Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 03/24/14
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
215 PM MST SAT MAR 22 2014
.UPDATE...UPDATED AVIATION DISCUSSION...
&&
.SYNOPSIS...
DRY WEATHER WITH ONLY PERIODIC HIGH CLOUD COVER WILL CONTINUE
THROUGH EARLY NEXT WEEK. ABOVE NORMAL TEMPERATURES WILL ALSO PREVAIL
WITH DAILY HIGHS GENERALLY FROM THE UPPER 70S TO UPPER 80S ACROSS
LOWER DESERT COMMUNITIES.
&&
.DISCUSSION.../ISSUED 140 PM 22 MARCH 2014/...
LATEST SATELLITE IMAGERY SHOWS SOME CU DEVELOPMENT ACROSS THE HIGHER
TERRAIN OF NORTHERN AZ AHEAD OF AN APPROACHING WEAK SHORT-WAVE
TROUGH. CONVECTIVE-ALLOWING MODELS INCLUDING THE HRRR REMAIN IN GOOD
AGREEMENT THAT ANY SHOWERS WILL REMAIN CONFINED TO NORTHEASTERN AZ
THIS AFTERNOON. ACROSS THE LOWER DESERTS...CLEAR SKIES CAN BE
EXPECTED OVERNIGHT WITH NEAR NORMAL TEMPERATURES.
SHORT WAVE RIDGE WILL BUILD ACROSS THE DESERT SOUTHWEST SUNDAY AHEAD
OF ANOTHER WEAK TROUGH NEAR THE CENTRAL CA COAST. SUBTLE LOW-LEVEL
WARM ADVECTION WILL YIELD AN INCREASE IN HIGH TEMPERATURES...BUT
ONLY A DEGREE OR TWO WARMER THAN THOSE OBSERVED SATURDAY.
&&
.PREVIOUS DISCUSSION...
DRY WEATHER WITH ABOVE NORMAL TEMPERATURES IN THE MID/UPPER 80S WILL
CONTINUE MONDAY AND TUESDAY. BY MID WEEK THE FLOW WILL TRANSITION TO
A MORE ZONAL REGIME AND WHILE THE GFS AND ECMWF BOTH ADVERTISE A
SHORTWAVE TROUGH TO MOVE THROUGH ARIZONA...THERE ARE TIMING/POSITION
DIFFERENCES. GFS IS A BIT SLOWER AND DEEPER WITH THE TROUGH AND
PULLS 0.6 INCH PWATS INTO THE MOUNTAINS EAST OF PHOENIX WEDNESDAY
EVENING. ECMWF SUGGESTS A SIMILAR TROUGH ABOUT 12-18HRS PRIOR
/WEDNESDAY MORNING/ BUT IS ALSO SUBSTANTIALLY DRIER. INHERITED
FORECAST HAD CLIMO-LIKE POPS EAST OF PHOENIX WEDNESDAY/WEDNESDAY
NIGHT AND THIS STILL SEEMS REASONABLE. AT THIS POINT IT LOOKS LIKE
THE DESERTS WILL REMAIN DRY /EVEN IF THE MOIST GFS SOLUTION ENDS UP
VERIFYING/. THE MAIN IMPACT WILL LIKELY BE GUSTY WINDS AHEAD OF THE
TROUGH ALONG WITH THE POTENTIAL FOR BLOWING DUST. INSERTED PATCHY
BLOWING DUST INTO THE GRIDS WEDNESDAY AFTERNOON/EVENING ALTHOUGH THE
EXACT TIMING MAY NEED TO BE ADJUSTED AS THE EVENT GETS CLOSER.
BLENDED CONSENSUS TEMPERATURE GUIDANCE SUGGESTS TEMPERATURES WILL
DROP TO AROUND NORMAL BEHIND THE TROUGH /INTO THE UPPER 70S/AROUND
80/.
OTHERWISE...RIDGING WILL RETURN IN THE WAKE OF THE TROUGH TO CLOSE
OUT THE WEEK INTO NEXT WEEKEND ALONG WITH A RETURN OF TEMPERATURES
IN THE MID/UPPER 80S.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
CLEARING SKIES FROM WEST TO EAST ACROSS THE LOWER DESERTS THIS
AFTERNOON WILL CONTINUE OVERNIGHT...WITH MID AND HIGH CIRRUS
RETURNING SUNDAY. WINDS WILL KEEP WITH DIURNAL PATTERNS AND SPEEDS
WILL REMAIN AOB 12 KTS THROUGH SUNDAY AFTERNOON.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
DRY WEST TO NORTHWEST FLOW ALOFT WILL REMAIN OVER THE AREA...WITH
WEAK WEATHER DISTURBANCES PASSING MOSTLY TO NORTH OF THE AREA
THROUGH TUESDAY. TEMPERATURES WILL REMAIN ABOVE NORMAL...WITH
MINIMUM HUMIDITIES DRYING IN TO THE SINGLE DIGITS WITH DRIER AIR
SLOWLY MOVING IN FROM THE NORTH. OVERNIGHT RECOVERIES WILL BE ON THE
GOOD SIDE UNTIL TUESDAY...WHEN THEY WILL FALL INTO THE FAIR OR POOR
RANGE...ESPECIALLY OVER THE DRIER WESTERN DESERTS. WINDS WILL FOLLOW
TYPICAL DOWN DRAINAGE/UP VALLEY PATTERNS WHILE REMAINING LIGHT
THROUGH TUESDAY. A BETTER ORGANIZED WEATHER SYSTEM WILL MOVE INTO
THE AREA BEGINNING LATE TUESDAY...SIGNIFICANTLY INCREASING WINDS FOR
WEDNESDAY. WHILE WINDS WILL BE ON THE INCREASE...DEWPOINTS ARE ALSO
FORECAST TO SEE A INCREASE AS WELL LEADING TO MORE ELEVATED DAYTIME
HUMIDITIES THAN SEEN PREVIOUSLY IN THE WEEK. WINDS MAY APPROACH
CRITICAL FIRE WEATHER THRESHOLDS WHILE THRESHOLD MEETING HUMIDITIES
MAY NOT BE REALIZED. NORTHWEST FLOW WILL LINGER OVER THE REGION FOR
THURSDAY AND FRIDAY AS DRIER AIR SLOWLY FILTERS IN FROM THE NORTH
WITH LIGHTER WINDS THAN WEDNESDAY WITH TEMPERATURES AT OR JUST ABOVE
LATE MARCH NORMALS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...LEINS
AVIATION...DEWEY
FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
140 PM MST SAT MAR 22 2014
.SYNOPSIS...
DRY WEATHER WITH ONLY PERIODIC HIGH CLOUD COVER WILL CONTINUE
THROUGH EARLY NEXT WEEK. ABOVE NORMAL TEMPERATURES WILL ALSO PREVAIL
WITH DAILY HIGHS GENERALLY FROM THE UPPER 70S TO UPPER 80S ACROSS
LOWER DESERT COMMUNITIES.
&&
.DISCUSSION...
LATEST SATELLITE IMAGERY SHOWS SOME CU DEVELOPMENT ACROSS THE HIGHER
TERRAIN OF NORTHERN AZ AHEAD OF AN APPROACHING WEAK SHORT-WAVE
TROUGH. CONVECTIVE-ALLOWING MODELS INCLUDING THE HRRR REMAIN IN GOOD
AGREEMENT THAT ANY SHOWERS WILL REMAIN CONFINED TO NORTHEASTERN AZ
THIS AFTERNOON. ACROSS THE LOWER DESERTS...CLEAR SKIES CAN BE
EXPECTED OVERNIGHT WITH NEAR NORMAL TEMPERATURES.
SHORT WAVE RIDGE WILL BUILD ACROSS THE DESERT SOUTHWEST SUNDAY AHEAD
OF ANOTHER WEAK TROUGH NEAR THE CENTRAL CA COAST. SUBTLE LOW-LEVEL
WARM ADVECTION WILL YIELD AN INCREASE IN HIGH TEMPERATURES...BUT
ONLY A DEGREE OR TWO WARMER THAN THOSE OBSERVED SATURDAY.
&&
.PREVIOUS DISCUSSION...
DRY WEATHER WITH ABOVE NORMAL TEMPERATURES IN THE MID/UPPER 80S WILL
CONTINUE MONDAY AND TUESDAY. BY MID WEEK THE FLOW WILL TRANSITION TO
A MORE ZONAL REGIME AND WHILE THE GFS AND ECMWF BOTH ADVERTISE A
SHORTWAVE TROUGH TO MOVE THROUGH ARIZONA...THERE ARE TIMING/POSITION
DIFFERENCES. GFS IS A BIT SLOWER AND DEEPER WITH THE TROUGH AND
PULLS 0.6 INCH PWATS INTO THE MOUNTAINS EAST OF PHOENIX WEDNESDAY
EVENING. ECMWF SUGGESTS A SIMILAR TROUGH ABOUT 12-18HRS PRIOR
/WEDNESDAY MORNING/ BUT IS ALSO SUBSTANTIALLY DRIER. INHERITED
FORECAST HAD CLIMO-LIKE POPS EAST OF PHOENIX WEDNESDAY/WEDNESDAY
NIGHT AND THIS STILL SEEMS REASONABLE. AT THIS POINT IT LOOKS LIKE
THE DESERTS WILL REMAIN DRY /EVEN IF THE MOIST GFS SOLUTION ENDS UP
VERIFYING/. THE MAIN IMPACT WILL LIKELY BE GUSTY WINDS AHEAD OF THE
TROUGH ALONG WITH THE POTENTIAL FOR BLOWING DUST. INSERTED PATCHY
BLOWING DUST INTO THE GRIDS WEDNESDAY AFTERNOON/EVENING ALTHOUGH THE
EXACT TIMING MAY NEED TO BE ADJUSTED AS THE EVENT GETS CLOSER.
BLENDED CONSENSUS TEMPERATURE GUIDANCE SUGGESTS TEMPERATURES WILL
DROP TO AROUND NORMAL BEHIND THE TROUGH /INTO THE UPPER 70S/AROUND
80/.
OTHERWISE...RIDGING WILL RETURN IN THE WAKE OF THE TROUGH TO CLOSE
OUT THE WEEK INTO NEXT WEEKEND ALONG WITH A RETURN OF TEMPERATURES
IN THE MID/UPPER 80S.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
DRY AND WARM SURFACE CONDITIONS TO CONTINUE WITH CIRRUS COVERAGE
INCREASING THROUGH THE DAYTIME HOURS...BECOMING SCT-BKN IN NATURE
THROUGH MIDDAY. WINDS WILL FOLLOW TYPICAL DIURNAL HEADINGS WITH
SPEEDS GNLY REMAINING AOB 12KTS THROUGH SUNDAY MORNING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
DRY WEST TO NORTHWEST FLOW ALOFT WILL REMAIN OVER THE AREA...WITH
WEAK WEATHER DISTURBANCES PASSING MOSTLY TO NORTH OF THE AREA
THROUGH TUESDAY. TEMPERATURES WILL REMAIN ABOVE NORMAL...WITH
MINIMUM HUMIDITIES DRYING IN TO THE SINGLE DIGITS WITH DRIER AIR
SLOWLY MOVING IN FROM THE NORTH. OVERNIGHT RECOVERIES WILL BE ON THE
GOOD SIDE UNTIL TUESDAY...WHEN THEY WILL FALL INTO THE FAIR OR POOR
RANGE...ESPECIALLY OVER THE DRIER WESTERN DESERTS. WINDS WILL FOLLOW
TYPICAL DOWN DRAINAGE/UP VALLEY PATTERNS WHILE REMAINING LIGHT
THROUGH TUESDAY. A BETTER ORGANIZED WEATHER SYSTEM WILL MOVE INTO
THE AREA BEGINNING LATE TUESDAY...SIGNIFICANTLY INCREASING WINDS FOR
WEDNESDAY. WHILE WINDS WILL BE ON THE INCREASE...DEWPOINTS ARE ALSO
FORECAST TO SEE A INCREASE AS WELL LEADING TO MORE ELEVATED DAYTIME
HUMIDITIES THAN SEEN PREVIOUSLY IN THE WEEK. WINDS MAY APPROACH
CRITICAL FIRE WEATHER THRESHOLDS WHILE THRESHOLD MEETING HUMIDITIES
MAY NOT BE REALIZED. NORTHWEST FLOW WILL LINGER OVER THE REGION FOR
THURSDAY AND FRIDAY AS DRIER AIR SLOWLY FILTERS IN FROM THE NORTH
WITH LIGHTER WINDS THAN WEDNESDAY WITH TEMPERATURES AT OR JUST ABOVE
LATE MARCH NORMALS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...LEINS
AVIATION...NOLTE
FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
830 PM MDT SUN MAR 23 2014
.UPDATE...
&&
.SHORT TERM...CDFNT WAS NR THE WY-NE BORDER AND WILL MOVE ACROSS
THE PLAINS OVERNIGHT. MEANWHILE A DISTURBANCE IN NW FLOW ALOFT
WILL MOVE ACROSS NERN CO BY 12Z. THIS FEATURE COULD BRING A CHC OF
LIGHT SNOW TO THE FAR NERN PLAINS LATE TONIGHT INTO MON MORNING.
.AVIATION...FNT SHOULD REACH THE AIRPORT BY 05Z IF NOT SOONER. MAY
SEE IFR CEILINGS DVLP BEHIND THE FNT AFTER 06Z HOWEVER NEITHER
HRRR OR RAP IS SHOWING ANY FOG FORMATION OVERNIGHT. THUS MAY SCALE
BACK ON FOG IN THE NEXT TAF.
&&
.PREV DISCUSSION... /ISSUED 217 PM MDT SUN MAR 23 2014/
SHORT TERM...THERE IS A DRY NORTHWEST FLOW ALOFT ACROSS COLORADO
THIS AFTERNOON WHILE MOUNTAIN TOP FLOW HAS BEEN INCREASING.
SURFACE OBSERVATIONS AND CROSS SECTIONS SHOW GUSTS UP TO 50KT
POSSIBLE OVER MOUNTAINS PASSES AND UP TO 40KT OVER EXPOSED
FOOTHILLS THROUGH THIS EVENING. SKIES HAVE BECOME MOSTLY SUNNY AT
MOST LOCALES AS THE LAST OF THE STRATUS JUST EXITING PHILLIPS AND
SEDGWICK COUNTIES AT 2 PM.
NEXT DISTURBANCE OVER THE NORTHERN ROCKY MOUNTAIN REGION WILL
BRUSH NORTHEAST COLORADO LATER TONIGHT AND MONDAY MORNING.
ASSOCIATED COLD FRONT WILL MOVE SOUTHWARD OVER THE PLAINS FROM
AROUND 04Z-10Z AS SURFACE WINDS SHIFT NORTH AND NORTHEAST. MOST OF
THIS MOISTURE IS RATHER SHALLOW SO ONLY EXPECTING STRATUS/FOG
TOWARDS THE FRONT RANGE. FURTHER NORTHEAST...WILL KEEP A SLIGHT
CHANCE OF SNOW OVER THE FAR NORTHEAST PLAINS IN VICINITY OF THE
JET STREAK AND WEAK UPWARD ASCENT NOTED IN QG FIELDS. SUNNY SKIES
WILL RETURN AGAIN FOR MONDAY AFTERNOON BUT COOLER FROM FRONTAL
PASSAGE.
LONG TERM...YET ANOTHER COLD FRONT WILL PUSH SOUTH OVER THE
PLAINS MONDAY NIGHT. FORECAST SOUNDINGS AND MOS GUIDANCE ALL
HINTING TOWARDS SOME LOW LEVEL MOISTURE LIKELY IN THE FORM OF SOME
FOG AND/OR LOW CLOUDS. DEEPER MOISTURE LOOKS TO EXIST UP TOWARD
THE NORTHEAST CORNER. HAVE ADDED PATCHY FOG AND SKY COVER OVER THE
PLAINS AND SOME LIGHT FLURRIES OVER THE NORTHEAST CORNER TO
ACCOUNT FOR THIS.
TUESDAY AND WEDNESDAY WILL FEATURE AN UPPER RIDGE MOVING OVERHEAD
FOR WARMER AND DRIER WEATHER BEFORE THE NEXT FEATURE MOVES IN
WEDNESDAY NIGHT. WEST WINDS WILL PICK UP OVER THE FORECAST AREA
WEDNESDAY...HELPING TO WARM THE PLAINS INTO THE LOW 70S. THIS DAY
MAY NEED TO BE WATCHED FOR INCREASED FIRE WEATHER CONCERNS...BUT
LOOKS MARGINAL AT THIS TIME.
A BROAD UPPER TROUGH WITH TWO DIFFERENT SHORTWAVES WILL BRING
MOISTURE TO COLORADO WEDNESDAY EVENING THROUGH FRIDAY LIKELY. SNOW
WILL PUSH INTO THE MOUNTAINS LATE WEDNESDAY AFTERNOON THEN A
CHANCE FOR RAIN AND SNOW FOR THE PLAINS AFTER MIDNIGHT. THIS
SYSTEM LOOKS SLIGHTLY MORE CONVECTIVE SO HAVE KEPT PRECIPITATION
OVER THE PLAINS AS SHOWERS. TEMPERATURES WILL BE BACK TOWARD
NORMAL FOR THIS TIME OF YEAR THURSDAY AND FRIDAY. THEN MORE
WARMING AND DRYING IS ANTICIPATED INTO THE WEEKEND AS YET ANOTHER
BROAD UPPER RIDGE MOVES OVER THE WESTERN STATES AND OVER COLORADO.
AVIATION...WEST TO NORTHWEST WINDS HAVE DEVELOPED AT LOCAL
TERMINALS AS LOW LEVELS OF THE ATMOSPHERE HAVE MIXED OUT. SHOULD
SEE A BRIEF RETURN TO MORE DRAINAGE WINDS THIS EVENING BEFORE
COLD FRONT MOVES THROUGH TERMINALS BETWEEN 07-08Z. LOW LEVEL
MOISTURE WILL INCREASE BEHIND THE FRONT WITH IFR CONDITIONS FROM
LATER TNT THROUGH MID DAY MONDAY. FOR NOW NOT EXPECTING ANY
SNOWFALL AS MOISTURE DEPTH APPEARS TO SHALLOW.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM....KRIEDERMAN
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS MIAMI FL
758 PM EDT SUN MAR 23 2014
.AVIATION...
VFR CONDITIONS ARE EXPECTED THROUGH THE OVERNIGHT HOURS AS SKIES
ARE CLEARING THIS EVENING. THERE STILL MAY BE SOME PERSISTENT
CLOUDS THROUGH THE NIGHT, BUT SHOULD NOT GO BELOW MVFR. BY
TOMORROW, A COLD FRONT WILL DRIFT SOUTHWARDS AND STALL ACROSS
SOUTH FLORIDA. THIS WILL BRING A CHANCE FOR MAINLY SHOWERS
TOMORROW. BUT, THERE IS A CHANCE THAT SOME THUNDERSTORMS MAY BE
ABLE TO FORM, ESPECIALLY IN THE AFTERNOON. THESE SHOWERS AND
THUNDERSTORMS, IF ABLE TO PASS OVER A TAF SITE, MAY TEMPORARILY
REDUCE CONDITIONS TO IFR.
WINDS ARE ANOTHER ISSUE. THEY SHOULD BECOME LIGHT TONIGHT, OUT OF
THE NORTHWEST, WITH SOME LOCATIONS BECOMING VARIABLE. AROUND
DAYBREAK, THEY WILL PICK UP OUT OF THE NORTHWEST. THEY WILL TURN
TO THE NORTHEAST BY MID DAY, THEN POSSIBLY SSE BY EARLY TO MID
AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 722 PM EDT SUN MAR 23 2014/
UPDATE...
CLOUDS WILL CONTINUE TO INCREASE IN COVERAGE ACROSS SOUTH FLORIDA
FROM NORTH TO SOUTH THROUGH THE NIGHT AS A COLD FRONT SLOWLY
INCHES CLOSER TO THE AREA. A FEW SHOWERS ASSOCIATED WITH A WEAK
SURFACE TROUGH WELL OUT AHEAD OF THE FRONT ARE EXPECTED TO LINGER
ACROSS MAINLY THE ATLANTIC WATERS THROUGH THE LATE EVENING HOURS
BEFORE DISSIPATING. UPDATED FORECAST ACCORDINGLY. KEPT PATCHY FOG
OUT OF THE FORECAST FOR THE OVERNIGHT HOURS WITH THE INCREASING
CLOUD COVER EXPECTED. REMAINDER OF THE FORECAST IS ON TRACK.
PREV DISCUSSION... /ISSUED 216 PM EDT SUN MAR 23 2014/
UPDATE...
MADE A QUICK CHANGE FOR THE AFTERNOON AND ADDED SLIGHT CHANCE OF A
SHOWER ALONG THE SOUTHEAST COAST. TEMPERATURES HAVE SOARED CLOSE
TO 90 AND A SEA BREEZE HAS DEVELOPED SLOWLY PUSHING INLAND. THE
LATEST HRRR IS NOW SHOWING A COUPLE OF LATE AFTERNOON SHOWERS
DEVELOPING ALONG THE BREEZE.
PREV DISCUSSION... /ISSUED 141 PM EDT SUN MAR 23 2014/
SHORT TERM (TONIGHT-TUESDAY NIGHT)...
SOUTH FLORIDA REMAINS UNDER THE INFLUENCE OF ZONAL FLOW ALOFT WITH
WEAK HIGH PRESSURE AT THE SURFACE. THIS TREND WILL CONTINUE
THROUGH EARLY MONDAY. A LARGE SCALE MID LEVEL TROUGH WILL DEEPEN
ACROSS EASTERN CANADA TONIGHT AND THEN INTO THE NEW ENGLAND STATES
MONDAY NIGHT AND TUESDAY. A COLD FRONT ASSOCIATED WITH THE
CANADIAN TROUGH WILL MOVE INTO NORTH FLORIDA THIS EVENING AND
SLOWLY MOVE DOWN THE PENINSULA ON MONDAY ARRIVING IN SOUTH FLORIDA
DURING THE AFTERNOON WHERE IT WILL THEN STALL. A SOUTHERN STREAM
PERTURBATION EMBEDDED IN THE ZONAL FLOW ACROSS THE NORTHERN GULF
OF MEXICO WILL AID IN MOVING THE FRONT BACK NORTH BY MONDAY
EVENING AND A SURFACE WAVE WILL DEVELOP ALONG THE BOUNDARY IN
RESPONSE TO SOUTHERN STREAM TROUGH. ALL OF THIS WILL COMBINE TO
PROVIDE DECENT VERTICAL ASCENT ACROSS THE FLORIDA PENINSULA MONDAY
NIGHT THROUGH MOST OF THE DAY ON TUESDAY FOR A CLOUDY WEATHER
PATTERN FOR SOUTH FLORIDA WITH PERIODS OF RAIN. FORECAST SOUNDINGS
SHOW PWAT INCREASING IN THE RANGE OF 1.6-1.8 INCHES IN THE TIME
PERIOD MONDAY NIGHT THROUGH TUESDAY. THIS PLACES THE PWAT AT WELL
ABOVE NORMAL AND ONLY EXCESSIVE IF THE HIGHER RANGE CAN BE
ACHIEVED. SO, RAINFALL AMOUNTS ARE NOT EXPECTED TO BE EXCESSIVE
BUT OVERALL COVERAGE WILL BE ON THE ORDER OF ONE TO TWO INCHES
WITH ISOLATED HIGHER AMOUNTS ALWAYS POSSIBLE, ESPECIALLY IF
TRAINING OF ECHOES BEGINS TO ENFOLD. THE NEW ENGLAND TROUGH WILL
CONTINUE TO DEEPEN TO THE SOUTHEAST ON MONDAY NIGHT AND TUESDAY
WHICH IN TURN WILL CAUSE THE SURFACE WAVE TO LIFT TO THE NORTHEAST
ON TUESDAY AND THE COLD FRONT WILL FINALLY PUSH THROUGH SOUTH
FLORIDA BY TUESDAY AFTERNOON AND OFF THE SOUTHEAST COAST TUESDAY
EVENING. THE SKY WILL THEN CLEAR TUESDAY NIGHT WITH COOLER
TEMPERATURES AS COOLER AND DRIER AIR FILTER DOWN THE PENINSULA
BEHIND THE FRONT.
LONG TERM (WEDNESDAY-SUNDAY)...
THE FIRST PART OF THE EXTENDED WILL BEGIN DRY AND PLEASANT WITH
TEMPERATURES ON WEDNESDAY AFTERNOON REMAINING IN THE 70S. A ZONAL
FLOW PATTERN WILL RETURN BY THURSDAY CONTINUING INTO NEXT WEEKEND.
HOWEVER, ANOTHER EMBEDDED MID LEVEL TROUGH WILL MOVE ACROSS THE
GULF OF MEXICO AND OVER SOUTH FLORIDA THURSDAY AND FRIDAY FOR
ANOTHER INCREASE IN SHOWER ACTIVITY POSSIBLY LINGERING INTO
SATURDAY BEFORE DRYING OUT AGAIN ON SUNDAY.
MARINE...
WIND AND SEAS WILL REMAIN RATHER TRANQUIL THROUGH MONDAY AS HIGH
PRESSURE DOMINATES. A COLD FRONT WILL MOVE INTO THE SOUTH FLORIDA
WATERS LATE MONDAY AND THEN RETREAT BACK TO THE NORTH MONDAY
NIGHT. A SECONDARY COLD FRONT WILL MOVE THROUGH THE LOCAL WATERS
LATE TUESDAY WITH HIGH PRESSURE BUILDING BEHIND THE FRONT. LOCAL
WIND WILL BE LIGHT AND MAINLY WESTERLY TONIGHT RAPIDLY BECOMING
LIGHT NORTHEAST ON MONDAY AS THE FRONT APPROACHES. EXTENSIVE AREAS
OF RAIN WILL DEVELOP LATE MONDAY THROUGH TUESDAY AND THEN CLEAR
OUT TUESDAY EVENING AS THE FRONT PUSHES OFF THE SOUTHEAST COAST.
WIND WILL SHIFT TO THE NORTHWEST BEHIND THE FRONT TUESDAY NIGHT
AND WEDNESDAY POSSIBLY INCREASING TO AROUND 20 KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 70 80 69 80 / 10 40 70 50
FORT LAUDERDALE 71 81 71 80 / 10 40 60 60
MIAMI 71 83 71 80 / 10 40 50 60
NAPLES 70 79 69 76 / 10 40 70 70
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...10/CD
LONG TERM....30/KOB
AVIATION...13/SI
AREA FORECAST DISCUSSION
NWS MIAMI FL
722 PM EDT SUN MAR 23 2014
.UPDATE...
CLOUDS WILL CONTINUE TO INCREASE IN COVERAGE ACROSS SOUTH FLORIDA
FROM NORTH TO SOUTH THROUGH THE NIGHT AS A COLD FRONT SLOWLY
INCHES CLOSER TO THE AREA. A FEW SHOWERS ASSOCIATED WITH A WEAK
SURFACE TROUGH WELL OUT AHEAD OF THE FRONT ARE EXPECTED TO LINGER
ACROSS MAINLY THE ATLANTIC WATERS THROUGH THE LATE EVENING HOURS
BEFORE DISSIPATING. UPDATED FORECAST ACCORDINGLY. KEPT PATCHY FOG
OUT OF THE FORECAST FOR THE OVERNIGHT HOURS WITH THE INCREASING
CLOUD COVER EXPECTED. REMAINDER OF THE FORECAST IS ON TRACK.
&&
.PREV DISCUSSION... /ISSUED 216 PM EDT SUN MAR 23 2014/
UPDATE...
MADE A QUICK CHANGE FOR THE AFTERNOON AND ADDED SLIGHT CHANCE OF A
SHOWER ALONG THE SOUTHEAST COAST. TEMPERATURES HAVE SOARED CLOSE
TO 90 AND A SEA BREEZE HAS DEVELOPED SLOWLY PUSHING INLAND. THE
LATEST HRRR IS NOW SHOWING A COUPLE OF LATE AFTERNOON SHOWERS
DEVELOPING ALONG THE BREEZE.
PREV DISCUSSION... /ISSUED 141 PM EDT SUN MAR 23 2014/
SHORT TERM (TONIGHT-TUESDAY NIGHT)...
SOUTH FLORIDA REMAINS UNDER THE INFLUENCE OF ZONAL FLOW ALOFT WITH
WEAK HIGH PRESSURE AT THE SURFACE. THIS TREND WILL CONTINUE
THROUGH EARLY MONDAY. A LARGE SCALE MID LEVEL TROUGH WILL DEEPEN
ACROSS EASTERN CANADA TONIGHT AND THEN INTO THE NEW ENGLAND STATES
MONDAY NIGHT AND TUESDAY. A COLD FRONT ASSOCIATED WITH THE
CANADIAN TROUGH WILL MOVE INTO NORTH FLORIDA THIS EVENING AND
SLOWLY MOVE DOWN THE PENINSULA ON MONDAY ARRIVING IN SOUTH FLORIDA
DURING THE AFTERNOON WHERE IT WILL THEN STALL. A SOUTHERN STREAM
PERTURBATION EMBEDDED IN THE ZONAL FLOW ACROSS THE NORTHERN GULF
OF MEXICO WILL AID IN MOVING THE FRONT BACK NORTH BY MONDAY
EVENING AND A SURFACE WAVE WILL DEVELOP ALONG THE BOUNDARY IN
RESPONSE TO SOUTHERN STREAM TROUGH. ALL OF THIS WILL COMBINE TO
PROVIDE DECENT VERTICAL ASCENT ACROSS THE FLORIDA PENINSULA MONDAY
NIGHT THROUGH MOST OF THE DAY ON TUESDAY FOR A CLOUDY WEATHER
PATTERN FOR SOUTH FLORIDA WITH PERIODS OF RAIN. FORECAST SOUNDINGS
SHOW PWAT INCREASING IN THE RANGE OF 1.6-1.8 INCHES IN THE TIME
PERIOD MONDAY NIGHT THROUGH TUESDAY. THIS PLACES THE PWAT AT WELL
ABOVE NORMAL AND ONLY EXCESSIVE IF THE HIGHER RANGE CAN BE
ACHIEVED. SO, RAINFALL AMOUNTS ARE NOT EXPECTED TO BE EXCESSIVE
BUT OVERALL COVERAGE WILL BE ON THE ORDER OF ONE TO TWO INCHES
WITH ISOLATED HIGHER AMOUNTS ALWAYS POSSIBLE, ESPECIALLY IF
TRAINING OF ECHOES BEGINS TO ENFOLD. THE NEW ENGLAND TROUGH WILL
CONTINUE TO DEEPEN TO THE SOUTHEAST ON MONDAY NIGHT AND TUESDAY
WHICH IN TURN WILL CAUSE THE SURFACE WAVE TO LIFT TO THE NORTHEAST
ON TUESDAY AND THE COLD FRONT WILL FINALLY PUSH THROUGH SOUTH
FLORIDA BY TUESDAY AFTERNOON AND OFF THE SOUTHEAST COAST TUESDAY
EVENING. THE SKY WILL THEN CLEAR TUESDAY NIGHT WITH COOLER
TEMPERATURES AS COOLER AND DRIER AIR FILTER DOWN THE PENINSULA
BEHIND THE FRONT.
LONG TERM (WEDNESDAY-SUNDAY)...
THE FIRST PART OF THE EXTENDED WILL BEGIN DRY AND PLEASANT WITH
TEMPERATURES ON WEDNESDAY AFTERNOON REMAINING IN THE 70S. A ZONAL
FLOW PATTERN WILL RETURN BY THURSDAY CONTINUING INTO NEXT WEEKEND.
HOWEVER, ANOTHER EMBEDDED MID LEVEL TROUGH WILL MOVE ACROSS THE
GULF OF MEXICO AND OVER SOUTH FLORIDA THURSDAY AND FRIDAY FOR
ANOTHER INCREASE IN SHOWER ACTIVITY POSSIBLY LINGERING INTO
SATURDAY BEFORE DRYING OUT AGAIN ON SUNDAY.
MARINE...
WIND AND SEAS WILL REMAIN RATHER TRANQUIL THROUGH MONDAY AS HIGH
PRESSURE DOMINATES. A COLD FRONT WILL MOVE INTO THE SOUTH FLORIDA
WATERS LATE MONDAY AND THEN RETREAT BACK TO THE NORTH MONDAY
NIGHT. A SECONDARY COLD FRONT WILL MOVE THROUGH THE LOCAL WATERS
LATE TUESDAY WITH HIGH PRESSURE BUILDING BEHIND THE FRONT. LOCAL
WIND WILL BE LIGHT AND MAINLY WESTERLY TONIGHT RAPIDLY BECOMING
LIGHT NORTHEAST ON MONDAY AS THE FRONT APPROACHES. EXTENSIVE AREAS
OF RAIN WILL DEVELOP LATE MONDAY THROUGH TUESDAY AND THEN CLEAR
OUT TUESDAY EVENING AS THE FRONT PUSHES OFF THE SOUTHEAST COAST.
WIND WILL SHIFT TO THE NORTHWEST BEHIND THE FRONT TUESDAY NIGHT
AND WEDNESDAY POSSIBLY INCREASING TO AROUND 20 KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 70 80 69 80 / 10 40 70 50
FORT LAUDERDALE 71 81 71 80 / 10 40 60 60
MIAMI 71 83 71 80 / 10 40 50 60
NAPLES 70 79 69 76 / 10 40 70 70
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
410 PM EDT SAT MAR 22 2014
.SYNOPSIS...
20Z WATER VAPOR AND H4 RAP ANALYSIS SHOW AN UNAMPLIFIED UPPER LEVEL
PATTERN IN PLACE ACROSS MUCH OF THE CONUS. FLOW IS VERY ZONAL IN
NATURE ALONG THE NORTHERN GULF COAST AND OVER THE FLORIDA PENINSULA.
ONE VERY WEAK IMPULSE ALOFT IS RESULTING IN A SUBTLE SURFACE TROUGH
AT THE SURFACE ACROSS THE NORTH-CENTRAL GULF. THE CONVERGENT FOCUS
ALONG THIS BOUNDARY ALONG WITH LOW LEVEL UPGLIDE ALONG THE 290-295K
SURFACES IS PROVIDING JUST ENOUGH LIFT TO SUPPORT SOME SHOWERS AND
ISOLATED STORMS TO THE WEST OF THE COASTAL WATERS EARLY THIS
EVENING. FURTHER TO THE EAST WE FIND AN AREA OF HIGH PRESSURE OVER
THE FAR EASTERN GULF OF MEXICO AND WEST COAST OF FLORIDA. THIS
PATTERN TRANSITIONS TO A WEAK INVERTED SURFACE TROUGH ALONG THE
FLORIDA EAST COAST/GULF STREAM WATERS. THIS TROUGH IS ALSO
SUPPORTING A SCATTERING OF CONVECTION OFF THE FLORIDA EAST COAST.
SO...CURRENTLY WE ARE IN THE DRY ZONE BETWEEN THE TWO TROUGHS.
VERY NICE DAY ONGOING IN THIS DRY ZONE ACROSS MUCH OF THE PENINSULA.
SCT CU FIELD IS SPREADING INLAND AHEAD OF A WELL-DEFINED SEA-BREEZE.
HOWEVER...MORE IN THE WAY OF CLOUDS WILL BE ARRIVING FROM THE WEST
THIS EVENING AHEAD OF THE SURFACE TROUGH TO OUR WEST. INLAND
TEMPERATURES HAVE RISEN INTO THE 80S...WHILE COASTAL SPOTS ARE HELD
IN THE 70S WITH THE FLOW OFF THE COOLER SHELF WATERS.
&&
.SHORT TERM (TONIGHT THROUGH MONDAY)...
TONIGHT...FORECAST DILEMMA FOR THE OVERNIGHT IS WHETHER ANY OF THE
SCT SHOWER ACTIVITY MOVING INTO THE EASTERN GULF WILL SURVIVE ALL
THE WAY TO THE NATURE COAST ZONES. PRETTY GOOD MODEL CONSENSUS THAT
THE SURFACE TROUGH WILL FADE WITH TIME INTO THE OVERNIGHT AS IT
TRIES TO MOVE EAST...AND ALLOW BOTH THE SURFACE FOCUS AND OVERLYING
UPGLIDE TO DIMINISH WITH TIME. THE ECMWF HAD BEEN MORE AGGRESSIVE
WITH THE 00Z RUN...BUT HAS BACKED OFF SIGNIFICANTLY TO MATCH MANY OF
THE OTHER MEMBERS SHOWING ONLY ISOLATED SHOWERS (IF ANYTHING)
ARRIVING AT THE NATURE COAST AFTER DARK. FOR NOW...WILL KEEP A BRIEF
WINDOW OF ISOLATED SHOWERS IN THE FORECAST LATER THIS EVENING TO THE
NORTH OF TAMPA BAY...HOWEVER THESE SHOWERS...IF THEY OCCUR...SHOULD
NOT HAVE A SIGNIFICANT IMPACT ON ANY OUTDOOR ACTIVITIES (LIKELY NOT
EVEN ENOUGH TO WET THE GROUND). LOW TEMPERATURES OVERNIGHT WILL BE
SEASONABLE WITH 50S NORTH OF TAMPA BAY AND IN GENERALLY IN THE
LOW/MID 60S FROM I-4 SOUTHWARD.
SUNDAY...
UNEVENTFUL IN TERMS OF SENSIBLE WEATHER FOR MUCH OF THE DAY ON
SUNDAY. INCREASING COLUMN MOISTURE WILL RESULT IN MORE CLOUDS THAN
ON SATURDAY...ESPECIALLY OVER THE NORTHERN HALF OF THE PENINSULA. A
WEAK COLD FRONT WILL BE APPROACHING FROM THE NORTH...AND SHOULD BE
AROUND THE I-10 CORRIDOR BY THE TIME THE SUN SETS TOMORROW EVENING.
LATE IN THE AFTERNOON/EARLY EVENING...A FEW SHOWERS SHOULD BE
ARRIVING UP OVER OUR NORTHERN NATURE COAST ZONES ALONG THIS FRONT.
HOWEVER...THE SYNOPTIC FORCING ALOFT WILL STILL BE FAIRLY WEAK...AND
THEREFORE NOT EXPECTING ANY SIGNIFICANT PRECIPITATION AND LIKELY NOT
ANY THUNDER. A FEW ISOLATED AFTERNOON SHOWERS ARE ALSO NOT OUT OF
THE QUESTION ACROSS EASTERN POLK/HIGHLANDS COUNTIES WITHIN A ZONE OF
ENHANCED LOW LEVEL CONVERGENCE BETWEEN THE FAST INLAND PROPAGATION
OF THE WEST-COAST SEA-BREEZE...AND THE MORE "PINNED TO THE COAST"
EAST-COAST SEA-BREEZE. TEMPERATURES WILL AGAIN BE WARM WITH UPPER
70S TO NEAR 80 NORTH UNDER THE GREATER AMOUNTS OF CLOUDS...TO THE
LOWER TO MIDDLE 80S SOUTH ASSOCIATED WITH MORE SUN/THINNER CLOUDS.
SIMILAR TO TODAY...A DECENT ONSHORE FLOW DURING THE AFTERNOON WILL
KEEP TEMPS SEVERAL DEGREES COOLER.
SUNDAY NIGHT/MONDAY...
WEAK COLD FRONT DROPS DOWN TO A POSITION ACROSS THE EASTERN GULF AND
CENTRAL FL PENINSULA AND BECOME QUASI-STATIONARY IN NATURE. ONCE
AGAIN...THE UPPER LEVEL SUPPORT WILL NOT BE ALL THAT
IMPRESSIVE...BUT THIS TIME...GUIDANCE IN GOOD AGREEMENT THAT THE
SURFACE FOCUS AND OVERLYING UPGLIDE REGIME WILL BE MUCH MORE
DEFINED. SHOULD SEE A FEW SCT SHOWERS SUNDAY NIGHT...MAINLY NORTH OF
I-4...AS THE FRONT SETTLES INTO ITS STATIONARY POSITION.
THEREAFTER...THE UPGLIDE WILL BECOME ESTABLISHED QUICKLY WITH THE
GFS ESPECIALLY SHOWING AN IMPRESSIVE PATTERN BETWEEN THE 290-300K
SURFACE. JUST WHERE THIS BOUNDARY SETS UP WILL BE THE FORECAST ISSUE
FOR THE BEGINNING OF THE WEEK WITH BEST RAIN CHANCES ALONG AND TO
THE NORTH. AS OF NOW...IT LOOKS LIKE MUCH OF THE REGION WILL SEE AT
LEAST SCT TO PERHAPS NUMEROUS SHOWERS/ISOLATED STORMS DEVELOPING
QUICKLY DURING THE DAY ON MONDAY AND LINGERING INTO MONDAY NIGHT.
ONE BIAS THAT MANY LARGE SCALE NWP MODELS HAVE IS TO BE A BIT SLOW
IN THE DEVELOPMENT OF QPF THAT IS FORCED PRIMARILY BY ANY UPGLIDE
REGIME. THEREFORE...ALTHOUGH THE MOST WIDESPREAD SHOWERS ARE SHOWN
TO BE MONDAY AFTERNOON...WOULD NOT BE SURPRISED TO SEE THE ACTIVITY
GOING BY THE TIME OF THE MONDAY MORNING COMMUTE.
JUST A PARAGRAPH TO THOSE WHO LIKE WATCHING THE MODELS. AN
INTERESTING SETUP IS SEEN IN MANY OF THE GLOBAL MEMBERS OFF THE
EASTERN CONUS SEABOARD TUESDAY INTO WEDNESDAY WITH REGARDS TO A
DEVELOPING AREA OF LOW PRESSURE. ANY OUTPUT FROM A MODEL IS JUST ONE
OF ANY NUMBER OF POSSIBLE SOLUTIONS...AND SHOULD NEVER BE TAKEN AT
FACE VALUE. HOWEVER...THE OPERATIONAL ECMWF AND GFS ARE SIMILAR IN
THE AMOUNT OF DEEPENING THAT OCCURS AND WITH THE SPEED OF DEEPENING.
BOTH SHOW A VERY IMPRESSIVE 45+MB OF SURFACE DEEPENING WITH A 24
HOUR PERIOD BETWEEN MIDDAY TUESDAY AND MIDDAY WEDNESDAY...WITH A
NEAR TEXTBOOK COUPLED MID/UPPER LEVEL JET STRUCTURE. DO NOT
WORRY...THIS SYSTEM WILL BE FAR PAST OUR REGION AND PULLING AWAY
QUICKLY TO THE NORTHEAST BEFORE THIS EXPLOSIVE DEEPENING WOULD
OCCUR... HOWEVER IT MAY HAVE AN IMPACT BY WEDNESDAY INTO THURSDAY OF
HELPING TO DRIVE A RATHER COOL AIRMASS FOR LATE MARCH DOWN INTO THE
FLORIDA PENINSULA. HAVE A GREAT REST OF YOUR WEEKEND!
&&
.LONG TERM (MONDAY NIGHT-SATURDAY)...
QUITE A BIT OF UNCERTAINTY CONTINUES THROUGH THE LONG TERM PERIODS
AS MODEL SOLUTIONS CONTINUE TO DEPICT A FAST WEST-EAST FLOW ALOFT
WITH NUMEROUS DIFFERENCES NOTED WITH RESPECT TO SYNOPTIC WEATHER
FEATURES. AS A RESULT...WILL TRY TO MINIMIZE FORECAST ERROR THROUGH
THE PERIOD AND TAKE A BLENDED APPROACH TO THE OVERALL FORECAST.
EARLY IN THE LONG TERM PERIOD THE MODELS ARE IN GOOD AGREEMENT
SHOWING A DECENT RAIN AFFECTING THE AREA MONDAY NIGHT INTO TUESDAY
AS A SHARP UPPER TROUGH DIGS INTO THE SOUTHEAST UNITED STATES
INDUCING STRONG CYCLOGENESIS OFF THE CAROLINA COAST. THIS WILL ALLOW
THE BOUNDARY STALLED OUT ACROSS CENTRAL FLORIDA TO SHIFT SOUTHWARD
AS A COLD FRONT...CLEARING THE FORECAST AREA BY EARLY TUESDAY
EVENING. HIGH PRESSURE IS THEN EXPECTED TO BRIEFLY BUILD BACK INTO
THE REGION TUESDAY NIGHT AND WEDNESDAY WITH A VARIETY OF MODEL
SOLUTIONS THEN SHOWING RETURN FLOW TO DIFFERING DEGREES RESULTING IN
UNSETTLED WEATHER BEGINNING AS EARLY AS WEDNESDAY NIGHT AND
CONTINUING INTERMITTENTLY THROUGH THE FIRST PART OF THE UPCOMING
WEEKEND. AS A RESULT...WILL NEED TO KEEP RAIN IN THE FORECAST FOR
EACH FORECAST PERIOD WITH THE EXCEPTION OF TUESDAY NIGHT AND
WEDNESDAY. BELOW NORMAL TEMPERATURES ARE EXPECTED TUESDAY THROUGH
THURSDAY...WITH TEMPERATURES RETURNING TO NEAR OR SLIGHTLY ABOVE
NORMAL LEVELS FOR THE END OF THE WORK WEEK AND THE FIRST HALF OF THE
UPCOMING WEEKEND.
&&
.AVIATION...
22/18Z-23/12Z: VFR THROUGH THE AFTERNOON WITH SOME BKN CIRRUS IN THE
EVENING. CAN NOT RULE OUT A STRAY SHRA BUT ODDS ARE TOO LOW TO
INCLUDE IN THE TAFS. LIMITED BR TOWARD SUNRISE WITH PREVAILING VSBY
6SM...HOWEVER LCL MVFR POSSIBLE. WEST WINDS BECOME LIGHT AND MOSTLY
VARIABLE OVERNIGHT THEN WESTERLY LATE SUN MORNING.
&&
.MARINE...
WINDS AND SEAS WILL REMAIN BELOW HEADLINE CRITERIA THROUGH SUNDAY. A
WEAK COLD FRONT WILL THEN SLIP INTO THE NORTHEAST GULF OF MEXICO
SUNDAY NIGHT AND MONDAY AND THEN STALL. SHOWERS WILL BECOME COMMON
ALONG THIS BOUNDARY THROUGH MONDAY AND MONDAY NIGHT. STRONG LOW
PRESSURE ORGANIZING OFF THE GEORGIA/CAROLINA COAST ON TUESDAY WILL
THEN HELP STRENGTHEN THIS FRONT AND ALSO PUSH IT SOUTH AND EAST
THROUGH THE FORECAST WATERS. A PERIOD OF ADVISORY LEVEL WINDS AND
SEAS IS THEN LIKELY BEHIND THIS FRONT BY TUESDAY NIGHT AND LINGERING
INTO THE DAY ON WEDNESDAY.
&&
FIRE WEATHER...
NO SIGNIFICANT FIRE WEATHER CONCERNS ARE EXPECTED THE NEXT SEVERAL
DAYS. RELATIVE HUMIDITY VALUES MAY BRIEFLY APPROACH CRITICAL LEVELS
DOWN TOWARD CHARLOTTE AND LEE COUNTIES SUNDAY AFTERNOON...HOWEVER
WINDS AND ERC VALUE WILL PREVENT RED FLAG CONDITIONS. INCREASING
MOISTURE WILL KEEP RELATIVE HUMIDITY VALUES WILL ABOVE CRITICAL
LEVELS BY MONDAY.
FOG POTENTIAL...PATCHY FOG IS POSSIBLE OVERNIGHT...BUT WIDESPREAD
DENSE FOG IS NOT EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 61 79 66 77 / 10 10 30 60
FMY 63 86 67 82 / 0 0 10 50
GIF 61 83 64 78 / 10 10 30 60
SRQ 62 79 66 77 / 0 10 20 50
BKV 56 80 62 76 / 20 10 30 60
SPG 65 80 67 77 / 10 10 30 50
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM...JELSEMA
AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
259 PM EDT SAT MAR 22 2014
.CURRENTLY...
AFTERNOON SURFACE ANALYSIS DEPICTS RIDGING MOVING EASTWARD INTO
THE ATLANTIC. A COLD FRONT WAS DRAPED FROM THE MID-ATLANTIC STATES
SOUTHWESTWARD THROUGH THE TENNESSEE AND LOWER MISSISSIPPI RIVER
VALLEYS. ALOFT...FAST ZONAL FLOW PERSISTS...WITH A RIPPLE IN THE
FLOW THIS MORNING DEPARTING INTO THE ATLANTIC WATERS...TAKING MOST
OF THE SHOWER AND EMBEDDED THUNDERSTORM ACTIVITY WITH IT. A
PRESCRIBED FIRE IN CLAY COUNTY IS THE ONLY ITEM ON THE JAX AND VAX
DOPPLER RADAR SCANS THIS AFTERNOON. PARTLY CLOUDY SKIES AND
SOUTHWEST TO WEST WINDS AROUND 10 MPH ARE BOOSTING INLAND
TEMPERATURES TO NEAR 80...WHILE A SEA BREEZE HAS COOLED
TEMPERATURES TO THE LOWER 70S ALONG THE IMMEDIATE COAST.
.NEAR TERM (TONIGHT)...
ANY ISOLATED LATE AFTERNOON SHOWERS DEVELOPING ALONG THE SEA
BREEZE WILL DEPART COASTAL SECTIONS BY SUNSET. CLEARING SKIES ARE
EXPECTED FROM WEST TO EAST TONIGHT AS A PERIOD OF SUBSIDENCE MOVES
OVERHEAD. MODEL SOUNDINGS DEPICT INCREASING WESTERLY FLOW ABOVE
850 MILLIBARS (ABOVE 5000 FT) WELL IN ADVANCE OF AN APPROACHING
COLD FRONT...WHICH MAY ADVECT SOME LOW STRATUS OR LIGHT FOG INTO
THE SUWANNEE VALLEY AND NORTH CENTRAL FL DURING THE PREDAWN HOURS.
OTHERWISE...HI-RES HRRR MODEL RUNS HAVE BEEN HINTING AT SEA FOG
DEVELOPMENT OVER THE SOUTHEAST GEORGIA COASTAL WATERS...WHERE
DEWPOINTS SHOULD REMAIN NEAR OR JUST ABOVE SHELF WATER
TEMPERATURES NEAR 60. CONFIDENCE REMAINS LOW SINCE BOUNDARY LAYER
WINDS WILL STRENGTHEN OVERNIGHT...AND THUS INDICATED ONLY PATCHY
FOG IN THE NEAR SHORE WATERS DURING THE LATE EVENING HOURS. LOWS
INLAND SHOULD FALL INTO THE LOW/MID 50S...WITH LOWS NEAR 60
EXPECTED AT THE COAST.
.SHORT TERM (SUNDAY THROUGH TUESDAY NIGHT)...
SUNDAY...LOW PRESSURE DEVELOPING ALONG THE CAROLINA COAST WILL
DRAG A COLD FRONT THROUGH THE REGION DURING THE AFTERNOON AND
EVENING HOURS WITH SCATTERED SHOWERS AND A SLIGHT CHANCE OF
THUNDERSTORMS. THUNDERSTORM ACTIVITY IS EXPECTED TO REMAIN NON-
SEVERE BUT A FEW STRONG STORMS WITH SMALL HAIL/GUSTY WINDS NOT
OUT OF THE QUESTION. BREEZY W/SW FLOW AROUND 15 MPH WILL PUSH MAX
TEMPS TO AROUND 80 DEGREES IN ALL LOCATIONS WITH SOME SPOTS
PUSHING THE MID 80S ACROSS NE FL WHERE THE SHOWERS WILL NOT MAKE
IT UNTIL LATER IN THE DAY. RAINFALL AMOUNTS WILL GENERALLY BE IN
THE TENTH TO QUARTER INCH OF RAIN.
MONDAY...MUCH COLDER AIR MASS BEHIND THE FRONT WILL HOLD TEMPS
ABOUT 20 DEGREES COLDER THAN SUNDAY IN THE LOWER 60S FROM THE I-10
CORRIDOR TO MID/UPPER 60S REST OF NE FL. BREEZY/WINDY NORTHEAST
FLOW WILL BE PRESENT ALONG THE COAST AND I-95 CORRIDOR AT 15-25
MPH WITH GUSTS AROUND 30 MPH POSSIBLE AND LAKE WIND ADVISORY CONDS
WILL BE POSSIBLE. THE NEXT LOW PRESSURE CENTER WILL DEVELOP ON THE
FRONTAL BOUNDARY SOUTH OF THE REGION AND EXPECT RAINFALL TO RE-
DEVELOP DURING THE AFTERNOON HOURS WITH NUMEROUS SHOWERS AND
SLIGHT CHANCE OF THUNDERSTORMS POSSIBLE THROUGH MONDAY NIGHT.
RAINFALL AMOUNTS WILL BE A BIT HIGHER WITH THIS EVENT AND EXPECT
AN ADDITIONAL ONE HALF INCH IN MOST LOCATIONS BY TUESDAY MORNING
WITH ISOLATED HIGHER TOTALS AROUND ONE INCH.
TUESDAY...RAINFALL ENDS FROM WEST TO EAST DURING THE MORNING HOURS
AS LOW PRESSURE QUICKLY PULLS AWAY TO THE NORTHEAST. EXPECT SUNNY,
WINDY AND COOL CONDITIONS BY THE AFTERNOON HOURS AS NORTHWEST
WINDS INCREASE TO 15-25 MPH WITH GUSTS AROUND 30 MPH POSSIBLE. MAX
TEMPS WILL TOP OUT ONCE AGAIN MAINLY IN THE 60S AND LOWER 70S WITH
THE SUNSHINE ABLE TO PUSH THEM SLIGHTLY HIGHER THAN MONDAY`S
READINGS.
.LONG TERM (TUESDAY NIGHT THROUGH SATURDAY)...
TUE NIGHT/WED...UNSEASONABLY COOL HIGH PRESSURE BUILDS INTO THE
REGION AND WILL PROVIDE FOR MOSTLY CLEAR SKIES AND LOWS DOWN INTO
THE 30S OVER INLAND AREAS AND 40S ALONG THE COAST AND ST JOHNS
RIVER BASIN. WINDS LIKELY TO REMAIN TOO ELEVATED TO PRODUCE MUCH
CHANCE FOR FROST OVER INLAND AREAS EARLY WED MORNING. HIGHS WILL
REMAIN MUCH COOLER THAN NORMAL IN THE LOWER TO MIDDLE 60S
WEDNESDAY AFTERNOON.
THU-SAT...LONG RANGE MODELS STILL SHOW HIGH PRESSURE DEPARTING TO
THE EAST ON THURSDAY AND STRONG MID/UPPER LEVEL DISTURBANCE
TRACKING INTO THE FLORIDA PENINSULA IN THE FRI/SAT TIME FRAME..SO
EXPECT A CHANCE OF PRECIP IN THE TIME FRAME...ALTHOUGH EXACT
TIMING STILL IN QUESTION. MODELS SHOWING DECENT RAINFALL TOTALS OF
1-2 INCHES POSSIBLE ACROSS THE FLORIDA PENINSULA WITH THIS NEXT
EVENT BUT STILL TOO FAR OUT TO DETERMINE ANY SIGNIFICANT IMPACTS.
TEMPERATURES WILL REBOUND CLOSER TO SEASONABLE VALUES IN THIS TIME
FRAME.
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGH AT LEAST 03Z...WITH EARLY
AFTERNOON CIGS AROUND 3500 FT LIFTING AND DISSIPATING TOWARDS
SUNSET. SEA FOG DEVELOPING OVER THE NEAR SHORE SOUTHEAST GEORGIA
COASTAL WATERS THIS EVENING MAY BRIEFLY PRODUCE MVFR VISIBILITIES
AT SSI AFTER 03Z. MVFR VISIBILITIES ARE ALSO EXPECTED TO DEVELOP
AT GNV AND VQQ AFTER 08Z. A COLD FRONT APPROACHING OUR REGION FROM
THE NORTHWEST ON SUN MAY BRING SCATTERED SHOWERS TO THE TERMINALS
AFTER 18Z. SURFACE WINDS WILL REMAIN NEAR 10 KTS THROUGH
SUNSET...WITH SPEEDS SUBSIDING THIS EVENING. WESTERLY WINDS WILL
INCREASE ABOVE 2000 FT AFTER 12Z SUN.
&&
.MARINE...
SOUTH TO SOUTHWEST WINDS JUST BELOW CAUTION SPEEDS ARE EXPECTED
IN THE OFFSHORE WATERS THROUGH EARLY SUNDAY. ON SUNDAY A GENERAL
WESTERLY FLOW AT 10-15 KNOTS AND SEAS 2-4 FT WILL LINGER INTO
THE EVENING HOURS THEN STRONG NORTH SURGE DEVELOPS AFTER MIDNIGHT
BECOMING NORTHEAST ON MONDAY AT 20-25 KNOTS WITH GUSTS IN THE
30-35 KNOT RANGE. NOT LIKELY STRONG ENOUGH FOR A GALE WARNING BUT
SMALL CRAFT ADVISORIES ARE EXPECTED LATE IN THE 3RD PERIOD SO WILL
LET MID SHIFT TAKE ONE FINAL LOOK AT EVENT BEFORE KICKING OUT
HEADLINE PRODUCTS. SURGE FADES SLOWLY MONDAY NIGHT AS LOW PRESSURE
TRACKS ACROSS THE WATERS...THEN SWITCHES SHARPLY TO NORTHWEST AT
20-25 KNOTS TUESDAY INTO TUESDAY NIGHT BEHIND DEPARTING LOW
PRESSURE CENTER. SEAS GENERALLY BUILDING INTO THE 6-9 FT RANGE BY
MONDAY AND CONTINUING ELEVATED IN THE OFFSHORE WATERS IN THE
NORTHWEST FLOW EVENT ON TUESDAY INTO WEDNESDAY.
THE NORTHEAST FLOW EVENT ON MONDAY WILL SEND TIDAL DEPARTURES/STORM
SURGE VALUES OF AT LEAST ONE FOOT ABOVE NORMAL INTO THE SE GA/NE
FL COAST BUT TIMING WITH A LAST QUARTER MOON WILL ALLOW FOR TIDAL
VALUES TO REMAIN BELOW ANY MINOR COASTAL FLOODING VALUES. BREAKERS
IN THE SURF ZONE ARE EXPECTED TO INCREASE TO 4-6 FT ON MONDAY WITH
A SOLID MODERATE RISK OF RIP CURRENTS EXPECTED.
RIP CURRENTS: LINGERING LONG PERIOD EASTERLY SWELLS WILL PERSIST
THROUGH THIS EVENING...CREATING A MODERATE RISK OF RIP CURRENTS AT
AREA BEACHES. A LOW RISK IS ANTICIPATED ON SUN.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 80 52 79 47 / 10 10 40 40
SSI 74 58 78 53 / 30 20 30 30
JAX 80 56 81 54 / 20 10 40 40
SGJ 77 58 79 58 / 20 10 30 30
GNV 79 53 81 57 / 10 0 30 30
OCF 82 54 82 59 / 0 0 20 30
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
NELSON/HESS/WALKER
AREA FORECAST DISCUSSION...UPDATED
NWS MELBOURNE FL
1025 AM EDT SAT MAR 22 2014
.DISCUSSION...
...A HIGH RISK OF RIP CURRENTS AT THE COAST...
...ISOLATED AFTERNOON STORMS...
MORNING SOUNDINGS FROM THE FL PENINSULA SHOW INCREASED SOUTHERLY
FLOW HAS OCCURRED AND MOISTENED THE LOW LEVELS IN THE LAST 12-24
HOURS. A MID LEVEL DISTURBANCE IS PUSHING EAST ACROSS THE GULF COAST
AND THIS WILL INDUCE WEAK SFC LOW DEVELOPMENT NEAR JAX LATE IN THE
DAY. SOUTH BREEZE THIS MORNING WILL TURN SW THIS AFTERNOON...EXCEPT
ALONG THE COAST WHERE A SE SEA BREEZE SHOULD DEVELOP BUT REMAIN
CLOSE TO THE COAST.
THE BEST CHANCE FOR SHOWERS AND ISOLATED STORMS WILL BE ALONG THE
COAST FROM BREVARD TO MARTIN COUNTIES WHERE THE SEA BREEZE PROVIDES
SOME LIFT. HAVE LOWERED POPS SLIGHTLY OVER THE NORTH INTERIOR BUT
WILL MAINTAIN A SLIGHT CHANCE FOR SHOWERS THROUGH THE DAY AS MAX
TEMPS REACH THE MID 80S.
500MB TEMPS ARE COLD...-12C AT CAPE AND -13C AT TBW...WARMING TO
-10C AT MIA. LOW LEVEL MOISTURE THOUGH IS HIGHER TO THE SOUTH SO THE
COLDEST TEMPS ARE NOT OVERLAID WITH THE BEST LL MOISTURE.
STILL...ONE OR TWO STRONG STORMS WILL BE POSSIBLE NEAR THE COAST
CONTAINING GUSTY WINDS AND SMALL HAIL. SEVERE WEATHER IS NOT
ANTICIPATED. IT SHOULD BE NOTED THAT THE HRRR AND LOCAL WRF_ARW
MODELS KEEP THE BULK OF THE CONVECTION JUST OFFSHORE IN THE ATLC
THIS AFTERNOON.
BASED ON MORNING REPORTS FROM BEACH PATROLS...WILL CONTINUE THE HIGH
RISK OF RIP CURRENTS AT THE BEACHES.
&&
.AVIATION...
MAINLY VFR. BEST CHANCE FOR SHRA/ISOLD TSRA WILL BE COASTAL
TERMINALS FROM TIX SOUTHWARD WHICH COULD PRODUCE BRIEF MVFR CONDS.
CURRENT THINKING IS ALL ACTIVITY WILL PUSH OFFSHORE BY 00Z WITH A
LIGHT WEST WIND OVERNIGHT.
&&
.MARINE...
PRIMARY WAVE COMPONENT CONTINUES TO BE LONG PERIOD (11-12 SEC) E/NE
SWELL AROUND 3 FT. SOUTHERLY FLOW WILL ADD A CHOPPY (4-5 SEC) WIND
WAVE. SOUTH WINDS WILL INCREASE THIS AFTN INTO THIS EVE...REACHING
15-20 KNOTS OFFSHORE AS WEAK LOW PRESSURE DEVELOPS NEAR JAX. WILL
MAINTAIN SMALL CRAFT CAUTION HEADLINE FOR THE OFFSHORE WATERS. A FEW
STORMS MAY PUSH OFFSHORE SOUTH OF THE CAPE THIS AFTN. OTHERWISE THE
CONVECTION OVER THE ATLC THIS MORNING WILL LIFT N/NE AND STAY OVER
THE OPEN WATERS. WINDS WILL TURN W/NW TONIGHT AND DECREASE AS LOW
PRESSURE PULLS AWAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 81 60 81 63 / 30 20 20 20
MCO 84 61 85 65 / 20 10 10 20
MLB 82 63 83 64 / 30 20 10 10
VRB 81 62 84 64 / 30 20 10 10
LEE 83 60 84 63 / 20 10 20 20
SFB 83 60 84 65 / 30 10 20 20
ORL 83 63 84 65 / 20 10 10 20
FPR 82 61 84 65 / 30 20 10 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
KELLY/SPRATT
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS JACKSONVILLE FL
440 AM EDT SAT MAR 22 2014
.SHORT TERM...TODAY AND TONIGHT...WEAK IMPULSE EMBEDDED IN ZONAL
FLOW ALOFT WILL BRING A CHANCE OF RAIN THIS MORNING. ALL MODELS SHOW
RAIN BREAKING OUT BY 12Z OVER MAINLY THE EASTERN HALF OF THE AREA
AND THEN DECREASING AFTER 18Z AS IMPULSE MOVES INTO THE ATLANTIC.
MID CLOUDS NOW EXPANDING OVER CENTRAL FL AS INCREASING ISENTROPIC
LIFT BRINGS MOISTURE NORTHWARD. MODELS SHOW WEAK ELEVATED
INSTABILITY DEVELOPING AS MID LEVELS COOL WITH IMPULSE. HRRR MODEL
HAS MUCAPE OF 500+ J/KG SO WILL KEEP MENTION OF ISOLATED THUNDER.
HIGH TEMPERATURES TODAY WILL RANGE FROM THE LOW TO MID 70S NEAR THE
COAST TO THE UPPER 70S/LOW 80S INLAND.
SUNDAY THROUGH TUESDAY...
A COLD FRONT WILL ENTER SE GA SUNDAY MORNING...MOVING SOUTH TO
EXTREME NORTHERN FL SUNDAY EVENING...AND SOUTH INTO CENTRAL
FLORIDA SUNDAY NIGHT. A MID LEVEL SHORTWAVE AHEAD OF THE SURFACE
BOUNDARY WILL PROVIDE ENOUGH LIFT/MOISTURE FOR SOME SHOWERS AREA
WIDE BY SUNDAY AFTN/EVENING. WITH A DEEP TAP OF TROPICAL
MOISTURE LACKING...WILL KEEP POPS IN THE CHANCE CATEGORY. SUFFICIENT
INSTABILITY WILL BE PRESENT SUNDAY AFTN INTO EVENING FOR A SLIGHT
CHANCE OF TSTMS. DEEP LAYER SHEAR WILL INCREASE WITH THE FRONTAL
APPROACH SUNDAY AFTN...WITH AN ISOLATED STRONGER STORM POSSIBLE
ESPECIALLY NORTH OF THE I-10 CORRIDOR. FOR LATE SUNDAY NIGHT AND
MONDAY...MODELS DIVERGE QUITE A BIT ON HANDLING WAVES RIDING NORTH
OF THE FRONTAL BOUNDARY...WITH THE ECMWF REMAINING THE FURTHEST
NORTH AND RICHEST IN MOISTURE...WITH THE NAM NEARLY PRECIP FREE. THE
GFS IS A LITTLE FURTHER SOUTH THAN THE ECMWF BUT MORE MOIST THAN THE
VERY DRY NAM. WILL USE A ECMWF/GFS BLEND...WITH SOME PRECIP WORKING
BACK TO THE NORTH BY MONDAY AFTN...WITH NUMEROUS SHOWERS FOR MOST OF
NE FL MONDAY NIGHT INTO TUESDAY. WILL NOT DRY OUT SE GA
TOTALLY...BUT ALL MODELS POINT TO SIGNIFICANTLY LESS PRECIP
COVERAGE THERE...THUS WILL USE MID END CHANCE POPS. THE KICKER
UPPER LOW WILL MOVE ACROSS THE MID ATLANTIC TUESDAY PUSHING THE
PRECIP OUT OF THE REGION TUESDAY AFTN. WARM TEMPERATURES WILL PREVAIL
AHEAD OF THE COLD FRONT SUNDAY...WITH HIGHS IN THE UPPER 70S TO
LOWER 80S. A SIGNIFICANT COOLDOWN IS IN STORE MONDAY/TUESDAY BEHIND
THE COLD FRONT AND WITH SIGNIFICANT CLOUD COVER...WITH HIGHS EACH
DAY MAINLY IN THE 60S. BREEZY CONDITIONS CAN BE EXPECTED MONDAY
AND TUESDAY.
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
DRY BUT COOL CONDITIONS WILL PREVAIL TUESDAY NIGHT THROUGH THURSDAY
UNDER HIGH PRESSURE. A WARMING TREND WILL DEVELOP LATE WEEK AS THE
FLOW TURNS AROUND TO THE S/SE. A FRONTAL BOUNDARY WILL BEGIN TO MAKE
AN APPROACH FRIDAY...BUT WITH THE BOUNDARY LIKELY WELL TO THE WEST
WILL KEEP CONDITIONS MAINLY DRY.
.AVIATION...
VFR WILL GENERALLY PREVAIL FOR THE NEXT 24 HOURS. PATCHY BR WILL
BE POSSIBLE AT VQQ/GNV 10-12Z...WITH LOCAL MVFR NEAR SHOWERS THIS
MORNING. WILL USE VCSH WITH PREVAILING LOW END VFR CIGS FOR THE
SHOWERS FOR JAX/CRG/VQQ/SSI FROM 12-18Z. WITH WINDS JUST ABOVE THE
SURFACE TO 35 KT...WILL USE LLWS FOR ALL BUT SSI THROUGH THE EARLY
MORNING HOURS.
&&
.MARINE...HIGH PRESSURE TO THE EAST WILL RESULT IN SE WINDS TODAY AT
10-15 KNOTS. COMBINED SEAS WILL BE 2 NEAR SHORE AND UP TO 4 FEET
OFFSHORE... WITH AN EASTERLY SWELL PERSISTING. SCATTERED SHOWERS
WITH ISOLATED THUNDER POSSIBLE OVER THE WATERS THIS MORNING UNTIL
MID-AFTERNOON DUE TO UPPER DISTURBANCE MOVING EAST ACROSS THE AREA.
BENIGN WIND CONDITIONS WILL PREVAIL OVER THE WATERS SUNDAY.
NORTHERLY WINDS WILL INCREASE SUNDAY NIGHT IN THE WAKE OF A COLD
FRONT...WITH SCA LIKELY MONDAY. AS SURFACE LOW PRESSURE INTENSIFIES
RAPIDLY ACROSS THE MID ATLANTIC BY MIDWEEK...WINDS WILL INCREASE
FURTHER...WITH HIGH END SCA LIKELY LATER TUESDAY INTO WEDNESDAY.
RIP CURRENTS: MODERATE RISK TODAY DUE TO LINGERING LONG PERIOD
EASTERLY SWELLS. LOW RISK EXPECTED FOR SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 81 53 77 48 / 20 10 40 40
SSI 71 57 73 51 / 40 10 40 40
JAX 78 56 80 54 / 30 10 40 40
SGJ 76 58 75 57 / 40 10 30 30
GNV 79 56 78 56 / 20 10 40 40
OCF 81 55 81 58 / 10 10 40 40
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
ZIBURA/ALLEN/
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
345 AM EDT SAT MAR 22 2014
.DISCUSSION...
...A HIGH HAZARD OF RIP CURRENTS AT THE COAST...
...ISOLATED AFTERNOON STORMS...
DEEP SLY COMPONENT FLOW HAS INCREASED MOISTURE OVER THE PAST 24H
AND SHOWERS CONFINED EARLIER TO THE MARINE AREA HAVE BEGUN TO
DEVELOP OVER LAND DESPITE THE DIURNAL CONVECTIVE MINIMUM ATTM. IT
APPEARS SHOWERS ALONG AND NORTH OF I-4 ARE ASCD WITH SOME WEAK
ISENTROPIC LIFT AND DESTABILIZATION ALOFT ASCD WITH AN APPROACHING
UPPER DISTURBANCE. RUC INITIALIZED TEMPS @H5 ARE AROUND 12.5-13C
EARLY THIS AM.
THE FORECAST WL BEGIN WITH A SLIGHT CHC OF SHOWERS FOR ALL AREAS
AS THE APCHG UPPER WAVE WL ACT TO FURTHER DESTABILIZE THE ENVIRONMENT.
SOME BREAKS IN CLOUDINESS COUPLED WITH THE LINGERING COOL POCKET
ALOFT WL FORCE ISOLD/SCATTERED SHOWERS ALONG WITH SOME EMBEDDED AFTN
STORMS. GIVEN WLY STEERING LEVEL WINDS AND A POTENTIAL FOR COASTAL
CONVERGENCE IN THE LL ENVIRONMENTAL FLOW (PSEUDO SEABREEZE
TENDENCY) HAVE EXPANDED THE THUNDER COVERAGE NORTH ALONG ALL THE
COASTAL COS DURING THE AFTN. A EAST COAST BREEZE LOOKS TO BE BEST
DEFINED HOWEVER WHERE SLIGHTLY LOWER COUNTERING WLYS EXIST
ROUGHLY SOUTH OF SEBASTIAN INLET. THE MAIN CONV HAZARD WL BE
LIGHTNING...SMALL HAIL AND SFC WIND GUSTS TO 45 TO 50 MPH.
THIS EVENING...PASSING UPPER WAVE WL BE RESPONSIBLE FOR A
LINGERING CHC OF PCPN IN THE EVENING WITH THE THREAT OF A STORM
SHIFTING OFFSHORE THE ATLC WATERS FROM THE COAST IN THE EVENING.
EXPECT MILD TEMPERATURES IN THE LOWER 60S WITH LINGERING SCATTERED
TO BROKEN CLOUDINESS AND LIGHTENING WINDS.
SUNDAY...SUNDAY WILL BE THE DAY IN BETWEEN SYSTEMS AS WEAK FRONT
FROM SAT EXITS THE STATE AND LOW LEVEL WESTERLY FLOW INCREASES AHEAD
OF ANOTHER FRONT DROPPING THROUGH GA. MODELS SHOW WHAT REMAINING
MOISTURE THAT IS LEFT FROM SAT`S FRONT BEING PUSHED EAST WITH MID
LEVEL DRYING.
MID AND UPPER LEVEL CLOUDINESS WILL INCREASE IN THE AFTERNOON ACROSS
CENTRAL/NRN SECTIONS WITH A SLIGHT CHANCE FOR SHOWERS LATE IN THE
DAY. DO NOT THINK THERE WILL BE MUCH CONVECTION ACROSS SOUTHERN
SECTIONS WITH SEA BREEZE PINNED NEAR THE COAST DUE TO RELATIVELY DRY
AIRMASS LINGERING...BUT A BRIEF SHOWER OR TWO MAY POP UP RIGHT ALONG
THE SEA BREEZE. IT WILL BE A WARM DAY WITH HIGHS RANGING FROM AROUND
80 ALONG THE VOLUSIA COAST...LOW 80S ALONG THE REMAINDER OF THE
COST...TO MID-UPPER 80S OVER THE INTERIOR.
MON-TUES...SECOND FRONTAL BOUNDARY DROPS INTO FLORIDA LATE SUN
NIGHT/EARLY MONDAY BEFORE STALLING OUT ACROSS THE STATE BY LATE
MORNING. BRIEF PUSH OF NORTH-NORTHEASTERLY FLOW BEHIND THE BOUNDARY
DURING THE DAY BEFORE WINDS BECOME EAST AND EVENTUALLY SOUTHWEST AS
LOW PRESSURE DEVELOPS ALONG THE BOUNDARY AND LIFTS OFF TO THE
NORTHEAST AROUND DAYBREAK TUESDAY.
OVERALL MONDAY WILL BE A CLOUDY DAY WITH SCATTERED SHOWERS...FIRST
PUSHING INLAND ALONG THE VOLUSIA COAST WITH THE NE WIND SHIFT AND
THEN INTO THE SOUTHERN INTERIOR AROUND LAKE OKEECHOBEE INTO THE
AFTERNOON. HIGHS ON MON IN THE MID-UPPER 70S WITH LOWER 70S ALONG
THE VOLUSIA/NORTH BREVARD COAST AND A FEW LOW 80S AROUND LAKE
OKEECHOBEE.
BEST RAIN CHANCES (AROUND 60 PERCENT) WILL BE OVERNIGHT MONDAY AS
THE LOW TAKES SHAPE AND THERE IS SOME UPPER LEVEL SUPPORT FROM AN
EDDY SWINGING AROUND THE MAIN TROUGH FURTHER NORTH AS WELL AS THE
JET. THE DEVELOPING LOW QUICKLY LIFTS OFF TO THE NORTHEAST DURING
THE DAY ON TUESDAY AS THE DRIVING UPPER LEVEL SHORTWAVE SWINGS
THROUGH THE EAST COAST. THE GFS STILL REMAINS A LITTLE FASTER THAN
THE ECMWF...BUT ANY LINGERING RAIN WILL BE RAPIDLY OUT OF THE AREA
BY LATE EVENING.
HIGH TEMPS ON TUES WILL BE HIGHLY DEPENDENT ON THE FRONT...BUT
GENERALLY LOOKING AT MID-UPPER 70S ACROSS THE NORTH AND LOWER 80S
ACROSS THE SOUTH.
WED-FRI...DRY NORTHERLY FLOW FILTERS IN BEHIND FRONT ON WEDNESDAY AS
A LARGE HIGH MOVES OUT OF THE MIDWEST TOWARDS THE EAST COAST AND
OFFSHORE ON THURSDAY. AN PERIOD OF BREEZY ONSHORE FLOW IS EXPECTED
THROUGH THE END OF THE WEEK...WITH A RETURN OF SHOWERS TO THE
FORECAST BY THURS NIGHT/FRI AT ANOTHER TROUGH/WEAK LOW SETTING UP
OVER THE PENINSULA.
WEDNESDAY WILL SEEM RATHER COOL WITH HIGHS RANGING FROM THE MID 60S
ALONG THE VOLUSIA COAST TO LOW 70S ACROSS THE SOUTH. THE COOLEST
NIGHT WILL BE WED NIGHT WITH SOME LOWS IN THE MID TO UPR 40S ACROSS
NRN INTERIOR SECTIONS. THE SFC HIGH WILL PUSH OFF INTO THE ATLC BY
THU WITH ONSHORE FLOW DEVELOPING AND SLOWLY MODERATING TEMPERATURES.
&&
.AVIATION...
PRIMARILY VFR WITH SOME MORNING INTERSPERSED -SHRA MLNY ALG AND N
OF A LINE FM ISM-COF AND LCL MVFR CONDS ASCD WITH CIG AND LIGHT
SHRA. SHRA INCREASING IN CVG AFT 16Z WITH ISOLD TS MNLY AT THE
COASTAL SITES AND BRIEFLY IFR CIGS IN RAIN AFFECTED AREAS FM 17Z-
23Z. ISOLD TS PSBL THROUGH AROUND 02-03Z ALONG THE COAST.
&&
.MARINE...
TODAY AND TONIGHT...PRIMARY WV COMPONENT CONTINUES TO BE LONG PERIOD SWELL
WITH 12-13 SEC PERIOD REGISTERING AT MARINE SITES. SEA HGHTS FOR
NAVIGATION WL SEE SOME ADDED WIND CHOP AROUND 1-2 FT OVER THE OPEN
WATERS WITH NO FETCH LIMITATION. HEADLINES WILL NOT BE
REQUIRED...HOWEVER MARINERS SHOULD WATCH THE SOUTH AND WEST FOR
ANY APCHG STORMS THIS AFTERNOON AND INTO THE EVENING.
SUN...LIGHT WESTERLY FLOW IS EXPECTED WITH A SEA BREEZE DEVELOPING
NEAR THE COAST IN THE AFTERNOON. WINDS 10KTS OR LESS DURING THE DAY.
PASSAGE OF WEAK BOUNDARY IN THE EVENING WILL BRING AN INCREASE IN
NORTH WINDS TO 15-20KTS NORTH OF THE CAPE BY DAYBREAK MON WITH
10-15KTS WEST-NORTHWEST FURTHER SOUTH. SEAS 2-3 FT.
MON-TUES...N-NE 15-20KTS WILL BE ONGOING EARLY MONDAY ACROSS THE NRN
WATERS WITH AROUND 15KTS FURTHER SOUTH. FLOW WILL VEER QUICKLY
THROUGH MONDAY NIGHT AS LOW PRESSURE DEVELOPS ALONG STALLED FRONT
AND QUICKLY LIFTS OFF TO THE NORTHEAST OF THE STATE BY TUES MORNING.
GRADIENT AROUND THE LOW WILL BRING WEST WINDS 15-20KTS BY LATE
MORNING WITH A STRONGER COLD FRONTAL PASSAGE IN THE AFTERNOON
BRINGING NORTHWEST WINDS 20-25KTS TUES EVENING THROUGH WED
AFTERNOON.
SEAS INCREASING TO 6-7FT OFFSHORE BY LATE MONDAY NIGHT WITH UP TO
8FT NORTH OF THE CAPE. POST-FRONTAL NW WIND SURGE WILL BRING SEAS UP
TO 7-9FT OFFSHORE BY WED...WITH 4-6FT CLOSER TO THE COAST DUE TO THE
OFFSHORE COMPONENT.
&&
.FIRE WEATHER...
MIN RHS WILL DROP TO AROUND 40 PERCENT ACROSS THE INTERIOR TODAY
AND SUN AFTERNOONS WITH LOW CHANCES FOR AFTERNOON CONVECTION.
INCREASING WESTERLY FLOW SUNDAY AFTERNOON ALOFT WILL BRING
EXCELLENT DISPERSIONS SUN AFTERNOON AS TRANSPORT WINDS PICK UP TO
AROUND 20 TO 25 MPH.
RAIN CHANCES WILL INCREASE LATE MONDAY AND TUESDAY AS PREFRONTAL
MOISTURE MOVES ACROSS CENTRAL FL FOLLOWED BY A STRONGER COLD FRONT
THAT MOVES THROUGH THE AREA BY TUESDAY AFTERNOON. CRITICALLY LOW RH
AND BREEZY NW WINDS EXPECTED ON WEDNESDAY OF NEXT WEEK BEHIND THE
FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 81 60 81 63 / 30 20 20 20
MCO 84 61 85 65 / 20 10 10 20
MLB 82 63 83 64 / 30 20 10 10
VRB 81 62 84 64 / 30 20 10 10
LEE 83 60 84 63 / 20 10 20 20
SFB 83 60 84 65 / 30 10 20 20
ORL 83 63 84 65 / 20 10 10 20
FPR 82 61 84 65 / 30 20 10 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...PENDERGRAST
LONG TERM....MOSES
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
209 AM EDT SAT MAR 22 2014
.SHORT TERM...TODAY AND TONIGHT...WEAK IMPULSE EMBEDDED IN ZONAL
FLOW ALOFT WILL BRING A CHANCE OF RAIN THIS MORNING. ALL MODELS SHOW
RAIN BREAKING OUT BY 12Z OVER MAINLY THE EASTERN HALF OF THE AREA
AND THEN DECREASING AFTER 18Z AS IMPULSE MOVES INTO THE ATLANTIC.
MID CLOUDS NOW EXPANDING OVER CENTRAL FL AS INCREASING ISENTROPIC
LIFT BRINGS MOISTURE NORTHWARD. MODELS SHOW WEAK ELEVATED
INSTABILITY DEVELOPING AS MID LEVELS COOL WITH IMPULSE. HRRR MODEL
HAS MUCAPE OF 500+ J/KG SO WILL KEEP MENTION OF ISOLATED THUNDER.
HIGH TEMPERATURES TODAY WILL RANGE FROM THE LOW TO MID 70S NEAR THE
COAST TO THE UPPER 70S/LOW 80S INLAND.
SUNDAY THROUGH TUESDAY...
A COLD FRONT WILL ENTER SE GA SUNDAY MORNING...MOVING SOUTH TO
EXTREME NORTHERN FL SUNDAY EVENING...AND SOUTH INTO CENTRAL
FLORIDA SUNDAY NIGHT. A MID LEVEL SHORTWAVE AHEAD OF THE SURFACE
BOUNDARY WILL PROVIDE ENOUGH LIFT/MOISTURE FOR SOME SHOWERS AREA
WIDE BY SUNDAY AFTN/EVENING. WITH A DEEP TAP OF TROPICAL
MOISTURE LACKING...WILL KEEP POPS IN THE CHANCE CATEGORY. SUFFICIENT
INSTABILITY WILL BE PRESENT SUNDAY AFTN INTO EVENING FOR A SLIGHT
CHANCE OF TSTMS. DEEP LAYER SHEAR WILL INCREASE WITH THE FRONTAL
APPROACH SUNDAY AFTN...WITH AN ISOLATED STRONGER STORM POSSIBLE
ESPECIALLY NORTH OF THE I-10 CORRIDOR. FOR LATE SUNDAY NIGHT AND
MONDAY...MODELS DIVERGE QUITE A BIT ON HANDLING WAVES RIDING NORTH
OF THE FRONTAL BOUNDARY...WITH THE ECMWF REMAINING THE FURTHEST
NORTH AND RICHEST IN MOISTURE...WITH THE NAM NEARLY PRECIP FREE. THE
GFS IS A LITTLE FURTHER SOUTH THAN THE ECMWF BUT MORE MOIST THAN THE
VERY DRY NAM. WILL USE A ECMWF/GFS BLEND...WITH SOME PRECIP WORKING
BACK TO THE NORTH BY MONDAY AFTN...WITH NUMEROUS SHOWERS FOR MOST OF
NE FL MONDAY NIGHT INTO TUESDAY. WILL NOT DRY OUT SE GA
TOTALLY...BUT ALL MODELS POINT TO SIGNIFICANTLY LESS PRECIP
COVERAGE THERE...THUS WILL USE MID END CHANCE POPS. THE KICKER
UPPER LOW WILL MOVE ACROSS THE MID ATLANTIC TUESDAY PUSHING THE
PRECIP OUT OF THE REGION TUESDAY AFTN. WARM TEMPERATURES WILL PREVAIL
AHEAD OF THE COLD FRONT SUNDAY...WITH HIGHS IN THE UPPER 70S TO
LOWER 80S. A SIGNIFICANT COOLDOWN IS IN STORE MONDAY/TUESDAY BEHIND
THE COLD FRONT AND WITH SIGNIFICANT CLOUD COVER...WITH HIGHS EACH
DAY MAINLY IN THE 60S. BREEZY CONDITIONS CAN BE EXPECTED MONDAY
AND TUESDAY.
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
DRY BUT COOL CONDITIONS WILL PREVAIL TUESDAY NIGHT THROUGH THURSDAY
UNDER HIGH PRESSURE. A WARMING TREND WILL DEVELOP LATE WEEK AS THE
FLOW TURNS AROUND TO THE S/SE. A FRONTAL BOUNDARY WILL BEGIN TO MAKE
AN APPROACH FRIDAY...BUT WITH THE BOUNDARY LIKELY WELL TO THE WEST
WILL KEEP CONDITIONS MAINLY DRY.
.AVIATION...
VFR WILL GENERALLY PREVAIL FOR THE NEXT 24 HOURS. PATCHY BR WILL
BE POSSIBLE AT VQQ/GNV 10-12Z...WITH LOCAL MVFR NEAR SHOWERS THIS
MORNING. WILL USE VCSH WITH PREVAILING LOW END VFR CIGS FOR THE
SHOWERS FOR JAX/CRG/VQQ/SSI FROM 12-18Z.
&&
.MARINE...HIGH PRESSURE TO THE EAST WILL RESULT IN SE WINDS TODAY AT
10-15 KNOTS. COMBINED SEAS WILL BE 2 NEAR SHORE AND UP TO 4 FEET
OFFSHORE... WITH AN EASTERLY SWELL PERSISTING. SCATTERED SHOWERS
WITH ISOLATED THUNDER POSSIBLE OVER THE WATERS THIS MORNING UNTIL
MID-AFTERNOON DUE TO UPPER DISTURBANCE MOVING EAST ACROSS THE AREA.
BENIGN WIND CONDITIONS WILL PREVAIL OVER THE WATERS SUNDAY.
NORTHERLY WINDS WILL INCREASE SUNDAY NIGHT IN THE WAKE OF A COLD
FRONT...WITH SCA LIKELY MONDAY. AS SURFACE LOW PRESSURE INTENSIFIES
RAPIDLY ACROSS THE MID ATLANTIC BY MIDWEEK...WINDS WILL INCREASE
FURTHER...WITH HIGH END SCA LIKELY LATER TUESDAY INTO WEDNESDAY.
RIP CURRENTS: MODERATE RISK TODAY DUE TO LINGERING LONG PERIOD
EASTERLY SWELLS. LOW RISK EXPECTED FOR SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 81 53 77 48 / 20 10 40 40
SSI 71 57 73 51 / 40 10 40 40
JAX 78 56 80 54 / 30 10 40 40
SGJ 76 58 75 57 / 40 10 30 30
GNV 79 56 78 56 / 20 10 40 40
OCF 81 55 81 58 / 10 10 40 40
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
ZIBURA/ALLEN/
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1249 PM EDT SAT MAR 22 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND BECOME
STATIONARY ACROSS NORTHERN SOUTH CAROLINA TONIGHT AS A WAVE OF LOW
PRESSURE DEVELOPS ALONG IT. THE STRENGTHENING COLD FRONT WILL
THEN PUSH THROUGH THE AREA SUNDAY WITH HIGH PRESSURE BUILDING IN
FROM THE NORTH MONDAY. A LOW PRESSURE SYSTEM WILL MOVE UP THE
COAST ON TUESDAY FOLLOWED BY DRY HIGH PRESSURE INTO THE LATE WEEK
PERIOD.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO MAJOR CHANGES. SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS...MAINLY NEAR THE COAST THIS AFTERNOON. HIGHS
TOPPING OUT IN THE MID TO UPPER 70S AWAY FROM THE COOLER COASTAL
AREAS...POSSIBLY EVEN REACHING 80 DEGREES IN A FEW
LOCALES...MAINLY ACROSS INTERIOR SOUTHEAST GEORGIA WHERE THERE
WILL BE THE BEST CHANCE OF MORE SUNSHINE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
TONIGHT...THE AFOREMENTIONED COLD FRONT WILL SINK SLOWLY SOUTH
TONIGHT...BECOMING STATIONARY ACROSS NORTHERN SOUTH CAROLINA AS A
WAVE OF LOW PRESSURE DEVELOPS ALONG IT OVER NORTHERN GEORGIA. IT
APPEARS THE FRONT WILL REMAIN NORTH OF THE LOCAL FORECAST AREA
THROUGH SUNRISE SUNDAY...KEEPING WARM SECTOR CONDITIONS IN PLACE.
THE RISK FOR SHOWER ACTIVITY WILL QUICKLY END AND MOVE OUT IN THE
ATLANTIC JUST BEFORE SUNSET AS THE BURST OF ASSOCIATED ISENTROPIC
ASSENT MOVES OUT OVER THE GULF STREAM IN RESPONSE TO THE MID-LEVEL
FLOW VEERING AHEAD OF THE COLD FRONT. EXPECT A DRY NIGHT TO
PREVAIL WITH LOWS RANGING FROM THE LOWER 50S INLAND TO THE UPPER
50S AT THE COAST. CLOUDS ARE EXPECTED THIN ENOUGH FOR MOSTLY
CLEAR TO PARTLY CLOUDY SKIES DURING THE EVENING HOURS...BEFORE
THICKENING BACK UP AFTER MIDNIGHT AS A 130 KT JET STREAK
APPROACHES FROM THE WEST.
SUNDAY...SHORTWAVE ENERGY WILL TRACK DIRECTLY ACROSS THE
SOUTHEAST STATES WITHIN PROGRESSIVE ZONAL FLOW ALOFT...PROVIDING
THE NECESSARY FORCING TO STRENGTHEN THE SURFACE WAVE AND EMBEDDED
COLD FRONT OVER THE FORECAST AREA. NUMERICAL MODEL SOLUTIONS AGREE
THAT PRECIPITATION WILL BE CONFINED JUST WEST OF THE FORECAST AREA
FOR MOST OF THE MORNING HOURS...BEFORE DEEP MOISTURE AND
CONVERGENCE INCREASE AS THE COLD FRONT MOVES TOWARD THE COASTLINE
BY THE AFTERNOON. HESITANT TO INDICATE RAIN CHANCES HIGHER THAN
ABOUT 40 PERCENT...AS A WESTERLY DEEP LAYER FLOW GENERALLY
PREVAILS DURING FRONTAL PROGRESSION AND PRECIPITABLE WATER VALUES
REMAIN NO HIGHER THAN 1.25 INCHES. COMPRESSIONAL HEATING AHEAD OF
THE FRONT...WHEN COMBINED WITH A WEST/SOUTHWEST FLOW FOR THE
MAJORITY OF THE DAYTIME HOURS...WILL ALLOW TEMPERATURES TO WARM
INTO THE MID TO UPPER 70S AWAY FROM THE LOCALLY COOLER COASTLINE.
RAIN CHANCES WILL DECREASE FROM WEST TO EAST OVERNIGHT AS THE
FRONT PULLS OFFSHORE. MODERATE NORTH FLOW WILL DEVELOP SUNDAY
NIGHT WITHIN A TIGHT PRESSURE GRADIENT BEHIND THE DEPARTING FRONT.
LOW TEMPERATURES IN THE LOW 40S INLAND TO THE UPPER 40S NEAR THE
COAST WILL BE THE COMBINED RESULT OF COOLER NORTHERLY WINDS WITH
INSULATING CLOUD COVER AND SOMEWHAT COUPLED FLOW.
MONDAY...TRANSIENT SURFACE HIGH PRESSURE WILL MOVE INTO THE MID
ATLANTIC STATES AND PUSH A WEDGE THROUGH THE SOUTHEAST REGION BY
MIDDAY. HIGH TEMPERATURES WILL BE SIGNIFICANTLY COLDER THAN SEEN
OVER THE PREVIOUS WEEKEND...SUPPRESSED IN THE UPPER 50S TO AROUND
60 DEGREES. SOUTHERN AND NORTHERN STREAM UPPER LEVEL ENERGY WILL
BEGIN TO MERGE NEAR THE SOUTHEAST UNITED STATES MONDAY
NIGHT...RAPIDLY SPINNING UP A LOW PRESSURE SYSTEM OFF THE COAST.
EXPECT PRECIPITATION TO SPREAD BACK INTO THE REGION WITHIN
INCREASING CONVERGENCE ALONG THE COASTLINE BY THE EARLY AFTERNOON
HOURS...WITH RAIN CHANCES INCREASING OVERNIGHT INTO THE 60 OR EVEN
70 PERCENT RANGE. BEST COVERAGE WILL LIKELY BE ACROSS COASTAL AND
NORTHERN AREAS CLOSEST TO THE RAPIDLY DEVELOPING LOW SYSTEM.
TUESDAY...RAIN COVERAGE WILL BE DECREASING FROM SOUTHWEST TO
NORTHEAST DURING THE MORNING HOURS...AS THE INTENSIFYING COASTAL
LOW PULLS FARTHER AWAY FROM THE AREA. DRY AND COLD CANADIAN HIGH
PRESSURE WILL RAPIDLY BUILD IN ITS WAKE...AND WHEN COMBINED WITH
HEIGHTS FALLING BENEATH AN UPPER TROUGH SWEEPING THE EAST COAST
AND STRONG COLD ADVECTION ON THE BACK SIDE OF THE LOW
SYSTEM...HIGH TEMPERATURES WILL ONCE AGAIN BE FAR BELOW SEASONAL
NORMALS. EXPECT TEMPERATURES TO ONLY PEAK IN THE MID 50S NORTH TO
AROUND 60 DEGREES SOUTH.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
DRY AND COLD HIGH PRESSURE RAPIDLY MOVES INTO THE REGION FROM THE
NORTHWEST TUESDAY NIGHT AND TRACKS DIRECTLY ACROSS THE AREA INTO
THURSDAY. A RATHER COLD AIR MASS WILL MAINTAIN BELOW NORMAL
TEMPERATURES THROUGH AT LEAST THE DAYTIME HOURS ON THURSDAY...BEFORE
THE AIR MASS MODIFIES ONCE THE SURFACE HIGH SETTLES INTO THE
ATLANTIC LATE THURSDAY INTO FRIDAY. EXPECT HIGH TEMPERATURES ON
WEDNESDAY TO ONLY BE IN THE MID TO UPPER 50S...WITH LOW
TEMPERATURES TUESDAY AND WEDNESDAY NIGHTS IN THE MID 30S INLAND TO
THE UPPER 30S NEAR THE COAST. HIGH AND LOW TEMPERATURES WILL THEN
STEADILY MODERATE THURSDAY THROUGH SATURDAY...RETURNING TO NEAR OR
SLIGHTLY ABOVE SEASONAL NORMALS. MEDIUM RANGE MODELS SUGGEST THAT
ANOTHER FRONTAL SYSTEM AND ASSOCIATED WAVES OF LOW PRESSURE COULD
INTRODUCE RAIN CHANCES AGAIN FOR FRIDAY AND SATURDAY...WITH THE
REGION LINGERING ON THE WESTERN PERIPHERY OF THE ATLANTIC HIGH
PRESSURE.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
GENERALLY VFR. DEEPER MOISTURE MOVING UP THE COAST THIS AFTERNOON
COULD PRODUCE SOME SHOWERS/MVFR CIGS AT EITHER TERM...BUT MOSTLY
AT KCHS. A FEW WEAK THUNDERSTORMS ARE ALSO POSSIBLE. LATE
TONIGHT/EARLY SUN MORNING THERE COULD BE SOME FOG WITH MVFR VSBYS
DUE TO LINGERING LOW-LEVEL MOISTURE AND DRIER CONDITIONS ALOFT...ESPECIALLY
AT KCHS.
EXTENDED AVIATION OUTLOOK...LOW CHANCES OF MVFR CIGS/VSBYS SUNDAY
NIGHT INTO EARLY MONDAY WITH A PASSING COLD FRONT. HIGHER CHANCES
OF MVFR CIGS/VSBYS MONDAY NIGHT AND TUESDAY...AS A LOW PRESSURE
SYSTEM TRACKS ALONG THE SOUTHEAST COAST.
&&
.MARINE...
TODAY...LIGHT SOUTHERLY WIND REGIME WILL REMAIN IN TACT AS HIGH
PRESSURE SHIFTS FARTHER OUT INTO THE ATLANTIC AND A COLD FRONT
APPROACHES FROM THE NORTHWEST. WINDS WILL GENERALLY REMAIN 10 KT
OR LESS THROUGH THE DAY WITH SEAS 1-3 FT NEARSHORE WATERS...3-4 FT
OFFSHORE WATERS.
TONIGHT...EVEN LIGHTER WINDS ARE EXPECTED TONIGHT AS A VERY BAGGY
PRESSURE GRADIENT DEVELOPS SOUTH OF AN APPROACHING COLD FRONT.
WINDS WILL VEER WEST AS THE FRONT BECOMES STATIONARY OVER NORTHERN
SOUTH CAROLINA WITH WITH SPEEDS LESS THAN 10 KT AND SEAS 1-2 FT
NEARSHORE WATERS AND 2-4 FT OFFSHORE WATERS.
SUNDAY THROUGH WEDNESDAY...MARINE CONDITIONS WILL DETERIORATE BY
SUNDAY NIGHT WITH STRONG HIGH PRESSURE BUILDING IN THE WAKE OF A
COLD FRONT. SMALL CRAFT ADVISORIES ARE LIKELY ACROSS ALL WATERS BY
SUNDAY NIGHT AND POSSIBLY CONTINUING THROUGH THE PERIOD...AS A
ROBUST LOW PRESSURE SYSTEM MOVES UP THE COAST TUESDAY AND IS
RAPIDLY FOLLOWED BY ANOTHER STRONG INLAND HIGH PRESSURE.
SEA FOG...INCREASING DEWPOINTS OVERSPREADING THE VERY CHILLY
SHELF WATERS COULD SUPPORT THE FORMATION SEA FOG LATER TODAY AND
INTO TONIGHT. CONFIDENCE IS ALWAYS LOW WITH THE ONSET OF THESE
EVENTS...ESPECIALLY IN THE PRESENCE OF POTENTIAL SHOWER/TSTM
ACTIVITY. HOWEVER...OUTPUT FROM BOTH THE RAP AND NAM SHOW QUITE A
BIT OF SEA FOG FORMING OFF THE SOUTHEAST GEORGIA COAST LATER THIS
MORNING AND SPREADING NORTHEAST ALONG THE LOWER SOUTH CAROLINA
COAST THROUGH THE DAY. THE SCENARIO CERTAINLY LOOKS PLAUSIBLE
GIVEN THE TIME OF YEAR SO WILL INTRODUCE A MENTION OF PATCHY FOG
IN THE GRIDS AND TEXT PRODUCTS. THE FOG COULD BECOME DENSE WITH
VSBYS 1 NM OR LESS AT TIMES. LATER SHIFTS MAY VERY WELL NEED TO
HIT THE SEA FOG FORECAST HARDER AS TRENDS BECOME MORE APPARENT.
MARINE DENSE FOG ADVISORIES ARE A POSSIBILITY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...RJB
SHORT TERM...
LONG TERM...
AVIATION...RJB
MARINE...
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1031 AM EDT SAT MAR 22 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND BECOME
STATIONARY ACROSS NORTHERN SOUTH CAROLINA TONIGHT AS A WAVE OF LOW
PRESSURE DEVELOPS ALONG IT. THE STRENGTHENING COLD FRONT WILL
THEN PUSH THROUGH THE AREA SUNDAY WITH HIGH PRESSURE BUILDING IN
FROM THE NORTH MONDAY. A LOW PRESSURE SYSTEM WILL MOVE UP THE
COAST ON TUESDAY FOLLOWED BY DRY HIGH PRESSURE INTO THE LATE WEEK
PERIOD.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST PRETTY MUCH ON TARGET FOR TODAY. LATEST RADAR IMAGERY
SHOWERS SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS MOVING NORTH
ALONG/NEAR THE GEORGIA COAST SO WE INITIALIZED WITH SLIGHTLY
HIGHER RAIN CHANCES THERE /UP TO 40 PERCENT/. EXPECT THIS GENERAL
TREND TO CONTINUE THROUGH THE DAY AS A BATCH OF DEEPER MOISTURE
MOVES UP THE COAST AND LOW-MID LEVEL INSTABILITY REMAINS
SUFFICIENT FOR SOME THUNDER. DESPITE PLENTY OF CLOUDS WE EXPECT A
RATHER WARM DAY WITH HIGHS LIKELY TOPPING OUT IN THE MID TO UPPER
70S...POSSIBLY REACHING 80 DEGREES IN A FEW LOCALES...MAINLY
ACROSS INTERIOR SOUTHEAST GEORGIA WHERE THERE WILL BE THE BEST
CHANCE OF MORE LATE DAY SUNSHINE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
TONIGHT...THE AFOREMENTIONED COLD FRONT WILL SINK SLOWLY SOUTH
TONIGHT...BECOMING STATIONARY ACROSS NORTHERN SOUTH CAROLINA AS A
WAVE OF LOW PRESSURE DEVELOPS ALONG IT OVER NORTHERN GEORGIA. IT
APPEARS THE FRONT WILL REMAIN NORTH OF THE LOCAL FORECAST AREA
THROUGH SUNRISE SUNDAY...KEEPING WARM SECTOR CONDITIONS IN PLACE.
THE RISK FOR SHOWER ACTIVITY WILL QUICKLY END AND MOVE OUT IN THE
ATLANTIC JUST BEFORE SUNSET AS THE BURST OF ASSOCIATED ISENTROPIC
ASSENT MOVES OUT OVER THE GULF STREAM IN RESPONSE TO THE MID-LEVEL
FLOW VEERING AHEAD OF THE COLD FRONT. EXPECT A DRY NIGHT TO
PREVAIL WITH LOWS RANGING FROM THE LOWER 50S INLAND TO THE UPPER
50S AT THE COAST. CLOUDS ARE EXPECTED THIN ENOUGH FOR MOSTLY
CLEAR TO PARTLY CLOUDY SKIES DURING THE EVENING HOURS...BEFORE
THICKENING BACK UP AFTER MIDNIGHT AS A 130 KT JET STREAK
APPROACHES FROM THE WEST.
SUNDAY...SHORTWAVE ENERGY WILL TRACK DIRECTLY ACROSS THE
SOUTHEAST STATES WITHIN PROGRESSIVE ZONAL FLOW ALOFT...PROVIDING
THE NECESSARY FORCING TO STRENGTHEN THE SURFACE WAVE AND EMBEDDED
COLD FRONT OVER THE FORECAST AREA. NUMERICAL MODEL SOLUTIONS AGREE
THAT PRECIPITATION WILL BE CONFINED JUST WEST OF THE FORECAST AREA
FOR MOST OF THE MORNING HOURS...BEFORE DEEP MOISTURE AND
CONVERGENCE INCREASE AS THE COLD FRONT MOVES TOWARD THE COASTLINE
BY THE AFTERNOON. HESITANT TO INDICATE RAIN CHANCES HIGHER THAN
ABOUT 40 PERCENT...AS A WESTERLY DEEP LAYER FLOW GENERALLY
PREVAILS DURING FRONTAL PROGRESSION AND PRECIPITABLE WATER VALUES
REMAIN NO HIGHER THAN 1.25 INCHES. COMPRESSIONAL HEATING AHEAD OF
THE FRONT...WHEN COMBINED WITH A WEST/SOUTHWEST FLOW FOR THE
MAJORITY OF THE DAYTIME HOURS...WILL ALLOW TEMPERATURES TO WARM
INTO THE MID TO UPPER 70S AWAY FROM THE LOCALLY COOLER COASTLINE.
RAIN CHANCES WILL DECREASE FROM WEST TO EAST OVERNIGHT AS THE
FRONT PULLS OFFSHORE. MODERATE NORTH FLOW WILL DEVELOP SUNDAY
NIGHT WITHIN A TIGHT PRESSURE GRADIENT BEHIND THE DEPARTING FRONT.
LOW TEMPERATURES IN THE LOW 40S INLAND TO THE UPPER 40S NEAR THE
COAST WILL BE THE COMBINED RESULT OF COOLER NORTHERLY WINDS WITH
INSULATING CLOUD COVER AND SOMEWHAT COUPLED FLOW.
MONDAY...TRANSIENT SURFACE HIGH PRESSURE WILL MOVE INTO THE MID
ATLANTIC STATES AND PUSH A WEDGE THROUGH THE SOUTHEAST REGION BY
MIDDAY. HIGH TEMPERATURES WILL BE SIGNIFICANTLY COLDER THAN SEEN
OVER THE PREVIOUS WEEKEND...SUPPRESSED IN THE UPPER 50S TO AROUND
60 DEGREES. SOUTHERN AND NORTHERN STREAM UPPER LEVEL ENERGY WILL
BEGIN TO MERGE NEAR THE SOUTHEAST UNITED STATES MONDAY
NIGHT...RAPIDLY SPINNING UP A LOW PRESSURE SYSTEM OFF THE COAST.
EXPECT PRECIPITATION TO SPREAD BACK INTO THE REGION WITHIN
INCREASING CONVERGENCE ALONG THE COASTLINE BY THE EARLY AFTERNOON
HOURS...WITH RAIN CHANCES INCREASING OVERNIGHT INTO THE 60 OR EVEN
70 PERCENT RANGE. BEST COVERAGE WILL LIKELY BE ACROSS COASTAL AND
NORTHERN AREAS CLOSEST TO THE RAPIDLY DEVELOPING LOW SYSTEM.
TUESDAY...RAIN COVERAGE WILL BE DECREASING FROM SOUTHWEST TO
NORTHEAST DURING THE MORNING HOURS...AS THE INTENSIFYING COASTAL
LOW PULLS FARTHER AWAY FROM THE AREA. DRY AND COLD CANADIAN HIGH
PRESSURE WILL RAPIDLY BUILD IN ITS WAKE...AND WHEN COMBINED WITH
HEIGHTS FALLING BENEATH AN UPPER TROUGH SWEEPING THE EAST COAST
AND STRONG COLD ADVECTION ON THE BACK SIDE OF THE LOW
SYSTEM...HIGH TEMPERATURES WILL ONCE AGAIN BE FAR BELOW SEASONAL
NORMALS. EXPECT TEMPERATURES TO ONLY PEAK IN THE MID 50S NORTH TO
AROUND 60 DEGREES SOUTH.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
DRY AND COLD HIGH PRESSURE RAPIDLY MOVES INTO THE REGION FROM THE
NORTHWEST TUESDAY NIGHT AND TRACKS DIRECTLY ACROSS THE AREA INTO
THURSDAY. A RATHER COLD AIR MASS WILL MAINTAIN BELOW NORMAL
TEMPERATURES THROUGH AT LEAST THE DAYTIME HOURS ON THURSDAY...BEFORE
THE AIR MASS MODIFIES ONCE THE SURFACE HIGH SETTLES INTO THE
ATLANTIC LATE THURSDAY INTO FRIDAY. EXPECT HIGH TEMPERATURES ON
WEDNESDAY TO ONLY BE IN THE MID TO UPPER 50S...WITH LOW
TEMPERATURES TUESDAY AND WEDNESDAY NIGHTS IN THE MID 30S INLAND TO
THE UPPER 30S NEAR THE COAST. HIGH AND LOW TEMPERATURES WILL THEN
STEADILY MODERATE THURSDAY THROUGH SATURDAY...RETURNING TO NEAR OR
SLIGHTLY ABOVE SEASONAL NORMALS. MEDIUM RANGE MODELS SUGGEST THAT
ANOTHER FRONTAL SYSTEM AND ASSOCIATED WAVES OF LOW PRESSURE COULD
INTRODUCE RAIN CHANCES AGAIN FOR FRIDAY AND SATURDAY...WITH THE
REGION LINGERING ON THE WESTERN PERIPHERY OF THE ATLANTIC HIGH
PRESSURE.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
GENERALLY VFR. SHOWERS ARE POSSIBLE LATER THIS MORNING AT KSAV
AND THIS AFTERNOON AT KCHS AS AN AREA OF DEEPER MOISTURE SHIFTS
UP THE COAST. SOME THUNDER IS ALSO POSSIBLE. BASED ON LATEST
TRENDS WE MAY NEED TO AMEND FOR SOME MVFR CIGS AT KSAV .
EXTENDED AVIATION OUTLOOK...LOW CHANCES OF MVFR CIGS/VSBYS SUNDAY
NIGHT INTO EARLY MONDAY WITH A PASSING COLD FRONT. HIGHER CHANCES
OF MVFR CIGS/VSBYS MONDAY NIGHT AND TUESDAY...AS A LOW PRESSURE
SYSTEM TRACKS ALONG THE SOUTHEAST COAST.
&&
.MARINE...
TODAY...LIGHT SOUTHERLY WIND REGIME WILL REMAIN IN TACT AS HIGH
PRESSURE SHIFTS FARTHER OUT INTO THE ATLANTIC AND A COLD FRONT
APPROACHES FROM THE NORTHWEST. WINDS WILL GENERALLY REMAIN 10 KT
OR LESS THROUGH THE DAY WITH SEAS 1-3 FT NEARSHORE WATERS...3-4 FT
OFFSHORE WATERS.
TONIGHT...EVEN LIGHTER WINDS ARE EXPECTED TONIGHT AS A VERY BAGGY
PRESSURE GRADIENT DEVELOPS SOUTH OF AN APPROACHING COLD FRONT.
WINDS WILL VEER WEST AS THE FRONT BECOMES STATIONARY OVER NORTHERN
SOUTH CAROLINA WITH WITH SPEEDS LESS THAN 10 KT AND SEAS 1-2 FT
NEARSHORE WATERS AND 2-4 FT OFFSHORE WATERS.
SUNDAY THROUGH WEDNESDAY...MARINE CONDITIONS WILL DETERIORATE BY
SUNDAY NIGHT WITH STRONG HIGH PRESSURE BUILDING IN THE WAKE OF A
COLD FRONT. SMALL CRAFT ADVISORIES ARE LIKELY ACROSS ALL WATERS BY
SUNDAY NIGHT AND POSSIBLY CONTINUING THROUGH THE PERIOD...AS A
ROBUST LOW PRESSURE SYSTEM MOVES UP THE COAST TUESDAY AND IS
RAPIDLY FOLLOWED BY ANOTHER STRONG INLAND HIGH PRESSURE.
SEA FOG...INCREASING DEWPOINTS OVERSPREADING THE VERY CHILLY
SHELF WATERS COULD SUPPORT THE FORMATION SEA FOG LATER TODAY AND
INTO TONIGHT. CONFIDENCE IS ALWAYS LOW WITH THE ONSET OF THESE
EVENTS...ESPECIALLY IN THE PRESENCE OF POTENTIAL SHOWER/TSTM
ACTIVITY. HOWEVER...OUTPUT FROM BOTH THE RAP AND NAM SHOW QUITE A
BIT OF SEA FOG FORMING OFF THE SOUTHEAST GEORGIA COAST LATER THIS
MORNING AND SPREADING NORTHEAST ALONG THE LOWER SOUTH CAROLINA
COAST THROUGH THE DAY. THE SCENARIO CERTAINLY LOOKS PLAUSIBLE
GIVEN THE TIME OF YEAR SO WILL INTRODUCE A MENTION OF PATCHY FOG
IN THE GRIDS AND TEXT PRODUCTS. THE FOG COULD BECOME DENSE WITH
VSBYS 1 NM OR LESS AT TIMES. LATER SHIFTS MAY VERY WELL NEED TO
HIT THE SEA FOG FORECAST HARDER AS TRENDS BECOME MORE APPARENT.
MARINE DENSE FOG ADVISORIES ARE A POSSIBILITY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...RJB
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
657 AM EDT SAT MAR 22 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND BECOME
STATIONARY ACROSS NORTHERN SOUTH CAROLINA TONIGHT AS A WAVE OF LOW
PRESSURE DEVELOPS ALONG IT. THE STRENGTHENING COLD FRONT WILL
THEN PUSH THROUGH THE AREA SUNDAY WITH HIGH PRESSURE BUILDING IN
FROM THE NORTH MONDAY. A LOW PRESSURE SYSTEM WILL MOVE UP THE
COAST ON TUESDAY FOLLOWED BY DRY HIGH PRESSURE INTO THE LATE WEEK
PERIOD.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO MAJOR CHANGES WERE MADE WITH THE SUNRISE UPDATE. KJAX RADAR
SHOWS SHOWER ACTIVITY BREAKING OUT ALONG THE NORTHEAST FLORIDA
COAST AS EXPECTED. H3R IS DOING A FINE JOB WITH ITS DEPICTION AND
MATCHES THE GOING FORECAST WELL.
A ZONAL FLOW ALOFT WILL REMAIN IN TACT OVER THE SOUTHEAST U.S.
TODAY AS NORTHERN AND SOUTHERN STREAM JET ENERGY PHASES OVER THE
LOWER AND MID-MISSISSIPPI VALLEYS. AT THE SURFACE...A COLD FRONT
WILL APPROACH FROM THE NORTHWEST TODAY WITH ALL OF SOUTHEAST SOUTH
CAROLINA AND SOUTHEAST GEORGIA REMAINING SOLIDLY ENTRENCHED IN THE
WARM SECTOR. TEMPERATURES WILL RISE QUICKLY AFTER SUNRISE DESPITE
THE PRESENCE OF A THICK CIRRUS CANOPY WITH HIGHS REACHING THE MID-
UPPER 70S AWAY FROM THE BEACHES. A QUICK SHORT OF COASTAL
ISENTROPIC ASSENT ALONG THE 295-300K ISO-SURFACES COUPLED WITH
FORCED UVM ASSOCIATED WITH THE LEFT EXIT REGION OF A 100 KT JET
STREAK WILL BRING A RISK FOR ISOLATED TO SCATTERED SHOWERS LATER
THIS MORNING AND AFTERNOON...MAINLY ACROSS THE COASTAL COUNTIES.
GENERALLY FOLLOWED THE H3R/NAM/RAP REFLECTIVITY/QPF
PROGNOSTICATIONS TO CONSTRUCT HOURLY POPS...WHICH WILL RANGE FROM
10-20 PERCENT INLAND TO THE 30-40 PERCENT AT THE COAST. FORECAST
SOUNDINGS AND VARIOUS INSTABILITY PLOTS SUGGEST ENOUGH INSTABILITY
WILL BE PRESENT TO SUPPORT A FEW TSTMS...ALTHOUGH THE PRESENCE OF
LINGERING MID-LEVEL DRY AIR AND THE POSSIBILITY OF A VERY SHALLOW
MARINE LAYER COULD BE LIMITING FACTORS FOR THE DEVELOPMENT OF
VIGOROUS UPDRAFTS. THE TSTM FORECAST WILL BE LIMITED TO A SLIGHT
CHANCE FOR NOW GIVEN THIS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
TONIGHT...THE AFOREMENTIONED COLD FRONT WILL SINK SLOWLY SOUTH
TONIGHT...BECOMING STATIONARY ACROSS NORTHERN SOUTH CAROLINA AS A
WAVE OF LOW PRESSURE DEVELOPS ALONG IT OVER NORTHERN GEORGIA. IT
APPEARS THE FRONT WILL REMAIN NORTH OF THE LOCAL FORECAST AREA
THROUGH SUNRISE SUNDAY...KEEPING WARM SECTOR CONDITIONS IN PLACE.
THE RISK FOR SHOWER ACTIVITY WILL QUICKLY END AND MOVE OUT IN THE
ATLANTIC JUST BEFORE SUNSET AS THE BURST OF ASSOCIATED ISENTROPIC
ASSENT MOVES OUT OVER THE GULF STREAM IN RESPONSE TO THE MID-LEVEL
FLOW VEERING AHEAD OF THE COLD FRONT. EXPECT A DRY NIGHT TO
PREVAIL WITH LOWS RANGING FROM THE LOWER 50S INLAND TO THE UPPER
50S AT THE COAST. CLOUDS ARE EXPECTED THIN ENOUGH FOR MOSTLY
CLEAR TO PARTLY CLOUDY SKIES DURING THE EVENING HOURS...BEFORE
THICKENING BACK UP AFTER MIDNIGHT AS A 130 KT JET STREAK
APPROACHES FROM THE WEST.
SUNDAY...SHORTWAVE ENERGY WILL TRACK DIRECTLY ACROSS THE
SOUTHEAST STATES WITHIN PROGRESSIVE ZONAL FLOW ALOFT...PROVIDING
THE NECESSARY FORCING TO STRENGTHEN THE SURFACE WAVE AND EMBEDDED
COLD FRONT OVER THE FORECAST AREA. NUMERICAL MODEL SOLUTIONS AGREE
THAT PRECIPITATION WILL BE CONFINED JUST WEST OF THE FORECAST AREA
FOR MOST OF THE MORNING HOURS...BEFORE DEEP MOISTURE AND
CONVERGENCE INCREASE AS THE COLD FRONT MOVES TOWARD THE COASTLINE
BY THE AFTERNOON. HESITANT TO INDICATE RAIN CHANCES HIGHER THAN
ABOUT 40 PERCENT...AS A WESTERLY DEEP LAYER FLOW GENERALLY
PREVAILS DURING FRONTAL PROGRESSION AND PRECIPITABLE WATER VALUES
REMAIN NO HIGHER THAN 1.25 INCHES. COMPRESSIONAL HEATING AHEAD OF
THE FRONT...WHEN COMBINED WITH A WEST/SOUTHWEST FLOW FOR THE
MAJORITY OF THE DAYTIME HOURS...WILL ALLOW TEMPERATURES TO WARM
INTO THE MID TO UPPER 70S AWAY FROM THE LOCALLY COOLER COASTLINE.
RAIN CHANCES WILL DECREASE FROM WEST TO EAST OVERNIGHT AS THE
FRONT PULLS OFFSHORE. MODERATE NORTH FLOW WILL DEVELOP SUNDAY
NIGHT WITHIN A TIGHT PRESSURE GRADIENT BEHIND THE DEPARTING FRONT.
LOW TEMPERATURES IN THE LOW 40S INLAND TO THE UPPER 40S NEAR THE
COAST WILL BE THE COMBINED RESULT OF COOLER NORTHERLY WINDS WITH
INSULATING CLOUD COVER AND SOMEWHAT COUPLED FLOW.
MONDAY...TRANSIENT SURFACE HIGH PRESSURE WILL MOVE INTO THE MID
ATLANTIC STATES AND PUSH A WEDGE THROUGH THE SOUTHEAST REGION BY
MIDDAY. HIGH TEMPERATURES WILL BE SIGNIFICANTLY COLDER THAN SEEN
OVER THE PREVIOUS WEEKEND...SUPPRESSED IN THE UPPER 50S TO AROUND
60 DEGREES. SOUTHERN AND NORTHERN STREAM UPPER LEVEL ENERGY WILL
BEGIN TO MERGE NEAR THE SOUTHEAST UNITED STATES MONDAY
NIGHT...RAPIDLY SPINNING UP A LOW PRESSURE SYSTEM OFF THE COAST.
EXPECT PRECIPITATION TO SPREAD BACK INTO THE REGION WITHIN
INCREASING CONVERGENCE ALONG THE COASTLINE BY THE EARLY AFTERNOON
HOURS...WITH RAIN CHANCES INCREASING OVERNIGHT INTO THE 60 OR EVEN
70 PERCENT RANGE. BEST COVERAGE WILL LIKELY BE ACROSS COASTAL AND
NORTHERN AREAS CLOSEST TO THE RAPIDLY DEVELOPING LOW SYSTEM.
TUESDAY...RAIN COVERAGE WILL BE DECREASING FROM SOUTHWEST TO
NORTHEAST DURING THE MORNING HOURS...AS THE INTENSIFYING COASTAL
LOW PULLS FARTHER AWAY FROM THE AREA. DRY AND COLD CANADIAN HIGH
PRESSURE WILL RAPIDLY BUILD IN ITS WAKE...AND WHEN COMBINED WITH
HEIGHTS FALLING BENEATH AN UPPER TROUGH SWEEPING THE EAST COAST
AND STRONG COLD ADVECTION ON THE BACK SIDE OF THE LOW
SYSTEM...HIGH TEMPERATURES WILL ONCE AGAIN BE FAR BELOW SEASONAL
NORMALS. EXPECT TEMPERATURES TO ONLY PEAK IN THE MID 50S NORTH TO
AROUND 60 DEGREES SOUTH.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
DRY AND COLD HIGH PRESSURE RAPIDLY MOVES INTO THE REGION FROM THE
NORTHWEST TUESDAY NIGHT AND TRACKS DIRECTLY ACROSS THE AREA INTO
THURSDAY. A RATHER COLD AIR MASS WILL MAINTAIN BELOW NORMAL
TEMPERATURES THROUGH AT LEAST THE DAYTIME HOURS ON THURSDAY...BEFORE
THE AIR MASS MODIFIES ONCE THE SURFACE HIGH SETTLES INTO THE
ATLANTIC LATE THURSDAY INTO FRIDAY. EXPECT HIGH TEMPERATURES ON
WEDNESDAY TO ONLY BE IN THE MID TO UPPER 50S...WITH LOW
TEMPERATURES TUESDAY AND WEDNESDAY NIGHTS IN THE MID 30S INLAND TO
THE UPPER 30S NEAR THE COAST. HIGH AND LOW TEMPERATURES WILL THEN
STEADILY MODERATE THURSDAY THROUGH SATURDAY...RETURNING TO NEAR OR
SLIGHTLY ABOVE SEASONAL NORMALS. MEDIUM RANGE MODELS SUGGEST THAT
ANOTHER FRONTAL SYSTEM AND ASSOCIATED WAVES OF LOW PRESSURE COULD
INTRODUCE RAIN CHANCES AGAIN FOR FRIDAY AND SATURDAY...WITH THE
REGION LINGERING ON THE WESTERN PERIPHERY OF THE ATLANTIC HIGH
PRESSURE.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
VFR. SHOWER ACTIVITY DEVELOPING ACROSS THE NORTHEAST FLORIDA
COAST WILL CONTINUE TO EXPAND AND BRUSH THE COASTAL AREAS OF
SOUTHERN SOUTH CAROLINA AND SOUTHEAST GEORGIA LATER THIS MORNING.
ATTM IT APPEARS KCHS HAS THE BEST CHANCES FOR ANY DIRECT
IMPACTS...BUT EVEN NOW THE HIGHER RESOLUTION GUIDANCE KEEPS THE
BEST CHANCES EAST OF THAT TERMINAL. WILL SHOW A TEMPO GROUP FOR
MARGINAL MVFR CONDITIONS FROM 17-20Z TO ACCOUNT FOR POSSIBLE
ACTIVITY IN THE KCHS AREA WHILE KEEPING MVFR CIGS/VSBYS OUT OF
KSAV FOR NOW.
EXTENDED AVIATION OUTLOOK...LOW CHANCES OF MVFR CIGS/VSBYS SUNDAY
NIGHT INTO EARLY MONDAY WITH A PASSING COLD FRONT. HIGHER CHANCES
OF MVFR CIGS/VSBYS MONDAY NIGHT AND TUESDAY...AS A LOW PRESSURE
SYSTEM TRACKS ALONG THE SOUTHEAST COAST.
&&
.MARINE...
TODAY...LIGHT SOUTHERLY WIND REGIME WILL REMAIN IN TACT AS HIGH
PRESSURE SHIFTS FARTHER OUT INTO THE ATLANTIC AND A COLD FRONT
APPROACHES FROM THE NORTHWEST. WINDS WILL GENERALLY REMAIN 10 KT
OR LESS THROUGH THE DAY WITH SEAS 1-3 FT NEARSHORE WATERS...3-4 FT
OFFSHORE WATERS.
TONIGHT...EVEN LIGHTER WINDS ARE EXPECTED TONIGHT AS A VERY BAGGY
PRESSURE GRADIENT DEVELOPS SOUTH OF AN APPROACHING COLD FRONT.
WINDS WILL VEER WEST AS THE FRONT BECOMES STATIONARY OVER NORTHERN
SOUTH CAROLINA WITH WITH SPEEDS LESS THAN 10 KT AND SEAS 1-2 FT
NEARSHORE WATERS AND 2-4 FT OFFSHORE WATERS.
SUNDAY THROUGH WEDNESDAY...MARINE CONDITIONS WILL DETERIORATE BY
SUNDAY NIGHT WITH STRONG HIGH PRESSURE BUILDING IN THE WAKE OF A
COLD FRONT. SMALL CRAFT ADVISORIES ARE LIKELY ACROSS ALL WATERS BY
SUNDAY NIGHT AND POSSIBLY CONTINUING THROUGH THE PERIOD...AS A
ROBUST LOW PRESSURE SYSTEM MOVES UP THE COAST TUESDAY AND IS
RAPIDLY FOLLOWED BY ANOTHER STRONG INLAND HIGH PRESSURE.
SEA FOG...INCREASING DEWPOINTS OVERSPREADING THE VERY CHILLY
SHELF WATERS COULD SUPPORT THE FORMATION SEA FOG LATER TODAY AND
INTO TONIGHT. CONFIDENCE IS ALWAYS LOW WITH THE ONSET OF THESE
EVENTS...ESPECIALLY IN THE PRESENCE OF POTENTIAL SHOWER/TSTM
ACTIVITY. HOWEVER...OUTPUT FROM BOTH THE RAP AND NAM SHOW QUITE A
BIT OF SEA FOG FORMING OFF THE SOUTHEAST GEORGIA COAST LATER THIS
MORNING AND SPREADING NORTHEAST ALONG THE LOWER SOUTH CAROLINA
COAST THROUGH THE DAY. THE SCENARIO CERTAINLY LOOKS PLAUSIBLE
GIVEN THE TIME OF YEAR SO WILL INTRODUCE A MENTION OF PATCHY FOG
IN THE GRIDS AND TEXT PRODUCTS. THE FOG COULD BECOME DENSE WITH
VSBYS 1 NM OR LESS AT TIMES. LATER SHIFTS MAY VERY WELL NEED TO
HIT THE SEA FOG FORECAST HARDER AS TRENDS BECOME MORE APPARENT.
MARINE DENSE FOG ADVISORIES ARE A POSSIBILITY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST/WMS
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
350 AM EDT SAT MAR 22 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND BECOME
STATIONARY ACROSS NORTHERN SOUTH CAROLINA TONIGHT AS A WAVE OF LOW
PRESSURE DEVELOPS ALONG IT. THE STRENGTHENING COLD FRONT WILL
THEN PUSH THROUGH THE AREA SUNDAY WITH HIGH PRESSURE BUILDING IN
FROM THE NORTH MONDAY. A LOW PRESSURE SYSTEM WILL MOVE UP THE
COAST ON TUESDAY FOLLOWED BY DRY HIGH PRESSURE INTO THE LATE WEEK
PERIOD.
&&
.NEAR TERM /THROUGH TODAY/...
A ZONAL FLOW ALOFT WILL REMAIN IN TACT OVER THE SOUTHEAST U.S.
TODAY AS NORTHERN AND SOUTHERN STREAM JET ENERGY PHASES OVER THE
LOWER AND MID-MISSISSIPPI VALLEYS. AT THE SURFACE...A COLD FRONT
WILL APPROACH FROM THE NORTHWEST TODAY WITH ALL OF SOUTHEAST SOUTH
CAROLINA AND SOUTHEAST GEORGIA REMAINING SOLIDLY ENTRENCHED IN THE
WARM SECTOR. TEMPERATURES WILL RISE QUICKLY AFTER SUNRISE DESPITE
THE PRESENCE OF A THICK CIRRUS CANOPY WITH HIGHS REACHING THE MID-
UPPER 70S AWAY FROM THE BEACHES. A QUICK SHORT OF COASTAL
ISENTROPIC ASSENT ALONG THE 295-300K ISO-SURFACES COUPLED WITH
FORCED UVM ASSOCIATED WITH THE LEFT EXIT REGION OF A 100 KT JET
STREAK WILL BRING A RISK FOR ISOLATED TO SCATTERED SHOWERS LATER
THIS MORNING AND AFTERNOON...MAINLY ACROSS THE COASTAL COUNTIES.
GENERALLY FOLLOWED THE H3R/NAM/RAP REFLECTIVITY/QPF
PROGNOSTICATIONS TO CONSTRUCT HOURLY POPS...WHICH WILL RANGE FROM
10-20 PERCENT INLAND TO THE 30-40 PERCENT AT THE COAST. FORECAST
SOUNDINGS AND VARIOUS INSTABILITY PLOTS SUGGEST ENOUGH INSTABILITY
WILL BE PRESENT TO SUPPORT A FEW TSTMS...ALTHOUGH THE PRESENCE OF
LINGERING MID-LEVEL DRY AIR AND THE POSSIBILITY OF A VERY SHALLOW
MARINE LAYER COULD BE LIMITING FACTORS FOR THE DEVELOPMENT OF
VIGOROUS UPDRAFTS. THE TSTM FORECAST WILL BE LIMITED TO A SLIGHT
CHANCE FOR NOW GIVEN THIS.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
TONIGHT...THE AFOREMENTIONED COLD FRONT WILL SINK SLOWLY SOUTH
TONIGHT...BECOMING STATIONARY ACROSS NORTHERN SOUTH CAROLINA AS A
WAVE OF LOW PRESSURE DEVELOPS ALONG IT OVER NORTHERN GEORGIA. IT
APPEARS THE FRONT WILL REMAIN NORTH OF THE LOCAL FORECAST AREA
THROUGH SUNRISE SUNDAY...KEEPING WARM SECTOR CONDITIONS IN PLACE.
THE RISK FOR SHOWER ACTIVITY WILL QUICKLY END AND MOVE OUT IN THE
ATLANTIC JUST BEFORE SUNSET AS THE BURST OF ASSOCIATED ISENTROPIC
ASSENT MOVES OUT OVER THE GULF STREAM IN RESPONSE TO THE MID-LEVEL
FLOW VEERING AHEAD OF THE COLD FRONT. EXPECT A DRY NIGHT TO
PREVAIL WITH LOWS RANGING FROM THE LOWER 50S INLAND TO THE UPPER
50S AT THE COAST. CLOUDS ARE EXPECTED THIN ENOUGH FOR MOSTLY
CLEAR TO PARTLY CLOUDY SKIES DURING THE EVENING HOURS...BEFORE
THICKENING BACK UP AFTER MIDNIGHT AS A 130 KT JET STREAK
APPROACHES FROM THE WEST.
SUNDAY...SHORTWAVE ENERGY WILL TRACK DIRECTLY ACROSS THE
SOUTHEAST STATES WITHIN PROGRESSIVE ZONAL FLOW ALOFT...PROVIDING
THE NECESSARY FORCING TO STRENGTHEN THE SURFACE WAVE AND EMBEDDED
COLD FRONT OVER THE FORECAST AREA. NUMERICAL MODEL SOLUTIONS AGREE
THAT PRECIPITATION WILL BE CONFINED JUST WEST OF THE FORECAST AREA
FOR MOST OF THE MORNING HOURS...BEFORE DEEP MOISTURE AND
CONVERGENCE INCREASE AS THE COLD FRONT MOVES TOWARD THE COASTLINE
BY THE AFTERNOON. HESITANT TO INDICATE RAIN CHANCES HIGHER THAN
ABOUT 40 PERCENT...AS A WESTERLY DEEP LAYER FLOW GENERALLY
PREVAILS DURING FRONTAL PROGRESSION AND PRECIPITABLE WATER VALUES
REMAIN NO HIGHER THAN 1.25 INCHES. COMPRESSIONAL HEATING AHEAD OF
THE FRONT...WHEN COMBINED WITH A WEST/SOUTHWEST FLOW FOR THE
MAJORITY OF THE DAYTIME HOURS...WILL ALLOW TEMPERATURES TO WARM
INTO THE MID TO UPPER 70S AWAY FROM THE LOCALLY COOLER COASTLINE.
RAIN CHANCES WILL DECREASE FROM WEST TO EAST OVERNIGHT AS THE
FRONT PULLS OFFSHORE. MODERATE NORTH FLOW WILL DEVELOP SUNDAY
NIGHT WITHIN A TIGHT PRESSURE GRADIENT BEHIND THE DEPARTING FRONT.
LOW TEMPERATURES IN THE LOW 40S INLAND TO THE UPPER 40S NEAR THE
COAST WILL BE THE COMBINED RESULT OF COOLER NORTHERLY WINDS WITH
INSULATING CLOUD COVER AND SOMEWHAT COUPLED FLOW.
MONDAY...TRANSIENT SURFACE HIGH PRESSURE WILL MOVE INTO THE MID
ATLANTIC STATES AND PUSH A WEDGE THROUGH THE SOUTHEAST REGION BY
MIDDAY. HIGH TEMPERATURES WILL BE SIGNIFICANTLY COLDER THAN SEEN
OVER THE PREVIOUS WEEKEND...SUPPRESSED IN THE UPPER 50S TO AROUND
60 DEGREES. SOUTHERN AND NORTHERN STREAM UPPER LEVEL ENERGY WILL
BEGIN TO MERGE NEAR THE SOUTHEAST UNITED STATES MONDAY
NIGHT...RAPIDLY SPINNING UP A LOW PRESSURE SYSTEM OFF THE COAST.
EXPECT PRECIPITATION TO SPREAD BACK INTO THE REGION WITHIN
INCREASING CONVERGENCE ALONG THE COASTLINE BY THE EARLY AFTERNOON
HOURS...WITH RAIN CHANCES INCREASING OVERNIGHT INTO THE 60 OR EVEN
70 PERCENT RANGE. BEST COVERAGE WILL LIKELY BE ACROSS COASTAL AND
NORTHERN AREAS CLOSEST TO THE RAPIDLY DEVELOPING LOW SYSTEM.
TUESDAY...RAIN COVERAGE WILL BE DECREASING FROM SOUTHWEST TO
NORTHEAST DURING THE MORNING HOURS...AS THE INTENSIFYING COASTAL
LOW PULLS FARTHER AWAY FROM THE AREA. DRY AND COLD CANADIAN HIGH
PRESSURE WILL RAPIDLY BUILD IN ITS WAKE...AND WHEN COMBINED WITH
HEIGHTS FALLING BENEATH AN UPPER TROUGH SWEEPING THE EAST COAST
AND STRONG COLD ADVECTION ON THE BACK SIDE OF THE LOW
SYSTEM...HIGH TEMPERATURES WILL ONCE AGAIN BE FAR BELOW SEASONAL
NORMALS. EXPECT TEMPERATURES TO ONLY PEAK IN THE MID 50S NORTH TO
AROUND 60 DEGREES SOUTH.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
DRY AND COLD HIGH PRESSURE RAPIDLY MOVES INTO THE REGION FROM THE
NORTHWEST TUESDAY NIGHT AND TRACKS DIRECTLY ACROSS THE AREA INTO
THURSDAY. A RATHER COLD AIR MASS WILL MAINTAIN BELOW NORMAL
TEMPERATURES THROUGH AT LEAST THE DAYTIME HOURS ON THURSDAY...BEFORE
THE AIR MASS MODIFIES ONCE THE SURFACE HIGH SETTLES INTO THE
ATLANTIC LATE THURSDAY INTO FRIDAY. EXPECT HIGH TEMPERATURES ON
WEDNESDAY TO ONLY BE IN THE MID TO UPPER 50S...WITH LOW
TEMPERATURES TUESDAY AND WEDNESDAY NIGHTS IN THE MID 30S INLAND TO
THE UPPER 30S NEAR THE COAST. HIGH AND LOW TEMPERATURES WILL THEN
STEADILY MODERATE THURSDAY THROUGH SATURDAY...RETURNING TO NEAR OR
SLIGHTLY ABOVE SEASONAL NORMALS. MEDIUM RANGE MODELS SUGGEST THAT
ANOTHER FRONTAL SYSTEM AND ASSOCIATED WAVES OF LOW PRESSURE COULD
INTRODUCE RAIN CHANCES AGAIN FOR FRIDAY AND SATURDAY...WITH THE
REGION LINGERING ON THE WESTERN PERIPHERY OF THE ATLANTIC HIGH
PRESSURE.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
VFR. LOW PROBABILITIES FOR LIGHT RAIN SHOWERS AND MVFR CIGS/VSBYS
IMPACTING THE TERMINALS AFTER SUNRISE. THE BEST CHANCE WILL BE AT
KCHS...MAINLY FROM LATE MORNING THROUGH MID-AFTERNOON.
PROBABILITIES ARE TOO LOW TO MAKE A MENTION FOR THE 06Z TAF CYCLE.
EXTENDED AVIATION OUTLOOK...LOW CHANCES OF MVFR CIGS/VSBYS SUNDAY
NIGHT INTO EARLY MONDAY WITH A PASSING COLD FRONT. HIGHER CHANCES
OF MVFR CIGS/VSBYS MONDAY NIGHT AND TUESDAY...AS A LOW PRESSURE
SYSTEM TRACKS ALONG THE SOUTHEAST COAST.
&&
.MARINE...
TODAY...LIGHT SOUTHERLY WIND REGIME WILL REMAIN IN TACT AS HIGH
PRESSURE SHIFTS FARTHER OUT INTO THE ATLANTIC AND A COLD FRONT
APPROACHES FROM THE NORTHWEST. WINDS WILL GENERALLY REMAIN 10 KT
OR LESS THROUGH THE DAY WITH SEAS 1-3 FT NEARSHORE WATERS...3-4 FT
OFFSHORE WATERS.
TONIGHT...EVEN LIGHTER WINDS ARE EXPECTED TONIGHT AS A VERY BAGGY
PRESSURE GRADIENT DEVELOPS SOUTH OF AN APPROACHING COLD FRONT.
WINDS WILL VEER WEST AS THE FRONT BECOMES STATIONARY OVER NORTHERN
SOUTH CAROLINA WITH WITH SPEEDS LESS THAN 10 KT AND SEAS 1-2 FT
NEARSHORE WATERS AND 2-4 FT OFFSHORE WATERS.
SUNDAY THROUGH WEDNESDAY...MARINE CONDITIONS WILL DETERIORATE BY
SUNDAY NIGHT WITH STRONG HIGH PRESSURE BUILDING IN THE WAKE OF A
COLD FRONT. SMALL CRAFT ADVISORIES ARE LIKELY ACROSS ALL WATERS BY
SUNDAY NIGHT AND POSSIBLY CONTINUING THROUGH THE PERIOD...AS A
ROBUST LOW PRESSURE SYSTEM MOVES UP THE COAST TUESDAY AND IS
RAPIDLY FOLLOWED BY ANOTHER STRONG INLAND HIGH PRESSURE.
SEA FOG...INCREASING DEWPOINTS OVERSPREADING THE VERY CHILLY
SHELF WATERS COULD SUPPORT THE FORMATION SEA FOG LATER TODAY AND
INTO TONIGHT. CONFIDENCE IS ALWAYS LOW WITH THE ONSET OF THESE
EVENTS...ESPECIALLY IN THE PRESENCE OF POTENTIAL SHOWER/TSTM
ACTIVITY. HOWEVER...OUTPUT FROM BOTH THE RAP AND NAM SHOW QUITE A
BIT OF SEA FOG FORMING OFF THE SOUTHEAST GEORGIA COAST LATER THIS
MORNING AND SPREADING NORTHEAST ALONG THE LOWER SOUTH CAROLINA
COAST THROUGH THE DAY. THE SCENARIO CERTAINLY LOOKS PLAUSIBLE
GIVEN THE TIME OF YEAR SO WILL INTRODUCE A MENTION OF PATCHY FOG
IN THE GRIDS AND TEXT PRODUCTS. THE FOG COULD BECOME DENSE WITH
VSBYS 1 NM OR LESS AT TIMES. LATER SHIFTS MAY VERY WELL NEED TO
HIT THE SEA FOG FORECAST HARDER AS TRENDS BECOME MORE APPARENT.
MARINE DENSE FOG ADVISORIES ARE A POSSIBILITY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST/WMS
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
239 AM CDT SAT MAR 22 2014
.DISCUSSION...
257 PM CDT
SYNOPSIS...THE SPRING-LIKE DAY TODAY WILL GIVE WAY TO WELL BELOW
NORMAL TEMPERATURES TONIGHT THROUGH EARLY NEXT WEEK. MAY EVEN SEE A
FEW LIGHT RAIN SHOWERS PRIMARILY EAST OF I-39. THE MAJORITY OF THE
AREA WILL SEE A DRY WEEKEND...BUT GUIDANCE IS HINTING AT LAKE EFFECT
SNOW IMPACTING BOTH NW INDIANA AND FAR NE ILLINOIS TOMORROW NIGHT
INTO SUNDAY. ADDITIONAL PRECIP IS EXPECTED MONDAY AFTERNOON THROUGH
TUESDAY AND LATE NEXT WEEK.
REST OF TODAY AND SATURDAY...
A DEEP SHORT WAVE TROUGH IS OVER NW MINNESOTA WITH A CORRESPONDING
SURFACE LOW OVER THE NORTHERN MISSISSIPPI RIVER VALLEY. THE WARM
FRONT HAS ADVANCED FROM MOLINE IL THROUGH CENTRAL INDIANA...AND HAVE
NOTICED WINDS ARE FINALLY STARTING TO COME AROUND TO SOUTH OR
SOUTHWEST. STILL EXPECTING TO REACH THE UPPER 50S DOWNTOWN AND
SHOULD SEE TEMPS RISE RAPIDLY ONCE THE WINDS BECOME SOUTH. FAR NE
IL...LAKE COUNTY...WILL HOLD ON TO SE WINDS THE LONGEST AND WILL
MOST LIKELY MISS OUT ON 50S TODAY. THE OTHER SIDE OF THE COIN IS
ALONG THE SOUTHERN CWA WHERE MID TO UPPER 60S ARE LIKELY.
THE WARM FRONT WILL NOT MAKE IT THROUGH THE ENTIRE CWA TODAY BECAUSE
THE LOW WILL MOVE DIRECTLY OVER THE CWA LATE THIS AFTN INTO THIS
EVENING. WINDS TURN NW BEHIND THE LOW AND ITS COLD FRONT AND COLD
AIR BEGINS TO FLOOD INTO THE REGION.
RADAR IS PICKING UP A FEW LIGHT ECHOES ALONG THE WARM FRONT RIGHT
NOW NORTH OF BURLINGTON IOWA. THE HRRR SUGGESTS THOSE SHOWERS WILL
PERSIST...BUT NOT BUYING INTO THAT THEORY AS DEWPOINT DEPRESSIONS
ACROSS THE REGION REMAIN LARGE. GUIDANCE CONTINUES TO HINT AT
SHOWERS DEVELOPING ALONG THE COLD FRONT...AND ISOLATED SHOWERS LOOK
POSSIBLE. STILL CONCERNED ABOUT LOW LEVEL MOISTURE...BUT SHOULD
HAVE AMPLE FORCING FROM THE FRONT...LOW...AND IMPRESSIVE SHORT WAVE
TROUGH. AS SUCH HAVE A BAND OF LOW END CHANCE POPS MOVING ACROSS
THE EASTERN CWA LATE THIS AFTN INTO THIS EVENING. NOT EXPECTING
MUCH MORE THAN A FEW HUNDREDTHS OF PRECIP OUT OF ANY GIVEN
SHOWER...EXCEPT FOR OVER NW INDIANA. FORCING IS MAXIMIZED AND MAY
SEE UPWARDS OF 0.05 INCHES OF RAIN. STILL NOTHING TO WRITE HOME
ABOUT...BUT MORE THAN THE REST OF THE CWA.
TEMPS FALL INTO THE UPPER 20S IN NORTH CENTRAL IL AND TO AROUND
FREEZING ACROSS NW INDIANA TONIGHT. TEMPS REBOUND A LITTLE SATURDAY
WITH HIGHS IN THE UPPER 30S TO MID 40S DOWN SOUTH. EXPECTING THE
MORNING TO BE MOSTLY SUNNY...BUT HAVE CLOUDS INCREASING AS FLOW
TURNS OFF OF THE LAKE.
SATURDAY NIGHT THROUGH SUNDAY...
A BROAD UPPER LEVEL TROUGH SPANS THE NORTHERN U.S. AND SOUTHERN
CANADA SATURDAY NIGHT WITH A WEAK TROUGH AXIS MOVING THROUGH THE
REGION SUNDAY AFTERNOON. NORTHWEST FLOW SETS UP ALOFT BEHIND THE
TROUGH AXIS. AT THE SURFACE...HIGH PRESSURE BUILDS OVER THE
NORTHERN PLAINS SATURDAY NIGHT AND MOVES OVER REGION SUNDAY NIGHT.
AS THE LOW SHIFTS OVER NEW ENGLAND AND THE HIGH BUILDS DOWN THE
PLAINS...WE COULD BE LOOKING AT A LAKE EFFECT SNOW SITUATION. RIGHT
NOW NOT OVERLY IMPRESSED BY THE SET UP AS DELTA TS ARE MARGINAL AT
BEST...BUT THE MODELED WIND FIELDS SHOW GOOD CONVERGENCE OVER THE
LAKE. THE LOCAL ARW IS ALREADY INDICATING A SINGLE BAND OF LAKE
EFFECT PRECIP LATE SATURDAY EVENING THROUGH SUNDAY MORNING. KEPT
THE POPS A BIT MORE BROAD AT THIS POINT WITH MAX POPS IN THE CHANCE
RANGE. HAVE THE BAND STARTING OVER NW INDIANA...SHIFTING EAST TO
NEAR COOK AND LAKE COUNTIES IN IL EARLY SUNDAY MORNING...AND THEN
SHIFTING BACK ACROSS NW INDIANA AS THE HIGH BUILDS INTO THE REGION.
ONCE AGAIN DUE TO LOW CONFIDENCE IN IF THE SNOW WILL HAPPEN AND
WHERE IT WILL FALL...KEPT PRECIP AMOUNTS LIGHT. HAVE LESS THAN HALF
INCH JUST ALONG THE LAKE IN NW INDIANA FOR NOW.
FOR TEMPS...COLD AIR CONTINUES TO SINK SOUTH THROUGH SUNDAY MORNING
WITH LOWS SATURDAY NIGHT RANGING FROM THE UPPER TEENS TO THE MID
20S. SUNDAYS HIGHS WILL BE IN THE 30S.
EXTENDED...MONDAY THROUGH THURSDAY...
AN UPPER LEVEL LOW MOVES OVER HUDSON BAY MONDAY AND ROTATES EAST
INTO NORTHERN QUEBEC TUESDAY EVENING. ITS ASSOCIATED TROUGH PASSES
OVER THE CWA TUESDAY...WITH NORTHWEST FLOW OVER THE CWA TUESDAY
EVENING THROUGH WEDNESDAY AFTERNOON. THERE IS BRIEF RIDGING
WEDNESDAY NIGHT INTO THURSDAY BEFORE THE NEXT SHORTWAVE THURSDAY
NIGHT OR FRIDAY.
THE SURFACE HIGH SHIFTS EAST MONDAY WITH A WEAK SURFACE LOW AND/OR
COLD FRONT ASSOCIATED WITH THE TROUGH AXIS MOVING THROUGH THE CWA
TUESDAY MORNING. HAVE SNOW MOVING INTO THE REGION LATE SUNDAY
AFTERNOON AND PERSISTING THROUGH TUESDAY. ITS STILL TOO FAR OUT TO
BE TALKING ABOUT SNOWFALL AMOUNTS...BUT FORCING AND MOISTURE LOOK
DECENT. TAKING A QUICK LOOK AT THE GFS SOUNDINGS...THE ONLY ISSUE I
SEE IS A SHRINKING DENDRITIC GROWTH ZONE AS THE EVENT GOES ON.
HIGH PRESSURE MOVES IN BEHIND THE TROUGH TUESDAY EVENING THROUGH
WEDNESDAY EVENING...WITH YET ANOTHER LOW LATE NEXT WEEK. THE GFS IS
MUCH SLOWER AND FARTHER SOUTH WITH THE NEXT LOW SO CONFIDENCE IS LOW
IN EXACTLY WHERE THE LOW WILL TRACK. THIS OF COURSE WILL PLAY A
ROLL IN PRECIP TYPES...BUT BOTH THE GFS AND ECMWF INDICATE PRECIP
OVER THE REGION.
HIGH TEMPS REMAIN IN THE 30S MONDAY AND TUESDAY...BUT THEN BEGIN TO
RISE WITH HIGHS IN THE 40S TO 50S POSSIBLE THURSDAY AND FRIDAY.
AS MENTIONED ABOVE...PRECIP TYPES LATE NEXT WEEK WILL DEPEND ON
THE LOWS PATH AND SUBSEQUENT SURFACE TEMPS. FOR NOW USED THE
FORECASTED SURFACE TEMPS TO CREATE THE WEATHER GRIDS.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* NORTHWEST WINDS GUSTING NEAR 25 KT AT TIMES INTO PRE-DAWN SAT.
* SCT-BKN HIGH MVFR/VFR STRATOCU 3000-3500 FT.
* NORTHWEST WINDS GUSTING 15-20 KT AT TIMES SATURDAY...POSSIBLY
BECOMING NORTH OR NORTH-NORTHEAST LATER IN THE AFTERNOON.
RATZER
//DISCUSSION...UPDATED 06Z...
SURFACE LOW PRESSURE WAS MOVING AWAY TO THE EAST ACROSS LAKE ERIE
EARLY THIS MORNING...WITH HIGH PRESSURE RIDGE BUILDING SLOWLY
SOUTH-SOUTHEAST ACROSS THE PLAINS TO OUR WEST. NORTHWEST GRADIENT
WINDS GUSTING 20-25 KT ACROSS THE REGION AS COLD ADVECTION HELPS
TO KEEP BOUNDARY LAYER WELL-MIXED OVERNIGHT. THE PATTERN WILL
HOLD THROUGH THE FORECAST PERIOD...WITH NORTHWEST WINDS GRADUALLY
VEERING FROM 310-320 DEG OVERNIGHT TO 330-350 DEG ON SATURDAY.
HIGH-RES MODELS INDICATE WINDS ALONG WESTERN SHORE OF LAKE
MICHIGAN MAY SHIFT NORTH-NORTHEAST SATURDAY AFTERNOON...THOUGH
MAINLY AFFECTING GYY IN VARIOUS GUIDANCE RUNS. STILL...A SHIFT TO
THE NORTH-NORTHEAST AT ORD/MDW IN THE LATE AFTERNOON NOT OUT OF
THE QUESTION.
EXTENSIVE AREA OF STRATOCU EXISTS UPSTREAM ACROSS THE UPPER
MISSISSIPPI VALLEY WITH BASES 2500-3500 FT...THOUGH GRADUAL
ADVECTION OF DRIER LOW LEVEL AIR AND SUBSIDENCE BEHIND DEPARTING
TROUGH WAS HELPING TO ERODE SOME HOLES IN THE BKN/OVC CIGS. EXPECT
BKN CIGS WILL END UP PREVAILING...THOUGH WITH BASES GENERALLY IN
THE 3000-3500 FT RANGE ACROSS THE CHICAGO TERMINALS. ANY HOLES
THAT DEVELOP MAY FILL BACK IN DURING THE DAY. GREATER POTENTIAL
FOR MVFR CIGS WILL BE AT GYY LATER IN THE DAY/EVENING...AS WINDS
SHIFT MORE DIRECTLY OFF OF THE LAKE. LAKE EFFECT SNOW POTENTIAL
INCREASES AT GYY BEYOND THE 06Z END OF THE TAF...AS COLDER AIR
CONTINUES TO SPREAD IN ALOFT.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN WIND TRENDS THROUGH EARLY SATURDAY
AFTERNOON.
* MEDIUM-HIGH CONFIDENCE IN VFR/HIGH MVFR CIGS MAINLY 3000 FT OR
ABOVE.
* LOW CONFIDENCE IN WIND SHIFT TO THE NORTH-NORTHEAST LATE
SATURDAY AFTERNOON.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...SLIGHT CHANCE OF SHSN AND SUB VFR...OTHERWISE VFR.
MONDAY...CHANCE -SN AND SUB VFR MONDAY EVENING/NIGHT.
TUESDAY...CHANCE -SN AND SUB VFR.
WEDNESDAY...VFR.
THURSDAY...CHANCE -RA AND SUB VFR.
MDB
&&
.MARINE...
238 AM CDT
GUSTY NORTHWEST WINDS 25-30 KT WILL VERY GRADUALLY DIMINISH TODAY
AND TONIGHT...AS LOW PRESSURE TRACKS EAST AWAY FROM THE REGION AND A
BROAD HIGH PRESSURE RIDGE BUILDS SOUTHEAST ACROSS THE PLAINS. COLD
ADVECTION IN THE LOW LEVELS WILL STEEPEN LAPSE RATES OVER THE LAKE
EARLY THIS MORNING...WITH STRONG MIXING IN THE MARINE BOUNDARY LAYER
PRODUCING WIND GUSTS AROUND 30 KT THIS MORNING. SLIGHT EASING OF THE
GRADIENT WILL ALLOW GUSTS TO DIMINISH TO 20-25 KT THIS AFTERNOON...
AND EVENTUALLY TO AROUND 15 KT BY SUNDAY MORNING AS THE PLAINS HIGH
SHIFTS INTO THE UPPER MISSISSIPPI VALLEY. WINDS WILL DIMINISH
FURTHER AND BECOME MORE VARIABLE IN DIRECTION SUNDAY NIGHT AS THE
HIGH PRESSURE RIDGE MOVES ACROSS THE LAKE.
A RATHER PROGRESSIVE UPPER PATTERN WILL BRING ANOTHER TROUGH OF LOW
PRESSURE ACROSS THE WESTERN LAKES MONDAY NIGHT...WITH A RENEWED
SURGE OF COLDER AIR AND GUSTY NORTHERLY WINDS TUESDAY. HIGH PRESSURE
QUICKLY FOLLOWS TUESDAY NIGHT HOWEVER...WITH WINDS BECOMING SOUTH
AGAIN AHEAD OF THE NEXT SYSTEM ON WEDNESDAY.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 AM SATURDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1244 AM CDT SAT MAR 22 2014
.DISCUSSION...
257 PM CDT
SYNOPSIS...THE SPRING-LIKE DAY TODAY WILL GIVE WAY TO WELL BELOW
NORMAL TEMPERATURES TONIGHT THROUGH EARLY NEXT WEEK. MAY EVEN SEE A
FEW LIGHT RAIN SHOWERS PRIMARILY EAST OF I-39. THE MAJORITY OF THE
AREA WILL SEE A DRY WEEKEND...BUT GUIDANCE IS HINTING AT LAKE EFFECT
SNOW IMPACTING BOTH NW INDIANA AND FAR NE ILLINOIS TOMORROW NIGHT
INTO SUNDAY. ADDITIONAL PRECIP IS EXPECTED MONDAY AFTERNOON THROUGH
TUESDAY AND LATE NEXT WEEK.
REST OF TODAY AND SATURDAY...
A DEEP SHORT WAVE TROUGH IS OVER NW MINNESOTA WITH A CORRESPONDING
SURFACE LOW OVER THE NORTHERN MISSISSIPPI RIVER VALLEY. THE WARM
FRONT HAS ADVANCED FROM MOLINE IL THROUGH CENTRAL INDIANA...AND HAVE
NOTICED WINDS ARE FINALLY STARTING TO COME AROUND TO SOUTH OR
SOUTHWEST. STILL EXPECTING TO REACH THE UPPER 50S DOWNTOWN AND
SHOULD SEE TEMPS RISE RAPIDLY ONCE THE WINDS BECOME SOUTH. FAR NE
IL...LAKE COUNTY...WILL HOLD ON TO SE WINDS THE LONGEST AND WILL
MOST LIKELY MISS OUT ON 50S TODAY. THE OTHER SIDE OF THE COIN IS
ALONG THE SOUTHERN CWA WHERE MID TO UPPER 60S ARE LIKELY.
THE WARM FRONT WILL NOT MAKE IT THROUGH THE ENTIRE CWA TODAY BECAUSE
THE LOW WILL MOVE DIRECTLY OVER THE CWA LATE THIS AFTN INTO THIS
EVENING. WINDS TURN NW BEHIND THE LOW AND ITS COLD FRONT AND COLD
AIR BEGINS TO FLOOD INTO THE REGION.
RADAR IS PICKING UP A FEW LIGHT ECHOES ALONG THE WARM FRONT RIGHT
NOW NORTH OF BURLINGTON IOWA. THE HRRR SUGGESTS THOSE SHOWERS WILL
PERSIST...BUT NOT BUYING INTO THAT THEORY AS DEWPOINT DEPRESSIONS
ACROSS THE REGION REMAIN LARGE. GUIDANCE CONTINUES TO HINT AT
SHOWERS DEVELOPING ALONG THE COLD FRONT...AND ISOLATED SHOWERS LOOK
POSSIBLE. STILL CONCERNED ABOUT LOW LEVEL MOISTURE...BUT SHOULD
HAVE AMPLE FORCING FROM THE FRONT...LOW...AND IMPRESSIVE SHORT WAVE
TROUGH. AS SUCH HAVE A BAND OF LOW END CHANCE POPS MOVING ACROSS
THE EASTERN CWA LATE THIS AFTN INTO THIS EVENING. NOT EXPECTING
MUCH MORE THAN A FEW HUNDREDTHS OF PRECIP OUT OF ANY GIVEN
SHOWER...EXCEPT FOR OVER NW INDIANA. FORCING IS MAXIMIZED AND MAY
SEE UPWARDS OF 0.05 INCHES OF RAIN. STILL NOTHING TO WRITE HOME
ABOUT...BUT MORE THAN THE REST OF THE CWA.
TEMPS FALL INTO THE UPPER 20S IN NORTH CENTRAL IL AND TO AROUND
FREEZING ACROSS NW INDIANA TONIGHT. TEMPS REBOUND A LITTLE SATURDAY
WITH HIGHS IN THE UPPER 30S TO MID 40S DOWN SOUTH. EXPECTING THE
MORNING TO BE MOSTLY SUNNY...BUT HAVE CLOUDS INCREASING AS FLOW
TURNS OFF OF THE LAKE.
SATURDAY NIGHT THROUGH SUNDAY...
A BROAD UPPER LEVEL TROUGH SPANS THE NORTHERN U.S. AND SOUTHERN
CANADA SATURDAY NIGHT WITH A WEAK TROUGH AXIS MOVING THROUGH THE
REGION SUNDAY AFTERNOON. NORTHWEST FLOW SETS UP ALOFT BEHIND THE
TROUGH AXIS. AT THE SURFACE...HIGH PRESSURE BUILDS OVER THE
NORTHERN PLAINS SATURDAY NIGHT AND MOVES OVER REGION SUNDAY NIGHT.
AS THE LOW SHIFTS OVER NEW ENGLAND AND THE HIGH BUILDS DOWN THE
PLAINS...WE COULD BE LOOKING AT A LAKE EFFECT SNOW SITUATION. RIGHT
NOW NOT OVERLY IMPRESSED BY THE SET UP AS DELTA TS ARE MARGINAL AT
BEST...BUT THE MODELED WIND FIELDS SHOW GOOD CONVERGENCE OVER THE
LAKE. THE LOCAL ARW IS ALREADY INDICATING A SINGLE BAND OF LAKE
EFFECT PRECIP LATE SATURDAY EVENING THROUGH SUNDAY MORNING. KEPT
THE POPS A BIT MORE BROAD AT THIS POINT WITH MAX POPS IN THE CHANCE
RANGE. HAVE THE BAND STARTING OVER NW INDIANA...SHIFTING EAST TO
NEAR COOK AND LAKE COUNTIES IN IL EARLY SUNDAY MORNING...AND THEN
SHIFTING BACK ACROSS NW INDIANA AS THE HIGH BUILDS INTO THE REGION.
ONCE AGAIN DUE TO LOW CONFIDENCE IN IF THE SNOW WILL HAPPEN AND
WHERE IT WILL FALL...KEPT PRECIP AMOUNTS LIGHT. HAVE LESS THAN HALF
INCH JUST ALONG THE LAKE IN NW INDIANA FOR NOW.
FOR TEMPS...COLD AIR CONTINUES TO SINK SOUTH THROUGH SUNDAY MORNING
WITH LOWS SATURDAY NIGHT RANGING FROM THE UPPER TEENS TO THE MID
20S. SUNDAYS HIGHS WILL BE IN THE 30S.
EXTENDED...MONDAY THROUGH THURSDAY...
AN UPPER LEVEL LOW MOVES OVER HUDSON BAY MONDAY AND ROTATES EAST
INTO NORTHERN QUEBEC TUESDAY EVENING. ITS ASSOCIATED TROUGH PASSES
OVER THE CWA TUESDAY...WITH NORTHWEST FLOW OVER THE CWA TUESDAY
EVENING THROUGH WEDNESDAY AFTERNOON. THERE IS BRIEF RIDGING
WEDNESDAY NIGHT INTO THURSDAY BEFORE THE NEXT SHORTWAVE THURSDAY
NIGHT OR FRIDAY.
THE SURFACE HIGH SHIFTS EAST MONDAY WITH A WEAK SURFACE LOW AND/OR
COLD FRONT ASSOCIATED WITH THE TROUGH AXIS MOVING THROUGH THE CWA
TUESDAY MORNING. HAVE SNOW MOVING INTO THE REGION LATE SUNDAY
AFTERNOON AND PERSISTING THROUGH TUESDAY. ITS STILL TOO FAR OUT TO
BE TALKING ABOUT SNOWFALL AMOUNTS...BUT FORCING AND MOISTURE LOOK
DECENT. TAKING A QUICK LOOK AT THE GFS SOUNDINGS...THE ONLY ISSUE I
SEE IS A SHRINKING DENDRITIC GROWTH ZONE AS THE EVENT GOES ON.
HIGH PRESSURE MOVES IN BEHIND THE TROUGH TUESDAY EVENING THROUGH
WEDNESDAY EVENING...WITH YET ANOTHER LOW LATE NEXT WEEK. THE GFS IS
MUCH SLOWER AND FARTHER SOUTH WITH THE NEXT LOW SO CONFIDENCE IS LOW
IN EXACTLY WHERE THE LOW WILL TRACK. THIS OF COURSE WILL PLAY A
ROLL IN PRECIP TYPES...BUT BOTH THE GFS AND ECMWF INDICATE PRECIP
OVER THE REGION.
HIGH TEMPS REMAIN IN THE 30S MONDAY AND TUESDAY...BUT THEN BEGIN TO
RISE WITH HIGHS IN THE 40S TO 50S POSSIBLE THURSDAY AND FRIDAY.
AS MENTIONED ABOVE...PRECIP TYPES LATE NEXT WEEK WILL DEPEND ON
THE LOWS PATH AND SUBSEQUENT SURFACE TEMPS. FOR NOW USED THE
FORECASTED SURFACE TEMPS TO CREATE THE WEATHER GRIDS.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* NORTHWEST WINDS GUSTING NEAR 25 KT AT TIMES INTO PRE-DAWN SAT.
* SCT-BKN HIGH MVFR/VFR STRATOCU 3000-3500 FT.
* NORTHWEST WINDS GUSTING 15-20 KT AT TIMES SATURDAY...POSSIBLY
BECOMING NORTH OR NORTH-NORTHEAST LATER IN THE AFTERNOON.
RATZER
//DISCUSSION...UPDATED 06Z...
SURFACE LOW PRESSURE WAS MOVING AWAY TO THE EAST ACROSS LAKE ERIE
EARLY THIS MORNING...WITH HIGH PRESSURE RIDGE BUILDING SLOWLY
SOUTH-SOUTHEAST ACROSS THE PLAINS TO OUR WEST. NORTHWEST GRADIENT
WINDS GUSTING 20-25 KT ACROSS THE REGION AS COLD ADVECTION HELPS
TO KEEP BOUNDARY LAYER WELL-MIXED OVERNIGHT. THE PATTERN WILL
HOLD THROUGH THE FORECAST PERIOD...WITH NORTHWEST WINDS GRADUALLY
VEERING FROM 310-320 DEG OVERNIGHT TO 330-350 DEG ON SATURDAY.
HIGH-RES MODELS INDICATE WINDS ALONG WESTERN SHORE OF LAKE
MICHIGAN MAY SHIFT NORTH-NORTHEAST SATURDAY AFTERNOON...THOUGH
MAINLY AFFECTING GYY IN VARIOUS GUIDANCE RUNS. STILL...A SHIFT TO
THE NORTH-NORTHEAST AT ORD/MDW IN THE LATE AFTERNOON NOT OUT OF
THE QUESTION.
EXTENSIVE AREA OF STRATOCU EXISTS UPSTREAM ACROSS THE UPPER
MISSISSIPPI VALLEY WITH BASES 2500-3500 FT...THOUGH GRADUAL
ADVECTION OF DRIER LOW LEVEL AIR AND SUBSIDENCE BEHIND DEPARTING
TROUGH WAS HELPING TO ERODE SOME HOLES IN THE BKN/OVC CIGS. EXPECT
BKN CIGS WILL END UP PREVAILING...THOUGH WITH BASES GENERALLY IN
THE 3000-3500 FT RANGE ACROSS THE CHICAGO TERMINALS. ANY HOLES
THAT DEVELOP MAY FILL BACK IN DURING THE DAY. GREATER POTENTIAL
FOR MVFR CIGS WILL BE AT GYY LATER IN THE DAY/EVENING...AS WINDS
SHIFT MORE DIRECTLY OFF OF THE LAKE. LAKE EFFECT SNOW POTENTIAL
INCREASES AT GYY BEYOND THE 06Z END OF THE TAF...AS COLDER AIR
CONTINUES TO SPREAD IN ALOFT.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN WIND TRENDS THROUGH EARLY SATURDAY
AFTERNOON.
* MEDIUM-HIGH CONFIDENCE IN VFR/HIGH MVFR CIGS MAINLY 3000 FT OR
ABOVE.
* LOW CONFIDENCE IN WIND SHIFT TO THE NORTH-NORTHEAST LATE
SATURDAY AFTERNOON.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...SLIGHT CHANCE OF SHSN AND SUB VFR...OTHERWISE VFR.
MONDAY...CHANCE -SN AND SUB VFR MONDAY EVENING/NIGHT.
TUESDAY...CHANCE -SN AND SUB VFR.
WEDNESDAY...VFR.
THURSDAY...CHANCE -RA AND SUB VFR.
MDB
&&
.MARINE...
348 PM CDT
VARYING WINDS CAN BE EXPECTED ACROSS THE LAKE THIS AFTERNOON INTO
TONIGHT...AS AN AREA OF LOW PRESSURE AND ASSOCIATED BOUNDARIES
PUSH OVER THE LAKE. SOUTHEAST WINDS OUT AHEAD OF THIS SYSTEM WILL
BECOME MORE EASTERLY THIS EVENING BEFORE TURNING TO THE NORTH AND
NORTHWEST TONIGHT. AS THE WINDS BECOME MORE NORTHWEST...EXPECT
SPEEDS TO INCREASE TO 30 KT OVER THE OPEN WATERS AND WINDS OF
20-25 KT IN THE NEARSHORE TONIGHT. WITH DEPARTING LOW PRESSURE TO
THE EAST AND A LARGE HIGH BUILDING SOUTH OVER THE NORTHERN PLAINS
ON SATURDAY...NORTHERLY WINDS WILL PERSIST INTO SUNDAY BUT WITH
SPEEDS DIMINISHING THROUGH THE WEEKEND. THE START OF NEXT WEEK
WILL BE MARKED WITH THIS HIGH PRESSURE MOVING ACROSS THE LAKES
REGION AND THEN SHIFTING TO THE EAST...WHILE THE NEXT SYSTEM
APPROACHES FROM THE NORTHWEST MONDAY NIGHT INTO TUESDAY.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 AM SATURDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1119 AM MDT SAT MAR 22 2014
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 422 AM MDT SAT MAR 22 2014
MAIN FORECAST CONCERN WILL BE CHANCE/AMOUNT OF SNOW THROUGH THE
WEEKEND...TEMPERATURE ROLLERCOASTER INTO MONDAY...AND WINDS ON
SUNDAY AND MONDAY. SATELLITE SHOWING AN AMPLIFIED/COMPLICATED FLOW
PATTERN OVER THE PACIFIC WHICH TRANSITIONS INTO A BROAD TROUGHINESS
AND PROGRESSIVE WESTERLY FLOW OVER THE COUNTRY. SEVERAL SHORTWAVE
TROUGHS EMBEDDED WITHIN THAT FLOW. ONE OF MAIN CONCERN IS TROUGH
MOVING ACROSS THE GREAT BASIN WITH STRONGEST PORTION OF THE TROUGH
MOVING INTO SOUTHERN IDAHO. NEXT SHORTWAVE TROUGH IS MOVING INTO
WESTERN CANADA. COLD FRONT MOVED THROUGH WITH A SECONDARY COLD
FRONT AND MUCH COLDER AIR APPROACHING FROM THE NORTH AT THIS TIME.
AT JET LEVEL...MODELS APPEARED TO INITIALIZE FINE. AT MID
LEVELS...PER SATELLITE AND UPPER AIR ANALYSIS THE NAM WAS DOING
SLIGHTLY BETTER THAN THE OTHER OUTPUT...ESPECIALLY THE UKMET AND
ECMWF...WITH THE SREF THE WORST. THE NAM WAS DOING A LITTLE BETTER
THAN THE ECMWF AND GFS ON THE SURFACE WIND AND PRESSURE FIELD.
THE MODELS WERE A LITTLE WARM WITH THE GFS DOING A LITTLE BETTER
THAN THE UKMET...NAM AND CANADIAN ON THE LOW LEVEL THERMAL FIELD.
TODAY/TONIGHT...MAIN JET LOOKS TO STAY NOT TOO FAR TO THE NORTH
THROUGH THE MORNING. HOWEVER...MODELS DIFFER ON THE SUBTLE BUT
IMPORTANT DETAILS OVER US. AS IT LOOKS NOW THE RIGHT REAR QUADRANT
OF THE NORTHERN JET LOOKS TO BE NEAR OR OVER THE NORTHERN PORTION
OF OUR AREA AT 18Z. THE TREND THE LAST TWO DAYS IS TOO KEEP THIS A
LITTLE FURTHER NORTH AND BE A LITTLE SLOWER IN ARRIVING INTO OUR
AREA. MODELS BRING THIS RIGHT REAR QUADRANT ACROSS THE FORECAST AREA
THROUGH THE AFTERNOON. BY LATE IN THE AFTERNOON THIS RIGHT REAR
QUADRANT IS NEAR THE SOUTHERN END OF THE FORECAST AREA. BY MID
EVENING THIS JET IS EAST OF THE AREA WITH SOME POSSIBLE WEAK JET
AROUND THROUGH 06Z.
ABOVE MENTIONED SHORTWAVE TROUGH IS ALSO SLOWER TO ARRIVE WITH IT
BEGINNING TO AFFECT THE AREA BY LATE MORNING AND MOVING ACROSS MOST
OF THE AREA BY LATE AFTERNOON. BY LATE AFTERNOON IS NEAR THE
SOUTHERN END OF THE FORECAST AREA AND ALSO MOVES OUT OF THE AREA AT
THE SAME SPEED THE JET DOES. NOW WHAT LOOKS TO BE OCCURRING ON
SATELLITE IS BEING SHOWN BY TONIGHTS MODEL OUTPUT. THIS INCOMING
TROUGH STARTING TO SPLIT WITH THE NORTHERN PORTION MOVING THROUGH PER
DISCUSSION ABOVE. THE SOUTHERN PORTION LOOKS TO BE GOING SOUTH AND
WEST OF MY AREA.
MODELS HAVE BEEN WAFFLING EVEN IN THE NEAR TERM ON HOW FAST AND HOW
FAR TO DEVELOP PRECIPITATION THIS MORNING. A VERY SMALL AREA OF
SNOW HAS MOVED ACROSS THE NORTHERN OF THE AREA IN CONJUNCTION WITH A
PRELIMINARY WEAK SHORTWAVE. HRRR AND RUC CATCH THIS NICELY AND
DISSIPATE BY 12Z. AS THE ABOVE MENTIONED SHORTWAVE TROUGH...WHICH
GETS CLOSER TO THE AREA BY LATE MORNING...AND UPPER JET GETS
CLOSER...MODELS START DEVELOPING PRECIPITATION OVER THE NORTHERN
HALF AND ESPECIALLY THE NORTHWEST CORNER OF THE AREA. THIS AREA OF
PRECIPITATION GROWS IN COVERAGE AND SINKS SOUTH AND WEST THROUGH
THE AFTERNOON.
BY LATE AFTERNOON INTO THE EARLY EVENING GREATEST CHANCE OF
PRECIPITATION IN THE FAR SOUTH AND SOUTHWEST WHERE THE GREATEST LOW
LEVEL UPSLOPE COMPONENT RESIDES ALONG WITH THE RIGHT REAR QUADRANT
OF THE JET. AM A LITTLE CONCERNED THAT THE MODELS MAY BE CUTTING
OFF PRECIPITATION TOO SOON. A MID LEVEL BAROCLINIC ZONE/STRONG ZONE
OF NARROW FRONTOGENESIS DEVELOPS BEHIND THE EXITING SHORTWAVE TROUGH
AND JET. MODEL SOUNDINGS...EVEN FURTHER NORTH BEHIND THE MAIN LIFT...
STAY SATURATED REALLY CLOSE TO THE DENDRITIC ZONE INTO THE EVENING.
SO DID NOT REALLY START DECREASING THE PRECIPITATION UNTIL AFTER
MIDNIGHT.
PER ICE IN THE COLUMN AND VERY LOW WET BULB ZERO HEIGHTS...PHASE
SHOULD BE MOSTLY SNOW. HOWEVER...THE FAR SOUTH THAT SATURATES AND
COOLS LATER WILL STAY A MIXTURE FROM LATE AFTERNOON INTO EARLY
EVENING. DEFINITELY LOOKS LIKE 1 TO 2 INCHES WITH POSSIBLY 3
INCHES...MAINLY IN THE FAR WEST TO SOUTHWEST LOCATIONS...WILL OCCUR
WITH THIS SYSTEM.
MODELS DIFFER ON HOW WARM TEMPERATURES WILL GET. DUE TO THE THICK
CLOUD COVER...TEMPERATURES HAVE NOT COOLED AS MUCH THIS MORNING AS
WHAT THE MODELS THOUGHT. AGAIN TENDED TO FOLLOW THE COOLER GUIDANCE
DUE TO THE ABUNDANT CLOUD COVER AND STRENGTHENING LOW LEVEL UPSLOPE
AND COLD AIR ADVECTION.
SUNDAY/SUNDAY NIGHT...CLOUDS SHOULD CLEAR OUT BY LATE IN THE
MORNING. SURFACE RIDGE PULLS AWAY TO THE EAST WHILE ANOTHER LEE
TROUGH DEVELOPS TO OUR WEST AS A RESULT OF THE STRONG CROSS
MOUNTAIN FLOW. GRADIENT AND 3 HOUR PRESSURE FALLS WOULD INDICATE AT
LEAST BREEZY TO POSSIBLY WINDY CONDITIONS IN THE WESTERN HALF.
TEMPERATURES SHOULD BE WARMER BUT NOT SURE HOW MUCH. MODELS ARE
WARMER THAN THEY WERE YESTERDAY...ESPECIALLY THE NAM. DID WARM
TEMPERATURES A LITTLE BUT CONSIDERING THE LINGERING CLOUD COVER AND
RECYCLED COOL AIR...CHOSE TO GO CLOSER TO THE COOLER GUIDANCE.
DUE TO JET LIFT FROM JET SEGMENT IN ADVANCE OF NEXT INCOMING
SHORTWAVE TROUGH AND JET BEHIND THIS TROUGH COMBINED WITH A DECENT
MID LEVEL BAROCLINIC ZONE/FRONTOGENESIS AND THETA-E LAPSE RATES
NEAR ZERO WOULD DEFINITELY SUPPORT THE MENTION OF SOME KIND OF
PRECIPITATION. MODELS ARE EVEN SHOWING A SMALL AMOUNT OF ELEVATED
CAPE. MODELS EVEN BRING A FAIRLY STRONG PV ANOMALY. PROBLEM IS ALL
THE MODEL SHOWING A DRY AND UNSATURATED AIR MASS. BUT CONSIDERING
THE AMOUNT OF LIFT AND INSTABILITY...DECIDED TO JUST MENTION
FLURRIES AFTER MIDNIGHT.
MONDAY/MONDAY NIGHT...NEXT COLD FRONT WILL THROUGH THE AREA LATE
SUNDAY NIGHT INTO EARLY MONDAY MORNING AS A RESULT OF THE ABOVE
MENTIONED SHORTWAVE TROUGH. MODELS ARE SHOWING DECENT LOW LEVEL
LAPSE RATES ALONG WITH MODERATE TO STRONG DOWNWARD MOTION. THERE
LOOKS TO BE UNIDIRECTIONAL FLOW THROUGH NEARLY 700 MB. IT LOOKS LIKE
WE COULD GET WINDY...POSSIBLY NEAR WIND ADVISORY CRITERIA. THIS WILL
NEED TO BE CLOSELY WATCHED. TEMPERATURES SHOULD STILL BE WARM
DESPITE THE FRONTAL POSSIBLE PER PLENTY OF SUNSHINE AND PROGGED 850
MB TEMPERATURES.
ONLY THE ECMWF WAS SHOWING QPF FOR MONDAY NIGHT. HOWEVER IT LOOKS
LIKE THE MAIN LIFT IS NORTH AND EAST OF THE AREA WITH DRIER LOW
LEVELS. SO REMOVED THE SLIGHT CHANCE FROM THAT PERIOD. POSSIBLE IT
COULD JUST BE FLURRIES ONCE AGAIN.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 422 AM MDT SAT MAR 22 2014
THE TUESDAY THROUGH FRIDAY PERIOD WILL HAVE SEVERAL UPPER LEVEL
SHORT WAVE TROUGHS MOVE THROUGH. THE ONLY ONE OF CONSEQUENCE MOVES
THROUGH THE AREA THURSDAY AND THURSDAY NIGHT.
TUESDAY AN UPPER LEVEL RIDGE BEGINS BUILDING OVER THE AREA. AHEAD
OF THE RIDGE THE RIGHT ENTRANCE OF THE 500MB JET MOVES OVER THE
AREA. UNFORTUNATELY THE MODELS HAVE DRIED OUT THE ENVIRONMENT UNDER
THE RIGHT ENTRANCE REGION SO WILL KEEP THE DAY DAY. THE COLD FRONT
WHICH MOVES IN DURING THE EARLY MORNING WILL BE PUSHED BACK NORTH
DURING THE AFTERNOON.
WEDNESDAY THE UPPER LEVEL RIDGE WILL BE POSITIONED OVER THE AREA.
MODELS MOVE A SUBTLE SHORT WAVE TROUGH THROUGH THE PERIPHERY OF THE
RIDGE...BUT KEEP IT SOUTH OF THE AREA. THE RIDGE AND BREEZY
SOUTHWEST WINDS WILL ALLOW TEMPERATURES TO WARM ALMOST 20 DEGREES
ABOVE NORMAL. IN ADDITION THE GUSTY WINDS NEAR 25 MPH COMBINED WITH
RELATIVE HUMIDITIES OF LESS THAN 20 PERCENT MAY LEAD TO HAZARDOUS
FIRE WEATHER CONDITIONS.
WEDNESDAY NIGHT PRECIP. CHANCES RETURN TO THE AREA AHEAD OF A
STRONGER SHORT WAVE TROUGH THAT WILL MOVE THROUGH THURSDAY. MODELS
SHOW DRIER AIR MOVING IN FROM THE SOUTHWEST JUST AHEAD OF THE TROUGH
WHICH WILL LIMIT PRECIP. CHANCES TO THE NORTHERN HALF OF THE AREA.
THURSDAY A STRONGER UPPER LEVEL SHORT WAVE TROUGH MOVES THROUGH THE
AREA BEHIND THE EXITING RIDGE. MODELS DISAGREE WHEN THE TROUGH WILL
MOVE THROUGH...VARYING FROM THE AFTERNOON TO EARLY EVENING. PRECIP.
CHANCES WITH THE TROUGH DO NOT LOOK AS PROMISING AS YESTERDAY DUE TO
MODELS TRENDING TOWARD A MORE SHALLOW SHORT WAVE TROUGH...WHICH WILL
ALLOW THE DRIER AIR TO MOVE FURTHER NORTH OVER MOST OF THE AREA.
MEANWHILE NORTH WINDS WILL STRENGTHEN BEHIND THE COLD FRONT THAT
WILL MOVE THROUGH THE AREA. TEMPERATURES WILL RANGE FROM BELOW
NORMAL OVER THE NORTHERN HALF OF THE AREA TO NEAR NORMAL OVER THE
SOUTHERN HALF OF THE AREA.
BY THURSDAY EVENING THE ENVIRONMENT SATURATES BEHIND THE MAIN TROUGH
AS ANOTHER WEAKER SHORT WAVE TROUGH DEVELOPS TO THE WEST. THIS
SECOND TROUGH WILL ALLOW SOME SMALL PRECIP. CHANCES FOR THE
AREA.
FRIDAY ANOTHER UPPER LEVEL RIDGE APPROACHES THE AREA PUSHING THE JET
STREAM AND MOISTURE NORTH OVER THE NORTHERN PLAINS. AHEAD OF THE
RIDGE A WARM FRONT WILL MOVE THROUGH THE AREA BRINGING TEMPERATURES
BACK TO NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1114 AM MDT SAT MAR 22 2014
LIGHT SNOW WILL GRADUALLY SPREAD SOUTH ACROSS THE AREA TODAY
ASSOCIATED WITH AN UPPER LEVEL DISTURBANCE MOVING OUT OF THE
NORTHERN PLAINS. AT 17Z...RADAR AND SURFACE OBSERVATIONS SHOW THE
LIGHT SNOW JUST ABOUT TO REACH KMCK WITH ASSOCIATED LOWER CIGS AND
SLIGHT VISIBILITY REDUCTIONS. WORST FLIGHT CATEGORIES AT KMCK
POTENTIALLY IN THE LATE AFTERNOON AND EARLY EVENING HOURS WITH THE
SNOW...THEN SLOWLY IMPROVING THROUGH TONIGHT. SNOW WILL REACH KGLD
LATER THIS AFTERNOON WITH SIMILAR FLIGHT CATEGORY RESTRICTIONS
THROUGH THE EARLY EVENING HOURS BEFORE SLOWLY IMPROVING DURING THE
OVERNIGHT HOURS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JTL
AVIATION...024
AREA FORECAST DISCUSSION
NWS GOODLAND KS
552 AM MDT SAT MAR 22 2014
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 422 AM MDT SAT MAR 22 2014
MAIN FORECAST CONCERN WILL BE CHANCE/AMOUNT OF SNOW THROUGH THE
WEEKEND...TEMPERATURE ROLLERCOASTER INTO MONDAY...AND WINDS ON
SUNDAY AND MONDAY. SATELLITE SHOWING AN AMPLIFIED/COMPLICATED FLOW
PATTERN OVER THE PACIFIC WHICH TRANSITIONS INTO A BROAD TROUGHINESS
AND PROGRESSIVE WESTERLY FLOW OVER THE COUNTRY. SEVERAL SHORTWAVE
TROUGHS EMBEDDED WITHIN THAT FLOW. ONE OF MAIN CONCERN IS TROUGH
MOVING ACROSS THE GREAT BASIN WITH STRONGEST PORTION OF THE TROUGH
MOVING INTO SOUTHERN IDAHO. NEXT SHORTWAVE TROUGH IS MOVING INTO
WESTERN CANADA. COLD FRONT MOVED THROUGH WITH A SECONDARY COLD
FRONT AND MUCH COLDER AIR APPROACHING FROM THE NORTH AT THIS TIME.
AT JET LEVEL...MODELS APPEARED TO INITIALIZE FINE. AT MID
LEVELS...PER SATELLITE AND UPPER AIR ANALYSIS THE NAM WAS DOING
SLIGHTLY BETTER THAN THE OTHER OUTPUT...ESPECIALLY THE UKMET AND
ECMWF...WITH THE SREF THE WORST. THE NAM WAS DOING A LITTLE BETTER
THAN THE ECWMF AND GFS ON THE SURFACE WIND AND PRESSURE FIELD.
THE MODELS WERE A LITTLE WARM WITH THE GFS DOING A LITTLE BETTER
THAN THE UKMET...NAM AND CANADIAN ON THE LOW LEVEL THERMAL FIELD.
TODAY/TONIGHT...MAIN JET LOOKS TO STAY NOT TOO FAR TO THE NORTH
THROUGH THE MORNING. HOWEVER...MODELS DIFFER ON THE SUBTLE BUT
IMPORTANT DETAILS OVER US. AS IT LOOKS NOW THE RIGHT REAR QUADRANT
OF THE NORTHERN JET LOOKS TO BE NEAR OR OVER THE NORTHERN PORTION
OF OUR AREA AT 18Z. THE TREND THE LAST TWO DAYS IS TOO KEEP THIS A
LITTLE FURTHER NORTH AND BE A LITTLE SLOWER IN ARRIVING INTO OUR
AREA. MODELS BRING THIS RIGHT REAR QUADRANT ACROSS THE FORECAST AREA
THROUGH THE AFTERNOON. BY LATE IN THE AFTERNOON THIS RIGHT REAR
QUADRANT IS NEAR THE SOUTHERN END OF THE FORECAST AREA. BY MID
EVENING THIS JET IS EAST OF THE AREA WITH SOME POSSIBLE WEAK JET
AROUND THROUGH 06Z.
ABOVE MENTIONED SHORTWAVE TROUGH IS ALSO SLOWER TO ARRIVE WITH IT
BEGINNING TO AFFECT THE AREA BY LATE MORNING AND MOVING ACROSS MOST
OF THE AREA BY LATE AFTERNOON. BY LATE AFTERNOON IS NEAR THE
SOUTHERN END OF THE FORECAST AREA AND ALSO MOVES OUT OF THE AREA AT
THE SAME SPEED THE JET DOES. NOW WHAT LOOKS TO BE OCCURRING ON
SATELLITE IS BEING SHOWN BY TONIGHTS MODEL OUTPUT. THIS INCOMING
TROUGH STARTING TO SPLIT WITH THE NORTHERN PORTION MOVING THROUGH PER
DISCUSSION ABOVE. THE SOUTHERN PORTION LOOKS TO BE GOING SOUTH AND
WEST OF MY AREA.
MODELS HAVE BEEN WAFFLING EVEN IN THE NEAR TERM ON HOW FAST AND HOW
FAR TO DEVELOP PRECIPITATION THIS MORNING. A VERY SMALL AREA OF
SNOW HAS MOVED ACROSS THE NORTHERN OF THE AREA IN CONJUNCTION WITH A
PRELIMINARY WEAK SHORTWAVE. HRRR AND RUC CATCH THIS NICELY AND
DISSIPATE BY 12Z. AS THE ABOVE MENTIONED SHORTWAVE TROUGH...WHICH
GETS CLOSER TO THE AREA BY LATE MORNING...AND UPPER JET GETS
CLOSER...MODELS START DEVELOPING PRECIPITATION OVER THE NORTHERN
HALF AND ESPECIALLY THE NORTHWEST CORNER OF THE AREA. THIS AREA OF
PRECIPITATION GROWS IN COVERAGE AND SINKS SOUTH AND WEST THROUGH
THE AFTERNOON.
BY LATE AFTERNOON INTO THE EARLY EVENING GREATEST CHANCE OF
PRECIPITATION IN THE FAR SOUTH AND SOUTHWEST WHERE THE GREATEST LOW
LEVEL UPSLOPE COMPONENTY RESIDES ALONG WITH THE RIGHT REAR QUADRANT
OF THE JET. AM A LITTLE CONCERNED THAT THE MODELS MAY BE CUTTING
OFF PRECIPITATION TOO SOON. A MID LEVEL BAROCLINIC ZONE/STRONG ZONE
OF NARROW FRONTOGENSIS DEVELOPS BEHIND THE EXITING SHORTWAVE TROUGH
AND JET. MODEL SOUNDINGS...EVEN FURTHER NORTH BEHIND THE MAIN LIFT...
STAY SATURATED REALLY CLOSE TO THE DENDRITIC ZONE INTO THE EVENING.
SO DID NOT REALLY START DECREASING THE PRECIPITATION UNTIL AFTER
MIDNIGHT.
PER ICE IN THE COLUMN AND VERY LOW WET BULB ZERO HEIGHTS...PHASE
SHOULD BE MOSTLY SNOW. HOWEVER...THE FAR SOUTH THAT SATURATES AND
COOLS LATER WILL STAY A MIXTURE FROM LATE AFTERNOON INTO EARLY
EVENING. DEFINITELY LOOKS LIKE 1 TO 2 INCHES WITH POSSIBLY 3
INCHES...MAINLY IN THE FAR WEST TO SOUTHWEST LOCATIONS...WILL OCCUR
WITH THIS SYSTEM.
MODELS DIFFER ON HOW WARM TEMPERATURES WILL GET. DUE TO THE THICK
CLOUD COVER...TEMPERATURES HAVE NOT COOLED AS MUCH THIS MORNING AS
WHAT THE MODELS THOUGHT. AGAIN TENDED TO FOLLOW THE COOLER GUIDANCE
DUE TO THE ABUNDANT CLOUD COVER AND STRENGTHENING LOW LEVEL UPSLOPE
AND COLD AIR ADVECTION.
SUNDAY/SUNDAY NIGHT...CLOUDS SHOULD CLEAR OUT BY LATE IN THE
MORNING. SURFACE RIDGE PULLS AWAY TO THE EAST WHILE ANOTHER LEE
TROUGH DEVELOPS TO OUR WEST AS A RESULT OF THE STRONG CROSS
MOUNTAIN FLOW. GRADIENT AND 3 HOUR PRESSURE FALLS WOULD INDICATE AT
LEAST BREEZY TO POSSIBLY WINDY CONDITIONS IN THE WESTERN HALF.
TEMPERATURES SHOULD BE WARMER BUT NOT SURE HOW MUCH. MODELS ARE
WARMER THAN THEY WERE YESTERDAY...ESPECIALLY THE NAM. DID WARM
TEMPERATURES A LITTLE BUT CONSIDERING THE LINGERING CLOUD COVER AND
RECYCLED COOL AIR...CHOSE TO GO CLOSER TO THE COOLER GUIDANCE.
DUE TO JET LIFT FROM JET SEGMENT IN ADVANCE OF NEXT INCOMING
SHORTWAVE TROUGH AND JET BEHIND THIS TROUGH COMBINED WITH A DECENT
MID LEVEL BAROCLINIC ZONE/FRONTOGENESIS AND THETA-E LAPSE RATES
NEAR ZERO WOULD DEFINITELY SUPPORT THE MENTION OF SOMEKIND OF
PRECIPITATION. MODELS ARE EVEN SHOWING A SMALL AMOUNT OF ELEVATED
CAPE. MODELS EVEN BRING A FAIRLY STRONG PV ANOMALY. PROBLEM IS ALL
THE MODEL SHOWING A DRY AND UNSATURATED AIR MASS. BUT CONSIDERING
THE AMOUNT OF LIFT AND INSTABILITY...DECIDED TO JUST MENTION
FLURRIES AFTER MIDNIGHT.
MONDAY/MONDAY NIGHT...NEXT COLD FRONT WILL THROUGH THE AREA LATE
SUNDAY NIGHT INTO EARLY MONDAY MORNING AS A RESULT OF THE ABOVE
MENTIONED SHORTWAVE TROUGH. MODELS ARE SHOWING DECENT LOW LEVEL
LAPSE RATES ALONG WITH MODERATE TO STRONG DOWNWARD MOTION. THERE
LOOKS TO BE UNIDIRECTION FLOW THROUGH NEARLY 700 MB. IT LOOKS LIKE
WE COULD GET WINDY...POSSIBLY NEAR WIND ADVISORY CRITERIA. THIS WILL
NEED TO BE CLOSELY WATCHED. TEMPERATURES SHOULD STILL BE WARM
DESPITE THE FRONTAL POSSIBLE PER PLENTY OF SUNSHINE AND PROGGED 850
MB TEMPERATURES.
ONLY THE ECMWF WAS SHOWING QPF FOR MONDAY NIGHT. HOWEVER IT LOOKS
LIKE THE MAIN LIFT IS NORTH AND EAST OF THE AREA WITH DRIER LOW
LEVELS. SO REMOVED THE SLIGHT CHANCE FROM THAT PERIOD. POSSIBLE IT
COULD JUST BE FLURRIES ONCE AGAIN.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 422 AM MDT SAT MAR 22 2014
THE TUESDAY THROUGH FRIDAY PERIOD WILL HAVE SEVERAL UPPER LEVEL
SHORT WAVE TROUGHS MOVE THROUGH. THE ONLY ONE OF CONSEQUENCE MOVES
THROUGH THE AREA THURSDAY AND THURSDAY NIGHT.
TUESDAY AN UPPER LEVEL RIDGE BEGINS BUILDING OVER THE AREA. AHEAD
OF THE RIDGE THE RIGHT ENTRANCE OF THE 500MB JET MOVES OVER THE
AREA. UNFORTUNATELY THE MODELS HAVE DRIED OUT THE ENVIRONMENT UNDER
THE RIGHT ENTRANCE REGION SO WILL KEEP THE DAY DAY. THE COLD FRONT
WHICH MOVES IN DURING THE EARLY MORNING WILL BE PUSHED BACK NORTH
DURING THE AFTERNOON.
WEDNESDAY THE UPPER LEVEL RIDGE WILL BE POSITIONED OVER THE AREA.
MODELS MOVE A SUBTLE SHORT WAVE TROUGH THROUGH THE PERIPHERY OF THE
RIDGE...BUT KEEP IT SOUTH OF THE AREA. THE RIDGE AND BREEZY
SOUTHWEST WINDS WILL ALLOW TEMPERATURES TO WARM ALMOST 20 DEGREES
ABOVE NORMAL. IN ADDITION THE GUSTY WINDS NEAR 25 MPH COMBINED WITH
RELATIVE HUMIDITIES OF LESS THAN 20 PERCENT MAY LEAD TO HAZARDOUS
FIRE WEATHER CONDITIONS.
WEDNESDAY NIGHT PRECIP. CHANCES RETURN TO THE AREA AHEAD OF A
STRONGER SHORT WAVE TROUGH THAT WILL MOVE THROUGH THURSDAY. MODELS
SHOW DRIER AIR MOVING IN FROM THE SOUTHWEST JUST AHEAD OF THE TROUGH
WHICH WILL LIMIT PRECIP. CHANCES TO THE NORTHERN HALF OF THE AREA.
THURSDAY A STRONGER UPPER LEVEL SHORT WAVE TROUGH MOVES THROUGH THE
AREA BEHIND THE EXITING RIDGE. MODELS DISAGREE WHEN THE TROUGH WILL
MOVE THROUGH...VARYING FROM THE AFTERNOON TO EARLY EVENING. PRECIP.
CHANCES WITH THE TROUGH DO NOT LOOK AS PROMISING AS YESTERDAY DUE TO
MODELS TRENDING TOWARD A MORE SHALLOW SHORT WAVE TROUGH...WHICH WILL
ALLOW THE DRIER AIR TO MOVE FURTHER NORTH OVER MOST OF THE AREA.
MEANWHILE NORTH WINDS WILL STRENGTHEN BEHIND THE COLD FRONT THAT
WILL MOVE THROUGH THE AREA. TEMPERATURES WILL RANGE FROM BELOW
NORMAL OVER THE NORTHERN HALF OF THE AREA TO NEAR NORMAL OVER THE
SOUTHERN HALF OF THE AREA.
BY THURSDAY EVENING THE ENVIRONMENT SATURATES BEHIND THE MAIN TROUGH
AS ANOTHER WEAKER SHORT WAVE TROUGH DEVELOPS TO THE WEST. THIS
SECOND TROUGH WILL ALLOW SOME SMALL PRECIP. CHANCES FOR THE
AREA.
FRIDAY ANOTHER UPPER LEVEL RIDGE APPROACHES THE AREA PUSHING THE JET
STREAM AND MOISTURE NORTH OVER THE NORTHERN PLAINS. AHEAD OF THE
RIDGE A WARM FRONT WILL MOVE THROUGH THE AREA BRINGING TEMPERATURES
BACK TO NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 547 AM MDT SAT MAR 22 2014
COMPLICATED SET OF TAFS. AT KGLD...MVFR CONDITIONS THROUGH A
MAJORITY OF THE PERIOD. SNOW IS NOT EXPECTED TO OCCUR HEAR UNTIL
LATE IN THE AFTERNOON. AS IT LOOKS NOW...ONCE THE SNOW ENDS...IFR
CEILINGS COULD OCCUR AFTER 06Z. GUSTY EASTERLY WINDS ARE EXPECTED
FROM THE LATER THIS MORNING INTO THE EVENING HOURS. AT KMCK...MVFR
CONDITIONS ARE EXPECTED THROUGH THE PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JTL
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
422 AM MDT SAT MAR 22 2014
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 422 AM MDT SAT MAR 22 2014
MAIN FORECAST CONCERN WILL BE CHANCE/AMOUNT OF SNOW THROUGH THE
WEEKEND...TEMPERATURE ROLLERCOASTER INTO MONDAY...AND WINDS ON
SUNDAY AND MONDAY. SATELLITE SHOWING AN AMPLIFIED/COMPLICATED FLOW
PATTERN OVER THE PACIFIC WHICH TRANSITIONS INTO A BROAD TROUGHINESS
AND PROGRESSIVE WESTERLY FLOW OVER THE COUNTRY. SEVERAL SHORTWAVE
TROUGHS EMBEDDED WITHIN THAT FLOW. ONE OF MAIN CONCERN IS TROUGH
MOVING ACROSS THE GREAT BASIN WITH STRONGEST PORTION OF THE TROUGH
MOVING INTO SOUTHERN IDAHO. NEXT SHORTWAVE TROUGH IS MOVING INTO
WESTERN CANADA. COLD FRONT MOVED THROUGH WITH A SECONDARY COLD
FRONT AND MUCH COLDER AIR APPROACHING FROM THE NORTH AT THIS TIME.
AT JET LEVEL...MODELS APPEARED TO INITIALIZE FINE. AT MID
LEVELS...PER SATELLITE AND UPPER AIR ANALYSIS THE NAM WAS DOING
SLIGHTLY BETTER THAN THE OTHER OUTPUT...ESPECIALLY THE UKMET AND
ECMWF...WITH THE SREF THE WORST. THE NAM WAS DOING A LITTLE BETTER
THAN THE ECWMF AND GFS ON THE SURFACE WIND AND PRESSURE FIELD.
THE MODELS WERE A LITTLE WARM WITH THE GFS DOING A LITTLE BETTER
THAN THE UKMET...NAM AND CANADIAN ON THE LOW LEVEL THERMAL FIELD.
TODAY/TONIGHT...MAIN JET LOOKS TO STAY NOT TOO FAR TO THE NORTH
THROUGH THE MORNING. HOWEVER...MODELS DIFFER ON THE SUBTLE BUT
IMPORTANT DETAILS OVER US. AS IT LOOKS NOW THE RIGHT REAR QUADRANT
OF THE NORTHERN JET LOOKS TO BE NEAR OR OVER THE NORTHERN PORTION
OF OUR AREA AT 18Z. THE TREND THE LAST TWO DAYS IS TOO KEEP THIS A
LITTLE FURTHER NORTH AND BE A LITTLE SLOWER IN ARRIVING INTO OUR
AREA. MODELS BRING THIS RIGHT REAR QUADRANT ACROSS THE FORECAST AREA
THROUGH THE AFTERNOON. BY LATE IN THE AFTERNOON THIS RIGHT REAR
QUADRANT IS NEAR THE SOUTHERN END OF THE FORECAST AREA. BY MID
EVENING THIS JET IS EAST OF THE AREA WITH SOME POSSIBLE WEAK JET
AROUND THROUGH 06Z.
ABOVE MENTIONED SHORTWAVE TROUGH IS ALSO SLOWER TO ARRIVE WITH IT
BEGINNING TO AFFECT THE AREA BY LATE MORNING AND MOVING ACROSS MOST
OF THE AREA BY LATE AFTERNOON. BY LATE AFTERNOON IS NEAR THE
SOUTHERN END OF THE FORECAST AREA AND ALSO MOVES OUT OF THE AREA AT
THE SAME SPEED THE JET DOES. NOW WHAT LOOKS TO BE OCCURRING ON
SATELLITE IS BEING SHOWN BY TONIGHTS MODEL OUTPUT. THIS INCOMING
TROUGH STARTING TO SPLIT WITH THE NORTHERN PORTION MOVING THROUGH PER
DISCUSSION ABOVE. THE SOUTHERN PORTION LOOKS TO BE GOING SOUTH AND
WEST OF MY AREA.
MODELS HAVE BEEN WAFFLING EVEN IN THE NEAR TERM ON HOW FAST AND HOW
FAR TO DEVELOP PRECIPITATION THIS MORNING. A VERY SMALL AREA OF
SNOW HAS MOVED ACROSS THE NORTHERN OF THE AREA IN CONJUNCTION WITH A
PRELIMINARY WEAK SHORTWAVE. HRRR AND RUC CATCH THIS NICELY AND
DISSIPATE BY 12Z. AS THE ABOVE MENTIONED SHORTWAVE TROUGH...WHICH
GETS CLOSER TO THE AREA BY LATE MORNING...AND UPPER JET GETS
CLOSER...MODELS START DEVELOPING PRECIPITATION OVER THE NORTHERN
HALF AND ESPECIALLY THE NORTHWEST CORNER OF THE AREA. THIS AREA OF
PRECIPITATION GROWS IN COVERAGE AND SINKS SOUTH AND WEST THROUGH
THE AFTERNOON.
BY LATE AFTERNOON INTO THE EARLY EVENING GREATEST CHANCE OF
PRECIPITATION IN THE FAR SOUTH AND SOUTHWEST WHERE THE GREATEST LOW
LEVEL UPSLOPE COMPONENTY RESIDES ALONG WITH THE RIGHT REAR QUADRANT
OF THE JET. AM A LITTLE CONCERNED THAT THE MODELS MAY BE CUTTING
OFF PRECIPITATION TOO SOON. A MID LEVEL BAROCLINIC ZONE/STRONG ZONE
OF NARROW FRONTOGENSIS DEVELOPS BEHIND THE EXITING SHORTWAVE TROUGH
AND JET. MODEL SOUNDINGS...EVEN FURTHER NORTH BEHIND THE MAIN LIFT...
STAY SATURATED REALLY CLOSE TO THE DENDRITIC ZONE INTO THE EVENING.
SO DID NOT REALLY START DECREASING THE PRECIPITATION UNTIL AFTER
MIDNIGHT.
PER ICE IN THE COLUMN AND VERY LOW WET BULB ZERO HEIGHTS...PHASE
SHOULD BE MOSTLY SNOW. HOWEVER...THE FAR SOUTH THAT SATURATES AND
COOLS LATER WILL STAY A MIXTURE FROM LATE AFTERNOON INTO EARLY
EVENING. DEFINITELY LOOKS LIKE 1 TO 2 INCHES WITH POSSIBLY 3
INCHES...MAINLY IN THE FAR WEST TO SOUTHWEST LOCATIONS...WILL OCCUR
WITH THIS SYSTEM.
MODELS DIFFER ON HOW WARM TEMPERATURES WILL GET. DUE TO THE THICK
CLOUD COVER...TEMPERATURES HAVE NOT COOLED AS MUCH THIS MORNING AS
WHAT THE MODELS THOUGHT. AGAIN TENDED TO FOLLOW THE COOLER GUIDANCE
DUE TO THE ABUNDANT CLOUD COVER AND STRENGTHENING LOW LEVEL UPSLOPE
AND COLD AIR ADVECTION.
SUNDAY/SUNDAY NIGHT...CLOUDS SHOULD CLEAR OUT BY LATE IN THE
MORNING. SURFACE RIDGE PULLS AWAY TO THE EAST WHILE ANOTHER LEE
TROUGH DEVELOPS TO OUR WEST AS A RESULT OF THE STRONG CROSS
MOUNTAIN FLOW. GRADIENT AND 3 HOUR PRESSURE FALLS WOULD INDICATE AT
LEAST BREEZY TO POSSIBLY WINDY CONDITIONS IN THE WESTERN HALF.
TEMPERATURES SHOULD BE WARMER BUT NOT SURE HOW MUCH. MODELS ARE
WARMER THAN THEY WERE YESTERDAY...ESPECIALLY THE NAM. DID WARM
TEMPERATURES A LITTLE BUT CONSIDERING THE LINGERING CLOUD COVER AND
RECYCLED COOL AIR...CHOSE TO GO CLOSER TO THE COOLER GUIDANCE.
DUE TO JET LIFT FROM JET SEGMENT IN ADVANCE OF NEXT INCOMING
SHORTWAVE TROUGH AND JET BEHIND THIS TROUGH COMBINED WITH A DECENT
MID LEVEL BAROCLINIC ZONE/FRONTOGENESIS AND THETA-E LAPSE RATES
NEAR ZERO WOULD DEFINITELY SUPPORT THE MENTION OF SOMEKIND OF
PRECIPITATION. MODELS ARE EVEN SHOWING A SMALL AMOUNT OF ELEVATED
CAPE. MODELS EVEN BRING A FAIRLY STRONG PV ANOMALY. PROBLEM IS ALL
THE MODEL SHOWING A DRY AND UNSATURATED AIR MASS. BUT CONSIDERING
THE AMOUNT OF LIFT AND INSTABILITY...DECIDED TO JUST MENTION
FLURRIES AFTER MIDNIGHT.
MONDAY/MONDAY NIGHT...NEXT COLD FRONT WILL THROUGH THE AREA LATE
SUNDAY NIGHT INTO EARLY MONDAY MORNING AS A RESULT OF THE ABOVE
MENTIONED SHORTWAVE TROUGH. MODELS ARE SHOWING DECENT LOW LEVEL
LAPSE RATES ALONG WITH MODERATE TO STRONG DOWNWARD MOTION. THERE
LOOKS TO BE UNIDIRECTION FLOW THROUGH NEARLY 700 MB. IT LOOKS LIKE
WE COULD GET WINDY...POSSIBLY NEAR WIND ADVISORY CRITERIA. THIS WILL
NEED TO BE CLOSELY WATCHED. TEMPERATURES SHOULD STILL BE WARM
DESPITE THE FRONTAL POSSIBLE PER PLENTY OF SUNSHINE AND PROGGED 850
MB TEMPERATURES.
ONLY THE ECMWF WAS SHOWING QPF FOR MONDAY NIGHT. HOWEVER IT LOOKS
LIKE THE MAIN LIFT IS NORTH AND EAST OF THE AREA WITH DRIER LOW
LEVELS. SO REMOVED THE SLIGHT CHANCE FROM THAT PERIOD. POSSIBLE IT
COULD JUST BE FLURRIES ONCE AGAIN.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 422 AM MDT SAT MAR 22 2014
THE TUESDAY THROUGH FRIDAY PERIOD WILL HAVE SEVERAL UPPER LEVEL
SHORT WAVE TROUGHS MOVE THROUGH. THE ONLY ONE OF CONSEQUENCE MOVES
THROUGH THE AREA THURSDAY AND THURSDAY NIGHT.
TUESDAY AN UPPER LEVEL RIDGE BEGINS BUILDING OVER THE AREA. AHEAD
OF THE RIDGE THE RIGHT ENTRANCE OF THE 500MB JET MOVES OVER THE
AREA. UNFORTUNATELY THE MODELS HAVE DRIED OUT THE ENVIRONMENT UNDER
THE RIGHT ENTRANCE REGION SO WILL KEEP THE DAY DAY. THE COLD FRONT
WHICH MOVES IN DURING THE EARLY MORNING WILL BE PUSHED BACK NORTH
DURING THE AFTERNOON.
WEDNESDAY THE UPPER LEVEL RIDGE WILL BE POSITIONED OVER THE AREA.
MODELS MOVE A SUBTLE SHORT WAVE TROUGH THROUGH THE PERIPHERY OF THE
RIDGE...BUT KEEP IT SOUTH OF THE AREA. THE RIDGE AND BREEZY
SOUTHWEST WINDS WILL ALLOW TEMPERATURES TO WARM ALMOST 20 DEGREES
ABOVE NORMAL. IN ADDITION THE GUSTY WINDS NEAR 25 MPH COMBINED WITH
RELATIVE HUMIDITIES OF LESS THAN 20 PERCENT MAY LEAD TO HAZARDOUS
FIRE WEATHER CONDITIONS.
WEDNESDAY NIGHT PRECIP. CHANCES RETURN TO THE AREA AHEAD OF A
STRONGER SHORT WAVE TROUGH THAT WILL MOVE THROUGH THURSDAY. MODELS
SHOW DRIER AIR MOVING IN FROM THE SOUTHWEST JUST AHEAD OF THE TROUGH
WHICH WILL LIMIT PRECIP. CHANCES TO THE NORTHERN HALF OF THE AREA.
THURSDAY A STRONGER UPPER LEVEL SHORT WAVE TROUGH MOVES THROUGH THE
AREA BEHIND THE EXITING RIDGE. MODELS DISAGREE WHEN THE TROUGH WILL
MOVE THROUGH...VARYING FROM THE AFTERNOON TO EARLY EVENING. PRECIP.
CHANCES WITH THE TROUGH DO NOT LOOK AS PROMISING AS YESTERDAY DUE TO
MODELS TRENDING TOWARD A MORE SHALLOW SHORT WAVE TROUGH...WHICH WILL
ALLOW THE DRIER AIR TO MOVE FURTHER NORTH OVER MOST OF THE AREA.
MEANWHILE NORTH WINDS WILL STRENGTHEN BEHIND THE COLD FRONT THAT
WILL MOVE THROUGH THE AREA. TEMPERATURES WILL RANGE FROM BELOW
NORMAL OVER THE NORTHERN HALF OF THE AREA TO NEAR NORMAL OVER THE
SOUTHERN HALF OF THE AREA.
BY THURSDAY EVENING THE ENVIRONMENT SATURATES BEHIND THE MAIN TROUGH
AS ANOTHER WEAKER SHORT WAVE TROUGH DEVELOPS TO THE WEST. THIS
SECOND TROUGH WILL ALLOW SOME SMALL PRECIP. CHANCES FOR THE
AREA.
FRIDAY ANOTHER UPPER LEVEL RIDGE APPROACHES THE AREA PUSHING THE JET
STREAM AND MOISTURE NORTH OVER THE NORTHERN PLAINS. AHEAD OF THE
RIDGE A WARM FRONT WILL MOVE THROUGH THE AREA BRINGING TEMPERATURES
BACK TO NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1146 PM MDT FRI MAR 21 2014
LOW STRATUS IS MOVING IN FROM THE NORTHEAST. KMCK IS NOW REPORTING
OVERCAST SKIES WITH A CEILING OF 2500 FT. THIS STRATUS SHOULD
CONTINUE SOUTHEAST AND EVENTUALLY INTO KGLD. GUIDANCE CONTINUES TO
PROJECT KGLD ON THE STRATUS EDGE SO HAVE ASSIGNED A TEMPO GROUP FOR
LOWER CEILINGS EARLY MORNING WITH CEILINGS LIFTING SOME LATE
MORNING. LOW CONFIDENCE IN PRECIP AND VISIBILITIES CONTINUES WITH
DRIER AIR AT SURFACE. OFF/ON LIGHT SNOW MAY PERSIST THROUGHOUT THE
DAY ONCE IT BEGINS AT KMCK. KGLD WILL BE ON THE EDGE SO DO NOT
MENTION SNOW UNTIL 23Z ONCE THE BETTER LIFT AND FRONTOGENESIS PASSES
OVER. EAST WINDS ARE EXPECTED THROUGHOUT TAF PERIOD AND SHOULD
BECOME GUSTY AT KGLD THIS AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JTL
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
743 PM EDT SUN MAR 23 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 329 PM EDT SUN MAR 23 2014
MUCH COLDER THAN NORMAL TEMPERATURES WILL CONTINUE THROUGH MID WEEK
BEFORE A MODERATING TREND DEVELOPS LATE IN THE WEEK. A WEAK CLIPPER
SYSTEM MONDAY NIGHT AND TUESDAY MAY PRODUCE SOME LIGHT SNOW
ACCUMULATIONS OF AN INCH OR TWO... LEADING TO A SLICK TUESDAY
MORNING COMMUTE. HIGH TEMPERATURES SHOULD BE UP NEAR 50 DEGREES ON
FRIDAY WITH THE POSSIBILITY OF A HALF INCH OR MORE OF RAIN.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 329 PM EDT SUN MAR 23 2014
THE FIRST FCST CHALLENGE IS WITH CLOUD TRENDS TONIGHT WHICH WILL
IMPACT OVERNIGHT LOW TEMPERATURES. THE OTHER FOCUS IN THE SHORT TERM
IS ON THE LIGHT SNOW EVENT FOR MONDAY NIGHT AND TUESDAY.
CONFIDENCE IS HIGH THAT INTERIOR SECTIONS OF THE CWFA WILL CLEAR OUT
AND SEE SINGLE DIGIT OVERNIGHT LOWS... WITH EVEN SOME BELOW ZERO
READINGS POSSIBLE AROUND LEOTA. HOWEVER WILL GO WITH MID TEENS FOR
LOWS ALONG THE LAKESHORE WHERE THE AMOUNT OF CLEARING IS SOMEWHAT
UNCERTAIN.
NAM/RAP LOW LEVEL RH PROGS ARE SUGGESTING THAT SOME LAKE CLOUDINESS
WILL PERSIST TONIGHT WEST AND NORTH OF GRR. GUIDANCE IS EVEN SHOWING
SOME VERY LIGHT QPF DEVELOPING OVERNIGHT AROUND MKG AND BIV AS A
VORT MAX APPROACHES FROM THE WEST. OF COURSE WORKING AGAINST ALL OF
THIS IS THE FACT THAT WE HAVE A VERY DRY AIR MASS IN PLACE AND A
SURFACE RIDGE IS BUILDING IN... WHICH CREATES SOME DOUBT ON THE
LIGHT SNOW SHOWER POTENTIAL.
SHORTWAVE DROPS DOWN FROM THE NORTHWEST FOR MONDAY NIGHT AND TUESDAY
BRINGING A REINFORCING SHOT OF ARCTIC AIR BEHIND IT FOR TUESDAY
NIGHT. ONE PV ANOMALY IS PROGGED TO IMPACT THE AREA LATE MONDAY
NIGHT WITH ANOTHER QUICKLY ON ITS HEELS TUESDAY MORNING. SOME LIGHT
LAKE EFFECT FOLLOWS IN THE WAKE OF THE SYSTEM TUESDAY AFTERNOON AND
EVENING. HOWEVER TOTAL ACCUMULATIONS FOR MONDAY NIGHT AND TUESDAY
SHOULD ONLY BE AROUND AN INCH... POSSIBLY UP TO TWO.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 329 PM EDT SUN MAR 23 2014
FAIR WX IS ANTICIPATED WEDNESDAY WITH HIGH PRESSURE IN CONTROL. MAX
TEMPS WILL REBOUND TO REACH THE 25 TO 30 DEGREE RANGE BY LATE
WEDNESDAY AFTERNOON WITH THE HELP OF STRONG LATE MARCH SUN AFTER A
VERY COLD BEGINNING TO THE DAY.
ISENTROPIC UPGLIDE WILL RESULT IN LIGHT SNOW DEVELOPING WEDNESDAY
NIGHT. A LOW PRESSURE SYSTEM WILL TRACK EAST THROUGH OUR REGION LATE
IN THE WEEK AND BRING RAIN SHOWERS OR MIXED RAIN AND SNOW SHOWERS.
TEMPS SHOULD CONTINUE TO AVERAGE AROUND FIVE TO TEN DEGREES BELOW
NORMAL BEHIND THAT SYSTEM INTO NEXT WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 743 PM EDT SUN MAR 23 2014
SKIES SHOULD BECOME NEARLY CLEAR AT ALL OF OUR TAF SITES BY 03Z AS
DAY TIME HEATING CONVECTION DISSIPATES. THIS TREND CAN ALREADY BE
SEEN ON THE LAST FEW VISIBLE IMAGE LOOPS OF LOWER MICHIGAN.
HOWEVER... THIS CLEARING OF THE CLOUDS WILL NOT LAST ALL NIGHT. A
SHORTWAVE UPSTREAM WILL BE MOVING OVER LAKE MICHIGAN AFTER 06Z AND
THAT WILL CAUSE WINDS TO BECOME MORE WESTERLY AT LOWER TO MID
LEVELS AND INCREASE INVERSION HEIGHTS TO NEAR 6000 FT AGL. THAT
WILL LEAD TO A PERIOD OF LIGHT SNOW SHOWERS (MVFR CIGS/VSBY)
MOVING INLAND FROM LAKE MICHIGAN AFTER 08Z... MOSTLY NORTH OF MKG.
THIS CAN BE SEEN CLEARLY LOOKING AT THE RAP MODEL LIFT IN THE DGZ
LAYER BETWEEN 08Z AND 16Z. IT SHOWS THE LIFT STARTING AROUND 06Z
OVER MID LAKE MICHIGAN THEN MOVING ON SHORE AROUND NEAR AND NORTH
OF MKG BY 10Z- 11Z. THE RH IN THIS LAYER INCREASES TO OVER 90 PCT
AS THE LIFT INCREASES. MEANWHILE INLAND OF THIS MOSTLY SINKING IS
SEEN BELOW 850 MB SO SKIES SHOULD FOR THE MOST PART BE CLEAR. THIS
AREA OF LIFT SPREADS ACROSS THE CWA (TO THE INLAND TAF SITES)
AFTER 12Z) SO ALL AREAS WILL BECOME CLOUDY (MVFR) BY 14-15Z.
&&
.HYDROLOGY...
ISSUED AT 329 PM EDT SUN MAR 23 2014
THE NEAR TERM FEATURES ONLY MINOR PRECIPITATION AMOUNTS MONDAY NIGHT
INTO TUESDAY MORNING. THIS EVENT WILL BE IN THE FORM OF SNOW WITH
ACCUMULATIONS GENERALLY TOTALING ONE TO TWO INCHES. TEMPERATURES
SHOULD REMAIN BELOW FREEZING THROUGH WEDNESDAY KEEPING MUCH OF THE
GROUND MOISTURE AND REMAINING SNOWPACK IN PLACE. RIVER ICE HAS
BECOME A NON ISSUE OVER THE LAST 48 HOURS WITH MOST RIVERS WIDE OPEN
AND FLOWING FREELY. THE OUTLOOK REMAINS RATHER OPTIMISTIC WITH ALL
THINGS CONSIDERED.
HOWEVER...CHANCES ARE INCREASING FOR A DECENT SYSTEM TO MOVE IN
THURSDAY AND FRIDAY. THE SYSTEM WILL BRING MUCH WARMER TEMPERATURES
AND THE TREND SUPPORTS ALL RAINFALL. TOTAL PRECIPITATION AMOUNTS
COULD POSSIBLY EXCEED A HALF INCH. MOST TRIBUTARIES SHOULD BE
RECEDING BY MIDWEEK BUT IT WILL BE SOMETHING TO WATCH AS THE
FORECAST EVOLVES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MEADE
SHORT TERM...MEADE
LONG TERM...LAURENS
AVIATION...WDM
HYDROLOGY...JAM
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
702 PM CDT SUN MAR 23 2014
.SYNOPSIS...
ISSUED AT 318 PM CDT SUN MAR 23 2014
A HIGH LATITUDE BLOCK CENTERED OVER ALASKA IS EXPECTED TO PERSIST
THROUGH THE NEXT 7 DAYS. THE BLOCK AND ASSOCIATED HIGH AMPLITUDE
FLOW OFF THE ARCTIC SHOULD SEND TWO STRONG ARCTIC HIGH PRESSURE
SYSTEMS THROUGH THE FCST AREA. A STORM COULD DEVELOP THURSDAY AHEAD
OF THE SECOND ARCTIC HIGH. A BRIEF WARM UP IS EXPECTED WEDNESDAY
AHEAD OF THIS POSSIBLE STORM.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 318 PM CDT SUN MAR 23 2014
SFC LOW PRESSURE FORMING ALONG AN ARCTIC FRONT STRETCHING FROM
BRITISH COLUMBIA TO DEEP SOUTH TEXAS TRACKS SOUTH TONIGHT AND DROPS
A WEAK REINFORCING COLD FRONT THROUGH THE FCST AREA OVERNIGHT. THE
MODELS INCLUDING THE HRRR AND RAP ARE SPLITTING THE UPPER LEVEL
ENERGY THROUGH THE MISSOURI BASIN AND THE CNTL ROCKIES PRODUCING
JUST SCATTERED SNOW SHOWERS AHEAD AND BEHIND THE FRONT. THE RESULT
IS A WELL MIXED ATMOSPHERE TONIGHT AND MONDAY KEEPING LOWS ON THE
WARM SIDE TONIGHT AND HIGHS COOL MONDAY.
THE BEST GUESS ON LOWS TONIGHT IS 20S AND HIGHS MONDAY IN THE 30S TO
LOWER 40S. THE RAP WHICH HAS BEEN SHOWING GOOD SKILL WITH THE
TRAPPED MOISTURE AND STRATUS TODAY LIFTS THESE CLOUDS NORTH INTO THE
ARCTIC FRONT TONIGHT FOR MOSTLY CLOUDY CONDITIONS. THE NAM THEN
MIXES THESE LOW CLOUDS OUT MONDAY AFTN WHILE REDEVELOPING SNOW
SHOWERS MONDAY AFTN ACROSS NRN NEB AS A SECOND STRONGER SURGE OF
ARCTIC AIR DESCENDS THROUGH THE NRN HIGH PLAINS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 318 PM CDT SUN MAR 23 2014
AN ACTIVE PATTERN WILL PERSIST MONDAY NIGHT THROUGH THURSDAY AS
NORTHWEST FLOW THROUGH TUESDAY TRANSITIONS INTO ZONAL TO SOUTHWEST
FLOW WEDNESDAY INTO THURSDAY. A STORM SYSTEM WILL AFFECT THE
REGION WEDNESDAY NIGHT AND THURSDAY. IN ADDITION...BELOW TO MUCH
BELOW AVERAGE TEMPERATURES WILL PERSIST TUESDAY AS MODIFIED
ARCTIC HIGH PRESSURE BUILDS INTO THE MIDWEST.
MONDAY NIGHT...A REINFORCING COLD FRONT WILL BRING MODIFIED
ARCTIC AIR IN. A STALLED FRONT NEAR THE FRONT RANGE WILL BRING
WIDESPREAD STRATUS ALONG THE ADJACENT HIGH PLAINS. A WEAK
DISTURBANCE LOOKS SUFFICIENT FOR FLURRIES POSSIBLE ACROSS THE
PANHANDLE INTO SWRN NEBR OVERNIGHT. ON TUESDAY...A RETURN SOUTHERLY
FLOW WILL DEVELOP. HOWEVER WITH H85 TEMPS ONLY RISING TO NEAR -7C
IN THE NORTHEAST...HIGHS ONLY IN THE MID 30S EXPECTED...WHILE THE
WEST AND SOUTHWEST SHOULD SEE HIGHS IN THE LOWER TO MID 40S.
MUCH...MUCH WARMER ON WEDNESDAY FROM THE MID 60S TO LOWER 70S AHEAD
OF ANOTHER COLD FRONT. MEDIUM RANGE MODELS CONTINUE TO SHOW
DIFFERENCES WITH STORM SYSTEM WEDNESDAY NIGHT AND THURSDAY. THE
GFS CONTINUES TO FORECAST A FAST MOVING OPEN WAVE...WHILE THE
ECMWF AND GEM INDICATE A CLOSED LOW AND TROWEL DEVELOPING. THE
ECMWF HAS REMAINED VERY CONSISTENT THE PAST 3 RUNS AND PREFER ITS
SOLUTION BEST. THEREFORE POPS RAISED SLIGHTLY TO 40-50 PERCENT
WITH SNOW SUPPORTED IN THE NCTRL AND RAIN IN THE SOUTH. FALLING
TEMPS AND WET BULB TEMPS THROUGH THE DAY SUPPORT SNOW CHANCES.
NORTH WINDS OF 20 TO 30 MPH ARE ALSO FORECAST. DESPITE MODEL
DIFFERENCES...WILL NEED TO CLOSELY MONITOR THIS SYSTEM...SINCE IT
HAS THE POTENTIAL TO BECOME A SPRING SNOW STORM IN THE REGION.
DRY FRIDAY THROUGH SUNDAY AS A BROAD RIDGE WILL BECOME ESTABLISHED
ACROSS THE REGION. TEMPERATURES WILL WARM TO THE 60S TO LOW 70S BY
THE WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 702 PM CDT SUN MAR 23 2014
AN ARCTIC COLD FRONT WILL PUSH INTO WESTERN AND NORTH CENTRAL
NEBRASKA...RESULTING IN ABUNDANT LOW AND MID LEVEL CLOUDINESS OVER
THE NEXT 24 HOURS. FOR THE KLBF TERMINAL...EXPECT SCATTERED CLOUDS
AON 3000 FT AGL THROUGH 16Z MONDAY WITH BROKEN TO OVERCAST SKIES
EXPECTED THEREAFTER. WINDS AT THE KLBF TERMINAL WILL BE FROM THE
SOUTH AT 10 KTS THROUGH 09Z MONDAY...SHIFTING TO THE NORTH
AT 10 TO 20 KTS THERE AFTER. FOR THE KVTN TERMINAL...EXPECT BROKEN
TO OVERCAST CIGS AON 2500 FT AGL THROUGH 04Z MONDAY. CIGS WILL
LOWER TO AROUND 1000 FT AGL THROUGH MIDDAY MONDAY...BEFORE
INCREASING TO AROUND 2500 FT AGL MONDAY AFTERNOON. WINDS WILL SHIFT
TO THE NORTH BY LATE EVENING...INCREASING TO 10 TO 20 KTS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CDC
SHORT TERM...CDC
LONG TERM...ROBERG
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS RALEIGH NC
900 PM EDT SUN MAR 23 2014
.SYNOPSIS... AN ARCTIC COLD FRONT WILL PUSH SOUTH THROUGH THE AREA
TONIGHT... BRINGING CHILLY HIGH PRESSURE INTO THE REGION FOR MONDAY.
A LOW PRESSURE SYSTEM WILL MOVE NORTHWARD JUST OFF THE EAST COAST
MONDAY NIGHT THROUGH TUESDAY. HIGH PRESSURE WILL BUILD IN FROM THE
WEST WEDNESDAY THROUGH THURSDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 900 PM SUNDAY...
UPDATE...
AREAS OF LOCALLY DENSE FOG ARE DEVELOPING ACROSS THE
PIEDMONT THIS EVENING...BETWEEN THE DEPARTING PRECIP TO THE EAST AND
THE APPROACHING PUSH OF DRIER AIR WITH THE COLD FRONT JUST WEST OF
THE CWA. THE DRY IS VERY SLOWLY MOVING ACROSS THE MOUNTAINS...BUT
SHOULD REALLY BEGIN TO SURGE EAST BY MIDNIGHT WITH DEWPOINTS
CRASHING INTO THE 20S. WE HAVE ISSUED A SPECIAL WEATHER STATEMENT
INSTEAD OF A DENSE FOG ADVISORY DUE TO THE EXPECTED BREVITY OF THE
FOG.
WE ALSO PLAN TO ISSUE A SPECIAL WEATHER STATEMENT FOR POSSIBLE BLACK
ICE IN THE MORNING. WHILE ROADS APPEAR TO BE DRIER IN THE TRIAD
AREA...THERE IS STILL MOISTURE ON THE ROADS HERE IN RALEIGH...AND
ROADS ARE LIKELY STILL WET NORTH AND EAST OF THE TRIANGLE. WITH
TEMPS EXPECTED TO DROP INTO THE UPPER 20S IN MOST AREAS NORTH OF
HIGHWAY 64...THERE COULD BE A FEW SLICK SPOTS IN THE MORNING. ITS
ALWAYS A TOUGH CALL ON HOW QUICKLY ROADS WILL DRY OUT WITH DRY AIR
ADVECTING IN OVERNIGHT. -SMITH
MONDAY: SURFACE HIGH PRESSURE WILL MOVE ACROSS THE AREA ON MONDAY
YIELDING A MOSTLY SUNNY DAY. GIVEN WE ARE EXPECTING AFTERNOON LOW
LEVEL THICKNESS VALUES TO BE SOME 40-45 METERS BELOW NORMAL
THOUGH... HIGH TEMPS SHOULD BE AROUND 15 TO 20 DEGREES BELOW NORMAL.
THIS YIELDS HIGH TEMPS RANGING FROM THE MID 40S NE TO THE LOWER 50S
SOUTH AND WEST.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 320 PM SUNDAY...
SFC RIDGE THAT EXTENDS ACROSS THE FORECAST AREA LATE MONDAY SCOOTS
QUICKLY MONDAY EVENING. THIS WILL ALLOW A WEAK RETURN SLY FLOW TO
SET-UP OVER CENTRAL NC. MEANWHILE A S/W IN THE NORTHERN STREAM WILL
AMPLIFY THE L/W TROUGH...PRODUCING 50-70M HEIGHTS FALLS OVER CENTRAL
NC BY 12Z TUESDAY. THE LIFT ASSOCIATED WITH THE HEIGHT FALLS PLUS A
MOISTENING ATMOSPHERE SHOULD CAUSE AREAS OF LIGHT PRECIP TO DEVELOP
AROUND DAYBREAK. THE APPROACH OF THE S/W WILL INDUCE LOW LEVEL
CYCLOGENESIS OFFSHORE OVER THE GULF STREAM. THIS FEATURE SHOULD
ADVECT LOW LEVEL ATLANTIC MOISTURE BACK INTO NE NC...POSSIBLY AS FAR
WEST AS THE COASTAL PLAIN-NE PIEDMONT OF CENTRAL NC. THIS MOISTURE
TRANSPORT CEASES BY 18Z. THUS...APPEARS THAT PRECIP CHANCES WILL
BEGIN TO DWINDLE FROM THE WEST BY 18Z...DIMINISHING IN THE FAR NE BY
SUNSET.
THERMAL PROFILES/MODEL SOUNDINGS SUGGEST THAT THE LOWER LEVELS OF
THE ATMOSPHERE WILL BE TOO WARM TO SUPPORT SNOW FOR MOST OF CENTRAL
NC. THE EXCEPTION WILL BE THE PIEDMONT TO THE WEST-NW OF RALEIGH
WHERE EVAPORATIVE COOLING MAY COOL THE COLUMN DOWN ENOUGH TO SUPPORT
LIGHT SNOW OR SNOW/RAIN MIX EARLY TUESDAY MORNING (BETWEEN 5 AM-10
AM). ONLY IN PATCHES WHERE MODERATE PRECIP INTENSITY OCCURS WILL
SNOW BE THE PRE-DOMINATE P-TYPE BUT IT IS LOOKING LESS LIKELY THAT
THIS WILL OCCUR. SINCE CURRENTLY EXPECTING NO WORSE THAN SNOW/RAIN
MIX...DO NOT ANTICIPATE MUCH IF ANY IMPACTS FROM THIS WEATHER EVENT.
IF A WORSE CASE SCENARIO WERE TO OCCUR...IT WOULD BE LIMITED TO A
NARROW BAND OF SNOW THAT MAY ACCUMULATE BRIEFLY AS A DUSTING ON
GRASSY SURFACES OR THE TOP OF CARS. AS THE AIR MASS WARMS THANKS TO
LOW LEVEL SELY FLOW...PRECIP SHOULD BE ALL RAIN ACROSS THE ENTIRE
FORECAST AREA BY LATE MORNING.
WITH THE PASSAGE OF THE SFC FRONT TUESDAY AFTERNOON...MAY SEE A BAND
OF SHOWERS/TOP TOPPED CONVECTION AS MID LEVEL LAPSE RATES STEEPEN IN
RESPONSE TO NEGATIVE TILT OF UPPER TROUGH. COULD HEAR A RUMBLE OR
TWO OF THUNDER. WITH THE FREEZING LEVEL RATHER LOW...MAY SEE SMALL
HAIL OR GRAUPEL WITH THE HEAVIER SHOWERS.
AS THE SFC LOW DEEPENS RAPIDLY OFF THE NC/DELMARVA COAST...BLUSTERY
NW SFC WINDS WILL OCCUR ACROSS CENTRAL NC TUESDAY AFTERNOON AND
THESE BLUSTERY WINDS WILL LIKELY PERSIST WELL INTO TUESDAY NIGHT.
SUSTAINED WINDS AROUND 15 MPH WITH GUSTS 25-30 MPH WILL BE COMMON.
THIS WIND FLOW WILL ALSO USHER MUCH COLDER DRIER AIR INTO CENTRAL
NC. TEMPS BY EARLY WEDNESDAY MORNING WILL BE IN THE 20S TO AROUND
30. THESE TEMPERATURES COMBINED WITH THE WIND WILL PRODUCE WIND
CHILL VALUES IN THE UPPER TEENS TO THE LOWER 20S.
HAVE HAD TO ADJUST MAX TEMPS UP SEVERAL DEGREES FROM PREVIOUS
FORECAST BUT AM STILL SEVERAL DEGREES BELOW MOS GUIDANCE. MAX TEMPS
TUESDAY MID 40S NORTH TO AROUND 50 SOUTH.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 320 PM SUNDAY...
WEDNESDAY THROUGH THURSDAY NIGHT...WINDY CONDITIONS EARLY WEDNESDAY
WILL ABATE DURING THE DAY AS THE SFC HIGH SETTLES OVER THE CAROLINAS
AND DEEP/STRONG SFC LOW OVER THE CANADIAN MARITIME MOVES FARTHER
AWAY. COLD AIR WILL SETTLE INTO THE REGION AS LOW LEVEL THICKNESSES
PROJECTED TO BE AS MUCH AS 50-60M BELOW NORMAL. THIS SUGGEST TEMPS
AS MUCH AS 15-20 DEGREES BELOW NORMAL. THIS YIELDS AFTERNOON TEMPS
MID-UPPER 40S. WITH THE HIGH OVERHEAD WEDNESDAY NIGHT AND A COLD DRY
AIR MASS IN PLACE...MIN TEMPS WEDNESDAY NIGHT IN THE MID-UPPER 20S.
COULD SEE A FEW PLACES GET AS COLD AS THE LOWER 20S. AIR MASS
MODIFIES THURSDAY AND THURSDAY NIGHT RESULTING IN MILDER CONDITIONS
BUT STILL BELOW NORMAL. HIGH TEMPS THURSDAY IN THE MID-UPPER 50S.
MIN TEMPS THURSDAY NIGHT IN THE 40S DUE TO INCREASING CLOUDINESS AND
A LIGHT SLY WIND AHEAD OF THE NEXT FRONTAL SYSTEM.
FRIDAY...MODEL GUIDANCE DIFFER A BIT ON THE STRENGTH OF A S/W RIDGE
OVER THE SE U.S. FRIDAY. 00Z ECMWF A LITTLE MORE DISTINCT WITH THIS
FEATURE WHILE GFS FLATTER AND MORE PROGRESSIVE. SINCE GFS HAS A
HISTORY OF MOVING MID-UPPER LEVEL RIDGE TOO QUICKLY EAST...ECMWF MAY
BE MORE CORRECT IN HOLDING ONTO THE RIDGE A LITTLE LONGER. THIS
FEATURE MAY RETARD THE EWD PROGRESSION OF A NORTHERN STREAM S/W
ACROSS THE GREAT LAKES INTO SOUTHERN ONTARIO AND ATTENDANT SFC FRONT
INTO THE CAROLINAS. BASED ON ABOVE ANALOGY...EXPECT BEST CHANCES FOR
SHOWERS ACROSS CENTRAL NC AHEAD OF THE SFC FRONT FRIDAY AFTERNOON
INTO FRIDAY NIGHT.
L/W TROUGH PROJECTED TO DIG/AMPLIFY ALONG THE EASTERN SEABOARD
SATURDAY. THIS MAY CAUSE THE UNSETTLED WEATHER PATTERN TO PERSIST
INTO THE FIRST HALF OF SATURDAY WITH IMPROVING WEATHER CONDITIONS
LATE SATURDAY INTO SUNDAY. SFC HIGH BUILDING INTO THE CAROLINAS
APPEARS TO BE OF CANADIAN ORIGIN WHICH SUGGEST THAT TEMPS WILL
AVERAGE A CATEGORY OR TWO BELOW NORMAL. HIGHS FRIDAY AND SATURDAY IN
THE 60S...COOLING INTO THE UPPER 50S AND LOWER 60S SUNDAY. OVERNIGHT
TEMPS IN THE 50S FRIDAY NIGHT AHEAD OF THE FRONTAL PASSAGE...AND 40-
45 SATURDAY NIGHT.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 810 PM SUNDAY...
THE DISTURBANCE WHICH HAS BROUGHT ADVERSE AVIATION WEATHER TODAY
WILL BE SHIFTING EAST OF CENTRAL NC BY MIDNIGHT. VFR CONDITIONS HAVE
ALREADY SWEPT INTO INT/GSO AS CHILLY HIGH PRESSURE BUILDS IN FROM
THE NORTHWEST... AND AFTER A FEW MORE HOURS OF MVFR CIGS/VSBYS AT
RDU/RWI/FAY... VFR CONDITIONS ARE EXPECTED TO RETURN BRIEFLY AFTER
03Z. THEN... A BATCH OF MVFR CLOUDS NOW OVER ERN VA IS EXPECTED TO
DROP SOUTHWARD BETWEEN 04Z AND 10Z... AFFECTING RDU/RWI/FAY DURING
THIS TIME FRAME (AS SUPPORTED BY THE HRRR MODEL OUTPUT)... ALTHOUGH
THIS MAY NOT BE A PREVAILING CONDITION. AFTER 10Z... VFR CONDITIONS
ARE EXPECTED ACROSS ALL OF CENTRAL NC... LASTING THROUGH THE END OF
THE TAF VALID PERIOD (00Z TUE). WINDS WILL BE FROM THE NORTH OR NNE
TONIGHT... SHIFTING TO MAINLY NORTHEASTERLY AT ALL SITES MONDAY
MORNING.
LOOKING BEYOND 00Z TUE (MID-EVENING MON): VFR CONDITIONS EXPECTED TO
HOLD THROUGH MON NIGHT... ALTHOUGH CLOUDS WILL BE SPREADING INTO
CENTRAL NC STARTING MON EVENING WITH CIGS THICKENING AND LOWERING
OVERNIGHT. A PASSING UPPER DISTURBANCE AND LOW PRESSURE FORMING OFF
THE COAST WILL BRING MVFR/IFR CIGS FROM AROUND SUNRISE TUE THROUGH
LATE AFTERNOON... WITH A CHANCE OF LIGHT RAIN (MAY BE MIXED WITH
LIGHT SNOW AT GSO/INT/RDU/RWI) THAT COULD BRING MVFR VSBYS. CIGS
WILL LIKELY RISE TO VFR FROM WEST TO EAST IN THE LATE AFTERNOON WITH
A CHANCE OF A RAIN SHOWER. BRISK WINDS FROM THE NW MAY POSE A
CROSSWIND THREAT AT GSO/RDU/RWI/FAY TUE AFTERNOON. VFR CONDITIONS
LIKELY TUE NIGHT THROUGH THURSDAY WITH HIGH PRESSURE BUILDING OVER
THE REGION. SUB-VFR CONDITIONS EXPECTED THU NIGHT INTO FRI WITH
INCREASING SW FLOW AHEAD OF AN APPROACHING FRONTAL SYSTEM. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...BSD/SMITH
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
810 PM EDT SUN MAR 23 2014
.SYNOPSIS... AN ARCTIC COLD FRONT WILL PUSH SOUTH THROUGH THE AREA
TONIGHT... BRINGING CHILLY HIGH PRESSURE INTO THE REGION FOR MONDAY.
A LOW PRESSURE SYSTEM WILL MOVE NORTHWARD JUST OFF THE EAST COAST
MONDAY NIGHT THROUGH TUESDAY. HIGH PRESSURE WILL BUILD IN FROM THE
WEST WEDNESDAY THROUGH THURSDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 3 PM SUNDAY...
REST OF TODAY AND TONIGHT: AN AREA OF RAIN ASSOCIATED WITH A FAST
MOVING MID LEVEL DISTURBANCE IS CURRENTLY MOVING ACROSS CENTRAL NC
THIS AFTERNOON. THIS AREA OF RAIN WILL SHIFT TO THE EAST OF THE AREA
BY THIS EVENING... WITH CLEARING SKIES EXPECTED BY TONIGHT AS ARCTIC
HIGH PRESSURE WILL BUILD INTO THE CENTRAL NC. GUIDANCE SHOWS
DEWPOINTS FALLING INTO THE 20S AND EVEN THE TEENS OVERNIGHT. THIS
COUPLED WITH AT LEAST SOME WIND OVERNIGHT SHOULD PREVENT MUCH IN THE
WAY OF ANY BLACK ICE. HOWEVER... TEMPS ARE EXPECTED TO FALL INTO THE
MID TO UPPER 20S... WITH A FEW LOCATIONS IN THE LOWER 30S ACROSS THE
SOUTH FOR LOWS. THUS... ANY LOCATIONS THAT ARE ABLE TO DECOUPLE AND
NOT COMPLETELY DRY OUT COULD POSSIBLY SEE A FEW PATCHES OF BLACK ICE
FORM (MAINLY ELEVATED SURFACES)... ALTHOUGH EXPECT MOST LOCATIONS TO
DRY OUT OVERNIGHT BEFORE TEMPS FALL BELOW FREEZING.
MONDAY: SURFACE HIGH PRESSURE WILL MOVE ACROSS THE AREA ON MONDAY
YIELDING A MOSTLY SUNNY DAY. GIVEN WE ARE EXPECTING AFTERNOON LOW
LEVEL THICKNESS VALUES TO BE SOME 40-45 METERS BELOW NORMAL
THOUGH... HIGH TEMPS SHOULD BE AROUND 15 TO 20 DEGREES BELOW NORMAL.
THIS YIELDS HIGH TEMPS RANGING FROM THE MID 40S NE TO THE LOWER 50S
SOUTH AND WEST.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 320 PM SUNDAY...
SFC RIDGE THAT EXTENDS ACROSS THE FORECAST AREA LATE MONDAY SCOOTS
QUICKLY MONDAY EVENING. THIS WILL ALLOW A WEAK RETURN SLY FLOW TO
SET-UP OVER CENTRAL NC. MEANWHILE A S/W IN THE NORTHERN STREAM WILL
AMPLIFY THE L/W TROUGH...PRODUCING 50-70M HEIGHTS FALLS OVER CENTRAL
NC BY 12Z TUESDAY. THE LIFT ASSOCIATED WITH THE HEIGHT FALLS PLUS A
MOISTENING ATMOSPHERE SHOULD CAUSE AREAS OF LIGHT PRECIP TO DEVELOP
AROUND DAYBREAK. THE APPROACH OF THE S/W WILL INDUCE LOW LEVEL
CYCLOGENESIS OFFSHORE OVER THE GULF STREAM. THIS FEATURE SHOULD
ADVECT LOW LEVEL ATLANTIC MOISTURE BACK INTO NE NC...POSSIBLY AS FAR
WEST AS THE COASTAL PLAIN-NE PIEDMONT OF CENTRAL NC. THIS MOISTURE
TRANSPORT CEASES BY 18Z. THUS...APPEARS THAT PRECIP CHANCES WILL
BEGIN TO DWINDLE FROM THE WEST BY 18Z...DIMINISHING IN THE FAR NE BY
SUNSET.
THERMAL PROFILES/MODEL SOUNDINGS SUGGEST THAT THE LOWER LEVELS OF
THE ATMOSPHERE WILL BE TOO WARM TO SUPPORT SNOW FOR MOST OF CENTRAL
NC. THE EXCEPTION WILL BE THE PIEDMONT TO THE WEST-NW OF RALEIGH
WHERE EVAPORATIVE COOLING MAY COOL THE COLUMN DOWN ENOUGH TO SUPPORT
LIGHT SNOW OR SNOW/RAIN MIX EARLY TUESDAY MORNING (BETWEEN 5 AM-10
AM). ONLY IN PATCHES WHERE MODERATE PRECIP INTENSITY OCCURS WILL
SNOW BE THE PRE-DOMINATE P-TYPE BUT IT IS LOOKING LESS LIKELY THAT
THIS WILL OCCUR. SINCE CURRENTLY EXPECTING NO WORSE THAN SNOW/RAIN
MIX...DO NOT ANTICIPATE MUCH IF ANY IMPACTS FROM THIS WEATHER EVENT.
IF A WORSE CASE SCENARIO WERE TO OCCUR...IT WOULD BE LIMITED TO A
NARROW BAND OF SNOW THAT MAY ACCUMULATE BRIEFLY AS A DUSTING ON
GRASSY SURFACES OR THE TOP OF CARS. AS THE AIR MASS WARMS THANKS TO
LOW LEVEL SELY FLOW...PRECIP SHOULD BE ALL RAIN ACROSS THE ENTIRE
FORECAST AREA BY LATE MORNING.
WITH THE PASSAGE OF THE SFC FRONT TUESDAY AFTERNOON...MAY SEE A BAND
OF SHOWERS/TOP TOPPED CONVECTION AS MID LEVEL LAPSE RATES STEEPEN IN
RESPONSE TO NEGATIVE TILT OF UPPER TROUGH. COULD HEAR A RUMBLE OR
TWO OF THUNDER. WITH THE FREEZING LEVEL RATHER LOW...MAY SEE SMALL
HAIL OR GRAUPEL WITH THE HEAVIER SHOWERS.
AS THE SFC LOW DEEPENS RAPIDLY OFF THE NC/DELMARVA COAST...BLUSTERY
NW SFC WINDS WILL OCCUR ACROSS CENTRAL NC TUESDAY AFTERNOON AND
THESE BLUSTERY WINDS WILL LIKELY PERSIST WELL INTO TUESDAY NIGHT.
SUSTAINED WINDS AROUND 15 MPH WITH GUSTS 25-30 MPH WILL BE COMMON.
THIS WIND FLOW WILL ALSO USHER MUCH COLDER DRIER AIR INTO CENTRAL
NC. TEMPS BY EARLY WEDNESDAY MORNING WILL BE IN THE 20S TO AROUND
30. THESE TEMPERATURES COMBINED WITH THE WIND WILL PRODUCE WIND
CHILL VALUES IN THE UPPER TEENS TO THE LOWER 20S.
HAVE HAD TO ADJUST MAX TEMPS UP SEVERAL DEGREES FROM PREVIOUS
FORECAST BUT AM STILL SEVERAL DEGREES BELOW MOS GUIDANCE. MAX TEMPS
TUESDAY MID 40S NORTH TO AROUND 50 SOUTH.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 320 PM SUNDAY...
WEDNESDAY THROUGH THURSDAY NIGHT...WINDY CONDITIONS EARLY WEDNESDAY
WILL ABATE DURING THE DAY AS THE SFC HIGH SETTLES OVER THE CAROLINAS
AND DEEP/STRONG SFC LOW OVER THE CANADIAN MARITIME MOVES FARTHER
AWAY. COLD AIR WILL SETTLE INTO THE REGION AS LOW LEVEL THICKNESSES
PROJECTED TO BE AS MUCH AS 50-60M BELOW NORMAL. THIS SUGGEST TEMPS
AS MUCH AS 15-20 DEGREES BELOW NORMAL. THIS YIELDS AFTERNOON TEMPS
MID-UPPER 40S. WITH THE HIGH OVERHEAD WEDNESDAY NIGHT AND A COLD DRY
AIR MASS IN PLACE...MIN TEMPS WEDNESDAY NIGHT IN THE MID-UPPER 20S.
COULD SEE A FEW PLACES GET AS COLD AS THE LOWER 20S. AIR MASS
MODIFIES THURSDAY AND THURSDAY NIGHT RESULTING IN MILDER CONDITIONS
BUT STILL BELOW NORMAL. HIGH TEMPS THURSDAY IN THE MID-UPPER 50S.
MIN TEMPS THURSDAY NIGHT IN THE 40S DUE TO INCREASING CLOUDINESS AND
A LIGHT SLY WIND AHEAD OF THE NEXT FRONTAL SYSTEM.
FRIDAY...MODEL GUIDANCE DIFFER A BIT ON THE STRENGTH OF A S/W RIDGE
OVER THE SE U.S. FRIDAY. 00Z ECMWF A LITTLE MORE DISTINCT WITH THIS
FEATURE WHILE GFS FLATTER AND MORE PROGRESSIVE. SINCE GFS HAS A
HISTORY OF MOVING MID-UPPER LEVEL RIDGE TOO QUICKLY EAST...ECMWF MAY
BE MORE CORRECT IN HOLDING ONTO THE RIDGE A LITTLE LONGER. THIS
FEATURE MAY RETARD THE EWD PROGRESSION OF A NORTHERN STREAM S/W
ACROSS THE GREAT LAKES INTO SOUTHERN ONTARIO AND ATTENDANT SFC FRONT
INTO THE CAROLINAS. BASED ON ABOVE ANALOGY...EXPECT BEST CHANCES FOR
SHOWERS ACROSS CENTRAL NC AHEAD OF THE SFC FRONT FRIDAY AFTERNOON
INTO FRIDAY NIGHT.
L/W TROUGH PROJECTED TO DIG/AMPLIFY ALONG THE EASTERN SEABOARD
SATURDAY. THIS MAY CAUSE THE UNSETTLED WEATHER PATTERN TO PERSIST
INTO THE FIRST HALF OF SATURDAY WITH IMPROVING WEATHER CONDITIONS
LATE SATURDAY INTO SUNDAY. SFC HIGH BUILDING INTO THE CAROLINAS
APPEARS TO BE OF CANADIAN ORIGIN WHICH SUGGEST THAT TEMPS WILL
AVERAGE A CATEGORY OR TWO BELOW NORMAL. HIGHS FRIDAY AND SATURDAY IN
THE 60S...COOLING INTO THE UPPER 50S AND LOWER 60S SUNDAY. OVERNIGHT
TEMPS IN THE 50S FRIDAY NIGHT AHEAD OF THE FRONTAL PASSAGE...AND 40-
45 SATURDAY NIGHT.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 810 PM SUNDAY...
THE DISTURBANCE WHICH HAS BROUGHT ADVERSE AVIATION WEATHER TODAY
WILL BE SHIFTING EAST OF CENTRAL NC BY MIDNIGHT. VFR CONDITIONS HAVE
ALREADY SWEPT INTO INT/GSO AS CHILLY HIGH PRESSURE BUILDS IN FROM
THE NORTHWEST... AND AFTER A FEW MORE HOURS OF MVFR CIGS/VSBYS AT
RDU/RWI/FAY... VFR CONDITIONS ARE EXPECTED TO RETURN BRIEFLY AFTER
03Z. THEN... A BATCH OF MVFR CLOUDS NOW OVER ERN VA IS EXPECTED TO
DROP SOUTHWARD BETWEEN 04Z AND 10Z... AFFECTING RDU/RWI/FAY DURING
THIS TIME FRAME (AS SUPPORTED BY THE HRRR MODEL OUTPUT)... ALTHOUGH
THIS MAY NOT BE A PREVAILING CONDITION. AFTER 10Z... VFR CONDITIONS
ARE EXPECTED ACROSS ALL OF CENTRAL NC... LASTING THROUGH THE END OF
THE TAF VALID PERIOD (00Z TUE). WINDS WILL BE FROM THE NORTH OR NNE
TONIGHT... SHIFTING TO MAINLY NORTHEASTERLY AT ALL SITES MONDAY
MORNING.
LOOKING BEYOND 00Z TUE (MID-EVENING MON): VFR CONDITIONS EXPECTED TO
HOLD THROUGH MON NIGHT... ALTHOUGH CLOUDS WILL BE SPREADING INTO
CENTRAL NC STARTING MON EVENING WITH CIGS THICKENING AND LOWERING
OVERNIGHT. A PASSING UPPER DISTURBANCE AND LOW PRESSURE FORMING OFF
THE COAST WILL BRING MVFR/IFR CIGS FROM AROUND SUNRISE TUE THROUGH
LATE AFTERNOON... WITH A CHANCE OF LIGHT RAIN (MAY BE MIXED WITH
LIGHT SNOW AT GSO/INT/RDU/RWI) THAT COULD BRING MVFR VSBYS. CIGS
WILL LIKELY RISE TO VFR FROM WEST TO EAST IN THE LATE AFTERNOON WITH
A CHANCE OF A RAIN SHOWER. BRISK WINDS FROM THE NW MAY POSE A
CROSSWIND THREAT AT GSO/RDU/RWI/FAY TUE AFTERNOON. VFR CONDITIONS
LIKELY TUE NIGHT THROUGH THURSDAY WITH HIGH PRESSURE BUILDING OVER
THE REGION. SUB-VFR CONDITIONS EXPECTED THU NIGHT INTO FRI WITH
INCREASING SW FLOW AHEAD OF AN APPROACHING FRONTAL SYSTEM. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...BSD
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
315 PM EDT SAT MAR 22 2014
.SYNOPSIS...
A COLD FRONT WILL BRING RAIN TO THE AREA SUNDAY EVENING FOLLOWED
HIGH PRESSURE FROM THE NORTHWEST MONDAY. A RAPIDLY DEEPENING LOW
PRESSURE SYSTEM WILL MOVE NORTHEAST ALONG OUR COAST
TUESDAY...SPREADING COLD RAIN ACROSS THE REGION AND POSSIBLY WET
SNOW ACROSS INLAND LOCATIONS EARLY ON TUESDAY. DRY AND COLD HIGH
PRESSURE WEDNESDAY AND THURSDAY WILL MOVE OFFSHORE LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3:00 PM SATURDAY...THE FIRST SEA-BREEZE RELATED SHOWERS HAVE
DEVELOPED DOWN IN GEORGETOWN COUNTY. TEMPERATURES HAVE RISEN INTO
THE MID AND UPPER 70S EVERYWHERE EXCEPT AT THE COOLER BEACHES...AND
THIS SPRINGTIME HEATING HAS HELPED TO DEVELOP A HEALTHY CU-FIELD IN
ADDITION TO THE SEA-BREEZE FRONT RELATED CONVECTION. EXPECTING
ISOLATED SHOWERS THIS AFTERNOON AND EARLY EVENING...MAINLY
ASSOCIATED WITH THE AFOREMENTIONED SEA BREEZE FRONT.
SLOWLY APPROACHING COLD FRONT WILL DROP SE ACROSS THE FORECAST AREA
OVERNIGHT. WEAK PRESSURE FIELD AND LITTLE IN THE WAY OF THERMAL
CONTRAST THROUGH THE FRONT MAKES PLACEMENT PROBLEMATICAL. BEST
GUESS HAS FRONT LINED UP JUST OFFSHORE BY DAYBREAK ON SUNDAY. WEAK
LIFT ASSOCIATED WITH FRONT AND A STRONG DIURNAL INVERSION SET-UP
MAKES CONVECTION UNLIKELY OVERNIGHT.
A CONSENSUS OF GUIDANCE...BIASED TOWARDS THE BETTER PERFORMING NAM
MOS...HAS ABOVE-AVERAGE OVERNIGHT TEMPERATURES WITH MINIMUMS IN THE
LOWER TO MID 50S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...WE WILL MANAGE ONE LAST DAY OF SEASONABLE TO
SLIGHTLY WARM TEMPS ON SUNDAY...DEPENDING ON HOW QUICKLY THE
BOUNDARY MOVES THROUGH. BUT COME THROUGH IT WILL AND THE ENSUING
COLD ADVECTION WILL BE TREMENDOUS...OUR MIDDAY 850MB TEMPS OF 8C
FALLING TO -4 TO -8C BY 12Z MONDAY (SOUTH TO NORTH). MOISTURE FLUX
AHEAD OF THE FRONT APPEARS TO BE MINIMAL SO RAIN CHANCES WILL
GENERALLY COME FOLLOWING FROPA IN THE UNDERCUTTING BUT ALSO BE
RATHER SHORT-LIVED SINCE THE COLUMN DRIES OUT DRAMATICALLY BY SUNDAY
NIGHT. THE NEW AIRMASS WILL ALLOW TEMPERATURES TO DROP INTO THE 30S
FOR THE FIRST TIME DURING THE RECENTLY STARTED OFFICIAL GROWING
SEASON...BUT A CONTINUED NORTHERLY BREEZE WILL KEEP THINGS MIXED
WELL ENOUGH TO PREVENT FREEZE. FROST MAY NEED TO BE CONSIDERED
THOUGH. MONDAY BRINGS HIGH TEMPS SOME 15 DEGREES BELOW CLIMO EVEN
THOUGH THE CAA MERCIFULLY SHUTS DOWN. AN INTERESTING YET UNCERTAIN
ASPECT OF THE LATE PART OF THE FORECAST PERIOD IS THE SPEED AT WHICH
MOISTURE MANAGES TO RETURN FROM THE SOUTH AS LOW PRESSURE DEVELOPS
OVER FLORIDA...THE VERY SAME LOW THAT MAY END UP BEING AN IMPRESSIVE
BOMB OFF NORTHEAST COAST. THIS IS OF RELATIVELY HEIGHTENED
IMPORTANCE SINCE THERMAL PROFILES MAY SUPPORT SOME WINTRY BUT NON
ACCUMULATING PRECIP...ALTHOUGH THEY LOOK A LITTLE WARMER THAN
PREVIOUS. ADDITIONALLY THE WRF SUPPRESSES EVERYTHING TO OUR SOUTH.
GIVEN THE STRENGTH OF THE WEDGE IN PLACE THIS SOLUTION APPEARS MUCH
MORE APPEALING. FOR THE SAKE OF CONTINUITY HAVE NOT REMOVED THE SNOW
BUT HAVE LOWERED POPS.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 3 PM SATURDAY...MID LEVEL PATTERN WILL REMAIN HIGHLY AMPLIFIED
DURING THE PERIOD. ON TUE RAPIDLY DEEPENING LOW PRESSURE EAST OF
SAVANNAH IS LIFTED NORTHEAST BY MID LEVEL TROUGH. DEEP DRY AIR
SPREADS IN FROM THE WEST TUE BRINGING AN END TO SIGNIFICANT PRECIP
BY MIDDAY. THE 5H TROUGH EVENTUALLY BECOMES NEGATIVELY TILTED BUT
NOT UNTIL THE LOW IS WELL NORTH OF THE AREA. EXITING DEEPENING LOW
AND BUILDING ARCTIC HIGH IN CONJUNCTION WITH THE NEGATIVELY TILTED
TROUGH WILL PRODUCE STRONG COLD ADVECTION TUE NIGHT. 850 TEMPS DROP
CLOSE TO -10C BY WED MORNING...ENSURING LOWS WELL BELOW CLIMO TUE
NIGHT DESPITE STRONG MIXING.
COLD ADVECTION WEAKENS DURING WED AS THE CENTER OF THE HIGH DRIFTS
EAST. LATE MARCH SUNSHINE WILL HELP OFFSET SOME OF THE COLD
ADVECTION BUT HIGHS WILL STILL END UP BELOW CLIMO...BY AS MUCH AS 20
DEGREES. HIGHS WED MAY NOT REACH 50 IN MOST AREAS! ALTHOUGH WED
NIGHT WILL NOT BE A PERFECT RADIATIONAL COOLING NIGHT IT WILL BE
CLOSE. TEMPS BELOW FREEZING ARE LIKELY IN MOST AREAS WITH INLAND
AREAS DROPPING INTO THE 20S. AIR MASS MODIFIES THU/THU NIGHT AS THE
HIGH SHIFTS OFF THE COAST AND WEAK MID LEVEL RIDGE BUILDS. HIGHS
WILL STILL RUN BELOW CLIMO...ABOUT 10 DEGREES BELOW...WITH LOWS
RUNNING CLOSE TO CLIMO.
PRECIP CHANCES INCREASE FOR THE END OF THE PERIOD WITH POTENTIAL
COASTAL TROUGH DEVELOPING THU NIGHT INTO FRI. NEXT MID LEVEL TROUGH
MOVES INTO THE EASTERN CONUS AS THE PERIOD ENDS. SURFACE LOW
ASSOCIATED WITH THE TROUGH WILL MOVE INTO THE NORTHEAST WITH
TRAILING COLD FRONT CROSSING CAROLINAS DURING SAT. WILL MAINTAIN
SILENT POP SAT FOR CONVECTION WITH FROPA. TEMPERATURES NEAR CLIMO
FOR THE END OF THE PERIOD.
&&
.AVIATION /18Z SATURDAY THROUGH WEDNESDAY/...
AS OF 18Z...LOOK FOR INCREASING MID CLOUDS TODAY WITH POSSIBLE
SHOWERS ALONG THE SEA BREEZE BOUNDARY. BEST CHANCE FOR SHOWERS
WILL BE AT THE MYRTLES...MAINLY BASED ON THE HRRR MODEL. SOUTHWEST
WINDS THIS AFTERNOON...MAYBE A BIT GUSTY THIS AFTERNOON WITH MORE
OF A SOUTHERLY COMPONENT ALONG THE COAST. TONIGHT...TIME HEIGHT
SHOWS CONTINUED FLOW OF MOISTURE...WITH CEILINGS LIKELY BOUNCING
FROM MID CLOUD TO OCCASIONAL VFR STRATOCU. IF THERE IS SOME
CLEARING...LOOK FOR SOME MVFR FOG TO SET UP. SUNDAY...VFR IN THE
MORNING WITH INCREASING CLOUDS BY MIDDAY AS THE NEXT SYSTEM
APPROACHES. ANY PRECIPITATION WILL LIKELY COME AFTER THE VALID
TIME PERIOD.
EXTENDED OUTLOOK...MODERATE CONFIDENCE FOR SCATTERED SHOWERS
SUNDAY AFTERNOON THROUGH THE OVERNIGHT HOURS. VFR MONDAY. ANOTHER
CHANCE OF RAIN EXPECTED ON TUESDAY. VFR WEDNESDAY AND THURSDAY.
IFR CONDITIONS ARE POSSIBLE IN THE PRECIPITATION.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3:00 PM SATURDAY...WINDS WILL REMAIN RELATIVELY LIGHT THROUGH
THE PERIOD AS A WEAK COLD FRONT DROPS SOUTHEAST ACROSS THE EASTERN
CAROLINAS AND THEN OVER THE WATERS LATE TONIGHT. STRONGEST WINDS OF
10 TO 15 KTS FROM THE SW WILL BE THIS AFTERNOON. HOWEVER...WINDS
NEAR SHORE THIS AFTERNOON WILL BE MORE IN THE 15 TO 20 KT RANGE DUE
TO A DEVELOPING SEA-BREEZE CIRCULATION. WINDS WILL DECREASE TO
AROUND 10 KTS THIS EVENING THEN AROUND 5 KTS OR LESS AFTER MIDNIGHT
AS THE FRONT SETTLES OVER THE WATERS. SEAS WILL REMAIN IN THE 2 TO 3
FT RANGE THROUGH THE PERIOD.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...COLD FRONT TO MOVE ACROSS THE WATERS SUNDAY
AFTERNOON. THE ENSUING WIND SHIFT AND INCREASE IN SPEEDS WILL BUILD
SEAS AND STEEPEN WAVE FACES. A SMALL CRAFT ADVISORY SEEMS POSSIBLE
BUT THERE IS JUST ENOUGH UNCERTAINTY REGARDING TIMING AND WHICH
ZONES WILL MEET CRITERIA TO PRECLUDE ISSUANCE AT THIS TIME AFTER
COLLAB WITH ADJACENT WFOS. THE NE FLOW WILL REMAIN FOR THE BALANCE
OF THE PERIOD AS A VERY WINTRY HIGH PRESSURE WEDGE SETTLES IN EAST
OF THE APPALACHIANS. THIS WILL KEEP THE GRADIENT MODERATELY STRONG
ACROSS THE WATERS AND MANY ZONES WILL BE CLOSE TO SCEC/ADVISORY
CUTOFFS FOR BOTH WIND AND SEAS.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...HEADLINES WILL LIKELY BE REQUIRED AT SOME
POINT TUE AND TUE NIGHT AS DEPARTING LOW STARTS TO DEEPEN. GRADIENT
OVER THE WATERS BECOMES PINCHED WITH OFFSHORE FLOW APPROACHING 30 KT
TUE NIGHT. GRADIENT SLOWLY WEAKENS WED AS HIGH PRESSURE DRIFTS EAST.
WINDS WILL REMAIN AROUND 20 KT FOR MUCH OF THE DAY BEFORE DROPPING
TO 15 TO 20 KT IN THE AFTERNOON. NORTHWEST FLOW SLOWLY VEERS TO
NORTHEAST WED NIGHT AND SPEEDS DROP TO 10 TO 15 KT AS THE CENTER OF
THE ELONGATED HIGH SHIFTS OVER THE EASTERN NC/VA. ONSHORE FLOW
DEVELOPS THU AS THE HIGH MOVES OFF THE COAST. WEAK GRADIENT WILL
KEEP SPEEDS 10 KT OR LESS. STRONG OFFSHORE FLOW WILL PRODUCE 4 TO 6
FT SEAS TUE AND TUE NIGHT. REDUCTION IN OFFSHORE FLOW WILL EQUATE TO
SEAS DROPPING TO 3 TO 5 FT FOR WED AND 2 TO 4 FT WED NIGHT AND THU.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...REK
SHORT TERM...MBB
LONG TERM...III
AVIATION...REK/DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
124 PM EDT SAT MAR 22 2014
.SYNOPSIS...
MILD TEMPERATURES TODAY WITH A FEW AFTERNOON SHOWERS NEAR THE
COAST CAN BE EXPECTED. A COLD FRONT WILL BRING RAIN TO THE AREA
SUNDAY EVENING FOLLOWED HIGH PRESSURE FROM THE NORTHWEST MONDAY. A
RAPIDLY DEEPENING LOW PRESSURE SYSTEM WILL MOVE NORTHEAST ALONG
OUR COAST TUESDAY...SPREADING COLD RAIN ACROSS THE REGION AND
POSSIBLY WET SNOW ACROSS INLAND LOCATIONS EARLY ON TUESDAY. DRY
AND COLD HIGH PRESSURE WEDNESDAY AND THURSDAY WILL MOVE OFFSHORE
LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1:15 PM SATURDAY...TEMPERATURES HAVE SOARED INTO THE MID AND
EVEN UPPER 70S THIS AFTERNOON...WITH COOLER TEMPERATURES AT THE
BEACHES. SEA BREEZE CU DEVELOPED EARLIER TODAY AND A MORE
EXTENSIVE CU FIELD IS NOW FORMING THROUGHOUT THE CWA. STILL
EXPECTING ISOLATED SEA-BREEZE SHOWERS THIS AFTERNOON. RELEVANT
PORTION OF PREVIOUS DISCUSSION FROM EARLY THIS MORNING FOLLOWS:
WARM ADVECTION TODAY AHEAD OF AN APPROACHING FRONTAL SYSTEM
COUPLED WITH PARTIAL SUNSHINE AND SW FLOW SHOULD BRING MILD
TEMPERATURES INTO THE UPPER 70S WELL INLAND...TO THE LOW 70S
CLOSER TO THE CHILLY MARINE LAYER...AND 60S ALONG IMMEDIATE
BEACHES.
THE LARGE LAND VERSUS SEA TEMP DIFFERENTIAL WILL DRIVE A ROBUST
SEA BREEZE THIS AFTERNOON. SURFACE CONVERGENCE FROM THIS RESULTANT
BOUNDARY...AND INCREASING H9-H7 ABSOLUTE HUMIDITY AFTER 16Z/NOON
COULD SPARK A FEW SHOWERS THIS AFTERNOON ALONG POTENTIALLY A
NARROW CORRIDOR OVER OUR COASTAL INTERIOR. REFRIGERATED SEA-AIR
AND DRY MID-LEVELS SHOULD DETER DEEP CONVECTION AND NO THUNDER IS
PLANNED AT THIS TIME.
GUSTS TO 20 MPH ARE LIKELY AT MOST LOCATIONS THIS AFTERNOON. AREAS
NEAR THE COAST MAY REALIZE MAXIMUM TEMPERATURES EARLY AS THE NIPPY
OCEAN AIR SPREADS INLAND IN THE LATE MORNING THROUGH AFTERNOON.
FROPA EARLY ON SUNDAY WILL BRING WINDS FROM THE NW-W INTO DAYBREAK
AS A COLD FRONT DROPS SSE THROUGH THE AREA. THE FRONT IS WEAK AND
NO APPRECIABLE LIFT APPEARS EVIDENT IN THE LOW-LEVELS...AND WITH
SPARSE MOISTURE...NO MENTIONABLE POPS PLANNED FROM LATE THIS EVE
INTO DAYBREAK SUNDAY.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...EXPECT AN ACTIVE PERIOD DURING THE SHORT TERM
COURTESY OF TWO SYSTEMS. INITIALLY AN ARCTIC FRONT WILL MOVE ACROSS
THE AREA SUNDAY WITH MODELS SHOWING AN INCREASING AREA OF
PRECIPITATION MAXIMIZED ALONG OUR CWA VIA LOW LEVEL CONVERGENCE WITH
THE FRONT COUPLED WITH THE UPPER LEVEL LEFT EXIT REGION OF A
POWERFUL 300MB JET MOVING ACROSS WITH THE SOUTHERN STREAM OF THE
SPLIT FLOW. I HAVE INCREASED POPS TO CATEGORICAL WITH THIS SYSTEM.
WE SHOULD SEE A 12-18 HOUR RESPITE FROM QPF BEFORE THE NEXT SYSTEM
MOVES IN ONCE AGAIN COURTESY OF THE MID LEVEL SOUTHWEST FLOW EARLY
TUESDAY.
THE GFS REMAINS STABLE WITH REGARDS TO ISENTROPIC LIFT DEVELOPING
AROUND 0600 UTC TUESDAY FOR MOST AREAS WITH LOW PRESSURE MOVING
OFFSHORE. THERMAL PROFILES REMAIN INTERESTING AS WELL WITH INLAND
LOCATIONS SUPPORTING SOME SNOW MIXED IN WITH RAIN BEFORE 1200 UTC
TUESDAY.
REGARDING TEMPERATURES...NO SIGNIFICANT CHANGES. I DID INCREASE
HIGHS FOR SUNDAY UPWARD A BIT AS THE FRONT IS SLIGHTLY SLOWER. I
ALSO INCREASED LOWS SLIGHTLY FOR TUESDAY MORNING.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 330 AM SATURDAY...ESSENTIALLY A TEMPERATURE FORECAST BEYOND
TUESDAY WHEN LOW PRESSURE WILL BE MAKING A RAPID DEPARTURE WELL
OFF THE COAST. I CONTINUED TO ADVERTISE LIKELY POPS FOR TUESDAY
AND A FEW HOURS OF A RAIN/SNOW MIX INLAND. WEDNESDAY AND THURSDAY
WILL BE VERY COLD AND DRY AND AT THIS POINT IT APPEARS THURSDAY
MORNING WILL BE THE COLDEST VIA THE MORE FAVORABLE RADIATIONAL
CONDITIONS. A RETURN FLOW BEGINS AT THIS POINT AND IT MAY ALLOW A
COASTAL TROUGH TO DEVELOP WITH SLIGHT CHANCE POPS FOR FRIDAY.
TEMPERATURES RESPOND QUICKLY TO THE LATE MARCH SUN WITH HIGHS IN
THE 60S AND 70S FOR THE END OF THE WORKWEEK.
&&
.AVIATION /18Z SATURDAY THROUGH WEDNESDAY/...
AS OF 18Z...LOOK FOR INCREASING MID CLOUDS TODAY WITH POSSIBLE
SHOWERS ALONG THE SEA BREEZE BOUNDARY. BEST CHANCE FOR SHOWERS
WILL BE AT THE MYRTLES...MAINLY BASED ON THE HRRR MODEL. SOUTHWEST
WINDS THIS AFTERNOON...MAYBE A BIT GUSTY THIS AFTERNOON WITH MORE
OF A SOUTHERLY COMPONENT ALONG THE COAST. TONIGHT...TIME HEIGHT
SHOWS CONTINUED FLOW OF MOISTURE...WITH CEILINGS LIKELY BOUNCING
FROM MID CLOUD TO OCCASIONAL VFR STRATOCU. IF THERE IS SOME
CLEARING...LOOK FOR SOME MVFR FOG TO SET UP. SUNDAY...VFR IN THE
MORNING WITH INCREASING CLOUDS BY MIDDAY AS THE NEXT SYSTEM
APPROACHES. ANY PRECIPITATION WILL LIKELY COME AFTER THE VALID
TIME PERIOD.
EXTENDED OUTLOOK...MODERATE CONFIDENCE FOR SCATTERED SHOWERS
SUNDAY AFTERNOON THROUGH THE OVERNIGHT HOURS. VFR MONDAY. ANOTHER
CHANCE OF RAIN EXPECTED ON TUESDAY. VFR WEDNESDAY AND THURSDAY.
IFR CONDITIONS ARE POSSIBLE IN THE PRECIPITATION.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1:15 PM SATURDAY...LATEST OBS SHOW SW WINDS AT 10 TO 15 KTS
WITH SEAS IN THE 2 TO 3 FT RANGE. NO CHANGES WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:
SOUTHWEST WINDS WILL INCREASE TODAY...AND WILL BECOME GUSTY NEAR
SHORE AS A SEA BREEZE CIRCULATION GEARS UP CONCURRENTLY WITH AN
APPROACHING FRONTAL SYSTEM. GUSTS TO 20 KT FROM THE SSE-SSW BY THE
MIDDLE AFTERNOON CAN BE EXPECTED. SEAS MAINLY 2-3 FT IN ESE SWELL
THIS MORNING WILL SEE INCREASING WIND WAVES AND CHOP THIS
AFTERNOON AND EVENING AS WINDS KICK UP. THUS DOMINANT WAVE PERIODS
OF 12 SECONDS EARLY...WILL SHORTEN TO 5-7 SECONDS THIS
AFTERNOON...PRODUCING STEEPER WAVES. THIS MAY BRING SEAS TO 3-5 FT
LATE TODAY INTO EVENING. MARINERS ARE REMINDED WATER TEMPERATURES
REMAIN FRIGID AND HYPOTHERMIA IS STILL A POTENTIAL AND LURKING
THREAT AWAY FROM LAND.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...INITIALLY WINDS WILL BE LIGHT AND VARIABLE
BEFORE A POTENT ARCTIC FRONT MOVES ACROSS THE WATERS LATE SUNDAY. AT
THIS POINT WINDS GO TO NORTHERLY FROM 20-25 KNOTS. THESE WINDS
PERSIST THROUGH MOST OF THE DAY MONDAY. AS HIGH PRESSURE WEAKENS AND
LOW PRESSURE TAKES SHAPE AND MOVES OFF TO THE SOUTH...WINDS WILL
ACTUALLY WEAKEN AS THE LOW IS SLOW TO DEEPEN AND THERE IS MORE
IMPACT FROM WEAKENING HIGH PRESSURE. SPEEDS DROP TO 15-20 KNOTS.
THERE IS A VEERING TO NORTHEAST/EAST BY TUESDAY MORNING AS WELL.
SEAS WILL FOLLOW THE WINDS WITH HIGHER VALUES LATE SUNDAY THROUGH
BASICALLY THE REMAINDER OF THE PERIOD.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 330 AM SATURDAY...NORTHERLY COMPONENT TO THE WINDS WILL
DOMINATE THE MIDWEEK FORECAST FOR THE COASTAL WATERS. SPEEDS WILL
CERTAINLY ECLIPSE SMALL CRAFT CRITERIA AND MAY BRIEFLY SEE
SUSTAINED WINDS INTO GALE CRITERIA. STRONGEST WINDS APPEAR TO
OCCUR EARLY WEDNESDAY. HIGHEST SEAS WILL BE OFFSHORE WITH THE
TYPICAL RAPID DECREASE TOWARD SHORELINE AREAS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...MJC/REK
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...REK/DL
MARINE...MJC/REK/SHK
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
833 PM CDT SUN MAR 23 2014
.UPDATE...
The latest satellite and radar data indicate showers have moved east
of our area. The latest RUC data indicate precipitation will likely
remain east of our area for the remainder of tonight and tomorrow
morning. Therefore, I removed showers we had for our southern
counties for the remainder of tonight and for tomorrow morning.
Plus, I adjusted sky conditions for the remainder of tonight and
tomorrow morning to reflect satellite trends and model data.
Huber
&&
.PREV DISCUSSION... /ISSUED 633 PM CDT SUN MAR 23 2014/
AVIATION...
/00Z TAFS/
Brady, Junction, and Sonora can expect MVFR conditions overnight as
temperatures cool and and winds diminish. Guidance for San Angelo
and Abilene has CIGS moving back in, but keeps them higher. VFR
conditions will likely prevail. San Angelo looks to be on the edges,
so MVFR conditions cannot be ruled out, especially closer to sunrise.
Reimer
PREV DISCUSSION... /ISSUED 323 PM CDT SUN MAR 23 2014/
SHORT TERM...
(Tonight and Monday)
Lift associated with the RRQ of a 250mb 120+ knot jet streak
interacted with elevated instability and a northward sloping cold
frontal boundary to give the area some thunderstorms earlier
today. Most of this activity has moved east of the area this
afternoon. A surge of colder air moved in this morning, and along
with the rain received around the area, kept temperatures 25 to 30
degrees below normal this afternoon.
For tonight, thinking hasn`t changed much from the previous
forecast. We will see winds become light and variable across the
region as sfc high pressure settles in across Texas. At this time
there is still expected to be low clouds across the area, keeping
ideal radiational cooling conditions from setting up. Therefore,
have kept the temperatures near the previous forecast with lows
getting into the 30s across much of the area, but not down to the
freezing mark. Will keep a small area of low end slight chance
PoPs for the southern tier of the CWA this morning into Monday
morning for any leftover activity that is stubborn to leave the
area.
Monday, a thin, but stubborn layer of low level clouds may hang
around for a few hours after sunrise, but we should see breaks
during the afternoon. The increasingly stronger Spring sun, should
help warm temperatures back into the 60s to near 70 areawide, as
winds turn to the south during the day.
20
LONG TERM...
Next rain chance is late Tuesday night into Wednesday as an upper
trough approaches and moves over from the West. Water Vapor loop
indicates the upper low developing along the coast in N. California.
The upper low is expected to dig south into Baja California before
heading east over Texas. Both the EC and GFS have been consistent in
developing the upper low for the last several days. Model rainfall
amounts have come up to: 1/10 inch in the GFS, 2/10 inch in the EC.
The NAM run is also coming into the picture, with a stronger upper
trough bringing in a large area of 1/2 inch totals. Have increased
pops slightly, but keeping chances in the 30 to 50 percent range.
Drier air Thursday and Friday with breezy west winds. Main impact
will be elevated fire weather potential and, of course, evaporation
of received rainfall Wednesday. Could see an isolated dryline
thunderstorm east/southeast of the Concho Valley Thursday, but did
not include due to limited potential. A dry cold front may move in
late Friday afternoon/evening, bringing slightly cooler but dry
conditions into the weekend.
04
FIRE WEATHER...
Expect quiet conditions through the middle of the week, as
slightly cooler temperatures will keep RH values from bottoming
out too much.
Look for elevated fire weather conditions by Thursday and Friday.
Temperatures warm significantly, resulting in RH values dropping
into the 10 to 15 percent range in some cases. At the same time,
west winds will increase to 10 to 20 mph, with the strongest winds
across areas west of a Sweetwater to Sonora line. 700mb-500mb
winds between 35 and 50 knots each day during the afternoon would
support gusts over 35 mph during the afternoon hours behind the
dryline where mixing will be greatest. The dryline should make it
as far as a Sweetwater to San Angelo to Sonora line Thursday, and
possibly push through most of the area Friday.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 37 70 38 66 48 / 5 0 5 5 10
San Angelo 37 69 44 68 51 / 5 0 5 5 20
Junction 41 65 45 70 51 / 20 5 10 5 20
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
Reimer/Huber
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1244 PM CDT SAT MAR 22 2014
.AVIATION...
CIGS/VIS HAVE BEEN IMPROVING THROUGH THE MORNING WITH CIGS STILL
MVFR IN AUSTIN AND SAN ANTONIO. DRT IS VFR. CIGS SHOULD LIFT TO
VFR AT REMAINING TERMINALS WITHIN THE NEXT HOUR OR TWO. A COLD
FRONT WILL MOVE SLOWLY THROUGH THE REGION TODAY AND TONIGHT. WINDS
WILL TURN TO THE NORTHEAST/EAST AND THEN NORTH. THE FRONT SHOULD
MOVE THE AUSTIN AND SAN ANTONIO AIRPORTS LATE THIS EVENING
BRINGING MVFR CIGS AND WINDS OF 10 TO 15 KTS. WINDS WILL BECOME
GUSTY SUNDAY MORNING AND THERE IS A CHANCE FOR SHRA STARTING MID-
MORNING SUNDAY.
&&
.PREV DISCUSSION... /ISSUED 1143 AM CDT SAT MAR 22 2014/
UPDATE...
FOG CONTINUES TO DISSIPATE LATE THIS MORNING WITH CONTINUED
DAYTIME HEATING AND A COLD FRONT SLOWLY APPROACHING FROM THE
NORTHWEST. WE HAVE UPDATED THE FORECAST TO REMOVE THE MENTION OF
FOG. FOR THIS AFTERNOON...THE HI-RES RUC AND OTHER SHORT RANGE
MODELS AGREE IN SHOWING THE BEST CHANCE FOR PRECIPITATION ACROSS
THE NORTHERN PORTION OF THE AREA...GENERALLY NORTH OF HIGHWAY 71.
THE CURRENT FORECAST IS ON TRACK AND ONLY MINOR CHANGES WERE MADE
TO THE WINDS AND DEW POINTS.
PREV DISCUSSION... /ISSUED 651 AM CDT SAT MAR 22 2014/
AVIATION...
A MIX OF VLIFR TO IFR CIGS/VSBYS WITH PATCHY -DZ WILL LIFT TO MVFR
BY LATE MORNING AND VFR ALL AREAS EARLY THIS AFTERNOON. LOWER
CLOUDS WILL BECOME SCT ACROSS SOME WESTERN AREAS. MVFR/IFR CIGS
WILL REDEVELOP THIS EVENING INTO THE OVERNIGHT. ISOLD SHRA AND
TSRA WILL DEVELOP THIS AFTERNOON INTO TONIGHT AS A COLD FRONT
MOVES ACROSS...AND BECOME SCT SHRA KAUS AREA TONIGHT AND REST OF
AREA ON SUNDAY AS SOME UPPER LEVEL ENERGY MOVES OVERHEAD. S TO SE
WINDS 7 KTS OR LESS AHEAD OF THE FRONT WILL BECOME N TO NE 10 TO
20 KTS WITH GUSTS TO 25 KTS BEHIND THE FRONT.
PREV DISCUSSION... /ISSUED 350 AM CDT SAT MAR 22 2014/
SHORT TERM (TODAY THROUGH SUNDAY)...
MOISTURE POOLING WILL OCCUR OVER SOUTH CENTRAL TX TODAY AS A WEAK
FRONTAL ZONE SETTLES OVER WEST CENTRAL TX. A FLAT ZONAL FLOW ALOFT
AND A FAVORABLE ENTRANCE REGION TO A JET STREAK WILL ALLOW FOR
WEAK LIFT OVER THE AREA...PROMOTING SOME PATCHY DRIZZLE OR
SPRINKLES WITH SOME PATCHY MORNING FOG POSSIBLE OVER MANY AREAS.
LATE IN THE DAY...A FEW THUNDERSTORMS COULD DEVELOP ALONG AND N OF
HWY 90...BUT MUCH OF THIS POTENTIAL ASSUMES CLOUDS ARE ABLE TO
CLEAR OUT TO PROMOTE SOME ADDED HEATING. THE BETTER CHANCE FOR
DEEP CONVECTION LIES OVER CENTRAL TX AND GENERALLY NEAR AND TO THE
EAST AND NORTH OF AUS WHERE THE FRONT WILL HAVE A CHANCE TO
INTERACT WITH HIGHER PRECIPITABLE WATER VALUES. INSTABILITY IS
EXPECTED BE MARGINAL OVER CENTRAL TX...BUT STORMS COULD TAP INTO
DEEPER CAPES AROUND SAN ANTONIO SHOULD THE FRONT SLIP SOUTH INTO
AN AREA WHERE THERE ARE MORE BREAKS IN THE CLOUDS. HIGHS FOR TODAY
ASSUMES SOME PARTIAL CLEARING IN THE AFTERNOON NEAR AND TO THE
WEST OF SAN ANTONIO. THUS THE HWO WILL ADDRESS A FEW STORMS WITH
POSSIBLE HAIL AND GUSTY WINDS.
THE COLD FRONT IS EXPECTED TO PUSH THROUGH THE AREA BY LATE
TONIGHT AND WILL LIKELY INCREASE THE COVERAGE AND AMOUNTS OF RAIN.
POPS REMAIN IN A CHANCE CATEGORY AS THE WEAK FEATURES IN THE ZONAL
FLOW ALOFT DO NOT SEEM TO FAVOR LARGE AREAS OF RAIN TO DEVELOP. A
FEW ELEVATED THUNDERSTORMS WILL BE POSSIBLE OVERNIGHT INTO SUNDAY
AS THE COLD FRONT CONTINUES TO ENHANCE OVERRUNNING. HIGHS FOR
SUNDAY HAVE LEVELED OFF IN THE MODEL TRENDS WITH MUCH BELOW NORMAL
DAYTIME TEMPERATURES.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
THE STORMY ZONAL PATTERN ALOFT CONTINUES...WITH GOOD CHANCES FOR
RAIN INTO MONDAY...AND THERE IS ANOTHER ENHANCED POTENTIAL FOR
STRONG CONVECTION SHOULD THE SKIES OPEN UP MONDAY AFTERNOON. A
MORE SUBSIDENT PATTERN ALOFT IS EXPECTED FOR TUESDAY AFTER ANOTHER
FRONT PUSHES IN MONDAY NIGHT. THUS THE COLD AIR MASS FOR TUESDAY
SHOULD BE DRIER AT FIRST...BUT A MORE SIGNIFICANT WAVE OF ENERGY
ALOFT IS EXPECTED TO SET UP OVERRUNNING BY EARLY WEDNESDAY. THIS
ROUND OF CONVECTION SHOULD DECREASE BY THURSDAY EVENING...AND A
FAIRLY BENIGN TREND IS EXPECTED TO DEVELOP BY NEXT WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 52 57 46 62 44 / 30 40 40 40 10
AUSTIN BERGSTROM INTL AIRPORT 52 57 45 62 42 / 30 40 40 40 20
NEW BRAUNFELS MUNI AIRPORT 55 59 46 62 44 / 20 50 40 50 20
BURNET MUNI AIRPORT 48 54 43 64 42 / 20 30 30 40 10
DEL RIO INTL AIRPORT 61 66 51 68 53 / 20 50 30 20 10
GEORGETOWN MUNI AIRPORT 50 55 43 62 42 / 30 40 30 40 10
HONDO MUNI AIRPORT 58 63 49 64 48 / 20 50 40 50 10
SAN MARCOS MUNI AIRPORT 53 58 46 61 43 / 20 40 40 50 20
LA GRANGE - FAYETTE REGIONAL 55 61 47 61 45 / 20 40 40 50 20
SAN ANTONIO INTL AIRPORT 56 62 49 62 47 / 20 50 40 50 20
STINSON MUNI AIRPORT 57 63 50 62 48 / 20 50 40 50 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...24
PUBLIC SERVICE/DATA COLLECTION...32
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1143 AM CDT SAT MAR 22 2014
.UPDATE...
FOG CONTINUES TO DISSIPATE LATE THIS MORNING WITH CONTINUED
DAYTIME HEATING AND A COLD FRONT SLOWLY APPROACHING FROM THE
NORTHWEST. WE HAVE UPDATED THE FORECAST TO REMOVE THE MENTION OF
FOG. FOR THIS AFTERNOON...THE HI-RES RUC AND OTHER SHORT RANGE
MODELS AGREE IN SHOWING THE BEST CHANCE FOR PRECIPITATION ACROSS
THE NORTHERN PORTION OF THE AREA...GENERALLY NORTH OF HIGHWAY 71.
THE CURRENT FORECAST IS ON TRACK AND ONLY MINOR CHANGES WERE MADE
TO THE WINDS AND DEW POINTS.
&&
.PREV DISCUSSION... /ISSUED 651 AM CDT SAT MAR 22 2014/
AVIATION...
A MIX OF VLIFR TO IFR CIGS/VSBYS WITH PATCHY -DZ WILL LIFT TO MVFR
BY LATE MORNING AND VFR ALL AREAS EARLY THIS AFTERNOON. LOWER
CLOUDS WILL BECOME SCT ACROSS SOME WESTERN AREAS. MVFR/IFR CIGS
WILL REDEVELOP THIS EVENING INTO THE OVERNIGHT. ISOLD SHRA AND
TSRA WILL DEVELOP THIS AFTERNOON INTO TONIGHT AS A COLD FRONT
MOVES ACROSS...AND BECOME SCT SHRA KAUS AREA TONIGHT AND REST OF
AREA ON SUNDAY AS SOME UPPER LEVEL ENERGY MOVES OVERHEAD. S TO SE
WINDS 7 KTS OR LESS AHEAD OF THE FRONT WILL BECOME N TO NE 10 TO
20 KTS WITH GUSTS TO 25 KTS BEHIND THE FRONT.
PREV DISCUSSION... /ISSUED 350 AM CDT SAT MAR 22 2014/
SHORT TERM (TODAY THROUGH SUNDAY)...
MOISTURE POOLING WILL OCCUR OVER SOUTH CENTRAL TX TODAY AS A WEAK
FRONTAL ZONE SETTLES OVER WEST CENTRAL TX. A FLAT ZONAL FLOW ALOFT
AND A FAVORABLE ENTRANCE REGION TO A JET STREAK WILL ALLOW FOR
WEAK LIFT OVER THE AREA...PROMOTING SOME PATCHY DRIZZLE OR
SPRINKLES WITH SOME PATCHY MORNING FOG POSSIBLE OVER MANY AREAS.
LATE IN THE DAY...A FEW THUNDERSTORMS COULD DEVELOP ALONG AND N OF
HWY 90...BUT MUCH OF THIS POTENTIAL ASSUMES CLOUDS ARE ABLE TO
CLEAR OUT TO PROMOTE SOME ADDED HEATING. THE BETTER CHANCE FOR
DEEP CONVECTION LIES OVER CENTRAL TX AND GENERALLY NEAR AND TO THE
EAST AND NORTH OF AUS WHERE THE FRONT WILL HAVE A CHANCE TO
INTERACT WITH HIGHER PRECIPITABLE WATER VALUES. INSTABILITY IS
EXPECTED BE MARGINAL OVER CENTRAL TX...BUT STORMS COULD TAP INTO
DEEPER CAPES AROUND SAN ANTONIO SHOULD THE FRONT SLIP SOUTH INTO
AN AREA WHERE THERE ARE MORE BREAKS IN THE CLOUDS. HIGHS FOR TODAY
ASSUMES SOME PARTIAL CLEARING IN THE AFTERNOON NEAR AND TO THE
WEST OF SAN ANTONIO. THUS THE HWO WILL ADDRESS A FEW STORMS WITH
POSSIBLE HAIL AND GUSTY WINDS.
THE COLD FRONT IS EXPECTED TO PUSH THROUGH THE AREA BY LATE
TONIGHT AND WILL LIKELY INCREASE THE COVERAGE AND AMOUNTS OF RAIN.
POPS REMAIN IN A CHANCE CATEGORY AS THE WEAK FEATURES IN THE ZONAL
FLOW ALOFT DO NOT SEEM TO FAVOR LARGE AREAS OF RAIN TO DEVELOP. A
FEW ELEVATED THUNDERSTORMS WILL BE POSSIBLE OVERNIGHT INTO SUNDAY
AS THE COLD FRONT CONTINUES TO ENHANCE OVERRUNNING. HIGHS FOR
SUNDAY HAVE LEVELED OFF IN THE MODEL TRENDS WITH MUCH BELOW NORMAL
DAYTIME TEMPERATURES.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
THE STORMY ZONAL PATTERN ALOFT CONTINUES...WITH GOOD CHANCES FOR
RAIN INTO MONDAY...AND THERE IS ANOTHER ENHANCED POTENTIAL FOR
STRONG CONVECTION SHOULD THE SKIES OPEN UP MONDAY AFTERNOON. A
MORE SUBSIDENT PATTERN ALOFT IS EXPECTED FOR TUESDAY AFTER ANOTHER
FRONT PUSHES IN MONDAY NIGHT. THUS THE COLD AIR MASS FOR TUESDAY
SHOULD BE DRIER AT FIRST...BUT A MORE SIGNIFICANT WAVE OF ENERGY
ALOFT IS EXPECTED TO SET UP OVERRUNNING BY EARLY WEDNESDAY. THIS
ROUND OF CONVECTION SHOULD DECREASE BY THURSDAY EVENING...AND A
FAIRLY BENIGN TREND IS EXPECTED TO DEVELOP BY NEXT WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 78 52 57 46 62 / 20 30 40 40 40
AUSTIN BERGSTROM INTL AIRPORT 77 52 57 45 62 / 20 30 40 40 40
NEW BRAUNFELS MUNI AIRPORT 79 55 59 46 62 / 20 20 50 40 50
BURNET MUNI AIRPORT 75 48 54 43 64 / 30 20 30 30 40
DEL RIO INTL AIRPORT 88 61 66 51 68 / 20 20 50 30 20
GEORGETOWN MUNI AIRPORT 75 50 55 43 62 / 30 30 40 30 40
HONDO MUNI AIRPORT 86 58 63 49 64 / 20 20 50 40 50
SAN MARCOS MUNI AIRPORT 77 53 58 46 61 / 20 20 40 40 50
LA GRANGE - FAYETTE REGIONAL 80 55 61 47 61 / 20 20 40 40 50
SAN ANTONIO INTL AIRPORT 82 56 62 49 62 / 20 20 50 40 50
STINSON MUNI AIRPORT 83 57 63 50 62 / 20 20 50 40 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...24
PUBLIC SERVICE/DATA COLLECTION...32
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
247 PM MDT SAT MAR 22 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 300 PM MDT SAT MAR 22 2014
LIGHT SNOW CONTINUES EARLY THIS AFTERNOON MAINLY FOR EASTERN
PORTIONS OF THE FORECAST AREA AS THE SHORTWAVE TROUGH MOVES ACROSS
WYOMING. EXPECTING SNOW TO END FROM NORTHWEST TO SOUTHEAST LATE THIS
AFTERNOON AS THE TROUGH AXIS MOVES OVER AND THEN OUT OF THE FORECAST
AREA. A 1040 MB SFC HIGH WILL SLIDE SOUTH ACROSS THE CENTRAL PLAINS
THIS AFTERNOON AND EVENING...WITH SFC WINDS ACROSS THE FORECAST AREA
SWITCHING FROM THE EAST-NORTHEAST TO THE SOUTH. THIS PERSISTENT
UPSLOPE COMPONENT ALONG WITH INCREASING NEAR SFC MOISTURE FROM THE
RECENT SNOW WILL KEEP A VERY MOIST AIRMASS IN PLACE TONIGHT ACROSS
THE EASTERN PLAINS. WITH TEMPERATURES EXPECTED TO DROP INTO THE
TEENS WITHIN THE COLD POST FRONTAL AIRMASS CURRENTLY IN PLACE...LOOKING
FOR AT LEAST PATCHY AREAS OF FOG TO DEVELOP IN MANY AREAS ALONG AND
EAST OF THE LARAMIE RANGE. SHOULD INITIALLY DEVELOP IN TYPICAL
UPSLOPE FOG LOCATIONS VCTY SOUTH LARAMIE RANGE THIS EVENING...THEN
WILL SPREAD NORTH AND EAST THROUGH EARLY TOMORROW MORNING. FORECAST
SOUNDINGS ACROSS THIS AREA SUGGEST THE FOG SHOULD NOT BE VERY
DENSE...BUT THINK VISIBILITIES WILL DROP TO AT LEAST A MILE. IN THE
SOUTH LARAMIE RANGE AND FOOTHILLS...DO EXPECT VISIBILITIES TO DROP
BELOW A MILE FOR A PERIOD EARLY TONIGHT WITHIN THE HIGHER
ELEVATIONS.
THE NEXT SHORTWAVE TROUGH WILL APPROACH FROM THE NORTHWEST TOMORROW
MORNING...WITH A LEE SIDE SFC PRESSURE TROUGH DEVELOPING AHEAD OF
THIS WAVE. AS THE SFC TROUGH DEVELOPS...WINDS WILL SHIFT BACK TO THE
WEST-SOUTHWEST TONIGHT AND WILL PUSH THE COLD AIRMASS AND FOG/LOW
CLOUDS TO THE EAST THROUGH THE MORNING. THE SFC PRESSURE GRADIENT
DOES NOT LOOK TO BECOME VERY STRONG...BUT SUSTAINED WINDS OF 25 TO
35 MPH WITH GUSTS OF AT LEAST 50 MPH ARE LOOKING A LIKELY BET IN THE
WIND PRONE AREAS ALONG AND WEST OF THE LARAMIE RANGE THROUGH EARLY
SUNDAY AFTERNOON. THE SFC TROUGH WILL SLOWLY SHIFT SOUTHEAST ACROSS
THE CWA THROUGH THE DAY AS THE UPPER WAVE APPROACHES FROM THE
NORTHWEST. LOOKING AT WARMER CONDITIONS AS A RESULT OF WAA AHEAD OF
THE WAVE AND DOWNSLOPE WINDS...WITH MINIMAL MOISTURE AVAILABLE FOR
ANY PRECIP. THE COLD FRONT ASSOCIATED WITH THE UPPER WAVE WILL
SLIDE SOUTH ACROSS THE EASTERN PLAINS TOMORROW LATE
AFTERNOON/EVENING. BREEZY NORTH TO NORTHWEST WINDS WILL OCCUR BEHIND
THE FRONT WITH LIGHT RAIN SPREADING FROM NORTH TO SOUTH CHANGING TO
SNOW QUICKLY BEHIND THE FRONT. THE SYSTEM LOOKS TO BE A QUICK HITTER
WITH LESS AVAILABLE MOISTURE THAN THE CURRENT SYSTEM...SO SNOWFALL
ACCUMULATIONS WILL BE LESS OVERALL ON THE ORDER OF 1 TO 2 INCHES BY
MONDAY MORNING. DRIER AND COOLER CONDITIONS WILL RETURN FOR MONDAY
AS THE SFC HIGH BUILDS IN FROM THE NORTHWEST BEHIND THE SYSTEM. WEST
TO NORTHWEST WIND WILL REMAIN BREEZY THROUGH THE DAY AND WILL GUST
ON AVERAGE 25 TO 35 MPH. HIGHER SPEEDS WILL OCCUR IN THE WIND PRONE
AREAS OUT WEST.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 300 PM MDT SAT MAR 22 2014
FRONTAL BOUNDARY STILL LAYING UP ALONG THE EAST LARAMIE RANGE
MONDAY NIGHT AND LOOKS TO REMAIN THERE THROUGH TUESDAY. GOING TO
HAVE A PRETTY COLD NIGHT MONDAY NIGHT WITH LOWS IN THE TEENS.
WINDS BECOME MORE WESTERLY TUESDAY AFTERNOON WITH 700MB
TEMPERATURES CLIMBING TO 0C SO WE SHOULD SEE AFTERNOON HIGHS
CLIMBING BACK INTO THE 50S ACROSS THE PANHANDLE.
ANOTHER SHORTWAVE LOOKS TO MOVE INTO THE AREA WEDNESDAY NIGHT INTO
THURSDAY. SOME DIFFERENCES IN THE MODELS WITH THE ECMWF MOVING THE
ENERGY INTO NORTHERN COLORADO AND THE GFS BRINGING THE VORT MAX
THROUGH SOUTHERN WYOMING. THIS SLIGHT DIFFERENCE WILL HAVE
SIGNIFICANT IMPACTS ON POPS. IF THE ECMWF SOLUTIONS COMES
TRUE...WIDESPREAD SNOW WOULD RESULT. DID A BLEND ON THE TWO MODELS
WITH HIGH CHANCE POPS.
FRONT TO REMAIN ALONG THE EAST SLOPES OF THE LARAMIE RANGE THROUGH
FRIDAY BEFORE SHIFTING OFF TO THE EAST. WARMER AND DRIER WEATHER
THEN RETURNS TO THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY MORNING)
ISSUED AT 1135 AM MDT SAT MAR 22 2014
LOW FLIGHT CONDITIONS WILL CONTINUE THIS AFTERNOON AS WIDESPREAD
SNOW OVERLAYS THE AREA. THIS SNOW IS MOVING SLOWLY SOUTHEAST...BUT
WILL TAKE SOME TIME TO MOVE OUT OF THE AREA. LATEST HRRR GUIDANCE
SUGGESTS A SMALL BREAK FOR AIRPORTS ACROSS THE NORTHERN PANHANDLE
THIS AFTERNOON...BUT FOR THE SOUTH AND HERE AT KCYS...DO BELIEVE
WE WILL HOLD ONTO LOW CEILINGS THROUGH THIS EVENING. WINDS SHIFT
WEST AND BECOME DOWNSLOPING THIS EVENING LATE...SO VFR CONDITIONS
SHOULD RETURN THEN.
&&
.FIRE WEATHER...
ISSUED AT 300 PM MDT SAT MAR 22 2014
COOL CONDITIONS ALONG WITH CHANCES FOR RAIN AND SNOW ARE EXPECTED
THROUGH EARLY NEXT WEEK...AND WILL KEEP ANY FIRE WEATHER THREATS AT
BAY. WARMER AND BREEZY TUESDAY AND WEDNESDAY THEN MORE COOL WEATHER
LATE INTO NEXT WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...RJM
LONG TERM...CLAYCOMB
AVIATION...CLAYCOMB
FIRE WEATHER...RJM
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1139 AM MDT SAT MAR 22 2014
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 256 AM MDT SAT MAR 22 2014
TODAY...POSITIVELY TILTED SHORTWAVE TROUGH ALOFT MOVES FROM WESTERN
WYOMING THIS MORNING TO NORTHERN COLORADO THIS EVENING WITH
WIDESPREAD UPWARD VERTICAL MOTION AND WARM AIR ADVECTION OVER OUR
DEEPLY MOIST LOW AND MID LEVELS...PRODUCING WIDESPREAD LIGHT TO
MODERATE SNOW...MOSTLY EAST OF INTERSTATE 25. SNOWFALL AMOUNTS BASED
ON THE QPF STILL LOOK TO BE MAINLY IN THE 1 TO 3 INCH RANGE WITH A
FEW AMOUNTS IN EXCESS OF 3 INCHES...THOUGH STILL TOO LIMITED TO
WARRANT A WINTER WEATHER ADVISORY.
TONIGHT...DECREASING CLOUDS AND SNOW AS THE SHORTWAVE TROUGH MOVES
AWAY AND LIFT DECREASES.
SUNDAY...NEXT LOWER AMPLITUDE PROGRESSIVE SHORTWAVE TROUGH ALOFT
MOVES TO NORTHERN WYOMING...PRODUCING DECENT SURFACE LEE TROUGHING
AND A WARMING TREND ACROSS OUR COUNTIES.
SUNDAY NIGHT...NEXT COLD FRONT AND BAROCLINIC BAND MOVE ACROSS OUR
COUNTIES AS THE LOW AMPLITUDE SHORTWAVE TROUGH ALOFT MOVES ACROSS
THE CENTRAL PLAINS STATES...PRODUCING SCATTERED SNOW SHOWERS OVER
MOST OF OUR COUNTIES BUT WITH MINIMAL ACCUMULATIONS DUE TO THE LACK
OF LOW LEVEL MOISTURE.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 256 AM MDT SAT MAR 22 2014
ACTIVE WEATHER PATTERN WILL CONTINUE THROUGH THE EXTENDED PERIOD.
ANOTHER QUICK MOVING SHORTWAVE WILL SHIFT EAST INTO THE PLAINS
MONDAY MORNING WITH A RIDGE BUILDING MONDAY AFTERNOON INTO
TUESDAY. WARMER AIR WILL MOVE INTO THE AREA MONDAY BUT THERE COULD
BE ONE MORE BACKDOOR PUSH OF COOL AIR MONDAY NIGHT WITH SURFACE
HIGH PRESSURE OVER THE PLAINS. BY TUESDAY MUCH WARMER DOWNSLOPE
FLOW WILL SET IN WITH HIGHS IN THE 50S OVER MUCH OF THE AREA.
THE WARMEST DAY OF THE WEEK WILL LIKELY BE WEDNESDAY AS THE AXIS
OF THE UPPER LEVEL RIDGE PUSHES INTO THE PLAINS. SHOULD SEE HIGHS
IN THE 50S AND 60S...COULD BE EVEN WARMER BUT WILL LIKELY SEE A
LOT OF HIGH CLOUDS STREAMING INTO THE AREA AHEAD OF THE NEXT UPPER
LEVEL TROUGH. COOLER GOING INTO THE LAST FEW DAYS OF THE WEEK AS
PACIFIC ENERGY PUSHES INTO THE ROCKIES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY MORNING)
ISSUED AT 1135 AM MDT SAT MAR 22 2014
LOW FLIGHT CONDITIONS WILL CONTINUE THIS AFTERNOON AS WIDESPREAD
SNOW OVERLAYS THE AREA. THIS SNOW IS MOVING SLOWLY SOUTHEAST...BUT
WILL TAKE SOME TIME TO MOVE OUT OF THE AREA. LATEST HRRR GUIDANCE
SUGGESTS A SMALL BREAK FOR AIRPORTS ACROSS THE NORTHERN PANHANDLE
THIS AFTERNOON...BUT FOR THE SOUTH AND HERE AT KCYS...DO BELIEVE
WE WILL HOLD ONTO LOW CEILINGS THROUGH THIS EVENING. WINDS SHIFT
WEST AND BECOME DOWNSLOPING THIS EVENING LATE...SO VFR CONDITIONS
SHOULD RETURN THEN.
&&
.FIRE WEATHER...
ISSUED AT 256 AM MDT SAT MAR 22 2014
COOL CONDITIONS THROUGH EARLY NEXT WEEK WILL KEEP ANY FIRE WEATHER
THREATS AT BAY. SNOW WILL BE FOUND OVER MOST OF THE FORECAST AREA
TODAY. SNOW ACCUMULATIONS WILL MAINLY BE IN THE 1 TO 3 INCH RANGE
WITH MOST OF THE SNOW OCCURRING THIS MORNING INTO EARLY THIS
AFTERNOON. ANOTHER SHOT OF LIGHT SNOW SUNDAY NIGHT ALONG AND EAST
OF THE LARAMIE RANGE BUT ACCUMULATIONS WILL GENERALLY BE A DUSTING
TO AROUND 1 INCH. WARMER AND BREEZY TUESDAY AND WEDNESDAY THEN
MORE COOL WEATHER LATE INTO NEXT WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...RUBIN
LONG TERM...SML
AVIATION...CLAYCOMB
FIRE WEATHER...SML
AREA FORECAST DISCUSSION
NWS MIAMI FL
200 AM EDT MON MAR 24 2014
.AVIATION...
A PREFRONTAL TROUGH IS FORECAST TO MOVE THROUGH SOUTH FLORIDA
OVERNIGHT. A 2-4HR PERIOD OF MVFR/IFR CONDITIONS ARE POSSIBLE AT
THE EAST COAST TAF SITES IN THE 08-12Z TIME FRAME AS THE TROUGH
MOVES THROUGH. WINDS WILL ALSO SHIFT FROM THE WEST TO THE
NORTHWEST BY THE MORNING. WINDS WILL CONTINUE TO VEER THROUGH THE
MORNING TO THE NORTHEAST AND THEN EAST AND SOUTHEAST BY THE MID
AFTERNOON AS A SEA BREEZE DEVELOPS. THE MAIN FRONT IS FORECAST TO
STALL NEAR LAKE OKEECHOBEE BY LATE THIS AFTERNOON INTO THE EARLY
EVENING AND THEN LIFT NORTHWARD AS AN AREA OF LOW PRESSURE
DEVELOPS ALONG THE BOUNDARY. MODELS HAVE BACKED OFF ON RAIN
CHANCES FOR THE MORNING HOURS TODAY...OUTSIDE OF PBI. A FEW
SHOWERS ARE POSSIBLE IN THE MORNING...MAINLY FOR PBI AND APF...BUT
THE MAIN THREAT FOR SHOWERS WILL BE LATE THIS AFTERNOON AND THE
OVERNIGHT HOURS.
AT KAPF...SCT/BKN 07KFT CLOUDS WILL CONTINUE UNTIL THE TROUGH
MOVES THROUGH LATE OVERNIGHT. WINDS WILL SHIFT TO THE NORTHEAST IN
THE MORNING...AND THEN BACK TO THE WEST IN THE AFTERNOON AS A SEA
BREEZE DEVELOPS. SHOWERS ARE POSSIBLE IN THE AFTERNOON...WITH
SHOWERS PREVAILING OVERNIGHT MONDAY.
&&
.PREV DISCUSSION... /ISSUED 758 PM EDT SUN MAR 23 2014/
AVIATION...
VFR CONDITIONS ARE EXPECTED THROUGH THE OVERNIGHT HOURS AS SKIES
ARE CLEARING THIS EVENING. THERE STILL MAY BE SOME PERSISTENT
CLOUDS THROUGH THE NIGHT, BUT SHOULD NOT GO BELOW MVFR. BY
TOMORROW, A COLD FRONT WILL DRIFT SOUTHWARDS AND STALL ACROSS
SOUTH FLORIDA. THIS WILL BRING A CHANCE FOR MAINLY SHOWERS
TOMORROW. BUT, THERE IS A CHANCE THAT SOME THUNDERSTORMS MAY BE
ABLE TO FORM, ESPECIALLY IN THE AFTERNOON. THESE SHOWERS AND
THUNDERSTORMS, IF ABLE TO PASS OVER A TAF SITE, MAY TEMPORARILY
REDUCE CONDITIONS TO IFR.
WINDS ARE ANOTHER ISSUE. THEY SHOULD BECOME LIGHT TONIGHT, OUT OF
THE NORTHWEST, WITH SOME LOCATIONS BECOMING VARIABLE. AROUND
DAYBREAK, THEY WILL PICK UP OUT OF THE NORTHWEST. THEY WILL TURN
TO THE NORTHEAST BY MID DAY, THEN POSSIBLY SSE BY EARLY TO MID
AFTERNOON.
PREV DISCUSSION... /ISSUED 722 PM EDT SUN MAR 23 2014/
UPDATE...
CLOUDS WILL CONTINUE TO INCREASE IN COVERAGE ACROSS SOUTH FLORIDA
FROM NORTH TO SOUTH THROUGH THE NIGHT AS A COLD FRONT SLOWLY
INCHES CLOSER TO THE AREA. A FEW SHOWERS ASSOCIATED WITH A WEAK
SURFACE TROUGH WELL OUT AHEAD OF THE FRONT ARE EXPECTED TO LINGER
ACROSS MAINLY THE ATLANTIC WATERS THROUGH THE LATE EVENING HOURS
BEFORE DISSIPATING. UPDATED FORECAST ACCORDINGLY. KEPT PATCHY FOG
OUT OF THE FORECAST FOR THE OVERNIGHT HOURS WITH THE INCREASING
CLOUD COVER EXPECTED. REMAINDER OF THE FORECAST IS ON TRACK.
PREV DISCUSSION... /ISSUED 216 PM EDT SUN MAR 23 2014/
UPDATE...
MADE A QUICK CHANGE FOR THE AFTERNOON AND ADDED SLIGHT CHANCE OF A
SHOWER ALONG THE SOUTHEAST COAST. TEMPERATURES HAVE SOARED CLOSE
TO 90 AND A SEA BREEZE HAS DEVELOPED SLOWLY PUSHING INLAND. THE
LATEST HRRR IS NOW SHOWING A COUPLE OF LATE AFTERNOON SHOWERS
DEVELOPING ALONG THE BREEZE.
PREV DISCUSSION... /ISSUED 141 PM EDT SUN MAR 23 2014/
SHORT TERM (TONIGHT-TUESDAY NIGHT)...
SOUTH FLORIDA REMAINS UNDER THE INFLUENCE OF ZONAL FLOW ALOFT WITH
WEAK HIGH PRESSURE AT THE SURFACE. THIS TREND WILL CONTINUE
THROUGH EARLY MONDAY. A LARGE SCALE MID LEVEL TROUGH WILL DEEPEN
ACROSS EASTERN CANADA TONIGHT AND THEN INTO THE NEW ENGLAND STATES
MONDAY NIGHT AND TUESDAY. A COLD FRONT ASSOCIATED WITH THE
CANADIAN TROUGH WILL MOVE INTO NORTH FLORIDA THIS EVENING AND
SLOWLY MOVE DOWN THE PENINSULA ON MONDAY ARRIVING IN SOUTH FLORIDA
DURING THE AFTERNOON WHERE IT WILL THEN STALL. A SOUTHERN STREAM
PERTURBATION EMBEDDED IN THE ZONAL FLOW ACROSS THE NORTHERN GULF
OF MEXICO WILL AID IN MOVING THE FRONT BACK NORTH BY MONDAY
EVENING AND A SURFACE WAVE WILL DEVELOP ALONG THE BOUNDARY IN
RESPONSE TO SOUTHERN STREAM TROUGH. ALL OF THIS WILL COMBINE TO
PROVIDE DECENT VERTICAL ASCENT ACROSS THE FLORIDA PENINSULA MONDAY
NIGHT THROUGH MOST OF THE DAY ON TUESDAY FOR A CLOUDY WEATHER
PATTERN FOR SOUTH FLORIDA WITH PERIODS OF RAIN. FORECAST SOUNDINGS
SHOW PWAT INCREASING IN THE RANGE OF 1.6-1.8 INCHES IN THE TIME
PERIOD MONDAY NIGHT THROUGH TUESDAY. THIS PLACES THE PWAT AT WELL
ABOVE NORMAL AND ONLY EXCESSIVE IF THE HIGHER RANGE CAN BE
ACHIEVED. SO, RAINFALL AMOUNTS ARE NOT EXPECTED TO BE EXCESSIVE
BUT OVERALL COVERAGE WILL BE ON THE ORDER OF ONE TO TWO INCHES
WITH ISOLATED HIGHER AMOUNTS ALWAYS POSSIBLE, ESPECIALLY IF
TRAINING OF ECHOES BEGINS TO ENFOLD. THE NEW ENGLAND TROUGH WILL
CONTINUE TO DEEPEN TO THE SOUTHEAST ON MONDAY NIGHT AND TUESDAY
WHICH IN TURN WILL CAUSE THE SURFACE WAVE TO LIFT TO THE NORTHEAST
ON TUESDAY AND THE COLD FRONT WILL FINALLY PUSH THROUGH SOUTH
FLORIDA BY TUESDAY AFTERNOON AND OFF THE SOUTHEAST COAST TUESDAY
EVENING. THE SKY WILL THEN CLEAR TUESDAY NIGHT WITH COOLER
TEMPERATURES AS COOLER AND DRIER AIR FILTER DOWN THE PENINSULA
BEHIND THE FRONT.
LONG TERM (WEDNESDAY-SUNDAY)...
THE FIRST PART OF THE EXTENDED WILL BEGIN DRY AND PLEASANT WITH
TEMPERATURES ON WEDNESDAY AFTERNOON REMAINING IN THE 70S. A ZONAL
FLOW PATTERN WILL RETURN BY THURSDAY CONTINUING INTO NEXT WEEKEND.
HOWEVER, ANOTHER EMBEDDED MID LEVEL TROUGH WILL MOVE ACROSS THE
GULF OF MEXICO AND OVER SOUTH FLORIDA THURSDAY AND FRIDAY FOR
ANOTHER INCREASE IN SHOWER ACTIVITY POSSIBLY LINGERING INTO
SATURDAY BEFORE DRYING OUT AGAIN ON SUNDAY.
MARINE...
WIND AND SEAS WILL REMAIN RATHER TRANQUIL THROUGH MONDAY AS HIGH
PRESSURE DOMINATES. A COLD FRONT WILL MOVE INTO THE SOUTH FLORIDA
WATERS LATE MONDAY AND THEN RETREAT BACK TO THE NORTH MONDAY
NIGHT. A SECONDARY COLD FRONT WILL MOVE THROUGH THE LOCAL WATERS
LATE TUESDAY WITH HIGH PRESSURE BUILDING BEHIND THE FRONT. LOCAL
WIND WILL BE LIGHT AND MAINLY WESTERLY TONIGHT RAPIDLY BECOMING
LIGHT NORTHEAST ON MONDAY AS THE FRONT APPROACHES. EXTENSIVE AREAS
OF RAIN WILL DEVELOP LATE MONDAY THROUGH TUESDAY AND THEN CLEAR
OUT TUESDAY EVENING AS THE FRONT PUSHES OFF THE SOUTHEAST COAST.
WIND WILL SHIFT TO THE NORTHWEST BEHIND THE FRONT TUESDAY NIGHT
AND WEDNESDAY POSSIBLY INCREASING TO AROUND 20 KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 80 69 80 59 / 40 70 50 20
FORT LAUDERDALE 81 71 80 61 / 40 60 60 20
MIAMI 83 71 80 61 / 40 50 60 20
NAPLES 79 69 76 57 / 40 70 70 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...84/AK
LONG TERM....54/BNB
AVIATION...84/AK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
358 AM CDT MON MAR 24 2014
.SYNOPSIS...
ISSUED AT 316 AM CDT MON MAR 24 2014
WEAK TROUGH WILL MOVE ACROSS THE STATE TODAY FOLLOWED ONE LAST
SURGE OF POLAR AIR ON TUE AS HIGH PRESSURE DROPS SOUTHEAST ACROSS
THE REGION. PATTERN WILL UNDER GO A CHANCE ONCE THE EAST COAST LOW
PUSHES OUT OF THE WAY. UPPER RIDGE WILL STRENGTHEN WITH MORE
INFLUENCE FROM THE SOUTHERN STREAM. LOW PRESSURE WILL MOVE OUT OF
THE ROCKIES THROUGH IA THU NIGHT WITH ONLY A WEAK PUSH OF COOLER
AIR BEHIND IT WITH THE NEXT HIGH BEING MORE PACIFIC IN NATURE.
&&
.SHORT TERM /TODAY/...
ISSUED AT 316 AM CDT MON MAR 24 2014
DIFFICULT FORECAST FOR WHAT I BELIEVE WILL BE A LIGHT SNOW EVENT.
RADAR HAS BEEN SHOWING A BAND OF LIGHT SNOW FROM WEST OF SAC CITY
THROUGH THE DES MOINES METRO AREA THEN SOUTHEAST TO ABOUT CORYDON.
SOUNDINGS SHOW A DRY LAYER NEAR THE SURFACE AND A QUICK CHECK OF
SNOWFALL AFTER THREE AND A HALF HOURS OF SNOWFALL REVEALS DRY AIR
NEAR THE SURFACE IS INDEED IN PLACE. THERE IS BARELY A TENTH OF AN
INCH OF SNOW ON THE GROUND AT THE OFFICE. THERE ARE A LOT OF
PROBLEMS WITH THIS SYSTEM WHICH ARE GIVING MODELS FITS. FIRST IS
THE DISTINCT DRY LAYER NEAR THE SURFACE. THIS WILL IMPROVE SOME
THIS MORNING AS MOISTURE SATURATES A DEEPER LAYER. THE PROBLEM...IF
YOU CAN BELIEVE THE MODELS AT ALL IS THAT IT WILL COME IN SEVERAL
BOUTS. ANY FORCING THAT COMES ACROSS BEFORE WE CAN SATURATE WILL
YIELD VERY LITTLE SNOWFALL. HOWEVER IN THE PERIOD FROM MID MORNING
THROUGH EARLY AFTERNOON MANY LOCATIONS WILL LIKELY PICK UP AROUND AN
INCH PERHAPS LOCALLY TWO. ALL THE HI-RES MODELS EXPAND THE PRECIP
OVER OUR FORECAST AREA BY 18Z SO I FEEL CONFIDENT IS EXPANDING POPS
ACROSS THE AREA BUT THE NAM12 HAS HIGHER SNOWFALL IN THE NORTH
CENTRAL TO NORTHEAST WHILE THE HRRR HAS A CORRIDOR OF HIGHER AMOUNTS
ALONG AND EAST OF THE I-35 CORRIDOR. OTHER HI-RES MODELS VARY FROM
ALMOST NOTHING AT ALL BEING A LITTLE SLOWER IN MOVING THE EXPANSION
EAST.
I TRIED TO TIE HIGHER AMOUNTS TO LOCATIONS WHERE IT APPEARED FORCING
WOULD BE STRONGER FOR AT LEAST SEVERAL HOURS AND WHERE MOISTURE WAS
DEEPER.
AS FOR TEMPS...WENT BELOW GUIDANCE BY UP TO A CATEGORY. I CANNOT SEE
US CLIMBING MUCH TODAY GIVEN THE CLOUD COVER AND PRECIP. A CHECK OF
ROAD SURFACE TEMPS INDICATES ROAD SURFACES HAVE COOLED TO WELL BELOW
FREEZING SO TO BE PROACTIVE WE WILL HAVE A SPECIAL WEATHER STATEMENT
OUT TO INDICATE THE POTENTIAL FOR SLICK SPOTS.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 316 AM CDT MON MAR 24 2014
AS THE TROUGH PULLS AWAY...SNOW WILL END FROM WEST TO EAST
TONIGHT. A SECONDARY S/WV WILL BRING SOME LIGHT SNOW LATER
TONIGHT AND SLOW THE EASTWARD PROGRESS OF THE ENDING...BUT ALL
SHOULD BE OUT OF THE CWA BEFORE MORNING.
COLD HIGH PRESSURE WILL SETTLE IN BEHIND THE TROUGH AND KEEP TEMPS
WELL BELOW NORMAL FOR TUE INTO TUE NIGHT. CHANGES ARE IN THE
WORKS AS THE PATTERN SHIFTS NORTH. HEIGHTS BUILD INTO THE CENTRAL
U.S. WITH THE NORTHERN STREAM BEING PUSHED TO THE NORTH OF IA. THE
SOUTHERN STREAM WILL HAVE MORE INFLUENCE WITH TEMPS REBOUNDING
QUICKLY ON WED AND THU. KEPT THE THUNDER IN THE FORECAST AND HAVE
MOVED IT INTO THE SWRN ZONES LATE WED NIGHT WITH STRONG WAA AND
ARM FRONT JUST SOUTH OF THE CWA. WIDESPREAD RAIN AND ISOLD THUNDER
ON TAP FOR A GOOD PART OF THE CWA THU WITH ELEVATED CAPE OVER THE
SOUTH REACHING ABOUT 500 J/KG. LOW WILL PULL OUT THU NIGHT WITH A
MIX OF -RASN. ECMWF CONTINUES TO BE MORE INTENSE WITH THIS
SYSTEM...THOUGH UNCERTAINTY REMAINS...IT WILL NEEDED TO BE
MONITORED FOR THE POTENTIAL OF A NARROW BAND OF HEAVIER SNOW
BEHIND THE LOW.
FRIDAY WILL BE COOLER WITH SUB-NORMAL TEMPS. WARMING WILL SET IN
FOR THE WEEKEND WITH MUCH WARMER CONDITIONS BY SUN AND MON. ECMWF
A BIT FASTER WITH THE WARMING AND BRINGS 70S INTO THE STATE BY
SUN...THE GFS A BIT SLOWER AND HOLDS THEM OFF UNTIL MON. EITHER
WAS A SIGNIFICANT PUSH OF WARMER AIR IS SLATED FOR LATER THIS
WEEKEND INTO EARLY NEXT.
&&
.AVIATION...24/06Z
ISSUED AT 1159 PM CDT SUN MAR 23 2014
RADAR IMAGERY SHOWS THAT LIGHT SNOW IS DEVELOPING ACROSS NORTHWEST
AND INTO CENTRAL IOWA...BUT AS ANTICIPATED LOW LEVEL DRY AIR IS
PROVING DIFFICULT FOR THE PRECIP TO OVERCOME AND SNOW IS NOT YET
BEING OBSERVED AT THE SURFACE. EXPECT THAT EVENTUALLY THE LOW
LEVELS WILL SATURATE AND CLOUDS HIGHS WILL LOWER...WITH MVFR CIGS
AND VSBYS POSSIBLE AFTER ABOUT SUNRISE AND INTO THE AFTERNOON
MONDAY. CONFIDENCE IS NOT PARTICULARLY HIGH IN TIMING OR CIG
HEIGHTS SO HAVE NOT TAKEN THEM TOO LOW IN THE 06Z TAFS. THESE
TRENDS WILL BE MONITORED CLOSELY OVERNIGHT.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MS MAR 14
SHORT TERM...FAB
LONG TERM...MS MAR 14
AVIATION...LEE
AREA FORECAST DISCUSSION
NWS DULUTH MN
348 AM CDT MON MAR 24 2014
.SHORT TERM...(TODAY THROUGH TUESDAY AFTERNOON)
ISSUED AT 345 AM CDT MON MAR 24 2014
MAIN CONCERNS IN THE SHORT TERM ARE CENTERED AROUND THE CHANCE FOR
SNOW SHOWERS ACROSS MOST OF THE NORTHLAND THIS AFTERNOON...WITH
LINGERING LIGHT SNOW POSSIBLE TONIGHT THROUGH TUESDAY AFTERNOON.
ATTENTION WAS ALSO ASSIGNED TO THE PERSISTENT COLD TEMPERATURES
AND BREEZY NW WINDS.
WEAK HIGH PRESSURE AT THE SFC CONTINUES TO INFLUENCE THE UPPER
MIDWEST THIS MORNING WITH THE RIDGE AXIS EXTENDING FROM THE CENTER
OF THE HIGH OVER ERN IA THROUGH MN INTO WRN NORTH DAKOTA. COLD NWLY
FLOW ALOFT REMAINS IN PLACE AND WILL HELP TRIGGER SNOW SHOWERS
OVER THE REGION THIS AFTERNOON. AN EMBEDDED S/W OVER THE DAKOTAS
THIS MORNING...WITH AN ASSOCIATED SFC INVERTED TROUGH AROUND SIOUX
CITY WILL MOVE E/SEWD TODAY. A SECOND FEATURE TO THE NORTH ALONG A
COLD FRONT WILL MOVE SWD INTO THE AREA TODAY AS WELL. THE
COMBINATION OF THESE TWO WAVES AND STEEPENING LOW LEVEL LAPSE
RATES WILL GENERATE SNOW SHOWERS ACROSS THE REGION. AMTS WILL
LIKELY NOT ADD UP TO MUCH...BUT SNOW SQUALL PARAMETER FROM THE
LATEST RUNS OF THE NAM AND RAP ARE BOTH AT LEVELS THIS AFTERNOON
THAT WOULD INDICATE POSSIBLE PERIODIC BURSTS OF MDT TO HVY SNOW.
LATEST RAP13 IS ALSO POINTING TOWARD AN AREA TO THE SOUTH ACROSS
CENTRAL MN AND NW WI WHERE STRONG UVV IN THE DGZ COULD ALSO LEAD
TO BRIEF LOCALIZED HVY SNOW WITH REDUCED VSBYS. THE COLD/DRY AIR
MASS WILL LIKELY INHIBIT ANY ACCUMULATION OVER AN INCH...AND KEEP
THE SNOW GENERALLY IN THE FORM OF LARGE DENDRITES.
THE COLD FRONT DROPPING IN FROM THE NORTH WILL ALSO TRIGGER SNOW
SHOWERS ACROSS THE NRN COUNTIES LATER THIS AFTERNOON AND ALLOW
LIGHT SNOW/FLURRIES TO LINGER OVER THE REGION INTO TUESDAY. HIGH
PRESSURE WILL BUILD IN FROM THE W/NW ON TUESDAY AND HELP LIMIT THE
COVERAGE OF SNOW SHOWERS...BUT SHOULD STILL HAVE ENOUGH CAA
OCCURRING THROUGH THE DAY TO WARRANT LOW CHC POPS.
AS THE HIGH PRESSURE BUILDS IN OVER THE NRN ROCKIES AND FRONT
RANGE IN ERN MONTANA TODAY A TIGHT SFC PRES GRADIENT WILL FORM
OVER THE NRN PLAINS AND UPPER MIDWEST. STEEP LOW LVL LAPSE RATES
WILL ALSO HELP MIX DOWN STRONGER WINDS ALOFT. EXPECT NW WINDS
SUSTAINED AROUND 15 MPH...AND GUSTS TO 25 MPH TODAY. WINDS REMAIN
BREEZY TONIGHT AND INCREASE AGAIN ON TUESDAY...SIMILAR TO TODAY.
AIR MASS TODAY WILL NOT BE AS COLD AS YESTERDAY...SO TEMPS WILL BE
ROUGHLY 5 DEG WARMER. THE ADDED CLOUD COVER TONIGHT WILL KEEP
TEMPS FROM FALLING TOO FAR BELOW ZERO. HOWEVER ON TUESDAY ANOTHER
SURGE OF ARCTIC AIR FROM THE NORTH WILL KEEP HIGHS IN THE
TEENS...A GOOD 15 TO 20 DEG BELOW AVERAGE.
.LONG TERM...(TUESDAY EVENING THROUGH SUNDAY)
ISSUED AT 345 AM CDT MON MAR 24 2014
THIS PERIOD WILL BE ACTIVE...WITH A SIGNIFICANT STORM POSSIBLE LATE
WEDNESDAY NIGHT INTO THURSDAY NIGHT.
THE PERIOD WILL START OUT RATHER QUIET WITH THE NORTHLAND BETWEEN
HIGH PRESSURE TO THE EAST AND A LOW TO THE WEST. IT WILL BE DRY AND
COLD TUESDAY NIGHT WITH LOW AROUND OR IN THE SINGLE DIGITS BELOW
ZERO.
INCREASING WAA AND A SHORTWAVE WILL LEAD TO A CHANCE FOR LIGHT SNOW
WEDNESDAY...WITH CHANCES GREATEST ACROSS FAR NORTHERN MINNESOTA.
LIGHT SNOW ACCUMULATIONS ARE EXPECTED WEDNESDAY...AND THE NORTH
SHORE COULD GET SEE SOME HIGHER AMOUNTS DUE TO ONSHORE FLOW WITH
COLD TEMPERATURES STILL IN PLACE.
DIFFERENCES AMONG THE MODELS START TO AMPLIFY WEDNESDAY NIGHT WITH
THE GFS/NAM FASTER MOVING A CENTRAL PLAINS LOW NORTHEAST. WE
FOLLOWED CLOSE TO THE SLOWER ECMWF WHICH HAS SUPPORT FROM THE GEM.
THE ECMWF DEVELOPS AN INVERTED TROUGH INTO NORTHEAST MINNESOTA FROM
THE LOW IN WESTERN KANSAS WEDNESDAY NIGHT...THEN THE SURFACE LOW
MOVES INTO IOWA ON THURSDAY AND TOWARD SOUTHERN LAKE MICHIGAN
THURSDAY NIGHT. SNOW SHOULD INCREASE IN COVERAGE AND INTENSITY LATE
WEDNESDAY NIGHT OVER THE EASTERN HALF OF THE NORTHLAND. THE ECMWF
DOES BRING SOME WARMER TEMPS INTO OUR SOUTHERN CWA WITH A MIX
POSSIBLE OVER SOUTHERN AREAS LATE WEDNESDAY NIGHT INTO THURSDAY.
TEMPS DO LOOK COOLER THAN PREVIOUS RUNS...AND WE HAVE A SNOW/SLEET
MIX GOING UNTIL THURSDAY AFTERNOON WHEN SOME RAIN COULD OCCUR FAR
SOUTH. WE INCREASED POPS QUITE A BIT WEDNESDAY NIGHT INTO THURSDAY
NIGHT OVER THE EASTERN HALF OF THE NORTHLAND. THE THREAT FOR
SIGNIFICANT SNOWFALL CONTINUES TO INCREASE OVER ABOUT THE EASTERN
HALF OF THE NORTHLAND. LOWERING STABILITY...INCREASING FGEN...AND
UPPER LEVEL DIVERGENCE FROM A COUPLED JET ARE ALL FORECAST OVER THE
NORTHLAND WEDNESDAY NIGHT INTO THURSDAY EVENING. MORE DETAILS WILL
BE ADDED AS WE PROGRESS THROUGH THE WEEK AND HOPEFULLY THE MODELS
WILL CONVERGE ON A SOLUTION.
THE LOW WILL MOVE OFF TO THE EAST FRIDAY...WITH SOME LIGHT SNOW
LINGERING OVER PORTIONS OF NORTHERN WISCONSIN. INCREASING WAA
SATURDAY INTO SUNDAY WILL BRING THE POTENTIAL FOR SOME LIGHT MIXED
PRECIPITATION. WE HAVE SOME LOW POPS OVER PORTIONS OF THE NORTHLAND.
THE ECMWF HAS BACKED OFF CONSIDERABLY ON ITS WARMING INTO NEXT
WEEKEND AND HAS A BAROCLINIC ZONE ACROSS THE REGION. TEMPERATURES
ARE FORECAST TO RISE FROM THE MID TWENTIES TO LOWER THIRTIES
WEDNESDAY TO THE UPPER THIRTIES TO MID FORTIES SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1235 AM CDT MON MAR 24 2014
THE NORTHERN EDGE OF AN AREAS OF LOW CLOUDS AND LIGHT SNOW WILL
DRIFT INTO CENTRAL MN...MOVING INTO THE KBRD AREA MAINLY AFTER 12Z.
THE LOWERING CEILINGS AND SNOW WILL OVER TAKE THE FORECAST AREA FROM
THE SOUTH...AS WELL AS THE NORTH THROUGH THE DAY MONDAY. KDLH IS
EXPECTED TO REMAIN BETWEEN THE TWO APPROACHING SYSTEMS UNTIL THE
LATE AFTERNOON. ANY ACCUMULATION IS EXPECTED TO BE LIGHT...WITH
AMOUNTS OF A DUSTING TO AROUND AN INCH THROUGH MONDAY EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 24 0 17 0 / 20 20 10 0
INL 19 -7 15 -5 / 30 20 20 0
BRD 27 2 20 -1 / 20 20 0 0
HYR 26 2 18 -8 / 30 20 20 0
ASX 26 4 17 -2 / 20 20 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...BJT
LONG TERM...MELDE
AVIATION...GRANING/MELDE
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
352 AM CDT MON MAR 24 2014
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 335 AM CDT MON MAR 24 2014
THE MAIN CHALLENGE THIS MORNING WILL BE PRECIP CHANCES AND BLOWING
SNOW POTENTIAL THIS AFTERNOON/EVENING IN THE NORTHERN VALLEY.
MODELS ARE IN VERY GOOD AGREEMENT THIS MORNING...WITH NO PREFERENCE.
FOR TODAY AND TONIGHT...YET ANOTHER MODIFIED ARCTIC COLD FRONT WILL
MOVE INTO THE NORTHERN VALLEY BY EARLY AFTERNOON...PROGRESSING
SOUTH THROUGH THIS EVENING. THERE WILL BE ABOUT 30-35KT TO MIX
EFFICIENTLY UP TO NEARLY 800MB BY LATER THIS AFTERNOON. THERE
SHOULD ALSO BE SCATTERED SNOW SHOWERS WITH A SHORTWAVE...AND
DEEPER LAYERED SATURATION AND LIFT. EXPECT SOME AREAS OF BLOWING
SNOW TO DEVELOP IN THE NORTHERN VALLEY...WITH MORE BLOWING SNOW
NEAR THE HEAVIER SNOW BAND FROM NORTHERN GRAND FORKS COUNTY INTO
MARSHALL COUNTY. NOT EXPECTING ANYTHING THAT WOULD WARRANT AN
ADVISORY...BUT WILL MENTION IN THE WEATHER GRIDS AND HIGHLIGHT
BLOWING SNOW THREAT IN THE HWO/WEATHER STORY. TEMPS SHOULD FALL IN
THE NORTH BY LATER THIS AFTERNOON ONCE COLD ADVECTION MOVES IN.
SNOW SHOWERS SHOULD LINGER FOR MOST AREAS THROUGH 6Z TONIGHT...AND
MOVE EAST BY TUE MORNING. WINDS WILL REMAIN ELEVATED OVERNIGHT
PREVENTING IT FROM GETTING TOO COLD...ALTHOUGH TEMPS WILL STILL
FALL WELL BELOW NORMAL FROM LOW LEVEL COLD AIR ADVECTION.
ON TUESDAY...IT WILL BE DRY AND CONTINUED COLD WITH HIGHS ABOUT
15-20 DEGREES BELOW NORMAL WITH COLD HIGH PRESSURE IN CONTROL.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 335 AM CDT MON MAR 24 2014
ON WEDNESDAY...ISENTROPIC LIFT AND MID LEVEL FRONTOGENESIS WILL
DEVELOP ALONG AND NORTH OF HIGHWAY 2. THERE WILL ALSO BE THE RIGHT
ENTRANCE REGION OF AN UPPER LEVEL JET...AND EXPECT A BAND OF LIGHT
SNOW IN THE NORTH. THIS SNOW SHOULD CONTINUE INTO WED NIGHT AS A
LARGER STORM DEVELOPS JUST SOUTH OF THE AREA. THERE COULD BE A
BAND OF 1-3 INCHES OF SNOW IN THE NORTH...WITH THE HIGHEST CHANCE
NEAR THE CANADIAN BORDER. TEMPS WILL WARM TO NEAR NORMAL IN THE
FAR SOUTH...AND REMAIN BELOW NORMAL IN THE NORTH WITH CLOUDS AND
SNOW MOVING IN.
FOR THURSDAY-SUNDAY...LARGE SCALE FLOW/LONG WAVE PATTERN SHOWS A
TRANSITION TAKING PLACE WITH NW FLOW FLATTENING AS HIGH LATITUDE
RETROGRESSION OCCURS. CPC D+3 TO D+8 SUPER-ENSEMBLES AND GFS360
5-WAVE SHOW THIS NICELY. AS ALWAYS THE DETAILS VARY FROM RUN-TO-
RUN AND HAVE TRIED TO MAINTAIN AS MUCH CONSISTENCY FROM PREVIOUS
FORECASTS AS POSSIBLE.
FOR THURSDAY MODELS GENERALLY AGREE WITH A OPEN 500 TROUGH WAVE AND
SURFACE LOW MOVING INTO THE WESTERN GREAT LAKES. 700MB FRONTOGENESIS
AND 500-300 MB DIV-Q WITH AMPLE RH SUPPORT MODEL QPF OVER SOUTHEAST
QUARTER OF CWFA. SURFACE HIGH RIDGES IN FOR A DRIER DAY FRIDAY.
FOR SATURDAY RETROGRESSION IN THE LONG WAVE ALLOWS FOR BUILDING
HEIGHTS OVER THE PLAINS. GEM-NH AND GFS FASTER THAN ECMWF/DGEX WHICH
WILL HAVE SOME BEARING ON THE ADVERTISED WARMUP. AS HIGH DEPARTS TO
THE EAST AND LOW PRESSURE DEVELOPS SOMEWHERE IN THE WESTERN HIGH
PLAINS A BOUNDARY FORMS ACROSS THE CWFA. CURRENT SUITE OF GUIDANCE
SUGGESTS 50S FOR THE SOUTH AND 30S ACROSS THE NORTH...OBVIOUSLY
HIGHLY DEPENDENT ON THE EXACT LOCATIONS. -SN FORECAST IN COOLER ZONE
TO THE NORTH.
THE LARGE SCALE FLOW TURNS MORE WEST/SOUTHWEST AT THE END OF THIS
PERIOD. WITH THE BOUNDARY SAGGING SLOWLY SOUTH AS HEIGHTS BUILD...
LOW PRESSURE FORMS IN THE PLAINS. PACIFIC MOISTURE STREAMS INTO THE
AREA. CURRENT GUIDANCE SUGGESTS THE NORTH/WEST PORTION OF THE CWFA
WILL SEE THE BEST RISK OF -RASN MIX. GUIDANCE TEMPS REMAIN IN
REMARKABLY GOOD AGREEMENT EVEN AT THIS RANGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1151 PM CDT SUN MAR 23 2014
EXPECT GENERALLY CLEAR SKY AND LIGHT WINDS TONIGHT INTO MONDAY
MORNING. SOME MID LEVEL MOISTURE WILL SPREAD INTO NRN ND/NW MN
LATER MON MORNING AHD OF COLD FRONT DUE TO ARRIVE TOWARD
DVL/GFK/TVF AREA 18Z-21Z PERIOD. WITH THE COLD FRONT...EXPECT GUSTY
NORTH WINDS AND SOME SNOW SHOWERS ALONG AND BEHIND FRONT FOR A FEW
HOURS. ALSO COULD BE MVFR CIGS. LATEST RAP GUIDANCE INDICATES ONLY
SPOTTY MVFR CONDITIONS...THUS WILL GO WITH LOW VFR CONDITIONS IN
THE FORECAST.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...DK
LONG TERM...EWENS/DK
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1151 PM CDT SUN MAR 23 2014
.UPDATE...
ISSUED AT 950 PM CDT SUN MAR 23 2014
FORECAST THINKING REMAINS VALID AND TEMPERATURES ARE THE ONLY REAL
CHALLENGE FOR TONIGHT. OBSERVATIONS INDICATE THAT TEMPS ARE BELOW
THE CURRENT EXPECTED VALUES ACROSS THE NORTHEASTERN FA...AND WILL
DROP MIN TEMPS A FEW DEGREES HERE. OTHERWISE...NO CHANGES PLANNED.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 315 PM CDT SUN MAR 23 2014
THE MAIN FORECAST CONCERNS WILL BE TEMPS AND SNOW SHOWER/BLOWING
SNOW POTENTIAL WITH A SHORTWAVE TROUGH DROPPING OUT OF CANADA ON
MONDAY.
A SHORTWAVE TROUGH CURRENTLY IN EASTERN MONTANA WILL CONTINUE TO
PROPAGATE SOUTHEASTWARD IN NORTHWEST FLOW ALOFT TONIGHT INTO SOUTH
DAKOTA. 12Z MODELS AND AVAILABLE MESOSCALE MODELS AGREE IN KEEPING
ANY PRECIP WITH THIS WAVE SOUTH OF THE FORECAST AREA...AND THUS WILL
KEEP DRY FORECAST IN PLACE. TEMPS TONIGHT WILL AGAIN BE COLDEST IN
THE SNOW-COVERED AREAS OF NORTHWESTERN MINNESOTA...WITH WARMER
READINGS FARTHER SOUTH WHERE SOME MID/HIGH CLOUD COVER IS EXPECTED.
ACROSS THE SNOW-COVERED AREAS...RATHER CLEAR SKIES ARE ANTICIPATED ONCE
THE DIURNAL CU DISSIPATE. THERE WILL BE SOME WEAK WARM
ADVECTION...SO THE QUESTION IS HOW COLD WILL TEMPS GET. DID LOWER
TEMPS A BIT INTO NORTHWEST MINNESOTA...BUT THIS IS SOMETHING TO
MONITOR THIS EVENING...AS WINDS WILL BE PRETTY LIGHT.
THE AFOREMENTIONED WAVE WILL CONTINUE TO PROPAGATE SOUTHEASTWARD ON
MONDAY WITH SOME WEAK LOW-LEVEL COLD ADVECTION DURING THE MORNING. A
STRONGER SYSTEM PASSING WELL TO THE NORTH ON MONDAY WILL DRAG A
COLD FRONT THROUGH THE AREA...WITH ADDITIONAL SHORTWAVE ENERGY
ROTATING SOUTHWARD INTO THE NORTHERN PLAINS HELPING TO AMPLIFY
NORTHWESTERLY FLOW ALOFT. WITH STEEPENING LOW-LEVEL LAPSE RATES
THROUGH THE DAY (AND SOME LOW-LEVEL INSTABILITY INDICATED ON MODEL
SOUNDINGS) IN THE COLD ADVECTION...SOME SNOW SHOWER ACTIVITY IS
EXPECTED. LIKE MANY OF THE COLD FRONTAL PASSAGES THIS COLD
SEASON...THE QUESTION WILL BE HOW STRONG WINDS CAN GET AND RELATED
BLOWING SNOW ISSUES. THERE IS EXPECTED TO BE ABOUT 25-30 KT WINDS
IN THE MIXED LAYER WITH THE STRONGEST SFC WINDS MID TO LATE
AFTERNOON IN THE STRONGEST COLD ADVECTION. ON THE OTHER
HAND...WITH THE SFC LOW WELL NORTH...3-HR PRESSURE RISES WILL NOT
BE VERY IMPRESSIVE AND THE PRESSURE GRADIENT IS NOT ALL THAT STRONG.
MAV/MET GUIDANCE IS GENERALLY 17-20 KTS IN THE 18-21Z TIME
FRAME...SO WILL BUMP UP WINDS A BIT. DID PUT SOME PATCHY BLOWING
SNOW IN FROM THE NORTHERN VALLEY INTO THE DEVILS LAKE BASIN DURING
THE AFTERNOON...WHERE SOME AREAS HAVE FRESH SNOW. SNOW SHOWER
ACTIVITY COULD HELP TO LOCALLY REDUCE VISIBILITY AS WELL. IN AREAS
WITH A FRESH SNOW PACK...THE CANADIAN BLOWING SNOW MODEL SUGGESTS
35 TO 40 KT WINDS WOULD BE NEEDED FOR SIGNIFICANT VISIBILITY
REDUCTIONS WITH NO FALLING SNOW...WHICH IS NOT ANTICIPATED.
THUS...CURRENTLY NOT EXPECTING WIDESPREAD CONCERNS...BUT WIND
SPEEDS AND BLOWING SNOW POTENTIAL WILL NEED TO BE MONITORED.
COOL HIGH PRESSURE WILL BUILD BACK IN FOR MONDAY NIGHT WITH ANY
SNOW SHOWER ACTIVITY DIMINISHING AS LARGE SCALE SUBSIDENCE
OVERSPREADS THE REGION AND HIGH PRESSURE APPROACHES. HOW QUICKLY SKIES
CLEAR WILL HAVE A LARGE IMPACT ON LOW TEMPS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 315 PM CDT SUN MAR 23 2014
HIGHS ON TUESDAY WILL BE WELL BELOW LATE MARCH AVERAGES...IN THE
TEENS AND 20S...WITH RATHER LIGHT WINDS UNDER THE SFC HIGH. WARM
ADVECTION WILL STRENGTHEN ON TUESDAY NIGHT KEEPING LOWS A LITTLE
MILDER...ESPECIALLY WEST.
THE LARGE-SCALE FLOW PATTERN FLATTENS ON WEDNESDAY WITH
STRENGTHENING EAST TO SOUTHEAST WINDS IN RESPONSE TO DEVELOPING LOW
PRESSURE IN THE HIGH PLAINS. WITH MODERATING LOW-LEVEL THERMAL
FIELDS...TEMPS SHOULD AT LEAST MODERATE CLOSER TO SEASONAL
AVERAGES...ESPECIALLY ACROSS THE SOUTH. THE GEM/NAM/GFS/ECMWF ALL
SHOW SOME LIGHT SNOW BREAKING OUT ON WEDNESDAY UP TOWARDS THE
CANADIAN BORDER WITH WEAK UPPER LEVEL ENERGY INTERACTING WITH THE
LOW TO MID-LEVEL BAROCLINIC ZONE AND PRONOUNCED 700-300 MB OMEGA.
OVERALL GEM/ECMWF/GFS IDEAS FOR THE WED NIGHT-SUN TIME PERIOD ARE
SIMILAR BUT THEY DIFFER IN TIMING AND TEMPS. 500 MB FLOW BECOMES
MORE ZONAL AS COLD POLAR LOW AT LEAST TEMPORARILY LIFTS NORTH. ONE
SHORT WAVE AND SURFACE LOW WILL RACE EAST ALONG THE CANADIAN BORDER
PRODUCING SOME LIGHT SNOW INTO WED NIGHT. ANOTHER STRONGER SHORT
WAVE AND SFC LOW WILL DEVELOP IN THE CENTRAL PLAINS INTO THE GREAT
LAKES THURSDAY. ECMWF IS FARTHER NORTHWEST AND A BIT SLOWER BUT
EVEN THAT MODEL KEEPS MOST OF THE PRECIP SOUTH AND EAST OF OUR FCST
AREA. WILL HOLD ONTO TO LOW POPS IN THE SOUTH AND EAST FCST AREA
THURSDAY FOR ANY SHIFT AGAIN NORTHWEST. GFS IS MUCH WEAKER WITH
SYSTEM AND ECMWF STRONGER. HIGH PRESSURE WILL DROP IN BEHIND IT FOR
A SHORT TIME THEN A WEAK SHORT WAVE WILL MOVE EAST FRI AFTN ALONG
THE BORDER...FOLLOWED BY ANOTHER SHORT WAVE WHICH WILL DIG A BIT
INTO THE CENTRAL PLAINS. MODELS HAVE TAKEN A BIT SLOWER APPROACH TO
THIS SYSTEM FOR APRIL 1ST. GOOD WARMUP AHD OF SYSTEM BUT THERMAL
BOUNDARY REMAINS IN THE FAR NORTH AND WILL BE A SIGNIFICANT TEMP
GRADIENT DEVELOPING FROM THE FAR NORTH TO THE SOUTHERN FCST AREA
SUNDAY. BLENDED MODEL TOOL GIVES SOME LOW POPS FOR NRN AREAS
SAT-SUN AND WILL LEAVE THEM THOUGH CONFIDENCE IS VERY LOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1151 PM CDT SUN MAR 23 2014
EXPECT GENERALLY CLEAR SKY AND LIGHT WINDS TONIGHT INTO MONDAY
MORNING. SOME MID LEVEL MOISTURE WILL SPREAD INTO NRN ND/NW MN
LATER MON MORNING AHD OF COLD FRONT DUE TO ARRIVE TOWARD
DVL/GFK/TVF AREA 18Z-21Z PERIOD. WITH THE COLD FRONT...EXPECT GUSTY
NORTH WINDS AND SOME SNOW SHOWERS ALONG AND BEHIND FRONT FOR A FEW
HOURS. ALSO COULD BE MVFR CIGS. LATEST RAP GUIDANCE INDICATES ONLY
SPOTTY MVFR CONDITIONS...THUS WILL GO WITH LOW VFR CONDITIONS IN
THE FORECAST.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...MAKOWSKI
LONG TERM...MAKOWSKI/RIDDLE
AVIATION...TG
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
412 AM CDT MON MAR 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 412 AM CDT MON MAR 24 2014
PER LATEST RADAR...AREA OF LIGHT SNOW OCCURRING THROUGH THE HEART OF
OUR CWA VERY EARLY THIS MORNING IS TRENDING TOWARD THE NORTH AND
EAST...AND PER LATEST RAP 13 ANALYSIS LOOKS TO BE ASSOCIATED WITH
FRONTOGENESIS LOCATED AROUND 800 MB. MODELS INDICATING THIS FRONTAL
FORCING TO SLIP TO THE EAST THROUGH THE MORNING HOURS...AND
ANTICIPATE THE OVERALL PRECIPITATION TREND TO FOLLOW SUIT WITH MOST
OF THE SNOW ENDING BY 15Z. VISIBILITIES WITH THE SNOW HAVE GENERALLY
BEEN REMAINING IN THE 2 TO 3 MILE RANGE...NOT ESPECIALLY HEAVY...SO
AM THINKING THAT ONLY A FEW TENTHS OF ADDITIONAL ACCUMULATION WILL
OCCUR WITH THE ACTIVITY...POSSIBLY UP TO AN INCH. AFTER THAT...DO
NOT THINK WE WILL SEE MUCH MORE ACTIVITY THROUGH THE REMAINDER OF
THE DAY...THOUGH HI RES MODELS INDICATE SOME POSSIBLE REDEVELOPMENT
IN OUR NORTH AND EAST DURING THE LATE AFTERNOON AND EARLY EVENING AS
ANOTHER SHORTWAVE/COLD FRONT DROP SOUTHWARD ACROSS THE AREA DURING
THAT TIME FRAME. WOULD BE SURPRISED THAT MUCH OF THIS WOULD ACTUALLY
ACCUMULATE...PROBABLY MORE IN THE FORM OF FLURRIES...THOUGH DID
INCLUDE SOME SLIGHT POPS OVER THAT AREA IN THE AFTERNOON AND
EVENING. TEMPERATURES WILL OF COURSE REMAIN BELOW NORMAL...WITH
HIGHS RUNNING MOSTLY IN THE 30S.
WILL SEE NORTHWESTERLY WINDS BEGIN TO INCREASE BY LATE AFTERNOON AND
REMAIN FAIRLY BREEZY THROUGH TONIGHT WITH THE COLD AIR ADVECTION
BEHIND THE FRONTAL PASSAGE. THIS WILL MODERATE TEMPERATURES SOMEWHAT
IN SPITE OF DECREASING CLOUDS...THOUGH STILL COLD WITH LOWS DROPPING
INTO THE TEENS OVERNIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 412 AM CDT MON MAR 24 2014
QUIET CONDITIONS CONTINUE THROUGH WEDNESDAY EVENING...WITH LOW LEVEL
TEMPERATURES GRADUALLY WARMING BACK TO ABOVE NORMAL LEVELS AHEAD OF
NEXT SYSTEM WHICH MOVES IN LATE WEDNESDAY NIGHT. SURFACE RIDGE MOVES
INTO WESTERN PARTS OF THE AREA TUESDAY...WITH MOSTLY SUNNY SKIES AND
DECREASING NORTHWEST WINDS THROUGH THE DAY. MINIMAL SNOWFALL EARLY
THIS MORNING EXPECTED TO HAVE LITTLE IMPACT BY TUESDAY...SO FAVORED
SLIGHTLY WARMER GUIDANCE NUMBERS FROM THE UPPER 20S IN SOUTHWEST MN
TO MID 30S THROUGH THE MISSOURI RIVER VALLEY. SHOULD SEE TEMPS DROP
OFF QUICKLY TUESDAY EVENING...THEN LEVEL OFF OR SLIGHTLY RECOVER IN
THE LATTER HALF OF THE NIGHT AS THE RIDGE AXIS SHIFTS EAST AND SOUTH
FLOW PICKS UP.
WEDNESDAY SHOULD BE ANOTHER MILD DAY...AS 925MB TEMPERATURES WARM
INTO THE 5-10C RANGE NORTHEAST...TO MID TEENS IN SOUTHWEST PARTS OF
THE CWA. AGAIN FAVORED WARMING A BIT MORE OVER PREVIOUS FORECAST...
WITH HIGHS FROM AROUND 50 ACROSS SOUTHWEST MN TO LOWER 60S IN THE
MISSOURI VALLEY. THIS FAIRLY CLOSE TO RAW MODEL CONSENSUS...WITH
NAM/GFS ON THE COOLER SIDE OF THE SPECTRUM...ECMWF NEAR THE MIDDLE
AND GEM THE WARMEST AMONG THE RAW MODEL NUMBERS.
MODELS CONTINUE TO SHOW WAVE MOVING ACROSS THE REGION WEDNESDAY NIGHT
INTO THURSDAY NIGHT...WITH GFS ON THE FAST SIDE BUT TRENDING TOWARD
SLOWER ECMWF/GEM TIMING. HAVE LEANED MORE TOWARD THIS SLOWER TIMING
FOR NOW...WHICH KEEPS MUCH OF THE AREA WARMER WEDNESDAY NIGHT WITH
PRECIP EXPECTED TO HOLD OFF UNTIL LATTER HALF OF THE NIGHT. THURSDAY
SHOULD BE THE WETTEST PERIOD FOR MOST AREAS...ESPECIALLY EAST WHERE
PRECIP HAS GREATER CHANCE OF LINGERING INTO THURSDAY NIGHT. PRECIP
TYPE WILL BE IN QUESTION...LARGELY DEPENDENT ON LOW LEVEL THERMAL
PROFILES WHICH ARE NOT ENTIRELY CLEAR CUT GIVEN DISCREPANCIES IN WAVE
TIMING. GENERALLY EXPECT MUCH OF THE AREA TO REMAIN LIQUID THROUGH
LATE WEDNESDAY NIGHT AND THURSDAY MORNING...WITH AREAS NORTHWEST OF
LAKE ANDES-MITCHELL-BROOKINGS MORE LIKELY TO SEE RAIN/SNOW MIX OR
TOTAL TRANSITION TO SNOW PRIOR TO 18Z THURSDAY. THREAT FOR SNOW WILL
EXPAND TO THE EAST AND SOUTH THROUGH THE AFTERNOON AS COLD ADVECTION
CONTINUES BEHIND THE DEPARTING COLD FRONT...THOUGH AMOUNTS CURRENTLY
EXPECTED TO REMAIN ON THE LIGHT SIDE AROUND AN INCH OR LESS OVER THE
WESTERN AND NORTHERN PARTS OF THE AREA.
WITH SLOWER TIMING...WILL CARRY CHANCE OF MAINLY LIGHT SNOW ALONG AND
EAST OF I-29 INTO THURSDAY NIGHT...FOLLOWED BY DRY AND INCREASINGLY
MILD CONDITIONS THROUGH NEXT WEEKEND AS MORE ZONAL FLOW PATTERN SETS
UP ACROSS THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1223 AM CDT MON MAR 24 2014
LOW PRESSURE WILL MOVE ACROSS THE AREA LATE TONIGHT AND EARLY
MONDAY. THIS SYSTEM WILL GIVE A BROAD AREA OF LIGHT SNOW TO MUCH
OF THE AREA...WITH MVFR TO IFR CONDITIONS PREVAILING ONCE THE SNOW
BEGINS. TRIED TO TIME THE ARRIVAL AND DEPARTURE OF THE SNOWFALL IN
OUR THREE TAF SITES...BUT OVERALL A BULK OF THE SNOW WILL FALL IN
THE LATE EVENING THROUGH LATE NIGHT HOURS. ON MONDAY...THE WINDS
WILL SHIFT TO THE NORTHWEST EARLY IN THE DAY...AND A SECOND
DISTURBANCE WILL MOVE THROUGH GIVING SOME AREAS OF LIGHT SNOW. BUT
RIGHT NOW THE SNOWFALL LOOKS SPOTTY ENOUGH TO NOT INCLUDE A
MENTION IN THE TAF SITES.
&&
.FIRE WEATHER...
ISSUED AT 412 AM CDT MON MAR 24 2014
ABOVE NORMAL TEMPERATURES IN THE 50S AND LOWER 60S...ALONG WITH
INCREASING SOUTH WINDS WILL LEAD TO ELEVATED FIRE DANGER ACROSS PARTS
OF THE AREA ON WEDNESDAY. AT THIS TIME...MINIMUM HUMIDITY LEVELS ARE
EXPECTED TO HOLD IN 30-45 PERCENT RANGE IN AREAS WITH THE STRONGEST
WINDS...WHICH SHOULD LIMIT THREAT OF RED FLAG CONDITIONS. HOWEVER
WILL MONITOR THIS CLOSELY OVER THE NEXT COUPLE OF DAYS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JM
LONG TERM...JH
AVIATION...MJ
FIRE WEATHER...JH
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1118 PM CDT SUN MAR 23 2014
.AVIATION...
/06Z TAFS/
The Brady, Junction, and Sonora terminals can expect MVFR conditions
overnight as temperatures cool and and winds diminish. Guidance for
San Angelo and Abilene has CIGS moving back in, but keeps them
higher. VFR conditions will likely prevail. the San Angelo terminal
may see a few hours of MVFR CIGS and will start them at low end
VFR(BKN030). Looks like stratus breaks up quickly by late Monday
morning and going with VFR conditions across West Central TX Monday
afternoon and evening.
21
&&
.PREV DISCUSSION... /ISSUED 833 PM CDT SUN MAR 23 2014/
UPDATE...
The latest satellite and radar data indicate showers have moved east
of our area. The latest RUC data indicate precipitation will likely
remain east of our area for the remainder of tonight and tomorrow
morning. Therefore, I removed showers we had for our southern
counties for the remainder of tonight and for tomorrow morning.
Plus, I adjusted sky conditions for the remainder of tonight and
tomorrow morning to reflect satellite trends and model data.
Huber
PREV DISCUSSION... /ISSUED 633 PM CDT SUN MAR 23 2014/
AVIATION...
/00Z TAFS/
Brady, Junction, and Sonora can expect MVFR conditions overnight as
temperatures cool and and winds diminish. Guidance for San Angelo
and Abilene has CIGS moving back in, but keeps them higher. VFR
conditions will likely prevail. San Angelo looks to be on the edges,
so MVFR conditions cannot be ruled out, especially closer to sunrise.
Reimer
PREV DISCUSSION... /ISSUED 323 PM CDT SUN MAR 23 2014/
SHORT TERM...
(Tonight and Monday)
Lift associated with the RRQ of a 250mb 120+ knot jet streak
interacted with elevated instability and a northward sloping cold
frontal boundary to give the area some thunderstorms earlier
today. Most of this activity has moved east of the area this
afternoon. A surge of colder air moved in this morning, and along
with the rain received around the area, kept temperatures 25 to 30
degrees below normal this afternoon.
For tonight, thinking hasn`t changed much from the previous
forecast. We will see winds become light and variable across the
region as sfc high pressure settles in across Texas. At this time
there is still expected to be low clouds across the area, keeping
ideal radiational cooling conditions from setting up. Therefore,
have kept the temperatures near the previous forecast with lows
getting into the 30s across much of the area, but not down to the
freezing mark. Will keep a small area of low end slight chance
PoPs for the southern tier of the CWA this morning into Monday
morning for any leftover activity that is stubborn to leave the
area.
Monday, a thin, but stubborn layer of low level clouds may hang
around for a few hours after sunrise, but we should see breaks
during the afternoon. The increasingly stronger Spring sun, should
help warm temperatures back into the 60s to near 70 areawide, as
winds turn to the south during the day.
20
LONG TERM...
Next rain chance is late Tuesday night into Wednesday as an upper
trough approaches and moves over from the West. Water Vapor loop
indicates the upper low developing along the coast in N. California.
The upper low is expected to dig south into Baja California before
heading east over Texas. Both the EC and GFS have been consistent in
developing the upper low for the last several days. Model rainfall
amounts have come up to: 1/10 inch in the GFS, 2/10 inch in the EC.
The NAM run is also coming into the picture, with a stronger upper
trough bringing in a large area of 1/2 inch totals. Have increased
pops slightly, but keeping chances in the 30 to 50 percent range.
Drier air Thursday and Friday with breezy west winds. Main impact
will be elevated fire weather potential and, of course, evaporation
of received rainfall Wednesday. Could see an isolated dryline
thunderstorm east/southeast of the Concho Valley Thursday, but did
not include due to limited potential. A dry cold front may move in
late Friday afternoon/evening, bringing slightly cooler but dry
conditions into the weekend.
04
FIRE WEATHER...
Expect quiet conditions through the middle of the week, as
slightly cooler temperatures will keep RH values from bottoming
out too much.
Look for elevated fire weather conditions by Thursday and Friday.
Temperatures warm significantly, resulting in RH values dropping
into the 10 to 15 percent range in some cases. At the same time,
west winds will increase to 10 to 20 mph, with the strongest winds
across areas west of a Sweetwater to Sonora line. 700mb-500mb
winds between 35 and 50 knots each day during the afternoon would
support gusts over 35 mph during the afternoon hours behind the
dryline where mixing will be greatest. The dryline should make it
as far as a Sweetwater to San Angelo to Sonora line Thursday, and
possibly push through most of the area Friday.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 37 70 38 66 48 / 5 0 5 5 10
San Angelo 37 69 44 68 51 / 5 0 5 5 20
Junction 41 65 45 70 51 / 10 5 10 5 20
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1105 PM CDT SUN MAR 23 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 339 PM CDT SUN MAR 23 2014
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED NORTHWEST FLOW FROM BRITISH COLUMBIA INTO THE MID-ATLANTIC.
THERE ARE A VARIETY OF SHORTWAVES SEEN ON WATER VAPOR THAT ARE
FORECAST TO IMPACT THE AREA OVER THE NEXT COUPLE OF DAYS...ONE
OVER MONTANA...ANOTHER IN CENTRAL ALBERTA...A SHEARED OUT ONE
ALONG THE NUNAVUT/ALBERTA/SASKATCHEWAN BORDER...AND A FINAL ONE
WAY TO THE NORTH OVER THE CANADIAN ARCHIPELAGO. OBSERVATIONS SOME
SNOW AHEAD OF MOST OF THESE SHORTWAVES EXCEPT FOR THE LAST ONE.
PLENTIFUL ARCTIC AIR ALSO EXISTS OVER NUNAVUT INTO THE CANADIAN
ARCHIPELAGO WHERE TEMPERATURES WERE 15 TO 30 BELOW ZERO THIS
MORNING. OVER THE FORECAST AREA...A LARGE AREA OF CANADIAN HIGH
PRESSURE IS IN PLACE. PLENTIFUL DRY AIR EXISTS WITH THIS
HIGH...REFLECTED BY 12Z RAOBS INDICATING PRECIPITABLE WATER VALUES
OF 0.1-0.2 INCHES OR 30-50 PERCENT OF NORMAL. AS A RESULT...SKIES
HAVE BEEN MOSTLY SUNNY TODAY...THOUGH DIURNAL STRATOCUMULUS HAS
DEVELOPED WEST OF THE MS RIVER. DESPITE THE SUN...TEMPERATURES
HAVE ONLY CLIMBED INTO THE MID TEENS TO MID 20S...DUE TO
UNSEASONABLY COLD 925MB TEMPS OF -14 TO - 17C PER 12Z RAOB DATA.
DESPITE THAT WE ARE NOW WITHIN 24 HOURS OF THE EXPECTED MONDAY
SNOW...THE FORECAST REMAINS VERY UNCERTAIN. MUCH OF THE UNCERTAINTY
RELATES TO THE MONTANA AND CENTRAL ALBERTA SHORTWAVES. THE 23.12Z
NAM FOLLOWS SUIT WITH MOST OF ITS PREVIOUS RUNS...ALSO SIMILAR TO
THE 23.12Z CANADIAN AND 23.19Z RAP...NEARLY PHASING THE TWO
SHORTWAVES AND BRINGING THEM THROUGH THE AREA MONDAY MORNING. A WARM
ADVECTION WING DEVELOPS AHEAD OF THEM...AFFECTING THE FORECAST AREA
LATE TONIGHT THROUGH EARLY MONDAY AFTERNOON. LOCATIONS ACROSS
NORTHEAST IOWA WOULD SEE THE HEAVIEST PRECIPITATION ALONG THE TRACK
WITH 1-3 INCHES COMMON PER NAM COBB OUTPUT. ON THE OTHER SIDE OF
THIS IS THE 23.12Z GFS/ECMWF WHICH ARE MUCH DRIER SCENARIOS...
ESPECIALLY THE ECMWF AS IT KEEPS THE TWO SHORTWAVES UNPHASED. SOME
OF THE DRIER LOOK IS ALSO A REFLECTION OF THE SHORTWAVES RUNNING
INTO THE CURRENT DRY AIRMASS IN PLACE. GIVEN THE SPREAD OF SCENARIOS
AND EACH ONE EQUALLY PLAUSIBLE...FELT A COMPROMISE IS WARRANTED...
WHICH IS SIMILAR TO THE PREVIOUS FORECAST. THIS RESULTS IN ABOUT 1-2
INCHES MAINLY WEST OF THE MS RIVER WITH LESS THAN 1 INCH EAST.
AFTER THE MONTANA/CENTRAL ALBERTA SHORTWAVES PASS EARLY IN THE
AFTERNOON...ATTENTION THEN FOCUSES ON A COLD FRONT DROPPING
SOUTHEAST TOWARDS THE FORECAST AREA IN THE AFTERNOON...ASSOCIATED
WITH THE NEXT SHORTWAVE DROPPING OUT OF
NUNAVUT/ALBERTA/SASKATCHEWAN. A SURGE OF WARMER 925MB AIR OF -4 TO
-7C AHEAD OF THE FRONT PLUS WHAT MIGHT BE A PERIOD OF SUN SHOULD
PUSH TEMPERATURES INTO THE 30S. LINGERING MOISTURE AROUND COMBINED
WITH THE APPROACHING SHORTWAVE AND COLD FRONT WILL YIELD A STEEP LOW
LEVEL LAPSE RATE SITUATION...RESULTING IN A BAND OF SCATTERED TO
PERHAPS NUMEROUS SNOW SHOWERS BY LATE IN THE AFTERNOON. THIS
SCENARIO IS WELL AGREED UPON BY MODELS. COULD SEE A QUICK 1/2 TO 1
INCH FROM THIS SNOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 339 PM CDT SUN MAR 23 2014
AFTER ALL OF THE UNCERTAINTY IN THE SHORT TERM...MODELS GET MORE IN
AGREEMENT FOR MONDAY NIGHT THROUGH WEDNESDAY...PRIOR TO THE NEXT
SYSTEM EXPECTED TO IMPACT THE REGION ON THURSDAY.
THE SHORTWAVE CURRENTLY ALONG THE NUNAVUT/ALBERTA/SASKATCHEWAN
BORDER IS PROGGED TO DROP THROUGH THE AREA LATE MONDAY EVENING. THIS
SHORTWAVE COMBINED WITH CONTINUED STEEP LOW LEVEL LAPSE RATES AHEAD
OF IT WILL CONTINUE TO YIELD THE POTENTIAL FOR SNOW SHOWERS. MUCH OF
THE SNOW SHOULD END BY 08Z TUE. IN THE WAKE OF THIS SHORTWAVE A
SURGE OF COLDER 925MB AIR COMES IN WITH TEMPS DROPPING TO -8 TO
-12C. NORTHWEST WINDS INCREASE AS WELL. EVEN COLDER AIR FOLLOWS FOR
TUESDAY MORNING AS THE SHORTWAVE OVER THE CANADIAN ARCHIPELAGO
PLUNGES SOUTH THROUGH THE FORECAST AREA. 925MB TEMPS FALL TO -12 TO
-15C AT A MINIMUM BY 15Z TUE...WITH THE 23.12Z GFS/NAM EVEN
SUGGESTING -15 TO -18C. A BRISK NORTHWEST WIND ACCOMPANIES THIS
ARCTIC AIR SHOT...SO NEEDLESS TO SAY...TUESDAY LOOKS LIKE ANOTHER
CHILLY DAY SIMILAR TO TODAY AND POSSIBLY EVEN SLIGHTLY COLDER. THE
ONLY POSITIVE IS THERE SHOULD BE A DECENT AMOUNT OF SUN INTERMIXED
WITH DAYTIME STRATOCUMULUS. HAVING A COLD TUESDAY...RECENT LIGHT
SNOW AND AN ARCTIC SURFACE HIGH PRESSURE RIDGE MOVING ACROSS AT
NIGHT SPELLS POTENTIAL FOR REALLY CHILLY CONDITIONS TUESDAY
NIGHT...PARTICULARLY OVER WISCONSIN. A FEW BELOW ZERO READINGS SEEM
LIKELY IN CENTRAL WISCONSIN. TEMPERATURES MAY CLIMB WEST OF THE
RIVER LATE AS RETURN FLOW SETS UP THERE.
A PATTERN CHANGE IS SET TO TAKE HOLD FOR WEDNESDAY AND BEYOND AS A
SERIES OF FAIRLY VIGOROUS LONG WAVE TROUGHS COME OFF THE PACIFIC AND
MARCH THEIR WAY ACROSS THE U.S..
THE FIRST LONG WAVE TROUGH COMING INTO THE WESTERN U.S. ON WEDNESDAY
CAUSES UPPER RIDGING TO BUILD OVER THE FORECAST AREA DURING THE
AFTERNOON. VERY STRONG WARM ADVECTION IS SUGGESTED BY MODELS BETWEEN
12Z WED AND 00Z THU WITH 925-850MB TEMPS CLIMBING AROUND 8C AREA
WIDE. THIS WARMER AIR COMES IN ON A STRENGTHENING LOW LEVEL JET WITH
THE ECMWF AND NAM DEPICTING 925MB WINDS REACHING 40 KT OVER THE
FAVORED WIND PRONE AREAS BY 00Z. GOOD MIXING ON SOUNDINGS TOO
SUGGESTING POTENTIAL NEED FOR ADVISORY DUE TO GUSTS. THERE HAVE BEEN
SUGGESTIONS TOO FROM THE GFS/SREF OF ISENTROPICALLY INDUCED SNOW
NORTH OF I-90 IN WI DURING THE AFTERNOON AS THAT LOW LEVEL JET
INCREASES. THE ECMWF/NAM REMAIN DRY...THOUGH. FOR NOW HAVE KEPT IN
SOME LOW CHANCES. WEDNESDAY NIGHT LOOKS BREEZY WITH NEAR STEADY
TEMPERATURES AS LOW LEVEL MOISTURE GRADUALLY INCREASES. THERE COULD
BE ENOUGH ISENTROPIC LIFT TO GENERATE SOME LIGHT PRECIP...WHICH WITH
A WARM LAYER PLAYING HAVOC WITH THE TYPE...A WINTRY MIX IS POSSIBLE
MAINLY NORTH OF I-94. THE WEATHER THEN GETS MUCH MORE INTERESTING
FOR THURSDAY AND POSSIBLY INTO FRIDAY...RESULTING FROM THE STRONG
SHORTWAVE AT THE BASE OF THE TROUGH LIFTS THROUGH THE FORECAST AREA.
STILL PLENTY OF MODEL SPREAD ON THE TIMING AND STRENGTH OF THIS
SHORTWAVE...WITH THE GFS REMAINING MOST PROGRESSIVE AND THE ECMWF
SLOWEST. EITHER SOLUTION BRINGS UP PLENTY OF GULF MOISTURE...AND THE
PREVIOUS FORECAST THINKING OF 0.5-1 INCH OF LIQUID QPF STILL LOOKS
REASONABLE. MUCH OF THE QPF LOOKS TO COME ON THE DEFORMATION SIDE OF
THE SYSTEM...WHICH APPEARS TO BE SNOW ON THE NORTHWEST SIDE AND RAIN
ON THE SOUTHEAST SIDE. THE ECMWF SOLUTION BEING STRONGER COULD
PRODUCE AT LEAST ADVISORY IF NOT WARNING SNOWFALL AMOUNTS. PLENTY OF
WIND TOO IN THE ECMWF SCENARIO TO ADD TO THE SNOW HAZARD. THE RAIN
TOO COULD LEAD TO RUNOFF PROBLEMS.
AFTER THE THURSDAY/FRIDAY SYSTEM PASSES...UPPER RIDGING LOOKS TO
BUILD BACK INTO THE REGION FOR THE WEEKEND AS THE NEXT UPPER TROUGH
COMES INTO THE WESTERN U.S.. THE WEEKEND FOR THE MOST PART LOOKS DRY
WITH A WARMING TREND AS THE RIDGE BUILDS IN. THE WARMING WILL REALLY
BE NOTICED ON SUNDAY AS 850MB STANDARDIZED ANOMALIES FROM THE 23.12Z
ECMWF/GFS REACH +2... SOMETHING NOT SEEN FOR MUCH OF THE WINTER OR
SPRING THUS FAR. WITH A BREEZY SOUTHWEST WIND...HIGHS IN THE 50S
WITH A FEW 60S COULD OCCUR. SEE THE HYDROLOGY DISCUSSION BELOW FOR
IMPACTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1105 PM CDT SUN MAR 23 2014
CONFIDENCE LOWERING WITH THE SNOW CHANCES FOR KRST FROM A SHORTWAVE
MOVING ACROSS THE NORTHERN PLAINS. MESO MODELS AND RADAR TRENDS
SUGGEST ANY -SN WOULD STAY WELL SOUTH/SOUTHWEST NOW. WILL SHAPE
FORECAST THIS WAY.
ANOTHER SHORTWAVE TROUGH THEN MOVES IN FOR THE AFTERNOON/EARLY
EVENING HOURS. HEFTY LOW LEVEL LAPSE RATES WILL PROVIDE SOME NEAR
SFC INSTABILITY AND MODELED SOUNDINGS SUGGEST AMPLE SATURATION FOR
CLOUD/PCPN PRODUCTION. EXPECT THIS ACTIVITY TO BE MORE
CELLULAR/SHOWERY. THIS COULD RESULT IN BRIEF PERIODS OF IFR/MVFR
VSBYS IN -SN. WILL LIKELY COVER WITH -SHSN CONDITIONS FOR
NOW...LETTING RADAR TRENDS HELP REFINE TIMING IN LATER
FORECASTS/UPDATES.
&&
.HYDROLOGY...
ISSUED AT 339 PM CDT SUN MAR 23 2014
ISSUE 1...TREMPEALEAU RIVER AT DODGE. THE RIVER HAS BEEN CLIMBING
AT DODGE SINCE ABOUT 00Z ON THE 21ST...DESPITE A FEW COLD DAYS
NOW WHICH HAS CAUSED GAUGES UPSTREAM TO FALL. THERE IS ICE ON THE
RIVER...THUS THE THINKING IS THERE MIGHT BE AN ICE JAM DOWNSTREAM
OF DODGE. HAVE ISSUED A RIVER FLOOD WARNING AT DODGE WHEN IT
REACHED 8.9 FT...HOWEVER...NOW THE RIVER JUST STARTED TO FALL
SLIGHTLY. GIVEN THE UNCERTAINTY ON HOW THIS POSSIBLE ICE JAM IS
AFFECTING RIVER FLOW...WILL BE KEEPING THE WARNING GOING.
ISSUE 2...THE WARM UP AND PRECIPITATION FOR THURSDAY AND POSSIBLY
INTO FRIDAY. MODELS ARE SUGGESTING BETWEEN 1/2 - 1 INCH OF LIQUID
EQUIVALENT...HEAVIEST OVER THE NORTHWEST HALF OF THE FORECAST
AREA. RIGHT NOW IT APPEARS THE RAIN ASPECT TO THIS PRECIPITATION
WOULD OCCUR OVER THE SOUTHEAST HALF OF THE FORECAST AREA...WHICH
ALTHOUGH MOSTLY SNOW FREE HAS PLENTY OF FROST IN THE GROUND TO
TURN MUCH OF THE RAIN TO RUNOFF. NEEDLESS TO SAY...WORTH
MONITORING.
ISSUE 3...ABOVE NORMAL WARMTH FOR SUNDAY. WITH TEMPERATURES
CLIMBING INTO THE 50S AND POSSIBLY 60S...WE WILL REALLY HAVE TO
WATCH FOR POSSIBLE RIVER FLOODING ALONG THE TREMPEALEAU AND
BLACK GIVEN DEEPER SNOWPACK IN THE HEADWATER AREA. ANY SNOW FROM
THURSDAY/FRIDAY COULD ALSO CAUSE FLOODING CONCERNS DUE TO RAPID
MELTING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RIECK
HYDROLOGY....AJ
AREA FORECAST DISCUSSION
NWS DES MOINES IA
655 AM CDT MON MAR 24 2014
.SYNOPSIS...
ISSUED AT 316 AM CDT MON MAR 24 2014
WEAK TROUGH WILL MOVE ACROSS THE STATE TODAY FOLLOWED ONE LAST
SURGE OF POLAR AIR ON TUE AS HIGH PRESSURE DROPS SOUTHEAST ACROSS
THE REGION. PATTERN WILL UNDER GO A CHANCE ONCE THE EAST COAST LOW
PUSHES OUT OF THE WAY. UPPER RIDGE WILL STRENGTHEN WITH MORE
INFLUENCE FROM THE SOUTHERN STREAM. LOW PRESSURE WILL MOVE OUT OF
THE ROCKIES THROUGH IA THU NIGHT WITH ONLY A WEAK PUSH OF COOLER
AIR BEHIND IT WITH THE NEXT HIGH BEING MORE PACIFIC IN NATURE.
&&
.SHORT TERM /TODAY/...
ISSUED AT 316 AM CDT MON MAR 24 2014
DIFFICULT FORECAST FOR WHAT I BELIEVE WILL BE A LIGHT SNOW EVENT.
RADAR HAS BEEN SHOWING A BAND OF LIGHT SNOW FROM WEST OF SAC CITY
THROUGH THE DES MOINES METRO AREA THEN SOUTHEAST TO ABOUT CORYDON.
SOUNDINGS SHOW A DRY LAYER NEAR THE SURFACE AND A QUICK CHECK OF
SNOWFALL AFTER THREE AND A HALF HOURS OF SNOWFALL REVEALS DRY AIR
NEAR THE SURFACE IS INDEED IN PLACE. THERE IS BARELY A TENTH OF AN
INCH OF SNOW ON THE GROUND AT THE OFFICE. THERE ARE A LOT OF
PROBLEMS WITH THIS SYSTEM WHICH ARE GIVING MODELS FITS. FIRST IS
THE DISTINCT DRY LAYER NEAR THE SURFACE. THIS WILL IMPROVE SOME
THIS MORNING AS MOISTURE SATURATES A DEEPER LAYER. THE PROBLEM...IF
YOU CAN BELIEVE THE MODELS AT ALL IS THAT IT WILL COME IN SEVERAL
BOUTS. ANY FORCING THAT COMES ACROSS BEFORE WE CAN SATURATE WILL
YIELD VERY LITTLE SNOWFALL. HOWEVER IN THE PERIOD FROM MID MORNING
THROUGH EARLY AFTERNOON MANY LOCATIONS WILL LIKELY PICK UP AROUND AN
INCH PERHAPS LOCALLY TWO. ALL THE HI-RES MODELS EXPAND THE PRECIP
OVER OUR FORECAST AREA BY 18Z SO I FEEL CONFIDENT IS EXPANDING POPS
ACROSS THE AREA BUT THE NAM12 HAS HIGHER SNOWFALL IN THE NORTH
CENTRAL TO NORTHEAST WHILE THE HRRR HAS A CORRIDOR OF HIGHER AMOUNTS
ALONG AND EAST OF THE I-35 CORRIDOR. OTHER HI-RES MODELS VARY FROM
ALMOST NOTHING AT ALL BEING A LITTLE SLOWER IN MOVING THE EXPANSION
EAST.
I TRIED TO TIE HIGHER AMOUNTS TO LOCATIONS WHERE IT APPEARED FORCING
WOULD BE STRONGER FOR AT LEAST SEVERAL HOURS AND WHERE MOISTURE WAS
DEEPER.
AS FOR TEMPS...WENT BELOW GUIDANCE BY UP TO A CATEGORY. I CANNOT SEE
US CLIMBING MUCH TODAY GIVEN THE CLOUD COVER AND PRECIP. A CHECK OF
ROAD SURFACE TEMPS INDICATES ROAD SURFACES HAVE COOLED TO WELL BELOW
FREEZING SO TO BE PROACTIVE WE WILL HAVE A SPECIAL WEATHER STATEMENT
OUT TO INDICATE THE POTENTIAL FOR SLICK SPOTS.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 316 AM CDT MON MAR 24 2014
AS THE TROUGH PULLS AWAY...SNOW WILL END FROM WEST TO EAST
TONIGHT. A SECONDARY S/WV WILL BRING SOME LIGHT SNOW LATER
TONIGHT AND SLOW THE EASTWARD PROGRESS OF THE ENDING...BUT ALL
SHOULD BE OUT OF THE CWA BEFORE MORNING.
COLD HIGH PRESSURE WILL SETTLE IN BEHIND THE TROUGH AND KEEP TEMPS
WELL BELOW NORMAL FOR TUE INTO TUE NIGHT. CHANGES ARE IN THE
WORKS AS THE PATTERN SHIFTS NORTH. HEIGHTS BUILD INTO THE CENTRAL
U.S. WITH THE NORTHERN STREAM BEING PUSHED TO THE NORTH OF IA. THE
SOUTHERN STREAM WILL HAVE MORE INFLUENCE WITH TEMPS REBOUNDING
QUICKLY ON WED AND THU. KEPT THE THUNDER IN THE FORECAST AND HAVE
MOVED IT INTO THE SWRN ZONES LATE WED NIGHT WITH STRONG WAA AND
ARM FRONT JUST SOUTH OF THE CWA. WIDESPREAD RAIN AND ISOLD THUNDER
ON TAP FOR A GOOD PART OF THE CWA THU WITH ELEVATED CAPE OVER THE
SOUTH REACHING ABOUT 500 J/KG. LOW WILL PULL OUT THU NIGHT WITH A
MIX OF -RASN. ECMWF CONTINUES TO BE MORE INTENSE WITH THIS
SYSTEM...THOUGH UNCERTAINTY REMAINS...IT WILL NEEDED TO BE
MONITORED FOR THE POTENTIAL OF A NARROW BAND OF HEAVIER SNOW
BEHIND THE LOW.
FRIDAY WILL BE COOLER WITH SUB-NORMAL TEMPS. WARMING WILL SET IN
FOR THE WEEKEND WITH MUCH WARMER CONDITIONS BY SUN AND MON. ECMWF
A BIT FASTER WITH THE WARMING AND BRINGS 70S INTO THE STATE BY
SUN...THE GFS A BIT SLOWER AND HOLDS THEM OFF UNTIL MON. EITHER
WAS A SIGNIFICANT PUSH OF WARMER AIR IS SLATED FOR LATER THIS
WEEKEND INTO EARLY NEXT.
&&
.AVIATION...24/12Z
ISSUED AT 655 AM CDT MON MAR 24 2014
RADAR IMAGERY SHOWING SNOW DIMINISHING AT THE PRESENT BUT THERE
WILL BE ANOTHER ROUND OR TWO THIS MORNING BEFORE DIMINISHING
FURTHER. MVFR CIGS AND VSBYS WITH LOCAL IFR CIGS LIKELY ACROSS TAF
LOCATIONS THROUGH TODAY BEFORE GRADUAL IMPROVEMENT. LOWER CLOUDS
WERE FAIRLY TRANSIENT AND NOT EXPANDING SO THEY ARE NOT INCLUDED IN
TAFS. THOSE MAY NEED TO BE HANDLED WITH AMD/S IF THEY EXPAND...
THOUGH I AM NOT EXPECTING THAT.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MS MAR 14
SHORT TERM...FAB
LONG TERM...MS MAR 14
AVIATION...FAB
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1053 AM CDT MON MAR 24 2014
.UPDATE...
ISSUED AT 1041 AM CDT MON MAR 24 2014
CLOUDS/FLURRIES ARE SLIDING ACROSS THE SWRN/SRN CWA AT THIS TIME.
THIS IS ALONG THE NRN EDGE OF AN AREA OF HIGHER 85/70H LAPSE RATES.
ELSEWHERE ABUNDANT SUNSHINE IS OCCURRING WITH VERY DRY AIR IN PLACE
WITH PWATS NEAR OR BELOW A TENTH OF AN INCH. APPROACHING BAND OF
CIRRUS OVER ONTARIO IS ASSOCIATED WITH A MID LVL TROF. A CORRELATING
SFC COLD FRONT IS WELL DEFINED IN THE 925 THETAE FIELDS ACROSS
CTRL ONTARIO INTO SASK. ONLY MINOR TEAKS MADE TO NDFD/ZFP TODAY AS
COLD FRONT MOVES INTO NRN CWA LATER THIS AFTN. GUSTY WINDS SHOULD
INCREASE AS NWRLY FLOW DEEPENS WITH MID LVL TROF PASSAGE. PRECIP
COVERAGE STILL LOOKS LIMITED INITIALLY DUE TO VERY DRY AIR HOWEVER
LATEST SNSQ PARAMETER TRENDS SUGGEST HIGHER PROB DEVELOPS FROM 21Z
OVER NRN MN ZONES TO SERN WISC ZONES BY 03Z.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY AFTERNOON)
ISSUED AT 345 AM CDT MON MAR 24 2014
MAIN CONCERNS IN THE SHORT TERM ARE CENTERED AROUND THE CHANCE FOR
SNOW SHOWERS ACROSS MOST OF THE NORTHLAND THIS AFTERNOON...WITH
LINGERING LIGHT SNOW POSSIBLE TONIGHT THROUGH TUESDAY AFTERNOON.
ATTENTION WAS ALSO ASSIGNED TO THE PERSISTENT COLD TEMPERATURES
AND BREEZY NW WINDS.
WEAK HIGH PRESSURE AT THE SFC CONTINUES TO INFLUENCE THE UPPER
MIDWEST THIS MORNING WITH THE RIDGE AXIS EXTENDING FROM THE CENTER
OF THE HIGH OVER ERN IA THROUGH MN INTO WRN NORTH DAKOTA. COLD NWLY
FLOW ALOFT REMAINS IN PLACE AND WILL HELP TRIGGER SNOW SHOWERS
OVER THE REGION THIS AFTERNOON. AN EMBEDDED S/W OVER THE DAKOTAS
THIS MORNING...WITH AN ASSOCIATED SFC INVERTED TROUGH AROUND SIOUX
CITY WILL MOVE E/SEWD TODAY. A SECOND FEATURE TO THE NORTH ALONG A
COLD FRONT WILL MOVE SWD INTO THE AREA TODAY AS WELL. THE
COMBINATION OF THESE TWO WAVES AND STEEPENING LOW LEVEL LAPSE
RATES WILL GENERATE SNOW SHOWERS ACROSS THE REGION. AMTS WILL
LIKELY NOT ADD UP TO MUCH...BUT SNOW SQUALL PARAMETER FROM THE
LATEST RUNS OF THE NAM AND RAP ARE BOTH AT LEVELS THIS AFTERNOON
THAT WOULD INDICATE POSSIBLE PERIODIC BURSTS OF MDT TO HVY SNOW.
LATEST RAP13 IS ALSO POINTING TOWARD AN AREA TO THE SOUTH ACROSS
CENTRAL MN AND NW WI WHERE STRONG UVV IN THE DGZ COULD ALSO LEAD
TO BRIEF LOCALIZED HVY SNOW WITH REDUCED VSBYS. THE COLD/DRY AIR
MASS WILL LIKELY INHIBIT ANY ACCUMULATION OVER AN INCH...AND KEEP
THE SNOW GENERALLY IN THE FORM OF LARGE DENDRITES.
THE COLD FRONT DROPPING IN FROM THE NORTH WILL ALSO TRIGGER SNOW
SHOWERS ACROSS THE NRN COUNTIES LATER THIS AFTERNOON AND ALLOW
LIGHT SNOW/FLURRIES TO LINGER OVER THE REGION INTO TUESDAY. HIGH
PRESSURE WILL BUILD IN FROM THE W/NW ON TUESDAY AND HELP LIMIT THE
COVERAGE OF SNOW SHOWERS...BUT SHOULD STILL HAVE ENOUGH CAA
OCCURRING THROUGH THE DAY TO WARRANT LOW CHC POPS.
AS THE HIGH PRESSURE BUILDS IN OVER THE NRN ROCKIES AND FRONT
RANGE IN ERN MONTANA TODAY A TIGHT SFC PRES GRADIENT WILL FORM
OVER THE NRN PLAINS AND UPPER MIDWEST. STEEP LOW LVL LAPSE RATES
WILL ALSO HELP MIX DOWN STRONGER WINDS ALOFT. EXPECT NW WINDS
SUSTAINED AROUND 15 MPH...AND GUSTS TO 25 MPH TODAY. WINDS REMAIN
BREEZY TONIGHT AND INCREASE AGAIN ON TUESDAY...SIMILAR TO TODAY.
AIR MASS TODAY WILL NOT BE AS COLD AS YESTERDAY...SO TEMPS WILL BE
ROUGHLY 5 DEG WARMER. THE ADDED CLOUD COVER TONIGHT WILL KEEP
TEMPS FROM FALLING TOO FAR BELOW ZERO. HOWEVER ON TUESDAY ANOTHER
SURGE OF ARCTIC AIR FROM THE NORTH WILL KEEP HIGHS IN THE
TEENS...A GOOD 15 TO 20 DEG BELOW AVERAGE.
.LONG TERM...(TUESDAY EVENING THROUGH SUNDAY)
ISSUED AT 345 AM CDT MON MAR 24 2014
THIS PERIOD WILL BE ACTIVE...WITH A SIGNIFICANT STORM POSSIBLE LATE
WEDNESDAY NIGHT INTO THURSDAY NIGHT.
THE PERIOD WILL START OUT RATHER QUIET WITH THE NORTHLAND BETWEEN
HIGH PRESSURE TO THE EAST AND A LOW TO THE WEST. IT WILL BE DRY AND
COLD TUESDAY NIGHT WITH LOW AROUND OR IN THE SINGLE DIGITS BELOW
ZERO.
INCREASING WAA AND A SHORTWAVE WILL LEAD TO A CHANCE FOR LIGHT SNOW
WEDNESDAY...WITH CHANCES GREATEST ACROSS FAR NORTHERN MINNESOTA.
LIGHT SNOW ACCUMULATIONS ARE EXPECTED WEDNESDAY...AND THE NORTH
SHORE COULD GET SEE SOME HIGHER AMOUNTS DUE TO ONSHORE FLOW WITH
COLD TEMPERATURES STILL IN PLACE.
DIFFERENCES AMONG THE MODELS START TO AMPLIFY WEDNESDAY NIGHT WITH
THE GFS/NAM FASTER MOVING A CENTRAL PLAINS LOW NORTHEAST. WE
FOLLOWED CLOSE TO THE SLOWER ECMWF WHICH HAS SUPPORT FROM THE GEM.
THE ECMWF DEVELOPS AN INVERTED TROUGH INTO NORTHEAST MINNESOTA FROM
THE LOW IN WESTERN KANSAS WEDNESDAY NIGHT...THEN THE SURFACE LOW
MOVES INTO IOWA ON THURSDAY AND TOWARD SOUTHERN LAKE MICHIGAN
THURSDAY NIGHT. SNOW SHOULD INCREASE IN COVERAGE AND INTENSITY LATE
WEDNESDAY NIGHT OVER THE EASTERN HALF OF THE NORTHLAND. THE ECMWF
DOES BRING SOME WARMER TEMPS INTO OUR SOUTHERN CWA WITH A MIX
POSSIBLE OVER SOUTHERN AREAS LATE WEDNESDAY NIGHT INTO THURSDAY.
TEMPS DO LOOK COOLER THAN PREVIOUS RUNS...AND WE HAVE A SNOW/SLEET
MIX GOING UNTIL THURSDAY AFTERNOON WHEN SOME RAIN COULD OCCUR FAR
SOUTH. WE INCREASED POPS QUITE A BIT WEDNESDAY NIGHT INTO THURSDAY
NIGHT OVER THE EASTERN HALF OF THE NORTHLAND. THE THREAT FOR
SIGNIFICANT SNOWFALL CONTINUES TO INCREASE OVER ABOUT THE EASTERN
HALF OF THE NORTHLAND. LOWERING STABILITY...INCREASING FGEN...AND
UPPER LEVEL DIVERGENCE FROM A COUPLED JET ARE ALL FORECAST OVER THE
NORTHLAND WEDNESDAY NIGHT INTO THURSDAY EVENING. MORE DETAILS WILL
BE ADDED AS WE PROGRESS THROUGH THE WEEK AND HOPEFULLY THE MODELS
WILL CONVERGE ON A SOLUTION.
THE LOW WILL MOVE OFF TO THE EAST FRIDAY...WITH SOME LIGHT SNOW
LINGERING OVER PORTIONS OF NORTHERN WISCONSIN. INCREASING WAA
SATURDAY INTO SUNDAY WILL BRING THE POTENTIAL FOR SOME LIGHT MIXED
PRECIPITATION. WE HAVE SOME LOW POPS OVER PORTIONS OF THE NORTHLAND.
THE ECMWF HAS BACKED OFF CONSIDERABLY ON ITS WARMING INTO NEXT
WEEKEND AND HAS A BAROCLINIC ZONE ACROSS THE REGION. TEMPERATURES
ARE FORECAST TO RISE FROM THE MID TWENTIES TO LOWER THIRTIES
WEDNESDAY TO THE UPPER THIRTIES TO MID FORTIES SUNDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 639 AM CDT MON MAR 24 2014
A COUPLE SHORTWAVES AND A COLD FRONT HAS LED TO SCATTERED TO
BROKEN CLOUDS FROM 2500-4500 FEET...WITH SOME SNOW SHOWERS DROPPING
THEM TO 1500 FEET TEMPORARILY. HEATING TODAY WILL LEAD TO MORE
CLOUD DEVELOPMENT AND SOME ADDITIONAL SNOW SHOWERS. WINDS WILL
BECOME GUSTY OUT OF THE WEST...THEN VEER TO NORTHWEST. CONFIDENCE
DECREASES TONIGHT IN HOW MUCH CLOUDS WILL REMAIN AS COLDER AIR
MOVES INTO THE REGION. WE THINK THERE WILL BE SCATTERED TO BROKEN
CLOUDS ONCE AGAIN WITH CEILINGS FROM 2000-3500 FEET.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 24 0 17 0 / 20 20 10 0
INL 19 -7 15 -5 / 30 20 20 0
BRD 27 2 20 -1 / 20 20 0 0
HYR 26 2 18 -8 / 30 20 20 0
ASX 26 4 17 -2 / 20 20 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...CANNON
SHORT TERM...BJT
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
639 AM CDT MON MAR 24 2014
.SHORT TERM...(TODAY THROUGH TUESDAY AFTERNOON)
ISSUED AT 345 AM CDT MON MAR 24 2014
MAIN CONCERNS IN THE SHORT TERM ARE CENTERED AROUND THE CHANCE FOR
SNOW SHOWERS ACROSS MOST OF THE NORTHLAND THIS AFTERNOON...WITH
LINGERING LIGHT SNOW POSSIBLE TONIGHT THROUGH TUESDAY AFTERNOON.
ATTENTION WAS ALSO ASSIGNED TO THE PERSISTENT COLD TEMPERATURES
AND BREEZY NW WINDS.
WEAK HIGH PRESSURE AT THE SFC CONTINUES TO INFLUENCE THE UPPER
MIDWEST THIS MORNING WITH THE RIDGE AXIS EXTENDING FROM THE CENTER
OF THE HIGH OVER ERN IA THROUGH MN INTO WRN NORTH DAKOTA. COLD NWLY
FLOW ALOFT REMAINS IN PLACE AND WILL HELP TRIGGER SNOW SHOWERS
OVER THE REGION THIS AFTERNOON. AN EMBEDDED S/W OVER THE DAKOTAS
THIS MORNING...WITH AN ASSOCIATED SFC INVERTED TROUGH AROUND SIOUX
CITY WILL MOVE E/SEWD TODAY. A SECOND FEATURE TO THE NORTH ALONG A
COLD FRONT WILL MOVE SWD INTO THE AREA TODAY AS WELL. THE
COMBINATION OF THESE TWO WAVES AND STEEPENING LOW LEVEL LAPSE
RATES WILL GENERATE SNOW SHOWERS ACROSS THE REGION. AMTS WILL
LIKELY NOT ADD UP TO MUCH...BUT SNOW SQUALL PARAMETER FROM THE
LATEST RUNS OF THE NAM AND RAP ARE BOTH AT LEVELS THIS AFTERNOON
THAT WOULD INDICATE POSSIBLE PERIODIC BURSTS OF MDT TO HVY SNOW.
LATEST RAP13 IS ALSO POINTING TOWARD AN AREA TO THE SOUTH ACROSS
CENTRAL MN AND NW WI WHERE STRONG UVV IN THE DGZ COULD ALSO LEAD
TO BRIEF LOCALIZED HVY SNOW WITH REDUCED VSBYS. THE COLD/DRY AIR
MASS WILL LIKELY INHIBIT ANY ACCUMULATION OVER AN INCH...AND KEEP
THE SNOW GENERALLY IN THE FORM OF LARGE DENDRITES.
THE COLD FRONT DROPPING IN FROM THE NORTH WILL ALSO TRIGGER SNOW
SHOWERS ACROSS THE NRN COUNTIES LATER THIS AFTERNOON AND ALLOW
LIGHT SNOW/FLURRIES TO LINGER OVER THE REGION INTO TUESDAY. HIGH
PRESSURE WILL BUILD IN FROM THE W/NW ON TUESDAY AND HELP LIMIT THE
COVERAGE OF SNOW SHOWERS...BUT SHOULD STILL HAVE ENOUGH CAA
OCCURRING THROUGH THE DAY TO WARRANT LOW CHC POPS.
AS THE HIGH PRESSURE BUILDS IN OVER THE NRN ROCKIES AND FRONT
RANGE IN ERN MONTANA TODAY A TIGHT SFC PRES GRADIENT WILL FORM
OVER THE NRN PLAINS AND UPPER MIDWEST. STEEP LOW LVL LAPSE RATES
WILL ALSO HELP MIX DOWN STRONGER WINDS ALOFT. EXPECT NW WINDS
SUSTAINED AROUND 15 MPH...AND GUSTS TO 25 MPH TODAY. WINDS REMAIN
BREEZY TONIGHT AND INCREASE AGAIN ON TUESDAY...SIMILAR TO TODAY.
AIR MASS TODAY WILL NOT BE AS COLD AS YESTERDAY...SO TEMPS WILL BE
ROUGHLY 5 DEG WARMER. THE ADDED CLOUD COVER TONIGHT WILL KEEP
TEMPS FROM FALLING TOO FAR BELOW ZERO. HOWEVER ON TUESDAY ANOTHER
SURGE OF ARCTIC AIR FROM THE NORTH WILL KEEP HIGHS IN THE
TEENS...A GOOD 15 TO 20 DEG BELOW AVERAGE.
.LONG TERM...(TUESDAY EVENING THROUGH SUNDAY)
ISSUED AT 345 AM CDT MON MAR 24 2014
THIS PERIOD WILL BE ACTIVE...WITH A SIGNIFICANT STORM POSSIBLE LATE
WEDNESDAY NIGHT INTO THURSDAY NIGHT.
THE PERIOD WILL START OUT RATHER QUIET WITH THE NORTHLAND BETWEEN
HIGH PRESSURE TO THE EAST AND A LOW TO THE WEST. IT WILL BE DRY AND
COLD TUESDAY NIGHT WITH LOW AROUND OR IN THE SINGLE DIGITS BELOW
ZERO.
INCREASING WAA AND A SHORTWAVE WILL LEAD TO A CHANCE FOR LIGHT SNOW
WEDNESDAY...WITH CHANCES GREATEST ACROSS FAR NORTHERN MINNESOTA.
LIGHT SNOW ACCUMULATIONS ARE EXPECTED WEDNESDAY...AND THE NORTH
SHORE COULD GET SEE SOME HIGHER AMOUNTS DUE TO ONSHORE FLOW WITH
COLD TEMPERATURES STILL IN PLACE.
DIFFERENCES AMONG THE MODELS START TO AMPLIFY WEDNESDAY NIGHT WITH
THE GFS/NAM FASTER MOVING A CENTRAL PLAINS LOW NORTHEAST. WE
FOLLOWED CLOSE TO THE SLOWER ECMWF WHICH HAS SUPPORT FROM THE GEM.
THE ECMWF DEVELOPS AN INVERTED TROUGH INTO NORTHEAST MINNESOTA FROM
THE LOW IN WESTERN KANSAS WEDNESDAY NIGHT...THEN THE SURFACE LOW
MOVES INTO IOWA ON THURSDAY AND TOWARD SOUTHERN LAKE MICHIGAN
THURSDAY NIGHT. SNOW SHOULD INCREASE IN COVERAGE AND INTENSITY LATE
WEDNESDAY NIGHT OVER THE EASTERN HALF OF THE NORTHLAND. THE ECMWF
DOES BRING SOME WARMER TEMPS INTO OUR SOUTHERN CWA WITH A MIX
POSSIBLE OVER SOUTHERN AREAS LATE WEDNESDAY NIGHT INTO THURSDAY.
TEMPS DO LOOK COOLER THAN PREVIOUS RUNS...AND WE HAVE A SNOW/SLEET
MIX GOING UNTIL THURSDAY AFTERNOON WHEN SOME RAIN COULD OCCUR FAR
SOUTH. WE INCREASED POPS QUITE A BIT WEDNESDAY NIGHT INTO THURSDAY
NIGHT OVER THE EASTERN HALF OF THE NORTHLAND. THE THREAT FOR
SIGNIFICANT SNOWFALL CONTINUES TO INCREASE OVER ABOUT THE EASTERN
HALF OF THE NORTHLAND. LOWERING STABILITY...INCREASING FGEN...AND
UPPER LEVEL DIVERGENCE FROM A COUPLED JET ARE ALL FORECAST OVER THE
NORTHLAND WEDNESDAY NIGHT INTO THURSDAY EVENING. MORE DETAILS WILL
BE ADDED AS WE PROGRESS THROUGH THE WEEK AND HOPEFULLY THE MODELS
WILL CONVERGE ON A SOLUTION.
THE LOW WILL MOVE OFF TO THE EAST FRIDAY...WITH SOME LIGHT SNOW
LINGERING OVER PORTIONS OF NORTHERN WISCONSIN. INCREASING WAA
SATURDAY INTO SUNDAY WILL BRING THE POTENTIAL FOR SOME LIGHT MIXED
PRECIPITATION. WE HAVE SOME LOW POPS OVER PORTIONS OF THE NORTHLAND.
THE ECMWF HAS BACKED OFF CONSIDERABLY ON ITS WARMING INTO NEXT
WEEKEND AND HAS A BAROCLINIC ZONE ACROSS THE REGION. TEMPERATURES
ARE FORECAST TO RISE FROM THE MID TWENTIES TO LOWER THIRTIES
WEDNESDAY TO THE UPPER THIRTIES TO MID FORTIES SUNDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 639 AM CDT MON MAR 24 2014
A COUPLE SHORTWAVES AND A COLD FRONT HAS LED TO SCATTERED TO
BROKEN CLOUDS FROM 2500-4500 FEET...WITH SOME SNOW SHOWERS DROPPING
THEM TO 1500 FEET TEMPORARILY. HEATING TODAY WILL LEAD TO MORE
CLOUD DEVELOPMENT AND SOME ADDITIONAL SNOW SHOWERS. WINDS WILL
BECOME GUSTY OUT OF THE WEST...THEN VEER TO NORTHWEST. CONFIDENCE
DECREASES TONIGHT IN HOW MUCH CLOUDS WILL REMAIN AS COLDER AIR
MOVES INTO THE REGION. WE THINK THERE WILL BE SCATTERED TO BROKEN
CLOUDS ONCE AGAIN WITH CEILINGS FROM 2000-3500 FEET.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 24 0 17 0 / 20 20 10 0
INL 19 -7 15 -5 / 30 20 20 0
BRD 27 2 20 -1 / 20 20 0 0
HYR 26 2 18 -8 / 30 20 20 0
ASX 26 4 17 -2 / 20 20 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...BJT
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1011 AM CDT MON MAR 24 2014
.UPDATE...QUICK LOOK AT THE NAM AND RUC INDICATE THAT APPRECIABLE
ISENTROPIC LIFT HAS DIMINISHED OVER THE SOUTH WITH ONLY THE CLOUD
DECK REMAINING...IT SHOULD BE DIMINISHING LATER AS WELL. HAVE...THEREFORE...
REMOVED POPS FROM SOUTHERN AREAS. HAD TO ALSO MAKE SOME DOWNWARD
ADJUSTMENTS TO DEWPOINTS AS SOMEWHAT DRIER AIR ADVECTING IN AS
INDICATED IN OBSERVATIONAL DATA./26/
&&
.AVIATION...VFR CONDITIONS WITH BREEZY NORTHEAST WINDS AT 5-10KTS
THROUGH THIS AFTERNOON BECOMING LIGHT OUT OF THE NORTHWEST TO NORTH
OVERNIGHT./15/
&&
.PREV DISCUSSION... /ISSUED 342 AM CDT MON MAR 24 2014/
...LATE SEASON FREEZE EXPECTED FOR A LARGE PORTION OF THE REGION
TUESDAY NIGHT...
SHORT TERM...TEMPS WILL BE THE MAIN FORECAST FOCUS THIS SHORT TERM
WITH A SUBSTANTIAL LATE SEASON FREEZE EVENT EXPECTED FOR TUE NIGHT.
FORECAST MODELS CONTINUE TO BE IN SOLID AGREEMENT ON THE PATTERN
EVOLUTION THROUGH MID WEEK. A COOLER THAN AVG AIRMASS IS NOW OVER
THE REGION AS THE MEAN TROUGH AXIS IS SITUATED OVER THE EASTERN
CONUS. A COLDER PUSH OF AIR WILL ARRIVE EARLY TUE AS A S/WV ROUNDS
THE BASE OF THE TROUGH AND HELPS DEVELOP A SIGNIFICANT COASTAL STORM
OVER THE NE US. THE COLDEST PERIOD WILL BE TUE NIGHT AS SFC HIGH
PRESSURE BECOMES POSITIONED JUST TO OUR N/NE. DECENT RADIATIONAL
COOLING CONDITIONS WILL SUPPORT MOST OF THE CWA TO SEE FREEZING OR
SUB FREEZING CONDITIONS. THE COLDEST AND LONGEST SUB FREEZING
READINGS WILL BE OVER THE NE HALF OF THE CWA SOME WITH LOWS 26-28
DEGREES AND SUB FREEZING TEMPS LASTING SOME 3-8 HRS. THESE SORT OF
CONDITIONS WILL BE QUITE DAMAGING TO TENDER VEGETATION AND VARIOUS
BUDDING PLANTS. THE CURRENT HWO/GRAPHICS SHOW THIS WELL AND NO
CHANGES ARE NEEDED.
AS FOR TODAY AND THE OTHER FORECAST PERIODS...MODELS DO SHOW SOME
WEAK ISENTROPIC LIFT AROUND THE 300K LAYER TODAY ACROSS THE
SOUTH...BUT THIS DOESN`T APPEAR DEEP ENOUGH TO SUPPORT MUCH IN THE
WAY OF PRECIP. BASED OFF VARIOUS GUIDANCE...HAVE TRENDED POPS DOWN
TO SLIGHT CHANCE (20%) FOR THE HWY 84 CORRIDOR. ONLY VERY LIGHT
ACTIVITY WOULD OCCUR IF ANY CAN DEVELOP AT ALL. TEMPS TODAY WILL BE
BELOW AVG AND RANGE BETWEEN 60-65 DEGREES. TEMPS WERE TWEAKED TO THE
WARMER NAM GUID. TEMPS TONIGHT ARE A BIT TRICKY. MOST OF THE MOS
GUIDANCE IS OFFERING MID/UPPER 30S. I FEEL MID 30S WILL BE TOUGH AS
THE AREA SHOULD SEE WINDS INCREASE A BIT WHILE THE REINFORCING
FRONT MOVES IN. DUE TO THIS...VALUES WERE TWEAKED UPWARD A FEW
DEGREES. LASTLY...WITH STRONG CAA IN PLACE TUE...FOLLOWED THE COOLER
EURO GUIDANCE WHICH MATCHED THE RAW MODEL OUTPUT BETTER. THERE WILL
ALSO BE SOME BREEZY CONDITIONS WITH GUSTS OF 20-30 MPH AS DEEP
MIXING OCCURS. /CME/
LONG TERM...WEDNESDAY THROUGH NEXT MONDAY
MAIN HIGHLIGHTS WILL BE ON THE LATE SEASON FREEZE AT THE VERY
BEGINNING OF THE PERIOD WEDNESDAY FOLLOWED BY RAIN AND THUNDERSTORM
CHANCES LATE THURSDAY INTO FRIDAY MORNING WITH A NEAR SEASONABLE
WEEKEND TEMP WISE WITH LOWER RAIN CHANCES.
A DANGEROUS LATE SEASON FREEZE EXPECTED WEDNESDAY MORNING WITH
WIDESPREAD FROST LINGERING THROUGH 8-9AM THAT WILL IMPACT SENSITIVE
VEGETATION ACROSS THE REGION WITH THE MOST EXTREME IMPACTS EXPECTED
IN THE GOLDEN TRIANGLE REGION. AMPLE SUN WEDNESDAY WILL ALLOW FOR A
DECENT WARM UP BUT TEMPS WILL STILL BE 5-10F DEGREES BELOW NORMAL.
AT THIS TIME... WEDNESDAY LOOKS TO BE THE COLDEST PERIOD THROUGH THE
LONG TERM PERIOD.
SYNOPTICLY, H7-H5 RIDGING WILL BREAKDOWN LATE WEDNESDAY AS SW FLOW
AND A LOW AMPLITUDE S/WV TROUGH MOVES ACROSS THE SRN PLAINS THAT
WILL WEAKEN FURTHER AS IT APPROACHES THE LOWER MS VALLEY WITH PWATS
STAYING UNDER ONE INCH THROUGH THURSDAY MORNING. COINCIDENTALLY, A
STRONGER PACIFIC TROUGH WILL SWING ACROSS THE MID WEST WITH STRONG
CYCLOGENESIS MOVING INTO THE GREAT LAKES THROUGH THURSDAY NIGHT.
WINDS WILL PICK UP THROUGH THE DAY THURSDAY FROM THE SOUTH AS
PRESSURE GRADIENT TIGHTENS AND PWATS INCREASE TOWARDS 1.5" BY LATE
THURSDAY NIGHT. AS INCREASED DIVERGENCE OCCURS OVER TOP STRONGLY
SHEARED WIND FIELDS AND MUCAPE VALUES NEARING 1000 J/KG WITH
SUPPORTIVE VT`S AND SHOWALTERS, TRENDS ARE INCREASING FOR SOME MORE
POTENT THUNDERSTORMS AT LEAST ALONG AND WEST OF I-55 THURS EVENING
AND NIGHT. WILL CONTINUE TO WATCH FOR NOW AND NOT INTRODUCE ANYTHING
IN HWO/GRAPHICS FOR THURS NIGHT. INCREASED POPS SUBSTANTIALLY FOR
THURS NIGHT INTO FRI MRNG PERIOD WITH RAIN TAPERING DOWN THROUGH THE
DAY FRIDAY AS WAVE EXITS EAST.
FOR THE WEEKEND, EC/GEM REMAIN MORE CONSOLIDATED AND IN MORE
AGREEMENT TOWARDS GEFS VS. THE OP GFS. HAVE LEANED TOWARD THE EC/GEM
CAMP WHICH ADVERTISES STRONGER TROUGHING AND THUS SLIGHTLY COOLER
CONDITIONS FOR THE WEEKEND WITH WEAK CAA WHILE KEEPING AREA DRIER AS
RIDGING BEGINS TO BUILD BACK IN SUNDAY INTO MONDAY.
FOR FORECAST ELEMENTS...ECX TEMPS WERE FAVORED OR AT LEAST WEIGHTED
HEAVILY TOWARDS THROUGH MUCH OF THE PERIOD WITH SIZABLE CUTS MADE
DURING THE WEEKEND BELOW THE WARM MEX GUIDANCE. LOWS FRIDAY WERE
BUMPED UP OVER HIGH MENGFS TEMPS TO BE INLINE WITH RAW DEWPOINTS.
/ALLEN/
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL. /CME/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 64 38 60 31 / 0 0 0 0
MERIDIAN 65 37 60 27 / 0 0 0 0
VICKSBURG 64 38 61 31 / 0 0 0 0
HATTIESBURG 65 42 64 32 / 9 4 0 0
NATCHEZ 62 40 62 33 / 4 1 0 0
GREENVILLE 60 37 56 30 / 0 0 0 0
GREENWOOD 62 36 56 27 / 0 0 0 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
611 AM CDT MON MAR 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 412 AM CDT MON MAR 24 2014
PER LATEST RADAR...AREA OF LIGHT SNOW OCCURRING THROUGH THE HEART OF
OUR CWA VERY EARLY THIS MORNING IS TRENDING TOWARD THE NORTH AND
EAST...AND PER LATEST RAP 13 ANALYSIS LOOKS TO BE ASSOCIATED WITH
FRONTOGENESIS LOCATED AROUND 800 MB. MODELS INDICATING THIS FRONTAL
FORCING TO SLIP TO THE EAST THROUGH THE MORNING HOURS...AND
ANTICIPATE THE OVERALL PRECIPITATION TREND TO FOLLOW SUIT WITH MOST
OF THE SNOW ENDING BY 15Z. VISIBILITIES WITH THE SNOW HAVE GENERALLY
BEEN REMAINING IN THE 2 TO 3 MILE RANGE...NOT ESPECIALLY HEAVY...SO
AM THINKING THAT ONLY A FEW TENTHS OF ADDITIONAL ACCUMULATION WILL
OCCUR WITH THE ACTIVITY...POSSIBLY UP TO AN INCH. AFTER THAT...DO
NOT THINK WE WILL SEE MUCH MORE ACTIVITY THROUGH THE REMAINDER OF
THE DAY...THOUGH HI RES MODELS INDICATE SOME POSSIBLE REDEVELOPMENT
IN OUR NORTH AND EAST DURING THE LATE AFTERNOON AND EARLY EVENING AS
ANOTHER SHORTWAVE/COLD FRONT DROP SOUTHWARD ACROSS THE AREA DURING
THAT TIME FRAME. WOULD BE SURPRISED THAT MUCH OF THIS WOULD ACTUALLY
ACCUMULATE...PROBABLY MORE IN THE FORM OF FLURRIES...THOUGH DID
INCLUDE SOME SLIGHT POPS OVER THAT AREA IN THE AFTERNOON AND
EVENING. TEMPERATURES WILL OF COURSE REMAIN BELOW NORMAL...WITH
HIGHS RUNNING MOSTLY IN THE 30S.
WILL SEE NORTHWESTERLY WINDS BEGIN TO INCREASE BY LATE AFTERNOON AND
REMAIN FAIRLY BREEZY THROUGH TONIGHT WITH THE COLD AIR ADVECTION
BEHIND THE FRONTAL PASSAGE. THIS WILL MODERATE TEMPERATURES SOMEWHAT
IN SPITE OF DECREASING CLOUDS...THOUGH STILL COLD WITH LOWS DROPPING
INTO THE TEENS OVERNIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 412 AM CDT MON MAR 24 2014
QUIET CONDITIONS CONTINUE THROUGH WEDNESDAY EVENING...WITH LOW LEVEL
TEMPERATURES GRADUALLY WARMING BACK TO ABOVE NORMAL LEVELS AHEAD OF
NEXT SYSTEM WHICH MOVES IN LATE WEDNESDAY NIGHT. SURFACE RIDGE MOVES
INTO WESTERN PARTS OF THE AREA TUESDAY...WITH MOSTLY SUNNY SKIES AND
DECREASING NORTHWEST WINDS THROUGH THE DAY. MINIMAL SNOWFALL EARLY
THIS MORNING EXPECTED TO HAVE LITTLE IMPACT BY TUESDAY...SO FAVORED
SLIGHTLY WARMER GUIDANCE NUMBERS FROM THE UPPER 20S IN SOUTHWEST MN
TO MID 30S THROUGH THE MISSOURI RIVER VALLEY. SHOULD SEE TEMPS DROP
OFF QUICKLY TUESDAY EVENING...THEN LEVEL OFF OR SLIGHTLY RECOVER IN
THE LATTER HALF OF THE NIGHT AS THE RIDGE AXIS SHIFTS EAST AND SOUTH
FLOW PICKS UP.
WEDNESDAY SHOULD BE ANOTHER MILD DAY...AS 925MB TEMPERATURES WARM
INTO THE 5-10C RANGE NORTHEAST...TO MID TEENS IN SOUTHWEST PARTS OF
THE CWA. AGAIN FAVORED WARMING A BIT MORE OVER PREVIOUS FORECAST...
WITH HIGHS FROM AROUND 50 ACROSS SOUTHWEST MN TO LOWER 60S IN THE
MISSOURI VALLEY. THIS FAIRLY CLOSE TO RAW MODEL CONSENSUS...WITH
NAM/GFS ON THE COOLER SIDE OF THE SPECTRUM...ECMWF NEAR THE MIDDLE
AND GEM THE WARMEST AMONG THE RAW MODEL NUMBERS.
MODELS CONTINUE TO SHOW WAVE MOVING ACROSS THE REGION WEDNESDAY NIGHT
INTO THURSDAY NIGHT...WITH GFS ON THE FAST SIDE BUT TRENDING TOWARD
SLOWER ECMWF/GEM TIMING. HAVE LEANED MORE TOWARD THIS SLOWER TIMING
FOR NOW...WHICH KEEPS MUCH OF THE AREA WARMER WEDNESDAY NIGHT WITH
PRECIP EXPECTED TO HOLD OFF UNTIL LATTER HALF OF THE NIGHT. THURSDAY
SHOULD BE THE WETTEST PERIOD FOR MOST AREAS...ESPECIALLY EAST WHERE
PRECIP HAS GREATER CHANCE OF LINGERING INTO THURSDAY NIGHT. PRECIP
TYPE WILL BE IN QUESTION...LARGELY DEPENDENT ON LOW LEVEL THERMAL
PROFILES WHICH ARE NOT ENTIRELY CLEAR CUT GIVEN DISCREPANCIES IN WAVE
TIMING. GENERALLY EXPECT MUCH OF THE AREA TO REMAIN LIQUID THROUGH
LATE WEDNESDAY NIGHT AND THURSDAY MORNING...WITH AREAS NORTHWEST OF
LAKE ANDES-MITCHELL-BROOKINGS MORE LIKELY TO SEE RAIN/SNOW MIX OR
TOTAL TRANSITION TO SNOW PRIOR TO 18Z THURSDAY. THREAT FOR SNOW WILL
EXPAND TO THE EAST AND SOUTH THROUGH THE AFTERNOON AS COLD ADVECTION
CONTINUES BEHIND THE DEPARTING COLD FRONT...THOUGH AMOUNTS CURRENTLY
EXPECTED TO REMAIN ON THE LIGHT SIDE AROUND AN INCH OR LESS OVER THE
WESTERN AND NORTHERN PARTS OF THE AREA.
WITH SLOWER TIMING...WILL CARRY CHANCE OF MAINLY LIGHT SNOW ALONG AND
EAST OF I-29 INTO THURSDAY NIGHT...FOLLOWED BY DRY AND INCREASINGLY
MILD CONDITIONS THROUGH NEXT WEEKEND AS MORE ZONAL FLOW PATTERN SETS
UP ACROSS THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 605 AM CDT MON MAR 24 2014
AREAS OF LIGHT SNOW WITH BRIEF REDUCED VISIBILITIES AND MVFR/IFR
CEILINGS WILL TAPER OFF THROUGH THE MORNING HOURS...WITH IMPROVING
CONDITIONS FOR THE AFTERNOON. SOME HI RES MODELS INDICATE LIGHT
SNOW REDEVELOPING THIS AFTERNOON AND EVENING...THOUGH WILL NOT BE
WIDESPREAD ENOUGH OR HEAVY ENOUGH TO INCLUDE IN THE TAFS. NORTHWESTERLY
WINDS WILL PICK UP DURING THE AFTERNOON AND GUST TO 25 KTS AT
TIMES. WINDS WILL DROP A BIT THIS EVENING...THOUGH REMAIN SOMEWHAT
BREEZY DURING THE OVERNIGHT HOURS.
&&
.FIRE WEATHER...
ISSUED AT 412 AM CDT MON MAR 24 2014
ABOVE NORMAL TEMPERATURES IN THE 50S AND LOWER 60S...ALONG WITH
INCREASING SOUTH WINDS WILL LEAD TO ELEVATED FIRE DANGER ACROSS PARTS
OF THE AREA ON WEDNESDAY. AT THIS TIME...MINIMUM HUMIDITY LEVELS ARE
EXPECTED TO HOLD IN 30-45 PERCENT RANGE IN AREAS WITH THE STRONGEST
WINDS...WHICH SHOULD LIMIT THREAT OF RED FLAG CONDITIONS. HOWEVER
WILL MONITOR THIS CLOSELY OVER THE NEXT COUPLE OF DAYS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JM
LONG TERM...JH
AVIATION...JM
FIRE WEATHER...JH
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1015 AM CDT MON MAR 24 2014
.UPDATE...
SEE DISCUSSION FOR MORNING UPDATE.
&&
.DISCUSSION...
LIGHT RAIN AND DRIZZLE HAVE STARTED TO COME TO AN END ACROSS THE
REGION THIS MORNING AS ISENTROPIC LIFT AND 850MB CONVERGENCE
CONTINUE TO WEAKEN. ANOTHER UPPER LEVEL DISTURBANCE IS FORECASTED
TO MOVE ACROSS THE WATERS THIS AFTERNOON WHICH COULD HELP THE RAIN
TO START BACK UP OVER THE WATERS. MOST OF THE AFTERNOON PRECIP
SHOULD STAY OVER THE GULF THOUGH. THE HRRR DEVELOPS THE PRECIP
OVER HARRIS COUNTY BUT IT APPEARS TO BE THE OUTLIER. ONLY MADE
MINOR TWEAKS TO GRIDS TO ACCOUNT FOR CURRENT TRENDS. NO UPDATE
REQUIRED AT THIS TIME. 23
&&
.PREV DISCUSSION... /ISSUED 439 AM CDT MON MAR 24 2014/
DISCUSSION...
SRN 1/3 OF THE REGION STILL ON THE NORTHERN PERIPHERY OF AN
ACTIVE WRLY FLOW AND MAY SEE SOME SCT LIGHT SHRA TODAY. BETTER
CHANCES SOUTH OF I-10 AND FURTHER OFFSHORE. REINFORCING HIGH PRES
MOVES IN OVERNIGHT AND SHOULD PROVIDE US WITH A NICE MOSTLY SUNNY
SPRING DAY ON TUE. THIS WILL BE SHORT LIVED HOWEVER.
TUE NIGHT-THURS EVENING LOOKS TO BE A PARTICULARLY ACTIVE WX
PERIOD. AS HIGH PRES MOVES OFF TO EAST...WINDS WILL QUICKLY VEER
BACK TO THE E THEN SE AND INCREASE IN SPEED. THIS WILL MAKE FOR
CHALLENGING CLEANUP EFFORTS THAT ARE ONGOING IN GALVESTON BAY &
GULF AS MARINE WX CONDITIONS WILL DETERIORATE. LONG FETCH OF GULF
MOISTURE SETS UP TO RETURN BACK INTO THE REGION DURING THE 2ND
HALF OF THE WORK WEEK.
TROF NOW SEEN ON W/V IMAGERY OFF THE CA COAST WILL MOVE ACROSS TX
WED AFTN/NIGHT. IN ADDITION TO TAPPING INTO TO THE INITIAL RETURN
OF INCOMING GULF MOISTURE THIS FEATURE WILL BRING ALONG SOME OF
ITS OWN. EXPECT A ROUND OF SHRA/TSRA TO DEVELOP OFF THE THE WEST
AND MOVE ACROSS SE TX THRU THE DAY & EVNG. PARAMETERS AREN`T
EXACTLY LINING UP PERFECTLY FOR GREAT CHANCES OF STRONG TO SEVERE
STORMS WITH WARM NOSE NOTED AROUND 6-9K FT, NEUTRAL JET STRUCTURE
AND LOW CHANCE OF SIGNIFICANT HEATING DUE TO CLOUDS. BUT STILL
WORTH KEEPING AN EYE ON THINGS THOUGH AS SOUNDINGS SHOW STEEP
LAPSE RATES FURTHER ALOFT AND STRONG 35-40KT LLVL WINDS CAN`T BE
IGNORED JUST YET.
ECMWF/GFS/NAM12 ALL PINGING A GOOD PART OF THE AREA WITH SOME
DECENT RAINS (BUT AT SLIGHTLY DIFFERENT TIME PERIODS) BETWEEN WED
NIGHT AND THURS AFTN. ALL 3 ARE IN ASSOCIATION WITH ARRIVAL OF A
DEEPER SLUG OF TROPICAL MOISTURE. NAM12 TRIGGER APPEARS TO KEY IN
UPON SPEED CONVERGENCE INTO A COASTAL TROF SITUATED JUST INLAND
WED NIGHT. GFS/ECMWF TRIGGER LOOKS TO BE AN EWD ADVANCING DRY LINE
THURS AFTN. NOT SURE WHICH ONE...IF ANY...TO GO WITH BUT WILL
CONTINUE HIGHER END CHC POPS THRU THE PERIOD. (FOR THOSE PLAYING
AT HOME...THE NAM12 & TX TECH WRF HAVE BEEN MODELS OF CHOICE
LATELY).
LEFT THE EXTENDED AS IS. IT`S BEEN GEARED TOWARD THE ECMWF SOLN
WHICH GOES WITH A WEAK FRONTAL PASSAGE FRI NIGHT. LOOKS LIKE
CANADIAN IS IN ITS CAMP AS WELL. 47
MARINE...
MODERATE/STRONG OFFSHORE FLOW WILL CONTINUE TO DECREASE TODAY AS THE
GRADIENT RELAXES BRIEFLY. HAVE KEPT SCEC/SCA FLAGS UP FOR THE COAST-
AL WATERS THROUGH MID MORNING GIVEN THE ONGOING TRENDS. THIS RESPITE
SHOULD COME TO AN END AS A REINFORCING COLD FRONT MOVES INTO THE RE-
GION TONIGHT. CAUTION FLAGS MAY NEEDED ONCE AGAIN TONIGHT/OVERNIGHT.
THESE MODERATE/STRONG WIND SPEEDS ARE EXPECTED TO PERSIST ON THROUGH
THE END OF THE WEEK...EVEN AS THE WIND DIRECTION BECOMES MORE S/SELY
LATE WEDS OR SO. THIS DEVELOPING PATTERN OF A FAIRLY DEEP AND STRONG
ONSHORE FETCH COULD PRODUCE SOME DECENT SWELLS/ELEVATED WAVE HEIGHTS
DURING THE LATTER PART OF THE WEEK. MODELS REMAIN A BIT IFFY ON PRO-
SPECTS OF ANOTHER FRONT LATE FRI/EARLY SAT...BUT HAVE KEPT FCST BENT
ON ECMWF FOR NOW. 41
AVIATION...
GENERALLY VFR CONDITIONS (WITH OVC MID/HIGH CLOUDS) NOTED ACROSS FOR
MOST OF SE TX THIS MORNING...SAVE FOR SRN MOST SITES WHERE MVFR CIGS
REMAIN IN PLACE. THE BULK OF THE PCPN HAS MOVED EAST OF THE AREA BUT
STILL NOTING SOME LIGHT RETURNS EMBEDDED IN THIS SUBTROPICAL FLOW A-
LOFT APPROACHING FROM THE W/SW. ATTM NOT SURE IF ANY OF THAT IS EVEN
REACHING THE GROUND SO WILL LIKELY KEEP THINGS HERE DRY WITH THE 12Z
PACKAGE. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 67 44 69 46 63 / 10 10 0 0 60
HOUSTON (IAH) 64 50 72 49 64 / 20 10 0 0 40
GALVESTON (GLS) 61 57 70 59 65 / 30 10 0 0 50
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH LATE TONIGHT FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...23
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
258 PM CDT MON MAR 24 2014
.DISCUSSION...
257 PM CDT
MAIN CHALLENGES FOR THIS EVENING/OVERNIGHT WILL BE FOCUSED ON A
NARROW CHANNEL OF PRECIP/SNOW THAT IS POISED TO ARRIVE JUST AFT 00Z
AND PROGRESSIVELY SLIDE EAST/SOUTHEAST ACROSS THE CWFA.
BROAD ANTI-CYCLONIC FLOW HAS SETUP SHOP ACROSS THE REGION
TODAY...AND NOT MOVED MUCH. THIS HAS RESULTED IN CONSIDERABLY LOWER
DEW POINTS LINGERING LONGER INTO THIS AFTERNOON. SFC TEMPS HAVE
STRUGGLED TO WARM BEYOND THE LOW 30S...MAINLY DUE TO THE POTENT
THERMAL TROUGH OVERHEAD.
UPSTREAM OF THE CWFA SFC OBS INDICATE BETTER MOISTURE IN THE
ATMOSPHERE WITH T/TD SPREAD GENERALLY LESS THAN 10 DEG...AND VISIBLE
IMAGERY SHOWING SOME LIFT TO THE CLOUDS ALONG THE FRONTAL BOUNDARY
FROM NORTHWEST IOWA STRETCHING NORTHEAST THROUGH WESTCENTRAL WISC.
FORECAST GUIDANCE HAS CONTINUED TO INDICATE THE FORCING ALONG THE
BOUNDARY WILL BECOME THE FOCAL POINT FOR THE PRECIP LATER THIS
EVENING. HI-RES GUIDANCE HAS BEEN RELATIVELY CONSISTENT WITH THIS
FEATURE...ARRIVING ACROSS THE NORTHWEST CWFA BTWN 00-03Z AND
STEADILY PROGRESSING SOUTHEAST ACROSS THE CWFA. THE WARM AIR
ADVECTION INTO THIS BAND DOES APPEAR TO BE MINIMAL...ALTHOUGH STILL
COULD BE STRONG ENOUGH TO SUPPORT A QUICK BURST OF SNOWFALL AS IT
ARRIVES ACROSS THE CWFA TONIGHT. LOCAL WRF-ARW INDICATES SNOWFALL
RATES COULD APPROACH 1"/HR AT THE PEAK BETWEEN 04-07Z...AND HAS BEEN
CONSISTENT WITH EARLIER CYCLES. HAVE ADJUSTED SNOWFALL UP JUST A
LITTLE TO GENERALLY 1"...HOWEVER ALONG AND WEST OF LASALLE TO
CRYSTAL LAKE SNOWFALL TOTALS COULD BE SLIGHTLY HIGHER AS THE SNOW
BAND SHOULD BE ARRIVING WITH SLIGHTLY BETTER FORCING/INSTABILITY AND
COULD SEE BETWEEN 1-2". TEMPS OVERNIGHT WITH INCREASING CLOUD COVER
WILL NOT COOL MUCH FROM THE PRESENT STATUS...SO HAVE LOWS IN THE
LOW/MID 20S.
CONFIDENCE...HIGH.
CONFIDENCE IN SNOWFALL TOTALS...MEDIUM/HIGH.
TUESDAY THROUGH WEDNESDAY...
STRONG COLD AIR ADVECTION ARRIVES TUE...AND UNFORTUNATELY MOTHER
NATURE DECIDES ANOTHER COLD/BLUSTERY DAY WOULD BE A GREAT IDEA.
BROAD SFC RIDGE SLIDES SOUTHEAST FROM CENTRAL CANADA INTO THE
CENTRAL PLAINS...WITH A TIGHT GRADIENT ALONG THE LEE-SIDE. THIS
POINTS TOWARDS BREEZY CONDITIONS FOR TUE...WITH TEMPS STRUGGLING TO
WARM MUCH FROM THE OVERNIGHT LOWS. AT THIS TIME HAVE HIGHS IN THE
MID 20S FOR MUCH OF THE CWFA...WITH THE SOUTHERN PORTIONS POSSIBLY
REACHING 30 DEG TUE AFTN. OTHERWISE SKIES WILL BECOME P-CLOUDY AS
THE PUNCH OF COLD/DRY AIR ARRIVES.
THE ATMOSPHERE REMAINS PROGRESSIVE WITH THE SFC RIDGE QUICKLY
PUSHING EAST AND BECOMING CENTERED OVER THE FORECAST AREA TUE NGT
AND BRINGING LIGHTER WINDS. UNFORTUNATELY WITH MINIMAL CLOUD COVER
EXPECTED TUE NGT...LOWS WILL RADIATE INTO THE SINGLE DIGITS TO LOW
TEENS.
500MB TROUGH AXIS BEGINS TO PIVOT NORTHEAST AWAY FROM THE GREAT
LAKES REGION WED...WITH LLVL FLOW TURNING SOUTHWESTERLY AND BRINGING
SLIGHTLY WARMER AIR BACK INTO THE AREA FOR WED. TEMPS SHOULD REBOUND
INTO THE MID/UPR 30S WED...HOWEVER SKIES WILL BEGIN TO THICKEN LATE
WED NGT AS A ROBUST SYSTEM TAKES SHAPE ACROSS THE CENTRAL PLAINS AND
IS POISED TO BRING AMPLE AMOUNTS OF MOISTURE TO THE MID-MISSISSIPPI
VALLEY THUR.
CONFIDENCE...HIGH.
THURSDAY THROUGH FRIDAY...
FOCUS FOR THE THUR/FRI TIMEFRAME CONTINUES TO BE ON A PROGGED
SHORTWAVE WITH WILL HAVE AMPLE MOISTURE AS RETURN FLOW MOISTURE FROM
THE GULF WILL BE STREAMING INTO THIS SYSTEM AS IT DEVELOPS. IT
APPEARS AS THIS SYSTEM APPROACHES THE REGION THUR...SOME ELEVATED
INSTABILITY WILL BE PRESENT. AT THIS TIME HAVE OPTED TO HOLD OUT
MENTION OF THUNDER...BUT COULD SEE THE NEED TO ADD THIS INTO THE
PRESENT FORECAST FOR THUR.
TEMPS WILL BE MUCH WARMER FOR THUR/FRI...BUT STILL SUB-SEASONAL WITH
HIGHS IN THE MID/UPR 40S. WITH THE SEMI-ZONAL FLOW ALONG THE
NORTHERN STREAM...THE SHORTWAVE WILL LIKELY LIFT NORTHEAST AND
PROVIDE DRY WEATHER AT THE EARLIEST LATE THUR NGT...BUT LEANING MORE
TOWARDS FRI AFTN. GUIDANCE HAS DEMONSTRATED INCONSISTENCIES IN THE
TIMING OF DEPARTURE...SO THIS IS A LOW CONFIDENCE FOR THE END TIMING.
CONFIDENCE...MEDIUM.
SATURDAY THROUGH EARLY NEXT WEEK...
LONG WAVE PATTERN CONTINUES TO POINT TOWARDS WARMING TREND FOR THE
WEEKEND THROUGH EARLY NEXT WEEK. WITH A SEMI-ZONAL FLOW SAT
TRANSITIONING TO EASTERN CONUS RIDGING...TEMPS HAVE CONTINUED TO BE
FORECAST INTO THE 60S SUN/MON. SAT WILL BE THE COOLER DAY FOR THE
WEEKEND...WITH HIGHS GENERALLY IN THE UPR 40S/LOW 50S.
ENSEMBLES ARE INDICATING THAT A POTENT SYSTEM WILL BE PUSHING EAST
FROM THE PACIFIC INTO CENTRAL CALI SUN...AND A SHORTWAVE WILL
EJECTING FROM THE ROCKIES INTO THE SOUTHERN PLAINS EARLY MON. THIS
WILL BRING ANOTHER PERIOD OF ACTIVE AND POTENTIALLY STORMY WEATHER
TO THE REGION MON.
CONFIDENCE...MEDIUM/HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LAKE BREEZE AT MDW THIS AFTERNOON...POSSIBLE AT ORD.
* PERIOD OF LIGHT/MODERATE SNOW LATE EVENING/EARLY TUESDAY MORNING
WITH IFR/LIFR VIS/CIGS POSSIBLE.
* COLD FRONT AFTER MIDNIGHT SHIFTING WINDS NORTHWEST WITH GUSTS
25-30 KTS...CONTINUING THROUGH TUESDAY AFTERNOON. CMS
//DISCUSSION...UPDATED 18Z...
A RIDGE OF HIGH PRESSURE CURRENTLY OVER THE AREA WILL SHIFT EAST
THIS AFTERNOON. A LAKE BREEZE IS FORMING ALONG THE SHORE BUT
CONFIDENCE REGARDING HOW FAR INLAND IT MAY MOVE IS LOW. HAVE
MAINTAINED A SHIFT AT GYY BUT WILL NEED TO MONITOR TRENDS FOR
ORD/MDW. OTHERWISE...WEST/NORTHWEST WINDS UNDER 10KTS WILL TURN
MORE SOUTHWESTERLY LATER THIS AFTERNOON...AND PERHAPS SOUTHERLY
THIS EVENING BEFORE TURNING BACK SOUTHWEST AHEAD OF A COLD FRONT
LATER THIS EVENING.
AS THE COLD FRONT APPROACHES LATER THIS EVENING...A BAND OF LIGHT
TO MODERATE SNOW IS EXPECTED AHEAD OF IT. TOTAL DURATION MAY ONLY
BE A FEW HOURS BUT VIS/CIGS COULD QUICKLY DROP TO IFR OR PERHAPS
BRIEF LIFR. OPTED TO GO PREVAILING AND THERE COULD BE A PERIOD OF
LIGHT SNOW OR FLURRIES ON EITHER SIDE OF THIS TIME WINDOW...BUT IF
THE SNOW MATERIALIZES AS EXPECTED...CONDITIONS SHOULD DETERIORATE
QUICKLY. COLD FRONT THEN SHIFTS WINDS NORTHWEST WITH STRONG/GUSTY
NORTHWEST WINDS CONTINUING THROUGH TUESDAY AFTERNOON. CMS
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH LAKE BREEZE WILL REACH MDW...MEDIUM ON TIMING.
* LOW LAKE BREEZE WILL REACH ORD.
* HIGH FOR SNOW LATE THIS EVENING...MEDIUM FOR TIMING/VIS/CIGS.
* HIGH FOR WINDS OVERNIGHT/TUESDAY MORNING. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR.
WEDNESDAY...VFR. CHC RA LATE WED NGT.
THURSDAY...RA LIKELY. MVFR/IFR POSSIBLE.
FRIDAY...CHC RA/SN MAINLY EARLY. MVFR POSSIBLE.
SATURDAY AND SUNDAY...VFR.
RATZER
&&
.MARINE...
201 PM CDT
HIGH PRESSURE WILL BE SHIFTING TO THE EAST THIS EVENING AS A COLD
FRONT APPROACHES FROM THE NORTHWEST. THE FRONT WILL CROSS THE LAKE
TONIGHT TURNING WINDS TO THE NORTHWEST AS HIGH PRESSURE BUILDS INTO
THE PLAINS. THE PRESSURE GRADIENT WILL SUPPORT WINDS GUSTING TO 30
KT ACROSS THE SOUTHERN PART OF THE LAKE WITH MID 20S GUSTS EXPECTED
NORTH WHICH WILL LIKELY CONTINUE THROUGH MUCH OF TUESDAY. THE PLAINS
HIGH WILL MOVE ACROSS THE REGION WITH THE RIDGE AXIS PASSING OVER
THE LAKE TUESDAY NIGHT AND WEDNESDAY MORNING. THIS WILL ALLOW WINDS
TO DIMINISH TUESDAY EVENING AND THEN TURN SOUTHERLY THROUGH THE DAY
WEDNESDAY. SPEEDS WILL ALSO INCREASE WEDNESDAY AS LOW PRESSURE
DEVELOPS ACROSS THE CENTRAL PLAINS AND TRACKS EAST THEN NORTHEAST
ACROSS LAKE MICHIGAN THURSDAY AND FRIDAY. STILL NEED TO IRON OUT THE
SPEED OF THE LOW WHICH WILL AFFECT WHICH PERIODS ARE AFFECTED BY
STRENGTHENING WINDS. WARMER AIR WILL BE MOVING IN AHEAD OF THIS
SYSTEM WHICH MAY MITIGATE THE MAXIMUM WIND POTENTIAL...ESPECIALLY
SOUTH THANKS TO AN INVERSION. 30 KTS LOOKS EASILY ATTAINABLE AT THIS
POINT BUT WILL NEED TO WATCH GALE POTENTIAL CLOSELY BUT IT IS
POSSIBLE THAT THE INVERSION MAY KEEP GALES FROM OCCURRING. WINDS
SHIFT WEST AND NORTHWEST AS THE LOW PASSES SOME TIME THURSDAY NIGHT
OR FRIDAY THEN EASE INTO SATURDAY AS ANOTHER AREA OF HIGH PRESSURE
MOVES INTO THE REGION.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...1 AM TUESDAY TO 10
PM TUESDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...4 AM TUESDAY TO 4
AM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
National Weather Service Lincoln IL
250 PM CDT Mon Mar 24 2014
.DISCUSSION...
ISSUED 251 PM CDT Mon Mar 24 2014
Two main concerns with this forecast package. First one involves
chances of snow tonight across the area. The second concern
involves the next weather system moving through the area Wed night
and continuing through Friday. Models are in fairly good agreement
with the first system tonight, with most of the pcpn now holding
off til after 10pm tonight, and then being mostly done by 7am
tomorrow. With the second system, models continue with same
differences as yesterday. GFS and NAM-WRF are quicker than the
ECMWF and GEM, however the GFS continues to have a second low
pressure area riding up into the Ohio valley after the main push
of the front and pcpn. So, in the extended, will follow the speed
of the NAM/GFS, and agree with the ending like the ECMWF and GEM.
SHORT TERM...Tonight through Thursday Night
Weak frontal boundary is still west of the area out in western
Iowa. Light snow is falling in some locations, though not very
wide spread at this time. This area of snow will move into
Illinois later this evening and will have to overcome the dry
airmass that is in place. Based on radar trends, best snow will be
occurring in MO and south of the state. By 1am, snow should have
begun in northwest areas of the cwa, mainly along and northwest of
I-55. By morning, snow will have spread east across the remainder
of the cwa and ended in the west. Because of the weak dynamics and
minimal moisture, believe snowfall amounts will be very light. So
expecting only about 1/2 inch or less tonight across the area,
with highest amounts being along and north of I-74. With the 500mb
trough rotating through the area tomorrow morning, flurries will
still be possible over the area. By afternoon, the pcpn will have
ended and skies will become partly to mostly sunny. Then dry
weather is expected Tue night and Wed. However, by Wed evening, the
beginnings of the next weather system will begin moving into the
southwest parts of of the area. The warm air advection pcpn will
overspread the rest of the area after midnight Wed night. The pcpn
will continue and increase some during the day Thursday as a cold
front begins to push into the area for Thur afternoon and Thur
night. The airmass ahead of the system will be warm and moist, and
combined with the strong southerly winds, should be the right
dynamics for thunderstorms to be possible too. So have chance of
thunderstorms mentioned with the likely showers for Thur and Thur
night.
Temps will remain well below normal for first 3 periods, but then
begin to warm for remainder of the period. However, temps will
only get to around normal by Thursday.
LONG TERM...Friday through Monday
Once the front passes through the area Thur night, showers will
continue for a brief period behind the front. Then dry weather
will be the rule as high pressure builds into the region for Sat
through Sunday night. With the pattern being somewhat zonal
through the weekend, another weather system becomes possible for
Monday. Both GFS and ECMWF have something there for the day, so
will have chance pops for now for Monday.
Warmer temps are to be expected through the period, hopefully
signaling an end to the the colder than normal temps. Temps are
expected to actually rise to above normal for Sunday and Monday.
Auten/Geelhart
&&
.AVIATION...
ISSUED 1223 PM CDT Mon Mar 24 2014
Ceilings expected to gradually lower this evening as a cold front
approaches from the northwest. Lots of dry air needed to be
overcome initially, but a 3-5 hour period of MVFR ceilings/
visibilities expected as light snow accompanies the passage of the
front. Based on the RAP model, have indicated a couple hours with
TEMPO groups on when the lowest visibilities are most likely in
the heavier bands of snow. Once the front clears, a brief period
of mostly clear skies expected until ceilings around 4000 feet
redevelop by mid-morning. Surface gusts over 20 knots likely to
develop late Tuesday morning.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1251 PM CDT MON MAR 24 2014
.DISCUSSION...
339 AM CDT
WE`LL HAVE TO DEAL WITH WINTER FOR A FEW MORE DAYS...BUT SUPPORT IS
GROWING LATER IN THE EXTENDED PERIOD AND BEYOND FOR A PATTERN CHANGE
THAT WILL YIELD AT LEAST A FEW DAYS OF WARM...ABOVE NORMAL
TEMPERATURES. SO HANG TIGHT IF YOU ARE WEARISOME OF THE COLD WEATHER.
PRIMARY FORECAST CONCERNS ARE WITH SNOW CHANCES MAINLY TONIGHT AND
WITH TEMPERATURES DURING ANOTHER BLAST OF EXTREMELY COLD AIR FOR
THIS TIME OF YEAR ON TUESDAY/TUESDAY NIGHT.
TODAY...
MORNING W/V IMAGERY SHOWS LEAD SHORTWAVE APPROACHING FROM NORTHERN
PLAINS. DUE TO VERY DRY LOW AND MID LEVELS NOTED ON PROXIMITY AND
UPSTREAM 00Z RAOBS...ONLY ANTICIPATING THAT THIS INITIAL WAVE WILL
RESULT IN INCREASING MID AND HIGH CLOUDS THEN LOWERING OF CLOUD
BASES. GIVEN FORCING FROM WAVE...CANT COMPLETELY RULE OUT FLURRIES
FROM OVC DECK IN AFTERNOON...BUT HAVE ADJUSTED FORECAST TO GO
PRIMARILY DRY FOR DAYTIME HOURS. HAVE SLIGHT POPS IN FAR NORTHWEST
LATE AFTERNOON IN ADVANCE OF NEXT UPPER TROUGH THAT WILL PROVIDE
FORCING FOR PERIOD OF LIGHT SNOW TONIGHT. MINOR WARM ADVECTION SHOULD
SUPPORT HIGHS IN THE MID 30S ACROSS THE CWA DESPITE THE CLOUDS.
TONIGHT...
AFOREMENTIONED UPPER TROUGH AND ARCTIC FRONT APPROACH EXPECTED TO
PROVIDE ENOUGH SUPPORT FOR A PERIOD OF LIGHT SNOW/PROGRESSIVE BAND
OF LIGHT SNOW MOVING SOUTHEAST ACROSS THE CWA FROM EARLY EVE IN NW
AND LIKELY EXITING SOUTHEAST CWA BY OR SHORTLY AFTER DAYBREAK
TUESDAY. CONTINUED TREND OF HIGH POP/LOW QPF...WITH CATEGORICAL
POPS IN SNOW BAND. HAVE GOOD CONFIDENCE THAT IT WILL SNOW BUT
DURATION COULD LIMIT ACCUMULATIONS TO AT MOST A HALF INCH TO MAYBE
AN INCH IN SOME SPOTS. SOME LOCATIONS MAY SEE ONLY A DUSTING.
GUIDANCE SEEMS TO MAXIMIZE FORCING SOUTHEAST OF I-55...SO HAVE
AMOUNTS CLOSEST TO AN INCH THERE. LOWS WILL RANGE BETWEEN 20 AND
25 DEGREES...SO SNOW WILL BE POWDERY IN NATURE.
TUESDAY AND TUESDAY NIGHT...
THE AIR MASS PLUNGING SOUTH IN DEEP UPPER TROUGH WILL BE AS COLD AS
IT GETS THIS TIME OF YEAR AT -16 TO -19C AT 850 MB...SO TEMPERATURE
RECOVERY WILL BE SLOW AND MINIMAL THROUGH AFTERNOON. ONLY EXPECTING
UPPER 20S TO AROUND 30 NORTH OF I-80 AND AROUND 30/LOW 30S SOUTH OF
I-80. ANOTHER UPPER TROUGH PASSAGE DURING THE MORNING COULD TOUCH
OFF SOME SPOTTY LIGHT SNOW OR FLURRIES. LAKE EFFECT PARAMETERS WILL
BE EXCELLENT...BUT NW BOUNDARY LAYER FLOW WILL KEEP FOCUS PRIMARILY
EAST OF PORTER COUNTY INDIANA. ARCTIC HIGH WILL THEN BE OVERHEAD
TUESDAY NIGHT...WITH GOING FORECAST OF LOW-MID TEENS BY DAYBREAK
WEDS IN GOOD SHAPE.
WEDNESDAY AND WEDNESDAY NIGHT...
AN UPPER TROUGH WILL ENTER THE SOUTHWEST US...WITH EXTREMELY DEEP
CYCLONE OFF EAST COAST. THIS WILL FORCE RAPID AMPLIFICATION OF
HEIGHT FIELDS...WITH RAPID HEIGHT RISES AND WARM ADVECTION AFTER
VERY COLD START TO DAY. CLOUDS WILL INCREASE IN AFTERNOON BUT
TEMPERATURES LIKELY TO RECOVER TO AT LEAST THE UPPER 30S TO LOWER
40S. WILL NEED TO WATCH FOR LIGHT PRECIP DUE TO ISENTROPIC ASCENT
OVER NORTHERN CWA DURING EVENING AT A TIME WHEN THERMAL PROFILES
WILL BE MARGINAL FOR POSSIBLE WINTER MIX. HAVE TRENDED FORECAST DRY
DURING THIS PERIOD FOR NOW HOWEVER. THEN OVERNIGHT...LOW LEVEL JET
AND MOISTURE TRANSPORT WILL INCREASE...WITH ADDITIONAL FORCING FROM
LEAD SHORTWAVE APPROACHING FROM SOUTHWEST. HAVE INCREASED POPS TO
THE LOW CHANCE RANGE AND SHOULD PRECIP OCCUR...PROFILES WILL BE WARM
ENOUGH FOR RAIN.
THURSDAY THROUGH FRIDAY NIGHT...
DEEP SURFACE LOW OVER SOUTHERN PLAINS WILL APPROACH DURING THIS
TIMEFRAME...WITH INFLUX OF HIGHER PWAT AIR AND ENHANCED LLJ FAVORING
PERIODS OF RAIN SHOWERS MUCH OF THURSDAY AND THURSDAY NIGHT...WITH
LIKELY POPS DURING THIS PERIOD. DECENT MIDLEVEL LAPSE RATES ABOVE
CAPPING INVERSION MAY BE MARGINALLY SUPPORTIVE OF THUNDER CHANCES IN
SOUTHERN CWA ON THURS...BUT HAVE NOT INCLUDED THUNDER YET. GUIDANCE
CONTINUES TO DIFFER ON TIMING OF SYSTEM AND COLD FRONT CLEARING THE
CWA...WITH 00Z ECMWF CONTINUING TO BE ON SLOWER SIDE OF GUIDANCE. IF
SLOW TREND WINS OUT...THERE COULD BE ENOUGH COLD AIR AROUND IN
AFTERNOON TO ENABLE MIX WITH SNOW IN PARTS OF NORTHERN CWA. THEN
HAVE SLIGHT POPS FRIDAY NIGHT FOR POSSIBLE FAST MOVING SHORT WAVE.
SATURDAY AND SUNDAY...
SATURDAY WILL BE TRANSITION DAY HERALDING PATTERN CHANGE TO MUCH
WARMER ON SUNDAY AS UPPER RIDGING BUILDS ACROSS CENTRAL CONUS. WE
WILL BE NORTH OF WARM FRONT ON SATURDAY...WITH ONSHORE FLOW KEEPING
LAKESHORE CHILLY AND GENERALLY UPPER 40S TO AROUND 50 INLAND. THE
WARM FRONT WILL LIFT NORTH SATURDAY NIGHT AND CONTINUED STRONG WARM
ADVECTION ALOFT WITH +8 TO +10C AT 850 MB AND 11-12C AT 925
SUPPORTING HIGHS AT LEAST IN LOW-MID 60S. IF MIXING IS DEEP ENOUGH
AND CLOSE TO 850 MB...SOME PARTS OF CWA MIGHT FLIRT WITH 70 DEGREES!
A PEAK INTO NEXT INDICATES POTENTIAL FOR EVEN WARMER TEMPERATURES ON
MONDAY. THUS THE WARM WEATHER MANY PEOPLE HAVE BEEN WAITING FOR
LOOKS LIKE ITS FINALLY ON ITS WAY.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* POSSIBLE LAKE BREEZE THIS AFTERNOON.
* PERIOD OF LIGHT/MODERATE SNOW LATE EVENING/EARLY TUESDAY MORNING
WITH IFR/LIFR VIS/CIGS POSSIBLE.
* COLD FRONT AFTER MIDNIGHT SHIFTING WINDS NORTHWEST WITH GUSTS
25-30 KTS...CONTINUING THROUGH TUESDAY AFTERNOON. CMS
//DISCUSSION...UPDATED 18Z...
A RIDGE OF HIGH PRESSURE CURRENTLY OVER THE AREA WILL SHIFT EAST
THIS AFTERNOON. A LAKE BREEZE IS FORMING ALONG THE SHORE BUT
CONFIDENCE REGARDING HOW FAR INLAND IT MAY MOVE IS LOW. HAVE
MAINTAINED A SHIFT AT GYY BUT WILL NEED TO MONITOR TRENDS FOR
ORD/MDW. OTHERWISE...WEST/NORTHWEST WINDS UNDER 10KTS WILL TURN
MORE SOUTHWESTERLY LATER THIS AFTERNOON...AND PERHAPS SOUTHERLY
THIS EVENING BEFORE TURNING BACK SOUTHWEST AHEAD OF A COLD FRONT
LATER THIS EVENING.
AS THE COLD FRONT APPROACHES LATER THIS EVENING...A BAND OF LIGHT
TO MODERATE SNOW IS EXPECTED AHEAD OF IT. TOTAL DURATION MAY ONLY
BE A FEW HOURS BUT VIS/CIGS COULD QUICKLY DROP TO IFR OR PERHAPS
BRIEF LIFR. OPTED TO GO PREVAILING AND THERE COULD BE A PERIOD OF
LIGHT SNOW OR FLURRIES ON EITHER SIDE OF THIS TIME WINDOW...BUT IF
THE SNOW MATERIALIZES AS EXPECTED...CONDITIONS SHOULD DETERIORATE
QUICKLY. COLD FRONT THEN SHIFTS WINDS NORTHWEST WITH STRONG/GUSTY
NORTHWEST WINDS CONTINUING THROUGH TUESDAY AFTERNOON. CMS
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* LOW LAKE BREEZE WILL REACH ORD/MDW.
* HIGH FOR SNOW LATE THIS EVENING...MEDIUM FOR TIMING/VIS/CIGS.
* HIGH FOR WINDS OVERNIGHT/TUESDAY MORNING. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR.
WEDNESDAY...VFR. CHC RA LATE WED NGT.
THURSDAY...RA LIKELY. MVFR/IFR POSSIBLE.
FRIDAY...CHC RA/SN MAINLY EARLY. MVFR POSSIBLE.
SATURDAY AND SUNDAY...VFR.
RATZER
&&
.MARINE...
255 AM CDT
MARINE CONCERNS INVOLVE A PROGRESSIVE PATTERN OF TROUGHS AND
RIDGES THROUGH THE COMING WEEK...WHICH WILL PRODUCE A FEW PERIODS
OF GUSTY NORTHERLY AND SOUTHERLY WINDS.
HIGH PRESSURE WAS DRIFTING ACROSS THE MIDWEST EARLY THIS MORNING
AND WILL CONTINUE EAST TO THE MID-ATLANTIC REGION BY THIS EVENING.
A COLD FRONT WILL APPROACH FROM THE WEST THIS EVENING...ALLOWING
WINDS TO BACK TO THE SOUTH THIS AFTERNOON BEFORE VEERING NORTHWEST
AFTER MIDNIGHT TONIGHT AND INCREASING INTO THE 20-30 KT RANGE
BEHIND THE COLD FRONT BY EARLY TUESDAY. GUSTY NORTHWEST
WINDS WILL ONLY GRADUALLY DIMINISH BY LATE TUESDAY...BEFORE
FALLING OFF MORE QUICKLY AND BACKING WEST TUESDAY NIGHT AS HIGH
PRESSURE RIDGING MOVES TOWARD THE WESTERN LAKES BY WEDNESDAY
MORNING.
THE RIDGE WILL MOVE QUICKLY EAST OF THE AREA WEDNESDAY
AFTERNOON...WHILE LOW PRESSURE DEVELOPS OVER THE HIGH PLAINS AND
SOUTHERLY WINDS DEVELOP ACROSS THE MISSISSIPPI VALLEY AND WESTERN
LAKES AS THE PRESSURE GRADIENT TIGHTENS. WINDS WILL BACK TO THE
SOUTH AND INCREASE INTO THE 30 KT RANGE WEDNESDAY NIGHT AS THE LOW
SLOWLY MOVES EAST ACROSS THE PLAINS AND EVENTUALLY LIFTS NORTHEAST
ACROSS THE LAKE THURSDAY NIGHT. SOME MINOR DIFFERENCES REMAIN WITH
EXACT TIMING OF THE LOW PASSAGE BETWEEN THURSDAY EVENING AND
FRIDAY MORNING...THOUGH WINDS SHOULD SHIFT TO THE NORTHWEST BY
FRIDAY WITH A PERIOD OF 30 KT GUSTS LIKELY BEHIND THE DEPARTING
LOW. SOME GALE FORCE GUSTS MAY BE POSSIBLE ESPECIALLY ON THE
NORTHERN PART OF THE LAKE THURSDAY...THOUGH HAVE NOT MENTIONED IN
GLF DUE TO ABOVE MENTIONED MODEL DIFFERENCES AT THIS TIME.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...1 AM TUESDAY TO 10
PM TUESDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...4 AM TUESDAY TO 4
AM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
1223 PM CDT Mon Mar 24 2014
.DISCUSSION...
ISSUED 1012 AM CDT Mon Mar 24 2014
Earlier thick patch of altocumulus has thinned some and allowed
for some morning sunshine, but still some widespread cloudiness
off to our west. Couple areas of light snow west of the
Mississippi, one across Iowa and the other across northern Kansas,
as a shortwave zips across the central Plains. Latest look at
high-resolution models as well as the newly arrived NAM shows the
afternoon remaining dry in our area, with forecast soundings quite
parched below 7000 feet. Thus, have removed afternoon
precipitation from the forecast. Also did some tweaks to the grids
for tonight, as the main cold front arrives from the northwest.
The soundings and models mainly focusing on about a 3-5 hour
window of light snow, beginning this evening west of I-55 and
mainly after midnight to the east. Accumulations still looking
minor, mainly a couple tenths or so. Broke up the grids to reflect
the timing of the higher PoP`s, although this did not make any
significant change to the worded forecast.
Geelhart
&&
.AVIATION...
ISSUED 1223 PM CDT Mon Mar 24 2014
Ceilings expected to gradually lower this evening as a cold front
approaches from the northwest. Lots of dry air needed to be
overcome initially, but a 3-5 hour period of MVFR ceilings/
visibilities expected as light snow accompanies the passage of the
front. Based on the RAP model, have indicated a couple hours with
TEMPO groups on when the lowest visibilities are most likely in
the heavier bands of snow. Once the front clears, a brief period
of mostly clear skies expected until ceilings around 4000 feet
redevelop by mid-morning. Surface gusts over 20 knots likely to
develop late Tuesday morning.
Geelhart
&&
.PREV DISCUSSION...
ISSUED 305 AM CDT Mon Mar 24 2014
SHORT TERM...Today through Wednesday
Clouds will overspread central Illinois this morning as short-wave
energy over the Northern Plains/Rockies approaches from the
northwest. Water vapor imagery shows several weak impulses
embedded within the broad northwesterly flow pattern, with most
models focusing on the wave currently dropping into Wyoming as the
dominant weather feature to impact the region later today. This
particular wave will track southeastward into Missouri by 00z,
resulting in the strongest lift remaining just S/SW of the KILX CWA
this afternoon. Given the more southerly track of this main wave
and the fact that quite a bit of dry air will initially be in
place across the area, have scaled back afternoon PoPs. Will only
feature chance PoPs late this afternoon across the S/SE CWA, with
dry weather anticipated across the remainder of the area. Forecast
soundings still suggest ample evaporative cooling will lead to
light snow as precip initiates: however, surface temps around 40
could lead to a brief rain/snow mix south of I-70.
Second short-wave further upstream over Alberta/Saskatchewan will
swing through the region tonight. While decent lift will be
present with this feature, moisture will be limited. Am expecting
a period of light snow across all of central and southeast
Illinois from mid-evening through the overnight hours, with a
minor accumulation of around one half inch likely. May see a few
lingering snow-showers/flurries Tuesday morning before wave pushes
further east and skies become mostly sunny by afternoon. Main
weather story on Tuesday will be the cold and windy conditions.
Forecast sounding momentum transfer indicates northwesterly wind
gusts of 25 to 30 mph. These winds coupled with temperatures
hovering in the lower to middle 30s will produce wind-chill values
in the single digits and teens. Temps will begin to moderate by
Wednesday as progressive flow pattern allows upper heights to rise
considerably in the wake of the Tuesday system. Resulting highs
will be in the lower to middle 40s.
LONG TERM...Thursday through Sunday
There are still some minor model discrepancies in the extended:
however, overall trend will be for warmer weather. Vigorous
short-wave is progged to come onshore along the West Coast on
Wednesday, then track eastward into the region late Thursday into
Friday. One change seen on the 00z Mar 24 model suite concerns the
timing of an initial wave ahead of the main feature. NAM/GFS now
bring showers associated with this wave into central Illinois
much faster Wednesday night, while the ECMWF remains a bit slower
toward dawn Thursday. Given progressive flow pattern and strong
southerly flow behind departing high pressure allowing ample
moisture return, tend to favor the faster NAM/GFS here. As a
result will carry chance PoPs for rain showers late Wednesday
night. Showers will become more widespread on Thursday as the main
wave approaches from the west. Associated surface low pressure and
cold front arrive Thursday evening, with the ECMWF remaining about
6 to 12 hours slower than the GFS. Still think the faster GFS is
the way to go, with FROPA occurring Thursday evening. Will go with
likely PoPs and mention chance of thunder at that time. Friday is
shaping up to be a largely dry day as front quickly passes east of
the region. Will maintain low chance PoPs across the eastern CWA
in case front slows. After that, upper ridge builds across the
central CONUS and temps steadily warm through early next week.
With 850mb temps reaching the 10 to 12C range, above normal highs
well into the 60s will be likely by Sunday.
Barnes
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
102 PM CDT MON MAR 24 2014
.UPDATE...
ISSUED AT 1115 AM CDT MON MAR 24 2014
PRECIP EVOLUTION TODAY WILL SWITCH FROM SYNOPTIC FORCING TO MORE
OF A CONVECTIVE NATURE. FORECAST SOUNDINGS SHOW VERY DEEP
MIXING...PUSHING 2-3KM AT TIMES ESPECIALLY NORTHEAST...SUGGESTING
SNOW SHOWERS/SQUALLS WILL BE PREVALENT WHICH IS ALREADY SHOWING
ITS HAND OVER SRN MN. WINDS WILL NOT BE TOO EXTREME...BUT THE
COMBINATION OF SNOW BURSTS AND MODERATE GUSTS WILL PRODUCE PERIODS
OF LOW VISIBILITIES NORTH.
&&
.SHORT TERM /TODAY/...
ISSUED AT 316 AM CDT MON MAR 24 2014
DIFFICULT FORECAST FOR WHAT I BELIEVE WILL BE A LIGHT SNOW EVENT.
RADAR HAS BEEN SHOWING A BAND OF LIGHT SNOW FROM WEST OF SAC CITY
THROUGH THE DES MOINES METRO AREA THEN SOUTHEAST TO ABOUT CORYDON.
SOUNDINGS SHOW A DRY LAYER NEAR THE SURFACE AND A QUICK CHECK OF
SNOWFALL AFTER THREE AND A HALF HOURS OF SNOWFALL REVEALS DRY AIR
NEAR THE SURFACE IS INDEED IN PLACE. THERE IS BARELY A TENTH OF AN
INCH OF SNOW ON THE GROUND AT THE OFFICE. THERE ARE A LOT OF
PROBLEMS WITH THIS SYSTEM WHICH ARE GIVING MODELS FITS. FIRST IS
THE DISTINCT DRY LAYER NEAR THE SURFACE. THIS WILL IMPROVE SOME
THIS MORNING AS MOISTURE SATURATES A DEEPER LAYER. THE PROBLEM...IF
YOU CAN BELIEVE THE MODELS AT ALL IS THAT IT WILL COME IN SEVERAL
BOUTS. ANY FORCING THAT COMES ACROSS BEFORE WE CAN SATURATE WILL
YIELD VERY LITTLE SNOWFALL. HOWEVER IN THE PERIOD FROM MID MORNING
THROUGH EARLY AFTERNOON MANY LOCATIONS WILL LIKELY PICK UP AROUND AN
INCH PERHAPS LOCALLY TWO. ALL THE HI-RES MODELS EXPAND THE PRECIP
OVER OUR FORECAST AREA BY 18Z SO I FEEL CONFIDENT IS EXPANDING POPS
ACROSS THE AREA BUT THE NAM12 HAS HIGHER SNOWFALL IN THE NORTH
CENTRAL TO NORTHEAST WHILE THE HRRR HAS A CORRIDOR OF HIGHER AMOUNTS
ALONG AND EAST OF THE I-35 CORRIDOR. OTHER HI-RES MODELS VARY FROM
ALMOST NOTHING AT ALL BEING A LITTLE SLOWER IN MOVING THE EXPANSION
EAST.
I TRIED TO TIE HIGHER AMOUNTS TO LOCATIONS WHERE IT APPEARED FORCING
WOULD BE STRONGER FOR AT LEAST SEVERAL HOURS AND WHERE MOISTURE WAS
DEEPER.
AS FOR TEMPS...WENT BELOW GUIDANCE BY UP TO A CATEGORY. I CANNOT SEE
US CLIMBING MUCH TODAY GIVEN THE CLOUD COVER AND PRECIP. A CHECK OF
ROAD SURFACE TEMPS INDICATES ROAD SURFACES HAVE COOLED TO WELL BELOW
FREEZING SO TO BE PROACTIVE WE WILL HAVE A SPECIAL WEATHER STATEMENT
OUT TO INDICATE THE POTENTIAL FOR SLICK SPOTS.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 316 AM CDT MON MAR 24 2014
AS THE TROUGH PULLS AWAY...SNOW WILL END FROM WEST TO EAST
TONIGHT. A SECONDARY S/WV WILL BRING SOME LIGHT SNOW LATER
TONIGHT AND SLOW THE EASTWARD PROGRESS OF THE ENDING...BUT ALL
SHOULD BE OUT OF THE CWA BEFORE MORNING.
COLD HIGH PRESSURE WILL SETTLE IN BEHIND THE TROUGH AND KEEP TEMPS
WELL BELOW NORMAL FOR TUE INTO TUE NIGHT. CHANGES ARE IN THE
WORKS AS THE PATTERN SHIFTS NORTH. HEIGHTS BUILD INTO THE CENTRAL
U.S. WITH THE NORTHERN STREAM BEING PUSHED TO THE NORTH OF IA. THE
SOUTHERN STREAM WILL HAVE MORE INFLUENCE WITH TEMPS REBOUNDING
QUICKLY ON WED AND THU. KEPT THE THUNDER IN THE FORECAST AND HAVE
MOVED IT INTO THE SWRN ZONES LATE WED NIGHT WITH STRONG WAA AND
WARM FRONT JUST SOUTH OF THE CWA. WIDESPREAD RAIN AND ISOLD
THUNDER ON TAP FOR A GOOD PART OF THE CWA THU WITH ELEVATED CAPE
OVER THE SOUTH REACHING ABOUT 500 J/KG. LOW WILL PULL OUT THU
NIGHT WITH A MIX OF -RASN. ECMWF CONTINUES TO BE MORE INTENSE WITH
THIS SYSTEM...THOUGH UNCERTAINTY REMAINS...IT WILL NEEDED TO BE
MONITORED FOR THE POTENTIAL OF A NARROW BAND OF HEAVIER SNOW
BEHIND THE LOW.
FRIDAY WILL BE COOLER WITH SUB-NORMAL TEMPS. WARMING WILL SET IN
FOR THE WEEKEND WITH MUCH WARMER CONDITIONS BY SUN AND MON. ECMWF
A BIT FASTER WITH THE WARMING AND BRINGS 70S INTO THE STATE BY
SUN...THE GFS A BIT SLOWER AND HOLDS THEM OFF UNTIL MON. EITHER
WAS A SIGNIFICANT PUSH OF WARMER AIR IS SLATED FOR LATER THIS
WEEKEND INTO EARLY NEXT.
&&
.AVIATION...24/18Z
ISSUED AT 100 PM CDT MON MAR 24 2014
WIDESPREAD MVFR/IFR CONDITIONS EXIST OVER NRN AND ERN PORTIONS OF
THE AREA /KFOD/KMCW/KALO/ DUE TO LIGHT SNOW/VSBYS AND CIGS. MAINLY
MVFR SNOW SHOWERS/SQUALLS WILL ALSO ADVANCE SOUTH AND EAST INTO
THESE AREAS DURING THE LATE AFTERNOON AND EVENING HOURS. GENERALLY
VFR CONDITIONS SHOULD FOLLOW INTO THE NIGHT...ALTHOUGH THERE MAY
BE A BRIEF PERIOD OF MVFR SNOW AS WELL.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...SMALL
SHORT TERM...FAB
LONG TERM...MS MAR 14
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1119 AM CDT MON MAR 24 2014
.UPDATE...
ISSUED AT 1115 AM CDT MON MAR 24 2014
PRECIP EVOLUTION TODAY WILL SWITCH FROM SYNOPTIC FORCING TO MORE
OF A CONVECTIVE NATURE. FORECAST SOUNDINGS SHOW VERY DEEP
MIXING...PUSHING 2-3KM AT TIMES ESPECIALLY NORTHEAST...SUGGESTING
SNOW SHOWERS/SQUALLS WILL BE PREVALENT WHICH IS ALREADY SHOWING
ITS HAND OVER SRN MN. WINDS WILL NOT BE TOO EXTREME...BUT THE
COMBINATION OF SNOW BURSTS AND MODERATE GUSTS WILL PRODUCE PERIODS
OF LOW VISIBILITIES.
&&
.SHORT TERM /TODAY/...
ISSUED AT 316 AM CDT MON MAR 24 2014
DIFFICULT FORECAST FOR WHAT I BELIEVE WILL BE A LIGHT SNOW EVENT.
RADAR HAS BEEN SHOWING A BAND OF LIGHT SNOW FROM WEST OF SAC CITY
THROUGH THE DES MOINES METRO AREA THEN SOUTHEAST TO ABOUT CORYDON.
SOUNDINGS SHOW A DRY LAYER NEAR THE SURFACE AND A QUICK CHECK OF
SNOWFALL AFTER THREE AND A HALF HOURS OF SNOWFALL REVEALS DRY AIR
NEAR THE SURFACE IS INDEED IN PLACE. THERE IS BARELY A TENTH OF AN
INCH OF SNOW ON THE GROUND AT THE OFFICE. THERE ARE A LOT OF
PROBLEMS WITH THIS SYSTEM WHICH ARE GIVING MODELS FITS. FIRST IS
THE DISTINCT DRY LAYER NEAR THE SURFACE. THIS WILL IMPROVE SOME
THIS MORNING AS MOISTURE SATURATES A DEEPER LAYER. THE PROBLEM...IF
YOU CAN BELIEVE THE MODELS AT ALL IS THAT IT WILL COME IN SEVERAL
BOUTS. ANY FORCING THAT COMES ACROSS BEFORE WE CAN SATURATE WILL
YIELD VERY LITTLE SNOWFALL. HOWEVER IN THE PERIOD FROM MID MORNING
THROUGH EARLY AFTERNOON MANY LOCATIONS WILL LIKELY PICK UP AROUND AN
INCH PERHAPS LOCALLY TWO. ALL THE HI-RES MODELS EXPAND THE PRECIP
OVER OUR FORECAST AREA BY 18Z SO I FEEL CONFIDENT IS EXPANDING POPS
ACROSS THE AREA BUT THE NAM12 HAS HIGHER SNOWFALL IN THE NORTH
CENTRAL TO NORTHEAST WHILE THE HRRR HAS A CORRIDOR OF HIGHER AMOUNTS
ALONG AND EAST OF THE I-35 CORRIDOR. OTHER HI-RES MODELS VARY FROM
ALMOST NOTHING AT ALL BEING A LITTLE SLOWER IN MOVING THE EXPANSION
EAST.
I TRIED TO TIE HIGHER AMOUNTS TO LOCATIONS WHERE IT APPEARED FORCING
WOULD BE STRONGER FOR AT LEAST SEVERAL HOURS AND WHERE MOISTURE WAS
DEEPER.
AS FOR TEMPS...WENT BELOW GUIDANCE BY UP TO A CATEGORY. I CANNOT SEE
US CLIMBING MUCH TODAY GIVEN THE CLOUD COVER AND PRECIP. A CHECK OF
ROAD SURFACE TEMPS INDICATES ROAD SURFACES HAVE COOLED TO WELL BELOW
FREEZING SO TO BE PROACTIVE WE WILL HAVE A SPECIAL WEATHER STATEMENT
OUT TO INDICATE THE POTENTIAL FOR SLICK SPOTS.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 316 AM CDT MON MAR 24 2014
AS THE TROUGH PULLS AWAY...SNOW WILL END FROM WEST TO EAST
TONIGHT. A SECONDARY S/WV WILL BRING SOME LIGHT SNOW LATER
TONIGHT AND SLOW THE EASTWARD PROGRESS OF THE ENDING...BUT ALL
SHOULD BE OUT OF THE CWA BEFORE MORNING.
COLD HIGH PRESSURE WILL SETTLE IN BEHIND THE TROUGH AND KEEP TEMPS
WELL BELOW NORMAL FOR TUE INTO TUE NIGHT. CHANGES ARE IN THE
WORKS AS THE PATTERN SHIFTS NORTH. HEIGHTS BUILD INTO THE CENTRAL
U.S. WITH THE NORTHERN STREAM BEING PUSHED TO THE NORTH OF IA. THE
SOUTHERN STREAM WILL HAVE MORE INFLUENCE WITH TEMPS REBOUNDING
QUICKLY ON WED AND THU. KEPT THE THUNDER IN THE FORECAST AND HAVE
MOVED IT INTO THE SWRN ZONES LATE WED NIGHT WITH STRONG WAA AND
ARM FRONT JUST SOUTH OF THE CWA. WIDESPREAD RAIN AND ISOLD THUNDER
ON TAP FOR A GOOD PART OF THE CWA THU WITH ELEVATED CAPE OVER THE
SOUTH REACHING ABOUT 500 J/KG. LOW WILL PULL OUT THU NIGHT WITH A
MIX OF -RASN. ECMWF CONTINUES TO BE MORE INTENSE WITH THIS
SYSTEM...THOUGH UNCERTAINTY REMAINS...IT WILL NEEDED TO BE
MONITORED FOR THE POTENTIAL OF A NARROW BAND OF HEAVIER SNOW
BEHIND THE LOW.
FRIDAY WILL BE COOLER WITH SUB-NORMAL TEMPS. WARMING WILL SET IN
FOR THE WEEKEND WITH MUCH WARMER CONDITIONS BY SUN AND MON. ECMWF
A BIT FASTER WITH THE WARMING AND BRINGS 70S INTO THE STATE BY
SUN...THE GFS A BIT SLOWER AND HOLDS THEM OFF UNTIL MON. EITHER
WAS A SIGNIFICANT PUSH OF WARMER AIR IS SLATED FOR LATER THIS
WEEKEND INTO EARLY NEXT.
&&
.AVIATION...24/12Z
ISSUED AT 655 AM CDT MON MAR 24 2014
RADAR IMAGERY SHOWING SNOW DIMINISHING AT THE PRESENT BUT THERE
WILL BE ANOTHER ROUND OR TWO THIS MORNING BEFORE DIMINISHING
FURTHER. MVFR CIGS AND VSBYS WITH LOCAL IFR CIGS LIKELY ACROSS TAF
LOCATIONS THROUGH TODAY BEFORE GRADUAL IMPROVEMENT. LOWER CLOUDS
WERE FAIRLY TRANSIENT AND NOT EXPANDING SO THEY ARE NOT INCLUDED IN
TAFS. THOSE MAY NEED TO BE HANDLED WITH AMD/S IF THEY EXPAND...
THOUGH I AM NOT EXPECTING THAT.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SMALL
SYNOPSIS...MS MAR 14
SHORT TERM...FAB
LONG TERM...MS MAR 14
AVIATION...FAB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
252 PM MDT MON MAR 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 230 PM MDT MON MAR 24 2014
AS OF 2 P.M. MDT...VISIBLE SATELLITE IMAGERY INDICATED A DENSELY
POPULATED CUMULUS FIELD ACROSS THE TRI STATE AREA...WITH PARTLY TO
MOSTLY CLOUDY SKIES. NO SIGNIFICANT RADAR RETURNS WERE OBSERVED AS
DRY CONDITIONS WERE PRESENT ACROSS THE REGION.
UPPER LEVEL LONG WAVE TROUGH MOVES EASTWARD OUT OF THE CENTRAL
PLAINS AS STRONGER AREA OF THE JET MOVES DOWN THE HIGH PLAINS THIS
EVENING AND OVERNIGHT. HIGHER VORTICITY POCKET WILL HELP CREATE LIFT
TO GENERATE INCREASED CLOUD COVER FOR AREAS EAST OF HIGHWAY 83
TONIGHT. UPPER LEVEL TROUGH WILL MOVE INTO THE TRI STATE AREA FROM
THE WEST TO BRING CLEARING SKIES TO AREAS WEST OF HIGHWAY 83
OVERNIGHT.
LOW TEMPERATURES TONIGHT WILL STAY A BIT WARMER FOR AREAS EAST OF
HIGHWAY 83 WITH THE INCREASED CLOUD COVER...BUT TEMPERATURES WILL
REACH THE UPPER TEENS WITH THE AREAS OF CLEARING CLOUD COVER.
TEMPERATURES WILL DROP TO NEAR THE DEW POINTS WITH RELATIVE
HUMIDITIES AT THE SURFACE APPROACHING ONE HUNDRED PERCENT...WHICH
COULD CREATE SOME AREAS OF PATCHY FOG IN EASTERN COLORADO AND AREAS
WEST OF KANSAS HIGHWAY 27. RAP MODEL SOUNDINGS SHOW TEMPERATURES
WARMING IN THE MID MORNING...WHICH WILL BRING RAPID CLOUD CLEARING
WITH INCREASED SUBSIDENCE FROM THE SURFACE HIGH PRESSURE THAT MOVES
INTO THE HIGH PLAINS. AS SURFACE HIGH MOVES EASTWARD
TOMORROW...SOUTHERLY FLOW AND INCREASED WARM AIR ADVECTION WILL
ALLOW HIGH TEMPERATURES TO REACH THE LOW TO MID 50S. THE WARMEST
TEMPERATURES WILL BE ALONG THE KANSAS AND COLORADO STATE BOUNDARY AS
WARM FRONT WITH ASSOCIATED CYCLOGENESIS WILL BRING THE HIGHEST
TEMPERATURES. PROBABILITY FOR PRECIPITATION IS NEXT TO NONE TONIGHT
AND TOMORROW.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 251 PM MDT MON MAR 24 2014
TUESDAY NIGHT-THURSDAY...SHORT WAVE RIDGING EXPECTED TO BE DOMINANT
FORCING MECHANISM ACROSS THE FORECAST AREA DURING THE START OF THE
PERIOD...ALTHOUGH MORE ACTIVE WEATHER WILL DEVELOP ACROSS THE AREA
AS A SERIES OF PROGRESSIVE SHORT WAVE TROUGHS BEGINS TO INFLUENCE
THE AREA ON WEDNESDAY. INITIAL WEATHER CONCERNS WILL CENTER AROUND
POSITION OF WEAK DRY LINE EXPECTED TO BISECT THE AREA ON WEDNESDAY
AFTERNOON. TEMPERATURES WILL CLIMB INTO THE LOWER 70S TO THE WEST OF
IT...WITH AFTERNOON HUMIDITIES FALLING TO THE 15 PERCENT. THE
COMBINATION OF WARM TEMPS...DRY FUELS AND WESTERLY WINDS OF 15 TO 25
MPH WILL BRING THE POTENTIAL FOR CRITICAL FIRE WEATHER CONDITIONS.
WILL NEED TO WATCH FOR POTENTIAL WATCH OR WARNING AS THIS TIME
NEARS...BUT CURRENTLY IS A BIT TOO FAR OUT IN TIME TO WARRANT A
WATCH AT THIS POINT. TO THE EAST OF THE DRY LINE...STRONG SOUTHERLY
WINDS WILL NEAR ADVISORY LEVELS AS A NARROW AREA OF INSTABILITY
DEVELOPS ALONG IT. WILL LIKELY SEE A WEAK STORM OR TWO DEVELOP IN
THIS AREA...BUT WITH LIMITED INSTABILITY DO NOT EXPECT STRONG OR
WIDESPREAD STORMS ATTM. SHORT WAVE TROUGH...AS PER 1.5 PVU PRESSURE
ANOMALY...WILL BEGIN TO MOVE ACROSS THE AREA WEDNESDAY EVENING
BRINGING A PERIOD OF FORCED ASCENT...MAINLY TO THE NORTHERN CWA.
MODELS REALLY DIVERGE ON HOW THIS SYSTEM EVOLVES...RANGING FROM ONE
STRONG PERIOD OF FORCING TO SEVERAL INDIVIDUAL WAVES LINGERING
THROUGH THURSDAY. WITH LARGE DIFFERENCES BETWEEN OPERATIONAL MODELS
AND ENSEMBLE DATA FURTHER RAISING UNCERTAINTY...AM GOING TO KEEP
GENERAL FORECAST INTACT AND LIMIT POPS TO THE 30 TO 50 PERCENT RANGE.
IN THE EXTENDED (THURSDAY NIGHT-MONDAY)...WARMER AND DRIER WEATHER
WILL DEVELOP ACROSS THE AREA AS BROAD RIDGING BUILDS OVER THE AREA.
EXPECT TEMPERATURES TO WARM INTO THE UPPER 70S BY SUNDAY. ALTHOUGH
STANDARD DEVIATIONS OF THE ENSEMBLES REMAIN QUITE HIGH DURING THE
PERIOD...OVERALL MODEL AGREEMENT ON THE OVERALL PATTERN LEADS ME TO
LEAN TOWARDS WARMER SOLUTIONS. OVERALL QUIET WEATHER IS EXPECTED
ALTHOUGH FIRE DANGER WILL INCREASE AS THE TEMPS RISE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1117 AM MDT MON MAR 24 2014
UPPER LEVEL JET WILL BRING INCREASED CLOUDINESS FOR KGLD THIS
AFTERNOON AND EVENING...WITH MVFR CONDITIONS BRIEFLY THIS
AFTERNOON. AS SUBSIDENCE INCREASES WITH THE SURFACE HIGH
PRESSURE...CLOUDS WILL BEGIN TO BREAK TOWARD THE MORNING HOURS
WITH LIGHT WINDS. VFR CONDITIONS ARE EXPECTED OVERNIGHT THROUGH
THE END OF THE TAF PERIOD.
CLOUD COVER AT KMCK WILL BE MORE PERSISTENT THIS AFTERNOON THROUGH
THIS EVENING WITH OVERCAST CEILINGS...BUT HEIGHTS WILL REMAIN VFR
THROUGH THE ENTIRE PERIOD WITH LIGHT WIND SHIFTS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...MK
LONG TERM...JRM
AVIATION...MK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
230 PM MDT MON MAR 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 230 PM MDT MON MAR 24 2014
AS OF 2 P.M. MDT...VISIBLE SATELLITE IMAGERY INDICATED A DENSELY
POPULATED CUMULUS FIELD ACROSS THE TRI STATE AREA...WITH PARTLY TO
MOSTLY CLOUDY SKIES. NO SIGNIFICANT RADAR RETURNS WERE OBSERVED AS
DRY CONDITIONS WERE PRESENT ACROSS THE REGION.
UPPER LEVEL LONG WAVE TROUGH MOVES EASTWARD OUT OF THE CENTRAL
PLAINS AS STRONGER AREA OF THE JET MOVES DOWN THE HIGH PLAINS THIS
EVENING AND OVERNIGHT. HIGHER VORTICITY POCKET WILL HELP CREATE LIFT
TO GENERATE INCREASED CLOUD COVER FOR AREAS EAST OF HIGHWAY 83
TONIGHT. UPPER LEVEL TROUGH WILL MOVE INTO THE TRI STATE AREA FROM
THE WEST TO BRING CLEARING SKIES TO AREAS WEST OF HIGHWAY 83
OVERNIGHT.
LOW TEMPERATURES TONIGHT WILL STAY A BIT WARMER FOR AREAS EAST OF
HIGHWAY 83 WITH THE INCREASED CLOUD COVER...BUT TEMPERATURES WILL
REACH THE UPPER TEENS WITH THE AREAS OF CLEARING CLOUD COVER.
TEMPERATURES WILL DROP TO NEAR THE DEW POINTS WITH RELATIVE
HUMIDITIES AT THE SURFACE APPROACHING ONE HUNDRED PERCENT...WHICH
COULD CREATE SOME AREAS OF PATCHY FOG IN EASTERN COLORADO AND AREAS
WEST OF KANSAS HIGHWAY 27. RAP MODEL SOUNDINGS SHOW TEMPERATURES
WARMING IN THE MID MORNING...WHICH WILL BRING RAPID CLOUD CLEARING
WITH INCREASED SUBSIDENCE FROM THE SURFACE HIGH PRESSURE THAT MOVES
INTO THE HIGH PLAINS. AS SURFACE HIGH MOVES EASTWARD
TOMORROW...SOUTHERLY FLOW AND INCREASED WARM AIR ADVECTION WILL
ALLOW HIGH TEMPERATURES TO REACH THE LOW TO MID 50S. THE WARMEST
TEMPERATURES WILL BE ALONG THE KANSAS AND COLORADO STATE BOUNDARY AS
WARM FRONT WITH ASSOCIATED CYCLOGENESIS WILL BRING THE HIGHEST
TEMPERATURES. PROBABILITY FOR PRECIPITATION IS NEXT TO NONE TONIGHT
AND TOMORROW.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 342 AM MDT MON MAR 24 2014
LARGE SCALE PATTERN SHOWS A STRONG SHORTWAVE TROUGH PROGRESSING
THROUGH THE CWA ON THURSDAY WITH WEAK RIDGING OVER THE CENTRAL
PLAINS TOWARDS THE END OF THE WEEK INTO THE WEEKEND. AT THE
SURFACE...A LOW PRESSURE SYSTEM WILL MOVE THROUGH THE CWA ON
THURSDAY...WITH WRAP AROUND PRECIPITATION THURSDAY NIGHT INTO
FRIDAY. WENT AHEAD AND ACCEPTED THE ALLBLEND FOR PRECIP SINCE IT
GAVE AROUND 30 TO 40 PERCENT CHANCES. INITIAL PRECIP TYPE SHOULD BE
RAIN...WHICH WILL OCCUR ON THURSDAY. LATE THURSDAY NIGHT INTO FRIDAY
MORNING...PRECIPITATION SHOULD CHANGE OVER TO SNOW AS COLDER AIR
MOVES IN BEHIND THE UPPER SHORTWAVE TROUGH WITH THE SURFACE HIGH.
ACCUMULATIONS SHOULD BE MINIMAL AT THIS TIME WITH AROUND A TENTH OF
AN INCH TO A HALF AN INCH. THESE VALUES MAY CHANGE AS THE MODELS
DEVELOP THIS SYSTEM BETTER IN THE SHORT TERM. TEMPERATURES WILL BE
SLIGHTLY BELOW TO NEAR NORMAL ON THURSDAY INTO FRIDAY...WITH HIGHS
IN THE UPPER 40S TO UPPER 50S ON THURSDAY AND HIGHS IN THE MID TO
UPPER 50S ON FRIDAY. LOWS WILL BE IN THE UPPER 20S TO LOW 30S
THURSDAY AND FRIDAY NIGHT.
BEYOND FRIDAY MORNING...THE WEAK RIDGE SETS UP AND A FEW MINOR
SHORTWAVE TROUGHS ROTATE THROUGH THE CWA. NO PRECIP IS EXPECTED WITH
THESE WEAK WAVES MOVING THROUGH...SO LEFT THE REMAINDER OF THE
EXTENDED DRY. SOUTHERLY SURFACE FLOW WILL BRING IN WARMER AIR WITH
HIGH TEMPERATURES WARMING UP THROUGHOUT THE WEEKEND. HIGHS ON
SATURDAY WILL REACH THE MID TO UPPER 60S WITH HIGHS ON SUNDAY IN THE
LOW TO MID 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1117 AM MDT MON MAR 24 2014
UPPER LEVEL JET WILL BRING INCREASED CLOUDINESS FOR KGLD THIS
AFTERNOON AND EVENING...WITH MVFR CONDITIONS BRIEFLY THIS
AFTERNOON. AS SUBSIDENCE INCREASES WITH THE SURFACE HIGH
PRESSURE...CLOUDS WILL BEGIN TO BREAK TOWARD THE MORNING HOURS
WITH LIGHT WINDS. VFR CONDITIONS ARE EXPECTED OVERNIGHT THROUGH
THE END OF THE TAF PERIOD.
CLOUD COVER AT KMCK WILL BE MORE PERSISTENT THIS AFTERNOON THROUGH
THIS EVENING WITH OVERCAST CEILINGS...BUT HEIGHTS WILL REMAIN VFR
THROUGH THE ENTIRE PERIOD WITH LIGHT WIND SHIFTS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...MK
LONG TERM...ALW
AVIATION...MK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
438 PM EDT MON MAR 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 415 PM EDT MON MAR 24 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE OVER
WRN NOAM AND A TROUGH FROM HUDSON BAY THROUGH MUCH OF THE ERN CONUS.
AN UPSTREAM SHORTWAVE TROUGH AND ASSOCIATED ARCTIC COLD FRONT
EXTENDED FROM NEAR JAMES BAY TO FAR NW MN. TO THE NORTH OF THE FRONT
19Z TEMPS ONLY RANGED FROM 0F TO 5F. AT THE SFC...WRLY LOW LEVEL
FLOW PREVAILED AHEAD OF THE FRONT WITH ONLY SCT-BKN DIURNAL CU/SC
OVER UPPER MICHIGAN.
TONIGHT...AS THE SHORTWAVE TROUGH AND COLD FRONT MOVE ACROSS THE NRN
GREAT LAKES SOME WEAK Q-VECT CONV...SFC-700 MB MOISTENING AND LOW
LEVEL CONV SHOULD SUPPORT SCT LIGHT SNOW SHOWERS OR FLURRIES...PER
UPSTREAM OBS. THE GREATEST PCPN CHANCES AND POTENTIAL FOR SOME LIGHT
ACCUMULATIONS OF AN INCH OR LESS IS EXPECTED DOWNWIND FROM LAKE
SUPERIOR WHERE EVEN SMALL GAPS IN THE ICE COVER WILL ADD
HEAT/INSTABILITY. UPSLOPE FLOW INTO THE HIGHER TERRAIN WILL ALSO
PROVIDE ADDITIONAL SUPPORT FOR THE PCPN. LOOK FOR MIN TEMPS MAINLY IN
THE SINGLE DIGITS ABOVE ZERO BUT A FEW BLO ZERO READINGS ARE POSSIBLE
OVER THE EASTERN INTERIOR FCST AREA WHERE WINDS WILL BE LIGHTER AHEAD
OF THE FRONT IN THE EVENING.
TUESDAY...AS HIGH PRESSURE AND SUBSIDENCE BUILD INTO THE WRN
LAKES...THE 850-700 MB MOISTURE DEPARTS AND WINDS BACK TO
WRLY...EXPECT THE PCPN TO DIMINISH WITH ONLY A LIGHT DUSTING OF
ACCUMULATION AT MOST. WITH 925/850 MB TEMPS ONLY TO AROUND
-16/-22C...TEMPS WILL STRUGGLE THROUGH THE MID TEENS...MORE THAN 20
DEGREES BELOW SEASONAL AVERAGES.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 438 PM EDT MON MAR 24 2014
THE EXTENDED PORTION OF THE FORECAST IS TRENDING TOWARDS A MORE
ACTIVE AND SPRING LIKE PATTERN.
A HIGH PRESSURE RIDGE MOVING OVER THE UPPER GREAT LAKES REGION TO
START THE PERIOD WILL LEAD TO ANOTHER VERY COLD NIGHT ACROSS THE
UPPER GREAT LAKES REGION ON TUESDAY NIGHT. THERE ARE SOME CONCERNS
FOR CLOUDS LINGERING...BUT WITH THE VERY LIMITED OPEN WATER ON LAKE
SUPERIOR WOULD THINK THERE IS A LACK OF SUPPORT FOR LAKE ENHANCED
CLOUDS TO LINGER. THUS...WOULD EXPECT CLEARING SKIES AND A DECENT
OPPORTUNITY FOR RADIATIONAL COOLING WITH WINDS BECOMING LIGHT.
SINCE PWAT VALUES ARE AROUND 30 PERCENT OF NORMAL...OPTED TO TREND
TEMPS DOWN (BASED OFF THE LAST TWO NIGHTS OF LOWS)...ESPECIALLY IN
THE TRADITIONAL INTERIOR COLD SPOTS. THIS PRODUCES LOWS BELOW ZERO
OVER PRETTY MUCH ALL OF THE U.P. AND IN THE TEENS BELOW ZERO OVER
THE INTERIOR. BASED OFF THE TRENDS IN THE LONGER RANGE
MODELS...THIS WILL LIKELY BE THE LAST REALLY COLD NIGHT ACROSS THE
REGION.
THE SURFACE RIDGE WILL QUICKLY SHIFT EAST OF THE AREA ON WEDNESDAY
AND ALLOW SOUTHERLY FLOW TO DEVELOP AHEAD OF THE LOW TAKING SHAPE
IN THE CENTRAL PLAINS. THIS SOUTHERLY FLOW WILL ALLOW TEMPERATURES
TO QUICKLY WARM INTO THE 20S (AIDED BY MORNING SUNSHINE). BUT HIGH
CLOUDS WILL BE QUICKLY STREAMING OVER THE AREA THROUGH THE DAY
AHEAD OF THE NEXT SYSTEM. COULD EVEN SEE A ISOLATED SHOWER OR TWO
DEVELOPING UNDER THE MID LEVEL WAA LATE IN THE AFTERNOON.
THE FIRST WAVE FROM THE SYSTEM WILL AFFECT THE AREA ON WEDNESDAY
NIGHT...AS A SURFACE TROUGH EXTENDING NORTHEAST FROM THE DEVELOPING
SURFACE LOW MOVES EAST OVER THE CWA. BROAD MID LEVEL WARM AIR
ADVECTION AND ISENTROPIC ASCENT ON THE 280-295K SFCS SHOULD LEAD TO
A SWATH OF LIGHT SNOW. AS WITH THE NEXT SYSTEM...MODELS VARY
SIGNIFICANTLY WITH THE STRENGTH AND LOCATION OF THIS AREA OF
SNOW. THE 12Z ECMWF IS THE FARTHEST NORTH (OVER LAKE SUPERIOR) AND
WEAKEST...12Z CANADIAN FARTHEST SOUTH (ACROSS THE U.P.) AND
STRONGEST...WHILE THE GFS IS IN BETWEEN. FELT THAT THE GFS WAS A
GOOD COMPROMISE BETWEEN THE SOLUTIONS AND FOLLOWED THAT FOR TIMING
AND SNOWFALL AMOUNTS. THAT GIVES A GENERAL 1-3 INCHES OF SNOW FOR
THE CWA (GREATEST NORTH THIRD) THROUGH 12Z THURSDAY.
NEXT WAVE OF PRECIP WILL ARRIVE AS THE LOW PULLS OUT OF THE CENTRAL
PLAINS AND THROUGH THE GREAT LAKES REGION. STILL SOME DIFFERENCES IN
THE EXACT TRACK/TIMING BUT AT LEAST INITIALLY THE MODELS ARE
CONSISTENT IN A TROUGH EXTENDING NORTH-NORTHEAST OVER WESTERN LAKE
SUPERIOR. AS FOR THE LOW...THE 12Z GFS CONTINUES TO MOVE THE LOW
THROUGH MUCH FASTER THAN THE 12Z GEM AND 12Z ECMWF (270MI/520MI
NORTHEAST AT 12Z FRIDAY RESPECTIVELY). THE 12Z GEM WAS MUCH FARTHER
TO THE NORTHWEST AND BROUGHT IN MUCH MORE WARM AIR (0C 850MB LINE IN
FAR WESTERN UPPER MICHIGAN AT 00Z FRIDAY). 12Z ECMWF...EVEN WITH
IT/S FARTHER SOUTHWEST LOW TRACK (THROUGH CENTRAL LOWER MI ON
FRIDAY) HAS THE 0C 925MB TEMP AREA SLIDING THROUGH SOUTHERN
UPPER MICHIGAN DURING THE DAY THURSDAY. THE GFS ON THE OTHER
HAND...MOVES THE LOW THROUGH SO FAST THAT THE WARM AIR DOESN/T HAVE
TIME TO PULL INTO THE AREA AND KEEPS IT AS ALL SNOW.
ESSENTIALLY...THESE DIFFERENCES ARE DUE TO THE HANDLING OF THE
DISTURBANCE THAT IS WELL OFFSHORE IN THE PACIFIC AND WON/T COME ON
SHORE UNTIL TUESDAY NIGHT. IT WILL PROBABLY BE 24-36HRS BEFORE THE
MODELS CAN LOCK INTO A SOLUTION...BUT FEEL A SEVERAL MEMBER
COMPROMISE IS REASONABLE (GEM/ECMWF FOR TIMING AND GFS/ECMWF/UKMET
FOR TRACK AND ECMWF FOR THERMAL PROFILE). FELT WEIGHTING MORE
HEAVILY TOWARDS THE ECMWF WAS WARRANTED BASED OFF THE CONSISTENCY
IN THE LOW TRACK WITH THE 00Z ENSEMBLE MEMBERS.
UNFORTUNATELY...THESE DIFFERENCE IN THE LOW TRACK AFFECT BOTH THE
PRECIPITATION TYPE FOR A PORTION OF THE AREA AND ALSO WHERE THE
HEAVIEST PRECIPITATION WILL BE LOCATED WITH THE DEFORMATION BAND ON
THE BACKSIDE OF THE LOW. AS THE LOW IS TAKING SHAPE ON
THURSDAY...SHOULD SEE A TROUGH SETTING UP OVER WESTERN LAKE SUPERIOR
AND WOULD EXPECT THE HEAVIEST PRECIPITATION TO BE OVER THE WESTERN
THIRD OF THE CWA AND THE WESTERN LAKE AS IT WILL BE ENHANCED BY
MID-LEVEL FGEN. OVER THE REST OF THE AREA AND ESPECIALLY THE SOUTH
CENTRAL...WOULD EXPECT THE WAA PRECIPITATION TO SHIFT OUT AND
DIMINISH AND POTENTIALLY CUT OUT THE DEEPER MOISTURE ON THURSDAY.
THIS COULD LEAD TO MORE OF A FOG/DRIZZLE PERIOD...BUT WITH THE
UNCERTAINTY WITH THE LOW TRACK WILL JUST KEEP THINGS AS SNOW WITH
RAIN MIXED IN AT TIMES. THEN AS THE LOW MOVES UP AND THROUGH THE
AREA...THE HEAVIER BAND OF PRECIP WILL SHIFT EAST ACROSS THE CWA
THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. ALL IN ALL...THE
CONDITIONS WEDNESDAY NIGHT INTO FRIDAY MORNING WILL LIKELY LEAD TO A
PERIOD OF MESSY TRAVEL/COMMUTES AND WILL CONTINUE TO HIGHLIGHT IN
THE HWO.
BEHIND THE LOW...HIGH PRESSURE WILL SETTLE OVER THE AREA FOR FRIDAY
NIGHT AND INTO SATURDAY. 850MB TEMPS OF -12C ARE PRETTY MARGINAL
FOR ANY LAKE EFFECT IF POCKETS OF OPEN WATER DEVELOP ON LAKE
SUPERIOR...SO WILL GO WITH DRY CONDITIONS ON FRIDAY NIGHT. THE HIGH
WILL SHIFT EAST ON SATURDAY AND SOUTHERLY FLOW SHOULD LEAD TO HIGHS
IN THE 30S.
FOCUS THEN TURNS TO THE NEXT SERIES OF WAVES COMING FROM THE
WESTERN CONUS AND BRINGING ANOTHER UNSETTLED PERIOD TO THE AREA
THROUGH THE FIRST HALF OF NEXT WEEK. THE FIRST POTENTIAL WAVE LOOKS
TO RUN EAST ON THE U.S./CANADIAN BORDER ON SATURDAY NIGHT AND
SHOULD HAVE A LIMITED AFFECT ON THE LAND CWA. BEHIND THIS
WAVE...MUCH WARMER AIR WILL MOVE INTO THE AREA AND CURRENT
INDICATIONS ARE FOR TEMPERATURES TO BE AT OR EVEN SLIGHTLY ABOVE
NORMAL FOR SUNDAY. GFS CONTINUES TO SHOW ISSUES WITH SNOW COVER AND
SURFACE TEMPS...SO WILL LEVERAGE THE CANADIAN/ECMWF FOR HIGHS ON
SUNDAY. SHOULD SEE 40S OVER MUCH OF THE AREA (EXCEPT OVER THE EAST
WITH WINDS OFF LAKE MICHIGAN) AND THERE IS EVEN THE POTENTIAL FOR
SOME 50S ALONG THE WISCONSIN BORDER. THE NEXT SHORTWAVE AND COLD
FRONT WILL BE SHIFTING THROUGH THE AREA LATE SUNDAY AFTERNOON AND
SUNDAY NIGHT AND WITH THE EXPECTED THERMAL PROFILE...THAT
PRECIPITATION SHOULD MAINLY FALL AS RAIN. LIKE THE END OF THIS
WEEK...ANOTHER LOW TAKING SHAPE IN THE PLAINS STATES ON SUNDAY WILL
LIKELY MOVE THROUGH THE GREAT LAKES REGION ON MONDAY AND MONDAY
NIGHT...BRINGING ANOTHER WIDESPREAD PRECIPITATION EVENT TO THE AREA.
INITIAL THOUGH ON P-TYPE IS FOR A MIX INITIALLY AND TRANSITIONING TO
ALL SNOW THROUGH THE DAY/EVENING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 147 PM EDT MON MAR 24 2014
STEEP LOW TO MID LEVEL LAPSE RATES WILL SUPPORT CU/SC THROUGH THIS
AFTERNOON. WITH THE APPROACH OF A DISTURBANCE FROM THE NW IN THE
AFTN...SCT -SHSN WILL THEN LIKELY DEVELOP AT KIWD/KSAW WITH
POTENTIAL OF BRIEF MVFR VIS AT TIMES...ESPECIALLY AT KIWD.
COLD/STABILIZING FLOW OFF MOSTLY SNOW/ICE COVERED LAKE SUPERIOR WILL
PROBABLY PREVENT -SHSN FROM DEVELOPING AROUND KCMX...ALLOWING VFR
CONDITIONS TO PREVAIL THERE. HOWEVER...BY LATE TONIGHT INTO TUE
MORNING...THE COMBINATION OF LOW LEVEL CONV AND UPSLOPE FLOW WILL BE
ENOUGH TO SUPPORT MVFR CIGS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 415 PM EDT MON MAR 24 2014
A COLD FRONT WILL MOVE THROUGH THE NRN LAKES TONIGHT. BEHIND THE
FRONT...WINDS WILL SHIFT TO THE NORTHWEST AND INCREASE TO 15 TO 25
KT TONIGHT AND 20 TO 30 KTS ON TUESDAY...WITH THE HIGHEST GUSTS OVER
THE EASTERN HALF OF LAKE SUPERIOR. WINDS WILL QUICKLY DIMINISH
TUESDAY NIGHT AND WEDNESDAY AS ANOTHER HIGH PRESSURE RIDGE MOVES
OVER THE AREA. A LOW PRESSURE SYSTEM DEVELOPING IN THE CENTRAL
PLAINS ON WEDNESDAY NIGHT AND THURSDAY WILL MOVE THROUGH THE GREAT
LAKES REGION LATE THURSDAY NIGHT AND FRIDAY. WIND STRENGTH/DIRECTION
WILL DEPEND ON THE EXACT TRACK OF THE LOW...BUT AT THIS TIME NORTH
TO NORTHEAST WINDS OF 15 TO 25 KTS ARE EXPECTED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
416 PM EDT MON MAR 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 415 PM EDT MON MAR 24 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE OVER
WRN NOAM AND A TROUGH FROM HUDSON BAY THROUGH MUCH OF THE ERN CONUS.
AN UPSTREAM SHORTWAVE TROUGH AND ASSOCIATED ARCTIC COLD FRONT
EXTENDED FROM NEAR JAMES BAY TO FAR NW MN. TO THE NORTH OF THE FRONT
19Z TEMPS ONLY RANGED FROM 0F TO 5F. AT THE SFC...WRLY LOW LEVEL
FLOW PREVAILED AHEAD OF THE FRONT WITH ONLY SCT-BKN DIURNAL CU/SC
OVER UPPER MICHIGAN.
TONIGHT...AS THE SHORTWAVE TROUGH AND COLD FRONT MOVE ACROSS THE NRN
GREAT LAKES SOME WEAK Q-VECT CONV...SFC-700 MB MOISTENING AND LOW
LEVEL CONV SHOULD SUPPORT SCT LIGHT SNOW SHOWERS OR FLURRIES...PER
UPSTREAM OBS. THE GREATEST PCPN CHANCES AND POTENTIAL FOR SOME LIGHT
ACCUMULATIONS OF AN INCH OR LESS IS EXPECTED DOWNWIND FROM LAKE
SUPERIOR WHERE EVEN SMALL GAPS IN THE ICE COVER WILL ADD
HEAT/INSTABILITY. UPSLOPE FLOW INTO THE HIGHER TERRAIN WILL ALSO
PROVIDE ADDITIONAL SUPPORT FOR THE PCPN. LOOK FOR MIN TEMPS MAINLY IN
THE SINGLE DIGITS ABOVE ZERO BUT A FEW BLO ZERO READINGS ARE POSSIBLE
OVER THE EASTERN INTERIOR FCST AREA WHERE WINDS WILL BE LIGHTER AHEAD
OF THE FRONT IN THE EVENING.
TUESDAY...AS HIGH PRESSURE AND SUBSIDENCE BUILD INTO THE WRN
LAKES...THE 850-700 MB MOISTURE DEPARTS AND WINDS BACK TO
WRLY...EXPECT THE PCPN TO DIMINISH WITH ONLY A LIGHT DUSTING OF
ACCUMULATION AT MOST. WITH 925/850 MB TEMPS ONLY TO AROUND
-16/-22C...TEMPS WILL STRUGGLE THROUGH THE MID TEENS...MORE THAN 20
DEGREES BELOW SEASONAL AVERAGES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 449 AM EDT MON MAR 24 2014
BY 12Z TUESDAY THE COLD AIR WILL ALREADY BE OVERHEAD. THE SFC TROUGH
WILL BE OVER FAR E UPPER MI AND LAKE HURON...WITH STEADY NW WINDS
AND 850MB TEMPS ALREADY AT A CHILLY -19C. EXPECT THE COLDEST AIR
OVERHEAD BY MID AFTERNOON /AROUND -20 TO -24C/. HOWEVER...GIVEN THE
END OF MARCH SUN...TEMPS SHOULD STILL BE ABLE TO RISE INTO THE TEENS
TO NEAR 20F.
THE HIGH PRESSURE SYSTEM DRAPED ACROSS THE PLAINS STATES TUESDAY
AFTERNOON WILL MOVE TO THE MISSISSIPPI VALLEY OVERNIGHT. PW VALUES
ACROSS UPPER MI WILL FALL TO 20 TO 35 PERCENT OF NORMAL...LOWEST E.
WITH PLENTY OF DRY AND COLD AIR OVERHEAD...EXPECT TEMPERATURES TO
QUICKLY FALL AFTER SUNSET. WILL CONTINUE TO GO TOWARD THE LOW
END OF GUIDANCE VALUES.
THE HIGH PRESSURE SYSTEM WILL SHIFT ACROSS THE OHIO VALLEY/CENTRAL
APPALACHIANS ON WEDNESDAY...AS LOW PRESSURE ORGANIZES OVER
WY/SD/NE/CO. EXPECT SIGNIFICANT WAA AS THE PRESSURE GRADIENT
INCREASES ACROSS MN AND W UPPER MI THROUGH THE DAY IN BETWEEN THE
EXITING HIGH AND NEARING LOW.
THE MAIN SYSTEM OF THE PERIOD STILL HAS SOME UNCERTAINTY WITH
IT...BUT IS MOVING TO A CONSENSUS OF 0.7-0.9IN OR MORE LIQUID
BETWEEN LATE WEDNESDAY AFTERNOON THROUGH THURSDAY NIGHT. LOOKS LIKE
ALL SNOW THROUGH AT LEAST 12Z THURSDAY. IN FACT...A GENERALLY COLDER
TREND LOOKS REALISTIC FOR THE ENTIRE SYSTEM...EQUATING TO MORE SNOW
AND HIGHER SLR VALUES. HAVE TRENDED BACK ON MIXED PRECIP IN THE
FCST AND HWO...AS EVEN THE 00Z GFS KEEPS ONLY SNOW FOR ALL BUT NEAR
MNM. CURRENTLY HAVE 5 TO NEARLY 12IN OF SNOW FCST FROM LATE
WEDNESDAY AFTERNOON THROUGH THURSDAY NIGHT. WINTER WEATHER
ADVISORIES WILL LIKELY BE NEEDED AS THE TIME NEARS...WITH THE
POTENTIAL FOR WARNINGS IF FCST TOTALS GET TO 6IN OR MORE IN 12HRS OR
10IN OR MORE IN 24HRS. IT IS A LONGER DURATION EVENT WHICH MAKES
HEADLINES DIFFICULT. AT THIS POINT...3-4 LOOKS LIKELY IN ANY 12HR
PERIOD...BUT WOULD NOT BE SURPRISED IF THE FCST JUMPS UP TO THIS
HIGHER RANGE AS FCST MODELS CONVERGE ON A SOLUTION EARLY THIS WEEK.
WHEN COMPARING THE 00Z RUNS...THE ECMWF CONTINUES TO BE ON THE SLOW
END OF MODEL SOLUTIONS. THE CANADIAN RUN BACKS UP THE ECMWF. THE GFS
CONTINUES TO BE A BIT FASTER...FOR EXAMPLE AT 06Z FRIDAY THE SFC LOW
OFF THE GFS IS OVER LOWER MI AND LAKE HURON...WHILE THE
ECMWF/CANADIAN LOW IS POSITIONED ACROSS S WI AND W IA.
AS FOR THE UPCOMING WEEKEND ZONAL FLOW WILL TAKE HOLD...WITH
TEMPERATURES WARMING BACK INTO THE MID-UPPER 30S ON SATURDAY AND
INTO THE 40S FOR SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 147 PM EDT MON MAR 24 2014
STEEP LOW TO MID LEVEL LAPSE RATES WILL SUPPORT CU/SC THROUGH THIS
AFTERNOON. WITH THE APPROACH OF A DISTURBANCE FROM THE NW IN THE
AFTN...SCT -SHSN WILL THEN LIKELY DEVELOP AT KIWD/KSAW WITH
POTENTIAL OF BRIEF MVFR VIS AT TIMES...ESPECIALLY AT KIWD.
COLD/STABILIZING FLOW OFF MOSTLY SNOW/ICE COVERED LAKE SUPERIOR WILL
PROBABLY PREVENT -SHSN FROM DEVELOPING AROUND KCMX...ALLOWING VFR
CONDITIONS TO PREVAIL THERE. HOWEVER...BY LATE TONIGHT INTO TUE
MORNING...THE COMBINATION OF LOW LEVEL CONV AND UPSLOPE FLOW WILL BE
ENOUGH TO SUPPORT MVFR CIGS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 415 PM EDT MON MAR 24 2014
A COLD FRONT WILL MOVE THROUGH THE NRN LAKES TONIGHT. BEHIND THE
FRONT...WINDS WILL SHIFT TO THE NORTHWEST AND INCREASE TO 15 TO 25
KT TONIGHT AND 20 TO 30 KTS ON TUESDAY...WITH THE HIGHEST GUSTS OVER
THE EASTERN HALF OF LAKE SUPERIOR. WINDS WILL QUICKLY DIMINISH
TUESDAY NIGHT AND WEDNESDAY AS ANOTHER HIGH PRESSURE RIDGE MOVES
OVER THE AREA. A LOW PRESSURE SYSTEM DEVELOPING IN THE CENTRAL
PLAINS ON WEDNESDAY NIGHT AND THURSDAY WILL MOVE THROUGH THE GREAT
LAKES REGION LATE THURSDAY NIGHT AND FRIDAY. WIND STRENGTH/DIRECTION
WILL DEPEND ON THE EXACT TRACK OF THE LOW...BUT AT THIS TIME NORTH
TO NORTHEAST WINDS OF 15 TO 25 KTS ARE EXPECTED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1230 PM CDT MON MAR 24 2014
.UPDATE...
ISSUED AT 1041 AM CDT MON MAR 24 2014
CLOUDS/FLURRIES ARE SLIDING ACROSS THE SWRN/SRN CWA AT THIS TIME.
THIS IS ALONG THE NRN EDGE OF AN AREA OF HIGHER 85/70H LAPSE RATES.
ELSEWHERE ABUNDANT SUNSHINE IS OCCURRING WITH VERY DRY AIR IN PLACE
WITH PWATS NEAR OR BELOW A TENTH OF AN INCH. APPROACHING BAND OF
CIRRUS OVER ONTARIO IS ASSOCIATED WITH A MID LVL TROF. A CORRELATING
SFC COLD FRONT IS WELL DEFINED IN THE 925 THETAE FIELDS ACROSS
CTRL ONTARIO INTO SASK. ONLY MINOR TEAKS MADE TO NDFD/ZFP TODAY AS
COLD FRONT MOVES INTO NRN CWA LATER THIS AFTN. GUSTY WINDS SHOULD
INCREASE AS NWRLY FLOW DEEPENS WITH MID LVL TROF PASSAGE. PRECIP
COVERAGE STILL LOOKS LIMITED INITIALLY DUE TO VERY DRY AIR HOWEVER
LATEST SNSQ PARAMETER TRENDS SUGGEST HIGHER PROB DEVELOPS FROM 21Z
OVER NRN MN ZONES TO SERN WISC ZONES BY 03Z.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY AFTERNOON)
ISSUED AT 345 AM CDT MON MAR 24 2014
MAIN CONCERNS IN THE SHORT TERM ARE CENTERED AROUND THE CHANCE FOR
SNOW SHOWERS ACROSS MOST OF THE NORTHLAND THIS AFTERNOON...WITH
LINGERING LIGHT SNOW POSSIBLE TONIGHT THROUGH TUESDAY AFTERNOON.
ATTENTION WAS ALSO ASSIGNED TO THE PERSISTENT COLD TEMPERATURES
AND BREEZY NW WINDS.
WEAK HIGH PRESSURE AT THE SFC CONTINUES TO INFLUENCE THE UPPER
MIDWEST THIS MORNING WITH THE RIDGE AXIS EXTENDING FROM THE CENTER
OF THE HIGH OVER ERN IA THROUGH MN INTO WRN NORTH DAKOTA. COLD NWLY
FLOW ALOFT REMAINS IN PLACE AND WILL HELP TRIGGER SNOW SHOWERS
OVER THE REGION THIS AFTERNOON. AN EMBEDDED S/W OVER THE DAKOTAS
THIS MORNING...WITH AN ASSOCIATED SFC INVERTED TROUGH AROUND SIOUX
CITY WILL MOVE E/SEWD TODAY. A SECOND FEATURE TO THE NORTH ALONG A
COLD FRONT WILL MOVE SWD INTO THE AREA TODAY AS WELL. THE
COMBINATION OF THESE TWO WAVES AND STEEPENING LOW LEVEL LAPSE
RATES WILL GENERATE SNOW SHOWERS ACROSS THE REGION. AMTS WILL
LIKELY NOT ADD UP TO MUCH...BUT SNOW SQUALL PARAMETER FROM THE
LATEST RUNS OF THE NAM AND RAP ARE BOTH AT LEVELS THIS AFTERNOON
THAT WOULD INDICATE POSSIBLE PERIODIC BURSTS OF MDT TO HVY SNOW.
LATEST RAP13 IS ALSO POINTING TOWARD AN AREA TO THE SOUTH ACROSS
CENTRAL MN AND NW WI WHERE STRONG UVV IN THE DGZ COULD ALSO LEAD
TO BRIEF LOCALIZED HVY SNOW WITH REDUCED VSBYS. THE COLD/DRY AIR
MASS WILL LIKELY INHIBIT ANY ACCUMULATION OVER AN INCH...AND KEEP
THE SNOW GENERALLY IN THE FORM OF LARGE DENDRITES.
THE COLD FRONT DROPPING IN FROM THE NORTH WILL ALSO TRIGGER SNOW
SHOWERS ACROSS THE NRN COUNTIES LATER THIS AFTERNOON AND ALLOW
LIGHT SNOW/FLURRIES TO LINGER OVER THE REGION INTO TUESDAY. HIGH
PRESSURE WILL BUILD IN FROM THE W/NW ON TUESDAY AND HELP LIMIT THE
COVERAGE OF SNOW SHOWERS...BUT SHOULD STILL HAVE ENOUGH CAA
OCCURRING THROUGH THE DAY TO WARRANT LOW CHC POPS.
AS THE HIGH PRESSURE BUILDS IN OVER THE NRN ROCKIES AND FRONT
RANGE IN ERN MONTANA TODAY A TIGHT SFC PRES GRADIENT WILL FORM
OVER THE NRN PLAINS AND UPPER MIDWEST. STEEP LOW LVL LAPSE RATES
WILL ALSO HELP MIX DOWN STRONGER WINDS ALOFT. EXPECT NW WINDS
SUSTAINED AROUND 15 MPH...AND GUSTS TO 25 MPH TODAY. WINDS REMAIN
BREEZY TONIGHT AND INCREASE AGAIN ON TUESDAY...SIMILAR TO TODAY.
AIR MASS TODAY WILL NOT BE AS COLD AS YESTERDAY...SO TEMPS WILL BE
ROUGHLY 5 DEG WARMER. THE ADDED CLOUD COVER TONIGHT WILL KEEP
TEMPS FROM FALLING TOO FAR BELOW ZERO. HOWEVER ON TUESDAY ANOTHER
SURGE OF ARCTIC AIR FROM THE NORTH WILL KEEP HIGHS IN THE
TEENS...A GOOD 15 TO 20 DEG BELOW AVERAGE.
.LONG TERM...(TUESDAY EVENING THROUGH SUNDAY)
ISSUED AT 345 AM CDT MON MAR 24 2014
THIS PERIOD WILL BE ACTIVE...WITH A SIGNIFICANT STORM POSSIBLE LATE
WEDNESDAY NIGHT INTO THURSDAY NIGHT.
THE PERIOD WILL START OUT RATHER QUIET WITH THE NORTHLAND BETWEEN
HIGH PRESSURE TO THE EAST AND A LOW TO THE WEST. IT WILL BE DRY AND
COLD TUESDAY NIGHT WITH LOW AROUND OR IN THE SINGLE DIGITS BELOW
ZERO.
INCREASING WAA AND A SHORTWAVE WILL LEAD TO A CHANCE FOR LIGHT SNOW
WEDNESDAY...WITH CHANCES GREATEST ACROSS FAR NORTHERN MINNESOTA.
LIGHT SNOW ACCUMULATIONS ARE EXPECTED WEDNESDAY...AND THE NORTH
SHORE COULD GET SEE SOME HIGHER AMOUNTS DUE TO ONSHORE FLOW WITH
COLD TEMPERATURES STILL IN PLACE.
DIFFERENCES AMONG THE MODELS START TO AMPLIFY WEDNESDAY NIGHT WITH
THE GFS/NAM FASTER MOVING A CENTRAL PLAINS LOW NORTHEAST. WE
FOLLOWED CLOSE TO THE SLOWER ECMWF WHICH HAS SUPPORT FROM THE GEM.
THE ECMWF DEVELOPS AN INVERTED TROUGH INTO NORTHEAST MINNESOTA FROM
THE LOW IN WESTERN KANSAS WEDNESDAY NIGHT...THEN THE SURFACE LOW
MOVES INTO IOWA ON THURSDAY AND TOWARD SOUTHERN LAKE MICHIGAN
THURSDAY NIGHT. SNOW SHOULD INCREASE IN COVERAGE AND INTENSITY LATE
WEDNESDAY NIGHT OVER THE EASTERN HALF OF THE NORTHLAND. THE ECMWF
DOES BRING SOME WARMER TEMPS INTO OUR SOUTHERN CWA WITH A MIX
POSSIBLE OVER SOUTHERN AREAS LATE WEDNESDAY NIGHT INTO THURSDAY.
TEMPS DO LOOK COOLER THAN PREVIOUS RUNS...AND WE HAVE A SNOW/SLEET
MIX GOING UNTIL THURSDAY AFTERNOON WHEN SOME RAIN COULD OCCUR FAR
SOUTH. WE INCREASED POPS QUITE A BIT WEDNESDAY NIGHT INTO THURSDAY
NIGHT OVER THE EASTERN HALF OF THE NORTHLAND. THE THREAT FOR
SIGNIFICANT SNOWFALL CONTINUES TO INCREASE OVER ABOUT THE EASTERN
HALF OF THE NORTHLAND. LOWERING STABILITY...INCREASING FGEN...AND
UPPER LEVEL DIVERGENCE FROM A COUPLED JET ARE ALL FORECAST OVER THE
NORTHLAND WEDNESDAY NIGHT INTO THURSDAY EVENING. MORE DETAILS WILL
BE ADDED AS WE PROGRESS THROUGH THE WEEK AND HOPEFULLY THE MODELS
WILL CONVERGE ON A SOLUTION.
THE LOW WILL MOVE OFF TO THE EAST FRIDAY...WITH SOME LIGHT SNOW
LINGERING OVER PORTIONS OF NORTHERN WISCONSIN. INCREASING WAA
SATURDAY INTO SUNDAY WILL BRING THE POTENTIAL FOR SOME LIGHT MIXED
PRECIPITATION. WE HAVE SOME LOW POPS OVER PORTIONS OF THE NORTHLAND.
THE ECMWF HAS BACKED OFF CONSIDERABLY ON ITS WARMING INTO NEXT
WEEKEND AND HAS A BAROCLINIC ZONE ACROSS THE REGION. TEMPERATURES
ARE FORECAST TO RISE FROM THE MID TWENTIES TO LOWER THIRTIES
WEDNESDAY TO THE UPPER THIRTIES TO MID FORTIES SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1230 PM CDT MON MAR 24 2014
A COLD FRONT WILL MOVE THROUGH NE MINNESOTA AND NW WISCONSIN THIS
AFTERNOON AND THIS EVENING. THERE SHOULD BE INCREASING MVFR AND
VFR CIGS IN THE 2 TO 4 KFT RANGE THIS AFTERNOON...AND THESE CIGS
COULD PRODUCE OCCASIONAL SNOW SHOWERS WHICH COULD RESULT IN MVFR
OR IFR VSBYS. THERE WILL ALSO BE INCREASING NW WINDS THIS
AFTERNOON...WITH MUCH OF THE REGION SEEING GUSTS AROUND 20 TO 25
KNOTS DURING THE LATE AFTERNOON AND EARLY EVENING.
I AM NOT AS CONFIDENT ABOUT CONDITIONS TONIGHT. THERE IS THE
POSSIBILITY THAT MVFR CIGS COULD LINGER THROUGH THE NIGHT...AND
MAYBE INTO TUESDAY MORNING. THE NW WINDS SHOULD BEGIN TO WEAKEN
LATE TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 24 0 17 0 / 20 20 10 0
INL 19 -7 15 -5 / 30 20 20 0
BRD 27 2 20 -1 / 20 20 0 0
HYR 26 2 18 -8 / 30 20 20 0
ASX 26 4 17 -2 / 20 20 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...CANNON
SHORT TERM...BJT
LONG TERM...MELDE
AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
110 PM CDT MON MAR 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 412 AM CDT MON MAR 24 2014
PER LATEST RADAR...AREA OF LIGHT SNOW OCCURRING THROUGH THE HEART OF
OUR CWA VERY EARLY THIS MORNING IS TRENDING TOWARD THE NORTH AND
EAST...AND PER LATEST RAP 13 ANALYSIS LOOKS TO BE ASSOCIATED WITH
FRONTOGENESIS LOCATED AROUND 800 MB. MODELS INDICATING THIS FRONTAL
FORCING TO SLIP TO THE EAST THROUGH THE MORNING HOURS...AND
ANTICIPATE THE OVERALL PRECIPITATION TREND TO FOLLOW SUIT WITH MOST
OF THE SNOW ENDING BY 15Z. VISIBILITIES WITH THE SNOW HAVE GENERALLY
BEEN REMAINING IN THE 2 TO 3 MILE RANGE...NOT ESPECIALLY HEAVY...SO
AM THINKING THAT ONLY A FEW TENTHS OF ADDITIONAL ACCUMULATION WILL
OCCUR WITH THE ACTIVITY...POSSIBLY UP TO AN INCH. AFTER THAT...DO
NOT THINK WE WILL SEE MUCH MORE ACTIVITY THROUGH THE REMAINDER OF
THE DAY...THOUGH HI RES MODELS INDICATE SOME POSSIBLE REDEVELOPMENT
IN OUR NORTH AND EAST DURING THE LATE AFTERNOON AND EARLY EVENING AS
ANOTHER SHORTWAVE/COLD FRONT DROP SOUTHWARD ACROSS THE AREA DURING
THAT TIME FRAME. WOULD BE SURPRISED THAT MUCH OF THIS WOULD ACTUALLY
ACCUMULATE...PROBABLY MORE IN THE FORM OF FLURRIES...THOUGH DID
INCLUDE SOME SLIGHT POPS OVER THAT AREA IN THE AFTERNOON AND
EVENING. TEMPERATURES WILL OF COURSE REMAIN BELOW NORMAL...WITH
HIGHS RUNNING MOSTLY IN THE 30S.
WILL SEE NORTHWESTERLY WINDS BEGIN TO INCREASE BY LATE AFTERNOON AND
REMAIN FAIRLY BREEZY THROUGH TONIGHT WITH THE COLD AIR ADVECTION
BEHIND THE FRONTAL PASSAGE. THIS WILL MODERATE TEMPERATURES SOMEWHAT
IN SPITE OF DECREASING CLOUDS...THOUGH STILL COLD WITH LOWS DROPPING
INTO THE TEENS OVERNIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 412 AM CDT MON MAR 24 2014
QUIET CONDITIONS CONTINUE THROUGH WEDNESDAY EVENING...WITH LOW LEVEL
TEMPERATURES GRADUALLY WARMING BACK TO ABOVE NORMAL LEVELS AHEAD OF
NEXT SYSTEM WHICH MOVES IN LATE WEDNESDAY NIGHT. SURFACE RIDGE MOVES
INTO WESTERN PARTS OF THE AREA TUESDAY...WITH MOSTLY SUNNY SKIES AND
DECREASING NORTHWEST WINDS THROUGH THE DAY. MINIMAL SNOWFALL EARLY
THIS MORNING EXPECTED TO HAVE LITTLE IMPACT BY TUESDAY...SO FAVORED
SLIGHTLY WARMER GUIDANCE NUMBERS FROM THE UPPER 20S IN SOUTHWEST MN
TO MID 30S THROUGH THE MISSOURI RIVER VALLEY. SHOULD SEE TEMPS DROP
OFF QUICKLY TUESDAY EVENING...THEN LEVEL OFF OR SLIGHTLY RECOVER IN
THE LATTER HALF OF THE NIGHT AS THE RIDGE AXIS SHIFTS EAST AND SOUTH
FLOW PICKS UP.
WEDNESDAY SHOULD BE ANOTHER MILD DAY...AS 925MB TEMPERATURES WARM
INTO THE 5-10C RANGE NORTHEAST...TO MID TEENS IN SOUTHWEST PARTS OF
THE CWA. AGAIN FAVORED WARMING A BIT MORE OVER PREVIOUS FORECAST...
WITH HIGHS FROM AROUND 50 ACROSS SOUTHWEST MN TO LOWER 60S IN THE
MISSOURI VALLEY. THIS FAIRLY CLOSE TO RAW MODEL CONSENSUS...WITH
NAM/GFS ON THE COOLER SIDE OF THE SPECTRUM...ECMWF NEAR THE MIDDLE
AND GEM THE WARMEST AMONG THE RAW MODEL NUMBERS.
MODELS CONTINUE TO SHOW WAVE MOVING ACROSS THE REGION WEDNESDAY NIGHT
INTO THURSDAY NIGHT...WITH GFS ON THE FAST SIDE BUT TRENDING TOWARD
SLOWER ECMWF/GEM TIMING. HAVE LEANED MORE TOWARD THIS SLOWER TIMING
FOR NOW...WHICH KEEPS MUCH OF THE AREA WARMER WEDNESDAY NIGHT WITH
PRECIP EXPECTED TO HOLD OFF UNTIL LATTER HALF OF THE NIGHT. THURSDAY
SHOULD BE THE WETTEST PERIOD FOR MOST AREAS...ESPECIALLY EAST WHERE
PRECIP HAS GREATER CHANCE OF LINGERING INTO THURSDAY NIGHT. PRECIP
TYPE WILL BE IN QUESTION...LARGELY DEPENDENT ON LOW LEVEL THERMAL
PROFILES WHICH ARE NOT ENTIRELY CLEAR CUT GIVEN DISCREPANCIES IN WAVE
TIMING. GENERALLY EXPECT MUCH OF THE AREA TO REMAIN LIQUID THROUGH
LATE WEDNESDAY NIGHT AND THURSDAY MORNING...WITH AREAS NORTHWEST OF
LAKE ANDES-MITCHELL-BROOKINGS MORE LIKELY TO SEE RAIN/SNOW MIX OR
TOTAL TRANSITION TO SNOW PRIOR TO 18Z THURSDAY. THREAT FOR SNOW WILL
EXPAND TO THE EAST AND SOUTH THROUGH THE AFTERNOON AS COLD ADVECTION
CONTINUES BEHIND THE DEPARTING COLD FRONT...THOUGH AMOUNTS CURRENTLY
EXPECTED TO REMAIN ON THE LIGHT SIDE AROUND AN INCH OR LESS OVER THE
WESTERN AND NORTHERN PARTS OF THE AREA.
WITH SLOWER TIMING...WILL CARRY CHANCE OF MAINLY LIGHT SNOW ALONG AND
EAST OF I-29 INTO THURSDAY NIGHT...FOLLOWED BY DRY AND INCREASINGLY
MILD CONDITIONS THROUGH NEXT WEEKEND AS MORE ZONAL FLOW PATTERN SETS
UP ACROSS THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 108 PM CDT MON MAR 24 2014
A BAND OF MVFR CEILINGS WILL CONTINUE TO WORK SOUTH ACROSS EASTERN
PARTS OF THE CWA THIS AFTERNOON. SOME PATCHY LIGHT SNOW AND
FLURRIES ARE LIKELY WITH THESE MVFR CEILINGS BUT ARE NOT EXPECTED
TO CREATE ANY PROBLEMS. AFTER 0Z TUESDAY THE REMAINDER OF THE TAF
PERIOD SHOULD BE VFR WITH A FEW WIND GUSTS AROUND 25 MPH FROM THE
NORTHWEST POSSIBLE.
&&
.FIRE WEATHER...
ISSUED AT 412 AM CDT MON MAR 24 2014
ABOVE NORMAL TEMPERATURES IN THE 50S AND LOWER 60S...ALONG WITH
INCREASING SOUTH WINDS WILL LEAD TO ELEVATED FIRE DANGER ACROSS PARTS
OF THE AREA ON WEDNESDAY. AT THIS TIME...MINIMUM HUMIDITY LEVELS ARE
EXPECTED TO HOLD IN 30-45 PERCENT RANGE IN AREAS WITH THE STRONGEST
WINDS...WHICH SHOULD LIMIT THREAT OF RED FLAG CONDITIONS. HOWEVER
WILL MONITOR THIS CLOSELY OVER THE NEXT COUPLE OF DAYS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JM
LONG TERM...JH
AVIATION...08
FIRE WEATHER...JH
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1225 PM CDT MON MAR 24 2014
.AVIATION...
ALREADY VFR CLL TO UTS AREA WITH SKIES BECOMING BKN/SCT AT 3000-5000
FEET. FURTHER SOUTH...LOWER BKN/OVC DECKS ARE HOLDING ON WITH BASES
AT 2000-3000 FEET. GRADUAL LIFTING/CLEARING TREND ACROSS THE AREA
FOR THE REST OF THE AFTERNOON AND OVERNIGHT HOURS WITH SPOTS CLOSEST
TO THE COAST EXPECTED TO BE THE LAST TO CLEAR OUT. NORTHEAST WINDS
5-10 KNOTS THIS AFTERNOON WILL WEAKEN...ONLY TO PICK UP AGAIN TOMORROW
MORNING (MAYBE A LITTLE MORE NNE THAN NE) IN A 9 TO 13 KNOT RANGE. AS
FOR -RA/-SHRA...EXPECT THE BULK OF ANY ACTIVITY TO BE OFF THE COAST.
WILL CONTINUE TO MONITOR FOR POSSIBLE INCLUSION IN LBX AND/OR GLS TAF
OVER THE NEXT SEVERAL HOURS. 42
&&
.PREV DISCUSSION... /ISSUED 1015 AM CDT MON MAR 24 2014/
UPDATE...
SEE DISCUSSION FOR MORNING UPDATE.
DISCUSSION...
LIGHT RAIN AND DRIZZLE HAVE STARTED TO COME TO AN END ACROSS THE
REGION THIS MORNING AS ISENTROPIC LIFT AND 850MB CONVERGENCE
CONTINUE TO WEAKEN. ANOTHER UPPER LEVEL DISTURBANCE IS FORECASTED
TO MOVE ACROSS THE WATERS THIS AFTERNOON WHICH COULD HELP THE RAIN
TO START BACK UP OVER THE WATERS. MOST OF THE AFTERNOON PRECIP
SHOULD STAY OVER THE GULF THOUGH. THE HRRR DEVELOPS THE PRECIP
OVER HARRIS COUNTY BUT IT APPEARS TO BE THE OUTLIER. ONLY MADE
MINOR TWEAKS TO GRIDS TO ACCOUNT FOR CURRENT TRENDS. NO UPDATE
REQUIRED AT THIS TIME. 23
PREV DISCUSSION... /ISSUED 439 AM CDT MON MAR 24 2014/
DISCUSSION...
SRN 1/3 OF THE REGION STILL ON THE NORTHERN PERIPHERY OF AN
ACTIVE WRLY FLOW AND MAY SEE SOME SCT LIGHT SHRA TODAY. BETTER
CHANCES SOUTH OF I-10 AND FURTHER OFFSHORE. REINFORCING HIGH PRES
MOVES IN OVERNIGHT AND SHOULD PROVIDE US WITH A NICE MOSTLY SUNNY
SPRING DAY ON TUE. THIS WILL BE SHORT LIVED HOWEVER.
TUE NIGHT-THURS EVENING LOOKS TO BE A PARTICULARLY ACTIVE WX
PERIOD. AS HIGH PRES MOVES OFF TO EAST...WINDS WILL QUICKLY VEER
BACK TO THE E THEN SE AND INCREASE IN SPEED. THIS WILL MAKE FOR
CHALLENGING CLEANUP EFFORTS THAT ARE ONGOING IN GALVESTON BAY &
GULF AS MARINE WX CONDITIONS WILL DETERIORATE. LONG FETCH OF GULF
MOISTURE SETS UP TO RETURN BACK INTO THE REGION DURING THE 2ND
HALF OF THE WORK WEEK.
TROF NOW SEEN ON W/V IMAGERY OFF THE CA COAST WILL MOVE ACROSS TX
WED AFTN/NIGHT. IN ADDITION TO TAPPING INTO TO THE INITIAL RETURN
OF INCOMING GULF MOISTURE THIS FEATURE WILL BRING ALONG SOME OF
ITS OWN. EXPECT A ROUND OF SHRA/TSRA TO DEVELOP OFF THE THE WEST
AND MOVE ACROSS SE TX THRU THE DAY & EVNG. PARAMETERS AREN`T
EXACTLY LINING UP PERFECTLY FOR GREAT CHANCES OF STRONG TO SEVERE
STORMS WITH WARM NOSE NOTED AROUND 6-9K FT, NEUTRAL JET STRUCTURE
AND LOW CHANCE OF SIGNIFICANT HEATING DUE TO CLOUDS. BUT STILL
WORTH KEEPING AN EYE ON THINGS THOUGH AS SOUNDINGS SHOW STEEP
LAPSE RATES FURTHER ALOFT AND STRONG 35-40KT LLVL WINDS CAN`T BE
IGNORED JUST YET.
ECMWF/GFS/NAM12 ALL PINGING A GOOD PART OF THE AREA WITH SOME
DECENT RAINS (BUT AT SLIGHTLY DIFFERENT TIME PERIODS) BETWEEN WED
NIGHT AND THURS AFTN. ALL 3 ARE IN ASSOCIATION WITH ARRIVAL OF A
DEEPER SLUG OF TROPICAL MOISTURE. NAM12 TRIGGER APPEARS TO KEY IN
UPON SPEED CONVERGENCE INTO A COASTAL TROF SITUATED JUST INLAND
WED NIGHT. GFS/ECMWF TRIGGER LOOKS TO BE AN EWD ADVANCING DRY LINE
THURS AFTN. NOT SURE WHICH ONE...IF ANY...TO GO WITH BUT WILL
CONTINUE HIGHER END CHC POPS THRU THE PERIOD. (FOR THOSE PLAYING
AT HOME...THE NAM12 & TX TECH WRF HAVE BEEN MODELS OF CHOICE
LATELY).
LEFT THE EXTENDED AS IS. IT`S BEEN GEARED TOWARD THE ECMWF SOLN
WHICH GOES WITH A WEAK FRONTAL PASSAGE FRI NIGHT. LOOKS LIKE
CANADIAN IS IN ITS CAMP AS WELL. 47
MARINE...
MODERATE/STRONG OFFSHORE FLOW WILL CONTINUE TO DECREASE TODAY AS THE
GRADIENT RELAXES BRIEFLY. HAVE KEPT SCEC/SCA FLAGS UP FOR THE COAST-
AL WATERS THROUGH MID MORNING GIVEN THE ONGOING TRENDS. THIS RESPITE
SHOULD COME TO AN END AS A REINFORCING COLD FRONT MOVES INTO THE RE-
GION TONIGHT. CAUTION FLAGS MAY NEEDED ONCE AGAIN TONIGHT/OVERNIGHT.
THESE MODERATE/STRONG WIND SPEEDS ARE EXPECTED TO PERSIST ON THROUGH
THE END OF THE WEEK...EVEN AS THE WIND DIRECTION BECOMES MORE S/SELY
LATE WEDS OR SO. THIS DEVELOPING PATTERN OF A FAIRLY DEEP AND STRONG
ONSHORE FETCH COULD PRODUCE SOME DECENT SWELLS/ELEVATED WAVE HEIGHTS
DURING THE LATTER PART OF THE WEEK. MODELS REMAIN A BIT IFFY ON PRO-
SPECTS OF ANOTHER FRONT LATE FRI/EARLY SAT...BUT HAVE KEPT FCST BENT
ON ECMWF FOR NOW. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 67 44 69 46 63 / 10 10 0 0 60
HOUSTON (IAH) 64 50 72 49 64 / 20 10 0 0 40
GALVESTON (GLS) 61 57 70 59 65 / 30 10 0 0 50
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH LATE TONIGHT FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...23
AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
335 PM CDT MON MAR 24 2014
.SHORT TERM...
TONIGHT...FORECAST CONFIDENCE MEDIUM
THERE IS WEAK LOW LEVEL ISENTROPIC LIFT AND WARM AIR ADVECTION
CURRENTLY OVER NORTHEAST IOWA AND WEST CENTRAL WI. THIS WEAK FORCING
IS RUNNING INTO VERY DRY LOW LEVEL AIR AS IT APPROACHES SOUTH
CENTRAL WI. THUS...EXPECTING LIGHT SNOW TO HOLD OFF OVER THE FAR
WESTERN FORECAST AREA THROUGH MOST OF THE AFTERNOON.
THE WRF-NMM AND RAP ARE A LITTLE MORE AGGRESSIVE WITH BRINGING IN
PRECIP THIS AFTERNOON...WHILE OTHER MODELS MAINTAIN A DRY FORECAST.
THE RAP EVEN SHOWS CONVECTIVE SNOW SHOWER POTENTIAL WITHIN THE WAA
AREA PER BUFKIT FORECAST SOUNDINGS. THE 17Z HRRR KEEPS MOST WAA
REFLECTIVITY SOUTH OF THE WI BORDER.
IT IS LOOKING MORE LIKELY THAT A BAND OF SNOW WILL DEVELOP JUST
AHEAD OF THE COLD FRONT. THIS IS ALREADY HAPPENING IN SOUTHEAST
MINNESOTA. THIS IS WHERE THERE IS DECENT OMEGA AND IT LANDS WITHIN
THE DENDRITE ZONE...ALONG WITH FRONTOGENESIS. I AM LESS CERTAIN
ABOUT HOW LONG THE SNOW WILL LAST. THE MODELS ARE PAINTING A LONGER-
DURATION QPF EVENT...BUT THE MORE LIKELY SCENARIO WOULD BE FOR A ONE
TO TWO HOUR MODERATE SNOWFALL JUST AHEAD OF THE FRONT...FOLLOWED BY
SEVERAL HOURS OF SCATTERED SNOW SHOWERS WITH THE STEEP LOW LEVEL
LAPSE RATES DUE TO STRONG COLD AIR ADVECTION BEHIND THE FRONT.
.TUESDAY...FORECAST CONFIDENCE HIGH
NORTHWEST WINDS WILL INCREASE AND BECOME GUSTY BEHIND THE COLD FRONT
TONIGHT...ESPECIALLY AFTER MIDNIGHT. A TIGHT SURFACE PRESSURE
GRADIENT...STEEP LOW LEVEL LAPSE RATES AND CYCLONIC FLOW ALOFT WILL
ALLOW FOR STRONG NORTHWEST WINDS TO CONTINUE ALL DAY TUESDAY AS
WELL. FREQUENT GUSTS TO 25 MPH ARE LIKELY. PLAN ON OVERCAST TO
BROKEN CLOUDS FOR MOST OF THE DAY...ESPECIALLY IN SOUTHEAST
WISCONSIN. FLURRIES WILL BE POSSIBLE THROUGH THE MORNING DUE TO
ANOTHER WEAK UPPER LEVEL SHORTWAVE DROPPING THROUGH.
TEMPERATURES WILL HOLD FAIRLY STEADY THROUGH THE DAY IN THE LOWER
20S WITH THE CORE OF 925MB TEMPS OF AROUND -14C SITTING OVER CENTRAL
WI.
TUESDAY NIGHT THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM
A SFC RIDGE WILL SLOWLY MOVE EWD ACROSS THE REGION TUE NT. GOOD
RADIATIONAL COOLING AND COLD TEMPS ARE EXPECTED. CYCLOGENESIS OVER
THE THE CENTRAL PLAINS WILL LEAD TO SLY WINDS AND WARM ADVECTION
AS FAR EAST AS WI BEGINNING ON WED. SKIES WILL BECOME CLOUDY DUE
TO FAIRLY STRONG MID LEVEL WARM ADVECTION BUT LOW LEVELS APPEAR TO
BE TOO DRY FOR PCPN. TEMPS WILL WARM INTO THE 30S AND THEN HOLD
STEADY IN THE 30S WED NT.
A 50-60 KNOT LOW LEVEL JET WILL THEN SHIFT TOWARD THE REGION FOR
WED NT INTO THU NT. BEST LIFT COINCIDED WITH MOISTURE WILL BE FOR
THU AND THU NT AS LOW PRESSURE AREA AND ASSOCIATED SHORTWAVE
TROUGH MOVE ACROSS SRN WI. CHANCE POPS FOR RAIN/SNOW WED NT AND
THEN LIKELY RAIN FOR THU/THU NT WITH LINGERING POPS ON FRI FOR
RAIN/SNOW.
.LONG TERM...
SATURDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM
HIGH PRESSURE TO PREVAIL ON SAT BUT WILL MOVE EWD BY SAT NT WITH
SWLY WINDS AND WARM ADVECTION AS AN UPPER RIDGE APPROACHES FROM
THE PLAINS. SWLY WINDS AND WARM ADVECTION TO CONTINUE INTO SUN
WITH 1000-500 MB THICKNESSES OF 552-558 DM. HIGH TEMPS LIKELY IN
THE 60S IF THIS PATTERN HOLDS. A DEVELOPING LOW OVER THE PLAINS
WILL THEN TRACK ACROSS WI ON MON WITH CONTINUED MILD TEMPS BUT
RAIN.
&&
.AVIATION/00Z TAFS/...
VFR CONDITIONS WILL CONTINUE THROUGH THE AFTERNOON ACROSS SOUTHERN
WI. THERE IS AN OUTSIDE CHANCE FOR LIGHT SNOW TO DEVELOP LATE THIS
AFTERNOON ACROSS SOUTH CENTRAL WI AND POSSIBLY NEAR FOND DU LAC AND
SHEBOYGAN...BUT OVERCOMING THE LOW LEVEL DRY AIR IN PLACE WILL MOST
LIKELY KEEP ANY PRECIP ALOFT FROM REACHING THE GROUND.
THE BETTER CHANCE FOR A BAND OF MODERATE SNOW WILL BE JUST AHEAD OF
A COLD FRONT THAT WILL MOVE SOUTHEAST ACROSS SOUTHERN WI THIS
EVENING. GUSTY NORTHWEST WINDS ARE EXPECTED ALONG AND BEHIND THIS
COLD FRONT...ALONG WITH SCATTERED LIGHT SNOW SHOWERS OR FLURRIES
THROUGH THE REST OF THE NIGHT AND THROUGH TUESDAY MORNING. MVFR
CIGS/VSBYS EXPECTED WITH THE SNOW...WITH AROUND A HALF INCH OF
ACCUMULATION. LOOK FOR STRONG AND GUSTY NORTHWEST WINDS BEHIND THE
FRONT OVERNIGHT THROUGH TUESDAY.
&&
.MARINE...
A SMALL CRAFT ADVISORY IS IN EFFECT LATE THIS EVENING THROUGH EARLY
WEDNESDAY EVENING FOR NORTHWEST WINDS THAT WILL GUST BETWEEN 25 AND
30 KNOTS BEHIND A COLD FRONT MOVING THROUGH THE GREAT LAKES REGION.
THE OFFSHORE FETCH WILL KEEP WAVES IN THE 2 TO 4 FOOT RANGE WITH THE
HIGHER WAVES TOWARD OPEN WATER.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 1 AM TO 10 PM CDT TUESDAY FOR
LMZ643>646.
&&
$$
TONIGHT/TUESDAY AND AVIATION/MARINE...MRC
TUESDAY NIGHT THROUGH MONDAY...GEHRING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
319 PM CDT MON MAR 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 318 PM CDT MON MAR 24 2014
LATEST WATER VAPOR SATELLITE IMAGERY INDICATING SEVERAL SHORTWAVE
TROUGHS EMBEDDED IN NORTHERLY FLOW ALOFT OVER THE NORTHERN PLAINS
AND CENTRAL CANADA. LATEST MOSAIC RADAR SHOWS NUMEROUS SNOW
SHOWERS ACROSS FORECAST AREA BACK INTO CENTRAL MINNESOTA. THIS IS
IN RESPONSE TO STEEP LAPSE RATE UP TO 750MB PER LATEST RAP BUFKIT
SOUNDINGS.
TONIGHT...ANOTHER IMPULSE EMBEDDED IN THE NORTHERLY FLOW ALOFT
WILL MOVE OVER THE FORECAST AREA AND GREAT LAKES REGION. THE
24.12Z GFS/NAM AND 24.18Z BUFKIT SOUNDINGS SUGGEST STEEP LAPSE
RATES UP TO 850MB...500-300MB POTENTIAL VORTICITY ADVECTION AND
FORCING ABOVE 700MB IN ASSOCIATION WITH THE IMPULSE. THIS WILL
CONTINUE THE ISOLATED TO SCATTERED SNOW SHOWERS OVER FORECAST
AREA TO AROUND 09Z TUESDAY. HAVE INTRODUCE THIS TREND INTO THE
FORECAST.
BEHIND SHORTWAVE TROUGH...COLDER AIR WILL FILTER INTO THE AREA
TUESDAY...WITH 925MB TEMPERATURES FALLING INTO THE MINUS TEENS
DEGREES CELSIUS BY 18Z TUESDAY. TEMPERATURES WILL BE WELL BELOW
NORMAL AND HIGH TEMPERATURES EXPECTED TO CLIMB INTO THE TEENS TO
MIDDLE 20S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 318 PM CDT MON MAR 24 2014
FOCUS TURNS TO WEDNESDAY INTO THURSDAY NIGHT...AS NEXT SYSTEM
AFFECTS THE UPPER MIDWEST AND GREAT LAKES REGION. THE 24.12Z NAM
AND GFS CONTINUE TO BE THE MOST PROGRESSIVE AND FARTHER NORTH
PLACEMENT WITH THIS SYSTEM COMPARED TO THE 24.12Z ECMWF AND GEM.
THE 24.12Z MODELS ARE IN AGREEMENT DECENT WARM AIR ADVECTS INTO
THE AREA OUT AHEAD OF THE SYSTEM AND WRAPS INTO THE SYSTEM. THIS
WOULD ALLOW FOR MUCH OF THE PRECIPITATION TO FALL AS RAIN ACROSS
THE FORECAST AREA WEDNESDAY NIGHT INTO THURSDAY. THIS IS EVIDENT
WITH THE 24.12Z GFS/NAM BUFKIT SOUNDINGS SHOWING TEMPERATURES
ABOVE ZERO UP TO 850MB ACROSS MUCH OF THE FORECAST AREA AFTER 06Z
THURSDAY INTO THURSDAY AFTERNOON. THE 24.12Z MODELS INDICATE
SURFACE FRONT PASSAGE LATE THURSDAY AFTERNOON INTO THURSDAY NIGHT
ACROSS FORECAST AREA. THE PRECIPITATION SHOULD TRANSITION TO ALL
SNOW FROM WEST TO EAST ACROSS FORECAST AREA THURSDAY EVENING INTO
THURSDAY NIGHT. HOWEVER...WITH INCONSISTENCIES OF TIMING AND
PLACEMENT OF SYSTEM BY ALL THE MODELS WEDNESDAY NIGHT INTO
THURSDAY NIGHT...CONFIDENCE IN FORECAST AT THIS TIME PERIOD IS
LOW.
FRIDAY INTO SUNDAY MAIN FORECAST CONCERNS ARE TEMPERATURES ACROSS
THE FORECAST AREA. THE 24.12Z GFS/ECMWF BOTH ARE IN AGREEMENT IN
BREAKING DOWN UPPER LEVEL TROUGH OVER THE GREAT LAKES REGION AND
BUILDING SHORTWAVE RIDGE OVER THE NORTHERN PLAINS AND UPPER
MIDWEST THIS WEEKEND. THE MODELS SUGGEST 925MB TEMPERATURES
WARMING TO AROUND PLUS 10 DEGREES CELSIUS BY 00Z SUNDAY OVER
FORECAST AREA. THIS SHOULD ALLOW TEMPERATURES TO BE NEAR OR ABOVE
NORMAL SUNDAY. THEN...THE 14.12Z GFS/ECMWF BEGIN TO DIVERGE EARLY
NEXT WEEK WITH SHORTWAVE TROUGH EMBEDDED IN WEST TO EAST ZONAL
FLOW ALOFT. THE 24.12Z ECMWF MUCH MORE PROGRESSIVE AND STRONGER
WITH SHORTWAVE TROUGH AND INDICATES PRECIPITATION TO OVERSPREAD
THE FORECAST AREA MONDAY. THE 24.12Z GFS IS SLIGHTLY SLOWER AND
WEAKER WITH SHORTWAVE TROUGH AND DELAYS ANY PRECIPITATION INTO THE
FORECAST AREA BY 18Z MONDAY. AT THIS TIME...WILL INTRODUCE PRECIPITATION
CHANCES ACROSS FORECAST AREA SUNDAY NIGHT AND MONDAY.
PRECIPITATION SHOULD REMAIN AS ALL RAIN AS TEMPERATURES REMAIN
WELL ABOVE ZERO DEGREES CELSIUS IN THE NEAR SURFACE BOUNDARY LAYER
TO 800MB PER BUFKIT SOUNDINGS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1234 PM CDT MON MAR 24 2014
AS OF 17Z...SURFACE COLD FRONT LIES ALONG A KFSD...KMPX...KDLH LINE
AND MAIN AVIATION CONCERN IS ON CONVECTIVE SNOW SHOWERS TO IMPACT
THE TERMINALS THIS AFTERNOON. THE SNOW SHOWERS WILL BRING IFR
VISIBILITIES AND MAINLY MVFR CEILINGS TO KRST THROUGH LATE THIS
AFTERNOON...AND THEN AS THE COLD FRONT PASSES STRONG NORTHWEST WINDS
DEVELOP IN ITS WAKE. HAVE ADDED GUSTS UP TO 25 KTS AT KRST...AS
UPSTREAM OBSERVATIONS ARE 20 TO 25 KTS. AT KLSE...EXPECTING MAINLY
MVFR IMPACTS BUT COULD NOT RULE A BRIEF PERIOD OF IFR VISIBILITY IN
ANY PERKIER SNOW SHOWER. A LOT OF THE SNOW SHOWERS ARE DIURNALLY
DRIVEN AND SHOULD SUBSIDE AFTER SUNSET...BUT WITH UPPER LEVEL WAVE
YET TO ROTATE THROUGH...COULD STILL SEE SOME LIGHT ACTIVITY CONTINUE
OVERNIGHT. THIS IS MAINLY DUE TO THE STEEP LOW LEVEL LAPSE RATES AND
THE AFOREMENTIONED SHORTWAVE...SO MAY NEED TO PREVAIL SNOW SHOWERS
INSTEAD OF VICINITY COVERAGE. BROKEN CLOUD DECK WILL LIKELY REMAIN
IN PLACE THROUGH THE PERIOD...POSSIBLY SCATTERING OUT AROUND 12Z
BEFORE FILLING BACK IN LATE MORNING.
&&
.HYDROLOGY...
ISSUED AT 318 PM CDT MON MAR 24 2014
COLDER AIR IS HELPING WITH SNOW MELT AND ASSOCIATED RUNOFF INTO
AREA RIVERS AND STREAMS. WARMER TEMPERATURES ARE EXPECTED
WEDNESDAY INTO THURSDAY...AND THE THREAT FOR PRECIPITATION. DURING
THIS TIME PERIOD WILL HAVE TO MONITOR THE RIVER LEVELS CLOSELY
FOR RISES AND POSSIBLE FLOODING IF ENOUGH RAIN FALLS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...ZT
HYDROLOGY...DTJ