Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 03/25/14
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
149 PM EDT SUN MAR 23 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TODAY. HIGH PRESSURE FROM THE UPPER
GREAT LAKES WILL BUILD OVER OUR AREA MONDAY AND MONDAY NIGHT AND
THEN MOVE EAST. A LOW PRESSURE SYSTEM WILL DEVELOP IN THE EASTERN
GULF OF MEXICO LATE MONDAY AND THEN TRACK TO THE NORTHEAST,
INTENSIFYING AS IT MOVES TO THE EAST OF THE AREA ON TUESDAY NIGHT.
HIGH PRESSURE WILL BUILD INTO THE REGION THROUGH THURSDAY BEFORE
PUSHING OFFSHORE. ANOTHER LOW PRESSURE SYSTEM WILL PASS TO THE NORTH
OF THE AREA, DRAGGING A COLD FRONT THROUGH ON FRIDAY NIGHT INTO
SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SEEMS AS THOUGH THE LATEST RAP/SREF/HRRR HAVE THE BEST HANDLE ON
THE NORTHWARD EXTENT OF THE PRECIPITATION FALLING ACROSS SW
VIRGINA AT THIS TIME. THAT BEING SAID HAVE INCREASED POPS EVEN
FURTHER ACROSS OUR SOUTHERN DELMARVA ZONES INTO THE LIKELY
SPECTRUM AND SLOWED THE DEPARTURE OF THE MID-LEVEL WAVE BY AN HOUR
OR SO. TEMPERATURES LOOK GOOD AT THIS POINT SO ONLY MADE A FEW
ADJUSTMENTS TO THEM.
OTHERWISE, THE GFS INITIALIZATION AT 500MB LOOKED SLIGHTLY BETTER
THAN THE WRF-NMMB. UP IN NORTHERN CANADA AND ALASKA, NOT THAT
THEIR 00Z SOLUTION OUTCOMES WERE COLLABORATIVE, THE GFS AND ECMWF
INITIALIZATIONS WERE CLOSE. THE REX HIGH IS SLIGHTLY STRONGER OVER
ALASKA THAN INITIALIZED AND THE IMPLICATION WOULD BE THAT THE LAST
PIECE OF THE PUZZLE, THE SHORT WAVE ENTERING NORTHWEST TERRITORY
AND NUNAVUT BORDER IS COMING IN SLIGHTLY HOTTER THAN INITIALIZED.
THE NEXT SOUNDING RUN SHOULD FINALLY HAVE A BETTER CAPTURE AND
LAND BASED RAOB SAMPLING OF THIS FEATURE. CLOSER TO HOME THE GFS
LOOKED SLIGHTLY WARMER AND BETTER AT 850MB AND 925MB WITH ITS
INITIALIZATION AND WAS USED MORE SO TODAY.
SECONDARY FRONT WAS CLEARLY SHOWING ON THE 925MB AND 850MB ANALYSES
ALONG THE MI AND CANADIAN BORDER. THIS SECOND BOUNDARY HAS OPENED
THE DOOR FOR POPS SOUTH AS WAVES ARE FORMING ON THE FRONT AND THE
FRONT ITSELF IS STALLING. THE FORCING THAT THERE IS WITHIN OUR CWA
IS EXTREMELY HI BASED (FGEN FORCING AND ISENTROPIC LIFT CENTERED
AROUND 600MB) WITH NO FCST MID LEVEL WAA THIS FAR NORTH. PLENTY OF
DRY AIR BELOW IT. THE FCST MID LEVEL QVEC CONVERGENCE IS OUTPACING
THE MOISTURE AND THE MOISTURE IS OUTPACING THE DPVA. THE NET RESULT
IS NOT MUCH PCPN IN OUR CWA, EVEN THOUGH MEASURABLE HAS TRENDED
NORTHWARD FROM LAST NIGHT.
LOOKING AT MODELING VERIFICATION, IN SPITE OF THE SLIGHTLY WEAKER
INITIALIZATION, THE WRF-NMMB VERIFIED THE BEST AT 06Z WITH ITS QPF
VS REALITY IN THE LOWER MS VLY. OUR MEASURABLE POPS ARE VERY CLOSE
TO THE OP WRF-NMMB AND RAP COMBO, GENERALLY CLOSER TO THE .05"
ISOHYET ON THE GLOBAL MODELS. GIVEN THAT THEY ARE ALREADY TOO LOW,
WRF-NMMB 2M TEMPS NOT USED AND WE SIDED WITH THE WARMER GFS MAV
GUIDANCE TODAY. GIVEN THIS AND THE LIGHT PCPN INTENSITY, PTYPE SOUTH
ALL RAIN. WE DID KEEP THE CHANCE OF FLURRIES FAR NW AS THE FRONT
APPROACHES.
TEMPS CONTINUE TO OUTPERFORM STAT GUIDANCE, BUT TODAY WE ARE
CONCERNED THAT MAYBE CLOUDINESS WILL ASSIST AND WE DID NOT GO ABOVE
GFS MOS. CWA IN A SEMI-COLISH SPOT WRT PRESSURE GRADIENT, SO NOT A
WINDY DAY AS YESTERDAY BECAME ONCE THE SUN BROKE OUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
WE KEPT LOW CHANCE POPS IN THRU 23Z SOUTH IN LINE WITH LATEST RAP.
THEN AS THE SECONDARY COLD FRONT COMES THRU, WE SHOULD HAVE A WIND
PICK-UP DURING THE EVENING INTO THE EARLY OVERNIGHT. THE WRF-NMMB
STARTS TRAPPING MOISTURE UNDERNEATH THE DEVELOPING SUBSIDENCE
INVERSION. ATTM WHILE THERE IS SOME CAA SC, IT DOES NOT APPEAR TO BE
SOLID. WE CONTINUE TO SIDE CLOSER TO THE MORE OPTIMISTIC GFS AND
ECMWF SKY SOLUTIONS. MIN TEMPS A STAT GUIDANCE BLEND. GIVEN THE CAA
AND THE THERMAL TROF PEAKING AT 12Z, EXPECT A SLIGHTLY LATER THAN
USUAL MORNING MIN ON MONDAY.
&&
.LONG TERM /MONDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL BE ACROSS THE REGION MONDAY AND MONDAY NIGHT.
DRY WEATHER WITH BELOW NORMAL TEMPERATURES EXPECTED. THE HIGHS
MONDAY WILL ONLY BE IN THE LOW/MID 30S IN MOST AREAS WITH SOME
UPPER 20S FAR NORTH. THESE READINGS ARE SOME 10 TO 15 DEGREES
BELOW AVERAGE FOR MID/LATE MARCH. A VERY DRY AIR MASS WILL BE IN
PLACE WITH DEW POINTS IN THE SINGLE DIGITS AND SOME SUB-ZERO DEW
POINTS DURING THE AFTERNOON.
A COMPLEX SYSTEM WILL CAUSE A DEEP LOW PRESSURE SYSTEM TO BOMB OFF
THE EAST COAST TUE NIGHT INTO WED. LOW PRESSURE WILL MOVE UP FROM
THE COAST FROM THE ERN GULF OF MEXICO AND COMBINE WITH ENERGY
CROSSING THE MIDDLE ATLANTIC REGION TUESDAY. THIS WILL PRODUCE
PCPN (MOSTLY SNOW) TUE-WED WITH TOTALS MOST LIKELY IN THE 2 TO 4
INCH RANGE IN MOST AREAS. THESE TOTALS ALIGN WITH THE LATEST WWD
TOTALS. SEVERAL FACTORS COULD CREATE DIFFERENT TOTALS...NAMELY THE
STORM DEVELOPING SOONER OR COMING CLOSER TO THE NJ COAST. PAY
ATTENTION TO FUTURE FCSTS FOR THE LATEST. THE LATEST MODELS STILL
SHOW THE HEAVIEST PCPN MOVING JUST EAST OF THE AREA TUE
NIGHT...WITH THE ERN PART OF NJ GETTING THE BRUNT OF THE HEAVY
PCPN FOR 6-8 HRS.
COLD AND WINDY CONDITIONS WED/WED NIGHT BEHIND THE DEPARTING
STORM. HIGHS MOSTLY IN THE 30S WED WITH W/NW WINDS GUSTING TO
30-35 MPH AT TIMES. TH WINDS SUBSIDE LATER WED NIGHT AS HIGH
PRESSURE BUILDS IN. LOWS WED NIGHT IN THE 20S WITH SOME TEENS FAR
NORTH.
THU/THU NIGHT...STRONG HIGH PRESSURE BUILDS ACROSS THE AREA THEN
MOVES EAST. MODERATING TEMPERATURES THU...BUT STILL SEVERAL
DEGREES BELOW NORMAL. HIGHS MOSTLY LOW 40S NORTH AND MID/UPPER 40S
SOUTH. FAIR WEATHER EXPECTED.
FRI THRU SAT...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE GREAT
LAKES AND SRN CANADA. A SRLY FLOW OF INCREASINGLY HUMID AIR ARRIVES
FRI WITH INCREASING CHC FOR SHOWERS FRI NIGHT/SAT. TEMPERATURES
WILL BE ABOVE NORMAL WITH HIGHS MOSTLY IN THE 60S BOTH FRI AND
SAT.
SUN...A RETURN TO FAIR WEATHER FORESEEN WITH TEMPERATURES ABOVE
NORMAL.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THIS AFTERNOON - TONIGHT...VFR. BRISK NORTHWEST WINDS AROUND 12
KNOTS WITH WIDESPREAD GUSTS DEVELOPING LATE THIS EVENING. STILL
THINK THAT THE RAIN WILL REMAIN SOUTH OF OUR TERMINALS THIS EVENING,
THOUGH THE CLOSEST TERMINAL TO SEE ANY IMPACTS WOULD BE ACY...BRIEF
MVFR SHOWER POSSIBLE. OTHERWISE WE WILL CLEAR OUT FROM NORTH TO
SOUTH WITH NORTHWEST WINDS.
TOMORROW...VFR. HIGH PRESSURE IN PLACE AND MORE GUSTY NORTHWEST
WINDS EXPECTED. THE GUSTS SHOULD BE TAPERING OFF BY THE LATE
AFTERNOON AS THE CENTER OF THE HIGH MOVES OVERHEAD. EXPECTING MOSTLY
CLEAR SKIES.
OUTLOOK...
MON NIGHT...MOSTLY VFR.
TUE THRU WED MORNING...MOSTLY IFR/MVFR WITH LOW CIGS/SNOW/GUSTY WINDS.
LATER WED INTO THU...MOSTLY VFR.
&&
.MARINE...
WINDS AND SEAS SHOULD BE BELOW SCA CRITERIA TODAY. BUT, WE ARE
EXPECTING THEM TO INCREASE TONIGHT AFTER THE CDFNTL PASSAGE
AND THERE IS BETTER MIXING AS COLDER AIR MOVES OVER THE AREA WATERS.
THEREFORE, A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR ALL OF THE
AREA WATERS. THE START TIME IS TO THE CATCH THE NORTHERN AREA WATERS
WIND UPTICK FIRST. WILL MENTION THIS IN THE MWW. THERE IS ALSO THE
CHANCE OF LIGHT FREEZING SPRAY LATE.
OUTLOOK...
MONDAY...SCA CONDITIONS EARLY WILL SUBSIDE BY EVENING.
MON NIGHT...SUB-SCA CONDITIONS.
TUE-WED...WINDS INCREASE STEADILY TUE WILL PROBABLY REACH GALE
CRITERIA BY TUE NIGHT AND PERSIST INTO WED.
WED NIGHT...WINDS/SEAS SUBSIDE BACK BELOW SCA CRITERIA LATE WED
NIGHT.
THU/THU NIGHT...SUB-SCA CONDITIONS. WINDS AND SEAS INCREASE LATE
THU NIGHT.
&&
.TIDES/COASTAL FLOODING...
THE LATEST ESTOFS STORM SURGE TIDE GUIDANCE DOES NOT PREDICT
MINOR TIDAL FLOODING CONDITIONS...BUT IT DOES COME CLOSE. THE
HIGH TIDE CYCLES LATE TUESDAY IS THE ONE THE COME CLOSEST TO
FLOODING. KEEP IN MIND THAT THE GFS GUIDANCE THAT THE ESTOFS IS BASED
ON IS NOT THE FCST THAT WE ARE GOING WITH...SINCE WE HAVE TENDED
TO FAVOR THE ECMWF SOLUTION THAT BRINGS THE LOW A BIT CLOSER TO
THE SHORE...SO THERE IS STILL A POSSIBILITY OF SOME MINOR TIDAL
FLOODING. TRACK AND INTENSIFICATION UNCERTAINTY WILL REMAIN FOR A
WHILE...SO COASTAL MUNICIPALITIES ARE ADVISED TO LOOK FOR UPDATES
IN THE DAYS AHEAD AS A CLOSER TO THE COAST TRACK WOULD INCREASE
THE RISK OF GREATER COASTAL FLOODING.
&&
.CLIMATE...
HERE ARE THE DAILY RECORD SNOWFALL AT OUR CLIMO BIG 4:
MARCH 25TH MARCH 26TH
ATLANTIC CITY 2.0 IN 2013 0.1 IN 2001
PHILADELPHIA 1.7 IN 1965 0.8 IN 2001
WILMINGTON 1.2 IN 1965 0.7 IN 2001
ALLENTOWN 1.5 IN 1934 2.0 IN 1933
AS A POINT OF CLIMATOLOGICAL REFERENCE. PHILADELPHIA HAS HAD
TEN 3 INCH OR GREATER SNOW EVENTS AFTER MARCH 24TH.
THE LAST OCCURRED ON MARCH 31ST TO APRIL 1ST OF 1997 AS
3.9 INCHES FELL. THE GREATEST WAS 19.4 INCHES ON APRIL
3RD AND 4TH OF 1915.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 10 AM EDT
MONDAY FOR ANZ450>455.
SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 10 AM EDT
MONDAY FOR ANZ430-431.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...GIGI/HEAVENER
SHORT TERM...GIGI
LONG TERM...O`HARA
AVIATION...HEAVENER/O`HARA
MARINE...GIGI/O`HARA
TIDES/COASTAL FLOODING...
CLIMATE...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
947 AM EDT SUN MAR 23 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TODAY. HIGH PRESSURE FROM THE UPPER
GREAT LAKES WILL BUILD OVER OUR AREA MONDAY AND MONDAY NIGHT AND
THEN MOVE EAST. A LOW PRESSURE SYSTEM WILL DEVELOP IN THE EASTERN
GULF OF MEXICO LATE MONDAY AND THEN TRACK TO THE NORTHEAST,
INTENSIFYING AS IT MOVES TO THE EAST OF THE AREA ON TUESDAY NIGHT.
HIGH PRESSURE WILL BUILD INTO THE REGION THROUGH THURSDAY BEFORE
PUSHING OFFSHORE. ANOTHER LOW PRESSURE SYSTEM WILL PASS TO THE NORTH
OF THE AREA, DRAGGING A COLD FRONT THROUGH ON FRIDAY NIGHT INTO
SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SEEMS AS THOUGH THE LATEST RAP/SREF/HRRR HAVE THE BEST HANDLE ON
THE NORTHWARD EXTENT OF THE PRECIPITATION FALLING ACROSS SW
VIRGINA AT THIS TIME. THAT BEING SAID HAVE INCREASED POPS EVEN
FURTHER ACROSS OUR SOUTHERN DELMARVA ZONES INTO THE LIKELY
SPECTRUM AND SLOWED THE DEPARTURE OF THE MID-LEVEL WAVE BY AN HOUR
OR SO. TEMPERATURES LOOK GOOD AT THIS POINT SO ONLY MADE A FEW
ADJUSTMENTS TO THEM.
OTHERWISE, THE GFS INITIALIZATION AT 500MB LOOKED SLIGHTLY BETTER
THAN THE WRF-NMMB. UP IN NORTHERN CANADA AND ALASKA, NOT THAT
THEIR 00Z SOLUTION OUTCOMES WERE COLLABORATIVE, THE GFS AND ECMWF
INITIALIZATIONS WERE CLOSE. THE REX HIGH IS SLIGHTLY STRONGER OVER
ALASKA THAN INITIALIZED AND THE IMPLICATION WOULD BE THAT THE LAST
PIECE OF THE PUZZLE, THE SHORT WAVE ENTERING NORTHWEST TERRITORY
AND NUNAVUT BORDER IS COMING IN SLIGHTLY HOTTER THAN INITIALIZED.
THE NEXT SOUNDING RUN SHOULD FINALLY HAVE A BETTER CAPTURE AND
LAND BASED RAOB SAMPLING OF THIS FEATURE. CLOSER TO HOME THE GFS
LOOKED SLIGHTLY WARMER AND BETTER AT 850MB AND 925MB WITH ITS
INITIALIZATION AND WAS USED MORE SO TODAY.
SECONDARY FRONT WAS CLEARLY SHOWING ON THE 925MB AND 850MB ANALYSES
ALONG THE MI AND CANADIAN BORDER. THIS SECOND BOUNDARY HAS OPENED
THE DOOR FOR POPS SOUTH AS WAVES ARE FORMING ON THE FRONT AND THE
FRONT ITSELF IS STALLING. THE FORCING THAT THERE IS WITHIN OUR CWA
IS EXTREMELY HI BASED (FGEN FORCING AND ISENTROPIC LIFT CENTERED
AROUND 600MB) WITH NO FCST MID LEVEL WAA THIS FAR NORTH. PLENTY OF
DRY AIR BELOW IT. THE FCST MID LEVEL QVEC CONVERGENCE IS OUTPACING
THE MOISTURE AND THE MOISTURE IS OUTPACING THE DPVA. THE NET RESULT
IS NOT MUCH PCPN IN OUR CWA, EVEN THOUGH MEASURABLE HAS TRENDED
NORTHWARD FROM LAST NIGHT.
LOOKING AT MODELING VERIFICATION, IN SPITE OF THE SLIGHTLY WEAKER
INITIALIZATION, THE WRF-NMMB VERIFIED THE BEST AT 06Z WITH ITS QPF
VS REALITY IN THE LOWER MS VLY. OUR MEASURABLE POPS ARE VERY CLOSE
TO THE OP WRF-NMMB AND RAP COMBO, GENERALLY CLOSER TO THE .05"
ISOHYET ON THE GLOBAL MODELS. GIVEN THAT THEY ARE ALREADY TOO LOW,
WRF-NMMB 2M TEMPS NOT USED AND WE SIDED WITH THE WARMER GFS MAV
GUIDANCE TODAY. GIVEN THIS AND THE LIGHT PCPN INTENSITY, PTYPE SOUTH
ALL RAIN. WE DID KEEP THE CHANCE OF FLURRIES FAR NW AS THE FRONT
APPROACHES.
TEMPS CONTINUE TO OUTPERFORM STAT GUIDANCE, BUT TODAY WE ARE
CONCERNED THAT MAYBE CLOUDINESS WILL ASSIST AND WE DID NOT GO ABOVE
GFS MOS. CWA IN A SEMI-COLISH SPOT WRT PRESSURE GRADIENT, SO NOT A
WINDY DAY AS YESTERDAY BECAME ONCE THE SUN BROKE OUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
WE KEPT LOW CHANCE POPS IN THRU 23Z SOUTH IN LINE WITH LATEST RAP.
THEN AS THE SECONDARY COLD FRONT COMES THRU, WE SHOULD HAVE A WIND
PICK-UP DURING THE EVENING INTO THE EARLY OVERNIGHT. THE WRF-NMMB
STARTS TRAPPING MOISTURE UNDERNEATH THE DEVELOPING SUBSIDENCE
INVERSION. ATTM WHILE THERE IS SOME CAA SC, IT DOES NOT APPEAR TO BE
SOLID. WE CONTINUE TO SIDE CLOSER TO THE MORE OPTIMISTIC GFS AND
ECMWF SKY SOLUTIONS. MIN TEMPS A STAT GUIDANCE BLEND. GIVEN THE CAA
AND THE THERMAL TROF PEAKING AT 12Z, EXPECT A SLIGHTLY LATER THAN
USUAL MORNING MIN ON MONDAY.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGH PRESSURE WILL BE ACROSS THE REGION MONDAY AND MONDAY NIGHT.
DRY WEATHER WITH BELOW NORMAL TEMPERATURES EXPECTED. THE HIGHS
MONDAY WILL ONLY BE IN THE LOW/MID 30S IN MOST AREAS WITH SOME
UPPER 20S FAR NORTH. THESE READINGS ARE SOME 10 TO 15 DEGREES
BELOW AVERAGE FOR MID/LATE MARCH. A VERY DRY AIR MASS WILL BE IN
PLACE WITH DEW POINTS IN THE SINGLE DIGITS AND SOME SUB-ZERO DEW
POINTS DURING THE AFTERNOON.
A COMPLEX SYSTEM WILL CAUSE A DEEP LOW PRESSURE SYSTEM TO BOMB OFF
THE EAST COAST TUE NIGHT INTO WED. LOW PRESSURE WILL MOVE UP FROM
THE COAST FROM THE ERN GULF OF MEXICO AND COMBINE WITH ENERGY
CROSSING THE MIDDLE ATLANTIC REGION TUESDAY. THIS WILL PRODUCE
PCPN (MOSTLY SNOW) TUE-WED WITH TOTALS MOST LIKELY IN THE 2 TO 4
INCH RANGE IN MOST AREAS. THESE TOTALS ALIGN WITH THE LATEST WWD
TOTALS. SEVERAL FACTORS COULD CREATE DIFFERENT TOTALS...NAMELY THE
STORM DEVELOPING SOONER OR COMING CLOSER TO THE NJ COAST. PAY
ATTENTION TO FUTURE FCSTS FOR THE LATEST. THE LATEST MODELS STILL
SHOW THE HEAVIEST PCPN MOVING JUST EAST OF THE AREA TUE
NIGHT...WITH THE ERN PART OF NJ GETTING THE BRUNT OF THE HEAVY
PCPN FOR 6-8 HRS.
COLD AND WINDY CONDITIONS WED/WED NIGHT BEHIND THE DEPARTING
STORM. HIGHS MOSTLY IN THE 30S WED WITH W/NW WINDS GUSTING TO
30-35 MPH AT TIMES. TH WINDS SUBSIDE LATER WED NIGHT AS HIGH
PRESSURE BUILDS IN. LOWS WED NIGHT IN THE 20S WITH SOME TEENS FAR
NORTH.
THU/THU NIGHT...STRONG HIGH PRESSURE BUILDS ACROSS THE AREA THEN
MOVES EAST. MODERATING TEMPERATURES THU...BUT STILL SEVERAL
DEGREES BELOW NORMAL. HIGHS MOSTLY LOW 40S NORTH AND MID/UPPER 40S
SOUTH. FAIR WEATHER EXPECTED.
FRI THRU SAT...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE GREAT
LAKES AND SRN CANADA. A SRLY FLOW OF INCREASINGLY HUMID AIR ARRIVES
FRI WITH INCREASING CHC FOR SHOWERS FRI NIGHT/SAT. TEMPERATURES
WILL BE ABOVE NORMAL WITH HIGHS MOSTLY IN THE 60S BOTH FRI AND
SAT.
SUN...A RETURN TO FAIR WEATHER FORESEEN WITH TEMPERATURES ABOVE
NORMAL.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
PLANS FOR THE 12Z TAF PACKAGE SHOULD CONTINUE VFR FORECASTS.
LOWEST CONFIDENCE AT KACY AND KMIV AND THERE MIGHT BE SOME MVFR
CIGS SOUTH OF THE TERMINALS THIS AFTERNOON/EARLY THIS EVENING.
THIS MORNING VFR CIG FORECAST TO LOWER MORE COMFORTABLY INTO AC
LEVEL. A STRATOCU VFR CIG POSSIBLE AT KABE AND KRDG EARLY. NORTHWEST
WINDS AROUND 10 KNOTS.
THIS AFTERNOON FROM THE KPHL AREA AIRPORTS/TERMINALS SOUTHEAST WE
HAVE KEPT A STRATOCU LEVEL VFR CIG IN THE TAFS. PCPN ALONG THE
STALLED FRONT MIGHT MAKE IT TO KACY AND KMIV, BUT CONFIDENCE AND
INHERENT IMPACTS TOO LOW TO STILL INCLUDE. FARTHER NORTHWEST
CONTINUED HIGHER BASED VFR CIG. NORTHWEST WINDS 10 TO 15 KNOTS.
THIS EVENING, SECONDARY CFP MOVES THROUGH. WINDS VEER MORE TO THE
NORTH WITH SIMILAR TO AFTERNOON SUSTAINED SPEEDS, BUT GUSTS
REACHING AROUND 20 KNOTS. VFR STRATOCU CIG MIGHT LINGER AT KMIV
AND KACY, REST OF TERMINALS WE ARE NOT FORECASTING A CIG.
INTO THE OVERNIGHT. SOME GUSTINESS MIGHT CONTINUE AT WINDIER
TERMINALS, BUT SKIES BY THEN SHOULD BE CLEAR OR MOSTLY CLEAR.
OUTLOOK...
MON/MON NIGHT...MOSTLY VFR.
TUE THRU WED MORNING...MOSTLY IFR/MVFR WITH LOW CIGS/SNOW/GUSTY WINDS.
LATER WED INTO THU...MOSTLY VFR.
&&
.MARINE...
WINDS AND SEAS SHOULD BE BELOW SCA CRITERIA TODAY. BUT, WE ARE
EXPECTING THEM TO INCREASE TONIGHT AFTER THE CDFNTL PASSAGE
AND THERE IS BETTER MIXING AS COLDER AIR MOVES OVER THE AREA WATERS.
THEREFORE, A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR ALL OF THE
AREA WATERS. THE START TIME IS TO THE CATCH THE NORTHERN AREA WATERS
WIND UPTICK FIRST. WILL MENTION THIS IN THE MWW. THERE IS ALSO THE
CHANCE OF LIGHT FREEZING SPRAY LATE.
OUTLOOK...
MONDAY...SCA CONDITIONS EARLY WILL SUBSIDE BY EVENING.
MON NIGHT...SUB-SCA CONDITIONS.
TUE-WED...WINDS INCREASE STEADILY TUE WILL PROBABLY REACH GALE
CRITERIA BY TUE NIGHT AND PERSIST INTO WED.
WED NIGHT...WINDS/SEAS SUBSIDE BACK BELOW SCA CRITERIA LATE WED
NIGHT.
THU/THU NIGHT...SUB-SCA CONDITIONS. WINDS AND SEAS INCREASE LATE
THU NIGHT.
&&
.TIDES/COASTAL FLOODING...
THE LATEST ESTOFS STORM SURGE TIDE GUIDANCE DOES NOT PREDICT
MINOR TIDAL FLOODING CONDITIONS...BUT IT DOES COME CLOSE. THE
HIGH TIDE CYCLES LATE TUESDAY IS THE ONE THE COME CLOSEST TO
FLOODING. KEEP IN MIND THAT THE GFS GUIDANCE THAT THE ESTOFS IS BASED
ON IS NOT THE FCST THAT WE ARE GOING WITH...SINCE WE HAVE TENDED
TO FAVOR THE ECMWF SOLUTION THAT BRINGS THE LOW A BIT CLOSER TO
THE SHORE...SO THERE IS STILL A POSSIBILITY OF SOME MINOR TIDAL
FLOODING. TRACK AND INTENSIFICATION UNCERTAINTY WILL REMAIN FOR A
WHILE...SO COASTAL MUNICIPALITIES ARE ADVISED TO LOOK FOR UPDATES
IN THE DAYS AHEAD AS A CLOSER TO THE COAST TRACK WOULD INCREASE
THE RISK OF GREATER COASTAL FLOODING.
&&
.CLIMATE...
HERE ARE THE DAILY RECORD SNOWFALL AT OUR CLIMO BIG 4:
MARCH 25TH MARCH 26TH
ATLANTIC CITY 2.0 IN 2013 0.1 IN 2001
PHILADELPHIA 1.7 IN 1965 0.8 IN 2001
WILMINGTON 1.2 IN 1965 0.7 IN 2001
ALLENTOWN 1.5 IN 1934 2.0 IN 1933
AS A POINT OF CLIMATOLOGICAL REFERENCE. PHILADELPHIA HAS HAD
TEN 3 INCH OR GREATER SNOW EVENTS AFTER MARCH 24TH.
THE LAST OCCURRED ON MARCH 31ST TO APRIL 1ST OF 1997 AS
3.9 INCHES FELL. THE GREATEST WAS 19.4 INCHES ON APRIL
3RD AND 4TH OF 1915.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 10 AM EDT
MONDAY FOR ANZ450>455.
SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 10 AM EDT
MONDAY FOR ANZ430-431.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...GIGI/HEAVENER
SHORT TERM...GIGI
LONG TERM...O`HARA
AVIATION...GIGI/O`HARA
MARINE...GIGI/O`HARA
TIDES/COASTAL FLOODING...
CLIMATE...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
645 AM EDT SUN MAR 23 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TODAY. HIGH PRESSURE FROM THE UPPER
GREAT LAKES WILL BUILD OVER OUR AREA MONDAY AND MONDAY NIGHT AND
THEN MOVE EAST. A LOW PRESSURE SYSTEM WILL DEVELOP IN THE EASTERN
GULF OF MEXICO LATE MONDAY AND THEN TRACK TO THE NORTHEAST,
INTENSIFYING AS IT MOVES TO THE EAST OF THE AREA ON TUESDAY NIGHT.
HIGH PRESSURE WILL BUILD INTO THE REGION THROUGH THURSDAY BEFORE
PUSHING OFFSHORE. ANOTHER LOW PRESSURE SYSTEM WILL PASS TO THE NORTH
OF THE AREA, DRAGGING A COLD FRONT THROUGH ON FRIDAY NIGHT INTO
SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST ESTF UPDATE MAINLY TO ADJUST GRIDS TO CURRENT OBS AND
TRENDS. WE DID ADJUST POPS UPWARD IN OUR FAR SRN CWA BASED ON THE
LATEST 06Z GFS AND WRF-NMMB. MEASURABLE POPS NOW A BLEND OF THE
LATEST RAP AND THE FORMER MODELS. THE NORTHERN EDGE OF MEASURABLE
WITH THE LATTER MODELS IS STILL NOT VERIFYING.
THE GFS INITIALIZATION AT 500MB LOOKED SLIGHTLY BETTER THAN THE
WRF-NMMB. UP IN NORTHERN CANADA AND ALASKA, NOT THAT THEIR 00Z
SOLUTION OUTCOMES WERE COLLABORATIVE, THE GFS AND ECMWF
INITIALIZATIONS WERE CLOSE. THE REX HIGH IS SLIGHTLY STRONGER OVER
ALASKA THAN INITIALIZED AND THE IMPLICATION WOULD BE THAT THE LAST
PIECE OF THE PUZZLE, THE SHORT WAVE ENTERING NORTHWEST TERRITORY AND
NUNAVUT BORDER IS COMING IN SLIGHTLY HOTTER THAN INITIALIZED. THE
NEXT SOUNDING RUN SHOULD FINALLY HAVE A BETTER CAPTURE AND LAND
BASED RAOB SAMPLING OF THIS FEATURE. CLOSER TO HOME THE GFS LOOKED
SLIGHTLY WARMER AND BETTER AT 850MB AND 925MB WITH ITS
INITIALIZATION AND WAS USED MORE SO TODAY.
SECONDARY FRONT WAS CLEARLY SHOWING ON THE 925MB AND 850MB ANALYSES
ALONG THE MI AND CANADIAN BORDER. THIS SECOND BOUNDARY HAS OPENED
THE DOOR FOR POPS SOUTH AS WAVES ARE FORMING ON THE FRONT AND THE
FRONT ITSELF IS STALLING. THE FORCING THAT THERE IS WITHIN OUR CWA
IS EXTREMELY HI BASED (FGEN FORCING AND ISENTROPIC LIFT CENTERED
AROUND 600MB) WITH NO FCST MID LEVEL WAA THIS FAR NORTH. PLENTY OF
DRY AIR BELOW IT. THE FCST MID LEVEL QVEC CONVERGENCE IS OUTPACING
THE MOISTURE AND THE MOISTURE IS OUTPACING THE DPVA. THE NET RESULT
IS NOT MUCH PCPN IN OUR CWA, EVEN THOUGH MEASURABLE HAS TRENDED
NORTHWARD FROM LAST NIGHT.
LOOKING AT MODELING VERIFICATION, IN SPITE OF THE SLIGHTLY WEAKER
INITIALIZATION, THE WRF-NMMB VERIFIED THE BEST AT 06Z WITH ITS QPF
VS REALITY IN THE LOWER MS VLY. OUR MEASURABLE POPS ARE VERY CLOSE
TO THE OP WRF-NMMB AND RAP COMBO, GENERALLY CLOSER TO THE .05"
ISOHYET ON THE GLOBAL MODELS. GIVEN THAT THEY ARE ALREADY TOO LOW,
WRF-NMMB 2M TEMPS NOT USED AND WE SIDED WITH THE WARMER GFS MAV
GUIDANCE TODAY. GIVEN THIS AND THE LIGHT PCPN INTENSITY, PTYPE SOUTH
ALL RAIN. WE DID KEEP THE CHANCE OF FLURRIES FAR NW AS THE FRONT
APPROACHES.
TEMPS CONTINUE TO OUTPERFORM STAT GUIDANCE, BUT TODAY WE ARE
CONCERNED THAT MAYBE CLOUDINESS WILL ASSIST AND WE DID NOT GO ABOVE
GFS MOS. CWA IN A SEMI-COLISH SPOT WRT PRESSURE GRADIENT, SO NOT A
WINDY DAY AS YESTERDAY BECAME ONCE THE SUN BROKE OUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
WE KEPT LOW CHANCE POPS IN THRU 23Z SOUTH IN LINE WITH LATEST RAP.
THEN AS THE SECONDARY COLD FRONT COMES THRU, WE SHOULD HAVE A WIND
PICK-UP DURING THE EVENING INTO THE EARLY OVERNIGHT. THE WRF-NMMB
STARTS TRAPPING MOISTURE UNDERNEATH THE DEVELOPING SUBSIDENCE
INVERSION. ATTM WHILE THERE IS SOME CAA SC, IT DOES NOT APPEAR TO BE
SOLID. WE CONTINUE TO SIDE CLOSER TO THE MORE OPTIMISTIC GFS AND
ECMWF SKY SOLUTIONS. MIN TEMPS A STAT GUIDANCE BLEND. GIVEN THE CAA
AND THE THERMAL TROF PEAKING AT 12Z, EXPECT A SLIGHTLY LATER THAN
USUAL MORNING MIN ON MONDAY.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGH PRESSURE WILL BE ACROSS THE REGION MONDAY AND MONDAY NIGHT.
DRY WEATHER WITH BELOW NORMAL TEMPERATURES EXPECTED. THE HIGHS
MONDAY WILL ONLY BE IN THE LOW/MID 30S IN MOST AREAS WITH SOME
UPPER 20S FAR NORTH. THESE READINGS ARE SOME 10 TO 15 DEGREES
BELOW AVERAGE FOR MID/LATE MARCH. A VERY DRY AIR MASS WILL BE IN
PLACE WITH DEW POINTS IN THE SINGLE DIGITS AND SOME SUB-ZERO DEW
POINTS DURING THE AFTERNOON.
A COMPLEX SYSTEM WILL CAUSE A DEEP LOW PRESSURE SYSTEM TO BOMB OFF
THE EAST COAST TUE NIGHT INTO WED. LOW PRESSURE WILL MOVE UP FROM
THE COAST FROM THE ERN GULF OF MEXICO AND COMBINE WITH ENERGY
CROSSING THE MIDDLE ATLANTIC REGION TUESDAY. THIS WILL PRODUCE
PCPN (MOSTLY SNOW) TUE-WED WITH TOTALS MOST LIKELY IN THE 2 TO 4
INCH RANGE IN MOST AREAS. THESE TOTALS ALIGN WITH THE LATEST WWD
TOTALS. SEVERAL FACTORS COULD CREATE DIFFERENT TOTALS...NAMELY THE
STORM DEVELOPING SOONER OR COMING CLOSER TO THE NJ COAST. PAY
ATTENTION TO FUTURE FCSTS FOR THE LATEST. THE LATEST MODELS STILL
SHOW THE HEAVIEST PCPN MOVING JUST EAST OF THE AREA TUE
NIGHT...WITH THE ERN PART OF NJ GETTING THE BRUNT OF THE HEAVY
PCPN FOR 6-8 HRS.
COLD AND WINDY CONDITIONS WED/WED NIGHT BEHIND THE DEPARTING
STORM. HIGHS MOSTLY IN THE 30S WED WITH W/NW WINDS GUSTING TO
30-35 MPH AT TIMES. TH WINDS SUBSIDE LATER WED NIGHT AS HIGH
PRESSURE BUILDS IN. LOWS WED NIGHT IN THE 20S WITH SOME TEENS FAR
NORTH.
THU/THU NIGHT...STRONG HIGH PRESSURE BUILDS ACROSS THE AREA THEN
MOVES EAST. MODERATING TEMPERATURES THU...BUT STILL SEVERAL
DEGREES BELOW NORMAL. HIGHS MOSTLY LOW 40S NORTH AND MID/UPPER 40S
SOUTH. FAIR WEATHER EXPECTED.
FRI THRU SAT...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE GREAT
LAKES AND SRN CANADA. A SRLY FLOW OF INCREASINGLY HUMID AIR ARRIVES
FRI WITH INCREASING CHC FOR SHOWERS FRI NIGHT/SAT. TEMPERATURES
WILL BE ABOVE NORMAL WITH HIGHS MOSTLY IN THE 60S BOTH FRI AND
SAT.
SUN...A RETURN TO FAIR WEATHER FORESEEN WITH TEMPERATURES ABOVE
NORMAL.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
PLANS FOR THE 12Z TAF PACKAGE SHOULD CONTINUE VFR FORECASTS.
LOWEST CONFIDENCE AT KACY AND KMIV AND THERE MIGHT BE SOME MVFR
CIGS SOUTH OF THE TERMINALS THIS AFTERNOON/EARLY THIS EVENING.
THIS MORNING VFR CIG FORECAST TO LOWER MORE COMFORTABLY INTO AC
LEVEL. A STRATOCU VFR CIG POSSIBLE AT KABE AND KRDG EARLY. NORTHWEST
WINDS AROUND 10 KNOTS.
THIS AFTERNOON FROM THE KPHL AREA AIRPORTS/TERMINALS SOUTHEAST WE
HAVE KEPT A STRATOCU LEVEL VFR CIG IN THE TAFS. PCPN ALONG THE
STALLED FRONT MIGHT MAKE IT TO KACY AND KMIV, BUT CONFIDENCE AND
INHERENT IMPACTS TOO LOW TO STILL INCLUDE. FARTHER NORTHWEST
CONTINUED HIGHER BASED VFR CIG. NORTHWEST WINDS 10 TO 15 KNOTS.
THIS EVENING, SECONDARY CFP MOVES THROUGH. WINDS VEER MORE TO THE
NORTH WITH SIMILAR TO AFTERNOON SUSTAINED SPEEDS, BUT GUSTS
REACHING AROUND 20 KNOTS. VFR STRATOCU CIG MIGHT LINGER AT KMIV
AND KACY, REST OF TERMINALS WE ARE NOT FORECASTING A CIG.
INTO THE OVERNIGHT. SOME GUSTINESS MIGHT CONTINUE AT WINDIER
TERMINALS, BUT SKIES BY THEN SHOULD BE CLEAR OR MOSTLY CLEAR.
OUTLOOK...
MON/MON NIGHT...MOSTLY VFR.
TUE THRU WED MORNING...MOSTLY IFR/MVFR WITH LOW CIGS/SNOW/GUSTY WINDS.
LATER WED INTO THU...MOSTLY VFR.
&&
.MARINE...
WINDS AND SEAS SHOULD BE BELOW SCA CRITERIA TODAY. BUT, WE ARE
EXPECTING THEM TO INCREASE TONIGHT AFTER THE CDFNTL PASSAGE
AND THERE IS BETTER MIXING AS COLDER AIR MOVES OVER THE AREA WATERS.
THEREFORE, A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR ALL OF THE
AREA WATERS. THE START TIME IS TO THE CATCH THE NORTHERN AREA WATERS
WIND UPTICK FIRST. WILL MENTION THIS IN THE MWW. THERE IS ALSO THE
CHANCE OF LIGHT FREEZING SPRAY LATE.
OUTLOOK...
MONDAY...SCA CONDITIONS EARLY WILL SUBSIDE BY EVENING.
MON NIGHT...SUB-SCA CONDITIONS.
TUE-WED...WINDS INCREASE STEADILY TUE WILL PROBABLY REACH GALE
CRITERIA BY TUE NIGHT AND PERSIST INTO WED.
WED NIGHT...WINDS/SEAS SUBSIDE BACK BELOW SCA CRITERIA LATE WED
NIGHT.
THU/THU NIGHT...SUB-SCA CONDITIONS. WINDS AND SEAS INCREASE LATE
THU NIGHT.
&&
.TIDES/COASTAL FLOODING...
THE LATEST ESTOFS STORM SURGE TIDE GUIDANCE DOES NOT PREDICT
MINOR TIDAL FLOODING CONDITIONS...BUT IT DOES COME CLOSE. THE
HIGH TIDE CYCLES LATE TUESDAY IS THE ONE THE COME CLOSEST TO
FLOODING. KEEP IN MIND THAT THE GFS GUIDANCE THAT THE ESTOFS IS BASED
ON IS NOT THE FCST THAT WE ARE GOING WITH...SINCE WE HAVE TENDED
TO FAVOR THE ECMWF SOLUTION THAT BRINGS THE LOW A BIT CLOSER TO
THE SHORE...SO THERE IS STILL A POSSIBILITY OF SOME MINOR TIDAL
FLOODING. TRACK AND INTENSIFICATION UNCERTAINTY WILL REMAIN FOR A
WHILE...SO COASTAL MUNICIPALITIES ARE ADVISED TO LOOK FOR UPDATES
IN THE DAYS AHEAD AS A CLOSER TO THE COAST TRACK WOULD INCREASE
THE RISK OF GREATER COASTAL FLOODING.
&&
.CLIMATE...
HERE ARE THE DAILY RECORD SNOWFALL AT OUR CLIMO BIG 4:
MARCH 25TH MARCH 26TH
ATLANTIC CITY 2.0 IN 2013 0.1 IN 2001
PHILADELPHIA 1.7 IN 1965 0.8 IN 2001
WILMINGTON 1.2 IN 1965 0.7 IN 2001
ALLENTOWN 1.5 IN 1934 2.0 IN 1933
AS A POINT OF CLIMATOLOGICAL REFERENCE. PHILADELPHIA HAS HAD
TEN 3 INCH OR GREATER SNOW EVENTS AFTER MARCH 24TH.
THE LAST OCCURRED ON MARCH 31ST TO APRIL 1ST OF 1997 AS
3.9 INCHES FELL. THE GREATEST WAS 19.4 INCHES ON APRIL
3RD AND 4TH OF 1915.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 10 AM EDT
MONDAY FOR ANZ450>455.
SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 10 AM EDT
MONDAY FOR ANZ430-431.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...GIGI
SHORT TERM...GIGI
LONG TERM...O`HARA
AVIATION...GIGI/O`HARA
MARINE...GIGI/O`HARA
TIDES/COASTAL FLOODING...
CLIMATE...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
640 AM EDT SUN MAR 23 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TODAY. HIGH PRESSURE FROM THE UPPER
GREAT LAKES WILL BUILD OVER OUR AREA MONDAY AND MONDAY NIGHT AND
THEN MOVE EAST. A LOW PRESSURE SYSTEM WILL DEVELOP IN THE EASTERN
GULF OF MEXICO LATE MONDAY AND THEN TRACK TO THE NORTHEAST,
INTENSIFYING AS IT MOVES TO THE EAST OF THE AREA ON TUESDAY NIGHT.
HIGH PRESSURE WILL BUILD INTO THE REGION THROUGH THURSDAY BEFORE
PUSHING OFFSHORE. ANOTHER LOW PRESSURE SYSTEM WILL PASS TO THE NORTH
OF THE AREA, DRAGGING A COLD FRONT THROUGH ON FRIDAY NIGHT INTO
SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST ESTF UPDATE MAINLY TO ADJUST GRIDS TO CURRENT OBS AND
TRENDS. WE DID ADJUST POPS UPWARD IN OUR FAR SRN CWA BASED ON THE
LATEST 06Z GFS AND WRF-NMMB. MEASURABLE POPS NOW A BLEND OF THE
LATEST RAP AND THE FORMER MODELS. THE NORTHERN EDGE OF MEASURABLE
WITH THE LATTER MODELS IS STILL NOT VERIFYING.
THE GFS INITIALIZATION AT 500MB LOOKED SLIGHTLY BETTER THAN THE
WRF-NMMB. UP IN NORTHERN CANADA AND ALASKA, NOT THAT THEIR 00Z
SOLUTION OUTCOMES WERE COLLABORATIVE, THE GFS AND ECMWF
INITIALIZATIONS WERE CLOSE. THE REX HIGH IS SLIGHTLY STRONGER OVER
ALASKA THAN INITIALIZED AND THE IMPLICATION WOULD BE THAT THE LAST
PIECE OF THE PUZZLE, THE SHORT WAVE ENTERING NORTHWEST TERRITORY AND
NUNAVUT BORDER IS COMING IN SLIGHTLY HOTTER THAN INITIALIZED. THE
NEXT SOUNDING RUN SHOULD FINALLY HAVE A BETTER CAPTURE AND LAND
BASED RAOB SAMPLING OF THIS FEATURE. CLOSER TO HOME THE GFS LOOKED
SLIGHTLY WARMER AND BETTER AT 850MB AND 925MB WITH ITS
INITIALIZATION AND WAS USED MORE SO TODAY.
SECONDARY FRONT WAS CLEARLY SHOWING ON THE 925MB AND 850MB ANALYSES
ALONG THE MI AND CANADIAN BORDER. THIS SECOND BOUNDARY HAS OPENED
THE DOOR FOR POPS SOUTH AS WAVES ARE FORMING ON THE FRONT AND THE
FRONT ITSELF IS STALLING. THE FORCING THAT THERE IS WITHIN OUR CWA
IS EXTREMELY HI BASED (FGEN FORCING AND ISENTROPIC LIFT CENTERED
AROUND 600MB) WITH NO FCST MID LEVEL WAA THIS FAR NORTH. PLENTY OF
DRY AIR BELOW IT. THE FCST MID LEVEL QVEC CONVERGENCE IS OUTPACING
THE MOISTURE AND THE MOISTURE IS OUTPACING THE DPVA. THE NET RESULT
IS NOT MUCH PCPN IN OUR CWA, EVEN THOUGH MEASURABLE HAS TRENDED
NORTHWARD FROM LAST NIGHT.
LOOKING AT MODELING VERIFICATION, IN SPITE OF THE SLIGHTLY WEAKER
INITIALIZATION, THE WRF-NMMB VERIFIED THE BEST AT 06Z WITH ITS QPF
VS REALITY IN THE LOWER MS VLY. OUR MEASURABLE POPS ARE VERY CLOSE
TO THE OP WRF-NMMB AND RAP COMBO, GENERALLY CLOSER TO THE .05"
ISOHYET ON THE GLOBAL MODELS. GIVEN THAT THEY ARE ALREADY TOO LOW,
WRF-NMMB 2M TEMPS NOT USED AND WE SIDED WITH THE WARMER GFS MAV
GUIDANCE TODAY. GIVEN THIS AND THE LIGHT PCPN INTENSITY, PTYPE SOUTH
ALL RAIN. WE DID KEEP THE CHANCE OF FLURRIES FAR NW AS THE FRONT
APPROACHES.
TEMPS CONTINUE TO OUTPERFORM STAT GUIDANCE, BUT TODAY WE ARE
CONCERNED THAT MAYBE CLOUDINESS WILL ASSIST AND WE DID NOT GO ABOVE
GFS MOS. CWA IN A SEMI-COLISH SPOT WRT PRESSURE GRADIENT, SO NOT A
WINDY DAY AS YESTERDAY BECAME ONCE THE SUN BROKE OUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
WE KEPT LOW CHANCE POPS IN THRU 23Z SOUTH IN LINE WITH LATEST RAP.
THEN AS THE SECONDARY COLD FRONT COMES THRU, WE SHOULD HAVE A WIND
PICK-UP DURING THE EVENING INTO THE EARLY OVERNIGHT. THE WRF-NMMB
STARTS TRAPPING MOISTURE UNDERNEATH THE DEVELOPING SUBSIDENCE
INVERSION. ATTM WHILE THERE IS SOME CAA SC, IT DOES NOT APPEAR TO BE
SOLID. WE CONTINUE TO SIDE CLOSER TO THE MORE OPTIMISTIC GFS AND
ECMWF SKY SOLUTIONS. MIN TEMPS A STAT GUIDANCE BLEND. GIVEN THE CAA
AND THE THERMAL TROF PEAKING AT 12Z, EXPECT A SLIGHTLY LATER THAN
USUAL MORNING MIN ON MONDAY.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGH PRESSURE WILL BE ACROSS THE REGION MONDAY AND MONDAY NIGHT.
DRY WEATHER WITH BELOW NORMAL TEMPERATURES EXPECTED. THE HIGHS
MONDAY WILL ONLY BE IN THE LOW/MID 30S IN MOST AREAS WITH SOME
UPPER 20S FAR NORTH. THESE READINGS ARE SOME 10 TO 15 DEGREES
BELOW AVERAGE FOR MID/LATE MARCH. A VERY DRY AIR MASS WILL BE IN
PLACE WITH DEW POINTS IN THE SINGLE DIGITS AND SOME SUB-ZERO DEW
POINTS DURING THE AFTERNOON.
A COMPLEX SYSTEM WILL CAUSE A DEEP LOW PRESSURE SYSTEM TO BOMB OFF
THE EAST COAST TUE NIGHT INTO WED. LOW PRESSURE WILL MOVE UP FROM
THE COAST FROM THE ERN GULF OF MEXICO AND COMBINE WITH ENERGY
CROSSING THE MIDDLE ATLANTIC REGION TUESDAY. THIS WILL PRODUCE
PCPN (MOSTLY SNOW) TUE-WED WITH TOTALS MOST LIKELY IN THE 2 TO 4
INCH RANGE IN MOST AREAS. THESE TOTALS ALIGN WITH THE LATEST WWD
TOTALS. SEVERAL FACTORS COULD CREATE DIFFERENT TOTALS...NAMELY THE
STORM DEVELOPING SOONER OR COMING CLOSER TO THE NJ COAST. PAY
ATTENTION TO FUTURE FCSTS FOR THE LATEST. THE LATEST MODELS STILL
SHOW THE HEAVIEST PCPN MOVING JUST EAST OF THE AREA TUE
NIGHT...WITH THE ERN PART OF NJ GETTING THE BRUNT OF THE HEAVY
PCPN FOR 6-8 HRS.
COLD AND WINDY CONDITIONS WED/WED NIGHT BEHIND THE DEPARTING
STORM. HIGHS MOSTLY IN THE 30S WED WITH W/NW WINDS GUSTING TO
30-35 MPH AT TIMES. TH WINDS SUBSIDE LATER WED NIGHT AS HIGH
PRESSURE BUILDS IN. LOWS WED NIGHT IN THE 20S WITH SOME TEENS FAR
NORTH.
THU/THU NIGHT...STRONG HIGH PRESSURE BUILDS ACROSS THE AREA THEN
MOVES EAST. MODERATING TEMPERATURES THU...BUT STILL SEVERAL
DEGREES BELOW NORMAL. HIGHS MOSTLY LOW 40S NORTH AND MID/UPPER 40S
SOUTH. FAIR WEATHER EXPECTED.
FRI THRU SAT...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE GREAT
LAKES AND SRN CANADA. A SRLY FLOW OF INCREASINGLY HUMID AIR ARRIVES
FRI WITH INCREASING CHC FOR SHOWERS FRI NIGHT/SAT. TEMPERATURES
WILL BE ABOVE NORMAL WITH HIGHS MOSTLY IN THE 60S BOTH FRI AND
SAT.
SUN...A RETURN TO FAIR WEATHER FORESEEN WITH TEMPERATURES ABOVE
NORMAL.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
PLANS FOR THE 12Z TAF PACKAGE SHOULD CONTINUE VFR FORECASTS.
LOWEST CONFIDENCE AT KACY AND KMIV AND THERE MIGHT BE SOME MVFR
CIGS SOUTH OF THE TERMINALS THIS AFTERNOON/EARLY THIS EVENING.
THIS MORNING VFR CIG FORECAST TO LOWER MORE COMFORTABLY INTO AC
LEVEL. A STRATOCU VFR CIG POSSIBLE AT KABE AND KRDG EARLY. NORTHWEST
WINDS AROUND 10 KNOTS.
THIS AFTERNOON FROM THE KPHL AREA AIRPORTS/TERMINALS SOUTHEAST WE
HAVE KEPT A STRATOCU LEVEL VFR CIG IN THE TAFS. PCPN ALONG THE
STALLED FRONT MIGHT MAKE IT TO KACY AND KMIV, BUT CONFIDENCE AND
INHERENT IMPACTS TOO LOW TO STILL INCLUDE. FARTHER NORTHWEST
CONTINUED HIGHER BASED VFR CIG. NORTHWEST WINDS 10 TO 15 KNOTS.
THIS EVENING, SECONDARY CFP MOVES THROUGH. WINDS VEER MORE TO THE
NORTH WITH SIMILAR TO AFTERNOON SUSTAINED SPEEDS, BUT GUSTS
REACHING AROUND 20 KNOTS. VFR STRATOCU CIG MIGHT LINGER AT KMIV
AND KACY, REST OF TERMINALS WE ARE NOT FORECASTING A CIG.
INTO THE OVERNIGHT. SOME GUSTINESS MIGHT CONTINUE AT WINDIER
TERMINALS, BUT SKIES BY THEN SHOULD BE CLEAR OR MOSTLY CLEAR.
OUTLOOK...
MON/MON NIGHT...MOSTLY VFR.
TUE THRU WED MORNING...MOSTLY IFR/MVFR WITH LOW CIGS/SNOW/GUSTY WINDS.
LATER WED INTO THU...MOSTLY VFR.
&&
.MARINE...
WINDS AND SEAS SHOULD BE BELOW SCA CRITERIA TODAY. BUT, WE ARE
EXPECTING THEM TO INCREASE TONIGHT AFTER THE CDFNTL PASSAGE
AND THERE IS BETTER MIXING AS COLDER AIR MOVES OVER THE AREA WATERS.
THEREFORE, A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR ALL OF THE
AREA WATERS. THE START TIME IS TO THE CATCH THE NORTHERN AREA WATERS
WIND UPTICK FIRST. WILL MENTION THIS IN THE MWW.
OUTLOOK...
MONDAY...SCA CONDITIONS EARLY WILL SUBSIDE BY EVENING.
MON NIGHT...SUB-SCA CONDITIONS.
TUE-WED...WINDS INCREASE STEADILY TUE WILL PROBABLY REACH GALE
CRITERIA BY TUE NIGHT AND PERSIST INTO WED.
WED NIGHT...WINDS/SEAS SUBSIDE BACK BELOW SCA CRITERIA LATE WED
NIGHT.
THU/THU NIGHT...SUB-SCA CONDITIONS. WINDS AND SEAS INCREASE LATE
THU NIGHT.
&&
.TIDES/COASTAL FLOODING...
THE LATEST ESTOFS STORM SURGE TIDE GUIDANCE DOES NOT PREDICT
MINOR TIDAL FLOODING CONDITIONS...BUT IT DOES COME CLOSE. THE
HIGH TIDE CYCLES LATE TUESDAY IS THE ONE THE COME CLOSEST TO
FLOODING. KEEP IN MIND THAT THE GFS GUIDANCE THAT THE ESTOFS IS BASED
ON IS NOT THE FCST THAT WE ARE GOING WITH...SINCE WE HAVE TENDED
TO FAVOR THE ECMWF SOLUTION THAT BRINGS THE LOW A BIT CLOSER TO
THE SHORE...SO THERE IS STILL A POSSIBILITY OF SOME MINOR TIDAL
FLOODING. TRACK AND INTENSIFICATION UNCERTAINTY WILL REMAIN FOR A
WHILE...SO COASTAL MUNICIPALITIES ARE ADVISED TO LOOK FOR UPDATES
IN THE DAYS AHEAD AS A CLOSER TO THE COAST TRACK WOULD INCREASE
THE RISK OF GREATER COASTAL FLOODING.
&&
.CLIMATE...
HERE ARE THE DAILY RECORD SNOWFALL AT OUR CLIMO BIG 4:
MARCH 25TH MARCH 26TH
ATLANTIC CITY 2.0 IN 2013 0.1 IN 2001
PHILADELPHIA 1.7 IN 1965 0.8 IN 2001
WILMINGTON 1.2 IN 1965 0.7 IN 2001
ALLENTOWN 1.5 IN 1934 2.0 IN 1933
AS A POINT OF CLIMATOLOGICAL REFERENCE. PHILADELPHIA HAS HAD
TEN 3 INCH OR GREATER SNOW EVENTS AFTER MARCH 24TH.
THE LAST OCCURRED ON MARCH 31ST TO APRIL 1ST OF 1997 AS
3.9 INCHES FELL. THE GREATEST WAS 19.4 INCHES ON APRIL
3RD AND 4TH OF 1915.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 10 AM EDT
MONDAY FOR ANZ450>455.
SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 10 AM EDT
MONDAY FOR ANZ430-431.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...GIGI
SHORT TERM...GIGI
LONG TERM...O`HARA
AVIATION...GIGI/O`HARA
MARINE...GIGI/O`HARA
TIDES/COASTAL FLOODING...
CLIMATE...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
628 AM EDT SUN MAR 23 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TODAY. HIGH PRESSURE FROM THE UPPER
GREAT LAKES WILL BUILD OVER OUR AREA MONDAY AND MONDAY NIGHT AND
THEN MOVE EAST. A LOW PRESSURE SYSTEM WILL DEVELOP IN THE EASTERN
GULF OF MEXICO LATE MONDAY AND THEN TRACK TO THE NORTHEAST,
INTENSIFYING AS IT MOVES TO THE EAST OF THE AREA ON TUESDAY NIGHT.
HIGH PRESSURE WILL BUILD INTO THE REGION THROUGH THURSDAY BEFORE
PUSHING OFFSHORE. ANOTHER LOW PRESSURE SYSTEM WILL PASS TO THE NORTH
OF THE AREA, DRAGGING A COLD FRONT THROUGH ON FRIDAY NIGHT INTO
SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST ESTF UPDATE MAINLY TO ADJUST GRIDS TO CURRENT OBS AND
TRENDS. WE DID ADJUST POPS UPWARD IN OUR FAR SRN CWA BASED ON THE
LATEST 06Z GFS AND WRF-NMMB. MEASURABLE POPS NOW A BLEND OF THE
LATEST RAP AND THE FORMER MODELS. THE NORTHERN EDGE OF MEASURABLE
WITH THE LATTER MODELS IS STILL NOT VERIFYING.
THE GFS INITIALIZATION AT 500MB LOOKED SLIGHTLY BETTER THAN THE
WRF-NMMB. UP IN NORTHERN CANADA AND ALASKA, NOT THAT THEIR 00Z
SOLUTION OUTCOMES WERE COLLABORATIVE, THE GFS AND ECMWF
INITIALIZATIONS WERE CLOSE. THE REX HIGH IS SLIGHTLY STRONGER OVER
ALASKA THAN INITIALIZED AND THE IMPLICATION WOULD BE THAT THE LAST
PIECE OF THE PUZZLE, THE SHORT WAVE ENTERING NORTHWEST TERRITORY AND
NUNAVUT BORDER IS COMING IN SLIGHTLY HOTTER THAN INITIALIZED. THE
NEXT SOUNDING RUN SHOULD FINALLY HAVE A BETTER CAPTURE AND LAND
BASED RAOB SAMPLING OF THIS FEATURE. CLOSER TO HOME THE GFS LOOKED
SLIGHTLY WARMER AND BETTER AT 850MB AND 925MB WITH ITS
INITIALIZATION AND WAS USED MORE SO TODAY.
SECONDARY FRONT WAS CLEARLY SHOWING ON THE 925MB AND 850MB ANALYSES
ALONG THE MI AND CANADIAN BORDER. THIS SECOND BOUNDARY HAS OPENED
THE DOOR FOR POPS SOUTH AS WAVES ARE FORMING ON THE FRONT AND THE
FRONT ITSELF IS STALLING. THE FORCING THAT THERE IS WITHIN OUR CWA
IS EXTREMELY HI BASED (FGEN FORCING AND ISENTROPIC LIFT CENTERED
AROUND 600MB) WITH NO FCST MID LEVEL WAA THIS FAR NORTH. PLENTY OF
DRY AIR BELOW IT. THE FCST MID LEVEL QVEC CONVERGENCE IS OUTPACING
THE MOISTURE AND THE MOISTURE IS OUTPACING THE DPVA. THE NET RESULT
IS NOT MUCH PCPN IN OUR CWA, EVEN THOUGH MEASURABLE HAS TRENDED
NORTHWARD FROM LAST NIGHT.
LOOKING AT MODELING VERIFICATION, IN SPITE OF THE SLIGHTLY WEAKER
INITIALIZATION, THE WRF-NMMB VERIFIED THE BEST AT 06Z WITH ITS QPF
VS REALITY IN THE LOWER MS VLY. OUR MEASURABLE POPS ARE VERY CLOSE
TO THE OP WRF-NMMB AND RAP COMBO, GENERALLY CLOSER TO THE .05"
ISOHYET ON THE GLOBAL MODELS. GIVEN THAT THEY ARE ALREADY TOO LOW,
WRF-NMMB 2M TEMPS NOT USED AND WE SIDED WITH THE WARMER GFS MAV
GUIDANCE TODAY. GIVEN THIS AND THE LIGHT PCPN INTENSITY, PTYPE SOUTH
ALL RAIN. WE DID KEEP THE CHANCE OF FLURRIES FAR NW AS THE FRONT
APPROACHES.
TEMPS CONTINUE TO OUTPERFORM STAT GUIDANCE, BUT TODAY WE ARE
CONCERNED THAT MAYBE CLOUDINESS WILL ASSIST AND WE DID NOT GO ABOVE
GFS MOS. CWA IN A SEMI-COLISH SPOT WRT PRESSURE GRADIENT, SO NOT A
WINDY DAY AS YESTERDAY BECAME ONCE THE SUN BROKE OUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
WE KEPT LOW CHANCE POPS IN THRU 23Z SOUTH IN LINE WITH LATEST RAP.
THEN AS THE SECONDARY COLD FRONT COMES THRU, WE SHOULD HAVE A WIND
PICK-UP DURING THE EVENING INTO THE EARLY OVERNIGHT. THE WRF-NMMB
STARTS TRAPPING MOISTURE UNDERNEATH THE DEVELOPING SUBSIDENCE
INVERSION. ATTM WHILE THERE IS SOME CAA SC, IT DOES NOT APPEAR TO BE
SOLID. WE CONTINUE TO SIDE CLOSER TO THE MORE OPTIMISTIC GFS AND
ECMWF SKY SOLUTIONS. MIN TEMPS A STAT GUIDANCE BLEND. GIVEN THE CAA
AND THE THERMAL TROF PEAKING AT 12Z, EXPECT A SLIGHTLY LATER THAN
USUAL MORNING MIN ON MONDAY.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGH PRESSURE WILL BE ACROSS THE REGION MONDAY AND MONDAY NIGHT.
DRY WEATHER WITH BELOW NORMAL TEMPERATURES EXPECTED. THE HIGHS
MONDAY WILL ONLY BE IN THE LOW/MID 30S IN MOST AREAS WITH SOME
UPPER 20S FAR NORTH. THESE READINGS ARE SOME 10 TO 15 DEGREES
BELOW AVERAGE FOR MID/LATE MARCH. A VERY DRY AIR MASS WILL BE IN
PLACE WITH DEW POINTS IN THE SINGLE DIGITS AND SOME SUB-ZERO DEW
POINTS DURING THE AFTERNOON.
A COMPLEX SYSTEM WILL CAUSE A DEEP LOW PRESSURE SYSTEM TO BOMB OFF
THE EAST COAST TUE NIGHT INTO WED. LOW PRESSURE WILL MOVE UP FROM
THE COAST FROM THE ERN GULF OF MEXICO AND COMBINE WITH ENERGY
CROSSING THE MIDDLE ATLANTIC REGION TUESDAY. THIS WILL PRODUCE
PCPN (MOSTLY SNOW) TUE-WED WITH TOTALS MOST LIKELY IN THE 2 TO 4
INCH RANGE IN MOST AREAS. THESE TOTALS ALIGN WITH THE LATEST WWD
TOTALS. SEVERAL FACTORS COULD CREATE DIFFERENT TOTALS...NAMELY THE
STORM DEVELOPING SOONER OR COMING CLOSER TO THE NJ COAST. PAY
ATTENTION TO FUTURE FCSTS FOR THE LATEST. THE LATEST MODELS STILL
SHOW THE HEAVIEST PCPN MOVING JUST EAST OF THE AREA TUE
NIGHT...WITH THE ERN PART OF NJ GETTING THE BRUNT OF THE HEAVY
PCPN FOR 6-8 HRS.
COLD AND WINDY CONDITIONS WED/WED NIGHT BEHIND THE DEPARTING
STORM. HIGHS MOSTLY IN THE 30S WED WITH W/NW WINDS GUSTING TO
30-35 MPH AT TIMES. TH WINDS SUBSIDE LATER WED NIGHT AS HIGH
PRESSURE BUILDS IN. LOWS WED NIGHT IN THE 20S WITH SOME TEENS FAR
NORTH.
THU/THU NIGHT...STRONG HIGH PRESSURE BUILDS ACROSS THE AREA THEN
MOVES EAST. MODERATING TEMPERATURES THU...BUT STILL SEVERAL
DEGREES BELOW NORMAL. HIGHS MOSTLY LOW 40S NORTH AND MID/UPPER 40S
SOUTH. FAIR WEATHER EXPECTED.
FRI THRU SAT...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE GREAT
LAKES AND SRN CANADA. A SRLY FLOW OF INCREASINGLY HUMID AIR ARRIVES
FRI WITH INCREASING CHC FOR SHOWERS FRI NIGHT/SAT. TEMPERATURES
WILL BE ABOVE NORMAL WITH HIGHS MOSTLY IN THE 60S BOTH FRI AND
SAT.
SUN...A RETURN TO FAIR WEATHER FORESEEN WITH TEMPERATURES ABOVE
NORMAL.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
PLANS FOR THE 12Z TAF PACKAGE SHOULD CONTINUE VFR FORECASTS.
LOWEST CONFIDENCE AT KACY AND KMIV AND THERE MIGHT BE SOME MVFR
CIGS SOUTH OF THE TERMINALS THIS AFTERNOON/EARLY THIS EVENING.
THIS MORNING VFR CIG FORECAST TO LOWER MORE COMFORTABLY INTO AC
LEVEL. A STRATOCU VFR CIG POSSIBLE AT KABE AND KRDG EARLY. NORTHWEST
WINDS AROUND 10 KNOTS.
THIS AFTERNOON FROM THE KPHL AREA AIRPORTS/TERMINALS SOUTHEAST WE
HAVE KEPT A STRATOCU LEVEL VFR CIG IN THE TAFS. PCPN ALONG THE
STALLED FRONT MIGHT MAKE IT TO KACY AND KMIV, BUT CONFIDENCE AND
INHERENT IMPACTS TOO LOW TO STILL INCLUDE. FARTHER NORTHWEST
CONTINUED HIGHER BASED VFR CIG. NORTHWEST WINDS 10 TO 15 KNOTS.
THIS EVENING, SECONDARY CFP MOVES THROUGH. WINDS VEER MORE TO THE
NORTH WITH SIMILAR TO AFTERNOON SUSTAINED SPEEDS, BUT GUSTS
REACHING AROUND 20 KNOTS. VFR STRATOCU CIG MIGHT LINGER AT KMIV
AND KACY, REST OF TERMINALS WE ARE NOT FORECASTING A CIG.
INTO THE OVERNIGHT. SOME GUSTINESS MIGHT CONTINUE AT WINDIER
TERMINALS, BUT SKIES BY THEN SHOULD BE CLEAR OR MOSTLY CLEAR.
OUTLOOK...
MON/MON NIGHT...MOSTLY VFR.
TUE THRU WED MORNING...MOSTLY IFR/MVFR WITH LOW CIGS/SNOW/GUSTY WINDS.
LATER WED INTO THU...MOSTLY VFR.
&&
.MARINE...
WINDS AND SEAS SHOULD BE BELOW SCA CRITERIA TODAY. BUT, WE ARE
EXPECTING THEM TO INCREASE TONIGHT AFTER THE CDFNTL PASSAGE
AND THERE IS BETTER MIXING AS COLDER AIR MOVES OVER THE AREA WATERS.
THEREFORE, A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR ALL OF THE
AREA WATERS. THE START TIME IS TO THE CATCH THE NORTHERN AREA WATERS
WIND UPTICK FIRST. WILL MENTION THIS IN THE MWW.
OUTLOOK...
MONDAY...SCA CONDITIONS EARLY WILL SUBSIDE BY EVENING.
MON NIGHT...SUB-SCA CONDITIONS.
TUE-WED...WINDS INCREASE STEADILY TUE WILL PROBABLY REACH GALE
CRITERIA BY TUE NIGHT AND PERSIST INTO WED.
WED NIGHT...WINDS/SEAS SUBSIDE BACK BELOW SCA CRITERIA LATE WED
NIGHT.
THU/THU NIGHT...SUB-SCA CONDITIONS. WINDS AND SEAS INCREASE LATE
THU NIGHT.
&&
.TIDES/COASTAL FLOODING...
THE LATEST ESTOFS STORM SURGE TIDE GUIDANCE DOES NOT PREDICT
MINOR TIDAL FLOODING CONDITIONS...BUT IT DOES COME CLOSE. THE
HIGH TIDE CYCLES LATE TUESDAY IS THE ONE THE COME CLOSEST TO
FLOODING. KEEP IN MIND THAT THE GFS GUIDANCE THAT THE ESTOFS IS BASED
ON IS NOT THE FCST THAT WE ARE GOING WITH...SINCE WE HAVE TENDED
TO FAVOR THE ECMWF SOLUTION THAT BRINGS THE LOW A BIT CLOSER TO
THE SHORE...SO THERE IS STILL A POSSIBILITY OF SOME MINOR TIDAL
FLOODING. TRACK AND INTENSIFICATION UNCERTAINTY WILL REMAIN FOR A
WHILE...SO COASTAL MUNICIPALITIES ARE ADVISED TO LOOK FOR UPDATES
IN THE DAYS AHEAD AS A CLOSER TO THE COAST TRACK WOULD INCREASE
THE RISK OF GREATER COASTAL FLOODING.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 10 AM EDT
MONDAY FOR ANZ450>455.
SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 10 AM EDT
MONDAY FOR ANZ430-431.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...GIGI
SHORT TERM...GIGI
LONG TERM...O`HARA
AVIATION...GIGI/O`HARA
MARINE...GIGI/O`HARA
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
346 AM EDT SUN MAR 23 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TODAY. HIGH PRESSURE FROM THE UPPER
GREAT LAKES WILL BUILD OVER OUR AREA MONDAY AND MONDAY NIGHT AND
THEN MOVE EAST. A LOW PRESSURE SYSTEM WILL DEVELOP IN THE EASTERN
GULF OF MEXICO LATE MONDAY AND THEN TRACK TO THE NORTHEAST,
INTENSIFYING AS IT MOVES TO THE EAST OF THE AREA ON TUESDAY NIGHT.
HIGH PRESSURE WILL BUILD INTO THE REGION THROUGH THURSDAY BEFORE
PUSHING OFFSHORE. ANOTHER LOW PRESSURE SYSTEM WILL PASS TO THE NORTH
OF THE AREA, DRAGGING A COLD FRONT THROUGH ON FRIDAY NIGHT INTO
SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE GFS INITIALIZATION AT 500MB LOOKED SLIGHTLY BETTER THAN THE
WRF-NMMB. UP IN NORTHERN CANADA AND ALASKA, NOT THAT THEIR 00Z
SOLUTION OUTCOMES WERE COLLABORATIVE, THE GFS AND ECMWF
INITIALIZATIONS WERE CLOSE. THE REX HIGH IS SLIGHTLY STRONGER OVER
ALASKA THAN INITIALIZED AND THE IMPLICATION WOULD BE THAT THE LAST
PIECE OF THE PUZZLE, THE SHORT WAVE ENTERING NORTHWEST TERRITORY AND
NUNAVUT BORDER IS COMING IN SLIGHTLY HOTTER THAN INITIALIZED. THE
NEXT SOUNDING RUN SHOULD FINALLY HAVE A BETTER CAPTURE AND LAND
BASED RAOB SAMPLING OF THIS FEATURE. CLOSER TO HOME THE GFS LOOKED
SLIGHTLY WARMER AND BETTER AT 850MB AND 925MB WITH ITS
INITIALIZATION AND WAS USED MORE SO TODAY.
SECONDARY FRONT WAS CLEARLY SHOWING ON THE 925MB AND 850MB ANALYSES
ALONG THE MI AND CANADIAN BORDER. THIS SECOND BOUNDARY HAS OPENED
THE DOOR FOR POPS SOUTH AS WAVES ARE FORMING ON THE FRONT AND THE
FRONT ITSELF IS STALLING. THE FORCING THAT THERE IS WITHIN OUR CWA
IS EXTREMELY HI BASED (FGEN FORCING AND ISENTROPIC LIFT CENTERED
AROUND 600MB) WITH NO FCST MID LEVEL WAA THIS FAR NORTH. PLENTY OF
DRY AIR BELOW IT. THE FCST MID LEVEL QVEC CONVERGENCE IS OUTPACING
THE MOISTURE AND THE MOISTURE IS OUTPACING THE DPVA. THE NET RESULT
IS NOT MUCH PCPN IN OUR CWA, EVEN THOUGH MEASURABLE HAS TRENDED
NORTHWARD FROM LAST NIGHT.
LOOKING AT MODELING VERIFICATION, IN SPITE OF THE SLIGHTLY WEAKER
INITIALIZATION, THE WRF-NMMB VERIFIED THE BEST AT 06Z WITH ITS QPF
VS REALITY IN THE LOWER MS VLY. OUR MEASURABLE POPS ARE VERY CLOSE
TO THE OP WRF-NMMB AND RAP COMBO, GENERALLY CLOSER TO THE .05"
ISOHYET ON THE GLOBAL MODELS. GIVEN THAT THEY ARE ALREADY TOO LOW,
WRF-NMMB 2M TEMPS NOT USED AND WE SIDED WITH THE WARMER GFS MAV
GUIDANCE TODAY. GIVEN THIS AND THE LIGHT PCPN INTENSITY, PTYPE SOUTH
ALL RAIN. WE DID KEEP THE CHANCE OF FLURRIES FAR NW AS THE FRONT
APPROACHES.
TEMPS CONTINUE TO OUTPERFORM STAT GUIDANCE, BUT TODAY WE ARE
CONCERNED THAT MAYBE CLOUDINESS WILL ASSIST AND WE DID NOT GO ABOVE
GFS MOS. CWA IN A SEMI-COLISH SPOT WRT PRESSURE GRADIENT, SO NOT A
WINDY DAY AS YESTERDAY BECAME ONCE THE SUN BROKE OUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
WE KEPT LOW CHANCE POPS IN THRU 23Z SOUTH IN LINE WITH LATEST RAP.
THEN AS THE SECONDARY COLD FRONT COMES THRU, WE SHOULD HAVE A WIND
PICK-UP DURING THE EVENING INTO THE EARLY OVERNIGHT. THE WRF-NMMB
STARTS TRAPPING MOISTURE UNDERNEATH THE DEVELOPING SUBSIDENCE
INVERSION. ATTM WHILE THERE IS SOME CAA SC, IT DOES NOT APPEAR TO BE
SOLID. WE CONTINUE TO SIDE CLOSER TO THE MORE OPTIMISTIC GFS AND
ECMWF SKY SOLUTIONS. MIN TEMPS A STAT GUIDANCE BLEND. GIVEN THE CAA
AND THE THERMAL TROF PEAKING AT 12Z, EXPECT A SLIGHTLY LATER THAN
USUAL MORNING MIN ON MONDAY.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGH PRESSURE WILL BE ACROSS THE REGION MONDAY AND MONDAY NIGHT.
DRY WEATHER WITH BELOW NORMAL TEMPERATURES EXPECTED. THE HIGHS
MONDAY WILL ONLY BE IN THE LOW/MID 30S IN MOST AREAS WITH SOME
UPPER 20S FAR NORTH. THESE READINGS ARE SOME 10 TO 15 DEGREES
BELOW AVERAGE FOR MID/LATE MARCH. A VERY DRY AIR MASS WILL BE IN
PLACE WITH DEW POINTS IN THE SINGLE DIGITS AND SOME SUB-ZERO DEW
POINTS DURING THE AFTERNOON.
A COMPLEX SYSTEM WILL CAUSE A DEEP LOW PRESSURE SYSTEM TO BOMB OFF
THE EAST COAST TUE NIGHT INTO WED. LOW PRESSURE WILL MOVE UP FROM
THE COAST FROM THE ERN GULF OF MEXICO AND COMBINE WITH ENERGY
CROSSING THE MIDDLE ATLANTIC REGION TUESDAY. THIS WILL PRODUCE
PCPN (MOSTLY SNOW) TUE-WED WITH TOTALS MOST LIKELY IN THE 2 TO 4
INCH RANGE IN MOST AREAS. THESE TOTALS ALIGN WITH THE LATEST WWD
TOTALS. SEVERAL FACTORS COULD CREATE DIFFERENT TOTALS...NAMELY THE
STORM DEVELOPING SOONER OR COMING CLOSER TO THE NJ COAST. PAY
ATTENTION TO FUTURE FCSTS FOR THE LATEST. THE LATEST MODELS STILL
SHOW THE HEAVIEST PCPN MOVING JUST EAST OF THE AREA TUE
NIGHT...WITH THE ERN PART OF NJ GETTING THE BRUNT OF THE HEAVY
PCPN FOR 6-8 HRS.
COLD AND WINDY CONDITIONS WED/WED NIGHT BEHIND THE DEPARTING
STORM. HIGHS MOSTLY IN THE 30S WED WITH W/NW WINDS GUSTING TO
30-35 MPH AT TIMES. TH WINDS SUBSIDE LATER WED NIGHT AS HIGH
PRESSURE BUILDS IN. LOWS WED NIGHT IN THE 20S WITH SOME TEENS FAR
NORTH.
THU/THU NIGHT...STRONG HIGH PRESSURE BUILDS ACROSS THE AREA THEN
MOVES EAST. MODERATING TEMPERATURES THU...BUT STILL SEVERAL
DEGREES BELOW NORMAL. HIGHS MOSTLY LOW 40S NORTH AND MID/UPPER 40S
SOUTH. FAIR WEATHER EXPECTED.
FRI THRU SAT...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE GREAT
LAKES AND SRN CANADA. A SRLY FLOW OF INCREASINGLY HUMID AIR ARRIVES
FRI WITH INCREASING CHC FOR SHOWERS FRI NIGHT/SAT. TEMPERATURES
WILL BE ABOVE NORMAL WITH HIGHS MOSTLY IN THE 60S BOTH FRI AND
SAT.
SUN...A RETURN TO FAIR WEATHER FORESEEN WITH TEMPERATURES ABOVE
NORMAL.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE 06Z TAF PACKAGE CONTINUES VFR FORECASTS. THERE MIGHT BE SOME
MVFR CONDITIONS SOUTH OF THE TERMINALS IN DELMARVA LATE TODAY.
REST OF OVERNIGHT. SOME DECAYING VFR STRATOCU MIGHT MAKE IT INTO
KABE AND KRDG WITH A HIGHER BASED MID TO HIGH LEVEL CIG SPREADING
EAST. NORTHWEST WINDS LESS THAN 10 KTS.
THIS MORNING VFR CIG FORECAST TO LOWER MORE COMFORTABLY INTO AC
LEVEL. NORTHWEST WINDS SLIGHTLY STRONGER, AROUND 10 KNOTS.
THIS AFTERNOON FROM THE KPHL AREA AIRPORTS/TERMINALS SOUTHEAST WE
HAVE KEPT A STRATOCU LEVEL VFR CIG IN THE TAFS. PCPN ALONG THE
STALLED FRONT MIGHT MAKE IT CLOSE TO KACY AND KMIV, BUT CONFIDENCE
AND INHERENT IMPACTS TOO LOW TO INCLUDE. WILL REACCESS FOR 12Z TAFS.
FARTHER NORTHWEST CONTINUED HIGHER BASED VFR CIG. NORTHWEST WINDS
AROUND 10 KNOTS.
THIS EVENING, SECONDARY CFP MOVES THROUGH. WINDS VEER MORE TO THE
NORTH WITH SIMILAR TO AFTERNOON SUSTAINED SPEEDS, BUT GUSTS
REACHING AROUND 20 KNOTS. VFR STRATOCU CIG MIGHT LINGER AT KMIV
AND KACY, REST OF TERMINALS WE ARE NOT FORECASTING A CIG.
INTO THE OVERNIGHT. SOME GUSTINESS MIGHT CONTINUE AT WINDIER
TERMINALS, BUT SKIES BY THEN SHOULD BE CLEAR.
OUTLOOK...
MON/MON NIGHT...MOSTLY VFR.
TUE THRU WED MORNING...MOSTLY IFR/MVFR WITH LOW CIGS/SNOW/GUSTY WINDS.
LATER WED INTO THU...MOSTLY VFR.
&&
.MARINE...
WINDS AND SEAS SHOULD BE BELOW SCA CRITERIA TODAY. BUT, WE ARE
EXPECTING THEM TO INCREASE TONIGHT AFTER THE CDFNTL PASSAGE
AND THERE IS BETTER MIXING AS COLDER AIR MOVES OVER THE AREA WATERS.
THEREFORE, A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR ALL OF THE
AREA WATERS. THE START TIME IS TO THE CATCH THE NORTHERN AREA WATERS
WIND UPTICK FIRST. WILL MENTION THIS IN THE MWW.
OUTLOOK...
MONDAY...SCA CONDITIONS EARLY WILL SUBSIDE BY EVENING.
MON NIGHT...SUB-SCA CONDITIONS.
TUE-WED...WINDS INCREASE STEADILY TUE WILL PROBABLY REACH GALE
CRITERIA BY TUE NIGHT AND PERSIST INTO WED.
WED NIGHT...WINDS/SEAS SUBSIDE BACK BELOW SCA CRITERIA LATE WED
NIGHT.
THU/THU NIGHT...SUB-SCA CONDITIONS. WINDS AND SEAS INCREASE LATE
THU NIGHT.
&&
.TIDES/COASTAL FLOODING...
THE LATEST ESTOFS STORM SURGE TIDE GUIDANCE DOES NOT PREDICT
MINOR TIDAL FLOODING CONDITIONS...BUT IT DOES COME CLOSE. THE
HIGH TIDE CYCLES LATE TUESDAY IS THE ONE THE COME CLOSEST TO
FLOODING. KEEP IN MIND THAT THE GFS GUIDANCE THAT THE ESTOFS IS BASED
ON IS NOT THE FCST THAT WE ARE GOING WITH...SINCE WE HAVE TENDED
TO FAVOR THE ECMWF SOLUTION THAT BRINGS THE LOW A BIT CLOSER TO
THE SHORE...SO THERE IS STILL A POSSIBILITY OF SOME MINOR TIDAL
FLOODING. TRACK AND INTENSIFICATION UNCERTAINTY WILL REMAIN FOR A
WHILE...SO COASTAL MUNICIPALITIES ARE ADVISED TO LOOK FOR UPDATES
IN THE DAYS AHEAD AS A CLOSER TO THE COAST TRACK WOULD INCREASE
THE RISK OF GREATER COASTAL FLOODING.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 10 AM EDT
MONDAY FOR ANZ450>455.
SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 10 AM EDT
MONDAY FOR ANZ430-431.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...GIGI
SHORT TERM...GIGI
LONG TERM...O`HARA
AVIATION...GIGI/O`HARA
MARINE...GIGI/O`HARA
TIDES/COASTAL FLOODING...GIGI/O`HARA
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
926 PM EDT Mon Mar 24 2014
.Near Term [Through Tonight]...
Zonal flow aloft over the Southeast US will be replaced by a trough
digging into our region overnight into Tuesday morning. A large
surface high pressure system currently covers the Northern Plains
and the eastern half of the CONUS, with a stationary front stretching
from the Gulf of Mexico through central FL. Weak isentropic lift
did cause some light showers to develop over the Big Bend region
this afternoon, but these have already dissipated. Light easterly
flow will persist through at least 06Z under this pattern, with
limited moisture and forcing resulting in fairly low chances of
measurable precipitation during this time. From 06Z-12Z, a weak
surface low will likely develop over east central FL under the
right entrance region of a strengthening upper-level jet streak
and downstream of a trof digging through TX. This will bring a
slightly better chance of rain to our eastern counties at this
time, even though the best moisture and synoptic scale forcing
will remain just to our east and south through Tuesday morning. As
a result, did lower the PoPs slightly over our FL and GA counties
through 12Z as supported by the bulk of the Hi-Res Guidance
including the HRRR and CAM.
Near the end of the period, the pressure gradient will begin to
tighten between the high centered to our northwest and the
developing low moving off the east coast of FL, resulting in
northwesterly winds beginning to increase around 12Z Tuesday,
especially over AL counties. According to latest guidance and
considering overcast skies and lack of strong cold air advection,
decided to bump up low temperatures slightly over most inland
regions. Lows should range from the mid-40s in the NW corner of
our CWA to the upper 50s in coastal regions of the eastern Big
Bend.
&&
.Aviation...
[Through 00Z Wednesday] Although all sites are currently at VFR
conditions, expect MVFR to move in from the east by 02 UTC and
spread to the west. All sites, expect DHN, will reach MVFR levels
by 05 UTC with ceilings around 1500 ft. Near sunrise, IFR cigs are
likely at VLD. Conditions will improve from NW to SE across the
area on Tuesday. Winds will be around 15 knots from the NW
tomorrow afternoon, with gusts upwards of 20 knots possible,
especially at DHN and ABY. Shortly before 00 UTC, winds will begin
to decrease to around 10 knots.
&&
.Prev Discussion [331 PM EDT]...
.Short Term [Tuesday Through Wednesday Night]...
A potent shortwave rounding the base of a large east coast trough
will push any remaining showers out of our easternmost counties
around sunrise tomorrow. A cool and dry airmass will move into the
Southeast through the day, ushered in by gusty northwesterly winds
along the leading edge of high pressure. Gusts 25 to 30 mph will
be common on Tuesday.
The calm center of the ridge will slip into our northern counties
within a couple hours of sunrise Wednesday. The subsequent light
winds will allow temperatures to plummet during the latter half of
the night, possibly falling to below freezing for southeast
Alabama and most of our Georgia counties. Thus, a freeze watch has
been issued. In the outlooked area there also exists the potential
for patchy frost during the same time period, widespread frost is
not anticipated due to the relatively dry conditions. A frost
advisory may be necessary further south of the watch, but the
forecast is a little too uncertain at this time as to just how far
south the calm winds will spread, and just how moist the boundary
layer will be.
The cold dome of high pressure will remain in place across the
Southeast on Wednesday, severely limiting afternoon mixing. Even
under sunny conditions we will have to struggle to reach the 60s
area wide, with some locations possibly remaining in the upper
50s.
Wednesday night will be warmer than Tuesday as winds veer easterly
and increase. Lows should bottom out in the upper 30s and lower
40s area wide.
.Long Term [Thursday Through Monday]...
We`ll transition out of an unseasonably cool and dry pattern into
a wet pattern with more seasonable temperatures through the
extended range forecast. A frontal system will enter the Tri-State
region on Friday, and not completely clear out until sometime on
Sunday when conditions will begin to dry out once again.
.Marine...
On the leading edge of strong high pressure, winds will increase
to at least cautionary levels tomorrow with occasional higher
gusts. Winds will briefly fall back to below headline levels on
Wednesday, before increasing once again ahead of another frontal
system late in the week.
.Fire Weather...
A cold front will move through the region late tonight bringing in a
much cooler and drier airmass to the region on Tuesday. Relative
humidity values will approach critical levels Tuesday afternoon
across the tri-state area. It will also be breezy during the
afternoon hours, but the winds should not be strong enough to meet
criteria in Alabama or Georgia. In Florida, the ERC values will not
be high enough, thus will not need any headlines this cycle. Dry
conditions will continue into Wednesday, but with lighter winds,
criteria will not be met. The airmass will moisten into Thursday
putting an end to any fire weather concerns.
.Hydrology...
Most rivers across the region have crested and are slowly receding
with only a few points still above flood stage (Ochlockonee,
Aucilla and Withlacoochee). The exception is the the Suwannee
River, where stages continue to rise. However, the chance of
flooding along the Suwannee is low.
For the latest river stages and forecasts, please visit:
water.weather.gov/ahps2/index.php?wfo=tae
&&
.Preliminary Point Temps/PoPs...
Tallahassee 54 70 35 60 40 / 40 10 0 0 10
Panama City 53 68 41 60 48 / 30 10 0 0 10
Dothan 48 65 34 59 43 / 20 0 0 0 10
Albany 49 66 32 58 40 / 30 10 0 0 10
Valdosta 55 69 34 59 39 / 50 10 0 0 0
Cross City 57 72 37 62 37 / 60 10 0 0 10
Apalachicola 55 68 41 59 48 / 40 10 0 0 10
&&
.TAE Watches/Warnings/Advisories...
FL...None.
GA...Freeze Watch from late Tuesday night through Wednesday morning
for Baker-Ben Hill-Berrien-Calhoun-Clay-Colquitt-Cook-
Dougherty-Early-Irwin-Lee-Miller-Mitchell-Quitman-Randolph-
Terrell-Tift-Turner-Worth.
AL...Freeze Watch from late Tuesday night through Wednesday morning
for Coffee-Dale-Geneva-Henry-Houston.
GM...None.
&&
$$
NEAR TERM...LAHR/GOULD
SHORT TERM...HARRIGAN
LONG TERM...HARRIGAN
AVIATION...HELLER/BLOCK
MARINE...LAHR/HARRIGAN
FIRE WEATHER...GODSEY
HYDROLOGY...HOLLINGSWORTH
AREA FORECAST DISCUSSION...CORRECTED
NWS TAMPA BAY RUSKIN FL
425 PM EDT SUN MAR 23 2014
CORRECTED TO ADD MARINE SECTION
.SYNOPSIS...
20Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUES TO SHOW A MAINLY ZONAL
FLOW PATTERN OVER THE NORTHERN GULF OF MEXICO AND FLORIDA PENINSULA.
A FEW VERY WEAK IMPULSES ARE EMBEDDED WITHIN THIS FLOW AND WILL BE
CROSSING ALONG THE NORTHERN GULF COAST THE NEXT 24 HOURS. WE ARE
JUST NOW BEGINNING TO SEE THE FIRST WAVES OF ENERGY DROPPING
SOUTHWARD FROM WESTERN CANADA INTO THE NORTHERN ROCKIES/UPPER
MIDWEST WHICH WILL TRIGGER A SIGNIFICANT AMPLIFICATION TO THE UPPER
LEVEL PATTERN OVER THE EASTERN HALF OF THE NATION DURING THE FIRST
HALF OF THE WEEK. THIS AMPLIFICATION WILL EVENTUALLY BRING A STRONG
COLD FRONT THROUGH THE FORECAST AREA ON TUESDAY...BUT UNTIL THAT
TIME...CHANCES FOR SHOWERS WILL BE INCREASING WITH TIME AND
RESULTING IN WHAT APPEARS TO BE A DAMP PERIOD LATER MONDAY INTO
MONDAY NIGHT.
AT THE SURFACE...HIGH PRESSURE CONTINUES TO DROP SOUTH AND WEAKEN IN
RESPONSE TO THE APPROACH OF A WEAK COLD FRONT FROM THE NORTH. THIS
FRONT IS CURRENTLY UP OVER SOUTHERN GA/AL...AND WILL SLOWLY SETTLE
SOUTH TO A POSITION OVER CENTRAL/SOUTHERN FLORIDA BY MONDAY MORNING.
REGIONAL RADARS ARE CURRENTLY SHOWING A FEW SCT INSTABILITY SHOWERS
DEVELOPING ALONG THE SEA-BREEZE AND MOVING INLAND THIS AFTERNOON.
THIS ACTIVITY WILL CONTINUE TO MOVE INLAND AND DISSIPATE AS WE HEAD
INTO THE EVENING HOURS. A FEW MORE SCATTERED SHOWERS WILL BE HEADED
SOUTH ASSOCIATED WITH THE SURFACE FOCUS ALONG/AHEAD OF THE FRONT BY
LATER THIS EVENING.
&&
.SHORT TERM (TONIGHT THROUGH TUESDAY)...
TONIGHT...AS MENTIONED ABOVE...A WEAK SURFACE BOUNDARY WILL SLIP
SOUTH INTO THE PENINSULA THROUGH THE OVERNIGHT HOURS. OVERALL NOT
MUCH IN THE WAY OF LARGE SCALE SYNOPTIC FORCING FOR ASCENT IN THE
VICINITY OVERNIGHT...SO ONLY EXPECTING A FEW NUISANCE TYPE SHOWERS
ASSOCIATED WITH THIS FEATURE. RAIN CHANCES FOR THE TAMPA BAY AREA
NORTHWARD WILL GENERALLY BE IN THE THE 20-30% RANGE WITH ANY LIKELY
BEING LIGHT IN NATURE.
MONDAY/MONDAY NIGHT...WEAK BOUNDARY WILL STALL OUT OVER THE SOUTHERN
HALF OF THE AREAS ON MONDAY AND EXTEND OUT INTO THE EASTERN GULF OF
MEXICO. LIKELY WILL SEE QUITE A BIT OF CLOUDS ALREADY AROUND BY
MORNING...WITH A FEW SCT SHOWERS CONTINUING. AS THE DAY
PROGRESSES...GLOBAL MODELS ALL SHOW AN INCREASINGLY PROMINENT
ISENTROPIC UPGLIDE REGIME ALONG THE 290-300K SURFACES BECOMING
ESTABLISHED ALONG AND TO THE NORTH OF THE BOUNDARY. AT THE SAME
TIME...UPPER LEVEL DIVERGENCE ASSOCIATED WITH A JET CORE ALONG THE
NORTHERN GULF COAST WILL BE INCREASING TO AID THIS LOWER LEVEL LIFT.
THE OVERALL RESULT WILL BE GREATER COVERAGE OF SHOWERS AS THE
DAY PROGRESSES...WITH A RATHER WET SCENARIO LIKELY BY MONDAY EVENING
INTO MONDAY NIGHT. AS IT APPEARS NOW...THE BEST CHANCES FOR BREAKS
OF SUN DURING THE DAY ON MONDAY WILL BE OVER THE SOUTHERN ZONES
(CHARLOTTE/LEE COUNTIES) TO THE SOUTH OF THE FRONT. HOWEVER...ENOUGH
HEATING WILL ALLOW FOR SEA-BREEZE DEVELOPMENT. WITH SOME SYNOPTIC
FORCING IN PLACE...IT LIKELY WILL NOT TAKE MUCH SURFACE FOCUS TO GET
SOME SEA-BREEZE SHOWERS OR STORMS GOING FOR THE AFTERNOON.
THEREFORE...MOST AREAS TOMORROW SHOULD SEE SOME RAIN...WHETHER IT BE
FROM A STRATIFORM PROCESS NORTH...OR A CONVECTIVE PROCESS SOUTH.
TUESDAY...
LOTS OF SHOWERS LIKELY TO STILL BE AROUND TUESDAY MORNING...
ESPECIALLY FROM TAMPA BAY SOUTHWARD...AS THE UPPER LEVEL PATTERN
QUICKLY BEGINS TO AMPLIFY INTO THE EASTERN CONUS. THIS AMPLIFICATION
IS CURRENTLY PROGGED TO RESULT IN RAPID CYCLOGENESIS OFF THE
CAROLINA COAST THE SECOND HALF OF TUESDAY...AND THIS PROCESS ALONG
WITH THE PASSING UPPER TROUGH AXIS WILL HELP PROPEL A STRENGTHENING
COLD FRONT SOUTH OF OUR AREA...AND BEGIN TO DRY US OUT FROM THE
NORTH. BY LATE IN THE DAY ON TUESDAY...ALL SHOWERS SHOULD HAVE
ENDED...EVEN FOR THE FAR SOUTHERN ZONES...WITH A RATHER COOL AIRMASS
FOR LATE MARCH ARRIVING BY TUESDAY NIGHT.
&&
.LONG TERM (TUESDAY NIGHT-SUNDAY)...
MEDIUM RANGE GUIDANCE IN IN FAIRLY GOOD AGREEMENT SHOWING AN
UNSETTLED WEATHER PATTERN ACROSS THE REGION THROUGH THE LONG TERM
PERIOD. AT THE BEGINNING OF THE PERIOD HOWEVER...THE WEATHER PATTERN
WILL BE BRIEFLY ON THE QUIET AND COOL SIDE AS COLD HIGH PRESSURE
BUILDS INTO THE REGION TUESDAY NIGHT AND WEDNESDAY. RETURN FLOW
WILL THEN QUICKLY BEGIN TO RE-ESTABLISH ITSELF LATE WEDNESDAY NIGHT
AS THE REMNANTS OF THE COLD FRONT WHICH WILL HAVE MOVED THROUGH ON
TUESDAY...SHIFT BACK NORTHWARD INTO THE AREA FOR THE END OF THE WORK
WEEK. THE BOUNDARY IS THEN EXPECTED TO STALL OUT ACROSS THE
PENINSULA THROUGH THE UPCOMING WEEKEND. AS A RESULT...WILL NEED TO
KEEP RAIN CHANCES IN THE FORECAST THURSDAY THROUGH SUNDAY...WITH THE
ONLY PERIODS EXPECTED TO REMAIN RAIN FREE AT THIS TIME BEING TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. TEMPERATURES WILL START OUT WELL
BELOW NORMAL WEDNESDAY AND THURSDAY BEFORE MODERATING TO NEAR NORMAL
LEVELS FRIDAY THROUGH NEXT SUNDAY.
&&
.AVIATION...
THROUGH 24/18Z: SCT TO BKN CLOUDS...OCNL MVFR CIGS...THROUGH THE
EVENING. AN APPROACHING FRONTAL BOUNDARY WILL BRING PREVAILING MVFR
AFTER MIDNIGHT...MAINLY IN LOW CIGS BUT SOME BR ESPECIALLY AT LAL
AND PGD. AFTER SUNRISE...CLOUDS LIFT SOME WITH SCT-BKN LOW CLOUDS
UNDER AN OVC MID DECK WITH VCNTY SHRA. W-SW WINDS ROBUST AT TIMES
TURN TO W-NW THEN NORTH AND DIMINISH OVERNIGHT, WINDS BECOME NE BY
THE END OF THE PERIOD.
&&
.MARINE...
C-MAN AND OFFSHORE BUOY REPORTS SHOW SOUTHWEST TO WEST WINDS
AROUND 10 KNOTS WITH SEAS AROUND 1 TO 2 FEET OVER THE COASTAL
WATERS THIS AFTERNOON. AS A COLD FRONT NOW TO THE NORTH OF THE
WATERS SINKS SOUTH TONIGHT WINDS WILL BECOME NORTHWEST TO NORTH
AFTER MIDNIGHT WITH SPEEDS INCREASING TO EXERCISE CAUTION LEVELS
FROM ENGLEWOOD NORTH TO THE SUWANNEE RIVER OUT 60NM WHERE EXERCISE
CAUTION HEADLINES WILL BE DEPICTED. AS THE FRONT SETTLES IN AND
STALLS OUT ACROSS THE SOUTHERN PENINSULA ON MONDAY WINDS WILL
VEER TO THE NORTH AND NORTHEAST AND REMAIN IN THE 13 TO 18 KNOT
RANGE. THE SEAS WILL RESPOND TO THESE INCREASING WINDS...BUILDING
UP TO 3 TO 4 FEET IN THE OFFSHORE WATERS. SOME SEA AND COASTAL
FOG MAY DEVELOP AHEAD OF THE FRONT LATER TONIGHT...WITH THE BEST
CHANCES OF SEEING REDUCED VISIBILITIES OCCURRING FROM ENGLEWOOD
NORTH.
WEAK LOW PRESSURE WILL MOVE ACROSS THE WATERS MONDAY NIGHT
INTENSIFYING AS IT MOVES OFFSHORE THE SOUTHEAST U.S. AND MID
ATLANTIC COASTS EARLY ON TUESDAY. AS THIS OCCURS A STRONGER COLD
FRONT WILL SWEEP SOUTH THROUGH THE WATERS ON TUESDAY WITH WINDS
AND SEAS LIKELY INCREASING INTO THE SMALL CRAFT RANGE THROUGH
EARLY WEDNESDAY. SURFACE HIGH PRESSURE NORTH OF THE WATERS ON
WEDNESDAY WILL SHIFT EAST OFF THE MID ATLANTIC COAST THURSDAY AND
FURTHER EAST INTO THE OPEN ATLANTIC ON FRIDAY. A RATHER TIGHT
GRADIENT ASSOCIATED WITH THIS HIGH WILL KEEP WINDS AND SEAS
ELEVATED THROUGH THE PERIOD AS THE FLOW VEERS INTO THE EAST ON
THURSDAY...THE SOUTHEAST ON FRIDAY.
&&
.FIRE WEATHER...
NO SIGNIFICANT FIRE WEATHER CONCERNS ARE EXPECTED THROUGH THE EARLY
PORTION OF THE WEEK. RELATIVE HUMIDITY VALUES WILL REMAIN WELL
ABOVE CRITICAL LEVELS WITH WIDESPREAD SHOWERS DEVELOPING BY LATER
MONDAY INTO MONDAY NIGHT. A COLD FRONT WILL EXIT THE AREA EARLY
TUESDAY WITH A SOMEWHAT DRIER AND COOLER AIRMASS ARRIVING FOR THE
MIDDLE PORTION OF THE WEEK.
FOG POTENTIAL...AREAS OF FOG ARE EXPECTED OVERNIGHT...MAINLY NEAR
THE COAST...AND DOWN INTO THE SOUTH-CENTRAL INTERIOR ZONES. SOME
AREAS OF DENSE FOG ARE POSSIBLE...ESPECIALLY LATE AT NIGHT AND
INTO THE FIRST FEW DAYLIGHT HOURS OF MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 64 75 63 73 / 20 70 80 50
FMY 68 84 67 77 / 10 50 80 60
GIF 65 78 62 74 / 20 70 80 50
SRQ 67 77 64 73 / 20 70 80 50
BKV 61 75 58 73 / 20 70 80 40
SPG 67 76 65 73 / 20 70 80 50
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WEATHER...MROCZKA
LONG TERM...JELSEMA
AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
405 PM EDT SUN MAR 23 2014
.SYNOPSIS...
20Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUES TO SHOW A MAINLY ZONAL
FLOW PATTERN OVER THE NORTHERN GULF OF MEXICO AND FLORIDA PENINSULA.
A FEW VERY WEAK IMPULSES ARE EMBEDDED WITHIN THIS FLOW AND WILL BE
CROSSING ALONG THE NORTHERN GULF COAST THE NEXT 24 HOURS. WE ARE
JUST NOW BEGINNING TO SEE THE FIRST WAVES OF ENERGY DROPPING
SOUTHWARD FROM WESTERN CANADA INTO THE NORTHERN ROCKIES/UPPER
MIDWEST WHICH WILL TRIGGER A SIGNIFICANT AMPLIFICATION TO THE UPPER
LEVEL PATTERN OVER THE EASTERN HALF OF THE NATION DURING THE FIRST
HALF OF THE WEEK. THIS AMPLIFICATION WILL EVENTUALLY BRING A STRONG
COLD FRONT THROUGH THE FORECAST AREA ON TUESDAY...BUT UNTIL THAT
TIME...CHANCES FOR SHOWERS WILL BE INCREASING WITH TIME AND
RESULTING IN WHAT APPEARS TO BE A DAMP PERIOD LATER MONDAY INTO
MONDAY NIGHT.
AT THE SURFACE...HIGH PRESSURE CONTINUES TO DROP SOUTH AND WEAKEN IN
RESPONSE TO THE APPROACH OF A WEAK COLD FRONT FROM THE NORTH. THIS
FRONT IS CURRENTLY UP OVER SOUTHERN GA/AL...AND WILL SLOWLY SETTLE
SOUTH TO A POSITION OVER CENTRAL/SOUTHERN FLORIDA BY MONDAY MORNING.
REGIONAL RADARS ARE CURRENTLY SHOWING A FEW SCT INSTABILITY SHOWERS
DEVELOPING ALONG THE SEA-BREEZE AND MOVING INLAND THIS AFTERNOON.
THIS ACTIVITY WILL CONTINUE TO MOVE INLAND AND DISSIPATE AS WE HEAD
INTO THE EVENING HOURS. A FEW MORE SCATTERED SHOWERS WILL BE HEADED
SOUTH ASSOCIATED WITH THE SURFACE FOCUS ALONG/AHEAD OF THE FRONT BY
LATER THIS EVENING.
&&
.SHORT TERM (TONIGHT THROUGH TUESDAY)...
TONIGHT...AS MENTIONED ABOVE...A WEAK SURFACE BOUNDARY WILL SLIP
SOUTH INTO THE PENINSULA THROUGH THE OVERNIGHT HOURS. OVERALL NOT
MUCH IN THE WAY OF LARGE SCALE SYNOPTIC FORCING FOR ASCENT IN THE
VICINITY OVERNIGHT...SO ONLY EXPECTING A FEW NUISANCE TYPE SHOWERS
ASSOCIATED WITH THIS FEATURE. RAIN CHANCES FOR THE TAMPA BAY AREA
NORTHWARD WILL GENERALLY BE IN THE THE 20-30% RANGE WITH ANY LIKELY
BEING LIGHT IN NATURE.
MONDAY/MONDAY NIGHT...WEAK BOUNDARY WILL STALL OUT OVER THE SOUTHERN
HALF OF THE AREAS ON MONDAY AND EXTEND OUT INTO THE EASTERN GULF OF
MEXICO. LIKELY WILL SEE QUITE A BIT OF CLOUDS ALREADY AROUND BY
MORNING...WITH A FEW SCT SHOWERS CONTINUING. AS THE DAY
PROGRESSES...GLOBAL MODELS ALL SHOW AN INCREASINGLY PROMINENT
ISENTROPIC UPGLIDE REGIME ALONG THE 290-300K SURFACES BECOMING
ESTABLISHED ALONG AND TO THE NORTH OF THE BOUNDARY. AT THE SAME
TIME...UPPER LEVEL DIVERGENCE ASSOCIATED WITH A JET CORE ALONG THE
NORTHERN GULF COAST WILL BE INCREASING TO AID THIS LOWER LEVEL LIFT.
THE OVERALL RESULT WILL BE GREATER COVERAGE OF SHOWERS AS THE
DAY PROGRESSES...WITH A RATHER WET SCENARIO LIKELY BY MONDAY EVENING
INTO MONDAY NIGHT. AS IT APPEARS NOW...THE BEST CHANCES FOR BREAKS
OF SUN DURING THE DAY ON MONDAY WILL BE OVER THE SOUTHERN ZONES
(CHARLOTTE/LEE COUNTIES) TO THE SOUTH OF THE FRONT. HOWEVER...ENOUGH
HEATING WILL ALLOW FOR SEA-BREEZE DEVELOPMENT. WITH SOME SYNOPTIC
FORCING IN PLACE...IT LIKELY WILL NOT TAKE MUCH SURFACE FOCUS TO GET
SOME SEA-BREEZE SHOWERS OR STORMS GOING FOR THE AFTERNOON.
THEREFORE...MOST AREAS TOMORROW SHOULD SEE SOME RAIN...WHETHER IT BE
FROM A STRATIFORM PROCESS NORTH...OR A CONVECTIVE PROCESS SOUTH.
TUESDAY...
LOTS OF SHOWERS LIKELY TO STILL BE AROUND TUESDAY MORNING...
ESPECIALLY FROM TAMPA BAY SOUTHWARD...AS THE UPPER LEVEL PATTERN
QUICKLY BEGINS TO AMPLIFY INTO THE EASTERN CONUS. THIS AMPLIFICATION
IS CURRENTLY PROGGED TO RESULT IN RAPID CYCLOGENESIS OFF THE
CAROLINA COAST THE SECOND HALF OF TUESDAY...AND THIS PROCESS ALONG
WITH THE PASSING UPPER TROUGH AXIS WILL HELP PROPEL A STRENGTHENING
COLD FRONT SOUTH OF OUR AREA...AND BEGIN TO DRY US OUT FROM THE
NORTH. BY LATE IN THE DAY ON TUESDAY...ALL SHOWERS SHOULD HAVE
ENDED...EVEN FOR THE FAR SOUTHERN ZONES...WITH A RATHER COOL AIRMASS
FOR LATE MARCH ARRIVING BY TUESDAY NIGHT.
&&
.LONG TERM (TUESDAY NIGHT-SUNDAY)...
MEDIUM RANGE GUIDANCE IN IN FAIRLY GOOD AGREEMENT SHOWING AN
UNSETTLED WEATHER PATTERN ACROSS THE REGION THROUGH THE LONG TERM
PERIOD. AT THE BEGINNING OF THE PERIOD HOWEVER...THE WEATHER PATTERN
WILL BE BRIEFLY ON THE QUIET AND COOL SIDE AS COLD HIGH PRESSURE
BUILDS INTO THE REGION TUESDAY NIGHT AND WEDNESDAY. RETURN FLOW
WILL THEN QUICKLY BEGIN TO RE-ESTABLISH ITSELF LATE WEDNESDAY NIGHT
AS THE REMNANTS OF THE COLD FRONT WHICH WILL HAVE MOVED THROUGH ON
TUESDAY...SHIFT BACK NORTHWARD INTO THE AREA FOR THE END OF THE WORK
WEEK. THE BOUNDARY IS THEN EXPECTED TO STALL OUT ACROSS THE
PENINSULA THROUGH THE UPCOMING WEEKEND. AS A RESULT...WILL NEED TO
KEEP RAIN CHANCES IN THE FORECAST THURSDAY THROUGH SUNDAY...WITH THE
ONLY PERIODS EXPECTED TO REMAIN RAIN FREE AT THIS TIME BEING TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. TEMPERATURES WILL START OUT WELL
BELOW NORMAL WEDNESDAY AND THURSDAY BEFORE MODERATING TO NEAR NORMAL
LEVELS FRIDAY THROUGH NEXT SUNDAY.
&&
.AVIATION...
THROUGH 24/18Z: SCT TO BKN CLOUDS...OCNL MVFR CIGS...THROUGH THE
EVENING. AN APPROACHING FRONTAL BOUNDARY WILL BRING PREVAILING MVFR
AFTER MIDNIGHT...MAINLY IN LOW CIGS BUT SOME BR ESPECIALLY AT LAL
AND PGD. AFTER SUNRISE...CLOUDS LIFT SOME WITH SCT-BKN LOW CLOUDS
UNDER AN OVC MID DECK WITH VCNTY SHRA. W-SW WINDS ROBUST AT TIMES
TURN TO W-NW THEN NORTH AND DIMINISH OVERNIGHT, WINDS BECOME NE BY
THE END OF THE PERIOD.
&&
.MARINE...
&&
.FIRE WEATHER...
NO SIGNIFICANT FIRE WEATHER CONCERNS ARE EXPECTED THROUGH THE EARLY
PORTION OF THE WEEK. RELATIVE HUMIDITY VALUES WILL REMAIN WELL
ABOVE CRITICAL LEVELS WITH WIDESPREAD SHOWERS DEVELOPING BY LATER
MONDAY INTO MONDAY NIGHT. A COLD FRONT WILL EXIT THE AREA EARLY
TUESDAY WITH A SOMEWHAT DRIER AND COOLER AIRMASS ARRIVING FOR THE
MIDDLE PORTION OF THE WEEK.
FOG POTENTIAL...AREAS OF FOG ARE EXPECTED OVERNIGHT...MAINLY NEAR
THE COAST...AND DOWN INTO THE SOUTH-CENTRAL INTERIOR ZONES. SOME
AREAS OF DENSE FOG ARE POSSIBLE...ESPECIALLY LATE AT NIGHT AND
INTO THE FIRST FEW DAYLIGHT HOURS OF MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 64 75 63 73 / 20 70 80 50
FMY 68 84 67 77 / 10 50 80 60
GIF 65 78 62 74 / 20 70 80 50
SRQ 67 77 64 73 / 20 70 80 50
BKV 61 75 58 73 / 20 70 80 40
SPG 67 76 65 73 / 20 70 80 50
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM...JELSEMA
AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS MIAMI FL
216 PM EDT SUN MAR 23 2014
.UPDATE...
MADE A QUICK CHANGE FOR THE AFTERNOON AND ADDED SLIGHT CHANCE OF A
SHOWER ALONG THE SOUTHEAST COAST. TEMPERATURES HAVE SOARED CLOSE
TO 90 AND A SEA BREEZE HAS DEVELOPED SLOWLY PUSHING INLAND. THE
LATEST HRRR IS NOW SHOWING A COUPLE OF LATE AFTERNOON SHOWERS
DEVELOPING ALONG THE BREEZE.
&&
.PREV DISCUSSION... /ISSUED 141 PM EDT SUN MAR 23 2014/
SHORT TERM (TONIGHT-TUESDAY NIGHT)...
SOUTH FLORIDA REMAINS UNDER THE INFLUENCE OF ZONAL FLOW ALOFT WITH
WEAK HIGH PRESSURE AT THE SURFACE. THIS TREND WILL CONTINUE
THROUGH EARLY MONDAY. A LARGE SCALE MID LEVEL TROUGH WILL DEEPEN
ACROSS EASTERN CANADA TONIGHT AND THEN INTO THE NEW ENGLAND STATES
MONDAY NIGHT AND TUESDAY. A COLD FRONT ASSOCIATED WITH THE
CANADIAN TROUGH WILL MOVE INTO NORTH FLORIDA THIS EVENING AND
SLOWLY MOVE DOWN THE PENINSULA ON MONDAY ARRIVING IN SOUTH FLORIDA
DURING THE AFTERNOON WHERE IT WILL THEN STALL. A SOUTHERN STREAM
PERTURBATION EMBEDDED IN THE ZONAL FLOW ACROSS THE NORTHERN GULF
OF MEXICO WILL AID IN MOVING THE FRONT BACK NORTH BY MONDAY
EVENING AND A SURFACE WAVE WILL DEVELOP ALONG THE BOUNDARY IN
RESPONSE TO SOUTHERN STREAM TROUGH. ALL OF THIS WILL COMBINE TO
PROVIDE DECENT VERTICAL ASCENT ACROSS THE FLORIDA PENINSULA MONDAY
NIGHT THROUGH MOST OF THE DAY ON TUESDAY FOR A CLOUDY WEATHER
PATTERN FOR SOUTH FLORIDA WITH PERIODS OF RAIN. FORECAST SOUNDINGS
SHOW PWAT INCREASING IN THE RANGE OF 1.6-1.8 INCHES IN THE TIME
PERIOD MONDAY NIGHT THROUGH TUESDAY. THIS PLACES THE PWAT AT WELL
ABOVE NORMAL AND ONLY EXCESSIVE IF THE HIGHER RANGE CAN BE
ACHIEVED. SO, RAINFALL AMOUNTS ARE NOT EXPECTED TO BE EXCESSIVE
BUT OVERALL COVERAGE WILL BE ON THE ORDER OF ONE TO TWO INCHES
WITH ISOLATED HIGHER AMOUNTS ALWAYS POSSIBLE, ESPECIALLY IF
TRAINING OF ECHOES BEGINS TO ENFOLD. THE NEW ENGLAND TROUGH WILL
CONTINUE TO DEEPEN TO THE SOUTHEAST ON MONDAY NIGHT AND TUESDAY
WHICH IN TURN WILL CAUSE THE SURFACE WAVE TO LIFT TO THE NORTHEAST
ON TUESDAY AND THE COLD FRONT WILL FINALLY PUSH THROUGH SOUTH
FLORIDA BY TUESDAY AFTERNOON AND OFF THE SOUTHEAST COAST TUESDAY
EVENING. THE SKY WILL THEN CLEAR TUESDAY NIGHT WITH COOLER
TEMPERATURES AS COOLER AND DRIER AIR FILTER DOWN THE PENINSULA
BEHIND THE FRONT.
LONG TERM (WEDNESDAY-SUNDAY)...
THE FIRST PART OF THE EXTENDED WILL BEGIN DRY AND PLEASANT WITH
TEMPERATURES ON WEDNESDAY AFTERNOON REMAINING IN THE 70S. A ZONAL
FLOW PATTERN WILL RETURN BY THURSDAY CONTINUING INTO NEXT WEEKEND.
HOWEVER, ANOTHER EMBEDDED MID LEVEL TROUGH WILL MOVE ACROSS THE
GULF OF MEXICO AND OVER SOUTH FLORIDA THURSDAY AND FRIDAY FOR
ANOTHER INCREASE IN SHOWER ACTIVITY POSSIBLY LINGERING INTO
SATURDAY BEFORE DRYING OUT AGAIN ON SUNDAY.
MARINE...
WIND AND SEAS WILL REMAIN RATHER TRANQUIL THROUGH MONDAY AS HIGH
PRESSURE DOMINATES. A COLD FRONT WILL MOVE INTO THE SOUTH FLORIDA
WATERS LATE MONDAY AND THEN RETREAT BACK TO THE NORTH MONDAY
NIGHT. A SECONDARY COLD FRONT WILL MOVE THROUGH THE LOCAL WATERS
LATE TUESDAY WITH HIGH PRESSURE BUILDING BEHIND THE FRONT. LOCAL
WIND WILL BE LIGHT AND MAINLY WESTERLY TONIGHT RAPIDLY BECOMING
LIGHT NORTHEAST ON MONDAY AS THE FRONT APPROACHES. EXTENSIVE AREAS
OF RAIN WILL DEVELOP LATE MONDAY THROUGH TUESDAY AND THEN CLEAR
OUT TUESDAY EVENING AS THE FRONT PUSHES OFF THE SOUTHEAST COAST.
WIND WILL SHIFT TO THE NORTHWEST BEHIND THE FRONT TUESDAY NIGHT
AND WEDNESDAY POSSIBLY INCREASING TO AROUND 20 KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 70 80 69 80 / 10 40 70 50
FORT LAUDERDALE 71 81 71 80 / 10 40 60 60
MIAMI 71 83 71 80 / 10 40 50 60
NAPLES 70 79 69 76 / 10 40 70 70
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...23/SK
LONG TERM....30/KB
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS JACKSONVILLE FL
625 AM EDT SUN MAR 23 2014
.SHORT TERM...TODAY AND TONIGHT...AREAS OF DENSE FOG OVER COASTAL NE
FL HAVE SHIFTED NE INTO SE GA AND THE ADJACENT COASTAL WATERS.
THIS MOVEMENT SHOULD CONTINUE AS MODELS AND OBS SHOW SW WINDS
INCREASING EARLY THIS MORNING. WILL MONITOR BUT DO NOT PLAN ON AN
ADVISORY AS CONDITIONS SHOULD IMPROVE FROM THE SW THE NEXT COUPLE
OF HOURS. HRRR AND NARRE MODELS SHOW ANOTHER AREA OF DENSE FOG
FORMING AFTER 08Z FROM THE EASTERN GULF INTO THE SUWANNEE VALLEY.
AN EMBEDDED IMPULSE IN ZONAL FLOW ALOFT WILL BRING A CHANCE OF
SHOWERS THIS AFTERNOON WITH ISOLATED THUNDER POSSIBLE DUE TO WEAK
CAPE/INSTABILITY. COLD FRONT TO THE NORTH WILL SINK SOUTH THROUGH
THE AREA TONIGHT AS UPPER IMPULSE MOVES EAST INTO THE ATLANTIC. N
TO NE WINDS WILL SPREAD ACROSS THE AREA FROM THE NORTH AFTER
MIDNIGHT REACHING SOUTHERN ZONES BY 12Z MONDAY. HIGH TEMPERATURES
TODAY WILL AGAIN REACH THE UPPER 70S/LOWER 80S WITH MINIMUM
TEMPERATURES TONIGHT COOLING INTO THE UPPER 40S OVER SE GA BEHIND
FRONT.
FOR MONDAY...THE COLD FRONT WILL ENTER CENTRAL/SOUTHERN
FLORIDA...WITH MUCH COOLER AIR WORKING IN. EXPECT HIGH TEMPERATURES
IN THE LOWER TO MID 60S FROM I-10 NORTHWARD...WITH 65-70 FURTHER
SOUTH. MODELS COMING INTO BETTER AGREEMENT WITH WAVES RIDING NORTH
OF THE SURFACE BOUNDARY...WITH NE FL HAVING THE GREATEST SHOT AT
ORGANIZED PRECIP MONDAY AFTN. WILL USE MID/HIGH END CHANCE POPS FOR
MOST OF NE FL...WITH LESSER CHANCES ACROSS SE GA...WITH FAR INTERIOR
SE GA MAINLY DRY. BREEZY TO WINDY CONDITIONS WILL DEVELOP MONDAY WITH
LAKE WIND ADVISORIES POSSIBLE ALONG THE COAST. WITH INSTABILITY
ESSENTIALLY NON-EXISTENT THROUGH MOST OF THE DAY WILL LEAVE TSTMS
OUT OF THE FCST.
MONDAY NIGHT/TUESDAY...A STRONGER WAVE OF LOW PRESSURE WILL ROTATE
AROUND THE PARENT UPPER LOW TO THE NORTH ACROSS THE REGION MONDAY
NIGHT...EXITING TUESDAY MORNING. WITH SOME DEEPER MOISTURE TAP
THINK PRECIP COVERAGE WILL INCREASE SUBSTANTIALLY...ONCE AGAIN
WITH THE GREATEST COVERAGE ACROSS NORTH-CENTRAL FL. WILL USE
CATEGORICAL POPS THERE...WITH LIKELY POPS FOR NE FL/SE GA MONDAY
NIGHT. A RAPID PRECIP DECREASE WILL OCCUR TUESDAY MORNING AS
THE LOW EXITS TO THE EAST...WITH MOST AREAS DRY BY MIDDAY INTO
THE EARLY AFTN. WITH THE STRONGER LOW MONDAY NIGHT AND GREATER
MID LEVEL DYNAMICS...A FEW TSTMS WILL BE POSSIBLE...THUS WILL
USE SLIGHT CHANCE OF TSTMS FOR ALL AREAS MONDAY NIGHT WITH THE
THUNDER THREAT ENDING TUESDAY MORNING. EXPECT AREAL AVERAGE
RAINFALL TOTALS TO RANGE FROM AROUND A HALF INCH FOR SE GA TO
AROUND 1 INCH FOR NE FL. BREEZY TO WINDY CONDITIONS WILL PREVAIL
ONCE AGAIN TUESDAY. LOWS MONDAY NIGHT WILL BE SLIGHTLY ABOVE
NORMAL WITH THICK CLOUD COVER...WITH HIGHS TUESDAY SEASONABLY COOL
BUT A BIT MILDER THAN MONDAY.
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
TUESDAY NIGHT AND WEDNESDAY WILL BE MOSTLY CLEAR BUT QUITE COOL AS
HIGH PRESSURE BUILDS IN FROM THE NORTH. RESIDUAL BREEZY CONDITIONS
WILL ADD TO THE CHILL...BUT WILL PREVENT ANY FROST TUESDAY NIGHT
AS LOWS WILL FALL INTO THE MID/UPPER 30S INLAND. THE HIGH WILL
DEPART TO THE EAST THURSDAY...WITH THE NEXT SYSTEM PROGGED TO
AFFECT THE AREA FRIDAY INTO NEXT WEEKEND. WITH MEDIUM RANGE MODELS
FALLING INTO BETTER AGREEMENT...WILL USE LOW POPS THURSDAY NIGHT
AND FRIDAY...WITH MID/HIGH END CHANCE POPS FRIDAY NIGHT/SATURDAY.
SEASONABLY COOL TEMPERATURES THURSDAY WILL WARM TO SLIGHTLY ABOVE
NORMAL FOR FRIDAY/SATURDAY.
.AVIATION...
PATCHY BR WILL PREVAIL AT VQQ/JAX/GNV TIL 13-14Z...OTHERWISE VFR
WILL PREVAIL FOR THE NEXT 24 HOURS. CIGS WILL DEVELOP AND LOWER
LATE THIS MORNING AS A COLD FRONT APPROACHES. WILL USE VCSH FOR
ALL PORTS THIS AFTN INTO EVENING FOR SCATTERED SHOWERS. SOME LOW
CLOUDS WILL BE POSSIBLE OVERNIGHT TNGT...ESPECIALLY AT GNV. WITH
SOME UNCERTAINTY...WILL USE SCT010 FOR GNV FOR NOW.
&&
.MARINE...AREA OF DENSE FOG OVER THE GA WATERS EARLY THIS MORNING.
WILL MONITOR FOR AN DENSE FOG ADVISORY BUT DENSE FOG MAY BE SHORT
LIVED AS INCREASING SW WINDS SHOULD BRING IMPROVING CONDITIONS.
COLD FRONT WILL MOVE SOUTH ACROSS THE WATERS TONIGHT BRINGING A
SURGE IN NE WINDS. WILL ISSUE SMALL CRAFT ADVISORY STARTING AT
MIDNIGHT TONIGHT. SCA CONDITIONS WILL CONTINUE MONDAY IN THE WAKE OF
THE FRONT...WITH CONDITIONS BRIEFLY IMPROVING MONDAY NIGHT AS LOW
PRESSURE MOVES ACROSS THE WATERS. AS THE LOW EJECTS NE AND RAPIDLY
INTENSIFIES TUESDAY...WINDS WILL INCREASE ONCE AGAIN...WITH GALES
QUITE LIKELY OFFSHORE TUESDAY AFTN/NIGHT. AS THE LOW EXITS INTO NEW
ENGLAND WEDNESDAY...EXPECT CONDITIONS TO IMPROVE SOMEWHAT FOR THE
LATTER HALF OF THE WEEK...HOWEVER CAUTION CONDITIONS WILL STILL BE
POSSIBLE.
RIP CURRENTS: LOW RISK TODAY. MODERATE RISK ON MONDAY AS ONSHORE
WINDS INCREASE WITH BUILDING SEAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 79 49 62 47 / 40 40 10 60
SSI 73 53 59 53 / 30 30 30 70
JAX 80 54 63 53 / 30 40 40 70
SGJ 78 59 64 57 / 30 40 50 70
GNV 80 57 67 53 / 40 40 50 80
OCF 81 57 71 56 / 30 40 60 80
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 4 AM EDT TUESDAY
FOR ALTAMAHA SOUND GA TO FERNANDINA BEACH FL 20 NM TO 60 NM
OFFSHORE-FERNANDINA BEACH TO ST AUGUSTINE FL 20 NM TO 60 NM
OFFSHORE-ST AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM
OFFSHORE.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 10 PM EDT MONDAY
FOR ALTAMAHA SOUND GA TO FERNANDINA BEACH FL OUT 20 NM-
FERNANDINA BEACH TO ST AUGUSTINE FL OUT 20 NM-ST AUGUSTINE
TO FLAGLER BEACH FL OUT 20 NM.
&&
$$
ZIBURA/ALLEN/
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
307 AM EDT SUN MAR 23 2014
.SHORT TERM...TODAY AND TONIGHT...AREAS OF DENSE FOG OVER COASTAL NE
FL HAVE SHIFTED NE INTO SE GA AND THE ADJACENT COASTAL WATERS.
THIS MOVEMENT SHOULD CONTINUE AS MODELS AND OBS SHOW SW WINDS
INCREASING EARLY THIS MORNING. WILL MONITOR BUT DO NOT PLAN ON AN
ADVISORY AS CONDITIONS SHOULD IMPROVE FROM THE SW THE NEXT COUPLE
OF HOURS. HRRR AND NARRE MODELS SHOW ANOTHER AREA OF DENSE FOG
FORMING AFTER 08Z FROM THE EASTERN GULF INTO THE SUWANNEE VALLEY.
AN EMBEDDED IMPULSE IN ZONAL FLOW ALOFT WILL BRING A CHANCE OF
SHOWERS THIS AFTERNOON WITH ISOLATED THUNDER POSSIBLE DUE TO WEAK
CAPE/INSTABILITY. COLD FRONT TO THE NORTH WILL SINK SOUTH THROUGH
THE AREA TONIGHT AS UPPER IMPULSE MOVES EAST INTO THE ATLANTIC. N
TO NE WINDS WILL SPREAD ACROSS THE AREA FROM THE NORTH AFTER
MIDNIGHT REACHING SOUTHERN ZONES BY 12Z MONDAY. HIGH TEMPERATURES
TODAY WILL AGAIN REACH THE UPPER 70S/LOWER 80S WITH MINIMUM
TEMPERATURES TONIGHT COOLING INTO THE UPPER 40S OVER SE GA BEHIND
FRONT.
FOR MONDAY...THE COLD FRONT WILL ENTER CENTRAL/SOUTHERN
FLORIDA...WITH MUCH COOLER AIR WORKING IN. EXPECT HIGH TEMPERATURES
IN THE LOWER TO MID 60S FROM I-10 NORTHWARD...WITH 65-70 FURTHER
SOUTH. MODELS COMING INTO BETTER AGREEMENT WITH WAVES RIDING NORTH
OF THE SURFACE BOUNDARY...WITH NE FL HAVING THE GREATEST SHOT AT
ORGANIZED PRECIP MONDAY AFTN. WILL USE MID/HIGH END CHANCE POPS FOR
MOST OF NE FL...WITH LESSER CHANCES ACROSS SE GA...WITH FAR INTERIOR
SE GA MAINLY DRY. BREEZY TO WINDY CONDITIONS WILL DEVELOP MONDAY WITH
LAKE WIND ADVISORIES POSSIBLE ALONG THE COAST. WITH INSTABILITY
ESSENTIALLY NON-EXISTENT THROUGH MOST OF THE DAY WILL LEAVE TSTMS
OUT OF THE FCST.
MONDAY NIGHT/TUESDAY...A STRONGER WAVE OF LOW PRESSURE WILL ROTATE
AROUND THE PARENT UPPER LOW TO THE NORTH ACROSS THE REGION MONDAY
NIGHT...EXITING TUESDAY MORNING. WITH SOME DEEPER MOISTURE TAP
THINK PRECIP COVERAGE WILL INCREASE SUBSTANTIALLY...ONCE AGAIN
WITH THE GREATEST COVERAGE ACROSS NORTH-CENTRAL FL. WILL USE
CATEGORICAL POPS THERE...WITH LIKELY POPS FOR NE FL/SE GA MONDAY
NIGHT. A RAPID PRECIP DECREASE WILL OCCUR TUESDAY MORNING AS
THE LOW EXITS TO THE EAST...WITH MOST AREAS DRY BY MIDDAY INTO
THE EARLY AFTN. WITH THE STRONGER LOW MONDAY NIGHT AND GREATER
MID LEVEL DYNAMICS...A FEW TSTMS WILL BE POSSIBLE...THUS WILL
USE SLIGHT CHANCE OF TSTMS FOR ALL AREAS MONDAY NIGHT WITH THE
THUNDER THREAT ENDING TUESDAY MORNING. EXPECT AREAL AVERAGE
RAINFALL TOTALS TO RANGE FROM AROUND A HALF INCH FOR SE GA TO
AROUND 1 INCH FOR NE FL. BREEZY TO WINDY CONDITIONS WILL PREVAIL
ONCE AGAIN TUESDAY. LOWS MONDAY NIGHT WILL BE SLIGHTLY ABOVE
NORMAL WITH THICK CLOUD COVER...WITH HIGHS TUESDAY SEASONABLY COOL
BUT A BIT MILDER THAN MONDAY.
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
TUESDAY NIGHT AND WEDNESDAY WILL BE MOSTLY CLEAR BUT QUITE COOL AS
HIGH PRESSURE BUILDS IN FROM THE NORTH. RESIDUAL BREEZY CONDITIONS
WILL ADD TO THE CHILL...BUT WILL PREVENT ANY FROST TUESDAY NIGHT
AS LOWS WILL FALL INTO THE MID/UPPER 30S INLAND. THE HIGH WILL
DEPART TO THE EAST THURSDAY...WITH THE NEXT SYSTEM PROGGED TO
AFFECT THE AREA FRIDAY INTO NEXT WEEKEND. WITH MEDIUM RANGE MODELS
FALLING INTO BETTER AGREEMENT...WILL USE LOW POPS THURSDAY NIGHT
AND FRIDAY...WITH MID/HIGH END CHANCE POPS FRIDAY NIGHT/SATURDAY.
SEASONABLY COOL TEMPERATURES THURSDAY WILL WARM TO SLIGHTLY ABOVE
NORMAL FOR FRIDAY/SATURDAY.
.AVIATION...
LOW CLOUDS/FOG HAVE DISSIPATED ACROSS THE NE FL TAFS AS WESTERLY
FLOW HAS DEVELOPED. THINK ANY LOW CLOUDS FROM THE GULF WILL REMAIN
TO THE SW...THUS WILL USE VFR...WITH INCREASING MID DECK CLOUDS THIS
AFTN AS A FRONTAL BOUNDARY APPROACHES. FOR SSI...VLIFR CONDITIONS
WILL IMPROVE IN THE NEXT 2-3 HOURS TO MVFR...THEN VFR SHORTLY AFTER
THAT. WILL USE VCSH FOR SHOWERS LATER TODAY FOR ALL PORTS...ENDING
BY 02-04Z MONDAY.
&&
.MARINE...AREA OF DENSE FOG OVER THE GA WATERS EARLY THIS MORNING.
WILL MONITOR FOR AN DENSE FOG ADVISORY BUT DENSE FOG MAY BE SHORT
LIVED AS INCREASING SW WINDS SHOULD BRING IMPROVING CONDITIONS.
COLD FRONT WILL MOVE SOUTH ACROSS THE WATERS TONIGHT BRINGING A
SURGE IN NE WINDS. WILL ISSUE SMALL CRAFT ADVISORY STARTING AT
MIDNIGHT TONIGHT. SCA CONDITIONS WILL CONTINUE MONDAY IN THE WAKE OF
THE FRONT...WITH CONDITIONS BRIEFLY IMPROVING MONDAY NIGHT AS LOW
PRESSURE MOVES ACROSS THE WATERS. AS THE LOW EJECTS NE AND RAPIDLY
INTENSIFIES TUESDAY...WINDS WILL INCREASE ONCE AGAIN...WITH GALES
QUITE LIKELY OFFSHORE TUESDAY AFTN/NIGHT. AS THE LOW EXITS INTO NEW
ENGLAND WEDNESDAY...EXPECT CONDITIONS TO IMPROVE SOMEWHAT FOR THE
LATTER HALF OF THE WEEK...HOWEVER CAUTION CONDITIONS WILL STILL BE
POSSIBLE.
RIP CURRENTS: LOW RISK TODAY. MODERATE RISK ON MONDAY AS ONSHORE
WINDS INCREASE WITH BUILDING SEAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 79 49 62 47 / 40 40 10 60
SSI 73 53 59 53 / 30 30 30 70
JAX 80 54 63 53 / 30 40 40 70
SGJ 78 59 64 57 / 30 40 50 70
GNV 80 57 67 53 / 40 40 50 80
OCF 81 57 71 56 / 30 40 60 80
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 4 AM EDT TUESDAY
FOR ALTAMAHA SOUND GA TO FERNANDINA BEACH FL 20 NM TO 60 NM
OFFSHORE-FERNANDINA BEACH TO ST AUGUSTINE FL 20 NM TO 60 NM
OFFSHORE-ST AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM
OFFSHORE.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 10 PM EDT MONDAY
FOR ALTAMAHA SOUND GA TO FERNANDINA BEACH FL OUT 20 NM-
FERNANDINA BEACH TO ST AUGUSTINE FL OUT 20 NM-ST AUGUSTINE
TO FLAGLER BEACH FL OUT 20 NM.
&&
$$
ZIBURA/ALLEN/
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1246 PM CDT SUN MAR 23 2014
.DISCUSSION...
656 AM CDT
HAD ADJUSTED POPS BASED ON TRENDS WITH LAKE EFFECT SNOW SHOWERS
TO INCLUDE CATEGORICAL THROUGH MID MORNING FOR ONGOING ACTIVITY
IN EASTERN COOK COUNTY AND LAKE/WESTERN PORTER IN INDIANA.
RECEIVED AN ESTIMATED REPORT OF 1.5 INCHES ACCUMULATED IN ROGERS
PARK...AND AREA WEB CAMS SHOW SNOW COVERED ROADWAYS AND SLOW
TRAVEL. SNOW SHOWERS SHOULD DRIFT SOUTHEAST WITH ACTIVITY FOCUSING
MORE INTO SOUTHEASTERN COOK AND NW INDIANA WITH TIME THOUGH THERE
IS SOME CONCERN PER RECENT HI-RES GUIDANCE THAT CONVERGENCE COULD
KEEP FOCUS A BIT FARTHER WEST FOR LONGER. EXPECTING UP TO AN
ADDITIONAL INCH OR SO OF SNOW BY 10 AM...WITH LOCAL AMOUNTS TO TWO
INCHES GIVEN PRESENCE OF FAIRLY HIGH REFLECTIVITY IN SNOW BAND.
LAKE EFFECT PARAMETERS SHOULD BECOME LESS FAVORABLE BEYOND MID
MORNING AS ACTIVITY SLIDES SOUTHEAST...BUT DAYSHIFT WILL NEED TO
CONTINUE TO MONITOR NEAR-TERM TRENDS. AN SPS HAS BEEN ISSUED
THROUGH 15Z TO COVER THE HAZARDS WITH THE ONGOING SNOW.
RC
//PREV DISCUSSION...
343 AM CDT
PRIMARY FORECAST CONCERNS ARE WITH LAKE EFFECT SNOW SHOWERS MAINLY
THIS MORNING OVER PORTIONS OF NW INDIANA AND POSSIBLY COOK COUNTY
IL...VERY COLD TEMPERATURES FOR LATE MARCH THROUGH MID WEEK AND
THE NEXT OPPORTUNITY FOR SNOW FROM MONDAY AFTERNOON INTO TUESDAY
MORNING.
IF YOU WOKE UP AND DIDNT KNOW WHAT TIME OF YEAR IT WAS...YOU WOULD
THINK BASED ON THE SURFACE AND UPPER PATTERN THIS MORNING THAT IT
WAS JANUARY AND NOT LATE MARCH. A DEEP COLD TROUGH IS NOTED ON W/V
CARVED OUT ACROSS THE EASTERN 2/3 OF NOAM. AT THE
SURFACE...EXPANSIVE ARCTIC HIGH PRESSURE AVERAGING 1035 MB STRETCHES
FROM THE CANADIAN PRAIRIES TO THE SOUTHERN PLAINS. 00Z RAOB PICKED
UP ON 850 MB TEMPS OF -15 AND -18C RESPECTIVELY AT GRB AND MPX
RESPECTIVELY AND IT IS THIS AIR MASS THAT IS FIRING UP LAKE EFFECT
SNOW SHOWERS AND WILL BRING US MID WINTER COLD TODAY AND TONIGHT.
REGARDING THE LAKE EFFECT: DESPITE RELYING MAINLY FROM MOISTURE FLUX
FROM COLD LAKE MAINLY IN EXTREMELY DRY AIR MASS...GOOD CONVERGENCE
AND IMPROVING THERMAL PROFILES FOR LAKE EFFECT HAVE GENERATED
ACTIVITY OVER SOUTHWESTERN PORTION OF LAKE MICHIGAN. LOCAL WRF MODEL
BASICALLY SOLE GUIDANCE THAT HAD BEEN BULLISH FOR LAKE EFFECT INTO
OUR AREA...BUT BASED ON RADAR TRENDS WILL NEED LIKELY POPS. GIVEN
CURRENT WIND CONVERGENCE SET-UP WOULD EXPECT ACITIVITY TO GENERALLY
FOCUS INTO LAKE AND PORTER COUNTIES BEFORE MOVING EAST AND
DISSIPATING. THERE COULD BE LIGHT ACCUMULATIONS ON THE ORDER OF AN
INCH OR TWO BEFORE THIS OCCURS. AM CONCERNED WITH MOST RECENT RUNS
OF RAP/HRRR GUIDANCE SUGGESTING MESO-LOW FORMATION AND
REORGANIZATION OF CONVERGENCE INTO COOK COUNTY. ALSO PURE
EXTRAPOLATION WOULD SUGGEST COOK COUNTY COULD GET CLIPPED...SO WILL
INCLUDE CHANCE POPS ON IMMEDIATE LAKEFRONT AND LET INCOMING SHIFT
MONITOR NEAR-TERM TRENDS.
TEMPERATURES TODAY AND TONIGHT: WHILE UPSTREAM OBS ARE ALREADY
EXCEPTIONAL FOR THE COLD AIR MASS PLUNGING SOUTH INTO OUR AREA
TODAY/850 MB OF -16C OR COLDER ARE IN COLDEST 1% THIS TIME OF
YEAR. NAM IS MOST BULLISH ON BRINGING CORE OF COLD TO THE
CWA...WHILE OTHER 00Z RUNS TOOK THE BRUNT OF IT JUST TO OUR EAST.
IF WE DO INDEED RECEIVE THE CORE OF THE COLD...HIGH TEMPERATURES
IN LOW 30S NORTH AND LOW-MID 30S SOUTH...WITH A FEW UPPER 20S
POSSIBLE FAR NORTH...MAY BE A HAIR TOO WARM. HOWEVER...BANKING ON
LATE MARCH SUN OUTSIDE LAKE EFFECT AREAS TO SUPPORT THE FORECAST
HIGHS. THE ARCTIC HIGH WILL BE OVERHEAD TONIGHT...BUT MID AND HIGH
CLOUDS ARE EXPECTED TO MOVE IN FROM WEST PRIOR TO DAWN. MAINTAIEND
PREVIOUS FORECAST OF MOSTLY MID TEENS OUTSIDE CHICAGO HEAT ISLAND.
IF SKIES REMAIN CLEARER LONGER...CANT RULE OUT AN ISOLATED SPOT
DOWN TO 10 OR JUST BELOW.
MONDAY THROUGH TUESDAY...WARM ADVECTION IN ADVANCE OF NEXT ARCTIC
FRONT SHOULD ENABLE TEMPERATURES TO REACH MID 30S DESPITE OVC SKIES.
GUIDANCE NOT IN BEST AGREEMENT WITH MULTIPLE SHORTWAVES IN NORTHWEST
FLOW. IT APPEARS LEAD WAVE COULD AFFECT MAINLY SOUTHWEST THIRD OF
CWA DURING AFTERNOON SO INCREASED POPS SOME. THERMAL PROFILES AND
WET BULBS SUPPORT SNOW AS PTYPE. INCREASED POPS TO LIKELY FOR THE
ENTIRE CWA MONDAY NIGHT...BUT CONFIDENCE IS NOT THE HIGHEST IN EXACT
EVOLUTION. LOOKS OVERALL TO BE A HIGH POP/LOW QPF SCENARIO...WITH
FORCING FROM MULTIPLE WAVES AND THERE POSSIBLY BEING A MINIMA IN
THIS SOMEWHERE OVER CWA. TOTAL SNOWFALL ACCUMULATIONS COULD END UP
IN 1-2 INCH RANGE...THOUGH COVERAGE MAY BE A BIT LESS BROAD THAN IN
CURRENT FORECAST. ARCTIC FRONT TRAILING FROM WEAK LOW OVER WISCONSIN
WILL SWEEP ACROSS THE AREA OVERNIGHT INTO TUESDAY MORNING...SETTING
THE STAGE FOR ANOTHER EXTREMELY COLD DAY...WITH HIGHS STRUGGLING TO
REACH FREEZING IN -16 TO -19 AT 850 MB AIRMASS.
TUESDAY NIGHT THROUGH FRIDAY...PATTERN WILL THEN QUICKLY SHIFT TO
RIDGING OVER CENTRAL CONUS AS IMPRESSIVELY DEEP SYSTEM OFF EAST
COAST AMPLIFIES THE PATTERN. HIGHS SHOULD RECOVER TO 35-40 ON
WEDNESDAY THANKS TO WAA AFTER MOST AREAS PLUMMET INTO TEENS BY
DAWN WEDS UNDER ARCTIC HIGH. FAIRLY DEEP TROUGH WILL THEN EJECT
ACROSS ROCKIES AND HIGH PLAINS BY EARLY THURSDAY...KEEPING
DOWNSTREAM RIDGE AMPLIFIED AND CAUSING STRONG SURFACE
CYCLOGENESIS. GUIDANCE IN GOOD AGREEMENT ON BRINGING THIS SYSTEM
WEST OF CWA...KEEPING US ON WARM SIDE AND PERIODS OF RAIN LIKELY
LATER THURSDAY INTO THURSDAY NIGHT. MOISTURE RETURN DOESNT APPEAR
ALL THAT IMPRESSIVE TO SUPPORT THUNDER CHANCES AT THIS
TIME...THOUGH STRONG ENOUGH SYSTEM COULD COMPENSATE WITH GOOD
DYNAMICS. DIFFERENCES THEN INCREASE ON HOW FAST SYSTEM MOVES TO
EAST LATER IN THE WEEK...WITH LATEST RUN EUROPEAN INDICATING A
SLOWER TREND. ANOTHER BRIEF SHOT OF COLDER AIR FRIDAY INTO
SATURDAY COULD BE FOLLOWED ON ITS HEELS BY A NICE WARM UP SUNDAY
INTO NEXT WORK WEEK.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* NORTH/NORTHWEST WINDS INTO THIS EVENING...WITH A LOW CHANCE FOR
A LAKE BREEZE EARLY THIS EVENING. CMS
//DISCUSSION...UPDATED 18Z...
MAIN CONCERN FOR THIS AFTERNOON AND THIS EVENING IS THE POTENTIAL
FOR A LAKE BREEZE AND HOW FAR INLAND IT MAY MOVE. WINDS REMAIN
NORTH/NORTHEAST ALONG PARTS OF THE ILLINOIS LAKESHORE. SHORT-TERM
AND HIGH RES GUIDANCE ALL SHOW A LAKE BREEZE DEVELOPING THIS
AFTERNOON BUT HAVE EITHER SLOWED ITS PUSH INLAND ACROSS ILLINOIS
OR KEEP IT EAST OF ORD/MDW. CONFIDENCE REMAINS FAIRLY LOW AS TO
WHETHER THE LAKE BREEZE WILL ARRIVE AT ORD/MDW AND HAVE REMOVED IT
FROM THIS FORECAST. TRENDS WILL STILL NEED TO BE MONITORED THROUGH
THIS AFTERNOON WITH A SHIFT TO THE NORTHEAST STILL POSSIBLE LATE
THIS AFTERNOON/EARLY THIS EVENING. AS HIGH PRESSURE BUILDS ACROSS
THE REGION TONIGHT...WINDS WILL BECOME LIGHT AND VARIABLE/CALM IN
MOST LOCATIONS. WINDS TURN BACK LIGHT WESTERLY MONDAY MORNING
TURNING MORE SOUTHERLY MONDAY AFTERNOON. WINDS MAY CONTINUE TO
SHIFT SOUTHEASTERLY LATER IN THE AFTERNOON.
A WEAK UPPER LEVEL DISTURBANCE WILL APPROACH THE AREA LATER
MONDAY AFTERNOON AND MONDAY EVENING. POTENTIAL FOR LIGHT SNOW TO
ARRIVE AT RFD AFTER 18Z AND ORD AFTER 00Z...THUS NO MENTION IN
THIS FORECAST.
BKN STRATOCU DECK AROUND 4KFT HAS DEVELOPED OVER NORTHEAST IL AND
THIS WILL SLOWLY SCATTER OUT THROUGH THE AFTERNOON WITH INCREASING
MID CLOUDS LATER TONIGHT INTO MONDAY MORNING...LOWERING MONDAY
AFTERNOON BUT STILL REMAINING VFR. CMS
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM FOR WIND SPEEDS/DIRECTIONS THROUGH THE PERIOD...LOW FOR
POSSIBLE LAKE BREEZE REACHING ORD/MDW. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...LGT SN/MVFR LIKELY. IFR POSSIBLE.
TUESDAY...SLGT CHC LGT SN/MVFR EARLY. BECOMING VFR.
WEDNESDAY...VFR. CHC RA WED NGT.
THURSDAY...CHC RA. MVFR/IFR POSSIBLE.
FRIDAY...CHC RA MAINLY EARLY.
SATURDAY...VFR.
RATZER
&&
.MARINE...
320 AM CDT
MAIN MARINE FORECAST FOCUS IS WITH SEVERAL PERIODS OF STRONGER WINDS
IN PROGRESSIVE PATTERN OF HIGHS/TROUGHS THROUGH MID-WEEK.
NORTH WINDS WILL REMAIN BRIEFLY ELEVATED IN THE 20-25 KT RANGE ON
SOUTHERN LAKE MICHIGAN EARLY THIS MORNING...AS HIGH PRESSURE
CONTINUES TO BUILD SOUTHEAST FROM THE PLAINS INTO THE MISSISSIPPI
AND OHIO VALLEYS THROUGH TONIGHT. THE GRADIENT WILL REALLY BEGIN TO
WEAKEN BY THIS AFTERNOON...ALLOWING WINDS TO DECREASE AS THE SURFACE
RIDGE APPROACHES AND THEN CROSSES THE LAKE TONIGHT. AFTER THE RIDGE
PASSES AND MOVES EAST ON MONDAY...ANOTHER COLD FRONT WILL PUSH
SOUTHEAST ACROSS THE REGION MONDAY NIGHT AND WILL LEAD TO ANOTHER
PERIOD OF GUSTY NORTH-NORTHWEST WINDS LATE MONDAY NIGHT AND TUESDAY
AS COLD AIR AND A TIGHTENING OF THE SURFACE PRESSURE GRADIENT
COMBINE FORCES AHEAD OF ANOTHER STRONG HIGH PRESSURE AREA BUILDING
SOUTHEAST OUT OF CANADA ACROSS THE PLAINS. WINDS WILL RELAX TUESDAY
EVENING AS THE HIGH MOVES INTO THE LOWER OHIO VALLEY...WITH THE
NORTHERN PORTION OF THE RIDGE MOVING ACROSS LAKE MICHIGAN EARLY
WEDNESDAY. MEDIUM-RANGE MODEL GUIDANCE INDICATES STRONG LOW PRESSURE
DEVELOPMENT OVER THE NORTHERN HIGH PLAINS WEDNESDAY...WHICH WILL
EVENTUALLY MOVE EAST INTO THE MIDWEST/GREAT LAKES REGION THURSDAY
NIGHT AND FRIDAY. TIMING DIFFERENCES DO EXIST BETWEEN THE VARIOUS
MODELS WITH THE LOW BY THAT TIME...THOUGH IT APPEARS THAT A PERIOD
OF STRONG SOUTHERLY WINDS OF 25-30 KT IS LIKELY AHEAD OF THE LOW
LATE WEDNESDAY AND THURSDAY.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 3 PM
SUNDAY.
&&
$$
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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
1230 PM CDT Sun Mar 23 2014
.DISCUSSION...
ISSUED 949 AM CDT Sun Mar 23 2014
9 AM surface map showed sprawling 1035 MB late season Arctic high
extending south from Minnesota into northern Kansas and Missouri.
Brisk N/NNW winds continued to supply cold advection for
central/SE IL. Persistent northerly flow in the low levels has
brought a plume of Lake Michigan moisture south into eastern IL
primarily east of I-57 in the form of a broken stratocu deck.
Latest RAP forecast shows winds backing more to the NW over the
next couple hours which will allow these clouds to shift SE and
dissipate. Otherwise, sunny skies expected under subsidence
associated with the ridge axis, which shifts towards NW IL by 00Z.
This to keep NW winds going at 10-18 MPH, which combined with
unseasonably cold airmass (highs 15-20 degs below normal) will
produce wind chills in the teens this morning and 20s for most of
the afternoon.
&&
.AVIATION...
ISSUED 1230 PM CDT Sun Mar 23 2014
An area of stratocu has blossomed over eastern IL, associated with
moisture that had streamed south off Lake Michigan. Feel the bulk
of this will remain north/east of TAF sites however did include
scattered layer for KBMI/KCMI this afternoon. Ceilings could briefly
go broken at these sites at 3-4k ft. Otherwise mostly clear skies
elsewhere and through evening as high pressure ridge to our
northwest settles towards northern IL tonight. Initially brisk NNW
winds up to 15 kts this afternoon will diminish this evening,
gradually shifting around to the NE, and eventually light SE after
daybreak Monday as this high pushes east. The next disturbance
moving in from the west will spread mid clouds across central IL
late tonight, with ceilings lowering toward MVFR across the west
by 18Z/Mon. Any light snow should hold off until afternoon, but
did include VCSH at KPIA after 15Z.
25
&&
.PREV DISCUSSION...
ISSUED 302 AM CDT Sun Mar 23 2014
SHORT TERM...Today through Tuesday
High pressure will settle southward into the region today,
providing dry but unseasonably cool conditions. Mid/high clouds
currently blanketing central Illinois will shift E/SE this
morning, leaving behind sunny skies by midday. Despite full
sunshine for much of the day, continued CAA on brisk northerly
winds will keep temperatures mainly in the 30s. Clear skies/light
winds beneath the ridge axis will create excellent radiational
cooling conditions this evening before clouds begin to increase
in advance of the next storm system after midnight. As a result,
overnight low temperatures will dip into the teens across the
board.
Short-wave energy currently evident on water vapor imagery over
British Columbia will dive southeastward tonight into Monday,
spreading clouds and precip into central Illinois. 00z Mar 23
models in excellent agreement in keeping precip west of the area
until Monday afternoon. Have therefore maintained a dry forecast
Monday morning, then introduced chance POPs along/west of I-57
during the afternoon. Despite afternoon highs in the middle to
upper 30s, forecast soundings continue to show quite a bit of dry
air below 850mb, suggesting ample evaporative cooling will allow
precip to fall as snow. Strongest lift and deepest moisture
coincide during the evening, so will increase POPs to likely at
that time. With above freezing surface temps, will not see much
snow accumulation prior to sunset, but once temps drop and snow
picks up after dark, a light accumulation of 1 inch or less will
be likely.
Given fast northwesterly flow, decided to trim POPs for Tuesday
morning, with just a slight chance lingering across the eastern
KILX CWA. Blustery and cold conditions will prevail in the wake of
the storm system on Tuesday. Northwesterly winds gusting to between
25 and 30 mph will create wind-chills in the single digits and
teens as actual air temperatures struggle to rise into the lower
to middle 30s.
LONG TERM...Wednesday through Saturday
Once early week system moves eastward, upper pattern will quickly
become zonal by the middle and end of the week. This will allow a
warming trend to develop, with high temperatures climbing back to
near normal in the lower to middle 50s by Thursday and Friday.
Meanwhile, a vigorous wave is expected to come onshore along the
West Coast, then track eastward into the Midwest by Thursday.
Increasing southerly flow ahead of the system may trigger some WAA
rain showers as early as Wednesday night with better chances
arriving on Thursday. As negatively tilted upper trough and
deepening surface low approach, showers and perhaps a few
thunderstorms will become more widespread by Thursday night. Low
will lift into the Great Lakes on Friday, dragging a cold front
though central Illinois. A few showers will linger along/ahead of
the boundary on Friday followed by dry and mild weather for next
weekend.
Barnes
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1109 AM CDT SUN MAR 23 2014
.DISCUSSION...
656 AM CDT
HAD ADJUSTED POPS BASED ON TRENDS WITH LAKE EFFECT SNOW SHOWERS
TO INCLUDE CATEGORICAL THROUGH MID MORNING FOR ONGOING ACTIVITY
IN EASTERN COOK COUNTY AND LAKE/WESTERN PORTER IN INDIANA.
RECEIVED AN ESTIMATED REPORT OF 1.5 INCHES ACCUMULATED IN ROGERS
PARK...AND AREA WEB CAMS SHOW SNOW COVERED ROADWAYS AND SLOW
TRAVEL. SNOW SHOWERS SHOULD DRIFT SOUTHEAST WITH ACTIVITY FOCUSING
MORE INTO SOUTHEASTERN COOK AND NW INDIANA WITH TIME THOUGH THERE
IS SOME CONCERN PER RECENT HI-RES GUIDANCE THAT CONVERGENCE COULD
KEEP FOCUS A BIT FARTHER WEST FOR LONGER. EXPECTING UP TO AN
ADDITIONAL INCH OR SO OF SNOW BY 10 AM...WITH LOCAL AMOUNTS TO TWO
INCHES GIVEN PRESENCE OF FAIRLY HIGH REFLECTIVITY IN SNOW BAND.
LAKE EFFECT PARAMETERS SHOULD BECOME LESS FAVORABLE BEYOND MID
MORNING AS ACTIVITY SLIDES SOUTHEAST...BUT DAYSHIFT WILL NEED TO
CONTINUE TO MONITOR NEAR-TERM TRENDS. AN SPS HAS BEEN ISSUED
THROUGH 15Z TO COVER THE HAZARDS WITH THE ONGOING SNOW.
RC
//PREV DISCUSSION...
343 AM CDT
PRIMARY FORECAST CONCERNS ARE WITH LAKE EFFECT SNOW SHOWERS MAINLY
THIS MORNING OVER PORTIONS OF NW INDIANA AND POSSIBLY COOK COUNTY
IL...VERY COLD TEMPERATURES FOR LATE MARCH THROUGH MID WEEK AND
THE NEXT OPPORTUNITY FOR SNOW FROM MONDAY AFTERNOON INTO TUESDAY
MORNING.
IF YOU WOKE UP AND DIDNT KNOW WHAT TIME OF YEAR IT WAS...YOU WOULD
THINK BASED ON THE SURFACE AND UPPER PATTERN THIS MORNING THAT IT
WAS JANUARY AND NOT LATE MARCH. A DEEP COLD TROUGH IS NOTED ON W/V
CARVED OUT ACROSS THE EASTERN 2/3 OF NOAM. AT THE
SURFACE...EXPANSIVE ARCTIC HIGH PRESSURE AVERAGING 1035 MB STRETCHES
FROM THE CANADIAN PRAIRIES TO THE SOUTHERN PLAINS. 00Z RAOB PICKED
UP ON 850 MB TEMPS OF -15 AND -18C RESPECTIVELY AT GRB AND MPX
RESPECTIVELY AND IT IS THIS AIR MASS THAT IS FIRING UP LAKE EFFECT
SNOW SHOWERS AND WILL BRING US MID WINTER COLD TODAY AND TONIGHT.
REGARDING THE LAKE EFFECT: DESPITE RELYING MAINLY FROM MOISTURE FLUX
FROM COLD LAKE MAINLY IN EXTREMELY DRY AIR MASS...GOOD CONVERGENCE
AND IMPROVING THERMAL PROFILES FOR LAKE EFFECT HAVE GENERATED
ACTIVITY OVER SOUTHWESTERN PORTION OF LAKE MICHIGAN. LOCAL WRF MODEL
BASICALLY SOLE GUIDANCE THAT HAD BEEN BULLISH FOR LAKE EFFECT INTO
OUR AREA...BUT BASED ON RADAR TRENDS WILL NEED LIKELY POPS. GIVEN
CURRENT WIND CONVERGENCE SET-UP WOULD EXPECT ACITIVITY TO GENERALLY
FOCUS INTO LAKE AND PORTER COUNTIES BEFORE MOVING EAST AND
DISSIPATING. THERE COULD BE LIGHT ACCUMULATIONS ON THE ORDER OF AN
INCH OR TWO BEFORE THIS OCCURS. AM CONCERNED WITH MOST RECENT RUNS
OF RAP/HRRR GUIDANCE SUGGESTING MESO-LOW FORMATION AND
REORGANIZATION OF CONVERGENCE INTO COOK COUNTY. ALSO PURE
EXTRAPOLATION WOULD SUGGEST COOK COUNTY COULD GET CLIPPED...SO WILL
INCLUDE CHANCE POPS ON IMMEDIATE LAKEFRONT AND LET INCOMING SHIFT
MONITOR NEAR-TERM TRENDS.
TEMPERATURES TODAY AND TONIGHT: WHILE UPSTREAM OBS ARE ALREADY
EXCEPTIONAL FOR THE COLD AIR MASS PLUNGING SOUTH INTO OUR AREA
TODAY/850 MB OF -16C OR COLDER ARE IN COLDEST 1% THIS TIME OF
YEAR. NAM IS MOST BULLISH ON BRINGING CORE OF COLD TO THE
CWA...WHILE OTHER 00Z RUNS TOOK THE BRUNT OF IT JUST TO OUR EAST.
IF WE DO INDEED RECEIVE THE CORE OF THE COLD...HIGH TEMPERATURES
IN LOW 30S NORTH AND LOW-MID 30S SOUTH...WITH A FEW UPPER 20S
POSSIBLE FAR NORTH...MAY BE A HAIR TOO WARM. HOWEVER...BANKING ON
LATE MARCH SUN OUTSIDE LAKE EFFECT AREAS TO SUPPORT THE FORECAST
HIGHS. THE ARCTIC HIGH WILL BE OVERHEAD TONIGHT...BUT MID AND HIGH
CLOUDS ARE EXPECTED TO MOVE IN FROM WEST PRIOR TO DAWN. MAINTAIEND
PREVIOUS FORECAST OF MOSTLY MID TEENS OUTSIDE CHICAGO HEAT ISLAND.
IF SKIES REMAIN CLEARER LONGER...CANT RULE OUT AN ISOLATED SPOT
DOWN TO 10 OR JUST BELOW.
MONDAY THROUGH TUESDAY...WARM ADVECTION IN ADVANCE OF NEXT ARCTIC
FRONT SHOULD ENABLE TEMPERATURES TO REACH MID 30S DESPITE OVC SKIES.
GUIDANCE NOT IN BEST AGREEMENT WITH MULTIPLE SHORTWAVES IN NORTHWEST
FLOW. IT APPEARS LEAD WAVE COULD AFFECT MAINLY SOUTHWEST THIRD OF
CWA DURING AFTERNOON SO INCREASED POPS SOME. THERMAL PROFILES AND
WET BULBS SUPPORT SNOW AS PTYPE. INCREASED POPS TO LIKELY FOR THE
ENTIRE CWA MONDAY NIGHT...BUT CONFIDENCE IS NOT THE HIGHEST IN EXACT
EVOLUTION. LOOKS OVERALL TO BE A HIGH POP/LOW QPF SCENARIO...WITH
FORCING FROM MULTIPLE WAVES AND THERE POSSIBLY BEING A MINIMA IN
THIS SOMEWHERE OVER CWA. TOTAL SNOWFALL ACCUMULATIONS COULD END UP
IN 1-2 INCH RANGE...THOUGH COVERAGE MAY BE A BIT LESS BROAD THAN IN
CURRENT FORECAST. ARCTIC FRONT TRAILING FROM WEAK LOW OVER WISCONSIN
WILL SWEEP ACROSS THE AREA OVERNIGHT INTO TUESDAY MORNING...SETTING
THE STAGE FOR ANOTHER EXTREMELY COLD DAY...WITH HIGHS STRUGGLING TO
REACH FREEZING IN -16 TO -19 AT 850 MB AIRMASS.
TUESDAY NIGHT THROUGH FRIDAY...PATTERN WILL THEN QUICKLY SHIFT TO
RIDGING OVER CENTRAL CONUS AS IMPRESSIVELY DEEP SYSTEM OFF EAST
COAST AMPLIFIES THE PATTERN. HIGHS SHOULD RECOVER TO 35-40 ON
WEDNESDAY THANKS TO WAA AFTER MOST AREAS PLUMMET INTO TEENS BY
DAWN WEDS UNDER ARCTIC HIGH. FAIRLY DEEP TROUGH WILL THEN EJECT
ACROSS ROCKIES AND HIGH PLAINS BY EARLY THURSDAY...KEEPING
DOWNSTREAM RIDGE AMPLIFIED AND CAUSING STRONG SURFACE
CYCLOGENESIS. GUIDANCE IN GOOD AGREEMENT ON BRINGING THIS SYSTEM
WEST OF CWA...KEEPING US ON WARM SIDE AND PERIODS OF RAIN LIKELY
LATER THURSDAY INTO THURSDAY NIGHT. MOISTURE RETURN DOESNT APPEAR
ALL THAT IMPRESSIVE TO SUPPORT THUNDER CHANCES AT THIS
TIME...THOUGH STRONG ENOUGH SYSTEM COULD COMPENSATE WITH GOOD
DYNAMICS. DIFFERENCES THEN INCREASE ON HOW FAST SYSTEM MOVES TO
EAST LATER IN THE WEEK...WITH LATEST RUN EUROPEAN INDICATING A
SLOWER TREND. ANOTHER BRIEF SHOT OF COLDER AIR FRIDAY INTO
SATURDAY COULD BE FOLLOWED ON ITS HEELS BY A NICE WARM UP SUNDAY
INTO NEXT WORK WEEK.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* NORTHERLY WINDS THROUGH LATE AFTERNOON...WITH A POSSIBLE LAKE
BREEZE AT MDW AROUND 23Z...AND ORD 00Z-01Z. CMS
//DISCUSSION...UPDATED 16Z...
AS HIGH PRESSURE BUILDS ACROSS THE REGION THIS AFTERNOON AND THIS
EVENING...WINDS WILL SLOWLY DIMINISH. EXPECT WINDS TO TURN MORE
NORTHEAST NEAR THE LAKE THIS AFTERNOON WITH THIS LAKE BREEZE
MOVING INLAND THROUGH THE LATE AFTERNOON AND EARLY EVENING. FAIRLY
LOW CONFIDENCE REGARDING WHEN OR IF IT WILL REACH ORD...AND HAVE
DELAYED ARRIVAL AT ORD UNTIL 01Z WITH THIS UPDATE. CMS
PREVIOUS 12Z DISCUSSION...
LAKE EFFECT SNOW SHOWERS AFFECTING NORTHWEST INDIANA AND COOK
COUNTY IL EARLY THIS AM WITH REINFORCING PUSH OF COLDER AIR ALOFT.
SNOW SHOWERS ABOUT AS FAR INLAND AS MDW...WITH MVFR CIG AND
POTENTIAL BRIEF MVFR VIS POSSIBLE THERE. SNOW SHOWERS EXPECTED TO
REMAIN GENERALLY EAST OF ORD...WITH PERHAPS A FEW FLURRIES AND
BRIEF MVFR CIG THERE THOUGH APPROACHES FROM THE EAST WILL BE
THROUGH SNOW SHOWERS. ACTIVITY SHOULD WEAKEN AND DRIFT EAST-
SOUTHEAST AFTER MID-MORNING WITH VFR CONDITIONS THIS AFTERNOON
WEST OF THE LAKE. WARM ADVECTION AHEAD OF NEXT SYSTEM WILL RESULT
IN VFR MID/HIGH CLOUDS DEVELOPING LATE TONIGHT.
NORTH-NORTHWEST WINDS STILL SHOWING OCCASIONAL GUSTS AROUND 15 KT
EARLY THIS AM...THOUGH GRADIENT WILL SLOWLY WEAKEN AS HIGH
PRESSURE WEST OF THE MISSISSIPPI DEVELOPS EASTWARD LATER TODAY.
SOME GUIDANCE CONTINUES TO INDICATE A POTENTIAL WIND SHIFT TO THE
NORTH-NORTHEAST ORD/MDW/GYY LATE AFTERNOON/EARLY EVENING AS
GRADIENT WEAKENS...THOUGH CONFIDENCE IN WIND DIRECTION DIMINISHES
BY THAT TIME. WINDS SHOULD BECOME LIGHT NORTHWEST OR VARIABLE
OVERNIGHT BEFORE BACKING LIGHT WEST-SOUTHWEST LATER MONDAY
MORNING.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM FOR WIND SPEEDS/DIRECTIONS THROUGH THE PERIOD.
* HIGH FOR A LAKE BREEZE FORMING THIS AFTERNOON...LOW FOR TIMING/
ARRIVAL AT ORD/MDW. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...LGT SN/MVFR LIKELY. IFR POSSIBLE.
TUESDAY...SLGT CHC LGT SN/MVFR EARLY. BECOMING VFR.
WEDNESDAY...VFR. CHC RA WED NGT.
THURSDAY...CHC RA. MVFR/IFR POSSIBLE.
FRIDAY...CHC RA MAINLY EARLY.
SATURDAY...VFR.
RATZER
&&
.MARINE...
320 AM CDT
MAIN MARINE FORECAST FOCUS IS WITH SEVERAL PERIODS OF STRONGER WINDS
IN PROGRESSIVE PATTERN OF HIGHS/TROUGHS THROUGH MID-WEEK.
NORTH WINDS WILL REMAIN BRIEFLY ELEVATED IN THE 20-25 KT RANGE ON
SOUTHERN LAKE MICHIGAN EARLY THIS MORNING...AS HIGH PRESSURE
CONTINUES TO BUILD SOUTHEAST FROM THE PLAINS INTO THE MISSISSIPPI
AND OHIO VALLEYS THROUGH TONIGHT. THE GRADIENT WILL REALLY BEGIN TO
WEAKEN BY THIS AFTERNOON...ALLOWING WINDS TO DECREASE AS THE SURFACE
RIDGE APPROACHES AND THEN CROSSES THE LAKE TONIGHT. AFTER THE RIDGE
PASSES AND MOVES EAST ON MONDAY...ANOTHER COLD FRONT WILL PUSH
SOUTHEAST ACROSS THE REGION MONDAY NIGHT AND WILL LEAD TO ANOTHER
PERIOD OF GUSTY NORTH-NORTHWEST WINDS LATE MONDAY NIGHT AND TUESDAY
AS COLD AIR AND A TIGHTENING OF THE SURFACE PRESSURE GRADIENT
COMBINE FORCES AHEAD OF ANOTHER STRONG HIGH PRESSURE AREA BUILDING
SOUTHEAST OUT OF CANADA ACROSS THE PLAINS. WINDS WILL RELAX TUESDAY
EVENING AS THE HIGH MOVES INTO THE LOWER OHIO VALLEY...WITH THE
NORTHERN PORTION OF THE RIDGE MOVING ACROSS LAKE MICHIGAN EARLY
WEDNESDAY. MEDIUM-RANGE MODEL GUIDANCE INDICATES STRONG LOW PRESSURE
DEVELOPMENT OVER THE NORTHERN HIGH PLAINS WEDNESDAY...WHICH WILL
EVENTUALLY MOVE EAST INTO THE MIDWEST/GREAT LAKES REGION THURSDAY
NIGHT AND FRIDAY. TIMING DIFFERENCES DO EXIST BETWEEN THE VARIOUS
MODELS WITH THE LOW BY THAT TIME...THOUGH IT APPEARS THAT A PERIOD
OF STRONG SOUTHERLY WINDS OF 25-30 KT IS LIKELY AHEAD OF THE LOW
LATE WEDNESDAY AND THURSDAY.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 3 PM
SUNDAY.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
949 AM CDT Sun Mar 23 2014
.DISCUSSION...
ISSUED 949 AM CDT Sun Mar 23 2014
9 AM surface map showed sprawling 1035 MB late season Arctic high
extending south from Minnesota into northern Kansas and Missouri.
Brisk N/NNW winds continued to supply cold advection for
central/SE IL. Persistent northerly flow in the low levels has
brought a plume of Lake Michigan moisture south into eastern IL
primarily east of I-57 in the form of a broken stratocu deck.
Latest RAP forecast shows winds backing more to the NW over the
next couple hours which will allow these clouds to shift SE and
dissipate. Otherwise, sunny skies expected under subsidence
associated with the ridge axis, which shifts towards NW IL by 00Z.
This to keep NW winds going at 10-18 MPH, which combined with
unseasonably cold airmass (highs 15-20 degs below normal) will
produce wind chills in the teens this morning and 20s for most of
the afternoon.
25
&&
.AVIATION...
ISSUED 658 AM CDT Sun Mar 23 2014
Quiet/predominantly VFR weather conditions expected across the
central Illinois terminals through the 12Z TAF valid time. The
main exception is for a few hours this morning at KCMI, where a
MVFR cig may sneak in off Lake Michigan at times. Northerly winds,
gusty at times today, will trend northeast and diminish tonight as
a ridge of high pressure passes through the area.
Bak
&&
.PREV DISCUSSION...
ISSUED 302 AM CDT Sun Mar 23 2014
SHORT TERM...Today through Tuesday
High pressure will settle southward into the region today,
providing dry but unseasonably cool conditions. Mid/high clouds
currently blanketing central Illinois will shift E/SE this
morning, leaving behind sunny skies by midday. Despite full
sunshine for much of the day, continued CAA on brisk northerly
winds will keep temperatures mainly in the 30s. Clear skies/light
winds beneath the ridge axis will create excellent radiational
cooling conditions this evening before clouds begin to increase
in advance of the next storm system after midnight. As a result,
overnight low temperatures will dip into the teens across the
board.
Short-wave energy currently evident on water vapor imagery over
British Columbia will dive southeastward tonight into Monday,
spreading clouds and precip into central Illinois. 00z Mar 23
models in excellent agreement in keeping precip west of the area
until Monday afternoon. Have therefore maintained a dry forecast
Monday morning, then introduced chance POPs along/west of I-57
during the afternoon. Despite afternoon highs in the middle to
upper 30s, forecast soundings continue to show quite a bit of dry
air below 850mb, suggesting ample evaporative cooling will allow
precip to fall as snow. Strongest lift and deepest moisture
coincide during the evening, so will increase POPs to likely at
that time. With above freezing surface temps, will not see much
snow accumulation prior to sunset, but once temps drop and snow
picks up after dark, a light accumulation of 1 inch or less will
be likely.
Given fast northwesterly flow, decided to trim POPs for Tuesday
morning, with just a slight chance lingering across the eastern
KILX CWA. Blustery and cold conditions will prevail in the wake of
the storm system on Tuesday. Northwesterly winds gusting to between
25 and 30 mph will create wind-chills in the single digits and
teens as actual air temperatures struggle to rise into the lower
to middle 30s.
LONG TERM...Wednesday through Saturday
Once early week system moves eastward, upper pattern will quickly
become zonal by the middle and end of the week. This will allow a
warming trend to develop, with high temperatures climbing back to
near normal in the lower to middle 50s by Thursday and Friday.
Meanwhile, a vigorous wave is expected to come onshore along the
West Coast, then track eastward into the Midwest by Thursday.
Increasing southerly flow ahead of the system may trigger some WAA
rain showers as early as Wednesday night with better chances
arriving on Thursday. As negatively tilted upper trough and
deepening surface low approach, showers and perhaps a few
thunderstorms will become more widespread by Thursday night. Low
will lift into the Great Lakes on Friday, dragging a cold front
though central Illinois. A few showers will linger along/ahead of
the boundary on Friday followed by dry and mild weather for next
weekend.
Barnes
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
320 AM CDT SUN MAR 23 2014
.DISCUSSION...
340 PM CDT
A PROGRESSIVE PATTERN PERSISTS THIS WEEK IN ZONAL TO SOMEWHAT
NORTHWESTERLY FLOW...WITH TEMPERATURE TRENDS AND PRECIPITATION
CHANCES CONTINUING TO VARY GREATLY DAY TO DAY.
HIGH PRESSURE MOVING IN TONIGHT WILL TURN WINDS MORE NORTHERLY AND
SUPPORT A LONG FETCH OVER THE SOUTHERN LAKE INTO LOWER MICHIGAN AND
NORTHWEST INDIANA. HIGHER RESOLUTION MODELS ARE SUGGESTING THE
DEVELOPMENT OF LAKE EFFECT SNOW SHOWERS LATER THIS EVENING AND
OVERNIGHT...BUT SETUP DOES NOT APPEAR TO BE IDEAL. MOISTURE IS
QUITE LIMITED UNDER THE INFLUENCE OF THE HIGH...WITH SINGLE DIGIT
DEWPOINTS UPSTREAM AND LITTLE IN THE WAY OF SUPPORTIVE SATURATION
ALOFT. THE LAKE ITSELF AS A SOURCE OF MOISTURE IS QUESTIONABLE
GIVEN THE EXTENSIVE ICE COVER OVER THE PORTION OF THE LAKE ADJACENT
TO THE AREA OF CONCERN. GIVEN THESE QUESTIONS...HAVE MAINTAINED LOW
CHANCE POPS FOR MOST OF THE NIGHT INTO TOMORROW WITH AROUND AN INCH
OF SNOW POSSIBLE.
PERSISTENT NORTH WINDS SUNDAY WILL KEEP THE DAY ABOUT 20 DEGREES
COOLER THAN NORMAL...THEN SUNDAY NIGHT THE HIGH MOVES OVERHEAD AND
DESPITE THE RECENT DECREASE IN SNOW COVER...CLEAR SKIES AND LIGHT
WINDS WILL SUPPORT LOWS IN THE TEENS AND POSSIBLY EVEN SINGLE
DIGITS IN THE LOWEST LYING SHELTERED AREAS. THE RECORD LOW FOR
MONDAY IN CHICAGO IS 5 DEGREES AND IN ROCKFORD IS 1 BUT THOSE DO
NOT APPEAR TO BE IN DANGER OF BEING BROKEN. RECORD COLD HIGHS ARE
AROUND 20 THIS TIME OF YEAR...AND THOSE ALSO APPEAR SAFE FOR NOW.
UNSEASONABLY COLD HIGHS CONTINUE MONDAY AND TUESDAY...AND THE NEXT
BEST CHANCE OF WINTER PRECIPITATION AFTER TONIGHT COMES MONDAY NIGHT
INTO TUESDAY. DETERMINISTIC MODELS DISAGREE IN THE STRENGTH OF A
SHORTWAVE PASSING THROUGH ALOFT...AND THE POSITION OF THE ASSOCIATED
SURFACE LOW...BUT ALL AGREE ON THE PASSAGE OF AT LEAST A WEAK
DISTURBANCE ACROSS THE AREA DURING THIS PERIOD. AM NOT CONFIDENT
ENOUGH TO GO WITH THE NAM AND PUT IN 3-4 INCHES OF SNOW FOR PART OF
THE AREA...SO HAVE STAYED WITH A BLEND OF POPS IN THE HIGH CHANCE
CATEGORY.
HIGH PRESSURE QUICKLY FOLLOWS ON WEDNESDAY...AND IF PROGRESSIVE
ENOUGH WILL BRING CLEARING SKIES AND SOUTHERLY FLOW FOR MOST OF THE
DAY. TEMPERATURES ARE NOT LIKELY TO REBOUND SIGNIFICANTLY AFTER THE
COLD START TO THE WEEK...BUT SHOULD AT LEAST REACH INTO THE UPPER
30S OR LOWER 40S AND POSSIBLY HIGHER IF THE RIDGE CAN WORK ITS WAY
EAST EARLIER IN THE DAY.
THURSDAY AND PERHAPS FRIDAY LOOK TO BE THE WARMEST DAYS OF THE
WEEK. WEDNESDAYS RIDGE IS WELL TO THE EAST AND THE NEXT LOW
PRESSURE SYSTEM IS APPROACHING FROM THE PLAINS. WARM ADVECTION
AHEAD OF THE LOW WILL SUPPORT INCREASING TEMPERATURES AND MOISTURE.
IF THE ASSOCIATED COLD FRONT CAN HOLD OFF TILL LATER FRIDAY THEN
BOTH DAYS WILL BE RELATIVELY MILD THOUGH BREEZY. SATURDAY THEN COOLS
OFF AGAIN UNDER POST FRONTAL NORTHERLY FLOW BUT CLEARING SKIES AND
LATE MARCH SUNSHINE MAY ALLOW AREAS AWAY FROM THE LAKE TO WARM UP
A BIT DURING THE AFTERNOON.
LENNING
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* NORTH-NORTHWEST WINDS WITH A FEW SPORADIC GUSTS 15-20 KT EARLY
THIS MORNING DIMINISHING AND POSSIBLY BECOMING NORTHEAST BY LATE
AFTERNOON.
* POTENTIAL FOR BRIEF MVFR CEILING EARLY THIS AM ALONG WESTERN
FRINGE OF LAKE EFFECT CLOUD PLUME INTO IL/IN STATE LINE AND GYY
AREA.
* WINDS BECOME LIGHT/VARIABLE THIS EVENING/TONIGHT AS SFC HIGH
MOVES ACROSS AREA.
RATZER
//DISCUSSION...UPDATED 06Z...
NORTH-NORTHWEST WINDS EXPECTED TO CONTINUE EARLY THIS MORNING
WITH A FEW SPORADIC GUSTS IN THE 15-20 KT RANGE...THOUGH SPEEDS
WILL GRADUALLY DECREASE INTO THIS AFTERNOON AS GRADIENT WEAKENS
WITH APPROACH OF SURFACE HIGH PRESSURE CENTER FROM THE NORTHWEST.
CONVERGENT SURFACE WIND FIELD APPEARS TO BE TAKING SHAPE JUST EAST
OF THE ILLINOIS LAKE SHORE INTO THE GYY AREA AT 05Z...SUGGESTING
FOCUS OF LAKE EFFECT CLOUDS AND POTENTIAL SNOW SHOWERS SHOULD
REMAIN EAST OF ORD/MDW. TEMPS CONTINUE TO COOL ALOFT WITH
NORTHERLY FLOW...AND WEAK RADAR RETURNS HAVE DEVELOPED OVER LAKE
IN THE PAST COUPLE OF HOURS. ANTICIPATE A PERIOD OF LIGHT LAKE
EFFECT SHSN WILL AFFECT GARY DURING THE MORNING HOURS...AND HAVE
INDICATED TEMPO MVFR CONDITIONS THERE AND WILL HAVE TO MONITOR
RADAR TRENDS FOR POSSIBLY LOWER VIS CONDITIONS IF SHSN INTENSIFY
SUFFICIENTLY. HIGH RES RAP/HRRR APPEAR TO BE HANDLING SFC WIND
FIELD THE BEST...WITH OUR LOCAL 8 KM WRF LOOKING SIMILAR IN THE BY
09Z-12Z. THESE MODELS SUGGEST LAKE EFFECT BAND WOULD EVENTUALLY
MIGRATE EAST OF GYY BY MID/LATE MORNING. OTHERWISE...ORD/MDW
SHOULD REMAIN ALONG WESTERN FRINGE OF LAKE CLOUDS...WITH MAINLY
VFR CIGS EXPECTED.
WEAKENING PRESSURE GRADIENT THIS AFTERNOON SHOULD ALLOW NORTH-
NORTHWEST WINDS TO TURN TO THE NORTHEAST ALONG THE IL LAKE SHORE.
SEVERAL MODELS HINT AT NORTHEAST WINDS DEVELOPING AS FAR INLAND AS
ORD/MDW PRIOR TO 00Z. EXPECT THIS WILL OCCUR...THOUGH INLAND PUSH
AND POSITION/TIMING RELATIVE TO ORD/MDW ARE LOW CONFIDENCE DETAILS
AT THIS DISTANCE.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM-HIGH CONFIDENCE IN PREVAILING VFR AS MVFR CIGS WITH LAKE
EFFECT EXPECTED TO REMAIN MAINLY OFF TO EAST OF ORD/MDW THIS
MORNING.
* HIGH CONFIDENCE IN WINDS THROUGH MID-DAY...THEN DECREASING
CONFIDENCE IN OCCURRENCE/TIMING OF POTENTIAL SHIFT TO NORTHEAST
OFF LAKE BY LATE AFTERNOON.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR...THEN CHC -SN/MVFR MONDAY EVE/NIGHT.
TUESDAY...CHC-SN/MVFR EARLY...OTHERWISE VFR.
WEDNESDAY...SLGT CHC -SN. MVFR POSSIBLE.
THURSDAY AND FRIDAY...CHC -RA/MVFR.
MDB
&&
.MARINE...
320 AM CDT
MAIN MARINE FORECAST FOCUS IS WITH SEVERAL PERIODS OF STRONGER WINDS
IN PROGRESSIVE PATTERN OF HIGHS/TROUGHS THROUGH MID-WEEK.
NORTH WINDS WILL REMAIN BRIEFLY ELEVATED IN THE 20-25 KT RANGE ON
SOUTHERN LAKE MICHIGAN EARLY THIS MORNING...AS HIGH PRESSURE
CONTINUES TO BUILD SOUTHEAST FROM THE PLAINS INTO THE MISSISSIPPI
AND OHIO VALLEYS THROUGH TONIGHT. THE GRADIENT WILL REALLY BEGIN TO
WEAKEN BY THIS AFTERNOON...ALLOWING WINDS TO DECREASE AS THE SURFACE
RIDGE APPROACHES AND THEN CROSSES THE LAKE TONIGHT. AFTER THE RIDGE
PASSES AND MOVES EAST ON MONDAY...ANOTHER COLD FRONT WILL PUSH
SOUTHEAST ACROSS THE REGION MONDAY NIGHT AND WILL LEAD TO ANOTHER
PERIOD OF GUSTY NORTH-NORTHWEST WINDS LATE MONDAY NIGHT AND TUESDAY
AS COLD AIR AND A TIGHTENING OF THE SURFACE PRESSURE GRADIENT
COMBINE FORCES AHEAD OF ANOTHER STRONG HIGH PRESSURE AREA BUILDING
SOUTHEAST OUT OF CANADA ACROSS THE PLAINS. WINDS WILL RELAX TUESDAY
EVENING AS THE HIGH MOVES INTO THE LOWER OHIO VALLEY...WITH THE
NORTHERN PORTION OF THE RIDGE MOVING ACROSS LAKE MICHIGAN EARLY
WEDNESDAY. MEDIUM-RANGE MODEL GUIDANCE INDICATES STRONG LOW PRESSURE
DEVELOPMENT OVER THE NORTHERN HIGH PLAINS WEDNESDAY...WHICH WILL
EVENTUALLY MOVE EAST INTO THE MIDWEST/GREAT LAKES REGION THURSDAY
NIGHT AND FRIDAY. TIMING DIFFERENCES DO EXIST BETWEEN THE VARIOUS
MODELS WITH THE LOW BY THAT TIME...THOUGH IT APPEARS THAT A PERIOD
OF STRONG SOUTHERLY WINDS OF 25-30 KT IS LIKELY AHEAD OF THE LOW
LATE WEDNESDAY AND THURSDAY.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 AM SUNDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
National Weather Service Lincoln IL
302 AM CDT Sun Mar 23 2014
.DISCUSSION...
ISSUED 302 AM CDT Sun Mar 23 2014
SHORT TERM...Today through Tuesday
High pressure will settle southward into the region today,
providing dry but unseasonably cool conditions. Mid/high clouds
currently blanketing central Illinois will shift E/SE this
morning, leaving behind sunny skies by midday. Despite full
sunshine for much of the day, continued CAA on brisk northerly
winds will keep temperatures mainly in the 30s. Clear skies/light
winds beneath the ridge axis will create excellent radiational
cooling conditions this evening before clouds begin to increase
in advance of the next storm system after midnight. As a result,
overnight low temperatures will dip into the teens across the
board.
Short-wave energy currently evident on water vapor imagery over
British Columbia will dive southeastward tonight into Monday,
spreading clouds and precip into central Illinois. 00z Mar 23
models in excellent agreement in keeping precip west of the area
until Monday afternoon. Have therefore maintained a dry forecast
Monday morning, then introduced chance POPs along/west of I-57
during the afternoon. Despite afternoon highs in the middle to
upper 30s, forecast soundings continue to show quite a bit of dry
air below 850mb, suggesting ample evaporative cooling will allow
precip to fall as snow. Strongest lift and deepest moisture
coincide during the evening, so will increase POPs to likely at
that time. With above freezing surface temps, will not see much
snow accumulation prior to sunset, but once temps drop and snow
picks up after dark, a light accumulation of 1 inch or less will
be likely.
Given fast northwesterly flow, decided to trim POPs for Tuesday
morning, with just a slight chance lingering across the eastern
KILX CWA. Blustery and cold conditions will prevail in the wake of
the storm system on Tuesday. Northwesterly winds gusting to between
25 and 30 mph will create wind-chills in the single digits and
teens as actual air temperatures struggle to rise into the lower
to middle 30s.
LONG TERM...Wednesday through Saturday
Once early week system moves eastward, upper pattern will quickly
become zonal by the middle and end of the week. This will allow a
warming trend to develop, with high temperatures climbing back to
near normal in the lower to middle 50s by Thursday and Friday.
Meanwhile, a vigorous wave is expected to come onshore along the
West Coast, then track eastward into the Midwest by Thursday.
Increasing southerly flow ahead of the system may trigger some WAA
rain showers as early as Wednesday night with better chances
arriving on Thursday. As negatively tilted upper trough and
deepening surface low approach, showers and perhaps a few
thunderstorms will become more widespread by Thursday night. Low
will lift into the Great Lakes on Friday, dragging a cold front
though central Illinois. A few showers will linger along/ahead of
the boundary on Friday followed by dry and mild weather for next
weekend.
Barnes
&&
.AVIATION...
ISSUED 1141 PM CDT Sat Mar 22 2014
VFR clouds at 10k to 12k FT will continue to stream across C IL
from the west in the fast jet stream flow. Surface winds will turn
more northerly as the surface high pressure builds into IL. That
northerly flow may drag some lake effect clouds toward our eastern
CWA after midnight. Those clouds should generally be around 2.5k
to 3.5k FT and arrive after 09z as depicted by the RAP and HRRR,
with some support from the NAM as well. That period of low clouds
could linger until mid to late morning on Sunday before dry air
closer to the center of the high finally dissipates the majority
of our cloud cover. The remainder of Sunday should be mostly clear
with just some cirrus Sunday afternoon and evening.
The surface pressure gradient and pressure rises will continue to
create NW winds in the 10-15kt range the rest of tonight and through
most of the day tomorrow. By sunset, winds should decouple as the
surface ridge axis pushes into IL.
Shimon
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1252 AM CDT SUN MAR 23 2014
.DISCUSSION...
340 PM CDT
A PROGRESSIVE PATTERN PERSISTS THIS WEEK IN ZONAL TO SOMEWHAT
NORTHWESTERLY FLOW...WITH TEMPERATURE TRENDS AND PRECIPITATION
CHANCES CONTINUING TO VARY GREATLY DAY TO DAY.
HIGH PRESSURE MOVING IN TONIGHT WILL TURN WINDS MORE NORTHERLY AND
SUPPORT A LONG FETCH OVER THE SOUTHERN LAKE INTO LOWER MICHIGAN AND
NORTHWEST INDIANA. HIGHER RESOLUTION MODELS ARE SUGGESTING THE
DEVELOPMENT OF LAKE EFFECT SNOW SHOWERS LATER THIS EVENING AND
OVERNIGHT...BUT SETUP DOES NOT APPEAR TO BE IDEAL. MOISTURE IS
QUITE LIMITED UNDER THE INFLUENCE OF THE HIGH...WITH SINGLE DIGIT
DEWPOINTS UPSTREAM AND LITTLE IN THE WAY OF SUPPORTIVE SATURATION
ALOFT. THE LAKE ITSELF AS A SOURCE OF MOISTURE IS QUESTIONABLE
GIVEN THE EXTENSIVE ICE COVER OVER THE PORTION OF THE LAKE ADJACENT
TO THE AREA OF CONCERN. GIVEN THESE QUESTIONS...HAVE MAINTAINED LOW
CHANCE POPS FOR MOST OF THE NIGHT INTO TOMORROW WITH AROUND AN INCH
OF SNOW POSSIBLE.
PERSISTENT NORTH WINDS SUNDAY WILL KEEP THE DAY ABOUT 20 DEGREES
COOLER THAN NORMAL...THEN SUNDAY NIGHT THE HIGH MOVES OVERHEAD AND
DESPITE THE RECENT DECREASE IN SNOW COVER...CLEAR SKIES AND LIGHT
WINDS WILL SUPPORT LOWS IN THE TEENS AND POSSIBLY EVEN SINGLE
DIGITS IN THE LOWEST LYING SHELTERED AREAS. THE RECORD LOW FOR
MONDAY IN CHICAGO IS 5 DEGREES AND IN ROCKFORD IS 1 BUT THOSE DO
NOT APPEAR TO BE IN DANGER OF BEING BROKEN. RECORD COLD HIGHS ARE
AROUND 20 THIS TIME OF YEAR...AND THOSE ALSO APPEAR SAFE FOR NOW.
UNSEASONABLY COLD HIGHS CONTINUE MONDAY AND TUESDAY...AND THE NEXT
BEST CHANCE OF WINTER PRECIPITATION AFTER TONIGHT COMES MONDAY NIGHT
INTO TUESDAY. DETERMINISTIC MODELS DISAGREE IN THE STRENGTH OF A
SHORTWAVE PASSING THROUGH ALOFT...AND THE POSITION OF THE ASSOCIATED
SURFACE LOW...BUT ALL AGREE ON THE PASSAGE OF AT LEAST A WEAK
DISTURBANCE ACROSS THE AREA DURING THIS PERIOD. AM NOT CONFIDENT
ENOUGH TO GO WITH THE NAM AND PUT IN 3-4 INCHES OF SNOW FOR PART OF
THE AREA...SO HAVE STAYED WITH A BLEND OF POPS IN THE HIGH CHANCE
CATEGORY.
HIGH PRESSURE QUICKLY FOLLOWS ON WEDNESDAY...AND IF PROGRESSIVE
ENOUGH WILL BRING CLEARING SKIES AND SOUTHERLY FLOW FOR MOST OF THE
DAY. TEMPERATURES ARE NOT LIKELY TO REBOUND SIGNIFICANTLY AFTER THE
COLD START TO THE WEEK...BUT SHOULD AT LEAST REACH INTO THE UPPER
30S OR LOWER 40S AND POSSIBLY HIGHER IF THE RIDGE CAN WORK ITS WAY
EAST EARLIER IN THE DAY.
THURSDAY AND PERHAPS FRIDAY LOOK TO BE THE WARMEST DAYS OF THE
WEEK. WEDNESDAYS RIDGE IS WELL TO THE EAST AND THE NEXT LOW
PRESSURE SYSTEM IS APPROACHING FROM THE PLAINS. WARM ADVECTION
AHEAD OF THE LOW WILL SUPPORT INCREASING TEMPERATURES AND MOISTURE.
IF THE ASSOCIATED COLD FRONT CAN HOLD OFF TILL LATER FRIDAY THEN
BOTH DAYS WILL BE RELATIVELY MILD THOUGH BREEZY. SATURDAY THEN COOLS
OFF AGAIN UNDER POST FRONTAL NORTHERLY FLOW BUT CLEARING SKIES AND
LATE MARCH SUNSHINE MAY ALLOW AREAS AWAY FROM THE LAKE TO WARM UP
A BIT DURING THE AFTERNOON.
LENNING
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* NORTH-NORTHWEST WINDS WITH A FEW SPORADIC GUSTS 15-20 KT EARLY
THIS MORNING DIMINISHING AND POSSIBLY BECOMING NORTHEAST BY LATE
AFTERNOON.
* POTENTIAL FOR BRIEF MVFR CEILING EARLY THIS AM ALONG WESTERN
FRINGE OF LAKE EFFECT CLOUD PLUME INTO IL/IN STATE LINE AND GYY
AREA.
* WINDS BECOME LIGHT/VARIABLE THIS EVENING/TONIGHT AS SFC HIGH
MOVES ACROSS AREA.
RATZER
//DISCUSSION...UPDATED 06Z...
NORTH-NORTHWEST WINDS EXPECTED TO CONTINUE EARLY THIS MORNING
WITH A FEW SPORADIC GUSTS IN THE 15-20 KT RANGE...THOUGH SPEEDS
WILL GRADUALLY DECREASE INTO THIS AFTERNOON AS GRADIENT WEAKENS
WITH APPROACH OF SURFACE HIGH PRESSURE CENTER FROM THE NORTHWEST.
CONVERGENT SURFACE WIND FIELD APPEARS TO BE TAKING SHAPE JUST EAST
OF THE ILLINOIS LAKE SHORE INTO THE GYY AREA AT 05Z...SUGGESTING
FOCUS OF LAKE EFFECT CLOUDS AND POTENTIAL SNOW SHOWERS SHOULD
REMAIN EAST OF ORD/MDW. TEMPS CONTINUE TO COOL ALOFT WITH
NORTHERLY FLOW...AND WEAK RADAR RETURNS HAVE DEVELOPED OVER LAKE
IN THE PAST COUPLE OF HOURS. ANTICIPATE A PERIOD OF LIGHT LAKE
EFFECT SHSN WILL AFFECT GARY DURING THE MORNING HOURS...AND HAVE
INDICATED TEMPO MVFR CONDITIONS THERE AND WILL HAVE TO MONITOR
RADAR TRENDS FOR POSSIBLY LOWER VIS CONDITIONS IF SHSN INTENSIFY
SUFFICIENTLY. HIGH RES RAP/HRRR APPEAR TO BE HANDLING SFC WIND
FIELD THE BEST...WITH OUR LOCAL 8 KM WRF LOOKING SIMILAR IN THE BY
09Z-12Z. THESE MODELS SUGGEST LAKE EFFECT BAND WOULD EVENTUALLY
MIGRATE EAST OF GYY BY MID/LATE MORNING. OTHERWISE...ORD/MDW
SHOULD REMAIN ALONG WESTERN FRINGE OF LAKE CLOUDS...WITH MAINLY
VFR CIGS EXPECTED.
WEAKENING PRESSURE GRADIENT THIS AFTERNOON SHOULD ALLOW NORTH-
NORTHWEST WINDS TO TURN TO THE NORTHEAST ALONG THE IL LAKE SHORE.
SEVERAL MODELS HINT AT NORTHEAST WINDS DEVELOPING AS FAR INLAND AS
ORD/MDW PRIOR TO 00Z. EXPECT THIS WILL OCCUR...THOUGH INLAND PUSH
AND POSITION/TIMING RELATIVE TO ORD/MDW ARE LOW CONFIDENCE DETAILS
AT THIS DISTANCE.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM-HIGH CONFIDENCE IN PREVAILING VFR AS MVFR CIGS WITH LAKE
EFFECT EXPECTED TO REMAIN MAINLY OFF TO EAST OF ORD/MDW THIS
MORNING.
* HIGH CONFIDENCE IN WINDS THROUGH MID-DAY...THEN DECREASING
CONFIDENCE IN OCCURRENCE/TIMING OF POTENTIAL SHIFT TO NORTHEAST
OFF LAKE BY LATE AFTERNOON.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR...THEN CHC -SN/MVFR MONDAY EVE/NIGHT.
TUESDAY...CHC-SN/MVFR EARLY...OTHERWISE VFR.
WEDNESDAY...SLGT CHC -SN. MVFR POSSIBLE.
THURSDAY AND FRIDAY...CHC -RA/MVFR.
MDB
&&
.MARINE...
324 PM CDT
WITH A TROUGH OF LOW PRESSURE OVER THE EASTERN GREAT LAKES AND
LARGE HIGH PRESSURE SLOWLY SPREADING SOUTH ACROSS THE NORTHERN
PLAINS...A PERIOD OF NORTH TO NORTHWEST WINDS WILL OCCUR OVER THE
LAKE THROUGH THE REMAINDER OF THE WEEKEND. WIND SPEEDS HAVE VARIED
OVER THE LAKE TODAY AND CONTINUE TO VARY THIS AFTERNOON...BUT WITH
SPEEDS OVER THE LAKE LIKELY BECOMING MORE UNIFORM AS THE PRESSURE
GRADIENT ON THE EASTERN FRINGE OF THIS HIGH MOVES OVERHEAD. THIS
WILL ALLOW FOR THE NORTH/NORTHWEST WINDS IN PLACE TO BE IN THE 15
TO 25 KT RANGE TONIGHT...WITH WAVES FURTHER BUILDING ACROSS THE
SOUTHERN HALF OF THE LAKE. THIS INCLUDES THE NEARSHORE WATERS
WHERE WAVES OF 4 TO 7 FT ARE LIKELY TONIGHT INTO SUNDAY...AND SO
HAVE ISSUED AN SCA DURING THIS TIME. IT IS POSSIBLE THAT THE WAVES
MAY REMAIN ELEVATED BEYOND 15Z SUNDAY...AND THUS A POSSIBILITY FOR
SCA CONDITIONS TO PERSIST BEYOND THE CURRENT END TIME. WILL NEED
TO MONITOR FOR THIS POTENTIAL TONIGHT INTO SUNDAY.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 AM SUNDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
1141 PM CDT Sat Mar 22 2014
.DISCUSSION...
ISSUED 900 PM CDT Sat Mar 22 2014
Plenty of mid-level moisture will be streaming into IL from the
west overnight, keeping clouds over a majority of our forecast
area through morning. The only exception may be north of Peoria
where drier air may reduce the mid-clouds and leave just some
cirrus at times. The clouds will work to insulate the lower
levels and keep low temps from dropping down to guidance numbers.
Will be increasing lows a few degrees where thicker clouds will
be more prominent across at least the mid section of the area.
Sunshine should break through Sunday morning as dry air closer to
the center of the high filters in from the NW.
Radar returns this evening and overnight, associate with the cloud
layer, will not produce any precip. Virga will be the primary
result. Updates this evening were mainly to temp grids with minor
adjustments to clouds. Updated forecast info will be available
shortly.
Shimon
&&
.AVIATION...
ISSUED 1141 PM CDT Sat Mar 22 2014
VFR clouds at 10k to 12k FT will continue to stream across C IL
from the west in the fast jet stream flow. Surface winds will turn
more northerly as the surface high pressure builds into IL. That
northerly flow may drag some lake effect clouds toward our eastern
CWA after midnight. Those clouds should generally be around 2.5k
to 3.5k FT and arrive after 09z as depicted by the RAP and HRRR,
with some support from the NAM as well. That period of low clouds
could linger until mid to late morning on Sunday before dry air
closer to the center of the high finally dissipates the majority
of our cloud cover. The remainder of Sunday should be mostly clear
with just some cirrus Sunday afternoon and evening.
The surface pressure gradient and pressure rises will continue to
create NW winds in the 10-15kt range the rest of tonight and through
most of the day tomorrow. By sunset, winds should decouple as the
surface ridge axis pushes into IL.
Shimon
&&
.PREV DISCUSSION...
ISSUED 316 PM CDT Sat Mar 22 2014
Main concerns this forecast period will be the chance of snow for
early next week, Mon through Tue. Then the concern shifts to later
part of the week with a stronger system and chances of rain. Short
term models differ on strength of the first system with NAM/SREF
stronger than the GFS/ECMWF. Models look similar til Monday
morning, but then differ during the system, which is the most
critical time. This will have to be watched over the next couple
of model runs since this appears to be the first or second run
that the this has occurred. All models do have mid level wave and
pcpn moving across the area at the same time, just amount is
different.
Extended models agree on pattern shifting from northwest flow to
more zonal for later part of the week. So, there is some agreement
with the second system timing and resulting weather, which looks
to start little sooner and last little longer than previous
forecasts.
SHORT TERM...Tonight through Tuesday
Cold high pressure will continue over the area through Sunday
night and then the high will shift to the east, allowing a weather
system to move into the area for Monday afternoon through early
Tuesday morning. With the model differences/issues mentioned above
believe it best to keep pops in chance category, though in the
40-50 range, during the time of most of the pcpn. Models do agree
on timing of pcpn starting Monday afternoon in the western half of
the cwa, and then continuing through Mon night and then across the
eastern half of the cwa for Tuesday morning, and ending by
afternoon. Temps will be sufficiently cold in the atmosphere that
almost all the pcpn should be snow during the period. However,
there is a small chance that there could be a little bit more warm
air in the lower levels in the southeast, that some of the pcpn
could be a mix of rain and snow. However, because of the model
differences, am not going to mention that at this time and just
keep all pcpn in form of snow. Forecasted snowfall amounts will be
an inch or less over the northern part of the area through Tue
morning. South and southeastern areas will be less, given the
possible mix and the slightly warmer temperatures. If, however,
the stronger NAM does verify, then amounts will likely be more
than an inch. But keeping it on the lower side for now.
Temps will remain around 15 degrees below normal through the
period. MOS guidance looks ok.
LONG TERM...Tuesday night through Saturday
Cool high pressure then returns for a brief period Tue night
through Wed night, before the next weather system for rest of the
week. This next system appears to come in two waves, with warm air
advection pcpn coming Thursday and then the main system/front
coming Thur night into Friday. Pcpn type will be all liquid and
for now will just have showers. However, based on current model
runs, early indications are that there could be some thunder in
there as well. Will continue to monitor this in the days ahead.
Temps will finally warm back to around normal.
Auten
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
542 AM MDT SUN MAR 23 2014
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 350 AM MDT SUN MAR 23 2014
FORECAST CONCERN WILL BE WINDS MONDAY AND TEMPERATURES THROUGH
TUESDAY. SATELLITE CONTINUING TO SHOW AN AMPLIFIED/COMPLICATED FLOW
PATTERN OVER THE PACIFIC WHICH TRANSITIONS INTO A BROAD TROUGHINESS
AND PROGRESSIVE WESTERLY FLOW OVER THE COUNTRY. SEVERAL SHORTWAVE
TROUGHS EMBEDDED WITHIN THAT FLOW. MUCH DRIER AIR MASS ALOFT MOVING
INTO THE REGION WITH COLD AND MOIST AIR MASS ESTABLISHED AT THE
SURFACE.
MODELS INITIALIZED FINE AT JET AND MID LEVELS. ALTHOUGH THE MODELS
MAY NOT HAVE THE LOW OVER THE EASTERN PACIFIC FAR ENOUGH WEST.
OVERALL AT MID LEVELS THE SREF WAS THE WORST. THE NAM AND CANADIAN
WERE DOING BEST AT THE SURFACE. THE GFS FOLLOWED BY THE UKMET AND
CANADIAN WERE DOING THE BEST ON THE LOW LEVEL THERMAL FIELD.
TODAY/TONIGHT...SOME OF THE MESOSCALE MODEL OUTPUT IS INDICATING FOG
DEVELOPING/CONTINUE AT THE BEGINNING OF THIS PERIOD. ALSO THE
MESOSCALE GUIDANCE IS INDICATING THAT CLOUD COVER WILL BE SLOW TO
ERODE AND LEAVE IN MY WESTERN THIRD TO HALF WITH MY EASTERN AREAS
CLEARING OUT...WHICH IT HAS AND NOW TEMPERATURES ARE DROPPING OVER
THERE. WILL CONTINUE TO ASSESS AND MAKE ADJUSTMENTS AS NEEDED
THROUGH THE REST OF THE NIGHT BUT THIS DEFINITELY COULD HAVE AN
AFFECT ON HOW WARM IT GETS TODAY. LATER GUIDANCE HAS TRENDED
COLDER FROM THE EARLIER 00Z GUIDANCE. SO MADE ADJUSTMENTS IN THAT
DIRECTION. GRADIENT AND 3 HOUR PRESSURE FALLS INDICATE AT LEAST
BREEZY CONDITIONS...ESPECIALLY IN THE WEST...AND ADJUSTED THE WINDS
ACCORDINGLY.
WEAK RIGHT REAR QUADRANT COMES ACROSS DURING THE NIGHT...MAINLY OVER
THE NORTHERN PORTION. BY THE END OF THE NIGHT A STRONG NORTH TO SOUTH
JET IS DIVING DOWN THE BACKSIDE OF THE TROUGH MOVING THROUGH. THE
LEFT FRONT QUADRANT OF THIS JET LOOKS TO BE WEST OF THE AREA BY THE
END OF THE NIGHT. LOWER LEVELS OF THE AIR MASS ARE TOO DRY FOR
PRECIPITATION AND WILL KEEP THE FORECAST DRY. HOWEVER...WOULD NOT
BE A FEW SNOWFLAKES WOULD FALL IN THE NORTHEAST PORTION OF THE AREA.
FRONT LOOKS LIKE IT MOVES THROUGH LATE IN THE NIGHT. MODELS ARE
SHOWING A LITTLE MORE STRATUS COMING THROUGH BEHIND IT.
MONDAY/MONDAY NIGHT...GRADIENT AND 3 HOUR PRESSURE RISES WOULD
INDICATE THAT THE WINDS BEHIND THE COLD FRONT WILL REMAIN BELOW
WIND ADVISORY CRITERIA BUT COULD DEFINITELY GET WINDY. LEFT FRONT
QUADRANT OF THE ABOVE MENTIONED JET MOVES ACROSS DURING THE MIDDLE OF
THE DAY WITH THE JET TO THE NORTHEAST OF THE AREA BY THE END OF THE
DAY. AT THE VERY LEAST THIS COULD KEEP SOME CLOUDS...AND POSSIBLY A
FEW FLURRIES...AROUND TO POSSIBLY AFFECT TEMPERATURES. MODEL
GUIDANCE ALSO CAME A LITTLE COOLER AND THAT MAKES SENSE. SO DID
ADJUST DOWN SLIGHTLY.
INTERESTING FORECAST FOR THE NIGHT. MODELS SHOW A SECONDARY
PRESSURE/COOL SURGE THAT COMES IN LATER IN THE NIGHT. MODELS SHIFT
THE WINDS TO A LIGHT UPSLOPE DIRECTION. INITIALLY THOUGHT THAT THE
LIGHTER WINDS WOULD ALLOW FOR COOLER TEMPERATURES. HOWEVER...MODELS
ARE ALSO BRINGING IN A LOT MORE LOW LEVEL CLOUD COVER...ESPECIALLY IN
THE EASTERN HALF TO TWO THIRDS. SO MADE ADJUSTMENTS BASED ON THIS.
IF CLOUD COVER DOES NOT MATERIALIZE THEN IT WILL BE MUCH COLDER.
TUESDAY/TUESDAY NIGHT...DAY STARTS OUT WITH LIGHTER/EASTERLY WINDS.
BY THE MIDDLE OF THE DAY THE GRADIENT TIGHTENS AS 3 HOUR PRESSURE
FALLS START INCREASING. EARLY INDICATIONS ARE THAT IT SHOULD ONCE
AGAIN SHOULD BE AT LEAST BREEZY...ESPECIALLY IN THE WEST. MODELS ARE
ALSO INDICATING THAT MORE STRATUS WILL BE AROUND AND CONSIDERING
THE EAST TO SOUTHEAST WINDS THAT ALSO MAKES SENSE. AT THIS TIME IT
LOOKS LIKE IT SHOULD CLEAR OUT BY 18Z. HOWEVER...IF THAT IS NOT THE
CASE...MAXES WILL BE ADVERSELY AFFECTED. AT THIS TIME WENT TOWARD
THE COOLER GUIDANCE AND MADE SLIGHT ADJUSTMENTS TO THE ONGOING
FORECAST.
IT COULD END UP BEING A VERY MILD NIGHT. LOW LEVEL JET AND WARM AIR
ADVECTION REALLY KICKS IN DURING THE NIGHT. SO BASED ON THIS MADE
ADJUSTMENTS TO THE ONGOING FORECAST.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 350 AM MDT SUN MAR 23 2014
SEVERAL UPPER LEVEL SHORT WAVE TROUGHS WILL MOVE THROUGH THE AREA
WEDNESDAY THROUGH SATURDAY...THE STRONGEST OF THEM WILL BE ON
THURSDAY.
WEDNESDAY AN UPPER LEVEL RIDGE WILL BUILD OVER THE AREA...WITH A
SUBTLE SHORT WAVE TROUGH MOVING THROUGH THE FLOW AROUND THE RIDGE.
MODELS CONTINUE TO KEEP THE SHORT WAVE TO THE SOUTH...KEEPING DRY
CONDITIONS OVER THE AREA. TEMPERATURES WILL BE ALMOST 20 DEGREES
ABOVE NORMAL BEHIND THE WARM FRONT. WITH WINDS GUSTING 25-30 MPH
AND RELATIVE HUMIDITIES FALLING TO LESS THAN 20 PERCENT FOR THE
WESTERN TWO COLUMNS OF COUNTIES...HAZARDOUS FIRE WEATHER CONDITIONS
ARE POSSIBLE IN THE AFTERNOON.
LATE WEDNESDAY NIGHT SOME SMALL PRECIP. CHANCES BEGIN TO MOVE INTO
THE AREA AS THE LEFT EXIT OF THE 500 MB JET STREAM ACCOMPANYING THE
NEXT TROUGH MOVES INTO THE AREA.
THURSDAY THE SHORT WAVE TROUGH MOVES THROUGH THE AREA. MODELS
INDICATE A DRY ENVIRONMENT AHEAD OF THE SHORT WAVE TROUGH...WITH THE
ENVIRONMENT SATURATING JUST AHEAD OF THE TROUGH AXIS. AM THINKING
THERE WILL BE A QUICK SHOT FOR PRECIP. TO DEVELOP OVER THE AREA
BEFORE SUBSIDENCE MOVES IN BEHIND THE TROUGH AXIS DUE TO THE
SATURATED ENVIRONMENT BEING JUST AHEAD OF THE TROUGH AXIS.
MEANWHILE A STRONG COLD FRONT WILL ALSO MOVE THROUGH CAUSING
TEMPERATURES TO FALL BELOW NORMAL BEHIND IT ALONG WITH PRODUCING
GUSTY NORTHERLY WINDS.
THURSDAY NIGHT SOME SMALL PRECIP. CHANCES WILL RETURN TO THE
SOUTHWEST PART OF THE AREA AS A SUBTLE SHORT WAVE TROUGH MOVES IN
BEHIND THE STRONGER ONE FROM EARLIER IN THE DAY.
FRIDAY/FRIDAY NIGHT TWO SUBTLE SHORT WAVE TROUGHS MOVE OVER THE
AREA. THERE APPEARS TO BE SOME MOISTURE FOR THE TROUGHS TO WORK
WITH...SO LOW PRECIP. CHANCES SEEM REASONABLE.
SATURDAY AN UPPER LEVEL RIDGE BUILDS OVER THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 535 AM MDT SUN MAR 23 2014
LINGERING LOW LEVEL MOISTURE BEHIND EXITING STORM SYSTEM IS MAKING
FOR A TRICKY TAF FORECAST. MAJORITY OF THE MODEL OUTPUT IS NOT
CATCHING THE STRATUS FIELD VERY WELL. THE LATEST HRRR AND RUC ARE
DOING THE BEST JOB AND WILL BE USING THESE ALONG WITH PERSISTENCE
FOR THESE TAFS. AT KGLD...IFR/CLOSE TO LIFR CONDITIONS WILL BECOME
MVFR BY LATE MORNING BEFORE THE CEILINGS SCATTER OUT. HOWEVER...AM
A LITTLE NERVOUS THAT THIS MAY BE A LITTLE SOON. ONCE THE CLOUDS
CLEAR GUSTY SOUTHERLY WINDS WILL BEGIN AND CONTINUE UNTIL EARLY
THIS EVENING.
ANOTHER COLD FRONT WILL MOVE THROUGH THE AREA AFTER 06Z. MODELS
ARE INDICATING ANOTHER BATCH STRATUS COMING IN WITH THE FRONT AND
CONSIDERING WHAT IS GOING ON THIS MORNING AM INCLINED TO BELIEVE
IT BUT NOT TOTALLY. WILL INTRODUCE A SCT DECK AT KGLD. FOR KMCK...
MVFR CEILINGS ARE EXPECTED THROUGH THE MORNING WITH THE SAME
CAVEAT AS FOR KGLDS FORECAST. GUSTY WINDS WILL ALSO FOLLOW THE
SAME PATTERN. FOR THE FRONTAL PASSAGE LATER TONIGHT AT KMCK AM
DOING THE SAME THING AS FOR KGLDS TAF. ALTHOUGH IT WILL BE
POSSIBLE AT BOTH SITES THAT A MVFR CEILING COULD OCCUR.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JTL
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS PADUCAH KY
919 PM CDT Mon Mar 24 2014
.UPDATE...
Issued at 919 PM CDT MON MAR 24 2014
Followed the HRRR and RUC13 and 18Z NAM, along with observational
trends for general PoP trends through Tuesday morning. A narrow
east-west oriented band of light snow extending from Farmington
Missouri to Evansville Indiana will gradually dry up from west to
east late this evening, as it drifts slowly southward.
Temperatures will drop close to freezing once this snow sets in,
so some minor accumulations will be possible in this area late
this evening. Other light precipitation may dive southeast through
western portions of southeast Missouri and possibly into the
Purchase Area of west Kentucky through the late evening. This
should mainly be rain, and temperatures will likely hold in the
middle 30s.
There should be a break for a few hours after midnight, before
another impulse rotates through the area with a band of light snow
or snow showers. More minor accumulations will be possible over
southern Illinois generally north of Highway 13, southwest
Indiana and northwest Kentucky. This will likely straddle sunrise
and may be ongoing during the morning commute over the Evansville
Tri State. Will have to monitor for slick conditions in the
morning...but confidence is low to think about an Advisory at this
time. All totalled, grassy accumulations will generally be a half
inch or less, with the greatest amounts over southwest Indiana.
The RUC has a real good handle on surface temperatures, as they
drop to near freezing once the precipitation develops in a given
area. Used it as a guide for trends through the night, but
ultimately, low temperatures were not impacted much by morning.
&&
.SHORT TERM...(Tonight through Wednesday)
Issued at 247 PM CDT MON MAR 24 2014
Main challenge this package is the threat for rain/snow mainly
tonight over the northern half.
Water vapor and radar indicate a weak system in the flow currently
over Kansas. All models continue to weaken the system as it moves
closer to us. We are very dry in the low levels so it may take a
while for the precipitation to reach the ground. It should
saturate over the north central areas by early evening. May be a
mix of rain/snow initially, but the column will be cold enough to
generate some snow for a few hours overnight.
Ground is warm and it does not look like we will exceed 1 inch per
hour rates, so feel that any accumulations will be confined to grassy
surfaces. Total QPF is less than a tenth of an inch and snowfall
is expected to be less than 1/2 inch.
This system will exit the area tomorrow morning, maybe with a few
lingering flurries in the northeast in the morning. After that,
high pressure will move into the area and we will remain dry
through Wednesday.
Will strongly word fire weather forecast for tomorrow as winds
will be strong and afternoon RH values will range from 30-40
percent.
Tuesday night will be coldest night of the week with lows in the
teens near I-64 and mid 20s in the south.
.LONG TERM...(Thursday through Monday)
Issued at 247 PM CDT MON MAR 24 2014
The med range models/ensembles seem in decent agreement with the
over synoptic pattern through Friday. Thereafter...12Z GFS diverges
from the operational ECMWF/GEM runs with respect to sfc low/precip
generation over the OH Valley. The GFS seems like an outlier here,
so will not give it too much weight at this time.
As far as the sensible weather is concerned, though shower chcs will
begin to slowly increase late Wed night in prefrontal warming
environment, the highest chc for showers and even some elevated
thunderstorms will come with the frontal passage Thu night. Some
locations may end up with a half inch or more. Decided to go with
a mainly rain free forecast once the front exits the area Friday
as high pressure presses southeast into the Midwest. Again, will
discount the 12Z GFS for now in the Fri/Fri night time frame. Will
also stick closer to the cooler EC MOS numbers Friday. Confidence
increases once again as we move into the weekend. There seems to
be very good model agreement that a dry and warming pattern should
get underway in the last few days of the extended period.
&&
.AVIATION...
Issued at 612 PM CDT MON MAR 24 2014
Fairly rapid moving weather system will move east-southeast across
the WFO PAH TAF sites overnight. With the exception of KCGI
briefly this evening, forecast ceiling heights should remain VFR,
even with a mention of light snow at KCGI, KEVV, and KOWB overnight.
Visibilities should stay at or above six (6) statute miles regardless
of the snow coverage. VFR ceilings should remain for most of the
second half of the forecast period.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...PS
LONG TERM...GM
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1158 PM CDT Sat Mar 22 2014
.UPDATE...
Issued at 1130 PM CDT SAT MAR 22 2014
Updated aviation section for 06z TAF package.
UPDATE Issued at 949 PM CDT SAT MAR 22 2014
Forecast looking pretty good late this evening. The 00Z NAM and
latest HRRR keep any tangible precipitation just south of our
border, but latest radar trends do show some light echoes into
southeast Missouri. Not sure if those echoes are reaching the
ground or not...but the KPOF ASOS is not registering any
precipitation. Figure a few sprinkles at best out of the echoes
currently over southeast Missouri. The bottom line is that the
hourly PoP trends were left alone overnight. The 50-60% PoPs right
along the border may be too high, but the gradient will be sharp
on the north end of the precipitation shield.
Used the consensus of short term guidance to increase north winds
through the night, and also bring temperatures and dew points down
a bit over much of the area. The exception is over west Kentucky,
where temperatures will be slower to fall than expected. This may
be just enough to keep snow from reaching the ground, if there is
any tangible precipitation overnight. Wind chills will be in the
20s over most areas by daybreak Sunday.
&&
.SHORT TERM...(Tonight through Tuesday)
Issued at 226 PM CDT SAT MAR 22 2014
Skies have cleared as high pressure continues to build south
across the area. Next system of interest taking shape over the
southern Plains. This feature will move east tonight and may
spread light rains into the SRN 1/4 of the area overnight. Will
continue with this chance, with generally dry conditions north of
the Ohio. Models continue to vary with the northward extent, which
lends to lower confidence given we are this close to onset.
Adjustments can be made during the evening shift. Before the light
precip moves out, will carry 3 hrs or so of a light rain, light
snow mix possibility. It will not amount to anything.
Dry weather returns Sunday through Monday in the wake of the weak
mid level system, and with high pressure still making its presence
felt. The system that will affect the area Monday night is a bit
more dynamic. Will continue with our low chance PoPs area wide
Monday night and in the far east Tuesday. Will also continue with
the mix (chance of rain and snow) type wording. Not a high
confidence call here either as moisture is somewhat limited.
.LONG TERM...(Tuesday night through Saturday)
Issued at 226 PM CDT SAT MAR 22 2014
High pressure will settle into the region Tuesday night...but
quickly move east during the morning/afternoon hours on Wednesday. A
nice gradient will set up over the region Wednesday night into
Thursday as a sfc low pressure system gets developed over the
Rockies. More about that later.
First off, an upper level system over northern Mexico, will
move into Texas on Wednesday afternoon. Models differ on what to do
with this feature beyond that though. The 00Z ECMWF weakens the
trough and actually takes it northwest of the region and the 12Z run
looks more like the GFS. The GFS takes it right across our region and
brings precipitation into the area as early as Wednesday night into
Thursday. Could see a stray rain shower sneak into the area by late
Wednesday night in SEMO, but think that any precip associated with
this system should be on Thursday, and be confined to the northwest
half of the area.
Meanwhile, another shortwave trough will be moving east out of the
Rockies in conjunction with the aforementioned sfc low. The low
moves into Kansas by 18Z Thursday. Differences arise with the
speed/progression of this sfc low/front...but these differences have
gotten smaller with the 12Z runs. The GFS brings the front into the
area on Friday, exiting the area Friday evening. The 00Z ECMWF was
much fast due to a strong upper level trough, and brought the front
into the area Thursday evening, exiting on Friday morning. But the
12Z shows a very similar solution to the GFS. Therefore, confidence
is higher that rain will be a good bet at least on Thursday
night/early Friday. Inserted some isolated thunderstorm as there
seems to be enough elevated instability to support it.
Pops for Friday and Saturday will be more challenging due to timing
issues with the models. Previous runs of the GFS/ECMWF indicated
high pressure building in for Friday night into Saturday providing
dry weather. However, the new 12Z ECMWF arrived with an entirely
different solution to what it had in its 00Z run, with continued
chances for precipitation until another trough pushes the front east
of the area. Will leave Friday night through Saturday night dry at
this time until better consistency arrives.
As far as temperatures, we should see a substantial rise in temps on
Wednesday as winds become southerly on the back side of the sfc
high. However, Tuesday night will be a cold one, as calm/clear
conditions provide excellent radiational cooling. Temperatures look
to get well down into the 20s Tuesday night. Therefore, even with a
stronger March sun, we may not be able to crack 50 degrees on
Wednesday despite decent warming aloft, except for maybe in SEMO. We
should reach well into the 50s on Thursday though. Highs on Friday
will be tricky due to the differences in frontal position. However,
it does not look like we will see any major cold air intrusions in
the wake of this front.
&&
.AVIATION...
Issued at 1158 PM CDT SAT MAR 22 2014
Bkn-ovc mid clouds will move across TAF sites overnight. A few
sprinkles are possible at KCGI/KPAH through 14z, but chances are
not enough to include in TAF and will not restrict vsbys. Winds
will continue from the north at 8 to 14 kts, finally decreasing to
4 to 9 kts after 22z. Mid clouds will move between 13z-17z.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AVIATION...RST
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
635 PM EDT SUN MAR 23 2014
.SYNOPSIS...
LOW PRESSURE MOVES OFF THE NORTH CAROLINA COAST TONIGHT...WITH HIGH
PRESSURE BUILDING IN FROM THE NORTHWEST MONDAY. LOW PRESSURE
TRACKS ACROSS THE SOUTHEASTERN STATES MONDAY NIGHT THEN OFF THE
MID ATLANTIC COAST TUESDAY. HIGH PRESSURE RETURNS WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
PCPN (RAIN/SLEET/WET SNOW MIX) QUICKLY SKEDADDLING TOWARDS THE
COAST WITH SAT LOOP INDCTG CLOUDS QUICKLY BREAKING UP WITH ONLY
SCT-BKN AC ACROSS WRN MOST COUNTYS ERLY THIS EVENING. WILL ADJUST
GRIDS TO ACCOUNT FOR THESE QUICKER TRENDS NEXT FEW HOURS WITH SKIES
EXPECTED TO BECOME M CLR TO PT CLOUDY BY MIDNITE AS STRONG CANADIAN
HIGH PRESSURE (+1 STD DEV MSLP) BUILDS OVER THE GREAT LAKES REGION.
A STRONG SECONDARY SURGE OF COLD/DRY AIR IS ALSO EXPECTED ACROSS
OUR REGION OVERNIGHT. COLD AS TEMPS DROP INTO THE M20S-L30S (~10
DEGS BELOW NORMAL).
MODIFYING COLD/DRY HIGH PRESSURE BUILDS FROM THE OH VALLEY ACROSS
THE MID-ATLANTIC MONDAY, WITH WELL BELOW NORMAL TEMPS EXPECTED.
WHILE H85 TEMPS -2 STD DEV...LATE MARCH SUN WILL HELP WARM TEMPS
INTO THE MID 40S INLAND (~15 DEGS BELOW NORMAL). N-NE WINDS 10-15
MPH WILL RESULT IN AN ESPECIALLY BREEZY AND BRISK DAY OVER COASTAL
AREAS...WITH TEMPS ONLY WARMING INTO THE MID-UPPER 30S THANKS TO
COLD WATERS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
MONDAY NIGHT...CLEAR BRIEFLY MONDAY NIGHT AS HIGH PRESSURE PUSHES
OFFSHORE. WIND VEER AROUND TO THE S-SE AND CLOUDS INCREASE IN
ADVANCE OF THE NEXT SYSTEM. LOWS GENERALLY IN THE UPPER 20S-LOW
30S.
STRONG COASTAL LOW PRESSURE SYSTEM WILL BEGIN TO TAKE SHAPE MON
NIGHT AS A QUICK MOVING SHORTWAVE EMERGING FROM THE NORTHERN
PLAINS INTO THE OHIO VALLEY SHARPENS A LONGWAVE TROUGH OVER THE
ERN CONUS TUESDAY (-2 STD DEV 500MB HEIGHTS)...RESULTING IN
CYCLOGENESIS OFF THE SE COAST. STRONG HEIGHT FALLS AND A STRONG PV
ANOMALY WILL RESULT IN RAPID INTENSIFICATION OF THIS SFC LOW AS
IT LIFTS RAPIDLY NEWD ALONG THE SE AND MID-ATLANTIC COAST THROUGH
TUESDAY NIGHT. OVERALL...MODELS REMAIN IN DECENT AGREEMENT WITH
HANDLING THE HIGHLY AMPLIFIED UPPER PATTERN AND GENERAL SFC LOW
TRACK AND STRENGTH AS THE LOW LIFTS OFF THE SE COAST AND PUSHES
WELL OFF THE MID-ATLANTIC COAST TUESDAY AFTN/NIGHT. HOWEVER, SOME
SPATIAL AND TIMING DIFFERENCES CONTINUE WHICH COULD HAVE
MEANINGFUL DIFFERENCES WRT SENSIBLE WEATHER FOR THE LOCAL AREA.
HAVE SIDED CLOSER TO ECMWF BLENDED SOLUTION WITH THIS PACKAGE.
EXPECT TWO DISTINCT AREAS OF PCPN WITH THIS SYSTEM. INLAND, EXPECT
SOME MOISTURE TO PUSH NE ACROSS PIEDMONT/METRO REGION TUESDAY
MORNING AS UPPER SYSTEM INTENSIFIES AND BEGINS TO TAKE ON NEG TILT.
THIS MOISTURE WILL BE QUICK TO DEPART TUESDAY AFTN AS LOW-MIDLVL
CYCLOGENESIS OCCURS RAPIDLY TO OUR NORTHEAST TUESDAY NIGHT. THE
SECOND AREA IS WITH SECOND AREA OF ATLANTIC MOISTURE ADVECTED
NORTH ACROSS THE COASTAL PLAIN TUESDAY AFTN EVENING. THIS MOISTURE
WILL LIFT NORTH ACROSS EASTERN SECTIONS TUESDAY AFTN/EVENING
BEFORE PUSHING OFFSHORE BY LATE TUE NGT. THERMAL PROFILES CONTINUE
TO SUGGEST THAT LIGHT SNOW WILL BE POSSIBLE...AND IN FACT LIKELY
ACROSS THE PIEDMONT (METRO RIC)...WITH UPPER TROUGH. EXPECTATION
REMAINS THAT WITH ONSET OF PCPN COMING AT OR JUST AFTER
SUNRISE...LGT PCPN RATES, MARCH SUN AND MARGINAL BL TEMPS WOULD BE
ENOUGH TO PRECLUDE ANY MAJOR IMPACTS OR ACCUMULATION ISSUES.
FARTHER SOUTH, EXPECT A BRIEF PERIOD OF SNOW/SLEET/RN RIGHT AROUND
SUNRISE ALONG AND SOUTH OF THE HIGHWAY 58 CORRIDOR IN SOUTH
CENTRAL VA, TRANSITIONING TO ALL RAIN QUICKLY THEREAFTER...WITH
LGT RAIN FOR ALL BUT FAR NORTHWEST IN BY LATE MORNING. CUT BACK TO
SHOWERS GRADUALLY FROM WEST TO EAST AS MOISTURE RACES OFF TO THE
NE, BUT DID HOLD ONTO CHANCE POPS ALONG THE COAST TUESDAY NIGHT TO
ACCOUNT FOR POTENTIAL WRAP AROUND PRECIP INTO THE NE LOCAL AREA.
STRONG SURGE OF COLD/DRY AIR EXPECTED TUE NIGHT AS STRONG HIGH
PRESSURE BUILDS IN FROM THE WEST. CLEARING, WINDY AND COLD TUES
NIGHT WITH LOWS IN THE 20S TO NEAR 30.
HIGH PRESSURE BUILDS IN FROM THE WEST ON WED...WITH A CHILLY,
DRYING W-NW WIND PREVENTING TEMPS FROM GETTING TOO FAR DESPITE
A FAIR AMOUNT OF INSOLATION. LOOK FOR HIGHS ONLY INTO THE MID-UPR
40S INLAND, WITH LOW/MID 40S OVER COASTAL ZONES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE OVER THE AREA WEDNESDAY NIGHT WILL GRADUALLY MOVE
THROUGH THURSDAY...PROVIDING DRY WX INTO THURSDAY NIGHT. THE NEXT
CHANCE OF PCPN COMES FRIDAY/SATURDAY...THEN THINGS DRY OUT AGAIN BY
NEXT SUNDAY. P-TYPE WILL NOT BE AN ISSUE DUE TO THE MILDER PATTERN.
MILDER THURSDAY WITH HIGHS IN THE 50S. SEASONABLE FRIDAY/SATURDAY
WITH HIGHS IN THE 60S. COLD WEDNESDAY NIGHT WITH LOWS 25-30...THEN
WARMING INTO THE 40S TO LOW 50S BY THE WEEKEND.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
MOST TAF SITES WILL START OUT WITH VFR CONDITIONS AT 18Z WITH
THE EXCEPTION OF RIC WHERE CEILINGS WILL FALL TO 3KFT OR LESS
SHORTLY AFTER 18Z WITH LIGHT RAIN. MVFR CEILINGS SHOULD SPREAD
EAST TO ALL OTHER SITES BETWEEN 19Z AND 20Z. MVFR CIGS ARE LIKELY
AT ALL SITES THROUGH THE AFTERNOON AS THE AREA OF LIGHT PRECIP
PUSHES THROUGH. HRRR MODEL SUGGESTS THE PRECIP WILL TAPER OFF AT
RIC AROUND 22Z...THEN EXIT THE COAST AROUND 00Z. THERE MAY BE
ANOTHER BRIEF CHANCE OF LIGHT RAIN WITH THE NEXT FRONT/SURGE LATE
THIS EVENING AND TONIGHT...BUT CONDITIONS SHOULD REMAIN MOSTLY VFR
WITH JUST A BRIEF PERIOD OF MVFR VSBY POSSIBLE WITH THE LIGHT
RAIN. IN GENERAL WIDESPREAD MVFR CONDITIONS SHOULD IMPROVE AFTER
00Z. NE WINDS WILL AVG 10-15 KT AT KORF/ECG THROUGH THE AFTERNOON
AND EVENING...GENLY 10 KT ELSEWHERE.
IMPROVING CONDITIONS AFTER 04-06Z TONIGHT AS N/NW WINDS BRING DRIER
AIR BACK TO THE AREA. MIXED PCPN WITH PERIODS OF IFR ARE INDICATED
FOR TUESDAY AND TUESDAY EVENING...AS ANOTHER SYSTEM MOVES ACROSS
THE REGION. THIS SYSTEM INTENSIFIES RAPIDLY OFF THE MID ATLANTIC
COAST TUESDAY NIGHT/WEDNESDAY...WITH LINGERING CHC FOR SNOW TUE
EVENING FOLLOWED BY STRONG NW WINDS AT ALL SITES LATER TUE NIGHT
INTO MIDDAY WED.
&&
.MARINE...
WINDS WILL CONTINUE TO DIMINISH OVER THE BAY AND NORTHERN COASTAL
ZONES LATE THIS AFTERNOON INTO THIS EVENING...AS A BRIEF LULL
BETWEEN TWO SURGES OF COLD AIR TAKES PLACE. THIS WILL NOT AFFECT THE
SCA`S THAT ARE CURRENTLY IN EFFECT AS THIS LULL IN WINDS IS EXPECTED
TO BE SHORT IN DURATION. THE 2ND SURGE LATER TONIGHT WILL BE THE
STRONGER OF THE TWO. IMPRESSIVE COLD AIR FOR LATE MARCH WILL ALLOW
FOR OPTIMAL MIXING AND SHOULD HAVE SOLID SCA CONDITIONS ALL ZONES
OVERNIGHT INTO MON MORNING WITH N/NW WINDS AVERAGING 20-25 KT WITH
GUSTS TO 30 KT.
HIGH PRESSURE BRIEFLY BUILDS INTO THE REGION MON AFTN...ALLOWING THE
GRADIENT TO ONCE AGAIN WEAKEN AND SUB-SCA CONDITIONS TO TAKE OVER. A
STRONG LOW PRESSURE SYSTEM IS FORECAST TO DEVELOP OFF THE SE COAST
TUE MORNING...AND RAPIDLY INTENSIFY LATE TUESDAY/WEDNESDAY. SOME
DIFFERENCES REMAIN AMONGST THE MODEL GUIDANCE...BUT THERE IS ENOUGH
AGREEMENT THAT CONFIDENCE FOR GALES IS INCREASING FOR TUE NIGHT/WED
AS VERY STRONG PRESSURE FALLS ARE EXPECTED WITH THIS SYSTEM. HAVE
GUSTS TO AROUND 40 KT FOR COASTAL WATERS AND 35-40 KT ELSEWHERE IN
THE GRIDDED FORECAST FOR NOW. IF THE SYSTEM WERE TO SLOW ITS
MOVEMENT NORTH...COULD EVEN SEE SOME STORM FORCE GUSTS ALONG THE
COASTAL WATERS WED. BECAUSE THE ONSET OF GALE FORCE CONDITIONS WOULD
NOT BE UNTIL TUESDAY NIGHT (5TH PERIOD)...WILL NOT GO WITH A GALE
WATCH ATTM. WAVES ON THE BAY ARE FORECAST TO REACH 4-5 FT TUES
NIGHT...WITH SEAS BUILDING TO 5-8 FT ON THE OCEAN.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT MONDAY FOR ANZ630>632-
634>638-650-652.
SMALL CRAFT ADVISORY UNTIL 1 PM EDT MONDAY FOR ANZ633.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT MONDAY FOR ANZ654-656-658.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MPR/MAM
SHORT TERM...MAM/SAM
LONG TERM...JDM
AVIATION...JAO
MARINE...JDM/LKB
AREA FORECAST DISCUSSION...CORRECTED
NWS WAKEFIELD VA
414 PM EDT SUN MAR 23 2014
.SYNOPSIS...
LOW PRESSURE MOVES OFF THE NORTH CAROLINA COAST TONIGHT...WITH HIGH
PRESSURE BUILDING IN FROM THE NORTHWEST MONDAY. LOW PRESSURE
TRACKS ACROSS THE SOUTHEASTERN STATES MONDAY NIGHT THEN OFF THE
MID ATLANTIC COAST TUESDAY. HIGH PRESSURE RETURNS WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
WHAT A DIFFERENCE A DAY MAKES...MID-AFTN RADAR MOSAIC SHOWING PCPN
PROPAGATING E-NE ACROSS THE CWA AS EXPECTED, WITH TEMPS FALLING
THROUGH THE 40S LATE THIS AFTN. HAVE ALSO HAD A FEW REPORTS OF
SOME WET SNOWFLAKES/ICE PELLETS MIXING IN AS PCPN ENDS ACROSS FAR
NW COUNTIES. WEAK PCPN RATE/WARM BL WILL PREVENT ANY OPERATIONAL
ISSUES, BUT IT CERTAINLY UNDERSCORES THE COLDER AIRMASS HEADED
OUR WAY THROUGH THE SHORT TERM PERIOD. CHC POPS WEST/CATEGORICAL
OUT EAST SLOWLY RAMP DOWN THROUGH EARLY EVENING AS SLUG OF
OVERRUNNING MOISTURE PUSHES OFFSHORE AHEAD OF HIGH PRESSURE TO THE
WEST. QUICK CLEARING TONIGHT/OVERNIGHT AS STRONG CANADIAN HIGH
PRESSURE (+1 STD DEV MSLP) BUILDS OVER THE GREAT LAKES TONIGHT. A
STRONG SECONDARY SURGE OF COLD/DRY AIR IS ALSO EXPECTED ACROSS
OUR REGION OVERNIGHT, WITH TEMPS FALLING INTO THE MID 20S- LOW 30S
(~10 DEGS BELOW NORMAL).
MODIFYING COLD/DRY HIGH PRESSURE BUILDS FROM THE OH VALLEY ACROSS
THE MID-ATLANTIC MONDAY, WITH WELL BELOW NORMAL TEMPS EXPECTED.
WHILE H85 TEMPS -2 STD DEV...LATE MARCH SUN WILL HELP WARM TEMPS
INTO THE MID 40S INLAND (~15 DEGS BELOW NORMAL). N-NE WINDS 10-15
MPH WILL RESULT IN AN ESPECIALLY BREEZY AND BRISK DAY OVER COASTAL
AREAS...WITH TEMPS ONLY WARMING INTO THE MID-UPPER 30S THANKS TO
COLD WATERS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
MONDAY NIGHT...CLEAR BRIEFLY MONDAY NIGHT AS HIGH PRESSURE PUSHES
OFFSHORE. WIND VEER AROUND TO THE S-SE AND CLOUDS INCREASE IN
ADVANCE OF THE NEXT SYSTEM. LOWS GENERALLY IN THE UPPER 20S-LOW
30S.
STRONG COASTAL LOW PRESSURE SYSTEM WILL BEGIN TO TAKE SHAPE MON
NIGHT AS A QUICK MOVING SHORTWAVE EMERGING FROM THE NORTHERN
PLAINS INTO THE OHIO VALLEY SHARPENS A LONGWAVE TROUGH OVER THE
ERN CONUS TUESDAY (-2 STD DEV 500MB HEIGHTS)...RESULTING IN
CYCLOGENESIS OFF THE SE COAST. STRONG HEIGHT FALLS AND A STRONG PV
ANOMALY WILL RESULT IN RAPID INTENSIFICATION OF THIS SFC LOW AS
IT LIFTS RAPIDLY NEWD ALONG THE SE AND MID-ATLANTIC COAST THROUGH
TUESDAY NIGHT. OVERALL...MODELS REMAIN IN DECENT AGREEMENT WITH
HANDLING THE HIGHLY AMPLIFIED UPPER PATTERN AND GENERAL SFC LOW
TRACK AND STRENGTH AS THE LOW LIFTS OFF THE SE COAST AND PUSHES
WELL OFF THE MID-ATLANTIC COAST TUESDAY AFTN/NIGHT. HOWEVER, SOME
SPATIAL AND TIMING DIFFERENCES CONTINUE WHICH COULD HAVE
MEANINGFUL DIFFERENCES WRT SENSIBLE WEATHER FOR THE LOCAL AREA.
HAVE SIDED CLOSER TO ECMWF BLENDED SOLUTION WITH THIS PACKAGE.
EXPECT TWO DISTINCT AREAS OF PCPN WITH THIS SYSTEM. INLAND, EXPECT
SOME MOISTURE TO PUSH NE ACROSS PIEDMONT/METRO REGION TUESDAY
MORNING AS UPPER SYSTEM INTENSIFIES AND BEGINS TO TAKE ON NEG TILT.
THIS MOISTURE WILL BE QUICK TO DEPART TUESDAY AFTN AS LOW-MIDLVL
CYCLOGENESIS OCCURS RAPIDLY TO OUR NORTHEAST TUESDAY NIGHT. THE
SECOND AREA IS WITH SECOND AREA OF ATLANTIC MOISTURE ADVECTED
NORTH ACROSS THE COASTAL PLAIN TUESDAY AFTN EVENING. THIS MOISTURE
WILL LIFT NORTH ACROSS EASTERN SECTIONS TUESDAY AFTN/EVENING
BEFORE PUSHING OFFSHORE BY LATE TUE NGT. THERMAL PROFILES CONTINUE
TO SUGGEST THAT LIGHT SNOW WILL BE POSSIBLE...AND IN FACT LIKELY
ACROSS THE PIEDMONT (METRO RIC)...WITH UPPER TROUGH. EXPECTATION
REMAINS THAT WITH ONSET OF PCPN COMING AT OR JUST AFTER
SUNRISE...LGT PCPN RATES, MARCH SUN AND MARGINAL BL TEMPS WOULD BE
ENOUGH TO PRECLUDE ANY MAJOR IMPACTS OR ACCUMULATION ISSUES.
FARTHER SOUTH, EXPECT A BRIEF PERIOD OF SNOW/SLEET/RN RIGHT AROUND
SUNRISE ALONG AND SOUTH OF THE HIGHWAY 58 CORRIDOR IN SOUTH
CENTRAL VA, TRANSITIONING TO ALL RAIN QUICKLY THEREAFTER...WITH
LGT RAIN FOR ALL BUT FAR NORTHWEST IN BY LATE MORNING. CUT BACK TO
SHOWERS GRADUALLY FROM WEST TO EAST AS MOISTURE RACES OFF TO THE
NE, BUT DID HOLD ONTO CHANCE POPS ALONG THE COAST TUESDAY NIGHT TO
ACCOUNT FOR POTENTIAL WRAP AROUND PRECIP INTO THE NE LOCAL AREA.
STRONG SURGE OF COLD/DRY AIR EXPECTED TUE NIGHT AS STRONG HIGH
PRESSURE BUILDS IN FROM THE WEST. CLEARING, WINDY AND COLD TUES
NIGHT WITH LOWS IN THE 20S TO NEAR 30.
HIGH PRESSURE BUILDS IN FROM THE WEST ON WED...WITH A CHILLY,
DRYING W-NW WIND PREVENTING TEMPS FROM GETTING TOO FAR DESPITE
A FAIR AMOUNT OF INSOLATION. LOOK FOR HIGHS ONLY INTO THE MID-UPR
40S INLAND, WITH LOW/MID 40S OVER COASTAL ZONES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE OVER THE AREA WEDNESDAY NIGHT WILL GRADUALLY MOVE
THROUGH THURSDAY...PROVIDING DRY WX INTO THURSDAY NIGHT. THE NEXT
CHANCE OF PCPN COMES FRIDAY/SATURDAY...THEN THINGS DRY OUT AGAIN BY
NEXT SUNDAY. P-TYPE WILL NOT BE AN ISSUE DUE TO THE MILDER PATTERN.
MILDER THURSDAY WITH HIGHS IN THE 50S. SEASONABLE FRIDAY/SATURDAY
WITH HIGHS IN THE 60S. COLD WEDNESDAY NIGHT WITH LOWS 25-30...THEN
WARMING INTO THE 40S TO LOW 50S BY THE WEEKEND.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
MOST TAF SITES WILL START OUT WITH VFR CONDITIONS AT 18Z WITH
THE EXCEPTION OF RIC WHERE CEILINGS WILL FALL TO 3KFT OR LESS
SHORTLY AFTER 18Z WITH LIGHT RAIN. MVFR CEILINGS SHOULD SPREAD
EAST TO ALL OTHER SITES BETWEEN 19Z AND 20Z. MVFR CIGS ARE LIKELY
AT ALL SITES THROUGH THE AFTERNOON AS THE AREA OF LIGHT PRECIP
PUSHES THROUGH. HRRR MODEL SUGGESTS THE PRECIP WILL TAPER OFF AT
RIC AROUND 22Z...THEN EXIT THE COAST AROUND 00Z. THERE MAY BE
ANOTHER BRIEF CHANCE OF LIGHT RAIN WITH THE NEXT FRONT/SURGE LATE
THIS EVENING AND TONIGHT...BUT CONDITIONS SHOULD REMAIN MOSTLY VFR
WITH JUST A BRIEF PERIOD OF MVFR VSBY POSSIBLE WITH THE LIGHT
RAIN. IN GENERAL WIDESPREAD MVFR CONDITIONS SHOULD IMPROVE AFTER
00Z. NE WINDS WILL AVG 10-15 KT AT KORF/ECG THROUGH THE AFTERNOON
AND EVENING...GENLY 10 KT ELSEWHERE.
IMPROVING CONDITIONS AFTER 04-06Z TONIGHT AS N/NW WINDS BRING DRIER
AIR BACK TO THE AREA. MIXED PCPN WITH PERIODS OF IFR ARE INDICATED
FOR TUESDAY AND TUESDAY EVENING...AS ANOTHER SYSTEM MOVES ACROSS
THE REGION. THIS SYSTEM INTENSIFIES RAPIDLY OFF THE MID ATLANTIC
COAST TUESDAY NIGHT/WEDNESDAY...WITH LINGERING CHC FOR SNOW TUE
EVENING FOLLOWED BY STRONG NW WINDS AT ALL SITES LATER TUE NIGHT
INTO MIDDAY WED.
&&
.MARINE...
WINDS WILL CONTINUE TO DIMINISH OVER THE BAY AND NORTHERN COASTAL
ZONES LATE THIS AFTERNOON INTO THIS EVENING...AS A BRIEF LULL
BETWEEN TWO SURGES OF COLD AIR TAKES PLACE. THIS WILL NOT AFFECT THE
SCA`S THAT ARE CURRENTLY IN EFFECT AS THIS LULL IN WINDS IS EXPECTED
TO BE SHORT IN DURATION. THE 2ND SURGE LATER TONIGHT WILL BE THE
STRONGER OF THE TWO. IMPRESSIVE COLD AIR FOR LATE MARCH WILL ALLOW
FOR OPTIMAL MIXING AND SHOULD HAVE SOLID SCA CONDITIONS ALL ZONES
OVERNIGHT INTO MON MORNING WITH N/NW WINDS AVERAGING 20-25 KT WITH
GUSTS TO 30 KT.
HIGH PRESSURE BRIEFLY BUILDS INTO THE REGION MON AFTN...ALLOWING THE
GRADIENT TO ONCE AGAIN WEAKEN AND SUB-SCA CONDITIONS TO TAKE OVER. A
STRONG LOW PRESSURE SYSTEM IS FORECAST TO DEVELOP OFF THE SE COAST
TUE MORNING...AND RAPIDLY INTENSIFY LATE TUESDAY/WEDNESDAY. SOME
DIFFERENCES REMAIN AMONGST THE MODEL GUIDANCE...BUT THERE IS ENOUGH
AGREEMENT THAT CONFIDENCE FOR GALES IS INCREASING FOR TUE NIGHT/WED
AS VERY STRONG PRESSURE FALLS ARE EXPECTED WITH THIS SYSTEM. HAVE
GUSTS TO AROUND 40 KT FOR COASTAL WATERS AND 35-40 KT ELSEWHERE IN
THE GRIDDED FORECAST FOR NOW. IF THE SYSTEM WERE TO SLOW ITS
MOVEMENT NORTH...COULD EVEN SEE SOME STORM FORCE GUSTS ALONG THE
COASTAL WATERS WED. BECAUSE THE ONSET OF GALE FORCE CONDITIONS WOULD
NOT BE UNTIL TUESDAY NIGHT (5TH PERIOD)...WILL NOT GO WITH A GALE
WATCH ATTM. WAVES ON THE BAY ARE FORECAST TO REACH 4-5 FT TUES
NIGHT...WITH SEAS BUILDING TO 5-8 FT ON THE OCEAN.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT MONDAY FOR ANZ630>632-
634>638-650-652.
SMALL CRAFT ADVISORY UNTIL 1 PM EDT MONDAY FOR ANZ633.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT MONDAY FOR ANZ654-656-658.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...MAM/SAM
LONG TERM...JDM
AVIATION...JAO
MARINE...JDM/LKB
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
407 PM EDT SUN MAR 23 2014
.SYNOPSIS...
LOW PRESSURE MOVES OFF THE NORTH CAROLINA COAST TONIGHT...WITH HIGH
PRESSURE BUILDING IN FROM THE NORTHWEST MONDAY. LOW PRESSURE
TRACKS ACROSS THE SOUTHEASTERN STATES MONDAY NIGHT THEN OFF THE
MID ATLANTIC COAST TUESDAY. HIGH PRESSURE RETURNS WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
WHAT A DIFFERENCE A DAY MAKES...MID-AFTN RADAR MOSAIC SHOWING PCPN
PROPAGATING E-NE ACROSS THE CWA AS EXPECTED, WITH TEMPS FALLING
THROUGH THE 40S LATE THIS AFTN. HAVE ALSO HAD A FEW REPORTS OF
SOME WET SNOWFLAKES/ICE PELLETS MIXING IN AS PCPN ENDS ACROSS FAR
NW COUNTIES. WEAK PCPN RATE/WARM BL WILL PREVENT ANY OPERATIONAL
ISSUES, BUT IT CERTAINLY UNDERSCORES THE COLDER AIRMASS HEADED
OUR WAY THROUGH THE SHORT TERM PERIOD. CHC POPS WEST/CATEGORICAL
OUT EAST SLOWLY RAMP DOWN THROUGH EARLY EVENING AS SLUG OF
OVERRUNNING MOISTURE PUSHES OFFSHORE AHEAD OF HIGH PRESSURE TO THE
WEST. QUICK CLEARING TONIGHT/OVERNIGHT AS STRONG CANADIAN HIGH
PRESSURE (+1 STD DEV MSLP) BUILDS OVER THE GREAT LAKES TONIGHT. A
STRONG SECONDARY SURGE OF COLD/DRY AIR IS ALSO EXPECTED ACROSS
OUR REGION OVERNIGHT, WITH TEMPS FALLING INTO THE MID 20S- LOW 30S
(~10 DEGS BELOW NORMAL).
MODIFYING COLD/DRY HIGH PRESSURE BUILDS FROM THE OH VALLEY ACROSS
THE MID-ATLANTIC MONDAY, WITH WELL BELOW NORMAL TEMPS EXPECTED.
WHILE H85 TEMPS -2 STD DEV...LATE MARCH SUN WILL HELP WARM TEMPS
INTO THE MID 40S INLAND (~15 DEGS BELOW NORMAL). N-NE WINDS 10-15
MPH WILL RESULT IN AN ESPECIALLY BREEZY AND BRISK DAY OVER COASTAL
AREAS...WITH TEMPS ONLY WARMING INTO THE MID-UPPER 30S THANKS TO
COLD WATERS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
MONDAY NIGHT...CLEAR BRIEFLY MONDAY NIGHT AS HIGH PRESSURE PUSHES
OFFSHORE. WIND VEER AROUND TO THE S-SE AND CLOUDS INCREASE IN
ADVANCE OF THE NEXT SYSTEM. LOWS GENERALLY IN THE UPPER 20S-LOW
30S.
STRONG COASTAL LOW PRESSURE SYSTEM WILL BEGIN TO TAKE SHAPE MON
NIGHT AS A QUICK MOVING SHORTWAVE EMERGING FROM THE NORTHERN
PLAINS INTO THE OHIO VALLEY SHARPENS A LONGWAVE TROUGH OVER THE
ERN CONUS TUESDAY (-2 STD DEV 500MB HEIGHTS)...RESULTING IN
CYCLOGENESIS OFF THE SE COAST. STRONG HEIGHT FALLS AND A STRONG PV
ANOMALY WILL RESULT IN RAPID INTENSIFICATION OF THIS SFC LOW AS
IT LIFTS RAPIDLY NEWD ALONG THE SE AND MID-ATLANTIC COAST THROUGH
TUESDAY NIGHT. OVERALL...MODELS REMAIN IN DECENT AGREEMENT WITH
HANDLING THE HIGHLY AMPLIFIED UPPER PATTERN AND GENERAL SFC LOW
TRACK AND STRENGTH AS THE LOW LIFTS OFF THE SE COAST AND PUSHES
WELL OFF THE MID-ATLANTIC COAST TUESDAY AFTN/NIGHT. HOWEVER, SOME
SPATIAL AND TIMING DIFFERENCES CONTINUE WHICH COULD HAVE
MEANINGFUL DIFFERENCES WRT SENSIBLE WEATHER FOR THE LOCAL AREA.
HAVE SIDED CLOSER TO ECMWF BLENDED SOLUTION WITH THIS PACKAGE.
EXPECT TWO DISTINCT AREAS OF PCPN WITH THIS SYSTEM. INLAND, EXPECT
SOME MOISTURE TO PUSH ACROSS PIEDMONT/METRO REGION TUESDAY MORNING
AS UPPER SYSTEM INTENSIFIES MONDAY MORNING. THIS MOISTURE WILL BE
QUICK TO DEPART TUESDAY AFTN AS LOW-MIDLVL CYCLOGENESIS OCCURS
RAPIDLY TO OUR NORTHEAST TUESDAY NIGHT. THE SECOND AREA IS WITH
SECOND AREA OF ATLANTIC MOISTURE ADVECTED NORTH ACROSS THE COASTAL
PLAIN TUESDAY AFTN EVENING. THIS MOISTURE WILL LIFT NORTH ACROSS
EASTERN SECTIONS TUESDAY AFTN/EVENING BEFORE PUSHING OFFSHORE BY
LATE TUE NGT. THERMAL PROFILES CONTINUE TO SUGGEST THAT LIGHT SNOW
WILL BE POSSIBLE...AND IN FACT LIKELY ACROSS THE PIEDMONT (METRO
RIC)...WITH UPPER TROUGH. EXPECTATION REMAINS THAT WITH ONSET OF
PCPN COMING AT OR JUST AFTER SUNRISE...LGT PCPN RATES, MARCH SUN
AND MARGINAL BL TEMPS WOULD BE ENOUGH TO PRECLUDE ANY MAJOR
IMPACTS OR ACCUMULATION ISSUES. FARTHER SOUTH, EXPECT A BRIEF
PERIOD OF SNOW/SLEET/RN RIGHT AROUND SUNRISE ALONG AND SOUTH OF THE
HIGHWAY 58 CORRIDOR IN SOUTH CENTRAL VA, TRANSITIONING TO ALL RAIN
QUICKLY THEREAFTER...WITH LGT RAIN FOR ALL BUT FAR NORTHWEST IN
BY LATE MORNING. CUT BACK TO SHOWERS GRADUALLY FROM WEST TO EAST
AS MOISTURE RACES OFF TO THE NW, BUT DID HOLD ONTO CHANCE POPS
ALONG THE COAST TUESDAY NIGHT TO ACCOUNT FOR POTENTIAL WRAP AROUND
PRECIP INTO THE NE LOCAL AREA. STRONG SURGE OF COLD/DRY AIR
EXPECTED TUE NIGHT AS STRONG HIGH PRESSURE BUILDS IN FROM THE
WEST. CLEARING, WINDY AND COLD TUES NIGHT WITH LOWS IN THE 20S TO
NEAR 30.
HIGH PRESSURE BUILDS IN FROM THE WEST ON WED...WITH A CHILLY,
DRYING W-NW WIND PREVENTING TEMPS FROM GETTING TOO FAR DESPITE
A FAIR AMOUNT OF INSOLATION. LOOK FOR HIGHS ONLY INTO THE MID-UPR
40S INLAND, WITH LOW/MID 40S OVER COASTAL ZONES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE OVER THE AREA WEDNESDAY NIGHT WILL GRADUALLY MOVE
THROUGH THURSDAY...PROVIDING DRY WX INTO THURSDAY NIGHT. THE NEXT
CHANCE OF PCPN COMES FRIDAY/SATURDAY...THEN THINGS DRY OUT AGAIN BY
NEXT SUNDAY. P-TYPE WILL NOT BE AN ISSUE DUE TO THE MILDER PATTERN.
MILDER THURSDAY WITH HIGHS IN THE 50S. SEASONABLE FRIDAY/SATURDAY
WITH HIGHS IN THE 60S. COLD WEDNESDAY NIGHT WITH LOWS 25-30...THEN
WARMING INTO THE 40S TO LOW 50S BY THE WEEKEND.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
MOST TAF SITES WILL START OUT WITH VFR CONDITIONS AT 18Z WITH
THE EXCEPTION OF RIC WHERE CEILINGS WILL FALL TO 3KFT OR LESS
SHORTLY AFTER 18Z WITH LIGHT RAIN. MVFR CEILINGS SHOULD SPREAD
EAST TO ALL OTHER SITES BETWEEN 19Z AND 20Z. MVFR CIGS ARE LIKELY
AT ALL SITES THROUGH THE AFTERNOON AS THE AREA OF LIGHT PRECIP
PUSHES THROUGH. HRRR MODEL SUGGESTS THE PRECIP WILL TAPER OFF AT
RIC AROUND 22Z...THEN EXIT THE COAST AROUND 00Z. THERE MAY BE
ANOTHER BRIEF CHANCE OF LIGHT RAIN WITH THE NEXT FRONT/SURGE LATE
THIS EVENING AND TONIGHT...BUT CONDITIONS SHOULD REMAIN MOSTLY VFR
WITH JUST A BRIEF PERIOD OF MVFR VSBY POSSIBLE WITH THE LIGHT
RAIN. IN GENERAL WIDESPREAD MVFR CONDITIONS SHOULD IMPROVE AFTER
00Z. NE WINDS WILL AVG 10-15 KT AT KORF/ECG THROUGH THE AFTERNOON
AND EVENING...GENLY 10 KT ELSEWHERE.
IMPROVING CONDITIONS AFTER 04-06Z TONIGHT AS N/NW WINDS BRING DRIER
AIR BACK TO THE AREA. MIXED PCPN WITH PERIODS OF IFR ARE INDICATED
FOR TUESDAY AND TUESDAY EVENING...AS ANOTHER SYSTEM MOVES ACROSS
THE REGION. THIS SYSTEM INTENSIFIES RAPIDLY OFF THE MID ATLANTIC
COAST TUESDAY NIGHT/WEDNESDAY...WITH LINGERING CHC FOR SNOW TUE
EVENING FOLLOWED BY STRONG NW WINDS AT ALL SITES LATER TUE NIGHT
INTO MIDDAY WED.
&&
.MARINE...
WINDS WILL CONTINUE TO DIMINISH OVER THE BAY AND NORTHERN COASTAL
ZONES LATE THIS AFTERNOON INTO THIS EVENING...AS A BRIEF LULL
BETWEEN TWO SURGES OF COLD AIR TAKES PLACE. THIS WILL NOT AFFECT THE
SCA`S THAT ARE CURRENTLY IN EFFECT AS THIS LULL IN WINDS IS EXPECTED
TO BE SHORT IN DURATION. THE 2ND SURGE LATER TONIGHT WILL BE THE
STRONGER OF THE TWO. IMPRESSIVE COLD AIR FOR LATE MARCH WILL ALLOW
FOR OPTIMAL MIXING AND SHOULD HAVE SOLID SCA CONDITIONS ALL ZONES
OVERNIGHT INTO MON MORNING WITH N/NW WINDS AVERAGING 20-25 KT WITH
GUSTS TO 30 KT.
HIGH PRESSURE BRIEFLY BUILDS INTO THE REGION MON AFTN...ALLOWING THE
GRADIENT TO ONCE AGAIN WEAKEN AND SUB-SCA CONDITIONS TO TAKE OVER. A
STRONG LOW PRESSURE SYSTEM IS FORECAST TO DEVELOP OFF THE SE COAST
TUE MORNING...AND RAPIDLY INTENSIFY LATE TUESDAY/WEDNESDAY. SOME
DIFFERENCES REMAIN AMONGST THE MODEL GUIDANCE...BUT THERE IS ENOUGH
AGREEMENT THAT CONFIDENCE FOR GALES IS INCREASING FOR TUE NIGHT/WED
AS VERY STRONG PRESSURE FALLS ARE EXPECTED WITH THIS SYSTEM. HAVE
GUSTS TO AROUND 40 KT FOR COASTAL WATERS AND 35-40 KT ELSEWHERE IN
THE GRIDDED FORECAST FOR NOW. IF THE SYSTEM WERE TO SLOW ITS
MOVEMENT NORTH...COULD EVEN SEE SOME STORM FORCE GUSTS ALONG THE
COASTAL WATERS WED. BECAUSE THE ONSET OF GALE FORCE CONDITIONS WOULD
NOT BE UNTIL TUESDAY NIGHT (5TH PERIOD)...WILL NOT GO WITH A GALE
WATCH ATTM. WAVES ON THE BAY ARE FORECAST TO REACH 4-5 FT TUES
NIGHT...WITH SEAS BUILDING TO 5-8 FT ON THE OCEAN.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT MONDAY FOR ANZ630>632-
634>638-650-652.
SMALL CRAFT ADVISORY UNTIL 1 PM EDT MONDAY FOR ANZ633.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT MONDAY FOR ANZ654-656-658.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...MAM/SAM
LONG TERM...JDM
AVIATION...JAO
MARINE...JDM/LKB
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
203 PM EDT SUN MAR 23 2014
.SYNOPSIS...
LOW PRESSURE TRACKS ACROSS THE CAROLINAS TODAY...THEN MOVES OFF
THE NORTH CAROLINA COAST TONIGHT. HIGH PRESSURE BUILDS IN FROM THE
NORTHWEST MONDAY. LOW PRESSURE TRACKS ACROSS THE SOUTHEASTERN
STATES MONDAY NIGHT THEN OFF THE MID ATLANTIC COAST TUESDAY. HIGH
PRESSURE RETURNS WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
COLD FRONT HAS PUSHED SOUTH OF THE AREA WELL INTO THE CAROLINAS AT
MIDDAY. STILL ON TRACK TO SEE SHOWERS MOVE ACROSS THE AREA THIS
AFTERNOON AND THIS EVENING IN ASSOCIATION WITH SRN STREAM ENERGY.
IR SAT SHOWING COOLING CLOUD TOPS ACROSS THE TN VLY AND WESTERN
CAROLINAS THIS MORNING, COINCIDENT WITH BEST OVERRUNNING MOISTURE.
SYSTEM WILL BE ABLE TO ACCESS GULF MOISTURE...BUT ONLY LIMITED
MOISTURE WILL BE ABLE TO ADVECT INTO THE REGION DUE TO DRY MIDLVLS
COURTESY OF DOWNSLOPE/WLY FLOW ALOFT. TEMPS HAVE WARMED SLIGHTLY
AHEAD OF THE SYSTEM THIS MORNING INTO THE UPPER 40S TO NEAR 50
(MILDER AIR TO THE SE). EXPECT TO SEE TEMPS FALLING THROUGH THE
AFTERNOON AS RAIN MOVES IN. RAIN WILL MOVE WEST TO EAST THROUGH
ABOUT 02Z, WITH PARTIAL CLEARING OUT IN THE PIEDMONT POSSIBLE BY
SUNSET. GIVEN THE QUICK MOTION OF THE SYSTEM (DUE TO PROGRESSIVE
QUASI-ZONAL FLOW), WEAK FORCING AND LIMITED MOISTURE...HIGH POP/LOW
QPF IS EXPECTED. CATEGORICAL POPS SOUTH OF RIC-PHF-WAL LINE, WITH
HIGH END CHC TO LIKELY POP NORTHERN NECK/EASTERN SHORE FOR THE
MID-LATE AFTN. QPF REMAINS GENERALLY LESS THAN ONE QUARTER OF AN
INCH. THE HIGHEST AMOUNTS WILL BE CONFINED TO SRN VA AND NE NC.
STRONG CANADIAN HIGH PRESSURE (+1 STD DEV MSLP) BUILDS OVER THE
GREAT LAKES TONIGHT WITH A STRONG SURGE OF COLD/DRY AIR INTO THE
REGION OVERNIGHT. SKIES WILL RAPIDLY CLEAR SUN NIGHT AS TEMPS FALL
INTO THE MID 20S-LOW 30S (~10 DEGS BELOW NORMAL).
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
MONDAY AND MONDAY NIGHT...
MODIFYING COLD/DRY HIGH PRESSURE BUILDS FROM THE OH VALLEY INTO
THE MID-ATLANTIC MONDAY. WELL BELOW NORMAL TEMPS EXPECTED AS H85
TEMPS WILL BE -2 STD DEV. HOWEVER...LATE MARCH SUN WILL HELP WARM
TEMPS INTO THE MID 40S INLAND (~15 DEGS BELOW NORMAL). N-NE WINDS
10-15 MPH WILL RESULT IN COLDER CONDITIONS ALONG THE COAST...WITH
TEMPS ONLY WARMING INTO THE MID-UPPER 30S THANKS TO COLD WATERS.
HIGH PRESSURE WILL PUSH OFFSHORE MONDAY EVENING AS WINDS BECOME
S-SE AND CLOUDS INCREASE IN ADVANCE OF THE NEXT SYSTEM. LOWS
GENERALLY IN THE UPPER 20S-LOW 30S.
STRONG COASTAL LOW TUESDAY AND TUESDAY NIGHT...
STRONG COASTAL LOW PRESSURE SYSTEM WILL BEGIN TO TAKE SHAPE MON
NIGHT AS A LONGWAVE TROUGH SHARPENS OVER THE ERN CONUS (-2 STD DEV
500MB HEIGHTS)...RESULTING IN CYCLOGENESIS OFF THE SE COAST. STRONG
HEIGHT FALLS AND A STRONG PV ANOMALY WILL RESULT IN RAPID
INTENSIFICATION OF THE SFC LOW AS IT LIFTS RAPIDLY NEWD ALONG THE
SE AND MID-ATLANTIC COAST THROUGH TUESDAY NIGHT. OVERALL...MODELS
IN DECENT AGREEMENT WITH HANDLING THE HIGHLY AMPLIFIED UPPER
PATTERN AND GENERAL SFC LOW TRACK AND STRENGTH AS THE LOW LIFTS
ALONG THE SE COAST AND OFF THE MID-ATLANTIC COAST TUESDAY NIGHT.
HOWEVER...SPATIAL AND TIMING DIFFERENCES DO EXIST WHICH COULD HAVE
MEANINGFUL DIFFERENCES WRT SENSIBLE WEATHER FOR THE LOCAL AREA.
HAVE SIDED CLOSER TO A SLOWER CMC/ECMWF BLENDED SOLUTION WITH THIS
PACKAGE, WHICH MAKES A BIT MORE SENSE THAN THE MORE
PROGRESSIVE/FLATTER GFS SOLUTION GIVEN THE STRONG, DIGGING
SHORTWAVE UPSTREAM. THIS SOLUTION DOES BRING A FEW COMPLICATIONS
HOWEVER. A SLOWER SOLUTION WOULD PREVENT PHASING BETWEEN NORTHERN
STREAM WAVE AND SOUTHERN ENERGY UNTIL LATER WED/WED NIGHT...AND BY
THEN SYSTEM IS WELL OFF TOWARDS NEW ENGLAND COASTLINE. THUS, ONLY
LIGHT QPF IS ANTICIPATED TUESDAY MORNING OVER THE LOCAL AREA. SO
WHILE LIGHT SNOW WILL BE POSSIBLE...AND IN FACT LIKELY ACROSS THE
PIEDMONT WITH UPPER TROUGH...EXPECTATION ATTM IS THAT WITH ONLY
LGT SNOW, MARCH SUN AND MARGINAL BL TEMPS WOULD BE SUFFICIENT TO
PRECLUDE ANY MAJOR IMPACT OR ACCUMULATION ISSUES. FARTHER SOUTH,
EXPECT A CHANCE FOR RAIN/SNOW BEFORE 12Z ACROSS THE I-85 CORRIDOR
IN SOUTH CENTRAL VA, TRANSITIONING TO ALL RAIN SHORTLY AFTER
SUNRISE, WITH LGT RAIN FOR ALL BUT FAR NORTHWEST IN THE AFTN. FROM
THERE...FORECAST CONFIDENCE GOES DOWN A BIT WITH A FEW DETAILS YET
TO BE IRONED OUT. WILL HOLD ONTO CHANCE POPS ALONG THE COAST
TUESDAY NIGHT TO ACCOUNT FOR POTENTIAL WRAP AROUND PRECIP INTO THE
NE LOCAL AREA. STRONG SURGE OF COLD/DRY AIR EXPECTED TUES NIGHT AS
STRONG HIGH PRESSURE BUILDS IN FROM THE WEST. CLEARING AND COLD
TUES NIGHT WITH LOWS IN THE 20S TO NEAR 30.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
HIGH PRESSURE RETURNS WEDNESDAY/THURSDAY FOR DRY WX. THE NEXT
CHANCE OF PCPN MAY COME AGAIN FRIDAY INTO NEXT WEEKEND. P-TYPE
WILL NOT BE AN ISSUE DUE TO THE MILDER PATTERN. CHILLY WEDNESDAY
WITH HIGHS ONLY IN THE 40S. MILDER THURSDAY WITH HIGHS IN THE 50S.
SEASONABLE FRIDAY/SATURDAY WITH HIGHS IN THE 60S. COLD WEDNESDAY
NIGHT WITH LOWS 25-30...THEN WARMING INTO THE 40S TO LOW 50S BY
THE WEEKEND.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
MOST TAF SITES WILL START OUT WITH VFR CONDITIONS AT 18Z WITH
THE EXCEPTION OF RIC WHERE CEILINGS WILL FALL TO 3KFT OR LESS
SHORTLY AFTER 18Z WITH LIGHT RAIN. MVFR CEILINGS SHOULD SPREAD
EAST TO ALL OTHER SITES BETWEEN 19Z AND 20Z. MVFR CIGS ARE LIKELY
AT ALL SITES THROUGH THE AFTERNOON AS THE AREA OF LIGHT PRECIP
PUSHES THROUGH. HRRR MODEL SUGGESTS THE PRECIP WILL TAPER OFF AT
RIC AROUND 22Z...THEN EXIT THE COAST AROUND 00Z. THERE MAY BE
ANOTHER BRIEF CHANCE OF LIGHT RAIN WITH THE NEXT FRONT/SURGE LATE
THIS EVENING AND TONIGHT...BUT CONDITIONS SHOULD REMAIN MOSTLY VFR
WITH JUST A BRIEF PERIOD OF MVFR VSBY POSSBILE WITH THE LIGHT
RAIN. IN GENERAL WIDESPREAD MVFR CONDITIONS SHOULD IMPROVE AFTER
00Z. NE WINDS WILL AVG 10-15 KT AT KORF/ECG THROUGH THE AFTERNOON
AND EVENING...GENLY 10 KT ELSEWHERE.
IMPROVING CONDITIONS AFTER 04-06Z TONIGHT AS N/NW WINDS BRING DRIER
AIR BACK TO THE AREA. MIXED PCPN WITH PERIODS OF IFR ARE INDICATED
FOR TUESDAY AND TUESDAY EVENING...AS ANOTHER SYSTEM MOVES ACROSS
THE REGION. THIS SYSTEM INTENSIFIES RAPIDLY OFF THE MID ATLANTIC
COAST TUESDAY NIGHT/WEDNESDAY...WITH LINGERING CHC FOR SNOW TUE
EVENING FOLLOWED BY STRONG NW WINDS AT ALL SITES LATER TUE NIGHT
INTO MIDDAY WED.
&&
.MARINE...
WINDS HAVE DECREASED SOME OVER THE MIDDLE AND NORTHERN BAY THIS
AFTERNOON...HOWEVER WINDS WILL INCREASE LATER TONIGHT. THERE WILL
BE A LULL IN SCA CONDITIONS THIS AFTN AND EVENING OVER THE
NORTHERN BAY AND NORTHERN COASTAL WATERS...BUT DUE TO THE SHORT
DURATION...HAVE RETAINED THE PREVIOUS HEADLINE TIMING TO COVER THE
2ND SURGE LATER TONIGHT (WHICH IS THE STRONGER ONE). IMPRESSIVE
COLD AIR FOR LATE MARCH WILL ALLOW FOR OPTIMAL MIXING AND SHOULD
HAVE SOLID SCA CONDITIONS ALL ZONES OVERNIGHT INTO MON MORNING
WITH N/NW WINDS AVERAGING 20-25 KT WITH GUSTS TO 30 KT.
HIGH PRESSURE BRIEFLY BUILDS INTO THE REGION MON AFTN...ALLOWING THE
GRADIENT TO ONCE AGAIN WEAKEN AND SUB-SCA CONDITIONS TO TAKE OVER. A
STRONG LOW PRESSURE SYSTEM IS FORECAST TO DEVELOP OFF THE SE COAST
TUE MORNING...AND RAPIDLY INTENSIFY LATE TUESDAY/WEDNESDAY. SOME
DIFFERENCES REMAIN AMONGST THE MODEL GUIDANCE...BUT ENOUGH
AGREEMENT THAT CONFIDENCE FOR GALES IS INCREASING FOR TUE
NIGHT/WED AS VERY STRONG PRESSURE FALLS ARE EXPECTED WITH THIS
SYSTEM. HAVE GUSTS TO AROUND 40 KT FOR COASTAL WATERS AND 35-40 KT
ELSEWHERE IN THE GRIDDED FORECAST FOR NOW. IF THE SYSTEM WERE TO
SLOW ITS MOVEMENT NORTH...COULD EVEN SEE SOME STORM FORCE GUSTS
ALONG THE COASTAL WATERS WED.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 10 AM EDT MONDAY FOR
ANZ635>637-650-652.
SMALL CRAFT ADVISORY UNTIL 10 AM EDT MONDAY FOR ANZ630>632-634-
638.
SMALL CRAFT ADVISORY UNTIL 1 PM EDT MONDAY FOR ANZ633.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT MONDAY FOR ANZ654-656-658.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM/SAM
SHORT TERM...SAM
LONG TERM...JDM
AVIATION...LKB/JAO
MARINE...JDM/LKB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
706 PM EDT MON MAR 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 415 PM EDT MON MAR 24 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE OVER
WRN NOAM AND A TROUGH FROM HUDSON BAY THROUGH MUCH OF THE ERN CONUS.
AN UPSTREAM SHORTWAVE TROUGH AND ASSOCIATED ARCTIC COLD FRONT
EXTENDED FROM NEAR JAMES BAY TO FAR NW MN. TO THE NORTH OF THE FRONT
19Z TEMPS ONLY RANGED FROM 0F TO 5F. AT THE SFC...WRLY LOW LEVEL
FLOW PREVAILED AHEAD OF THE FRONT WITH ONLY SCT-BKN DIURNAL CU/SC
OVER UPPER MICHIGAN.
TONIGHT...AS THE SHORTWAVE TROUGH AND COLD FRONT MOVE ACROSS THE NRN
GREAT LAKES SOME WEAK Q-VECT CONV...SFC-700 MB MOISTENING AND LOW
LEVEL CONV SHOULD SUPPORT SCT LIGHT SNOW SHOWERS OR FLURRIES...PER
UPSTREAM OBS. THE GREATEST PCPN CHANCES AND POTENTIAL FOR SOME LIGHT
ACCUMULATIONS OF AN INCH OR LESS IS EXPECTED DOWNWIND FROM LAKE
SUPERIOR WHERE EVEN SMALL GAPS IN THE ICE COVER WILL ADD
HEAT/INSTABILITY. UPSLOPE FLOW INTO THE HIGHER TERRAIN WILL ALSO
PROVIDE ADDITIONAL SUPPORT FOR THE PCPN. LOOK FOR MIN TEMPS MAINLY IN
THE SINGLE DIGITS ABOVE ZERO BUT A FEW BLO ZERO READINGS ARE POSSIBLE
OVER THE EASTERN INTERIOR FCST AREA WHERE WINDS WILL BE LIGHTER AHEAD
OF THE FRONT IN THE EVENING.
TUESDAY...AS HIGH PRESSURE AND SUBSIDENCE BUILD INTO THE WRN
LAKES...THE 850-700 MB MOISTURE DEPARTS AND WINDS BACK TO
WRLY...EXPECT THE PCPN TO DIMINISH WITH ONLY A LIGHT DUSTING OF
ACCUMULATION AT MOST. WITH 925/850 MB TEMPS ONLY TO AROUND
-16/-22C...TEMPS WILL STRUGGLE THROUGH THE MID TEENS...MORE THAN 20
DEGREES BELOW SEASONAL AVERAGES.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 438 PM EDT MON MAR 24 2014
THE EXTENDED PORTION OF THE FORECAST IS TRENDING TOWARDS A MORE
ACTIVE AND SPRING LIKE PATTERN.
A HIGH PRESSURE RIDGE MOVING OVER THE UPPER GREAT LAKES REGION TO
START THE PERIOD WILL LEAD TO ANOTHER VERY COLD NIGHT ACROSS THE
UPPER GREAT LAKES REGION ON TUESDAY NIGHT. THERE ARE SOME CONCERNS
FOR CLOUDS LINGERING...BUT WITH THE VERY LIMITED OPEN WATER ON LAKE
SUPERIOR WOULD THINK THERE IS A LACK OF SUPPORT FOR LAKE ENHANCED
CLOUDS TO LINGER. THUS...WOULD EXPECT CLEARING SKIES AND A DECENT
OPPORTUNITY FOR RADIATIONAL COOLING WITH WINDS BECOMING LIGHT.
SINCE PWAT VALUES ARE AROUND 30 PERCENT OF NORMAL...OPTED TO TREND
TEMPS DOWN (BASED OFF THE LAST TWO NIGHTS OF LOWS)...ESPECIALLY IN
THE TRADITIONAL INTERIOR COLD SPOTS. THIS PRODUCES LOWS BELOW ZERO
OVER PRETTY MUCH ALL OF THE U.P. AND IN THE TEENS BELOW ZERO OVER
THE INTERIOR. BASED OFF THE TRENDS IN THE LONGER RANGE
MODELS...THIS WILL LIKELY BE THE LAST REALLY COLD NIGHT ACROSS THE
REGION.
THE SURFACE RIDGE WILL QUICKLY SHIFT EAST OF THE AREA ON WEDNESDAY
AND ALLOW SOUTHERLY FLOW TO DEVELOP AHEAD OF THE LOW TAKING SHAPE
IN THE CENTRAL PLAINS. THIS SOUTHERLY FLOW WILL ALLOW TEMPERATURES
TO QUICKLY WARM INTO THE 20S (AIDED BY MORNING SUNSHINE). BUT HIGH
CLOUDS WILL BE QUICKLY STREAMING OVER THE AREA THROUGH THE DAY
AHEAD OF THE NEXT SYSTEM. COULD EVEN SEE A ISOLATED SHOWER OR TWO
DEVELOPING UNDER THE MID LEVEL WAA LATE IN THE AFTERNOON.
THE FIRST WAVE FROM THE SYSTEM WILL AFFECT THE AREA ON WEDNESDAY
NIGHT...AS A SURFACE TROUGH EXTENDING NORTHEAST FROM THE DEVELOPING
SURFACE LOW MOVES EAST OVER THE CWA. BROAD MID LEVEL WARM AIR
ADVECTION AND ISENTROPIC ASCENT ON THE 280-295K SFCS SHOULD LEAD TO
A SWATH OF LIGHT SNOW. AS WITH THE NEXT SYSTEM...MODELS VARY
SIGNIFICANTLY WITH THE STRENGTH AND LOCATION OF THIS AREA OF
SNOW. THE 12Z ECMWF IS THE FARTHEST NORTH (OVER LAKE SUPERIOR) AND
WEAKEST...12Z CANADIAN FARTHEST SOUTH (ACROSS THE U.P.) AND
STRONGEST...WHILE THE GFS IS IN BETWEEN. FELT THAT THE GFS WAS A
GOOD COMPROMISE BETWEEN THE SOLUTIONS AND FOLLOWED THAT FOR TIMING
AND SNOWFALL AMOUNTS. THAT GIVES A GENERAL 1-3 INCHES OF SNOW FOR
THE CWA (GREATEST NORTH THIRD) THROUGH 12Z THURSDAY.
NEXT WAVE OF PRECIP WILL ARRIVE AS THE LOW PULLS OUT OF THE CENTRAL
PLAINS AND THROUGH THE GREAT LAKES REGION. STILL SOME DIFFERENCES IN
THE EXACT TRACK/TIMING BUT AT LEAST INITIALLY THE MODELS ARE
CONSISTENT IN A TROUGH EXTENDING NORTH-NORTHEAST OVER WESTERN LAKE
SUPERIOR. AS FOR THE LOW...THE 12Z GFS CONTINUES TO MOVE THE LOW
THROUGH MUCH FASTER THAN THE 12Z GEM AND 12Z ECMWF (270MI/520MI
NORTHEAST AT 12Z FRIDAY RESPECTIVELY). THE 12Z GEM WAS MUCH FARTHER
TO THE NORTHWEST AND BROUGHT IN MUCH MORE WARM AIR (0C 850MB LINE IN
FAR WESTERN UPPER MICHIGAN AT 00Z FRIDAY). 12Z ECMWF...EVEN WITH
IT/S FARTHER SOUTHWEST LOW TRACK (THROUGH CENTRAL LOWER MI ON
FRIDAY) HAS THE 0C 925MB TEMP AREA SLIDING THROUGH SOUTHERN
UPPER MICHIGAN DURING THE DAY THURSDAY. THE GFS ON THE OTHER
HAND...MOVES THE LOW THROUGH SO FAST THAT THE WARM AIR DOESN/T HAVE
TIME TO PULL INTO THE AREA AND KEEPS IT AS ALL SNOW.
ESSENTIALLY...THESE DIFFERENCES ARE DUE TO THE HANDLING OF THE
DISTURBANCE THAT IS WELL OFFSHORE IN THE PACIFIC AND WON/T COME ON
SHORE UNTIL TUESDAY NIGHT. IT WILL PROBABLY BE 24-36HRS BEFORE THE
MODELS CAN LOCK INTO A SOLUTION...BUT FEEL A SEVERAL MEMBER
COMPROMISE IS REASONABLE (GEM/ECMWF FOR TIMING AND GFS/ECMWF/UKMET
FOR TRACK AND ECMWF FOR THERMAL PROFILE). FELT WEIGHTING MORE
HEAVILY TOWARDS THE ECMWF WAS WARRANTED BASED OFF THE CONSISTENCY
IN THE LOW TRACK WITH THE 00Z ENSEMBLE MEMBERS.
UNFORTUNATELY...THESE DIFFERENCE IN THE LOW TRACK AFFECT BOTH THE
PRECIPITATION TYPE FOR A PORTION OF THE AREA AND ALSO WHERE THE
HEAVIEST PRECIPITATION WILL BE LOCATED WITH THE DEFORMATION BAND ON
THE BACKSIDE OF THE LOW. AS THE LOW IS TAKING SHAPE ON
THURSDAY...SHOULD SEE A TROUGH SETTING UP OVER WESTERN LAKE SUPERIOR
AND WOULD EXPECT THE HEAVIEST PRECIPITATION TO BE OVER THE WESTERN
THIRD OF THE CWA AND THE WESTERN LAKE AS IT WILL BE ENHANCED BY
MID-LEVEL FGEN. OVER THE REST OF THE AREA AND ESPECIALLY THE SOUTH
CENTRAL...WOULD EXPECT THE WAA PRECIPITATION TO SHIFT OUT AND
DIMINISH AND POTENTIALLY CUT OUT THE DEEPER MOISTURE ON THURSDAY.
THIS COULD LEAD TO MORE OF A FOG/DRIZZLE PERIOD...BUT WITH THE
UNCERTAINTY WITH THE LOW TRACK WILL JUST KEEP THINGS AS SNOW WITH
RAIN MIXED IN AT TIMES. THEN AS THE LOW MOVES UP AND THROUGH THE
AREA...THE HEAVIER BAND OF PRECIP WILL SHIFT EAST ACROSS THE CWA
THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. ALL IN ALL...THE
CONDITIONS WEDNESDAY NIGHT INTO FRIDAY MORNING WILL LIKELY LEAD TO A
PERIOD OF MESSY TRAVEL/COMMUTES AND WILL CONTINUE TO HIGHLIGHT IN
THE HWO.
BEHIND THE LOW...HIGH PRESSURE WILL SETTLE OVER THE AREA FOR FRIDAY
NIGHT AND INTO SATURDAY. 850MB TEMPS OF -12C ARE PRETTY MARGINAL
FOR ANY LAKE EFFECT IF POCKETS OF OPEN WATER DEVELOP ON LAKE
SUPERIOR...SO WILL GO WITH DRY CONDITIONS ON FRIDAY NIGHT. THE HIGH
WILL SHIFT EAST ON SATURDAY AND SOUTHERLY FLOW SHOULD LEAD TO HIGHS
IN THE 30S.
FOCUS THEN TURNS TO THE NEXT SERIES OF WAVES COMING FROM THE
WESTERN CONUS AND BRINGING ANOTHER UNSETTLED PERIOD TO THE AREA
THROUGH THE FIRST HALF OF NEXT WEEK. THE FIRST POTENTIAL WAVE LOOKS
TO RUN EAST ON THE U.S./CANADIAN BORDER ON SATURDAY NIGHT AND
SHOULD HAVE A LIMITED AFFECT ON THE LAND CWA. BEHIND THIS
WAVE...MUCH WARMER AIR WILL MOVE INTO THE AREA AND CURRENT
INDICATIONS ARE FOR TEMPERATURES TO BE AT OR EVEN SLIGHTLY ABOVE
NORMAL FOR SUNDAY. GFS CONTINUES TO SHOW ISSUES WITH SNOW COVER AND
SURFACE TEMPS...SO WILL LEVERAGE THE CANADIAN/ECMWF FOR HIGHS ON
SUNDAY. SHOULD SEE 40S OVER MUCH OF THE AREA (EXCEPT OVER THE EAST
WITH WINDS OFF LAKE MICHIGAN) AND THERE IS EVEN THE POTENTIAL FOR
SOME 50S ALONG THE WISCONSIN BORDER. THE NEXT SHORTWAVE AND COLD
FRONT WILL BE SHIFTING THROUGH THE AREA LATE SUNDAY AFTERNOON AND
SUNDAY NIGHT AND WITH THE EXPECTED THERMAL PROFILE...THAT
PRECIPITATION SHOULD MAINLY FALL AS RAIN. LIKE THE END OF THIS
WEEK...ANOTHER LOW TAKING SHAPE IN THE PLAINS STATES ON SUNDAY WILL
LIKELY MOVE THROUGH THE GREAT LAKES REGION ON MONDAY AND MONDAY
NIGHT...BRINGING ANOTHER WIDESPREAD PRECIPITATION EVENT TO THE AREA.
INITIAL THOUGH ON P-TYPE IS FOR A MIX INITIALLY AND TRANSITIONING TO
ALL SNOW THROUGH THE DAY/EVENING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 706 PM EDT MON MAR 24 2014
WITH THE PASSAGE OF A DISTURBANCE TONIGHT...SCT -SHSN WILL THEN
LIKELY DEVELOP AT KIWD/KSAW WITH POTENTIAL OF BRIEF MVFR VIS AT
TIMES...ESPECIALLY AT KIWD. BY LATE TONIGHT INTO TUE MORNING...THE
COMBINATION OF LOW LEVEL CONV AND UPSLOPE FLOW WILL BE ENOUGH TO
SUPPORT MVFR CIGS. WILL BE VFR CONDITIONS INTO THIS EVENING BEFORE
THE SNOW ARRIVES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 415 PM EDT MON MAR 24 2014
A COLD FRONT WILL MOVE THROUGH THE NRN LAKES TONIGHT. BEHIND THE
FRONT...WINDS WILL SHIFT TO THE NORTHWEST AND INCREASE TO 15 TO 25
KT TONIGHT AND 20 TO 30 KTS ON TUESDAY...WITH THE HIGHEST GUSTS OVER
THE EASTERN HALF OF LAKE SUPERIOR. WINDS WILL QUICKLY DIMINISH
TUESDAY NIGHT AND WEDNESDAY AS ANOTHER HIGH PRESSURE RIDGE MOVES
OVER THE AREA. A LOW PRESSURE SYSTEM DEVELOPING IN THE CENTRAL
PLAINS ON WEDNESDAY NIGHT AND THURSDAY WILL MOVE THROUGH THE GREAT
LAKES REGION LATE THURSDAY NIGHT AND FRIDAY. WIND STRENGTH/DIRECTION
WILL DEPEND ON THE EXACT TRACK OF THE LOW...BUT AT THIS TIME NORTH
TO NORTHEAST WINDS OF 15 TO 25 KTS ARE EXPECTED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
218 PM EDT SUN MAR 23 2014
.SYNOPSIS...
ISSUED AT 300 AM EDT SUN MAR 23 2014
HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE GREAT LAKES REGION
THROUGH MONDAY. COLD AIR ASSOCIATED WITH THIS PATTERN WILL MAINTAIN
BELOW NORMAL TEMPERATURES ACROSS NORTHERN MICHIGAN INTO THE UPCOMING
WORK WEEK. THE NEXT SIGNIFICANT SYSTEM TO AFFECT THE GREAT LAKES
WILL ARRIVE DURING THE LAST HALF OF THE WEEK AS A STORM SYSTEM
ORGANIZES OVER THE PLAINS AND LIFTS INTO THE OHIO VALLEY. THIS
PATTERN WILL GENERATE ANOTHER ROUND OF EARLY SPRING SNOWS OVER
NORTHERN MICHIGAN WEDNESDAY NIGHT THROUGH FRIDAY.
&&
.UPDATE...
ISSUED AT 203 PM EDT SUN MAR 23 2014
PUSHED THE SNOW SHOWERS INLAND BASED ON THE SATELLITE AND RADAR
IMAGES. THE DRY AIR DOESN`T SEEM TO AFFECTING THE BANDS MUCH AS
THE OPEN WATER ON THE WEST SIDE OF LAKE MICHIGAN IS. THERE IS A
SHARP LINE OF WHERE THE SNOW SHOWERS STOP NORTH OF A LINE FROM
KMGN TO KOSC. ALTHOUGH, THERE HAS BEEN SOME DEVELOPMENT FROM LAKE
SUPERIOR TO AROUND KSLH/KPZQ/KAPN IN NE LOWER. WILL WATCH THESE
AND SEE IF THEY BECOME MORE THAN FLURRIES OVER THE NEXT COUPLE OF
HOURS.
UPDATE ISSUED AT 1124 AM EDT SUN MAR 23 2014
UPDATED THE GRIDS EARLIER, BUT MAY HAVE TO MAKE MORE CHANGES AS
THE LAKE STREAMERS ARE CONTINUING TO DEPOSIT LIGHT SNOW SHOWERS
INTO NW LOWER, MAINLY WEST OF US-131 AND SOUTH OF M-32. WHILE MOST
PLACES ARE GETTING FLURRIES NEAR THESE BANDS, THERE AREA SOME
PLACES THAT WILL GET MINOR TO LIGHT ACCUMULATIONS.
UPDATE ISSUED AT 645 AM EDT SUN MAR 23 2014
LAKE EFFECT FLURRIES HAVE ORGANIZED AND DEVELOPED INTO LAKE EFFECT
SNOW BANDS STREAMING SOUTHWARD ALONG THE LENGTH OF GRAND TRAVERSE
BAY INTO THE TVC AREA. LATEST OBS FROM MBL ALSO SUGGEST SNOW
SHOWER ACTIVITY IN THIS REGION WITH VSBYS FALLING TO 3SM. HAVE
INCREASED POPS TO SCATTERED MEASURABLE SNOW SHOWERS FOR OUR FAR SW
CWA EARLY THIS MORNING BEFORE DIURNAL MIXING/HEATING LENDS TO
DISORGANIZATION OF LAKE BANDING. ANY NEW SNOW ACCUMULATION WILL BE
WELL UNDER AN INCH. REST OF OUR CWA WILL SEE SCT/BKN LAKE CLOUDS
AND FLURRIES THRU THE DAY. ANOTHER COLD DAY IS IN STORE FOR THE
NORTHWOODS...WITH AFTERNOON HIGHS ONLY REACHING INTO THE UPPER
TEENS AND LOWER 20S.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 300 AM EDT SUN MAR 23 2014
...RIDICULOUSLY COLD FOR THE LATTER HALF OF MARCH!...
HIGH IMPACT WEATHER POTENTIAL: NONE.
OVERVIEW: FLOOD GATES TO ANOTHER ROUND OF ARCTIC AIR HAVE
OPENED...COURTESY OF DEEP NORTHWEST FLOW ON FRONT SIDE OF
SPRAWLING HIGH PRESSURE BUILDING THROUGH THE NORTHERN HIGH PLAINS.
LATEST HIGH RES RUC GUIDANCE HAS -20C H8 BUILDING INTO THE
NORTHERN PARTS OF OUR AREA AT THIS EARLY HOUR...NEARLY 2 STANDARD
DEVIATIONS BELOW NORMAL FOR THIS TIME OF YEAR (WAS ALREADY -18C ON
LOCAL 00Z SOUNDING). IMPRESSIVE COLD INDEED! REMNANT PRESSURE
GRADIENT/ASSOCIATED WINDS HAVE KEPT SURFACE TEMPERATURES FROM
TANKING TO THEIR FULL POTENTIAL GIVEN MAINLY CLEAR SKIES AND AN
UNSEASONABLY COLD AIRMASS. STILL...CURRENT READINGS FALLING INTO
AND THROUGH THE SINGLE DIGITS COLD ENOUGH FOR SURE...AND ARE A
GOOD 10 TO 15 DEGREES BELOW NORMAL FOR THIS DATE. DESPITE THESE
COLD CONDITIONS AND OPEN POCKETS OF GREAT LAKES WATER...DRY
AIRMASS AND LOW INVERSION HEIGHTS HAVE TAKEN THEIR COLLECTIVE TOLL
ON LAKE RESPONSE...WITH JUST A FEW LINGERING FLURRIES UNDER NNW
FLOW STCU DECK.
PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE/CLOUD TRENDS AND
LIGHT LAKE EFFECT SNOW POTENTIAL.
FORECAST DETAILS: HIGH CONFIDENCE PORTION OF THE FORECAST CENTERS ON
TEMPERATURES...WHICH WILL NO DOUBT REMAIN ON THE FRIGID SIDE. LATE
MARCH DIURNAL TREND WILL TRY ITS BEST TO MODIFY THINGS A TOUCH
TODAY...BUT WILL LARGELY LOSE THE BATTLE GIVEN -20C H8 AIR OVERHEAD.
HIGHS IN THE TEENS/LOWER 20S PER MULTI-GUIDANCE BLENDS...WHICH FITS
EXPECTED BL THERMAL PROGS/DIURNAL RESPONSE. CLOUD/LAKE SNOW TRENDS A
MUCH LOWER CONFIDENCE PORTION OF THE FORECAST. GUIDANCE INSISTS IN
SPIKE OF LOW LEVEL MOISTURE TODAY...ALTHOUGH BACKWARD RUN
TRAJECTORIES SHOW NO UPSTREAM LOW LEVEL MOISTURE SOURCE. COLD ENOUGH
AIRMASS AND ENOUGH OPEN WATER AREAS TO GET SOME DECENT LAKE
RESPONSE...ALTHOUGH HAVE SERIOUS DOUBTS ABOUT EXPECTED SYNOPTIC
MOISTURE HELP AND DEPTH OF CBL ON HIGH RES GUIDANCE. WILL KEEP
FLURRY MENTION FOR NOW OFF THE BIG WATERS...WITH EXPECTED DIURNAL
STCU RESPONSE UNDER COLD DOME LATER THIS MORNING AND AFTERNOON
GENERATING FLURRIES AREA-WIDE (MUCH LIKE WHAT WAS EXPERIENCED
YESTERDAY OVER SOUTHERN CANADA).
HIGH PRESSURE BUILDS OVERHEAD TONIGHT...WITH RESULTANT LIGHT WINDS
AND DEEP DRYING ENDING LAKE ACTIVITY THIS EVENING...WITH MAINLY
CLEAR TO PARTLY CLOUDY SKIES OVERNIGHT. ABOVE SHOULD RESULT IN A
REALLY GOOD NOCTURNAL TEMPERATURE RESPONSE...AND WITH SUCH A COLD
AIRMASS ALREADY IN PLACE...REALLY LIKE THE COLDER END OF THE
GUIDANCE SPECTRUM (MAV MOS). WILL EVEN UNDERCUT THESE A TAD...
RESULTING IN LOWS BY SUNRISE MONDAY RANGING FROM ZERO TO TEN
BELOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 300 AM EDT SUN MAR 23 2014
MONDAY AND TUESDAY...COLD AIR WILL HANG ON THRU THE FIRST PART OF
THE WORK WEEK (AT LEAST) AS PERSISTENT UPPER LEVEL TROUGHING HOLDS
OVER THE GREAT LAKES REGION. SURFACE HIGH CENTER SLIDES OVER
MICHIGAN BY MONDAY MORNING AND THEN SHIFTS EAST OF OUR STATE BY
MONDAY NIGHT AS A REINFORCING COLD FRONT SLIDES INTO THE WRN GREAT
LAKES. SNOW CHANCES WILL INCREASE MONDAY NIGHT INTO TUESDAY AS THIS
FEATURE AND ASSOCIATED MOISTURE APPROACH AND TRACK THRU OUR CWA.
MOISTURE IS LIMITED...AND MAIN LOW AND STRONGEST LIFT REMAIN WELL
NORTH OF MICHIGAN. HOWEVER...CHANCE POPS ARE STILL CERTAINLY
WARRANTED ALONG AND AHEAD OF THE COLD FRONT. EXPECTATION OF LIGHT
QPF SHOULD RESULT IN NEW SNOW AMOUNTS OF UP TO AN INCH FOR MONDAY
NIGHT AND UP TO ANOTHER INCH ON TUESDAY. FROPA BY TUESDAY EVENING
SHOULD BRING ALL PRECIP CHANCES TO AN END...WITH MAINLY DRY WEATHER
EXPECTED THRU TUESDAY NIGHT AS HIGH PRESSURE AND A REINFORCING SHOT
OF COLD AIR BUILD INTO MICHIGAN IN THE WAKE OF THE COLD FRONT. HIGH
TEMPS BOTH MONDAY AND TUESDAY WILL ONLY REACH INTO THE 20S...WITH
OVERNIGHT LOWS IN THE SINGLE DIGITS AND TEENS MONDAY NIGHT AND ONCE
AGAIN PLUMMETING BELOW ZERO TUESDAY NIGHT.
WEDNESDAY THRU SATURDAY...COLD AND DRY WEATHER WILL EXTEND INTO
WEDNESDAY WITH THE CANADIAN HIGH STILL FIRMLY IN CONTROL. OUR
ATTENTION THEN TURNS TO THE POTENTIAL FOR A STRONGER SYSTEM TO
IMPACT MICHIGAN BEGINNING WEDNESDAY NIGHT AND CONTINUING THRU
THURSDAY AND FRIDAY. LOW PRESSURE WILL DEEPEN TO THE LEE OF THE
ROCKIES IN THE CENTRAL PLAINS WEDNESDAY NIGHT AND HEAD NE INTO THE
WRN GREAT LAKES REGION BY THURSDAY NIGHT. LATEST ECMWF IS FURTHER
SOUTH WITH THE ORIGIN OF THE SURFACE LOW DEVELOPMENT EAST OF THE
ROCKIES...AND NOW TRACKS THE SURFACE LOW CENTER THRU LWR MICHIGAN ON
FRIDAY VS. THRU LAKE SUPERIOR PER PREVIOUS RUNS. STILL EXPECT WARMER
AIR AND DEEP MOISTURE WILL SURGE INTO THE WRN GREAT LAKES AHEAD OF
THE ASSOCIATED COLD FRONT...LIKELY TAPING INTO THE GULF OF MEXICO.
ALSO STILL EXPECT THE POTENTIAL OF MIXED PRECIP AND DESCENT QPF
GIVEN THE PROJECTED THERMAL AND MOISTURE PROFILES. POPS WILL
INCREASE WEDNESDAY NIGHT...WITH THE BEST CHANCES FOR PRECIP
DEVELOPING THURSDAY INTO THURSDAY NIGHT AS DEEP MOISTURE ADVECTS
INTO MICHIGAN AHEAD OF THE SURFACE LOW. PRECIP TYPE WILL BE A BIG
CHALLENGE...AND WILL REMAIN RATHER GENERIC FOR NOW. PRECIP SHOULD BE
GENERALLY ALL SNOW BOTH WEDNESDAY NIGHT AND THURSDAY NIGHT...WITH A
MIX OF RAIN AND SNOW DURING THURSDAY AND FRIDAY. PRECIP WILL COME TO
AN END BY FRIDAY NIGHT WITH DRY WEATHER EXPECTED AS WE HEAD INTO
NEXT WEEKEND. AFTER ONE LAST WELL BELOW NORMAL DAY WEDNESDAY WITH
HIGHS STILL MAINLY IN THE 20S...TEMPS WILL MODERATE TO NEAR NORMAL
LEVELS FOR THE REST OF THE WEEK WITH HIGHS IN THE MID 30S TO LOWER
40S FOR THURSDAY THRU SATURDAY. LOW TEMPS WILL GENERALLY BE IN THE
TEENS AND 20S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 209 PM EDT SUN MAR 23 2014
EXTENDED THE CHANCE FOR SNOW SHOWERS AT TVC/MBL/APN AS SNOW BANDS
HAVE BEEN ABLE TO CONTINUE THROUGH THE MORNING AND INTO THE
AFTERNOON. THIS WILL CONTINUE INTO THE EVENING, BUT WITH THE SFC
HIGH MOVING INTO THE REGION, WE SHOULD SEE THE WIND CEASE OR
SWITCH DIRECTIONS, AND STOP THE SNOW SHOWERS. JUST AS WE CLEAR
SOME TONIGHT, IT LOOKS LIKE IT WILL CLEAR OUT, EXPECTING MONDAY TO
START TO CLOUD UP AS THE NEXT SYSTEM MOVES INTO THE REGION.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JL
SYNOPSIS...MR
SHORT TERM...MSB
LONG TERM...MR
AVIATION...JL
AREA FORECAST DISCUSSION
NWS GAYLORD MI
209 PM EDT SUN MAR 23 2014
.SYNOPSIS...
ISSUED AT 300 AM EDT SUN MAR 23 2014
HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE GREAT LAKES REGION
THROUGH MONDAY. COLD AIR ASSOCIATED WITH THIS PATTERN WILL MAINTAIN
BELOW NORMAL TEMPERATURES ACROSS NORTHERN MICHIGAN INTO THE UPCOMING
WORK WEEK. THE NEXT SIGNIFICANT SYSTEM TO AFFECT THE GREAT LAKES
WILL ARRIVE DURING THE LAST HALF OF THE WEEK AS A STORM SYSTEM
ORGANIZES OVER THE PLAINS AND LIFTS INTO THE OHIO VALLEY. THIS
PATTERN WILL GENERATE ANOTHER ROUND OF EARLY SPRING SNOWS OVER
NORTHERN MICHIGAN WEDNESDAY NIGHT THROUGH FRIDAY.
&&
.UPDATE...
ISSUED AT 203 PM EDT SUN MAR 23 2014
PUSHED THE SNOW SHOWERS INLAND BASED ON THE SATELLITE AND RADAR
IMAGES. THE DRY AIR DOESN`T SEEM TO AFFECTING THE BANDS MUCH AS
THE OPEN WATER ON THE WEST SIDE OF LAKE MICHIGAN IS. THERE IS A
SHARP LINE OF WHERE THE SNOW SHOWERS STOP NORTH OF A LINE FROM
KMGN TO KOSC. ALTHOUGH, THERE HAS BEEN SOME DEVELOPMENT FROM LAKE
SUPERIOR TO AROUND KSLH/KPZQ/KAPN IN NE LOWER. WILL WATCH THESE
AND SEE IF THEY BECOME MORE THAN FLURRIES OVER THE NEXT COUPLE OF
HOURS.
UPDATE ISSUED AT 1124 AM EDT SUN MAR 23 2014
UPDATED THE GRIDS EARLIER, BUT MAY HAVE TO MAKE MORE CHANGES AS
THE LAKE STREAMERS ARE CONTINUING TO DEPOSIT LIGHT SNOW SHOWERS
INTO NW LOWER, MAINLY WEST OF US-131 AND SOUTH OF M-32. WHILE MOST
PLACES ARE GETTING FLURRIES NEAR THESE BANDS, THERE AREA SOME
PLACES THAT WILL GET MINOR TO LIGHT ACCUMULATIONS.
UPDATE ISSUED AT 645 AM EDT SUN MAR 23 2014
LAKE EFFECT FLURRIES HAVE ORGANIZED AND DEVELOPED INTO LAKE EFFECT
SNOW BANDS STREAMING SOUTHWARD ALONG THE LENGTH OF GRAND TRAVERSE
BAY INTO THE TVC AREA. LATEST OBS FROM MBL ALSO SUGGEST SNOW
SHOWER ACTIVITY IN THIS REGION WITH VSBYS FALLING TO 3SM. HAVE
INCREASED POPS TO SCATTERED MEASURABLE SNOW SHOWERS FOR OUR FAR SW
CWA EARLY THIS MORNING BEFORE DIURNAL MIXING/HEATING LENDS TO
DISORGANIZATION OF LAKE BANDING. ANY NEW SNOW ACCUMULATION WILL BE
WELL UNDER AN INCH. REST OF OUR CWA WILL SEE SCT/BKN LAKE CLOUDS
AND FLURRIES THRU THE DAY. ANOTHER COLD DAY IS IN STORE FOR THE
NORTHWOODS...WITH AFTERNOON HIGHS ONLY REACHING INTO THE UPPER
TEENS AND LOWER 20S.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 300 AM EDT SUN MAR 23 2014
...RIDICULOUSLY COLD FOR THE LATTER HALF OF MARCH!...
HIGH IMPACT WEATHER POTENTIAL: NONE.
OVERVIEW: FLOOD GATES TO ANOTHER ROUND OF ARCTIC AIR HAVE
OPENED...COURTESY OF DEEP NORTHWEST FLOW ON FRONT SIDE OF
SPRAWLING HIGH PRESSURE BUILDING THROUGH THE NORTHERN HIGH PLAINS.
LATEST HIGH RES RUC GUIDANCE HAS -20C H8 BUILDING INTO THE
NORTHERN PARTS OF OUR AREA AT THIS EARLY HOUR...NEARLY 2 STANDARD
DEVIATIONS BELOW NORMAL FOR THIS TIME OF YEAR (WAS ALREADY -18C ON
LOCAL 00Z SOUNDING). IMPRESSIVE COLD INDEED! REMNANT PRESSURE
GRADIENT/ASSOCIATED WINDS HAVE KEPT SURFACE TEMPERATURES FROM
TANKING TO THEIR FULL POTENTIAL GIVEN MAINLY CLEAR SKIES AND AN
UNSEASONABLY COLD AIRMASS. STILL...CURRENT READINGS FALLING INTO
AND THROUGH THE SINGLE DIGITS COLD ENOUGH FOR SURE...AND ARE A
GOOD 10 TO 15 DEGREES BELOW NORMAL FOR THIS DATE. DESPITE THESE
COLD CONDITIONS AND OPEN POCKETS OF GREAT LAKES WATER...DRY
AIRMASS AND LOW INVERSION HEIGHTS HAVE TAKEN THEIR COLLECTIVE TOLL
ON LAKE RESPONSE...WITH JUST A FEW LINGERING FLURRIES UNDER NNW
FLOW STCU DECK.
PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE/CLOUD TRENDS AND
LIGHT LAKE EFFECT SNOW POTENTIAL.
FORECAST DETAILS: HIGH CONFIDENCE PORTION OF THE FORECAST CENTERS ON
TEMPERATURES...WHICH WILL NO DOUBT REMAIN ON THE FRIGID SIDE. LATE
MARCH DIURNAL TREND WILL TRY ITS BEST TO MODIFY THINGS A TOUCH
TODAY...BUT WILL LARGELY LOSE THE BATTLE GIVEN -20C H8 AIR OVERHEAD.
HIGHS IN THE TEENS/LOWER 20S PER MULTI-GUIDANCE BLENDS...WHICH FITS
EXPECTED BL THERMAL PROGS/DIURNAL RESPONSE. CLOUD/LAKE SNOW TRENDS A
MUCH LOWER CONFIDENCE PORTION OF THE FORECAST. GUIDANCE INSISTS IN
SPIKE OF LOW LEVEL MOISTURE TODAY...ALTHOUGH BACKWARD RUN
TRAJECTORIES SHOW NO UPSTREAM LOW LEVEL MOISTURE SOURCE. COLD ENOUGH
AIRMASS AND ENOUGH OPEN WATER AREAS TO GET SOME DECENT LAKE
RESPONSE...ALTHOUGH HAVE SERIOUS DOUBTS ABOUT EXPECTED SYNOPTIC
MOISTURE HELP AND DEPTH OF CBL ON HIGH RES GUIDANCE. WILL KEEP
FLURRY MENTION FOR NOW OFF THE BIG WATERS...WITH EXPECTED DIURNAL
STCU RESPONSE UNDER COLD DOME LATER THIS MORNING AND AFTERNOON
GENERATING FLURRIES AREA-WIDE (MUCH LIKE WHAT WAS EXPERIENCED
YESTERDAY OVER SOUTHERN CANADA).
HIGH PRESSURE BUILDS OVERHEAD TONIGHT...WITH RESULTANT LIGHT WINDS
AND DEEP DRYING ENDING LAKE ACTIVITY THIS EVENING...WITH MAINLY
CLEAR TO PARTLY CLOUDY SKIES OVERNIGHT. ABOVE SHOULD RESULT IN A
REALLY GOOD NOCTURNAL TEMPERATURE RESPONSE...AND WITH SUCH A COLD
AIRMASS ALREADY IN PLACE...REALLY LIKE THE COLDER END OF THE
GUIDANCE SPECTRUM (MAV MOS). WILL EVEN UNDERCUT THESE A TAD...
RESULTING IN LOWS BY SUNRISE MONDAY RANGING FROM ZERO TO TEN
BELOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 300 AM EDT SUN MAR 23 2014
MONDAY AND TUESDAY...COLD AIR WILL HANG ON THRU THE FIRST PART OF
THE WORK WEEK (AT LEAST) AS PERSISTENT UPPER LEVEL TROUGHING HOLDS
OVER THE GREAT LAKES REGION. SURFACE HIGH CENTER SLIDES OVER
MICHIGAN BY MONDAY MORNING AND THEN SHIFTS EAST OF OUR STATE BY
MONDAY NIGHT AS A REINFORCING COLD FRONT SLIDES INTO THE WRN GREAT
LAKES. SNOW CHANCES WILL INCREASE MONDAY NIGHT INTO TUESDAY AS THIS
FEATURE AND ASSOCIATED MOISTURE APPROACH AND TRACK THRU OUR CWA.
MOISTURE IS LIMITED...AND MAIN LOW AND STRONGEST LIFT REMAIN WELL
NORTH OF MICHIGAN. HOWEVER...CHANCE POPS ARE STILL CERTAINLY
WARRANTED ALONG AND AHEAD OF THE COLD FRONT. EXPECTATION OF LIGHT
QPF SHOULD RESULT IN NEW SNOW AMOUNTS OF UP TO AN INCH FOR MONDAY
NIGHT AND UP TO ANOTHER INCH ON TUESDAY. FROPA BY TUESDAY EVENING
SHOULD BRING ALL PRECIP CHANCES TO AN END...WITH MAINLY DRY WEATHER
EXPECTED THRU TUESDAY NIGHT AS HIGH PRESSURE AND A REINFORCING SHOT
OF COLD AIR BUILD INTO MICHIGAN IN THE WAKE OF THE COLD FRONT. HIGH
TEMPS BOTH MONDAY AND TUESDAY WILL ONLY REACH INTO THE 20S...WITH
OVERNIGHT LOWS IN THE SINGLE DIGITS AND TEENS MONDAY NIGHT AND ONCE
AGAIN PLUMMETING BELOW ZERO TUESDAY NIGHT.
WEDNESDAY THRU SATURDAY...COLD AND DRY WEATHER WILL EXTEND INTO
WEDNESDAY WITH THE CANADIAN HIGH STILL FIRMLY IN CONTROL. OUR
ATTENTION THEN TURNS TO THE POTENTIAL FOR A STRONGER SYSTEM TO
IMPACT MICHIGAN BEGINNING WEDNESDAY NIGHT AND CONTINUING THRU
THURSDAY AND FRIDAY. LOW PRESSURE WILL DEEPEN TO THE LEE OF THE
ROCKIES IN THE CENTRAL PLAINS WEDNESDAY NIGHT AND HEAD NE INTO THE
WRN GREAT LAKES REGION BY THURSDAY NIGHT. LATEST ECMWF IS FURTHER
SOUTH WITH THE ORIGIN OF THE SURFACE LOW DEVELOPMENT EAST OF THE
ROCKIES...AND NOW TRACKS THE SURFACE LOW CENTER THRU LWR MICHIGAN ON
FRIDAY VS. THRU LAKE SUPERIOR PER PREVIOUS RUNS. STILL EXPECT WARMER
AIR AND DEEP MOISTURE WILL SURGE INTO THE WRN GREAT LAKES AHEAD OF
THE ASSOCIATED COLD FRONT...LIKELY TAPING INTO THE GULF OF MEXICO.
ALSO STILL EXPECT THE POTENTIAL OF MIXED PRECIP AND DESCENT QPF
GIVEN THE PROJECTED THERMAL AND MOISTURE PROFILES. POPS WILL
INCREASE WEDNESDAY NIGHT...WITH THE BEST CHANCES FOR PRECIP
DEVELOPING THURSDAY INTO THURSDAY NIGHT AS DEEP MOISTURE ADVECTS
INTO MICHIGAN AHEAD OF THE SURFACE LOW. PRECIP TYPE WILL BE A BIG
CHALLENGE...AND WILL REMAIN RATHER GENERIC FOR NOW. PRECIP SHOULD BE
GENERALLY ALL SNOW BOTH WEDNESDAY NIGHT AND THURSDAY NIGHT...WITH A
MIX OF RAIN AND SNOW DURING THURSDAY AND FRIDAY. PRECIP WILL COME TO
AN END BY FRIDAY NIGHT WITH DRY WEATHER EXPECTED AS WE HEAD INTO
NEXT WEEKEND. AFTER ONE LAST WELL BELOW NORMAL DAY WEDNESDAY WITH
HIGHS STILL MAINLY IN THE 20S...TEMPS WILL MODERATE TO NEAR NORMAL
LEVELS FOR THE REST OF THE WEEK WITH HIGHS IN THE MID 30S TO LOWER
40S FOR THURSDAY THRU SATURDAY. LOW TEMPS WILL GENERALLY BE IN THE
TEENS AND 20S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 645 AM EDT SUN MAR 23 2014
SCATTERED LIGHT LAKE EFFECT SNOW SHOWERS AND LAKE CLOUDS WILL
IMPACT PORTIONS OF NRN LWR MICHIGAN TODAY INTO THIS EVENING...
ESPECIALLY ALONG THE LAKE MICHIGAN SHORELINE NEAR TVC AND MBL.
OVERALL CONDITIONS WILL REMAIN LOW VFR/HIGH MVFR THRU TODAY...WITH
LAKE CLOUDS BECOME SCATTERED TONIGHT AS THE SURFACE HIGH CENTER
MOVES OVERHEAD. NW WINDS BELOW 10 KTS THIS MORNING WILL STRENGTHEN
TO GUST OF 20 KTS THIS AFTERNOON...AND WILL AGAIN DIMINISH TO
BELOW 10 KTS WITH SUNSET THIS EVENING.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JL
SYNOPSIS...MR
SHORT TERM...MSB
LONG TERM...MR
AVIATION...MR
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1129 AM EDT SUN MAR 23 2014
.SYNOPSIS...
ISSUED AT 300 AM EDT SUN MAR 23 2014
HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE GREAT LAKES REGION
THROUGH MONDAY. COLD AIR ASSOCIATED WITH THIS PATTERN WILL MAINTAIN
BELOW NORMAL TEMPERATURES ACROSS NORTHERN MICHIGAN INTO THE UPCOMING
WORK WEEK. THE NEXT SIGNIFICANT SYSTEM TO AFFECT THE GREAT LAKES
WILL ARRIVE DURING THE LAST HALF OF THE WEEK AS A STORM SYSTEM
ORGANIZES OVER THE PLAINS AND LIFTS INTO THE OHIO VALLEY. THIS
PATTERN WILL GENERATE ANOTHER ROUND OF EARLY SPRING SNOWS OVER
NORTHERN MICHIGAN WEDNESDAY NIGHT THROUGH FRIDAY.
&&
.UPDATE...
ISSUED AT 1124 AM EDT SUN MAR 23 2014
UPDATED THE GRIDS EARLIER, BUT MAY HAVE TO MAKE MORE CHANGES AS
THE LAKE STREAMERS ARE CONTINUING TO DEPOSIT LIGHT SNOW SHOWERS
INTO NW LOWER, MAINLY WEST OF US-131 AND SOUTH OF M-32. WHILE MOST
PLACES ARE GETTING FLURRIES NEAR THESE BANDS, THERE AREA SOME
PLACES THAT WILL GET MINOR TO LIGHT ACCUMULATIONS.
UPDATE ISSUED AT 645 AM EDT SUN MAR 23 2014
LAKE EFFECT FLURRIES HAVE ORGANIZED AND DEVELOPED INTO LAKE EFFECT
SNOW BANDS STREAMING SOUTHWARD ALONG THE LENGTH OF GRAND TRAVERSE
BAY INTO THE TVC AREA. LATEST OBS FROM MBL ALSO SUGGEST SNOW
SHOWER ACTIVITY IN THIS REGION WITH VSBYS FALLING TO 3SM. HAVE
INCREASED POPS TO SCATTERED MEASURABLE SNOW SHOWERS FOR OUR FAR SW
CWA EARLY THIS MORNING BEFORE DIURNAL MIXING/HEATING LENDS TO
DISORGANIZATION OF LAKE BANDING. ANY NEW SNOW ACCUMULATION WILL BE
WELL UNDER AN INCH. REST OF OUR CWA WILL SEE SCT/BKN LAKE CLOUDS
AND FLURRIES THRU THE DAY. ANOTHER COLD DAY IS IN STORE FOR THE
NORTHWOODS...WITH AFTERNOON HIGHS ONLY REACHING INTO THE UPPER
TEENS AND LOWER 20S.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 300 AM EDT SUN MAR 23 2014
...RIDICULOUSLY COLD FOR THE LATTER HALF OF MARCH!...
HIGH IMPACT WEATHER POTENTIAL: NONE.
OVERVIEW: FLOOD GATES TO ANOTHER ROUND OF ARCTIC AIR HAVE
OPENED...COURTESY OF DEEP NORTHWEST FLOW ON FRONT SIDE OF
SPRAWLING HIGH PRESSURE BUILDING THROUGH THE NORTHERN HIGH PLAINS.
LATEST HIGH RES RUC GUIDANCE HAS -20C H8 BUILDING INTO THE
NORTHERN PARTS OF OUR AREA AT THIS EARLY HOUR...NEARLY 2 STANDARD
DEVIATIONS BELOW NORMAL FOR THIS TIME OF YEAR (WAS ALREADY -18C ON
LOCAL 00Z SOUNDING). IMPRESSIVE COLD INDEED! REMNANT PRESSURE
GRADIENT/ASSOCIATED WINDS HAVE KEPT SURFACE TEMPERATURES FROM
TANKING TO THEIR FULL POTENTIAL GIVEN MAINLY CLEAR SKIES AND AN
UNSEASONABLY COLD AIRMASS. STILL...CURRENT READINGS FALLING INTO
AND THROUGH THE SINGLE DIGITS COLD ENOUGH FOR SURE...AND ARE A
GOOD 10 TO 15 DEGREES BELOW NORMAL FOR THIS DATE. DESPITE THESE
COLD CONDITIONS AND OPEN POCKETS OF GREAT LAKES WATER...DRY
AIRMASS AND LOW INVERSION HEIGHTS HAVE TAKEN THEIR COLLECTIVE TOLL
ON LAKE RESPONSE...WITH JUST A FEW LINGERING FLURRIES UNDER NNW
FLOW STCU DECK.
PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE/CLOUD TRENDS AND
LIGHT LAKE EFFECT SNOW POTENTIAL.
FORECAST DETAILS: HIGH CONFIDENCE PORTION OF THE FORECAST CENTERS ON
TEMPERATURES...WHICH WILL NO DOUBT REMAIN ON THE FRIGID SIDE. LATE
MARCH DIURNAL TREND WILL TRY ITS BEST TO MODIFY THINGS A TOUCH
TODAY...BUT WILL LARGELY LOSE THE BATTLE GIVEN -20C H8 AIR OVERHEAD.
HIGHS IN THE TEENS/LOWER 20S PER MULTI-GUIDANCE BLENDS...WHICH FITS
EXPECTED BL THERMAL PROGS/DIURNAL RESPONSE. CLOUD/LAKE SNOW TRENDS A
MUCH LOWER CONFIDENCE PORTION OF THE FORECAST. GUIDANCE INSISTS IN
SPIKE OF LOW LEVEL MOISTURE TODAY...ALTHOUGH BACKWARD RUN
TRAJECTORIES SHOW NO UPSTREAM LOW LEVEL MOISTURE SOURCE. COLD ENOUGH
AIRMASS AND ENOUGH OPEN WATER AREAS TO GET SOME DECENT LAKE
RESPONSE...ALTHOUGH HAVE SERIOUS DOUBTS ABOUT EXPECTED SYNOPTIC
MOISTURE HELP AND DEPTH OF CBL ON HIGH RES GUIDANCE. WILL KEEP
FLURRY MENTION FOR NOW OFF THE BIG WATERS...WITH EXPECTED DIURNAL
STCU RESPONSE UNDER COLD DOME LATER THIS MORNING AND AFTERNOON
GENERATING FLURRIES AREA-WIDE (MUCH LIKE WHAT WAS EXPERIENCED
YESTERDAY OVER SOUTHERN CANADA).
HIGH PRESSURE BUILDS OVERHEAD TONIGHT...WITH RESULTANT LIGHT WINDS
AND DEEP DRYING ENDING LAKE ACTIVITY THIS EVENING...WITH MAINLY
CLEAR TO PARTLY CLOUDY SKIES OVERNIGHT. ABOVE SHOULD RESULT IN A
REALLY GOOD NOCTURNAL TEMPERATURE RESPONSE...AND WITH SUCH A COLD
AIRMASS ALREADY IN PLACE...REALLY LIKE THE COLDER END OF THE
GUIDANCE SPECTRUM (MAVMOS). WILL EVEN UNDERCUT THESE A TAD...
RESULTING IN LOWS BY SUNRISE MONDAY RANGING FROM ZERO TO TEN
BELOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 300 AM EDT SUN MAR 23 2014
MONDAY AND TUESDAY...COLD AIR WILL HANG ON THRU THE FIRST PART OF
THE WORK WEEK (AT LEAST) AS PERSISTENT UPPER LEVEL TROUGHING HOLDS
OVER THE GREAT LAKES REGION. SURFACE HIGH CENTER SLIDES OVER
MICHIGAN BY MONDAY MORNING AND THEN SHIFTS EAST OF OUR STATE BY
MONDAY NIGHT AS A REINFORCING COLD FRONT SLIDES INTO THE WRN GREAT
LAKES. SNOW CHANCES WILL INCREASE MONDAY NIGHT INTO TUESDAY AS THIS
FEATURE AND ASSOCIATED MOISTURE APPROACH AND TRACK THRU OUR CWA.
MOISTURE IS LIMITED...AND MAIN LOW AND STRONGEST LIFT REMAIN WELL
NORTH OF MICHIGAN. HOWEVER...CHANCE POPS ARE STILL CERTAINLY
WARRANTED ALONG AND AHEAD OF THE COLD FRONT. EXPECTATION OF LIGHT
QPF SHOULD RESULT IN NEW SNOW AMOUNTS OF UP TO AN INCH FOR MONDAY
NIGHT AND UP TO ANOTHER INCH ON TUESDAY. FROPA BY TUESDAY EVENING
SHOULD BRING ALL PRECIP CHANCES TO AN END...WITH MAINLY DRY WEATHER
EXPECTED THRU TUESDAY NIGHT AS HIGH PRESSURE AND A REINFORCING SHOT
OF COLD AIR BUILD INTO MICHIGAN IN THE WAKE OF THE COLD FRONT. HIGH
TEMPS BOTH MONDAY AND TUESDAY WILL ONLY REACH INTO THE 20S...WITH
OVERNIGHT LOWS IN THE SINGLE DIGITS AND TEENS MONDAY NIGHT AND ONCE
AGAIN PLUMMETING BELOW ZERO TUESDAY NIGHT.
WEDNESDAY THRU SATURDAY...COLD AND DRY WEATHER WILL EXTEND INTO
WEDNESDAY WITH THE CANADIAN HIGH STILL FIRMLY IN CONTROL. OUR
ATTENTION THEN TURNS TO THE POTENTIAL FOR A STRONGER SYSTEM TO
IMPACT MICHIGAN BEGINNING WEDNESDAY NIGHT AND CONTINUING THRU
THURSDAY AND FRIDAY. LOW PRESSURE WILL DEEPEN TO THE LEE OF THE
ROCKIES IN THE CENTRAL PLAINS WEDNESDAY NIGHT AND HEAD NE INTO THE
WRN GREAT LAKES REGION BY THURSDAY NIGHT. LATEST ECMWF IS FURTHER
SOUTH WITH THE ORIGIN OF THE SURFACE LOW DEVELOPMENT EAST OF THE
ROCKIES...AND NOW TRACKS THE SURFACE LOW CENTER THRU LWR MICHIGAN ON
FRIDAY VS. THRU LAKE SUPERIOR PER PREVIOUS RUNS. STILL EXPECT WARMER
AIR AND DEEP MOISTURE WILL SURGE INTO THE WRN GREAT LAKES AHEAD OF
THE ASSOCIATED COLD FRONT...LIKELY TAPING INTO THE GULF OF MEXICO.
ALSO STILL EXPECT THE POTENTIAL OF MIXED PRECIP AND DESCENT QPF
GIVEN THE PROJECTED THERMAL AND MOISTURE PROFILES. POPS WILL
INCREASE WEDNESDAY NIGHT...WITH THE BEST CHANCES FOR PRECIP
DEVELOPING THURSDAY INTO THURSDAY NIGHT AS DEEP MOISTURE ADVECTS
INTO MICHIGAN AHEAD OF THE SURFACE LOW. PRECIP TYPE WILL BE A BIG
CHALLENGE...AND WILL REMAIN RATHER GENERIC FOR NOW. PRECIP SHOULD BE
GENERALLY ALL SNOW BOTH WEDNESDAY NIGHT AND THURSDAY NIGHT...WITH A
MIX OF RAIN AND SNOW DURING THURSDAY AND FRIDAY. PRECIP WILL COME TO
AN END BY FRIDAY NIGHT WITH DRY WEATHER EXPECTED AS WE HEAD INTO
NEXT WEEKEND. AFTER ONE LAST WELL BELOW NORMAL DAY WEDNESDAY WITH
HIGHS STILL MAINLY IN THE 20S...TEMPS WILL MODERATE TO NEAR NORMAL
LEVELS FOR THE REST OF THE WEEK WITH HIGHS IN THE MID 30S TO LOWER
40S FOR THURSDAY THRU SATURDAY. LOW TEMPS WILL GENERALLY BE IN THE
TEENS AND 20S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 645 AM EDT SUN MAR 23 2014
SCATTERED LIGHT LAKE EFFECT SNOW SHOWERS AND LAKE CLOUDS WILL
IMPACT PORTIONS OF NRN LWR MICHIGAN TODAY INTO THIS EVENING...
ESPECIALLY ALONG THE LAKE MICHIGAN SHORELINE NEAR TVC AND MBL.
OVERALL CONDITIONS WILL REMAIN LOW VFR/HIGH MVFR THRU TODAY...WITH
LAKE CLOUDS BECOME SCATTERED TONIGHT AS THE SURFACE HIGH CENTER
MOVES OVERHEAD. NW WINDS BELOW 10 KTS THIS MORNING WILL STRENGTHEN
TO GUST OF 20 KTS THIS AFTERNOON...AND WILL AGAIN DIMINISH TO
BELOW 10 KTS WITH SUNSET THIS EVENING.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JL
SYNOPSIS...MR
SHORT TERM...MSB
LONG TERM...MR
AVIATION...MR
AREA FORECAST DISCUSSION
NWS GAYLORD MI
300 AM EDT SUN MAR 23 2014
.SYNOPSIS...
ISSUED AT 300 AM EDT SUN MAR 23 2014
HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE GREAT LAKES REGION
THROUGH MONDAY. COLD AIR ASSOCIATED WITH THIS PATTERN WILL MAINTAIN
BELOW NORMAL TEMPERATURES ACROSS NORTHERN MICHIGAN INTO THE UPCOMING
WORK WEEK. THE NEXT SIGNIFICANT SYSTEM TO AFFECT THE GREAT LAKES
WILL ARRIVE DURING THE LAST HALF OF THE WEEK AS A STORM SYSTEM
ORGANIZES OVER THE PLAINS AND LIFTS INTO THE OHIO VALLEY. THIS
PATTERN WILL GENERATE ANOTHER ROUND OF EARLY SPRING SNOWS OVER
NORTHERN MICHIGAN WEDNESDAY NIGHT THROUGH FRIDAY.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 300 AM EDT SUN MAR 23 2014
...RIDICULOUSLY COLD FOR THE LATTER HALF OF MARCH!...
HIGH IMPACT WEATHER POTENTIAL: NONE.
OVERVIEW: FLOOD GATES TO ANOTHER ROUND OF ARCTIC AIR HAVE
OPENED...COURTESY OF DEEP NORTHWEST FLOW ON FRONT SIDE OF
SPRAWLING HIGH PRESSURE BUILDING THROUGH THE NORTHERN HIGH PLAINS.
LATEST HIGH RES RUC GUIDANCE HAS -20C H8 BUILDING INTO THE
NORTHERN PARTS OF OUR AREA AT THIS EARLY HOUR...NEARLY 2 STANDARD
DEVIATIONS BELOW NORMAL FOR THIS TIME OF YEAR (WAS ALREADY -18C ON
LOCAL 00Z SOUNDING). IMPRESSIVE COLD INDEED! REMNANT PRESSURE
GRADIENT/ASSOCIATED WINDS HAVE KEPT SURFACE TEMPERATURES FROM
TANKING TO THEIR FULL POTENTIAL GIVEN MAINLY CLEAR SKIES AND AN
UNSEASONABLY COLD AIRMASS. STILL...CURRENT READINGS FALLING INTO
AND THROUGH THE SINGLE DIGITS COLD ENOUGH FOR SURE...AND ARE A
GOOD 10 TO 15 DEGREES BELOW NORMAL FOR THIS DATE. DESPITE THESE
COLD CONDITIONS AND OPEN POCKETS OF GREAT LAKES WATER...DRY
AIRMASS AND LOW INVERSION HEIGHTS HAVE TAKEN THEIR COLLECTIVE TOLL
ON LAKE RESPONSE...WITH JUST A FEW LINGERING FLURRIES UNDER NNW
FLOW STCU DECK.
PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE/CLOUD TRENDS AND
LIGHT LAKE EFFECT SNOW POTENTIAL.
FORECAST DETAILS: HIGH CONFIDENCE PORTION OF THE FORECAST CENTERS ON
TEMPERATURES...WHICH WILL NO DOUBT REMAIN ON THE FRIGID SIDE. LATE
MARCH DIURNAL TREND WILL TRY ITS BEST TO MODIFY THINGS A TOUCH
TODAY...BUT WILL LARGELY LOSE THE BATTLE GIVEN -20C H8 AIR OVERHEAD.
HIGHS IN THE TEENS/LOWER 20S PER MULTI-GUIDANCE BLENDS...WHICH FITS
EXPECTED BL THERMAL PROGS/DIURNAL RESPONSE. CLOUD/LAKE SNOW TRENDS A
MUCH LOWER CONFIDENCE PORTION OF THE FORECAST. GUIDANCE INSISTS IN
SPIKE OF LOW LEVEL MOISTURE TODAY...ALTHOUGH BACKWARD RUN
TRAJECTORIES SHOW NO UPSTREAM LOW LEVEL MOISTURE SOURCE. COLD ENOUGH
AIRMASS AND ENOUGH OPEN WATER AREAS TO GET SOME DECENT LAKE
RESPONSE...ALTHOUGH HAVE SERIOUS DOUBTS ABOUT EXPECTED SYNOPTIC
MOISTURE HELP AND DEPTH OF CBL ON HIGH RES GUIDANCE. WILL KEEP
FLURRY MENTION FOR NOW OFF THE BIG WATERS...WITH EXPECTED DIURNAL
STCU RESPONSE UNDER COLD DOME LATER THIS MORNING AND AFTERNOON
GENERATING FLURRIES AREA-WIDE (MUCH LIKE WHAT WAS EXPERIENCED
YESTERDAY OVER SOUTHERN CANADA).
HIGH PRESSURE BUILDS OVERHEAD TONIGHT...WITH RESULTANT LIGHT WINDS
AND DEEP DRYING ENDING LAKE ACTIVITY THIS EVENING...WITH MAINLY
CLEAR TO PARTLY CLOUDY SKIES OVERNIGHT. ABOVE SHOULD RESULT IN A
REALLY GOOD NOCTURNAL TEMPERATURE RESPONSE...AND WITH SUCH A COLD
AIRMASS ALREADY IN PLACE...REALLY LIKE THE COLDER END OF THE
GUIDANCE SPECTRUM (MAVMOS). WILL EVEN UNDERCUT THESE A TAD...
RESULTING IN LOWS BY SUNRISE MONDAY RANGING FROM ZERO TO TEN
BELOW.
&&
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 300 AM EDT SUN MAR 23 2014
MONDAY AND TUESDAY...COLD AIR WILL HANG ON THRU THE FIRST PART OF
THE WORK WEEK (AT LEAST) AS PERSISTENT UPPER LEVEL TROUGHING HOLDS
OVER THE GREAT LAKES REGION. SURFACE HIGH CENTER SLIDES OVER
MICHIGAN BY MONDAY MORNING AND THEN SHIFTS EAST OF OUR STATE BY
MONDAY NIGHT AS A REINFORCING COLD FRONT SLIDES INTO THE WRN GREAT
LAKES. SNOW CHANCES WILL INCREASE MONDAY NIGHT INTO TUESDAY AS THIS
FEATURE AND ASSOCIATED MOISTURE APPROACH AND TRACK THRU OUR CWA.
MOISTURE IS LIMITED...AND MAIN LOW AND STRONGEST LIFT REMAIN WELL
NORTH OF MICHIGAN. HOWEVER...CHANCE POPS ARE STILL CERTAINLY
WARRANTED ALONG AND AHEAD OF THE COLD FRONT. EXPECTATION OF LIGHT
QPF SHOULD RESULT IN NEW SNOW AMOUNTS OF UP TO AN INCH FOR MONDAY
NIGHT AND UP TO ANOTHER INCH ON TUESDAY. FROPA BY TUESDAY EVENING
SHOULD BRING ALL PRECIP CHANCES TO AN END...WITH MAINLY DRY WEATHER
EXPECTED THRU TUESDAY NIGHT AS HIGH PRESSURE AND A REINFORCING SHOT
OF COLD AIR BUILD INTO MICHIGAN IN THE WAKE OF THE COLD FRONT. HIGH
TEMPS BOTH MONDAY AND TUESDAY WILL ONLY REACH INTO THE 20S...WITH
OVERNIGHT LOWS IN THE SINGLE DIGITS AND TEENS MONDAY NIGHT AND ONCE
AGAIN PLUMMETING BELOW ZERO TUESDAY NIGHT.
WEDNESDAY THRU SATURDAY...COLD AND DRY WEATHER WILL EXTEND INTO
WEDNESDAY WITH THE CANADIAN HIGH STILL FIRMLY IN CONTROL. OUR
ATTENTION THEN TURNS TO THE POTENTIAL FOR A STRONGER SYSTEM TO
IMPACT MICHIGAN BEGINNING WEDNESDAY NIGHT AND CONTINUING THRU
THURSDAY AND FRIDAY. LOW PRESSURE WILL DEEPEN TO THE LEE OF THE
ROCKIES IN THE CENTRAL PLAINS WEDNESDAY NIGHT AND HEAD NE INTO THE
WRN GREAT LAKES REGION BY THURSDAY NIGHT. LATEST ECMWF IS FURTHER
SOUTH WITH THE ORIGIN OF THE SURFACE LOW DEVELOPMENT EAST OF THE
ROCKIES...AND NOW TRACKS THE SURFACE LOW CENTER THRU LWR MICHIGAN ON
FRIDAY VS. THRU LAKE SUPERIOR PER PREVIOUS RUNS. STILL EXPECT WARMER
AIR AND DEEP MOISTURE WILL SURGE INTO THE WRN GREAT LAKES AHEAD OF
THE ASSOCIATED COLD FRONT...LIKELY TAPING INTO THE GULF OF MEXICO.
ALSO STILL EXPECT THE POTENTIAL OF MIXED PRECIP AND DESCENT QPF
GIVEN THE PROJECTED THERMAL AND MOISTURE PROFILES. POPS WILL
INCREASE WEDNESDAY NIGHT...WITH THE BEST CHANCES FOR PRECIP
DEVELOPING THURSDAY INTO THURSDAY NIGHT AS DEEP MOISTURE ADVECTS
INTO MICHIGAN AHEAD OF THE SURFACE LOW. PRECIP TYPE WILL BE A BIG
CHALLENGE...AND WILL REMAIN RATHER GENERIC FOR NOW. PRECIP SHOULD BE
GENERALLY ALL SNOW BOTH WEDNESDAY NIGHT AND THURSDAY NIGHT...WITH A
MIX OF RAIN AND SNOW DURING THURSDAY AND FRIDAY. PRECIP WILL COME TO
AN END BY FRIDAY NIGHT WITH DRY WEATHER EXPECTED AS WE HEAD INTO
NEXT WEEKEND. AFTER ONE LAST WELL BELOW NORMAL DAY WEDNESDAY WITH
HIGHS STILL MAINLY IN THE 20S...TEMPS WILL MODERATE TO NEAR NORMAL
LEVELS FOR THE REST OF THE WEEK WITH HIGHS IN THE MID 30S TO LOWER
40S FOR THURSDAY THRU SATURDAY. LOW TEMPS WILL GENERALLY BE IN THE
TEENS AND 20S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 132 AM EDT SUN MAR 23 2014
SOME MVFR CIG RESTRICTIONS AT TIMES...BUT MOSTLY VFR.
COLD AIR IS ONCE AGAIN SPILLING INTO THE NORTHERN LAKES
REGION...AHEAD OF HIGH PRESSURE IN THE NORTHERN PLAINS. COLD NW
WINDS WILL RESULT IN OCCASIONAL LAKE EFFECT CLOUD COVER...AND CIGS
WILL DIP INTO MVFR TERRITORY AT TIMES. COULD ALSO BE A FEW
FLURRIES/-SHSN IN THE TVC AREA.
NW WINDS THRU THE FORECAST. THESE WILL BE A BIT GUSTY SUNDAY
AFTERNOON...BUT NOT AS MUCH AS SATURDAY.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
SYNOPSIS...MR
SHORT TERM...MSB
LONG TERM...MR
AVIATION...JZ
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
928 AM MDT SUN MAR 23 2014
.UPDATE...
GOING FORECAST LOOKS IN REAL GOOD SHAPE AND ONLY MADE MINOR
ADJUSTMENTS. A SHORTWAVE TROUGH WAS MOVING INTO NORTHWEST MONTANA
THIS MORNING AND WILL SHIFT SOUTHEAST ACROSS THE FORECAST AREA
TODAY. THIS SYSTEM WILL GENERATE SNOW SHOWERS THROUGH THE DAY AS
IT PULLS COLDER AIR DOWN FROM CANADA. THIS COLD AIR INTRUSION WILL
ADD AN UPSLOPE COMPONENT TO MIX AND ENHANCE THE ASCENT ALONG THE
FOOTHILLS. THIS COVERED WELL IN GOING FORECAST. INSTABILITY WILL
PLAY A ROLE IN SNOW RATES AND ALLOW FOR PERIODS OF MODERATE SNOW
TODAY...ESPECIALLY ALONG THE FOOTHILLS THIS AFTERNOON AND EVENING.
WARM GROUND AND HIGH LATE MARCH SUN ANGLE WILL INHIBIT SOME
ACCUMULATION A BIT...BUT THE GRASSY AREAS WILL SEE SNOW
ACCUMULATE...ESPECIALLY IN ELEVATED AREAS AND LOCATIONS ALONG THE
SLOPES. CURRENT RADAR TRENDS SHOW SNOW SHOWERS ALREADY DEVELOPING
NORTH AND EAST OF BILLINGS. TWEAKED POPS UP IN THESE LOCATIONS.
ACCUMULATIONS TODAY FOR LOWER ELEVATIONS SHOULD BE AROUND AN INCH
WITH POSSIBLY TWO IN PLACES UNDERNEATH HEAVIER SNOW BANDS.
ADJUSTED WINDS A BIT TO BETTER MATCH TRENDS. TWH
&&
.SHORT TERM...VALID FOR TDY AND MON...
CLIPPER SYSTEM DROPPING OUT OF BC WILL MAKE FOR INTERESTING WX
TODAY. INCREASED WESTERLY FLOW AHEAD OF THIS TROF IS INDUCING
PRESSURE FALLS IN CENTRAL MT...BUT SFC EASTERLY WINDS PERSIST ALL
THE WAY TO LIVINGSTON AS OF 08Z DUE TO THE LEE SIDE RIDGING...AND
THE FACT THAT THERE ARE FALLING PRESSURES ACROSS ID TOO. THE
LATTER IS AN INDICATION OF THE STRONG NORTHERLY JET DROPPING
ALONG THE PAC COAST. AS QG FORCING INCREASES WE ARE SEEING CIGS
GRADUALLY LOWER...AND WITH ECHOES ON BLX RADAR BECOMING MORE
WIDESPREAD WE COULD SEE SOME LIGHT PCPN IN OUR NORTH BEFORE TOO
MUCH LONGER...ESPECIALLY WITH THE EAST WINDS IN PLACE. MAIN
FORECAST ISSUES INVOLVE THIS CLIPPER AND ASSOCIATED TRACK OF SFC
LOW...WHICH WILL DICTATE WHERE BEST POTENTIAL FOR PCPN IS LATER
TODAY.
NAM/SREF CONTINUE TO SHOW AN EXTENSIVE PERIOD OF DOWNSLOPING...
WARMER SFC TEMPS AND LESS QPF LATER TODAY...WHEREAS THE GFS/ECMWF
AND UKMET BRING REINFORCING NORTHERLY WINDS INTO OUR CWA SOONER
AND ARE THUS COLDER AND WETTER. THERE ARE SOME SIGNS TO GO WITH
THE GFS HERE...INCLUDING THE PRESSURE FALLS WEST OF THE DIVIDE...
NORTHERLY JET ALONG THE PAC COAST AND DISTINCT SOUTHWARD PUSH OF
COLDER TOPS THRU SOUTHERN BC. ALSO OF NOTE IS THE RAP ANALYZED
EASTERLY 700MB WINDS ALONG THE EAST SLOPES OF THE CANADIAN
ROCKIES WHICH ARE PUSHING SOUTHWARD SLOWLY. ALL OF THIS POINT
TOWARD A STRONGER UPSLOPE EVENT IN OUR WEST LATER TODAY...BUT MUST
STRESS THAT THIS FORECAST IS STILL NOT IN THE HIGHEST CONFIDENCE.
FOLLOWING THE GFS...SNOW WILL DEVELOP AROUND MID TO LATE AFTERNOON
IN OUR WEST...PER DEEPENING LOW TO MID LEVEL FRONTOGENESIS...
FORCING ALOFT AND STRONG INSTABILITY. SECONDARY VORTICITY MAXIMUM
SLIDING DOWN THE PAC COAST SHOULD ALLOW FOR ASCENT TO CONTINUE
THRU MUCH OF THE EVENING...AND THIS IS KEY TO ALLOW FOR THIS
EVENT TO LAST LONGER THAN A COUPLE HOURS. NORTH SLOPES OF THE
BEARTOOTH ABSAROKAS WILL BE FAVORED AS WILL LIVINGSTON AND THE
PARADISE VALLEY PER THE UNSTABLE NW FLOW AND LOCATION OF UPPER
JET. EXPECT THE SNOW SHOWERS TO BE BANDED AND LOCALLY HEAVY...AND
THUS SNOW ACCUMS WILL VARY. HAVE OPTED TO ISSUE A WINTER WX ADVY
FOR 2-5 INCHES OF SNOW IN THESE AREAS. WARM SFC TEMPS WILL BE AN
ISSUE AS IS ALWAYS THE CASE W/ SPRING SNOW EVENTS... BUT THERE
WILL BE IMPACTS TO TRAVEL GIVEN THE POTENTIAL HEAVY SNOWFALL
RATES. IF MORE AMPLIFIED SOLUTION COMES TOGETHER THAN SOME
LOCATIONS COULD SEE MORE THAN 5 INCHES. IF THE NAM VERIFIES THEN
OUR FORECAST SNOW AMOUNTS WILL BE TOO HIGH.
ORIENTATION OF JET FAVORS OUR WEST MORE THAN SHERIDAN AND BIG
HORN COUNTIES...THOUGH STILL LOOKS LIKE 1-2 INCHES NEAR FORT SMITH
AND SHERIDAN AS TROF PASSES THRU LATER TODAY. REMAINDER OF THE
FORECAST AREA SHOULD SEE AMOUNTS ON THE ORDER OF AN INCH...
INCLUDING BILLINGS...AS PCPN WILL BE LARGELY DRIVEN BY INSTABILITY
AND OROGRAPHICS.
SNOW WILL TURN LIGHTER OVERNIGHT BUT SHOULD PERSIST AND PERHAPS
BECOME ENHANCED INTO MONDAY PER NEXT SURGE OF COLDER CANADIAN AIR
AND MODEST FORCING ALOFT...WITH LOW LEVEL TEMPS FAVORABLE FOR
DENDRITIC GROWTH. HAVE RAISED POPS MONDAY IN OUR CENTRAL PARTS
WITH ACCUMS UP TO AN INCH EXPECTED.
TEMPS TODAY WILL BE WARMER THAN YESTERDAY PER AT LEAST A SHORT
COMPONENT OF DOWNSLOPING AND INCREASED MIXING...ESPECIALLY IN OUR
WEST. HIGHS SHOULD CLIMB TO THE UPPER 20S OR 30S. MONDAY WILL SEE
TEMPS FALL BACK TO THE 20S AS STRONG CANADIAN SFC RIDGE BUILDS IN
WITH PRESSURES TO NEAR 1035MB AND AN AIRMASS THAT CAME OUT OF THE
NW CANADIAN ARCTIC.
BILLINGS COULD GET TO ITS SEASONAL SNOWFALL RECORD OF 98.7 INCHES
OVER THE NEXT COUPLE OF DAYS...AND MAY PUSH 100 BY MONDAY OR MAYBE
A LITTLE LATER IN THE WEEK. JKL
.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
TUESDAY SEES WARMER TEMPERATURES AND DRY WEATHER AS AN UPPER LEVEL
RIDGE AXIS MOVES ACROSS THE REGION. MODELS SEEM TO BE TRENDING
COOLER AND NOT BRING AS QUITE A STRONG A WESTERLY WIND PUSH INTO
THE AREA AND ACTUALLY HOLD WINDS IN EASTERN MONTANA TO THE EAST.
LOWERED TEMPERATURES A BIT TO INDICATE A WEAKER WARMUP.
HEIGHTS FALL ON WEDNESDAY AS COLD AIR RETURNS TO THE AREA AND
SUPPORT FOR PRECIPITATION IS GENERATED BY A COMBINATION OF
INSTABILITY AND UPPER LEVEL DYNAMICS AND UPSLOPE. GFS AND ECWMF
DIFFER ON THE FAVORED LOCATION FOR DEVELOPMENT OF A SURFACE LOW
OVER WYOMING SO POSITIONING OF BEST BAROCLINIC BAND IS STILL
UNCERTAIN. THAT WE WILL BE COLDER AND HAVE SOME SNOW IS HIGH
CONFIDENCE...THE AMOUNT OF SNOW IS NOT. PATTERN IS NOT AS DYNAMIC
FOR THURSDAY BUT WILL STILL BE COLD WITH LIGHT PRECIPITATION.
BOTH MODELS BREAK DOWN THE PATTERN FRIDAY AS ANOTHER WEAK UPPER
LEVEL RIDGE NUDGES THE COLD AIR OUT. DOES NOT LOOK LIKE A DRAMATIC
WARMUP SO ONLY 50S EXPECTED. FLOW ALOFT IS NOT ANTICYCLONIC FOR
VERY LONG SO PRECIPITATION INTO THE MOUNTAINS LOOKS GOOD. BORSUM
&&
.AVIATION...
ACROSS THE AREA...PRECIPITATION COVERAGE WILL BEGIN TO INCREASE
OVER THE NEXT SEVERAL HOURS. PERIODS OF MVFR/IFR ARE LIKELY AT
KMLS THROUGH THE DAY...WITH PERIODS OF MVFR/IFR BECOMING MORE
LIKELY AT KLVM...KBIL AND KSHR FROM MID DAY ON. MOUNTAIN
OBSCURATION WILL BECOME MORE WIDESPREAD THROUGH THE DAY.
CONDITIONS WILL IMPROVE OVERNIGHT. STC
&&
.PRELIMINARY POINT TEMP/POPS...
TDY MON TUE WED THU FRI SAT
-------------------------------------------------------
BIL 032 018/027 016/043 030/039 025/041 029/048 035/053
7/J 46/S 41/B 14/J 44/J 22/W 21/B
LVM 037 015/033 014/048 031/046 025/042 027/046 033/051
9/J 83/S 31/B 25/W 55/J 32/W 22/W
HDN 034 016/027 013/045 027/041 025/043 028/049 033/055
7/J 46/S 41/B 13/W 43/W 22/W 11/B
MLS 032 016/026 011/041 026/043 025/040 027/047 033/054
6/J 33/S 11/B 12/W 22/J 22/W 11/B
4BQ 036 016/027 011/042 028/045 026/043 029/048 036/056
6/J 54/S 21/B 12/W 32/W 22/W 11/B
BHK 029 015/025 006/037 022/044 022/039 024/044 031/052
6/J 32/S 01/B 12/W 22/J 22/W 11/B
SHR 038 016/030 013/047 029/049 025/043 025/047 030/053
6/J 65/S 41/B 14/W 55/J 32/W 21/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL MIDNIGHT MDT TONIGHT
FOR ZONES 56-64>66.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
304 AM MDT SUN MAR 23 2014
.SHORT TERM...VALID FOR TDY AND MON...
CLIPPER SYSTEM DROPPING OUT OF BC WILL MAKE FOR INTERESTING WX
TODAY. INCREASED WESTERLY FLOW AHEAD OF THIS TROF IS INDUCING
PRESSURE FALLS IN CENTRAL MT...BUT SFC EASTERLY WINDS PERSIST ALL
THE WAY TO LIVINGSTON AS OF 08Z DUE TO THE LEE SIDE RIDGING...AND
THE FACT THAT THERE ARE FALLING PRESSURES ACROSS ID TOO. THE
LATTER IS AN INDICATION OF THE STRONG NORTHERLY JET DROPPING
ALONG THE PAC COAST. AS QG FORCING INCREASES WE ARE SEEING CIGS
GRADUALLY LOWER...AND WITH ECHOES ON BLX RADAR BECOMING MORE
WIDESPREAD WE COULD SEE SOME LIGHT PCPN IN OUR NORTH BEFORE TOO
MUCH LONGER...ESPECIALLY WITH THE EAST WINDS IN PLACE. MAIN
FORECAST ISSUES INVOLVE THIS CLIPPER AND ASSOCIATED TRACK OF SFC
LOW...WHICH WILL DICTATE WHERE BEST POTENTIAL FOR PCPN IS LATER
TODAY.
NAM/SREF CONTINUE TO SHOW AN EXTENSIVE PERIOD OF DOWNSLOPING...
WARMER SFC TEMPS AND LESS QPF LATER TODAY...WHEREAS THE GFS/ECMWF
AND UKMET BRING REINFORCING NORTHERLY WINDS INTO OUR CWA SOONER
AND ARE THUS COLDER AND WETTER. THERE ARE SOME SIGNS TO GO WITH
THE GFS HERE...INCLUDING THE PRESSURE FALLS WEST OF THE DIVIDE...
NORTHERLY JET ALONG THE PAC COAST AND DISTINCT SOUTHWARD PUSH OF
COLDER TOPS THRU SOUTHERN BC. ALSO OF NOTE IS THE RAP ANALYZED
EASTERLY 700MB WINDS ALONG THE EAST SLOPES OF THE CANADIAN
ROCKIES WHICH ARE PUSHING SOUTHWARD SLOWLY. ALL OF THIS POINT
TOWARD A STRONGER UPSLOPE EVENT IN OUR WEST LATER TODAY...BUT MUST
STRESS THAT THIS FORECAST IS STILL NOT IN THE HIGHEST CONFIDENCE.
FOLLOWING THE GFS...SNOW WILL DEVELOP AROUND MID TO LATE AFTERNOON
IN OUR WEST...PER DEEPENING LOW TO MID LEVEL FRONTOGENESIS...
FORCING ALOFT AND STRONG INSTABILITY. SECONDARY VORTICITY MAXIMUM
SLIDING DOWN THE PAC COAST SHOULD ALLOW FOR ASCENT TO CONTINUE
THRU MUCH OF THE EVENING...AND THIS IS KEY TO ALLOW FOR THIS
EVENT TO LAST LONGER THAN A COUPLE HOURS. NORTH SLOPES OF THE
BEARTOOTH ABSAROKAS WILL BE FAVORED AS WILL LIVINGSTON AND THE
PARADISE VALLEY PER THE UNSTABLE NW FLOW AND LOCATION OF UPPER
JET. EXPECT THE SNOW SHOWERS TO BE BANDED AND LOCALLY HEAVY...AND
THUS SNOW ACCUMS WILL VARY. HAVE OPTED TO ISSUE A WINTER WX ADVY
FOR 2-5 INCHES OF SNOW IN THESE AREAS. WARM SFC TEMPS WILL BE AN
ISSUE AS IS ALWAYS THE CASE W/ SPRING SNOW EVENTS... BUT THERE
WILL BE IMPACTS TO TRAVEL GIVEN THE POTENTIAL HEAVY SNOWFALL
RATES. IF MORE AMPLIFIED SOLUTION COMES TOGETHER THAN SOME
LOCATIONS COULD SEE MORE THAN 5 INCHES. IF THE NAM VERIFIES THEN
OUR FORECAST SNOW AMOUNTS WILL BE TOO HIGH.
ORIENTATION OF JET FAVORS OUR WEST MORE THAN SHERIDAN AND BIG
HORN COUNTIES...THOUGH STILL LOOKS LIKE 1-2 INCHES NEAR FORT SMITH
AND SHERIDAN AS TROF PASSES THRU LATER TODAY. REMAINDER OF THE
FORECAST AREA SHOULD SEE AMOUNTS ON THE ORDER OF AN INCH...
INCLUDING BILLINGS...AS PCPN WILL BE LARGELY DRIVEN BY INSTABILITY
AND OROGRAPHICS.
SNOW WILL TURN LIGHTER OVERNIGHT BUT SHOULD PERSIST AND PERHAPS
BECOME ENHANCED INTO MONDAY PER NEXT SURGE OF COLDER CANADIAN AIR
AND MODEST FORCING ALOFT...WITH LOW LEVEL TEMPS FAVORABLE FOR
DENDRITIC GROWTH. HAVE RAISED POPS MONDAY IN OUR CENTRAL PARTS
WITH ACCUMS UP TO AN INCH EXPECTED.
TEMPS TODAY WILL BE WARMER THAN YESTERDAY PER AT LEAST A SHORT
COMPONENT OF DOWNSLOPING AND INCREASED MIXING...ESPECIALLY IN OUR
WEST. HIGHS SHOULD CLIMB TO THE UPPER 20S OR 30S. MONDAY WILL SEE
TEMPS FALL BACK TO THE 20S AS STRONG CANADIAN SFC RIDGE BUILDS IN
WITH PRESSURES TO NEAR 1035MB AND AN AIRMASS THAT CAME OUT OF THE
NW CANADIAN ARCTIC.
BILLINGS COULD GET TO ITS SEASONAL SNOWFALL RECORD OF 98.7 INCHES
OVER THE NEXT COUPLE OF DAYS...AND MAY PUSH 100 BY MONDAY OR MAYBE
A LITTLE LATER IN THE WEEK.
JKL
.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
TUESDAY SEES WARMER TEMPERATURES AND DRY WEATHER AS AN UPPER LEVEL
RIDGE AXIS MOVES ACROSS THE REGION. MODELS SEEM TO BE TRENDING
COOLER AND NOT BRING AS QUITE A STRONG A WESTERLY WIND PUSH INTO
THE AREA AND ACTUALLY HOLD WINDS IN EASTERN MONTANA TO THE EAST.
LOWERED TEMPERATURES A BIT TO INDICATE A WEAKER WARMUP.
HEIGHTS FALL ON WEDNESDAY AS COLD AIR RETURNS TO THE AREA AND
SUPPORT FOR PRECIPITATION IS GENERATED BY A COMBINATION OF
INSTABILITY AND UPPER LEVEL DYNAMICS AND UPSLOPE. GFS AND ECWMF
DIFFER ON THE FAVORED LOCATION FOR DEVELOPMENT OF A SURFACE LOW
OVER WYOMING SO POSITIONING OF BEST BAROCLINIC BAND IS STILL
UNCERTAIN. THAT WE WILL BE COLDER AND HAVE SOME SNOW IS HIGH
CONFIDENCE...THE AMOUNT OF SNOW IS NOT. PATTERN IS NOT AS DYNAMIC
FOR THURSDAY BUT WILL STILL BE COLD WITH LIGHT PRECIPITATION.
BOTH MODELS BREAK DOWN THE PATTERN FRIDAY AS ANOTHER WEAK UPPER
LEVEL RIDGE NUDGES THE COLD AIR OUT. DOES NOT LOOK LIKE A DRAMATIC
WARMUP SO ONLY 50S EXPECTED. FLOW ALOFT IS NOT ANTICYCLONIC FOR
VERY LONG SO PRECIPITATION INTO THE MOUNTAINS LOOKS GOOD. BORSUM
&&
.AVIATION...
EXPECT INCREASING CLOUDS THROUGH THE MORNING HOURS WITH
PRECIPITATION DEVELOPING ALONG THE FOOTHILLS AND KLVM BY 1600UTC
INCLUDING MOUNTAIN OBSCURATION. PRECIPITATION WILL SPREAD INTO
CENTRAL AREAS LIKE KBIL AND KSHR AFTER 1800UTC. MVFR CONDITIONS
POSSIBLE BY MID AFTERNOON FOR KBIL...KSHR AND KLVM WITH BRIEF
PERIODS OF IFR AFTER 2200UTC. CONDITIONS WILL IMPROVE LATE
TONIGHT. EXPECT LESS PRECIPITATION FOR KMLS BUT PERIODS OF MVFR
CEILINGS ARE POSSIBLE. BORSUM
&&
.PRELIMINARY POINT TEMP/POPS...
TDY MON TUE WED THU FRI SAT
-------------------------------------------------------
BIL 032 018/027 016/043 030/039 025/041 029/048 035/053
7/S 46/S 41/B 14/J 44/J 22/W 21/B
LVM 037 015/033 014/048 031/046 025/042 027/046 033/051
9/S 83/S 31/B 25/W 55/J 32/W 22/W
HDN 034 016/027 013/045 027/041 025/043 028/049 033/055
7/S 46/S 41/B 13/W 43/W 22/W 11/B
MLS 032 016/026 011/041 026/043 025/040 027/047 033/054
7/S 33/S 11/B 12/W 22/J 22/W 11/B
4BQ 036 016/027 011/042 028/045 026/043 029/048 036/056
6/S 54/S 21/B 12/W 32/W 22/W 11/B
BHK 029 015/025 006/037 022/044 022/039 024/044 031/052
6/S 32/S 01/B 12/W 22/J 22/W 11/B
SHR 038 016/030 013/047 029/049 025/043 025/047 030/053
6/W 65/S 41/B 14/W 55/J 32/W 21/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT FROM NOON TODAY TO MIDNIGHT
MDT TONIGHT FOR ZONES 56-64>66.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
319 PM CDT SUN MAR 23 2014
.SYNOPSIS...
ISSUED AT 318 PM CDT SUN MAR 23 2014
A HIGH LATITUDE BLOCK CENTERED OVER ALASKA IS EXPECTED TO PERSIST
THROUGH THE NEXT 7 DAYS. THE BLOCK AND ASSOCIATED HIGH AMPLITUDE
FLOW OFF THE ARCTIC SHOULD SEND TWO STRONG ARCTIC HIGH PRESSURE
SYSTEMS THROUGH THE FCST AREA. A STORM COULD DEVELOP THURSDAY AHEAD
OF THE SECOND ARCTIC HIGH. A BRIEF WARM UP IS EXPECTED WEDNESDAY
AHEAD OF THIS POSSIBLE STORM.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 318 PM CDT SUN MAR 23 2014
SFC LOW PRESSURE FORMING ALONG AN ARCTIC FRONT STRETCHING FROM
BRITISH COLUMBIA TO DEEP SOUTH TEXAS TRACKS SOUTH TONIGHT AND DROPS
A WEAK REINFORCING COLD FRONT THROUGH THE FCST AREA OVERNIGHT. THE
MODELS INCLUDING THE HRRR AND RAP ARE SPLITTING THE UPPER LEVEL
ENERGY THROUGH THE MISSOURI BASIN AND THE CNTL ROCKIES PRODUCING
JUST SCATTERED SNOW SHOWERS AHEAD AND BEHIND THE FRONT. THE RESULT
IS A WELL MIXED ATMOSPHERE TONIGHT AND MONDAY KEEPING LOWS ON THE
WARM SIDE TONIGHT AND HIGHS COOL MONDAY.
THE BEST GUESS ON LOWS TONIGHT IS 20S AND HIGHS MONDAY IN THE 30S TO
LOWER 40S. THE RAP WHICH HAS BEEN SHOWING GOOD SKILL WITH THE
TRAPPED MOISTURE AND STRATUS TODAY LIFTS THESE CLOUDS NORTH INTO THE
ARCTIC FRONT TONIGHT FOR MOSTLY CLOUDY CONDITIONS. THE NAM THEN
MIXES THESE LOW CLOUDS OUT MONDAY AFTN WHILE REDEVELOPING SNOW
SHOWERS MONDAY AFTN ACROSS NRN NEB AS A SECOND STRONGER SURGE OF
ARCTIC AIR DESCENDS THROUGH THE NRN HIGH PLAINS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 318 PM CDT SUN MAR 23 2014
AN ACTIVE PATTERN WILL PERSIST MONDAY NIGHT THROUGH THURSDAY AS
NORTHWEST FLOW THROUGH TUESDAY TRANSITIONS INTO ZONAL TO SOUTHWEST
FLOW WEDNESDAY INTO THURSDAY. A STORM SYSTEM WILL AFFECT THE
REGION WEDNESDAY NIGHT AND THURSDAY. IN ADDITION...BELOW TO MUCH
BELOW AVERAGE TEMPERATURES WILL PERSIST TUESDAY AS MODIFIED
ARCTIC HIGH PRESSURE BUILDS INTO THE MIDWEST.
MONDAY NIGHT...A REINFORCING COLD FRONT WILL BRING MODIFIED
ARCTIC AIR IN. A STALLED FRONT NEAR THE FRONT RANGE WILL BRING
WIDESPREAD STRATUS ALONG THE ADJACENT HIGH PLAINS. A WEAK
DISTURBANCE LOOKS SUFFICIENT FOR FLURRIES POSSIBLE ACROSS THE
PANHANDLE INTO SWRN NEBR OVERNIGHT. ON TUESDAY...A RETURN SOUTHERLY
FLOW WILL DEVELOP. HOWEVER WITH H85 TEMPS ONLY RISING TO NEAR -7C
IN THE NORTHEAST...HIGHS ONLY IN THE MID 30S EXPECTED...WHILE THE
WEST AND SOUTHWEST SHOULD SEE HIGHS IN THE LOWER TO MID 40S.
MUCH...MUCH WARMER ON WEDNESDAY FROM THE MID 60S TO LOWER 70S AHEAD
OF ANOTHER COLD FRONT. MEDIUM RANGE MODELS CONTINUE TO SHOW
DIFFERENCES WITH STORM SYSTEM WEDNESDAY NIGHT AND THURSDAY. THE
GFS CONTINUES TO FORECAST A FAST MOVING OPEN WAVE...WHILE THE
ECMWF AND GEM INDICATE A CLOSED LOW AND TROWEL DEVELOPING. THE
ECMWF HAS REMAINED VERY CONSISTENT THE PAST 3 RUNS AND PREFER ITS
SOLUTION BEST. THEREFORE POPS RAISED SLIGHTLY TO 40-50 PERCENT
WITH SNOW SUPPORTED IN THE NCTRL AND RAIN IN THE SOUTH. FALLING
TEMPS AND WET BULB TEMPS THROUGH THE DAY SUPPORT SNOW CHANCES.
NORTH WINDS OF 20 TO 30 MPH ARE ALSO FORECAST. DESPITE MODEL
DIFFERENCES...WILL NEED TO CLOSELY MONITOR THIS SYSTEM...SINCE IT
HAS THE POTENTIAL TO BECOME A SPRING SNOW STORM IN THE REGION.
DRY FRIDAY THROUGH SUNDAY AS A BROAD RIDGE WILL BECOME ESTABLISHED
ACROSS THE REGION. TEMPERATURES WILL WARM TO THE 60S TO LOW 70S BY
THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1221 PM CDT SUN MAR 23 2014
THE SWATH OF MVFR/IFR CIGS ALONG AND WEST OF HIGHWAY 83 IS
EXPECTED TO CONTINUE LIFTING NORTH AND THEN INTERACT WITH A
SOUTHWARD MOVING ARCTIC FRONT TONIGHT. THE FRONT IS ASSOCIATED
WITH AN ONGOING DISTURBANCE ACROSS SERN MT AND THE MODELS SUGGEST
SCATTERED SNOW SHOWERS TONIGHT AS THE FRONT APPROACHES. THIS
ACTIVITY IS EXPECTED TO BECOME ISOLATED MONDAY MORNING AFTER THE
FRONT MOVES THROUGH. OVERALL THE CONSENSUS SUGGESTS MVFR/IFR CIGS WILL
CONTINUE TO BE FAIRLY WIDESPREAD THIS AFTN THROUGH TONIGHT AND
PERHAPS IMPROVE TO SCATTERED MVFR/VFR MONDAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CDC
SHORT TERM...CDC
LONG TERM...ROBERG
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1146 AM CDT SUN MAR 23 2014
.UPDATE...
ISSUED AT 1145 AM CDT SUN MAR 23 2014
MAIN ADJUSTMENT TO THE GOING FORECAST WAS TO SLOW DOWN THE ONSET
OF SNOW...AND REDUCE THE PROBABILITIES SLIGHTLY. THIS WILL
EFFECTIVELY REDUCE THE FORECAST AMOUNTS SLIGHTLY. THE MAIN ISSUE
IS THE DRY AIR IN THE LOWER AND MID LEVELS THAT WILL NEED TO BE
SATURATED...AND THAT SHOULD TAKE A FEW MORE HOURS. WE DONT
ANTICIPATE ANYTHING FALLING PRIOR TO ABOUT 09Z...AND THERE SHOULD
JUST BE A BRIEF WINDOW OF A FEW HOURS OF LIGHT SNOW.
THE 12Z NAM AND 15Z RAP WERE QUITE DRY...HOWEVER THE 12Z GFS AND
GEM CONTINUED TO SUPPORT THE SATURATION AND EVENTUAL LIGHT SNOW.
WILL TAKE A CLOSER LOOK AND ADJUST AS NECESSARY THIS AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 323 AM CDT SUN MAR 23 2014
SNOW CHANCES TONIGHT AND MONDAY ARE THE MAIN FORECAST CONCERNS.
UPPER LEVEL SHORTWAVE THAT BROUGHT SNOW TO WESTERN NEBRASKA AND
NORTHERN KANSAS SATURDAY AND SATURDAY NIGHT WAS SHEARING OUT AS IT
MOVED OFF TO OUR EAST THIS MORNING. SUBSIDENCE BEHIND IT WAS ERODING
CLOUDS ACROSS EASTERN NEBRASKA AND WESTERN IOWA. MEANWHILE COLD AND
DRY SURFACE HIGH PRESSURE WAS SETTLING OVER THE REGION...WITH
TEMPERATURES IN THE TEENS AND DEW POINTS IN THE SINGLE DIGITS IN OUR
AREA. OUR NEXT WEATHER-MAKER WAS NOTED IN WATER VAPOR SATELLITE
LOOPS MOVING FROM BRITISH COLUMBIA INTO SOUTHERN ALBERTA. THIS
SHORTWAVE IS SCHEDULED TO DIVE SOUTHEAST TODAY AND REACH OUR AREA
LATE TONIGHT BEFORE EXITING TO THE EAST MONDAY AFTERNOON. BECAUSE
THIS WAVE HAD MOVED ONSHORE FROM THE GULF OF ALASKA EARLIER
TODAY...THERE HAS BEEN SOMEWHAT BETTER SAMPLING FROM UPPER AIR
STATIONS. SO WOULD EXPECT MODELS TO HAVE A LITTLE BETTER HANDLE ON
EXPECTED OUTCOME.
TO THAT END...THERE HAS BEEN A SHIFT IN MODEL OUTPUT OF POTENTIAL
SNOW AMOUNTS AND LOCATION. THERE IS DECENT CONSENSUS IN VORTICITY
TRACK ACROSS SOUTH DAKOTA...AND ASSOCIATED BAND OF LIGHT SNOW THERE
TONIGHT. AND THERE IS CONSISTENCY IN DEVELOPING SNOW NEAR A WEAK
SURFACE LOW ALONG COLD FRONT IN EASTERN NEBRASKA OVERNIGHT...WITH
THE AXIS OF HIGHEST AMOUNTS FARTHER SOUTH THAN PREVIOUS RUNS.
HOWEVER NAM IS SLOWER TO DEVELOP PRECIPITATION...WAITING UNTIL
CLOSER TO 12Z MONDAY BEFORE DEVELOPMENT...WHILE GFS/ECMWF DEVELOP
SNOW CLOSER TO 06Z.
DRY AIR CURRENTLY IN PLACE LENDS SOME CREDENCE TO NAM SOLUTION AS
DEEP LAYER OF DRYING WILL HAVE TO BE OVERCOME BEFORE SIGNIFICANT
SNOWS CAN OCCUR. AND CROSS- AND TIME-SECTIONS OF MOISTURE PROFILES
FROM GFS SHOW THIS AS WELL...WHICH RUN COUNTER TO ITS QPF PROGS.
WILL FOLLOW THIS TREND FOR THIS FORECAST...HOLDING OFF ON MOST OF
THE ACCUMULATING SNOW UNTIL AFTER 06Z.
EXPECT LIGHT SNOW TO BREAK OUT ACROSS OUR WEST NEAR 06Z AS AREA OF
700-600MB FRONTOGENESIS INVADES THERE...THEN SPREAD SNOW FROM WEST-
NORTHWEST TO EAST-SOUTHEAST OVERNIGHT. FRONTOGENESIS INTENSIFIES AS
SYSTEM MOVES EAST...AND CROSS-SECTIONS INDICATE BETTER SATURATION
UNDER BEST AGEOSTROPHIC FORCING NEAR AND EAST OF THE MISSOURI RIVER.
WILL LIKELY SEE A BROAD AREA OF LIGHT SNOW ACROSS MOST OF THE CWA
WITH A HALF OF AN INCH OF SNOW COMMON. THEN A MORE NARROW BAND OF 1
TO 2 INCHES IS EXPECTED UNDER BEST FRONTOGENETICAL FORCING ALONG A
LINE FROM COLUMBUS TO THE LINCOLN AND OMAHA METRO AREAS...INTO
SOUTHWEST IOWA NEAR SHENANDOAH AND CLARINDA. GARCIA CALCULATIONS
USING 290K SURFACE AND A 4 TO 6 HOUR POTENTIAL SNOW EVENT CONCUR
WITH THE ABOVE AMOUNTS.
SNOW WILL BE EXITING WESTERN IOWA MONDAY AFTERNOON AS SHORTWAVE
RACES EAST. GUSTY NORTHWEST WINDS AND CLEARING SKIES WILL
FOLLOW...HELPING TO NUDGE TEMPERATURES BACK INTO THE 30S. COLD
ADVECTION MONDAY NIGHT UNDER CLEAR SKIES AND DIMINISHING WINDS
SHOULD COOL TEMPERATURES BACK INTO THE TEENS. AND EXPECTED SNOW
COVER MEANS EVEN COLDER LOWS ARE CERTAINLY POSSIBLE. COOL HIGH
PRESSURE WILL REMAIN OVERHEAD TUESDAY...SO TEMPERATURES THEN WILL
STILL BE RATHER CHILLY.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 323 AM CDT SUN MAR 23 2014
WARMER TEMPERATURES ARE EXPECTED IN THE LONGER TERM PERIOD...WITH A
CHANCE FOR PRECIPITATION COMING WEDNESDAY NIGHT THROUGH THURSDAY
NIGHT.
MID LEVEL TROUGH WILL APPROACH THE PLAINS WEDNESDAY...LOWERING
SURFACE PRESSURES IN THE HIGH PLAINS AND BRINGING GUSTY SOUTH WINDS
TO THE REGION. HAVE HIGHS WEDNESDAY BACK INTO THE 50S. LOW LEVEL JET
STRENGTHENS MARKEDLY WEDNESDAY NIGHT...DRAWING HIGHER THETA-E AIR
INTO EASTERN NEBRASKA AND SOUTHWEST IOWA. WEAK ELEVATED INSTABILITY
IS NOTED ON FORECAST SOUNDINGS THEN...SO SCATTERED SHOWERS ARE
CERTAINLY POSSIBLE. HOWEVER BULK OF PRECIPITATION CHANCES WILL COME
THURSDAY AS UPPER TROUGH AND SURFACE FRONT MOVE THROUGH. SHOWERS
AND MAYBE THUNDER ARE POSSIBLE AHEAD OF THE FRONT DURING THE DAY.
THEN COOLING BEHIND THESE FEATURES WILL BE ENOUGH TO CHANGE
LINGERING RAIN TO SNOW. WILL HAVE TO WATCH THIS SYSTEM AS ECMWF IS
SUGGESTING A SLOWER SYSTEM WHICH WOULD ALLOW MORE POTENTIAL
SNOWFALL BEFORE PRECIPITATION ENDS BY FRIDAY MORNING. A GENERAL
WESTERLY PACIFIC MID LEVEL FLOW WILL PREVAIL TO END THE
FORECAST...SO A BRIEF COOLDOWN BEHIND FRONT FRIDAY WILL BE
REPLACED BY MILDER TEMPERATURES SATURDAY.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1145 AM CDT SUN MAR 23 2014
CLEAR SKIES AND LIGHT WINDS WILL BE FOUND OVER THE TAF SITES THIS
AFTERNOON...WITH WINDS BECOMING SOUTH AND INCREASING THROUGHOUT
THE DAY. A COLD FRONT AND WEAK SHORTWAVE WILL MOVE THROUGH EARLY
MONDAY MORNING WHICH WILL BRING THE WINDS AROUND TO THE NORTH.
THIS MINOR SYSTEM WILL RESULT IN OVERCAST SKIES WITH CIGS AROUND
050 LATE TONIGHT...THEN LOWERING INTO THE 010-020 RANGE AROUND
SUNRISE...THEN LIFTING TO VFR AGAIN MONDAY MORNING. LIGHT SNOW IS
EXPECTED FOR A FEW HOURS BEFORE AND AFTER SUNRISE...BUT VSBYS
SHOULD REMAIN VFR FOR MOST OF THAT TIME. SNOW ACCUMULATIONS OF AN
INCH OR LESS ARE PREDICTED. ANY LINGERING LIGHT SNOW MONDAY
MORNING SHOULD END BY MID MORNING AT KOFK AND KLNK AND BY NOON AT
KOMA.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...NIETFELD
SHORT TERM...DERGAN
LONG TERM...DERGAN
AVIATION...NIETFELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1010 PM EDT MON MAR 24 2014
.SYNOPSIS... MODIFIED ARCTIC HIGH PRESSURE WILL EXTEND ACROSS
CENTRAL NC THIS AFTERNOON THEN DRIFT OFFSHORE THIS EVENING. A
COMPLEX LOW PRESSURE SYSTEM WILL DEVELOP FROM THE NORTHEASTERN
GULF OF MEXICO TO OFFSHORE THE SOUTHEAST U.S. COAST LATE
TONIGHT...THEN RAPIDLY INTENSIFY AS IT TRACKS UP THE CAROLINA
AND MIDDLE ATLANTIC COASTS TUESDAY AND TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH TUESDAY NIGHT/...
AS OF 1010 PM MONDAY...
THROUGH MID-MORNING TUESDAY... REGIONAL SURFACE ANALYSIS THIS
EVENING SHOWS WEAK HIGH PRESSURE JUST EAST OF THE DELMARVA... AN
INVERTED TROUGH EXTENDING UP THE APPALACHIANS...AND A WEAK LOW
FORMING EAST OF DAYTONA. ALOFT... RAOBS SHOW WESTERLY FLOW OVER THE
SOUTHEAST US AND A SHORTWAVE TROUGH MOVING INTO THE MID MS RIVER
VALLEY REGION. THIS LEAD SHORTWAVE WILL HELP DRIVE THE DEVELOPING
SURFACE LOW NORTHEAST INTO THE ATLANTIC TONIGHT AND EARLY TUESDAY.
MEANWHILE...A 125KT UPPER JET DIVING THROUGH THE CENTRAL PLAINS WILL
BEGIN TO AMPLIFY THE UPPER LEVEL FLOW LATE TONIGHT...LEADING TO A
SECONDARY SURFACE LOW EAST OF CAPE HATTERAS BY TUESDAY EVENING.
UPSTREAM THIS EVENING...PRECIP ASSOCIATED WITH THE LEAD SHORTWAVE IS
DRYING UP...BY EXPECT PRECIP TO REDEVELOP FROM THE SOUTHERN
APPALACHIANS TO THE BLUE RIDGE BY AROUND 08Z AS THE UPPER TROUGH
AMPLIFIES AND DCVA/HEIGHT FALLS BEGIN TO INCREASE. TO THE
SOUTHEAST... PRECIP WILL ALSO BREAK OUT WITH SLOWLY STRENGTHENING
LOW LEVEL WARM ADVECTION AND CYCLOGENESIS OVER THE SOUTH CAROLINA
COASTAL AREA...THOUGH MOST OF THE CONVECTION ALLOWING MODELS NOW
KEEP PRECIP SOUTHEAST OF SAMPSON AND WAYNE COUNTIES THROUGH 12Z.
WITH THE AFOREMENTIONED AREAS OF FORCING NOT LINKING UP UNTIL
TUESDAY AFTERNOON AS THE SYSTEM BEGINS TO LIFT AWAY FROM THE AREA
AND DEEPEN...MODELS CONTINUE SHOW SHOW RELATIVELY LIGHT QPF AMOUNTS
AROUND ONE TENTH OF AN INCH IN THE NORTHWEST AND SOUTHEAST PORTIONS
OF THE CWA PRIOR TO 15Z.
REGARDING THE CHANCE OF SNOW IN THE NORTHWEST PIEDMONT...THE NAM AND
GFS FORECAST SOUNDINGS STILL SHOW SIGNIFICANTLY DIFFERENT BOUNDARY
LAYER MOISTURE...WITH THE NAM SATURATING MUCH MORE RAPIDLY THAN THE
GFS. THE LATEST RAP APPEARS TO BE SOMEWHERE IN BETWEEN. IN ANY
CASE...WETBULB PROFILES CONTINUE TO SUPPORT THE POTENTIAL FOR BURSTS
OF SNOW WITH HEAVIER PRECIP RATES...WITH THE BEST CHANCE BETWEEN 10Z
AND 14Z.. WITH NEAR SURFACE TEMPERATURES AT OR A LITTLE ABOVE
FREEZING...AND TOP SOIL TEMPS IN THE LOW-MID 40S...ANY SNOW THAT
OCCURS WILL LIKELY MELT ON IMPACT. THE EXCEPTION TO THIS WILL BE
"IF" A BURST OF MODERATE TO HEAVY SNOW WERE TO OCCUR...QUICKLY
COATING GRASSY AREAS AND THE TOPS OF CARS.
AS THE BULK OF THE PRECIP TRANSITIONS TOWARD EASTERN NC AND TEMPS
WARM A FEW DEGREES...ANY LINGERING PRECIP OVER THE NORTHWEST AND
NORTHERN PIEDMONT WILL BECOME ALL RAIN BY MIDDAY. -SMITH
TUESDAY AFTERNOON...THE NORTHERN STREAM S/W WILL TAKE ON A NEGATIVE
TILT AS IT CROSSES THE MID ATLANTIC STATES. THIS WILL LEAD TO SFC
CYCLOGENESIS OFF OF HATTERAS BY LATE TUESDAY WITH RAPID DEEPENING
TUESDAY NIGHT AS IT LIFTS TO THE N-NE. THIS MOVEMENT WILL TAKE THE
BULK OF THE PRECIP AWAY FROM CENTRAL NC BY EARLY TUESDAY
EVENING..WITH CLEARING SKIES DURING THE EVENING HOURS.
THE DEEPENING LOW COUPLED WITH ANOTHER CANADIAN HIGH OVER THE MID MS
VALLEY WILL CREATE BLUSTERY NW WINDS ACROSS CENTRAL NC LATE TUESDAY
THROUGH TUESDAY NIGHT. EXPECT WIND GUSTS 20-25 MPH WELL INTO THE
NIGHT. THIS WIND WILL ALSO USHER ANOTHER BATCH OF COOL DRIER AIR
INTO CENTRAL NC. THE WIND COUPLED WITH COLD AIR WILL RESULT IN WIND
CHILL VALUES IN THE UPPER TEENS TO AROUND 20 DEGREES LATE TUESDAY
NIGHT. MIN TEMPS MID 20S NW TO NEAR 30 SE. -WSS
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 230 PM MONDAY...
UPPER TROF SHIFTS EAST AND THE COASTAL STORM LIFTS NORTHEAST QUICKLY
ON WEDNESDAY...WITH CLEAR SKIES AND THE PRESSURE GRADIENT RELAXING
AS THE MORNING PROGRESSES. COLD AIR ADVECTION WILL BE WELL
UNDERWAY...COMPLIMENTS OF SURFACE HIGH PRESSURE BUILDING IN FROM THE
WEST...WITH NORTHWEST WINDS 10 TO 15 MPH WITH GUSTS TO 25 MPH AROUND
DAYBREAK...WITH GUSTS DIMINISHING TO 15 MPH IN THE AFTERNOON. HIGHS
WILL BE IN THE MID 40S.
THE SURFACE HIGH WILL MOVE OVERHEAD WEDNESDAY NIGHT...PRODUCING
IDEAL RADIATIONAL CONDITIONS AND A COLDER OVERNIGHT PERIOD...
TEMPERATURE-WISE...WITH LOWS SOLIDLY IN THE MID 20S. OUTLYING AREAS
ARE APT TO SEE SOME LOW 20S READINGS AROUND SUNRISE. THESE LOW
TEMPERATURES WILL THREATEN CROPS THAT WERE PLANTED EARLY AS WELL AS
FRUIT TREES AND STRAWBERRIES THAT ARE IN BLOOM. ON THE POSITIVE
SIDE...THERE WILL BE NO APPRECIABLE WIND CHILL DUE TO THE CALM WINDS.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 230 PM MONDAY...
SOME WELCOME MODERATION IN TEMPERATURES IS ON TAP AS WE HEAD INTO
LATE WEEK AS THE SURFACE HIGH PRESSURE EDGES OFFSHORE AND A LOW
AMPLITUDE SHORT WAVE RIDGE TRANSLATES ACROSS THE AREA THURSDAY. THE
RESULTING SOUTHERLY RETURN FLOW AND SUNSHINE WILL ALLOW HIGHS TO
REACH THE MID TO UPPER 50S.
LOW LEVEL MOISTURE WILL BE RISING QUICKLY THURSDAY NIGHT AS DEW
POINTS CLIMB THROUGH THE 30S OVERNIGHT. THIS WILL RESULT IN
ISENTROPIC LIFT...WITH OVERCAST SKIES AND POSSIBLY SOME LIGHT RAIN
IN THE WEST BY FRIDAY MORNING. MINS WILL BE CORRESPONDINGLY MILDER
DUE TO THE SOUTHERLY FLOW AND DEVELOPING LOW CLOUDINESS...WITH MINS
FROM 40 TO 45.
UP TO THIS POINT THE MODELS HAVE BEEN IN RELATIVE AGREEMENT...
ESPECIALLY IN THE SENSIBLE WEATHER IMPACTS OVER CENTRAL NC THROUGH
FRIDAY...WITH BOTH ECM AND GFS DEPICTING A SURFACE LOW PRESSURE AREA
LIFTING INTO THE GREAT LAKES THURSDAY NIGHT WITH THE TRAILING COLD
FRONT EDGING EAST TOWARDS THE AREA FRIDAY. GFS IS HOLDING ONTO THE
IDEA OF DEVELOPING A TRAILING SOUTHERN STREAM SHORT WAVE INTO A
SECOND LOW PRESSURE AREA WHICH TRAILS THE INITIAL LOW
NORTHEAST...AND DELAYING THE FRONTAL PASSAGE UNTIL SATURDAY NIGHT.
MEANWHILE...THE ECM MAINTAINS A PROGRESSIVE SYSTEM WITH A CLEANER
SURFACE COLD FRONTAL PASSAGE FRIDAY NIGHT OR EARLY SATURDAY.
ONGOING FORECAST TRENDS ARE BASED ON THE FASTER ECM SOLUTION AND
WILL MAINTAIN THIS TREND PENDING A CLEARER SOLUTION HOPEFULLY TO
BECOME EVIDENT IN SUBSEQUENT RUNS. THUS WILL HAVE HIGH CHANCE POPS
FRIDAY NIGHT AND SATURDAY...WITH DRYING SATURDAY NIGHT. HIGHS FRIDAY
SHOULD BE AFFECTED BY THE IN-SITU EFFECTS OF THE ISENTROPICALLY
INDUCED LIGHT RAIN THURSDAY NIGHT...AND WILL UNDERCUT GUIDANCE BY
ABOUT 5 DEGREES IN THE CLIMATOLOGICALLY FAVORED AREA...GIVING US
NEAR 60 NORTHWEST TO 70 SOUTHEAST. MILD TEMPS IN THE WARM SECTOR
FRIDAY NIGHT...50 TO 55...AND SATURDAY SHOULD BE MILD AS WELL...MID
TO UPPER 60S...WITH POST FRONTAL COLD AIR ADVECTION DELAYED UNTIL
SATURDAY NIGHT...EVEN ON THE FASTER ECM...WITH MINS SUNDAY MORNING
WITHIN A COUPLE OF DEGREES EITHER SIDE OF 40. ZONAL FLOW = HIGH AND
DRY FOR DAYS 6 AND 7...WITH SUNDAYS HIGHS A BIT BELOW NORMAL...LOW
TO MID 60S...WARMING TO THE UPPER 60S MONDAY.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 800 PM MONDAY...
VERY DRY AIR IN THE LOW-LEVELS WILL RESULT IN A CONTINUATION OF VFR
CONDITIONS WELL INTO THE OVERNIGHT HOURS. A VIGOROUS UPPER LEVEL
DISTURBANCE APPROACHING FROM THE WEST COUPLED WITH A DEVELOPING LOW
OFF THE SE COAST WILL RESULT IN ADVERSE AVIATION CONDITIONS FOR
TUESDAY.
PRECIPITATION IS EXPECTED TO BREAK OUT ACROSS THE NW
PIEDMONT(KINT AND KGSO)AROUND DAYBREAK AS WITH CEILINGS LOWERING TO
MVFR AND QUITE POSSIBLY IFR. PRECIPITATION COULD FALL AS SNOW OR A
RAIN/SNOW MIX AT THE START AT KINT TO KGSO...BEFORE CHANGING OVER TO
ALL RAIN BY 15Z.
EAST OF THE TRIAD...LIGHT PRECIPITATION WILL SPREAD WEST TO EAST
ACROSS THE AREA BETWEEN 14 TO 18Z...FALLING AS ALL RAIN...WITH
PREDOMINATELY MVFR CONDITIONS.
THE LOW PRESSURE SYSTEM WILL LIFT NORTH-NORTHEAST OFF THE NC COAST
LATE TUESDAY INTO TUESDAY NIGHT WITH DRIER AIR MOVING INTO THE AREA
FROM THE WEST. THIS WILL LEAD TO DIMINISHING RAIN CHANCES AND
DECREASING CLOUD COVERAGE TUESDAY NIGHT. MOST TAF SITES WILL BE
MOSTLY CLEAR PRIOR TO MIDNIGHT. NW SFC WINDS WILL BE BLUSTERY LATE
TUESDAY INTO TUESDAY NIGHT WITH SUSTAINED WINDS 10-15 MPH AND GUSTS
20-25 MPH. THE BLUSTERY CONDITIONS WILL SLOWLY ABATE ON WEDNESDAY.
VFR CONDITIONS WILL PERSIST TUESDAY NIGHT THROUGH LATE THURSDAY. AN
APPROACHING LOW PRESSURE SYSTEM WILL BRING A THREAT FOR SUB-VFR
CONDITIONS TO CENTRAL NC AS EARLY AS THURSDAY NIGHT BUT MORE LIKELY
FRIDAY INTO SATURDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS/SMITH
SHORT TERM...MLM
LONG TERM...MLM
AVIATION...CBL/WSS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
600 AM EDT SUN MAR 23 2014
.SYNOPSIS...
A COLD FRONT MOVING SOUTHEAST ACROSS THE AREA...WILL BRING SHOWERS
AND ISOLATED THUNDERSTORMS THIS AFTERNOON AND EVENING...WITH COOLER
TEMPERATURES OVERNIGHT INTO MONDAY. AN INTENSIFYING LOW PRESSURE
SYSTEM WILL TRACK NORTHEAST AND OFFSHORE OF THE AREA ON TUESDAY.
A CHILLY RAIN IS EXPECTED LATE ON TUESDAY AS A COLD FRONT PUSHES
ACROSS THE COAST...FOLLOWED BY COOL HIGH PRESSURE THROUGH MIDWEEK.
A WARMING TREND IS EXPECTED INTO NEXT WEEKEND AS THE HIGH MIGRATES
OFFSHORE NEAR BERMUDA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 6 AM SUNDAY...DENSE FOG WAS WIDESPREAD PRIOR TO DAYBREAK AND
AN ADVISORY RUNS UNTIL 8AM FOR VISIBILITIES LESS THAN A QUARTER
MILE. NIGHT-TIME IMAGERY HAS SHOWN THE FOG EXPANDING TO THE NE
OVERSPREADING THE COAST AND NEAR SHORE WATERS. ELEVATED DEWPOINTS
WILL CONTINUE TO SUPPORT AREAS OF FOG NEAR THE COAST SUBJECTED TO
CHILLY OCEAN AIR. AS THE FOG BREAKS THROUGH MORNING...PARTLY SUNNY
SKIES WILL PREVAIL WITH THICKENING CIRRUS THEREAFTER. SIGNIFICANT
CHANGES NOT NEEDED AT THIS TIME. PREVIOUS MORNING DISCUSSION.
A COLD FRONT NW OF THE AREA WILL PRESS SE INTO THE REGION TODAY.
A LARGE RANGE IN MAXIMUM TEMPERATURES IS EXPECTED TODAY...RANGING
FROM THE LOWER 60S ACROSS OUR VERY NORTHERN AND WESTERN TIER...TO
THE UPPER 70S MAYBE EVEN 80 ACROSS OUR SC INTERIOR THIS AFTERNOON
PRIOR TO FRONTAL PASSAGE.
LOW-LEVEL WIND CONVERGENCE MAY BECOME STRONG IN THE AFTERNOON WITH
ALIGNMENT OF THE SEA BREEZE BOUNDARY AND THE SURFACE FRONT...BOTH
OF WHICH WILL INTERACT NEAR THE COAST. LOW-LEVEL WIND TRAJECTORIES
OF W-NW TODAY WILL KEEP THESE SURFACE BOUNDARIES FASTENED NEAR THE
COAST...AND IT IS HERE ALONG THIS CORRIDOR OF ENHANCED LOWER
TROPOSPHERIC OMEGA THAT WE HAVE INCLUDED A SLIGHT CHANCE OF A
TSTM...FAVORED MIDDLE THROUGH LATE AFTERNOON.
DEEPER MOISTURE TONIGHT IN POST FRONTAL FLOW MAY BRING LINGERING
STRATIFORM RAIN THROUGH EVENING WITH TAPERING PCPN LATE AS DRY MID
LEVEL AIR PUNCHES IN FROM THE NW.
DENSE FOG ADVISORY NEEDED EARLY THIS MORNING FOR SEVERELY REDUCED
VSBYS THROUGH 800 AM.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...THE SHORT TERM GUIDANCE REMAINS IN TWO CAMPS THIS
MORNING WITH THE GFS BEING CONSISTENT WITH A DECENT RAIN EVENT FOR
LATE MONDAY INTO TUESDAY. THE NAM CONTINUES WITH A MORE SOUTH AND
EAST DEPICTION. WILL CONTINUE TO OPT FOR THE FORMER SOLUTION WHICH
MATCHES CONSISTENCY/CONTINUITY BETTER. INTERESTING TO NOTE THE
OPERATIONAL ECMWF IS ALMOST IN THE MIDDLE OF THE TWO SOLUTIONS.
POPS HAVE BEEN FINE TUNED TO MATCH THE MORE ROBUST GFS AND ADJACENT
OFFICES. I HAVE ALSO ADDED DRIZZLE TO THE FORECAST FOR LATE TUESDAY
AS ONLY LOW LEVEL CONVERGENCE VIA THE STRONG NORTHERLY FLOW WILL BE
THE IMPETUS FOR RAINFALL. STILL CANNOT TOTALLY RULE OUT A LITTLE
SNOW MIXED IN WITH THE RAIN INITIALLY BUT THE BEST LIFT SEEMS TO
OCCUR A BIT LATER IN THE MORNING. WE REALLY NEED TO THREAD THE
NEEDLE WITH PRE DAWN LOWS SANS ANY DAYTIME WARMING TO SEE SNOW.
FINALLY I HAVE RAISED WEDNESDAY MORNING LOWS AS THE BOUNDARY LAYER
SHOULD REMAIN WELL MIXED PRECLUDING A MORE DRAMATIC DROP.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 330 AM SUNDAY...MEDIUM RANGE GUIDANCE REMAINS RELATIVELY STABLE
WITH A COUPLE OF DRY ALBEIT...COLD DAYS FOR WEDNESDAY AND
THURSDAY. A LITTLE VARIABILITY IN THE NUMBERS MAINLY FOCUSING ON
LOWS BOTH DAYS WILL BE AN ISSUE FOR THE AGRICULTURE COMMUNITY. I
HAVE TRIED TO FIND WAYS TO KEEP SURFACE TEMPERATURES UP FOR
THURSDAY MORNING BUT WITH HIGH PRESSURE DRIFTING OVERHEAD...AND A
VERY DRY COLUMN...PW IS DOWN TO 0.20 INCHES...UPPER 20S TO LOWER
30S APPEAR LIKELY. IN FACT I HAVE DROPPED THE FORECAST LOWS ABOUT
A DEGREE FOR THURSDAY MORNING. STRONG MARCH SUN SHOULD ALLOW
TEMPERATURES TO REACH 50 OR CLOSE WEDNESDAY. FRIDAY AND SATURDAY
CONTINUE TO FEATURE LOWER CHANCE POPS WITH AN APPROACHING SYSTEM
AND TEMPERATURES NEAR OR JUST ABOVE CLIMATOLOGY.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...VSBYS WILL BE A CONCERN INTO THE EARLY MORNING HOURS AS
CLEARING SKIES AND ELEVATED DEWPOINTS FAVOR FOG DEVELOPMENT. TIMING
THE ONSET WILL BE THE BIGGEST CHALLENGE...AS CLOUDS HAVE LINGERED
OVER THE COASTAL TERMS LONGER THAN ORIGINALLY EXPECTED. STILL AGREE
WITH THE HRRR THAT AREAS OF MVFR/IFR VSBYS WILL DEVELOP ACROSS THE
CWA AS WE GET CLOSER TO DAYBREAK. IN PARTICULAR...DEWPOINTS AROUND
60 DEG ON THE COAST MEAN THAT ONCE CONDITIONS BECOME MOSTLY CLEAR
AND CALM...VSBYS SHOULD DROP FAIRLY RAPIDLY.
AN APPROACHING COLD FRONT WILL SLOWLY MOVE THROUGH OUR CWA LATER
THIS MORNING. LIGHT NORTHERLY WINDS EARLY WILL STRENGTHEN TO 10-15
KTS WITH HIGHER GUSTS THIS AFTERNOON/EVENING. RAIN WILL ALSO MOVE
INTO OUR AREA AFTER 18Z FROM WEST TO EAST...ACCOMPANIED BY PERIODS
OF MVFR CIGS WITH SHALLOW NORTHERLY FLOW BENEATH WESTERLY FLOW
ALOFT. FCST SOUNDINGS INDICATE THESE LOW CIGS SHOULD BE FAIRLY
SHORT-LIVED...AND CONDITIONS WILL IMPROVE TO VFR AT ALL TERMS BY 06Z
MONDAY AS DRIER AIR ADVECTS INTO THE REGION.
EXTENDED OUTLOOK...VFR ON MONDAY. A COASTAL LOW WILL BRING RAIN AND
MVFR/IFR CIGS TO OUR CWA BEGINNING EARLY TUESDAY. VFR WEDNESDAY AND
THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6 AM SUNDAY...DETERIORATING CONDITIONS AS A COLD FRONT
CROSSES THE WATERS LATER TODAY AND HIGH PRESSURE BUILDS IN
TONIGHT. WINDS WILL REACH 25 KT LATE THIS AFTERNOON TO EARLY
EVENING AND AN ADVISORY WILL EXTEND FROM 6PM THIS EVENING TO
MIDDAY MONDAY. THE SEA SPECTRUM WILL CONSIST OF ESE WAVES 2-3 FEET
EVERY 12 SECONDS AND S WAVES EVERY 5-6 SECONDS BUILDING TO 2 TO 4
FEET BY LATE THIS AFTERNOON. A FEW TSTMS ARE POSSIBLE OVER THE
WATERS AS A COLD FRONT MOVES THROUGH. LIGHT WINDS THROUGH MUCH OF
MORNING...WITH RAMPING UP OF WINDS IN THE AFTERNOON.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...WINDS WILL INITIALLY BE FROM THE NORTHEAST IN A
RANGE OF 20-25 KNOTS BUT WILL STEADILY DROP THROUGH THE EVENING
HOURS MONDAY AS THE GRADIENT RELAXES. THE DIRECTION WILL ALSO VEER
TO THE EAST. THE EMPHASIS THEN SHIFTS LITERALLY AND FIGURATIVELY TO
TUESDAY AFTERNOON THROUGH WEDNESDAY MORNING.
WINDS WILL INCREASE AS STRONG COLD AIR ADVECTION COMMENCES AND WITH
LOW LEVEL WIND FIELDS VIA THE GFS ON THE ORDER OF 30-40 KNOTS
THROUGH 850MB...STILL CANNOT RULE OUT A GALE WARNING ESPECIALLY
CONSIDERING GUSTS. CERTAINLY A STRONG SMALL CRAFT ADVISORY WILL BE
WARRANTED. SIGNIFICANT SEAS WILL GENERALLY FOLLOW THE WINDS WITH THE
SAVING GRACE FOR THE LATER TIMES ALLOWING THE HIGHEST VALUES TO BE
CONCENTRATED MORE OFFSHORE.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 330 AM SUNDAY...WIND AND SUBSEQUENTLY SEAS WILL BE ON THE
DECLINE SLOWLY WEDNESDAY...MORE APPRECIABLY WEDNESDAY EVENING.
THIS AS HIGH PRESSURE MOVES OVERHEAD. HEADLINES SHOULD BE ABLE TO
BE REMOVED BY MIDDAY WEDNESDAY OR SHORTLY THEREAFTER. WINDS
DIMINISH TO TEN KNOTS OR LESS BY THURSDAY MORNING. SIGNIFICANT
SEAS FOLLOW IN SHORT ORDER TO 2-3 FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...DENSE FOG ADVISORY UNTIL 8 AM EDT THIS MORNING FOR SCZ017-023-
024-032-033-039-053>056.
NC...DENSE FOG ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NCZ087-096-
099-105>110.
MARINE...DENSE FOG ADVISORY UNTIL NOON EDT TODAY FOR AMZ250-252-254-256.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO NOON EDT MONDAY
FOR AMZ250-252-254-256.
&&
$$
SYNOPSIS...MJC
NEAR TERM...MJC
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...HDL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
353 AM EDT SUN MAR 23 2014
.SYNOPSIS...
A COLD FRONT MOVING SOUTHEAST ACROSS THE AREA...WILL BRING SHOWERS
AND ISOLATED THUNDERSTORMS THIS AFTERNOON AND EVENING...WITH COOLER
TEMPERATURES OVERNIGHT INTO MONDAY. AN INTENSIFYING LOW PRESSURE
SYSTEM WILL TRACK NORTHEAST AND OFFSHORE OF THE AREA ON TUESDAY.
A CHILLY RAIN IS EXPECTED LATE ON TUESDAY AS A COLD FRONT PUSHES
ACROSS THE COAST...FOLLOWED BY COOL HIGH PRESSURE THROUGH MIDWEEK.
A WARMING TREND IS EXPECTED INTO NEXT WEEKEND THE HIGH MIGRATES
OFFSHORE NEAR BERMUDA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM SUNDAY...A COLD FRONT NW OF THE AREA WILL PRESS SE
INTO THE REGION TODAY. A LARGE RANGE IN MAXIMUM TEMPERATURES IS
EXPECTED AS A RESULT...RANGING FROM THE LOWER 60S ACROSS OUR VERY
NORTHERN AND WESTERN TIER...TO THE UPPER 70S MAYBE EVEN 80 ACROSS
OUR SC INTERIOR THIS AFTERNOON PRIOR TO FRONTAL PASSAGE.
LOW-LEVEL WIND CONVERGENCE MAY BECOME STRONG IN THE AFTERNOON WITH
ALIGNMENT OF THE SEA BREEZE BOUNDARY AND THE SURFACE FRONT...BOTH
OF WHICH WILL INTERACT NEAR THE COAST. LOW-LEVEL WIND TRAJECTORIES
OF W-NW TODAY WILL KEEP THESE SURFACE BOUNDARIES FASTENED NEAR THE
COAST...AND IT IS HERE ALONG THIS CORRIDOR OF ENHANCED LOWER
TROPOSPHERIC OMEGA THAT WE HAVE INCLUDED A SLIGHT CHANCE OF A
TSTM...FAVORED MIDDLE THROUGH LATE AFTERNOON.
DEEPER MOISTURE TONIGHT IN POST FRONTAL FLOW MAY BRING LINGERING
STRATIFORM RAIN THROUGH EVENING WITH TAPERING PCPN LATE AS DRY MID
LEVEL AIR PUNCHES IN FROM THE NW.
DENSE FOG ADVISORY NEEDED EARLY THIS MORNING FOR SEVERELY REDUCED
VSBYS THROUGH 800 AM.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...THE SHORT TERM GUIDANCE REMAINS IN TWO CAMPS THIS
MORNING WITH THE GFS BEING CONSISTENT WITH A DECENT RAIN EVENT FOR
LATE MONDAY INTO TUESDAY. THE NAM CONTINUES WITH A MORE SOUTH AND
EAST DEPICTION. WILL CONTINUE TO OPT FOR THE FORMER SOLUTION WHICH
MATCHES CONSISTENCY/CONTINUITY BETTER. INTERESTING TO NOTE THE
OPERATIONAL ECMWF IS ALMOST IN THE MIDDLE OF THE TWO SOLUTIONS.
POPS HAVE BEEN FINE TUNED TO MATCH THE MORE ROBUST GFS AND ADJACENT
OFFICES. I HAVE ALSO ADDED DRIZZLE TO THE FORECAST FOR LATE TUESDAY
AS ONLY LOW LEVEL CONVERGENCE VIA THE STRONG NORTHERLY FLOW WILL BE
THE IMPETUS FOR RAINFALL. STILL CANNOT TOTALLY RULE OUT A LITTLE
SNOW MIXED IN WITH THE RAIN INITIALLY BUT THE BEST LIFT SEEMS TO
OCCUR A BIT LATER IN THE MORNING. WE REALLY NEED TO THREAD THE
NEEDLE WITH PRE DAWN LOWS SANS ANY DAYTIME WARMING TO SEE SNOW.
FINALLY I HAVE RAISED WEDNESDAY MORNING LOWS AS THE BOUNDARY LAYER
SHOULD REMAIN WELL MIXED PRECLUDING A MORE DRAMATIC DROP.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 330 AM SUNDAY...MEDIUM RANGE GUIDANCE REMAINS RELATIVELY STABLE
WITH A COUPLE OF DRY ALBEIT...COLD DAYS FOR WEDNESDAY AND
THURSDAY. A LITTLE VARIABILITY IN THE NUMBERS MAINLY FOCUSING ON
LOWS BOTH DAYS WILL BE AN ISSUE FOR THE AGRICULTURE COMMUNITY. I
HAVE TRIED TO FIND WAYS TO KEEP SURFACE TEMPERATURES UP FOR
THURSDAY MORNING BUT WITH HIGH PRESSURE DRIFTING OVERHEAD...AND A
VERY DRY COLUMN...PW IS DOWN TO 0.20 INCHES...UPPER 20S TO LOWER
30S APPEAR LIKELY. IN FACT I HAVE DROPPED THE FORECAST LOWS ABOUT
A DEGREE FOR THURSDAY MORNING. STRONG MARCH SUN SHOULD ALLOW
TEMPERATURES TO REACH 50 OR CLOSE WEDNESDAY. FRIDAY AND SATURDAY
CONTINUE TO FEATURE LOWER CHANCE POPS WITH AN APPROACHING SYSTEM
AND TEMPERATURES NEAR OR JUST ABOVE CLIMATOLOGY.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...VSBYS WILL BE A CONCERN INTO THE EARLY MORNING HOURS AS
CLEARING SKIES AND ELEVATED DEWPOINTS FAVOR FOG DEVELOPMENT. TIMING
THE ONSET WILL BE THE BIGGEST CHALLENGE...AS CLOUDS HAVE LINGERED
OVER THE COASTAL TERMS LONGER THAN ORIGINALLY EXPECTED. STILL AGREE
WITH THE HRRR THAT AREAS OF MVFR/IFR VSBYS WILL DEVELOP ACROSS THE
CWA AS WE GET CLOSER TO DAYBREAK. IN PARTICULAR...DEWPOINTS AROUND
60 DEG ON THE COAST MEAN THAT ONCE CONDITIONS BECOME MOSTLY CLEAR
AND CALM...VSBYS SHOULD DROP FAIRLY RAPIDLY.
AN APPROACHING COLD FRONT WILL SLOWLY MOVE THROUGH OUR CWA LATER
THIS MORNING. LIGHT NORTHERLY WINDS EARLY WILL STRENGTHEN TO 10-15
KTS WITH HIGHER GUSTS THIS AFTERNOON/EVENING. RAIN WILL ALSO MOVE
INTO OUR AREA AFTER 18Z FROM WEST TO EAST...ACCOMPANIED BY PERIODS
OF MVFR CIGS WITH SHALLOW NORTHERLY FLOW BENEATH WESTERLY FLOW
ALOFT. FCST SOUNDINGS INDICATE THESE LOW CIGS SHOULD BE FAIRLY
SHORT-LIVED...AND CONDITIONS WILL IMPROVE TO VFR AT ALL TERMS BY 06Z
MONDAY AS DRIER AIR ADVECTS INTO THE REGION.
EXTENDED OUTLOOK...VFR ON MONDAY. A COASTAL LOW WILL BRING RAIN AND
MVFR/IFR CIGS TO OUR CWA BEGINNING EARLY TUESDAY. VFR WEDNESDAY AND
THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM SUNDAY...DETERIORATING CONDITIONS AS A COLD FRONT
CROSSES THE WATERS LATER TODAY AND HIGH PRESSURE BUILDS IN TONIGHT.
WINDS WILL REACH 25 KT LATE THIS AFTERNOON TO EARLY EVENING AND AN
ADVISORY WILL EXTEND FROM 6PM THIS EVENING TO MIDDAY MONDAY. THE
SEA SPECTRUM WILL CONSIST OF ESE WAVES 2-3 FEET EVERY 12 SECONDS
AND S WAVES EVERY 5-6 SECONDS BUILDING TO 2 TO 4 FEET BY LATE THIS
AFTERNOON. A FEW TSTMS ARE POSSIBLE OVER THE WATERS AS A COLD
FRONT MOVES THROUGH. LIGHT WINDS THROUGH MUCH OF MORNING...WITH
RAMPING UP OF WINDS IN THE AFTERNOON.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...WINDS WILL INITIALLY BE FROM THE NORTHEAST IN A
RANGE OF 20-25 KNOTS BUT WILL STEADILY DROP THROUGH THE EVENING
HOURS MONDAY AS THE GRADIENT RELAXES. THE DIRECTION WILL ALSO VEER
TO THE EAST. THE EMPHASIS THEN SHIFTS LITERALLY AND FIGURATIVELY TO
TUESDAY AFTERNOON THROUGH WEDNESDAY MORNING.
WINDS WILL INCREASE AS STRONG COLD AIR ADVECTION COMMENCES AND WITH
LOW LEVEL WIND FIELDS VIA THE GFS ON THE ORDER OF 30-40 KNOTS
THROUGH 850MB...STILL CANNOT RULE OUT A GALE WARNING ESPECIALLY
CONSIDERING GUSTS. CERTAINLY A STRONG SMALL CRAFT ADVISORY WILL BE
WARRANTED. SIGNIFICANT SEAS WILL GENERALLY FOLLOW THE WINDS WITH THE
SAVING GRACE FOR THE LATER TIMES ALLOWING THE HIGHEST VALUES TO BE
CONCENTRATED MORE OFFSHORE.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 330 AM SUNDAY...WIND AND SUBSEQUENTLY SEAS WILL BE ON THE
DECLINE SLOWLY WEDNESDAY...MORE APPRECIABLY WEDNESDAY EVENING.
THIS AS HIGH PRESSURE MOVES OVERHEAD. HEADLINES SHOULD BE ABLE TO
BE REMOVED BY MIDDAY WEDNESDAY OR SHORTLY THEREAFTER. WINDS
DIMINISH TO TEN KNOTS OR LESS BY THURSDAY MORNING. SIGNIFICANT
SEAS FOLLOW IN SHORT ORDER TO 2-3 FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...DENSE FOG ADVISORY UNTIL 8 AM EDT THIS MORNING FOR SCZ017-023-
024-032-033-039-053>056.
NC...DENSE FOG ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NCZ087-096-
099-105>110.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO NOON EDT MONDAY
FOR AMZ250-252-254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...MJC
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...MJC/BJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
204 AM EDT SUN MAR 23 2014
.SYNOPSIS...
A COLD FRONT MOVING SOUTHEAST ACROSS THE AREA...WILL BRING SHOWERS
AND ISOLATED THUNDERSTORMS THIS AFTERNOON AND EVENING...WITH COOLER
TEMPERATURES OVERNIGHT INTO MONDAY. AN INTENSIFYING LOW PRESSURE
SYSTEM WILL TRACK NORTHEAST AND OFFSHORE OF THE AREA ON TUESDAY.
A CHILLY RAIN IS EXPECTED LATE ON TUESDAY AS A COLD FRONT PUSHES
ACROSS THE COAST...FOLLOWED BY COOL HIGH PRESSURE THROUGH MIDWEEK.
A WARMING TREND IS EXPECTED INTO NEXT WEEKEND THE HIGH MIGRATES
OFFSHORE NEAR BERMUDA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 PM SATURDAY...CONVECTION HAS DWINDLED TO JUST AN ISOLATED
SHOWER OR TWO LATE THIS EVE...NEAR IMMEDIATE COAST AND FAR SOUTHERN
PORTIONS OF THE CWA. AS SKIES CONTINUE TO AT LEAST PARTIALLY
CLEAR...EXPECT FOG AND STRATUS TO SETTLE IN AFTER MIDNIGHT.
PREVIOUS DISCUSSION FROM 700 PM...MOISTURE POOLING AHEAD OF AN
APPROACHING COLD FRONT FROM THE NW AND N AND A WEAK SURFACE WAVE HAS
BEEN IMPRESSIVE. HELPED ALONG BY THE PASSAGE OF A SEABREEZE...
DEWPOINTS HAVE SURGED TO NEAR 60 DEGREES...HIGHEST ACROSS SOUTHERN
PORTIONS OF THE FORECAST AREA AND UP ALONG THE CAPE FEAR COAST.
ENHANCED BY SOME WEAK MID-LEVEL SHORTWAVE ENERGY...CONVECTION HAS
NOT ONLY BLOSSOMED BUT BEEN PERSISTENT...ESPECIALLY ACROSS HORRY
COUNTY AND TRAILING BACK ACROSS THE SOUTHERN PEE DEE. CELLS WERE
TRAINING FOR A GOOD WHILE AND MAY HAVE LAID DOWN AS MUCH AS AN INCH
OF RAIN IN SOME COMMUNITIES PER RADAR ESTIMATES. THIS CONVECTION WAS
WORKING ITS WAY TO THE NE AND POPS HAVE BEEN INCREASED TO LIKELY
AHEAD OF THIS LARGE AREA OF SHOWERS. DESPITE THE RATHER SHALLOW
NATURE OF THE CONVECTION...SEVERAL LIGHTNING STRIKES HAVE BEEN NOTED
THROUGH THE LATER AFTERNOON AND EARLY EVE. HIGHER RESOLUTION MODELS
HAVE LATCHED ONTO THE ONGOING CONVECTION AND TAKE IT UP ALONG THE
COAST AND EVENTUALLY OFFSHORE THROUGH THE LATE EVE HOURS.
A COLD FRONT SHOULD BE SLIPPING THROUGH THE FORECAST AREA DURING THE
LATE NIGHT HOURS AND ON SUN. WIND FIELDS WILL BE RATHER WEAK AND
GIVEN HIGHER DEWPOINTS HAVE SURGED ACROSS THE FORECAST AREA...EXPECT
FOG AND OR STRATUS WILL DEVELOP OVERNIGHT. FOG MAY BECOME AT LEAST
LOCALLY DENSE GIVEN THE HEAVY RAIN THAT HAS FALLEN OR IS EXPECTED
THIS EVE ACROSS PORTIONS OF THE AREA. AT THIS TIME...WILL INCLUDE
PATCHY TO AREAS OF FOG INTO SUN MORNING.
CLOUDS AND HIGHER DEWPOINTS SHOULD MAKE FOR A WARMER NIGHT THAN LAST
NIGHT AND LOWER TO MID 50S SHOULD BE MOST COMMON.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
AS OF 300 PM SATURDAY...WE WILL MANAGE ONE LAST DAY OF SEASONABLE TO
SLIGHTLY WARM TEMPS ON SUNDAY...DEPENDING ON HOW QUICKLY THE
BOUNDARY MOVES THROUGH. BUT COME THROUGH IT WILL AND THE ENSUING
COLD ADVECTION WILL BE TREMENDOUS...OUR MIDDAY 850MB TEMPS OF 8C
FALLING TO -4 TO -8C BY 12Z MONDAY (SOUTH TO NORTH). MOISTURE FLUX
AHEAD OF THE FRONT APPEARS TO BE MINIMAL SO RAIN CHANCES WILL
GENERALLY COME FOLLOWING FROPA IN THE UNDERCUTTING BUT ALSO BE
RATHER SHORT-LIVED SINCE THE COLUMN DRIES OUT DRAMATICALLY BY SUNDAY
NIGHT. THE NEW AIRMASS WILL ALLOW TEMPERATURES TO DROP INTO THE 30S
FOR THE FIRST TIME DURING THE RECENTLY STARTED OFFICIAL GROWING
SEASON...BUT A CONTINUED NORTHERLY BREEZE WILL KEEP THINGS MIXED
WELL ENOUGH TO PREVENT FREEZE. FROST MAY NEED TO BE CONSIDERED
THOUGH. MONDAY BRINGS HIGH TEMPS SOME 15 DEGREES BELOW CLIMO EVEN
THOUGH THE CAA MERCIFULLY SHUTS DOWN. AN INTERESTING YET UNCERTAIN
ASPECT OF THE LATE PART OF THE FORECAST PERIOD IS THE SPEED AT WHICH
MOISTURE MANAGES TO RETURN FROM THE SOUTH AS LOW PRESSURE DEVELOPS
OVER FLORIDA...THE VERY SAME LOW THAT MAY END UP BEING AN IMPRESSIVE
BOMB OFF NORTHEAST COAST. THIS IS OF RELATIVELY HEIGHTENED
IMPORTANCE SINCE THERMAL PROFILES MAY SUPPORT SOME WINTRY BUT NON
ACCUMULATING PRECIP...ALTHOUGH THEY LOOK A LITTLE WARMER THAN
PREVIOUS. ADDITIONALLY THE WRF SUPPRESSES EVERYTHING TO OUR SOUTH.
GIVEN THE STRENGTH OF THE WEDGE IN PLACE THIS SOLUTION APPEARS MUCH
MORE APPEALING. FOR THE SAKE OF CONTINUITY HAVE NOT REMOVED THE SNOW
BUT HAVE LOWERED POPS.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 300 PM SATURDAY...MID LEVEL PATTERN WILL REMAIN HIGHLY
AMPLIFIED DURING THE PERIOD. ON TUE RAPIDLY DEEPENING LOW PRESSURE
EAST OF SAVANNAH IS LIFTED NORTHEAST BY MID LEVEL TROUGH. DEEP DRY
AIR SPREADS IN FROM THE WEST TUE BRINGING AN END TO SIGNIFICANT
PRECIP BY MIDDAY. THE 5H TROUGH EVENTUALLY BECOMES NEGATIVELY TILTED
BUT NOT UNTIL THE LOW IS WELL NORTH OF THE AREA. EXITING DEEPENING
LOW AND BUILDING ARCTIC HIGH IN CONJUNCTION WITH THE NEGATIVELY
TILTED TROUGH WILL PRODUCE STRONG COLD ADVECTION TUE NIGHT. 850
TEMPS DROP CLOSE TO -10C BY WED MORNING...ENSURING LOWS WELL BELOW
CLIMO TUE NIGHT DESPITE STRONG MIXING.
COLD ADVECTION WEAKENS DURING WED AS THE CENTER OF THE HIGH DRIFTS
EAST. LATE MARCH SUNSHINE WILL HELP OFFSET SOME OF THE COLD
ADVECTION BUT HIGHS WILL STILL END UP BELOW CLIMO...BY AS MUCH AS 20
DEGREES. HIGHS WED MAY NOT REACH 50 IN MOST AREAS! ALTHOUGH WED
NIGHT WILL NOT BE A PERFECT RADIATIONAL COOLING NIGHT IT WILL BE
CLOSE. TEMPS BELOW FREEZING ARE LIKELY IN MOST AREAS WITH INLAND
AREAS DROPPING INTO THE 20S. AIR MASS MODIFIES THU/THU NIGHT AS THE
HIGH SHIFTS OFF THE COAST AND WEAK MID LEVEL RIDGE BUILDS. HIGHS
WILL STILL RUN BELOW CLIMO...ABOUT 10 DEGREES BELOW...WITH LOWS
RUNNING CLOSE TO CLIMO.
PRECIP CHANCES INCREASE FOR THE END OF THE PERIOD WITH POTENTIAL
COASTAL TROUGH DEVELOPING THU NIGHT INTO FRI. NEXT MID LEVEL TROUGH
MOVES INTO THE EASTERN CONUS AS THE PERIOD ENDS. SURFACE LOW
ASSOCIATED WITH THE TROUGH WILL MOVE INTO THE NORTHEAST WITH
TRAILING COLD FRONT CROSSING CAROLINAS DURING SAT. WILL MAINTAIN
SILENT POP SAT FOR CONVECTION WITH FROPA. TEMPERATURES NEAR CLIMO
FOR THE END OF THE PERIOD.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...VSBYS WILL BE A CONCERN INTO THE EARLY MORNING HOURS AS
CLEARING SKIES AND ELEVATED DEWPOINTS FAVOR FOG DEVELOPMENT. TIMING
THE ONSET WILL BE THE BIGGEST CHALLENGE...AS CLOUDS HAVE LINGERED
OVER THE COASTAL TERMS LONGER THAN ORIGINALLY EXPECTED. STILL AGREE
WITH THE HRRR THAT AREAS OF MVFR/IFR VSBYS WILL DEVELOP ACROSS THE
CWA AS WE GET CLOSER TO DAYBREAK. IN PARTICULAR...DEWPOINTS AROUND
60 DEG ON THE COAST MEAN THAT ONCE CONDITIONS BECOME MOSTLY CLEAR
AND CALM...VSBYS SHOULD DROP FAIRLY RAPIDLY.
AN APPROACHING COLD FRONT WILL SLOWLY MOVE THROUGH OUR CWA LATER
THIS MORNING. LIGHT NORTHERLY WINDS EARLY WILL STRENGTHEN TO 10-15
KTS WITH HIGHER GUSTS THIS AFTERNOON/EVENING. RAIN WILL ALSO MOVE
INTO OUR AREA AFTER 18Z FROM WEST TO EAST...ACCOMPANIED BY PERIODS
OF MVFR CIGS WITH SHALLOW NORTHERLY FLOW BENEATH WESTERLY FLOW
ALOFT. FCST SOUNDINGS INDICATE THESE LOW CIGS SHOULD BE FAIRLY
SHORT-LIVED...AND CONDITIONS WILL IMPROVE TO VFR AT ALL TERMS BY 06Z
MONDAY AS DRIER AIR ADVECTS INTO THE REGION.
EXTENDED OUTLOOK...VFR ON MONDAY. A COASTAL LOW WILL BRING RAIN AND
MVFR/IFR CIGS TO OUR CWA BEGINNING EARLY TUESDAY. VFR WEDNESDAY AND
THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 PM SATURDAY...A LARGE CLUSTER OF SHOWERS AND
THUNDERSTORMS ACROSS THE OUTER CAPE FEAR WATERS WILL CONTINUE TO
MOVE E. ELSEWHERE...ANY SHOWERS WERE VERY ISOLATED.
PREVIOUS DISCUSSION FROM 700 PM...SURGE OF MOISTURE HAS WORKED
ITS WAY UP THE COAST AND BEEN ENHANCED BY THE SEABREEZE BOUNDARY
WHICH PUSHED WELL INLAND TODAY. AS A RESULT...NUMEROUS SHOWERS AND
ISOLATED THUNDERSTORMS DEVELOPED DURING THE AFTERNOON AND EARLY EVE.
THE HIGHER RESOLUTION MODELS AND RADAR TRENDS INDICATE THIS ACTIVITY
WILL MOVE OFFSHORE...MAINLY N OF BALD HEAD ISLAND LATER THIS EVE.
CONVECTION SHOULD BECOME MORE NUMEROUS NEAR AND ACROSS THE GULF
STREAM LATE TONIGHT. A COLD FRONT WILL APPROACH THE WATERS FROM THE
N AND NW TONIGHT AND SLOWLY MOVE ACROSS THE WATERS DURING SUN. S TO
SW WINDS WILL SHIFT TO THE NW AND NNW IN THE WAKE OF THIS FRONT. NO
APPRECIABLE GRADIENT OR SURGE IS EXPECTED AS THE GRADIENT REMAINS
SLACK AND THUS WIND SPEEDS WILL GENERALLY BE 10 KT OR LESS. SEAS
WILL BE A FUNCTION MAINLY OF AN EASTERLY 10 SECOND SWELL.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 PM SATURDAY...COLD FRONT TO MOVE ACROSS THE WATERS SUNDAY
AFTERNOON. THE ENSUING WIND SHIFT AND INCREASE IN SPEEDS WILL BUILD
SEAS AND STEEPEN WAVE FACES. A SMALL CRAFT ADVISORY SEEMS POSSIBLE
BUT THERE IS JUST ENOUGH UNCERTAINTY REGARDING TIMING AND WHICH
ZONES WILL MEET CRITERIA TO PRECLUDE ISSUANCE AT THIS TIME AFTER
COLLAB WITH ADJACENT WFOS. THE NE FLOW WILL REMAIN FOR THE BALANCE
OF THE PERIOD AS A VERY WINTRY HIGH PRESSURE WEDGE SETTLES IN EAST
OF THE APPALACHIANS. THIS WILL KEEP THE GRADIENT MODERATELY STRONG
ACROSS THE WATERS AND MANY ZONES WILL BE CLOSE TO SCEC/ADVISORY
CUTOFFS FOR BOTH WIND AND SEAS.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 300 PM SATURDAY...HEADLINES WILL LIKELY BE REQUIRED AT SOME
POINT TUE AND TUE NIGHT AS DEPARTING LOW STARTS TO DEEPEN. GRADIENT
OVER THE WATERS BECOMES PINCHED WITH OFFSHORE FLOW APPROACHING 30 KT
TUE NIGHT. GRADIENT SLOWLY WEAKENS WED AS HIGH PRESSURE DRIFTS EAST.
WINDS WILL REMAIN AROUND 20 KT FOR MUCH OF THE DAY BEFORE DROPPING
TO 15 TO 20 KT IN THE AFTERNOON. NORTHWEST FLOW SLOWLY VEERS TO
NORTHEAST WED NIGHT AND SPEEDS DROP TO 10 TO 15 KT AS THE CENTER OF
THE ELONGATED HIGH SHIFTS OVER THE EASTERN NC/VA. ONSHORE FLOW
DEVELOPS THU AS THE HIGH MOVES OFF THE COAST. WEAK GRADIENT WILL
KEEP SPEEDS 10 KT OR LESS. STRONG OFFSHORE FLOW WILL PRODUCE 4 TO 6
FT SEAS TUE AND TUE NIGHT. REDUCTION IN OFFSHORE FLOW WILL EQUATE TO
SEAS DROPPING TO 3 TO 5 FT FOR WED AND 2 TO 4 FT WED NIGHT AND THU.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MJC
NEAR TERM...MJC
SHORT TERM...MBB
LONG TERM...III
AVIATION...BJR/MJC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1154 AM CDT SUN MAR 23 2014
.UPDATE...
ISSUED AT 1146 AM CDT SUN MAR 23 2014
BOWMAN RADAR SHOWS BAND OF LIGHT PRECIPITATION APPROACHING THE FAR
SOUTHWEST. CURRENT PRECIPITATION TRENDS ON THIS LOOK GOOD. ABOUT
AN INCH OF SNOW SEEMS THE MOST FROM THIS BRUSHING IN SNOW.
ELSEWHERE TO THE NORTH AND EAST OF THIS AREA...LOOKS LIKE CLOUDS
ARE A BIT SLOW IN THICKENING...SO WILL TREND TOWARD MOSTLY SUNNY
FOR A GOOD PORTION OF THE AFTERNOON THERE.
UPDATE ISSUED AT 834 AM CDT SUN MAR 23 2014
BOWMAN RADAR STILL NOT SHOWING RETURNS SO FEEL COMFORTABLE IN A
LATE START IN THE PRECIP JUST BEFORE NOON SOUTHWEST. ADJUSTED
CLOUDS A BIT BUT OTHERWISE CURRENT FORECAST TRENDING WELL.
UPDATE ISSUED AT 638 AM CDT SUN MAR 23 2014
COLD SURFACE HIGH PRESSURE REMAINS OVER THE EASTERN DAKOTAS WITH
LOW PRESSURE SITUATED OVER THE NORTHERN ROCKIES AHEAD OF A
SHORTWAVE DROPPING SOUTHEAST INTO NORTHWEST MONTANA. MID AND HIGH
LEVEL CLOUDS ARE BEGINNING TO MOVE INTO WESTERN NORTH DAKOTA AHEAD
OF THE IMPULSE WITH LIGHT PRECIPITATION STILL OVER CENTRAL
PORTIONS OF MONTANA. CURRENT FORECAST LOOKS IN LINE WITH THE
LATEST 10Z RUC AND 09Z HRRR BRINGING A CHANCE OF LIGHT
PRECIPITATION INTO THE SOUTHWEST AFTER 16Z. MADE SOME MINOR SKY
COVER ADJUSTMENTS AND SLOWED THE UPWARD RISE IN TEMPERATURES
THROUGH MID MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 312 AM CDT SUN MAR 23 2014
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE CHANCES FOR
LIGHT SNOW MAINLY SOUTHWEST/FAR SOUTH CENTRAL TODAY/THIS EVENING.
CURRENTLY...RIDGE OF SURFACE HIGH PRESSURE EXTENDS FROM SOUTH
CENTRAL CANADA SOUTHEAST THROUGH EASTERN NORTH DAKOTA AND INTO THE
UPPER MISSISSIPPI VALLEY. LOW PRESSURE DEVELOPING ACROSS THE
WYOMING/MONTANA ROCKIES AHEAD OF AN EMBEDDED S/WV IMPULSE MOVING
EAST-SOUTHEAST TOWARDS THE IDAHO PANHANDLE. CLEAR SKIES AT THE
MOMENT ACROSS WEST AND CENTRAL NORTH DAKOTA RESULTING IN CHILLY
TEMPERATURES IN THE SINGLE DIGITS ABOVE TO LOWER TEENS. CLOUDS
WILL INCREASE 9-12Z ACROSS THE WEST AS BKN-OVC MID LEVEL CLOUDS
CONTINUE EAST ACROSS MONTANA AHEAD OF THE AFOREMENTIONED WAVE.
S/WV IMPULSE WILL CONTINUE EAST-SOUTHEAST ACROSS MONTANA THIS
MORNING AND AFTERNOON...THEN INTO SOUTH DAKOTA THIS EVENING.
SURFACE LOW PRESSURE ADVANCING AHEAD OF THIS FEATURE WILL DRAG AN
INVERTED SFC TROUGH AXIS ACROSS CENTRAL MONTANA THIS MORNING AND
THROUGH SOUTHWEST/FAR SOUTH CENTRAL ND THIS AFTERNOON AND EVENING.
MODEL SPREAD IS RATHER LARGE WHEN COMPARING THE 00Z/06Z NAM
(FARTHER NORTH WITH QPF) WITH THE LATEST 00Z GFS/EC/GEM (FARTHER
SOUTH). THE 00Z GFS/GEM BOTH SEEM A REASONABLE COMPROMISE BETWEEN
THE EC AND NAM...SO LEANED IN THERE DIRECTION. WWD PAINTS AN INCH
OF SNOW ACROSS MY FAR SOUTHWEST...AND IS WHAT OUR GRID METHODOLOGY
CALCULATED AS WELL. MOST IF NOT ALL PRECIPITATION SHOULD BE TO OUR
SOUTH BY LATE EVENING.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 312 AM CDT SUN MAR 23 2014
THE EARLY PORTION OF THE EXTENDED PERIOD REMAINS COLD WITH HIGHS
MAINLY IN THE 20S ON MONDAY AND TUESDAY. IT WILL BE BREEZY TO
WINDY ON MONDAY WITH A REINFORCING SHOT OF COLD AIR AND A STRONG
UPPER LEVEL JET OVER THE WESTERN DAKOTAS. TUESDAY IS EXPECTED TO
BE DRY AS THE COLD SURFACE HIGH TRACKS SOUTHEAST ACROSS THE AREA.
TEMPERATURES MODERATE ON WEDNESDAY AS A PACIFIC SYSTEM TRACKS
ACROSS THE NORTHERN ROCKIES AND INTO THE PLAINS. MODELS INDICATE
THERE WILL BE SCATTERED LIGHT PRECIP IN THE AREA WITH UPPER LEVEL
SUPPORT OVER THE NORTHERN PLAINS...BUT THE MAIN SURFACE
DEVELOPMENT IS EXPECTED TO DROP FROM THE NORTHERN HIGH
PLAINS...INTO THE CENTRAL PLAINS ON WEDNESDAY... THEN LIFT INTO
THE UPPER MIDWEST AND GREAT LAKES WEDNESDAY NIGHT INTO THURSDAY AS
YET ANOTHER COLD HIGH SETTLES OVER THE NORTHERN PLAINS KEEPING THE
BEST PRECIPITATION CHANCES JUST SOUTH OF THE AREA.
MODEL DIFFERENCES INCREASE AS WE HEAD INTO NEXT WEEKEND BUT AT
THIS TIME IT LOOKS LIKE A NICE WARM-UP COULD BE IN STORE FOR
SATURDAY AND POSSIBLY INTO SUNDAY BEFORE ANOTHER COOL DOWN LATE IN
THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1146 AM CDT SUN MAR 23 2014
MAINLY VFR CONDITIONS KISN-KMOT-KBIS-KJMS THROUGH THE 18Z TAF
PERIOD. LOW PRESSURE MOVING FROM MONTANA INTO THE CENTRAL PLAINS
TODAY WILL BRING SOME LIGHT SNOW AND LOWER CIGS TO THE FAR
SOUTHWEST THROUGH THE AFTERNOON HOURS SUNDAY. AT THIS TIME IT
LOOKS LIKE THE MAJORITY OF THE SNOW WILL REMAIN SOUTH OF KDIK BUT
MVFR CEILINGS WILL BRIEFLY IMPACT KDIK SUNDAY AFTERNOON.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...NH
LONG TERM...TWH
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
837 AM CDT SUN MAR 23 2014
.UPDATE...
ISSUED AT 834 AM CDT SUN MAR 23 2014
BOWMAN RADAR STILL NOT SHOWING RETURNS SO FEEL COMFORTABLE IN A
LATE START IN THE PRECIP JUST BEFORE NOON SOUTHWEST. ADJUSTED
CLOUDS A BIT BUT OTHERWISE CURRENT FORECAST TRENDING WELL.
UPDATE ISSUED AT 638 AM CDT SUN MAR 23 2014
COLD SURFACE HIGH PRESSURE REMAINS OVER THE EASTERN DAKOTAS WITH
LOW PRESSURE SITUATED OVER THE NORTHERN ROCKIES AHEAD OF A
SHORTWAVE DROPPING SOUTHEAST INTO NORTHWEST MONTANA. MID AND HIGH
LEVEL CLOUDS ARE BEGINNING TO MOVE INTO WESTERN NORTH DAKOTA AHEAD
OF THE IMPULSE WITH LIGHT PRECIPITATION STILL OVER CENTRAL
PORTIONS OF MONTANA. CURRENT FORECAST LOOKS IN LINE WITH THE
LATEST 10Z RUC AND 09Z HRRR BRINGING A CHANCE OF LIGHT
PRECIPITATION INTO THE SOUTHWEST AFTER 16Z. MADE SOME MINOR SKY
COVER ADJUSTMENTS AND SLOWED THE UPWARD RISE IN TEMPERATURES
THROUGH MID MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 312 AM CDT SUN MAR 23 2014
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE CHANCES FOR
LIGHT SNOW MAINLY SOUTHWEST/FAR SOUTH CENTRAL TODAY/THIS EVENING.
CURRENTLY...RIDGE OF SURFACE HIGH PRESSURE EXTENDS FROM SOUTH
CENTRAL CANADA SOUTHEAST THROUGH EASTERN NORTH DAKOTA AND INTO THE
UPPER MISSISSIPPI VALLEY. LOW PRESSURE DEVELOPING ACROSS THE
WYOMING/MONTANA ROCKIES AHEAD OF AN EMBEDDED S/WV IMPULSE MOVING
EAST-SOUTHEAST TOWARDS THE IDAHO PANHANDLE. CLEAR SKIES AT THE
MOMENT ACROSS WEST AND CENTRAL NORTH DAKOTA RESULTING IN CHILLY
TEMPERATURES IN THE SINGLE DIGITS ABOVE TO LOWER TEENS. CLOUDS
WILL INCREASE 9-12Z ACROSS THE WEST AS BKN-OVC MID LEVEL CLOUDS
CONTINUE EAST ACROSS MONTANA AHEAD OF THE AFOREMENTIONED WAVE.
S/WV IMPULSE WILL CONTINUE EAST-SOUTHEAST ACROSS MONTANA THIS
MORNING AND AFTERNOON...THEN INTO SOUTH DAKOTA THIS EVENING.
SURFACE LOW PRESSURE ADVANCING AHEAD OF THIS FEATURE WILL DRAG AN
INVERTED SFC TROUGH AXIS ACROSS CENTRAL MONTANA THIS MORNING AND
THROUGH SOUTHWEST/FAR SOUTH CENTRAL ND THIS AFTERNOON AND EVENING.
MODEL SPREAD IS RATHER LARGE WHEN COMPARING THE 00Z/06Z NAM
(FARTHER NORTH WITH QPF) WITH THE LATEST 00Z GFS/EC/GEM (FARTHER
SOUTH). THE 00Z GFS/GEM BOTH SEEM A REASONABLE COMPROMISE BETWEEN
THE EC AND NAM...SO LEANED IN THERE DIRECTION. WWD PAINTS AN INCH
OF SNOW ACROSS MY FAR SOUTHWEST...AND IS WHAT OUR GRID METHODOLOGY
CALCULATED AS WELL. MOST IF NOT ALL PRECIPITATION SHOULD BE TO OUR
SOUTH BY LATE EVENING.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 312 AM CDT SUN MAR 23 2014
THE EARLY PORTION OF THE EXTENDED PERIOD REMAINS COLD WITH HIGHS
MAINLY IN THE 20S ON MONDAY AND TUESDAY. IT WILL BE BREEZY TO
WINDY ON MONDAY WITH A REINFORCING SHOT OF COLD AIR AND A STRONG
UPPER LEVEL JET OVER THE WESTERN DAKOTAS. TUESDAY IS EXPECTED TO
BE DRY AS THE COLD SURFACE HIGH TRACKS SOUTHEAST ACROSS THE AREA.
TEMPERATURES MODERATE ON WEDNESDAY AS A PACIFIC SYSTEM TRACKS
ACROSS THE NORTHERN ROCKIES AND INTO THE PLAINS. MODELS INDICATE
THERE WILL BE SCATTERED LIGHT PRECIP IN THE AREA WITH UPPER LEVEL
SUPPORT OVER THE NORTHERN PLAINS...BUT THE MAIN SURFACE
DEVELOPMENT IS EXPECTED TO DROP FROM THE NORTHERN HIGH
PLAINS...INTO THE CENTRAL PLAINS ON WEDNESDAY... THEN LIFT INTO
THE UPPER MIDWEST AND GREAT LAKES WEDNESDAY NIGHT INTO THURSDAY AS
YET ANOTHER COLD HIGH SETTLES OVER THE NORTHERN PLAINS KEEPING THE
BEST PRECIPITATION CHANCES JUST SOUTH OF THE AREA.
MODEL DIFFERENCES INCREASE AS WE HEAD INTO NEXT WEEKEND BUT AT
THIS TIME IT LOOKS LIKE A NICE WARM-UP COULD BE IN STORE FOR
SATURDAY AND POSSIBLY INTO SUNDAY BEFORE ANOTHER COOL DOWN LATE IN
THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 834 AM CDT SUN MAR 23 2014
MAINLY VFR CONDITIONS THROUGH THE 12Z TAF PERIOD. LOW PRESSURE
MOVING FROM MONTANA INTO THE CENTRAL PLAINS TODAY WILL BRING SOME
LIGHT SNOW AND LOWER CIGS TO THE FAR SOUTHWEST LATE THIS MORNING
AND THROUGH THE AFTERNOON HOURS. AT THIS TIME IT LOOKS LIKE THE
MAJORITY OF THE SNOW WILL REMAIN SOUTH OF KDIK AND KBIS TAF SITES
ALONG WITH ANY MVFR CIGS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...NH
LONG TERM...TWH
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
638 AM CDT SUN MAR 23 2014
.UPDATE...
ISSUED AT 638 AM CDT SUN MAR 23 2014
COLD SURFACE HIGH PRESSURE REMAINS OVER THE EASTERN DAKOTAS WITH
LOW PRESSURE SITUATED OVER THE NORTHERN ROCKIES AHEAD OF A
SHORTWAVE DROPPING SOUTHEAST INTO NORTHWEST MONTANA. MID AND HIGH
LEVEL CLOUDS ARE BEGINNING TO MOVE INTO WESTERN NORTH DAKOTA AHEAD
OF THE IMPULSE WITH LIGHT PRECIPITATION STILL OVER CENTRAL
PORTIONS OF MONTANA. CURRENT FORECAST LOOKS IN LINE WITH THE
LATEST 10Z RUC AND 09Z HRRR BRINGING A CHANCE OF LIGHT
PRECIPITATION INTO THE SOUTHWEST AFTER 16Z. MADE SOME MINOR SKY
COVER ADJUSTMENTS AND SLOWED THE UPWARD RISE IN TEMPERATURES
THROUGH MID MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 312 AM CDT SUN MAR 23 2014
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE CHANCES FOR
LIGHT SNOW MAINLY SOUTHWEST/FAR SOUTH CENTRAL TODAY/THIS EVENING.
CURRENTLY...RIDGE OF SURFACE HIGH PRESSURE EXTENDS FROM SOUTH
CENTRAL CANADA SOUTHEAST THROUGH EASTERN NORTH DAKOTA AND INTO THE
UPPER MISSISSIPPI VALLEY. LOW PRESSURE DEVELOPING ACROSS THE
WYOMING/MONTANA ROCKIES AHEAD OF AN EMBEDDED S/WV IMPULSE MOVING
EAST-SOUTHEAST TOWARDS THE IDAHO PANHANDLE. CLEAR SKIES AT THE
MOMENT ACROSS WEST AND CENTRAL NORTH DAKOTA RESULTING IN CHILLY
TEMPERATURES IN THE SINGLE DIGITS ABOVE TO LOWER TEENS. CLOUDS
WILL INCREASE 9-12Z ACROSS THE WEST AS BKN-OVC MID LEVEL CLOUDS
CONTINUE EAST ACROSS MONTANA AHEAD OF THE AFOREMENTIONED WAVE.
S/WV IMPULSE WILL CONTINUE EAST-SOUTHEAST ACROSS MONTANA THIS
MORNING AND AFTERNOON...THEN INTO SOUTH DAKOTA THIS EVENING.
SURFACE LOW PRESSURE ADVANCING AHEAD OF THIS FEATURE WILL DRAG AN
INVERTED SFC TROUGH AXIS ACROSS CENTRAL MONTANA THIS MORNING AND
THROUGH SOUTHWEST/FAR SOUTH CENTRAL ND THIS AFTERNOON AND EVENING.
MODEL SPREAD IS RATHER LARGE WHEN COMPARING THE 00Z/06Z NAM
(FARTHER NORTH WITH QPF) WITH THE LATEST 00Z GFS/EC/GEM (FARTHER
SOUTH). THE 00Z GFS/GEM BOTH SEEM A REASONABLE COMPROMISE BETWEEN
THE EC AND NAM...SO LEANED IN THERE DIRECTION. WWD PAINTS AN INCH
OF SNOW ACROSS MY FAR SOUTHWEST...AND IS WHAT OUR GRID METHODOLOGY
CALCULATED AS WELL. MOST IF NOT ALL PRECIPITATION SHOULD BE TO OUR
SOUTH BY LATE EVENING.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 312 AM CDT SUN MAR 23 2014
THE EARLY PORTION OF THE EXTENDED PERIOD REMAINS COLD WITH HIGHS
MAINLY IN THE 20S ON MONDAY AND TUESDAY. IT WILL BE BREEZY TO
WINDY ON MONDAY WITH A REINFORCING SHOT OF COLD AIR AND A STRONG
UPPER LEVEL JET OVER THE WESTERN DAKOTAS. TUESDAY IS EXPECTED TO
BE DRY AS THE COLD SURFACE HIGH TRACKS SOUTHEAST ACROSS THE AREA.
TEMPERATURES MODERATE ON WEDNESDAY AS A PACIFIC SYSTEM TRACKS
ACROSS THE NORTHERN ROCKIES AND INTO THE PLAINS. MODELS INDICATE
THERE WILL BE SCATTERED LIGHT PRECIP IN THE AREA WITH UPPER LEVEL
SUPPORT OVER THE NORTHERN PLAINS...BUT THE MAIN SURFACE
DEVELOPMENT IS EXPECTED TO DROP FROM THE NORTHERN HIGH
PLAINS...INTO THE CENTRAL PLAINS ON WEDNESDAY... THEN LIFT INTO
THE UPPER MIDWEST AND GREAT LAKES WEDNESDAY NIGHT INTO THURSDAY AS
YET ANOTHER COLD HIGH SETTLES OVER THE NORTHERN PLAINS KEEPING THE
BEST PRECIPITATION CHANCES JUST SOUTH OF THE AREA.
MODEL DIFFERENCES INCREASE AS WE HEAD INTO NEXT WEEKEND BUT AT
THIS TIME IT LOOKS LIKE A NICE WARM-UP COULD BE IN STORE FOR
SATURDAY AND POSSIBLY INTO SUNDAY BEFORE ANOTHER COOL DOWN LATE IN
THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 638 AM CDT SUN MAR 23 2014
MAINLY VFR CONDITIONS THROUGH THE 12Z TAF PERIOD. LOW PRESSURE
MOVING FROM MONTANA INTO THE CENTRAL PLAINS TODAY WILL BRING SOME
LIGHT SNOW AND LOWER CIGS TO THE FAR SOUTHWEST AFTER 15Z THIS
MORNING AND THROUGH THE AFTERNOON HOURS. AT THIS TIME IT LOOKS LIKE
THE MAJORITY OF THE SNOW WILL REMAIN SOUTH OF KDIK AND KBIS TAF
SITES ALONG WITH ANY MVFR CIGS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...NH
LONG TERM...TWH
AVIATION...NH
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
115 AM EDT SUN MAR 23 2014
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTH ACROSS THE LOWER GREAT LAKES
OVERNIGHT. ARCTIC HIGH PRESSURE CENTERED OVER THE NORTHERN
PLAINS WILL BUILD OVER THE REGION ON SUNDAY AND MOVE EAST ON
MONDAY. WEAK LOW PRESSURE WILL TRACK ACROSS THE AREA ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
TEMPERATURES ARE STAYING UP AHEAD OF THE COLD FRONT. WINDS WERE
STILL LIGHT WEST AT RONDEAU ON THE NORTH SIDE OF LAKE ERIE AT 9 PM
SO THE FRONT IS TAKING ITS TIME. UPDATED THE HOURLY FORECAST
TEMPERATURES OVERNIGHT USING THE HRRR HOURLY TEMPERATURES WHICH
DEPICTED THE MILD TEMPS EARLY TONIGHT THEN A RELATIVELY QUICK DROP
IN TEMPS DURING THE EARLY MORNING HOURS AS THE ARCTIC AIR FILTERS
IN. RECALCULATED THE OVERNIGHT LOWS BASED ON THE HOURLY
TEMPERATURES AND CAME UP WITH MOSTLY UPPER TEENS/NEAR 20 IN THE
NORTH AND LOWER/MID 20S IN THE SOUTH. TEMPS CAN PROBABLY KEEP
DROPPING FOR A COUPLE OF HOURS EVEN AFTER DAYBREAK ON SUNDAY...THE
ARCTIC AIR IS IMPRESSIVE FOR LATE IN THE SEASON.
A NICE SHIELD OF HIGH CLOUDS ASSOCIATED WITH A QUICK MOVING SHORT
WAVE CROSSING THE MIDWEST WILL KEEP SKIES MOSTLY CLOUDY OVERNIGHT.
MADE NO CHANGES TO THE PRECIPITATION FORECAST WITH A CHANCE OF
SNOW FLURRIES/SNOW SHOWERS ACROSS NE OH/NW PA WITH THE FLOW OFF
LAKE ERIE AND ARCTIC AIR ARRIVING.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
COLD HIGH PRESSURE WILL BEGIN TO BUILD OVER THE REGION FROM THE
NORTHEAST ON SUNDAY. MODEL SOUNDINGS SHOW LOW LEVEL MOISTURE
TRAPPED BELOW AN INVERSION SO BROKEN CIGS ARE EXPECTED AT MINIMUM.
THE THREAT FOR LAKE EFFECT SHOWERS SHOULD PERSIST INTO EARLY
AFTERNOON ACROSS NW PA AND THEN DIMINISH AS THE DRY AIR FINALLY
WINS OUT. THE HIGH OVER THE NORTHERN PLAINS WILL MAKE IT`S WAY TO
THE LOCAL AREA SUNDAY NIGHT AND THIS SHOULD FINALLY CAUSE SKIES TO
CLEAR. MONDAY WILL BE COLD BUT DRY. HIGHS BOTH SUNDAY AND MONDAY
WILL BE 20 DEGREES BELOW NORMAL. MODELS COMING INTO BETTER
AGREEMENT WITH THE UPPER LEVEL SYSTEM SET TO DIVE SOUTHEAST ACROSS
THE AREA ON MONDAY NIGHT. TOUGH TO TELL HOW MUCH INFLUENCE THE
SYSTEM MOVING UP THE EAST COAST WILL HAVE ON THE LOCAL AREA. SOME
OF THE 12Z GUIDANCE NOW SHOWING A REFLECTION OF THE LOW AT THE
SURFACE. HAVE BUMPED PRECIP CHANCES UP TO LIKELY ALL AREAS ON
TUESDAY. IT`S LOOKING AN INCH OR TWO OF SNOW ACCUMULATION IS GOING
TO OCCUR FROM LATE MONDAY INTO TUESDAY EVENING. HAVE SLOWED THE
ONSET DOWN JUST A TAD FROM OUR PREVIOUS PACKAGE. THE SNOW SHOULD
END QUICKLY LATE TUESDAY AS THE WAVE ALOFT SCOOTS OFF TO THE EAST
COAST. HAVE TRENDED TO THE WARM SIDE OF GUIDANCE THE ENTIRE
PERIOD. THE NAM MOS JUST SEEMS TOO COOL MOST OF THE TIME.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
HIGH PRESSURE WILL BE BUILDING IN FROM THE WEST AS THE SYSTEM ON THE
EAST COAST CONTINUES INTO EASTERN CANADA. THE RESIDUAL COLD AIR THAT
WAS DRAWN SOUTHWARD WILL REMAIN AND WILL HAVE ANOTHER WELL BELOW
NORMAL DAY. THERE MAY BE A FEW LINGERING SNOW SHOWERS ACROSS THE FAR
EAST DURING THE FIRST PART OF WEDNESDAY. A WARM FRONT PUSHES
NORTHWARD THURSDAY MORNING AND AT THIS POINT A GOOD SOUTHERLY MOIST
FLOW WILL RESULT AND WILL FINALLY SEE TEMPERATURES REACH NORMAL.
OVERALL THERE IS GOOD AGREEMENT WITH A LOW MOVING OUT OF THE CENTRAL
PLAINS TO THE CENTRAL LAKES FOR THE WEEKEND. TIMING OF INITIAL
SHOWERS AHEAD OF THE FRONT QUESTIONABLE...BUT THE PRIMARY FOCUS WILL
BE FOR FRIDAY. THE COOL AIR BEHIND THIS FRONT IS MINIMAL AND ALREADY
UPSTREAM THE RIDGE IS SET TO BUILD OUR WAY.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
ARCTIC FRONT WILL SOUTH OF THE AREA WITH MUCH COLDER AIR MOVING
OVER THE LAKE. THE 850MB TEMPS FORECAST TO DIP TO -14C BY
DAYBREAK. AIRMASS IS VERY DRY SO DO NOT EXPECT MUCH MORE THAN A
FEW FLURRIES OVERNIGHT...BUT ENOUGH MOISTURE FOR SOME LAKE EFFECT
CLOUDS THIS MORNING. EXPECT WIDESPREAD STRATOCU DECK OF 2K-4K FT
THIS MORNING.
.OUTLOOK...MOSTLY VFR THIS AFTERNOON THROUGH LATE MONDAY THEN
NON VFR LIKELY ON TUESDAY WITH THE NEXT LOW PRESSURE SYSTEM.
&&
.MARINE...
WILL MAINTAIN A NORTHWEST FLOW ON THE LAKE THROUGH SUNDAY. HIGH
PRESSURE OVERHEAD FOR MONDAY. WIND DIRECTION AND SPEED TO SOME
DEGREE STILL UNCERTAIN FOR TUESDAY AS A DISTURBANCE CROSSES THE
SOUTHERN LAKES AND OHIO VALLEY...JOINING FORCES ON THE EAST COAST
FOR WEDNESDAY. SO THERE WILL BE PERIOD OF SOUTHERLY FLOW FOLLOWED BY
NORTHWEST FLOW BY TUESDAY NIGHT/WEDNESDAY. WILL MAINTAIN A 10-20
KNOT FORECAST. HIGH PRESSURE WEDNESDAY NIGHT/THURSDAY WITH A WARM
FRONTAL PASSAGE AND SOUTHERLY FLOW THURSDAY. FOR ICE
PURPOSES...TEMPERATURES WILL REMAIN NEAR OR BELOW FREEZING THROUGH
WEDNESDAY. THURSDAY TEMPERATURES WILL START TO WARM.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...KOSARIK
SHORT TERM...KUBINA
LONG TERM...OUDEMAN
AVIATION...DJB
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
928 AM EDT SUN MAR 23 2014
.SYNOPSIS...
AN AREA OF QUICK MOVING LOW PRESSURE WILL CROSS THE REGION
TODAY...AND HIGH PRESSURE WILL BUILD IN BEHIND IT TONIGHT AND
MONDAY. BY TUESDAY...LOOK FOR INCREASING CHANCES OF RAIN OR SNOW AS
A TROUGH OF LOW PRESSURE CROSSES THE APPALACHIANS. AS THE SYSTEM EXITS
THE REGION TUESDAY NIGHT...WINDS WILL BECOME GUSTY FROM THE
NORTHWEST. A MUCH WARMER PATTERN IS EXPECTED BY THE WEEKEND WITH
A CHANCE OF SHOWERS AND A FEW THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 915 AM EDT SUNDAY...
MID/UPPER LEVEL IMPULSE NOW PUSHING OUT OF TN COMBINED WITH
SFC TROUGH OVER NW NC LEADING TO NARROW AREA OF PRECIP FROM THE
SOUTHERN SHENANDOAH VALLEY TO THE NC MTNS/FOOTHILLS. THE 09Z HRRR
AND TO SOME EXTENT THE 06Z WRF/09Z RAP SHOW THIS FAIRLY WELL. THE
QUESTION IS QPF...AND MADE SOME ADJUSTMENTS TO POPS TO FOLLOW
THESE MODELS THROUGH THE AFTERNOON WHICH FAVORS HIGHER POPS ALONG
AND EAST OF THE BLUE RIDGE WITH LOW TO NO POPS IN THE NW. SNOW HAS
BEEN REPORTED AND OBSERVED AT THE HIGHER ELEVATIONS OVER NW NC AS
WELL AS AT BLF/JFZ. MADE ADJUSTMENTS BASED ON 12Z RNK SOUNDING
WHICH SHOWS WET BULB JUST ABOVE ZERO AT THE SFC BUT VERY DRY AIR
IN PLACE BELOW 800 MB. AS PRECIP MOVES IN THINK TEMPS WILL DROP A
FEW DEGREES AT THE SFC AND ALOFT...SO MOST LOCATIONS ABOVE 3000 FT
SHOULD SEE A LITTLE BIT OF SNOW WHILE MIX OR ALL RAIN ELSEWHERE.
OVERALL QPF AMOUNTS ARE LOW AND WITH WARM GROUND...ONLY A SLUSHY
INCH OR LESS IN THE HIGHER ELEVATIONS EXPECTED.
WILL SEE PRECIP AND SYSTEM EXIT AFTER 4-5 PM. SOME CLEARING TAKES
PLACE BEHIND THIS SYSTEM LATER THIS AFTERNOON SO TEMPS MAY BE ABLE
TO SURGE INTO THE UPPER 40S TO LOWER 50S ACROSS THE FOOTHILLS.
OVERALL...DID NOT MAKE TOO MANY ADJUSTMENTS TO TEMPS...EXCEPT COOL
IT OFF WHERE THE RAIN/SNOW IS.
PREVIOUS VALID DISCUSSION...
NORTHWEST WINDS WILL INCREASE ON THE BACKSIDE OF THE EXITING
SYSTEM WITH GUSTS OF 20 TO 25 MPH AT THE HIGHER ELEVATIONS.
HIGH PRESSURE WILL CONTINUE NOSING SOUTHEAST INTO OUR REGION AND
ALLOW FOR CLEAR SKIES....DECREASING WINDS...AND COLDER
CONDITIONS OVERNIGHT. LOWS TONIGHT WILL RANGE FROM THE UPPER
TEENS TO LOWER 20S ACROSS THE MOUNTAINS WITH LOW TO MID 20S ACROSS
THE PIEDMONT.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 430 AM EDT SUNDAY...
ALL MODELS NOW IN GOOD AGREEMENT THAT PHASING OF NORTHERN STREAM
UPPER TROUGH WITH SOUTHEAST U.S. COASTAL LOW WILL NOT TAKE PLACE
UNTIL THE LOW IS WELL OFFSHORE THE NC COAST. SUBSEQUENT TO
THIS...EXPLOSIVE CYCLOGENESIS IS EXPECTED WITH THE COASTAL LOW IN
RESPONSE TO NORTHERN STREAM UPPER SHORT WAVE DEEPENING AND TAKING
ON A NEGATIVE TILT AS IT MOVES TOWARD THE COAST. THUS...THE
EFFECTS OF THE COASTAL LOW ON OUR CWA IN TERMS OF PCPN WILL BE MINIMAL
AT BEST. THE MAJORITY OF THE PCPN OUR REGION SEES WILL BE THE
RESULT OF THE NORTHERN STREAM SHORT WAVE AS IT MOVES TOWARD THE
COAST EARLY TUE...PRIMARILY IN THE 06Z TO 18Z TIME FRAME ON TUE.
SUBSEQUENTLY...PCPN WILL DIMINISH/END ACROSS THE PIEDMONT AND
SWITCH OVER TO UPSLOPE...WHICH SHOULD BE FAIRLY EFFECTIVE GIVEN
INCREASINGLY STRONG NW TRAJECTORIES ORTHOGONAL TO THE ALLEGHANYS
AS THE COASTAL LOW DEEPENS.
SNOW AMOUNTS AND ACCUMULATIONS ARE QUITE QUESTIONABLE FOR THE
MAJORITY OF THE CWA OUTSIDE THE UPSLOPE ALONG THE ALLEGHANYS.
FIRST...MODELS HAVE TRENDED WARMER FOR MON NIGHT/EARLY TUE...SO
THERE IS NOW MORE OF A RAIN/SNOW MIX...ESPECIALLY ACROSS THE
PIEDMONT. SECOND...THE GROUND MAY BE TOO WARM FOR MUCH IF ANY
ACCUMULATION...ESPECIALLY AT LOWER ELEVATIONS. THIRD...QPF IS
GENERALLY 0.10 TO 0.20 AT BEST...MOST OF WHICH IS WEST OF THE
BLUE RIDGE. CONSIDERABLE ADJUSTMENT OF THE SNOW ACCUMULATION GRIDS
WAS NECESSARY TO LIMIT AMOUNTS...AND EVEN SO THEY MAY BE TOO HIGH
FOR LOCATIONS EAST OF THE ALLEGHANY FRONT. HOWEVER...MELTING IS
NOT TAKEN INTO ACCOUNT IN THESE FIGURES. UPSLOPE SNOW SHOULD YIELD
2 INCHES MOST AREAS FROM GREENBRIER TO WATAUGA...WITH POTENTIALLY
UP TO 4 INCHES IN WESTERN GREENBRIER/NW SUMMERS. TOO EARLY TO
ISSUE ANY ADVISORIES...BUT CAN SEE SUCH BEING ISSUED THIS TIME
TOMORROW NIGHT FOR THESE AREAS. FOR NOW...WILL JUST HIGHLIGHT IN
THE HWO. WIND WILL CLEARLY BE AN ISSUE AS WELL AS THE COASTAL LOW
DEEPENS...BUT CURRENT THINKING IS THAT IT MAY BE FAR ENOUGH
OFFSHORE TO PRECLUDE THE ISSUANCE OF WIND ADVISORIES.
850MB TEMPS BOTTOM OUT AROUND -10C EARLY MON...REBOUND INTO THE
MINUS SINGLE DIGIT RANGE BY MON AFTERNOON...THEN DROP BACK TO
AROUND -14C BY 12Z WED BEFORE QUICKLY RETURN BACK ABOVE ZERO C BY
THE END OF THE WEEK. IN FACT...EXTENDED RANGE MODELS CONTINUE TO
ADVERTISE WHAT IN GENERAL MAY FINALLY BE THE END OF WINTER...WITH
VERY FEW INTRUSIONS OF 850MB TEMPS BELOW 0C AFT THU...WITH
POTENTIALLY +12C BY THE WEEKEND.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 445 AM EDT SUNDAY...
AS NOTED ABOVE...ALL MODELS CONTINUE TO POINT WHAT MAY BE THE
OVERALL END OF WHAT HAS BEEN A LONG...COLD WINTER. THE UPPER FLOW
RAPIDLY BECOMES ZONAL...THEN SOUTHWEST DURING THE LATER HALF OF
THE WEEK. OUR ATTENTION WILL THEN TURN TO A FAST MOVING SOUTHERN
STREAM SHORT WAVE PROGGED TO TRACK FROM THE SOUTHERN PLAINS THU TO
THE OH VALLEY BY FRI. MOST OF THE PCPN WITH THIS SYSTEM WILL
REMAIN NW OF THE CWA. IN ITS WAKE...SOUTHWEST FLOW REMAINS IN
PLACE AND A WEAKNESS IN THE UPPER FLOW ACROSS THE SOUTHERN PLAINS
INTO THE SOUTHEAST WILL LINGER AND SUBSEQUENTLY MAY DEVELOP INTO A
CUTOFF LOW ACROSS THE SOUTHEAST STATES TOWARD EARLY NEXT WEEK.
HOWEVER...THE MODELS HAVE CONSIDERABLY DIFFICULTY RESOLVING THIS
FEATURE WITH TIME. AT ANY RATE...IT APPEARS WE WILL RAPIDLY EVOLVE
FROM WINTER CONDITIONS AT MID-WEEK TO A PROLONGED PERIOD OF
CLOUDS...RAIN CHANCES...AND MILD TO ABOVE NORMAL TEMPERATURES THAT
WILL LIKELY LAST THROUGH AT LEAST EARLY NEXT WEEK. MUCH OF THE CWA
MAY FAIL TO FALL BELOW FREEZING AFTER THU MORNING UNTIL PERHAPS
NEXT WEEK.
GIVEN THE WARM TEMPERATURES AND INCREASING INSTABILITY
NOTED...ESPECIALLY ACROSS OUR SOUTHERN ZONES NEXT SAT...IN
CONJUNCTION WITH A FAIRLY COMMON SPRINGTIME PATTERN...HAVE
INTRODUCED TSRA FOR SAT AFTERNOON ACROSS FAR SW VA AND NW NC.
&&
.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
AS OF 745 AM EDT SUNDAY...
FAST MOVING DISTURBANCE WILL BRING A PERIOD OF LIGHT RAIN AND LOW
END VFR OR HIGH END MVFR CIGS THROUGH THE AFTERNOON. MOST OF THE
RAIN WILL TRACK SOUTH OF U.S. 460. UPSLOPE NW FLOW ON THE BACK
SIDE OF THE DISTURBANCE/FRONT WILL KEEP HIGH END MVFR CIGS IN
PLACE ACROSS EASTERN WV THROUGH LATE AFTERNOON. BY 00Z...ALL SITES
SHOULD SEE SKC OR AT BEST SCT025-035. BRIEF MVFR VSBYS POSSIBLE IN
AREAS OF -RA...BUT MOSTLY VFR EXPECTED. WINDS NW WEST OF THE BLUE
RIDGE...NE EAST OF THE BLUE RIDGE. SPEEDS 5-10KTS...WITH LOW END
GUSTS POSSIBLE BEHIND FRONTAL PASSAGE DURING THE
AFTERNOON...MAINLY ACROSS THE PIEDMONT. WINDS WILL DIMINISH TO
7KTS OR LESS AFT 00Z.
MEDIUM TO HIGH CONFIDENCE IN CIGS/VSBYS THROUGH THE TAF VALID
PERIOD.
MEDIUM TO HIGH CONFIDENCE IN WIND SPD/DIR THROUGH THE TAF VALID
PERIOD.
EXTENDED AVIATION DISCUSSION...
A DEEPENING COASTAL LOW AND ASSOCIATED UPPER-LEVEL DISTURBANCE
COULD BRING WINTRY WEATHER TUESDAY WITH SUB VFR CONDITIONS FOR ALL
AREAS. SNOWFALL SHOULD BE PRIMARILY CONFINED TO UPSLOPE AREAS
AFTER AN INITIAL PERIOD OF -SN TUESDAY MORNING. SNOWFALL AMOUNTS
ARE EXPECTED TO BE LIGHT...BUT MVFR VSBYS/CIGS MAY BE POSSIBLE FOR
A PERIOD. OF BIGGER CONCERN WILL BE STRONG...GUSTY NW WINDS
DEVELOPING TUE AFTERNOON AND EVENING. VFR CIGS SHOULD RETURN BY
WED AS HIGH PRESSURE BUILDS ACROSS THE REGION WITH SW FLOW
INCREASING BY THURSDAY AS HIGH PRESSURE MOVES OFF THE NC COAST AND
THE NEXT STORM SYSTEM SLIDES ACROSS THE LOWER MISSOURI VALLEY.
EXPECT VFR WED AFTN-THU.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS
NEAR TERM...DS/WP
SHORT TERM...RAB
LONG TERM...KM/RAB
AVIATION...DS/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
130 AM EDT SUN MAR 23 2014
.SYNOPSIS...
A COLD FRONT SLIDES EAST OF THE AREA OVERNIGHT. A LOW PRESSURE
SYSTEM WILL PASS SOUTH OF THE AREA ON SUNDAY...DEPARTING DURING
SUNDAY EVENING. LARGE HIGH PRESSURE WILL BE ENTRENCHED MONDAY OVER
THE OHIO VALLEY AND MIDDLE ATLANTIC...BEFORE LOW PRESSURE MOVES
ALONG THE SOUTHEAST COAST TUESDAY...THEN NEAR THE NEW ENGLAND
COAST WEDNESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1230 AM EDT SUNDAY...
ONLY SOME MINOR ADJUSTMENTS TO THE FORECAST THROUGH THE REMAINDER
OF THE OVERNIGHT HOURS. LATEST 00Z/8PM WRF-ARW AND HRRR GUIDANCE
IS SHOWING A SLIGHTLY SLOWER ARRIVAL TIME OF THE PRECIPITATION
TOWARDS DAYBREAK SUNDAY. AN 11-12Z/7AM-8AM ARRIVAL IN THE FAR WEST
IS LOOKING MORE PROBABLE ACCORDING TO THIS GUIDANCE. DID NOT WANT
DISREGARD THE PREVIOUS FORECAST AND SELECTED A MIDPOINT BETWEEN
THE OLD AND NEW WITH A 09-10Z/5AM-6AM ARRIVAL IN THE FAR WESTERN
PARTS OF THE AREA OF MAINLY LIGHT RAIN WITH A FEW SPOTS OF LIGHT
SNOW AT HIGHER ELEVATIONS. HAVE ALSO TWEAKED HOURLY TEMPERATURE
AND DEW POINT TRENDS THE NEXT FEW HOURS BASED UPON THE LATEST
OBSERVATIONS AND ANTICIPATED TRENDS.
AS OF 825 PM EDT SATURDAY...
WEAK COLD FRONT ALONG THE EASTERN SLOPES OF THE BLUE RIDGE THIS
EVENING REMAINS SLOW TO MOVE EAST BUT SHOULD PASS THROUGH THE
PIEDMONT IN THE NEXT COUPLE OF HOURS. OTRW BRIEF CLEARING IN THE
WAKE OF THE FRONT EARLY TONIGHT WILL GRADUALLY BE REPLACED BY
INCREASING MID AND HIGH CLOUDS AFTER MIDNIGHT AHEAD OF THE NEXT
WAVE TO THE SW. LATEST GUIDANCE A BIT FASTER PER JET ALOFT IN
PUSHING CLOUDS BACK IN OVERNIGHT ALONG WITH A SLIGHTLY QUICKER
ONSET OF PRECIP EARLY SUNDAY DESPITE INITIAL DRY AIR OFF EVENING
RAOBS. THEREFORE HAVE TRENDED WITH MORE CLOUDS LATE AND ARRIVAL
OF PRECIP OVER THE WEST JUST BEFORE DAYBREAK AND ALONG THE BLUE
RIDGE BY MID MORNING IF NOT SOONER. HOWEVER COLD ADVECTION LAGGING
THE FRONT A BIT AND LIKELY WONT SEE MUCH OF THE COLDER AIR WORK
INTO THE SE UNTIL SUNDAY. THIS PUTS OVERNIGHT LOWS CLOSER TO THE
EARLIER WARMER MAV MOS SO ADJUSTED CLOSER TO THOSE VALUES ESPCLY
SOUTH AND EAST.
PREVIOUS DISCUSSION AS OF 300 PM EDT SATURDAY...
COLD FRONT SITUATED FROM DC TO WRN NC WILL SLIDE SE OVERNIGHT.
SHOULD SEE SOME CLEARING THIS EVENING WITH MID/HIGH LVL MOISTURE
SHIFTING EAST AND SOUTH. NEXT FAST MOVING WAVE STREAMING STREAMING
EAST FROM THE SRN PLAINS WILL BE PASSING BY SUNDAY. MODELS SHOWING
MOST OF THE PRECIP STAYING ALONG AND SOUTH OF HIGHWAY 460 ACROSS THE
WEST AND LIFTING TOWARD LYH SUNDAY BEFORE NOON. LEANED TOWARD THE
12Z ECMWF/CMC. AT THIS TIME...APPEARS MOST PRECIP WILL BE RAIN WITH
SOME SNOW AT ELEVATIONS ABOVE 3000 FT. COLD AIR CHASES THE PRECIP SO
SNOW AMOUNTS WILL BE LIMITED TO THE HIGHER ELEVATIONS OF THE WEST
WITH NO MORE THAN A SLUSHY INCH EXPECTED.
AFTER WARM DAY TODAY WITH LOW HUMIDITY THE AIR SUNDAY WILL RETURN TO
MORE LIKE EARLY FEBRUARY WITH HIGHS RANGING FROM THE UPPER
30S...LOWER 40S WEST TO NEAR 50 EAST.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
AS OF 330 PM EDT SATURDAY...
MODELS CONSISTENTLY KEEPING TUESDAY`S SYSTEM FAR ENOUGH OFF THE
COAST...SUCH THAT THE ONLY IMPACT ON THE REGION IS FROM THE WEAKER
LOW PRESSURE ASSOC WITH THE UPPER LEVEL DISTURBANCE AS IT ARRIVES
TUESDAY THROUGH THE OHIO VALLEY. NOW...THE PRECIP ASSOC WITH THE
COASTAL SYSTEM IS EVEN BEING PUSHED SE OF THE VA/NC PIEDMONT.
TYPICALLY...OUR REGION DOESN`T DO AS WELL AS MODEL QPF SUGGESTS
WITH THE UPPER SYSTEM ASSOC WITH A COASTAL. IN ADDITION...IF ANY
OF THE QPF ARRIVES DURING THE DAY...NOT ONLY WILL RAIN MIX
IN...BUT ALSO SNOW MAY MELT WHEN IT MAKES CONTACT WITH THE GROUND.
ALSO...DON`T SEE SNOWFALL RATES BEING FAST ENOUGH TO OVERCOME
MARCH INSOLATION/WARM BOUNDARY LAYER. THUS...ANY SNOW MAY ONLY
ACCUMULATE ABOVE 2500 FEET. IF SOME PRECIP ARRIVES QUICKLY LATE
MONDAY NIGHT...THEN SNOW MAY ACCUMULATE MORE EFFICIENTLY...BUT
WE`RE ONLY TALKING ABOUT 0.10" LIQUID AT THE MOST IN THE WEST LATE
MONDAY NIGHT. MODELS CAN STILL CHANGE AND COME FURTHER
WEST...ALTHOUGH THIS DOESN`T SEEM LIKELY CONSIDERING CURRENT
CONSENSUS AND TRENDS. WE`LL SEE. THUS AT THIS POINT...PERHAPS AN
ADVISORY CRITERIA EVENT AT THE HIGHEST ELEVATIONS OF SE WEST
VA...EXTREME SW VA AND NW NC.
UPSLOPE SNOW SHOWERS WILL CONTINUE THROUGH SE WEST VA AND PERHAPS
INTO NW NC TUESDAY NIGHT...ALTHOUGH H7 MOISTURE SEEMS TO MOVE OUT
BY 6Z WED WHICH WOULD ONLY LEAVE A 6HR PERIOD FOR ANY UPSLOPE
EVENT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 330 PM EDT SATURDAY...
LOOKING LIKE WINTER`S LAST GASP...BUT AN IMPRESSIVE ONE AT THAT
WITH WEDNESDAY VERY COLD...AND THEN STRONG SURFACE HIGH ALMOST
DIRECTLY OVER THE CWA WED NIGHT...WITH MANY SPOTS DECOUPLING AND
FALLING POSSIBLY A FEW DEGREES BELOW THE COLDEST GUIDANCE FOR
MINS. UPPER TROUGH RAPIDLY LIFTS OUT AND TEMPS REBOUND QUICKLY AS
IS COMMONPLACE FOR LATE MARCH. RAIN SHOWERS LOOK TO DEVELOP OUT
AHEAD OF THE NEXT COLD FRONT PROGGED FOR SATURDAY. AIR BEHIND THIS
SYSTEM ISN`T IMPRESSIVE AT ALL.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 125 AM EDT SUNDAY...
VFR CONDITIONS PREVAIL ACROSS THE REGION. THIS IS EXPECTED TO BE
THE PATTERN THROUGH 12Z/7AM SUNDAY. AT THIS POINT...A QUICK MOVING
DISTURBANCE WILL RACE ACROSS THE AREA AN BRING A BRIEF PERIOD OF
MVFR CIGS TO MUCH OF THE AREA ALONG WITH SOME LIGHT RAIN/SNOW MIX
IN THE MOUNTAINS AND LIGHT RAIN TO AREAS EAST OF THE CREST OF THE
BLUE RIGE. BY 19Z/3PM...MOST OF THE PRECIPITATION WILL HAVE ENDED
AND CIGS WILL HAVE IMPROVED TO LOW END VFR...AND WINDS WILL START
TO GUST AROUND 15 TO 20 KTS ACROSS THE MOUNTAINS. BY SUNDAY
EVENING...GUSTS WILL CONTINUE ACROSS THE MOUNTAINS UNTIL ABOUT
MIDNIGHT WITH SCATTERED UPSLOPE VFR CLOUDS WITH BASES AROUND 5000
FT MSL.
AS OF 640 PM EDT SATURDAY...
EXTENDED AVIATION DISCUSSION... EXPECT CLEARING SUNDAY EVENING
WITH HIGH PRESSURE ENTERING FROM THE NORTHWEST AND CONTINUED VFR
ON MONDAY UNDER HIGH PRESSURE.
ANOTHER LOW PRESSURE SYSTEM COULD BRING WINTRY WEATHER TUESDAY
WITH SUB VFR CONDITIONS FOR ALL AREAS. MODELS ARE TRENDING TOWARDS
A STORM TRACK INCREASINGLY OFF THE COAST...SO CONFIDENCE IN
DURATION AND AMOUNT OF SNOWFALL NOT VERY HIGH AT THIS POINT. GUSTY
WINDS WILL ARRIVE TUESDAY NIGHT WITH POSSIBLE IFR MOUNTAIN SNOW
SHOWERS AT LWB/BLF. MODELS BRING HIGH PRESSURE IN BY WED AFTERNOON
WITH SW FLOW INCREASING BY THURSDAY AS HIGH PRESSURE MOVES OFF THE
NC COAST AND THE NEXT STORM SYSTEM SLIDES ACROSS THE LOWER
MISSOURI VALLEY. EXPECT VFR WED AFTN-THU.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...NF/WP
NEAR TERM...DS/JH/WP
SHORT TERM...KM
LONG TERM...KM
AVIATION...DS/JH/NF/RAB/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1239 AM EDT SUN MAR 23 2014
.SYNOPSIS...
A COLD FRONT SLIDES EAST OF THE AREA OVERNIGHT. A LOW PRESSURE
SYSTEM WILL PASS SOUTH OF THE AREA ON SUNDAY...DEPARTING DURING
SUNDAY EVENING. LARGE HIGH PRESSURE WILL BE ENTRENCHED MONDAY OVER
THE OHIO VALLEY AND MIDDLE ATLANTIC...BEFORE LOW PRESSURE MOVES
ALONG THE SOUTHEAST COAST TUESDAY...THEN NEAR THE NEW ENGLAND
COAST WEDNESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1230 AM EDT SUNDAY...
ONLY SOME MINOR ADJUSTMENTS TO THE FORECAST THROUGH THE REMAINDER
OF THE OVERNIGHT HOURS. LATEST 00Z/8PM WRF-ARW AND HRRR GUIDANCE
IS SHOWING A SLIGHTLY SLOWER ARRIVAL TIME OF THE PRECIPITATION
TOWARDS DAYBREAK SUNDAY. AN 11-12Z/7AM-8AM ARRIVAL IN THE FAR WEST
IS LOOKING MORE PROBABLE ACCORDING TO THIS GUIDANCE. DID NOT WANT
DISREGARD THE PREVIOUS FORECAST AND SELECTED A MIDPOINT BETWEEN
THE OLD AND NEW WITH A 09-10Z/5AM-6AM ARRIVAL IN THE FAR WESTERN
PARTS OF THE AREA OF MAINLY LIGHT RAIN WITH A FEW SPOTS OF LIGHT
SNOW AT HIGHER ELEVATIONS. HAVE ALSO TWEAKED HOURLY TEMPERATURE
AND DEW POINT TRENDS THE NEXT FEW HOURS BASED UPON THE LATEST
OBSERVATIONS AND ANTICIPATED TRENDS.
AS OF 825 PM EDT SATURDAY...
WEAK COLD FRONT ALONG THE EASTERN SLOPES OF THE BLUE RIDGE THIS
EVENING REMAINS SLOW TO MOVE EAST BUT SHOULD PASS THROUGH THE
PIEDMONT IN THE NEXT COUPLE OF HOURS. OTRW BRIEF CLEARING IN THE
WAKE OF THE FRONT EARLY TONIGHT WILL GRADUALLY BE REPLACED BY
INCREASING MID AND HIGH CLOUDS AFTER MIDNIGHT AHEAD OF THE NEXT
WAVE TO THE SW. LATEST GUIDANCE A BIT FASTER PER JET ALOFT IN
PUSHING CLOUDS BACK IN OVERNIGHT ALONG WITH A SLIGHTLY QUICKER
ONSET OF PRECIP EARLY SUNDAY DESPITE INITIAL DRY AIR OFF EVENING
RAOBS. THEREFORE HAVE TRENDED WITH MORE CLOUDS LATE AND ARRIVAL
OF PRECIP OVER THE WEST JUST BEFORE DAYBREAK AND ALONG THE BLUE
RIDGE BY MID MORNING IF NOT SOONER. HOWEVER COLD ADVECTION LAGGING
THE FRONT A BIT AND LIKELY WONT SEE MUCH OF THE COLDER AIR WORK
INTO THE SE UNTIL SUNDAY. THIS PUTS OVERNIGHT LOWS CLOSER TO THE
EARLIER WARMER MAV MOS SO ADJUSTED CLOSER TO THOSE VALUES ESPCLY
SOUTH AND EAST.
PREVIOUS DISCUSSION AS OF 300 PM EDT SATURDAY...
COLD FRONT SITUATED FROM DC TO WRN NC WILL SLIDE SE OVERNIGHT.
SHOULD SEE SOME CLEARING THIS EVENING WITH MID/HIGH LVL MOISTURE
SHIFTING EAST AND SOUTH. NEXT FAST MOVING WAVE STREAMING STREAMING
EAST FROM THE SRN PLAINS WILL BE PASSING BY SUNDAY. MODELS SHOWING
MOST OF THE PRECIP STAYING ALONG AND SOUTH OF HIGHWAY 460 ACROSS THE
WEST AND LIFTING TOWARD LYH SUNDAY BEFORE NOON. LEANED TOWARD THE
12Z ECMWF/CMC. AT THIS TIME...APPEARS MOST PRECIP WILL BE RAIN WITH
SOME SNOW AT ELEVATIONS ABOVE 3000 FT. COLD AIR CHASES THE PRECIP SO
SNOW AMOUNTS WILL BE LIMITED TO THE HIGHER ELEVATIONS OF THE WEST
WITH NO MORE THAN A SLUSHY INCH EXPECTED.
AFTER WARM DAY TODAY WITH LOW HUMIDITY THE AIR SUNDAY WILL RETURN TO
MORE LIKE EARLY FEBRUARY WITH HIGHS RANGING FROM THE UPPER
30S...LOWER 40S WEST TO NEAR 50 EAST.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
AS OF 330 PM EDT SATURDAY...
MODELS CONSISTENTLY KEEPING TUESDAY`S SYSTEM FAR ENOUGH OFF THE
COAST...SUCH THAT THE ONLY IMPACT ON THE REGION IS FROM THE WEAKER
LOW PRESSURE ASSOC WITH THE UPPER LEVEL DISTURBANCE AS IT ARRIVES
TUESDAY THROUGH THE OHIO VALLEY. NOW...THE PRECIP ASSOC WITH THE
COASTAL SYSTEM IS EVEN BEING PUSHED SE OF THE VA/NC PIEDMONT.
TYPICALLY...OUR REGION DOESN`T DO AS WELL AS MODEL QPF SUGGESTS
WITH THE UPPER SYSTEM ASSOC WITH A COASTAL. IN ADDITION...IF ANY
OF THE QPF ARRIVES DURING THE DAY...NOT ONLY WILL RAIN MIX
IN...BUT ALSO SNOW MAY MELT WHEN IT MAKES CONTACT WITH THE GROUND.
ALSO...DON`T SEE SNOWFALL RATES BEING FAST ENOUGH TO OVERCOME
MARCH INSOLATION/WARM BOUNDARY LAYER. THUS...ANY SNOW MAY ONLY
ACCUMULATE ABOVE 2500 FEET. IF SOME PRECIP ARRIVES QUICKLY LATE
MONDAY NIGHT...THEN SNOW MAY ACCUMULATE MORE EFFICIENTLY...BUT
WE`RE ONLY TALKING ABOUT 0.10" LIQUID AT THE MOST IN THE WEST LATE
MONDAY NIGHT. MODELS CAN STILL CHANGE AND COME FURTHER
WEST...ALTHOUGH THIS DOESN`T SEEM LIKELY CONSIDERING CURRENT
CONSENSUS AND TRENDS. WE`LL SEE. THUS AT THIS POINT...PERHAPS AN
ADVISORY CRITERIA EVENT AT THE HIGHEST ELEVATIONS OF SE WEST
VA...EXTREME SW VA AND NW NC.
UPSLOPE SNOW SHOWERS WILL CONTINUE THROUGH SE WEST VA AND PERHAPS
INTO NW NC TUESDAY NIGHT...ALTHOUGH H7 MOISTURE SEEMS TO MOVE OUT
BY 6Z WED WHICH WOULD ONLY LEAVE A 6HR PERIOD FOR ANY UPSLOPE
EVENT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 330 PM EDT SATURDAY...
LOOKING LIKE WINTER`S LAST GASP...BUT AN IMPRESSIVE ONE AT THAT
WITH WEDNESDAY VERY COLD...AND THEN STRONG SURFACE HIGH ALMOST
DIRECTLY OVER THE CWA WED NIGHT...WITH MANY SPOTS DECOUPLING AND
FALLING POSSIBLY A FEW DEGREES BELOW THE COLDEST GUIDANCE FOR
MINS. UPPER TROUGH RAPIDLY LIFTS OUT AND TEMPS REBOUND QUICKLY AS
IS COMMONPLACE FOR LATE MARCH. RAIN SHOWERS LOOK TO DEVELOP OUT
AHEAD OF THE NEXT COLD FRONT PROGGED FOR SATURDAY. AIR BEHIND THIS
SYSTEM ISN`T IMPRESSIVE AT ALL.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 640 PM EDT SATURDAY...
SKIES CLEARING ACROSS THE REGION THIS EVENING WILL ENSURE VFR
CONDITIONS INTO THE OVERNIGHT AS A COLD FRONT MOVES EAST AND WINDS
SUBSIDE. HIGH AND MID CLOUDS SHOULD MAKE A RETURN AFTER MIDNIGHT
WITH CEILINGS LOWERING BY DAYBREAK FROM SW TO NE AS ANOTHER WAVE
MOVES UP ALONG THE RESIDUAL FRONT TO THE SOUTH.
THIS WAVE WORKS ACROSS THE AREA SUNDAY MORNING AND WILL BE ENOUGH
LIFT TO WARRANT LIGHT RAIN/SPRINKLES AT ALL SITES MIXED WITH SNOW
AT BLF/LWB. VSBYS SHOULD STAY VFR ALTHOUGH THINK BCB/DAN/BLF COULD
GET ENOUGH MOISTURE TO LOWER VSBYS TO MVFR WITH PERHAPS BRIEF IFR
AT BLF IF PRECIP ENDS UP BEING MORE SNOW THAN RAIN EARLY SUNDAY.
CEILINGS LOOK TO DROP INTO HIGH END MVFR LEVELS MOST SITES OUTSIDE
OF LWB AND POSSIBLY LYH WHERE PREDOMINANT VFR CLOUD BASES SHOULD
PREVAIL.
EXTENDED AVIATION DISCUSSION... EXPECT CLEARING SUNDAY EVENING
WITH HIGH PRESSURE ENTERING FROM THE NORTHWEST AND CONTINUED VFR
ON MONDAY UNDER HIGH PRESSURE.
ANOTHER LOW PRESSURE SYSTEM COULD BRING WINTRY WEATHER TUESDAY
WITH SUB VFR CONDITIONS FOR ALL AREAS. MODELS ARE TRENDING TOWARDS
A STORM TRACK INCREASINGLY OFF THE COAST...SO CONFIDENCE IN
DURATION AND AMOUNT OF SNOWFALL NOT VERY HIGH AT THIS POINT. GUSTY
WINDS WILL ARRIVE TUESDAY NIGHT WITH POSSIBLE IFR MOUNTAIN SNOW
SHOWERS AT LWB/BLF. MODELS BRING HIGH PRESSURE IN BY WED AFTERNOON
WITH SW FLOW INCREASING BY THURSDAY AS HIGH PRESSURE MOVES OFF THE
NC COAST AND THE NEXT STORM SYSTEM SLIDES ACROSS THE LOWER
MISSOURI VALLEY. EXPECT VFR WED AFTN-THU.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...NF/WP
NEAR TERM...DS/JH/WP
SHORT TERM...KM
LONG TERM...KM
AVIATION...JH/NF/RAB/WP
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
841 PM CDT MON MAR 24 2014
.UPDATE...THE EXPECTED BAND OF SNOWFALL ASSOCIATED WITH A PASSING
COLD FRONT HAS BEGUN PUSHING THROUGH THE FORECAST AREA. BASED ON
UPSTREAM OBS AND REPORTS...VISIBILITIES WILL TO DROP TO AS LOW AS
1/4 MILE WITH THIS BAND. ACCUMULATIONS WILL LIKELY BE AROUND 1/2
INCH...THOUGH LOCALLY UP TO AN INCH IS POSSIBLE. MOST OF THE
ACCUMULATION WILL FALL IN AROUND A 30 TO 45 MINUTE PERIOD. THIS
BAND WILL HIT THE MADISON AREA BETWEEN 9 AND 10 PM...AND THE
MILWAUKEE AREA BETWEEN 11 PM AND MIDNIGHT. ROADS WILL LIKELY
BECOME SNOW COVERED AND SLIPPERY.
SCATTERED SNOW SHOWERS WILL THEN PROBABLY LINGER THROUGH MUCH OF
THE NIGHT. THESE SHOWERS WILL BE HIT AND MISS...WITH LITTLE TO NO
ADDITIONAL ACCUMULATION EXPECTED.
&&
.AVIATION/06Z TAFS/...
THE BAND OF SNOWFALL ASSOCIATED WITH A PASSING COLD FRONT HAS
BEGUN PUSHING THROUGH THE FORECAST AREA. BASED ON UPSTREAM OBS AND
REPORTS...EXPECT VISIBILITIES TO DROP TO AS LOW AS 1/4 MILE WITH
THIS BAND. ACCUMULATIONS WILL LIKELY BE AROUND 1/2 INCH...THOUGH
LOCALLY UP TO AN INCH IS POSSIBLE. MOST OF THE ACCUMULATION WILL
FALL IN AROUND A 30 TO 45 MINUTE PERIOD.
SCATTERED SNOW SHOWERS WILL THEN PROBABLY LINGER THROUGH MUCH OF
THE NIGHT AND POSSIBLY INTO EARLY TUESDAY MORNING. THESE SHOWERS
WILL BE HIT AND MISS...WITH LITTLE TO NO ADDITIONAL ACCUMULATION
EXPECTED.
MAINLY VFR CONDITIONS ARE EXPECTED BEHIND THE MAIN BAND OF
SNOW...THOUGH SOME MVFR CIGS/VSBYS BRIEFLY POSSIBLE IN SNOW
SHOWERS.
LOOKS LIKE BKN CIGS TOMORROW...WITH SOUNDINGS AND MOS RIGHT NEAR
THE MVFR/VFR BORDER. WILL KEEP AS LOWER END VFR FOR NOW.
&&
.PREV DISCUSSION... /ISSUED 335 PM CDT MON MAR 24 2014/
SHORT TERM...
TONIGHT...FORECAST CONFIDENCE MEDIUM
THERE IS WEAK LOW LEVEL ISENTROPIC LIFT AND WARM AIR ADVECTION
CURRENTLY OVER NORTHEAST IOWA AND WEST CENTRAL WI. THIS WEAK FORCING
IS RUNNING INTO VERY DRY LOW LEVEL AIR AS IT APPROACHES SOUTH
CENTRAL WI. THUS...EXPECTING LIGHT SNOW TO HOLD OFF OVER THE FAR
WESTERN FORECAST AREA THROUGH MOST OF THE AFTERNOON.
THE WRF-NMM AND RAP ARE A LITTLE MORE AGGRESSIVE WITH BRINGING IN
PRECIP THIS AFTERNOON...WHILE OTHER MODELS MAINTAIN A DRY FORECAST.
THE RAP EVEN SHOWS CONVECTIVE SNOW SHOWER POTENTIAL WITHIN THE WAA
AREA PER BUFKIT FORECAST SOUNDINGS. THE 17Z HRRR KEEPS MOST WAA
REFLECTIVITY SOUTH OF THE WI BORDER.
IT IS LOOKING MORE LIKELY THAT A BAND OF SNOW WILL DEVELOP JUST
AHEAD OF THE COLD FRONT. THIS IS ALREADY HAPPENING IN SOUTHEAST
MINNESOTA. THIS IS WHERE THERE IS DECENT OMEGA AND IT LANDS WITHIN
THE DENDRITE ZONE...ALONG WITH FRONTOGENESIS. I AM LESS CERTAIN
ABOUT HOW LONG THE SNOW WILL LAST. THE MODELS ARE PAINTING A LONGER-
DURATION QPF EVENT...BUT THE MORE LIKELY SCENARIO WOULD BE FOR A ONE
TO TWO HOUR MODERATE SNOWFALL JUST AHEAD OF THE FRONT...FOLLOWED BY
SEVERAL HOURS OF SCATTERED SNOW SHOWERS WITH THE STEEP LOW LEVEL
LAPSE RATES DUE TO STRONG COLD AIR ADVECTION BEHIND THE FRONT.
TUESDAY...FORECAST CONFIDENCE HIGH
NORTHWEST WINDS WILL INCREASE AND BECOME GUSTY BEHIND THE COLD FRONT
TONIGHT...ESPECIALLY AFTER MIDNIGHT. A TIGHT SURFACE PRESSURE
GRADIENT...STEEP LOW LEVEL LAPSE RATES AND CYCLONIC FLOW ALOFT WILL
ALLOW FOR STRONG NORTHWEST WINDS TO CONTINUE ALL DAY TUESDAY AS
WELL. FREQUENT GUSTS TO 25 MPH ARE LIKELY. PLAN ON OVERCAST TO
BROKEN CLOUDS FOR MOST OF THE DAY...ESPECIALLY IN SOUTHEAST
WISCONSIN. FLURRIES WILL BE POSSIBLE THROUGH THE MORNING DUE TO
ANOTHER WEAK UPPER LEVEL SHORTWAVE DROPPING THROUGH.
TEMPERATURES WILL HOLD FAIRLY STEADY THROUGH THE DAY IN THE LOWER
20S WITH THE CORE OF 925MB TEMPS OF AROUND -14C SITTING OVER CENTRAL
WI.
TUESDAY NIGHT THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM
A SFC RIDGE WILL SLOWLY MOVE EWD ACROSS THE REGION TUE NT. GOOD
RADIATIONAL COOLING AND COLD TEMPS ARE EXPECTED. CYCLOGENESIS OVER
THE THE CENTRAL PLAINS WILL LEAD TO SLY WINDS AND WARM ADVECTION
AS FAR EAST AS WI BEGINNING ON WED. SKIES WILL BECOME CLOUDY DUE
TO FAIRLY STRONG MID LEVEL WARM ADVECTION BUT LOW LEVELS APPEAR TO
BE TOO DRY FOR PCPN. TEMPS WILL WARM INTO THE 30S AND THEN HOLD
STEADY IN THE 30S WED NT.
A 50-60 KNOT LOW LEVEL JET WILL THEN SHIFT TOWARD THE REGION FOR
WED NT INTO THU NT. BEST LIFT COINCIDED WITH MOISTURE WILL BE FOR
THU AND THU NT AS LOW PRESSURE AREA AND ASSOCIATED SHORTWAVE
TROUGH MOVE ACROSS SRN WI. CHANCE POPS FOR RAIN/SNOW WED NT AND
THEN LIKELY RAIN FOR THU/THU NT WITH LINGERING POPS ON FRI FOR
RAIN/SNOW.
LONG TERM...
SATURDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM
HIGH PRESSURE TO PREVAIL ON SAT BUT WILL MOVE EWD BY SAT NT WITH
SWLY WINDS AND WARM ADVECTION AS AN UPPER RIDGE APPROACHES FROM
THE PLAINS. SWLY WINDS AND WARM ADVECTION TO CONTINUE INTO SUN
WITH 1000-500 MB THICKNESSES OF 552-558 DM. HIGH TEMPS LIKELY IN
THE 60S IF THIS PATTERN HOLDS. A DEVELOPING LOW OVER THE PLAINS
WILL THEN TRACK ACROSS WI ON MON WITH CONTINUED MILD TEMPS BUT
RAIN.
AVIATION/00Z TAFS/...
VFR CONDITIONS WILL CONTINUE THROUGH THE AFTERNOON ACROSS SOUTHERN
WI. THERE IS AN OUTSIDE CHANCE FOR LIGHT SNOW TO DEVELOP LATE THIS
AFTERNOON ACROSS SOUTH CENTRAL WI AND POSSIBLY NEAR FOND DU LAC AND
SHEBOYGAN...BUT OVERCOMING THE LOW LEVEL DRY AIR IN PLACE WILL MOST
LIKELY KEEP ANY PRECIP ALOFT FROM REACHING THE GROUND.
THE BETTER CHANCE FOR A BAND OF MODERATE SNOW WILL BE JUST AHEAD OF
A COLD FRONT THAT WILL MOVE SOUTHEAST ACROSS SOUTHERN WI THIS
EVENING. GUSTY NORTHWEST WINDS ARE EXPECTED ALONG AND BEHIND THIS
COLD FRONT...ALONG WITH SCATTERED LIGHT SNOW SHOWERS OR FLURRIES
THROUGH THE REST OF THE NIGHT AND THROUGH TUESDAY MORNING. MVFR
CIGS/VSBYS EXPECTED WITH THE SNOW...WITH AROUND A HALF INCH OF
ACCUMULATION. LOOK FOR STRONG AND GUSTY NORTHWEST WINDS BEHIND THE
FRONT OVERNIGHT THROUGH TUESDAY.
MARINE...
A SMALL CRAFT ADVISORY IS IN EFFECT LATE THIS EVENING THROUGH EARLY
WEDNESDAY EVENING FOR NORTHWEST WINDS THAT WILL GUST BETWEEN 25 AND
30 KNOTS BEHIND A COLD FRONT MOVING THROUGH THE GREAT LAKES REGION.
THE OFFSHORE FETCH WILL KEEP WAVES IN THE 2 TO 4 FOOT RANGE WITH THE
HIGHER WAVES TOWARD OPEN WATER.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 1 AM TO 10 PM CDT TUESDAY FOR
LMZ643>646.
&&
$$
UPDATE...DDV
TONIGHT/TUESDAY AND AVIATION/MARINE...MRC
TUESDAY NIGHT THROUGH MONDAY...GEHRING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
610 PM CDT MON MAR 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 318 PM CDT MON MAR 24 2014
LATEST WATER VAPOR SATELLITE IMAGERY INDICATING SEVERAL SHORTWAVE
TROUGHS EMBEDDED IN NORTHERLY FLOW ALOFT OVER THE NORTHERN PLAINS
AND CENTRAL CANADA. LATEST MOSAIC RADAR SHOWS NUMEROUS SNOW
SHOWERS ACROSS FORECAST AREA BACK INTO CENTRAL MINNESOTA. THIS IS
IN RESPONSE TO STEEP LAPSE RATE UP TO 750MB PER LATEST RAP BUFKIT
SOUNDINGS.
TONIGHT...ANOTHER IMPULSE EMBEDDED IN THE NORTHERLY FLOW ALOFT
WILL MOVE OVER THE FORECAST AREA AND GREAT LAKES REGION. THE
24.12Z GFS/NAM AND 24.18Z BUFKIT SOUNDINGS SUGGEST STEEP LAPSE
RATES UP TO 850MB...500-300MB POTENTIAL VORTICITY ADVECTION AND
FORCING ABOVE 700MB IN ASSOCIATION WITH THE IMPULSE. THIS WILL
CONTINUE THE ISOLATED TO SCATTERED SNOW SHOWERS OVER FORECAST
AREA TO AROUND 09Z TUESDAY. HAVE INTRODUCE THIS TREND INTO THE
FORECAST.
BEHIND SHORTWAVE TROUGH...COLDER AIR WILL FILTER INTO THE AREA
TUESDAY...WITH 925MB TEMPERATURES FALLING INTO THE MINUS TEENS
DEGREES CELSIUS BY 18Z TUESDAY. TEMPERATURES WILL BE WELL BELOW
NORMAL AND HIGH TEMPERATURES EXPECTED TO CLIMB INTO THE TEENS TO
MIDDLE 20S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 318 PM CDT MON MAR 24 2014
FOCUS TURNS TO WEDNESDAY INTO THURSDAY NIGHT...AS NEXT SYSTEM
AFFECTS THE UPPER MIDWEST AND GREAT LAKES REGION. THE 24.12Z NAM
AND GFS CONTINUE TO BE THE MOST PROGRESSIVE AND FARTHER NORTH
PLACEMENT WITH THIS SYSTEM COMPARED TO THE 24.12Z ECMWF AND GEM.
THE 24.12Z MODELS ARE IN AGREEMENT DECENT WARM AIR ADVECTS INTO
THE AREA OUT AHEAD OF THE SYSTEM AND WRAPS INTO THE SYSTEM. THIS
WOULD ALLOW FOR MUCH OF THE PRECIPITATION TO FALL AS RAIN ACROSS
THE FORECAST AREA WEDNESDAY NIGHT INTO THURSDAY. THIS IS EVIDENT
WITH THE 24.12Z GFS/NAM BUFKIT SOUNDINGS SHOWING TEMPERATURES
ABOVE ZERO UP TO 850MB ACROSS MUCH OF THE FORECAST AREA AFTER 06Z
THURSDAY INTO THURSDAY AFTERNOON. THE 24.12Z MODELS INDICATE
SURFACE FRONT PASSAGE LATE THURSDAY AFTERNOON INTO THURSDAY NIGHT
ACROSS FORECAST AREA. THE PRECIPITATION SHOULD TRANSITION TO ALL
SNOW FROM WEST TO EAST ACROSS FORECAST AREA THURSDAY EVENING INTO
THURSDAY NIGHT. HOWEVER...WITH INCONSISTENCIES OF TIMING AND
PLACEMENT OF SYSTEM BY ALL THE MODELS WEDNESDAY NIGHT INTO
THURSDAY NIGHT...CONFIDENCE IN FORECAST AT THIS TIME PERIOD IS
LOW.
FRIDAY INTO SUNDAY MAIN FORECAST CONCERNS ARE TEMPERATURES ACROSS
THE FORECAST AREA. THE 24.12Z GFS/ECMWF BOTH ARE IN AGREEMENT IN
BREAKING DOWN UPPER LEVEL TROUGH OVER THE GREAT LAKES REGION AND
BUILDING SHORTWAVE RIDGE OVER THE NORTHERN PLAINS AND UPPER
MIDWEST THIS WEEKEND. THE MODELS SUGGEST 925MB TEMPERATURES
WARMING TO AROUND PLUS 10 DEGREES CELSIUS BY 00Z SUNDAY OVER
FORECAST AREA. THIS SHOULD ALLOW TEMPERATURES TO BE NEAR OR ABOVE
NORMAL SUNDAY. THEN...THE 14.12Z GFS/ECMWF BEGIN TO DIVERGE EARLY
NEXT WEEK WITH SHORTWAVE TROUGH EMBEDDED IN WEST TO EAST ZONAL
FLOW ALOFT. THE 24.12Z ECMWF MUCH MORE PROGRESSIVE AND STRONGER
WITH SHORTWAVE TROUGH AND INDICATES PRECIPITATION TO OVERSPREAD
THE FORECAST AREA MONDAY. THE 24.12Z GFS IS SLIGHTLY SLOWER AND
WEAKER WITH SHORTWAVE TROUGH AND DELAYS ANY PRECIPITATION INTO THE
FORECAST AREA BY 18Z MONDAY. AT THIS TIME...WILL INTRODUCE PRECIPITATION
CHANCES ACROSS FORECAST AREA SUNDAY NIGHT AND MONDAY.
PRECIPITATION SHOULD REMAIN AS ALL RAIN AS TEMPERATURES REMAIN
WELL ABOVE ZERO DEGREES CELSIUS IN THE NEAR SURFACE BOUNDARY LAYER
TO 800MB PER BUFKIT SOUNDINGS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 610 PM CDT MON MAR 24 2014
LATEST VISIBLE SATELLITE SHOWS A LOT OF DIURNAL CLOUD ELEMENTS
ACROSS MN/NORTHERN PLAINS...PUSHING SOUTHEAST. SOLID...BUT THIN LINE
OF SNOW SHOWERS HAS ALREADY MOVED ACROSS KRST...AND WILL DO THE SAME
AT KLSE BEFORE 00Z. -SHSN WERE SCATTERED POST THE LINE. INITIAL
UPPER LEVEL SHORTWAVE TO SLIDE SOUTH ACROSS THE AREA THIS
EVENING...AIDING IN THE CURRENT PCPN...WITH A SECONDARY WAVE MOVING
IN OVERNIGHT. NOT AS MUCH ASSOCIATED WITH THIS. WITH DIURNAL
ELEMENTS HEAVY IN THE CURRENT SATELLITE/RADAR
IMAGERY...ANTICIPATION IS THAT MUCH OF THIS WILL DIMINISH WITH THE
LOSS OF THE DAYTIME HEATING. LOW LEVEL LAPSE RATES STAYS FAIRLY
STEEP TONIGHT THOUGH...LENDING SOME CREDENCE TO -SHSN CONTINUING.
ANY -SHSN WOULD BE CAPABLE OF BRIEF PERIODS OF IFR/MVFR VSBYS. GOING
TO HANG ONTO TO SOME SHOWERS THIS EVENING...BUT TREND TOWARD VFR FOR
CIGS. EXPECT SCT-BKN CONDITIONS FOR TUE...WITH SC/CU DEVELOPMENT IN
THE LATE MORNING. WINDS WILL STAY FROM THE NORTHWEST...GENERALLY
NEAR OR ABOVE 10 KTS FOR MUCH OF THE TAF PERIOD.
&&
.HYDROLOGY...
ISSUED AT 318 PM CDT MON MAR 24 2014
COLDER AIR IS HELPING WITH SNOW MELT AND ASSOCIATED RUNOFF INTO
AREA RIVERS AND STREAMS. WARMER TEMPERATURES ARE EXPECTED
WEDNESDAY INTO THURSDAY...AND THE THREAT FOR PRECIPITATION. DURING
THIS TIME PERIOD WILL HAVE TO MONITOR THE RIVER LEVELS CLOSELY
FOR RISES AND POSSIBLE FLOODING IF ENOUGH RAIN FALLS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM....DTJ
AVIATION.....RIECK
HYDROLOGY....DTJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 PM CDT SUN MAR 23 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 339 PM CDT SUN MAR 23 2014
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED NORTHWEST FLOW FROM BRITISH COLUMBIA INTO THE MID-ATLANTIC.
THERE ARE A VARIETY OF SHORTWAVES SEEN ON WATER VAPOR THAT ARE
FORECAST TO IMPACT THE AREA OVER THE NEXT COUPLE OF DAYS...ONE
OVER MONTANA...ANOTHER IN CENTRAL ALBERTA...A SHEARED OUT ONE
ALONG THE NUNAVUT/ALBERTA/SASKATCHEWAN BORDER...AND A FINAL ONE
WAY TO THE NORTH OVER THE CANADIAN ARCHIPELAGO. OBSERVATIONS SOME
SNOW AHEAD OF MOST OF THESE SHORTWAVES EXCEPT FOR THE LAST ONE.
PLENTIFUL ARCTIC AIR ALSO EXISTS OVER NUNAVUT INTO THE CANADIAN
ARCHIPELAGO WHERE TEMPERATURES WERE 15 TO 30 BELOW ZERO THIS
MORNING. OVER THE FORECAST AREA...A LARGE AREA OF CANADIAN HIGH
PRESSURE IS IN PLACE. PLENTIFUL DRY AIR EXISTS WITH THIS
HIGH...REFLECTED BY 12Z RAOBS INDICATING PRECIPITABLE WATER VALUES
OF 0.1-0.2 INCHES OR 30-50 PERCENT OF NORMAL. AS A RESULT...SKIES
HAVE BEEN MOSTLY SUNNY TODAY...THOUGH DIURNAL STRATOCUMULUS HAS
DEVELOPED WEST OF THE MS RIVER. DESPITE THE SUN...TEMPERATURES
HAVE ONLY CLIMBED INTO THE MID TEENS TO MID 20S...DUE TO
UNSEASONABLY COLD 925MB TEMPS OF -14 TO - 17C PER 12Z RAOB DATA.
DESPITE THAT WE ARE NOW WITHIN 24 HOURS OF THE EXPECTED MONDAY
SNOW...THE FORECAST REMAINS VERY UNCERTAIN. MUCH OF THE UNCERTAINTY
RELATES TO THE MONTANA AND CENTRAL ALBERTA SHORTWAVES. THE 23.12Z
NAM FOLLOWS SUIT WITH MOST OF ITS PREVIOUS RUNS...ALSO SIMILAR TO
THE 23.12Z CANADIAN AND 23.19Z RAP...NEARLY PHASING THE TWO
SHORTWAVES AND BRINGING THEM THROUGH THE AREA MONDAY MORNING. A WARM
ADVECTION WING DEVELOPS AHEAD OF THEM...AFFECTING THE FORECAST AREA
LATE TONIGHT THROUGH EARLY MONDAY AFTERNOON. LOCATIONS ACROSS
NORTHEAST IOWA WOULD SEE THE HEAVIEST PRECIPITATION ALONG THE TRACK
WITH 1-3 INCHES COMMON PER NAM COBB OUTPUT. ON THE OTHER SIDE OF
THIS IS THE 23.12Z GFS/ECMWF WHICH ARE MUCH DRIER SCENARIOS...
ESPECIALLY THE ECMWF AS IT KEEPS THE TWO SHORTWAVES UNPHASED. SOME
OF THE DRIER LOOK IS ALSO A REFLECTION OF THE SHORTWAVES RUNNING
INTO THE CURRENT DRY AIRMASS IN PLACE. GIVEN THE SPREAD OF SCENARIOS
AND EACH ONE EQUALLY PLAUSIBLE...FELT A COMPROMISE IS WARRANTED...
WHICH IS SIMILAR TO THE PREVIOUS FORECAST. THIS RESULTS IN ABOUT 1-2
INCHES MAINLY WEST OF THE MS RIVER WITH LESS THAN 1 INCH EAST.
AFTER THE MONTANA/CENTRAL ALBERTA SHORTWAVES PASS EARLY IN THE
AFTERNOON...ATTENTION THEN FOCUSES ON A COLD FRONT DROPPING
SOUTHEAST TOWARDS THE FORECAST AREA IN THE AFTERNOON...ASSOCIATED
WITH THE NEXT SHORTWAVE DROPPING OUT OF
NUNAVUT/ALBERTA/SASKATCHEWAN. A SURGE OF WARMER 925MB AIR OF -4 TO
-7C AHEAD OF THE FRONT PLUS WHAT MIGHT BE A PERIOD OF SUN SHOULD
PUSH TEMPERATURES INTO THE 30S. LINGERING MOISTURE AROUND COMBINED
WITH THE APPROACHING SHORTWAVE AND COLD FRONT WILL YIELD A STEEP LOW
LEVEL LAPSE RATE SITUATION...RESULTING IN A BAND OF SCATTERED TO
PERHAPS NUMEROUS SNOW SHOWERS BY LATE IN THE AFTERNOON. THIS
SCENARIO IS WELL AGREED UPON BY MODELS. COULD SEE A QUICK 1/2 TO 1
INCH FROM THIS SNOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 339 PM CDT SUN MAR 23 2014
AFTER ALL OF THE UNCERTAINTY IN THE SHORT TERM...MODELS GET MORE IN
AGREEMENT FOR MONDAY NIGHT THROUGH WEDNESDAY...PRIOR TO THE NEXT
SYSTEM EXPECTED TO IMPACT THE REGION ON THURSDAY.
THE SHORTWAVE CURRENTLY ALONG THE NUNAVUT/ALBERTA/SASKATCHEWAN
BORDER IS PROGGED TO DROP THROUGH THE AREA LATE MONDAY EVENING. THIS
SHORTWAVE COMBINED WITH CONTINUED STEEP LOW LEVEL LAPSE RATES AHEAD
OF IT WILL CONTINUE TO YIELD THE POTENTIAL FOR SNOW SHOWERS. MUCH OF
THE SNOW SHOULD END BY 08Z TUE. IN THE WAKE OF THIS SHORTWAVE A
SURGE OF COLDER 925MB AIR COMES IN WITH TEMPS DROPPING TO -8 TO
-12C. NORTHWEST WINDS INCREASE AS WELL. EVEN COLDER AIR FOLLOWS FOR
TUESDAY MORNING AS THE SHORTWAVE OVER THE CANADIAN ARCHIPELAGO
PLUNGES SOUTH THROUGH THE FORECAST AREA. 925MB TEMPS FALL TO -12 TO
-15C AT A MINIMUM BY 15Z TUE...WITH THE 23.12Z GFS/NAM EVEN
SUGGESTING -15 TO -18C. A BRISK NORTHWEST WIND ACCOMPANIES THIS
ARCTIC AIR SHOT...SO NEEDLESS TO SAY...TUESDAY LOOKS LIKE ANOTHER
CHILLY DAY SIMILAR TO TODAY AND POSSIBLY EVEN SLIGHTLY COLDER. THE
ONLY POSITIVE IS THERE SHOULD BE A DECENT AMOUNT OF SUN INTERMIXED
WITH DAYTIME STRATOCUMULUS. HAVING A COLD TUESDAY...RECENT LIGHT
SNOW AND AN ARCTIC SURFACE HIGH PRESSURE RIDGE MOVING ACROSS AT
NIGHT SPELLS POTENTIAL FOR REALLY CHILLY CONDITIONS TUESDAY
NIGHT...PARTICULARLY OVER WISCONSIN. A FEW BELOW ZERO READINGS SEEM
LIKELY IN CENTRAL WISCONSIN. TEMPERATURES MAY CLIMB WEST OF THE
RIVER LATE AS RETURN FLOW SETS UP THERE.
A PATTERN CHANGE IS SET TO TAKE HOLD FOR WEDNESDAY AND BEYOND AS A
SERIES OF FAIRLY VIGOROUS LONG WAVE TROUGHS COME OFF THE PACIFIC AND
MARCH THEIR WAY ACROSS THE U.S..
THE FIRST LONG WAVE TROUGH COMING INTO THE WESTERN U.S. ON WEDNESDAY
CAUSES UPPER RIDGING TO BUILD OVER THE FORECAST AREA DURING THE
AFTERNOON. VERY STRONG WARM ADVECTION IS SUGGESTED BY MODELS BETWEEN
12Z WED AND 00Z THU WITH 925-850MB TEMPS CLIMBING AROUND 8C AREA
WIDE. THIS WARMER AIR COMES IN ON A STRENGTHENING LOW LEVEL JET WITH
THE ECMWF AND NAM DEPICTING 925MB WINDS REACHING 40 KT OVER THE
FAVORED WIND PRONE AREAS BY 00Z. GOOD MIXING ON SOUNDINGS TOO
SUGGESTING POTENTIAL NEED FOR ADVISORY DUE TO GUSTS. THERE HAVE BEEN
SUGGESTIONS TOO FROM THE GFS/SREF OF ISENTROPICALLY INDUCED SNOW
NORTH OF I-90 IN WI DURING THE AFTERNOON AS THAT LOW LEVEL JET
INCREASES. THE ECMWF/NAM REMAIN DRY...THOUGH. FOR NOW HAVE KEPT IN
SOME LOW CHANCES. WEDNESDAY NIGHT LOOKS BREEZY WITH NEAR STEADY
TEMPERATURES AS LOW LEVEL MOISTURE GRADUALLY INCREASES. THERE COULD
BE ENOUGH ISENTROPIC LIFT TO GENERATE SOME LIGHT PRECIP...WHICH WITH
A WARM LAYER PLAYING HAVOC WITH THE TYPE...A WINTRY MIX IS POSSIBLE
MAINLY NORTH OF I-94. THE WEATHER THEN GETS MUCH MORE INTERESTING
FOR THURSDAY AND POSSIBLY INTO FRIDAY...RESULTING FROM THE STRONG
SHORTWAVE AT THE BASE OF THE TROUGH LIFTS THROUGH THE FORECAST AREA.
STILL PLENTY OF MODEL SPREAD ON THE TIMING AND STRENGTH OF THIS
SHORTWAVE...WITH THE GFS REMAINING MOST PROGRESSIVE AND THE ECMWF
SLOWEST. EITHER SOLUTION BRINGS UP PLENTY OF GULF MOISTURE...AND THE
PREVIOUS FORECAST THINKING OF 0.5-1 INCH OF LIQUID QPF STILL LOOKS
REASONABLE. MUCH OF THE QPF LOOKS TO COME ON THE DEFORMATION SIDE OF
THE SYSTEM...WHICH APPEARS TO BE SNOW ON THE NORTHWEST SIDE AND RAIN
ON THE SOUTHEAST SIDE. THE ECMWF SOLUTION BEING STRONGER COULD
PRODUCE AT LEAST ADVISORY IF NOT WARNING SNOWFALL AMOUNTS. PLENTY OF
WIND TOO IN THE ECMWF SCENARIO TO ADD TO THE SNOW HAZARD. THE RAIN
TOO COULD LEAD TO RUNOFF PROBLEMS.
AFTER THE THURSDAY/FRIDAY SYSTEM PASSES...UPPER RIDGING LOOKS TO
BUILD BACK INTO THE REGION FOR THE WEEKEND AS THE NEXT UPPER TROUGH
COMES INTO THE WESTERN U.S.. THE WEEKEND FOR THE MOST PART LOOKS DRY
WITH A WARMING TREND AS THE RIDGE BUILDS IN. THE WARMING WILL REALLY
BE NOTICED ON SUNDAY AS 850MB STANDARDIZED ANOMALIES FROM THE 23.12Z
ECMWF/GFS REACH +2... SOMETHING NOT SEEN FOR MUCH OF THE WINTER OR
SPRING THUS FAR. WITH A BREEZY SOUTHWEST WIND...HIGHS IN THE 50S
WITH A FEW 60S COULD OCCUR. SEE THE HYDROLOGY DISCUSSION BELOW FOR
IMPACTS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 600 PM CDT SUN MAR 23 2014
SNOW MOVES IN FOR MONDAY...BUT WILL COME IN TWO WAVES. FIRST...A
SHORTWAVE WILL SWING ACROSS IA LATE TONIGHT/MONDAY MORNING. MOST OF
THIS SYSTEM/S SNOW WILL STAY CONFINED TO IOWA...BUT COULD SPREAD FAR
ENOUGH NORTH TO IMPACT KRST FOR A FEW HOURS. CIGS/VSBYS COULD DIP
INTO THE MVFR CATEGORY WITH THE -SN.
ANOTHER SHORTWAVE TROUGH THEN MOVES IN FOR THE MID AFTERNOON/EVENING
HOURS...SHIFTING OUT OF THE DAKOTAS. HEFTY LOW LEVEL LAPSE RATES
WILL PROVIDE SOME NEAR SFC INSTABILITY AND MODELED SOUNDINGS SUGGEST
AMPLE SATURATION FOR CLOUD/PCPN PRODUCTION. EXPECT THIS ACTIVITY TO
BE MORE CELLULAR/SHOWERY. THIS COULD RESULT IN A HALF HOUR OF 1-2SM
-SN...FOLLOWED BY P6SM FOR A PERIOD...ETC ETC. SOMETHING TO WATCH.
WILL LIKELY COVER WITH MVFR -SHSN CONDITIONS FOR NOW.
&&
.HYDROLOGY...
ISSUED AT 339 PM CDT SUN MAR 23 2014
ISSUE 1...TREMPEALEAU RIVER AT DODGE. THE RIVER HAS BEEN CLIMBING
AT DODGE SINCE ABOUT 00Z ON THE 21ST...DESPITE A FEW COLD DAYS
NOW WHICH HAS CAUSED GAUGES UPSTREAM TO FALL. THERE IS ICE ON THE
RIVER...THUS THE THINKING IS THERE MIGHT BE AN ICE JAM DOWNSTREAM
OF DODGE. HAVE ISSUED A RIVER FLOOD WARNING AT DODGE WHEN IT
REACHED 8.9 FT...HOWEVER...NOW THE RIVER JUST STARTED TO FALL
SLIGHTLY. GIVEN THE UNCERTAINTY ON HOW THIS POSSIBLE ICE JAM IS
AFFECTING RIVER FLOW...WILL BE KEEPING THE WARNING GOING.
ISSUE 2...THE WARM UP AND PRECIPITATION FOR THURSDAY AND POSSIBLY
INTO FRIDAY. MODELS ARE SUGGESTING BETWEEN 1/2 - 1 INCH OF LIQUID
EQUIVALENT...HEAVIEST OVER THE NORTHWEST HALF OF THE FORECAST
AREA. RIGHT NOW IT APPEARS THE RAIN ASPECT TO THIS PRECIPITATION
WOULD OCCUR OVER THE SOUTHEAST HALF OF THE FORECAST AREA...WHICH
ALTHOUGH MOSTLY SNOW FREE HAS PLENTY OF FROST IN THE GROUND TO
TURN MUCH OF THE RAIN TO RUNOFF. NEEDLESS TO SAY...WORTH
MONITORING.
ISSUE 3...ABOVE NORMAL WARMTH FOR SUNDAY. WITH TEMPERATURES
CLIMBING INTO THE 50S AND POSSIBLY 60S...WE WILL REALLY HAVE TO
WATCH FOR POSSIBLE RIVER FLOODING ALONG THE TREMPEALEAU AND
BLACK GIVEN DEEPER SNOWPACK IN THE HEADWATER AREA. ANY SNOW FROM
THURSDAY/FRIDAY COULD ALSO CAUSE FLOODING CONCERNS DUE TO RAPID
MELTING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RIECK
HYDROLOGY....AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
339 PM CDT SUN MAR 23 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 339 PM CDT SUN MAR 23 2014
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED NORTHWEST FLOW FROM BRITISH COLUMBIA INTO THE MID-ATLANTIC.
THERE ARE A VARIETY OF SHORTWAVES SEEN ON WATER VAPOR THAT ARE
FORECAST TO IMPACT THE AREA OVER THE NEXT COUPLE OF DAYS...ONE
OVER MONTANA...ANOTHER IN CENTRAL ALBERTA...A SHEARED OUT ONE
ALONG THE NUNAVUT/ALBERTA/SASKATCHEWAN BORDER...AND A FINAL ONE
WAY TO THE NORTH OVER THE CANADIAN ARCHIPELAGO. OBSERVATIONS SOME
SNOW AHEAD OF MOST OF THESE SHORTWAVES EXCEPT FOR THE LAST ONE.
PLENTIFUL ARCTIC AIR ALSO EXISTS OVER NUNAVUT INTO THE CANADIAN
ARCHIPELAGO WHERE TEMPERATURES WERE 15 TO 30 BELOW ZERO THIS
MORNING. OVER THE FORECAST AREA...A LARGE AREA OF CANADIAN HIGH
PRESSURE IS IN PLACE. PLENTIFUL DRY AIR EXISTS WITH THIS
HIGH...REFLECTED BY 12Z RAOBS INDICATING PRECIPITABLE WATER VALUES
OF 0.1-0.2 INCHES OR 30-50 PERCENT OF NORMAL. AS A RESULT...SKIES
HAVE BEEN MOSTLY SUNNY TODAY...THOUGH DIURNAL STRATOCUMULUS HAS
DEVELOPED WEST OF THE MS RIVER. DESPITE THE SUN...TEMPERATURES
HAVE ONLY CLIMBED INTO THE MID TEENS TO MID 20S...DUE TO
UNSEASONABLY COLD 925MB TEMPS OF -14 TO - 17C PER 12Z RAOB DATA.
DESPITE THAT WE ARE NOW WITHIN 24 HOURS OF THE EXPECTED MONDAY
SNOW...THE FORECAST REMAINS VERY UNCERTAIN. MUCH OF THE UNCERTAINTY
RELATES TO THE MONTANA AND CENTRAL ALBERTA SHORTWAVES. THE 23.12Z
NAM FOLLOWS SUIT WITH MOST OF ITS PREVIOUS RUNS...ALSO SIMILAR TO
THE 23.12Z CANADIAN AND 23.19Z RAP...NEARLY PHASING THE TWO
SHORTWAVES AND BRINGING THEM THROUGH THE AREA MONDAY MORNING. A WARM
ADVECTION WING DEVELOPS AHEAD OF THEM...AFFECTING THE FORECAST AREA
LATE TONIGHT THROUGH EARLY MONDAY AFTERNOON. LOCATIONS ACROSS
NORTHEAST IOWA WOULD SEE THE HEAVIEST PRECIPITATION ALONG THE TRACK
WITH 1-3 INCHES COMMON PER NAM COBB OUTPUT. ON THE OTHER SIDE OF
THIS IS THE 23.12Z GFS/ECMWF WHICH ARE MUCH DRIER SCENARIOS...
ESPECIALLY THE ECMWF AS IT KEEPS THE TWO SHORTWAVES UNPHASED. SOME
OF THE DRIER LOOK IS ALSO A REFLECTION OF THE SHORTWAVES RUNNING
INTO THE CURRENT DRY AIRMASS IN PLACE. GIVEN THE SPREAD OF SCENARIOS
AND EACH ONE EQUALLY PLAUSIBLE...FELT A COMPROMISE IS WARRANTED...
WHICH IS SIMILAR TO THE PREVIOUS FORECAST. THIS RESULTS IN ABOUT 1-2
INCHES MAINLY WEST OF THE MS RIVER WITH LESS THAN 1 INCH EAST.
AFTER THE MONTANA/CENTRAL ALBERTA SHORTWAVES PASS EARLY IN THE
AFTERNOON...ATTENTION THEN FOCUSES ON A COLD FRONT DROPPING
SOUTHEAST TOWARDS THE FORECAST AREA IN THE AFTERNOON...ASSOCIATED
WITH THE NEXT SHORTWAVE DROPPING OUT OF
NUNAVUT/ALBERTA/SASKATCHEWAN. A SURGE OF WARMER 925MB AIR OF -4 TO
-7C AHEAD OF THE FRONT PLUS WHAT MIGHT BE A PERIOD OF SUN SHOULD
PUSH TEMPERATURES INTO THE 30S. LINGERING MOISTURE AROUND COMBINED
WITH THE APPROACHING SHORTWAVE AND COLD FRONT WILL YIELD A STEEP LOW
LEVEL LAPSE RATE SITUATION...RESULTING IN A BAND OF SCATTERED TO
PERHAPS NUMEROUS SNOW SHOWERS BY LATE IN THE AFTERNOON. THIS
SCENARIO IS WELL AGREED UPON BY MODELS. COULD SEE A QUICK 1/2 TO 1
INCH FROM THIS SNOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 339 PM CDT SUN MAR 23 2014
AFTER ALL OF THE UNCERTAINTY IN THE SHORT TERM...MODELS GET MORE IN
AGREEMENT FOR MONDAY NIGHT THROUGH WEDNESDAY...PRIOR TO THE NEXT
SYSTEM EXPECTED TO IMPACT THE REGION ON THURSDAY.
THE SHORTWAVE CURRENTLY ALONG THE NUNAVUT/ALBERTA/SASKATCHEWAN
BORDER IS PROGGED TO DROP THROUGH THE AREA LATE MONDAY EVENING. THIS
SHORTWAVE COMBINED WITH CONTINUED STEEP LOW LEVEL LAPSE RATES AHEAD
OF IT WILL CONTINUE TO YIELD THE POTENTIAL FOR SNOW SHOWERS. MUCH OF
THE SNOW SHOULD END BY 08Z TUE. IN THE WAKE OF THIS SHORTWAVE A
SURGE OF COLDER 925MB AIR COMES IN WITH TEMPS DROPPING TO -8 TO
-12C. NORTHWEST WINDS INCREASE AS WELL. EVEN COLDER AIR FOLLOWS FOR
TUESDAY MORNING AS THE SHORTWAVE OVER THE CANADIAN ARCHIPELAGO
PLUNGES SOUTH THROUGH THE FORECAST AREA. 925MB TEMPS FALL TO -12 TO
-15C AT A MINIMUM BY 15Z TUE...WITH THE 23.12Z GFS/NAM EVEN
SUGGESTING -15 TO -18C. A BRISK NORTHWEST WIND ACCOMPANIES THIS
ARCTIC AIR SHOT...SO NEEDLESS TO SAY...TUESDAY LOOKS LIKE ANOTHER
CHILLY DAY SIMILAR TO TODAY AND POSSIBLY EVEN SLIGHTLY COLDER. THE
ONLY POSITIVE IS THERE SHOULD BE A DECENT AMOUNT OF SUN INTERMIXED
WITH DAYTIME STRATOCUMULUS. HAVING A COLD TUESDAY...RECENT LIGHT
SNOW AND AN ARCTIC SURFACE HIGH PRESSURE RIDGE MOVING ACROSS AT
NIGHT SPELLS POTENTIAL FOR REALLY CHILLY CONDITIONS TUESDAY
NIGHT...PARTICULARLY OVER WISCONSIN. A FEW BELOW ZERO READINGS SEEM
LIKELY IN CENTRAL WISCONSIN. TEMPERATURES MAY CLIMB WEST OF THE
RIVER LATE AS RETURN FLOW SETS UP THERE.
A PATTERN CHANGE IS SET TO TAKE HOLD FOR WEDNESDAY AND BEYOND AS A
SERIES OF FAIRLY VIGOROUS LONG WAVE TROUGHS COME OFF THE PACIFIC AND
MARCH THEIR WAY ACROSS THE U.S..
THE FIRST LONG WAVE TROUGH COMING INTO THE WESTERN U.S. ON WEDNESDAY
CAUSES UPPER RIDGING TO BUILD OVER THE FORECAST AREA DURING THE
AFTERNOON. VERY STRONG WARM ADVECTION IS SUGGESTED BY MODELS BETWEEN
12Z WED AND 00Z THU WITH 925-850MB TEMPS CLIMBING AROUND 8C AREA
WIDE. THIS WARMER AIR COMES IN ON A STRENGTHENING LOW LEVEL JET WITH
THE ECMWF AND NAM DEPICTING 925MB WINDS REACHING 40 KT OVER THE
FAVORED WIND PRONE AREAS BY 00Z. GOOD MIXING ON SOUNDINGS TOO
SUGGESTING POTENTIAL NEED FOR ADVISORY DUE TO GUSTS. THERE HAVE BEEN
SUGGESTIONS TOO FROM THE GFS/SREF OF ISENTROPICALLY INDUCED SNOW
NORTH OF I-90 IN WI DURING THE AFTERNOON AS THAT LOW LEVEL JET
INCREASES. THE ECMWF/NAM REMAIN DRY...THOUGH. FOR NOW HAVE KEPT IN
SOME LOW CHANCES. WEDNESDAY NIGHT LOOKS BREEZY WITH NEAR STEADY
TEMPERATURES AS LOW LEVEL MOISTURE GRADUALLY INCREASES. THERE COULD
BE ENOUGH ISENTROPIC LIFT TO GENERATE SOME LIGHT PRECIP...WHICH WITH
A WARM LAYER PLAYING HAVOC WITH THE TYPE...A WINTRY MIX IS POSSIBLE
MAINLY NORTH OF I-94. THE WEATHER THEN GETS MUCH MORE INTERESTING
FOR THURSDAY AND POSSIBLY INTO FRIDAY...RESULTING FROM THE STRONG
SHORTWAVE AT THE BASE OF THE TROUGH LIFTS THROUGH THE FORECAST AREA.
STILL PLENTY OF MODEL SPREAD ON THE TIMING AND STRENGTH OF THIS
SHORTWAVE...WITH THE GFS REMAINING MOST PROGRESSIVE AND THE ECMWF
SLOWEST. EITHER SOLUTION BRINGS UP PLENTY OF GULF MOISTURE...AND THE
PREVIOUS FORECAST THINKING OF 0.5-1 INCH OF LIQUID QPF STILL LOOKS
REASONABLE. MUCH OF THE QPF LOOKS TO COME ON THE DEFORMATION SIDE OF
THE SYSTEM...WHICH APPEARS TO BE SNOW ON THE NORTHWEST SIDE AND RAIN
ON THE SOUTHEAST SIDE. THE ECMWF SOLUTION BEING STRONGER COULD
PRODUCE AT LEAST ADVISORY IF NOT WARNING SNOWFALL AMOUNTS. PLENTY OF
WIND TOO IN THE ECMWF SCENARIO TO ADD TO THE SNOW HAZARD. THE RAIN
TOO COULD LEAD TO RUNOFF PROBLEMS.
AFTER THE THURSDAY/FRIDAY SYSTEM PASSES...UPPER RIDGING LOOKS TO
BUILD BACK INTO THE REGION FOR THE WEEKEND AS THE NEXT UPPER TROUGH
COMES INTO THE WESTERN U.S.. THE WEEKEND FOR THE MOST PART LOOKS DRY
WITH A WARMING TREND AS THE RIDGE BUILDS IN. THE WARMING WILL REALLY
BE NOTICED ON SUNDAY AS 850MB STANDARDIZED ANOMALIES FROM THE 23.12Z
ECMWF/GFS REACH +2... SOMETHING NOT SEEN FOR MUCH OF THE WINTER OR
SPRING THUS FAR. WITH A BREEZY SOUTHWEST WIND...HIGHS IN THE 50S
WITH A FEW 60S COULD OCCUR. SEE THE HYDROLOGY DISCUSSION BELOW FOR
IMPACTS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1227 PM CDT SUN MAR 23 2014
A COUPLE OF AVIATION CONCERNS NEXT 24 HOURS. IN THE NEAR
TERM...STRATOCUMULUS WITH BASES 2O00 TO 3000 FT HAS DEVELOPED
ACROSS MUCH OF CENTRAL AND SOUTHERN MINNESOTA...AND WILL SLOWLY
MOVE OVER KRST/KLSE THIS AFTERNOON. THIS IS NOT WELL REPRESENTED
IN FORECAST SOUNDINGS...BUT EXPECTING THIS CLOUD DECK TO
ER0DE OR MOVE OUT OF THE AREA TOWARD 00Z. NEXT CONCERN IS
ACCUMULATING SNOW POTENTIAL AND CEILING/VISIBILITY RESTRICTIONS
MONDAY. LOOK FOR HIGH/MID LEVEL CLOUDS TO SPREAD OVER THE AREA
TONIGHT...AND LIGHT SNOW TO LIKELY BEGIN IN THE 09-12Z PERIOD AT
KRST. THERE WILL BE SOME DRY AIR TO OVERCOME INITIALLY...AND THIS
WILL LIMIT VISIBILITY/CEILING RESTRICTIONS AT FIRST AND LOWER
CONFIDENCE SOMEWHAT. TOWARD DAYBREAK...AND THROUGHOUT THE COURSE
OF THE MORNING...SATURATION AND LIFT INCREASE ENOUGH FOR IFR
CONDITIONS AT KRST THOUGH THE HIGHER IMPACTS WILL LIKELY BE TO THE
SOUTH. AT KLSE...DRY AIR AND LACK OF STRONG SATURATION/LIFT IS
EXPECTED TO EXTEND VFR CONDITIONS THROUGH THE PERIOD BUT COULD
NOT RULE OUT MVFR CEILINGS/VISIBILITY BY 18Z.
&&
.HYDROLOGY...
ISSUED AT 339 PM CDT SUN MAR 23 2014
ISSUE 1...TREMPEALEAU RIVER AT DODGE. THE RIVER HAS BEEN CLIMBING
AT DODGE SINCE ABOUT 00Z ON THE 21ST...DESPITE A FEW COLD DAYS
NOW WHICH HAS CAUSED GAUGES UPSTREAM TO FALL. THERE IS ICE ON THE
RIVER...THUS THE THINKING IS THERE MIGHT BE AN ICE JAM DOWNSTREAM
OF DODGE. HAVE ISSUED A RIVER FLOOD WARNING AT DODGE WHEN IT
REACHED 8.9 FT...HOWEVER...NOW THE RIVER JUST STARTED TO FALL
SLIGHTLY. GIVEN THE UNCERTAINTY ON HOW THIS POSSIBLE ICE JAM IS
AFFECTING RIVER FLOW...WILL BE KEEPING THE WARNING GOING.
ISSUE 2...THE WARM UP AND PRECIPITATION FOR THURSDAY AND POSSIBLY
INTO FRIDAY. MODELS ARE SUGGESTING BETWEEN 1/2 - 1 INCH OF LIQUID
EQUIVALENT...HEAVIEST OVER THE NORTHWEST HALF OF THE FORECAST
AREA. RIGHT NOW IT APPEARS THE RAIN ASPECT TO THIS PRECIPITATION
WOULD OCCUR OVER THE SOUTHEAST HALF OF THE FORECAST AREA...WHICH
ALTHOUGH MOSTLY SNOW FREE HAS PLENTY OF FROST IN THE GROUND TO
TURN MUCH OF THE RAIN TO RUNOFF. NEEDLESS TO SAY...WORTH
MONITORING.
ISSUE 3...ABOVE NORMAL WARMTH FOR SUNDAY. WITH TEMPERATURES
CLIMBING INTO THE 50S AND POSSIBLY 60S...WE WILL REALLY HAVE TO
WATCH FOR POSSIBLE RIVER FLOODING ALONG THE TREMPEALEAU AND
BLACK GIVEN DEEPER SNOWPACK IN THE HEADWATER AREA. ANY SNOW FROM
THURSDAY/FRIDAY COULD ALSO CAUSE FLOODING CONCERNS DUE TO RAPID
MELTING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....ZT
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
430 AM EDT Tue Mar 25 2014
.Near Term [Through Today]...
Latest MSAS and RAP analysis at 07z indicated that a surface low was
beginning to take shape just east of the Florida peninsula. A
surface trough extending from near AAF north-northeast to W NC was
maintaining light surface winds and higher dew points across our area
early this morning. Meanwhile, drier and cooler air was beginning to
make a more substantial push into the rest of AL and MS as the
surface pressure gradient begins to increase between the developing
low and a high building into the Plains. This drier air should begin
arriving into our area over the next 6 hours, and will help scour
out clouds from west to east. This process is likely already
beginning per 11-3.9 micron satellite loops.
Therefore, we expect a mostly sunny day. As the surface cyclone
begins to rapidly deepen off the coastal Carolinas and the surface
ridge axis moves closer to the Mississippi River, the pressure
gradient should increase markedly - with NW winds likely to reach
15-25 mph during the afternoon hours. Along with gusts up to 30-35
mph, this falls short of our Wind Advisory criteria. Basically, we
are expecting a breezy day, but no headlines are currently
anticipated. CAA in the boundary layer will continue through the
day, and thus that layer should be slightly cooler in the mid-late
afternoon. As a result, we placed the warmest temperatures closer
to midday, with highs overall in the 60s, and a small area of low
70s in the eastern Florida Big Bend and immediate Valdosta area.
.Short Term [Tonight Through Thursday]...
The system developing off the FL coast is destined to bomb in
rather spectacular fashion as it races northeastward well off the
Eastern Seaboard. In the wake of the low, strong high pressure
will build southeast to the Tennessee Valley by Wednesday morning.
This airmass is of modified arctic origin and will bring
unseasonably cold temperatures to the Gulf Coast. The high
position is not ideal for efficient radiational cooling, but we
should see enough cold advection to bring temps down to around
freezing by dawn Wednesday across our northern zones. The coldest
areas in Coffee County may see the required 2-hr durations for a
warning, but most areas are expected to only just touch freezing.
Because of the marginal nature of this event, we plan to leave the
freeze watch in place after coordination with WFO JAX and let the
day shift make the final call after they get a look at one more
suite of guidance. People that have sensitive plants and are
concerned about freezing temps should not wait for the warning to
begin taking protective actions. A few spots could even see some
frost, which would be another concern, but the current thinking is
that will see just enough wind to prevent frost formation in most
areas, and particularly in wooded and urban areas, which are also
less likely to see freezing temps. Daytime highs on Wednesday will
only reach the upper 50s in AL and GA and lower 60s in FL. This is
below normal even for January and some 13-15 degrees below seasonal
levels.
The surface high will build east and move off the NC coast by
Thursday afternoon. This will swing low level winds around to
onshore which will allow temps to moderate. Min temps will mainly be
in the upper 30s inland Wednesday night. We cannot rule out some
patchy frost over the Suwannee Valley early Thursday morning where
some mid 30s will be possible. After that, afternoon temps will
recover nicely to the upper 60s and lower 70s. We will also maintain
a slight chance for showers on Thursday for the southern zones.
.Long Term [Thursday Night Through Tuesday]...
We`ll transition out of an unseasonably cool and dry pattern into
a wet pattern with more seasonable temperatures through the
extended range forecast. A frontal system will enter the Tri-State
region on Friday, and not completely clear out until sometime on
Sunday when conditions will begin to dry out once again.
&&
.Aviation...
[Through 06Z Wednesday] Any lingering MVFR or low-end VFR CIGS this
morning should quickly dissipate by 12-15z. Thereafter, we expect
clear skies and VFR conditions. Winds should be out of the northwest
at about 310-330 degrees today, and will be gusty especially from
15-23z. Maximum gusts could reach into the 25-30 knot range, which
could cause some crosswind concerns on SW-NE or W-E runways. Winds
should begin to diminish after 23z.
&&
.Marine...
Deepening low pressure off the Southeast U.S. coast will combine
with strong high pressure building into the Mississippi and
Tennessee Valleys to produce a strengthening pressure gradient
across the Northeast Gulf of Mexico today. Winds will increase to
small craft advisory levels and remain elevated through the night.
Conditions will briefly subside below headline criteria Wednesday
afternoon before increasing to cautionary or marginal advisory
levels Wednesday night into Friday. This time the winds will be
onshore ahead of our next frontal system which will reach or cross
the waters on Saturday.
&&
.Fire Weather...
Dry air should begin arriving today, and in particular this
afternoon. Although forecast models are a little inconsistent in how
low to drop dew points, the most likely scenario creates widespread
minimum RH of around 23-25%. RH values that low put red flag
criteria in play in all of our zones today. Details follow.
* For Alabama: we should see a combination of RH below 25% and winds
of 20 mph. Therefore, a Red Flag Warning will be issued for today.
* For Georgia: it appears likely that we will see RH reach 25% in
combination with winds of at least 15 mph. The questionable part
of the criteria for today will be 10-hr fuel moisture. Yesterday,
these levels dropped to around 7% in the mid-late afternoon near
the northern part of our forecast area at Americus, and were
slightly higher (8%) at Camilla. Based on dry, windy, and sunny
weather today and a forecast for 6% fuel moisture at Americus
from the GA Forestry Commission - we expect that northern parts
of our area may reach red flag criteria. However, the values are
likely to be higher at Camilla and Adel. Therefore the RFW area
that has been issued for SW GA was placed further north and
coordinated with WFO FFC.
* For Florida: forecast ERC values are not sufficiently high to
warrant a Red Flag Warning for any combination of criteria.
By tomorrow, winds will diminish, which makes it unlikely that red
flag conditions will occur Wednesday in our GA or FL zones. However,
long durations of low RH may occur in SE Alabama so a Fire Weather
Watch was posted for those areas.
&&
.Hydrology...
Most rivers across the region have crested and are slowly receding
with only a few points still above flood stage. The Ochlockonee at
Havana and Aucilla at Lamont will fall below flood stage later
today. The Withlacoochee near Quitman doesn`t have far to go either.
The Lower Withlacoochee and Suwannee Rivers continue to rise and
will likely continue to do so through the weekend. However, the
chance of flooding is low.
For the latest river stages and forecasts, please visit:
water.weather.gov/ahps2/index.php?wfo=tae
&&
.Preliminary Point Temps/PoPs...
Tallahassee 69 34 62 39 71 / 10 0 0 0 20
Panama City 67 39 60 47 68 / 10 0 0 10 20
Dothan 63 32 60 41 70 / 0 0 0 0 10
Albany 64 31 59 39 70 / 0 0 0 0 10
Valdosta 71 32 61 38 73 / 10 0 0 0 10
Cross City 72 34 62 36 72 / 10 0 0 0 20
Apalachicola 69 38 60 46 67 / 10 0 0 0 20
&&
.TAE Watches/Warnings/Advisories...
FL...Freeze Watch from late tonight through Wednesday morning for
Holmes-Inland Walton.
GA...Freeze Watch from late tonight through Wednesday morning for
Baker-Ben Hill-Berrien-Calhoun-Clay-Colquitt-Cook-Dougherty-
Early-Irwin-Lee-Miller-Mitchell-Quitman-Randolph-Terrell-
Tift-Turner-Worth.
Red Flag Warning from 2 PM this afternoon to 8 PM EDT this
evening for Ben Hill-Calhoun-Clay-Dougherty-Early-Lee-
Quitman-Randolph-Terrell-Turner-Worth.
AL...Freeze Watch from late tonight through Wednesday morning for
Coffee-Dale-Geneva-Henry-Houston.
Red Flag Warning from 1 PM this afternoon to 7 PM CDT this
evening for Coffee-Dale-Geneva-Henry-Houston.
Fire Weather Watch from Wednesday afternoon through Wednesday
evening for Coffee-Dale-Geneva-Henry-Houston.
GM...Small Craft Advisory from 11 AM this morning to 11 AM EDT
Wednesday for Apalachee Bay-Coastal waters From Ochlockonee
River to Apalachicola FL out to 20 NM-Coastal waters from
Suwannee River to Keaton Beach FL out 20 NM-Coastal waters
from Apalachicola to Destin FL out 20 NM-Waters from
Suwannee River to Apalachicola FL from 20 to 60 NM-Waters
from Apalachicola to Destin FL from 20 to 60 NM.
&&
$$
NEAR TERM...LAMERS
SHORT TERM...WOOL
LONG TERM...HARRIGAN
AVIATION...LAMERS
MARINE...WOOL
FIRE WEATHER...LAMERS
HYDROLOGY...WOOL
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
357 AM CDT TUE MAR 25 2014
.DISCUSSION...
NARROW BUT INTENSE BAND OF SNOW ALONG COLD FRONT WILL CONTINUE TO
MOVE ACROSS THE SOUTHEAST HALF OF THE CWA OVER THE NEXT FEW HOURS.
GENERALLY QUICK DROP TO 1/4SM VIS WITH 0.5-1.0 INCH ACCUMULATIONS IN
20 MINUTES WITHIN THE HEAVIER SNOW SHOWERS. EXTRAPOLATION OF RADAR
LOOP INDICATES BAND SHOULD EXIT ALL BUT PERHAPS THE EXTREME
SOUTHEAST PART OF THE FORECAST AREA BY SUNRISE...WITH A FEW LIGHTER
SNOW SHOWERS ALSO ACROSS FAR NORTHEAST IL BENEATH PATH OF MID-LEVEL
VORT DURING THAT TIME. RELATIVELY DRY ARCTIC AIR SPREADING IN FROM
THE NORTHWEST WILL ALLOW SOME SCATTERING OF CLOUD COVER AND AN END
TO ACCUMULATING SNOW SHOWERS BY SUNRISE...THOUGH ONE MORE SHORT WAVE
DROPPING SOUTHEAST ACROSS MINNESOTA AT 08Z MAY BE ENOUGH TO PRODUCE
SOME ENHANCED STRATOCU AND A FEW FLURRIES ACROSS THE REGION DURING
THE MID/LATE MORNING HOURS. IN THE WAKE OF THE PASSAGE OF THIS
MID-LEVEL VORT AXIS AROUND MIDDAY...RISING HEIGHTS AND SUBSIDENCE
SHOULD RESULT IN AN END TO FLURRIES AND THINNING/EROSION OF THE
STRATOCU DECK ALLOWING PARTLY CLOUDY/MOSTLY SUNNY SKIES THIS
AFTERNOON. BLUSTERY NORTHWEST WINDS WILL KEEP TEMPS WELL BELOW
NORMAL ONCE AGAIN...WITH UPPER 20S/LOW 30S EXPECTED FOR AFTERNOON
HIGHS PER BIAS CORRECTED MOS BLEND. BROAD UPPER RIDGE BUILDS ACROSS
THE REGION TONIGHT IN THE WAKE OF OUR DEPARTING EASTERN CONUS UPPER
TROUGH WITH SURFACE HIGH PRESSURE RIDGE BUILDING INTO THE REGION
OVERNIGHT. THIS MORNINGS LIGHT SNOWFALL WILL BE GONE BY
TONIGHT...THOUGH LIGHT WINDS AND CLEAR SKIES WILL ALLOW FOR COOLING
INTO THE TEENS IN MOST AREAS BY WEDNESDAY MORNING.
SURFACE HIGH PRESSURE MOVES QUICKLY EAST OF THE FORECAST AREA
WEDNESDAY AS SURFACE PRESSURE FALLS DEVELOP ACROSS THE PLAINS AND
MISSISSIPPI VALLEY IN RESPONSE TO SURFACE LOW DEVELOPING OVER THE
DAKOTAS IN ADVANCE OF AN UPPER TROUGH OVER THE WESTERN CONUS AND
UPPER JET MAX SPREADING ACROSS THE CENTRAL AND SOUTHERN ROCKIES.
THIS RESULTS IN FAIRLY QUICK WARM ADVECTION AND MOISTURE TRANSPORT
INTO THE REGION ESPECIALLY ABOVE THE BOUNDARY LAYER AS 40-50 KT
SOUTH-SOUTHWESTERLY LOW LEVEL JET DEVELOPS BY LATE AFTERNOON.
INCREASING MID-LEVEL CLOUD COVER WILL LIKELY OFFSET SOME OF THE
WARMING AS WILL A SLIGHT SOUTHEAST COMPONENT TO THE BOUNDARY LAYER
WIND. EVEN SO...FAVOR WARMER MAV GUIDANCE OF WEDNESDAY AFTERNOON MAX
TEMPS IN THE UPPER 30S/LOWER 40S. EXCEPTION WILL BE ALONG THE
IMMEDIATE NORTH SHORE AREA...WHERE THAT SLIGHT SOUTHEAST WIND
COMPONENT MAY HOLD TEMPS IN THE MID 30S RIGHT ALONG THE LAKE. DEEPER
MOISTURE CONTINUES TO SPREAD INTO THE REGION WEDNESDAY NIGHT...AS
SURFACE LOW MOVES INTO THE UPPER MISSISSIPPI VALLEY AND A SHORT WAVE
TROUGH PROPAGATES FROM THE SOUTH CENTRAL PLAINS INTO THE WESTERN
GREAT LAKES. FORECAST SOUNDINGS DEPICT DEEP SATURATION OCCURRING
MAINLY AFTER MIDNIGHT...WITH SUFFICIENT FORCING APPROACHING SHORT
WAVE AND ISENTROPIC ASCENT/JET DIVERGENCE TO GO WITH LIKELY POPS.
THERMAL PROFILES BECOME NEARLY ISOTHERMAL NEAR 0C IN THE LOWER
LEVELS INITIALLY BEFORE WARM ADVECTION OVERWHELMS THE
COLUMN...SUGGESTING THE POTENTIAL FOR S BRIEF MIX OF RAIN/SNOW WITH
THE ONSET OF PRECIP...BUT QUICKLY TURNING TO RAIN AS 50-60 KT LOW
LEVEL JET CONTINUES TO PUMP IN WARM/MOIST AIR. TIGHT SFC PRESSURE
GRADIENT WILL MAINTAIN BREEZY SOUTH WINDS OVERNIGHT AS WELL...WHICH
WILL LIKELY KEEP TEMPS ABOVE FREEZING OVERNIGHT AND PROBABLY RISING
BEFORE SUNRISE. INITIAL SHORT WAVE LIFTS ACROSS THE AREA THURSDAY
MORNING...WITH AN AREA OF MODESTLY STEEP MID-LEVEL LAPSE RATES NOTED
ACROSS CENTRAL IL AND SOUTHERN CWA. HAVE INDICATED ISOLATED THUNDER
FAR SOUTH DURING THE MORNING PERIOD WITH THESE BETTER ELEVATED LAPSE
RATES BEFORE SOME MID-LEVEL DRYING OCCURS BEHIND THE INITIAL SHORT
WAVE. SHOWER CHANCES REMAIN RELATIVELY HIGH THROUGH THE DAY THURSDAY
IN MOIST WARM SECTOR...WITH GFS PRECIPITABLE WATER NEAR 0.9
INCHES...AND APPROACH OF SECOND SHORT WAVE/MAIN TROUGH AXIS LATER IN
THE DAY ALONG WITH APPROACH OF SURFACE COLD FRONT THURSDAY EVENING.
ECMWF REMAINS A LITTLE SLOWER WITH THE PASSAGE OF THE LOW/COLD FRONT
THURSDAY NIGHT...SO HAVE MAINTAINED POPS INTO THE NIGHT WITH A LOW
CHANCE LINGERING IN THE FAR EAST INTO EARLY FRIDAY. MILD/MOIST AIR
MASS SHOULD PUSH TEMPS UP AROUND 50 THURSDAY DESPITE CLOUDS/PRECIP.
COOLER AIR WORKS IN FRIDAY WITH WEAK HIGH PRESSURE RIDGE BEHIND
DEPARTING SYSTEM...WITH WINDS LIKELY TURNING NORTHEAST OFF THE LAKE
FRIDAY AFTERNOON KEEPING LAKESIDE LOCATIONS CHILLY AROUND 40 DEG.
GUIDANCE IN GOOD AGREEMENT IN BRINGING ANOTHER PROGRESSIVE AMPLIFIED
SHORT WAVE ACROSS THE AREA FRIDAY NIGHT/SATURDAY...WITH AN AREA OF
SURFACE LOW PRESSURE PASSING SOUTH OF THE CWA. MOST OF THE PRECIP
REMAINS SOUTH/SOUTHEAST OF THE FORECAST AREA WITH THIS FEATURE...
THOUGH HAVE INCLUDED LOW CHANCE POPS MAINLY FRIDAY NIGHT. PRECIP
TYPE COULD BE A QUESTION ESPECIALLY SOUTH WHERE IT COULD BE A
RAIN/SNOW MIX PER THICKNESS PROGS AND THERMAL PROFILES. NORTHEAST
WINDS AROUND THE NORTHERN PERIPHERY OF THE PASSING LOW WILL CONTINUE
TO HOLD TEMPS BELOW NORMAL...ESPECIALLY NEAR LAKE MICHIGAN. MODELS
CONTINUE TO DEVELOP ANOTHER DEEP LOW ACROSS THE NORTHERN PLAINS
SUNDAY/MONDAY...WITH STRONG SOUTH FLOW DEVELOPING AND OFFERING THE
PROSPECT OF WARMER WEATHER BY THE END OF THE FORECAST PERIOD.
BLENDED GUIDANCE INDICATES 55-60+ DEGREES SUNDAY AND MONDAY...THOUGH
WITH BREEZY CONDITIONS AND AN INCREASING POTENTIAL FOR RAIN MONDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* BRIEF BURST OF MODERATE TO POTENTIALLY VERY HEAVY SNOW AND WNW
GUSTS APPROACHING 30 KT. ARRIVING AT ORD 0630Z AND MDW 0700Z.
* GUSTY NORTHWEST WINDS RESUME THIS MORNING AND CONTINUE THROUGH
AFTERNOON.
RC
//DISCUSSION...UPDATED 06Z...
HAVE MOVED UP THE TIMING IN TAFS OF NARROW AND INTENSE LINE OF SN
ON LEADING EDGE OF SHARP COLD FRONT. IT IS SET TO ARRIVE AT DPA
SHORTLY AFTER 6Z...AROUND 630Z AT ORD...7Z AT MDW AND 730Z AT GYY.
WHEN LINE MOVED THROUGH RFD...THERE WAS ABOUT A 5-10 MINUTE PERIOD
OF 1/4 SM +SN ACCOMPANIED BY WNW GUSTS CLOSE TO 30 KT. WITH LINE
REMAINING WELL ORGANIZED WOULD EXPECT SIMILAR CONDITIONS AT THE
EASTERN TERMINALS. CONDITIONS WILL IMPROVE RAPIDLY 20-30 MIN AFTER
SNOW ONSET...THOUGH WILL NEED TO WATCH FOR A FEW SCT SHSN BEHIND
THE FRONT. WINDS WILL DIMINISH FOR A TIME OVERNIGHT BUT THEN RAMP
UP OUT OF THE NORTHWEST BY OR A FEW HOURS AFTER DAYBREAK.
EXPECTING GUSTS IN THE 25 TO 30 KT RANGE. FORECAST SOUNDINGS
SUPPORT BKN VFR CIG AROUND 4KFT THOUGH THERE COULD BE PERIODS OF
JUST SCT CLOUDS. SKIES WILL CLEAR AND WINDS WILL QUICKLY DIMINISH
AS HIGH PRESSURE MOVES OVERHEAD TUESDAY EVENING.
RC
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH IN BRIEF PERIOD OF MODERATE TO VERY HEAVY SNOW AND STRONG
WEST NORTHWEST WINDS.
* MEDIUM-HIGH IN CIG TRENDS TODAY.
* HIGH IN REMAINING ELEMENTS.
RC
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR.
THURSDAY...OCNL RA. IFR POSSIBLE.
FRIDAY...MVFR POSSIBLE EARLY...LIKELY TRENDING VFR.
SATURDAY AND SUNDAY...VFR.
IZZI
&&
.MARINE...
354 AM CDT
A FEW ACTIVE PERIODS COMING UP ON THE LAKE THROUGH THE END OF THE
WORK WEEK. NORTHWEST WINDS GUSTING TO 30 KT THROUGH LATE AFTERNOON
ON THE SOUTH HALF TODAY AND SMALL CRAFT CRITERIA WINDS...WITH WAVES
SUBSIDING DURING THE EVENING.
HIGH PRESSURE MOVING OVER THE LAKE TONIGHT THROUGH EARLY WEDNESDAY
WILL RESULT IN A BRIEF QUIET PERIOD. AS THE HIGH PRESSURE SLIDES
EAST ON WEDNESDAY...STRONG LOW PRESSURE WILL TAKE SHAPE ACROSS THE
CENTRAL PLAINS AND MOVE EAST. THIS WILL RESULT IN RAPIDLY INCREASING
SOUTHERLY WINDS LATE DAY WEDNESDAY THROUGH WEDNESDAY NIGHT. THE AIR
MASS WILL BE WARMING BUT STILL LOOKS TO BE MARGINALLY UNSTABLE
ENOUGH FOR A PERIOD OF GALES ON THE SOUTHERN AND CENTRAL PORTION OF
THE LAKE. HAVE NOT ISSUED A WATCH DUE TO LIMITED DURATION AND LOWER
CONFIDENCE IN PREVAILING OCCURRENCE OF GALES.
STRONG SOUTH-SOUTHWEST WINDS WILL CONTINUE THROUGH THURSDAY EVENING
AS THE LOW DRAWS NEARER. STABLE CONDITIONS WILL LIMIT
MIXING...THOUGH WINDS JUST ABOVE THE BOUNDARY LAYER COULD APPROACH
40 KT. SOME GUIDANCE CONTINUES TO KEEP MIXING ONGOING PART OF
THURSDAY ON THE NORTH HALF OF THE LAKE. HAVE OPTED TO CAP SPEEDS
BELOW GALES ON THURSDAY ACROSS THE LAKE DUE TO UNCERTAINTY WITH
MIXING. AFTER THE LOW CROSSES THE LAKE THURSDAY NIGHT...THE
TRAILING COLD FRONT WILL SWEEP ACROSS THE LAKE...WITH WINDS
SHIFTING NORTHWEST TO 25 TO 30 KT INTO FRIDAY BEFORE BACKING
NORTHERLY AND GRADUALLY DIMINISHING IN THE AFTERNOON. ANOTHER LOW
WILL TRACK ACROSS THE OHIO VALLEY EARLY SATURDAY AND IF IT GETS
CLOSE ENOUGH TO LAKE...NORTHEAST WINDS ON SOUTH HALF COULD BE
STRONGER THAN INDICATED. WINDS WILL TURN SOUTHERLY AND INCREASE ON
SUNDAY THROUGH SUNDAY NIGHT IN ADVANCE OF ANOTHER STRONG LOW
PRESSURE AREA THAT WILL MOVE ACROSS THE REGION ON MONDAY.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 PM TUESDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
National Weather Service Lincoln IL
253 AM CDT Tue Mar 25 2014
.DISCUSSION...
ISSUED 253 AM CDT Tue Mar 25 2014
SHORT TERM...Today through Thursday
07z/2am radar imagery shows two bands of snow across central
Illinois...one along the I-55 corridor and one further west in the
Illinois River Valley. Based on radar timing tools and 05z HRRR,
snow will be east of I-57 by 12z, then will quickly exit into
Indiana by mid-morning. Will therefore hold on to low chance POPs
across the far E/SE KILX CWA through 15z, followed by dry
conditions across the board through the balance of the day. Sky
cover forecast will be a bit tricky today, as clearing immediately
behind the snow bands may be muddled by SCT-BKN clouds currently
upstream over Minnesota/northern Iowa. HRRR hints that this cloud
cover will filter southward into the area, resulting in a partly
sunny day. Main story will be the breezy and unseasonably cold
conditions. With temperatures hovering in the 30s and strong
northwesterly winds gusting to between 20 and 30mph, wind-chill
values will remain in the teens.
Clouds will clear out toward sunset as high pressure builds in
from the west. Thanks to clear skies and decreasing winds beneath
the ridge axis, a very cold night is in store with lows dipping
into the teens. High will quickly shift off to the east on
Wednesday allowing a warming trend to begin. Despite full
sunshine, will undercut numeric guidance by a couple of degrees
due to southeasterly component of return flow on back side of
departing high. Resulting high temperatures will remain in the
lower to middle 40s.
Models continue to markedly increase WAA Wednesday night, with all
solutions bringing rain showers into the area overnight. Think
this looks reasonable given strengthening low-level southerly flow
and moistening forecast soundings. In addition, precip coverage
will be enhanced by a lead short-wave ejecting northeastward out
of the Southern Plains. Have therefore bumped POPs to likely after
midnight. Thursday appears to be a windy and wet day, with
numeric guidance suggesting southerly winds gusting to around 30
mph. This will push highs well into the 50s. Increasing elevated
instability could lead to a few rumbles of thunder as well,
particularly as initial short-wave passes through the area. Main
convective event still looks likely for Thursday evening as cold
front pushes into central Illinois. Will continue with likely POPs
for showers and thunderstorms at that time.
LONG TERM...Friday through Monday
00z Mar 25 models are now in good agreement with timing of
departing front late Thursday night, resulting in a cooler and
drier day on Friday. Given model consensus, have removed shower
chances on Friday except across the far E during the morning.
Despite FROPA, a new fly-in-the-ointment has developed for the end
of the week. Both the GFS and ECMWF now develop a secondary
surface low along the trailing end of the front Friday night.
ECMWF had previously shown this feature on a few prior runs, but
never with any consistency. GFS on the other hand had always
advertised a clean FROPA with no secondary wave. GEM also shows
this wave, so given consensus among the three models, confidence
is growing that light precip may return to part of the area Friday
night. At this point, will focus low chance POPs across only the
southern CWA along/south of I-70 in closer proximity to the low
with dry conditions further north across the remainder of the
area. After that, upper heights rise considerably as ridge builds
across the central CONUS. As a result, temperatures will rise back
above normal, with readings climbing well into the 60s for Sunday
and Monday.
Barnes
&&
.AVIATION...
ISSUED 1154 PM CDT Mon Mar 24 2014
An initial band of light snow will reach PIA by 05z/midnight, then
progress eastward to CMI by 09z. A secondary band of snow about 1
to 2 hours behind the first band will produce snowfall rates of 1
inch per hour as it moves across the northern portions of C IL. The
dry air near the ground will limit snowfall amounts a bit. Most
areas will likely see up to a half inch on grassy areas with some
melting on the warmer road surfaces. The TAF sites will see MVFR
clouds and VIS at the onset of snow with potential for some IFR
vis and ceilings between the first and second band of snow. Tempos
were used to cover the potential for LIFR vis in heavier snows for
1/2sm sn for an hour or so at each site between 07z and 12z from
west to east. Snow should diminish quickly Tues morning as the
trough departs to the east and subsident motions become dominant.
A layer of VFR clouds are expected to redevelop before noon even
after snow comes to an end and linger into early evening before
clearing.
Winds will generally remain less than 10kt the rest of tonight,
with a variable wind direction until the W-NW winds increase later
tonight. By mid-morning on Tuesday, NW wind speeds will climb to
around 15G30kt as cold air advection intensifies. Those wind
speeds will likely linger until later afternoon before diminishing
to less than 10kt Tues evening.
Shimon
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1051 PM MDT MON MAR 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 230 PM MDT MON MAR 24 2014
AS OF 2 P.M. MDT...VISIBLE SATELLITE IMAGERY INDICATED A DENSELY
POPULATED CUMULUS FIELD ACROSS THE TRI STATE AREA...WITH PARTLY TO
MOSTLY CLOUDY SKIES. NO SIGNIFICANT RADAR RETURNS WERE OBSERVED AS
DRY CONDITIONS WERE PRESENT ACROSS THE REGION.
UPPER LEVEL LONG WAVE TROUGH MOVES EASTWARD OUT OF THE CENTRAL
PLAINS AS STRONGER AREA OF THE JET MOVES DOWN THE HIGH PLAINS THIS
EVENING AND OVERNIGHT. HIGHER VORTICITY POCKET WILL HELP CREATE LIFT
TO GENERATE INCREASED CLOUD COVER FOR AREAS EAST OF HIGHWAY 83
TONIGHT. UPPER LEVEL TROUGH WILL MOVE INTO THE TRI STATE AREA FROM
THE WEST TO BRING CLEARING SKIES TO AREAS WEST OF HIGHWAY 83
OVERNIGHT.
LOW TEMPERATURES TONIGHT WILL STAY A BIT WARMER FOR AREAS EAST OF
HIGHWAY 83 WITH THE INCREASED CLOUD COVER...BUT TEMPERATURES WILL
REACH THE UPPER TEENS WITH THE AREAS OF CLEARING CLOUD COVER.
TEMPERATURES WILL DROP TO NEAR THE DEW POINTS WITH RELATIVE
HUMIDITIES AT THE SURFACE APPROACHING ONE HUNDRED PERCENT...WHICH
COULD CREATE SOME AREAS OF PATCHY FOG IN EASTERN COLORADO AND AREAS
WEST OF KANSAS HIGHWAY 27. RAP MODEL SOUNDINGS SHOW TEMPERATURES
WARMING IN THE MID MORNING...WHICH WILL BRING RAPID CLOUD CLEARING
WITH INCREASED SUBSIDENCE FROM THE SURFACE HIGH PRESSURE THAT MOVES
INTO THE HIGH PLAINS. AS SURFACE HIGH MOVES EASTWARD
TOMORROW...SOUTHERLY FLOW AND INCREASED WARM AIR ADVECTION WILL
ALLOW HIGH TEMPERATURES TO REACH THE LOW TO MID 50S. THE WARMEST
TEMPERATURES WILL BE ALONG THE KANSAS AND COLORADO STATE BOUNDARY AS
WARM FRONT WITH ASSOCIATED CYCLOGENESIS WILL BRING THE HIGHEST
TEMPERATURES. PROBABILITY FOR PRECIPITATION IS NEXT TO NONE TONIGHT
AND TOMORROW.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 251 PM MDT MON MAR 24 2014
TUESDAY NIGHT-THURSDAY...SHORT WAVE RIDGING EXPECTED TO BE DOMINANT
FORCING MECHANISM ACROSS THE FORECAST AREA DURING THE START OF THE
PERIOD...ALTHOUGH MORE ACTIVE WEATHER WILL DEVELOP ACROSS THE AREA
AS A SERIES OF PROGRESSIVE SHORT WAVE TROUGHS BEGINS TO INFLUENCE
THE AREA ON WEDNESDAY. INITIAL WEATHER CONCERNS WILL CENTER AROUND
POSITION OF WEAK DRY LINE EXPECTED TO BISECT THE AREA ON WEDNESDAY
AFTERNOON. TEMPERATURES WILL CLIMB INTO THE LOWER 70S TO THE WEST OF
IT...WITH AFTERNOON HUMIDITIES FALLING TO THE 15 PERCENT. THE
COMBINATION OF WARM TEMPS...DRY FUELS AND WESTERLY WINDS OF 15 TO 25
MPH WILL BRING THE POTENTIAL FOR CRITICAL FIRE WEATHER CONDITIONS.
WILL NEED TO WATCH FOR POTENTIAL WATCH OR WARNING AS THIS TIME
NEARS...BUT CURRENTLY IS A BIT TOO FAR OUT IN TIME TO WARRANT A
WATCH AT THIS POINT. TO THE EAST OF THE DRY LINE...STRONG SOUTHERLY
WINDS WILL NEAR ADVISORY LEVELS AS A NARROW AREA OF INSTABILITY
DEVELOPS ALONG IT. WILL LIKELY SEE A WEAK STORM OR TWO DEVELOP IN
THIS AREA...BUT WITH LIMITED INSTABILITY DO NOT EXPECT STRONG OR
WIDESPREAD STORMS ATTM. SHORT WAVE TROUGH...AS PER 1.5 PVU PRESSURE
ANOMALY...WILL BEGIN TO MOVE ACROSS THE AREA WEDNESDAY EVENING
BRINGING A PERIOD OF FORCED ASCENT...MAINLY TO THE NORTHERN CWA.
MODELS REALLY DIVERGE ON HOW THIS SYSTEM EVOLVES...RANGING FROM ONE
STRONG PERIOD OF FORCING TO SEVERAL INDIVIDUAL WAVES LINGERING
THROUGH THURSDAY. WITH LARGE DIFFERENCES BETWEEN OPERATIONAL MODELS
AND ENSEMBLE DATA FURTHER RAISING UNCERTAINTY...AM GOING TO KEEP
GENERAL FORECAST INTACT AND LIMIT POPS TO THE 30 TO 50 PERCENT RANGE.
IN THE EXTENDED (THURSDAY NIGHT-MONDAY)...WARMER AND DRIER WEATHER
WILL DEVELOP ACROSS THE AREA AS BROAD RIDGING BUILDS OVER THE AREA.
EXPECT TEMPERATURES TO WARM INTO THE UPPER 70S BY SUNDAY. ALTHOUGH
STANDARD DEVIATIONS OF THE ENSEMBLES REMAIN QUITE HIGH DURING THE
PERIOD...OVERALL MODEL AGREEMENT ON THE OVERALL PATTERN LEADS ME TO
LEAN TOWARDS WARMER SOLUTIONS. OVERALL QUIET WEATHER IS EXPECTED
ALTHOUGH FIRE DANGER WILL INCREASE AS THE TEMPS RISE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1048 PM MDT MON MAR 24 2014
VFR CONDITIONS FORECAST AT KGLD/KMCK THROUGH THE TAF PERIOD.
A BROKEN TO OVERCAST DECK OF MID CLOUDS WITH BASES FL060-100 WILL
PERSIST OVERNIGHT AT KMCK CONTINUING THRU 15Z TUESDAY. KGLD WILL
BE ON THE WESTERN FRINGE OF THIS DECK WITH BEST CIG POTENTIAL 08Z-
13Z. THIS CLOUD DECK WILL SLIDE OFF TO THE EAST TUESDAY MORNING.
SURFACE HIGH PRESSURE WILL MOVE FROM MONTANA INTO SOUTHERN
NEBRASKA BY 15Z TUESDAY. SURFACE WINDS WILL BE LIGHT- VARIABLE
OVERNIGHT...GRADUALLY BECOMING S-SE TUESDAY MORNING WITH SPEEDS
INCREASING TO 12-15 KTS BY AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...MK
LONG TERM...JRM
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1147 PM CDT Mon Mar 24 2014
.UPDATE...
Issued at 919 PM CDT MON MAR 24 2014
Followed the HRRR and RUC13 and 18Z NAM, along with observational
trends for general PoP trends through Tuesday morning. A narrow
east-west oriented band of light snow extending from Farmington
Missouri to Evansville Indiana will gradually dry up from west to
east late this evening, as it drifts slowly southward.
Temperatures will drop close to freezing once this snow sets in,
so some minor accumulations will be possible in this area late
this evening. Other light precipitation may dive southeast through
western portions of southeast Missouri and possibly into the
Purchase Area of west Kentucky through the late evening. This
should mainly be rain, and temperatures will likely hold in the
middle 30s.
There should be a break for a few hours after midnight, before
another impulse rotates through the area with a band of light snow
or snow showers. More minor accumulations will be possible over
southern Illinois generally north of Highway 13, southwest
Indiana and northwest Kentucky. This will likely straddle sunrise
and may be ongoing during the morning commute over the Evansville
Tri State. Will have to monitor for slick conditions in the
morning...but confidence is low to think about an Advisory at this
time. All totalled, grassy accumulations will generally be a half
inch or less, with the greatest amounts over southwest Indiana.
The RUC has a real good handle on surface temperatures, as they
drop to near freezing once the precipitation develops in a given
area. Used it as a guide for trends through the night, but
ultimately, low temperatures were not impacted much by morning.
&&
.SHORT TERM...(Tonight through Wednesday)
Issued at 247 PM CDT MON MAR 24 2014
Main challenge this package is the threat for rain/snow mainly
tonight over the northern half.
Water vapor and radar indicate a weak system in the flow currently
over Kansas. All models continue to weaken the system as it moves
closer to us. We are very dry in the low levels so it may take a
while for the precipitation to reach the ground. It should
saturate over the north central areas by early evening. May be a
mix of rain/snow initially, but the column will be cold enough to
generate some snow for a few hours overnight.
Ground is warm and it does not look like we will exceed 1 inch per
hour rates, so feel that any accumulations will be confined to grassy
surfaces. Total QPF is less than a tenth of an inch and snowfall
is expected to be less than 1/2 inch.
This system will exit the area tomorrow morning, maybe with a few
lingering flurries in the northeast in the morning. After that,
high pressure will move into the area and we will remain dry
through Wednesday.
Will strongly word fire weather forecast for tomorrow as winds
will be strong and afternoon RH values will range from 30-40
percent.
Tuesday night will be coldest night of the week with lows in the
teens near I-64 and mid 20s in the south.
.LONG TERM...(Thursday through Monday)
Issued at 247 PM CDT MON MAR 24 2014
The med range models/ensembles seem in decent agreement with the
over synoptic pattern through Friday. Thereafter...12Z GFS diverges
from the operational ECMWF/GEM runs with respect to sfc low/precip
generation over the OH Valley. The GFS seems like an outlier here,
so will not give it too much weight at this time.
As far as the sensible weather is concerned, though shower chcs will
begin to slowly increase late Wed night in prefrontal warming
environment, the highest chc for showers and even some elevated
thunderstorms will come with the frontal passage Thu night. Some
locations may end up with a half inch or more. Decided to go with
a mainly rain free forecast once the front exits the area Friday
as high pressure presses southeast into the Midwest. Again, will
discount the 12Z GFS for now in the Fri/Fri night time frame. Will
also stick closer to the cooler EC MOS numbers Friday. Confidence
increases once again as we move into the weekend. There seems to
be very good model agreement that a dry and warming pattern should
get underway in the last few days of the extended period.
&&
.AVIATION...
Issued at 1146 PM CDT MON MAR 24 2014
Had to speed up the onset of snow across the TAF sites this
evening. With the exception of KPAH, kept all TAF`s in VFR ceiling
category, before clearing late Tuesday afternoon and evening.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...PS
LONG TERM...GM
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
523 AM EDT TUE MAR 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM EDT TUE MAR 25 2014
LATEST 08Z WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL
RIDGE OVER WRN NOAM AND A TROUGH FROM HUDSON BAY THROUGH MUCH OF THE
ERN CONUS. A SHORTWAVE ROTATING INTO WRN LAKE SUPERIOR PUSHED AN
ARCTIC COLD FRONT THROUGH WRN UPR MI EARLY THIS MORNING. NW OF LAKE
SUPERIOR IN THE WAKE OF THE FRONT...TEMPS ARE GENERALLY AT OR BELOW
ZERO. THIS COLDER AIR MOVING ACROSS LAKE SUPERIOR HAS GENERATED SOME
SCT -SHSN DOWNWIND OF THE LAKE IN A NW FLOW.
TODAY...AS THE SFC HIGH PRESSURE RIDGE AND ASSOC SUBSIDENCE BUILD
INTO THE WRN LAKES LATE THIS MORNING INTO THE AFTERNOON...SOUNDINGS
DRY FM 850-700 MB AND WINDS BACK WRLY...EXPECT LAKE SHSN TO DIMINISH
WITH ACCUMULATIONS GENERALLY AN INCH OR LESS. WITH 925/850 MB TEMPS
ONLY TO AROUND -18/-23C...TEMPS MAY STRUGGLE TO REACH THE LOWER TO
MID TEENS ALONG LAKE SUPERIOR...MORE THAN 20 DEGREES BELOW SEASONAL
AVERAGES.
TONIGHT...A HIGH PRESSURE RIDGE MOVING OVER THE UPPER GREAT LAKES
REGION WILL LEAD TO ANOTHER VERY COLD NIGHT TONIGHT ACROSS THE AREA.
WITH WINDS BACKING WSW WOULD NOT THINK LINGERING LAKE CLOUDS SHOULD
NOT BE A FCST CONCERN. THUS...WOULD EXPECT CLEARING SKIES AND IDEAL
RADIATIONAL COOLING CONDITIONS UNDER LIGHT WINDS. SINCE PWAT VALUES
ARE EXPECTED AROUND 30 PERCENT OF NORMAL...CONTINUED TO FCST MIN
TEMPS BLO GUIDANCE...ESPECIALLY IN THE TRADITIONAL INTERIOR COLD
SPOTS. LOOK FOR LOWS BELOW ZERO OVER PRETTY MUCH ALL OF THE U.P. AND
IN THE TEENS BELOW ZERO OVER THE INTERIOR. BASED OFF THE TRENDS IN
THE LONGER RANGE MODELS...THIS WILL LIKELY BE THE LAST REALLY COLD
NIGHT ACROSS THE REGION THIS SEASON.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 522 AM EDT TUE MAR 25 2014
S WINDS OF WEDNESDAY WILL HELP RAISE TEMPS ABOUT 10F HIGHER THAN
WHAT WILL BE EXPERIENCED TODAY ACROSS THE CWA...ESPECIALLY W AND N.
THIS WILL BE DESPITE SNOW NEARING FROM THE NW. KEPT A SLIGHT CHANCE
FAR W BY LATE AFTERNOON...ALTHOUGH THE TREND IS TO SLOW DOWN THE
POPS EVEN MORE.
ANOTHER DAY CLOSER TO OUR WEDNESDAY NIGHT THROUGH THURSDAY EVENING
EVENT. WHILE FCST SOLUTIONS HAVE COME A BIT MORE IN LINE...THEY
COULD BE BETTER. EXPECT SIGNIFICANT IMPROVEMENTS AT THE DISTURBANCE
MOVES FROM THE PACIFIC OVER THE BETTER SAMPLED/MODELED CONTINENTAL
U.S. WILL CONTINUE TO MINIMIZE THE USE OF THE NAM PAST 18Z THURSDAY
AS IT STILL IS AN OUTLIER WITH REGARDS TO THE STRENGTHENING OF THE N
EXTENT OF THE LOW AND IS QUICKEST TO SHIFT IT TO E QUEBEC THURSDAY
EVENING. WHILE THE 18Z GFS LINED UP BETTER WITH THE NEW 00Z RUN OF
THE ECMWF...THE 00Z GFS CONTINUED WITH THE QUICKER SOLUTION AGAIN.
THE CONSENSUS IS TO HAVE THE LOW SITUATED OVER THE CENTRAL PLAINS AT
06Z THURSDAY...WITH THE INVERTED TROUGH STRETCHING UP THROUGH N MN
AND W LAKE SUPERIOR. THE WEAKENING LOW WILL THEN MOVE ACROSS IA AND
S WI BY 00Z FRIDAY...BEFORE CROSSING LOWER MI OVERNIGHT. AS NOTED
ABOVE THE GFS HITS THE GAS ON THIS ONE...MOVING E OF LAKE HURON BY
12Z FRIDAY...WHILE THE ECMWF IS OVER S LOWER MI AND CENTRAL LAKE
HURON.
WHILE EXPECTED TO BE ALL SNOW THROUGH 12Z THURSDAY...THE POTENTIAL
EXISTS FOR SOME MIXING IN OF RAIN OR SLEET ALONG THE WI BORDER. THE
FOCUS FOR HEAVY WET SNOW WILL BE OVER THE TIP OF THE KEWEENAW
PENINSULA WEDNESDAY NIGHT.
TEMPS WERE RAISED SLIGHTLY FOR THURSDAY MORNING /STILL IN THE 20S/.
THEY SHOULD QUICKLY RISE ABOVE 32F AFTER 12Z...DIMINISHING THE NEED
FOR FREEZING RAIN IN THE FCST. AS A RESULT...IT LOOKS TO BE A MAINLY
RAIN OR SNOW EVENT. WILL KEEP THE MENTION OF MODERATE WET SNOW...AND
MIXED PRECIP IN THE HWO. CONTINUE TO EXPECT THE MOST SNOW N AS WARM
AIR SURGES IN FROM THE S. RAIN MAY RUN ACROSS MUCH OF THE
CWA...EXCLUDING THE KEWEENAW PENINSULA WITH THE BEST CHANCE
STRETCHING FROM WATERSMEET TO ESC AND ISQ FROM 15-21Z THURSDAY. FOR
THURSDAY THROUGH THURSDAY NIGHT 3-6IN OF SNOW WILL BE POSSIBLE
ACROSS MUCH OF THE CWA...WITH MORE LIKE 2-3IN ACROSS MENOMINEE
COUNTY.
ANOTHER CONUNDRUM IS WHEN TO DIMINISH POPS. YES COLD AIR WILL BE
RUSHING IN BEHIND THE EXITING LOW THURSDAY NIGHT...BUT THE ECMWF
ONLY HAS TEMPS FALLING TO AROUND -9C BY 12Z FRIDAY ON FAVORABLE N
WINDS. WITH THE MAIN SHORTWAVE EXITING E UPPER MI AT THAT TIME AND
ZONAL FLOW ALOFT...THE COLDEST AIR WILL REMAIN ACROSS ONTARIO. DRY
HIGH PRESSURE OVER S CANADA AND THE N PLAINS WILL SLOWLY EDGE IN FOR
LATE FRIDAY AFTERNOON THROUGH THE DAY SATURDAY...WITH LITTLE TO NO
SNOW ANTICIPATED.
AN ELONGATED TROUGH EXTENDING FROM THE MAIN SFC-500MB LOW OVER
HUDSON BAY SUNDAY WILL SHIFT ACROSS UPPER MI...BRINGING THE NEXT
CHANCE RAIN AND SNOW TO THE CWA...BUT NOT BEFORE TEMPS BRIEFLY WARM
INTO THE 40S SUNDAY AFTERNOON.
INCREASED POPS FOR DAY 6/MONDAY AS THE NEXT SFC LOW TRACKS FROM THE
N AND CENTRAL PLAINS SUNDAY AFTERNOON TO THE UPPER GREAT LAKES BY
12Z MONDAY. COMPARING THE 00Z RUNS...THE GFS HAS THE 996MB LOW NEAR
IWD...WHILE THE ECMWF CENTERS THE LOW ACROSS IA. WITH EITHER
SOLUTION...THE BEST CHANCE OF PRECIP LOOKS TO BE W UPPER MI. HAVE
ADDED LIKELY POPS FOR THE KEWEENAW PENINSULA FOR THE DAY MONDAY. AS
FOR SPECIFICS...WE WILL NEED TO WAIT. THE N SOLUTION WOULD BRING
MAINLY RAIN TO THE CWA...WHILE THE ECMWF WOULD RESULT IN MOSTLY
SNOW. WILL KEEP A MIX IN FOR NOW WITH THE BEST CHANCE OF SNOW NW
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 119 AM EDT TUE MAR 25 2014
WITH THE PASSAGE OF A DISTURBANCE OVERNIGHT...SCT -SHSN WILL LIKELY
DEVELOP AT THE TAF SITES. BY LATE TONIGHT INTO TUE MORNING...THE
COMBINATION OF LOW LEVEL CONV AND UPSLOPE FLOW WILL BE ENOUGH TO
SUPPORT HIGH MVFR CIGS OR LOW VFR CIGS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 455 AM EDT TUE MAR 25 2014
EXPECT NW WINDS 20 TO 30 KTS TODAY IN THE WAKE OF AN ARCTIC COLD
FRONT...WITH THE HIGHEST GUSTS OVER THE EASTERN HALF OF LAKE
SUPERIOR. WINDS WILL QUICKLY DIMINISH TONIGHT AND WEDNESDAY AS
ANOTHER HIGH PRESSURE RIDGE MOVES OVER THE AREA. A LOW PRESSURE
SYSTEM DEVELOPING IN THE CENTRAL PLAINS ON WEDNESDAY NIGHT AND
THURSDAY WILL MOVE THROUGH THE GREAT LAKES REGION LATE THURSDAY
NIGHT AND FRIDAY. EXPECT NRLY WINDS 20 TO 30 KTS ON THE BACK SIDE OF
THE LOW THU NIGHT INTO FRI MORNING WITH THE STRONGEST WINDS OVER ERN
LAKE SUPERIOR. WINDS WILL QUICKLY DIMINISH FM THE WEST FRI AFTERNOON
INTO SAT AS HIGH PRESSURE BUILDS OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KF
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
456 AM EDT TUE MAR 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM EDT TUE MAR 25 2014
LATEST 08Z WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL
RIDGE OVER WRN NOAM AND A TROUGH FROM HUDSON BAY THROUGH MUCH OF THE
ERN CONUS. A SHORTWAVE ROTATING INTO WRN LAKE SUPERIOR PUSHED AN
ARCTIC COLD FRONT THROUGH WRN UPR MI EARLY THIS MORNING. NW OF LAKE
SUPERIOR IN THE WAKE OF THE FRONT...TEMPS ARE GENERALLY AT OR BELOW
ZERO. THIS COLDER AIR MOVING ACROSS LAKE SUPERIOR HAS GENERATED SOME
SCT -SHSN DOWNWIND OF THE LAKE IN A NW FLOW.
TODAY...AS THE SFC HIGH PRESSURE RIDGE AND ASSOC SUBSIDENCE BUILD
INTO THE WRN LAKES LATE THIS MORNING INTO THE AFTERNOON...SOUNDINGS
DRY FM 850-700 MB AND WINDS BACK WRLY...EXPECT LAKE SHSN TO DIMINISH
WITH ACCUMULATIONS GENERALLY AN INCH OR LESS. WITH 925/850 MB TEMPS
ONLY TO AROUND -18/-23C...TEMPS MAY STRUGGLE TO REACH THE LOWER TO
MID TEENS ALONG LAKE SUPERIOR...MORE THAN 20 DEGREES BELOW SEASONAL
AVERAGES.
TONIGHT...A HIGH PRESSURE RIDGE MOVING OVER THE UPPER GREAT LAKES
REGION WILL LEAD TO ANOTHER VERY COLD NIGHT TONIGHT ACROSS THE AREA.
WITH WINDS BACKING WSW WOULD NOT THINK LINGERING LAKE CLOUDS SHOULD
NOT BE A FCST CONCERN. THUS...WOULD EXPECT CLEARING SKIES AND IDEAL
RADIATIONAL COOLING CONDITIONS UNDER LIGHT WINDS. SINCE PWAT VALUES
ARE EXPECTED AROUND 30 PERCENT OF NORMAL...CONTINUED TO FCST MIN
TEMPS BLO GUIDANCE...ESPECIALLY IN THE TRADITIONAL INTERIOR COLD
SPOTS. LOOK FOR LOWS BELOW ZERO OVER PRETTY MUCH ALL OF THE U.P. AND
IN THE TEENS BELOW ZERO OVER THE INTERIOR. BASED OFF THE TRENDS IN
THE LONGER RANGE MODELS...THIS WILL LIKELY BE THE LAST REALLY COLD
NIGHT ACROSS THE REGION THIS SEASON.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 450 AM EDT TUE MAR 25 2014
PRELIMINARY THOUGHTS ON LONG TERM FCST.
S WINDS OF WEDNESDAY WILL HELP RAISE TEMPS ABOUT 10F HIGHER THAN
WHAT WILL BE EXPERIENCED TODAY ACROSS THE CWA...ESPECIALLY W AND N.
THIS WILL BE DESPITE SNOW NEARING FROM THE NW. KEPT A SLIGHT CHANCE
FAR W BY LATE AFTERNOON...ALTHOUGH THE TREND IS TO SLOW DOWN THE
POPS EVEN MORE.
ANOTHER DAY CLOSER TO OUR WEDNESDAY NIGHT THROUGH THURSDAY EVENING
EVENT. WHILE FCST SOLUTIONS HAVE COME A BIT MORE IN LINE...THEY
COULD BE BETTER. EXPECT SIGNIFICANT IMPROVEMENTS AT THE DISTURBANCE
MOVES FROM THE PACIFIC OVER THE BETTER SAMPLED/MODELED CONTINENTAL
U.S.
WILL KEEP THE MENTION OF MODERATE WET SNOW...AND MIXED PRECIP IN THE
HWO. CONTINUE TO EXPECT THE MOST SNOW N AS WARM AIR SURGES IN FROM
THE S.
INCREASED POPS FOR DAY 6/MONDAY AS THE NEXT SFC LOW TRACKS FROM THE
N AND CENTRAL PLAINS SUNDAY AFTERNOON TO THE UPPER GREAT LAKES BY
12Z MONDAY. COMPARING THE 00Z RUNS...THE GFS HAS THE 996MB LOW NEAR
IWD...WHILE THE ECMWF CENTERS THE LOW ACROSS IA. WITH EITHER
SOLUTION...THE BEST CHANCE OF PRECIP LOOKS TO BE W UPPER MI. HAVE
ADDED LIKELY POPS FOR THE KEWEENAW PENINSULA FOR THE DAY MONDAY. AS
FOR SPECIFICS...WE WILL NEED TO WAIT. THE N SOLUTION WOULD BRING
MAINLY RAIN TO THE CWA...WHILE THE ECMWF WOULD RESULT IN MOSTLY
SNOW. WILL KEEP A MIX IN FOR NOW WITH THE BEST CHANCE OF SNOW NW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 119 AM EDT TUE MAR 25 2014
WITH THE PASSAGE OF A DISTURBANCE OVERNIGHT...SCT -SHSN WILL LIKELY
DEVELOP AT THE TAF SITES. BY LATE TONIGHT INTO TUE MORNING...THE
COMBINATION OF LOW LEVEL CONV AND UPSLOPE FLOW WILL BE ENOUGH TO
SUPPORT HIGH MVFR CIGS OR LOW VFR CIGS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 455 AM EDT TUE MAR 25 2014
EXPECT NW WINDS 20 TO 30 KTS TODAY IN THE WAKE OF AN ARCTIC COLD
FRONT...WITH THE HIGHEST GUSTS OVER THE EASTERN HALF OF LAKE
SUPERIOR. WINDS WILL QUICKLY DIMINISH TONIGHT AND WEDNESDAY AS
ANOTHER HIGH PRESSURE RIDGE MOVES OVER THE AREA. A LOW PRESSURE
SYSTEM DEVELOPING IN THE CENTRAL PLAINS ON WEDNESDAY NIGHT AND
THURSDAY WILL MOVE THROUGH THE GREAT LAKES REGION LATE THURSDAY
NIGHT AND FRIDAY. EXPECT NRLY WINDS 20 TO 30 KTS ON THE BACK SIDE OF
THE LOW THU NIGHT INTO FRI MORNING WITH THE STRONGEST WINDS OVER ERN
LAKE SUPERIOR. WINDS WILL QUICKLY DIMINISH FM THE WEST FRI AFTERNOON
INTO SAT AS HIGH PRESSURE BUILDS OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KF
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
450 AM EDT TUE MAR 25 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 415 PM EDT MON MAR 24 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE OVER
WRN NOAM AND A TROUGH FROM HUDSON BAY THROUGH MUCH OF THE ERN CONUS.
AN UPSTREAM SHORTWAVE TROUGH AND ASSOCIATED ARCTIC COLD FRONT
EXTENDED FROM NEAR JAMES BAY TO FAR NW MN. TO THE NORTH OF THE FRONT
19Z TEMPS ONLY RANGED FROM 0F TO 5F. AT THE SFC...WRLY LOW LEVEL
FLOW PREVAILED AHEAD OF THE FRONT WITH ONLY SCT-BKN DIURNAL CU/SC
OVER UPPER MICHIGAN.
TONIGHT...AS THE SHORTWAVE TROUGH AND COLD FRONT MOVE ACROSS THE NRN
GREAT LAKES SOME WEAK Q-VECT CONV...SFC-700 MB MOISTENING AND LOW
LEVEL CONV SHOULD SUPPORT SCT LIGHT SNOW SHOWERS OR FLURRIES...PER
UPSTREAM OBS. THE GREATEST PCPN CHANCES AND POTENTIAL FOR SOME LIGHT
ACCUMULATIONS OF AN INCH OR LESS IS EXPECTED DOWNWIND FROM LAKE
SUPERIOR WHERE EVEN SMALL GAPS IN THE ICE COVER WILL ADD
HEAT/INSTABILITY. UPSLOPE FLOW INTO THE HIGHER TERRAIN WILL ALSO
PROVIDE ADDITIONAL SUPPORT FOR THE PCPN. LOOK FOR MIN TEMPS MAINLY IN
THE SINGLE DIGITS ABOVE ZERO BUT A FEW BLO ZERO READINGS ARE POSSIBLE
OVER THE EASTERN INTERIOR FCST AREA WHERE WINDS WILL BE LIGHTER AHEAD
OF THE FRONT IN THE EVENING.
TUESDAY...AS HIGH PRESSURE AND SUBSIDENCE BUILD INTO THE WRN
LAKES...THE 850-700 MB MOISTURE DEPARTS AND WINDS BACK TO
WRLY...EXPECT THE PCPN TO DIMINISH WITH ONLY A LIGHT DUSTING OF
ACCUMULATION AT MOST. WITH 925/850 MB TEMPS ONLY TO AROUND
-16/-22C...TEMPS WILL STRUGGLE THROUGH THE MID TEENS...MORE THAN 20
DEGREES BELOW SEASONAL AVERAGES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 450 AM EDT TUE MAR 25 2014
PRELIMINARY THOUGHTS ON LONG TERM FCST.
S WINDS OF WEDNESDAY WILL HELP RAISE TEMPS ABOUT 10F HIGHER THAN
WHAT WILL BE EXPERIENCED TODAY ACROSS THE CWA...ESPECIALLY W AND N.
THIS WILL BE DESPITE SNOW NEARING FROM THE NW. KEPT A SLIGHT CHANCE
FAR W BY LATE AFTERNOON...ALTHOUGH THE TREND IS TO SLOW DOWN THE
POPS EVEN MORE.
ANOTHER DAY CLOSER TO OUR WEDNESDAY NIGHT THROUGH THURSDAY EVENING
EVENT. WHILE FCST SOLUTIONS HAVE COME A BIT MORE IN LINE...THEY
COULD BE BETTER. EXPECT SIGNIFICANT IMPROVEMENTS AT THE DISTURBANCE
MOVES FROM THE PACIFIC OVER THE BETTER SAMPLED/MODELED CONTINENTAL
U.S.
WILL KEEP THE MENTION OF MODERATE WET SNOW...AND MIXED PRECIP IN THE
HWO. CONTINUE TO EXPECT THE MOST SNOW N AS WARM AIR SURGES IN FROM
THE S.
INCREASED POPS FOR DAY 6/MONDAY AS THE NEXT SFC LOW TRACKS FROM THE
N AND CENTRAL PLAINS SUNDAY AFTERNOON TO THE UPPER GREAT LAKES BY
12Z MONDAY. COMPARING THE 00Z RUNS...THE GFS HAS THE 996MB LOW NEAR
IWD...WHILE THE ECMWF CENTERS THE LOW ACROSS IA. WITH EITHER
SOLUTION...THE BEST CHANCE OF PRECIP LOOKS TO BE W UPPER MI. HAVE
ADDED LIKELY POPS FOR THE KEWEENAW PENINSULA FOR THE DAY MONDAY. AS
FOR SPECIFICS...WE WILL NEED TO WAIT. THE N SOLUTION WOULD BRING
MAINLY RAIN TO THE CWA...WHILE THE ECMWF WOULD RESULT IN MOSTLY
SNOW. WILL KEEP A MIX IN FOR NOW WITH THE BEST CHANCE OF SNOW NW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 119 AM EDT TUE MAR 25 2014
WITH THE PASSAGE OF A DISTURBANCE OVERNIGHT...SCT -SHSN WILL LIKELY
DEVELOP AT THE TAF SITES. BY LATE TONIGHT INTO TUE MORNING...THE
COMBINATION OF LOW LEVEL CONV AND UPSLOPE FLOW WILL BE ENOUGH TO
SUPPORT HIGH MVFR CIGS OR LOW VFR CIGS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 415 PM EDT MON MAR 24 2014
A COLD FRONT WILL MOVE THROUGH THE NRN LAKES TONIGHT. BEHIND THE
FRONT...WINDS WILL SHIFT TO THE NORTHWEST AND INCREASE TO 15 TO 25
KT TONIGHT AND 20 TO 30 KTS ON TUESDAY...WITH THE HIGHEST GUSTS OVER
THE EASTERN HALF OF LAKE SUPERIOR. WINDS WILL QUICKLY DIMINISH
TUESDAY NIGHT AND WEDNESDAY AS ANOTHER HIGH PRESSURE RIDGE MOVES
OVER THE AREA. A LOW PRESSURE SYSTEM DEVELOPING IN THE CENTRAL
PLAINS ON WEDNESDAY NIGHT AND THURSDAY WILL MOVE THROUGH THE GREAT
LAKES REGION LATE THURSDAY NIGHT AND FRIDAY. WIND STRENGTH/DIRECTION
WILL DEPEND ON THE EXACT TRACK OF THE LOW...BUT AT THIS TIME NORTH
TO NORTHEAST WINDS OF 15 TO 25 KTS ARE EXPECTED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
121 AM EDT TUE MAR 25 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 415 PM EDT MON MAR 24 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE OVER
WRN NOAM AND A TROUGH FROM HUDSON BAY THROUGH MUCH OF THE ERN CONUS.
AN UPSTREAM SHORTWAVE TROUGH AND ASSOCIATED ARCTIC COLD FRONT
EXTENDED FROM NEAR JAMES BAY TO FAR NW MN. TO THE NORTH OF THE FRONT
19Z TEMPS ONLY RANGED FROM 0F TO 5F. AT THE SFC...WRLY LOW LEVEL
FLOW PREVAILED AHEAD OF THE FRONT WITH ONLY SCT-BKN DIURNAL CU/SC
OVER UPPER MICHIGAN.
TONIGHT...AS THE SHORTWAVE TROUGH AND COLD FRONT MOVE ACROSS THE NRN
GREAT LAKES SOME WEAK Q-VECT CONV...SFC-700 MB MOISTENING AND LOW
LEVEL CONV SHOULD SUPPORT SCT LIGHT SNOW SHOWERS OR FLURRIES...PER
UPSTREAM OBS. THE GREATEST PCPN CHANCES AND POTENTIAL FOR SOME LIGHT
ACCUMULATIONS OF AN INCH OR LESS IS EXPECTED DOWNWIND FROM LAKE
SUPERIOR WHERE EVEN SMALL GAPS IN THE ICE COVER WILL ADD
HEAT/INSTABILITY. UPSLOPE FLOW INTO THE HIGHER TERRAIN WILL ALSO
PROVIDE ADDITIONAL SUPPORT FOR THE PCPN. LOOK FOR MIN TEMPS MAINLY IN
THE SINGLE DIGITS ABOVE ZERO BUT A FEW BLO ZERO READINGS ARE POSSIBLE
OVER THE EASTERN INTERIOR FCST AREA WHERE WINDS WILL BE LIGHTER AHEAD
OF THE FRONT IN THE EVENING.
TUESDAY...AS HIGH PRESSURE AND SUBSIDENCE BUILD INTO THE WRN
LAKES...THE 850-700 MB MOISTURE DEPARTS AND WINDS BACK TO
WRLY...EXPECT THE PCPN TO DIMINISH WITH ONLY A LIGHT DUSTING OF
ACCUMULATION AT MOST. WITH 925/850 MB TEMPS ONLY TO AROUND
-16/-22C...TEMPS WILL STRUGGLE THROUGH THE MID TEENS...MORE THAN 20
DEGREES BELOW SEASONAL AVERAGES.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 438 PM EDT MON MAR 24 2014
THE EXTENDED PORTION OF THE FORECAST IS TRENDING TOWARDS A MORE
ACTIVE AND SPRING LIKE PATTERN.
A HIGH PRESSURE RIDGE MOVING OVER THE UPPER GREAT LAKES REGION TO
START THE PERIOD WILL LEAD TO ANOTHER VERY COLD NIGHT ACROSS THE
UPPER GREAT LAKES REGION ON TUESDAY NIGHT. THERE ARE SOME CONCERNS
FOR CLOUDS LINGERING...BUT WITH THE VERY LIMITED OPEN WATER ON LAKE
SUPERIOR WOULD THINK THERE IS A LACK OF SUPPORT FOR LAKE ENHANCED
CLOUDS TO LINGER. THUS...WOULD EXPECT CLEARING SKIES AND A DECENT
OPPORTUNITY FOR RADIATIONAL COOLING WITH WINDS BECOMING LIGHT.
SINCE PWAT VALUES ARE AROUND 30 PERCENT OF NORMAL...OPTED TO TREND
TEMPS DOWN (BASED OFF THE LAST TWO NIGHTS OF LOWS)...ESPECIALLY IN
THE TRADITIONAL INTERIOR COLD SPOTS. THIS PRODUCES LOWS BELOW ZERO
OVER PRETTY MUCH ALL OF THE U.P. AND IN THE TEENS BELOW ZERO OVER
THE INTERIOR. BASED OFF THE TRENDS IN THE LONGER RANGE
MODELS...THIS WILL LIKELY BE THE LAST REALLY COLD NIGHT ACROSS THE
REGION.
THE SURFACE RIDGE WILL QUICKLY SHIFT EAST OF THE AREA ON WEDNESDAY
AND ALLOW SOUTHERLY FLOW TO DEVELOP AHEAD OF THE LOW TAKING SHAPE
IN THE CENTRAL PLAINS. THIS SOUTHERLY FLOW WILL ALLOW TEMPERATURES
TO QUICKLY WARM INTO THE 20S (AIDED BY MORNING SUNSHINE). BUT HIGH
CLOUDS WILL BE QUICKLY STREAMING OVER THE AREA THROUGH THE DAY
AHEAD OF THE NEXT SYSTEM. COULD EVEN SEE A ISOLATED SHOWER OR TWO
DEVELOPING UNDER THE MID LEVEL WAA LATE IN THE AFTERNOON.
THE FIRST WAVE FROM THE SYSTEM WILL AFFECT THE AREA ON WEDNESDAY
NIGHT...AS A SURFACE TROUGH EXTENDING NORTHEAST FROM THE DEVELOPING
SURFACE LOW MOVES EAST OVER THE CWA. BROAD MID LEVEL WARM AIR
ADVECTION AND ISENTROPIC ASCENT ON THE 280-295K SFCS SHOULD LEAD TO
A SWATH OF LIGHT SNOW. AS WITH THE NEXT SYSTEM...MODELS VARY
SIGNIFICANTLY WITH THE STRENGTH AND LOCATION OF THIS AREA OF
SNOW. THE 12Z ECMWF IS THE FARTHEST NORTH (OVER LAKE SUPERIOR) AND
WEAKEST...12Z CANADIAN FARTHEST SOUTH (ACROSS THE U.P.) AND
STRONGEST...WHILE THE GFS IS IN BETWEEN. FELT THAT THE GFS WAS A
GOOD COMPROMISE BETWEEN THE SOLUTIONS AND FOLLOWED THAT FOR TIMING
AND SNOWFALL AMOUNTS. THAT GIVES A GENERAL 1-3 INCHES OF SNOW FOR
THE CWA (GREATEST NORTH THIRD) THROUGH 12Z THURSDAY.
NEXT WAVE OF PRECIP WILL ARRIVE AS THE LOW PULLS OUT OF THE CENTRAL
PLAINS AND THROUGH THE GREAT LAKES REGION. STILL SOME DIFFERENCES IN
THE EXACT TRACK/TIMING BUT AT LEAST INITIALLY THE MODELS ARE
CONSISTENT IN A TROUGH EXTENDING NORTH-NORTHEAST OVER WESTERN LAKE
SUPERIOR. AS FOR THE LOW...THE 12Z GFS CONTINUES TO MOVE THE LOW
THROUGH MUCH FASTER THAN THE 12Z GEM AND 12Z ECMWF (270MI/520MI
NORTHEAST AT 12Z FRIDAY RESPECTIVELY). THE 12Z GEM WAS MUCH FARTHER
TO THE NORTHWEST AND BROUGHT IN MUCH MORE WARM AIR (0C 850MB LINE IN
FAR WESTERN UPPER MICHIGAN AT 00Z FRIDAY). 12Z ECMWF...EVEN WITH
IT/S FARTHER SOUTHWEST LOW TRACK (THROUGH CENTRAL LOWER MI ON
FRIDAY) HAS THE 0C 925MB TEMP AREA SLIDING THROUGH SOUTHERN
UPPER MICHIGAN DURING THE DAY THURSDAY. THE GFS ON THE OTHER
HAND...MOVES THE LOW THROUGH SO FAST THAT THE WARM AIR DOESN/T HAVE
TIME TO PULL INTO THE AREA AND KEEPS IT AS ALL SNOW.
ESSENTIALLY...THESE DIFFERENCES ARE DUE TO THE HANDLING OF THE
DISTURBANCE THAT IS WELL OFFSHORE IN THE PACIFIC AND WON/T COME ON
SHORE UNTIL TUESDAY NIGHT. IT WILL PROBABLY BE 24-36HRS BEFORE THE
MODELS CAN LOCK INTO A SOLUTION...BUT FEEL A SEVERAL MEMBER
COMPROMISE IS REASONABLE (GEM/ECMWF FOR TIMING AND GFS/ECMWF/UKMET
FOR TRACK AND ECMWF FOR THERMAL PROFILE). FELT WEIGHTING MORE
HEAVILY TOWARDS THE ECMWF WAS WARRANTED BASED OFF THE CONSISTENCY
IN THE LOW TRACK WITH THE 00Z ENSEMBLE MEMBERS.
UNFORTUNATELY...THESE DIFFERENCE IN THE LOW TRACK AFFECT BOTH THE
PRECIPITATION TYPE FOR A PORTION OF THE AREA AND ALSO WHERE THE
HEAVIEST PRECIPITATION WILL BE LOCATED WITH THE DEFORMATION BAND ON
THE BACKSIDE OF THE LOW. AS THE LOW IS TAKING SHAPE ON
THURSDAY...SHOULD SEE A TROUGH SETTING UP OVER WESTERN LAKE SUPERIOR
AND WOULD EXPECT THE HEAVIEST PRECIPITATION TO BE OVER THE WESTERN
THIRD OF THE CWA AND THE WESTERN LAKE AS IT WILL BE ENHANCED BY
MID-LEVEL FGEN. OVER THE REST OF THE AREA AND ESPECIALLY THE SOUTH
CENTRAL...WOULD EXPECT THE WAA PRECIPITATION TO SHIFT OUT AND
DIMINISH AND POTENTIALLY CUT OUT THE DEEPER MOISTURE ON THURSDAY.
THIS COULD LEAD TO MORE OF A FOG/DRIZZLE PERIOD...BUT WITH THE
UNCERTAINTY WITH THE LOW TRACK WILL JUST KEEP THINGS AS SNOW WITH
RAIN MIXED IN AT TIMES. THEN AS THE LOW MOVES UP AND THROUGH THE
AREA...THE HEAVIER BAND OF PRECIP WILL SHIFT EAST ACROSS THE CWA
THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. ALL IN ALL...THE
CONDITIONS WEDNESDAY NIGHT INTO FRIDAY MORNING WILL LIKELY LEAD TO A
PERIOD OF MESSY TRAVEL/COMMUTES AND WILL CONTINUE TO HIGHLIGHT IN
THE HWO.
BEHIND THE LOW...HIGH PRESSURE WILL SETTLE OVER THE AREA FOR FRIDAY
NIGHT AND INTO SATURDAY. 850MB TEMPS OF -12C ARE PRETTY MARGINAL
FOR ANY LAKE EFFECT IF POCKETS OF OPEN WATER DEVELOP ON LAKE
SUPERIOR...SO WILL GO WITH DRY CONDITIONS ON FRIDAY NIGHT. THE HIGH
WILL SHIFT EAST ON SATURDAY AND SOUTHERLY FLOW SHOULD LEAD TO HIGHS
IN THE 30S.
FOCUS THEN TURNS TO THE NEXT SERIES OF WAVES COMING FROM THE
WESTERN CONUS AND BRINGING ANOTHER UNSETTLED PERIOD TO THE AREA
THROUGH THE FIRST HALF OF NEXT WEEK. THE FIRST POTENTIAL WAVE LOOKS
TO RUN EAST ON THE U.S./CANADIAN BORDER ON SATURDAY NIGHT AND
SHOULD HAVE A LIMITED AFFECT ON THE LAND CWA. BEHIND THIS
WAVE...MUCH WARMER AIR WILL MOVE INTO THE AREA AND CURRENT
INDICATIONS ARE FOR TEMPERATURES TO BE AT OR EVEN SLIGHTLY ABOVE
NORMAL FOR SUNDAY. GFS CONTINUES TO SHOW ISSUES WITH SNOW COVER AND
SURFACE TEMPS...SO WILL LEVERAGE THE CANADIAN/ECMWF FOR HIGHS ON
SUNDAY. SHOULD SEE 40S OVER MUCH OF THE AREA (EXCEPT OVER THE EAST
WITH WINDS OFF LAKE MICHIGAN) AND THERE IS EVEN THE POTENTIAL FOR
SOME 50S ALONG THE WISCONSIN BORDER. THE NEXT SHORTWAVE AND COLD
FRONT WILL BE SHIFTING THROUGH THE AREA LATE SUNDAY AFTERNOON AND
SUNDAY NIGHT AND WITH THE EXPECTED THERMAL PROFILE...THAT
PRECIPITATION SHOULD MAINLY FALL AS RAIN. LIKE THE END OF THIS
WEEK...ANOTHER LOW TAKING SHAPE IN THE PLAINS STATES ON SUNDAY WILL
LIKELY MOVE THROUGH THE GREAT LAKES REGION ON MONDAY AND MONDAY
NIGHT...BRINGING ANOTHER WIDESPREAD PRECIPITATION EVENT TO THE AREA.
INITIAL THOUGH ON P-TYPE IS FOR A MIX INITIALLY AND TRANSITIONING TO
ALL SNOW THROUGH THE DAY/EVENING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 119 AM EDT TUE MAR 25 2014
WITH THE PASSAGE OF A DISTURBANCE OVERNIGHT...SCT -SHSN WILL LIKELY
DEVELOP AT THE TAF SITES. BY LATE TONIGHT INTO TUE MORNING...THE
COMBINATION OF LOW LEVEL CONV AND UPSLOPE FLOW WILL BE ENOUGH TO
SUPPORT HIGH MVFR CIGS OR LOW VFR CIGS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 415 PM EDT MON MAR 24 2014
A COLD FRONT WILL MOVE THROUGH THE NRN LAKES TONIGHT. BEHIND THE
FRONT...WINDS WILL SHIFT TO THE NORTHWEST AND INCREASE TO 15 TO 25
KT TONIGHT AND 20 TO 30 KTS ON TUESDAY...WITH THE HIGHEST GUSTS OVER
THE EASTERN HALF OF LAKE SUPERIOR. WINDS WILL QUICKLY DIMINISH
TUESDAY NIGHT AND WEDNESDAY AS ANOTHER HIGH PRESSURE RIDGE MOVES
OVER THE AREA. A LOW PRESSURE SYSTEM DEVELOPING IN THE CENTRAL
PLAINS ON WEDNESDAY NIGHT AND THURSDAY WILL MOVE THROUGH THE GREAT
LAKES REGION LATE THURSDAY NIGHT AND FRIDAY. WIND STRENGTH/DIRECTION
WILL DEPEND ON THE EXACT TRACK OF THE LOW...BUT AT THIS TIME NORTH
TO NORTHEAST WINDS OF 15 TO 25 KTS ARE EXPECTED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1234 AM CDT TUE MAR 25 2014
.UPDATE...
ISSUED AT 1233 AM CDT TUE MAR 25 2014
TOUGH TO GET A GRIP ON HOURLY TEMP TRENDS GIVEN VARIABLE WINDS/
CLOUDS ACROSS THE FCST AREA.
A BATCH OF MULTI-LAYERED CLOUDS IS MOVING THRU ASSOCIATED WITH A
WEAK SHORTWAVE TROF. SATELLITE TRENDS SUPPORT THE HI-RES RAP AND
THE NSSL WRF SYNTHETIC IR IMAGERY. WE EXPECT SKIES TO BE MOSTLY
CLEAR BY DAYBREAK OVER S-CNTRL NEB. N-CNTRL KS COULD START THE DAY
WITH MOSTLY CLOUDY SKIES...BUT EXPECT RAPID CLEARING AFTER
SUNRISE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 1233 AM CDT TUE MAR 25 2014
ALOFT: THE LONGWAVE FLOW WILL DEAMPLIFY OVER THE NEXT 24 HRS AS
TROF OVER THE E PAC GETS FORCED ONSHORE. NW FLOW TODAY WILL BEGIN
THE TRANSITION TONIGHT AS THE WRN USA RIDGE ADVANCES OVER THE
PLAINS.
SURFACE: STRONG HIGH PRES WAS SLIPPING SE AND WAS OVER THE
DAKOTAS THIS MORNING. THIS HIGH WILL SHIFT E INTO THE MS VALLEY
TODAY...WITH S FLOW DEVELOPING LATE. THE PRES GRADIENT WILL
INCREASE TONIGHT AS LOW PRES FORMS OVER MT AND LEE-SIDE TROFFING
DEVELOPS.
MORE LATER...
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 310 PM CDT MON MAR 24 2014
THE WEDNESDAY/THURSDAY PERIODS ARE LOOKING MORE ACTIVE
WEATHERWISE...THEN TEMPERATURES TREND UP FOR THE WEEKEND.
HEIGHTS RISE TUESDAY NIGHT AS A LOW AMPLITUDE UPPER RIDGE AXIS
BUILDS OUT OF THE ROCKIES AND ONTO THE CENTRAL PLAINS. AT THE
SURFACE...LOW PRESSURE SYSTEMS DEEPEN ALONG THE HIGH PLAINS IN SW SD
AND NW KS DURING THE AFTN WED. SOUTHERLY LLVL FLOW INCREASES IN A
TIGHTENING PRESSURE GRADIENT AHEAD OF THE APPROACHING SFC
TROUGH/COLD FRONT. SOUTHERLY WINDS ARE PROGGED TO INCREASE TO
WINDY CONDITIONS DURING THE AFTN...ESPECIALLY ACROSS THE EASTERN
HALF OF OUR CWA WHILE TO THE WEST WIND SPEEDS WILL BEGIN TO
DIMINISH AS THE TROUGH AXIS MOVES IN. MODEL FORECAST SOUNDINGS
INDICATE MIXING FOR OUR EASTERN AREAS AROUND H825 WITH WINDS AT
THE TOP OF THE LAYER NEAR 40KTS. THE LATEST GUIDANCE SUGGEST
SOUTHERLY WINDS NEARING WIND ADVISORY CRITERIA AND WILL NEED TO
MONITOR FOR A POTENTIAL HEADLINE AS THINGS GET CLOSER. THE STEADY
SOUTHERLY WINDS WILL ALSO DRAW MOISTURE NORTHWARD AND SFC DPS ARE
PROGGED TO RISE TO THE UPPER 30S/LOW 40S WITH THE HIGHER DPS
PROGGED TO POOL N/S ALONG THE SFC TROUGH. THE NAM IS THE MOST
ROBUST WITH THE HIGHER DPS AND EVEN SUGGEST READING IN THE UPPER
40S/NEAR 50F NEAR THE WESTERN EDGE OF OUR CWA. WITH THE HIGHER DPS
PROGGED...INSTABILITY PARAMETERS INCREASE ALONG OUR WESTERN CWA
IN THE AFTN WITH MUCAPES PROGGED JUST OVER 1000 J/KG. THE PROGGED
INSTABILITY PER THE NAM MAY BE ON THE HIGH SIDE...BUT EVEN THE
SREF HAS LIKELY PROBS OF INSTABILITY GREATER THAN 500 J/KG. WITH
SUPPORT OF OTHER MODELS WILL GO AHEAD AND INSERT THE POTENTIAL FOR
THUNDER IN THE EVENING. TEMPERATURES WILL BE QUITE MILD WITH H85
TEMPS RANGING FROM 5 TO 15C E/W AND TEMPS SHOULD REACH THE UPPER
50S TO UPPER 60S FOR HIGHS...AND MAY APPROACH 70F IN THE WEST
WHICH ARE AROUND CONVECTIVE TEMPS. ALSO HAVE CONCERNS FOR FIRE
WEATHER CONDITIONS AND WILL NEED TO MONITOR HOW MUCH MOISTURE
ACTUALLY ADVECTS NORTH VS MIXES OUT WITH THE STEADY/GUSTY WINDS.
CURRENT RELATIVE HUMIDITY FORECAST KEEPS RH VALUES ABOVE CRITICAL
FIRE WEATHER CONDITIONS.
THERE ARE MODEL DIFFERENCES ON THE STRENGTH OF THE MID LEVEL
SHORTWAVE TROUGH...AND HOW PROGRESSIVE THE SYSTEM WILL BE AS IT
CROSSES THE CENTRAL PLAINS. THE 00Z ECMWF...12Z GEM...AND 12Z
UKMET ALL SUGGEST A DEEPER/SLOWER SYSTEM TO IMPACT THE CENTRAL
PLAINS AND GENERATE BANDED PCPN DUE TO FRONTOGENESIS AND
DEFORMATION AS THE H7 LOW CLOSES OFF. THESE MODELS ARE THE WORSE
CASE SCENARIO FOR OUR AREA AND DEVELOP A BAND OF SNOWFALL ACROSS
PORTIONS OF WESTERN/NORTHERN AND CENTRAL NEBRASKA...WHILE FARTHER
SOUTH INTO KANSAS THE MAJORITY OF THE AREA IS DRY SLOTTED
INITIALLY WITH CHCS FOR PCPN INCREASING AS COLD FRONT/MID LEVEL
TROUGH MOVE THROUGH. BOTH THE NAM...GFS AND 12Z ECMWF ARE
PROGRESSIVE WITH THE SYSTEM WITH JUST A QUICK SHOT OF PCPN WITH
THE COLD FRONT AND WEAKER TROUGH WITH SOME CHC FOR A TEMP RECOVERY
IN OUR WEST BEHIND THE SYSTEM. HARD TO TELL WHICH SOLUTION WILL
VERIFY IN THIS COMPLICATED TIME FRAME AND WPC DISCUSSION FAVORS
THE ECMWF/UKMET. SINCE THERE IS STILL A FAIR AMOUNT OF
UNCERTAINTY...FEEL COMFORTABLE WITH CHANCE POPS ATTM WHICH CAN BE
ADJUSTED UP/DOWN AS THINGS GET CLOSER. PCPN TYPE WILL BE
DEPENDENT UPON STRENGTH OF SYSTEM AND LLVL TEMP PROFILE BUT AT
LEAST SOME CHC OF SNOW LOOKS REASONABLE WITH SNOW ACCUMULATIONS
POSSIBLE. TEMP TREND LOOKS BE NON DIURNAL WITH CAA BEHIND THE
FRONT.
BEYOND THURSDAY...HEIGHTS RISE AGAIN AND A WARMER AIR SETTLES IN FOR
SEVERAL DAYS WITH TEMPS REACHING THE 60S/70S FOR THE WEEKEND BEFORE
ANOTHER COOL FRONT ARRIVES MONDAY.
&&
.AVIATION...(FOR THE 06Z TAF THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1233 AM CDT TUE MAR 25 2014
THRU 12Z: MULTI-LAYERED VFR CIGS WILL DEPART WITH CLEARING
EXPECTED BY 10Z. NW WINDS 8-12 KTS. CONFIDENCE: HIGH
TUE: ESSENTIALLY VFR SKC. WINDS WILL AVERAGE NW AROUND 10 KTS
UNTIL 18Z. THEN WINDS WILL GRADUALLY SHIFT TO WSW BY 23Z.
CONFIDENCE: HIGH
TUE EVE: VFC SKC. WINDS WILL CONTINUE SHIFTING THRU SW-S-SE AND
WILL INCREASE TO AROUND 15 KTS BY 05Z. THERE COULD BE SOME
OCCASIONAL GUSTINESS. LLWS WILL BECOME A PROBLEM AFTER 06Z.
CONFIDENCE: HIGH
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...HALBLAUB
LONG TERM...FAY
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
344 AM EDT TUE MAR 25 2014
.SYNOPSIS...
A CHILLY RAIN WILL OVERSPREAD THE AREA TODAY AS DEEPENING LOW
PRESSURE OFFSHORE TRACKS NORTHEAST OFF OUR COAST. THE RAIN WILL
TAPER OFF LATE TONIGHT FOLLOWED BY WINDY AND COLDER CONDITIONS
AS THE LOW DEEPENS AND CANADIAN HIGH PRESSURE BUILDS FROM THE
WEST. NEAR TO BELOW FREEZING TEMPERATURES ARE EXPECTED EARLY ON
WEDNESDAY AND AGAIN THURSDAY. A WARMING TREND WILL PREVAIL LATE
IN THE WEEK INTO NEXT WEEKEND...WITH A WEAK COLD FRONT POSSIBLY
CROSSING THE AREA EARLY ON SUNDAY. FAIR AND DRY EARLY NEXT WEEK
AS HIGH PRESSURE MOVES OVER THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM TUESDAY...A LOW PRESSURE CENTER ROUGHLY 300 MILES
SOUTH OF CAPE FEAR EARLY THIS MORNING WILL TRACK TO THE NE AND
DEEPEN RAPIDLY TODAY...TO APPROXIMATELY A 997 MB LOW 250 MILES
EAST OF CAPE FEAR BY 21Z/5PM. THE BOMBING SURFACE LOW ALTHOUGH
WELL OFFSHORE...IN TANDEM WITH AN APPROACHING TROUGH/COOL POOL
ALOFT...WILL SET OFF PRECIPITATION TODAY. INITIALLY STRATIFORM
RAIN ACROSS OUR EASTERN HALF...WILL TRANSITION TO MORE SHOWERY
TYPE PRECIPITATION AREA-WIDE INTO AFTERNOON AS THE UPPER TROUGH
TRAVERSES THE REGION.
NORMALLY AN UPPER TROUGH IN SPRING RAISES A FLAG TO INTERROGATE
THE SEVERE WEATHER POTENTIAL. IN THIS CASE ALL OF THE FAVORABLE
INGREDIENTS REMAIN LINKED TO THE SURFACE FEATURE OFFSHORE. COOL
LOW-LEVELS OVER LAND AND LOW DEWPOINTS SHOULD PREVENT ROBUST
CONVECTION. HAIL SHOWERS THIS TIME OF YEAR BECOME MORE COMMON
BUT AM NOT SEEING THE VERTICAL VELOCITIES TODAY SUPPORTING THIS.
A FREEZE WATCH HOISTED FOR ALL ZONES FOR EARLY WEDNESDAY MORNING.
CONFIDENCE IS NOT HIGH THAT ALL ZONES WILL DROP BELOW 32 DEGREES
SINCE LOW-LEVEL WINDS WILL BE ELEVATED...AND RESIDUAL CLOUDS MAY
LINGER LATE IN THE NIGHT. IT APPEARS THE BEST CHANCE OF FREEZING
IS INLAND...WHILE CLOSER TO THE COAST...CONFIDENCE LEVEL FALLS.
THUS A WATCH IS IN EFFECT TO ALLOW THE 12Z MODEL DATA SUITE TO
HOPEFULLY PROVIDE ADDITIONAL RESOLUTION IN SEGMENTING A WARNING
VERSUS NO FREEZE WARNING. COUPLING IN WIND...THE APPARENT TEMPS
OR WIND-CHILLS...WILL FALL INTO THE LOW TO MID 20S PRIOR TO AND
THROUGH DAYBREAK ON WEDNESDAY.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 345 AM TUESDAY...THE MAIN EMPHASIS OF THE SHORT TERM WILL BE
THURSDAY MORNING WHEN ARCTIC HIGH PRESSURE SETTLES DIRECTLY
OVERHEAD. THIS COURTESY OF A RELATIVELY DEEP ALBEIT PROGRESSIVE
EAST COAST TROUGH.
GUIDANCE HAS IF ANYTHING JOGGED DOWN A BIT AS HAS THE OFFICIAL
FORECAST. MUCH LIKE A COUPLE OF WEEKS AGO WHEN GUIDANCE WAS VERY
CONSISTENT FOR SEVERAL CYCLES/DAYS...THERE APPEARS TO BE NO
MITIGATING FACTORS FOR A SIGNIFICANT LATE SEASON FREEZE. RETURN FLOW
CONTINUES TO SET UP LATER LATER THURSDAY WITH WHAT SEEMS TO BE A
GOOD SEA FOG SIGNAL FROM THE GFS. ONE FINAL NOTE...WITH THE
AFOREMENTIONED CONFIDENCE SIGNALS FOR A FREEZE...WOULD NORMALLY
ISSUE A NPW BUT WILL HAVE TO LET A MORE MARGINAL EVENT TRANSPIRE FOR
WEDNESDAY A.M.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 345 AM TUESDAY...ZONAL FLOW ALOFT CONTINUES TO ADVERTISE ONE SYSTEM
MOVING ACROSS THE TENNESSEE VALLEY SATURDAY/EARLY SUNDAY. GUIDANCE
HAS COME INTO SLIGHTLY BETTER AGREEMENT THIS MORNING ON THIS
SCENARIO. CONTINUED TO ADVERTISE POPS FOR FRIDAY AS WELL WITH LOW
LEVEL CONVERGENCE AND PRE FRONTAL TROUGH. I DID ADD SLIGHT COVERAGE
OF THUNDER AS WELL. MORE CONFIDENCE IN DRY CONDITIONS SUNDAY AND
MONDAY. TEMPERATURE GUIDANCE HAS TRENDED DOWN A LITTLE WITH FOR
THESE DAYS AS HAS THE OFFICIAL FORECAST.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
AS OF 06Z...MID LEVEL CIGS ARE SPREADING ACROSS THE CWA TONIGHT AS
SURFACE LOW PRESSURE ORGANIZES OFF THE FLORIDA COAST. EARLIER
FORECAST APPEARS ON TRACK AS THE LATEST HRRR RUNS INDICATE RAIN WILL
SPREAD UP THE COAST FROM SOUTH TO NORTH EARLY THIS MORNING. HAVE
NUDGED THE TIMING OF PCPN BACK A BIT WITH THIS TAF ISSUANCE...BUT
STILL EXPECT KMYR/KCRE TO SEE -RA BEFORE 12Z. WITH THE OFFSHORE
TRACK OF THE LOW...EXPECT PCPN AND MVFR CIGS TO BE FOCUSED ALONG THE
COAST. HAVE INCLUDED TEMPO MVFR FOR THE COASTAL TERMS IN THE LATE
MORNING/EARLY AFTERNOON AS RAIN WILL HELP TO LOWER CIGS. E-NE WINDS
5-10 KTS THIS MORNING WILL BECOME NORTHWEST AFTER 18Z AS THE LOW
PROGRESSES FURTHER UP THE COAST. COULD SEE NORTHWEST WIND GUSTS OF
15-20 KTS BY LATE AFTERNOON/EARLY EVENING ON THE BACKSIDE OF THE
LOW. CONDITIONS WILL IMPROVE TO VFR FROM SOUTHWEST TO NORTHEAST THIS
EVENING...BECOMING VFR AT ALL SITES SHORTLY AFTER 00Z WEDNESDAY.
EXTENDED OUTLOOK...VFR ON WEDNESDAY AND THURSDAY. CHANCE OF SHOWERS
WITH TEMPO MVFR CONDITIONS POSSIBLE ON FRIDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM TUESDAY...GALE FLAGS RAISED FOR RAPIDLY INTENSIFYING
NW WINDS LATE THIS AFTERNOON THROUGH TONIGHT AS A POWERFUL AND
RAPIDLY DEEPENING SURFACE LOW PASSES WELL EAST OF THE COASTAL
WATERS. ITS INTERACTION WITH APPROACHING CANADIAN HIGH PRESSURE
WILL DRIVE 25-40 KT WINDS FROM THE NW TONIGHT...HIGHEST OFFSHORE.
HIGHEST SEAS AS WELL OFFSHORE IN THE NW WIND TRAJECTORY. THE OCEAN
WILL BECOME DANGEROUS LATER TODAY AS THE NW WIND RIPS ACROSS
STRONG SE WAVE ENERGY...MAKING FOR A PITCHY AND TUMULTUOUS SEA
BEHAVIOR. MARINERS ARE ADVISED TO REMAIN IN PORT TONIGHT. TSTMS
SHOULD REMAIN CONFINED TO THE GULF STREAM THROUGH EARLY WEDNESDAY.
SEA HEIGHTS PEAKING 4 TO 8 FT TONIGHT...BUT DROPPING TO 3 TO 6 FT
INTO FIRST LIGHT OF WEDNESDAY.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 345 AM TUESDAY...MUCH LIKE THE PUBLIC PART OF THE FORECAST
GUIDANCE...WINDS AND SEAS REMAIN RELATIVELY UNCHANGED. STILL EXPECT
RUGGED CONDITIONS FOR MOST OF THE DAY WEDNESDAY AS SEAS WILL REMAIN
CHURNED UP AS WINDS DIMINISH.
INITIAL WIND SPEEDS WILL BE 20-25 KNOTS FROM THE NORTHWEST
DECREASING TO 10-15 BY MID EVENING. BY THURSDAY WINDS DROP EVEN
FURTHER AS SURFACE HIGH PRESSURE DRIFTS DIRECTLY OVERHEAD. EXPECT
SPEEDS OF TEN KNOTS OR LESS. LATER THURSDAY WINDS SLOWLY RECOVER TO
10-15 KNOTS THIS TIME FROM THE SOUTHEAST.
SEAS WILL CERTAINLY BE MORE ROBUST ACROSS THE OUTER PORTIONS OF THE
COASTAL ZONES WITH THE OFFSHORE FLOW. EXPECT 3-5 FEET WITH
POSSIBLE SIX FOOTERS FOR MOST OF THE DAY WITH HEIGHTS DROPPING
DRAMATICALLY THURSDAY.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 345 AM TUESDAY...WINDS WILL INITIALLY BE FROM THE SOUTH AT
A FAIRLY DECENT CLIP...15-20 KNOTS AND THERE MAY BE SOME SEA FOG
TO CONTEND WITH AS WELL. WITH AN INITIAL SURFACE SYSTEM LOSING
SOME STRENGTH...WINDS ACTUALLY DECREASE SLIGHTLY FOR SATURDAY
WHILE SWITCHING TO THE NORTH VERY LATE. NOT A STRONG SURGE OF COLD
AIR WITH THIS ONE KEEPING SPEEDS RELATIVELY LIGHT. SEAS ARE 3-5
FEET EARLY WITH THE PERSISTENCE AND STRENGTH OF THE RETURN FLOW
DIMINISHING A BIT WITH WIND SPEEDS LATER.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FREEZE WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING FOR
SCZ017-023-024-032-033-039-053>056.
NC...FREEZE WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING FOR
NCZ087-096-099-105>110.
MARINE...GALE WARNING FROM 6 PM THIS EVENING TO 6 AM EDT WEDNESDAY FOR
AMZ250-252-254-256.
&&
$$
SYNOPSIS...MJC
NEAR TERM...MJC
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...MJC/BJR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
252 AM EDT TUE MAR 25 2014
.SYNOPSIS...A COMPLEX LOW PRESSURE SYSTEM WILL RAPIDLY INTENSIFY
WHILE TRACKING UP THE CAROLINA AND MIDDLE ATLANTIC COASTS THROUGH
TONIGHT. MODIFIED ARCTIC HIGH PRESSURE WILL FOLLOW BEHIND THE SYSTEM
FOR THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY NIGHT/...
AS OF 1010 PM MONDAY...
THROUGH MID-MORNING TUESDAY... REGIONAL SURFACE ANALYSIS THIS
EVENING SHOWS WEAK HIGH PRESSURE JUST EAST OF THE DELMARVA... AN
INVERTED TROUGH EXTENDING UP THE APPALACHIANS...AND A WEAK LOW
FORMING EAST OF DAYTONA. ALOFT... RAOBS SHOW WESTERLY FLOW OVER THE
SOUTHEAST US AND A SHORTWAVE TROUGH MOVING INTO THE MID MS RIVER
VALLEY REGION. THIS LEAD SHORTWAVE WILL HELP DRIVE THE DEVELOPING
SURFACE LOW NORTHEAST INTO THE ATLANTIC TONIGHT AND EARLY TUESDAY.
MEANWHILE...A 125KT UPPER JET DIVING THROUGH THE CENTRAL PLAINS WILL
BEGIN TO AMPLIFY THE UPPER LEVEL FLOW LATE TONIGHT...LEADING TO A
SECONDARY SURFACE LOW EAST OF CAPE HATTERAS BY TUESDAY EVENING.
UPSTREAM THIS EVENING...PRECIP ASSOCIATED WITH THE LEAD SHORTWAVE IS
DRYING UP...BY EXPECT PRECIP TO REDEVELOP FROM THE SOUTHERN
APPALACHIANS TO THE BLUE RIDGE BY AROUND 08Z AS THE UPPER TROUGH
AMPLIFIES AND DCVA/HEIGHT FALLS BEGIN TO INCREASE. TO THE
SOUTHEAST... PRECIP WILL ALSO BREAK OUT WITH SLOWLY STRENGTHENING
LOW LEVEL WARM ADVECTION AND CYCLOGENESIS OVER THE SOUTH CAROLINA
COASTAL AREA...THOUGH MOST OF THE CONVECTION ALLOWING MODELS NOW
KEEP PRECIP SOUTHEAST OF SAMPSON AND WAYNE COUNTIES THROUGH 12Z.
WITH THE AFOREMENTIONED AREAS OF FORCING NOT LINKING UP UNTIL
TUESDAY AFTERNOON AS THE SYSTEM BEGINS TO LIFT AWAY FROM THE AREA
AND DEEPEN...MODELS CONTINUE SHOW SHOW RELATIVELY LIGHT QPF AMOUNTS
AROUND ONE TENTH OF AN INCH IN THE NORTHWEST AND SOUTHEAST PORTIONS
OF THE CWA PRIOR TO 15Z.
REGARDING THE CHANCE OF SNOW IN THE NORTHWEST PIEDMONT...THE NAM AND
GFS FORECAST SOUNDINGS STILL SHOW SIGNIFICANTLY DIFFERENT BOUNDARY
LAYER MOISTURE...WITH THE NAM SATURATING MUCH MORE RAPIDLY THAN THE
GFS. THE LATEST RAP APPEARS TO BE SOMEWHERE IN BETWEEN. IN ANY
CASE...WETBULB PROFILES CONTINUE TO SUPPORT THE POTENTIAL FOR BURSTS
OF SNOW WITH HEAVIER PRECIP RATES...WITH THE BEST CHANCE BETWEEN 10Z
AND 14Z.. WITH NEAR SURFACE TEMPERATURES AT OR A LITTLE ABOVE
FREEZING...AND TOP SOIL TEMPS IN THE LOW-MID 40S...ANY SNOW THAT
OCCURS WILL LIKELY MELT ON IMPACT. THE EXCEPTION TO THIS WILL BE
"IF" A BURST OF MODERATE TO HEAVY SNOW WERE TO OCCUR...QUICKLY
COATING GRASSY AREAS AND THE TOPS OF CARS.
AS THE BULK OF THE PRECIP TRANSITIONS TOWARD EASTERN NC AND TEMPS
WARM A FEW DEGREES...ANY LINGERING PRECIP OVER THE NORTHWEST AND
NORTHERN PIEDMONT WILL BECOME ALL RAIN BY MIDDAY. -SMITH
TUESDAY AFTERNOON...THE NORTHERN STREAM S/W WILL TAKE ON A NEGATIVE
TILT AS IT CROSSES THE MID ATLANTIC STATES. THIS WILL LEAD TO SFC
CYCLOGENESIS OFF OF HATTERAS BY LATE TUESDAY WITH RAPID DEEPENING
TUESDAY NIGHT AS IT LIFTS TO THE N-NE. THIS MOVEMENT WILL TAKE THE
BULK OF THE PRECIP AWAY FROM CENTRAL NC BY EARLY TUESDAY
EVENING..WITH CLEARING SKIES DURING THE EVENING HOURS.
THE DEEPENING LOW COUPLED WITH ANOTHER CANADIAN HIGH OVER THE MID MS
VALLEY WILL CREATE BLUSTERY NW WINDS ACROSS CENTRAL NC LATE TUESDAY
THROUGH TUESDAY NIGHT. EXPECT WIND GUSTS 20-25 MPH WELL INTO THE
NIGHT. THIS WIND WILL ALSO USHER ANOTHER BATCH OF COOL DRIER AIR
INTO CENTRAL NC. THE WIND COUPLED WITH COLD AIR WILL RESULT IN WIND
CHILL VALUES IN THE UPPER TEENS TO AROUND 20 DEGREES LATE TUESDAY
NIGHT. MIN TEMPS MID 20S NW TO NEAR 30 SE. -WSS
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 250 AM TUESDAY...
WED AND WED NIGHT: IN THE WAKE OF THE BOMBING CYCLONE TRACKING UP
THE MIDDLE ATLANTIC AND NEW ENGLAND COASTS...A STILL STRONG MSL
PRESSURE GRADIENT - AND ASSOCIATED CONTINUED BLUSTERY NW WINDS -
WILL RELAX/ABATE THROUGHOUT THE AFTERNOON...AS THE CENTER OF
MODIFIED ARCTIC HIGH PRESSURE BUILDS ACROSS THE APPALACHIANS. ASIDE
FROM INCREASING HIGH CLOUDS WITH THE APPROACH OF A SOUTHERN STREAM
WAVE ALOFT BY THU MORNING...PARTICULARLY OVER THE SOUTHERN PIEDMONT
AND SANDHILLS...THE PRESENCE OF THE HIGH WILL YIELD MAINLY CLEAR AND
CHILLY CONDITIONS. TEMPERATURES WITHIN A FEW DEGREES EITHER SIDE OF
45 AND 25 DEGREES FOR HIGHS AND LOWS...RESPECTIVELY...WITH THE
LATTER SUPPORTED BY STRONG RADIATIONAL COOLING WITH THE CENTER OF
THE HIGH OVERHEAD. DESPITE THESE CHILLY CONDITIONS...THE COMBINATION
OF STRONG NW WINDS AND MINIMUM RELATIVE HUMIDITY VALUES AROUND 25
PERCENT OWING TO THE DRY ARCTIC AIR MASS - THOUGH WITH ONLY A BRIEF
OVERLAP OF THESE CONDITIONS DURING THE EARLY AFTERNOON HOURS (IE. RH
HIGHER WHEN WINDS ARE HIGHER EARLY IN THE DAY...THEN WINDS DIMINISH
AS RH DROPS LATE IN THE AFTERNOON)...MAY PRODUCE INCREASED FIRE
DANGER. WE WILL LIKELY COORDINATE WITH THE NCFS REGARDING THIS
POTENTIAL LATER TODAY. -MWS
THURSDAY: THURSDAY WILL START OUT WITH A STRONG 1035 MB SURFACE HIGH
PRESSURE CENTERED OVER COASTAL NC. WHILE THE DAY MIGHT START OUT
FAIRLY CLOUD FREE...EXPECT MID AND UPPER LEVEL CLOUDS TO QUICKLY
SHROUD MOST OF THE CWA BY LATE MORNING/EARLY AFTERNOON. DESPITE THE
CLOUD COVER...NO PRECIPITATION IS EXPECTED. WHILE GUIDANCE SUGGESTS
MAX TEMPERATURES IN THE UPPER 50S...THICKNESSES AND CLOUD COVER
SUGGEST COOLER TEMPS...FOR NOW WILL GO MID 50S NORTH TO UPPER 50S IN
THE SOUTH. -ELLIS
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 240 AM TUESDAY...
THURSDAY NIGHT THROUGH SATURDAY NIGHT: THE FIRST HALF OF THE LONG
TERM IS SETTING UP TO BE A FAIRLY WET PERIOD WITH THE FIRST ACT
BEGINNING WITH AN IN-SITU DAMMING EVENT AS THE 1035 MB SURFACE HIGH
MOVES OUT INTO THE WESTERN ATLANTIC. ISENTROPIC LIFT HIGHLIGHTED ON
THE 290 K SURFACE SUPPORTS AT LEAST SOME LOW LEVEL CLOUDS MOVING
INTO CENTRAL NC WITH PERHAPS EVEN SOME VERY LIGHT PRECIPITATION.
OVERNIGHT LOWS IN TEH LOW TO MID 40S.
ON FRIDAY SURFACE LOW PRESSURE WILL MOVE THROUGH THE GREAT LAKES
WITH AN ATTENDANT COLD FRONT STRETCHING SOUTHWESTWARD. EARLY IN THE
DAY...MOISTURE TRANSPORT AND CONVERGENCE WILL INCREASE SIGNIFICANTLY
THROUGH THE DAY ON FRIDAY WITH PRECIPITABLE WATER VALUES RISING
ABOVE AN INCH BY FRIDAY AFTERNOON 1.25 INCHES BY EVENING. THE MAIN
PRE-FRONTAL PRECIPITATION WILL HOLD BACK ACROSS THE MOUNTAINS FRIDAY
MORNING AND ANY PRECIPITATION OCCURRING ACROSS CENTRAL NC WOULD BE
LIGHT AND ASSOCIATED MORE WITH MOISTURE CONVERGENCE IN THE SOUTHERLY
RETURN FLOW. THAT WILL CHANGE AFTER 18Z HOWEVER...WHEN PRECIP
OVERSPREADS MUCH OF THE CWA. MODEL FORECAST SOUNDINGS ARE VERY WET
THROUGH THE COLUMN WITH SOME BUT VERY WEAK INSTABILITY. WHILE BULK
SHEAR WILL BE AROUND 40 KTS...THE WEAK CAPE VALUES LOOK TO ONLY
SUPPORT SHOWERS BUT CAN NOT RULE OUT A FEW THUNDERSTORMS IN THE
EXTREME SOUTHEAST. THERE IS SOME UNCERTAINTY AS TO COVERAGE AND QPF
AMOUNTS AT THIS TIME BUT WILL KEEP A COUPLE TENTHS OF AN INCH
POSSIBLE BY THE END OF THE EVENING ON FRIDAY. TEMPERATURES IN THE
LOW 60S NW TO UPPER 60S SE. THE FRONT WILL HAVE TROUBLE GETTING
THROUGH THE AREA ON FRIDAY NIGHT AND AT THIS POINT LOOKS LIKE
CENTRAL NC WILL REMAIN IN THE WARM SECTOR AT LEAST INTO SATURDAY
MORNING. LOWS UPPER 40S TO MIDDLE 50S.
SATURDAY WILL CONTINUE TO BE WET AS THE FRONT LINGERS NORTHWEST OF
THE AREA. THIS WONT LAST FOREVER THOUGH AS THE UPPER TROUGH BEGINS
TO DIG INTO THE MISSISSIPPI VALLEY AND WILL EVENTUALLY GIVE THE
SUPPORT NEEDED TO PUSH THE FRONT THROUGH AND THE SYSTEM OUT TO SEA.
THE DETAILS OF HOW THIS WILL EVOLVE THOUGH REMAIN IN QUESTION BUT
ARE NOW COMING INTO BETTER AGREEMENT. BOTH MODELS NOW DEVELOP A
SOUTHERN STREAM WAVE WEST OF THE MOUNTAINS AND MOVE NORTH OF THE
AREA THROUGH THE MID ATLANTIC...PUSHED OUT TO SEA BY THE UPPER
TROUGH WHERE IT WILL LINK UP WITH A WEAKER WAVE OF LOW PRESSURE
COMING OUT OF THE GULF OF MEXICO AND UP THE EAST COAST. AN UPPER LOW
MOVES ACROSS NC BUT DOES NOT REALLY PHASE WITH THE LOW COMING UP THE
COAST. SATURDAY WILL BE WET AND OVERCAST WITH HIGHS IN THE MID TO
UPPER 60S. FORECAST SOUNDINGS SHOW MUCH BETTER INSTABILITY ON
SATURDAY THAN FOR FRIDAY WITH AS MUCH AS 800 J/KG IN THE SOUTHEAST
WITH 35-40 KTS OF BULK SHEAR MAKING THUNDERSTORMS A MUCH BETTER
POSSIBILITY FROM THE TRIANGLE SOUTH AND EASTWARD THAN ON FRIDAY
AFTERNOON. WILL INCLUDE THE CHANCE FOR THUNDER IN THE FORECAST FOR
SATURDAY EVENING WITH FURTHER DETAILS TO BE IRONED OUT IN THE COMING
DAYS. THE FRONT WILL CROSS THE AREA SATURDAY NIGHT WITH WINDS
SHIFTING FROM SOUTHWESTERLY TO NORTHERLY WITH PRECIPITATION ENDING
AROUND DAYBREAK SUNDAY MORNING. LOWS SATURDAY NIGHT LOW TO MID 40S.
SUNDAY THROUGH MONDAY: MUCH DRIER FOR SUNDAY AND MONDAY AS SURFACE
HIGH PRESSURE EXTENDS ACROSS THE EASTERN SEABOARD WITH RIDGING
ALOFT. MONDAY WILL START OUT COOL ON THE EASTERN SIDE OF THE SURFACE
HIGH WITH NORTHERLY WINDS BUT THESE WILL BECOME VARIABLE BY MONDAY
AFTERNOON WITH HIGH PRESSURE MOVING MORE DIRECTLY OVERHEAD AND THEN
EAST OF THE AREA. HIGHS MONDAY IN THE MIDDLE 60S. LOWS IN THE UPPER
30S TO LOW 40S. A WARMING TREND FOR MONDAY AS SOUTHERLY RETURN FLOW
TAKES OVER AND THICKNESSES INCREASE BACK INTO THE 1350S. THIS SHOULD
SUPPORT HIGHS IN THE UPPER 60S TO NEAR 70 DEGREES.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 225 AM SATURDAY...
INITIALLY VFR CONDITIONS IN A DRY...EARLY SPRING ARCTIC AIR
MASS...WILL YIELD TO RAPIDLY DEVELOPING AND LOWERING MID LEVEL
CEILINGS AND VIRGA THIS MORNING...AS A POTENT UPPER LEVEL
DISTURBANCE PIVOTS ACROSS THE APPALACHIANS TOWARD CENTRAL NC. THIS
PRECIPITATION ALOFT WILL STEADILY SATURATE THE LOW LEVELS...SUCH
THAT CONDITIONS WILL BECOME AT LEAST MVFR ACROSS ALL OF CENTRAL
NC...AND LIKELY IFR AT TRIAD TERMINALS AND KRWI. THE PRECIPITATION
WILL FALL INITIALLY AS SNOW OR A SNOW/RAIN MIX AT TRIAD TERMINALS
BETWEEN 12-16Z...WITH RAIN ELSEWHERE. THE DEEP MOIST AXIS AND
ASSOCIATED MAIN BAND OF PRECIPITATION WILL THEN MOVE NORTHEAST OF
OUR AREA AND PROVIDE FOR A RETURN TO VFR CONDITIONS...WITH A
DEVELOPING GUSTY NORTHWESTERLY WIND AS THE BOUNDARY LAYER
DEEPENS...THIS AFTERNOON. A BAND OR TWO OF MOSTLY VFR RAIN SHOWERS
WILL THEN DEVELOP AND ACCOMPANY ANOTHER POTENT UPPER LEVEL
DISTURBANCE FORECAST TO PIVOT ACROSS NC BETWEEN 18-00Z. HAVE
ACCOUNTED FOR THIS POTENTIAL WITH A MENTION OF VICINITY SHOWERS IN
THE TAFS AT THIS TIME. TEMPO GROUPS MAY BE ADDED LATER FOR THIS
POTENTIAL AS TIMING AND LOCATION BECOME CLEARER. CLEARING AND
STRENGTHENING NW WINDS IN THE 12-18 KT RANGE WITH GUSTS TO 25-30
KTS...WILL DEVELOP THIS EVENING...AND CONTINUE OVERNIGHT.
OUTLOOK: THE BLUSTERY CONDITIONS WILL ABATE AROUND MIDDAY-EARLY
AFTERNOON WEDNESDAY. RETURN FLOW MOISTURE WILL RESULT IN MVFR-IFR
STRATUS...AND AREAS OF DRIZZLE OR LIGHT RAIN AT TRIAD TERMINALS...
LATE THU NIGHT-EARLY FRI. THIS LOW CLOUD COVER AND RAIN WILL THEN
SPREAD EAST ACROSS THE REMAINDER OF CENTRAL NC WITH THE APPROACH OF
A FRONTAL SYSTEM FROM THE WEST...WITH MVFR OR LOW VFR CEILINGS...ON
FRI. PERIODS OF SUB-VFR CONDITIONS MAY THEN CONTINUE THROUGH SAT
NIGHT...AS A SECONDARY WAVE OF LOW PRESSURE DEVELOPS ALONG THE SLOW-
MOVING FRONT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...WSS/SMITH
SHORT TERM...MLM/ELLIS
LONG TERM...ELLIS
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
242 AM EDT TUE MAR 25 2014
.SYNOPSIS...A COMPLEX LOW PRESSURE SYSTEM WILL RAPIDLY INTENSIFY
WHILE TRACKING UP THE CAROLINA AND MIDDLE ATLANTIC COASTS THROUGH
TONIGHT. MODIFIED ARCTIC HIGH PRESSURE WILL FOLLOW BEHIND THE SYSTEM
FOR THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY NIGHT/...
AS OF 1010 PM MONDAY...
THROUGH MID-MORNING TUESDAY... REGIONAL SURFACE ANALYSIS THIS
EVENING SHOWS WEAK HIGH PRESSURE JUST EAST OF THE DELMARVA... AN
INVERTED TROUGH EXTENDING UP THE APPALACHIANS...AND A WEAK LOW
FORMING EAST OF DAYTONA. ALOFT... RAOBS SHOW WESTERLY FLOW OVER THE
SOUTHEAST US AND A SHORTWAVE TROUGH MOVING INTO THE MID MS RIVER
VALLEY REGION. THIS LEAD SHORTWAVE WILL HELP DRIVE THE DEVELOPING
SURFACE LOW NORTHEAST INTO THE ATLANTIC TONIGHT AND EARLY TUESDAY.
MEANWHILE...A 125KT UPPER JET DIVING THROUGH THE CENTRAL PLAINS WILL
BEGIN TO AMPLIFY THE UPPER LEVEL FLOW LATE TONIGHT...LEADING TO A
SECONDARY SURFACE LOW EAST OF CAPE HATTERAS BY TUESDAY EVENING.
UPSTREAM THIS EVENING...PRECIP ASSOCIATED WITH THE LEAD SHORTWAVE IS
DRYING UP...BY EXPECT PRECIP TO REDEVELOP FROM THE SOUTHERN
APPALACHIANS TO THE BLUE RIDGE BY AROUND 08Z AS THE UPPER TROUGH
AMPLIFIES AND DCVA/HEIGHT FALLS BEGIN TO INCREASE. TO THE
SOUTHEAST... PRECIP WILL ALSO BREAK OUT WITH SLOWLY STRENGTHENING
LOW LEVEL WARM ADVECTION AND CYCLOGENESIS OVER THE SOUTH CAROLINA
COASTAL AREA...THOUGH MOST OF THE CONVECTION ALLOWING MODELS NOW
KEEP PRECIP SOUTHEAST OF SAMPSON AND WAYNE COUNTIES THROUGH 12Z.
WITH THE AFOREMENTIONED AREAS OF FORCING NOT LINKING UP UNTIL
TUESDAY AFTERNOON AS THE SYSTEM BEGINS TO LIFT AWAY FROM THE AREA
AND DEEPEN...MODELS CONTINUE SHOW SHOW RELATIVELY LIGHT QPF AMOUNTS
AROUND ONE TENTH OF AN INCH IN THE NORTHWEST AND SOUTHEAST PORTIONS
OF THE CWA PRIOR TO 15Z.
REGARDING THE CHANCE OF SNOW IN THE NORTHWEST PIEDMONT...THE NAM AND
GFS FORECAST SOUNDINGS STILL SHOW SIGNIFICANTLY DIFFERENT BOUNDARY
LAYER MOISTURE...WITH THE NAM SATURATING MUCH MORE RAPIDLY THAN THE
GFS. THE LATEST RAP APPEARS TO BE SOMEWHERE IN BETWEEN. IN ANY
CASE...WETBULB PROFILES CONTINUE TO SUPPORT THE POTENTIAL FOR BURSTS
OF SNOW WITH HEAVIER PRECIP RATES...WITH THE BEST CHANCE BETWEEN 10Z
AND 14Z.. WITH NEAR SURFACE TEMPERATURES AT OR A LITTLE ABOVE
FREEZING...AND TOP SOIL TEMPS IN THE LOW-MID 40S...ANY SNOW THAT
OCCURS WILL LIKELY MELT ON IMPACT. THE EXCEPTION TO THIS WILL BE
"IF" A BURST OF MODERATE TO HEAVY SNOW WERE TO OCCUR...QUICKLY
COATING GRASSY AREAS AND THE TOPS OF CARS.
AS THE BULK OF THE PRECIP TRANSITIONS TOWARD EASTERN NC AND TEMPS
WARM A FEW DEGREES...ANY LINGERING PRECIP OVER THE NORTHWEST AND
NORTHERN PIEDMONT WILL BECOME ALL RAIN BY MIDDAY. -SMITH
TUESDAY AFTERNOON...THE NORTHERN STREAM S/W WILL TAKE ON A NEGATIVE
TILT AS IT CROSSES THE MID ATLANTIC STATES. THIS WILL LEAD TO SFC
CYCLOGENESIS OFF OF HATTERAS BY LATE TUESDAY WITH RAPID DEEPENING
TUESDAY NIGHT AS IT LIFTS TO THE N-NE. THIS MOVEMENT WILL TAKE THE
BULK OF THE PRECIP AWAY FROM CENTRAL NC BY EARLY TUESDAY
EVENING..WITH CLEARING SKIES DURING THE EVENING HOURS.
THE DEEPENING LOW COUPLED WITH ANOTHER CANADIAN HIGH OVER THE MID MS
VALLEY WILL CREATE BLUSTERY NW WINDS ACROSS CENTRAL NC LATE TUESDAY
THROUGH TUESDAY NIGHT. EXPECT WIND GUSTS 20-25 MPH WELL INTO THE
NIGHT. THIS WIND WILL ALSO USHER ANOTHER BATCH OF COOL DRIER AIR
INTO CENTRAL NC. THE WIND COUPLED WITH COLD AIR WILL RESULT IN WIND
CHILL VALUES IN THE UPPER TEENS TO AROUND 20 DEGREES LATE TUESDAY
NIGHT. MIN TEMPS MID 20S NW TO NEAR 30 SE. -WSS
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 240 AM TUESDAY...
UPPER TROF SHIFTS EAST AND THE COASTAL STORM LIFTS NORTHEAST QUICKLY
ON WEDNESDAY...WITH CLEAR SKIES AND THE PRESSURE GRADIENT RELAXING
AS THE MORNING PROGRESSES. COLD AIR ADVECTION WILL BE WELL
UNDERWAY...COMPLIMENTS OF SURFACE HIGH PRESSURE BUILDING IN FROM THE
WEST...WITH NORTHWEST WINDS 10 TO 15 MPH WITH GUSTS TO 25 MPH AROUND
DAYBREAK...WITH GUSTS DIMINISHING TO 15 MPH IN THE AFTERNOON. HIGHS
WILL BE IN THE MID 40S.
THE SURFACE HIGH WILL MOVE OVERHEAD WEDNESDAY NIGHT...PRODUCING
IDEAL RADIATIONAL CONDITIONS AND A COLDER OVERNIGHT PERIOD...
TEMPERATURE-WISE...WITH LOWS SOLIDLY IN THE MID 20S. OUTLYING AREAS
ARE APT TO SEE SOME LOW 20S READINGS AROUND SUNRISE. THESE LOW
TEMPERATURES WILL THREATEN CROPS THAT WERE PLANTED EARLY AS WELL AS
FRUIT TREES AND STRAWBERRIES THAT ARE IN BLOOM. ON THE POSITIVE
SIDE...THERE WILL BE NO APPRECIABLE WIND CHILL DUE TO THE CALM
WINDS. -MLM
THURSDAY: THURSDAY WILL START OUT WITH A STRONG 1035 MB SURFACE HIGH
PRESSURE CENTERED OVER COASTAL NC. WHILE THE DAY MIGHT START OUT
FAIRLY CLOUD FREE...EXPECT MID AND UPPER LEVEL CLOUDS TO QUICKLY
SHROUD MOST OF THE CWA BY LATE MORNING/EARLY AFTERNOON. DESPITE THE
CLOUD COVER...NO PRECIPITATION IS EXPECTED. WHILE GUIDANCE SUGGESTS
MAX TEMPERATURES IN THE UPPER 50S...THICKNESSES AND CLOUD COVER
SUGGEST COOLER TEMPS...FOR NOW WILL GO MID 50S NORTH TO UPPER 50S IN
THE SOUTH. -ELLIS
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 240 AM TUESDAY...
THURSDAY NIGHT THROUGH SATURDAY NIGHT: THE FIRST HALF OF THE LONG
TERM IS SETTING UP TO BE A FAIRLY WET PERIOD WITH THE FIRST ACT
BEGINNING WITH AN IN-SITU DAMMING EVENT AS THE 1035 MB SURFACE HIGH
MOVES OUT INTO THE WESTERN ATLANTIC. ISENTROPIC LIFT HIGHLIGHTED ON
THE 290 K SURFACE SUPPORTS AT LEAST SOME LOW LEVEL CLOUDS MOVING
INTO CENTRAL NC WITH PERHAPS EVEN SOME VERY LIGHT PRECIPITATION.
OVERNIGHT LOWS IN TEH LOW TO MID 40S.
ON FRIDAY SURFACE LOW PRESSURE WILL MOVE THROUGH THE GREAT LAKES
WITH AN ATTENDANT COLD FRONT STRETCHING SOUTHWESTWARD. EARLY IN THE
DAY...MOISTURE TRANSPORT AND CONVERGENCE WILL INCREASE SIGNIFICANTLY
THROUGH THE DAY ON FRIDAY WITH PRECIPITABLE WATER VALUES RISING
ABOVE AN INCH BY FRIDAY AFTERNOON 1.25 INCHES BY EVENING. THE MAIN
PRE-FRONTAL PRECIPITATION WILL HOLD BACK ACROSS THE MOUNTAINS FRIDAY
MORNING AND ANY PRECIPITATION OCCURRING ACROSS CENTRAL NC WOULD BE
LIGHT AND ASSOCIATED MORE WITH MOISTURE CONVERGENCE IN THE SOUTHERLY
RETURN FLOW. THAT WILL CHANGE AFTER 18Z HOWEVER...WHEN PRECIP
OVERSPREADS MUCH OF THE CWA. MODEL FORECAST SOUNDINGS ARE VERY WET
THROUGH THE COLUMN WITH SOME BUT VERY WEAK INSTABILITY. WHILE BULK
SHEAR WILL BE AROUND 40 KTS...THE WEAK CAPE VALUES LOOK TO ONLY
SUPPORT SHOWERS BUT CAN NOT RULE OUT A FEW THUNDERSTORMS IN THE
EXTREME SOUTHEAST. THERE IS SOME UNCERTAINTY AS TO COVERAGE AND QPF
AMOUNTS AT THIS TIME BUT WILL KEEP A COUPLE TENTHS OF AN INCH
POSSIBLE BY THE END OF THE EVENING ON FRIDAY. TEMPERATURES IN THE
LOW 60S NW TO UPPER 60S SE. THE FRONT WILL HAVE TROUBLE GETTING
THROUGH THE AREA ON FRIDAY NIGHT AND AT THIS POINT LOOKS LIKE
CENTRAL NC WILL REMAIN IN THE WARM SECTOR AT LEAST INTO SATURDAY
MORNING. LOWS UPPER 40S TO MIDDLE 50S.
SATURDAY WILL CONTINUE TO BE WET AS THE FRONT LINGERS NORTHWEST OF
THE AREA. THIS WONT LAST FOREVER THOUGH AS THE UPPER TROUGH BEGINS
TO DIG INTO THE MISSISSIPPI VALLEY AND WILL EVENTUALLY GIVE THE
SUPPORT NEEDED TO PUSH THE FRONT THROUGH AND THE SYSTEM OUT TO SEA.
THE DETAILS OF HOW THIS WILL EVOLVE THOUGH REMAIN IN QUESTION BUT
ARE NOW COMING INTO BETTER AGREEMENT. BOTH MODELS NOW DEVELOP A
SOUTHERN STREAM WAVE WEST OF THE MOUNTAINS AND MOVE NORTH OF THE
AREA THROUGH THE MID ATLANTIC...PUSHED OUT TO SEA BY THE UPPER
TROUGH WHERE IT WILL LINK UP WITH A WEAKER WAVE OF LOW PRESSURE
COMING OUT OF THE GULF OF MEXICO AND UP THE EAST COAST. AN UPPER LOW
MOVES ACROSS NC BUT DOES NOT REALLY PHASE WITH THE LOW COMING UP THE
COAST. SATURDAY WILL BE WET AND OVERCAST WITH HIGHS IN THE MID TO
UPPER 60S. FORECAST SOUNDINGS SHOW MUCH BETTER INSTABILITY ON
SATURDAY THAN FOR FRIDAY WITH AS MUCH AS 800 J/KG IN THE SOUTHEAST
WITH 35-40 KTS OF BULK SHEAR MAKING THUNDERSTORMS A MUCH BETTER
POSSIBILITY FROM THE TRIANGLE SOUTH AND EASTWARD THAN ON FRIDAY
AFTERNOON. WILL INCLUDE THE CHANCE FOR THUNDER IN THE FORECAST FOR
SATURDAY EVENING WITH FURTHER DETAILS TO BE IRONED OUT IN THE COMING
DAYS. THE FRONT WILL CROSS THE AREA SATURDAY NIGHT WITH WINDS
SHIFTING FROM SOUTHWESTERLY TO NORTHERLY WITH PRECIPITATION ENDING
AROUND DAYBREAK SUNDAY MORNING. LOWS SATURDAY NIGHT LOW TO MID 40S.
SUNDAY THROUGH MONDAY: MUCH DRIER FOR SUNDAY AND MONDAY AS SURFACE
HIGH PRESSURE EXTENDS ACROSS THE EASTERN SEABOARD WITH RIDGING
ALOFT. MONDAY WILL START OUT COOL ON THE EASTERN SIDE OF THE SURFACE
HIGH WITH NORTHERLY WINDS BUT THESE WILL BECOME VARIABLE BY MONDAY
AFTERNOON WITH HIGH PRESSURE MOVING MORE DIRECTLY OVERHEAD AND THEN
EAST OF THE AREA. HIGHS MONDAY IN THE MIDDLE 60S. LOWS IN THE UPPER
30S TO LOW 40S. A WARMING TREND FOR MONDAY AS SOUTHERLY RETURN FLOW
TAKES OVER AND THICKNESSES INCREASE BACK INTO THE 1350S. THIS SHOULD
SUPPORT HIGHS IN THE UPPER 60S TO NEAR 70 DEGREES.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 225 AM SATURDAY...
INITIALLY VFR CONDITIONS IN A DRY...EARLY SPRING ARCTIC AIR
MASS...WILL YIELD TO RAPIDLY DEVELOPING AND LOWERING MID LEVEL
CEILINGS AND VIRGA THIS MORNING...AS A POTENT UPPER LEVEL
DISTURBANCE PIVOTS ACROSS THE APPALACHIANS TOWARD CENTRAL NC. THIS
PRECIPITATION ALOFT WILL STEADILY SATURATE THE LOW LEVELS...SUCH
THAT CONDITIONS WILL BECOME AT LEAST MVFR ACROSS ALL OF CENTRAL
NC...AND LIKELY IFR AT TRIAD TERMINALS AND KRWI. THE PRECIPITATION
WILL FALL INITIALLY AS SNOW OR A SNOW/RAIN MIX AT TRIAD TERMINALS
BETWEEN 12-16Z...WITH RAIN ELSEWHERE. THE DEEP MOIST AXIS AND
ASSOCIATED MAIN BAND OF PRECIPITATION WILL THEN MOVE NORTHEAST OF
OUR AREA AND PROVIDE FOR A RETURN TO VFR CONDITIONS...WITH A
DEVELOPING GUSTY NORTHWESTERLY WIND AS THE BOUNDARY LAYER
DEEPENS...THIS AFTERNOON. A BAND OR TWO OF MOSTLY VFR RAIN SHOWERS
WILL THEN DEVELOP AND ACCOMPANY ANOTHER POTENT UPPER LEVEL
DISTURBANCE FORECAST TO PIVOT ACROSS NC BETWEEN 18-00Z. HAVE
ACCOUNTED FOR THIS POTENTIAL WITH A MENTION OF VICINITY SHOWERS IN
THE TAFS AT THIS TIME. TEMPO GROUPS MAY BE ADDED LATER FOR THIS
POTENTIAL AS TIMING AND LOCATION BECOME CLEARER. CLEARING AND
STRENGTHENING NW WINDS IN THE 12-18 KT RANGE WITH GUSTS TO 25-30
KTS...WILL DEVELOP THIS EVENING...AND CONTINUE OVERNIGHT.
OUTLOOK: THE BLUSTERY CONDITIONS WILL ABATE AROUND MIDDAY-EARLY
AFTERNOON WEDNESDAY. RETURN FLOW MOISTURE WILL RESULT IN MVFR-IFR
STRATUS...AND AREAS OF DRIZZLE OR LIGHT RAIN AT TRIAD TERMINALS...
LATE THU NIGHT-EARLY FRI. THIS LOW CLOUD COVER AND RAIN WILL THEN
SPREAD EAST ACROSS THE REMAINDER OF CENTRAL NC WITH THE APPROACH OF
A FRONTAL SYSTEM FROM THE WEST...WITH MVFR OR LOW VFR CEILINGS...ON
FRI. PERIODS OF SUB-VFR CONDITIONS MAY THEN CONTINUE THROUGH SAT
NIGHT...AS A SECONDARY WAVE OF LOW PRESSURE DEVELOPS ALONG THE SLOW-
MOVING FRONT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...WSS/SMITH
SHORT TERM...MLM/ELLIS
LONG TERM...ELLIS
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
226 AM EDT TUE MAR 25 2014
.SYNOPSIS...A COMPLEX LOW PRESSURE SYSTEM WILL RAPIDLY INTENSIFY
WHILE TRACKING UP THE CAROLINA AND MIDDLE ATLANTIC COASTS THROUGH
TONIGHT. MODIFIED ARCTIC HIGH PRESSURE WILL FOLLOW BEHIND THE SYSTEM
FOR THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY NIGHT/...
AS OF 1010 PM MONDAY...
THROUGH MID-MORNING TUESDAY... REGIONAL SURFACE ANALYSIS THIS
EVENING SHOWS WEAK HIGH PRESSURE JUST EAST OF THE DELMARVA... AN
INVERTED TROUGH EXTENDING UP THE APPALACHIANS...AND A WEAK LOW
FORMING EAST OF DAYTONA. ALOFT... RAOBS SHOW WESTERLY FLOW OVER THE
SOUTHEAST US AND A SHORTWAVE TROUGH MOVING INTO THE MID MS RIVER
VALLEY REGION. THIS LEAD SHORTWAVE WILL HELP DRIVE THE DEVELOPING
SURFACE LOW NORTHEAST INTO THE ATLANTIC TONIGHT AND EARLY TUESDAY.
MEANWHILE...A 125KT UPPER JET DIVING THROUGH THE CENTRAL PLAINS WILL
BEGIN TO AMPLIFY THE UPPER LEVEL FLOW LATE TONIGHT...LEADING TO A
SECONDARY SURFACE LOW EAST OF CAPE HATTERAS BY TUESDAY EVENING.
UPSTREAM THIS EVENING...PRECIP ASSOCIATED WITH THE LEAD SHORTWAVE IS
DRYING UP...BY EXPECT PRECIP TO REDEVELOP FROM THE SOUTHERN
APPALACHIANS TO THE BLUE RIDGE BY AROUND 08Z AS THE UPPER TROUGH
AMPLIFIES AND DCVA/HEIGHT FALLS BEGIN TO INCREASE. TO THE
SOUTHEAST... PRECIP WILL ALSO BREAK OUT WITH SLOWLY STRENGTHENING
LOW LEVEL WARM ADVECTION AND CYCLOGENESIS OVER THE SOUTH CAROLINA
COASTAL AREA...THOUGH MOST OF THE CONVECTION ALLOWING MODELS NOW
KEEP PRECIP SOUTHEAST OF SAMPSON AND WAYNE COUNTIES THROUGH 12Z.
WITH THE AFOREMENTIONED AREAS OF FORCING NOT LINKING UP UNTIL
TUESDAY AFTERNOON AS THE SYSTEM BEGINS TO LIFT AWAY FROM THE AREA
AND DEEPEN...MODELS CONTINUE SHOW SHOW RELATIVELY LIGHT QPF AMOUNTS
AROUND ONE TENTH OF AN INCH IN THE NORTHWEST AND SOUTHEAST PORTIONS
OF THE CWA PRIOR TO 15Z.
REGARDING THE CHANCE OF SNOW IN THE NORTHWEST PIEDMONT...THE NAM AND
GFS FORECAST SOUNDINGS STILL SHOW SIGNIFICANTLY DIFFERENT BOUNDARY
LAYER MOISTURE...WITH THE NAM SATURATING MUCH MORE RAPIDLY THAN THE
GFS. THE LATEST RAP APPEARS TO BE SOMEWHERE IN BETWEEN. IN ANY
CASE...WETBULB PROFILES CONTINUE TO SUPPORT THE POTENTIAL FOR BURSTS
OF SNOW WITH HEAVIER PRECIP RATES...WITH THE BEST CHANCE BETWEEN 10Z
AND 14Z.. WITH NEAR SURFACE TEMPERATURES AT OR A LITTLE ABOVE
FREEZING...AND TOP SOIL TEMPS IN THE LOW-MID 40S...ANY SNOW THAT
OCCURS WILL LIKELY MELT ON IMPACT. THE EXCEPTION TO THIS WILL BE
"IF" A BURST OF MODERATE TO HEAVY SNOW WERE TO OCCUR...QUICKLY
COATING GRASSY AREAS AND THE TOPS OF CARS.
AS THE BULK OF THE PRECIP TRANSITIONS TOWARD EASTERN NC AND TEMPS
WARM A FEW DEGREES...ANY LINGERING PRECIP OVER THE NORTHWEST AND
NORTHERN PIEDMONT WILL BECOME ALL RAIN BY MIDDAY. -SMITH
TUESDAY AFTERNOON...THE NORTHERN STREAM S/W WILL TAKE ON A NEGATIVE
TILT AS IT CROSSES THE MID ATLANTIC STATES. THIS WILL LEAD TO SFC
CYCLOGENESIS OFF OF HATTERAS BY LATE TUESDAY WITH RAPID DEEPENING
TUESDAY NIGHT AS IT LIFTS TO THE N-NE. THIS MOVEMENT WILL TAKE THE
BULK OF THE PRECIP AWAY FROM CENTRAL NC BY EARLY TUESDAY
EVENING..WITH CLEARING SKIES DURING THE EVENING HOURS.
THE DEEPENING LOW COUPLED WITH ANOTHER CANADIAN HIGH OVER THE MID MS
VALLEY WILL CREATE BLUSTERY NW WINDS ACROSS CENTRAL NC LATE TUESDAY
THROUGH TUESDAY NIGHT. EXPECT WIND GUSTS 20-25 MPH WELL INTO THE
NIGHT. THIS WIND WILL ALSO USHER ANOTHER BATCH OF COOL DRIER AIR
INTO CENTRAL NC. THE WIND COUPLED WITH COLD AIR WILL RESULT IN WIND
CHILL VALUES IN THE UPPER TEENS TO AROUND 20 DEGREES LATE TUESDAY
NIGHT. MIN TEMPS MID 20S NW TO NEAR 30 SE. -WSS
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 230 PM MONDAY...
UPPER TROF SHIFTS EAST AND THE COASTAL STORM LIFTS NORTHEAST QUICKLY
ON WEDNESDAY...WITH CLEAR SKIES AND THE PRESSURE GRADIENT RELAXING
AS THE MORNING PROGRESSES. COLD AIR ADVECTION WILL BE WELL
UNDERWAY...COMPLIMENTS OF SURFACE HIGH PRESSURE BUILDING IN FROM THE
WEST...WITH NORTHWEST WINDS 10 TO 15 MPH WITH GUSTS TO 25 MPH AROUND
DAYBREAK...WITH GUSTS DIMINISHING TO 15 MPH IN THE AFTERNOON. HIGHS
WILL BE IN THE MID 40S.
THE SURFACE HIGH WILL MOVE OVERHEAD WEDNESDAY NIGHT...PRODUCING
IDEAL RADIATIONAL CONDITIONS AND A COLDER OVERNIGHT PERIOD...
TEMPERATURE-WISE...WITH LOWS SOLIDLY IN THE MID 20S. OUTLYING AREAS
ARE APT TO SEE SOME LOW 20S READINGS AROUND SUNRISE. THESE LOW
TEMPERATURES WILL THREATEN CROPS THAT WERE PLANTED EARLY AS WELL AS
FRUIT TREES AND STRAWBERRIES THAT ARE IN BLOOM. ON THE POSITIVE
SIDE...THERE WILL BE NO APPRECIABLE WIND CHILL DUE TO THE CALM WINDS.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 230 PM MONDAY...
SOME WELCOME MODERATION IN TEMPERATURES IS ON TAP AS WE HEAD INTO
LATE WEEK AS THE SURFACE HIGH PRESSURE EDGES OFFSHORE AND A LOW
AMPLITUDE SHORT WAVE RIDGE TRANSLATES ACROSS THE AREA THURSDAY. THE
RESULTING SOUTHERLY RETURN FLOW AND SUNSHINE WILL ALLOW HIGHS TO
REACH THE MID TO UPPER 50S.
LOW LEVEL MOISTURE WILL BE RISING QUICKLY THURSDAY NIGHT AS DEW
POINTS CLIMB THROUGH THE 30S OVERNIGHT. THIS WILL RESULT IN
ISENTROPIC LIFT...WITH OVERCAST SKIES AND POSSIBLY SOME LIGHT RAIN
IN THE WEST BY FRIDAY MORNING. MINS WILL BE CORRESPONDINGLY MILDER
DUE TO THE SOUTHERLY FLOW AND DEVELOPING LOW CLOUDINESS...WITH MINS
FROM 40 TO 45.
UP TO THIS POINT THE MODELS HAVE BEEN IN RELATIVE AGREEMENT...
ESPECIALLY IN THE SENSIBLE WEATHER IMPACTS OVER CENTRAL NC THROUGH
FRIDAY...WITH BOTH ECM AND GFS DEPICTING A SURFACE LOW PRESSURE AREA
LIFTING INTO THE GREAT LAKES THURSDAY NIGHT WITH THE TRAILING COLD
FRONT EDGING EAST TOWARDS THE AREA FRIDAY. GFS IS HOLDING ONTO THE
IDEA OF DEVELOPING A TRAILING SOUTHERN STREAM SHORT WAVE INTO A
SECOND LOW PRESSURE AREA WHICH TRAILS THE INITIAL LOW
NORTHEAST...AND DELAYING THE FRONTAL PASSAGE UNTIL SATURDAY NIGHT.
MEANWHILE...THE ECM MAINTAINS A PROGRESSIVE SYSTEM WITH A CLEANER
SURFACE COLD FRONTAL PASSAGE FRIDAY NIGHT OR EARLY SATURDAY.
ONGOING FORECAST TRENDS ARE BASED ON THE FASTER ECM SOLUTION AND
WILL MAINTAIN THIS TREND PENDING A CLEARER SOLUTION HOPEFULLY TO
BECOME EVIDENT IN SUBSEQUENT RUNS. THUS WILL HAVE HIGH CHANCE POPS
FRIDAY NIGHT AND SATURDAY...WITH DRYING SATURDAY NIGHT. HIGHS FRIDAY
SHOULD BE AFFECTED BY THE IN-SITU EFFECTS OF THE ISENTROPICALLY
INDUCED LIGHT RAIN THURSDAY NIGHT...AND WILL UNDERCUT GUIDANCE BY
ABOUT 5 DEGREES IN THE CLIMATOLOGICALLY FAVORED AREA...GIVING US
NEAR 60 NORTHWEST TO 70 SOUTHEAST. MILD TEMPS IN THE WARM SECTOR
FRIDAY NIGHT...50 TO 55...AND SATURDAY SHOULD BE MILD AS WELL...MID
TO UPPER 60S...WITH POST FRONTAL COLD AIR ADVECTION DELAYED UNTIL
SATURDAY NIGHT...EVEN ON THE FASTER ECM...WITH MINS SUNDAY MORNING
WITHIN A COUPLE OF DEGREES EITHER SIDE OF 40. ZONAL FLOW = HIGH AND
DRY FOR DAYS 6 AND 7...WITH SUNDAYS HIGHS A BIT BELOW NORMAL...LOW
TO MID 60S...WARMING TO THE UPPER 60S MONDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 225 AM SATURDAY...
INITIALLY VFR CONDITIONS IN A DRY...EARLY SPRING ARCTIC AIR
MASS...WILL YIELD TO RAPIDLY DEVELOPING AND LOWERING MID LEVEL
CEILINGS AND VIRGA THIS MORNING...AS A POTENT UPPER LEVEL
DISTURBANCE PIVOTS ACROSS THE APPALACHIANS TOWARD CENTRAL NC. THIS
PRECIPITATION ALOFT WILL STEADILY SATURATE THE LOW LEVELS...SUCH
THAT CONDITIONS WILL BECOME AT LEAST MVFR ACROSS ALL OF CENTRAL
NC...AND LIKELY IFR AT TRIAD TERMINALS AND KRWI. THE PRECIPITATION
WILL FALL INITIALLY AS SNOW OR A SNOW/RAIN MIX AT TRIAD TERMINALS
BETWEEN 12-16Z...WITH RAIN ELSEWHERE. THE DEEP MOIST AXIS AND
ASSOCIATED MAIN BAND OF PRECIPITATION WILL THEN MOVE NORTHEAST OF
OUR AREA AND PROVIDE FOR A RETURN TO VFR CONDITIONS...WITH A
DEVELOPING GUSTY NORTHWESTERLY WIND AS THE BOUNDARY LAYER
DEEPENS...THIS AFTERNOON. A BAND OR TWO OF MOSTLY VFR RAIN SHOWERS
WILL THEN DEVELOP AND ACCOMPANY ANOTHER POTENT UPPER LEVEL
DISTURBANCE FORECAST TO PIVOT ACROSS NC BETWEEN 18-00Z. HAVE
ACCOUNTED FOR THIS POTENTIAL WITH A MENTION OF VICINITY SHOWERS IN
THE TAFS AT THIS TIME. TEMPO GROUPS MAY BE ADDED LATER FOR THIS
POTENTIAL AS TIMING AND LOCATION BECOME CLEARER. CLEARING AND
STRENGTHENING NW WINDS IN THE 12-18 KT RANGE WITH GUSTS TO 25-30
KTS...WILL DEVELOP THIS EVENING...AND CONTINUE OVERNIGHT.
OUTLOOK: THE BLUSTERY CONDITIONS WILL ABATE AROUND MIDDAY-EARLY
AFTERNOON WEDNESDAY. RETURN FLOW MOISTURE WILL RESULT IN MVFR-IFR
STRATUS...AND AREAS OF DRIZZLE OR LIGHT RAIN AT TRIAD TERMINALS...
LATE THU NIGHT-EARLY FRI. THIS LOW CLOUD COVER AND RAIN WILL THEN
SPREAD EAST ACROSS THE REMAINDER OF CENTRAL NC WITH THE APPROACH OF
A FRONTAL SYSTEM FROM THE WEST...WITH MVFR OR LOW VFR CEILINGS...ON
FRI. PERIODS OF SUB-VFR CONDITIONS MAY THEN CONTINUE THROUGH SAT
NIGHT...AS A SECONDARY WAVE OF LOW PRESSURE DEVELOPS ALONG THE SLOW-
MOVING FRONT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...WSS/SMITH
SHORT TERM...MLM
LONG TERM...MLM
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
138 AM EDT TUE MAR 25 2014
.SYNOPSIS...
A CHILLY RAIN WILL OVERSPREAD THE AREA TODAY AS DEEPENING LOW
PRESSURE OFFSHORE TRACKS NORTHEAST OFF OUR COAST. THE RAIN WILL
TAPER OFF LATE TONIGHT FOLLOWED BY WINDY AND COLDER CONDITIONS
AS THE LOW DEEPENS AND CANADIAN HIGH PRESSURE BUILDS FROM THE
WEST. NEAR TO BELOW FREEZING TEMPERATURES ARE EXPECTED EARLY ON
WEDNESDAY AND AGAIN THURSDAY. A WARMING TREND WILL PREVAIL LATE
IN THE WEEK INTO NEXT WEEKEND...WITH A WEAK COLD FRONT POSSIBLY
CROSSING THE AREA EARLY ON SUNDAY. FAIR AND DRY EARLY NEXT WEEK
AS HIGH PRESSURE MOVES OVER THE AREA.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 130 AM TUESDAY...LOW PRESSURE WILL CONSOLIDATE ALONG THE
FLORIDA PENINSULA TONIGHT...EMERGING OFF THE EAST COAST OF FL BY
SUNRISE. NO APPRECIABLE INTENSIFICATION IS EXPECTED UNTIL THE
UPPER TROUGH AND SIGNIFICANT SHORTWAVE ENERGY REACHES THE SURFACE
FEATURE LATE TUE AND TUE NIGHT AND BY THAT TIME...THE CENTER OF
THE LOW WILL BE JUST MOVING N OF OUR LATITUDE. THICKER CLOUD COVER
RESIDES TO OUR S THIS EVE WITH MAINLY THIN CIRRUS ACROSS THE
EASTERN CAROLINAS. THIS THICKER CLOUD COVER WILL BEGIN TO ADVANCE
NORTHWARD... ESPECIALLY AFTER MIDNIGHT. EARLY THIS EVE...THE
NEAREST WET WEATHER IN THE FORM OF SHOWERS AND THUNDERSTORMS WERE
DOWN ACROSS THE GULF OF MEXICO AND FLORIDA PENINSULA. HOWEVER...AS
THE LOW CENTER CONSOLIDATES E OF FL...WE DO EXPECT PRECIPITATION
TO BEGIN DEVELOPING OFF THE SOUTHEAST COAST WITH A NORTHWARD
SPREAD INTO AT LEAST PORTIONS OF THE EASTERN CAROLINAS TOWARD
MORNING. WILL INCLUDE THE HIGHEST POPS...UP TO
CATEGORICAL...ACROSS OUR SOUTHERN ZONES OVERNIGHT WITH MUCH LOWER
POPS AS YOU MOVE NORTH. HOWEVER...POPS EVEN ACROSS THE NORTHERN
PORTIONS OF THE FORECAST AREA WILL TREND MUCH HIGHER TUE MORNING.
THE CHARACTER OF THE PRECIPITATION WILL BEST BE DESCRIBED AS A
CHILLY RAIN.
LOWS WILL BE REACHED PRIOR TO THE ARRIVAL OF THE THICKEST CLOUD
COVER AND ONSET OF STRONGER ONSHORE PUSH. WE EXPECT MOST AREAS WILL
FLAT LINE AROUND THE MIDNIGHT HOUR AND THEN HOLD STEADY IF NOT RISE
A FEW DEGREES AS THE MOISTURE CONTENT OF THE AIR BEGINS TO
SIGNIFICANTLY INCREASE. WE WILL CONTINUE TO CAP LOWS IN THE MID AND
UPPER 30S AND WE ARE NOT EXPECTING A FREEZE TONIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM MONDAY...LIGHT RAIN LIKELY ONGOING AT THE START OF THE
PERIOD...THE MAIN QUESTION AS TO THE INLAND EXTENT. LOW PRESSURE
WELL OFF THE COAST TO BE MOVING TO THE NORTHEAST AND JUST ON THE
BEGINNING OF A DEEPENING TREND. EARLY IN THE DAY THE AREA WILL STILL
BE IN SOME WARM AIR ADVECTION FOR LOW LEVEL ASCENT BUT INLAND
LOCATIONS WILL NOT HAVE AS DEEP OF A MOISTURE PROFILE...YET MAY
EXPERIENCE STRONGER MID LEVEL SUPPORT AS INITIAL VORT MOVES BY.
SIMILARLY LATER IN THE DAY THE DEEPEST MOISTURE WILL REMAIN ALONG
COAST/OFFSHORE WHILE EVEN STRONGER HEIGHT FALLS AND PVA IMPINGE UPON
WESTERN ZONES. OVERALL RAINFALL AMOUNTS LOOK TO BE LOW...GENERALLY A
QUARTER OF AN INCH OR LESS...HIGHEST EAST. LATER IN THE EVENING ALL
SIGNS POINT TO RAPID DRYING...THE MAIN VORT CENTER OF THE MID LEVEL
HAS CROSSED...THE LOW ACCELERATES TO THE NE AND BEGINS TO BOMB...AND
LOW LEVEL THERMAL ADVECTION TURNS COLD. THE RAPIDLY DEEPENING AND
GROWING LOW WILL KEEP A MODERATE GRADIENT UP ALL NIGHT LOCALLY
ADDING A CHILL TO THE ALREADY UNSEASONABLY COLD TEMPERATURES. IT HAS
ALSO CAST JUST ENOUGH UNCERTAINTY AS TO WHICH LOCATIONS GET BELOW
FREEZING AND FOR HOW LONG. AFTER COLLAB WITH SURROUNDING WFO`S HAVE
OPTED TO HOLD OFF ON A FREEZE WATCH AT THIS TIME. WITH THE CENTER OF
THE HIGH DRAWING IN ON WEDNESDAY WE WILL SEE AN ABATING TREND IN THE
CHILLY WIND BUT A SHALLOW MIXED BOUNDARY LAYER WILL PREVENT MUCH OF
THE TEMPERATURE RECOVERY ABOVE FROM REACHING THE SURFACE...AND SAID
TEMP RECOVERY LOOKS A LITTLE TOO BRISK ANYWAY. LOOKS LIKE MOST
PLACES WILL STRUGGLE TO HIT A HIGH OF ABOUT 50...WITH A FEW DEGREES
ADDED TO FAR SRN ZONES. WITH SUCH A COLD AIRMASS IN PLACE AND LIGHT
OR EVEN CALM WINDS WEDNESDAY NIGHT HAS LONG BEEN THE ONE OUR
AGRICULTURAL INTERESTS CONTINUE TO DREAD. LOWS WILL READILY DIP
BLOW FREEZING FOR ALL BUT THE BEACHES...AND COOL FASTER THAN TUESDAY
NIGHT DUE TO THE LIGHT WINDS. NRN ZONES WHERE THE MOST ACTIVE
GROWING IS ALREADY OCCURRING SHOULD GET INTO THE MID 20S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...UNSETTLED WEATHER EXPECTED LATE IN THE PERIOD
AHEAD OF A LATE WEEK COLD FRONT AND POTENTIAL SOUTHERN STREAM
SHORTWAVE. PERIOD WILL BEGIN WITH MODIFYING HIGH PRESSURE SHIFTING
OFFSHORE AND DEVELOPING RETURN FLOW. TEMPS ONCE AGAIN RUN BELOW
CLIMO THU BUT MUCH WARMER THAN PREVIOUS DAYS. SIGNIFICANT DRY AIR
WILL EXIST AND PRECIP IS NOT EXPECTED THROUGH THU NIGHT. WARM
ADVECTION CONTINUES FRI PUSHING TEMPS NEAR TO ABOVE CLIMO AND
INCREASES MOISTURE. SEA BREEZE CONVECTION AND DIURNAL INSTABILITY
SHOWERS ARE EXPECTED AND HAVE HELD ONTO INHERITED LOW CHC POP. POP
REMAINS ELEVATED FRI NIGHT INTO SAT WITH COLD FRONT EXPECTED TO
CROSS THE AREA. SPEED OF THE FRONT WILL IN PART DEPEND ON A WEAKER
TRAILING SHORTWAVE MOVING INTO THE TN VALLEY EARLY SAT. MEDIUM RANGE
GUIDANCE AND THE ENSEMBLES ARE SPLIT ON THE TIMING/STRENGTH OF THE
WAVE WHICH COULD LEAD TO POP LINGERING WELL INTO SAT AFTERNOON
ACROSS EASTERN AREAS.
MUCH DRIER AIR MASS BUILDS IN FOR THE START OF NEXT WEEK WITH COLD
ADVECTION DELAYED UNTIL SUN. COLD ADVECTION WILL BE ON THE WEAK SIDE
WITH TEMPS ENDING UP BELOW CLIMO SUN AND MON. DEEP DRY AIR AND
NORTHERLY FLOW WILL HELP KEEP REGION DRY FOR THE START OF NEXT WEEK.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 06Z...MID LEVEL CIGS ARE SPREADING ACROSS THE CWA TONIGHT AS
SURFACE LOW PRESSURE ORGANIZES OFF THE FLORIDA COAST. EARLIER
FORECAST APPEARS ON TRACK AS THE LATEST HRRR RUNS INDICATE RAIN WILL
SPREAD UP THE COAST FROM SOUTH TO NORTH EARLY THIS MORNING. HAVE
NUDGED THE TIMING OF PCPN BACK A BIT WITH THIS TAF ISSUANCE...BUT
STILL EXPECT KMYR/KCRE TO SEE -RA BEFORE 12Z. WITH THE OFFSHORE
TRACK OF THE LOW...EXPECT PCPN AND MVFR CIGS TO BE FOCUSED ALONG THE
COAST. HAVE INCLUDED TEMPO MVFR FOR THE COASTAL TERMS IN THE LATE
MORNING/EARLY AFTERNOON AS RAIN WILL HELP TO LOWER CIGS. E-NE WINDS
5-10 KTS THIS MORNING WILL BECOME NORTHWEST AFTER 18Z AS THE LOW
PROGRESSES FURTHER UP THE COAST. COULD SEE NORTHWEST WIND GUSTS OF
15-20 KTS BY LATE AFTERNOON/EARLY EVENING ON THE BACKSIDE OF THE
LOW. CONDITIONS WILL IMPROVE TO VFR FROM SOUTHWEST TO NORTHEAST THIS
EVENING...BECOMING VFR AT ALL SITES SHORTLY AFTER 00Z WEDNESDAY.
EXTENDED OUTLOOK...VFR ON WEDNESDAY AND THURSDAY. CHANCE OF SHOWERS
WITH TEMPO MVFR CONDITIONS POSSIBLE ON FRIDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 900 PM MONDAY...AS LOW PRESSURE CONSOLIDATES TO THE SOUTH OF
THE AREA OVERNIGHT AND HIGH PRESSURE RETREATS NORTHWARD AND
OFFSHORE...WE WILL BEGIN TO SEE THE PRESSURE GRADIENT TIGHTEN AND
THIS TREND WILL INCREASE IN BOTH RATE AND MAGNITUDE TUE AND TUE
NIGHT AS LOW PRESSURE STRENGTHENS...MOST RAPIDLY AS IT PUSHES N OF
OUR LATITUDE TUE NIGHT. WINDS AND SEAS WILL BE ON THE UPTREND AFTER
MIDNIGHT WITH SMALL CRAFT ADVISORY CONDITIONS DEVELOPING DURING TUE.
THE WIND DIRECTION TONIGHT WILL BE NE TO ENE...UP TO 15 TO 20 KT.
SEAS WILL BE 3 TO 4 FT...INCREASING UP TO 5 FT ACROSS THE OUTER
WATERS TOWARD MORNING.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM MONDAY...WILL RAISE SMALL CRAFT FOR NORTHERN ZONES
STARTING 12Z TUESDAY. WINDS WILL STILL BE ON THE RISE BUT THERE WILL
BE JUST ENOUGH SWELL ENERGY TO PUSH SEAS TO 4 TO 6 FT BY THE START
OF THE PERIOD. FROM THERE WIND AND SEAS WILL ONLY INCREASE BUT WAVE
SHADOWING WILL PROBABLY PRECLUDE ADVISORY FOR BRUNSWICK WATERS.
ADVISORY CONDITIONS MAY MATERIALIZE FURTHER SOUTH IN THE FORM OF
WIND AND SEAS FOR GTWON AND JUST WINDS FOR BRUNSWICK DUE TO WAVE
SHADOWING. THIS WILL BE DELAYED UNTIL TUESDAY NIGHT OR EVEN
WEDNESDAY SO HAVE HELD OFF ON FLAGS THERE FOR NOW. THIS WILL BE IN
RESPONSE TO THE LOW PRESSURE THAT PASSES BY ON TUESDAY...WHICH THEN
INTENSIFIES RAPIDLY AND GROWS IN SIZE ON WEDNESDAY AS IT
ACCELERATES TO THE NORTHEAST.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 300 PM MONDAY...LIGHT NORTHEAST FLOW WILL GRADUALLY VEER TO
SOUTHEAST THU AS HIGH PRESSURE SHIFTS OFF THE COAST. GRADIENT STARTS
TO BECOME MORE DEFINED THU NIGHT AND FRI WITH WINDS BECOMING
SOUTHERLY AND INCREASING TO A SOLID 15 KT THU NIGHT AND 15 TO 20 KT
FRI. COLD FRONT CROSSES THE WATERS EARLY SAT BUT LAGGING COLD
ADVECTION WILL KEEP LOW LEVEL FLOW SOUTHERLY. WEAK GRADIENT BEHIND
THE FRONT INITIALLY RESULTS IN WINDS 10 KT OR LESS INTO SAT
AFTERNOON. ONSET OF COLD ADVECTION LATE IN THE PERIOD KICKS
NORTHERLY FLOW TO A SOLID 20 KT BY THE END OF THE PERIOD. SEAS 2 TO
3 FT THU BUILD TO 3 TO 5 FT BY MIDDAY FRI AND 4 TO 6 FT FRI
AFTERNOON. SEAS DROP TO 3 TO 4 FT SAT IN RESPONSE TO THE REDUCTION
IN WIND SPEEDS. INCREASING NORTHERLY FLOW SAT NIGHT WILL BUILD SEAS
TO 3 TO 5 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 8 AM EDT
WEDNESDAY FOR AMZ250-252.
&&
$$
NEAR TERM...MJC/RJD
SHORT TERM...MBB
LONG TERM...III
AVIATION...MJC/BJR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1110 PM CDT MON MAR 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 318 PM CDT MON MAR 24 2014
LATEST WATER VAPOR SATELLITE IMAGERY INDICATING SEVERAL SHORTWAVE
TROUGHS EMBEDDED IN NORTHERLY FLOW ALOFT OVER THE NORTHERN PLAINS
AND CENTRAL CANADA. LATEST MOSAIC RADAR SHOWS NUMEROUS SNOW
SHOWERS ACROSS FORECAST AREA BACK INTO CENTRAL MINNESOTA. THIS IS
IN RESPONSE TO STEEP LAPSE RATE UP TO 750MB PER LATEST RAP BUFKIT
SOUNDINGS.
TONIGHT...ANOTHER IMPULSE EMBEDDED IN THE NORTHERLY FLOW ALOFT
WILL MOVE OVER THE FORECAST AREA AND GREAT LAKES REGION. THE
24.12Z GFS/NAM AND 24.18Z BUFKIT SOUNDINGS SUGGEST STEEP LAPSE
RATES UP TO 850MB...500-300MB POTENTIAL VORTICITY ADVECTION AND
FORCING ABOVE 700MB IN ASSOCIATION WITH THE IMPULSE. THIS WILL
CONTINUE THE ISOLATED TO SCATTERED SNOW SHOWERS OVER FORECAST
AREA TO AROUND 09Z TUESDAY. HAVE INTRODUCE THIS TREND INTO THE
FORECAST.
BEHIND SHORTWAVE TROUGH...COLDER AIR WILL FILTER INTO THE AREA
TUESDAY...WITH 925MB TEMPERATURES FALLING INTO THE MINUS TEENS
DEGREES CELSIUS BY 18Z TUESDAY. TEMPERATURES WILL BE WELL BELOW
NORMAL AND HIGH TEMPERATURES EXPECTED TO CLIMB INTO THE TEENS TO
MIDDLE 20S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 318 PM CDT MON MAR 24 2014
FOCUS TURNS TO WEDNESDAY INTO THURSDAY NIGHT...AS NEXT SYSTEM
AFFECTS THE UPPER MIDWEST AND GREAT LAKES REGION. THE 24.12Z NAM
AND GFS CONTINUE TO BE THE MOST PROGRESSIVE AND FARTHER NORTH
PLACEMENT WITH THIS SYSTEM COMPARED TO THE 24.12Z ECMWF AND GEM.
THE 24.12Z MODELS ARE IN AGREEMENT DECENT WARM AIR ADVECTS INTO
THE AREA OUT AHEAD OF THE SYSTEM AND WRAPS INTO THE SYSTEM. THIS
WOULD ALLOW FOR MUCH OF THE PRECIPITATION TO FALL AS RAIN ACROSS
THE FORECAST AREA WEDNESDAY NIGHT INTO THURSDAY. THIS IS EVIDENT
WITH THE 24.12Z GFS/NAM BUFKIT SOUNDINGS SHOWING TEMPERATURES
ABOVE ZERO UP TO 850MB ACROSS MUCH OF THE FORECAST AREA AFTER 06Z
THURSDAY INTO THURSDAY AFTERNOON. THE 24.12Z MODELS INDICATE
SURFACE FRONT PASSAGE LATE THURSDAY AFTERNOON INTO THURSDAY NIGHT
ACROSS FORECAST AREA. THE PRECIPITATION SHOULD TRANSITION TO ALL
SNOW FROM WEST TO EAST ACROSS FORECAST AREA THURSDAY EVENING INTO
THURSDAY NIGHT. HOWEVER...WITH INCONSISTENCIES OF TIMING AND
PLACEMENT OF SYSTEM BY ALL THE MODELS WEDNESDAY NIGHT INTO
THURSDAY NIGHT...CONFIDENCE IN FORECAST AT THIS TIME PERIOD IS
LOW.
FRIDAY INTO SUNDAY MAIN FORECAST CONCERNS ARE TEMPERATURES ACROSS
THE FORECAST AREA. THE 24.12Z GFS/ECMWF BOTH ARE IN AGREEMENT IN
BREAKING DOWN UPPER LEVEL TROUGH OVER THE GREAT LAKES REGION AND
BUILDING SHORTWAVE RIDGE OVER THE NORTHERN PLAINS AND UPPER
MIDWEST THIS WEEKEND. THE MODELS SUGGEST 925MB TEMPERATURES
WARMING TO AROUND PLUS 10 DEGREES CELSIUS BY 00Z SUNDAY OVER
FORECAST AREA. THIS SHOULD ALLOW TEMPERATURES TO BE NEAR OR ABOVE
NORMAL SUNDAY. THEN...THE 14.12Z GFS/ECMWF BEGIN TO DIVERGE EARLY
NEXT WEEK WITH SHORTWAVE TROUGH EMBEDDED IN WEST TO EAST ZONAL
FLOW ALOFT. THE 24.12Z ECMWF MUCH MORE PROGRESSIVE AND STRONGER
WITH SHORTWAVE TROUGH AND INDICATES PRECIPITATION TO OVERSPREAD
THE FORECAST AREA MONDAY. THE 24.12Z GFS IS SLIGHTLY SLOWER AND
WEAKER WITH SHORTWAVE TROUGH AND DELAYS ANY PRECIPITATION INTO THE
FORECAST AREA BY 18Z MONDAY. AT THIS TIME...WILL INTRODUCE PRECIPITATION
CHANCES ACROSS FORECAST AREA SUNDAY NIGHT AND MONDAY.
PRECIPITATION SHOULD REMAIN AS ALL RAIN AS TEMPERATURES REMAIN
WELL ABOVE ZERO DEGREES CELSIUS IN THE NEAR SURFACE BOUNDARY LAYER
TO 800MB PER BUFKIT SOUNDINGS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1110 PM CDT MON MAR 24 2014
NEXT SHORTWAVE TROUGH SINKING SOUTHWARD ACROSS MN AT LATE
EVENING...AND WAS TRIGGERING A FEW -SHSN PER LATEST 88-D RADAR
RETURNS. NO VSBY RESTRICTIONS INDICATED VIA SFC OBS AS OF YET...BUT
BELIEVE THEY WOULD BE CAPABLE OF MVFR VSBYS FOR A BRIEF PERIOD.
RAP13/NAM12 SUGGEST THESE SHOWERS WILL DIMINISH BEFORE REACHING
KRST/KLSE. GIVEN THEIR SCATTERED NATURE AND THE MODEL TRENDS...WILL
LEAVE THEM OUT OF FORECAST FOR NOW.
SATELLITE IMAGERY INDICATED SCT SKIES FOR THE MOST PART...WITH
POCKETS OF BKN. CIGS WERE GENERALLY VFR THOUGH. EXPECT SCT-BKN
CONDITIONS FOR TUE...WITH SC/CU DEVELOPMENT IN THE LATE MORNING. A
CHANCE FOR 2.5 KFT BKN CIGS...BUT CONFIDENCE NOT HIGH ENOUGH TO ADD
TO THE FORECAST AS THIS MOMENT. WINDS WILL STAY FROM THE
NORTHWEST...GENERALLY NEAR OR ABOVE 10 KTS FOR MUCH OF THE TAF
PERIOD.
&&
.HYDROLOGY...
ISSUED AT 318 PM CDT MON MAR 24 2014
COLDER AIR IS HELPING WITH SNOW MELT AND ASSOCIATED RUNOFF INTO
AREA RIVERS AND STREAMS. WARMER TEMPERATURES ARE EXPECTED
WEDNESDAY INTO THURSDAY...AND THE THREAT FOR PRECIPITATION. DURING
THIS TIME PERIOD WILL HAVE TO MONITOR THE RIVER LEVELS CLOSELY
FOR RISES AND POSSIBLE FLOODING IF ENOUGH RAIN FALLS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM....DTJ
AVIATION.....RIECK
HYDROLOGY....DTJ
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
426 AM PDT Tue Mar 25 2014
.Synopsis...
Wet and cooler weather will arrive today and continue through the
weekend. Significant mountain snow and gusty winds are likely with
possible thunderstorms in the Valley.
&&
.Discussion...
Major pattern change begins for interior NorCal today as the
persistent ridge along the west coast gives way to a trough over
the eastern Pacific extending southward from a deep upper low over
the NE Pacific off the coast of BC. A series of weather systems
emanating from this low are forecast to affect the region for at
least the next week or so.
The first in the series of weather systems is presently nearing
the northern CA coast. Radar shows the frontal band just off the
NW coast of CA early this morning, and it will move eastward
across the region today. Precip is expected to begin in the
Redding area this morning, in the Sacramento region this afternoon
and spread east into the northern Sierra by late today or this
evening.
This first system will only bring modest precip totals for the
area. It may also bring a chance of thunderstorms across the
valley later today if the frontal band moves through quick enough
allowing for some clearing late in the day. The latest HRRR times
the back edge of the frontal band through the valley by mid-
afternoon, so this is something to watch this afternoon. Models
continue to show the best instability and surface convergence
across the southern half of the Sacramento Valley southward into
the northern SJ Valley. Snow levels will start initially high
with this system, but rapidly drop below 6000 ft by evening.
Another wave of precip and colder air arrives on Wednesday and
continues into Thursday. With westerly to southwesterly flow
aloft, favorable orographics are expected over the Sierra but may
limit precipitation along the downslope parts of the Sacramento
Valley. Through these two events, potentially up to an inch of
rain will be possible over parts of the Valley. Snow levels will
drop down to around 4000 ft with 4 to 8 inches possible above that
level. Over a foot of snow is expected above 5500 ft with 2 feet
along the northern Sierra crest. Strong winds will also be
possible over mountain ridges.
Convective parameters still look decent for thunderstorms on
Wednesday, with perhaps a bit more upper support when compared to
today. Convection may be a bit more widespread on Wednesday, but
this will once again depend on how much surface clearing is able
to develop during the period of peak heating (afternoon). Wind
shear profiles look very favorable for rotating updrafts on
Wednesday with long looping hodographs indicative of strongly
veering winds with height. An isolated tornado or two may be
possible depending on whether discrete cells are able to develop.
Showery weather continues Thursday, mainly over the mountains, as
cyclonic NWLY flow remains over NorCal. Deeper moisture with
another system begins to affect the region later Friday and Friday
night.
&&
.Extended Discussion (Saturday through Tuesday)...
Extended models in good agreement in bringing next Pacific frontal
system on to the north coast by 12z Saturday. Precipitable water
proggs showing a sub tropical moisture feed of around an inch TPW
so this should be a moderately wet system. Snow levels will start
out fairly high at about 6000 feet but then drop on Sunday as the
colder air behind the cold front filters into the area. By this
time however...most of the precipitation will have ended. Breezy
to windy conditions will accompany this system as well with
moderately tight pressure gradients both surface and aloft
predicted. Showers on Sunday with a brief break Sunday night will
be followed but yet another frontal passage on Monday as models
keep upper level troughing over the eastern Pacific. At this
time...this system does not look as wet as the one moving through
over the weekend but it should be a colder system with snow levels
dropping to between 3000 and 4000 feet by Tuesday morning. Showery
and cool conditions expected to continue through the day Tuesday
with daytime highs expected to remain a few to several degrees
below normal.
&&
.Aviation...
Pacific frontal system pushing on to the north coast this morning
will bring lowering ceilings after 18z today north and west of
about kcic and across most areas of NORCAL by this evening.
Ceilings transitioning from VFR this morning to MVFR over the
valley and foothills this afternoon and evening with rain and a
slight chance of thunderstorms. Coastal mountains becoming IFR
after 18z with IFR conditions over the Sierra Cascade range after
00z for low ceilings and rain and snow. Snow level around 5000
feet. Low ceilings continuing through 12z.
&&
.STO Watches/Warnings/Advisories...
Winter storm warning from 3 pm this afternoon to 11 am pdt thursday
above 5500 feet in the west slope northern sierra nevada...western
plumas county/lassen park.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
849 AM EDT TUE MAR 25 2014
.UPDATE...MADE SOME ADJUSTMENTS TO HOURLY CLOUD COVER FORECAST
BASED ON SATELLITE TRENDS SHOWING PARTIAL CLEARING IN OUR WRN
COUNTIES...WITH CLEAR SKIES SPREADING INTO WRN FL PNDL AND SW GA.
WITH SUBSIDENCE MOVING IN...SHOULD SEE CLOUDINESS DECREASE FROM
W TO E OVER OUR FORECAST AREA DURING THE LATE MORNING/EARLY
AFTERNOON HOURS...AS INDICATED IN LATEST HRRR GUIDANCE. CURRENT
HIGH TEMP FORECAST LOOKS GOOD BASED ON AFTERNOON SUNSHINE.
ANTICIPATING BREEZY CONDITIONS ESP IN THE AFTERNOON...LAMP GUID
SUGGESTING GUSTS INTO 26-30KT RANGE...SO LAKE WIND ADVISORY LOOKS
OKAY.
&&
.AVIATION...SATELLITE TRENDS CONFIRM CURRENT TAF FORECAST OF
IMPROVING CONDITIONS THRU EARLY AFTERNOON.
&&
.MARINE...NO CHANGES IN NEXT CWF ISSUANCE WITH INCREASING WINDS/SEAS
EXPECTED. CURRENT HEADLINES LOOK FINE...WITH FREQUENT WIND GUSTS TO
GALE FORCE EXPECTED THIS EVENING ACROSS OFFSHORE COMPONENT.
RIP CURRENTS: MODERATE RISK TODAY WITH LONG-PERIOD NE SWELL AND
ELEVATED SURF. LOW TO MODERATE RISK WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 66 31 59 37 / 10 0 0 0
SSI 64 37 56 44 / 20 0 0 10
JAX 71 35 58 40 / 10 0 0 10
SGJ 70 41 57 48 / 10 0 0 10
GNV 73 34 61 39 / 10 0 0 10
OCF 76 36 62 40 / 10 0 0 10
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...LAKE WIND ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
ALACHUA-BAKER-BRADFORD-CLAY-COLUMBIA-DUVAL-FLAGLER-
GILCHRIST-HAMILTON-MARION-NASSAU-PUTNAM-ST JOHNS-SUWANNEE-
UNION.
GA...FREEZE WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING FOR
APPLING-ATKINSON-BACON-BRANTLEY-COFFEE-JEFF DAVIS-PIERCE-
WAYNE.
LAKE WIND ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
APPLING-ATKINSON-BACON-BRANTLEY-CHARLTON-CLINCH-COASTAL
CAMDEN-COASTAL GLYNN-COFFEE-ECHOLS-INLAND CAMDEN-INLAND
GLYNN-JEFF DAVIS-PIERCE-WARE-WAYNE.
AM...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR ALTAMAHA
SOUND GA TO FERNANDINA BEACH FL 20 NM TO 60 NM OFFSHORE-
FERNANDINA BEACH TO ST AUGUSTINE FL 20 NM TO 60 NM OFFSHORE-
ST AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM OFFSHORE.
GALE WARNING FROM 7 PM THIS EVENING TO 6 AM EDT WEDNESDAY FOR
ALTAMAHA SOUND GA TO FERNANDINA BEACH FL 20 NM TO 60 NM
OFFSHORE-FERNANDINA BEACH TO ST AUGUSTINE FL 20 NM TO 60 NM
OFFSHORE-ST AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM
OFFSHORE.
SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 6 AM EDT
WEDNESDAY FOR ALTAMAHA SOUND GA TO FERNANDINA BEACH FL OUT
20 NM-FERNANDINA BEACH TO ST AUGUSTINE FL OUT 20 NM-ST
AUGUSTINE TO FLAGLER BEACH FL OUT 20 NM.
&&
$$
WOLF/HESS
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
1034 AM CDT TUE MAR 25 2014
.DISCUSSION...
1035 AM CDT
THERE WERE MAINLY JUST SOME TWEAKS TO HOURLY CONDITIONS FOR THE
FORECAST THE REST OF TODAY...OTHERWISE ALL IS IN GOOD SHAPE.
THE 12Z RAOBS INDICATED 850-500MB READINGS THAT WERE ABOUT AS
COLD AS THEY CAN REACH IN THIS REGION DURING LATE MARCH. THE
850-925MB COLD AIR ADVECTION IS AT IS MAX OVER THE CWA LATE THIS
MORNING...WITH -18C KNOCKING ON THE DOOR PER THE RAP ANALYSIS.
THIS AIDED BY A SHEARED SHORT WAVE LOOK TO KEEP SCATTERED LIGHT
SNOW SHOWERS/FLURRIES GOING INTO EARLY AFTERNOON. REMARKABLY DRY
LOW-LEVEL AIR LOOKS TO SPREAD IN BY MID-AFTERNOON WITH UPSTREAM
DEW POINT OBSERVATIONS IN THE LOWER TO MID SINGLE DIGITS. THE
SURFACE PRESSURE GRADIENT REMAINS TIGHT AND SOUNDINGS SUPPORT
GUSTS THROUGH THE AFTERNOON...WITH A RELAXING GRADIENT MOVING
QUICKLY IN THIS EVENING AS HIGH PRESSURE BUILDS IN FROM THE PLAINS.
MTF
&&
.PREV DISCUSSION...
NARROW BUT INTENSE BAND OF SNOW ALONG COLD FRONT WILL CONTINUE TO
MOVE ACROSS THE SOUTHEAST HALF OF THE CWA OVER THE NEXT FEW HOURS.
GENERALLY QUICK DROP TO 1/4SM VIS WITH 0.5-1.0 INCH ACCUMULATIONS IN
20 MINUTES WITHIN THE HEAVIER SNOW SHOWERS. EXTRAPOLATION OF RADAR
LOOP INDICATES BAND SHOULD EXIT ALL BUT PERHAPS THE EXTREME
SOUTHEAST PART OF THE FORECAST AREA BY SUNRISE...WITH A FEW LIGHTER
SNOW SHOWERS ALSO ACROSS FAR NORTHEAST IL BENEATH PATH OF MID-LEVEL
VORT DURING THAT TIME. RELATIVELY DRY ARCTIC AIR SPREADING IN FROM
THE NORTHWEST WILL ALLOW SOME SCATTERING OF CLOUD COVER AND AN END
TO ACCUMULATING SNOW SHOWERS BY SUNRISE...THOUGH ONE MORE SHORT WAVE
DROPPING SOUTHEAST ACROSS MINNESOTA AT 08Z MAY BE ENOUGH TO PRODUCE
SOME ENHANCED STRATOCU AND A FEW FLURRIES ACROSS THE REGION DURING
THE MID/LATE MORNING HOURS. IN THE WAKE OF THE PASSAGE OF THIS
MID-LEVEL VORT AXIS AROUND MIDDAY...RISING HEIGHTS AND SUBSIDENCE
SHOULD RESULT IN AN END TO FLURRIES AND THINNING/EROSION OF THE
STRATOCU DECK ALLOWING PARTLY CLOUDY/MOSTLY SUNNY SKIES THIS
AFTERNOON. BLUSTERY NORTHWEST WINDS WILL KEEP TEMPS WELL BELOW
NORMAL ONCE AGAIN...WITH UPPER 20S/LOW 30S EXPECTED FOR AFTERNOON
HIGHS PER BIAS CORRECTED MOS BLEND. BROAD UPPER RIDGE BUILDS ACROSS
THE REGION TONIGHT IN THE WAKE OF OUR DEPARTING EASTERN CONUS UPPER
TROUGH WITH SURFACE HIGH PRESSURE RIDGE BUILDING INTO THE REGION
OVERNIGHT. THIS MORNINGS LIGHT SNOWFALL WILL BE GONE BY
TONIGHT...THOUGH LIGHT WINDS AND CLEAR SKIES WILL ALLOW FOR COOLING
INTO THE TEENS IN MOST AREAS BY WEDNESDAY MORNING.
SURFACE HIGH PRESSURE MOVES QUICKLY EAST OF THE FORECAST AREA
WEDNESDAY AS SURFACE PRESSURE FALLS DEVELOP ACROSS THE PLAINS AND
MISSISSIPPI VALLEY IN RESPONSE TO SURFACE LOW DEVELOPING OVER THE
DAKOTAS IN ADVANCE OF AN UPPER TROUGH OVER THE WESTERN CONUS AND
UPPER JET MAX SPREADING ACROSS THE CENTRAL AND SOUTHERN ROCKIES.
THIS RESULTS IN FAIRLY QUICK WARM ADVECTION AND MOISTURE TRANSPORT
INTO THE REGION ESPECIALLY ABOVE THE BOUNDARY LAYER AS 40-50 KT
SOUTH-SOUTHWESTERLY LOW LEVEL JET DEVELOPS BY LATE AFTERNOON.
INCREASING MID-LEVEL CLOUD COVER WILL LIKELY OFFSET SOME OF THE
WARMING AS WILL A SLIGHT SOUTHEAST COMPONENT TO THE BOUNDARY LAYER
WIND. EVEN SO...FAVOR WARMER MAV GUIDANCE OF WEDNESDAY AFTERNOON MAX
TEMPS IN THE UPPER 30S/LOWER 40S. EXCEPTION WILL BE ALONG THE
IMMEDIATE NORTH SHORE AREA...WHERE THAT SLIGHT SOUTHEAST WIND
COMPONENT MAY HOLD TEMPS IN THE MID 30S RIGHT ALONG THE LAKE. DEEPER
MOISTURE CONTINUES TO SPREAD INTO THE REGION WEDNESDAY NIGHT...AS
SURFACE LOW MOVES INTO THE UPPER MISSISSIPPI VALLEY AND A SHORT WAVE
TROUGH PROPAGATES FROM THE SOUTH CENTRAL PLAINS INTO THE WESTERN
GREAT LAKES. FORECAST SOUNDINGS DEPICT DEEP SATURATION OCCURRING
MAINLY AFTER MIDNIGHT...WITH SUFFICIENT FORCING APPROACHING SHORT
WAVE AND ISENTROPIC ASCENT/JET DIVERGENCE TO GO WITH LIKELY POPS.
THERMAL PROFILES BECOME NEARLY ISOTHERMAL NEAR 0C IN THE LOWER
LEVELS INITIALLY BEFORE WARM ADVECTION OVERWHELMS THE
COLUMN...SUGGESTING THE POTENTIAL FOR S BRIEF MIX OF RAIN/SNOW WITH
THE ONSET OF PRECIP...BUT QUICKLY TURNING TO RAIN AS 50-60 KT LOW
LEVEL JET CONTINUES TO PUMP IN WARM/MOIST AIR. TIGHT SFC PRESSURE
GRADIENT WILL MAINTAIN BREEZY SOUTH WINDS OVERNIGHT AS WELL...WHICH
WILL LIKELY KEEP TEMPS ABOVE FREEZING OVERNIGHT AND PROBABLY RISING
BEFORE SUNRISE. INITIAL SHORT WAVE LIFTS ACROSS THE AREA THURSDAY
MORNING...WITH AN AREA OF MODESTLY STEEP MID-LEVEL LAPSE RATES NOTED
ACROSS CENTRAL IL AND SOUTHERN CWA. HAVE INDICATED ISOLATED THUNDER
FAR SOUTH DURING THE MORNING PERIOD WITH THESE BETTER ELEVATED LAPSE
RATES BEFORE SOME MID-LEVEL DRYING OCCURS BEHIND THE INITIAL SHORT
WAVE. SHOWER CHANCES REMAIN RELATIVELY HIGH THROUGH THE DAY THURSDAY
IN MOIST WARM SECTOR...WITH GFS PRECIPITABLE WATER NEAR 0.9
INCHES...AND APPROACH OF SECOND SHORT WAVE/MAIN TROUGH AXIS LATER IN
THE DAY ALONG WITH APPROACH OF SURFACE COLD FRONT THURSDAY EVENING.
ECMWF REMAINS A LITTLE SLOWER WITH THE PASSAGE OF THE LOW/COLD FRONT
THURSDAY NIGHT...SO HAVE MAINTAINED POPS INTO THE NIGHT WITH A LOW
CHANCE LINGERING IN THE FAR EAST INTO EARLY FRIDAY. MILD/MOIST AIR
MASS SHOULD PUSH TEMPS UP AROUND 50 THURSDAY DESPITE CLOUDS/PRECIP.
COOLER AIR WORKS IN FRIDAY WITH WEAK HIGH PRESSURE RIDGE BEHIND
DEPARTING SYSTEM...WITH WINDS LIKELY TURNING NORTHEAST OFF THE LAKE
FRIDAY AFTERNOON KEEPING LAKESIDE LOCATIONS CHILLY AROUND 40 DEG.
GUIDANCE IN GOOD AGREEMENT IN BRINGING ANOTHER PROGRESSIVE AMPLIFIED
SHORT WAVE ACROSS THE AREA FRIDAY NIGHT/SATURDAY...WITH AN AREA OF
SURFACE LOW PRESSURE PASSING SOUTH OF THE CWA. MOST OF THE PRECIP
REMAINS SOUTH/SOUTHEAST OF THE FORECAST AREA WITH THIS FEATURE...
THOUGH HAVE INCLUDED LOW CHANCE POPS MAINLY FRIDAY NIGHT. PRECIP
TYPE COULD BE A QUESTION ESPECIALLY SOUTH WHERE IT COULD BE A
RAIN/SNOW MIX PER THICKNESS PROGS AND THERMAL PROFILES. NORTHEAST
WINDS AROUND THE NORTHERN PERIPHERY OF THE PASSING LOW WILL CONTINUE
TO HOLD TEMPS BELOW NORMAL...ESPECIALLY NEAR LAKE MICHIGAN. MODELS
CONTINUE TO DEVELOP ANOTHER DEEP LOW ACROSS THE NORTHERN PLAINS
SUNDAY/MONDAY...WITH STRONG SOUTH FLOW DEVELOPING AND OFFERING THE
PROSPECT OF WARMER WEATHER BY THE END OF THE FORECAST PERIOD.
BLENDED GUIDANCE INDICATES 55-60+ DEGREES SUNDAY AND MONDAY...THOUGH
WITH BREEZY CONDITIONS AND AN INCREASING POTENTIAL FOR RAIN MONDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* CHANCE OF FLURRIES/LIGHT SNOW SHOWERS THIS MORNING.
* STRONG/GUSTY NORTHWEST WINDS THROUGH LATE AFTERNOON. CMS
//DISCUSSION...UPDATED 12Z...
TODAY WILL BE A WINDY AND VFR DAY IN BETWEEN LOW PRESSURE MOVING
EAST AND EXPANSIVE ARCTIC HIGH PRESSURE SPREADING SOUTHEAST FROM
THE NORTHERN PLAINS. NORTHWEST WINDS WILL GUST TO THE MID-HIGH
20S KTS FROM 14 OR 15Z THROUGH MID TO LATE AFTERNOON. THE ONLY
MINOR CONCERN IS WITH AN UPPER DISTURBANCE CURRENTLY PRODUCING
ISOLATED/SCT SHSN OVER NORTHEAST IA AND SOUTHWEST WI. THIS
DISTURBANCE WILL MOVE SOUTHEAST AND LIGHT SNOW SHOWERS OR FLURRIES
COULD MOVE OVER THE AREA FROM MID TO LATE MORNING. HAVE LEFT THE
TAFS DRY...BUT WILL NEED TO MONITOR TRENDS OVER THE NEXT FEW
HOURS. BEST FORCING WILL BE MAINLY WEST/SW OF THE TAF SITES...SO
IT APPEARS RFD WOULD HAVE A BETTER BUT STILL LOW CHANCE AT
ANYTHING MORE THAN FLURRIES. FORECAST SOUNDINGS INDICATE THAT
DIURNALLY DRIVEN SCT TO BKN VFR CLOUDS WILL BE AROUND 4-5KFT AGL.
AS HIGH PRESSURE MOVES OVERHEAD TONIGHT...SKIES WILL CLEAR AND
WINDS QUICKLY DIMINISH...WITH LIGHT/VRB TO CALM OVERNIGHT INTO
EARLY WEDS. LIGHT SOUTHERLY WINDS WILL DEVELOP WEDNESDAY MORNING
AS THE HIGH PRESSURE SLIDES EAST.
RC
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM FOR FLURRIES/LIGHT SNOW SHOWERS THIS MORNING.
* HIGH FOR WIND SPEEDS/GUSTS/DIRECTIONS THROUGH THIS EVENING. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...CHANCE OF RA AND MVFR. MAY START AS RA/SN MIX.
THURSDAY...PERIODS OF SHRA AND SUB VFR LIKELY. GUSTY SOUTH WINDS.
FRIDAY...VFR PROBABLE. WIND SHIFT TO NORTHEAST LATE DAY. SLIGHT
CHANCE -SN FRIDAY NIGHT.
SATURDAY...VFR LIKELY. NORTHEAST TO EAST WINDS.
SUNDAY...VFR. GUSTY SOUTH-SOUTHWEST WINDS. SLIGHT CHANCE SHRA SUN.
NIGHT.
MONDAY...CHANCE SHRA AND SUB VFR. GUSTY SOUTHWEST WINDS.
RC
&&
.MARINE...
354 AM CDT
A FEW ACTIVE PERIODS COMING UP ON THE LAKE THROUGH THE END OF THE
WORK WEEK. NORTHWEST WINDS GUSTING TO 30 KT THROUGH LATE AFTERNOON
ON THE SOUTH HALF TODAY AND SMALL CRAFT CRITERIA WINDS...WITH WAVES
SUBSIDING DURING THE EVENING.
HIGH PRESSURE MOVING OVER THE LAKE TONIGHT THROUGH EARLY WEDNESDAY
WILL RESULT IN A BRIEF QUIET PERIOD. AS THE HIGH PRESSURE SLIDES
EAST ON WEDNESDAY...STRONG LOW PRESSURE WILL TAKE SHAPE ACROSS THE
CENTRAL PLAINS AND MOVE EAST. THIS WILL RESULT IN RAPIDLY INCREASING
SOUTHERLY WINDS LATE DAY WEDNESDAY THROUGH WEDNESDAY NIGHT. THE AIR
MASS WILL BE WARMING BUT STILL LOOKS TO BE MARGINALLY UNSTABLE
ENOUGH FOR A PERIOD OF GALES ON THE SOUTHERN AND CENTRAL PORTION OF
THE LAKE. HAVE NOT ISSUED A WATCH DUE TO LIMITED DURATION AND LOWER
CONFIDENCE IN PREVAILING OCCURRENCE OF GALES. WILL NEED A SMALL
CRAFT ADVISORY FOR THE NEARSHORE WATERS AND DID MENTION POTENTIAL
FOR A FEW GALE FORCE GUSTS AFTER MIDNIGHT WEDNESDAY NIGHT.
STRONG SOUTH-SOUTHWEST WINDS WILL CONTINUE THROUGH THURSDAY EVENING
AS THE LOW DRAWS NEARER. STABLE CONDITIONS WILL LIMIT
MIXING...THOUGH WINDS JUST ABOVE THE BOUNDARY LAYER COULD APPROACH
40 KT. SOME GUIDANCE CONTINUES TO KEEP MIXING ONGOING PART OF
THURSDAY ON THE NORTH HALF OF THE LAKE. HAVE OPTED TO CAP SPEEDS
BELOW GALES ON THURSDAY ACROSS THE LAKE DUE TO UNCERTAINTY WITH
MIXING. GALES ARE POSSIBLE FOR THE NEARSHORE PART OF THURSDAY DUE
TO PROXIMITY TO BETTER MIXED LAND AREA. AFTER THE LOW CROSSES THE
LAKE THURSDAY NIGHT...THE TRAILING COLD FRONT WILL SWEEP ACROSS
THE LAKE...WITH WINDS SHIFTING NORTHWEST TO 25 TO 30 KT INTO
FRIDAY BEFORE BACKING NORTHERLY AND GRADUALLY DIMINISHING IN THE
AFTERNOON. ANOTHER LOW WILL TRACK ACROSS THE OHIO VALLEY EARLY
SATURDAY AND IF IT GETS CLOSE ENOUGH TO LAKE...NORTHEAST WINDS ON
SOUTH HALF COULD BE STRONGER THAN INDICATED. WINDS WILL TURN
SOUTHERLY AND INCREASE ON SUNDAY THROUGH SUNDAY NIGHT IN ADVANCE
OF ANOTHER STRONG LOW PRESSURE AREA THAT WILL MOVE ACROSS THE
REGION ON MONDAY.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 PM TUESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
655 AM CDT TUE MAR 25 2014
.DISCUSSION...
NARROW BUT INTENSE BAND OF SNOW ALONG COLD FRONT WILL CONTINUE TO
MOVE ACROSS THE SOUTHEAST HALF OF THE CWA OVER THE NEXT FEW HOURS.
GENERALLY QUICK DROP TO 1/4SM VIS WITH 0.5-1.0 INCH ACCUMULATIONS IN
20 MINUTES WITHIN THE HEAVIER SNOW SHOWERS. EXTRAPOLATION OF RADAR
LOOP INDICATES BAND SHOULD EXIT ALL BUT PERHAPS THE EXTREME
SOUTHEAST PART OF THE FORECAST AREA BY SUNRISE...WITH A FEW LIGHTER
SNOW SHOWERS ALSO ACROSS FAR NORTHEAST IL BENEATH PATH OF MID-LEVEL
VORT DURING THAT TIME. RELATIVELY DRY ARCTIC AIR SPREADING IN FROM
THE NORTHWEST WILL ALLOW SOME SCATTERING OF CLOUD COVER AND AN END
TO ACCUMULATING SNOW SHOWERS BY SUNRISE...THOUGH ONE MORE SHORT WAVE
DROPPING SOUTHEAST ACROSS MINNESOTA AT 08Z MAY BE ENOUGH TO PRODUCE
SOME ENHANCED STRATOCU AND A FEW FLURRIES ACROSS THE REGION DURING
THE MID/LATE MORNING HOURS. IN THE WAKE OF THE PASSAGE OF THIS
MID-LEVEL VORT AXIS AROUND MIDDAY...RISING HEIGHTS AND SUBSIDENCE
SHOULD RESULT IN AN END TO FLURRIES AND THINNING/EROSION OF THE
STRATOCU DECK ALLOWING PARTLY CLOUDY/MOSTLY SUNNY SKIES THIS
AFTERNOON. BLUSTERY NORTHWEST WINDS WILL KEEP TEMPS WELL BELOW
NORMAL ONCE AGAIN...WITH UPPER 20S/LOW 30S EXPECTED FOR AFTERNOON
HIGHS PER BIAS CORRECTED MOS BLEND. BROAD UPPER RIDGE BUILDS ACROSS
THE REGION TONIGHT IN THE WAKE OF OUR DEPARTING EASTERN CONUS UPPER
TROUGH WITH SURFACE HIGH PRESSURE RIDGE BUILDING INTO THE REGION
OVERNIGHT. THIS MORNINGS LIGHT SNOWFALL WILL BE GONE BY
TONIGHT...THOUGH LIGHT WINDS AND CLEAR SKIES WILL ALLOW FOR COOLING
INTO THE TEENS IN MOST AREAS BY WEDNESDAY MORNING.
SURFACE HIGH PRESSURE MOVES QUICKLY EAST OF THE FORECAST AREA
WEDNESDAY AS SURFACE PRESSURE FALLS DEVELOP ACROSS THE PLAINS AND
MISSISSIPPI VALLEY IN RESPONSE TO SURFACE LOW DEVELOPING OVER THE
DAKOTAS IN ADVANCE OF AN UPPER TROUGH OVER THE WESTERN CONUS AND
UPPER JET MAX SPREADING ACROSS THE CENTRAL AND SOUTHERN ROCKIES.
THIS RESULTS IN FAIRLY QUICK WARM ADVECTION AND MOISTURE TRANSPORT
INTO THE REGION ESPECIALLY ABOVE THE BOUNDARY LAYER AS 40-50 KT
SOUTH-SOUTHWESTERLY LOW LEVEL JET DEVELOPS BY LATE AFTERNOON.
INCREASING MID-LEVEL CLOUD COVER WILL LIKELY OFFSET SOME OF THE
WARMING AS WILL A SLIGHT SOUTHEAST COMPONENT TO THE BOUNDARY LAYER
WIND. EVEN SO...FAVOR WARMER MAV GUIDANCE OF WEDNESDAY AFTERNOON MAX
TEMPS IN THE UPPER 30S/LOWER 40S. EXCEPTION WILL BE ALONG THE
IMMEDIATE NORTH SHORE AREA...WHERE THAT SLIGHT SOUTHEAST WIND
COMPONENT MAY HOLD TEMPS IN THE MID 30S RIGHT ALONG THE LAKE. DEEPER
MOISTURE CONTINUES TO SPREAD INTO THE REGION WEDNESDAY NIGHT...AS
SURFACE LOW MOVES INTO THE UPPER MISSISSIPPI VALLEY AND A SHORT WAVE
TROUGH PROPAGATES FROM THE SOUTH CENTRAL PLAINS INTO THE WESTERN
GREAT LAKES. FORECAST SOUNDINGS DEPICT DEEP SATURATION OCCURRING
MAINLY AFTER MIDNIGHT...WITH SUFFICIENT FORCING APPROACHING SHORT
WAVE AND ISENTROPIC ASCENT/JET DIVERGENCE TO GO WITH LIKELY POPS.
THERMAL PROFILES BECOME NEARLY ISOTHERMAL NEAR 0C IN THE LOWER
LEVELS INITIALLY BEFORE WARM ADVECTION OVERWHELMS THE
COLUMN...SUGGESTING THE POTENTIAL FOR S BRIEF MIX OF RAIN/SNOW WITH
THE ONSET OF PRECIP...BUT QUICKLY TURNING TO RAIN AS 50-60 KT LOW
LEVEL JET CONTINUES TO PUMP IN WARM/MOIST AIR. TIGHT SFC PRESSURE
GRADIENT WILL MAINTAIN BREEZY SOUTH WINDS OVERNIGHT AS WELL...WHICH
WILL LIKELY KEEP TEMPS ABOVE FREEZING OVERNIGHT AND PROBABLY RISING
BEFORE SUNRISE. INITIAL SHORT WAVE LIFTS ACROSS THE AREA THURSDAY
MORNING...WITH AN AREA OF MODESTLY STEEP MID-LEVEL LAPSE RATES NOTED
ACROSS CENTRAL IL AND SOUTHERN CWA. HAVE INDICATED ISOLATED THUNDER
FAR SOUTH DURING THE MORNING PERIOD WITH THESE BETTER ELEVATED LAPSE
RATES BEFORE SOME MID-LEVEL DRYING OCCURS BEHIND THE INITIAL SHORT
WAVE. SHOWER CHANCES REMAIN RELATIVELY HIGH THROUGH THE DAY THURSDAY
IN MOIST WARM SECTOR...WITH GFS PRECIPITABLE WATER NEAR 0.9
INCHES...AND APPROACH OF SECOND SHORT WAVE/MAIN TROUGH AXIS LATER IN
THE DAY ALONG WITH APPROACH OF SURFACE COLD FRONT THURSDAY EVENING.
ECMWF REMAINS A LITTLE SLOWER WITH THE PASSAGE OF THE LOW/COLD FRONT
THURSDAY NIGHT...SO HAVE MAINTAINED POPS INTO THE NIGHT WITH A LOW
CHANCE LINGERING IN THE FAR EAST INTO EARLY FRIDAY. MILD/MOIST AIR
MASS SHOULD PUSH TEMPS UP AROUND 50 THURSDAY DESPITE CLOUDS/PRECIP.
COOLER AIR WORKS IN FRIDAY WITH WEAK HIGH PRESSURE RIDGE BEHIND
DEPARTING SYSTEM...WITH WINDS LIKELY TURNING NORTHEAST OFF THE LAKE
FRIDAY AFTERNOON KEEPING LAKESIDE LOCATIONS CHILLY AROUND 40 DEG.
GUIDANCE IN GOOD AGREEMENT IN BRINGING ANOTHER PROGRESSIVE AMPLIFIED
SHORT WAVE ACROSS THE AREA FRIDAY NIGHT/SATURDAY...WITH AN AREA OF
SURFACE LOW PRESSURE PASSING SOUTH OF THE CWA. MOST OF THE PRECIP
REMAINS SOUTH/SOUTHEAST OF THE FORECAST AREA WITH THIS FEATURE...
THOUGH HAVE INCLUDED LOW CHANCE POPS MAINLY FRIDAY NIGHT. PRECIP
TYPE COULD BE A QUESTION ESPECIALLY SOUTH WHERE IT COULD BE A
RAIN/SNOW MIX PER THICKNESS PROGS AND THERMAL PROFILES. NORTHEAST
WINDS AROUND THE NORTHERN PERIPHERY OF THE PASSING LOW WILL CONTINUE
TO HOLD TEMPS BELOW NORMAL...ESPECIALLY NEAR LAKE MICHIGAN. MODELS
CONTINUE TO DEVELOP ANOTHER DEEP LOW ACROSS THE NORTHERN PLAINS
SUNDAY/MONDAY...WITH STRONG SOUTH FLOW DEVELOPING AND OFFERING THE
PROSPECT OF WARMER WEATHER BY THE END OF THE FORECAST PERIOD.
BLENDED GUIDANCE INDICATES 55-60+ DEGREES SUNDAY AND MONDAY...THOUGH
WITH BREEZY CONDITIONS AND AN INCREASING POTENTIAL FOR RAIN MONDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* LOW CHANCE OF FLURRIES OR LIGHT SNOW SHOWERS DURING MID-LATE AM.
* NORTHWEST WINDS GUSTING TO 25 KT FROM MID MORNING THROUGH LATE
AFTERNOON.
RC
//DISCUSSION...UPDATED 12Z...
TODAY WILL BE A WINDY AND VFR DAY IN BETWEEN LOW PRESSURE MOVING
EAST AND EXPANSIVE ARCTIC HIGH PRESSURE SPREADING SOUTHEAST FROM
THE NORTHERN PLAINS. NORTHWEST WINDS WILL GUST TO THE MID-HIGH
20S KTS FROM 14 OR 15Z THROUGH MID TO LATE AFTERNOON. THE ONLY
MINOR CONCERN IS WITH AN UPPER DISTURBANCE CURRENTLY PRODUCING
ISOLATED/SCT SHSN OVER NORTHEAST IA AND SOUTHWEST WI. THIS
DISTURBANCE WILL MOVE SOUTHEAST AND LIGHT SNOW SHOWERS OR FLURRIES
COULD MOVE OVER THE AREA FROM MID TO LATE MORNING. HAVE LEFT THE
TAFS DRY...BUT WILL NEED TO MONITOR TRENDS OVER THE NEXT FEW
HOURS. BEST FORCING WILL BE MAINLY WEST/SW OF THE TAF SITES...SO
IT APPEARS RFD WOULD HAVE A BETTER BUT STILL LOW CHANCE AT
ANYTHING MORE THAN FLURRIES. FORECAST SOUNDINGS INDICATE THAT
DIURNALLY DRIVEN SCT TO BKN VFR CLOUDS WILL BE AROUND 4-5KFT AGL.
AS HIGH PRESSURE MOVES OVERHEAD TONIGHT...SKIES WILL CLEAR AND
WINDS QUICKLY DIMINISH...WITH LIGHT/VRB TO CALM OVERNIGHT INTO
EARLY WEDS. LIGHT SOUTHERLY WINDS WILL DEVELOP WEDNESDAY MORNING
AS THE HIGH PRESSURE SLIDES EAST.
RC
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM-HIGH THAT THERE WILL BE NO SIGNIFICANT IMPACTS FROM PSBL
-SHSN NEARBY MID-LATE AM.
* HIGH IN WIND/GUST TRENDS AND REMAINING FORECAST ELEMENTS.
RC
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...CHANCE OF RA AND MVFR. MAY START AS RA/SN MIX.
THURSDAY...PERIODS OF SHRA AND SUB VFR LIKELY. GUSTY SOUTH WINDS.
FRIDAY...VFR PROBABLE. WIND SHIFT TO NORTHEAST LATE DAY. SLIGHT
CHANCE -SN FRIDAY NIGHT.
SATURDAY...VFR LIKELY. NORTHEAST TO EAST WINDS.
SUNDAY...VFR. GUSTY SOUTH-SOUTHWEST WINDS. SLIGHT CHANCE SHRA SUN.
NIGHT.
MONDAY...CHANCE SHRA AND SUB VFR. GUSTY SOUTHWEST WINDS.
RC
&&
.MARINE...
354 AM CDT
A FEW ACTIVE PERIODS COMING UP ON THE LAKE THROUGH THE END OF THE
WORK WEEK. NORTHWEST WINDS GUSTING TO 30 KT THROUGH LATE AFTERNOON
ON THE SOUTH HALF TODAY AND SMALL CRAFT CRITERIA WINDS...WITH WAVES
SUBSIDING DURING THE EVENING.
HIGH PRESSURE MOVING OVER THE LAKE TONIGHT THROUGH EARLY WEDNESDAY
WILL RESULT IN A BRIEF QUIET PERIOD. AS THE HIGH PRESSURE SLIDES
EAST ON WEDNESDAY...STRONG LOW PRESSURE WILL TAKE SHAPE ACROSS THE
CENTRAL PLAINS AND MOVE EAST. THIS WILL RESULT IN RAPIDLY INCREASING
SOUTHERLY WINDS LATE DAY WEDNESDAY THROUGH WEDNESDAY NIGHT. THE AIR
MASS WILL BE WARMING BUT STILL LOOKS TO BE MARGINALLY UNSTABLE
ENOUGH FOR A PERIOD OF GALES ON THE SOUTHERN AND CENTRAL PORTION OF
THE LAKE. HAVE NOT ISSUED A WATCH DUE TO LIMITED DURATION AND LOWER
CONFIDENCE IN PREVAILING OCCURRENCE OF GALES. WILL NEED A SMALL
CRAFT ADVISORY FOR THE NEARSHORE WATERS AND DID MENTION POTENTIAL
FOR A FEW GALE FORCE GUSTS AFTER MIDNIGHT WEDNESDAY NIGHT.
STRONG SOUTH-SOUTHWEST WINDS WILL CONTINUE THROUGH THURSDAY EVENING
AS THE LOW DRAWS NEARER. STABLE CONDITIONS WILL LIMIT
MIXING...THOUGH WINDS JUST ABOVE THE BOUNDARY LAYER COULD APPROACH
40 KT. SOME GUIDANCE CONTINUES TO KEEP MIXING ONGOING PART OF
THURSDAY ON THE NORTH HALF OF THE LAKE. HAVE OPTED TO CAP SPEEDS
BELOW GALES ON THURSDAY ACROSS THE LAKE DUE TO UNCERTAINTY WITH
MIXING. GALES ARE POSSIBLE FOR THE NEARSHORE PART OF THURSDAY DUE
TO PROXIMITY TO BETTER MIXED LAND AREA. AFTER THE LOW CROSSES THE
LAKE THURSDAY NIGHT...THE TRAILING COLD FRONT WILL SWEEP ACROSS
THE LAKE...WITH WINDS SHIFTING NORTHWEST TO 25 TO 30 KT INTO
FRIDAY BEFORE BACKING NORTHERLY AND GRADUALLY DIMINISHING IN THE
AFTERNOON. ANOTHER LOW WILL TRACK ACROSS THE OHIO VALLEY EARLY
SATURDAY AND IF IT GETS CLOSE ENOUGH TO LAKE...NORTHEAST WINDS ON
SOUTH HALF COULD BE STRONGER THAN INDICATED. WINDS WILL TURN
SOUTHERLY AND INCREASE ON SUNDAY THROUGH SUNDAY NIGHT IN ADVANCE
OF ANOTHER STRONG LOW PRESSURE AREA THAT WILL MOVE ACROSS THE
REGION ON MONDAY.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 PM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
635 AM CDT Tue Mar 25 2014
.DISCUSSION...
ISSUED 253 AM CDT Tue Mar 25 2014
SHORT TERM...Today through Thursday
07z/2am radar imagery shows two bands of snow across central
Illinois...one along the I-55 corridor and one further west in the
Illinois River Valley. Based on radar timing tools and 05z HRRR,
snow will be east of I-57 by 12z, then will quickly exit into
Indiana by mid-morning. Will therefore hold on to low chance POPs
across the far E/SE KILX CWA through 15z, followed by dry
conditions across the board through the balance of the day. Sky
cover forecast will be a bit tricky today, as clearing immediately
behind the snow bands may be muddled by SCT-BKN clouds currently
upstream over Minnesota/northern Iowa. HRRR hints that this cloud
cover will filter southward into the area, resulting in a partly
sunny day. Main story will be the breezy and unseasonably cold
conditions. With temperatures hovering in the 30s and strong
northwesterly winds gusting to between 20 and 30mph, wind-chill
values will remain in the teens.
Clouds will clear out toward sunset as high pressure builds in
from the west. Thanks to clear skies and decreasing winds beneath
the ridge axis, a very cold night is in store with lows dipping
into the teens. High will quickly shift off to the east on
Wednesday allowing a warming trend to begin. Despite full
sunshine, will undercut numeric guidance by a couple of degrees
due to southeasterly component of return flow on back side of
departing high. Resulting high temperatures will remain in the
lower to middle 40s.
Models continue to markedly increase WAA Wednesday night, with all
solutions bringing rain showers into the area overnight. Think
this looks reasonable given strengthening low-level southerly flow
and moistening forecast soundings. In addition, precip coverage
will be enhanced by a lead short-wave ejecting northeastward out
of the Southern Plains. Have therefore bumped POPs to likely after
midnight. Thursday appears to be a windy and wet day, with
numeric guidance suggesting southerly winds gusting to around 30
mph. This will push highs well into the 50s. Increasing elevated
instability could lead to a few rumbles of thunder as well,
particularly as initial short-wave passes through the area. Main
convective event still looks likely for Thursday evening as cold
front pushes into central Illinois. Will continue with likely POPs
for showers and thunderstorms at that time.
LONG TERM...Friday through Monday
00z Mar 25 models are now in good agreement with timing of
departing front late Thursday night, resulting in a cooler and
drier day on Friday. Given model consensus, have removed shower
chances on Friday except across the far E during the morning.
Despite FROPA, a new fly-in-the-ointment has developed for the end
of the week. Both the GFS and ECMWF now develop a secondary
surface low along the trailing end of the front Friday night.
ECMWF had previously shown this feature on a few prior runs, but
never with any consistency. GFS on the other hand had always
advertised a clean FROPA with no secondary wave. GEM also shows
this wave, so given consensus among the three models, confidence
is growing that light precip may return to part of the area Friday
night. At this point, will focus low chance POPs across only the
southern CWA along/south of I-70 in closer proximity to the low
with dry conditions further north across the remainder of the
area. After that, upper heights rise considerably as ridge builds
across the central CONUS. As a result, temperatures will rise back
above normal, with readings climbing well into the 60s for Sunday
and Monday.
Barnes
&&
.AVIATION...
ISSUED 635 AM CDT Tue Mar 25 2014
Gusty northwest winds are expected across the central Illinois
terminals today in the wake of the overnight cold front. Gusts as
high as 25-30 kts are likely at times. Winds will die off this
evening and trend variable as high pressure builds into the area.
Expect VFR conditions to prevail through the 12Z TAF valid time.
Isolated streaks of clouds and even some flurries extend upstream
into the Upper Midwest. However, these features should remain isolated
and have not included them in the terminals at this time.
Bak
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
541 AM MDT TUE MAR 25 2014
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 416 AM MDT TUE MAR 25 2014
FORECAST CONCERN WILL BE THE FORECAST FROM WEDNESDAY INTO THURSDAY
NIGHT. SATELLITE SHOWING AN AMPLIFIED AND BLOCKY PATTERN FROM THE
EASTERN PACIFIC INTO NORTH AMERICA. ANOTHER COLD FRONT IS PUSHING IN
FROM THE NORTH AT THIS TIME.
AT JET LEVEL...OVERLAND THE MODELS WERE FINE. HOWEVER THE JET THAT
WILL BE AFFECTING THE AREA BEGINNING TOMORROW IS WELL OUT OVER THE
OCEAN AND IS VERY HARD TO GET A HANDLE ON. SATELLITE OBSERVATIONS
FROM OUT THERE WOULD INDICATE THE MODELS HAVE A PROPER HANDLE ON IT
AT THIS TIME WITH MAYBE THE UKMET DOING THE BEST. AT MID LEVELS...
SATELLITE WOULD INDICATE THE NAM WAS DOING A LITTLE BETTER WITH THE
COMPLICATED UPPER LOW APPROACHING THE PACIFIC NORTHWEST AND
SOUTHWEST CANADA. OTHER FEATURE OF INTEREST IS THE UPPER LOW NEAR
THE BAJA. HERE AND WOULD ALSO SAY OVERALL THAT THE CANADIAN WAS DOING
A LITTLE BETTER THAN GFS AND UKMET. THE NAM AND RUC WERE DOING A
LITTLE BETTER THAN THE ECMWF ON THE SURFACE WIND/PRESSURE FIELD.
NAM/GFS WERE DOING A LITTLE BETTER THAN THE ECMWF/CANADIAN ON THE LOW
LEVEL THERMAL FIELD.
TODAY/TONIGHT...UPPER JET MOVES RAPIDLY EAST OF THE AREA DURING THE
DAY. CURRENTLY HAVE SOME WEAK RETURNS WITH A FEW STATIONS REPORTING
FLURRIES. RADAR TRENDS AND LATEST SMALL GUIDANCE SUPPORT THIS
ACTIVITY BEING DONE BY 12Z AND WILL NOT INCLUDE IN THE MORNING
FORECAST. THICK CLOUD COVER HAS OVERSPREAD THE AREA. THIS HAS CAUSE
THE TEMPERATURES TO WARM CONSIDERABLY ABOVE THE DEWPOINTS. FORECAST
SOUNDINGS AND SMALL SCALE GUIDANCE INDICATE THAT NO FOG IS GOING TO
DEVELOP SO WILL REMOVE THAT FROM THE MORNING GRIDS.
PRESSURE GRADIENT AND 3 HOUR PRESSURE FALLS WOULD SUPPORT HAVING
BREEZY TO PROBABLY WINDY CONDITIONS...ESPECIALLY IN THE WESTERN
PORTION THIS AFTERNOON. HOW FAST IT CLEARS OUT WILL DETERMINE THE
MAXES. BELIEVE SKIES WILL CLEAR FAIRLY QUICKLY. NEWEST GUIDANCE
WOULD SUPPORT GOING WARMER. RECENTLY GUIDANCE HAS SHOWN A COOL BIAS
AS WELL. FOR TONIGHT...TIGHT GRADIENT AND SOUTHERLY WINDS/WARM
ADVECTION TONIGHT WOULD SUPPORT MILD CONDITIONS OVER MOST OF THE
AREA...ESPECIALLY IN THE EASTERN PORTION. I STILL MAY BE TOO COOL.
WEDNESDAY/WEDNESDAY NIGHT...BELIEVE MOST OF THE MODEL OUTPUT HAS
DRYLINE/SURFACE TROUGH TOO FAR EAST CONSIDERING THE FLOW ALOFT. IN
THIS INSTANCE LIKE THE ECMWF AND ITS WIND DIRECTION AND DEWPOINTS
COMBINED WITH THE SPEEDS THE NAM IS SHOWING. THE 00Z ECMWF IS MUCH
FURTHER WEST THAN ANY OTHER GUIDANCE. 06Z NAM CAME IN AND PULLED
THE DRY LINE/SURFACE TROUGH BACK FURTHER WEST. ALSO NEW NAM
DEWPOINTS MATCH VERY CLOSE WHAT THE ECMWF WAS INDICATING. PRESSURE
GRADIENT AND 3 HOUR PRESSURE FALLS WOULD SUPPORT WINDY CONDITIONS IN
AT LEAST THE EASTERN THIRD TO HALF OF THE AREA THROUGH THE DAY.
SO IN REGARDS TO FIRE WEATHER. THE DRIEST AIR WILL BE WEST OF THE
COLORADO BORDER. ALSO THAT LOOKS TO BE WHERE THE WEAKEST WINDS WILL
BE AS WELL. STRONGEST WINDS ARE FURTHER SOUTH AND EAST. CONSIDERING
AT THIS TIME RELATIVE HUMIDITIES WILL REMAIN ABOVE 20 PERCENT FOR
MOST OF THE AFTERNOON AND THE WINDS WILL NOT BE THERE...WILL NOT BE
ISSUING A WATCH. THE DAY SHIFT WILL NEED TO TAKE ANOTHER LOOK.
BY LATE TOMORROW THE MODELS HAVE THE LEFT FRONT QUADRANT TO THE
SOUTHWEST OF THE AREA. DRY LINE/SURFACE TROUGH WILL BE NEAR TO A
LITTLE WEST OF THE COLORADO BORDER. EVEN THOUGH LOW LEVEL MOISTURE
RETURN IS STILL MODEST...ONLY INTO THE LOWER TO MIDDLE 40S AT BEST...
THE MODELS ARE IN MORE AGREEMENT IN REGARDS TO THE INSTABILITY THAT
WILL BE IN PLACE. CONSIDERING THAT THE SHORTWAVE TROUGH WILL NOT
ARRIVE UNTIL LATER IN THE AFTERNOON AND THE SURFACE CONVERGENCE IS
FURTHER WEST...DELAYED THE ONSET OF THE THUNDERSTORMS AND PULLED
THEM FURTHER WEST. THE CAVEAT TO ALL THIS IS THE PASSAGE OF A
SHORTWAVE TROUGH EARLIER IN THE DAY. THAT MAY MESS THINGS UP FOR
THIS ENTIRE PERIOD.
DURING THE NIGHT A RATHER STRONG LEFT FRONT QUADRANT LOOKS TO BE
AFFECTING THE SOUTHERN HALF OF THE AREA. STRONG 700 MB SHORTWAVE
TROUGH AND ASSOCIATED PV ANOMALY START MOVING IN LATER IN THE
EVENING INTO THE OVERNIGHT HOURS. THE LIFT AND MOISTURE FROM THE
NEWER MODEL RUN SUPPORTED WHAT THE DAY SHIFT HAD IN THERE AND LEFT
IT ALONE. WHAT ENDS UP HAPPENING IS GETTING PRECIPITATION AHEAD OF
THE FEATURE WITH WRAP AROUND OCCURRING LATER IN THE NIGHT. LOOKS
LIKE MOST OF THE PRECIPITATION WILL REMAIN RAIN WITH SOME MIXTURE
POSSIBLE IN THE WEST LATE IN THE NIGHT.
BREEZY TO WINDY CONDITIONS DEVELOP BEHIND THE FRONT AND DEPARTING
SYSTEM.
THURSDAY/THURSDAY NIGHT...MAIN JET IS TO THE EAST OF THE AREA.
BREEZY TO WINDY CONDITIONS WILL CONTINUE THROUGH THE MORNING.
MODELS SHOW A HUGE SPREAD IN THE LOW LEVEL THERMAL FIELD DURING THIS
ENTIRE PERIOD. DOES NOT LIKE THERE WILL BE A CHANCE TO WARM UP A
LOT. SO WENT MORE TOWARD THE COOLER BUT NOT COLDEST SOLUTIONS. AGAIN
LOOKS LIKE A MIXTURE POSSIBLE EARLY IN THE DAY WITH MAYBE A COMPLETE
SWITCH BACK TO RAIN. THIS ROUND OF PRECIPITATION LOOKS DONE BY 18Z.
ALL THIS PRETTY MATCHES WHAT THE DAY SHIFT END THERE AND MADE LITTLE
TO NO CHANGES.
MODELS LOOK TO BRING ANOTHER SHORTWAVE TROUGH AND ANOTHER BATCH OF
PRECIPITATION IN DURING THE NIGHT. THETA-E LAPSE RATES NEAR ZERO
WILL BE IN PLACE AS STRONG MESOSCALE FORCING PLUS A STRONG PV
ANOMALY MOVE THROUGH BEGINNING LATE IN THE EVENING INTO THE
OVERNIGHT HOURS. SO ADJUSTED THE GRIDS IN REGARDS TO THIS TIMING.
A COMPLETE CHANGEOVER TO SNOW DOES NOT HAPPEN UNTIL LATE IN THE FAR
WEST. HOWEVER...BY THE TIME IT GETS COLD ENOUGH THERE MAY BE MUCH
MOISTURE AND LIFT. REMAINDER OF THE AREA WILL SEE A RAIN OR
RAIN/SNOW MIX.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 416 AM MDT TUE MAR 25 2014
THE EXTENDED WILL BE CHARACTERIZED BY A SERIES OF SHORTWAVE TROUGHS
MOVING THROUGH THE CWA AND A RIDGE THAT WILL MOVE INTO THE CENTRAL
PLAINS THIS WEEKEND. THE FIRST THING TO NOTE IS THE PRECIPITATION ON
FRIDAY MORNING. FRONTOGENESIS WEAKENS AND THE AREAS OF STRONGEST
LIFT PUSH EAST FAIRLY QUICKLY AROUND 12Z ACCORDING TO THE NAM AND
GFS. THEREFORE...DECIDED TO HAVE SILENT POPS IN THE EASTERN HALF OF
THE CWA ON FRIDAY MORNING TO ACCOUNT FOR ANY REMAINING PRECIPITATION
THAT MAY LINGER SINCE CONFIDENCE IS NOT HIGH ENOUGH TO ASSIGN A
HIGHER VALUE AT THIS TIME.
THE REMAINDER OF THE EXTENDED WILL REMAIN DRY AS THE UPPER LEVEL
RIDGE MOVES INTO THE PLAINS ON SATURDAY. THE RIDGE BEING IN PLACE
WILL ALLOW TEMPERATURES TO WARM UP QUITE NICELY OVER THE WEEKEND
WITH HIGHS ON SATURDAY IN THE UPPER 60S TO LOW 70S AND HIGHS ON
SUNDAY IN MID TO UPPER 70S APPROACHING 80 DEGREES. WHILE GETTING
INTO THE DETAILS IN THE EXTENDED IS OFTEN DIFFICULT DUE TO MODEL
SPREAD AND OTHER VARIABLES...IT LOOKS LIKE SOUTHWEST SURFACE WINDS
COULD BE HIGH ENOUGH AND RH VALUES COULD BE LOW ENOUGH ON SUNDAY
AFTERNOON FOR ELEVATED FIRE WEATHER. HOWEVER...THIS IS STILL FAR
ENOUGH OUT THAT THIS COULD CHANGE.
SOME MODELS SHOW THE STRONGEST SHORTWAVE TROUGH AFFECTING THE CWA ON
SUNDAY NIGHT. THIS SHORTWAVE TROUGH WILL MOVE THROUGH THE NORTHERN
PLAINS AND DROP A COLD FRONT THROUGH THE CWA SUNDAY NIGHT. BEHIND
THE FRONT...NORTH WINDS WILL INCREASE AND COULD BECOME QUITE GUSTY.
HOWEVER...AS PREVIOUSLY MENTIONED...THESE KINDS OF DETAILS ARE HARD
TO PIN DOWN THIS FAR OUT. DEPENDING ON HOW THIS
DEVELOPS...PRECIPITATION COULD ALSO CHANGE. DECIDED TO GO AHEAD AND
KEEP THE REST OF THE EXTENDED DRY FOR NOW BECAUSE OF MODEL
DISCREPANCIES. THEREFORE...THE THINGS TO TAKE AWAY FROM THE EXTENDED
ARE THAT IT WILL BE DRY AFTER FRIDAY MORNING AND WARM OVER THE
WEEKEND WITH A SLIGHT COOL DOWN ON MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 538 AM MDT TUE MAR 25 2014
FOR KGLD...MVFR CEILINGS WILL BE IN PLACE THROUGH MID MORNING.
AFTER VFR CONDITIONS ARE EXPECTED THROUGH THE REST OF THE PERIOD.
SOUTHERLY WINDS WILL BE GUSTY IN THE AFTERNOON. AFTER CALMING DOWN
BRIEFLY AFTER DARK...THOSE SOUTH WINDS/LOW LEVEL JET WILL INCREASE
AGAIN BY LATE IN THE NIGHT WITH GUSTS EXPECTED. FOR KMCK...VFR
CONDITIONS ARE EXPECTED THROUGH THE PERIOD. WINDS WILL BE VARIABLE
AND SHIFTING THROUGH THIS ENTIRE PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...ALW
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
416 AM MDT TUE MAR 25 2014
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 416 AM MDT TUE MAR 25 2014
FORECAST CONCERN WILL BE THE FORECAST FROM WEDNESDAY INTO THURSDAY
NIGHT. SATELLITE SHOWING AN AMPLIFIED AND BLOCKY PATTERN FROM THE
EASTERN PACIFIC INTO NORTH AMERICA. ANOTHER COLD FRONT IS PUSHING IN
FROM THE NORTH AT THIS TIME.
AT JET LEVEL...OVERLAND THE MODELS WERE FINE. HOWEVER THE JET THAT
WILL BE AFFECTING THE AREA BEGINNING TOMORROW IS WELL OUT OVER THE
OCEAN AND IS VERY HARD TO GET A HANDLE ON. SATELLITE OBSERVATIONS
FROM OUT THERE WOULD INDICATE THE MODELS HAVE A PROPER HANDLE ON IT
AT THIS TIME WITH MAYBE THE UKMET DOING THE BEST. AT MID LEVELS...
SATELLITE WOULD INDICATE THE NAM WAS DOING A LITTLE BETTER WITH THE
COMPLICATED UPPER LOW APPROACHING THE PACIFIC NORTHWEST AND
SOUTHWEST CANADA. OTHER FEATURE OF INTEREST IS THE UPPER LOW NEAR
THE BAJA. HERE AND WOULD ALSO SAY OVERALL THAT THE CANADIAN WAS DOING
A LITTLE BETTER THAN GFS AND UKMET. THE NAM AND RUC WERE DOING A
LITTLE BETTER THAN THE ECMWF ON THE SURFACE WIND/PRESSURE FIELD.
NAM/GFS WERE DOING A LITTLE BETTER THAN THE ECMWF/CANADIAN ON THE LOW
LEVEL THERMAL FIELD.
TODAY/TONIGHT...UPPER JET MOVES RAPIDLY EAST OF THE AREA DURING THE
DAY. CURRENTLY HAVE SOME WEAK RETURNS WITH A FEW STATIONS REPORTING
FLURRIES. RADAR TRENDS AND LATEST SMALL GUIDANCE SUPPORT THIS
ACTIVITY BEING DONE BY 12Z AND WILL NOT INCLUDE IN THE MORNING
FORECAST. THICK CLOUD COVER HAS OVERSPREAD THE AREA. THIS HAS CAUSE
THE TEMPERATURES TO WARM CONSIDERABLY ABOVE THE DEWPOINTS. FORECAST
SOUNDINGS AND SMALL SCALE GUIDANCE INDICATE THAT NO FOG IS GOING TO
DEVELOP SO WILL REMOVE THAT FROM THE MORNING GRIDS.
PRESSURE GRADIENT AND 3 HOUR PRESSURE FALLS WOULD SUPPORT HAVING
BREEZY TO PROBABLY WINDY CONDITIONS...ESPECIALLY IN THE WESTERN
PORTION THIS AFTERNOON. HOW FAST IT CLEARS OUT WILL DETERMINE THE
MAXES. BELIEVE SKIES WILL CLEAR FAIRLY QUICKLY. NEWEST GUIDANCE
WOULD SUPPORT GOING WARMER. RECENTLY GUIDANCE HAS SHOWN A COOL BIAS
AS WELL. FOR TONIGHT...TIGHT GRADIENT AND SOUTHERLY WINDS/WARM
ADVECTION TONIGHT WOULD SUPPORT MILD CONDITIONS OVER MOST OF THE
AREA...ESPECIALLY IN THE EASTERN PORTION. I STILL MAY BE TOO COOL.
WEDNESDAY/WEDNESDAY NIGHT...BELIEVE MOST OF THE MODEL OUTPUT HAS
DRYLINE/SURFACE TROUGH TOO FAR EAST CONSIDERING THE FLOW ALOFT. IN
THIS INSTANCE LIKE THE ECMWF AND ITS WIND DIRECTION AND DEWPOINTS
COMBINED WITH THE SPEEDS THE NAM IS SHOWING. THE 00Z ECMWF IS MUCH
FURTHER WEST THAN ANY OTHER GUIDANCE. 06Z NAM CAME IN AND PULLED
THE DRY LINE/SURFACE TROUGH BACK FURTHER WEST. ALSO NEW NAM
DEWPOINTS MATCH VERY CLOSE WHAT THE ECMWF WAS INDICATING. PRESSURE
GRADIENT AND 3 HOUR PRESSURE FALLS WOULD SUPPORT WINDY CONDITIONS IN
AT LEAST THE EASTERN THIRD TO HALF OF THE AREA THROUGH THE DAY.
SO IN REGARDS TO FIRE WEATHER. THE DRIEST AIR WILL BE WEST OF THE
COLORADO BORDER. ALSO THAT LOOKS TO BE WHERE THE WEAKEST WINDS WILL
BE AS WELL. STRONGEST WINDS ARE FURTHER SOUTH AND EAST. CONSIDERING
AT THIS TIME RELATIVE HUMIDITIES WILL REMAIN ABOVE 20 PERCENT FOR
MOST OF THE AFTERNOON AND THE WINDS WILL NOT BE THERE...WILL NOT BE
ISSUING A WATCH. THE DAY SHIFT WILL NEED TO TAKE ANOTHER LOOK.
BY LATE TOMORROW THE MODELS HAVE THE LEFT FRONT QUADRANT TO THE
SOUTHWEST OF THE AREA. DRY LINE/SURFACE TROUGH WILL BE NEAR TO A
LITTLE WEST OF THE COLORADO BORDER. EVEN THOUGH LOW LEVEL MOISTURE
RETURN IS STILL MODEST...ONLY INTO THE LOWER TO MIDDLE 40S AT BEST...
THE MODELS ARE IN MORE AGREEMENT IN REGARDS TO THE INSTABILITY THAT
WILL BE IN PLACE. CONSIDERING THAT THE SHORTWAVE TROUGH WILL NOT
ARRIVE UNTIL LATER IN THE AFTERNOON AND THE SURFACE CONVERGENCE IS
FURTHER WEST...DELAYED THE ONSET OF THE THUNDERSTORMS AND PULLED
THEM FURTHER WEST. THE CAVEAT TO ALL THIS IS THE PASSAGE OF A
SHORTWAVE TROUGH EARLIER IN THE DAY. THAT MAY MESS THINGS UP FOR
THIS ENTIRE PERIOD.
DURING THE NIGHT A RATHER STRONG LEFT FRONT QUADRANT LOOKS TO BE
AFFECTING THE SOUTHERN HALF OF THE AREA. STRONG 700 MB SHORTWAVE
TROUGH AND ASSOCIATED PV ANOMALY START MOVING IN LATER IN THE
EVENING INTO THE OVERNIGHT HOURS. THE LIFT AND MOISTURE FROM THE
NEWER MODEL RUN SUPPORTED WHAT THE DAY SHIFT HAD IN THERE AND LEFT
IT ALONE. WHAT ENDS UP HAPPENING IS GETTING PRECIPITATION AHEAD OF
THE FEATURE WITH WRAP AROUND OCCURRING LATER IN THE NIGHT. LOOKS
LIKE MOST OF THE PRECIPITATION WILL REMAIN RAIN WITH SOME MIXTURE
POSSIBLE IN THE WEST LATE IN THE NIGHT.
BREEZY TO WINDY CONDITIONS DEVELOP BEHIND THE FRONT AND DEPARTING
SYSTEM.
THURSDAY/THURSDAY NIGHT...MAIN JET IS TO THE EAST OF THE AREA.
BREEZY TO WINDY CONDITIONS WILL CONTINUE THROUGH THE MORNING.
MODELS SHOW A HUGE SPREAD IN THE LOW LEVEL THERMAL FIELD DURING THIS
ENTIRE PERIOD. DOES NOT LIKE THERE WILL BE A CHANCE TO WARM UP A
LOT. SO WENT MORE TOWARD THE COOLER BUT NOT COLDEST SOLUTIONS. AGAIN
LOOKS LIKE A MIXTURE POSSIBLE EARLY IN THE DAY WITH MAYBE A COMPLETE
SWITCH BACK TO RAIN. THIS ROUND OF PRECIPITATION LOOKS DONE BY 18Z.
ALL THIS PRETTY MATCHES WHAT THE DAY SHIFT END THERE AND MADE LITTLE
TO NO CHANGES.
MODELS LOOK TO BRING ANOTHER SHORTWAVE TROUGH AND ANOTHER BATCH OF
PRECIPITATION IN DURING THE NIGHT. THETA-E LAPSE RATES NEAR ZERO
WILL BE IN PLACE AS STRONG MESOSCALE FORCING PLUS A STRONG PV
ANOMALY MOVE THROUGH BEGINNING LATE IN THE EVENING INTO THE
OVERNIGHT HOURS. SO ADJUSTED THE GRIDS IN REGARDS TO THIS TIMING.
A COMPLETE CHANGEOVER TO SNOW DOES NOT HAPPEN UNTIL LATE IN THE FAR
WEST. HOWEVER...BY THE TIME IT GETS COLD ENOUGH THERE MAY BE MUCH
MOISTURE AND LIFT. REMAINDER OF THE AREA WILL SEE A RAIN OR
RAIN/SNOW MIX.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 416 AM MDT TUE MAR 25 2014
THE EXTENDED WILL BE CHARACTERIZED BY A SERIES OF SHORTWAVE TROUGHS
MOVING THROUGH THE CWA AND A RIDGE THAT WILL MOVE INTO THE CENTRAL
PLAINS THIS WEEKEND. THE FIRST THING TO NOTE IS THE PRECIPITATION ON
FRIDAY MORNING. FRONTOGENESIS WEAKENS AND THE AREAS OF STRONGEST
LIFT PUSH EAST FAIRLY QUICKLY AROUND 12Z ACCORDING TO THE NAM AND
GFS. THEREFORE...DECIDED TO HAVE SILENT POPS IN THE EASTERN HALF OF
THE CWA ON FRIDAY MORNING TO ACCOUNT FOR ANY REMAINING PRECIPITATION
THAT MAY LINGER SINCE CONFIDENCE IS NOT HIGH ENOUGH TO ASSIGN A
HIGHER VALUE AT THIS TIME.
THE REMAINDER OF THE EXTENDED WILL REMAIN DRY AS THE UPPER LEVEL
RIDGE MOVES INTO THE PLAINS ON SATURDAY. THE RIDGE BEING IN PLACE
WILL ALLOW TEMPERATURES TO WARM UP QUITE NICELY OVER THE WEEKEND
WITH HIGHS ON SATURDAY IN THE UPPER 60S TO LOW 70S AND HIGHS ON
SUNDAY IN MID TO UPPER 70S APPROACHING 80 DEGREES. WHILE GETTING
INTO THE DETAILS IN THE EXTENDED IS OFTEN DIFFICULT DUE TO MODEL
SPREAD AND OTHER VARIABLES...IT LOOKS LIKE SOUTHWEST SURFACE WINDS
COULD BE HIGH ENOUGH AND RH VALUES COULD BE LOW ENOUGH ON SUNDAY
AFTERNOON FOR ELEVATED FIRE WEATHER. HOWEVER...THIS IS STILL FAR
ENOUGH OUT THAT THIS COULD CHANGE.
SOME MODELS SHOW THE STRONGEST SHORTWAVE TROUGH AFFECTING THE CWA ON
SUNDAY NIGHT. THIS SHORTWAVE TROUGH WILL MOVE THROUGH THE NORTHERN
PLAINS AND DROP A COLD FRONT THROUGH THE CWA SUNDAY NIGHT. BEHIND
THE FRONT...NORTH WINDS WILL INCREASE AND COULD BECOME QUITE GUSTY.
HOWEVER...AS PREVIOUSLY MENTIONED...THESE KINDS OF DETAILS ARE HARD
TO PIN DOWN THIS FAR OUT. DEPENDING ON HOW THIS
DEVELOPS...PRECIPITATION COULD ALSO CHANGE. DECIDED TO GO AHEAD AND
KEEP THE REST OF THE EXTENDED DRY FOR NOW BECAUSE OF MODEL
DISCREPANCIES. THEREFORE...THE THINGS TO TAKE AWAY FROM THE EXTENDED
ARE THAT IT WILL BE DRY AFTER FRIDAY MORNING AND WARM OVER THE
WEEKEND WITH A SLIGHT COOL DOWN ON MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1048 PM MDT MON MAR 24 2014
VFR CONDITIONS FORECAST AT KGLD/KMCK THROUGH THE TAF PERIOD.
A BROKEN TO OVERCAST DECK OF MID CLOUDS WITH BASES FL060-100 WILL
PERSIST OVERNIGHT AT KMCK CONTINUING THRU 15Z TUESDAY. KGLD WILL
BE ON THE WESTERN FRINGE OF THIS DECK WITH BEST CIG POTENTIAL 08Z-
13Z. THIS CLOUD DECK WILL SLIDE OFF TO THE EAST TUESDAY MORNING.
SURFACE HIGH PRESSURE WILL MOVE FROM MONTANA INTO SOUTHERN
NEBRASKA BY 15Z TUESDAY. SURFACE WINDS WILL BE LIGHT- VARIABLE
OVERNIGHT...GRADUALLY BECOMING S-SE TUESDAY MORNING WITH SPEEDS
INCREASING TO 12-15 KTS BY AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...ALW
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1120 AM EDT TUE MAR 25 2014
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 322 AM EDT TUE MAR 25 2014
A NARROW BAND OF SNOW SHOWERS WILL CONTINUE TO PUSH THROUGH THE AREA
THROUGH THE EARLY HOURS THIS MORNING. THIS BAND OF SNOW SHOWERS IS
AT THE LEADING EDGE OF A REINFORCING SHOT OF ARCTIC AIR COMING IN
FROM THE NORTHWEST. SNOW SHOWERS WILL REMAIN LIKELY INTO THIS
AFTERNOON BEFORE THEY START TO DIMINISH AND MIGRATE CLOSER TO LAKE
MICHIGAN TONIGHT.
ANOTHER COLD DAY IS EXPECTED ON WEDNESDAY BEFORE A TREND OF MILDER
WEATHER CAN BE EXPECTED INTO LATER THIS WEEK. ANOTHER BATCH OF SNOW
WILL MOVE IN WEDNESDAY NIGHT BEFORE CHANGING TO RAIN ON THURSDAY AS
THE WARMER AIR MOVES IN. THIS RAIN COMBINED WITH SNOWMELT IS
EXPECTED TO INCREASE RIVER LEVELS ACROSS THE AREA. ANOTHER BATCH OF
COOLER AIR WILL COME IN FOR THE FRI AND SAT BEFORE MUCH WARMER
TEMPERATURES WILL BE POSSIBLE.
&&
.UPDATE...
ISSUED AT 1120 AM EDT TUE MAR 25 2014
STEEP LOW LEVEL LAPSE RATES... ENHANCED BY SMALL CLEAR SLOT BEHIND
THE DEPARTING COLD FRONT AND INCOMING H8 AIR AROUND -17C... WILL AID
IN THE DEVELOPMENT OF SOME FAIRLY INTENSE SNOW SHOWERS TODAY.
LAPS AND RAP FCST SOUNDINGS SHOW RELATIVELY DEEP MIXED LAYER UP TO
9000 FT AND EVEN SFC BASED CAPES OF 100-200 J/KG. THERE IS ANOTHER
PV ANOMALY SWINGING THROUGH THIS AFTERNOON TO AID IN LIFT. RADAR
LATE THIS MORNING HAS A VERY SPRINGLIKE LOOK WITH SMALL BUT
INTENSE OPEN CELLULAR CONVECTION.
HAVE UPDATED THE FCST TO REMOVE THE LIGHT INTENSITY QUALIFIER FOR
THE NUMEROUS SNOW SHOWERS THIS AFTERNOON AND TO FRESHEN WORDING AS
THE EARLIER SYNOPTIC EVENT HAS ENDED. ANY ADDITIONAL ACCUMULATIONS
THIS AFTERNOON WILL BE RELATIVELY MINOR SINCE THE HEAVIER SNOW
RATES WILL BE QUITE BRIEF IN DURATION... WITH SOME MELTING LIKELY
IN BETWEEN SNOW SHOW SHOWERS IN PEEKS OF LATE MARCH SUN.
ISSUED A SPECIAL WEATHER STATEMENT EARLIER TALKING ABOUT THE
HAZARD/IMPACT RELATED TO DRIVING INTO THESE POTENTIALLY SUDDENLY
BLINDING SNOW SQUALLS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 322 AM EDT TUE MAR 25 2014
THE FIRST ORDER OF BUSINESS IN THE SHORT TERM PORTION OF THIS FCST
PACKAGE IS DEALING WITH THE ONGOING BAND OF SNOW MOVING THROUGH THIS
MORNING. WE WILL THEN HAVE TO IDENTIFY TRENDS WITH REGARDS TO LAKE
EFFECT THROUGH WED...BEFORE TURNING OUR ATTENTION TO THE NEXT SYSTEM
FOR WED NIGHT AND THU.
WE ARE SEEING THE NICE...YET SHORT BURST OF SNOW MOVING THROUGH THE
CWFA EARLY THIS MORNING ALMOST AS EXPECTED. THE ONE THING THAT IS A
LITTLE DIFFERENT THAN EXPECTED IS THE EAST/WEST BAND OF SNOW THAT IS
IN PLACE JUST NORTH OF THE CWFA ALONG M-55. THIS IS JUST A LITTLE
FURTHER NORTH THAN EXPECTED...WHICH SHOULD HELP CUT BACK ON SNOW
ACCUMS A LITTLE ACROSS THE NORTH.
OTHERWISE...THE BAND OF SNOW MOVING THROUGH SRN LOWER MICHIGAN IS
PROGRESSING TO THE EAST NICELY THIS MORNING. IT IS QUICK ENOUGH THAT
ACCUMULATIONS WILL BE LIMITED TO AN INCH OR SO...ALTHOUGH IT WILL
HAPPEN IN A SHORT PERIOD OF TIME. WE CONTINUE TO EXPECT THIS WILL
EXIT THE CWFA TO THE SE AROUND 12Z PER THE LATEST EXTRAPOLATION OF
THE BACK OF THE LINE. THE SHORT DURATION AND THE CORE OF THE SNOW
FALLING BEFORE THE MORNING COMMUTE CONTINUES TO JUSTIFY HOLDING OFF
ON AN ADVISORY AT THIS TIME.
WE EXPECT TO SEE A SHORT BREAK OF THE SNOW SHOWERS IN THE WAKE OF
THE LINE WITH THE COLD FRONT THIS MORNING. WE DO EXPECT SCATTERED TO
NUMEROUS SNOW SHOWERS TO DEVELOP BY MID-LATE MORNING WITH THE
ARRIVAL OF THE SUPPORTING UPPER TROUGH EXPECTED TO MOVE THROUGH
EARLY THIS AFTERNOON. THE TROUGH...COMBINED WITH DIURNAL
INSTABILITY...AND SOME CONTRIBUTION OF HEAT/MOISTURE FROM LAKE
MICHIGAN WILL JUSTIFY THE RELATIVELY HIGHER CHCS OF SNOW SHOWERS.
THE STRONG LATE MARCH SUN WILL LIMIT ANY ACCUMS...ALTHOUGH A QUICK
COVERING OF THE GROUND COULD OCCUR DUE TO THE CONVECTIVE NATURE OF
THE SNOW SHOWERS EXPECTED.
SNOW SHOWERS WILL START DIMINISHING DURING THE SECOND HALF OF THE
AFTERNOON AS THE UPPER TROUGH AXIS SHIFTS EAST OF THE AREA. WE
EXPECT THEM TO DIMINISH AT INLAND LOCATIONS...AND FOR THEM TO
MIGRATE CLOSER TO THE LAKE. THEY SHOULD GRADUALLY DIMINISH
ALTOGETHER BY WED MORNING AS HIGH PRESSURE MOVES DIRECTLY OVERHEAD.
WE DO EXPECT SKIES TO GO AT LEAST PARTLY CLOUDY IF NOT CLEAR
OVERNIGHT. THIS WILL ALLOW FOR A COLD NIGHT...ESPECIALLY INLAND.
THIS SHOULD CONTINUE INTO WED AS THE FLOW ALOFT BECOMES
ANTI-CYCLONIC.
WE WILL SEE PCPN CHCS INCREASE ONCE AGAIN DURING THE NIGHT TIME
HOURS ON WED NIGHT....ESPECIALLY ACROSS THE NW PORTION OF THE CWFA.
RETURN FLOW WILL SET UP ON THE BACKSIDE OF THE HIGH AT THE SFC...AND
GRADUALLY A DEEP SW FLOW ALOFT WILL SET UP OVER THE AREA BY THU
MORNING AS THE UPPER RIDGE AXIS SHIFTS EAST. SOME DECENT MOISTURE
TRANSPORT WILL TAKE PLACE...ALLOWING PCPN TO DEVELOP. THE PCPN WOULD
START OUT AS MAINLY SNOW. A WARM NOSE ALOFT TRIES TO PUSH IN
OVERNIGHT WHICH WOULD SUPPORT A LOW CHC OF SOME FREEZING RAIN. WE
WET BULB DOWN PRETTY WELL...AND P-TYPE BECOMES A MAINLY RAIN OR SNOW
SCENARIO BY THU MORNING WITH NEARLY AN ISOTHERMAL PROFILE DEVELOPING
BY 12Z THU. IT WILL CONTINUE TO WARM THU MORNING...AND ALL PCPN
SHOULD TURN TO RAIN BY 18Z THU. A BETTER THREAT OF PCPN/RAIN WILL
COME THU AFTERNOON /AND BEYOND/ AS THE NOSE OF THE LLJ/MOISTURE
TRANSPORT MOVES UP INTO THE AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 322 AM EDT TUE MAR 25 2014
BETTER CONFIDENCE ON SOME RAIN FOR THURSDAY NIGHT. MODELS CONTINUE
TO SHOW LOW PRESSURE TRACKING THROUGH LOWER MICHIGAN THURSDAY
NIGHT. THIS SYSTEM WILL CONTAIN GULF MOISTURE. THE NOSE OF THE 850
MB LOW LEVEL JET IS FORECASTED TO PUSH THROUGH THE REGION THU
EVENING. SO RAIN IS EXPECTED THU NIGHT...ESPECIALLY EARLY. POPS
WERE INCREASED. WHILE SOME OF THE RAIN COULD BE HEAVY....IT
APPEARS THAT SINCE THE LOW LEVEL JET STEADILY PUSHES THROUGH...THAT
THE DURATION OF ANY HEAVY RAIN WILL BE LIMITED. STILL WITH SNOW
MELT...ESPECIALLY NORTH OF GRAND RAPIDS...WE WILL NEED TO MONITOR
THE POTENTIAL FOR HYDRO IMPACTS. I DID TREND THE FORECAST MORE
TOWARDS RAIN FOR THU NIGHT. THE COLDER AIR ON THE HIGH RES EURO
ARRIVES AFTER 12Z FOR NORTHWEST COUNTIES. THE COLDER GFS SOUNDINGS
DO NOT SUPPORT SNOW GIVEN UNSATURATED DGZ ASSOCIATED WITH THE DRY
SLOT AFTER 06Z FRI.
WE WILL HAVE TO MONITOR THE NEXT WAVE OF LOW PRESSURE RIDING UP THE
OH VALLEY SAT. THIS WOULD BE A SNOW SYSTEM IF IT DID REACH SW LOWER
MI. LOOKS LIKE THE TRACK IS TOO FAR SOUTH AND EAST TO IMPACT THE
REGION.
IMPRESSIVE WARM AIR ADVECTION DEVELOPS SUNDAY NIGHT INTO MONDAY.
THIS SYSTEM WILL BE TAPPING GULF MOISTURE. OVERALL I BUMPED UP
TEMPS AND POPS OVER GUIDANCE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 727 AM EDT TUE MAR 25 2014
SNOW SHOWERS MAY PERSIST INTO TONIGHT AS THE CLOUD DEPTH WILL
SUPPORT THIS...WHICH COULD LEAD TO BRIEF IMPACTS. SO WILL KEEP
THEM IN THE FORECAST. RECENT RADAR TRENDS DOES SHOW SOME
DEVELOPING SNOW SHOWERS NORTH OF GRAND RAPIDS. THESE COULD CLIP
KLAN WITH IFR CONDITIONS. ADDITIONAL SNOW SHOWERS DEVELOPING
AROUND KBIV COULD ARRIVE AT KAZO IN THE NEXT HR OR TWO. WIND WILL
LIKELY INCREASE THIS MORNING AND PERSIST THIS AFTERNOON...HOWEVER
MOST GUSTS SHOULD STAY UNDER 25 KNOTS.
&&
.HYDROLOGY...
ISSUED AT 330 PM EDT MON MAR 24 2014
HAVE CANCELLED THE FLOOD WARNING FOR THE MAPLE RIVER AT MAPLE
RAPIDS. CURRENTLY 11 FLOOD ADVISORIES REMAIN. LIMITED SNOWMELT AND
LIMITED ADDITIONAL PRECIPITATION SHOULD ALLOW STEADY OR FALLING
LEVELS ACROSS THE AREA THROUGH WEDNESDAY.
CONFIDENCE IS GROWING THAT A SIGNIFICANT SHIFT TO MUCH WARMER AND
WETTER CONDITIONS WILL COMMENCE THURSDAY AND LAST WELL INTO NEXT
WEEK. SOME LONG RANGE COMPUTER MODELS PREDICT THAT LONG TERM
PRECIPITATION TOTALS OF A COUPLE INCHES OR MORE ARE POSSIBLE BY THE
END OF NEXT WORK WEEK. AT THE SAME TIME...HIGH TEMPERATURES NEXT
WORK WEEK COULD REMAIN WELL IN THE 50S.
FOR AREAS ALONG AND NORTH OF THE MUSKEGON RIVER BASIN...SNOW PACK IS
SIGNIFICANTLY GREATER WITH SNOW WATER EQUIVALENT OF 3 INCHES OR MORE
OVER A LARGE AREA. THIS COMBINED WITH THE EXPECTED CHANGE IN THE
WEATHER WOULD MEAN SIGNIFICANT RISES TO AREA RIVERS. THIS COULD BE
EXACERBATED FURTHER IF ICE JAMS DEVELOP. THE COOPERATIVE OBSERVER IN
SCOTTVILLE REPORTED THAT THE PERE MARQUETTE RIVER HAS ALREADY BEEN
OPEN SINCE LAST WEEK. HOWEVER...ICE WAS STILL PRESENT FARTHER
NORTH NEAR LUDINGTON AND IN PERE MARQUETTE LAKE. WE ARE WAITING TO
HEAR BACK FROM OTHER OBSERVERS ABOUT THE EXTENT OF ICE COVERAGE ON
THE MUSKEGON AND CHIPPEWA RIVERS.
FOR THE GRAND AND KALAMAZOO RIVER BASINS...THERE IS FAR LESS
SNOWPACK AND RIVERS ARE ESSENTIALLY ICE FREE. HOWEVER...IT IS
POSSIBLE THAT SIGNIFICANTLY MORE RAIN COULD FALL OVER THIS AREA WITH
THE PATTERN CHANGE...SO ALL RIVERS ACROSS SOUTHWEST LOWER MICHIGAN
WILL NEED TO BE MONITORED CLOSELY OVER THE NEXT SEVERAL DAYS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...MEADE
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...MJS
AVIATION...MJS
HYDROLOGY...TJT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
729 AM EDT TUE MAR 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM EDT TUE MAR 25 2014
LATEST 08Z WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL
RIDGE OVER WRN NOAM AND A TROUGH FROM HUDSON BAY THROUGH MUCH OF THE
ERN CONUS. A SHORTWAVE ROTATING INTO WRN LAKE SUPERIOR PUSHED AN
ARCTIC COLD FRONT THROUGH WRN UPR MI EARLY THIS MORNING. NW OF LAKE
SUPERIOR IN THE WAKE OF THE FRONT...TEMPS ARE GENERALLY AT OR BELOW
ZERO. THIS COLDER AIR MOVING ACROSS LAKE SUPERIOR HAS GENERATED SOME
SCT -SHSN DOWNWIND OF THE LAKE IN A NW FLOW.
TODAY...AS THE SFC HIGH PRESSURE RIDGE AND ASSOC SUBSIDENCE BUILD
INTO THE WRN LAKES LATE THIS MORNING INTO THE AFTERNOON...SOUNDINGS
DRY FM 850-700 MB AND WINDS BACK WRLY...EXPECT LAKE SHSN TO DIMINISH
WITH ACCUMULATIONS GENERALLY AN INCH OR LESS. WITH 925/850 MB TEMPS
ONLY TO AROUND -18/-23C...TEMPS MAY STRUGGLE TO REACH THE LOWER TO
MID TEENS ALONG LAKE SUPERIOR...MORE THAN 20 DEGREES BELOW SEASONAL
AVERAGES.
TONIGHT...A HIGH PRESSURE RIDGE MOVING OVER THE UPPER GREAT LAKES
REGION WILL LEAD TO ANOTHER VERY COLD NIGHT TONIGHT ACROSS THE AREA.
WITH WINDS BACKING WSW WOULD NOT THINK LINGERING LAKE CLOUDS SHOULD
NOT BE A FCST CONCERN. THUS...WOULD EXPECT CLEARING SKIES AND IDEAL
RADIATIONAL COOLING CONDITIONS UNDER LIGHT WINDS. SINCE PWAT VALUES
ARE EXPECTED AROUND 30 PERCENT OF NORMAL...CONTINUED TO FCST MIN
TEMPS BLO GUIDANCE...ESPECIALLY IN THE TRADITIONAL INTERIOR COLD
SPOTS. LOOK FOR LOWS BELOW ZERO OVER PRETTY MUCH ALL OF THE U.P. AND
IN THE TEENS BELOW ZERO OVER THE INTERIOR. BASED OFF THE TRENDS IN
THE LONGER RANGE MODELS...THIS WILL LIKELY BE THE LAST REALLY COLD
NIGHT ACROSS THE REGION THIS SEASON.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 522 AM EDT TUE MAR 25 2014
S WINDS OF WEDNESDAY WILL HELP RAISE TEMPS ABOUT 10F HIGHER THAN
WHAT WILL BE EXPERIENCED TODAY ACROSS THE CWA...ESPECIALLY W AND N.
THIS WILL BE DESPITE SNOW NEARING FROM THE NW. KEPT A SLIGHT CHANCE
FAR W BY LATE AFTERNOON...ALTHOUGH THE TREND IS TO SLOW DOWN THE
POPS EVEN MORE.
ANOTHER DAY CLOSER TO OUR WEDNESDAY NIGHT THROUGH THURSDAY EVENING
EVENT. WHILE FCST SOLUTIONS HAVE COME A BIT MORE IN LINE...THEY
COULD BE BETTER. EXPECT SIGNIFICANT IMPROVEMENTS AT THE DISTURBANCE
MOVES FROM THE PACIFIC OVER THE BETTER SAMPLED/MODELED CONTINENTAL
U.S. WILL CONTINUE TO MINIMIZE THE USE OF THE NAM PAST 18Z THURSDAY
AS IT STILL IS AN OUTLIER WITH REGARDS TO THE STRENGTHENING OF THE N
EXTENT OF THE LOW AND IS QUICKEST TO SHIFT IT TO E QUEBEC THURSDAY
EVENING. WHILE THE 18Z GFS LINED UP BETTER WITH THE NEW 00Z RUN OF
THE ECMWF...THE 00Z GFS CONTINUED WITH THE QUICKER SOLUTION AGAIN.
THE CONSENSUS IS TO HAVE THE LOW SITUATED OVER THE CENTRAL PLAINS AT
06Z THURSDAY...WITH THE INVERTED TROUGH STRETCHING UP THROUGH N MN
AND W LAKE SUPERIOR. THE WEAKENING LOW WILL THEN MOVE ACROSS IA AND
S WI BY 00Z FRIDAY...BEFORE CROSSING LOWER MI OVERNIGHT. AS NOTED
ABOVE THE GFS HITS THE GAS ON THIS ONE...MOVING E OF LAKE HURON BY
12Z FRIDAY...WHILE THE ECMWF IS OVER S LOWER MI AND CENTRAL LAKE
HURON.
WHILE EXPECTED TO BE ALL SNOW THROUGH 12Z THURSDAY...THE POTENTIAL
EXISTS FOR SOME MIXING IN OF RAIN OR SLEET ALONG THE WI BORDER. THE
FOCUS FOR HEAVY WET SNOW WILL BE OVER THE TIP OF THE KEWEENAW
PENINSULA WEDNESDAY NIGHT.
TEMPS WERE RAISED SLIGHTLY FOR THURSDAY MORNING /STILL IN THE 20S/.
THEY SHOULD QUICKLY RISE ABOVE 32F AFTER 12Z...DIMINISHING THE NEED
FOR FREEZING RAIN IN THE FCST. AS A RESULT...IT LOOKS TO BE A MAINLY
RAIN OR SNOW EVENT. WILL KEEP THE MENTION OF MODERATE WET SNOW...AND
MIXED PRECIP IN THE HWO. CONTINUE TO EXPECT THE MOST SNOW N AS WARM
AIR SURGES IN FROM THE S. RAIN MAY RUN ACROSS MUCH OF THE
CWA...EXCLUDING THE KEWEENAW PENINSULA WITH THE BEST CHANCE
STRETCHING FROM WATERSMEET TO ESC AND ISQ FROM 15-21Z THURSDAY. FOR
THURSDAY THROUGH THURSDAY NIGHT 3-6IN OF SNOW WILL BE POSSIBLE
ACROSS MUCH OF THE CWA...WITH MORE LIKE 2-3IN ACROSS MENOMINEE
COUNTY.
ANOTHER CONUNDRUM IS WHEN TO DIMINISH POPS. YES COLD AIR WILL BE
RUSHING IN BEHIND THE EXITING LOW THURSDAY NIGHT...BUT THE ECMWF
ONLY HAS TEMPS FALLING TO AROUND -9C BY 12Z FRIDAY ON FAVORABLE N
WINDS. WITH THE MAIN SHORTWAVE EXITING E UPPER MI AT THAT TIME AND
ZONAL FLOW ALOFT...THE COLDEST AIR WILL REMAIN ACROSS ONTARIO. DRY
HIGH PRESSURE OVER S CANADA AND THE N PLAINS WILL SLOWLY EDGE IN FOR
LATE FRIDAY AFTERNOON THROUGH THE DAY SATURDAY...WITH LITTLE TO NO
SNOW ANTICIPATED.
AN ELONGATED TROUGH EXTENDING FROM THE MAIN SFC-500MB LOW OVER
HUDSON BAY SUNDAY WILL SHIFT ACROSS UPPER MI...BRINGING THE NEXT
CHANCE RAIN AND SNOW TO THE CWA...BUT NOT BEFORE TEMPS BRIEFLY WARM
INTO THE 40S SUNDAY AFTERNOON.
INCREASED POPS FOR DAY 6/MONDAY AS THE NEXT SFC LOW TRACKS FROM THE
N AND CENTRAL PLAINS SUNDAY AFTERNOON TO THE UPPER GREAT LAKES BY
12Z MONDAY. COMPARING THE 00Z RUNS...THE GFS HAS THE 996MB LOW NEAR
IWD...WHILE THE ECMWF CENTERS THE LOW ACROSS IA. WITH EITHER
SOLUTION...THE BEST CHANCE OF PRECIP LOOKS TO BE W UPPER MI. HAVE
ADDED LIKELY POPS FOR THE KEWEENAW PENINSULA FOR THE DAY MONDAY. AS
FOR SPECIFICS...WE WILL NEED TO WAIT. THE N SOLUTION WOULD BRING
MAINLY RAIN TO THE CWA...WHILE THE ECMWF WOULD RESULT IN MOSTLY
SNOW. WILL KEEP A MIX IN FOR NOW WITH THE BEST CHANCE OF SNOW NW
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 717 AM EDT TUE MAR 25 2014
SCT LAKE EFFECT -SHSN IN THE WAKE OF AN ARCTIC FRONT WILL CONTINUE TO
PRODUCE MVFR TO OCCASIONAL IFR CONDITIONS ACROSS THE TAF SITES THIS
MORNING. MVFR CIGS AND OCCASIONAL FLURRIES WILL PERSIST INTO THE
AFTERNOON HRS IN A NW FLOW...BUT THEN LOOK CONDITIONS TO IMPROVE TO
VFR TONIGHT AS WINDS BACK WSW. IMPROVEMENT WILL BE SLOWER AT KCMX
WITH UPSLOPE/ONSHORE WRLY FLOW INITIALLY EXPECTED THIS EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 455 AM EDT TUE MAR 25 2014
EXPECT NW WINDS 20 TO 30 KTS TODAY IN THE WAKE OF AN ARCTIC COLD
FRONT...WITH THE HIGHEST GUSTS OVER THE EASTERN HALF OF LAKE
SUPERIOR. WINDS WILL QUICKLY DIMINISH TONIGHT AND WEDNESDAY AS
ANOTHER HIGH PRESSURE RIDGE MOVES OVER THE AREA. A LOW PRESSURE
SYSTEM DEVELOPING IN THE CENTRAL PLAINS ON WEDNESDAY NIGHT AND
THURSDAY WILL MOVE THROUGH THE GREAT LAKES REGION LATE THURSDAY
NIGHT AND FRIDAY. EXPECT NRLY WINDS 20 TO 30 KTS ON THE BACK SIDE OF
THE LOW THU NIGHT INTO FRI MORNING WITH THE STRONGEST WINDS OVER ERN
LAKE SUPERIOR. WINDS WILL QUICKLY DIMINISH FM THE WEST FRI AFTERNOON
INTO SAT AS HIGH PRESSURE BUILDS OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KF
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
626 AM EDT TUE MAR 25 2014
.SYNOPSIS...
A CHILLY RAIN WILL OVERSPREAD THE AREA TODAY AS DEEPENING LOW
PRESSURE OFFSHORE TRACKS NORTHEAST OFF OUR COAST. THE RAIN WILL
TAPER OFF LATE TONIGHT FOLLOWED BY WINDY AND COLDER CONDITIONS
AS THE LOW DEEPENS AND CANADIAN HIGH PRESSURE BUILDS FROM THE
WEST. NEAR TO BELOW FREEZING TEMPERATURES ARE EXPECTED EARLY ON
WEDNESDAY AND AGAIN THURSDAY. A WARMING TREND WILL PREVAIL LATE
IN THE WEEK INTO NEXT WEEKEND...WITH A WEAK COLD FRONT POSSIBLY
CROSSING THE AREA EARLY ON SUNDAY. FAIR AND DRY EARLY NEXT WEEK
AS HIGH PRESSURE MOVES OVER THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 626 AM TUESDAY...A STEADY STRATIFORM RAINFALL EARLY THIS
MORNING IS GRADUALLY OVER-TAKING THE DRY LOW-LVL AND MID-LVL
AIR AS MORE SITES ARE REPORTING -RA AT 10Z/6AM. INITIALLY THE
COAST REMAINS FAVORED FOR PCPN...THEN A GOOD CHANCE AREA-WIDE
AS THE UPPER TROUGH PUSHES THROUGH IN THE AFTERNOON. NO MAJOR
CHANGES EXPECT FINE-TUNING THE DEWPOINT AND TEMPERATURE TRENDS AS
EVAPORATIVE COOLING TAKES PLACE THIS MORNING. THE PREVIOUS EARLY
MORNING DISCUSSION FOLLOWS.
A LOW PRESSURE CENTER ROUGHLY 300 MILES SOUTH OF CAPE FEAR EARLY
THIS MORNING WILL TRACK TO THE NE AND DEEPEN RAPIDLY TODAY...TO
APPROXIMATELY A 997 MB LOW 250 MILES EAST OF CAPE FEAR BY 21Z/5PM.
THE BOMBING SURFACE LOW ALTHOUGH WELL OFFSHORE...IN TANDEM WITH AN
APPROACHING TROUGH/COOL POOL ALOFT...WILL SET OFF PRECIPITATION
TODAY. INITIALLY STRATIFORM RAIN ACROSS OUR EASTERN HALF...WILL
TRANSITION TO MORE SHOWERY TYPE PRECIPITATION AREA-WIDE INTO
AFTERNOON AS THE UPPER TROUGH TRAVERSES THE REGION.
NORMALLY AN UPPER TROUGH IN SPRING RAISES A FLAG TO INTERROGATE
THE SEVERE WEATHER POTENTIAL. IN THIS CASE ALL OF THE FAVORABLE
INGREDIENTS REMAIN LINKED TO THE SURFACE FEATURE OFFSHORE. COOL
LOW-LEVELS OVER LAND AND LOW DEWPOINTS SHOULD PREVENT ROBUST
CONVECTION. HAIL SHOWERS THIS TIME OF YEAR BECOME MORE COMMON
BUT AM NOT SEEING THE VERTICAL VELOCITIES TODAY SUPPORTING THIS.
A FREEZE WATCH HOISTED FOR ALL ZONES FOR EARLY WEDNESDAY MORNING.
CONFIDENCE IS NOT HIGH THAT ALL ZONES WILL DROP BELOW 32 DEGREES
SINCE LOW-LEVEL WINDS WILL BE ELEVATED...AND RESIDUAL CLOUDS MAY
LINGER LATE IN THE NIGHT. IT APPEARS THE BEST CHANCE OF FREEZING
IS INLAND...WHILE CLOSER TO THE COAST...CONFIDENCE LEVEL FALLS.
THUS A WATCH IS IN EFFECT TO ALLOW THE 12Z MODEL DATA SUITE TO
HOPEFULLY PROVIDE ADDITIONAL RESOLUTION IN SEGMENTING A WARNING
VERSUS NO FREEZE WARNING. COUPLING IN WIND...THE APPARENT TEMPS
OR WIND-CHILLS...WILL FALL INTO THE LOW TO MID 20S PRIOR TO AND
THROUGH DAYBREAK ON WEDNESDAY.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 345 AM TUESDAY...THE MAIN EMPHASIS OF THE SHORT TERM WILL BE
THURSDAY MORNING WHEN ARCTIC HIGH PRESSURE SETTLES DIRECTLY
OVERHEAD. THIS COURTESY OF A RELATIVELY DEEP ALBEIT PROGRESSIVE
EAST COAST TROUGH.
GUIDANCE HAS IF ANYTHING JOGGED DOWN A BIT AS HAS THE OFFICIAL
FORECAST. MUCH LIKE A COUPLE OF WEEKS AGO WHEN GUIDANCE WAS VERY
CONSISTENT FOR SEVERAL CYCLES/DAYS...THERE APPEARS TO BE NO
MITIGATING FACTORS FOR A SIGNIFICANT LATE SEASON FREEZE. RETURN FLOW
CONTINUES TO SET UP LATER LATER THURSDAY WITH WHAT SEEMS TO BE A
GOOD SEA FOG SIGNAL FROM THE GFS. ONE FINAL NOTE...WITH THE
AFOREMENTIONED CONFIDENCE SIGNALS FOR A FREEZE...WOULD NORMALLY
ISSUE A NPW BUT WILL HAVE TO LET A MORE MARGINAL EVENT TRANSPIRE FOR
WEDNESDAY A.M.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 345 AM TUESDAY...ZONAL FLOW ALOFT CONTINUES TO ADVERTISE ONE SYSTEM
MOVING ACROSS THE TENNESSEE VALLEY SATURDAY/EARLY SUNDAY. GUIDANCE
HAS COME INTO SLIGHTLY BETTER AGREEMENT THIS MORNING ON THIS
SCENARIO. CONTINUED TO ADVERTISE POPS FOR FRIDAY AS WELL WITH LOW
LEVEL CONVERGENCE AND PRE FRONTAL TROUGH. I DID ADD SLIGHT COVERAGE
OF THUNDER AS WELL. MORE CONFIDENCE IN DRY CONDITIONS SUNDAY AND
MONDAY. TEMPERATURE GUIDANCE HAS TRENDED DOWN A LITTLE WITH FOR
THESE DAYS AS HAS THE OFFICIAL FORECAST.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
AS OF 06Z...MID LEVEL CIGS ARE SPREADING ACROSS THE CWA TONIGHT AS
SURFACE LOW PRESSURE ORGANIZES OFF THE FLORIDA COAST. EARLIER
FORECAST APPEARS ON TRACK AS THE LATEST HRRR RUNS INDICATE RAIN WILL
SPREAD UP THE COAST FROM SOUTH TO NORTH EARLY THIS MORNING. HAVE
NUDGED THE TIMING OF PCPN BACK A BIT WITH THIS TAF ISSUANCE...BUT
STILL EXPECT KMYR/KCRE TO SEE -RA BEFORE 12Z. WITH THE OFFSHORE
TRACK OF THE LOW...EXPECT PCPN AND MVFR CIGS TO BE FOCUSED ALONG THE
COAST. HAVE INCLUDED TEMPO MVFR FOR THE COASTAL TERMS IN THE LATE
MORNING/EARLY AFTERNOON AS RAIN WILL HELP TO LOWER CIGS. E-NE WINDS
5-10 KTS THIS MORNING WILL BECOME NORTHWEST AFTER 18Z AS THE LOW
PROGRESSES FURTHER UP THE COAST. COULD SEE NORTHWEST WIND GUSTS OF
15-20 KTS BY LATE AFTERNOON/EARLY EVENING ON THE BACKSIDE OF THE
LOW. CONDITIONS WILL IMPROVE TO VFR FROM SOUTHWEST TO NORTHEAST THIS
EVENING...BECOMING VFR AT ALL SITES SHORTLY AFTER 00Z WEDNESDAY.
EXTENDED OUTLOOK...VFR ON WEDNESDAY AND THURSDAY. CHANCE OF SHOWERS
WITH TEMPO MVFR CONDITIONS POSSIBLE ON FRIDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 626 AM TUESDAY...GALE FLAGS RAISED FOR RAPIDLY INTENSIFYING
NW WINDS LATE THIS AFTERNOON THROUGH TONIGHT AS A POWERFUL AND
RAPIDLY DEEPENING SURFACE LOW PASSES WELL EAST OF THE COASTAL
WATERS. ITS INTERACTION WITH APPROACHING CANADIAN HIGH PRESSURE
WILL DRIVE 25-40 KT WINDS FROM THE NW TONIGHT...HIGHEST OFFSHORE.
HIGHEST SEAS AS WELL OFFSHORE IN THE NW WIND TRAJECTORY. THE OCEAN
WILL BECOME DANGEROUS LATER TODAY AS THE NW WIND RIPS ACROSS
STRONG SE WAVE ENERGY...MAKING FOR A PITCHY AND TUMULTUOUS SEA
BEHAVIOR. MARINERS ARE ADVISED TO REMAIN IN PORT TONIGHT. TSTMS
SHOULD REMAIN CONFINED TO THE GULF STREAM THROUGH EARLY WEDNESDAY.
SEA HEIGHTS PEAKING 4 TO 8 FT TONIGHT...BUT DROPPING TO 3 TO 6 FT
INTO FIRST LIGHT OF WEDNESDAY.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 345 AM TUESDAY...MUCH LIKE THE PUBLIC PART OF THE FORECAST
GUIDANCE...WINDS AND SEAS REMAIN RELATIVELY UNCHANGED. STILL EXPECT
RUGGED CONDITIONS FOR MOST OF THE DAY WEDNESDAY AS SEAS WILL REMAIN
CHURNED UP AS WINDS DIMINISH.
INITIAL WIND SPEEDS WILL BE 20-25 KNOTS FROM THE NORTHWEST
DECREASING TO 10-15 BY MID EVENING. BY THURSDAY WINDS DROP EVEN
FURTHER AS SURFACE HIGH PRESSURE DRIFTS DIRECTLY OVERHEAD. EXPECT
SPEEDS OF TEN KNOTS OR LESS. LATER THURSDAY WINDS SLOWLY RECOVER TO
10-15 KNOTS THIS TIME FROM THE SOUTHEAST.
SEAS WILL CERTAINLY BE MORE ROBUST ACROSS THE OUTER PORTIONS OF THE
COASTAL ZONES WITH THE OFFSHORE FLOW. EXPECT 3-5 FEET WITH
POSSIBLE SIX FOOTERS FOR MOST OF THE DAY WITH HEIGHTS DROPPING
DRAMATICALLY THURSDAY.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 345 AM TUESDAY...WINDS WILL INITIALLY BE FROM THE SOUTH AT
A FAIRLY DECENT CLIP...15-20 KNOTS AND THERE MAY BE SOME SEA FOG
TO CONTEND WITH AS WELL. WITH AN INITIAL SURFACE SYSTEM LOSING
SOME STRENGTH...WINDS ACTUALLY DECREASE SLIGHTLY FOR SATURDAY
WHILE SWITCHING TO THE NORTH VERY LATE. NOT A STRONG SURGE OF COLD
AIR WITH THIS ONE KEEPING SPEEDS RELATIVELY LIGHT. SEAS ARE 3-5
FEET EARLY WITH THE PERSISTENCE AND STRENGTH OF THE RETURN FLOW
DIMINISHING A BIT WITH WIND SPEEDS LATER.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FREEZE WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING FOR
SCZ017-023-024-032-033-039-053>056.
NC...FREEZE WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING FOR
NCZ087-096-099-105>110.
MARINE...GALE WARNING FROM 6 PM THIS EVENING TO 6 AM EDT WEDNESDAY FOR
AMZ250-252-254-256.
&&
$$
SYNOPSIS...MJC
NEAR TERM...MJC
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...MJC/MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
922 AM EDT TUE MAR 25 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS EAST THROUGH THE OHIO VALLEY
TODAY. A LARGE AREA OF HIGH PRESSURE WILL BUILD WEST OF THE AREA
TONIGHT AND CROSS THE OHIO VALLEY ON WEDNESDAY. THE NEXT COLD
FRONT TO CROSS THE REGION WILL SEE RAIN AND MILD TEMPERATURES
OVERSPREAD THE OHIO VALLEY BEFORE IT PASSES ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COLD FRONT CURRENTLY PUSHING INTO NORTHWEST INDIANA WILL WORK
EAST ACROSS OUR AREA THROUGH THIS AFTERNOON. WE ARE ALREADY SEEING
FAIRLY WIDESPREAD SNOW SHOWER ACTIVITY ASSOCIATED WITH THIS BACK
ACROSS INDIANA. AS DAYTIME HEATING DEVELOPS...LOW LEVEL LAPSE RATES
WILL CONTINUE TO INCREASE THROUGH LATE MORNING/EARLY AFTERNOON.
THE 06Z NAM AND LATEST RAP RUNS ARE ALSO INDICATING A NARROW AXIS
OF WEAK ELEVATED INSTABILITIES PROGRESSING EAST ACROSS OUR AREA
THROUGH THIS AFTERNOON. THUS...EXPECT CONVECTIVE SNOW SHOWER
ACTIVITY TO BECOME EVEN MORE WIDESPREAD THROUGH LATE MORNING AND
INTO THIS AFTERNOON. THINK ALL AREAS WILL AT LEAST SEE SOME PCPN SO
WILL GO AHEAD AND BUMP UP POPS TO CATEGORICAL. WOULD EXPECT THE
POSSIBILITY FOR VISIBILITIES TO BRIEFLY DROP DOWN BELOW A QUARTER
OF A MILE IN THE HEAVIER SNOW SHOWERS. SOME QUICK DUSTING TO HALF
INCH ACCUMULATIONS WILL BE POSSIBLE WITH THESE HEAVIER SNOW
SHOWERS...PRIMARILY ON GRASSY AREAS AND ELEVATED SURFACES. ROAD
TEMPERATURES ARE CURRENTLY A FEW DEGREES ABOVE FREEZING ACROSS THE
AREA...SO WOULD EXPECT THE PRIMARY TRAVEL CONCERN TO BE THE LOWER
VISIBILITIES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
DROPPED LOW TEMPERATURES TONIGHT BY A FEW DEGREES WITH THE HIGH
BUILDING IN RAPIDLY FROM THE WEST AND A STRONG COLD PUSH. AM NOT
EXPECTING A LOT OF FRESH SNOW COVER OTHERWISE I WOULD HAVE CUT
LOWS EVEN FURTHER. MID TO UPPER TEENS SHOULD BE A FAIRLY UNIFORM
MIN TEMPERATURE TONIGHT OVER MUCH OF THE REGION AS SKIES CLEAR.
NORTH FLOW ON WEDNESDAY WILL COMPETE WITH SOME INCREASING HIGH
CLOUDS IN THE LATTER PART OF THE DAY AS THE AXIS OF HIGH PRESSURE
CROSSES THE REGION. FLOW WILL TURN SOUTH WEDNESDAY NIGHT AND
TEMPERATURES WILL THEN SEE A MARKED INCREASE FOR THE NEXT SEVERAL
PERIODS. MOISTURE WILL ALSO BE ON THE INCREASE THROUGH THURSDAY
AHEAD OF THE NEXT FROPA ON FRIDAY.
AS THE MOISTURE PULLS INTO THE REGION THURSDAY...THE THREAT FOR
SOME SHOWERS WILL INCREASE LATE IN THE DAY AND PARTICULARLY
OVERNIGHT IN NORTHWESTERN CWA...SPREADING EAST AS THE FRONT
APPROACHES. HAVE RAMPED UP THE POPS OVERNIGHT AS A STRONG LLJET
OF 50-60KT STREAMS GULF MOISTURE INTO THE REGION.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
WILL RAMP UP POPS TO LKLY WITH EXPECTED FROPA FRIDAY AFTN. WILL
MENTION A CHANCE OF THUNDER WITH MARGINAL INSTBY INDICATED AHD OF
THIS FRONT.
IN RETURN SOUTHERLY FLOW TEMPERATURES TO BE CLOSE TO NORMAL
THURSDAY...WITH HIGHS RANGING FROM THE LOWER 50S NW TO THE UPPER 50S
SE. ON THE WARM SIDE OF THIS SYSTEM...HIGHS ON FRIDAY TO RANGE FROM
THE MID 50S NW TO THE LOWER 60S SE.
MODEL DIFFERENCES EXISTS REGARDING THE DEVELOPMENT OF A SRN SECONDARY
SFC WAVE. ECMWF/CMC ARE MORE PROGRESSIVE WITH GFS DEVELOPING THIS
WAVE. WILL TREND FCST TOWARD MORE PROGRESSIVE SOLN AND ONLY LINGER A
CHANCE OF SHOWERS INTO FRIDAY EVENING WITH THE UPPER TROF LAGGING
ACRS THE REGION.
SFC HIGH PRESSURE TO BUILD ACRS THE REGION PROVIDING DRY WEATHER
CONDITIONS AND COOLER TEMPERATURES. SATURDAYS HIGH TEMPERATURES TO
RANGE FROM UPPER 40S NORTHWEST TO THE MID 50S SOUTHEAST.
THIS HIGH TO QUICKLY SLIDE OFF TO THE EAST WITH A RETURN FLOW
DEVELOPING. TEMPERATURES TO WARM UP ABOVE NORMAL...WITH HIGHS FROM
THE UPPER 50S NORTHEAST TO THE LOWER 60S SOUTHWEST.
A FEW WAA SHOWERS WILL BE POSSIBLE NEXT MONDAY ESPECIALLY ACRS THE
NORTHWEST. HAVE LIMITED MENTION TO SLIGHT CHANCE CATEGORY AT THIS
TIME. TEMPERATURES TO CONTINUE TO WARM UP WITH HIGHS ON MONDAY FROM
THE MID 60S NW TO AROUND 70 SE.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
A SHARPENING H5 TROF WILL SWING ACROSS THE GREAT LAKES AND OHIO
THIS MORNING. AT THE SAME TIME...A SFC CDFNT WILL PUSH ACROSS THE TAFS
USHERING ANOTHER SHOT OF CAA. LOW LEVEL FRONTAL CONVERGENCE AND
INCREASING INSTABILITY IN THE CAA WILL PRODUCE SHSN. CIGS AND
VSBYS WILL LIKELY DROP INTO AT LEAST MVFR WITHIN THE SHSN.
TIGHTENING PRESSURE GRADIENT TODAY WILL INCREASING WINDS WITH
GUSTS TO AS MUCH AS 30 KNOTS.
NW FLOW OFF THE LAKES WILL KEEP VFR CIGS AND POSSIBLY A FLURRY
ACROSS THE TAFS INTO THE EVENING HOURS. BUILDING HIGH PRESSURE
SHOULD BEGIN TO BREAK UP THE CIGS FROM SW TO NE AFT 06Z.
OUTLOOK...MVFR CEILINGS AND VISIBILITIES LIKELY LATE THURSDAY NIGHT
INTO FRIDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...JGL
SHORT TERM...FRANKS
LONG TERM...AR
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
933 AM PDT Tue Mar 25 2014
.Synopsis...
Wet and cooler weather will arrive today and continue through the
weekend. Significant mountain snow and gusty winds are likely with
possible thunderstorms in the Valley.
&&
.Discussion...
Initial rain band tracking southeast through the northern Sac
valley this morning and will reach the central and southern valley
around noon. This band will break apart somewhat and become more
showery as it transitions east during the afternoon. A few
thunderstorms will be possible this afternoon with the best
instability over the southern sac and nrn San Joaquin valley
between 3-7pm. Small hail will be the main threat with storms.
Current snow levels are around 6500 feet and will fall to 5500
feet by sunset. Short term forecast is on track and no morning
update will be needed.
.Previous Discussion...
Major pattern change begins for interior NorCal today as the
persistent ridge along the west coast gives way to a trough over
the eastern Pacific extending southward from a deep upper low over
the NE Pacific off the coast of BC. A series of weather systems
emanating from this low are forecast to affect the region for at
least the next week or so.
The first in the series of weather systems is presently nearing
the northern CA coast. Radar shows the frontal band just off the
NW coast of CA early this morning, and it will move eastward
across the region today. Precip is expected to begin in the
Redding area this morning, in the Sacramento region this afternoon
and spread east into the northern Sierra by late today or this
evening.
This first system will only bring modest precip totals for the
area. It may also bring a chance of thunderstorms across the
valley later today if the frontal band moves through quick enough
allowing for some clearing late in the day. The latest HRRR times
the back edge of the frontal band through the valley by mid-
afternoon, so this is something to watch this afternoon. Models
continue to show the best instability and surface convergence
across the southern half of the Sacramento Valley southward into
the northern SJ Valley. Snow levels will start initially high
with this system, but rapidly drop below 6000 ft by evening.
Another wave of precip and colder air arrives on Wednesday and
continues into Thursday. With westerly to southwesterly flow
aloft, favorable orographics are expected over the Sierra but may
limit precipitation along the downslope parts of the Sacramento
Valley. Through these two events, potentially up to an inch of
rain will be possible over parts of the Valley. Snow levels will
drop down to around 4000 ft with 4 to 8 inches possible above that
level. Over a foot of snow is expected above 5500 ft with 2 feet
along the northern Sierra crest. Strong winds will also be
possible over mountain ridges.
Convective parameters still look decent for thunderstorms on
Wednesday, with perhaps a bit more upper support when compared to
today. Convection may be a bit more widespread on Wednesday, but
this will once again depend on how much surface clearing is able
to develop during the period of peak heating (afternoon). Wind
shear profiles look very favorable for rotating updrafts on
Wednesday with long looping hodographs indicative of strongly
veering winds with height. An isolated tornado or two may be
possible depending on whether discrete cells are able to develop.
Showery weather continues Thursday, mainly over the mountains, as
cyclonic NWLY flow remains over NorCal. Deeper moisture with
another system begins to affect the region later Friday and Friday
night.
&&
.Extended Discussion (Saturday through Tuesday)
Extended models in good agreement in bringing next Pacific frontal
system on to the north coast by 12z Saturday. Precipitable water
proggs showing a sub tropical moisture feed of around an inch TPW
so this should be a moderately wet system. Snow levels will start
out fairly high at about 6000 feet but then drop on Sunday as the
colder air behind the cold front filters into the area. By this
time however...most of the precipitation will have ended. Breezy
to windy conditions will accompany this system as well with
moderately tight pressure gradients both surface and aloft
predicted. Showers on Sunday with a brief break Sunday night will
be followed but yet another frontal passage on Monday as models
keep upper level troughing over the eastern Pacific. At this
time...this system does not look as wet as the one moving through
over the weekend but it should be a colder system with snow levels
dropping to between 3000 and 4000 feet by Tuesday morning. Showery
and cool conditions expected to continue through the day Tuesday
with daytime highs expected to remain a few to several degrees
below normal.
&&
.Aviation...
Pacific frontal system pushing on to the north coast this morning
will bring lowering ceilings after 18z today north and west of
about kcic and across most areas of NORCAL by this evening.
Ceilings transitioning from VFR this morning to MVFR over the
valley and foothills this afternoon and evening with rain and a
slight chance of thunderstorms. Coastal mountains becoming IFR
after 18z with IFR conditions over the Sierra Cascade range after
00z for low ceilings and rain and snow. Snow level around 5000
feet. Low ceilings continuing through 12z.
&&
.STO Watches/Warnings/Advisories...
winter storm warning from 3 pm this afternoon to 11 am pdt
thursday above 5500 feet in the west slope northern sierra
nevada...western plumas county/lassen park.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1019 AM MDT TUE MAR 25 2014
.UPDATE...
&&
.SHORT TERM...WEB CAMS AND SATELLITE INDICATING LOW CLOUDS
CONTINUE TO DISSIPATE...STILL A BIT ALONG THE FOOTHILLS AND ACROSS
NORTHEAST LARIMER INTO NORTHERN WELD COUNTIES. DRIER AIRMASS ALONG
WITH DAYTIME HEATING WILL HELP DISSIPATE THE LOW CLOUDS. RIDGE
WILL BE OVER THE REGION TODAY BEFORE SHIFTING EAST TONIGHT WITH
MILD TEMPERATURES AND LIGHT WINDS. FORECAST SOUNDINGS INDICATE
HIGHS TO WARM INTO THE 50S...WITH LOWER 60S IN THE DENVER AREA.
OVERALL CURRENT FORECASTS LOOK ON TRACK. WILL MAKE MINOR
ADJUSTMENTS TO TEMPERATURE GRIDS BASED ON CURRENT AND EXPECTED
CONDITIONS.
.AVIATION...CURRENT TAF TRENDS LOOK ON TRACK WITH VFR CONDITIONS
PREVAILING. WITH WEAK DENVER CYCLONE CURRENTLY OVER THE DENVER
AREA...LIGHT SOUTHERLY WINDS EXPECTED TO TREND TOWARD THE
SOUTHEAST BY 18Z. LATEST RAP SHOWS THE WINDS BECOMING EAST
NORTHEAST BETWEEN 18Z AND 20Z. CURRENT TAFS SHOW THIS
TREND...SEEMS REASONABLE AT THIS TIME. DRAINAGE TO DEVELOP DURING
THE EVENING...WITH SOUTHWEST WINDS PREVAILING WEDNESDAY. SOME
GUSTS TO 20 KTS POSSIBLE AFTER 18Z WEDNESDAY.
&&
.PREV DISCUSSION... /ISSUED 734 AM MDT TUE MAR 25 2014/
UPDATE...STRATUS DECK HAS LIFTED TO THE NORTHERN BORDER AREA AS
LOW LEVEL FLOW HAS TURNED MORE SOUTHERLY. STILL A FEW CLOUDS STUCK
ALONG THE FOOTHILLS...BUT THESE TOO WILL BE ERODING IN THE NEXT
COUPLE HOURS. ANY PATCHY FOG THREAT WILL BE ALL BUT GONE IN THE
NEXT HOUR AS WELL AS DAYTIME HEATING BEGINS.
AVIATION...LOW CLOUDS HAVE CLEARED THE FRONT RANGE AIRPORTS...BUT
A FEW PATCHES STILL LINGERED NEAR KBJC. VFR CONDITIONS AND LIGHT
WINDS WILL PREVAIL.
PREV DISCUSSION... /ISSUED 345 AM MDT TUE MAR 25 2014/
SHORT TERM...TODAY AND TONIGHT...AN UPPER LEVEL RIDGE WILL MOVE
ACROSS THE STATE TODAY. LOW CLOUDS WILL PREVAIL THIS MORNING...AND
MAY SEE PATCHY FOG OVER SOME OF THE HIGHER AREAS...MAINLY IN THE
NORTHERN FOOTHILLS AND NEAR THE WYOMING BORDER. ONCE THE LOW CLOUDS
BURN OFF...IT WILL BE A MILD DAY WITH HIGHS IN THE MID TO UPPER 50S
ACROSS NORTHEAST COLORADO. WINDS WILL BE LIGHT AND SKIES WILL BE
MOSTLY SUNNY AS A SURFACE HIGHS SLIDES SOUTH JUST TO THE EAST OF
COLORADO.
THE RIDGE WILL SHIFT EAST OF COLORADO TONIGHT LEAVING A SOUTHWEST
FLOW BEHIND IT. AIRMASS WILL REMAIN DRY. A LEE SIDE TROUGH WILL FORM
OVER EASTERN COLORADO LATE TONIGHT. THIS MAY CAUSE WINDS IN THE
MOUNTAINS AND FOOTHILLS TO INCREASE TOWARDS WEDNESDAY MORNING. THIS
SURFACE TROUGH WILL MAKE FOR A BREEZY WEDNESDAY.
LONG TERM...A SERIES OF SHORTWAVE TROUGHS AND RIDGES TRAVELING IN
A GENTLY UNDULATING ZONAL FLOW ACROSS THE CONTINENTAL U.S. WILL
PROVIDE DAILY VARIATIONS IN TEMPERATURE...SKY COVER AND WINDS
THROUGH NEXT WEEKEND. AN UPPER RIDGE PASSING OVERHEAD TODAY WILL
BE REPLACED BY A SHORTWAVE TROUGH LATE ON WEDNESDAY. MODELS AND A
MAJORITY OF THE GFS ENSEMBLE MEMBERS SHOW THE LEADING EDGE OF THIS
NEXT SHORTWAVE TROUGH MERGING WITH A CLOSED LOW MOVING UP FROM THE
NORTHERN BAJA PENINSULA. THIS LOW OPENS UP AS IT RACES ACROSS
NORTHERN NEW MEXICO AHEAD OF THE MAIN TROUGH OVER THE WEST COAST
EARLY ON WEDNESDAY. WITH THE BULK OF ITS ENERGY AND MOISTURE
PASSING SOUTH OF COLORADO...SEE LITTLE MORE THAN AN INCREASE IN
MID-LEVEL CLOUDS AND WARM AND GUSTY SOUTHWEST WINDS FOR MUCH OF
THE CWFA ON WEDNESDAY. ITS POSSIBLE THAT AREAS ALONG THE FRONT
RANGE AND OVER THE PALMER DIVIDE COULD SEE TEMPERATURES AND RHS
APPROACHING CRITICAL FIRE WEATHER THRESHOLDS WEDNESDAY AFTERNOON.
FOR NOW NO HIGHLIGHTS. MODELS SHOW MOISTURE CONTINUING TO STREAM
INTO THE AREA ON STRENGTHENING SOUTHWEST FLOW WEDNESDAY EVENING
AHEAD OF THE MAIN UPPER TROUGH OVER THE GREAT BASIN. MODELS SHOW
AREAS OF LIGHT QPF DEVELOPING IN THE HIGH COUNTRY DURING THE
EVENING. FCST LAPSE RATES ARE SUCH THAT MOST OF THIS PRECIP WILL
BE SHOWERY IN NATURE WITH THE SNOW LEVEL STARTING OUT AROUND 10
THSND FEET MSL AND LOWERING TO NEAR 6500 FT MSL BY MORNING WITH
THE THERMAL TROUGH PASSING BY. EAST OF THE MTNS...SHOULD SEE SKIES
FILL WITH CLOUDS DURING THE EVENING HOURS AS PER MODEL CROSS
SECTIONS...AND POSSIBLY LOWERING TO JUST OFF THE DECK DURING THE
PRE-DAWN HOURS WITH SCATTERED RAIN/SNOW SHOWERS. MODELS INDICATE
MOST OF THE PRECIP ON THE PLAINS OCCURRING ACROSS NORTHERN AND
EASTERN SECTIONS WITH THE PASSAGE OF A COLD FRONT AFTER MIDNIGHT.
PRECIP AMOUNTS ON THE LOW SIDE BOTH MTNS AND PLAINS...ALTHOUGH
HIGHER WEST FACING SLOPES COULD PICK UP A COUPLE INCHES OF SNOW BY
THURSDAY MORNING. THE NORTHEAST CORNER OF THE STATE MAY ALSO SEE A
QUICK INCH OR SO OF SNOW OVERNIGHT.
THURSDAY THROUGH FRIDAY MORNING...MODELS PORTRAY A PERIOD OF COOLER
AND UNSETTLED WEATHER AS A PAIR OF WEAK MID-LEVEL PERTURBATIONS
SWING ACROSS THE REGION. DIFFICULT TO PIN DOWN ANY SPECIFIC
PERIOD OF PRECIP BASED ON CURRENT MODEL GUIDANCE. ALTHOUGH ODDS
FAVOR PRECIP ON WINDWARD MTN SLOPES WITH COLD AIR ADVECTION WITH
NORTHWEST FLOW. PLAINS ALSO HAVE A SLIGHT CHANCE OF PRECIP DURING
THIS PERIOD...MOST IF NOT ALL OF IT AS RAIN SHOWERS...AND MOST OF
THAT PROBABLY EAST OF THE I-25 URBAN CORRIDOR DUE TO THE DRYING
EFFECTS OF DOWNSLOPE FLOW OFF THE FRONT RANGE. TEMPERATURES BOTH
DAYS NEAR TO SLIGHTLY BELOW AVERAGE. A DRIER AND WARMER WEST-
NORTHWEST FLOW RETURNS TO THE FCST AREA LATE ON FRIDAY.
LOOKING AHEAD TO THE WEEKEND...SATURDAY LOOKS EVEN WARMER AND DRIER
AS MEDIUM RANGE MODELS SHOW AN UPPER RIDGE BUILDING ACROSS THE
STATE. PORTIONS OF NORTHEAST COLORADO COULD SEE 70S FOR HIGHS ON
SATURDAY. BY SUNDAY...WEATHER PICTURE NOT AS CLEAR CUT. MODELS FOR
THE MOST PART SHOW A WEAK SHORTWAVE IN ZONAL FLOW ALOFT MIGRATING
OVER THE AREA DURING THE DAY. MODELS DIFFER AS TO ITS STRENGTH AND
ITS POTENTIAL TO PRODUCE CLOUDS/PRECIP. GFS AND ECMWF HINT AT A FEW
SHOWERS DURING THE AFTERNOON...AND MAINLY OVER THE HIGHER
ELEVATIONS. OTHERWISE SUNDAY LOOKS DRY WITH DAYTIME TEMPERATURES
NEAR AVERAGE IN THE HIGH COUNTRY AND SEVERAL DEGS ABOVE AVERAGE ON
THE PLAINS...ESPLY IN AREAS EXPOSED TO DOWNSLOPE FLOW OFF THE
FOOTHILLS. MONDAY CONTINUES DRY BUT SLIGHTLY COOLER WITH AN UPPER
RIDGE BUILDING TO OUR WEST.
AVIATION...LOW CLOUDS ARE EXPECTED TO PREVAIL THROUGH MID TO
LATE MORNING. CEILINGS SHOULD RANGE FROM 1500 TO 3000 FEET. THERE
IS A CHANCE FOR FOG WITH VISIBILITY BELOW A QUARTER MILE BETWEEN
11 AND 15Z...MAINLY AT KDEN. A WEAK DENVER CYCLONE HAS FORMED AND
IS KNOWN TO BRING IN FOG WITH ITS NORTHWESTERLY WINDS AROUND 12Z
AT KDEN. ONCE THE LOW CLOUDS BURN OFF...MOSTLY CLEAR SKIES WILL
PREVAIL THROUGH TONIGHT. LIGHT WINDS THIS MORNING WILL TURN
SOUTHEAST TODAY AND BECOME SOUTHWEST AFTER 00Z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....COOPER
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS POCATELLO ID
222 PM MDT TUE MAR 25 2014
.SHORT TERM...YESTERDAY THE GFS CONSOLIDATED THE SPLITTING TROUGH AS IT MOVED
THROUGH SOUTHEAST IDAHO ON WEDNESDAY WHILE THE OTHER MODELS
MAINTAINED THE STRETCHING/SPLITTING SCENARIO. TODAY THE GFS IS BACK
TO STRETCHING THE TROUGH WITH MORE ENERGY CROSSING SOUTH OF THE
STATE. NICE TO HAVE SOME CONSISTENCY. HANDLING OF COLD AIR ADVECTION
HAS ALSO BEEN DIFFICULT. THE 12Z NAM12 RUN LOWERED SNOW LEVELS FOR
WEDNESDAY MORNING TO A LITTLE BELOW 5000 FEET ELEVATION. AT THE SAME
TIME SURFACE TEMPERATURES SHOULD BE ABOVE FREEZING...THEREFORE DID A
LITTLE COMPROMISE ON SNOW LEVELS. COLD FRONT SHOULD COME THROUGH 6-9
AM MDT WEDNESDAY. PLANNING ON ENOUGH RAIN WITH THE FRONT TO WET THE
DIRT BEFORE WINDS COME UP. CONFIDENCE IN THUNDERSTORMS IS NOT HIGH
BUT LAPSE RATES ARE PRETTY STEEP...MAY EVEN GET SOME ICE OR SNOW
PELLETS WITH CONVECTIVE SHOWERS. ALSO REJECTED THE NAM MOS WINDS OF
30 KTS AT POCATELLO...BLAMING IT PARTLY ON THE HANDLING OF COLD
AIR...PREFERENCE GFS MOS KEEPING WINDS 15 TO 25 MPH RANGE IN THE
LOWER SNAKE PLAIN AND EAST MAGIC VALLEY. FOR THURSDAY...SURFACE
PRESSURE GRADIENT...COLD AIR ADVECTION AND UPPER LEVEL WINDS ALL
SUPPORT STRONGER WINDS OF 25 TO 35 MPH WITH GUSTS INTO THE 40S. FOR
SNOW AMOUNTS BETWEEN MIDNIGHT TONIGHT THROUGH MIDNIGHT WEDNESDAY
NIGHT...FAVOR 1 TO 3 INCHES ABOVE 5500 FEET...MAYBE LOCAL 4 INCHES
ON WEST FACING SLOPES NEAR SUN VALLEY AND MACKS INN. MIDNIGHT
WEDNESDAY NIGHT TO FRIDAY MORNING...DEEPER MOISTURE SURGES ACROSS
THIS AREA WITH ACCUMULATION UP TO 6 INCHES HIGHER ELEVATIONS OF THE
CENTRAL MOUNTAINS AND PERHAPS THE NORTHERN WASATCH RANGE...AND
MOUNTAIN TOP WINDS APPROACH 30 TO 40 MPH. THERE IS A GOOD CHANCE A
WINTER WEATHER ADVISORY WILL BE NEEDED FOR THE MOUNTAINS AND AT
LEAST A WIND ADVISORY IN THE SNAKE PLAIN. CONTRARY TO YESTERDAYS GFS
MODEL...THIS FRIDAY SHOULD HAVE A BREAK IN PRECIPITATION WHILE A
SHORT WAVE RIDGE MOVES THROUGH BEFORE THE NEXT STORM SYSTEM.
RS
.LONG TERM...FRI NIGHT THROUGH NEXT TUE NIGHT. HUGE DIFFERENCES HAVE
DEVELOPED BETWEEN THE GFS AND ECMWF. THE 25/12Z GFS APPEARS TO
HAVE...PERHAPS...DEVELOPED A CONVECTIVE FEEDBACK THAT HAS SENT THE
QPF PRODUCTION TO GOING CRAZY. AS MUCH AS 1.22 INCHES PRODUCED IN 12
HOURS IN THE CENTRAL IDAHO MOUNTAINS WHILE THE ECMWF HAS LESS THAN
1/2 OF THAT AMOUNT. HAVENT MADE MUCH CHANGE DURING THE TIME PERIOD.
MAINLY CORRECTED FOR BORDER ISSUES AND TRIED TO SPLIT THE DIFFERENCE
FOR THE FIRST FOUR PERIODS WHEN IT COMES TO POP AND SKY. TIMING HAS
ALSO SLIPPED OUT OF AGREEMENT FOR MOST TIME PERIODS. VERY LOW
CONFIDENCE FORECAST ALL AROUND. MESSICK
&&
.AVIATION...LARGE DIFFERENCES SURFACED BETWEEN NAM AND GFS. THE GFS
HAS STAYED DRY FOR TONIGHT...WHILE THE NAM HAS BECOME MUCH WETTER.
THIS HAS LED TO THE NAM PREDICTING MARGINAL VFR CIGS AND RAIN FOR
WED EARLY MORNING. DID NOT HAVE THE HRRR GUIDANCE FOR WINDS AND THE
NAM HAS SOME STRONGLY CHANGING DIRECTIONS AND SPEEDS EVERY THREE
HOURS. SOMEWHAT LOW CONFIDENCE IN THIS FORECAST...BUT HAVE LEFT THE
CIGS ABOVE THE MARGINAL VFR THRESHOLD. HRRR HAS JUST SINCE RESTARTED
AND MAY BE OF USE IN SUBSEQUENT FORECASTS WHEN IT HAS FULLY COME IN.
THE MAIN FORECAST PROBLEM IS JUST BEYOND THE 26/18Z END TIME OF THE
CURRENT TAFS WHEN NAM GOES FOR 30KT SUSTAINED WIND V. 16KT SUSTAINED
WIND OF THE GFS. CURRENTLY BELIEVE THAT THE GFS HAS BEEN MORE
CONSISTENT AND RELIABLE...THUS BELIEVE THE DRIER AND CALMER SCENARIO
FOR NOW. MESSICK
&&
.PIH WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
221 PM CDT TUE MAR 25 2014
.DISCUSSION...
1035 AM CDT
THERE WERE MAINLY JUST SOME TWEAKS TO HOURLY CONDITIONS FOR THE
FORECAST THE REST OF TODAY...OTHERWISE ALL IS IN GOOD SHAPE.
THE 12Z RAOBS INDICATED 850-500MB READINGS THAT WERE ABOUT AS
COLD AS THEY CAN REACH IN THIS REGION DURING LATE MARCH. THE
850-925MB COLD AIR ADVECTION IS AT IS MAX OVER THE CWA LATE THIS
MORNING...WITH -18C KNOCKING ON THE DOOR PER THE RAP ANALYSIS.
THIS AIDED BY A SHEARED SHORT WAVE LOOK TO KEEP SCATTERED LIGHT
SNOW SHOWERS/FLURRIES GOING INTO EARLY AFTERNOON. REMARKABLY DRY
LOW-LEVEL AIR LOOKS TO SPREAD IN BY MID-AFTERNOON WITH UPSTREAM
DEW POINT OBSERVATIONS IN THE LOWER TO MID SINGLE DIGITS. THE
SURFACE PRESSURE GRADIENT REMAINS TIGHT AND SOUNDINGS SUPPORT
GUSTS THROUGH THE AFTERNOON...WITH A RELAXING GRADIENT MOVING
QUICKLY IN THIS EVENING AS HIGH PRESSURE BUILDS IN FROM THE PLAINS.
MTF
//PREV DISCUSSION...
NARROW BUT INTENSE BAND OF SNOW ALONG COLD FRONT WILL CONTINUE TO
MOVE ACROSS THE SOUTHEAST HALF OF THE CWA OVER THE NEXT FEW HOURS.
GENERALLY QUICK DROP TO 1/4SM VIS WITH 0.5-1.0 INCH ACCUMULATIONS IN
20 MINUTES WITHIN THE HEAVIER SNOW SHOWERS. EXTRAPOLATION OF RADAR
LOOP INDICATES BAND SHOULD EXIT ALL BUT PERHAPS THE EXTREME
SOUTHEAST PART OF THE FORECAST AREA BY SUNRISE...WITH A FEW LIGHTER
SNOW SHOWERS ALSO ACROSS FAR NORTHEAST IL BENEATH PATH OF MID-LEVEL
VORT DURING THAT TIME. RELATIVELY DRY ARCTIC AIR SPREADING IN FROM
THE NORTHWEST WILL ALLOW SOME SCATTERING OF CLOUD COVER AND AN END
TO ACCUMULATING SNOW SHOWERS BY SUNRISE...THOUGH ONE MORE SHORT WAVE
DROPPING SOUTHEAST ACROSS MINNESOTA AT 08Z MAY BE ENOUGH TO PRODUCE
SOME ENHANCED STRATOCU AND A FEW FLURRIES ACROSS THE REGION DURING
THE MID/LATE MORNING HOURS. IN THE WAKE OF THE PASSAGE OF THIS
MID-LEVEL VORT AXIS AROUND MIDDAY...RISING HEIGHTS AND SUBSIDENCE
SHOULD RESULT IN AN END TO FLURRIES AND THINNING/EROSION OF THE
STRATOCU DECK ALLOWING PARTLY CLOUDY/MOSTLY SUNNY SKIES THIS
AFTERNOON. BLUSTERY NORTHWEST WINDS WILL KEEP TEMPS WELL BELOW
NORMAL ONCE AGAIN...WITH UPPER 20S/LOW 30S EXPECTED FOR AFTERNOON
HIGHS PER BIAS CORRECTED MOS BLEND. BROAD UPPER RIDGE BUILDS ACROSS
THE REGION TONIGHT IN THE WAKE OF OUR DEPARTING EASTERN CONUS UPPER
TROUGH WITH SURFACE HIGH PRESSURE RIDGE BUILDING INTO THE REGION
OVERNIGHT. THIS MORNINGS LIGHT SNOWFALL WILL BE GONE BY
TONIGHT...THOUGH LIGHT WINDS AND CLEAR SKIES WILL ALLOW FOR COOLING
INTO THE TEENS IN MOST AREAS BY WEDNESDAY MORNING.
SURFACE HIGH PRESSURE MOVES QUICKLY EAST OF THE FORECAST AREA
WEDNESDAY AS SURFACE PRESSURE FALLS DEVELOP ACROSS THE PLAINS AND
MISSISSIPPI VALLEY IN RESPONSE TO SURFACE LOW DEVELOPING OVER THE
DAKOTAS IN ADVANCE OF AN UPPER TROUGH OVER THE WESTERN CONUS AND
UPPER JET MAX SPREADING ACROSS THE CENTRAL AND SOUTHERN ROCKIES.
THIS RESULTS IN FAIRLY QUICK WARM ADVECTION AND MOISTURE TRANSPORT
INTO THE REGION ESPECIALLY ABOVE THE BOUNDARY LAYER AS 40-50 KT
SOUTH-SOUTHWESTERLY LOW LEVEL JET DEVELOPS BY LATE AFTERNOON.
INCREASING MID-LEVEL CLOUD COVER WILL LIKELY OFFSET SOME OF THE
WARMING AS WILL A SLIGHT SOUTHEAST COMPONENT TO THE BOUNDARY LAYER
WIND. EVEN SO...FAVOR WARMER MAV GUIDANCE OF WEDNESDAY AFTERNOON MAX
TEMPS IN THE UPPER 30S/LOWER 40S. EXCEPTION WILL BE ALONG THE
IMMEDIATE NORTH SHORE AREA...WHERE THAT SLIGHT SOUTHEAST WIND
COMPONENT MAY HOLD TEMPS IN THE MID 30S RIGHT ALONG THE LAKE. DEEPER
MOISTURE CONTINUES TO SPREAD INTO THE REGION WEDNESDAY NIGHT...AS
SURFACE LOW MOVES INTO THE UPPER MISSISSIPPI VALLEY AND A SHORT WAVE
TROUGH PROPAGATES FROM THE SOUTH CENTRAL PLAINS INTO THE WESTERN
GREAT LAKES. FORECAST SOUNDINGS DEPICT DEEP SATURATION OCCURRING
MAINLY AFTER MIDNIGHT...WITH SUFFICIENT FORCING APPROACHING SHORT
WAVE AND ISENTROPIC ASCENT/JET DIVERGENCE TO GO WITH LIKELY POPS.
THERMAL PROFILES BECOME NEARLY ISOTHERMAL NEAR 0C IN THE LOWER
LEVELS INITIALLY BEFORE WARM ADVECTION OVERWHELMS THE
COLUMN...SUGGESTING THE POTENTIAL FOR S BRIEF MIX OF RAIN/SNOW WITH
THE ONSET OF PRECIP...BUT QUICKLY TURNING TO RAIN AS 50-60 KT LOW
LEVEL JET CONTINUES TO PUMP IN WARM/MOIST AIR. TIGHT SFC PRESSURE
GRADIENT WILL MAINTAIN BREEZY SOUTH WINDS OVERNIGHT AS WELL...WHICH
WILL LIKELY KEEP TEMPS ABOVE FREEZING OVERNIGHT AND PROBABLY RISING
BEFORE SUNRISE. INITIAL SHORT WAVE LIFTS ACROSS THE AREA THURSDAY
MORNING...WITH AN AREA OF MODESTLY STEEP MID-LEVEL LAPSE RATES NOTED
ACROSS CENTRAL IL AND SOUTHERN CWA. HAVE INDICATED ISOLATED THUNDER
FAR SOUTH DURING THE MORNING PERIOD WITH THESE BETTER ELEVATED LAPSE
RATES BEFORE SOME MID-LEVEL DRYING OCCURS BEHIND THE INITIAL SHORT
WAVE. SHOWER CHANCES REMAIN RELATIVELY HIGH THROUGH THE DAY THURSDAY
IN MOIST WARM SECTOR...WITH GFS PRECIPITABLE WATER NEAR 0.9
INCHES...AND APPROACH OF SECOND SHORT WAVE/MAIN TROUGH AXIS LATER IN
THE DAY ALONG WITH APPROACH OF SURFACE COLD FRONT THURSDAY EVENING.
ECMWF REMAINS A LITTLE SLOWER WITH THE PASSAGE OF THE LOW/COLD FRONT
THURSDAY NIGHT...SO HAVE MAINTAINED POPS INTO THE NIGHT WITH A LOW
CHANCE LINGERING IN THE FAR EAST INTO EARLY FRIDAY. MILD/MOIST AIR
MASS SHOULD PUSH TEMPS UP AROUND 50 THURSDAY DESPITE CLOUDS/PRECIP.
COOLER AIR WORKS IN FRIDAY WITH WEAK HIGH PRESSURE RIDGE BEHIND
DEPARTING SYSTEM...WITH WINDS LIKELY TURNING NORTHEAST OFF THE LAKE
FRIDAY AFTERNOON KEEPING LAKESIDE LOCATIONS CHILLY AROUND 40 DEG.
GUIDANCE IN GOOD AGREEMENT IN BRINGING ANOTHER PROGRESSIVE AMPLIFIED
SHORT WAVE ACROSS THE AREA FRIDAY NIGHT/SATURDAY...WITH AN AREA OF
SURFACE LOW PRESSURE PASSING SOUTH OF THE CWA. MOST OF THE PRECIP
REMAINS SOUTH/SOUTHEAST OF THE FORECAST AREA WITH THIS FEATURE...
THOUGH HAVE INCLUDED LOW CHANCE POPS MAINLY FRIDAY NIGHT. PRECIP
TYPE COULD BE A QUESTION ESPECIALLY SOUTH WHERE IT COULD BE A
RAIN/SNOW MIX PER THICKNESS PROGS AND THERMAL PROFILES. NORTHEAST
WINDS AROUND THE NORTHERN PERIPHERY OF THE PASSING LOW WILL CONTINUE
TO HOLD TEMPS BELOW NORMAL...ESPECIALLY NEAR LAKE MICHIGAN. MODELS
CONTINUE TO DEVELOP ANOTHER DEEP LOW ACROSS THE NORTHERN PLAINS
SUNDAY/MONDAY...WITH STRONG SOUTH FLOW DEVELOPING AND OFFERING THE
PROSPECT OF WARMER WEATHER BY THE END OF THE FORECAST PERIOD.
BLENDED GUIDANCE INDICATES 55-60+ DEGREES SUNDAY AND MONDAY...THOUGH
WITH BREEZY CONDITIONS AND AN INCREASING POTENTIAL FOR RAIN MONDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* STRONG/GUSTY NORTHWEST WINDS THROUGH LATE AFTERNOON.
* POSSIBLE GUSTY SOUTH/SOUTHEAST WINDS WEDNESDAY AFTERNOON. CMS
//DISCUSSION...UPDATED 18Z...
A WEAK UPPER TROUGH IS PASSING SOUTHEAST OF THE AREA EARLY THIS
AFTERNOON. SCATTERED FLURRIES AND A FEW SNOW SHOWERS WILL END AND
BKN 4KFT CIGS WILL GRADUALLY SCATTER OUT THROUGH THE AFTERNOON
WITH SKC EXPECTED TONIGHT.
WINDS WILL REMAIN STRONG/GUSTY FROM THE NORTHWEST WITH GUSTS INTO
THE MID 20KT RANGE. SPEEDS/GUSTS WILL QUICKLY DIMINISH WITH SUNSET
AND THEN BECOME LIGHT AND VARIABLE OVERNIGHT INTO WEDNESDAY
MORNING AS A RIDGE OF HIGH PRESSURE PASSES OVER THE AREA. WINDS
WILL TURN BACK SOUTHERLY WEDNESDAY MORNING AND INCREASE IN SPEEDS
DURING THE AFTERNOON...POSSIBLY BECOMING MORE SOUTH/SOUTHEAST
LATER WEDNESDAY AFTERNOON OVER THE CHICAGO AREA TERMINALS. CMS
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH FOR WIND SPEEDS/GUSTS/DIRECTIONS THROUGH THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...CHANCE OF RA AND MVFR. MAY START AS RA/SN MIX.
THURSDAY...PERIODS OF SHRA AND SUB VFR LIKELY. GUSTY SOUTH WINDS.
FRIDAY...VFR PROBABLE. WIND SHIFT TO NORTHEAST LATE DAY. SLIGHT
CHANCE -SN FRIDAY NIGHT.
SATURDAY...VFR LIKELY. NORTHEAST TO EAST WINDS.
SUNDAY...VFR. GUSTY SOUTH-SOUTHWEST WINDS. SLIGHT CHANCE SHRA SUN.
NIGHT.
MONDAY...CHANCE SHRA AND SUB VFR. GUSTY SOUTHWEST WINDS.
RC
&&
.MARINE...
219 PM CDT
AN ACTIVE EARLY SPRING WEATHER PATTERN WILL BE SEEN OVER THE GREAT
LAKES THROUGH THIS NEXT WEEK. FIRST IS THE ONGOING WIND EVENT. THE
GUSTY NORTHWEST WIND WILL EASE THIS EVE HOWEVER WAVES WILL BE SLOW
TO SUBSIDE ALONG THE ILLINOIS AND ESPECIALLY INDIANA NEARSHORE.
HIGH PRESSURE WILL BRIEFLY PREVAIL EARLY WEDNESDAY BEFORE A
STRENGTHENING SOUTHERLY WIND ENSUES. THIS WILL BE IN ADVANCE OF A
MARKEDLY DEEP LOW PRESSURE ACROSS THE UPPER TO CENTRAL
PLAINS...WHICH LOOKS TO MOVE OVER OR NEAR LAKE MICHIGAN ON
THURSDAY NIGHT. BECAUSE OF THE MAGNITUDE OF THE LOW...THE
SUSTAINED WINDS LOOK TO BE 20-30 KT OVER THE LAKE BUT DUE TO THE
STRENGTH OF THE INVERSION...THE GUST-TO-SUSTAINED RATIO LOOKS TO
BE LOW. THIS MAY END UP NEEDING A GALE HEADLINE FOR WEDNESDAY
NIGHT INTO THURSDAY...BUT CONFIDENCE ON THAT WAS TOO LOW AT THIS
TIME. BEHIND THIS SYSTEM ON FRIDAY THERE WILL BE A WINDOW FOR
GUSTY NORTHWEST WINDS...HOWEVER AT THIS TIME THIS PERIOD IS
FAVORED TO REMAIN BELOW GALE FORCE. ANOTHER SYSTEM IS ALREADY
INDICATED TO PASS OVER THE GREAT LAKES REGION EARLY NEXT WEEK AS
THE PROGRESSIVE PATTERN PERSISTS.
HAVE GONE AHEAD AND INCLUDED WAVES FOR ALL OPEN WATER ZONES IN THE
GLF AS ICE CONTINUES TO DIMINISH PER VISIBLE SATELLITE TRENDS.
CERTAINLY STILL SOME LOCKED ICE OUT THERE...ESPECIALLY IN THE
NORTHWEST-MOST ZONES. GIVEN THE UPCOMING TURBULENT PATTERN
CONTINUING...AM NOT EXPECTING THE ICE TO HAVE MUCH CHANCE TO GROW.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 PM TUESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1226 PM CDT TUE MAR 25 2014
.DISCUSSION...
1035 AM CDT
THERE WERE MAINLY JUST SOME TWEAKS TO HOURLY CONDITIONS FOR THE
FORECAST THE REST OF TODAY...OTHERWISE ALL IS IN GOOD SHAPE.
THE 12Z RAOBS INDICATED 850-500MB READINGS THAT WERE ABOUT AS
COLD AS THEY CAN REACH IN THIS REGION DURING LATE MARCH. THE
850-925MB COLD AIR ADVECTION IS AT IS MAX OVER THE CWA LATE THIS
MORNING...WITH -18C KNOCKING ON THE DOOR PER THE RAP ANALYSIS.
THIS AIDED BY A SHEARED SHORT WAVE LOOK TO KEEP SCATTERED LIGHT
SNOW SHOWERS/FLURRIES GOING INTO EARLY AFTERNOON. REMARKABLY DRY
LOW-LEVEL AIR LOOKS TO SPREAD IN BY MID-AFTERNOON WITH UPSTREAM
DEW POINT OBSERVATIONS IN THE LOWER TO MID SINGLE DIGITS. THE
SURFACE PRESSURE GRADIENT REMAINS TIGHT AND SOUNDINGS SUPPORT
GUSTS THROUGH THE AFTERNOON...WITH A RELAXING GRADIENT MOVING
QUICKLY IN THIS EVENING AS HIGH PRESSURE BUILDS IN FROM THE PLAINS.
MTF
//PREV DISCUSSION...
NARROW BUT INTENSE BAND OF SNOW ALONG COLD FRONT WILL CONTINUE TO
MOVE ACROSS THE SOUTHEAST HALF OF THE CWA OVER THE NEXT FEW HOURS.
GENERALLY QUICK DROP TO 1/4SM VIS WITH 0.5-1.0 INCH ACCUMULATIONS IN
20 MINUTES WITHIN THE HEAVIER SNOW SHOWERS. EXTRAPOLATION OF RADAR
LOOP INDICATES BAND SHOULD EXIT ALL BUT PERHAPS THE EXTREME
SOUTHEAST PART OF THE FORECAST AREA BY SUNRISE...WITH A FEW LIGHTER
SNOW SHOWERS ALSO ACROSS FAR NORTHEAST IL BENEATH PATH OF MID-LEVEL
VORT DURING THAT TIME. RELATIVELY DRY ARCTIC AIR SPREADING IN FROM
THE NORTHWEST WILL ALLOW SOME SCATTERING OF CLOUD COVER AND AN END
TO ACCUMULATING SNOW SHOWERS BY SUNRISE...THOUGH ONE MORE SHORT WAVE
DROPPING SOUTHEAST ACROSS MINNESOTA AT 08Z MAY BE ENOUGH TO PRODUCE
SOME ENHANCED STRATOCU AND A FEW FLURRIES ACROSS THE REGION DURING
THE MID/LATE MORNING HOURS. IN THE WAKE OF THE PASSAGE OF THIS
MID-LEVEL VORT AXIS AROUND MIDDAY...RISING HEIGHTS AND SUBSIDENCE
SHOULD RESULT IN AN END TO FLURRIES AND THINNING/EROSION OF THE
STRATOCU DECK ALLOWING PARTLY CLOUDY/MOSTLY SUNNY SKIES THIS
AFTERNOON. BLUSTERY NORTHWEST WINDS WILL KEEP TEMPS WELL BELOW
NORMAL ONCE AGAIN...WITH UPPER 20S/LOW 30S EXPECTED FOR AFTERNOON
HIGHS PER BIAS CORRECTED MOS BLEND. BROAD UPPER RIDGE BUILDS ACROSS
THE REGION TONIGHT IN THE WAKE OF OUR DEPARTING EASTERN CONUS UPPER
TROUGH WITH SURFACE HIGH PRESSURE RIDGE BUILDING INTO THE REGION
OVERNIGHT. THIS MORNINGS LIGHT SNOWFALL WILL BE GONE BY
TONIGHT...THOUGH LIGHT WINDS AND CLEAR SKIES WILL ALLOW FOR COOLING
INTO THE TEENS IN MOST AREAS BY WEDNESDAY MORNING.
SURFACE HIGH PRESSURE MOVES QUICKLY EAST OF THE FORECAST AREA
WEDNESDAY AS SURFACE PRESSURE FALLS DEVELOP ACROSS THE PLAINS AND
MISSISSIPPI VALLEY IN RESPONSE TO SURFACE LOW DEVELOPING OVER THE
DAKOTAS IN ADVANCE OF AN UPPER TROUGH OVER THE WESTERN CONUS AND
UPPER JET MAX SPREADING ACROSS THE CENTRAL AND SOUTHERN ROCKIES.
THIS RESULTS IN FAIRLY QUICK WARM ADVECTION AND MOISTURE TRANSPORT
INTO THE REGION ESPECIALLY ABOVE THE BOUNDARY LAYER AS 40-50 KT
SOUTH-SOUTHWESTERLY LOW LEVEL JET DEVELOPS BY LATE AFTERNOON.
INCREASING MID-LEVEL CLOUD COVER WILL LIKELY OFFSET SOME OF THE
WARMING AS WILL A SLIGHT SOUTHEAST COMPONENT TO THE BOUNDARY LAYER
WIND. EVEN SO...FAVOR WARMER MAV GUIDANCE OF WEDNESDAY AFTERNOON MAX
TEMPS IN THE UPPER 30S/LOWER 40S. EXCEPTION WILL BE ALONG THE
IMMEDIATE NORTH SHORE AREA...WHERE THAT SLIGHT SOUTHEAST WIND
COMPONENT MAY HOLD TEMPS IN THE MID 30S RIGHT ALONG THE LAKE. DEEPER
MOISTURE CONTINUES TO SPREAD INTO THE REGION WEDNESDAY NIGHT...AS
SURFACE LOW MOVES INTO THE UPPER MISSISSIPPI VALLEY AND A SHORT WAVE
TROUGH PROPAGATES FROM THE SOUTH CENTRAL PLAINS INTO THE WESTERN
GREAT LAKES. FORECAST SOUNDINGS DEPICT DEEP SATURATION OCCURRING
MAINLY AFTER MIDNIGHT...WITH SUFFICIENT FORCING APPROACHING SHORT
WAVE AND ISENTROPIC ASCENT/JET DIVERGENCE TO GO WITH LIKELY POPS.
THERMAL PROFILES BECOME NEARLY ISOTHERMAL NEAR 0C IN THE LOWER
LEVELS INITIALLY BEFORE WARM ADVECTION OVERWHELMS THE
COLUMN...SUGGESTING THE POTENTIAL FOR S BRIEF MIX OF RAIN/SNOW WITH
THE ONSET OF PRECIP...BUT QUICKLY TURNING TO RAIN AS 50-60 KT LOW
LEVEL JET CONTINUES TO PUMP IN WARM/MOIST AIR. TIGHT SFC PRESSURE
GRADIENT WILL MAINTAIN BREEZY SOUTH WINDS OVERNIGHT AS WELL...WHICH
WILL LIKELY KEEP TEMPS ABOVE FREEZING OVERNIGHT AND PROBABLY RISING
BEFORE SUNRISE. INITIAL SHORT WAVE LIFTS ACROSS THE AREA THURSDAY
MORNING...WITH AN AREA OF MODESTLY STEEP MID-LEVEL LAPSE RATES NOTED
ACROSS CENTRAL IL AND SOUTHERN CWA. HAVE INDICATED ISOLATED THUNDER
FAR SOUTH DURING THE MORNING PERIOD WITH THESE BETTER ELEVATED LAPSE
RATES BEFORE SOME MID-LEVEL DRYING OCCURS BEHIND THE INITIAL SHORT
WAVE. SHOWER CHANCES REMAIN RELATIVELY HIGH THROUGH THE DAY THURSDAY
IN MOIST WARM SECTOR...WITH GFS PRECIPITABLE WATER NEAR 0.9
INCHES...AND APPROACH OF SECOND SHORT WAVE/MAIN TROUGH AXIS LATER IN
THE DAY ALONG WITH APPROACH OF SURFACE COLD FRONT THURSDAY EVENING.
ECMWF REMAINS A LITTLE SLOWER WITH THE PASSAGE OF THE LOW/COLD FRONT
THURSDAY NIGHT...SO HAVE MAINTAINED POPS INTO THE NIGHT WITH A LOW
CHANCE LINGERING IN THE FAR EAST INTO EARLY FRIDAY. MILD/MOIST AIR
MASS SHOULD PUSH TEMPS UP AROUND 50 THURSDAY DESPITE CLOUDS/PRECIP.
COOLER AIR WORKS IN FRIDAY WITH WEAK HIGH PRESSURE RIDGE BEHIND
DEPARTING SYSTEM...WITH WINDS LIKELY TURNING NORTHEAST OFF THE LAKE
FRIDAY AFTERNOON KEEPING LAKESIDE LOCATIONS CHILLY AROUND 40 DEG.
GUIDANCE IN GOOD AGREEMENT IN BRINGING ANOTHER PROGRESSIVE AMPLIFIED
SHORT WAVE ACROSS THE AREA FRIDAY NIGHT/SATURDAY...WITH AN AREA OF
SURFACE LOW PRESSURE PASSING SOUTH OF THE CWA. MOST OF THE PRECIP
REMAINS SOUTH/SOUTHEAST OF THE FORECAST AREA WITH THIS FEATURE...
THOUGH HAVE INCLUDED LOW CHANCE POPS MAINLY FRIDAY NIGHT. PRECIP
TYPE COULD BE A QUESTION ESPECIALLY SOUTH WHERE IT COULD BE A
RAIN/SNOW MIX PER THICKNESS PROGS AND THERMAL PROFILES. NORTHEAST
WINDS AROUND THE NORTHERN PERIPHERY OF THE PASSING LOW WILL CONTINUE
TO HOLD TEMPS BELOW NORMAL...ESPECIALLY NEAR LAKE MICHIGAN. MODELS
CONTINUE TO DEVELOP ANOTHER DEEP LOW ACROSS THE NORTHERN PLAINS
SUNDAY/MONDAY...WITH STRONG SOUTH FLOW DEVELOPING AND OFFERING THE
PROSPECT OF WARMER WEATHER BY THE END OF THE FORECAST PERIOD.
BLENDED GUIDANCE INDICATES 55-60+ DEGREES SUNDAY AND MONDAY...THOUGH
WITH BREEZY CONDITIONS AND AN INCREASING POTENTIAL FOR RAIN MONDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* STRONG/GUSTY NORTHWEST WINDS THROUGH LATE AFTERNOON.
* POSSIBLE GUSTY SOUTH/SOUTHEAST WINDS WEDNESDAY AFTERNOON. CMS
//DISCUSSION...UPDATED 18Z...
A WEAK UPPER TROUGH IS PASSING SOUTHEAST OF THE AREA EARLY THIS
AFTERNOON. SCATTERED FLURRIES AND A FEW SNOW SHOWERS WILL END AND
BKN 4KFT CIGS WILL GRADUALLY SCATTER OUT THROUGH THE AFTERNOON
WITH SKC EXPECTED TONIGHT.
WINDS WILL REMAIN STRONG/GUSTY FROM THE NORTHWEST WITH GUSTS INTO
THE MID 20KT RANGE. SPEEDS/GUSTS WILL QUICKLY DIMINISH WITH SUNSET
AND THEN BECOME LIGHT AND VARIABLE OVERNIGHT INTO WEDNESDAY
MORNING AS A RIDGE OF HIGH PRESSURE PASSES OVER THE AREA. WINDS
WILL TURN BACK SOUTHERLY WEDNESDAY MORNING AND INCREASE IN SPEEDS
DURING THE AFTERNOON...POSSIBLY BECOMING MORE SOUTH/SOUTHEAST
LATER WEDNESDAY AFTERNOON OVER THE CHICAGO AREA TERMINALS. CMS
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH FOR WIND SPEEDS/GUSTS/DIRECTIONS THROUGH THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...CHANCE OF RA AND MVFR. MAY START AS RA/SN MIX.
THURSDAY...PERIODS OF SHRA AND SUB VFR LIKELY. GUSTY SOUTH WINDS.
FRIDAY...VFR PROBABLE. WIND SHIFT TO NORTHEAST LATE DAY. SLIGHT
CHANCE -SN FRIDAY NIGHT.
SATURDAY...VFR LIKELY. NORTHEAST TO EAST WINDS.
SUNDAY...VFR. GUSTY SOUTH-SOUTHWEST WINDS. SLIGHT CHANCE SHRA SUN.
NIGHT.
MONDAY...CHANCE SHRA AND SUB VFR. GUSTY SOUTHWEST WINDS.
RC
&&
.MARINE...
354 AM CDT
A FEW ACTIVE PERIODS COMING UP ON THE LAKE THROUGH THE END OF THE
WORK WEEK. NORTHWEST WINDS GUSTING TO 30 KT THROUGH LATE AFTERNOON
ON THE SOUTH HALF TODAY AND SMALL CRAFT CRITERIA WINDS...WITH WAVES
SUBSIDING DURING THE EVENING.
HIGH PRESSURE MOVING OVER THE LAKE TONIGHT THROUGH EARLY WEDNESDAY
WILL RESULT IN A BRIEF QUIET PERIOD. AS THE HIGH PRESSURE SLIDES
EAST ON WEDNESDAY...STRONG LOW PRESSURE WILL TAKE SHAPE ACROSS THE
CENTRAL PLAINS AND MOVE EAST. THIS WILL RESULT IN RAPIDLY INCREASING
SOUTHERLY WINDS LATE DAY WEDNESDAY THROUGH WEDNESDAY NIGHT. THE AIR
MASS WILL BE WARMING BUT STILL LOOKS TO BE MARGINALLY UNSTABLE
ENOUGH FOR A PERIOD OF GALES ON THE SOUTHERN AND CENTRAL PORTION OF
THE LAKE. HAVE NOT ISSUED A WATCH DUE TO LIMITED DURATION AND LOWER
CONFIDENCE IN PREVAILING OCCURRENCE OF GALES. WILL NEED A SMALL
CRAFT ADVISORY FOR THE NEARSHORE WATERS AND DID MENTION POTENTIAL
FOR A FEW GALE FORCE GUSTS AFTER MIDNIGHT WEDNESDAY NIGHT.
STRONG SOUTH-SOUTHWEST WINDS WILL CONTINUE THROUGH THURSDAY EVENING
AS THE LOW DRAWS NEARER. STABLE CONDITIONS WILL LIMIT
MIXING...THOUGH WINDS JUST ABOVE THE BOUNDARY LAYER COULD APPROACH
40 KT. SOME GUIDANCE CONTINUES TO KEEP MIXING ONGOING PART OF
THURSDAY ON THE NORTH HALF OF THE LAKE. HAVE OPTED TO CAP SPEEDS
BELOW GALES ON THURSDAY ACROSS THE LAKE DUE TO UNCERTAINTY WITH
MIXING. GALES ARE POSSIBLE FOR THE NEARSHORE PART OF THURSDAY DUE
TO PROXIMITY TO BETTER MIXED LAND AREA. AFTER THE LOW CROSSES THE
LAKE THURSDAY NIGHT...THE TRAILING COLD FRONT WILL SWEEP ACROSS
THE LAKE...WITH WINDS SHIFTING NORTHWEST TO 25 TO 30 KT INTO
FRIDAY BEFORE BACKING NORTHERLY AND GRADUALLY DIMINISHING IN THE
AFTERNOON. ANOTHER LOW WILL TRACK ACROSS THE OHIO VALLEY EARLY
SATURDAY AND IF IT GETS CLOSE ENOUGH TO LAKE...NORTHEAST WINDS ON
SOUTH HALF COULD BE STRONGER THAN INDICATED. WINDS WILL TURN
SOUTHERLY AND INCREASE ON SUNDAY THROUGH SUNDAY NIGHT IN ADVANCE
OF ANOTHER STRONG LOW PRESSURE AREA THAT WILL MOVE ACROSS THE
REGION ON MONDAY.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 PM TUESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1106 AM CDT TUE MAR 25 2014
.DISCUSSION...
1035 AM CDT
THERE WERE MAINLY JUST SOME TWEAKS TO HOURLY CONDITIONS FOR THE
FORECAST THE REST OF TODAY...OTHERWISE ALL IS IN GOOD SHAPE.
THE 12Z RAOBS INDICATED 850-500MB READINGS THAT WERE ABOUT AS
COLD AS THEY CAN REACH IN THIS REGION DURING LATE MARCH. THE
850-925MB COLD AIR ADVECTION IS AT IS MAX OVER THE CWA LATE THIS
MORNING...WITH -18C KNOCKING ON THE DOOR PER THE RAP ANALYSIS.
THIS AIDED BY A SHEARED SHORT WAVE LOOK TO KEEP SCATTERED LIGHT
SNOW SHOWERS/FLURRIES GOING INTO EARLY AFTERNOON. REMARKABLY DRY
LOW-LEVEL AIR LOOKS TO SPREAD IN BY MID-AFTERNOON WITH UPSTREAM
DEW POINT OBSERVATIONS IN THE LOWER TO MID SINGLE DIGITS. THE
SURFACE PRESSURE GRADIENT REMAINS TIGHT AND SOUNDINGS SUPPORT
GUSTS THROUGH THE AFTERNOON...WITH A RELAXING GRADIENT MOVING
QUICKLY IN THIS EVENING AS HIGH PRESSURE BUILDS IN FROM THE PLAINS.
MTF
//PREV DISCUSSION...
NARROW BUT INTENSE BAND OF SNOW ALONG COLD FRONT WILL CONTINUE TO
MOVE ACROSS THE SOUTHEAST HALF OF THE CWA OVER THE NEXT FEW HOURS.
GENERALLY QUICK DROP TO 1/4SM VIS WITH 0.5-1.0 INCH ACCUMULATIONS IN
20 MINUTES WITHIN THE HEAVIER SNOW SHOWERS. EXTRAPOLATION OF RADAR
LOOP INDICATES BAND SHOULD EXIT ALL BUT PERHAPS THE EXTREME
SOUTHEAST PART OF THE FORECAST AREA BY SUNRISE...WITH A FEW LIGHTER
SNOW SHOWERS ALSO ACROSS FAR NORTHEAST IL BENEATH PATH OF MID-LEVEL
VORT DURING THAT TIME. RELATIVELY DRY ARCTIC AIR SPREADING IN FROM
THE NORTHWEST WILL ALLOW SOME SCATTERING OF CLOUD COVER AND AN END
TO ACCUMULATING SNOW SHOWERS BY SUNRISE...THOUGH ONE MORE SHORT WAVE
DROPPING SOUTHEAST ACROSS MINNESOTA AT 08Z MAY BE ENOUGH TO PRODUCE
SOME ENHANCED STRATOCU AND A FEW FLURRIES ACROSS THE REGION DURING
THE MID/LATE MORNING HOURS. IN THE WAKE OF THE PASSAGE OF THIS
MID-LEVEL VORT AXIS AROUND MIDDAY...RISING HEIGHTS AND SUBSIDENCE
SHOULD RESULT IN AN END TO FLURRIES AND THINNING/EROSION OF THE
STRATOCU DECK ALLOWING PARTLY CLOUDY/MOSTLY SUNNY SKIES THIS
AFTERNOON. BLUSTERY NORTHWEST WINDS WILL KEEP TEMPS WELL BELOW
NORMAL ONCE AGAIN...WITH UPPER 20S/LOW 30S EXPECTED FOR AFTERNOON
HIGHS PER BIAS CORRECTED MOS BLEND. BROAD UPPER RIDGE BUILDS ACROSS
THE REGION TONIGHT IN THE WAKE OF OUR DEPARTING EASTERN CONUS UPPER
TROUGH WITH SURFACE HIGH PRESSURE RIDGE BUILDING INTO THE REGION
OVERNIGHT. THIS MORNINGS LIGHT SNOWFALL WILL BE GONE BY
TONIGHT...THOUGH LIGHT WINDS AND CLEAR SKIES WILL ALLOW FOR COOLING
INTO THE TEENS IN MOST AREAS BY WEDNESDAY MORNING.
SURFACE HIGH PRESSURE MOVES QUICKLY EAST OF THE FORECAST AREA
WEDNESDAY AS SURFACE PRESSURE FALLS DEVELOP ACROSS THE PLAINS AND
MISSISSIPPI VALLEY IN RESPONSE TO SURFACE LOW DEVELOPING OVER THE
DAKOTAS IN ADVANCE OF AN UPPER TROUGH OVER THE WESTERN CONUS AND
UPPER JET MAX SPREADING ACROSS THE CENTRAL AND SOUTHERN ROCKIES.
THIS RESULTS IN FAIRLY QUICK WARM ADVECTION AND MOISTURE TRANSPORT
INTO THE REGION ESPECIALLY ABOVE THE BOUNDARY LAYER AS 40-50 KT
SOUTH-SOUTHWESTERLY LOW LEVEL JET DEVELOPS BY LATE AFTERNOON.
INCREASING MID-LEVEL CLOUD COVER WILL LIKELY OFFSET SOME OF THE
WARMING AS WILL A SLIGHT SOUTHEAST COMPONENT TO THE BOUNDARY LAYER
WIND. EVEN SO...FAVOR WARMER MAV GUIDANCE OF WEDNESDAY AFTERNOON MAX
TEMPS IN THE UPPER 30S/LOWER 40S. EXCEPTION WILL BE ALONG THE
IMMEDIATE NORTH SHORE AREA...WHERE THAT SLIGHT SOUTHEAST WIND
COMPONENT MAY HOLD TEMPS IN THE MID 30S RIGHT ALONG THE LAKE. DEEPER
MOISTURE CONTINUES TO SPREAD INTO THE REGION WEDNESDAY NIGHT...AS
SURFACE LOW MOVES INTO THE UPPER MISSISSIPPI VALLEY AND A SHORT WAVE
TROUGH PROPAGATES FROM THE SOUTH CENTRAL PLAINS INTO THE WESTERN
GREAT LAKES. FORECAST SOUNDINGS DEPICT DEEP SATURATION OCCURRING
MAINLY AFTER MIDNIGHT...WITH SUFFICIENT FORCING APPROACHING SHORT
WAVE AND ISENTROPIC ASCENT/JET DIVERGENCE TO GO WITH LIKELY POPS.
THERMAL PROFILES BECOME NEARLY ISOTHERMAL NEAR 0C IN THE LOWER
LEVELS INITIALLY BEFORE WARM ADVECTION OVERWHELMS THE
COLUMN...SUGGESTING THE POTENTIAL FOR S BRIEF MIX OF RAIN/SNOW WITH
THE ONSET OF PRECIP...BUT QUICKLY TURNING TO RAIN AS 50-60 KT LOW
LEVEL JET CONTINUES TO PUMP IN WARM/MOIST AIR. TIGHT SFC PRESSURE
GRADIENT WILL MAINTAIN BREEZY SOUTH WINDS OVERNIGHT AS WELL...WHICH
WILL LIKELY KEEP TEMPS ABOVE FREEZING OVERNIGHT AND PROBABLY RISING
BEFORE SUNRISE. INITIAL SHORT WAVE LIFTS ACROSS THE AREA THURSDAY
MORNING...WITH AN AREA OF MODESTLY STEEP MID-LEVEL LAPSE RATES NOTED
ACROSS CENTRAL IL AND SOUTHERN CWA. HAVE INDICATED ISOLATED THUNDER
FAR SOUTH DURING THE MORNING PERIOD WITH THESE BETTER ELEVATED LAPSE
RATES BEFORE SOME MID-LEVEL DRYING OCCURS BEHIND THE INITIAL SHORT
WAVE. SHOWER CHANCES REMAIN RELATIVELY HIGH THROUGH THE DAY THURSDAY
IN MOIST WARM SECTOR...WITH GFS PRECIPITABLE WATER NEAR 0.9
INCHES...AND APPROACH OF SECOND SHORT WAVE/MAIN TROUGH AXIS LATER IN
THE DAY ALONG WITH APPROACH OF SURFACE COLD FRONT THURSDAY EVENING.
ECMWF REMAINS A LITTLE SLOWER WITH THE PASSAGE OF THE LOW/COLD FRONT
THURSDAY NIGHT...SO HAVE MAINTAINED POPS INTO THE NIGHT WITH A LOW
CHANCE LINGERING IN THE FAR EAST INTO EARLY FRIDAY. MILD/MOIST AIR
MASS SHOULD PUSH TEMPS UP AROUND 50 THURSDAY DESPITE CLOUDS/PRECIP.
COOLER AIR WORKS IN FRIDAY WITH WEAK HIGH PRESSURE RIDGE BEHIND
DEPARTING SYSTEM...WITH WINDS LIKELY TURNING NORTHEAST OFF THE LAKE
FRIDAY AFTERNOON KEEPING LAKESIDE LOCATIONS CHILLY AROUND 40 DEG.
GUIDANCE IN GOOD AGREEMENT IN BRINGING ANOTHER PROGRESSIVE AMPLIFIED
SHORT WAVE ACROSS THE AREA FRIDAY NIGHT/SATURDAY...WITH AN AREA OF
SURFACE LOW PRESSURE PASSING SOUTH OF THE CWA. MOST OF THE PRECIP
REMAINS SOUTH/SOUTHEAST OF THE FORECAST AREA WITH THIS FEATURE...
THOUGH HAVE INCLUDED LOW CHANCE POPS MAINLY FRIDAY NIGHT. PRECIP
TYPE COULD BE A QUESTION ESPECIALLY SOUTH WHERE IT COULD BE A
RAIN/SNOW MIX PER THICKNESS PROGS AND THERMAL PROFILES. NORTHEAST
WINDS AROUND THE NORTHERN PERIPHERY OF THE PASSING LOW WILL CONTINUE
TO HOLD TEMPS BELOW NORMAL...ESPECIALLY NEAR LAKE MICHIGAN. MODELS
CONTINUE TO DEVELOP ANOTHER DEEP LOW ACROSS THE NORTHERN PLAINS
SUNDAY/MONDAY...WITH STRONG SOUTH FLOW DEVELOPING AND OFFERING THE
PROSPECT OF WARMER WEATHER BY THE END OF THE FORECAST PERIOD.
BLENDED GUIDANCE INDICATES 55-60+ DEGREES SUNDAY AND MONDAY...THOUGH
WITH BREEZY CONDITIONS AND AN INCREASING POTENTIAL FOR RAIN MONDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CHANCE OF FLURRIES/LIGHT SNOW SHOWERS THROUGH EARLY AFTERNOON.
* STRONG/GUSTY NORTHWEST WINDS THROUGH LATE AFTERNOON. CMS
//DISCUSSION...UPDATED 12Z...
TODAY WILL BE A WINDY AND VFR DAY IN BETWEEN LOW PRESSURE MOVING
EAST AND EXPANSIVE ARCTIC HIGH PRESSURE SPREADING SOUTHEAST FROM
THE NORTHERN PLAINS. NORTHWEST WINDS WILL GUST TO THE MID-HIGH
20S KTS FROM 14 OR 15Z THROUGH MID TO LATE AFTERNOON. THE ONLY
MINOR CONCERN IS WITH AN UPPER DISTURBANCE CURRENTLY PRODUCING
ISOLATED/SCT SHSN OVER NORTHEAST IA AND SOUTHWEST WI. THIS
DISTURBANCE WILL MOVE SOUTHEAST AND LIGHT SNOW SHOWERS OR FLURRIES
COULD MOVE OVER THE AREA FROM MID TO LATE MORNING. HAVE LEFT THE
TAFS DRY...BUT WILL NEED TO MONITOR TRENDS OVER THE NEXT FEW
HOURS. BEST FORCING WILL BE MAINLY WEST/SW OF THE TAF SITES...SO
IT APPEARS RFD WOULD HAVE A BETTER BUT STILL LOW CHANCE AT
ANYTHING MORE THAN FLURRIES. FORECAST SOUNDINGS INDICATE THAT
DIURNALLY DRIVEN SCT TO BKN VFR CLOUDS WILL BE AROUND 4-5KFT AGL.
AS HIGH PRESSURE MOVES OVERHEAD TONIGHT...SKIES WILL CLEAR AND
WINDS QUICKLY DIMINISH...WITH LIGHT/VRB TO CALM OVERNIGHT INTO
EARLY WEDS. LIGHT SOUTHERLY WINDS WILL DEVELOP WEDNESDAY MORNING
AS THE HIGH PRESSURE SLIDES EAST.
RC
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM FOR FLURRIES/LIGHT SNOW SHOWERS THROUGH EARLY AFTERNOON.
* HIGH FOR WIND SPEEDS/GUSTS/DIRECTIONS THROUGH THIS EVENING. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...CHANCE OF RA AND MVFR. MAY START AS RA/SN MIX.
THURSDAY...PERIODS OF SHRA AND SUB VFR LIKELY. GUSTY SOUTH WINDS.
FRIDAY...VFR PROBABLE. WIND SHIFT TO NORTHEAST LATE DAY. SLIGHT
CHANCE -SN FRIDAY NIGHT.
SATURDAY...VFR LIKELY. NORTHEAST TO EAST WINDS.
SUNDAY...VFR. GUSTY SOUTH-SOUTHWEST WINDS. SLIGHT CHANCE SHRA SUN.
NIGHT.
MONDAY...CHANCE SHRA AND SUB VFR. GUSTY SOUTHWEST WINDS.
RC
&&
.MARINE...
354 AM CDT
A FEW ACTIVE PERIODS COMING UP ON THE LAKE THROUGH THE END OF THE
WORK WEEK. NORTHWEST WINDS GUSTING TO 30 KT THROUGH LATE AFTERNOON
ON THE SOUTH HALF TODAY AND SMALL CRAFT CRITERIA WINDS...WITH WAVES
SUBSIDING DURING THE EVENING.
HIGH PRESSURE MOVING OVER THE LAKE TONIGHT THROUGH EARLY WEDNESDAY
WILL RESULT IN A BRIEF QUIET PERIOD. AS THE HIGH PRESSURE SLIDES
EAST ON WEDNESDAY...STRONG LOW PRESSURE WILL TAKE SHAPE ACROSS THE
CENTRAL PLAINS AND MOVE EAST. THIS WILL RESULT IN RAPIDLY INCREASING
SOUTHERLY WINDS LATE DAY WEDNESDAY THROUGH WEDNESDAY NIGHT. THE AIR
MASS WILL BE WARMING BUT STILL LOOKS TO BE MARGINALLY UNSTABLE
ENOUGH FOR A PERIOD OF GALES ON THE SOUTHERN AND CENTRAL PORTION OF
THE LAKE. HAVE NOT ISSUED A WATCH DUE TO LIMITED DURATION AND LOWER
CONFIDENCE IN PREVAILING OCCURRENCE OF GALES. WILL NEED A SMALL
CRAFT ADVISORY FOR THE NEARSHORE WATERS AND DID MENTION POTENTIAL
FOR A FEW GALE FORCE GUSTS AFTER MIDNIGHT WEDNESDAY NIGHT.
STRONG SOUTH-SOUTHWEST WINDS WILL CONTINUE THROUGH THURSDAY EVENING
AS THE LOW DRAWS NEARER. STABLE CONDITIONS WILL LIMIT
MIXING...THOUGH WINDS JUST ABOVE THE BOUNDARY LAYER COULD APPROACH
40 KT. SOME GUIDANCE CONTINUES TO KEEP MIXING ONGOING PART OF
THURSDAY ON THE NORTH HALF OF THE LAKE. HAVE OPTED TO CAP SPEEDS
BELOW GALES ON THURSDAY ACROSS THE LAKE DUE TO UNCERTAINTY WITH
MIXING. GALES ARE POSSIBLE FOR THE NEARSHORE PART OF THURSDAY DUE
TO PROXIMITY TO BETTER MIXED LAND AREA. AFTER THE LOW CROSSES THE
LAKE THURSDAY NIGHT...THE TRAILING COLD FRONT WILL SWEEP ACROSS
THE LAKE...WITH WINDS SHIFTING NORTHWEST TO 25 TO 30 KT INTO
FRIDAY BEFORE BACKING NORTHERLY AND GRADUALLY DIMINISHING IN THE
AFTERNOON. ANOTHER LOW WILL TRACK ACROSS THE OHIO VALLEY EARLY
SATURDAY AND IF IT GETS CLOSE ENOUGH TO LAKE...NORTHEAST WINDS ON
SOUTH HALF COULD BE STRONGER THAN INDICATED. WINDS WILL TURN
SOUTHERLY AND INCREASE ON SUNDAY THROUGH SUNDAY NIGHT IN ADVANCE
OF ANOTHER STRONG LOW PRESSURE AREA THAT WILL MOVE ACROSS THE
REGION ON MONDAY.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 PM TUESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
1106 AM MDT TUE MAR 25 2014
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 416 AM MDT TUE MAR 25 2014
FORECAST CONCERN WILL BE THE FORECAST FROM WEDNESDAY INTO THURSDAY
NIGHT. SATELLITE SHOWING AN AMPLIFIED AND BLOCKY PATTERN FROM THE
EASTERN PACIFIC INTO NORTH AMERICA. ANOTHER COLD FRONT IS PUSHING IN
FROM THE NORTH AT THIS TIME.
AT JET LEVEL...OVERLAND THE MODELS WERE FINE. HOWEVER THE JET THAT
WILL BE AFFECTING THE AREA BEGINNING TOMORROW IS WELL OUT OVER THE
OCEAN AND IS VERY HARD TO GET A HANDLE ON. SATELLITE OBSERVATIONS
FROM OUT THERE WOULD INDICATE THE MODELS HAVE A PROPER HANDLE ON IT
AT THIS TIME WITH MAYBE THE UKMET DOING THE BEST. AT MID LEVELS...
SATELLITE WOULD INDICATE THE NAM WAS DOING A LITTLE BETTER WITH THE
COMPLICATED UPPER LOW APPROACHING THE PACIFIC NORTHWEST AND
SOUTHWEST CANADA. OTHER FEATURE OF INTEREST IS THE UPPER LOW NEAR
THE BAJA. HERE AND WOULD ALSO SAY OVERALL THAT THE CANADIAN WAS DOING
A LITTLE BETTER THAN GFS AND UKMET. THE NAM AND RUC WERE DOING A
LITTLE BETTER THAN THE ECMWF ON THE SURFACE WIND/PRESSURE FIELD.
NAM/GFS WERE DOING A LITTLE BETTER THAN THE ECMWF/CANADIAN ON THE LOW
LEVEL THERMAL FIELD.
TODAY/TONIGHT...UPPER JET MOVES RAPIDLY EAST OF THE AREA DURING THE
DAY. CURRENTLY HAVE SOME WEAK RETURNS WITH A FEW STATIONS REPORTING
FLURRIES. RADAR TRENDS AND LATEST SMALL GUIDANCE SUPPORT THIS
ACTIVITY BEING DONE BY 12Z AND WILL NOT INCLUDE IN THE MORNING
FORECAST. THICK CLOUD COVER HAS OVERSPREAD THE AREA. THIS HAS CAUSE
THE TEMPERATURES TO WARM CONSIDERABLY ABOVE THE DEWPOINTS. FORECAST
SOUNDINGS AND SMALL SCALE GUIDANCE INDICATE THAT NO FOG IS GOING TO
DEVELOP SO WILL REMOVE THAT FROM THE MORNING GRIDS.
PRESSURE GRADIENT AND 3 HOUR PRESSURE FALLS WOULD SUPPORT HAVING
BREEZY TO PROBABLY WINDY CONDITIONS...ESPECIALLY IN THE WESTERN
PORTION THIS AFTERNOON. HOW FAST IT CLEARS OUT WILL DETERMINE THE
MAXES. BELIEVE SKIES WILL CLEAR FAIRLY QUICKLY. NEWEST GUIDANCE
WOULD SUPPORT GOING WARMER. RECENTLY GUIDANCE HAS SHOWN A COOL BIAS
AS WELL. FOR TONIGHT...TIGHT GRADIENT AND SOUTHERLY WINDS/WARM
ADVECTION TONIGHT WOULD SUPPORT MILD CONDITIONS OVER MOST OF THE
AREA...ESPECIALLY IN THE EASTERN PORTION. I STILL MAY BE TOO COOL.
WEDNESDAY/WEDNESDAY NIGHT...BELIEVE MOST OF THE MODEL OUTPUT HAS
DRYLINE/SURFACE TROUGH TOO FAR EAST CONSIDERING THE FLOW ALOFT. IN
THIS INSTANCE LIKE THE ECMWF AND ITS WIND DIRECTION AND DEWPOINTS
COMBINED WITH THE SPEEDS THE NAM IS SHOWING. THE 00Z ECMWF IS MUCH
FURTHER WEST THAN ANY OTHER GUIDANCE. 06Z NAM CAME IN AND PULLED
THE DRY LINE/SURFACE TROUGH BACK FURTHER WEST. ALSO NEW NAM
DEWPOINTS MATCH VERY CLOSE WHAT THE ECMWF WAS INDICATING. PRESSURE
GRADIENT AND 3 HOUR PRESSURE FALLS WOULD SUPPORT WINDY CONDITIONS IN
AT LEAST THE EASTERN THIRD TO HALF OF THE AREA THROUGH THE DAY.
SO IN REGARDS TO FIRE WEATHER. THE DRIEST AIR WILL BE WEST OF THE
COLORADO BORDER. ALSO THAT LOOKS TO BE WHERE THE WEAKEST WINDS WILL
BE AS WELL. STRONGEST WINDS ARE FURTHER SOUTH AND EAST. CONSIDERING
AT THIS TIME RELATIVE HUMIDITIES WILL REMAIN ABOVE 20 PERCENT FOR
MOST OF THE AFTERNOON AND THE WINDS WILL NOT BE THERE...WILL NOT BE
ISSUING A WATCH. THE DAY SHIFT WILL NEED TO TAKE ANOTHER LOOK.
BY LATE TOMORROW THE MODELS HAVE THE LEFT FRONT QUADRANT TO THE
SOUTHWEST OF THE AREA. DRY LINE/SURFACE TROUGH WILL BE NEAR TO A
LITTLE WEST OF THE COLORADO BORDER. EVEN THOUGH LOW LEVEL MOISTURE
RETURN IS STILL MODEST...ONLY INTO THE LOWER TO MIDDLE 40S AT BEST...
THE MODELS ARE IN MORE AGREEMENT IN REGARDS TO THE INSTABILITY THAT
WILL BE IN PLACE. CONSIDERING THAT THE SHORTWAVE TROUGH WILL NOT
ARRIVE UNTIL LATER IN THE AFTERNOON AND THE SURFACE CONVERGENCE IS
FURTHER WEST...DELAYED THE ONSET OF THE THUNDERSTORMS AND PULLED
THEM FURTHER WEST. THE CAVEAT TO ALL THIS IS THE PASSAGE OF A
SHORTWAVE TROUGH EARLIER IN THE DAY. THAT MAY MESS THINGS UP FOR
THIS ENTIRE PERIOD.
DURING THE NIGHT A RATHER STRONG LEFT FRONT QUADRANT LOOKS TO BE
AFFECTING THE SOUTHERN HALF OF THE AREA. STRONG 700 MB SHORTWAVE
TROUGH AND ASSOCIATED PV ANOMALY START MOVING IN LATER IN THE
EVENING INTO THE OVERNIGHT HOURS. THE LIFT AND MOISTURE FROM THE
NEWER MODEL RUN SUPPORTED WHAT THE DAY SHIFT HAD IN THERE AND LEFT
IT ALONE. WHAT ENDS UP HAPPENING IS GETTING PRECIPITATION AHEAD OF
THE FEATURE WITH WRAP AROUND OCCURRING LATER IN THE NIGHT. LOOKS
LIKE MOST OF THE PRECIPITATION WILL REMAIN RAIN WITH SOME MIXTURE
POSSIBLE IN THE WEST LATE IN THE NIGHT.
BREEZY TO WINDY CONDITIONS DEVELOP BEHIND THE FRONT AND DEPARTING
SYSTEM.
THURSDAY/THURSDAY NIGHT...MAIN JET IS TO THE EAST OF THE AREA.
BREEZY TO WINDY CONDITIONS WILL CONTINUE THROUGH THE MORNING.
MODELS SHOW A HUGE SPREAD IN THE LOW LEVEL THERMAL FIELD DURING THIS
ENTIRE PERIOD. DOES NOT LIKE THERE WILL BE A CHANCE TO WARM UP A
LOT. SO WENT MORE TOWARD THE COOLER BUT NOT COLDEST SOLUTIONS. AGAIN
LOOKS LIKE A MIXTURE POSSIBLE EARLY IN THE DAY WITH MAYBE A COMPLETE
SWITCH BACK TO RAIN. THIS ROUND OF PRECIPITATION LOOKS DONE BY 18Z.
ALL THIS PRETTY MATCHES WHAT THE DAY SHIFT END THERE AND MADE LITTLE
TO NO CHANGES.
MODELS LOOK TO BRING ANOTHER SHORTWAVE TROUGH AND ANOTHER BATCH OF
PRECIPITATION IN DURING THE NIGHT. THETA-E LAPSE RATES NEAR ZERO
WILL BE IN PLACE AS STRONG MESOSCALE FORCING PLUS A STRONG PV
ANOMALY MOVE THROUGH BEGINNING LATE IN THE EVENING INTO THE
OVERNIGHT HOURS. SO ADJUSTED THE GRIDS IN REGARDS TO THIS TIMING.
A COMPLETE CHANGEOVER TO SNOW DOES NOT HAPPEN UNTIL LATE IN THE FAR
WEST. HOWEVER...BY THE TIME IT GETS COLD ENOUGH THERE MAY BE MUCH
MOISTURE AND LIFT. REMAINDER OF THE AREA WILL SEE A RAIN OR
RAIN/SNOW MIX.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 416 AM MDT TUE MAR 25 2014
THE EXTENDED WILL BE CHARACTERIZED BY A SERIES OF SHORTWAVE TROUGHS
MOVING THROUGH THE CWA AND A RIDGE THAT WILL MOVE INTO THE CENTRAL
PLAINS THIS WEEKEND. THE FIRST THING TO NOTE IS THE PRECIPITATION ON
FRIDAY MORNING. FRONTOGENESIS WEAKENS AND THE AREAS OF STRONGEST
LIFT PUSH EAST FAIRLY QUICKLY AROUND 12Z ACCORDING TO THE NAM AND
GFS. THEREFORE...DECIDED TO HAVE SILENT POPS IN THE EASTERN HALF OF
THE CWA ON FRIDAY MORNING TO ACCOUNT FOR ANY REMAINING PRECIPITATION
THAT MAY LINGER SINCE CONFIDENCE IS NOT HIGH ENOUGH TO ASSIGN A
HIGHER VALUE AT THIS TIME.
THE REMAINDER OF THE EXTENDED WILL REMAIN DRY AS THE UPPER LEVEL
RIDGE MOVES INTO THE PLAINS ON SATURDAY. THE RIDGE BEING IN PLACE
WILL ALLOW TEMPERATURES TO WARM UP QUITE NICELY OVER THE WEEKEND
WITH HIGHS ON SATURDAY IN THE UPPER 60S TO LOW 70S AND HIGHS ON
SUNDAY IN MID TO UPPER 70S APPROACHING 80 DEGREES. WHILE GETTING
INTO THE DETAILS IN THE EXTENDED IS OFTEN DIFFICULT DUE TO MODEL
SPREAD AND OTHER VARIABLES...IT LOOKS LIKE SOUTHWEST SURFACE WINDS
COULD BE HIGH ENOUGH AND RH VALUES COULD BE LOW ENOUGH ON SUNDAY
AFTERNOON FOR ELEVATED FIRE WEATHER. HOWEVER...THIS IS STILL FAR
ENOUGH OUT THAT THIS COULD CHANGE.
SOME MODELS SHOW THE STRONGEST SHORTWAVE TROUGH AFFECTING THE CWA ON
SUNDAY NIGHT. THIS SHORTWAVE TROUGH WILL MOVE THROUGH THE NORTHERN
PLAINS AND DROP A COLD FRONT THROUGH THE CWA SUNDAY NIGHT. BEHIND
THE FRONT...NORTH WINDS WILL INCREASE AND COULD BECOME QUITE GUSTY.
HOWEVER...AS PREVIOUSLY MENTIONED...THESE KINDS OF DETAILS ARE HARD
TO PIN DOWN THIS FAR OUT. DEPENDING ON HOW THIS
DEVELOPS...PRECIPITATION COULD ALSO CHANGE. DECIDED TO GO AHEAD AND
KEEP THE REST OF THE EXTENDED DRY FOR NOW BECAUSE OF MODEL
DISCREPANCIES. THEREFORE...THE THINGS TO TAKE AWAY FROM THE EXTENDED
ARE THAT IT WILL BE DRY AFTER FRIDAY MORNING AND WARM OVER THE
WEEKEND WITH A SLIGHT COOL DOWN ON MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1106 AM MDT TUE MAR 25 2014
VFR CONDITIONS ARE EXPECTED FOR THE NEXT 24 HOURS. SOUTH WINDS
BEGIN TO STRENGTHEN THIS AFTERNOON AS A SURFACE LOW DEEPENS TO
THE WEST. DRY AIR SHOULD KEEP THE SKIES CLEAR OTHER THAN SOME
CIRRUS AND POSSIBLE DAYTIME CUMULUS THIS AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...ALW
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
430 PM EDT TUE MAR 25 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 412 PM EDT TUE MAR 25 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
SRN HUDSON BAY THROUGH THE CNTRL GREAT LAKES INTO THE SE CONUS AND A
RIDGE OVER THE ROCKIES RESULTING IN NW FLOW THROUGH THE NRN GREAT
LAKES. AT THE SFC...ACYC WNW WINDS PREVAILED THROUGH UPPER MICHIGAN
AHEAD OF A RIDGE BUILDING INTO THE UPPER MS VALLEY. IN THE COLD
AIRMASS WITH 850 MB TEMPS TO AROUND -23C...DIURNAL CLOUD AND
FLURRIES HAD DEVELOPED OVER MUCH OF THE REGION. HOWEVER...LITTLE OR
NO ACCUMULATION HAS OCCURRED SINCE EARLY AFTERNOON.
TONIGHT...WITH THE LOSS OF DAYTIME HEATING...EXPECT THE LIGHT SNOW
SHOWERS OR FLURRIES TO DIMINISH AND THE CLOUDS TO ALSO GRADUALLY
DISSIPATE. AS THE HIGH PRES RIDGE BUILDS INTO THE AREA AND WINDS
BECOME LIGHT...FAVORABLE RADIATIONAL COOLING CONDITIONS WILL DEVELOP.
WITH PWAT VALUES AOB 0.10 INCH...EXPECT TEMPS WILL DROP OFF TO
VALUES WELL BELOW GUIDANCE...ESPECIALLY AT THE TYPICAL INTERIOR COLD
SPOTS. LOOK FOR LOWS BELOW ZERO OVER PRETTY MUCH ALL OF THE U.P. AND
IN THE TEENS BELOW ZERO OVER THE INTERIOR.
WEDNESDAY...WAA WILL DEVELOP AS THE PATTERN DEAMPLIFIES. DESPITE
SOME INCREASE IN MID/HIGH CLOUDS...THE COMBINATION OF SRLY FLOW AND
LIMITED SUNSHINE SHOULD BOOST TEMPS BACK INTO THE MID 20 TO AROUND
30. DURING THE AFTERNOON 285K-290K ISENTRROPIC LIFT MAY BE STRONG
ENOUGH TO PRODUCE SOME LIGHT SNOW. HOWEVER...WITH THE DRY LOWER
LEVELS...ONLY SLIGHT CHANCE POPS WERE MENTIONED LATE OVER THE WEST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 423 PM EDT TUE MAR 25 2014
A LOW PRESSURE SYSTEM MOVING THROUGH THE GREAT LAKES REGION WILL
CONTROL THE FIRST PART OF THE LONG TERM FORECAST. THIS LOW...WHICH
WILL BE AROUND 989MB IN WESTERN NEBRASKA AT 00Z THURSDAY...WILL
SLIDE AN ELONGATED TROUGH NORTHEAST THROUGH NORTHWEST MINNESOTA AT
THE SAME TIME. THIS TROUGH WILL BE ASSOCIATED WITH THE FIRST WAVE
OF PRECIPITATION ASSOCIATED WITH THE SYSTEM. AS THIS TROUGH SLIDES
EAST ON WEDNESDAY NIGHT AND OVER FAR WESTERN LAKE SUPERIOR BY 12Z
THURSDAY...BROAD WARM AIR ADVECTION ON THE 850-600MB LEVELS AND
ISENTROPIC ASCENT ON THE THE 275-295K SFCS WILL SLIDE
EAST-NORTHEAST THROUGH THE CWA. WOULD EXPECT THE SNOW TO SLIDE INTO
THE NORTHERN HALF OF THE CWA DURING THE EVENING HOURS AND THEN GET
ADDITIONAL DEVELOPMENT OVER THE EAST DURING THE OVERNIGHT HOURS AS
THE WAA BECOMES MAXIMIZED/FOCUSED THERE. QPF IN THESE WAA EVENTS IS
ALWAYS TRICKY AND THE MODELS HAVE BEEN STRUGGLING ON THE EXACT
AMOUNTS/LOCATIONS...SO HAVE FOCUSED ON WHERE THE FORCING IS
MAXIMIZED WITH THE HIGHEST POPS/QPF. IN ADDITION FOR THE
EAST...THERE MAY BE ENOUGH LINGERING COLD AIR WITH THE SOUTHERLY
WINDS OFF THE PATCH OF OPEN WATER OVER NORTHWEST LAKE MICHIGAN TO
LEAD TO A LITTLE BIT OF ENHANCEMENT. OVERALL...HAVE SNOWFALL
AMOUNTS OF 0.5-2.5 INCHES FOR THE WEDNESDAY NIGHT PERIOD...WITH THE
LOWEST VALUES ALONG THE WI BORDER AND THE HIGHEST OVER THE KEWEENAW
AND LUCE COUNTIES. ONE ITEM OF NOTE IS THE MODELS ARE SHOWING THE
DEEP MOISTURE CUTTING OUT FROM THE SOUTH DURING THE OVERNIGHT HOURS.
THIS WOULD LEAD TO A TRANSITION TO A FREEZING RAIN/DRIZZLE SITUATION
UNTIL THE LOW LEVEL TEMPERATURES CAN WARM ON THURSDAY MORNING.
HEADING INTO THURSDAY...THE SURFACE TROUGH WILL SHIFT EAST ACROSS
THE CWA WHILE THE SURFACE LOW IS MOVING NORTHEAST INTO
SOUTHERN WISCONSIN BY THURSDAY EVENING. 12Z GFS REMAINS THE FASTEST
SOLUTION AND MOVING THE LOW NORTHEAST THROUGH NORTHWEST LOWER
MICHIGAN THURSDAY EVENING...WHILE THE NAM IS WAY TO THE NW. THE 12Z
GEM/ECMWF MEANWHILE ARE MUCH SLOWER AND TRACK THE LOW THROUGH THE
NORTHERN/CENTRAL OF LOWER MICHIGAN RESPECTIVELY LATE THURSDAY
NIGHT. WITH THE EXTREMELY WELL CLUSTERED 00Z ECMWF ENSEMBLE MEMBERS
ON THE LOW TRACK...HAVE A HARD TIME GOING MUCH AWAY FROM THAT IDEA
ALTHOUGH THE 12Z ECMWF WAS FARTHER SOUTHEAST. THUS...LIKE YESTERDAY
WILL FOLLOW THE SLOWER IDEA FOR TIMING AND THEN A BLEND OF THE
ECMWF/GFS/GEM FOR THE LOW TRACK.
AS FOR HOW THE PRECIPITATION WILL EVOLVE...EXPECT THERE TO BE SOME
WAA PRECIPITATION CONTINING INTO THE MORNING HOURS OVER THE EASTERN
CWA...BUT MODELS DO HINT AT THE DEEPER MOISTURE BEGINNING TO CUT
OUT OVER THE REST OF WESTERN/CENTRAL CWA AND WOULD EXPECT A
TRANSITION AWAY FROM SNOW AND TOWARDS A MIX OR RAIN/DRIZZLE. THAT
SIMILAR IDEA OF LIQUID PRECIP FOR THE MORNING SEEMS REASONABLE WITH
THE LACK OF DEEP MOISTURE AND MUCH OF THE CLOUD LAYER BELOW THE
FAVORED ICE CRYSTAL TEMPERATURES. SINCE THIS IDEA HAS BEEN SHOWN
OVER THE LAST DAY...TRANSITIONED THAT AREA TO MORE RAIN/DRIZZLE THAN
SNOW FOR THURSDAY MORNING. SURFACE TEMPERATURES WILL BE NEAR OR
SLIGHTLY BELOW FREEZING AT INITIALLY THURSDAY MORNING...SO THERE
COULD BE A FEW HOUR PERIOD OF FREEZING DRIZZLE...BUT WITH SOME
SNOW LIKELY OCCURRING EARLIER THE IMPACTS SHOULD BE LIMITED. FARTHER
WEST...WOULD EXPECT THERE TO BE A STRONG BAND OF PRECIPITATION
(MAINLY SNOW) ALONG THE WEST SIDE OF THE SURFACE TROUGH. THIS BAND
WILL BE OVER WESTERN LAKE SUPERIOR LATE WEDNESDAY NIGHT AND THEN
SHIFT EAST AND ONSHORE OVER THE FAR WEST ON THURSDAY MORNING. THIS
EASTWARD SHIFT WILL CONTINUE THROUGH THE AFTERNOON/EVENING HOURS
ACROSS THE REST OF THE CWA AND WOULD EXPECT SOME INTENSIFICATION OF
THE BAND DUE TO THE SHORTWAVE TROUGH EXPECTED TO PULL NORTHEAST WITH
THE SURFACE LOW AND INTO THE GREAT LAKES REGION. OUR CWA WILL BE ON
THE NORTHERN EDGE OF THAT WAVE...BUT THERE SHOULD STILL BE SOME
INFLUENCE. THEN AS THE LOW PULLS OUT OF LOWER MICHIGAN LATE THURSDAY
NIGHT AND FRIDAY MORNING...THE PRECIPITATION WILL FOLLOW SUIT AND
SHOULD BE MAINLY OUT OF THE CWA BY 12Z FRIDAY. THERE COULD BE SOME
LIGHT UPSLOPE SNOW UNDER THE NW WINDS ON FRIDAY OVER THE NW/NC U.P.
BUT WITH LITTLE HELP FROM LAKE ENHANCEMENT (MARGINAL 850MB TEMPS
AROUND -10C)...LITTLE OPEN WATER...AND DRY AIR MOVING IN FROM THE
APPROACHING HIGH WILL QUICKLY DIMINISH POPS FRIDAY MORNING.
NOW FOR PCPN AMOUNTS/TYPE. QPF AMOUNTS FOR THURSDAY INTO THURSDAY
NIGHT WILL LIKELY BE AROUND 0.33-0.66 (HEAVIEST EAST)...BUT THERE
COULD BE SOME LOCALIZED HIGHER AMOUNTS IN ANY BANDED LOCATIONS ALONG
THE SURFACE TROUGH. WITH DIFFERING IDEAS FROM THE MODELS ON HOW TO
HANDLE THE LOW-MID LEVEL WARMING...HAVE BEEN STRUGGLING WITH HOW
MUCH RAIN TO PUT IN THE FORECAST. GEM CONTINUES TO SHOW THE WARMEST
THERMAL PROFILE AND WOULD PUT RAIN OVER MUCH OF THE CWA. ECMWF/GFS
IN DECENT AGREEMENT THROUGH MUCH OF THURSDAY BEFORE THE FASTER GFS
QUICKLY PULLS COLD AIR INTO THE CWA. THE ECMWF SOLUTION WOULD KEEP
THE PRECIPITATION ASSOCIATED WITH THE FGEN/TROUGH AS MAINLY SNOW
AND THAT SEEMS REASONABLE WITH THE EXPECTED INTENSITY AS THAT
STRONGER BAND MOVES THROUGH. BEFORE THE TROUGH ARRIVES AND THE
EXPECTED LOSS OF DEEP MOISTURE...WILL HOLD ONTO SOME RAIN OVER
THE CENTRAL AND SHIFT IT EAST THROUGH THE DAY. OVER THE SOUTH
CENTRAL (MENOMINEE COUNTY)...THINK THEY WOULD HAVE BEST OPPORTUNITY
TO SEE AT LEAST HALF OF THE THURSDAY AFTERNOON PRECIP AS RAIN UNTIL
THE COLD AIR SURGES IN THURSDAY EVENING. THE P-TYPE MAKES THE
SNOWFALL FORECAST TRICKY...BUT THE GOING FORECAST HAS 1-4 INCHES
OVER MOST OF THE AREA AND SOME HIGHER AMOUNTS WHERE THE PRECIP WILL
BE ALL SNOW (KEWEENAW PENINSULA AND LUCE COUNTY). WILL CONTINUE TO
MENTION IN THE HWO...ALTHOUGH ADJUST THE WORDING TO HIGHLIGHT THE
FREEZING RAIN POTENTIAL LATE WEDNESDAY NIGHT INTO THURSDAY MORNING.
ALL IN ALL...IT APPEARS THAT IT WILL MAINLY BE AN ADVISORY TYPE
EVENT.
AS FOR THE REST OF THE FORECAST PERIOD...THE HIGH PRESSURE RIDGE
WILL LEAD TO CLEARING SKIES ON FRIDAY AFTERNOON/EVENING AND A QUIET
PERIOD OF WEATHER HEADING INTO SATURDAY. A TRANSITION TO MORE ZONAL
FLOW ON SATURDAY COULD SET THE STAGE FOR A BRIEF PERIOD OF PRECIP
ASSOCIATED WITH A SHORTWAVE MOVING EAST ALONG THE US/CANADIAN
BORDER ON SATURDAY NIGHT. BEST OPPORTUNITY WOULD BE OVER THE
NORTHERN HALF OF LAKE SUPERIOR AND WILL ONLY HAVE SLIGHT CHANCES
OVER THE NORTHERN PART OF THE CWA. WARM SOUTHWESTERLY FLOW AHEAD OF
A COLD FRONT THAT WILL MOVE THROUGH ON SUNDAY NIGHT WILL LEAD TO
NORMAL TO ABOVE NORMAL HIGHS ON SUNDAY. ECMWF/GEM CONTINUE TO
HANDLE HIGHS WELL THIS DAY (MID-UPPER 40S OVER THE WEST HALF OF
UPPER MICHIGAN)...WHILE THE GFS IS HEAVILY BIASED BY ITS SNOW COVER
KEEPING TEMPS DOWN. WILL CONTINUE TO FOCUS ON GEM/ECMWF TEMPS FOR
HIGHS.
AS THE COLD FRONT MOVES THROUGH ON SUNDAY NIGHT...SHOULD SEE SOME
PRECIPITATION ASSOCIATED WITH IT. THERMAL PROFILE WOULD SUPPORT
RAIN TRANSITIONING TO SNOW FROM WEST TO EAST THROUGH THE NIGHT AND
INTO MONDAY MORNING. MODELS DIFFER MORE ON THE EVOLUTION OF THE
UPPER TROUGH AND ASSOCIATED SURFACE LOW HEADING INTO MONDAY...WITH
THE 12Z ECMWF DIGGING IT MUCH FARTHER SOUTH (MID MISSISSIPPI
VALLEY) WHILE THE 12Z GFS HAS IT IN THE GREAT LAKES REGION. WILL
FOLLOW A GENERAL BLEND OF THE TWO FOR NOW. BEHIND THE WAVE...HIGH
PRESSURE WILL START TO MOVE IN ON TUESDAY AND TEMPERATURES WILL FALL
BACK TO BELOW NORMAL VALUES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 153 PM EDT TUE MAR 25 2014
MAINLY DIURNAL SCT LIGHT SNOW SHOWERS AND FLURRIES WILL CONTINUE
THIS AFTERNOON AND DIMINISH BY EVENING. CIGS SHOULD REMAIN NEAR THE
MVFR THRESHOLD BUT GIVE WAY TO CLEARING THIS EVENING AS HIGH PRES
BUILDS INTO THE REGION AND WINDS BACK TO THE WSW. IMPROVEMENT MAY
BE SLOWER AT KCMX WITH UPSLOPE/ONSHORE WRLY FLOW INITIALLY EXPECTED
THIS EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 412 PM EDT TUE MAR 25 2014
WINDS WILL QUICKLY DIMINISH TONIGHT AND WEDNESDAY AS ANOTHER HIGH
PRESSURE RIDGE MOVES OVER THE AREA. A LOW PRESSURE SYSTEM DEVELOPING
IN THE CENTRAL PLAINS ON WEDNESDAY NIGHT AND THURSDAY WILL MOVE
THROUGH THE GREAT LAKES REGION LATE THURSDAY NIGHT AND FRIDAY.
AHEAD OF THE LOW...SRLY WINDS WILL INCREASE TO 20 TO 25 KNOTS.
THEN...EXPECT NRLY WINDS 20 TO 30 KTS ON THE BACK SIDE OF THE LOW
THU NIGHT INTO FRI MORNING WITH THE STRONGEST WINDS OVER ERN LAKE
SUPERIOR. WINDS WILL QUICKLY DIMINISH FM THE WEST FRI AFTERNOON INTO
SAT AS HIGH PRESSURE BUILDS OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
412 PM EDT TUE MAR 25 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 412 PM EDT TUE MAR 25 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
SRN HUDSON BAY THROUGH THE CNTRL GREAT LAKES INTO THE SE CONUS AND A
RIDGE OVER THE ROCKIES RESULTING IN NW FLOW THROUGH THE NRN GREAT
LAKES. AT THE SFC...ACYC WNW WINDS PREVAILED THROUGH UPPER MICHIGAN
AHEAD OF A RIDGE BUILDING INTO THE UPPER MS VALLEY. IN THE COLD
AIRMASS WITH 850 MB TEMPS TO AROUND -23C...DIURNAL CLOUD AND
FLURRIES HAD DEVELOPED OVER MUCH OF THE REGION. HOWEVER...LITTLE OR
NO ACCUMULATION HAS OCCURRED SINCE EARLY AFTERNOON.
TONIGHT...WITH THE LOSS OF DAYTIME HEATING...EXPECT THE LIGHT SNOW
SHOWERS OR FLURRIES TO DIMINISH AND THE CLOUDS TO ALSO GRADUALLY
DISSIPATE. AS THE HIGH PRES RIDGE BUILDS INTO THE AREA AND WINDS
BECOME LIGHT...FAVORABLE RADIATIONAL COOLING CONDITIONS WILL DEVELOP.
WITH PWAT VALUES AOB 0.10 INCH...EXPECT TEMPS WILL DROP OFF TO
VALUES WELL BELOW GUIDANCE...ESPECIALLY AT THE TYPICAL INTERIOR COLD
SPOTS. LOOK FOR LOWS BELOW ZERO OVER PRETTY MUCH ALL OF THE U.P. AND
IN THE TEENS BELOW ZERO OVER THE INTERIOR.
WEDNESDAY...WAA WILL DEVELOP AS THE PATTERN DEAMPLIFIES. DESPITE
SOME INCREASE IN MID/HIGH CLOUDS...THE COMBINATION OF SRLY FLOW AND
LIMITED SUNSHINE SHOULD BOOST TEMPS BACK INTO THE MID 20 TO AROUND
30. DURING THE AFTERNOON 285K-290K ISENTRROPIC LIFT MAY BE STRONG
ENOUGH TO PRODUCE SOME LIGHT SNOW. HOWEVER...WITH THE DRY LOWER
LEVELS...ONLY SLIGHT CHANCE POPS WERE MENTIONED LATE OVER THE WEST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 522 AM EDT TUE MAR 25 2014
S WINDS OF WEDNESDAY WILL HELP RAISE TEMPS ABOUT 10F HIGHER THAN
WHAT WILL BE EXPERIENCED TODAY ACROSS THE CWA...ESPECIALLY W AND N.
THIS WILL BE DESPITE SNOW NEARING FROM THE NW. KEPT A SLIGHT CHANCE
FAR W BY LATE AFTERNOON...ALTHOUGH THE TREND IS TO SLOW DOWN THE
POPS EVEN MORE.
ANOTHER DAY CLOSER TO OUR WEDNESDAY NIGHT THROUGH THURSDAY EVENING
EVENT. WHILE FCST SOLUTIONS HAVE COME A BIT MORE IN LINE...THEY
COULD BE BETTER. EXPECT SIGNIFICANT IMPROVEMENTS AT THE DISTURBANCE
MOVES FROM THE PACIFIC OVER THE BETTER SAMPLED/MODELED CONTINENTAL
U.S. WILL CONTINUE TO MINIMIZE THE USE OF THE NAM PAST 18Z THURSDAY
AS IT STILL IS AN OUTLIER WITH REGARDS TO THE STRENGTHENING OF THE N
EXTENT OF THE LOW AND IS QUICKEST TO SHIFT IT TO E QUEBEC THURSDAY
EVENING. WHILE THE 18Z GFS LINED UP BETTER WITH THE NEW 00Z RUN OF
THE ECMWF...THE 00Z GFS CONTINUED WITH THE QUICKER SOLUTION AGAIN.
THE CONSENSUS IS TO HAVE THE LOW SITUATED OVER THE CENTRAL PLAINS AT
06Z THURSDAY...WITH THE INVERTED TROUGH STRETCHING UP THROUGH N MN
AND W LAKE SUPERIOR. THE WEAKENING LOW WILL THEN MOVE ACROSS IA AND
S WI BY 00Z FRIDAY...BEFORE CROSSING LOWER MI OVERNIGHT. AS NOTED
ABOVE THE GFS HITS THE GAS ON THIS ONE...MOVING E OF LAKE HURON BY
12Z FRIDAY...WHILE THE ECMWF IS OVER S LOWER MI AND CENTRAL LAKE
HURON.
WHILE EXPECTED TO BE ALL SNOW THROUGH 12Z THURSDAY...THE POTENTIAL
EXISTS FOR SOME MIXING IN OF RAIN OR SLEET ALONG THE WI BORDER. THE
FOCUS FOR HEAVY WET SNOW WILL BE OVER THE TIP OF THE KEWEENAW
PENINSULA WEDNESDAY NIGHT.
TEMPS WERE RAISED SLIGHTLY FOR THURSDAY MORNING /STILL IN THE 20S/.
THEY SHOULD QUICKLY RISE ABOVE 32F AFTER 12Z...DIMINISHING THE NEED
FOR FREEZING RAIN IN THE FCST. AS A RESULT...IT LOOKS TO BE A MAINLY
RAIN OR SNOW EVENT. WILL KEEP THE MENTION OF MODERATE WET SNOW...AND
MIXED PRECIP IN THE HWO. CONTINUE TO EXPECT THE MOST SNOW N AS WARM
AIR SURGES IN FROM THE S. RAIN MAY RUN ACROSS MUCH OF THE
CWA...EXCLUDING THE KEWEENAW PENINSULA WITH THE BEST CHANCE
STRETCHING FROM WATERSMEET TO ESC AND ISQ FROM 15-21Z THURSDAY. FOR
THURSDAY THROUGH THURSDAY NIGHT 3-6IN OF SNOW WILL BE POSSIBLE
ACROSS MUCH OF THE CWA...WITH MORE LIKE 2-3IN ACROSS MENOMINEE
COUNTY.
ANOTHER CONUNDRUM IS WHEN TO DIMINISH POPS. YES COLD AIR WILL BE
RUSHING IN BEHIND THE EXITING LOW THURSDAY NIGHT...BUT THE ECMWF
ONLY HAS TEMPS FALLING TO AROUND -9C BY 12Z FRIDAY ON FAVORABLE N
WINDS. WITH THE MAIN SHORTWAVE EXITING E UPPER MI AT THAT TIME AND
ZONAL FLOW ALOFT...THE COLDEST AIR WILL REMAIN ACROSS ONTARIO. DRY
HIGH PRESSURE OVER S CANADA AND THE N PLAINS WILL SLOWLY EDGE IN FOR
LATE FRIDAY AFTERNOON THROUGH THE DAY SATURDAY...WITH LITTLE TO NO
SNOW ANTICIPATED.
AN ELONGATED TROUGH EXTENDING FROM THE MAIN SFC-500MB LOW OVER
HUDSON BAY SUNDAY WILL SHIFT ACROSS UPPER MI...BRINGING THE NEXT
CHANCE RAIN AND SNOW TO THE CWA...BUT NOT BEFORE TEMPS BRIEFLY WARM
INTO THE 40S SUNDAY AFTERNOON.
INCREASED POPS FOR DAY 6/MONDAY AS THE NEXT SFC LOW TRACKS FROM THE
N AND CENTRAL PLAINS SUNDAY AFTERNOON TO THE UPPER GREAT LAKES BY
12Z MONDAY. COMPARING THE 00Z RUNS...THE GFS HAS THE 996MB LOW NEAR
IWD...WHILE THE ECMWF CENTERS THE LOW ACROSS IA. WITH EITHER
SOLUTION...THE BEST CHANCE OF PRECIP LOOKS TO BE W UPPER MI. HAVE
ADDED LIKELY POPS FOR THE KEWEENAW PENINSULA FOR THE DAY MONDAY. AS
FOR SPECIFICS...WE WILL NEED TO WAIT. THE N SOLUTION WOULD BRING
MAINLY RAIN TO THE CWA...WHILE THE ECMWF WOULD RESULT IN MOSTLY
SNOW. WILL KEEP A MIX IN FOR NOW WITH THE BEST CHANCE OF SNOW NW
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 153 PM EDT TUE MAR 25 2014
MAINLY DIURNAL SCT LIGHT SNOW SHOWERS AND FLURRIES WILL CONTINUE
THIS AFTERNOON AND DIMINISH BY EVENING. CIGS SHOULD REMAIN NEAR THE
MVFR THRESHOLD BUT GIVE WAY TO CLEARING THIS EVENING AS HIGH PRES
BUILDS INTO THE REGION AND WINDS BACK TO THE WSW. IMPROVEMENT MAY
BE SLOWER AT KCMX WITH UPSLOPE/ONSHORE WRLY FLOW INITIALLY EXPECTED
THIS EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 412 PM EDT TUE MAR 25 2014
WINDS WILL QUICKLY DIMINISH TONIGHT AND WEDNESDAY AS ANOTHER HIGH
PRESSURE RIDGE MOVES OVER THE AREA. A LOW PRESSURE SYSTEM DEVELOPING
IN THE CENTRAL PLAINS ON WEDNESDAY NIGHT AND THURSDAY WILL MOVE
THROUGH THE GREAT LAKES REGION LATE THURSDAY NIGHT AND FRIDAY.
AHEAD OF THE LOW...SRLY WINDS WILL INCREASE TO 20 TO 25 KNOTS.
THEN...EXPECT NRLY WINDS 20 TO 30 KTS ON THE BACK SIDE OF THE LOW
THU NIGHT INTO FRI MORNING WITH THE STRONGEST WINDS OVER ERN LAKE
SUPERIOR. WINDS WILL QUICKLY DIMINISH FM THE WEST FRI AFTERNOON INTO
SAT AS HIGH PRESSURE BUILDS OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
154 PM EDT TUE MAR 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM EDT TUE MAR 25 2014
LATEST 08Z WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL
RIDGE OVER WRN NOAM AND A TROUGH FROM HUDSON BAY THROUGH MUCH OF THE
ERN CONUS. A SHORTWAVE ROTATING INTO WRN LAKE SUPERIOR PUSHED AN
ARCTIC COLD FRONT THROUGH WRN UPR MI EARLY THIS MORNING. NW OF LAKE
SUPERIOR IN THE WAKE OF THE FRONT...TEMPS ARE GENERALLY AT OR BELOW
ZERO. THIS COLDER AIR MOVING ACROSS LAKE SUPERIOR HAS GENERATED SOME
SCT -SHSN DOWNWIND OF THE LAKE IN A NW FLOW.
TODAY...AS THE SFC HIGH PRESSURE RIDGE AND ASSOC SUBSIDENCE BUILD
INTO THE WRN LAKES LATE THIS MORNING INTO THE AFTERNOON...SOUNDINGS
DRY FM 850-700 MB AND WINDS BACK WRLY...EXPECT LAKE SHSN TO DIMINISH
WITH ACCUMULATIONS GENERALLY AN INCH OR LESS. WITH 925/850 MB TEMPS
ONLY TO AROUND -18/-23C...TEMPS MAY STRUGGLE TO REACH THE LOWER TO
MID TEENS ALONG LAKE SUPERIOR...MORE THAN 20 DEGREES BELOW SEASONAL
AVERAGES.
TONIGHT...A HIGH PRESSURE RIDGE MOVING OVER THE UPPER GREAT LAKES
REGION WILL LEAD TO ANOTHER VERY COLD NIGHT TONIGHT ACROSS THE AREA.
WITH WINDS BACKING WSW WOULD NOT THINK LINGERING LAKE CLOUDS SHOULD
NOT BE A FCST CONCERN. THUS...WOULD EXPECT CLEARING SKIES AND IDEAL
RADIATIONAL COOLING CONDITIONS UNDER LIGHT WINDS. SINCE PWAT VALUES
ARE EXPECTED AROUND 30 PERCENT OF NORMAL...CONTINUED TO FCST MIN
TEMPS BLO GUIDANCE...ESPECIALLY IN THE TRADITIONAL INTERIOR COLD
SPOTS. LOOK FOR LOWS BELOW ZERO OVER PRETTY MUCH ALL OF THE U.P. AND
IN THE TEENS BELOW ZERO OVER THE INTERIOR. BASED OFF THE TRENDS IN
THE LONGER RANGE MODELS...THIS WILL LIKELY BE THE LAST REALLY COLD
NIGHT ACROSS THE REGION THIS SEASON.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 522 AM EDT TUE MAR 25 2014
S WINDS OF WEDNESDAY WILL HELP RAISE TEMPS ABOUT 10F HIGHER THAN
WHAT WILL BE EXPERIENCED TODAY ACROSS THE CWA...ESPECIALLY W AND N.
THIS WILL BE DESPITE SNOW NEARING FROM THE NW. KEPT A SLIGHT CHANCE
FAR W BY LATE AFTERNOON...ALTHOUGH THE TREND IS TO SLOW DOWN THE
POPS EVEN MORE.
ANOTHER DAY CLOSER TO OUR WEDNESDAY NIGHT THROUGH THURSDAY EVENING
EVENT. WHILE FCST SOLUTIONS HAVE COME A BIT MORE IN LINE...THEY
COULD BE BETTER. EXPECT SIGNIFICANT IMPROVEMENTS AT THE DISTURBANCE
MOVES FROM THE PACIFIC OVER THE BETTER SAMPLED/MODELED CONTINENTAL
U.S. WILL CONTINUE TO MINIMIZE THE USE OF THE NAM PAST 18Z THURSDAY
AS IT STILL IS AN OUTLIER WITH REGARDS TO THE STRENGTHENING OF THE N
EXTENT OF THE LOW AND IS QUICKEST TO SHIFT IT TO E QUEBEC THURSDAY
EVENING. WHILE THE 18Z GFS LINED UP BETTER WITH THE NEW 00Z RUN OF
THE ECMWF...THE 00Z GFS CONTINUED WITH THE QUICKER SOLUTION AGAIN.
THE CONSENSUS IS TO HAVE THE LOW SITUATED OVER THE CENTRAL PLAINS AT
06Z THURSDAY...WITH THE INVERTED TROUGH STRETCHING UP THROUGH N MN
AND W LAKE SUPERIOR. THE WEAKENING LOW WILL THEN MOVE ACROSS IA AND
S WI BY 00Z FRIDAY...BEFORE CROSSING LOWER MI OVERNIGHT. AS NOTED
ABOVE THE GFS HITS THE GAS ON THIS ONE...MOVING E OF LAKE HURON BY
12Z FRIDAY...WHILE THE ECMWF IS OVER S LOWER MI AND CENTRAL LAKE
HURON.
WHILE EXPECTED TO BE ALL SNOW THROUGH 12Z THURSDAY...THE POTENTIAL
EXISTS FOR SOME MIXING IN OF RAIN OR SLEET ALONG THE WI BORDER. THE
FOCUS FOR HEAVY WET SNOW WILL BE OVER THE TIP OF THE KEWEENAW
PENINSULA WEDNESDAY NIGHT.
TEMPS WERE RAISED SLIGHTLY FOR THURSDAY MORNING /STILL IN THE 20S/.
THEY SHOULD QUICKLY RISE ABOVE 32F AFTER 12Z...DIMINISHING THE NEED
FOR FREEZING RAIN IN THE FCST. AS A RESULT...IT LOOKS TO BE A MAINLY
RAIN OR SNOW EVENT. WILL KEEP THE MENTION OF MODERATE WET SNOW...AND
MIXED PRECIP IN THE HWO. CONTINUE TO EXPECT THE MOST SNOW N AS WARM
AIR SURGES IN FROM THE S. RAIN MAY RUN ACROSS MUCH OF THE
CWA...EXCLUDING THE KEWEENAW PENINSULA WITH THE BEST CHANCE
STRETCHING FROM WATERSMEET TO ESC AND ISQ FROM 15-21Z THURSDAY. FOR
THURSDAY THROUGH THURSDAY NIGHT 3-6IN OF SNOW WILL BE POSSIBLE
ACROSS MUCH OF THE CWA...WITH MORE LIKE 2-3IN ACROSS MENOMINEE
COUNTY.
ANOTHER CONUNDRUM IS WHEN TO DIMINISH POPS. YES COLD AIR WILL BE
RUSHING IN BEHIND THE EXITING LOW THURSDAY NIGHT...BUT THE ECMWF
ONLY HAS TEMPS FALLING TO AROUND -9C BY 12Z FRIDAY ON FAVORABLE N
WINDS. WITH THE MAIN SHORTWAVE EXITING E UPPER MI AT THAT TIME AND
ZONAL FLOW ALOFT...THE COLDEST AIR WILL REMAIN ACROSS ONTARIO. DRY
HIGH PRESSURE OVER S CANADA AND THE N PLAINS WILL SLOWLY EDGE IN FOR
LATE FRIDAY AFTERNOON THROUGH THE DAY SATURDAY...WITH LITTLE TO NO
SNOW ANTICIPATED.
AN ELONGATED TROUGH EXTENDING FROM THE MAIN SFC-500MB LOW OVER
HUDSON BAY SUNDAY WILL SHIFT ACROSS UPPER MI...BRINGING THE NEXT
CHANCE RAIN AND SNOW TO THE CWA...BUT NOT BEFORE TEMPS BRIEFLY WARM
INTO THE 40S SUNDAY AFTERNOON.
INCREASED POPS FOR DAY 6/MONDAY AS THE NEXT SFC LOW TRACKS FROM THE
N AND CENTRAL PLAINS SUNDAY AFTERNOON TO THE UPPER GREAT LAKES BY
12Z MONDAY. COMPARING THE 00Z RUNS...THE GFS HAS THE 996MB LOW NEAR
IWD...WHILE THE ECMWF CENTERS THE LOW ACROSS IA. WITH EITHER
SOLUTION...THE BEST CHANCE OF PRECIP LOOKS TO BE W UPPER MI. HAVE
ADDED LIKELY POPS FOR THE KEWEENAW PENINSULA FOR THE DAY MONDAY. AS
FOR SPECIFICS...WE WILL NEED TO WAIT. THE N SOLUTION WOULD BRING
MAINLY RAIN TO THE CWA...WHILE THE ECMWF WOULD RESULT IN MOSTLY
SNOW. WILL KEEP A MIX IN FOR NOW WITH THE BEST CHANCE OF SNOW NW
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 153 PM EDT TUE MAR 25 2014
MAINLY DIURNAL SCT LIGHT SNOW SHOWERS AND FLURRIES WILL CONTINUE
THIS AFTERNOON AND DIMINISH BY EVENING. CIGS SHOULD REMAIN NEAR THE
MVFR THRESHOLD BUT GIVE WAY TO CLEARING THIS EVENING AS HIGH PRES
BUILDS INTO THE REGION AND WINDS BACK TO THE WSW. IMPROVEMENT MAY
BE SLOWER AT KCMX WITH UPSLOPE/ONSHORE WRLY FLOW INITIALLY EXPECTED
THIS EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 455 AM EDT TUE MAR 25 2014
EXPECT NW WINDS 20 TO 30 KTS TODAY IN THE WAKE OF AN ARCTIC COLD
FRONT...WITH THE HIGHEST GUSTS OVER THE EASTERN HALF OF LAKE
SUPERIOR. WINDS WILL QUICKLY DIMINISH TONIGHT AND WEDNESDAY AS
ANOTHER HIGH PRESSURE RIDGE MOVES OVER THE AREA. A LOW PRESSURE
SYSTEM DEVELOPING IN THE CENTRAL PLAINS ON WEDNESDAY NIGHT AND
THURSDAY WILL MOVE THROUGH THE GREAT LAKES REGION LATE THURSDAY
NIGHT AND FRIDAY. EXPECT NRLY WINDS 20 TO 30 KTS ON THE BACK SIDE OF
THE LOW THU NIGHT INTO FRI MORNING WITH THE STRONGEST WINDS OVER ERN
LAKE SUPERIOR. WINDS WILL QUICKLY DIMINISH FM THE WEST FRI AFTERNOON
INTO SAT AS HIGH PRESSURE BUILDS OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KF
AVIATION...JLB
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
118 PM EDT TUE MAR 25 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 322 AM EDT TUE MAR 25 2014
A NARROW BAND OF SNOW SHOWERS WILL CONTINUE TO PUSH THROUGH THE AREA
THROUGH THE EARLY HOURS THIS MORNING. THIS BAND OF SNOW SHOWERS IS
AT THE LEADING EDGE OF A REINFORCING SHOT OF ARCTIC AIR COMING IN
FROM THE NORTHWEST. SNOW SHOWERS WILL REMAIN LIKELY INTO THIS
AFTERNOON BEFORE THEY START TO DIMINISH AND MIGRATE CLOSER TO LAKE
MICHIGAN TONIGHT.
ANOTHER COLD DAY IS EXPECTED ON WEDNESDAY BEFORE A TREND OF MILDER
WEATHER CAN BE EXPECTED INTO LATER THIS WEEK. ANOTHER BATCH OF SNOW
WILL MOVE IN WEDNESDAY NIGHT BEFORE CHANGING TO RAIN ON THURSDAY AS
THE WARMER AIR MOVES IN. THIS RAIN COMBINED WITH SNOW MELT IS
EXPECTED TO INCREASE RIVER LEVELS ACROSS THE AREA. ANOTHER BATCH OF
COOLER AIR WILL COME IN FOR THE FRI AND SAT BEFORE MUCH WARMER
TEMPERATURES WILL BE POSSIBLE.
&&
.UPDATE...
ISSUED AT 1120 AM EDT TUE MAR 25 2014
STEEP LOW LEVEL LAPSE RATES... ENHANCED BY SMALL CLEAR SLOT BEHIND
THE DEPARTING COLD FRONT AND INCOMING H8 AIR AROUND -17C... WILL AID
IN THE DEVELOPMENT OF SOME FAIRLY INTENSE SNOW SHOWERS TODAY.
LAPS AND RAP FCST SOUNDINGS SHOW RELATIVELY DEEP MIXED LAYER UP TO
9000 FT AND EVEN SFC BASED CAPES OF 100-200 J/KG. THERE IS ANOTHER
PV ANOMALY SWINGING THROUGH THIS AFTERNOON TO AID IN LIFT. RADAR
LATE THIS MORNING HAS A VERY SPRINGLIKE LOOK WITH SMALL BUT
INTENSE OPEN CELLULAR CONVECTION.
HAVE UPDATED THE FCST TO REMOVE THE LIGHT INTENSITY QUALIFIER FOR
THE NUMEROUS SNOW SHOWERS THIS AFTERNOON AND TO FRESHEN WORDING AS
THE EARLIER SYNOPTIC EVENT HAS ENDED. ANY ADDITIONAL ACCUMULATIONS
THIS AFTERNOON WILL BE RELATIVELY MINOR SINCE THE HEAVIER SNOW
RATES WILL BE QUITE BRIEF IN DURATION... WITH SOME MELTING LIKELY
IN BETWEEN SNOW SHOW SHOWERS IN PEEKS OF LATE MARCH SUN.
ISSUED A SPECIAL WEATHER STATEMENT EARLIER TALKING ABOUT THE
HAZARD/IMPACT RELATED TO DRIVING INTO THESE POTENTIALLY SUDDENLY
BLINDING SNOW SQUALLS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 322 AM EDT TUE MAR 25 2014
THE FIRST ORDER OF BUSINESS IN THE SHORT TERM PORTION OF THIS FCST
PACKAGE IS DEALING WITH THE ONGOING BAND OF SNOW MOVING THROUGH THIS
MORNING. WE WILL THEN HAVE TO IDENTIFY TRENDS WITH REGARDS TO LAKE
EFFECT THROUGH WED...BEFORE TURNING OUR ATTENTION TO THE NEXT SYSTEM
FOR WED NIGHT AND THU.
WE ARE SEEING THE NICE...YET SHORT BURST OF SNOW MOVING THROUGH THE
CWFA EARLY THIS MORNING ALMOST AS EXPECTED. THE ONE THING THAT IS A
LITTLE DIFFERENT THAN EXPECTED IS THE EAST/WEST BAND OF SNOW THAT IS
IN PLACE JUST NORTH OF THE CWFA ALONG M-55. THIS IS JUST A LITTLE
FURTHER NORTH THAN EXPECTED...WHICH SHOULD HELP CUT BACK ON SNOW
ACCUMS A LITTLE ACROSS THE NORTH.
OTHERWISE...THE BAND OF SNOW MOVING THROUGH SRN LOWER MICHIGAN IS
PROGRESSING TO THE EAST NICELY THIS MORNING. IT IS QUICK ENOUGH THAT
ACCUMULATIONS WILL BE LIMITED TO AN INCH OR SO...ALTHOUGH IT WILL
HAPPEN IN A SHORT PERIOD OF TIME. WE CONTINUE TO EXPECT THIS WILL
EXIT THE CWFA TO THE SE AROUND 12Z PER THE LATEST EXTRAPOLATION OF
THE BACK OF THE LINE. THE SHORT DURATION AND THE CORE OF THE SNOW
FALLING BEFORE THE MORNING COMMUTE CONTINUES TO JUSTIFY HOLDING OFF
ON AN ADVISORY AT THIS TIME.
WE EXPECT TO SEE A SHORT BREAK OF THE SNOW SHOWERS IN THE WAKE OF
THE LINE WITH THE COLD FRONT THIS MORNING. WE DO EXPECT SCATTERED TO
NUMEROUS SNOW SHOWERS TO DEVELOP BY MID-LATE MORNING WITH THE
ARRIVAL OF THE SUPPORTING UPPER TROUGH EXPECTED TO MOVE THROUGH
EARLY THIS AFTERNOON. THE TROUGH...COMBINED WITH DIURNAL
INSTABILITY...AND SOME CONTRIBUTION OF HEAT/MOISTURE FROM LAKE
MICHIGAN WILL JUSTIFY THE RELATIVELY HIGHER CHCS OF SNOW SHOWERS.
THE STRONG LATE MARCH SUN WILL LIMIT ANY ACCUMS...ALTHOUGH A QUICK
COVERING OF THE GROUND COULD OCCUR DUE TO THE CONVECTIVE NATURE OF
THE SNOW SHOWERS EXPECTED.
SNOW SHOWERS WILL START DIMINISHING DURING THE SECOND HALF OF THE
AFTERNOON AS THE UPPER TROUGH AXIS SHIFTS EAST OF THE AREA. WE
EXPECT THEM TO DIMINISH AT INLAND LOCATIONS...AND FOR THEM TO
MIGRATE CLOSER TO THE LAKE. THEY SHOULD GRADUALLY DIMINISH
ALTOGETHER BY WED MORNING AS HIGH PRESSURE MOVES DIRECTLY OVERHEAD.
WE DO EXPECT SKIES TO GO AT LEAST PARTLY CLOUDY IF NOT CLEAR
OVERNIGHT. THIS WILL ALLOW FOR A COLD NIGHT...ESPECIALLY INLAND.
THIS SHOULD CONTINUE INTO WED AS THE FLOW ALOFT BECOMES
ANTI-CYCLONIC.
WE WILL SEE PCPN CHCS INCREASE ONCE AGAIN DURING THE NIGHT TIME
HOURS ON WED NIGHT....ESPECIALLY ACROSS THE NW PORTION OF THE CWFA.
RETURN FLOW WILL SET UP ON THE BACKSIDE OF THE HIGH AT THE SFC...AND
GRADUALLY A DEEP SW FLOW ALOFT WILL SET UP OVER THE AREA BY THU
MORNING AS THE UPPER RIDGE AXIS SHIFTS EAST. SOME DECENT MOISTURE
TRANSPORT WILL TAKE PLACE...ALLOWING PCPN TO DEVELOP. THE PCPN WOULD
START OUT AS MAINLY SNOW. A WARM NOSE ALOFT TRIES TO PUSH IN
OVERNIGHT WHICH WOULD SUPPORT A LOW CHC OF SOME FREEZING RAIN. WE
WET BULB DOWN PRETTY WELL...AND P-TYPE BECOMES A MAINLY RAIN OR SNOW
SCENARIO BY THU MORNING WITH NEARLY AN ISOTHERMAL PROFILE DEVELOPING
BY 12Z THU. IT WILL CONTINUE TO WARM THU MORNING...AND ALL PCPN
SHOULD TURN TO RAIN BY 18Z THU. A BETTER THREAT OF PCPN/RAIN WILL
COME THU AFTERNOON /AND BEYOND/ AS THE NOSE OF THE LLJ/MOISTURE
TRANSPORT MOVES UP INTO THE AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 322 AM EDT TUE MAR 25 2014
BETTER CONFIDENCE ON SOME RAIN FOR THURSDAY NIGHT. MODELS CONTINUE
TO SHOW LOW PRESSURE TRACKING THROUGH LOWER MICHIGAN THURSDAY
NIGHT. THIS SYSTEM WILL CONTAIN GULF MOISTURE. THE NOSE OF THE 850
MB LOW LEVEL JET IS FORECASTED TO PUSH THROUGH THE REGION THU
EVENING. SO RAIN IS EXPECTED THU NIGHT...ESPECIALLY EARLY. POPS
WERE INCREASED. WHILE SOME OF THE RAIN COULD BE HEAVY....IT
APPEARS THAT SINCE THE LOW LEVEL JET STEADILY PUSHES THROUGH...THAT
THE DURATION OF ANY HEAVY RAIN WILL BE LIMITED. STILL WITH SNOW
MELT...ESPECIALLY NORTH OF GRAND RAPIDS...WE WILL NEED TO MONITOR
THE POTENTIAL FOR HYDRO IMPACTS. I DID TREND THE FORECAST MORE
TOWARDS RAIN FOR THU NIGHT. THE COLDER AIR ON THE HIGH RES EURO
ARRIVES AFTER 12Z FOR NORTHWEST COUNTIES. THE COLDER GFS SOUNDINGS
DO NOT SUPPORT SNOW GIVEN UNSATURATED DGZ ASSOCIATED WITH THE DRY
SLOT AFTER 06Z FRI.
WE WILL HAVE TO MONITOR THE NEXT WAVE OF LOW PRESSURE RIDING UP THE
OH VALLEY SAT. THIS WOULD BE A SNOW SYSTEM IF IT DID REACH SW LOWER
MI. LOOKS LIKE THE TRACK IS TOO FAR SOUTH AND EAST TO IMPACT THE
REGION.
IMPRESSIVE WARM AIR ADVECTION DEVELOPS SUNDAY NIGHT INTO MONDAY.
THIS SYSTEM WILL BE TAPPING GULF MOISTURE. OVERALL I BUMPED UP
TEMPS AND POPS OVER GUIDANCE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 118 PM EDT TUE MAR 25 2014
SCATTERED SNOW SHOWERS DOTTED THE LANDSCAPE EARLY THIS AFTERNOON.
BECAUSE OF THIS CONDITIONS WERE HIGHLY VARIABLE ACROSS THE REGION.
OUTSIDE OF THE SNOW SHOWERS VFR WEATHER CAN BE EXPECTED...BUT
WITHIN THE SNOW SHOWERS IFR OR EVEN BRIEFLY LIFR CAN BE EXPECTED.
THESE SHOWERS WERE LARGELY DIURNALLY DRIVEN AND WILL FALL APART
TOWARD EVENING...SO EXPECT MOST OF THE IFR WILL EXIT THE AREA
AROUND 01Z. HOWEVER MVFR CEILINGS SHOULD PERSIST OVERNIGHT...
IMPROVING TO VFR WED MORNING.
NW WINDS WILL REMAIN BRISK...GUSTING TO 20 TO 25 KNOTS...BUT THESE
WINDS WILL DROP OFF AROUND SUNSET AND REMAIN LIGHT INTO WED.
&&
.HYDROLOGY...
ISSUED AT 330 PM EDT MON MAR 24 2014
HAVE CANCELLED THE FLOOD WARNING FOR THE MAPLE RIVER AT MAPLE
RAPIDS. CURRENTLY 11 FLOOD ADVISORIES REMAIN. LIMITED SNOW MELT AND
LIMITED ADDITIONAL PRECIPITATION SHOULD ALLOW STEADY OR FALLING
LEVELS ACROSS THE AREA THROUGH WEDNESDAY.
CONFIDENCE IS GROWING THAT A SIGNIFICANT SHIFT TO MUCH WARMER AND
WETTER CONDITIONS WILL COMMENCE THURSDAY AND LAST WELL INTO NEXT
WEEK. SOME LONG RANGE COMPUTER MODELS PREDICT THAT LONG TERM
PRECIPITATION TOTALS OF A COUPLE INCHES OR MORE ARE POSSIBLE BY THE
END OF NEXT WORK WEEK. AT THE SAME TIME...HIGH TEMPERATURES NEXT
WORK WEEK COULD REMAIN WELL IN THE 50S.
FOR AREAS ALONG AND NORTH OF THE MUSKEGON RIVER BASIN...SNOW PACK IS
SIGNIFICANTLY GREATER WITH SNOW WATER EQUIVALENT OF 3 INCHES OR MORE
OVER A LARGE AREA. THIS COMBINED WITH THE EXPECTED CHANGE IN THE
WEATHER WOULD MEAN SIGNIFICANT RISES TO AREA RIVERS. THIS COULD BE
EXACERBATED FURTHER IF ICE JAMS DEVELOP. THE COOPERATIVE OBSERVER IN
SCOTTVILLE REPORTED THAT THE PERE MARQUETTE RIVER HAS ALREADY BEEN
OPEN SINCE LAST WEEK. HOWEVER...ICE WAS STILL PRESENT FARTHER
NORTH NEAR LUDINGTON AND IN PERE MARQUETTE LAKE. WE ARE WAITING TO
HEAR BACK FROM OTHER OBSERVERS ABOUT THE EXTENT OF ICE COVERAGE ON
THE MUSKEGON AND CHIPPEWA RIVERS.
FOR THE GRAND AND KALAMAZOO RIVER BASINS...THERE IS FAR LESS
SNOWPACK AND RIVERS ARE ESSENTIALLY ICE FREE. HOWEVER...IT IS
POSSIBLE THAT SIGNIFICANTLY MORE RAIN COULD FALL OVER THIS AREA WITH
THE PATTERN CHANGE...SO ALL RIVERS ACROSS SOUTHWEST LOWER MICHIGAN
WILL NEED TO BE MONITORED CLOSELY OVER THE NEXT SEVERAL DAYS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...MEADE
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...MJS
AVIATION...JK
HYDROLOGY...TJT
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
125 PM EDT TUE MAR 25 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS EAST THROUGH THE OHIO VALLEY
TODAY. A LARGE AREA OF HIGH PRESSURE WILL BUILD WEST OF THE AREA
TONIGHT AND CROSS THE OHIO VALLEY ON WEDNESDAY. THE NEXT COLD
FRONT TO CROSS THE REGION WILL SEE RAIN AND MILD TEMPERATURES
OVERSPREAD THE OHIO VALLEY BEFORE IT PASSES ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COLD FRONT CURRENTLY PUSHING INTO NORTHWEST INDIANA WILL WORK
EAST ACROSS OUR AREA THROUGH THIS AFTERNOON. WE ARE ALREADY SEEING
FAIRLY WIDESPREAD SNOW SHOWER ACTIVITY ASSOCIATED WITH THIS BACK
ACROSS INDIANA. AS DAYTIME HEATING DEVELOPS...LOW LEVEL LAPSE RATES
WILL CONTINUE TO INCREASE THROUGH LATE MORNING/EARLY AFTERNOON.
THE 06Z NAM AND LATEST RAP RUNS ARE ALSO INDICATING A NARROW AXIS
OF WEAK ELEVATED INSTABILITIES PROGRESSING EAST ACROSS OUR AREA
THROUGH THIS AFTERNOON. THUS...EXPECT CONVECTIVE SNOW SHOWER
ACTIVITY TO BECOME EVEN MORE WIDESPREAD THROUGH LATE MORNING AND
INTO THIS AFTERNOON. THINK ALL AREAS WILL AT LEAST SEE SOME PCPN SO
WILL GO AHEAD AND BUMP UP POPS TO CATEGORICAL. WOULD EXPECT THE
POSSIBILITY FOR VISIBILITIES TO BRIEFLY DROP DOWN BELOW A QUARTER
OF A MILE IN THE HEAVIER SNOW SHOWERS. SOME QUICK DUSTING TO HALF
INCH ACCUMULATIONS WILL BE POSSIBLE WITH THESE HEAVIER SNOW
SHOWERS...PRIMARILY ON GRASSY AREAS AND ELEVATED SURFACES. ROAD
TEMPERATURES ARE CURRENTLY A FEW DEGREES ABOVE FREEZING ACROSS THE
AREA...SO WOULD EXPECT THE PRIMARY TRAVEL CONCERN TO BE THE LOWER
VISIBILITIES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
DROPPED LOW TEMPERATURES TONIGHT BY A FEW DEGREES WITH THE HIGH
BUILDING IN RAPIDLY FROM THE WEST AND A STRONG COLD PUSH. AM NOT
EXPECTING A LOT OF FRESH SNOW COVER OTHERWISE I WOULD HAVE CUT
LOWS EVEN FURTHER. MID TO UPPER TEENS SHOULD BE A FAIRLY UNIFORM
MIN TEMPERATURE TONIGHT OVER MUCH OF THE REGION AS SKIES CLEAR.
NORTH FLOW ON WEDNESDAY WILL COMPETE WITH SOME INCREASING HIGH
CLOUDS IN THE LATTER PART OF THE DAY AS THE AXIS OF HIGH PRESSURE
CROSSES THE REGION. FLOW WILL TURN SOUTH WEDNESDAY NIGHT AND
TEMPERATURES WILL THEN SEE A MARKED INCREASE FOR THE NEXT SEVERAL
PERIODS. MOISTURE WILL ALSO BE ON THE INCREASE THROUGH THURSDAY
AHEAD OF THE NEXT FROPA ON FRIDAY.
AS THE MOISTURE PULLS INTO THE REGION THURSDAY...THE THREAT FOR
SOME SHOWERS WILL INCREASE LATE IN THE DAY AND PARTICULARLY
OVERNIGHT IN NORTHWESTERN CWA...SPREADING EAST AS THE FRONT
APPROACHES. HAVE RAMPED UP THE POPS OVERNIGHT AS A STRONG LLJET
OF 50-60KT STREAMS GULF MOISTURE INTO THE REGION.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
WILL RAMP UP POPS TO LKLY WITH EXPECTED FROPA FRIDAY AFTN. WILL
MENTION A CHANCE OF THUNDER WITH MARGINAL INSTBY INDICATED AHD OF
THIS FRONT.
IN RETURN SOUTHERLY FLOW TEMPERATURES TO BE CLOSE TO NORMAL
THURSDAY...WITH HIGHS RANGING FROM THE LOWER 50S NW TO THE UPPER 50S
SE. ON THE WARM SIDE OF THIS SYSTEM...HIGHS ON FRIDAY TO RANGE FROM
THE MID 50S NW TO THE LOWER 60S SE.
MODEL DIFFERENCES EXISTS REGARDING THE DEVELOPMENT OF A SRN SECONDARY
SFC WAVE. ECMWF/CMC ARE MORE PROGRESSIVE WITH GFS DEVELOPING THIS
WAVE. WILL TREND FCST TOWARD MORE PROGRESSIVE SOLN AND ONLY LINGER A
CHANCE OF SHOWERS INTO FRIDAY EVENING WITH THE UPPER TROF LAGGING
ACRS THE REGION.
SFC HIGH PRESSURE TO BUILD ACRS THE REGION PROVIDING DRY WEATHER
CONDITIONS AND COOLER TEMPERATURES. SATURDAYS HIGH TEMPERATURES TO
RANGE FROM UPPER 40S NORTHWEST TO THE MID 50S SOUTHEAST.
THIS HIGH TO QUICKLY SLIDE OFF TO THE EAST WITH A RETURN FLOW
DEVELOPING. TEMPERATURES TO WARM UP ABOVE NORMAL...WITH HIGHS FROM
THE UPPER 50S NORTHEAST TO THE LOWER 60S SOUTHWEST.
A FEW WAA SHOWERS WILL BE POSSIBLE NEXT MONDAY ESPECIALLY ACRS THE
NORTHWEST. HAVE LIMITED MENTION TO SLIGHT CHANCE CATEGORY AT THIS
TIME. TEMPERATURES TO CONTINUE TO WARM UP WITH HIGHS ON MONDAY FROM
THE MID 60S NW TO AROUND 70 SE.
&&
.AVIATION /17Z TUESDAY THROUGH SATURDAY/...
A COLD FRONT IS PUSHING EAST ACROSS OUR AREA EARLY THIS
AFTERNOON. CONVECTIVE SNOW SHOWERS ALONG AND JUST BEHIND THIS
FRONT WILL WORK THEIR WAY EAST ACROSS THE TAF SITES THROUGH MID TO
LATE AFTERNOON. VISIBILITIES WITHIN THESE SNOW SHOWERS MAY BRIEFLY
DROP TO BELOW A QUARTER OF A MILE ALONG WITH SOME IFR CIGS. AS THE
FRONT PASSES...WINDS WILL BECOME NORTHWESTERLY WITH GUSTS IN THE
25 TO 30 KNOT RANGE POSSIBLE THROUGH LATE AFTERNOON. HIGH PRESSURE
AND A DRIER AIRMASS WILL BEGIN TO BUILD IN TONIGHT THROUGH
WEDNESDAY...RESULTING IN IMPROVING CONDITIONS THROUGH THE
REMAINDER OF THE TAF PERIOD.
OUTLOOK...MVFR CEILINGS AND VISIBILITIES LIKELY LATE THURSDAY
NIGHT INTO FRIDAY ALONG WITH A CHANCE OF THUNDERSTORMS.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...JGL
SHORT TERM...FRANKS
LONG TERM...AR
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
340 PM CDT TUE MAR 25 2014
.SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...SURFACE HIGH
PRESSURE WILL BE EAST OF THE REGION...OVER THE OZARKS BY THIS
EVENING. LOW LEVEL EASTERLY FLOW WILL BECOME ESTABLISHED AS A
RESULT AND MOISTURE WILL BEGIN TO INCREASE WITH PW VALUES AROUND
1.4 INCHES BY 12Z WEDNESDAY. UPPER DISTURBANCE CURRENTLY OVER THE
CA/AZ BORDER WILL MOVE EASTWARD TONIGHT AND INTO TEXAS ON
WEDNESDAY. UPPER TROUGH COMBINED WITH JET OVER THE AREA WILL LEAD
TO INCREASED CHANCES OF SHOWERS AND THUNDERSTORMS BEGINNING
TONIGHT AND CONTINUING INTO WEDNESDAY. POPS WILL INCREASE FIRST
OVER THE RIO GRANDE PLAINS LATER THIS EVENING AND SPREAD EASTWARD
TONIGHT. THIS IS SUPPORTED BY THE LATEST RUNS OF THE HRRR AS
SHOWERS MOVE OUT OF MEXICO. GREATER CHANCES FOR RAIN WILL THEN
SHIFT TO THE EAST/NORTHEAST PARTS (60 TO 70 POPS) OF THE REGION ON
WEDNESDAY AS UPPER TROUGH SWINGS THROUGH. CLOUD COVER AND
INCREASED RAIN CHANCES WILL KEEP TEMPS MOSTLY IN THE 60S ON
WEDNESDAY...WITH A FEW 70S FROM THE RIO GRANDE PLAINS TO EXTREME
SOUTHERN COASTAL BEND. RAIN CHANCES WILL PERSIST INTO WEDNESDAY
NIGHT AS SUFFICIENT MOISTURE REMAINS OVER THE REGION. MUCH WARMER
OVERNIGHT LOWS IN THE 60S CAN BE EXPECTED DUE TO THE MOSTLY CLOUDY
TO OVERCAST SKIES.
&&
.MARINE...STRONG ONSHORE FLOW WILL DEVELOP TONIGHT OVER THE GULF
WATERS...WITH SEAS BEGINNING TO BUILD AS WELL. WINDS WILL INCREASE
BETWEEN 20 AND 25 KNOTS OVER THE NEARSHORE WATERS...AND AROUND 25
KNOTS OVER THE OFFSHORE WATERS ON WEDNESDAY. SEAS WILL RANGE FROM
7 TO 9 FEET OVER THE NEARSHORE WATERS WITH 8 TO 10 FEET OVER THE
OFFSHORE WATERS. SMALL CRAFT ADVISORY CONDITIONS WILL PERSIST INTO
THURSDAY AS WINDS AND SEAS WILL BE SLOW TO DIMINISH.
&&
.LONG TERM (THURSDAY THROUGH MONDAY)...MAIN ACTIVITY IN LONG TERM IS
IN THE FIRST PERIODS WITH LINGERING MOISTURE IN NORTHEAST ZONES ON
THURSDAY. UPPER LEVEL JET REMAINS OVER THE REGION...THOUGH GFS HAS
WEAKENED IT QUITE A BIT. NAM SHOWS BEST UPPER LEVEL DIVERGENCE...AND
ALSO SHOWS STRONGER SHORT WAVE PUSHING THROUGH THE REGION ON
THURSDAY. MAIN CONCERN FOR PRECIP IS TIMING OF ALL THE INGREDIENTS.
BEST CAPE IS LATE AFTERNOON...BUT INDICATIONS ARE THAT MOISTURE
SHOULD BE MOVING OUT QUICKLY IN THE LATE AFTERNOON. HAVE KEPT A MAX
40 POP IN FAR NORTHEAST ZONES. IF STORMS DO DEVELOP COULD SEE SOME
STRONG STORMS WITH SUFFICIENT UPPER LEVEL SUPPORT AND GOOD CAPE.
BEYOND THAT...FORECAST GETS PRETTY QUIET. HAVE DRY LINE MOVING INTO
AREA THURSDAY...AND AGAIN ON FRIDAY WITH TEMPERATURES WEST OF IT
INTO THE UPPER 80S AND LOWER 90S. EAST IS A BIT COOLER. GFS STARTING
TO INDICATE PRECIP POTENTIAL FOR FRIDAY AFTERNOON...BUT NOT SOLD ON
THE MOISTURE RETURN THAT QUICKLY. HAVE KEPT JUST A SILENT 10 POP FOR
NOW...BUT IF THIS REMAINS CONSISTENT...AND IS INDICATED IN OTHER
MODELS MAY NEED TO ADD SLIGHT CHANCE POPS DOWN THE ROAD. COLD FRONT
PUSHES THROUGH FRIDAY NIGHT TO EARLY SATURDAY MORNING...BUT LOOKS
QUITE WEAK. NOT EXPECTING ANY PRECIP ASSOCIATED WITH IT...AND
TEMPERATURES WONT COOL MUCH. GRADUAL INCREASE IN MOISTURE IS
EXPECTED BY EARLY NEXT WEEK...BUT NO MENTIONABLE POPS AT THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 58 69 67 81 67 / 20 60 30 20 10
VICTORIA 52 65 63 79 65 / 10 70 40 40 10
LAREDO 59 73 68 92 69 / 40 30 20 10 10
ALICE 56 70 65 87 66 / 30 50 30 20 10
ROCKPORT 60 69 67 70 68 / 20 60 30 20 10
COTULLA 56 69 64 87 64 / 30 40 20 10 10
KINGSVILLE 58 70 66 84 67 / 30 50 30 20 10
NAVY CORPUS 61 70 67 76 67 / 20 60 30 20 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FROM 1 AM WEDNESDAY TO 7 AM CDT THURSDAY
FOR THE FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO
PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS
TO MATAGORDA SHIP CHANNEL OUT 20 NM.
SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 AM CDT THURSDAY
FOR THE FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT
ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO
MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM.
&&
$$
TB/78...SHORT TERM
PZ/83...LONG TERM
AREA FORECAST DISCUSSION...UPDATED
NWS PORTLAND OR
255 PM PDT TUE MAR 25 2013
UPDATED TO INCLUDE WIND ADVISORY HAZARDS
.SYNOPSIS...A DEEP UPPER LEVEL LOW OFFSHORE WILL PUSH A SECONDARY
FRONT THROUGH TODAY. THIS WILL BRING A ROUND OF SHOWERS WITH EVEN
SOME ISOLATED THUNDERSTORMS. SNOW LEVELS LOWER TO THE CASCADE PASSES
AND BELOW TONIGHT. COOL UNSETTLED WEATHER WILL CONTINUE THROUGH
THURSDAY AS THE UPPER LOW LINGERS NEARBY. A MORE ORGANIZED PACIFIC
FRONTAL SYSTEM IS EXPECTED BY THURSDAY NIGHT OR FRIDAY...LIKELY
BRINGING PERIODS OF HEAVIER RAIN INTO THE WEEKEND.
&&
.SHORT TERM...TONIGHT THROUGH FRIDAY...
A FEW LIGHTNING STRIKES FROM CAPE BLANCO TO NORTH BEND...TRACKING
NICELY ALONG A DRY PUNCH IN WATER VAPOR SATELLITE IMAGERY HAVE SPREAD
INLAND WHERE THUNDER HAS BEEN REPORTED/OBSERVED VIA LIGHTNING
NETWORKS IN THE CENTRAL/SOUTH VALLEY AND INTO THE FOOTHILLS. THIS
AXIS LINES UP WITH ABOUT 100 J/KG MOST UNSTABLE CAPE FROM THE
RAP...AND THIS AREA CURRENTLY EXTENDS INLAND THROUGH WILLAMETTE
VALLEY. EXPECT ACTIVITY TO SHIFT NORTH WHERE SUNBREAKS ALLOWED FOR
ADDITIONAL HEATING AND THESE AREAS REMAIN NORTH OF THE OCCLUDED
FRONTAL BOUNDARY. EXPECT ACTIVITY TO EASE THIS EVENING BEHIND THE
FRONT. ALONG THE COLD/OCCLUDED FRONT TEMPS ARE DROPPING BACK INTO
THE 40S/LOW 50S WITH A WIND SHIFT TO WSW AND SOME STABILIZATION. IT
WILL REMAIN BREEZY IN THE VALLEY THIS AFTERNOON WITH GUSTS EVEN TO
40 MPH DUE TO GOOD LOW LEVEL MIXING AND A STRONG LOW LEVEL WIND
FIELD...WITH PEAK WIND GUSTS TO 45-50 MPH AT THE COAST. SOME OF
THESE WINDS WILL BE ENHANCED BY CONVECTIVE DOWNDRAFTS SUCH THAT
SMALL BRANCHES/LIMBS MAY COME DOWN. THE UPPER WAVE AND ASSOCIATED
SURFACE LOW OFF THE WA COAST WILL CONTINUE TO PASS OFF TO THE NORTH
AND WILL EASE THE WINDS THIS EVENING AND SHOWER ACTIVITY TONIGHT.
SNOW ACCUMULATIONS ARE NOT EXPECTED AT THE PASSES UNTIL THIS EVENING
OR TONIGHT ONCE THE AFOREMENTIONED OCCLUDED/COLD FRONT PUSHES
THROUGH...POSSIBLY BRINGING A FEW INCHES BY DAYBREAK WEDNESDAY WITH
THE SNOW LEVEL DROPPING TO OR BELOW THE PASSES. QPF IS NOT ALL THAT
IMPRESSIVE...AND OROGRAPHICS ARE WEAK...SO JUST EXPECT 2-4 INCHES OF
SNOW AT MOST TONIGHT...WITH THE HIGHER ACCUMULATIONS ABOVE THE
PASSES. THIS WILL BE THE TREND WITH EACH SUBSEQUENT SHOWERY SYSTEM IN
THE SHORT TERM...A FEW INCHES OF ACCUMULATION AT A TIME THROUGH
THURSDAY...WITH MAYBE 6-12 INCHES FOR THE HIGHER CASCADE ELEVATIONS
THROUGH THIS TIME.
EXPECT MAYBE BIT OF LULL IN PRECIPITATION LATER THIS EVENING INTO THE
EARLY MORNING HOURS...BUT LOOKING UPSTREAM THERE ARE QUITE A BIT OF
SHOWER ACTIVITY OUT OVER THE PACIFIC. ANOTHER SHORT WAVE TROUGH
ROUNDING THE BASE OF THE CLOSED OFFSHORE LOW APPROACHES LATE TONIGHT
INTO WEDNESDAY MORNING...FOLLOWED BY THE CORE OF THE PARENT UPPER LOW
ON WEDNESDAY EVENING INTO EARLY THURSDAY. THERE IS ANOTHER SURFACE
LOW THAT WILL BE WEAKENING AS IT APPROACHES THE COAST WHICH WILL
BRING SOME BREEZES BUT NOT AS WINDY AS TODAY.
WHILE THERE IS A PERIOD OF UPPER RIDGING BEHIND THE UPPER
LOW...ANOTHER UPPER LOW WILL QUICKLY TAKE THE PLACE OF THE PREVIOUS
ONE. MOIST SW LOW LEVEL WARM ADVECTION AHEAD OF THIS LOW KEEPS LIFT
OVER THE AREA AHEAD OF A WARM FRONTAL FEATURE THURSDAY NIGHT...THEN A
TRAILING COLD FRONTAL BOUNDARY FRIDAY. THIS SYSTEM LOOKS PRETTY
WET...AND WITH SOME AMPLIFICATION OF THE UPPER FLOW...THE BOUNDARY GETS
HUNG UP A BIT INTO FRIDAY NIGHT AS ADDITIONAL WAVES IN SOUTHWEST FLOW
TRACK TOWARD THE AREA. THIS SYSTEM HAD ITS ORIGINS IN THE FAR WEST
PACIFIC ABOUT A WEEK AGO PICKING UP SOME SUBTROPICAL MOISTURE IT
LOOKS LIKE IT IS CARRY THAT EAST IN AN ORGANIZING ATMOSPHERIC RIVER
OF MOISTURE AS ITS NOSE APPROACHES 160W...SOMETHING THAT WILL HAVE
TO WATCHED FOR LATER IN THE WEEK. SOME RIVERS ARE FORECAST TO GET TO
BANKFULL AT THIS TIME...ALOT CONTINGENT ON RAINS RECEIVED IN SHOWERS
BEFOREHAND. EVENTUALLY SOME OF THE ENERGY SPLITS OFF TO THE
SOUTH...SEEN ON BOTH THE GFS/ECMWF...TO ALLOW THE BAROCLINIC ZONE TO
DRIFT SOUTHWARD TO MITIGATE ANY ADDITIONAL CONCERNS. /KMD
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...
EXPECT LITTLE CHANGE IN THE OVERALL WEATHER PATTERN OVER THE EXTENDED
FCST PERIOD. A SERIES OF UPPER LEVEL TROUGHS WILL KEEP COOL AND WET
WEATHER CONTINUING THROUGH THE WEEKEND AND THE FIRST HALF OF NEXT
WEEK. A SIGNIFICANT SYSTEM LOOKS LIKE IT WILL BRING MODERATE
PRECIPITATION TO THE REGION FRI NIGHT...BUT THE LATEST MODEL CYCLE
CONTINUES TO KEEP THE HEAVIEST QPF FOCUSED OVER N CALIFORNIA AND S
OREGON. AFTER THIS FRONT PUSHES THROUGH...DO NOT CURRENTLY SEE ANY
MAJOR SYSTEMS THROUGH EARLY NEXT WEEK. BUT THERE WILL PLENTY OF
CHANCES FOR LIGHT RAIN AND MOUNTAIN SNOW. EXPECT TEMPERATURES TO RUN
ABOUT 5 TO 7 DEGREES BELOW NORMAL OVER THE LONG TERM PERIOD. PYLE
&&
.AVIATION...FLIGHT CONDITIONS REMAIN GENERALLY VFR AS OF
21Z ACROSS THE REGION AS THE COLD FRONT CONTINUES TO PUSH INLAND.
EXPECT PRIMARILY VFR CONDITIONS THROUGH WED...THOUGH MVFR LIKELY
IN ANY HEAVIER SHOWERS TONIGHT. ALSO CANNOT RULE OUT SOME
THUNDERSTORMS THROUGH THIS EVENING...THOUGH SHOULD REMAIN
ISOLATED. S WINDS REMAIN GUSTY BOTH ACROSS THE COASTAL AREAS AND
INLAND...WITH GUSTS 30-40 KT THROUGHOUT THE AREA THIS AFTERNOON.
THESE WILL CONTINUE THROUGH THIS EVENING BEFORE EASING TONIGHT.
WINDS AND LOWER FLIGHT CONDITIONS LIKELY TO LAST A BIT LONGER AT
THE COAST...ESPECIALLY AROUND KONP. LINGERING SHOWERS WILL REMAIN
TONIGHT THROUGH WED.
KPDX AND APPROACHES...EXPECT GENERALLY VFR TO PREVAIL THIS
EVENING...THOUGH MVFR CONDITIONS LIKELY UNDER ANY HEAVIER RAIN
SHOWERS. SOME ISOLATED THUNDERSTORMS POSSIBLE THROUGH THE
EVENING...THOUGH NOT ENOUGH CONFIDENCE TO INCLUDE IN TAF. EXPECT
CONTINUED SHOWERS UNDER VFR THROUGH WED. CULLEN
&&
.MARINE...THE COLD FRONT CONTINUES TO PUSH ITS WAY INLAND WITH
GUSTY WINDS ACROSS THE WATERS. THE AIR MASS REMAINS UNSTABLE
BEHIND THE FRONT AND IT IS POSSIBLE TO SEE SOME THUNDERSTORMS
DEVELOP THROUGH THE EARLY EVENING HOURS OVER THE WATERS. S WINDS
HAVE GUSTED TO NEAR 40 KT AT BUOY 29 MUCH OF THE DAY...AND WINDS
CONTINUE TO GUST NEAR GALE STRENGTH ACROSS BUOY 50. WINDS WILL
REMAIN STRONG THROUGH THE EVENING...BEFORE TURNING SW AND
BEGINNING TO EASE SLIGHTLY. HOWEVER...EXPECT GUSTS TO DECREASE TO
20-25 KT BY EARLY WED MORNING. HOWEVER...A SERIES OF DISTURBANCES
WILL MOVE ACROSS THE WATERS TO BRING PERIODS OF SMALL CRAFT
ADVISORY WINDS THROUGH THE END OF THE WEEK.
SEAS ARE CURRENTLY 11 TO 13 FT ACROSS THE WATERS. GIVEN
OBSERVATIONS FURTHER OFFSHORE...STILL THINK A PEAK NEAR 14 FT
LATER TODAY IS REASONABLE TO EXPECT. SEAS WILL SLOWLY BUT SLIGHTLY
SUBSIDE BACK TO NEAR 10 FT BY TOMORROW AFTERNOON. A BRIEF DROP TO
9 FT IS POSSIBLE...BUT SEAS WILL REBUILD TO NEAR 11 FT BY WED
NIGHT AS THE NEXT SWELL ARRIVES. EXPECT SEAS TO REMAIN IN THE 9 TO
12 FT RANGE THROUGH THE END OF THE WEEK. CULLEN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY FOR THE CENTRAL AND NORTH WILLAMETTE VALLEY AND PORTLAND
METRO AREA UNTIL 7 PM PDT.
WA...WIND ADVISORY FOR CLARK COUNTY AND THE VANCOUVER METRO AREA UNTIL 7 PM
PDT.
PZ...GALE WARNING UNTIL 9 PM PDT THIS EVENING FOR COASTAL WATERS
FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 3 PM
PDT WEDNESDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA..
[top]
Area Forecast Discussion
National Weather Service Spokane WA
240 PM PDT TUE MAR 25 2014
.SYNOPSIS...A showery and unsettled spring time weather pattern
will persist through Thursday. The unsettled weather will bring a
chance for thunderstorms beginning this afternoon and evening and
repeating on Wednesday and Thursday. Temperatures will remain
above normal today and cool to near normal or slightly below
through the rest of the week. Friday into the weekend a warm wet
weather system is expected to bring widespread rain and high
mountain snow to the region.
&&
.DISCUSSION...
Tonight and Wednesday: Low pressure in the Gulf of
Alaska will push through an occluded front late this afternoon
through this evening. The back edge of this front is currently
beginning to push into the Cascade Mtns at 2:00 PM this afternoon.
There has been very little in the way of shower development east
of the Cascade Mtns ahead of the front. Radar returns have been
weak and cloud ceilings have generally been above 6-9 kft agl.
With dew point temps still in the mid 20s across much of the
region, there is still some moistening up that needs to be done
before we see any appreciable precip reaching the surface. I
scaled back the chances for precip across much of the region.
Models are still showing some shallow instability across southeast
WA and into the Central Panhandle Mtns. This will be our best bet
for showers to develop later today into this evening with the
front. This instability looks to be too weak for thunderstorms and
have been removed from the forecast. The only area where we might
see some thunderstorms this afternoon and evening will be along
the Cascade crest as the upper level cold pool shifts over head
and produces some deeper instability; however, my confidence for
thunderstorms here is also low. The HRRR model seems to have a
good handle on this system and it does show some isolated to
scattered showers developing behind the front into this evening.
Showers are expected to mainly be limited to the mountains as we
go through the overnight hours.
The upper level cold pool will be better positioned over the
region on Wednesday. This will allow for some afternoon showers to
redevelop over much of the region. There will be a marginal chance
for thunderstorms over the Northeast Mtns, into the ID Panhandle
and in the Northeast Blue Mtns. Instability parameters are not
very exciting with surface based CAPE values of 150 J/KG off the
GFS and 50-100 J/KG or so off of the NAM. I went ahead and left a
slight chance for thunderstorms, but a lack of dynamics will make
it difficult to get much in the way of deep convection going. Temps
on Wednesday will be right around normal for late March with highs in
the 50s for most valley locations. /SVH
Wednesday night through Friday...A closed low in the Gulf of
Alaska will begin to move inland Wednesday night and open up into
a wave on Thursday as it passes through the region. This will be
followed by building high pressure over the region Thursday night
and Friday. As such we expect showery precipitation Thursday and
widespread stratiform precipitation Friday.
Wednesday night and Thursday..As mentioned above the closed low
will move through the region...weaken...and open into a wave on
Thursday. This will increase the forcing for Thursday afternoon.
The atmosphere will remain conditionally unstable. 5h
temperatures are only -26 to -28C...but lapse rates increase to
7.0C to 8.0C by the afternoon. Lastly surface based capes are on
the order of 100-200 J/kg. There will be plenty of low and mid-
level moisture to work with. All this means a good chance of
showers any where out side of the basin with a slight chance of
late day thunderstorms..mainly across the eastern third of my
forecast area. Snow levels between 3.5k-4k feet will mean mainly
rain and graupel showers at the lower elevations with snow and
graupel in the higher mountains. Southwest winds 10 to 15 mph will
be common..but will likely become quite gusty with showers.
Temperatures will remain on the cool side of normal.
Thursday night and Friday...High pressure will build into the
region...and the mid and upper level flow will turn to the
southwest. this will tap into copious sub-tropical moisture.
PWATs increase to over a half inch which is roughly 160% of
normal. The warm front will be significant enough to over come
and Cascade shadow effect...so everyone will measure. Snow levels
increase to over 4k feet across the north to above 5k feet across
the south...so precip as mainly rain and high mountain snow.
Strong warm air advection will get mitigated by cloud cover and
precipitation...so kept temperatures close to persistence. /Tobin
Friday night through Monday: Active weather will continue across
the Inland NW through the weekend. A moist warm front will push
through the region Friday night, followed by a vigorous cold front
on Saturday with cooling, winds and convection. Snow levels will
be high, from 5-6k ft Friday day, but then fall into the valleys
by Saturday night. Post frontal westerly winds will become gusty
Saturday afternoon especially across the Columbia Basin with gusts
up to 35 mph. The GFS shows the best Iinstability along and
behind the front especially across the northern tier zones;
corresponding the the highest qpf. The cold pool aloft will settle
over the region with 500mb temperatures to -30C. Cape values look
to range from 200-400 j/kg supporting the mention of
thunderstorms, especially across northeast Washington and north
Idaho. Late Saturday night into Sunday, low level instability
decreases quickly allowing clouds and showers to diminish under
the westerly flow aloft. The cold pocket aloft will linger over
north Idaho into Sunday afternoon with popcorn type showers and a
renewed threat of thunderstorms. By Sunday night into Monday, a
shortwave upper level ridge will build over the region with some
drying, warming aloft and stabilization. Temperatures will warm
slightly with light easterly winds. This ridge is in response of a
digging trough off the west coast and leading to a slower arrival
of the next round of precipitation. /rfox.
Monday Night through Tuesday Night: Throughout this time period
conditions still look to remain active as models are bringing in
another Pacific system. Monday Night will see the transition from
the early week ridge to the mentioned incoming system. Model
consistency for the system has not been great, but this would be
expected this far out. Timing for now looks to be in the late
Monday range to reach the Cascades and then early Tuesday for the
remainder of the region. Currently the GFS brings the system
further south leading to more of the associated precip staying
south of our area, but the Euro keep it further north leading to
increased precip. With it being almost a week out, we have plenty
of time to iron out the details. Concerning temperatures we look
to remain near normal for the first part of April. Winds look to
increase as the system passes, but as to what magnitude is yet to
be determined. /Fliehman
&&
.AVIATION...
18Z TAFS: An occluded front will pass from west to east across the
region this afternoon. Isolated to scattered showers can be
expected along the front this afternoon and is expected to clear
east of KCOE between 00-03Z. The front will also bring breezy
westerly to southwesterly winds with gusts up to 20-25 mph
possible late this afternoon into this evening. We will also see a
potential for some thunderstorms this afternoon in the Cascade
Mtns and also across southeast WA and into the central ID
Panhandle. Chances for thunderstorms is small and may impact the
KEAT, KPUW and KLWS TAF sites primarily for the late afternoon and
early evening hours. Isolated showers will continue into tonight
and models are hinting at the possibility of some low stratus
early Wednesday morning at KGEG, KSFF and KCOE; however, models
may be overdoing the boundary layer moisture a bit and will likely depend
on how much rainfall we receive today. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 36 52 36 48 33 47 / 30 30 40 80 40 90
Coeur d`Alene 35 52 35 45 33 47 / 30 40 50 80 60 90
Pullman 37 52 38 47 34 49 / 60 20 70 70 40 80
Lewiston 41 58 40 52 36 55 / 70 20 70 70 40 70
Colville 34 57 33 51 34 51 / 30 30 20 70 30 90
Sandpoint 35 48 32 44 34 45 / 50 50 30 80 60 90
Kellogg 35 48 32 44 33 46 / 70 50 60 80 70 80
Moses Lake 38 59 37 57 38 55 / 20 10 20 20 20 80
Wenatchee 37 59 35 56 37 53 / 30 10 30 20 20 80
Omak 34 57 33 56 33 51 / 40 10 10 30 20 70
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$