Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/03/13
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1126 AM MDT MON APR 1 2013
.UPDATE...
ISSUED AT 1121 AM MDT MON APR 1 2013
PLAN TO DECREASE POPS SIGNIFICANTLY BETWEEN NOW AND MIDDAY
TOMORROW ACROSS MANY PARTS OF THE REGION. DRY SLOT WILL
SIGNIFICANTLY DECREASE PRECIP CHANCES BETWEEN NOW AND THEN. BEST
CHANCES OF POPS DURING THE NEXT 24H WILL BE OVER FAR E PLAINS AND
C MTN REGIONS. STILL EXPECT LOW CLOUDS TO INVADE ALL OF THE PLAINS
LATER THIS EVENING. UPDATE WILL BE ISSUED AROUND 1 PM.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM MDT MON APR 1 2013
A SHORTWAVE TROF IS WRAPPING AROUND AN UPR LOW THAT IS OVR THE WRN
STATES...AND IS BRINGING CLOUDS AND SOME PCPN TO PORTIONS OF WRN
CO...SOME OF WHICH WL AFFECT THE CONTDVD THIS MORNING. ALSO THIS
MORNING A FRONT IS CONTINUING TO MOVE SOUTHWARD THROUGH THE SERN
PLAINS AS OF 3AM IT HAD MOVED SOUTH OF THE ARKANSAS RIVER VALLEY.
HAVE SEEN SOME STRATUS DEVELOP BEHIND THIS FRONT IN NE AND PORTIONS
OF NWRN KS. THE HRRR AND NAM12 SHOW LOW LEVEL RH VALUES/STRATUS
BACKING INTO THE FAR SERN PLAINS A LITTLE LATER THIS MORNING...AND
MAYBE BACKING INTO THE FAR ERN PORTIONS OF EL PASO COUNTY. THE NAM
AND THE HRRR KEEP THE FAR SERN PLAINS DRY THRU THE MORNING
HOURS...WHILE THE GFS PRINTS OUT SOME LIGHT QPF ASSOCIATED WITH THE
STRATUS. DO NOT FEEL THAT MEASURABLE PCPN WL OCCUR SO WL KEEP THE
FORECAST DRY OUT EAST...AND WL ONLY HAVE POPS ALONG THE CONTDVD THIS
MORNING. THIS AFTERNOON THE NAM AND GFS SHOW THE BEST PCPN CHANCES
BEING OVR THE CENTRAL CO MTS AND OVR PIKES PEAK AND TELLER COUNTY.
THE NSSL WRF SHOWS PCPN IN THESE AREAS AS WELL...BUT ALSO SHOWS A
BAND OF PCPN MOVING FROM THE SW ACRS THE SWRN MTS...THE SAN LUIS
VALLEY...THE SANGRE DE CRISTO MTS...AND THEN ONTO THE ADJACENT I-25
CORRIDOR BY EARLY EVENING...AND THEN MOVING ACRS THE SERN PLAINS
THRU THE EVENING. WL LEAN CLOSER TO THE WRF`S SOLUTION. SHOULD SEE
SOME LIGHT SNOW ACCUMS OVR THE HIGHEST ELEVATIONS. TEMPS TODAY WL BE
COOLER THAN YESTERDAY OVR THE SERN PLAINS IN THE WAKE OF THE
FRONT...BUT GUIDANCE TEMPS ARE NOT IN GOOD AGREEMENT SO WL SPLIT THE
DIFFERENCE. COULD SEE SOME LOW CLOUDS HANGING AROUND OVR THE FAR
SERN CORNER INTO THE AFTERNOON WHICH WOULD KEEP TEMPS EVEN COOLER
OUT THERE. SOME WRN AREAS WL BE A LITTLE COOLER TODAY...WHILE THE
SAN LUIS VALLEY WL LIKELY SEE TEMPS SIMILAR TO THOSE ON SUN.
OVERNIGHT THE UPR LOW WL MOVE INTO ERN UT AND MUCH OF THE FORECAST
AREA ENDS UP IN THE DRY SLOT...AS SHOW IN THE NAM12...THE NSSL WRF
AND THE GFS. THE CENTRAL MTS WL PROBABLY CONTINUE TO HAVE SOME PCPN
THRU THE NIGHT...BUT SHOULD GENERALLY BE LIGHT. WITH MOIST LOW LEVEL
UPSLOPE OVR THE ERN PLAINS TONIGHT...WIDESPREAD STRATUS IS EXPECTED.
THE ONLY AREA THAT ALL THE MODELS SHOW WIDESPREAD PCPN TONIGHT IS
OVR THE FAR SERN PLAINS...SO WL GO WITH LIKELY POPS IN THAT
AREA...WITH DECREASING POPS WESTWARD TO THE ERN MTS. THE NAM AND
GFS SHOW A FEW HUNDREDTHS OF PCPN OVR THE FAR ERN AREAS OVERNIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 420 AM MDT MON APR 1 2013
TUESDAY AND WEDNESDAY...THE UPPER LOW PRES SYSTEM TRACKS FROM THE NW
TO THE SE DIRECTLY ACROSS COLORADO ON TUE AND WED...BRINGING A
DECENT SHOT AT SOME PCPN FOR THE FORECAST AREA. STARTING OUT TUE
MORNING...THE UPPER SYSTEM SHOULD BE PRODUCING SOME SHOWERS FOR THE
CENT MTS...WHILE LLVL EASTERLY UPSLOPE FLOW DUE TO SFC HI PRES OVER
NE AND KS WILL KEEP A SOLID THREAT OF PCPN FOR THE EASTERN PLAINS.
HOWEVER...AS THE UPPER LOW CONTINUES TO TRACK ACROSS THE
STATE...PCPN CHANCES SPREAD TO MUCH OF THE AREA BY TUE AFTN AND
REMAIN PROBABLE THROUGH THE NIGHT. ONGOING POP GRIDS LOOKED
REASONABLE FOR TUE NIGHT AND EARLY WED MORN WITH ONLY SLIGHT
ADJUSTMENTS NEEDED. THE TROUGH AXIS EXITS THE SE CORNER OF THE STATE
WED MID-MORNING...WITH PCPN THEN TAPERING OFF QUICKLY. AS FOR
TEMPS...MAX TEMPS IN THE 40S FOR TUE WILL GRADUALLY WARM INTO THE
50S FOR WED.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT..THE REGION DRIES OUT AS AN
UPPER RIDGE OF HIGH PRESSURE MOVES ACROSS THE 4 CORNERS. TEMPS
SHOULD REMAIN COOL FOR WED...THEN REBOUND INTO THE MID TO UPPER 60S
FOR THU.
FRIDAY THROUGH SUNDAY...THE EXTENDED MODELS WANT TO KEEP THINGS A
BIT UNSETTLED OVER THE WEEKEND. ONE DISTURBANCE ROLLS ACROSS THE
ROCKIES ON FRIDAY BUT LOOKS LIKE IT WILL STAY MAINLY TO THE NORTH OF
THE STATE. A BRIEF BREAK ON SAT...THEN SAT NIGHT ANOTHER SHORTWAVE
TRACKS ACROSS THE GREAT BASIN AND DIGS FURTHER SOUTH...PROMISING A
BETTER SHOT AT SOME BENEFICIAL PCPN. FOR THE TIME BEING...KEPT
ISOLATED POPS OVER THE MTS OVER THE WEEKEND AS THE EXTENDED
PROCEDURE PRODUCED...AND WILL HAVE TO FINE TUNE AS THAT WINDOW
NEARS. FOR THE TIME BEING...FRIDAY LOOKS LIKE THE WARMEST DAY OF THE
EXTENDED FORECAST PERIOD. MOORE
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1121 AM MDT MON APR 1 2013
I DO NOT EXPECT ANY SIGNIF PRECIP IN THE TAFS (KCOS...KPUB...KALS)
NEXT 24H. MAIN CONCERN WILL BE LOW CIGS MOVING INTO KCOS AND KPUB
AROUND MIDNIGHT TONIGHT AND LASTING THROUGH THE END OF THE TAF PD.
MVFR CIGS ARE LIKELY AT KPUB AND KCOS AFTER MIDNIGHT TONIGHT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HODANISH
SHORT TERM...28
LONG TERM...MOORE
AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1018 AM MDT MON APR 1 2013
.UPDATE...NO CHANGES TO THE FORECAST ANTICIPATED THIS TIME AROUND.
UPPER LOW CENTER HAS MOVED INTO SOUTHWESTERN UTAH WITH DEFORMATION
BAND CLOUDINESS OUT AHEAD OF IT SPREADING OVER WESTERN AND CENTRAL
COLORADO. RECENT LIGHTNING DATA PLOTS HAVE SHOWN SOME STRIKES TO
THE SOUTH OF VERNAL...UTAH AND ONE OR TWO FLASHES AROUND KGJT.
THIS IS INDICATIVE OF THE INSTABILITY PRESENT IN THE DEFORMATION
ZONE. THE CURRENT FORECASTS ALREADY MENTION SOME THUNDER OVER THE
MOUNTAINS THIS AFTERNOON...WHICH WILL BE LEFT ALONE. KCCU IS ALSO
INDICATING SOME SNOW ALREADY FALLING OVER THE HIGHER MOUNTAINS.
ACROSS THE EASTERN COLORADO PLAINS...EASTERLY FLOW WILL PERSIST
THROUGH THE DAY WHICH MAY HELP SHOWER ACTIVITY TO DEVELOP ALONG
THE FOOTHILLS LATE IN THE AFTERNOON. EACH OF THESE FEATURES IS
ADEQUATELY COVERED IN THE CURRENT FORECAST.
&&
.AVIATION...HIGH CEILINGS WILL BE DEVELOPING BY EARLY AFTERNOON
AND THEN BEGIN LOWERING BY EVENING. SCATTERED SHOWERS WILL BE
POSSIBLE THROUGH THE EVENING...BUT MOST ACTIVITY SHOULD BE CLOSER
TO THE FOOTHILLS. WINDS SHOULD REMAIN OUT OF THE EAST AND
SOUTHEAST THROUGH THE AFTERNOON. A MIX OF RAIN AND SNOW SHOWERS
ARE EXPECTED OVERNIGHT WITH A COMPLETE CHANGEOVER TO SNOW POSSIBLE
BEFORE SUNRISE TUESDAY. TEMPERATURES SHOULD BE JUST COLD ENOUGH TO
ALLOW SNOW TO FALL...BUT GROUND TEMPERATURES SHOULD BE WARM ENOUGH
TO LIMIT ANY ACCUMULATION.
&&
.PREV DISCUSSION... /ISSUED 340 AM MDT MON APR 1 2013/
SHORT TERM...AN UPPER LEVEL LOW WILL MOVE FROM NEVADA INTO UTAH
BY THIS EVENING. AHEAD OF THE LOW THE FLOW ALOFT WILL BE SWLY. AT
THE SURFACE HIGH PRES WILL BE OVER THE CNTRL PLAINS WITH LOW PRES
OVER WRN COLORADO. THIS WILL LEAD TO SELY LOW LVL FLOW OVER NERN
CO THRU TONIGHT. CROSS- SECTIONS SHOW AN INCREASE IN MOISTURE WITH
SOME MID LVL QG ASCENT MAINLY LATE TONIGHT. LAPSE RATES ARE BEST
OVER THE HIGHER TERRAIN WITH LESS INSTABILITY OVER THE PLAINS. AT
THIS TIME THE BEST CHC OF PCPN THRU THIS AFTN LOOKS TO BE IN THE
MTNS WITH DRY CONDITIONS OVER THE PLAINS. WILL MENTION SOME
THUNDER IN THE MTNS WHERE SOME CAPE EXISTS. HIGHS THIS AFTN OVER
NERN CO WILL RANGE FM THE UPPER 40S TO LOWER 50S EXCEPT POSSIBLY
ALONG THE FRONT RANGE WHERE SELY LOW LVL WINDS COMING OFF THE
PALMER DIVIDE COULD ALLOW FOR READINGS TO RISE INTO THE MID TO
UPPER 50S NR DENVER. THE RAP SHOWS HIGHS IN THE LOWER TO MID 60S
AROUND DENVER HOWEVER WILL NOT GO THIS WARM.
FOR TONIGHT SNOW SHOWERS WILL CONTINUE IN THE MTNS DUE TO INCREASING
QG ASCENT HOWEVER SWLY OROGRAPHIC FLOW MAY KEEP ACCUMULATIONS ON
THE LIGHT SIDE IN MOST AREAS. EAST OF THE MTNS THE LOW LVL FLOW
WILL REMAIN SELY. SHOULD SEE SOME SHOWERS DVLP IN THE FOOTHILLS BY
EARLY EVENING WITH SOME OF THE ACTIVITY SPREADING ACROSS THE
ADJACENT PLAINS OVERNIGHT. WITH SELY LOW LVL FLOW THE BEST CHC OF
PCPN MAY FOCUS IN THE NRN FOOTHILLS AND NORTH OF A DENVER TO LIMON
LINE. AT THIS TIME OVERALL CONFIDENCE IS NOT VERY HIGH AS TO WHERE
TO MENTION LIKELY POPS OVER THE PLAINS TONIGHT SO WILL KEEP POPS
IN THE CHC CATEGORY. SOUNDINGS SHOW WET BULB ZEROS WILL BECOME LOW
ENOUGH FOR SHOWERS TO MIX WITH OR CHANGE TO SOME SNOW AFTER
MIDNIGHT ACROSS THE PLAINS HOWEVER AT THIS TIME IT LOOKS LIKE ANY
ACCUMULATION WILL BE AN INCH OR LESS.
LONG TERM...MODELS HAVE THE UPPER CLOSED LOW OVER EAST CENTRAL
UTAH...THEN OVER THE FOUR CORNERS AT 00Z TUESDAY AFTERNOON. BY 18Z
WEDNESDAY...ITS OVER SOUTHEASTERN/ WESTERN KANSAS. ON WEDNESDAY
NIGHT...INCREASING NORTHWESTERLY FLOW ALOFT IS PROGGED FOR THE
FORECAST AREA. THE QG VERTICAL VELOCITY FIELDS HAVE UPWARD MOTION
OVER THE CWA TUESDAY AND TUESDAY NIGHT ...HOWEVER IT IS NOT VERY
STRONG. WEAK DOWNWARD MOTION IS PROGGED WEDNESDAY AND WEDNESDAY
NIGHT. NORTHEAST TO SOUTHEASTERLY LOW LEVEL WINDS ARE PROGGED FOR
THE PLAINS AND FOOTHILLS TUESDAY AND TUESDAY EVENING. WEAK FLOW IS
PROGGED THE REST OF TUESDAY NIGHT THROUGH WEDNESDAY...WITH A
COMBINATION OF NORMAL DUIRNAL PATTERNS TO WEAK DOWNSLOPING
WEDNESDAY NIGHT. MOISTURE IS FAIRLY DEEP ON TUESDAY FOR MOST OF
THE CWA. IT IS PRETTY DEEP ON THE NAM TUESDAY NIGHT...DRIER ON THE
GFS. IT DRIES OUT SOMEWHAT ON WEDNESDAY. THERE IS SOME MOUNTAIN
MOISTURE WEDNESDAY NIGHT...BUT ITS DRIER ON THE PLAINS. MODELS
SHOW MINOR CAPE OVER THE MOUNTAINS AND FOOTHILLS LATE DAY TUESDAY
AND AGAIN WEDNESDAY AFTERNOON. THE QPF FIELDS SHOW MEASURABLE
PRECIPITATION TUESDAY AND TUESDAY EVENING FOR MOST AREAS...BEST
OVER THE FOOTHILLS AND EASTERN MOUNTIANS ZONES. THERE IS A TAD THE
REST OF TUESDAY NIGHT AND WEDNESDAY... MAINLY OVER THE MOUNTIANS.
FOR POPS...WILL KEEP THE "LIKELY"S IN OVER THE MOUNTAINS AND
"CHANCES" OUT ON THE PLAINS TUESDAY AND TUESDAY EVENING. THE
PLAINS WILL SEE BOTH SNOW AND RAIN...WITH LITTLE ACCUMULATION.
WILL DECREASE POPS THE REST OF TUESDAY NIGHT. ON WEDNESDAY...JUST
SOME MINOR ALPINE POPS. WILL PUT "ISOLATED" THUNDER IN BOTH
TUESDAY AND WEDNESDAY AFTERNOONS IN THE MOUNTIANS. FOR
TEMPERATURES...TUESDAY`S HIGHS ARE 2.0-3.5 C COOLER THAN TODAY`S
EXPECTED HIGHS. WEDNESDAY`S READINGS COME UP 3-7 C FROM TUESDAY`S.
FOR THE LATER DAYS...THURSDAY THROUGH SUNDAY...MODELS HAVE UPPER
RIDGING FOR COLORADO THROUGH MID DAY FRIDAY...THEN A WEAK UPPER
TROUGH IS PROGGED ACROSS THE STATE BY EARLY SATURDAY MORNING.
AFTER THAT...WEST-SOUTHWESTERLY FLOW ALOFT IS PROGGED OVER THE CWA
THROUGH SUNDAY. THERE IS LIMITED MOISTURE AROUND...BUT IT
INCREASES ON SUNDAY.
AVIATION...SO FAR ANY STRATUS WAS CONFINED TO THE FAR NERN CORNER
OF THE PLAINS SO AT THIS POINT IT DOES NOT APPEAR IT WILL AFFECT
THE AIRPORT THIS MORNING. AS FOR WINDS BOTH THE RAP AND HRR SHOW A
DENVER CYCLONE DEVELOPING SW OF DENVER WITH WINDS BEING E TO SE
THRU THE AFTN. COULD SEE SUSTAINED WINDS IN THE 15 TO 20 MPH BY
20Z. AT THIS TIME ANY CHC FOR RAIN SHOWERS WILL BE AFTER 00Z.
COULD SEE SHOWERS CHANGE TO SOME SNOW AFTER MIDNIGHT BUT ANY
ACCUMULATION WILL BE UNDER ONE HALF INCH AND CONFINED TO GRASSY
AREAS. LATEST NAM CONTINUES TO SHOW A CYCLONE OVERNIGHT OVER
DENVER WITH WINDS BECOMING MORE SLY AFTER MIDNIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DANKERS
LONG TERM....99
AVIATION...DANKERS
AREA FORECAST DISCUSSION
NWS PUEBLO CO
421 AM MDT MON APR 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM MDT MON APR 1 2013
A SHORTWAVE TROF IS WRAPPING AROUND AN UPR LOW THAT IS OVR THE WRN
STATES...AND IS BRINGING CLOUDS AND SOME PCPN TO PORTIONS OF WRN
CO...SOME OF WHICH WL AFFECT THE CONTDVD THIS MORNING. ALSO THIS
MORNING A FRONT IS CONTINUING TO MOVE SOUTHWARD THROUGH THE SERN
PLAINS AS OF 3AM IT HAD MOVED SOUTH OF THE ARKANSAS RIVER VALLEY.
HAVE SEEN SOME STRATUS DEVELOP BEHIND THIS FRONT IN NE AND PORTIONS
OF NWRN KS. THE HRRR AND NAM12 SHOW LOW LEVEL RH VALUES/STRATUS
BACKING INTO THE FAR SERN PLAINS A LITTLE LATER THIS MORNING...AND
MAYBE BACKING INTO THE FAR ERN PORTIONS OF EL PASO COUNTY. THE NAM
AND THE HRRR KEEP THE FAR SERN PLAINS DRY THRU THE MORNING
HOURS...WHILE THE GFS PRINTS OUT SOME LIGHT QPF ASSOCIATED WITH THE
STRATUS. DO NOT FEEL THAT MEASURABLE PCPN WL OCCUR SO WL KEEP THE
FORECAST DRY OUT EAST...AND WL ONLY HAVE POPS ALONG THE CONTDVD THIS
MORNING. THIS AFTERNOON THE NAM AND GFS SHOW THE BEST PCPN CHANCES
BEING OVR THE CENTRAL CO MTS AND OVR PIKES PEAK AND TELLER COUNTY.
THE NSSL WRF SHOWS PCPN IN THESE AREAS AS WELL...BUT ALSO SHOWS A
BAND OF PCPN MOVING FROM THE SW ACRS THE SWRN MTS...THE SAN LUIS
VALLEY...THE SANGRE DE CRISTO MTS...AND THEN ONTO THE ADJACENT I-25
CORRIDOR BY EARLY EVENING...AND THEN MOVING ACRS THE SERN PLAINS
THRU THE EVENING. WL LEAN CLOSER TO THE WRF`S SOLUTION. SHOULD SEE
SOME LIGHT SNOW ACCUMS OVR THE HIGHEST ELEVATIONS. TEMPS TODAY WL BE
COOLER THAN YESTERDAY OVR THE SERN PLAINS IN THE WAKE OF THE
FRONT...BUT GUIDANCE TEMPS ARE NOT IN GOOD AGREEMENT SO WL SPLIT THE
DIFFERENCE. COULD SEE SOME LOW CLOUDS HANGING AROUND OVR THE FAR
SERN CORNER INTO THE AFTERNOON WHICH WOULD KEEP TEMPS EVEN COOLER
OUT THERE. SOME WRN AREAS WL BE A LITTLE COOLER TODAY...WHILE THE
SAN LUIS VALLEY WL LIKELY SEE TEMPS SIMILAR TO THOSE ON SUN.
OVERNIGHT THE UPR LOW WL MOVE INTO ERN UT AND MUCH OF THE FORECAST
AREA ENDS UP IN THE DRY SLOT...AS SHOW IN THE NAM12...THE NSSL WRF
AND THE GFS. THE CENTRAL MTS WL PROBABLY CONTINUE TO HAVE SOME PCPN
THRU THE NIGHT...BUT SHOULD GENERALLY BE LIGHT. WITH MOIST LOW LEVEL
UPSLOPE OVR THE ERN PLAINS TONIGHT...WIDESPREAD STRATUS IS EXPECTED.
THE ONLY AREA THAT ALL THE MODELS SHOW WIDESPREAD PCPN TONIGHT IS
OVR THE FAR SERN PLAINS...SO WL GO WITH LIKELY POPS IN THAT
AREA...WITH DECREASING POPS WESTWARD TO THE ERN MTS. THE NAM AND
GFS SHOW A FEW HUNDREDTHS OF PCPN OVR THE FAR ERN AREAS OVERNIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 420 AM MDT MON APR 1 2013
TUESDAY AND WEDNESDAY...THE UPPER LOW PRES SYSTEM TRACKS FROM THE NW
TO THE SE DIRECTLY ACROSS COLORADO ON TUE AND WED...BRINGING A
DECENT SHOT AT SOME PCPN FOR THE FORECAST AREA. STARTING OUT TUE
MORNING...THE UPPER SYSTEM SHOULD BE PRODUCING SOME SHOWERS FOR THE
CENT MTS...WHILE LLVL EASTERLY UPSLOPE FLOW DUE TO SFC HI PRES OVER
NE AND KS WILL KEEP A SOLID THREAT OF PCPN FOR THE EASTERN PLAINS.
HOWEVER...AS THE UPPER LOW CONTINUES TO TRACK ACROSS THE
STATE...PCPN CHANCES SPREAD TO MUCH OF THE AREA BY TUE AFTN AND
REMAIN PROBABLE THROUGH THE NIGHT. ONGOING POP GRIDS LOOKED
REASONABLE FOR TUE NIGHT AND EARLY WED MORN WITH ONLY SLIGHT
ADJUSTMENTS NEEDED. THE TROUGH AXIS EXITS THE SE CORNER OF THE STATE
WED MID-MORNING...WITH PCPN THEN TAPERING OFF QUICKLY. AS FOR
TEMPS...MAX TEMPS IN THE 40S FOR TUE WILL GRADUALLY WARM INTO THE
50S FOR WED.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT..THE REGION DRIES OUT AS AN
UPPER RIDGE OF HIGH PRESSURE MOVES ACROSS THE 4 CORNERS. TEMPS
SHOULD REMAIN COOL FOR WED...THEN REBOUND INTO THE MID TO UPPER 60S
FOR THU.
FRIDAY THROUGH SUNDAY...THE EXTENDED MODELS WANT TO KEEP THINGS A
BIT UNSETTLED OVER THE WEEKEND. ONE DISTURBANCE ROLLS ACROSS THE
ROCKIES ON FRIDAY BUT LOOKS LIKE IT WILL STAY MAINLY TO THE NORTH OF
THE STATE. A BRIEF BREAK ON SAT...THEN SAT NIGHT ANOTHER SHORTWAVE
TRACKS ACROSS THE GREAT BASIN AND DIGS FURTHER SOUTH...PROMISING A
BETTER SHOT AT SOME BENEFICIAL PCPN. FOR THE TIME BEING...KEPT
ISOLATED POPS OVER THE MTS OVER THE WEEKEND AS THE EXTENDED
PROCEDURE PRODUCED...AND WILL HAVE TO FINE TUNE AS THAT WINDOW
NEARS. FOR THE TIME BEING...FRIDAY LOOKS LIKE THE WARMEST DAY OF THE
EXTENDED FORECAST PERIOD. MOORE
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 420 AM MDT MON APR 1 2013
EXPECT VFR CONDITIONS TODAY AT KALS...KPUB AND KCOS. THERE COULD BE
A FEW LOW CLOUDS IN THE VCNTY OF KCOS THIS MORNING. EARLY THIS
EVENING THERE COULD BE A FEW SHOWERS AND MAYBE EVEN A THUNDERSTORMS
AT OR IN THE VCNTY OF KCOS...PROBABLY AFTER 22Z AND BEFORE 03Z.
KALS COULD ALSO SEE SOME SHOWERS OR A THUNDERSTORM IN THE
AREA...MAINLY AFTER 18Z AND BEFORE 01Z. KALS SHOULD HAVE VFR
CONDITIONS TONIGHT. KCOS AND KPUB SHOULD SEE LOW CLOUDS MOVE INTO
THE AREA AROUND 06Z WITH IFR CONDITIONS EXPECTED.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...28
LONG TERM...MOORE
AVIATION...28
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
340 AM MDT MON APR 1 2013
.SHORT TERM...AN UPPER LEVEL LOW WILL MOVE FROM NEVADA INTO UTAH
BY THIS EVENING. AHEAD OF THE LOW THE FLOW ALOFT WILL BE SWLY. AT
THE SURFACE HIGH PRES WILL BE OVER THE CNTRL PLAINS WITH LOW PRES
OVER WRN COLORADO. THIS WILL LEAD TO SELY LOW LVL FLOW OVER NERN
CO THRU TONIGHT. CROSS- SECTIONS SHOW AN INCREASE IN MOISTURE WITH
SOME MID LVL QG ASCENT MAINLY LATE TONIGHT. LAPSE RATES ARE BEST
OVER THE HIGHER TERRAIN WITH LESS INSTABILITY OVER THE PLAINS. AT
THIS TIME THE BEST CHC OF PCPN THRU THIS AFTN LOOKS TO BE IN THE
MTNS WITH DRY CONDITIONS OVER THE PLAINS. WILL MENTION SOME
THUNDER IN THE MTNS WHERE SOME CAPE EXISTS. HIGHS THIS AFTN OVER
NERN CO WILL RANGE FM THE UPPER 40S TO LOWER 50S EXCEPT POSSIBLY
ALONG THE FRONT RANGE WHERE SELY LOW LVL WINDS COMING OFF THE
PALMER DIVIDE COULD ALLOW FOR READINGS TO RISE INTO THE MID TO
UPPER 50S NR DENVER. THE RAP SHOWS HIGHS IN THE LOWER TO MID 60S
AROUND DENVER HOWEVER WILL NOT GO THIS WARM.
FOR TONIGHT SNOW SHOWERS WILL CONTINUE IN THE MTNS DUE TO INCREASING
QG ASCENT HOWEVER SWLY OROGRAPHIC FLOW MAY KEEP ACCUMULATIONS ON
THE LIGHT SIDE IN MOST AREAS. EAST OF THE MTNS THE LOW LVL FLOW
WILL REMAIN SELY. SHOULD SEE SOME SHOWERS DVLP IN THE FOOTHILLS BY
EARLY EVENING WITH SOME OF THE ACTIVITY SPREADING ACROSS THE
ADJACENT PLAINS OVERNIGHT. WITH SELY LOW LVL FLOW THE BEST CHC OF
PCPN MAY FOCUS IN THE NRN FOOTHILLS AND NORTH OF A DENVER TO LIMON
LINE. AT THIS TIME OVERALL CONFIDENCE IS NOT VERY HIGH AS TO WHERE
TO MENTION LIKELY POPS OVER THE PLAINS TONIGHT SO WILL KEEP POPS
IN THE CHC CATEGORY. SOUNDINGS SHOW WET BULB ZEROS WILL BECOME LOW
ENOUGH FOR SHOWERS TO MIX WITH OR CHANGE TO SOME SNOW AFTER
MIDNIGHT ACROSS THE PLAINS HOWEVER AT THIS TIME IT LOOKS LIKE ANY
ACCUMULATION WILL BE AN INCH OR LESS.
.LONG TERM...MODELS HAVE THE UPPER CLOSED LOW OVER EAST CENTRAL
UTAH...THEN OVER THE FOUR CORNERS AT 00Z TUESDAY AFTERNOON. BY 18Z
WEDNESDAY...ITS OVER SOUTHEASTERN/ WESTERN KANSAS. ON WEDNESDAY
NIGHT...INCREASING NORTHWESTERLY FLOW ALOFT IS PROGGED FOR THE
FORECAST AREA. THE QG VERTICAL VELOCITY FIELDS HAVE UPWARD MOTION
OVER THE CWA TUESDAY AND TUESDAY NIGHT ...HOWEVER IT IS NOT VERY
STRONG. WEAK DOWNWARD MOTION IS PROGGED WEDNESDAY AND WEDNESDAY
NIGHT. NORTHEAST TO SOUTHEASTERLY LOW LEVEL WINDS ARE PROGGED FOR
THE PLAINS AND FOOTHILLS TUESDAY AND TUESDAY EVENING. WEAK FLOW IS
PROGGED THE REST OF TUESDAY NIGHT THROUGH WEDNESDAY...WITH A
COMBINATION OF NORMAL DUIRNAL PATTERNS TO WEAK DOWNSLOPING
WEDNESDAY NIGHT. MOISTURE IS FAIRLY DEEP ON TUESDAY FOR MOST OF
THE CWA. IT IS PRETTY DEEP ON THE NAM TUESDAY NIGHT...DRIER ON THE
GFS. IT DRIES OUT SOMEWHAT ON WEDNESDAY. THERE IS SOME MOUNTAIN
MOISTURE WEDNESDAY NIGHT...BUT ITS DRIER ON THE PLAINS. MODELS
SHOW MINOR CAPE OVER THE MOUNTAINS AND FOOTHILLS LATE DAY TUESDAY
AND AGAIN WEDNESDAY AFTERNOON. THE QPF FIELDS SHOW MEASURABLE
PRECIPITATION TUESDAY AND TUESDAY EVENING FOR MOST AREAS...BEST
OVER THE FOOTHILLS AND EASTERN MOUNTIANS ZONES. THERE IS A TAD THE
REST OF TUESDAY NIGHT AND WEDNESDAY... MAINLY OVER THE MOUNTIANS.
FOR POPS...WILL KEEP THE "LIKELY"S IN OVER THE MOUNTAINS AND
"CHANCES" OUT ON THE PLAINS TUESDAY AND TUESDAY EVENING. THE
PLAINS WILL SEE BOTH SNOW AND RAIN...WITH LITTLE ACCUMULATION.
WILL DECREASE POPS THE REST OF TUESDAY NIGHT. ON WEDNESDAY...JUST
SOME MINOR ALPINE POPS. WILL PUT "ISOLATED" THUNDER IN BOTH
TUESDAY AND WEDNESDAY AFTERNOONS IN THE MOUNTIANS. FOR
TEMPERATURES...TUESDAY`S HIGHS ARE 2.0-3.5 C COOLER THAN TODAY`S
EXPECTED HIGHS. WEDNESDAY`S READINGS COME UP 3-7 C FROM TUESDAY`S.
FOR THE LATER DAYS...THURSDAY THROUGH SUNDAY...MODELS HAVE UPPER
RIDGING FOR COLORADO THROUGH MID DAY FRIDAY...THEN A WEAK UPPER
TROUGH IS PROGGED ACROSS THE STATE BY EARLY SATURDAY MORNING.
AFTER THAT...WEST-SOUTHWESTERLY FLOW ALOFT IS PROGGED OVER THE CWA
THROUGH SUNDAY. THERE IS LIMITED MOISTURE AROUND...BUT IT
INCREASES ON SUNDAY.
&&
.AVIATION...SO FAR ANY STRATUS WAS CONFINED TO THE FAR NERN CORNER
OF THE PLAINS SO AT THIS POINT IT DOES NOT APPEAR IT WILL AFFECT
THE AIRPORT THIS MORNING. AS FOR WINDS BOTH THE RAP AND HRR SHOW A
DENVER CYCLONE DEVELOPING SW OF DENVER WITH WINDS BEING E TO SE
THRU THE AFTN. COULD SEE SUSTAINED WINDS IN THE 15 TO 20 MPH BY
20Z. AT THIS TIME ANY CHC FOR RAIN SHOWERS WILL BE AFTER 00Z.
COULD SEE SHOWERS CHANGE TO SOME SNOW AFTER MIDNIGHT BUT ANY
ACCUMULATION WILL BE UNDER ONE HALF INCH AND CONFINED TO GRASSY
AREAS. LATEST NAM CONTINUES TO SHOW A CYCLONE OVERNIGHT OVER
DENVER WITH WINDS BECOMING MORE SLY AFTER MIDNIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM....RJK
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS MIAMI FL
150 PM EDT MON APR 1 2013
.AVIATION...
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CONTINUE DEVELOPING
ACROSS THE EASTERN PORTION OF THE PENINSULA THIS AFTERNOON. FOR
THE VERY SHORT TERM...SHOWERS AND THUNDERSTORMS ARE IN THE
VICINITY OF TERMINALS KTMB...KMIA AND KOPF WITH BRIEF PERIODS OF
IFR CONDITIONS POSSIBLE. THERE IS A SLIGHT RISK OF SEVERE WEATHER
WITH ANY THUNDERSTORMS THAT DEVELOP THIS AFTERNOON AND EARLY
EVENING. AFTER THE EARLY EVENING HOURS THE POTENTIAL FOR
CONVECTION WILL START TO DECREASE. FOR THE EAST COAST
TERMINALS...AS SOUTHWESTERLY WINDS CONTINUE TO DEVELOP THE CHANCES
OF A SEA BREEZE THIS AFTERNOON ARE DIMINISHING BUT WINDS COULD BE
SOMEWHAT VARIABLE AT TIMES.
60
&&
.PREV DISCUSSION... /ISSUED 1031 AM EDT MON APR 1 2013/
UPDATE...
THE MORNING SURFACE ANALYSIS SHOWED A HIGH PRESSURE RIDGE AXIS
EXTENDING WEST ACROSS SOUTH FLORIDA AND THE SOUTHEAST GULF OF
MEXICO AND A COLD FRONT APPROACHING FROM THE NORTH. SSW LOW-LEVEL
FLOW IS EXPECTED TO GRADUALLY VEER TOWARD THE WEST THROUGH THE
COURSE OF THE DAY AS THIS BOUNDARY CONTINUES SOUTH. THIS FLOW
COMBINED WITH THE AFTERNOON EAST COAST SEA BREEZE...A COUPLE OF
IMPULSES ALOFT AND MODERATE INSTABILITY AND SHEAR (0-6KM 30-35 KT)
COULD GENERATE A FEW STRONG TO EVEN SEVERE THUNDERSTORMS THROUGH
THE AFTERNOON/EVENING PERIOD TODAY OVER THE METRO/EAST COAST
LOCATIONS. THE LATEST WRF AND HRRR MODEL REFLECTIVITIES...
HOWEVER...ARE ONLY INDICATING ISOLATED COVERAGE OVER THESE AREAS
AT BEST THROUGH THIS TIME. ANY STORMS THAT DO INITIATE COULD BE
CAPABLE OF PRODUCING STRONG WINDS, HAIL AND POSSIBLY A TORNADO.
THE LATEST FORECAST HAS BEEN UPDATED TO REFLECT THIS POTENTIAL
THIS AFTERNOON. ELSEWHERE...VISIBILITIES HAVE BEGUN TO IMPROVE
OVER THE PAST HOUR ACROSS THE INTERIOR LOCATIONS FROM THE EARLY
MORNING FOG AND THIS TREND IS EXPECTED TO CONTINUE. THE LOCAL
OFFICIALS HAVE REPORTED THAT SEGMENTS OF I-75 HAVE BEEN CLOSED
TODAY DUE TO A COMBINATION OF THIS FOG EARLIER AND SMOKE FROM THE
ONGOING WILDFIRE IN COLLIER COUNTY.
PREV DISCUSSION... /ISSUED 739 AM EDT MON APR 1 2013/
AVIATION...
AN UPPER LEVEL SHORTWAVE ACROSS THE EASTERN GULF WILL MOVE ACROSS
THE FLORIDA PENINSULA TODAY. A FEW SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE MAINLY TO THE EAST OF THE EAST COAST TAF SITES THIS
MORNING. SEA BREEZE BOUNDARIES EARLY THIS AFTERNOON ARE EXPECTED TO
HELP GENERATE SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS NEAR THE
EAST COAST TAF SITES. SO ADDED VCTS FOR THE EAST COAST TAFS. FOR
KAPF...THERE IS A SLIGHT CHANCE OF SHOWERS AHEAD OF THE
TROUGH...MAINLY BEFORE 18Z. WIND DIRECTION MAY VARY BETWEEN 160-210
DEGREES DURING THE DAY AT THE EAST COAST TAF SITES. WINDS WILL SHIFT
TO THE WEST TO NORTHWEST TONIGHT BEHIND THE BOUNDARY.
PREV DISCUSSION... /ISSUED 459 AM EDT MON APR 1 2013/
DISCUSSION...
CURRENTLY, A MID LEVEL TROUGH, ROUGHLY AT 700 MB, IS MOVING ACROSS
THE EASTERN GULF OF MEXICO. THIS HAS GENERATED A LINE OF
THUNDERSTORMS THAT IS EXPECTED TO FALL APART AS IT APPROACHES
CENTRAL FLORIDA. THIS TROUGH, ACCORDING TO THE HRRR, MAY SPARK OFF
A FEW SHOWERS OVER SOUTH FLORIDA THIS MORNING. ALSO, ANOTHER SHORT
WAVE HAS GENERATED SOME SHOWERS AND ISOLATED THUNDERSTORMS OVER
THE FLORIDA STRAITS. THESE ARE MOVING NORTH NORTHEAST. THE SHOWERS
WILL AFFECT THE SOUTHEASTERN PORTION OF THE CWA THIS MORNING. THE
QUESTION IS IF THERE WILL BE ANY THUNDERSTORMS THAT MOVE INTO THE
AREA AS WELL. THERE IS AROUND 1000 JOULES JUST ONSHORE, AROUND
HOMESTEAD AND MIAMI. SO, ALTHOUGH ORIGINAL THINKING WAS THEY WOULD
STAY OFFSHORE, MAY HAVE TO ADD A MENTION OF THUNDERSTORMS FOR THIS
AREA THIS MORNING.
AS FOR LATER TODAY, MODELS INDICATE THE TROUGH, OR REALLY, A
WEAKENING FRONT, WILL MOVE ONSHORE THE GULF COAST LATER THIS
MORNING. MODELS ARE INDICATING IT WILL NOT BE TOO ACTIVE,
CONVECTION WISE WHEN IT DOES. BUT, AS IT PROGRESS ACROSS THE
STATE, ALONG WITH DAYTIME HEATING, CONVECTION MAY BE ABLE TO
INITIATE. THE MODELS DO DIFFER GREATLY WITH HOW MUCH CAPE WILL BE
AVAILABLE. THE GFS KEEPS THE HIGHEST BOUNDARY LAYER CAPE VALUES
WELL OFFSHORE AND ONLY 500-600 JOULES OVER THE ATLANTIC COAST. THE
NAM, ON THE OTHER HAND, HAS 1200 TO 1600 JOULES OVER THE ATLANTIC
COAST, NEAT WEST PALM BEACH, AND DROPS TO 500-700 JOULES NEAR
MIAMI. NOW THE NAM MODEL SOUNDINGS HAVE 1200-1600 JOULES ALL OVER
THE ATLANTIC COAST. THEY DO SHOW A WEAK CAP FURTHER NORTH, BUT IT
IS SO WEAK, NOT THINKING IT WILL BE A REAL INHIBITOR. THERE IS
ALSO A TOUCH OF CIN TO THE NORTH AS WELL, BUT AGAIN, NOTHING THAT
REALLY SHOULD INHIBIT DEVELOPMENT. SO, WHAT WILL INHIBIT THEIR
DEVELOPMENT. WELL, MODELS DO SHOW THAT THE CAPE WILL BE PUSHING
OFF TO THE EAST, AHEAD OF THE TROUGH. SO, WE MAY BE LACKING THE
LIFTING MECHANISM. IT MAY ARRIVE WELL AFTER THE CAPE HAS PUSHED
OFF SHORE. SO, HAVE KEPT CHC POPS AND SLIGHT CHC TSTMS, BUT HAVE
BROADENED THE COVERAGE OF TSTMS THIS AFTERNOON.
BEHIND THE TROUGH TODAY, HIGH PRESSURE WILL BE BUILDING IN FAIRLY
QUICK. THIS WILL BRING QUIET WEATHER BACK TO SOUTH FLORIDA FOR A
FEW DAYS.
FOR FRIDAY AND THE WEEKEND, A LOW PRESSURE SYSTEM WILL DEVELOP
OVER THE WESTERN GULF AND MOVE OVER THE FLORIDA PANHANDLE THURSDAY
NIGHT/FRIDAY MORNING. A COLD FRONT WILL MOVE THROUGH SOUTH FLORIDA
FRIDAY. THIS SYSTEM WILL BRING OUR NEXT CHANCE FOR RAIN AND
POSSIBLY A THUNDERSTORM. MODELS ARE IN PRETTY GOOD AGREEMENT WITH
THE STRENGTH, POSITION, AND TIMING OF THIS SYSTEM. GIVEN THIS,
HAVE A HIGH CHC POP IN THE FORECAST FOR FRIDAY. BEHIND THE FRONT,
HIGH PRESSURE WILL BUILD IN ONCE AGAIN. TEMPERATURES WILL NOT BE
MUCH COOLER, ONLY A FEW DEGREES. THIS HIGH PRESSURE WILL LAST FOR
THE REMAINDER OF THE EXTENDED FORECAST.
MARINE...
WINDS AHEAD OF A WEAK FRONT/TROUGH WILL PICK UP OUT OF THE SOUTH
TO BETWEEN 13 AND 19 KTS OVER THE ATLANTIC WATERS. THEY SHOULD
REMAIN BELOW 10 KTS OVER THE GULF WATERS. THE HIGHER WIND SPEEDS
OVER THE ATLANTIC WATERS HAS PROMPTED A SMALL CRAFT SHOULD
EXERCISE CAUTION STATEMENT FOR THIS AFTERNOON. SEAS TODAY WILL BE
SUBSIDING SOMEWHAT, EVEN WITH THE WINDS, AND ARE EXPECTED TO BE 1
TO 3 FEET BY TOMORROW IN THE ATLANTIC WATERS. THE GULF WATERS WILL
BE AROUND 1 FOOT FOR THE NEXT COUPLE OF DAYS. HIGH PRESSURE WILL
BUILD IN BEGINNING TONIGHT. THIS WILL CAUSE WINDS TO WEAKEN SOME
TONIGHT TO 7-10 KTS OVER THE ATLANTIC AND SHIFT THEM OUT OF THE
NORTH TOMORROW.
FIRE WEATHER...
THE MAIN FIRE WEATHER CONCERN TODAY ARE THE SHIFTING WINDS. AN
APPROACHING FRONT/TROUGH WILL CAUSE WINDS TO PICK UP SOME TODAY TO
10 TO 15 MPH OVER GLADES, HENDRY, AND INTERIOR COLLIER COUNTIES.
THEY WILL BEGIN OUT OF THE SOUTHEAST, BUT TURN THROUGH THE DAY TO
THE SOUTH, THEN SOUTHWEST BY EARLY AFTERNOON. BY THIS EVENING,
THEY WILL BECOME WESTERLY BETWEEN 5 AND 10 MPH. ALONG WITH THIS
WIND SHIFT, WILL BE THE CHANCE FOR SOME RAIN SHOWERS AND A SLIGHT
CHANCE FOR A THUNDERSTORM. THE CHANCES INCREASE AS YOU GO EASTWARD
ACROSS SOUTH FLORIDA. IN THE INTERIOR PORTION OF THE AREA, THE
DIVIDING LINE FOR THE CHANCE OF AND THUNDERSTORMS IS A DIFFICULT
ONE AT BEST. SO, AREAS WEST OF THE FORECASTED AREA, SHOULD REMAIN
AWARE OF THE POSSIBILITY THAT THE FORECAST COULD CHANGE TO INCLUDE
THEM AS THE TROUGH GETS CLOSER. ONE THE OTHER HAND, IT COULD ALSO
BE PUSHED FURTHER EAST. THERE IS JUST GREAT UNCERTAINTY WITH THE
CONVECTIVE DEVELOPMENT TODAY.
BEHIND THE TROUGH, HIGH PRESSURE WILL BUILD IN THROUGH THURSDAY,
BRINGING QUIET WEATHER BACK TO SOUTH FLORIDA.
PREV DISCUSSION... /ISSUED 241 AM EDT MON APR 1 2013/
AVIATION...
ISOLATED SHOWERS WERE MOVING ACROSS THE ATLANTIC WATERS AND NEAR
KFLL AND FXE. ANOTHER AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS
WERE MOVING JUST SOUTH OF THE KEYS. THIS AREA OF SHOWERS AND
STORMS WILL CONTINUE TO MOVE NORTHWARD OVERNIGHT...AND COULD GET
NEAR KTMB AND KMIA IN THE NEXT FEW HOURS IF THEY HOLD TOGETHER. A
SHORTWAVE TROUGH MOVING ACROSS THE EASTERN GULF WAS FORCING
SHOWERS AND THUNDERSTORMS TO DEVELOP WEST OF TAMPA. THE HRRR
KEEPS THIS LINE TOGETHER AND MOVES IT TOWARDS KAPF AROUND 16Z.
OTHER SHOWERS OR STORMS COULD ALSO BEGIN DEVELOPING ON THE EAST
COAST SEA BREEZE AROUND THIS TIME. THE WIND DIRECTION IS ALSO
TRICKY TODAY AS THE BOUNDARY LAYER WINDS SHIFT TO THE SOUTHWEST
AHEAD OF THE TROUGH AND WEAK COLD FRONT. SO THE WINDS MAY SHIFT TO
THE SOUTHWEST FOR A TIME LATE IN THE MORNING BEFORE THE EAST COAST
SEA BREEZE BOUNDARY TRIES TO PUSH THE WINDS BACK TO THE SOUTH OR
SOUTHEAST. BY 00Z...SOUTHWESTERLY FLOW IS EXPECTED TO
PREVAIL...WITH WEST TO NORTHWESTERLY FLOW BEHIND THE SURFACE
TROUGH AFTER 02-04Z. SO FOR THE TAFS...KEPT VCSH FOR NOW...BUT
MAY NEED TO ADD VCTS. MVFR CONDITIONS ARE POSSIBLE NEAR ANY
SHOWERS OR STORMS THAT FORM.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 65 81 67 81 / 20 10 - 10
FORT LAUDERDALE 68 84 71 83 / 20 10 - 10
MIAMI 68 85 69 82 / 20 10 - 10
NAPLES 65 83 64 85 / 10 10 - 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS MIAMI FL
1031 AM EDT MON APR 1 2013
.UPDATE...
THE MORNING SURFACE ANALYSIS SHOWED A HIGH PRESSURE RIDGE AXIS
EXTENDING WEST ACROSS SOUTH FLORIDA AND THE SOUTHEAST GULF OF
MEXICO AND A COLD FRONT APPROACHING FROM THE NORTH. SSW LOW-LEVEL
FLOW IS EXPECTED TO GRADUALLY VEER TOWARD THE WEST THROUGH THE
COURSE OF THE DAY AS THIS BOUNDARY CONTINUES SOUTH. THIS FLOW
COMBINED WITH THE AFTERNOON EAST COAST SEA BREEZE...A COUPLE OF
IMPULSES ALOFT AND MODERATE INSTABILITY AND SHEAR (0-6KM 30-35 KT)
COULD GENERATE A FEW STRONG TO EVEN SEVERE THUNDERSTORMS THROUGH
THE AFTERNOON/EVENING PERIOD TODAY OVER THE METRO/EAST COAST
LOCATIONS. THE LATEST WRF AND HRRR MODEL REFLECTIVITIES...
HOWEVER...ARE ONLY INDICATING ISOLATED COVERAGE OVER THESE AREAS
AT BEST THROUGH THIS TIME. ANY STORMS THAT DO INITIATE COULD BE
CAPABLE OF PRODUCING STRONG WINDS, HAIL AND POSSIBLY A TORNADO.
THE LATEST FORECAST HAS BEEN UPDATED TO REFLECT THIS POTENTIAL
THIS AFTERNOON. ELSEWHERE...VISIBILITIES HAVE BEGUN TO IMPROVE
OVER THE PAST HOUR ACROSS THE INTERIOR LOCATIONS FROM THE EARLY
MORNING FOG AND THIS TREND IS EXPECTED TO CONTINUE. THE LOCAL
OFFICIALS HAVE REPORTED THAT SEGMENTS OF I-75 HAVE BEEN CLOSED
TODAY DUE TO A COMBINATION OF THIS FOG EARLIER AND SMOKE FROM THE
ONGOING WILDFIRE IN COLLIER COUNTY.
&&
.PREV DISCUSSION... /ISSUED 739 AM EDT MON APR 1 2013/
AVIATION...
AN UPPER LEVEL SHORTWAVE ACROSS THE EASTERN GULF WILL MOVE ACROSS
THE FLORIDA PENINSULA TODAY. A FEW SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE MAINLY TO THE EAST OF THE EAST COAST TAF SITES THIS
MORNING. SEA BREEZE BOUNDARIES EARLY THIS AFTERNOON ARE EXPECTED TO
HELP GENERATE SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS NEAR THE
EAST COAST TAF SITES. SO ADDED VCTS FOR THE EAST COAST TAFS. FOR
KAPF...THERE IS A SLIGHT CHANCE OF SHOWERS AHEAD OF THE
TROUGH...MAINLY BEFORE 18Z. WIND DIRECTION MAY VARY BETWEEN 160-210
DEGREES DURING THE DAY AT THE EAST COAST TAF SITES. WINDS WILL SHIFT
TO THE WEST TO NORTHWEST TONIGHT BEHIND THE BOUNDARY.
PREV DISCUSSION... /ISSUED 459 AM EDT MON APR 1 2013/
DISCUSSION...
CURRENTLY, A MID LEVEL TROUGH, ROUGHLY AT 700 MB, IS MOVING ACROSS
THE EASTERN GULF OF MEXICO. THIS HAS GENERATED A LINE OF
THUNDERSTORMS THAT IS EXPECTED TO FALL APART AS IT APPROACHES
CENTRAL FLORIDA. THIS TROUGH, ACCORDING TO THE HRRR, MAY SPARK OFF
A FEW SHOWERS OVER SOUTH FLORIDA THIS MORNING. ALSO, ANOTHER SHORT
WAVE HAS GENERATED SOME SHOWERS AND ISOLATED THUNDERSTORMS OVER
THE FLORIDA STRAITS. THESE ARE MOVING NORTH NORTHEAST. THE SHOWERS
WILL AFFECT THE SOUTHEASTERN PORTION OF THE CWA THIS MORNING. THE
QUESTION IS IF THERE WILL BE ANY THUNDERSTORMS THAT MOVE INTO THE
AREA AS WELL. THERE IS AROUND 1000 JOULES JUST ONSHORE, AROUND
HOMESTEAD AND MIAMI. SO, ALTHOUGH ORIGINAL THINKING WAS THEY WOULD
STAY OFFSHORE, MAY HAVE TO ADD A MENTION OF THUNDERSTORMS FOR THIS
AREA THIS MORNING.
AS FOR LATER TODAY, MODELS INDICATE THE TROUGH, OR REALLY, A
WEAKENING FRONT, WILL MOVE ONSHORE THE GULF COAST LATER THIS
MORNING. MODELS ARE INDICATING IT WILL NOT BE TOO ACTIVE,
CONVECTION WISE WHEN IT DOES. BUT, AS IT PROGRESS ACROSS THE
STATE, ALONG WITH DAYTIME HEATING, CONVECTION MAY BE ABLE TO
INITIATE. THE MODELS DO DIFFER GREATLY WITH HOW MUCH CAPE WILL BE
AVAILABLE. THE GFS KEEPS THE HIGHEST BOUNDARY LAYER CAPE VALUES
WELL OFFSHORE AND ONLY 500-600 JOULES OVER THE ATLANTIC COAST. THE
NAM, ON THE OTHER HAND, HAS 1200 TO 1600 JOULES OVER THE ATLANTIC
COAST, NEAT WEST PALM BEACH, AND DROPS TO 500-700 JOULES NEAR
MIAMI. NOW THE NAM MODEL SOUNDINGS HAVE 1200-1600 JOULES ALL OVER
THE ATLANTIC COAST. THEY DO SHOW A WEAK CAP FURTHER NORTH, BUT IT
IS SO WEAK, NOT THINKING IT WILL BE A REAL INHIBITOR. THERE IS
ALSO A TOUCH OF CIN TO THE NORTH AS WELL, BUT AGAIN, NOTHING THAT
REALLY SHOULD INHIBIT DEVELOPMENT. SO, WHAT WILL INHIBIT THEIR
DEVELOPMENT. WELL, MODELS DO SHOW THAT THE CAPE WILL BE PUSHING
OFF TO THE EAST, AHEAD OF THE TROUGH. SO, WE MAY BE LACKING THE
LIFTING MECHANISM. IT MAY ARRIVE WELL AFTER THE CAPE HAS PUSHED
OFF SHORE. SO, HAVE KEPT CHC POPS AND SLIGHT CHC TSTMS, BUT HAVE
BROADENED THE COVERAGE OF TSTMS THIS AFTERNOON.
BEHIND THE TROUGH TODAY, HIGH PRESSURE WILL BE BUILDING IN FAIRLY
QUICK. THIS WILL BRING QUIET WEATHER BACK TO SOUTH FLORIDA FOR A
FEW DAYS.
FOR FRIDAY AND THE WEEKEND, A LOW PRESSURE SYSTEM WILL DEVELOP
OVER THE WESTERN GULF AND MOVE OVER THE FLORIDA PANHANDLE THURSDAY
NIGHT/FRIDAY MORNING. A COLD FRONT WILL MOVE THROUGH SOUTH FLORIDA
FRIDAY. THIS SYSTEM WILL BRING OUR NEXT CHANCE FOR RAIN AND
POSSIBLY A THUNDERSTORM. MODELS ARE IN PRETTY GOOD AGREEMENT WITH
THE STRENGTH, POSITION, AND TIMING OF THIS SYSTEM. GIVEN THIS,
HAVE A HIGH CHC POP IN THE FORECAST FOR FRIDAY. BEHIND THE FRONT,
HIGH PRESSURE WILL BUILD IN ONCE AGAIN. TEMPERATURES WILL NOT BE
MUCH COOLER, ONLY A FEW DEGREES. THIS HIGH PRESSURE WILL LAST FOR
THE REMAINDER OF THE EXTENDED FORECAST.
MARINE...
WINDS AHEAD OF A WEAK FRONT/TROUGH WILL PICK UP OUT OF THE SOUTH
TO BETWEEN 13 AND 19 KTS OVER THE ATLANTIC WATERS. THEY SHOULD
REMAIN BELOW 10 KTS OVER THE GULF WATERS. THE HIGHER WIND SPEEDS
OVER THE ATLANTIC WATERS HAS PROMPTED A SMALL CRAFT SHOULD
EXERCISE CAUTION STATEMENT FOR THIS AFTERNOON. SEAS TODAY WILL BE
SUBSIDING SOMEWHAT, EVEN WITH THE WINDS, AND ARE EXPECTED TO BE 1
TO 3 FEET BY TOMORROW IN THE ATLANTIC WATERS. THE GULF WATERS WILL
BE AROUND 1 FOOT FOR THE NEXT COUPLE OF DAYS. HIGH PRESSURE WILL
BUILD IN BEGINNING TONIGHT. THIS WILL CAUSE WINDS TO WEAKEN SOME
TONIGHT TO 7-10 KTS OVER THE ATLANTIC AND SHIFT THEM OUT OF THE
NORTH TOMORROW.
FIRE WEATHER...
THE MAIN FIRE WEATHER CONCERN TODAY ARE THE SHIFTING WINDS. AN
APPROACHING FRONT/TROUGH WILL CAUSE WINDS TO PICK UP SOME TODAY TO
10 TO 15 MPH OVER GLADES, HENDRY, AND INTERIOR COLLIER COUNTIES.
THEY WILL BEGIN OUT OF THE SOUTHEAST, BUT TURN THROUGH THE DAY TO
THE SOUTH, THEN SOUTHWEST BY EARLY AFTERNOON. BY THIS EVENING,
THEY WILL BECOME WESTERLY BETWEEN 5 AND 10 MPH. ALONG WITH THIS
WIND SHIFT, WILL BE THE CHANCE FOR SOME RAIN SHOWERS AND A SLIGHT
CHANCE FOR A THUNDERSTORM. THE CHANCES INCREASE AS YOU GO EASTWARD
ACROSS SOUTH FLORIDA. IN THE INTERIOR PORTION OF THE AREA, THE
DIVIDING LINE FOR THE CHANCE OF AND THUNDERSTORMS IS A DIFFICULT
ONE AT BEST. SO, AREAS WEST OF THE FORECASTED AREA, SHOULD REMAIN
AWARE OF THE POSSIBILITY THAT THE FORECAST COULD CHANGE TO INCLUDE
THEM AS THE TROUGH GETS CLOSER. ONE THE OTHER HAND, IT COULD ALSO
BE PUSHED FURTHER EAST. THERE IS JUST GREAT UNCERTAINTY WITH THE
CONVECTIVE DEVELOPMENT TODAY.
BEHIND THE TROUGH, HIGH PRESSURE WILL BUILD IN THROUGH THURSDAY,
BRINGING QUIET WEATHER BACK TO SOUTH FLORIDA.
PREV DISCUSSION... /ISSUED 241 AM EDT MON APR 1 2013/
AVIATION...
ISOLATED SHOWERS WERE MOVING ACROSS THE ATLANTIC WATERS AND NEAR
KFLL AND FXE. ANOTHER AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS
WERE MOVING JUST SOUTH OF THE KEYS. THIS AREA OF SHOWERS AND
STORMS WILL CONTINUE TO MOVE NORTHWARD OVERNIGHT...AND COULD GET
NEAR KTMB AND KMIA IN THE NEXT FEW HOURS IF THEY HOLD TOGETHER. A
SHORTWAVE TROUGH MOVING ACROSS THE EASTERN GULF WAS FORCING
SHOWERS AND THUNDERSTORMS TO DEVELOP WEST OF TAMPA. THE HRRR
KEEPS THIS LINE TOGETHER AND MOVES IT TOWARDS KAPF AROUND 16Z.
OTHER SHOWERS OR STORMS COULD ALSO BEGIN DEVELOPING ON THE EAST
COAST SEA BREEZE AROUND THIS TIME. THE WIND DIRECTION IS ALSO
TRICKY TODAY AS THE BOUNDARY LAYER WINDS SHIFT TO THE SOUTHWEST
AHEAD OF THE TROUGH AND WEAK COLD FRONT. SO THE WINDS MAY SHIFT TO
THE SOUTHWEST FOR A TIME LATE IN THE MORNING BEFORE THE EAST COAST
SEA BREEZE BOUNDARY TRIES TO PUSH THE WINDS BACK TO THE SOUTH OR
SOUTHEAST. BY 00Z...SOUTHWESTERLY FLOW IS EXPECTED TO
PREVAIL...WITH WEST TO NORTHWESTERLY FLOW BEHIND THE SURFACE
TROUGH AFTER 02-04Z. SO FOR THE TAFS...KEPT VCSH FOR NOW...BUT
MAY NEED TO ADD VCTS. MVFR CONDITIONS ARE POSSIBLE NEAR ANY
SHOWERS OR STORMS THAT FORM.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 82 65 81 68 / 50 20 10 -
FORT LAUDERDALE 82 66 82 69 / 50 20 10 -
MIAMI 82 67 83 69 / 50 20 10 -
NAPLES 79 63 79 63 / 20 10 10 -
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
350 PM EDT MON APR 1 2013
...BRIEF DRY PERIOD BEFORE RAIN RETURNS MID WEEK...
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
LATEST SURFACE ANALYSIS SHOWS SEMI PERMANENT SURFACE TROUGH FROM
JUST SOUTH OF ATHENS THROUGH COLUMBUS. ALONG AND SOUTH OF THIS
FEATURE MOISTURE SURFACE CONVERGENCE HAS RESULTED IN SCATTERED TO
BROKEN CU DEVELOPMENT BUT SHOWER ACTIVITY HAS REMAINED OUTSIDE OF
THE FORECAST AREA. FURTHER NORTH...SURFACE FRONT CONTINUES TO SAG
INTO NORTH GA WITH MOISTURE POOLING ALONG ITS LEADING EDGE AS WELL
AND ADDITIONAL CLOUD DEVELOPMENT THE RESULT.
THIS SHOULD REMAIN JUST CLOUDS WITH NO PRECIP FOR THIS EVENING AS
MAIN FOCUS WILL BE ON SOUTHERN TROUGH AND IT AFFECTS ON CENTRAL
GEORGIA. LOOKING AT THE LATEST RAP ANALYSIS OF CAPE IN THIS
VICINITY AND WE SEE 500 J/KG TO 1000 J/KG OF AVAILABLE
ENERGY...SLIGHTLY HIGHER THAN MODEL PROJECTIONS. STILL LOOKING AT
500MN TEMPS IN THE VERY COLD RANGE OF -17C IN THIS AREA SO ANY
SUSTAINED UPDRAFTS WILL BE CAPABLE OF PRODUCING LARGE HAIL.
ACTIVITY WILL SHIFT EAST QUICKLY THIS EVENING WITH CLEARING
CONDITIONS TAKING PLACE. STILL SOME GRADIENT IN PLACE ACROSS THE
AREA WHICH WILL PREVENT OPTIMUM RADIATIONAL COOLING CONDITIONS.
WENT WITH A MAV/MET BLEND FOR THE OVERNIGHT TEMPS WHICH WILL BE
TRICKY TO THE SOUTH BASED ON HOW FAST CLOUDS CLEAR.
SURFACE FRONT LOOKS TO STALL ACROSS NORTH GEORGIA TUESDAY AND
IMPULSES OF ENERGY BEGIN TO ROUND PERIPHERY OF EAST COAST TROUGH.
THIS SHOULD ALLOW A FEW LIGHT SHOWERS TO DEVELOP ACROSS EXTREME
NORTH GEORGIA AND HAVE INCLUDED IN THIS GRID PACKAGE. AS HIGH
BRIDGES ACROSS THROUGH TUESDAY NIGHT...MAY SEE FRONT SAG FURTHER
SOUTH AND TAKE 20 POPS ALONG WITH IT INTO THE REMAINDER OF NORTH
GEORGIA.
DEESE
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
MAIN CONCERN FOR THE EXTENDED REMAINS THE SYSTEM MOVING THROUGH
THE STATE ON WEDNESDAY INTO THE END OF THE WORK WEEK.
DISCREPANCIES STILL REMAIN BETWEEN THE EURO AND GFS AS FAR AS
TIMING OF THE SYSTEM LEAVING THE CWA. THE 12Z MODELS ARE
STRIKINGLY SIMILAR TO THEIR OOZ COUNTERPARTS. AS SUCH...WAS NOT
ABLE TO NAIL DOWN AN ACCURATE END TO THE RAIN THIS WEEK. ACCORDING
TO HPC MODEL DISCUSSIONS THE EURO IS AN OUTLIER...MOVING THE
SYSTEM FURTHER SOUTH AND IS SLOWER. THAT SAID THEY DECIDED TO WITH
A BLEND BETWEEN THE 00Z EURO AND THE 06Z GEFS. WITH THIS MUCH
UNCERTAINTY DECIDED TO ONLY CHANGE THE COVERAGE OF THUNDER ON
WEDNESDAY AND LEAVE THE REST OF THE FORECAST ALONE. DID LOWER
TEMPS ON THURSDAY AS A PSEUDO WEDGE BUILDS IN. CLOUDS AND RAIN IN
ASSOCIATION WITH THIS WEDGE SHOULD HELP TO KEEP TEMPS LOW. HAVE
INCLUDED PREVIOUS EXTENDED BELOW/
ARG
&&
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... POTENTIAL FOR A HEAVY
RAIN/SEVERE WEATHER EVENT SETTING UP IN THE THURSDAY TO THURSDAY
NIGHT TIME FRAME. MODELS SIMILAR WITH SPREADING DEEPER MOISTURE
INTO THE AREA LATE WEDNESDAY BUT THE MAIN PRECIP PERIOD LOOKS TO
BE WEDNESDAY NIGHT THRU THURSDAY NIGHT. AN OVERRUNNING PATTERN
WILL SET LATE WEDNESDAY/WEDNESDAY NIGHT WITH MODELS DEVELOPING A
WARM FRONT ALONG THE GULF COAST. SURFACE LOW PRESSURE DEVELOPS
OVER THE WESTERN GULF AND MOVES TO THE WESTERN FL PANHANDLE LATE
THURSDAY AND THEN ACROSS CENTRAL TO S GA THURSDAY NIGHT/FRIDAY.
THE GFS IS FASTER WITH THIS PROGRESSION THAN THE EUROPEAN. THIS
TRACK COULD MOVE THE WARM FRONT INTO THE SE CWA AND GIVE POTENTIAL
FOR SEVERE THUNDERSTORMS MAINLY THURSDAY NIGHT. IT WILL ALSO GIVE
POTENTIAL FOR HEAVY RAIN ACROSS A LARGE PORTION OF EAST GEORGIA
AND MODELS IN GENERAL ARE LESS GUN-OH WITH PRECIP AMOUNTS WITH A
LARGE AREA OF 1-2 INCHES FORECAST. THE UPPER TROUGH MOVES ACROSS
THE AREA ON FRIDAY AND THE GFS IS FASTER WITH THIS PROGRESSION
THAN THE EUROPEAN. THE AIRMASS DRIES OUT FOR SATURDAY AND MOSTLY
LIKELY SUNDAY WITH THE EUROPEAN INDICATING SOME MOISTURE
ASSOCIATED WITH A SHORT WAVE ON SUNDAY...MOST SO FOR N GA. FOR NOW
WILL KEEP THINGS DRY AND MONITOR THE PROGRESSION. A SHORT WAVE
RIDGE BUILDS FOR MONDAY WITH THE EUROPEAN CONTINUING TO SHOW MORE
MOISTURE SKIRTING OVER N GA THAN THE GFS.
BDL
AVIATION...
18Z UPDATE...
VFR FORECAST IN STORE AS MAIN CLOUD SHIELD HAS SLIPPED TO THE
SOUTH OF THE TERMINALS. WILL BE WATCHING SECONDARY AREA OF CLOUDS
DEVELOPING OVER EXTREME NORTH GA IN ENHANCED MOISTURE ZONE BUT
JUST PLAYING AS FEW050 FOR NOW. OTHERWISE...STILL UNCERTAINTY
WITH WIND SHIFT POTENTIAL MID MORNING TUESDAY WITH NW VS NE STILL
IN QUESTION FOR ATL. WENT WITH CONSENSUS OF NW FOR NOW WHICH
AGREES WITH PARTNERS AND CONSENSUS.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM ON WIND SHIFT.
HIGH ON REMAINING ELEMENTS.
DEESE
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 42 69 41 64 / 10 10 20 20
ATLANTA 47 67 44 64 / 5 5 20 20
BLAIRSVILLE 37 58 35 63 / 10 10 20 20
CARTERSVILLE 41 65 40 64 / 5 10 20 20
COLUMBUS 51 75 50 70 / 5 5 5 30
GAINESVILLE 44 65 43 61 / 10 10 20 20
MACON 45 75 44 69 / 5 5 5 30
ROME 38 65 38 64 / 5 10 20 20
PEACHTREE CITY 40 70 42 65 / 5 5 20 30
VIDALIA 55 76 51 74 / 20 0 5 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DEESE
LONG TERM....ARG
AVIATION...DEESE
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
126 AM EDT MON APR 1 2013
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL OVERNIGHT. A COLD FRONT WILL
MOVE ACROSS THE AREA LATE MONDAY AFTERNOON INTO MONDAY
EVENING...FOLLOWED BY HIGH PRESSURE BUILDING FROM THE NORTH
THROUGH THE MIDDLE OF THE WEEK. A LOW PRESSURE SYSTEM WILL THEN
PASS ALONG THE SOUTHEAST COAST LATE IN THE WEEK INTO EARLY NEXT
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPSTREAM PCPN TRENDS AND LATEST RAP MODEL DATA HAVE TRENDED A BIT
SLOWER WITH RAIN REACHING THE I-95 CORRIDOR THROUGH 6 AM. WE KNOCKED
BACK POPS ALONG AND E OF I-95 DOWN ON THE MIDNIGHT UPDATE. TEMPS
WILL BE NO LOWER THAN THE UPPER 50S AND LOWER 60S...MAKING THEM
THE WARMEST NIGHT TIME LOWS IN MANY LOCALES SINCE FEBRUARY 11TH.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/...
MONDAY...A COLD FRONT WILL BE SITUATED ACROSS THE SOUTH CAROLINA
MIDLANDS AND EAST-CENTRAL GEORGIA TO START THE DAY...WITH AN AXIS OF
DEEP MOISTURE IN PLACE OVER THE AREA AHEAD OF THE FRONT WHERE
PRECIPITABLE WATER VALUES WILL PEAK AROUND 1.3 TO 1.4 INCHES. THE
DEEP MOISTURE COMBINED WITH FORCING FROM THE RIGHT ENTRANCE REGION
OF A WEAKENING H25 JET WILL SUPPORT NUMEROUS SHOWERS ACROSS THE AREA
IN THE MORNING. THE SHOWERS WILL THEN BEGIN TO TAPER OFF FROM THE
WEST DURING THE AFTERNOON AS THE FRONT SHIFTS ACROSS THE AREA AND
OFFSHORE BY LATE IN THE DAY. SOME THUNDERSTORMS ARE POSSIBLE...A FEW
OF WHICH COULD BE STRONG/SEVERE AT TIMES WITH SURFACE BASED CAPE
VALUES OF 800-1000 J/KG AND...LI VALUES OF -3C TO -5C AND MID LEVEL
LAPSE RATES OF 6-7 C/KM. WET BULB ZERO HEIGHTS POSSIBLY REACHING AS
LOW AS 8-9K FT WILL SUPPORT A HAIL THREAT...WITH DAMAGING WINDS ALSO
POSSIBLE. THE GREATEST POTENTIAL FOR ANY STRONG/SEVERE THUNDERSTORMS
APPEARS TO BE ACROSS SOUTHEAST GEORGIA...BUT GIVEN UNCERTAINTY IN
THE EXTENT OF DIURNAL HEATING THAT CAN TAKE PLACE DUE TO EXTENSIVE
CLOUD COVER AND PRECIPITATION...WILL KEEP MENTION OUT OF THE
HAZARDOUS WEATHER OUTLOOK FOR NOW. DESPITE THE EXTENSIVE CLOUD COVER
INITIALLY...A GOOD SOUTHWEST FLOW AND WEAK COMPRESSIONAL HEATING
AHEAD OF THE FRONT FOLLOWED BY A WARM WESTERLY FLOW IN ITS WAKE
SHOULD ALLOW TEMPERATURES TO REACH HIGHS IN THE MID 70S ACROSS THE
AREA AWAY FROM THE COOLER IMMEDIATE COAST.
MONDAY NIGHT...A SECONDARY COLD FRONT WILL SWING THROUGH THE AREA
DURING THE EVENING...WITH A DEVELOPING NORTHWEST/NORTH FLOW
ADVECTING A DRIER AIRMASS INTO THE REGION. ANY LINGERING ISOLATED
SHOWERS EARLY IN THE EVENING WILL QUICKLY COME TO AN END...WITH
MOSTLY CLEAR TO PARTLY CLOUDY SKIES EXPECTED THROUGH THE REMAINDER
OF THE NIGHT. LOW TEMPERATURES WILL BE IN THE UPPER 40S TO LOWER
50S.
TUESDAY AND TUESDAY NIGHT...A WEAK BUBBLE HIGH WILL SETTLE OVER THE
CAROLINAS WITH A NEARLY ZONAL FLOW IN PLACE ALOFT. RAIN-FREE
CONDITIONS AND PARTLY CLOUDY SKIES ARE EXPECTED. A WEAK DOWNSLOPE
FLOW ALOFT SHOULD HELP TEMPERATURES REACHES HIGH ON TUESDAY IN THE
LOWER TO MID 70S ACROSS MUCH OF THE AREA AWAY FROM THE IMMEDIATE
COAST...WITH SOME UPPER 70S EVEN POSSIBLE SOUTH OF THE I-16
CORRIDOR. LOWS TUESDAY NIGHT WILL BE IN THE UPPER 40S TO LOWER 50S
ONCE AGAIN.
WEDNESDAY...IT APPEARS THAT A WEAK BACKDOOR COLD FRONT DROPS THROUGH
THE AREA IN RESPONSE TO A STRONGER WEDGE OF HIGH PRESSURE BUILDING
FROM THE NORTH. THERE IS SOME MODEL DISAGREEMENT WITH RESPECT TO THE
EXTENT OF MOISTURE ACCOMPANYING THE BUILDING WEDGE...WITH THE NAM
MUCH MORE AGGRESSIVE THAN THE OTHER MODELS. WHILE THE CONSENSUS IS
FOR NOT MUCH IN THE WAY OF RAINFALL STILL FEEL THAN AN ISOLATED
SHOWER CANNOT BE RULED OUT AND THE FORECAST INDICATES A SLIGHT
CHANCE OF RAIN AS A RESULT. THE TEMPERATURE FORECAST IS ALSO TRICKY
AND THERE WILL LIKELY BE A LARGE GRADIENT ACROSS THE AREA...BUT FEEL
THE SAFEST BET IS TO FORECAST HIGHS RANGING FROM THE LOWER AND MID
60S IN SOUTHEAST SOUTH CAROLINA TO THE UPPER 60S AND LOWER 70S IN
SOUTHEAST GEORGIA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
WEDNESDAY NIGHT THROUGH FRIDAY...WE WILL SEE A TRANSITION TO A MUCH
WETTER PATTERN AS A SFC LOW DEEPENS OVER THE NORTHERN GULF WHILE AN
H5 SHORTWAVE DIGS OVER THE DEEP SOUTH. PRECIP CHANCES WILL INCREASE
IN SOUTHEAST GEORGIA..THEN INTO SOUTHEAST SOUTH CAROLINA AS AN
EASTWARD EXTENDING WARM FRONT DEVELOPS WEDNESDAY NIGHT AND BECOMES
POSITIONED ALONG THE SOUTHEAST COAST THURSDAY. THE AMOUNT OF
RAINFALL ASSOCIATED WITH THIS SYSTEM WILL BE HIGHLY DEPENDENT ON THE
POSITION OF THE WARM FRONT AND THE TRACK OF THE SFC LOW FROM THE
NORTHERN GULF OF MEXICO TO THE SOUTHEAST COAST.
AT THIS TIME...HIGH PRESSURE LOOKS TO MAINTAIN SOME HOLD OVER THE
FORECAST AREA...THUS FORCING A MORE SOUTHERN TRACK OF THE SFC LOW
OVER NORTHERN FLORIDA AND THEN ALONG THE SOUTHEAST COAST. WITH THIS
TRACK IN MIND...HAVE INTRODUCED LIKELY POPS OVER SOUTHEAST GEORGIA
AND CHANCE POPS OVER SOUTHEAST SOUTH CAROLINA WEDNESDAY NIGHT...WITH
LIKELY POPS ACROSS THE AREA THURSDAY AND THURSDAY NIGHT BEFORE THE
SFC LOW RAPIDLY DEEPENS AND SHIFTS TO THE NORTHEAST FRIDAY. SHOULD A
MORE NORTHERN TRACK TAKE PLACE...A CHANCE OF THUNDERSTORMS WILL
LIKELY NEED TO BE INTRODUCED OVER THE AREA. OVERALL TEMPS SHOULD
REMAIN COOL ON THURSDAY WITH HIGH PRESSURE MAINTAINING A HOLD.
OVERALL TEMPS SHOULD RANGE BETWEEN THE UPPER 50S NORTH...TO LOW/MID
60S SOUTH. BY FRIDAY...TEMPS SHOULD MODIFY A FEW DEGREES WITH THE
WARM FRONT ALONG THE COAST. OVERNIGHT LOWS SHOULD REACH THE LOW/MID
40S WEDNESDAY NIGHT AND UPPER 40S TO LOWER 50S THURSDAY AND FRIDAY
NIGHT.
SATURDAY AND SUNDAY...A DRY AND WARMING TREND IS ANTICIPATED FOR THE
SECOND HALF OF THE WEEKEND AS MID LVL RIDGING GRADUALLY EXPANDS INTO
THE SOUTHEAST. WITH LITTLE CLOUD ANTICIPATED...OVERALL TEMPS SHOULD
REACH THE UPPER 60S TO LOWER 70S SATURDAY AND LOWER 70S OVER MOST
LOCATIONS ON SUNDAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
OVERNIGHT WE HAVE MAINTAINED VFR WITH DRY WEATHER AT KSAV AND KCHS.
LATEST MODEL GUIDANCE SUGGESTS THE BEST TIMING FOR SCATTERED SHOWERS
WILL BE FROM 8 AM TO ABOUT NOON TODAY. TSTMS ARE POSSIBLE BUT TOO
EARLY/UNCERTAIN TO INTRO TSRA/CB AT THIS TIME. THIS AFTERNOON...WEST
WINDS WILL DIMINISH RAIN CHANCES AND MVFR CIG POTENTIAL BUT WILL
HAVE TO WATCH FOR ISOLATED TSTMS AHEAD OF THE COLD FRONT. AFTER
SUNSET...VFR CONDITIONS TO ALSO PREVAIL.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS SHOULD PREVAIL THROUGH
WEDNESDAY. MVFR OR LOWER CIGS/VSBYS ARE POSSIBLE WEDNESDAY NIGHT
THROUGH FRIDAY MORNING DUE TO RAIN/SHOWERS ASSOCIATED WITH A SFC
LOW TRACKING OVER NORTHERN FLORIDA AND THEN ALONG THE SOUTHEAST
COAST.
&&
.MARINE...
OVERNIGHT...THE COASTAL WATERS WILL BE SITUATED UNDER THE NW
FRINGES OF ATLANTIC RIDGING...WITH AN UPSTREAM COLD FRONT OVER THE
SE UNITED STATES. THE PRESSURE GRADIENT BETWEEN THESE TWO SYNOPTIC
FEATURES WILL BE TIGHT ENOUGH WHERE SOUTH AND SW WINDS WILL REMAIN
ELEVATED. SPEEDS WILL BE A SOLID 15 OR 20 KT OVER THE OCEAN...WITH
FREQUENT GUSTS OF 25 KT ACROSS THE OUTER GA WATERS. IT IS THERE
WHERE WE HAVE MAINTAINED THE SCA. IN CHARLESTON HARBOR WINDS WILL
GENERALLY HOLD UNDER 15 KT. DUE TO THESE WINDS AND A SOMEWHAT
FAVORABLE FETCH...SEAS WILL BE AS HIGH AS 3-5 FT WITHIN 20 NM OF THE
SHORE...BUT 4-6 FT ACROSS THE GA WATERS 20-60 NM OUT.
MONDAY THROUGH FRIDAY...SOUTHWEST FLOW WILL PREVAIL AHEAD OF AN
APPROACHING COLD FRONT MONDAY...WITH A TIGHT SURFACE PRESSURE
GRADIENT SUPPORTING MARGINAL SMALL CRAFT ADVISORY CONDITIONS OVER
PORTIONS OF THE OUTER GEORGIA WATERS DURING THE MORNING. CONDITIONS
WILL IMPROVE FOLLOWING THE PASSAGE OF A COLD FRONT MONDAY EVENING AS
WINDS SHIFT OFFSHORE. BUILDING HIGH PRESSURE WILL ALLOW A NORTHEAST
SURGE TO DEVELOP LATE MONDAY NIGHT INTO TUESDAY...WITH WINDS PEAKING
AROUND 15-20 KT. WEAK HIGH PRESSURE OVER THE CAROLINAS WILL THEN
KEEP CONDITIONS RATHER BENIGN OVER THE WATERS THROUGH TUESDAY NIGHT.
A WEAK BACK DOOR COLD FRONT WILL DROP THROUGH AS STRONGER HIGH
PRESSURE BUILDS FROM THE NORTH ON WEDNESDAY...CAUSING WINDS/SEAS TO
BEGIN DETERIORATING LATE WEDNESDAY AND WEDNESDAY NIGHT. SMALL CRAFT
ADVISORY CONDITIONS ARE THEN LIKELY LATE WEEK AS CONDITIONS
DETERIORATE FURTHER DUE TO AN ENHANCED PRESSURE GRADIENT BETWEEN
HIGH PRESSURE OVER THE WESTERN ATLANTIC AND LOW PRESSURE OVER THE
NORTHERN GULF ON THURSDAY FOLLOWED BY THE PASSAGE OF A COASTAL LOW
ALONG THE SOUTHEAST COAST THURSDAY NIGHT INTO FRIDAY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR AMZ374.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...JAQ
LONG TERM...DPB/JAQ
AVIATION...
MARINE...
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
635 AM EDT MON APR 1 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 353 AM EDT MON APR 1 2013
A WEAK UPPER WAVE WILL MOVE THROUGH THE AREA THIS MORNING BUT HIGH
PRESSURE WILL BUILD IN THIS AFTERNOON AND KEEP DRY WEATHER ACROSS
THE AREA THROUGH SATURDAY. SATURDAY NIGHT A LOW PRESSURE SYSTEM WILL
APPROACH AND BRING CHANCES FOR RAIN. TEMPERATURES WILL BE WELL BELOW
NORMAL TODAY THROUGH TUESDAY NIGHT AND THEN REBOUND TO ABOVE NORMAL
BY THE WEEKEND.
&&
.NEAR TERM /TODAY/...
ISSUED AT 353 AM EDT MON APR 1 2013
FORECAST FOCUS IS ON NEED FOR ANY POPS FROM EARLY TO MID MORNING.
UPPER WAVE IS CURRENTLY MOVING SOUTHEAST THROUGH SOUTHERN IOWA AND
WESTERN ILLINOIS. RADAR MOSAIC SHOWS WEAK ECHOES OVER WESTERN AND
CENTRAL ILLINOIS AS WELL AS SOME ENTERING WESTERN INDIANA BUT
SURFACE OBS SHOW NO PRECIP AT THE GROUND. GFS AND NAM ARE BOTH DRY
AND GUIDANCE IS AS WELL. RAPID REFRESH AND RAP SHOW SOME DEVELOPMENT
OCCURRING ACROSS THE SOUTHERN COUNTIES AROUND 11-12Z AND MOVING
THROUGH BY 15Z. WITH BOTH OF THE RAPID UPDATE MODELS SHOWING THIS
DEVELOPMENT WILL GO AHEAD AND LEAVE A SLIGHT CHANCE FOR RAIN AND
SNOW MOVING ACROSS THE SOUTH FROM 11 TO 15Z AND DRY FROM 15Z ON.
SHOULD NOT AMOUNT TO ANYTHING. WILL DROP ANY MENTION OF FLURRIES
ELSEWHERE.
CLOUDS SHOULD SCATTER OUT AS THE DAY GOES ON. WILL SEE COLD
ADVECTION THROUGHOUT THE DAY SO TEMPERATURES SHOULD STRUGGLE TO WARM
AND THUS WENT WITH A CONSENSUS OF RAW MODEL NUMBERS SINCE
CLIMATOLOGY COULD BIAS THINGS UP.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 353 AM EDT MON APR 1 2013
HIGH PRESSURE WILL DOMINATE THE WEATHER IN THE SHORT TERM. MODELS
ARE IN GOOD AGREEMENT AND WILL USE A CONSENSUS. WITH MOSTLY CLEAR TO
CLEAR SKIES THROUGHOUT THE SHORT TERM STUCK CLOSE TO COOLER GUIDANCE
NUMBERS AT NIGHT OF LOW TO MIDDLE 20S. FOR HIGHS TUESDAY AGAIN THOUGHT
GUIDANCE WAS BIASED A BIT WARM FROM CLIMATOLOGY SO STUCK WITH A RAW
MODEL CONSENSUS IN THE LOW TO MID 40S...BUT BY WEDNESDAY THE AIR
MASS SHOULD BE REBOUNDING UNDER WARM ADVECTION AND A COMPLETE
CONSENSUS LOOKED GOOD IN THE UPPER 40S TO LOW 50S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 324 AM EDT MON APR 1 2013
A LARGE AREA OF HIGH PRESSURE WILL BE MOVING AWAY TO THE EAST ON
THURSDAY WITH A SPLIT FLOW PATTERN ALOFT AS A WEAK FRONT
APPROACHES FROM THE NORTHWEST AND AN UPPER LOW TRACKS ACROSS THE
SOUTHERN PLAINS. MODEL CONSENSUS HAS BEEN TRACKING THE UPPER WAVE
FURTHER NORTH OVER THE LAST COUPLE DAYS AND BRINGS THE NORTHERN
FRINGES OF THE RAINFALL ASSOCIATED WITH THE UPPER LOW INTO THE
OHIO RIVER VALLEY THURSDAY NIGHT. CONSIDERING THE NORTHERLY LOW
LEVEL FLOW...PRESENCE OF DRIER AIR OVER THE REGION AND THE BULK OF
THE DEEPER FORCING REMAINING TO THE SOUTH OF THE FORECAST
AREA...WILL CONTINUE TO KEEP A DRY FORECAST GOING THURSDAY NIGHT.
DO ANTICIPATE AN INCREASE IN CLOUDS OVER THE SOUTHERN COUNTIES
THURSDAY NIGHT AND EARLY FRIDAY AS THE UPPER WAVE PASSES TO THE
SOUTH. THE AFOREMENTIONED WEAK FRONT APPROACHING FROM THE
NORTHWEST SET TO WASH OUT ACROSS THE LOWER GREAT LAKES THURSDAY
NIGHT.
AS THE UPPER WAVE WEAKENS AND SHIFTS INTO THE SOUTHEAST STATES BY
FRIDAY AFTERNOON...HIGH PRESSURE WILL REESTABLISH ACROSS THE OHIO
VALLEY WITH AN EXPANSION OF RIDGING ALOFT BRINGING WARMER AIR INTO
THE REGION. LOW LEVEL THERMALS SUPPORT HIGH TEMPS RISING INTO THE 60S
BY SATURDAY. FORECAST MORE MUDDLED FOR THE SECOND HALF OF THE
WEEKEND AS A DEVELOPING WARM FRONT SETS UP OVER THE LOWER GREAT
LAKES AND A SURFACE WAVE TRACKS ALONG THE BOUNDARY ON SUNDAY. WILL
CARRY LOW CHANCE POPS SATURDAY NIGHT INTO SUNDAY AS THE SURFACE
WAVE PASSES THROUGH THE AREA. APPEARS THE BOUNDARY MAY SETTLE
FURTHER SOUTH NEAR THE OHIO RIVER BY LATE SUNDAY WITH THE PASSAGE
OF THE LOW...BEFORE THE BOUNDARY RETURNS BACK NORTH EARLY NEXT
WEEK. LOW LEVEL THERMALS STILL SUGGESTIVE OF HIGHS IN THE 60S FOR
SUNDAY EVEN AS THE BOUNDARY SHIFTS SOUTH...WITH POSSIBILITY FOR
WARMER DAYTIME HIGHS EARLY NEXT WEEK ONCE THE FRONT LIFTS BACK
NORTH.
&&
.AVIATION /DISCUSSION FOR 011200Z TAF ISSUANCE/...
ISSUED AT 635 AM EDT MON APR 1 2013
VFR CONDITIONS ANTICIPATED THROUGHOUT THE FORECAST PERIOD.
MID LEVEL CLOUDS PRESENT EARLY THIS MORNING AS AN UPPER WAVE
MOVES THROUGH THE REGION. AREA OF RETURNS NOTED FROM WESTERN
INDIANA BACK INTO ILLINOIS BUT APPEARS LITTLE IF ANY OF THIS IS
REACHING THE GROUND BASED ON CURRENT OBS. MAY SEE A FEW FLURRIES
AT KBMG/KHUF/KIND THROUGH 15Z BUT EXPECT NO IMPACTS TO TERMINALS.
MODEL SOUNDINGS SHOW FAVORABLE CONDITIONS FOR CU DEVELOPMENT THIS
AFTERNOON WITH CONVECTIVE TEMPS IN THE UPPER 30S AND INCREASING COLD
ADVECTION. LIKELY TO SEE GUSTS TO AROUND 20KTS AS WELL THROUGH THE
AFTERNOON WITH GOOD LOW LEVEL MIXING.
AS HIGH PRESSURE SPREADS INCREASINGLY DRIER AIR INTO THE FORECAST
AREA...WILL SEE A GRADUAL DECREASE IN CU BY LATE DAY WITH SKIES
BECOMING MOSTLY CLEAR TONIGHT.NORTHWEST WINDS WILL BECOME LIGHT
THIS EVENING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....RYAN
AVIATION...RYAN
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
415 AM EDT MON APR 1 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 353 AM EDT MON APR 1 2013
A WEAK UPPER WAVE WILL MOVE THROUGH THE AREA THIS MORNING BUT HIGH
PRESSURE WILL BUILD IN THIS AFTERNOON AND KEEP DRY WEATHER ACROSS
THE AREA THROUGH SATURDAY. SATURDAY NIGHT A LOW PRESSURE SYSTEM WILL
APPROACH AND BRING CHANCES FOR RAIN. TEMPERATURES WILL BE WELL BELOW
NORMAL TODAY THROUGH TUESDAY NIGHT AND THEN REBOUND TO ABOVE NORMAL
BY THE WEEKEND.
&&
.NEAR TERM /TODAY/...
ISSUED AT 353 AM EDT MON APR 1 2013
FORECAST FOCUS IS ON NEED FOR ANY POPS FROM EARLY TO MID MORNING.
UPPER WAVE IS CURRENTLY MOVING SOUTHEAST THROUGH SOUTHERN IOWA AND
WESTERN ILLINOIS. RADAR MOSAIC SHOWS WEAK ECHOES OVER WESTERN AND
CENTRAL ILLINOIS AS WELL AS SOME ENTERING WESTERN INDIANA BUT
SURFACE OBS SHOW NO PRECIP AT THE GROUND. GFS AND NAM ARE BOTH DRY
AND GUIDANCE IS AS WELL. RAPID REFRESH AND RAP SHOW SOME DEVELOPMENT
OCCURRING ACROSS THE SOUTHERN COUNTIES AROUND 11-12Z AND MOVING
THROUGH BY 15Z. WITH BOTH OF THE RAPID UPDATE MODELS SHOWING THIS
DEVELOPMENT WILL GO AHEAD AND LEAVE A SLIGHT CHANCE FOR RAIN AND
SNOW MOVING ACROSS THE SOUTH FROM 11 TO 15Z AND DRY FROM 15Z ON.
SHOULD NOT AMOUNT TO ANYTHING. WILL DROP ANY MENTION OF FLURRIES
ELSEWHERE.
CLOUDS SHOULD SCATTER OUT AS THE DAY GOES ON. WILL SEE COLD
ADVECTION THROUGHOUT THE DAY SO TEMPERATURES SHOULD STRUGGLE TO WARM
AND THUS WENT WITH A CONSENSUS OF RAW MODEL NUMBERS SINCE
CLIMATOLOGY COULD BIAS THINGS UP.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 353 AM EDT MON APR 1 2013
HIGH PRESSURE WILL DOMINATE THE WEATHER IN THE SHORT TERM. MODELS
ARE IN GOOD AGREEMENT AND WILL USE A CONSENSUS. WITH MOSTLY CLEAR TO
CLEAR SKIES THROUGHOUT THE SHORT TERM STUCK CLOSE TO COOLER GUIDANCE
NUMBERS AT NIGHT OF LOW TO MIDDLE 20S. FOR HIGHS TUESDAY AGAIN THOUGHT
GUIDANCE WAS BIASED A BIT WARM FROM CLIMATOLOGY SO STUCK WITH A RAW
MODEL CONSENSUS IN THE LOW TO MID 40S...BUT BY WEDNESDAY THE AIR
MASS SHOULD BE REBOUNDING UNDER WARM ADVECTION AND A COMPLETE
CONSENSUS LOOKED GOOD IN THE UPPER 40S TO LOW 50S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 324 AM EDT MON APR 1 2013
A LARGE AREA OF HIGH PRESSURE WILL BE MOVING AWAY TO THE EAST ON
THURSDAY WITH A SPLIT FLOW PATTERN ALOFT AS A WEAK FRONT
APPROACHES FROM THE NORTHWEST AND AN UPPER LOW TRACKS ACROSS THE
SOUTHERN PLAINS. MODEL CONSENSUS HAS BEEN TRACKING THE UPPER WAVE
FURTHER NORTH OVER THE LAST COUPLE DAYS AND BRINGS THE NORTHERN
FRINGES OF THE RAINFALL ASSOCIATED WITH THE UPPER LOW INTO THE
OHIO RIVER VALLEY THURSDAY NIGHT. CONSIDERING THE NORTHERLY LOW
LEVEL FLOW...PRESENCE OF DRIER AIR OVER THE REGION AND THE BULK OF
THE DEEPER FORCING REMAINING TO THE SOUTH OF THE FORECAST
AREA...WILL CONTINUE TO KEEP A DRY FORECAST GOING THURSDAY NIGHT.
DO ANTICIPATE AN INCREASE IN CLOUDS OVER THE SOUTHERN COUNTIES
THURSDAY NIGHT AND EARLY FRIDAY AS THE UPPER WAVE PASSES TO THE
SOUTH. THE AFOREMENTIONED WEAK FRONT APPROACHING FROM THE
NORTHWEST SET TO WASH OUT ACROSS THE LOWER GREAT LAKES THURSDAY
NIGHT.
AS THE UPPER WAVE WEAKENS AND SHIFTS INTO THE SOUTHEAST STATES BY
FRIDAY AFTERNOON...HIGH PRESSURE WILL REESTABLISH ACROSS THE OHIO
VALLEY WITH AN EXPANSION OF RIDGING ALOFT BRINGING WARMER AIR INTO
THE REGION. LOW LEVEL THERMALS SUPPORT HIGH TEMPS RISING INTO THE 60S
BY SATURDAY. FORECAST MORE MUDDLED FOR THE SECOND HALF OF THE
WEEKEND AS A DEVELOPING WARM FRONT SETS UP OVER THE LOWER GREAT
LAKES AND A SURFACE WAVE TRACKS ALONG THE BOUNDARY ON SUNDAY. WILL
CARRY LOW CHANCE POPS SATURDAY NIGHT INTO SUNDAY AS THE SURFACE
WAVE PASSES THROUGH THE AREA. APPEARS THE BOUNDARY MAY SETTLE
FURTHER SOUTH NEAR THE OHIO RIVER BY LATE SUNDAY WITH THE PASSAGE
OF THE LOW...BEFORE THE BOUNDARY RETURNS BACK NORTH EARLY NEXT
WEEK. LOW LEVEL THERMALS STILL SUGGESTIVE OF HIGHS IN THE 60S FOR
SUNDAY EVEN AS THE BOUNDARY SHIFTS SOUTH...WITH POSSIBILITY FOR
WARMER DAYTIME HIGHS EARLY NEXT WEEK ONCE THE FRONT LIFTS BACK
NORTH.
&&
.AVIATION /DISCUSSION FOR THE 010900Z TAF UPDATE/...
ISSUED AT 415 AM EDT MON APR 1 2013
MID LEVEL CLOUDS EXPANDING BACK ACROSS THE TERMINALS EARLY THIS
MORNING AS THE UPPER TROUGH SHARPENS OVER THE REGION. TWEAKED CLOUDS
AND WIND SPEEDS BASED ON CURRENT OBS WITH EXPECTATION OF SOME GUSTS
APPROACHING 20KTS THROUGH THE MORNING. AREA OF SCATTERED LIGHT SNOW
SHOWERS/FLURRIES OVER NORTHEAST MISSOURI AND WESTERN ILLINOIS WILL
MOVE EAST TOWARDS THE REGION BY DAYBREAK. AT THIS POINT HOWEVER...
STILL APPEARS THIS AREA OF PRECIP WILL CONTINUE TO WEAKEN WITH
POSSIBILITY OF JUST A FEW FLURRIES AT KBMG/KHUF/KIND IN THE 12-15Z
PERIOD. WILL MAINTAIN NO PRECIP MENTION IN TERMINALS AT THIS TIME.
06Z DISCUSSION FOLLOWS.
VFR THROUGH THE PERIOD.
SCT TO BKN MID CLOUD LIKELY THE ONLY SKY COVER THROUGH THE NIGHT.
WINDS WILL ONCE AGAIN GUST TOMORROW TO NEAR 20KT...AND DIURNAL
CUMULUS WILL FORM AROUND 5KFT.
NO VISIBILITY ISSUES ANTICIPATED THROUGH THE PERIOD.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....RYAN
AVIATION...NIELD/RYAN
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
400 AM EDT MON APR 1 2013
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 353 AM EDT MON APR 1 2013
A WEAK UPPER WAVE WILL MOVE THROUGH THE AREA THIS MORNING BUT HIGH
PRESSURE WILL BUILD IN THIS AFTERNOON AND KEEP DRY WEATHER ACROSS
THE AREA THROUGH SATURDAY. SATURDAY NIGHT A LOW PRESSURE SYSTEM WILL
APPROACH AND BRING CHANCES FOR RAIN. TEMPERATURES WILL BE WELL BELOW
NORMAL TODAY THROUGH TUESDAY NIGHT AND THEN REBOUND TO ABOVE NORMAL
BY THE WEEKEND.
&&
.NEAR TERM /TODAY/...
ISSUED AT 353 AM EDT MON APR 1 2013
FORECAST FOCUS IS ON NEED FOR ANY POPS FROM EARLY TO MID MORNING.
UPPER WAVE IS CURRENTLY MOVING SOUTHEAST THROUGH SOUTHERN IOWA AND
WESTERN ILLINOIS. RADAR MOSAIC SHOWS WEAK ECHOES OVER WESTERN AND
CENTRAL ILLINOIS AS WELL AS SOME ENTERING WESTERN INDIANA BUT
SURFACE OBS SHOW NO PRECIP AT THE GROUND. GFS AND NAM ARE BOTH DRY
AND GUIDANCE IS AS WELL. RAPID REFRESH AND RAP SHOW SOME DEVELOPMENT
OCCURRING ACROSS THE SOUTHERN COUNTIES AROUND 11-12Z AND MOVING
THROUGH BY 15Z. WITH BOTH OF THE RAPID UPDATE MODELS SHOWING THIS
DEVELOPMENT WILL GO AHEAD AND LEAVE A SLIGHT CHANCE FOR RAIN AND
SNOW MOVING ACROSS THE SOUTH FROM 11 TO 15Z AND DRY FROM 15Z ON.
SHOULD NOT AMOUNT TO ANYTHING. WILL DROP ANY MENTION OF FLURRIES
ELSEWHERE.
CLOUDS SHOULD SCATTER OUT AS THE DAY GOES ON. WILL SEE COLD
ADVECTION THROUGHOUT THE DAY SO TEMPERATURES SHOULD STRUGGLE TO WARM
AND THUS WENT WITH A CONSENSUS OF RAW MODEL NUMBERS SINCE
CLIMATOLOGY COULD BIAS THINGS UP.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 353 AM EDT MON APR 1 2013
HIGH PRESSURE WILL DOMINATE THE WEATHER IN THE SHORT TERM. MODELS
ARE IN GOOD AGREEMENT AND WILL USE A CONSENSUS. WITH MOSTLY CLEAR TO
CLEAR SKIES THROUGHOUT THE SHORT TERM STUCK CLOSE TO COOLER GUIDANCE
NUMBERS AT NIGHT OF LOW TO MIDDLE 20S. FOR HIGHS TUESDAY AGAIN THOUGHT
GUIDANCE WAS BIASED A BIT WARM FROM CLIMATOLOGY SO STUCK WITH A RAW
MODEL CONSENSUS IN THE LOW TO MID 40S...BUT BY WEDNESDAY THE AIR
MASS SHOULD BE REBOUNDING UNDER WARM ADVECTION AND A COMPLETE
CONSENSUS LOOKED GOOD IN THE UPPER 40S TO LOW 50S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 324 AM EDT MON APR 1 2013
A LARGE AREA OF HIGH PRESSURE WILL BE MOVING AWAY TO THE EAST ON
THURSDAY WITH A SPLIT FLOW PATTERN ALOFT AS A WEAK FRONT
APPROACHES FROM THE NORTHWEST AND AN UPPER LOW TRACKS ACROSS THE
SOUTHERN PLAINS. MODEL CONSENSUS HAS BEEN TRACKING THE UPPER WAVE
FURTHER NORTH OVER THE LAST COUPLE DAYS AND BRINGS THE NORTHERN
FRINGES OF THE RAINFALL ASSOCIATED WITH THE UPPER LOW INTO THE
OHIO RIVER VALLEY THURSDAY NIGHT. CONSIDERING THE NORTHERLY LOW
LEVEL FLOW...PRESENCE OF DRIER AIR OVER THE REGION AND THE BULK OF
THE DEEPER FORCING REMAINING TO THE SOUTH OF THE FORECAST
AREA...WILL CONTINUE TO KEEP A DRY FORECAST GOING THURSDAY NIGHT.
DO ANTICIPATE AN INCREASE IN CLOUDS OVER THE SOUTHERN COUNTIES
THURSDAY NIGHT AND EARLY FRIDAY AS THE UPPER WAVE PASSES TO THE
SOUTH. THE AFOREMENTIONED WEAK FRONT APPROACHING FROM THE
NORTHWEST SET TO WASH OUT ACROSS THE LOWER GREAT LAKES THURSDAY
NIGHT.
AS THE UPPER WAVE WEAKENS AND SHIFTS INTO THE SOUTHEAST STATES BY
FRIDAY AFTERNOON...HIGH PRESSURE WILL REESTABLISH ACROSS THE OHIO
VALLEY WITH AN EXPANSION OF RIDGING ALOFT BRINGING WARMER AIR INTO
THE REGION. LOW LEVEL THERMALS SUPPORT HIGH TEMPS RISING INTO THE 60S
BY SATURDAY. FORECAST MORE MUDDLED FOR THE SECOND HALF OF THE
WEEKEND AS A DEVELOPING WARM FRONT SETS UP OVER THE LOWER GREAT
LAKES AND A SURFACE WAVE TRACKS ALONG THE BOUNDARY ON SUNDAY. WILL
CARRY LOW CHANCE POPS SATURDAY NIGHT INTO SUNDAY AS THE SURFACE
WAVE PASSES THROUGH THE AREA. APPEARS THE BOUNDARY MAY SETTLE
FURTHER SOUTH NEAR THE OHIO RIVER BY LATE SUNDAY WITH THE PASSAGE
OF THE LOW...BEFORE THE BOUNDARY RETURNS BACK NORTH EARLY NEXT
WEEK. LOW LEVEL THERMALS STILL SUGGESTIVE OF HIGHS IN THE 60S FOR
SUNDAY EVEN AS THE BOUNDARY SHIFTS SOUTH...WITH POSSIBILITY FOR
WARMER DAYTIME HIGHS EARLY NEXT WEEK ONCE THE FRONT LIFTS BACK
NORTH.
&&
.AVIATION /DISCUSSION FOR THE 01/06Z TAFS/...
ISSUED AT 104 AM EDT MON APR 1 2013
VFR THROUGH THE PERIOD.
SCT TO BKN MID CLOUD LIKELY THE ONLY SKY COVER THROUGH THE NIGHT.
WINDS WILL ONCE AGAIN GUST TOMORROW TO NEAR 20KT...AND DIURNAL
CUMULUS WILL FORM AROUND 5KFT.
NO VISIBILITY ISSUES ANTICIPATED THROUGH THE PERIOD.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....RYAN
AVIATION...NIELD
AREA FORECAST DISCUSSION
NWS WICHITA KS
1230 PM CDT MON APR 1 2013
.UPDATE...
ISSUED AT 1229 PM CDT MON APR 1 2013
PUT OUT ANOTHER UPDATE TO ADD LIGHT SNOW AS A PRECIP TYPE BASED ON
LATEST REPORTS. HOWEVER THE BIGGER REASON FOR THE UPDATE WAS TO DROP
HIGHS TODAY SEVERAL DEGREES.
ISENTROPIC LIFT NORTH OF THE SURFACE COLD FRONT HAS RESULTED IN
NUMEROUS RAIN/SNOW SHOWERS ACROSS MOST OF SOUTH CENTRAL KS. THIS
ACTIVITY SHOULD CONTINUE TRACKING OFF TO THE EAST-SOUTHEAST THIS
AFTERNOON. WITH WARM GROUND TEMPS...NO ACCUMULATION IS EXPECTED.
THE INCREASED CLOUD COVER WILL COMBINE WITH TEMPS WET-BULBING DOWN
TO KEEP TEMPS FROM CLIMBING MUCH THIS AFTERNOON. SO WENT AHEAD AND
DROPPED HIGHS SEVERAL DEGREES.
UPDATE ISSUED AT 1013 AM CDT MON APR 1 2013
SENT OUT A QUICK UPDATE TO KEEP UP WITH CURRENT PRECIP TRENDS.
ISENTROPIC LIFT ALONG THE 305K SURFACE HAS RESULTED IN PRECIP
EXPANDING OVER SW PORTIONS OF THE FORECAST AREA. THIS ACTIVITY
SHOULD CONTINUE TO PUSH EAST LATE THIS MORNING INTO THE EARLY
AFTERNOON HOURS. A COUPLE RUMBLES OF THUNDER MAY MIX WITH THE
SHOWERS.
LAWSON
&&
.SYNOPSIS...
ISSUED AT 332 AM CDT MON APR 1 2013
A POTENT DISTURBANCE IS PLUNGING SOUTHWARD INTO THE GREAT LAKES
REGION...CAUSING A COLD FRONT TO DIVE SOUTHWARD ACROSS THE CENTRAL
PLAINS. THE COLD FRONT HAS MADE IT HALF WAY THROUGH KANSAS AS OF
THIS ISSUANCE AND WILL CONTINUE TO MOVE SOUTHWARD THROUGH OKLAHOMA
DURING THE DAY. WINDS ARE GUSTY BEHIND THE FRONT WITH LOW TO MID
LEVEL CLOUDS. LOOKING WEST...ANOTHER DISTURBANCE IS LOCATED OVER
MID-CALIFORNIA/NEVADA/UTAH. THIS WILL BE THE WEATHER MAKER FOR THE
FIRST PART OF THE WEEK.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 332 AM CDT MON APR 1 2013
THIS PERIOD WILL BE RAINY OFF AND ON AND COOLER FOR MUCH OF SOUTHERN
KANSAS. THE LATEST GUIDANCE...NAM/GFS/ECMWF AND HRRR INDICATE
PRECIPITATION DEVELOPING ACROSS SOUTH CENTRAL KANSAS AROUND MID
AFTERNOON TODAY BEFORE SPREADING EAST ACROSS SOUTHERN KANSAS THROUGH
THE DAY AND OVERNIGHT. PRECIPITATION WILL DEVELOP NEAR THE 850MB
FRONT. THE UPPER LEVEL WAVE OVER THE WEST WILL CONTINUE TO MOVE
TOWARDS THE AREA...ENHANCING UPPER LEVEL SUPPORT. THE 850MB FRONT
WILL REMAIN STATIONARY...KEEPING THE PRECIPITATION CHANCES THROUGH
WEDNESDAY. NOT EXPECTING THUNDER WITH THIS EVENT WITH VERY LOW
MUCAPE VALUES...BUT CANNOT RULE OUT AN ISOLATED LIGHTNING STRIKE.
THIS PERIOD WILL REMAIN COOLER...AS THE COLD FRONT USHERED IN
UNSEASONABLY COOL AIR. WITH COLD AIR ADVECTION...CLOUDY SKIES AND
RAIN...TEMPERATURES WILL BE 10 TO 20 DEGREES BELOW NORMAL. TUESDAY
LOOKS TO BE THE COOLEST DAY WITH CLOUD COVER AND RAIN.
BILLINGS
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 332 AM CDT MON APR 1 2013
BY THURSDAY THE UPPER LEVEL DISTURBANCE THAT WILL IMPACT THE AREA
FOR THE FIRST HALF OF THE FORECAST WILL FINALLY BE ON ITS WAY EAST.
SURFACE HIGH PRESSURE WILL MOVE OVERHEAD THURSDAY WITH CLEARING
SKIES IN THE SUBSIDENCE ZONE OF THE UPPER WAVE. THIS WILL ALLOW
TEMPERATURES TO WARM BACK INTO THE UPPER 50S AND LOW 60S.
TEMPERATURES WILL CONTINUE TO INCREASE FOR FRIDAY AND SATURDAY AHEAD
OF THE NEXT SYSTEM. LEE CYCLOGENESIS WILL DEEPEN AHEAD OF THE NEXT
WAVE...WITH STRONG WARM AIR ADVECTION AND MIXING...TEMPS WILL REACH
BACK INTO THE 60S AND 70S. THE NEXT DISTURBANCE WILL MOVE ACROSS
THE NORTHERN PLAINS...DRAGGING A COLD FRONT ACROSS THE REGION. THE
MAIN LIFT ASSOCIATED WITH THIS FRONT WILL BE ACROSS THE NORTHERN
PLAINS...SO NOT EXPECTING MUCH IN THE WAY OF PRECIPITATION ALONG THE
FRONTAL BOUNDARY AND HAVE LEFT THE FORECAST DRY FOR SATURDAY AND
SUNDAY. TEMPERATURES BEHIND THE FRONT WILL ONLY DECREASE SLIGHTLY.
ANOTHER WAVE WILL APPROACH FOR THE VERY END OF THE FORECAST AND
PRECIPITATION MAY RETURN FOR SUNDAY AND INTO THE EARLY PART OF NEXT
WEEK. WILL CONTINUE TO WATCH THIS PERIOD AS THE FORECAST EVOLVES AS
THE TIME PERIOD NEARS.
BILLINGS
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1229 PM CDT MON APR 1 2013
MAIN AVIATION FORECAST CONCERNS WILL PRECIP THIS AFTERNOON ALONG
WITH LOWERING CIGS TONIGHT.
THE PRECIP AFFECTING SOUTH CENTRAL KS WILL CONTINUE SLOWLY TRACKING
OFF TO THE SOUTHEAST THIS AFTERNOON WITH MAINLY KICT BEING AFFECTED.
A RAIN-SNOW MIX WILL BE THE MAIN PRECIP TYPE. THERE SHOULD BE A
BREAK IN THE PRECIP LATE THIS AFTERNOON/EARLY THIS EVENING BEFORE
ISENTROPIC LIFT GETS CRANKED UP AGAIN AFTER DARK. HOWEVER FOR THIS
EVENING FEEL THAT THE BULK OF THE PRECIP WILL BE SOUTH OF THE KS-OK
BORDER WITH KICT BEING ON THE NORTHERN FRINGES OF THE PRECIP. IN
ADDITION...CIGS WILL START TO LOWER TOWARD SUNRISE ACROSS SOUTH
CENTRAL KS WITH KICT POSSIBLY GETTING INTO SOME MVFR CONDITIONS BY
12Z.
LAWSON
&&
.FIRE WEATHER...
ISSUED AT 332 AM CDT MON APR 1 2013
VERY LITTLE IN THE WAY OF FIRE CONCERN FOR MUCH OF THE FORECAST.
LIGHT WINDS AND PRECIPITATION WILL KEEP GRASSLAND FIRE DANGER LOW.
WITH STRONGER WINDS AND WARMER TEMPERATURES ON FRIDAY...GRASSLAND
FIRE DANGER WILL BE VERY HIGH.
BILLINGS
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 45 35 43 35 / 80 60 50 30
HUTCHINSON 42 33 45 32 / 50 40 40 20
NEWTON 43 32 43 31 / 50 30 30 20
ELDORADO 45 33 44 33 / 80 40 40 20
WINFIELD-KWLD 49 36 42 36 / 90 70 70 40
RUSSELL 43 30 48 30 / 10 30 20 10
GREAT BEND 42 31 46 31 / 20 30 30 20
SALINA 43 31 50 33 / 10 20 10 10
MCPHERSON 42 32 46 32 / 20 30 20 10
COFFEYVILLE 52 37 44 36 / 70 60 70 40
CHANUTE 48 34 44 34 / 40 30 30 10
IOLA 47 33 45 33 / 20 20 20 10
PARSONS-KPPF 50 35 44 35 / 60 50 50 30
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1013 AM CDT MON APR 1 2013
.UPDATE...
ISSUED AT 1013 AM CDT MON APR 1 2013
SENT OUT A QUICK UPDATE TO KEEP UP WITH CURRENT PRECIP TRENDS.
ISENTROPIC LIFT ALONG THE 305K SURFACE HAS RESULTED IN PRECIP
EXPANDING OVER SW PORTIONS OF THE FORECAST AREA. THIS ACTIVITY
SHOULD CONTINUE TO PUSH EAST LATE THIS MORNING INTO THE EARLY
AFTERNOON HOURS. A COUPLE RUMBLES OF THUNDER MAY MIX WITH THE
SHOWERS.
LAWSON
&&
.SYNOPSIS...
ISSUED AT 332 AM CDT MON APR 1 2013
A POTENT DISTURBANCE IS PLUNGING SOUTHWARD INTO THE GREAT LAKES
REGION...CAUSING A COLD FRONT TO DIVE SOUTHWARD ACROSS THE CENTRAL
PLAINS. THE COLD FRONT HAS MADE IT HALF WAY THROUGH KANSAS AS OF
THIS ISSUANCE AND WILL CONTINUE TO MOVE SOUTHWARD THROUGH OKLAHOMA
DURING THE DAY. WINDS ARE GUSTY BEHIND THE FRONT WITH LOW TO MID
LEVEL CLOUDS. LOOKING WEST...ANOTHER DISTURBANCE IS LOCATED OVER
MID-CALIFORNIA/NEVADA/UTAH. THIS WILL BE THE WEATHER MAKER FOR THE
FIRST PART OF THE WEEK.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 332 AM CDT MON APR 1 2013
THIS PERIOD WILL BE RAINY OFF AND ON AND COOLER FOR MUCH OF SOUTHERN
KANSAS. THE LATEST GUIDANCE...NAM/GFS/ECMWF AND HRRR INDICATE
PRECIPITATION DEVELOPING ACROSS SOUTH CENTRAL KANSAS AROUND MID
AFTERNOON TODAY BEFORE SPREADING EAST ACROSS SOUTHERN KANSAS THROUGH
THE DAY AND OVERNIGHT. PRECIPITATION WILL DEVELOP NEAR THE 850MB
FRONT. THE UPPER LEVEL WAVE OVER THE WEST WILL CONTINUE TO MOVE
TOWARDS THE AREA...ENHANCING UPPER LEVEL SUPPORT. THE 850MB FRONT
WILL REMAIN STATIONARY...KEEPING THE PRECIPITATION CHANCES THROUGH
WEDNESDAY. NOT EXPECTING THUNDER WITH THIS EVENT WITH VERY LOW
MUCAPE VALUES...BUT CANNOT RULE OUT AN ISOLATED LIGHTNING STRIKE.
THIS PERIOD WILL REMAIN COOLER...AS THE COLD FRONT USHERED IN
UNSEASONABLY COOL AIR. WITH COLD AIR ADVECTION...CLOUDY SKIES AND
RAIN...TEMPERATURES WILL BE 10 TO 20 DEGREES BELOW NORMAL. TUESDAY
LOOKS TO BE THE COOLEST DAY WITH CLOUD COVER AND RAIN.
BILLINGS
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 332 AM CDT MON APR 1 2013
BY THURSDAY THE UPPER LEVEL DISTURBANCE THAT WILL IMPACT THE AREA
FOR THE FIRST HALF OF THE FORECAST WILL FINALLY BE ON ITS WAY EAST.
SURFACE HIGH PRESSURE WILL MOVE OVERHEAD THURSDAY WITH CLEARING
SKIES IN THE SUBSIDENCE ZONE OF THE UPPER WAVE. THIS WILL ALLOW
TEMPERATURES TO WARM BACK INTO THE UPPER 50S AND LOW 60S.
TEMPERATURES WILL CONTINUE TO INCREASE FOR FRIDAY AND SATURDAY AHEAD
OF THE NEXT SYSTEM. LEE CYCLOGENESIS WILL DEEPEN AHEAD OF THE NEXT
WAVE...WITH STRONG WARM AIR ADVECTION AND MIXING...TEMPS WILL REACH
BACK INTO THE 60S AND 70S. THE NEXT DISTURBANCE WILL MOVE ACROSS
THE NORTHERN PLAINS...DRAGGING A COLD FRONT ACROSS THE REGION. THE
MAIN LIFT ASSOCIATED WITH THIS FRONT WILL BE ACROSS THE NORTHERN
PLAINS...SO NOT EXPECTING MUCH IN THE WAY OF PRECIPITATION ALONG THE
FRONTAL BOUNDARY AND HAVE LEFT THE FORECAST DRY FOR SATURDAY AND
SUNDAY. TEMPERATURES BEHIND THE FRONT WILL ONLY DECREASE SLIGHTLY.
ANOTHER WAVE WILL APPROACH FOR THE VERY END OF THE FORECAST AND
PRECIPITATION MAY RETURN FOR SUNDAY AND INTO THE EARLY PART OF NEXT
WEEK. WILL CONTINUE TO WATCH THIS PERIOD AS THE FORECAST EVOLVES AS
THE TIME PERIOD NEARS.
BILLINGS
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 648 AM CDT MON APR 1 2013
A SHARP COLD FRONT HAS ALREADY MOVED ACROSS MOST LOCATIONS THIS
MORNING EXPECT SOME GUSTY WINDS TO 25 KTS FOR A FEW HOURS AFTER THE
FRONT MOVES THROUGH. WILL ALSO SEE SOME POST FRONTAL MVFR CEILINGS
ALSO DROP SOUTH ACROSS THE REGION FOR A FEW HOURS AFTER THE FRONT
PASSES...WITH CEILINGS OF 1500 FT AGL. EXPECT THIS MVFR CLOUD DECK
TO BE SHORT LIVED....WITH LOWER CLOUDS STAYING AROUND FOR ONLY 4 OR
5 HOURS. LIFT OVER THE TOP OF THE SHALLOW COLD AIR ACROSS SRN
KS...WILL LEAD TO A CHANCE OF SOME LIGHT RAIN SHOWERS FOR MAINLY SRN
KS. SO WILL INCLUDE A VCSH FOR THE KICT/KHUT AND KCNU TAF SITES
AFTER 22Z/MON. WILL SEE MORE OF WIDESPREAD LIGHT RAIN CHANCE DEVELOP
LATE TNGT INTO TUE AM...AFTER 12Z TUE. COULD ALSO SEE CEILINGS DROP
TO LOW MVFR OR POSSIBLY IFR ACROSS SRN KS ON TUE....BUT THIS IS
BEYOND THIS TAF TIME FRAME.
KETCHAM
&&
.FIRE WEATHER...
ISSUED AT 332 AM CDT MON APR 1 2013
VERY LITTLE IN THE WAY OF FIRE CONCERN FOR MUCH OF THE FORECAST.
LIGHT WINDS AND PRECIPITATION WILL KEEP GRASSLAND FIRE DANGER LOW.
WITH STRONGER WINDS AND WARMER TEMPERATURES ON FRIDAY...GRASSLAND
FIRE DANGER WILL BE VERY HIGH.
BILLINGS
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 51 35 43 35 / 40 60 50 30
HUTCHINSON 50 33 45 32 / 30 40 40 20
NEWTON 51 32 43 31 / 20 30 30 20
ELDORADO 51 33 44 33 / 30 40 40 20
WINFIELD-KWLD 53 36 42 36 / 40 70 70 40
RUSSELL 51 30 48 30 / 10 30 20 10
GREAT BEND 50 31 46 31 / 20 30 30 20
SALINA 52 31 50 33 / 10 20 10 10
MCPHERSON 51 32 46 32 / 20 30 20 10
COFFEYVILLE 55 37 44 36 / 30 60 70 40
CHANUTE 53 34 44 34 / 20 30 30 10
IOLA 52 33 45 33 / 20 20 20 10
PARSONS-KPPF 53 35 44 35 / 30 50 50 30
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
651 AM CDT MON APR 1 2013
.SYNOPSIS...
ISSUED AT 332 AM CDT MON APR 1 2013
A POTENT DISTURBANCE IS PLUNGING SOUTHWARD INTO THE GREAT LAKES
REGION...CAUSING A COLD FRONT TO DIVE SOUTHWARD ACROSS THE CENTRAL
PLAINS. THE COLD FRONT HAS MADE IT HALF WAY THROUGH KANSAS AS OF
THIS ISSUANCE AND WILL CONTINUE TO MOVE SOUTHWARD THROUGH OKLAHOMA
DURING THE DAY. WINDS ARE GUSTY BEHIND THE FRONT WITH LOW TO MID
LEVEL CLOUDS. LOOKING WEST...ANOTHER DISTURBANCE IS LOCATED OVER
MID-CALIFORNIA/NEVADA/UTAH. THIS WILL BE THE WEATHER MAKER FOR THE
FIRST PART OF THE WEEK.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 332 AM CDT MON APR 1 2013
THIS PERIOD WILL BE RAINY OFF AND ON AND COOLER FOR MUCH OF SOUTHERN
KANSAS. THE LATEST GUIDANCE...NAM/GFS/ECMWF AND HRRR INDICATE
PRECIPITATION DEVELOPING ACROSS SOUTH CENTRAL KANSAS AROUND MID
AFTERNOON TODAY BEFORE SPREADING EAST ACROSS SOUTHERN KANSAS THROUGH
THE DAY AND OVERNIGHT. PRECIPITATION WILL DEVELOP NEAR THE 850MB
FRONT. THE UPPER LEVEL WAVE OVER THE WEST WILL CONTINUE TO MOVE
TOWARDS THE AREA...ENHANCING UPPER LEVEL SUPPORT. THE 850MB FRONT
WILL REMAIN STATIONARY...KEEPING THE PRECIPITATION CHANCES THROUGH
WEDNESDAY. NOT EXPECTING THUNDER WITH THIS EVENT WITH VERY LOW
MUCAPE VALUES...BUT CANNOT RULE OUT AN ISOLATED LIGHTNING STRIKE.
THIS PERIOD WILL REMAIN COOLER...AS THE COLD FRONT USHERED IN
UNSEASONABLY COOL AIR. WITH COLD AIR ADVECTION...CLOUDY SKIES AND
RAIN...TEMPERATURES WILL BE 10 TO 20 DEGREES BELOW NORMAL. TUESDAY
LOOKS TO BE THE COOLEST DAY WITH CLOUD COVER AND RAIN.
BILLINGS
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 332 AM CDT MON APR 1 2013
BY THURSDAY THE UPPER LEVEL DISTURBANCE THAT WILL IMPACT THE AREA
FOR THE FIRST HALF OF THE FORECAST WILL FINALLY BE ON ITS WAY EAST.
SURFACE HIGH PRESSURE WILL MOVE OVERHEAD THURSDAY WITH CLEARING
SKIES IN THE SUBSIDENCE ZONE OF THE UPPER WAVE. THIS WILL ALLOW
TEMPERATURES TO WARM BACK INTO THE UPPER 50S AND LOW 60S.
TEMPERATURES WILL CONTINUE TO INCREASE FOR FRIDAY AND SATURDAY AHEAD
OF THE NEXT SYSTEM. LEE CYCLOGENESIS WILL DEEPEN AHEAD OF THE NEXT
WAVE...WITH STRONG WARM AIR ADVECTION AND MIXING...TEMPS WILL REACH
BACK INTO THE 60S AND 70S. THE NEXT DISTURBANCE WILL MOVE ACROSS
THE NORTHERN PLAINS...DRAGGING A COLD FRONT ACROSS THE REGION. THE
MAIN LIFT ASSOCIATED WITH THIS FRONT WILL BE ACROSS THE NORTHERN
PLAINS...SO NOT EXPECTING MUCH IN THE WAY OF PRECIPITATION ALONG THE
FRONTAL BOUNDARY AND HAVE LEFT THE FORECAST DRY FOR SATURDAY AND
SUNDAY. TEMPERATURES BEHIND THE FRONT WILL ONLY DECREASE SLIGHTLY.
ANOTHER WAVE WILL APPROACH FOR THE VERY END OF THE FORECAST AND
PRECIPITATION MAY RETURN FOR SUNDAY AND INTO THE EARLY PART OF NEXT
WEEK. WILL CONTINUE TO WATCH THIS PERIOD AS THE FORECAST EVOLVES AS
THE TIME PERIOD NEARS.
BILLINGS
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 648 AM CDT MON APR 1 2013
A SHARP COLD FRONT HAS ALREADY MOVED ACROSS MOST LOCATIONS THIS
MORNING EXPECT SOME GUSTY WINDS TO 25 KTS FOR A FEW HOURS AFTER THE
FRONT MOVES THROUGH. WILL ALSO SEE SOME POST FRONTAL MVFR CEILINGS
ALSO DROP SOUTH ACROSS THE REGION FOR A FEW HOURS AFTER THE FRONT
PASSES...WITH CEILINGS OF 1500 FT AGL. EXPECT THIS MVFR CLOUD DECK
TO BE SHORT LIVED....WITH LOWER CLOUDS STAYING AROUND FOR ONLY 4 OR
5 HOURS. LIFT OVER THE TOP OF THE SHALLOW COLD AIR ACROSS SRN
KS...WILL LEAD TO A CHANCE OF SOME LIGHT RAIN SHOWERS FOR MAINLY SRN
KS. SO WILL INCLUDE A VCSH FOR THE KICT/KHUT AND KCNU TAF SITES
AFTER 22Z/MON. WILL SEE MORE OF WIDESPREAD LIGHT RAIN CHANCE DEVELOP
LATE TNGT INTO TUE AM...AFTER 12Z TUE. COULD ALSO SEE CEILINGS DROP
TO LOW MVFR OR POSSIBLY IFR ACROSS SRN KS ON TUE....BUT THIS IS
BEYOND THIS TAF TIME FRAME.
KETCHAM
&&
.FIRE WEATHER...
ISSUED AT 332 AM CDT MON APR 1 2013
VERY LITTLE IN THE WAY OF FIRE CONCERN FOR MUCH OF THE FORECAST.
LIGHT WINDS AND PRECIPITATION WILL KEEP GRASSLAND FIRE DANGER LOW.
WITH STRONGER WINDS AND WARMER TEMPERATURES ON FRIDAY...GRASSLAND
FIRE DANGER WILL BE VERY HIGH.
BILLINGS
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 51 35 43 35 / 40 60 50 30
HUTCHINSON 50 33 45 32 / 30 40 40 20
NEWTON 51 32 43 31 / 30 30 30 20
ELDORADO 51 33 44 33 / 30 40 40 20
WINFIELD-KWLD 53 36 42 36 / 40 70 70 40
RUSSELL 51 30 48 30 / 20 30 20 10
GREAT BEND 50 31 46 31 / 20 30 30 20
SALINA 52 31 50 33 / 20 20 10 10
MCPHERSON 51 32 46 32 / 30 30 20 10
COFFEYVILLE 55 37 44 36 / 40 60 70 40
CHANUTE 53 34 44 34 / 30 30 30 10
IOLA 52 33 45 33 / 30 20 20 10
PARSONS-KPPF 53 35 44 35 / 30 50 50 30
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
335 AM CDT MON APR 1 2013
.SYNOPSIS...
ISSUED AT 332 AM CDT MON APR 1 2013
A POTENT DISTURBANCE IS PLUNGING SOUTHWARD INTO THE GREAT LAKES
REGION...CAUSING A COLD FRONT TO DIVE SOUTHWARD ACROSS THE CENTRAL
PLAINS. THE COLD FRONT HAS MADE IT HALF WAY THROUGH KANSAS AS OF
THIS ISSUANCE AND WILL CONTINUE TO MOVE SOUTHWARD THROUGH OKLAHOMA
DURING THE DAY. WINDS ARE GUSTY BEHIND THE FRONT WITH LOW TO MID
LEVEL CLOUDS. LOOKING WEST...ANOTHER DISTURBANCE IS LOCATED OVER
MID-CALIFORNIA/NEVADA/UTAH. THIS WILL BE THE WEATHER MAKER FOR THE
FIRST PART OF THE WEEK.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 332 AM CDT MON APR 1 2013
THIS PERIOD WILL BE RAINY OFF AND ON AND COOLER FOR MUCH OF SOUTHERN
KANSAS. THE LATEST GUIDANCE...NAM/GFS/ECMWF AND HRRR INDICATE
PRECIPITATION DEVELOPING ACROSS SOUTH CENTRAL KANSAS AROUND MID
AFTERNOON TODAY BEFORE SPREADING EAST ACROSS SOUTHERN KANSAS THROUGH
THE DAY AND OVERNIGHT. PRECIPITATION WILL DEVELOP NEAR THE 850MB
FRONT. THE UPPER LEVEL WAVE OVER THE WEST WILL CONTINUE TO MOVE
TOWARDS THE AREA...ENHANCING UPPER LEVEL SUPPORT. THE 850MB FRONT
WILL REMAIN STATIONARY...KEEPING THE PRECIPITATION CHANCES THROUGH
WEDNESDAY. NOT EXPECTING THUNDER WITH THIS EVENT WITH VERY LOW
MUCAPE VALUES...BUT CANNOT RULE OUT AN ISOLATED LIGHTNING STRIKE.
THIS PERIOD WILL REMAIN COOLER...AS THE COLD FRONT USHERED IN
UNSEASONABLY COOL AIR. WITH COLD AIR ADVECTION...CLOUDY SKIES AND
RAIN...TEMPERATURES WILL BE 10 TO 20 DEGREES BELOW NORMAL. TUESDAY
LOOKS TO BE THE COOLEST DAY WITH CLOUD COVER AND RAIN.
BILLINGS
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 332 AM CDT MON APR 1 2013
BY THURSDAY THE UPPER LEVEL DISTURBANCE THAT WILL IMPACT THE AREA
FOR THE FIRST HALF OF THE FORECAST WILL FINALLY BE ON ITS WAY EAST.
SURFACE HIGH PRESSURE WILL MOVE OVERHEAD THURSDAY WITH CLEARING
SKIES IN THE SUBSIDENCE ZONE OF THE UPPER WAVE. THIS WILL ALLOW
TEMPERATURES TO WARM BACK INTO THE UPPER 50S AND LOW 60S.
TEMPERATURES WILL CONTINUE TO INCREASE FOR FRIDAY AND SATURDAY AHEAD
OF THE NEXT SYSTEM. LEE CYCLOGENESIS WILL DEEPEN AHEAD OF THE NEXT
WAVE...WITH STRONG WARM AIR ADVECTION AND MIXING...TEMPS WILL REACH
BACK INTO THE 60S AND 70S. THE NEXT DISTURBANCE WILL MOVE ACROSS
THE NORTHERN PLAINS...DRAGGING A COLD FRONT ACROSS THE REGION. THE
MAIN LIFT ASSOCIATED WITH THIS FRONT WILL BE ACROSS THE NORTHERN
PLAINS...SO NOT EXPECTING MUCH IN THE WAY OF PRECIPITATION ALONG THE
FRONTAL BOUNDARY AND HAVE LEFT THE FORECAST DRY FOR SATURDAY AND
SUNDAY. TEMPERATURES BEHIND THE FRONT WILL ONLY DECREASE SLIGHTLY.
ANOTHER WAVE WILL APPROACH FOR THE VERY END OF THE FORECAST AND
PRECIPITATION MAY RETURN FOR SUNDAY AND INTO THE EARLY PART OF NEXT
WEEK. WILL CONTINUE TO WATCH THIS PERIOD AS THE FORECAST EVOLVES AS
THE TIME PERIOD NEARS.
BILLINGS
&&
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
ISSUED AT 1208 AM CDT MON APR 1 2013
AT 05Z A STRONG ALMOST E-W ORIENTED COLD FRONT THAT HAS BEEN MOVING S
THIS EVENING ENTERED NRN KS ~03Z & SHOULD STILL ARRIVE KRSL & KSLN 08Z.
THE COLD FRONT SHOULD REACH SC & SE KS ~10Z. DURING FRONTAL PASSAGE
WINDS THAT ARE VARIABLE <7KTS WILL QUICKLY & ABRUPTLY SHIFT TOWARD THE
NE & INCREASE TO A SUSTAINED ~17KTS/20MPH WITH GUSTS ~25KTS. POST-COLD
FRONTAL ~1,500FT STRATOCU WILL SPREAD OVER PRIMARILY KSLN ~11Z BUT ONLY
LAST TIL ~15Z. NE WINDS WILL GRADUALLY DIMINISH IN A N-S MANNER AS HIGH
PRESSURE SPREADS S/SE FROM THE DAKOTAS TO NEBRASKA.
ES
&&
.FIRE WEATHER...
ISSUED AT 332 AM CDT MON APR 1 2013
VERY LITTLE IN THE WAY OF FIRE CONCERN FOR MUCH OF THE FORECAST.
LIGHT WINDS AND PRECIPITATION WILL KEEP GRASSLAND FIRE DANGER LOW.
WITH STRONGER WINDS AND WARMER TEMPERATURES ON FRIDAY...GRASSLAND
FIRE DANGER WILL BE VERY HIGH.
BILLINGS
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 51 35 43 35 / 40 60 50 30
HUTCHINSON 50 33 45 32 / 30 40 40 20
NEWTON 51 32 43 31 / 30 30 30 20
ELDORADO 51 33 44 33 / 30 40 40 20
WINFIELD-KWLD 53 36 42 36 / 40 70 70 40
RUSSELL 51 30 48 30 / 20 30 20 10
GREAT BEND 50 31 46 31 / 20 30 30 20
SALINA 52 31 50 33 / 20 20 10 10
MCPHERSON 51 32 46 32 / 30 30 20 10
COFFEYVILLE 55 37 44 36 / 40 60 70 40
CHANUTE 53 34 44 34 / 30 30 30 10
IOLA 52 33 45 33 / 30 20 20 10
PARSONS-KPPF 53 35 44 35 / 30 50 50 30
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
927 AM EDT MON APR 1 2013
.SYNOPSIS...
NORTHWEST WINDS WILL PROVIDE BELOW NORMAL TEMPERATURES THROUGH
MIDWEEK. AN UPPER LEVEL SYSTEM WILL BRING THE RISK FOR RAIN OR
SNOW SHOWERS TODAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A MIX OF RAIN AND SNOW SHOWERS CONTINUE TO CROSS THE REGION ALONG
AND BEHIND THE COLD FRONT THIS MORNING. HAVE BUMPED UP THE POPS
ACCORDINGLY USING RUC DATA THAT SEEMS TO BE HANDLING THE TIMING
AND SCATTERED NATURE OF THE SHOWERS QUITE WELL. TEMPERATURES AHEAD
OF THIS BOUNDARY HAVE WARMED UP SLIGHTLY BUT THIS WILL BE BRIEF AS
COLD ADVECTION SHOULD GENERALLY KEEP A DOWNWARD TREND IN TEMPS
DURING THE DAY.
LATEST MODEL SOUNDINGS ARE SHOWING A DRY AIR MASS SETTLING IN THE
LOWER LEVELS THIS AFTERNOON. THIS WILL LIMIT LAKE EFFECT /UP-SLOPE
SNOW SHOWER DEVELOPMENT. THE HIGHEST RIDGES WILL HAVE THE BEST
CHANCE TO SEE MORE NUMEROUS SNOW SHOWERS AS ELEVATION WILL KEEP
THEM IN A THE SATURATED LAYER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
OUR BRIEF ACQUAINTANCE WITH SPRING WILL SADLY DEPART AS WE ONCE
AGAIN RETURN TO A PATTERN MORE REMINISCENT OF WINTER WITH THE
EASTERN HALF OF THE CONUS UNDER THE INFLUENCE OF A LARGE UPPER
LEVEL TROUGH THROUGH MUCH OF THE PERIOD. WHILE THE UPPER LEVEL
FLOW MAY KEEP A SLIGHTLY MORE WESTERLY THAN NORTHWESTERLY
COMPONENT...SHORTWAVES DIVING THROUGH THE COLD UPPER LEVEL FLOW
SHOULD PROVIDE AT LEAST CLOUD COVER THROUGH LATE TUESDAY AND SOME
LAKE ENHANCED SNOW SHOWERS POSSIBLE IMMEDIATELY DOWNWIND OF LAKE
ERIE...THOUGH IT IS QUESTIONABLE TO WHETHER IT WILL REALLY IMPACT
OUR NORTHERN ZONES VERY MUCH.
BY WEDNESDAY...MODELS SHOW A FEW INCONSISTENCIES IN THE PLACEMENT
AND STRENGTH OF A SHORTWAVE DIVING THROUGH THE TROUGH AND ITS
IMPACT TO THE REGION. AS SUCH...OPTED TO REMAIN CLOSER TO THE
ENSEMBLE MEANS WHICH KEEP THE REGION DRY. EVEN FOR THE START OF
APRIL....COLD ADVECTION AND CLOUD COVER SHOULD KEEP TEMPERATURES
BELOW SEASONAL AVERAGES THROUGH THE PERIOD.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
MODEL AND ENSEMBLE SOLUTIONS ALL FAVOR A DRY EXTENDED FORECAST WITH
LOW PRES SUPPRESSED TO OUR SOUTH IN THE SPLIT FLOW PATTERN LATE IN
THE WEEK. HOWEVER...AS THE PRECIP SHIELD OF THAT SYSTEM MAY CLIP
THE SOUTHEASTERN PORTIONS OF THE FORECAST AREA...HAVE INCLUDED SLGT
TO CHC POPS FOR FRIDAY INTO FRIDAY NIGHT. HIGH PRESSURE IS
CURRENTLY TIMED TO BRING DRY WEATHER FOR SATURDAY....BUT ANOTHER
FRONT MAY BRING A CHANCE OF SHOWERS FOR SUNDAY..
TEMPERATURES THROUGH THE EXTENDED MODERATE TOWARD AVERAGE. WITH A
SPLIT FLOW LIKELY TO BE IN PLACE...OUR AREA SHOULD REMAIN LARGELY
LOCKED BETWEEN THE NORTHERN AND SOUTHERN STREAM. AS A RESULT...NO
WILD SWINGS OF TEMPS ARE ANTICIPATED.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
A RELATIVELY DRY COLD FRONT WILL CROSS THE TERMINALS THIS
MORNING...BRINGING A WIND SHIFT FROM SOUTHWESTERLY TO
NORTHWESTERLY WITH ITS PASSAGE. THE FRONT WILL CROSS THE TERMINALS
BETWEEN 09Z AND 13Z. WINDS BEHIND THE FRONT WILL INCREASE TO
AROUND 15KTS WITH GUSTS UP TO 25KTS LATE THIS MORNING INTO THE
AFTERNOON.
WITH LITTLE PRECIPITATION EXPECTED OTHER THAN A STRAY SPRINKLE OR
FLURRY...VFR CONDITIONS ARE FORECAST ACROSS MOST OF THE
TERMINALS THROUGH THE TAF PERIOD. THE EXCEPTION IS AT
KFKL/KDUJ...WHERE TEMPO GROUPS ARE FORECAST FOR MVFR CEILINGS LATE
THIS MORNING.
.OUTLOOK.../TUESDAY THROUGH FRIDAY/...
A COLD NORTHWESTERLY FLOW WILL LEAD TO POSSIBLE RESTRICTIONS AT
KFKL/KDUJ ON TUESDAY AND TUESDAY NIGHT. OTHERWISE...GENERAL VFR
CONDITIONS CAN BE EXPECTED THROUGH THURSDAY NIGHT AS HIGH PRESSURE
BUILDS OVER THE REGION. A LOW PRESSURE SYSTEM PASSING SOUTH OF THE
AREA MAY BRING RAIN TO LOCATIONS SOUTH OF KPIT ON FRIDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GAYLORD MI
154 PM EDT MON APR 1 2013
.SYNOPSIS...
ISSUED AT 422 AM EDT MON APR 1 2013
A SYSTEM IN QUEBEC IS BRINGING COLD AIR AND NORTHWEST WINDS TO THE
STATE TODAY. THE COLDER AIR IS PRODUCING LAKE EFFECT SNOW SHOWERS
WHICH WILL PERSIST OVER NORTHERN MICHIGAN THROUGH TUESDAY. THE MOST
PERSISTENT SNOW SHOWERS WITH THE BEST CHANCE OF ACCUMULATION WILL BE
IN THE TYPICAL SNOW BELTS OF NORTHWEST LOWER AND EAST UPPER
MICHIGAN.
&&
.UPDATE...
ISSUED AT 153 PM EDT MON APR 1 2013
CURRENT FORECAST IS IN LINE. LAKE EFFECT SNOWS CONTINUE OVER NRN
MI...AS SFC-850MB WINDS LINGER FROM THE NW AND 850MB TEMPS REMAIN
ARND -16C.
UPDATE ISSUED AT 951 AM EDT MON APR 1 2013
THE STORM SYSTEM WHICH SWEPT ACROSS THE GREAT LAKES THIS WEEKEND...
HAS PUSHED EAST OF THE STATE AND WILL CONTINUE TO LIFT INTO QUEBEC
THROUGH TUESDAY. COLD 850MB TEMPS...NORTHWEST WINDS AND LAKE EFFECT
SNOWS HAD ALREADY BEGUN TO FILTER INTO NRN MI EARLIER THIS MORNING.
850MB TEMPS DROPPED FROM AROUND 0C SUNDAY AFTERNOON TO ARND -16C BY
12Z THIS MORNING.
AS FOR THE REST OF THE AFTN...THE PARAMETERS WHICH ARE CURRENTLY
GENERATING LAKE INDUCED SNOWS OVER THE WRN LAKES...ARE NOT EXPECTED
TO CHANGE MUCH THROUGH 21Z. 850MB TEMPS WILL LINGER AROUND -16C AS
THE AXIS OF THE SFC AND 500MB FEATURES PUSH FURTHER EAST OF THE REGION
THIS AFTERNOON. SFC-850MB WINDS WOBBLE DURING THE AFTN...THOUGH
REMAIN GENERALLY NW (300-320) WHILE INVERSION HEIGHTS LINGER AROUND
5K FT. OVERALL EXPECT WIDESPREAD LAKE SNOWS TO CONT OVER THE WRN
LAKES THROUGH THE AFTN...THOUGH WITH THE HIGH SUN ANGLE...EXPECT
DOMINATE SNOW BANDS TO BECOME A LEAST SLIGHTLY DISRUPTED THROUGH THE
REST OF THE MORNING. OVERALL WILL KEEP CONT TO MENTION LAKE SNOWS
THROUGH THE AFTN. WILL MENTION UP TO 2 INCHES OF SNOW POSSIBLE IN
FAVORED SNOW BELTS...AND WILL EXTEND HEADLINES THRU THE AFTN.
UPDATE ISSUED AT 708 AM EDT MON APR 1 2013
CHANGES THIS HOUR: ADDITIONAL /UPWARD/ ADJUSTMENTS TO SNOWFALL AS
A BAND OF NEARLY 5 INCHES HAS OCCURRED OVER EXTREME SW OTSEGO
COUNTY AND NW CRAWFORD COUNTY. BANDING IS MAKING ITS EXPECTED
SHIFT EAST...AND IS BEGINNING TO BECOME A LITTLE MORE DIFFUSE.
EXPECT WE/VE GOT 2-3 MORE HOURS OF DECENT ACCUMS BEFORE THINGS
WIND DOWN. ADVISORY CONTINUES TO LOOK GOOD AND WILL MAKE NO
CHANGES TO THIS.
UPDATE ISSUED AT 519 AM EDT MON APR 1 2013
CHANGES THIS HOUR: BAND HESITATED LONG ENOUGH FOR ME...AND HAVE
ISSUED A WINTER WEATHER ADVISORY FOR 4 OF THE BIG 5 /EXCLUDED
KALKASKA/ THROUGH NOON. RADAR ESTIMATES HAVE REACHED 2-3" IN
SPOTS...WITH BIG FLUFFY FLAKES FALLING HERE AT THE OFFICE
INDICATING 20:1 RATIOS LOOK GOOD. WINDS AMPLE TO BLOW THIS SNOW
AROUND AS WELL. EXPECT 2-4 OVER THE NEXT FEW HOURS AS BAND STARTS
TO EDGE EAST FROM ITS CURRENT LOCATION...BEFORE LIKELY BREAKING UP
BY LATE MORNING.
NO OTHER CHANGES ATTM.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 422 AM EDT MON APR 1 2013
HIGH IMPACT WEATHER POTENTIAL: GALE FORCE WIND GUSTS POSSIBLE ALL
MARINE WATERS THROUGH TODAY. SNOW/BLOWING SNOW WILL BRING SOME
SLICK TRAVEL AND REDUCED VISIBILITIES TO THE SNOWBELTS OF EASTERN
UPPER/NORTHERN LOWER...WITH SNOW SHOWERS REACHING ALL OTHER LOCALES
AS WELL.
OVERVIEW: WISHING THE EARLY MORNING WATER VAPOR IMAGERY WAS AN APRIL
FOOLS JOKE THIS MORNING AS IMPRESSIVE TROUGH CARVES ITSELF OUT OVER
THE GREAT LAKES REGION. PICKLE LAKE /ONTARIO/ 00Z RAOB SHOWS -42C AT
H5...-25C AT H7 AND -20C AT H8...AN ARCTIC AIRMASS INDEED WITH SURFACE
TEMPS UPSTREAM OF THE GREAT LAKES IN THE LOWER TEENS AND DEWPOINTS
FALLING TO NEAR ZERO. WITH SUBSTANTIAL DOWNSTREAM BLOCKING IN PLACE
FROM GREENLAND SOUTH AND EAST...THE DEVELOPING LONGWAVE TROUGH
OVERHEAD WILL BE IN NO HURRY TO DEPART...WITH ITS IMPACTS DOMINATING
THE SHORT TERM PORTION OF THE FORECAST.
THROUGH DAYBREAK: APX WSR-88D SHOWING LAKE EFFECT SNOW GETTING IT/S
ACT TOGETHER OVER NORTHERN LOWER...WITH PRIMARY BAND FROM ACB-GOV
STRENGTHENING WITH GOOD LAKE SUPERIOR CONNECTION. EXPECT THIS TREND
TO CONTINUE THROUGH DAYBREAK WITH AN INCH OR TWO OF SNOW POSSIBLE
OVER THE BIG 5 OF NW LOWER. WILL COVER THIS BAND WITH AN SPS FOR A
QUICK 1-2 INCHES WHICH WILL LIKELY IMPACT THE MONDAY MORNING
COMMUTE.
WINDS REMAIN QUITE BRISK AS 6MB/6HR PRESSURE RISE CENTER OVER
NORTHERN LAKE SUPERIOR SLIDES SOUTH AND EAST...WITH 15-25 MPH WINDS
THROUGHOUT NORTHERN MICHIGAN...GUSTING AS HIGH AS 35 MPH NEAR THE
COASTS.
TODAY: WITH THE CORE OF THE H5 LOW PUSHING FROM JUST NORTH OF THE
SOO EARLY THIS MORNING TO SOUTHWESTERN QUEBEC BY THSI EVENING...OUR
FLOW ALOFT WILL BACK SLIGHTLY AS THE COLDEST AIR ALOFT MAKES ITS
CLOSEST APPROACH. T8 AROUND -17C WITH WHAT LOOKS TO BE ROBUST
LLEVEL MOISTURE /SEE FOG PRODUCT IMAGERY SHOWING ALL KINDS OF
MOISTURE JUST WEST OF THE H5 LOW CENTER /AND THUS...OVERHEAD
TODAY/. THIS SPELLS CONTINUED LAKE EFFECT SNOW SHOWERS UNDER STRONG
NW WINDS. ALL HIGH RESOLUTION GUIDANCE CONTINUES TO SHOW A DOMINANT
BAND TO START THE DAY...WITH THE HRRR LOOKING TO CAPTURE IT/S
LOCATION BEST /FURTHER WEST THAN THE RAP AND LOCAL WRF/. GIVEN THAT
WE ALREADY HAVE A BAND OF THIS NATURE...SEE NO REASON TO DISAGREE
WITH THE GUDIANCE SUGGESTION...WHICH SHOWS THIS BAND STARTING THE
DAY CENTERED FROM CVX-ACB-GOV PUSHING EAST GIVEN THE AFOREMENTIONED
BACKING FLOW...WITH SOMEWHAT LIGHTER SHSN SURROUNDING IT. THE BAND
LOOKS TO BE QUITE MOBILE THROUGH THE MORNING BEFORE CAPE/SHEAR
NOMOGRAM SUGGESTS THAT BY LATE MORNING IT WIL BEGIN TO BREAK UP AS
OVERLAND INSTABILITY STRENGTHENS. THIS BACKING FLOW SHOULD HELP GET
WESTERN CHIPPEWA/MACKINAC BACK INTO THE ACTION DURING THE DAY AS
WELL.
SNOWFALL: MOBILE SNOWBAND WILL KEEP A LID ON SNOW AMOUNTS...BUT
COULD SEE 1-3" FOR THE DAY TODAY OVER THE NW SNOWBELTS...WITH MOST
OF THIS FALLING BEFORE ACTIVITY BECOMES MORE CELLULAR THIS
AFTERNOON.
WHILE WE LOSE HELP FROM ANY ISALLOBARIC COMPONENT TO THE LLEVEL
WINDS TODAY...H9 WINDS 25-30KTS AND AMPLE LLEVEL MIXING SUGGEST
WINDS 15-25 MPH WINDS WITH GUSTS WELL INTO THE 30S...PARTICULARLY
NEAR THE LAKESHORES AND OVER EASTERN UPPER.
TEMPS WILL BE VERY SLOW TO CLIMB WITH T9 AROUND -10C SUGGESTING MID
20S /SOME 20F BELOW NORMAL/ WILL BE ABOUT ALL WE CAN MUSTER. WITH
THE STRONG WINDS...WIND CHILLS WILL REMAIN IN THE TEENS THROUGH THE
DAY.
HEADLINES: WILL GO AHEAD AND DROP WINTER WEATHER ADVISORY FOR
CHIPPEWA GIVEN LOCATION OF SNOWFALL ACTIVITY WELL WEST OF COUNTY
WITH ACCUMS THUS FAR NOT SUFFICIENT TO WARRANT THE HEADLINE.
AS DISCUSSED ABOVE...HEAVIEST SNOW IS NOW OVER THE BIG 5 IN NW
LOWER...AND WILL MONITOR FOR POTENTIAL HEADLINE THROUGH
DAYBREAK...ALTHOUGH EXPECTATION IS THAT THE BAND WILL BEGIN TO
MOVE...REDUCING THE THREAT OF SIGNIFICANT ACCUMS.
TONIGHT: SYNOPTIC MOISTURE BEGINS TO SLOWLY ERODE WITH TEMPS ALOFT
STEADY OR JUST SLIGHTLY WARING UNDER A FAIRLY STEADY 300-310 FLOW
REGIME. SOME RESIDUAL LAND-BASED CAPE CONTINUES THROUGH THE
OVERNIGHT WHICH MAY NOT FULLY ALLOW THE LAKE EFFECT TO RE-SOLIDIFY
INTO BANDS. SHSN WILL CERTAINLY CONTINUE...HOWEVER...WITH
ADDITIONAL LIGHT ACCUMULATIONS LIKELY. INHERITED ACCUMS OF 1-2
INCHES /PERHAPS 3 OVER WESTERN CHIPPEWA/ LOOK REASONABLE AND HAVE NO
COMPELLING REASON TO DEVIATE SIGNIFICANTLY.
CLOUDS WILL LIKELY KEEP TEMPERATURES FROM FALLING ALL THAT FAR...
GENERALLY IN THE UPPER TEENS TO AROUND 20.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 422 AM EDT MON APR 1 2013
TUESDAY...AS THE SFC HIGH BEGINS TO MOVE INTO THE REGION, THE 850 MB
TEMPERATURES BEGIN TO WARM SLIGHTLY, JUST ENOUGH THAT WE MAY LOSE
THE INSTABILITY NEEDED FOR THE LES. THE MOISTURE IN THE 850-700 MB
LAYER FALLS OFF TO BELOW 60% ON ALL THE MODELS SO WOULD EXPECT LIGHT
SNOW AND FLURRIES. ALTHOUGH WILL HAVE LIKELY POPS SINCE MEASURABLE
SNOW IS EXPECTED FROM THIS PATTERN IN THE MORNING. BY THE AFTERNOON,
THE MOISTURE CONTINUES TO FALL OFF IN THE 850-700 MB LAYER. THE ONE
THING THAT I HAVE NOTICED ABOUT THESE LATE SEASON LES EVENTS IS THAT
IT HAS BECOME HARD FOR THE LOWER END OF THE SOUNDINGS TO SATURATE.
THIS HAS BEEN LEADING TO INVERTED V SOUNDINGS AND REALIZING LESS
SNOW THAN WE WOULD HAVE EVEN A MONTH AGO DURING THE AFTERNOON.
TUESDAY NIGHT...AS THE RIDGE BUILDS INTO THE REGION, THE DRIER AIR
REALLY BEGINS TO OVERWHELM THE REGION, SHUTTING OFF MOST OF THE SNOW
LEAVING ONLY CHANCE POPS IN THE EVENING IN E UPPER, WHILE N LOWER
WILL BE DRY ENOUGH TO NOT HAVE ANY SNOW.
WEDNESDAY...HIGH PRESSURE AT THE SFC AND 500 MB RIDGE MOVES THROUGH
THE REGION SO THAT WE WILL REMAIN DRY FOR THE DAY. OVERNIGHT, A COLD
FRONT AND 500 MB SHORTWAVE TROUGH MOVE INTO THE REGION. THE GFS IS A
LITTLE FASTER THAN THE ECMWF AND NAM. WILL HOLD OFF THE SNOW BY
ALLOWING IT TO JUST TOUCH E UPPER BY 12Z.
EXTENDED (THURSDAY THROUGH SUNDAY)...THURSDAY, THE MODELS DRY THINGS
OUT WITH THE FRONTAL PASSAGE DURING THE DAY. SO WILL HAVE CHANCE
POPS WITH A MIX OF THE RAIN AND SNOW IN E UPPER AND JUST RAIN IN N
LOWER. WITH THE SFC TEMPERATURES IN THE 40S, WOULD NOT BE SURPRISED
IF THIS TURNS OUT TO BE FLURRIES AND SPRINKLES. FRIDAY, THE HIGH
BUILDS INTO THE UPPER GREAT LAKES REGION AND DRIES THINGS OUT AGAIN.
SO DRY WEATHER WILL BE EXPECTED. SATURDAY, THE WARM FRONT WILL BE
MOVING INTO THE REGION. THE ECMWF HAS THE WARM AIR INTO E UPPER SO
THAT IT COULD BE ALL RAIN, WHILE THE GFS HAS IT PLACED A LITTLE
SOUTH. PUT THE DIVIDING LINE AT THE STRAITS SINCE THAT SEEMED TO BE
THE MIDDLE GROUND. WHICH WOULD CONTINUE THROUGH THE NIGHT AS THE
SYSTEM MOVES EAST. SUNDAY, THE LOW MOVES EAST OF THE REGION AND THE
COLD AIR MOVES BACK IN ALLOWING FOR A CHANGE OVER TO SNOW. THE GFS
DRIES THINGS OUT. WILL LEAN TOWARD THE ECMWF WHICH WOULD BE THE
PESSIMISTIC FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 153 PM EDT MON APR 1 2013
MVFR CIGS WILL CONTINUE OVR NRN MI THRU THE TAF PERIOD...A RESULT
OF COLD NORTHWEST FLOW ON THE BACKSIDE OF A SYSTEM WOBBLING OVER
QUEBEC. 850MB TEMPS WILL BE COLD ENOUGH TO GENERATE LAKE SNOWS OVER
NRN MI TAF SITES INTO TUESDAY AFTN. THE MOST PERSISTENT LAKE SNOWS AND
OCCASIONAL IFR VSBYS...WILL INFLUENCE TAF SITES KPLN AND KTVC INTO
TUESDAY AFTN.
&&
.MARINE...
ISSUED AT 422 AM EDT MON APR 1 2013
UPDATE AT 708 AM...DROPPED GALE WARNINGS FOR ALL AREAS SAVE
WHITEFISH BAY AND THE COAST OF NORTHERN LAKE HURON. HIGH END SMALL
CRAFTS SHOULD SUFFICE THROUGH TODAY AND WILL NEED EXTENDING BEYOND
TONIGHT IN SUBSEQUENT UPDATES.
SUMMARY: STRONG NORTHWESTERLY WINDS TO CONTINUE THROUGH TUESDAY AS
LOW PRESSURE MOVES INTO EASTERN CANADA. HIGH PRESSURE ARRIVES BY
MIDWEEK WITH QUIETER CONDITIONS EXPECTED.
HEADLINES: MARGINAL GALES WILL BE ALLOWED TO CONTINUE ALL ZONES
THROUGH THIS EVENING. SMALL CRAFTS WILL CERTAINLY BE NEEDED BEYOND
THIS...WITH ADDITIONAL GALE FORCE GUSTS POSSIBLE AGAIN
TUESDAY...PARTICULARLY FOR NORTHWESTERLY FLOW FAVORED REGIONS.
BEYOND THIS...NEXT ROUND OF SMALL CRAFTS LOOKS LIKELY BY WEDNESDAY
NIGHT OVER LAKE MICHIGAN AS SOUTHWESTERLY WINDS STRENGTHEN AHEAD OF
NEXT APPROACHING SYSTEM.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR
MIZ015>017-019-021>023-027-028.
LH...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LHZ345-346-
349.
GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LHZ347-348.
LM...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LMZ323-341-
342-344>346.
LS...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LSZ322.
GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LSZ321.
&&
$$
UPDATE...SR
SYNOPSIS...JL
SHORT TERM...ARNOTT
LONG TERM...JL
AVIATION...SR
MARINE...ARNOTT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
126 PM EDT MON APR 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM EDT MON APR 1 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR TROF
CENTERED FM HUDSON BAY INTO THE GRT LKS DOWNSTREAM OF UPR RDG OVER
WRN CANADA. 00Z H5/H85 TEMPS ARE AS LO AS -42C/-20C AT THE CORE OF
THE COLDEST AIR AT YPL. CYC NNW FLOW ON THE WRN FLANK OF LO PRES
MOVING SLOWLY E INTO QUEBEC IS DRAWING THIS VERY COLD AIR SWD INTO
THE UPR LKS OVER THE RELATIVELY WARM WATERS OF LAKE SUP...WITH THE
RESULT NMRS LES BANDS AS SHOWN ON MQT RADAR. WELL DEFINED AXIS OF
COLDER CLD TOPS AS SHOWN ON IR STLT IMAGERY IS PRESENT OVER THE E
HALF OF THE LK AND ASSOCIATED WITH FAIRLY SHARP H7-3 QVECTOR CNVGC.
THIS AXIS OF DEEPER MSTR HAS CAUSED SOME ENHANCEMENT TO THE SHSN.
THE HEAVIEST BAND IS STREAMING INTO CENTRAL ALGER COUNTY/SCHOOLCRAFT
COUTY...WITH SOME RETURNS AOA 30 DBZ AT 06Z. SN UNDER THIS BAND IS
LIKELY FALLING AT THE RATE OF AT LEAST AN INCH/HR GIVEN FAVORABLE
LOCATION OF UVV MAX WITHIN DGZ AS SHOWN BY PROFILE FM LOCAL HI RES
MODEL. SINCE THE COLDER CLD TOPS ARE TENDING TO DRIFT TO THE E AND
DRIER LLVL AIR SHOWN ON THE 00Z INL RAOB IS PRESSING TO THE E...
DROPPING THE SFC DEWPT TO NEAR 7F AT IWD AT 06Z...THE INTENSITY OF
THE LES W OF MQT HAS TENDED TO DIMINISH OVER TIME PER RADAR TRENDS
EVEN THOUGH IR STLT IMAGERY INDICATES SOME LES BANDS OVER THE W HALF
OF THE LK THAT HAVE FORMED IN THE PRESENCE OF NOCTURNAL COOLING THAT
IS SO IMPORTANT TO ACHIEVE BETTER LES BAND STRUCTURE THIS TIME OF
YEAR. NW WINDS ARE STILL GUSTING AS HI AS 40 KTS AT STANNARD ROCK AS
OF 06Z...BUT PASSAGE OF PRES RISE CENTER TRAILING THE SFC LO INTO
ONTARIO E OF LK SUP HAS CAUSED A SLOW DIMINISHING TREND TO THE WINDS.
MAIN FCST CONCERNS THIS PACKAGE ARE LES TRENDS/GOIND HEADLINES.
TODAY...MODELS INDICATE UPR TROF AXIS WL DRIFT SLOWLY TO THE E. AREA
OF DEEP LYR QVECTOR CNVGC ENHANCING COMMA HEAD/COLDER CLD TOPS NOW
OVER THE E HALF OF LK SUP IS PROGGED TO DRIFT INTO ONTARIO IN THE
09Z-12Z TIME FRAME. IN CONCERT WITH THE ARRIVAL OF SOME DRYING FM
THE W...LES INTENSITY/COVERAGE SHUD DIMINISH BY SUNRISE. BUT GIVEN
PERSISTENCE OF SGNFT BAND OVER CENTRAL ALGER COUNTY INTO NRN
SCHOOLCRAFT COUNTY IN PERSISTENT NNW FLOW THRU THE EARLY MRNG
HRS...FVRBL SN/WATER RATIOS UNDER COLDEST H85 TEMPS...AND HIER RES
MODEL FCSTS THAT SHOWING FAIRLY HI QPF THRU 18Z WITH DEEPER MSTR
PERSISTING LONGEST IN THAT AREA CLOSER TO DEPARTING LO...OPTED TO
UPGRADE GOING ADVY FOR THOSE ZONES TO AN LES WARNING. OTRW...RISING
H5 HGTS/DEEP LYR QVECTOR CNVGC/SUBSIDENCE IN THE PRESENCE OF DIURNAL
HEATING THAT TENDS TO DISRUPT THE LES PROCESS IN EARLY SPRING SHOULD
CAUSE THE LES BANDS TO WEAKEN AND TRANSITION TO A MORE BLOTCHY
APPEARANCE. SLOWLY BACKING FLOW TOWARD MORE WNW BY THE LATE IN THE
DAY WL ALSO CAUSE AREA OF HEAVIER SHSN TO SHIFT. ADDITIONAL SN
AMOUNTS OVER THE W WL BE LIGHT WITH LLVL DRY AIR HAVING A MORE SGNFT
IMPACT THERE AND MODELS HINTING TOWARD A TRANSITION TO LLVL ACYC
FLOW IN THE AFTN.
TONIGHT...STEADILY RISING HGTS/DEEP LYR QVECTOR CNVGC THAT DROPS
FCST INVRN BASE TOWARD 5-6K FT OVER EVEN THE E SUG LES INTENSITY WL
BE SOMEWHAT DIMINISHED EVEN THOUGH PERSISTENT NW FLOW/H85 TEMPS IN
THE -16 TO -17C RANGE WL ALLOW FOR CONTINUED WDSPRD LES...ESPECIALLY
AFTER MID EVNG WHEN IMPACTS OF DAYTIME HEATING WOULD TEND TO
SUBSIDE. WITH INVRN BASE OVER THE W FALLING TO ARND 4K FT OVER THE
W...SHSN INTENSITY IN THIS AREA WL BE WEAKER WITH SHORTER FETCH/LESS
MODERATION OF UPSTREAM AIRMASS. BUT STILL WENT WITH LIKELY POPS
GIVEN FVRBL NW FLOW/OVERWATER INSTABILITY/NOCTURNAL COOLING THAT WL
ALLOW LES BANDS TO REDEVELOP.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 440 AM EDT MON APR 1 2013
DESPITE ADEQUATE DELTA TS PERSISTING INTO TUESDAY FOR LAKE
EFFECT...SFC-H85 FLOW WILL BECOME INCREASINGLY ANTICYCLONIC THROUGH
THE DAY. IN ADDITION...INVERSION HEIGHTS BEGIN TO FALL OFF
SIGNIFICANTLY BELOW 5KFT. THUS...EXPECT OVERALL COVERAGE AND
INTENSITY OF LAKE EFFECT TO BE ON THE WANE AS THE DAY PROGRESSES.
TEMPERATURES WILL REMAIN WELL BELOW NORMAL WITH A SIGNIFICANT AMOUNT
OF CLOUDINESS DOWNWIND OF LAKE SUPERIOR.
LAKE CLOUDS AND EVEN A FEW FLURRIES WILL PERSIST INTO THE MORNING
WEDNESDAY OVER THE EAST. AS SURFACE RIDGE AXIS MOVES OVERHEAD
THROUGH THE DAY EXPECT SKIES TO BECOME MOSTLY SUNNY AREA WIDE.
TEMPERATURES SHOULD REBOUND BACK ABOVE FREEZING AND EVEN APPROACH 40
ACROSS THE WEST WITH WARM ADVECTION INCREASING DURING THE AFTERNOON
AND MORE SUNSHINE.
MODELS COMING INTO BETTER AGREEMENT WITH THE TIMING OF THE NEXT
SHORTWAVE AND SFC TROUGH EXPECTED TO MOVE ACROSS THE AREA WED
NIGHT/THU. THE TREND HAS BEEN TOWARD QUICKER MOVEMENT WITH THE TROUGH.
SYSTEM IS FAIRLY MOISTURE STARVED...SO DESPITE PRECIP TYPE BEING A
CHALLENGE BETWEEN RAIN AND SNOW...AMOUNTS WILL BE LIGHT ENOUGH TO BE
PRETTY INSIGNIFICANT. COLD ADVECTION BEHIND THE TROUGH SHOULD PUSH
85H TEMPS BACK DOWN TO THE -10 TO -14C RANGE BY FRIDAY. PROBABLY NOT
QUITE COLD ENOUGH FOR LAKE EFFECT THIS TIME AROUND...BUT COLDER AIR
WILL KEEP DAYTIME TEMPS BELOW AVERAGE ONLY IN THE 30S.
FORECAST FOR NEXT WEEKEND STILL PRETTY CHALLENGING...BUT MODELS
SHOWING SOME SIGNS THAT THEY ARE TRYING TO CONVERGE ON A MORE
PROBABLE OUTCOME. SHORTWAVE ENERGY AND ASSOCIATED SURFACE LOW MOVING
OUT OF THE PLAINS LOOKING LIKE THEY MAY NOW TRACK THROUGH THE LOWER
LAKES WHICH WOULD STILL RESULT IN SOME LIGHT SNOWFALL ACROSS
SOUTHERN AREAS SATURDAY INTO SUNDAY BUT SPARE THE AREA FROM A MORE
SIGNIFICANT STORM. IT IS STILL SOMETHING TO KEEP AN EYE ON AS WE
HEAD THROUGH THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 125 PM EDT MON APR 1 2013
DRY AIR MOVING ACROSS LAKE SUPERIOR SHOULD HELP TO KEEP CMX AND IWD
AT OR ABOVE MVFR THROUGH THE TAF PERIOD. CEILINGS SHOULD REMAIN AT
OR ABOVE 3KFT FOR EACH TAF SITE...WITH KSAW POSSIBLY REACHING VFR
CEILINGS THIS AFTERNOON AND EVENING AS WNW WINDS ALLOW FOR
DOWNSLOPING OVER THAT AREA. VISIBILITIES ARE A BIT TRICKY AS
INTERMITTENT SNOW SHOWERS PASS OVER EACH TAF SITE...OCCASIONALLY
REDUCING VISIBILITY TO MVFR OR LOWER AT TIMES...ESPECIALLY OVER THE
KEWEENAW WHERE WINDS MAY REMAIN GUSTY THROUGH THE TAF PERIOD
INCREASING THE POTENTIAL FOR BLOWING SNOW. WINDS ARE EXPECTED TO
DECREASE OVER THE REMAINING TAF SITES AS PRESSURE GRADIENT IS
REDUCED AS THE SURFACE LOW SHIFTS TO CENTRAL QUEBEC BY TUESDAY
MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 440 AM EDT MON APR 1 2013
AS LO PRES OVER SE CANADA CONTINUES TO THE E AND THE PRES GRADIENT
WEAKENS...EXPECT NW WINDS TO SLOWLY DIMINISH AND BELOW GALE FORCE
OVER THE CENTRAL BY MID MORNING...SO HASTENED THE ENDING OF THE GALE
WARNINGS FOR THIS AREA. ALTHOUG NW GALES TO 35 KTS WILL CONTINUE
LONGER OVER THE E INTO THIS EVENING...ENDED THE GALES FOR THAT AREA
EARLIER AS WELL. WINDS/WAVES WILL BE SUFFICIENT TO MAINTAIN FREEZING
SPRAY OVER AT LEAST THE E HALF THRU TONIGHT.
WINDS WILL REMAIN PRETTY GUSTY UP TO 30 KNOTS OVER THE EASTERN LAKE
THROUGH THE DAY ON TUESDAY...BUT AS SURFACE RIDGE AXIS PUSHES IN
FROM THE WEST PRESSURE GRADIENT WILL RELAX AND WINDS WILL DIMINISH
DURING THE EVENING. UNTIL THAT TIME...FREEZING SPRAY SHOULD CONTINUE
ACROSS THE EASTERN LAKE. AFTER A BRIEF RESPITE ON
WEDNESDAY...SOUTHWESTERLY WINDS UP TO 25 KNOTS AHEAD OF THE NEXT
TROUGH CROSSING THE LAKE WILL INCREASE WEDNESDAY NIGHT INTO EARLY
THURSDAY BEFORE SHIFTING TO THE NORTHWEST DURING THE DAY THURSDAY
INTO THURSDAY NIGHT. WINDS FOR FRIDAY INTO NEXT WEEKEND SHOULD BE
BELOW 20 KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR
MIZ006-085.
WINTER WEATHER ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR MIZ007.
LAKE SUPERIOR...
GALE WARNING UNTIL 2 AM EDT TUESDAY FOR LSZ250-251-266-267.
GALE WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR LSZ249.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...MZ
AVIATION...KEC
MARINE...KC/MZ
AREA FORECAST DISCUSSION
NWS GAYLORD MI
952 AM EDT MON APR 1 2013
.SYNOPSIS...
ISSUED AT 422 AM EDT MON APR 1 2013
A SYSTEM IN QUEBEC IS BRINGING COLD AIR AND NORTHWEST WINDS TO THE
STATE TODAY. THE COLDER AIR IS PRODUCING LAKE EFFECT SNOW SHOWERS
WHICH WILL PERSIST OVER NORTHERN MICHIGAN THROUGH TUESDAY. THE MOST
PERSISTENT SNOW SHOWERS WITH THE BEST CHANCE OF ACCUMULATION WILL BE
IN THE TYPICAL SNOW BELTS OF NORTHWEST LOWER AND EAST UPPER
MICHIGAN.
&&
.UPDATE...
ISSUED AT 951 AM EDT MON APR 1 2013
THE STORM SYSTEM WHICH SWEPT ACROSS THE GREAT LAKES THIS WEEKEND...
HAS PUSHED EAST OF THE STATE AND WILL CONTINUE TO LIFT INTO QUEBEC
THROUGH TUESDAY. COLD 850MB TEMPS...NORTHWEST WINDS AND LAKE EFFECT
SNOWS HAD ALREADY BEGUN TO FILTER INTO NRN MI EARLIER THIS MORNING.
850MB TEMPS DROPPED FROM AROUND 0C SUNDAY AFTERNOON TO ARND -16C BY
12Z THIS MORNING.
AS FOR THE REST OF THE AFTN...THE PARAMETERS WHICH ARE CURRENTLY
GENERATING LAKE INDUCED SNOWS OVER THE WRN LAKES...ARE NOT EXPECTED
TO CHANGE MUCH THROUGH 21Z. 850MB TEMPS WILL LINGER AROUND -16C AS
THE AXIS OF THE SFC AND 500MB FEATURES PUSH FURTHER EAST OF THE REGION
THIS AFTERNOON. SFC-850MB WINDS WOBBLE DURING THE AFTN...THOUGH
REMAIN GENERALLY NW (300-320) WHILE INVERSION HEIGHTS LINGER AROUND
5K FT. OVERALL EXPECT WIDESPREAD LAKE SNOWS TO CONT OVER THE WRN
LAKES THROUGH THE AFTN...THOUGH WITH THE HIGH SUN ANGLE...EXPECT
DOMINATE SNOW BANDS TO BECOME A LEAST SLIGHTLY DISRUPTED THROUGH THE
REST OF THE MORNING. OVERALL WILL KEEP CONT TO MENTION LAKE SNOWS
THROUGH THE AFTN. WILL MENTION UP TO 2 INCHES OF SNOW POSSIBLE IN
FAVORED SNOW BELTS...AND WILL EXTEND HEADLINES THRU THE AFTN.
UPDATE ISSUED AT 708 AM EDT MON APR 1 2013
CHANGES THIS HOUR: ADDITIONAL /UPWARD/ ADJUSTMENTS TO SNOWFALL AS
A BAND OF NEARLY 5 INCHES HAS OCCURRED OVER EXTREME SW OTSEGO
COUNTY AND NW CRAWFORD COUNTY. BANDING IS MAKING ITS EXPECTED
SHIFT EAST...AND IS BEGINNING TO BECOME A LITTLE MORE DIFFUSE.
EXPECT WE/VE GOT 2-3 MORE HOURS OF DECENT ACCUMS BEFORE THINGS
WIND DOWN. ADVISORY CONTINUES TO LOOK GOOD AND WILL MAKE NO
CHANGES TO THIS.
UPDATE ISSUED AT 519 AM EDT MON APR 1 2013
CHANGES THIS HOUR: BAND HESITATED LONG ENOUGH FOR ME...AND HAVE
ISSUED A WINTER WEATHER ADVISORY FOR 4 OF THE BIG 5 /EXCLUDED
KALKASKA/ THROUGH NOON. RADAR ESTIMATES HAVE REACHED 2-3" IN
SPOTS...WITH BIG FLUFFY FLAKES FALLING HERE AT THE OFFICE
INDICATING 20:1 RATIOS LOOK GOOD. WINDS AMPLE TO BLOW THIS SNOW
AROUND AS WELL. EXPECT 2-4 OVER THE NEXT FEW HOURS AS BAND STARTS
TO EDGE EAST FROM ITS CURRENT LOCATION...BEFORE LIKELY BREAKING UP
BY LATE MORNING.
NO OTHER CHANGES ATTM.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 422 AM EDT MON APR 1 2013
HIGH IMPACT WEATHER POTENTIAL: GALE FORCE WIND GUSTS POSSIBLE ALL
MARINE WATERS THROUGH TODAY. SNOW/BLOWING SNOW WILL BRING SOME
SLICK TRAVEL AND REDUCED VISIBILITIES TO THE SNOWBELTS OF EASTERN
UPPER/NORTHERN LOWER...WITH SNOW SHOWERS REACHING ALL OTHER LOCALES
AS WELL.
OVERVIEW: WISHING THE EARLY MORNING WATER VAPOR IMAGERY WAS AN APRIL
FOOLS JOKE THIS MORNING AS IMPRESSIVE TROUGH CARVES ITSELF OUT OVER
THE GREAT LAKES REGION. PICKLE LAKE /ONTARIO/ 00Z RAOB SHOWS -42C AT
H5...-25C AT H7 AND -20C AT H8...AN ARCTIC AIRMASS INDEED WITH SURFACE
TEMPS UPSTREAM OF THE GREAT LAKES IN THE LOWER TEENS AND DEWPOINTS
FALLING TO NEAR ZERO. WITH SUBSTANTIAL DOWNSTREAM BLOCKING IN PLACE
FROM GREENLAND SOUTH AND EAST...THE DEVELOPING LONGWAVE TROUGH
OVERHEAD WILL BE IN NO HURRY TO DEPART...WITH ITS IMPACTS DOMINATING
THE SHORT TERM PORTION OF THE FORECAST.
THROUGH DAYBREAK: APX WSR-88D SHOWING LAKE EFFECT SNOW GETTING IT/S
ACT TOGETHER OVER NORTHERN LOWER...WITH PRIMARY BAND FROM ACB-GOV
STRENGTHENING WITH GOOD LAKE SUPERIOR CONNECTION. EXPECT THIS TREND
TO CONTINUE THROUGH DAYBREAK WITH AN INCH OR TWO OF SNOW POSSIBLE
OVER THE BIG 5 OF NW LOWER. WILL COVER THIS BAND WITH AN SPS FOR A
QUICK 1-2 INCHES WHICH WILL LIKELY IMPACT THE MONDAY MORNING
COMMUTE.
WINDS REMAIN QUITE BRISK AS 6MB/6HR PRESSURE RISE CENTER OVER
NORTHERN LAKE SUPERIOR SLIDES SOUTH AND EAST...WITH 15-25 MPH WINDS
THROUGHOUT NORTHERN MICHIGAN...GUSTING AS HIGH AS 35 MPH NEAR THE
COASTS.
TODAY: WITH THE CORE OF THE H5 LOW PUSHING FROM JUST NORTH OF THE
SOO EARLY THIS MORNING TO SOUTHWESTERN QUEBEC BY THSI EVENING...OUR
FLOW ALOFT WILL BACK SLIGHTLY AS THE COLDEST AIR ALOFT MAKES ITS
CLOSEST APPROACH. T8 AROUND -17C WITH WHAT LOOKS TO BE ROBUST
LLEVEL MOISTURE /SEE FOG PRODUCT IMAGERY SHOWING ALL KINDS OF
MOISTURE JUST WEST OF THE H5 LOW CENTER /AND THUS...OVERHEAD
TODAY/. THIS SPELLS CONTINUED LAKE EFFECT SNOW SHOWERS UNDER STRONG
NW WINDS. ALL HIGH RESOLUTION GUIDANCE CONTINUES TO SHOW A DOMINANT
BAND TO START THE DAY...WITH THE HRRR LOOKING TO CAPTURE IT/S
LOCATION BEST /FURTHER WEST THAN THE RAP AND LOCAL WRF/. GIVEN THAT
WE ALREADY HAVE A BAND OF THIS NATURE...SEE NO REASON TO DISAGREE
WITH THE GUDIANCE SUGGESTION...WHICH SHOWS THIS BAND STARTING THE
DAY CENTERED FROM CVX-ACB-GOV PUSHING EAST GIVEN THE AFOREMENTIONED
BACKING FLOW...WITH SOMEWHAT LIGHTER SHSN SURROUNDING IT. THE BAND
LOOKS TO BE QUITE MOBILE THROUGH THE MORNING BEFORE CAPE/SHEAR
NOMOGRAM SUGGESTS THAT BY LATE MORNING IT WIL BEGIN TO BREAK UP AS
OVERLAND INSTABILITY STRENGTHENS. THIS BACKING FLOW SHOULD HELP GET
WESTERN CHIPPEWA/MACKINAC BACK INTO THE ACTION DURING THE DAY AS
WELL.
SNOWFALL: MOBILE SNOWBAND WILL KEEP A LID ON SNOW AMOUNTS...BUT
COULD SEE 1-3" FOR THE DAY TODAY OVER THE NW SNOWBELTS...WITH MOST
OF THIS FALLING BEFORE ACTIVITY BECOMES MORE CELLULAR THIS
AFTERNOON.
WHILE WE LOSE HELP FROM ANY ISALLOBARIC COMPONENT TO THE LLEVEL
WINDS TODAY...H9 WINDS 25-30KTS AND AMPLE LLEVEL MIXING SUGGEST
WINDS 15-25 MPH WINDS WITH GUSTS WELL INTO THE 30S...PARTICULARLY
NEAR THE LAKESHORES AND OVER EASTERN UPPER.
TEMPS WILL BE VERY SLOW TO CLIMB WITH T9 AROUND -10C SUGGESTING MID
20S /SOME 20F BELOW NORMAL/ WILL BE ABOUT ALL WE CAN MUSTER. WITH
THE STRONG WINDS...WIND CHILLS WILL REMAIN IN THE TEENS THROUGH THE
DAY.
HEADLINES: WILL GO AHEAD AND DROP WINTER WEATHER ADVISORY FOR
CHIPPEWA GIVEN LOCATION OF SNOWFALL ACTIVITY WELL WEST OF COUNTY
WITH ACCUMS THUS FAR NOT SUFFICIENT TO WARRANT THE HEADLINE.
AS DISCUSSED ABOVE...HEAVIEST SNOW IS NOW OVER THE BIG 5 IN NW
LOWER...AND WILL MONITOR FOR POTENTIAL HEADLINE THROUGH
DAYBREAK...ALTHOUGH EXPECTATION IS THAT THE BAND WILL BEGIN TO
MOVE...REDUCING THE THREAT OF SIGNIFICANT ACCUMS.
TONIGHT: SYNOPTIC MOISTURE BEGINS TO SLOWLY ERODE WITH TEMPS ALOFT
STEADY OR JUST SLIGHTLY WARING UNDER A FAIRLY STEADY 300-310 FLOW
REGIME. SOME RESIDUAL LAND-BASED CAPE CONTINUES THROUGH THE
OVERNIGHT WHICH MAY NOT FULLY ALLOW THE LAKE EFFECT TO RE-SOLIDIFY
INTO BANDS. SHSN WILL CERTAINLY CONTINUE...HOWEVER...WITH
ADDITIONAL LIGHT ACCUMULATIONS LIKELY. INHERITED ACCUMS OF 1-2
INCHES /PERHAPS 3 OVER WESTERN CHIPPEWA/ LOOK REASONABLE AND HAVE NO
COMPELLING REASON TO DEVIATE SIGNIFICANTLY.
CLOUDS WILL LIKELY KEEP TEMPERATURES FROM FALLING ALL THAT FAR...
GENERALLY IN THE UPPER TEENS TO AROUND 20.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 422 AM EDT MON APR 1 2013
TUESDAY...AS THE SFC HIGH BEGINS TO MOVE INTO THE REGION, THE 850 MB
TEMPERATURES BEGIN TO WARM SLIGHTLY, JUST ENOUGH THAT WE MAY LOSE
THE INSTABILITY NEEDED FOR THE LES. THE MOISTURE IN THE 850-700 MB
LAYER FALLS OFF TO BELOW 60% ON ALL THE MODELS SO WOULD EXPECT LIGHT
SNOW AND FLURRIES. ALTHOUGH WILL HAVE LIKELY POPS SINCE MEASURABLE
SNOW IS EXPECTED FROM THIS PATTERN IN THE MORNING. BY THE AFTERNOON,
THE MOISTURE CONTINUES TO FALL OFF IN THE 850-700 MB LAYER. THE ONE
THING THAT I HAVE NOTICED ABOUT THESE LATE SEASON LES EVENTS IS THAT
IT HAS BECOME HARD FOR THE LOWER END OF THE SOUNDINGS TO SATURATE.
THIS HAS BEEN LEADING TO INVERTED V SOUNDINGS AND REALIZING LESS
SNOW THAN WE WOULD HAVE EVEN A MONTH AGO DURING THE AFTERNOON.
TUESDAY NIGHT...AS THE RIDGE BUILDS INTO THE REGION, THE DRIER AIR
REALLY BEGINS TO OVERWHELM THE REGION, SHUTTING OFF MOST OF THE SNOW
LEAVING ONLY CHANCE POPS IN THE EVENING IN E UPPER, WHILE N LOWER
WILL BE DRY ENOUGH TO NOT HAVE ANY SNOW.
WEDNESDAY...HIGH PRESSURE AT THE SFC AND 500 MB RIDGE MOVES THROUGH
THE REGION SO THAT WE WILL REMAIN DRY FOR THE DAY. OVERNIGHT, A COLD
FRONT AND 500 MB SHORTWAVE TROUGH MOVE INTO THE REGION. THE GFS IS A
LITTLE FASTER THAN THE ECMWF AND NAM. WILL HOLD OFF THE SNOW BY
ALLOWING IT TO JUST TOUCH E UPPER BY 12Z.
EXTENDED (THURSDAY THROUGH SUNDAY)...THURSDAY, THE MODELS DRY THINGS
OUT WITH THE FRONTAL PASSAGE DURING THE DAY. SO WILL HAVE CHANCE
POPS WITH A MIX OF THE RAIN AND SNOW IN E UPPER AND JUST RAIN IN N
LOWER. WITH THE SFC TEMPERATURES IN THE 40S, WOULD NOT BE SURPRISED
IF THIS TURNS OUT TO BE FLURRIES AND SPRINKLES. FRIDAY, THE HIGH
BUILDS INTO THE UPPER GREAT LAKES REGION AND DRIES THINGS OUT AGAIN.
SO DRY WEATHER WILL BE EXPECTED. SATURDAY, THE WARM FRONT WILL BE
MOVING INTO THE REGION. THE ECMWF HAS THE WARM AIR INTO E UPPER SO
THAT IT COULD BE ALL RAIN, WHILE THE GFS HAS IT PLACED A LITTLE
SOUTH. PUT THE DIVIDING LINE AT THE STRAITS SINCE THAT SEEMED TO BE
THE MIDDLE GROUND. WHICH WOULD CONTINUE THROUGH THE NIGHT AS THE
SYSTEM MOVES EAST. SUNDAY, THE LOW MOVES EAST OF THE REGION AND THE
COLD AIR MOVES BACK IN ALLOWING FOR A CHANGE OVER TO SNOW. THE GFS
DRIES THINGS OUT. WILL LEAN TOWARD THE ECMWF WHICH WOULD BE THE
PESSIMISTIC FORECAST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 708 AM EDT MON APR 1 2013
SUMMARY: STRONG LOW PRESSURE...DEPARTING INTO EASTERN CANADA WILL
CAUSE STRONG NORTHWEST WINDS THROUGH THE UPCOMING TAF PERIOD...WITH
OCCASIONAL LAKE EFFECT SNOW SHOWERS IMPACTING THE TAF SITES.
RESTRICTIONS: LAKE EFFECT SNOW BANDS DOING A GOOD JOB AVOIDING THE
TERMINALS EARLY THIS MORNING. PRIMARY BAND FROM CHARLEVOIX TO
GAYLORD WILL START TO BREAK UP AS IT SHIFTS EAST...BUT WILL LIKELY
BRING A PERIOD OF MVFR/IFR TO PLN FOR A TIME THIS MORNING. LAKE
EFFECT SHSN WILL CONTINUE THIS AFTERNOON...BUT IN A MORE
CELLULAR/SCATTERED FASHION...WHICH WILL LIKELY ALLOW TVC/MBL/APN TO
REMAIN VFR WHILE PLN DEALS WITH OCCASIONAL MVFR VSBYS-CIGS /WITH
PERHAPS VERY BRIEF IFR VSBYS/. SHSN ACTIVITY WILL CONTINUE
TONIGHT...BUT WILL AVOID INCLUDING MVFR/IFR RESTRICTIONS IN THIS TAF
PACKAGE AS THESE SHSN WILL BE SHORT-LIVED AND CONFIDENCE NOT HIGH
ENOUGH ON LOCATION /ALTHOUGH BEST CHANCES WILL LIKELY CONTINUE TO BE
AT PLN/ TO INCLUDE.
WINDS: NORTHWEST WINDS WILL REACH 18G28KTS FOR THE DAY TODAY BEFORE
DIMINISHING TO 10-15KTS TONIGHT.
&&
.MARINE...
ISSUED AT 422 AM EDT MON APR 1 2013
UPDATE AT 708 AM...DROPPED GALE WARNINGS FOR ALL AREAS SAVE
WHITEFISH BAY AND THE COAST OF NORTHERN LAKE HURON. HIGH END SMALL
CRAFTS SHOULD SUFFICE THROUGH TODAY AND WILL NEED EXTENDING BEYOND
TONIGHT IN SUBSEQUENT UPDATES.
SUMMARY: STRONG NORTHWESTERLY WINDS TO CONTINUE THROUGH TUESDAY AS
LOW PRESSURE MOVES INTO EASTERN CANADA. HIGH PRESSURE ARRIVES BY
MIDWEEK WITH QUIETER CONDITIONS EXPECTED.
HEADLINES: MARGINAL GALES WILL BE ALLOWED TO CONTINUE ALL ZONES
THROUGH THIS EVENING. SMALL CRAFTS WILL CERTAINLY BE NEEDED BEYOND
THIS...WITH ADDITIONAL GALE FORCE GUSTS POSSIBLE AGAIN
TUESDAY...PARTICULARLY FOR NORTHWESTERLY FLOW FAVORED REGIONS.
BEYOND THIS...NEXT ROUND OF SMALL CRAFTS LOOKS LIKELY BY WEDNESDAY
NIGHT OVER LAKE MICHIGAN AS SOUTHWESTERLY WINDS STRENGTHEN AHEAD OF
NEXT APPROACHING SYSTEM.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL NOON EDT TODAY FOR MIZ019-021-022-
028.
LH...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LHZ345-346-
349.
GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LHZ347-348.
LM...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LMZ323-341-
342-344>346.
LS...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LSZ322.
GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LSZ321.
&&
$$
UPDATE...SR
SYNOPSIS...JL
SHORT TERM...ARNOTT
LONG TERM...JL
AVIATION...ARNOTT
MARINE...ARNOTT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
728 AM EDT MON APR 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM EDT MON APR 1 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR TROF
CENTERED FM HUDSON BAY INTO THE GRT LKS DOWNSTREAM OF UPR RDG OVER
WRN CANADA. 00Z H5/H85 TEMPS ARE AS LO AS -42C/-20C AT THE CORE OF
THE COLDEST AIR AT YPL. CYC NNW FLOW ON THE WRN FLANK OF LO PRES
MOVING SLOWLY E INTO QUEBEC IS DRAWING THIS VERY COLD AIR SWD INTO
THE UPR LKS OVER THE RELATIVELY WARM WATERS OF LAKE SUP...WITH THE
RESULT NMRS LES BANDS AS SHOWN ON MQT RADAR. WELL DEFINED AXIS OF
COLDER CLD TOPS AS SHOWN ON IR STLT IMAGERY IS PRESENT OVER THE E
HALF OF THE LK AND ASSOCIATED WITH FAIRLY SHARP H7-3 QVECTOR CNVGC.
THIS AXIS OF DEEPER MSTR HAS CAUSED SOME ENHANCEMENT TO THE SHSN.
THE HEAVIEST BAND IS STREAMING INTO CENTRAL ALGER COUNTY/SCHOOLCRAFT
COUTY...WITH SOME RETURNS AOA 30 DBZ AT 06Z. SN UNDER THIS BAND IS
LIKELY FALLING AT THE RATE OF AT LEAST AN INCH/HR GIVEN FAVORABLE
LOCATION OF UVV MAX WITHIN DGZ AS SHOWN BY PROFILE FM LOCAL HI RES
MODEL. SINCE THE COLDER CLD TOPS ARE TENDING TO DRIFT TO THE E AND
DRIER LLVL AIR SHOWN ON THE 00Z INL RAOB IS PRESSING TO THE E...
DROPPING THE SFC DEWPT TO NEAR 7F AT IWD AT 06Z...THE INTENSITY OF
THE LES W OF MQT HAS TENDED TO DIMINISH OVER TIME PER RADAR TRENDS
EVEN THOUGH IR STLT IMAGERY INDICATES SOME LES BANDS OVER THE W HALF
OF THE LK THAT HAVE FORMED IN THE PRESENCE OF NOCTURNAL COOLING THAT
IS SO IMPORTANT TO ACHIEVE BETTER LES BAND STRUCTURE THIS TIME OF
YEAR. NW WINDS ARE STILL GUSTING AS HI AS 40 KTS AT STANNARD ROCK AS
OF 06Z...BUT PASSAGE OF PRES RISE CENTER TRAILING THE SFC LO INTO
ONTARIO E OF LK SUP HAS CAUSED A SLOW DIMINISHING TREND TO THE WINDS.
MAIN FCST CONCERNS THIS PACKAGE ARE LES TRENDS/GOIND HEADLINES.
TODAY...MODELS INDICATE UPR TROF AXIS WL DRIFT SLOWLY TO THE E. AREA
OF DEEP LYR QVECTOR CNVGC ENHANCING COMMA HEAD/COLDER CLD TOPS NOW
OVER THE E HALF OF LK SUP IS PROGGED TO DRIFT INTO ONTARIO IN THE
09Z-12Z TIME FRAME. IN CONCERT WITH THE ARRIVAL OF SOME DRYING FM
THE W...LES INTENSITY/COVERAGE SHUD DIMINISH BY SUNRISE. BUT GIVEN
PERSISTENCE OF SGNFT BAND OVER CENTRAL ALGER COUNTY INTO NRN
SCHOOLCRAFT COUNTY IN PERSISTENT NNW FLOW THRU THE EARLY MRNG
HRS...FVRBL SN/WATER RATIOS UNDER COLDEST H85 TEMPS...AND HIER RES
MODEL FCSTS THAT SHOWING FAIRLY HI QPF THRU 18Z WITH DEEPER MSTR
PERSISTING LONGEST IN THAT AREA CLOSER TO DEPARTING LO...OPTED TO
UPGRADE GOING ADVY FOR THOSE ZONES TO AN LES WARNING. OTRW...RISING
H5 HGTS/DEEP LYR QVECTOR CNVGC/SUBSIDENCE IN THE PRESENCE OF DIURNAL
HEATING THAT TENDS TO DISRUPT THE LES PROCESS IN EARLY SPRING SHOULD
CAUSE THE LES BANDS TO WEAKEN AND TRANSITION TO A MORE BLOTCHY
APPEARANCE. SLOWLY BACKING FLOW TOWARD MORE WNW BY THE LATE IN THE
DAY WL ALSO CAUSE AREA OF HEAVIER SHSN TO SHIFT. ADDITIONAL SN
AMOUNTS OVER THE W WL BE LIGHT WITH LLVL DRY AIR HAVING A MORE SGNFT
IMPACT THERE AND MODELS HINTING TOWARD A TRANSITION TO LLVL ACYC
FLOW IN THE AFTN.
TONIGHT...STEADILY RISING HGTS/DEEP LYR QVECTOR CNVGC THAT DROPS
FCST INVRN BASE TOWARD 5-6K FT OVER EVEN THE E SUG LES INTENSITY WL
BE SOMEWHAT DIMINISHED EVEN THOUGH PERSISTENT NW FLOW/H85 TEMPS IN
THE -16 TO -17C RANGE WL ALLOW FOR CONTINUED WDSPRD LES...ESPECIALLY
AFTER MID EVNG WHEN IMPACTS OF DAYTIME HEATING WOULD TEND TO
SUBSIDE. WITH INVRN BASE OVER THE W FALLING TO ARND 4K FT OVER THE
W...SHSN INTENSITY IN THIS AREA WL BE WEAKER WITH SHORTER FETCH/LESS
MODERATION OF UPSTREAM AIRMASS. BUT STILL WENT WITH LIKELY POPS
GIVEN FVRBL NW FLOW/OVERWATER INSTABILITY/NOCTURNAL COOLING THAT WL
ALLOW LES BANDS TO REDEVELOP.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 440 AM EDT MON APR 1 2013
DESPITE ADEQUATE DELTA TS PERSISTING INTO TUESDAY FOR LAKE
EFFECT...SFC-H85 FLOW WILL BECOME INCREASINGLY ANTICYCLONIC THROUGH
THE DAY. IN ADDITION...INVERSION HEIGHTS BEGIN TO FALL OFF
SIGNIFICANTLY BELOW 5KFT. THUS...EXPECT OVERALL COVERAGE AND
INTENSITY OF LAKE EFFECT TO BE ON THE WANE AS THE DAY PROGRESSES.
TEMPERATURES WILL REMAIN WELL BELOW NORMAL WITH A SIGNIFICANT AMOUNT
OF CLOUDINESS DOWNWIND OF LAKE SUPERIOR.
LAKE CLOUDS AND EVEN A FEW FLURRIES WILL PERSIST INTO THE MORNING
WEDNESDAY OVER THE EAST. AS SURFACE RIDGE AXIS MOVES OVERHEAD
THROUGH THE DAY EXPECT SKIES TO BECOME MOSTLY SUNNY AREA WIDE.
TEMPERATURES SHOULD REBOUND BACK ABOVE FREEZING AND EVEN APPROACH 40
ACROSS THE WEST WITH WARM ADVECTION INCREASING DURING THE AFTERNOON
AND MORE SUNSHINE.
MODELS COMING INTO BETTER AGREEMENT WITH THE TIMING OF THE NEXT
SHORTWAVE AND SFC TROUGH EXPECTED TO MOVE ACROSS THE AREA WED
NIGHT/THU. THE TREND HAS BEEN TOWARD QUICKER MOVEMENT WITH THE TROUGH.
SYSTEM IS FAIRLY MOISTURE STARVED...SO DESPITE PRECIP TYPE BEING A
CHALLENGE BETWEEN RAIN AND SNOW...AMOUNTS WILL BE LIGHT ENOUGH TO BE
PRETTY INSIGNIFICANT. COLD ADVECTION BEHIND THE TROUGH SHOULD PUSH
85H TEMPS BACK DOWN TO THE -10 TO -14C RANGE BY FRIDAY. PROBABLY NOT
QUITE COLD ENOUGH FOR LAKE EFFECT THIS TIME AROUND...BUT COLDER AIR
WILL KEEP DAYTIME TEMPS BELOW AVERAGE ONLY IN THE 30S.
FORECAST FOR NEXT WEEKEND STILL PRETTY CHALLENGING...BUT MODELS
SHOWING SOME SIGNS THAT THEY ARE TRYING TO CONVERGE ON A MORE
PROBABLE OUTCOME. SHORTWAVE ENERGY AND ASSOCIATED SURFACE LOW MOVING
OUT OF THE PLAINS LOOKING LIKE THEY MAY NOW TRACK THROUGH THE LOWER
LAKES WHICH WOULD STILL RESULT IN SOME LIGHT SNOWFALL ACROSS
SOUTHERN AREAS SATURDAY INTO SUNDAY BUT SPARE THE AREA FROM A MORE
SIGNIFICANT STORM. IT IS STILL SOMETHING TO KEEP AN EYE ON AS WE
HEAD THROUGH THE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 726 AM EDT MON APR 1 2013
ALTHOUGH NW FLOW OF COLD AIR FLOWING ACRS LK SUP MAY CAUSE MVFR
CONDITIONS AT TIMES AT IWD/CMX WITH UPSLOPE WIND COMPONENT...EXPECT
VFR CONDITIONS TO PREDOMINATE AT THESE SITES GIVEN VERY DRY NATURE
OF THE LLVLS UPSTREAM AS SHOWN ON THE 00Z INL/YQD RAOBS. WITH A
DOWNSLOPE WIND COMPONENT AND THIS DRYNESS...SAW HAS THE BEST SHOT TO
REMAIN VFR FOR THE ENTIRE TIME. GUSTY NW WINDS WL LINGER...
ESPECIALLY AT THE MORE EXPOSED CMX LOCATION.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 440 AM EDT MON APR 1 2013
AS LO PRES OVER SE CANADA CONTINUES TO THE E AND THE PRES GRADIENT
WEAKENS...EXPECT NW WINDS TO SLOWLY DIMINISH AND BELOW GALE FORCE
OVER THE CENTRAL BY MID MORNING...SO HASTENED THE ENDING OF THE GALE
WARNINGS FOR THIS AREA. ALTHOUG NW GALES TO 35 KTS WILL CONTINUE
LONGER OVER THE E INTO THIS EVENING...ENDED THE GALES FOR THAT AREA
EARLIER AS WELL. WINDS/WAVES WILL BE SUFFICIENT TO MAINTAIN FREEZING
SPRAY OVER AT LEAST THE E HALF THRU TONIGHT.
WINDS WILL REMAIN PRETTY GUSTY UP TO 30 KNOTS OVER THE EASTERN LAKE
THROUGH THE DAY ON TUESDAY...BUT AS SURFACE RIDGE AXIS PUSHES IN
FROM THE WEST PRESSURE GRADIENT WILL RELAX AND WINDS WILL DIMINISH
DURING THE EVENING. UNTIL THAT TIME...FREEZING SPRAY SHOULD CONTINUE
ACROSS THE EASTERN LAKE. AFTER A BRIEF RESPITE ON
WEDNESDAY...SOUTHWESTERLY WINDS UP TO 25 KNOTS AHEAD OF THE NEXT
TROUGH CROSSING THE LAKE WILL INCREASE WEDNESDAY NIGHT INTO EARLY
THURSDAY BEFORE SHIFTING TO THE NORTHWEST DURING THE DAY THURSDAY
INTO THURSDAY NIGHT. WINDS FOR FRIDAY INTO NEXT WEEKEND SHOULD BE
BELOW 20 KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR MIZ007.
LAKE EFFECT SNOW WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR
MIZ006-085.
LAKE SUPERIOR...
GALE WARNING UNTIL 2 AM EDT TUESDAY FOR LSZ250-251-266-267.
GALE WARNING UNTIL NOON EDT TODAY FOR LSZ265.
GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR LSZ244-245-264.
GALE WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR LSZ249.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...MZ
AVIATION...KC
MARINE...KC/MZ
AREA FORECAST DISCUSSION...UPDATED
NWS GAYLORD MI
716 AM EDT MON APR 1 2013
.SYNOPSIS...
ISSUED AT 422 AM EDT MON APR 1 2013
A SYSTEM IN QUEBEC IS BRINGING COLD AIR AND NORTHWEST WINDS TO THE
STATE TODAY. THE COLDER AIR IS PRODUCING LAKE EFFECT SNOW SHOWERS
WHICH WILL PERSIST OVER NORTHERN MICHIGAN THROUGH TUESDAY. THE MOST
PERSISTENT SNOW SHOWERS WITH THE BEST CHANCE OF ACCUMULATION WILL BE
IN THE TYPICAL SNOW BELTS OF NORTHWEST LOWER AND EAST UPPER
MICHIGAN.
&&
.UPDATE...
ISSUED AT 708 AM EDT MON APR 1 2013
CHANGES THIS HOUR: ADDITIONAL /UPWARD/ ADJUSTMENTS TO SNOWFALL AS
A BAND OF NEARLY 5 INCHES HAS OCCURRED OVER EXTREME SW OTSEGO
COUNTY AND NW CRAWFORD COUNTY. BANDING IS MAKING ITS EXPECTED
SHIFT EAST...AND IS BEGINNING TO BECOME A LITTLE MORE DIFFUSE.
EXPECT WE/VE GOT 2-3 MORE HOURS OF DECENT ACCUMS BEFORE THINGS
WIND DOWN. ADVISORY CONTINUES TO LOOK GOOD AND WILL MAKE NO
CHANGES TO THIS.
UPDATE ISSUED AT 519 AM EDT MON APR 1 2013
CHANGES THIS HOUR: BAND HESITATED LONG ENOUGH FOR ME...AND HAVE
ISSUED A WINTER WEATHER ADVISORY FOR 4 OF THE BIG 5 /EXCLUDED
KALKASKA/ THROUGH NOON. RADAR ESTIMATES HAVE REACHED 2-3" IN
SPOTS...WITH BIG FLUFFY FLAKES FALLING HERE AT THE OFFICE
INDICATING 20:1 RATIOS LOOK GOOD. WINDS AMPLE TO BLOW THIS SNOW
AROUND AS WELL. EXPECT 2-4 OVER THE NEXT FEW HOURS AS BAND STARTS
TO EDGE EAST FROM ITS CURRENT LOCATION...BEFORE LIKELY BREAKING UP
BY LATE MORNING.
NO OTHER CHANGES ATTM.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 422 AM EDT MON APR 1 2013
HIGH IMPACT WEATHER POTENTIAL: GALE FORCE WIND GUSTS POSSIBLE ALL
MARINE WATERS THROUGH TODAY. SNOW/BLOWING SNOW WILL BRING SOME
SLICK TRAVEL AND REDUCED VISIBILITIES TO THE SNOWBELTS OF EASTERN
UPPER/NORTHERN LOWER...WITH SNOW SHOWERS REACHING ALL OTHER LOCALES
AS WELL.
OVERVIEW: WISHING THE EARLY MORNING WATER VAPOR IMAGERY WAS AN APRIL
FOOLS JOKE THIS MORNING AS IMPRESSIVE TROUGH CARVES ITSELF OUT OVER
THE GREAT LAKES REGION. PICKLE LAKE /ONTARIO/ 00Z RAOB SHOWS -42C AT
H5...-25C AT H7 AND -20C AT H8...AN ARCTIC AIRMASS INDEED WITH SURFACE
TEMPS UPSTREAM OF THE GREAT LAKES IN THE LOWER TEENS AND DEWPOINTS
FALLING TO NEAR ZERO. WITH SUBSTANTIAL DOWNSTREAM BLOCKING IN PLACE
FROM GREENLAND SOUTH AND EAST...THE DEVELOPING LONGWAVE TROUGH
OVERHEAD WILL BE IN NO HURRY TO DEPART...WITH ITS IMPACTS DOMINATING
THE SHORT TERM PORTION OF THE FORECAST.
THROUGH DAYBREAK: APX WSR-88D SHOWING LAKE EFFECT SNOW GETTING IT/S
ACT TOGETHER OVER NORTHERN LOWER...WITH PRIMARY BAND FROM ACB-GOV
STRENGTHENING WITH GOOD LAKE SUPERIOR CONNECTION. EXPECT THIS TREND
TO CONTINUE THROUGH DAYBREAK WITH AN INCH OR TWO OF SNOW POSSIBLE
OVER THE BIG 5 OF NW LOWER. WILL COVER THIS BAND WITH AN SPS FOR A
QUICK 1-2 INCHES WHICH WILL LIKELY IMPACT THE MONDAY MORNING
COMMUTE.
WINDS REMAIN QUITE BRISK AS 6MB/6HR PRESSURE RISE CENTER OVER
NORTHERN LAKE SUPERIOR SLIDES SOUTH AND EAST...WITH 15-25 MPH WINDS
THROUGHOUT NORTHERN MICHIGAN...GUSTING AS HIGH AS 35 MPH NEAR THE
COASTS.
TODAY: WITH THE CORE OF THE H5 LOW PUSHING FROM JUST NORTH OF THE
SOO EARLY THIS MORNING TO SOUTHWESTERN QUEBEC BY THSI EVENING...OUR
FLOW ALOFT WILL BACK SLIGHTLY AS THE COLDEST AIR ALOFT MAKES ITS
CLOSEST APPROACH. T8 AROUND -17C WITH WHAT LOOKS TO BE ROBUST
LLEVEL MOISTURE /SEE FOG PRODUCT IMAGERY SHOWING ALL KINDS OF
MOISTURE JUST WEST OF THE H5 LOW CENTER /AND THUS...OVERHEAD
TODAY/. THIS SPELLS CONTINUED LAKE EFFECT SNOW SHOWERS UNDER STRONG
NW WINDS. ALL HIGH RESOLUTION GUIDANCE CONTINUES TO SHOW A DOMINANT
BAND TO START THE DAY...WITH THE HRRR LOOKING TO CAPTURE IT/S
LOCATION BEST /FURTHER WEST THAN THE RAP AND LOCAL WRF/. GIVEN THAT
WE ALREADY HAVE A BAND OF THIS NATURE...SEE NO REASON TO DISAGREE
WITH THE GUDIANCE SUGGESTION...WHICH SHOWS THIS BAND STARTING THE
DAY CENTERED FROM CVX-ACB-GOV PUSHING EAST GIVEN THE AFOREMENTIONED
BACKING FLOW...WITH SOMEWHAT LIGHTER SHSN SURROUNDING IT. THE BAND
LOOKS TO BE QUITE MOBILE THROUGH THE MORNING BEFORE CAPE/SHEAR
NOMOGRAM SUGGESTS THAT BY LATE MORNING IT WIL BEGIN TO BREAK UP AS
OVERLAND INSTABILITY STRENGTHENS. THIS BACKING FLOW SHOULD HELP GET
WESTERN CHIPPEWA/MACKINAC BACK INTO THE ACTION DURING THE DAY AS
WELL.
SNOWFALL: MOBILE SNOWBAND WILL KEEP A LID ON SNOW AMOUNTS...BUT
COULD SEE 1-3" FOR THE DAY TODAY OVER THE NW SNOWBELTS...WITH MOST
OF THIS FALLING BEFORE ACTIVITY BECOMES MORE CELLULAR THIS
AFTERNOON.
WHILE WE LOSE HELP FROM ANY ISALLOBARIC COMPONENT TO THE LLEVEL
WINDS TODAY...H9 WINDS 25-30KTS AND AMPLE LLEVEL MIXING SUGGEST
WINDS 15-25 MPH WINDS WITH GUSTS WELL INTO THE 30S...PARTICULARLY
NEAR THE LAKESHORES AND OVER EASTERN UPPER.
TEMPS WILL BE VERY SLOW TO CLIMB WITH T9 AROUND -10C SUGGESTING MID
20S /SOME 20F BELOW NORMAL/ WILL BE ABOUT ALL WE CAN MUSTER. WITH
THE STRONG WINDS...WIND CHILLS WILL REMAIN IN THE TEENS THROUGH THE
DAY.
HEADLINES: WILL GO AHEAD AND DROP WINTER WEATHER ADVISORY FOR
CHIPPEWA GIVEN LOCATION OF SNOWFALL ACTIVITY WELL WEST OF COUNTY
WITH ACCUMS THUS FAR NOT SUFFICIENT TO WARRANT THE HEADLINE.
AS DISCUSSED ABOVE...HEAVIEST SNOW IS NOW OVER THE BIG 5 IN NW
LOWER...AND WILL MONITOR FOR POTENTIAL HEADLINE THROUGH
DAYBREAK...ALTHOUGH EXPECTATION IS THAT THE BAND WILL BEGIN TO
MOVE...REDUCING THE THREAT OF SIGNIFICANT ACCUMS.
TONIGHT: SYNOPTIC MOISTURE BEGINS TO SLOWLY ERODE WITH TEMPS ALOFT
STEADY OR JUST SLIGHTLY WARING UNDER A FAIRLY STEADY 300-310 FLOW
REGIME. SOME RESIDUAL LAND-BASED CAPE CONTINUES THROUGH THE
OVERNIGHT WHICH MAY NOT FULLY ALLOW THE LAKE EFFECT TO RE-SOLIDIFY
INTO BANDS. SHSN WILL CERTAINLY CONTINUE...HOWEVER...WITH
ADDITIONAL LIGHT ACCUMULATIONS LIKELY. INHERITED ACCUMS OF 1-2
INCHES /PERHAPS 3 OVER WESTERN CHIPPEWA/ LOOK REASONABLE AND HAVE NO
COMPELLING REASON TO DEVIATE SIGNIFICANTLY.
CLOUDS WILL LIKELY KEEP TEMPERATURES FROM FALLING ALL THAT FAR...
GENERALLY IN THE UPPER TEENS TO AROUND 20.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 422 AM EDT MON APR 1 2013
TUESDAY...AS THE SFC HIGH BEGINS TO MOVE INTO THE REGION, THE 850 MB
TEMPERATURES BEGIN TO WARM SLIGHTLY, JUST ENOUGH THAT WE MAY LOSE
THE INSTABILITY NEEDED FOR THE LES. THE MOISTURE IN THE 850-700 MB
LAYER FALLS OFF TO BELOW 60% ON ALL THE MODELS SO WOULD EXPECT LIGHT
SNOW AND FLURRIES. ALTHOUGH WILL HAVE LIKELY POPS SINCE MEASURABLE
SNOW IS EXPECTED FROM THIS PATTERN IN THE MORNING. BY THE AFTERNOON,
THE MOISTURE CONTINUES TO FALL OFF IN THE 850-700 MB LAYER. THE ONE
THING THAT I HAVE NOTICED ABOUT THESE LATE SEASON LES EVENTS IS THAT
IT HAS BECOME HARD FOR THE LOWER END OF THE SOUNDINGS TO SATURATE.
THIS HAS BEEN LEADING TO INVERTED V SOUNDINGS AND REALIZING LESS
SNOW THAN WE WOULD HAVE EVEN A MONTH AGO DURING THE AFTERNOON.
TUESDAY NIGHT...AS THE RIDGE BUILDS INTO THE REGION, THE DRIER AIR
REALLY BEGINS TO OVERWHELM THE REGION, SHUTTING OFF MOST OF THE SNOW
LEAVING ONLY CHANCE POPS IN THE EVENING IN E UPPER, WHILE N LOWER
WILL BE DRY ENOUGH TO NOT HAVE ANY SNOW.
WEDNESDAY...HIGH PRESSURE AT THE SFC AND 500 MB RIDGE MOVES THROUGH
THE REGION SO THAT WE WILL REMAIN DRY FOR THE DAY. OVERNIGHT, A COLD
FRONT AND 500 MB SHORTWAVE TROUGH MOVE INTO THE REGION. THE GFS IS A
LITTLE FASTER THAN THE ECMWF AND NAM. WILL HOLD OFF THE SNOW BY
ALLOWING IT TO JUST TOUCH E UPPER BY 12Z.
EXTENDED (THURSDAY THROUGH SUNDAY)...THURSDAY, THE MODELS DRY THINGS
OUT WITH THE FRONTAL PASSAGE DURING THE DAY. SO WILL HAVE CHANCE
POPS WITH A MIX OF THE RAIN AND SNOW IN E UPPER AND JUST RAIN IN N
LOWER. WITH THE SFC TEMPERATURES IN THE 40S, WOULD NOT BE SURPRISED
IF THIS TURNS OUT TO BE FLURRIES AND SPRINKLES. FRIDAY, THE HIGH
BUILDS INTO THE UPPER GREAT LAKES REGION AND DRIES THINGS OUT AGAIN.
SO DRY WEATHER WILL BE EXPECTED. SATURDAY, THE WARM FRONT WILL BE
MOVING INTO THE REGION. THE ECMWF HAS THE WARM AIR INTO E UPPER SO
THAT IT COULD BE ALL RAIN, WHILE THE GFS HAS IT PLACED A LITTLE
SOUTH. PUT THE DIVIDING LINE AT THE STRAITS SINCE THAT SEEMED TO BE
THE MIDDLE GROUND. WHICH WOULD CONTINUE THROUGH THE NIGHT AS THE
SYSTEM MOVES EAST. SUNDAY, THE LOW MOVES EAST OF THE REGION AND THE
COLD AIR MOVES BACK IN ALLOWING FOR A CHANGE OVER TO SNOW. THE GFS
DRIES THINGS OUT. WILL LEAN TOWARD THE ECMWF WHICH WOULD BE THE
PESSIMISTIC FORECAST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 708 AM EDT MON APR 1 2013
SUMMARY: STRONG LOW PRESSURE...DEPARTING INTO EASTERN CANADA WILL
CAUSE STRONG NORTHWEST WINDS THROUGH THE UPCOMING TAF PERIOD...WITH
OCCASIONAL LAKE EFFECT SNOW SHOWERS IMPACTING THE TAF SITES.
RESTRICTIONS: LAKE EFFECT SNOW BANDS DOING A GOOD JOB AVOIDING THE
TERMINALS EARLY THIS MORNING. PRIMARY BAND FROM CHARLEVOIX TO
GAYLORD WILL START TO BREAK UP AS IT SHIFTS EAST...BUT WILL LIKELY
BRING A PERIOD OF MVFR/IFR TO PLN FOR A TIME THIS MORNING. LAKE
EFFECT SHSN WILL CONTINUE THIS AFTERNOON...BUT IN A MORE
CELLULAR/SCATTERED FASHION...WHICH WILL LIKELY ALLOW TVC/MBL/APN TO
REMAIN VFR WHILE PLN DEALS WITH OCCASIONAL MVFR VSBYS-CIGS /WITH
PERHAPS VERY BRIEF IFR VSBYS/. SHSN ACTIVITY WILL CONTINUE
TONIGHT...BUT WILL AVOID INCLUDING MVFR/IFR RESTRICTIONS IN THIS TAF
PACKAGE AS THESE SHSN WILL BE SHORT-LIVED AND CONFIDENCE NOT HIGH
ENOUGH ON LOCATION /ALTHOUGH BEST CHANCES WILL LIKELY CONTINUE TO BE
AT PLN/ TO INCLUDE.
WINDS: NORTHWEST WINDS WILL REACH 18G28KTS FOR THE DAY TODAY BEFORE
DIMINISHING TO 10-15KTS TONIGHT.
&&
.MARINE...
ISSUED AT 422 AM EDT MON APR 1 2013
UPDATE AT 708 AM...DROPPED GALE WARNINGS FOR ALL AREAS SAVE
WHITEFISH BAY AND THE COAST OF NORTHERN LAKE HURON. HIGH END SMALL
CRAFTS SHOULD SUFFICE THROUGH TODAY AND WILL NEED EXTENDING BEYOND
TONIGHT IN SUBSEQUENT UPDATES.
SUMMARY: STRONG NORTHWESTERLY WINDS TO CONTINUE THROUGH TUESDAY AS
LOW PRESSURE MOVES INTO EASTERN CANADA. HIGH PRESSURE ARRIVES BY
MIDWEEK WITH QUIETER CONDITIONS EXPECTED.
HEADLINES: MARGINAL GALES WILL BE ALLOWED TO CONTINUE ALL ZONES
THROUGH THIS EVENING. SMALL CRAFTS WILL CERTAINLY BE NEEDED BEYOND
THIS...WITH ADDITIONAL GALE FORCE GUSTS POSSIBLE AGAIN
TUESDAY...PARTICULARLY FOR NORTHWESTERLY FLOW FAVORED REGIONS.
BEYOND THIS...NEXT ROUND OF SMALL CRAFTS LOOKS LIKELY BY WEDNESDAY
NIGHT OVER LAKE MICHIGAN AS SOUTHWESTERLY WINDS STRENGTHEN AHEAD OF
NEXT APPROACHING SYSTEM.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL NOON EDT TODAY FOR MIZ019-021-022-
028.
LH...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LHZ345-346-
349.
GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LHZ347-348.
LM...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LMZ323-341-
342-344>346.
LS...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LSZ322.
GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LSZ321.
&&
$$
UPDATE...ARNOTT
SYNOPSIS...JL
SHORT TERM...ARNOTT
LONG TERM...JL
AVIATION...ARNOTT
MARINE...ARNOTT
AREA FORECAST DISCUSSION...UPDATED
NWS GAYLORD MI
523 AM EDT MON APR 1 2013
.SYNOPSIS...
ISSUED AT 422 AM EDT MON APR 1 2013
A SYSTEM IN QUEBEC IS BRINGING COLD AIR AND NORTHWEST WINDS TO THE
STATE TODAY. THE COLDER AIR IS PRODUCING LAKE EFFECT SNOW SHOWERS
WHICH WILL PERSIST OVER NORTHERN MICHIGAN THROUGH TUESDAY. THE MOST
PERSISTENT SNOW SHOWERS WITH THE BEST CHANCE OF ACCUMULATION WILL BE
IN THE TYPICAL SNOW BELTS OF NORTHWEST LOWER AND EAST UPPER
MICHIGAN.
&&
.UPDATE...
ISSUED AT 519 AM EDT MON APR 1 2013
CHANGES THIS HOUR: BAND HESITATED LONG ENOUGH FOR ME...AND HAVE
ISSUED A WINTER WEATHER ADVISORY FOR 4 OF THE BIG 5 /EXCLUDED
KALKASKA/ THROUGH NOON. RADAR ESTIMATES HAVE REACHED 2-3" IN
SPOTS...WITH BIG FLUFFY FLAKES FALLING HERE AT THE OFFICE
INDICATING 20:1 RATIOS LOOK GOOD. WINDS AMPLE TO BLOW THIS SNOW
AROUND AS WELL. EXPECT 2-4 OVER THE NEXT FEW HOURS AS BAND STARTS
TO EDGE EAST FROM ITS CURRENT LOCATION...BEFORE LIKELY BREAKING UP
BY LATE MORNING.
NO OTHER CHANGES ATTM.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 422 AM EDT MON APR 1 2013
HIGH IMPACT WEATHER POTENTIAL: GALE FORCE WIND GUSTS POSSIBLE ALL
MARINE WATERS THROUGH TODAY. SNOW/BLOWING SNOW WILL BRING SOME
SLICK TRAVEL AND REDUCED VISIBILITIES TO THE SNOWBELTS OF EASTERN
UPPER/NORTHERN LOWER...WITH SNOW SHOWERS REACHING ALL OTHER LOCALES
AS WELL.
OVERVIEW: WISHING THE EARLY MORNING WATER VAPOR IMAGERY WAS AN APRIL
FOOLS JOKE THIS MORNING AS IMPRESSIVE TROUGH CARVES ITSELF OUT OVER
THE GREAT LAKES REGION. PICKLE LAKE /ONTARIO/ 00Z RAOB SHOWS -42C AT
H5...-25C AT H7 AND -20C AT H8...AN ARCTIC AIRMASS INDEED WITH SURFACE
TEMPS UPSTREAM OF THE GREAT LAKES IN THE LOWER TEENS AND DEWPOINTS
FALLING TO NEAR ZERO. WITH SUBSTANTIAL DOWNSTREAM BLOCKING IN PLACE
FROM GREENLAND SOUTH AND EAST...THE DEVELOPING LONGWAVE TROUGH
OVERHEAD WILL BE IN NO HURRY TO DEPART...WITH ITS IMPACTS DOMINATING
THE SHORT TERM PORTION OF THE FORECAST.
THROUGH DAYBREAK: APX WSR-88D SHOWING LAKE EFFECT SNOW GETTING IT/S
ACT TOGETHER OVER NORTHERN LOWER...WITH PRIMARY BAND FROM ACB-GOV
STRENGTHENING WITH GOOD LAKE SUPERIOR CONNECTION. EXPECT THIS TREND
TO CONTINUE THROUGH DAYBREAK WITH AN INCH OR TWO OF SNOW POSSIBLE
OVER THE BIG 5 OF NW LOWER. WILL COVER THIS BAND WITH AN SPS FOR A
QUICK 1-2 INCHES WHICH WILL LIKELY IMPACT THE MONDAY MORNING
COMMUTE.
WINDS REMAIN QUITE BRISK AS 6MB/6HR PRESSURE RISE CENTER OVER
NORTHERN LAKE SUPERIOR SLIDES SOUTH AND EAST...WITH 15-25 MPH WINDS
THROUGHOUT NORTHERN MICHIGAN...GUSTING AS HIGH AS 35 MPH NEAR THE
COASTS.
TODAY: WITH THE CORE OF THE H5 LOW PUSHING FROM JUST NORTH OF THE
SOO EARLY THIS MORNING TO SOUTHWESTERN QUEBEC BY THSI EVENING...OUR
FLOW ALOFT WILL BACK SLIGHTLY AS THE COLDEST AIR ALOFT MAKES ITS
CLOSEST APPROACH. T8 AROUND -17C WITH WHAT LOOKS TO BE ROBUST
LLEVEL MOISTURE /SEE FOG PRODUCT IMAGERY SHOWING ALL KINDS OF
MOISTURE JUST WEST OF THE H5 LOW CENTER /AND THUS...OVERHEAD
TODAY/. THIS SPELLS CONTINUED LAKE EFFECT SNOW SHOWERS UNDER STRONG
NW WINDS. ALL HIGH RESOLUTION GUIDANCE CONTINUES TO SHOW A DOMINANT
BAND TO START THE DAY...WITH THE HRRR LOOKING TO CAPTURE IT/S
LOCATION BEST /FURTHER WEST THAN THE RAP AND LOCAL WRF/. GIVEN THAT
WE ALREADY HAVE A BAND OF THIS NATURE...SEE NO REASON TO DISAGREE
WITH THE GUDIANCE SUGGESTION...WHICH SHOWS THIS BAND STARTING THE
DAY CENTERED FROM CVX-ACB-GOV PUSHING EAST GIVEN THE AFOREMENTIONED
BACKING FLOW...WITH SOMEWHAT LIGHTER SHSN SURROUNDING IT. THE BAND
LOOKS TO BE QUITE MOBILE THROUGH THE MORNING BEFORE CAPE/SHEAR
NOMOGRAM SUGGESTS THAT BY LATE MORNING IT WIL BEGIN TO BREAK UP AS
OVERLAND INSTABILITY STRENGTHENS. THIS BACKING FLOW SHOULD HELP GET
WESTERN CHIPPEWA/MACKINAC BACK INTO THE ACTION DURING THE DAY AS
WELL.
SNOWFALL: MOBILE SNOWBAND WILL KEEP A LID ON SNOW AMOUNTS...BUT
COULD SEE 1-3" FOR THE DAY TODAY OVER THE NW SNOWBELTS...WITH MOST
OF THIS FALLING BEFORE ACTIVITY BECOMES MORE CELLULAR THIS
AFTERNOON.
WHILE WE LOSE HELP FROM ANY ISALLOBARIC COMPONENT TO THE LLEVEL
WINDS TODAY...H9 WINDS 25-30KTS AND AMPLE LLEVEL MIXING SUGGEST
WINDS 15-25 MPH WINDS WITH GUSTS WELL INTO THE 30S...PARTICULARLY
NEAR THE LAKESHORES AND OVER EASTERN UPPER.
TEMPS WILL BE VERY SLOW TO CLIMB WITH T9 AROUND -10C SUGGESTING MID
20S /SOME 20F BELOW NORMAL/ WILL BE ABOUT ALL WE CAN MUSTER. WITH
THE STRONG WINDS...WIND CHILLS WILL REMAIN IN THE TEENS THROUGH THE
DAY.
HEADLINES: WILL GO AHEAD AND DROP WINTER WEATHER ADVISORY FOR
CHIPPEWA GIVEN LOCATION OF SNOWFALL ACTIVITY WELL WEST OF COUNTY
WITH ACCUMS THUS FAR NOT SUFFICIENT TO WARRANT THE HEADLINE.
AS DISCUSSED ABOVE...HEAVIEST SNOW IS NOW OVER THE BIG 5 IN NW
LOWER...AND WILL MONITOR FOR POTENTIAL HEADLINE THROUGH
DAYBREAK...ALTHOUGH EXPECTATION IS THAT THE BAND WILL BEGIN TO
MOVE...REDUCING THE THREAT OF SIGNIFICANT ACCUMS.
TONIGHT: SYNOPTIC MOISTURE BEGINS TO SLOWLY ERODE WITH TEMPS ALOFT
STEADY OR JUST SLIGHTLY WARING UNDER A FAIRLY STEADY 300-310 FLOW
REGIME. SOME RESIDUAL LAND-BASED CAPE CONTINUES THROUGH THE
OVERNIGHT WHICH MAY NOT FULLY ALLOW THE LAKE EFFECT TO RE-SOLIDIFY
INTO BANDS. SHSN WILL CERTAINLY CONTINUE...HOWEVER...WITH
ADDITIONAL LIGHT ACCUMULATIONS LIKELY. INHERITED ACCUMS OF 1-2
INCHES /PERHAPS 3 OVER WESTERN CHIPPEWA/ LOOK REASONABLE AND HAVE NO
COMPELLING REASON TO DEVIATE SIGNIFICANTLY.
CLOUDS WILL LIKELY KEEP TEMPERATURES FROM FALLING ALL THAT FAR...
GENERALLY IN THE UPPER TEENS TO AROUND 20.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 422 AM EDT MON APR 1 2013
TUESDAY...AS THE SFC HIGH BEGINS TO MOVE INTO THE REGION, THE 850 MB
TEMPERATURES BEGIN TO WARM SLIGHTLY, JUST ENOUGH THAT WE MAY LOSE
THE INSTABILITY NEEDED FOR THE LES. THE MOISTURE IN THE 850-700 MB
LAYER FALLS OFF TO BELOW 60% ON ALL THE MODELS SO WOULD EXPECT LIGHT
SNOW AND FLURRIES. ALTHOUGH WILL HAVE LIKELY POPS SINCE MEASURABLE
SNOW IS EXPECTED FROM THIS PATTERN IN THE MORNING. BY THE AFTERNOON,
THE MOISTURE CONTINUES TO FALL OFF IN THE 850-700 MB LAYER. THE ONE
THING THAT I HAVE NOTICED ABOUT THESE LATE SEASON LES EVENTS IS THAT
IT HAS BECOME HARD FOR THE LOWER END OF THE SOUNDINGS TO SATURATE.
THIS HAS BEEN LEADING TO INVERTED V SOUNDINGS AND REALIZING LESS
SNOW THAN WE WOULD HAVE EVEN A MONTH AGO DURING THE AFTERNOON.
TUESDAY NIGHT...AS THE RIDGE BUILDS INTO THE REGION, THE DRIER AIR
REALLY BEGINS TO OVERWHELM THE REGION, SHUTTING OFF MOST OF THE SNOW
LEAVING ONLY CHANCE POPS IN THE EVENING IN E UPPER, WHILE N LOWER
WILL BE DRY ENOUGH TO NOT HAVE ANY SNOW.
WEDNESDAY...HIGH PRESSURE AT THE SFC AND 500 MB RIDGE MOVES THROUGH
THE REGION SO THAT WE WILL REMAIN DRY FOR THE DAY. OVERNIGHT, A COLD
FRONT AND 500 MB SHORTWAVE TROUGH MOVE INTO THE REGION. THE GFS IS A
LITTLE FASTER THAN THE ECMWF AND NAM. WILL HOLD OFF THE SNOW BY
ALLOWING IT TO JUST TOUCH E UPPER BY 12Z.
EXTENDED (THURSDAY THROUGH SUNDAY)...THURSDAY, THE MODELS DRY THINGS
OUT WITH THE FRONTAL PASSAGE DURING THE DAY. SO WILL HAVE CHANCE
POPS WITH A MIX OF THE RAIN AND SNOW IN E UPPER AND JUST RAIN IN N
LOWER. WITH THE SFC TEMPERATURES IN THE 40S, WOULD NOT BE SURPRISED
IF THIS TURNS OUT TO BE FLURRIES AND SPRINKLES. FRIDAY, THE HIGH
BUILDS INTO THE UPPER GREAT LAKES REGION AND DRIES THINGS OUT AGAIN.
SO DRY WEATHER WILL BE EXPECTED. SATURDAY, THE WARM FRONT WILL BE
MOVING INTO THE REGION. THE ECMWF HAS THE WARM AIR INTO E UPPER SO
THAT IT COULD BE ALL RAIN, WHILE THE GFS HAS IT PLACED A LITTLE
SOUTH. PUT THE DIVIDING LINE AT THE STRAITS SINCE THAT SEEMED TO BE
THE MIDDLE GROUND. WHICH WOULD CONTINUE THROUGH THE NIGHT AS THE
SYSTEM MOVES EAST. SUNDAY, THE LOW MOVES EAST OF THE REGION AND THE
COLD AIR MOVES BACK IN ALLOWING FOR A CHANGE OVER TO SNOW. THE GFS
DRIES THINGS OUT. WILL LEAN TOWARD THE ECMWF WHICH WOULD BE THE
PESSIMISTIC FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 128 AM EDT MON APR 1 2013
SUMMARY: STRONG NORTHWEST FLOW WILL CONTINUE THROUGH THE UPCOMING
TAF PERIOD...WITH LAKE EFFECT SNOW SHOWERS OCCASIONALLY IMPACTING
THE TERMINALS.
RESTRICTIONS: EXPECT VFR CONDITIONS TO DOMINATE MOST OF THE TAF
PERIOD...WITH HEAVIEST LES OVERNIGHT TONIGHT REMAINING BETWEEN PLN
AND TVC. BANDING LOOKS TO TARGET PLN SOMETIME LATER THIS
MORNING/EARLY AFTERNOON...ALTHOUGH IT WILL LIKELY BE BREAKING UP
INTO MORE CELLULAR ACTIVITY BY THIS TIME. SO...WILL ONLY INCLUDE
A PERIOD OF MVFR WITH THIS TAF PACKAGE...AND AWAIT LATER TRENDS TO
POTENTIALLY ADD A SHORT PERIOD OF IFR.
AT THE OTHER TERMINALS...WHILE A QUICK DROP TO MVFR IN SHSN IS
POSSIBLE...THERE IS LOW CONFIDENCE IN TIMING...SO WILL FOLLOW TRENDS
THROUGH THE REMAINDER OF THE OVERNIGHT BEFORE ADDING ANY TEMPOS AT
TVC/APN. AT THIS TIME...MBL LOOKS TO REMAIN VFR.
WINDS: NORTHWEST WINDS 14G22KTS TONIGHT WILL CONTINUE 18G28KTS FOR
THE DAY ON MONDAY BEFORE DIMINISHING TO 10-15KTS MONDAY NIGHT.
&&
.MARINE...
ISSUED AT 422 AM EDT MON APR 1 2013
SUMMARY: STRONG NORTHWESTERLY WINDS TO CONTINUE THROUGH TUESDAY AS
LOW PRESSURE MOVES INTO EASTERN CANADA. HIGH PRESSURE ARRIVES BY
MIDWEEK WITH QUIETER CONDITIONS EXPECTED.
HEADLINES: MARGINAL GALES WILL BE ALLOWED TO CONTINUE ALL ZONES
THROUGH THIS EVENING. SMALL CRAFTS WILL CERTAINLY BE NEEDED BEYOND
THIS...WITH ADDITIONAL GALE FORCE GUSTS POSSIBLE AGAIN
TUESDAY...PARTICULARLY FOR NORTHWESTERLY FLOW FAVORED REGIONS.
BEYOND THIS...NEXT ROUND OF SMALL CRAFTS LOOKS LIKELY BY WEDNESDAY
NIGHT OVER LAKE MICHIGAN AS SOUTHWESTERLY WINDS STRENGTHEN AHEAD OF
NEXT APPROACHING SYSTEM.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL NOON EDT TODAY FOR MIZ019-021-022-
028.
LH...GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LHZ345>349.
LM...GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LMZ323-341-342-
344>346.
LS...GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LSZ321-322.
&&
$$
UPDATE...ARNOTT
SYNOPSIS...JL
SHORT TERM...ARNOTT
LONG TERM...JL
AVIATION...ARNOTT
MARINE...ARNOTT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
444 AM EDT MON APR 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM EDT MON APR 1 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR TROF
CENTERED FM HUDSON BAY INTO THE GRT LKS DOWNSTREAM OF UPR RDG OVER
WRN CANADA. 00Z H5/H85 TEMPS ARE AS LO AS -42C/-20C AT THE CORE OF
THE COLDEST AIR AT YPL. CYC NNW FLOW ON THE WRN FLANK OF LO PRES
MOVING SLOWLY E INTO QUEBEC IS DRAWING THIS VERY COLD AIR SWD INTO
THE UPR LKS OVER THE RELATIVELY WARM WATERS OF LAKE SUP...WITH THE
RESULT NMRS LES BANDS AS SHOWN ON MQT RADAR. WELL DEFINED AXIS OF
COLDER CLD TOPS AS SHOWN ON IR STLT IMAGERY IS PRESENT OVER THE E
HALF OF THE LK AND ASSOCIATED WITH FAIRLY SHARP H7-3 QVECTOR CNVGC.
THIS AXIS OF DEEPER MSTR HAS CAUSED SOME ENHANCEMENT TO THE SHSN.
THE HEAVIEST BAND IS STREAMING INTO CENTRAL ALGER COUNTY/SCHOOLCRAFT
COUTY...WITH SOME RETURNS AOA 30 DBZ AT 06Z. SN UNDER THIS BAND IS
LIKELY FALLING AT THE RATE OF AT LEAST AN INCH/HR GIVEN FAVORABLE
LOCATION OF UVV MAX WITHIN DGZ AS SHOWN BY PROFILE FM LOCAL HI RES
MODEL. SINCE THE COLDER CLD TOPS ARE TENDING TO DRIFT TO THE E AND
DRIER LLVL AIR SHOWN ON THE 00Z INL RAOB IS PRESSING TO THE E...
DROPPING THE SFC DEWPT TO NEAR 7F AT IWD AT 06Z...THE INTENSITY OF
THE LES W OF MQT HAS TENDED TO DIMINISH OVER TIME PER RADAR TRENDS
EVEN THOUGH IR STLT IMAGERY INDICATES SOME LES BANDS OVER THE W HALF
OF THE LK THAT HAVE FORMED IN THE PRESENCE OF NOCTURNAL COOLING THAT
IS SO IMPORTANT TO ACHIEVE BETTER LES BAND STRUCTURE THIS TIME OF
YEAR. NW WINDS ARE STILL GUSTING AS HI AS 40 KTS AT STANNARD ROCK AS
OF 06Z...BUT PASSAGE OF PRES RISE CENTER TRAILING THE SFC LO INTO
ONTARIO E OF LK SUP HAS CAUSED A SLOW DIMINISHING TREND TO THE WINDS.
MAIN FCST CONCERNS THIS PACKAGE ARE LES TRENDS/GOIND HEADLINES.
TODAY...MODELS INDICATE UPR TROF AXIS WL DRIFT SLOWLY TO THE E. AREA
OF DEEP LYR QVECTOR CNVGC ENHANCING COMMA HEAD/COLDER CLD TOPS NOW
OVER THE E HALF OF LK SUP IS PROGGED TO DRIFT INTO ONTARIO IN THE
09Z-12Z TIME FRAME. IN CONCERT WITH THE ARRIVAL OF SOME DRYING FM
THE W...LES INTENSITY/COVERAGE SHUD DIMINISH BY SUNRISE. BUT GIVEN
PERSISTENCE OF SGNFT BAND OVER CENTRAL ALGER COUNTY INTO NRN
SCHOOLCRAFT COUNTY IN PERSISTENT NNW FLOW THRU THE EARLY MRNG
HRS...FVRBL SN/WATER RATIOS UNDER COLDEST H85 TEMPS...AND HIER RES
MODEL FCSTS THAT SHOWING FAIRLY HI QPF THRU 18Z WITH DEEPER MSTR
PERSISTING LONGEST IN THAT AREA CLOSER TO DEPARTING LO...OPTED TO
UPGRADE GOING ADVY FOR THOSE ZONES TO AN LES WARNING. OTRW...RISING
H5 HGTS/DEEP LYR QVECTOR CNVGC/SUBSIDENCE IN THE PRESENCE OF DIURNAL
HEATING THAT TENDS TO DISRUPT THE LES PROCESS IN EARLY SPRING SHOULD
CAUSE THE LES BANDS TO WEAKEN AND TRANSITION TO A MORE BLOTCHY
APPEARANCE. SLOWLY BACKING FLOW TOWARD MORE WNW BY THE LATE IN THE
DAY WL ALSO CAUSE AREA OF HEAVIER SHSN TO SHIFT. ADDITIONAL SN
AMOUNTS OVER THE W WL BE LIGHT WITH LLVL DRY AIR HAVING A MORE SGNFT
IMPACT THERE AND MODELS HINTING TOWARD A TRANSITION TO LLVL ACYC
FLOW IN THE AFTN.
TONIGHT...STEADILY RISING HGTS/DEEP LYR QVECTOR CNVGC THAT DROPS
FCST INVRN BASE TOWARD 5-6K FT OVER EVEN THE E SUG LES INTENSITY WL
BE SOMEWHAT DIMINISHED EVEN THOUGH PERSISTENT NW FLOW/H85 TEMPS IN
THE -16 TO -17C RANGE WL ALLOW FOR CONTINUED WDSPRD LES...ESPECIALLY
AFTER MID EVNG WHEN IMPACTS OF DAYTIME HEATING WOULD TEND TO
SUBSIDE. WITH INVRN BASE OVER THE W FALLING TO ARND 4K FT OVER THE
W...SHSN INTENSITY IN THIS AREA WL BE WEAKER WITH SHORTER FETCH/LESS
MODERATION OF UPSTREAM AIRMASS. BUT STILL WENT WITH LIKELY POPS
GIVEN FVRBL NW FLOW/OVERWATER INSTABILITY/NOCTURNAL COOLING THAT WL
ALLOW LES BANDS TO REDEVELOP.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 440 AM EDT MON APR 1 2013
DESPITE ADEQUATE DELTA TS PERSISTING INTO TUESDAY FOR LAKE
EFFECT...SFC-H85 FLOW WILL BECOME INCREASINGLY ANTICYCLONIC THROUGH
THE DAY. IN ADDITION...INVERSION HEIGHTS BEGIN TO FALL OFF
SIGNIFICANTLY BELOW 5KFT. THUS...EXPECT OVERALL COVERAGE AND
INTENSITY OF LAKE EFFECT TO BE ON THE WANE AS THE DAY PROGRESSES.
TEMPERATURES WILL REMAIN WELL BELOW NORMAL WITH A SIGNIFICANT AMOUNT
OF CLOUDINESS DOWNWIND OF LAKE SUPERIOR.
LAKE CLOUDS AND EVEN A FEW FLURRIES WILL PERSIST INTO THE MORNING
WEDNESDAY OVER THE EAST. AS SURFACE RIDGE AXIS MOVES OVERHEAD
THROUGH THE DAY EXPECT SKIES TO BECOME MOSTLY SUNNY AREA WIDE.
TEMPERATURES SHOULD REBOUND BACK ABOVE FREEZING AND EVEN APPROACH 40
ACROSS THE WEST WITH WARM ADVECTION INCREASING DURING THE AFTERNOON
AND MORE SUNSHINE.
MODELS COMING INTO BETTER AGREEMENT WITH THE TIMING OF THE NEXT
SHORTWAVE AND SFC TROUGH EXPECTED TO MOVE ACROSS THE AREA WED
NIGHT/THU. THE TREND HAS BEEN TOWARD QUICKER MOVEMENT WITH THE TROUGH.
SYSTEM IS FAIRLY MOISTURE STARVED...SO DESPITE PRECIP TYPE BEING A
CHALLENGE BETWEEN RAIN AND SNOW...AMOUNTS WILL BE LIGHT ENOUGH TO BE
PRETTY INSIGNIFICANT. COLD ADVECTION BEHIND THE TROUGH SHOULD PUSH
85H TEMPS BACK DOWN TO THE -10 TO -14C RANGE BY FRIDAY. PROBABLY NOT
QUITE COLD ENOUGH FOR LAKE EFFECT THIS TIME AROUND...BUT COLDER AIR
WILL KEEP DAYTIME TEMPS BELOW AVERAGE ONLY IN THE 30S.
FORECAST FOR NEXT WEEKEND STILL PRETTY CHALLENGING...BUT MODELS
SHOWING SOME SIGNS THAT THEY ARE TRYING TO CONVERGE ON A MORE
PROBABLE OUTCOME. SHORTWAVE ENERGY AND ASSOCIATED SURFACE LOW MOVING
OUT OF THE PLAINS LOOKING LIKE THEY MAY NOW TRACK THROUGH THE LOWER
LAKES WHICH WOULD STILL RESULT IN SOME LIGHT SNOWFALL ACROSS
SOUTHERN AREAS SATURDAY INTO SUNDAY BUT SPARE THE AREA FROM A MORE
SIGNIFICANT STORM. IT IS STILL SOMETHING TO KEEP AN EYE ON AS WE
HEAD THROUGH THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 129 AM EDT MON APR 1 2013
INCREASINGLY COLDER AIR MOVING ACROSS LAKE SUPERIOR IN NW FLOW WILL
SUSTAIN PERIODS OF LAKE EFFECT SNOW SHOWERS AND MVFR CONDITIONS INTO
MONDAY AT ALL 3 TAF SITES. GUSTY NW WINDS TO 25 KTS AT TIMES COULD
ALSO CONTRIBUTE TO LOWER IFR VSBYS IN SNOW AND BLOWING SNOW...MAINLY
AT MORE EXPOSED KCMX SITE. WINDS BACKING A BIT MORE TO THE
WNW...SHOULD REDUCE CHCS FOR LAKE EFFECT SNOW SHOWERS AT KSAW BY
MONDAY AFTERNOON...PERHAPS EVEN LEADING TO VFR CONDITIONS BY MONDAY
EVENING. ARRIVAL OF DRIER NEAR SFC AIR SHOWN ON THE 00Z INL RAOB WILL
ALSO BRING ABOUT LONG PERIODS OF VFR CONDITIONS AT IWD. THE
COMBINATION OF THE DRYING AND DAYTIME HEATING THIS AFTN WILL DIMINISH
THE LES INTENSITY AT CMX AS WELL.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 440 AM EDT MON APR 1 2013
AS LO PRES OVER SE CANADA CONTINUES TO THE E AND THE PRES GRADIENT
WEAKENS...EXPECT NW WINDS TO SLOWLY DIMINISH AND BELOW GALE FORCE
OVER THE CENTRAL BY MID MORNING...SO HASTENED THE ENDING OF THE GALE
WARNINGS FOR THIS AREA. ALTHOUG NW GALES TO 35 KTS WILL CONTINUE
LONGER OVER THE E INTO THIS EVENING...ENDED THE GALES FOR THAT AREA
EARLIER AS WELL. WINDS/WAVES WILL BE SUFFICIENT TO MAINTAIN FREEZING
SPRAY OVER AT LEAST THE E HALF THRU TONIGHT.
WINDS WILL REMAIN PRETTY GUSTY UP TO 30 KNOTS OVER THE EASTERN LAKE
THROUGH THE DAY ON TUESDAY...BUT AS SURFACE RIDGE AXIS PUSHES IN
FROM THE WEST PRESSURE GRADIENT WILL RELAX AND WINDS WILL DIMINISH
DURING THE EVENING. UNTIL THAT TIME...FREEZING SPRAY SHOULD CONTINUE
ACROSS THE EASTERN LAKE. AFTER A BRIEF RESPITE ON
WEDNESDAY...SOUTHWESTERLY WINDS UP TO 25 KNOTS AHEAD OF THE NEXT
TROUGH CROSSING THE LAKE WILL INCREASE WEDNESDAY NIGHT INTO EARLY
THURSDAY BEFORE SHIFTING TO THE NORTHWEST DURING THE DAY THURSDAY
INTO THURSDAY NIGHT. WINDS FOR FRIDAY INTO NEXT WEEKEND SHOULD BE
BELOW 20 KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR MIZ007.
LAKE EFFECT SNOW WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR
MIZ006-085.
LAKE SUPERIOR...
GALE WARNING UNTIL 2 AM EDT TUESDAY FOR LSZ266-267.
GALE WARNING UNTIL NOON EDT TODAY FOR LSZ265.
GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR LSZ264.
GALE WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR LSZ249.
GALE WARNING UNTIL 6 PM EDT THIS EVENING FOR LSZ244-245.
GALE WARNING UNTIL 6 AM EDT TUESDAY FOR LSZ250-251.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...MZ
AVIATION...VOSS/KC
MARINE...KC/MZ
AREA FORECAST DISCUSSION
NWS GAYLORD MI
430 AM EDT MON APR 1 2013
.SYNOPSIS...
ISSUED AT 422 AM EDT MON APR 1 2013
A SYSTEM IN QUEBEC IS BRINGING COLD AIR AND NORTHWEST WINDS TO THE
STATE TODAY. THE COLDER AIR IS PRODUCING LAKE EFFECT SNOW SHOWERS
WHICH WILL PERSIST OVER NORTHERN MICHIGAN THROUGH TUESDAY. THE MOST
PERSISTENT SNOW SHOWERS WITH THE BEST CHANCE OF ACCUMULATION WILL BE
IN THE TYPICAL SNOW BELTS OF NORTHWEST LOWER AND EAST UPPER
MICHIGAN.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 422 AM EDT MON APR 1 2013
HIGH IMPACT WEATHER POTENTIAL: GALE FORCE WIND GUSTS POSSIBLE ALL
MARINE WATERS THROUGH TODAY. SNOW/BLOWING SNOW WILL BRING SOME
SLICK TRAVEL AND REDUCED VISIBILITIES TO THE SNOWBELTS OF EASTERN
UPPER/NORTHERN LOWER...WITH SNOW SHOWERS REACHING ALL OTHER LOCALES
AS WELL.
OVERVIEW: WISHING THE EARLY MORNING WATER VAPOR IMAGERY WAS AN APRIL
FOOLS JOKE THIS MORNING AS IMPRESSIVE TROUGH CARVES ITSELF OUT OVER
THE GREAT LAKES REGION. PICKLE LAKE /ONTARIO/ 00Z RAOB SHOWS -42C AT
H5...-25C AT H7 AND -20C AT H8...AN ARCTIC AIRMASS INDEED WITH SURFACE
TEMPS UPSTREAM OF THE GREAT LAKES IN THE LOWER TEENS AND DEWPOINTS
FALLING TO NEAR ZERO. WITH SUBSTANTIAL DOWNSTREAM BLOCKING IN PLACE
FROM GREENLAND SOUTH AND EAST...THE DEVELOPING LONGWAVE TROUGH
OVERHEAD WILL BE IN NO HURRY TO DEPART...WITH ITS IMPACTS DOMINATING
THE SHORT TERM PORTION OF THE FORECAST.
THROUGH DAYBREAK: APX WSR-88D SHOWING LAKE EFFECT SNOW GETTING IT/S
ACT TOGETHER OVER NORTHERN LOWER...WITH PRIMARY BAND FROM ACB-GOV
STRENGTHENING WITH GOOD LAKE SUPERIOR CONNECTION. EXPECT THIS TREND
TO CONTINUE THROUGH DAYBREAK WITH AN INCH OR TWO OF SNOW POSSIBLE
OVER THE BIG 5 OF NW LOWER. WILL COVER THIS BAND WITH AN SPS FOR A
QUICK 1-2 INCHES WHICH WILL LIKELY IMPACT THE MONDAY MORNING
COMMUTE.
WINDS REMAIN QUITE BRISK AS 6MB/6HR PRESSURE RISE CENTER OVER
NORTHERN LAKE SUPERIOR SLIDES SOUTH AND EAST...WITH 15-25 MPH WINDS
THROUGHOUT NORTHERN MICHIGAN...GUSTING AS HIGH AS 35 MPH NEAR THE
COASTS.
TODAY: WITH THE CORE OF THE H5 LOW PUSHING FROM JUST NORTH OF THE
SOO EARLY THIS MORNING TO SOUTHWESTERN QUEBEC BY THSI EVENING...OUR
FLOW ALOFT WILL BACK SLIGHTLY AS THE COLDEST AIR ALOFT MAKES ITS
CLOSEST APPROACH. T8 AROUND -17C WITH WHAT LOOKS TO BE ROBUST
LLEVEL MOISTURE /SEE FOG PRODUCT IMAGERY SHOWING ALL KINDS OF
MOISTURE JUST WEST OF THE H5 LOW CENTER /AND THUS...OVERHEAD
TODAY/. THIS SPELLS CONTINUED LAKE EFFECT SNOW SHOWERS UNDER STRONG
NW WINDS. ALL HIGH RESOLUTION GUIDANCE CONTINUES TO SHOW A DOMINANT
BAND TO START THE DAY...WITH THE HRRR LOOKING TO CAPTURE IT/S
LOCATION BEST /FURTHER WEST THAN THE RAP AND LOCAL WRF/. GIVEN THAT
WE ALREADY HAVE A BAND OF THIS NATURE...SEE NO REASON TO DISAGREE
WITH THE GUDIANCE SUGGESTION...WHICH SHOWS THIS BAND STARTING THE
DAY CENTERED FROM CVX-ACB-GOV PUSHING EAST GIVEN THE AFOREMENTIONED
BACKING FLOW...WITH SOMEWHAT LIGHTER SHSN SURROUNDING IT. THE BAND
LOOKS TO BE QUITE MOBILE THROUGH THE MORNING BEFORE CAPE/SHEAR
NOMOGRAM SUGGESTS THAT BY LATE MORNING IT WIL BEGIN TO BREAK UP AS
OVERLAND INSTABILITY STRENGTHENS. THIS BACKING FLOW SHOULD HELP GET
WESTERN CHIPPEWA/MACKINAC BACK INTO THE ACTION DURING THE DAY AS
WELL.
SNOWFALL: MOBILE SNOWBAND WILL KEEP A LID ON SNOW AMOUNTS...BUT
COULD SEE 1-3" FOR THE DAY TODAY OVER THE NW SNOWBELTS...WITH MOST
OF THIS FALLING BEFORE ACTIVITY BECOMES MORE CELLULAR THIS
AFTERNOON.
WHILE WE LOSE HELP FROM ANY ISALLOBARIC COMPONENT TO THE LLEVEL
WINDS TODAY...H9 WINDS 25-30KTS AND AMPLE LLEVEL MIXING SUGGEST
WINDS 15-25 MPH WINDS WITH GUSTS WELL INTO THE 30S...PARTICULARLY
NEAR THE LAKESHORES AND OVER EASTERN UPPER.
TEMPS WILL BE VERY SLOW TO CLIMB WITH T9 AROUND -10C SUGGESTING MID
20S /SOME 20F BELOW NORMAL/ WILL BE ABOUT ALL WE CAN MUSTER. WITH
THE STRONG WINDS...WIND CHILLS WILL REMAIN IN THE TEENS THROUGH THE
DAY.
HEADLINES: WILL GO AHEAD AND DROP WINTER WEATHER ADVISORY FOR
CHIPPEWA GIVEN LOCATION OF SNOWFALL ACTIVITY WELL WEST OF COUNTY
WITH ACCUMS THUS FAR NOT SUFFICIENT TO WARRANT THE HEADLINE.
AS DISCUSSED ABOVE...HEAVIEST SNOW IS NOW OVER THE BIG 5 IN NW
LOWER...AND WILL MONITOR FOR POTENTIAL HEADLINE THROUGH
DAYBREAK...ALTHOUGH EXPECTATION IS THAT THE BAND WILL BEGIN TO
MOVE...REDUCING THE THREAT OF SIGNIFICANT ACCUMS.
TONIGHT: SYNOPTIC MOISTURE BEGINS TO SLOWLY ERODE WITH TEMPS ALOFT
STEADY OR JUST SLIGHTLY WARING UNDER A FAIRLY STEADY 300-310 FLOW
REGIME. SOME RESIDUAL LAND-BASED CAPE CONTINUES THROUGH THE
OVERNIGHT WHICH MAY NOT FULLY ALLOW THE LAKE EFFECT TO RE-SOLIDIFY
INTO BANDS. SHSN WILL CERTAINLY CONTINUE...HOWEVER...WITH
ADDITIONAL LIGHT ACCUMULATIONS LIKELY. INHERITED ACCUMS OF 1-2
INCHES /PERHAPS 3 OVER WESTERN CHIPPEWA/ LOOK REASONABLE AND HAVE NO
COMPELLING REASON TO DEVIATE SIGNIFICANTLY.
CLOUDS WILL LIKELY KEEP TEMPERATURES FROM FALLING ALL THAT FAR...
GENERALLY IN THE UPPER TEENS TO AROUND 20.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 422 AM EDT MON APR 1 2013
TUESDAY...AS THE SFC HIGH BEGINS TO MOVE INTO THE REGION, THE 850 MB
TEMPERATURES BEGIN TO WARM SLIGHTLY, JUST ENOUGH THAT WE MAY LOSE
THE INSTABILITY NEEDED FOR THE LES. THE MOISTURE IN THE 850-700 MB
LAYER FALLS OFF TO BELOW 60% ON ALL THE MODELS SO WOULD EXPECT LIGHT
SNOW AND FLURRIES. ALTHOUGH WILL HAVE LIKELY POPS SINCE MEASURABLE
SNOW IS EXPECTED FROM THIS PATTERN IN THE MORNING. BY THE AFTERNOON,
THE MOISTURE CONTINUES TO FALL OFF IN THE 850-700 MB LAYER. THE ONE
THING THAT I HAVE NOTICED ABOUT THESE LATE SEASON LES EVENTS IS THAT
IT HAS BECOME HARD FOR THE LOWER END OF THE SOUNDINGS TO SATURATE.
THIS HAS BEEN LEADING TO INVERTED V SOUNDINGS AND REALIZING LESS
SNOW THAN WE WOULD HAVE EVEN A MONTH AGO DURING THE AFTERNOON.
TUESDAY NIGHT...AS THE RIDGE BUILDS INTO THE REGION, THE DRIER AIR
REALLY BEGINS TO OVERWHELM THE REGION, SHUTTING OFF MOST OF THE SNOW
LEAVING ONLY CHANCE POPS IN THE EVENING IN E UPPER, WHILE N LOWER
WILL BE DRY ENOUGH TO NOT HAVE ANY SNOW.
WEDNESDAY...HIGH PRESSURE AT THE SFC AND 500 MB RIDGE MOVES THROUGH
THE REGION SO THAT WE WILL REMAIN DRY FOR THE DAY. OVERNIGHT, A COLD
FRONT AND 500 MB SHORTWAVE TROUGH MOVE INTO THE REGION. THE GFS IS A
LITTLE FASTER THAN THE ECMWF AND NAM. WILL HOLD OFF THE SNOW BY
ALLOWING IT TO JUST TOUCH E UPPER BY 12Z.
EXTENDED (THURSDAY THROUGH SUNDAY)...THURSDAY, THE MODELS DRY THINGS
OUT WITH THE FRONTAL PASSAGE DURING THE DAY. SO WILL HAVE CHANCE
POPS WITH A MIX OF THE RAIN AND SNOW IN E UPPER AND JUST RAIN IN N
LOWER. WITH THE SFC TEMPERATURES IN THE 40S, WOULD NOT BE SURPRISED
IF THIS TURNS OUT TO BE FLURRIES AND SPRINKLES. FRIDAY, THE HIGH
BUILDS INTO THE UPPER GREAT LAKES REGION AND DRIES THINGS OUT AGAIN.
SO DRY WEATHER WILL BE EXPECTED. SATURDAY, THE WARM FRONT WILL BE
MOVING INTO THE REGION. THE ECMWF HAS THE WARM AIR INTO E UPPER SO
THAT IT COULD BE ALL RAIN, WHILE THE GFS HAS IT PLACED A LITTLE
SOUTH. PUT THE DIVIDING LINE AT THE STRAITS SINCE THAT SEEMED TO BE
THE MIDDLE GROUND. WHICH WOULD CONTINUE THROUGH THE NIGHT AS THE
SYSTEM MOVES EAST. SUNDAY, THE LOW MOVES EAST OF THE REGION AND THE
COLD AIR MOVES BACK IN ALLOWING FOR A CHANGE OVER TO SNOW. THE GFS
DRIES THINGS OUT. WILL LEAN TOWARD THE ECMWF WHICH WOULD BE THE
PESSIMISTIC FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 128 AM EDT MON APR 1 2013
SUMMARY: STRONG NORTHWEST FLOW WILL CONTINUE THROUGH THE UPCOMING
TAF PERIOD...WITH LAKE EFFECT SNOW SHOWERS OCCASIONALLY IMPACTING
THE TERMINALS.
RESTRICTIONS: EXPECT VFR CONDITIONS TO DOMINATE MOST OF THE TAF
PERIOD...WITH HEAVIEST LES OVERNIGHT TONIGHT REMAINING BETWEEN PLN
AND TVC. BANDING LOOKS TO TARGET PLN SOMETIME LATER THIS
MORNING/EARLY AFTERNOON...ALTHOUGH IT WILL LIKELY BE BREAKING UP
INTO MORE CELLULAR ACTIVITY BY THIS TIME. SO...WILL ONLY INCLUDE
A PERIOD OF MVFR WITH THIS TAF PACKAGE...AND AWAIT LATER TRENDS TO
POTENTIALLY ADD A SHORT PERIOD OF IFR.
AT THE OTHER TERMINALS...WHILE A QUICK DROP TO MVFR IN SHSN IS
POSSIBLE...THERE IS LOW CONFIDENCE IN TIMING...SO WILL FOLLOW TRENDS
THROUGH THE REMAINDER OF THE OVERNIGHT BEFORE ADDING ANY TEMPOS AT
TVC/APN. AT THIS TIME...MBL LOOKS TO REMAIN VFR.
WINDS: NORTHWEST WINDS 14G22KTS TONIGHT WILL CONTINUE 18G28KTS FOR
THE DAY ON MONDAY BEFORE DIMINISHING TO 10-15KTS MONDAY NIGHT.
&&
.MARINE...
ISSUED AT 422 AM EDT MON APR 1 2013
SUMMARY: STRONG NORTHWESTERLY WINDS TO CONTINUE THROUGH TUESDAY AS
LOW PRESSURE MOVES INTO EASTERN CANADA. HIGH PRESSURE ARRIVES BY
MIDWEEK WITH QUIETER CONDITIONS EXPECTED.
HEADLINES: MARGINAL GALES WILL BE ALLOWED TO CONTINUE ALL ZONES
THROUGH THIS EVENING. SMALL CRAFTS WILL CERTAINLY BE NEEDED BEYOND
THIS...WITH ADDITIONAL GALE FORCE GUSTS POSSIBLE AGAIN
TUESDAY...PARTICULARLY FOR NORTHWESTERLY FLOW FAVORED REGIONS.
BEYOND THIS...NEXT ROUND OF SMALL CRAFTS LOOKS LIKELY BY WEDNESDAY
NIGHT OVER LAKE MICHIGAN AS SOUTHWESTERLY WINDS STRENGTHEN AHEAD OF
NEXT APPROACHING SYSTEM.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LHZ345>349.
LM...GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LMZ323-341-342-
344>346.
LS...GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LSZ321-322.
&&
$$
SYNOPSIS...JL
SHORT TERM...ARNOTT
LONG TERM...JL
AVIATION...ARNOTT
MARINE...ARNOTT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
235 AM EDT MON APR 1 2013
.UPDATE...
ISSUED AT 233 AM EDT MON APR 1 2013
OPTED TO UPGRADE ADVY FOR ALGER/NRN SCHOOLCRAFT TO A WARNING GIVEN
PERSISTENCE OF INTENSE LES BAND JUST E OF MUNISING UNDER COLDER CLD
TOPS ASSOCIATED WITH DEEPENING UPR TROF...FVRBL SN/WATER RATIOS WITH
UVV MAX WITHIN DGZ...AND REPORTS OF SGNFT BLSN/WHITEOUT CONDITIONS
ALONG M-28. ALTHOUGH THE EXPECTED DEPARTURE OF THE COLDER CLD TOPS
BY 09Z WOULD SUG THE BAND WL DIMINISH...PERSISTENCE OF BAND SINCE
MID EVNG ARND 03Z AND ESTIMATED SN ACCUMS UP TO 2 INCHES/HR SINCE
BAND DVLPD SUG WARNING AMNTS ARE LIKELY FM SHINGLETON AND MELSTRAND
TO GRAND MARAIS AND SENEY.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 451 PM EDT SUN MAR 31 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF DEEPENING INTO THE
GREAT LAKES REGION. VIGOROUS SHORTWAVE WAS PASSING OVER LAKE
SUPERIOR. PER SATELLITE IMAGERY AND CANADIAN RADAR IMAGERY...AN
ASSOCIATED IMPRESSIVE LOOKING SMALL SWATH OF MDT TO HVY SNOW HAS
PASSED JUST N OF THE FCST AREA ACROSS FAR NRN LAKE SUPERIOR/ADJACENT
ONTARIO TODAY...ALONG/JUST N OF SHORTWAVE TRACK. AN INCREASINGLY
WELL-DEFINED SFC LOW PRES IS ORGANIZING OVER EASTERN LAKE ATTM PER
VIS SATELLITE IMAGERY. TO THE S...-SHSN TODAY HAVE DEFINITELY TAKEN
ON A SPRINGTIME DIURNAL LAND BASED LOOK WITH UNORGANIZED SCT/NMRS
COVERAGE. WELL-MIXED LAYER HAS PREVENTED SOME OF THE PCPN FROM
REACHING THE GROUND. UPSTREAM 12Z KINL SOUNDING SHOWED A DEEP
MOISTURE PROFILE TO 650MB (AROUND 11KFT)... AND MODIFYING SOUNDING
FOR A SFC T/TD IN THE LWR 30S/LWR 20S YIELDED SBCAPE AROUND
100J/KG...AND THUS THE DIURNAL COMPONENT TO THE -SHSN THIS AFTN.
MAIN FCST ISSUES TONIGHT/MON ARE POTENTIAL LES ACCUMULATIONS AS WELL
AS WINDS. FIRST UP...WINDS. EXPECT STRONGEST WINDS TO OCCUR FROM NOW
THRU THE ABOUT MID EVENING AS AREA OF 4MB/3HR PRES RISES CURRENTLY
JUST NW OF LAKE SUPERIOR SETTLES SE. THE DEEPENING INCREASINGLY
WELL-DEFINED SFC LOW OVER ERN LAKE SUPERIOR IS A CONCERN AS IT WILL
SERVE TO STRENGTHEN ISALLOBARIC WINDS. SOME OF THE HIGHER RES MODEL
GUIDANCE SEEMS TO BE PICKING UP ON THIS AS A SMALL 5-6MB/3HR PRES
RISE MAX DEVELOPS OVER CNTRL/ERN LAKE SUPERIOR WITHIN THE LARGER
SCALE PRES RISES. THE IMPACT OF THE DEEPENING LOW HAS ALREADY MADE
AN IMPACT AS WINDS HAVE GUSTED TO 50MPH AT KP59. THIS SHOULD BE A
GOOD INDICATION OF WHAT IS TO COME IN THE NEXT FEW HRS TO THE E OF
MARQUETTE. WIND ADVY HAS BEEN ISSUED FOR KEWEENAW COUNTY INTO MID
EVENING TO ACCOUNT FOR STRONG WINDS OVER THE NEXT FEW HRS.
AS FOR SNOW...NNW CYCLONIC FLOW SHOULD ALLOW SOME OF THE DEEPER
MOISTURE IN NRN ONTARIO PER 12Z CWPL SOUNDING WHICH SHOWED DEEP
MOISTURE TO 425MB (20500FT) TO SLIP INTO THE UPPER LAKES. WITH 850MB
TEMPS FALLING TO -18C BY 12Z MON...A 3KFT THICK DGZ LAYER FALLS
NICELY INTO THE CONVECTIVE LAYER WHERE NAM INDICATES RATHER VIGOROUS
UPWARD MOTION TONIGHT. WITH EQUILIBRIUM LEVELS LIKELY ABOVE 10KFT...
LES SHOULD GET GOING AT A PRETTY GOOD CLIP...BUT THE LES WILL
LIKELY TAKE SOME TIME TO GET FULLY DEVELOPED AND ORGANIZED AS THE
TYPICAL DISRUPTIVE EFFECTS OF SPRING DAYTIME HEATING ON LES WILL
NEED TO BE ERODED AWAY FIRST. ALTHOUGH IT`S NOT ESPECIALLY COLD
YET...NOTE THAT THE LAKE IS HAVING MORE OF A STABILIZING INFLUENCE
WITH LESS CLOUD OVER THE WATER THAN LAND...EXCEPT RIGHT IN THE VCNTY
OF THE SFC LOW. THE OVERNIGHT PERIOD THRU MON MORNING SHOULD BE THE
PRIME PERIOD OF LES...AND THE GOING ADVY LOOKS ON TRACK FOR THE ERN
COUNTIES ALONG LAKE SUPERIOR. WILL PROBABLY SEE SOME ACCUMULATIONS
UP TO 6-7 INCHES BY MON AFTN. CONSIDERABLE BLSN WILL ALSO BE AN
ISSUE...ESPECIALLY IN OPEN AREAS NEAR LAKE SUPERIOR. THE W WILL BE
MORE ON THE FRINGE OF THE DEEPER MOISTURE PLUS FCST SOUNDINGS SHOW
MORE OF A WELL MIXED BOUNDARY LAYER LINGERING THRU THE NIGHT WHICH
ARGUES FOR LIGHTER LES THAN OVER THE E. ACCUMULATIONS TONIGHT THRU
EARLY MON AFTN SHOULD BE IN THE 1-4 INCH RANGE OVER THE W...
INCLUDING INTO THE HIGHER TERRAIN OF NW MARQUETTE COUNTY.
CONDITIONS REMAIN FAVORABLE FOR LES MON AS 850MB TEMPS ONLY RISE A
DEGREE OR TWO IN THE AFTN. MOISTURE PROFILE REMAINS DEEP OVER THE
E...BUT DOES BECOME MORE SHALLOW OVER THE W. SO LES WILL DIMINISH
OVER THE W. EVEN OVER THE E...EXPECT LES TO BEGIN TO DIMINISH IN THE
AFTN AS STRONG DAYTIME HEATING DISRUPTS LES PROCESSES.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 451 PM EDT SUN MAR 31 2013
LAKE EFFECT WILL BE ONGOING AT THE START OF THE LONGER TERM PERIOD
ON MONDAY NIGHT. INVERSIONS 6-8KFT AND DELTA T/S AROUND 18C WITH
LAKE EQL NEARING 10KFT INDICATE NW FLOW AREAS EAST OF MARQUETTE WILL
CONTINUE TO SEE LIGHT AND MAYBE MODERATE SNOW ACCUMS AND CONTINUING
BLOWING SNOW. HEAVIER SNOW LIKELY OCCURS OVERNIGHT MONDAY NIGHT
THROUGH EARLY TUESDAY MORNING WHEN DIURNAL DISRUPTION IS MINIMAL
AND WHEN LOW-LEVEL CONVERGENCE IS STRONGEST. POSSIBLE THAT MORE
ADVISORIES MAY BE NEEDED MONDAY NIGHT THROUGH TUESDAY MORNING IN
AREAS THAT ARE CURRENTLY IN A HEADLINE.
SFC-H85 FLOW BECOMES INCREASINGLY ANTICYCLONIC TUESDAY WHICH OFFSETS
SUFFICIENT OVER-WATER INSTABILITY AS H85 TEMPS STAY AOB -15C THROUGH
18Z TUESDAY. GFS SOUNDINGS SHOW INVERSION FALLING BLO 5KFT OVR WEST
AFT 12Z AND TO AROUND 5KFT FOR AREAS OVR EASTERN CWA. NO ADDITIONAL
DEEPER MOISTURE AND CYCLONIC FLOW AT A MINIMUM SHOULD COMBINE WITH
HIGHER EARLY APRIL SUN ANGLE/BLYR HEATING TO CONSIDERABLY DISRUPT
LAKE EFFECT BY TUESDAY AFTN. GFS/GEM-NH SLIGHTLY LOWER WITH HEIGHTS
AND COLDER AT H85 FARTHER WEST TUESDAY NIGHT INTO EARLY WEDNESDAY
MORNING. RESULT IS AT LEAST ISOLD LK EFFECT CONTINUING OVER FAR
EASTERN CWA. ECMWF MORE PROGRESSIVE WITH HEIGHTS AND KEEPS COLDER
AIR ON THE MOVE LEADING TO LESS OF CHANCE OF LK EFFECT INTO
WEDNESDAY. SOME HINT OF ANOTHER WEAKER TROUGH UPSTREAM THAT WILL
HAVE TO DROP ACROSS THE UPPER LAKES AS LARGER TROUGH MOVES TO EAST.
WILL HEDGE FORECAST TOWARD GFS/GEM-NH IDEA.
SHORTWAVE RIDGING SLIDES ACROSS AREA FOR WEDNESDAY. LINGERING LK
EFFECT CLOUDS/FLURRIES IN THE MORNING EAST...BUT THIS SHOULD BREAK
UP IN AFTN WITH ARRIVAL OF SFC-H925 RIDGE. MAY SEE INCREASING HIGH
CLOUDS OVER WEST BY LATE AFTN. OTHERWISE...A WARMER DAY SHAPING UP
WITH LIGHT WINDS/LAKE BREEZES. MIXING TO H9-H85 SUPPORTS MAX TEMPS
AS WARM AS LOWER 40S IN THE WEST AND STILL ABOVE THE FREEZING MARK
ELSEWHERE.
HIGH CLOUDS SPILLING IN LATE ON WEDNESDAY ARE IN ADVANCE OF
SHORTWAVE TROUGH TRACKING ACROSS NORTHERN MANITOBA AND NORTHERN
ONTARIO. MODELS STILL AT ODDS HOW QUICKLY THIS SYSTEM MOVES
THROUGH WEDNESDAY NIGHT AND THURSDAY. 00Z GFS WAS SLOWER BUT 06Z
LOOKS MORE LIKE ECMWF. GEM-NH WRAPPED UP AND SLOWER. HEIGHT FALLS
AND H7-H5 Q-VECTOR CONVERGENCE FOCUS MOST PRECIPITATION WELL TO
NORTH OF LK SUPERIOR. SFC-H85 FRONT/1000-850MB MOISTURE CONVERGENCE
SWINGING ACROSS LK SUPERIOR AND UPR MICHIGAN...ALONG WITH RIBBON OF
HIGHER H85-H7 MOISTURE...H85 MOISTURE/TEMPERATURE ADVECTION AND
STEEPER H7-H5 LAPSE RATES AOA 6.5C/KM NOSING IN FROM WEST ADD UP TO
BRIEF PERIOD OF SCATTERED PRECIPITATION AS FRONT WORKS THROUGH. IF
TIMING IS LIKE ECMWF...THEN BETTER CHANCES WILL BE IN THE NORTH. IF
TIMING ENDS UP SLOWER...THEN MORE AREAS SEE CHANCES AS HEATING
OF THE DAY COMBINES WITH THE FORCING. EVEN WITH SLOWER IDEA...MOST
PRECIP SHOULD BE OUT OF AREA BY MID AFTN. PTYPE ALSO DEPENDS ON
TIMING AS A LATER ARRIVAL WOULD BRING RAIN POTENTIAL INTO MIX.
FOR NOW...LOOKS LIKE MOSTLY SNOW AS SOUNDINGS INDICATE WET BULB
FALLS BLO ZERO EXCEPT FOR FAR LOWEST REACHES OF BLYR. ONCE FRONT
MOVES THROUGH QUIET WEATHER EXPECTED THROUGH FRIDAY AS HIGH PRESSURE
DRIFTS ACROSS. GFS A FEW DEGREES COLDER AT H85 ON FRIDAY COMPARED TO
ECMWF AND THUS HAS MORE IN WAY OF LAKE EFFECT CLOUDS.
SYSTEM FOR NEXT WEEKEND STILL SHOWING UP...BUT THERE REMAIN SOME
BIG QUESTIONS. UPPER LAKES REMAINS ON SOUTHERN EDGE OF STRONGER JET
STREAM RIDING ALONG SOUTHERN TIER OF CANADA...WHICH WILL HELP
ENHANCE PRECIPITATION ALONG SFC-H85 BAROCLINIC ZONE. WHERE THAT ZONE
IS LOCATED IS UNCERTAIN. AS MID-LEVEL FLOW BECOMES MORE WESTERLY...
SHORTWAVE TROUGH AND SFC-H85 LOWS MOVE FROM ROCKIES ACROSS THE
NORTHERN PLAINS INTO WESTERN GREAT LAKES. OPERATIONAL MODELS FROM
LAST NIGHT AND NAEFS ENSEMBLES INDICATED SLOWER ARRIVAL TO
PRECIPITATION NOT IMPACTING MUCH OF UPR MICHIGAN UNTIL SATURDAY
NIGHT. OF COURSE THE 12Z MODELS HAVE TRENDED QUICKER AGAIN. ECMWF IS
A LOT QUICKER...BRINGING QPF OVER MOST OF UPR MICHIGAN BY 12Z
SATURDAY...AND BASED ON 1000-500MB THICKNESS/H85 TEMPS IS SHOWING
BETTER SHOT AT MIXED PRECIPITATION. KIND OF SEEMS LIKE ECMWF IS
SHOWING TWO SEPARATE WAVES OF QPF AND THAT IS WHY IT APPEARS MUCH
FASTER WITH QPF ARRIVAL. POOR RUN-TO-RUN CONSISTENCY CONTINUES WITH
THE SYSTEM. UNTIL CONSISTENCY IMPROVES WILL KEEP WITH CONSENSUS OF
MODELS FOR THIS SYSTEM FOR POPS. ENOUGH OF A SIGNAL FROM MODELS OVER
LAST COUPLE DAYS TO GO WITH RAIN AND SNOW FOR PTYPE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 129 AM EDT MON APR 1 2013
INCREASINGLY COLDER AIR MOVING ACROSS LAKE SUPERIOR IN NW FLOW WILL
SUSTAIN PERIODS OF LAKE EFFECT SNOW SHOWERS AND MVFR CONDITIONS INTO
MONDAY AT ALL 3 TAF SITES. GUSTY NW WINDS TO 25 KTS AT TIMES COULD
ALSO CONTRIBUTE TO LOWER IFR VSBYS IN SNOW AND BLOWING SNOW...MAINLY
AT MORE EXPOSED KCMX SITE. WINDS BACKING A BIT MORE TO THE
WNW...SHOULD REDUCE CHCS FOR LAKE EFFECT SNOW SHOWERS AT KSAW BY
MONDAY AFTERNOON...PERHAPS EVEN LEADING TO VFR CONDITIONS BY MONDAY
EVENING. ARRIVAL OF DRIER NEAR SFC AIR SHOWN ON THE 00Z INL RAOB WILL
ALSO BRING ABOUT LONG PERIODS OF VFR CONDITIONS AT IWD. THE
COMBINATION OF THE DRYING AND DAYTIME HEATING THIS AFTN WILL DIMINISH
THE LES INTENSITY AT CMX AS WELL.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 451 PM EDT SUN MAR 31 2013
STRONG NORTH TO NORTHWEST GALES TO 45 KTS INTO EARLY THIS EVENING
AS COLD FRONT CROSSES LK SUPERIOR. STRONGEST WINDS OCCUR THROUGH
LATE EVENING IN CORRIDOR FROM CNTRL LK SUPERIOR BUOY TO STANNARD
ROCK AND ACROSS REST OF EASTERN LK SUPERIOR. GALES CONTINUE THROUGH
MONDAY AND MONDAY NIGHT OVER SAME AREAS...BUT NOT QUITE AS STRONG.
WINDS DIMINISH TO LESS THAN 25 KTS BY WEDNESDAY MORNING AS BRIEF
RIDGING MOVES ACROSS. STRONGER SOUTHWEST WINDS TO 30 KTS THEN
EXPECTED WEDNESDAY NIGHT AND THURSDAY MORNING AS LOW PRESSURE
CROSSES NORTHERN ONTARIO AND DRAGS COLD FRONT ACROSS LK SUPERIOR.
NORTHWEST WINDS TO 25 KTS DEVELOP BEHIND THE FRONT INTO NEXT
WEEKEND. THE STRONG WINDS WILL DRAW MUCH COLDER AIR INTO THE UPPER
LAKES EARLY THIS WEEK RESULTING IN FREEZING SPRAY THROUGH TUESDAY
NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR MIZ007.
LAKE EFFECT SNOW WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR
MIZ006-085.
LAKE SUPERIOR...
GALE WARNING UNTIL 6 AM EDT TUESDAY FOR LSZ250-251-266-267.
GALE WARNING UNTIL 6 PM EDT THIS EVENING FOR LSZ244-245-264-265.
GALE WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR LSZ249.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...VOSS/KC
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
138 AM EDT MON APR 1 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 451 PM EDT SUN MAR 31 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF DEEPENING INTO THE
GREAT LAKES REGION. VIGOROUS SHORTWAVE WAS PASSING OVER LAKE
SUPERIOR. PER SATELLITE IMAGERY AND CANADIAN RADAR IMAGERY...AN
ASSOCIATED IMPRESSIVE LOOKING SMALL SWATH OF MDT TO HVY SNOW HAS
PASSED JUST N OF THE FCST AREA ACROSS FAR NRN LAKE SUPERIOR/ADJACENT
ONTARIO TODAY...ALONG/JUST N OF SHORTWAVE TRACK. AN INCREASINGLY
WELL-DEFINED SFC LOW PRES IS ORGANIZING OVER EASTERN LAKE ATTM PER
VIS SATELLITE IMAGERY. TO THE S...-SHSN TODAY HAVE DEFINITELY TAKEN
ON A SPRINGTIME DIURNAL LAND BASED LOOK WITH UNORGANIZED SCT/NMRS
COVERAGE. WELL-MIXED LAYER HAS PREVENTED SOME OF THE PCPN FROM
REACHING THE GROUND. UPSTREAM 12Z KINL SOUNDING SHOWED A DEEP
MOISTURE PROFILE TO 650MB (AROUND 11KFT)... AND MODIFYING SOUNDING
FOR A SFC T/TD IN THE LWR 30S/LWR 20S YIELDED SBCAPE AROUND
100J/KG...AND THUS THE DIURNAL COMPONENT TO THE -SHSN THIS AFTN.
MAIN FCST ISSUES TONIGHT/MON ARE POTENTIAL LES ACCUMULATIONS AS WELL
AS WINDS. FIRST UP...WINDS. EXPECT STRONGEST WINDS TO OCCUR FROM NOW
THRU THE ABOUT MID EVENING AS AREA OF 4MB/3HR PRES RISES CURRENTLY
JUST NW OF LAKE SUPERIOR SETTLES SE. THE DEEPENING INCREASINGLY
WELL-DEFINED SFC LOW OVER ERN LAKE SUPERIOR IS A CONCERN AS IT WILL
SERVE TO STRENGTHEN ISALLOBARIC WINDS. SOME OF THE HIGHER RES MODEL
GUIDANCE SEEMS TO BE PICKING UP ON THIS AS A SMALL 5-6MB/3HR PRES
RISE MAX DEVELOPS OVER CNTRL/ERN LAKE SUPERIOR WITHIN THE LARGER
SCALE PRES RISES. THE IMPACT OF THE DEEPENING LOW HAS ALREADY MADE
AN IMPACT AS WINDS HAVE GUSTED TO 50MPH AT KP59. THIS SHOULD BE A
GOOD INDICATION OF WHAT IS TO COME IN THE NEXT FEW HRS TO THE E OF
MARQUETTE. WIND ADVY HAS BEEN ISSUED FOR KEWEENAW COUNTY INTO MID
EVENING TO ACCOUNT FOR STRONG WINDS OVER THE NEXT FEW HRS.
AS FOR SNOW...NNW CYCLONIC FLOW SHOULD ALLOW SOME OF THE DEEPER
MOISTURE IN NRN ONTARIO PER 12Z CWPL SOUNDING WHICH SHOWED DEEP
MOISTURE TO 425MB (20500FT) TO SLIP INTO THE UPPER LAKES. WITH 850MB
TEMPS FALLING TO -18C BY 12Z MON...A 3KFT THICK DGZ LAYER FALLS
NICELY INTO THE CONVECTIVE LAYER WHERE NAM INDICATES RATHER VIGOROUS
UPWARD MOTION TONIGHT. WITH EQUILIBRIUM LEVELS LIKELY ABOVE 10KFT...
LES SHOULD GET GOING AT A PRETTY GOOD CLIP...BUT THE LES WILL
LIKELY TAKE SOME TIME TO GET FULLY DEVELOPED AND ORGANIZED AS THE
TYPICAL DISRUPTIVE EFFECTS OF SPRING DAYTIME HEATING ON LES WILL
NEED TO BE ERODED AWAY FIRST. ALTHOUGH IT`S NOT ESPECIALLY COLD
YET...NOTE THAT THE LAKE IS HAVING MORE OF A STABILIZING INFLUENCE
WITH LESS CLOUD OVER THE WATER THAN LAND...EXCEPT RIGHT IN THE VCNTY
OF THE SFC LOW. THE OVERNIGHT PERIOD THRU MON MORNING SHOULD BE THE
PRIME PERIOD OF LES...AND THE GOING ADVY LOOKS ON TRACK FOR THE ERN
COUNTIES ALONG LAKE SUPERIOR. WILL PROBABLY SEE SOME ACCUMULATIONS
UP TO 6-7 INCHES BY MON AFTN. CONSIDERABLE BLSN WILL ALSO BE AN
ISSUE...ESPECIALLY IN OPEN AREAS NEAR LAKE SUPERIOR. THE W WILL BE
MORE ON THE FRINGE OF THE DEEPER MOISTURE PLUS FCST SOUNDINGS SHOW
MORE OF A WELL MIXED BOUNDARY LAYER LINGERING THRU THE NIGHT WHICH
ARGUES FOR LIGHTER LES THAN OVER THE E. ACCUMULATIONS TONIGHT THRU
EARLY MON AFTN SHOULD BE IN THE 1-4 INCH RANGE OVER THE W...
INCLUDING INTO THE HIGHER TERRAIN OF NW MARQUETTE COUNTY.
CONDITIONS REMAIN FAVORABLE FOR LES MON AS 850MB TEMPS ONLY RISE A
DEGREE OR TWO IN THE AFTN. MOISTURE PROFILE REMAINS DEEP OVER THE
E...BUT DOES BECOME MORE SHALLOW OVER THE W. SO LES WILL DIMINISH
OVER THE W. EVEN OVER THE E...EXPECT LES TO BEGIN TO DIMINISH IN THE
AFTN AS STRONG DAYTIME HEATING DISRUPTS LES PROCESSES.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 451 PM EDT SUN MAR 31 2013
LAKE EFFECT WILL BE ONGOING AT THE START OF THE LONGER TERM PERIOD
ON MONDAY NIGHT. INVERSIONS 6-8KFT AND DELTA T/S AROUND 18C WITH
LAKE EQL NEARING 10KFT INDICATE NW FLOW AREAS EAST OF MARQUETTE WILL
CONTINUE TO SEE LIGHT AND MAYBE MODERATE SNOW ACCUMS AND CONTINUING
BLOWING SNOW. HEAVIER SNOW LIKELY OCCURS OVERNIGHT MONDAY NIGHT
THROUGH EARLY TUESDAY MORNING WHEN DIURNAL DISRUPTION IS MINIMAL
AND WHEN LOW-LEVEL CONVERGENCE IS STRONGEST. POSSIBLE THAT MORE
ADVISORIES MAY BE NEEDED MONDAY NIGHT THROUGH TUESDAY MORNING IN
AREAS THAT ARE CURRENTLY IN A HEADLINE.
SFC-H85 FLOW BECOMES INCREASINGLY ANTICYCLONIC TUESDAY WHICH OFFSETS
SUFFICIENT OVER-WATER INSTABILITY AS H85 TEMPS STAY AOB -15C THROUGH
18Z TUESDAY. GFS SOUNDINGS SHOW INVERSION FALLING BLO 5KFT OVR WEST
AFT 12Z AND TO AROUND 5KFT FOR AREAS OVR EASTERN CWA. NO ADDITIONAL
DEEPER MOISTURE AND CYCLONIC FLOW AT A MINIMUM SHOULD COMBINE WITH
HIGHER EARLY APRIL SUN ANGLE/BLYR HEATING TO CONSIDERABLY DISRUPT
LAKE EFFECT BY TUESDAY AFTN. GFS/GEM-NH SLIGHTLY LOWER WITH HEIGHTS
AND COLDER AT H85 FARTHER WEST TUESDAY NIGHT INTO EARLY WEDNESDAY
MORNING. RESULT IS AT LEAST ISOLD LK EFFECT CONTINUING OVER FAR
EASTERN CWA. ECMWF MORE PROGRESSIVE WITH HEIGHTS AND KEEPS COLDER
AIR ON THE MOVE LEADING TO LESS OF CHANCE OF LK EFFECT INTO
WEDNESDAY. SOME HINT OF ANOTHER WEAKER TROUGH UPSTREAM THAT WILL
HAVE TO DROP ACROSS THE UPPER LAKES AS LARGER TROUGH MOVES TO EAST.
WILL HEDGE FORECAST TOWARD GFS/GEM-NH IDEA.
SHORTWAVE RIDGING SLIDES ACROSS AREA FOR WEDNESDAY. LINGERING LK
EFFECT CLOUDS/FLURRIES IN THE MORNING EAST...BUT THIS SHOULD BREAK
UP IN AFTN WITH ARRIVAL OF SFC-H925 RIDGE. MAY SEE INCREASING HIGH
CLOUDS OVER WEST BY LATE AFTN. OTHERWISE...A WARMER DAY SHAPING UP
WITH LIGHT WINDS/LAKE BREEZES. MIXING TO H9-H85 SUPPORTS MAX TEMPS
AS WARM AS LOWER 40S IN THE WEST AND STILL ABOVE THE FREEZING MARK
ELSEWHERE.
HIGH CLOUDS SPILLING IN LATE ON WEDNESDAY ARE IN ADVANCE OF
SHORTWAVE TROUGH TRACKING ACROSS NORTHERN MANITOBA AND NORTHERN
ONTARIO. MODELS STILL AT ODDS HOW QUICKLY THIS SYSTEM MOVES
THROUGH WEDNESDAY NIGHT AND THURSDAY. 00Z GFS WAS SLOWER BUT 06Z
LOOKS MORE LIKE ECMWF. GEM-NH WRAPPED UP AND SLOWER. HEIGHT FALLS
AND H7-H5 Q-VECTOR CONVERGENCE FOCUS MOST PRECIPITATION WELL TO
NORTH OF LK SUPERIOR. SFC-H85 FRONT/1000-850MB MOISTURE CONVERGENCE
SWINGING ACROSS LK SUPERIOR AND UPR MICHIGAN...ALONG WITH RIBBON OF
HIGHER H85-H7 MOISTURE...H85 MOISTURE/TEMPERATURE ADVECTION AND
STEEPER H7-H5 LAPSE RATES AOA 6.5C/KM NOSING IN FROM WEST ADD UP TO
BRIEF PERIOD OF SCATTERED PRECIPITATION AS FRONT WORKS THROUGH. IF
TIMING IS LIKE ECMWF...THEN BETTER CHANCES WILL BE IN THE NORTH. IF
TIMING ENDS UP SLOWER...THEN MORE AREAS SEE CHANCES AS HEATING
OF THE DAY COMBINES WITH THE FORCING. EVEN WITH SLOWER IDEA...MOST
PRECIP SHOULD BE OUT OF AREA BY MID AFTN. PTYPE ALSO DEPENDS ON
TIMING AS A LATER ARRIVAL WOULD BRING RAIN POTENTIAL INTO MIX.
FOR NOW...LOOKS LIKE MOSTLY SNOW AS SOUNDINGS INDICATE WET BULB
FALLS BLO ZERO EXCEPT FOR FAR LOWEST REACHES OF BLYR. ONCE FRONT
MOVES THROUGH QUIET WEATHER EXPECTED THROUGH FRIDAY AS HIGH PRESSURE
DRIFTS ACROSS. GFS A FEW DEGREES COLDER AT H85 ON FRIDAY COMPARED TO
ECMWF AND THUS HAS MORE IN WAY OF LAKE EFFECT CLOUDS.
SYSTEM FOR NEXT WEEKEND STILL SHOWING UP...BUT THERE REMAIN SOME
BIG QUESTIONS. UPPER LAKES REMAINS ON SOUTHERN EDGE OF STRONGER JET
STREAM RIDING ALONG SOUTHERN TIER OF CANADA...WHICH WILL HELP
ENHANCE PRECIPITATION ALONG SFC-H85 BAROCLINIC ZONE. WHERE THAT ZONE
IS LOCATED IS UNCERTAIN. AS MID-LEVEL FLOW BECOMES MORE WESTERLY...
SHORTWAVE TROUGH AND SFC-H85 LOWS MOVE FROM ROCKIES ACROSS THE
NORTHERN PLAINS INTO WESTERN GREAT LAKES. OPERATIONAL MODELS FROM
LAST NIGHT AND NAEFS ENSEMBLES INDICATED SLOWER ARRIVAL TO
PRECIPITATION NOT IMPACTING MUCH OF UPR MICHIGAN UNTIL SATURDAY
NIGHT. OF COURSE THE 12Z MODELS HAVE TRENDED QUICKER AGAIN. ECMWF IS
A LOT QUICKER...BRINGING QPF OVER MOST OF UPR MICHIGAN BY 12Z
SATURDAY...AND BASED ON 1000-500MB THICKNESS/H85 TEMPS IS SHOWING
BETTER SHOT AT MIXED PRECIPITATION. KIND OF SEEMS LIKE ECMWF IS
SHOWING TWO SEPARATE WAVES OF QPF AND THAT IS WHY IT APPEARS MUCH
FASTER WITH QPF ARRIVAL. POOR RUN-TO-RUN CONSISTENCY CONTINUES WITH
THE SYSTEM. UNTIL CONSISTENCY IMPROVES WILL KEEP WITH CONSENSUS OF
MODELS FOR THIS SYSTEM FOR POPS. ENOUGH OF A SIGNAL FROM MODELS OVER
LAST COUPLE DAYS TO GO WITH RAIN AND SNOW FOR PTYPE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 129 AM EDT MON APR 1 2013
INCREASINGLY COLDER AIR MOVING ACROSS LAKE SUPERIOR IN NW FLOW WILL
SUSTAIN PERIODS OF LAKE EFFECT SNOW SHOWERS AND MVFR CONDITIONS INTO
MONDAY AT ALL 3 TAF SITES. GUSTY NW WINDS TO 25 KTS AT TIMES COULD
ALSO CONTRIBUTE TO LOWER IFR VSBYS IN SNOW AND BLOWING SNOW...MAINLY
AT MORE EXPOSED KCMX SITE. WINDS BACKING A BIT MORE TO THE
WNW...SHOULD REDUCE CHCS FOR LAKE EFFECT SNOW SHOWERS AT KSAW BY
MONDAY AFTERNOON...PERHAPS EVEN LEADING TO VFR CONDITIONS BY MONDAY
EVENING. ARRIVAL OF DRIER NEAR SFC AIR SHOWN ON THE 00Z INL RAOB WILL
ALSO BRING ABOUT LONG PERIODS OF VFR CONDITIONS AT IWD. THE
COMBINATION OF THE DRYING AND DAYTIME HEATING THIS AFTN WILL DIMINISH
THE LES INTENSITY AT CMX AS WELL.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 451 PM EDT SUN MAR 31 2013
STRONG NORTH TO NORTHWEST GALES TO 45 KTS INTO EARLY THIS EVENING
AS COLD FRONT CROSSES LK SUPERIOR. STRONGEST WINDS OCCUR THROUGH
LATE EVENING IN CORRIDOR FROM CNTRL LK SUPERIOR BUOY TO STANNARD
ROCK AND ACROSS REST OF EASTERN LK SUPERIOR. GALES CONTINUE THROUGH
MONDAY AND MONDAY NIGHT OVER SAME AREAS...BUT NOT QUITE AS STRONG.
WINDS DIMINISH TO LESS THAN 25 KTS BY WEDNESDAY MORNING AS BRIEF
RIDGING MOVES ACROSS. STRONGER SOUTHWEST WINDS TO 30 KTS THEN
EXPECTED WEDNESDAY NIGHT AND THURSDAY MORNING AS LOW PRESSURE
CROSSES NORTHERN ONTARIO AND DRAGS COLD FRONT ACROSS LK SUPERIOR.
NORTHWEST WINDS TO 25 KTS DEVELOP BEHIND THE FRONT INTO NEXT
WEEKEND. THE STRONG WINDS WILL DRAW MUCH COLDER AIR INTO THE UPPER
LAKES EARLY THIS WEEK RESULTING IN FREEZING SPRAY THROUGH TUESDAY
NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR MIZ006-
007-085.
LAKE SUPERIOR...
GALE WARNING UNTIL 6 AM EDT TUESDAY FOR LSZ250-251-266-267.
GALE WARNING UNTIL 6 PM EDT THIS EVENING FOR LSZ244-245-264-265.
GALE WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR LSZ249.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...VOSS/KC
MARINE...JLA
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1030 AM EDT MON APR 1 2013
.SYNOPSIS...
A WEAK FRONT WILL MOVE THROUGH AND BRING SCATTERED RAIN SHOWERS
THROUGH THIS AFTERNOON. A STRONGER FRONT WILL MOVE THROUGH TONIGHT
USHERING IN COOL AIR FOR THE MID WEEK PERIOD. GULF OF MEXICO LOW
PRESSURE WILL MOVE UP THE CAROLINA COAST FRIDAY BRINGING A SOAKING
RAIN. NEXT WEEKEND SHOULD BE FAIR AND SEASONABLE.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM MONDAY...SEVERAL FEATURES WORKING TOGETHER TO BRING US
SOME SHOWERS THIS MORNING...AND THESE WILL LINGER INTO THE EARLY
AFTN BEFORE RAPID DRYING OCCURS LATER TODAY.
PRECIP ONGOING AT THIS HOUR IS DRIVEN PRIMARILY BY A VORT MAX MOVING
ACROSS SC. THIS WILL CONTINUE TO WORK EAST THROUGH THE
AFTN...CONTINUING THE CHANCES FOR SHOWERS. BUFR PROFILES SUGGEST
INCREASING INSTABILITY AHEAD OF THE UPPER FEATURE...ESPECIALLY
ACROSS SOUTHERN ZONES WHICH WILL BE MORE DIRECTLY IMPACTED BY THE
IMPULSE MOVING OVERHEAD. HAVE INTRODUCED ISO -TRW FOR THE EXTREME
SOUTHERN ZONES SINCE THERE APPEARS TO BE ENOUGH LIFT AND INSTABILITY
FOR AN ISOLATED LIGHTNING STRIKE THROUGH THE AFTN...BUT NOTHING
WIDESPREAD...AND ANY CHC FOR THUNDER WILL END QUICKLY AS VORT SKIRTS
OFFSHORE.
WEAK COLD FRONT...AND I DON`T LIKE THE TERM COLD FRONT DUE TO LACK
OF ANY TEMP GRADIENT...WILL DROP SOUTH THIS AFTN BEHIND THE
DEPARTING SHORTWAVE. THE COMBINATION OF SOME SUBSIDENCE BEHIND THIS
SHORTWAVE AND DRYING BEHIND THE COLD FRONT (TROUGH) WILL BRING AN
END TO THE SHOWERS EARLY THIS AFTN...WITH RAPID DRYING OCCURRING IN
THE COLUMN THEREAFTER. THIS DRYING WILL ALLOW FOR SOME SUN TO PEEK
THROUGH THIS AFTN/EVE...AND HIGH TEMPS WILL STILL REACH TO 70 OR
HIGHER EVEN BEHIND THE "COLD FRONT" THANKS TO THE APRIL INSOLATION.
A MORE SIGNIFICANT COLD FRONT...THIS ONE ACCOMPANIED BY REAL
CAA...WILL DROP SOUTH TONIGHT AND TEMPS WILL PLUMMET BEHIND IT. THE
EXACT TIMING IS STILL IN QUESTION...BUT IT APPEARS THIS FRONT WILL
DROP THROUGH THE CWA AFTER MIDNIGHT AND HELP MINS FALL TO SEASONABLE
LEVELS...LOW 40S NORTH TO UPPER 40S SOUTH...AND HAVE LEANED ON THE
SLIGHTLY COOLER MAV NUMBERS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...DEEP UPPER CUTOFF NORTH OF NEW ENGLAND STATES ON
TUESDAY HELPING TO PUSH ARCTIC COLD FRONT AND ITS ASSOC MOISTURE OFF
TO THE SOUTH OF THE AREA. THE UPPER LOW WILL BE LIFTING OUT TO THE
NORTH A BIT HOWEVER AND THIS WILL TEMPER THE STRENGTH OF THE COLD
AIR ADVECTION INTO THE CAROLINAS. GUIDANCE HAS COME UP A FEW DEGREES
PAST SEVERAL RUNS BUT HAVE OPTED TO REMAIN A FEW DEGREES BELOW AS
THE VERY SHALLOW NATURE OF THE COLD AIR MAY BUST THE NUMBERS A BIT.
CURRENT FORECAST CAPS HIGHS AT ABOUT 10F BELOW CLIMO. THE SAME
DEVIATION FROM NORMAL IS EXPECTED TUESDAY NIGHT WITH LOWS UPPER
30S/NR 40. ATTENTION TURNS TO SOUTHERN BRANCH AS WE HEAD INTO
WEDNESDAY. THE NORTHERN STREAM UPPER LOW CONTINUES ITS SLOW
LIFTING/PROGRESSING ENERGY MOVING ACROSS TX WILL BEGIN CYCLOGENESIS
IN THE WESTERN GULF. WRF READILY SPREADS CLOUD COVER AND INCREASING
RAIN CHANCES INTO THE REGION LATE WEDNESDAY AND THEN VERY MUCH SO
WEDNESDAY NIGHT. GIVEN THE MID LEVEL CONFLUENCE ALLOWING THE HIGH TO
REALLY HANG ON AND THAT DEWPOINTS WILL INITIALIZE PRETTY LOW FEEL
THAT THIS IS TOO FAST. END OF PERIOD A COMPROMISE BETWEEN GFS AND
WRF.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 AM MONDAY...VERY RAINY PERIOD TO START THE LONG TERM AS
SOUTHERN BRANCH FEATURE TAPS COPIOUS GOMEX MOISTURE AND FLINGS IT UP
ACROSS THE CAROLINAS. THERE ARE SOME TIMING DIFFERENCES BETWEEN
VARIOUS GUIDANCE BUT THE BULK OF THE RAINFALL APPEARS TO BE SLATED
FOR THURSDAY NIGHT INTO FRIDAY MORNING. THEREAFTER DEPENDING ON THE
TRACK OF THE LOW A DRY SLOT MAY WORK UP THE COAST. TEMPS ALSO VERY
MUCH HINGE ON THE TRACK OF THE STORM AS EASTERN COUNTIES APPEAR
LIKELY TO SECURELY WARM SECTOR WHERE INLAND ZONES MAY STRUGGLE A
BIT. TOUGH TO SAY HOW QUICK THE DRYING IS LATER FRIDAY DUE TO THE
LAGGING OF THE UPPER TROUGH INCLUDING WRAPAROUND RAIN POTENTIAL
THOUGH SMALL. HIGH BUILDS IN BEHIND THIS SYSTEM FOR THE WEEKEND
AMIDST LOW AMPLITUDE MID LVL FLOW BRINGING A FAIR AMOUNT OF SUN AND
CLIMO TEMPS...EVEN PERHAPS A WARMING TREND.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
AS OF 12Z...MOST OF THE RAIN IS OVER THE WESTERN TERMINALS AT THIS
TIME. TIME HEIGHTS AND HRRR MODEL ARE IN REASONABLE AGREEMENT IN
MOVING THE PRECIP TOWARD THE COAST WITH A FRONT THAT BASICALLY
WASHES OUT AFTER IT EXITS THE COAST THIS AFTERNOON. LOOK FOR
CONDITIONS TO BOUNCE FROM VFR TO MVFR IN THE PRECIP. ALL AREAS WILL
BECOME VFR BY EARLY AFTERNOON AS THE BULK OF THE DEEP MOISTURE
SHIFTS TO THE SOUTHEAST. A STRONGER FRONT MOVES IN TONIGHT. NO
WEATHER ASSOCIATED WITH IT OTHER THAN A WIND SHIFT TO THE NORTH AND
A VFR STRATA CU CEILING.
EXTENDED OUTLOOK...VFR TUESDAY AND WEDNESDAY. SHOWERS AND SUB-VFR
CONDITIONS LIKELY THURSDAY AND FRIDAY AS LOW PRESSURE MOVES UP THE
ATLANTIC COAST.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM MONDAY...BUOY 41008 AND 41013 HAVE FINALLY SHOWN THE
RAPID DROP OFF WE WERE EXPECTING THIS MORNING...AND DROPPED THE SCA
FOR THE NC WATERS AS NEEDED. A SERIES OF COLD FRONTS...THE FIRST
QUITE WEAK...WILL DROP SOUTH ACROSS THE WATERS TODAY. THIS FIRST ONE
CROSSES LATE THIS AFTN...BRINGING A SLIGHT WIND SHIFT TO W/NW AND AN
END TO SHOWERS/TSTMS. THE STRONGER FRONT CROSSES LATE TONIGHT...AND
WILL BE ACCOMPANIED BY A STRONG BUT SHORT-LIVED SURGE OF N/NE WINDS
APPROACHING 20 KTS. WHILE SEAS MAY TICK UPWARD WITH THIS
SURGE...AFTER BEING 2-4 FT MUCH OF THE DAY...DO NOT ANTICIPATE THE
NEED FOR ANY CAUTIONARY STATEMENTS OR HEADLINES ATTM.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...MAIN AREA OF HIGH PRESSURE BUILDING IN FROM THE
NORTH AND WEST IN A FAIRLY RESTRAINED MANNER ON TUESDAY KEEPING THE
CENTER UP IN THE GREAT LAKES. A SMALLER AND POORLY DEFINED CENTER
SLIPS INTO THE CAROLINAS HOWEVER KEEPING GRADIENT VERY LIGHT LEADING
AND TAME WINDS OUT OF THE N/NE. SEAS BEGIN THE PERIOD STIRRED UP
FROM THE NEAR TERM BUT WILL QUICKLY ABATE. THE PARENT AIRMASS DRAWS
A LITTLE CLOSER WEDNESDAY PICKING UP AND SLIGHTLY VEERING THE WINDS.
AS THE HIGH SETTLES ACRS VA BY THE END OF THE PERIOD AND LOW
PRESSURE MARCHES EAST ACROSS THE GULF COAST THERE SHOULD BE AN
ADDITIONAL VEER AND SMALL INCREASE IN WINDS. THE SPEED AT WHICH THIS
HAPPENS IS A LITTLE UNCERTAIN.
.LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM MONDAY...MODERATELY STRONG SOUTHERN BRANCH FEATURE COMING
ACROSS THE GULF OF MEXICO ON THURSDAY WHILE WEST ATLANTIC HIGH
PRESSURE PROGRESSES EASTWARD BUT AT A SLOWER SPEED. THIS WILL
INCREASE THE GRADIENT UP AND DOWN THE SOUTHEAST COAST AND A SMALL
CRAFT ADVISORY WILL BE NEEDED. AS THE STORM SYSTEM TURNS TO THE NE
AND MOVES RIGHT UP THE CAROLINA COAST ON AN INLAND TRACK THE STRONG
SW FLOW WILL BE MAINTAINED IF NOT STRENGTHENED. EXPECT A FURTHER
BUILDING OF SEAS FROM ADDED FETCH DURATION IF NOTHING ELSE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TRA/JDW
NEAR TERM...JDW
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...TRA/BJR
MARINE...
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
651 AM EDT MON APR 1 2013
.SYNOPSIS...
A WEAK FRONT WILL MOVE THROUGH AND BRING WIDESPREAD RAIN THIS
MORNING. A STRONGER FRONT WILL MOVE THROUGH TONIGHT USHERING IN COOL
AIR FOR THE MID WEEK PERIOD. GULF OF MEXICO LOW PRESSURE WILL MOVE
UP THE CAROLINA COAST FRIDAY BRINGING A SOAKING RAIN. NEXT WEEKEND
SHOULD BE FAIR AND SEASONABLE.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM MONDAY...LINEAR EXTRAPOLATION OF THE BACK EDGE OF THE
RADAR ECHOES ACROSS EASTERN GEORGIA PLACES IT NEAR FLORENCE AROUND
15Z/10:00 AM EDT...AND IN WILMINGTON AROUND 1730Z/1:30 PM EDT.
THAT IS LIKELY A LITTLE SLOW GIVEN HOW QUICKLY THE UPPER LEVEL
FEATURE AND ITS SUBSEQUENT MID-LEVEL DRYING SHOULD ADVECT EAST
TOWARD THE COAST...SO I FEEL COMFORTABLE WITH A FORECAST STILL
CALLING FOR THE BULK OF THE PRECIP TO BE OFFSHORE BY NOON. 06Z
MODELS MADE NO SIGNIFICANT CHANGES WITH AFTERNOON TEMPERATURES
EITHER. PREVIOUS DISCUSSION FROM 300 AM FOLLOWS...
A COLD FRONT LIES ACROSS NORTH CAROLINA FROM NEAR CHARLOTTE
NORTHEAST THROUGH FAYETTEVILLE AND GREENVILLE... SEPARATING
SUBTROPICAL AIR TO THE SOUTH FROM A HEAVILY MODIFIED ARCTIC AIRMASS
TO THE NORTH. THIS BOUNDARY WILL SAG SOUTH DURING THE DAY...CLEARING
THE COASTLINE BY MID TO LATE AFTERNOON. IN THE UPPER LEVELS A 500 MB
DISTURBANCE WILL SWEEP OFFSHORE DURING THE LATE MORNING
HOURS...TAKING MOST OF THE DEEP-LAYER MOISTURE WITH IT.
RADAR COMPOSITES SHOW A CONCENTRATED STREAK OF SHOWERS AND EMBEDDED
THUNDERSTORMS EXTENDING FROM CAPE FEAR WESTWARD ACROSS SC TO NEAR
ATLANTA. MODEL SOUNDINGS SHOW SOMETHING WE HAVEN`T SEEN A LOT OF
THIS YEAR: CONVECTIVE INSTABILITY THROUGH A DEEP LAYER OF THE
ATMOSPHERE. CAPE VALUES ARE NOT AND WILL NOT GET VERY HIGH...ONLY A
COUPLE HUNDRED J/KG FOR ANY INITIAL PARCEL LEVEL...BUT GIVEN THE
SYNOPTIC LIFT OCCURRING IN ADVANCE OF THE SHORTWAVE UPRIGHT
CONVECTION HAS DEVELOPED AND MAY CONTINUE THROUGH THE MORNING.
RAINFALL AMOUNTS COULD APPROACH HALF AN INCH ACROSS FLORENCE...
MARION AND WHITEVILLE THIS MORNING.
ONCE THE SHORTWAVE CLEARS THE COAST THERE IS VERY LITTLE SUPPORT
REMAINING FOR SHOWER ACTIVITY. CLOUDS SHOULD ALSO DIMINISH...
ALTHOUGH MODELS CONTINUE TO PAINT BOTH CIRRUS AND SOME BOUNDARY-
LAYER DRIVEN CUMULUS INTO LATE AFTERNOON. SINCE THERE IS LITTLE REAL
COLD ADVECTION BEHIND THIS FIRST COLD FRONT HIGHS SHOULD RISE INTO
THE LOWER TO MID 70S AWAY FROM THE BEACHES...ACTUALLY A FEW DEGREES
ABOVE NORMAL. TONIGHT A SECOND MUCH STRONGER COLD FRONT WILL DIVE IN
FROM THE NORTH SHORTLY AFTER MIDNIGHT...ACCOMPANIED BY A SHIFT TO
NORTH WINDS AND A MORE IMPRESSIVE SHOT OF COLD ADVECTION.
TEMPERATURES WILL FALL IN EARNEST LATE AND LOWS SHOULD REACH THE 40S
EVERYWHERE BY DAYBREAK TUESDAY.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...DEEP UPPER CUTOFF NORTH OF NEW ENGLAND STATES ON
TUESDAY HELPING TO PUSH ARCTIC COLD FRONT AND ITS ASSOC MOISTURE OFF
TO THE SOUTH OF THE AREA. THE UPPER LOW WILL BE LIFTING OUT TO THE
NORTH A BIT HOWEVER AND THIS WILL TEMPER THE STRENGTH OF THE COLD
AIR ADVECTION INTO THE CAROLINAS. GUIDANCE HAS COME UP A FEW DEGREES
PAST SEVERAL RUNS BUT HAVE OPTED TO REMAIN A FEW DEGREES BELOW AS
THE VERY SHALLOW NATURE OF THE COLD AIR MAY BUST THE NUMBERS A BIT.
CURRENT FORECAST CAPS HIGHS AT ABOUT 10F BELOW CLIMO. THE SAME
DEVIATION FROM NORMAL IS EXPECTED TUESDAY NIGHT WITH LOWS UPPER
30S/NR 40. ATTENTION TURNS TO SOUTHERN BRANCH AS WE HEAD INTO
WEDNESDAY. THE NORTHERN STREAM UPPER LOW CONTINUES ITS SLOW
LIFTING/PROGRESSING ENERGY MOVING ACROSS TX WILL BEGIN CYCLOGENESIS
IN THE WESTERN GULF. WRF READILY SPREADS CLOUD COVER AND INCREASING
RAIN CHANCES INTO THE REGION LATE WEDNESDAY AND THEN VERY MUCH SO
WEDNESDAY NIGHT. GIVEN THE MID LEVEL CONFLUENCE ALLOWING THE HIGH TO
REALLY HANG ON AND THAT DEWPOINTS WILL INITIALIZE PRETTY LOW FEEL
THAT THIS IS TOO FAST. END OF PERIOD A COMPROMISE BETWEEN GFS AND
WRF.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 AM MONDAY...VERY RAINY PERIOD TO START THE LONG TERM AS
SOUTHERN BRANCH FEATURE TAPS COPIOUS GOMEX MOISTURE AND FLINGS IT UP
ACROSS THE CAROLINAS. THERE ARE SOME TIMING DIFFERENCES BETWEEN
VARIOUS GUIDANCE BUT THE BULK OF THE RAINFALL APPEARS TO BE SLATED
FOR THURSDAY NIGHT INTO FRIDAY MORNING. THEREAFTER DEPENDING ON THE
TRACK OF THE LOW A DRY SLOT MAY WORK UP THE COAST. TEMPS ALSO VERY
MUCH HINGE ON THE TRACK OF THE STORM AS EASTERN COUNTIES APPEAR
LIKELY TO SECURELY WARM SECTOR WHERE INLAND ZONES MAY STRUGGLE A
BIT. TOUGH TO SAY HOW QUICK THE DRYING IS LATER FRIDAY DUE TO THE
LAGGING OF THE UPPER TROUGH INCLUDING WRAPAROUND RAIN POTENTIAL
THOUGH SMALL. HIGH BUILDS IN BEHIND THIS SYSTEM FOR THE WEEKEND
AMIDST LOW AMPLITUDE MID LVL FLOW BRINGING A FAIR AMOUNT OF SUN AND
CLIMO TEMPS...EVEN PERHAPS A WARMING TREND.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 12Z...MOST OF THE RAIN IS OVER THE WESTERN TERMINALS AT THIS
TIME. TIME HEIGHTS AND HRRR MODEL ARE IN REASONABLE AGREEMENT IN
MOVING THE PRECIP TOWARD THE COAST WITH A FRONT THAT BASICALLY
WASHES OUT AFTER IT EXITS THE COAST THIS AFTERNOON. LOOK FOR
CONDITIONS TO BOUNCE FROM VFR TO MVFR IN THE PRECIP. ALL AREAS WILL
BECOME VFR BY EARLY AFTERNOON AS THE BULK OF THE DEEP MOISTURE
SHIFTS TO THE SOUTHEAST. A STRONGER FRONT MOVES IN TONIGHT. NO
WEATHER ASSOCIATED WITH IT OTHER THAN A WIND SHIFT TO THE NORTH AND
A VFR STRATA CU CEILING.
EXTENDED OUTLOOK...VFR TUESDAY AND WEDNESDAY. SHOWERS AND SUB-VFR
CONDITIONS LIKELY THURSDAY AND FRIDAY AS LOW PRESSURE MOVES UP THE
ATLANTIC COAST.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM MONDAY...SEAS ARE FALLING VERY SLOWLY...BUT BASED ON 6
A.M. BUOY OBS IN THE CAPE FEAR VICINITY THE ADVISORY WILL NEED TO
REMAIN POSTED THROUGH AT LEAST 9 A.M.
NO SIGNIFICANT CHANGES HAVE BEEN MADE TO THE FORECAST. PREVIOUS
DISCUSSION FROM 300 AM FOLLOWS...
A COLD FRONT ACROSS INTERIOR NORTH CAROLINA WILL DROP SOUTHWARD
SLOWLY DURING THE DAY...REACHING THE NORTH AND SOUTH CAROLINA
COASTAL WATERS BY LATE AFTERNOON. WINDS WILL GRADUALLY VEER FROM
SOUTHWEST TO WEST IN THE VICINITY OF THIS RATHER WEAK FRONT. SHOWER
AND THUNDERSTORM ACTIVITY WILL OCCUR THIS MORNING MAINLY NORTH OF
MYRTLE BEACH...WITH SHOWERS BECOMING VERY ISOLATED IF NOT TOTALLY
ABSENT THIS AFTERNOON. A SECOND BUT MUCH STRONGER COLD FRONT WILL
ARRIVE FROM THE NORTH AFTER MIDNIGHT TONIGHT...ACCOMPANIED BY A
SHIFT TO NORTH WINDS WITH AN INCREASE IN SPEEDS TO 15-20 KNOTS. AT
THIS TIME IT DOESN`T APPEAR SMALL CRAFT ADVISORIES WILL BE
NEEDED...BUT CONDITIONS WILL CERTAINLY DETERIORATE LATE.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...MAIN AREA OF HIGH PRESSURE BUILDING IN FROM THE
NORTH AND WEST IN A FAIRLY RESTRAINED MANNER ON TUESDAY KEEPING THE
CENTER UP IN THE GREAT LAKES. A SMALLER AND POORLY DEFINED CENTER
SLIPS INTO THE CAROLINAS HOWEVER KEEPING GRADIENT VERY LIGHT LEADING
AND TAME WINDS OUT OF THE N/NE. SEAS BEGIN THE PERIOD STIRRED UP
FROM THE NEAR TERM BUT WILL QUICKLY ABATE. THE PARENT AIRMASS DRAWS
A LITTLE CLOSER WEDNESDAY PICKING UP AND SLIGHTLY VEERING THE WINDS.
AS THE HIGH SETTLES ACRS VA BY THE END OF THE PERIOD AND LOW
PRESSURE MARCHES EAST ACROSS THE GULF COAST THERE SHOULD BE AN
ADDITIONAL VEER AND SMALL INCREASE IN WINDS. THE SPEED AT WHICH THIS
HAPPENS IS A LITTLE UNCERTAIN.
.LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM MONDAY...MODERATELY STRONG SOUTHERN BRANCH FEATURE COMING
ACROSS THE GULF OF MEXICO ON THURSDAY WHILE WEST ATLANTIC HIGH
PRESSURE PROGRESSES EASTWARD BUT AT A SLOWER SPEED. THIS WILL
INCREASE THE GRADIENT UP AND DOWN THE SOUTHEAST COAST AND A SMALL
CRAFT ADVISORY WILL BE NEEDED. AS THE STORM SYSTEM TURNS TO THE NE
AND MOVES RIGHT UP THE CAROLINA COAST ON AN INLAND TRACK THE STRONG
SW FLOW WILL BE MAINTAINED IF NOT STRENGTHENED. EXPECT A FURTHER
BUILDING OF SEAS FROM ADDED FETCH DURATION IF NOTHING ELSE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EDT THIS MORNING FOR AMZ250-
252.
&&
$$
SYNOPSIS...TRA
NEAR TERM...MBB
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...43
AREA FORECAST DISCUSSION
NWS BISMARCK ND
547 PM CDT MON APR 1 2013
.UPDATE...
ISSUED AT 546 PM CDT MON APR 1 2013
LATEST SUITE OF SATELLITE IMAGERY/SURFACE OBSERVATIONS SHOWS
CLEAR SKIES ACROSS WESTERN AND CENTRAL NORTH DAKOTA WITH THE
EXCEPTION OF A SCT/BKN CUMULUS DECK OVER THE HIGHER TERRAIN IN THE
SOUTHWEST...IN CONJUNCTION WITH A LOW LEVEL BAROCLINIC ZONE.
TEMPERATURES WERE IN THE 50S ACROSS SOUTHEAST MONTANA...WITH
TEMPERATURES AROUND 40 IN OUR SOUTHWEST ZONES. OTHERWISE...A
1030MB SURFACE HIGH PRESSURE SITS OVER NORTHERN NORTH DAKOTA THIS
EVENING PRODUCING CLEAR SKIES AND LIGHT WINDS.
FURTHER UPSTREAM...WATER VAPOR IMAGERY SHOWS A WEAK SHORTWAVE
TROUGH ALOFT OVER NORTHEAST SASKATCHEWAN ALONG WITH A SURFACE
REFLECTION/SURFACE TROUGH PER MSAS...ALL MOVING SOUTHEAST WITH
TIME. THIS SHORTWAVE IS FORECAST TO MOVE TO LAKE WINNIPEG BY 06Z
TUESDAY...THEN INTO NORTHERN MINNESOTA BY 12Z TUESDAY. BEST UPWARD
VERTICAL MOTION/H85-H3 OMEGA FIELD IS FORECAST OVER SOUTHERN
MANITOBA DURING THE 06Z-12Z TUESDAY TIME FRAME. HOWEVER THE 18Z
NAM/GFS AND LATEST RAP MODEL PRODUCE A SWATH OF 80 TO 90 PERCENT
H85-H7 RH LATER TONIGHT ASSOCIATED WITH THIS SHORTWAVE. THE
NAM/GFS ALSO PAINT LIGHT QPF OF 0.01 COVERING PORTIONS OF BOTTINEAU
AND ROLETTE COUNTIES BETWEEN 09Z AND 12Z TUESDAY. THE LATEST RAP
MODEL KEEPS THE PRECIPITATION JUST EAST OF BOTTINEAU/ROLETTE
COUNTIES. OBSERVATIONS AND PAST WEATHER IN LOCATION OF CURRENT
SHORTWAVE DOES REVEAL A POCKET OF LOW/MID LEVEL CLOUDS AND A BRIEF
PERIOD OF ISOLATED FLURRIES.
FOR THIS UPDATE...HAVE COLLABORATED WITH NEIGHBORING OFFICES TO
INCREASE THE SKY GRIDS FOR THE NORTHEAST TONIGHT...BUT HOLD OFF
ON ANY MENTION OF PRECIPITATION AS BEST VERTICAL MOTION IS
FORECAST NORTH/EAST. WILL AWAIT THE 00Z MODEL RUNS AND KEEP A
CLOSE EYE ON THE RAP MODEL THIS EVENING FOR ANY CHANGES. UNTIL
OBSERVATIONS SUGGEST SOMETHING DEVELOPING CLOSER TO OUR NORTHERN
BORDER...WILL STAY THE COURSE WITH THE DRY FORECAST. REST OF
FORECAST IS IN GOOD SHAPE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 346 PM CDT MON APR 1 2013
HIGH PRESSURE WILL GRADUALLY SHIFT EAST OF THE REGION THROUGH THE
PERIOD. DRY CONDITIONS WILL PREVAIL AS A RESULT. BELOW NORMAL
TEMPERATURES WILL CONTINUE THIS AFTERNOON AND TONIGHT.
HOWEVER...RETURN FLOW DEVELOPING ACROSS THE REGION COMBINED WITH NO
SNOW PACK SOUTHWEST OF THE MISSOURI WILL ALLOW TUESDAY AFTERNOON
HIGHS TO BE ABOVE NORMAL SOUTHWEST. BELOW NORMAL TEMPERATURES WILL
CONTINUE NORTH AND EAST OF THE MISSOURI RIVER...WHERE THE SNOW PACK
IS LOCATED.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 346 PM CDT MON APR 1 2013
THE MAIN FORECAST CHALLENGES FOR THE EXTENDED PERIOD INCLUDE
PRECIPITATION CHANCES AND PRECIPITATION TYPE. 12Z SUITE OF MODEL
SOLUTIONS ARE IN AGREEMENT EARLY IN THE PERIOD...WITH SOLUTIONS
DIVERGING LATE THIS WEEK.
WARM AIR ADVECTION WILL CONTINUE ACROSS THE AREA TUESDAY NIGHT AND
WEDNESDAY AHEAD OF A UPPER LEVEL WAVE/SURFACE LOW PRESSURE SYSTEM
THAT IS FORECAST TO PASS OVER NORTH DAKOTA. WARM H850
TEMPERATURES OF +6 TO +10C WILL BE FIRMLY IN PLACE WEDNESDAY AS
PRECIPITATION BEGINS ACROSS THE NORTHWEST AND SPREADS SOUTHEAST
ACROSS THE AREA WEDNESDAY. PRECIPITATION WILL BEGIN AS LIGHT
FREEZING RAIN AND TRANSITION TO LIGHT RAIN DURING WEDNESDAY
AFTERNOON. ACROSS THE SOUTHWEST...ISOLATED WEAK THUNDERSTORMS ARE
POSSIBLE...WHERE TEMPERATURES WILL BE IN THE 60S WITH SURFACE BASED
CAPE IN THE 100 TO 200 J/KG ADVERTISED BY THE 12Z NAM. BEFORE
ENDING WEDNESDAY EVENING...A TRANSITION FROM LIGHT RAIN TO A
WINTRY MIX OF SNOW...FREEZING RAIN...AND POSSIBLY SLEET WILL BE
SEEN AS A COLD FRONT MOVES SOUTH FROM CANADA.
COOLER TEMPERATURES WILL BE SEEN WEDNESDAY NIGHT AND THURSDAY...AS
COLD AIR COMMENCES FOLLOWING THE PASSAGE OF THE AFOREMENTIONED
COLD FRONT. HOWEVER...ACROSS THE SNOW LESS AREAS...TEMPERATURES
WILL BE WARMEST WITH TEMPERATURES IN 50S ON THURSDAY. FOR
LOCATIONS ACROSS THE SNOWPACK...TEMPERATURES WILL BE IN THE LOW TO
MID 30S.
STARTING FRIDAY...AN ACTIVE PERIOD OF WEATHER IS EXPECTED
TO START AS A SERIES OF UPPER LEVEL WAVES AND THEIR SURFACE
REFLECTIONS ARE PROGGED TO MOVE ACROSS THE AREA IN NORTHWESTERLY
FLOW. UNCERTAINTY REMAINS IN THE PLACEMENT AND TYPE OF
PRECIPITATION ACROSS NORTH DAKOTA...AS THERE IS DISAGREEMENT
AMONGST THE 12Z MODEL SOLUTIONS. THE 12Z GEM/GFS ARE MORE
AGGRESSIVE WITH QPF ACROSS THE WEST AND CENTRAL VERSUS THE 12Z EC
SOLUTION. THE 12Z EC KEEPS THE BULK OF THE PRECIPITATION FURTHER
NORTH ACROSS SOUTHERN MANITOBA AND SASKATCHEWAN.
AT THIS TIME HAVE UTILIZED A BLEND OF MODEL SOLUTIONS DURING THE
FRIDAY TO MONDAY PERIOD...WHICH GIVE A WIDE ARRAY OF PRECIPITATION
TYPES. AT THIS MOMENT...IT LOOKS LIKE THE SOUTHWEST WILL REMAIN
MOSTLY RAIN AS IT REMAINS IN THE WARM H850 TEMPERATURES OF +4 TO
+8 C. ELSEWHERE...A LIGHT WINTRY MIX OF SNOW...FREEZING RAIN...AND
POSSIBLY SLEET MAY OCCUR. BY SUNDAY EVENING AND
MONDAY...PRECIPITATION TYPE WILL BE SNOW...AS ANOTHER COLD FRONT
DROPS SOUTH OUT OF CANADA. FOLLOWING THE PASSAGE OF THE COLD
FRONT...COLDER H850 TEMPERATURES OF -8 TO -12 C ARE POSSIBLE AT
THE BEGINNING OF NEXT WEEK...AS A SURFACE HIGH PRESSURE STARTS TO
MOVE SOUTH.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING...
ISSUED AT 546 PM CDT MON APR 1 2013
GENERALLY CLEAR SKIES/VFR CONDITIONS WILL PREVAIL OVER WESTERN AND
CENTRAL NORTH DAKOTA THROUGH THE 00Z TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...TM
LONG TERM...LTH
AVIATION...KS
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1113 AM MDT MON APR 1 2013
.UPDATE...
ISSUED AT 1047 AM MDT MON APR 1 2013
CURRENT SURFACE ANALYSIS SHOWS CANADIAN HIGH PRESSURE OVER EASTERN
PORTIONS OF THE DAKOTAS. UPPER LEVEL ANALYSIS SHOWS LARGE TROF
CENTERED OVER THE GREAT LAKES REGION...WITH RIDGING OVER THE
PACIFIC NW. A CUTOFF LOW IS SLOWLY MOVING EAST-SOUTHEAST ACROSS
NV. SKIES CURRENTLY RANGE FROM SUNNY ACROSS NORTHEAST WY AND
SOUTHWESTERN SD TO PARTLY TO MOSTLY CLOUDY FROM NORTHWESTERN INTO
CENTRAL SD. BAND OF CLOUDS IS SLOWLY DISSIPATING ACROSS THESE
AREAS...WITH MOSTLY SUNNY SKIES EXPECTED BY EARLY AFTERNOON.
NEAR TO SLIGHTLY BELOW AVERAGE TEMPERATURES CAN BE EXPECTED THIS
AFTERNOON...WITH HIGHS IN THE MID 40S TO MID 50S...WARMEST OVER
NORTHEASTERN WY AND COOLEST OVER FAR EASTERN AREAS. WINDS WILL
REMAIN RELATIVELY LIGHT AND VARIABLE THROUGH THE AFTERNOON. MAIN
ADJUSTMENTS TO THE FORECAST WERE TO TWEAK CLOUD COVER AND WINDS
FOR THE REST OF TODAY.
&&
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
ISSUED AT 240 AM MDT MON APR 1 2013
ACTIVE PROGRESSIVE NORTHERN STREAM FLOW WILL DOMINATE
THE WEATHER IN THE PERIOD...WITH A LARGE SCALE SPLIT FLOW REGIME.
THIS WILL OFFER WARM DOWNSLOPE PAC ORIGIN FLOW INTO THE AREA...ESP
TUE. GREAT LAKES UPPER TROUGH WILL SLOWLY SHIFT EAST WITH DEEP LAYER
RIDGING DEVELOPING TODAY...INITIATING WAA BY THIS AFTERNOON OVER THE
WESTERN FA. THE ONLY FORECAST CONCERN TODAY WILL BE THE EVOLUTION OF
THE CURRENT STRATUS IN PLACE ACROSS THE EASTERN FA...WHICH MAY
HAMPER T RISES. THE ONLY FORECAST MODELS WHICH SEEMS TO HAVE ANY
SORT OF HANDLE ON THE EXISTENCE OF CLOUD COVER IS THE RAP AND LOCAL
WRF...WITH ALL OTHER GUIDANCE REMAINING TOO DRY IN THE LL/S.
RAP/LOCAL WRF BOTH INDICATE THAT INCREASING DRY WESTERLY FLOW AT THE
BL TOP SHOULD HELP ERODE CLOUD COVER WEST TO EAST THROUGH MORNING
AND TRIED TO INCORPORATE THIS IDEA INTO THE GRIDS. ONCE CLOUDS
CLEAR...SKIES WILL REMAIN MOSTLY CLEAR THROUGH THE PERIOD...SAVE FOR
SOME PASSING CIRRUS.
TEMPS WILL REMAIN ON THE COOL SIDE ACROSS MOST OF THE AREA
TODAY...WITH THE SD PLAINS BEING THE COOLEST. NE WY WILL SEE QUICK
RESPONSE TO ENSUING WAA WITH MANY PLACES EXPECTED TO BE IN THE 50S
THERE. HAVE ADJUSTED TEMPS UP SOME...GIVEN LATEST BLENDED GUIDANCE
WITH STRONG INSOLATION EXPECTED. MUCH WARMER CONDITIONS EXPECTED
TUE...WITH 50S AND 60S COMMON MOST PLACES. HAVE WARMED MOST PLACES
A FEW DEGREES TUE...ESP NE WY. STRONG INSOLATION SHOULD SUPPORT
SUPERADIABATS AT MOST LOCATIONS GIVEN WEAK LL FLOW...WITH TEMPS
WARMER THAN CURRENT FORECAST HIGHS CERTAINLY POSSIBLE. THE NEXT
NORTHERN STREAM IMPULSE WILL APPROACH THE REGION TUE...WITH WAA
RAMPING UP...AS WELL AS LL SOUTHERLY FLOW TUE NIGHT. THIS SHOULD
KEEP TEMPS UP AT MANY PLACES OVERNIGHT TUE...GIVEN TURBULENT
MIXING...ESP IN THE LEE DOWNSLOPE AREAS OF THE BH.
.LONG TERM...WEDNESDAY THROUGH SUNDAY
ISSUED AT 240 AM MDT MON APR 1 2013
UPPER LEVEL RIDGE FLATTENS LATE WEDNESDAY AS A COLD FRONT CROSSES
THE AREA...BRINGING A CHANCE FOR RAIN SHOWERS AND AN ISOLATED
THUNDERSTORM. RAIN SHOWERS WILL LINGER INTO THURSDAY...MAINLY ACROSS
NORTHERN PORTIONS OF THE AREA. A MORE UNSETTLED PATTERN WILL DEVELOP
BY THE WEEKEND AS A LARGE UPPER TROF DEVELOPS OVER THE WEST COAST
AND A SERIES OF DISTURBANCES MOVE ACROSS THE NORTHERN PLAINS IN WEST
TO SOUTHWEST FLOW. TEMPERATURES WILL GENERALLY STAY ABOVE AVERAGE
LATE IN THE WEEK AND LIKELY DROP CLOSER TO AVERAGE LEVELS DURING THE
WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1109 AM MDT MON APR 1 2013
LEFTOVER MARGINALLY MVFR CIGS FROM KPHP TO KVTN WILL MOVE SLOWLY
EAST AND DISSIPATE EARLY THIS AFTERNOON AS BOUNDARY LAYER MIXES
OUT. SOME VFR CU IS EXPECTED FROM K2WX TO KVTN FOR THE AFTERNOON.
OTHERWISE...VFR CONDITIONS WILL BE THE RULE THROUGH THE PERIOD.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...26
SHORT TERM...JC
LONG TERM...15
AVIATION...HELGESON
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1047 AM MDT MON APR 1 2013
.UPDATE...
ISSUED AT 1047 AM MDT MON APR 1 2013
CURRENT SURFACE ANALYSIS SHOWS CANADIAN HIGH PRESSURE OVER EASTERN
PORTIONS OF THE DAKOTAS. UPPER LEVEL ANALYSIS SHOWS LARGE TROF
CENTERED OVER THE GREAT LAKES REGION...WITH RIDGING OVER THE
PACIFIC NW. A CUTOFF LOW IS SLOWLY MOVING EAST-SOUTHEAST ACROSS
NV. SKIES CURRENTLY RANGE FROM SUNNY ACROSS NORTHEAST WY AND
SOUTHWESTERN SD TO PARTLY TO MOSTLY CLOUDY FROM NORTHWESTERN INTO
CENTRAL SD. BAND OF CLOUDS IS SLOWLY DISSIPATING ACROSS THESE
AREAS...WITH MOSTLY SUNNY SKIES EXPECTED BY EARLY AFTERNOON.
NEAR TO SLIGHTLY BELOW AVERAGE TEMPERATURES CAN BE EXPECTED THIS
AFTERNOON...WITH HIGHS IN THE MID 40S TO MID 50S...WARMEST OVER
NORTHEASTERN WY AND COOLEST OVER FAR EASTERN AREAS. WINDS WILL
REMAIN RELATIVELY LIGHT AND VARIABLE THROUGH THE AFTERNOON. MAIN
ADJUSTMENTS TO THE FORECAST WERE TO TWEAK CLOUD COVER AND WINDS
FOR THE REST OF TODAY.
&&
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
ISSUED AT 240 AM MDT MON APR 1 2013
ACTIVE PROGRESSIVE NORTHERN STREAM FLOW WILL DOMINATE
THE WEATHER IN THE PERIOD...WITH A LARGE SCALE SPLIT FLOW REGIME.
THIS WILL OFFER WARM DOWNSLOPE PAC ORIGIN FLOW INTO THE AREA...ESP
TUE. GREAT LAKES UPPER TROUGH WILL SLOWLY SHIFT EAST WITH DEEP LAYER
RIDGING DEVELOPING TODAY...INITIATING WAA BY THIS AFTERNOON OVER THE
WESTERN FA. THE ONLY FORECAST CONCERN TODAY WILL BE THE EVOLUTION OF
THE CURRENT STRATUS IN PLACE ACROSS THE EASTERN FA...WHICH MAY
HAMPER T RISES. THE ONLY FORECAST MODELS WHICH SEEMS TO HAVE ANY
SORT OF HANDLE ON THE EXISTENCE OF CLOUD COVER IS THE RAP AND LOCAL
WRF...WITH ALL OTHER GUIDANCE REMAINING TOO DRY IN THE LL/S.
RAP/LOCAL WRF BOTH INDICATE THAT INCREASING DRY WESTERLY FLOW AT THE
BL TOP SHOULD HELP ERODE CLOUD COVER WEST TO EAST THROUGH MORNING
AND TRIED TO INCORPORATE THIS IDEA INTO THE GRIDS. ONCE CLOUDS
CLEAR...SKIES WILL REMAIN MOSTLY CLEAR THROUGH THE PERIOD...SAVE FOR
SOME PASSING CIRRUS.
TEMPS WILL REMAIN ON THE COOL SIDE ACROSS MOST OF THE AREA
TODAY...WITH THE SD PLAINS BEING THE COOLEST. NE WY WILL SEE QUICK
RESPONSE TO ENSUING WAA WITH MANY PLACES EXPECTED TO BE IN THE 50S
THERE. HAVE ADJUSTED TEMPS UP SOME...GIVEN LATEST BLENDED GUIDANCE
WITH STRONG INSOLATION EXPECTED. MUCH WARMER CONDITIONS EXPECTED
TUE...WITH 50S AND 60S COMMON MOST PLACES. HAVE WARMED MOST PLACES
A FEW DEGREES TUE...ESP NE WY. STRONG INSOLATION SHOULD SUPPORT
SUPERADIABATS AT MOST LOCATIONS GIVEN WEAK LL FLOW...WITH TEMPS
WARMER THAN CURRENT FORECAST HIGHS CERTAINLY POSSIBLE. THE NEXT
NORTHERN STREAM IMPULSE WILL APPROACH THE REGION TUE...WITH WAA
RAMPING UP...AS WELL AS LL SOUTHERLY FLOW TUE NIGHT. THIS SHOULD
KEEP TEMPS UP AT MANY PLACES OVERNIGHT TUE...GIVEN TURBULENT
MIXING...ESP IN THE LEE DOWNSLOPE AREAS OF THE BH.
.LONG TERM...WEDNESDAY THROUGH SUNDAY
ISSUED AT 240 AM MDT MON APR 1 2013
UPPER LEVEL RIDGE FLATTENS LATE WEDNESDAY AS A COLD FRONT CROSSES
THE AREA...BRINGING A CHANCE FOR RAIN SHOWERS AND AN ISOLATED
THUNDERSTORM. RAIN SHOWERS WILL LINGER INTO THURSDAY...MAINLY ACROSS
NORTHERN PORTIONS OF THE AREA. A MORE UNSETTLED PATTERN WILL DEVELOP
BY THE WEEKEND AS A LARGE UPPER TROF DEVELOPS OVER THE WEST COAST
AND A SERIES OF DISTURBANCES MOVE ACROSS THE NORTHERN PLAINS IN WEST
TO SOUTHWEST FLOW. TEMPERATURES WILL GENERALLY STAY ABOVE AVERAGE
LATE IN THE WEEK AND LIKELY DROP CLOSER TO AVERAGE LEVELS DURING THE
WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 540 AM MDT MON APR 1 2013
MVFR CIGS WILL PERSIST ACROSS THE WESTERN SOUTH DAKOTA PLAINS
THROUGH THE MORNING HOURS BEFORE LIFTING AND SHIFTING EAST BY 18Z.
VFR CONDITIONS ARE THEN EXPECTED THROUGH TUESDAY MORNING.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...26
SHORT TERM...JC
LONG TERM...15
AVIATION...15
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
541 AM MDT MON APR 1 2013
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
ISSUED AT 240 AM MDT MON APR 1 2013
ACTIVE PROGRESSIVE NORTHERN STREAM FLOW WILL DOMINATE
THE WEATHER IN THE PERIOD...WITH A LARGE SCALE SPLIT FLOW REGIME.
THIS WILL OFFER WARM DOWNSLOPE PAC ORIGIN FLOW INTO THE AREA...ESP
TUE. GREAT LAKES UPPER TROUGH WILL SLOWLY SHIFT EAST WITH DEEP LAYER
RIDGING DEVELOPING TODAY...INITIATING WAA BY THIS AFTERNOON OVER THE
WESTERN FA. THE ONLY FORECAST CONCERN TODAY WILL BE THE EVOLUTION OF
THE CURRENT STRATUS IN PLACE ACROSS THE EASTERN FA...WHICH MAY
HAMPER T RISES. THE ONLY FORECAST MODELS WHICH SEEMS TO HAVE ANY
SORT OF HANDLE ON THE EXISTENCE OF CLOUD COVER IS THE RAP AND LOCAL
WRF...WITH ALL OTHER GUIDANCE REMAINING TOO DRY IN THE LL/S.
RAP/LOCAL WRF BOTH INDICATE THAT INCREASING DRY WESTERLY FLOW AT THE
BL TOP SHOULD HELP ERODE CLOUD COVER WEST TO EAST THROUGH MORNING
AND TRIED TO INCORPORATE THIS IDEA INTO THE GRIDS. ONCE CLOUDS
CLEAR...SKIES WILL REMAIN MOSTLY CLEAR THROUGH THE PERIOD...SAVE FOR
SOME PASSING CIRRUS.
TEMPS WILL REMAIN ON THE COOL SIDE ACROSS MOST OF THE AREA
TODAY...WITH THE SD PLAINS BEING THE COOLEST. NE WY WILL SEE QUICK
RESPONSE TO ENSUING WAA WITH MANY PLACES EXPECTED TO BE IN THE 50S
THERE. HAVE ADJUSTED TEMPS UP SOME...GIVEN LATEST BLENDED GUIDANCE
WITH STRONG INSOLATION EXPECTED. MUCH WARMER CONDITIONS EXPECTED
TUE...WITH 50S AND 60S COMMON MOST PLACES. HAVE WARMED MOST PLACES
A FEW DEGREES TUE...ESP NE WY. STRONG INSOLATION SHOULD SUPPORT
SUPERADIABATS AT MOST LOCATIONS GIVEN WEAK LL FLOW...WITH TEMPS
WARMER THAN CURRENT FORECAST HIGHS CERTAINLY POSSIBLE. THE NEXT
NORTHERN STREAM IMPULSE WILL APPROACH THE REGION TUE...WITH WAA
RAMPING UP...AS WELL AS LL SOUTHERLY FLOW TUE NIGHT. THIS SHOULD
KEEP TEMPS UP AT MANY PLACES OVERNIGHT TUE...GIVEN TURBULENT
MIXING...ESP IN THE LEE DOWNSLOPE AREAS OF THE BH.
.LONG TERM...WEDNESDAY THROUGH SUNDAY
ISSUED AT 240 AM MDT MON APR 1 2013
UPPER LEVEL RIDGE FLATTENS LATE WEDNESDAY AS A COLD FRONT CROSSES
THE AREA...BRINGING A CHANCE FOR RAIN SHOWERS AND AN ISOLATED
THUNDERSTORM. RAIN SHOWERS WILL LINGER INTO THURSDAY...MAINLY ACROSS
NORTHERN PORTIONS OF THE AREA. A MORE UNSETTLED PATTERN WILL DEVELOP
BY THE WEEKEND AS A LARGE UPPER TROF DEVELOPS OVER THE WEST COAST
AND A SERIES OF DISTURBANCES MOVE ACROSS THE NORTHERN PLAINS IN WEST
TO SOUTHWEST FLOW. TEMPERATURES WILL GENERALLY STAY ABOVE AVERAGE
LATE IN THE WEEK AND LIKELY DROP CLOSER TO AVERAGE LEVELS DURING THE
WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 540 AM MDT MON APR 1 2013
MVFR CIGS WILL PERSIST ACROSS THE WESTERN SOUTH DAKOTA PLAINS
THROUGH THE MORNING HOURS BEFORE LIFTING AND SHIFTING EAST BY 18Z.
VFR CONDITIONS ARE THEN EXPECTED THROUGH TUESDAY MORNING.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...JC
LONG TERM...15
AVIATION...15
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
241 AM MDT MON APR 1 2013
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
ISSUED AT 240 AM MDT MON APR 1 2013
ACTIVE PROGRESSIVE NORTHERN STREAM FLOW WILL DOMINATE
THE WEATHER IN THE PERIOD...WITH A LARGE SCALE SPLIT FLOW REGIME.
THIS WILL OFFER WARM DOWNSLOPE PAC ORIGIN FLOW INTO THE AREA...ESP
TUE. GREAT LAKES UPPER TROUGH WILL SLOWLY SHIFT EAST WITH DEEP LAYER
RIDGING DEVELOPING TODAY...INITIATING WAA BY THIS AFTERNOON OVER THE
WESTERN FA. THE ONLY FORECAST CONCERN TODAY WILL BE THE EVOLUTION OF
THE CURRENT STRATUS IN PLACE ACROSS THE EASTERN FA...WHICH MAY
HAMPER T RISES. THE ONLY FORECAST MODELS WHICH SEEMS TO HAVE ANY
SORT OF HANDLE ON THE EXISTENCE OF CLOUD COVER IS THE RAP AND LOCAL
WRF...WITH ALL OTHER GUIDANCE REMAINING TOO DRY IN THE LL/S.
RAP/LOCAL WRF BOTH INDICATE THAT INCREASING DRY WESTERLY FLOW AT THE
BL TOP SHOULD HELP ERODE CLOUD COVER WEST TO EAST THROUGH MORNING
AND TRIED TO INCORPORATE THIS IDEA INTO THE GRIDS. ONCE CLOUDS
CLEAR...SKIES WILL REMAIN MOSTLY CLEAR THROUGH THE PERIOD...SAVE FOR
SOME PASSING CIRRUS.
TEMPS WILL REMAIN ON THE COOL SIDE ACROSS MOST OF THE AREA
TODAY...WITH THE SD PLAINS BEING THE COOLEST. NE WY WILL SEE QUICK
RESPONSE TO ENSUING WAA WITH MANY PLACES EXPECTED TO BE IN THE 50S
THERE. HAVE ADJUSTED TEMPS UP SOME...GIVEN LATEST BLENDED GUIDANCE
WITH STRONG INSOLATION EXPECTED. MUCH WARMER CONDITIONS EXPECTED
TUE...WITH 50S AND 60S COMMON MOST PLACES. HAVE WARMED MOST PLACES
A FEW DEGREES TUE...ESP NE WY. STRONG INSOLATION SHOULD SUPPORT
SUPERADIABATS AT MOST LOCATIONS GIVEN WEAK LL FLOW...WITH TEMPS
WARMER THAN CURRENT FORECAST HIGHS CERTAINLY POSSIBLE. THE NEXT
NORTHERN STREAM IMPULSE WILL APPROACH THE REGION TUE...WITH WAA
RAMPING UP...AS WELL AS LL SOUTHERLY FLOW TUE NIGHT. THIS SHOULD
KEEP TEMPS UP AT MANY PLACES OVERNIGHT TUE...GIVEN TURBULENT
MIXING...ESP IN THE LEE DOWNSLOPE AREAS OF THE BH.
&&
.LONG TERM...WEDNESDAY THROUGH SUNDAY
ISSUED AT 240 AM MDT MON APR 1 2013
UPPER LEVEL RIDGE FLATTENS LATE WEDNESDAY AS A COLD FRONT CROSSES
THE AREA...BRINGING A CHANCE FOR RAIN SHOWERS AND AN ISOLATED
THUNDERSTORM. RAIN SHOWERS WILL LINGER INTO THURSDAY...MAINLY ACROSS
NORTHERN PORTIONS OF THE AREA. A MORE UNSETTLED PATTERN WILL DEVELOP
BY THE WEEKEND AS A LARGE UPPER TROF DEVELOPS OVER THE WEST COAST
AND A SERIES OF DISTURBANCES MOVE ACROSS THE NORTHERN PLAINS IN WEST
TO SOUTHWEST FLOW. TEMPERATURES WILL GENERALLY STAY ABOVE AVERAGE
LATE IN THE WEEK AND LIKELY DROP CLOSER TO AVERAGE LEVELS DURING THE
WEEKEND.
&&
.AVIATION...FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT
ISSUED AT 240 AM MDT MON APR 1 2013
MVFR AND LOCAL IFR CIGS WILL PERSIST ACROSS WESTERN SOUTH DAKOTA
THROUGH THE MORNING HOURS BEFORE LIFTING AND SHIFTING EAST BY 18Z.
VFR CONDITIONS ARE THEN EXPECTED THROUGH TUESDAY MORNING.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...JC
LONG TERM...15
AVIATION...15
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
329 PM CDT MON APR 1 2013
.SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)...ANOTHER ONE OF THESE
FORECASTS WHERE MESO-SCALE INFLUENCES MAY PLAY HAVOC ON WHAT
TRANSPIRES TONIGHT. MAIN FLY IN OINTMENT NOW IS THAT LOTS OF
STRATUS IS JUST ACROSS THE RIVER AND TEMPERATURES OUT WEST ARE NOT
THAT WARM...SO SEA BREEZE LIMITED OUT THERE AS WELL AS DAYTIME
HEATING. THUS...CONVERGING BOUNDARIES LIKE LAST NIGHT NOT PRESENT
AND STORMS MAY HAVE A HARD TIME FIRING UP DIRECTLY WEST OF
FORECAST AREA. HOWEVER...STORMS ARE DEVELOPING FARTHER NORTHWEST
OF STRATUS DECK (HAVE A LONG WAY TO GO THOUGH). STILL AM GOING
TO GO WITH LOW CHANCE POPS NEAR RIO GRANDE AND DIMINISH THEM
FARTHER EAST. THING THAT HELPS CONVECTION TO DEVELOP IS EASTERLY
UPSLOPE FLOW SO DO NOT WANT TO GO TOO LOW ON POPS (ESPECIALLY WITH
SLIGHT RISK IN AREA)...AND WITH SPC 4 KM MODEL AND HRRR MODEL
SHOWING ACTIVITY MOVING IN THERE. OTHERWISE...TEMPERATURES SHOULD
BE SIMILAR TO LAST NIGHT...EXCEPT WHERE CONVECTION COULD COOL
AIR SOME. NO SIGNIFICANT FOG EXPECTED.
UPPER LEVEL JET IMPACTS AREA ON TUESDAY AS CAP BREAKS/WEAKENS. AM
GOING HIGH CHANCE POPS EASTERN AREAS...TAD LOWER OUT WEST. MORE
CLOUDS AND RAIN-COOLED AIR MEANS LOWER TEMPERATURES TUESDAY. SOME
JET DYNAMICS REMAIN TUESDAY NIGHT AS FRONT APPROACHES...SO PRETTY
MUCH HAVE KEPT POPS SIMILAR TO PREVIOUS FORECAST WITH SLIGHT
ADJUSTMENT OF HIGHER POPS A BIT MORE TOWARD THE NORTHEAST (AREA
ADJUSTEMENT...STILL NO MORE THAN 70 POPS). WITH COOLER AIR
REMAINING NORTH OF AREA (BUT PROBABLY SOME CONVECTION AROUND
COOLING THINGS OFF)...WILL GO A BIT COOLER TUESDAY NIGHT THAN
TONIGHT. SPECIAL WEATHER STATEMENT HAS BEEN ISSUED TO HIGHLIGHT
UPCOMING EVENT.
&&
.MARINE (TONIGHT THROUGH TUESDAY NIGHT)...SEA FOG ALBEIT LIGHT
REMAINS IN THE FORECAST AS VISIBLE SATELLITE AND OBSERVATIONS SHOW
SOME OUT THERE. OVERALL VISIBILITIES SHOULD REMAIN ABOVE 2 NM.
GENERALLY WEAK TO MODERATE ESE/SE FLOW THROUGH THE PERIOD. RAIN
CHANCES INCREASE MAINLY LATE TUESDAY AND TUESDAY NIGHT.
&&
.LONG TERM (WEDNESDAY THROUGH SUNDAY)...OVERALL TREND CONTINUES
ABUNDANT GULF MOISTURE ACROSS THE REGION WITH PWATS 1.3 TO 1.5
INCHES...WHICH IS JUST OVER 75 PERCENT OF NORMAL PWATS FOR THIS TIME
OF YEAR. TIMING OF THE FRONT STILL REMAINS A CHALLENGE ALTHOUGH
MODEST AGREEMENT BETWEEN THE EURO/CANADIAN/NAM AROUND 00Z...WITH THE
GFS LAGGING A FEW HOURS BEHIND. A PREFRONTAL WIND SHIFT SHOULD TAKE
PLACE BETWEEN 18Z-00Z. WITH MULTIPLE SHORTWAVES ROUNDING THE
SOUTHERN PERIPHERY OF THE MIDLEVEL LOW //POSITIONED OVER THE CENTRAL
PLAINS//...CONTINUED HIGH END CHANCE TO LIKELY POPS GOING INTO
WEDNESDAY...WITH MOST ACTIVITY IN THE MORNING BEING MORE OF A SHOWER
ACTIVITY UNDER A WEAK CAP. HOWEVER...DID CONTINUE THUNDER WORDING AS
A VORT MAX AND 60 KNOT JET MOVE OVER THE AREA. DID SHOW THE INCREASE
IN CHANCES INTO THE AFTERNOON AS FURTHER COOLING IN THE MIDLEVELS
TAKES PLACE WITH THE FRONT SLOWLY MOVING SOUTHWARD. CONCERN DOES
EXIST IN THE AFTERNOON TO EARLY EVENING FOR STRONG TO SEVERE AS
LAPSE RATES STEEPEN WITH LI VALUES OF -7C TO -9C. HOWEVER...THE
ONSHORE IS WEAK TO FEED INTO ANY STORMS. CURRENTLY IF ANYTHING
DEVELOPS INTO THE STRONG TO SEVERE CATEGORY...SHOULD BE MORE OF
PULSE STORMS...WITH BETTER CHANCES ALONG THE FRONT ITSELF. WILL
CONTINUE TO MONITOR THE DEVELOPMENT OF THIS WEATHER EVENT. MOISTURE
AND THE MIDLEVEL LOW PULLS TO THE NORTHEAST WITH DRYING FROM WEST TO
EAST LATE WEDNESDAY INTO THURSDAY WITH HIGH PRESSURE ENTERING THE
REGION. QUIET WEATHER TO PERSIST INTO THE WEEKEND WITH A ONSHORE
FLOW DEVELOPING SATURDAY. TEMPERATURES TO COOL INTO THE 70S AREAWIDE
THURSDAY...WITH A WARMING TREND INTO THE WEEKEND UNDER MOSTLY CLEAR
TO PARTLY CLOUDY SKIES.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 68 82 69 81 55 / 10 50 50 70 40
VICTORIA 66 80 66 76 52 / 10 50 70 70 40
LAREDO 67 86 70 83 58 / 40 30 30 40 10
ALICE 68 86 69 83 55 / 10 50 50 60 30
ROCKPORT 68 77 68 75 55 / 10 50 60 70 40
COTULLA 65 83 67 78 53 / 30 30 50 50 10
KINGSVILLE 67 84 69 82 55 / 10 50 40 60 40
NAVY CORPUS 68 78 69 76 58 / 10 50 50 70 40
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
GW/86...SHORT TERM
CB/85...LONG TERM
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
208 PM CDT MON APR 1 2013
.SHORT TERM /NOW THROUGH TUESDAY NIGHT/...THE AREA REMAINS IN
QUASI-ZONAL FLOW ALOFT WITH AN UPPER LEVEL TROUGH LOCATED OVER THE
GREAT BASIN AND A WEAK IMPULSE RIDING WESTERLY FLOW IN NORTHERN
MEXICO SOUTH OF THE TEXAS BIG BEND. AT THE SURFACE...SOUTHEASTERLY
FLOW CONTINUES TO ADVECT MOISTURE FROM THE GULF OF MEXICO WITH A
COLD FRONT LOCATED ACROSS OKLAHOMA AND THE TEXAS PANHANDLE. A
1020MB HIGH IS LOCATED ACROSS THE ARKLAMISS.
FOR THE REST OF THE AFTERNOON AND INTO THIS EVENING...WILL CONTINUE
TO SEE CLOUDS BREAK UP AS MIXING AND DAYTIME HEATING CONTINUES.
THICKER STRATOCU RESIDES OVER ZAPATA/JIM HOGG/STARR COUNTIES AND MAY
BE A LITTLE HARDER TO BREAK UP CLOUDS IN THIS AREA. EVEN THOUGH
THICK CLOUDS ARE LOCATED HERE...TEMPERATURES HAVE WARMED NICELY AND
ARE ACTUALLY ABOVE FORECASTED HOURLY TEMPERATURES BUT LOOK GOOD FOR
THE HIGHS THIS AFTERNOON. WEAK IMPULSE TO OUR WEST IS FORECAST TO
SPARK CONVECTION ON THE SIERRA MADRE LATER THIS AFTERNOON AS IT
MOVES EAST. LATEST HRRR AND SPC 4KM WRF CONTINUE TO ROLL CONVECTION
OFF THE HIGHER TERRAIN AND MAKE A RUN AT OUR WESTERN ZONES. CURRENT
20 POPS OUT WEST LOOK GOOD FOR THIS EVENING AND MADE ONLY MINOR
ADJUSTMENTS TO MOVE JUST A LITTLE EASTWARD. ANY STORMS THAT DO CREEP
INTO OUR AREA WILL QUICKLY DISSIPATE TOWARDS MID EVENING AS BOUNDARY
LEVEL STABILIZES.
FOR TONIGHT...LOW CLOUDS WILL MOVE BACK IN ON SOUTHEASTERLY LOW
LEVEL WINDS BY MID TO LATE EVENING. NAM12/RAP/HRRR SHOW SIGNALS OF
SEA FOG DEVELOPING AND/OR ADVECTING IN TO THE COASTAL AREAS
OVERNIGHT. ADDED AREAS OF FOG ALONG THE COASTLINE WITH PATCHY FOG
INLAND. WILL HOLD OFF ON ANY DENSE FOG ADVISORY AT THIS TIME AND LET
SWING SHIFT MAKE THE CALL. INCREASED LOW TEMPERATURES SLIGHTLY WITH
EXPECTED ABUNDANCE OF LOW CLOUDS AND LOOKING AT MAINLY UPPER 60S TO
LOWER 70S.
FOR TUESDAY...WE WILL START OUT WITH THOSE LOW CLOUDS AND WILL BREAK
OUT AND DISSIPATE BY LATE MORNING. MIXING WILL TAKE PLACE BY MID
MORNING WITH GUSTY WINDS BY LATE MORNING. ANOTHER IMPULSE IS PROGGED
TO MOVE ACROSS THE AREA EARLY TUESDAY AFTERNOON. THERE IS PLACEMENT
ISSUES BETWEEN THE NAM AND GFS WITH THE NAM FURTHER NORTH AND THE
GFS IS ACROSS THE NORTHERN PORTION OF THE AREA AND IS WEAKER THAN
THE PREVIOUS RUN. KEPT POPS AS IS AND JUST TWEAKED LOCATION BASED ON
12Z GFS. A STRONG TO SEVERE STORM IS POSSIBLE GIVEN THE
THERMODYNAMIC ENVIRONMENT.
FOR TUESDAY NIGHT...THAT IMPULSE IS WELL NORTH OF THE AREA WITH JUST
A FEW SHOWERS LEFT OVER IN THE COASTAL WATERS. ATMOSPHERE WILL
STABILIZE RATHER RAPIDLY AFTER SUNSET WITH SKIES BECOMING CLOUDY
ONCE AGAIN. COLD FRONT WILL SAG INTO NORTH CENTRAL TEXAS WITH A SFC
LOW SOUTH OF THE TEXAS BIG BEND. CLOUDS WILL KEEP LOWS
UP...COMPARABLE TO TONIGHT.
.LONG TERM /WEDNESDAY THROUGH MONDAY/...12Z MODEL RUN REMAINS
PERSISTENT ON THE TRACK AND STRENGTH OF THE MID TO UPPER LEVEL
TROUGH CURRENTLY OVER THE GREAT BASIN. BY 18Z WEDNESDAY GFS PLACES
THE UPPER TROUGH AXIS ACROSS NORTHWEST TEXAS AROUND 18Z WITH ITS
ASSOCIATED COLD FRONT APPROACHING THE NORTHERN PORTIONS OF THE
CWA. LARGE SCALE ASCENT COUPLED WITH LOW LEVEL CONVERGENCE ALONG
THE FRONT SHOULD BE THE COMBINATION NEEDED TO BRING ABOUT THE
CHANCE OF RAIN WE HAVE SEEN IN A WHILE. MODEST LOW LEVEL MOISTURE
WILL BE IN PLACE AND A LATE AFTERNOON FRONTAL PASSAGE SHOULD ALLOW
FOR SURFACE HEATING TO EXCEED GUIDANCE VALUES. SPC MAINTAINS
GENERAL THUNDERSTORM CHANCES FOR WEDNESDAY BUT CAN NOT RULE OUT
ISOLATED SEVERE STORMS AS THE ATMOSPHERE BECOMES INCREASINGLY
UNSTABLE. A DAY TO DAY ANALYSIS TO TAKE PLACE BEFORE WE ADD SEVERE
WORDING INTO THE FORECAST/GRIDS. POP GUIDANCE REMAINS AT LOW END
CHANCE BUT THIS MIGHT BE ON THE LOW END WITH DYNAMICS LOOKING A
BETTER THEN YESTERDAY AT THIS TIME. KEEP WED AND WEDNESDAY NIGHT
POPS CLOSE TO THE PREVIOUS FORECAST. AS MENTIONED TEMPERATURES
SHOULD CLIMB AHEAD OF THE COLD FRONT WITH A LATE AFTERNOON OR
EARLY EVENING PASSAGE. FORECAST HIGHS TO REMAIN ABOVE GUIDANCE
VALUES ESPECIALLY IF WE SEE MORE SUN PEAK THROUGH.
TROUGH AXIS AND SURFACE LOW PRESSURE QUICKLY EXITS TO THE EAST
THURSDAY MORNING. HUNG ON TO LOW POPS ACROSS THE COASTAL COUNTIES
BEFORE ENDING THURSDAY AFTERNOON AS THIS SYSTEM OPENS AND PUSHES
TO THE EAST. FAIR WEATHER ENSUES THURSDAY AFTERNOON INTO FRIDAY AS
SHORTWAVE RIDGING BUILDS OVERHEAD. COOL TO MILD TEMPERATURES
THURSDAY MORNING WITH SOME RECOVERY THURSDAY WITH HIGHS DROPPING
TO SLIGHTLY EARLY APRIL NORMALS.
GFS HAS BEEN INDICATING A QUICK RETURN OF GULF MOISTURE FRIDAY
NIGHT INTO SATURDAY. A WEAK DISTURBANCE IN THE ZONAL FLOW HAS BEEN
SEEN THE LAST FEW RUNS. ALTHOUGH GUIDANCE IS SHOWING VERY LOW POPS
ON SATURDAY WILL UP THE CHANCES SLIGHTLY TO MENTION ISOLATED
SHOWERS. MODEST DIVERGENCE AND SUFFICIENT MOISTURE...IF OCCURS
MIGHT BE ENOUGH FOR A FEW SHOWERS. WIND MACHINE TO POSSIBLY TURN
ON SUNDAY AND MONDAY AS NEXT TROUGH AND SURFACE LOW DEVELOP OUT
WEST. TEMPERATURES TO CLIMB AS USUAL.
&&
.MARINE /NOW THROUGH TUESDAY/GENERALLY FAVORABLE MARINE CONDITIONS
ARE EXPECTED THROUGH TUESDAY NIGHT WITH MODERATE EASTERLY TO
SOUTHEASTERLY WINDS. CONDITIONS MAY APPROACH EXERCISE CAUTION
LEVELS ON THE GULF OF MEXICO TONIGHT. SEAS SHOULD REMAIN LOW TO
MODERATE.
WEDNESDAY THROUGH SUNDAY...COLD FRONT ON TAP FOR A LATE WEDNESDAY OR
WEDNESDAY EVENING PASSAGE. LIGHT WINDS IN ADVANCE OF THE FRONT TO
SHIFT AND INCREASE FROM THE NORTH. SMALL CRAFT ADVISORIES STILL
EXPECTED WITH A 6 TO 12 HOUR WINDOW OF STRONG NORTH FLOW WEDNESDAY
NIGHT INTO EARLY THURSDAY AS SURFACE LOW PRESSURE DEVELOPS EAST OF
PADRE ISLAND ALONG THE FRONT. WITH THE SURFACE LOW TRACKING EAST
FAIRLY QUICKLY THURSDAY NORTH TO NORTHEAST WINDS TO WEAKEN. WINDS
VEER FRIDAY TO THE EAST AND SOUTHEAST BY FRIDAY NIGHT BUT THE
RETURN FLOW REMAINS LIGHT TO MODERATE. MORE SUBSTANTIAL INCREASE
OF SOUTHEAST WINDS RESUME SUNDAY INTO MONDAY AS THE GRADIENT
TIGHTENS WITH LOW PRESSURE DEEPENING ACROSS WESTERN TEXAS AND
NORTHEAST MEXICO.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 70 82 68 82 / 10 20 30 40
BROWNSVILLE 69 84 68 84 / 10 20 30 40
HARLINGEN 70 86 68 84 / 10 20 20 40
MCALLEN 70 87 70 86 / 10 30 20 40
RIO GRANDE CITY 70 90 70 87 / 20 30 20 30
SOUTH PADRE ISLAND 69 76 68 78 / 10 20 30 40
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
55...SHORT TERM
59...LONG TERM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
311 AM CDT MON APR 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 311 AM CDT MON APR 1 2013
A BROAD/DEEP MID TO UPPER LEVEL TROUGH HAS SET UP ACROSS
SOUTHEASTERN CANADA WHILE AN AMPLIFYING RIDGE DEVELOPS ACROSS THE
WESTERN US. AT THE SURFACE...CYCLONIC FLOW PERSISTS ACROSS THE
GREAT LAKES AND UPPER MISSISSIPPI RIVER VALLEY AS A RIDGE OF HIGH
PRESSURE PUSHES DOWN TO THE SOUTHEAST ACROSS THE DAKOTAS. SKIES
HAVE MAINLY CLEARED OUT THOUGH A FEW CU STREAKS HAVE STUCK AROUND
NORTHERN WISCONSIN. SHOULD NOT SEE MUCH IN THE WAY OF CHANGES IN
THE PATTERN FOR TODAY AS THE RIDGE UNDERCUTS THE REGION TO THE
SOUTHWEST AND STRONGLY SUBSIDENT AIR SHOULD KEEP SKIES MAINLY
CLEAR.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 311 AM CDT MON APR 1 2013
WITH 850MB TEMPERATURES STAYING BETWEEN -10C TO -15C INTO
WEDNESDAY MORNING...TEMPERATURES WILL STAY WELL BELOW NORMAL OVER
THIS PERIOD. THE COLDEST MORNING WILL LIKELY BE ON WEDNESDAY
MORNING AS THE CORE OF THE RIDGE MOVES OVERHEAD AND ALLOWS FOR
IDEAL RADIATIONAL COOLING WITH CLEAR SKIES AND LIGHT WINDS. THINK
THAT SOME OF THE MODELS ARE LEANING TOWARD CLIMO AND HAVE SOME
HIGHER VALUES IN THERE...SO HAVE UNDERCUT LOWS THERE A BIT FOR
WEDNESDAY MORNING. TEMPERATURES WILL BE ON THE INCREASE ON
WEDNESDAY AS THE RIDGE AXIS MOVES IN FROM THE WEST AND 850MB
TEMPERATURES IMPROVE TO AROUND -2C TO 0C. HIGH TEMPERATURES WILL
STILL BE BELOW NORMAL BUT AT LEAST WILL BE TRENDING IN THE RIGHT
DIRECTION.
A MID LEVEL TROUGH WILL THEN TRACK ACROSS SOUTHERN CANADA
WEDNESDAY NIGHT INTO THURSDAY AND IN TURN BRING A SURFACE LOW
ALONG WITH IT. A COLD FRONT WILL EXTEND SOUTH OF THIS LOW AND WILL
APPROACH CENTRAL MINNESOTA/NORTHERN WISCONSIN EARLY THURSDAY
MORNING. THE BETTER LIFT/MOISTURE CONVERGENCE STILL APPEARS TO BE
OFF TO THE NORTHEAST CLOSER TO THE MID LEVEL/SURFACE LOW...SO IT
DOES NOT LOOK LIKE THERE SHOULD BE MUCH PRECIPITATION THAT OCCURS
ALONG/AHEAD OF THE COLD FRONT. THERMAL PROFILES OFF OF THE 01.00Z
GFS SUGGEST THAT THE PRECIPITATION SHOULD MAINLY FALL AS LIGHT
RAIN...BUT CAN NOT RULE OUT THAT THERE COULD BE SOME SNOW THAT
MIXES IN AS THE PROFILE SATURATES DOWN TO THE WET BULB TEMPERATURE.
THE FOCUS THEN GOES TO A MORE POTENT SYSTEM THAT WILL BE
DEVELOPING IN THE CENTRAL PLAINS ON FRIDAY WITH THE AFOREMENTIONED
COLD FRONT TRANSITIONING TO A WARM FRONT. THE INITIAL QUESTION
REMAINS WITH HOW FAR NORTH THAT FRONT MAKES IT NEXT WEEKEND AS
TEMPERATURES WILL LIKELY BE IN THE 60S TO THE SOUTH OF IT AND IN
THE 30S WITH SNOW TO THE NORTH OF IT. THE ECMWF HAS FLIP FLOPPED
AROUND A BIT THE PAST FEW DAYS WITH THE TRACK OF THE SURFACE LOW
THAT EVENTUALLY COMES THROUGH THE REGION ON SUNDAY WHILE THE GFS
HAS BEEN FAIRLY STEADY WITH ITS TRACK. A FEW OF THE ECMWF RUNS
HAVE TAKEN A MORE NORTHERLY TRACK THROUGH SOUTHERN
MINNESOTA/CENTRAL WISCONSIN WHILE THE GFS HAS BEEN FAIRLY
CONSISTENT WITH TAKING THE LOW THROUGH IOWA. PRECIPITATION WILL
INITIALLY START OUT WELL AHEAD OF THIS LOW AS WARM AIR
ADVECTION/FRONTOGENESIS STRENGTHENS ALONG THE THERMAL GRADIENT. A
LOT OF DETAILS TO BE WORKED OUT AND HAVE BASICALLY DONE A BLEND
BETWEEN THE 01.00Z GFS/ECMWF WITH THIS SYSTEM BUT SOME DRASTIC
CHANGES COULD BE IN STORE DEPENDING ON WHETHER WE END UP IN THE
WARM OR COLD SECTOR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
1148 PM CDT SUN MAR 31 2013
SURFACE HIGH PRESSURE WILL BUILD SOUTHEAST FROM THE NORTHERN
PLAINS INTO THE UPPER MISSISSIPPI RIVER VALLEY THROUGH THE TAF
PERIOD. NORTHWEST WINDS WILL CONTINUE INTO THE 10 TO 15 KNOT
RANGE THROUGH 00Z TUESDAY...THEN DIMINISH AS THE SURFACE HIGH
SPREADS EASTWARD INTO THE AREA. SOME PATCHES OF MVFR CLOUDS SEEN
ON SATELLITE ACROSS NORTHERN MINNESOTA. MODELS...ESPECIALLY THE
NAM AND RAP ARE BOTH OVERDOING THE CURRENT MOISTURE FIELD. DID
MENTION SCATTERED CLOUDS WITH BASES BETWEEN 020-030K FEET AFTER
11Z AT KRST AND 15Z AT KLSE. THIS WILL THEN DISSIPATE AFTER 00Z
TUESDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1148 PM CDT SUN MAR 31 2013
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
321 PM CDT SUN MAR 31 2013
AT 3 PM...A CANADIAN COLD FRONT EXTENDED FROM TRAVERSE CITY MICHIGAN
TO COLUMBIA MISSOURI. ANOTHER MUCH STRONGER CANADIAN COLD FRONT EXTENDED
FROM IRONWOOD MICHIGAN TO MANKATO MINNESOTA. SCATTERED RAIN AND
SNOW SHOWERS WERE DEVELOPING AHEAD OF THIS SECOND FRONT ACROSS
WESTERN WISCONSIN. WITH 925-800 MB LAPSE RATES RUNNING AROUND 8C/KM...
THE STRONGER WINDS FROM ALOFT ARE MIXING DOWN TO THE SURFACE. JUST
IN THE PAST HOUR...THE WINDS HAVE BEEN GUSTING INTO THE 30 TO
35 MPH RANGE ACROSS NORTHEAST IOWA AND SOUTHEAST MINNESOTA. THE
STRONGEST WIND GUST /36 MPH/ WAS A MAYO HELIPAD IN ROCHESTER
MINNESOTA. THESE WIND GUST WILL QUICKLY WANE EARLY THIS EVENING
WITH THE LOSS OF DIURNAL HEATING.
FOR LATE TONIGHT AND MONDAY...THE 31.12Z NAM/WRF SHOWS THAT SOME
OF THE CLOUDS ACROSS NORTHERN MINNESOTA...WESTERN ONTARIO...AND
EASTERN MANITOBA WILL MOVE SOUTHEAST TOWARD THE FORECAST AREA. IN
ADDITION WITH CONVECTIVE TEMPERATURE IN THE MID TO UPPER
20S...THIS WOULD ALSO FAVOR THE DEVELOPMENT OF A SCATTERED TO
BROKEN DECK OF CUMULUS CLOUDS. IN ADDITION...THE 31.12Z NMM WOULD
SUGGEST THE POSSIBILITY OF A FEW SNOW SHOWERS ACROSS TAYLOR COUNTY
AND THE NORTHERN PORTIONS OF CLARK COUNTY IN CENTRAL AND NORTH CENTRAL
WISCONSIN. SINCE THIS IS THE ONLY MODEL SHOWING THIS...KEPT THE
FORECAST DRY FOR NOW.
ON TUESDAY AFTERNOON...THE MODELS CONTINUE TO SHOW THAT ANOTHER
SHORT WAVE TROUGH MOVE THROUGH THE NORTHERN AND EASTERN PORTIONS
OF WISCONSIN. THE SOUNDINGS SHOW A SLIGHT SATURATION OCCURRING
BETWEEN 850 AND 700 MB. WITH THE 270-280K ISENTROPIC CONDENSATION
PRESSURE DEFICITS GREATER THAN 100 MB NOT EXPECTING VERY MANY
CLOUDS OR PRECIPITATION FROM THIS SYSTEM.
ON WEDNESDAY...THE MODELS CONTINUE TO SLOW THE EASTWARD
PROGRESSION OF A FRONT MOVING TOWARD THE AREA FROM THE NORTHERN
PLAINS. DUE TO THIS...THE PRESSURE GRADIENT IS NOT AS TIGHT AND
THE AREA DOES NOT MIX AS DEEP. AS RESULT...COOLED THE HIGH
TEMPERATURES A FEW DEGREES.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
321 PM CDT SUN MAR 31 2013
ON THURSDAY...A FRONT WILL MOVE THROUGH THE AREA. IT CONTINUES TO
LOOK LIKE THE BEST SYNOPTIC AND ISENTROPIC LIFT AND THE BEST 925
TO 850 MB MOISTURE TRANSPORT WILL BE MAINLY TO OUR NORTHWEST. THE
GFS CONTINUES TO SHOW THAT THIS FRONT WILL PRODUCE A BAND OF
PRECIPITATION AS IT PROGRESSES SOUTHEAST ACROSS THE AREA.
MEANWHILE THE GEM AND ECMWF SHOW THAT THIS PRECIPITATION WILL
DEVELOP NORTH OF INTERSTATE 94 DURING THE MORNING AND THEN MOVES
THROUGH THE REMAINDER OF THE AREA DRY DURING THE AFTERNOON.
OVERALL PREFER THE ECMWF AND GEM SOLUTIONS DUE TO THE LACK OF
MOISTURE TRANSPORT DURING THE AFTERNOON...AND THAT THE GFS HAS
BEEN HAVING A LOT OF ISSUES WITH ITS LOW LEVEL MOISTURE DURING THE
PAST MONTH.
FROM FRIDAY AFTERNOON THROUGH THE UPCOMING WEEKEND...THE MODELS
CONTINUE TO STRUGGLE WITH THEIR TIMING AND LOCATION OF A SERIES OF
LOW PRESSURE SYSTEMS MOVING THROUGH THE REGION. MUCH OF THIS IS
HOW THEY HAVE BEEN TRYING TO DEVELOP A TROUGH OVER THE WESTERN
UNITED STATES AND A RIDGE OVER THE CENTRAL UNITED STATES. OVER THE
PAST DAY...THE MODELS HAVE BEEN SLOWING THIS DEVELOPMENT AND THIS
HAS KEPT OUR AREA MORE IN ZONAL FLOW ALOFT. AS A RESULT...THE
TEMPERATURES HAVE BEEN COOLING OVER THE PAST 4 MODEL RUNS. AS A
RESULT...HAD TO INTRODUCE MORE SNOW INTO THE FORECAST FOR THIS
TIME PERIOD. WITH THE FIRST SYSTEM /FRIDAY AFTERNOON THROUGH
SATURDAY/...THE GFS IS PRODUCING A 6 TO 12 INCH BAND OF SNOW ALONG
AND NORTH OF INTERSTATE 94. MEANWHILE THE ECMWF HAS A 3 TO 6 INCH
BAND OF SNOW ACROSS FAR NORTHERN WISCONSIN AND UPPER MICHIGAN. THE
GFS THEN MOVES YET ANOTHER LOW PRESSURE SYSTEM INTO SOUTHEAST
MINNESOTA...NORTHEAST IOWA...AND SOUTHWEST WISCONSIN ON SATURDAY.
THE ECMWF ALSO SHOWS ANOTHER LOW PRESSURE SYSTEM...BUT IT DOES NOT
AFFECT THE AREA UNTIL MONDAY. THE TEMPERATURES ALOFT LOOK A BIT
WARMER...SO THE PRECIPITATION WITH THIS SYSTEM LOOKS TO BE IN THE
FORM OF RAIN.
&&
.AVIATION...THROUGH 06Z TUESDAY
1148 PM CDT SUN MAR 31 2013
SURFACE HIGH PRESSURE WILL BUILD SOUTHEAST FROM THE NORTHERN
PLAINS INTO THE UPPER MISSISSIPPI RIVER VALLEY THROUGH THE TAF
PERIOD. NORTHWEST WINDS WILL CONTINUE INTO THE 10 TO 15 KNOT
RANGE THROUGH 00Z TUESDAY...THEN DIMINISH AS THE SURFACE HIGH
SPREADS EASTWARD INTO THE AREA. SOME PATCHES OF MVFR CLOUDS SEEN
ON SATELLITE ACROSS NORTHERN MINNESOTA. MODELS...ESPECIALLY THE
NAM AND RAP ARE BOTH OVERDOING THE CURRENT MOISTURE FIELD. DID
MENTION SCATTERED CLOUDS WITH BASES BETWEEN 020-030K FEET AFTER
11Z AT KRST AND 15Z AT KLSE. THIS WILL THEN DISSIPATE AFTER 00Z TUESDAY.
&&
.HYDROLOGY...TODAY AND TONIGHT
1235 PM CDT SUN MAR 31 2013
MANY RIVERS HAVE CLIMBED OVER THE PAST FEW DAYS DUE TO RECENT SNOW
MELT AND THE RAIN THAT FELL ON SATURDAY WHICH GENERALLY TOTALED UP
TO BETWEEN A QUARTER AND THREE QUARTERS OF AN INCH. THERE HAVE
BEEN REPORTS OF SOME ROADS BEING CLOSED DUE TO HIGH WATER...
PARTICULARLY IN PORTIONS OF SOUTHEAST MINNESOTA WHERE THERE HAD
BEEN QUITE A BIT OF SNOW STILL ON THE GROUND LEADING UP TO THIS
WEEKEND. APPEARS THAT HIGH WATER LEVELS ARE PAST THEIR PEAKS OVER
NORTHEAST IA AND SOUTHWEST WI...AND ARE RIGHT AROUND THEIR PEAK
NOW FOR SOUTHEAST MN. WITH THE COOLER WEATHER MOVING IN...
ANTICIPATE THAT THE RUNOFF WILL SLOW AND CEASE...ALLOWING THIS
WATER TO MOVE OFF DOWNSTREAM.
WILL CONTINUE TO MONITOR THE RIVERS CLOSELY. REFER TO THE LATEST
STATEMENTS FOR UP-TO-DATE INFO.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
321 PM CDT SUN MAR 31 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...RABERDING
HYDROLOGY....MW
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
314 AM CDT WED APR 3 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 314 AM CDT WED APR 3 2013
THE RAP...NAM AND GFS ARE SUGGESTING SUFFICIENT LOW AND MID LEVEL
CLOUDINESS ACROSS SRN NEB TO HOLD TEMPS IN THE 50S TODAY. AT THE
SAME TIME SOUTH AND SOUTHWEST WINDS WILL RECIRCULATE COOL AIR NORTH
FROM THE HIGH PRESSURE SYSTEM ACROSS THE MID SOUTH. SO THE RAP 21Z
TEMPS WERE USED AS THE BASIS FOR TODAYS HIGHS WHICH IS CLOSE TO THE
GUIDANCE DATA SETS. IF FULL SUN ARRIVES OR EVEN JUST HIGH LEVEL
CLOUDINESS...HIGHS COULD BE A FEW DEGREES WARMER.
THE BEST GUESS ON TONIGHTS LOWS IS FOR THE CLOUDS TO DEPART WITH
WEAK SFC WINDS DEVELOPING AHEAD OF A COLD FRONT MOVING THROUGH SOUTH
DAKOTA WHICH WOULD SUPPORT SOME RADIATIONAL COOLING ACROSS NEB. LOWS
IN THE UPPER 20S TO MID 30S APPEARS TO BE THE BEST FORECAST.
ADDITIONAL COOLING FROM THE DROUGHT CONDITIONS COULD PUSH LOWS
FURTHER.
THE REST OF THE FCST IS WELL BEHAVED. WINDS COULD REACH THE BREEZY
CATEGORY BUT RELATIVE HUMIDITY WILL RUN 25 TO 30 PERCENT. THE RAP
SUGGESTED LOWER RH ACROSS FAR NORTHWEST NEB AS THE FRONT NOSES SOUTH
LATE THIS AFTN BUT AT THE SAME TIME WINDS WEAKEN.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 314 AM CDT WED APR 3 2013
12Z THURSDAY AND BEYOND. TWO MAIN CONCERNS GOING IN
THE EXTENDED PERIOD. FIRST BEING THE POTENTIAL FOR FIRE HEADLINES
ON FRIDAY...THEREAFTER THE FOCUS TURNS TO THE DEVELOPMENT OF A
WESTERN CONUS TROUGH...WHICH MAY BRING PERIODS OF WIDESPREAD
PRECIPITATION BACK ACROSS THE FORECAST AREA LATE THIS WEEKEND
THROUGH EARLY NEXT WEEK.
SURFACE TEMPERATURES WILL SLOWLY MODERATE FROM WEST TO EAST ON
THURSDAY AS SURFACE HIGH PRESSURE SLOWLY BUILDS EAST ACROSS THE
NORTHERN PLAINS AND ALLOWS FOR A RETURN SOUTHERLY FLOW. A TIGHT
GRADIENT IS EXPECTED IN THE TEMPERATURE FIELD...WITH HIGHS POSSIBLY
APPROACHING 70 ACROSS SOUTHWEST NEBRASKA...BUT READINGS OF ONLY THE
LOW TO MID 50S OVER NORTH CENTRAL NEBRASKA. FOR FRIDAY...THE
NORTHERN PLAINS HIGH WILL BE LOCATED OVER THE GREAT LAKES REGION
WITH STRONG SOUTHERLY RETURN FLOW TARGETING THE ENTIRE FORECAST
AREA. WITH DEEPENING LOW PRESSURE ON THE LEE OF THE ROCKIES...A
TIGHT PRESSURE GRADIENT IS EXPECTED...WITH THE POTENTIAL FOR WIND
GUSTS IN EXCESS OF 25 MPH. MEANWHILE SFC TEMPERATURE AND DEW POINT
SPREADS WILL APPROACH 40 F...WHICH SHOULD LEAD TO LOCALIZED AREAS OF
SUB 20 PERCENT RH. GIVEN THAT GREEN UP HAS NOT YET
OCCURRED...LOCALIZED RED FLAG CONDITIONS ARE POSSIBLE. UNCERTAINTY
REMAINS IF THE RED FLAG CRITERIA WIND GUSTS WILL BE CO-LOCATED
WITHIN THE CRITICAL RH FIELD. AT THIS TIME...IT APPEARS THAT THE
STRONGEST GUSTS SHOULD OCCUR OVER EASTERN PORTIONS OF THE
CWA...WHERE THE SOUTHERLY FLOW SHOULD HELP PUSH TD/S UP NEAR
40...WHICH WOULD KEEP MINIMUM RH IN THE 20-30 PERCENT RANGE. THE
DRIEST AIR IS EXPECTED ACROSS THE WESTERN HALF OF THE CWA...SLIGHTLY
REMOVED FROM THE STRONGEST GUSTS. OBVIOUSLY THERE IS STILL TIME TO
HAMMER OUT THE DETAILS...BUT GIVEN A FAVORABLE FIRE WX PATTERN
/RIDGE BREAKDOWN/ AND THE FACT THAT WIND SHIFT IS EXPECTED LATE
AFTERNOON/EVENING AS A SURFACE TROUGH AND COLD FRONT ADVANCE EAST
ACROSS THE CWA...ITS SAFE TO SAY AT THIS JUNCTURE THAT ELEVATED FIRE
CONCERNS ARE CERTAINLY WARRANTED...WILL CONTINUE TO MONITOR. ALSO
OF CONCERN...PROXIMITY SOUNDINGS INDICATE WEAK INSTABILITY ALONG THE
FRONTAL PASSAGE...BUT DRY LOWER LEVELS...A FEW DRIER CG STRIKES COULD
OCCUR. OTHERWISE HIGH TEMPERATURES WILL COOL SOME TEN DEGREES FROM
THE MID 70S DOWN TO THE UPPER 50S TO MID 60S ON SATURDAY. LOWS
FRIDAY AND SATURDAY MORNING WILL BE MILD RELATIVELY SPEAKING...WITH
LOWS IN THE 30S FRIDAY...AND LOWS IN THE 40S SATURDAY MORNING.
ATTENTION NOW TURNS TO THE MYRIAD OF POTENTIAL WEATHER FOR LATE
SUNDAY THROUGH EARLY NEXT WEEK...BUT UNFORTUNATELY THE 03.00Z RUN OF
THE MODELS FAILED TO INCREASE FORECAST CONFIDENCE AS SIGNIFICANT
DIFFERENCES IN TIMING AND STRENGTH OF THE WESTERN CONUS TROUGH
EXISTS. THE GENERAL IDEA IS THAT A SHORTWAVE WILL CROSS THE
CENTRAL/NORTHERN PLAINS ON SUNDAY PROVIDING FOR SHOWERS AND/OR
TSTMS...THEN THE MEAN TROUGH WILL DEVELOP OVER THE ROCKIES AND
SLOWLY ADVANCE OUT ONTO THE PLAINS EARLY NEXT WEEK. THE EC SOLUTION
CONTINUES TO ADVERTISE ENOUGH COLD AIR ON THE BACK SIDE OF THE MAIN
H5 LOW TO ALLOW FOR SNOW ACCUMULATIONS...WHICH MAY BE SIGNIFICANT.
ALSO OF NOTE...THE EC DEVELOPS H85 WINDS IN EXCESS OF 60KTS EARLY
TUESDAY ACROSS EASTERN PORTIONS OF THE CWA. THE EURO HAS SHOWN A
COLD BIAS WITH IT/S LAST STORM THAT AFFECTED OUR CWA...SO THE AMOUNT
OF COOLING IS SUSPECT. THE GFS IS SHOWING A BIT MORE OF A SOUTHERLY
TRACK OF THE MEAN TROUGH...AND IS LESS NEGATIVELY TILTED...BUT THE
GFS ENSEMBLE MEAN GIVES SUPPORT TO THE EC SOLUTION. AS STATED
PREVIOUSLY...CONFIDENCE IN ANY PARTICULAR SOLUTION IS LOW...THUS
WILL MAINTAIN 40 PERCENT POPS OR LESS THROUGH THE EVENT AND KEEP THE
GENERAL IDEA OF SHOWERS OF RAIN INITIALLY...THEN POSSIBLY CHANGING
OVER TO SNOW MONDAY NIGHT INTO TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1240 AM CDT WED APR 3 2013
SATELLITE IMAGERY IS SHOWING LOW CLOUDS WITH CEILINGS 1000-2000 FEET
AGL ACROSS EASTERN COLORADO AND 2000-3000 FEET IN NORTHWEST KANSAS
AND EXTREME SOUTHWEST NEBRASKA. A PROJECTION OF THE CURRENT MOVEMENT
KEEPS THE LOWER CLOUDS SOUTH OF AN OGA-LBF LINE. HOWEVER...LOW LEVEL
WIND WOULD INDICATE SOME PROGRESS FARTHER NORTH THAN THAT. IN
FACT...SHORT RANGE PROJECTIONS FROM THE EVENING MODEL RUN SHOW THE
LOWER CLOUDS SPREADING THROUGH OGA TO MHN BUT STILL WEST OF LBF AND
SOUTHWEST OF VTN. SO...FOR NOW...WE WILL KEEP LOW CEILINGS OUT OF
THE FORECASTS FOR LBF AND VTN.
WIND WILL BE BELOW 10KT UNTIL LATE MORNING...AROUND 15Z...WHEN IT
WILL INCREASE AGAIN AND BECOME 190-220 AT 16-20G24-28KT IN THE NORTH
AND 180-210 AT 12-14G18-24KT IN THE SOUTHWEST.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
410 AM CDT WED APR 3 2013
.SHORT TERM...
MAJOR CHANGE TO THE FCST THIS MORNING IS TO CONSIDERABLY LOWER POPS
ACROSS THE AREA. UNFORTUNATELY...PREVIOUS MODEL RUNS MISSED THE
EXTENSIVE MCS THAT MOVED ACROSS AREAS FROM NW TEXAS TO SOUTH TEXAS.
IT APPEARS THAT THIS MCS WILL LEAVE THE FCST AREA STARVED OF DEEP
MOISTURE AND THUS THE LIFT ASSOCIATED WITH THE LOW OVER CNTL
COLORADO WILL LIKELY PRODUCE MUCH LESS PRECIP THAN PREVIOUSLY
EXPECTED. THE 00Z MODEL SUITE MISSED THIS CRITICAL ELEMENT RESULTING
IN TOO MUCH WIDESPREAD QPF AND MOS GUIDANCE WHOSE POPS APPEAR TO BE
TOO HIGH. HAVE TRENDED THE FCST MUCH CLOSER TO THE 06Z RUC WHICH DID
INITIALIZE THE MCS AND SUBSEQUENTLY SEEMS TO HAVE A BETTER HANDLE ON
POSSIBLE PRECIP TODAY. THAT POSSIBILITY THEN SEEMS TO FOCUS ON
POTENTIAL FOR SCATTERED LIGHT SHOWERS MAINLY ACROSS THE NRN ZONES IN
AN AREA OF LIFT JUST AHEAD AND SOUTH OF THE TRACK OF THE UPPER LOW.
PRECIP HAS BEEN HARD TO COME BY VCNTY OF THE LOW WITH SOME LIGHT RA
AND SN IN SRN COLORADO AND SOME LIGHT RA SOUTH OF KABQ IN CNTL NM AS
A JET STREAK ROTATES AROUND THE BASE OF THE TROUGH.
IN THE NEAR TERM EVEN DRIZZLE CHANCES APPEAR TO BE ON THE WANE AS A
MID LEVEL DRY SLOT AND SOME APPARENT DOWNWARD MOTION TO THE REAR OF
THE CNTL TX MCS WORK IN ACROSS THE AREA. COULD SEE DRIZZLE TRY TO
REDEVELOP A LITTLE LATER THIS MORNING ONCE SOME WEAK LIFT WORKS BACK
OVER THE AREA...BUT EVEN MEASURABLE PRECIP FROM THIS ELEMENT LOOKING
VERY UNLIKELY.
TEMP FCST WILL BE TRICKY FOR THIS AFTN WITH SOME UNCERTAINTY
REGARDING HOW MUCH LOW STRATUS WILL REMAIN IN PLACE OR THIN. 00Z
MODELS APPEAR TO BE TOO AGGRESSIVE WITH WARMING AND HAVE TRENDED
TEMPS A BIT BELOW MOS. HOWEVER...ANY LATE DAY CLEARING OR LIFTING OF
CEILINGS AS THE CENTER OF THE LOW MOVES ACROSS THE SRN PANHANDLE
WOULD SEE TEMPS APPROACH THAT PROGGED BY MOS. THIS WOULD BE MOST
LIKELY TO OCCUR ACROSS THE SWRN ZONES.
MOVING INTO TONIGHT...LESSENING RAIN CHANCES SHOULD SHIFT EAST OF
THE AREA BY EARLY EVENING. MODELS KEEP LOW LEVEL MOISTURE LEVELS
PRETTY STEADY WHILE DROPPING WINDS OFF TO BECOME VERY LIGHT. SOME
HINTING OF FOG POTENTIAL LATE TONIGHT...AND IF MORE RAIN HAD FALLEN
IN THE LAST 24 HOURS OR MORE FALLS THAN EXPECTED OVER THE NEXT
SEVERAL HOURS WOULD BE MORE INCLINED TO MENTION AREAS OF FOG IN THE
FCST. STILL A BIT TOO MUCH UNCERTAINTY HERE AND WILL LET NEXT SHIFT
REEVALUATE THAT POTENTIAL.
&&
.LONG TERM...
A RETURN TO MORE SEASONABLE TEMPS REMAINS ON TRACK BEGINNING
TOMORROW AS THE SOUTH PLAINS SHAKES THE RECENT FORAY OF MODIFIED
CANADIAN AIR. A BEVERAGE SUCH AS CANADA DRY WOULD PROVE FITTING
FOR THE NEXT SEVERAL DAYS AS TRANSIENT RIDGING ALOFT CARRIES A
DOME OF VERY MILD AND DRY AIR EAST OVER MUCH OF THE SOUTH PLAINS.
BY FRIDAY...WE SHOULD SEE A PALTRY DRYLINE EVOLVE IN THE ROLLING
PLAINS BEHIND THE DEPARTING SURFACE HIGH. QUALITY RETURN FLOW
HOWEVER IS NOT EXPECTED UNTIL SATURDAY AT WHICH POINT STRONGER
WESTERLY WINDS ALOFT BEHIND THE UPPER RIDGE WILL SHUNT MUCH OF
THIS SHALLOW MOISTURE OUT OF ALL BUT OUR FAR EASTERN COLUMN OF
COUNTIES. A MINOR SHORT WAVE TROUGH IS STILL PROGGED TO SLIDE
THROUGH THIS STRONGER WESTERLY FLOW BY SAT NIGHT/SUN MORNING
ACCOMPANIED BY PERHAPS EVEN DRIER AND WARMER CONDITIONS ON
SUNDAY...BUT WILL STICK WITH SLIGHTLY COOLER CONDITIONS AS A
COLD FRONT WILL BE FOUND EDGING PERILOUSLY CLOSE TO OUR NRN
COUNTIES IN THE WAKE OF THIS UPPER IMPULSE.
BY EARLY NEXT WEEK...NO CHANGES ARE WARRANTED ATTM AS MODELS ARE
NOW IN MORE DISAGREEMENT THAN 24 HOURS AGO. WPC CONTINUES TO FAVOR
A SLOWER AND DEEPER LONGWAVE TROUGH EVOLVING IN THE GREAT BASIN
AND FOUR CORNERS REGION BY THIS TIME. ONLY SIMILARITY AMONG THE
CURRENT ECMWF AND GFS IS THAT THIS WAVE WOULD BE OPEN AND
PROGRESSIVE...THOUGH SIGNIFICANT DIFFERENCES EMERGE IN THE TIMING
OF SAID WAVE AND HOW MUCH CP AIR IS DRAWN SOUTHWARD FOLLOWING ITS
PASSAGE. WOULD STILL EXPECT A SEMI-ACTIVE DRYLINE TO UNFOLD NEAR
THE FRINGES OF OUR EASTERN COUNTIES AS EARLY AS MON AND PERHAPS
LINGERING INTO TUE UNDERNEATH AN INCREASINGLY UNSETTLED SWLY UPPER
FLOW REGIME. THE GEFS MEAN AND EVEN THE CMC INDICATE SUCH A
SCENARIO THAT AS OF YESTERDAY WAS FAVORED BY THE ECMWF...BUT WILL
AWAIT LATER MODEL RUNS BEFORE COMMITTING TO ANY CHANGES STILL SO
MANY PERIODS OUT.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 46 32 68 43 76 / 40 10 0 0 0
TULIA 41 32 67 43 77 / 40 10 0 0 0
PLAINVIEW 41 34 68 44 77 / 30 10 0 0 0
LEVELLAND 48 34 70 46 81 / 30 10 0 0 0
LUBBOCK 43 35 70 45 79 / 30 10 0 0 0
DENVER CITY 51 34 70 47 82 / 20 10 0 0 0
BROWNFIELD 48 35 70 46 82 / 30 10 0 0 0
CHILDRESS 43 35 64 43 78 / 40 20 0 0 0
SPUR 41 35 68 45 81 / 30 10 0 0 0
ASPERMONT 43 37 66 44 80 / 30 10 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07/93
AREA FORECAST DISCUSSION
NWS PUEBLO CO
700 AM MDT WED APR 3 2013
.UPDATE...
ISSUED AT 655 AM MDT WED APR 3 2013
UPDATED FORECAST TO REFLECT CURRENT CONDITIONS. REMOVED
DRIZZLE/FOG FROM SOUTHERN I-25 CORRIDOR AS VISIBILITY HAS BEEN
IMPROVING MOST AREAS. STILL SOME DENSE FOG AND PATCHY FREEZING
DRIZZLE ACROSS EL PASO COUNTY THROUGH MID-MRNG AS WINDS HAVE YET
TO GO NORTHERLY. ALSO ADDED A COUPLE HOURS OF LIGHT SNOW TO SAN
LUIS VALLEY...WHERE ALAMOSA HAS BEEN REPORTING SNOW THE PAST HOUR.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM MDT WED APR 3 2013
UPPER LOW GRADUALLY SLIPPING EASTWARD ACROSS THE STATE EARLY THIS
MORNING...AND SHOULD MOVE INTO THE SOUTHERN PLAINS BY THIS
EVENING. STILL SOME RESIDUAL -SHRA/-SHSN/-FZDZ ACROSS THE AREA
THIS MORNING...THOUGH RADAR TRENDS SUGGEST GRADUALLY DECREASING
COVERAGE AND INTENSITY SINCE 09Z. WILL HOLD ON TO SOME LIGHT
PRECIP THROUGH THE MORNING MOST AREAS...GRADUALLY ENDING FROM NW
TO SE BY MIDDAY. MAY SEE A FEW SHOWERS REFIRE OVER THE MTS THIS
AFTERNOON AS LAPSE RATES REMAIN FAIRLY STEEP...THOUGH PRECIP WILL
BE VERY LIGHT. PERSISTENT -FZDZ AND FZFG OVER EL PASO COUNTY MAY
LINGER THROUGH LATE MORNING...AS LATEST HRRR KEEPS WEAK SOUTHEAST
WIND IN PLACE UNTIL 17Z. STILL THINK N-NW FLOW WILL DEVELOP THIS
AFTERNOON AND GRADUALLY REMOVE ANY REMNANTS OF CLOUDS/FOG...THOUGH
FAR SOUTHEAST PLAINS MAY HAVE TO WAIT UNTIL VERY LATE AFTERNOON TO
SEE ANY SUN. WILL CONTINUE WITH REASONABLY MILD MAX TEMPS MOST
LOCATIONS...THOUGH KEPT AREAS AROUND SPRINGFIELD COLDER THAN
GUIDANCE DUE TO LINGERING CLOUDS. OVERNIGHT...WILL END PRECIP
QUICKLY IN THE EVENING WITH LOSS OF HEATING...LEADING TO A MOSTLY
CLEAR AND SEASONABLY COOL NIGHT MOST AREAS UNDER WEAK NORTHWEST
FLOW.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 352 AM MDT WED APR 3 2013
...SIGNIFICANT STORM POSSIBLE EARLY NEXT WEEK...
LATTER HALF OF THIS WEEK LOOKS QUITE PLEASANT AS A TRANSITORY RIDGE
CROSSES OUR AREA. THURSDAY MAY BE THE NICEST DAY...WITH DRY AND CLEAR
CONDITIONS EXPECTED AREA-WIDE. WINDS SHOULD BE RELATIVELY LIGHT WITH
THE RIDGE AXIS JUST WWD OF THE CWA. GIVEN THE LIGHT WINDS AND H7
TEMPS AROUND 4 DEGREES OR SO...HAVE GONE ON THE LOW SIDE OF MOS FOR
TEMPS ON THE PLAINS...WITH HIGHS EXPECTED TO BE IN THE UPPER 60S TO
AROUND 70 DEGREES.
FRIDAY...FIRE WX ISSUES ARISE AS THE RIDGE SHIFTS TO THE EAST...AND
ZONAL FLOW STRENGTHENS ACROSS THE CONTDVD. SHOULD SEE MARGINALLY
CRITICAL FIRE WX CONDITIONS DEVELOP ACROSS THE PLAINS AS RH DROPS TO
BELOW 15 PERCENT AND W WINDS BECOME RATHER GUSTY BY AFTERNOON.
FOR THE WEEKEND...A WEAK SHORTWAVE TROUGH WILL MOVE THROUGH THE NRN
ROCKIES...AND WILL LIKELY SPARK SCT-NMRS SHOWERS ACROSS THE MTS
ESPECIALLY SAT AFTERNOON-EVE. MAIN CHANCES FOR PRECIP WILL BE N OF
HIGHWAY 50 BOTH DAYS. TEMPS SHOULD REMAIN QUITE PLEASANT...IN THE MID
60S ACROSS THE PLAINS AND 50S FOR THE MTS AND HIGH VALLEYS.
MAIN FOCUS IN THE EXTENDED CONTINUES TO BE THE LARGE SPRING STORM
SYSTEM THAT IS EXPECTED TO AFFECT OUR AREA BY LATE IN THE WEEKEND
THROUGH THE FIRST HALF OF NEXT WEEK. ENSEMBLE MEANS CONTINUE TO SHOW
A DEEP TROUGH MOVING THROUGH THE SRN ROCKIES FROM MON THROUGH
WEDNESDAY. OP RUNS OF THE GFS AND ECMWF ALSO CONTINUE TO SHOW A DEEP
TROUGH MOVING THROUGH THE SOUTHERN ROCKIES DURING THIS TIME FRAME.
HOWEVER...SIGNIFICANT DIFFERENCES REMAIN IN THE EVOLUTION OF THE
TROUGH PER THE GFS AND EC. THE 00Z EC IS MORE PROGRESSIVE...BUT
SPLITS THE TROUGH...WITH THE MAIN ENERGY ARRIVING SUNDAY NIGHT THRU
MONDAY...AND A SECONDARY LOW MOVING THROUGH NEXT WED. THE GFS BRINGS
THE LOW THROUGH IN ONE PIECE...BUT IS SLOWER AND TARGETS THE MON
NIGHT-TUESDAY TIME FRAME FOR THE HIGHEST POPS. BOTH MODELS PROG
SIGNIFICANT QPF FOR SE CO...BETWEEN 1-2 INCHES OF LIQUID FOR THE
SUN-WED TIME PERIOD. BOTH MODELS ALSO TARGET THE SERN MTS FOR THE
HIGHEST PRECIP POTENTIAL. WHILE SNOW LEVELS LOOK TO REMAIN FAIRLY
HIGH FOR THE BULK OF THIS EVENT...THE SE MTS ABOVE 7000 FEET WOULD
PICK UP SIGNIFICANT SNOWFALL IN EITHER SCENARIO. THE ECMWF BRINGS IN
UNUSUALLY COLD AIR BEHIND THE TROUGH BY WED...WITH H7 TEMPS
BOTTOMING OUT NEAR MINUS 16 DEGREES. IF THIS OCCURS...THE HIGH TEMPS
FOR NEXT WED MAY NEED TO BE SUBSTANTIALLY REDUCED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 352 AM MDT WED APR 3 2013
AT KCOS...PERSISTENT SE SURFACE WIND HAS PRODUCED DENSE FZFG AND
FZDZ EARLY THIS MORNING...AND EXPECT LIFR CONDITIONS TO PERSIST
UNTIL 14Z...THEN IFR FROM 14-17Z AS FOG/CIGS BEGIN TO LIFT. PRECIP
AMOUNTS AND ANY ICING THIS MORNING SHOULD BE MINIMAL. WILL SEE VFR
CONDITIONS RETURN 17Z-18Z AS LIGHT NORTH WIND DEVELOP...THEN VFR
CONDITIONS FOR THE REMAINDER OF TODAY AND TONIGHT WITH LIGHT
WINDS. MAY SEE A -SHRA OVER THE MOUNTAINS WEST OF THE AIRPORT
AFTER 18Z...THOUGH CHANCE OF ANY SHOWERS AT THE TERMINAL LOOKS TOO
LOW TO MENTION IN THE TAF.
AT KPUB...E-SE WIND WILL KEEP IFR STRATUS IN PLACE UNTIL
14-15Z...THEN GRADUAL CLEARING BY 17Z AS WINDS BECOME LIGHT N.
EXPECT VFR CONDITIONS FROM 17Z ONWARD THROUGH THE AFTERNOON AND
OVERNIGHT WITH LIGHT WINDS.
AT KALS...SOME PATCHY MVFR STRATUS EARLY THIS MORNING WILL
DISSIPATE BY 14Z...THEN VFR CONDITIONS FOR THE REMAINDER OF TODAY
AND TONIGHT WITH LIGHT WINDS. MAY SEE A -SHRA OVER THE MOUNTAINS
SURROUNDING THE AREA AFTER 18Z...THOUGH IT APPEARS DOUBTFUL ANY
WILL MOVE TOWARD THE TERMINAL.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...PETERSEN
SHORT TERM...PETERSEN
LONG TERM...ROSE
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
428 AM MDT WED APR 3 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM MDT WED APR 3 2013
UPPER LOW GRADUALLY SLIPPING EASTWARD ACROSS THE STATE EARLY THIS
MORNING...AND SHOULD MOVE INTO THE SOUTHERN PLAINS BY THIS
EVENING. STILL SOME RESIDUAL -SHRA/-SHSN/-FZDZ ACROSS THE AREA
THIS MORNING...THOUGH RADAR TRENDS SUGGEST GRADUALLY DECREASING
COVERAGE AND INTENSITY SINCE 09Z. WILL HOLD ON TO SOME LIGHT
PRECIP THROUGH THE MORNING MOST AREAS...GRADUALLY ENDING FROM NW
TO SE BY MIDDAY. MAY SEE A FEW SHOWERS REFIRE OVER THE MTS THIS
AFTERNOON AS LAPSE RATES REMAIN FAIRLY STEEP...THOUGH PRECIP WILL
BE VERY LIGHT. PERSISTENT -FZDZ AND FZFG OVER EL PASO COUNTY MAY
LINGER THROUGH LATE MORNING...AS LATEST HRRR KEEPS WEAK SOUTHEAST
WIND IN PLACE UNTIL 17Z. STILL THINK N-NW FLOW WILL DEVELOP THIS
AFTERNOON AND GRADUALLY REMOVE ANY REMNANTS OF CLOUDS/FOG...THOUGH
FAR SOUTHEAST PLAINS MAY HAVE TO WAIT UNTIL VERY LATE AFTERNOON TO
SEE ANY SUN. WILL CONTINUE WITH REASONABLY MILD MAX TEMPS MOST
LOCATIONS...THOUGH KEPT AREAS AROUND SPRINGFIELD COLDER THAN
GUIDANCE DUE TO LINGERING CLOUDS. OVERNIGHT...WILL END PRECIP
QUICKLY IN THE EVENING WITH LOSS OF HEATING...LEADING TO A MOSTLY
CLEAR AND SEASONABLY COOL NIGHT MOST AREAS UNDER WEAK NORTHWEST
FLOW.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 352 AM MDT WED APR 3 2013
...SIGNIFICANT STORM POSSIBLE EARLY NEXT WEEK...
LATTER HALF OF THIS WEEK LOOKS QUITE PLEASANT AS A TRANSITORY RIDGE
CROSSES OUR AREA. THURSDAY MAY BE THE NICEST DAY...WITH DRY AND CLEAR
CONDITIONS EXPECTED AREA-WIDE. WINDS SHOULD BE RELATIVELY LIGHT WITH
THE RIDGE AXIS JUST WWD OF THE CWA. GIVEN THE LIGHT WINDS AND H7
TEMPS AROUND 4 DEGREES OR SO...HAVE GONE ON THE LOW SIDE OF MOS FOR
TEMPS ON THE PLAINS...WITH HIGHS EXPECTED TO BE IN THE UPPER 60S TO
AROUND 70 DEGREES.
FRIDAY...FIRE WX ISSUES ARISE AS THE RIDGE SHIFTS TO THE EAST...AND
ZONAL FLOW STRENGTHENS ACROSS THE CONTDVD. SHOULD SEE MARGINALLY
CRITICAL FIRE WX CONDITIONS DEVELOP ACROSS THE PLAINS AS RH DROPS TO
BELOW 15 PERCENT AND W WINDS BECOME RATHER GUSTY BY AFTERNOON.
FOR THE WEEKEND...A WEAK SHORTWAVE TROUGH WILL MOVE THROUGH THE NRN
ROCKIES...AND WILL LIKELY SPARK SCT-NMRS SHOWERS ACROSS THE MTS
ESPECIALLY SAT AFTERNOON-EVE. MAIN CHANCES FOR PRECIP WILL BE N OF
HIGHWAY 50 BOTH DAYS. TEMPS SHOULD REMAIN QUITE PLEASANT...IN THE MID
60S ACROSS THE PLAINS AND 50S FOR THE MTS AND HIGH VALLEYS.
MAIN FOCUS IN THE EXTENDED CONTINUES TO BE THE LARGE SPRING STORM
SYSTEM THAT IS EXPECTED TO AFFECT OUR AREA BY LATE IN THE WEEKEND
THROUGH THE FIRST HALF OF NEXT WEEK. ENSEMBLE MEANS CONTINUE TO SHOW
A DEEP TROUGH MOVING THROUGH THE SRN ROCKIES FROM MON THROUGH
WEDNESDAY. OP RUNS OF THE GFS AND ECMWF ALSO CONTINUE TO SHOW A DEEP
TROUGH MOVING THROUGH THE SOUTHERN ROCKIES DURING THIS TIME FRAME.
HOWEVER...SIGNIFICANT DIFFERENCES REMAIN IN THE EVOLUTION OF THE
TROUGH PER THE GFS AND EC. THE 00Z EC IS MORE PROGRESSIVE...BUT
SPLITS THE TROUGH...WITH THE MAIN ENERGY ARRIVING SUNDAY NIGHT THRU
MONDAY...AND A SECONDARY LOW MOVING THROUGH NEXT WED. THE GFS BRINGS
THE LOW THROUGH IN ONE PIECE...BUT IS SLOWER AND TARGETS THE MON
NIGHT-TUESDAY TIME FRAME FOR THE HIGHEST POPS. BOTH MODELS PROG
SIGNIFICANT QPF FOR SE CO...BETWEEN 1-2 INCHES OF LIQUID FOR THE
SUN-WED TIME PERIOD. BOTH MODELS ALSO TARGET THE SERN MTS FOR THE
HIGHEST PRECIP POTENTIAL. WHILE SNOW LEVELS LOOK TO REMAIN FAIRLY
HIGH FOR THE BULK OF THIS EVENT...THE SE MTS ABOVE 7000 FEET WOULD
PICK UP SIGNIFICANT SNOWFALL IN EITHER SCENARIO. THE ECMWF BRINGS IN
UNUSUALLY COLD AIR BEHIND THE TROUGH BY WED...WITH H7 TEMPS
BOTTOMING OUT NEAR MINUS 16 DEGREES. IF THIS OCCURS...THE HIGH TEMPS
FOR NEXT WED MAY NEED TO BE SUBSTANTIALLY REDUCED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 352 AM MDT WED APR 3 2013
AT KCOS...PERSISTENT SE SURFACE WIND HAS PRODUCED DENSE FZFG AND
FZDZ EARLY THIS MORNING...AND EXPECT LIFR CONDITIONS TO PERSIST
UNTIL 14Z...THEN IFR FROM 14-17Z AS FOG/CIGS BEGIN TO LIFT. PRECIP
AMOUNTS AND ANY ICING THIS MORNING SHOULD BE MINIMAL. WILL SEE VFR
CONDITIONS RETURN 17Z-18Z AS LIGHT NORTH WIND DEVELOP...THEN VFR
CONDITIONS FOR THE REMAINDER OF TODAY AND TONIGHT WITH LIGHT
WINDS. MAY SEE A -SHRA OVER THE MOUNTAINS WEST OF THE AIRPORT
AFTER 18Z...THOUGH CHANCE OF ANY SHOWERS AT THE TERMINAL LOOKS TOO
LOW TO MENTION IN THE TAF.
AT KPUB...E-SE WIND WILL KEEP IFR STRATUS IN PLACE UNTIL
14-15Z...THEN GRADUAL CLEARING BY 17Z AS WINDS BECOME LIGHT N.
EXPECT VFR CONDITIONS FROM 17Z ONWARD THROUGH THE AFTERNOON AND
OVERNIGHT WITH LIGHT WINDS.
AT KALS...SOME PATCHY MVFR STRATUS EARLY THIS MORNING WILL
DISSIPATE BY 14Z...THEN VFR CONDITIONS FOR THE REMAINDER OF TODAY
AND TONIGHT WITH LIGHT WINDS. MAY SEE A -SHRA OVER THE MOUNTAINS
SURROUNDING THE AREA AFTER 18Z...THOUGH IT APPEARS DOUBTFUL ANY
WILL MOVE TOWARD THE TERMINAL.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...ROSE
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
622 AM CDT WED APR 3 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 314 AM CDT WED APR 3 2013
THE RAP...NAM AND GFS ARE SUGGESTING SUFFICIENT LOW AND MID LEVEL
CLOUDINESS ACROSS SRN NEB TO HOLD TEMPS IN THE 50S TODAY. AT THE
SAME TIME SOUTH AND SOUTHWEST WINDS WILL RECIRCULATE COOL AIR NORTH
FROM THE HIGH PRESSURE SYSTEM ACROSS THE MID SOUTH. SO THE RAP 21Z
TEMPS WERE USED AS THE BASIS FOR TODAYS HIGHS WHICH IS CLOSE TO THE
GUIDANCE DATA SETS. IF FULL SUN ARRIVES OR EVEN JUST HIGH LEVEL
CLOUDINESS...HIGHS COULD BE A FEW DEGREES WARMER.
THE BEST GUESS ON TONIGHTS LOWS IS FOR THE CLOUDS TO DEPART WITH
WEAK SFC WINDS DEVELOPING AHEAD OF A COLD FRONT MOVING THROUGH SOUTH
DAKOTA WHICH WOULD SUPPORT SOME RADIATIONAL COOLING ACROSS NEB. LOWS
IN THE UPPER 20S TO MID 30S APPEARS TO BE THE BEST FORECAST.
ADDITIONAL COOLING FROM THE DROUGHT CONDITIONS COULD PUSH LOWS
FURTHER.
THE REST OF THE FCST IS WELL BEHAVED. WINDS COULD REACH THE BREEZY
CATEGORY BUT RELATIVE HUMIDITY WILL RUN 25 TO 30 PERCENT. THE RAP
SUGGESTED LOWER RH ACROSS FAR NORTHWEST NEB AS THE FRONT NOSES SOUTH
LATE THIS AFTN BUT AT THE SAME TIME WINDS WEAKEN.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 314 AM CDT WED APR 3 2013
12Z THURSDAY AND BEYOND. TWO MAIN CONCERNS GOING IN
THE EXTENDED PERIOD. FIRST BEING THE POTENTIAL FOR FIRE HEADLINES
ON FRIDAY...THEREAFTER THE FOCUS TURNS TO THE DEVELOPMENT OF A
WESTERN CONUS TROUGH...WHICH MAY BRING PERIODS OF WIDESPREAD
PRECIPITATION BACK ACROSS THE FORECAST AREA LATE THIS WEEKEND
THROUGH EARLY NEXT WEEK.
SURFACE TEMPERATURES WILL SLOWLY MODERATE FROM WEST TO EAST ON
THURSDAY AS SURFACE HIGH PRESSURE SLOWLY BUILDS EAST ACROSS THE
NORTHERN PLAINS AND ALLOWS FOR A RETURN SOUTHERLY FLOW. A TIGHT
GRADIENT IS EXPECTED IN THE TEMPERATURE FIELD...WITH HIGHS POSSIBLY
APPROACHING 70 ACROSS SOUTHWEST NEBRASKA...BUT READINGS OF ONLY THE
LOW TO MID 50S OVER NORTH CENTRAL NEBRASKA. FOR FRIDAY...THE
NORTHERN PLAINS HIGH WILL BE LOCATED OVER THE GREAT LAKES REGION
WITH STRONG SOUTHERLY RETURN FLOW TARGETING THE ENTIRE FORECAST
AREA. WITH DEEPENING LOW PRESSURE ON THE LEE OF THE ROCKIES...A
TIGHT PRESSURE GRADIENT IS EXPECTED...WITH THE POTENTIAL FOR WIND
GUSTS IN EXCESS OF 25 MPH. MEANWHILE SFC TEMPERATURE AND DEW POINT
SPREADS WILL APPROACH 40 F...WHICH SHOULD LEAD TO LOCALIZED AREAS OF
SUB 20 PERCENT RH. GIVEN THAT GREEN UP HAS NOT YET
OCCURRED...LOCALIZED RED FLAG CONDITIONS ARE POSSIBLE. UNCERTAINTY
REMAINS IF THE RED FLAG CRITERIA WIND GUSTS WILL BE CO-LOCATED
WITHIN THE CRITICAL RH FIELD. AT THIS TIME...IT APPEARS THAT THE
STRONGEST GUSTS SHOULD OCCUR OVER EASTERN PORTIONS OF THE
CWA...WHERE THE SOUTHERLY FLOW SHOULD HELP PUSH TD/S UP NEAR
40...WHICH WOULD KEEP MINIMUM RH IN THE 20-30 PERCENT RANGE. THE
DRIEST AIR IS EXPECTED ACROSS THE WESTERN HALF OF THE CWA...SLIGHTLY
REMOVED FROM THE STRONGEST GUSTS. OBVIOUSLY THERE IS STILL TIME TO
HAMMER OUT THE DETAILS...BUT GIVEN A FAVORABLE FIRE WX PATTERN
/RIDGE BREAKDOWN/ AND THE FACT THAT WIND SHIFT IS EXPECTED LATE
AFTERNOON/EVENING AS A SURFACE TROUGH AND COLD FRONT ADVANCE EAST
ACROSS THE CWA...ITS SAFE TO SAY AT THIS JUNCTURE THAT ELEVATED FIRE
CONCERNS ARE CERTAINLY WARRANTED...WILL CONTINUE TO MONITOR. ALSO
OF CONCERN...PROXIMITY SOUNDINGS INDICATE WEAK INSTABILITY ALONG THE
FRONTAL PASSAGE...BUT DRY LOWER LEVELS...A FEW DRIER CG STRIKES COULD
OCCUR. OTHERWISE HIGH TEMPERATURES WILL COOL SOME TEN DEGREES FROM
THE MID 70S DOWN TO THE UPPER 50S TO MID 60S ON SATURDAY. LOWS
FRIDAY AND SATURDAY MORNING WILL BE MILD RELATIVELY SPEAKING...WITH
LOWS IN THE 30S FRIDAY...AND LOWS IN THE 40S SATURDAY MORNING.
ATTENTION NOW TURNS TO THE MYRIAD OF POTENTIAL WEATHER FOR LATE
SUNDAY THROUGH EARLY NEXT WEEK...BUT UNFORTUNATELY THE 03.00Z RUN OF
THE MODELS FAILED TO INCREASE FORECAST CONFIDENCE AS SIGNIFICANT
DIFFERENCES IN TIMING AND STRENGTH OF THE WESTERN CONUS TROUGH
EXISTS. THE GENERAL IDEA IS THAT A SHORTWAVE WILL CROSS THE
CENTRAL/NORTHERN PLAINS ON SUNDAY PROVIDING FOR SHOWERS AND/OR
TSTMS...THEN THE MEAN TROUGH WILL DEVELOP OVER THE ROCKIES AND
SLOWLY ADVANCE OUT ONTO THE PLAINS EARLY NEXT WEEK. THE EC SOLUTION
CONTINUES TO ADVERTISE ENOUGH COLD AIR ON THE BACK SIDE OF THE MAIN
H5 LOW TO ALLOW FOR SNOW ACCUMULATIONS...WHICH MAY BE SIGNIFICANT.
ALSO OF NOTE...THE EC DEVELOPS H85 WINDS IN EXCESS OF 60KTS EARLY
TUESDAY ACROSS EASTERN PORTIONS OF THE CWA. THE EURO HAS SHOWN A
COLD BIAS WITH IT/S LAST STORM THAT AFFECTED OUR CWA...SO THE AMOUNT
OF COOLING IS SUSPECT. THE GFS IS SHOWING A BIT MORE OF A SOUTHERLY
TRACK OF THE MEAN TROUGH...AND IS LESS NEGATIVELY TILTED...BUT THE
GFS ENSEMBLE MEAN GIVES SUPPORT TO THE EC SOLUTION. AS STATED
PREVIOUSLY...CONFIDENCE IN ANY PARTICULAR SOLUTION IS LOW...THUS
WILL MAINTAIN 40 PERCENT POPS OR LESS THROUGH THE EVENT AND KEEP THE
GENERAL IDEA OF SHOWERS OF RAIN INITIALLY...THEN POSSIBLY CHANGING
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 630 AM CDT WED APR 3 2013
VFR IS GENERALLY EXPECTED ACROSS ALL AREAS TODAY AND TONIGHT.
LOCAL MVFR/IFR CIGS ARE MOVING NORTH THROUGH THE NEB PANHANDLE
SOUTH OF KAIA. THIS SHOULD MOVE NORTH TO NEAR KAIA THIS MORNING
AND THEN MIX OUT. A NARROW BAND OF MVFR CIGS COULD DEVELOP AOA 06Z TONIGHT
ALONG HIGHWAY 20 AS A COLD FRONT DROPS INTO NRN NEB. OTHERWISE VFR
SHOULD PREVAIL.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
634 AM CDT WED APR 3 2013
.AVIATION...
IFR CONDITIONS LIKELY TO PERSIST INTO THE AFTN HOURS AT BOTH TAF
SITES. KLBB MAY SEE SOME LIFTING OF THE CIGS THIS AFTN THEN
PROBABLY SCATTER OUT THIS EVENING. KCDS LOOKS LESS LIKELY TO SEE
MUCH IMPROVEMENT UNTIL LATE IN THE TAF PERIOD OR BEYOND.
DEEP MOISTURE NOT AS RICH AS EXPECTED WHICH WILL RESULT IN GREATLY
REDUCED PRECIP CHANCES TODAY. BOTH TAF SITES...KCDS MORESO THAN
KLBB...COULD SEE SOME LIGHT SHOWERS BUT CHANCES NOW LOOK TO SLIM
TO MENTION GIVEN RESTRICTIONS ON PROB30 GROUP WITHIN FIRST 9
HOURS OF TAF PERIOD.
&&
.PREV DISCUSSION... /ISSUED 410 AM CDT WED APR 3 2013/
SHORT TERM...
MAJOR CHANGE TO THE FCST THIS MORNING IS TO CONSIDERABLY LOWER POPS
ACROSS THE AREA. UNFORTUNATELY...PREVIOUS MODEL RUNS MISSED THE
EXTENSIVE MCS THAT MOVED ACROSS AREAS FROM NW TEXAS TO SOUTH TEXAS.
IT APPEARS THAT THIS MCS WILL LEAVE THE FCST AREA STARVED OF DEEP
MOISTURE AND THUS THE LIFT ASSOCIATED WITH THE LOW OVER CNTL
COLORADO WILL LIKELY PRODUCE MUCH LESS PRECIP THAN PREVIOUSLY
EXPECTED. THE 00Z MODEL SUITE MISSED THIS CRITICAL ELEMENT RESULTING
IN TOO MUCH WIDESPREAD QPF AND MOS GUIDANCE WHOSE POPS APPEAR TO BE
TOO HIGH. HAVE TRENDED THE FCST MUCH CLOSER TO THE 06Z RUC WHICH DID
INITIALIZE THE MCS AND SUBSEQUENTLY SEEMS TO HAVE A BETTER HANDLE ON
POSSIBLE PRECIP TODAY. THAT POSSIBILITY THEN SEEMS TO FOCUS ON
POTENTIAL FOR SCATTERED LIGHT SHOWERS MAINLY ACROSS THE NRN ZONES IN
AN AREA OF LIFT JUST AHEAD AND SOUTH OF THE TRACK OF THE UPPER LOW.
PRECIP HAS BEEN HARD TO COME BY VCNTY OF THE LOW WITH SOME LIGHT RA
AND SN IN SRN COLORADO AND SOME LIGHT RA SOUTH OF KABQ IN CNTL NM AS
A JET STREAK ROTATES AROUND THE BASE OF THE TROUGH.
IN THE NEAR TERM EVEN DRIZZLE CHANCES APPEAR TO BE ON THE WANE AS A
MID LEVEL DRY SLOT AND SOME APPARENT DOWNWARD MOTION TO THE REAR OF
THE CNTL TX MCS WORK IN ACROSS THE AREA. COULD SEE DRIZZLE TRY TO
REDEVELOP A LITTLE LATER THIS MORNING ONCE SOME WEAK LIFT WORKS BACK
OVER THE AREA...BUT EVEN MEASURABLE PRECIP FROM THIS ELEMENT LOOKING
VERY UNLIKELY.
TEMP FCST WILL BE TRICKY FOR THIS AFTN WITH SOME UNCERTAINTY
REGARDING HOW MUCH LOW STRATUS WILL REMAIN IN PLACE OR THIN. 00Z
MODELS APPEAR TO BE TOO AGGRESSIVE WITH WARMING AND HAVE TRENDED
TEMPS A BIT BELOW MOS. HOWEVER...ANY LATE DAY CLEARING OR LIFTING OF
CEILINGS AS THE CENTER OF THE LOW MOVES ACROSS THE SRN PANHANDLE
WOULD SEE TEMPS APPROACH THAT PROGGED BY MOS. THIS WOULD BE MOST
LIKELY TO OCCUR ACROSS THE SWRN ZONES.
MOVING INTO TONIGHT...LESSENING RAIN CHANCES SHOULD SHIFT EAST OF
THE AREA BY EARLY EVENING. MODELS KEEP LOW LEVEL MOISTURE LEVELS
PRETTY STEADY WHILE DROPPING WINDS OFF TO BECOME VERY LIGHT. SOME
HINTING OF FOG POTENTIAL LATE TONIGHT...AND IF MORE RAIN HAD FALLEN
IN THE LAST 24 HOURS OR MORE FALLS THAN EXPECTED OVER THE NEXT
SEVERAL HOURS WOULD BE MORE INCLINED TO MENTION AREAS OF FOG IN THE
FCST. STILL A BIT TOO MUCH UNCERTAINTY HERE AND WILL LET NEXT SHIFT
REEVALUATE THAT POTENTIAL.
LONG TERM...
A RETURN TO MORE SEASONABLE TEMPS REMAINS ON TRACK BEGINNING
TOMORROW AS THE SOUTH PLAINS SHAKES THE RECENT FORAY OF MODIFIED
CANADIAN AIR. A BEVERAGE SUCH AS CANADA DRY WOULD PROVE FITTING
FOR THE NEXT SEVERAL DAYS AS TRANSIENT RIDGING ALOFT CARRIES A
DOME OF VERY MILD AND DRY AIR EAST OVER MUCH OF THE SOUTH PLAINS.
BY FRIDAY...WE SHOULD SEE A PALTRY DRYLINE EVOLVE IN THE ROLLING
PLAINS BEHIND THE DEPARTING SURFACE HIGH. QUALITY RETURN FLOW
HOWEVER IS NOT EXPECTED UNTIL SATURDAY AT WHICH POINT STRONGER
WESTERLY WINDS ALOFT BEHIND THE UPPER RIDGE WILL SHUNT MUCH OF
THIS SHALLOW MOISTURE OUT OF ALL BUT OUR FAR EASTERN COLUMN OF
COUNTIES. A MINOR SHORT WAVE TROUGH IS STILL PROGGED TO SLIDE
THROUGH THIS STRONGER WESTERLY FLOW BY SAT NIGHT/SUN MORNING
ACCOMPANIED BY PERHAPS EVEN DRIER AND WARMER CONDITIONS ON
SUNDAY...BUT WILL STICK WITH SLIGHTLY COOLER CONDITIONS AS A
COLD FRONT WILL BE FOUND EDGING PERILOUSLY CLOSE TO OUR NRN
COUNTIES IN THE WAKE OF THIS UPPER IMPULSE.
BY EARLY NEXT WEEK...NO CHANGES ARE WARRANTED ATTM AS MODELS ARE
NOW IN MORE DISAGREEMENT THAN 24 HOURS AGO. WPC CONTINUES TO FAVOR
A SLOWER AND DEEPER LONGWAVE TROUGH EVOLVING IN THE GREAT BASIN
AND FOUR CORNERS REGION BY THIS TIME. ONLY SIMILARITY AMONG THE
CURRENT ECMWF AND GFS IS THAT THIS WAVE WOULD BE OPEN AND
PROGRESSIVE...THOUGH SIGNIFICANT DIFFERENCES EMERGE IN THE TIMING
OF SAID WAVE AND HOW MUCH CP AIR IS DRAWN SOUTHWARD FOLLOWING ITS
PASSAGE. WOULD STILL EXPECT A SEMI-ACTIVE DRYLINE TO UNFOLD NEAR
THE FRINGES OF OUR EASTERN COUNTIES AS EARLY AS MON AND PERHAPS
LINGERING INTO TUE UNDERNEATH AN INCREASINGLY UNSETTLED SWLY UPPER
FLOW REGIME. THE GEFS MEAN AND EVEN THE CMC INDICATE SUCH A
SCENARIO THAT AS OF YESTERDAY WAS FAVORED BY THE ECMWF...BUT WILL
AWAIT LATER MODEL RUNS BEFORE COMMITTING TO ANY CHANGES STILL SO
MANY PERIODS OUT.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 46 32 68 43 76 / 40 10 0 0 0
TULIA 41 32 67 43 77 / 40 10 0 0 0
PLAINVIEW 41 34 68 44 77 / 30 10 0 0 0
LEVELLAND 48 34 70 46 81 / 30 10 0 0 0
LUBBOCK 43 35 70 45 79 / 30 10 0 0 0
DENVER CITY 51 34 70 47 82 / 20 10 0 0 0
BROWNFIELD 48 35 70 46 82 / 30 10 0 0 0
CHILDRESS 43 35 64 43 78 / 40 20 0 0 0
SPUR 41 35 68 45 81 / 30 10 0 0 0
ASPERMONT 43 37 66 44 80 / 30 10 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07/93/07
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1128 AM MDT WED APR 3 2013
.UPDATE...
ISSUED AT 655 AM MDT WED APR 3 2013
UPDATED FORECAST TO REFLECT CURRENT CONDITIONS. REMOVED
DRIZZLE/FOG FROM SOUTHERN I-25 CORRIDOR AS VISIBILITY HAS BEEN
IMPROVING MOST AREAS. STILL SOME DENSE FOG AND PATCHY FREEZING
DRIZZLE ACROSS EL PASO COUNTY THROUGH MID-MRNG AS WINDS HAVE YET
TO GO NORTHERLY. ALSO ADDED A COUPLE HOURS OF LIGHT SNOW TO SAN
LUIS VALLEY...WHERE ALAMOSA HAS BEEN REPORTING SNOW THE PAST HOUR.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM MDT WED APR 3 2013
UPPER LOW GRADUALLY SLIPPING EASTWARD ACROSS THE STATE EARLY THIS
MORNING...AND SHOULD MOVE INTO THE SOUTHERN PLAINS BY THIS
EVENING. STILL SOME RESIDUAL -SHRA/-SHSN/-FZDZ ACROSS THE AREA
THIS MORNING...THOUGH RADAR TRENDS SUGGEST GRADUALLY DECREASING
COVERAGE AND INTENSITY SINCE 09Z. WILL HOLD ON TO SOME LIGHT
PRECIP THROUGH THE MORNING MOST AREAS...GRADUALLY ENDING FROM NW
TO SE BY MIDDAY. MAY SEE A FEW SHOWERS REFIRE OVER THE MTS THIS
AFTERNOON AS LAPSE RATES REMAIN FAIRLY STEEP...THOUGH PRECIP WILL
BE VERY LIGHT. PERSISTENT -FZDZ AND FZFG OVER EL PASO COUNTY MAY
LINGER THROUGH LATE MORNING...AS LATEST HRRR KEEPS WEAK SOUTHEAST
WIND IN PLACE UNTIL 17Z. STILL THINK N-NW FLOW WILL DEVELOP THIS
AFTERNOON AND GRADUALLY REMOVE ANY REMNANTS OF CLOUDS/FOG...THOUGH
FAR SOUTHEAST PLAINS MAY HAVE TO WAIT UNTIL VERY LATE AFTERNOON TO
SEE ANY SUN. WILL CONTINUE WITH REASONABLY MILD MAX TEMPS MOST
LOCATIONS...THOUGH KEPT AREAS AROUND SPRINGFIELD COLDER THAN
GUIDANCE DUE TO LINGERING CLOUDS. OVERNIGHT...WILL END PRECIP
QUICKLY IN THE EVENING WITH LOSS OF HEATING...LEADING TO A MOSTLY
CLEAR AND SEASONABLY COOL NIGHT MOST AREAS UNDER WEAK NORTHWEST
FLOW.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 352 AM MDT WED APR 3 2013
...SIGNIFICANT STORM POSSIBLE EARLY NEXT WEEK...
LATTER HALF OF THIS WEEK LOOKS QUITE PLEASANT AS A TRANSITORY RIDGE
CROSSES OUR AREA. THURSDAY MAY BE THE NICEST DAY...WITH DRY AND CLEAR
CONDITIONS EXPECTED AREA-WIDE. WINDS SHOULD BE RELATIVELY LIGHT WITH
THE RIDGE AXIS JUST WWD OF THE CWA. GIVEN THE LIGHT WINDS AND H7
TEMPS AROUND 4 DEGREES OR SO...HAVE GONE ON THE LOW SIDE OF MOS FOR
TEMPS ON THE PLAINS...WITH HIGHS EXPECTED TO BE IN THE UPPER 60S TO
AROUND 70 DEGREES.
FRIDAY...FIRE WX ISSUES ARISE AS THE RIDGE SHIFTS TO THE EAST...AND
ZONAL FLOW STRENGTHENS ACROSS THE CONTDVD. SHOULD SEE MARGINALLY
CRITICAL FIRE WX CONDITIONS DEVELOP ACROSS THE PLAINS AS RH DROPS TO
BELOW 15 PERCENT AND W WINDS BECOME RATHER GUSTY BY AFTERNOON.
FOR THE WEEKEND...A WEAK SHORTWAVE TROUGH WILL MOVE THROUGH THE NRN
ROCKIES...AND WILL LIKELY SPARK SCT-NMRS SHOWERS ACROSS THE MTS
ESPECIALLY SAT AFTERNOON-EVE. MAIN CHANCES FOR PRECIP WILL BE N OF
HIGHWAY 50 BOTH DAYS. TEMPS SHOULD REMAIN QUITE PLEASANT...IN THE MID
60S ACROSS THE PLAINS AND 50S FOR THE MTS AND HIGH VALLEYS.
MAIN FOCUS IN THE EXTENDED CONTINUES TO BE THE LARGE SPRING STORM
SYSTEM THAT IS EXPECTED TO AFFECT OUR AREA BY LATE IN THE WEEKEND
THROUGH THE FIRST HALF OF NEXT WEEK. ENSEMBLE MEANS CONTINUE TO SHOW
A DEEP TROUGH MOVING THROUGH THE SRN ROCKIES FROM MON THROUGH
WEDNESDAY. OP RUNS OF THE GFS AND ECMWF ALSO CONTINUE TO SHOW A DEEP
TROUGH MOVING THROUGH THE SOUTHERN ROCKIES DURING THIS TIME FRAME.
HOWEVER...SIGNIFICANT DIFFERENCES REMAIN IN THE EVOLUTION OF THE
TROUGH PER THE GFS AND EC. THE 00Z EC IS MORE PROGRESSIVE...BUT
SPLITS THE TROUGH...WITH THE MAIN ENERGY ARRIVING SUNDAY NIGHT THRU
MONDAY...AND A SECONDARY LOW MOVING THROUGH NEXT WED. THE GFS BRINGS
THE LOW THROUGH IN ONE PIECE...BUT IS SLOWER AND TARGETS THE MON
NIGHT-TUESDAY TIME FRAME FOR THE HIGHEST POPS. BOTH MODELS PROG
SIGNIFICANT QPF FOR SE CO...BETWEEN 1-2 INCHES OF LIQUID FOR THE
SUN-WED TIME PERIOD. BOTH MODELS ALSO TARGET THE SERN MTS FOR THE
HIGHEST PRECIP POTENTIAL. WHILE SNOW LEVELS LOOK TO REMAIN FAIRLY
HIGH FOR THE BULK OF THIS EVENT...THE SE MTS ABOVE 7000 FEET WOULD
PICK UP SIGNIFICANT SNOWFALL IN EITHER SCENARIO. THE ECMWF BRINGS IN
UNUSUALLY COLD AIR BEHIND THE TROUGH BY WED...WITH H7 TEMPS
BOTTOMING OUT NEAR MINUS 16 DEGREES. IF THIS OCCURS...THE HIGH TEMPS
FOR NEXT WED MAY NEED TO BE SUBSTANTIALLY REDUCED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1121 AM MDT WED APR 3 2013
KCOS AND KPUB...EXPECT THE LOW CIGS TO CLEAR WITHIN THE NEXT HOUR
OR SO. SAT PIX IMGY CONTINUES TO SHOW LOW CLOUDS DISSIPATING FROM
NW/SE WITH TIME.
WINDS AT KCOS THIS AFTERNOON MAY BE QUITE VARIABLE. HI RES
SIMULATIONS SHOW A BOUNDARY EXTENDING E-W ACROSS W EL PASO COUNTY.
WINDS N OF THE BOUNDARY ARE NORTHERLY AND SOUTH OF THE BOUNDARY
THEY ARE SOUTHERLY. THIS BOUNDARY IS FCST TO WOBBLE DURING THE
AFTERNOON AND THIS COULD CAUSE WINDS TO VARY SUBSTANTIALLY OVER
THE KCOS TAF SITE. OVERALL...THE MODELS SHOW THE BOUNDARY STAYING
N OF KCOS PROPER...AND FOR THIS REASON I PUT IN A PREDOMINANT
SOUTHERLY WIND FOR KCOS THIS AFTERNOON.
IN ADDITION...I CANNOT RULE OUT SOME LOCAL GROUND FOG LATER
TONIGHT AT ALL 3 TAF SITES...BUT PROBABILITY IS TOO LOW FOR ME TO
MENTION IT EXPLICITLY IN THE TAF.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...PETERSEN
SHORT TERM...PETERSEN
LONG TERM...ROSE
AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS BILLINGS MT
314 PM MDT WED APR 3 2013
.SHORT TERM...VALID FOR THU AND FRI...
COLD FRONT HAD PUSHED THROUGH THE FRONT RANGE OF MONTANA BY EARLY
AFTERNOON AND IS CHUGGING ALONG PRETTY GOOD. I LIKE THE RAP MODELS
TIMING WHICH SWITCHES BILLINGS WINDS TO THE NORTHEAST LATE THIS
AFTERNOON AND SHERIDANS BY 8 PM. THE RAP ALSO BRINGS EASTERLY WIND
INTO LIVINGSTON AT THAT POINT...BUT WE ARE LESS CONFIDENT IN THIS
OCCURRING...AND BELIEVE THE COOLER AIR MIGHT STAY JUST EAST OF
LIVINGSTON DOORSTEP. AT ANY RATE MODELS ARE GENERATING DECENT
FRONTOGENESIS OVER OUR WESTERN ZONES LATE TODAY AND THERE APPEARS
TO BE SOME MODEST CONVECTION DEVELOPING JUST UPSTREAM OF THIS
AREA. SOME WEAK ENERGY CONTINUES TO MOVE ACROSS EAST CENTRAL
MONTANA OVERNIGHT...SO WILL CONTINUE TO INCLUDE SOME LOW POPS
AFTER MIDNIGHT.
THURSDAY OUR FORECAST AREA WILL GENERALLY BE BETWEEN SYSTEMS WITH
LOW AMPLITUDE RIDGING AND SURFACE TROUGHING DEVELOPING BEFORE
EVENING. THE MAIN WEATHER FEATURE THURSDAY WILL BE THE BACKING
UPPER FLOW BRINGING A NICE FETCH OF PACIFIC MOISTURE INTO THE
INNER ROCKIES. SO WE EXPECT INCREASING CLOUD COVER TO LIMIT
TEMPERATURES AND MIXING SOMEWHAT. BY THURSDAY NIGHT...WEAK ENERGY
INVOLVED WITH THAT MOISTURE FETCH MAY SPREAD SOME LIGHT SHOWERS
ACROSS THE REGION. HOWEVER THE MAIN PLAYER CONTINUES TO BE A LOW
AMPLITUDE SHORT WAVE PROGGED TO CROSS OUR FORECAST AREA FRIDAY.
MODELS AGREE THAT Q VECTOR FORCING WILL BE RIGHT OVER OUR ZONES
FRIDAY AFTERNOON WITH DECENT CAPE ON THE ORDER FROM 200-400 JL/KG.
I CONTINUED TO NUDGE THE POPS UP FOR FRIDAY AFTERNOON IN MANY
LOCATIONS AND WENT CATEGORICAL IN THE HIGH COUNTRY. THE GFS
LINGERS QPF OVER OUR FORECAST AREA WELL INTO FRIDAY NIGHT...BUT
THE OVERALL CONSENSUS OF MODELS GENERALLY EXIT THIS FORCING TO
THE EAST IN THE EVENING. THIS SEEMS MORE LIKELY GIVEN THE GOOD
CONVERGENT/DIVERGENT COUPLET...SO TRENDED OUR POPS LOWER
OVERNIGHT. BT
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
FAIRLY ACTIVE AND SPRING-LIKE WEATHER PATTERN SHAPING UP FOR THE
EXTENDED PERIOD...THOUGH LATEST MODELS HAVE SHIFTED A BIT FOR THE
MON/TUE TIME FRAME.
SATURDAY STILL LOOKING FAIRLY QUIET WITH RIDGING BEHIND LATE
FRIDAY WAVE. HAVE REDUCED POPS FOR ALL BUT OUR WEST...WHICH
SHOULD BEGIN TO SEE INCREASED SHOWER ACTIVITY BY AFTERNOON...AND
PER WESTERLY DOWNSLOPE WINDS HAVE ALSO RAISED TEMPS A FEW DEGREES.
SHOULD SEE HIGHS INTO THE LOWER/MID 60S.
MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH TIMING A SHORTWAVE
THROUGH THE REGION SATURDAY NIGHT. WITH INCREASING CONFIDENCE HAVE
RAISED POPS A BIT MORE...TO LIKELY IN CENTRAL AND EAST PARTS AWAY
FROM THE DOWNSLOPING WESTERN FOOTHILLS. AIRMASS LOOKS TO BE TOO
WARM FOR ANYTHING BUT RAIN SHOWERS AT OUR LOWER ELEVATIONS...WITH
A POSSIBLE EXCEPTION IN OUR FAR NE WHERE LOW LEVEL EAST WINDS MAY
KEEP 850MB TEMPS NEAR ZERO. SO WILL KEEP A RAIN/SNOW MIX WITH
JUST A LITTLE ACCUMULATION FROM MILES CITY TO BAKER...BUT THE
BETTER SNOW POTENTIAL REALLY SHOULD BE NORTH AND NORTHEAST OF OUR
CWA. SYSTEM WILL EXIT QUICKLY INTO THE DAKOTAS AROUND 12Z SUNDAY.
NEXT PACIFIC ENERGY WILL BEGIN TO INFLUENCE OUR WEST BY SUNDAY
AFTERNOON OR NIGHT...SOME TIMING ISSUES EXIST HERE. THEN...AS
PREVIOUSLY MENTIONED...MODELS ARE BEGINNING TO PAINT A DIFFERENT
PICTURE WITH EVOLUTION OF THIS SYSTEM INTO MON/TUE. FLOW IN THE
EASTERN PACIFIC NOW EXPECTED TO BE A BIT FLATTER...WITH
AMPLIFICATION OVER THE WESTERN CONUS SHIFTED A BIT EAST. THUS...
PER LATEST TRENDS...A LARGE CLOSED LOW OVER THE GREAT BASIN TO
4-CORNERS REGION NOW LOOKS LESS LIKELY...WHICH LEAVES A WNW FLOW
WITH LOWER HEIGHTS OVER OUR REGION AS ENERGY DRIVES TO THE CENTRAL
ROCKIES AND MIDDLE PLAINS. COULD STILL SEE SOME WET SNOW IMPACTS
IN OUR AREA SOMETIME IN THE SUNDAY NIGHT INTO TUESDAY TIME
FRAME...AND BOTH THE GFS AND EC SHOW 850MB TEMPS NEAR OR SLIGHTLY
BELOW ZERO...BUT OVERALL POTENTIAL APPEARS LOWER NOW. PROGRESSIVE
SHORTWAVE ENERGY IN LOW HEIGHT REGIME AND LOW LEVEL UPSLOPE FLOW
ALL COMBINE TO WARRANT ABOVE CLIMO POPS FOR US NONETHELESS. WILL
TAPER POPS TO BELOW CLIMO...SLIGHT CHANCE...BY WEDNESDAY AS MODEL
CONSENSUS IS FOR RISING HEIGHTS WITH RIDGE BEGINNING TO BUILD OVER
THE PAC NW BY THEN.
AS FOR TEMPERATURES...ABOVE NORMAL SATURDAY SHOULD COOL TO NEAR
NORMAL SUNDAY AND BELOW NORMAL MONDAY AND TUESDAY. COULD SEE A
RETURN TO NEAR OR ABOVE NORMAL TEMPS BY THE MIDDLE OF NEXT WEEK...
AND HAVE ADJUSTED GRIDS ACCORDINGLY.
JKL
&&
.AVIATION...
A CANADIAN COLD FRONT IS PUSHING SOUTHWARD THROUGH THE AREA THIS
AFTERNOON...CAUSING GUSTY NW-N-NE WINDS ACROSS THE LOWER
ELEVATIONS...WITH GUSTS TO 25 KTS UNTIL SUNSET. EXPECT ISOLATED TO
SCATTERED SHOWERS TO DEVELOP ALONG THIS FRONTAL BOUNDARY FROM KLVM
TO KBIL AND KSHR THROUGH AROUND 04Z...WITH DRYING ANTICIPATED
LATER TONIGHT. LOCALIZED MVFR IS POSSIBLE WITH THE SHOWER
ACTIVITY. VFR CONDITIONS WILL PREVAIL ACROSS THE AREA LATE TONIGHT
AND THURSDAY. JKL
&&
.PRELIMINARY POINT TEMP/POPS...
THU FRI SAT SUN MON TUE WED
-----------------------------------------------------------
BIL 034/064 043/064 038/063 038/057 032/046 029/048 030/056
20/B 37/T 32/W 52/W 35/W 42/W 22/W
LVM 033/064 039/058 033/061 031/055 029/044 028/046 028/055
31/B 26/T 24/W 53/W 35/J 32/W 22/W
HDN 033/065 041/068 038/065 036/059 031/047 029/049 028/054
20/B 37/T 32/W 62/W 35/W 42/W 22/W
MLS 031/057 038/067 038/061 035/055 029/045 027/045 026/049
32/W 24/T 31/B 62/W 24/W 42/W 22/W
4BQ 031/064 040/066 038/062 036/056 032/046 028/044 024/046
21/B 14/T 41/B 63/W 24/W 43/W 22/W
BHK 027/050 032/061 035/055 031/050 027/041 023/041 023/043
33/W 13/T 31/B 64/W 33/W 33/J 22/W
SHR 032/064 039/066 035/061 033/056 030/045 027/045 027/051
20/B 14/T 31/B 32/W 35/W 43/W 22/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1248 PM CDT WED APR 3 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 314 AM CDT WED APR 3 2013
THE RAP...NAM AND GFS ARE SUGGESTING SUFFICIENT LOW AND MID LEVEL
CLOUDINESS ACROSS SRN NEB TO HOLD TEMPS IN THE 50S TODAY. AT THE
SAME TIME SOUTH AND SOUTHWEST WINDS WILL RECIRCULATE COOL AIR NORTH
FROM THE HIGH PRESSURE SYSTEM ACROSS THE MID SOUTH. SO THE RAP 21Z
TEMPS WERE USED AS THE BASIS FOR TODAYS HIGHS WHICH IS CLOSE TO THE
GUIDANCE DATA SETS. IF FULL SUN ARRIVES OR EVEN JUST HIGH LEVEL
CLOUDINESS...HIGHS COULD BE A FEW DEGREES WARMER.
THE BEST GUESS ON TONIGHTS LOWS IS FOR THE CLOUDS TO DEPART WITH
WEAK SFC WINDS DEVELOPING AHEAD OF A COLD FRONT MOVING THROUGH SOUTH
DAKOTA WHICH WOULD SUPPORT SOME RADIATIONAL COOLING ACROSS NEB. LOWS
IN THE UPPER 20S TO MID 30S APPEARS TO BE THE BEST FORECAST.
ADDITIONAL COOLING FROM THE DROUGHT CONDITIONS COULD PUSH LOWS
FURTHER.
THE REST OF THE FCST IS WELL BEHAVED. WINDS COULD REACH THE BREEZY
CATEGORY BUT RELATIVE HUMIDITY WILL RUN 25 TO 30 PERCENT. THE RAP
SUGGESTED LOWER RH ACROSS FAR NORTHWEST NEB AS THE FRONT NOSES SOUTH
LATE THIS AFTN BUT AT THE SAME TIME WINDS WEAKEN.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 314 AM CDT WED APR 3 2013
12Z THURSDAY AND BEYOND. TWO MAIN CONCERNS GOING IN
THE EXTENDED PERIOD. FIRST BEING THE POTENTIAL FOR FIRE HEADLINES
ON FRIDAY...THEREAFTER THE FOCUS TURNS TO THE DEVELOPMENT OF A
WESTERN CONUS TROUGH...WHICH MAY BRING PERIODS OF WIDESPREAD
PRECIPITATION BACK ACROSS THE FORECAST AREA LATE THIS WEEKEND
THROUGH EARLY NEXT WEEK.
SURFACE TEMPERATURES WILL SLOWLY MODERATE FROM WEST TO EAST ON
THURSDAY AS SURFACE HIGH PRESSURE SLOWLY BUILDS EAST ACROSS THE
NORTHERN PLAINS AND ALLOWS FOR A RETURN SOUTHERLY FLOW. A TIGHT
GRADIENT IS EXPECTED IN THE TEMPERATURE FIELD...WITH HIGHS POSSIBLY
APPROACHING 70 ACROSS SOUTHWEST NEBRASKA...BUT READINGS OF ONLY THE
LOW TO MID 50S OVER NORTH CENTRAL NEBRASKA. FOR FRIDAY...THE
NORTHERN PLAINS HIGH WILL BE LOCATED OVER THE GREAT LAKES REGION
WITH STRONG SOUTHERLY RETURN FLOW TARGETING THE ENTIRE FORECAST
AREA. WITH DEEPENING LOW PRESSURE ON THE LEE OF THE ROCKIES...A
TIGHT PRESSURE GRADIENT IS EXPECTED...WITH THE POTENTIAL FOR WIND
GUSTS IN EXCESS OF 25 MPH. MEANWHILE SFC TEMPERATURE AND DEW POINT
SPREADS WILL APPROACH 40 F...WHICH SHOULD LEAD TO LOCALIZED AREAS OF
SUB 20 PERCENT RH. GIVEN THAT GREEN UP HAS NOT YET
OCCURRED...LOCALIZED RED FLAG CONDITIONS ARE POSSIBLE. UNCERTAINTY
REMAINS IF THE RED FLAG CRITERIA WIND GUSTS WILL BE CO-LOCATED
WITHIN THE CRITICAL RH FIELD. AT THIS TIME...IT APPEARS THAT THE
STRONGEST GUSTS SHOULD OCCUR OVER EASTERN PORTIONS OF THE
CWA...WHERE THE SOUTHERLY FLOW SHOULD HELP PUSH TD/S UP NEAR
40...WHICH WOULD KEEP MINIMUM RH IN THE 20-30 PERCENT RANGE. THE
DRIEST AIR IS EXPECTED ACROSS THE WESTERN HALF OF THE CWA...SLIGHTLY
REMOVED FROM THE STRONGEST GUSTS. OBVIOUSLY THERE IS STILL TIME TO
HAMMER OUT THE DETAILS...BUT GIVEN A FAVORABLE FIRE WX PATTERN
/RIDGE BREAKDOWN/ AND THE FACT THAT WIND SHIFT IS EXPECTED LATE
AFTERNOON/EVENING AS A SURFACE TROUGH AND COLD FRONT ADVANCE EAST
ACROSS THE CWA...ITS SAFE TO SAY AT THIS JUNCTURE THAT ELEVATED FIRE
CONCERNS ARE CERTAINLY WARRANTED...WILL CONTINUE TO MONITOR. ALSO
OF CONCERN...PROXIMITY SOUNDINGS INDICATE WEAK INSTABILITY ALONG THE
FRONTAL PASSAGE...BUT DRY LOWER LEVELS...A FEW DRIER CG STRIKES COULD
OCCUR. OTHERWISE HIGH TEMPERATURES WILL COOL SOME TEN DEGREES FROM
THE MID 70S DOWN TO THE UPPER 50S TO MID 60S ON SATURDAY. LOWS
FRIDAY AND SATURDAY MORNING WILL BE MILD RELATIVELY SPEAKING...WITH
LOWS IN THE 30S FRIDAY...AND LOWS IN THE 40S SATURDAY MORNING.
ATTENTION NOW TURNS TO THE MYRIAD OF POTENTIAL WEATHER FOR LATE
SUNDAY THROUGH EARLY NEXT WEEK...BUT UNFORTUNATELY THE 03.00Z RUN OF
THE MODELS FAILED TO INCREASE FORECAST CONFIDENCE AS SIGNIFICANT
DIFFERENCES IN TIMING AND STRENGTH OF THE WESTERN CONUS TROUGH
EXISTS. THE GENERAL IDEA IS THAT A SHORTWAVE WILL CROSS THE
CENTRAL/NORTHERN PLAINS ON SUNDAY PROVIDING FOR SHOWERS AND/OR
TSTMS...THEN THE MEAN TROUGH WILL DEVELOP OVER THE ROCKIES AND
SLOWLY ADVANCE OUT ONTO THE PLAINS EARLY NEXT WEEK. THE EC SOLUTION
CONTINUES TO ADVERTISE ENOUGH COLD AIR ON THE BACK SIDE OF THE MAIN
H5 LOW TO ALLOW FOR SNOW ACCUMULATIONS...WHICH MAY BE SIGNIFICANT.
ALSO OF NOTE...THE EC DEVELOPS H85 WINDS IN EXCESS OF 60KTS EARLY
TUESDAY ACROSS EASTERN PORTIONS OF THE CWA. THE EURO HAS SHOWN A
COLD BIAS WITH IT/S LAST STORM THAT AFFECTED OUR CWA...SO THE AMOUNT
OF COOLING IS SUSPECT. THE GFS IS SHOWING A BIT MORE OF A SOUTHERLY
TRACK OF THE MEAN TROUGH...AND IS LESS NEGATIVELY TILTED...BUT THE
GFS ENSEMBLE MEAN GIVES SUPPORT TO THE EC SOLUTION. AS STATED
PREVIOUSLY...CONFIDENCE IN ANY PARTICULAR SOLUTION IS LOW...THUS
WILL MAINTAIN 40 PERCENT POPS OR LESS THROUGH THE EVENT AND KEEP THE
GENERAL IDEA OF SHOWERS OF RAIN INITIALLY...THEN POSSIBLY CHANGING
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1243 PM CDT WED APR 3 2013
UPPER LEVEL LOW PRESSURE SYSTEM CONTINUES TO MOVE SLOWLY EAST
ACROSS KS. SOME MID AND HIGH LEVEL CLOUDS HAVE SPREAD INTO
SOUTHWEST NEBRASKA WITH THIS SYSTEM. OTHERWISE A BRISK SOUTH TO
SOUTHWEST WIND...WITH GUSTS OF 25 TO 30 KTS WILL CONTINUE THROUGH
THE AFTERNOON. WINDS WILL DECREASE TONIGHT WITH CONTINUE VFR.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...TAYLOR
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1227 PM CDT WED APR 3 2013
.UPDATE...
SEE UPDATED AVIATION DISCUSSION BELOW.
LATE MORNING UPDATE TODAY INCLUDED INCREASING WIND SPEEDS AND
ENHANCING A CORRIDOR OF STRONGER WINDS ALONG AND JUST EAST OF THE
EASTERN SLOPE OF THE PRAIRIE COTEAU. LEFT EVERYTHING ELSE AS IS
SINCE THERMAL ADVECTION SUGGESTS WE SHOULD GET CLOSE TO ADVERTISED
HIGH TEMPS TODAY...AND LATEST HRRR AND 12Z SPC WRF CONTINUES TO
HINT AT ISOLATED TO WIDELY SCATTERED WEAK CONVECTION THIS
AFTERNOON THROUGH EARLY THIS EVENING.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH FRIDAY
MAIN CONCERNS THROUGH THE PERIOD ARE TEMPERATURES AND PCPN CHANCES.
FOR TODAY THE REGION SHOULD BASK IN A RELATIVELY MILD AIRMASS AS
SOUTHWEST BREEZES KICK IN AHEAD OF AN ADVANCING FRONT. MODEL H85
TEMPS ARE EXPECTED TO RANGE FROM 5 TO 10 DEGREES C WHICH SUGGESTS
THE SOUTHWEST CWA SHOULD GET CLOSE TO 70 PROVIDED MIXING IS
SUFFICIENT. THE NORTHEAST CWA REMAINS PROBLEMATIC AS SNOW IS STILL
COVERING A MAJOR PORTION OF THE GLACIAL LAKES AREA. FOR NOW AM
GOING CLOSE TO A MODEL BLEND FOR THAT REGION. MEANWHILE THE MODELS
CONTINUE TO CRANK OUT SOME LIGHT PCPN JUST BEHIND THE FRONT LATE
TODAY AND TNT AS IT CROSSES THE CWA. TIME HEIGHTS AND SOUNDINGS
INDICATE SOME LOWER LEVEL DRY AIR THAT WOULD HAVE TO BE OVERCOME
FOR MUCH IN THE WAY OF MEASURABLE PCPN. SO...SLIGHT CHANCE POPS
LOOK FINE. IT SHOULD THEN BE MAINLY DRY FOR THURSDAY THROUGH
FRIDAY BEFORE THE NEXT SYSTEM MOVES IN LATER ON FRIDAY. THAT
SYSTEM SHOULD BRING SOME WAA PCPN TO THE NORTHERN PARTS OF THE
STATE FRIDAY INTO FRIDAY NIGHT. FOR NOW IT APPEARS TO BE MOSTLY
RAIN GIVEN EXPECTED TEMPERATURES AND PROGGED PARTIAL THICKNESS.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
FAIRLY ACTIVE PATTERN LOOKS TO BE SETTING UP ACROSS THE NORTHERN
PLAINS WITH THE FIRST WAVE OF INTEREST MOVING THROUGH THE AREA
FRIDAY NIGHT AND SATURDAY. MODELS IN GENERAL AGREEMENT IN MOVING
THE SFC LOW EASTWARD ACROSS SOUTHERN SOUTH DAKOTA. CONFIDENCE IS
INCREASING IN THERE BEING PRECIP NORTH OF THE WARM FRONT ACROSS
THE NORTHEASTERN CWA. HAVE INCREASED POPS A BIT. AS THE SFC LOW
MOVES INTO MN BY SATURDAY...COLDER AIR WRAPS INTO THE
CWA...ALTHOUGH MODELS ARE STILL VARYING QUITE A BIT IN THEIR
THERMAL PROFILES ON THE BACK SIDE OF THIS SYSTEM. EC IS RATHER
WARM WHILE GFS IS COOLER. FOR RIGHT NOW HAVE JUST ALL RAIN IN THE
FORECAST BUT IF MODELS TURN A BIT COLDER...COULD ALSO SEE SOME
SNOW MIXED IN AS WELL BY SATURDAY MORNING. IT LOOKS LIKE ANOTHER
DECENT LOOKING WAVE MOVES THROUGH ON SUNDAY...WITH FAIR AGREEMENT
AMONGST THE MODELS. GENERALLY ACCEPTED ALLBLEND POP GRIDS FOR THIS
SYSTEM. HEADING INTO EARLY NEXT WEEK THINGS BECOME MUCH MORE
UNCERTAIN. ALLBLEND POPS MAY BE OVERDONE INTO EARLY NEXT WEEK AS
MODELS ARE SHOWING SFC HIGH RIDGING ACROSS THE AREA...BUT ALLBLEND
GIVING POPS. MAY NEED TO BACK OFF MORE ON THIS. MODELS HAVE
TRENDED A BIT FURTHER SOUTH WITH ANOTHER POTENTIAL STORM SYSTEM
EARLY NEXT WEEK.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF FORECAST PERIOD.
BREEZY SOUTHERLY SFC WINDS WILL CONTINUE ACROSS THE REGION THIS AFTERNOON.
A COLD FRONT WILL SWEEP SOUTHEAST ACROSS THE AREA THIS AFTERNOON
AND EVENING...SWITCHING SFC WINDS TO A NORTHERLY DIRECTION. SOME
LIGHT SHOWERS ARE POSSIBLE AHEAD OF THIS FRONT. CURRENTLY A LINE
STRETCHES FROM BISMARCK TO LEMMON PROGRESSING SOUTHEASTWARD. NO
IMPACTS ARE EXPECTED TO TAFS WITH THESE SHOWERS.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...WISE
SHORT TERM...TDK
LONG TERM...TMT
AVIATION...WISE
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1222 PM CDT WED APR 3 2013
.UPDATE...
LATE MORNING UPDATE TODAY INCLUDED INCREASING WIND SPEEDS AND
ENHANCING A CORRIDOR OF STRONGER WINDS ALONG AND JUST EAST OF THE
EASTERN SLOPE OF THE PRAIRIE COTEAU. LEFT EVERYTHING ELSE AS IS
SINCE THERMAL ADVECTION SUGGESTS WE SHOULD GET CLOSE TO ADVERTISED
HIGH TEMPS TODAY...AND LATEST HRRR AND 12Z SPC WRF CONTINUES TO
HINT AT ISOLATED TO WIDELY SCATTERED WEAK CONVECTION THIS
AFTERNOON THROUGH EARLY THIS EVENING.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH FRIDAY
MAIN CONCERNS THROUGH THE PERIOD ARE TEMPERATURES AND PCPN CHANCES.
FOR TODAY THE REGION SHOULD BASK IN A RELATIVELY MILD AIRMASS AS
SOUTHWEST BREEZES KICK IN AHEAD OF AN ADVANCING FRONT. MODEL H85
TEMPS ARE EXPECTED TO RANGE FROM 5 TO 10 DEGREES C WHICH SUGGESTS
THE SOUTHWEST CWA SHOULD GET CLOSE TO 70 PROVIDED MIXING IS
SUFFICIENT. THE NORTHEAST CWA REMAINS PROBLEMATIC AS SNOW IS STILL
COVERING A MAJOR PORTION OF THE GLACIAL LAKES AREA. FOR NOW AM
GOING CLOSE TO A MODEL BLEND FOR THAT REGION. MEANWHILE THE MODELS
CONTINUE TO CRANK OUT SOME LIGHT PCPN JUST BEHIND THE FRONT LATE
TODAY AND TNT AS IT CROSSES THE CWA. TIME HEIGHTS AND SOUNDINGS
INDICATE SOME LOWER LEVEL DRY AIR THAT WOULD HAVE TO BE OVERCOME
FOR MUCH IN THE WAY OF MEASURABLE PCPN. SO...SLIGHT CHANCE POPS
LOOK FINE. IT SHOULD THEN BE MAINLY DRY FOR THURSDAY THROUGH
FRIDAY BEFORE THE NEXT SYSTEM MOVES IN LATER ON FRIDAY. THAT
SYSTEM SHOULD BRING SOME WAA PCPN TO THE NORTHERN PARTS OF THE
STATE FRIDAY INTO FRIDAY NIGHT. FOR NOW IT APPEARS TO BE MOSTLY
RAIN GIVEN EXPECTED TEMPERATURES AND PROGGED PARTIAL THICKNESS.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
FAIRLY ACTIVE PATTERN LOOKS TO BE SETTING UP ACROSS THE NORTHERN
PLAINS WITH THE FIRST WAVE OF INTEREST MOVING THROUGH THE AREA
FRIDAY NIGHT AND SATURDAY. MODELS IN GENERAL AGREEMENT IN MOVING
THE SFC LOW EASTWARD ACROSS SOUTHERN SOUTH DAKOTA. CONFIDENCE IS
INCREASING IN THERE BEING PRECIP NORTH OF THE WARM FRONT ACROSS
THE NORTHEASTERN CWA. HAVE INCREASED POPS A BIT. AS THE SFC LOW
MOVES INTO MN BY SATURDAY...COLDER AIR WRAPS INTO THE
CWA...ALTHOUGH MODELS ARE STILL VARYING QUITE A BIT IN THEIR
THERMAL PROFILES ON THE BACK SIDE OF THIS SYSTEM. EC IS RATHER
WARM WHILE GFS IS COOLER. FOR RIGHT NOW HAVE JUST ALL RAIN IN THE
FORECAST BUT IF MODELS TURN A BIT COLDER...COULD ALSO SEE SOME
SNOW MIXED IN AS WELL BY SATURDAY MORNING. IT LOOKS LIKE ANOTHER
DECENT LOOKING WAVE MOVES THROUGH ON SUNDAY...WITH FAIR AGREEMENT
AMONGST THE MODELS. GENERALLY ACCEPTED ALLBLEND POP GRIDS FOR THIS
SYSTEM. HEADING INTO EARLY NEXT WEEK THINGS BECOME MUCH MORE
UNCERTAIN. ALLBLEND POPS MAY BE OVERDONE INTO EARLY NEXT WEEK AS
MODELS ARE SHOWING SFC HIGH RIDGING ACROSS THE AREA...BUT ALLBLEND
GIVING POPS. MAY NEED TO BACK OFF MORE ON THIS. MODELS HAVE
TRENDED A BIT FURTHER SOUTH WITH ANOTHER POTENTIAL STORM SYSTEM
EARLY NEXT WEEK.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF FORECAST PERIOD.
BREEZY SOUTHERLY SFC WINDS WILL DEVELOP ACROSS THE REGION TODAY. A
COLD FRONT WILL THEN SWEEP SOUTHEAST ACROSS THE AREA THIS
EVENING...SWITCHING SFC WINDS TO A NORTHERLY DIRECTION.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...DORN
SHORT TERM...TDK
LONG TERM...TMT
AVIATION...TMT
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1244 PM CDT WED APR 3 2013
.AVIATION...
CONDITIONS AT KLBB ARE EXPECTED TO IMPROVE THIS AFTERNOON AS DRY
SLOT ROTATING ACROSS THE UPPER LEVEL LOW TO OUR NORTHWEST HELPS TO
DRY LOW LEVEL CONDITIONS. CLOUDS ARE EXPECTED TO HANG AROUND KCDS
THOUGH SOME UNCERTAINTY EXISTS IN THE FLIGHT CATEGORY AS IFR
CONDITIONS PERSIST JUST NORTH OF THAT TERMINAL. INTO THE OVERNIGHT
HOURS...CLEARING SKIES AND LIGHT WINDS WILL LIKELY HELP FOG
FORMATION. HAVE GONE FAIRLY CONSERVATIVELY ON VISIBILITY FOR NOW
THOUGH VLIFR IS POSSIBLE.
&&
.PREV DISCUSSION... /ISSUED 634 AM CDT WED APR 3 2013/
AVIATION...
IFR CONDITIONS LIKELY TO PERSIST INTO THE AFTN HOURS AT BOTH TAF
SITES. KLBB MAY SEE SOME LIFTING OF THE CIGS THIS AFTN THEN
PROBABLY SCATTER OUT THIS EVENING. KCDS LOOKS LESS LIKELY TO SEE
MUCH IMPROVEMENT UNTIL LATE IN THE TAF PERIOD OR BEYOND.
DEEP MOISTURE NOT AS RICH AS EXPECTED WHICH WILL RESULT IN GREATLY
REDUCED PRECIP CHANCES TODAY. BOTH TAF SITES...KCDS MORESO THAN
KLBB...COULD SEE SOME LIGHT SHOWERS BUT CHANCES NOW LOOK TO SLIM
TO MENTION GIVEN RESTRICTIONS ON PROB30 GROUP WITHIN FIRST 9
HOURS OF TAF PERIOD.
PREV DISCUSSION... /ISSUED 410 AM CDT WED APR 3 2013/
SHORT TERM...
MAJOR CHANGE TO THE FCST THIS MORNING IS TO CONSIDERABLY LOWER POPS
ACROSS THE AREA. UNFORTUNATELY...PREVIOUS MODEL RUNS MISSED THE
EXTENSIVE MCS THAT MOVED ACROSS AREAS FROM NW TEXAS TO SOUTH TEXAS.
IT APPEARS THAT THIS MCS WILL LEAVE THE FCST AREA STARVED OF DEEP
MOISTURE AND THUS THE LIFT ASSOCIATED WITH THE LOW OVER CNTL
COLORADO WILL LIKELY PRODUCE MUCH LESS PRECIP THAN PREVIOUSLY
EXPECTED. THE 00Z MODEL SUITE MISSED THIS CRITICAL ELEMENT RESULTING
IN TOO MUCH WIDESPREAD QPF AND MOS GUIDANCE WHOSE POPS APPEAR TO BE
TOO HIGH. HAVE TRENDED THE FCST MUCH CLOSER TO THE 06Z RUC WHICH DID
INITIALIZE THE MCS AND SUBSEQUENTLY SEEMS TO HAVE A BETTER HANDLE ON
POSSIBLE PRECIP TODAY. THAT POSSIBILITY THEN SEEMS TO FOCUS ON
POTENTIAL FOR SCATTERED LIGHT SHOWERS MAINLY ACROSS THE NRN ZONES IN
AN AREA OF LIFT JUST AHEAD AND SOUTH OF THE TRACK OF THE UPPER LOW.
PRECIP HAS BEEN HARD TO COME BY VCNTY OF THE LOW WITH SOME LIGHT RA
AND SN IN SRN COLORADO AND SOME LIGHT RA SOUTH OF KABQ IN CNTL NM AS
A JET STREAK ROTATES AROUND THE BASE OF THE TROUGH.
IN THE NEAR TERM EVEN DRIZZLE CHANCES APPEAR TO BE ON THE WANE AS A
MID LEVEL DRY SLOT AND SOME APPARENT DOWNWARD MOTION TO THE REAR OF
THE CNTL TX MCS WORK IN ACROSS THE AREA. COULD SEE DRIZZLE TRY TO
REDEVELOP A LITTLE LATER THIS MORNING ONCE SOME WEAK LIFT WORKS BACK
OVER THE AREA...BUT EVEN MEASURABLE PRECIP FROM THIS ELEMENT LOOKING
VERY UNLIKELY.
TEMP FCST WILL BE TRICKY FOR THIS AFTN WITH SOME UNCERTAINTY
REGARDING HOW MUCH LOW STRATUS WILL REMAIN IN PLACE OR THIN. 00Z
MODELS APPEAR TO BE TOO AGGRESSIVE WITH WARMING AND HAVE TRENDED
TEMPS A BIT BELOW MOS. HOWEVER...ANY LATE DAY CLEARING OR LIFTING OF
CEILINGS AS THE CENTER OF THE LOW MOVES ACROSS THE SRN PANHANDLE
WOULD SEE TEMPS APPROACH THAT PROGGED BY MOS. THIS WOULD BE MOST
LIKELY TO OCCUR ACROSS THE SWRN ZONES.
MOVING INTO TONIGHT...LESSENING RAIN CHANCES SHOULD SHIFT EAST OF
THE AREA BY EARLY EVENING. MODELS KEEP LOW LEVEL MOISTURE LEVELS
PRETTY STEADY WHILE DROPPING WINDS OFF TO BECOME VERY LIGHT. SOME
HINTING OF FOG POTENTIAL LATE TONIGHT...AND IF MORE RAIN HAD FALLEN
IN THE LAST 24 HOURS OR MORE FALLS THAN EXPECTED OVER THE NEXT
SEVERAL HOURS WOULD BE MORE INCLINED TO MENTION AREAS OF FOG IN THE
FCST. STILL A BIT TOO MUCH UNCERTAINTY HERE AND WILL LET NEXT SHIFT
REEVALUATE THAT POTENTIAL.
LONG TERM...
A RETURN TO MORE SEASONABLE TEMPS REMAINS ON TRACK BEGINNING
TOMORROW AS THE SOUTH PLAINS SHAKES THE RECENT FORAY OF MODIFIED
CANADIAN AIR. A BEVERAGE SUCH AS CANADA DRY WOULD PROVE FITTING
FOR THE NEXT SEVERAL DAYS AS TRANSIENT RIDGING ALOFT CARRIES A
DOME OF VERY MILD AND DRY AIR EAST OVER MUCH OF THE SOUTH PLAINS.
BY FRIDAY...WE SHOULD SEE A PALTRY DRYLINE EVOLVE IN THE ROLLING
PLAINS BEHIND THE DEPARTING SURFACE HIGH. QUALITY RETURN FLOW
HOWEVER IS NOT EXPECTED UNTIL SATURDAY AT WHICH POINT STRONGER
WESTERLY WINDS ALOFT BEHIND THE UPPER RIDGE WILL SHUNT MUCH OF
THIS SHALLOW MOISTURE OUT OF ALL BUT OUR FAR EASTERN COLUMN OF
COUNTIES. A MINOR SHORT WAVE TROUGH IS STILL PROGGED TO SLIDE
THROUGH THIS STRONGER WESTERLY FLOW BY SAT NIGHT/SUN MORNING
ACCOMPANIED BY PERHAPS EVEN DRIER AND WARMER CONDITIONS ON
SUNDAY...BUT WILL STICK WITH SLIGHTLY COOLER CONDITIONS AS A
COLD FRONT WILL BE FOUND EDGING PERILOUSLY CLOSE TO OUR NRN
COUNTIES IN THE WAKE OF THIS UPPER IMPULSE.
BY EARLY NEXT WEEK...NO CHANGES ARE WARRANTED ATTM AS MODELS ARE
NOW IN MORE DISAGREEMENT THAN 24 HOURS AGO. WPC CONTINUES TO FAVOR
A SLOWER AND DEEPER LONGWAVE TROUGH EVOLVING IN THE GREAT BASIN
AND FOUR CORNERS REGION BY THIS TIME. ONLY SIMILARITY AMONG THE
CURRENT ECMWF AND GFS IS THAT THIS WAVE WOULD BE OPEN AND
PROGRESSIVE...THOUGH SIGNIFICANT DIFFERENCES EMERGE IN THE TIMING
OF SAID WAVE AND HOW MUCH CP AIR IS DRAWN SOUTHWARD FOLLOWING ITS
PASSAGE. WOULD STILL EXPECT A SEMI-ACTIVE DRYLINE TO UNFOLD NEAR
THE FRINGES OF OUR EASTERN COUNTIES AS EARLY AS MON AND PERHAPS
LINGERING INTO TUE UNDERNEATH AN INCREASINGLY UNSETTLED SWLY UPPER
FLOW REGIME. THE GEFS MEAN AND EVEN THE CMC INDICATE SUCH A
SCENARIO THAT AS OF YESTERDAY WAS FAVORED BY THE ECMWF...BUT WILL
AWAIT LATER MODEL RUNS BEFORE COMMITTING TO ANY CHANGES STILL SO
MANY PERIODS OUT.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 46 32 68 43 76 / 40 10 0 0 0
TULIA 41 32 67 43 77 / 40 10 0 0 0
PLAINVIEW 41 34 68 44 77 / 30 10 0 0 0
LEVELLAND 48 34 70 46 81 / 30 10 0 0 0
LUBBOCK 43 35 70 45 79 / 30 10 0 0 0
DENVER CITY 51 34 70 47 82 / 20 10 0 0 0
BROWNFIELD 48 35 70 46 82 / 30 10 0 0 0
CHILDRESS 43 35 64 43 78 / 40 20 0 0 0
SPUR 41 35 68 45 81 / 30 10 0 0 0
ASPERMONT 43 37 66 44 80 / 30 10 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/26