARDY NEARLY
EVERY ONE OF THE NEXT 8 DAYS...SO RATHER THAN LIST EACH RECORD
HERE IS THE LINK TO THE RECORDS:
CHICAGO: HTTP://WWW.CRH.NOAA.GOV/LOT/?N=MARREC-ORD
(ALL LOWERCASE)
RFD: HTTP://WWW.CRH.NOAA.GOV/LOT/?N=MARREC-RFD
(ALL LOWERCASE)
IF CHICAGO REACHES 80 DEGREES ON WEDNESDAY IT WILL BE THE THIRD
EARLIEST 80 DEGREE DAY EVER IN CHICAGO. THE EARLIEST FIRST 80
DEGREE DAY WAS BACK ON MARCH 3RD 1974 AND THE SECOND EARLIEST WAS
BACK ON MARCH 12 1990. IN ROCKFORD...THE EARLIEST FIRST 80 DEGREE
DAY ON RECORD IS MARCH 23RD 1939...SO IF ROCKFORD WERE TO REACH
80 ON WEDNESDAY IT WOULD BE THE EARLIEST ON RECORD BREAKING THE
PREVIOUS RECORD EARLIEST BY OVER A WEEK.
RECORD HIGHS WED MARCH 14. CURRENT FORECAST BREAKS BOTH OF THESE.
CHICAGO 77
ROCKFORD 74
NORMAL NUMBER OF 70 DEGREE DAYS IN MARCH FOR BOTH CHICAGO AND
ROCKFORD IS 1.2.
RECORD NUMBER OF DAYS WITH MAX TEMP 70 OR ABOVE IN MARCH
CHICAGO 9 IN 1945...6 IN 1910 AND 1907.
ROCKFORD 11 IN 1910...7 IN 1945.
RECORD FOR CONSECUTIVE 70 DEGREE DAYS IN MARCH
CHICAGO...5 FROM MARCH 12-16 1995.
ROCKFORD...9 MARCH 23-31 1910.
ALLSOPP/IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SOUTH/SOUTHWEST WINDS. OCCASIONAL GUSTS CONTINUING THROUGH SUNSET.
* ISOLATED SHOWERS/TS POSSIBLE FROM LATE AFTERNOON INTO TONIGHT.
* FOG/LOW CEILING POTENTIAL OVERNIGHT INTO THURSDAY MORNING.
PAW
//DISCUSSION...UPDATED 18Z...
SURFACE FRONTAL SYSTEM APPROACHING FROM THE WEST THIS AFTERNOON.
LOW LEVEL MOISTURE INCREASING OVER NORTHERN IL AND NORTHWEST IN
AHEAD OF THE FRONT. AN UPPER LEVEL DISTURBANCE WILL LIFT ACROSS
THE AREA LATE THIS AFTERNOON AND EVENING. TYPICAL PARAMETERS IN
PLACE FOR SHOWERS AND THUNDERSTORMS...BUT LITTLE TO TRIGGER THE
CONVECTION. SO CONFIDENCE IS LOW IN ANYTHING OCCURRING AT THE
TERMINALS. THE BETTER CHANCE IS TO THE SOUTH AND SOUTHEAST.
MVFR CEILINGS PUSHING NORTHEAST THROUGH MO AND CENTRAL IL SHOULD
MAKE IT INTO THE TERMINALS THIS AFTERNOON. SOME BREAK UP OF THESE
CEILING THIS EVENING...BUT THEY WILL REDEVELOP AS THE FRONT GETS
CLOSE LATER TONIGHT. SOME LIGHT FOG MAY DEVELOP LATE TONIGHT AS
WINDS DIMINISH.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN WIND.
* LOW CONFIDENCE IN SHOWERS/TS LATE AFTERNOON INTO TONIGHT.
* LOW CONFIDENCE IN FOG/LOW CIGS TONIGHT INTO THURSDAY MORNING.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT THROUGH SUNDAY...PREVAILING VFR...CHANCE TSRA
PRODUCING LOCAL MVFR TO IFR.
* MONDAY AND TUESDAY...VFR. CMS
&&
.MARINE...
207 PM CDT
PERSISTENT SOUTHERLY FLOW WILL CONTINUE OVER LAKE MICHIGAN INTO THIS
EVENING. A COLD FRONT WILL MOVE SOUTHEAST OVER THE NORTHERN PART OF
THE LAKE OVERNIGHT...AND THEN ADVANCE DOWN THE LAKE THURSDAY AS
THE COLD WATER TEMPERATURES AND ASSOCIATED PRESSURE DIFFERENCES
HELP TO DRIVE THE BOUNDARY SOUTH. THIS FRONT AND ASSOCIATED WIND
SHIFT TO THE NORTH NORTHEAST SHOULD ARRIVE IN THE ILLINOIS
NEARSHORE AREAS BY EARLY AFTERNOON THURSDAY AND THE INDIANA SHORE
BY MID AFTERNOON. WITH THIS FRONT WILL NOT ONLY COME A WIND SHIFT
AND A BRIEF INCREASE IN WIND SPEEDS...BUT ALSO THE LIKELIHOOD OF
FOG. SOME OF THIS FOG WILL POTENTIALLY BE DENSE...ESPECIALLY NEAR
THE FRONTAL BOUNDARY LATE TONIGHT INTO THURSDAY MORNING. THERE IS
A CHANCE OF PRECIPITATION WITH THIS FRONT...WITH THE POSSIBILITY
OF SCATTERED THUNDERSTORMS. BEYOND THURSDAY...SOUTHEAST WINDS WILL
RETURN FOR FRIDAY...BECOMING SOUTHERLY FOR THE WEEKEND AND THE
FIRST HALF OF NEXT WEEK AS THE ANOMALOUSLY WARM PATTERN CONTINUES.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1239 PM CDT WED MAR 14 2012
.DISCUSSION...
1136 AM CDT
GOING FORECAST FOR THIS AFTERNOON...INCLUDING RECORD
WARMTH...LOOKS GOOD. TEMPERATURES ALREADY ARE REACHING THE MID 70S
AT 1130 AM IN SOME PARTS OF THE FORECAST AREA. MIXING ON BOTH ILX
AND DVN SOUNDINGS WOULD PROVIDE LOWER 80S...EVEN MID 80S ON THE
LATTER. INCREASING DEW POINTS AND SOME CIRRUS/CU WILL LIKELY KEEP
VALUES BETWEEN 79 AND 82 ACROSS MOST OF THE CWA.
A SOMEWHAT NOISY UPSTREAM MID-LEVEL FLOW EXISTS PER WATER VAPOR
SATELLITE IMAGERY AND PROFILERS. THERE APPEARS TO BE A COUPLE
LOW AMPLITUDE SHORT WAVE RIPPLES APPROACHING IL FROM IA AND MO.
INSTABILITY IS ALSO ON THE INCREASE FROM THE SOUTHWEST...WITH THE
COMBINATION OF THIS AND THE AFOREMENTIONED SHORT WAVES GENERATING
AGITATED CU/ACCAS ACROSS EASTERN MO AND SOUTHWEST IL. THIS IS ON
THE LEADING EDGE OF MUCAPES AROUND 2000 J/KG AND ELEVATED MOISTURE
TRANSPORT. THIS LEADING GRADIENT IS EXPECTED TO PROPAGATE
NORTHEAST OVER THE FORECAST AREA LATER THIS AFTERNOON INTO THIS
EVENING. EXPLICIT CONVECTIVE MODELS SUCH AS THE HRRR AND WRF
INDICATE SOME SCATTERED CONVECTION DEVELOPING ACROSS DOWNSTATE IL
WORKING NORTHEAST INTO OR NEAR THE SOUTHEAST FORECAST AREA. THIS
SEEMS PLAUSIBLE GIVEN THE FORECAST STRONG INSTABILITY AND THE
AGITATED FLOW ALOFT.
THE LOW-LEVEL JET IS ALSO FORECAST TO INTENSITY THIS
EVENING...DRIVEN IN PART TO THE APPROACHING NORTHERN STREAM COLD
FRONT. THIS COULD AS WELL INDUCE SCATTERED THUNDERSTORM COVERAGE
FURTHER WEST AND NORTH. THIS INCLUDES OVERNIGHT...AS THE
CONVERGENCE OF THE FRONTAL BOUNDARY MOVES INTO THE REGION. THE
DEEP LAYER SHEAR FROM LATE AFTERNOON INTO TONIGHT IS FAIRLY
MARGINAL FOR WELL ORGANIZED STORMS...ON THE ORDER OF 20 TO 30 KTS.
SO THE POTENTIAL FOR ANY SEVERE STORMS WOULD SEEM A LITTLE BETTER
WHEN THE INSTABILITY IS ITS DEEPEST AND THE LOW-LEVEL JET NOSE IS
INTO OUR AREA...BASICALLY WITH THE EVENING CONVECTION ACROSS OUR
SOUTHEAST FORECAST AREA /IF IT CAN DEVELOP THIS FAR NORTH/...BUT
INSTABILITY IS MODEST ENOUGH THROUGH ALL OF TONIGHT ACROSS OUR
ENTIRE FORECAST AREA THAT IT WILL BE SOMETHING TO CONTINUE TO
MONITOR.
MTF
//PREV DISCUSSION...
314 AM CDT
ADJUSTMENTS TO TEMPERATURE FORECAST FOR LATE THU AND FRI THANKS TO
PNEUMONIA FRONT PUSHING DOWN LAKE MICHIGAN...THIS WILL BREAK THE
STRING OF 70 DEGREE DAYS FOR CHICAGO...OTHERWISE MILD WEATHER
THROUGH THE MIDDLE OF NEXT WEEK. OTHER CONCERN IS POTENTIAL FOR
THUNDERSTORMS...MAINLY THU THROUGH SAT NIGHT.
SHORT WAVE TROF MOVING THROUGH THE NORTHERN ROCKIES TOWARD HUDSON
BAY TODAY WITH BROAD SOUTHWEST FLOW OVER THE MIDWEST. AT THE
SURFACE...HIGH PRESSURE SETTLING OVER THE SOUTHEAST STATES. SURFACE
LOW ASSOCIATED WITH CANADIAN SHORT WAVE WILL DRAG A TRAILING COLD
FRONT/TROF THROUGH THE PLAINS TODAY AND INTO UPPER GREAT LAKES BY
TONIGHT. A STRONG PRESSURE GRADIENT WILL SET UP ACROSS
NORTHERN IL AND NORTHWEST IN TODAY. SOUTHWESTERLY WINDS WILL
TRANSPORT UNSEASONABLY WARM MOIST AIR INTO THE REGION. NAM
SOUNDINGS AND 925 MB TEMPS STILL SUPPORT UPPER 70S TO NEAR 80
TODAY.
THE FRONT SAGS SOUTH DOWN THE LAKE TONIGHT INTO THU MORNING.
NAM/SREF APPEAR TO HAVE A MUCH BETTER HANDLE ON HOW FAR SOUTH THE
FRONT SAGS AND ALSO THE LOW LEVEL THERMAL PROFILES FOR THU AND FRI.
WITH FRONT PUSHING DOWN THE LAKE THIS TIME OF YEAR...THE COLD HEAVY
AIR OVER THE LAKE HAS A TENDENCY TO PUSH FRONTS FURTHER SOUTH THAN
THE MODELS WOULD SUGGEST. SO WILL LEAN HEAVILY ON NAM/SREF FOR WINDS
AND TEMP TRENDS THU AND FRI. EXPECT TEMPERATURES IN THE 70S FOR
MUCH OF THE AREA AGAIN THU BUT AREAS NEAR LAKE MI WILL SEE
TEMPERATURES PLUMMET THROUGH THE AFTERNOON AS THE COLD LAKE AIR SPREADS
SOUTHWEST ACROSS NORTHERN IL AND NORTHWEST IN. THE AREA SHOULD
REMAIN IN EAST FLOW MUCH OF FRI MORNING BUT AS UPPER LEVEL RIDGE
REBUILDS AND SURFACE WINDS GRADUALLY TURN SOUTHEAST THEN
SOUTH...AREAS AWAY FROM THE LAKE SHOULD WARM UP INTO THE 70S.
MOS GUIDANCE SUGGESTING DENSE FOG DEVELOPING TONIGHT THROUGH THU
NIGHT BUT WE THINK MOS IS EXPECTING THE GROUND TO BE MUCH
COLDER/WETTER THIS TIME OF YEAR...AND ISNT QUITE SURE HOW TO
HANDLE 60 DEGREE DEWPOINTS IN MID MARCH. WILL LIKELY SEE FOG
DEVELOP OVER THE LAKE THIS AFTERNOON AS UNSEASONABLY HUMID AIR
SPREADS NORTH. COULD SEE THE FOG SPREAD INLAND THURSDAY AFTERNOON
AND EVENING AS THE COOL AIR MASS PUSHES INLAND. DIFFICULT ENOUGH
TO FORECAST FOG A FEW HOURS IN ADVANCE LET ALONE TWO DAYS IN
ADVANCE...BUT THIS SEEMS LIKE A GOOD CASE FOR LAKE EFFECT FOG.
THE OTHER CONCERN IS THUNDERSTORM CHANCES. MODELS DEPICT A SOUTHERN
STREAM WAVE COMING UP FROM MEXICO MOVING INTO THE OH VALLEY THU.
THIS IS A LITTLE SLOWER THAN PREVIOUS MODEL RUNS AND MOST OF THE
ENERGY STAYS SOUTH TOWARDS THE OHIO VALLEY. THE OTHER AREA OF
POTENTIAL THUNDERSTORM DEVELOPMENT WOULD BE IN THE NORTHERN LAKES
TONIGHT AND SPREADING SOUTH THU ALONG THE FRONT. WILL GO WITH LOW
POPS HERE TONIGHT THROUGH THROUGH FRI.
GFS AND ECMWF BRING ANOTHER WAVE THROUGH THE REGION SAT-SUN MORNING
WHICH LOOKS LIKE A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS. THEN
MODELS CONTINUE TO DEVELOP A DEEP TROF OVER THE WESTERN US AND PUMP
UP THE RIDGE OVER THE EASTERN US SUN THROUGH THE MIDDLE OF NEXT
WEEK. EXPECT DRY AND UNSEASONABLY WARM WEATHER THROUGH THIS
PERIOD.
ALLSOPP
&&
.CLIMATE...
316 PM CDT
DAILY RECORD HIGHS AND RECORD WARM LOWS ARE IN JEOPARDY NEARLY
EVERY ONE OF THE NEXT 8 DAYS...SO RATHER THAN LIST EACH RECORD
HERE IS THE LINK TO THE RECORDS:
CHICAGO: HTTP://WWW.CRH.NOAA.GOV/LOT/?N=MARREC-ORD
(ALL LOWERCASE)
RFD: HTTP://WWW.CRH.NOAA.GOV/LOT/?N=MARREC-RFD
(ALL LOWERCASE)
IF CHICAGO REACHES 80 DEGREES ON WEDNESDAY IT WILL BE THE THIRD
EARLIEST 80 DEGREE DAY EVER IN CHICAGO. THE EARLIEST FIRST 80
DEGREE DAY WAS BACK ON MARCH 3RD 1974 AND THE SECOND EARLIEST WAS
BACK ON MARCH 12 1990. IN ROCKFORD...THE EARLIEST FIRST 80 DEGREE
DAY ON RECORD IS MARCH 23RD 1939...SO IF ROCKFORD WERE TO REACH
80 ON WEDNESDAY IT WOULD BE THE EARLIEST ON RECORD BREAKING THE
PREVIOUS RECORD EARLIEST BY OVER A WEEK.
RECORD HIGHS WED MARCH 14. CURRENT FORECAST BREAKS BOTH OF THESE.
CHICAGO 77
ROCKFORD 74
NORMAL NUMBER OF 70 DEGREE DAYS IN MARCH FOR BOTH CHICAGO AND
ROCKFORD IS 1.2.
RECORD NUMBER OF DAYS WITH MAX TEMP 70 OR ABOVE IN MARCH
CHICAGO 9 IN 1945...6 IN 1910 AND 1907.
ROCKFORD 11 IN 1910...7 IN 1945.
RECORD FOR CONSECUTIVE 70 DEGREE DAYS IN MARCH
CHICAGO...5 FROM MARCH 12-16 1995.
ROCKFORD...9 MARCH 23-31 1910.
ALLSOPP/IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SOUTH/SOUTHWEST WINDS. OCCASIONAL GUSTS CONTINUING THROUGH SUNSET.
* ISOLATED SHOWERS/TS POSSIBLE FROM LATE AFTERNOON INTO TONIGHT.
* FOG/LOW CEILING POTENTIAL OVERNIGHT INTO THURSDAY MORNING.
PAW
//DISCUSSION...UPDATED 18Z...
SURFACE FRONTAL SYSTEM APPROACHING FROM THE WEST THIS AFTERNOON.
LOW LEVEL MOISTURE INCREASING OVER NORTHERN IL AND NORTHWEST IN
AHEAD OF THE FRONT. AN UPPER LEVEL DISTURBANCE WILL LIFT ACROSS
THE AREA LATE THIS AFTERNOON AND EVENING. TYPICAL PARAMETERS IN
PLACE FOR SHOWERS AND THUNDERSTORMS...BUT LITTLE TO TRIGGER THE
CONVECTION. SO CONFIDENCE IS LOW IN ANYTHING OCCURRING AT THE
TERMINALS. THE BETTER CHANCE IS TO THE SOUTH AND SOUTHEAST.
MVFR CEILINGS PUSHING NORTHEAST THROUGH MO AND CENTRAL IL SHOULD
MAKE IT INTO THE TERMINALS THIS AFTERNOON. SOME BREAK UP OF THESE
CEILING THIS EVENING...BUT THEY WILL REDEVELOP AS THE FRONT GETS
CLOSE LATER TONIGHT. SOME LIGHT FOG MAY DEVELOP LATE TONIGHT AS
WINDS DIMINISH.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN WIND.
* LOW CONFIDENCE IN SHOWERS/TS LATE AFTERNOON INTO TONIGHT.
* LOW CONFIDENCE IN FOG/LOW CIGS TONIGHT INTO THURSDAY MORNING.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT THROUGH SUNDAY...PREVAILING VFR...CHANCE TSRA
PRODUCING LOCAL MVFR TO IFR.
* MONDAY AND TUESDAY...VFR. CMS
&&
.MARINE...
308 AM...LOW PRESSURE ACROSS CENTRAL CANADA WILL MOVE NORTHEAST
ACROSS HUDSON BAY TONIGHT. THE GRADIENT TIGHTENS SOME AND EXPECT
WINDS TO INCREASE INTO THE 15-25 KT RANGE BUT EXPECT A COLD AND
STABLE MARINE LAYER TO LIMIT WAVE HEIGHTS.
A TRAILING COLD FRONT FROM THIS LOW WILL MOVE ACROSS NORTHERN LAKE
MICHIGAN LATE TONIGHT AND CONTINUE SOUTH ACROSS THE LAKE THURSDAY...
REACHING FAR SOUTHERN LAKE MICHIGAN BY LATE THURSDAY AFTERNOON.
WIND SPEEDS/GUSTS BEHIND THIS FRONT ARE A BIT PROBLEMATIC. MODELS
SUGGEST A WEAK LOW DEVELOPING OVER NORTHERN IL...ALONG THE FRONT
WHILE STRENGTHENING HIGH PRESSURE MOVES ACROSS LAKE SUPERIOR. IF
THIS OCCURS...COULD BE A RATHER TIGHT GRADIENT ALONG THE FRONT AND
A PERIOD OF 15-25KTS IS CERTAINLY POSSIBLE. BOTH THE LOW AND THE
HIGH WEAKEN THURSDAY...SO WIND SPEEDS BEHIND THE FRONT SHOULD
DIMINISH AS IT PUSHES SOUTH. GRADIENT THEN BECOMES MESSY BUT WEAK
THURSDAY NIGHT INTO FRIDAY AND EXPECT LIGHT NORTHERLY WINDS TO
TURN LIGHT SOUTH OR SOUTHEASTERLY.
ONE OTHER CONCERN IS POTENTIAL FOR DENSE FOG. AS WARMER AND MORE
MOIST AIR ADVECTS OVER THE COLDER WATERS...EXPECT TO SEE SOME FOG
DEVELOPMENT TODAY. HAVE HIGHER CONFIDENCE THAT THE FOG WILL BECOME
DENSE BEHIND THE FRONT BUT NOT CONFIDENT TO HOIST ANY DENSE FOG
ADVISORIES YET...BUT THAT IS SOMETHING THAT WILL NEED TO BE
MONITORED LATER TODAY AND ESPECIALLY TONIGHT. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
1139 AM CDT WED MAR 14 2012
.DISCUSSION...
1136 AM CDT
GOING FORECAST FOR THIS AFTERNOON...INCLUDING RECORD
WARMTH...LOOKS GOOD. TEMPERATURES ALREADY ARE REACHING THE MID 70S
AT 1130 AM IN SOME PARTS OF THE FORECAST AREA. MIXING ON BOTH ILX
AND DVN SOUNDINGS WOULD PROVIDE LOWER 80S...EVEN MID 80S ON THE
LATTER. INCREASING DEW POINTS AND SOME CIRRUS/CU WILL LIKELY KEEP
VALUES BETWEEN 79 AND 82 ACROSS MOST OF THE CWA.
A SOMEWHAT NOISY UPSTREAM MID-LEVEL FLOW EXISTS PER WATER VAPOR
SATELLITE IMAGERY AND PROFILERS. THERE APPEARS TO BE A COUPLE
LOW AMPLITUDE SHORT WAVE RIPPLES APPROACHING IL FROM IA AND MO.
INSTABILITY IS ALSO ON THE INCREASE FROM THE SOUTHWEST...WITH THE
COMBINATION OF THIS AND THE AFOREMENTIONED SHORT WAVES GENERATING
AGITATED CU/ACCAS ACROSS EASTERN MO AND SOUTHWEST IL. THIS IS ON
THE LEADING EDGE OF MUCAPES AROUND 2000 J/KG AND ELEVATED MOISTURE
TRANSPORT. THIS LEADING GRADIENT IS EXPECTED TO PROPAGATE
NORTHEAST OVER THE FORECAST AREA LATER THIS AFTERNOON INTO THIS
EVENING. EXPLICIT CONVECTIVE MODELS SUCH AS THE HRRR AND WRF
INDICATE SOME SCATTERED CONVECTION DEVELOPING ACROSS DOWNSTATE IL
WORKING NORTHEAST INTO OR NEAR THE SOUTHEAST FORECAST AREA. THIS
SEEMS PLAUSIBLE GIVEN THE FORECAST STRONG INSTABILITY AND THE
AGITATED FLOW ALOFT.
THE LOW-LEVEL JET IS ALSO FORECAST TO INTENSITY THIS
EVENING...DRIVEN IN PART TO THE APPROACHING NORTHERN STREAM COLD
FRONT. THIS COULD AS WELL INDUCE SCATTERED THUNDERSTORM COVERAGE
FURTHER WEST AND NORTH. THIS INCLUDES OVERNIGHT...AS THE
CONVERGENCE OF THE FRONTAL BOUNDARY MOVES INTO THE REGION. THE
DEEP LAYER SHEAR FROM LATE AFTERNOON INTO TONIGHT IS FAIRLY
MARGINAL FOR WELL ORGANIZED STORMS...ON THE ORDER OF 20 TO 30 KTS.
SO THE POTENTIAL FOR ANY SEVERE STORMS WOULD SEEM A LITTLE BETTER
WHEN THE INSTABILITY IS ITS DEEPEST AND THE LOW-LEVEL JET NOSE IS
INTO OUR AREA...BASICALLY WITH THE EVENING CONVECTION ACROSS OUR
SOUTHEAST FORECAST AREA /IF IT CAN DEVELOP THIS FAR NORTH/...BUT
INSTABILITY IS MODEST ENOUGH THROUGH ALL OF TONIGHT ACROSS OUR
ENTIRE FORECAST AREA THAT IT WILL BE SOMETHING TO CONTINUE TO
MONITOR.
MTF
&&
.PREV DISCUSSION...
314 AM CDT
ADJUSTMENTS TO TEMPERATURE FORECAST FOR LATE THU AND FRI THANKS TO
PNEUMONIA FRONT PUSHING DOWN LAKE MICHIGAN...THIS WILL BREAK THE
STRING OF 70 DEGREE DAYS FOR CHICAGO...OTHERWISE MILD WEATHER
THROUGH THE MIDDLE OF NEXT WEEK. OTHER CONCERN IS POTENTIAL FOR
THUNDERSTORMS...MAINLY THU THROUGH SAT NIGHT.
SHORT WAVE TROF MOVING THROUGH THE NORTHERN ROCKIES TOWARD HUDSON
BAY TODAY WITH BROAD SOUTHWEST FLOW OVER THE MIDWEST. AT THE
SURFACE...HIGH PRESSURE SETTLING OVER THE SOUTHEAST STATES. SURFACE
LOW ASSOCIATED WITH CANADIAN SHORT WAVE WILL DRAG A TRAILING COLD
FRONT/TROF THROUGH THE PLAINS TODAY AND INTO UPPER GREAT LAKES BY
TONIGHT. A STRONG PRESSURE GRADIENT WILL SET UP ACROSS
NORTHERN IL AND NORTHWEST IN TODAY. SOUTHWESTERLY WINDS WILL
TRANSPORT UNSEASONABLY WARM MOIST AIR INTO THE REGION. NAM
SOUNDINGS AND 925 MB TEMPS STILL SUPPORT UPPER 70S TO NEAR 80
TODAY.
THE FRONT SAGS SOUTH DOWN THE LAKE TONIGHT INTO THU MORNING.
NAM/SREF APPEAR TO HAVE A MUCH BETTER HANDLE ON HOW FAR SOUTH THE
FRONT SAGS AND ALSO THE LOW LEVEL THERMAL PROFILES FOR THU AND FRI.
WITH FRONT PUSHING DOWN THE LAKE THIS TIME OF YEAR...THE COLD HEAVY
AIR OVER THE LAKE HAS A TENDENCY TO PUSH FRONTS FURTHER SOUTH THAN
THE MODELS WOULD SUGGEST. SO WILL LEAN HEAVILY ON NAM/SREF FOR WINDS
AND TEMP TRENDS THU AND FRI. EXPECT TEMPERATURES IN THE 70S FOR
MUCH OF THE AREA AGAIN THU BUT AREAS NEAR LAKE MI WILL SEE
TEMPERATURES PLUMMET THROUGH THE AFTERNOON AS THE COLD LAKE AIR SPREADS
SOUTHWEST ACROSS NORTHERN IL AND NORTHWEST IN. THE AREA SHOULD
REMAIN IN EAST FLOW MUCH OF FRI MORNING BUT AS UPPER LEVEL RIDGE
REBUILDS AND SURFACE WINDS GRADUALLY TURN SOUTHEAST THEN
SOUTH...AREAS AWAY FROM THE LAKE SHOULD WARM UP INTO THE 70S.
MOS GUIDANCE SUGGESTING DENSE FOG DEVELOPING TONIGHT THROUGH THU
NIGHT BUT WE THINK MOS IS EXPECTING THE GROUND TO BE MUCH
COLDER/WETTER THIS TIME OF YEAR...AND ISNT QUITE SURE HOW TO
HANDLE 60 DEGREE DEWPOINTS IN MID MARCH. WILL LIKELY SEE FOG
DEVELOP OVER THE LAKE THIS AFTERNOON AS UNSEASONABLY HUMID AIR
SPREADS NORTH. COULD SEE THE FOG SPREAD INLAND THURSDAY AFTERNOON
AND EVENING AS THE COOL AIR MASS PUSHES INLAND. DIFFICULT ENOUGH
TO FORECAST FOG A FEW HOURS IN ADVANCE LET ALONE TWO DAYS IN
ADVANCE...BUT THIS SEEMS LIKE A GOOD CASE FOR LAKE EFFECT FOG.
THE OTHER CONCERN IS THUNDERSTORM CHANCES. MODELS DEPICT A SOUTHERN
STREAM WAVE COMING UP FROM MEXICO MOVING INTO THE OH VALLEY THU.
THIS IS A LITTLE SLOWER THAN PREVIOUS MODEL RUNS AND MOST OF THE
ENERGY STAYS SOUTH TOWARDS THE OHIO VALLEY. THE OTHER AREA OF
POTENTIAL THUNDERSTORM DEVELOPMENT WOULD BE IN THE NORTHERN LAKES
TONIGHT AND SPREADING SOUTH THU ALONG THE FRONT. WILL GO WITH LOW
POPS HERE TONIGHT THROUGH THROUGH FRI.
GFS AND ECMWF BRING ANOTHER WAVE THROUGH THE REGION SAT-SUN MORNING
WHICH LOOKS LIKE A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS. THEN
MODELS CONTINUE TO DEVELOP A DEEP TROF OVER THE WESTERN US AND PUMP
UP THE RIDGE OVER THE EASTERN US SUN THROUGH THE MIDDLE OF NEXT
WEEK. EXPECT DRY AND UNSEASONABLY WARM WEATHER THROUGH THIS
PERIOD.
ALLSOPP
&&
.CLIMATE...
316 PM CDT
DAILY RECORD HIGHS AND RECORD WARM LOWS ARE IN JEOPARDY NEARLY
EVERY ONE OF THE NEXT 8 DAYS...SO RATHER THAN LIST EACH RECORD
HERE IS THE LINK TO THE RECORDS:
CHICAGO: HTTP://WWW.CRH.NOAA.GOV/LOT/?N=MARREC-ORD
(ALL LOWERCASE)
RFD: HTTP://WWW.CRH.NOAA.GOV/LOT/?N=MARREC-RFD
(ALL LOWERCASE)
IF CHICAGO REACHES 80 DEGREES ON WEDNESDAY IT WILL BE THE THIRD
EARLIEST 80 DEGREE DAY EVER IN CHICAGO. THE EARLIEST FIRST 80
DEGREE DAY WAS BACK ON MARCH 3RD 1974 AND THE SECOND EARLIEST WAS
BACK ON MARCH 12 1990. IN ROCKFORD...THE EARLIEST FIRST 80 DEGREE
DAY ON RECORD IS MARCH 23RD 1939...SO IF ROCKFORD WERE TO REACH
80 ON WEDNESDAY IT WOULD BE THE EARLIEST ON RECORD BREAKING THE
PREVIOUS RECORD EARLIEST BY OVER A WEEK.
RECORD HIGHS WED MARCH 14. CURRENT FORECAST BREAKS BOTH OF THESE.
CHICAGO 77
ROCKFORD 74
NORMAL NUMBER OF 70 DEGREE DAYS IN MARCH FOR BOTH CHICAGO AND
ROCKFORD IS 1.2.
RECORD NUMBER OF DAYS WITH MAX TEMP 70 OR ABOVE IN MARCH
CHICAGO 9 IN 1945...6 IN 1910 AND 1907.
ROCKFORD 11 IN 1910...7 IN 1945.
RECORD FOR CONSECUTIVE 70 DEGREE DAYS IN MARCH
CHICAGO...5 FROM MARCH 12-16 1995.
ROCKFORD...9 MARCH 23-31 1910.
ALLSOPP/IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* SOUTH/SOUTHWEST WINDS. GUSTS BECOMING MORE FREQUENT BY LATE
MORNING AND CONTINUING THROUGH SUNSET.
* ISOLATED SHOWERS/TS POSSIBLE FROM LATE AFTERNOON INTO TONIGHT.
* FOG/LOW CEILING POTENTIAL OVERNIGHT INTO THURSDAY MORNING.
PAW
//DISCUSSION...UPDATED 12Z...
PRECIP POTENTIAL FOR LATER THIS AFTERNOON INTO TONIGHT IS RATHER
UNCERTAIN AND CONFIDENCE IS LOW. ALL OF THE MODELS SHOW A WEAK
UPPER LEVEL DISTURBANCE LIFTING NORTHEAST ACROSS CENTRAL IL THIS
AFTERNOON AND ACROSS NORTHWEST INDIANA THIS EVENING. LOW LEVEL
MOISTURE WILL CONTINUE TO INCREASE DURING THE DAY AND WITH TEMPS
EXPECTED TO BE IN THE UPPER 70S AND DEWPOINTS IN THE MID/UPPER
50S...THERE WILL BE PLENTY OF INSTABILITY. QUESTION IS WHAT WILL
TRIGGER ANY CONVECTION/SHOWERS/TS. WHILE ISOLATED ACTIVITY IS
POSSIBLE...TOWARD 00Z...ONLY FEEL CONFIDENT ENOUGH TO INCLUDE A
VCSH AT GYY. TRENDS WILL NEED TO BE MONITORED THROUGH THE DAY.
SOUTHERLY WINDS WILL CONTINUE TO SLOWLY INCREASE THROUGH THE
MORNING HRS AS THE GRADIENT TIGHTENS. ONCE THE LOW LEVELS BEGIN
TO MIX LATE THIS MORNING INTO EARLY THIS AFTERNOON...EXPECT WIND
GUSTS TO INCREASE INTO THE MID 20KT RANGE...THEN DIMINISHING
QUICKLY WITH SUNSET.
LOW CIGS CONTINUE TO DEVELOP OVER THE SOUTHERN PLAINS/ARKLATEX
REGION THIS MORNING. THESE WILL CONTINUE TO SPREAD NORTHEAST AND
INITIALLY EXPECT A SCT/BKN VFR CU FIELD TO DEVELOP TODAY BUT WITH
TIME THESE CIGS MAY LOWER INTO MVFR THIS EVENING OR MORE LIKELY
TONIGHT. GUIDANCE CONTINUES TO SUGGEST POTENTIAL FOR DENSE FOG AS
EARLY AS THIS EVENING AND CONTINUING INTO THURSDAY MORNING. AS
NOTED AT 06Z HOWEVER...SUSPECT THE MODELS MAY BE HAVING
DIFFICULTIES WITH THE NEAR RECORD HIGH TEMPERATURES ALONG WITH THE
HIGH DEWPOINTS...AND WHAT SHOULD BE A COLD AND POSSIBLY FROZEN
GROUND FOR MID MARCH. AS WINDS DIMINISH OVERNIGHT AND TEMPS DIP
TOWARD THE DEWPOINTS...EXPECT SOME LIGHT/MVFR FOG...BUT STILL NOT
SURE HOW WIDESPREAD OR DENSE IT MAY BECOME AND THIS TOO WILL NEED
TO BE MONITORED LATER THIS EVENING INTO TONIGHT. CMS
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM CONFIDENCE IN WIND.
* LOW CONFIDENCE IN SHOWERS/TS LATE AFTERNOON INTO TONIGHT.
* LOW CONFIDENCE IN FOG/LOW CIGS TONIGHT INTO THURSDAY MORNING.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT THROUGH SUNDAY...PREVAILING VFR...CHANCE TSRA
PRODUCING LOCAL MVFR TO IFR.
* MONDAY AND TUESDAY...VFR. CMS
&&
.MARINE...
308 AM...LOW PRESSURE ACROSS CENTRAL CANADA WILL MOVE NORTHEAST
ACROSS HUDSON BAY TONIGHT. THE GRADIENT TIGHTENS SOME AND EXPECT
WINDS TO INCREASE INTO THE 15-25 KT RANGE BUT EXPECT A COLD AND
STABLE MARINE LAYER TO LIMIT WAVE HEIGHTS.
A TRAILING COLD FRONT FROM THIS LOW WILL MOVE ACROSS NORTHERN LAKE
MICHIGAN LATE TONIGHT AND CONTINUE SOUTH ACROSS THE LAKE THURSDAY...
REACHING FAR SOUTHERN LAKE MICHIGAN BY LATE THURSDAY AFTERNOON.
WIND SPEEDS/GUSTS BEHIND THIS FRONT ARE A BIT PROBLEMATIC. MODELS
SUGGEST A WEAK LOW DEVELOPING OVER NORTHERN IL...ALONG THE FRONT
WHILE STRENGTHENING HIGH PRESSURE MOVES ACROSS LAKE SUPERIOR. IF
THIS OCCURS...COULD BE A RATHER TIGHT GRADIENT ALONG THE FRONT AND
A PERIOD OF 15-25KTS IS CERTAINLY POSSIBLE. BOTH THE LOW AND THE
HIGH WEAKEN THURSDAY...SO WIND SPEEDS BEHIND THE FRONT SHOULD
DIMINISH AS IT PUSHES SOUTH. GRADIENT THEN BECOMES MESSY BUT WEAK
THURSDAY NIGHT INTO FRIDAY AND EXPECT LIGHT NORTHERLY WINDS TO
TURN LIGHT SOUTH OR SOUTHEASTERLY.
ONE OTHER CONCERN IS POTENTIAL FOR DENSE FOG. AS WARMER AND MORE
MOIST AIR ADVECTS OVER THE COLDER WATERS...EXPECT TO SEE SOME FOG
DEVELOPMENT TODAY. HAVE HIGHER CONFIDENCE THAT THE FOG WILL BECOME
DENSE BEHIND THE FRONT BUT NOT CONFIDENT TO HOIST ANY DENSE FOG
ADVISORIES YET...BUT THAT IS SOMETHING THAT WILL NEED TO BE
MONITORED LATER TODAY AND ESPECIALLY TONIGHT. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
254 PM EDT WED MAR 14 2012
.SHORT TERM.../TONIGHT THROUGH THURSDAY NIGHT/
MAIN FOCUS WILL BE ON CONVECTIVE CHANCES THROUGH THE PERIOD AS WELL
AS CONTINUATION OF UNSEASONABLE WARM TEMPERATURES.
AS EXPECTED...TEMPERATURES HAVE SOARED WELL INTO THE 70S THIS
AFTERNOON WITH INCREASING LL FLOW AND STRONG MIXING. ELEVATED MIXED
LAYER IS KEEPING CLOUDS AT BAY FOR THE TIME BEING ACROSS MUCH OF THE
REGION. AS WE PROGRESS INTO THIS EVENING...THIS WILL CHANGE AS NOSE
OF LL THETA E SURGE AND INCREASING ISENTROPIC LIFT MOVES ACROSS
INDIANA INTO OHIO. LOCAL WRF MOST AGGRESSIVE WITH THIS FEATURE
FORCING CONVECTION TO INITIATE BY LATE AFTERNOON TO OUR WEST AND
SWINGING IT THROUGH THE AREA THROUGH MIDNIGHT. NAM KEEP ACTIVITY
SUPPRESSED FURTHER SOUTH. MIDDLE ROAD MODELS (HRRR/4KM SPC WRF) ALSO
FOCUS BULK OF CONVECTION ACROSS CNTRL/SOUTHERN INDIANA WITH
ISOL/WIDELY SCT CONVECTION INTO PORTIONS OF NORTHERN INDIANA. VIS
SAT SHOWS EXPANDING CU FIELD ACROSS CENTRAL ILLINOIS WHERE SFC
DEWPTS WERE NOW IN THE LOWER 60S. AT 18Z...ISOLATED SHOWERS WERE
NOTED SOUTHWEST OF ST LOUIS...WITH A FEW LIGHTNING STRIKES SHOWING
UP IN THE BOOTHILL OF MISSOURI...WHICH 14-15ZZ HRRR AND 12Z 4KM SPC
WRF PLACED PERFECTLY...WITH NAM SHOWING NO DEVELOPMENT. THE
LIGHTNING STRIKES WERE NOTED ON NOSE OF MID 60 DEWPTS. AM INCLINED
TO LEAN TOWARDS THESE MODELS AND THEIR TRENDS...WHICH BLEND NICELY
WITH INHERITED GRIDS. SPC HAS CONFINED SLGT RISK FURTHER SOUTH INTO
SOUTHERN ILLINOIS AND SW INDIANA. WILL NEED TO MONITOR CONVECTIVE
DEVELOPMENT INTO THIS EVENING WITH RISK OF STRONG STORMS IN PLACE.
WITH THE INCREASE IN LL MSTR...GRIDS NEEDED TO BE PATCHED UP TO
INCREASE OVERNIGHT LOWS CLOSER TO 60...AS WELL AS SUBSEQUENT
INCREASING IN DEWPTS. FOG POTENTIAL STILL LOOMS LATER TONIGHT AS
WEAK BOUNDARY SLIDES SOUTH TOWARDS THE AREA. HOWEVER...WITH
POTENTIAL OF EVENING CONVECTION AND CHANCES IT COULD MESS UP LL
PROFILES...WILL NOT MAKE ANY CHANGES IN REGARDS TO PREV INSERTION OF
FOG.
BOUNDARY WILL STALL OUT ACROSS THE AREA THURSDAY INTO THURSDAY
EVENING PUSHING SOUTHWARD. THIS WILL CAUSE NUMEROUS ISSUES WITH THE
FORECAST WITH POTENTIAL FOR WIDESPREAD CLOUD COVER...POSSIBLY FOG
AND CHANCES FOR SHOWERS AND STORMS. BROADBRUSHED APPROACH BEST
OPTION AT THIS POINT WITH DECREASE IN POPS IN NW AREAS BY THURS NGT
AS DRIER AIR TRIES TO FILTER IN. CAN`T REALLY ADD MUCH DETAIL TO
GRIDS AT THIS POINT WITH SEVERAL SCENARIOS POSSIBLE. UNSEASONABLY
WARM TEMPS WILL STILL BE IN STORE WITH HIGHS INTO THE 70S.
&&
.LONG TERM...
FEW CHANGES TO LONG TERM GRIDS WITH CRALLBLEND INIT IN BALLPARK.
UNSEASONABLY WARM PATTERN CONTINUES THROUGH THE PERIOD WITH DEEP
TROUGH DEVELOPING IN THE WEST AND STAUNCH RIDGE FOR LATE MARCH
DEVELOPING OVER THE MIDWEST. MEDIUM RANGE MODELS HAVE DIFFERENCES IN
THE DETAILS AS EXPECTED WITH NUMEROUS SHORT WAVES AND ABUNDANT
MOISTURE. PWATS STILL EXPECTED ABOVE AN INCH THROUGH THE PERIOD WITH
SURFACE DEWPOINTS IN THE 50S AND POOLING INTO 60S AT TIMES. THIS
WILL SET STAGE FOR PERIODS OF SHOWERS AND THUNDERSTORMS DEPENDENT ON
TIMING OF EACH WAVE. SHEAR PROFILES REMAIN WEAK WHILE MUCAPES ABOVE
2000 J/KG AT TIMES SO ISOLATED SEVERE STORMS REMAIN A POSSIBILITY.
TEMPERATURES WILL REMAIN 20 TO 25 DEGREES ABOVE NORMAL THROUGH END
OF PERIOD...POSSIBLY HIGHER NEXT WEEK DEPENDING ON DEGREE OF CLOUD
COVER. HIGHS IN THE 80S REMAIN A POSSIBILITY IF FULL MIXING CAN BE
ACHIEVED NEXT WEEK. WITH SUCH A DEEP SYSTEM TO THE WEST FEEL MODELS
ARE TOO FAST WITH APPROACH OF TROUGH FOR MIDDLE OF NEXT WEEK AND
THUS WED WILL CONTINUE TO BE WARM. RAISED ALLBLEND INIT TEMPS
SEVERAL DEGREES IN LINE WITH DAY 5 AND 6 TEMPS.
&&
.AVIATION.../18Z TAFS/
HIGH CLOUDS SLOWLY STREAMING TOWARDS THE REGION WILL CAUSE LITTLE
IMPACT THROUGH THE AFTERNOON. MAIN FOCUS IS DEEPER MSTR AND LIFT
NOTED ACROSS WESTERN ILLINOIS. HI RES MODELS INDICATE CONVECTIVE
DEVELOPMENT EXPECTED AS ELEVATED INSTABILITY CONTINUES TO
INCREASE. AGITATED CU FIELD NOTED ON NOSE OF THE INCREASING LIFT
AND A FEW SHOWERS HAVE DEVELOPED SE OF ST LOUIS. PREV TAFS HAVE
HANDLE ON CONVECTIVE POTENTIAL THIS EVENING WITH ISOL TO SCT
COVERAGE BEING HANDLED BY VCTS MENTION. HI RES MODELS CONTINUE TO
BRING IN A GOOD DEAL OF FOG LATER TONIGHT AND LINGER INTO MUCH OF
THE DAY THURSDAY AS WEAK BOUNDARY DRIFTING SOUTH INTO THE REGION
LIKELY STALLS OUT. GIVEN POSSIBLE IMPACTS OF CONVECTION THIS
EVENING ON FOG POTENTIAL...HAVE LEFT LATTER PART OF TAFS ALONE.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...FISHER
LONG TERM...LASHLEY
AVIATION...FISHER
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
559 PM CDT WED MAR 14 2012
...UPDATED FOR AVIATION...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 109 PM CDT WED MAR 14 2012
A 500MB ANALYSIS INDICATED A THERMAL TROUGH WAS LOCATED ACROSS
THE SOUTHWESTERN UNITED STATES AT 12Z WEDNESDAY. THIS APPEARS TO
BE ASSOCIATED WITH THE LEFT EXIT REGION OF A 50-60KT 250MB JET
WHICH BOTH THE NAM AND GFS MOVE ACROSS NORTHWEST OKLAHOMA/EXTREME
SOUTHERN KANSAS LATER TONIGHT, MAINLY BETWEEN 06Z AND 12Z
THURSDAY. THEY ALSO INDICATED DECENT MID LEVEL INSTABILITY PRESENT
AHEAD OF THIS WAVE ACROSS PORTIONS OF SOUTH CENTRAL AND NORTH
CENTRAL KANSAS AS WELL AS SOME WEAK 850MB WARM AIR ADVECTION. MID
LEVEL MOISTURE HOWEVER APPEARING SOMEWHAT LACKING BUT AM UNABLE TO
COMPLETELY RULE OUT AN ISOLATED ELEVATED STORM DURING THE PREDAWN
HOURS. AS A RESULT WILL INCLUDE LOW CHANCES FOR THIS OCCURRENCE
EAST OF 283.
AS FOR THUNDERSTORM CHANCES NEAR THE DRYLINE/WARM FRONT ACROSS
SOUTH CENTRAL KANSAS EARLY THIS EVENING...LOW LEVEL FORCING ALONG
THIS BOUNDARY CURRENTLY APPEARS WEAK BUT STILL BOTH THE NAM AND
GFS INDICATING +2000 J/KG CAPES CAN BE EXPECTED AROUND 00Z
THURSDAY ACROSS SOUTH CENTRAL KANSAS. WILL THEREFORE KEEP ISOLATED
THUNDERSTORMS GOING BUT FOCUS THESE SMALL PRECIPITATION CHANCES
FURTHER EAST. GIVEN THIS INSTABILITY ANY STORM THAT DOES DEVELOP
WILL BE CAPABLE OF PRODUCING SOME HAIL BUT GIVEN WEAK 0-6KM SHEAR
AND A FREEZING LEVEL AT OR ABOVE 12000 FEET HAIL SIZE WOULD
AVERAGE LESS THAN A QUARTER.
DRYLINE/WARM FRONT WILL THEN RETREAT WESTWARD ACROSS SOUTHWEST
KANSAS OVERNIGHT. AS THIS DRYLINE APPROACHES THE COLORADO BORDER
AFTER MIDNIGHT...THE MID-UPPER 50 DEW POINTS, WHICH WERE LOCATED
ACROSS WESTERN OKLAHOMA EARLIER TODAY, WILL START TO SPREAD BACK
INTO SOUTHWEST KANSAS. NAM BUFR SOUNDINGS INDICATING THAT THIS LOW
LEVEL MOISTURE WILL RETURN AFTER 06Z WITH THE DEPTH OF THIS
MOISTURE INCREASING TO NEAR 1600 METERS AGL BY 12Z THURSDAY. GFS
HOWEVER WAS NOT AS DEEP WITH THIS MOISTURE RETURN AT 12Z THURSDAY
BASED ON MODEL SOUNDINGS SO TAKING INTO ACCOUNT ALONG WITH LIGHT
WINDS EARLY THURSDAY MORNING WILL EXPAND THE CLOUD COVER A LITTLE
FURTHER NORTHWEST AND RAISE THE LOWS TONIGHT A FEW MORE DEGREES
WHERE THE CLOUD COVER AND HIGHER DEW POINTS ARE NOW EXPECTED.
ON THURSDAY IT WILL TAKE A BIT MORE TIME FOR THE EAST TO HEAT UP
AS THE LOW CLOUDS SLOWLY ERODE. STILL WITH THIS IN MIND THE MODEL
SOUNDINGS ALL INDICATING MIXING HEIGHTS UP TO AT LEAST THE 850MB
LEVEL BY 00Z FRIDAY. BASED ON THIS ALONG WITH THE 00Z FRIDAY 850MB
TEMPERATURE RANGING FROM 16-18C WILL CONTINUE TO FAVOR HIGHS ON
THURSDAY RANGING FROM THE UPPER 70S TO AROUND 80 DEGREES.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 257 PM CDT WED MAR 14 2012
THE FORECAST AREA WILL BE MARKED BY A COUPLE OF DISTINCTLY DIFFERENT
AIRMASSES DURING THE FIRST FEW DAYS OF THE PERIOD. THE MODELS TEND
TO REINFORCE THE LOW LEVEL MOISTURE ACROSS CENTRAL KANSAS WHILE THE
HIGHER TERRAIN TO THE WEST WILL ACT TO CREATE A DIURNALLY ADVANCING
AND RETREATING DRYLINE WHICH MAY OR MAY NOT BECOME A PRIMARY FOCUS
FOR ISOLATED DEEP MOIST CONVECTION THROUGH THE WEEKEND. THE FIRST
OPPORTUNITY FOR CONVECTIVE INITIATION APPEARS TO BE FRIDAY AFTERNOON
THROUGH FRIDAY EVENING. IF THE GFS MODEL FIELDS WERE TO VERIFY,
BETTER LARGE SCALE ASCENT MIGHT BE PRESENT AS THE LEFT FRONT
QUADRANT OF A SOUTHERN STREAM SUBTROPICAL JET WOULD BE PRESENT
PRODUCING A WEAK THERMALLY INDIRECT AGEOSTROPHIC CIRCULATION.
CONSIDERING THIS, AS WELL AS THE NAM SHOWING PRECIPITATION FARTHER
WEST, WE HAVE DECIDED TO TREND POPS A LITTLE CLOSER TO THE SREF
POPS. IN THE CASE OF THE GFS, THE CONVECTION COULD BE SCATTERED OR
EVEN MORE NUMEROUS.
THE LARGE WESTERN TROUGH STILL IS SHOWN BY THE GEM/ECMWF/GFS THROUGH
THE END OF THE WEEKEND WITHOUT LARGE DISCREPANCIES IN THE SYNOPTIC
EVOLUTION. WARM SOUTHWEST BOUNDARY LAYER FLOW WILL DEVELOP ACROSS
THE CENTRAL AND SOUTHERN HIGH PLAINS AHEAD OF THE LARGE SCALE
SOUTHWEST FLOW ALOFT. THE DRYLINE AND WARM MOIST SECTOR AHEAD OF IT
ACROSS CENTRAL KANSAS STILL SEEMS TO REMAIN THE FOCUS FOR ISOLATED
TO SCATTERED CONVECTION THROUGH THE END OF THE WEEKEND. JUST HOW
DEEP A SURFACE LOW MIGHT DEVELOP AND HOW FAR EAST THE DRYLINE
ADVANCES WILL DETERMINE ANY LOW CHANCES FOR THUNDERSTORMS THAT WILL
REMAIN DIURNAL IN NATURE. SATURDAY LOOKS TO BE DRY AS THE MODELS
INDICATE A SUBTLE WAVE LIFTING THROUGH EASTERN KANSAS FROM WESTERN
OKLAHOMA EARLY IN THE DAY. CHANCES INCREASE AS FORCING FOR ASCENT
INCREASED BY SUNDAY. BY MONDAY AND TUESDAY, INCREASING CHANCES FOR A
WIDESPREAD CONVECTIVE EVENT ARE ADVERTISED BY THE MODELS. FOLLOWING
THE OPEN WAVE OF THE ECMWF AND GEM, THE STRONG INSTABILITY AXIS
MIGHT BE SHIFTED TOO FAR WEST TO AFFECT OUR FORECAST AREA. IN STARK
CONTRAST, THE GFS ALLOWS A CUTOFF LOW TO DEVELOP, WHICH IS A MUCH
WETTER SOLUTION. THE 00 UTC ECMWF HAD BACKED OFF ON A SIMILAR
SOLUTION IS WAS DEVELOPING ON YESTERDAYS RUNS BUT HAS SINCE FLIP
FLOPPED WITH ANOTHER CUT OFF LOW. LOW CONFIDENCE EXISTS WITH RESPECT
TO THE EXTENDED AT THIS TIME.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 547 PM CDT WED MAR 14 2012
SHORT RANGE MODELS INDICATING SHALLOW MOISTURE TO CONTINUE TO MOVE
NORTH FROM TEXAS AND OKLAHOMA OVERNIGHT. THE NEW HRRR AND RUC HAVE
IFR CONDITIONS MOVING INTO DODGE CITY AND GARDEN CITY BETWEEN
06-09Z AND AT HAYS BY AROUND 12Z AND LASTING TILL 15Z. AT THIS
TIME SINCE THE EXPECTED FOG IS SO SHALLOW WILL SHOW MVFR
CONDITIONS FOR NOW. NEXT UPDATE MAY HAVE TO INCLUDE VFR CONDITIONS
IF OBSERVATIONS AND HIGH RESOLUTION MODELS WARRANT. COULD ALSO HAVE
AN ISOLATED THUNDERSTORM THIS EVENING MAINLY SOUTH AND SOUTHWEST
OF KDDC AND KGCK. ALSO THERE IS A POSSIBILITY OF A FEW ELEVATED
THUNDERSTORMS OVERNIGHT...BUT NOT ENOUGH CONFIDENCE TO PUT INTO
THE TAF AT THIS TIME.
&&
.FIRE WEATHER...
ISSUED AT 359 AM CDT WED MAR 14 2012
FIRE WEATHER WILL BE A CONCERN IN FAR WESTERN KANSAS BEHIND THE
DRY LINE EACH AFTERNOON FROM FRIDAY TROUGH SUNDAY. DEEP MIXING
SHOULD RESULT IN FREQUENT WIND GUSTS OVER 25 MPH EACH DAY, ALONG WITH
AFTERNOON RELATIVE HUMIDITIES LESS THAN 15%.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 53 80 50 83 / 10 10 0 20
GCK 45 79 46 82 / 0 0 0 10
EHA 41 78 46 82 / 0 0 0 10
LBL 43 81 47 83 / 10 0 0 20
HYS 52 79 50 82 / 10 0 0 10
P28 59 81 55 81 / 20 10 10 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURGERT
LONG TERM....RUSSELL
AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS CARIBOU ME
520 PM EDT WED MAR 14 2012
.SYNOPSIS...
LOW PRESSURE WILL TRACK SLOWLY EAST OF THE REGION TONIGHT. HIGH
PRESSURE WILL BUILD BRIEFLY INTO THE AREA LATER THURSDAY. A WEAK
TROUGH OF LOW PRESSURE WILL APPROACH FROM THE WEST ON FRIDAY AND
CROSS THE STATE LATE FRIDAY AND FRIDAY NIGHT. HIGH PRESSURE WILL
REBUILD INTO THE AREA OVER THE WEEKEND WITH AN UNSEASONABLY WARM
WEATHER PATTERN SHAPING UP FOR NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
UPDATE: SENT A QUICK UPDATE TO INCREASE TOTAL SNFL AMOUNTS TO 4
TO 8 IN ACROSS PORTIONS OF NERN AND FAR NRN AROOSTOOK COUNTY BASED
ON A FEW OBS OF 5 IN ATTM. SOME UNCERTAINTY EXISTS REGARDING HOW
BANDING WILL EVOLVE OVR THE NEXT FEW HRS...WITH NEAR TERM MODELS
SUCH AS THE HRRR SHOWING THE ENHANCED BANDING CURRENTLY JUST W OF
THE ME-NB BORDER POSSIBLY GRAZING FAR NE AROOSTOOK COUNTY. WILL
MONITOR CLOSELY DURG THIS TM.
ORGNL DISC: UPPER LOW TRACKING TOWARDS THE WESTERN BORDER OF
MAINE AS EXPECTED. SOME INSTABILITY ABOVE H850 AND A SHARP UPPER
TROUGH ROTATING AROUND THE CLOSED UPPER LOW IS PRODUCING LOCALLY
HEAVIER SNOW SHOWERS IN FAR NORTHEASTERN ZONES. WILL GO FOR UP TO
5 INCHES IN NE CORNER OF STATE...BUT EXPECT WIDE VARIATIONS FOR
NORTHERN ZONES DUE TO HIT OR MISS NATURE OF THE HEAVIER SNOW
SHOWERS. MOISTURE CONTINUES TO WRAP BACK NORTHWESTWARDS FROM THE
MARITIMES AND WILL HELP PROLONG SNOW IN NORTHERN ZONES WELL INTO
THE NIGHT. DOWN EAST AREAS WILL GET A BRIEF SHOT OF SNOW THIS
EVENING THAT MAY LAY DOWN AN INCH OR SO. THIS WILL BE IN
CONJUNCTION WITH THE UPPER LOW PASSAGE. THE THREAT FOR FZDZ IS
STILL THERE WITH THE RISK FROM NEAR MILO TOWARDS NORTHERN
WASHINGTON COUNTY THIS AFTERNOON AND QUICKLY SHIFTING TO SOUTHERN
WASHINGTON COUNTY THIS EVENING BEFORE THE WARM AIR ALOFT IS GONE.
TEMPERATURES TONIGHT WILL DIP SLIGHTLY IN THE LOWER 20S NORTH AND
UPPER 20S DOWN EAST.
WITH SNOW ENDING IN THE FAR EASTERN ZONES EARLY THURSDAY
MORNING...HIGH PRESSURE WILL BUILD BUT CLOUD COVER ASSOCIATED WITH
A SUBSIDENCE INVERSION WILL BE SLOW TO ERODE FROM THE WEST. EXPECT
SOME CLEARING TOWARDS BANGOR BY AFTERNOON...BUT NOT UNTIL LATE DAY
TOWARDS THE EASTERN BORDER OF THE STATE. HIGHS WILL REACH THE LOW
TO MID 30S TOWARDS THE SJV AND INCREASE TOWARDS DOWN EAST WHERE
LOW 40S ARE LIKELY.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL CREST THE REGION THURSDAY NIGHT AND THEN MOVE
EAST OF THE AREA EARLY FRIDAY. MODELS IN GOOD AGREEMENT WITH UPPER
TROUGH APPROACHING FROM THE WEST FRIDAY AND CROSSING THE STATE BY
FRIDAY EVENING. EXPECT ASSOCIATED LOW PRESSURE AND COLD FRONT TO
SPREAD MAINLY RAIN FROM WEST TO EAST ACROSS THE STATE FRIDAY
AFTERNOON. RAIN MAY MIX WITH SNOW ACROSS EXTREME NORTHERN
SECTIONS. THEN AS UPPER TROUGH MOVES EAST OF THE STATE, CONDITIONS
WILL IMPROVE FROM WEST TO EAST FRIDAY NIGHT. QPF AMOUNTS AT THIS
TIME APPEARS TO BE ON THE LIGHT SIDE WITH AMOUNTS GENERALLY BELOW A
QUARTER OF AN INCH. HIGH PRESSURE THEN BUILD ACROSS NEW ENGLAND ON
SATURDAY WITH CLEAR SKIES AND MODERATING TEMPERATURES INTO THE 40S
AND 50S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
RIDGING BUILDING ALONG THE EAST COAST WILL SET THE STAGE FOR SOME
VERY MILD WEATHER GOING INTO EARLY NEXT WEEK. HIGH PRESSURE ALONG
THE EAST COAST WILL BRING A MOSTLY CLEAR NIGHT SATURDAY NIGHT
FOLLOWED BY A PARTLY SUNNY AND MILD DAY ON SUNDAY. THE LATEST GFS
SHOWS A WEAK COLD FRONT MOVING IN LATE SUNDAY WHICH MAY BRING
INCREASING CLOUDS LATE IN THE DAY. THE ECMWF BRINGS A WEAK FRONT
THROUGH LATER MONDAY. HIGH PRESSURE THEN CONSOLIDATES AGAIN ALONG THE
EAST COAST TUESDAY AS A VERY STRONG RIDGE OF HIGH PRESSURE BUILDS
INTO THE EAST. THIS WILL BRING A PARTLY SUNNY AND VERY MILD DAY ON
TUESDAY. THE STRONGEST INFLUENCE OF THE RIDGING WILL LIKELY COME
WEDNESDAY WHEN WARM WEST TO SOUTHWEST WINDS BOOST TEMPS INTO THE 60S
AND PERHAPS EVEN 70S ACROSS THE REGION. THE VERY WARM TEMPS DURING
THE MID WEEK NEXT WEEK WILL LIKELY RESULT IN LOTS OF SNOW MELT. THE
RELEASE OF SNOW MELT MAY RESULT IN RISES ON RIVERS AND POTENTIAL ICE
JAMS DURING THE MID AND LATE WEEK NEXT WEEK.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
NEAR TERM: IFR TONIGHT FOR ALL TERMINALS...BCMG MVFR THURSDAY
MORNING AND VFR BY LATE AFTERNOON.
SHORT TERM: VFR THURSDAY NIGHT INTO EARLY FRIDAY THEN CONDITIONS
WILL LOWER TO MVFR/IFR IN RAIN FRIDAY AFTERNOON THROUGH FRIDAY
EVENING AND THEN IMPROVE TO VFR LATER FRIDAY NIGHT. EXPECT VFR
CONDITIONS SATURDAY THROUGH WEDNESDAY.
&&
.MARINE...
NEAR TERM: SCA WILL CONTINUE INTO EARLY THURSDAY MORNING...BARELY
MEETING CRITERIA WITH WIND GUSTS AROUND 25 KTS AND 5 FT SEAS.
SHORT TERM: WINDS AND SEAS BELOW SCA CRITERIA THURSDAY NIGHT
THROUGH SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR
MEZ001>006-010-011-015>017-031-032.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THURSDAY FOR ANZ050>052.
&&
$$
NEAR TERM...VJN
SHORT TERM...FOSTER
LONG TERM...BLOOMER
AVIATION...VJN
MARINE...VJN/FOSTER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
133 PM EDT WED MAR 14 2012
.SYNOPSIS...
ISSUED AT 413 AM EDT WED MAR 14 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG OVER MN
BTWN CLOSED LO SHIFTING SEWD THRU QUEBEC AND A MEAN TROF ALONG THE W
COAST. WITH CWA UNDER THE CONFLUENT NW FLOW ALF/12HR H3 RISES AOA
100M...ASSOCIATED SFC HI PRES RDG IS BRINGING TRANQUIL WX/MOCLR
SKIES. AIRMASS IN PLACE IS ALSO RELATIVELY DRY PER LOCAL 00Z
RAOBS...SO SFC TEMPS HAVE FALLEN AOB 32 AT MANY INTERIOR COLD
LOCATIONS WITH THE MOCLR SKIES/LGT WINDS. BUT A MUCH WARMER AIRMASS
IS EVIDENT JUST TO THE W UNDER THE STRONG SLY FLOW BTWN THE SFC HI
PRES RDG OVER THE GRT LKS AND LOWER PRES IN THE HI PLAINS ASSOCIATED
WITH STRONG SHRTWV LIFTING NEWD THRU SW CAN TO THE E OF TROF ALONG
THE W COAST. 00Z H85 TEMPS REACHED AOA 15C ALL THE WAY UP TO GLASGOW
MONTANA AND BISMARCK...AND SFC HI TEMPS WERE UP TO 75 IN EASTERN
MONTANA AND WRN NDAKOTA UNDER THIS WARM SURGE. PIERRE SDAKOTA
REPORTED A MAX TEMP OF 82. THE AIRMASS IN THE CENTRAL AND NRN PLAINS
IS VERY DRY PER 00Z PWAT OF 0.14/0.17 AT RAPID CITY SDAKOTA/NORTH
PLATTE NEBRASKA. BUT A SURGE OF HIER SFC DWPTS IS NOTED MOVING N FM
THE SRN PLAINS...WITH SFC DWPTS AT 03Z UP TO 55 AT KANSAS CITY UNDER
THE STRONG S WINDS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 413 AM EDT WED MAR 14 2012
TODAY...AS SFC HI PRES SHIFTS INTO THE MID ATLANTIC STATES AND SFC
TROF/COLD FNT ASSOCIATED WITH DEEP SHRTWV LIFTING FM SW CAN TOWARD
HUDSON BAY MOVES INTO WRN LK SUP IN THE AFTN...STRONGER SSW FLOW
UNDER SHARPER PRES GRADIENT BTWN THESE FEATURES IS FCST TO LIFT H85
TEMPS UP TO 12-14C THIS AFTN. ALTHOUGH SOME OF THE MORE COPIOUS LLVL
MSTR IS FCST TO PUSH IN THIS AFTN...THE ARRIVAL OF THIS MSTR WL
COINCIDE WITH PEAK HEATING TIME...SO THERE SHOULD NOT BE MUCH IN THE
WAY OF CLD COVER AHEAD OF THE APRCHG TROF/FNT. WITH PLENTY OF
SUNSHINE AND MIXING TO H85 ON NAM FCST SDNGS...EXPECT TEMPS OVER THE
INTERIOR W TO REACH 70 TO 75. AREAS OVER THE E HALF WL BE COOLER
DOWNWIND OF THE MODIFYING INFLUENCE OF LK MI. DAILY RECORD HI TEMPS
OF 62 AT IWD...56 AT CMX...67 AT IMT...AND 60 AT THE MQT NWS OFFICE
ARE IN SERIOUS JEOPARDY. THE ARRIVAL OF THE SFC COLD FNT LATE OVER
THE W WL BRING SOME MORE CLDS/COOLER TEMPS TOWARD EVNG...BUT THE
OVERALL AIRMASS WL BE TOO DRY WITH PERSISTENT INVRN H75-8 TO SUPPORT
ANY PCPN CONSIDERING THE ABSENCE OF H5 FALLS WITH PASSAGE OF THE
MAIN DYNAMICS WELL TO THE N CLOSER TO SHRTWV TRACK. SO IGNORED THE
LGT QPF GENERATED BY THE 00Z GFS.
TNGT...AS MAIN SHRTWV TO THE N MOVES ACRS HUDSON BAY...SFC COOL FNT
WL DRIFT W-E ACRS THE CWA AND INTO NRN LWR MI BY 12Z THU. MODELS...
ESPECIALLY THE GFS...GENERATE SPOTTY QPF OVER MAINLY THE SE ZNS IN
THE EVNG JUST AHEAD OF THE TROF. SINCE THE INCOMING LLVL MSTR DOES
GET DEEPER AND UP TO H85-8 PER NAM FCST SDNGS...OPTED TO MAINTAIN
SCHC POPS FM ROUGHLY MNM TO ERY THRU ABOUT 06Z...WHEN DRYING WITH A
WSHFT TO THE W BEHIND THE FROPA WL ADVECT DRIER AIR EWD. OPTED TO
ADD MENTION OF ELEVATED TS GIVEN STEEP MID LVL LAPSE RATES ABV LLVL
MOISTENING. PERSISTENCE OF INVRN H8-75 IN ABSENCE OF SGNFT MID LVL
DYNAMICS WL BE THE LIMITING FACTOR FOR ANY SHRA/TS. ALTHOUGH THERE
WL BE DRYING ALF AS HI PRES MOVES ACRS NW LK SUP UNDER WSW FLOW
ALF... VARIOUS GUIDANCE SHOWS MORE LLVL MSTR PERSISTING EVEN AFT THE
FROPA. SO TENDED TO MAINTAIN MORE CLD COVER THRU THE NGT WHERE THE
NW VEERING N WIND WL UPSLOPE.
THU...WITH PERSISTENT WSW FLOW ALF BTWN MEAN UPR RDG OVER THE SE
CONUS AND TROFFING OUT W...SFC HI PRES IS PROGGED TO DRIFT INTO
QUEBEC...LEAVING A SFC RDG OVER THE UPR LKS. ALTHOUGH DRY AIR IN THE
MID LVLS WL RESULT IN A PCPN-FREE DAY...VARIOUS MODELS CONTINUE TO
SHOW LINGERING LLVL MSTR WITH SHALLOW COOL AIR INFUSION MAINTAINING
FAIRLY SHARP SFC-BASED INVRN. TRICKY TEMPS FCST FOR THU CONSIDERING
DIFFERENCES IN LLVL MSTR SHOWN BY THE VARIOUS MODELS AND POTENTIAL
FOR MORE PERSISTENT ST/SC. TENDED COOLEST NEAR THE LK SHORES WITH
LGT NE FLOW TENDING TO VEER E AND GREATER HEATING INLAND SUPPORTING
LK BREEZE COOLING. ALTHOUGH TEMPS WL BE CONSIDERABLY COOLER THAN
TDAY AND PROBABLY CLOSER TO THE LOWER NAM GUIDANCE GIVEN RATHER HI
STABILITY SHOWN ON FCST SDNGS/POTENTIAL LO CLDS...READINGS WL STILL
BE WELL ABV NORMAL FOR THE IDES OF MARCH.
THU NGT...MAJORITY OF MODELS SHOW WEAK SHRTWV MOVING IN FM THE
WSW...CAUSING LGT LLVL FLOW TO VEER MORE TO THE S. WHILE THIS WSHFT
MIGHT LIMIT UPSLOPE CLD OFF LK SUP...CONCERN SOME ST/SC COULD DRIFT
IN FM LK MI/BAY OF GREEN BAY. SINCE THE FLOW WL BE LGT AND THE MID
LVLS DRY...ALSO MAINTAINED PATCHY FOG IN THE FCST OVER THE E
DOWNWIND OF LK MI.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 413 AM EDT WED MAR 14 2012
WEAK DISTURBANCE THAT MOVED JUST N OF LK SUPERIOR ON THURS NIGHT
WILL SHIFT E OF THE AREA ON FRI...ALLOWING THE UPPER RIDGE TO
RE-ESTABLISH ITSELF OVER THE UPPER GREAT LAKES ON FRI AND FRI NIGHT.
FRI... MOSTLY SUNNY DUE TO DRY AIR AND SUBSIDENCE UNDER THE UPPER
RIDGE AND EXITING SFC HIGH. MIX TO H900 WOULD YIELD TEMPS IN THE
LOW-MID 60S AWAY FROM LK MI INFLUENCES. MODEL CONSENSUS IS A LIGHT
SE BREEZE...WHICH COULD PRODUCE ONSHORE FLOW OVER THE KEWEENAW
PENINSULA AND LEADS TO THE POTENTIAL FOR LIGHT LK BREEZES OVER THE W
AND NCTNRL. LATEST NAM HAS TRENDED TOWARDS STRONGER WINDS AS IT
TRIES TO MIX INTO THE STRONGER WINDS ALOFT...WHICH WOULD LIMIT LK
BREEZE POTENTIAL.
FRI NIGHT...SRLY FLOW INCREASES AS THE AREA IS BETWEEN SFC HIGH OVER
SW QUEBEC AND LOW NEAR LK WINNIPEG. THIS TRIES TO PULL ADDITIONAL
LLVL MOISTURE OVER THE AREA. GFS IS THE MOST AGGRESSIVE WITH
THIS...WHICH ATTEMPTS TO SOCK THE AREA IN WITH LOW CLOUDS BELOW THE
INVERSION AROUND H850-800. NAM A LITTLE SLOWER...BUT EVENTUALLY
SHOWS A SIMILAR SITUATION. NOT ENTIRELY CONFIDENT THIS WILL
OCCUR...BUT WILL TREND TOWARDS A MORE CLOUDY SOLN. IF THIS LLVL
MOISTURE DOES OCCUR...EXPECT FOG TO DEVELOP OVER LK MI AND MOVE INTO
THE ERN CWA. HAVE ADDED A MENTION OF PATCHY FOG NEAR/OVER LK MI AND
ADDED IT OVER NRN LK SUPERIOR OVERNIGHT.
MODELS STILL OUTPUTTING PCPN...LIKELY LIGHT DRIZZLE...IN ONLY A 1 TO
MAYBE 2KFT AREA OF MOISTURE/CLOUDS NEAR THE SFC. REALLY NOT BUYING
THAT SITUATION...SO WILL CAP POPS JUST BELOW SLIGHT CHANCES.
DAYS 4 THROUGH 7 /SATURDAY THROUGH TUESDAY/...
ANOMALOUS H500 HEIGHTS...AROUND 2-3 STD DEV ABOVE NORMAL FOR
MID-LATE MARCH WILL REMAIN OVER THE AREA FOR THE EXTENDED PERIOD.
OTHER THAN A COUPLE WEAK IMPULSES MOVING THROUGH THE SWRLY FLOW
ALOFT...EXPECT A FAIRLY WARM/DRY PERIOD TO CONTINUE INTO THE FIRST
HALF OF NEXT WEEK.
BEST OPPORTUNITY FOR A WEAK WAVE LOOKS TO BE ON SAT AFTN INTO SUN
MORN. MODELS SHOWING SOME MOISTURE TO WORK WITH ABOVE H850 AND
ELEVATED INSTABILITY WOULD SUPPORT THE POTENTIAL FOR THUNDER IF ANY
SHOWERS DEVELOP WITH THE WEAK SHORTWAVE. OTHERWISE...DON/T SEE ANY
SIGNIFICANT WAVES OR FORCING AFFECTING THE AREA.
MAIN FOCUS FOR THE EXTENDED IS LLVL MOISTURE AND TEMPS. 00Z GFS
CONTINUES TO SHOW ABUNDANT LLVL MOISTURE BELOW THE H850 INVERSION
THROUGH THE EXTENDED PERIOD. 12Z ECMWF...EVEN WITH THE LIMITED LOWER
LEVELS AVAILABLE DOESN/T SHOW THAT EXTENT OF LLVL MOISTURE. GEM DOES
HINT AT IT AND WONDERING IF IT WILL BE DIURNALLY DRIVEN WITH MORE
CLOUDS AT NIGHT AND THEN ATTEMPT TO MIX OUT DURING THE DAY. IT IS
ONE OF THOSE TOUGH SITUATIONS...DUE TO NO SIGNIFICANT CHANGES AND
THE DECENT CAP...WHICH COULD LEAD TO LOW CLOUDS BECOMING TRAPPED
BELOW THE INVERSION AND STRUGGLING TO BREAK OUT. DON/T HAVE ENOUGH
CONFIDENCE ONE WAY OR ANOTHER TO BUCK THE MODEL CONSENSUS AND WILL
LEAVE IT AS IS. MODELS TRYING TO DROP A HUNDREDTH OF QPF OVER THE
GREAT LKS...WHICH IS LARGELY A FUNCTION OF THE LLVL MOISTURE AND
RESULTANT FOG. ADDED PATCHY FOG NEAR LK MI FOR SAT/SUN AND ALSO LK
SUPERIOR JUST OFF SHORE FROM UPPER MI WITH THE SSE FLOW. MAY NEED TO
EXTEND IT THROUGH THE EXTENDED PERIOD IF LLVL MOISTURE PANS
OUT...WHICH WOULD PROBABLY PRODUCE SOME DENSE PERIODS.
TEMPS REMAIN WELL ABOVE NORMAL THROUGH THE FIRST PART OF NEXT
WEEK...WITH HIGHS IN THE 60S AWAY FROM THE SOUTHERLY WINDS OF LK
MI. LOW CLOUDS/FOG COULD CAUSE ISSUES WITH THESE TEMPS AND ONLY
CHANGES MADE TO THE MODEL CONSENSUS WAS TO WARM UP DOWNSLOPE AREAS
NEAR LK SUPERIOR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 132 PM EDT WED MAR 14 2012
VFR CONDITIONS WILL CONTINUE TO DOMINATE AT KIWD/KCMX/KSAW THIS AFTN
UNDER VERY DRY AIRMASS. A COLD FRONT ARRIVING LATE THIS AFTN OVER
WRN UPPER MI WILL BRING A WSHFT BY 00Z AT KIWD/KCMX AND LATER IN THE
EVENING AT KSAW. THERE ARE QUESTIONS AS TO HOW MUCH LOW-LEVEL
MOISTURE WILL TRAIL THE FRONT AND WHETHER LOW CLOUDS WILL DEVELOP IN
THE SHALLOW COOL AIRMASS ENHANCED BY THE CHILLY MARINE LAYER FROM
LAKE SUPERIOR. AT THIS POINT...IT APPEARS KSAW SHOULD HAVE THE
GREATEST POTENTIAL FOR AN IFR CIG AND POTENTIALLY FOG TO DEVELOP
BEHIND THE FRONT LATER TONIGHT AS WINDS VEER TO A MORE UPSLOPE
NORTHERLY DIRECTION. IF DWPTS RISE MORE SUBSTANTIALLY ALONG
APPROACHING FRONT OVER THE NEXT SEVERAL HRS...LOW CLOUDS MAY BE MUCH
MORE WIDESPREAD TONIGHT. UPSTREAM...SFC DWPTS FALL OFF QUITE A BIT
BEHIND COLD FRONT...SO WHERE LOW CLOUDS DO DEVELOP TONIGHT...THEY
SHOULD CLEAR OUT MID TO LATE MORNING THU.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 413 AM EDT WED MAR 14 2012
EXPECT WINDS TO BE GENERALLY UNDER 25 KTS INTO THIS WEEKEND AS A
RELATIVELY WEAK PRES GRADIENT DOMINATES. ALTHOUGH A SHARPER PRES
GRADIENT/STRONGER S FLOW WILL DEVELOP OVER THE WEEKEND...THE
UNSEASONABLY WARM AIR OVER THE UPPER GREAT LAKES WILL ALSO RESULT IN
PERSISTENT MARINE LAYER/STRONG STABILITY OVER THE LAKE...HELPING TO
KEEP SURFACE WINDS ON THE LIGHTER SIDE. AT SOME POINT...FOG MAY
BECOME AN ISSUE...BUT EXPECTED DRY WEATHER THRU THE WEEKEND WILL
LIMIT THIS POTENTIAL.
&&
.HYDROLOGY...
ISSUED AT 413 AM EDT WED MAR 14 2012
WARM TEMPERATURES OVER THE LAST SEVERAL DAYS...ALONG WITH RAIN OF
0.10 TO MORE THAN 0.5 INCH ON MON HAS LED TO INCREASED SNOWMELT/
RUNOFF. THIS RUNOFF HAS PRODUCED SOME RISE IN LEVELS OF RIVERS IN
UPR MI OVER THE LAST COUPLE OF DAYS. TEMPS HAVE FALLEN BLO 32 AT
MANY SPOTS OVER THE CWA EARLY THIS MRNG...BRINGING A TEMPORARY
RESPITE TO THE STEADY MELTING.
ABOVE NORMAL TEMPERATURES INTO NEXT WEEK WILL CONTINUE TO MELT THE
SNOW PACK AND LEAD TO FURTHER INCREASES IN RIVER AND STREAM LEVELS.
DESPITE THE BREAK EARLY THIS MRNG...A PERIOD OF RAPID MELTING WILL
OCCUR TODAY...AS TEMPERATURES RISE AOA 70 DEGREES OVER THE WEST AND
DEWPOINTS RISE INTO THE 40S LATER IN THE DAY. ALTHOUGH A COOLER
AIRMASS WILL ARRIVE ON THU...EXPECT SOME OF THE RIVERS ACROSS THE
AREA TO EXCEED THEIR BANKS BY THE END OF THIS WEEK. PERSONS LIVING
NEAR RIVERS AND STREAMS SHOULD MONITOR THE LATEST RIVER CONDITIONS
AND USE CAUTION IF WALKING ALONG RIVER BANKS...ESPECIALLY THE
CHOCOLAY RIVER...TRAP ROCK RIVER...AND THE STURGEON RIVER IN WESTERN
UPPER MICHIGAN.
THERE WAS AN APPARENT ICE JAM ON THE ONTONAGON RIVER NEAR ROCKLAND
MON EVENING. THIS CAUSED THE RIVER LEVELS TO RISE 4FT BEFORE IT
BROKE FREE. WILL NEED TO MONITOR CONDITIONS ALONG THE ONTONAGON RIVER
OVER THE NEXT DAY OR TWO...AS THE NUMEROUS BENDS COULD CAUSE THE ICE
TO FORM ANOTHER JAM. IN ADDITION...ICE WAS REPORTED ON THE FORD RIVER
AT HYDE AND THE MOUTH AT LK MI. DEPENDING ON THE BREAKUP OF THE
ICE...THERE IS A POTENTIAL FOR ICE JAMS THIS WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...KC
HYDROLOGY...KC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1243 PM CDT WED MAR 14 2012
.AVIATION...
18Z TAFS FOR KOFK...KLNK AND KOMA.
A WIND SHIFT IS PUSHING THE LOW CLOUDS AND HIGHEST SURFACE
DEWPOINTS OFF TO THE EAST...SO EXPECT VFR CONDITIONS THROUGH THE
REST OF THE AFTERNOON WITH NORTHWEST WINDS AT 5 TO 15KTS BECOMING
LIGHT NORTHEAST AFTER 00Z AND THEN VARIABLE OVERNIGHT. THE LOW
LEVEL DEWPOINTS WILL RETURN THURSDAY MORNING AND WITH THE WEAK
FLOW...INCLUDED SOME MVFR VSBYS AFTER 12Z THURSDAY WITH FOG. AT
THIS TIME HAVE HELD OFF ON LOW CLOUD DEVELOPMENT...BUT MAY SEE LOW
CLOUD RE-DEVELOPMENT APPROACHING KLNK AND KOMA THURSDAY AM.
&&
PREV DISCUSSION... /ISSUED 359 AM CDT WED MAR 14 2012/
DISCUSSION...
FOCUS CENTERS AROUND RECORD/NEAR RECORD TEMPS AND CHANCES FOR
TSTMS NEXT FEW DAYS.
WEAK UPPER LEVEL RIDGE HAS MOVED WELL EAST OF THE REGION LEAVING
CENTRAL PLAINS IN WEAK SOUTHWESTERLY FLOW ALOFT FOR NEXT FEW DAYS.
SEVERAL WEAK SHORTWAVES ARE EMBEDDED WITHIN THIS SOUTHWEST FLOW
AND WILL COMPLICATE THE FORECAST INTO THE WEEKEND. MODEL AGREEMENT
ON STRENGTH OF THESE SHORTWAVES IS POOR...LEADING TO LOW
FORECASTER CONFIDENCE ON TSTM CHANCES INTO THE WEEKEND.
TEMPERATURES REMAIN QUITE WARM THIS MORNING AND WILL BE CLOSE TO
RECORD MAX MINS. STRONG MOIST ADVECTION CONTINUES WITH UPSTREAM
DEWPOINTS IN THE UPPER 50S. PATCHY STRATUS IS BEGINNING TO DEVELOP
ACROSS SRN KS AND SO WILL HAVE TO KEEP A CLOSE EYE ON HOW
WIDESPREAD THIS BECOMES THROUGH THE MORNING HOURS. 06Z NAM AND
LATEST HRRR ARE TOO QUICK ON SPREADING THIS STRATUS INTO OUR SERN
COUNTIES SO DO HAVE RESERVATIONS ABOUT ADDING CLOUDS TO THE
SOUTHEAST. SURFACE COLD FRONT CURRENTLY EXTENDS ACROSS CNTRL ND
AND INTO NWRN SD AND WILL QUICKLY PUSH SEWD THROUGH THE MORNING
HOURS AND ENTER INTO THE NWRN CWA BY LATE MORNING. WE SHOULD BE
ABLE TO MIX OUT AHEAD OF THE BOUNDARY WITH THE FRONT COMING THRU A
MAJORITY OF THE CWA BY PEAK HEATING. HAVE FOLLOWED MORE CLOSELY TO
PREVIOUS FORECAST HIGHS TODAY RATHER THAN JUMP ONTO NEW MET
GUIDANCE WHICH IS ABOUT 10 DEGREES COOLER. WE ARE STILL
FORECASTING NEAR RECORD HIGHS AT LNK AND OMA. DID REMOVE CHANCE OF
TSTMS TONIGHT AS FORCING IS MINIMAL AND INSTABILITY AXIS IS FAR TO
OUR SOUTH. SFC FRONT WASHES OUT OVER THE FORECAST AREA THIS
EVENING.
SOUTHERLY LOW LEVEL FLOW RETURNS ON THURSDAY WITH SFC DEWPOINTS
RETURNING INTO THE UPPER 50S TO NEAR 60 IN OUR SOUTH BY THURSDAY
AFTERNOON. DRY LINE/SFC TROF IS FORECAST TO REMAIN JUST TO OUR WEST
AND AS A WEAK UPPER LEVEL SHORTWAVE APPROACHES THE REGION...TSTMS
COULD POSSIBLY DEVELOP BY LATE AFTERNOON. SWODY2 HAS LARGE AREA OF
SLIGHT RISK OVER THE CWA. WL CONCENTRATE TSTM CHANCES MAINLY IN THE
SOUTH WHERE RICH THETA-E AIR RESIDES. VEERED LOW LEVEL JET AROUND
30KTS WL AID IN LLVL CONVERGENCE INTO THE EVENING HOURS. CONFIDENCE
IS LOW ON THE TSTM CHANCES SO THEREFORE HAVE ONLY GONE WITH A SLIGHT
CHANCE POP.
SOUTHWESTERLY FLOW ALOFT CONTINUES INTO THE WEEKEND WITH RICH
BOUNDARY LAYER MOISTURE REMAINING IN PLACE. SHORTWAVE IS
FORECAST TO PASS OVER THE REGION WITH LITTLE CONFIDENCE ONCE
AGAIN ON STRENGTH. WL NOT GET TOO CARRIED AWAY ADDING TSTMS OVER
THE ENTIRE FORECAST AREA JUST YET BUT DO HAVE LOW POPS IN THE SOUTH
ON FRIDAY NIGHT AS NOSE OF VEERED 50KT LOW LEVEL JET CREEPS INTO
SERN NEB WHERE INSTABILITY REMAINS MODERATE.
IN THE EXTENDED...LARGE WESTERN TROF AXIS IS FORECAST TO SLOWLY
PROGRESS INTO THE FOUR CORNERS REGION BY MONDAY AND BECOME SLIGHTLY
NEGATIVELY TILTED BY TUESDAY AS IT MOVES TOWARD THE CNTRL PLAINS.
CHANCE POPS CONTINUE FOR MUCH OF NEXT WEEK AHEAD OF THIS LARGE
TROUGH.
KERN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1202 PM CDT WED MAR 14 2012
.AVIATION...18Z TAF. SURFACE HIGH PRESSURE WILL BUILD SOUTH FM THE
DAKOTAS THIS AFTN AND SHIFT EAST WITH TIME. WINDS WILL BE FROM A
NORTHERLY DIRECTION INITIALLY BUT WILL BECOME LIGHT AND VARIABLE
THIS EVENING AND WILL REMAIN VARIABLE INTO THURSDAY MORNING. SKIES
WILL BE CLEAR OR BE LIMITED TO HIGH CLOUDS AT BEST.
&&
PREV DISCUSSION... /ISSUED 525 AM CDT WED MAR 14 2012/
SHORT TERM...THROUGH FRIDAY NIGHT. PRIMARY FORECAST CHALLENGE IS
DETERMINING WHEN...AND EVEN TO SOME EXTENT IF...LEGITIMATE
SHOWER/THUNDERSTORM DEVELOPMENT WILL TAKE PLACE WITHIN THE CWA AS
THE AIRMASS DESTABILIZES OVER THE NEXT FEW DAYS.
09Z OBJECTIVE SURFACE ANALYSIS REVEALS A WEAK TROUGH AXIS CUTTING
ACROSS THE HEART OF THE CWA FROM NORTHEAST TO SOUTHWEST...TRAILING
WELL SOUTH OF A STRONG...PARENT SURFACE LOW IN CANADA. TO THE
SOUTHEAST OF THIS TROUGH AXIS...AN INCREDIBLY BALMY NIGHT HAS BEEN
OBSERVED WITH TEMPS EVEN AT THIS HOUR RIGHT AROUND 60 IN THE
SOUTHEAST CWA...ACCOMPANIED BY SOUTHERLY BREEZES GUSTING TO AROUND
20 MPH OR HIGHER. FOR THE MAJORITY OF THE CWA HOWEVER...BREEZES
ARE LIGHTER WITH A LIGHT NORTHWEST COMPONENT STARTING TO WORK INTO
NORTHWEST ZONES...WHERE TEMPS ARE NOTABLY COOLER IN THE 40S AND
EVEN SOME UPPER 30S. ALOFT...11-3.9 MICRON AND WATER VAPOR
SATELLITE IMAGERY REVEAL EXPANSIVE WEST-SOUTHWEST FLOW ACROSS THE
CENTRAL PLAINS...WELL TO THE SOUTH OF A POWERFUL NEGATIVELY TILTED
SHORTWAVE GRINDING ACROSS SOUTH CENTRAL CANADA. WHILE SKIES ARE
GENERALLY CLEAR OVER THE CWA...A PLUME OF THIN CIRRUS IS SKIRTING
ACROSS NORTHERN COUNTIES...WHILE A FEW COUNTIES SOUTHEAST OF THE
CWA...SOME LOW STRATUS IS STARTING TO EXPAND ACROSS SOUTH CENTRAL
AND EASTERN KANSAS.
STARTING OFF RIGHT AWAY THIS MORNING...WILL RUN WITH THE
ASSUMPTION THAT ANY LOW STRATUS DEVELOPING TO OUR SOUTHEAST WILL
REMAIN JUST SOUTHEAST OF THE CWA...ALTHOUGH IT COULD BE A FAIRLY
CLOSE CALL PER 925MB RH PROGS FROM THE 06Z NAM. HRRR HAS ALSO BEEN
SUGGESTING SOME PRE-DAWN FOG DEVELOPMENT IN SOUTHEAST ZONES...BUT
UNLESS WINDS REALLY DROP OFF NOT ANTICIPATING ANYTHING MORE THAN
MAYBE A LIGHT HAZE NOT WORTH MENTIONING IN THE FORECAST AT THIS
POINT. GETTING ON WITH THE BULK OF THE DAY...ANOTHER IN A
REMARKABLE STRING OF DAYS WITH TEMPS RUNNING AROUND 30 DEGREES
ABOVE NORMAL IS IN STORE...AS THE LOW LEVEL TEMP PROFILE IS
ESSENTIALLY UNCHANGED FROM YESTERDAY. ONLY MAIN DIFFERENCE FROM
YESTERDAY IS THAT WINDS WILL BE LIGHTER AND TRANSITION TO MORE OF
A NORTHWEST/NORTHERLY COMPONENT AS THE AFOREMENTIONED TROUGH
AXIS/WEAK COLD FRONT SLIDES THROUGH. 06Z RUC SUGGESTS NORTHERLY
BREEZES COULD GET SLIGHTLY BREEZY FOR A FEW HOURS MAINLY LATER
THIS MORNING...BUT SPEEDS ARE ANTICIPATED TO REMAIN SHORT OF RED
FLAG WARNING CRITERIA. FOR MORE FIRE WEATHER DISCUSSION...PLEASE
SEE SEPARATE SECTION BELOW. GETTING BACK TO HIGH TEMPS...CHANGED
LITTLE FROM PREVIOUS WITH WIDESPREAD UPPER 70S/NEAR 80 IN NEB
ZONES...AND LOW-MID 80S IN KS.
THIS EVENING/TONIGHT...THE LARGE SCALE PATTERN ALOFT REMAINS
LARGELY UNCHANGED WITH THE BROAD WEST-SOUTHWEST FLOW...BUT AT
LEAST KS PORTIONS OF THE CWA SHOULD FINALLY START REALIZING SOME
LEGITIMATE ELEVATED INSTABILITY MAINLY AFTER MIDNIGHT WITH THE
06Z NAM/GFS PROGGING MUCAPE IN THE 850-700MB LAYER INCREASING TO
BETWEEN 500-1000 J/KG AFTER MIDNIGHT. THIS IS IN RESPONSE TO
MODEST THETA-E ADVECTION SPARKED BY A SUBTLE SHORTWAVE
TRANSITIONING THROUGH THE FLOW. COMPARED TO 24 HOURS AGO...MODELS
IN GENERAL ARE MUCH LESS BULLISH ON INITIATING CONVECTION...WITH
THE NAM NOW DRY AND GFS FOCUSING OVERNIGHT CONVECTION SOUTH OF THE
CWA. 00Z 4KM WRF-NMM IS ALSO DRY. ALL THAT BEING SAID...TRIMMED
SLIGHT CHANCE FOR STORMS OUT OF NEB ZONES BUT KEPT A TOKEN MENTION
GOING ACROSS KS...AS WOULD NOT BE SURPRISED TO SEE A ROGUE STORM
POP IN THE FAVORABLE THETA-E ADVECTION REGIME. STILL...WOULD NOT
BE SURPRISED IF DAY SHIFT OPTS TO PULL THE SLIGHT POP ALTOGETHER
DEPENDING ON WHAT NEW MODEL SUITE HAS TO OFFER. FOR LOW TEMPS
TONIGHT...KEPT SIMILAR TO PREVIOUS OVERALL...BUT NUDGED DOWN
SOUTHEAST SLIGHTLY AS LIGHT/VARIABLE WIND REGIME SHOULD ALLOW FOR
MORE OF A DROP. THUS HAVE A RANGE FROM UPPER 30S FAR NORTHWEST TO
LOW 50S FAR SOUTHEAST.
THURSDAY...SAME OLD STORY ALOFT WITH THE WEST-SOUTHWEST FLOW...BUT
DOWN LOW...INSTABILITY REALLY RAMPS UP DURING THE AFTERNOON TO THE
EAST OF ANOTHER FAIRLY SUBTLE SURFACE TROUGH AXIS DROPPING IN FROM
THE NORTHWEST. ALTHOUGH THE NAM CAPE VALUES MAY BE OVERDONE...EVEN
THE 06 GFS BRINGS 0-1KM MLCAPE INTO THE 1000-1500 J/KG RANGE
DURING PEAK HEATING IN EASTERN ZONES...WITH FAIRLY WEAK CAPPING
AND AROUND 30KT OF DEEP LAYER SHEAR. THE ULTIMATE QUESTION IS
WHETHER SUBTLE FORCING WILL BE STRONG ENOUGH TO FIRE CONVECTION.
MODELS CONTINUE TO THROW VARIOUS QPF SOLUTIONS...WITH THE 06Z NAM
LESS AGGRESSIVE THAN ITS 00Z RUN FOR THURSDAY AFTERNOON...BUT
STILL SHOWING CONVECTIVE POTENTIAL IN THE EVENING MAINLY EAST OF
HWY 281. THE 00Z ECMWF KEEPS ALL CONVECTION SEVERAL COUNTIES EAST
OF THE CWA DURING THIS TIME. ALL THINGS CONSIDERED...CONFIDENCE IS
QUITE LOW WHETHER CONVECTION WILL FIRE...BUT AGREE WITH SPC DAY 2
OUTLOOK THAT ANYTHING THAT DOES GO COULD BECOME STRONG/SEVERE AND
YIELD HAIL/STRONG WINDS. THUS INTRODUCED LOW CONFIDENCE SLIGHT
CHANCE POPS MAINLY ACROSS EASTERN ZONES THURS AFTERNOON INTO
EVENING...WITH NOTHING AFTER 06Z AS ANY POTENTIAL STORMS EXPECTED
TO BE OFF TO THE EAST BY THEN. GETTING BACK TO THE DAYTIME
HOURS...ESSENTIALLY COOKIE CUTTER HIGH TEMPS CONTINUE...WITH
WIDESPREAD UPPER 70S TO NEAR 80.
FRIDAY INTO FRIDAY NIGHT...UPPER PATTERN STARTS TO SHIFT MORE
SOUTHWESTERLY AS LARGE SCALE TROUGH BEGINS TO IMPINGE ON WEST
COAST. SOUTHERLY BREEZES WILL START PICKING UP DURING THE
DAY...AND BOOSTED SPEEDS NOTICEABLY IN GRIDS...WITH SUSTAINED
SPEEDS AT LEAST AROUND 20 MPH ANTICIPATED. ALTHOUGH AIR MASS WILL
CONTINUE TO MOISTEN WITH WIDESPREAD 50+ DEWPOINTS PROGGED IN
EASTERN COUNTIES...AGAIN HAVE HIGH TEMPS RIGHT AROUND 80 MOST
AREAS. STRONGLY CONSIDERED ADDING ANOTHER SLIGHT CHANCE OF
THUNDERSTORMS DURING THIS TIME FRAME AS VARIOUS MODELS DEPICT AN
EMBEDDED MID LEVEL WAVE SPARKING CONVECTION IN OR NEAR THE
CWA...ESPECIALLY THE GFS ON FRIDAY NIGHT WITHIN A STRONG LOW LEVEL
JET AXIS AND MUCAPE IN EXCESS OF 1000 J/KG. CERTAINLY IF ANY
STORMS DO MANAGE TO FIRE FRIDAY AFTERNOON INTO THE NIGHT...STRONG
TO SEVERE POTENTIAL IS THERE PER SPC DAY 3 OUTLOOK...BUT WITH THIS
STILL BEING 5-6 PERIODS OUT AND MODELS STRUGGLING WITH RUN TO RUN
CONSISTENCY OF FORCING/TIMING OF QUICK MOVING WAVES...WILL OPT TO
OMIT THUNDERSTORM MENTION FOR NOW. WOULD RATHER PLAY IT
CONSERVATIVE AND NOT LITTER THE FORECAST WITH MULTIPLE SLIGHT
CHANCES OF STORMS UNTIL CONFIDENCE BECOMES CLEARER AT THIS RANGE.
AS MENTIONED LAST NIGHT...WILL NEED TO ALSO MONITOR NEXT FEW
NIGHTS FOR POSSIBLE FOG DEVELOPMENT MAINLY IN SOUTHEAST ZONES
WHERE BETTER LOW LEVEL MOISTURE WILL RESIDE...BUT CONFIDENCE IS
STILL TOO LOW TO INSERT A FORMAL FOG MENTION INTO FORECAST.
LONG TERM...SATURDAY THROUGH TUESDAY. MAIN FORECAST CONCERNS WILL
BE CHANCES FOR THUNDERSTORMS MONDAY THROUGH TUESDAY AND TEMPERATURES
THROUGH THE PERIOD.
SOUTHWESTERLY FLOW ALOFT WILL CONTINUE SATURDAY THROUGH SUNDAY
NIGHT. A FEW WAVES MOVE THROUGH THE FLOW BUT THE FORECAST SHOULD
REMAIN DRY. THE SURFACE GRADIENT TIGHTENS THROUGH THE PERIOD AND
EXPECT THAT WINDS WILL BE FAIRLY STRONG OVER THE WEEKEND.
TEMPERATURES DURING THIS PERIOD REMAIN VERY WARM WITH READINGS 25 TO
30 DEGREES ABOVE NORMAL.
THE UPPER LOW IN THE SOUTHWEST CONUS STARTS TO MOVE TO THE EAST
SUNDAY NIGHT AND AFFECTS THE AREA MONDAY THROUGH TUESDAY. MODELS
HAVE QUITE A FEW INCONSISTENCIES BOTH BETWEEN MODELS AND EVEN RUN TO
RUN WITHIN THE MODEL. DESPITE THESE DIFFERENCES THERE ARE SOME
SIMILARITIES AS WELL. THERE IS A LONG TERM FETCH OF WARM MOIST AIR
FROM THE GULF INTO THE EASTERN PART OF THE REGION. AS THE LOW GETS
CLOSER THE MOISTURE GETS PULLED INTO THE CIRCULATION AND THERE IS A
CHANCE FOR THUNDERSTORMS. THE MODEL DEPICTION OF PRECIPITATION IS
FAIRLY SIMILAR CONSIDERING ALL THE DIFFERENCES. WILL KEEP CHANCES
FOR THUNDERSTORMS ACROSS THE AREA MONDAY THROUGH TUESDAY.
TEMPERATURES AT 850MB ARE SEVERAL DEGREES COOLER THAN DURING THE
WEEKEND SO EXPECT THAT TEMPERATURES WILL BE A BIT COOLER...BUT STILL
SHOULD BE ABOVE NORMAL.
FIRE WEATHER...ALTHOUGH WINDS TODAY SHOULD FALL WELL SHORT OF
OFFICIAL RED FLAG WARNING CRITERIA OF SUSTAINED 20 MPH/GUST 25
MPH...RELATIVE HUMIDITY VALUES ARE YET AGAIN PROGGED TO SLIP AT
LEAST DOWN INTO THE 15-20 PERCENT RANGE FOR MANY AREAS THIS
AFTERNOON...ESPECIALLY WEST OF THE HIGHWAY 281 CORRIDOR. AS A
RESULT...THE GRASSLAND FIRE DANGER PRODUCT...RFDGID...HAS DECLARED
EXTREME FIRE DANGER ACROSS THESE CENTRAL AND WESTERN AREAS THIS
AFTERNOON...WITH CATEGORICAL VERY HIGH FIRE DANGER IN COUNTIES TO
THE EAST. WITH INCREASING LOW LEVEL MOISTURE OVER THE NEXT SEVERAL
DAYS...TODAY SHOULD BE THE LAST DAY FOR AWHILE THAT WILL FEATURE
WIDESPREAD RH VALUES BELOW 20 PERCENT. GIVEN THE INCREDIBLE WARM
PATTERN WE ARE IN...THE AREA CAN CERTAINLY USE SOME WIDESPREAD
RAINFALL TO QUELL THE FIRE THREAT...ALTHOUGH FOR MUCH OF THE CWA
THAT MAY HAVE TO WAIT UNTIL AT LEAST EARLY NEXT WEEK WHEN THE
LARGE SCALE TROUGH MOVES IN.
CLIMATE...GONNA BE ANOTHER DAY OF AT LEAST NEARING RECORD HIGHS
IN THE TRI-CITIES. ALTHOUGH OFFICIAL FORECAST CURRENTLY KEEPS
READINGS JUST SHORT...THE HIGHS TO BREAK ARE ALL FROM WAY BACK IN
1935...AND CONSIST OF 81 IN GRAND ISLAND...83 IN HASTINGS AND 82
IN KEARNEY. THIS DOES NOT LOOK TO BE THE LAST DAY OF THE NEXT
SEVERAL IN WHICH RECORD HIGHS COULD BE IN JEOPARDY OF
FALLING...BUT THOSE FOR THURSDAY DO APPEAR LEGITIMATELY OUT OF
REACH AS THINGS STAND.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
259 PM EDT WED MAR 14 2012
.SYNOPSIS...
A WEAK SURFACE TROUGH WILL MOVE DROP SOUTH INTO THE AREA
TODAY AND DISSIPATE. SURFACE HIGH PRESSURE OFFSHORE WILL CONTINUE
TO INFLUENCE THE WEATHER THROUGH THE REMAINDER OF THE WEEK. A
BACKDOOR COLD FRONT WILL SLIP SOUTH INTO THE AREA THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 145 PM WED...MINOR UPDATE FOR HOURLY TEMPS. DID RAISE MAX
TEMPS UP A FEW DEGS MOST AREAS.
/PREVIOUS DISCUSSION/
AS OF 1130 AM WED...NO MAJOR CHANGES WITH UPDATE. STRATUS/FOG HAVE
DISSIPATED OVER COASTAL PLAINS AND EXPECTING MOSTLY SUNNY SKIES
UNTIL CU DEVELOPMENT OVER INLAND SECTIONS MID AFTN. LATEST RUC AND
HRRR MODELS INDICATE SOME ISOLD CONVECTIVE ACTIVITY IN SEA BREEZE
ZONE...THUS WILL KEEP CURRENT SLGT CHC POPS FOR THAT AREA. TEMPS
CONTINUE TO LAG OVER SRN COASTAL PLAINS WHERE STRATUS LIMITED
MORNING INSOLATION...BUT LATEST LAMP GDNC SUPPORTS TEMPS NEAR 80
THERE BY LATE AFTN.
WEAK WIND SHIFT WITH SFC TROF WILL HAVE LITTLE CONSEQUENCE BUT MAY
PROVIDE ADDITIONAL CONVERGENCE WITH SEA BREEZE ZONE FOR CONVECTIVE
INITIATION.
&&
.SHORT TERM /THURSDAY/...
AS OF 325 AM WEDNESDAY...CLEAR SKIES AND LIGHT WINDS ARE EXPECTED
ACROSS EASTERN NC TONIGHT AS WEAK HIGH PRESSURE RIDGES WEST INTO
THE AREA FROM THE ATLANTIC. DUE TO EXPECTED STRONG RADIATIONAL
COOLING...I TRENDED OVERNIGHT LOWS TO THE COOLER MOS GUIDANCE WITH
READINGS MAINLY IN THE LOWER 50S. WOULD EXPECT POTENTIAL FOR FOG
TO DEVELOP LATE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AS OF 245 PM WED...HIGH PRESSURE WILL CONTINUE OFF THE SOUTHEASTERN
COAST THURS NIGHT AHEAD OF A DEVELOPING SHORTWAVE/SURFACE LOW
PROGGED TO CROSS NORTH OF THE REGION ON SAT. SURFACE WINDS WILL
REMAIN SOUTHERLY AHEAD OF THE SYSTEM LATE FRI INTO SAT...ALLOWING
FOR WARM/MOIST AIR TO ADVECT INTO EASTERN NC. FORECAST SOUNDINGS
CONTINUE TO INDICATE SUFFICIENT INSTABILITY...WHICH COUPLED WITH
MOISTEN BOUNDARY LAYER WILL PRODUCE ISOLATED SHOWERS AND
THUNDERSTORMS FRI AFTERNOON/EVENING. SPC CONTINUES TO LIST THE
REGION IN GENERAL THUNDER RISK FRI. GREATER CLOUD COVER FRI WILL
BRING TEMPS A COUPLE DEGREES COOLER THAN THURS...HOWEVER STILL
APPROACH 80 F INLAND.
SHORTWAVE ENERGY APPROACHES FROM THE NORTHWEST FRI NIGHT AND PUSHES
OFF THE EAST COAST NEAR THE DELMARVA PENINSULA SAT MORNING. WEAK
SURFACE LOW WILL DEVELOP OFF THE COAST SAT WITH A WEAK BACK DOOR
COLD FRONT PROGGED TO SLIDE SOUTH ACROSS EASTERN NC SAT AFTERNOON
INTO THE EVENING. SOUTHERLY WINDS AHEAD OF THE FRONT WILL REMAIN
SOUTHWESTERLY THEN VEER NORTH AND NORTHEAST BEHIND THE FRONT.
INCREASED CLOUD COVER WILL BRING COOLER TEMPS SAT...MID 70S INLAND
TO LOW 70S ALONG THE COAST. KEPT POPS SAT NIGHT CONFINED TO COASTAL
ZONES ASSOCIATED WITH BEST CONVERGENCE ALONG SURFACE FRONT. TOTAL
QPF FOR THE SYSTEM WILL REMAIN 0.10-0.20 INCHES WITH LOCALLY HIGHER
AMOUNTS POSSIBLE IN THUNDERSTORMS.
HIGH PRESSURE ACROSS SOUTHERN NEW ENGLAND AND NORTHWESTERN ATLANTIC
WILL MIGRATE SOUTH TOWARDS THE REGION SUN THROUGH EARLY NEXT WEEK.
NORTHEASTERLY WINDS WILL ADVECT SLIGHTLY LOWER THICKNESSES INTO THE
REGION...YIELDING TEMPS IN THE LOW 70S SUN TO MID/UPPER 70S MON AND
TUES. OVERNIGHT LOWS SUN AND MON WILL REMAIN MILD...LOWER 50S.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
SHORT TERM /18Z TODAY THROUGH 18Z THURSDAY/...
AS OF 130 PM WED...HIGH CONFIDENCE IN VFR PREVAILING THROUGH THIS
EVENING. ISOLD TSTM CANNOT BE RULED OUT WITH SEA BREEZE THIS AFTN
BUT NOT ENOUGH THREAT TO INCLUDE IN TAFS. EXCELLENT RADIATIONAL
COOLING IS EXPECTED TONIGHT WHICH SHOULD LEAD TO THE DEVELOPMENT OF
PATCHY FOG AND SUB VFR VISIBILITIES. UPS FOG TOOL INDICATES
POTENTIAL FOR DENSE FOG (<1 SM) ALL BUT KPGV WITH CROSSOVER TEMPS
BEING REACHED...BUT NOT ENOUGH FCST CONFIDENCE TO INDICATE IFR VSBYS
WITH THIS FCST ISSUANCE.
LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 250 PM WED...VFR CONDITIONS EXPECTED FRI AS HIGH PRESSURE
REMAINS OFF THE COAST. SOUTHWESTERLY FLOW WILL GUST NEAR 20 KNOTS
FRI AHEAD OF A BACK DOOR COLD FRONT THAT WILL SAG SOUTH ACROSS THE
REGION SAT INTO EARLY SUN. FORECAST SOUNDINGS FRI INDICATE
SUFFICIENT INSTABILITY TO WARRANT ISOLATED THUNDERSTORMS POSSIBLE.
OTHERWISE...EXPECT CEILINGS TO LOWER TO MVFR FRI NIGHT AS THE FRONT
SLIDES SOUTH WITH REDUCED VISIBILITIES POSSIBLE IN SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH THE FRONT. HIGH PRESSURE BUILDS BACK
IN FROM THE NORTHEAST ON SUN WITH WINDS SHIFTING NE AND AVIATION
CONDITIONS IMPROVING TO VFR.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1130 AM WED...NO CHANGES WITH UPDATE. WEAK WIND SHIFT WITH
SPEEDS 10 KT OR LESS EXPECTED OVER NRN HALF OF AREA WITH SFC TROF
DROPPING IN FROM N-NW. SRN SECTIONS WILL REMAIN S-SW. SEAS REMAINING
3 FT OR LESS.
LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 255 PM WED...HIGH PRESSURE WILL BE SITUATED OFF THE NC COAST
ON THURS NIGHT AND FRI ALLOWING FOR SOUTHWESTERLY FLOW 10-15 KNOTS.
SEAS 1-3 FT WILL BUILD 2-4 FT FOR THE CENTRAL AND NORTHERN WATERS. A
BACK DOOR COLD FRONT WILL SLIDE SOUTH ACROSS THE WATERS SAT
AFTERNOON INTO SAT NIGHT...WITH WINDS VEERING NORTH THEN NORTHEAST
BEHIND THE FRONT. SEAS WILL BUILD 2-4 FT NEARSHORE TO 3 TO 5 FT FOR
THE OUTER WATERS SAT INTO SAT NIGHT. HIGH PRESSURE ACROSS THE
NORTHWESTERN ATLANTIC WILL BUILD SOUTH OVER THE WATERS SUN INTO MON
WITH NORTHEAST WINDS 10 TO 15 KNOTS AND SEAS 2 TO 4 FT. SWAN AND
WAVEWATCH III WERE IN GOOD AGREEMENT THROUGH THE LONG RANGE.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JME
NEAR TERM...JBM
SHORT TERM...JME
LONG TERM...DAG
AVIATION...JBM/DAG
MARINE...JBM/DAG
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
205 PM EDT WED MAR 14 2012
.SYNOPSIS...
A WEAK SURFACE TROUGH WILL MOVE DROP SOUTH INTO THE AREA
TODAY AND DISSIPATE. SURFACE HIGH PRESSURE OFFSHORE WILL CONTINUE
TO INFLUENCE THE WEATHER THROUGH THE REMAINDER OF THE WEEK. A
BACKDOOR COLD FRONT WILL SLIP SOUTH INTO THE AREA THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 145 PM WED...MINOR UPDATE FOR HOURLY TEMPS. DID RAISE MAX
TEMPS UP A FEW DEGS MOST AREAS.
/PREVIOUS DISCUSSION/
AS OF 1130 AM WED...NO MAJOR CHANGES WITH UPDATE. STRATUS/FOG HAVE
DISSIPATED OVER COASTAL PLAINS AND EXPECTING MOSTLY SUNNY SKIES
UNTIL CU DEVELOPMENT OVER INLAND SECTIONS MID AFTN. LATEST RUC AND
HRRR MODELS INDICATE SOME ISOLD CONVECTIVE ACTIVITY IN SEA BREEZE
ZONE...THUS WILL KEEP CURRENT SLGT CHC POPS FOR THAT AREA. TEMPS
CONTINUE TO LAG OVER SRN COASTAL PLAINS WHERE STRATUS LIMITED
MORNING INSOLATION...BUT LATEST LAMP GDNC SUPPORTS TEMPS NEAR 80
THERE BY LATE AFTN.
WEAK WIND SHIFT WITH SFC TROF WILL HAVE LITTLE CONSEQUENCE BUT MAY
PROVIDE ADDITIONAL CONVERGENCE WITH SEA BREEZE ZONE FOR CONVECTIVE
INITIATION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
AS OF 325 AM WEDNESDAY...CLEAR SKIES AND LIGHT WINDS ARE EXPECTED
ACROSS EASTERN NC TONIGHT AS WEAK HIGH PRESSURE RIDGES WEST INTO
THE AREA FROM THE ATLANTIC. DUE TO EXPECTED STRONG RADIATIONAL
COOLING...I TRENDED OVERNIGHT LOWS TO THE COOLER MOS GUIDANCE WITH
READINGS MAINLY IN THE LOWER 50S. WOULD EXPECT POTENTIAL FOR FOG
TO DEVELOP LATE.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 330 AM WED...HIGH PRES WILL BE SITUATED OFF THE COAST THU
WITH SHORTWAVE RIDGING ALOFT PROVIDING FOR DRY WEATHER AND TEMPS
AROUND 15 DEGREES ABOVE NORMAL. HIGHS EXPECTED IN THE U70S/L80S
INLAND TO M/U60S COAST...WHICH IS STILL SEVERAL DEGREES AWAY FROM
RECORD TEMPS FOR THE DAY WHICH IS 89 AT GREENVILLE AND NEW BERN
AND 79 AT CAPE HATTERAS. THE UPPER RIDGE BREAKS DOWN FRI AND SAT
AS A COUPLE SHORTWAVE TROUGH RIDE OVER THE RIDGE. SUFFICIENT
INSTABILITY WILL EXIST ACROSS THE REGION FRI WITH RETURN FLOW
MOISTURE INCREASING AND GRADUAL HEIGHT FALLS ALOFT TO ALLOW FOR
ISOLATED SHOWERS/TSTMS TO DEVELOP MAINLY ACROSS THE COASTAL PLAIN
DURING THE AFTERNOON. BETTER CHANCES FOR SHOWERS AND STORMS
DEVELOP FRI NIGHT INTO SAT AS A STRONGER SHORTWAVE MOVES ACROSS
THE AREA AND A BACKDOOR COLD FRONT DROPS S ACROSS THE REGION.
GREATER CLOUD COVERAGE FRI WILL BRING TEMPS A COUPLE DEGREES
COOLER THAN THU WITH ADDITIONAL SLIGHT COOLING SAT...MAINLY
M/U70S INLAND FRI AND M70S SAT TO M/U60S COAST EACH DAY.
LONGWAVE RIDGING BUILDS ACROSS THE ERN CONUS SUN THROUGH THE
REMAINDER OF THE LONG TERM BUT MODELS STILL STRUGGLING WITH THE
EVOLUTION OF THE UPPER TROUGH AS IT MIGRATES SWD ACROSS THE WRN N
ATLANTIC. LATEST MODELS TRENDING FARTHER OFFSHORE WITH THE TROUGH
OR POSSIBLE UPPER LEVEL CUT-OFF LOW SO WILL KEEP THE FORECAST DRY
SUN-TUE AT THIS TIME. HIGH PRES RIDGES IN FROM OFF THE MID
ATLANTIC COAST BRINGING NE/ELY ONSHORE FLOW HOLDING TEMPS IN THE
L/M70S INLAND TO L/M60S COAST DESPITE STRONG UPPER RIDGING.
&&
.AVIATION /18Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /18Z TODAY THROUGH 18Z THURSDAY/...
AS OF 130 PM WED...HIGH CONFIDENCE IN VFR PREVAILING THROUGH THIS
EVENING. ISOLD TSTM CANNOT BE RULED OUT WITH SEA BREEZE THIS AFTN
BUT NOT ENOUGH THREAT TO INCLUDE IN TAFS. EXCELLENT RADIATIONAL
COOLING IS EXPECTED TONIGHT WHICH SHOULD LEAD TO THE DEVELOPMENT OF
PATCHY FOG AND SUB VFR VISIBILITIES. UPS FOG TOOL INDICATES
POTENTIAL FOR DENSE FOG (<1 SM) ALL BUT KPGV WITH CROSSOVER TEMPS
BEING REACHED...BUT NOT ENOUGH FCST CONFIDENCE TO INDICATE IFR VSBYS
WITH THIS FCST ISSUANCE.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 315 AM WED...HIGH PRES WILL ALLOW VFR CONDITIONS TO DOMINATE
THU AND FRI ALTHOUGH COULD SEE PATCHY LATE NIGHT/EARLY MORNING
FOG. THE NEXT CHANCE FOR SHOWERS EXPECTED FRI NIGHT AND SAT WHICH
WILL LIKELY BRING SOME REDUCED CIGS OR VSBYS. LONGWAVE UPPER
RIDGING BUILDS IN FROM THE W SUN WITH SFC HIGH PRES RIDGING IN
FROM THE NORTHEAST SUN ALLOWING FOR PREDOMINANTLY VFR CONDITIONS.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1130 AM WED...NO CHANGES WITH UPDATE. WEAK WIND SHIFT WITH
SPEEDS 10 KT OR LESS EXPECTED OVER NRN HALF OF AREA WITH SFC TROF
DROPPING IN FROM N-NW. SRN SECTIONS WILL REMAIN S-SW. SEAS REMAINING
3 FT OR LESS.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 315 AM WED...WEAK HIGH PRES WILL BE SITUATED OFF THE COAST
THU WITH LIGHT SLY WINDS ACROSS THE WATERS. THE HIGH SLIDES
FARTHER OFFSHORE LATE FRI AS A COLD FRONT APPROACHES FROM THE NW.
GRADIENTS TIGHTEN IN ADVANCE OF THE FRONT TO 10-20 KT BY LATE FRI
AND CONTINUING INTO EARLY SAT. THE FRONT CURRENTLY PROGGED TO PUSH
S ACROSS THE WATERS SAT EVENING WITH NELY FLOW DEVELOPING SUN.
SEAS GENERALLY 2-3 FT THU TO FRI AM...THEN BUILD TO 3-5 FT LATE
FRI INTO SAT. AN EXTENDED NE FETCH DEVELOPS ACROSS THE WRN NORTH
ATLANTIC LATE SAT AND SUN WHICH WILL MAINTAIN 3-5 FT SEAS ACROSS
THE WATERS AND COULD REACH MINIMAL SCA CRITERIA LATE SUN IF AN
ARE OF LOW PRES DEVELOPS ACROSS THE OFFSHORE WATERS AS DEPICTED BY
THE GFS...HOWEVER LONG RANGE MODELS NOT IN GOOD AGREEMENT WITH
DETAILS IN THE PATTERN OFF THE COAST EARLY NEXT WEEK.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JME
NEAR TERM...JBM
SHORT TERM...JME
LONG TERM...SK
AVIATION...JBM/SK
MARINE...JBM/SK
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1155 AM EDT WED MAR 14 2012
.SYNOPSIS...
A WEAK SURFACE TROUGH WILL MOVE DROP SOUTH INTO THE AREA
TODAY AND DISSIPATE. SURFACE HIGH PRESSURE OFFSHORE WILL CONTINUE
TO INFLUENCE THE WEATHER THROUGH THE REMAINDER OF THE WEEK. A
BACKDOOR COLD FRONT WILL SLIP SOUTH INTO THE AREA THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1130 AM WED...NO MAJOR CHANGES WITH UPDATE. STRATUS/FOG HAVE
DISSIPATED OVER COASTAL PLAINS AND EXPECTING MOSTLY SUNNY SKIES
UNTIL CU DEVELOPMENT OVER INLAND SECTIONS MID AFTN. LATEST RUC AND
HRRR MODELS INDICATE SOME ISOLD CONVECTIVE ACTIVITY IN SEA BREEZE
ZONE...THUS WILL KEEP CURRENT SLGT CHC POPS FOR THAT AREA. TEMPS
CONTINUE TO LAG OVER SRN COASTAL PLAINS WHERE STRATUS LIMITED
MORNING INSOLATION...BUT LATEST LAMP GDNC SUPPORTS TEMPS NEAR 80
THERE BY LATE AFTN.
WEAK WIND SHIFT WITH SFC TROF WILL HAVE LITTLE CONSEQUENCE BUT MAY
PROVIDE ADDITIONAL CONVERGENCE WITH SEA BREEZE ZONE FOR CONVECTIVE
INITIATION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
AS OF 325 AM WEDNESDAY...CLEAR SKIES AND LIGHT WINDS ARE EXPECTED
ACROSS EASTERN NC TONIGHT AS WEAK HIGH PRESSURE RIDGES WEST INTO
THE AREA FROM THE ATLANTIC. DUE TO EXPECTED STRONG RADIATIONAL
COOLING...I TRENDED OVERNIGHT LOWS TO THE COOLER MOS GUIDANCE WITH
READINGS MAINLY IN THE LOWER 50S. WOULD EXPECT POTENTIAL FOR FOG
TO DEVELOP LATE.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 330 AM WED...HIGH PRES WILL BE SITUATED OFF THE COAST THU
WITH SHORTWAVE RIDGING ALOFT PROVIDING FOR DRY WEATHER AND TEMPS
AROUND 15 DEGREES ABOVE NORMAL. HIGHS EXPECTED IN THE U70S/L80S
INLAND TO M/U60S COAST...WHICH IS STILL SEVERAL DEGREES AWAY FROM
RECORD TEMPS FOR THE DAY WHICH IS 89 AT GREENVILLE AND NEW BERN
AND 79 AT CAPE HATTERAS. THE UPPER RIDGE BREAKS DOWN FRI AND SAT
AS A COUPLE SHORTWAVE TROUGH RIDE OVER THE RIDGE. SUFFICIENT
INSTABILITY WILL EXIST ACROSS THE REGION FRI WITH RETURN FLOW
MOISTURE INCREASING AND GRADUAL HEIGHT FALLS ALOFT TO ALLOW FOR
ISOLATED SHOWERS/TSTMS TO DEVELOP MAINLY ACROSS THE COASTAL PLAIN
DURING THE AFTERNOON. BETTER CHANCES FOR SHOWERS AND STORMS
DEVELOP FRI NIGHT INTO SAT AS A STRONGER SHORTWAVE MOVES ACROSS
THE AREA AND A BACKDOOR COLD FRONT DROPS S ACROSS THE REGION.
GREATER CLOUD COVERAGE FRI WILL BRING TEMPS A COUPLE DEGREES
COOLER THAN THU WITH ADDITIONAL SLIGHT COOLING SAT...MAINLY
M/U70S INLAND FRI AND M70S SAT TO M/U60S COAST EACH DAY.
LONGWAVE RIDGING BUILDS ACROSS THE ERN CONUS SUN THROUGH THE
REMAINDER OF THE LONG TERM BUT MODELS STILL STRUGGLING WITH THE
EVOLUTION OF THE UPPER TROUGH AS IT MIGRATES SWD ACROSS THE WRN N
ATLANTIC. LATEST MODELS TRENDING FARTHER OFFSHORE WITH THE TROUGH
OR POSSIBLE UPPER LEVEL CUT-OFF LOW SO WILL KEEP THE FORECAST DRY
SUN-TUE AT THIS TIME. HIGH PRES RIDGES IN FROM OFF THE MID
ATLANTIC COAST BRINGING NE/ELY ONSHORE FLOW HOLDING TEMPS IN THE
L/M70S INLAND TO L/M60S COAST DESPITE STRONG UPPER RIDGING.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /06Z TODAY THROUGH 12Z THURSDAY/...
AS OF 705 AM WEDNESDAY...DRIER AIR HAS MOVED INTO EASTERN NC WITH
CLEAR SKIES. WINDS NEVER FULLY DECOUPLED OVERNIGHT SO THREAT FOR
DENSE FOG IS OVER ALTHOUGH WE COULD SEE A BRIEF PERIOD OF MVFR
VISIBILITIES IN LIGHT FOG THROUGH 13Z. ISOLATED SEA BREEZE
CONVECTION IS POSSIBLE DURING PEAK HEATING IF CELLS CAN OVERCOME
DRY AIR IN THE MID LEVELS AND DRY DOWN SLOPE FLOW AT THE SURFACE.
EXCELLENT RADIATIONAL COOLING IS EXPECTED TONIGHT WHICH SHOULD
LEAD TO THE DEVELOPMENT OF PATCHY FOG AND SUB VFR VISIBILITIES.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 315 AM WED...HIGH PRES WILL ALLOW VFR CONDITIONS TO DOMINATE
THU AND FRI ALTHOUGH COULD SEE PATCHY LATE NIGHT/EARLY MORNING
FOG. THE NEXT CHANCE FOR SHOWERS EXPECTED FRI NIGHT AND SAT WHICH
WILL LIKELY BRING SOME REDUCED CIGS OR VSBYS. LONGWAVE UPPER
RIDGING BUILDS IN FROM THE W SUN WITH SFC HIGH PRES RIDGING IN
FROM THE NORTHEAST SUN ALLOWING FOR PREDOMINANTLY VFR CONDITIONS.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1130 AM WED...NO CHANGES WITH UPDATE. WEAK WIND SHIFT WITH
SPEEDS 10 KT OR LESS EXPECTED OVER NRN HALF OF AREA WITH SFC TROF
DROPPING IN FROM N-NW. SRN SECTIONS WILL REMAIN S-SW. SEAS REMAINING
3 FT OR LESS.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 315 AM WED...WEAK HIGH PRES WILL BE SITUATED OFF THE COAST
THU WITH LIGHT SLY WINDS ACROSS THE WATERS. THE HIGH SLIDES
FARTHER OFFSHORE LATE FRI AS A COLD FRONT APPROACHES FROM THE NW.
GRADIENTS TIGHTEN IN ADVANCE OF THE FRONT TO 10-20 KT BY LATE FRI
AND CONTINUING INTO EARLY SAT. THE FRONT CURRENTLY PROGGED TO PUSH
S ACROSS THE WATERS SAT EVENING WITH NELY FLOW DEVELOPING SUN.
SEAS GENERALLY 2-3 FT THU TO FRI AM...THEN BUILD TO 3-5 FT LATE
FRI INTO SAT. AN EXTENDED NE FETCH DEVELOPS ACROSS THE WRN NORTH
ATLANTIC LATE SAT AND SUN WHICH WILL MAINTAIN 3-5 FT SEAS ACROSS
THE WATERS AND COULD REACH MINIMAL SCA CRITERIA LATE SUN IF AN
ARE OF LOW PRES DEVELOPS ACROSS THE OFFSHORE WATERS AS DEPICTED BY
THE GFS...HOWEVER LONG RANGE MODELS NOT IN GOOD AGREEMENT WITH
DETAILS IN THE PATTERN OFF THE COAST EARLY NEXT WEEK.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JME
NEAR TERM...JBM
SHORT TERM...JME
LONG TERM...SK
AVIATION...JME/SK
MARINE...JBM/SK
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
105 PM CDT WED MAR 14 2012
.AVIATION...
FOR THE 18Z TAFS...LOW VFR CIGS ARE EXPECTED TO REMAIN IN PLACE
OVER ALL TAF SITES THROUGH THIS EVENING. ISOLATED THUNDERSTORM
CHANCES AND MVFR CIGS OVERNIGHT ARE THE PRIMARY FORECAST
CONCERNS.
REGARDING THUNDERSTORM CHANCES...MORNING HOURLY RUNS OF THE HRRR
CONSISTENTLY FORECAST THE DEVELOPMENT OF ISOLATED THUNDERSTORMS
ACROSS NORTH TEXAS. THE NAM SEEMS TO BE ON BOARD WITH THIS
SOLUTION AS WELL...HOWEVER A 1650Z AIRCRAFT SOUNDING AT KDFW
INDICATED THAT A SUBSTANTIAL CAP REMAINS IN PLACE AT THE H850
LEVEL. ASSUMING THIS SOUNDING IS REPRESENTATIVE...WE WOULD NEED TO
EITHER WARM UP 10 DEG F OR SUBSTANTIALLY LIFT THE CAP FOR
THUNDERSTORMS TO DEVELOP NEAR THE METROPLEX THIS AFTERNOON. BOTH
OF THESE SCENARIOS LOOK UNLIKELY FOR TODAY...SO WILL LEAVE TSTMS
OUT OF THE TAFS AT THIS TIME AND MONITOR FOR DEVELOPMENT.
REGARDING CIGS...GUIDANCE ONCE AGAIN BRINGS IFR FLIGHT CATEGORY
RESTRICTIONS TO AREA TAF SITES AROUND SUNRISE THURSDAY MORNING.
BECAUSE OUR ENVIRONMENTAL CONDITIONS ARE NOT GOING TO CHANGE MUCH
IN THE NEXT 24 TO 36 HRS OPTED TO GO AHEAD WITH A FORECAST SIMILAR
TO WHAT WAS OBSERVED THIS MORNING. THIS MORNING CIGS STRUGGLED TO
FALL BELOW 2 KFT...SO MAINTAINED AN OPTIMISTIC FORECAST KEEPING
CIGS ABOVE 2 KFT AROUND SUNRISE. OTHERWISE THINK CIGS WILL REMAIN
LOW VFR FOR MUCH OF THE FORECAST PERIOD.
CAVANAUGH
&&
.UPDATE...
TEMPERATURES THIS MORNING STARTED OUT PRETTY WARM FOR THIS TIME OF
YEAR WITH TEMPERATURES GENERALLY IN THE MID TO UPPER 60S. MOSTLY
CLOUDY SKIES WILL PREVAIL AGAIN TODAY AND THUS IT WILL AGAIN BE
TOUGH TO DESTABILIZE THE ATMOSPHERE THIS AFTERNOON.
HOWEVER...THERE ARE MORE BREAKS IN THE CLOUDS THIS MORNING WHICH
SHOULD YIELD SLIGHTLY WARMER LOW LEVEL TEMPS LATER TODAY. WITH
WEAK SHORTWAVES MOVING OVERHEAD AND A RELATIVELY STRONGER
SHORTWAVE EVIDENT NEAR THE EL PASO AREA...WILL INCLUDE A MENTION
FOR ISOLATED SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING.
ONCE AGAIN...IF A STORM CAN DEVELOP...IT WILL HAVE THE POTENTIAL TO
BECOME STRONG TO MARGINALLY SEVERE. OTHERWISE...ADJUSTED
TEMPERATURES DOWN A FEW DEGREES IN THE WEST WHERE THICK CLOUD
COVER SHOULD PERSIST FOR MUCH OF THE DAY.
82/JLD
&&
.PREV DISCUSSION... /ISSUED 336 AM CDT WED MAR 14 2012/
UPPER LEVEL RIDGING AND PERSISTENT SOUTHERLY LOW LEVEL FLOW WILL
LEAD TO ABOVE-NORMAL TEMPERATURES ACROSS NORTH AND CENTRAL TEXAS
FOR THE NEXT SEVERAL DAYS. WITH ABUNDANT LOW LEVEL MOISTURE IN
PLACE...THERE IS SOME CONCERN FOR FOG DEVELOPMENT DURING THE
EARLY MORNING HOURS AS TEMPERATURES APPROACH DEWPOINT READINGS. IN
FACT THE LAST FEW HRRR CYCLES HAVE HINTED AT LOWERING VISIBILITIES
ACROSS PARTS OF THE AREA PRIOR TO SUNRISE. HOWEVER...WITH WINDS
REMAINING MAINLY IN THE 10-15 MPH RANGE...FEEL WE WILL BE DEALING
MAINLY WITH LOW STRATUS AND SURFACE VISIBILITIES SHOULD REMAIN
OVERALL OKAY.
THE NEXT CHALLENGE WILL BE POPS FOR NOW THROUGH NEXT WEEK. THE
ATMOSPHERE IS UNSTABLE TODAY WITH MODEL FORECAST SB CAPE APPROACHING
1500 J/KG THIS AFTERNOON. NAM ALSO ERODES THE CAP ALMOST
COMPLETELY BY MID AFTERNOON...WHILE GFS HOLDS ONTO A GOOD AMOUNT
OF CIN. BELIEVE THAT WITH THE LACK OF A TRIGGER OR ANY UPPER LEVEL
SUPPORT...CONVECTION WILL HAVE A DIFFICULT TIME TODAY AND WILL
KEEP POPS BELOW 20 PERCENT WITHOUT ANY MENTION OF PRECIP IN THE
FORECAST. A SUBTLE SHORTWAVE WILL THEN PASS OVERHEAD DURING THE
DAY TOMORROW. FEEL THIS WILL ALLOW FOR THE DEVELOPMENT OF AT LEAST
ISOLATED STORMS. FOR NOW WILL LEAVE 20 POPS IN AREAWIDE AND REFINE
IF NEEDED LATER. THE UPPER DISTURBANCE SHIFTS EAST OF THE AREA
ALONG WITH THE ASSOCIATED PRECIPITATION THURSDAY NIGHT.
BY FRIDAY IT LOOKS LIKE THE RIDGE WILL BE TOO STRONG FOR
SIGNIFICANT RAIN CHANCES. ONE THING TO KEEP AN EYE ON WILL BE
DRYLINE DEVELOPMENT TO OUR NORTHWEST FRIDAY EVENING. AT THIS TIME
IT LOOKS LIKE ANY ACTIVITY THAT GETS GOING SHOULD DIMINISH BEFORE
REACHING THE AREA FRIDAY NIGHT. IF ANYTHING HOLDS TOGETHER AN
UPWARD ADJUSTMENT OF POPS MAY BE NEEDED LATE FRIDAY FOR THE
NORTHWESTERN COUNTIES.
THE UPPER RIDGE WILL BEGIN TO SLOWLY BREAK DOWN OVER THE WEEKEND
AS A LARGE SCALE UPPER TROUGH DEVELOPS OVER THE WESTERN CONUS.
ISOLATED SHOWERS AND STORMS WILL BE POSSIBLE BOTH SATURDAY AND
SUNDAY...ESPECIALLY DURING PEAK HEATING IN THE AFTERNOON. RAIN
CHANCES WILL THEN INCREASE SIGNIFICANTLY EARLY NEXT WEEK AS THE
UPPER TROUGH DIGS SOUTHEASTWARD TOWARDS THE REGION. GFS AND ECMWF
ARE SIMILAR WITH THE EVOLUTION OF THIS SYSTEM WITH ONLY MINOR
VARIATIONS IN THE TIMING. LARGE SCALE ASCENT AHEAD OF THE SYSTEM
SHOULD LEAD TO WIDESPREAD PRECIPITATION BY MONDAY OR MONDAY NIGHT.
MODELS ARE SHOWING NEGATIVE TILT...AND RESPECTIVE MODEL SOUNDINGS
AND HODOGRAPHS APPEAR CONDUCIVE FOR SEVERE WEATHER POTENTIAL. IT
IS STILL FAR TOO EARLY FOR ANY SPECIFICS BUT CERTAINLY WORTH
WATCHING AS THE FIRST DAYS OF SPRING DRAW NEAR. LONG RANGE
GUIDANCE THEN POINTS TOWARDS TEMPERATURES FINALLY RETURNING TO
NEAR-NORMAL AROUND THE MIDDLE OF NEXT WEEK AS THE AFOREMENTIONED
UPPER TROUGH SHOVES EAST OF THE AREA AND THE NEXT FRONT MOVES
THROUGH.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 77 66 78 66 77 / 10 10 20 10 10
WACO, TX 78 67 78 64 77 / 10 10 20 10 10
PARIS, TX 78 62 77 60 77 / 10 10 20 20 10
DENTON, TX 77 67 78 64 77 / 10 10 20 10 10
MCKINNEY, TX 77 67 77 65 77 / 10 10 20 20 10
DALLAS, TX 77 67 78 65 77 / 10 10 20 10 10
TERRELL, TX 78 66 78 64 77 / 10 10 20 20 10
CORSICANA, TX 78 65 78 64 78 / 10 10 20 10 10
TEMPLE, TX 78 66 78 64 77 / 10 10 20 10 10
MINERAL WELLS, TX 76 63 79 63 77 / 10 10 20 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
521 PM CDT WED MAR 14 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY.
THE MAIN CONCERNS IN THE SHORT TERM ARE CHANCES FOR
CONVECTION...LOW CLOUDS AND FOG TONIGHT AND LOW CLOUDS AND
TEMPERATURES ON THURSDAY.
SURFACE ANALYSIS AT 19Z SHOWED A NORTHEAST TO SOUTHWEST COLD
FRONT ACROSS NORTHWEST WISCONSIN. TEMPERATURES AHEAD OF THE FRONT
WERE MAINLY IN THE 60S AND 70S...WITH 40S AND 50S DEW POINTS. A
LAKE BREEZE DEVELOPED AND DROPPED TEMPERATURES IN THE LAKESHORE
COUNTIES INTO THE 50S WITH 40S DEW POINTS. MESOANALYSIS HAD
SURFACE BASED CAPE VALUES IN THE 1000-1500J/KG RANGE IN THE
SOUTHERN PART OF THE FORECAST AREA WHERE 150-300J/KG OF SURFACE
BASED CIN. MODELS ALL SHOWED RATHER STEEP MID LEVEL LAPSE RATES.
THE 12Z GFS AND 09Z SREF HAD QPF IN THE AREA AHEAD OF THE
APPROACHING SURFACE FRONT...THE 12Z ECMWF HAD A LITTLE QPF IN
NORTHEAST WISCONSIN OVERNIGHT. THE 12Z NAM KEPT THE AREA DRY
THROUGH THE SHORT TERM FORECAST PERIOD. 12Z MAV AND 12Z MET BOTH
HAD EXTREMELY LOW POPS. AM CONCERNED ABOUT POTENTIAL CONVECTION
AHEAD OF THE FRONT...BUT ONLY WENT WITH SLIGHT CHANCE POPS FOR THE
EVENING IN THE EAST.
12Z MOS GUIDANCE HAD DENSE FOG AND STRATUS FOR THE GREEN BAY
AREA LATER TONIGHT INTO THURSDAY MORNING. NOT REALLY SEEING
STRATUS BUT LIGHT ONSHORE WINDS AND HIGH DEW POINTS SHOULD BE SUFFICIENT
TO AT LEAST GET SOME FOG. THE FRONT STALLS SOUTH OF THE FORECAST
AREA SO WINDS WILL BE COMING OFF THE LAKE AND BAY...HOLDING
TEMPERATURES DOWN ON THURSDAY. HAVE HIGHS MAINLY IN THE UPPER 50S
TO UPPER 60S AWAY FROM THE LAKE AND IN THE 50S NEAR LAKE MICHIGAN.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY.
PERSISTENT RIDGE ACROSS THE EASTERN UNITED STATES WILL CONTINUE TO BRING
ABOVE NORMAL TEMPERATURES DURING THE PERIOD. COLD FRONT THAT IS EXPECTED
TO MOVE ACROSS THE AREA TONIGHT WILL SHIFT BACK NORTHWARD AS A
WARM FRONT ON SATURDAY. AFTER A BRIEF COOL DOWN ON FRIDAY...TEMPERATURES
WILL AGAIN WARM WELL INTO THE 60S AND 70S AWAY FROM THE BAY AND LAKE.
RECORD HIGH TEMPERATURES ARE POSSIBLE EACH DAY AT SOME LOCATIONS
FROM SATURDAY THROUGH TUESDAY...ESPECIALLY AWAY FROM THE BAY AND
LAKE. COOLER BY THE LAKE WORDING WILL ALSO BE NEEDED EACH DAY AS
SOUTHERLY FLOW IS EXPECTED. NOT ENOUGH EVIDENCE IN THE MODEL DATA WHERE
WINDS WOULD TURN OFFSHORE TO ALLOW FOR THE IMMEDIATE LAKESHORE
COMMUNITIES TO WARM INTO THE 60S AND 70S.
OTHERWISE...SUMMER LIKE PATTERN WITH WEAK DISTURBANCES ROTATING
AROUND THE BACKSIDE OF THE RIDGE. TRYING TO TIME THESE FEATURES
TOUGH THIS FAR IN ADVANCE. DO THINK SHORTWAVE ENERGY FRIDAY NIGHT
INTO SATURDAY MORNING IS WORTH MENTIONS IN THE ZONE FORECAST PRODUCT.
WOULD HAVE GONE HIGHER POPS WITH THIS FEATURE...BUT TIMING AND LOCATION
ISSUES KEPT CHANCES A LOWER THAN WHAT HAVE LIKED. FIGURE THIS FEATURE
WILL BRING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS TO THE REGION.
REMAINDER OF THE EXTENDED HAS SMALL CHANCES FOR SHOWERS AND STORMS THAT
WILL NOT SHOW UP IN THE ZONES FOR MOST PERIODS. LOW CONFIDENCE ON TIMING
OF THE SMALL SCALE FEATURES ON TRIGGERING SHOWERS AND STORMS.
&&
.AVIATION...LOW CONFIDENCE IN CIG AND VSBY FCST FOR 00Z TAFS.
MODELS VERY INSISTENT THAT LOW CLDS AND VSBYS WL BECOME AN ISSUE
OVERNIGHT...IN THE WAKE OF COLD FRONT SLIPPING SWD THROUGH THE
RGN. THE PROBLEM IS...NO SIGN OF THIS HAPPENING YET ON VISIBLE STLT
IMAGERY. PLUS...BY 22Z THE RUC WAS FCSTG VSBYS BLO 1/4 SM OVER
MUCH OF WRN UPR MICHIGAN...AND THE VSREF HAS A GREATER THAN 70
PCT CHC OF VSBYS BLO 1SM IN THAT AREA. THAT IS THE SAME AREA WHICH
IS BASICALLY CLR ON THE STLT...AND HAS SFC DEW POINT DEPRESSIONS
OF NEARLY 25 F DEG RIGHT NOW.
CAN STILL SEE THE CASE FOR LOWER CLDS AND SOME FG DEVELOPING AS
SHALLOW COLD AIR MASS SLIPS SWD ACRS THE AREA. BUT IT CLEARLY IS
GOING TO TAKE LONGER THAN INDICATED BY THE GUID. WL PUSH BACK
TIMING...AND THEN LINGER LONGER INTO TOMORROW AS ELY FLOW
CONTINUES. WL CONT TO MONITOR TRENDS THIS EVENING...AND IF
NOTHING IS DEVELOPING BY THE TIME THE 06Z TAF ISSUANCE COMES
ARND...WL NEED TO SERIOUSLY CONSIDER BACKING OFF ON THE LOW CLDS
IN THE WAKE OF THE FRONT.
SKOWRONSKI
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
340 PM CST WED MAR 14 2012
.VERY SHORT TERM...TONIGHT AND THURSDAY.
CHALLENGING FORECAST WITH HIGH UNCERTAINTY IN A WEAK THUNDERSTORM
CHANCE...FOG/STRATUS DEVELOPMENT...AND THURSDAY MAX TEMPERATURES.
WARM AIR AND LOW LEVEL MOISTURE STREAMED INTO SOUTHERN WI THIS
AFTERNOON AHEAD OF A LOW PRESSURE TROUGH CURRENTLY SITUATED FROM
WESTERN LAKE SUPERIOR INTO WESTERN IOWA. THE STRATUS IN NORTHEAST
IOWA AND FAR WESTERN WI STAYED OUT OF THE FORECAST AREA IN THE
AFTERNOON...PROVING THAT WE WERE UNDER A WELL-MIXED ENVIRONMENT.
CUMULUS CLOUDS DEVELOPED ACROSS SOUTHERN WI LATE THIS AFTERNOON AT
THE TOP OF THE MIXED LAYER...AROUND 3500 TO 4000 FEET AGL. THE CU
ARE VERY SHALLOW DUE TO THE CAP. MAINTAINED THE SLIGHT CHANCE FOR
THUNDERSTORMS FROM MID EVENING THROUGH LATE TONIGHT BUT VERY LOW
CONFIDENCE IN THIS OCCURRING. THE HRRR AND SPC 4 KM WRF NMM SHOW A
FEW SHOWERS BREAKING OUT. GIVEN THE INSTABILITY WITH CAPE OVER 1000
J/KG...KEPT WITH THE TSTORM THINKING. HOWEVER THE CHANCE IS VERY
LOW. THERE IS VERY LITTLE UPPER LEVEL FORCING AND NO UPPER LEVEL
MOISTURE TO WORK WITH.
THE NEXT CHALLENGE IS THE POSSIBILITY FOR FOG AND STRATUS TO DEVELOP
LATE TONIGHT/THU MORNING. VERY LOW CONFIDENCE IN THIS SCENARIO...BUT
IT IS HARD TO IGNORE THE PERSISTENT MOS GUIDANCE SUGGESTING DENSE
FOG. GIVEN DEWPOINT TEMPS IN THE MID/UPPER 50S THIS AFTERNOON
/CROSSOVER TEMPS/ AND FORECAST TEMPS TO COOL LATE TONIGHT AS
THE TROUGH/WEAK PRESSURE GRADIENT COMES OVERHEAD...THERE IS
POTENTIAL FOR FOG TO DEVELOP AND POSSIBLY BECOME DENSE. IT IS
DIFFICULT TO PICTURE THIS SCENARIO SINCE THE ATMOSPHERE HAS BEEN SO
DRY AND TEMPS ARE SO WARM TODAY THAT THEY MAY NOT DROP BELOW THE
CROSSOVER TEMPS...ESPECIALLY IN THE SOUTHERN FORECAST AREA.
THEREFORE...DID NOT ISSUE A DENSE FOG ADVISORY...BUT MENTIONED AREAS
OF FOG WITH PATCHY DENSE FOG IN FORECAST LATE TONIGHT INTO THUR
MORNING.
A BACK DOOR COLD FRONT WILL ZIP DOWN LAKE MICHIGAN MID THU MORNING.
THE CANADIAN MODEL IS QUICKER WITH THE WIND SHIFTING TO THE
NORTHEAST THAN THE NAM. WINDS SHOULD INCREASE ALONG THE LAKESHORE
WITH THE FRONT...THEN REMAIN SOMEWHAT ELEVATED AROUND 10 KNOTS
THROUGH THE MID AFTERNOON WITH THE STRONGER PRESSURE GRADIENT. THIS
COLD FRONT SCENARIO PAINTS A DREARY PICTURE FOR MILWAUKEE ON
THURSDAY. CAN/T RULE OUT DRIZZLE WITH LOW CLOUDS...GUSTY NORTHEAST
WINDS FOR A TIME AND COOL TEMPERATURES FROM THE LAKE. LAKE MICHIGAN
TEMPS WERE BETWEEN 37 AND 40 DEGREES FAHRENHEIT PER MODIS IMAGERY
YESTERDAY EVENING.
UNCERTAIN HOW FAR INTO SOUTH CENTRAL WI THE FRONT WILL MAKE IT ON
THU. THE CANADIAN BRINGS IT ALL THE WAY TO MSN AND THE NAM DOES NOT.
TRIED TO BLEND THE TWO MODEL SOLUTIONS FOR TEMPS AND WINDS.
.SHORT TERM...THURSDAY NIGHT THROUGH SATURDAY.
WL CONTINUE TO LEAN MORE ON HIGHER RESOLUTION NAM SOLUTION FOR THIS
PERIOD...WITH SURFACE FRONTAL BOUNDARY NUDGED FARTHER SOUTH DEEPER
INTO NRN IL AT START OF PERIOD. WITH MOIST LIGHT LOW LEVEL
NORTHEAST FLOW BELOW INVERSION EXPCD TO CONTINUE...WL CARRY FOG
MENTION THRU THURSDAY NIGHT...AND CONFINE TO THE EAST...CLOSER TO
COOL LAKE MI ON FRI. MAY BE UNDERDOING AMOUNT OF CLOUD COVER NORTH
OF FRONTAL BOUNDARY DUE TO MOIST LOW LEVEL NORTHEAST FLOW BUT
CONCERNED ABOUT DRY AIR ENTRAINMENT FROM THE NORTH THU NGT INTO
FRI. DEWPTS FALL INTO THE TEENS AND 20S BEHIND THE FRONT IN THE NRN
PLAINS. FOG SHOULD BEGIN TO BREAK UP AS BOUNDARY LAYER GETS BETTER
MIXED FRIDAY MRNG.
FRONTAL BOUNDARY BEGINS TO SHIFT NORTHWARD LATER FRIDAY AND FRIDAY
NIGHT IN RESPONSE TO INCREASING LOW LEVEL SW FLOW. CAPPING DOES
DECREASE FRI AFTN BUT LACK OF ANY TRIGGER PRECLUDES ADDING ANY POPS
FOR NOW. BETTER CHANCE APPEARS FRI NIGHT AS MID LEVEL WARM AIR
ADVECTION INCREASES ALONG WITH ELEVATED MOISTURE. COINCIDENTALLY...
WEAK MID LEVEL SHORT WAVE CAUGHT IN SOUTHWEST FLOW MOVES THRU SRN
WI. WEAK LAYER Q-VECTOR CONVERGENCE BRUSHES SRN WI AS WELL...SO
ENUF EVIDENCE TO WARRENT ADDING SCHC POPS FRI NGT...CARRYING INTO
SAT. BULK OF SAT SHOULD BE DRY HOWEVER AS WK FORCING WL HAVE
SHIFTED TO THE NORTHEAST EARLY. SAT EXPCD TO BE WARMER MOST
LOCATIONS WITH BETTER SLY SFC WINDS.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY.
NO SIGNIFICANT CHANGES PLANNED FOR THIS PERIOD. APPEARS
AMPLIFYING UPSTREAM LONG-WAVE TROFFING WL CONTINUE TO BRING WARM
SOUTHERLY FLOW AND RESULTING UNSEASONABLY WARM TEMPERATURES TO MOST
OF SRN WI FOR THE BULK OF THIS PERIOD. RIGHT THROUGH 00Z/22...GFS
500H 5 DAY MEAN HEIGHTS REMAIN 100 TO 200 METERS ABV NORMAL ACRS SRN
WI. HOWEVER...GFS DIVERGING FROM OTHER LONG RANGE GUIDANCE LATER IN
THE EXTENDED PERIOD. ECMWF HAS BEEN TRENDING TOWARD MORE
PROGRESSIVE PATTERN MID-WEEK WITH UPSTREAM PIECE OF ENERGY DIGGING
INTO BACK SIDE OF LONG WAVE TROUGH ON TUESDAY. THIS RESULTS IN LONG
WAVE TROUGH EDGING SLOWLY EWD THRU CENTRAL CONUS...WITH SFC FRONT
MOVING THRU AREA LATE TUE NGT AND WED.
MEANWHILE...LAST SEVERAL DETERMINISTIC RUNS OF THE GFS HAVE TRENDED
TOWARD PERSISTENT BLOCKING HIGH OVER ERN CONUS CONTINUING THROUGH
MID-WEEK...PREVENTING EWD PROGRESSION OF LONG WAVE TROUGH. AS A
RESULT...GFS TRENDING TOWARD CUT-OFF UPPER LOW DEVELOPING OVER THE
SRN PLAINS. THIS UPPER LOW WOULD EVENTUALLY GET NUDGED NORTHEAST
INTO THE UPPER MIDWEST LATER IN THE WEEK BY UPSTREAM KICKER PUSHING
TOWARD WEST COAST WED NGT AND THU. GFS ENSEMBLE MEMBERS FAVORING
CUTOFF LOW...BUT SEVERAL MEMBERS LEAN TOWARD MORE PROGRESSIVE
SOLUTION. HPC LEANING TOWARD ECMWF SOLUTION...BUT SLOWER EWD
PROGRESSION...WHICH WOULD BE REASONABLE CONSIDERING BLOCKING RIDGE
TO THE EAST. FOR NOW...CONFIDENCE WL BE LOWEST IN THE LATE PERIODS
OF THE EXTENDED.
TEMPERATURES EARLY NEXT WEEK WILL BE WILL BE FLIRTING WITH RECORD
HIGHS INLAND...WHILE LAKE MICHIGAN KEEPS LAKESHORE TEMPERATURES
CONSIDERABLY COOLER. LATEST MODIS IMAGES SHOW LAKE MI LAKE SFC
TEMPERATURE REMAINING THE UPPER 30S TO LOW 40S.
FOR MUCH OF THE EXTENDED PERIOD...UPPER LEVEL HEIGHT AND LOW LEVEL
TEMPERATURE ANOMOLIES BETWEEN 3 AND 4 STANDARD DEVIATIONS.
IN THE EARLIER PERIODS OF THE EXTENDED...WL CONTINUE LOW POPS FOR
THUNDER SAT NGT INTO SUN AS PIECE OF MID-LEVEL ENERGY MOVES
NORTHEAST ACROSS THE REGION. WARM MID-LEVEL AIR OVERSPREADS SRN WI
AFTER THIS DISTURBANCE. CAPPING INVERSION PREVENTS ANY SIGNIFICANT
PRPN THREAT EARLY NEXT WEEK...WITH LIMITED MOISTURE.
&&
.AVIATION /00Z TAFS/...
ALTHOUGH A SLIGHT CHANCE OF A THUNDERSTORM EXISTS THIS EVENING...DUE
TO THE LACK OF FORCING WILL KEEP THE TAF FORECASTS DRY.
A WEAK COLD FRONT WILL SAG SOUTH LATE TONIGHT...AND WITH THE
INCREASED MOISTURE SOME FOG POTENTIAL WILL INCREASE ALONG WITH THE
POSSIBILITY OF LIFR FOG OR IFR CEILINGS. VERY LOW CONFIDENCE IN FOG
POTENTIAL...BUT IT SEEMS LIKE A GOOD ENOUGH CHANCE TO PUT INTO TAFS.
WILL HOLD OFF MENTIONING DENSE FOG IN A TEMPO GROUP UNTIL BETTER
CONFIDENCE DEVELOPS.
A BACK DOOR COLD FRONT WILL ZIP DOWN LAKE MICHIGAN MID THU MORNING.
WINDS WILL SHIFT TO THE NORTHEAST AND INCREASE ALONG THE LAKESHORE
WITH THE FRONT...THEN REMAIN SOMEWHAT ELEVATED AROUND 10 KNOTS
THROUGH THE MID AFTERNOON WITH THE STRONGER PRESSURE GRADIENT. THIS
COLD FRONT SCENARIO PAINTS A DREARY PICTURE FOR MILWAUKEE ON
THURSDAY. CAN/T RULE OUT DRIZZLE WITH LOW CLOUDS...GUSTY NORTHEAST
WINDS FOR A TIME AND COOL TEMPERATURES FROM THE LAKE.
&&
.MARINE...
A WEAK COLD FRONT WILL SAG IN FROM THE NORTH LATE TONIGHT THEN A
NORTHEAST FLOW AND LAKE COOLING EXPECTED ON THURSDAY. THERE IS
POTENTIAL FOR DENSE FOG TO DEVELOP ACROSS LAKE MICHIGAN TONIGHT AS
MOIST AIR WORKS ITS WAY INTO THE AREA.
&&
.CONFIDENCE...
TONIGHT AND THURSDAY...LOW.
THURSDAY NIGHT AND FRIDAY...MEDIUM.
FRIDAY NIGHT AND SATURDAY...LOW TO MEDIUM.
SATURDAY NIGHT AND SUNDAY...LOW TO MEDIUM.
MONDAY AND TUESDAY...MEDIUM.
WEDNESDAY...LOW TO MEDIUM.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
SHORT TERM/LONG TERM...MBK
VERY SHORT TERM/AVIATION/MARINE...MRC
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
113 PM CDT WED MAR 14 2012
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY THROUGH THURSDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE HIGH
PRESSURE STRETCHING FROM THE SE U.S. TO THE CENTRAL GREAT
LAKES...WHILE A COLD FRONT IS HEADING EAST OVER THE NORTHERN
PLAINS. WARMER AND MORE HUMID AIR IS SURGING NE OVER THE CENTRAL
PLAINS WHERE DEWPOINTS AND TEMPERATURES ARE IN THE 50S AND 60S FROM
WESTERN IOWA TO KANSAS. AS THIS MOISTURE FLOWS INTO THE REGION
AHEAD OF THE FRONT LATE THIS AFTERNOON INTO TONIGHT...SMALL POPS ARE
THE MAIN FORECAST CONCERN FOR THIS FORECAST.
TODAY...STRONG SHORTWAVE MOVING NE OVER CENTRAL CANADA WILL PUSH A
WEAKENING COLD FRONT ACROSS THE MISSISSIPPI VALLEY THIS MORNING AND
INTO CENTRAL WISCONSIN THIS AFTERNOON. ANTICIPATE SE WINDS THIS
MORNING TO HOLD DEWPOINTS BACK SOMEWHAT...BUT SW WINDS THIS
AFTERNOON SHOULD BRING LOW TO MID 50S DEWPOINTS FROM KANSAS AND
OKLAHOMA INTO CENTRAL AND NORTHERN WISCONSIN. THE SW WINDS WILL
ALSO BRING PLENTY OF WARM AIR NE...WITH BOTH THE ECMWF AND NAM
SHOWING 18C AT 925MB...WHICH EQUATES TO MID TO UPPER 70S FOR HIGHS
OVER CENTRAL AND E-C WISCONSIN. AS THE FRONT APPROACHES THIS
AFTERNOON...A GENEROUS 77/56 PARCEL YIELDS ABOUT 2100 J/KG OF SB
CAPE AND 42 J/KG OF CIN AT STEVENS POINT. NORMALLY WOULDNT RULE OUT
CONVECTION ALONG THE FRONT WITH THAT SMALLISH LEVEL OF CIN...BUT
MID-LEVELS ARE AWFULLY DRY AND CONVERGENCE IS PRETTY WEAK ALONG THE
FRONT. WITH NO UPPER SUPPORT (MID-LEVEL HEIGHTS ACTUALLY
INCREASE)...HAVING TROUBLE ADDING ISOLATED POPS WHEN THINK ITS GOING
TO BE DIFFICULT JUST TO GENERATE CU. IF A STORM DOES POP...AMPLE
INSTABILITY COMBINED WITH LOW WET BULB ZERO HEIGHTS OF 7500 FT AND
MID-LEVEL DRY AIR SUGGEST A HAIL/WIND THREAT WOULD BE POSSIBLE.
CONFIDENCE IS TOO LOW THOUGH TO INCLUDE ISOLATED WORDING IN THE
FORECAST.
TONIGHT...THE FRONT WILL CONTINUE TO MOVE SLOWLY ACROSS THE REST OF
CENTRAL AND NORTHEAST WISCONSIN MOSTLY DURING THE EVENING HOURS.
THE AIRMASS ALONG THE BOUNDARY WILL BECOME INCREASINGLY MORE STABLE
AS NOCTURNAL COOLING SETS IN AND THINK A THREAT OF ELEVATED
CONVECTION IS SMALL WITH THE LLJ DEVELOPING EAST OF THE REGION.
WITH CONDITIONS ONLY BECOMING INCREASINGLY MORE HOSTILE TO
CONVECTION...JUSTIFYING POPS IS A DIFFICULT SELL IF GOING WITH A DRY
FORECAST IN THE AFTERNOON. WILL KEEP AN ISOLATED MENTION THOUGH TO
BLEND WITH SURROUNDING OFFICES. STATISTICAL GUIDANCE IS RATHER
BULLISH IN PRODUCING FOG TONIGHT ACROSS THE REGION. A DRY AIRMASS
ARRIVES NORTH OF THE FRONT OVER N-C WISCONSIN SO THINK THEY ARE
RELATIVELY SAFE. BUT CLOSER TO THE BOUNDARY...WHERE LIGHTER FLOW
AND ELEVATED DEWPOINTS RESIDE...THINK THERE IS POTENTIAL FOR FOG.
WILL ADD IT TO THE FORECAST.
THURSDAY...THE SURFACE FRONT WILL DROP INTO THE SOUTHERN GREAT LAKES
ON THURSDAY...WITH WINDS SHIFTING TO THE NE BEHIND THE BOUNDARY.
SINCE THE 850MB FRONT WILL HANG FARTHER BACK OVER CENTRAL AND NE
WISCONSIN...PLENTY OF LOW LEVEL MOISTURE WILL STICK AROUND AND WILL
GO WITH PARTLY TO MOSTLY CLOUDY CONDITIONS OVER NE WISCONSIN. NOT
OUT OF THE QUESTION THAT A COUPLE SHOWERS COULD DEVELOP OVER E-C
WISCONSIN BUT WILL LET LATER SHIFTS EVALUATE BEFORE GOING OUT OF
LINE WITH SURROUNDING OFFICES. QUITE A CHALLENGING TEMPERATURE
FORECAST DUE TO THE NE WINDS OFF LAKE MICHIGAN COMBINED WITH
POTENTIAL FOR CLOUD COVER AND A WARM AIRMASS IN PLACE. HAVE DROPPED
TEMPS NEXT TO THE BAY AND LAKE THOUGH ADMIT THAT POTENTIAL IS THERE
FOR THE LAKE INFLUENCE TO PENETRATE FARTHER INLAND. TEMPS WILL
MOSTLY BE IN THE 60S AWAY FROM THE BAY AND LAKE.
.LONG TERM...THURSDAY NIGHT THRU TUESDAY. MAIN FORECAST CHALLENGES
CONTINUE TO BE HOW WARM TEMPS WILL CLIMB...AND DETERMINING BEST
CHANCE FOR SHOWERS/STORMS.
MODELS FAIRLY CONSISTENT SHOWING SW FLOW ALOFT DEVELOPING LATE
THIS WEEK...AND CONTINUING INTO EARLY NEXT WEEK. VERY MILD AIR
WILL DOMINATE THE PERIOD...WITH MORE RECORDS LIKELY TO BE BROKEN.
925-850MB TEMPS SUPPORT TEMPS IN THE UPPER 60S AND 70S ACROSS
CENTRAL AND EAST-CENTRAL WI FROM SATURDAY-TUESDAY...WITH ONLY
SLIGHTLY COOLER TEMPS ACROSS THE NORTH. SIGNIFICANTLY COOLER TEMPS
ARE EXPECTED NEAR LAKE MICHIGAN WITH A PERSISTENT ONSHORE FLOW
STARTING FRIDAY.
WEAK SHORTWAVE PASSES NORTH OF THE AREA THURSDAY NIGHT...BUT WITH
WEAK LIFT AND LIMITED MOISTURE ABOVE 925MB...WILL CONTINUE WITH A
DRY FORECAST. MODELS SHOW THE POTENTIAL FOR FOG THURSDAY NIGHT AS
WINDS DIE OFF AND DEWPOINTS REMAINING IN THE 40S. BELIEVE MODELS
ARE BEING FOOLED WITH THE VERY WARM AIRMASS IN PLACE...AS
TEMP/DEWPOINT SPREADS REMAIN ABOVE 3 DEGREES FOR MOST LOCATIONS
THROUGH THE NIGHT...LIMITING FOG POTENTIAL. SOME MET/MAV GUIDANCE
EVEN SHOWING FOG WITH SPREADS NEAR 10 DEGREES. WILL ADD SOME
PATCHY FOG ACROSS THE FOX VALLEY AND LAKESHORE...AS SE WINDS OFF
LAKE MICHIGAN COULD BRING SOME COOLER...RELATIVELY MOIST AIR
INLAND...BUT FOG CHANCES NEED TO BE MONITORED FOR THE ENTIRE AREA.
MODELS SEEM TO BE FOCUSING ON LATE SATURDAY NIGHT AND SUNDAY
FOR THE NEXT BEST CHANCE FOR SHOWERS/STORMS ACROSS THE AREA...AS A
WEAK MID-LEVEL SHORTWAVE MOVES FROM THE SOUTHERN PLAINS INTO THE
WESTERN GREAT LAKES. NO OTHER REAL SUPPORT FOR CONVECTION UNDER
THIS SYNOPTIC PATTERN...SO WILL ONLY ADD SLIGHT CHANCE POPS IN FOR
NOW AND SEE HOW THIS SYSTEM DEVELOPS. TIMING THIS TYPE OF SYSTEM
WILL BE A CHALLENGE THIS FAR OUT...SO WOULD NOT BE SURPRISED IF
ADJUSTMENTS ARE NEEDED. UPPER RIDGE BUILDS OVER THE GREAT LAKES
FOR EARLY NEXT WEEK...AS DEEP TROUGH EJECTS OUT OF THE WESTERN
CONUS INTO THE PLAINS. THE RIDGE WILL KEEP STORM CHANCES WEST OF
THE AREA THROUGH AT LEAST TUESDAY...BEFORE THE RIDGE FINALLY
BREAKS DOWN ENOUGH TO ALLOW THE TROUGH TO PROGRESS SLOWLY
EASTWARD. HOWEVER...MODELS HAVE SIGNIFICANT DIFFERENCES IN TIMING
THIS TRANSITION...WITH THE ECMWF MUCH FASTER THAN THE GFS ON
WEDNESDAY. SOMETHING TO WATCH OVER THE NEXT FEW MODEL RUNS.
&&
.AVIATION...EXPECT MAINLY VFR CONDITIONS THIS AFTERNOON...BUT
THERE IS STILL A SIGNIFICANT DEGREE OF UNCERTAINTY IN THIS
FORECAST. AS A RESULT...ENDED UP TAKING A MORE MIDDLE OF THE ROAD
APPROACH TO TAFS. MODELS INDICATED INCREASINGLY UNSTABLE AIR
ACROSS THE AREA DURING THE DAY...WITH DAYTIME HEATING AND SOUTH-
SOUTHWEST FLOW BRINGING HIGHER DEW POINTS...AND THE LAKE BREEZE
OR APPROACHING FRONT COULD CAUSE SHOWERS OR THUNDERSTORMS TO
DEVELOP. NOT A GREAT ENOUGH CHANCE OF THIS HAPPENING TO INCLUDE IN
TAFS. THERE WERE SOME MVFR CIGS IN SOUTHWEST WISCONSIN THIS
AFTERNOON BUT THIS CLOUD DECK APPEARED TO BE MOVING MORE TO THE
EAST THAN NORTHEAST. GUIDANCE WAS INDICATING PLENTIFUL LOW LEVEL
MOISTURE DURING THE NIGHT AND MOS GUIDANCE PRODUCTS HAVE MVFR/IFR
CIGS IN STRATUS AND VSBYS FORECAST BELOW A HALF MILE LATER TONIGHT
INTO THURSDAY MORNING...WITH WORST CONDITIONS AROUND GRB AND
ATW...NOT AS BAD FARTHER WEST AND NORTH.
MG
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$