Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/14/13
AREA FORECAST DISCUSSION
NWS MIAMI FL
143 PM EDT FRI APR 12 2013
.AVIATION...
SCATTERED SHOWERS HAVE DEVELOPED OVER THE INTERIOR AND LIFTING TO
THE NNE IN THE MOIST SOUTHERLY FLOW. THE RAPID REFRESH WHICH
PERFORMS VERY WELL HAS BEEN INSISTING IN THE DEVELOPMENT OF LATE
AFTERNOON TSRA OVER EASTERN PALM BEACH AND BROWARD COUNTIES SO PUT
BRIEF MVFR TEMPO GROUPS FOR THOSE TERMINALS. OTHERWISE, MOSTLY VFR
CONDITIONS SHOULD PERSIST. GUIDANCE IS INDICATING SOME LOWER
CLOUDS LATE TONIGHT BUT MAINTAINED VFR FOR NOW. SURFACE WIND WILL
REMAIN SSE ALONG THE EAST COAST THROUGH THE FORECAST OCCASIONALLY
GUSTING TO 20+ KNOTS THIS AFTERNOON ALONG WITH A GULF COAST SEA
BREEZE.
KOB
&&
.PREV DISCUSSION... /ISSUED 1008 AM EDT FRI APR 12 2013/
UPDATE...
THE MORNING SURFACE ANALYSIS SHOWED A COLD FRONT EXTENDING SOUTH
AND SOUTHWEST ACROSS THE FLORIDA BIG BEND TO THE CENTRAL GULF OF
MEXICO WITH MOIST SOUTHERLY FLOW ACROSS THE FLORIDA PENINSULA
AHEAD OF IT. LOCAL OBSERVATIONS SHOWED DEWPOINTS RANGING FROM 70
TO 75 DEGREES. THE MORNING SOUNDING HERE IN MIAMI WAS VERY MOIST
UP TO AROUND 650 MB (PWAT AT 2.03") WITH LIGHT TO MODERATE
SOUTHERLY FLOW THROUGH THE LOW/MID LAYERS. THE LATEST RADAR LOOP
SHOWED MAINLY ISOLATED/SCT SHOWERS SPREADING NORTH ALONG THE EAST
COAST OF BROWARD AND MIAMI-DADE COUNTIES. LATER IN THE
AFTERNOON/EVENING...THE PREVIOUSLY MENTIONED COLD FRONT WILL
CONTINUE TO ADVANCE EASTWARD TOWARD AND INTO CENTRAL FLORIDA. THIS
COMBINED WITH DAYTIME HEATING...PLENTY OF DEEP LAYER MOISTURE AND
THE AFTERNOON SEA BREEZES WILL BE ENOUGH TO SUPPORT SCATTERED
THUNDERSTORMS TODAY. THE BEST CHANCE FOR THESE STORMS WILL REMAIN
OVER THE NORTHERN AND EASTERN SECTIONS OF THE AREA...ESPECIALLY
OVER PALM BEACH COUNTY. THE LATEST HRRR AND WRF ARW MODEL
REFLECTIVITIES LINE UP WELL WITH THIS PATTERN AND INDICATE THE
AFTERNOON CONVECTION INITIATING AND CONCENTRATING OVER THE EAST
COAST FROM BROWARD TO PALM BEACH COUNTIES AFTER 16Z...THEN
TRENDING DOWN THROUGH MID-EVENING PERIOD. THE MAIN IMPACTS FROM
THESE STORMS WILL BE THE POTENTIAL FOR WET MICROBURSTS AND HEAVY
RAINFALL. THE EXPERIMENTAL WMSI INDEX FROM THE LOCALLY RUN WRFNMM
SB-CAPE AND SFC/MID-LEVEL THETA-E INDICATE WIND GUSTS FROM ANY
MICROBURST COULD REACH THE 35 TO 49 KT RANGE FROM ANY STRONG STORM
THAT DOES DEVELOP. FOR THE MORNING UPDATE...WE HAVE SLIGHTLY
INCREASED THE RAINFALL CHANCES TODAY OVER THESE EAST COAST
LOCATIONS MENTIONED. 85/AG
PREV DISCUSSION... /ISSUED 735 AM EDT FRI APR 12 2013/
AVIATION...
LATEST RADAR TRENDS SHOW AREAS OF DIMINISHING RAIN SHOWERS
PUSHING NORTH ACROSS INTERIOR AREAS EARLY THIS MORNING AS A MOIST
LOW LEVEL FLOW SURGES ACROSS THE AREA FROM THE GULF OF MEXICO.
SHOWERS SHOULD CONTINUE TO PUSH TO THE NORTH AND REDEVELOP THROUGH
THE EARLY MORNING HOURS ACCOMPANIED WITH GENERALLY MVFR CIGS FOR
ALL TAF SITES. CANNOT NOT RULE OUT AN ISOLATED IFR CIG FOR A BRIEF
PERIOD SOMETIME THIS MORNING ALONG WITH AN ISOLD TSRA BUT WILL
LEAVE OUT OF THE FORECAST AT THIS TIME. WINDS WILL MOSTLY REMAIN
SSE AND INCREASE THROUGH THE AFTERNOON AS A COLD FRONT APPROACHES
FROM THE NORTH. GULF SEA BREEZE WILL DEVELOP BY LATE THIS MORNING
SO THE THREAT FOR ADDITIONAL CONVECTION WILL REMAIN EAST OF THE
KAPF TERMINAL.
KOB/CD
PREV DISCUSSION... /ISSUED 540 AM EDT FRI APR 12 2013/
DISCUSSION...
CONDITION ARE BEGINNING TO CHANGE THIS MORNING IN ADVANCE OF AN
APPROACHING COLD FRONT. THIS IS THE FRONT WE HAVE BEEN EXPECTING
MOST OF THE WEEK. MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE
FRONT STALLING SOMEWHERE OVER CENTRAL FLORIDA. THIS IS DUE TO
STRONG HIGH PRESSURE TO THE EAST AND THE FACT THAT THE MAIN WILL
BE VERY QUICKLY MOVING TO THE NORTHEAST, TAKING MOST OF THE ENERGY
WITH IT. THERE IS AN AREA OF HIGH PRESSURE MOVING IN BEHIND THE
FRONT. THIS HIGH PRESSURE WILL MERGE WITH THE HIGH PRESSURE SYSTEM
TO THE EAST. AS IT DOES, IT WILL ALLOW FOR A PERIOD OF MOSTLY
QUIET WEATHER FOR NEXT WEEK. THERE WILL STILL BE A SMALL POTENTIAL
FOR AN AFTERNOON SHOWER OR AN ISOLATED THUNDERSTORM TO DEVELOP,
BUT THAT WILL BE MAINLY IN THE AFTERNOON, AND LOOKS TO DIMINISH
TOWARDS THE MIDDLE OF THE WEEK AT THIS TIME.
AS FOR THE DYNAMICS FOR TODAY AND TOMORROW. WELL, THERE IS TYPICAL
INSTABILITY IN PLACE FOR TODAY, AS WELL AS PLENTY OF MOISTURE.
MODELS ARE INDICATING SOME ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM THIS AFTERNOON. THE HRRR PLACES MOST OF
THE ACTIVITY ALONG THE EAST COAST OF SOUTH FLORIDA. GIVEN THE
SOUTHWESTERLY FLOW, CAN NOT ARGUE AGAINST IT. SO, WHILE POPS ARE
ALL OVER THE CWA, THERE ARE SOME HIGH POPS IN THE NORTHEASTERN
PORTION OF SOUTH FLORIDA.
FOR TOMORROW, THE LONG ANTICIPATED COLD FRONT WILL MOVE INTO THE
FLORIDA PENINSULA. IT CURRENTLY LOOKS TO MAKE IT DOWN JUST ABOUT TO
LAKE OKEECHOBEE BEFORE STALLING. THIS WILL KEEP SOUTH FLORIDA IN
THE WARM SECTOR TOMORROW. THERE WILL ALSO BE A 100KT JET EXITING
CENTRAL FLORIDA, WITH THE TAIL END NEAR MELBOURNE AROUND 00Z
SUNDAY. THIS PLACES THE AREA NEAR LAKE OKEECHOBEE IN THE RIGHT
ENTRANCE REGION OF THE JET. THIS, COMBINED WITH THE SFC BOUNDARY
AND PLENTY OF CAPE, AROUND 1500 JOULES, WILL PROBABLY ALLOW SOME
THUNDERSTORMS TO DEVELOP. SOME OF THOSE STORMS MAY BE STRONG.
THESE WILL MOVE OFF TO THE EAST, ALONG WITH THE UPPER LEVEL
DYNAMICS BY SATURDAY EVENING. THE FRONT WILL DISSIPATE THROUGH THE
DAY ON SUNDAY.
MARINE...
HIGH PRESSURE HAS SHIFTED SLIGHTLY AHEAD OF A COLD FRONT. THIS
WILL CAUSE THE WINDS TO TURN TO THE SW OVER THE GULF TODAY. THE
WINDS OVER THE ATLANTIC WILL TURN MORE SOUTHERLY. THE COLD FRONT
WILL MOVE CLOSER TO SOUTH FLORIDA TONIGHT AND STALL ACROSS SOUTH
CENTRAL FLORIDA BY TOMORROW MORNING. THIS WILL ALLOW SHOWERS AND
THUNDERSTORMS TO DEVELOP THROUGH TOMORROW EVENING. THE FRONT WILL
DISSIPATE THROUGH THE DAY ON SUNDAY, ALLOWING FOR QUIETER WEATHER.
FIRE WEATHER...
THE MAIN CONCERNS WILL BE WIND AND THUNDERSTORMS TODAY AND
TOMORROW. THE WIND WILL TURN FROM THE SOUTHEAST TO BE OUT OF THE
SOUTHWEST TODAY AS HIGH PRESSURE TO THE EAST HAS SHIFTED SOMEWHAT
IN ADVANCE OF A COLD FRONT. THE WINDS ARE EXPECTED TO PICK UP TO
NEAR 15 MPH THIS AFTERNOON. THERE IS A CHANCE OF A THUNDERSTORM
TODAY, MAINLY NORTH OF I75.
BY TOMORROW, THE COLD FRONT WILL STALL OVER SOUTH CENTRAL FLORIDA.
THIS WILL ALLOW THUNDERSTORM DEVELOP ACROSS THE AREA, BUT MAINLY
IN THE LAKE REGION. SOME OF THE STORMS COULD BECOME STRONG. THE
FRONT WILL DISSIPATE THROUGH SUNDAY. QUIETER WEATHER CONDITIONS ARE
EXPECTED NEXT WEEK UNDER HIGH PRESSURE.
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
1008 AM EDT FRI APR 12 2013
.UPDATE...
THE MORNING SURFACE ANALYSIS SHOWED A COLD FRONT EXTENDING SOUTH
AND SOUTHWEST ACROSS THE FLORIDA BIG BEND TO THE CENTRAL GULF OF
MEXICO WITH MOIST SOUTHERLY FLOW ACROSS THE FLORIDA PENINSULA
AHEAD OF IT. LOCAL OBSERVATIONS SHOWED DEWPOINTS RANGING FROM 70
TO 75 DEGREES. THE MORNING SOUNDING HERE IN MIAMI WAS VERY MOIST
UP TO AROUND 650 MB (PWAT AT 2.03") WITH LIGHT TO MODERATE
SOUTHERLY FLOW THROUGH THE LOW/MID LAYERS. THE LATEST RADAR LOOP
SHOWED MAINLY ISOLATED/SCT SHOWERS SPREADING NORTH ALONG THE EAST
COAST OF BROWARD AND MIAMI-DADE COUNTIES. LATER IN THE
AFTERNOON/EVENING...THE PREVIOUSLY MENTIONED COLD FRONT WILL
CONTINUE TO ADVANCE EASTWARD TOWARD AND INTO CENTRAL FLORIDA. THIS
COMBINED WITH DAYTIME HEATING...PLENTY OF DEEP LAYER MOISTURE AND
THE AFTERNOON SEA BREEZES WILL BE ENOUGH TO SUPPORT SCATTERED
THUNDERSTORMS TODAY. THE BEST CHANCE FOR THESE STORMS WILL REMAIN
OVER THE NORTHERN AND EASTERN SECTIONS OF THE AREA...ESPECIALLY
OVER PALM BEACH COUNTY. THE LATEST HRRR AND WRF ARW MODEL
REFLECTIVITIES LINE UP WELL WITH THIS PATTERN AND INDICATE THE
AFTERNOON CONVECTION INITIATING AND CONCENTRATING OVER THE EAST
COAST FROM BROWARD TO PALM BEACH COUNTIES AFTER 16Z...THEN
TRENDING DOWN THROUGH MID-EVENING PERIOD. THE MAIN IMPACTS FROM
THESE STORMS WILL BE THE POTENTIAL FOR WET MICROBURSTS AND HEAVY
RAINFALL. THE EXPERIMENTAL WMSI INDEX FROM THE LOCALLY RUN WRFNMM
SB-CAPE AND SFC/MID-LEVEL THETA-E INDICATE WIND GUSTS FROM ANY
MICROBURST COULD REACH THE 35 TO 49 KT RANGE FROM ANY STRONG STORM
THAT DOES DEVELOP. FOR THE MORNING UPDATE...WE HAVE SLIGHTLY
INCREASED THE RAINFALL CHANCES TODAY OVER THESE EAST COAST
LOCATIONS MENTIONED. 85/AG
&&
.PREV DISCUSSION... /ISSUED 735 AM EDT FRI APR 12 2013/
AVIATION...
LATEST RADAR TRENDS SHOW AREAS OF DIMINISHING RAIN SHOWERS
PUSHING NORTH ACROSS INTERIOR AREAS EARLY THIS MORNING AS A MOIST
LOW LEVEL FLOW SURGES ACROSS THE AREA FROM THE GULF OF MEXICO.
SHOWERS SHOULD CONTINUE TO PUSH TO THE NORTH AND REDEVELOP THROUGH
THE EARLY MORNING HOURS ACCOMPANIED WITH GENERALLY MVFR CIGS FOR
ALL TAF SITES. CANNOT NOT RULE OUT AN ISOLATED IFR CIG FOR A BRIEF
PERIOD SOMETIME THIS MORNING ALONG WITH AN ISOLD TSRA BUT WILL
LEAVE OUT OF THE FORECAST AT THIS TIME. WINDS WILL MOSTLY REMAIN
SSE AND INCREASE THROUGH THE AFTERNOON AS A COLD FRONT APPROACHES
FROM THE NORTH. GULF SEA BREEZE WILL DEVELOP BY LATE THIS MORNING
SO THE THREAT FOR ADDITIONAL CONVECTION WILL REMAIN EAST OF THE
KAPF TERMINAL.
KOB/CD
PREV DISCUSSION... /ISSUED 540 AM EDT FRI APR 12 2013/
DISCUSSION...
CONDITION ARE BEGINNING TO CHANGE THIS MORNING IN ADVANCE OF AN
APPROACHING COLD FRONT. THIS IS THE FRONT WE HAVE BEEN EXPECTING
MOST OF THE WEEK. MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE
FRONT STALLING SOMEWHERE OVER CENTRAL FLORIDA. THIS IS DUE TO
STRONG HIGH PRESSURE TO THE EAST AND THE FACT THAT THE MAIN WILL
BE VERY QUICKLY MOVING TO THE NORTHEAST, TAKING MOST OF THE ENERGY
WITH IT. THERE IS AN AREA OF HIGH PRESSURE MOVING IN BEHIND THE
FRONT. THIS HIGH PRESSURE WILL MERGE WITH THE HIGH PRESSURE SYSTEM
TO THE EAST. AS IT DOES, IT WILL ALLOW FOR A PERIOD OF MOSTLY
QUIET WEATHER FOR NEXT WEEK. THERE WILL STILL BE A SMALL POTENTIAL
FOR AN AFTERNOON SHOWER OR AN ISOLATED THUNDERSTORM TO DEVELOP,
BUT THAT WILL BE MAINLY IN THE AFTERNOON, AND LOOKS TO DIMINISH
TOWARDS THE MIDDLE OF THE WEEK AT THIS TIME.
AS FOR THE DYNAMICS FOR TODAY AND TOMORROW. WELL, THERE IS TYPICAL
INSTABILITY IN PLACE FOR TODAY, AS WELL AS PLENTY OF MOISTURE.
MODELS ARE INDICATING SOME ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM THIS AFTERNOON. THE HRRR PLACES MOST OF
THE ACTIVITY ALONG THE EAST COAST OF SOUTH FLORIDA. GIVEN THE
SOUTHWESTERLY FLOW, CAN NOT ARGUE AGAINST IT. SO, WHILE POPS ARE
ALL OVER THE CWA, THERE ARE SOME HIGH POPS IN THE NORTHEASTERN
PORTION OF SOUTH FLORIDA.
FOR TOMORROW, THE LONG ANTICIPATED COLD FRONT WILL MOVE INTO THE
FLORIDA PENINSULA. IT CURRENTLY LOOKS TO MAKE IT DOWN JUST ABOUT TO
LAKE OKEECHOBEE BEFORE STALLING. THIS WILL KEEP SOUTH FLORIDA IN
THE WARM SECTOR TOMORROW. THERE WILL ALSO BE A 100KT JET EXITING
CENTRAL FLORIDA, WITH THE TAIL END NEAR MELBOURNE AROUND 00Z
SUNDAY. THIS PLACES THE AREA NEAR LAKE OKEECHOBEE IN THE RIGHT
ENTRANCE REGION OF THE JET. THIS, COMBINED WITH THE SFC BOUNDARY
AND PLENTY OF CAPE, AROUND 1500 JOULES, WILL PROBABLY ALLOW SOME
THUNDERSTORMS TO DEVELOP. SOME OF THOSE STORMS MAY BE STRONG.
THESE WILL MOVE OFF TO THE EAST, ALONG WITH THE UPPER LEVEL
DYNAMICS BY SATURDAY EVENING. THE FRONT WILL DISSIPATE THROUGH THE
DAY ON SUNDAY.
MARINE...
HIGH PRESSURE HAS SHIFTED SLIGHTLY AHEAD OF A COLD FRONT. THIS
WILL CAUSE THE WINDS TO TURN TO THE SW OVER THE GULF TODAY. THE
WINDS OVER THE ATLANTIC WILL TURN MORE SOUTHERLY. THE COLD FRONT
WILL MOVE CLOSER TO SOUTH FLORIDA TONIGHT AND STALL ACROSS SOUTH
CENTRAL FLORIDA BY TOMORROW MORNING. THIS WILL ALLOW SHOWERS AND
THUNDERSTORMS TO DEVELOP THROUGH TOMORROW EVENING. THE FRONT WILL
DISSIPATE THROUGH THE DAY ON SUNDAY, ALLOWING FOR QUIETER WEATHER.
FIRE WEATHER...
THE MAIN CONCERNS WILL BE WIND AND THUNDERSTORMS TODAY AND
TOMORROW. THE WIND WILL TURN FROM THE SOUTHEAST TO BE OUT OF THE
SOUTHWEST TODAY AS HIGH PRESSURE TO THE EAST HAS SHIFTED SOMEWHAT
IN ADVANCE OF A COLD FRONT. THE WINDS ARE EXPECTED TO PICK UP TO
NEAR 15 MPH THIS AFTERNOON. THERE IS A CHANCE OF A THUNDERSTORM
TODAY, MAINLY NORTH OF I75.
BY TOMORROW, THE COLD FRONT WILL STALL OVER SOUTH CENTRAL FLORIDA.
THIS WILL ALLOW THUNDERSTORM DEVELOP ACROSS THE AREA, BUT MAINLY
IN THE LAKE REGION. SOME OF THE STORMS COULD BECOME STRONG. THE
FRONT WILL DISSIPATE THROUGH SUNDAY. QUIETER WEATHER CONDITIONS ARE
EXPECTED NEXT WEEK UNDER HIGH PRESSURE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 85 73 84 72 / 40 20 50 20
FORT LAUDERDALE 84 74 84 74 / 40 20 50 20
MIAMI 85 74 84 74 / 30 20 40 20
NAPLES 82 70 82 69 / 30 20 40 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...30/KOB
AREA FORECAST DISCUSSION
NWS MIAMI FL
735 AM EDT FRI APR 12 2013
.AVIATION...
LATEST RADAR TRENDS SHOW AREAS OF DIMINISHING RAIN SHOWERS
PUSHING NORTH ACROSS INTERIOR AREAS EARLY THIS MORNING AS A MOIST
LOW LEVEL FLOW SURGES ACROSS THE AREA FROM THE GULF OF MEXICO.
SHOWERS SHOULD CONTINUE TO PUSH TO THE NORTH AND REDEVELOP THROUGH
THE EARLY MORNING HOURS ACCOMPANIED WITH GENERALLY MVFR CIGS FOR
ALL TAF SITES. CANNOT NOT RULE OUT AN ISOLATED IFR CIG FOR A BRIEF
PERIOD SOMETIME THIS MORNING ALONG WITH AN ISOLD TSRA BUT WILL
LEAVE OUT OF THE FORECAST AT THIS TIME. WINDS WILL MOSTLY REMAIN
SSE AND INCREASE THROUGH THE AFTERNOON AS A COLD FRONT APPROACHES
FROM THE NORTH. GULF SEA BREEZE WILL DEVELOP BY LATE THIS MORNING
SO THE THREAT FOR ADDITIONAL CONVECTION WILL REMAIN EAST OF THE
KAPF TERMINAL.
KOB/CD
&&
.PREV DISCUSSION... /ISSUED 540 AM EDT FRI APR 12 2013/
DISCUSSION...
CONDITION ARE BEGINNING TO CHANGE THIS MORNING IN ADVANCE OF AN
APPROACHING COLD FRONT. THIS IS THE FRONT WE HAVE BEEN EXPECTING
MOST OF THE WEEK. MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE
FRONT STALLING SOMEWHERE OVER CENTRAL FLORIDA. THIS IS DUE TO
STRONG HIGH PRESSURE TO THE EAST AND THE FACT THAT THE MAIN WILL
BE VERY QUICKLY MOVING TO THE NORTHEAST, TAKING MOST OF THE ENERGY
WITH IT. THERE IS AN AREA OF HIGH PRESSURE MOVING IN BEHIND THE
FRONT. THIS HIGH PRESSURE WILL MERGE WITH THE HIGH PRESSURE SYSTEM
TO THE EAST. AS IT DOES, IT WILL ALLOW FOR A PERIOD OF MOSTLY
QUIET WEATHER FOR NEXT WEEK. THERE WILL STILL BE A SMALL POTENTIAL
FOR AN AFTERNOON SHOWER OR AN ISOLATED THUNDERSTORM TO DEVELOP,
BUT THAT WILL BE MAINLY IN THE AFTERNOON, AND LOOKS TO DIMINISH
TOWARDS THE MIDDLE OF THE WEEK AT THIS TIME.
AS FOR THE DYNAMICS FOR TODAY AND TOMORROW. WELL, THERE IS TYPICAL
INSTABILITY IN PLACE FOR TODAY, AS WELL AS PLENTY OF MOISTURE.
MODELS ARE INDICATING SOME ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM THIS AFTERNOON. THE HRRR PLACES MOST OF
THE ACTIVITY ALONG THE EAST COAST OF SOUTH FLORIDA. GIVEN THE
SOUTHWESTERLY FLOW, CAN NOT ARGUE AGAINST IT. SO, WHILE POPS ARE
ALL OVER THE CWA, THERE ARE SOME HIGH POPS IN THE NORTHEASTERN
PORTION OF SOUTH FLORIDA.
FOR TOMORROW, THE LONG ANTICIPATED COLD FRONT WILL MOVE INTO THE
FLORIDA PENINSULA. IT CURRENTLY LOOKS TO MAKE IT DOWN JUST ABOUT TO
LAKE OKEECHOBEE BEFORE STALLING. THIS WILL KEEP SOUTH FLORIDA IN
THE WARM SECTOR TOMORROW. THERE WILL ALSO BE A 100KT JET EXITING
CENTRAL FLORIDA, WITH THE TAIL END NEAR MELBOURNE AROUND 00Z
SUNDAY. THIS PLACES THE AREA NEAR LAKE OKEECHOBEE IN THE RIGHT
ENTRANCE REGION OF THE JET. THIS, COMBINED WITH THE SFC BOUNDARY
AND PLENTY OF CAPE, AROUND 1500 JOULES, WILL PROBABLY ALLOW SOME
THUNDERSTORMS TO DEVELOP. SOME OF THOSE STORMS MAY BE STRONG.
THESE WILL MOVE OFF TO THE EAST, ALONG WITH THE UPPER LEVEL
DYNAMICS BY SATURDAY EVENING. THE FRONT WILL DISSIPATE THROUGH THE
DAY ON SUNDAY.
MARINE...
HIGH PRESSURE HAS SHIFTED SLIGHTLY AHEAD OF A COLD FRONT. THIS
WILL CAUSE THE WINDS TO TURN TO THE SW OVER THE GULF TODAY. THE
WINDS OVER THE ATLANTIC WILL TURN MORE SOUTHERLY. THE COLD FRONT
WILL MOVE CLOSER TO SOUTH FLORIDA TONIGHT AND STALL ACROSS SOUTH
CENTRAL FLORIDA BY TOMORROW MORNING. THIS WILL ALLOW SHOWERS AND
THUNDERSTORMS TO DEVELOP THROUGH TOMORROW EVENING. THE FRONT WILL
DISSIPATE THROUGH THE DAY ON SUNDAY, ALLOWING FOR QUIETER WEATHER.
FIRE WEATHER...
THE MAIN CONCERNS WILL BE WIND AND THUNDERSTORMS TODAY AND
TOMORROW. THE WIND WILL TURN FROM THE SOUTHEAST TO BE OUT OF THE
SOUTHWEST TODAY AS HIGH PRESSURE TO THE EAST HAS SHIFTED SOMEWHAT
IN ADVANCE OF A COLD FRONT. THE WINDS ARE EXPECTED TO PICK UP TO
NEAR 15 MPH THIS AFTERNOON. THERE IS A CHANCE OF A THUNDERSTORM
TODAY, MAINLY NORTH OF I75.
BY TOMORROW, THE COLD FRONT WILL STALL OVER SOUTH CENTRAL FLORIDA.
THIS WILL ALLOW THUNDERSTORM DEVELOP ACROSS THE AREA, BUT MAINLY
IN THE LAKE REGION. SOME OF THE STORMS COULD BECOME STRONG. THE
FRONT WILL DISSIPATE THROUGH SUNDAY. QUIETER WEATHER CONDITIONS ARE
EXPECTED NEXT WEEK UNDER HIGH PRESSURE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 85 73 84 72 / 40 20 50 20
FORT LAUDERDALE 84 74 84 74 / 40 20 50 20
MIAMI 85 74 84 74 / 30 20 40 20
NAPLES 82 70 82 69 / 30 20 50 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
540 AM EDT FRI APR 12 2013
.DISCUSSION...
CONDITION ARE BEGINNING TO CHANGE THIS MORNING IN ADVANCE OF AN
APPROACHING COLD FRONT. THIS IS THE FRONT WE HAVE BEEN EXPECTING
MOST OF THE WEEK. MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE
FRONT STALLING SOMEWHERE OVER CENTRAL FLORIDA. THIS IS DUE TO
STRONG HIGH PRESSURE TO THE EAST AND THE FACT THAT THE MAIN WILL
BE VERY QUICKLY MOVING TO THE NORTHEAST, TAKING MOST OF THE ENERGY
WITH IT. THERE IS AN AREA OF HIGH PRESSURE MOVING IN BEHIND THE
FRONT. THIS HIGH PRESSURE WILL MERGE WITH THE HIGH PRESSURE SYSTEM
TO THE EAST. AS IT DOES, IT WILL ALLOW FOR A PERIOD OF MOSTLY
QUIET WEATHER FOR NEXT WEEK. THERE WILL STILL BE A SMALL POTENTIAL
FOR AN AFTERNOON SHOWER OR AN ISOLATED THUNDERSTORM TO DEVELOP,
BUT THAT WILL BE MAINLY IN THE AFTERNOON, AND LOOKS TO DIMINISH
TOWARDS THE MIDDLE OF THE WEEK AT THIS TIME.
AS FOR THE DYNAMICS FOR TODAY AND TOMORROW. WELL, THERE IS TYPICAL
INSTABILITY IN PLACE FOR TODAY, AS WELL AS PLENTY OF MOISTURE.
MODELS ARE INDICATING SOME ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM THIS AFTERNOON. THE HRRR PLACES MOST OF
THE ACTIVITY ALONG THE EAST COAST OF SOUTH FLORIDA. GIVEN THE
SOUTHWESTERLY FLOW, CAN NOT ARGUE AGAINST IT. SO, WHILE POPS ARE
ALL OVER THE CWA, THERE ARE SOME HIGH POPS IN THE NORTHEASTERN
PORTION OF SOUTH FLORIDA.
FOR TOMORROW, THE LONG ANTICIPATED COLD FRONT WILL MOVE INTO THE
FLORIDA PENINSULA. IT CURRENTLY LOOKS TO MAKE IT DOWN JUST ABOUT TO
LAKE OKEECHOBEE BEFORE STALLING. THIS WILL KEEP SOUTH FLORIDA IN
THE WARM SECTOR TOMORROW. THERE WILL ALSO BE A 100KT JET EXITING
CENTRAL FLORIDA, WITH THE TAIL END NEAR MELBOURNE AROUND 00Z
SUNDAY. THIS PLACES THE AREA NEAR LAKE OKEECHOBEE IN THE RIGHT
ENTRANCE REGION OF THE JET. THIS, COMBINED WITH THE SFC BOUNDARY
AND PLENTY OF CAPE, AROUND 1500 JOULES, WILL PROBABLY ALLOW SOME
THUNDERSTORMS TO DEVELOP. SOME OF THOSE STORMS MAY BE STRONG.
THESE WILL MOVE OFF TO THE EAST, ALONG WITH THE UPPER LEVEL
DYNAMICS BY SATURDAY EVENING. THE FRONT WILL DISSIPATE THROUGH THE
DAY ON SUNDAY.
MARINE...
HIGH PRESSURE HAS SHIFTED SLIGHTLY AHEAD OF A COLD FRONT. THIS
WILL CAUSE THE WINDS TO TURN TO THE SW OVER THE GULF TODAY. THE
WINDS OVER THE ATLANTIC WILL TURN MORE SOUTHERLY. THE COLD FRONT
WILL MOVE CLOSER TO SOUTH FLORIDA TONIGHT AND STALL ACROSS SOUTH
CENTRAL FLORIDA BY TOMORROW MORNING. THIS WILL ALLOW SHOWERS AND
THUNDERSTORMS TO DEVELOP THROUGH TOMORROW EVENING. THE FRONT WILL
DISSIPATE THROUGH THE DAY ON SUNDAY, ALLOWING FOR QUIETER WEATHER.
FIRE WEATHER...
THE MAIN CONCERNS WILL BE WIND AND THUNDERSTORMS TODAY AND
TOMORROW. THE WIND WILL TURN FROM THE SOUTHEAST TO BE OUT OF THE
SOUTHWEST TODAY AS HIGH PRESSURE TO THE EAST HAS SHIFTED SOMEWHAT
IN ADVANCE OF A COLD FRONT. THE WINDS ARE EXPECTED TO PICK UP TO
NEAR 15 MPH THIS AFTERNOON. THERE IS A CHANCE OF A THUNDERSTORM
TODAY, MAINLY NORTH OF I75.
BY TOMORROW, THE COLD FRONT WILL STALL OVER SOUTH CENTRAL FLORIDA.
THIS WILL ALLOW THUNDERSTORM DEVELOP ACROSS THE AREA, BUT MAINLY
IN THE LAKE REGION. SOME OF THE STORMS COULD BECOME STRONG. THE
FRONT WILL DISSIPATE THROUGH SUNDAY. QUIETER WEATHER CONDITIONS ARE
EXPECTED NEXT WEEK UNDER HIGH PRESSURE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 85 73 84 72 / 40 20 50 20
FORT LAUDERDALE 84 74 84 74 / 40 20 50 20
MIAMI 85 74 84 74 / 30 20 50 20
NAPLES 82 70 82 69 / 30 20 50 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...13/SI
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS MIAMI FL
531 AM EDT FRI APR 12 2013
.DISCUSSION...
CONDITION ARE BEGINNING TO CHANGE THIS MORNING IN ADVANCE OF AN
APPROACHING COLD FRONT. THIS IS THE FRONT WE HAVE BEEN EXPECTING
MOST OF THE WEEK. MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE
FRONT STALLING SOMEWHERE OVER CENTRAL FLORIDA. THIS IS DUE TO
STRONG HIGH PRESSURE TO THE EAST AND THE FACT THAT THE MAIN WILL
BE VERY QUICKLY MOVING TO THE NORTHEAST, TAKING MOST OF THE ENERGY
WITH IT. THERE IS AN AREA OF HIGH PRESSURE MOVING IN BEHIND THE
FRONT. THIS HIGH PRESSURE WILL MERGE WITH THE HIGH PRESSURE SYSTEM
TO THE EAST. AS IT DOES, IT WILL ALLOW FOR A PERIOD OF MOSTLY
QUIET WEATHER FOR NEXT WEEK. THERE WILL STILL BE A SMALL POTENTIAL
FOR AN AFTERNOON SHOWER OR AN ISOLATED THUNDERSTORM TO DEVELOP,
BUT THAT WILL BE MAINLY IN THE AFTERNOON, AND LOOKS TO DIMINISH
TOWARDS THE MIDDLE OF THE WEEK AT THIS TIME.
AS FOR THE DYNAMICS FOR TODAY AND TOMORROW. WELL, THERE IS TYPICAL
INSTABILITY IN PLACE FOR TODAY, AS WELL AS PLENTY OF MOISTURE.
MODELS ARE INDICATING SOME ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM THIS AFTERNOON. THE HRRR PLACES MOST OF
THE ACTIVITY ALONG THE EAST COAST OF SOUTH FLORIDA. GIVEN THE
SOUTHWESTERLY FLOW, CAN NOT ARGUE AGAINST IT. SO, WHILE POPS ARE
ALL OVER THE CWA, THERE ARE SOME HIGH POPS IN THE NORTHEASTERN
PORTION OF SOUTH FLORIDA.
FOR TOMORROW, THE LONG ANTICIPATED COLD FRONT WILL MOVE INTO THE
FLORIDA PENINSULA. IT CURRENTLY LOOKS TO MAKE IT DOWN JUST ABOUT TO
LAKE OKEECHOBEE BEFORE STALLING. THIS WILL KEEP SOUTH FLORIDA IN
THE WARM SECTOR TOMORROW. THERE WILL ALSO BE A 100KT JET EXITING
CENTRAL FLORIDA, WITH THE TAIL END NEAR MELBOURNE AROUND 00Z
SUNDAY. THIS PLACES THE AREA NEAR LAKE OKEECHOBEE IN THE RIGHT
ENTRANCE REGION OF THE JET. THIS, COMBINED WITH THE SFC BOUNDARY
AND PLENTY OF CAPE, AROUND 1500 JOULES, WILL PROBABLY ALLOW SOME
THUNDERSTORMS TO DEVELOP. SOME OF THOSE STORMS MAY BE STRONG.
THESE WILL MOVE OFF TO THE EAST, ALONG WITH THE UPPER LEVEL
DYNAMICS BY SATURDAY EVENING. THE FRONT WILL DISSIPATE THROUGH THE
DAY ON SUNDAY.
&&
.MARINE...
HIGH PRESSURE HAS SHIFTED SLIGHTLY AHEAD OF A COLD FRONT. THIS
WILL CAUSE THE WINDS TO TURN TO THE SW TODAY. THE COLD FRONT WILL
MOVE CLOSER TO SOUTH FLORIDA TONIGHT AND STALL ACROSS SOUTH
CENTRAL FLORIDA BY TOMORROW MORNING. THIS WILL ALLOW SHOWERS AND
THUNDERSTORMS TO DEVELOP THROUGH TOMORROW EVENING. THE FRONT WILL
DISSIPATE THROUGH THE DAY ON SUNDAY, ALLOWING FOR QUIETER WEATHER.
&&
.FIRE WEATHER...
THE MAIN CONCERNS WILL BE WIND AND THUNDERSTORMS TODAY AND
TOMORROW. THE WIND WILL TURN FROM THE SOUTHEAST TO BE OUT OF THE
SOUTHWEST TODAY AS HIGH PRESSURE TO THE EAST HAS SHIFTED SOMEWHAT
IN ADVANCE OF A COLD FRONT. THE WINDS ARE EXPECTED TO PICK UP TO
NEAR 15 MPH THIS AFTERNOON. THERE IS A CHANCE OF A THUNDERSTORM
TODAY, MAINLY NORTH OF I75.
BY TOMORROW, THE COLD FRONT WILL STALL OVER SOUTH CENTRAL FLORIDA.
THIS WILL ALLOW THUNDERSTORM DEVELOP ACROSS THE AREA, BUT MAINLY
IN THE LAKE REGION. SOME OF THE STORMS COULD BECOME STRONG. THE
FRONT WILL DISSIPATE THROUGH SUNDAY. QUIETER WEATHER CONDITIONS ARE
EXPECTED NEXT WEEK UNDER HIGH PRESSURE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 85 73 84 72 / 40 20 50 20
FORT LAUDERDALE 84 74 84 74 / 30 20 50 20
MIAMI 85 74 84 74 / 30 20 50 20
NAPLES 82 70 82 69 / 30 20 50 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...13/SI
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
746 AM EDT FRI APR 12 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION TOWARD MORNING. THE FRONT
WILL MOVE THROUGH THE AREA BY MIDDAY. HIGH PRESSURE WILL BUILD IN
BEHIND THE FRONT FOR THE WEEKEND. THERE WILL BE ANOTHER CHANCE FOR
RAIN EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD FRONT MOVING EXTENDING FROM THE UPSTATE OF SC TO CENTRAL GA
AT 11Z. NARROW BAND OF SHOWERS AHEAD OF FRONT. HIGH RESOLUTION
MODELS AND RAP SUGGEST LOW POPS THROUGH THE MORNING AS DEEPER
MOISTURE IS SHIFTING EAST AND NORTH OF THE REGION ALONG WITH
STRONGER LIFT.
FRONT APPEARS SLOW TO MOVE THROUGH THE REGION SO PREFER WARMER
GUIDANCE WITH TEMPS MAXING OUT IN THE UPPER 70S TO LOWER 80S.
DECREASING CLOUDS BY MIDDAY...BECOMING MOSTLY SUNNY AND BREEZY FOR
A PERIOD THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
COLD AIR ADVECTION AND CLEAR SKIES BEHIND THE SYSTEM TONIGHT INTO
SATURDAY MORNING WILL LEAD TO NEAR NORMAL LOWS...IN THE UPPER 40S
TO LOWER 50S. FRONT WILL BE WELL OFF THE COAST BY SATURDAY MORNING
WITH HIGH PRESSURE BUILDING IN FROM THE WEST. COOLER AND DRIER
WEATHER ON SATURDAY WITH SEASONABLE TEMPERATURES IN THE MID TO
UPPER 70S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
NO SIGNIFICANT CHANGES MADE TO THE ONGOING FORECAST FOR THIS TIME
PERIOD. HIGH PRESSURE CENTERED NORTH OF THE FORECAST AREA WILL
DOMINATE SATURDAY NIGHT INTO SUNDAY. LOW PRESSURE OVER THE GULF WILL
MOVE NORTHEAST TOWARD THE REGION LATE SUNDAY INTO MONDAY INCREASING
MOISTURE AND CLOUD COVER. KEPT CHANCE OF POPS FOR MONDAY. SYSTEM
WILL SHIFT OFF THE COAST BY LATE MONDAY WITH AN UPPER RIDGE BUILDING
INTO THE AREA THROUGH WEDNESDAY. ECMWF AND GFS DISAGREE ON TIMING
AND MAGNITUDE OF SYSTEM TOWARD THE END OF THE WEEK. GFS HAS LOW
PRESSURE SYSTEM AND ASSOCIATED STRONG COLD FRONT MOVING THROUGH
THE AREA ON THURSDAY. ECMWF SHOWS A MUCH WEAKER SYSTEM THAT IS
SLOWER TO REACH THE AREA.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
HIGH CONFIDENCE FOR MVFR THROUGH 16Z AS A COLD FRONT MOVES ACROSS
THE TAF SITES. A LINE OF SHOWERS ASSOCIATED WITH THE COLD FRONT IS
EXPECTED TO MOVE EAST OF THE TAF SITES BY 16Z.
CEILINGS WILL IMPROVE TO VFR BY MIDDAY REMAIN VFR THROUGH THE END OF
THE TAF PERIOD. LATEST GFS LAMP SHOWING A SIMILAR TREND. STRONG
PRESSURE GRADIENT WILL GIVE WAY TO WESTERLY WINDS 10-15 KTS GUSTING
TO 20-25 KTS THIS AFTERNOON. SKIES WILL CLEAR AS HIGH PRESSURE
BUILDS IN FROM THE WEST. WINDS WILL DECREASE DURING THE EVENING
HOURS AND REMAIN WEST LESS THANT 10 KTS OVERNIGHT WITH CLEAR SKIES.
EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR CIGS WITH SCATTERED
CONVECTION POSSIBLE SUNDAY NIGHT AND INTO MONDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
626 AM EDT FRI APR 12 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION TOWARD MORNING. THE FRONT
WILL MOVE THROUGH THE AREA BY MIDDAY. HIGH PRESSURE WILL BUILD IN
BEHIND THE FRONT FOR THE WEEKEND. THERE WILL BE ANOTHER CHANCE FOR
RAIN EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD FRONT MOVING INTO CENTRAL GEORGIA AT 1030Z. NARROW BAND OF
SHOWERS AHEAD OF FRONT. HIGH RESOLUTION MODELS AND RAP SUGGEST LOW
POPS THROUGH THE MORNING AS DEEPER MOISTURE IS SHIFTING EAST AND
NORTH OF THE REGION ALONG WITH STRONGER LIFT.
FRONT APPEARS SLOW TO MOVE THROUGH THE REGION SO PREFER WARMER
GUIDANCE WITH TEMPS MAXING OUT IN THE UPPER 70S TO LOWER 80S.
DECREASING CLOUDS BY MIDDAY...BECOMING MOSTLY SUNNY AND BREEZY FOR
A PERIOD THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
COLD AIR ADVECTION AND CLEAR SKIES BEHIND THE SYSTEM TONIGHT INTO
SATURDAY MORNING WILL LEAD TO NEAR NORMAL LOWS...IN THE UPPER 40S
TO LOWER 50S. FRONT WILL BE WELL OFF THE COAST BY SATURDAY MORNING
WITH HIGH PRESSURE BUILDING IN FROM THE WEST. COOLER AND DRIER
WEATHER ON SATURDAY WITH SEASONABLE TEMPERATURES IN THE MID TO
UPPER 70S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
NO SIGNIFICANT CHANGES MADE TO THE ONGOING FORECAST FOR THIS TIME
PERIOD. HIGH PRESSURE CENTERED NORTH OF THE FORECAST AREA WILL
DOMINATE SATURDAY NIGHT INTO SUNDAY. LOW PRESSURE OVER THE GULF WILL
MOVE NORTHEAST TOWARD THE REGION LATE SUNDAY INTO MONDAY INCREASING
MOISTURE AND CLOUD COVER. KEPT CHANCE OF POPS FOR MONDAY. SYSTEM
WILL SHIFT OFF THE COAST BY LATE MONDAY WITH AN UPPER RIDGE BUILDING
INTO THE AREA THROUGH WEDNESDAY. ECMWF AND GFS DISAGREE ON TIMING
AND MAGNITUDE OF SYSTEM TOWARD THE END OF THE WEEK. GFS HAS LOW
PRESSURE SYSTEM AND ASSOCIATED STRONG COLD FRONT MOVING THROUGH
THE AREA ON THURSDAY. ECMWF SHOWS A MUCH WEAKER SYSTEM THAT IS
SLOWER TO REACH THE AREA.
&&
.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
MVFR/IFR POSSIBLE AS SHOWER ACTIVITY MOVES OUT OF THE AREA..THEN VFR
THROUGH THE END OF THE PERIOD.
STILL SEEING A FEW SCATTERED RAIN SHOWERS IN THE NORTHERN PART OF
THE AREA...AND A LINE OF CONVECTIVE SHOWERS ALONG THE COLD FRONT TO
OUR WEST. OBSERVATIONS SHOW CEILINGS FLUCTUATING BETWEEN
VFR/MVFR/IFR. EXPECT SHOWER ACTIVITY WILL END AS THE FRONT MOVES
THROUGH THE AREA. CEILINGS WILL IMPROVE TO VFR BY LATE MORNING AND
REMAIN VFR THROUGH THE END OF THE TAF PERIOD. LATEST GFS LAMP
SHOWING A SIMILAR TREND. STRONG PRESSURE GRADIENT WILL GIVE WAY TO
SOUTHWESTERLY WINDS 10-15 KTS GUSTING TO 20-25 KTS FRIDAY AFTERNOON.
SKIES WILL CLEAR AS HIGH PRESSURE BUILDS IN FROM THE WEST AND THE
COLD FRONT SHIFTS EAST OF THE AREA TOWARD THE COAST. WINDS WILL
DECREASE DURING THE EVENING HOURS AND REMAIN WEST AROUND 5-7 KTS
OVERNIGHT WITH CLEAR SKIES.
EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR CIGS WITH SCATTERED
CONVECTION POSSIBLE SUNDAY NIGHT AND INTO MONDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1158 AM EDT FRI APR 12 2013
.UPDATE...
ISSUED AT 1157 AM EDT FRI APR 12 2013
BEHIND THE DEPARTING LOW PRESSURE SYSTEM...AN UPPER LEVEL DISTURBANCE
WILL ROTATE THROUGH THE OH VALLEY TODAY AND THIS COMBINED WITH SOME
LOW LEVEL MOISTURE FROM RECENT PRECIPITATION SHOULD RESULT IN SOME
CU THIS AFTERNOON. THE CU SHOULD BE MOST WIDESPREAD ACROSS THE NORTH
AND NOT AS MUCH COVERAGE CLOSER TO THE VA BORDER.
TEMPS AND DEWPOINTS WERE FRESHENED UP BASED ON RECENT OBSERVATIONS
AND WINDS WERE INCREASED A BIT...ESPECIALLY ACROSS THE SOUTH. WITH
THE UPDATED ZFP...MORNING WORDING WAS CLEANED UP.
UPDATE ISSUED AT 655 AM EDT FRI APR 12 2013
COLD FRONT IS JUST ABOUT TO PUSH EAST OF PIKE COUNTY WITH ALL OF THE
AREA NOW SEEING TEMPERATURES FALL FAIRLY QUICKLY ALONG WITH
DEWPOINTS. SOME MID 40 TEMPERATURES ALREADY SHOWING UP ACROSS MUCH OF
CENTRAL KENTUCKY. SOME DRIZZLE HAS PERSISTED BEHIND THE DEPARTING
FRONT WITH JUST ENOUGH LOW LEVEL MOISTURE TRAPPED BELOW THE LOW LEVEL
INVERSION. THIS DRIZZLE SHOULD BE SHORT LIVED THIS MORNING AS
CEILINGS INCREASE BY MID MORNING. RUC NOW SHOWS CLOUDS HANGING ON FOR
MOST OF THE DAY...WHILE THE NAM CONTINUES TO SHOW LOW CLOUDS
DISSOLVING. GIVEN LATEST SATELLITE TRENDS...OUR WESTERN COUNTIES MAY
BE CLEARING OUT SHORTLY. GIVEN THE WIND FLOW IS NOT FAVORABLE FOR LOW
CLOUDS HANGING IN TODAY...HAVE OPTED TO GO WITH A BIT FASTER CLEARING
HAVING SKIES GO MOSTLY SUNNY BY THIS AFTERNOON. LOW CLOUDS CAN
SOMETIMES BE TRICKY AND NAM DOES SHOW MORE CLOUDS MOVING IN LATER THIS
AFTERNOON. HOWEVER...AS OF RIGHT NOW...NOT MUCH UPSTREAM...SO OPTING
TO GO A LITTLE MORE OPTIMISTIC.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 308 AM EDT FRI APR 12 2013
COLD FRONT HAS REACHED THE I-75 CORRIDOR IN THE LAST HOUR AND WILL
CONTINUE TO PUSH EAST ACROSS THE AREA EARLY THIS MORNING...CLEARING
FAR EASTERN KENTUCKY AROUND DAYBREAK. COOLER AND DRIER AIR WILL
FILTER INTO THE AREA TODAY. WITH COLD ADVECTION DURING THE MORNING
HOURS...A SMALL CLIMB FROM MORNING LOWS IS ANTICIPATED. CLOUDS WILL
LIKELY HOLD ON LONGER THAN THE NAM SUGGEST...AND CLOSER TO THE RUC
SOLUTION. THIS HAS CLOUDS EVENTUALLY BREAKING UP BY EARLY AFTERNOON.
THIS WILL ALSO IMPACT THE TEMPERATURE CLIMB TODAY. WE SHOULD BE ABLE
TO AT LEAST REACH THE MID/UPPER 50S...WITH AREAS IN THE SOUTHWEST
POSSIBLY EXCEEDING 60 WITH MORE CLEARING.
HIGH PRESSURE WILL BUILD ACROSS THE AREA TONIGHT INTO TOMORROW WITH
SKIES GOING MOSTLY CLEAR. SHELTERED VALLEYS MAY DECOUPLE TONIGHT
LEADING TO READINGS AT LEAST INTO THE MID 30S. THIS SHOULD ALLOW FOR
SOME LIMITED FROST POTENTIAL TONIGHT. A QUIET SATURDAY IS ON TAP WITH
PLENTY OF SUNSHINE BOOSTING TEMPERATURES INTO THE 60S.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 308 AM EDT FRI APR 12 2013
THE MODELS HAVE COME INTO BETTER AGREEMENT ALOFT THROUGH THE BREADTH
OF THE EXTENDED PORTION OF THE FORECAST. THEY ALL STILL TAKE THE
GREAT LAKES TROUGH EAST EARLY IN THE PERIOD ALLOWING FOR RISING
HEIGHTS OVER KENTUCKY THIS WEEKEND AND INTO THE FIRST PART OF NEXT
WEEK. THEY ALSO ALL HAVE VARIOUS REPRESENTATIONS OF A MINOR TROUGH
PASSING THROUGH THE SOUTHEAST PORTION OF THE NATION DURING THE LATTER
PART OF THE WEEKEND. THIS UNCONSOLIDATED WAVE MAY YET HAVE A
SENSIBLE IMPACT ON THE WEATHER OF EAST KENTUCKY INTO MONDAY MORNING
WITH THE NAM12 THE MOST BEARISH AND THE GFS/GEM RATHER BENIGN.
MEANWHILE...A MODERATELY STRONG CLOSED LOW WILL BE LIFTING NORTHEAST
THROUGH THE NORTHERN PLAINS WELL AWAY FROM OUR AREA. TO THE WEST OF
THIS...A DEEPENING NODE OF THE BROAD NORTHWESTERN TROUGH WILL DEVELOP
INTO A POTENT TROUGH IN ITS OWN RIGHT AND SLOWLY START TO COME EAST.
AS THIS FEATURE STRENGTHENS AND DROPS TOWARD THE FOUR CORNERS REGION
IT WILL HELP TO PUMP UP THE DOWNSTREAM RIDGE OVER THE SOUTHEAST
PORTION OF THE NATION INTO MIDWEEK. THE ECMWF AND GFS ARE IN REAL
GOOD AGREEMENT NOW WITH THE LATTER PORTION OF THE EXTENDED WHILE THE
GEM IS QUICKER AND FURTHER NORTH WITH ITS TROUGH. THIS TROUGH MOVES
INTO THE CENTRAL PLAINS ON THURSDAY WITH HEIGHT FALLS INBOUND FOR
KENTUCKY. GIVEN THE AGREEMENT OF THE PREFERRED MODELS WITH THIS WILL
FAVOR A BLENDED SOLUTION THROUGH THE EXTENDED.
SENSIBLE WEATHER WILL FEATURE A DRY AND COOL START TO THE WEEKEND
WITH PATCHY FROST POSSIBLE IN THE DEEPER VALLEYS OF EAST KENTUCKY
SUNDAY MORNING. HOWEVER...MODERATING HIGH PRESSURE MOVING OFF TO THE
EAST AND A RIDGE BUILDING ALOFT WILL ALLOW FOR A SOLID WARM UP TO
COMMENCE AND CONTINUE INTO MID WEEK. A WEAK SFC WAVE PASSING TO THE
SOUTH OF EAST KENTUCKY LATE SUNDAY NIGHT AND EARLY MONDAY MAY
TRIGGER SOME CONVECTION OVER SOUTHERN PARTS OF THE CWA. ONCE THIS
PASSES...EAST KENTUCKY WILL BE ON THE NORTHWEST FRINGE OF A LARGE
AREA OF HIGH PRESSURE ALLOWING FOR RETURN FLOW MOISTURE TO INVADE
FROM A RELATIVELY OPEN GULF OF MEXICO. THIS MOISTURE WILL SLOWLY
BUILD THROUGH THE WEEK IN THIS EARLY SUMMER-LIKE PATTERN AND RESULT
IN A DAILY CHANCE FOR MAINLY AFTERNOON AND EVENING SHOWERS OR
THUNDERSTORMS THROUGH WEDNESDAY. A BETTER CHANCE OF RAIN CAN BE
ANTICIPATED ON THURSDAY AS A DEEP AREA OF LOW PRESSURE LIFTS OUT OF
THE CENTRAL PLAINS AND MOVES TO THE NORTHERN GREAT LAKES. THIS WILL
DRAG A COLD FRONT INTO KENTUCKY HELPING TO FOCUS THE BUILT UP
MOISTURE. WITH THE BETTER CHANCES OF RAIN THURSDAY WILL LIKELY BREAK
THE TREND OF CLIMBING HIGHS FROM DAY TO DAY.
THE CR GRID LOAD CAME IN PRETTY DECENT...BUT DID NUDGE DOWN POPS ON
MONDAY GIVEN THE UNCERTAINTY AND ALSO FINE TUNED THEM LATER IN THE
EXTENDED MORE TOWARD THE 12Z ECMWF. ALSO MAKE SOME SIGNIFICANT
TERRAIN BASED ADJUSTMENTS FOR LOWS EACH NIGHT...ANTICIPATING DECENT
RIDGE TO VALLEY SPLITS THROUGHOUT THE EXTENDED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 655 AM EDT FRI APR 12 2013
CEILINGS WILL IMPROVE THROUGH THE MORNING AS DRIER AIR SPREADS ACROSS
THE AREA IN THE WAKE OF A COLD FRONT. STILL SOME UNCERTAINTY
REGARDING CLOUD COVER LATER THIS AFTERNOON AND EVENING...BUT AS OF
RIGHT NOW...NOT MUCH UPSTREAM TO HANG ANY CONFIDENCE ON THIS CLOUD
COVER. WILL GO MORE OPTIMISTIC WITH THE FORECAST FOR NOW. ANY CLOUDS
THIS AFTERNOON SHOULD REMAIN REMAIN AT OR ABOVE 5KFT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...KAS
LONG TERM...GREIF
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
655 AM EDT FRI APR 12 2013
.UPDATE...
ISSUED AT 655 AM EDT FRI APR 12 2013
COLD FRONT IS JUST ABOUT TO PUSH EAST OF PIKE COUNTY WITH ALL OF THE
AREA NOW SEEING TEMPERATURES FALL FAIRLY QUICKLY ALONG WITH
DEWPOINTS. SOME MID 40 TEMPERATURES ALREADY SHOWING UP ACROSS MUCH OF
CENTRAL KENTUCKY. SOME DRIZZLE HAS PERSISTED BEHIND THE DEPARTING
FRONT WITH JUST ENOUGH LOW LEVEL MOISTURE TRAPPED BELOW THE LOW LEVEL
INVERSION. THIS DRIZZLE SHOULD BE SHORT LIVED THIS MORNING AS
CEILINGS INCREASE BY MID MORNING. RUC NOW SHOWS CLOUDS HANGING ON FOR
MOST OF THE DAY...WHILE THE NAM CONTINUES TO SHOW LOW CLOUDS
DISSOLVING. GIVEN LATEST SATELLITE TRENDS...OUR WESTERN COUNTIES MAY
BE CLEARING OUT SHORTLY. GIVEN THE WIND FLOW IS NOT FAVORABLE FOR LOW
CLOUDS HANGING IN TODAY...HAVE OPTED TO GO WITH A BIT FASTER CLEARING
HAVING SKIES GO MOSTLY SUNNY BY THIS AFTERNOON. LOW CLOUDS CAN
SOMETIMES BE TRICKY AND NAM DOES SHOW MORE CLOUDS MOVING IN LATER THIS
AFTERNOON. HOWEVER...AS OF RIGHT NOW...NOT MUCH UPSTREAM...SO OPTING
TO GO A LITTLE MORE OPTIMISTIC.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 308 AM EDT FRI APR 12 2013
COLD FRONT HAS REACHED THE I-75 CORRIDOR IN THE LAST HOUR AND WILL
CONTINUE TO PUSH EAST ACROSS THE AREA EARLY THIS MORNING...CLEARING
FAR EASTERN KENTUCKY AROUND DAYBREAK. COOLER AND DRIER AIR WILL
FILTER INTO THE AREA TODAY. WITH COLD ADVECTION DURING THE MORNING
HOURS...A SMALL CLIMB FROM MORNING LOWS IS ANTICIPATED. CLOUDS WILL
LIKELY HOLD ON LONGER THAN THE NAM SUGGEST...AND CLOSER TO THE RUC
SOLUTION. THIS HAS CLOUDS EVENTUALLY BREAKING UP BY EARLY AFTERNOON.
THIS WILL ALSO IMPACT THE TEMPERATURE CLIMB TODAY. WE SHOULD BE ABLE
TO AT LEAST REACH THE MID/UPPER 50S...WITH AREAS IN THE SOUTHWEST
POSSIBLY EXCEEDING 60 WITH MORE CLEARING.
HIGH PRESSURE WILL BUILD ACROSS THE AREA TONIGHT INTO TOMORROW WITH
SKIES GOING MOSTLY CLEAR. SHELTERED VALLEYS MAY DECOUPLE TONIGHT
LEADING TO READINGS AT LEAST INTO THE MID 30S. THIS SHOULD ALLOW FOR
SOME LIMITED FROST POTENTIAL TONIGHT. A QUIET SATURDAY IS ON TAP WITH
PLENTY OF SUNSHINE BOOSTING TEMPERATURES INTO THE 60S.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 308 AM EDT FRI APR 12 2013
THE MODELS HAVE COME INTO BETTER AGREEMENT ALOFT THROUGH THE BREADTH
OF THE EXTENDED PORTION OF THE FORECAST. THEY ALL STILL TAKE THE
GREAT LAKES TROUGH EAST EARLY IN THE PERIOD ALLOWING FOR RISING
HEIGHTS OVER KENTUCKY THIS WEEKEND AND INTO THE FIRST PART OF NEXT
WEEK. THEY ALSO ALL HAVE VARIOUS REPRESENTATIONS OF A MINOR TROUGH
PASSING THROUGH THE SOUTHEAST PORTION OF THE NATION DURING THE LATTER
PART OF THE WEEKEND. THIS UNCONSOLIDATED WAVE MAY YET HAVE A
SENSIBLE IMPACT ON THE WEATHER OF EAST KENTUCKY INTO MONDAY MORNING
WITH THE NAM12 THE MOST BEARISH AND THE GFS/GEM RATHER BENIGN.
MEANWHILE...A MODERATELY STRONG CLOSED LOW WILL BE LIFTING NORTHEAST
THROUGH THE NORTHERN PLAINS WELL AWAY FROM OUR AREA. TO THE WEST OF
THIS...A DEEPENING NODE OF THE BROAD NORTHWESTERN TROUGH WILL DEVELOP
INTO A POTENT TROUGH IN ITS OWN RIGHT AND SLOWLY START TO COME EAST.
AS THIS FEATURE STRENGTHENS AND DROPS TOWARD THE FOUR CORNERS REGION
IT WILL HELP TO PUMP UP THE DOWNSTREAM RIDGE OVER THE SOUTHEAST
PORTION OF THE NATION INTO MIDWEEK. THE ECMWF AND GFS ARE IN REAL
GOOD AGREEMENT NOW WITH THE LATTER PORTION OF THE EXTENDED WHILE THE
GEM IS QUICKER AND FURTHER NORTH WITH ITS TROUGH. THIS TROUGH MOVES
INTO THE CENTRAL PLAINS ON THURSDAY WITH HEIGHT FALLS INBOUND FOR
KENTUCKY. GIVEN THE AGREEMENT OF THE PREFERRED MODELS WITH THIS WILL
FAVOR A BLENDED SOLUTION THROUGH THE EXTENDED.
SENSIBLE WEATHER WILL FEATURE A DRY AND COOL START TO THE WEEKEND
WITH PATCHY FROST POSSIBLE IN THE DEEPER VALLEYS OF EAST KENTUCKY
SUNDAY MORNING. HOWEVER...MODERATING HIGH PRESSURE MOVING OFF TO THE
EAST AND A RIDGE BUILDING ALOFT WILL ALLOW FOR A SOLID WARM UP TO
COMMENCE AND CONTINUE INTO MID WEEK. A WEAK SFC WAVE PASSING TO THE
SOUTH OF EAST KENTUCKY LATE SUNDAY NIGHT AND EARLY MONDAY MAY
TRIGGER SOME CONVECTION OVER SOUTHERN PARTS OF THE CWA. ONCE THIS
PASSES...EAST KENTUCKY WILL BE ON THE NORTHWEST FRINGE OF A LARGE
AREA OF HIGH PRESSURE ALLOWING FOR RETURN FLOW MOISTURE TO INVADE
FROM A RELATIVELY OPEN GULF OF MEXICO. THIS MOISTURE WILL SLOWLY
BUILD THROUGH THE WEEK IN THIS EARLY SUMMER-LIKE PATTERN AND RESULT
IN A DAILY CHANCE FOR MAINLY AFTERNOON AND EVENING SHOWERS OR
THUNDERSTORMS THROUGH WEDNESDAY. A BETTER CHANCE OF RAIN CAN BE
ANTICIPATED ON THURSDAY AS A DEEP AREA OF LOW PRESSURE LIFTS OUT OF
THE CENTRAL PLAINS AND MOVES TO THE NORTHERN GREAT LAKES. THIS WILL
DRAG A COLD FRONT INTO KENTUCKY HELPING TO FOCUS THE BUILT UP
MOISTURE. WITH THE BETTER CHANCES OF RAIN THURSDAY WILL LIKELY BREAK
THE TREND OF CLIMBING HIGHS FROM DAY TO DAY.
THE CR GRID LOAD CAME IN PRETTY DECENT...BUT DID NUDGE DOWN POPS ON
MONDAY GIVEN THE UNCERTAINTY AND ALSO FINE TUNED THEM LATER IN THE
EXTENDED MORE TOWARD THE 12Z ECMWF. ALSO MAKE SOME SIGNIFICANT
TERRAIN BASED ADJUSTMENTS FOR LOWS EACH NIGHT...ANTICIPATING DECENT
RIDGE TO VALLEY SPLITS THROUGHOUT THE EXTENDED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 655 AM EDT FRI APR 12 2013
CEILINGS WILL IMPROVE THROUGH THE MORNING AS DRIER AIR SPREADS ACROSS
THE AREA IN THE WAKE OF A COLD FRONT. STILL SOME UNCERTAINTY
REGARDING CLOUD COVER LATER THIS AFTERNOON AND EVENING...BUT AS OF
RIGHT NOW...NOT MUCH UPSTREAM TO HANG ANY CONFIDENCE ON THIS CLOUD
COVER. WILL GO MORE OPTIMISTIC WITH THE FORECAST FOR NOW. ANY CLOUDS
THIS AFTERNOON SHOULD REMAIN REMAIN AT OR ABOVE 5KFT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...KAS
LONG TERM...GREIF
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1013 AM EDT FRI APR 12 2013
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TODAY WITH SHOWERS...FOLLOWED
BY MUCH COOLER TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
WITH 1015AM UPDATE...PRIMARY CHANGES HAVE BEEN TO POPS. SHOWERS
ARE MOVING OUT VERY QUICKLY...AND UPDATED TRENDS TO END RAIN
FASTER THAN THE PREVIOUS FORECAST. USED LATEST RUNS OF THE HRRR
AND RUC TO UPDATE HOURLY TEMPERATURES AS WELL. WIND SHIFT IS
EXPECTED AS COLD FRONT COMPLETES ITS PASSAGE ACROSS THE REGION.
TEMPERATURES WILL BE MAINLY STEADY THIS MORNING AND MAY FALL A BIT
BEHIND FROPA THIS AFTERNOON BUT MAIN COLD ADVECTION AT 850MB IS
WELL BEHIND FRONT SO ONLY A BIT OF RECOVERY LATE DAY WHEN A FEW
BREAKS IN CLOUDS MAY HELP MAX TEMPS.
STILL A FEW SHOWERS IN COLD ADVECTION AND NORTHWEST FLOW TONIGHT
MAINLY WELL NORTH AND IN RIDGES.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
MAIN UPPER TROUGH AND SECONDARY PUSH OF COLDER AIR ALOFT WILL
BRING COOLER TEMPERATURES AND A CHANCE FOR SHOWERS SATURDAY MAINLY
FOR LAKE AND TERRAIN ENHANCED AREAS. SURFACE RIDGE WILL BUILD
ACROSS REGION SATURDAY EVENING TO BRING RELATIVELY DRY CONDITIONS.
AS LOW PRESSURE OVER ONTARIO MOVES OFF TO THE NORTHEAST...CANNOT
RULE OUT A STRAY SHOWER OR SNOWFLAKE NORTH OF INTERSTATE 80 SATURDAY
NIGHT. WITH CLEARING SKIES AS HIGH PRESSURE MOVES IN...EXPECT THAT
MOST LOCATIONS WILL DROP TO AROUND THE FREEZING MARK SUNDAY
MORNING. HIGH PRESSURE WILL MOVE OFF THE EAST COAST SUNDAY...BUT
TEMPERATURES SHOULD MOVE BACK TOWARDS CLIMATOLOGY...RISING INTO
THE 50S WITH LOWER 60S EASTERN OHIO.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AT THIS POINT...IT APPEARS THAT NEXT WEEKS WEATHER WILL BE
DOMINATED BY A SLOW MOVING FRONT...SIMILAR TO HOW THE PATTERN HAS
GONE THIS WEEK. A WARM FRONT SHOULD LIFT FROM SOUTH TO NORTH
ACROSS THE REGION SUNDAY NIGHT...BUT NO MODELS ARE SHOWING ANY
PRECIPITATION WITH THE FRONT. COLD FRONT WILL THEN SLIP SOUTH
ACROSS MICHIGAN AND LAKE ERIE TOWARDS OHIO. GFS AND ITS ENSEMBLE
SEEM TO BE FASTER THAN ALL OTHER MODELS BRINGING THE ASSOCIATED
PRECIP INTO EASTERN OH/WESTERN PA ON MONDAY...KEPT A SLIGHT CHANCE
LATE DAY. HIGHER CHANCE POPS ARRIVING MONDAY NIGHT. FRONT WILL BE
IN THE AREA TUESDAY INTO TUESDAY NIGHT...AND HAVE BUMPED UP POPS.
ENSEMBLES AND DETERMINISTIC MODELS THEN SHOW LOW PRESSURE MOVING
ACROSS MICHIGAN INTO ONTARIO...DRAGGING A COLD FRONT THROUGH THE
REGION WEDNESDAY INTO THURSDAY. IF THE FRONT TAKES THIS LONG TO
MOVE THROUGH...THERE COULD BE A EXTENDED PERIOD OF RAINFALL.
TEMPERATURES THROUGHOUT THE WEEK WILL BE ABOUT 10 DEGREES ABOVE
NORMAL.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
BEHIND THE RAIN SHIELD...CIGS WILL DROP AND REMAIN IN THE MVFR
CAT INTO EARLY AFTERNOON. IMPROVEMENT IN CONDITIONS FROM WEST TO
EAST DURING THE LATE MORNING/EARLY AFT HOURS. LATEST MODEL DATA IS
PORTRAYING AN IMPROVEMENT TO VFR CIGS AT ALL PORTS EXCEPT FKL AND
DUJ WHICH WILL REMAIN IN MVFR CIGS.
SFC WINDS WILL INCREASE AND VEER BEHIND FRONT WITH WESTERLY WINDS OF
10 TO 15 MPH WITH GUSTS TO 25.
.OUTLOOK.../SATURDAY THROUGH TUESDAY/...
CIG RESTRICTIONS WILL REMAIN POSSIBLE IN CAA SATURDAY. AN
IMPROVEMENT TO VFR SATURDAY NIGHT THROUGH SUNDAY NIGHT AS HIGH
PRESSURE RIDGE BRIEFLY ENTERS THE REGION. A WEAK FRONT COULD BRING
SOME SCATTERED SHOWERS MONDAY INTO TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
742 PM EDT SAT APR 13 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 415 PM EDT SAT APR 13 2013
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOWS CLOSED LO
CENTERED OVER ONTARIO TO THE S OF PERSISTENT BLOCKING RDG OVER NE
CANADA IN PREVAILING NEGATIVE NAO PATTERN. WITH DEEP MSTR SHOWN ON
12Z INL/GRB RAOBS...CYC FLOW...H85-7 COLD POCKET WITH H85 TEMPS AS
LO AS -10C TO -12C OVER THE WRN CWA...AND SHRTWVS ROTATING ARND THE
MAIN CLOSED LO...CLDS AND SHSN HAVE LINGERED OVER UPR MI...E
SPECIALLY ALONG SFC LO PRES TROF ASSOCIATED WITH ONE OF THESE
SHRTWVS THAT IS CROSSING THE CWA EARLY THIS AFTN. TEMPS REMAIN WELL
BLO NORMAL FOR MID APRIL. OVER FAR WRN MN INTO THE NRN PLAINS...A
SFC RDG AXIS AND DRY MID LVL AIR SHOWN ON THE 12Z BISMARCK RAOB ARE
CAUSING DRY WX EVEN THOUGH SOME LO CLDS LINGER WITH MSTR TRAPPED BLO
INVRN BASE AT H8 SHOWN ON THE BISMARCK SOUNDING. ANOTHER POWERFUL
SHRTWV IS MOVING ONSHORE INTO THE PAC NW WITH 00Z-12Z H3-5 HGT FALLS
UP TO 150-200M.
MAIN FCST CONCERNS THRU TNGT ARE FOCUSED ON SHSN/CLD TRENDS AS THE
UPR LO OVER ONTARIO SLOWLY FILLS AND SHIFTS TO THE E. FOCUS ON
SUN/SUN NGT SHIFTS TO TIMING AND IMPACT OF SHRTWV NOW MOVING INTO
THE PAC NW.
LATE TODAY/TNGT...AS UPR LO IN ONTARIO SLOWLY WEAKENS...H5 HGT IS
PROGGED TO RISE 120M OVER UPR MI BTWN 00Z-12Z SUN UNDER VIGOROUS
DEEP LYR QVECTOR DVGC. AS THE CYC NW FLOW WEAKENS...EXPECT LINGERING
SHSN LATE THIS AFTN/EVNG TO DIMINISH STEADILY THRU THE NGT AND END
IN THE EARLY MRNG HRS ON SUN. WITH SOME CLRG LATE AT LEAST OVER THE
W AND CENTRL AND LGT WINDS UNDER THE SFC RDG AXIS...EXPECT TEMPS TO
FALL INTO THE TEENS...WELL BLO NORMAL FOR THE SEASON. WITH CLDS/LLVL
MSTR LINGERING LONGER IN A PERSISTENT NW FLOW OVER THE E...THOSE
AREAS WL BE WARMER.
SUN/SUN NGT...EXPECT A DRY START TO THE DAY WITH SFC HI PRES RDG
SLOWLY DEPARTING TO THE E. BUT ANY MRNG SUNSHINE WL QUICKLY FADE
BEHIND INCRSG CLDS AS VIGOROUS ISENTROPIC ASCENT/DEEPER MSTR/SW FLOW
ALF BTWN THE DEPARTING HI AND INCRSG NEGATIVELY TILTED SHRTWV/SFC LO
MOVING THRU THE NRN PLAINS AND TOWARD MN LATE IN THE DAY OVERSPREADS
UPR MI. AS UPR DVGC/BAND OF H85-7 FGEN AHEAD OF ATTENDANT WARM FNT
MOVES IN AFT 18Z...EXPECT PCPN TO OVERSPREAD THE CWA BY 00Z MON...
ESPECIALLY OVER THE W HALF CLOSER TO SHARPER DYNAMICS AND WHERE
MOISTENING/H85 MSTR CNVGC IS MOST IMPRESSIVE. PTYPE WL BE A CONCERN
SUN AFTN/EVNG. NAM/GFS FCST SDNGS INDICATE SATURATED TEMP PROFILE WL
AT LEAST INITIALLY BE COMPLETELY SUB ZERO...BUT THEN SHOW ELEVATED
WARM LYR ABV SUB ZERO NEAR SFC LYR. WITH ELEVATED WARMING INITIALLY
LIFTING TEMPS ABV 0C IN THE H8-75 LYR...SUSPECT SLEET WL MIX WITH
THE SN. THESE FCST SDNGS ALSO SUG PCPN MAY BE AT LEAST MIXED WITH
SOME FZRA FOR A TIME LATE IN THE AFTN/EVNG OVER AT LEAST THE HIER
TERRAIN OF THE W HALF AS THE ELEVATED WARM LYR DEEPENS AND TEMPS IN
THE LOWER LYR WARM TOO MUCH FOR DROPS TO REFREEZE. BUT THESE SDNGS
ALSO APPEAR TO UNDERDO THE SFC WARMING IN THE AFTN FOLLOWING AT
LEAST SOME MRNG SUNSHINE. WITH SOME LINGERING LLVL DRY AIR...
EVAPORATIVE COOLING COULD MAINTAIN SUB 32 NEAR SFC WBLB TEMPS. BUT
THE FCST NEAR SFC SE FLOW IN THE ABSENCE OF HI PRES CENTER OVER
ONTARIO AS WELL AS ARRIVAL OF PCPN AT MAX HEATING TIME THIS LATE IN
THE SEASON WOULD ALSO TEND TO MINIMIZE THIS THREAT. HIER GFS MOS
TEMPS SEEM MORE APPROPRIATE FOR THE TEMPS FCST THAN RAW MODEL
GUIDANCE. FOR NOW...WL FCST A SN/SLEET MIX AT THE ONSET
TRANSITIONING TO RA SUN EVNG AS MUCH WARMER/MSTR LLVL AIR SURGES
INTO THE UPR LKS ON THE HEELS OF H85 SW WINDS FCST UP TO 60-70KTS BY
06Z MON. EXPECT LITTLE IF ANY FALL OF TEMPS SUN NGT. THE NW CWA WL
HAVE THE BEST CHC FOR SEEING A LONGER PERIOD OF WINTRY PCPN WITH
H85-75 TEMPS REMAINING BLO 0C THERE FOR A LONGER TIME. NOT OUT OF
THE QUESTION ADVY SN MAY FALL OVER THE HIER TERRAIN OF THE KEWEENAW
SUN AFTN/EVNG. NEGATIVELY TILTED APPEARANCE OF SHRTWV/VERY DIFFLUENT
SW FLOW ALF/MSTR SURGE WITH FCST PWAT 0.75 TO 1 INCH SUN EVNG...OR
UP TO 200 PCT OF NORMAL...INDICATE QPF NEAR 1 INCH IN SOME PLACES IS
ON TRACK. RUNOFF FM THIS RA IN THE PRESENCE OF LINGERING SN PILES
MAY CAUSE SOME PONDING OF WATER. ALTHOUGH FCST H85-5 LAPSE RATES ARE
NOT MUCH MORE UNSTABLE THAN MOIST ADIABATIC...DECIDED TO INCLUDE
MENTION OF ELEVATED TS UNDER THE MOST IMPRESSIVE MOISTENING/AXIS OF
H85 LLJ GIVEN IMPRESSIVE DYNAMICS/NEGATIVE TILT OF SHRTWV. ARRIVAL
OF DRY SLOT SUN NGT WL DIMINISH POPS SW-NE AFTER THE EVNG. IN
FACT...FCST SDNGS INDICATE THERE MAY BE SOME CLRG OVER THE SW LATE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 415 PM EDT SAT APR 13 2013
ACTIVE PATTERN ACROSS THE CONUS CONTINUES INTO NEXT WEEKEND AS A
LARGE SCALE UPPER TROUGH MOVES FROM THE W COAST MON TO THE CENTRAL
CONUS BY NEXT SAT...WITH PIECES OF SMALLER SCALE ENERGY EJECTING OFF
THE TROUGH THROUGH THE REGION.
STARTING THE PERIOD OFF 12Z MON...A STACKED CLOSED LOW WILL BE OVER
NRN MN WITH AN OCCLUDED FRONT FROM THE LOW TO NRN LAKE
SUPERIOR...AND THE ASSOCIATED WARM FRONT EXTENDING E FROM NRN LAKE
SUPERIOR INTO ONTARIO AND THE COLD FRONT FROM NRN LAKE SUPERIOR TO
FAR ERN UPPER MI. AT THIS POINT...THE PRECIP THAT MOVED OVER THE CWA
AHEAD OF THE COLD FRONT WILL BE MOSTLY E OF THE CWA. THE DRY SLOT
BEHIND THE COLD FRONT WILL BRING VERY DRY AIR INITIALLY THROUGH MOST
OF THE SOUNDING...BUT WRAP AROUND LOW LEVEL MOISTURE BELOW 800MB WILL
RETURN TO AT LEAST NW UPPER MI /MODELS DIFFER ON THE AREAL EXTENT OF
THE MOISTURE/ AS THE LOW MOVES N OF LAKE SUPERIOR TO JAMES BAY BY
12Z TUE. THIS MAY RESULT IN SOME CONVECTIVE WINTRY MIX SHOWERS WHERE
THERE IS SUFFICIENT LOW LEVEL MOISTURE TO TAP INTO STEEP LOW LEVEL
LAPSE RATES...MAINLY MON INTO EARLY MON NIGHT. WILL INTRODUCE SOME
LOW END POPS FOR THIS POSSIBILITY TO NW UPPER MI. WITH THE STEEP LOW
LEVEL LAPSE RATES...WE SHOULD SEE MIXING TO AROUND 800MB ON
MON...AND WITH SW 800-900MB WINDS AOA 40KTS...IT WILL MAKE FOR GUSTY
SFC WINDS. MAY END UP NEEDING A WIND ADVISORY IN SOME
LOCATIONS...BUT TOO EARLY TO SAY WHERE AT THIS POINT AS MODELS DO
VARY IN STRENGTH AND LOCATION OF BEST LOW LEVEL WINDS. COULD ALSO
SEE SOME DOWNSLOPE ENHANCEMENT OF THE WINDS...ESPECIALLY NEAR LAKE
SUPERIOR ON MARQUETTE COUNTY WITH THE SW WINDS.
EVEN THOUGH 850MB TEMPS DROP BY 7C OR MORE FROM SUN NIGHT INTO
MON...SHOULD STILL BE ABLE TO SEE TEMPS WARM INTO THE 40S /EVEN
AROUND 50 OVER THE SCENTRAL CWA/ MON AFTERNOON DUE TO GOOD LOW LEVEL
MIXING MIXING. THESE WARMER TEMPS AND GUSTY WINDS...COMBINED WITH
SUNSHINE /ESPECIALLY OVER THE CENTRAL AND ERN CWA/ AND RAIN SUN
NIGHT...COULD SEE SOME MELTING OF THE SNOWPACK MON. PROBABLY WILL
NOT LOSE TOO MUCH SNOW PACK...BUT SOME REDUCTION IS CERTAINLY
POSSIBLE.
THE FRONTAL ZONE STALLS WELL TO OUR S THROUGH TUE NIGHT AS UPPER
RIDGING BUILDS OVER THE CWA. THE NRN STREAM JET THEN PUSHES THROUGH
THE CWA TUE NIGHT AS THE UPPER TROUGH OVER THE WRN CONUS SHARPENS UP
AND MOVES TO THE INTERMOUNTAIN WEST. NRN AND SRN STREAM INTERACTION
ALONG THE SRN END OF THE TROUGH WILL CAUSE IT TO DEEPEN AND SHARPEN
UP FURTHER AS IT MOVES E FROM HUDSON BAY TO MN TO TX BY 00Z FRI AS
UPPER RIDGING BUILDS E OF THE CWA. BY LATE WED...WITH THE PRESSURE
GRADIENT TIGHTENING...THE NOW PHASED SRN AND NRN JET STREAM ARCING
FROM W TO N OF THE CWA WILLS STRENGTHEN TO AOA 120KTS. THIS LEADS TO
RAPID SFC CYCLOGENESIS ALONG THE FRONTAL ZONE OVER MO. THE 850MB
FRONTAL ZONE WILL MOVE N INTO THE CWA WED...AND WHEN COMBINED WITH
THE FORCING FROM THE RIGHT ENTRANCE REGION OF THE UPPER JET WILL
LEAD TO PRECIP BY WED AFTERNOON. THE EXACT PLACEMENT AND TYPE OF
PRECIP REMAINS IN QUESTION DUE TO MODEL DISAGREEMENT...BUT GENERALLY
EXPECT SNOW OVER THE NW CWA AND RAIN OVER THE SE CWA...AND THIS
PRECIP SHOULD BE RELATIVELY MINOR ACCUMULATION WISE. PRECIP AMOUNTS
THEN BECOME MORE OF A CONCERN WED NIGHT AND THU AS THE SFC LOW MOVES
ACROSS LAKE MI AND LOWER MI LATE WED NIGHT INTO THU. THE 12Z/13 GFS
AND 00Z/13 ECMWF AGREE PRETTY WELL ON BRINGING THE SFC LOW ACROSS
NRN LOWER MI...BUT THE ECMWF IS ABOUT 6 HOURS FASTER THAN THE GFS AND
NOT AS DEEP WITH THE SFC LOW. OVERALL...A MINOR DIFFERENCE THIS FAR
OUT WITH THE VOLATILE NATURE OF THIS TYPE OF SYSTEM. THINK THAT
MODELS ARE NOT SETTLED AND THINGS WILL CHANGE OVER THE NEXT FEW
DAYS...BUT THE GENERAL IDEA SEEMS GOOD. AT THIS POINT...THERMAL
FIELDS ARE SIMILAR BETWEEN THE MODELS...WITH TEMPS COLD ENOUGH FOR
MAINLY SNOW OVER THE NW CWA...AND MAINLY RAIN OVER THE SE CWA...AT
LEAST UNTIL COLD AIR ARRIVES LATE THU INTO THU NIGHT. SIGNIFICANT
PRECIP AMOUNTS WILL BE POSSIBLE AS MODELS SHOW BETWEEN 0.3 INCHES
AND AROUND 1 INCH OF QPF...BUT VARY ON THE EXACT PLACEMENT OF THIS
PRECIP. STILL SOMETHING TO KEEP A CLOSE EYE ON.
BY LATE THU INTO FRI...ADDITIONAL ENERGY ROUNDING THE BASE OF THE
UPPER TROUGH CAUSES THE SFC LOW TO STALL SOME /OR MORE REDEVELOP ON
THE SW SIDE/. THE MAIN IMPACT THIS HAS ON OUR WEATHER IS TO KEEP
BETTER MOISTURE AND A SFC TROUGH STRETCHED BACK ACROSS LAKE SUPERIOR
AS THE UPPER TROUGH AND MUCH COLDER AIR MOVES ACROSS THE CWA. IF
THIS DOES INDEED COME TO REALITY...LAKE EFFECT SNOW WOULD BE THE
RESULT AS 850MB TEMPS FALL TO AROUND -13C AHEAD OF THE UPPER TROUGH.
LES SHOULD THEN CONTINUE INTO AT LEAST PART OF SATURDAY...BUT
CONFIDENCE IN OVERALL PATTERN DECLINES RAPIDLY THROUGH THE DAY SAT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 740 PM EDT SAT APR 13 2013
AT KIWD...CLOUDS HAVE RECENTLY CLEARED OUT...AND EXPECT VFR
CONDITIONS TO PREVAIL INTO EARLY SAT AFTN. AT KCMX...MVFR CIGS
SHOULD SCATTER OUT BY LATE EVENING AS LOW-LEVEL FLOW BECOMES MORE
DIFFLUENT. VFR CONDITIONS WILL THEN PREVAIL UNTIL LATE SAT AFTN. AT
KSAW...DOWNSLOPING WNW LOW-LEVEL FLOW SHOULD LEAD TO LOW VFR CIGS
SCATTERING OUT BY 06Z...AND VFR CONDITIONS WILL CONTINUE UNTIL LATE
SAT AFTN. VIGOROUS LOW PRES SYSTEM APPROACHING THE UPPER LAKES LATE
SAT WILL BRING A SHIELD OF PCPN INTO UPPER MI. COLUMN WILL BE COLD
ENOUGH TO SUPPORT SNOW AT THE ONSET. SNOW SHOULD BEGIN AT KIWD
AROUND 20Z AND AT KCMX/KSAW AN HOUR OR TWO LATER. EXPECT A RAPID
DROP TO IFR CONDITIONS AS SNOW BEGINS. AS NOSE OF WARMER AIR ALOFT
SURGES N...PCPN WILL LIKELY MIX WITH SLEET/RAIN AT KIWD BEFORE THE
END OF THIS FCST PERIOD. MIX SHOULD DEVELOP AROUND OR JUST AFTER 00Z
AT KCMX/KSAW. PCPN SHOULD CHANGE TO JUST RAIN AT ALL 3 SITES IN THE
EVENING...THOUGH CHANGEOVER WILL OCCUR LAST AT KCMX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 415 PM EDT SAT APR 13 2013
NW WINDS UP TO 20-25 KTS OVER THE E HALF THIS EVENING WILL BECOME
LIGHT INTO SUN MORNING WITH ARRIVAL/PASSAGE OF HI PRES RIDGE AXIS.
AS THE NEXT LO PRES SYSTEM MOVES FROM THE NORTHERN PLAINS ON SUN
THRU MN SUN NIGHT AND THE PRES GRADIENT TIGHTENS...A STRONGER E WIND
VEERING SE UP TO 30 KTS WILL DEVELOP. OPTED TO ISSUE A GALE WATCH
FOR THE FAR W AND PORTIONS OF THE NCENTRAL AND E FOR LATE SUN/SUN
NIGHT WHERE THE EXPECTED FLOW IS ENHANCED BY TERRAIN INFLUENCES.
AS THE LOW PRESSURE SYSTEM MOVES FROM NORTHERN MN MONDAY MORNING TO
JAMES BY BY TUESDAY MORNING...STRONG SOUTHWEST WINDS MAY GUST TO 35
KNOTS OVER THE WESTERN HALF OF LAKE SUPERIOR MONDAY INTO MONDAY
NIGHT. WINDS THEN DECREASE TUESDAY INTO WEDNESDAY BEFORE INCREASING
OUT OF THE N WEDNESDAY NIGHT INTO FRIDAY WHEN GALES MAY BE POSSIBLE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SUNDAY EVENING THROUGH LATE SUNDAY NIGHT FOR
LSZ264-266.
GALE WATCH FROM SUNDAY EVENING THROUGH LATE SUNDAY NIGHT FOR
LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...KC/TITUS
AREA FORECAST DISCUSSION...CORRECTED
NWS MARQUETTE MI
423 PM EDT SAT APR 13 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 415 PM EDT SAT APR 13 2013
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOWS CLOSED LO
CENTERED OVER ONTARIO TO THE S OF PERSISTENT BLOCKING RDG OVER NE
CANADA IN PREVAILING NEGATIVE NAO PATTERN. WITH DEEP MSTR SHOWN ON
12Z INL/GRB RAOBS...CYC FLOW...H85-7 COLD POCKET WITH H85 TEMPS AS
LO AS -10C TO -12C OVER THE WRN CWA...AND SHRTWVS ROTATING ARND THE
MAIN CLOSED LO...CLDS AND SHSN HAVE LINGERED OVER UPR MI...E
SPECIALLY ALONG SFC LO PRES TROF ASSOCIATED WITH ONE OF THESE
SHRTWVS THAT IS CROSSING THE CWA EARLY THIS AFTN. TEMPS REMAIN WELL
BLO NORMAL FOR MID APRIL. OVER FAR WRN MN INTO THE NRN PLAINS...A
SFC RDG AXIS AND DRY MID LVL AIR SHOWN ON THE 12Z BISMARCK RAOB ARE
CAUSING DRY WX EVEN THOUGH SOME LO CLDS LINGER WITH MSTR TRAPPED BLO
INVRN BASE AT H8 SHOWN ON THE BISMARCK SOUNDING. ANOTHER POWERFUL
SHRTWV IS MOVING ONSHORE INTO THE PAC NW WITH 00Z-12Z H3-5 HGT FALLS
UP TO 150-200M.
MAIN FCST CONCERNS THRU TNGT ARE FOCUSED ON SHSN/CLD TRENDS AS THE
UPR LO OVER ONTARIO SLOWLY FILLS AND SHIFTS TO THE E. FOCUS ON
SUN/SUN NGT SHIFTS TO TIMING AND IMPACT OF SHRTWV NOW MOVING INTO
THE PAC NW.
LATE TODAY/TNGT...AS UPR LO IN ONTARIO SLOWLY WEAKENS...H5 HGT IS
PROGGED TO RISE 120M OVER UPR MI BTWN 00Z-12Z SUN UNDER VIGOROUS
DEEP LYR QVECTOR DVGC. AS THE CYC NW FLOW WEAKENS...EXPECT LINGERING
SHSN LATE THIS AFTN/EVNG TO DIMINISH STEADILY THRU THE NGT AND END
IN THE EARLY MRNG HRS ON SUN. WITH SOME CLRG LATE AT LEAST OVER THE
W AND CENTRL AND LGT WINDS UNDER THE SFC RDG AXIS...EXPECT TEMPS TO
FALL INTO THE TEENS...WELL BLO NORMAL FOR THE SEASON. WITH CLDS/LLVL
MSTR LINGERING LONGER IN A PERSISTENT NW FLOW OVER THE E...THOSE
AREAS WL BE WARMER.
SUN/SUN NGT...EXPECT A DRY START TO THE DAY WITH SFC HI PRES RDG
SLOWLY DEPARTING TO THE E. BUT ANY MRNG SUNSHINE WL QUICKLY FADE
BEHIND INCRSG CLDS AS VIGOROUS ISENTROPIC ASCENT/DEEPER MSTR/SW FLOW
ALF BTWN THE DEPARTING HI AND INCRSG NEGATIVELY TILTED SHRTWV/SFC LO
MOVING THRU THE NRN PLAINS AND TOWARD MN LATE IN THE DAY OVERSPREADS
UPR MI. AS UPR DVGC/BAND OF H85-7 FGEN AHEAD OF ATTENDANT WARM FNT
MOVES IN AFT 18Z...EXPECT PCPN TO OVERSPREAD THE CWA BY 00Z MON...
ESPECIALLY OVER THE W HALF CLOSER TO SHARPER DYNAMICS AND WHERE
MOISTENING/H85 MSTR CNVGC IS MOST IMPRESSIVE. PTYPE WL BE A CONCERN
SUN AFTN/EVNG. NAM/GFS FCST SDNGS INDICATE SATURATED TEMP PROFILE WL
AT LEAST INITIALLY BE COMPLETELY SUB ZERO...BUT THEN SHOW ELEVATED
WARM LYR ABV SUB ZERO NEAR SFC LYR. WITH ELEVATED WARMING INITIALLY
LIFTING TEMPS ABV 0C IN THE H8-75 LYR...SUSPECT SLEET WL MIX WITH
THE SN. THESE FCST SDNGS ALSO SUG PCPN MAY BE AT LEAST MIXED WITH
SOME FZRA FOR A TIME LATE IN THE AFTN/EVNG OVER AT LEAST THE HIER
TERRAIN OF THE W HALF AS THE ELEVATED WARM LYR DEEPENS AND TEMPS IN
THE LOWER LYR WARM TOO MUCH FOR DROPS TO REFREEZE. BUT THESE SDNGS
ALSO APPEAR TO UNDERDO THE SFC WARMING IN THE AFTN FOLLOWING AT
LEAST SOME MRNG SUNSHINE. WITH SOME LINGERING LLVL DRY AIR...
EVAPORATIVE COOLING COULD MAINTAIN SUB 32 NEAR SFC WBLB TEMPS. BUT
THE FCST NEAR SFC SE FLOW IN THE ABSENCE OF HI PRES CENTER OVER
ONTARIO AS WELL AS ARRIVAL OF PCPN AT MAX HEATING TIME THIS LATE IN
THE SEASON WOULD ALSO TEND TO MINIMIZE THIS THREAT. HIER GFS MOS
TEMPS SEEM MORE APPROPRIATE FOR THE TEMPS FCST THAN RAW MODEL
GUIDANCE. FOR NOW...WL FCST A SN/SLEET MIX AT THE ONSET
TRANSITIONING TO RA SUN EVNG AS MUCH WARMER/MSTR LLVL AIR SURGES
INTO THE UPR LKS ON THE HEELS OF H85 SW WINDS FCST UP TO 60-70KTS BY
06Z MON. EXPECT LITTLE IF ANY FALL OF TEMPS SUN NGT. THE NW CWA WL
HAVE THE BEST CHC FOR SEEING A LONGER PERIOD OF WINTRY PCPN WITH
H85-75 TEMPS REMAINING BLO 0C THERE FOR A LONGER TIME. NOT OUT OF
THE QUESTION ADVY SN MAY FALL OVER THE HIER TERRAIN OF THE KEWEENAW
SUN AFTN/EVNG. NEGATIVELY TILTED APPEARANCE OF SHRTWV/VERY DIFFLUENT
SW FLOW ALF/MSTR SURGE WITH FCST PWAT 0.75 TO 1 INCH SUN EVNG...OR
UP TO 200 PCT OF NORMAL...INDICATE QPF NEAR 1 INCH IN SOME PLACES IS
ON TRACK. RUNOFF FM THIS RA IN THE PRESENCE OF LINGERING SN PILES
MAY CAUSE SOME PONDING OF WATER. ALTHOUGH FCST H85-5 LAPSE RATES ARE
NOT MUCH MORE UNSTABLE THAN MOIST ADIABATIC...DECIDED TO INCLUDE
MENTION OF ELEVATED TS UNDER THE MOST IMPRESSIVE MOISTENING/AXIS OF
H85 LLJ GIVEN IMPRESSIVE DYNAMICS/NEGATIVE TILT OF SHRTWV. ARRIVAL
OF DRY SLOT SUN NGT WL DIMINISH POPS SW-NE AFTER THE EVNG. IN
FACT...FCST SDNGS INDICATE THERE MAY BE SOME CLRG OVER THE SW LATE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 415 PM EDT SAT APR 13 2013
ACTIVE PATTERN ACROSS THE CONUS CONTINUES INTO NEXT WEEKEND AS A
LARGE SCALE UPPER TROUGH MOVES FROM THE W COAST MON TO THE CENTRAL
CONUS BY NEXT SAT...WITH PIECES OF SMALLER SCALE ENERGY EJECTING OFF
THE TROUGH THROUGH THE REGION.
STARTING THE PERIOD OFF 12Z MON...A STACKED CLOSED LOW WILL BE OVER
NRN MN WITH AN OCCLUDED FRONT FROM THE LOW TO NRN LAKE
SUPERIOR...AND THE ASSOCIATED WARM FRONT EXTENDING E FROM NRN LAKE
SUPERIOR INTO ONTARIO AND THE COLD FRONT FROM NRN LAKE SUPERIOR TO
FAR ERN UPPER MI. AT THIS POINT...THE PRECIP THAT MOVED OVER THE CWA
AHEAD OF THE COLD FRONT WILL BE MOSTLY E OF THE CWA. THE DRY SLOT
BEHIND THE COLD FRONT WILL BRING VERY DRY AIR INITIALLY THROUGH MOST
OF THE SOUNDING...BUT WRAP AROUND LOW LEVEL MOISTURE BELOW 800MB WILL
RETURN TO AT LEAST NW UPPER MI /MODELS DIFFER ON THE AREAL EXTENT OF
THE MOISTURE/ AS THE LOW MOVES N OF LAKE SUPERIOR TO JAMES BAY BY
12Z TUE. THIS MAY RESULT IN SOME CONVECTIVE WINTRY MIX SHOWERS WHERE
THERE IS SUFFICIENT LOW LEVEL MOISTURE TO TAP INTO STEEP LOW LEVEL
LAPSE RATES...MAINLY MON INTO EARLY MON NIGHT. WILL INTRODUCE SOME
LOW END POPS FOR THIS POSSIBILITY TO NW UPPER MI. WITH THE STEEP LOW
LEVEL LAPSE RATES...WE SHOULD SEE MIXING TO AROUND 800MB ON
MON...AND WITH SW 800-900MB WINDS AOA 40KTS...IT WILL MAKE FOR GUSTY
SFC WINDS. MAY END UP NEEDING A WIND ADVISORY IN SOME
LOCATIONS...BUT TOO EARLY TO SAY WHERE AT THIS POINT AS MODELS DO
VARY IN STRENGTH AND LOCATION OF BEST LOW LEVEL WINDS. COULD ALSO
SEE SOME DOWNSLOPE ENHANCEMENT OF THE WINDS...ESPECIALLY NEAR LAKE
SUPERIOR ON MARQUETTE COUNTY WITH THE SW WINDS.
EVEN THOUGH 850MB TEMPS DROP BY 7C OR MORE FROM SUN NIGHT INTO
MON...SHOULD STILL BE ABLE TO SEE TEMPS WARM INTO THE 40S /EVEN
AROUND 50 OVER THE SCENTRAL CWA/ MON AFTERNOON DUE TO GOOD LOW LEVEL
MIXING MIXING. THESE WARMER TEMPS AND GUSTY WINDS...COMBINED WITH
SUNSHINE /ESPECIALLY OVER THE CENTRAL AND ERN CWA/ AND RAIN SUN
NIGHT...COULD SEE SOME MELTING OF THE SNOWPACK MON. PROBABLY WILL
NOT LOSE TOO MUCH SNOW PACK...BUT SOME REDUCTION IS CERTAINLY
POSSIBLE.
THE FRONTAL ZONE STALLS WELL TO OUR S THROUGH TUE NIGHT AS UPPER
RIDGING BUILDS OVER THE CWA. THE NRN STREAM JET THEN PUSHES THROUGH
THE CWA TUE NIGHT AS THE UPPER TROUGH OVER THE WRN CONUS SHARPENS UP
AND MOVES TO THE INTERMOUNTAIN WEST. NRN AND SRN STREAM INTERACTION
ALONG THE SRN END OF THE TROUGH WILL CAUSE IT TO DEEPEN AND SHARPEN
UP FURTHER AS IT MOVES E FROM HUDSON BAY TO MN TO TX BY 00Z FRI AS
UPPER RIDGING BUILDS E OF THE CWA. BY LATE WED...WITH THE PRESSURE
GRADIENT TIGHTENING...THE NOW PHASED SRN AND NRN JET STREAM ARCING
FROM W TO N OF THE CWA WILLS STRENGTHEN TO AOA 120KTS. THIS LEADS TO
RAPID SFC CYCLOGENESIS ALONG THE FRONTAL ZONE OVER MO. THE 850MB
FRONTAL ZONE WILL MOVE N INTO THE CWA WED...AND WHEN COMBINED WITH
THE FORCING FROM THE RIGHT ENTRANCE REGION OF THE UPPER JET WILL
LEAD TO PRECIP BY WED AFTERNOON. THE EXACT PLACEMENT AND TYPE OF
PRECIP REMAINS IN QUESTION DUE TO MODEL DISAGREEMENT...BUT GENERALLY
EXPECT SNOW OVER THE NW CWA AND RAIN OVER THE SE CWA...AND THIS
PRECIP SHOULD BE RELATIVELY MINOR ACCUMULATION WISE. PRECIP AMOUNTS
THEN BECOME MORE OF A CONCERN WED NIGHT AND THU AS THE SFC LOW MOVES
ACROSS LAKE MI AND LOWER MI LATE WED NIGHT INTO THU. THE 12Z/13 GFS
AND 00Z/13 ECMWF AGREE PRETTY WELL ON BRINGING THE SFC LOW ACROSS
NRN LOWER MI...BUT THE ECMWF IS ABOUT 6 HOURS FASTER THAN THE GFS AND
NOT AS DEEP WITH THE SFC LOW. OVERALL...A MINOR DIFFERENCE THIS FAR
OUT WITH THE VOLATILE NATURE OF THIS TYPE OF SYSTEM. THINK THAT
MODELS ARE NOT SETTLED AND THINGS WILL CHANGE OVER THE NEXT FEW
DAYS...BUT THE GENERAL IDEA SEEMS GOOD. AT THIS POINT...THERMAL
FIELDS ARE SIMILAR BETWEEN THE MODELS...WITH TEMPS COLD ENOUGH FOR
MAINLY SNOW OVER THE NW CWA...AND MAINLY RAIN OVER THE SE CWA...AT
LEAST UNTIL COLD AIR ARRIVES LATE THU INTO THU NIGHT. SIGNIFICANT
PRECIP AMOUNTS WILL BE POSSIBLE AS MODELS SHOW BETWEEN 0.3 INCHES
AND AROUND 1 INCH OF QPF...BUT VARY ON THE EXACT PLACEMENT OF THIS
PRECIP. STILL SOMETHING TO KEEP A CLOSE EYE ON.
BY LATE THU INTO FRI...ADDITIONAL ENERGY ROUNDING THE BASE OF THE
UPPER TROUGH CAUSES THE SFC LOW TO STALL SOME /OR MORE REDEVELOP ON
THE SW SIDE/. THE MAIN IMPACT THIS HAS ON OUR WEATHER IS TO KEEP
BETTER MOISTURE AND A SFC TROUGH STRETCHED BACK ACROSS LAKE SUPERIOR
AS THE UPPER TROUGH AND MUCH COLDER AIR MOVES ACROSS THE CWA. IF
THIS DOES INDEED COME TO REALITY...LAKE EFFECT SNOW WOULD BE THE
RESULT AS 850MB TEMPS FALL TO AROUND -13C AHEAD OF THE UPPER TROUGH.
LES SHOULD THEN CONTINUE INTO AT LEAST PART OF SATURDAY...BUT
CONFIDENCE IN OVERALL PATTERN DECLINES RAPIDLY THROUGH THE DAY SAT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 147 PM EDT SAT APR 13 2013
LIGHT TO SOMETIMES MODERATE SNOW SHOWERS AFFECTING MAINLY IWD AND
SAW WILL DIMINISH THROUGHOUT THE AFTERNOON AS A TROUGH PASSES
THROUGH AND MOVE SOUTH OF THE AREA. EXPECT TEMPORARY VIS
RESTRICTIONS IN THE LIFR RANGE TO IMPROVE TO VFR VIS AT ALL SITES BY
LATER AFTERNOON. CLOUDS WILL START TO THIN OUT BY THIS
EVENING...THOUGH UPSLOPE FLOW AROUND CMX MAY KEEP A FEW HIGH-END
MVFR CLOUDS AROUND OVERNIGHT.
AN APPROACHING SYSTEM WILL BEGIN TO SPREAD MID-LEVEL CLOUDS ACROSS
UPPER MI LATE SUNDAY MORNING INTO THE AFTERNOON. IWD CAN EXPECT TO
SEE A MIX OF HEAVY SLEET...SNOW AND RAIN BY 21Z SUNDAY. CMX AND SAW
SHOULD SEE THE SAME BY 00Z MONDAY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 415 PM EDT SAT APR 13 2013
NW WINDS UP TO 20-25 KTS OVER THE E HALF THIS EVENING WILL BECOME
LIGHT INTO SUN MORNING WITH ARRIVAL/PASSAGE OF HI PRES RIDGE AXIS.
AS THE NEXT LO PRES SYSTEM MOVES FROM THE NORTHERN PLAINS ON SUN
THRU MN SUN NIGHT AND THE PRES GRADIENT TIGHTENS...A STRONGER E WIND
VEERING SE UP TO 30 KTS WILL DEVELOP. OPTED TO ISSUE A GALE WATCH
FOR THE FAR W AND PORTIONS OF THE NCENTRAL AND E FOR LATE SUN/SUN
NIGHT WHERE THE EXPECTED FLOW IS ENHANCED BY TERRAIN INFLUENCES.
AS THE LOW PRESSURE SYSTEM MOVES FROM NORTHERN MN MONDAY MORNING TO
JAMES BY BY TUESDAY MORNING...STRONG SOUTHWEST WINDS MAY GUST TO 35
KNOTS OVER THE WESTERN HALF OF LAKE SUPERIOR MONDAY INTO MONDAY
NIGHT. WINDS THEN DECREASE TUESDAY INTO WEDNESDAY BEFORE INCREASING
OUT OF THE N WEDNESDAY NIGHT INTO FRIDAY WHEN GALES MAY BE POSSIBLE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SUNDAY EVENING THROUGH LATE SUNDAY NIGHT FOR
LSZ264-266.
GALE WATCH FROM SUNDAY EVENING THROUGH LATE SUNDAY NIGHT FOR
LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...TK
MARINE...KC/TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
448 PM EDT FRI APR 12 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 445 PM EDT FRI APR 12 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER NRN
WI WITH SHORTWAVE SPOKES INTO SRN UPPER MI AND WRN LAKE SUPERIOR.
WIDESPREAD LIGHT SNOW (VSBY IN THE 1-4SM RANGE) STILL PREVAILED
ACROSS MUCH OF UPPER MI WITH THE FAVORABLE UPPER LEVEL DIV AND
700-300 MB QVECTOR CONV TO THE NORTH OF THE LOW. AT THE SFC...LOW
PRES WAS LOCATED OVER NW LOWER MI NEAR TVC WITH A TROUGH EXTENDING
TO THE EAST TO LAKE ONTARIO. WITH THE SFC-850 MB TROUGH EDGING
CLOSER TO THE AREA...THE ENE LOW LEVEL FLOW HAD DIMINISHED. EVEN
WITH 850 MB TEMPS DOWN TO AROUND -11C...RADAR SHOWED ONLY MINIMAL IF
ANY LAKE ENHANCEMENT INTO N CNTRL UPPER MI.
EXPECT LIGHT SNOW ASSOCIATED WITH THE MID LEVEL LOW TO PERSIST THIS
EVENING BUT WITH ACCUMULATIONS OF LESS THAN AN INCH. WITH THE LOW
LEVEL TROUGH AXIS SHIFTING TO NEAR E UPPER MI...LOW LEVEL CONV FOR
LAKE ENHANCED SNOW WILL BE LESS FAVORABLE THIS EVENING. HOWEVER...AS
THE TROUGH SHIFTS TO THE EAST AND WINDS BACK MORE NRLY AND STRENGTHEN
OVERNIGHT INTO SATURDAY MORNING...LAKE ENHANCED SNOW IS EXPECTED TO
BECOME HEAVIER OVER THE WEST AND THEN SHIFT INTO N CNTRL UPPER MI
LATE TONIGHT INTO SATURDAY MORNING. EVEN WITH ONLY MARGINAL 850 MB
TEMPS NEAR -12C AND LAKE INDUCED CAPES TO NEAR 300 J/KG...ABUNDANT
850-500 MB MOISTURE AND CYCLONIC LOW LEVEL FLOW WILL FAVOR AT LEAST
LIGHT TO MODERATE SNOW. SNOW/WATER RATIOS SHOULD ALSO BECOME MORE
FAVORABLE WITH SIGNIFICANT UPWARD MOTION IN THE 850-750 MB DGZ LAYER.
EVEN WITH THE SNOW TAPERING OFF FOR A TIME TONIGHT...THE ADVISORIES
OVER THE NW HALF WERE EXTENDED INTO SATURDAY WITH HIGHER SNOWFALL
RATES AGAIN DEVELOPING. ADDITIONAL AMOUNTS FROM 00Z-18Z SHOULD STILL
REMAIN IN THE 2 TO 6 INCH RANGE.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 445 PM EDT FRI APR 12 2013
THE LONG RANGE LOOKS TO FEATURE AN WX ACTIVE PATTERN WITH BLO NORMAL
TEMPS OVERALL AS MEAN UPR TROF OVER CENTRAL NAMERICA LINGERS. MAIN
FOCUS WL BE ON NEXT LO PRES DISTURBANCE PROGGED TO IMPACT THE CWA
LATE SUN THRU SUN NGT.
SAT NGT...SHRTWV RDG AXIS BTWN DEPARTING/WEAKENING CLOSED LO OVER SE
CANADA AND NEXT SHRTWV/SFC LO MOVING INTO THE NRN PLAINS IS FCST TO
BLD INTO THE GRT LKS. WITH ARRIVAL OF SFC HI PRES RDG/DRYING ALF
UNDER THE RISING HGTS...LINGERING -SHSN UNDER MORE PERSISTENT CYC NW
FLOW/DEEPER MSTR/H85 TEMPS AS LO AS -10C IN THE EVNG OVER THE
NCENTRAL AND E WL END AND GIVE WAY TO AT LEAST PARTIAL CLRG.
SUN/SUN NGT...EXPECT A DRY START TO THE DAY ON SUN WITH SFC HI PRES
RDG SLOWLY DEPARTING TO THE E. BUT ANY MRNG SUNSHINE WL QUICKLY FADE
BEHIND INCRSG CLDS AS VIGOROUS ISENTROPIC ASCENT/SW FLOW BTWN THE
DEPARTING HI AND NEXT SHRTWV/SFC LO MOVING THRU THE NRN PLAINS AND
TOWARD MN LATE ON SUN OVERSPREADS UPR MI. AS UPR DVGC/BAND OF H5-7
FGEN AHEAD OF ATTENDANT WARM FNT MOVES IN AFT 18Z...EXPECT PCPN TO
OVERSPREAD THE CWA BY 00Z MON. PTYPE WL BE A CONCERN AT THE ONSET OF
THE PCPN EVENT SUN AFTN/EVNG. NAM/GFS FCST SDNGS INDICATE SATURATED
TEMP PROFILE WL AT LEAST INITIALLY BE COMPLETELY SUB ZERO...BUT THEN
SHOW ELEVATED WARM LYR ABV SUB ZERO NEAR SFC LYR. IN FACT...THESE
FCST SDNGS ALSO SUG PCPN MAY BE AT LEAST MIXED WITH SOME ZR FOR A
TIME LATE IN THE AFTN/EVNG OVER AT LEAST THE HIER TERRAIN OF THE W
HALF. BUT THESE SDNGS ALSO APPEAR TO UNDERDO THE SFC WARMING IN THE
AFTN FOLLOWING AT LEAST SOME MRNG SUNSHINE. WITH SOME LINGERING LLVL
DRY AIR...EVAPORATIVE COOLING COULD MAINTAIN SUB 32 NEAR SFC WBLB
TEMPS. BUT THE FCST NEAR SFC SE FLOW IN THE ABSENCE OF HI PRES
CENTER OVER ONTARIO AS WELL AS ARRIVAL OF PCPN AT MAX HEATING TIME
THIS LATE IN THE SEASON WOULD ALSO TEND TO MINIMIZE THIS THREAT.
HIER MOS TEMPS SEEM MORE APPROPRIATE FOR THE TEMPS THAN RAW MODEL
GUIDANCE. FOR NOW...WL FCST A SN/SLEET MIX AT THE ONSET
TRANSITIONING TO RA SUN EVNG AS MUCH WARMER/MSTR LLVL AIR SURGES
INTO THE UPR LKS ON THE HEELS OF H85 SW WINDS FCST UP TO 50-60KTS BY
06Z MON. EXPECT LITTLE IF ANY FALL OF TEMPS SUN NGT. THE NW CWA WL
HAVE THE BEST CHC FOR SEEING A LONGER PERIOD OF WINTRY PCPN WITH H85
TEMPS REMAINING BLO 0C THERE FOR A LONGER TIME. NEGATIVELY TILTED
APPEARANCE OF SHRTWV/VERY DIFFLUENT SW FLOW ALF/MSTR SURGE WITH PWAT
FCST UP TO 1 INCH SUN EVNG...OR 200 PCT OF NORMAL...INDICATE QPF
NEARING 1 INCH IS ON TRACK. RUNOFF FM THIS RA IN THE PRESENCE OF
LINGERING SN PILES MAY CAUSE SOME PONDING OF WATER. CONSIDERED
ADDING A CHC OF ELEVATED TS UNDER THE MOST IMPRESSIVE
MOISTENING/AXIS OF H85 LLJ...BUT FCST SDNGS SHOW H85-5 LAPSE RATES
NOT QUITE MOIST ADIABATIC. ARRIVAL OF DRY SLOT SUN NGT WL DIMINISH
POPS SW-NE AFTER THE EVNG.
MON...DRY SLOT ON THE SRN FLANK OF SHRTWV/SFC LO TRACKING ENEWD THRU
SRN ONTARIO WL END ANY LINGERING PCPN OVER THE E AND SCNTRL
ASSOCIATED WITH DEPARTING WARM CONVEYOR BELT. THE GFS IS MOST
AGGRESSIVE AT SHOWING SOME DEEPER MSTR/PCPN ON THE SE FLANK OF THE
UPR LO IMPACTING THE WRN ZNS...BUT BULK OF GUIDANCE INDICATES DEEPER
MSTR/PCPN WL REMAIN IN MN CLOSER TO LINGERING LO PRES TROF ON SW
FLANK OF LO DEPARTING TO THE NE. EXPECT AT LEAST PARTIAL SUNSHINE...
WHICH SHOULD BOOST MAX TEMPS INTO THE 40S AT MOST PLACES WITH H85
TEMPS FCST JUST A COUPLE DEGREES BLO 0C.
EXTENDED...DRYING/LLVL ACYC FLOW UNDER SLOWLY RISING HGTS BTWN
DEPARTING LO AND DEEPENING TROF IN THE ROCKIES WL BRING DRY WX AND
SEASONABLE TEMPS FOR MON NGT THRU TUE NGT. AS LO PRES LIFTS NEWD OUT
OF THE WRN TROF AND TOWARD THE GRT LKS ON WED INTO THU...ANOTHER
SGNFT MIXED PCPN EVENT APPEARS LIKELY. IF THE WELL CLUSTERED 00Z
ECMWF...CNDN...AND UKMET VERIFY...THE PTYPE WOULD BE MAINLY SN OVER
THE W HALF OF THE CWA WITH WARNING SN TOTALS LIKELY. THE 00Z/06Z/12Z
GFS ON THE OTHER HAND SHOWS A MUCH WEAKER LO TRACKING FARTHER TO THE
S AND MUCH LESS PCPN IMPACTING MAINLY THE SE HALF OF UPR MI. ALL
THESE SCENARIOS ARE WITHIN THE SPREAD SHOWN BY THE 00Z GFS ENSEMBLE
MEMBERS. COLDER AIR WITH SHSN WL FOLLOW ON FRI AS THE 00Z ECMWF
SHOWS H85 TEMPS TUMBLING TO -15C UNDER CYC NW FLOW LEFT IN THE WAKE
OF DEPARTING LO PRES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 150 PM EDT FRI APR 12 2013
EXPECT SCATTERED TO NUMEROUS SNOW SHOWERS THIS AFTERNOON INTO THIS
EVENING WITH VARIABLE VISIBILITIES WILL LIKELY BE BOUNCING BETWEEN 1
AND 4 MILES. FROM THIS AFTERNOON INTO THIS EVENING...LAKE
INFLUENCES WILL ENHANCE THE SNOW AT KCMX/KSAW AT TIMES. AS THE UPPER
LOW IS OVERHEAD AND THE SURFACE LOW MOVES NORTHEAST INTO
CANADA...WINDS WILL TURN MORE NORTHERLY TONIGHT AND LEAD MAINLY LAKE
ENHANCED SNOWFALL FOR ALL THREE SITES. VISIBILITIES WERE KEPT DOWN
DURING THAT PERIOD AND ALSO LOWERED CEILINGS DUE TO WINDS BECOMING
MORE FAVORABLE TO UPSLOPE. THE SNOW SHOULD TAPER OFF SATURDAY BUT
WILL LIKELY REMAIN IN THE LOWER MVFR RANGE INTO THE EARLY AFTERNOON.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 445 PM EDT FRI APR 12 2013
AS LOW PRESSURE OVER LOWER MICHIGAN SLIDES TO THE EAST TONIGHT AND
SATURDAY...WINDS WILL DIMINISH. THIS OCCURS...WINDS WILL GRADUALLY
SHIFT TO THE NORTH-NORTHWEST THROUGH SATURDAY AS A LINGERING SURFACE
TROUGH ROTATES THROUGH LAKE SUPERIOR. ENE GALES LATE THIS AFTERNOON
WILL DIMINISH TO 20 TO 30 KT WINDS TONIGHT AND INTO THE 15 TO 25 KT
RANGE SATURDAY.
WINDS ON SAT NIGHT WILL TURN LIGHT WITH THE ARRIVAL OF A HI PRES
RIDGE. EXPECT INCREASING E WINDS UP TO 25 TO 30 KTS VEERING TO THE
SE ON SUN INTO SUN NIGHT AHEAD OF A LO PRES SYSTEM MOVING FROM THE
NORTHERN PLAINS TOWARD MN. AS THIS LO PASSES THRU ONTARIO ON MON/MON
NIGHT AND THE PRES GRADIENT OVER LAKE SUP DIMINISHES...THE WINDS
WILL SUBSIDE WHILE VEERING TO THE S AND THEN W INTO TUE. EXPECT THE
WINDS TO SHIFT TO THE N BY WED AS HI PRES BUILDS IN CENTRAL CANADA
AND ANOTHER LO PRES SYSTEM MOVES NE THRU THE PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 2 PM EDT SATURDAY FOR MIZ004-005.
WINTER WEATHER ADVISORY UNTIL 8 AM EDT /7 AM CDT/ SATURDAY FOR
MIZ002-009.
WINTER WEATHER ADVISORY UNTIL 11 AM EDT SATURDAY FOR MIZ001-003.
WINTER WEATHER ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ084.
LAKE SUPERIOR...
GALE WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR LSZ264-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...JLB
MARINE...JLB/KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
152 PM EDT FRI APR 12 2013
.UPDATE...
ISSUED AT 1243 PM EDT FRI APR 12 2013
WV IMAGERY AND RUC ANALYSIS INDICATED THAT THE MID/UPPER LEVEL LOW
HAVE MOVED INTO CNTRL WI. ONE SHORTWAVE SPOKE WAS LIFTING THROUGH NW
UPPER MI SUPPORTED LIGHT TO MODERATE SNOW WHILE FORCING CLOSER TO
THE LOW HAS KEPT -SN GOING FROM NRN WI INTO SRN WI WITH VSBY INTO
THE 1SM TO 3SM RANGE. RADAR INDICATED THAT THE SNOW OVER THE ERN
CWA HAD DIMINISHED. ADDITIONAL ACCUMULATIONS OF ONLY AROUND AN INCH
ARE EXPECTED OVER THE SOUTH AND LESS THAN AN INCH OVER THE EAST.
SO...THE WINTER STORM WARNINGS WERE DROPPED OVER THE EAST AND THE
ADVISORY FOR DICKINSON/IRON WILL BE ALLOWED TO EXPIRE AT 18Z. THE
WARNINGS OVER FROM MARQUETTE INTO THE KEWEENAW WERE TRANSITIONED TO
WINTER WEATHER ADVISORIES FOR A MORE PROLONGED PERIOD OF LIGHT TO
MODERATE SNOW INTO SATURDAY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 540 AM EDT FRI APR 12 2013
INITIAL BATCH OF HEAVY SNOW IS MOVING NORTH ACROSS NORTH CENTRAL AND
EASTERN UPPER MICHIGAN AT THIS TIME. THIS IS ASSOCIATED WITH THE
TROWAL FEATURE...SEEN ON 290-315K SFCS...THAT PIVOTS NORTHEAST AND
BEST FORCING SLIDES OFF TO THE EAST THIS MORNING INTO EARLY
AFTERNOON. WOULD EXPECT THE HEAVIEST SNOW TO OCCUR OVER THE NORTH
CENTRAL OVER THE NEXT COUPLE OF HOURS BEFORE THE DRIER MID LEVEL AIR
SEEN ON WATER VAPOR IMAGERY AND GAP BETWEEN THE UPPER LOW AND
INITIAL SHORTWAVE MOVES IN. FARTHER EAST...THERE IS A LITTLE MORE OF
A FETCH WITH THE CLOSER PROXIMITY TO THE DEEPER MOISTURE AXIS MOVING
THROUGH LOWER MICHIGAN AND WOULD EXPECT THE HEAVIER SNOW TO CONTINUE
LONGER INTO THE MORNING HOURS. BUT THEN WITH THE DRIER AIR MOVING IN
BY LATE MORNING...THE SNOW SHOULD QUICKLY DIMINISH FROM SOUTH TO
NORTH THIS AFTERNOON.
TODAY WILL START THE TRANSITION TO A MORE GENERAL LIGHTER SNOW
ACROSS THE CWA...AS THE HEAVIER SNOW SHIFTS TO THE NORTHEAST. THE
UPPER LOW CURRENTLY OVER SOUTHEAST MN AND NORTHEAST IOWA IS EXPECTED
TO ROTATE NORTHEAST AND OVER THE UPPER GREAT LAKES THIS AFTERNOON
AND TONIGHT. EVEN WITH THE TROWAL FEATURE SHIFTING OUT EARLY THIS
MORNING...BROAD 850-500MB Q-VECTOR CONVERGENCE OVER THE AREA THIS
MORNING AHEAD OF THE SHORTWAVE ENERGY MOVING NORTH THROUGH CENTRAL
WISCONSIN SHOULD STILL LEAD TO LIGHT TO OCCASIONALLY MODERATE
SNOWFALL BEHIND THE HEAVIER SNOW. THIS Q-VECTOR CONVERGENCE STAYS
OVER THE NORTHERN HALF OF THE CWA THROUGH THIS AFTERNOON AND
TONIGHT. FARTHER SOUTH...THE LINE OF CONVECTIVE LOOKING SHOWERS ON
THE NORTH SIDE OF THE SHORTWAVE MOVING NORTH THROUGH WISCONSIN
SHOULD GRADUALLY SHIFT NORTH THROUGH THE DAY AND COULD LEAD TO BRIEF
HEAVIER SNOW SHOWERS OVER SOUTHERN UPPER MICHIGAN...ESPECIALLY SINCE
IT LOOKS TO COMBINE DEFORMATION AREA ON THE NW SIDE OF THE LOW
MOVING INTO THE LOWER GREAT LAKES. FINALLY...DID ADD A MENTION OF
FREEZING DRIZZLE OVER THE SOUTH CENTRAL FOR THIS MORNING WITH THE
MID LEVEL DRYING SEEN ON WV IMAGERY REMOVING ICE CRYSTALS IN THE
CLOUD FOR A PERIOD. KGRB REPORTED FREEZING RAIN FOR A PERIOD AS THAT
MOVED THROUGH THAT AREA AND SEEING BR AT KIMT. THINK THIS WILL BE
SHORT LIVED AS THE DEEPER MOISTURE ARRIVES FROM THE UPPER LOW.
THE OTHER FACTOR FOR SNOW OVER THE KEWEENAW AND NORTH CENTRAL TODAY
AND NORTH WIND BELTS IN THE WEST/CENTRAL TONIGHT WILL BE LAKE
ENHANCEMENT. DEEP MOISTURE...CYCLONIC FLOW AND 850MB TEMPS TO AROUND
-11C AND 800MB TEMPS OF -15C WILL LEAD TO ENOUGH INSTABILITY FOR
LAKE ENHANCEMENT AND THE LOCATION/TIMING COMES DOWN TO THE WINDS AND
HOW THEY SLOWLY BACK TODAY INTO TONIGHT. WITH THOSE
TEMPERATURES...LAKE INDUCED CAPES ARE NOT OVERLY
IMPRESSIVE...GENERALLY IN THE 100-200 J/KG RANGE...SO WOULDN/T
EXPECT THE LAKE ENHANCEMENT TO GET TOO OUT OF HAND. IT WILL PROBABLY
BE MORE OF A COMBINED EFFORT BETWEEN THE LAKE ENHANCEMENT AND THE
TERRAIN ENHANCEMENT AS THE WINDS BACK NORTHEAST THIS AFTERNOON
AND NORTHERLY INTO TONIGHT. PROBABLY THE BEST LOCATION FOR THOSE
COMBINED FACTORS WILL BE OVER THE HIGHER TERRAIN OF NORTHERN
MARQUETTE/BARAGA COUNTIES...ESPECIALLY SINCE THE WINDS WILL BE A
SLIGHTLY UNFAVORABLE NORTHEAST WIND DIRECTION FOR THE KEWEENAW LATE
THIS AFTERNOON AND TONIGHT. FARTHER EAST...WINDS WILL BE MORE
VARIABLE OVER ALGER/LUCE THIS AFTERNOON AND EVENING AFTER THE
INITIAL PUSH OF SNOW MOVES NORTH. SO THEY WILL LIKELY SEE A LULL
UNTIL THE ENHANCEMENT INCREASES OVERNIGHT AS THE WINDS TURN MORE
NORTH-NORTHWEST.
HAVE MADE SOME MINOR ADJUSTMENTS FOR SNOWFALL AMOUNTS AND TIMING
FOR TODAY...BUT THE GENERAL IDEA FOR THE FORECAST IS SIMILAR. SNOW
RATIOS WILL BE AROUND 10-12 TO 1 TODAY AND THEN TRANSITIONING
TOWARDS 15-20 TO 1 TONIGHT AS COLDER AND ARRIVES AND BETTER FORCING
IS WITHIN THE DGZ. HAVE THE HIGHEST AMOUNTS THIS MORNING OVER THE
EAST...THE HIGHER TERRAIN OF MARQUETTE COUNTY AND KEWEENAW WITH THE
INITIAL HEAVIER BATCH MOVING THROUGH. THEN THIS AFTERNOON...IT WILL
LIKELY BE FOCUSED MORE OVER THE KEWEENAW AND HIGHER TERRAIN OF
MARQUETTE/BARAGA AS WINDS SHIFT MORE NORTHWEST. THOSE AREAS WILL
PROBABLY SEE 2-5IN OF ADDITIONAL ACCUMULATION DURING THE DAY AND
1-4 TONIGHT. ELSEWHERE...1-4 INCH AMOUNTS ARE EXPECTED TODAY.
WILL LEAVE HEADLINES AS IS AT THIS TIME. DID EXTEND
ONTONAGON/GOGEBIC INTO TONIGHT WITH THE LAKE ENHANCEMENT AND LOW END
ADVISORY AMOUNTS. ONCE MUCH OF THE HEAVIER SNOW SHIFTS TO THE NORTH
THIS MORNING...MAY HAVE TO THINK ABOUT A TRANSITION TO MORE
ADVISORIES VS WARNINGS BASED OFF EXPECTED SNOWFALL AMOUNTS...BUT
THAT IS PROBABLY MORE SEMANTICS FOR THE GENERAL PUBLIC. PLUS...WITH
24 HOUR AMOUNTS APPROACHING WARNING TOTALS...IT MAY BE LESS
CONFUSING TO JUST KEEP THEM AS IS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 540 AM EDT FRI APR 12 2013
NAM SHOWS A CLOSED 500 MB LOW OVER THE U.P. NEAR MARQUETTE 12Z SAT.
THIS CLOSED LOW HEADS SLOWLY EAST THE NEAR SAULT STE MARIE 00Z SUN.
NEXT TROUGH THEN ARRIVES SUN NIGHT INTO MONDAY TO AFFECT THE AREA.
GFS...NAM AND ECMWF SHOW 850-500 MB Q-VECTOR CONVERGENCE MOVING IN
LATE SUN WHICH MOVES THROUGH SUN NIGHT ACROSS THE AREA. THIS NEXT
SYSTEM LOOKS TO HAVE SOME STRONG DYNAMICS WITH IT AS WELL ALONG WITH
PLENTY OF MOISTURE AND THINKING IS QPF WILL BE ANYWHERE FROM 0.60 TO
0.90 INCH ACROSS THE CWA FROM SUN AFTERNOON THROUGH SUN NIGHT. WE
STAY ON THE WARMER SIDE OF THIS SYSTEM WHICH MAKES IT TOUGHER TO
FORECAST PRECIPITATION. LOOKS LIKE PCPN WOULD START OFF AS SNOW SUN
AFTERNOON AND THEN WARMING WOULD OCCUR ALLOWING A RAIN/SNOW MIX SUN
NIGHT ACROSS ALL BUT THE FAR NORTH AND FAR WEST WHERE THE COLDER AIR
WOULD STAY...THEN GO TO RAIN ON MON. BECAUSE OF THIS...SNOW RATIOS
DO NOT LOOK VERY HIGH AND ANY SNOW THAT DOES FALL WOULD BE A HEAVY
AND WET SNOW. COULD SEE FROM SUN AFTERNOON THROUGH SUN NIGHT A TRACE
UP TO 4 INCHES ACROSS THE CWA WITH TRACE AMOUNTS ACROSS THE FAR
SOUTH TO 4 INCHES IN THE TIP OF THE KEWEENAW WITH MOST OF THE CWA
ANYWHERE FROM A TRACE TO 1.5 INCHES. MAIN PROBLEM IS GOING TO BE THE
QPF THOUGH AND MOST OF THIS RAIN WILL GET SOAKED INTO THE SNOWCOVER.
WITH PLENTY OF MOISTURE AROUND...WENT CATEGORICAL POPS SUN AFTERNOON
INTO SUN NIGHT FOR THE CWA. DID KEEP IT DRY FOR SUN MORNING THOUGH.
BEFORE THAT...COULD GET A LITTLE LAKE ENHANCEMENT PCPN FOR SAT NIGHT
AS 850 MB TEMPERATURES ARE AROUND -8C OR SO AND THE WRAPAROUND
MOISTURE DOES MOVE OUT THEN. DID NOT MAKE TOO MANY CHANGES TO THE
GOING FORECAST FOR TEMPERATURES OR WEATHER. WILL NOT GET TOO FANCY
ON WEATHER TYPES EITHER AND A RAIN/SNOW MIX FOR SUN AFTERNOON
THROUGH SUN NIGHT LOOKS GOOD.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB CLOSED LOW OVER
NORTHERN MN 12Z MON WITH A SHORTWAVE RIDGE OVER THE EASTERN U.S.
AND A BROAD 500 MB TROUGH OVER THE WESTERN U.S. THE CLOSED 500 MB
LOW HEADS NORTHEASTWARD ON TUE WITH A DIGGING TROUGH IN THE WESTERN
U.S. THIS TROUGH CONTINUES TO HEAD SLOWLY EAST 12Z WED INTO THE
ROCKIES AND THE TROUGH MOVES INTO THE NORTHERN PLAINS 12Z THU.
PATTERN CONTINUES TO LOOK COLD AND ACTIVE WITH TEMPERATURES BELOW
NORMAL WITH ABOVE NORMAL PRECIPITATION THIS EXTENDED FORECAST
PERIOD. LOOKS LIKE ANOTHER BIG STORM FOR WED NIGHT INTO THU AND POPS
ARE HIGHER DURING THAT TIME PERIOD FOR THIS. RAIN/SNOW MIX LOOKS TO
HAPPEN AT THAT TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 150 PM EDT FRI APR 12 2013
EXPECT SCATTERED TO NUMEROUS SNOW SHOWERS THIS AFTERNOON INTO THIS
EVENING WITH VARIABLE VISIBILITIES WILL LIKELY BE BOUNCING BETWEEN 1
AND 4 MILES. FROM THIS AFTERNOON INTO THIS EVENING...LAKE
INFLUENCES WILL ENHANCE THE SNOW AT KCMX/KSAW AT TIMES. AS THE UPPER
LOW IS OVERHEAD AND THE SURFACE LOW MOVES NORTHEAST INTO
CANADA...WINDS WILL TURN MORE NORTHERLY TONIGHT AND LEAD MAINLY LAKE
ENHANCED SNOWFALL FOR ALL THREE SITES. VISIBILITIES WERE KEPT DOWN
DURING THAT PERIOD AND ALSO LOWERED CEILINGS DUE TO WINDS BECOMING
MORE FAVORABLE TO UPSLOPE. THE SNOW SHOULD TAPER OFF SATURDAY BUT
WILL LIKELY REMAIN IN THE LOWER MVFR RANGE INTO THE EARLY AFTERNOON.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 540 AM EDT FRI APR 12 2013
A LOW PRESSURE SYSTEM MOVING THROUGH THE GREAT LAKES REGION TODAY
WILL CONTINUE TO PRODUCE GALE FORCE GUSTS TO 35-40KTS THROUGH THIS
THIS AFTERNOON BEFORE THE PRESSURE GRADIENT BEGINS TO WEAKEN LATE
THIS AFTERNOON AND EVENING AS THE LOW MOVES INTO WESTERN QUEBEC BY
SUNDAY MORNING. WHILE THIS OCCURS...WINDS WILL GRADUALLY SHIFT TO
THE NORTH-NORTHWEST THROUGH SATURDAY AS A LINGERING SURFACE TROUGH
ROTATES THROUGH LAKE SUPERIOR. HIGH PRESSURE WILL KEEP WINDS LIGHT
FOR SATURDAY NIGHT AND SUNDAY MORNING...BUT ANOTHER LOW PRESSURE
SYSTEM APPROACHING THE UPPER GREAT LAKES FROM THE NORTHERN PLAINS
WILL BRING INCREASING EASTERLY WINDS SUNDAY AFTERNOON INTO SUNDAY
NIGHT. A FEW GALES TO 35KTS ARE POSSIBLE ON SUNDAY NIGHT OVER THE
EASTERN LAKE. THIS LOW WILL SHIFT NORTHEAST TO JAMES BAY ON MONDAY
NIGHT AND EVENTUALLY SHIFT WINDS AROUND TO THE NORTHWEST ON MONDAY
NIGHT INTO TUESDAY. LARGE HIGH PRESSURE IN SOUTHERN CANADA WILL
BRING DECREASING WINDS TO THE AREA INTO WEDNESDAY...AS A RIDGE MOVES
INTO THE UPPER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 11 AM EDT SATURDAY FOR MIZ001-003.
WINTER WEATHER ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR MIZ010-
011.
WINTER WEATHER ADVISORY UNTIL 8 AM EDT /7 AM CDT/ SATURDAY FOR
MIZ002-009.
WINTER WEATHER ADVISORY UNTIL 2 PM EDT SATURDAY FOR MIZ004-005.
WINTER WEATHER ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ084.
LAKE SUPERIOR...
GALE WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR LSZ243>248-265-
267.
GALE WARNING UNTIL 5 PM EDT /4 PM CDT/ THIS AFTERNOON FOR LSZ162-
263-264-266.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLB
SHORT TERM...SRF
LONG TERM...07
AVIATION...JLB
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1244 PM EDT FRI APR 12 2013
.UPDATE...
ISSUED AT 1243 PM EDT FRI APR 12 2013
WV IMAGERY AND RUC ANALYSIS INDICATED THAT THE MID/UPPER LEVEL LOW
HAVE MOVED INTO CNTRL WI. ONE SHORTWAVE SPOKE WAS LIFTING THROUGH NW
UPPER MI SUPPORTED LIGHT TO MODERATE SNOW WHILE FORCING CLOSER TO
THE LOW HAS KEPT -SN GOING FROM NRN WI INTO SRN WI WITH VSBY INTO
THE 1SM TO 3SM RANGE. RADAR INDICATED THAT THE SNOW OVER THE ERN
CWA HAD DIMINISHED. ADDITIONAL ACCUMULATIONS OF ONLY AROUND AN INCH
ARE EXPECTED OVER THE SOUTH AND LESS THAN AN INCH OVER THE EAST.
SO...THE WINTER STORM WARNINGS WERE DROPPED OVER THE EAST AND THE
ADVISORY FOR DICKINSON/IRON WILL BE ALLOWED TO EXPIRE AT 18Z. THE
WARNINGS OVER FROM MARQUETTE INTO THE KEWEENAW WERE TRANSITIONED TO
WINTER WEATHER ADVISORIES FOR A MORE PROLONGED PERIOD OF LIGHT TO
MODERATE SNOW INTO SATURDAY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 540 AM EDT FRI APR 12 2013
INITIAL BATCH OF HEAVY SNOW IS MOVING NORTH ACROSS NORTH CENTRAL AND
EASTERN UPPER MICHIGAN AT THIS TIME. THIS IS ASSOCIATED WITH THE
TROWAL FEATURE...SEEN ON 290-315K SFCS...THAT PIVOTS NORTHEAST AND
BEST FORCING SLIDES OFF TO THE EAST THIS MORNING INTO EARLY
AFTERNOON. WOULD EXPECT THE HEAVIEST SNOW TO OCCUR OVER THE NORTH
CENTRAL OVER THE NEXT COUPLE OF HOURS BEFORE THE DRIER MID LEVEL AIR
SEEN ON WATER VAPOR IMAGERY AND GAP BETWEEN THE UPPER LOW AND
INITIAL SHORTWAVE MOVES IN. FARTHER EAST...THERE IS A LITTLE MORE OF
A FETCH WITH THE CLOSER PROXIMITY TO THE DEEPER MOISTURE AXIS MOVING
THROUGH LOWER MICHIGAN AND WOULD EXPECT THE HEAVIER SNOW TO CONTINUE
LONGER INTO THE MORNING HOURS. BUT THEN WITH THE DRIER AIR MOVING IN
BY LATE MORNING...THE SNOW SHOULD QUICKLY DIMINISH FROM SOUTH TO
NORTH THIS AFTERNOON.
TODAY WILL START THE TRANSITION TO A MORE GENERAL LIGHTER SNOW
ACROSS THE CWA...AS THE HEAVIER SNOW SHIFTS TO THE NORTHEAST. THE
UPPER LOW CURRENTLY OVER SOUTHEAST MN AND NORTHEAST IOWA IS EXPECTED
TO ROTATE NORTHEAST AND OVER THE UPPER GREAT LAKES THIS AFTERNOON
AND TONIGHT. EVEN WITH THE TROWAL FEATURE SHIFTING OUT EARLY THIS
MORNING...BROAD 850-500MB Q-VECTOR CONVERGENCE OVER THE AREA THIS
MORNING AHEAD OF THE SHORTWAVE ENERGY MOVING NORTH THROUGH CENTRAL
WISCONSIN SHOULD STILL LEAD TO LIGHT TO OCCASIONALLY MODERATE
SNOWFALL BEHIND THE HEAVIER SNOW. THIS Q-VECTOR CONVERGENCE STAYS
OVER THE NORTHERN HALF OF THE CWA THROUGH THIS AFTERNOON AND
TONIGHT. FARTHER SOUTH...THE LINE OF CONVECTIVE LOOKING SHOWERS ON
THE NORTH SIDE OF THE SHORTWAVE MOVING NORTH THROUGH WISCONSIN
SHOULD GRADUALLY SHIFT NORTH THROUGH THE DAY AND COULD LEAD TO BRIEF
HEAVIER SNOW SHOWERS OVER SOUTHERN UPPER MICHIGAN...ESPECIALLY SINCE
IT LOOKS TO COMBINE DEFORMATION AREA ON THE NW SIDE OF THE LOW
MOVING INTO THE LOWER GREAT LAKES. FINALLY...DID ADD A MENTION OF
FREEZING DRIZZLE OVER THE SOUTH CENTRAL FOR THIS MORNING WITH THE
MID LEVEL DRYING SEEN ON WV IMAGERY REMOVING ICE CRYSTALS IN THE
CLOUD FOR A PERIOD. KGRB REPORTED FREEZING RAIN FOR A PERIOD AS THAT
MOVED THROUGH THAT AREA AND SEEING BR AT KIMT. THINK THIS WILL BE
SHORT LIVED AS THE DEEPER MOISTURE ARRIVES FROM THE UPPER LOW.
THE OTHER FACTOR FOR SNOW OVER THE KEWEENAW AND NORTH CENTRAL TODAY
AND NORTH WIND BELTS IN THE WEST/CENTRAL TONIGHT WILL BE LAKE
ENHANCEMENT. DEEP MOISTURE...CYCLONIC FLOW AND 850MB TEMPS TO AROUND
-11C AND 800MB TEMPS OF -15C WILL LEAD TO ENOUGH INSTABILITY FOR
LAKE ENHANCEMENT AND THE LOCATION/TIMING COMES DOWN TO THE WINDS AND
HOW THEY SLOWLY BACK TODAY INTO TONIGHT. WITH THOSE
TEMPERATURES...LAKE INDUCED CAPES ARE NOT OVERLY
IMPRESSIVE...GENERALLY IN THE 100-200 J/KG RANGE...SO WOULDN/T
EXPECT THE LAKE ENHANCEMENT TO GET TOO OUT OF HAND. IT WILL PROBABLY
BE MORE OF A COMBINED EFFORT BETWEEN THE LAKE ENHANCEMENT AND THE
TERRAIN ENHANCEMENT AS THE WINDS BACK NORTHEAST THIS AFTERNOON
AND NORTHERLY INTO TONIGHT. PROBABLY THE BEST LOCATION FOR THOSE
COMBINED FACTORS WILL BE OVER THE HIGHER TERRAIN OF NORTHERN
MARQUETTE/BARAGA COUNTIES...ESPECIALLY SINCE THE WINDS WILL BE A
SLIGHTLY UNFAVORABLE NORTHEAST WIND DIRECTION FOR THE KEWEENAW LATE
THIS AFTERNOON AND TONIGHT. FARTHER EAST...WINDS WILL BE MORE
VARIABLE OVER ALGER/LUCE THIS AFTERNOON AND EVENING AFTER THE
INITIAL PUSH OF SNOW MOVES NORTH. SO THEY WILL LIKELY SEE A LULL
UNTIL THE ENHANCEMENT INCREASES OVERNIGHT AS THE WINDS TURN MORE
NORTH-NORTHWEST.
HAVE MADE SOME MINOR ADJUSTMENTS FOR SNOWFALL AMOUNTS AND TIMING
FOR TODAY...BUT THE GENERAL IDEA FOR THE FORECAST IS SIMILAR. SNOW
RATIOS WILL BE AROUND 10-12 TO 1 TODAY AND THEN TRANSITIONING
TOWARDS 15-20 TO 1 TONIGHT AS COLDER AND ARRIVES AND BETTER FORCING
IS WITHIN THE DGZ. HAVE THE HIGHEST AMOUNTS THIS MORNING OVER THE
EAST...THE HIGHER TERRAIN OF MARQUETTE COUNTY AND KEWEENAW WITH THE
INITIAL HEAVIER BATCH MOVING THROUGH. THEN THIS AFTERNOON...IT WILL
LIKELY BE FOCUSED MORE OVER THE KEWEENAW AND HIGHER TERRAIN OF
MARQUETTE/BARAGA AS WINDS SHIFT MORE NORTHWEST. THOSE AREAS WILL
PROBABLY SEE 2-5IN OF ADDITIONAL ACCUMULATION DURING THE DAY AND
1-4 TONIGHT. ELSEWHERE...1-4 INCH AMOUNTS ARE EXPECTED TODAY.
WILL LEAVE HEADLINES AS IS AT THIS TIME. DID EXTEND
ONTONAGON/GOGEBIC INTO TONIGHT WITH THE LAKE ENHANCEMENT AND LOW END
ADVISORY AMOUNTS. ONCE MUCH OF THE HEAVIER SNOW SHIFTS TO THE NORTH
THIS MORNING...MAY HAVE TO THINK ABOUT A TRANSITION TO MORE
ADVISORIES VS WARNINGS BASED OFF EXPECTED SNOWFALL AMOUNTS...BUT
THAT IS PROBABLY MORE SEMANTICS FOR THE GENERAL PUBLIC. PLUS...WITH
24 HOUR AMOUNTS APPROACHING WARNING TOTALS...IT MAY BE LESS
CONFUSING TO JUST KEEP THEM AS IS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 540 AM EDT FRI APR 12 2013
NAM SHOWS A CLOSED 500 MB LOW OVER THE U.P. NEAR MARQUETTE 12Z SAT.
THIS CLOSED LOW HEADS SLOWLY EAST THE NEAR SAULT STE MARIE 00Z SUN.
NEXT TROUGH THEN ARRIVES SUN NIGHT INTO MONDAY TO AFFECT THE AREA.
GFS...NAM AND ECMWF SHOW 850-500 MB Q-VECTOR CONVERGENCE MOVING IN
LATE SUN WHICH MOVES THROUGH SUN NIGHT ACROSS THE AREA. THIS NEXT
SYSTEM LOOKS TO HAVE SOME STRONG DYNAMICS WITH IT AS WELL ALONG WITH
PLENTY OF MOISTURE AND THINKING IS QPF WILL BE ANYWHERE FROM 0.60 TO
0.90 INCH ACROSS THE CWA FROM SUN AFTERNOON THROUGH SUN NIGHT. WE
STAY ON THE WARMER SIDE OF THIS SYSTEM WHICH MAKES IT TOUGHER TO
FORECAST PRECIPITATION. LOOKS LIKE PCPN WOULD START OFF AS SNOW SUN
AFTERNOON AND THEN WARMING WOULD OCCUR ALLOWING A RAIN/SNOW MIX SUN
NIGHT ACROSS ALL BUT THE FAR NORTH AND FAR WEST WHERE THE COLDER AIR
WOULD STAY...THEN GO TO RAIN ON MON. BECAUSE OF THIS...SNOW RATIOS
DO NOT LOOK VERY HIGH AND ANY SNOW THAT DOES FALL WOULD BE A HEAVY
AND WET SNOW. COULD SEE FROM SUN AFTERNOON THROUGH SUN NIGHT A TRACE
UP TO 4 INCHES ACROSS THE CWA WITH TRACE AMOUNTS ACROSS THE FAR
SOUTH TO 4 INCHES IN THE TIP OF THE KEWEENAW WITH MOST OF THE CWA
ANYWHERE FROM A TRACE TO 1.5 INCHES. MAIN PROBLEM IS GOING TO BE THE
QPF THOUGH AND MOST OF THIS RAIN WILL GET SOAKED INTO THE SNOWCOVER.
WITH PLENTY OF MOISTURE AROUND...WENT CATEGORICAL POPS SUN AFTERNOON
INTO SUN NIGHT FOR THE CWA. DID KEEP IT DRY FOR SUN MORNING THOUGH.
BEFORE THAT...COULD GET A LITTLE LAKE ENHANCEMENT PCPN FOR SAT NIGHT
AS 850 MB TEMPERATURES ARE AROUND -8C OR SO AND THE WRAPAROUND
MOISTURE DOES MOVE OUT THEN. DID NOT MAKE TOO MANY CHANGES TO THE
GOING FORECAST FOR TEMPERATURES OR WEATHER. WILL NOT GET TOO FANCY
ON WEATHER TYPES EITHER AND A RAIN/SNOW MIX FOR SUN AFTERNOON
THROUGH SUN NIGHT LOOKS GOOD.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB CLOSED LOW OVER
NORTHERN MN 12Z MON WITH A SHORTWAVE RIDGE OVER THE EASTERN U.S.
AND A BROAD 500 MB TROUGH OVER THE WESTERN U.S. THE CLOSED 500 MB
LOW HEADS NORTHEASTWARD ON TUE WITH A DIGGING TROUGH IN THE WESTERN
U.S. THIS TROUGH CONTINUES TO HEAD SLOWLY EAST 12Z WED INTO THE
ROCKIES AND THE TROUGH MOVES INTO THE NORTHERN PLAINS 12Z THU.
PATTERN CONTINUES TO LOOK COLD AND ACTIVE WITH TEMPERATURES BELOW
NORMAL WITH ABOVE NORMAL PRECIPITATION THIS EXTENDED FORECAST
PERIOD. LOOKS LIKE ANOTHER BIG STORM FOR WED NIGHT INTO THU AND POPS
ARE HIGHER DURING THAT TIME PERIOD FOR THIS. RAIN/SNOW MIX LOOKS TO
HAPPEN AT THAT TIME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 751 AM EDT FRI APR 12 2013
THE VERY HEAVY SNOW THAT MOVED THROUGH OVERNIGHT HAS SHIFTED NORTH
OF THE TAF SITES AND NOW ALL OF THEM WILL BE INFLUENCED BY THE UPPER
LOW ROTATING NORTH FROM WISCONSIN. THIS WILL LIKELY LEAD TO
SCATTERED TO NUMEROUS SNOW SHOWERS THROUGH THE DAY AND BASED ON
UPSTREAM OBS...VISIBILITIES WILL LIKELY BE BOUNCING BETWEEN 1 AND 5
MILES WITH THE SHOWERS. AS THE DAY GOES ON...LAKE INFLUENCES WILL
ENHANCE THE SNOW AT KCMX/KSAW AT TIMES. AS THE UPPER LOW IS OVERHEAD
AND THE SURFACE LOW MOVES NORTHEAST INTO CANADA...WINDS WILL TURN
MORE NORTHERLY TONIGHT AND LEAD MAINLY LAKE ENHANCED SNOWFALL FOR
ALL THREE SITES. HAVE CONTINUED TO KEEP VISIBILITIES DOWN DURING
THAT PERIOD AND ALSO LOWERED CEILINGS DUE TO WINDS BECOMING MORE
FAVORABLE TO UPSLOPE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 540 AM EDT FRI APR 12 2013
A LOW PRESSURE SYSTEM MOVING THROUGH THE GREAT LAKES REGION TODAY
WILL CONTINUE TO PRODUCE GALE FORCE GUSTS TO 35-40KTS THROUGH THIS
THIS AFTERNOON BEFORE THE PRESSURE GRADIENT BEGINS TO WEAKEN LATE
THIS AFTERNOON AND EVENING AS THE LOW MOVES INTO WESTERN QUEBEC BY
SUNDAY MORNING. WHILE THIS OCCURS...WINDS WILL GRADUALLY SHIFT TO
THE NORTH-NORTHWEST THROUGH SATURDAY AS A LINGERING SURFACE TROUGH
ROTATES THROUGH LAKE SUPERIOR. HIGH PRESSURE WILL KEEP WINDS LIGHT
FOR SATURDAY NIGHT AND SUNDAY MORNING...BUT ANOTHER LOW PRESSURE
SYSTEM APPROACHING THE UPPER GREAT LAKES FROM THE NORTHERN PLAINS
WILL BRING INCREASING EASTERLY WINDS SUNDAY AFTERNOON INTO SUNDAY
NIGHT. A FEW GALES TO 35KTS ARE POSSIBLE ON SUNDAY NIGHT OVER THE
EASTERN LAKE. THIS LOW WILL SHIFT NORTHEAST TO JAMES BAY ON MONDAY
NIGHT AND EVENTUALLY SHIFT WINDS AROUND TO THE NORTHWEST ON MONDAY
NIGHT INTO TUESDAY. LARGE HIGH PRESSURE IN SOUTHERN CANADA WILL
BRING DECREASING WINDS TO THE AREA INTO WEDNESDAY...AS A RIDGE MOVES
INTO THE UPPER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 11 AM EDT SATURDAY FOR MIZ001-003.
WINTER WEATHER ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR MIZ010-
011.
WINTER WEATHER ADVISORY UNTIL 8 AM EDT /7 AM CDT/ SATURDAY FOR
MIZ002-009.
WINTER WEATHER ADVISORY UNTIL 2 PM EDT SATURDAY FOR MIZ004-005.
WINTER WEATHER ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ084.
LAKE SUPERIOR...
GALE WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR LSZ243>248-265-
267.
GALE WARNING UNTIL 5 PM EDT /4 PM CDT/ THIS AFTERNOON FOR LSZ162-
263-264-266.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLB
SHORT TERM...SRF
LONG TERM...07
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1023 AM EDT FRI APR 12 2013
.SYNOPSIS...
ISSUED AT 350 AM EDT FRI APR 12 2013
SLOW MOVING...LOW PRESSURE IS LIFTING INTO THE UPPER GREAT LAKES
REGION AND WILL BRING A WINTRY MESS OF PRECIPITATION TYPES TO
NORTHERN MICHIGAN TODAY. THE FREEZING RAIN AND SLEET IS EXPECTED TO
TRANSITION OVER TO SNOW AND DRIZZLE THIS MORNING. THIS WILL CONTINUE
INTO THE EVENING BEFORE CHANGING TO ALL SNOW TONIGHT. HIGH PRESSURE
TRIES TO SNOW INTO THE REGION ON SATURDAY SO THAT WE WILL GET A
BREAK FOR THE WEEKEND.
&&
.UPDATE...
ISSUED AT 1022 AM EDT FRI APR 12 2013
MAIN BATCH OF "WARM CONVEYOR" PRECIP HAS LIFTED NORTH/EAST OUT OF
THE CWA THIS MORNING...WHILE MID LEVEL DRY SLOT HAS PUNCHED UP
INTO NRN MICHIGAN (EVIDENT ON KAPX VAD WIND PROFILE). MAINLY JUST
SOME FLURRIES/DRIZZLE/FREEZING DRIZZLE OCCURRING AT THE MOMENT.
MAIN MID LEVEL SHORT WAVE SLOWLY ADVANCING NORTHEASTWARD ACROSS
WISCONSIN AND IS PRODUCING SOME ADDITIONAL LIGHT PRECIP THAT WILL
LIKELY IMPACT PARTS OF NORTHWEST LOWER AND EASTERN UPPER MICHIGAN
AS WE GO THROUGH THE AFTERNOON/EARLY EVENING. BUT OTHERWISE...MAIN
BATCH OF PRECIP IS DONE AND WINDS ARE WEAKENING. SO...WILL CANCEL
THE WINTER STORM WARNING FOR EASTERN UPPER MICHIGAN AHEAD OF
SCHEDULE.
UPDATE
ISSUED AT 712 AM EDT FRI APR 12 2013
ONGOING FORECAST IS PORTRAYING THE SCENE OUTSIDE PRETTY WELL. MAIN
SWATH OF PRECIPITATION IS WRAPPED FROM NE LOWER ACROSS EASTERN
UPPER. WITH COOLING OCCURRING THROUGHOUT THE ATMOSPHERE NOW...MOST
ALL AREAS HAVE SWITCHED OVER TO SNOW...OR LIGHT SNOW AND DRIZZLY
CONDITIONS UNDERNEATH DEEPER MOISTURE PEELING OFF TO THE EAST.
LATEST SATELLITE AND UPSTREAM SFC OBS SHOWING THAT EVERYONE IS
LIKELY TO GET INTO A PERIOD OR TWO OF DRIZZLE/FREEZING DRIZZLE. THE
WORST OF IT IS OVER NOW...AND WILL CANCEL THE WARNINGS FOR ALL BUT
EASTERN UPPER...WHERE SOME ADDITIONAL ACCUMULATIONS ARE
POSSIBLE...BUT EVEN HERE...DAY CREW MAY DECIDE TO END THE HEADLINES
BY LATE MORNING.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 350 AM EDT FRI APR 12 2013
CURRENTLY...POTENT UPPER LEVEL CLOSED LOW IS DRIFTING ACROSS THE
FAR NRN MISSISSIPPI VALLEY...WITH OCCLUDED LOW PRESSURE FROM THE
APPALACHIANS...AND TROUGHING/TROWAL EXTENDING BACK INTO SRN
WISCONSIN. MAIN H8-H7 WARM ADVECTION EXTENDS ALONG H8 WIND SPEED
MAX WHICH IS NOW EXTENDING FROM THE EASTERN GREAT LAKES BACK AROUND
THROUGH EASTERN UPPER MICHIGAN. THIS IS WHERE ONE SWATH OF BETTER
PRECIPITATION...IN THE FORM OF SNOW AND SOME SLEET...IS CO-LOCATED
WITH STRONG POCKET OF UPPER DIVERGENCE IN RIGHT ENTRANCE REGION OF
QUEBEC 120+KT UPPER JET. ANOTHER JET STREAK WAS CROSSING THE OHIO
RIVER VALLEY...AND ANOTHER POCKET OF UPPER DIVERGENCE IN LEFT EXIT
REGION OF WAS DEVELOPING ACROSS THE EASTERN GREAT LAKES. DPVA
AROUND THE CLOSED LOW ALOFT...COMBINED WITH THESE FORCING
MECHANISMS...HAS RESULTED IN MODEST TO STRONG DEEP LAYER LIFT AND
WIDESPREAD PRECIPITATION ACROSS MAINLY NE LOWER AND BACK AROUND
THROUGH EASTERN UPPER.
NOW...THERMALLY SPEAKING...WE HAVE GONE THROUGH QUITE ALONG PERIOD
OF SLEET AND FREEZING RAIN IN NRN LOWER...AS 00Z APX SOUNDING TELLS
THE STORY. 800-700MB DEEP 2-3C WARM NOSE IS EVIDENT...WITH A
COUNTERING DEEP SFC-800MB COLD LAYER WITH A MAXIMUM -6C READING AT
900MB...COLD ENOUGH TO RE-FREEZE TOTALLY MELTED DROPS FROM THAT 2-3C
DEEP WARM NOSE. ONE OF THE BETTER SLEET SOUNDINGS THIS FORECASTER
HAS SEEN. AS THE ENTIRE SYSTEM HAS BEEN SLOW TO TRANSITION NORTH AND
EAST WITH TIME...QUITE A BIT OF SLEET HAS BEEN ABLE TO FALL AND
ACCUMULATE. ACROSS EASTERN UPPER...SOME SLEET MAY BE TRYING TO MIX
WITH WHAT SHOULD BE PRIMARILY SNOW...BASED ON LATEST DUAL POL RADAR
LOOPING. RUC FCST SOUNDINGS ALSO SUGGEST ALL SNOW IN EASTERN
UPPER...WITH THE ELEVATED WARM COOLING STARTING AS OF THIS WRITING.
LATEST OBS SUGGESTING THAT THIS MAY BE TAKING PLACE NOW WITH MORE
OBSERVATIONS ACROSS THE WEST NOW LOOKING MORE "SNOWY" RATHER THAN
"ICY". ALSO IN THE MIX...IS THE CURRENT EFFORT FOR DEEPER MOISTURE
TO STRIP OUT ALOFT FROM THE WEST...WHICH ALLOWS US TO EXPERIENCE YET
ANOTHER PRECIPITATION TYPE...DRIZZLE AND FREEZING DRIZZLE.
IT SHOULD BE WORTH NOTING THAT NOT ALL FOLKS HAVE EXPERIENCED THIS
PLETHORA OF NASTY WINTRY WEATHER. DOWNSLOPING REGIONS ACROSS NW
LOWER...MAINLY FRANKFORT AND MANISTEE AREAS...WERE ABOVE FREEZING
FOR MUCH OF THE NIGHT...SO NOT FREEZING RAIN THERE.
IN THE SPIRIT OF A FORMER NWS COLLEAGUE..."WELL...AT LEAST IT`S
WINDY". YEAH...EAST WINDS WERE GUSTING AS HIGH AS 35-40 MPH MUCH OF
THE NIGHT TOO.
NOW...THE FORECAST...POTENT UPPER LOW WILL LIFT INTO EASTERN LAKE
SUPERIOR TODAY AND TONIGHT...WITH THE SFC TROUGHING/TROWAL AND
AXIS OF DEEPER MOISTURE AND FORCING LIFTING NORTH AND EAST
THROUGH THE MORNING. COLDER AIR SEEPS IN...AND THE TRANSITION OVER
TO MAINLY LIGHT SNOW WILL BE JOINED BY DRIZZLE AND FREEZING
DRIZZLE DUE TO DRYING ALOFT. THE THERMAL PROFILES BECOME AN
INCREASINGLY LIGHT SNOW/DRIZZLE LOOK...AS MOISTURE WILL BE AT OR
BELOW 10C FOR MOST OF THE DAY AND EVEN INTO THE EVENING. THE BEST
MOISTURE/FORCING WILL BE ACROSS CHIPPEWA COUNTY FOR THE LONGEST
PERIOD OF TIME. HERE...ALTHOUGH TOTAL QPF/SNOWFALL WERE LOWERED
SLIGHTLY...WILL STILL SEE A GRAND TOTAL OF 4 TO 8 INCHES BY THE
END OF THE DAY. LESSER AMOUNTS HEADING SOUTH UNTIL JUST AN INCH
DOWN NEAR THE M-55 CORRIDOR. CURRENT WINTER STORM HEADLINES WILL
HOLD TRUE...ENDING FROM SOUTH TO NORTH THROUGH THE DAY. LIGHT
SNOWS AND DRIZZLE ARE LIKELY AT LEAST INTO THE EVENING DUE TO THE
LOW LEVEL CONVERGENCE ASSOCIATED WITH THE ACTUAL SFC TROUGHING.
EVENTUALLY BY LATER TONIGHT...THE LOW LEVEL TROUGHING
WEAKENS/DEPARTS...WITH THE ENTIRE ATMOSPHERIC COLUMN COLD ENOUGH
FOR JUST SNOW. CAN MAKE A REAL GOOD ARGUMENT FOR LIKELY SNOWS FOR
MOST EVERYONE AT SOME POINT DURING THE NIGHT. THIS DUE NOT ONLY TO
THE LINGERING TROUGHING AT THE SFC...BUT ALSO WITH MID LEVEL
TROUGHING WITH THE UPPER CIRCULATIONS...WHICH WILL BE ALIGNED
ACROSS EASTERN UPPER. THUS...WILL HAVE THE BETTER ACCUMULATIONS
AND CHANCES FOR SNOW THERE. MAYBE ANOTHER INCH ACROSS EASTERN
UPPER...WITH LESSER AMOUNTS HEADING FURTHER SOUTH.
CLOUDY THROUGH THE PERIOD WITH LITTLE DIURNAL SWINGS IN
TEMPERATURE. HIGHS IN THE 30S TODAY...WITH LOWS IN THE MIDDLE 20S
TO LOWER 30S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 350 AM EDT FRI APR 12 2013
SATURDAY...AS THE 500 MB LOW DRIFTS EAST JUST NORTH OF THE FORECAST
AREA, THERE WILL BE ENOUGH FORCING TO CONTINUE THE SNOW SHOWERS.
HOWEVER, THE KICKER IS THAT THE 850 MB TEMPERATURES FALL TO AROUND
-10C AND WITH THE WATER TEMPERATURES SLIGHTLY WARMER AROUND +1 TO
+2C WE WILL PROBABLY GET SOME ENHANCEMENT ESPECIALLY NEARER THE SFC
AND 500 MB LOWS. SO WILL HAVE AN AREA OF LIKELY POPS IN E UPPER AND
ENHANCED CHANCE POPS IN NW LOWER. BY 00Z, THINGS BEGIN TO LOOK LIKE
LAKE EFFECT, HOWEVER, THE PROBLEM IS THAT THE 850 MB TEMPERATURES
BEGIN TO WARM BIT, AND WE LOSE THE ENHANCEMENT.
SATURDAY NIGHT...WE LOSE GOOD 850 MB AND SFC FLOW AS THE
TEMPERATURES RISE TO AROUND -8C. WILL ALLOW FOR SOME FLURRIES EARLY,
BUT ALL THINGS BEING EQUAL, THINK THAT THE WITH THE DRIER AIR MOVING
IN AS WELL, THAT THE SNOW WILL STOP SHORTLY HAVE 00Z.
SUNDAY...THE NEXT SYSTEM BEGINS TO LIFT NORTH INTO NORTHERN PLAINS.
THE GFS HAS IT A LITTLE MORE EAST IN MINNESOTA, WHILE THE 00Z ECMWF
HAS IT IN E NORTH DAKOTA. THE DIFFERENCE IS THAT THE GFS BRINGS
CHANCE POPS INTO NW LOWER SOONER. WITH THESE SYSTEMS BEING KIND OF
ALL OVER THE PLACE, IN THE RUN UP TO THEM, WILL HEDGE BETWEEN THE
TWO. SO CUT THE POPS BACK SO THAT NW LOWER HAVE SOME CHANCE POPS,
AND THE REST OF THE REGION IS RELATIVELY DRY. OVERNIGHT, THE WARM
FRONT IN EITHER CASE MAKES IT FAR ENOUGH NORTH RAIN TAKES OVER IN E
UPPER. THE FRONT STALLS THERE AS WELL SO THAT THE SFC LOW RIDES UP
INTO LAKE SUPERIOR ALONG IT. SO RAIN WILL BE EXPECTED IN E UPPER AND
WITH THE WARM SECTOR MOVING NORTH WILL HAVE LESS CHANCES TO THE
SOUTH.
EXTENDED (MONDAY THROUGH THURSDAY)...MONDAY, EXPECTING RAIN FROM THE
SYSTEM MOVING THROUGH DURING THE DAY. OVERNIGHT, WITH THE FRONT
THROUGH AND THE SFC LOW TO THE EAST, WILL EXPECT THAT E UPPER AND
PORTIONS OF N LOWER WILL CLEAR OUT AS HIGH PRESSURE BUILDS INTO THE
REGION. TUESDAY, THE FRONT HOLDS TO THE EAST WITH HIGH PRESSURE
NOSING INTO LOWER MICHIGAN. LOOKS LIKE SOME RAIN COULD HOLD ON WITH
WAVES RUNNING UP THE FRONT. SO WILL ALLOW FOR SOME RAIN IN NE
LOWER. WEDNESDAY, THE NEXT SYSTEM BEGINS TO PUSH OUT OF THE SOUTHERN
PLAINS AND BY THE TIME THAT IT GETS INTO THE MID-MISSISSIPPI VALLEY,
THE RAIN WILL SPREAD BACK NORTH THROUGH N LOWER AND IN E UPPER,
WHERE A MIX WILL BE EXPECTED. OF COURSE, THE WARM AIR WILL CONTINUE
NORTH CHANGING THE SNOW BACK TO RAIN OVERNIGHT. THURSDAY, THE MODELS
HAVE TWO DIFFERENT TRACKS. THE ECMWF STILL BRINGS THE SFC LOW OVER N
LOWER, WHICH WOULD BRING MORE RAIN TO THE REGION BEFORE CHANGING TO
SNOW THURSDAY NIGHT. THE GFS BRINGS THE SFC LOW UP THROUGH LAKE
ERIE. THIS WOULD BRING SNOW OR RAIN AND SNOW TO N LOWER AND E UPPER.
DECIDED TO PLAY AS RAIN THURSDAY, RAIN/SNOW THURSDAY NIGHT FOR NOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 712 AM EDT FRI APR 12 2013
WIDESPREAD MVFR CIGS WILL PREVAIL THROUGHOUT THE TAF PERIOD WITH
LOADS OF LOW LEVEL MOISTURE SURROUNDING LOW PRESSURE LIFTING THROUGH
NRN MICHIGAN TODAY. MOISTURE IS QUICKLY PEELING OUT ALOFT EARLY IN
THE TAF PERIOD WHILE TEMPERATURES ARE COOLING THROUGHOUT THE
ATMOSPHERE. THIS IS RESULTING IN A TRANSITION TO A SCENARIO
CHARACTERIZED AS PERIODS OF LIGHT SNOW AND DRIZZLE/FREEZING DRIZZLE.
THIS WILL BE THE COMMON THEME INTO THE EVENING...BEFORE ONLY LIGHT
SNOW SHOWERS ARE GOING TO BE POSSIBLE FOR THE LATE NIGHT HOURS.
GUSTY EAST WINDS TO 30 MPH AT PLN/APN WILL DIE OFF THROUGH THE
DAY...JUST AS THEY DID ACROSS MBL AND TVC. THESE WINDS WILL
GRADUALLY BACK AROUND OUT OF THE NORTH AND ULTIMATELY THE WEST BY
SATURDAY MORNING...AS THE LOW PRESSURE EXITS FURTHER EAST.
&&
.MARINE...
ISSUED AT 350 AM EDT FRI APR 12 2013
GALE FORCE GUSTS ARE IN FULL EFFECT ACROSS MOST OF THE SURROUNDING
NEARSHORE WATERS OF LAKES HURON AND MICHIGAN...NORTH OF GRAND
TRAVERSE LIGHT AND STURGEON POINT LIGHT. NORTH OF THERE...SOLID
ADVISORY LEVEL GUSTS WERE ONGOING...WHILE SOUTH OF THE
GALES...WINDS WERE DROPPING OFF RATHER QUICKLY WITH A LOOSE
GRADIENT ALONG LOW PRESSURE LIFTING NORTHWARD. THIS LIGHTER
GRADIENT WILL GRADUALLY OVERTAKE ALL OF THE NEARSHORE WATERS
THROUGH THE DAY...WITH GALES GRADUALLY STEPPING DOWN INTO
ADVISORY...THEN SUB ADVISORY LEVELS. THE LOW PRESSURE LIFTS EAST
TONIGHT...WITH COLD ADVECTION AND WESTERLY WINDS DEVELOPING...BUT
EXPECTATIONS ARE FOR WINDS TO BE BELOW ADVISORY LEVELS THROUGH
EARLY SUNDAY. THE NEXT LOW PRESSURE SYSTEM IS SET FOR LATER SUNDAY
AND INTO MONDAY. ADDITIONAL HEADLINES MAY BE REQUIRED.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LHZ349.
GALE WARNING UNTIL 11 AM EDT THIS MORNING FOR LHZ345>348.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ323-341-
344.
GALE WARNING UNTIL 11 AM EDT THIS MORNING FOR LMZ342.
LS...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LSZ321-322.
&&
$$
UPDATE...BA
SYNOPSIS...JL
SHORT TERM...SD
LONG TERM...JL
AVIATION...SD
MARINE...SD
AREA FORECAST DISCUSSION
NWS GAYLORD MI
713 AM EDT FRI APR 12 2013
.SYNOPSIS...
ISSUED AT 350 AM EDT FRI APR 12 2013
SLOW MOVING...LOW PRESSURE IS LIFTING INTO THE UPPER GREAT LAKES
REGION AND WILL BRING A WINTRY MESS OF PRECIPITATION TYPES TO
NORTHERN MICHIGAN TODAY. THE FREEZING RAIN AND SLEET IS EXPECTED TO
TRANSITION OVER TO SNOW AND DRIZZLE THIS MORNING. THIS WILL CONTINUE
INTO THE EVENING BEFORE CHANGING TO ALL SNOW TONIGHT. HIGH PRESSURE
TRIES TO SNOW INTO THE REGION ON SATURDAY SO THAT WE WILL GET A
BREAK FOR THE WEEKEND.
&&
.UPDATE...
ISSUED AT 712 AM EDT FRI APR 12 2013
ONGOING FORECAST IS PORTRAYING THE SCENE OUTSIDE PRETTY WELL. MAIN
SWATH OF PRECIPITATION IS WRAPPED FROM NE LOWER ACROSS EASTERN
UPPER. WITH COOLING OCCURRING THROUGHOUT THE ATMOSPHERE NOW...MOST
ALL AREAS HAVE SWITCHED OVER TO SNOW...OR LIGHT SNOW AND DRIZZLY
CONDITIONS UNDERNEATH DEEPER MOISTURE PEELING OFF TO THE EAST.
LATEST SATELLITE AND UPSTREAM SFC OBS SHOWING THAT EVERYONE IS
LIKELY TO GET INTO A PERIOD OR TWO OF DRIZZLE/FREEZING DRIZZLE. THE
WORST OF IT IS OVER NOW...AND WILL CANCEL THE WARNINGS FOR ALL BUT
EASTERN UPPER...WHERE SOME ADDITIONAL ACCUMULATIONS ARE
POSSIBLE...BUT EVEN HERE...DAY CREW MAY DECIDE TO END THE HEADLINES
BY LATE MORNING.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 350 AM EDT FRI APR 12 2013
CURRENTLY...POTENT UPPER LEVEL CLOSED LOW IS DRIFTING ACROSS THE
FAR NRN MISSISSIPPI VALLEY...WITH OCCLUDED LOW PRESSURE FROM THE
APPALACHIANS...AND TROUGHING/TROWAL EXTENDING BACK INTO SRN
WISCONSIN. MAIN H8-H7 WARM ADVECTION EXTENDS ALONG H8 WIND SPEED
MAX WHICH IS NOW EXTENDING FROM THE EASTERN GREAT LAKES BACK AROUND
THROUGH EASTERN UPPER MICHIGAN. THIS IS WHERE ONE SWATH OF BETTER
PRECIPITATION...IN THE FORM OF SNOW AND SOME SLEET...IS CO-LOCATED
WITH STRONG POCKET OF UPPER DIVERGENCE IN RIGHT ENTRANCE REGION OF
QUEBEC 120+KT UPPER JET. ANOTHER JET STREAK WAS CROSSING THE OHIO
RIVER VALLEY...AND ANOTHER POCKET OF UPPER DIVERGENCE IN LEFT EXIT
REGION OF WAS DEVELOPING ACROSS THE EASTERN GREAT LAKES. DPVA
AROUND THE CLOSED LOW ALOFT...COMBINED WITH THESE FORCING
MECHANISMS...HAS RESULTED IN MODEST TO STRONG DEEP LAYER LIFT AND
WIDESPREAD PRECIPITATION ACROSS MAINLY NE LOWER AND BACK AROUND
THROUGH EASTERN UPPER.
NOW...THERMALLY SPEAKING...WE HAVE GONE THROUGH QUITE ALONG PERIOD
OF SLEET AND FREEZING RAIN IN NRN LOWER...AS 00Z APX SOUNDING TELLS
THE STORY. 800-700MB DEEP 2-3C WARM NOSE IS EVIDENT...WITH A
COUNTERING DEEP SFC-800MB COLD LAYER WITH A MAXIMUM -6C READING AT
900MB...COLD ENOUGH TO RE-FREEZE TOTALLY MELTED DROPS FROM THAT 2-3C
DEEP WARM NOSE. ONE OF THE BETTER SLEET SOUNDINGS THIS FORECASTER
HAS SEEN. AS THE ENTIRE SYSTEM HAS BEEN SLOW TO TRANSITION NORTH AND
EAST WITH TIME...QUITE A BIT OF SLEET HAS BEEN ABLE TO FALL AND
ACCUMULATE. ACROSS EASTERN UPPER...SOME SLEET MAY BE TRYING TO MIX
WITH WHAT SHOULD BE PRIMARILY SNOW...BASED ON LATEST DUAL POL RADAR
LOOPING. RUC FCST SOUNDINGS ALSO SUGGEST ALL SNOW IN EASTERN
UPPER...WITH THE ELEVATED WARM COOLING STARTING AS OF THIS WRITING.
LATEST OBS SUGGESTING THAT THIS MAY BE TAKING PLACE NOW WITH MORE
OBSERVATIONS ACROSS THE WEST NOW LOOKING MORE "SNOWY" RATHER THAN
"ICY". ALSO IN THE MIX...IS THE CURRENT EFFORT FOR DEEPER MOISTURE
TO STRIP OUT ALOFT FROM THE WEST...WHICH ALLOWS US TO EXPERIENCE YET
ANOTHER PRECIPITATION TYPE...DRIZZLE AND FREEZING DRIZZLE.
IT SHOULD BE WORTH NOTING THAT NOT ALL FOLKS HAVE EXPERIENCED THIS
PLETHORA OF NASTY WINTRY WEATHER. DOWNSLOPING REGIONS ACROSS NW
LOWER...MAINLY FRANKFORT AND MANISTEE AREAS...WERE ABOVE FREEZING
FOR MUCH OF THE NIGHT...SO NOT FREEZING RAIN THERE.
IN THE SPIRIT OF A FORMER NWS COLLEAGUE..."WELL...AT LEAST IT`S
WINDY". YEAH...EAST WINDS WERE GUSTING AS HIGH AS 35-40 MPH MUCH OF
THE NIGHT TOO.
NOW...THE FORECAST...POTENT UPPER LOW WILL LIFT INTO EASTERN LAKE
SUPERIOR TODAY AND TONIGHT...WITH THE SFC TROUGHING/TROWAL AND
AXIS OF DEEPER MOISTURE AND FORCING LIFTING NORTH AND EAST
THROUGH THE MORNING. COLDER AIR SEEPS IN...AND THE TRANSITION OVER
TO MAINLY LIGHT SNOW WILL BE JOINED BY DRIZZLE AND FREEZING
DRIZZLE DUE TO DRYING ALOFT. THE THERMAL PROFILES BECOME AN
INCREASINGLY LIGHT SNOW/DRIZZLE LOOK...AS MOISTURE WILL BE AT OR
BELOW 10C FOR MOST OF THE DAY AND EVEN INTO THE EVENING. THE BEST
MOISTURE/FORCING WILL BE ACROSS CHIPPEWA COUNTY FOR THE LONGEST
PERIOD OF TIME. HERE...ALTHOUGH TOTAL QPF/SNOWFALL WERE LOWERED
SLIGHTLY...WILL STILL SEE A GRAND TOTAL OF 4 TO 8 INCHES BY THE
END OF THE DAY. LESSER AMOUNTS HEADING SOUTH UNTIL JUST AN INCH
DOWN NEAR THE M-55 CORRIDOR. CURRENT WINTER STORM HEADLINES WILL
HOLD TRUE...ENDING FROM SOUTH TO NORTH THROUGH THE DAY. LIGHT
SNOWS AND DRIZZLE ARE LIKELY AT LEAST INTO THE EVENING DUE TO THE
LOW LEVEL CONVERGENCE ASSOCIATED WITH THE ACTUAL SFC TROUGHING.
EVENTUALLY BY LATER TONIGHT...THE LOW LEVEL TROUGHING
WEAKENS/DEPARTS...WITH THE ENTIRE ATMOSPHERIC COLUMN COLD ENOUGH
FOR JUST SNOW. CAN MAKE A REAL GOOD ARGUMENT FOR LIKELY SNOWS FOR
MOST EVERYONE AT SOME POINT DURING THE NIGHT. THIS DUE NOT ONLY TO
THE LINGERING TROUGHING AT THE SFC...BUT ALSO WITH MID LEVEL
TROUGHING WITH THE UPPER CIRCULATIONS...WHICH WILL BE ALIGNED
ACROSS EASTERN UPPER. THUS...WILL HAVE THE BETTER ACCUMULATIONS
AND CHANCES FOR SNOW THERE. MAYBE ANOTHER INCH ACROSS EASTERN
UPPER...WITH LESSER AMOUNTS HEADING FURTHER SOUTH.
CLOUDY THROUGH THE PERIOD WITH LITTLE DIURNAL SWINGS IN
TEMPERATURE. HIGHS IN THE 30S TODAY...WITH LOWS IN THE MIDDLE 20S
TO LOWER 30S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 350 AM EDT FRI APR 12 2013
SATURDAY...AS THE 500 MB LOW DRIFTS EAST JUST NORTH OF THE FORECAST
AREA, THERE WILL BE ENOUGH FORCING TO CONTINUE THE SNOW SHOWERS.
HOWEVER, THE KICKER IS THAT THE 850 MB TEMPERATURES FALL TO AROUND
-10C AND WITH THE WATER TEMPERATURES SLIGHTLY WARMER AROUND +1 TO
+2C WE WILL PROBABLY GET SOME ENHANCEMENT ESPECIALLY NEARER THE SFC
AND 500 MB LOWS. SO WILL HAVE AN AREA OF LIKELY POPS IN E UPPER AND
ENHANCED CHANCE POPS IN NW LOWER. BY 00Z, THINGS BEGIN TO LOOK LIKE
LAKE EFFECT, HOWEVER, THE PROBLEM IS THAT THE 850 MB TEMPERATURES
BEGIN TO WARM BIT, AND WE LOSE THE ENHANCEMENT.
SATURDAY NIGHT...WE LOSE GOOD 850 MB AND SFC FLOW AS THE
TEMPERATURES RISE TO AROUND -8C. WILL ALLOW FOR SOME FLURRIES EARLY,
BUT ALL THINGS BEING EQUAL, THINK THAT THE WITH THE DRIER AIR MOVING
IN AS WELL, THAT THE SNOW WILL STOP SHORTLY HAVE 00Z.
SUNDAY...THE NEXT SYSTEM BEGINS TO LIFT NORTH INTO NORTHERN PLAINS.
THE GFS HAS IT A LITTLE MORE EAST IN MINNESOTA, WHILE THE 00Z ECMWF
HAS IT IN E NORTH DAKOTA. THE DIFFERENCE IS THAT THE GFS BRINGS
CHANCE POPS INTO NW LOWER SOONER. WITH THESE SYSTEMS BEING KIND OF
ALL OVER THE PLACE, IN THE RUN UP TO THEM, WILL HEDGE BETWEEN THE
TWO. SO CUT THE POPS BACK SO THAT NW LOWER HAVE SOME CHANCE POPS,
AND THE REST OF THE REGION IS RELATIVELY DRY. OVERNIGHT, THE WARM
FRONT IN EITHER CASE MAKES IT FAR ENOUGH NORTH RAIN TAKES OVER IN E
UPPER. THE FRONT STALLS THERE AS WELL SO THAT THE SFC LOW RIDES UP
INTO LAKE SUPERIOR ALONG IT. SO RAIN WILL BE EXPECTED IN E UPPER AND
WITH THE WARM SECTOR MOVING NORTH WILL HAVE LESS CHANCES TO THE
SOUTH.
EXTENDED (MONDAY THROUGH THURSDAY)...MONDAY, EXPECTING RAIN FROM THE
SYSTEM MOVING THROUGH DURING THE DAY. OVERNIGHT, WITH THE FRONT
THROUGH AND THE SFC LOW TO THE EAST, WILL EXPECT THAT E UPPER AND
PORTIONS OF N LOWER WILL CLEAR OUT AS HIGH PRESSURE BUILDS INTO THE
REGION. TUESDAY, THE FRONT HOLDS TO THE EAST WITH HIGH PRESSURE
NOSING INTO LOWER MICHIGAN. LOOKS LIKE SOME RAIN COULD HOLD ON WITH
WAVES RUNNING UP THE FRONT. SO WILL ALLOW FOR SOME RAIN IN NE
LOWER. WEDNESDAY, THE NEXT SYSTEM BEGINS TO PUSH OUT OF THE SOUTHERN
PLAINS AND BY THE TIME THAT IT GETS INTO THE MID-MISSISSIPPI VALLEY,
THE RAIN WILL SPREAD BACK NORTH THROUGH N LOWER AND IN E UPPER,
WHERE A MIX WILL BE EXPECTED. OF COURSE, THE WARM AIR WILL CONTINUE
NORTH CHANGING THE SNOW BACK TO RAIN OVERNIGHT. THURSDAY, THE MODELS
HAVE TWO DIFFERENT TRACKS. THE ECMWF STILL BRINGS THE SFC LOW OVER N
LOWER, WHICH WOULD BRING MORE RAIN TO THE REGION BEFORE CHANGING TO
SNOW THURSDAY NIGHT. THE GFS BRINGS THE SFC LOW UP THROUGH LAKE
ERIE. THIS WOULD BRING SNOW OR RAIN AND SNOW TO N LOWER AND E UPPER.
DECIDED TO PLAY AS RAIN THURSDAY, RAIN/SNOW THURSDAY NIGHT FOR NOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 712 AM EDT FRI APR 12 2013
WIDESPREAD MVFR CIGS WILL PREVAIL THROUGHOUT THE TAF PERIOD WITH
LOADS OF LOW LEVEL MOISTURE SURROUNDING LOW PRESSURE LIFTING THROUGH
NRN MICHIGAN TODAY. MOISTURE IS QUICKLY PEELING OUT ALOFT EARLY IN
THE TAF PERIOD WHILE TEMPERATURES ARE COOLING THROUGHOUT THE
ATMOSPHERE. THIS IS RESULTING IN A TRANSITION TO A SCENARIO
CHARACTERIZED AS PERIODS OF LIGHT SNOW AND DRIZZLE/FREEZING DRIZZLE.
THIS WILL BE THE COMMON THEME INTO THE EVENING...BEFORE ONLY LIGHT
SNOW SHOWERS ARE GOING TO BE POSSIBLE FOR THE LATE NIGHT HOURS.
GUSTY EAST WINDS TO 30 MPH AT PLN/APN WILL DIE OFF THROUGH THE
DAY...JUST AS THEY DID ACROSS MBL AND TVC. THESE WINDS WILL
GRADUALLY BACK AROUND OUT OF THE NORTH AND ULTIMATELY THE WEST BY
SATURDAY MORNING...AS THE LOW PRESSURE EXITS FURTHER EAST.
&&
.MARINE...
ISSUED AT 350 AM EDT FRI APR 12 2013
GALE FORCE GUSTS ARE IN FULL EFFECT ACROSS MOST OF THE SURROUNDING
NEARSHORE WATERS OF LAKES HURON AND MICHIGAN...NORTH OF GRAND
TRAVERSE LIGHT AND STURGEON POINT LIGHT. NORTH OF THERE...SOLID
ADVISORY LEVEL GUSTS WERE ONGOING...WHILE SOUTH OF THE
GALES...WINDS WERE DROPPING OFF RATHER QUICKLY WITH A LOOSE
GRADIENT ALONG LOW PRESSURE LIFTING NORTHWARD. THIS LIGHTER
GRADIENT WILL GRADUALLY OVERTAKE ALL OF THE NEARSHORE WATERS
THROUGH THE DAY...WITH GALES GRADUALLY STEPPING DOWN INTO
ADVISORY...THEN SUB ADVISORY LEVELS. THE LOW PRESSURE LIFTS EAST
TONIGHT...WITH COLD ADVECTION AND WESTERLY WINDS DEVELOPING...BUT
EXPECTATIONS ARE FOR WINDS TO BE BELOW ADVISORY LEVELS THROUGH
EARLY SUNDAY. THE NEXT LOW PRESSURE SYSTEM IS SET FOR LATER SUNDAY
AND INTO MONDAY. ADDITIONAL HEADLINES MAY BE REQUIRED.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WARNING UNTIL 7 PM EDT THIS EVENING FOR MIZ008-015.
LH...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LHZ349.
GALE WARNING UNTIL 11 AM EDT THIS MORNING FOR LHZ345>348.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ323-341-
344.
GALE WARNING UNTIL 11 AM EDT THIS MORNING FOR LMZ342.
LS...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LSZ321-322.
&&
$$
UPDATE...SD
SYNOPSIS...JL
SHORT TERM...SD
LONG TERM...JL
AVIATION...SD
MARINE...SD
AREA FORECAST DISCUSSION
NWS GAYLORD MI
416 AM EDT FRI APR 12 2013
.SYNOPSIS...
ISSUED AT 350 AM EDT FRI APR 12 2013
SLOW MOVING...LOW PRESSURE IS LIFTING INTO THE UPPER GREAT LAKES
REGION AND WILL BRING A WINTRY MESS OF PRECIPITATION TYPES TO
NORTHERN MICHIGAN TODAY. THE FREEZING RAIN AND SLEET IS EXPECTED TO
TRANSITION OVER TO SNOW AND DRIZZLE THIS MORNING. THIS WILL CONTINUE
INTO THE EVENING BEFORE CHANGING TO ALL SNOW TONIGHT. HIGH PRESSURE
TRIES TO SNOW INTO THE REGION ON SATURDAY SO THAT WE WILL GET A
BREAK FOR THE WEEKEND.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 350 AM EDT FRI APR 12 2013
CURRENTLY...POTENT UPPER LEVEL CLOSED LOW IS DRIFTING ACROSS THE
FAR NRN MISSISSIPPI VALLEY...WITH OCCLUDED LOW PRESSURE FROM THE
APPALACHIANS...AND TROUGHING/TROWAL EXTENDING BACK INTO SRN
WISCONSIN. MAIN H8-H7 WARM ADVECTION EXTENDS ALONG H8 WIND SPEED
MAX WHICH IS NOW EXTENDING FROM THE EASTERN GREAT LAKES BACK AROUND
THROUGH EASTERN UPPER MICHIGAN. THIS IS WHERE ONE SWATH OF BETTER
PRECIPITATION...IN THE FORM OF SNOW AND SOME SLEET...IS CO-LOCATED
WITH STRONG POCKET OF UPPER DIVERGENCE IN RIGHT ENTRANCE REGION OF
QUEBEC 120+KT UPPER JET. ANOTHER JET STREAK WAS CROSSING THE OHIO
RIVER VALLEY...AND ANOTHER POCKET OF UPPER DIVERGENCE IN LEFT EXIT
REGION OF WAS DEVELOPING ACROSS THE EASTERN GREAT LAKES. DPVA
AROUND THE CLOSED LOW ALOFT...COMBINED WITH THESE FORCING
MECHANISMS...HAS RESULTED IN MODEST TO STRONG DEEP LAYER LIFT AND
WIDESPREAD PRECIPITATION ACROSS MAINLY NE LOWER AND BACK AROUND
THROUGH EASTERN UPPER.
NOW...THERMALLY SPEAKING...WE HAVE GONE THROUGH QUITE ALONG PERIOD
OF SLEET AND FREEZING RAIN IN NRN LOWER...AS 00Z APX SOUNDING TELLS
THE STORY. 800-700MB DEEP 2-3C WARM NOSE IS EVIDENT...WITH A
COUNTERING DEEP SFC-800MB COLD LAYER WITH A MAXIMUM -6C READING AT
900MB...COLD ENOUGH TO RE-FREEZE TOTALLY MELTED DROPS FROM THAT 2-3C
DEEP WARM NOSE. ONE OF THE BETTER SLEET SOUNDINGS THIS FORECASTER
HAS SEEN. AS THE ENTIRE SYSTEM HAS BEEN SLOW TO TRANSITION NORTH AND
EAST WITH TIME...QUITE A BIT OF SLEET HAS BEEN ABLE TO FALL AND
ACCUMULATE. ACROSS EASTERN UPPER...SOME SLEET MAY BE TRYING TO MIX
WITH WHAT SHOULD BE PRIMARILY SNOW...BASED ON LATEST DUAL POL RADAR
LOOPING. RUC FCST SOUNDINGS ALSO SUGGEST ALL SNOW IN EASTERN
UPPER...WITH THE ELEVATED WARM COOLING STARTING AS OF THIS WRITING.
LATEST OBS SUGGESTING THAT THIS MAY BE TAKING PLACE NOW WITH MORE
OBSERVATIONS ACROSS THE WEST NOW LOOKING MORE "SNOWY" RATHER THAN
"ICY". ALSO IN THE MIX...IS THE CURRENT EFFORT FOR DEEPER MOISTURE
TO STRIP OUT ALOFT FROM THE WEST...WHICH ALLOWS US TO EXPERIENCE YET
ANOTHER PRECIPITATION TYPE...DRIZZLE AND FREEZING DRIZZLE.
IT SHOULD BE WORTH NOTING THAT NOT ALL FOLKS HAVE EXPERIENCED THIS
PLETHORA OF NASTY WINTRY WEATHER. DOWNSLOPING REGIONS ACROSS NW
LOWER...MAINLY FRANKFORT AND MANISTEE AREAS...WERE ABOVE FREEZING
FOR MUCH OF THE NIGHT...SO NOT FREEZING RAIN THERE.
IN THE SPIRIT OF A FORMER NWS COLLEAGUE..."WELL...AT LEAST IT`S
WINDY". YEAH...EAST WINDS WERE GUSTING AS HIGH AS 35-40 MPH MUCH OF
THE NIGHT TOO.
NOW...THE FORECAST...POTENT UPPER LOW WILL LIFT INTO EASTERN LAKE
SUPERIOR TODAY AND TONIGHT...WITH THE SFC TROUGHING/TROWAL AND
AXIS OF DEEPER MOISTURE AND FORCING LIFTING NORTH AND EAST
THROUGH THE MORNING. COLDER AIR SEEPS IN...AND THE TRANSITION OVER
TO MAINLY LIGHT SNOW WILL BE JOINED BY DRIZZLE AND FREEZING
DRIZZLE DUE TO DRYING ALOFT. THE THERMAL PROFILES BECOME AN
INCREASINGLY LIGHT SNOW/DRIZZLE LOOK...AS MOISTURE WILL BE AT OR
BELOW 10C FOR MOST OF THE DAY AND EVEN INTO THE EVENING. THE BEST
MOISTURE/FORCING WILL BE ACROSS CHIPPEWA COUNTY FOR THE LONGEST
PERIOD OF TIME. HERE...ALTHOUGH TOTAL QPF/SNOWFALL WERE LOWERED
SLIGHTLY...WILL STILL SEE A GRAND TOTAL OF 4 TO 8 INCHES BY THE
END OF THE DAY. LESSER AMOUNTS HEADING SOUTH UNTIL JUST AN INCH
DOWN NEAR THE M-55 CORRIDOR. CURRENT WINTER STORM HEADLINES WILL
HOLD TRUE...ENDING FROM SOUTH TO NORTH THROUGH THE DAY. LIGHT
SNOWS AND DRIZZLE ARE LIKELY AT LEAST INTO THE EVENING DUE TO THE
LOW LEVEL CONVERGENCE ASSOCIATED WITH THE ACTUAL SFC TROUGHING.
EVENTUALLY BY LATER TONIGHT...THE LOW LEVEL TROUGHING
WEAKENS/DEPARTS...WITH THE ENTIRE ATMOSPHERIC COLUMN COLD ENOUGH
FOR JUST SNOW. CAN MAKE A REAL GOOD ARGUMENT FOR LIKELY SNOWS FOR
MOST EVERYONE AT SOME POINT DURING THE NIGHT. THIS DUE NOT ONLY TO
THE LINGERING TROUGHING AT THE SFC...BUT ALSO WITH MID LEVEL
TROUGHING WITH THE UPPER CIRCULATIONS...WHICH WILL BE ALIGNED
ACROSS EASTERN UPPER. THUS...WILL HAVE THE BETTER ACCUMULATIONS
AND CHANCES FOR SNOW THERE. MAYBE ANOTHER INCH ACROSS EASTERN
UPPER...WITH LESSER AMOUNTS HEADING FURTHER SOUTH.
CLOUDY THROUGH THE PERIOD WITH LITTLE DIURNAL SWINGS IN
TEMPERATURE. HIGHS IN THE 30S TODAY...WITH LOWS IN THE MIDDLE 20S
TO LOWER 30S.
&&
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 350 AM EDT FRI APR 12 2013
SATURDAY...AS THE 500 MB LOW DRIFTS EAST JUST NORTH OF THE FORECAST
AREA, THERE WILL BE ENOUGH FORCING TO CONTINUE THE SNOW SHOWERS.
HOWEVER, THE KICKER IS THAT THE 850 MB TEMPERATURES FALL TO AROUND
-10C AND WITH THE WATER TEMPERATURES SLIGHTLY WARMER AROUND +1 TO
+2C WE WILL PROBABLY GET SOME ENHANCEMENT ESPECIALLY NEARER THE SFC
AND 500 MB LOWS. SO WILL HAVE AN AREA OF LIKELY POPS IN E UPPER AND
ENHANCED CHANCE POPS IN NW LOWER. BY 00Z, THINGS BEGIN TO LOOK LIKE
LAKE EFFECT, HOWEVER, THE PROBLEM IS THAT THE 850 MB TEMPERATURES
BEGIN TO WARM BIT, AND WE LOSE THE ENHANCEMENT.
SATURDAY NIGHT...WE LOSE GOOD 850 MB AND SFC FLOW AS THE
TEMPERATURES RISE TO AROUND -8C. WILL ALLOW FOR SOME FLURRIES EARLY,
BUT ALL THINGS BEING EQUAL, THINK THAT THE WITH THE DRIER AIR MOVING
IN AS WELL, THAT THE SNOW WILL STOP SHORTLY HAVE 00Z.
SUNDAY...THE NEXT SYSTEM BEGINS TO LIFT NORTH INTO NORTHERN PLAINS.
THE GFS HAS IT A LITTLE MORE EAST IN MINNESOTA, WHILE THE 00Z ECMWF
HAS IT IN E NORTH DAKOTA. THE DIFFERENCE IS THAT THE GFS BRINGS
CHANCE POPS INTO NW LOWER SOONER. WITH THESE SYSTEMS BEING KIND OF
ALL OVER THE PLACE, IN THE RUN UP TO THEM, WILL HEDGE BETWEEN THE
TWO. SO CUT THE POPS BACK SO THAT NW LOWER HAVE SOME CHANCE POPS,
AND THE REST OF THE REGION IS RELATIVELY DRY. OVERNIGHT, THE WARM
FRONT IN EITHER CASE MAKES IT FAR ENOUGH NORTH RAIN TAKES OVER IN E
UPPER. THE FRONT STALLS THERE AS WELL SO THAT THE SFC LOW RIDES UP
INTO LAKE SUPERIOR ALONG IT. SO RAIN WILL BE EXPECTED IN E UPPER AND
WITH THE WARM SECTOR MOVING NORTH WILL HAVE LESS CHANCES TO THE
SOUTH.
EXTENDED (MONDAY THROUGH THURSDAY)...MONDAY, EXPECTING RAIN FROM THE
SYSTEM MOVING THROUGH DURING THE DAY. OVERNIGHT, WITH THE FRONT
THROUGH AND THE SFC LOW TO THE EAST, WILL EXPECT THAT E UPPER AND
PORTIONS OF N LOWER WILL CLEAR OUT AS HIGH PRESSURE BUILDS INTO THE
REGION. TUESDAY, THE FRONT HOLDS TO THE EAST WITH HIGH PRESSURE
NOSING INTO LOWER MICHIGAN. LOOKS LIKE SOME RAIN COULD HOLD ON WITH
WAVES RUNNING UP THE FRONT. SO WILL ALLOW FOR SOME RAIN IN NE
LOWER. WEDNESDAY, THE NEXT SYSTEM BEGINS TO PUSH OUT OF THE SOUTHERN
PLAINS AND BY THE TIME THAT IT GETS INTO THE MID-MISSISSIPPI VALLEY,
THE RAIN WILL SPREAD BACK NORTH THROUGH N LOWER AND IN E UPPER,
WHERE A MIX WILL BE EXPECTED. OF COURSE, THE WARM AIR WILL CONTINUE
NORTH CHANGING THE SNOW BACK TO RAIN OVERNIGHT. THURSDAY, THE MODELS
HAVE TWO DIFFERENT TRACKS. THE ECMWF STILL BRINGS THE SFC LOW OVER N
LOWER, WHICH WOULD BRING MORE RAIN TO THE REGION BEFORE CHANGING TO
SNOW THURSDAY NIGHT. THE GFS BRINGS THE SFC LOW UP THROUGH LAKE
ERIE. THIS WOULD BRING SNOW OR RAIN AND SNOW TO N LOWER AND E UPPER.
DECIDED TO PLAY AS RAIN THURSDAY, RAIN/SNOW THURSDAY NIGHT FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 132 AM EDT FRI APR 12 2013
ICY MIX OF PRECIP OVERNIGHT. MAINLY MVFR CONDITIONS (CIGS) FRIDAY.
COMPLEX AREA OF LOW PRESSURE ACROSS THE SOUTHERN GREAT LAKES...WILL
LIFT NORTH TO NORTHERN LAKE HURON BY THURSDAY EVENING. WINTRY PRECIP
CONTINUES AT MOST TAF SITES...WITH PLN SEEING MOSTLY -SN (IFR) AND
APN/TVC PL/FZRA/RA (MVFR TO IFR). MBL IS OUT OF THE WORST OF
IT...WITH ONLY RATHER LIGHT PRECIP EXPECTED. APN/TVC WILL TRANSITION
TO SN/DZ BEFORE ENDING FRIDAY. CIGS ARE MOSTLY MVFR...AND WILL
REMAIN SO...THOUGH WITH SOME VARIABILITY OVERNIGHT.
BLUSTERY EAST WINDS WILL BACK NE AND WEAKEN A BIT TONIGHT AND
ESPECIALLY FRIDAY. WINDS SHIFTING TO THE W/NW LATE FRIDAY.
&&
.MARINE...
ISSUED AT 350 AM EDT FRI APR 12 2013
GALE FORCE GUSTS ARE IN FULL EFFECT ACROSS MOST OF THE SURROUNDING
NEARSHORE WATERS OF LAKES HURON AND MICHIGAN...NORTH OF GRAND
TRAVERSE LIGHT AND STURGEON POINT LIGHT. NORTH OF THERE...SOLID
ADVISORY LEVEL GUSTS WERE ONGOING...WHILE SOUTH OF THE
GALES...WINDS WERE DROPPING OFF RATHER QUICKLY WITH A LOOSE
GRADIENT ALONG LOW PRESSURE LIFTING NORTHWARD. THIS LIGHTER
GRADIENT WILL GRADUALLY OVERTAKE ALL OF THE NEARSHORE WATERS
THROUGH THE DAY...WITH GALES GRADUALLY STEPPING DOWN INTO
ADVISORY...THEN SUB ADVISORY LEVELS. THE LOW PRESSURE LIFTS EAST
TONIGHT...WITH COLD ADVECTION AND WESTERLY WINDS DEVELOPING...BUT
EXPECTATIONS ARE FOR WINDS TO BE BELOW ADVISORY LEVELS THROUGH
EARLY SUNDAY. THE NEXT LOW PRESSURE SYSTEM IS SET FOR LATER SUNDAY
AND INTO MONDAY. ADDITIONAL HEADLINES MAY BE REQUIRED.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WARNING UNTIL 9 AM EDT THIS MORNING FOR MIZ020-
025>036-041-042.
WINTER STORM WARNING UNTIL NOON EDT TODAY FOR MIZ016>019-021>024.
WINTER STORM WARNING UNTIL 7 PM EDT THIS EVENING FOR MIZ008-015.
LH...GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR LHZ345>349.
LM...GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR LMZ341-342.
LS...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR LSZ321-322.
&&
$$
SYNOPSIS...JL
SHORT TERM...SD
LONG TERM...JL
AVIATION...JZ
MARINE...SD
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1255 AM EDT FRI APR 12 2013
.AVIATION...
//DISCUSSION...
IFR CEILINGS AND RAIN SHOWERS WILL PERSIST OVERNIGHT...AS LOW
PRESSURE TRACKS INTO THE EASTERN GREAT LAKES. A WIND SHIFT TO THE
SOUTHWEST AND MID LEVEL DRY SLOT ARRIVING WILL ALLOW RAIN TO
TAPER OFF BETWEEN 10-12Z. PLENTY OF LOW LEVEL MOISTURE HOWEVER
SHOULD ASSURE MVFR CEILINGS TODAY INTO TONIGHT...WITH A LOW CHANCE
OF RAIN SHOWERS THIS AFTERNOON. THERE WILL THEN BE A LOW CHANCE OF
RAIN AND OR SNOW SHOWERS TONIGHT...BUT CONVERGE UNCERTAINTY DOES
NOT WARRANT INCLUSION IN TAFS.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE ON CEILING BELOW 5000 FT THROUGH THE TAF PERIOD.
&&
.PREV DISCUSSION...ISSUED 927 PM EDT THU APR 11 2013
UPDATE...
WITNESSING A BIFURCATION OR SPLITTING OF THE MAIN PRECIPITATION
SWATH (ALABAMA TO MICHIGAN) INTO TWO BRANCHES. THIS IS OCCURRING AT
THE FAR NORTHERN END/OVER MICHIGAN DUE TO DIFFLUENCE OF SYSTEM
RELATIVE FLOW IN THE 500-300 MB LAYER. THE ANTICYCLONIC BRANCH
(EAST..RIGHT) IS HARBORING THE PRECIPITATION NOW PUSHING INTO AREAS
SOUTH OF DETROIT. EXPECT THIS TO CONTINUE TO LIFT
NORTHWARD...WHILE TRENDING EAST OR BRUSHING THE CWA THROUGH THE
EVENING. EARLIER MODELS WERE SUGGESTING THIS WOULD ROCKET
THROUGH...ENDING BY 5Z TONIGHT HOWEVER...11.23Z RUC IS MORE
REPRESENTATIVE WITH THE CURRENT PRECIP SHIELD AND HAS END TIMING BY
7Z. IT IS THIS ANTICYCLONIC BRANCH THAT PERTAINS TO THE WARM THETA
E SURGE THAT WILL OCCUR OVER THE EASTERN HALF OF THE CWA. EXPECT A
STRAIGHT RAIN WITH TEMPERATURES THAT WILL EVEN RISE A COUPLE OF
DEGREES MOVING FORWARD. GIVEN THE RUC DEPICTION EXPECTING THIS WAA
TO LIFT NORTHWARD THROUGH THE THUMB...LARGELY HOLDING OFF ANY
PRECIPITATION TYPE CONCERNS.
THE PRECIPITATION DEVELOPING (AN HOUR OR TWO EARLIER THAN EXPECTED)
OVER WESTERN LOWER MICHIGAN IS ASSOCIATED WITH THE CYCLONIC BRANCH
(WEST...LEFT). THIS PRECIPITATION IS EXPECTED TO FILL IN AND SLOW
DOWN DURING THE DURATION OF THE EVENING WHILE LIFTING NORTHWARD
AND TRYING TO ALIGN WEST NORTHWEST TO EAST SOUTHEAST. THE CURRENT
TRAJECTORY OF THE PRECIPITATION IS DEVELOPING AS EXPECTED...TRACKING
TOWARDS THE SAGINAW VALLEY. EARLIER...MADE SOME PHONE CALLS AFTER
READING THE REPORT OF FREEZING RAIN FROM A NEIGHBORING OFFICE.
THERE WERE MULTIPLE REPORTS OF CARS SLIDING OFF ROADWAYS AND SLICK
TRAVEL CONDITIONS IN MIDLAND COUNTY. SUSPECT MUCH OF THIS GLAZING
OCCUR ED WITH THE HEAVIER PRECIPITATION RATES/EVAPORATIVE COOLING
POTENTIAL OF THE CONVECTIVE SHOWERS THAT LIFTED THROUGH THE
COUNTY BETWEEN 21-23Z. MOVING FORWARD...CYCLONIC BRANCH TRANSPORT
SHOULD LIFT INTO BAY AND MIDLAND COUNTIES BRINGING CONTINUED
CHANCES FOR LIGHT TO MODERATE PRECIPITATION THIS EVENING. A ZONAL
+90 KNOT JET OVER OKLAHOMA IS CURRENTLY DIGGING THROUGH THE BASE
OF THE TROUGH. THIS ACTION SHOULD CAUSE THE CLOSED LOW TO ROTATE
WHILE LOFTING THE POTENTIAL VORTICITY ANOMALY INTO WISCONSIN. IN
RESPONSE TO THE LOW CREEPING CLOSER...EXPECT TROWAL DYNAMICS TO
INCREASE ACROSS THE NORTHERN CWA BY 3Z PERSISTING THROUGH 9Z.
AS NOTED EARLIER...THE BULK OF WARM AIR ADVECTION WILL OCCUR OVER
THE EASTERN CWA...SO PRECIPITATION TYPE CONCERNS WILL CONTINUE.
850MB THERMAL PROGS SHOW ENOUGH WARM AIR WITHIN THE BOLSTERING TROWAL
TO SUPPORT A PREDOMINATE LIQUID TYPE. GIVEN THE CONCERNS THE
DECISION WAS MADE TO ISSUE A WINTER WEATHER ADVISORY FOR FREEZING
RAIN THROUGH 12Z FRIDAY. A SATURATED ENVIRONMENT RIGHT AT THE
FREEZING MARK BRINGS CONCERNS FOR OVERALL GLAZING AMOUNTS...BUT AN
ADDITIONAL .1 TO .2 INCHES SEEMS REASONABLE. EASTERLY SURFACE
WINDS IN THE SAGINAW VALLEY HAVE BEEN NOTEWORTHY AND
CONCERNING...WITH 20 TO 30 KNOTS OF FLOW. SPORADIC POWER OUTAGES
WILL BE POSSIBLE. PRECIPITATION TYPE MAY TRY TO TRANSITION TO
LIGHT SNOW LATE...BUT GIVEN PERSISTENT TROWAL IN PLACE SUSPECT
THIS WILL BE DIFFICULT TO OCCUR BEFORE THE BACK EDGE OF THE
PRECIPITATION LIFTS NORTHWARD. WILL CONTINUE TO MONITOR AND UPDATE
THE FORECAST AS NEEDED.
PREV DISCUSSION...ISSUED 358 PM EDT THU APR 11 2013
SHORT TERM... THE REMAINDER OF TODAY THROUGH TONIGHT
THE FLOOD WATCH WILL REMAIN IN EFFECT THROUGH TONIGHT AFTER SOME
BRIEF CONSIDERATION OF DROPPING FOR THE TRI CITIES. DECIDED TO HOLD
ON THERE AS WELL GIVEN MODEL TRENDS THAT LOOK REASONABLE BRINGING
THE WESTERN FLANK OF THE NEXT MOISTURE SURGE THAT FAR NORTH AND WEST
INTO THE REGION. THE PATTERN WILL INCREASE STEADILY DURING THE REST
OF THE AFTERNOON THROUGH TONIGHT AS MOISTURE TRANSPORT, RESPONSIBLE
FOR THE OHIO VALLEY ACTIVITY, WORKS NORTHWARD THROUGH LOWER
MICHIGAN. THIS IS JUST A CLASSIC CASE OF MERIDIONAL UPPER JET
SUPPORT FOR A WELL ORGANIZED AGEOSTROPHIC CIRCULATION ALONG THE COLD
FRONT. STRONG GULF MOISTURE TRANSPORT THROUGH THE LOWER HALF OF THE
ATMOSPHERE WILL ENSURE THE RESULTING PATTERN OF SHOWERS IS INGESTED
INTO THE DEEP DIFFLUENT FLOW ALOFT OVER THE GREAT LAKES DURING THE
EVENING. EXPECT THE OCCLUSION PROCESS TO MATURE DURING THE OVERNIGHT
WHICH WILL CARRY THE TROWAL AXIS AS FAR NORTH AS THE TRI CITIES
AFTER MIDNIGHT AND THE TRAILING SURFACE TROUGH THAT FAR NORTH BY
SUNRISE FRIDAY. MODEL SOLUTIONS IN THIS REGARD LOOK GOOD AND SUPPORT
MAINTAINING THUS SUPPORT MAINTAINING THE FLOOD WATCH HEADLINE FOR
ALL AREAS AT LEAST UNTIL OBSERVATIONS CAN HELP REFINE THE WESTERN
EDGE OF THE RAIN SHIELD.
WHILE SHOWERS AND A RUMBLE OF THUNDER WILL BE THE MODE OF
PRECIPITATION FOR ALL AREAS TONIGHT, SURFACE TEMPERATURE TRENDS WILL
OTHERWISE BE MONITORED FOR PRECIPITATION TYPE CONSIDERATIONS IN THE
TRI CITIES AND NORTHERN THUMB. AS IT STANDS NOW, SURFACE TEMPERATURE
IS EXPECTED TO BE MODULATED UPWARD IN THAT AREA BY THE APPROACH OF
THE SURFACE TROUGH/OCCLUSION DURING THE EVENING AND THEN SOLIDLY
SUPPORTED ABOVE FREEZING OVERNIGHT. THERE IS A CHANCE OF WINTRY MIX
MENTIONED IN THE FORECAST MAINLY NORTH OF M-46 AS A BUFFER UP
AGAINST THE HIGHER POTENTIAL TAKING SHAPE IN NORTHERN LOWER
MICHIGAN.
LONG TERM...FRIDAY THROUGH WEDNESDAY
STRONG RIGHT ENTRANCE JET SUPPORT WILL RAPIDLY WANE DURING THE
MORNING HOURS AS THE LARGE UPPER LOW OVER THE CENTRAL CONUS LIFTS TO
THE NORTH AND JET FORCING IS SHUNTED WELL NORTH OF THE AREA. THE
ASSOCIATED INTENSITY DECLINE OF MOIST ISENTROPIC ASCENT AND
NORTHWARD ROTATION OF H85-H7 DEFORMATION LAYER WILL SPELL QUICKLY
DIMINISHING PRECIP CHANCES TO START THE PERIOD, AT LEAST AS FAR AS
ORGANIZED PRECIP. STILL TAPERED POPS DOWN S LOWLY, HOWEVER, GIVEN
THE PRESENCE OF THE ELONGATED SURFACE TROUGH INDICATED ON THE 12Z
NAM. DIURNAL HEATING ALONG WITH THE EXTRA BOOST OF LOW-LEVEL
CONVERGENCE IN THE PRESENCE OF LIGHT COLD ADVECTION & A MOIST
BOUNDARY LAYER WILL BE STRONGLY SUPPORTIVE FOR SOME REDEVELOPMENT OF
SHOWERS AS THE AXIS LIFTS NORTH THROUGH THROUGH EARLY AFTERNOON.
HOWEVER, EVEN AS ANY LINGERING DIURNAL ACTIVITY WANES LATE IN THE
DAY, ONGOING COLD ADVECTION THROUGH FRIDAY NIGHT SHOULD BE
SUFFICIENT TO MAINTAIN WELL-MIXED THERMAL PROFILES AND QUITE
POSSIBLY ANOTHER ROUND OF SURFACE-BASED SHOWER ACTIVITY,
PARTICULARLY AS A LOW AMPLITUDE PV ANOMALY ROTATES ACROSS THE STATE
DURING THE FIRST HALF OF THE NIGHT. CYCLONIC FLOW ALOFT WILL FOSTER
ANOTHER SHORTWAVE ACROSS THE STATE DURING THE DAY ON SATURDAY. THE
GENERAL MODEL CONSENSUS DEPICTS THE WAVE EVOKING WESTERLY WINDS AT
THE SURFACE AND REINFORCING THE EXISTING COLD AIRMASS AS H85 TEMPS
FALL TO AROUND -10C BY LATE IN THE DAY. CONVERGENT WESTERLY LOW
WITHIN THE BOUNDARY LAYER AND MODERATE COLD ADVECTION COMBINED WITH
MID APRIL SUN SHOULD BE QUITE FAVORABLE FOR A DIURNALLY ENHANCED
LAKE EFFECT SCENARIO. COLD THERMAL PROFILES APPEAR SUPPORTIVE FOR
SNOW WITHIN MOST SHOWERS. HIGHS WILL STRUGGLE OUT OF THE 30S DURING
PEAK HEATING.
MARINE...
STRONG NORTHEAST WIND WILL PERSIST TONIGHT OVER ALL MARINE AREAS AS
A LOW PRESSURE SYSTEM LIFTS INTO THE OHIO VALLEY AND EVENTUALLY INTO
CENTRAL LOWER MICHIGAN TONIGHT INTO FRIDAY. GALES REMAIN LIKELY
ACROSS THE NORTHERN HALF OF LAKE HURON AS THIS PROCESS COMMENCES AND
A GALE WARNING REMAINS IN EFFECT. THE PERSISTENT AND INCREASING
NORTHEAST FLOW WILL CAUSE WAVE HEIGHTS TO BUILD OVER SAGINAW BAY AND
THE LAKE HURON NEARSHORE WATERS OFF THE THUMB AND WILL RESULT IN AN
EXTENDED PERIOD OF ROUGH WATER THERE. IMPROVING CONDITIONS WITH
DIMINISHING WINDS AND WAVES WILL OCCUR FRIDAY INTO FRIDAY NIGHT AS
THE SYSTEM EXITS EASTWARD.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...FLOOD WATCH...MIZ047-MIZ048-MIZ049-MIZ053-MIZ054-MIZ055-MIZ060-
MIZ061-MIZ062-MIZ063-MIZ068-MIZ069-MIZ070-MIZ075-MIZ076-MIZ082-
MIZ083...UNTIL 8 AM FRIDAY.
ICE STORM WARNING...MIZ047-MIZ048...UNTIL 8 AM FRIDAY.
LAKE HURON...
GALE WARNING...LHZ361-LHZ362-LHZ363-LHZ462...UNTIL 10 AM FRIDAY.
GALE WARNING...SAGINAW BAY AND THE NEARSHORE WATERS FROM PORT
AUSTIN TO HARBOR BEACH...UNTIL 4 AM FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM HARBOR BEACH TO PORT
HURON...UNTIL 10 AM FRIDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....SF
UPDATE.......CB
SHORT TERM...BT
LONG TERM....JVC
MARINE.......BT
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
959 AM EDT FRI APR 12 2013
.SYNOPSIS...
A STORM SYSTEM AND ASSOCIATED FRONTAL ZONE WILL MOVE ACROSS THE
REGION TODAY...BRINGING A SOAKING RAIN TO MUCH OF THE AREA. THE
WEEKEND WILL REMAIN UNSETTLED...WITH SCATTERED SHOWERS...AS AN
UPPER LEVEL DISTURBANCE REMAINS IN THE VICINITY.
&&
.NEAR TERM /THROUGH TONIGHT/...
945 AM UPDATE...
WIDESPREAD RAIN ALONG WITH ISOLD THUNDER IS MVG INTO CWA AT THIS
TIME. CLOUD-GROUND LIGHTNING STRIKES REPORTED SEVERAL HRS AGO BUT
HV SINCE DISSIPATED, HOWEVER POTENTIAL EXISTS FOR IN-CLOUD
LIGHTNING ALONG WITH A RUMBLE OF THUNDER. HWVR ELEVATED CAPE
APPEARS TO BE MORE PROMINENT IN THE NEXT HR OR TWO DOWN TO THE
SOUTH AS OPPOSED TO FURTHER NORTH, THUS HV REDUCED CHC THUNDER TO
ISOLD THUNDER FOR TDA.
MODELS ARE DOING VRY POOR WITH HANDLING OF DRY SLOT WITH LATEST
HRRR DATA HANDLING THE REFLECTIVITY GRADIENT BEST. BACK EDGE HAS
MVD INTO CNTRL PA AND TIMING OF THIS WOULD PUT IT INTO SRN TIER BY
NOON WHICH IS SIMILAR TO HRRR TIMING.
AS FOR ICING, STILL SOME POTENTIAL FOR ICING AT ELEVATIONS BTWN
1600 AND 2000 FEET PER LATEST RAP BUFKIT PROFILES. MESONET SITES
IN ISOLD LOCATIONS HANGING IN THE MID-30S WITH SHELDRAKE OB IN
SULLIVAN COUNTY BLO FRZG, THO THIS SEEMS OUT OF PLACE COMPARED TO
THOSE AROUND IT. WL ALLOW WINTER WX ADVISORY TO EXPIRE AT 15Z AND
CONTINUE SPS/HWO MENTION FOR ISOLD LOCALES POSSIBLY SEEING ICING
INTO EARLY AFTN.
WINDS WL GUST TO BETWEEN 30 AND 40 MPH FOR ANOTHER HOUR OR TWO
THIS BFR PRESSURE GRADIENT RELAXES THIS AFTN. NO OTHER CHGS NEEDED
AT THIS TIME.
610 AM UPDATE...
TEMPS ACRS THE WRN CATSKILLS CONTINUE THEIR SLOW RISE...WITH ONLY
ONE MESO SITE (EAST OF MONTICELLO...LOCH SHELDRAKE) REPORTING
32/32. LATEST LAPS PROFILES SUGGEST MAIN POTNL FOR ICING WOULD BE
IN A LAYER ROUGHLY FROM AROUND 1700-2200 FT. GIVEN THE OBSERVED
TRENDS...AND WITH PCPN NOT REACHING THE AREA FOR A FEW MORE
HRS...WE`LL LET FCST RIDE (NO NEW HEADLINES). ICING POTNL IS
DISCUSSED IN THE HWO...AND SPS MAY BE ISSUED LATER IF NEEDED FOR
ISOLATED ICING POTNL. PREV BLO...
COMPLICATED FCST W/RESPECT TO -FZRA POTNL ACRS ERN ZONES. VARYING
SOLUTIONS FOR THE LOW LVL THERMAL FIELDS...WITH NAM AND RUC
SUGGESTING THAT FAR ERN DELAWARE AND SULLIVAN COUNTIES COULD SEE
DAMMING OF COLD AIR INTO THE EARLY AFTN HRS. HOWEVER...T/TD`S ARE
VERY MARGINAL. MDL PROFILES INDICATE COOL AIR IS VERY SHALLOW WITH
A DEEP WARM ELEVATED LAYER...SUGGESTING THAT TEMPS AND TD`S COULD
ACTUALLY RISE WITH ONSET OF PCPN...AND MAIN TREND THUS FAR FOR T/TD`S
HAS BEEN FOR A VERY SLOW RISE. ADD TO THIS A PROJECTED START TIME
OF PCPN AFTER 12Z FURTHER COMPLICATING THE ISSUE. MARGINAL SITUATION
AND AFTER MUCH DEBATE WE WILL NOT ISSUE ANY ADDITIONAL ADVISORIES THIS
PCKG BUT WILL CONTINUE TO CLOSELY MONITOR. WE WILL ALLOW CRNT
ADVISORIES TO REMAIN UP INTO THE MRNG HRS FOR NRN ONEIDA AND
OTSEGO...ALTHO PCPN HERE WILL BE SPOTTY AT BEST THROUGH THE EARLY
MRNG HRS. FLOOD WATCH WILL ALSO REMAIN IN EFFECT FOR NRN ONEIDA
COUNTY DUE TO POTNL FOR +RA AIDED BY SNOW MELT. GUSTY SE WINDS
AHEAD OF THE FNT TDA WITH G30 LIKELY SPCLY HIER ELEVATIONS. MDLS
SHOW SI`S ARPCHNG ZERO ACRS PORTIONS OF NE PA AND THE SRN
TIER...CAN`T RULE OUT ISOLD TSRA THIS AFTN BUT WILL LET DAYSHIFT
ADD IF NEEDED.
MAIN BATCH OF RAIN WILL PULL OUT OF ERN ZONES THIS AFTN. FCST AREA
WILL BE LEFT IN SW FLOW ALOFT WITH MDLS SHOWING ANOTHER S/WV
PASSING ARND 06Z TNGT. LOW CHC POPS TO ACCOUNT FOR THIS FEATURE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
LTL CHG TO PREV FCST. S/WV`S WILL CONTINUE TO ROTATE ARND THE GT
LAKES UPR LOW...WITH MDLS INDICATING ONE FOR SAT AFTN AND ANOTHER
LATE SAT NGT AND SUN MRNG. SCT -SHRA WITH SOME -SHSN LATER AT
NGT. PSSG OF SUNDAY S/WV SHUD BEGIN A TREND OF IMPROVING
CONDITIONS...WITH HI PRES OVER THE RNG ON SUN NGT,
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
2 PM UPDATE...
FOLLOWED WPC GUIDANCE. CONTINUATION OF THE WET AND UNSETTLED
CONDITIONS IN THE LONG TERM. UPPER TROF OVER NE US MOVES EAST
EARLY IN THE LONG TERM. A RIDGE OF HIGH PRESSURE WITH BRIEF DRY
AIR SUNDAY NIGHT INTO MONDAY BEFORE A SLOW MOVING COLD FRONT
BRINGS RAIN SHOWERS. MUCH LIKE THIS WEEK THE FRONT WAFFLES NORTH
AND SOUTH ACROSS THE AREA TUESDAY TO THURSDAY. LATE THURSDAY
MODELS BRING A STRONG COLD FRONT AND UPPER LEVEL TROF. MODELS
TIMING MAY BE TOO FAST WITH THE DEEP TROF IN THE WEST.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
12Z UPDATE...
WET COLD FRONT IS INBOUND FOR ALL TERMINALS TODAY. SHOWERS ARE
RUNNING AHEAD OF THE FRONT THIS MORNING...AND ALSO WITH THE FRONT
ITSELF INTO AFTERNOON. THOUGH WARM AIR HAS MOVED IN AHEAD OF THE
COLD FRONT ALOFT...UNDER IT THE ATMOSPHERE REMAINS COOL AND VERY
MOIST IN THE LOWER LEVELS. VARIATIONS OF IFR TO LOW END MVFR ARE
EXPECTED AHEAD OF AND WITH THE SHOWERY COLD FRONT. WHILE
NOT EXPLICITLY IN TAFS...AN ISOLATED EMBEDDED THUNDERSTORM IS NOT
OUT OF THE QUESTION...PARTICULARLY KELM-KBGM-KAVP. EAST TO
SOUTHEAST FLOW WITH OCCASIONAL GUSTS 16-22 KTS THROUGH THE MORNING
/LIGHTER AT KELM/ WILL BECOME VARIABLE WITH COLD FRONT MID
AFTERNOON...BEFORE LIGHT NORTHWEST TO WEST TONIGHT. BEHIND COLD
FRONT...PERIOD OF DRIZZLE AND TRAPPED MOISTURE WILL PROBABLY ALLOW
IFR TO PERSIST FOR A TIME. LIGHT FLOW ALREADY BEGINS TO BACK
TOWARDS DAWN...AND DRIER AIR WILL BE TRYING TO MAKE ITS WAY
IN...WHICH SHOULD LEAD TO SOME IMPROVEMENTS. CAVEAT IS THAT WITH
GOOD AMOUNT OF RAIN TODAY...LINGERING MOISTURE COULD CAUSE THINGS
TO LINGER LONGER THAN FORECAST.
.OUTLOOK...
SAT TO SUN NGT...MAINLY VFR BUT PSBL MVFR IN MIXED SHWRS.
MON TO TUE...MVFR IN RAIN.
&&
.HYDROLOGY...
520 AM FRIDAY UPDATE...
MINOR FLOODING FOR A FEW LOCATIONS AS MENTIONED BELOW FOR TODAY INTO
SATURDAY. LARGE AREA OF RAIN WITH SLOW MOVING COLD FRONT WILL MOVE
INTO THE AREA TODAY. THIS WILL YIELD ROUGHLY HALF TO THREE
QUARTERS OF AN INCH OR SO...HIGHEST IN ONEIDA COUNTY AND ALSO
PIKE/WAYNE/SULLIVAN. FOR ONEIDA COUNTY...SOME UNMELTED SNOW AND A
SATURATED GROUND FROM RECENT RAINFALL KEEPS FLOOD WATCH IN EFFECT.
A RIVER WARNING IS ALREADY OUT FOR THE MOHAWK RIVER AND DELTA DAM
BY OUR NEIGHBOR OFFICE IN ALBANY. ALSO...TIOUGHNIOGA RIVER IN
CORTLAND IS RUNNING HIGH AND IS EXPECTED TO CREST NEAR FLOOD STAGE
TONIGHT...SO FLOOD WARNING ISSUED FOR THERE /MINOR FLOODING
EXPECTED/.
WAVERLY-SAYRE ON SUSQUEHANNA WAS EARLIER FORECAST TO CREST NEAR FLOOD
STAGE BUT EXPECTATIONS HAVE DROPPED SOMEWHAT BASED ON LATEST QPF
TRENDS...THUS NO FLOOD WARNING ANTICIPATED THERE AT THIS TIME.
THAT BEING SAID...WHILE NOT TECHNICALLY FLOODING...WATER LEVELS WILL
STILL BE NOTICEABLY ELEVATED FOR MANY AREA STREAMS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR NYZ009-037.
WINTER WEATHER ADVISORY UNTIL 11 AM EDT THIS MORNING FOR
NYZ009-046.
&&
$$
SYNOPSIS...
NEAR TERM...PVN
SHORT TERM...
LONG TERM...TAC
AVIATION...MDP
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS RALEIGH NC
740 AM EDT FRI APR 12 2013
.SYNOPSIS...
A STRONG FRONTAL SYSTEM WILL CROSS THE REGION TODAY. WEAK HIGH
PRESSURE WILL BUILD INTO THE REGION FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 208 AM THURSDAY...
SYNOPTIC PICTURE: LARGE STACKED MID-UPPER LOW OVER IA WOBBLES NNE
THROUGH THE U.P. OF MI/LAKE SUPERIOR INTO ONTARIO THROUGH SATURDAY.
A SHORTWAVE TROUGH OVER GA/ERN TN OVERNIGHT WILL DAMPEN AS IT TRACKS
TO THE NE THROUGH NC THROUGH MIDDAY TODAY. AT THE SURFACE... AN
OCCLUDING FRONT WILL ROTATE UP THROUGH THE CENTRAL APPALACHIANS
TODAY WITH A TRAILING COLD FRONT SWEEPING EASTWARD THROUGH CENTRAL
NC BETWEEN 12Z-21Z. THIS FRONT WILL DISSIPATE OVER THE COASTAL PLAIN
BY 00Z... THEN A SECONDARY COLD FRONT WILL DROP SE THROUGH THE AREA
TONIGHT. WEAK HIGH PRESSURE CURRENTLY OVER THE HIGH PLAINS WILL
BUILD INTO THE WRN CAROLINAS FROM THE WEST ON SATURDAY.
THROUGH TODAY: SEVERE WEATHER THREAT PERSISTS FOR CENTRAL NC BUT
MANY QUESTIONS REMAIN. PROMINENT WELL-ORGANIZED SQUALL LINE FROM SW
VA THROUGH THE WRN CAROLINAS/ERN GA REMAINS RATHER POTENT... AND IS
WELL-SUPPORTED BY STRONG DYNAMIC FORCING FOR ASCENT INCLUDING MID
LEVEL DPVA AND INTENSE UPPER DIVERGENCE ASSOCIATED WITH A STRONG
SRLY JET STREAK OVER MI/IN/IL. BUT CLOUD TOP TEMPS HAVE BEEN
STEADILY WARMING IN THE LAST FEW HOURS... LIKELY DUE IN PART TO THE
SLOWLY WANING FORCING WITH THE WEAKENING WAVE AND JET STREAK. BOTH
THE INSTABILITY (ALBEIT MARGINAL) AND THE WIND FIELD (0-6 KM SHEAR
OF 40-50 KTS) HOWEVER REMAIN SUFFICIENT FOR MAINTENANCE OF THIS
CONVECTIVE LINE. ANOTHER BAND OF STORMS QUICKLY FORMING FROM AROUND
CAE DOWN TOWARD SAV IS IN A POCKET OF LOWER INSTABILITY WITH WEAK
CAPPING... BUT SHOULD PERSIST AND GROW UPSCALE AS IT ENCOUNTERS
BETTER INSTABILITY (MUCAPE NEAR 1000 J/KG) OVER THE SOUTHERN HALF OF
CENTRAL NC. CONVECTION-ALLOWING MODELS TAKE THIS CONVECTION NNE INTO
SOUTH CENTRAL/ERN NC WHILE BEING SLOWLY OVERTAKEN BY THE PRIMARY
SQUALL LINE. WHILE THE WEAKENING DYNAMICS ARE OF CONCERN... AS ARE
THE LOWERING MID LEVEL LAPSE RATES TO UNDER 6 C/KM... MODELS HOLD
ONTO MARGINAL INSTABILITY OF 500-1000 J/KG SBCAPE FOR THE NEXT 6
HOURS WHILE LOW LEVEL SHEAR REMAINS FORMIDABLE AT 35-40 KTS WITH
STRONGLY CURVING HODOGRAPHS ON RAP BUFR SOUNDINGS (ENHANCED BY
BACKING LOW LEVEL WINDS IN RESPONSE TO THE DEEPENING OCCLUDED
SURFACE LOW OVER WV/WRN VA ALONG WITH THE ARRIVAL OF THE 40-50 KT
SWRLY LOW LEVEL JET) TOWARD DAYBREAK. THIS SHOULD BE ENOUGH TO
SUPPORT A THREAT OF A FEW STRONG TO SEVERE CELLS WITH POSSIBLE
ROTATION... EITHER WITHIN THE MAIN SQUALL LINE OR IN THE PRECEDING
BAND... PRIMARILY FROM 06Z-14Z. DAMAGING WINDS AND ISOLATED
TORNADOES CONTINUE AS THE PRIMARY THREATS HERE. A SHORT LULL IN
STORM STRENGTH/ORGANIZATION IS LIKELY TO FOLLOW THIS MORNING WITH
THE DIMINISHING UPPER DIVERGENCE AND EXITING SHORTWAVE TROUGH. BUT
DEVELOPMENT OF ANOTHER LINE OF SCATTERED SHALLOW CONVECTION IS
EXPECTED BY AFTERNOON ALONG THE WEAKENING LEADING SURFACE FRONT...
ON THE LEADING EDGE OF THE INCOMING MID LEVEL DRY PUNCH. DESPITE
WANING LOW LEVEL MASS CONVERGENCE AND A FALLOFF OF LOW LEVEL SHEAR
AS SURFACE WINDS VEER TO SW AND WSW... THE RAP SHOWS SBCAPE
REBOUNDING TO 1000-1500 J/KG EAST OF HIGHWAY 1 THIS AFTERNOON WITH
LOW-MID LEVEL WINDS BECOMING UNIDIRECTIONAL GENERATING STRAIGHT-LINE
HODOGRAPHS. WILL RETAIN SCATTERED SHOWERS AND STORMS THROUGH THE
AFTERNOON IN THE EASTERN CWA... BECOMING MORE PATCHY AND SHALLOW
WITH CONTINUED DRYING ALOFT BY LATE AFTERNOON. HIGHS 77-84 AS
THICKNESSES HOLD IN THE 1375-1385 METER RANGE. STOUT WINDS FROM THE
SOUTH WILL BECOME MORE SSE THIS MORNING BEFORE SHIFTING TO SW BY
AFTERNOON.
FOR TONIGHT/SATURDAY: EXPECT A FEW LINGERING SHOWERS OVER THE
NORTHEAST SECTIONS THROUGH EARLY EVENING ALONG THE LEADING FRONT...
BUT OTHERWISE THE INCOMING DRIER AIR IN THE LOWEST 2-2.5 KM FAVORS A
WEST-TO-EAST CLEARING TREND DURING THE EVENING AS SURFACE WINDS
DIMINISH AND BECOME WEST THEN NW. WITH FALLING THICKNESSES AS THE
SECONDARY FRONT PASSES BY AND DECENT RADIATIONAL COOLING LIKELY...
HAVE NUDGED DOWN LOWS SLIGHTLY TO THE MID 40S TO LOW 50S. WEAK
SURFACE HIGH PRESSURE RIDGING FROM THE WEST AND LIGHT MAINLY
WESTERLY SURFACE FLOW WILL FOLLOW FOR SATURDAY. WE SHOULD SEE A FEW
HIGH CLOUDS STREAK ACROSS THE WRN/NRN SECTIONS EARLY SATURDAY
MORNING AS A WEAK MID LEVEL PERTURBATION MOVES NE OVER THE SRN
APPALACHIANS AND A 100-120 KT JETLET STREAKS BY TO OUR NNW... BUT
ASIDE FROM THIS WE SHOULD SEE PLENTY OF SUNSHINE WITH A FAIRLY DRY
COLUMN AS PW VALUES DROP TO NEAR OR JUST UNDER NORMAL. HIGHS 70-75.
-GIH
&&
.SHORT TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AS OF 230 AM FRIDAY...
WEAK HIGH PRESSURE MOVING OVER THE NORTHEASTERN US WILL EXTEND
SOUTH ACROSS THE CAROLINAS SUNDAY AS SHORTWAVE RIDGING DEVELOPS OVER
THE MID-ATLANTIC STATES AND GREAT LAKES REGION. LOW LEVEL
THICKNESSES SHOULD START OUT AROUND 1350M SUNDAY MORNING...WHICH IS
RIGHT AT NORMAL VALUES...AND HIGHS WILL ACCORDINGLY BE IN THE LOWER
70S MOST EVERYWHERE. A LOW AMPLITUDE SOUTHERN STREAM SHORTWAVE IS
FORECAST TO UNDERCUT THE RIDGE SUNDAY NIGHT AND TRACK EAST ACROSS
THE SOUTHEASTERN US THROUGH MONDAY. THIS WILL LIKELY LEAD TO A
CHANCE OF SHOWERS...MAINLY ACROSS THE SOUTH ON MONDAY BEFORE A MORE
PRONOUNCED MID/UPPER LEVEL RIDGE DEVELOPS BY TUESDAY. THE GFS NOW
SHOWS THE INVERTED COASTAL TROUGH THAT THE ECMWF HAS BEEN SHOWING IN
RECENT RUNS...DELAYING RETURN FLOW DEVELOPMENT AND KEEPING AN
EASTERLY COMPONENT TO THE LOW LEVEL FLOW WITH WEAKER MIXING BOTH
MONDAY AND TUESDAY. BECAUSE OF THIS...HAVE LOWERED HIGHS A COUPLE
OF DEGREES BOTH DAYS...WITH LOW/MID 70S MONDAY AND UPPER 70S
TUESDAY. LOWS IN THE LOWER 50S SUNDAY NIGHT AND MID 50S MONDAY NIGHT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 230 AM FRIDAY...
IN THE EXTENDED PERIOD...THE LONGWAVE PATTERN BECOMES QUITE SIMILAR
TO THE PATTERN OBSERVED THIS WEEK...WITH A RELOADING TROUGH OVER THE
WESTERN US AND RIDGING DOWNSTREAM OVER THE EASTERN US. THIS WILL
LEAD TO A RE-ESTABLISHMENT OF SOUTHERN RETURN FLOW AND TEMPS
CONTINUING TO CLIMB ABOVE NORMAL. THE GFS AND ECMWF THEN SHOW SOME
DISAGREEMENT ON HOW QUICKLY THE SYNOPTIC FRONT WILL TRANSLATE EAST
BY MID TO LATE WEEK. THE GFS SHOWS LESS OF A MID-LEVEL CAP AND MORE
INSTABILITY BY WEDNESDAY...PARTICULARLY OVER THE WESTERN CWA...WITH
THE RIDGE BREAKING DOWN MORE RAPIDLY. PREFER THE DRIER ECMWF WHICH
SEEMS TO FIT BETTER WITH PERSISTENCE AND THE REDEVELOPMENT OF THE
CURRENT PATTERN....KEEPING POPS OUT OF THE FORECAST UNTIL
THURSDAY/FRIDAY WHEN HEIGHTS MAY BEGIN TRULY TO FALL AHEAD A
SHORTWAVE LIFTING THROUGH THE MIDWEST STATES.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 740 AM FRIDAY...
MVFR CIGS WILL DOMINATE THIS MORNING AS A VIGOROUS FRONTAL SYSTEM
MOVES THROUGH CENTRAL NC. MVFR TO BRIEFLY IFR VSBYS ARE POSSIBLE AS
WELL AT RDU/RWI/FAY THROUGH 15Z ACCOMPANYING RAIN AND STORMS.
SURFACE WINDS HAVE BRIEFLY LOWERED TO 8-12 KTS WITH OCCASIONAL GUSTS
TO 15-18 KTS... HOWEVER SURFACE WINDS SHOULD INCREASE ONCE AGAIN BY
17Z AS WE MIX VERTICALLY AND DRAW DOWN 30-40 KT SW WINDS JUST OFF
THE SURFACE. CIGS SHOULD LIFT TO VFR AT GSO/INT BY 14Z AND RDU BY
15Z... BUT MVFR CIGS ARE LIKELY TO HOLD THROUGH MUCH OF THE DAY...
UNTIL 20Z-22Z... AT RWI/FAY. SKIES ARE EXPECTED TO CLEAR OUT AFTER
00Z AT INT/GSO AND AFTER 03Z AT RDU/RWI/FAY WITH WINDS BECOME
WESTERLY AND DECREASING TO UNDER 10 KTS. VFR CONDITIONS WILL HOLD
OVERNIGHT.
LOOKING BEYOND 12Z SATURDAY MORNING... HIGH CONFIDENCE IN VFR
CONDITIONS THROUGH SUNDAY. MVFR TO IFR CONDITIONS ARE POSSIBLE LATE
SUNDAY NIGHT THROUGH MONDAY NIGHT AS ANOTHER STORM SYSTEM MOVES
THROUGH. GRADUAL RETURN TO VFR CONDITIONS TUESDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...HARTFIELD
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
238 AM EDT FRI APR 12 2013
.SYNOPSIS...
A STRONG FRONTAL SYSTEM WILL CROSS THE REGION TODAY. WEAK HIGH
PRESSURE WILL BUILD INTO THE REGION FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 208 AM THURSDAY...
...ISOLATED THREAT FOR SEVERE WEATHER CONTINUES...
SYNOPTIC PICTURE: LARGE STACKED MID-UPPER LOW OVER IA WOBBLES NNE
THROUGH THE U.P. OF MI/LAKE SUPERIOR INTO ONTARIO THROUGH SATURDAY.
A SHORTWAVE TROUGH OVER GA/ERN TN OVERNIGHT WILL DAMPEN AS IT TRACKS
TO THE NE THROUGH NC THROUGH MIDDAY TODAY. AT THE SURFACE... AN
OCCLUDING FRONT WILL ROTATE UP THROUGH THE CENTRAL APPALACHIANS
TODAY WITH A TRAILING COLD FRONT SWEEPING EASTWARD THROUGH CENTRAL
NC BETWEEN 12Z-21Z. THIS FRONT WILL DISSIPATE OVER THE COASTAL PLAIN
BY 00Z... THEN A SECONDARY COLD FRONT WILL DROP SE THROUGH THE AREA
TONIGHT. WEAK HIGH PRESSURE CURRENTLY OVER THE HIGH PLAINS WILL
BUILD INTO THE WRN CAROLINAS FROM THE WEST ON SATURDAY.
THROUGH TODAY: SEVERE WEATHER THREAT PERSISTS FOR CENTRAL NC BUT
MANY QUESTIONS REMAIN. PROMINENT WELL-ORGANIZED SQUALL LINE FROM SW
VA THROUGH THE WRN CAROLINAS/ERN GA REMAINS RATHER POTENT... AND IS
WELL-SUPPORTED BY STRONG DYNAMIC FORCING FOR ASCENT INCLUDING MID
LEVEL DPVA AND INTENSE UPPER DIVERGENCE ASSOCIATED WITH A STRONG
SRLY JET STREAK OVER MI/IN/IL. BUT CLOUD TOP TEMPS HAVE BEEN
STEADILY WARMING IN THE LAST FEW HOURS... LIKELY DUE IN PART TO THE
SLOWLY WANING FORCING WITH THE WEAKENING WAVE AND JET STREAK. BOTH
THE INSTABILITY (ALBEIT MARGINAL) AND THE WIND FIELD (0-6 KM SHEAR
OF 40-50 KTS) HOWEVER REMAIN SUFFICIENT FOR MAINTENANCE OF THIS
CONVECTIVE LINE. ANOTHER BAND OF STORMS QUICKLY FORMING FROM AROUND
CAE DOWN TOWARD SAV IS IN A POCKET OF LOWER INSTABILITY WITH WEAK
CAPPING... BUT SHOULD PERSIST AND GROW UPSCALE AS IT ENCOUNTERS
BETTER INSTABILITY (MUCAPE NEAR 1000 J/KG) OVER THE SOUTHERN HALF OF
CENTRAL NC. CONVECTION-ALLOWING MODELS TAKE THIS CONVECTION NNE INTO
SOUTH CENTRAL/ERN NC WHILE BEING SLOWLY OVERTAKEN BY THE PRIMARY
SQUALL LINE. WHILE THE WEAKENING DYNAMICS ARE OF CONCERN... AS ARE
THE LOWERING MID LEVEL LAPSE RATES TO UNDER 6 C/KM... MODELS HOLD
ONTO MARGINAL INSTABILITY OF 500-1000 J/KG SBCAPE FOR THE NEXT 6
HOURS WHILE LOW LEVEL SHEAR REMAINS FORMIDABLE AT 35-40 KTS WITH
STRONGLY CURVING HODOGRAPHS ON RAP BUFR SOUNDINGS (ENHANCED BY
BACKING LOW LEVEL WINDS IN RESPONSE TO THE DEEPENING OCCLUDED
SURFACE LOW OVER WV/WRN VA ALONG WITH THE ARRIVAL OF THE 40-50 KT
SWRLY LOW LEVEL JET) TOWARD DAYBREAK. THIS SHOULD BE ENOUGH TO
SUPPORT A THREAT OF A FEW STRONG TO SEVERE CELLS WITH POSSIBLE
ROTATION... EITHER WITHIN THE MAIN SQUALL LINE OR IN THE PRECEDING
BAND... PRIMARILY FROM 06Z-14Z. DAMAGING WINDS AND ISOLATED
TORNADOES CONTINUE AS THE PRIMARY THREATS HERE. A SHORT LULL IN
STORM STRENGTH/ORGANIZATION IS LIKELY TO FOLLOW THIS MORNING WITH
THE DIMINISHING UPPER DIVERGENCE AND EXITING SHORTWAVE TROUGH. BUT
DEVELOPMENT OF ANOTHER LINE OF SCATTERED SHALLOW CONVECTION IS
EXPECTED BY AFTERNOON ALONG THE WEAKENING LEADING SURFACE FRONT...
ON THE LEADING EDGE OF THE INCOMING MID LEVEL DRY PUNCH. DESPITE
WANING LOW LEVEL MASS CONVERGENCE AND A FALLOFF OF LOW LEVEL SHEAR
AS SURFACE WINDS VEER TO SW AND WSW... THE RAP SHOWS SBCAPE
REBOUNDING TO 1000-1500 J/KG EAST OF HIGHWAY 1 THIS AFTERNOON WITH
LOW-MID LEVEL WINDS BECOMING UNIDIRECTIONAL GENERATING STRAIGHT-LINE
HODOGRAPHS. WILL RETAIN SCATTERED SHOWERS AND STORMS THROUGH THE
AFTERNOON IN THE EASTERN CWA... BECOMING MORE PATCHY AND SHALLOW
WITH CONTINUED DRYING ALOFT BY LATE AFTERNOON. HIGHS 77-84 AS
THICKNESSES HOLD IN THE 1375-1385 METER RANGE. STOUT WINDS FROM THE
SOUTH WILL BECOME MORE SSE THIS MORNING BEFORE SHIFTING TO SW BY
AFTERNOON.
FOR TONIGHT/SATURDAY: EXPECT A FEW LINGERING SHOWERS OVER THE
NORTHEAST SECTIONS THROUGH EARLY EVENING ALONG THE LEADING FRONT...
BUT OTHERWISE THE INCOMING DRIER AIR IN THE LOWEST 2-2.5 KM FAVORS A
WEST-TO-EAST CLEARING TREND DURING THE EVENING AS SURFACE WINDS
DIMINISH AND BECOME WEST THEN NW. WITH FALLING THICKNESSES AS THE
SECONDARY FRONT PASSES BY AND DECENT RADIATIONAL COOLING LIKELY...
HAVE NUDGED DOWN LOWS SLIGHTLY TO THE MID 40S TO LOW 50S. WEAK
SURFACE HIGH PRESSURE RIDGING FROM THE WEST AND LIGHT MAINLY
WESTERLY SURFACE FLOW WILL FOLLOW FOR SATURDAY. WE SHOULD SEE A FEW
HIGH CLOUDS STREAK ACROSS THE WRN/NRN SECTIONS EARLY SATURDAY
MORNING AS A WEAK MID LEVEL PERTURBATION MOVES NE OVER THE SRN
APPALACHIANS AND A 100-120 KT JETLET STREAKS BY TO OUR NNW... BUT
ASIDE FROM THIS WE SHOULD SEE PLENTY OF SUNSHINE WITH A FAIRLY DRY
COLUMN AS PW VALUES DROP TO NEAR OR JUST UNDER NORMAL. HIGHS 70-75.
-GIH
&&
.SHORT TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AS OF 230 AM FRIDAY...
WEAK HIGH PRESSURE MOVING OVER THE NORTHEASTERN US WILL EXTEND
SOUTH ACROSS THE CAROLINAS SUNDAY AS SHORTWAVE RIDGING DEVELOPS OVER
THE MID-ATLANTIC STATES AND GREAT LAKES REGION. LOW LEVEL
THICKNESSES SHOULD START OUT AROUND 1350M SUNDAY MORNING...WHICH IS
RIGHT AT NORMAL VALUES...AND HIGHS WILL ACCORDINGLY BE IN THE LOWER
70S MOST EVERYWHERE. A LOW AMPLITUDE SOUTHERN STREAM SHORTWAVE IS
FORECAST TO UNDERCUT THE RIDGE SUNDAY NIGHT AND TRACK EAST ACROSS
THE SOUTHEASTERN US THROUGH MONDAY. THIS WILL LIKELY LEAD TO A
CHANCE OF SHOWERS...MAINLY ACROSS THE SOUTH ON MONDAY BEFORE A MORE
PRONOUNCED MID/UPPER LEVEL RIDGE DEVELOPS BY TUESDAY. THE GFS NOW
SHOWS THE INVERTED COASTAL TROUGH THAT THE ECMWF HAS BEEN SHOWING IN
RECENT RUNS...DELAYING RETURN FLOW DEVELOPMENT AND KEEPING AN
EASTERLY COMPONENT TO THE LOW LEVEL FLOW WITH WEAKER MIXING BOTH
MONDAY AND TUESDAY. BECAUSE OF THIS...HAVE LOWERED HIGHS A COUPLE
OF DEGREES BOTH DAYS...WITH LOW/MID 70S MONDAY AND UPPER 70S
TUESDAY. LOWS IN THE LOWER 50S SUNDAY NIGHT AND MID 50S MONDAY NIGHT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 230 AM FRIDAY...
IN THE EXTENDED PERIOD...THE LONGWAVE PATTERN BECOMES QUITE SIMILAR
TO THE PATTERN OBSERVED THIS WEEK...WITH A RELOADING TROUGH OVER THE
WESTERN US AND RIDGING DOWNSTREAM OVER THE EASTERN US. THIS WILL
LEAD TO A RE-ESTABLISHMENT OF SOUTHERN RETURN FLOW AND TEMPS
CONTINUING TO CLIMB ABOVE NORMAL. THE GFS AND ECMWF THEN SHOW SOME
DISAGREEMENT ON HOW QUICKLY THE SYNOPTIC FRONT WILL TRANSLATE EAST
BY MID TO LATE WEEK. THE GFS SHOWS LESS OF A MID-LEVEL CAP AND MORE
INSTABILITY BY WEDNESDAY...PARTICULARLY OVER THE WESTERN CWA...WITH
THE RIDGE BREAKING DOWN MORE RAPIDLY. PREFER THE DRIER ECMWF WHICH
SEEMS TO FIT BETTER WITH PERSISTENCE AND THE REDEVELOPMENT OF THE
CURRENT PATTERN....KEEPING POPS OUT OF THE FORECAST UNTIL
THURSDAY/FRIDAY WHEN HEIGHTS MAY BEGIN TRULY TO FALL AHEAD A
SHORTWAVE LIFTING THROUGH THE MIDWEST STATES.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 200 AM FRIDAY...
MULTIPLE BANDS OF SHOWERS AND THUNDERSTORMS WILL MOVE THROUGH THE
AREA OVERNIGHT IN ADVANCE OF AN UPPER LEVEL WAVE AND A SLOW MOVING
COLD FRONT APPROACHING FROM THE WEST. EXPECT PRIMARILY MVFR CEILINGS
WITH THE POTENTIAL FOR REDUCED IFR VISIBILITIES IN HEAVY RAIN.
STRONG THUNDERSTORM WIND GUSTS WILL ALSO BE POSSIBLE WITHIN THE
STRONGEST STORMS. THE STORMS WILL IMPACT WESTERN PORTIONS OF THE
FORECAST AREA (KGSO, KINT) BETWEEN 06-12Z AND THEN LOCATIONS FURTHER
EAST BETWEEN 09-15Z.
IN THE WAKE OF THE EXITING LINE OF STORMS FRIDAY MORNING...
STRONG DAYTIME HEATING SHOULD ALLOW FOR ANY SUB-VFR CEILINGS
TO LIFT TO VFR BY MIDDAY. A THIRD BAND OF SHOWERS AND STORM
COULD DEVELOP ACROSS THE AREA DURING THE AFTERNOON AS THE COLD
FRONT FINALLY PUSHES EAST THROUGH THE AREA...ESPECIALLY FROM
RDU EASTWARD. CONFIDENCE IN OCCURRENCE AND LOCATION IS RATHER LOW AT
THIS TIME AND WILL INCLUDE VCSH FOR NOW.
BREEZY CONDITIONS WILL CONTINUE THROUGHOUT MUCH OF THE PERIOD WITH
SOUTHERLY WINDS BECOME SOUTHWESTERLY FRIDAY AFTERNOON...WITH FREQUENT
GUSTS UP TO 20-25 KNOTS UNTIL FRONTAL PASSAGE LATE FRIDAY
AFTERNOON/EARLY FRIDAY EVENING.
OUTLOOK...VFR CONDITIONS WILL DOMINATE THROUGH THE WEEKEND AS HIGH
PRESSURE TAKES OVER. ANOTHER SYSTEM COULD BRING ANOTHER ROUND OF
ADVERSE AVIATION CONDITIONS TO THE REGION EARLY NEXT WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...HARTFIELD
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
230 AM EDT FRI APR 12 2013
.SYNOPSIS...
A STRONG FRONTAL SYSTEM WILL CROSS THE REGION TODAY. WEAK HIGH
PRESSURE WILL BUILD INTO THE REGION FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 208 AM THURSDAY...
...ISOLATED THREAT FOR SEVERE WEATHER CONTINUES...
SYNOPTIC PICTURE: LARGE STACKED MID-UPPER LOW OVER IA WOBBLES NNE
THROUGH THE U.P. OF MI/LAKE SUPERIOR INTO ONTARIO THROUGH SATURDAY.
A SHORTWAVE TROUGH OVER GA/ERN TN OVERNIGHT WILL DAMPEN AS IT TRACKS
TO THE NE THROUGH NC THROUGH MIDDAY TODAY. AT THE SURFACE... AN
OCCLUDING FRONT WILL ROTATE UP THROUGH THE CENTRAL APPALACHIANS
TODAY WITH A TRAILING COLD FRONT SWEEPING EASTWARD THROUGH CENTRAL
NC BETWEEN 12Z-21Z. THIS FRONT WILL DISSIPATE OVER THE COASTAL PLAIN
BY 00Z... THEN A SECONDARY COLD FRONT WILL DROP SE THROUGH THE AREA
TONIGHT. WEAK HIGH PRESSURE CURRENTLY OVER THE HIGH PLAINS WILL
BUILD INTO THE WRN CAROLINAS FROM THE WEST ON SATURDAY.
THROUGH TODAY: SEVERE WEATHER THREAT PERSISTS FOR CENTRAL NC BUT
MANY QUESTIONS REMAIN. PROMINENT WELL-ORGANIZED SQUALL LINE FROM SW
VA THROUGH THE WRN CAROLINAS/ERN GA REMAINS RATHER POTENT... AND IS
WELL-SUPPORTED BY STRONG DYNAMIC FORCING FOR ASCENT INCLUDING MID
LEVEL DPVA AND INTENSE UPPER DIVERGENCE ASSOCIATED WITH A STRONG
SRLY JET STREAK OVER MI/IN/IL. BUT CLOUD TOP TEMPS HAVE BEEN
STEADILY WARMING IN THE LAST FEW HOURS... LIKELY DUE IN PART TO THE
SLOWLY WANING FORCING WITH THE WEAKENING WAVE AND JET STREAK. BOTH
THE INSTABILITY (ALBEIT MARGINAL) AND THE WIND FIELD (0-6 KM SHEAR
OF 40-50 KTS) HOWEVER REMAIN SUFFICIENT FOR MAINTENANCE OF THIS
CONVECTIVE LINE. ANOTHER BAND OF STORMS QUICKLY FORMING FROM AROUND
CAE DOWN TOWARD SAV IS IN A POCKET OF LOWER INSTABILITY WITH WEAK
CAPPING... BUT SHOULD PERSIST AND GROW UPSCALE AS IT ENCOUNTERS
BETTER INSTABILITY (MUCAPE NEAR 1000 J/KG) OVER THE SOUTHERN HALF OF
CENTRAL NC. CONVECTION-ALLOWING MODELS TAKE THIS CONVECTION NNE INTO
SOUTH CENTRAL/ERN NC WHILE BEING SLOWLY OVERTAKEN BY THE PRIMARY
SQUALL LINE. WHILE THE WEAKENING DYNAMICS ARE OF CONCERN... AS ARE
THE LOWERING MID LEVEL LAPSE RATES TO UNDER 6 C/KM... MODELS HOLD
ONTO MARGINAL INSTABILITY OF 500-1000 J/KG SBCAPE FOR THE NEXT 6
HOURS WHILE LOW LEVEL SHEAR REMAINS FORMIDABLE AT 35-40 KTS WITH
STRONGLY CURVING HODOGRAPHS ON RAP BUFR SOUNDINGS (ENHANCED BY
BACKING LOW LEVEL WINDS IN RESPONSE TO THE DEEPENING OCCLUDED
SURFACE LOW OVER WV/WRN VA ALONG WITH THE ARRIVAL OF THE 40-50 KT
SWRLY LOW LEVEL JET) TOWARD DAYBREAK. THIS SHOULD BE ENOUGH TO
SUPPORT A THREAT OF A FEW STRONG TO SEVERE CELLS WITH POSSIBLE
ROTATION... EITHER WITHIN THE MAIN SQUALL LINE OR IN THE PRECEDING
BAND... PRIMARILY FROM 06Z-14Z. DAMAGING WINDS AND ISOLATED
TORNADOES CONTINUE AS THE PRIMARY THREATS HERE. A SHORT LULL IN
STORM STRENGTH/ORGANIZATION IS LIKELY TO FOLLOW THIS MORNING WITH
THE DIMINISHING UPPER DIVERGENCE AND EXITING SHORTWAVE TROUGH. BUT
DEVELOPMENT OF ANOTHER LINE OF SCATTERED SHALLOW CONVECTION IS
EXPECTED BY AFTERNOON ALONG THE WEAKENING LEADING SURFACE FRONT...
ON THE LEADING EDGE OF THE INCOMING MID LEVEL DRY PUNCH. DESPITE
WANING LOW LEVEL MASS CONVERGENCE AND A FALLOFF OF LOW LEVEL SHEAR
AS SURFACE WINDS VEER TO SW AND WSW... THE RAP SHOWS SBCAPE
REBOUNDING TO 1000-1500 J/KG EAST OF HIGHWAY 1 THIS AFTERNOON WITH
LOW-MID LEVEL WINDS BECOMING UNIDIRECTIONAL GENERATING STRAIGHT-LINE
HODOGRAPHS. WILL RETAIN SCATTERED SHOWERS AND STORMS THROUGH THE
AFTERNOON IN THE EASTERN CWA... BECOMING MORE PATCHY AND SHALLOW
WITH CONTINUED DRYING ALOFT BY LATE AFTERNOON. HIGHS 77-84 AS
THICKNESSES HOLD IN THE 1375-1385 METER RANGE. -GIH
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 230 AM FRIDAY...
WEAK HIGH PRESSURE MOVING OVER THE NORTHEASTERN US WILL EXTEND
SOUTH ACROSS THE CAROLINAS SUNDAY AS SHORTWAVE RIDGING DEVELOPS OVER
THE MID-ATLANTIC STATES AND GREAT LAKES REGION. LOW LEVEL
THICKNESSES SHOULD START OUT AROUND 1350M SUNDAY MORNING...WHICH IS
RIGHT AT NORMAL VALUES...AND HIGHS WILL ACCORDINGLY BE IN THE LOWER
70S MOST EVERYWHERE. A LOW AMPLITUDE SOUTHERN STREAM SHORTWAVE IS
FORECAST TO UNDERCUT THE RIDGE SUNDAY NIGHT AND TRACK EAST ACROSS
THE SOUTHEASTERN US THROUGH MONDAY. THIS WILL LIKELY LEAD TO A
CHANCE OF SHOWERS...MAINLY ACROSS THE SOUTH ON MONDAY BEFORE A MORE
PRONOUNCED MID/UPPER LEVEL RIDGE DEVELOPS BY TUESDAY. THE GFS NOW
SHOWS THE INVERTED COASTAL TROUGH THAT THE ECMWF HAS BEEN SHOWING IN
RECENT RUNS...DELAYING RETURN FLOW DEVELOPMENT AND KEEPING AN
EASTERLY COMPONENT TO THE LOW LEVEL FLOW WITH WEAKER MIXING BOTH
MONDAY AND TUESDAY. BECAUSE OF THIS...HAVE LOWERED HIGHS A COUPLE
OF DEGREES BOTH DAYS...WITH LOW/MID 70S MONDAY AND UPPER 70S
TUESDAY. LOWS IN THE LOWER 50S SUNDAY NIGHT AND MID 50S MONDAY NIGHT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 230 AM FRIDAY...
IN THE EXTENDED PERIOD...THE LONGWAVE PATTERN BECOMES QUITE SIMILAR
TO THE PATTERN OBSERVED THIS WEEK...WITH A RELOADING TROUGH OVER THE
WESTERN US AND RIDGING DOWNSTREAM OVER THE EASTERN US. THIS WILL
LEAD TO A RE-ESTABLISHMENT OF SOUTHERN RETURN FLOW AND TEMPS
CONTINUING TO CLIMB ABOVE NORMAL. THE GFS AND ECMWF THEN SHOW SOME
DISAGREEMENT ON HOW QUICKLY THE SYNOPTIC FRONT WILL TRANSLATE EAST
BY MID TO LATE WEEK. THE GFS SHOWS LESS OF A MID-LEVEL CAP AND MORE
INSTABILITY BY WEDNESDAY...PARTICULARLY OVER THE WESTERN CWA...WITH
THE RIDGE BREAKING DOWN MORE RAPIDLY. PREFER THE DRIER ECMWF WHICH
SEEMS TO FIT BETTER WITH PERSISTENCE AND THE REDEVELOPMENT OF THE
CURRENT PATTERN....KEEPING POPS OUT OF THE FORECAST UNTIL
THURSDAY/FRIDAY WHEN HEIGHTS MAY BEGIN TRULY TO FALL AHEAD A
SHORTWAVE LIFTING THROUGH THE MIDWEST STATES.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 200 AM FRIDAY...
MULTIPLE BANDS OF SHOWERS AND THUNDERSTORMS WILL MOVE THROUGH THE
AREA OVERNIGHT IN ADVANCE OF AN UPPER LEVEL WAVE AND A SLOW MOVING
COLD FRONT APPROACHING FROM THE WEST. EXPECT PRIMARILY MVFR CEILINGS
WITH THE POTENTIAL FOR REDUCED IFR VISIBILITIES IN HEAVY RAIN.
STRONG THUNDERSTORM WIND GUSTS WILL ALSO BE POSSIBLE WITHIN THE
STRONGEST STORMS. THE STORMS WILL IMPACT WESTERN PORTIONS OF THE
FORECAST AREA (KGSO, KINT) BETWEEN 06-12Z AND THEN LOCATIONS FURTHER
EAST BETWEEN 09-15Z.
IN THE WAKE OF THE EXITING LINE OF STORMS FRIDAY MORNING...
STRONG DAYTIME HEATING SHOULD ALLOW FOR ANY SUB-VFR CEILINGS
TO LIFT TO VFR BY MIDDAY. A THIRD BAND OF SHOWERS AND STORM
COULD DEVELOP ACROSS THE AREA DURING THE AFTERNOON AS THE COLD
FRONT FINALLY PUSHES EAST THROUGH THE AREA...ESPECIALLY FROM
RDU EASTWARD. CONFIDENCE IN OCCURRENCE AND LOCATION IS RATHER LOW AT
THIS TIME AND WILL INCLUDE VCSH FOR NOW.
BREEZY CONDITIONS WILL CONTINUE THROUGHOUT MUCH OF THE PERIOD WITH
SOUTHERLY WINDS BECOME SOUTHWESTERLY FRIDAY AFTERNOON...WITH FREQUENT
GUSTS UP TO 20-25 KNOTS UNTIL FRONTAL PASSAGE LATE FRIDAY
AFTERNOON/EARLY FRIDAY EVENING.
OUTLOOK...VFR CONDITIONS WILL DOMINATE THROUGH THE WEEKEND AS HIGH
PRESSURE TAKES OVER. ANOTHER SYSTEM COULD BRING ANOTHER ROUND OF
ADVERSE AVIATION CONDITIONS TO THE REGION EARLY NEXT WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...HARTFIELD
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
208 AM EDT FRI APR 12 2013
.SYNOPSIS...
A STRONG FRONTAL SYSTEM WILL CROSS THE REGION TODAY. WEAK HIGH
PRESSURE WILL BUILD INTO THE REGION FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 208 AM THURSDAY...
...ISOLATED THREAT FOR SEVERE WEATHER CONTINUES...
SYNOPTIC PICTURE: LARGE STACKED MID-UPPER LOW OVER IA WOBBLES NNE
THROUGH THE U.P. OF MI/LAKE SUPERIOR INTO ONTARIO THROUGH SATURDAY.
A SHORTWAVE TROUGH OVER GA/ERN TN OVERNIGHT WILL DAMPEN AS IT TRACKS
TO THE NE THROUGH NC THROUGH MIDDAY TODAY. AT THE SURFACE... AN
OCCLUDING FRONT WILL ROTATE UP THROUGH THE CENTRAL APPALACHIANS
TODAY WITH A TRAILING COLD FRONT SWEEPING EASTWARD THROUGH CENTRAL
NC BETWEEN 12Z-21Z. THIS FRONT WILL DISSIPATE OVER THE COASTAL PLAIN
BY 00Z... THEN A SECONDARY COLD FRONT WILL DROP SE THROUGH THE AREA
TONIGHT. WEAK HIGH PRESSURE CURRENTLY OVER THE HIGH PLAINS WILL
BUILD INTO THE WRN CAROLINAS FROM THE WEST ON SATURDAY.
THROUGH TODAY: SEVERE WEATHER THREAT PERSISTS FOR CENTRAL NC BUT
MANY QUESTIONS REMAIN. PROMINENT WELL-ORGANIZED SQUALL LINE FROM SW
VA THROUGH THE WRN CAROLINAS/ERN GA REMAINS RATHER POTENT... AND IS
WELL-SUPPORTED BY STRONG DYNAMIC FORCING FOR ASCENT INCLUDING MID
LEVEL DPVA AND INTENSE UPPER DIVERGENCE ASSOCIATED WITH A STRONG
SRLY JET STREAK OVER MI/IN/IL. BUT CLOUD TOP TEMPS HAVE BEEN
STEADILY WARMING IN THE LAST FEW HOURS... LIKELY DUE IN PART TO THE
SLOWLY WANING FORCING WITH THE WEAKENING WAVE AND JET STREAK. BOTH
THE INSTABILITY (ALBEIT MARGINAL) AND THE WIND FIELD (0-6 KM SHEAR
OF 40-50 KTS) HOWEVER REMAIN SUFFICIENT FOR MAINTENANCE OF THIS
CONVECTIVE LINE. ANOTHER BAND OF STORMS QUICKLY FORMING FROM AROUND
CAE DOWN TOWARD SAV IS IN A POCKET OF LOWER INSTABILITY WITH WEAK
CAPPING... BUT SHOULD PERSIST AND GROW UPSCALE AS IT ENCOUNTERS
BETTER INSTABILITY (MUCAPE NEAR 1000 J/KG) OVER THE SOUTHERN HALF OF
CENTRAL NC. CONVECTION-ALLOWING MODELS TAKE THIS CONVECTION NNE INTO
SOUTH CENTRAL/ERN NC WHILE BEING SLOWLY OVERTAKEN BY THE PRIMARY
SQUALL LINE. WHILE THE WEAKENING DYNAMICS ARE OF CONCERN... AS ARE
THE LOWERING MID LEVEL LAPSE RATES TO UNDER 6 C/KM... MODELS HOLD
ONTO MARGINAL INSTABILITY OF 500-1000 J/KG SBCAPE FOR THE NEXT 6
HOURS WHILE LOW LEVEL SHEAR REMAINS FORMIDABLE AT 35-40 KTS WITH
STRONGLY CURVING HODOGRAPHS ON RAP BUFR SOUNDINGS (ENHANCED BY
BACKING LOW LEVEL WINDS IN RESPONSE TO THE DEEPENING OCCLUDED
SURFACE LOW OVER WV/WRN VA ALONG WITH THE ARRIVAL OF THE 40-50 KT
SWRLY LOW LEVEL JET) TOWARD DAYBREAK. THIS SHOULD BE ENOUGH TO
SUPPORT A THREAT OF A FEW STRONG TO SEVERE CELLS WITH POSSIBLE
ROTATION... EITHER WITHIN THE MAIN SQUALL LINE OR IN THE PRECEDING
BAND... PRIMARILY FROM 06Z-14Z. DAMAGING WINDS AND ISOLATED
TORNADOES CONTINUE AS THE PRIMARY THREATS HERE. A SHORT LULL IN
STORM STRENGTH/ORGANIZATION IS LIKELY TO FOLLOW THIS MORNING WITH
THE DIMINISHING UPPER DIVERGENCE AND EXITING SHORTWAVE TROUGH. BUT
DEVELOPMENT OF ANOTHER LINE OF SCATTERED SHALLOW CONVECTION IS
EXPECTED BY AFTERNOON ALONG THE WEAKENING LEADING SURFACE FRONT...
ON THE LEADING EDGE OF THE INCOMING MID LEVEL DRY PUNCH. DESPITE
WANING LOW LEVEL MASS CONVERGENCE AND A FALLOFF OF LOW LEVEL SHEAR
AS SURFACE WINDS VEER TO SW AND WSW... THE RAP SHOWS SBCAPE
REBOUNDING TO 1000-1500 J/KG EAST OF HIGHWAY 1 THIS AFTERNOON WITH
LOW-MID LEVEL WINDS BECOMING UNIDIRECTIONAL GENERATING STRAIGHT-LINE
HODOGRAPHS. WILL RETAIN SCATTERED SHOWERS AND STORMS THROUGH THE
AFTERNOON IN THE EASTERN CWA... BECOMING MORE PATCHY AND SHALLOW
WITH CONTINUED DRYING ALOFT BY LATE AFTERNOON. HIGHS 77-84 AS
THICKNESSES HOLD IN THE 1375-1385 METER RANGE. -GIH
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 250 PM THURSDAY...
THE COLD FRONT CLEARS THE COAST FRIDAY NIGHT WITH DRY WESTERLY FLOW
AND MILD HIGH PRESSURE BUILDING IN FOR THE WEEKEND. SKIES WILL BE
MOSTLY CLEAR WITH LITTLE IN THE WAY OF SENSIBLE WEATHER...MAINLY
JUST A TEMPERATURE FORECAST THROUGH THE PERIOD. THE COOLER AIRMASS
SETTLING INTO PLACE WILL BE EVIDENT SATURDAY MORNING WITH MORNING
MINIMUMS IN THE MID 40S WEST TO LOWER 50S EAST. PLENTIFUL SUNSHINE
ON BOTH SATURDAY AND SUNDAY WILL ALLOW HIGHS TO REACH A SEASONABLE
RANGE OF 70 TO 75. MEANWHILE...BEST RADIATIONAL CONDITIONS ARE
EXPECTED SATURDAY NIGHT DUE TO CALM WINDS...AND MINS SUNDAY MORNING
WILL BOTTOM OUT IN THE LOW AND MID 40S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 250 PM THURSDAY...
THE SURFACE HIGH PRESSURE MIGRATES OFFSHORE SUNDAY NIGHT...WITH
MOISTURE ADVECTION UNDERWAY AS SOUTHERLY LOW LEVEL FLOW INCREASES TO
20 TO 25 KNOTS. A WEAK SHORT WAVE WILL MOVE ALONG THE GULF COAST
SUNDAY NIGHT AS WELL...UTILIZING THE INCREASING MOISTURE TO PRODUCE
INCREASING CLOUD COVERAGE AND A CHANCE OF SHOWERS ACROSS THE AREA ON
MONDAY INTO MONDAY NIGHT. AT THIS POINT THE CHANCE FOR THUNDER LOOKS
MINIMAL DUE TO WEAK INSTABILITY AND LACK OF FOCUSED FORCING. MINS
SUNDAY NIGHT WILL BE MILD DUE TO THE CLOUDINESS AND SOUTHERLY
FLOW...IN THE LOWER 50S...WHILE HIGHS MONDAY WILL BE INHIBITED BY
THE CLOUDINESS AND TOP OUT IN THE MID TO PERHAPS UPPER 70S DESPITE
THE WARM START.
LOW AMPLITUDE RIDGING AND LOW LEVEL SOUTHERLY FLOW WILL PRODUCE A
WARMING TREND TUESDAY AND WEDNESDAY...WITH CAPPING ALOFT INHIBITING
CONVECTION TO ONLY ISOLATED AFTERNOON SHOWERS AS WE WARM INTO UPPER
70S TO LOWER 80S BOTH DAYS. TIMING OF A LATE WEEK COLD FRONT
APPROACHING FROM THE WEST IS IN QUESTION AS IT WILL DEPEND ON THE
RIDGE SHIFTING OFFSHORE RATHER QUICKLY...WILL INTRODUCE THURSDAYS
FORECAST WITH SMALL CHANCES OF SHOWERS IN THE WEST PENDING CONSENSUS
WITH LATER MODEL RUNS. HIGHS THURSDAY WILL BE AT LEAST IN THE 75 TO
80 DEGREE RANGE GIVEN WE WILL BE IN THE WARM SECTOR AHEAD OF THE
FRONT...AND COULD EASILY BE IN THE 80 TO 85 RANGE IF UPPER RIDGING
DELAYS THE FRONTS PROGRESS.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 200 AM FRIDAY...
MULTIPLE BANDS OF SHOWERS AND THUNDERSTORMS WILL MOVE THROUGH THE
AREA OVERNIGHT IN ADVANCE OF AN UPPER LEVEL WAVE AND A SLOW MOVING
COLD FRONT APPROACHING FROM THE WEST. EXPECT PRIMARILY MVFR CEILINGS
WITH THE POTENTIAL FOR REDUCED IFR VISIBILITIES IN HEAVY RAIN.
STRONG THUNDERSTORM WIND GUSTS WILL ALSO BE POSSIBLE WITHIN THE
STRONGEST STORMS. THE STORMS WILL IMPACT WESTERN PORTIONS OF THE
FORECAST AREA (KGSO, KINT) BETWEEN 06-12Z AND THEN LOCATIONS FURTHER
EAST BETWEEN 09-15Z.
IN THE WAKE OF THE EXITING LINE OF STORMS FRIDAY MORNING...
STRONG DAYTIME HEATING SHOULD ALLOW FOR ANY SUB-VFR CEILINGS
TO LIFT TO VFR BY MIDDAY. A THIRD BAND OF SHOWERS AND STORM
COULD DEVELOP ACROSS THE AREA DURING THE AFTERNOON AS THE COLD
FRONT FINALLY PUSHES EAST THROUGH THE AREA...ESPECIALLY FROM
RDU EASTWARD. CONFIDENCE IN OCCURRENCE AND LOCATION IS RATHER LOW AT
THIS TIME AND WILL INCLUDE VCSH FOR NOW.
BREEZY CONDITIONS WILL CONTINUE THROUGHOUT MUCH OF THE PERIOD WITH
SOUTHERLY WINDS BECOME SOUTHWESTERLY FRIDAY AFTERNOON...WITH FREQUENT
GUSTS UP TO 20-25 KNOTS UNTIL FRONTAL PASSAGE LATE FRIDAY
AFTERNOON/EARLY FRIDAY EVENING.
OUTLOOK...VFR CONDITIONS WILL DOMINATE THROUGH THE WEEKEND AS HIGH
PRESSURE TAKES OVER. ANOTHER SYSTEM COULD BRING ANOTHER ROUND OF
ADVERSE AVIATION CONDITIONS TO THE REGION EARLY NEXT WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...HARTFIELD
SHORT TERM...MLM
LONG TERM...MLM
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
959 AM CDT FRI APR 12 2013
.UPDATE...
ISSUED AT 958 AM CDT FRI APR 12 2013
BUMPED UP POPS FOR THIS MORNING AS LIGHT SNOW HAS CONTINUED TO
SPREAD ACROSS THE CWA. THINK THAT ACCUMULATIONS WILL REMAIN
LIGHT...GENERALLY UNDER AN INCH OVER ALL BUT THE FAR NORTHEASTERN
COUNTIES. FREEZING DRIZZLE HAS CONTINUED ACROSS THE VALLEY CITY
AREA SO KEPT A PATCHY MENTION IN THAT AREA FOR THE NEXT FEW HOURS.
HOWEVER...THINK THAT THE DRY LAYER ALOFT WILL CONTINUE TO SATURATE
AND WE SHOULD BE ALL SNOW BY THIS AFTERNOON. THE NORTHEASTERN
COUNTIES WILL HAVE TO BE WATCHED IN CASE MORE SNOW ACCUMULATES
THAN EXPECTED...BUT FOR NOW WILL JUST KEEP AN EYE ON IT AND NOT
INCLUDE HEADLINES.
UPDATE ISSUED AT 700 AM CDT FRI APR 12 2013
BANDS OF SNOW SHOWERS CONTINUE TO ROTATE FROM EAST TO WEST THROUGH
THE REGION...WITH THE STEADIER SNOW ACROSS THE FAR EASTERN FA.
THIS IS IN LINE WITH THE EXPECTED FORECAST.
GETTING REPORTS OF FREEZING DRIZZLE FROM COOPERSTOWN TO VALLEY
CITY. RAP 10Z SOUNDING INDICATES A DRY LAYER FROM 700MB-
500MB...WITH THE SATURATED LAYER BELOW -8C TO -10C. THIS SOUNDING
IS NOT AN IDEAL SUPERCOOLED WATER DROPLET SCENARIO...BUT IT IS
OCCURRING. THE RAP DOES SATURATE THE 700MB-500MB LAYER AFTER
15Z...WHICH SHOULD ALLOW THE P-TYPE TO BE ALL SNOW AGAIN. WILL
INCLUDE FZDZ IN THE AREA UNTIL 15Z...AND ISSUE A SPS (A FEW CARS
REPORTED TO BE IN DITCH ALONG I-94).
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 355 AM CDT FRI APR 12 2013
THE UPPER LEVEL LOW WILL CONTINUE TO PROPAGATE NORTHEAST THROUGH
THE PERIOD. MODELS ARE IN GOOD AGREEMENT AND WILL USE A BLEND FOR
DETAILS. THE MAIN CHALLENGE FOR TODAY WILL BE SNOW CHANCES AND
AMOUNTS. UPPER LEVEL ENERGY CONTINUES TO ROTATE AROUND THE UPPER
LEVEL LOW...AND ANOTHER SHOT OF FORCING/MOISTURE IS HEADED TOWARD
THE EASTERN FA FOR THE MORNING HOURS. GIVEN UPSTREAM
OBSERVATIONS...RADAR IMAGERY...AND MODEL GUIDANCE...EXPECT AN
ADDITIONAL 2-4 INCHES OF SNOW ACROSS THE FAR EASTERN FA. SCATTERED
SNOW SHOWERS AND AN INCH OR TWO OF SNOW WILL OCCUR ALONG AND WEST
OF THE VALLEY. CLOUDS WILL HOLD STRONG TODAY...AND MAX TEMPS
SHOULD BE SIMILAR TO YESTERDAY.
THE UPPER LOW FINALLY MOVES FAR ENOUGH EAST BY SATURDAY THAT
RIDGING SHOULD BE ABLE TO MOVE INTO THE REGION. DID CLEAR SKIES ON
SATURDAY...HOPEFULLY IT ACTUALLY HAPPENS. MIN TEMPS FRIDAY NIGHT
WILL BE INFLUENCED BY CLOUDS...AND MODELS INDICATING THAT CLOUDS
WILL NOT ERODE UNTIL SATURDAY AFTER SUNRISE...SO RAISED VALUES A
FEW DEGREES.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 355 AM CDT FRI APR 12 2013
SATURDAY NIGHT-SUNDAY NIGHT...THE POSSIBLE SIGNIFICANT WINTER
STORM WILL BE THE MAIN CHALLENGE. 00Z MODELS ARE ALL IN AGREEMENT
THAT THE POTENTIAL EXISTS FOR HEAVY SNOWFALL AND STRONG
WINDS...AND ARE ALL FAIRLY SIMILAR WITH SYNOPTIC FEATURES. CURRENT
WATER VAPOR IMAGERY INDICATES A VERY STRONG WAVE NEAR THE GULF OF
ALASKA. THIS WAVE WILL DIVE SOUTHEAST AND INTO THE REGION BY
SUNDAY OR SUNDAY NIGHT...STALLING ONCE IT REACHES EASTERN NORTH
DAKOTA. MODELS INDICATE A BAND OF WARM AIR ADVECTION/FRONTOGENETICAL
FORCING ACROSS THE SOUTHERN FA BY SUNDAY MORNING...LIFTING
NORTHWARD THROUGH THE DAY ON SUNDAY...WITH WIDESPREAD 0.50 TO 1.00
INCH QPF (PWATS 0.5-0.6 INCHES). SREF P-TYPE PROBABILITY AND
ECMWF THERMAL PROFILES SUGGEST THIS TO BE ALL IN THE FORM OF SNOW.
THE GFS AND GEM DO BRING A WARM LAYER INTO THE FAR SOUTHEAST FA ON
SUNDAY...BUT THIS WOULD ONLY BE FOR A BRIEF PERIOD OF TIME. USING
AROUND A 13:1 RATIO DURING THE NIGHTTIME HOURS...AND 9:1 RATIO
DURING THE DAYTIME HOURS LEADS TO WIDESPREAD 7-14 INCHES OF SNOW
(AND CANNOT RULE OUT HIGHER AMOUNTS WHERE HEAVIER BANDS SET UP).
WINDS WILL ALSO BE AN ISSUE WITH THE GFS AND ECMWF INDICATING
925MB WINDS AROUND 35 KNOTS FROM THE EAST ON SUNDAY...AND THEN
FROM THE NORTH/NORTHEAST SUNDAY NIGHT (CREATING BLOWING SNOW AND
SIGNIFICANTLY REDUCED VISIBILITY). WITH MODELS IN SUCH GOOD
AGREEMENT...AND CONSISTENT FOR THE PAST SEVERAL DAYS...WILL ISSUE
A WINTER STORM WATCH. THE EXACT TRACK OF THE SYSTEM WILL DETERMINE
WHO GETS THE MOST SNOW...AND WHERE THE STRONGEST WINDS OCCUR.
MONDAY-THURSDAY...THE UPPER LOW WILL SLOWLY SHIFT NORTHEAST INTO
ONTARIO ON MONDAY. THE FLOW PATTERN WILL REMAIN BROADLY
CYCLONIC...WITH SOME SNOW SHOWERS/FLURRIES EXPECTED. WITH COLD AIR
ADVECTION AND 925 MB WINDS BETWEEN 30-40 KTS...CONTINUED GUSTY WINDS
ARE EXPECTED...GRADUALLY DIMINISHING DURING THE DAY.
A BREAK IN THE ACTION IS EXPECTED FOR TUESDAY...WITH HIGH PRESSURE
BUILDING INTO THE REGION. A FEW SNOW SHOWERS MAY LINGER...THOUGH.
CONTINUED WEAK COLD AIR ADVECTION WILL LIKELY KEEP MOST AREAS IN THE
30S...15 TO 20 DEGREES BELOW NORMAL.
ANOTHER INTENSE PACIFIC SHORTWAVE TROUGH IS EXPECTED TO DIG SOUTH
TOWARDS THE SOUTHERN ROCKIES BY MID-WEEK...WITH THE UPPER FLOW BECOMING
SOUTHWEST ACROSS THE PLAINS. THE 00Z MODELS LIFT THIS WAVE/SFC CYCLONE
NORTHEASTWARD ALONG THE REMNANT LOW-LEVEL BAROCLINIC ZONE. THE 00Z
GFS REMAINS FARTHER SOUTH COMPARED WITH THE ECMWF. THE ECMWF WOULD
BRING ANOTHER ROUND OF SNOW TO THE AREA...GIVEN IMPRESSIVE MID/UPPER
LEVEL DYNAMICS AND ITS NORTHWARD DISPLACEMENT OF THE UPPER
LOW...DESPITE KEEPING THE SFC LOW WELL TO THE SOUTHEAST. HOWEVER...GFS
ENSEMBLE MEMBERS INDICATE PLENTY OF SPREAD IN THE 500 MB LOW
TRACK...AND OVERALL CONFIDENCE IS LOW AT THIS RANGE. WILL MAINTAIN
CHANCE POPS DURING THE WED-THU PERIOD.
LOW-LEVEL THERMAL FIELDS DO NOT CHANGE MUCH THROUGH THE
PERIOD...WITH 925 MB TEMPS GENERALLY BETWEEN ABOUT -3 AND -8C. AS A
RESULT...HIGH TEMPS SHOULD REMAIN MAINLY IN THE 30S...WITH LOWS IN
THE 20S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 700 AM CDT FRI APR 12 2013
SCATTERED SNOW SHOWERS EXPECTED THROUGH THE DAYTIME HOURS...WITH
PERIODIC DROPS TO MVFR CONDITIONS. CLOUDS WILL REMAIN THROUGH THE
OVERNIGHT HOURS...BUT UNSURE HOW LOW THEY WILL BE. GUIDANCE IS
TOO LOW WITH CURRENT CIGS...AND MOST LIKELY SCENARIO FOR THE
OVERNIGHT HOURS WILL BE LOW VFR OR HIGH MVFR.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR NDZ028>030-038-039-049-052-053.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR NDZ006>008-014>016-024-026-027-054.
MN...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR MNZ002-003-022>024-027>032-040.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR MNZ001-004>009-013>017.
&&
$$
UPDATE...JR
SHORT TERM...TG
LONG TERM...TG/MAKOWSKI
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
700 AM CDT FRI APR 12 2013
.UPDATE...
ISSUED AT 700 AM CDT FRI APR 12 2013
BANDS OF SNOW SHOWERS CONTINUE TO ROTATE FROM EAST TO WEST THROUGH
THE REGION...WITH THE STEADIER SNOW ACROSS THE FAR EASTERN FA.
THIS IS IN LINE WITH THE EXPECTED FORECAST.
GETTING REPORTS OF FREEZING DRIZZLE FROM COOPERSTOWN TO VALLEY
CITY. RAP 10Z SOUNDING INDICATES A DRY LAYER FROM 700MB-
500MB...WITH THE SATURATED LAYER BELOW -8C TO -10C. THIS SOUNDING
IS NOT AN IDEAL SUPERCOOLED WATER DROPLET SCENARIO...BUT IT IS
OCCURRING. THE RAP DOES SATURATE THE 700MB-500MB LAYER AFTER
15Z...WHICH SHOULD ALLOW THE P-TYPE TO BE ALL SNOW AGAIN. WILL
INCLUDE FZDZ IN THE AREA UNTIL 15Z...AND ISSUE A SPS (A FEW CARS
REPORTED TO BE IN DITCH ALONG I-94).
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 355 AM CDT FRI APR 12 2013
THE UPPER LEVEL LOW WILL CONTINUE TO PROPAGATE NORTHEAST THROUGH
THE PERIOD. MODELS ARE IN GOOD AGREEMENT AND WILL USE A BLEND FOR
DETAILS. THE MAIN CHALLENGE FOR TODAY WILL BE SNOW CHANCES AND
AMOUNTS. UPPER LEVEL ENERGY CONTINUES TO ROTATE AROUND THE UPPER
LEVEL LOW...AND ANOTHER SHOT OF FORCING/MOISTURE IS HEADED TOWARD
THE EASTERN FA FOR THE MORNING HOURS. GIVEN UPSTREAM
OBSERVATIONS...RADAR IMAGERY...AND MODEL GUIDANCE...EXPECT AN
ADDITIONAL 2-4 INCHES OF SNOW ACROSS THE FAR EASTERN FA. SCATTERED
SNOW SHOWERS AND AN INCH OR TWO OF SNOW WILL OCCUR ALONG AND WEST
OF THE VALLEY. CLOUDS WILL HOLD STRONG TODAY...AND MAX TEMPS
SHOULD BE SIMILAR TO YESTERDAY.
THE UPPER LOW FINALLY MOVES FAR ENOUGH EAST BY SATURDAY THAT
RIDGING SHOULD BE ABLE TO MOVE INTO THE REGION. DID CLEAR SKIES ON
SATURDAY...HOPEFULLY IT ACTUALLY HAPPENS. MIN TEMPS FRIDAY NIGHT
WILL BE INFLUENCED BY CLOUDS...AND MODELS INDICATING THAT CLOUDS
WILL NOT ERODE UNTIL SATURDAY AFTER SUNRISE...SO RAISED VALUES A
FEW DEGREES.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 355 AM CDT FRI APR 12 2013
SATURDAY NIGHT-SUNDAY NIGHT...THE POSSIBLE SIGNIFICANT WINTER
STORM WILL BE THE MAIN CHALLENGE. 00Z MODELS ARE ALL IN AGREEMENT
THAT THE POTENTIAL EXISTS FOR HEAVY SNOWFALL AND STRONG
WINDS...AND ARE ALL FAIRLY SIMILAR WITH SYNOPTIC FEATURES. CURRENT
WATER VAPOR IMAGERY INDICATES A VERY STRONG WAVE NEAR THE GULF OF
ALASKA. THIS WAVE WILL DIVE SOUTHEAST AND INTO THE REGION BY
SUNDAY OR SUNDAY NIGHT...STALLING ONCE IT REACHES EASTERN NORTH
DAKOTA. MODELS INDICATE A BAND OF WARM AIR ADVECTION/FRONTOGENETICAL
FORCING ACROSS THE SOUTHERN FA BY SUNDAY MORNING...LIFTING
NORTHWARD THROUGH THE DAY ON SUNDAY...WITH WIDESPREAD 0.50 TO 1.00
INCH QPF (PWATS 0.5-0.6 INCHES). SREF P-TYPE PROBABILITY AND
ECMWF THERMAL PROFILES SUGGEST THIS TO BE ALL IN THE FORM OF SNOW.
THE GFS AND GEM DO BRING A WARM LAYER INTO THE FAR SOUTHEAST FA ON
SUNDAY...BUT THIS WOULD ONLY BE FOR A BRIEF PERIOD OF TIME. USING
AROUND A 13:1 RATIO DURING THE NIGHTTIME HOURS...AND 9:1 RATIO
DURING THE DAYTIME HOURS LEADS TO WIDESPREAD 7-14 INCHES OF SNOW
(AND CANNOT RULE OUT HIGHER AMOUNTS WHERE HEAVIER BANDS SET UP).
WINDS WILL ALSO BE AN ISSUE WITH THE GFS AND ECMWF INDICATING
925MB WINDS AROUND 35 KNOTS FROM THE EAST ON SUNDAY...AND THEN
FROM THE NORTH/NORTHEAST SUNDAY NIGHT (CREATING BLOWING SNOW AND
SIGNIFICANTLY REDUCED VISIBILITY). WITH MODELS IN SUCH GOOD
AGREEMENT...AND CONSISTENT FOR THE PAST SEVERAL DAYS...WILL ISSUE
A WINTER STORM WATCH. THE EXACT TRACK OF THE SYSTEM WILL DETERMINE
WHO GETS THE MOST SNOW...AND WHERE THE STRONGEST WINDS OCCUR.
MONDAY-THURSDAY...THE UPPER LOW WILL SLOWLY SHIFT NORTHEAST INTO
ONTARIO ON MONDAY. THE FLOW PATTERN WILL REMAIN BROADLY
CYCLONIC...WITH SOME SNOW SHOWERS/FLURRIES EXPECTED. WITH COLD AIR
ADVECTION AND 925 MB WINDS BETWEEN 30-40 KTS...CONTINUED GUSTY WINDS
ARE EXPECTED...GRADUALLY DIMINISHING DURING THE DAY.
A BREAK IN THE ACTION IS EXPECTED FOR TUESDAY...WITH HIGH PRESSURE
BUILDING INTO THE REGION. A FEW SNOW SHOWERS MAY LINGER...THOUGH.
CONTINUED WEAK COLD AIR ADVECTION WILL LIKELY KEEP MOST AREAS IN THE
30S...15 TO 20 DEGREES BELOW NORMAL.
ANOTHER INTENSE PACIFIC SHORTWAVE TROUGH IS EXPECTED TO DIG SOUTH
TOWARDS THE SOUTHERN ROCKIES BY MID-WEEK...WITH THE UPPER FLOW BECOMING
SOUTHWEST ACROSS THE PLAINS. THE 00Z MODELS LIFT THIS WAVE/SFC CYCLONE
NORTHEASTWARD ALONG THE REMNANT LOW-LEVEL BAROCLINIC ZONE. THE 00Z
GFS REMAINS FARTHER SOUTH COMPARED WITH THE ECMWF. THE ECMWF WOULD
BRING ANOTHER ROUND OF SNOW TO THE AREA...GIVEN IMPRESSIVE MID/UPPER
LEVEL DYNAMICS AND ITS NORTHWARD DISPLACEMENT OF THE UPPER
LOW...DESPITE KEEPING THE SFC LOW WELL TO THE SOUTHEAST. HOWEVER...GFS
ENSEMBLE MEMBERS INDICATE PLENTY OF SPREAD IN THE 500 MB LOW
TRACK...AND OVERALL CONFIDENCE IS LOW AT THIS RANGE. WILL MAINTAIN
CHANCE POPS DURING THE WED-THU PERIOD.
LOW-LEVEL THERMAL FIELDS DO NOT CHANGE MUCH THROUGH THE
PERIOD...WITH 925 MB TEMPS GENERALLY BETWEEN ABOUT -3 AND -8C. AS A
RESULT...HIGH TEMPS SHOULD REMAIN MAINLY IN THE 30S...WITH LOWS IN
THE 20S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 700 AM CDT FRI APR 12 2013
SCATTERED SNOW SHOWERS EXPECTED THROUGH THE DAYTIME HOURS...WITH
PERIODIC DROPS TO MVFR CONDITIONS. CLOUDS WILL REMAIN THROUGH THE
OVERNIGHT HOURS...BUT UNSURE HOW LOW THEY WILL BE. GUIDANCE IS
TOO LOW WITH CURRENT CIGS...AND MOST LIKELY SCENARIO FOR THE
OVERNIGHT HOURS WILL BE LOW VFR OR HIGH MVFR.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR NDZ028>030-038-039-049-052-053.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR NDZ006>008-014>016-024-026-027-054.
MN...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR MNZ002-003-022>024-027>032-040.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR MNZ001-004>009-013>017.
&&
$$
UPDATE...TG
SHORT TERM...TG
LONG TERM...TG/MAKOWSKI
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
600 AM CDT FRI APR 12 2013
.UPDATE...
ISSUED AT 600 AM CDT FRI APR 12 2013
GETTING REPORTS OF FREEZING DRIZZLE FROM COOPERSTOWN TO VALLEY
CITY. RAP 10Z SOUNDING INDICATES A DRY LAYER FROM 700MB-
500MB...WITH THE SATURATED LAYER BELOW -8C TO -10C. THIS SOUNDING
IS NOT AN IDEAL SUPERCOOLED WATER DROPLET SCENARIO...BUT IT IS
OCCURRING. THE RAP DOES SATURATE THE 700MB-500MB LAYER AFTER
15Z...WHICH SHOULD ALLOW THE P-TYPE TO BE ALL SNOW AGAIN. WILL
INCLUDE FZDZ IN THE AREA UNTIL 15Z...AND ISSUE A SPS (A FEW CARS
REPORTED TO BE IN DITCH ALONG I-94).
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 355 AM CDT FRI APR 12 2013
THE UPPER LEVEL LOW WILL CONTINUE TO PROPAGATE NORTHEAST THROUGH
THE PERIOD. MODELS ARE IN GOOD AGREEMENT AND WILL USE A BLEND FOR
DETAILS. THE MAIN CHALLENGE FOR TODAY WILL BE SNOW CHANCES AND
AMOUNTS. UPPER LEVEL ENERGY CONTINUES TO ROTATE AROUND THE UPPER
LEVEL LOW...AND ANOTHER SHOT OF FORCING/MOISTURE IS HEADED TOWARD
THE EASTERN FA FOR THE MORNING HOURS. GIVEN UPSTREAM
OBSERVATIONS...RADAR IMAGERY...AND MODEL GUIDANCE...EXPECT AN
ADDITIONAL 2-4 INCHES OF SNOW ACROSS THE FAR EASTERN FA. SCATTERED
SNOW SHOWERS AND AN INCH OR TWO OF SNOW WILL OCCUR ALONG AND WEST
OF THE VALLEY. CLOUDS WILL HOLD STRONG TODAY...AND MAX TEMPS
SHOULD BE SIMILAR TO YESTERDAY.
THE UPPER LOW FINALLY MOVES FAR ENOUGH EAST BY SATURDAY THAT
RIDGING SHOULD BE ABLE TO MOVE INTO THE REGION. DID CLEAR SKIES ON
SATURDAY...HOPEFULLY IT ACTUALLY HAPPENS. MIN TEMPS FRIDAY NIGHT
WILL BE INFLUENCED BY CLOUDS...AND MODELS INDICATING THAT CLOUDS
WILL NOT ERODE UNTIL SATURDAY AFTER SUNRISE...SO RAISED VALUES A
FEW DEGREES.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 355 AM CDT FRI APR 12 2013
SATURDAY NIGHT-SUNDAY NIGHT...THE POSSIBLE SIGNIFICANT WINTER
STORM WILL BE THE MAIN CHALLENGE. 00Z MODELS ARE ALL IN AGREEMENT
THAT THE POTENTIAL EXISTS FOR HEAVY SNOWFALL AND STRONG
WINDS...AND ARE ALL FAIRLY SIMILAR WITH SYNOPTIC FEATURES. CURRENT
WATER VAPOR IMAGERY INDICATES A VERY STRONG WAVE NEAR THE GULF OF
ALASKA. THIS WAVE WILL DIVE SOUTHEAST AND INTO THE REGION BY
SUNDAY OR SUNDAY NIGHT...STALLING ONCE IT REACHES EASTERN NORTH
DAKOTA. MODELS INDICATE A BAND OF WARM AIR ADVECTION/FRONTOGENETICAL
FORCING ACROSS THE SOUTHERN FA BY SUNDAY MORNING...LIFTING
NORTHWARD THROUGH THE DAY ON SUNDAY...WITH WIDESPREAD 0.50 TO 1.00
INCH QPF (PWATS 0.5-0.6 INCHES). SREF P-TYPE PROBABILITY AND
ECMWF THERMAL PROFILES SUGGEST THIS TO BE ALL IN THE FORM OF SNOW.
THE GFS AND GEM DO BRING A WARM LAYER INTO THE FAR SOUTHEAST FA ON
SUNDAY...BUT THIS WOULD ONLY BE FOR A BRIEF PERIOD OF TIME. USING
AROUND A 13:1 RATIO DURING THE NIGHTTIME HOURS...AND 9:1 RATIO
DURING THE DAYTIME HOURS LEADS TO WIDESPREAD 7-14 INCHES OF SNOW
(AND CANNOT RULE OUT HIGHER AMOUNTS WHERE HEAVIER BANDS SET UP).
WINDS WILL ALSO BE AN ISSUE WITH THE GFS AND ECMWF INDICATING
925MB WINDS AROUND 35 KNOTS FROM THE EAST ON SUNDAY...AND THEN
FROM THE NORTH/NORTHEAST SUNDAY NIGHT (CREATING BLOWING SNOW AND
SIGNIFICANTLY REDUCED VISIBILITY). WITH MODELS IN SUCH GOOD
AGREEMENT...AND CONSISTENT FOR THE PAST SEVERAL DAYS...WILL ISSUE
A WINTER STORM WATCH. THE EXACT TRACK OF THE SYSTEM WILL DETERMINE
WHO GETS THE MOST SNOW...AND WHERE THE STRONGEST WINDS OCCUR.
MONDAY-THURSDAY...THE UPPER LOW WILL SLOWLY SHIFT NORTHEAST INTO
ONTARIO ON MONDAY. THE FLOW PATTERN WILL REMAIN BROADLY
CYCLONIC...WITH SOME SNOW SHOWERS/FLURRIES EXPECTED. WITH COLD AIR
ADVECTION AND 925 MB WINDS BETWEEN 30-40 KTS...CONTINUED GUSTY WINDS
ARE EXPECTED...GRADUALLY DIMINISHING DURING THE DAY.
A BREAK IN THE ACTION IS EXPECTED FOR TUESDAY...WITH HIGH PRESSURE
BUILDING INTO THE REGION. A FEW SNOW SHOWERS MAY LINGER...THOUGH.
CONTINUED WEAK COLD AIR ADVECTION WILL LIKELY KEEP MOST AREAS IN THE
30S...15 TO 20 DEGREES BELOW NORMAL.
ANOTHER INTENSE PACIFIC SHORTWAVE TROUGH IS EXPECTED TO DIG SOUTH
TOWARDS THE SOUTHERN ROCKIES BY MID-WEEK...WITH THE UPPER FLOW BECOMING
SOUTHWEST ACROSS THE PLAINS. THE 00Z MODELS LIFT THIS WAVE/SFC CYCLONE
NORTHEASTWARD ALONG THE REMNANT LOW-LEVEL BAROCLINIC ZONE. THE 00Z
GFS REMAINS FARTHER SOUTH COMPARED WITH THE ECMWF. THE ECMWF WOULD
BRING ANOTHER ROUND OF SNOW TO THE AREA...GIVEN IMPRESSIVE MID/UPPER
LEVEL DYNAMICS AND ITS NORTHWARD DISPLACEMENT OF THE UPPER
LOW...DESPITE KEEPING THE SFC LOW WELL TO THE SOUTHEAST. HOWEVER...GFS
ENSEMBLE MEMBERS INDICATE PLENTY OF SPREAD IN THE 500 MB LOW
TRACK...AND OVERALL CONFIDENCE IS LOW AT THIS RANGE. WILL MAINTAIN
CHANCE POPS DURING THE WED-THU PERIOD.
LOW-LEVEL THERMAL FIELDS DO NOT CHANGE MUCH THROUGH THE
PERIOD...WITH 925 MB TEMPS GENERALLY BETWEEN ABOUT -3 AND -8C. AS A
RESULT...HIGH TEMPS SHOULD REMAIN MAINLY IN THE 30S...WITH LOWS IN
THE 20S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1151 PM CDT THU APR 11 2013
VFR CONDITIONS WERE GENERALLY OVER NORTHERN MN. MVFR AND SOME IFR
CONDITIONS WERE OVER WESTERN ZONES. EXPECT BANDS OF IFR/MVFR
CONDITIONS TO MOVE THROUGH THE AREA DUE TO SNOW NEXT 24 HOURS AS
UPPER LEVEL SYSTEMS ROTATE AROUND UPPER LEVEL LOW PRESSURE SYSTEM.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR NDZ028>030-038-039-049-052-053.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR NDZ006>008-014>016-024-026-027-054.
MN...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR MNZ002-003-022>024-027>032-040.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR MNZ001-004>009-013>017.
&&
$$
UPDATE...TG
SHORT TERM...TG
LONG TERM...TG/MAKOWSKI
AVIATION...HOPPES
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
944 AM EDT FRI APR 12 2013
.SYNOPSIS...
LOW PRESSURE OVER NORTHERN OHIO EARLY THIS MORNING WILL LIFT
NORTHEAST AND TAKE A COLD FRONT EAST ACROSS THE AREA. THIS WILL
END THE MAJORITY OF THE PRECIPITATION BY EARLY AFTERNOON. HIGH
PRESSURE WILL BUILD ACROSS THE LOWER OHIO VALLEY AND TN VALLEY
LATER TODAY AND THEN ACROSS THE UPPER OHIO VALLEY FOR SUNDAY.
ANOTHER FRONTAL SYSTEM WILL BE IN THE VICINITY FOR THE FIRST PART
OF THE NEW WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RAIN IS EXITING THE REGION THIS MORNING. WILL CONTINUE POPS IN NW PA FOR
A FEW HOURS WITH A SHARP DECREASING TREND. MILD TEMPERATURES ARE
CONFINED TO THE EASTERN COUNTIES OF OHIO AND NW PA CURRENTLY BUT
THESE WILL COOL SEVERAL DEGREES WITH THE PASSAGE OF THE SURFACE
LOW CURRENTLY OVER NW PA. ELSEWHERE TEMPERATURES WILL RISE VERY
SLOWLY TODAY UNDER CLOUDY SKIES.
MODELS SHOW A WEAK IMPULSE MOVING THROUGH THE OHIO VALLEY THIS
AFTERNOON. THE HRRR CREATES A FAIR AMOUNT OF WEAK CONVECTIVE TYPE
PCPN OVER THE REGION LATE IN THE AFTERNOON WITH THE ARRIVAL OF THE
TOUGH AXIS. WILL INCLUDE A SLIGHT CHANCE OF SHOWERS IN THE
AFTERNOON TO REFLECT THE POSSIBILITY OF LIGHT SHOWERS OR VIRGA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
COOL HIGH PRESSURE MOVES TO THE LOWER OHIO VALLEY TONIGHT WITH
SOME DEGREE OF RIDGING NUDGING UP INTO OHIO. HAVE KEPT THE LOW
PRECIP CHANCES FOR THE EAST HALF...BUT AGAIN FOLLOWING FROM THIS
AFTERNOON...NOT ENTIRELY CONFIDENT WE JUST WILL NOT DRY OUT
ALTOGETHER. HAVE REMOVED THE SNOW MENTION FROM TONIGHTS
FORECAST...AS MOISTURE IS LIMITED. TONIGHT WILL BE MUCH COOLER
WITH LOWS IN THE 30S EVERYWHERE.
UPPER LOW WILL STILL BE OVER THE GREAT LAKES SATURDAY AND IT WILL
ATTEMPT TO BRING A BIT OF JET ENERGY/SHORTWAVE TROUGH ACROSS THE
LOWER LAKES. THEREFORE AGAIN KEEP THE LOW PRECIP CHANCES ACROSS
THE EAST FOR ANY SHOWER ACTIVITY. IF THERE IS INDEED BETTER
MOISTURE THIS GO AROUND...THEN NW PA MAY SEE A FEW FLAKES OF SNOW
SATURDAY NIGHT. OUR COLDEST DAY WILL BE SATURDAY WITH HIGHS FROM
THE MID 40S TO NEAR 50 AND NEAR FREEZING SAT NIGHT.
THE RECOVERY BEGINS SUNDAY AS HIGH PRESSURE MOVES TO THE UPPER
OHIO VALLEY AND WE BEGIN TO GET A WARM ADVECT PUSH OUR WAY. WILL
HAVE BUILDING RIDGING ALOFT BETWEEN SUNDAY AND MONDAY AS A TROUGH
MOVES OUT OF THE INTER-MOUNTAIN WEST AND INTO THE PLAINS. TEMPS
WILL WARM TO NEAR NORMAL. MILDER THAN PREVIOUS NIGHTS MONDAY
NIGHT.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
RIDGING ALOFT IS PROGGED OVER THE EASTERN HALF OF THE COUNTRY THE
FIRST HALF OF NEXT WEEK. A SERIES OF SHORT WAVES FROM THE WEST WILL
EJECT OUT ACROSS THE PLAINS STATES. A COLD FRONT WILL MAKE PROGRESS
ACROSS THE UPPER MIDWEST AND WESTERN GREAT LAKES. THE CHALLENGE
WILL BE TO SEE HOW FAR EAST THE FRONT CAN GET BEFORE IT STALLS. THE
MODELS ARE IN SOME AGREEMENT... MORE THAN WE SAW THIS PAST WEEK.
FOR NOW WE WILL GO WITH THE IDEA OF THE FRONT MAKING IT TO THE
FORECAST AREA ON TUESDAY...BECOMING NEARLY STATIONARY FOR
WEDNESDAY...AND LIKELY SHIFTING BACK NORTH ON THURSDAY AHEAD OF THE
NEXT SURFACE LOW COMING OUT OF THE MISSISSIPPI VALLEY. I HAVE NUDGED
TEMPERATURES COOLER/WARMER RELATIVE OF THE FRONT BUT BASICALLY SPLIT
THE DIFFERENCE ON HOW COOL/WARM IT COULD BE SINCE THERE IS SO MUCH
UNCERTAINTY THIS FAR IN ADVANCE.
WILL KEEP A CHANCE OF SHOWERS PRETTY MUCH EACH DAY WITH "LIKELY" BY
THURSDAY. COULD MENTION THUNDER EACH DAY BUT DECIDED TO FOCUS MAINLY
ON THURSDAY WHEN THINGS MAY BE THE MOST UNSTABLE. AGAIN...PRETTY FAR
IN THE FUTURE TO TRY AND GET SPECIFIC.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
THE SURFACE LOW PRESSURE AND COLD FRONT WILL BE EAST OF THE
FORECAST AREA MID MORNING. WINDS ARE COMING AROUND FROM THE WEST
SOUTHWEST AND WILL BECOME GUSTY AS THE DAY GOES ON. IFR CEILINGS
WILL GRADUALLY BECOME MVFR AND THEN VFR FROM WEST TO EAST AS
DRIER AIR FILTERS IN BEHIND THE SYSTEM. VISIBILITIES WILL IMPROVE
TO VFR WHEN THE RAIN ENDS. WINDS WILL BE LESS GUSTY TONIGHT. VFR
CEILINGS (035) WILL CONTINUE TONIGHT.
.OUTLOOK...NON-VFR SATURDAY...ESPECIALLY NE OH/NW PA IN THE MORNING.
NON VFR DEVELOPING TUESDAY.
&&
.MARINE...
THE SURFACE LOW WILL SLIDE ACROSS EASTERN LAKE ERIE EARLY THIS
MORNING AND WINDS ON THE LAKE WILL FINALLY SHIFT FROM THE EAST TO
THE SOUTHWEST. THERE WILL BE A SHORT LULL IN THE WIND AND WAVES THIS
MORNING AS THE WIND SHIFT OCCURS BUT WILL KEEP THE SMALL CRAFT
ADVISORY IN EFFECT AS THE SOUTHWEST WINDS WILL INCREASE TO 15 TO 25
KNOTS BY THIS AFTERNOON.
THE SOUTHWEST TO WEST WIND WILL REMAIN BRISK INTO SATURDAY...THEN
FINALLY DIMINISH AS HIGH PRESSURE BUILDS ACROSS THE LAKE ON
SATURDAY NIGHT. WINDS WILL COME AROUND FROM THE SOUTH TO SOUTHWEST
ON SUNDAY. THE NEXT COLD FRONT IS DUE BY TUESDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT SATURDAY FOR LEZ142>149.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...LAPLANTE
SHORT TERM...OUDEMAN
LONG TERM...KOSARIK
AVIATION...KOSARIK
MARINE...KOSARIK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
129 PM EDT FRI APR 12 2013
.SYNOPSIS...
DRY HIGH PRESSURE WILL BUILD IN FROM THE WEST AND PERSIST THROUGH
THE WEEKEND. AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE AREA
SUNDAY NIGHT WITH MOISTURE AND RAIN. A MOIST SOUTHERLY FLOW THEN
DEVELOPS ACROSS THE REGION THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AT 125 PM...TEMPS OVER THE PIEDMONT INCREASING FASTER THAN CURRENT
GRIDS INDICATE SO ADJUSTED HIGHER PER LATEST LAMP WHICH HAS CAUGHT
THE TREND. THUS...MAX TEMPS A COUPLE DEGREES HIGHER TODAY.
PREVIOUS DISCUSSION:
AT 1145 AM...DID A QUICK UPDATE FOR TEMP AND POP TRENDS. PREFRONTAL
LINE OF SHRA NOW WELL EAST OF THE AREA. ACTUAL FRONT GETTING LOST IN
LEE TROUGH DEVELOPMENT...BUT DEWPOINTS INDICATE THE FRONT IS MAKING
ITS WAY THROUGH THE NC PIDMONT AND SOUTHERN UPSTATE. LATEST HRRR
BACKING OFF ON THE IDEA OF ISOLATED SHOWERS OVER THE NC PIEDMONT
THIS AFTENROON. WITH DEWPOINTS LOWERING SHOWER DEVELOPMENT SEEMS
UNLIKLEY...SO WILL REMOVE THE MENTIONABLE POPS.
AT 10AM EDT...LATEST SURFACE ANALYSIS INDICATES THAT THE ACTUAL
FRONT IS LOCATED FROM JUST EAST OF BOONE...SOUTH TO ABOUT
RUTHERFORDTON TO GSP. ONLY A WIND SHIFT AT THIS TIME WITH THE FRONT.
RADARS CONTINUE TO SHOW THE PREFRONTAL LINE OF NOW JUST SHRA FROM
UNION COUNTY NC...SW THROUGH SE CHESTER COUNTY SC AND THEN SOUTH OF
GREENWOOD. THIS LINE IS DRIFTING SE AND SHOULD CLEAR THE FORECAST
AREA BY MIDDAY. THEREFORE...I HAVE ADJUSTED THE POP FIELD TO FIT THE
LATEST RADAR AND TRENDS. THE HRRR IS INDICATING THAT SOME ISOLATED
SHRA COOULD DEVELOP WITH THE FRONT OVER THE EASTERN PORTION OF THE
FORECAST AREA WITH THE FRONTAL PASSAGE THIS AFTERNOON...SO HAVE
BROUGHT SOME ISOLATED POPS BACK INTO THAT AREA. OTHERWISE...EXPECT
CLEARING TO OCCUR WITH THE INCREASINGLY DOWNSLOPE WINDS. IT WILL
ALSO BE A BREEZY AFTERNOON WITH TEMPS WARMING TO A LITTLE ABOVE
AVERAGE EAST OF THE MOUNTAINS AND NEAR NORMAL MOUNTAINS. CURRENT MAX
TEMP FORECAST LOOKS ON TRACK.
1100 UTC UPDATE...WINDS WERE UPDATED TO INCLUDE THE 06Z NAM. POPS
HAVE BEEN ADJUSTED TO FIR THE TIMING OF PRECIPITATION MOVING OFF THE
BLUE RIDGE JUST AHEAD OF THE COLD FRONT.
AT 345 AM EST FRIDAY...A CLOSED UPPER LOW WILL MOVE FROM THE PLAINS
TO THE GREAT LAKES TODAY AND TONIGHT. AN ASSOCIATED COLD FRONT WILL
CROSS OUR AREA THIS MORNING...PRECEDED BY A WEAKENING LINE OF
CONVECTION. THE CURRENT TORNADO WATCH ALONG THE INTERSTATE 77
CORRIDOR WILL EXPIRE AT 400 AM...AND BASED ON RADAR TRENDS THE LINE
WILL MOVE OUT OF OUR AREA AROUND THAT TIME. CONVECTION ALONG THE
FRONT ITSELF STILL HAS LESS CHANCE OF BEING SEVERE...WITH LESS SHEAR
AND INSTABILITY. FRONTAL PASSAGE SHOULD BE AROUND DAYBREAK.
OBSERVATIONS SHOW LOW CLOUDS LINGERING FOR SOME DISTANCE BEHIND THE
FRONT...BUT CLOUDS SHOULD BREAK UP FROM THE SW BY MID MORNING.
GUSTY S WINDS WILL VEER TO WSW EAST OF THE MOUNTAINS AND NW IN THE
MOUNTAINS...REMAINING GUSTY. HIGH TEMPERATURES WILL RUNS SLIGHTLY
ABOVE NORMAL IN THE LEE OF THE MOUNTAINS WITH A WARMING DOWNSLOPE
FLOW...AND WILL BE AROUND NORMAL IN THE MOUNTAINS IN COLD ADVECTION.
WINDS WILL DECREASE TONIGHT AS THE PRESSURE GRADIENT WEAKENS...
VEERING NW IN NC...AND W IN SC. MINIMUM TEMPERATURES WILL RUN A A
FEW DEGREES BELOW NORMAL.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...SAT AND SAT NITE WILL BE QUIET WITH SLOWLY
RISING HEIGHTS AS AN UPPER LOW MOVES EASTWARD JUST NORTH OF THE
GREAT LAKES AND UPPER RIDGING MOVES IN FROM THE WEST. AT THE SFC...
WEAK HIGH PRESSURE MOVES ACROSS THE AREA AS WELL. SHUD BE DRY WX
WITH HIGHS A FEW DEGREES ABOVE NORMAL. LOWS WILL BE A LITTLE BELOW
NORMAL OVER THE MTNS AND A LITTLE ABOVE ELSEWHERE. SHORT WAVES KNOCK
DOWN THE RIDGE SUN AND MOVE ACROSS THE AREA SUN NITE. THE GFS IS A
LITTLE FASTER THAN THE OTHER GUIDANCE...BUT PRECIP MOVES TO OUR SWRN
DOORSTEP BY THE END OF THE DAY SUNDAY...THEN ACROSS THE AREA SUN
NITE. LOW LEVEL MOISTURE AND ISENTROPIC LIFT...ALONG WITH UPPER
DIVERGENCE....ARE MAXIMIZED SUN NITE WITH BEST PRECIP CHC OVER THE
SRN CWFA. WITH PRECIP HOLDING OFF...HIGHS SUN WILL BE UP TO 5
DEGREES ABOVE NORMAL. CLOUDS WILL KEEP LOWS 5 TO AS MUCH AS 10
DEGREES ABOVE NORMAL.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 100 PM FRI...A UPPER LEVEL RIDGE WILL BE IN PLACE OVER THE
EAST COAST TO START THE MEDIUM RANGE 00Z TUESDAY. SURFACE HIGH
PRESSURE WILL BE OFF THE MID ATLANTIC AND NE COAST WITH A MOIST
SOUTHERLY FLOW ACROSS FLORIDA TO GA AND THE WESTERN CAROLINAS
THROUGH TUESDAY. AN UPSLOPE COMPONENT WILL HELP TO ENHANCE SMALL
POPS MAINLY OVER THE MTNS. THE RIDGE BREAKS DOWN THROUGH MID WEEK AS
WEAK LOBES OF ENERGY CROSS TN WHILE THE LARGER TROF DIGS FROM THE
ROCKIES SPREADING EAST ACROSS THE PLAINS INTO THURSDAY. LOW PRESSURE
WILL DEVELOP OVER THE INFLECTION POINT OF THE DIGGING TROF NEAR EAST
TEXAS AROUND 00Z THURSDAY AND MOVES NE. THE COLD FRONT WILL APPROACH
OUR REGION FROM THE WEST THURSDAY AND EARLY FRIDAY. CAPES ARE SHOWN
TO BE 1000 TO 1300 ALONG AND SE OF I-85 LATE THURSDAY ON THE GFS.
THE GFS IS CERTAINLY THE MORE PROGRESSIVE MODEL AS IT TAKES THE
FRONT OFF THE CAROLINA COAST BY FRIDAY EVENING. THE OLD ECMWF GETS
THE FRONT OFF THE COAST MID DAY SATURDAY. BIG DIFFERENCE IN TIMING
AND ALTHOUGH FAVORING GFS DID NOT COMPLETELY JUMP ONBOARD WITH THE
FINAL SOLUTION. TEMPERATURES WILL BE A FEW DEGREES ABOVE NORMAL
THROUGH MID WEEK THEN DROP TO NEAR OR BELOW NORMAL WITH THE PASSAGE
OF THE FRONT LATE IN THE WEEK.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...VFR CIG BKN070 SHOULD SCT AROUND 18Z AS DRYER AIR
CONTINUES TO OVERSPREAD THE AREA. EXPECT SKC BY LATE AFTERNOON. WEAK
FRONT WILL MOVE EAST OF THE AREA. GUSTY SW WINDS WILL SHIFT NW AFTER
23Z AND DIMINISH.
ELSEWHERE...SCT VFR CLOUDS WILL DISSIPATE WITH SKC EXPECTED AT ALL
AIRFIELDS BY LATE AFTERNOON. GUSTY SW WINDS WILL TURN NW THIS
EVENING AS A WEAK FRONT CONTINUES TO MOVE AWAY FROM THE AREA AND
LEE TROUGH DISSIPATES. THE EXCEPTION FOR WINDS IS KAVL WHERE
WINDS WILL REMAIN NNW.
OUTLOOK...DRY HIGH PRESSURE WILL BUILD INTO THE REGION THROUGH THE
WEEKEND WITH VFR CONDITIONS CONTINUING. AN UPPER DISTURBANCE WILL
APPROACH FROM THE SW SUNDAY NIGHT WHICH IS EXPECTED TO PRODUCE
SHOWERS WITH SOME RESTRICTIONS BEGINNING SUN NIGHT AND CONTINUING
THROUGH MON.
CONFIDENCE TABLE...
17-23Z 23-05Z 05-11Z 11-17Z
KCLT HIGH 99% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...LG
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...LG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1002 AM EDT FRI APR 12 2013
.SYNOPSIS...
A STRONG COLD FRONT MOVES EAST OF THE WESTERN CAROLINAS AND
NORTHEAST GEORGIA TODAY. DRY HIGH PRESSURE WILL THEN BUILD IN FROM
THE WEST AND PERSIST THROUGH THE WEEKEND. AN UPPER LEVEL DISTURBANCE
WILL MOVE ACROSS THE AREA SUNDAY NIGHT WITH MOISTURE AND RAIN. A
MOIST SOUTHERLY FLOW THEN DEVELOPS ACROSS THE REGION THROUGH THE
MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 10AM EDT...LATEST SURFACE ANALYSIS INDICATES THAT THE ACTUAL
FRONT IS LOCATED FROM JUST EAST OF BOONE...SOUTH TO ABOUT
RUTHERFORDTON TO GSP. ONLY A WIND SHIFT AT THIS TIME WITH THE FRONT.
RADARS CONTINUE TO SHOW THE PREFRONTAL LINE OF NOW JUST SHRA FROM
UNION COUNTY NC...SW THROUGH SE CHESTER COUNTY SC AND THEN SOUTH OF
GREENWOOD. THIS LINE IS DRIFTING SE AND SHOULD CLEAR THE FORECAST
AREA BY MIDDAY. THEREFORE...I HAVE ADJUSTED THE POP FIELD TO FIT THE
LATEST RADAR AND TRENDS. THE HRRR IS INDICATING THAT SOME ISOLATED
SHRA COOULD DEVELOP WITH THE FRONT OVER THE EASTERN PORTION OF THE
FORECAST AREA WITH THE FRONTAL PASSAGE THIS AFTERNOON...SO HAVE
BROUGHT SOME ISOLATED POPS BACK INTO THAT AREA. OTHERWISE...EXPECT
CLEARING TO OCCUR WITH THE INCREASINGLY DOWNSLOPE WINDS. IT WILL
ALSO BE A BREEZY AFTERNOON WITH TEMPS WARMING TO A LITTLE ABOVE
AVERAGE EAST OF THE MOUNTAINS AND NEAR NORMAL MOUNTAINS. CURRENT MAX
TEMP FORECAST LOOKS ON TRACK.
PREVIOUS DISCUSSION:
1100 UTC UPDATE...WINDS WERE UPDATED TO INCLUDE THE 06Z NAM. POPS
HAVE BEEN ADJUSTED TO FIR THE TIMING OF PRECIPITATION MOVING OFF THE
BLUE RIDGE JUST AHEAD OF THE COLD FRONT.
AT 345 AM EST FRIDAY...A CLOSED UPPER LOW WILL MOVE FROM THE PLAINS
TO THE GREAT LAKES TODAY AND TONIGHT. AN ASSOCIATED COLD FRONT WILL
CROSS OUR AREA THIS MORNING...PRECEDED BY A WEAKENING LINE OF
CONVECTION. THE CURRENT TORNADO WATCH ALONG THE INTERSTATE 77
CORRIDOR WILL EXPIRE AT 400 AM...AND BASED ON RADAR TRENDS THE LINE
WILL MOVE OUT OF OUR AREA AROUND THAT TIME. CONVECTION ALONG THE
FRONT ITSELF STILL HAS LESS CHANCE OF BEING SEVERE...WITH LESS SHEAR
AND INSTABILITY. FRONTAL PASSAGE SHOULD BE AROUND DAYBREAK.
OBSERVATIONS SHOW LOW CLOUDS LINGERING FOR SOME DISTANCE BEHIND THE
FRONT...BUT CLOUDS SHOULD BREAK UP FROM THE SW BY MID MORNING.
GUSTY S WINDS WILL VEER TO WSW EAST OF THE MOUNTAINS AND NW IN THE
MOUNTAINS...REMAINING GUSTY. HIGH TEMPERATURES WILL RUNS SLIGHTLY
ABOVE NORMAL IN THE LEE OF THE MOUNTAINS WITH A WARMING DOWNSLOPE
FLOW...AND WILL BE AROUND NORMAL IN THE MOUNTAINS IN COLD ADVECTION.
WINDS WILL DECREASE TONIGHT AS THE PRESSURE GRADIENT WEAKENS...
VEERING NW IN NC...AND W IN SC. MINIMUM TEMPERATURES WILL RUN A A
FEW DEGREES BELOW NORMAL.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...SAT AND SAT NITE WILL BE QUIET WITH SLOWLY
RISING HEIGHTS AS AN UPPER LOW MOVES EASTWARD JUST NORTH OF THE
GREAT LAKES AND UPPER RIDGING MOVES IN FROM THE WEST. AT THE SFC...
WEAK HIGH PRESSURE MOVES ACROSS THE AREA AS WELL. SHUD BE DRY WX
WITH HIGHS A FEW DEGREES ABOVE NORMAL. LOWS WILL BE A LITTLE BELOW
NORMAL OVER THE MTNS AND A LITTLE ABOVE ELSEWHERE. SHORT WAVES KNOCK
DOWN THE RIDGE SUN AND MOVE ACROSS THE AREA SUN NITE. THE GFS IS A
LITTLE FASTER THAN THE OTHER GUIDANCE...BUT PRECIP MOVES TO OUR SWRN
DOORSTEP BY THE END OF THE DAY SUNDAY...THEN ACROSS THE AREA SUN
NITE. LOW LEVEL MOISTURE AND ISENTROPIC LIFT...ALONG WITH UPPER
DIVERGENCE....ARE MAXIMIZED SUN NITE WITH BEST PRECIP CHC OVER THE
SRN CWFA. WITH PRECIP HOLDING OFF...HIGHS SUN WILL BE UP TO 5
DEGREES ABOVE NORMAL. CLOUDS WILL KEEP LOWS 5 TO AS MUCH AS 10
DEGREES ABOVE NORMAL.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 325 AM FRI...SHORT WAVES SLIDE EAST OF THE AREA MONDAY WITH
RIDGING RETURNING MON NITE. PRECIP TAPERS OFF MONDAY WITH ONLY SOME
LINGERING SHRA ACROSS THE NC MTNS MON NITE. HOWEVER...THERE WILL BE
CONTINUED CLOUDINESS AS LOW LEVELS REMAIN MOIST. HIGHS MONDAY WILL
BE A COUPLE OF DEGREES ABOVE NORMAL WITH LOWS MONDAY NITE AROUND 10
DEGREES ABOVE NORMAL.
THE UPPER RIDGE IS FORECAST TO LINGER THROUGH MIDWEEK. THE ECMWF AND
GFS KEEP A FRONTAL SYSTEM NORTH OF THE AREA TUE AND WED WITH
GENERALLY DIURNAL CONVECTION IN THE MOIST SLY FLOW. THEREFORE...HAVE
SCATTERED AFTERNOON CONVECTION CONFINED TO THE MOUNTAINS. ON THU...A
COLD FRONT WILL APPROACH FROM THE WEST. THE GFS IS INITIALLY FASTER
BRINGING THE FRONT TO E TN BY THE END OF THE DAY THU...BUT THEN
SLOWS CLOSER TO THE ECMWF THU NITE. WPC LIKES THE SLIGHTLY SLOWER
ECMWF SOLN...SO FOLLOWED THEIR GUIDANCE. THIS RAMPS UP CHANCE POPS
ACROSS THE AREA ON THU. TEMPERATURES WARM TO WELL ABOVE NORMAL ON
TUE/WED AND THEN BACK TO NEAR NORMAL FOR THU DUE TO CLOUDS AND
PRECIP.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
AT KCLT...IFR CIG...AND POSSIBLE VSBY RESTRICTIONS IN SHOWERS...ARE
EXPECTED AS A COLD FRONT MOVES THROUGH EARLY THIS MORNING. BASED ON
OBSERVATIONS UPSTREAM AND BEHIND THE FRONT...MVFR CIG RESTRICTIONS
MAY PERSIS AFTER FRONTAL PASSAGE...BUT SHOULD LIFT BY MID MORNING AS
DRIER AIR ARRIVES. S WINDS WILL VEER TO WSW...REMAINING GUSTY. WINDS
BECOME LIGHT NW TONIGHT. GUIDANCE DOW NO SUPPORT RESTRICTIONS EARLY
SATURDAY MORNING AS THE NEW AIR MASS IS TOO DRY.
ELSEWHERE...IFR OT MVFR CIGS WILL PERSIST AHEAD OF AND BEHIND A COLD
FRONT CROSSING THE AREA EARLY THIS MORNING. MVFR VSBY RESTRICTIONS
ARE POSSIBLE IN SHOWERS AHEAD OF THE FRONT. DRIER AIR MAY TAKE A FEW
HOURS TO ARRIVE BEHIND THE FRONT BASED ON TRENDS UPSTREAM...BUT BY
MID MORNING...VFR IS EXPECTED. S WINDS WILL VEER TO WSW IN THE
FOOTHILLS TODAY...AND NW IN THE MOUNTAINS...BECOMING RATHER GUSTY.
WINDS WILL VEER TO THE NW IN NC TONIGHT...REMAINING WSW IN SC...AND
DIMINISHING AT ALL SITE. MODEL GUIDANCE MAINTAINS VFR THROUGH EARLY
SATURDAY MORNING AS THE NEWLY ARRIVED DRIER AIR MASS WILL NOT
SUPPORT FOG.
OUTLOOK...DRY HIGH PRESSURE WILL BUILD INTO THE REGION THROUGH THE
WEEKEND. MOISTURE WILL APPROACH FORM THE SOUTH EARLY NEXT WEEK...BUT
CONFIDENCE IS LIMITED ON THE POSSIBILITY OF RESTRICTIONS.
CONFIDENCE TABLE...
14-20Z 20-02Z 02-08Z 08-14Z
KCLT HIGH 93% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 96% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 95% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 93% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 99% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 96% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...LG
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...JAT
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
655 PM MDT SAT APR 13 2013
.UPDATE...
ISSUED AT 640 PM MDT SAT APR 13 2013
00Z SURFACE MAP PLACES LOW NEAR KGCC. SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS MOVING ACROSS NORTHEAST WYOMING INTO
WESTERN SOUTH DAKOTA. SURFACE LOW TRACKS ACROSS THE BLACK HILLS
AROUND 06Z...AND THEN INTO CENTRAL SOUTH DAKOTA BY 12Z. 18Z
NAM/21Z RAP SHOW STRONG SURFACE PRESSURE FALL/RISE COUPLET MOVING
ACROSS THE BLACK HILLS OVERNIGHT. NAM HAS AREA OF 50KT BOUNDARY
LAYER WINDS ALONG EASTERN SIDE OF THE BLACK HILLS AROUND
09Z...WHILE RAP HAS 40-45KT BOUNDARY LAYER WINDS. NAM/RAP
SOUNDINGS PLACE 50KT WINDS FROM 2000-4000FT AGL AND STEEP LOW
LEVEL LAPSE RATES. AS BEST PRESSURE RISES MOVE THROUGH IN THE WAKE
OF THE LOW...THERE SHOULD BE AN HOUR OR TWO OF WIND GUSTS AROUND
45KT. MAY EVEN SEE PEAK WIND GUST FOR RAPID CITY AROUND 50KTS.
WINDS SHOULD SUBSIDE FOR A WHILE BEFORE PICKING UP AGAIN SUNDAY
MORNING. WILL MOVE UP THE START TIME OF THE WIND ADVISORY TO
ACCOUNT FOR THE STRONGER WINDS IN THE WAKE OF THE LOW. NO CHANGES
EXPECTED AT THIS TIME FOR THE WINTER WEATHER ADVISORY ACROSS FAR
NORTHWEST SOUTH DAKOTA.
&&
.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 335 PM MDT SAT APR 13 2013
CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE MOVING
SLOWLY EAST ACROSS NORTH CENTRAL MT...WITH WARM FRONT STRETCHING
SOUTHEASTWARD INTO EASTERN WY. COLD FRONT EXTENDS BACK TO THE
SOUTHWEST OF THE LOW ACROSS WESTERN WY. UPPER LEVEL ANALYSIS HAS LOW
OVER NORTHERN GREAT LAKES REGION...WEAK RIDGING OVER THE NORTHERN
PLAINS...AND THE NEXT SYSTEM MOVING EAST-SOUTHEAST ACROSS WESTERN
MT. SKIES ARE NOW MOSTLY CLOUDY ACROSS THE AREA. THERE ARE A WIDE
RANGE OF TEMPS ACROSS THE AREA...WITH MOSTLY UPPER 30S AND LOWER 40S
TO THE EAST AND SOUTHEAST OF THE BLACK HILLS...40S AND 50S ACROSS
MUCH OF NORTHEASTERN WY...THE BLACK HILLS...AND FAR NORTHWESTERN SD.
WINDS ARE SOUTH-SOUTHWEST ACROSS NORTHEASTERN WY AND THE BLACK
HILLS... EAST-SOUTHEAST AND BREEZY TO THE NORTH AND EAST OF THE
BLACK HILLS.
APPROACHING STORM SYSTEM IS THE MAIN FOCUS OF THE SHORT TERM
PERIOD...AS IT TRACKS EAST-SOUTHEAST ACROSS MT AND THE NORTHERN
PLAINS. 12Z MODELS ARE IN BETTER AGREEMENT THAN PREVIOUS RUNS...BUT
STILL SOME MINOR TIMING AND TRACK DIFFERENCES WHICH WOULD AFFECT
NORTHERN PORTIONS OF THE CWA...ESPECIALLY NORTHWESTERN SD. LOOKING
AT THE VARIOUS MODELS 700 MB LOW TRACKS...THE GFS IS FURTHEST
SOUTH AND QUICKEST...MOVING THE DEVELOPING LOW ACROSS THE NORTHERN
BLACK HILLS AND EAST INTO CENTRAL SD SUNDAY MORNING. THE UKMET IS
SLIGHTLY FURTHER NORTH...WHILE THE NAM...ECMWF...AND SREF TRACK IT
ACROSS FAR SOUTHEASTERN MT LATE TONIGHT AND ALONG THE ND/SD LINE ON
SUNDAY. WITH THE HEAVIEST PCPN TYPICALLY FALLING JUST TO THE NORTH
OF THE 700 MB LOW...THESE SOLUTIONS WOULD GENERALLY FAVOR THE
HEAVIEST SNOWFALL ACROSS FAR NORTHWESTERN SD AND ESPECIALLY PORTIONS
OF NORTHEASTERN MT THROUGH MUCH OF ND. THIS LEAVES CURRENT FORECAST
IN PRETTY GOOD SHAPE...WITH FAR NORTHWESTERN SD LIKELY SEEING THE
HEAVIEST SNOWFALL...GENERALLY 3 TO 6 INCHES... OVERNIGHT INTO
SUNDAY. OBVIOUSLY ANY DEVIATION TO THE EXPECTED TRACK WILL AFFECT
PCPN AND SNOWFALL AMOUNTS ACROSS NORTHWESTERN SD AND POSSIBLY FAR
NORTHEASTERN WY.
WILL KEEP WINTER WX HEADLINES AS IS...WITH AN ADVISORY FOR 3 TO 6
INCHES OF SNOW ACROSS HARDING AND PERKINS COUNTIES. HIGHEST AMOUNTS
LIKELY NEAR THE ND BORDER...WITH LOCALLY HIGHER AMOUNTS NOT OUT OF
THE QUESTION. FURTHER SOUTH...UP TO 3 INCHES OR SO IS POSSIBLE AFTER
RAIN CHANGES TO SNOW ACROSS FAR NORTHERN CAMPBELL CO...CROOK
COUNTY...AND INTO BUTTE COUNTY. THE NORTHERN BLACK HILLS AREA WILL
LIKELY SEE SOME UPSLOPE ENHANCED SNOWFALL SUNDAY AFTER UPPER LOW
PASSES EAST OF THE AREA. UP TO 4 INCHES ARE IN THE FORECAST...
HIGHEST OVER THE HIGHER ELEVATIONS AND FAVORED UPSLOPE AREAS. THIS
COULD CHANGE A BIT AS WELL IF THE LOW MOVES A BIT FURTHER NORTH OR
SOUTH OF THE FORECAST TRACK. EVEN FURTHER SOUTH...THE BEST CHANCE
FOR PCPN ACROSS SOUTHERN SD WILL GENERALLY BE TONIGHT WITH THE COLD
FRONT PASSAGE. LITTLE OR NO SNOWFALL IS EXPECTED IN THESE AREAS.
HIGHS ON SUNDAY WILL RANGE FROM THE LOWER 30S ACROSS THE BLACK HILLS
AND FAR NORTHWESTERN SD...TO THE MID 40S OVER FAR SOUTHERN SD.
THE OTHER ISSUE WILL BE GUSTY WINDS ON SUNDAY AFTER FRONT PASSES AND
PRESSURE GRADIENT TIGHTENS. COLD AIR ADVECTION IS RELATIVELY
WEAK...BUT SUFFICIENT TO MIX STRONGER WINDS ALOFT DOWN DURING THE
LATE MORNING AND AFTERNOON HOURS. WILL ISSUE A WIND ADVISORY FOR A
GOOD PORTION OF THE NORTHWEST AND WEST CENTRAL SD PLAINS FOR LATE
SUNDAY MORNING AND AFTERNOON...WHEN WIND GUSTS OF 45 TO 50 MPH ARE
EXPECTED. THE ADVISORY MAY NEED TO BE EXTENDED FURTHER SOUTH AND
EAST INTO SOUTH CENTRAL SD...BUT NOT SURE IF THE WINDS WILL BE QUITE
THAT STRONG RIGHT NOW. WILL LET OVERNIGHT SHIFT HAVE ANOTHER LOOK AT
IT.
THE SYSTEM WILL MOVE OFF TO THE EAST BY SUNDAY EVENING...WITH PCPN
COVERAGE AND WINDS DIMINISHING.
&&
.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 335 PM MDT SAT APR 13 2013
A LONG WAVE TROUGH WILL VERY SLOWLY CROSS THE CENTRAL
CONUS THORUGH NEXT WEEKEND...KEEPING UNSETTLED AND RATHER COOL
CONDITIONS ACROSS THE REGION. A RATHER SIGNIFICANT SHORTWAVE WILL
MOVE FROM THE CNTRL ROCKIES INTO THE CNTRL PLAINS IN THE TUE-WED
TIME FRAME. THIS WILL BRING A GOOD CHANCE OF LIGHT SNOW TO THE
AREA...ESPECIALLY SOUTH OF I-90...ALTHOUGH THE MODELS KEEP THE MORE
SIGNIFICANT PCPN TO OUR SOUTH. A NRN STREAM CLIPPER WILL THEN CROSS
THE NRN PLAINS ON FRI/FRI NIGHT BRINGING ANOTHER CHANCE OF PCPN AND
POSSIBLE UPSLOPE CONDITIONS TO THE NRN BLKHLS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 640 PM MDT SAT APR 13 2013
FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING
ISSUED AT 335 PM MDT SAT APR 13 2013
A LOW PRESSURE SYSTEM CROSSING THE AREA WILL BRING A CHANCE OF
RAIN TONIGHT. THE RAIN WILL CHANGE TO SNOW OVER NORTHEASTERN
WYOMING...THE BLACK HILLS AND NORTHWESTERN SOUTH DAKOTA. A PERIOD
OF LIGHT FREEZING RAIN MAY OCCUR OVER PARTS OF FAR NORTHWESTERN
SOUTH DAKOTA. FLIGHT CONDITIONS WILL DETERIORATE TO MVFR AT MOST
LOCATIONS OVERNIGHT...WITH IFR/LIFR CONDITIONS EXPECTED OVER PARTS
OF NORTHEASTERN WYOMING...THE BLACK HILLS AND NORTHWESTERN SOUTH
DAKOTA.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM 3 AM TO 6 PM MDT SUNDAY FOR SDZ012-013-026-
030-031-072-073.
WINTER WEATHER ADVISORY UNTIL 6 PM MDT SUNDAY FOR SDZ001-002.
WY...NONE.
&&
$$
UPDATE...7
SHORT TERM...26
LONG TERM...10
AVIATION...7
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
736 PM CDT SAT APR 13 2013
.UPDATE...
HIGH-BASED THUNDER CHANCES WILL REMAIN BEST IN THE ZONE FROM JUST
NORTH OF MORTON THROUGH LITTLEFIELD AND OLTON TO KRESS FOR THE
NEXT HOUR OR TWO. WE STILL EXPECT ACTIVITY TO DIMINISH AFTER
SUNSET. UPDATED FOR SLIGHTLY FURTHER EAST EXPANSION OF THUNDER
CHANCES AND FOR BETTER COVERAGE OF GUSTY-WIND PRODUCING THUNDER IN
THE FAVORED ZONE INDICATED ABOVE. RMCQUEEN
&&
.AVIATION...
NO SIGNIFICANT CHANGES FROM THE PREVIOUS FORECAST. THUNDER CHANCES
THIS EVENING WILL DRIFT NEAR ENOUGH KLBB TO MENTION CUMULONIMBUS
AS THE LOW CLOUD TYPE...BUT DO NOT EXPECT TO MOVE THROUGH KLBB.
A LOW CLOUD LAYER NEAR IFR/MVFR BOUNDARY IS STILL POSSIBLE NEAR
KLBB BRIEFLY NEAR DAYBREAK ON SUNDAY BEFORE THE DRY WESTERLY
COMPONENT WINDS SET IN. VFR SHOULD CONTINUE AT KCDS THROUGH THE
PERIOD. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 252 PM CDT SAT APR 13 2013/
SHORT TERM...
WEST TEXAS WILL REMAIN UNDER BROAD CYCLONIC FLOW OVER THE SHORT TERM
AS A STORM SYSTEM DIGS THROUGH THE NORTHWESTERN TIER OF THE NATION
AND EMERGES AND STRENGTHENS OVER THE NORTHERN PLAINS SUNDAY. WITHIN
THIS FLOW...A TROUGH AXIS WAS APPROACHING WEST TEXAS AND WILL PASS
TO THE EAST TONIGHT...THOUGH THE BULK OF THE LARGE-SCALE ASCENT WITH
THIS FEATURE WILL EMERGE WELL TO THE SOUTH OF THE FA. EVEN
SO...NORTHERN AND WESTERN SECTIONS OF THE CWA WILL SEE THE
POSSIBILITY OF ISOLATED CONVECTION LATE THIS AFTERNOON THROUGH EARLY
THIS EVENING. LOW-LEVEL MOISTURE IS RATHER LIMITED...WITH DEWPOINTS
ONLY IN THE 30S TO LOWER 40S ACROSS THE CAPROCK...BUT STEEP
MID-LEVEL LAPSE RATES WERE RESULTING IN AROUND 500 J/KG OF SBCAPE
WHILE CIN WAS WEAKENING AND SHOULD BE MINIMAL BY LATE AFTERNOON.
THESE FACTORS COMBINED WITH WEAK CONVERGENCE WERE ALREADY RESULTING
IN A DEVELOPING CUMULUS FIELD FROM NORTH OF HEREFORD TO WEST OF
CLOVIS AS OF 19Z. THE LATEST TTU-WRF...RAP...NAM AND SEVERAL SREF
MEMBERS SUGGEST THAT ISOLATED TO WIDELY SCATTERED CONVECTION WILL
DEVELOP THROUGH MID TO LATE AFTERNOON AND MOVE EASTWARD. EXPECT ANY
ACTIVITY TO QUICKLY WANE THIS EVENING THOUGH THE LATEST RAP AND HRRR
SUGGEST THE ACTIVITY COULD HANG ON AND PASS ACROSS MUCH OF THE SOUTH
PLAINS THIS EVENING. NOT AS CONVINCED OF THIS AND HAVE MAINTAINED
THE ISOLATED THUNDER MENTION GENERALLY ALONG AND WEST OF A MEMPHIS
TO LEVELLAND LINE. RATHER WEAK INSTABILITY...FORCING AND DEEP LAYER
SHEAR SHOULD LIMIT THE STORM ORGANIZATION AND COVERAGE THOUGH
RELATIVELY DRY SUB-CLOUD LAYER /WITH SFC T/TD SPREADS OF 30 TO 40
DEGREES/ COULD SUPPORT LOCALIZED STRONG WIND GUSTS.
A STRONG LLJ WILL THEN DEVELOP ACROSS THE CENTRAL PLAINS TONIGHT
WITH THE SOUTHERN EXTENT OF IT EXTENDING OVER NORTHWEST TEXAS. THIS
JET WILL DRAW BETTER MOISTURE NORTHWARD...WITH MOISTURE ADVECTION
MAXIMIZED ACROSS THE SOUTHWEST ZONES WHERE LOW CLOUDS AND FOG COULD
DEVELOP. BREEZY AND QUICKLY VEERING WINDS TOWARD MORNING SHOULD
LIMIT THE FOG POTENTIAL AND HAVE NOT INCLUDED IN THE GRIDS ATTM.
THIS FLOW WILL ALSO PROVIDE A MILD NIGHT...WITH LOWS IN THE UPPER
40S AND LOWER 50S COMMON. A DRYLINE WILL TIGHTEN TONIGHT IN EASTERN
NM...BUT THE SFC FLOW WILL QUICKLY VEER WESTERLY EARLY SUNDAY AS THE
NORTHERN STORM SYSTEM SHIFTS EASTWARD AND THIS WILL CAUSE THE
DRYLINE TO RACE EASTWARD ACROSS THE SOUTH PLAINS SUNDAY MORNING AND
CLEAR EAST OF THE FA BY MID-AFTERNOON. GUSTY WESTERLY WINDS
SUSTAINED AT 20-25 MPH WILL BE COMMON AND THIS WILL PROPEL HIGHS
WELL INTO THE 80S...WITH EVEN A FEW LOWER 90S POSSIBLE OFF THE
CAPROCK. THESE WARM...DRY AND GUSTY CONDITIONS WILL ALSO CREATE
ELEVATED TO CRITICAL FIRE WEATHER.
LONG TERM...
MAIN INTEREST CONTINUES TO BE UPPER TROUGH AND FRONTAL PASSAGE MID
WEEK AND MODEL INCONSISTENCIES IN HANDLING BOTH FEATURES. 12Z GFS
CAME IN ABOUT 18-24 HOURS SLOWER THAN ITS 00Z RUN AND IS NOW
SLOWER THAN EITHER THE 00Z OR 12Z RUNS OF THE ECMWF. GOOD
CONSISTENCY IN THE ECMWF WILL MAKE IT THE WINNER TODAY...AND GIVEN
THAT THE PREVIOUS FCST TRENDED TOWARD IT...FEW CHANGES WILL BE
MADE TO THAT PART OF THE FCST. IN GENERAL...COOLING TEMPS
WEDNESDAY...THE MAGNITUDE OF WHICH STILL IN DOUBT GIVEN IMPORTANCE
OF FRONTAL TIMING ON THAT ELEMENT. SMALL PRECIP CHANCES CONTINUE
TO FAVOR THE ROLLING PLAINS WHERE SOME LOW LEVEL MOISTURE MAY BE
IN PLACE.
EARLY WEEK WILL CONTINUE TO EXPECT A WEAK FRONTAL BOUNDARY IN OR
NEAR THE NERN PART OF THE FCST AREA THAT SHOULD RESULT IN SLIGHTLY
COOLER TEMPS THERE. LACK OF LOW LEVEL MOISTURE MONDAY SHOULD LIMIT
POPS WHILE BETTER MOISTURE RETURN TUESDAY MAY HELP FUEL ISOLATED
THUNDER. WEST OF THE BOUNDARY...BREEZY AND WARM WITH POSSIBILITY
OF ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS DEVELOPING.
LATTER PART OF THE WEEK LOOKS FAIR AND COOL IN POST-FRONTAL AIR
MASS AND NWLY FLOW ALOFT.
FIRE WEATHER...
THE SOUTH PLAINS REGION WILL SEE GOOD TO EXCELLENT RH RECOVERIES
TONIGHT AS SOUTHERLY FLOW DRAWS IN IMPROVING AMOUNTS OF MOISTURE.
HOWEVER...THIS MOISTURE WILL BE SHUNTED EASTWARD AS A DRYLINE
QUICKLY ADVANCES FROM EASTERN NM /EARLY SUNDAY MORNING/ INTO
SOUTHWEST OK AND WESTERN NORTH TEXAS BY LATE IN THE DAY. RH VALUES
WILL DROP TO 5 TO 10 PERCENT ACROSS THE FA /BEHIND THE DRYLINE/
WHILE TEMPERATURES CLIMB TO 10 TO 15 DEGREES ABOVE AVERAGE.
ADDITIONALLY...SOUTHWEST TO WESTERLY WINDS WILL BECOME SUSTAINED AT
15-25 MPH BEHIND THE DRYLINE DURING THE AFTERNOON...RESULTING IN A
PERIOD OF ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS. HENCE...HAVE
ISSUED A FIRE WEATHER WATCH FOR THE ENTIRE AREA VALID FROM 17-01Z
SUNDAY. EXPECT THE STRONGEST WINDS TO BE ON THE CAPROCK WHERE
LOW-END CRITICAL CONDITIONS /AT LEAST WITH REGARDS TO THE WINDS/
WILL BE MOST LIKELY TO OCCUR FOR THE REQUIRED 3 HOURS OR MORE. IT IS
LESS CERTAIN THAT SPOTS OFF THE CAPROCK WILL OBTAIN MORE THAN
SPOTTY/BRIEF CRITICAL CONDITIONS...BUT HAVE DECIDED TO INCLUDE IN
THE WATCH AND WILL LET THE OVERNIGHT SHIFT DECIDE IF A FIRE DANGER
STATEMENT MAY BE MORE APPROPRIATE.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 44 81 43 80 48 / 20 0 0 0 0
TULIA 49 84 44 82 47 / 30 0 0 0 0
PLAINVIEW 51 85 44 83 50 / 30 0 0 0 0
LEVELLAND 52 85 47 84 49 / 20 0 0 0 0
LUBBOCK 53 87 48 85 52 / 10 0 0 0 0
DENVER CITY 52 85 51 85 51 / 20 0 0 0 0
BROWNFIELD 52 87 49 85 49 / 10 0 0 0 0
CHILDRESS 52 89 48 81 54 / 10 0 0 0 10
SPUR 51 90 50 89 54 / 10 0 0 0 10
ASPERMONT 54 92 53 93 57 / 10 0 0 0 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR THE FOLLOWING ZONES: TXZ021>044.
&&
$$
05/99/05
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
252 PM CDT SAT APR 13 2013
.SHORT TERM...
WEST TEXAS WILL REMAIN UNDER BROAD CYCLONIC FLOW OVER THE SHORT TERM
AS A STORM SYSTEM DIGS THROUGH THE NORTHWESTERN TIER OF THE NATION
AND EMERGES AND STRENGTHENS OVER THE NORTHERN PLAINS SUNDAY. WITHIN
THIS FLOW...A TROUGH AXIS WAS APPROACHING WEST TEXAS AND WILL PASS
TO THE EAST TONIGHT...THOUGH THE BULK OF THE LARGE-SCALE ASCENT WITH
THIS FEATURE WILL EMERGE WELL TO THE SOUTH OF THE FA. EVEN
SO...NORTHERN AND WESTERN SECTIONS OF THE CWA WILL SEE THE
POSSIBILITY OF ISOLATED CONVECTION LATE THIS AFTERNOON THROUGH EARLY
THIS EVENING. LOW-LEVEL MOISTURE IS RATHER LIMITED...WITH DEWPOINTS
ONLY IN THE 30S TO LOWER 40S ACROSS THE CAPROCK...BUT STEEP
MID-LEVEL LAPSE RATES WERE RESULTING IN AROUND 500 J/KG OF SBCAPE
WHILE CIN WAS WEAKENING AND SHOULD BE MINIMAL BY LATE AFTERNOON.
THESE FACTORS COMBINED WITH WEAK CONVERGENCE WERE ALREADY RESULTING
IN A DEVELOPING CUMULUS FIELD FROM NORTH OF HEREFORD TO WEST OF
CLOVIS AS OF 19Z. THE LATEST TTU-WRF...RAP...NAM AND SEVERAL SREF
MEMBERS SUGGEST THAT ISOLATED TO WIDELY SCATTERED CONVECTION WILL
DEVELOP THROUGH MID TO LATE AFTERNOON AND MOVE EASTWARD. EXPECT ANY
ACTIVITY TO QUICKLY WANE THIS EVENING THOUGH THE LATEST RAP AND HRRR
SUGGEST THE ACTIVITY COULD HANG ON AND PASS ACROSS MUCH OF THE SOUTH
PLAINS THIS EVENING. NOT AS CONVINCED OF THIS AND HAVE MAINTAINED
THE ISOLATED THUNDER MENTION GENERALLY ALONG AND WEST OF A MEMPHIS
TO LEVELLAND LINE. RATHER WEAK INSTABILITY...FORCING AND DEEP LAYER
SHEAR SHOULD LIMIT THE STORM ORGANIZATION AND COVERAGE THOUGH
RELATIVELY DRY SUB-CLOUD LAYER /WITH SFC T/TD SPREADS OF 30 TO 40
DEGREES/ COULD SUPPORT LOCALIZED STRONG WIND GUSTS.
A STRONG LLJ WILL THEN DEVELOP ACROSS THE CENTRAL PLAINS TONIGHT
WITH THE SOUTHERN EXTENT OF IT EXTENDING OVER NORTHWEST TEXAS. THIS
JET WILL DRAW BETTER MOISTURE NORTHWARD...WITH MOISTURE ADVECTION
MAXIMIZED ACROSS THE SOUTHWEST ZONES WHERE LOW CLOUDS AND FOG COULD
DEVELOP. BREEZY AND QUICKLY VEERING WINDS TOWARD MORNING SHOULD
LIMIT THE FOG POTENTIAL AND HAVE NOT INCLUDED IN THE GRIDS ATTM.
THIS FLOW WILL ALSO PROVIDE A MILD NIGHT...WITH LOWS IN THE UPPER
40S AND LOWER 50S COMMON. A DRYLINE WILL TIGHTEN TONIGHT IN EASTERN
NM...BUT THE SFC FLOW WILL QUICKLY VEER WESTERLY EARLY SUNDAY AS THE
NORTHERN STORM SYSTEM SHIFTS EASTWARD AND THIS WILL CAUSE THE
DRYLINE TO RACE EASTWARD ACROSS THE SOUTH PLAINS SUNDAY MORNING AND
CLEAR EAST OF THE FA BY MID-AFTERNOON. GUSTY WESTERLY WINDS
SUSTAINED AT 20-25 MPH WILL BE COMMON AND THIS WILL PROPEL HIGHS
WELL INTO THE 80S...WITH EVEN A FEW LOWER 90S POSSIBLE OFF THE
CAPROCK. THESE WARM...DRY AND GUSTY CONDITIONS WILL ALSO CREATE
ELEVATED TO CRITICAL FIRE WEATHER.
&&
.LONG TERM...
MAIN INTEREST CONTINUES TO BE UPPER TROUGH AND FRONTAL PASSAGE MID
WEEK AND MODEL INCONSISTENCIES IN HANDLING BOTH FEATURES. 12Z GFS
CAME IN ABOUT 18-24 HOURS SLOWER THAN ITS 00Z RUN AND IS NOW
SLOWER THAN EITHER THE 00Z OR 12Z RUNS OF THE ECMWF. GOOD
CONSISTENCY IN THE ECMWF WILL MAKE IT THE WINNER TODAY...AND GIVEN
THAT THE PREVIOUS FCST TRENDED TOWARD IT...FEW CHANGES WILL BE
MADE TO THAT PART OF THE FCST. IN GENERAL...COOLING TEMPS
WEDNESDAY...THE MAGNITUDE OF WHICH STILL IN DOUBT GIVEN IMPORTANCE
OF FRONTAL TIMING ON THAT ELEMENT. SMALL PRECIP CHANCES CONTINUE
TO FAVOR THE ROLLING PLAINS WHERE SOME LOW LEVEL MOISTURE MAY BE
IN PLACE.
EARLY WEEK WILL CONTINUE TO EXPECT A WEAK FRONTAL BOUNDARY IN OR
NEAR THE NERN PART OF THE FCST AREA THAT SHOULD RESULT IN SLIGHTLY
COOLER TEMPS THERE. LACK OF LOW LEVEL MOISTURE MONDAY SHOULD LIMIT
POPS WHILE BETTER MOISTURE RETURN TUESDAY MAY HELP FUEL ISOLATED
THUNDER. WEST OF THE BOUNDARY...BREEZY AND WARM WITH POSSIBILITY
OF ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS DEVELOPING.
LATTER PART OF THE WEEK LOOKS FAIR AND COOL IN POST-FRONTAL AIR
MASS AND NWLY FLOW ALOFT.
&&
.FIRE WEATHER...
THE SOUTH PLAINS REGION WILL SEE GOOD TO EXCELLENT RH RECOVERIES
TONIGHT AS SOUTHERLY FLOW DRAWS IN IMPROVING AMOUNTS OF MOISTURE.
HOWEVER...THIS MOISTURE WILL BE SHUNTED EASTWARD AS A DRYLINE
QUICKLY ADVANCES FROM EASTERN NM /EARLY SUNDAY MORNING/ INTO
SOUTHWEST OK AND WESTERN NORTH TEXAS BY LATE IN THE DAY. RH VALUES
WILL DROP TO 5 TO 10 PERCENT ACROSS THE FA /BEHIND THE DRYLINE/
WHILE TEMPERATURES CLIMB TO 10 TO 15 DEGREES ABOVE AVERAGE.
ADDITIONALLY...SOUTHWEST TO WESTERLY WINDS WILL BECOME SUSTAINED AT
15-25 MPH BEHIND THE DRYLINE DURING THE AFTERNOON...RESULTING IN A
PERIOD OF ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS. HENCE...HAVE
ISSUED A FIRE WEATHER WATCH FOR THE ENTIRE AREA VALID FROM 17-01Z
SUNDAY. EXPECT THE STRONGEST WINDS TO BE ON THE CAPROCK WHERE
LOW-END CRITICAL CONDITIONS /AT LEAST WITH REGARDS TO THE WINDS/
WILL BE MOST LIKELY TO OCCUR FOR THE REQUIRED 3 HOURS OR MORE. IT IS
LESS CERTAIN THAT SPOTS OFF THE CAPROCK WILL OBTAIN MORE THAN
SPOTTY/BRIEF CRITICAL CONDITIONS...BUT HAVE DECIDED TO INCLUDE IN
THE WATCH AND WILL LET THE OVERNIGHT SHIFT DECIDE IF A FIRE DANGER
STATEMENT MAY BE MORE APPROPRIATE.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 44 81 43 80 48 / 20 0 0 0 0
TULIA 49 84 44 82 47 / 20 0 0 0 0
PLAINVIEW 51 85 44 83 50 / 10 0 0 0 0
LEVELLAND 52 85 47 84 49 / 20 0 0 0 0
LUBBOCK 53 86 47 84 52 / 10 0 0 0 0
DENVER CITY 52 85 51 85 51 / 20 0 0 0 0
BROWNFIELD 52 87 49 85 49 / 10 0 0 0 0
CHILDRESS 52 89 48 81 54 / 10 0 0 0 10
SPUR 51 90 50 89 54 / 10 0 0 0 10
ASPERMONT 54 92 53 93 57 / 10 0 0 0 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR THE FOLLOWING ZONES: TXZ021>044.
&&
$$
23/07
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
655 PM CDT SAT APR 13 2013
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SUNDAY
ISSUED AT 306 PM CDT SAT APR 13 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE
SPINNING OVER SOUTHEAST ONTARIO WHILE A WEAK SURFACE RIDGE AXIS
EXTENDS FROM CENTRAL CANADA TO THE GULF COAST. EMBEDDED SHORTWAVE
TROUGH OVER NORTHWEST WISCONSIN AND STEEP LOW LEVEL LAPSE RATES ARE
CONTRIBUTING TO SCT SNOW SHOWERS OVER NORTHERN AND ALSO CENTRAL
WISCONSIN THIS AFTERNOON...THOUGH BETWEEN THESE AREAS OVER
EAST-CENTRAL WISCONSIN HAVE REMAINED DRY FOR MOST OF THE DAY. THESE
SNOW SHOWERS SHOULD CONTINUE THROUGH EARLY THIS EVENING.
MEANWHILE...THE NEXT STORM SYSTEM IS MOVING OVER THE NORTHERN
ROCKIES AND IS DUE TO IMPACT THE REGION TOMORROW. PRECIPITATION AND
IMPACTS FROM THIS SYSTEM ARE THE MAIN FORECAST CONCERNS.
TONIGHT...SHORTWAVE TROUGH MOVING THROUGH NORTHWEST WISCONSIN WILL
EXIT OVER NORTHERN LAKE MICHIGAN DURING THE EVENING. INCREASING
SUBSIDENCE AND NOCTURNAL COOLING BEHIND THE WAVE WILL END SNOW
SHOWER CHANCES...BUT STILL PLENTY OF CLOUD COVER UPSTREAM WITHIN LOW
LEVEL CONVERGENCE. SO WILL START SKY CONDITIONS AS MOSTLY CLOUDY
BEFORE TRANSITIONING TO PARTLY CLOUDY SKIES AS SURFACE RIDGE AXIS
BUILDS INTO THE REGION. THEN AFTER MIDNIGHT...CLOUDS WILL BE ON THE
INCREASE AS AN 850MB WARM FRONT LIFTS NE ACROSS THE MID-MISSISSIPPI
VALLEY. SOUTHWEST WINDS AHEAD OF A DEVELOPING LOW PRESSURE SYSTEM
OVER THE CENTRAL PLAINS WILL ADVECT GULF MOISTURE INTO SOUTHWEST
WISCONSIN BY DAYBREAK. THE INCREASE IN MOISTURE COMBINED WITH
INCREASING FORCING NORTH OF THE WARM FRONT WILL LEAD TO PRECIP
APPROACHING CENTRAL WISCONSIN LATE TONIGHT. PROGGED SOUNDINGS
INDICATE A SNOW/SLEET MIX LOOKS TO BE THE PTYPE AT ARRIVAL. LOW
TEMPS TO OCCUR EARLY OVERNIGHT...BEFORE CLOUDS THICKEN LATE.
SUNDAY...SURFACE LOW PRESSURE WILL MOVE NE ACROSS IOWA AND INTO
SOUTHERN OR CENTRAL MINNESOTA...WHILE THE 850MB WARM FRONT WILL LIFT
NORTH INTO NORTHERN WISCONSIN BY LATE AFTERNOON. 50KTS OF SW FLOW
AT 850MB WILL CAUSE AN FGEN INDUCED BAND OF PRECIPITATION TO LIFT
NORTH OVER THE COURSE OF THE MORNING THROUGH ABOUT MID-AFTERNOON.
ALTHOUGH AIR FROM THE RECEDING HIGH IS NOT AS COLD OR DRY AS THE
EVENT OVER THE PAST WEEK...IT STILL SHOULD BE SUFFICIENTLY COLD FOR
PRECIPITATION TYPE TO BE PREDOMINATELY SNOW AND SLEET FOR THE
MORNING...THOUGH SOME RAIN SHOULD MIX IN WITH THE FROZEN PRECIP BY
LATE MORNING OVER CENTRAL AND EAST-CENTRAL WISCONSIN AS SURFACE
TEMPS WARM. COULD SEE AN INCH OR TWO OF ACCUMULATION OVER CENTRAL
WISCONSIN DURING THE AM HOURS. AS TEMPS WARM FURTHER IN THE
AFTERNOON...PRECIP WILL CHANGE TO ALL RAIN OVER CENTRAL AND
NORTHEAST WISCONSIN...WHILE A MIX OF SNOW/SLEET/RAIN WILL CONTINUE
OVER NORTH-CENTRAL WISCONSIN. NORTH-CENTRAL WISCONSIN COULD ALSO
SEE A COUPLE INCHES OF ACCUMULATION. THOUGH PRECIP RATES COULD BE
BEEFY AT TIMES...AM COUNTING ON DAYTIME HEATING TO SUFFICIENTLY WARM
ROAD TEMPS ENOUGH TO PREVENT WIDESPREAD HAZARDOUS TRAVEL. TEMPS
SHOULD TOP OUT IN THE MID 30S NORTH TO LOW 40S SOUTH.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY
ISSUED AT 306 PM CDT SAT APR 13 2013
UPPER LOW WILL LIFT NORTH ACROSS NORTHERN MINNESOTA SUNDAY NIGHT
AS OCCLUDED SURFACE FRONT MOVES THROUGH AND CAUSES THE RAIN TO
TAPER OFF TO SHOWERS. MONDAY WILL BE BLUSTERY BUT MILD AS 925MB
TEMPERATURES RISE A FEW DEGREES ABOVE FREEZING WITH DECENT MIXING
DESPITE MOSTLY CLOUDY SKIES. WENT A COUPLE OF DEGREES COLDER THAN
MOS GUIDANCE AS THERE WILL STILL BE SNOW ON THE GROUND OVER MUCH
OF THE AREA OR AT LEAST COLD AND WET GROUND. MONDAY NIGHT AND
TUESDAY SHOULD BE MOSTLY DRY AS BIG SURFACE HIGH OVER CANADA TRIES
TO EDGE INTO THE NORTHERN GREAT LAKES. MODELS AGREE THAT A SURFACE
WAVE WILL LIFT NORTH FROM THE SOUTHERN PLAINS TO LOWER MICHIGAN
WEDNESDAY AND WEDNESDAY NIGHT. THE TRACK IS A BIT TOO FAR WEST FOR
SIGNIFICANT SNOW BUT THERE SHOULD BE SOME AT THE START AND END
ESPECIALLY IN THE NORTH. THE SYSTEM IS STILL WAY UPSTREAM SO THAT
COULD CHANGE. MUCH COOLER AIR ARRIVES FRIDAY AND SATURDAY AS THE
SYSTEM GOES BY AND ARCTIC HIGH OVER CENTRAL CANADA MAKES A PUSH
TOWARDS THE SOUTH. SOME INSTABILITY SNOW AND RAIN SHOWERS LIKELY
FRIDAY WITH LAKE ENHANCEMENT IN VILAS COUNTY THURSDAY NIGHT AND
FRIDAY.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 644 PM CDT SAT APR 13 2013
EXPECT SCT LGT-MDT SNOW SHOWERS TO DIMINISH RAPIDLY TOWARD SUNSET
AS AN UPPER LEVEL DISTURBANCE EXITS THE REGION AND DAYTIME HEATING
WANES. NOT PLANNING TO MENTION THESE IN THE 00Z TAFS. MAINLY VFR
CONDITIONS ARE ANTICIPATED OVERNIGHT...AND PARTIAL CLEARING IS
EXPECTED. WILL NEED TO WATCH FOR PATCHY FOG DEVELOPMENT IF CLEARING
OCCURS...BUT WILL NOT ADD TO THE TAFS RIGHT NOW.
A WARM FRONT WILL LIFT QUICKLY TO THE NE BY SUNDAY MORNING...
RESULTING IN LOWERING CIGS...AND PRECIPITATION RETURNING TO THE
TAF SITES DURING THE MID TO LATE MORNING. PCPN SHOULD START OFF AS
SNOW OR A SNOW/SLEET MIX...THEN GRADUALLY MIX WITH OR CHANGE OVER
TO RAIN FROM SOUTH TO NORTH DURING THE MID TO LATE AFTERNOON.
CIGS/VSBYS SHOULD SETTLE INTO THE IFR CATEGORY ONCE THE STEADY
PCPN ARRIVES.
HAVE ADDED IN SOME LLWS SUNDAY AFTERNOON...AS SE WINDS INCREASE TO
40 KTS AT 1500-2000 FT AGL.
THERE IS SOME POTENTIAL FOR TSTMS ACROSS PARTS OF C/EC WI SUNDAY
AFTERNOON...BUT THE PROBABILITY OF THEM AFFECTING THE TAF SITES
WAS TOO LOW TO INCLUDE WITH THIS SET OF TAFS. WILL EVALUATE AGAIN
FOR THE 06Z TAFS.
&&
.HYDROLOGY...
FLOODING CONCERNS HAVE EASED AS COLDER AIR HAS SLOWED THE ONGOING
SNOWMELT. HOWEVER...ANOTHER SYSTEM IS FORECAST TO AFFECT THE
REGION ON SUNDAY AND SUNDAY NIGHT AND PROBABLY RESUME THE RISK OF
RIVER FLOODING AS MORE PCPN FALLS. WL RE-ISSUE THE ESF DETAILING
THE SITN. FLOODING CONCERNS COULD CONT LATER NEXT WEEK...AS YET
ANOTHER SYSTEM TAKES AIM ON NE WI. THERE ARE STILL QUESTIONS AS TO
THE EVENTUAL TRACK OF THE SFC LOW AND WHETHER THE ASSOCIATED PCPN
FALLS AS RAIN OR SNOW.
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......KIECKBUSCH
HYDROLOGY......MPC
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1118 PM MDT SAT APR 13 2013
.UPDATE...
ISSUED AT 1106 PM MDT SAT APR 13 2013
WILL CANCEL HIGH WIND WARNING FOR EL PASO AND TELLER COUNTIES AS
LATEST NAM AND WRF CROSS SECTIONS HAVE BACKED OFF ON THE MOUNTAIN
WAVE SET UP OVERNIGHT. FARTHER SOUTH...WARNING STILL LOOKS GOOD AS
MANY LOCATIONS IN THE SANGRE/WEST ALREADY GUSTING 40-50 MPH AS OF
05Z. BAND OF MODERATE TO HEAVY SNOW HAS DROPPED SOUTH INTO THE
CENTRAL MOUNTAINS LATE THIS EVENING...CURRENT WINTER WEATHER
HIGHLIGHTS ARE ON TRACK.
UPDATE ISSUED AT 907 PM MDT SAT APR 13 2013
LET RED FLAG WARNING EXPIRE AT 2000 MDT...AND MADE SOME VERY MINOR
ADJUSTMENTS TO CURRENT FORECAST. LATEST RUC SUGGESTS HIGH WIND
POTENTIAL IS BETTER OVER THE SANGRES/WETS VERSUS RAMPART
RANGE...THOUGH WILL LEAVE WIND HIGHLIGHTS UNCHANGED FOR NOW AS WE
JUST HAD A 69 MPH GUST REPORTED NEAR ROSITA IN THE WET
MOUNTAINS. WINTER WX HIGHLIGHTS FOR THE CENTRAL MOUNTAINS LOOK GOOD
AS BAND OF HEAVY SNOW IS JUST ABOUT TO REACH THE CONTINENTAL
DIVIDE SOUTH OF I-70.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 300 PM MDT SAT APR 13 2013
MAIN CONCERNS INCLUDE THE POTENTIAL FOR HIGH WINDS ALONG AND NR THE
EASTERN MTS TONIGHT...AND SNOW AMOUNTS FOR MAINLY THE CENTRAL MTS.
HAVE BEEN MEETING RED FLAG CRITERIA IN MOST OF THE WARNING AREA THIS
AFTERNOON...ALTHOUGH PUEBLO HAS NOT YET MET THE CRITERIA BECAUSE THE
WINDS HAVE NOT KICKED UP YET. WILL LEAVE THE RED FLAG WARNING AS
IS.
MODEL SHOW UPR LOW OVR NWRN MT MOVING SOUTHEAST INTO FAR WRN SD BY
12Z SUN AND THEN EASTWARD ACRS SD DURING THE DAY.
AHEAD OF THIS SYSTEM SNOW WILL BE MOVING INTO THE CONTDVD THIS
EVENING AND WILL CONTINUE THRU MIDDAY SUNDAY WITH THE NAM AND THE
GFS CONTINUING TO HIT THE CENTRAL CO MTS QUITE HARD WITH SNOW TONIGHT.
SOME SNOW SHOWERS WILL PROBABLY ALSO MOVE INTO WRN AND NRN PORTIONS
OF FREMONT COUNTY TONIGHT AND INTO THE TELLER COUNTY AND PIKES PEAK
AREA...BUT LITTLE ACCUMULATIONS IS EXPECTED. THE OTHER MAIN CONCERN
IS THE 100+ KT JET MOVING OVERHEAD. LOOKING AT CROSS-SECTIONS OFF
THE LOCAL WRF...IT SHOWS 55 TO 65 KT WINDS COMING DOWN THE SIDE OF
PIKES PEAK AND THE RAMPART RANGE INTO FAR WRN EL PASO
COUNTY...MAINLY WEST OF I-25 BEGINNING AROUND 02Z AND THEN SEVERE
GUSTS PROBABLY ENDING AROUND 08Z-09Z. WL BEGIN HIGH WIND WARNING AT
02Z FOR THAT AREA AND RUN IT THROUGH 12Z. FARTHER SOUTH...OVR THE
SANGRES...WETS AND SRN I-25 CORRIDOR THE WRF SHOWS THE HIGH WIND
POTENTIAL CONTINUING A LITTLE LONGER SO WL LEAVE THAT AREA IN A
WARNING THRU 15Z.
AS THAT UPR LOW MOVES E ON SUN...THE MSTR ALONG THE CONTDVD
DECREASES AS DO THE SNOW CHANCES...AND THUS THERE COULD BE JUST SOME
LIGHT ADDITIONAL ACCUMULATIONS IN THE MORNING HOURS...BUT LITTLE IF
ANY IN THE AFTERNOON AS THE NAM ENDS ALL PCPN CHANCES. A COLD FRONT
WL DROP SOUTH INTO THE SERN PLAINS SUN AFTERNOON AND TEMPS WL BE A
LITTLE COOLER THAN TODAY. ON SUNDAY IT WL BE A BIT BREEZY FROM THE
I-25 CORRIDOR AND WESTWARD...AND WINDY OVR THE MOUNTAIN AREAS.
HOWEVER RH VALUES LOOK TOO HIGH TO HAVE FIRE WEATHER CONCERNS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 300 PM MDT SAT APR 13 2013
...WINTER IS COMING BACK...
MODELS IN OVERALL AGREEMENT WITH THE FORECAST THROUGH THE EXTENDED
WITH ANOTHER LATE SEASON WINTER STORM THROUGH THE MIDDLE OF THE
WORK WEEK.
AN UPPER LEVEL STORM SYSTEM IS FORECAST TO STRENGTHEN AND DROP
SOUTH OVER THE GREAT BASIN SUNDAY NIGHT THROUGH TUESDAY NIGHT
BEFORE SHIFTING EAST ACROSS THE REGION ON WEDNESDAY. MOST OF
SUNDAY NIGHT WILL BE QUIET ACROSS THE REGION WITH INCREASING
CHANCES FOR SNOWFALL ALONG THE CONTINENTAL DIVIDE BY MONDAY
MORNING. AS THE TROUGH DIGS OUT WEST...FLOW WILL BECOMING
INCREASINGLY SOUTHWESTERLY. A DISTURBANCE IN THE FLOW WILL EJECT
ACROSS CENTRAL COLORADO ON MONDAY WITH A PERIOD OF MODERATE TO
HEAVY SNOWFALL FOR THE CENTRAL MOUNTAINS INTO NORTHEAST COLORADO.
THE LATEST MODEL SOLUTIONS KEEP ALMOST ALL THE PLAINS DRY WITH THE
EXCEPTION BEING THE PALMER DIVIDE WHERE SHOWERS ARE POSSIBLE.
SEVERAL INCHES OF SNOWFALL ARE LIKELY ALONG THE CONTINENTAL DIVIDE
THROUGH MONDAY AFTERNOON...WITH THE HIGHEST AMOUNTS EXPECTED OVER
THE CENTRAL MOUNTAINS. GIVEN THE SOUTHWESTERLY FLOW AND MIXING
ACROSS THE REGION...FIRE WEATHER REMAINS A CONCERN. MODELS HINTING
AT THE RATON MESA REGION AND SAN LUIS VALLEY WILL SEE GUSTY WINDS
HOWEVER HUMIDITY VALUES MAY BE A BIT TOO HIGH. CONDITIONS WILL
NEED TO BE MONITORED. AFTERNOON TEMPERATURES HAVE COME IN A BIT
WARMER WITH 6OS TO LOW 70S FORECAST FOR THE PLAINS.
A COLD FRONT WILL SHIFT SOUTH ACROSS THE PLAINS BY MONDAY EVENING
WITH EASTERLY UPSLOPE FLOW AND MOISTURE FILLING IN BEHIND THE
FRONT. MODEL SOLUTIONS AND SOUNDING DATA INDICATES LOW STRATUS
ALONG WITH FOG AND DRIZZLE WILL LIKELY DEVELOP. THERE COULD BE
SOME LIGHT RAIN AS WELL THROUGH THE OVERNIGHT PERIOD. THIS WILL
LIKELY HELP KEEP TEMPERATURES AT OR ABOVE FREEZING FOR THE PLAINS
MONDAY NIGHT INTO TUESDAY MORNING. SNOW WILL CONTINUE ALONG THE
CONTINENTAL DIVIDE.
THE UPPER LEVEL TROUGH WILL SHIFT EAST INTO THE FOUR CORNERS
REGION TUESDAY AFTERNOON. MODELS INDICATING LOWER LEVEL MIXING
WILL SHIFT THE COOLER UPSLOPE ARE BACK EAST ACROSS THE SOUTHWEST
PORTION OF THE PLAINS. NEAR CRITICAL FIRE WEATHER CONDITIONS MAY
ONCE AGAIN BE POSSIBLE OVER THE SAN LUIS VALLEY AND NEAR THE NEW
MEXICO BORDER BY TUESDAY AFTERNOON. WINDS WILL BE THERE...BUT
CONDITIONS WILL REMAIN DEPENDENT ON HUMIDITY VALUES. SNOW WILL
REMAIN PERSISTENT OVER THE CONTINENTAL DIVIDE THROUGH TUESDAY. THE
NORTHEAST HALF OF THE PLAINS WILL BE TRICKY AS FAR AS CLOUD COVER
AND TEMPERATURE FORECAST. IT ALL DEPENDS ON HOW FAR NORTHEAST THE
MIXING CAN OCCUR. AREAS UNDER CLOUDS SHOULD REMAIN COOL.
BY WEDNESDAY THE UPPER SYSTEM TRACKS OVERHEAD AND EAST INTO THE
CENTRAL CONUS BY THURSDAY MORNING. A MUCH STRONGER COLD FRONT WILL
MOVE SOUTH ACROSS THE AREA WEDNESDAY WITH WIDESPREAD SHOWER ACTIVITY
LIKELY ACROSS ALL OF SOUTHERN COLORADO. CURRENT PROGS INDICATE
AREAS OVER THE PALMER DIVIDE...EASTERN MOUNTAINS AND RATON WILL
LIKELY BE FAVORED. TEMPERATURES ARE FORECAST TO DROP QUICKLY
BEHIND THE FRONT WITH 700 MB TEMPERATURES REACHING -13C BY
WEDNESDAY AFTERNOON. THIS WILL LIKELY TURN ALL PRECIPITATION TO
SNOW BY WEDNESDAY EVENING. ALL ACCUMULATIONS ARE EXPECTED TO
REMAIN OVER THE HIGHER ELEVATIONS. TEMPERATURES WEDNESDAY NIGHT
INTO THURSDAY MORNING WILL BE VERY COLD. CURRENT MODEL GUIDANCE IS
INDICATING LOWER 20S FOR THE PLAINS...AND IT MAY BE A FEW DEGREES
COOLER THAN THIS. PRECAUTIONS SHOULD BE TAKEN TO PROTECT SENSITIVE
PLANTS AND SPRINKLER SYSTEMS.
AS THE UPPER SYSTEM TRACK EAST...NORTHWESTERLY FLOW WILL DEVELOP
AND REMAIN IN PLACE THROUGH SATURDAY. THIS WILL LEAD TO DRY
CONDITIONS FOR MOST AREAS...WITH ISOLATED SNOW SHOWER ACTIVITY
POSSIBLE OVER THE CENTRAL MOUNTAINS. ANY DISTURBANCES IN THE FLOW
WILL LIKELY CAUSE UPTICKS IN AREAL COVERAGE AND INTENSITY AND WILL
NEED TO BE WATCHED. TEMPERATURES WILL SLOWLY MODERATE BACK INTO
THE 50S TO LOWER 60S FOR FRIDAY AND SATURDAY. TEMPERATURES ON
THURSDAY NIGHT WILL ONCE AGAIN BE COLD WITH WIDESPREAD FREEZING
TEMPERATURES. MOZLEY
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1106 PM MDT SAT APR 13 2013
EXPECT VFR CONDTIONS AT ALL TAF SITES TONIGHT AND SUNDAY. WEST
WINDS WILL CONTINUE TO BE OCCASIONALLY GUSTY AT ALL 3 SITES
THROUGH THE NIGHT...A FEW GUSTS TO 25-35 KNOTS WILL BE LIKELY.
WINDS GRADUALLY BECOME MORE NORTHWESTERLY AFTER 09Z...THEN WILL
BRIEFLY DIMINISH AROUND 12Z...BEFORE INCREASING AGAIN INTO THE 15
TO 25 KNOT RANGE ON SUNDAY. A FEW SHOWERS MAY REACH THE PALMER
DIVIDE NORTH OF KCOS IN THE 09Z-12Z PERIOD...THOUGH EXPECT MOST
PRECIP TO STAY NORTH OF THE TERMINAL. OVER THE MOUNTAINS...EXPECT
IFR CONDITIONS DUE TO SNOW TO CONTINUE THROUGH MIDDAY OVER THE
CENTRAL MOUNTAINS FROM MONARCH PASS NORTHWARD.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 9 AM MDT SUNDAY FOR COZ072>075-078>080-
087-088.
WINTER WEATHER ADVISORY UNTIL NOON MDT SUNDAY FOR COZ059.
WINTER STORM WARNING UNTIL NOON MDT SUNDAY FOR COZ058-060.
&&
$$
UPDATE...ROSE
SHORT TERM...28
LONG TERM...MOZLEY
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
913 PM MDT SAT APR 13 2013
.UPDATE...
ISSUED AT 907 PM MDT SAT APR 13 2013
LET RED FLAG WARNING EXPIRE AT 2000 MDT...AND MADE SOME VERY MINOR
ADJUSTMENTS TO CURRENT FORECAST. LATEST RUC SUGGESTS HIGH WIND
POTENTIAL IS BETTER OVER THE SANGRES/WETS VERSUS RAMPART
RANGE...THOUGH WILL LEAVE WIND HIGHLIGHTS UNCHANGED FOR NOW AS WE
JUST HAD A 69 MPH GUST REPORTED NEAR ROSITA IN THE WET
MOUNTAINS. WINTER WX HIGHLIGHTS FOR THE CENTRAL MOUNTAINS LOOK GOOD
AS BAND OF HEAVY SNOW IS JUST ABOUT TO REACH THE CONTINENTAL
DIVIDE SOUTH OF I-70.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 300 PM MDT SAT APR 13 2013
MAIN CONCERNS INCLUDE THE POTENTIAL FOR HIGH WINDS ALONG AND NR THE
EASTERN MTS TONIGHT...AND SNOW AMOUNTS FOR MAINLY THE CENTRAL MTS.
HAVE BEEN MEETING RED FLAG CRITERIA IN MOST OF THE WARNING AREA THIS
AFTERNOON...ALTHOUGH PUEBLO HAS NOT YET MET THE CRITERIA BECAUSE THE
WINDS HAVE NOT KICKED UP YET. WILL LEAVE THE RED FLAG WARNING AS
IS.
MODEL SHOW UPR LOW OVR NWRN MT MOVING SOUTHEAST INTO FAR WRN SD BY
12Z SUN AND THEN EASTWARD ACRS SD DURING THE DAY.
AHEAD OF THIS SYSTEM SNOW WILL BE MOVING INTO THE CONTDVD THIS
EVENING AND WILL CONTINUE THRU MIDDAY SUNDAY WITH THE NAM AND THE
GFS CONTINUING TO HIT THE CENTRAL CO MTS QUITE HARD WITH SNOW TONIGHT.
SOME SNOW SHOWERS WILL PROBABLY ALSO MOVE INTO WRN AND NRN PORTIONS
OF FREMONT COUNTY TONIGHT AND INTO THE TELLER COUNTY AND PIKES PEAK
AREA...BUT LITTLE ACCUMULATIONS IS EXPECTED. THE OTHER MAIN CONCERN
IS THE 100+ KT JET MOVING OVERHEAD. LOOKING AT CROSS-SECTIONS OFF
THE LOCAL WRF...IT SHOWS 55 TO 65 KT WINDS COMING DOWN THE SIDE OF
PIKES PEAK AND THE RAMPART RANGE INTO FAR WRN EL PASO
COUNTY...MAINLY WEST OF I-25 BEGINNING AROUND 02Z AND THEN SEVERE
GUSTS PROBABLY ENDING AROUND 08Z-09Z. WL BEGIN HIGH WIND WARNING AT
02Z FOR THAT AREA AND RUN IT THROUGH 12Z. FARTHER SOUTH...OVR THE
SANGRES...WETS AND SRN I-25 CORRIDOR THE WRF SHOWS THE HIGH WIND
POTENTIAL CONTINUING A LITTLE LONGER SO WL LEAVE THAT AREA IN A
WARNING THRU 15Z.
AS THAT UPR LOW MOVES E ON SUN...THE MSTR ALONG THE CONTDVD
DECREASES AS DO THE SNOW CHANCES...AND THUS THERE COULD BE JUST SOME
LIGHT ADDITIONAL ACCUMULATIONS IN THE MORNING HOURS...BUT LITTLE IF
ANY IN THE AFTERNOON AS THE NAM ENDS ALL PCPN CHANCES. A COLD FRONT
WL DROP SOUTH INTO THE SERN PLAINS SUN AFTERNOON AND TEMPS WL BE A
LITTLE COOLER THAN TODAY. ON SUNDAY IT WL BE A BIT BREEZY FROM THE
I-25 CORRIDOR AND WESTWARD...AND WINDY OVR THE MOUNTAIN AREAS.
HOWEVER RH VALUES LOOK TOO HIGH TO HAVE FIRE WEATHER CONCERNS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 300 PM MDT SAT APR 13 2013
...WINTER IS COMING BACK...
MODELS IN OVERALL AGREEMENT WITH THE FORECAST THROUGH THE EXTENDED
WITH ANOTHER LATE SEASON WINTER STORM THROUGH THE MIDDLE OF THE
WORK WEEK.
AN UPPER LEVEL STORM SYSTEM IS FORECAST TO STRENGTHEN AND DROP
SOUTH OVER THE GREAT BASIN SUNDAY NIGHT THROUGH TUESDAY NIGHT
BEFORE SHIFTING EAST ACROSS THE REGION ON WEDNESDAY. MOST OF
SUNDAY NIGHT WILL BE QUIET ACROSS THE REGION WITH INCREASING
CHANCES FOR SNOWFALL ALONG THE CONTINENTAL DIVIDE BY MONDAY
MORNING. AS THE TROUGH DIGS OUT WEST...FLOW WILL BECOMING
INCREASINGLY SOUTHWESTERLY. A DISTURBANCE IN THE FLOW WILL EJECT
ACROSS CENTRAL COLORADO ON MONDAY WITH A PERIOD OF MODERATE TO
HEAVY SNOWFALL FOR THE CENTRAL MOUNTAINS INTO NORTHEAST COLORADO.
THE LATEST MODEL SOLUTIONS KEEP ALMOST ALL THE PLAINS DRY WITH THE
EXCEPTION BEING THE PALMER DIVIDE WHERE SHOWERS ARE POSSIBLE.
SEVERAL INCHES OF SNOWFALL ARE LIKELY ALONG THE CONTINENTAL DIVIDE
THROUGH MONDAY AFTERNOON...WITH THE HIGHEST AMOUNTS EXPECTED OVER
THE CENTRAL MOUNTAINS. GIVEN THE SOUTHWESTERLY FLOW AND MIXING
ACROSS THE REGION...FIRE WEATHER REMAINS A CONCERN. MODELS HINTING
AT THE RATON MESA REGION AND SAN LUIS VALLEY WILL SEE GUSTY WINDS
HOWEVER HUMIDITY VALUES MAY BE A BIT TOO HIGH. CONDITIONS WILL
NEED TO BE MONITORED. AFTERNOON TEMPERATURES HAVE COME IN A BIT
WARMER WITH 6OS TO LOW 70S FORECAST FOR THE PLAINS.
A COLD FRONT WILL SHIFT SOUTH ACROSS THE PLAINS BY MONDAY EVENING
WITH EASTERLY UPSLOPE FLOW AND MOISTURE FILLING IN BEHIND THE
FRONT. MODEL SOLUTIONS AND SOUNDING DATA INDICATES LOW STRATUS
ALONG WITH FOG AND DRIZZLE WILL LIKELY DEVELOP. THERE COULD BE
SOME LIGHT RAIN AS WELL THROUGH THE OVERNIGHT PERIOD. THIS WILL
LIKELY HELP KEEP TEMPERATURES AT OR ABOVE FREEZING FOR THE PLAINS
MONDAY NIGHT INTO TUESDAY MORNING. SNOW WILL CONTINUE ALONG THE
CONTINENTAL DIVIDE.
THE UPPER LEVEL TROUGH WILL SHIFT EAST INTO THE FOUR CORNERS
REGION TUESDAY AFTERNOON. MODELS INDICATING LOWER LEVEL MIXING
WILL SHIFT THE COOLER UPSLOPE ARE BACK EAST ACROSS THE SOUTHWEST
PORTION OF THE PLAINS. NEAR CRITICAL FIRE WEATHER CONDITIONS MAY
ONCE AGAIN BE POSSIBLE OVER THE SAN LUIS VALLEY AND NEAR THE NEW
MEXICO BORDER BY TUESDAY AFTERNOON. WINDS WILL BE THERE...BUT
CONDITIONS WILL REMAIN DEPENDENT ON HUMIDITY VALUES. SNOW WILL
REMAIN PERSISTENT OVER THE CONTINENTAL DIVIDE THROUGH TUESDAY. THE
NORTHEAST HALF OF THE PLAINS WILL BE TRICKY AS FAR AS CLOUD COVER
AND TEMPERATURE FORECAST. IT ALL DEPENDS ON HOW FAR NORTHEAST THE
MIXING CAN OCCUR. AREAS UNDER CLOUDS SHOULD REMAIN COOL.
BY WEDNESDAY THE UPPER SYSTEM TRACKS OVERHEAD AND EAST INTO THE
CENTRAL CONUS BY THURSDAY MORNING. A MUCH STRONGER COLD FRONT WILL
MOVE SOUTH ACROSS THE AREA WEDNESDAY WITH WIDESPREAD SHOWER ACTIVITY
LIKELY ACROSS ALL OF SOUTHERN COLORADO. CURRENT PROGS INDICATE
AREAS OVER THE PALMER DIVIDE...EASTERN MOUNTAINS AND RATON WILL
LIKELY BE FAVORED. TEMPERATURES ARE FORECAST TO DROP QUICKLY
BEHIND THE FRONT WITH 700 MB TEMPERATURES REACHING -13C BY
WEDNESDAY AFTERNOON. THIS WILL LIKELY TURN ALL PRECIPITATION TO
SNOW BY WEDNESDAY EVENING. ALL ACCUMULATIONS ARE EXPECTED TO
REMAIN OVER THE HIGHER ELEVATIONS. TEMPERATURES WEDNESDAY NIGHT
INTO THURSDAY MORNING WILL BE VERY COLD. CURRENT MODEL GUIDANCE IS
INDICATING LOWER 20S FOR THE PLAINS...AND IT MAY BE A FEW DEGREES
COOLER THAN THIS. PRECAUTIONS SHOULD BE TAKEN TO PROTECT SENSITIVE
PLANTS AND SPRINKLER SYSTEMS.
AS THE UPPER SYSTEM TRACK EAST...NORTHWESTERLY FLOW WILL DEVELOP
AND REMAIN IN PLACE THROUGH SATURDAY. THIS WILL LEAD TO DRY
CONDITIONS FOR MOST AREAS...WITH ISOLATED SNOW SHOWER ACTIVITY
POSSIBLE OVER THE CENTRAL MOUNTAINS. ANY DISTURBANCES IN THE FLOW
WILL LIKELY CAUSE UPTICKS IN AREAL COVERAGE AND INTENSITY AND WILL
NEED TO BE WATCHED. TEMPERATURES WILL SLOWLY MODERATE BACK INTO
THE 50S TO LOWER 60S FOR FRIDAY AND SATURDAY. TEMPERATURES ON
THURSDAY NIGHT WILL ONCE AGAIN BE COLD WITH WIDESPREAD FREEZING
TEMPERATURES. MOZLEY
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 300 PM MDT SAT APR 13 2013
VFR CONDITIONS ARE EXPECTED AT KALS AND KPUB DURING THE FORECAST
PERIOD. GUSTY SW TO W WINDS WL CONTINUE AT KALS INTO THE EARLY
EVENING HOURS...AND ARE THEN EXPECTED TO BECOME GUSTY AGAIN BY
MID MORNING SUNDAY. KPUB COULD STILL SEE WEST TO SW WINDS INCREASE
AFTER 22Z FOR A FEW HOURS. KCOS WILL CONTINUE TO HAVE GUSTY SW WINDS
INTO THE EVENING HOURS. HIGH WINDS WILL BE POSSIBLE IN THE VCNTY OF
KCOS...MAINLY TO THE WEST AND NW BEGINNING AROUND 02Z AND CONTINUING
THROUGH LATE NIGHT. WIND SHEAR COULD BE A PROBLEM AS THE WINDS AT
KCOS COULD BE LIGHT WESTERLY AT THE SFC OR A ROTOR COULD SET UP WITH
LIGHT EASTERLY WINDS...AND THEN THE WINDS JUST A COUPLE THOUSAND
FEET ABOVE THE SFC ARE EXPECTED TO BE VERY STRONG AND WESTERLY.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON MDT SUNDAY FOR COZ059.
HIGH WIND WARNING UNTIL 9 AM MDT SUNDAY FOR COZ072>075-078>080-
087-088.
WINTER STORM WARNING UNTIL NOON MDT SUNDAY FOR COZ058-060.
HIGH WIND WARNING UNTIL 6 AM MDT SUNDAY FOR COZ081-082-084-085.
&&
$$
UPDATE...PETERSEN
SHORT TERM...28
LONG TERM...MOZLEY
AVIATION...28
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1257 AM EDT SUN APR 14 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 415 PM EDT SAT APR 13 2013
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOWS CLOSED LO
CENTERED OVER ONTARIO TO THE S OF PERSISTENT BLOCKING RDG OVER NE
CANADA IN PREVAILING NEGATIVE NAO PATTERN. WITH DEEP MSTR SHOWN ON
12Z INL/GRB RAOBS...CYC FLOW...H85-7 COLD POCKET WITH H85 TEMPS AS
LO AS -10C TO -12C OVER THE WRN CWA...AND SHRTWVS ROTATING ARND THE
MAIN CLOSED LO...CLDS AND SHSN HAVE LINGERED OVER UPR MI...E
SPECIALLY ALONG SFC LO PRES TROF ASSOCIATED WITH ONE OF THESE
SHRTWVS THAT IS CROSSING THE CWA EARLY THIS AFTN. TEMPS REMAIN WELL
BLO NORMAL FOR MID APRIL. OVER FAR WRN MN INTO THE NRN PLAINS...A
SFC RDG AXIS AND DRY MID LVL AIR SHOWN ON THE 12Z BISMARCK RAOB ARE
CAUSING DRY WX EVEN THOUGH SOME LO CLDS LINGER WITH MSTR TRAPPED BLO
INVRN BASE AT H8 SHOWN ON THE BISMARCK SOUNDING. ANOTHER POWERFUL
SHRTWV IS MOVING ONSHORE INTO THE PAC NW WITH 00Z-12Z H3-5 HGT FALLS
UP TO 150-200M.
MAIN FCST CONCERNS THRU TNGT ARE FOCUSED ON SHSN/CLD TRENDS AS THE
UPR LO OVER ONTARIO SLOWLY FILLS AND SHIFTS TO THE E. FOCUS ON
SUN/SUN NGT SHIFTS TO TIMING AND IMPACT OF SHRTWV NOW MOVING INTO
THE PAC NW.
LATE TODAY/TNGT...AS UPR LO IN ONTARIO SLOWLY WEAKENS...H5 HGT IS
PROGGED TO RISE 120M OVER UPR MI BTWN 00Z-12Z SUN UNDER VIGOROUS
DEEP LYR QVECTOR DVGC. AS THE CYC NW FLOW WEAKENS...EXPECT LINGERING
SHSN LATE THIS AFTN/EVNG TO DIMINISH STEADILY THRU THE NGT AND END
IN THE EARLY MRNG HRS ON SUN. WITH SOME CLRG LATE AT LEAST OVER THE
W AND CENTRL AND LGT WINDS UNDER THE SFC RDG AXIS...EXPECT TEMPS TO
FALL INTO THE TEENS...WELL BLO NORMAL FOR THE SEASON. WITH CLDS/LLVL
MSTR LINGERING LONGER IN A PERSISTENT NW FLOW OVER THE E...THOSE
AREAS WL BE WARMER.
SUN/SUN NGT...EXPECT A DRY START TO THE DAY WITH SFC HI PRES RDG
SLOWLY DEPARTING TO THE E. BUT ANY MRNG SUNSHINE WL QUICKLY FADE
BEHIND INCRSG CLDS AS VIGOROUS ISENTROPIC ASCENT/DEEPER MSTR/SW FLOW
ALF BTWN THE DEPARTING HI AND INCRSG NEGATIVELY TILTED SHRTWV/SFC LO
MOVING THRU THE NRN PLAINS AND TOWARD MN LATE IN THE DAY OVERSPREADS
UPR MI. AS UPR DVGC/BAND OF H85-7 FGEN AHEAD OF ATTENDANT WARM FNT
MOVES IN AFT 18Z...EXPECT PCPN TO OVERSPREAD THE CWA BY 00Z MON...
ESPECIALLY OVER THE W HALF CLOSER TO SHARPER DYNAMICS AND WHERE
MOISTENING/H85 MSTR CNVGC IS MOST IMPRESSIVE. PTYPE WL BE A CONCERN
SUN AFTN/EVNG. NAM/GFS FCST SDNGS INDICATE SATURATED TEMP PROFILE WL
AT LEAST INITIALLY BE COMPLETELY SUB ZERO...BUT THEN SHOW ELEVATED
WARM LYR ABV SUB ZERO NEAR SFC LYR. WITH ELEVATED WARMING INITIALLY
LIFTING TEMPS ABV 0C IN THE H8-75 LYR...SUSPECT SLEET WL MIX WITH
THE SN. THESE FCST SDNGS ALSO SUG PCPN MAY BE AT LEAST MIXED WITH
SOME FZRA FOR A TIME LATE IN THE AFTN/EVNG OVER AT LEAST THE HIER
TERRAIN OF THE W HALF AS THE ELEVATED WARM LYR DEEPENS AND TEMPS IN
THE LOWER LYR WARM TOO MUCH FOR DROPS TO REFREEZE. BUT THESE SDNGS
ALSO APPEAR TO UNDERDO THE SFC WARMING IN THE AFTN FOLLOWING AT
LEAST SOME MRNG SUNSHINE. WITH SOME LINGERING LLVL DRY AIR...
EVAPORATIVE COOLING COULD MAINTAIN SUB 32 NEAR SFC WBLB TEMPS. BUT
THE FCST NEAR SFC SE FLOW IN THE ABSENCE OF HI PRES CENTER OVER
ONTARIO AS WELL AS ARRIVAL OF PCPN AT MAX HEATING TIME THIS LATE IN
THE SEASON WOULD ALSO TEND TO MINIMIZE THIS THREAT. HIER GFS MOS
TEMPS SEEM MORE APPROPRIATE FOR THE TEMPS FCST THAN RAW MODEL
GUIDANCE. FOR NOW...WL FCST A SN/SLEET MIX AT THE ONSET
TRANSITIONING TO RA SUN EVNG AS MUCH WARMER/MSTR LLVL AIR SURGES
INTO THE UPR LKS ON THE HEELS OF H85 SW WINDS FCST UP TO 60-70KTS BY
06Z MON. EXPECT LITTLE IF ANY FALL OF TEMPS SUN NGT. THE NW CWA WL
HAVE THE BEST CHC FOR SEEING A LONGER PERIOD OF WINTRY PCPN WITH
H85-75 TEMPS REMAINING BLO 0C THERE FOR A LONGER TIME. NOT OUT OF
THE QUESTION ADVY SN MAY FALL OVER THE HIER TERRAIN OF THE KEWEENAW
SUN AFTN/EVNG. NEGATIVELY TILTED APPEARANCE OF SHRTWV/VERY DIFFLUENT
SW FLOW ALF/MSTR SURGE WITH FCST PWAT 0.75 TO 1 INCH SUN EVNG...OR
UP TO 200 PCT OF NORMAL...INDICATE QPF NEAR 1 INCH IN SOME PLACES IS
ON TRACK. RUNOFF FM THIS RA IN THE PRESENCE OF LINGERING SN PILES
MAY CAUSE SOME PONDING OF WATER. ALTHOUGH FCST H85-5 LAPSE RATES ARE
NOT MUCH MORE UNSTABLE THAN MOIST ADIABATIC...DECIDED TO INCLUDE
MENTION OF ELEVATED TS UNDER THE MOST IMPRESSIVE MOISTENING/AXIS OF
H85 LLJ GIVEN IMPRESSIVE DYNAMICS/NEGATIVE TILT OF SHRTWV. ARRIVAL
OF DRY SLOT SUN NGT WL DIMINISH POPS SW-NE AFTER THE EVNG. IN
FACT...FCST SDNGS INDICATE THERE MAY BE SOME CLRG OVER THE SW LATE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 415 PM EDT SAT APR 13 2013
ACTIVE PATTERN ACROSS THE CONUS CONTINUES INTO NEXT WEEKEND AS A
LARGE SCALE UPPER TROUGH MOVES FROM THE W COAST MON TO THE CENTRAL
CONUS BY NEXT SAT...WITH PIECES OF SMALLER SCALE ENERGY EJECTING OFF
THE TROUGH THROUGH THE REGION.
STARTING THE PERIOD OFF 12Z MON...A STACKED CLOSED LOW WILL BE OVER
NRN MN WITH AN OCCLUDED FRONT FROM THE LOW TO NRN LAKE
SUPERIOR...AND THE ASSOCIATED WARM FRONT EXTENDING E FROM NRN LAKE
SUPERIOR INTO ONTARIO AND THE COLD FRONT FROM NRN LAKE SUPERIOR TO
FAR ERN UPPER MI. AT THIS POINT...THE PRECIP THAT MOVED OVER THE CWA
AHEAD OF THE COLD FRONT WILL BE MOSTLY E OF THE CWA. THE DRY SLOT
BEHIND THE COLD FRONT WILL BRING VERY DRY AIR INITIALLY THROUGH MOST
OF THE SOUNDING...BUT WRAP AROUND LOW LEVEL MOISTURE BELOW 800MB WILL
RETURN TO AT LEAST NW UPPER MI /MODELS DIFFER ON THE AREAL EXTENT OF
THE MOISTURE/ AS THE LOW MOVES N OF LAKE SUPERIOR TO JAMES BAY BY
12Z TUE. THIS MAY RESULT IN SOME CONVECTIVE WINTRY MIX SHOWERS WHERE
THERE IS SUFFICIENT LOW LEVEL MOISTURE TO TAP INTO STEEP LOW LEVEL
LAPSE RATES...MAINLY MON INTO EARLY MON NIGHT. WILL INTRODUCE SOME
LOW END POPS FOR THIS POSSIBILITY TO NW UPPER MI. WITH THE STEEP LOW
LEVEL LAPSE RATES...WE SHOULD SEE MIXING TO AROUND 800MB ON
MON...AND WITH SW 800-900MB WINDS AOA 40KTS...IT WILL MAKE FOR GUSTY
SFC WINDS. MAY END UP NEEDING A WIND ADVISORY IN SOME
LOCATIONS...BUT TOO EARLY TO SAY WHERE AT THIS POINT AS MODELS DO
VARY IN STRENGTH AND LOCATION OF BEST LOW LEVEL WINDS. COULD ALSO
SEE SOME DOWNSLOPE ENHANCEMENT OF THE WINDS...ESPECIALLY NEAR LAKE
SUPERIOR ON MARQUETTE COUNTY WITH THE SW WINDS.
EVEN THOUGH 850MB TEMPS DROP BY 7C OR MORE FROM SUN NIGHT INTO
MON...SHOULD STILL BE ABLE TO SEE TEMPS WARM INTO THE 40S /EVEN
AROUND 50 OVER THE SCENTRAL CWA/ MON AFTERNOON DUE TO GOOD LOW LEVEL
MIXING MIXING. THESE WARMER TEMPS AND GUSTY WINDS...COMBINED WITH
SUNSHINE /ESPECIALLY OVER THE CENTRAL AND ERN CWA/ AND RAIN SUN
NIGHT...COULD SEE SOME MELTING OF THE SNOWPACK MON. PROBABLY WILL
NOT LOSE TOO MUCH SNOW PACK...BUT SOME REDUCTION IS CERTAINLY
POSSIBLE.
THE FRONTAL ZONE STALLS WELL TO OUR S THROUGH TUE NIGHT AS UPPER
RIDGING BUILDS OVER THE CWA. THE NRN STREAM JET THEN PUSHES THROUGH
THE CWA TUE NIGHT AS THE UPPER TROUGH OVER THE WRN CONUS SHARPENS UP
AND MOVES TO THE INTERMOUNTAIN WEST. NRN AND SRN STREAM INTERACTION
ALONG THE SRN END OF THE TROUGH WILL CAUSE IT TO DEEPEN AND SHARPEN
UP FURTHER AS IT MOVES E FROM HUDSON BAY TO MN TO TX BY 00Z FRI AS
UPPER RIDGING BUILDS E OF THE CWA. BY LATE WED...WITH THE PRESSURE
GRADIENT TIGHTENING...THE NOW PHASED SRN AND NRN JET STREAM ARCING
FROM W TO N OF THE CWA WILLS STRENGTHEN TO AOA 120KTS. THIS LEADS TO
RAPID SFC CYCLOGENESIS ALONG THE FRONTAL ZONE OVER MO. THE 850MB
FRONTAL ZONE WILL MOVE N INTO THE CWA WED...AND WHEN COMBINED WITH
THE FORCING FROM THE RIGHT ENTRANCE REGION OF THE UPPER JET WILL
LEAD TO PRECIP BY WED AFTERNOON. THE EXACT PLACEMENT AND TYPE OF
PRECIP REMAINS IN QUESTION DUE TO MODEL DISAGREEMENT...BUT GENERALLY
EXPECT SNOW OVER THE NW CWA AND RAIN OVER THE SE CWA...AND THIS
PRECIP SHOULD BE RELATIVELY MINOR ACCUMULATION WISE. PRECIP AMOUNTS
THEN BECOME MORE OF A CONCERN WED NIGHT AND THU AS THE SFC LOW MOVES
ACROSS LAKE MI AND LOWER MI LATE WED NIGHT INTO THU. THE 12Z/13 GFS
AND 00Z/13 ECMWF AGREE PRETTY WELL ON BRINGING THE SFC LOW ACROSS
NRN LOWER MI...BUT THE ECMWF IS ABOUT 6 HOURS FASTER THAN THE GFS AND
NOT AS DEEP WITH THE SFC LOW. OVERALL...A MINOR DIFFERENCE THIS FAR
OUT WITH THE VOLATILE NATURE OF THIS TYPE OF SYSTEM. THINK THAT
MODELS ARE NOT SETTLED AND THINGS WILL CHANGE OVER THE NEXT FEW
DAYS...BUT THE GENERAL IDEA SEEMS GOOD. AT THIS POINT...THERMAL
FIELDS ARE SIMILAR BETWEEN THE MODELS...WITH TEMPS COLD ENOUGH FOR
MAINLY SNOW OVER THE NW CWA...AND MAINLY RAIN OVER THE SE CWA...AT
LEAST UNTIL COLD AIR ARRIVES LATE THU INTO THU NIGHT. SIGNIFICANT
PRECIP AMOUNTS WILL BE POSSIBLE AS MODELS SHOW BETWEEN 0.3 INCHES
AND AROUND 1 INCH OF QPF...BUT VARY ON THE EXACT PLACEMENT OF THIS
PRECIP. STILL SOMETHING TO KEEP A CLOSE EYE ON.
BY LATE THU INTO FRI...ADDITIONAL ENERGY ROUNDING THE BASE OF THE
UPPER TROUGH CAUSES THE SFC LOW TO STALL SOME /OR MORE REDEVELOP ON
THE SW SIDE/. THE MAIN IMPACT THIS HAS ON OUR WEATHER IS TO KEEP
BETTER MOISTURE AND A SFC TROUGH STRETCHED BACK ACROSS LAKE SUPERIOR
AS THE UPPER TROUGH AND MUCH COLDER AIR MOVES ACROSS THE CWA. IF
THIS DOES INDEED COME TO REALITY...LAKE EFFECT SNOW WOULD BE THE
RESULT AS 850MB TEMPS FALL TO AROUND -13C AHEAD OF THE UPPER TROUGH.
LES SHOULD THEN CONTINUE INTO AT LEAST PART OF SATURDAY...BUT
CONFIDENCE IN OVERALL PATTERN DECLINES RAPIDLY THROUGH THE DAY SAT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1257 AM EDT SUN APR 14 2013
AT KIWD...EXPECT VFR CONDITIONS TO PREVAIL THRU MID AFTN THOUGH
THERE MIGHT BE A PERIOD OF MVFR CIGS FOR THE NEXT COUPLE OF HRS PER
SATELLITE IMAGERY. AT KCMX/KSAW...MVFR CIGS SHOULD SCATTER OUT LATE
IN THE NIGHT AS LOW-LEVEL FLOW BECOMES MORE DIFFLUENT. VFR
CONDITIONS WILL THEN PREVAIL THRU THE AFTN. VIGOROUS LOW PRES SYSTEM
APPROACHING THE UPPER LAKES LATE TODAY WILL BRING A SHIELD OF PCPN
INTO UPPER MI. COLUMN WILL BE COLD ENOUGH TO SUPPORT SNOW AT THE
ONSET. SNOW SHOULD BEGIN AT KIWD AROUND 21Z AND AT KCMX/KSAW 1-3HRS
LATER. EXPECT A RAPID DROP TO IFR CONDITIONS AS SNOW BEGINS. AS NOSE
OF WARMER AIR ALOFT SURGES N...PCPN WILL LIKELY MIX WITH/CHANGE TO
SLEET/RAIN AT KIWD/KSAW IN THE EVENING. AS WARMING CONTINUES MORE
STRONGLY INTO CNTRL UPPER MI...PCPN WILL CHANGE TO JUST RAIN AT KSAW
BY LATE EVENING. AT KCMX...COLUMN WILL REMAIN COLDER LONGER...AND
ONLY EXPECT SLEET TO MIX WITH THE SNOW BY LATE EVENING. WITH E TO SE
UPSLOPE WINDS AT KCMX/KSAW...CONDITIONS SHOULD FALL TO LIFR IN THE
EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 415 PM EDT SAT APR 13 2013
NW WINDS UP TO 20-25 KTS OVER THE E HALF THIS EVENING WILL BECOME
LIGHT INTO SUN MORNING WITH ARRIVAL/PASSAGE OF HI PRES RIDGE AXIS.
AS THE NEXT LO PRES SYSTEM MOVES FROM THE NORTHERN PLAINS ON SUN
THRU MN SUN NIGHT AND THE PRES GRADIENT TIGHTENS...A STRONGER E WIND
VEERING SE UP TO 30 KTS WILL DEVELOP. OPTED TO ISSUE A GALE WATCH
FOR THE FAR W AND PORTIONS OF THE NCENTRAL AND E FOR LATE SUN/SUN
NIGHT WHERE THE EXPECTED FLOW IS ENHANCED BY TERRAIN INFLUENCES.
AS THE LOW PRESSURE SYSTEM MOVES FROM NORTHERN MN MONDAY MORNING TO
JAMES BY BY TUESDAY MORNING...STRONG SOUTHWEST WINDS MAY GUST TO 35
KNOTS OVER THE WESTERN HALF OF LAKE SUPERIOR MONDAY INTO MONDAY
NIGHT. WINDS THEN DECREASE TUESDAY INTO WEDNESDAY BEFORE INCREASING
OUT OF THE N WEDNESDAY NIGHT INTO FRIDAY WHEN GALES MAY BE POSSIBLE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM THIS EVENING THROUGH LATE TONIGHT FOR LSZ264-266.
GALE WARNING FROM 5 PM EDT /4 PM CDT/ THIS AFTERNOON TO 2 AM EDT
/1 AM CDT/ MONDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...KC/TITUS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
121 AM EDT SUN APR 14 2013
.SYNOPSIS...
UPPER LEVEL LOW PRESSURE OVER THE NORTHERN GREAT LAKES WILL BE THE
DOMINANT WEATHER FEATURE ACROSS THE NORTH COUNTRY THIS WEEKEND AS IT
SHIFTS EASTWARD ACROSS SOUTHERN ONTARIO AND QUEBEC. THE LOW WILL BE
ACCOMPANIED BY SCATTERED RAIN AND SNOW SHOWERS. HIGH PRESSURE AND
DRY CONDITIONS RETURN FOR MONDAY.TEMPERATURES WILL BE A BIT BELOW
NORMAL THROUGH SUNDAY...BUT THEN WARM TO ABOVE SEASONAL LEVELS
MONDAY.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1249 AM EDT SUNDAY...INHERITED FORECAST IN GOOD SHAPE WITH
ONLY AN INCREASE TO POPS AND WX NEEDED TO ACCOUNT FOR MORE
SCATTERED RAIN/SNOW SHOWERS OVERNIGHT AND SUNDAY. PREVIOUS
DISCUSSION FOLLOWS...
VIGOROUS MID-LEVEL VORT MAX EVIDENT ON WV IMAGERY NEAR LAKE
ONTARIO AT 2230Z WILL LIFT NEWD ACROSS OUR FORECAST AREA DURING
THE LATE EVENING HOURS. ASSOCIATED BANDS OF SHOWERS WILL ACCOMPANY
THIS FEATURE...AIDED BY SWLY UPSLOPE FLOW IN THE NRN ADIRONDACKS
WHERE QPF SHOULD BE THE GREATEST (BUT STILL ONLY 0.1-0.2").
FREEZING LEVELS INITIALLY AROUND 2000 FT PER RAP SOUNDINGS...BUT
SHOULD DROP TO NEAR 1000 FT DURING THE PRE-DAWN HOURS.
THUS...LOOKING FOR SCATTERED VALLEY RAIN SHOWERS GOING TO A
RAIN/SNOW SHOWER MIX AFTER MIDNIGHT. ALREADY SEEING -SHSN AT
SARANAC LAKE WHERE THE 23Z TEMP IS 35F. TEMPS SHOULD FALL BELOW
FREEZING ACROSS THE ADIRONDACKS AND N-CENTRAL/NERN VT ALLOWING FOR
A LIGHT SNOW ACCUMULATION OF A DUSTING TO 2" OVERNIGHT...HIGHEST
IN THE NRN ADIRONDACKS WHERE UPSLOPE FLOW WILL LOCALLY AID IN
FREQUENCY OF SNOW SHOWER ACTIVITY. SKIES WILL GENERALLY REMAIN
OVERCAST...THOUGH MODELS INDICATE SOME BINOVC POSSIBLE AROUND
04-06Z ONCE THE VORT MAX PASSES THROUGH. A SECOND UPR WAVE MOVING
IN FROM THE GREAT LAKES FROM 08-12Z SHOULD REESTABLISH OVERCAST
CONDITIONS LATE. GUSTY SW WINDS WILL CONTINUE FOR ANOTHER 1-3
HOURS ACROSS NRN NY (UP TO 30 MPH IN THE ST. LAWRENCE
VALLEY)...BEFORE GRADUALLY SUBSIDING. MIN TEMPS TONIGHT WILL BE
MOSTLY IN THE LOWER TO MID 30S.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH MONDAY NIGHT/...
AS OF 355 PM EDT SATURDAY...AFOREMENTIONED UPPER LEVEL LOW
CONTINUES TO AFFECT THE NORTH COUNTRY SUNDAY AS IT SHIFTS EAST
THROUGH SOUTHERN QUEBEC. SEVERAL MORE PIECES OF SHORTWAVE ENERGY
ROUNDING THE BASE OF THE UPPER TROUGH AS IT DEPARTS WILL KEEP
CHANCES FOR RAIN/SNOW SHOWERS. FLOW TURNS FROM SOUTHWEST TO MORE
WEST AND NORTHWEST DURING SUNDAY...SO BETTER CHANCES FOR
PRECIPITATION WILL BE OVER THE HIGHER TERRAIN AND ACROSS THE
OROGRAPHICALLY FAVORED WESTERN SLOPES. TEMPS REMAIN NEAR NORMAL
WITH HIGHS SUNDAY IN THE MID 40S TO AROUND 50. UPPER TROUGH FINALLY
DEPARTS SUNDAY NIGHT AND UPPER LEVEL RIDGE BUILDS INTO THE
NORTHEAST BY MONDAY. ANY SCATTERED RAIN/SNOW SHOWERS WILL END SUNDAY
EVENING FOLLOWED BY CLEARING. ON MONDAY...EXPECT A MIX OF CLOUDS AND
SUNSHINE AND NOTICEABLY MILDER TEMPERATURES. MEAN 925 TEMPS RISE TO
+5-10C SUPPORTING HIGHS IN THE UPPER 50S AND LOWER 60S. WINDS WILL
ALSO BE ON THE INCREASE FROM THE SOUTH DURING THE DAY WITH SOME
GUSTS 25-30 MPH LIKELY DURING THE AFTERNOON...ESPECIALLY IN THE
CHAMPLAIN VALLEY. SOUTHERLY FLOW CONTINUES TO INCREASE MONDAY NIGHT
AS SURFACE HIGH MOVES FURTHER EAST AND PRESSURE GRADIENT TIGHTENS IN
ADVANCE OF APPROACHING FRONTAL SYSTEM. EXPECT AN INCREASE IN CLOUDS
WITH A CHANCE OF SHOWERS OVERNIGHT...MAINLY OVER NORTHERN TIER OF
ZONES. NON-DIURNAL TEMPERATURE TRENDS LIKELY ACROSS MUCH OF THE AREA
WHERE LOWS WILL BE MAINLY IN THE 40S...AND NOT MUCH BELOW 50 IN
SAINT LAWRENCE VALLEY. EXCEPTION WILL BE EAST OF THE GREEN WHERE
DECOUPLING EXPECTED...ALLOWING FOR LOWS IN THE 30S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 402 PM EDT SATURDAY...ACTIVE PATTERN DURING THE LONG TERM
WITH WARMER TEMPERATURES AND THREAT OF CONVECTION. GFS AND ECMWF
SHOWING GENERAL AGREEMENT WITH SOME TIMING DIFFERENCES.
HIGH PRESSURE SLIDES FURTHER INTO THE ATLANTIC AS COLD FRONT
PUSHES THROUGH THE NORTH COUNTRY TUESDAY INTO TUESDAY NIGHT.
PLENTY OF SOUTHERLY FLOW AHEAD OF THE FRONT...AT 10-20 KTS...WILL
FILTER IN WARM MOIST AIR. 1000-850MB TEMP LAPSE RATES WILL REACH
8+ C/KM ON TUESDAY...HAVE INCLUDED SLGT CHC TS. AS SFC TEMPS
REACHING LOW 60S IN THE VALLEYS AND MID 50S IN THE HIGH TRRN.
WINDS WILL SHIFT SW-W BEHIND THE FRONT WILL CLOUDS REMAINING OVER
NIGHT...KEEPING MIN TEMPS IN THE M30S-M40S.
GFS PUSHING THE FRONT THROUGH FASTER THAN ECMWF...EDGING IN HIGH
PRESSURE BY WEDNESDAY MORNING. GIVEN PROXIMITY OF UPPER LEVEL
VORTICITY...WILL KEEP CLOUDS OVER THE REGION. 925MB TEMPS OF 7C-
12C ON TUESDAY WILL COOL TO 4C-6C ON WEDNESDAY BEHIND THE FRONT
WITH DISSIPATING THREAT OF PRECIP EARLY WEDNESDAY. MAX TEMPS ON
WEDNESDAY COOLER...IN THE 50S.
OVERNIGHT WEDNESDAY NIGHT...THE COLD FRONT WILL BEGIN TO LIFT
BACK NORTH AS A WARM FRONT WITH ANOTHER LOW PRESSURE SYSTEM
APPROACHING FROM THE MID-WEST. THE RIDGE OF HIGH PRESSURE WILL
PUSH TO THE EAST TOWARDS THE CANADIAN MARITIMES EARLY THURSDAY.
WITH CONTINUED CLOUDS...THREAT OF PRECIP WILL RETURN EARLY
THURSDAY...WITH A RETURN TO SOUTHERLY FLOW REINFORCING WAA. 925MB
TEMPS INCREASING TO 13C-17C...WARMING SFC TEMPS INTO THE M50S-
M60S. THE AFOREMENTIONED SFC LOW WILL TRACK TO OUR EAST...KEEPING
WAA AND SOUTHERLY FLOW OVER THE NORTH COUNTRY THURSDAY NIGHT INTO
FRIDAY BEFORE THE ASSOCIATED COLD FRONT BEGINS TO MOVE INTO THE
NORTH COUNTRY FROM THE WEST...BRINGING INCREASING THREAT FOR TS
AS TEMP LAPSE RATES INCREASE. FRONT WILL CONTINUE TO TRAVERSE
OVER THE REGION FRIDAY NIGHT.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
THROUGH 06Z MONDAY...BKN/OVC VFR/MVFR CONDS EXPECTED THROUGH MUCH
OF THE PERIOD WITH OCCNL IFR AT KSLK TERMINAL. UPPER SHORTWAVE TO
PASS THROUGH THE REGION TODAY WITH SCATTERED TO NUMEROUS RAIN AND
SNOW SHOWER ACTIVITY. ACTIVITY SHOULD WANE FROM SW TO NE THROUGH
THE AFTERNOON HOURS...TAPERING OFF BY THIS EVENING. WINDS LIGHT TO
MODERATE SOUTH TO SOUTHWESTERLY 5 TO 10 KNOTS WITH OCCNL GUSTS TO
14-18 KNOTS.
OUTLOOK 00Z MONDAY THROUGH THURSDAY...
00Z MONDAY THROUGH 12Z TUESDAY...VFR CONDITIONS EXPECTED AS A
RIDGE OF HIGH PRESSURE WILL BE OVER THE REGION. SCT SHOWERS MAY
AFFECT KMSS LATE IN THE PERIOD.
12Z TUESDAY THROUGH 06Z THURSDAY...BKN/OVC VFR/MVFR CONDITIONS
WITH BRIEF IFR POSSIBLE IN RAIN SHOWERS AS A COLD FRONT MOVES
THROUGH THE REGION.
06Z THURSDAY ONWARD...WARM FRONT WILL BRING MORE RAIN SHOWERS TO THE
REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RJS
NEAR TERM...BANACOS/LAHIFF
SHORT TERM...RJS
LONG TERM...KGM
AVIATION...JMG/SISSON
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1250 AM EDT SUN APR 14 2013
.SYNOPSIS...
UPPER LEVEL LOW PRESSURE OVER THE NORTHERN GREAT LAKES WILL BE THE
DOMINANT WEATHER FEATURE ACROSS THE NORTH COUNTRY THIS WEEKEND AS IT
SHIFTS EASTWARD ACROSS SOUTHERN ONTARIO AND QUEBEC. THE LOW WILL BE
ACCOMPANIED BY SCATTERED RAIN AND SNOW SHOWERS. HIGH PRESSURE AND
DRY CONDITIONS RETURN FOR MONDAY.TEMPERATURES WILL BE A BIT BELOW
NORMAL THROUGH SUNDAY...BUT THEN WARM TO ABOVE SEASONAL LEVELS
MONDAY.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1249 AM EDT SUNDAY...INHERITED FORECAST IN GOOD SHAPE WITH
ONLY AN INCREASE TO POPS AND WX NEEDED TO ACCOUNT FOR MORE
SCATTERED RAIN/SNOW SHOWERS OVERNIGHT AND SUNDAY. PREVIOUS
DISCUSSION FOLLOWS...
VIGOROUS MID-LEVEL VORT MAX EVIDENT ON WV IMAGERY NEAR LAKE
ONTARIO AT 2230Z WILL LIFT NEWD ACROSS OUR FORECAST AREA DURING
THE LATE EVENING HOURS. ASSOCIATED BANDS OF SHOWERS WILL ACCOMPANY
THIS FEATURE...AIDED BY SWLY UPSLOPE FLOW IN THE NRN ADIRONDACKS
WHERE QPF SHOULD BE THE GREATEST (BUT STILL ONLY 0.1-0.2").
FREEZING LEVELS INITIALLY AROUND 2000 FT PER RAP SOUNDINGS...BUT
SHOULD DROP TO NEAR 1000 FT DURING THE PRE-DAWN HOURS.
THUS...LOOKING FOR SCATTERED VALLEY RAIN SHOWERS GOING TO A
RAIN/SNOW SHOWER MIX AFTER MIDNIGHT. ALREADY SEEING -SHSN AT
SARANAC LAKE WHERE THE 23Z TEMP IS 35F. TEMPS SHOULD FALL BELOW
FREEZING ACROSS THE ADIRONDACKS AND N-CENTRAL/NERN VT ALLOWING FOR
A LIGHT SNOW ACCUMULATION OF A DUSTING TO 2" OVERNIGHT...HIGHEST
IN THE NRN ADIRONDACKS WHERE UPSLOPE FLOW WILL LOCALLY AID IN
FREQUENCY OF SNOW SHOWER ACTIVITY. SKIES WILL GENERALLY REMAIN
OVERCAST...THOUGH MODELS INDICATE SOME BINOVC POSSIBLE AROUND
04-06Z ONCE THE VORT MAX PASSES THROUGH. A SECOND UPR WAVE MOVING
IN FROM THE GREAT LAKES FROM 08-12Z SHOULD REESTABLISH OVERCAST
CONDITIONS LATE. GUSTY SW WINDS WILL CONTINUE FOR ANOTHER 1-3
HOURS ACROSS NRN NY (UP TO 30 MPH IN THE ST. LAWRENCE
VALLEY)...BEFORE GRADUALLY SUBSIDING. MIN TEMPS TONIGHT WILL BE
MOSTLY IN THE LOWER TO MID 30S.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH MONDAY NIGHT/...
AS OF 355 PM EDT SATURDAY...AFOREMENTIONED UPPER LEVEL LOW
CONTINUES TO AFFECT THE NORTH COUNTRY SUNDAY AS IT SHIFTS EAST
THROUGH SOUTHERN QUEBEC. SEVERAL MORE PIECES OF SHORTWAVE ENERGY
ROUNDING THE BASE OF THE UPPER TROUGH AS IT DEPARTS WILL KEEP
CHANCES FOR RAIN/SNOW SHOWERS. FLOW TURNS FROM SOUTHWEST TO MORE
WEST AND NORTHWEST DURING SUNDAY...SO BETTER CHANCES FOR
PRECIPITATION WILL BE OVER THE HIGHER TERRAIN AND ACROSS THE
OROGRAPHICALLY FAVORED WESTERN SLOPES. TEMPS REMAIN NEAR NORMAL
WITH HIGHS SUNDAY IN THE MID 40S TO AROUND 50. UPPER TROUGH FINALLY
DEPARTS SUNDAY NIGHT AND UPPER LEVEL RIDGE BUILDS INTO THE
NORTHEAST BY MONDAY. ANY SCATTERED RAIN/SNOW SHOWERS WILL END SUNDAY
EVENING FOLLOWED BY CLEARING. ON MONDAY...EXPECT A MIX OF CLOUDS AND
SUNSHINE AND NOTICEABLY MILDER TEMPERATURES. MEAN 925 TEMPS RISE TO
+5-10C SUPPORTING HIGHS IN THE UPPER 50S AND LOWER 60S. WINDS WILL
ALSO BE ON THE INCREASE FROM THE SOUTH DURING THE DAY WITH SOME
GUSTS 25-30 MPH LIKELY DURING THE AFTERNOON...ESPECIALLY IN THE
CHAMPLAIN VALLEY. SOUTHERLY FLOW CONTINUES TO INCREASE MONDAY NIGHT
AS SURFACE HIGH MOVES FURTHER EAST AND PRESSURE GRADIENT TIGHTENS IN
ADVANCE OF APPROACHING FRONTAL SYSTEM. EXPECT AN INCREASE IN CLOUDS
WITH A CHANCE OF SHOWERS OVERNIGHT...MAINLY OVER NORTHERN TIER OF
ZONES. NON-DIURNAL TEMPERATURE TRENDS LIKELY ACROSS MUCH OF THE AREA
WHERE LOWS WILL BE MAINLY IN THE 40S...AND NOT MUCH BELOW 50 IN
SAINT LAWRENCE VALLEY. EXCEPTION WILL BE EAST OF THE GREEN WHERE
DECOUPLING EXPECTED...ALLOWING FOR LOWS IN THE 30S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 402 PM EDT SATURDAY...ACTIVE PATTERN DURING THE LONG TERM
WITH WARMER TEMPERATURES AND THREAT OF CONVECTION. GFS AND ECMWF
SHOWING GENERAL AGREEMENT WITH SOME TIMING DIFFERENCES.
HIGH PRESSURE SLIDES FURTHER INTO THE ATLANTIC AS COLD FRONT
PUSHES THROUGH THE NORTH COUNTRY TUESDAY INTO TUESDAY NIGHT.
PLENTY OF SOUTHERLY FLOW AHEAD OF THE FRONT...AT 10-20 KTS...WILL
FILTER IN WARM MOIST AIR. 1000-850MB TEMP LAPSE RATES WILL REACH
8+ C/KM ON TUESDAY...HAVE INCLUDED SLGT CHC TS. AS SFC TEMPS
REACHING LOW 60S IN THE VALLEYS AND MID 50S IN THE HIGH TRRN.
WINDS WILL SHIFT SW-W BEHIND THE FRONT WILL CLOUDS REMAINING OVER
NIGHT...KEEPING MIN TEMPS IN THE M30S-M40S.
GFS PUSHING THE FRONT THROUGH FASTER THAN ECMWF...EDGING IN HIGH
PRESSURE BY WEDNESDAY MORNING. GIVEN PROXIMITY OF UPPER LEVEL
VORTICITY...WILL KEEP CLOUDS OVER THE REGION. 925MB TEMPS OF 7C-
12C ON TUESDAY WILL COOL TO 4C-6C ON WEDNESDAY BEHIND THE FRONT
WITH DISSIPATING THREAT OF PRECIP EARLY WEDNESDAY. MAX TEMPS ON
WEDNESDAY COOLER...IN THE 50S.
OVERNIGHT WEDNESDAY NIGHT...THE COLD FRONT WILL BEGIN TO LIFT
BACK NORTH AS A WARM FRONT WITH ANOTHER LOW PRESSURE SYSTEM
APPROACHING FROM THE MID-WEST. THE RIDGE OF HIGH PRESSURE WILL
PUSH TO THE EAST TOWARDS THE CANADIAN MARITIMES EARLY THURSDAY.
WITH CONTINUED CLOUDS...THREAT OF PRECIP WILL RETURN EARLY
THURSDAY...WITH A RETURN TO SOUTHERLY FLOW REINFORCING WAA. 925MB
TEMPS INCREASING TO 13C-17C...WARMING SFC TEMPS INTO THE M50S-
M60S. THE AFOREMENTIONED SFC LOW WILL TRACK TO OUR EAST...KEEPING
WAA AND SOUTHERLY FLOW OVER THE NORTH COUNTRY THURSDAY NIGHT INTO
FRIDAY BEFORE THE ASSOCIATED COLD FRONT BEGINS TO MOVE INTO THE
NORTH COUNTRY FROM THE WEST...BRINGING INCREASING THREAT FOR TS
AS TEMP LAPSE RATES INCREASE. FRONT WILL CONTINUE TO TRAVERSE
OVER THE REGION FRIDAY NIGHT.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
THROUGH 00Z MONDAY...TWO PERIODS OF MVFR AND LOCALLY IFR IN
SHOWERS OF RAIN AND SNOW.
THE FIRST IS OCCURRING NOW WITH A MIX OF RAIN AT THE LOWER
ELEVATION AND SNOW HIGHER AS THE FIRST OF TWO UPPER LEVEL TROUGHS
MOVE THROUGH THE REGION.
THE SECOND WILL MOVE THROUGH ROUGHLY 06Z-14Z WITH ANOTHER PERIOD
OF SHOWERY PRECIPITATION. THERE MAY BE MORE SNOW MIXED IN WITH
THAT BATCH AS TEMPERATURES FALL SLIGHTLY OVERNIGHT.
ANY ACCUMULATIONS WILL BE LIGHT WITH LESS THAN HALF AN INCH
EXPECTED.
CONDITIONS WILL IMPROVE TO VFR BY MID SUNDAY MORNING...BUT YET
ANOTHER DISTURBANCE LOOKS TO AFFECT THE NORTH COUNTRY...KEEPING
SKIES BKN-OVC.
W-SW WINDS OF 6-12G20KTS WILL SHIFT MORE WSW-W OVERNIGHT AT 10KTS
OR LESS.
OUTLOOK 18Z SUNDAY THROUGH THURSDAY...
18Z SUNDAY THROUGH 00Z MONDAY...CONTINUED UNSETTLED CONDITIONS
WITH A MIX OF MVFR/VFR LIKELY AS AN UPPER LOW OVER CANADA
PRODUCES SCATTERED RAIN AND SNOW SHOWERS...WITH SNOW SHOWERS
MAINLY OVER THE HIGHER ELEVATIONS OF THE ADIRONDACKS AND GREEN
MOUNTAINS.
00Z MONDAY THROUGH 12Z TUESDAY...VFR CONDITIONS EXPECTED AS A
RIDGE OF HIGH PRESSURE WILL BE OVER THE REGION. SCT SHOWERS MAY
AFFECT KMSS LATE IN THE PERIOD.
12Z TUESDAY THROUGH 06Z THURSDAY...BKN/OVC VFR/MVFR CONDITIONS
WITH BRIEF IFR POSSIBLE IN RAIN SHOWERS AS A COLD FRONT MOVES
THROUGH THE REGION.
06Z THURSDAY ONWARD...WARM FRONT WILL BRING MORE RAIN SHOWERS TO THE
REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RJS
NEAR TERM...BANACOS/LAHIFF
SHORT TERM...RJS
LONG TERM...KGM
AVIATION...KGM/SISSON
AREA FORECAST DISCUSSION
NWS BISMARCK ND
903 PM CDT SAT APR 13 2013
.UPDATE...
ISSUED AT 904 PM CDT SAT APR 13 2013
SURFACE PRESSURE CONTINUES TO DEVELOP OVER NORTHEAST WYOMING IN
RESPONSE TO A DIGGING UPPER LEVEL TROUGH OVER THE NORTHERN
ROCKIES. LATEST WV IMAGERY SHOWS STRONG SHORTWAVE OVER WESTERN
WYOMING WITH INCREASING UPPER LEVEL DIFLUENCE FROM NORTHEAST
WYOMING INTO EASTERN MONTANA AND THE WESTERN DAKOTAS. EVEN A FEW
LIGHTNING STRIKES SHOWING UP OVER NORTHEAST WYOMING. RADAR
RETURNS ON BOWAN RADAR DIMINISHING A BIT OVER SOUTHWEST NORTH
DAKOTA...BUT LAST FEW SCANS ARE STARTING TO INDICATE THE HIGHER
RETURNS OVER SOUTHEAST MONTANA AND NORTHEAST WYOMING. EXPECT THIS
AREA TO CONTINUE TO INCREASE AND LIFT INTO THE SOUTHWEST THROUGH
THE EVENING HOURS. AS FAR AS THE CURRENT FORECAST...MADE SOME
MINOR ADJUSTMENTS TO LOWER TEMPERATURES IN THE FAR NORTHEAST WHERE
COLDER AIR IS FILTERING IN FROM THE NORTHEAST. MAIN ADJUSTMENT WAS
TO SLOW THE ARRIVAL OF PRECIPITATION FROM THE SOUTHWEST THIS
EVENING. 00Z NAM SHOWS PRECIPITATION SPREADING INTO THE
SOUTHWEST...MAINLY SOUTH OF INTERSTATE 94 THROUGH 10 PM CDT...AND
JUST PUSHING INTO DICKINSON AND BISMARCK AROUND 06 UTC. WARMER
TEMPERATURES IN THE FAR WEST MAY STILL ALLOW FOR A MIX EARLY THIS
EVENING BUT 23Z RAP INDICATES TEMPERATURES ALOFT DECREASING
RAPIDLY AFTER 03 UTC...THEREFORE...BY THE TIME SIGNIFICANT
PRECIPITATION ARRIVES...WE SHOULD BE COLD ENOUGH FOR ALL SNOW.
HAVE UPDATED WEATHER GRIDS AND WILL UPDATE WSW SHORTLY.
UPDATE ISSUED AT 655 PM CDT SAT APR 13 2013
MADE A FEW MINOR CHANGES TO TEMPERATURES THIS EVENING...OTHERWISE
NO SIGNIFICANT CHANGES TO THE GOING FORECAST. LATEST WV IMAGERY
SHOWS STRONG SHORTWAVE TRACKING ACROSS EASTERN IDAHO INTO WYOMING
WITH COOLING CLOUD TOPS OVER EASTERN MONTANA AND THE WESTERN
DAKOTAS. EXPECT PRECIPITATION TO DEVELOP IN THE WEST DURING THE
EVENING THEN SPREAD INTO THE SOUTH CENTRAL LATE THIS EVENING OR
SHORTLY AFTER MIDNIGHT. NO CHANGES TO CURRENT WSW...BUT WILL
TAKE A LOOK AND POSSIBLY FRESHEN UP A BIT.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 340 PM CDT SAT APR 13 2013
MAJOR WINTER STORM SET TO IMPACT THE NORTHERN PLAINS
TONIGHT...SUNDAY...SUNDAY NIGHT...AND THROUGH AT LEAST MONDAY
MORNING. MODELS HAVE COME INTO GREAT AGREEMENT FOR QPF AND SNOW
RATIOS ACROSS WEST AND CENTRAL NORTH DAKOTA FOR THIS EVENT...WITH
CONFIDENCE HIGH ON THE CURRENT FORECAST.
CURRENTLY...LONG WAVE UPPER TROUGH/CLOSED MID LEVEL LOW OVER THE
ROCKIES THIS AFTERNOON...WITH LEE SIDE CYCLOGENESIS UNDERWAY OVER
CENTRAL/EASTERN WYOMING. STRONG SOUTHERLY MID LEVEL MOISTURE
ADVECTION DRAWING GULF OF MEXICO MOISTURE NORTH ACROSS THE DAKOTAS
WITH LOW TO MID LEVEL CLOUDS OVER MOST LOCATIONS. WE DID PARTIALLY
CLEAR THIS AFTERNOON WEST ALLOWING FOR TEMPERATURES TO CLIMB INTO
THE MID 40S. MID 20S TO LOW 30S TO THE EAST WHERE CLOUDY SKIES
HAVE PERSISTED SINCE LAST NIGHT.
REGIONAL RADAR SHOWING THE INITIAL PRECIPITATION WITH OUR IMPENDING
STORM STRETCHED OUT ALONG A SFC TROUGH OVER EASTERN MONTANA AND
AHEAD OF THE MID LEVEL LOW. WHILE IT APPEARS WE WILL BE DRY FOR
THIS AFTERNOON...OPTED TO KEEP A CHANCE OF RAIN/SNOW/SLEET WEST
FOR THE LATER PORTIONS OF THIS AFTERNOON AS SOME ECHOS ARE
APPROACHING THE WESTERN ND BORDER.
THE MID LEVEL LOW CROSSES THE ROCKIES THIS EVENING...THEN MOVES
INTO WESTERN SOUTH DAKOTA OVERNIGHT. SURFACE LOW PRESSURE ADVECTS
EAST IN RESPONSE INTO WESTERN SD THIS EVENING...THEN INTO CENTRAL
SD OVERNIGHT...MAINTAINING AN INVERTED TROUGH STRETCHING BACK
NORTHWEST INTO EASTERN MONTANA. WILL START TO SEE PRECIPITATION
DEVELOPMENT IN EARNEST WITH FRONTOGENESIS AND STRONG LIFTING
(OMEGA) IN THE FAVORED DENDRITIC GROWTH ZONE LIFTING SLOWLY NORTH
FROM NORTHERN SD TO ALONG AND SOUTH OF I94 THIS EVENING...TO THEN
SOUTH OF HIGHWAY 2 OVERNIGHT. WE CAN ALREADY SEE THE ONSET OF THIS
NOW WITH LIGHT RADAR ECHOS DEVELOPING NORTH AND EAST OF THE BLACK
HILLS AREA. THE ENTIRE SYSTEM SLOWS DOWN ON SUNDAY WITH THE
MID/UPPER LEVEL LOW BECOMING NEGATIVELY TILTED...CAUSING THE SFC
LOW (DEPICTED BY BOTH THE GFS AND ECMWF) TO TRACK VERY SLOWLY EAST
ACROSS NORTHERN SOUTH DAKOTA...MAINTAINING STRONG DYNAMICS AND
PRECIPITATION ACROSS MUCH OF WEST AND CENTRAL ND THROUGH SUNDAY
AFTERNOON.
SUNDAY NIGHT INTO MONDAY...DO NOT SEE AN END TO PRECIPITATION
THROUGH 12Z MONDAY. SURFACE LOW PRESSURE SLOWLY TRACKS NORTHEAST
INTO NORTH CENTRAL MINNESOTA BY 06-12Z MONDAY MORNING...WITH WRAP
AROUND PRECIPITATION CONTINUING OVER NORTH DAKOTA UNDERNEATH THE
SYSTEMS TROWAL...ESPECIALLY ACROSS THE NORTH. DO EXPECT THINGS TO
WIND DOWN ACROSS THE SOUTH AFTER MIDNIGHT SUNDAY NIGHT AS THE NOSE
OF THE TROWAL MOVES MORE INTO CANADA.
WHILE A MIX OF PRECIPITATION IS CURRENTLY FORECAST WEST LATE
TODAY...AND EARLY THIS EVENING MAINLY SOUTHWEST...TEMPERATURE
PROFILES SUGGEST THE MAIN PRECIP TYPE WITH THIS STORM TO BE ALL
SNOW. GIVEN GREAT MODEL AGREEMENT ON QPF AND GREAT RUN TO RUN
CONSISTENCY...VERY HEAVY SNOWFALL IS EXPECTED. STORM TOTAL QPF
RANGES FROM AROUND 1-1.3 INCHES FROM DICKINSON EAST THROUGH
BISMARCK AND JAMESTOWN...NEAR AN INCH ALONG THE ND/SD BORDER...AND
0.5-0.75 FAR NORTH. THIS USES A BLEND OF THE LAST TWO WPC (WEATHER
PREDICTION CENTER) FORECASTS...AND THE LATEST 12Z GFS/ECMWF. GRANTED
WE SHOULD SEE THE EARLY ONSET OF PRECIPITATION AS A MIX ACROSS THE
SOUTH...ESPECIALLY CONSIDERING TEMPERATURES RIGHT NOW ARE IN THE
40S. HOWEVER...NEAR TERM HR MODELS INDICATE WE QUICKLY COOL THIS
EVENING...WITH LOCATIONS ALONG I94 AND NORTH LIKELY SEEING ALL
SNOW AS I DO NOT EXPECT THE I94 CORRIDOR TO PRECIPITATE UNTIL MID
EVENING ALLOWING THESE AREAS AND NORTH PLENTY OF TIME TO COOL.
ALSO...BY 03Z AT THE LATEST ALL MODELS HAVE THE MAX TEMPERATURE
ALOFT SUBFREEZING...RESULTING IN ALL SNOW AND MAYBE SOME SLEET
ACROSS THE SOUTH.
SNOW RATIOS THROUGHOUT THIS EVENT ARE DEPICTED IN THE RANGE OF
10/15:1. THIS YIELDS A LARGE AREA OF SNOWFALL IN EXCESS OF A FOOT
FOR THE COUNTIES ALONG THE INTERSTATE 94 CORRIDOR NORTH TO JUST
SOUTH OF HIGHWAY 2. EXPECT A HEAVY BAND AROUND 16 INCHES RIGHT IN
THE MIDDLE OF THIS AREA...INCLUDING
HAZEN...STANTON...BISMARCK/MANDAN...STEELE...AND EAST INTO
JAMESTOWN. SNOW AMOUNTS MAY BE MORE IF THE SYSTEM SLOWS DOWN OR IF
MORE MOISTURE FALLS THAN IS EXPECTED. THE REVERSE IS TRUE IF
THINGS TREND DRYER OR BECOME MORE PROGRESSIVE. DO NOT THINK THE
LATER WILL COME TRUE GIVEN THE CURRENT GREAT MODEL AGREEMENT.
AS IF THIS WAS NOT ENOUGH...STRONG WINDS ARE EXPECTED AS
WELL WITH POTENTIAL GUSTS IN EXCESS OF 40 MPH POSSIBLE...AND WILL
LIKELY SEE NEAR BLIZZARD CONDITIONS IN OPEN AREAS IF NOT EVEN
WITHIN CITIES. AN UPGRADE TO A BLIZZARD WARNING IS VERY POSSIBLE
EITHER LATER TONIGHT OR TOMORROW. OPTED TO KEEP THE WINTER STORM
WARNING FOR NOW WITH SOME UNCERTAINTY ON WIND MAGNITUDES TOMORROW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 340 PM CDT SAT APR 13 2013
THE WEEKEND WINTER STORM WILL CONTINUE TO INFLUENCE THE REGION
MONDAY AND TUESDAY WITH LINGERING LIGHT SNOW AND FLURRIES. FOR
THIS FORECAST ISSUANCE POPS WERE INCREASED SLIGHTLY MONDAY AND
TUESDAY AND HIGH AND LOW TEMPERATURES WERE SLIGHTLY DECREASED.
LATEST 12 AND 18 UTC RUNS OF THE NAM...GFS...EURO SUGGEST THE
SURFACE LOW REMAINS NEARBY MONDAY AND AT LEAST THE NORTHERN
PORTION OF THE STATE WILL BE UNDER THE INFLUENCE LOW/MID LEVEL
CONVERGENCE AND UPPER LEVEL DIFFLUENCE THROUGH TUESDAY. THIS
COMBINED WITH REMAINING WRAPAROUND MOISTURE FROM THE DEPARTING LOW
SHOULD BE ENOUGH TO KEEP SOME LIGHT SNOW OR FLURRIES GOING THROUGH
TUESDAY EVENING. WITH CONTINUED COLDER ADVECTION AND AN EXPANDING
SNOWPACK...NEW GUIDANCE COMES IN SLIGHTLY COOLER THAN PREVIOUSLY
FORECAST. THEREFORE...ADJUSTED MAX/MIN TEMPS ACCORDINGLY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 904 PM CDT SAT APR 13 2013
AREAS OF MVFR CONDITIONS STILL AT KMOT...KJMS AND KBIS. VFR AT
KISN AND KDIK. EXPECT CEILINGS TO LOWER AT KISN AND KDIK THROUGH
THE EARLY EVENING. A MAJOR LATE SEASON STORM WILL BEGIN TO IMPACT
KISN/KDIK NEAR 03-05Z THIS EVENING...INITIALLY A WINTRY
MIX...THEN BECOMING ALL SNOW BY LATE EVENING. PRECIPITATION SHOULD
REACH KBIS-KJMS BY 06Z AND KMOT BY 09-12Z IN THE FORM OF ALL SNOW.
MVFR/IFR AND LOWER CONDITIONS ALL TERMINALS SUNDAY AND SUNDAY
NIGHT WITH PERIODS OF HEAVY SNOW AND BLOWING SNOW AND LOW CIGS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 7 AM CDT /6 AM MDT/ MONDAY FOR NDZ001-
009>011-017>023-025-031>037-040>048-050-051.
WINTER STORM WARNING FROM 7 AM SUNDAY TO 1 PM CDT MONDAY FOR
NDZ002>005-012-013.
&&
$$
UPDATE...TWH
SHORT TERM...NH
LONG TERM...AJ
AVIATION...TWH
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1107 PM MDT SAT APR 13 2013
.UPDATE...
ISSUED AT 640 PM MDT SAT APR 13 2013
00Z SURFACE MAP PLACES LOW NEAR KGCC. SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS MOVING ACROSS NORTHEAST WYOMING INTO
WESTERN SOUTH DAKOTA. SURFACE LOW TRACKS ACROSS THE BLACK HILLS
AROUND 06Z...AND THEN INTO CENTRAL SOUTH DAKOTA BY 12Z. 18Z
NAM/21Z RAP SHOW STRONG SURFACE PRESSURE FALL/RISE COUPLET MOVING
ACROSS THE BLACK HILLS OVERNIGHT. NAM HAS AREA OF 50KT BOUNDARY
LAYER WINDS ALONG EASTERN SIDE OF THE BLACK HILLS AROUND
09Z...WHILE RAP HAS 40-45KT BOUNDARY LAYER WINDS. NAM/RAP
SOUNDINGS PLACE 50KT WINDS FROM 2000-4000FT AGL AND STEEP LOW
LEVEL LAPSE RATES. AS BEST PRESSURE RISES MOVE THROUGH IN THE WAKE
OF THE LOW...THERE SHOULD BE AN HOUR OR TWO OF WIND GUSTS AROUND
45KT. MAY EVEN SEE PEAK WIND GUST FOR RAPID CITY AROUND 50KTS.
WINDS SHOULD SUBSIDE FOR A WHILE BEFORE PICKING UP AGAIN SUNDAY
MORNING. WILL MOVE UP THE START TIME OF THE WIND ADVISORY TO
ACCOUNT FOR THE STRONGER WINDS IN THE WAKE OF THE LOW. NO CHANGES
EXPECTED AT THIS TIME FOR THE WINTER WEATHER ADVISORY ACROSS FAR
NORTHWEST SOUTH DAKOTA.
&&
.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 335 PM MDT SAT APR 13 2013
CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE MOVING
SLOWLY EAST ACROSS NORTH CENTRAL MT...WITH WARM FRONT STRETCHING
SOUTHEASTWARD INTO EASTERN WY. COLD FRONT EXTENDS BACK TO THE
SOUTHWEST OF THE LOW ACROSS WESTERN WY. UPPER LEVEL ANALYSIS HAS LOW
OVER NORTHERN GREAT LAKES REGION...WEAK RIDGING OVER THE NORTHERN
PLAINS...AND THE NEXT SYSTEM MOVING EAST-SOUTHEAST ACROSS WESTERN
MT. SKIES ARE NOW MOSTLY CLOUDY ACROSS THE AREA. THERE ARE A WIDE
RANGE OF TEMPS ACROSS THE AREA...WITH MOSTLY UPPER 30S AND LOWER 40S
TO THE EAST AND SOUTHEAST OF THE BLACK HILLS...40S AND 50S ACROSS
MUCH OF NORTHEASTERN WY...THE BLACK HILLS...AND FAR NORTHWESTERN SD.
WINDS ARE SOUTH-SOUTHWEST ACROSS NORTHEASTERN WY AND THE BLACK
HILLS... EAST-SOUTHEAST AND BREEZY TO THE NORTH AND EAST OF THE
BLACK HILLS.
APPROACHING STORM SYSTEM IS THE MAIN FOCUS OF THE SHORT TERM
PERIOD...AS IT TRACKS EAST-SOUTHEAST ACROSS MT AND THE NORTHERN
PLAINS. 12Z MODELS ARE IN BETTER AGREEMENT THAN PREVIOUS RUNS...BUT
STILL SOME MINOR TIMING AND TRACK DIFFERENCES WHICH WOULD AFFECT
NORTHERN PORTIONS OF THE CWA...ESPECIALLY NORTHWESTERN SD. LOOKING
AT THE VARIOUS MODELS 700 MB LOW TRACKS...THE GFS IS FURTHEST
SOUTH AND QUICKEST...MOVING THE DEVELOPING LOW ACROSS THE NORTHERN
BLACK HILLS AND EAST INTO CENTRAL SD SUNDAY MORNING. THE UKMET IS
SLIGHTLY FURTHER NORTH...WHILE THE NAM...ECMWF...AND SREF TRACK IT
ACROSS FAR SOUTHEASTERN MT LATE TONIGHT AND ALONG THE ND/SD LINE ON
SUNDAY. WITH THE HEAVIEST PCPN TYPICALLY FALLING JUST TO THE NORTH
OF THE 700 MB LOW...THESE SOLUTIONS WOULD GENERALLY FAVOR THE
HEAVIEST SNOWFALL ACROSS FAR NORTHWESTERN SD AND ESPECIALLY PORTIONS
OF NORTHEASTERN MT THROUGH MUCH OF ND. THIS LEAVES CURRENT FORECAST
IN PRETTY GOOD SHAPE...WITH FAR NORTHWESTERN SD LIKELY SEEING THE
HEAVIEST SNOWFALL...GENERALLY 3 TO 6 INCHES... OVERNIGHT INTO
SUNDAY. OBVIOUSLY ANY DEVIATION TO THE EXPECTED TRACK WILL AFFECT
PCPN AND SNOWFALL AMOUNTS ACROSS NORTHWESTERN SD AND POSSIBLY FAR
NORTHEASTERN WY.
WILL KEEP WINTER WX HEADLINES AS IS...WITH AN ADVISORY FOR 3 TO 6
INCHES OF SNOW ACROSS HARDING AND PERKINS COUNTIES. HIGHEST AMOUNTS
LIKELY NEAR THE ND BORDER...WITH LOCALLY HIGHER AMOUNTS NOT OUT OF
THE QUESTION. FURTHER SOUTH...UP TO 3 INCHES OR SO IS POSSIBLE AFTER
RAIN CHANGES TO SNOW ACROSS FAR NORTHERN CAMPBELL CO...CROOK
COUNTY...AND INTO BUTTE COUNTY. THE NORTHERN BLACK HILLS AREA WILL
LIKELY SEE SOME UPSLOPE ENHANCED SNOWFALL SUNDAY AFTER UPPER LOW
PASSES EAST OF THE AREA. UP TO 4 INCHES ARE IN THE FORECAST...
HIGHEST OVER THE HIGHER ELEVATIONS AND FAVORED UPSLOPE AREAS. THIS
COULD CHANGE A BIT AS WELL IF THE LOW MOVES A BIT FURTHER NORTH OR
SOUTH OF THE FORECAST TRACK. EVEN FURTHER SOUTH...THE BEST CHANCE
FOR PCPN ACROSS SOUTHERN SD WILL GENERALLY BE TONIGHT WITH THE COLD
FRONT PASSAGE. LITTLE OR NO SNOWFALL IS EXPECTED IN THESE AREAS.
HIGHS ON SUNDAY WILL RANGE FROM THE LOWER 30S ACROSS THE BLACK HILLS
AND FAR NORTHWESTERN SD...TO THE MID 40S OVER FAR SOUTHERN SD.
THE OTHER ISSUE WILL BE GUSTY WINDS ON SUNDAY AFTER FRONT PASSES AND
PRESSURE GRADIENT TIGHTENS. COLD AIR ADVECTION IS RELATIVELY
WEAK...BUT SUFFICIENT TO MIX STRONGER WINDS ALOFT DOWN DURING THE
LATE MORNING AND AFTERNOON HOURS. WILL ISSUE A WIND ADVISORY FOR A
GOOD PORTION OF THE NORTHWEST AND WEST CENTRAL SD PLAINS FOR LATE
SUNDAY MORNING AND AFTERNOON...WHEN WIND GUSTS OF 45 TO 50 MPH ARE
EXPECTED. THE ADVISORY MAY NEED TO BE EXTENDED FURTHER SOUTH AND
EAST INTO SOUTH CENTRAL SD...BUT NOT SURE IF THE WINDS WILL BE QUITE
THAT STRONG RIGHT NOW. WILL LET OVERNIGHT SHIFT HAVE ANOTHER LOOK AT
IT.
THE SYSTEM WILL MOVE OFF TO THE EAST BY SUNDAY EVENING...WITH PCPN
COVERAGE AND WINDS DIMINISHING.
&&
.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 335 PM MDT SAT APR 13 2013
A LONG WAVE TROUGH WILL VERY SLOWLY CROSS THE CENTRAL
CONUS THROUGH NEXT WEEKEND...KEEPING UNSETTLED AND RATHER COOL
CONDITIONS ACROSS THE REGION. A RATHER SIGNIFICANT SHORTWAVE WILL
MOVE FROM THE CNTRL ROCKIES INTO THE CNTRL PLAINS IN THE TUE-WED
TIME FRAME. THIS WILL BRING A GOOD CHANCE OF LIGHT SNOW TO THE
AREA...ESPECIALLY SOUTH OF I-90...ALTHOUGH THE MODELS KEEP THE MORE
SIGNIFICANT PCPN TO OUR SOUTH. A NRN STREAM CLIPPER WILL THEN CROSS
THE NRN PLAINS ON FRI/FRI NIGHT BRINGING ANOTHER CHANCE OF PCPN AND
POSSIBLE UPSLOPE CONDITIONS TO THE NRN BLKHLS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1105 PM MDT SAT APR 13 2013
WIDESPREAD IFR CIGS WILL PERSIST THROUGH SUNDAY MORNING. IFR
VSBY WITH SNOW LIKELY ACROSS PORTIONS OF NORTHEAST WYOMING AND
NORTHWEST SOUTH DAKOTA. GUSTY NORTHWEST WIND WILL DEVELOP ACROSS
WESTERN SOUTH DAKOTA OVERNIGHT AND CONTINUE THROUGH SUNDAY
AFTERNOON. IFR CIGS WILL GRADUALLY BECOME MVFR CIGS SUNDAY
AFTERNOON.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM 3 AM TO 6 PM MDT SUNDAY FOR SDZ012-013-026-
030-031-072-073.
WINTER WEATHER ADVISORY UNTIL 6 PM MDT SUNDAY FOR SDZ001-002.
WY...NONE.
&&
$$
UPDATE...7
SHORT TERM...26
LONG TERM...10
AVIATION...7
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1036 PM CDT SAT APR 13 2013
.UPDATE...
ISSUED AT 902 PM CDT SAT APR 13 2013
PRECIPITATION MOVING BACK INTO THE AREA IN A STRONG WARM AIR
ADVECTION REGIME. RAP AND HRRR SEEM TO HAVE A DECENT HANDLE ON
THINGS. THEY SUGGEST THIS WAA PRECIP WILL CONTINUE IN BANDS THROUGH 12Z.
THEN AS THE UPPER LOW AND PV ANOMALY MOVES EAST..EXPECTING ANOTHER
AREA OF RAIN TO PUSH INTO THE JAMES RIVER VALLEY AND TRACK NORTHEAST
ACROSS THE CWA...IMPACTING MAINLY AREAS NORTH OF INTERSTATE 90
THROUGH THE MORNING. DRY SLOT SHOULD MOVE INTO THE CWA FOR THE
AFTERNOON HOURS.
HAD TO MAKE SOME PRETTY BIG CHANGES TO THE FORECAST WITH THE COLD AIR
HANGING TOUGH...WITH DEWPOINTS IN THE MID TO UPPER 20S AND TEMPERATURES
IN THE LOW 30S. WITH EASTERLY FLOW CONTINUING THROUGH THE NIGHT
ADVECTING IN 20S DEWPOINTS...DO NOT THINK TEMPERATURES CHANGE MUCH
THROUGH THE NIGHT...POSSIBLY DROPPING A DEGREE OR TWO IN THE NORTH.
THUS WENT AHEAD AND ISSUED A WINTER WEATHER ADVISORY FOR AREAS NORTH
OF INTERSTATE 90. INITIALLY PRECIP SHOULD BE LIGHT SNOW FROM HURON TO
SIOUX FALLS AND POINTS EAST INTO SOUTHWEST MINNESOTA. BUT MODELS AND
DUAL POL RADAR DATA SHOW WARM AIR ALOFT QUICKLY OVERSPREADING THE CWA
FROM SOUTHWEST TO NORTHEAST. THIS SHOULD CHANGE PRECIP OVER TO SLEET
AND THEN RAIN OR FREEZING RAIN. MAY SEE UP TO AN INCH OF SNOW AND
SLEET FROM BROOKINGS EAST INTO SOUTHWEST MINNESOTA BEFORE THE
CHANGEOVER. CURRENT THOUGHTS ARE FOR UP TO A QUARTER INCH OF ICE
ACCRETION IN THE ADVISORY AREA. FEELING IS QPF WILL BE LOW ENOUGH TO
PREVENT ICE STORM WARNING CRITERIA FROM BEING MET...BUT WILL HAVE TO
MONITOR CLOSELY. WITH MARGINAL TEMEPRATURES...MAINLY EXPECTING ICE TO
ACCUMULATE ON TREES AND CARS...ALTHOUGH SOME SLICK SPOTS ON ROADWAYS
WILL BE LIKELY. WILL HAVE TO MONITOR THE INTERSTATE 90 CORRIDOR...AS
DEPENDING ON RADAR AND TEMPERATURE TRENDS THEY MAY NEED TO BE ADDED
INTO THE ADVISORY AT SOME POINT...BUT FEELING IS THAT FOR NOW THOSE
AREAS WILL SEE LIGHTER ICE ACCRETION WITH ROADWAYS REMAINING MAINLY
JUST WET. TEMPERATURES WILL SLOWLY RISE ABOVE FREEZING SUNDAY MORNING
FROM SOUTH TO NORTH AS WINDS TURN SOUTHERLY.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 352 PM CDT SAT APR 13 2013
NEXT SHORTWAVE TO AFFECT OUR AREA IS TAKING SHAPE OVER NORTHERN
WYOMING THIS AFTERNOON...AND WILL CONTINUE TO TRACK SLOWLY TO THE
EAST FOR TONIGHT AND TOMORROW. OUT AHEAD OF THIS FEATURE...WILL HAVE
SHOWERS DEVELOP IN OUR WEST THIS EVENING...THEN EXPANDING TO THE
EAST OVERNIGHT IN RESPONSE TO STRONG 850 MB THETA E ADVECTION ACROSS
THE AREA AS AN ELEVATED WARM FRONT LIFTS THROUGH THE REGION. THERMAL
PROFILES WOULD SUGGEST THAT A RAIN/SNOW MIX WILL BE POSSIBLE THROUGH
THE AREA FROM BROOKINGS INTO PORTIONS OF SOUTHWESTERN MINNESOTA
DURING THE EARLY NIGHTTIME HOURS WHEN SUB ZERO C TEMPERATURES WILL
EXIST ALOFT...BUT THEN BECOME PLAIN RAIN LATER IN THE NIGHT AS
THERMAL PROFILES WARM. SURFACE TEMPERATURES ARE RATHER TRICKY FOR
THAT AREA TONIGHT...WITH SOME GUIDANCES SUGGESTING READINGS FALLING
JUST AT OR BELOW FREEZING OVER THAT AREA AT SOME POINT TONIGHT. IF
THIS WERE TO OCCUR THEN FREEZING RAIN WOULD DEFINITELY BE AN
ISSUE...HOWEVER...STAYED ON THE HIGHER SIDE OF GUIDANCE WITH LOWS
JUST ABOVE FREEZING IN LIGHT OF CLOUD COVER AND INCREASING
SOUTHEASTERLY WINDS DURING THE NIGHT AS THE GRADIENT TIGHTENS IN
RESPONSE TO DEEPENING LOW PRESSURE IN OUR WEST. OVERNIGHT LOWS AT
THIS POINT LOOK TO RANGE FROM THE MID 30S NORTHEAST TO THE LOWER 40S
THROUGH THE MISSOURI RIVER CORRIDOR. ALSO INCLUDED ISOLATED THUNDER
IN OUR FAR SOUTH AS WEAK ELEVATED INSTABILITY MOVES THROUGH THAT
AREA OVERNIGHT.
ON SUNDAY...AN INVERTED TROUGH PUSHES ACROSS THE CWA DURING THE DAY
WITH THE BULK OF THE PRECIPITATION LIFTING TO THE NORTH AND EAST AS
A DRY SLOT PULLS INTO THE REGION. ON THE BACKSIDE OF THE INVERTED
TROUGH WINDS WILL TRANSITION TO WESTERLY DURING THE DAY AND BECOME
GUSTY WITH STRONG COLD AIR ADVECTION BEHIND THE SYSTEM. WILL BE A
GENERALLY WARMER DAY WITH WARMING THERMAL PROFILES OUT AHEAD OF THE
FEATURE...WITH HIGHS RUNNING FROM THE MID 40S FAR NORTH TO THE MID
50S OVER NORTHWESTERN IOWA.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 352 PM CDT SAT APR 13 2013
CLOSED UPPER AND SURFACE LOW WHICH IS IMPACTING OUR WEATHER TONIGHT
AND SUNDAY...THEN VERY SLOWLY ACROSS EASTERN ND AND NORTHWEST MN
SUNDAY NIGHT. WESTERLY SURFACE WINDS WILL REMAIN QUITE BRISK
ACROSS OUR ZONES FROM I 90 AND POINTS NORTHWARD...WITH THE SURFACE
FRONT AND OCCLUSION WELL EAST OF OUR AREA. AND BOTH THE GFS AND
NAM STRONGLY HINT AT SOME STRATUS NEAR 900MB OOZING DOWN INTO OUR
NORTHERN ZONES NEAR THE HIGHWAY 14 CORRIDOR. BUT AT THIS POINT LEFT
OUT THE MENTION OF EVEN FLURRIES AS AM CONCERNED ABOUT THE
ABILITY OF THE STRATUS TO HAVE ANY ICE PRODUCTION. OUR GOING LOWS
STILL LOOK GOOD WHICH ARE BELOW NORMAL OF COURSE...DESPITE WINDS
AND CLOUDS IN OUR NORTHERN...WHICH NORMALLY WOULD KEEP LOWS
MODERATED A BIT BUT THERE IS A FAIR AMOUNT OF COLD AIR ADVECTION
COMING DOWN.
FOR THE MID WEEK SYSTEM...CONFIDENCE UNFORTUNATELY IS STILL LOW.
ANOTHER UPPER LOW WHICH DIVES DOWN THE BACKSIDE OF THE UPPER LOW
IN THE NORTHERN PLAINS AND NORTHERN MINNESOTA THROUGH THE
INTERMOUNTAIN WEST. THE PROBLEM IS...THE SECOND LOW IS STILL UP IN
THE GULF ALASKA IN A RATHER DATA POOR ENVIRONMENT. THE ACTUAL
DETERMINISTIC SOLUTIONS BETWEEN THE GFS...ECMWF AND GEM GLOBAL ARE
ACTUALLY FAIRLY CLOSE...AND EVENTUALLY BEGIN TO CUT THIS FORECAST
AREA OFF OF MOISTURE WITH THE NORTHERN STREAM JET SOMETIME
THURSDAY OR THURSDAY NIGHT. BUT BEFOREHAND...THE GFS THROWS UP A
FAIR AMOUNT OF QPF FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT. THE ECMWF IS THE DRIEST SOLUTION WHILE THE GEM GLOBAL IS IN
BETWEEN. SO WE WILL JUST HAVE TO KEEP AN EYE ON THIS. AT THIS TIME...
HIGH CHANCE OR LIKELY POPS ARE STILL WARRANTED FOR THE FORECAST
AREA DURING THOSE PERIODS...BUT AGAIN LARGE QUESTIONS REMAIN
WHETHER THE PRECPITATION PRIMARILY IN THE FORM OF SNOW...WILL BE
MODERATE OR LIGHT. TEMPERATURES WILL BE BELOW NORMAL THROUGH THE
WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1032 PM CDT SAT APR 13 2013
VFR CONDTIONS WILL BECOME MVFR CEILINGS DURING THE NIGHT...WITH
OCCASIONAL IFR CEILINGS DEVELOPING AFTER 10Z. AREAS OF LIGHT
FREEZING RAIN...MIXED WITH SNOW WILL PERSIST THROUGH THE NIGHT
NORTHEAST OF A HON-MWM LINE WITH SCATTERED SHOWERS TO THE
SOUTHWEST. VFR CONDITIONS WILL SPREAD BACK INTO AREAS SOUTH OF I90
DURING THE DAY ON SUNDAY...WHILE MVFR CEILINGS PERSIST TO THE
NORTH.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WINTER WEATHER ADVISORY UNTIL 10 AM CDT SUNDAY FOR SDZ038>040-
053>056.
MN...WINTER WEATHER ADVISORY UNTIL 10 AM CDT SUNDAY FOR MNZ071-072-
080-081-097.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHENARD
SHORT TERM...JM
LONG TERM...MJF
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
938 PM CDT SAT APR 13 2013
.UPDATE...
ISSUED AT 902 PM CDT SAT APR 13 2013
PRECIPITATION MOVING BACK INTO THE AREA IN A STRONG WARM AIR
ADVECTION REGIME. RAP AND HRRR SEEM TO HAVE A DECENT HANDLE ON
THINGS. THEY SUGGEST THIS WAA PRECIP WILL CONTINUE IN BANDS THROUGH 12Z.
THEN AS THE UPPER LOW AND PV ANOMALY MOVES EAST..EXPECTING ANOTHER
AREA OF RAIN TO PUSH INTO THE JAMES RIVER VALLEY AND TRACK NORTHEAST
ACROSS THE CWA...IMPACTING MAINLY AREAS NORTH OF INTERSTATE 90
THROUGH THE MORNING. DRY SLOT SHOULD MOVE INTO THE CWA FOR THE
AFTERNOON HOURS.
HAD TO MAKE SOME PRETTY BIG CHANGES TO THE FORECAST WITH THE COLD AIR
HANGING TOUGH...WITH DEWPOINTS IN THE MID TO UPPER 20S AND TEMPERATURES
IN THE LOW 30S. WITH EASTERLY FLOW CONTINUING THROUGH THE NIGHT
ADVECTING IN 20S DEWPOINTS...DO NOT THINK TEMPERATURES CHANGE MUCH
THROUGH THE NIGHT...POSSIBLY DROPPING A DEGREE OR TWO IN THE NORTH.
THUS WENT AHEAD AND ISSUED A WINTER WEATHER ADVISORY FOR AREAS NORTH
OF INTERSTATE 90. INITIALLY PRECIP SHOULD BE LIGHT SNOW FROM HURON TO
SIOUX FALLS AND POINTS EAST INTO SOUTHWEST MINNESOTA. BUT MODELS AND
DUAL POL RADAR DATA SHOW WARM AIR ALOFT QUICKLY OVERSPREADING THE CWA
FROM SOUTHWEST TO NORTHEAST. THIS SHOULD CHANGE PRECIP OVER TO SLEET
AND THEN RAIN OR FREEZING RAIN. MAY SEE UP TO AN INCH OF SNOW AND
SLEET FROM BROOKINGS EAST INTO SOUTHWEST MINNESOTA BEFORE THE
CHANGEOVER. CURRENT THOUGHTS ARE FOR UP TO A QUARTER INCH OF ICE
ACCRETION IN THE ADVISORY AREA. FEELING IS QPF WILL BE LOW ENOUGH TO
PREVENT ICE STORM WARNING CRITERIA FROM BEING MET...BUT WILL HAVE TO
MONITOR CLOSELY. WITH MARGINAL TEMEPRATURES...MAINLY EXPECTING ICE TO
ACCUMULATE ON TREES AND CARS...ALTHOUGH SOME SLICK SPOTS ON ROADWAYS
WILL BE LIKELY. WILL HAVE TO MONITOR THE INTERSTATE 90 CORRIDOR...AS
DEPENDING ON RADAR AND TEMPERATURE TRENDS THEY MAY NEED TO BE ADDED
INTO THE ADVISORY AT SOME POINT...BUT FEELING IS THAT FOR NOW THOSE
AREAS WILL SEE LIGHTER ICE ACCRETION WITH ROADWAYS REMAINING MAINLY
JUST WET. TEMPERATURES WILL SLOWLY RISE ABOVE FREEZING SUNDAY MORNING
FROM SOUTH TO NORTH AS WINDS TURN SOUTHERLY.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 352 PM CDT SAT APR 13 2013
NEXT SHORTWAVE TO AFFECT OUR AREA IS TAKING SHAPE OVER NORTHERN
WYOMING THIS AFTERNOON...AND WILL CONTINUE TO TRACK SLOWLY TO THE
EAST FOR TONIGHT AND TOMORROW. OUT AHEAD OF THIS FEATURE...WILL HAVE
SHOWERS DEVELOP IN OUR WEST THIS EVENING...THEN EXPANDING TO THE
EAST OVERNIGHT IN RESPONSE TO STRONG 850 MB THETA E ADVECTION ACROSS
THE AREA AS AN ELEVATED WARM FRONT LIFTS THROUGH THE REGION. THERMAL
PROFILES WOULD SUGGEST THAT A RAIN/SNOW MIX WILL BE POSSIBLE THROUGH
THE AREA FROM BROOKINGS INTO PORTIONS OF SOUTHWESTERN MINNESOTA
DURING THE EARLY NIGHTTIME HOURS WHEN SUB ZERO C TEMPERATURES WILL
EXIST ALOFT...BUT THEN BECOME PLAIN RAIN LATER IN THE NIGHT AS
THERMAL PROFILES WARM. SURFACE TEMPERATURES ARE RATHER TRICKY FOR
THAT AREA TONIGHT...WITH SOME GUIDANCES SUGGESTING READINGS FALLING
JUST AT OR BELOW FREEZING OVER THAT AREA AT SOME POINT TONIGHT. IF
THIS WERE TO OCCUR THEN FREEZING RAIN WOULD DEFINITELY BE AN
ISSUE...HOWEVER...STAYED ON THE HIGHER SIDE OF GUIDANCE WITH LOWS
JUST ABOVE FREEZING IN LIGHT OF CLOUD COVER AND INCREASING
SOUTHEASTERLY WINDS DURING THE NIGHT AS THE GRADIENT TIGHTENS IN
RESPONSE TO DEEPENING LOW PRESSURE IN OUR WEST. OVERNIGHT LOWS AT
THIS POINT LOOK TO RANGE FROM THE MID 30S NORTHEAST TO THE LOWER 40S
THROUGH THE MISSOURI RIVER CORRIDOR. ALSO INCLUDED ISOLATED THUNDER
IN OUR FAR SOUTH AS WEAK ELEVATED INSTABILITY MOVES THROUGH THAT
AREA OVERNIGHT.
ON SUNDAY...AN INVERTED TROUGH PUSHES ACROSS THE CWA DURING THE DAY
WITH THE BULK OF THE PRECIPITATION LIFTING TO THE NORTH AND EAST AS
A DRY SLOT PULLS INTO THE REGION. ON THE BACKSIDE OF THE INVERTED
TROUGH WINDS WILL TRANSITION TO WESTERLY DURING THE DAY AND BECOME
GUSTY WITH STRONG COLD AIR ADVECTION BEHIND THE SYSTEM. WILL BE A
GENERALLY WARMER DAY WITH WARMING THERMAL PROFILES OUT AHEAD OF THE
FEATURE...WITH HIGHS RUNNING FROM THE MID 40S FAR NORTH TO THE MID
50S OVER NORTHWESTERN IOWA.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 352 PM CDT SAT APR 13 2013
CLOSED UPPER AND SURFACE LOW WHICH IS IMPACTING OUR WEATHER TONIGHT
AND SUNDAY...THEN VERY SLOWLY ACROSS EASTERN ND AND NORTHWEST MN
SUNDAY NIGHT. WESTERLY SURFACE WINDS WILL REMAIN QUITE BRISK
ACROSS OUR ZONES FROM I 90 AND POINTS NORTHWARD...WITH THE SURFACE
FRONT AND OCCLUSION WELL EAST OF OUR AREA. AND BOTH THE GFS AND
NAM STRONGLY HINT AT SOME STRATUS NEAR 900MB OOZING DOWN INTO OUR
NORTHERN ZONES NEAR THE HIGHWAY 14 CORRIDOR. BUT AT THIS POINT LEFT
OUT THE MENTION OF EVEN FLURRIES AS AM CONCERNED ABOUT THE
ABILITY OF THE STRATUS TO HAVE ANY ICE PRODUCTION. OUR GOING LOWS
STILL LOOK GOOD WHICH ARE BELOW NORMAL OF COURSE...DESPITE WINDS
AND CLOUDS IN OUR NORTHERN...WHICH NORMALLY WOULD KEEP LOWS
MODERATED A BIT BUT THERE IS A FAIR AMOUNT OF COLD AIR ADVECTION
COMING DOWN.
FOR THE MID WEEK SYSTEM...CONFIDENCE UNFORTUNATELY IS STILL LOW.
ANOTHER UPPER LOW WHICH DIVES DOWN THE BACKSIDE OF THE UPPER LOW
IN THE NORTHERN PLAINS AND NORTHERN MINNESOTA THROUGH THE
INTERMOUNTAIN WEST. THE PROBLEM IS...THE SECOND LOW IS STILL UP IN
THE GULF ALASKA IN A RATHER DATA POOR ENVIRONMENT. THE ACTUAL
DETERMINISTIC SOLUTIONS BETWEEN THE GFS...ECMWF AND GEM GLOBAL ARE
ACTUALLY FAIRLY CLOSE...AND EVENTUALLY BEGIN TO CUT THIS FORECAST
AREA OFF OF MOISTURE WITH THE NORTHERN STREAM JET SOMETIME
THURSDAY OR THURSDAY NIGHT. BUT BEFOREHAND...THE GFS THROWS UP A
FAIR AMOUNT OF QPF FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT. THE ECMWF IS THE DRIEST SOLUTION WHILE THE GEM GLOBAL IS IN
BETWEEN. SO WE WILL JUST HAVE TO KEEP AN EYE ON THIS. AT THIS TIME...
HIGH CHANCE OR LIKELY POPS ARE STILL WARRANTED FOR THE FORECAST
AREA DURING THOSE PERIODS...BUT AGAIN LARGE QUESTIONS REMAIN
WHETHER THE PRECPITATION PRIMARILY IN THE FORM OF SNOW...WILL BE
MODERATE OR LIGHT. TEMPERATURES WILL BE BELOW NORMAL THROUGH THE
WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 622 PM CDT SAT APR 13 2013
VFR CONDITIONS WILL GRADUALLY BECOME MVFR DURING THE NIGHT AND
THEN IFR LATE TONIGHT AS RAIN SPREAD NORTHEAST ACROSS THE AREA.
FREEZING RAIN WILL BE POSSIBLE LATER TONIGHT INTO EARLY SUNDAY
MORNING NORTHEAST OF A HON-PQN-MWM LINE. CONDITIONS WILL GRADUALLY
BECOME VFR SOUTH OF I90 AFTER 16Z SUNDAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WINTER WEATHER ADVISORY UNTIL 10 AM CDT SUNDAY FOR SDZ038>040-
053>056.
MN...WINTER WEATHER ADVISORY UNTIL 10 AM CDT SUNDAY FOR MNZ071-072-
080-081-097.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHENARD
SHORT TERM...JM
LONG TERM...MJF
AVIATION...
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1153 PM CDT SAT APR 13 2013
.AVIATION...
LOW LEVEL SOUTHERLY FLOW STILL MAY BE CAPABLE OF PATCHY STRATUS
TOWARDS DAYBREAK NEAR KLBB...THOUGH SIGNALS ARE NOT STRONG IN
LATEST GUIDANCE. RETAINED A TEMPO GROUP WITH SCATTERED 1000 FOOT
LAYER TO INDICATE THAT POSSIBILITY. OTHERWISE...LOW LEVEL FLOW
WILL VEER FAIRLY SHARPLY TO THE WEST BY MID MORNING SUNDAY WITH
SURFACE TROUGH AND DRY-LINE EDGING MAINLY EAST OF THE AREA. MODEST
WESTERLY FLOW ALOFT SHOULD LEAD TO SOLID LOW-END WINDY DAY BOTH
TAF SITES WITH VFR CONDITIONS DOMINATING. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 909 PM CDT SAT APR 13 2013/
UPDATE...
THUNDER CHANCES HAVE ENDED FOR THE EVENING. QUICK UPDATE. RMCQUEEN
PREV DISCUSSION... /ISSUED 736 PM CDT SAT APR 13 2013/
UPDATE...
HIGH-BASED THUNDER CHANCES WILL REMAIN BEST IN THE ZONE FROM JUST
NORTH OF MORTON THROUGH LITTLEFIELD AND OLTON TO KRESS FOR THE
NEXT HOUR OR TWO. WE STILL EXPECT ACTIVITY TO DIMINISH AFTER
SUNSET. UPDATED FOR SLIGHTLY FURTHER EAST EXPANSION OF THUNDER
CHANCES AND FOR BETTER COVERAGE OF GUSTY-WIND PRODUCING THUNDER IN
THE FAVORED ZONE INDICATED ABOVE. RMCQUEEN
AVIATION...
NO SIGNIFICANT CHANGES FROM THE PREVIOUS FORECAST. THUNDER CHANCES
THIS EVENING WILL DRIFT NEAR ENOUGH KLBB TO MENTION CUMULONIMBUS
AS THE LOW CLOUD TYPE...BUT DO NOT EXPECT TO MOVE THROUGH KLBB.
A LOW CLOUD LAYER NEAR IFR/MVFR BOUNDARY IS STILL POSSIBLE NEAR
KLBB BRIEFLY NEAR DAYBREAK ON SUNDAY BEFORE THE DRY WESTERLY
COMPONENT WINDS SET IN. VFR SHOULD CONTINUE AT KCDS THROUGH THE
PERIOD. RMCQUEEN
PREV DISCUSSION... /ISSUED 252 PM CDT SAT APR 13 2013/
SHORT TERM...
WEST TEXAS WILL REMAIN UNDER BROAD CYCLONIC FLOW OVER THE SHORT TERM
AS A STORM SYSTEM DIGS THROUGH THE NORTHWESTERN TIER OF THE NATION
AND EMERGES AND STRENGTHENS OVER THE NORTHERN PLAINS SUNDAY. WITHIN
THIS FLOW...A TROUGH AXIS WAS APPROACHING WEST TEXAS AND WILL PASS
TO THE EAST TONIGHT...THOUGH THE BULK OF THE LARGE-SCALE ASCENT WITH
THIS FEATURE WILL EMERGE WELL TO THE SOUTH OF THE FA. EVEN
SO...NORTHERN AND WESTERN SECTIONS OF THE CWA WILL SEE THE
POSSIBILITY OF ISOLATED CONVECTION LATE THIS AFTERNOON THROUGH EARLY
THIS EVENING. LOW-LEVEL MOISTURE IS RATHER LIMITED...WITH DEWPOINTS
ONLY IN THE 30S TO LOWER 40S ACROSS THE CAPROCK...BUT STEEP
MID-LEVEL LAPSE RATES WERE RESULTING IN AROUND 500 J/KG OF SBCAPE
WHILE CIN WAS WEAKENING AND SHOULD BE MINIMAL BY LATE AFTERNOON.
THESE FACTORS COMBINED WITH WEAK CONVERGENCE WERE ALREADY RESULTING
IN A DEVELOPING CUMULUS FIELD FROM NORTH OF HEREFORD TO WEST OF
CLOVIS AS OF 19Z. THE LATEST TTU-WRF...RAP...NAM AND SEVERAL SREF
MEMBERS SUGGEST THAT ISOLATED TO WIDELY SCATTERED CONVECTION WILL
DEVELOP THROUGH MID TO LATE AFTERNOON AND MOVE EASTWARD. EXPECT ANY
ACTIVITY TO QUICKLY WANE THIS EVENING THOUGH THE LATEST RAP AND HRRR
SUGGEST THE ACTIVITY COULD HANG ON AND PASS ACROSS MUCH OF THE SOUTH
PLAINS THIS EVENING. NOT AS CONVINCED OF THIS AND HAVE MAINTAINED
THE ISOLATED THUNDER MENTION GENERALLY ALONG AND WEST OF A MEMPHIS
TO LEVELLAND LINE. RATHER WEAK INSTABILITY...FORCING AND DEEP LAYER
SHEAR SHOULD LIMIT THE STORM ORGANIZATION AND COVERAGE THOUGH
RELATIVELY DRY SUB-CLOUD LAYER /WITH SFC T/TD SPREADS OF 30 TO 40
DEGREES/ COULD SUPPORT LOCALIZED STRONG WIND GUSTS.
A STRONG LLJ WILL THEN DEVELOP ACROSS THE CENTRAL PLAINS TONIGHT
WITH THE SOUTHERN EXTENT OF IT EXTENDING OVER NORTHWEST TEXAS. THIS
JET WILL DRAW BETTER MOISTURE NORTHWARD...WITH MOISTURE ADVECTION
MAXIMIZED ACROSS THE SOUTHWEST ZONES WHERE LOW CLOUDS AND FOG COULD
DEVELOP. BREEZY AND QUICKLY VEERING WINDS TOWARD MORNING SHOULD
LIMIT THE FOG POTENTIAL AND HAVE NOT INCLUDED IN THE GRIDS ATTM.
THIS FLOW WILL ALSO PROVIDE A MILD NIGHT...WITH LOWS IN THE UPPER
40S AND LOWER 50S COMMON. A DRYLINE WILL TIGHTEN TONIGHT IN EASTERN
NM...BUT THE SFC FLOW WILL QUICKLY VEER WESTERLY EARLY SUNDAY AS THE
NORTHERN STORM SYSTEM SHIFTS EASTWARD AND THIS WILL CAUSE THE
DRYLINE TO RACE EASTWARD ACROSS THE SOUTH PLAINS SUNDAY MORNING AND
CLEAR EAST OF THE FA BY MID-AFTERNOON. GUSTY WESTERLY WINDS
SUSTAINED AT 20-25 MPH WILL BE COMMON AND THIS WILL PROPEL HIGHS
WELL INTO THE 80S...WITH EVEN A FEW LOWER 90S POSSIBLE OFF THE
CAPROCK. THESE WARM...DRY AND GUSTY CONDITIONS WILL ALSO CREATE
ELEVATED TO CRITICAL FIRE WEATHER.
LONG TERM...
MAIN INTEREST CONTINUES TO BE UPPER TROUGH AND FRONTAL PASSAGE MID
WEEK AND MODEL INCONSISTENCIES IN HANDLING BOTH FEATURES. 12Z GFS
CAME IN ABOUT 18-24 HOURS SLOWER THAN ITS 00Z RUN AND IS NOW
SLOWER THAN EITHER THE 00Z OR 12Z RUNS OF THE ECMWF. GOOD
CONSISTENCY IN THE ECMWF WILL MAKE IT THE WINNER TODAY...AND GIVEN
THAT THE PREVIOUS FCST TRENDED TOWARD IT...FEW CHANGES WILL BE
MADE TO THAT PART OF THE FCST. IN GENERAL...COOLING TEMPS
WEDNESDAY...THE MAGNITUDE OF WHICH STILL IN DOUBT GIVEN IMPORTANCE
OF FRONTAL TIMING ON THAT ELEMENT. SMALL PRECIP CHANCES CONTINUE
TO FAVOR THE ROLLING PLAINS WHERE SOME LOW LEVEL MOISTURE MAY BE
IN PLACE.
EARLY WEEK WILL CONTINUE TO EXPECT A WEAK FRONTAL BOUNDARY IN OR
NEAR THE NERN PART OF THE FCST AREA THAT SHOULD RESULT IN SLIGHTLY
COOLER TEMPS THERE. LACK OF LOW LEVEL MOISTURE MONDAY SHOULD LIMIT
POPS WHILE BETTER MOISTURE RETURN TUESDAY MAY HELP FUEL ISOLATED
THUNDER. WEST OF THE BOUNDARY...BREEZY AND WARM WITH POSSIBILITY
OF ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS DEVELOPING.
LATTER PART OF THE WEEK LOOKS FAIR AND COOL IN POST-FRONTAL AIR
MASS AND NWLY FLOW ALOFT.
FIRE WEATHER...
THE SOUTH PLAINS REGION WILL SEE GOOD TO EXCELLENT RH RECOVERIES
TONIGHT AS SOUTHERLY FLOW DRAWS IN IMPROVING AMOUNTS OF MOISTURE.
HOWEVER...THIS MOISTURE WILL BE SHUNTED EASTWARD AS A DRYLINE
QUICKLY ADVANCES FROM EASTERN NM /EARLY SUNDAY MORNING/ INTO
SOUTHWEST OK AND WESTERN NORTH TEXAS BY LATE IN THE DAY. RH VALUES
WILL DROP TO 5 TO 10 PERCENT ACROSS THE FA /BEHIND THE DRYLINE/
WHILE TEMPERATURES CLIMB TO 10 TO 15 DEGREES ABOVE AVERAGE.
ADDITIONALLY...SOUTHWEST TO WESTERLY WINDS WILL BECOME SUSTAINED AT
15-25 MPH BEHIND THE DRYLINE DURING THE AFTERNOON...RESULTING IN A
PERIOD OF ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS. HENCE...HAVE
ISSUED A FIRE WEATHER WATCH FOR THE ENTIRE AREA VALID FROM 17-01Z
SUNDAY. EXPECT THE STRONGEST WINDS TO BE ON THE CAPROCK WHERE
LOW-END CRITICAL CONDITIONS /AT LEAST WITH REGARDS TO THE WINDS/
WILL BE MOST LIKELY TO OCCUR FOR THE REQUIRED 3 HOURS OR MORE. IT IS
LESS CERTAIN THAT SPOTS OFF THE CAPROCK WILL OBTAIN MORE THAN
SPOTTY/BRIEF CRITICAL CONDITIONS...BUT HAVE DECIDED TO INCLUDE IN
THE WATCH AND WILL LET THE OVERNIGHT SHIFT DECIDE IF A FIRE DANGER
STATEMENT MAY BE MORE APPROPRIATE.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 44 81 43 80 48 / 20 0 0 0 0
TULIA 49 84 44 82 47 / 30 0 0 0 0
PLAINVIEW 51 85 44 83 50 / 30 0 0 0 0
LEVELLAND 52 85 47 84 49 / 20 0 0 0 0
LUBBOCK 53 87 48 85 52 / 10 0 0 0 0
DENVER CITY 52 85 51 85 51 / 20 0 0 0 0
BROWNFIELD 52 87 49 85 49 / 10 0 0 0 0
CHILDRESS 52 89 48 81 54 / 10 0 0 0 10
SPUR 51 90 50 89 54 / 10 0 0 0 10
ASPERMONT 54 92 53 93 57 / 10 0 0 0 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR THE FOLLOWING ZONES: TXZ021>044.
&&
$$
99/99/05
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
909 PM CDT SAT APR 13 2013
.UPDATE...
THUNDER CHANCES HAVE ENDED FOR THE EVENING. QUICK UPDATE. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 736 PM CDT SAT APR 13 2013/
UPDATE...
HIGH-BASED THUNDER CHANCES WILL REMAIN BEST IN THE ZONE FROM JUST
NORTH OF MORTON THROUGH LITTLEFIELD AND OLTON TO KRESS FOR THE
NEXT HOUR OR TWO. WE STILL EXPECT ACTIVITY TO DIMINISH AFTER
SUNSET. UPDATED FOR SLIGHTLY FURTHER EAST EXPANSION OF THUNDER
CHANCES AND FOR BETTER COVERAGE OF GUSTY-WIND PRODUCING THUNDER IN
THE FAVORED ZONE INDICATED ABOVE. RMCQUEEN
AVIATION...
NO SIGNIFICANT CHANGES FROM THE PREVIOUS FORECAST. THUNDER CHANCES
THIS EVENING WILL DRIFT NEAR ENOUGH KLBB TO MENTION CUMULONIMBUS
AS THE LOW CLOUD TYPE...BUT DO NOT EXPECT TO MOVE THROUGH KLBB.
A LOW CLOUD LAYER NEAR IFR/MVFR BOUNDARY IS STILL POSSIBLE NEAR
KLBB BRIEFLY NEAR DAYBREAK ON SUNDAY BEFORE THE DRY WESTERLY
COMPONENT WINDS SET IN. VFR SHOULD CONTINUE AT KCDS THROUGH THE
PERIOD. RMCQUEEN
PREV DISCUSSION... /ISSUED 252 PM CDT SAT APR 13 2013/
SHORT TERM...
WEST TEXAS WILL REMAIN UNDER BROAD CYCLONIC FLOW OVER THE SHORT TERM
AS A STORM SYSTEM DIGS THROUGH THE NORTHWESTERN TIER OF THE NATION
AND EMERGES AND STRENGTHENS OVER THE NORTHERN PLAINS SUNDAY. WITHIN
THIS FLOW...A TROUGH AXIS WAS APPROACHING WEST TEXAS AND WILL PASS
TO THE EAST TONIGHT...THOUGH THE BULK OF THE LARGE-SCALE ASCENT WITH
THIS FEATURE WILL EMERGE WELL TO THE SOUTH OF THE FA. EVEN
SO...NORTHERN AND WESTERN SECTIONS OF THE CWA WILL SEE THE
POSSIBILITY OF ISOLATED CONVECTION LATE THIS AFTERNOON THROUGH EARLY
THIS EVENING. LOW-LEVEL MOISTURE IS RATHER LIMITED...WITH DEWPOINTS
ONLY IN THE 30S TO LOWER 40S ACROSS THE CAPROCK...BUT STEEP
MID-LEVEL LAPSE RATES WERE RESULTING IN AROUND 500 J/KG OF SBCAPE
WHILE CIN WAS WEAKENING AND SHOULD BE MINIMAL BY LATE AFTERNOON.
THESE FACTORS COMBINED WITH WEAK CONVERGENCE WERE ALREADY RESULTING
IN A DEVELOPING CUMULUS FIELD FROM NORTH OF HEREFORD TO WEST OF
CLOVIS AS OF 19Z. THE LATEST TTU-WRF...RAP...NAM AND SEVERAL SREF
MEMBERS SUGGEST THAT ISOLATED TO WIDELY SCATTERED CONVECTION WILL
DEVELOP THROUGH MID TO LATE AFTERNOON AND MOVE EASTWARD. EXPECT ANY
ACTIVITY TO QUICKLY WANE THIS EVENING THOUGH THE LATEST RAP AND HRRR
SUGGEST THE ACTIVITY COULD HANG ON AND PASS ACROSS MUCH OF THE SOUTH
PLAINS THIS EVENING. NOT AS CONVINCED OF THIS AND HAVE MAINTAINED
THE ISOLATED THUNDER MENTION GENERALLY ALONG AND WEST OF A MEMPHIS
TO LEVELLAND LINE. RATHER WEAK INSTABILITY...FORCING AND DEEP LAYER
SHEAR SHOULD LIMIT THE STORM ORGANIZATION AND COVERAGE THOUGH
RELATIVELY DRY SUB-CLOUD LAYER /WITH SFC T/TD SPREADS OF 30 TO 40
DEGREES/ COULD SUPPORT LOCALIZED STRONG WIND GUSTS.
A STRONG LLJ WILL THEN DEVELOP ACROSS THE CENTRAL PLAINS TONIGHT
WITH THE SOUTHERN EXTENT OF IT EXTENDING OVER NORTHWEST TEXAS. THIS
JET WILL DRAW BETTER MOISTURE NORTHWARD...WITH MOISTURE ADVECTION
MAXIMIZED ACROSS THE SOUTHWEST ZONES WHERE LOW CLOUDS AND FOG COULD
DEVELOP. BREEZY AND QUICKLY VEERING WINDS TOWARD MORNING SHOULD
LIMIT THE FOG POTENTIAL AND HAVE NOT INCLUDED IN THE GRIDS ATTM.
THIS FLOW WILL ALSO PROVIDE A MILD NIGHT...WITH LOWS IN THE UPPER
40S AND LOWER 50S COMMON. A DRYLINE WILL TIGHTEN TONIGHT IN EASTERN
NM...BUT THE SFC FLOW WILL QUICKLY VEER WESTERLY EARLY SUNDAY AS THE
NORTHERN STORM SYSTEM SHIFTS EASTWARD AND THIS WILL CAUSE THE
DRYLINE TO RACE EASTWARD ACROSS THE SOUTH PLAINS SUNDAY MORNING AND
CLEAR EAST OF THE FA BY MID-AFTERNOON. GUSTY WESTERLY WINDS
SUSTAINED AT 20-25 MPH WILL BE COMMON AND THIS WILL PROPEL HIGHS
WELL INTO THE 80S...WITH EVEN A FEW LOWER 90S POSSIBLE OFF THE
CAPROCK. THESE WARM...DRY AND GUSTY CONDITIONS WILL ALSO CREATE
ELEVATED TO CRITICAL FIRE WEATHER.
LONG TERM...
MAIN INTEREST CONTINUES TO BE UPPER TROUGH AND FRONTAL PASSAGE MID
WEEK AND MODEL INCONSISTENCIES IN HANDLING BOTH FEATURES. 12Z GFS
CAME IN ABOUT 18-24 HOURS SLOWER THAN ITS 00Z RUN AND IS NOW
SLOWER THAN EITHER THE 00Z OR 12Z RUNS OF THE ECMWF. GOOD
CONSISTENCY IN THE ECMWF WILL MAKE IT THE WINNER TODAY...AND GIVEN
THAT THE PREVIOUS FCST TRENDED TOWARD IT...FEW CHANGES WILL BE
MADE TO THAT PART OF THE FCST. IN GENERAL...COOLING TEMPS
WEDNESDAY...THE MAGNITUDE OF WHICH STILL IN DOUBT GIVEN IMPORTANCE
OF FRONTAL TIMING ON THAT ELEMENT. SMALL PRECIP CHANCES CONTINUE
TO FAVOR THE ROLLING PLAINS WHERE SOME LOW LEVEL MOISTURE MAY BE
IN PLACE.
EARLY WEEK WILL CONTINUE TO EXPECT A WEAK FRONTAL BOUNDARY IN OR
NEAR THE NERN PART OF THE FCST AREA THAT SHOULD RESULT IN SLIGHTLY
COOLER TEMPS THERE. LACK OF LOW LEVEL MOISTURE MONDAY SHOULD LIMIT
POPS WHILE BETTER MOISTURE RETURN TUESDAY MAY HELP FUEL ISOLATED
THUNDER. WEST OF THE BOUNDARY...BREEZY AND WARM WITH POSSIBILITY
OF ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS DEVELOPING.
LATTER PART OF THE WEEK LOOKS FAIR AND COOL IN POST-FRONTAL AIR
MASS AND NWLY FLOW ALOFT.
FIRE WEATHER...
THE SOUTH PLAINS REGION WILL SEE GOOD TO EXCELLENT RH RECOVERIES
TONIGHT AS SOUTHERLY FLOW DRAWS IN IMPROVING AMOUNTS OF MOISTURE.
HOWEVER...THIS MOISTURE WILL BE SHUNTED EASTWARD AS A DRYLINE
QUICKLY ADVANCES FROM EASTERN NM /EARLY SUNDAY MORNING/ INTO
SOUTHWEST OK AND WESTERN NORTH TEXAS BY LATE IN THE DAY. RH VALUES
WILL DROP TO 5 TO 10 PERCENT ACROSS THE FA /BEHIND THE DRYLINE/
WHILE TEMPERATURES CLIMB TO 10 TO 15 DEGREES ABOVE AVERAGE.
ADDITIONALLY...SOUTHWEST TO WESTERLY WINDS WILL BECOME SUSTAINED AT
15-25 MPH BEHIND THE DRYLINE DURING THE AFTERNOON...RESULTING IN A
PERIOD OF ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS. HENCE...HAVE
ISSUED A FIRE WEATHER WATCH FOR THE ENTIRE AREA VALID FROM 17-01Z
SUNDAY. EXPECT THE STRONGEST WINDS TO BE ON THE CAPROCK WHERE
LOW-END CRITICAL CONDITIONS /AT LEAST WITH REGARDS TO THE WINDS/
WILL BE MOST LIKELY TO OCCUR FOR THE REQUIRED 3 HOURS OR MORE. IT IS
LESS CERTAIN THAT SPOTS OFF THE CAPROCK WILL OBTAIN MORE THAN
SPOTTY/BRIEF CRITICAL CONDITIONS...BUT HAVE DECIDED TO INCLUDE IN
THE WATCH AND WILL LET THE OVERNIGHT SHIFT DECIDE IF A FIRE DANGER
STATEMENT MAY BE MORE APPROPRIATE.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 44 81 43 80 48 / 20 0 0 0 0
TULIA 49 84 44 82 47 / 30 0 0 0 0
PLAINVIEW 51 85 44 83 50 / 30 0 0 0 0
LEVELLAND 52 85 47 84 49 / 20 0 0 0 0
LUBBOCK 53 87 48 85 52 / 10 0 0 0 0
DENVER CITY 52 85 51 85 51 / 20 0 0 0 0
BROWNFIELD 52 87 49 85 49 / 10 0 0 0 0
CHILDRESS 52 89 48 81 54 / 10 0 0 0 10
SPUR 51 90 50 89 54 / 10 0 0 0 10
ASPERMONT 54 92 53 93 57 / 10 0 0 0 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR THE FOLLOWING ZONES: TXZ021>044.
&&
$$
05/99
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
709 PM CDT SAT APR 13 2013
.DISCUSSION...UPDATE FOR 00Z AVIATION BELOW.
&&
.AVIATION...VFR CONDITIONS THROUGH THE EVENING HOURS ACROSS SOUTH
TEXAS. SE WIND WILL GRADUALLY DIMINISH AFTER SUNSET. MOS GUIDANCE
SPLIT ON AMOUNT OF STRATUS AND CEILING CATEGORIES THAT DEVELOP
OVERNIGHT. DEW POINTS STILL RELATIVELY LOW...BUT DO INCREASE
OVERNIGHT AND FORECAST SOUNDINGS SHOWING SHALLOW MOIST PROFILE
DEVELOPING LATE OVERNIGHT. THEREFORE HAVE SHOWN PREVAILING MVFR
CEILINGS DEVELOPING AFTER GENERALLY AFTER 06Z. COULD ALSO BE
SHALLOW BR DEVELOPING OVERNIGHT AND PERSISTING UNTIL 14Z FROM
ALI-BEA-VCT...PRODUCING IFR-MVFR VISIBILITIES WHERE SURFACE WINDS
DE- COUPLE. VFR CONDITIONS DEVELOPING AFTER 14Z ACROSS SOUTH TEXAS.
&&
.PREV DISCUSSION... /ISSUED 401 PM CDT SAT APR 13 2013/
SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...DESPITE A POTENT UPPER
LEVEL LOW CURRENTLY MVG ACROSS W TX WITH ENERGY ALOFT EXPECTED TO MV
ACROSS S TX TONIGHT...CONFIDENCE IS LOW THAT THE CWA WILL SEE ANY
BENIFICIAL RAIN. THE NAM AND RUC13 SHOW VERY LIGHT PRECIP ACROSS THE
NE CWA AND OVER THE WATERS BY EARLY SUNDAY MORNING. MODELS PROG THE
DEEPER MOISTURE TO BE ALONG THE RIO GRANDE AND EXTREME ERN CWA...BUT
MOISTURE IS VERY LIMITED. CIN VALUES ARE PROGD TO BE VERY HIGH ALONG
WITH LOW CAPE VALUES. MOS GUIDANCE POPS ARE ALL LESS THAN 20 PERCENT
WITH SOME LOCATIONS IN THE SINGLE DIGITS. ALL THE MODELS SHOW SOME
PRECIP EITHER N...S...E OR W OF THE CWA TONIGHT...AND WITH THE UPPER
SYSTEM PROGD TO MOVE ACROSS THE REGION TONIGHT...DID NOT WANT TO
COMPLETELY REMOVE POPS OR MENTION OF PRECIP. LOWERED 20 POPS TO 10
ACROSS THE LAND AREAS AND REMOVED TSRA`S FOR MOST OF THE AREA EXCEPT
THE FAR W WHERE STORMS OFF THE SIERRA MADRE COULD MOVE FAR ENOUGH E
TO REACH THE WRN CWA. RAIN CHCS DECREASE FROM W TO E THROUGH SUNDAY
MORNING AS THE UPPER LOW TRACKS E. PRESSURE GRADIENT ACROSS S TX
WILL RELAX THRU SUNDAY AS THE LOW PRESSURE SYSTEM EXITS THE REGION.
AIRMASS ABV THE SFC WILL BE DRIER ON SUNDAY LEADING TO WARMER TEMPS.
FAIRLY LIGHT WINDS...EXCEPT STRONGER ALONG THE RIO GRANDE...AND A
SHALLOW MOIST LAYER AT THE SFC COULD LEAD TO FOG SUNDAY NIGHT ACROSS
THE EASTERN CWA. FCST SOUNDINGS LOOK CONDUCIVE FOR RADIATIONAL FOG
DVLPMNT...POSSIBLY DENSE. SEA FOG COULD ALSO ADVECT INLAND SUNDAY
NIGHT DUE TO HIGHER DEWPOINTS OVER RELATIVELY COOLER SST.
MARINE...WEAK TO MODERATE EASTERLY FLOW WILL RELAX OVERNIGHT AND
VEER TO THE SE IN RESPONSE TO A LOW PRESSURE SYSTEM MOVE ACROSS THE
REGION AND EXITING TO THE E. ONSHORE FLOW WILL STRENGTHEN SLIGHTLY
SUNDAY NIGHT IN RESPONSE TO ANOTHER LOW PRESSURE SYSTEM DIGGING SWD
ALONG THE WEST COAST. PATCHY SEA FOG WILL BE POSSIBLE SUNDAY NIGHT
DUE TO DEWPOINTS IN THE UPPER 60S TO NEAR 70 MOVING ACROSS
RELATIVELY COOLER SST.
LONG TERM (MONDAY THROUGH SATURDAY NIGHT)...START OF PERIOD BEGINS
WITH ONSHORE FLOW AT THE SURFACE AND MOSTLY ZONAL FLOW ALOFT. MODELS
DEVELOP A DEEP UPPER LEVEL TROUGH/DISTURBANCE OVER THE ROCKIES THAT
WILL MOVE ACROSS THE CENTRAL CONUS AND REGION WEDNESDAY AND
THURSDAY. AHEAD OF THIS DISTURBANCE AND ASSOCIATED COLD FRONT EXPECT
ONSHORE FLOW TO INCREASE...AND SCEC TO SCA CONDITION TO DEVELOP
TUESDAY AFTERNOON THROUGH THURSDAY. PWAT VALUES INCREASE AHEAD OF
APPROACHING DISTURBANCE/SURFACE COLD FRONT TO 1.3 UP TO 1.5.
ANTICIPATE ISOLATED TO SHOWERS AND TSTMS AHEAD COLD FRONT ON
WEDNESDAY NIGHT/THURSDAY MORNING. TIMING DIFFERENCES WITH FROPA
STILL EXIST...WITH THE GFS A LITTLE SLOWER THAN THE ECMWF. EVEN
SO...EXPECT FRONT TO BE MOVING OFFSHORE AOA 18Z THURSDAY...AND
TEMPERATURES TO FALL THROUGH THE AFTERNOON. BEHIND THE FRONT WILL SEE
STRONG WINDS...ESPECIALLY OFFSHORE...AND SCA WILL DEVELOP ACROSS THE
GULF WATERS THURSDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 65 85 69 84 70 / 10 10 10 10 10
VICTORIA 59 83 67 84 69 / 10 10 10 10 10
LAREDO 67 94 71 98 73 / 10 0 10 10 10
ALICE 64 88 68 90 69 / 10 10 10 10 10
ROCKPORT 66 78 69 76 69 / 10 10 10 10 10
COTULLA 62 91 67 96 69 / 10 0 10 10 10
KINGSVILLE 65 88 69 87 70 / 10 10 10 10 10
NAVY CORPUS 68 78 70 77 71 / 10 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
76...AVIATION
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1054 PM CDT SAT APR 13 2013
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SUNDAY
ISSUED AT 306 PM CDT SAT APR 13 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE
SPINNING OVER SOUTHEAST ONTARIO WHILE A WEAK SURFACE RIDGE AXIS
EXTENDS FROM CENTRAL CANADA TO THE GULF COAST. EMBEDDED SHORTWAVE
TROUGH OVER NORTHWEST WISCONSIN AND STEEP LOW LEVEL LAPSE RATES ARE
CONTRIBUTING TO SCT SNOW SHOWERS OVER NORTHERN AND ALSO CENTRAL
WISCONSIN THIS AFTERNOON...THOUGH BETWEEN THESE AREAS OVER
EAST-CENTRAL WISCONSIN HAVE REMAINED DRY FOR MOST OF THE DAY. THESE
SNOW SHOWERS SHOULD CONTINUE THROUGH EARLY THIS EVENING.
MEANWHILE...THE NEXT STORM SYSTEM IS MOVING OVER THE NORTHERN
ROCKIES AND IS DUE TO IMPACT THE REGION TOMORROW. PRECIPITATION AND
IMPACTS FROM THIS SYSTEM ARE THE MAIN FORECAST CONCERNS.
TONIGHT...SHORTWAVE TROUGH MOVING THROUGH NORTHWEST WISCONSIN WILL
EXIT OVER NORTHERN LAKE MICHIGAN DURING THE EVENING. INCREASING
SUBSIDENCE AND NOCTURNAL COOLING BEHIND THE WAVE WILL END SNOW
SHOWER CHANCES...BUT STILL PLENTY OF CLOUD COVER UPSTREAM WITHIN LOW
LEVEL CONVERGENCE. SO WILL START SKY CONDITIONS AS MOSTLY CLOUDY
BEFORE TRANSITIONING TO PARTLY CLOUDY SKIES AS SURFACE RIDGE AXIS
BUILDS INTO THE REGION. THEN AFTER MIDNIGHT...CLOUDS WILL BE ON THE
INCREASE AS AN 850MB WARM FRONT LIFTS NE ACROSS THE MID-MISSISSIPPI
VALLEY. SOUTHWEST WINDS AHEAD OF A DEVELOPING LOW PRESSURE SYSTEM
OVER THE CENTRAL PLAINS WILL ADVECT GULF MOISTURE INTO SOUTHWEST
WISCONSIN BY DAYBREAK. THE INCREASE IN MOISTURE COMBINED WITH
INCREASING FORCING NORTH OF THE WARM FRONT WILL LEAD TO PRECIP
APPROACHING CENTRAL WISCONSIN LATE TONIGHT. PROGGED SOUNDINGS
INDICATE A SNOW/SLEET MIX LOOKS TO BE THE PTYPE AT ARRIVAL. LOW
TEMPS TO OCCUR EARLY OVERNIGHT...BEFORE CLOUDS THICKEN LATE.
SUNDAY...SURFACE LOW PRESSURE WILL MOVE NE ACROSS IOWA AND INTO
SOUTHERN OR CENTRAL MINNESOTA...WHILE THE 850MB WARM FRONT WILL LIFT
NORTH INTO NORTHERN WISCONSIN BY LATE AFTERNOON. 50KTS OF SW FLOW
AT 850MB WILL CAUSE AN FGEN INDUCED BAND OF PRECIPITATION TO LIFT
NORTH OVER THE COURSE OF THE MORNING THROUGH ABOUT MID-AFTERNOON.
ALTHOUGH AIR FROM THE RECEDING HIGH IS NOT AS COLD OR DRY AS THE
EVENT OVER THE PAST WEEK...IT STILL SHOULD BE SUFFICIENTLY COLD FOR
PRECIPITATION TYPE TO BE PREDOMINATELY SNOW AND SLEET FOR THE
MORNING...THOUGH SOME RAIN SHOULD MIX IN WITH THE FROZEN PRECIP BY
LATE MORNING OVER CENTRAL AND EAST-CENTRAL WISCONSIN AS SURFACE
TEMPS WARM. COULD SEE AN INCH OR TWO OF ACCUMULATION OVER CENTRAL
WISCONSIN DURING THE AM HOURS. AS TEMPS WARM FURTHER IN THE
AFTERNOON...PRECIP WILL CHANGE TO ALL RAIN OVER CENTRAL AND
NORTHEAST WISCONSIN...WHILE A MIX OF SNOW/SLEET/RAIN WILL CONTINUE
OVER NORTH-CENTRAL WISCONSIN. NORTH-CENTRAL WISCONSIN COULD ALSO
SEE A COUPLE INCHES OF ACCUMULATION. THOUGH PRECIP RATES COULD BE
BEEFY AT TIMES...AM COUNTING ON DAYTIME HEATING TO SUFFICIENTLY WARM
ROAD TEMPS ENOUGH TO PREVENT WIDESPREAD HAZARDOUS TRAVEL. TEMPS
SHOULD TOP OUT IN THE MID 30S NORTH TO LOW 40S SOUTH.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY
ISSUED AT 306 PM CDT SAT APR 13 2013
UPPER LOW WILL LIFT NORTH ACROSS NORTHERN MINNESOTA SUNDAY NIGHT
AS OCCLUDED SURFACE FRONT MOVES THROUGH AND CAUSES THE RAIN TO
TAPER OFF TO SHOWERS. MONDAY WILL BE BLUSTERY BUT MILD AS 925MB
TEMPERATURES RISE A FEW DEGREES ABOVE FREEZING WITH DECENT MIXING
DESPITE MOSTLY CLOUDY SKIES. WENT A COUPLE OF DEGREES COLDER THAN
MOS GUIDANCE AS THERE WILL STILL BE SNOW ON THE GROUND OVER MUCH
OF THE AREA OR AT LEAST COLD AND WET GROUND. MONDAY NIGHT AND
TUESDAY SHOULD BE MOSTLY DRY AS BIG SURFACE HIGH OVER CANADA TRIES
TO EDGE INTO THE NORTHERN GREAT LAKES. MODELS AGREE THAT A SURFACE
WAVE WILL LIFT NORTH FROM THE SOUTHERN PLAINS TO LOWER MICHIGAN
WEDNESDAY AND WEDNESDAY NIGHT. THE TRACK IS A BIT TOO FAR WEST FOR
SIGNIFICANT SNOW BUT THERE SHOULD BE SOME AT THE START AND END
ESPECIALLY IN THE NORTH. THE SYSTEM IS STILL WAY UPSTREAM SO THAT
COULD CHANGE. MUCH COOLER AIR ARRIVES FRIDAY AND SATURDAY AS THE
SYSTEM GOES BY AND ARCTIC HIGH OVER CENTRAL CANADA MAKES A PUSH
TOWARDS THE SOUTH. SOME INSTABILITY SNOW AND RAIN SHOWERS LIKELY
FRIDAY WITH LAKE ENHANCEMENT IN VILAS COUNTY THURSDAY NIGHT AND
FRIDAY.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1045 PM CDT SAT APR 13 2013
SKIES HAVE CLEARED ACROSS MOST OF THE FCST AREA. THIS MAY LEAD
TO SOME PATCHY IFR FOG OVERNIGHT...ESPECIALLY OVER PARTS OF NORTHERN
WI. A WARM FRONT WILL LIFT QUICKLY TO THE NE BY SUNDAY MORNING...
RESULTING IN LOWERING CIGS...AND PRECIPITATION RETURNING TO THE
TAF SITES DURING THE LATE MORNING TO AROUND MIDDAY. PCPN SHOULD
START OFF AS SNOW OR A SNOW/SLEET MIX...THEN GRADUALLY MIX WITH OR
CHANGE OVER TO RAIN FROM SOUTH TO NORTH DURING THE MID-AFTERNOON
TO EARLY EVG. CIGS/VSBYS SHOULD SETTLE INTO THE IFR CATEGORY ONCE
THE STEADY PCPN ARRIVES. ISOLD TSTMS ARE POSSIBLE IN CENTRAL WI
LATE SUN AFTERNOON...AND OVER A GOOD PART OF C/NE/EC WI DURING THE
EVG. CONFIDENCE IS STILL NOT HIGH ENOUGH TO ADD TO THE TAFS.
WILL CARRY LLWS ON SUNDAY AFTERNOON/EVENING...AS SE-S WINDS
INCREASE TO 40-55 KTS IN THE 1500-2000 FT AGL LAYER. THIS IS
PROBABLY THE MOST SERIOUS LLWS THREAT THAT I HAVE SEEN OVER THE
PAST 6 MONTHS.
&&
.HYDROLOGY...
FLOODING CONCERNS HAVE EASED AS COLDER AIR HAS SLOWED THE ONGOING
SNOWMELT. HOWEVER...ANOTHER SYSTEM IS FORECAST TO AFFECT THE
REGION ON SUNDAY AND SUNDAY NIGHT AND PROBABLY RESUME THE RISK OF
RIVER FLOODING AS MORE PCPN FALLS. WL RE-ISSUE THE ESF DETAILING
THE SITN. FLOODING CONCERNS COULD CONT LATER NEXT WEEK...AS YET
ANOTHER SYSTEM TAKES AIM ON NE WI. THERE ARE STILL QUESTIONS AS TO
THE EVENTUAL TRACK OF THE SFC LOW AND WHETHER THE ASSOCIATED PCPN
FALLS AS RAIN OR SNOW.
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......KIECKBUSCH
HYDROLOGY......MPC
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
911 AM EDT SUN APR 14 2013
.SYNOPSIS...
A TROUGH OF LOW PRESSURE REMAINS IN THE AREA TODAY WITH LOW PRESSURE
TO OUR NORTHWEST AND SOUTHEAST. HIGH PRESSURE BUILDS IN ON MONDAY
BEFORE A COLD FRONT APPROACHES THE REGION ON TUESDAY. THE COLD
FRONT WILL STALL TO OUR SOUTH ON WEDNESDAY...BEFORE RETURNING
NORTH AS A WARM FRONT ON THURSDAY. ANOTHER COLD FRONT WILL SLOWLY
APPROACH THE REGION FRIDAY...BEFORE CROSSING NEW ENGLAND ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
.UPDATE...
SHORT WAVE ROTATING OVER THE AREA IS FUELING SHOWERS ACROSS THE
AREA. HAVE EXTENDED POPS A BIT FARTHER SOUTH OVER THE NEXT FEW
HOURS AS HRRR INDICATES SOME DIURNAL SHOWERS MAY POP UP AS CLOUDS
THIN OUT OVER THE COASTAL PLAIN. STRIPE OF POSITIVE VORTICITY WILL
BE OVERHEAD FOR MUCH OF THE AFTERNOON. SKY COVER WAS ADJUSTED TO
REFLECT BREAKS ALREADY DEVELOPING OVER SOUTHERN NH.
&&
PREVIOUS DISCUSSION...UPR LOW PRES IS MEANDERING ACROSS SRN
CANADA ATTM. WEAK S/WV TROFS WILL CONTINUE TO ROTATE AROUND THE
PERIPHERY THRU THIS AFTERNOON. ONE S/WV HAS PULLED THRU WRN ME IN
THE LAST COUPLE OF HRS...WITH SHRA BRIEFLY COMING TO AN END BEHIND
IT. A SECOND S/WV WILL APPROACH OUT OF NY STATE EARLY THIS MORNING
AND CROSS THRU THE AREA THIS AFTERNOON. POP WILL GRADUALLY BE ON
THE INCREASE IN THE NEXT SEVERAL HRS...HOWEVER PCPN WILL BE FAIRLY
DISORGANIZED SO HAVE NOT GONE HIGHER THAN CHANCE OUTSIDE OF THE
HIGHER TERRAIN.
GRADIENT WILL BE WEAK ACROSS THE AREA AS S/WV PASSES OVERHEAD. AS
SUCH HI RES MODEL GUIDANCE SUGGEST THE DEVELOPMENT OF A SEA BREEZE
TODAY. HAVE COOLED TEMPS A LITTLE NEAR THE IMMEDIATE COASTLINE TO
ACCOUNT FOR THIS. HOWEVER...NWLY FLOW DEVELOPING BEHIND THE S/WV
WILL LIMIT THE INLAND EXTENT OF SEA BREEZE FNT. THIS SHOULD ALLOW
HIGH TEMPS TO CLIMB INTO THE 50S FOR SRN NH AND SWRN ME WITH SOME
PEEKS OF SUN LATE IN THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
GRADUAL CLEARING CONTINUES INTO TONIGHT...WITH LOW TEMPS SLIPPING
DOWN TO NEAR 30 DEG. AS HIGH PRES BUILDS INTO THE AREA...UPSLOPE
SHWRS WILL ALSO WIND DOWN.
AS HIGH PRES SLIDES EWD INTO THE MARITIMES A WARM FNT WILL
APPROACH FROM THE W ON MON. ONSHORE FLOW WILL DOMINATE TO THE N OF
THE FNT...AND TEMPS WILL SUFFER BECAUSE OF IT. COASTAL ME WILL
STRUGGLE TO CLIMB TO 50 DEG WITH LLVL NELY FLOW. GUIDANCE IS IN
EXCELLENT AGREEMENT THAT WARMEST TEMPS WILL BE IN THE CT RIVER
VALLEY...WHERE AN ISOLD 60 DEG READING IS NOT OUT OF THE QUESTION
IF THE ENCROACHING CLOUD DECK REMAINS DIFFUSE ENOUGH. OTHERWISE
FNT WILL GRADUALLY LIFT THRU THE AREA INTO TUE.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
A WARM FRONT WILL SLOWLY APPROACH THE REGION FROM THE WEST MONDAY
NIGHT. AS THE FRONT CROSSES NEW ENGLAND TUESDAY AFTERNOON AND
TUESDAY EVENING...MOST OF THE SHOWER ACTIVITY WILL BE CONFINED TO
THE NORTH AND MOUNTAINS.
FOR THE MOST PART...THE 00Z MODEL SUITE IS NOW PUSHING THE COLD
FRONT WELL SOUTH OF THE REGION WEDNESDAY. THERE IS SOME
DISAGREEMENT IN THE EURO CAMP...AS THE FRONT GETS HUNG UP OVER
SOUTHERN NEW ENGLAND DURING THIS TIME PERIOD.
HAVE OPTED FOR THE DRY SCENARIO ON WEDNESDAY. HOWEVER...THE FRONT
WILL RETREAT NORTHWARD ON THURSDAY...WITH THE GREATEST LIKELIHOOD
OF ANY SHOWER ACTIVITY BEING CONFINED TO THE FAR NORTH.
A SLOW MOVING COLD FRONT WILL APPROACH ON FRIDAY. WINDS WILL BE
VERY GUSTY OUT OF THE SOUTH AS THE GRADIENT INCREASES DURING THE
DAY. WIND OFF THE GULF OF MAINE SHOULD KEEP READINGS IN THE
60S...DESPITE H850 TEMPS AOA +10C OVER SOUTHERN AREAS. READINGS
ALONG THE COAST WILL LIKELY REMAIN IN THE 50S DUE TO THE COOL
ONSHORE FLOW.
&&
.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...LOCAL IFR CONDS IN VALLEY FOG THIS MORNING WILL GIVE
WAY TO VFR CONDS THRU MON. SCT SHRA WILL CROSS THE AREA THIS
MORNING...BUT NO RESTRICTIONS ARE EXPECTED. NW WINDS MAY BRIEFLY
GUST AOA 17 KT THIS AFTERNOON...EXCEPT FOR KPWM AND KRKD WHERE SEA
BREEZE IS EXPECTED TO FORM.
LONG TERM...VFR MONDAY NIGHT...FOLLOWED BY CEILINGS LOWERING TO
MVFR BY TUESDAY INTO WEDNESDAY MORNING AS SHOWERS ARRIVE.
CONDITIONS WILL IMPROVE WEDNESDAY DURING THE DAY TO VFR. THE FRONT
WILL RETURN TO THE NORTH AS A WARM FRONT ON THURSDAY WITH PATCHY
MVFR CONDITIONS EXPECTED.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS WILL REMAIN BLO SCA THRESHOLDS THRU MON.
LONG TERM...WINDS AND SEAS BUILD AGAIN ON TUESDAY TO NEARLY A
GALE AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM.
&&
.FIRE WEATHER...
THE FIRE WEATHER DANGER WILL REMAIN LOW THROUGH MONDAY.SCATTERED
SHOWERS ARE EXPECTED TODAY. IN ADDITION WINDS WILL BE LIGHT AND
MINIMUM RH VALUES ABOVE 35 PERCENT.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
UPDATE...HANES
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
839 AM EDT SUN APR 14 2013
.SYNOPSIS...
ISSUED AT 337 AM EDT SUN APR 14 2013
WARMER AIR MAKING A SURGE TOWARD THE AREA THIS MORNING AND EARLY
AFTERNOON WILL TOUCH OFF SOME PRECIPITATION ACROSS THE AREA. THIS
PRECIPITATION COULD START OFF AS RAIN...SNOW...AND EVEN A SLIGHT
CHANCE OF SLEET. THIS WILL MOVE NORTH OF THE AREA BY THIS EVENING.
WARMER AIR WILL SPREAD ACROSS THE AREA THROUGH THE DAY ON MONDAY.
A COLD FRONT WILL GRADUALLY MOVE THROUGH THE AREA DURING THE DAY ON
MONDAY. THE THREAT FOR SHOWERS WITH A FEW STORMS WILL INCREASE LATER
TONIGHT AND CONTINUE THROUGH MONDAY. OCCASIONAL PERIODS OF RAIN WILL
BE POSSIBLE THEN MID TO LATE WEEK THIS WEEK. WARMER AIR WILL
TEMPORARILY MOVE IN BEFORE COLDER AIR MOVES IN NEXT WEEKEND.
&&
.UPDATE...
ISSUED AT 838 AM EDT SUN APR 14 2013
SINCE IT WAS SNOWING WITH VISIBILITIES UNDER 2 MILES AS I DROVE
FROM GRANDVILLE TO M6 AND US-131 AND HOLLAND HAD 3SM -SN AND SINCE
THIS BAND IS MOVING NORTHEAST WITH THE WARM FRONT AND SINCE THE
LATEST HRRR (10Z) SHOWS THIS BAND DEVELOPING AS IT MOVES NORTH I
UPDATED THE FORECAST GRIDS TO SHOW A BAND PRECIPITATION MOVING
NORTH WITH TIME WITH LIKELY TO CONDITIONAL POPS. I USED THE TOP
DOWN METHOD TO CREATE THE PRECIPITATION TYPES SO WE NOW HAVE SNOW
TO RAIN AND SLEET IN THE GRIDS. BY EARLY AFTERNOON THE SOUTH EDGE
SHOULD BE NEAR ROUTE 10 AND BY THEN IT SHOULD BE ALL RAIN. I DO
NOT SEE ANY SIGNIFICANT ACCUMULATION WITH THIS AS IT WILL BE TO
SHORT LIVED.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 337 AM EDT SUN APR 14 2013
THE MAIN CHALLENGES WITH THE SHORT TERM PORTION OF THE FCST INVOLVE
THE CHC OF PCPN TODAY ALONG WITH P-TYPE...AND THEN PCPN CHCS THE
REMAINDER OF THE PERIOD THROUGH TUE. ONE CHANGE IN THE FCST IS TO
LOWER PCPN CHANCES FOR TUE.
THE CLOUDS THAT WERE ASSOCIATED WITH THE BIG AND PERSISTENT LOW
AFFECTING THE AREA OVER THE PAST FEW DAYS HAVE BROKEN UP OVER THE
PAST COUPLE OF HOURS. THIS IS OCCURRING AS THE UPPER FLOW HAS BECOME
ANTI-CYCLONIC AND SFC RIDGING IS MOVING IN. THE NEXT BATCH OF CLOUDS
HAVE ALREADY STARTED TO MOVE IN ACROSS THE SW CORNER OF THE CWFA.
THE INCOMING CLOUDS ARE ASSOCIATED WITH RETURN FLOW IN THE MID
LEVELS ALREADY SETTING UP TO OUR SW THIS MORNING. JUST NORTH OF THE
DEVELOPING WARM FRONT FROM THE CENTRAL PLAINS TO THE MID MS RIVER
VALLEY IS A NARROW BAND OF SHOWERS AND ISOLATED STORMS. THIS BAND
WILL BE MAKING A RUN AT THE CWFA THIS MORNING. THE BEST LLJ AND
SURGE OF MOISTURE WILL TAKE PLACE WEST OF THE STATE. WE WILL NOT SEE
A WHOLE LOT OF MOISTURE BELOW 5K FEET...WHICH WILL HELP TO EAT AWAY
SOME OF THE PCPN THAT TRIES TO MOVE IN.
P-TYPE IS SOMEWHAT OF AN ISSUE WITH THIS PCPN. FCST SOUNDINGS
INDICATE THAT ALMOST THE ENTIRE CWFA IS COLD ENOUGH FOR SNOW. AS THE
WARM AIR SURGES IN...WE EXPECT TO SEE THE LEADING EDGE OF PCPN
INITIALLY START OUT AS SOME LIGHT SNOW. THERE COULD BE A BRIEF
PERIOD OF SOME SLEET AS FCST SOUNDINGS INDICATE AN ABOVE FREEZING
LAYER AT THE SFC AND ALOFT TRAPPING A COLD LAYER AROUND 2K FEET OR
SO THIS MORNING ACROSS THE SOUTH. THIS DOES NOT EXIST UP NORTH WHERE
THE PCPN WILL ARRIVE AFTER THE ELEVATED FREEZING LAYER MIXES OUT. AS
THE WARMER AIR GETS HERE...PCPN WILL CHANGE OVER TO RAIN BEFORE
ENDING.
WE WILL SEE A BREAK IN THE WEATHER THEN FROM LATE THIS AFTERNOON
UNTIL LATER TONIGHT. AT THAT TIME...WE WILL SEE THE LLJ AXIS MOVE IN
OUT AHEAD OF THE COLD FRONT THAT WILL BE APPROACHING THE AREA LATE.
THE MOISTURE TRANSPORT INTO THE AREA AND FRONT MOVING THROUGH WILL
BE SUFFICIENT FOR SPREADING SHOWERS IN FROM THE WEST THROUGH MON
MORNING. FCST SOUNDINGS INDICATE THAT SUFFICIENT ELEVATED
INSTABILITY WILL EXIST ENOUGH TO JUSTIFY A SLIGHT CHC OF THUNDER.
THE FRONT SHOULD CLEAR THE CWFA TO THE SE MON EVENING. PCPN CHCS
WILL DIMINISH MON NIGHT AS THE FRONT SINKS SOUTH INTO INDIANA AND
OHIO. IT WILL BE STALLING OUT AS IT WILL ALIGN WITH THE UPPER FLOW.
THE TREND IN THE MODELS IS FOR IT TO SINK A LITTLE FURTHER SOUTH
WITH A SLIGHTLY BETTER PUSH FROM THE WAVE MOVING THROUGH ONTARIO.
THIS SHOULD PROVIDE FOR A LITTLE LESS RAINFALL POTENTIAL ON TUE.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 337 AM EDT SUN APR 14 2013
GOOD MODEL CONSENSUS CONTINUES WITH THE 00Z GUIDANCE. MAIN IMPACT IN
THE EXTENDED IS MORE RAIN WHICH COULD CONTINUE SOME FLOODING INTO
NEXT WEEKEND. THE COLD FRONT STALLS ALONG OR JUST SOUTH OF THE
SOUTHERN FORECAST AREA WITH STORMS FIRING UP ALONG IT TUESDAY NIGHT.
THEN IT LIFTS NORTH AS A WARM FRONT WEDNESDAY AS ANOTHER SHORTWAVE
TROUGH APPROACHES. SFC LOW ARRIVES WEDNESDAY NIGHT ALONG WITH
HEAVIER RAIN AND SOME THUNDERSTORMS WITH POSSIBLY ANOTHER INCH OR
TWO OF RAIN BY THURSDAY.
COLDER WEATHER ON THE BACKSIDE OF THE LOW FOR THE END OF THE WEEK
WITH A FEW LEFT OVER RAIN AND SNOW SHOWERS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 838 AM EDT SUN APR 14 2013
I UPDATED THE MKG AND GRR TAFS SHOW SHOW THE BAND OF SNOW TO RAIN
MOVING THROUGH THOSE TAF SITES. LIKELY I WILL HAVE TO INCLUDE LAN
IN THIS PRECIPITATION BAND TOO. ONCE THIS MOVES THROUGH VFR SHOULD
PREVAIL THE REST OF TODAY. IT WILL BECOME WINDY TOO.
&&
.MARINE...
ISSUED AT 337 AM EDT SUN APR 14 2013
WE WILL BE ISSUING A SMALL CRAFT ADVISORY FOR THE ENTIRE NEARSHORE
WITH THIS FCST PACKAGE. STRONGER GRADIENT WILL MOVE IN LATER THIS
AFTERNOON AS THE WARM FRONT MOVES THROUGH THE AREA. THESE WINDS WILL
REMAIN UP UNTIL AND JUST AFTER THE FRONT MOVES THROUGH MON
AFTERNOON. WAVES WILL NOT BE A BIG PROBLEM INITIALLY AS THE WIND
WILL BE OFFSHORE. WINDS WILL EVENTUALLY SHIFT TO THE SOUTH/SOUTHWEST
AND WAVES WILL BUILD SOME AT THAT POINT.
&&
.HYDROLOGY...
ISSUED AT 337 AM EDT SUN APR 14 2013
NUMEROUS RIVER ADVISORIES AND WARNINGS REMAIN IN EFFECT...AND WILL
CONTINUE INTO THIS COMING WEEK. IT APPEARS THAT THE CREST ON THE
GRAND RIVER IS NEAR ADA AND WILL CONTINUE DOWNSTREAM OVER THE NEXT
FEW DAYS.
THE MAIN HYDRO CONCERN IN THE FCST IS THE ADDITIONAL RAINFALL
EXPECTED THIS WEEK AS WE WILL ONCE AGAIN BE AFFECTED BY AN UNSETTLED
AND WET PATTERN. THE AREA COULD BE LOOKING AT ANOTHER COUPLE OF
INCHES OF RAINFALL OVER THE NEXT WEEK WHICH WOULD ONLY EXACERBATE
ANY PROBLEMS THAT WILL REMAIN AS THE RAIN ARRIVES. THE POSITIVE SIDE
TO THIS COMING WEEK IS THAT FCST RAINFALL AMOUNTS IN GENERAL HAVE
DIMINISHED A LITTLE BIT. STILL A BIT OF UNCERTAINTY AS TO EXACTLY
HOW MUCH RAIN WE WILL SEE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 8 PM EDT MONDAY
FOR LMZ844>849.
&&
$$
UPDATE...WDM
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...OSTUNO
AVIATION...WDM
HYDROLOGY...NJJ
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
641 AM EDT SUN APR 14 2013
.SYNOPSIS...
A WARM FRONT WILL PUSH NORTHEAST ACROSS THE REGION TODAY. A COLD
FRONT WILL SLOWLY APPROACH THE WESTERN GREAT LAKES FROM THE WEST
TONIGHT INTO MONDAY. THE FRONT IS THEN FORECAST TO SAG INTO THE
REGION MONDAY NIGHT INTO TUESDAY...EVENTUALLY STALLING OUT NEAR
THE OHIO RIVER BY WEDNESDAY. THE FRONT WILL PROVIDE THE FOCUS FOR
SHOWERS AND THUNDERSTORMS THROUGH MID WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE WILL PUSH OFF TO THE EAST/NORTHEAST TODAY AS A WARM
FRONT LIFTS NORTHEAST THROUGH THE REGION. WAA INDUCED CLOUDS WILL
SPREAD QUICKLY INTO THE AREA THIS MORNING. KILN RADAR WAS SHOWING
SHOWERS MOVING INTO THE WRN CWFA. SHOWERS ARE NOW ENCROACHING THE
CINCY METRO AREA SO HAVE EXPANDED CHANCE POPS TO THE SOUTH OF
PREVIOUS FORECAST. LATEST HRRR PUSHES THESE SHOWERS INTO THE
WHITEWATER/MIAMI VALLEY...WEST CENTRAL AND PARTS OF CENTRAL OHIO
DURING THE MORNING HOURS. HAVE INCLUDED A CHANCE OF SHOWERS HERE
AS WELL. OTHERWISE...SKIES SHOULD BECOME MOSTLY SUNNY BY AFTERNOON
AS SOUTHERLY WINDS INCREASE. TEMPERATURES WILL HAVE A SLOW START
DUE TO COOL OVERNIGHT LOWS AND CLOUDS...BUT WE SHOULD SEE A LATE
WARM PUSH WITH SUNSHINE AND SOUTHERLY WINDS. HIGHS WILL RANGE FROM
THE MID 60S FAR NORTH TO THE LOWER 70S SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
FORECAST AREA WILL BE WEDGED BETWEEN A S/WV MOVING ACRS THE SE
U.S. AND A STORM SYSTEM ACRS THE NORTHERN PLAINS/UPR MS RIVER VLY
TONIGHT. SKIES WILL BE MOSTLY CLEAR EARLY WITH INCREASING CLOUDS
LATE AS MOISTURE BEGINS TO SEEP NORTHWARD INTO THE OHIO VALLEY.
FOR MONDAY...A COLD FRONT WILL SLOWLY APPROACH THE REGION FROM THE
WEST. A MIX OF CLOUDS AND SUN ALONG WITH SOUTHERLY FLOW SHOULD
BOOST TEMPERATURES INTO THE LOWER AND MID 70S. SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH THE FRONT SHOULD HOLD OFF FOR THE
MOST PART ACRS THE FAR NW CWFA...BUT WE SHOULD SEE CHANCES
INCREASE TOWARD MONDAY EVENING. THE FRONT IS EXPECTED TO SAG
SLOWLY INTO THE NRN ZONES MONDAY NIGHT...BRINGING AN INCREASING
THREAT FOR SHOWERS AND STORMS HERE AS A MODEST LOW LEVEL JET AND
FRONTAL CONVERGENCE OCCUR.
FOR THE PERIOD TUESDAY INTO TUESDAY NIGHT...MODELS CONTINUE TO
OFFER DIFFERENT SOLUTIONS IN THE TIMING OF THE FRONT AS IT SINKS
SOUTH TOWARD THE OHIO RIVER. THE TIMING WILL HAVE SIGNIFICANT PCPN
AND TEMPERATURE IMPLICATIONS AS THOSE ON THE COOL SIDE OF THE
BOUNDARY WILL SEE MUCH COOLER TEMPERATURES VERSUS THOSE ON THE
WARM SIDE. WILL KEEP LIKELY POPS GOING ACRS THE NRN ZONES TUESDAY
MORNING AND THEN WILL TAPER POPS TO A CHANCE REGION WIDE AS IT IS
HARD TO DISCERN ANY EMBEDDED IMPULSES ALOFT TO AID FRONTAL
CONVERGENCE FOR SHOWER/STORM ACTIVITY. AGAIN...MODELS SUGGEST THAT
THE FRONT WILL STALL OUT NEAR OR SOUTH OF THE OHIO BY WEDNESDAY
MORNING.
FOR WEDNESDAY INTO WEDNESDAY NIGHT...FRONT SHOULD BEGIN TO LIFT
BACK NORTH AS A WARM FRONT AS A STRONGER S/WV AND ASSOCD MID LVL
TROF EJECT FROM THE FOUR CORNERS REGION INTO THE PLAINS...WHICH
WILL FORCE THE MID LVL FLOW TO BUCKLE ACRS OUR REGION. WILL
CONTINUE WITH THE CHANCE OF SHOWERS AND STORMS.
AS FOR TEMPERATURES FOR THE REMAINDER OF THE PERIOD...HAVE TAKEN
A CONSENSUS OF RAW MODEL VALUES GIVEN THE UNCERTAINTY OF THE
PLACEMENT OF THE FRONT.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AN UPPER LEVEL TROUGH WILL PIVOT INTO THE AREA LATE IN THE WORK
WEEK. THIS WILL HELP DRIVE A STRONG COLD FRONT THROUGH THE REGION
THURSDAY INTO FRIDAY. THIS WILL RESULT IN AN INCREASING CHANCE OF
THUNDERSTORMS FROM THE WEST THURSDAY AFTERNOON INTO THURSDAY
EVENING. AS THE FRONT MOVES THROUGH THURSDAY NIGHT...THUNDERSTORMS
SHOULD TAPER OFF TO SOME SHOWERS. TEMPERATURES THURSDAY NIGHT INTO
FRIDAY WILL BE TRICKY DEPENDING ON THE TIMING OF THE FRONT...BUT
WILL LIKELY END UP WITH A PERIOD OF NON DIURNAL TEMPS DURING THAT
PERIOD AS MUCH COOLER AIR FILTERS IN BEHIND THE FRONT. SOME WRAP
AROUND MOISTURE COULD LEAD TO A FEW SHOWERS THROUGH THE DAY ON
FRIDAY. DRIER AIR WILL PUSH IN FOR FRIDAY NIGHT AND SATURDAY...BUT
TEMPERATURES WILL REMAIN BELOW NORMAL HEADING INTO THE WEEKEND.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH THE TAF PERIOD.
HIGH PRESSURE IS DEPARTING THE REGION TO THE EAST...WITH WINDS
BEGINNING TO SWITCH TO A SOUTHEASTERLY DIRECTION. AT THE SAME
TIME...AN AREA OF STRATOCUMULUS (5000-8000 FEET) HAS OVERSPREAD
MUCH OF INDIANA AND OHIO. SOME LIGHT SHOWERS OR SPRINKLES WILL BE
POSSIBLE AT KDAY OVER THE NEXT FEW HOURS...WITH NO SIGNIFICANT
AVIATION IMPACTS EXPECTED.
BY AFTERNOON...MOST OF THE CLOUDS WILL BE HIGH IN THE
ATMOSPHERE...AND SOUTH-SOUTHEASTERLY WINDS WILL GUST INTO THE 15-20
KNOT RANGE. WINDS WILL SHIFT TO MORE OF A SOUTHERLY DIRECTION ON
SUNDAY NIGHT...AS ADDITIONAL MOISTURE MOVES IN FROM THE SOUTH.
THOUGH CEILINGS WILL EVENTUALLY LOWER TO AROUND 4000-5000 FEET
NEAR THE END OF THE TAF PERIOD...VFR CONDITIONS ARE STILL
EXPECTED.
OUTLOOK...SHOWERS AND THUNDERSTORMS ARE POSSIBLE FROM TUESDAY
THROUGH THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...JGL
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
539 AM EDT SUN APR 14 2013
.SYNOPSIS...
A WARM FRONT WILL PUSH NORTHEAST ACROSS THE REGION TODAY. A COLD
FRONT WILL SLOWLY APPROACH THE WESTERN GREAT LAKES FROM THE WEST
TONIGHT INTO MONDAY. THE FRONT IS THEN FORECAST TO SAG INTO THE
REGION MONDAY NIGHT INTO TUESDAY...EVENTUALLY STALLING OUT NEAR
THE OHIO RIVER BY WEDNESDAY. THE FRONT WILL PROVIDE THE FOCUS FOR
SHOWERS AND THUNDERSTORMS THROUGH MID WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE WILL PUSH OFF TO THE EAST/NORTHEAST TODAY AS A WARM
FRONT LIFTS NORTHEAST THROUGH THE REGION. WAA INDUCED CLOUDS WILL
SPREAD QUICKLY INTO THE AREA THIS MORNING. KILN RADAR WAS SHOWING
SHOWERS MOVING INTO THE WRN CWFA. SHOWERS ARE NOW ENCROACHING THE
CINCY METRO AREA SO HAVE EXPANDED CHANCE POPS TO THE SOUTH OF
PREVIOUS FORECAST. LATEST HRRR PUSHES THESE SHOWERS INTO THE
WHITEWATER/MIAMI VALLEY...WEST CENTRAL AND PARTS OF CENTRAL OHIO
DURING THE MORNING HOURS. HAVE INCLUDED A CHANCE OF SHOWERS HERE
AS WELL. OTHERWISE...SKIES SHOULD BECOME MOSTLY SUNNY BY AFTERNOON
AS SOUTHERLY WINDS INCREASE. TEMPERATURES WILL HAVE A SLOW START
DUE TO COOL OVERNIGHT LOWS AND CLOUDS...BUT WE SHOULD SEE A LATE
WARM PUSH WITH SUNSHINE AND SOUTHERLY WINDS. HIGHS WILL RANGE FROM
THE MID 60S FAR NORTH TO THE LOWER 70S SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
FORECAST AREA WILL BE WEDGED BETWEEN A S/WV MOVING ACRS THE SE
U.S. AND A STORM SYSTEM ACRS THE NORTHERN PLAINS/UPR MS RIVER VLY
TONIGHT. SKIES WILL BE MOSTLY CLEAR EARLY WITH INCREASING CLOUDS
LATE AS MOISTURE BEGINS TO SEEP NORTHWARD INTO THE OHIO VALLEY.
FOR MONDAY...A COLD FRONT WILL SLOWLY APPROACH THE REGION FROM THE
WEST. A MIX OF CLOUDS AND SUN ALONG WITH SOUTHERLY FLOW SHOULD
BOOST TEMPERATURES INTO THE LOWER AND MID 70S. SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH THE FRONT SHOULD HOLD OFF FOR THE
MOST PART ACRS THE FAR NW CWFA...BUT WE SHOULD SEE CHANCES
INCREASE TOWARD MONDAY EVENING. THE FRONT IS EXPECTED TO SAG
SLOWLY INTO THE NRN ZONES MONDAY NIGHT...BRINGING AN INCREASING
THREAT FOR SHOWERS AND STORMS HERE AS A MODEST LOW LEVEL JET AND
FRONTAL CONVERGENCE OCCUR.
FOR THE PERIOD TUESDAY INTO TUESDAY NIGHT...MODELS CONTINUE TO
OFFER DIFFERENT SOLUTIONS IN THE TIMING OF THE FRONT AS IT SINKS
SOUTH TOWARD THE OHIO RIVER. THE TIMING WILL HAVE SIGNIFICANT PCPN
AND TEMPERATURE IMPLICATIONS AS THOSE ON THE COOL SIDE OF THE
BOUNDARY WILL SEE MUCH COOLER TEMPERATURES VERSUS THOSE ON THE
WARM SIDE. WILL KEEP LIKELY POPS GOING ACRS THE NRN ZONES TUESDAY
MORNING AND THEN WILL TAPER POPS TO A CHANCE REGION WIDE AS IT IS
HARD TO DISCERN ANY EMBEDDED IMPULSES ALOFT TO AID FRONTAL
CONVERGENCE FOR SHOWER/STORM ACTIVITY. AGAIN...MODELS SUGGEST THAT
THE FRONT WILL STALL OUT NEAR OR SOUTH OF THE OHIO BY WEDNESDAY
MORNING.
FOR WEDNESDAY INTO WEDNESDAY NIGHT...FRONT SHOULD BEGIN TO LIFT
BACK NORTH AS A WARM FRONT AS A STRONGER S/WV AND ASSOCD MID LVL
TROF EJECT FROM THE FOUR CORNERS REGION INTO THE PLAINS...WHICH
WILL FORCE THE MID LVL FLOW TO BUCKLE ACRS OUR REGION. WILL
CONTINUE WITH THE CHANCE OF SHOWERS AND STORMS.
AS FOR TEMPERATURES FOR THE REMAINDER OF THE PERIOD...HAVE TAKEN
A CONSENSUS OF RAW MODEL VALUES GIVEN THE UNCERTAINTY OF THE
PLACEMENT OF THE FRONT.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AN UPPER LEVEL TROUGH WILL PIVOT INTO THE AREA LATE IN THE WORK
WEEK. THIS WILL HELP DRIVE A STRONG COLD FRONT THROUGH THE REGION
THURSDAY INTO FRIDAY. THIS WILL RESULT IN AN INCREASING CHANCE OF
THUNDERSTORMS FROM THE WEST THURSDAY AFTERNOON INTO THURSDAY
EVENING. AS THE FRONT MOVES THROUGH THURSDAY NIGHT...THUNDERSTORMS
SHOULD TAPER OFF TO SOME SHOWERS. TEMPERATURES THURSDAY NIGHT INTO
FRIDAY WILL BE TRICKY DEPENDING ON THE TIMING OF THE FRONT...BUT
WILL LIKELY END UP WITH A PERIOD OF NON DIURNAL TEMPS DURING THAT
PERIOD AS MUCH COOLER AIR FILTERS IN BEHIND THE FRONT. SOME WRAP
AROUND MOISTURE COULD LEAD TO A FEW SHOWERS THROUGH THE DAY ON
FRIDAY. DRIER AIR WILL PUSH IN FOR FRIDAY NIGHT AND SATURDAY...BUT
TEMPERATURES WILL REMAIN BELOW NORMAL HEADING INTO THE WEEKEND.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL BE THE RULE THROUGH THE TAF PERIOD. HIGH
PRESSURE WILL DEPART THE REGION TO THE EAST OVERNIGHT...ALLOWING
WINDS TO SWITCH TO THE SOUTH-SOUTHEAST DURING THE DAY SUNDAY.
THERE WILL BE MID-CLOUDS OVER THE REGION OVERNIGHT...WITH SOME OF
THEM STAYING IN PLACE INTO THE DAY.
A FEW LIGHT SHOWERS OR SPRINKLES ARE EXPECTED TO DEVELOP OVER
INDIANA DURING THE NEXT FEW HOURS. THESE MAY IMPACT THE DAYTON TAF
SITE NEAR SUNRISE...BUT NO IMPACTS TO AVIATION CONDITIONS ARE EXPECTED.
SUNDAY NIGHT...WINDS WILL SHIFT TO THE SOUTH...AND ADDITIONAL
MOISTURE WILL BEGIN TO WORK INTO THE AREA.
OUTLOOK...SHOWERS AND THUNDERSTORMS ARE POSSIBLE FROM TUESDAY
THROUGH THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...JGL
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
435 AM EDT SUN APR 14 2013
.SYNOPSIS...
A WARM FRONT WILL PUSH NORTHEAST ACROSS THE REGION TODAY. A COLD
FRONT WILL SLOWLY APPROACH THE WESTERN GREAT LAKES FROM THE WEST
TONIGHT INTO MONDAY. THE FRONT IS THEN FORECAST TO SAG INTO THE
REGION MONDAY NIGHT INTO TUESDAY...EVENTUALLY STALLING OUT NEAR
THE OHIO RIVER BY WEDNESDAY. THE FRONT WILL PROVIDE THE FOCUS FOR
SHOWERS AND THUNDERSTORMS THROUGH MID WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE WILL PUSH OFF TO THE EAST/NORTHEAST TODAY AS A WARM
FRONT LIFTS NORTHEAST THROUGH THE REGION. WAA INDUCED CLOUDS WILL
SPREAD QUICKLY INTO THE AREA THIS MORNING. MOSAIC RADAR TO OUR
WEST WAS INDICATING SOME SHOWER ACTIVITY MOVING INTO CENTRAL
INDIANA. LATEST HRRR PUSHES THESE SHOWERS INTO THE
WHITEWATER/MIAMI VALLEY AND WEST CENTRAL OHIO DURING THE MORNING
HOURS. HAVE INCLUDED A CHANCE OF SHOWERS HERE. OTHERWISE...SKIES
SHOULD BECOME MOSTLY SUNNY BY AFTERNOON AS SOUTHERLY WINDS
INCREASE. TEMPERATURES WILL HAVE A SLOW START DUE TO COOL
OVERNIGHT LOWS AND CLOUDS...BUT WE SHOULD SEE A LATE WARM PUSH
WITH SUNSHINE AND SOUTHERLY WINDS. HIGHS WILL RANGE FROM THE MID
60S FAR NORTH TO THE LOWER 70S SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
FORECAST AREA WILL BE WEDGED BETWEEN A S/WV MOVING ACRS THE SE
U.S. AND A STORM SYSTEM ACRS THE NORTHERN PLAINS/UPR MS RIVER VLY
TONIGHT. SKIES WILL BE MOSTLY CLEAR EARLY WITH INCREASING CLOUDS
LATE AS MOISTURE BEGINS TO SEEP NORTHWARD INTO THE OHIO VALLEY.
FOR MONDAY...A COLD FRONT WILL SLOWLY APPROACH THE REGION FROM THE
WEST. A MIX OF CLOUDS AND SUN ALONG WITH SOUTHERLY FLOW SHOULD
BOOST TEMPERATURES INTO THE LOWER AND MID 70S. SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH THE FRONT SHOULD HOLD OFF FOR THE
MOST PART ACRS THE FAR NW CWFA...BUT WE SHOULD SEE CHANCES
INCREASE TOWARD MONDAY EVENING. THE FRONT IS EXPECTED TO SAG
SLOWLY INTO THE NRN ZONES MONDAY NIGHT...BRINGING AN INCREASING
THREAT FOR SHOWERS AND STORMS HERE AS A MODEST LOW LEVEL JET AND
FRONTAL CONVERGENCE OCCUR.
FOR THE PERIOD TUESDAY INTO TUESDAY NIGHT...MODELS CONTINUE TO
OFFER DIFFERENT SOLUTIONS IN THE TIMING OF THE FRONT AS IT SINKS
SOUTH TOWARD THE OHIO RIVER. THE TIMING WILL HAVE SIGNIFICANT PCPN
AND TEMPERATURE IMPLICATIONS AS THOSE ON THE COOL SIDE OF THE
BOUNDARY WILL SEE MUCH COOLER TEMPERATURES VERSUS THOSE ON THE
WARM SIDE. WILL KEEP LIKELY POPS GOING ACRS THE NRN ZONES TUESDAY
MORNING AND THEN WILL TAPER POPS TO A CHANCE REGION WIDE AS IT IS
HARD TO DISCERN ANY EMBEDDED IMPULSES ALOFT TO AID FRONTAL
CONVERGENCE FOR SHOWER/STORM ACTIVITY. AGAIN...MODELS SUGGEST THAT
THE FRONT WILL STALL OUT NEAR OR SOUTH OF THE OHIO BY WEDNESDAY
MORNING.
FOR WEDNESDAY INTO WEDNESDAY NIGHT...FRONT SHOULD BEGIN TO LIFT
BACK NORTH AS A WARM FRONT AS A STRONGER S/WV AND ASSOCD MID LVL
TROF EJECT FROM THE FOUR CORNERS REGION INTO THE PLAINS...WHICH
WILL FORCE THE MID LVL FLOW TO BUCKLE ACRS OUR REGION. WILL
CONTINUE WITH THE CHANCE OF SHOWERS AND STORMS.
AS FOR TEMPERATURES FOR THE REMAINDER OF THE PERIOD...HAVE TAKEN
A CONSENSUS OF RAW MODEL VALUES GIVEN THE UNCERTAINTY OF THE
PLACEMENT OF THE FRONT.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AN UPPER LEVEL TROUGH WILL PIVOT INTO THE AREA LATE IN THE WORK
WEEK. THIS WILL HELP DRIVE A STRONG COLD FRONT THROUGH THE REGION
THURSDAY INTO FRIDAY. THIS WILL RESULT IN AN INCREASING CHANCE OF
THUNDERSTORMS FROM THE WEST THURSDAY AFTERNOON INTO THURSDAY
EVENING. AS THE FRONT MOVES THROUGH THURSDAY NIGHT...THUNDERSTORMS
SHOULD TAPER OFF TO SOME SHOWERS. TEMPERATURES THURSDAY NIGHT INTO
FRIDAY WILL BE TRICKY DEPENDING ON THE TIMING OF THE FRONT...BUT
WILL LIKELY END UP WITH A PERIOD OF NON DIURNAL TEMPS DURING THAT
PERIOD AS MUCH COOLER AIR FILTERS IN BEHIND THE FRONT. SOME WRAP
AROUND MOISTURE COULD LEAD TO A FEW SHOWERS THROUGH THE DAY ON
FRIDAY. DRIER AIR WILL PUSH IN FOR FRIDAY NIGHT AND SATURDAY...BUT
TEMPERATURES WILL REMAIN BELOW NORMAL HEADING INTO THE WEEKEND.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL BE THE RULE THROUGH THE TAF PERIOD. HIGH
PRESSURE WILL DEPART THE REGION TO THE EAST OVERNIGHT...ALLOWING
WINDS TO SWITCH TO THE SOUTH-SOUTHEAST DURING THE DAY SUNDAY.
THERE WILL BE MID-CLOUDS OVER THE REGION OVERNIGHT...WITH SOME OF
THEM STAYING IN PLACE INTO THE DAY.
A FEW LIGHT SHOWERS OR SPRINKLES ARE EXPECTED TO DEVELOP OVER
INDIANA DURING THE NEXT FEW HOURS. THESE MAY IMPACT THE DAYTON TAF
SITE NEAR SUNRISE...BUT NO IMPACTS TO AVIATION CONDITIONS ARE EXPECTED.
SUNDAY NIGHT...WINDS WILL SHIFT TO THE SOUTH...AND ADDITIONAL
MOISTURE WILL BEGIN TO WORK INTO THE AREA.
OUTLOOK...SHOWERS AND THUNDERSTORMS ARE POSSIBLE FROM TUESDAY
THROUGH THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...JGL
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
152 PM EDT SUN APR 14 2013
.SYNOPSIS...
THIS AFTERNOON...THE REGION WILL REMAIN UNDER A WEDGE OF HIGH
PRESSURE AS A DEVELOPING LOW PRESSURE SYSTEM MOVES OUT OF THE GULF
OF MEXICO. THE LOW WILL PASS OVER OR JUST SOUTH OF THE REGION
AND OFF THE SOUTHEAST COASTLINE TONIGHT INTO EARLY MONDAY. HIGH
PRESSURE WILL GRADUALLY STRENGTHEN OVER THE WESTERN ATLANTIC
TUESDAY THROUGH FRIDAY BEFORE A COLD FRONT MOVES IN FRIDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY SUNDAY AFTERNOON...OVERRUNNING PRECIPITATION CONTINUED TO
OVERSPREAD SOUTHERN/WESTERN COUNTIES OF THE FORECAST AREA.
PER AREA RADAR TRENDS AND 11Z HRRR HIGH RESOLUTION GUIDANCE WHICH
APPEARS TO HAVE A REASONABLE HANDLE ON PRECIPITATION EVOLUTION...
CONTINUED TO RAISE POPS AND ACCELERATE THE N/E PROGRESS OF
SHOWERS. MAX AFTERNOON POPS ARE NOW GRADUATED FROM CATEGORICAL
S/W TO CHANCE N/E. QPF SHOULD REMAIN LIMITED THROUGH LATE
AFTERNOON...WITH 0.25 TO 0.50 INCH WHERE LONGEST DURATION
PRECIPITATION OCCURS ACROSS S/E...WITH ELEVATED CONVECTION/LOCALLY
HEAVIER RAINFALL RATES ARRIVING THIS EVENING.
ISOLATED/ELEVATED THUNDERSTORMS COULD PUSH INTO LOCATIONS NEAR THE
ALTAMAHA RIVER/ADJACENT COASTAL WATERS BY LATE AFTERNOON...BUT THE
POTENTIAL FOR ANY SEVERE WEATHER WILL REMAIN VERY LOW THROUGH LATE
AFTERNOON.
AFTERNOON TEMPERATURES WILL REMAIN IN THE 60S WHERE SHOWERS HAVE
ALREADY ARRIVED WITHIN THE WEDGE REGIME ACROSS S/W COUNTIES...AND
TEMPERATURES IN THE LOWER TO MID 70S FARTHER N/E WILL FALL BACK
INTO THE 60S AS SHOWERS ARRIVE...LATEST ACROSS THE CHS TRI-COUNTY
REGION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
TONIGHT...A COMPLEX AND INTERESTING PERIOD INDEED AS IMPRESSIVE
DYNAMICS ROLL THROUGH WITH HINTS OF SOME UPPER JET COUPLING.
SURFACE LOW PRES WAVES WILL RIPPLE ALONG A LIFTING WARM FRONT
OVERNIGHT WITH INCREASING LOW LEVEL CONVERGENCE AND MAINLY
ELEVATED INSTABILITY LIFTING NORTHWARD WITH TIME. MODELS HAVE
THEIR USUAL TIMING AND PLACEMENT DIFFERENCES WITH THE FEATURES BUT
A FEW THINGS CAUGHT OUR EYE FROM THE GFS/ECMWF. BOTH MODELS PROG
AT LEAST 50-60 KT OF BULK SHEAR THROUGH OUR SOUTHERN ZONES AND WE
ARE GOING TO NEED TO KEEP CLOSE TABS ON THE PROGRESSION OF THE
WARM FRONT AFTER MIDNIGHT. WE THINK AN INITIAL SHOT OF ELEVATED
CONVECTIVE RAINS WILL LOCK IN PLENTY OF LOW LEVEL STABILITY ACROSS
THE FORECAST AREA...BUT THERE COULD BE A SMALL CHANCE FOR
WORRISOME INSTABILITY ALONG SE GEORGIA CLOSE TO THE ALTAMAHA RIVER
AND POSSIBLY AN OVERNIGHT WARM FRONT GATE FEATURE NEARING THE
COASTAL PARTS OF SE SOUTH CAROLINA...MORE LIKELY TO REMAIN OFFSHORE.
WITH THE AMOUNT OF FORCING AND INSTABILITY GRADIENTS PROGGED...
ISOLATED SEVERE WEATHER FROM ELEVATED HAIL AND A SMALL POTENTIAL
RISK OF A TORNADO ALONG AND S OF THE WARM FRONT CANNOT BE RULED
OUT. AT THIS TIME IT APPEARS THE GREATER RISK WILL BE ALONG AND
S OF THE ALTAMAHA RIVER ENTRANCE REGION. CHANCES AT THIS TIME NOT
ENOUGH TO WARRANT MENTIONS IN OUR HAZARDOUS WEATHER OUTLOOK.
ANOTHER POTENTIAL ISSUE WILL BE LOCALLY HEAVY CONVECTIVE RAINFALL...
ESPECIALLY FALLING AROUND TIMES OF A NEAR MIDNIGHT HIGH TIDE IN
COASTAL AREAS. OVERALL...THE PROGRESSIVE NATURE OF THIS SYSTEM IS
SUCH THAT QPF AMOUNTS HELD DOWN BUT NOT RULING OUT SOME LOCALIZED
HEAVY RAINS. OTHERWISE...PLENTY OF SHOWERS AND TSTMS SWEEPING
THOUGH GEORGIA INTO SOUTH CAROLINA TONIGHT WITH MILD TEMPS HANGING
UP IN THE LOWER 60S.
A BROAD 500 MB RIDGE WILL BUILD IN MONDAY THROUGH WEDNESDAY. ON
MONDAY A WEAK SURFACE WEDGE OF HIGH PRESSURE WILL REMAIN ACROSS
SOUTHERN SC ALONG WITH CONSIDERABLE MOISTURE BELOW 800 MB. WEAK
FORCING ON THE WESTERN PERIPHERY OF THE DEPARTING LOW MAY ALLOW FOR
SCATTERED SHOWERS MAINLY THROUGH EARLY AFTERNOON. EXTENSIVE CLOUD
COVER AND WEAK COLD ADVECTION WILL LIMIT HIGH TEMPS TO THE MID TO
UPPER 70S.
AS UPPER HEIGHTS RISE ON TUESDAY...THE SURFACE HIGH WILL SHIFT OFF
THE COAST. SOME LOW-LEVEL DRYING WILL SCOUR OUT SOME OF THE CLOUD
COVER BUT AN ONSHORE FLOW WILL MAINTAIN ENOUGH BOUNDARY LAYER
MOISTURE TO SUPPORT OVERNIGHT STRATOCU AND CUMULUS DEVELOPMENT
DURING DAYTIME HOURS. KNOCKING A COUPLE DEGREES OF THICKNESS PROGS
TO ACCOUNT FOR THE CLOUDS GIVES US HIGHS IN THE LOWER 80S EXCEPT MID
70S AT THE COAST DUE TO THE ONSHORE FLOW AND SEABREEZE.
TEMPS WILL BE ANOTHER 1-3 DEGREES WARMER ON WEDNESDAY UNDER PARTLY
TO MOSTLY SUNNY SKIES. WE KEPT A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS ACROSS FAR INLAND GA WHERE SOME LOW-LEVEL INSTABILITY
AND -4 TO -5C LIFTED INDICES MAY SUPPORT SOME CONVECTION ONCE THE
SEABREEZE PUSHES INLAND.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
THE UPPER RIDGE WILL HANG ON FOR ONE MORE DAY BEFORE A LARGE SCALE
PATTERN SHIFT OCCURS. A PRONOUNCED LONGWAVE TROUGH WILL SPREAD
ACROSS PRETTY MUCH THE ENTIRE CONTIGUOUS UNITED STATES FRIDAY
THROUGH SUNDAY. A STRONG COLD FRONT WILL SWEEP THROUGH THE AREA
FRIDAY NIGHT WITH DRY CANADIAN HIGH PRESSURE BUILDING IN ITS WAKE.
WE EXPECT DECENT COVERAGE OF SHOWERS AND THUNDERSTORMS FRIDAY
AFTERNOON THROUGH FRIDAY NIGHT...THEN DRIER AND MUCH COOLER WEATHER
FOR THE WEEKEND. HIGHS ON SATURDAY COULD STRUGGLE TO REACH 70
DEGREES AND SATURDAY NIGHT WE COULD SEE SOME UPPER 40S IN SPOTS.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
VFR INTO THIS EVENING...EVEN FOR A TIME AFTER SHOWERS ARRIVE
INITIALLY AT KSAV AND BY EARLY EVENING AT KCHS DUE TO RELATIVELY
DRY LOW LEVEL AIRMASS IN PLACE. HOWEVER...FLIGHT CONDITIONS WILL
DETERIORATE TONIGHT...PERHAPS GRADUALLY THROUGH MVFR TO IFR OR
RAPIDLY TO IFR/LIFR AS LOW CLOUDS/FOG DEVELOP IN PLACE.
MEANWHILE...ELEVATED THUNDERSTORMS COULD OCCUR AT EITHER TERMINAL
TONIGHT...BUT THE ODDS ARE SOMEWHAT GREATER AT KSAV THUS INCLUDED
A PERIOD OF VCTS THERE. AFTER PRECIPITATION ENDS...LOW LEVEL
MOISTURE/FLIGHT RESTRICTIONS WILL LINGER AT LEAST THROUGH MONDAY
MORNING...THUS INDICATED ONLY MODEST IMPROVEMENT TO MVFR CEILINGS
AS THE BOUNDARY LAYER WARMS/DEEPENS BEGINNING AROUND 15Z MONDAY.
EXTENDED AVIATION OUTLOOK...MVFR/IFR CONDITIONS LIKELY LATE SUNDAY
NIGHT INTO MONDAY MORNING...OTHERWISE MVFR CEILINGS AND SOME
SHALLOW GROUND FOG POSSIBLE DURING THE OVERNIGHT HOURS MONDAY
THROUGH THURSDAY.
&&
.MARINE...
A TIGHTENING SURFACE PRESSURE GRADIENT BETWEEN A RIDGE OF HIGH
PRESSURE CENTERED N/W OF THE WATERS AND A SURFACE WAVE OF LOW
PRESSURE EJECTING ENE FROM THE GULF OF MEXICO WILL MAINTAIN
ONSHORE FLOW THIS AFTERNOON...WITH WINDS INCREASING/SEAS BUILDING
TONIGHT. CAPPED WINDS AT 20 KT AND SEAS AT 4-5 FT THIS
AFTERNOON... BUT FORECAST UNCERTAINTY REMAINS HIGH AS GRADIENTS
COULD BECOME TIGHTER THAN EXPECTED SUPPORTING HIGHER WINDS/LARGER
SEAS THAN CURRENTLY EXPECTED LATER TODAY OR TONIGHT.
WE INDICATE SEAS BUILDING TO 4 TO 6 FT BRIEFLY TONIGHT OVER OUTER
GEORGIA WATERS BEYOND 20 NM BUT WERE HESITANT TO ISSUE THE SMALL
CRAFT ADVISORY JUST YET GIVEN UNCERTAINTIES WITH THE PROGRESSION
OF THE WARM FRONT. WE CANNOT RULE OUT MARGINAL SCA CONDITIONS
ALONG PARTS OF THE UPPER SOUTH CAROLINA COAST THIS EVENING IF
THE GRADIENT PINCHES AND EVEN AT FORT PULASKI THIS AFTERNOON
WITH OCCASIONAL WIND GUSTS EXCEED 20 KT. ALSO OF CONCERN...
THUNDERSTORMS...A FEW STRONG...COULD IMPACT THE COASTAL WATERS
TONIGHT.
A MODERATE ONSHORE FLOW WILL PREVAIL MONDAY THROUGH THURSDAY AS HIGH
PRESSURE GRADUALLY BUILDS OVER THE WESTERN ATLANTIC. DECENT
SEA-BREEZES EXPECTED EACH AFTERNOON ALONG THE COAST AS INLAND AREAS
WARM UP. WINDS WILL BECOME SOUTHERLY THURSDAY NIGHT AND FRIDAY AHEAD
OF A COLD FRONT. SMALL CRAFT ADVISORY WINDS/SEAS MAY DEVELOP AHEAD
OF THE FRONT...THEN PERSIST IN ITS WAKE ON SATURDAY AS WINDS SHIFT
TO NNE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...SPR
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...SPR
MARINE...JRL/SPR
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1227 PM CDT SUN APR 14 2013
.DISCUSSION...
ISSUED 1015 AM CDT SUN APR 14 2013
REMAINDER OF SHOWERS/SPRINKLES HAVE PUSHED INTO INDIANA. WHILE
REGIONAL RADAR MOSAICS SHOW SOME SHOWERS OVER CENTRAL ILLINOIS...
THIS IS DUE TO THE MORE DISTANT RADAR BEAMS REACHING THE
ALTOCUMULUS LAYER...AS THE LINCOLN RADAR IS PRETTY CLEAR DIRECTLY
OVER CENTRAL ILLINOIS. CU-RULE IS LARGELY ABOVE ZERO THIS
AFTERNOON INDICATING LOW CHANCES OF CUMULUS...ALTHOUGH A TONGUE OF
IT IS PROGGED TO MOVE NORTHEAST FROM THE ST LOUIS AREA LATE IN THE
AFTERNOON...AND THUS ANY ADDITIONAL PRECIP SHOULD BE SPRINKLES AT
BEST.
MAIN CONCERN REMAINS WITH THE WINDS TODAY. VAD WINDS OFF THE
LINCOLN AND ST LOUIS RADARS SHOWING 40 KNOTS ON THE LOWEST GATE AT
10 AM. WITH THE ALTOCUMULUS TRYING TO LIFT OUT...SHOULD START
SEEING SOME INCREASED MIXING TO BRING THIS DOWN TO THE SURFACE...
HOWEVER THERE IS A DECENT CIRRUS SHIELD OVER ABOUT THE SOUTHEAST
HALF OF THE CWA IN ASSOCIATION WITH CONVECTION ACROSS THE SOUTHEAST
U.S. LATEST RAP AND HRRR SHOWING THE 3 TO 6 PM TIME FRAME AS MOST
LIKELY TO SEE THE HIGHEST WIND GUSTS OF 40-45 MPH. NO HEADLINE
CHANGES PLANNED AS THE SOUTHEAST CWA STILL IS RATHER BORDERLINE
WITH THE WINDS. TEMPERATURES LOOKING GOOD SO FAR AND NO CHANGES
WERE MADE...ALTHOUGH THERE WERE SOME DOWNWARD ADJUSTMENTS IN THE
DEW POINT GRIDS.
GEELHART
&&
.AVIATION...
ISSUED 1225 PM CDT SUN APR 14 2013
INITIAL CONCERNS ARE WITH WINDS...WHICH HAVE BEEN INCREASING WEST
OF KBMI-KSPI IN THE CLEAR SLOT. HIGHEST GUSTS LIKELY IN THE
21-00Z TIME FRAME IN THESE AREAS. AREA FURTHER EAST WILL SEE HIGH
CLOUDS WHICH MAY TEMPER THE MIXING SOME...BUT SHOULD STILL SEE
SOUTHERLY WINDS GUSTING TO AROUND 30 KNOTS. DURING THE EVENING...A
COLD FRONT WILL APPROACH FROM THE WEST...LOWERING CEILINGS TO
AROUND 5000 FEET BY THE TIME ASSOCIATED SHOWER AND THUNDERSTORM
ACTIVITY ARRIVES...LIKELY TOWARD 06Z AT KPIA AND SLOWLY MOVING TO
THE OTHER TAF SITES. GUIDANCE SUGGESTING SOME TEMPO PERIODS OF
MVFR CEILINGS/VISIBILITIES AS THE FRONT PASSES...THEN IMPROVEMENT
AFTER ABOUT 09-10Z.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 300 AM CDT SUN APR 14 2013
FORECAST CONCERN TODAY IS HOW STRONG SOUTHERLY WINDS GET AND IF
WIND ADVISORY NEEDED. MODELS AGREE WITH BIG WARM UP TODAY INTO THE
LOW TO MID 70S WITH MOSTLY SUNNY SKIES DEVELOPING FROM SOUTH TO NORTH.
00Z MODEL SUITE CONTINUES TO ADVERTISE A VERY UNSETTLED WEATHER
PATTERN THIS WORK WEEK WITH BEST CHANCES OF SHOWERS AND
THUNDERSTORMS WITH HEAVIEST RAINS OCCURRING WED AFTERNOON INTO THU.
SHORT TERM...TODAY THROUGH THURSDAY
RADAR MOSAIC AND SURFACE OBS SHOW A BAND OF WAA SHOWERS AND EVEN A
FEW ISOLATED THUNDERSTORMS AT TIMES OVER CENTRAL IL AND LIFTING
NE OF A SPRINGFIELD TO EFFINGHAM LINE AND AS FAR NE AS I-74. THIS
BAND OF CONVECTION TO CONTINUE LIFTING NE THIS MORNING AND BE NE
OF CENTRAL IL BY MID MORNING. EARLY MORNING SURFACE MAP SHOWS
STRONG 988 MB LOW PRESSURE STILL DEEPENING OVER SE CO INTO NW KS
WHILE ITS WARM FRONT EXTENDED EASTWARD OVER NORTHERN KS INTO
CENTRAL MO. WEAK 1019 MB HIGH PRESSURE WAS OVER SE OHIO AND
DRIFTING EAST AWAY FROM IL. TEMPS WERE IN THE 40S OVER CENTRAL/SE
IL EARLY THIS MORNING...RANGING FROM LOWER 40S AT DANVILLE AND
PARIS TO THE UPPER 40S FROM MACOMB TO SPRINGFIELD TO EFFINGHAM AND
OLNEY SW. ESE WINDS WERE 5-15 MPH. ALOFT A STRONG 532 DM 500 MB
LOW WAS NE OF LAKE SUPERIOR WHILE A 535 DM 500 MB LOW WAS OVER
WESTERN MT. UPPER LEVEL RIDGING WAS OVER FL AND OFF THE CA COAST.
STRONG LOW PRESSURE OVER SE CO/NW KS TO WEAKEN TO 996 MB AT IT
EJECTS NE TO THE SD/MN BORDER BY THIS EVENING. THIS TO BRING ANOTHER
MAJOR WINTER STORM TO PARTS OF MT/ND AND MN...WHILE IL STAYS ON
THE WARM SIDE OF THIS STRONG STORM SYSTEM WITH INCREASING PRESSURE
GRADIENT TODAY LEADING TO SOUTHERLY WINDS APPROACHING WIND
ADVISORY CRITERIA (SUSTAINED 30 MPH FOR AN HOUR OR MORE AND OR
WIND GUSTS OF 45 MPH OR HIGHER) THIS AFTERNOON NW OF I-70 AND
FROM I-57 WEST. WILL ISSUE A WIND ADVISORY THIS AFTERNOON FOR
CENTRAL IL NORTH OF I-70 FROM NOON TO 7 PM...THOUGH EDGAR AND
VERMILION COUNTIES AROUND DANVILLE AND PARIS MAY STRUGGLE TO REACH
THE WIND ADVISORY CRITERIA THIS AFTERNOON. HIGHS IN THE LOW TO MID
70S THIS AFTERNOON WHICH IS ABOUT 10 DEGREES ABOVE NORMAL FOR MID
APRIL.
STRONG SURFACE AND CUTOFF LOW TO LIFT NE ACROSS MN TONIGHT WHILE
BRINGING A COLD FRONT SE ACROSS THE IL RIVER VALLEY OVERNIGHT...
RE TURING A CHANCE OF SHOWERS AND THUNDERSTORMS TO CENTRAL IL
ESPECIALLY NW AREAS AND INCREASE POPS IN THIS AREA. MODELS
GRADUALLY SHIFT THE COLD FRONT INTO SE IL DURING THE DAY MON AND
CONTINUES CHANCES OF SHOWERS AND THUNDERSTORMS...WHICH GET INTO SE
IL TOO ON MONDAY. SPC KEEPS SLIGHT RISK OF SEVERE STORMS SW OF OUR
SE COUNTIES FOR MON/MON NIGHT BUT WILL NEED TO BE WATCHED FOR
AREAS SE OF I-70 WHICH WILL BE CLOSEST TO THE FRONTAL BOUNDARY
WHICH IS BECOMING QUASI-STATIONARY FOR A TIME INTO TUE AND CONTINUES
CHANCES OF SHOWERS/THUNDERSTORMS ACROSS CENTRAL/SE IL. WILL BE A
FAIRLY STRONG TEMP GRADIENT FROM NW TO SE MON/TUE WITH WARMEST
READINGS IN SE IL WHERE HIGHS 70-75F WHILE MID TO UPPER 50S OVER
THE IL RIVER VALLEY OF NW IL.
BEST CHANCES OF SHOWERS AND THUNDERSTORMS WITH POSSIBLE HEAVY
RAINS TO OCCUR FROM WED AFTERNOON INTO THU...GRADUALLY SHIFTING
INTO EASTERN IL THU. RAINFALL AMOUNTS OF 2-3 INCHES POSSIBLE BY
THU NIGHT ACROSS AREA. STILL SOME TIMING DIFFERENCES WITH STRONG
LOW PRESSURE AND COLD FRONT MOVING THROUGH CENTRAL IL WED NIGHT
AND SE IL THU MORNING.
LONG TERM...THURSDAY NIGHT THROUGH SUNDAY
SHOWERS TO BECOME LIGHTER AND MORE SCATTERED IN NATURE THU NIGHT
AND FRI WITH STRONG STORM SYSTEM EXITING EAST OF IL. THOUGH STRONG
UPPER LEVEL TROF MOVING EAST INTO IL FRIDAY TO KEEP LOW CLOUDS
AROUND ALONG WITH CHANCES OF LIGHT SHOWERS AND BELOW NORMAL
TEMPERATURES. A FEW MODELS ARE SHOWING A SLIPPER SYSTEM BRINGING
SOME QPF INTO IL THIS WEEKEND THOUGH WILL ONLY CARRY SLIGHT CHANCE
POPS AT BEST SAT NIGHT AND SUNDAY. COLDEST TEMPS EXPECTED FRIDAY
AND FRI NIGHT WHEN LOWS COULD REACH AROUND FREEZING. TEMPS MODIFY
INTO THE 50S THIS WEEKEND WHICH IS ABOUT 10 DEGREES COLDER THAN
NORMAL.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ILZ027>031-036>038-
040>057-061.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1018 AM CDT SUN APR 14 2013
.DISCUSSION...
ISSUED 1015 AM CDT SUN APR 14 2013
REMAINDER OF SHOWERS/SPRINKLES HAVE PUSHED INTO INDIANA. WHILE
REGIONAL RADAR MOSAICS SHOW SOME SHOWERS OVER CENTRAL ILLINOIS...
THIS IS DUE TO THE MORE DISTANT RADAR BEAMS REACHING THE
ALTOCUMULUS LAYER...AS THE LINCOLN RADAR IS PRETTY CLEAR DIRECTLY
OVER CENTRAL ILLINOIS. CU-RULE IS LARGELY ABOVE ZERO THIS
AFTERNOON INDICATING LOW CHANCES OF CUMULUS...ALTHOUGH A TONGUE OF
IT IS PROGGED TO MOVE NORTHEAST FROM THE ST LOUIS AREA LATE IN THE
AFTERNOON...AND THUS ANY ADDITIONAL PRECIP SHOULD BE SPRINKLES AT
BEST.
MAIN CONCERN REMAINS WITH THE WINDS TODAY. VAD WINDS OFF THE
LINCOLN AND ST LOUIS RADARS SHOWING 40 KNOTS ON THE LOWEST GATE AT
10 AM. WITH THE ALTOCUMULUS TRYING TO LIFT OUT...SHOULD START
SEEING SOME INCREASED MIXING TO BRING THIS DOWN TO THE SURFACE...
HOWEVER THERE IS A DECENT CIRRUS SHIELD OVER ABOUT THE SOUTHEAST
HALF OF THE CWA IN ASSOCIATION WITH CONVECTION ACROSS THE SOUTHEAST
U.S. LATEST RAP AND HRRR SHOWING THE 3 TO 6 PM TIME FRAME AS MOST
LIKELY TO SEE THE HIGHEST WIND GUSTS OF 40-45 MPH. NO HEADLINE
CHANGES PLANNED AS THE SOUTHEAST CWA STILL IS RATHER BORDERLINE
WITH THE WINDS. TEMPERATURES LOOKING GOOD SO FAR AND NO CHANGES
WERE MADE...ALTHOUGH THERE WERE SOME DOWNWARD ADJUSTMENTS IN THE
DEW POINT GRIDS.
GEELHART
&&
.AVIATION...
ISSUED 628 AM CDT SUN APR 14 2013
VFR CONDITIONS SHOULD PREVAIL AT ALL TAF SITES MOST OF THE TAF
PERIOD...EXCEPT FOR WHEN THE FRONTAL SYSTEM MOVES INTO THE AREA
LATE TONIGHT. MID AND HIGH CLOUDS WILL PREVAIL AT ALL SITES AS A
WARM FRONT LIFTS NORTHWARD TODAY...ENDING ANY THREAT FOR PCPN THIS
MORNING. THE AREA WILL SEE A LITTLE CU AROUND 5KFT REST OF THE DAY
AHEAD OF THE NEXT WEATHER SYSTEM. THEN MODELS FORECAST SHOWERS AND
THUNDERSTORMS MOVING INTO THE AREA CLOSE TO MIDNIGHT...REACHING
PIA 04Z AND SPI/BMI BY 06Z. WILL START AS VCTS BUT THEN BRING IN
TEMPO GROUP OF THUNDERSTORMS ON STATION AT 05Z AT PIA AND 07Z AT
SPI/BMI. THE VCTS WILL BEGIN AT DEC AT 08Z AND AT 09Z AT CMI.
MODELS FORECAST PCPN DIMINISHING AS IT MOVES EAST SO WILL NOT ADD
TEMPO GROUP AT THIS TIME DUE TO HIGH DEGREE OF UNCERTAINTY. WINDS
WILL BE WINDY TODAY...BECOMING VERY WINDY AND GUSTY THIS
AFTERNOON. TAFS WILL HAVE GUSTS AS HIGH AS 35-37KTS FOR THIS
AFTERNOON. WINDS WILL DIMINISH SOMEWHAT RIGHT AFTER SUNSET. WIND
DIRECTION WILL BE SOUTHERLY THROUGH THE PERIOD.
AUTEN
&&
.PREV DISCUSSION...
ISSUED 300 AM CDT SUN APR 14 2013
FORECAST CONCERN TODAY IS HOW STRONG SOUTHERLY WINDS GET AND IF
WIND ADVISORY NEEDED. MODELS AGREE WITH BIG WARM UP TODAY INTO THE
LOW TO MID 70S WITH MOSTLY SUNNY SKIES DEVELOPING FROM SOUTH TO NORTH.
00Z MODEL SUITE CONTINUES TO ADVERTISE A VERY UNSETTLED WEATHER
PATTERN THIS WORK WEEK WITH BEST CHANCES OF SHOWERS AND
THUNDERSTORMS WITH HEAVIEST RAINS OCCURRING WED AFTERNOON INTO THU.
SHORT TERM...TODAY THROUGH THURSDAY
RADAR MOSAIC AND SURFACE OBS SHOW A BAND OF WAA SHOWERS AND EVEN A
FEW ISOLATED THUNDERSTORMS AT TIMES OVER CENTRAL IL AND LIFTING
NE OF A SPRINGFIELD TO EFFINGHAM LINE AND AS FAR NE AS I-74. THIS
BAND OF CONVECTION TO CONTINUE LIFTING NE THIS MORNING AND BE NE
OF CENTRAL IL BY MID MORNING. EARLY MORNING SURFACE MAP SHOWS
STRONG 988 MB LOW PRESSURE STILL DEEPENING OVER SE CO INTO NW KS
WHILE ITS WARM FRONT EXTENDED EASTWARD OVER NORTHERN KS INTO
CENTRAL MO. WEAK 1019 MB HIGH PRESSURE WAS OVER SE OHIO AND
DRIFTING EAST AWAY FROM IL. TEMPS WERE IN THE 40S OVER CENTRAL/SE
IL EARLY THIS MORNING...RANGING FROM LOWER 40S AT DANVILLE AND
PARIS TO THE UPPER 40S FROM MACOMB TO SPRINGFIELD TO EFFINGHAM AND
OLNEY SW. ESE WINDS WERE 5-15 MPH. ALOFT A STRONG 532 DM 500 MB
LOW WAS NE OF LAKE SUPERIOR WHILE A 535 DM 500 MB LOW WAS OVER
WESTERN MT. UPPER LEVEL RIDGING WAS OVER FL AND OFF THE CA COAST.
STRONG LOW PRESSURE OVER SE CO/NW KS TO WEAKEN TO 996 MB AT IT
EJECTS NE TO THE SD/MN BORDER BY THIS EVENING. THIS TO BRING ANOTHER
MAJOR WINTER STORM TO PARTS OF MT/ND AND MN...WHILE IL STAYS ON
THE WARM SIDE OF THIS STRONG STORM SYSTEM WITH INCREASING PRESSURE
GRADIENT TODAY LEADING TO SOUTHERLY WINDS APPROACHING WIND
ADVISORY CRITERIA (SUSTAINED 30 MPH FOR AN HOUR OR MORE AND OR
WIND GUSTS OF 45 MPH OR HIGHER) THIS AFTERNOON NW OF I-70 AND
FROM I-57 WEST. WILL ISSUE A WIND ADVISORY THIS AFTERNOON FOR
CENTRAL IL NORTH OF I-70 FROM NOON TO 7 PM...THOUGH EDGAR AND
VERMILION COUNTIES AROUND DANVILLE AND PARIS MAY STRUGGLE TO REACH
THE WIND ADVISORY CRITERIA THIS AFTERNOON. HIGHS IN THE LOW TO MID
70S THIS AFTERNOON WHICH IS ABOUT 10 DEGREES ABOVE NORMAL FOR MID
APRIL.
STRONG SURFACE AND CUTOFF LOW TO LIFT NE ACROSS MN TONIGHT WHILE
BRINGING A COLD FRONT SE ACROSS THE IL RIVER VALLEY OVERNIGHT...
RE TURING A CHANCE OF SHOWERS AND THUNDERSTORMS TO CENTRAL IL
ESPECIALLY NW AREAS AND INCREASE POPS IN THIS AREA. MODELS
GRADUALLY SHIFT THE COLD FRONT INTO SE IL DURING THE DAY MON AND
CONTINUES CHANCES OF SHOWERS AND THUNDERSTORMS...WHICH GET INTO SE
IL TOO ON MONDAY. SPC KEEPS SLIGHT RISK OF SEVERE STORMS SW OF OUR
SE COUNTIES FOR MON/MON NIGHT BUT WILL NEED TO BE WATCHED FOR
AREAS SE OF I-70 WHICH WILL BE CLOSEST TO THE FRONTAL BOUNDARY
WHICH IS BECOMING QUASI-STATIONARY FOR A TIME INTO TUE AND CONTINUES
CHANCES OF SHOWERS/THUNDERSTORMS ACROSS CENTRAL/SE IL. WILL BE A
FAIRLY STRONG TEMP GRADIENT FROM NW TO SE MON/TUE WITH WARMEST
READINGS IN SE IL WHERE HIGHS 70-75F WHILE MID TO UPPER 50S OVER
THE IL RIVER VALLEY OF NW IL.
BEST CHANCES OF SHOWERS AND THUNDERSTORMS WITH POSSIBLE HEAVY
RAINS TO OCCUR FROM WED AFTERNOON INTO THU...GRADUALLY SHIFTING
INTO EASTERN IL THU. RAINFALL AMOUNTS OF 2-3 INCHES POSSIBLE BY
THU NIGHT ACROSS AREA. STILL SOME TIMING DIFFERENCES WITH STRONG
LOW PRESSURE AND COLD FRONT MOVING THROUGH CENTRAL IL WED NIGHT
AND SE IL THU MORNING.
LONG TERM...THURSDAY NIGHT THROUGH SUNDAY
SHOWERS TO BECOME LIGHTER AND MORE SCATTERED IN NATURE THU NIGHT
AND FRI WITH STRONG STORM SYSTEM EXITING EAST OF IL. THOUGH STRONG
UPPER LEVEL TROF MOVING EAST INTO IL FRIDAY TO KEEP LOW CLOUDS
AROUND ALONG WITH CHANCES OF LIGHT SHOWERS AND BELOW NORMAL
TEMPERATURES. A FEW MODELS ARE SHOWING A SLIPPER SYSTEM BRINGING
SOME QPF INTO IL THIS WEEKEND THOUGH WILL ONLY CARRY SLIGHT CHANCE
POPS AT BEST SAT NIGHT AND SUNDAY. COLDEST TEMPS EXPECTED FRIDAY
AND FRI NIGHT WHEN LOWS COULD REACH AROUND FREEZING. TEMPS MODIFY
INTO THE 50S THIS WEEKEND WHICH IS ABOUT 10 DEGREES COLDER THAN
NORMAL.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ILZ027>031-036>038-
040>057-061.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1255 PM CDT SUN APR 14 2013
.UPDATE...
ISSUED AT 1249 PM CDT SUN APR 14 2013
UPDATED FORECAST MAINLY FOR THE POTENTIAL OF SQUALL LINE
DEVELOPMENT. LATEST VERSIONS OF THE HRRR LOOKED REASONABLE AND WITH
THE SLOWER MOVEMENT OF THE COLD FRONT IT APPEARS THERE IS A BETTER
CHANCE FOR SQUALL LINE DEVELOPMENT.
UPDATE ISSUED AT 455 AM CDT SUN APR 14 2013
HAVE UPDATED ZONES FOR CHANCE FOR LIGHT FREEZING RAIN IN FAR NORTH
EARLY TODAY...MAINLY BEFORE HEAVIER PRECIP ENTERS THE AREA. A
LIGHT GLAZING MAY OCCUR ON OBJECTS...BUT NOT MUCH EXPECTED ON
ROADS. OTHERWISE...GOING FORECAST REMAINS THE SAME.
&&
.SHORT TERM.../TODAY/...
ISSUED AT 351 AM CDT SUN APR 14 2013
STRONG WARM AIR ADVECTION AND UPPER LEVEL WARM FRONT CREATING AREA
OF CONVECTIVE SHOWERS ACROSS WESTERN IOWA EARLY THIS MORNING. WITH
THE AIRMASS QUITE COOL OVER IOWA THE AREA IS BEGINNING TO LOSE
LIGHTNING AND TRANSITION TO MODERATE SHOWERS. TEMPS ALOFT REMAIN
NEAR FREEZING AND HAVE HAD REPORTS OF SLEET MIXED IN WITH RAIN SO
HAVE UPDATED ZONES NORTH TO REFLECT THAT THROUGH 12Z. WILL ALSO NEED
TO WATCH A SMALL AREA OF NORTHERN IOWA FROM MASON CITY NORTHWARD FOR
THE NEXT FEW HOURS TO SEE IF ANY FREEZING RAIN DEVELOPS. IF IT
DOES...MAY NEED TO CONSIDER A BRIEF ADVISORY THERE...BUT WILL WAIT
FOR NOW AS WARM AIR MAY KEEP TEMPS JUST ABOVE FREEZING. AFTER
12Z...WARMING ALOFT AND NEAR THE SFC SHOULD RESULT IN ALL RAIN FOR
THE NORTHERN SECTIONS THOUGH IT WILL BE QUITE CHILLY EARLY IN THE
DAY WITH 30S TO AROUND 40 ACROSS NORTHERN IOWA. LOW STILL FORECAST
TO CUT ACROSS WESTERN IOWA AND THEN OCCLUDE BY 00Z OVER SOUTH
DAKOTA. STRONG H850 JET WILL ADVANCE INTO IOWA THIS MORNING WITH
WINDS OF 45 TO 50 KTS EXPECTED. SOUNDINGS SUGGEST THAT SOUTHEAST
WILL HAVE POTENTIAL TO REACH WIND ADVISORY CRITERIA GUSTS BY LATE
MORNING AND EARLY AFTERNOON... BEGINNING A BIT EARLIER IN THE
SOUTHWEST. EXPECTING WINDS TO REACH ABOUT 40+ FOR THE PERIOD FROM
15Z THROUGH 21Z WHEN THE FRONT SLIDES EAST AND FOR THE MOST PART ANY
PORTION OF THE ADVISORY WILL HAVE ABOUT 3 HOURS OF STRONGER WINDS.
TEMPS STILL EXPECTED TO MIX NICELY TODAY WITH BRIEF WARM SECTOR
IMPINGING ON THE REGION...AFTERNOON HIGHS WILL RISE INTO THE UPPER
60S TO LOWER 70S SOUTH AND REMAIN IN THE LOWER TO MID 50S IN THE FAR
NORTH. SHOWERS AND THUNDERSTORMS WILL DEVELOP AHEAD OF THE BOUNDARY
THIS AFTERNOON SOUTHEAST WITH COVERAGE INCREASING AFTER 18Z THERE.
WITH THE STORMS WILL COME A SMALL RISK OF GUSTY WINDS AND HAIL AND
PERHAPS AN ISOLATED STORM HAVING EITHER A SEVERE WIND GUST OR
MINIMALLY SEVERE HAIL BETWEEN 20 AND 00Z THIS AFTERNOON. RAINFALL
AMOUNTS OF .25 TO OVER .50 INCHES WILL ACCOMPANY THE AREA OF RAIN
AND MIXED SLEET HEADING NORTHEAST INTO NORTHERN IOWA THIS MORNING.
LATER THIS AFTERNOON THUNDERSTORMS WILL DEPOSIT ANOTHER .25 TO .50
INCHES OVER THE EAST/SOUTHEAST BY THIS EVENING.
.LONG TERM.../TONIGHT THROUGH SATURDAY/...
ISSUED AT 351 AM CDT SUN APR 14 2013
LOW PRESSURE OVER THE NORTHERN PLAINS WILL DEEPEN AS AN UPPER LEVEL
JET PUSHES ACROSS THE ROCKIES THEN ACROSS NEBRASKA AND INTO IOWA
TONIGHT. MEANWHILE NEAR THE SURFACE...LOW PRESSURE OVER EASTERN
NEBRASKA WILL LIFT NORTHEAST INTO IOWA BEFORE PIVOTING TO THE
NORTHWEST IN RESPONSE TO THE UPPER LEVEL FEATURES. THIS WILL MOVE A
WARM FRONT ACROSS THE FORECAST AREA THROUGH TONIGHT. STRONG THETA-E
ADVECTION OCCURS THIS AFTERNOON AND EVENING ALONG THIS BOUNDARY AND
STORMS SHOULD DEVELOP THIS AFTERNOON ACROSS EASTERN AND SOUTHERN
IOWA. SOME STORMS COULD BE STRONG IN THE VICINITY OF THE BOUNDARY
BUT THE BETTER INSTABILITY WILL BE FURTHER SOUTH. STILL...CANT RULE
OUT AN ISOLATED SEVERE STORM ACROSS THE SOUTHEAST. TO ADD TO THE
MIX...THIS EVENING AS THE SURFACE LOW PIVOTS BACK TO THE NORTHWEST
IT WILL MOVE A COLD FRONT THROUGH THE FORECAST AREA PROVIDING YET
ANOTHER BOUNDARY FOR ADDITIONAL THUNDERSTORM CHANCES THIS EVENING.
THE FRONT WILL SHIFT EAST OF THE FORECAST AREA AND THE DRY SLOT
PIVOTS INTO CENTRAL IOWA SOMETIME AROUND 06Z OR SHORTLY THEREAFTER
THUS PRECIP/THUNDERSTORM CHANCES WILL END BETWEEN 06Z AND 09Z.
COLDER AIR WILL THEN MOVE IN BEHIND THIS SYSTEM BUT TEMPERATURES
WILL HAVE QUITE A RANGE TONIGHT AS THE COLD AIR WILL NOT MAKE IT ALL
THE WAY ACROSS THE STATE. LOOKING FOR LOWS IN THE UPPER 20S
NORTHWEST TO THE MID 40S SOUTHEAST.
WE SHOULD DRY OUT SOME ON MONDAY BUT IT WILL BE PRETTY COOL WITH
HIGHS ONLY IN THE 40S AND 50S. A LARGE TROUGH WILL DEEPEN OVER THE
WEST COAST KEEPING THE CENTRAL CONUS IN A BROAD SOUTHWEST FLOW.
SEVERAL SHORTWAVES WILL EJECT OUT OF THE TROUGH BEFORE THE TROUGH
SHIFTS EAST LATER IN THE WEEK. THIS WILL KEEP PERIODIC CHANCES FOR
RAIN OF SNOW OVER CENTRAL IOWA THROUGH THE FORECAST PERIOD. BY
TUESDAY NIGHT AND WEDNESDAY THE TROUGH DEEPENS SUFFICIENTLY TO BRING
WARM ADVECTION BACK INTO IOWA AND MOISTURE AS WELL IN A SOUTHERLY
FLOW. SHOWERS AND THUNDERSTORMS WILL BE BACK IN THE FORECAST DURING
THIS TIMEFRAME. THE TROUGH IS STILL EXPECTED TO SHIFT EAST THROUGH
THURSDAY NIGHT KEEPING THE MID WEEK WET. PRECIP WILL CHANGE TO OR
MIX WITH SNOW WEDNESDAY NIGHT AND THURSDAY NIGHT BUT TEMPS SHOULD BE
WARM ENOUGH THROUGH THE DAY FOR RAIN WITH THE EXCEPTION OF THE FAR
NORTHWEST. WE GET A BIT OF A BREAK ON FRIDAY NIGHT FROM THE PRECIP
BUT AS AN UPPER LEVEL RIDGE BUILDS OVER THE ROCKIES ANOTHER SHORT
WAVE MAKES ITS WAY INTO THE MIDWEST FOR SATURDAY BRINGING AT LEAST
SMALL CHANCES FOR RAIN YET AGAIN. UNFORTUNATELY THIS PERIOD WILL BE
MARKED BY WELL BELOW NORMAL TEMPS AS WELL.
&&
.AVIATION...14/18Z
ISSUED AT 1249 PM CDT SUN APR 14 2013
WARM FRONT LIFTING NORTH AND HAS REACHED I-80 NOW. SCATTERED
SHOWERS CONTINUE OVER PARTS OF EASTERN IA IN THE WAA AREA BUD DO
NOT EXPECT TO SEE WIDESPREAD RESTRICTIONS WITH THESE. SOME VFR AND
LOCAL IFR CONDITIONS IN THE KMCW AND KALO AREAS EARLY THIS
AFTERNOON. COLD FRONT WILL MOVE ACROSS THE STATE LATE THIS
AFTERNOON AND EVENING WITH A POTENTIAL BROKEN TO SOLID SQUALL LIKE
DEVELOPING ALONG THE FRONT. THIS SHOULD EXIT THE TAF SITES BY 06Z.
SOME MVFR CIGS POST FROPA OVER THE NRN PART OF THE STATE...BUT
REMAINING VFR IN THE SOUTH.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR ADAMS-APPANOOSE-
CLARKE-DAVIS-DECATUR-LUCAS-MADISON-MAHASKA-MARION-MONROE-
RINGGOLD-TAYLOR-UNION-WAPELLO-WARREN-WAYNE.
&&
$$
UPDATE...MS APR 13
SHORT TERM...MS APR 13
LONG TERM...FAB
AVIATION...MS APR 13
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
147 PM EDT SUN APR 14 2013
.SYNOPSIS...
ISSUED AT 337 AM EDT SUN APR 14 2013
WARMER AIR MAKING A SURGE TOWARD THE AREA THIS MORNING AND EARLY
AFTERNOON WILL TOUCH OFF SOME PRECIPITATION ACROSS THE AREA. THIS
PRECIPITATION COULD START OFF AS RAIN...SNOW...AND EVEN A SLIGHT
CHANCE OF SLEET. THIS WILL MOVE NORTH OF THE AREA BY THIS EVENING.
WARMER AIR WILL SPREAD ACROSS THE AREA THROUGH THE DAY ON MONDAY.
A COLD FRONT WILL GRADUALLY MOVE THROUGH THE AREA DURING THE DAY ON
MONDAY. THE THREAT FOR SHOWERS WITH A FEW STORMS WILL INCREASE LATER
TONIGHT AND CONTINUE THROUGH MONDAY. OCCASIONAL PERIODS OF RAIN WILL
BE POSSIBLE THEN MID TO LATE WEEK THIS WEEK. WARMER AIR WILL
TEMPORARILY MOVE IN BEFORE COLDER AIR MOVES IN NEXT WEEKEND.
&&
.UPDATE...
ISSUED AT 838 AM EDT SUN APR 14 2013
SINCE IT WAS SNOWING WITH VISIBILITIES UNDER 2 MILES AS I DROVE
FROM GRANDVILLE TO M6 AND US-131 AND HOLLAND HAD 3SM -SN AND SINCE
THIS BAND IS MOVING NORTHEAST WITH THE WARM FRONT AND SINCE THE
LATEST HRRR (10Z) SHOWS THIS BAND DEVELOPING AS IT MOVES NORTH I
UPDATED THE FORECAST GRIDS TO SHOW A BAND PRECIPITATION MOVING
NORTH WITH TIME WITH LIKELY TO CONDITIONAL POPS. I USED THE TOP
DOWN METHOD TO CREATE THE PRECIPITATION TYPES SO WE NOW HAVE SNOW
TO RAIN AND SLEET IN THE GRIDS. BY EARLY AFTERNOON THE SOUTH EDGE
SHOULD BE NEAR ROUTE 10 AND BY THEN IT SHOULD BE ALL RAIN. I DO
NOT SEE ANY SIGNIFICANT ACCUMULATION WITH THIS AS IT WILL BE TO
SHORT LIVED.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 337 AM EDT SUN APR 14 2013
THE MAIN CHALLENGES WITH THE SHORT TERM PORTION OF THE FCST INVOLVE
THE CHC OF PCPN TODAY ALONG WITH P-TYPE...AND THEN PCPN CHCS THE
REMAINDER OF THE PERIOD THROUGH TUE. ONE CHANGE IN THE FCST IS TO
LOWER PCPN CHANCES FOR TUE.
THE CLOUDS THAT WERE ASSOCIATED WITH THE BIG AND PERSISTENT LOW
AFFECTING THE AREA OVER THE PAST FEW DAYS HAVE BROKEN UP OVER THE
PAST COUPLE OF HOURS. THIS IS OCCURRING AS THE UPPER FLOW HAS BECOME
ANTI-CYCLONIC AND SFC RIDGING IS MOVING IN. THE NEXT BATCH OF CLOUDS
HAVE ALREADY STARTED TO MOVE IN ACROSS THE SW CORNER OF THE CWFA.
THE INCOMING CLOUDS ARE ASSOCIATED WITH RETURN FLOW IN THE MID
LEVELS ALREADY SETTING UP TO OUR SW THIS MORNING. JUST NORTH OF THE
DEVELOPING WARM FRONT FROM THE CENTRAL PLAINS TO THE MID MS RIVER
VALLEY IS A NARROW BAND OF SHOWERS AND ISOLATED STORMS. THIS BAND
WILL BE MAKING A RUN AT THE CWFA THIS MORNING. THE BEST LLJ AND
SURGE OF MOISTURE WILL TAKE PLACE WEST OF THE STATE. WE WILL NOT SEE
A WHOLE LOT OF MOISTURE BELOW 5K FEET...WHICH WILL HELP TO EAT AWAY
SOME OF THE PCPN THAT TRIES TO MOVE IN.
P-TYPE IS SOMEWHAT OF AN ISSUE WITH THIS PCPN. FCST SOUNDINGS
INDICATE THAT ALMOST THE ENTIRE CWFA IS COLD ENOUGH FOR SNOW. AS THE
WARM AIR SURGES IN...WE EXPECT TO SEE THE LEADING EDGE OF PCPN
INITIALLY START OUT AS SOME LIGHT SNOW. THERE COULD BE A BRIEF
PERIOD OF SOME SLEET AS FCST SOUNDINGS INDICATE AN ABOVE FREEZING
LAYER AT THE SFC AND ALOFT TRAPPING A COLD LAYER AROUND 2K FEET OR
SO THIS MORNING ACROSS THE SOUTH. THIS DOES NOT EXIST UP NORTH WHERE
THE PCPN WILL ARRIVE AFTER THE ELEVATED FREEZING LAYER MIXES OUT. AS
THE WARMER AIR GETS HERE...PCPN WILL CHANGE OVER TO RAIN BEFORE
ENDING.
WE WILL SEE A BREAK IN THE WEATHER THEN FROM LATE THIS AFTERNOON
UNTIL LATER TONIGHT. AT THAT TIME...WE WILL SEE THE LLJ AXIS MOVE IN
OUT AHEAD OF THE COLD FRONT THAT WILL BE APPROACHING THE AREA LATE.
THE MOISTURE TRANSPORT INTO THE AREA AND FRONT MOVING THROUGH WILL
BE SUFFICIENT FOR SPREADING SHOWERS IN FROM THE WEST THROUGH MON
MORNING. FCST SOUNDINGS INDICATE THAT SUFFICIENT ELEVATED
INSTABILITY WILL EXIST ENOUGH TO JUSTIFY A SLIGHT CHC OF THUNDER.
THE FRONT SHOULD CLEAR THE CWFA TO THE SE MON EVENING. PCPN CHCS
WILL DIMINISH MON NIGHT AS THE FRONT SINKS SOUTH INTO INDIANA AND
OHIO. IT WILL BE STALLING OUT AS IT WILL ALIGN WITH THE UPPER FLOW.
THE TREND IN THE MODELS IS FOR IT TO SINK A LITTLE FURTHER SOUTH
WITH A SLIGHTLY BETTER PUSH FROM THE WAVE MOVING THROUGH ONTARIO.
THIS SHOULD PROVIDE FOR A LITTLE LESS RAINFALL POTENTIAL ON TUE.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 337 AM EDT SUN APR 14 2013
GOOD MODEL CONSENSUS CONTINUES WITH THE 00Z GUIDANCE. MAIN IMPACT IN
THE EXTENDED IS MORE RAIN WHICH COULD CONTINUE SOME FLOODING INTO
NEXT WEEKEND. THE COLD FRONT STALLS ALONG OR JUST SOUTH OF THE
SOUTHERN FORECAST AREA WITH STORMS FIRING UP ALONG IT TUESDAY NIGHT.
THEN IT LIFTS NORTH AS A WARM FRONT WEDNESDAY AS ANOTHER SHORTWAVE
TROUGH APPROACHES. SFC LOW ARRIVES WEDNESDAY NIGHT ALONG WITH
HEAVIER RAIN AND SOME THUNDERSTORMS WITH POSSIBLY ANOTHER INCH OR
TWO OF RAIN BY THURSDAY.
COLDER WEATHER ON THE BACKSIDE OF THE LOW FOR THE END OF THE WEEK
WITH A FEW LEFT OVER RAIN AND SNOW SHOWERS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 147 PM EDT SUN APR 14 2013
A NARROW BAND OF RAIN AND SNOW HAS MOVED OUT OF THE TAF SITES
EARLY THIS AFTERNOON. VFR CONDITIONS PREVAIL BEHIND THIS PCPN AND
THESE CONDITIONS ARE EXPECTED TO BE MAINTAINED FOR THE REST OF THE
AFTERNOON AND THROUGH MUCH OF THE OVERNIGHT. SE WINDS WILL REMAIN
BRISK AROUND 10-15 KTS INTO TONIGHT.
ANOTHER PERIOD OF RAIN WILL ARRIVE TOWARD DAYBREAK MONDAY. EXPECT
CONDITIONS TO LOWER TO MVFR AROUND DAYBREAK AND PERSIST THROUGHOUT
THE MORNING AND INTO MID DAY. WINDS WILL BECOME MORE SOUTHERLY AND
INCREASE TO 15 TO 20 KTS TOWARD MID DAY.
THERE IS THE CHANCE OF EMBEDDED THUNDERSTORMS AS THE RAIN ARRIVES
MONDAY MORNING. HOWEVER THESE LOOKS TO BE TOO ISOLATED TO INCLUDE
IN THE TAFS AT THIS POINT.
&&
.MARINE...
ISSUED AT 337 AM EDT SUN APR 14 2013
WE WILL BE ISSUING A SMALL CRAFT ADVISORY FOR THE ENTIRE NEARSHORE
WITH THIS FCST PACKAGE. STRONGER GRADIENT WILL MOVE IN LATER THIS
AFTERNOON AS THE WARM FRONT MOVES THROUGH THE AREA. THESE WINDS WILL
REMAIN UP UNTIL AND JUST AFTER THE FRONT MOVES THROUGH MON
AFTERNOON. WAVES WILL NOT BE A BIG PROBLEM INITIALLY AS THE WIND
WILL BE OFFSHORE. WINDS WILL EVENTUALLY SHIFT TO THE SOUTH/SOUTHWEST
AND WAVES WILL BUILD SOME AT THAT POINT.
&&
.HYDROLOGY...
ISSUED AT 337 AM EDT SUN APR 14 2013
NUMEROUS RIVER ADVISORIES AND WARNINGS REMAIN IN EFFECT...AND WILL
CONTINUE INTO THIS COMING WEEK. IT APPEARS THAT THE CREST ON THE
GRAND RIVER IS NEAR ADA AND WILL CONTINUE DOWNSTREAM OVER THE NEXT
FEW DAYS.
THE MAIN HYDRO CONCERN IN THE FCST IS THE ADDITIONAL RAINFALL
EXPECTED THIS WEEK AS WE WILL ONCE AGAIN BE AFFECTED BY AN UNSETTLED
AND WET PATTERN. THE AREA COULD BE LOOKING AT ANOTHER COUPLE OF
INCHES OF RAINFALL OVER THE NEXT WEEK WHICH WOULD ONLY EXACERBATE
ANY PROBLEMS THAT WILL REMAIN AS THE RAIN ARRIVES. THE POSITIVE SIDE
TO THIS COMING WEEK IS THAT FCST RAINFALL AMOUNTS IN GENERAL HAVE
DIMINISHED A LITTLE BIT. STILL A BIT OF UNCERTAINTY AS TO EXACTLY
HOW MUCH RAIN WE WILL SEE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR LMZ844>849.
&&
$$
UPDATE...WDM
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...OSTUNO
AVIATION...JK
HYDROLOGY...NJJ
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS DULUTH MN
308 PM CDT SUN APR 14 2013
.SHORT TERM.../NOW - MONDAY/
THE FOCUS REMAINS THE WINTRY STORM SYSTEM THAT IS BEGINNING TO
MOVE INTO THE SOUTHERN FORECAST AREA. OVERALL...THIS SYSTEM HAS
BEEN DIFFICULT TO FORECAST FOR DUE TO DELAYS IN WHICH THE PCPN
FORMS AND MOVES INTO THE FORECAST AREA...CONSIDERABLE MODEL
DIFFERENCES IN SNOWFALL AMOUNTS...AND PCPN TYPE ISSUES FOR
NW WISCONSIN AND EAST CENTRAL MINNESOTA. THROUGH THE COURSE OF
THIS SHIFT...I HAVE ATTEMPTED TO DELAY THE ONSET OF THE PCPN AND
COMMUNICATE THE DELAY VIA THE GRAPHIC WEATHER STORY AND ON
FACEBOOK. THE MODELS SUGGEST THAT THE PCPN WILL INCREASE IN ITS
NORTHWARD SPEED LATER THIS AFTERNOON...SO I THINK WE MAY HAVE
FINALLY GOTTEN CLOSER TO BETTER DETERMINING TIMING. I EXTENDED
SOME ADVISORIES INTO EARLY THIS EVENING BASED ON THE PCPN DELAY
AND TO ALLOW THE EVENING SHIFT FORECASTER TIME TO SEE HOW THINGS
PAN OUT. I ALSO NOW THINK SOME AREAS OF NORTHERN MINNESOTA COULD
GET ANOTHER INCH OR TWO OF MORE SNOW THAN PREVIOUSLY
THOUGHT...SUCH AS ALONG THE NORTH SHORE.
THROUGH TONIGHT...A POTENT MID/UPPER LEVEL LOW IN THE NORTHERN
HIGH PLAINS AND ITS ASSOCIATED SURFACE LOW IN THE CENTRAL PLAINS
(EASTERN NEBRASKA AND WESTERN IOWA) WILL LIFT INTO MINNESOTA
TONIGHT. THE PCPN EXPECTED WITH THIS SYSTEM IS MOVING NORTHWARD
FROM EAST CENTRAL MINNESOTA AND WEST CENTRAL WISCONSIN AND ALREADY
BEGINNING TO MOVE INTO NORTHEAST MINNESOTA AND NORTHWEST
WISCONSIN. THE PCPN IS EXPECTED TO SPREAD ACROSS THE REST OF THE
NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN THROUGH THE REST OF
THE AFTERNOON AND INTO THIS EVENING. THE MODELS SUGGEST THE
INITIAL BAND OF PCPN WILL COME DOWN AS SNOW AND MAY COME DOWN
QUITE FAST...WITH LIKELY SNOW RATES OF UP TO 1 TO 2 INCHES PER
HOUR IF NOT MORE. RECENT HRRR MODEL RUNS HAVE SHOWN SOME PERIODS
LATER THIS AFTERNOON OF 2 TO 3 INCHES PER HOUR. THERE IS STRONG
FRONTOGENESIS WITH THIS INITIAL BAND...SO IT IS CERTAINLY
POSSIBLE. CONSIDERING THE RELATIVELY WARM TEMPERATURES ACROSS THE
FORECAST AREA...MID 30S TO LOW 40S...THE PCPN MAY BRIEFLY BEGIN AS
A LIGHT RAIN BEFORE SWITCHING OVER TO SNOW ONCE THE RATES INCREASE
AND THE COLUMN COOLS. THERE WILL ALSO LIKELY BE A TRANSITION TO
SLEET AND RAIN ACROSS MUCH OF NORTHWEST WISCONSIN LATE THIS
AFTERNOON AND THIS EVENING. MUCH OF NORTHEAST MINNESOTA SHOULD GET
ABOUT 4 TO 9 INCHES OF SNOW...WITH THE GREATEST TOTALS ACROSS FAR
NORTHERN MINNESOTA. SOME AREAS MAY GET UP TO 10 INCHES...SUCH AS
ALONG THE NORTH SHORE OF LAKE SUPERIOR. I EXPECT LESS AMOUNTS OF
SNOW ACROSS NORTHWEST WISCONSIN AND EAST CENTRAL MINNESOTA BECAUSE
OF THE SLEET AND RAIN. HOWEVER...I WOULD NOT BE SURPRISED IF SOME
AREAS SEE CONSIDERABLE ACCUMULATION OF SLEET...WHICH IS WHY I
INCLUDED THE ACCUMULATION IN THE SNOW TOTALS I PROVIDED IN THE
WINTER WEATHER ADVISORIES FOR NORTHWEST WISCONSIN. STRONG EAST
WINDS ARE DEVELOPING ACROSS THE FORECAST AREA THIS AFTERNOON...AND
THEY SHOULD CONTINUE TO STRENGTHEN INTO THIS EVENING. THE WINDS
WILL BE STRONGEST NEAR LAKE SUPERIOR...ESPECIALLY NEAR THE TWIN
PORTS. THE 15 TO 30 MPH WINDS WITH GUSTS UP TO 40 MPH NEAR LAKE
SUPERIOR COULD REALLY REDUCE VISIBILITY DURING THE HEAVIER SNOW
BANDS AND CAUSE BRIEF NEAR WHITE-OUT CONDITIONS.
MONDAY...THE SNOW WILL LIKELY CONTINUE ACROSS MOST OF THE FORECAST
AREA THROUGH AT LEAST THE EARLY AFTERNOON AS THE LOW LIFTS INTO
ONTARIO. UP TO ADDITIONAL 1 TO 3 INCHES OF SNOW COULD FALL ACROSS
THE NORTHERN FORECAST AREA DURING THE DAY. THE WINTER STORM
WARNING FOR THE NORTHERN FORECAST AREA RUNS THROUGH 15Z TOMORROW
MORNING...BUT WE MIGHT NEED TO EXTEND THE WARNING INTO SUNDAY
AFTERNOON IF THE SNOW AND REDUCED VISIBILITY ARE STILL LINGERING.
GUSTY SOUTH TO SOUTHWEST WINDS WILL DEVELOP IN THE WAKE OF THE
PASSING LOW PRESSURE SYSTEM. TEMPERATURES SHOULD BE IN THE UPPER
30S TO LOW 40S.
.LONG TERM.../MONDAY NIGHT - SATURDAY/
THE UPPER LOW WILL BE OVER THE NORTHERN MINNESOTA/NORTHERN LAKE
SUPERIOR AREA 00Z TUESDAY THEN CONTINUE E/NE MONDAY NIGHT. A BAGGY
UPPER TROUGH...WITH AN EXTENSION TO THE SURFACE WILL REMAIN OVER
THE CWA INTO MONDAY NIGHT. WE KEPT A CHANCE FOR SNOW OVER MUCH OF
OUR NORTHEAST MINNESOTA ZONES MONDAY NIGHT...WITH THE BEST CHANCE
OVER THE BORDER REGION.
AN UPPER RIDGE WILL BUILD OVER THE REGION BRIEFLY TUESDAY...WITH
MOST AREAS DRY INTO TUESDAY NIGHT.
A DEEP TROUGH WILL THEN MOVE OVER THE ROCKIES TUESDAY
NIGHT...MOVING SLOWLY EAST THROUGH THE WEEK AFFECTING THE
NORTHLAND. ANOTHER SPRING STORM IS POISED TO AFFECT THE NORTHLAND
WEDNESDAY INTO AT LEAST THURSDAY...POSSIBLY LINGERING A BIT
LONGER. BOTH THE GFS AND ECMWF ARE IN GENERAL AGREEMENT WITH THE
TRACK OF THE SURFACE LOW...TAKING IT FROM THE TEXAS PANHANDLE AT
12Z WEDNESDAY TO LAKE MICHIGAN/SOUTHEAST WISCONSIN BY 12Z
THURSDAY...THEN IT CONTINUES NORTHEAST. AS IS THE CASE WITH THESE
SPRING STORMS...THE THERMAL PROFILES WILL BE CRITICAL TO PRECIP
TYPE. IT DOES APPEAR TEMPERATURES WILL BE WARM ENOUGH FOR A MIX
OVER AT LEAST NORTHWEST WISCONSIN. WE HAVE A RAIN/SNOW MIX OVER
NORTHWEST WISCONSIN WEDNESDAY NIGHT/THURSDAY...AND WILL LIKELY
NEED TO ADJUST THAT AS THIS SYSTEM NEARS. THE THREAT FOR MORE
ACCUMULATING SNOW IS INCREASING OVER NORTHEAST MINNESOTA INTO FAR
NORTHWEST WISCONSIN WEDNESDAY INTO THURSDAY. IT`S VERY DIFFICULT
TO TRY AND PLACE A NUMBER ON SNOW ACCUMULATION AT THIS POINT WITH
SO MUCH UNCERTAINTY REVOLVING THE PRECIP TYPE...BUT AT LEAST
SEVERAL INCHES OF SNOW WILL FALL OVER EASTERN MINNESOTA/FAR
NORTHWEST WISCONSIN FROM THIS SYSTEM. THE FORECAST MID-LATE WEEK
IS WORTH MONITORING CLOSELY AS THE PROBABILITY IT WILL HAVE A
SIGNIFICANT IMPACT ON THE NORTHLAND/S WEATHER IS INCREASING. MORE
DETAIL REGARDING PRECIP TYPE/AMOUNTS WILL BE ADDED AS WE PROGRESS
INTO THE EARLY PART OF THE WEEK.
AS THE UPPER TROUGH PASSES LATE IN THE WEEK...A SURFACE HIGH WILL
MOVE OVER THE AREA DRYING THINGS OUT FOR A TIME LATE IN THE
WEEK/EARLY WEEKEND. ANOTHER SHORTWAVE WILL BRING ANOTHER CHANCE
FOR MIXED PRECIP SATURDAY NIGHT/SUNDAY BUT THIS SYSTEM DOES NOT
LOOK TO BE PARTICULARLY STRONG.
TEMPERATURES THROUGH MOST OF THE PERIOD WILL REMAIN BELOW NORMAL.
&&
.AVIATION.../18Z TAFS/
AREA RADARS SHOWED PRECIPITATION WAS MOVING NORTH THROUGH
MINNESOTA/WISCONSIN...AND WAS BECOMING MORE WIDESPREAD. THE NAM
HAS A PRETTY GOOD HANDLE ON THIS...AS DO THE HIGH RES MODELS. WE
EXPECT THE PRECIPITATION TO BEGIN AS SNOW ALL AREAS...THEN IT MAY
BECOME A WINTRY MIX AT KHYR...AND POSSIBLY AT KBRD BRIEFLY. TIMING
IN THE TAFS MAY NEED TO BE ADJUSTED BY AN HOUR OR SO...AND WE`LL
DO THAT AS CONFIDENCE INCREASES FOR AN EXACT STARTING TIME.
VSBYS WILL DROP TO IFR OR LIFR WITHIN AN HOUR OF PRECIP
ONSET...AND AREAS AROUND LAKE SUPERIOR WILL SEE WINDY CONDITIONS
FURTHER REDUCING THE VSBY IN BLOWING SNOW. A DRY SLOT WILL WORK
NORTH LATER THIS EVENING/TONIGHT AND CAUSE THE PRECIP TO DIMINISH
OVER MOST OF THE TAFS. FORECAST SOUNDINGS SHOW TOP DOWN
DRYING...SO SOME SPOTTY DRIZZLE OR FREEZING DRIZZLE IS NOT OUT OF
THE QUESTION. WE DID NOT ADD THAT TO THE TAFS AT THIS TIME...AS
THAT IS MORE OF A SHORT TERM FORECAST ISSUE AND CAN BE ADDRESSED
WITH LATER UPDATES.
WINDS WILL SWITCH FROM EASTERLY TO SOUTHERLY LAT TONIGHT/MONDAY
MORNING...THEN BECOME SOUTHWEST.
&&
.POINT TEMPS/POPS...
DLH 28 38 30 38 / 100 70 20 10
INL 28 38 26 36 / 100 90 50 20
BRD 29 39 29 38 / 90 70 10 10
HYR 32 41 30 42 / 100 40 10 10
ASX 31 42 31 41 / 100 40 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WARNING UNTIL 7 AM CDT MONDAY FOR MNZ025-026-
033>035-037.
WINTER WEATHER ADVISORY UNTIL 1 AM CDT MONDAY FOR MNZ036-038.
WINTER STORM WARNING UNTIL 10 AM CDT MONDAY FOR MNZ010>012-
018>021.
WI...WINTER WEATHER ADVISORY UNTIL 7 PM CDT THIS EVENING FOR WIZ003-
004-006>009.
WINTER WEATHER ADVISORY UNTIL 7 AM CDT MONDAY FOR WIZ001-002.
LS...GALE WARNING UNTIL 3 AM CDT MONDAY FOR LSZ121-140>148.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM....MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS JACKSON MS
245 PM CDT SUN APR 14 2013
.SHORT TERM...TONIGHT THROUGH EARLY WEDNESDAY...
THE PRIMARY CONCERNS IS THE DENSE FOG POTENTIAL FOR
TONIGHT...AREAS OF FOG FOR LATE MONDAY NIGHT INTO EARLY
TUESDAY...FOLLOWED BY THE LAST OF THE ISOLATED CONVECTION LEAVING THE REGION
BY THIS EVENING. THE LAST CONCERNS ARE PATCHY FOG WEDNESDAY MORNING
AND POPS AND TEMPS.
LATEST SATELLITE IMAGERY SHOWED A SHORTWAVE TROUGH MOVING EAST OVER
THE ARKLAMISS TO THE NORTHERN GULF OF MEXICO. THE SURFACE FRONT WAS
SOUTH OF THE REGION. THE BEST UPPER DIVERGENCE HAS MOVED EAST OF THE
REGION ALONG WITH STRONG MOISTURE TRANSPORT...WHICH TIES WITH THE
RAINS MOVING EAST OF THE FORECAST AREA. HRRR AND LOCAL WRF STILL
SHOWS SOME POTENTIAL FOR SOME ISOLATED CONVECTIVE DEVELOPMENT FOR
THIS AFTERNOON BEFORE EXITING BY THIS EVENING. SO HAVE ISOLATED POPS
FROM WEST TO EAST FOR THE PREFIRST PERIOD. THE PRESSURE GRADIENT
HAS RELAXED IN THE EAST AS BREEZY CONDITIONS HAVE DECREASED IN THE
EAST.
FOR TONIGHT AND MONDAY...THE RAINS WILL HAVE EXITED THE REGION...BUT
WITH THE DAMP GROUND...LIGHT WINDS...AND FAIR SKIES. DENSE FOG WILL BE
LIKELY. THIS WAS SHOWN BY SREF PROBS OF 90-100 PERCENT...MODEL
SOUNDINGS AND MODEL CROSS SECTIONS. EXPECT AREAS OF DENSE FOG TO
DEVELOP AFTER MIDNIGHT. THIS WILL PROBABLY PROMPT THE NEED FOR A
DENSE FOG ADVISORY. WILL LET THE EVENING SHIFT DECIDE WHERE TO PUT
IT...IF THEY DECIDE TO DO IT. TRAVELERS SHOULD BE CAUTIOUS IN DENSE
FOG AREAS. MEANWHILE A WEAK WARM FRONT WILL PUSH NORTH OVER THE
REGION DURING THE NIGHT HELPING THE FOG ALONG AS THE REGION WILL BE
UNDER A FLAT UPPER RIDGING. LOWS TONIGHT WILL RANGE FROM THE MIDDLE
50S NORTHEAST TO THE LOWER 60S SOUTH. WENT CLOSE TO MAV GUIDANCE. AS
WE GO INTO MONDAY MORNING THE AREAS OF DENSE FOG SHOULD LIFT BY MID
MORNING. THE UPPER RIDGE WILL AMPLIFY EAST OF THE REGION PUTTING US
UNDER SOUTHWEST FLOW ALOFT. THIS WILL ALLOW WARM ADVECTION IN THE
LOW LEVELS FOR ABOVE NORMAL HIGH TEMPERATURES. AFTERNOON HIGHS WILL
RANGE FROM THE LOWER TO MIDDLE 80S. WENT CLOSE TO MAV GUIDANCE.
FOR MONDAY NIGHT AND TUESDAY...ONCE AGAIN CONDITIONS WILL FAVOR
ANOTHER ROUND OF FOG. SREF PROBS WILL BE HIGH. MODEL CROSS SECTIONS
AND AREAS MODEL SOUNDING FAVOR THOSE CONDITIONS. SO HAVE PUT IN
AREAS OF FOG FOR MONDAY NIGHT INTO MID MORNING TUESDAY. MEANWHILE AN UPPER
TROUGH WILL BE EVOLVING OVER THE WESTERN US...WHICH WILL BE OUR
STORM SYSTEM FOR THURSDAY. LOWS WILL BE MAINLY IN THE 60S. FOR TUESDAY
SOME GUIDANCE TRIES TO SQUEEZE OUT SOME LOW POPS DURING THE DAY. BUT
MODEL SOUNDINGS LOOK RATHER CAPPED FOR THE DAY. IT MAY BE ABLE TO
SQUEEZE OUT SOME HIT OR MISS LIGHT SPOTTY SHOWERS IF IT CAN GET BY
THE CAP. BUT IM MORE FOR KEEPING IT DRY FOR THE DAY. HIGHS ONCE
AGAIN WILL BE ABOVE NORMAL WITH READINGS IN THE LOWER TO MIDDLE 80S.
FOR TUESDAY NIGHT INTO EARLY WEDNESDAY...ONCE AGAIN MODEL PROGS
FAVOR FOR SOME KIND OF FOG DEVELOPMENT. USUALLY DO NOT PUT IN FOG
FOR THIS FAR OUT...BUT SREF PROBS ARE PAINTING AROUND 60 TO 85
PERCENT. SO PUT IN PATCHY FOG FOR LATE TUESDAY NIGHT UNTIL MID WEDNESDAY
MORNING. MEANWHILE THE UPPER TROUGH WILL BE EVOLVING OVER THE
ROCKIES. LOWS FOR TUESDAY NIGHT WILL BE IN THE 60S. WENT CLOSE TO A
BLEND OF GMOS AND MAV GUIDANCE./17/
.LONG TERM...WEDNESDAY THROUGH SUNDAY...
NOT MUCH CHANGE IN THE EXTENDED PORTION OF THE FORECAST. RATHER
STOUT SUBTROPICAL RIDGING WILL BE IN PLACE OVER THE SOUTHEASTERN
CONUS WEDNESDAY IN ADVANCE OF A DEEP TROUGH TAKING SHAPE OVER
THE WESTERN HALF OF THE COUNTRY. STRONG SURFACE HIGH PRESSURE OVER
THE SOUTHEAST WILL CONTINUE TO PULL WARM/MOIST GULF AIR ACROSS THE
ARKLAMISS THROUGH EARLY THURSDAY BEFORE A COLD FRONT ASSOCIATED WITH
THE AFOREMENTIONED LOW PRESSURE SYSTEM SWINGS ACROSS THE REGION.
TEMPERATURES TUE/WED ARE GOING TO BE WELL ABOVE NORMAL FOR MID APRIL
WITH HIGHS CLIMBING INTO THE MID 80S.
THINGS WILL CHANGE HEADED INTO THURSDAY AS THE COLD FRONT APPROACHES
THE REGION. CLOUD COVER WILL HELP KEEP TEMPS A TAD COOLER ALTHOUGH
HIGHS IN THE UPPER 70S/LOWERS 80S ARE STILL EXPECTED (WARMEST ACROSS
THE EAST). THE MODELS CONTINUE TO DANCE AROUND WITH FRONTAL TIMING
BUT REMAIN FOCUSED IN THE THURSDAY AFTERNOON/THURSDAY EVENING
TIMEFRAME. THE ANTECEDENT WARM/MOIST ATMOSPHERE THAT WILL BE IN
PLACE AHEAD OF THE FRONT SHOULD SET THE STAGE FOR SEVERE WEATHER
POTENTIAL AS THE FRONT PASSES...BUT EXACT DETAILS WITH RESPECT TO
COVERAGE/INTENSITY REMAIN UNCERTAIN THIS FAR IN ADVANCE. SURFACE DEW
POINTS LOOK TO BE IN THE UPPER 60S/NEAR 70 BY THURSDAY AFTERNOON...
AND COUPLED WITH STEEP MID LEVEL LAPSE RATES SHOULD BE SUFFICIENT
FOR SBCAPE VALUES NEAR/IN EXCESS OF 1500J/KG ACROSS AREAS AHEAD OF
THE FRONT. BEST HEIGHT FALLS/SHEAR LOOKS LIKE IT MAY BE CONFINED
ACROSS AREAS FURTHER NORTH THAN SOUTH...BUT WON`T TRY TO GET TOO
SPECIFIC AT THIS POINT. WILL KEEP A MENTION OF SEVERE WEATHER
POTENTIAL IN THE HWO/GRAPHICS FOR THU AFTN/EVE.
UPDATE...THE 12Z RUNS OF THE GFS AND EURO STILL FAVOR THURSDAY TIME
FRAME FOR SEVERE WEATHER CHANCES.
MUCH COOLER WEATHER CAN BE EXPECTED IN WAKE OF THE FRONT AS A 1025MB
HIGH PRESSURE CENTER BUILDS OVER THE MS VALLEY. TEMPS WILL LIKELY
FALL BACK BELOW NORMAL FRI THROUGH THE WEEKEND...ALONG WITH CLEAR
SKIES. AS FOR TEMPS/POPS...I DID CONTINUE THE TREND OF TRIMMING AFTN
POPS TUESDAY AS A STRONG CAP ACROSS THE REGION KEEPS THINGS IN CHECK.
WITH THAT SAID...WOULDN`T BE TOTALLY SURPRISED TO SEE A SHOWER OR
THUNDERSTORM EACH AFTN/NOTHING SIGNIFICANT. TEMPS LOOKED GOOD UNTIL
THE FRONT PASSES WHERE COOLER HIGHS/LOWS OFFERED BY THE EURO MOS FOR
THE WEEKEND SEEMED A BIT MORE REASONABLE. /BK/17/
&&
.AVIATION...AREAS OF MVFR CIGS WILL CONTINUE THIS AFTERNOON INTO THE
EVENING HOURS. CONDITIONS WILL DETERIORATE TONIGHT WITH WIDESPREAD
IFR/LIFR CIGS/VSBYS DEVELOPING BY MIDNIGHT WHEN FOG/LOW STRATUS
FORMATION IS EXPECTED. IFR/LIFR FOG/STRATUS WILL MIX OUT MID MONDAY
MORNING...LEAVING MVFR TO VFR CIGS FOR MONDAY AFTERNOON./03/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 60 84 68 85 / 4 5 10 14
MERIDIAN 59 84 67 84 / 4 5 10 14
VICKSBURG 60 85 66 85 / 5 6 11 14
HATTIESBURG 60 85 66 85 / 4 8 11 14
NATCHEZ 61 84 68 84 / 3 8 10 14
GREENVILLE 61 83 66 85 / 6 10 12 14
GREENWOOD 61 84 67 84 / 4 5 12 14
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
17/03/BK
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1205 PM CDT SUN APR 14 2013
.UPDATE...LATEST SATELLITE IMAGERY SHOWED A SHORTWAVE TROUGH MOVING
EAST OVER THE ARKLAMISS TO THE NORTHERN GULF OF MEXICO. THE SURFACE
FRONT WAS OFFSHORE. THE BEST UPPER DIVERGENCE HAS MOVED EAST OF THE REGION
ALONG WITH STRONG MOISTURE TRANSPORT...WHICH TIES WITH THE RAINS
MOVING EAST OF THE FORECAST AREA. HRRR AND LOCAL WRF STILL SHOWS SOME POTENTIAL
FOR SOME CONVECTIVE DEVELOPMENT FOR THIS AFTERNOON BEFORE EXITING BY THIS
EVENING. SO HAVE LAID OUT ISOLATED TO SCATTERED POPS FROM WEST TO
EAST. THE PRESSURE GRADIENT CONTINUES TO BE TIGHT FOR SOME PERIODIC
BREEZY CONDITIONS OF 30 TO 40 MPH FOR THIS AFTERNOON. CURRENT
FORECAST HIGHS ARE STILL ON TRACK AS SUNLIGHT FILTERS INTO THE
REGION./17/
./PREVIOUS DISCUSSION...440 AM CDT SUN APR 14 2013
.DISCUSSION...
TONIGHT THROUGH MONDAY NIGHT...
AS WE GO INTO TONIGHT...SKIES WILL ATTEMPT TO CLEAR OVER A MOIST
BOUNDARY LAYER AND RAIN-SOAKED GROUND...AND THIS SHOULD RESULT IN
AREAS OF FOG FOR LATE TONIGHT THROUGH EARLY MONDAY. AFTER A WARM AND
DRY MONDAY...A REPEAT OF STRATUS/FOG WILL BE POSSIBLE MONDAY NIGHT.
/EC/
TUESDAY THROUGH SUNDAY...
NOT MUCH CHANGE IN THE EXTENDED PORTION OF THE FORECAST. RATHER
STOUT SUBTROPICAL RIDGING WILL BE IN PLACE OVER THE SOUTHEASTERN
CONUS TUESDAY AND WEDNESDAY IN ADVANCE OF A DEEP TROUGH TAKING SHAPE
OVER THE WESTERN HALF OF THE COUNTRY. STRONG SURFACE HIGH PRESSURE
OVER THE SOUTHEAST WILL CONTINUE TO PULL WARM/MOIST GULF AIR ACROSS
THE ARKLAMISS THROUGH EARLY THURSDAY BEFORE A COLD FRONT ASSOCIATED
WITH THE AFOREMENTIONED LOW PRESSURE SYSTEM SWINGS ACROSS THE REGION.
TEMPERATURES TUE/WED ARE GOING TO BE WELL ABOVE NORMAL FOR MID APRIL
WITH HIGHS CLIMBING INTO THE MID 80S.
THINGS WILL CHANGE HEADED INTO THURSDAY AS THE COLD FRONT APPROACHES
THE REGION. CLOUD COVER WILL HELP KEEP TEMPS A TAD COOLER ALTHOUGH
HIGHS IN THE UPPER 70S/LOWERS 80S ARE STILL EXPECTED (WARMEST ACROSS
THE EAST). THE MODELS CONTINUE TO DANCE AROUND WITH FRONTAL TIMING
BUT REMAIN FOCUSED IN THE THURSDAY AFTERNOON/THURSDAY EVENING
TIMEFRAME. THE ANTECEDENT WARM/MOIST ATMOSPHERE THAT WILL BE IN
PLACE AHEAD OF THE FRONT SHOULD SET THE STAGE FOR SEVERE WEATHER
POTENTIAL AS THE FRONT PASSES...BUT EXACT DETAILS WITH RESPECT TO
COVERAGE/INTENSITY REMAIN UNCERTAIN THIS FAR IN ADVANCE. SURFACE DEW
POINTS LOOK TO BE IN THE UPPER 60S/NEAR 70 BY THURSDAY AFTERNOON...
AND COUPLED WITH STEEP MID LEVEL LAPSE RATES SHOULD BE SUFFICIENT
FOR SBCAPE VALUES NEAR/IN EXCESS OF 1500J/KG ACROSS AREAS AHEAD OF
THE FRONT. BEST HEIGHT FALLS/SHEAR LOOKS LIKE IT MAY BE CONFINED
ACROSS AREAS FURTHER NORTH THAN SOUTH...BUT WON`T TRY TO GET TOO
SPECIFIC AT THIS POINT. WILL KEEP A MENTION OF SEVERE WEATHER
POTENTIAL IN THE HWO/GRAPHICS FOR THU AFTN/EVE.
MUCH COOLER WEATHER CAN BE EXPECTED IN WAKE OF THE FRONT AS A 1025MB
HIGH PRESSURE CENTER BUILDS OVER THE MS VALLEY. TEMPS WILL LIKELY
FALL BACK BELOW NORMAL FRI THROUGH THE WEEKEND...ALONG WITH CLEAR
SKIES. AS FOR TEMPS/POPS...I DID CONTINUE THE TREND OF TRIMMING AFTN
POPS TUE/WED AS A STRONG CAP ACROSS THE REGION KEEPS THINGS IN
CHECK. WITH THAT SAID...WOULDN`T BE TOTALLY SURPRISED TO SEE A
SHOWER OR THUNDERSTORM EACH AFTN/NOTHING SIGNIFICANT. TEMPS LOOKED
GOOD UNTIL THE FRONT PASSES WHERE COOLER HIGHS/LOWS OFFERED BY THE
EURO MOS FOR THE WEEKEND SEEMED A BIT MORE REASONABLE. /BK/
&&
.AVIATION...WIDESPREAD RAIN...ALONG WITH A FEW THUNDERSTORMS...WILL
CONTINUE ALONG AND EAST OF THE NATCHEZ TRACE CORRIDOR THIS
MORNING...GRADUALLY DIMINISHING FROM THE WEST THROUGH THE EARLY
AFTERNOON. PERIODS OF GUSTY WIND ARE EXPECTED IMMEDIATELY BEHIND THE
HEAVIER RAIN SHIELD. SUSTAINED WIND SPEEDS 20-30 MPH WITH POSSIBLE
GUSTS AROUND 40 MPH WILL DEVELOP AS RAIN DIMINISHES AND CONTINUE 2-3
HOURS BEFORE WIND SPEEDS DECREASE TO 5-15 MPH. CONDITIONS WILL BE
MOSTLY VFR BUT AREAS OF MVFR CIGS/VSBYS CAN BE EXPECTED IN REGIONS
OF HEAVIER RAIN. WIDESPREAD LIFR CONDITIONS MAY DEVELOP LATE TONIGHT
AFTER RAIN HAS ENDED WHEN FOG/LOW STRATUS FORMATION IS EXPECTED. ANY
FOG/STRATUS WILL MIX OUT MID/LATE MONDAY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 74 63 85 68 / 20 7 5 11
MERIDIAN 70 58 82 65 / 29 10 5 11
VICKSBURG 75 61 85 67 / 17 5 6 11
HATTIESBURG 77 63 86 69 / 29 7 8 7
NATCHEZ 76 62 84 70 / 17 4 8 7
GREENVILLE 75 61 83 67 / 16 6 10 12
GREENWOOD 75 62 83 68 / 16 6 5 12
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
17/03/EC/BK
AREA FORECAST DISCUSSION
NWS BILLINGS MT
946 AM MDT SUN APR 14 2013
.UPDATE...
DYNAMIC UPPER TROUGH CONTINUING TO IMPACT SOUTHEAST MONTANA THIS
MORNING WITH AREAS OF HEAVY SNOW. SNOW AMOUNTS HAVE VARIED FROM 3
TO 6 INCHES OVER THE FAR EASTERN ZONES. DRY SLOT HAS MOVED INTO
CARTER COUNTY THIS MORNING BUT WRAP AROUND FROM THE LOW PRESSURE
SYSTEM WILL BRING SNOW BACK INTO THE AREA BY LATE MORNING. CURRENT
HIGHLIGHTS ARE WORKING WELL AND WILL MAKE NO ADJUSTMENTS.
FOR UPDATES THIS MORNING...HAVE INCREASED POPS FOR LIVINGSTON AS
ENERGY SLIDING DOWN THE BACKSIDE OF THE UPPER TROUGH IS BRINGING
LIGHT SNOW. THIS LIGHT SNOW IS EXPECTED TO CONTINUE INTO EARLY
AFTERNOON. BAND OF SNOW HAS SET UP JUST EAST OF BILLINGS AND WAS
SLOWLY SHIFTING TO THE WEST TOWARD BILLINGS. RAP MODELS IS
HANDLING THIS WELL AND IS DEPICTING A BAND OF FRONTOGENESIS TO SET
UP FROM ROUNDUP SOUTHEAST THROUGH BILLINGS TO FORT SMITH. THE RAP
MODEL IS GENERATING SOME GOOD QPF VALUES AND HAVE GONE AHEAD AND
RAISED POPS TO CATEGORICAL FOR THIS AFTERNOON. WINDS ALONG THE
BAND OF LIFT WILL SHIFT TO THE NORTHEAST BRINGING WEAK UPSLOPE
FLOW AND HAVE ADDED 1 TO 2 INCHES OF SNOW ALONG THIS BOUNDARY.
ALSO LOWERED TEMPERATURES FOR BILLINGS THIS AFTERNOON AS COLD AIR
ADVECTS INTO THE AREA. RICHMOND
&&
.SHORT TERM...VALID FOR TDY AND MON...
MODELS HAVE FINALLY COME IN LINE WITH THE SYSTEM IMPACTING THE
FORECAST AREA AND THE GFS HAS APPARENTLY WON OUT. THE NAM HAS
DRAMATICALLY SHIFTED SOUTH WITH THE UPPER LOW POSITION FOR EARLY
TODAY AND COME TO A VIRTUAL AGREEMENT WITH THE GFS OF A COUPLE OF
DAYS AGO. SAME IS TRUE OF THE ECMWF. A SECONDARY UPPER LOW WAS
FORMING WITHIN THE DEEP UPPER TROUGH OVER THE NORTHERN ROCKIES.
THE POSITION OF THIS UPPER LOW WAS OVER FAR SOUTHEAST MONTANA AND
PRESSING TOWARD NORTHWEST SOUTH DAKOTA.
A LARGE SWATH OF SNOWFALL WAS OVER SOUTHEAST MONTANA THIS
HOUR...BASICALLY EAST OF A HYSHAM TO BUSBY LINE. MODERATE TO HEAVY
SNOW HAS BEEN REPORTED IN MILES CITY AND BAKER OVER THE LAST
SEVERAL HOURS. THE HEAVIEST SNOWFALL DOES APPEAR TO BE SHIFTING
NORTHWARD INTO NORTHEAST MONTANA AT THE MOMENT. THE GFS WRAPS
COLDER AIR AND SNOW BACK INTO SOUTHEAST MONTANA TOWARD DAWN...SO
DO EXPECT SNOWFALL TO PICK BACK UP AGAIN. HIGHLIGHTS WILL REMAIN
IN PLACE AS THE SURFACE LOW WRAPS UP AND GENERATES STRENGTHENING
WINDS FOR BLOWING SNOW. AM CONCERNED WITH THE DRIER AIR WORKING
INTO NORTHEAST WYOMING AT THE MOMENT AS THE LOW WRAPS UP. THIS
DRIER AIR MAY BE A WRENCH IN THINGS AND DECREASE SNOW RATES TODAY
FOR THE SOUTHEAST. WILL HAVE TO WATCH THIS CLOSELY. FOR NOW
THOUGH...WILL KEEP HIGHLIGHTS RUNNING.
THE COLDER AIR WILL BACK INTO BILLINGS BY LATE MORNING OR EARLY
AFTERNOON. THIS SHOULD TURN WINDS TO THE NORTH AND NORTHEAST AND
INCREASE UPSLOPE GRADIENTS. UPSLOPE LIGHT SNOW SHOULD DEVELOP
TODAY AS THE COLDER AIR DRIVES IN. THE EAST SLOPES...FROM NYE TO
RED LODGE...SHOULD BE ABLE TO PICK UP A COUPLE INCHES OF UPSLOPE
SNOW TODAY AND EARLY THIS EVENING. WILL BE A CHILLY DAY AS HIGHS
WILL BE EARLY AND BILLINGS WILL STRUGGLE TO GET OUT OF THE 30S
WITH TEMPERATURES HOLDING STEADY OR SLOWLY FALLING THIS AFTERNOON
WITH COLD ADVECTION.
UPSLOPE WILL REMAIN IN PLACE TONIGHT AND MONDAY AS AN UPPER
TROUGH OFF THE PACIFIC NORTHWEST COAST DROPS INTO NORTHERN
CALIFORNIA AND INDUCES SURFACE PRESSURE FALLS. THIS WILL KEEP
THINGS CHILLY ON MONDAY WITH CLOUD COVER AND A CHANCE OF UPSLOPE
LIGHT SNOW. WILL KEEP POPS AT LEAST IN THE HIGH SCATTERED CATEGORY
FOR CENTRAL AND WESTERN ZONES. THE SYSTEM IMPACTING THE EAST WILL
PULL AWAY TONIGHT AND MONDAY AND ALLOW CONDITIONS TO IMPROVE. TWH
.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
THE EXTENDED FORECAST CONTINUES TO APPEAR ON TRACK WITH UNSETTLED
WEATHER THROUGHOUT. TEMPS WILL BE WELL BELOW NORMAL TO START THE
PERIOD...WITH A GRADUAL WARM UP THROUGH THE WEEKEND. THERE IS
STILL MUCH UNCERTAINTY IN THE DETAILS WITH REGARD TO THE EVOLUTION
OF THE PATTERN AND HOW IT WILL IMPACT WEATHER ACROSS THE REGION.
IN GENERAL THE REGION IS DOMINATED BY A BROAD UPPER LEVEL TROF
THROUGHOUT THE EXTENDED PERIOD. THIS SHOULD KEEP SHALLOW COLD AIR
OVER THE AREA...UNTIL RIDGING OVER THE PACIFIC SHIFTS MORE
EASTWARD. THIS IS PROGGED TO BEGIN LATE NEXT WEEK AND CONTINUE TO
SHIFT SLOWLY EASTWARD THROUGH THE WEEKEND...AND AFFECTS A GRADUAL
WARMUP ACROSS THE REGION.
AS FOR PRECIP POTENTIAL...THE NEXT PACIFIC TROF SLIDES THROUGH THE
REGION ON TUESDAY...AND INTO WEDNESDAY. STRONGEST FORCING IS
CURRENTLY PROGGED TO REMAIN SOUTH OF THE REGION TUESDAY...BUT
SHOULD STILL SEE POTENTIAL FOR PRECIP ACROSS THE REGION...THOUGH
ACCUMULATIONS SHOULD BE ON THE LOW END. THE POTENTIAL WEDNESDAY
WILL BE A BIT BETTER...AS TROF IS PROGGED TO LIFT TO THE
NORTHEAST...BUT EXACT TRACK WILL MAKE BIG IMPACT AS TO WHERE
ACCUMULATING SNOWFALL WILL OCCUR. SO FURTHER ATTENTION WILL BE
REQUIRED ON LATER SHIFTS. SLOW PROGRESS OF THE WEATHER SYSTEMS
EASTWARD WILL KEEP THE REGION UNDER NORTHWEST FLOW ALOFT...THROUGH
THE REMAINDER OF THE PERIOD...WITH SEVERAL SHORTWAVES THROUGH THE
FLOW TO BRING CONTINUED SHOWER POTENTIAL ACROSS THE REGION THROUGH
NEXT WEEKEND. AAG
&&
.AVIATION...
SNOW ACROSS EASTERN MONTANA...INCLUDING KMLS AND KBHK...WILL
CONTINUE THROUGH THE DAY...RESULTING IN WIDESPREAD MVFR/IFR
CONDITIONS...AND LOCALIZED LIFR/VLIFR CONDITIONS. SNOW SHOWERS ARE
ALSO EXPECTED TO REDEVELOP TODAY ACROSS THE WESTERN
ROUTES...INCLUDING KBIL...KLVM...AND KSHR...RESULTING IN LOCALIZED
MVFR/IFR CONDITIONS IN LOWERED CIGS AND VIS. WINDS ARE ALSO
EXPECTED TO BECOME BRISK...RESULTING IN POTENTIAL FOR BLOWING SNOW
AND FURTHER REDUCED VIS. AAG
&&
.PRELIMINARY POINT TEMP/POPS...
TDY MON TUE WED THU FRI SAT
-------------------------------------------------------
BIL 038 023/037 022/036 021/041 024/051 031/054 034/056
9/J 55/S 35/S 33/S 21/B 23/W 33/W
LVM 037 018/036 018/034 018/040 019/049 028/052 032/055
7/J 55/S 54/S 32/S 22/W 23/W 33/W
HDN 036 023/038 021/036 018/041 022/051 028/055 032/057
9/J 65/O 35/S 34/S 21/B 24/W 44/W
MLS 032 022/036 020/034 019/037 021/046 027/052 030/053
+/S 75/S 34/S 23/S 11/E 23/W 22/W
4BQ 032 020/035 019/034 015/035 017/043 026/051 028/051
+/S 74/S 25/S 44/S 11/E 23/W 33/W
BHK 027 020/033 018/033 017/031 016/039 023/046 028/047
+/S 74/S 33/S 23/S 11/E 22/W 32/W
SHR 034 020/036 020/033 018/036 019/046 024/051 028/052
6/J 45/S 26/S 55/S 22/W 23/W 34/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL MIDNIGHT MDT TONIGHT
FOR ZONES 31-32-36-58.
WINTER STORM WARNING IN EFFECT UNTIL MIDNIGHT MDT TONIGHT FOR
ZONES 33-37.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
139 PM CDT SUN APR 14 2013
.UPDATE...
ISSUED AT 139 PM CDT SUN APR 14 2013
MAIN CHANGE FOR THIS UPDATE IS TO THROW THE SOUTHWESTERN COUNTIES
INTO A BLIZZARD WARNING. VIS HAVE BEEN UP AND DOWN IN RANSOM AND
SARGENT COUNTIES DUE TO THE VARIOUS INTENSITY OF THE BANDS MOVING
THROUGH. HOWEVER...REGIONAL RADAR SHOWS QUITE A BIT MORE SNOW
MOVING SLOWLY NORTH OUT OF SOUTH DAKOTA. GUSTS ARE ABOVE 35 MPH IN
MANY SPOTS...EVEN AS FAR NORTH AS VALLEY CITY WHERE THE VIS HAS
NOT QUITE GONE DOWN YET. HOWEVER...ND DOT HAS REPORTED THAT PLOWS
HAVE BEEN PULLED DUE TO POOR VIS SOUTH OF VALLEY CITY AND THE
HEAVY SNOW WILL CONTINUE TO MOVE NORTH INTO GRIGGS AND EDDY COUNTY
THIS AFTERNOON. SNOW WILL BE INCREASING AND WINDS CONTINUING
THROUGH AT LEAST 03Z WHEN THE CENTER OF THE SFC LOW ENTERS THE
SOUTHERN FORECAST AREA. WILL INCLUDE OUR SOUTHWESTERN COUNTIES IN
BLIZZARD FOR A WHILE THIS EVENING BEFORE CONVERTING BACK TO WINTER
STORM AS WINDS SHOULD GO DOWN BUT SNOWFALL CONTINUES.
OTHER CHANGES INCLUDED SLOWING DOWN NORTHWARD PROGRESSION OF POPS
A BIT MORE AND TRIMMING SNOW TOTALS A BIT IN THE SOUTHEASTERN
COUNTIES WHERE THEY MAY GET THE DRY SLOT LATER TONIGHT. OTHER
UPDATE ISSUED AT 959 AM CDT SUN APR 14 2013
TIMING OF THE INCOMING SNOW AND WHAT TO DO ABOUT THE WINTER
HEADLINES CONTINUES TO BE THE MAIN ISSUE. THE NORTHWARD
PROGRESSION OF ACCUMULATING SNOW CONTINUES TO SLOW...WITH THE
RECENT SHORT RANGE MODELS AND RADAR TRENDS BEARING THIS OUT. ONLY
A FEW FLURRIES HAVE PROGRESSED AS FAR NORTH AS VALLEY CITY...AND
THE NAM...RAP...AND HRRR ARE ALL IN PRETTY GOOD AGREEMENT OF
ACCUMULATING SNOW NOT REALLY STARTING IN FAR UNTIL THE 18-21Z TIME
FRAME AND EVEN LATER FURTHER NORTH. ON THE OTHER HAND...HEAVIER
RADAR RETURNS HAVE ENTERED SARGENT COUNTY AND THE FORMAN WEB CAM
SHOWS CONDITIONS DETERIORATING RAPIDLY. FOR NOW...WILL LEAVE THE
HEADLINES ALONE BUT SLOW DOWN THE TIMING OF POPS AGAIN. WILL
UPDATE THE WSW WORDING TO SLOW THE TIMING A BIT AND MENTION A
RAPID CHANGE FROM DECENT CONDITIONS TO NEAR BLIZZARD AS HEAVY SNOW
ACTUALLY ARRIVES.
UPDATE ISSUED AT 645 AM CDT SUN APR 14 2013
THE MAIN CHALLENGE WILL BE TO DELAY THE START TIME OF THE WINTER
STORM WARNINGS...WITH SNOW STARTING LATER IN ALL AREAS.
SNOW...HEAVY AT TIMES WILL MOVE INTO THE SOUTHERN RED RIVER VALLEY
THIS MORNING...SPREADING TO THE CANADIAN BORDER BY LATE THIS
AFTERNOON. WE WILL ALSO EXTEND THE WINTER STORM WARNING UNTIL
18Z MON WITH A SLOWER MOVING SYSTEM. CONDITIONS WILL DETERIORATE
RAPIDLY TODAY ONCE HEAVY SNOW BEGINS...AND WINDS INCREASE. WE
WILL NEED TO MONITOR THE POTENTIAL FOR BLIZZARD CONDITIONS...AND
HAVE MENTIONED NEAR BLIZZARD CONDITIONS IN THE WSW MAINLY ALONG
AND WEST OF THE RED RIVER VALLEY.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 330 AM CDT SUN APR 14 2013
THE MAIN CHALLENGE CONTINUES TO BE IMPENDING WINTER STORM. MODELS
HAVE TRENDED SLOWER AND A BIT FURTHER SOUTH WITH THE SFC/UPPER
LEVEL LOW TRACKS. FOR NOW WILL MAINTAIN ALL HEADLINE
TIMING...ALTHOUGH SNOW WILL BE DELAYED AND WILL REFLECT THIS IN
THE GRIDS.
FOR TODAY...STRONG FORCING FOR ASCENT PER QG/OMEGA FIELDS WILL
MOVE FROM SOUTH TO NORTH THROUGH THE DAY. EXPECT SNOW...HEAVY AT
TIMES ALONG WITH BLOWING/DRIFTING SNOW. THERE WILL BE TIMES OF
NEAR BLIZZARD CONDITIONS POSSIBLE MAINLY IN EASTERN ND WHERE HEAVY
SNOW RATES ARE POSSIBLE ALONG WITH WINDS GUSTING TO NEAR 40 MPH.
THEREFORE...TRAVEL WILL BECOME DIFFICULT WHEN SNOW BEGINS. FURTHER
NORTH NEAR THE CANADIAN BORDER...SNOW MAY NOT BEGIN UNTIL NEAR
00Z. SNOW SHOULD BEGIN NEAR GFK AROUND 20Z...AND AROUND 16Z IN FARGO.
FOR TONIGHT...AS THE LOW LIFTS SLOWLY NORTH AND EAST...EXPECT A
LARGE DEFORMATION SNOW BAND FOR THE REGION. SNOW COULD BE HEAVY
THIS EVENING ALONG WITH CONSIDERABLE BLOWING/DRIFTING AND NEAR
BLIZZARD CONDITIONS POSSIBLE.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM CDT SUN APR 14 2013
ON MONDAY...THE STORM SYSTEM WILL SLOWLY MOVE AWAY FROM THE REGION
BY AFTERNOON. GIVEN THE SLOW START TO THE STORM...SNOW WILL
CONTINUE IN THE NORTH THROUGH 18Z AT LEAST...AND HAVE INCREASED
SNOW CHANCES HERE. WINDS SHOULD SLOWLY DIMINISH AS THE PRESSURE
GRADIENT WEAKENS BY AFTERNOON.
FOR TUESDAY...EXPECT SOME LINGERING LIGHT SNOW IN THE NORTH NEAR
WEAK CYCLONIC FLOW. TEMPS WILL CONTINUE WELL BELOW NORMAL FOR MID
APRIL AS WINTER LIKE CONDITIONS REMAIN OVER THE REGION ALONG WITH
A FRESH SNOW PACK.
ATTENTION ON WEDNESDAY TURNS TO ANOTHER DEVELOPING SYSTEM TO THE
WEST. 00Z MODELS CONTINUE TO INDICATE A PROGRESSIVE LONGWAVE TROUGH
OVER THE ROCKIES WITH SHORTWAVE ENERGY BEGINNING TO LIFT OUT INTO
THE PLAINS...AND SFC CYCLOGENESIS TAKING PLACE OVER THE SOUTHERN
HIGH PLAINS. THIS SYSTEM IS EXPECTED TO LIFT NORTHEAST ALONG THE
LOW-LEVEL BAROCLINIC ZONE LATER WEDNESDAY AND THURSDAY. IN RECENT
DAYS...THE OPERATIONAL MODELS HAVE NOT BEEN CONSISTENT IN THE
EVOLUTION OF SHORTWAVE ENERGY THROUGH THE BROADER TROUGH. THE 00Z
GEM/GFS AND ESPECIALLY THE 18Z DGEX SUGGEST A SLOWER AND FARTHER
NORTH SOLUTION COMPARED WITH THE ECMWF... AND THUS WOULD YIELD
BETTER SNOW CHANCES FOR THE REGION. TIME OF YEAR AND STRONG
DOWNSTREAM RIDGING WOULD SUPPORT A FARTHER NORTH SOLUTION...BUT
OVERALL CONFIDENCE ON THE TRACK/TIMING IS STILL LOW...GIVEN THE LACK
OF MODEL CONSISTENCY. THE SYSTEM BEARS WATCHING...THOUGH. WILL KEEP
THE HIGHEST POPS ACROSS THE SOUTHEAST HALF OF THE REGION...IN
AGREEMENT WITH THE OVERALL MODEL CONSENSUS...WITH PRECIP CHANCES
LINGERING INTO THURSDAY NIGHT.
OTHERWISE...TEMPS ARE EXPECTED TO REMAIN MUCH BELOW MID-APRIL
AVERAGES...WITH NORTHWEST FLOW ALOFT. HIGH TEMPS LIKELY WILL REMAIN
IN 30S FOR MUCH OF THE PERIOD WITH LOWS IN THE 20S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 139 PM CDT SUN APR 14 2013
HEAVY SNOW WILL MOVE FROM SOUTH TO NORTH THIS AFTERNOON AND THROUGH
THE NIGHT...ALONG WITH INCREASING EASTERLY WINDS. THE OVERALL SYSTEM
IS MOVING MUCH SLOWER THAN PREVIOUSLY FORECAST SO THAT HEAVY SNOW
ONSET HAS BEEN DELAYED 3 TO 6 HOURS COMPARED TO THE 12 UTC TAFS.
WINDS WILL GUST OVER 30 KTS AT TIMES THIS AFTERNOON AND OVERNIGHT...
AND TURN MORE NORTHERLY LATER TONIGHT. EXPECT IFR CONDITIONS WITH
THE HEAVIEST SNOW BANDS ALONG WITH BLOWING SNOW AND VISIBILITY
REDUCTIONS TO 1/4 MILE OR LESS. CONDITIONS WILL BE SLOW TO IMPROVE
THROUGH THE DAY ON MONDAY...ESPECIALLY AT KDVL...KGFK AND KTVF.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER STORM WARNING FROM 10 PM THIS EVENING TO 1 PM CDT MONDAY
FOR NDZ024-028-038-049-052.
BLIZZARD WARNING UNTIL 10 PM CDT THIS EVENING FOR NDZ024-028-038-
049-052.
WINTER STORM WARNING UNTIL 1 PM CDT MONDAY FOR NDZ029-030-039-
053.
WINTER STORM WARNING UNTIL 1 PM CDT MONDAY FOR NDZ006>008-
014>016-026-027-054.
MN...WINTER STORM WARNING UNTIL 1 PM CDT MONDAY FOR MNZ002-003-
022>024-027>032-040.
WINTER STORM WARNING UNTIL 1 PM CDT MONDAY FOR MNZ001-004>009-
013>017.
&&
$$
UPDATE...JR
SHORT TERM...DK
LONG TERM...MAKOWSKI
AVIATION...ROGERS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1002 AM CDT SUN APR 14 2013
.UPDATE...
ISSUED AT 959 AM CDT SUN APR 14 2013
TIMING OF THE INCOMING SNOW AND WHAT TO DO ABOUT THE WINTER
HEADLINES CONTINUES TO BE THE MAIN ISSUE. THE NORTHWARD
PROGRESSION OF ACCUMULATING SNOW CONTINUES TO SLOW...WITH THE
RECENT SHORT RANGE MODELS AND RADAR TRENDS BEARING THIS OUT. ONLY
A FEW FLURRIES HAVE PROGRESSED AS FAR NORTH AS VALLEY CITY...AND
THE NAM...RAP...AND HRRR ARE ALL IN PRETTY GOOD AGREEMENT OF
ACCUMULATING SNOW NOT REALLY STARTING IN FAR UNTIL THE 18-21Z TIME
FRAME AND EVEN LATER FURTHER NORTH. ON THE OTHER HAND...HEAVIER
RADAR RETURNS HAVE ENTERED SARGENT COUNTY AND THE FORMAN WEB CAM
SHOWS CONDITIONS DETERIORATING RAPIDLY. FOR NOW...WILL LEAVE THE
HEADLINES ALONE BUT SLOW DOWN THE TIMING OF POPS AGAIN. WILL
UPDATE THE WSW WORDING TO SLOW THE TIMING A BIT AND MENTION A
RAPID CHANGE FROM DECENT CONDITIONS TO NEAR BLIZZARD AS HEAVY SNOW
ACTUALLY ARRIVES.
UPDATE ISSUED AT 645 AM CDT SUN APR 14 2013
THE MAIN CHALLENGE WILL BE TO DELAY THE START TIME OF THE WINTER
STORM WARNINGS...WITH SNOW STARTING LATER IN ALL AREAS.
SNOW...HEAVY AT TIMES WILL MOVE INTO THE SOUTHERN RED RIVER VALLEY
THIS MORNING...SPREADING TO THE CANADIAN BORDER BY LATE THIS
AFTERNOON. WE WILL ALSO EXTEND THE WINTER STORM WARNING UNTIL
18Z MON WITH A SLOWER MOVING SYSTEM. CONDITIONS WILL DETERIORATE
RAPIDLY TODAY ONCE HEAVY SNOW BEGINS...AND WINDS INCREASE. WE
WILL NEED TO MONITOR THE POTENTIAL FOR BLIZZARD CONDITIONS...AND
HAVE MENTIONED NEAR BLIZZARD CONDITIONS IN THE WSW MAINLY ALONG
AND WEST OF THE RED RIVER VALLEY.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 330 AM CDT SUN APR 14 2013
THE MAIN CHALLENGE CONTINUES TO BE IMPENDING WINTER STORM. MODELS
HAVE TRENDED SLOWER AND A BIT FURTHER SOUTH WITH THE SFC/UPPER
LEVEL LOW TRACKS. FOR NOW WILL MAINTAIN ALL HEADLINE
TIMING...ALTHOUGH SNOW WILL BE DELAYED AND WILL REFLECT THIS IN
THE GRIDS.
FOR TODAY...STRONG FORCING FOR ASCENT PER QG/OMEGA FIELDS WILL
MOVE FROM SOUTH TO NORTH THROUGH THE DAY. EXPECT SNOW...HEAVY AT
TIMES ALONG WITH BLOWING/DRIFTING SNOW. THERE WILL BE TIMES OF
NEAR BLIZZARD CONDITIONS POSSIBLE MAINLY IN EASTERN ND WHERE HEAVY
SNOW RATES ARE POSSIBLE ALONG WITH WINDS GUSTING TO NEAR 40 MPH.
THEREFORE...TRAVEL WILL BECOME DIFFICULT WHEN SNOW BEGINS. FURTHER
NORTH NEAR THE CANADIAN BORDER...SNOW MAY NOT BEGIN UNTIL NEAR
00Z. SNOW SHOULD BEGIN NEAR GFK AROUND 20Z...AND AROUND 16Z IN FARGO.
FOR TONIGHT...AS THE LOW LIFTS SLOWLY NORTH AND EAST...EXPECT A
LARGE DEFORMATION SNOW BAND FOR THE REGION. SNOW COULD BE HEAVY
THIS EVENING ALONG WITH CONSIDERABLE BLOWING/DRIFTING AND NEAR
BLIZZARD CONDITIONS POSSIBLE.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM CDT SUN APR 14 2013
ON MONDAY...THE STORM SYSTEM WILL SLOWLY MOVE AWAY FROM THE REGION
BY AFTERNOON. GIVEN THE SLOW START TO THE STORM...SNOW WILL
CONTINUE IN THE NORTH THROUGH 18Z AT LEAST...AND HAVE INCREASED
SNOW CHANCES HERE. WINDS SHOULD SLOWLY DIMINISH AS THE PRESSURE
GRADIENT WEAKENS BY AFTERNOON.
FOR TUESDAY...EXPECT SOME LINGERING LIGHT SNOW IN THE NORTH NEAR
WEAK CYCLONIC FLOW. TEMPS WILL CONTINUE WELL BELOW NORMAL FOR MID
APRIL AS WINTER LIKE CONDITIONS REMAIN OVER THE REGION ALONG WITH
A FRESH SNOW PACK.
ATTENTION ON WEDNESDAY TURNS TO ANOTHER DEVELOPING SYSTEM TO THE
WEST. 00Z MODELS CONTINUE TO INDICATE A PROGRESSIVE LONGWAVE TROUGH
OVER THE ROCKIES WITH SHORTWAVE ENERGY BEGINNING TO LIFT OUT INTO
THE PLAINS...AND SFC CYCLOGENESIS TAKING PLACE OVER THE SOUTHERN
HIGH PLAINS. THIS SYSTEM IS EXPECTED TO LIFT NORTHEAST ALONG THE
LOW-LEVEL BAROCLINIC ZONE LATER WEDNESDAY AND THURSDAY. IN RECENT
DAYS...THE OPERATIONAL MODELS HAVE NOT BEEN CONSISTENT IN THE
EVOLUTION OF SHORTWAVE ENERGY THROUGH THE BROADER TROUGH. THE 00Z
GEM/GFS AND ESPECIALLY THE 18Z DGEX SUGGEST A SLOWER AND FARTHER
NORTH SOLUTION COMPARED WITH THE ECMWF... AND THUS WOULD YIELD
BETTER SNOW CHANCES FOR THE REGION. TIME OF YEAR AND STRONG
DOWNSTREAM RIDGING WOULD SUPPORT A FARTHER NORTH SOLUTION...BUT
OVERALL CONFIDENCE ON THE TRACK/TIMING IS STILL LOW...GIVEN THE LACK
OF MODEL CONSISTENCY. THE SYSTEM BEARS WATCHING...THOUGH. WILL KEEP
THE HIGHEST POPS ACROSS THE SOUTHEAST HALF OF THE REGION...IN
AGREEMENT WITH THE OVERALL MODEL CONSENSUS...WITH PRECIP CHANCES
LINGERING INTO THURSDAY NIGHT.
OTHERWISE...TEMPS ARE EXPECTED TO REMAIN MUCH BELOW MID-APRIL
AVERAGES...WITH NORTHWEST FLOW ALOFT. HIGH TEMPS LIKELY WILL REMAIN
IN 30S FOR MUCH OF THE PERIOD WITH LOWS IN THE 20S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 613 AM CDT SUN APR 14 2013
HEAVY SNOW WILL MOVE FROM SOUTH TO NORTH TODAY...ALONG WITH
INCREASING EASTERLY WINDS. WINDS WILL GUST OVER 30KT AT TIMES THIS
AFTERNOON AND OVERNIGHT...AND TURN MORE NORTHERLY LATER TONIGHT.
EXPECT IFR CONDITIONS POSSIBLE NEAR ANY SNOW BANDS ALONG WITH
BLOWING SNOW POSSIBLE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER STORM WARNING UNTIL 1 PM CDT MONDAY FOR NDZ049-052-053.
WINTER STORM WARNING UNTIL 1 PM CDT MONDAY FOR NDZ028>030-038-
039.
WINTER STORM WARNING FROM 4 PM THIS AFTERNOON TO 1 PM CDT MONDAY
FOR NDZ006>008-014>016-024-026-027-054.
MN...WINTER STORM WARNING UNTIL 1 PM CDT MONDAY FOR MNZ029>032-040.
WINTER STORM WARNING UNTIL 1 PM CDT MONDAY FOR MNZ002-003-
022>024-027-028.
WINTER STORM WARNING FROM 4 PM THIS AFTERNOON TO 1 PM CDT MONDAY
FOR MNZ001-004>009-013>017.
&&
$$
UPDATE...JR
SHORT TERM...DK
LONG TERM...MAKOWSKI
AVIATION...DK
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 304 PM CDT SUN APR 14 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ELONGATED LOW
PRESSURE SPINNING ALONG THE IOWA/NEBRASKA BORDER THIS
AFTERNOON...AND A SURFACE WARM FRONT EXTENDING EASTWARD ACROSS
NORTHERN ILLINOIS. SOUTH OF THE WARM FRONT...TEMPERATURES ARE IN
THE 60S AND 70S. BUT NORTH OF THE FRONT...A 50KT SSW LLJ IS LEADING TO
A BAND OF PRECIPITATION WHICH IS NOW PUSHING INTO THE NORTHERN
SECTIONS OF THE BADGER STATE. TEMPERATURES REMAIN IN THE 20S AND
30S WITHIN THIS BAND OF PRECIP...WHERE LOCATIONS OVER CENTRAL
WISCONSIN HAVE PICKED UP A QUICK 2-3 INCHES OF WET SNOW. A FEW
SPOTTER REPORTS HAVE CONFIRMED WHAT DUAL POL IS SHOWING...THAT SNOW
IS MIXING WITH RAIN AND SLEET...WITH THE CHANGE OVER NOW SPREADING
INTO SOUTHERN MARATHON AND SHAWANO COUNTIES. ADDITIONALLY...SURFACE
WET BULB ZERO TEMPS ARE SPREADING NORTHEAST INTO EAST-CENTRAL
WISCONSIN...SO SHOULDNT SEE TOO MUCH MORE ACCUMS IN THESE AREAS.
STILL EXPECTING THE MODERATE TO HEAVY SNOW TO SPREAD INTO
NORTH-CENTRAL WISCONSIN THIS AFTERNOON WHERE A QUICK 3 INCHES WILL
LIKELY FALL. WILL CONTINUE TO HANDLE THE SNOWFALL WITH SPS
UPDATES. PRECIP CONTINUES TO BE THE MAIN FORECAST CONCERN FOR THIS
FORECAST.
TONIGHT...LOW PRESSURE WILL OCCLUDE AS IT LIFTS NORTH OVER SOUTHERN
MINNESOTA...WHILE THE OCCLUDED/COLD FRONT WILL SWEEP ACROSS THE AREA
LATE THIS EVENING AND THROUGH THE OVERNIGHT HOURS. SNOW/SLEET LOOK
TO BE ONGOING OVER NORTH-CENTRAL WISCONSIN AT THE START OF THE
EVENING WHILE CONDITIONS LOOK TO BE DRY FOR A PERIOD OVER
EAST-CENTRAL AND POSSIBLY FAR NORTHEAST WISCONSIN. THIS DRY PERIOD
OVER THE EAST WILL BE SHORT-LIVED HOWEVER...AS A BAND OF SHOWERS AND
EMBEDDED THUNDERSTORMS WILL MOVE THROUGH ALONG THE OCCLUDED/COLD
FRONT. PROGGED SOUNDINGS INDICATE THAT PTYPE SHOULD BE MAINLY RAIN
ACROSS THE REGION BY THE TIME THIS BAND ARRIVES...WHICH WILL LOOK TO
DUMP AROUND 0.75 INCHES OF RAIN OVER WESTERN SECTIONS OF THE CWA.
AMOUNTS SHOULD DROP OFF TO THE EAST AS INSTABILITY IS LOST THROUGH
THE NIGHT. BEST CHANCES OF THUNDER LOOK TO OCCUR OVER CENTRAL AND
EAST-CENTRAL AND WILL KEEP IT IN THE FORECAST. TEMPERATURES WILL
LIKELY PEAK LATE IN THE EVENING OR EARLY OVERNIGHT...JUST AHEAD OF
THE FRONT. LOWS IN THE 30S AND 40S.
MONDAY...OCCLUDED LOW PRESSURE WILL LIFT NE ACROSS NORTHERN
MINNESOTA. PRECIP WILL HAVE EXITED ALONG THE FRONT BY THE START OF
THE PERIOD AND SKIES WILL LIKELY TURN MOSTLY CLEAR FOR A PERIOD
DURING THE MORNING. HOWEVER...AS COLDER AIR FILTERS IN FROM THE
WEST AND MID-LEVEL TEMPS COOL...STEEPENING LOW LEVEL LAPSE RATES AND
WRAP AROUND MOISTURE WILL LEAD TO INCREASING CLOUDS FROM LATE
MORNING THROUGH THE REST OF THE DAY. COULD SEE A FEW INSTABILITY
RAIN AND SNOW SHOWERS DEVELOP OVER CENTRAL AND NORTHEAST WISCONSIN
IN THE AFTERNOON. GUSTY SOUTHWEST WINDS WILL BRING IN THE WARMEST
TEMPS THE AREA HAS SEEN IN SOME TIME...AND WILL GO WITH HIGHS
RANGING FROM THE LOW 40S NORTH TO THE MID 50S NEAR LAKE MICHIGAN.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 304 PM CDT SUN APR 14 2013
FLOOD POTENTIAL IS PROBABLY THE MAIN CHALLENGE FOR THIS FORECAST
PERIOD. THE COLD FRONT MOVES THROUGH MONDAY WITH DRY BUT
SEASONABLE AIR FOLLOWING FOR MONDAY NIGHT THROUGH TUESDAY NIGHT.
SNOW WILL PROBABLY BE GONE OVER MUCH OF THE AREA BELOW 1000 FT
ELEVATION BY THEN WITH THAT SNOW MELT PROBABLY CONTRIBUTING TO
RISES OF THE WOLF RIVER AND SMALL STREAMS OVER EAST CENTRAL
WISCONSIN. MODELS ARE NOW IN GENERAL AGREEMENT WITH SURFACE LOW THAT
MOVES NORTHEAST FROM SOUTHERN PLAINS TO LOWER MICHIGAN WEDNESDAY
THROUGH THURSDAY. LOOKS LIKE THIS WILL BE A LARGELY RAIN EVENT
UNLESS THE STORM TRACKS FURTHER SOUTH. A RAIN EVENT COUPLED BY
SNOW MELT IN THE NORTH WILL LIKELY CAUSE SOME FLOODING OF SMALL
STREAMS AROUND THE AREA BY THURSDAY BUT SIGNIFICANTLY COLDER AND
DRIER AIR WILL SLOW SNOW MELT FRIDAY AND SATURDAY.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1226 PM CDT SUN APR 14 2013
SNOW...MODERATE TO HEAVY AT TIMES...WILL CONTINUE TO
MOVE NORTHEAST ACROSS THE REGION INTO THE AFTERNOON. THE SNOW WILL
CHANGE OVER TO RAIN OVER THE FOX VALLEY AND CENTRAL WISCONSIN AROUND
MID AFTERNOON BUT NOT BEFORE 1-3 INCHES OF ACCUMULATION OCCUR. SNOW
WILL CHANGE OVER TO SLEET AND RAIN OVER NORTHERN WISCONSIN LATE THIS
AFTERNOON OR EARLY THIS EVENING AND ACCUMULATIONS WILL LIKELY REACH
IN THE 2-4 INCH RANGE. THEN A COLD FRONT WILL SWEEP ACROSS THE
REGION TONIGHT. HAVE DELAYED THE TIMING OF THE PRECIPITATION
ASSOCIATED WITH THE FRONT BY A COUPLE HOURS...BUT SHOULD SEE A BAND
OF MODERATE TO HEAVY RAIN PASS ACROSS THE REGION LATE THIS EVENING
INTO THE OVERNIGHT HOURS. THE RAIN WILL PUSH TO THE EAST LATE
TONIGHT AND WILL SEE VFR CONDITIONS RETURN MONDAY MORNING FOR MUCH
OF THE REGION.
&&
.HYDROLOGY...
ISSUED AT 304 PM CDT SUN APR 14 2013
CONTINUED CONCERNS FOR FLOODING ISSUES GIVEN EXPECTED
QPF WITH THE FRONTAL PASSAGE TONIGHT. AN ADDITIONAL THREE QUARTERS
TO AN INCH OF PRECIP MAY FALL OVER CENTRAL AND NORTH-CENTRAL
WISCONSIN BY MONDAY MORNING. WARMER TEMPERATURES TONIGHT AND MONDAY
WILL ADD SNOW MELT INTO THE EQUATIONS. CONCERNS ADDRESSED IN CURRENT
ESF PRODUCT AND RIVER FLOOD STATEMENTS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......MPC
HYDROLOGY......MPC