Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/22/16
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
359 PM EDT WED APR 20 2016
.SYNOPSIS...
HIGH PRESSURE OVER THE REGION, WILL MOVE OFF THE COAST ON THURSDAY.
LOW PRESSURE OVER THE CENTRAL PORTION OF THE NATION WILL MOVE
NORTHEASTWARD INTO EASTERN CANADA BY FRIDAY, AND ITS ASSOCIATED
COLD FRONT WILL MOVE THROUGH OUR REGION FRIDAY NIGHT. HIGH
PRESSURE WILL MOVE BACK INTO THE AREA FOR THE WEEKEND, WITH LOW
PRESSURE IMPACTING THE AREA AROUND TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
REST OF THIS AFTERNOON: MAX TEMPS NEARING 70. ITS BEEN A BEAUTIFUL
DAY. A WIND SHIFT TO SOUTHEAST WILL BE NEARING THE I95 CORRIDOR BY
6 OR 7 PM WITH DEWPOINTS RISING. HRRR SEEMS TO HAVE A GOOD HANDLE.
TONIGHT...ISSUED A FROST ADVISORY IN THE MOST FAVORED AREAS FROM
THE FORECAST WHERE MINS OF LESS THAN OR EQUAL TO 35 ARE ANTICIPATED.
ITS POSSIBLE THAT THERE MAY NEED TO BE A SMALL AREAL EXPANSION FOR
THIS SHORT DURATION FROST POTENTIAL, ESPECIALLY SOMERSET COUNTY,
THIS MORNINGS MINS WERE 28F IN WALPACK OF NW NJ AND MANY 30-36F
LOWS FROM NORTHERN CAPE MAY COUNTY NORTH THROUGH THE PINEBARRENS
REGION ON UP INTO NW NJ. NEARLY CALM WIND WITH MOSTLY CLEAR SKY (A
BIT OF CIRRUS TOWARD DAWN).
THIS PART OF THE FORECAST IS A 50 50 BLEND OF THE 12Z/20 GFS/NAM
GUIDANCE THEN COOLED 2-4F IN THE COUNTRYSIDE THROUGH 11Z THURSDAY
PER EXPECTED NEARLY IDEAL RADIATIONAL COOLING CONDITIONS BUT ALSO
REFLECTS THE VERY DRY AIR BOUNDARY LAYER, DESPITE ANY SHALLOW SFC
DEWPOINT RISE ASSOCIATED WITH THE SE SEA BREEZE REACHING THE POCONOS
AROUND 11 PM.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
THURSDAY...A MOSTLY SUNNY RAPIDLY WARMING START WITH GUSTY SW WINDS
15-20 MPH DEVELOPING LATE MORNING. INCREASING MID AND LATE
AFTERNOON CLOUD COVER AHEAD OF A WEAK INSTABILITY BURST THAT COULD
SPREAD SPRINKLES INTO NE PA BY 6PM. FIRE WEATHER IS THE MAIN
CONCERN THURSDAY AND WITH SOME UNCERTAINTY AS DISCUSSED IN THE
FIRE WEATHER SECTION. WIND GUSTS MAY APPROACH 25 MPH DURING THE
AFTERNOON, ESPECIALLY NORTH OF PHILADELPHIA.
THIS PART OF THE FCST WAS MOSTLY THE 12Z/20 GFS WARMER TEMP GUIDANCE,
THE DRIER NAM GUIDANCE AND A BLEND OF THE NAM/GFS WINDS AND SKYCOVER.
CONFIDENCE ON TEMPS REACHING OR EXCEEDING THESE VALUES IS HIGH. I
COULD SEE TEMPS 2-3F WARMER THAN CURRENTLY FCST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
THE PERSISTENT AREA OF HIGH PRES WILL BE OFF THE COAST AND MOVG
AWAY FROM THE AREA AT THE START OF THE PD.
LOW PRES NR THE GRTLKS WILL MOVE NEWD INTO ERN CANADA ON FRI. ITS
ATTENDANT CDFNT WILL MOVE THRU THE REGION FRI NIGHT. PRECIP CHCS
WILL INCREASE DURG THE DAY ON FRI WITH THE HIGHEST CHCS FRI ERLY
FRI NIGHT WITH THE CFP. THE MDL GUID DIFFERS SLIGHTLY, WITH THE
GFS FASTER THAN THE ECMWF. THE NAM/WRF SUPPORTS THE SLOWER TIMING.
WPC GUID BACKS THE FASTER GFS. IF THE FASTER TIMING IS CORRECT,
THE PRECIP WOULD END LATE FRI NIGHT. IF THE SLOWER TIMING IS
CORRECT, THE PRECIP WILL END DURG SAT MRNG. THE ECMWF IS OFTEN
SLOWER WITH CFP, BUT SINCE IT HAS SUPPORT FROM OTHER MDLS, HAVE
LEFT SOME LOW POPS IN FOR SAT MRNG.
HIGH PRES BUILDS BACK IN FOR SAT INTO SUN, SO ANOTHER NICE WEEKEND
IS IN STORE.
THEN, A STRONG AREA OF LOW PRES WILL MOVE ACRS THE NCNTL PLAINS.
ITS WMFNT WILL EXTEND EWD ACRS THE GRTLKS INTO NEW ENG OR NRN MID
ATLC. THE ECMWF IS A BIT FURTHER S THAN THE GFS WITH THIS FRONT.
IF THE EC IS CORRECT, IT WOULD POTENTIALLY SUPPORT DOME LIGHT QPF
OVER NRN AREAS LATE SUN NIGHT OR MON MRNG, BUT THE EC IS CLEARLY
THE OUTLIER HERE. ALL THE OTHER MDLS HAVE A MUCH MORE NLY POSN OF
THIS BNDRY.
THE LOW MOVES FURTHER E MONDAY NIGHT TO A POSN SOMEWHERE OVER
PA/NY AND PRECIP CHCS WILL INCREASE, BEFORE THE LOW MOVES AWAY ON
TUE, THE CDFNT CROSSES THE REGION AND POPS DECLINE ONCE AGAIN.
TEMPS ARE EXPECTED TO BE AOA NRML THRU THE PD.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
REST OF TODAY...VFR CLEAR. LIGHT VARIABLE WIND TRENDING SOUTHEAST
TO SOUTH LATE IN THE DAY. THE COASTAL SEABREEZE WILL BE MOVING
WESTWARD- INLAND THIS AFTERNOON WITH THOSE SEA BREEZES HAVING A
FEW GUSTS TO 18-21 KT. THIS WIND SHIFT COULD REACH PHL LATE
AFTERNOON OR EARLY EVENING AND ATTEMPTED TIMING IS IN THE TAFS.
TONIGHT...VFR CLEAR THEN PATCHY AC/CIRRUS TOWARD 10Z/21. WIND
BECOMING NEARLY CALM LATER THIS EVENING THEN LIGHT SOUTHERLY
TOWARD MORNING.
THURSDAY...VFR SCT-BKN CLOUDS AOA 12000 FT DURING THE MORNING WITH
MULTI LAYERS DEVELOPING BY 21Z AOA 5000 FT. S-SW WIND THURSDAY
WITH MIDDAY-AFTERNOON GUSTS AROUND 20 KT. ABOVE AVERAGE
CONFIDENCE.
OUTLOOK...
THU NIGHT. VFR WITH SOME MVFR/IFR PSBL IN SHRA MAINLY N AND W. LOW
TO MDT CONFIDENCE.
FRI...MVFR/IFR PSBL IN SHRA AND TSRA AHEAD OF CFP. STILL SOME
DIFFS WITH TIMING OF CDFNT. MDT CONFIDENCE.
FRI NIGHT...CFP AND WSHFT. MVFR/IFR PSBL ERLY...THEN IMPROVING TO
VFR LATE. HIGH CONFIDENCE.
SAT THRU SUN...VFR. HIGH PRES. HIGH CONFIDENCE.
MON...VFR ERLY...LOWERING CONDS LATE AS NEXT SYS APPROACHES. MDT
CONFIDENCE.
&&
.MARINE...
NO MARINE HEADLINES ANTICIPATED THROUGH MOST OF THURSDAY.
STILL A DOMINANT EASTERLY SWELL OF 2-3 FT AND 8-10 SECONDS ON THE
ATLANTIC WATERS...A RESIDUAL FROM LAST WEEKEND.
A FEW ONSHORE GUSTS NEAR OR JUST ABOVE 20 KT ARE LIKELY INTO THIS
EVENING, ESPECIALLY DELAWARE BAY WHERE ISOLATED GUSTS TO 24 KT ARE
POSSIBLE. WIND TURNS LIGHT SOUTH LATER TONIGHT THEN GUSTY S-SW 20
KT THURSDAY AFTERNOON.
OUTLOOK...
THU NIGHT THRU FRI...SLY WILL BE PRESENT AND WE WILL PROB BE
LOOKING AT MARGINAL SCA CONDS BY FRI. WE MAY BE JUST UNDER SCA
CONDS THU NIGHT.
FRI NIGHT...WIND SHIFTS TO W THEN NW BEHIND CFP AND DECREASE.
SEAS DECREASE AS WELL. NO MARINE HEADLINES EXPECTED.
SAT THRU SUN...NO MARINE HEADLINES ANTICIPATED.
MON...SLY FLOW INCREASES IN ADVANCE OF THE NEXT LOW PRES SYS AND
SEAS RESPOND IN KIND. SCA FLAGS MAY BE NEEDED BY THE END OF THE
PD.
&&
.FIRE WEATHER...
FIRE WEATHER WATCH IN EFFECT: IF CONDITIONS ARE FORECAST THE SAME
OR WORSE AT 330 AM THURSDAY, OUR PARTNERS HAVE GIVEN THE GO AHEAD
TO CONVERT TO A WARNING. THERE IS STILL AN ELEMENT OF DOUBT REGARDING
THE WIND ELEMENT AND THE SOUTHWESTERN EXTENT OF THE RH BELOW 30 PERCENT.
WE THINK MODEL GUIDANCE IS TOO MOIST TOO SOON. WE WONT KNOW FOR SURE
UNTIL 15Z THURSDAY BUT THE VERY LOW DEWPOINTS IN THE WESTERN PART
OF VIRGINIA ARE A SIGN OF THE DRY ALOFT THAT STILL CAN MIX DOWN
TOMORROW ON THE GUSTY SW FLOW.
&&
.EQUIPMENT...
BUOY 44009 (DE BAY BUOY LOCATED 26 NM SOUTHEAST OF CAPE MAY NJ) IS
SLATED FOR RESTORATION OF WIND INFORMATION AROUND JULY 5, 2016.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
AFTERNOON FOR PAZ054-055-060>062-071-103>106.
NJ...FROST ADVISORY FROM 3 AM TO 8 AM EDT THURSDAY FOR NJZ001-
007>009-020-022-027.
FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
AFTERNOON FOR NJZ001-007>010-012-013-015-017>020-027.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...NIERENBERG
NEAR TERM...DRAG 4P
SHORT TERM...DRAG 4P
LONG TERM...NIERENBERG
AVIATION...DRAG/NIERENBERG 4P
MARINE...DRAG/NIERENBERG 4P
FIRE WEATHER...4P
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
335 PM EDT WED APR 20 2016
.SYNOPSIS...
HIGH PRESSURE OVER THE REGION, WILL MOVE OFF THE COAST ON
THURSDAY. LOW PRESSURE OVER THE CENTRAL PORTION OF THE NATION WILL
MOVE NORTHEASTWARD INTO EASTERN CANADA BY FRIDAY, AND ITS
ASSOCIATED COLD FRONT WILL MOVE THROUGH OUR REGION FRIDAY NIGHT. HIGH
PRESSURE WILL MOVE BACK INTO THE AREA FOR THE WEEKEND, WITH LOW
PRESSURE IMPACTING THE AREA AROUND TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
2PM UPDATE: TEMPS MAY MAX AT 69F AROUND 430PM. BRILLIANT SUNSHINE.
WINDS HAVE DIMINISHED PER HRRR EXCEPT AS PER HRRR JUST BEHIND THE
SEABREEZE. RH THIS AFTN DOWN TO 15 PCT.
TONIGHT...AM A LITTLE CONCERNED ABOUT FROST POTENTIAL AND MAY
ISSUE A FROST ADVY FOR PORTION OF NJ IN THE 330 PM FCST. THIS
MORNINGS MINS WERE 28F IN WALPACK OF NW NJ AND MANY 30-36F LOWS
FROM NORTHERN CAPE MAY COUNTY NORTH THROUGH THE PINEBARRENS REGION
ON UP INTO NW NJ. NEARLY CALM WIND WITH MOSTLY CLEAR SKY (A BIT
OF CIRRUS TOWARD DAWN). PROPOSED FROST ADVY WOULD BE INTERIOR
OCEAN SE BURLINGTON, INTERIOR ATLC AS WELL AS SUSSEX, WARREN,
MORRIS AND NORTHAMPTON COUNTIES.
THIS PART OF THE FORECAST IS A 50 50 BLEND OF THE 12Z/20 GFS/NAM
GUIDANCE THEN COOLED 2-4F IN THE COUNTRYSIDE THROUGH 11Z THURSDAY
PER EXPECTED NEARLY IDEAL RADIATIONAL COOLING CONDITIONS BUT ALSO
REFLECTS THE MUCH LOWER THAN FCST DEWPOINTS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
THURSDAY...A SUNNY RAPIDLY WARMING START WITH GUSTY SW WINDS 15-20
MPH DEVELOPING LATE MORNING. INCREASING MID AND LATE AFTERNOON
CLOUD COVER AHEAD OF A WEAK INSTABILITY BURST THAT COULD SPREAD
SPRINKLES INTO NE PA BY 6PM. FIRE WEATHER IS THE MAIN CONCERN
THURSDAY AND WITH SOME UNCERTAINTY AS DISCUSSED IN THE FIRE WEATHER
SECTION. WIND GUSTS MAY APPROACH 25 MPH DURING THE AFTERNOON,
ESPECIALLY NORTH OF PHILADELPHIA.
THIS PART OF THE FCST WAS MOSTLY THE 12Z/20 GFS WARMER TEMP GUIDANCE,
THE DRIER NAM GUIDANCE AND A BLEND OF THE NAM/GFS WINDS AND SKYCOVER.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE PERSISTENT AREA OF HIGH PRES WILL BE OFF THE COAST AND MOVG
AWAY FROM THE AREA AT THE START OF THE PD.
LOW PRES NR THE GRTLKS WILL MOVE NEWD INTO ERN CANADA ON FRI. ITS
ATTENDANT CDFNT WILL MOVE THRU THE REGION FRI NIGHT. PRECIP CHCS
WILL INCREASE DURG THE DAY ON FRI WITH THE HIGHEST CHCS FRI ERLY
FRI NIGHT WITH THE CFP. THE MDL GUID DIFFERS SLIGHTLY, WITH THE
GFS FASTER THAN THE ECMWF. THE NAM/WRF SUPPORTS THE SLOWER TIMING.
WPC GUID BACKS THE FASTER GFS. IF THE FASTER TIMING IS CORRECT,
THE PRECIP WOULD END LATE FRI NIGHT. IF THE SLOWER TIMING IS
CORRECT, THE PRECIP WILL END DURG SAT MRNG. THE ECMWF IS OFTEN
SLOWER WITH CFP, BUT SINCE IT HAS SUPPORT FROM OTHER MDLS, HAVE
LEFT SOME LOW POPS IN FOR SAT MRNG.
HIGH PRES BUILDS BACK IN FOR SAT INTO SUN, SO ANOTHER NICE WEEKEND
IS IN STORE.
THEN, A STRONG AREA OF LOW PRES WILL MOVE ACRS THE NCNTL PLAINS.
ITS WMFNT WILL EXTEND EWD ACRS THE GRTLKS INTO NEW ENG OR NRN MID
ATLC. THE ECMWF IS A BIT FURTHER S THAN THE GFS WITH THIS FRONT.
IF THE EC IS CORRECT, IT WOULD POTENTIALLY SUPPORT DOME LIGHT QPF
OVER NRN AREAS LATE SUN NIGHT OR MON MRNG, BUT THE EC IS CLEARLY
THE OUTLIER HERE. ALL THE OTHER MDLS HAVE A MUCH MORE NLY POSN OF
THIS BNDRY.
THE LOW MOVES FURTHER E MONDAY NIGHT TO A POSN SOMEWHERE OVER
PA/NY AND PRECIP CHCS WILL INCREASE, BEFORE THE LOW MOVES AWAY ON
TUE, THE CDFNT CROSSES THE REGION AND POPS DECLINE ONCE AGAIN.
TEMPS ARE EXPECTED TO BE AOA NRML THRU THE PD.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
REST OF TODAY...VFR CLEAR. LIGHT VARIABLE WIND TRENDING SOUTHEAST
TO SOUTH LATE IN THE DAY. THE COASTAL SEABREEZE WILL BE MOVING
WESTWARD- INLAND THIS AFTERNOON WITH THOSE SEA BREEZES HAVING A
FEW GUSTS TO 18-21 KT. THIS WIND SHIFT COULD REACH PHL LATE
AFTERNOON OR EARLY EVENING AND ATTEMPTED TIMING IS IN THE 18Z TAFS.
TONIGHT...VFR CLEAR THEN PATCHY AC/CIRRUS TOWARD 10Z/21. WIND
BECOMING NEARLY CALM LATER THIS EVENING THEN LIGHT SOUTHERLY
TOWARD MORNING.
THURSDAY...VFR SCT-BKN CLOUDS AOA 12000 FT DURING THE MORNING WITH
MULTI LAYERS DEVELOPING BY 21Z AOA 5000 FT. S-SW WIND THURSDAY
WITH MIDDAY-AFTERNOON GUSTS AROUND 20 KT.
OUTLOOK...
THU NIGHT. VFR WITH SOME MVFR/IFR PSBL IN SHRA MAINLY N AND W. LOW
TO MDT CONFIDENCE.
FRI...MVFR/IFR PSBL IN SHRA AND TSRA AHEAD OF CFP. STILL SOME
DIFFS WITH TIMING OF CDFNT. MDT CONFIDENCE.
FRI NIGHT...CFP AND WSHFT. MVFR/IFR PSBL ERLY...THEN IMPROVING TO
VFR LATE. HIGH CONFIDENCE.
SAT THRU SUN...VFR. HIGH PRES. HIGH CONFIDENCE.
MON...VFR ERLY...LOWERING CONDS LATE AS NEXT SYS APPROACHES. MDT
CONFIDENCE.
&&
.MARINE...
NO MARINE HEADLINES ANTICIPATED THROUGH MOST OF THURSDAY.
STILL A DOMINANT EASTERLY SWELL OF 3 FT AND 10 SECONDS ON THE
ATLANTIC WATERS...A RESIDUAL FROM LAST WEEKEND.
A FEW ONSHORE GUSTS NEAR OR JUST ABOVE 20 KT ARE POSSIBLE THIS
AFTERNOON. WIND TURNS LIGHT SOUTH TONIGHT THEN GUSTY S-SW 20 KT
THURSDAY AFTERNOON.
OUTLOOK...
THU NIGHT THRU FRI...SLY WILL BE PRESENT AND WE WILL PROB BE
LOOKING AT MARGINAL SCA CONDS BY FRI. WE MAY BE JUST UNDER SCA
CONDS THU NIGHT.
FRI NIGHT...WIND SHIFTS TO W THEN NW BEHIND CFP AND DECREASE.
SEAS DECREASE AS WELL. NO MARINE HEADLINES EXPECTED.
SAT THRU SUN...NO MARINE HEADLINES ANTICIPATED.
MON...SLY FLOW INCREASES IN ADVANCE OF THE NEXT LOW PRES SYS AND
SEAS RESPOND IN KIND. SCA FLAGS MAY BE NEEDED BY THE END OF THE
PD.
&&
.FIRE WEATHER...
SPS ISSUED FOR NJ AND PA WILL EXPIRE AT 19Z. RH NOW DOWN BELOW 25
PCT EXCEPT COOLER SEABREEZED COASTAL REAL ESTATE.
LOOKING AHEAD TO THURSDAY...SOUTHWEST WINDS BECOME INCREASINGLY
GUSTY IN THE AFTERNOON...UP TO AT LEAST 20 MPH AT TIMES. RH VALUES
ALSO DECREASE IN THE AFTERNOON...BELOW 30 PERCENT OVER PORTIONS OF
THE AREA, MAINLY PHL NORTHWARD.THE MAIN UNCERTAINTY WILL BE THE
MAGNITUDE OF THE WIND GUSTS...WITH RED FLAG CONDITIONS REMAINING A
POSSIBILITY. COLLABORATING A POSSIBLE FIRE WEATHER WATCH ISSUANCE
AROUND 230 PM.
&&
.EQUIPMENT...
BUOY 44009 (DE BAY BUOY LOCATED 26 NM SOUTHEAST OF CAPE MAY NJ) IS
SLATED FOR RESTORATION OF WIND INFORMATION AROUND JULY 5, 2016.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...NIERENBERG
NEAR TERM...DRAG
SHORT TERM...DRAG
LONG TERM...NIERENBERG
AVIATION...DRAG/NIERENBERG
MARINE...DRAG/NIERENBERG
FIRE WEATHER...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
210 PM EDT WED APR 20 2016
.SYNOPSIS...
HIGH PRESSURE IS BUILDING SOUTHEAST OVER THE MID ATLANTIC STATES
THIS AFTERNOON. LOW PRESSURE IN THE UPPER MISSISSIPPI VALLEY ON
THURSDAY WILL MOVE INTO THE SAINT LAWRENCE VALLEY AND LEAD TO A
COLD FRONTAL PASSAGE ACROSS OUR AREA FRIDAY NIGHT. CANADIAN HIGH
PRESSURE WILL SLOWLY MOVE OVER OUR REGION THIS WEEKEND. A COMPLEX
FRONTAL BOUNDARY WILL SETUP OVER OUR AREA BY EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
2PM UPDATE: TEMPS MAY MAX AT 69F AROUND 430PM. BRILLIANT SUNSHINE.
WINDS HAVE DIMINISHED PER HRRR EXCEPT AS PER HRRR JUST BEHIND THE
SEABREEZE. RH THIS AFTN DOWN TO 15 PCT.
TONIGHT...AM A LITTLE CONCERNED ABOUT FROST POTENTIAL AND MAY
ISSUE A FROST ADVY FOR PORTION OF NJ IN THE 330 PM FCST. THIS
MORNINGS MINS WERE 28F IN WALPACK OF NW NJ AND MANY 30-36F LOWS
FROM NORTHERN CAPE MAY COUNTY NORTH THROUGH THE PINEBARRENS REGION
ON UP INTO NW NJ. NEARLY CALM WIND WITH MOSTLY CLEAR SKY (A BIT
OF CIRRUS TOWARD DAWN). PROPOSED FROST ADVY WOULD BE INTERIOR
OCEAN SE BURLINGTON, INTERIOR ATLC AS WELL AS SUSSEX, WARREN,
MORRIS AND NORTHAMPTON COUNTIES.
THIS PART OF THE FORECAST IS A 50 50 BLEND OF THE 12Z/20 GFS/NAM
GUIDANCE THEN COOLED 2-4F IN THE COUNTRYSIDE THROUGH 11Z THURSDAY
PER EXPECTED NEARLY IDEAL RADIATIONAL COOLING CONDITIONS BUT ALSO
REFLECTS THE MUCH LOWER THAN FCST DEWPOINTS.
&&
.SHORT TERM /THURSDAY/...
THURSDAY...A SUNNY RAPIDLY WARMING START WITH GUSTY SW WINDS 15-20
MPH DEVELOPING LATE MORNING. INCREASING MID AND LATE AFTERNOON
CLOUD COVER AHEAD OF A WEAK INSTABILITY BURST THAT COULD SPREAD
SPRINKLES INTO NE PA BY 6PM. FIRE WEATHER IS THE MAIN CONCERN
THURSDAY AND WITH SOME UNCERTAINTY AS DISCUSSED IN THE FIRE WEATHER
SECTION. WIND GUSTS MAY APPROACH 25 MPH DURING THE AFTERNOON,
ESPECIALLY NORTH OF PHILADELPHIA.
THIS PART OF THE FCST WAS MOSTLY THE 12Z/20 GFS WARMER TEMP GUIDANCE,
THE DRIER NAM GUIDANCE AND A BLEND OF THE NAM/GFS WINDS AND SKYCOVER.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
MID LEVEL LOW AT THE CENTER OF THE RECENT BLOCKING PATTERN WILL
GRADUALLY MOVE EASTWARD, BECOMING AN OPEN WAVE AS IT REACHES THE
MIDDLE ATLANTIC COAST, ACCOMPANIED BY A SLOW MOVING COLD FRONTAL
PASSAGE FRIDAY NIGHT. MEANWHILE, CLOSED MID-LEVEL VORTEX OVER THE
CLIMATOLOGICALLY FAVORED BAFFIN ISLAND SLOWLY MOVES SOUTHEASTWARD,
RE-ESTABLISHING ITSELF JUST NORTHEAST OF JAMES BAY BY EARLY NEXT
WEEK. THIS WILL ESTABLISH A FAST, WESTERLY FLOW ACROSS THE REGION
LATE THIS WEEKEND INTO EARLY NEXT WEEK, WHICH SEVERAL SHORTWAVE
DISTURBANCES WILL TRAVERSE, AS THEY EXIT A MEAN TROUGH SETTING UP
OVER THE WESTERN CONUS DURING THIS TIME FRAME. THE MOST
UNCERTAINTY IS WITH REGARD TO THE EVOLUTION OF A FRONTAL BOUNDARY
EARLY NEXT WEEK, AS TO WHERE IT SETS UP WITH RESPECT TO OUR
REGION, AND THE RESULTANT SENSIBLE WEATHER IMPACTS.
FRIDAY...THERE IS SOME CONVECTIVE POTENTIAL, AS A COLD FRONT IS
POISED TO MOVE THROUGH OUR REGION BY FRI NIGHT. INSTABILITY WILL
BE LIMITED GIVEN CONSIDERABLE CLOUD COVER, WITH BEST CHANCE FOR
THUNDER TO OUR SOUTHWEST. THEREFORE, HAVE NOT ADDED THUNDER TO THE
FORECAST ATTM.
SATURDAY AND SUNDAY...BENIGN PERIOD OF WEATHER WITH HIGH PRESSURE IN
CONTROL. THE MAIN CONCERN WILL BE THE POTENTIAL FOR A FROST/FREEZE
SUNDAY MORNING, PARTICULARLY NORTH OF THE I-78 CORRIDOR. ALTHOUGH
THE BOUNDARY LAYER IS EXPECTED TO DECOUPLE, MID AND HIGH LEVEL
MOISTURE MAY PREVENT IDEAL RADIATIONAL COOLING, SO THERE IS
CONSIDERABLE UNCERTAINTY AT THIS TIME.
SUNDAY NIGHT THRU TUESDAY...AS MENTIONED, THERE IS CONSIDERABLE
UNCERTAINTY DURING THIS TIME FRAME, WHICH GENERALLY LEADS TO BELOW
AVERAGE CONFIDENCE IN OUTCOMES. A SLOW MOVING FRONTAL BOUNDARY WILL
CROSS THE REGION, WITH POSSIBLY A FEW WAVES OF LOW PRESSURE TRAVERSING
IT. GENERALLY UNSETTLED WEATHER IS ANTICIPATED, WITH SOME BENEFICIAL
RAINFALL POSSIBLE.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
REST OF TODAY...VFR CLEAR. LIGHT VARIABLE WIND TRENDING SOUTHEAST
TO SOUTH LATE IN THE DAY. THE COASTAL SEABREEZE WILL BE MOVING
WESTWARD- INLAND THIS AFTERNOON WITH THOSE SEA BREEZES HAVING A
FEW GUSTS TO 18-21 KT. THIS WIND SHIFT COULD REACH PHL LATE
AFTERNOON OR EARLY EVENING AND ATTEMPTED TIMING IS IN THE 18Z TAFS.
TONIGHT...VFR CLEAR THEN PATCHY AC/CIRRUS TOWARD 10Z/21. WIND
BECOMING NEARLY CALM LATER THIS EVENING THEN LIGHT SOUTHERLY
TOWARD MORNING.
THURSDAY...VFR SCT-BKN CLOUDS AOA 12000 FT DURING THE MORNING WITH
MULTI LAYERS DEVELOPING BY 21Z AOA 5000 FT. S-SW WIND THURSDAY
WITH MIDDAY-AFTERNOON GUSTS AROUND 20 KT.
OUTLOOK...
VFR CONDITIONS THU NIGHT. MVFR POSSIBLE IN SHRA AND TSRA FRI AND
FRI NIGHT WITH THE PASSAGE OF A COLD FRONT, AS WELL AS A LOW
PROBABILITY OF WEST-SOUTHWEST WIND GUSTS TO 25 KNOTS. VFR IS
ANTICIPATED BOTH SAT AND SUN AS HIGH PRESSURE SETTLES OVER THE
TERMINALS.
&&
.MARINE...
NO MARINE HEADLINES ANTICIPATED THROUGH MOST OF THURSDAY.
STILL A DOMINANT EASTERLY SWELL OF 3 FT AND 10 SECONDS ON THE
ATLANTIC WATERS...A RESIDUAL FROM LAST WEEKEND.
A FEW ONSHORE GUSTS NEAR OR JUST ABOVE 20 KT ARE POSSIBLE THIS
AFTERNOON. WIND TURNS LIGHT SOUTH TONIGHT THEN GUSTY S-SW 20 KT
THURSDAY AFTERNOON.
OUTLOOK...
A COLD FRONT WILL TRAVERSE THE COASTAL WATERS FRIDAY NIGHT.
SOUTHWEST WINDS IN ADVANCE OF THIS FRONT ARE EXPECTED TO FALL JUST
SHORT OF SCA THRESHOLD THURSDAY AFTERNOON INTO FRIDAY NIGHT, BUT
IT/S A CLOSE CALL, AS WAVE HEIGHTS HAVE A BETTER CHANCE OF MEETING
THE 5FT CRITERIA FOR SCA FOR HAZARDOUS SEAS. THERE IS GREATER
UNCERTAINTY WITH REGARD TO WHETHER NORTH-NORTHWEST WINDS REACH SCA
LEVELS BEHIND THIS FRONT FOR A BRIEF PERIOD OF TIME BOTH SATURDAY
MORNING AND AGAIN SATURDAY NIGHT. HIGH PRESSURE WILL MOVE OVER THE
COASTAL WATERS SUNDAY, WITH TRANQUIL, SUB-SCA CONDITIONS EXPECTED.
&&
.FIRE WEATHER...
SPS ISSUED FOR NJ AND PA WILL EXPIRE AT 19Z. RH NOW DOWN BELOW 25
PCT EXCEPT COOLER SEABREEZED COASTAL REAL ESTATE.
LOOKING AHEAD TO THURSDAY...SOUTHWEST WINDS BECOME INCREASINGLY
GUSTY IN THE AFTERNOON...UP TO AT LEAST 20 MPH AT TIMES. RH VALUES
ALSO DECREASE IN THE AFTERNOON...BELOW 30 PERCENT OVER PORTIONS OF
THE AREA, MAINLY PHL NORTHWARD.THE MAIN UNCERTAINTY WILL BE THE
MAGNITUDE OF THE WIND GUSTS...WITH RED FLAG CONDITIONS REMAINING A
POSSIBILITY. COLLABORATING A POSSIBLE FIRE WEATHER WATCH ISSUANCE
AROUND 230 PM.
&&
.EQUIPMENT...
BUOY 44009 (DE BAY BUOY LOCATED 26 NM SOUTHEAST OF CAPE MAY NJ) IS
SLATED FOR RESTORATION OF WIND INFORMATION AROUND JULY 5, 2016.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DRAG/FRANCK 208
NEAR TERM...DRAG 208
SHORT TERM...DRAG 208
LONG TERM...FRANCK
AVIATION...DRAG/FRANCK 208
MARINE...DRAG/FRANCK 208
FIRE WEATHER...208
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1051 PM EDT THU APR 21 2016
.SYNOPSIS...
SURFACE HIGH PRESSURE OFF THE COAST WILL CIRCULATE A MOIST
SOUTHERLY FLOW INTO THE FORECAST AREA AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT WILL CROSS THE AREA FRIDAY NIGHT. SHOWERS AND
THUNDERSTORMS ARE EXPECTED AHEAD OF THE FRONT FRIDAY. DRY HIGH
PRESSURE WILL BUILD INTO THE REGION LATE SATURDAY THROUGH TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
MOISTURE WILL BE ON THE INCREASE IN THE SOUTHERLY FLOW WELL AHEAD
OF THE COLD FRONT TONIGHT. RADAR TRENDS AND THE HRRR SUPPORT
SCATTERED SHOWERS IN THE FORECAST AREA MAINLY AFTER 200 AM.
OBSERVATION TRENDS SUPPORT THE MODEL FORECAST OF INSTABILITY
REMAINING WEAK OVERNIGHT. THE THUNDERSTORM CHANCE IS LOW.
CLOUDINESS AND MIXING SHOULD HELP HOLD UP TEMPERATURES. EXPECT
LOWS MAINLY IN THE LOWER 60S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
MOST PLACES LOOK TO GET WET ON FRIDAY AS A MODERATE STRENGTH UPPER
TROF AND ASSOCIATED COLD FRONT APPROACHES FROM THE WEST. DEEP
MOISTURE FLOW AHEAD OF THE SYSTEM SHOULD RAISE PWS TO AROUND 1.5
INCHES ACROSS THE CWA...AND DECENT LIFT DUE TO DIFFERENTIAL
VORTICITY ADVECTION IN MID LEVELS AND UPPER LEVEL JET DIVERGENCE
WILL PRODUCE WIDESPREAD SHOWERS WITH A FEW THUNDERSTORMS. THERE
WILL BE SOME MODEST LOW LEVEL CAPE WITH VALUES POTENTIALLY AS HIGH
AS 1000 J/KG...BUT DEEP LAYERED SHEAR IS NOT TOO IMPRESSIVE...SO
THE THREAT FOR SEVERE WEATHER LOOKS LOW. QPF WILL GENERALLY BE 1/2
INCH OR LESS...BUT PLACES THAT DO SEE SOME THUNDERSTORMS...
ESPECIALLY IN THE SOUTHEASTERN THIRD OF THE CWA...COULD GET
LOCALLY UP TO AN INCH. TEMPS SHOULD BE SEASONABLY WARM IN THE
UPPER 70S DESPITE CLOUD COVER AS THERE WILL BE LOW LEVEL WARM
ADVECTION AHEAD OF THE COLD FRONT.
FRIDAY NIGHT...THE BEST OF THE UPPER SUPPORT SHOULD MOVE THROUGH
QUICKLY...AS WILL THE COLD FRONT. SHOWERS WILL END FROM WEST TO
EAST DURING THE EVENING...WITH JUST A FEW LINGERING IN THE
SOUTHEAST AFTER MIDNIGHT. TEMPS WILL DROP DOWN INTO THE UPPER
50S...NOT PARTICULARLY COOL AS CLOUDS WILL NOT CLEAR UNTIL LATE
AND WINDS WILL REMAIN UP.
SATURDAY SHOULD BE MOSTLY DRY AS THE FRONT MOVES OFFSHORE. I CANT
RULE OUT A SHOWER IN THE NORTHEAST AS ANOTHER SPOKE OF ENERGY
DROPS INTO NORTH CAROLINA...BUT CHANCES LOOK TOO LOW AT THIS TIME
TO MENTION IN THE FORECAST. TEMPS WILL BE SEASONABLE WITH MID 70S
NORTH TO NEAR 80 IN THE CSRA.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
A SURFACE AREA OF HIGH PRESSURE WILL MOVE INTO THE SOUTHEAST FROM
SUNDAY INTO TUESDAY...KEEPING THE CWA DRY. THE AIR MASS WILL WARM
UP UNDER SUN ANGLE EQUIVALENT TO LATE AUGUST...WITH MAX TEMPS IN
THE LOWER TO MID 80S ON SUNDAY TO THE UPPER 80S TO NEAR 90 ON
TUESDAY. A COLD FRONT WILL APPROACH THE AREA FROM THE NORTH ON
WEDNESDAY...BUT IT IS TOO EARLY TO TELL IF IT WILL STALL JUST
NORTH OF THE CWA OR MAKE IT INTO THE CWA. MOST OF THE MID AND
UPPER LEVEL JET ENERGY WILL STAY TO THE NORTH IN EITHER CASE...BUT
A CLOSER FRONT COULD MEAN A BETTER CHANCE OF DIURNAL CONVECTION
WITH MAX TEMPS WELL UP INTO THE 80S.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS THROUGH THE EARLY MORNING HOURS...GIVING WAY TO
MVFR CONDITIONS FOR THE REMAINDER OF THE PERIOD.
MID CLOUDS REMAIN ACROSS THE AREA WITH MOISTURE INCREASING ACROSS
THE AREA. COLD FRONT CONTINUES CROSSING THE WESTERN GULF STATES
AND IS EXPECTED TO MOVE INTO THE TAF SITES FRIDAY AFTERNOON.
LOWERING CIGS CURRENTLY NOTED ACROSS CENTRAL GA WILL MOVE INTO THE
TAF SITES BETWEEN 06 AND 07Z LOWERING CIGS TO MVFR. SHOWERS WILL
APPROACH THE TAF SITES BEGINNING AROUND 10Z WITH SHOWERS EXPECTED
AT THE TAF SITES AROUND 15Z. THUNDERSTORMS ARE EXPECTED ACROSS THE
AREA WITH IMPACTS AT THE TAF SITES FROM 16Z THROUGH THE END OF THE
PERIOD. WINDS THROUGH THE PERIOD WILL BE SOUTHERLY AT 10 KNOTS OR
LESS.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE INTO SATURDAY
MORNING AS THE COLD FRONT MOVES OFFSHORE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
920 PM EDT THU APR 21 2016
.SYNOPSIS...
SURFACE HIGH PRESSURE OFF THE COAST WILL CIRCULATE A MOIST
SOUTHERLY FLOW INTO THE FORECAST AREA AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT WILL CROSS THE AREA FRIDAY NIGHT. SHOWERS AND
THUNDERSTORMS ARE EXPECTED AHEAD OF THE FRONT FRIDAY. DRY HIGH
PRESSURE WILL BUILD INTO THE REGION LATE SATURDAY THROUGH TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
MOISTURE WILL BE ON THE INCREASE IN THE SOUTHERLY FLOW WELL AHEAD
OF THE COLD FRONT TONIGHT. RADAR TRENDS AND THE HRRR SUPPORT
SCATTERED SHOWERS IN THE FORECAST AREA MAINLY AFTER 200 AM.
OBSERVATION TRENDS SUPPORT THE MODEL FORECAST OF INSTABILITY
REMAINING WEAK OVERNIGHT. THE THUNDERSTORM CHANCE IS LOW.
CLOUDINESS AND MIXING SHOULD HELP HOLD UP TEMPERATURES. EXPECT
LOWS MAINLY IN THE LOWER 60S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
MOST PLACES LOOK TO GET WET ON FRIDAY AS A MODERATE STRENGTH UPPER
TROF AND ASSOCIATED COLD FRONT APPROACHES FROM THE WEST. DEEP
MOISTURE FLOW AHEAD OF THE SYSTEM SHOULD RAISE PWS TO AROUND 1.5
INCHES ACROSS THE CWA...AND DECENT LIFT DUE TO DIFFERENTIAL
VORTICITY ADVECTION IN MID LEVELS AND UPPER LEVEL JET DIVERGENCE
WILL PRODUCE WIDESPREAD SHOWERS WITH A FEW THUNDERSTORMS. THERE
WILL BE SOME MODEST LOW LEVEL CAPE WITH VALUES POTENTIALLY AS HIGH
AS 1000 J/KG...BUT DEEP LAYERED SHEAR IS NOT TOO IMPRESSIVE...SO
THE THREAT FOR SEVERE WEATHER LOOKS LOW. QPF WILL GENERALLY BE 1/2
INCH OR LESS...BUT PLACES THAT DO SEE SOME THUNDERSTORMS...
ESPECIALLY IN THE SOUTHEASTERN THIRD OF THE CWA...COULD GET
LOCALLY UP TO AN INCH. TEMPS SHOULD BE SEASONABLY WARM IN THE
UPPER 70S DESPITE CLOUD COVER AS THERE WILL BE LOW LEVEL WARM
ADVECTION AHEAD OF THE COLD FRONT.
FRIDAY NIGHT...THE BEST OF THE UPPER SUPPORT SHOULD MOVE THROUGH
QUICKLY...AS WILL THE COLD FRONT. SHOWERS WILL END FROM WEST TO
EAST DURING THE EVENING...WITH JUST A FEW LINGERING IN THE
SOUTHEAST AFTER MIDNIGHT. TEMPS WILL DROP DOWN INTO THE UPPER
50S...NOT PARTICULARLY COOL AS CLOUDS WILL NOT CLEAR UNTIL LATE
AND WINDS WILL REMAIN UP.
SATURDAY SHOULD BE MOSTLY DRY AS THE FRONT MOVES OFFSHORE. I CANT
RULE OUT A SHOWER IN THE NORTHEAST AS ANOTHER SPOKE OF ENERGY
DROPS INTO NORTH CAROLINA...BUT CHANCES LOOK TOO LOW AT THIS TIME
TO MENTION IN THE FORECAST. TEMPS WILL BE SEASONABLE WITH MID 70S
NORTH TO NEAR 80 IN THE CSRA.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
A SURFACE AREA OF HIGH PRESSURE WILL MOVE INTO THE SOUTHEAST FROM
SUNDAY INTO TUESDAY...KEEPING THE CWA DRY. THE AIR MASS WILL WARM
UP UNDER SUN ANGLE EQUIVALENT TO LATE AUGUST...WITH MAX TEMPS IN
THE LOWER TO MID 80S ON SUNDAY TO THE UPPER 80S TO NEAR 90 ON
TUESDAY. A COLD FRONT WILL APPROACH THE AREA FROM THE NORTH ON
WEDNESDAY...BUT IT IS TOO EARLY TO TELL IF IT WILL STALL JUST
NORTH OF THE CWA OR MAKE IT INTO THE CWA. MOST OF THE MID AND
UPPER LEVEL JET ENERGY WILL STAY TO THE NORTH IN EITHER CASE...BUT
A CLOSER FRONT COULD MEAN A BETTER CHANCE OF DIURNAL CONVECTION
WITH MAX TEMPS WELL UP INTO THE 80S.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS THROUGH THE EARLY MORNING HOURS...GIVING WAY TO
MVFR CONDITIONS FOR THE REMAINDER OF THE PERIOD.
MOISTURE WILL CONTINUE INCREASING ACROSS THE AREA AS A COLD FRONT
CROSSES THE GULF STATES...WITH THE FRONT EXPECTED TO MOVE INTO THE
TAF SITES FRIDAY AFTERNOON. VFR CONDITIONS WILL CONTINUE THROUGH
THE EARLY MORNING HOURS WITH CIGS LOWERING TO MVFR BETWEEN 06 AND
07Z. SHOWERS WILL APPROACH THE TAF SITES BEGINNING AROUND 10Z WITH
SHOWERS EXPECTED AT THE TAF SITES AROUND 15Z. THUNDERSTORMS ARE
EXPECTED ACROSS THE AREA WITH IMPACTS AT THE TAF SITES FROM 16Z
THROUGH THE END OF THE PERIOD. WINDS THROUGH THE PERIOD WILL BE
SOUTHERLY AT 10 KNOTS OR LESS. LOW LEVEL WIND SHEAR POSSIBLE 04Z-
12Z AS A LOW LEVEL JET DEVELOPS OVER THE REGION. HAVE NOT INCLUDED
LOW LEVEL WIND SHEAR IN TAFS AT THIS TIME GIVEN LOW CONFIDENCE.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE INTO SATURDAY
MORNING AS THE COLD FRONT MOVES OFFSHORE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
327 PM EDT WED APR 20 2016
.SYNOPSIS...
A WEAK COLD FRONT WILL DISSIPATE NEAR THE CHARLESTON AREA TONIGHT.
ATLANTIC HIGH PRESSURE WILL PREVAIL THURSDAY INTO FRIDAY. A COLD
FRONT WILL MOVE THROUGH FRIDAY NIGHT INTO SATURDAY...FOLLOWED BY
HIGH PRESSURE INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE WEAK BACKDOOR COLD FRONT WILL SETTLE IN ACROSS THE CHARLESTON
TRI-COUNTY AREA THIS EVENING AND DISSIPATE. THE REMNANTS OF THE
FRONT WILL LINGER WILL THROUGH SUNRISE WITH MODELS SHOWING LOW-
LEVEL POOLING IN ITS VICINITY. THIS COULD PROMOTE SOME STRATUS
BUILD DOWN AND POSSIBLY FOG AFTER MIDNIGHT...BUT RAP POINT
SOUNDINGS AT KCHS..KDYB AND KMKS ARE NOT OVERLY IMPRESSIVE FOR
SIGNIFICANT FOG FORMATION. THIS IS CERTAINLY SOMETHING THAT WILL
NEED TO BE MONITORED THROUGH THE NIGHT. WILL CARRY PATCHY FOG FOR
THE CHARLESTON TRI-COUNTY AREA FOR NOW AND SHOW SKIES BECOMING
MOSTLY CLOUDY FOR AREAS ALONG/NORTH OF I-26. ELSEWHERE...
CONDITIONS WILL FAVOR JUST SHALLOW GROUND FOG A FEW HOURS PRIOR
TO SUNRISE.
ANOTHER A-TYPICAL TEMPERATURE DISTRIBUTION IS ON TAP TONIGHT WITH
THE COOLEST CONDITIONS ONCE AGAIN OCCURRING ACROSS INTERIOR
SOUTHEAST GEORGIA...MORE SPECIFICALLY IN THE FORT STEWART-
LUDOWICI-DARIEN CORRIDOR. HIGH CLOUDS ARE FORECAST TO THIN ENOUGH
TO SUPPORT MODEST RADIATIONAL COOLING WITH TEMPERATURE LIKELY
CRATERING JUST BEFORE DAYBREAK. STRATUS SHOULD KEEP TEMPERATURES A
BIT MORE ELEVATED ACROSS THE NORTHERN ZONES. LOWS WILL RANGE FROM
THE UPPER 50S/NEAR 60 ACROSS THE CHARLESTON TRI-COUNTY AREA TO THE
MID 50S ACROSS THE DARIEN-FORT STEWART-LUDOWICI CORRIDOR.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
THURSDAY...SURFACE HIGH PRESSURE IN THE ATLANTIC WILL BE SHIFTING
EASTWARD WHILE A RIDGE AXIS IS POSITIONED OVER THE EAST COAST.
MOISTURE GRADUALLY INCREASES AS WEAK CONVERGENCE SETS UP JUST
OFFSHORE. THIS MAY LEAD TO A FEW LIGHT SHOWERS OFFSHORE. IT IS NOT
OUT OF THE QUESTION THAT A STRAY LIGHT SHOWER COULD REACH NORTHERN
CHARLESTON COUNTY IN THE AFTERNOON...BUT THE PROBABILITIES IN THIS
OCCURRING ARE LOW. REGARDLESS...WE HAVE MAINTAINED A BRIEF PERIOD OF
SLIGHT CHANCE POPS IN THE FORECAST TO ACCOUNT FOR THIS. TEMPERATURES
WILL BE IN THE LOWER 80S AWAY FROM THE LOCALLY COOLER COAST.
INCREASING CLOUDS LATE IN THE DAY AND ESPECIALLY AT NIGHT SHOULD
KEEP LOWS MILD...IN THE LOW 60S.
FRIDAY...THE ATLANTIC SURFACE HIGH WILL BE JUST FAR ENOUGH SHORE TO
LOSE INFLUENCE OVER OUR AREA. INSTEAD THE DOMINANT FEATURE WILL
BECOME A TROUGH MOVING FROM THE GREAT LAKES REGION INTO THE
NORTHEAST. THIS FEATURE WILL PUSH A COLD FRONT TOWARDS OUR AREA.
S/SW WINDS AT THE SURFACE AND AROUND 25 KT OF SW FLOW AT 850 MB WILL
PUSH PWATS TO NEAR 1.50 INCHES. THIS COMBINED WITH SOME INSTABILITY
AND ENERGY FROM A PASSING SHORTWAVE WILL GENERATE SHOWERS AND
THUNDERSTORMS. THE SEVERE THREAT IS LOW BECAUSE INSTABILITY IS
UNIMPRESSIVE AND SHEAR IS WEAK. DESPITE CLOUDY SKIES...COMPRESSIONAL
HEATING AHEAD OF THE FRONT SHOULD ALLOW HIGHS TO REACH AROUND 80
DEGREES. MODELS HAVE COME INTO BETTER AGREEMENT WITH TIMING OF
FRONTAL PASSAGE...SHOWING THE FRONT CROSSING THE LOCAL AREA LATE
FRIDAY NIGHT INTO EARLY SATURDAY. ADJUSTED THE POPS AND WEATHER
GRIDS TO BETTER REFLECT THIS TIMING. PRECIPITATION WILL QUICKLY
DECREASE AS THE FRONT MOVES OFFSHORE EARLY SATURDAY MORNING. QPF
SHOULD GENERALLY BE AROUND 0.25 INCHES. FRIDAY NIGHT LOWS WILL BE
MILD AGAIN...IN THE LOWER 60S.
SATURDAY...SHORTWAVE ENERGY LAGGING BEHIND THE FRONT IN COMBINATION
WITH WEAK INSTABILITY MAY BE ENOUGH TO ALLOW A FEW SHOWERS/ISOLATED
THUNDERSTORMS TO DEVELOP IN THE AFTERNOON. SLIGHT CHANCE POPS REMAIN
IN THE FORECAST. HIGHS WILL RANGE FROM THE UPPER 70S IN THE
NORTH...TO THE LOWER 80S IN THE SOUTH.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH ON SUNDAY BEFORE SHIFTING
INTO THE ATLANTIC BY MONDAY. THE FORECAST AREA WILL LARGELY REMAIN
UNDER THE INFLUENCE OF THE SURFACE HIGH THROUGH MIDDLE OF NEXT WEEK.
MODELS DO HINT THAT A BACKDOOR COLD FRONT MAY TRY TO DESCEND INTO
THE AREA LATE TUESDAY OR WEDNESDAY HOWEVER THERE ARE STILL LARGE
DISCREPANCIES BETWEEN MODELS ON TIMING AND EVOLUTION OF THIS
FEATURE. TEMPERATURES WILL BE ON A WARMING TREND THROUGH THE PERIOD
WITH HIGHS SOLIDLY IN THE 80S EACH AFTERNOON.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR. SHALLOW GROUND FOG IS POSSIBLE AT BOTH TERMINALS TONIGHT AS
DEWPOINTS RISE AND WINDS GO CALM/VARIABLE...BUT BETTER CHANCES FOR
IMPACTS WILL BE AT KCHS. LOW STRATUS IS A POSSIBILITY CLOSER TO
THE BACKDOOR FRONT...BUT THINK THE HIGHEST CHANCES WILL REMAIN
NORTH OF KCHS.
EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS ARE POSSIBLE FRIDAY
INTO EARLY SATURDAY AS A COLD FRONT MOVES THROUGH THE AREA WITH
SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
TONIGHT...WINDS WILL GRADUALLY TURN ONSHORE ACROSS THE ENTIRE
MARINE AREA. A BIT MORE OF A NORTHEAST COMPONENT WILL LINGER ALONG
THE CHARLESTON COUNTY COAST IN THE WAKE OF A WEAK BACKDOOR
FRONT...BUT EVEN DIRECTIONS THERE SHOULD TURN MORE ONSHORE JUST
BEFORE SUNRISE THURSDAY. WINDS WILL REMAIN LESS THAN 10 KT WITH
SEAS 1-2 FT NEARSHORE WATERS...2-3 FT OFFSHORE WATERS.
THURSDAY THROUGH MONDAY...ATLANTIC HIGH PRESSURE WILL REMAIN THE
DOMINANT FEATURE THURSDAY INTO FRIDAY. SOUTH/SOUTHWEST WINDS WILL
INCREASE FRIDAY AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF AN
APPROACHING COLD FRONT...HOWEVER CONDITIONS WILL REMAIN BELOW SMALL
CRAFT ADVISORY CRITERIA. THE FRONT WILL CROSS THE WATERS EARLY
SATURDAY...FOLLOWED BY HIGH PRESSURE THROUGH EARLY NEXT WEEK. WINDS
THROUGH THE PERIOD WILL GENERALLY BE 15 KT OR LESS...WITH SEAS 2-4
FEET ON AVERAGE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST/MS
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
214 PM EDT WED APR 20 2016
.SYNOPSIS...
A DIFFUSE FRONT ACROSS THE AREA WILL CONTINUE TO WEAK TONIGHT.
INCREASING MOISTURE AND A COLD FRONT WILL MOVE THROUGH FROM THE
WEST LATE THURSDAY THROUGH EARLY SATURDAY...BRINGING A CHANCE OF
SHOWERS AND A FEW THUNDERSTORMS...MAINLY DURING FRIDAY AFTERNOON
AND EVENING. DRY HIGH PRESSURE WILL BUILD BACK INTO THE REGION
LATE SATURDAY THROUGH TUESDAY. TEMPERATURES EXPECTED TO BE AT OR
ABOVE NORMAL.
&&
.NEAR TERM /THROUGH TONIGHT/...
A COLD FRONT MOVING INTO THE SOUTHERN MIDLANDS IS EXPECTED TO STALL.
PRECIPITABLE WATER WAS BELOW ONE INCH EARLY THIS AFTERNOON. HIGH
RESOLUTION MODELS SHOW A LIGHT INCREASE IN PRECIPITABLE WATER ACROSS
THE PEE DEE REGION. BOTH THE HRRR AND RAP13 SHOW A FEW SHOWERS
DEVELOPING OVER THE PEE DEE REGION LATE THIS AFTERNOON. WILL
CONTINUE WITH POPS BELOW 20 PERCENT.
MAINLY THIN HIGH LEVEL CLOUDS WILL CONTINUE ACROSS THE AREA.
AFTERNOON HIGHS IN THE UPPER 70S NORTH TO MID 80S SOUTH LOOK
REASONABLE.
STALLED SURFACE FRONT WILL REMAIN ACROSS THE REGION TONIGHT.
DRY FORECAST TONIGHT AS INSTABILITY WEAKENS. CONSENSUS INDICATE
OVERNIGHT LOWS IN THE MID 50S TO AROUND 60.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
EARLY MORNING LOW CLOUDS THURSDAY SHOULD MIX OUT BY MID MORNING.
SURFACE PRESSURE RIDGE OFFSHORE WILL EXTEND INTO THE AREA THROUGH
THE DAY. ALSO...UPPER LEVEL RIDGE OVER THE AREA SHIFTING EAST
ALONG THE COAST LATE IN THE DAY. EXPECT LIMITED SHOWERS DUE TO AIR
MASS STILL RELATIVELY DRY AND SUBSIDENCE EXPECTED. UPPER LEVEL
TROUGH OVER THE MISSISSIPPI VALLEY MOVING EAST TOWARD OHIO VALLEY
THURSDAY NIGHT. INCREASING SOUTHWEST FLOW SHOULD RESULT IN
MOISTURE INCREASE FROM THE WEST/PRECIPITABLE WATER INCREASE 1.25
TO 1.5 INCHES BY MORNING. MOS POPS INCREASE AFTER MIDNIGHT. A FEW
SHOWERS MAY DEVELOP OR MOVE IN FROM THE WEST TOWARD FRIDAY
MORNING. UPPER TROUGH MOVING THROUGH THE EASTERN CONUS FRIDAY WILL
DRIVE COLD FRONT TOWARD THE REGION. AIR MASS BECOMES WEAKLY TO
MODERATELY UNSTABLE BY AFTERNOON. MODELS SUGGEST SOME SHOWERS
EARLY IN THE DAY THEN ANOTHER SHOT IN THE AFTERNOON. CONVECTION IN
THE MORNING AND EXTENSIVE CLOUDS MAY LIMIT DEGREE OF INSTABILITY
LATER IN THE DAY. STRONGER CONVECTION MORE LIKELY WEST OF THE
REGION BACK IN NORTHWEST GEORGIA WHERE SHEAR STRONGER. DECREASING
POPS FRIDAY NIGHT INTO SATURDAY MORNING AS FRONT MOVES THROUGH THE
AREA. 850MB TROUGH OFF THE COAST EARLY SATURDAY AND EXPECT DRIER
AIR ADVECTION SO CUT POPS BACK FROM PREVIOUS FORECAST DURING THAT
PERIOD. MOS TEMPERATURES THROUGH THE PERIOD SEEM REASONABLE
ALTHOUGH FAVOR SLIGHTLY HIGHER TEMPERATURES DURING THE DAY DUE TO
BIAS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
DRY HIGH PRESSURE TO SETTLE INTO THE SE CONUS LATE SATURDAY
THROUGH MONDAY. MOISTURE INCREASE MID WEEK AND ANOTHER FRONT
POSSIBLY MOVING SOUTH FROM THE NORTH MAY LEAD TO ISOLATED OR
SCATTERED AFTERNOON SHOWERS TUESDAY AND WEDNESDAY. TEMPERATURES
SHOULD BE AT OR ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
HIGH CONFIDENCE FOR VFR CONDITIONS THROUGH THIS EVENING.
A WEAK COLD FRONT OVER CENTRAL SOUTH CAROLINA EXPECTED TO STALL
ACROSS THE AREA TONIGHT. WINDS LESS THAN 10 KNOTS...BECOMING EAST TO
SOUTHEAST THIS AFTERNOON. HIGH CLOUDS WILL CONTINUE TO STREAM OVER
THE REGION AS WEAK UPPER RIDGING CROSSES THE AREA.
MODELS INDICATE LOW LEVEL MOISTURE INCREASING OVERNIGHT. STILL SOME
MODEL DISCREPANCY AS TO WHERE IFR CIGS WILL DEVELOP. MODEL CONSENSUS
INDICATE LOW CLOUDS DEVELOPING ACROSS THE MIDLANDS...AFFECTING
OGB/CAE/CUB BETWEEN 03Z AND 13Z. GIVEN LOW CONFIDENCE...HAVE
INDICATED SCT CLOUDS AROUND 1000 FEET. THERE IS ALSO THE POTENTIAL
FOR FOG TO DEVELOP AT AGS GIVEN MOIST SOUTHEAST LOW LEVEL FLOW.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE LATE THURSDAY
NIGHT THROUGH EARLY SATURDAY AS A COLD FRONT CROSSES THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE, IL
1226 PM CDT WED APR 20 2016
.SHORT TERM...
329 AM CDT
THROUGH TONIGHT...
THIS AFTERNOON AND EVENING WILL BRING THE HIGHEST CHANCE FOR
SHOWERS IN THE FORECAST AREA IN TEN DAYS. WE HAVE KEPT THE MAIN
THEME OF RAIN TIMING BEING MID- AFTERNOON THROUGH EVENING
SPREADING FROM WEST TO EAST AND JUST REFINING THAT TO THE HOURLY
LEVEL. DID INCREASE THE THUNDER POTENTIAL SOME OVER THE ILLINOIS
PART OF THE CWA THOUGH THE RISK FOR SEVERE WEATHER REMAINS QUITE
LOW.
THE PERSISTENT LARGE UPPER LOW IS GYRATING ITS WAY SLOWLY EAST
THIS MORNING WITH ITS CENTER NOW OVER THE CENTRAL PLAINS. A 90 KT
UPPER JET ROUNDING THE SOUTHERN EDGE OF THIS CENTER AND ASSOCIATED
DEEP PV ANOMALY THIS MORNING WILL HELP RE-DEEPEN THE LOW CENTER BY
THIS EVENING OVER IOWA. UPPER FORCING AND ASSOCIATED LIFT IN
ADVANCE OF THIS...ALONG WITH A LOW-LEVEL RESPONSE OF THETA-E
ADVECTION...WILL SPREAD OVER ILLINOIS DURING THE AFTERNOON. GIVEN
THIS WILL BE DURING THE PEAK HEATING TIME...EXPECT THAT THERE WILL
BE AN INCREASE IN SHOWER AND STORM ACTIVITY...LIKELY JUST WEST OF
THE CWA ALONG THE SYSTEM COLD FRONT DURING THE EARLY TO MID
AFTERNOON AND SPREADING EAST FROM THERE. CONVECTIVE ALLOWING
MODELS SUCH AS THE HRRR INDICATE THIS INCREASE AND TIMING...THOUGH
HAVE VARIED QUITE A BIT FROM RUN-TO-RUN ON THE COVERAGE. A FEW
THINGS COULD INDEED LIMIT AFTERNOON SHOWER/STORM COVERAGE SUCH AS
THE NARROW NATURE OF THE DEEP MOIST PLUME WRAPPING NORTHWARD INTO
THIS SYSTEM. OVERALL THOUGH EXPECT THE AFOREMENTIONED FORCING JUST
AHEAD OF THE SYSTEM DRY SLOT TO BE ENOUGH TO PROVIDE AN UPTICK IN
SHOWERS DURING THE AFTERNOON INTO EARLY EVENING...WARRANTING
LIKELY WORDING IN THE FORECAST.
THE INSTABILITY MAGNITUDES /A FEW HUNDRED J/KG/ ARE BETTER FOR
THUNDER THAN PREVIOUS FORECAST CYCLES...MAINLY FOR THE NORTH
CENTRAL ILLINOIS PART OF THE FORECAST AREA. THE TIMING OF THE
MAIN SHOWER AND POSSIBLE THUNDERSTORM AREAS APPEAR TO BE EARLY
ENOUGH TO PREVENT DEEPER INSTABILITY RETURN TO LEVELS THAT WOULD
WARRANT A THREAT FOR SEVERE STORMS...THOUGH A FEW STRONG ONES WITH
MAYBE SOME SMALL HAIL ARE POSSIBLE INTO THE WESTERN CWA WITH
FREEZING LEVELS A LITTLE BELOW 10KFT.
IN TERMS OF TEMPERATURES...THE FRONTAL BOUNDARY WHICH BROUGHT A
30 DEGREE TEMPERATURE GRADIENT ACROSS THE CWA YESTERDAY...IS NOW
DRAPED OVER CENTRAL ILLINOIS TO SOUTHERN INDIANA. THIS WILL LIFT
NORTHWARD AS A WARM FRONT TODAY. THE FRONTAL PROGRESSION WILL
PROBABLY NOT BE FAR AHEAD OF RAIN SHOWER ACTIVITY WHICH MAKES THE
TEMPERATURE FORECAST CHALLENGING. NORTHERN AREAS WILL CERTAINLY BE
WARMER THAN YESTERDAY BUT HOW MUCH SO WILL DEPEND ON THE FRONTAL
PASSAGE TIMING. ONSHORE FLOW A GOOD PART OF THE DAY FROM CHICAGO
NORTHWARD WILL KEEP LAKESIDE TEMPERATURES COOLER AGAIN. FAR
SOUTHERN AREAS HAVE THE CHANCE AGAIN TO REACH UPPER 70S.
AS THE SYSTEM DRY SLOT WORKS OVERHEAD LATE THIS EVENING INTO
OVERNIGHT...THE SHOWER ACTIVITY WILL PUSH NORTHEAST. THE LOW-LEVEL
COOL ADVECTION WILL ACTUALLY WEAKEN GIVEN THE OVERALL OCCLUDED
NATURE OF THIS SYSTEM...SO LOWS LOOK TO REMAIN IN THE 50S
AREAWIDE.
MTF
&&
.LONG TERM...
329 AM CDT
THURSDAY THROUGH TUESDAY...
THE PRIMARY UPPER LOW WILL GRADUALLY TRANSITION INTO AN OPEN WAVE
THROUGH THURSDAY AND THURSDAY NIGHT AND SHOULD DO SO AS IT TRACKS
EASTWARD OVER THE FORECAST AREA. WHILE DRY AIR ALOFT WILL PREVENT
MUCH FOR SHOWERS THURSDAY MORNING...MOST MODEL GUIDANCE INDICATES
THE FORECAST AREA TO BE IN A FAVORABLE AREA OF UPPER SUPPORT TO AT
LEAST SEE AFTERNOON AND EARLY EVENING SCATTERED SHOWERS AND EVEN A
FEW STORMS AGAIN. WITH TEMPERATURES THURSDAY AFTERNOON WARMING
BACK INTO THE MID 60S TO LOW 70S...THERE SHOULD BE A FEW HUNDRED
J/KG OF CAPE TO WORK WITH. LOWER FREEZING LEVELS COULD PROVIDE A
FEW SMALL HAIL PRODUCERS.
BEHIND THIS TROUGH FRIDAY AND SATURDAY CONTINUE TO LOOK DRY. STOUT
NORTHEAST WINDS ON FRIDAY WILL KEEP LAKESHORE HIGHS INCLUDING
DOWNTOWN CHICAGO LIKELY SHY OF 50 DEGREES. INLAND AREAS ARE
PRESENTLY FORECAST FOR HIGHS IN THE UPPER 50S/LOWER 60S...ALTHOUGH
THIS WILL DEPEND ON CLOUDS CLEARING FRIDAY MORNING.
GIVEN THE PRESENT AMPLIFIED/SEMI-BLOCKED PATTERN ACROSS THE
EASTERN PACIFIC AND CONUS...CONFIDENCE IN THE LONGER TERM PATTERN
EVOLUTION REMAINS LOW. A MASSIVE UPPER LOW/TROUGH IS EXPECTED
ACROSS EASTERN CANADA AND THIS WILL PROVIDE NORTHWEST FLOW INTO
THE GREAT LAKES...WHILE AN UPPER LOW OVER THE SOUTHWEST U.S. IS
ANTICIPATED TO SLOWLY WORK ITS WAY EAST. TOGETHER THESE SHOULD
DEVELOP A WEST-TO-EAST BAROCLINIC ZONE ACROSS THE MIDWEST THOUGH
WHERE AND HOW ACTIVE REMAINS HIGHLY UNCERTAIN ON MODELS. THIS ALSO
LEADS TO LOW CONFIDENCE IN TEMPERATURE FORECASTS AS A LARGE RANGE
IS LIKELY ACROSS THIS BOUNDARY. RIGHT NOW HAVE FAVORED A BLEND OF
THE EC/GFS/GEM...WHICH BRINGS THE BOUNDARY INTO THE AREA MONDAY
AND JUST SOUTH BY TUESDAY.
MTF
&&
.AVIATION...
FOR THE 18Z TAFS...
AN UPPER LEVEL LOW TRAVERSING THE REGION WILL BRING SHOWERS AND A
CHANCE OF THUNDERSTORMS TO THE REGION FROM MID/LATE THIS AFTERNOON
THROUGH LATE THIS EVENING. A LEADING WAVE OF SHOWERS IS
CURRENTLY LIFTING ACROSS PORTIONS OF CENTRAL ILLINOIS AND SHOULD
ARRIVE AROUND MID AFTERNOON TO THE CHICAGO/ROCKFORD TERMINALS.
INITIALLY DRY CONDITIONS AND VERY WEAK INSTABILITY IN PLACE WILL
LIKELY RESULT IN SOME VIRGA WITH ONLY WIDELY SCATTERED SHOWERS MID
TO LATE THIS AFTERNOON. WILL HANDLE LOWER PROBABILITY OF SHOWERS
ON STATION BY CARRYING A VCSH DURING THIS TIME FRAME. NEXT WAVE OF
PRECIP WHICH IS LIFTING ACROSS THE MISSISSIPPI RIVER EARLY THIS
AFTERNOON WILL ARRIVE LATE THIS AFTERNOON OR EARLY EVENING AND
EXPECT BETTER COVERAGE OF SHOWERS AND POSSIBLY AN ISOLATED
THUNDERSTORM OR TWO. THE UPPER LOW WILL FINALLY MOVE OVERHEAD
THURSDAY AFTERNOON/EVENING BRINGING ADDITIONAL CHANCES FOR SHOWERS
AND THUNDERSTORMS.
OUTSIDE OF THE INFLUENCE OF SHOWERS...WINDS WILL CONTINUE OUT OF
THE SOUTHEAST FOR THE REST OF TODAY WITH SOME GUSTS NEAR OR
SLIGHTLY ABOVE 20 KT POSSIBLE. WINDS WILL DIMINISH LATE THIS
EVENING AND TONIGHT AND VEER TO THE SOUTH AND EVENTUALLY SOUTHWEST
AS A WARM FRONT LIFTS ACROSS THE REGION. A PERIOD OF MVFR CIGS IS
POSSIBLE AROUND THE TIME THE FRONT LIFTS THROUGH...THEN SHOULD
RETURN TO VFR AS WINDS INCREASE OUT OF THE SOUTHWEST THURSDAY.
BMD
&&
.MARINE...
228 AM CDT
A WEAK AREA OF LOW PRESSURE IS EXPECTED TO MOVE EASTWARD OVER LAKE
MICHIGAN ON THURSDAY. AS THIS LOW MOVES OVER THE LAKE...LIGHT
WINDS AND A MOIST AIR MASS COULD PRODUCE A PERIOD OF FOG OVER THE
LAKE. HOWEVER...NORTHERLY WINDS ARE EXPECTED TO INCREASE FROM
NORTH TO SOUTH OVER THE LAKE THURSDAY NIGHT INTO FRIDAY FOLLOWING
THE EASTWARD PASSAGE OF THE SURFACE LOW. THIS SHOULD RESULT IN A
PERIOD OF 30 KT NORTHERLY WINDS ON FRIDAY BEFORE WINDS ABATE
FRIDAY NIGHT AS A SURFACE RIDGE OF HIGH PRESSURE BUILDS OVER THE
UPPER GREAT LAKES. LARGE WIND WAVES...LIKELY IN EXCESS OF 5 FEET
ON SOUTHERN LAKE MICHIGAN WILL RESULT IN OUR NEXT PERIOD OF SMALL
CRAFT ADVISORY CONDITIONS FOR THE ILLINOIS AND INDIANA NEAR SHORE
WATERS.
OVER THE WEEKEND ANOTHER COLD FRONT IS EXPECTED TO SHIFT SOUTHWARD
DOWN LAKE MICHIGAN. THERE IS STILL UNCERTAINTY ON THE EXACT TIMING OF
THIS FRONT. HOWEVER...THERE ARE INDICATIONS THAT ANOTHER PERIOD OF
STRONGER NORTH-NORTHEASTERLY WINDS WILL SET UP OVER THE LAKE
POSSIBLY BY LATE SUNDAY OR MONDAY. THIS WILL BE ANOTHER PERIOD TO
WATCH FOR POSSIBLE SMALL CRAFT CONDITIONS ON THE NEAR SHORE WATERS
DUE TO WINDS AND HIGH WAVES.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE, IL
641 AM CDT WED APR 20 2016
.SHORT TERM...
329 AM CDT
THROUGH TONIGHT...
THIS AFTERNOON AND EVENING WILL BRING THE HIGHEST CHANCE FOR
SHOWERS IN THE FORECAST AREA IN TEN DAYS. WE HAVE KEPT THE MAIN
THEME OF RAIN TIMING BEING MID- AFTERNOON THROUGH EVENING
SPREADING FROM WEST TO EAST AND JUST REFINING THAT TO THE HOURLY
LEVEL. DID INCREASE THE THUNDER POTENTIAL SOME OVER THE ILLINOIS
PART OF THE CWA THOUGH THE RISK FOR SEVERE WEATHER REMAINS QUITE
LOW.
THE PERSISTENT LARGE UPPER LOW IS GYRATING ITS WAY SLOWLY EAST
THIS MORNING WITH ITS CENTER NOW OVER THE CENTRAL PLAINS. A 90 KT
UPPER JET ROUNDING THE SOUTHERN EDGE OF THIS CENTER AND ASSOCIATED
DEEP PV ANOMALY THIS MORNING WILL HELP RE-DEEPEN THE LOW CENTER BY
THIS EVENING OVER IOWA. UPPER FORCING AND ASSOCIATED LIFT IN
ADVANCE OF THIS...ALONG WITH A LOW-LEVEL RESPONSE OF THETA-E
ADVECTION...WILL SPREAD OVER ILLINOIS DURING THE AFTERNOON. GIVEN
THIS WILL BE DURING THE PEAK HEATING TIME...EXPECT THAT THERE WILL
BE AN INCREASE IN SHOWER AND STORM ACTIVITY...LIKELY JUST WEST OF
THE CWA ALONG THE SYSTEM COLD FRONT DURING THE EARLY TO MID
AFTERNOON AND SPREADING EAST FROM THERE. CONVECTIVE ALLOWING
MODELS SUCH AS THE HRRR INDICATE THIS INCREASE AND TIMING...THOUGH
HAVE VARIED QUITE A BIT FROM RUN-TO-RUN ON THE COVERAGE. A FEW
THINGS COULD INDEED LIMIT AFTERNOON SHOWER/STORM COVERAGE SUCH AS
THE NARROW NATURE OF THE DEEP MOIST PLUME WRAPPING NORTHWARD INTO
THIS SYSTEM. OVERALL THOUGH EXPECT THE AFOREMENTIONED FORCING JUST
AHEAD OF THE SYSTEM DRY SLOT TO BE ENOUGH TO PROVIDE AN UPTICK IN
SHOWERS DURING THE AFTERNOON INTO EARLY EVENING...WARRANTING
LIKELY WORDING IN THE FORECAST.
THE INSTABILITY MAGNITUDES /A FEW HUNDRED J/KG/ ARE BETTER FOR
THUNDER THAN PREVIOUS FORECAST CYCLES...MAINLY FOR THE NORTH
CENTRAL ILLINOIS PART OF THE FORECAST AREA. THE TIMING OF THE
MAIN SHOWER AND POSSIBLE THUNDERSTORM AREAS APPEAR TO BE EARLY
ENOUGH TO PREVENT DEEPER INSTABILITY RETURN TO LEVELS THAT WOULD
WARRANT A THREAT FOR SEVERE STORMS...THOUGH A FEW STRONG ONES WITH
MAYBE SOME SMALL HAIL ARE POSSIBLE INTO THE WESTERN CWA WITH
FREEZING LEVELS A LITTLE BELOW 10KFT.
IN TERMS OF TEMPERATURES...THE FRONTAL BOUNDARY WHICH BROUGHT A
30 DEGREE TEMPERATURE GRADIENT ACROSS THE CWA YESTERDAY...IS NOW
DRAPED OVER CENTRAL ILLINOIS TO SOUTHERN INDIANA. THIS WILL LIFT
NORTHWARD AS A WARM FRONT TODAY. THE FRONTAL PROGRESSION WILL
PROBABLY NOT BE FAR AHEAD OF RAIN SHOWER ACTIVITY WHICH MAKES THE
TEMPERATURE FORECAST CHALLENGING. NORTHERN AREAS WILL CERTAINLY BE
WARMER THAN YESTERDAY BUT HOW MUCH SO WILL DEPEND ON THE FRONTAL
PASSAGE TIMING. ONSHORE FLOW A GOOD PART OF THE DAY FROM CHICAGO
NORTHWARD WILL KEEP LAKESIDE TEMPERATURES COOLER AGAIN. FAR
SOUTHERN AREAS HAVE THE CHANCE AGAIN TO REACH UPPER 70S.
AS THE SYSTEM DRY SLOT WORKS OVERHEAD LATE THIS EVENING INTO
OVERNIGHT...THE SHOWER ACTIVITY WILL PUSH NORTHEAST. THE LOW-LEVEL
COOL ADVECTION WILL ACTUALLY WEAKEN GIVEN THE OVERALL OCCLUDED
NATURE OF THIS SYSTEM...SO LOWS LOOK TO REMAIN IN THE 50S
AREAWIDE.
MTF
&&
.LONG TERM...
329 AM CDT
THURSDAY THROUGH TUESDAY...
THE PRIMARY UPPER LOW WILL GRADUALLY TRANSITION INTO AN OPEN WAVE
THROUGH THURSDAY AND THURSDAY NIGHT AND SHOULD DO SO AS IT TRACKS
EASTWARD OVER THE FORECAST AREA. WHILE DRY AIR ALOFT WILL PREVENT
MUCH FOR SHOWERS THURSDAY MORNING...MOST MODEL GUIDANCE INDICATES
THE FORECAST AREA TO BE IN A FAVORABLE AREA OF UPPER SUPPORT TO AT
LEAST SEE AFTERNOON AND EARLY EVENING SCATTERED SHOWERS AND EVEN A
FEW STORMS AGAIN. WITH TEMPERATURES THURSDAY AFTERNOON WARMING
BACK INTO THE MID 60S TO LOW 70S...THERE SHOULD BE A FEW HUNDRED
J/KG OF CAPE TO WORK WITH. LOWER FREEZING LEVELS COULD PROVIDE A
FEW SMALL HAIL PRODUCERS.
BEHIND THIS TROUGH FRIDAY AND SATURDAY CONTINUE TO LOOK DRY. STOUT
NORTHEAST WINDS ON FRIDAY WILL KEEP LAKESHORE HIGHS INCLUDING
DOWNTOWN CHICAGO LIKELY SHY OF 50 DEGREES. INLAND AREAS ARE
PRESENTLY FORECAST FOR HIGHS IN THE UPPER 50S/LOWER 60S...ALTHOUGH
THIS WILL DEPEND ON CLOUDS CLEARING FRIDAY MORNING.
GIVEN THE PRESENT AMPLIFIED/SEMI-BLOCKED PATTERN ACROSS THE
EASTERN PACIFIC AND CONUS...CONFIDENCE IN THE LONGER TERM PATTERN
EVOLUTION REMAINS LOW. A MASSIVE UPPER LOW/TROUGH IS EXPECTED
ACROSS EASTERN CANADA AND THIS WILL PROVIDE NORTHWEST FLOW INTO
THE GREAT LAKES...WHILE AN UPPER LOW OVER THE SOUTHWEST U.S. IS
ANTICIPATED TO SLOWLY WORK ITS WAY EAST. TOGETHER THESE SHOULD
DEVELOP A WEST-TO-EAST BAROCLINIC ZONE ACROSS THE MIDWEST THOUGH
WHERE AND HOW ACTIVE REMAINS HIGHLY UNCERTAIN ON MODELS. THIS ALSO
LEADS TO LOW CONFIDENCE IN TEMPERATURE FORECASTS AS A LARGE RANGE
IS LIKELY ACROSS THIS BOUNDARY. RIGHT NOW HAVE FAVORED A BLEND OF
THE EC/GFS/GEM...WHICH BRINGS THE BOUNDARY INTO THE AREA MONDAY
AND JUST SOUTH BY TUESDAY.
MTF
&&
.AVIATION...
FOR THE 12Z TAFS...
A STORM SYSTEM TO OUR WEST WILL LIFT A WARM FRONT NORTHWARD OVER
THE TERMINALS THIS EVENING. THIS WILL LIKELY RESULT IN OUR BEST
CHANCE FOR A PERIOD OF SHOWERS AND THUNDERSTORMS OVER NORTHERN
ILLINOIS/NORTHWESTERN INDIANA LATER TODAY INTO THIS EVENING. AS
SUCH...I HAVE CONTINUED TO FOCUS THE PRECIPITATION IN THE TAFS TO
HIT THE LATE AFTERNOON THROUGH EVENING HOURS WITH SHOWERS. WE
STILL CANNOT RULE OUT SOME THUNDERSTORMS DIRECTLY IMPACTING THE
TERMINALS AS WELL WITH THIS BATCH OF SHOWERS...AS A MID-LEVEL DRY
SLOT SHIFTING INTO THE REGION SHOULD HELP STEEPEN THE MID-LEVEL
LAPSE RATES. HOWEVER...WE STILL DONT HAVE HIGH ENOUGH CONFIDENCE
ON THE EXACT TIMING TO PLACE IN A TEMPO GROUP AT THIS TIME.
WINDS THROUGH THE DAY WILL REMAIN EAST-SOUTHEASTERLY...AND AGAIN
COULD BECOME A BIT GUSTY DURING THE DAY. AS THE WARM FRONT LIFTS
NORTHWARD THIS EVENING THE WINDS SHOULD BECOME SOUTH-SOUTHWESTERLY.
A PERIOD OF LOWER END MVFR/IFR CIGS MAY ALSO DEVELOP OVERNIGHT
TONIGHT FOLLOWING THE SHOWER ACTIVITY. CONFIDENCE ON THE EXTENT OF
THESE LOWER CIGS IS LOW AT THIS TIME...BUT ANY LOWER CIGS WOULD
IMPROVE QUICKLY THURSDAY MORNING.
KJB
&&
.MARINE...
228 AM CDT
A WEAK AREA OF LOW PRESSURE IS EXPECTED TO MOVE EASTWARD OVER LAKE
MICHIGAN ON THURSDAY. AS THIS LOW MOVES OVER THE LAKE...LIGHT
WINDS AND A MOIST AIR MASS COULD PRODUCE A PERIOD OF FOG OVER THE
LAKE. HOWEVER...NORTHERLY WINDS ARE EXPECTED TO INCREASE FROM
NORTH TO SOUTH OVER THE LAKE THURSDAY NIGHT INTO FRIDAY FOLLOWING
THE EASTWARD PASSAGE OF THE SURFACE LOW. THIS SHOULD RESULT IN A
PERIOD OF 30 KT NORTHERLY WINDS ON FRIDAY BEFORE WINDS ABATE
FRIDAY NIGHT AS A SURFACE RIDGE OF HIGH PRESSURE BUILDS OVER THE
UPPER GREAT LAKES. LARGE WIND WAVES...LIKELY IN EXCESS OF 5 FEET
ON SOUTHERN LAKE MICHIGAN WILL RESULT IN OUR NEXT PERIOD OF SMALL
CRAFT ADVISORY CONDITIONS FOR THE ILLINOIS AND INDIANA NEAR SHORE
WATERS.
OVER THE WEEKEND ANOTHER COLD FRONT IS EXPECTED TO SHIFT SOUTHWARD
DOWN LAKE MICHIGAN. THERE IS STILL UNCERTAINTY ON THE EXACT TIMING OF
THIS FRONT. HOWEVER...THERE ARE INDICATIONS THAT ANOTHER PERIOD OF
STRONGER NORTH-NORTHEASTERLY WINDS WILL SET UP OVER THE LAKE
POSSIBLY BY LATE SUNDAY OR MONDAY. THIS WILL BE ANOTHER PERIOD TO
WATCH FOR POSSIBLE SMALL CRAFT CONDITIONS ON THE NEAR SHORE WATERS
DUE TO WINDS AND HIGH WAVES.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE, IL
331 AM CDT WED APR 20 2016
.SHORT TERM...
329 AM CDT
THROUGH TONIGHT...
THIS AFTERNOON AND EVENING WILL BRING THE HIGHEST CHANCE FOR
SHOWERS IN THE FORECAST AREA IN TEN DAYS. WE HAVE KEPT THE MAIN
THEME OF RAIN TIMING BEING MID- AFTERNOON THROUGH EVENING
SPREADING FROM WEST TO EAST AND JUST REFINING THAT TO THE HOURLY
LEVEL. DID INCREASE THE THUNDER POTENTIAL SOME OVER THE ILLINOIS
PART OF THE CWA THOUGH THE RISK FOR SEVERE WEATHER REMAINS QUITE
LOW.
THE PERSISTENT LARGE UPPER LOW IS GYRATING ITS WAY SLOWLY EAST
THIS MORNING WITH ITS CENTER NOW OVER THE CENTRAL PLAINS. A 90 KT
UPPER JET ROUNDING THE SOUTHERN EDGE OF THIS CENTER AND ASSOCIATED
DEEP PV ANOMALY THIS MORNING WILL HELP RE-DEEPEN THE LOW CENTER BY
THIS EVENING OVER IOWA. UPPER FORCING AND ASSOCIATED LIFT IN
ADVANCE OF THIS...ALONG WITH A LOW-LEVEL RESPONSE OF THETA-E
ADVECTION...WILL SPREAD OVER ILLINOIS DURING THE AFTERNOON. GIVEN
THIS WILL BE DURING THE PEAK HEATING TIME...EXPECT THAT THERE WILL
BE AN INCREASE IN SHOWER AND STORM ACTIVITY...LIKELY JUST WEST OF
THE CWA ALONG THE SYSTEM COLD FRONT DURING THE EARLY TO MID
AFTERNOON AND SPREADING EAST FROM THERE. CONVECTIVE ALLOWING
MODELS SUCH AS THE HRRR INDICATE THIS INCREASE AND TIMING...THOUGH
HAVE VARIED QUITE A BIT FROM RUN-TO-RUN ON THE COVERAGE. A FEW
THINGS COULD INDEED LIMIT AFTERNOON SHOWER/STORM COVERAGE SUCH AS
THE NARROW NATURE OF THE DEEP MOIST PLUME WRAPPING NORTHWARD INTO
THIS SYSTEM. OVERALL THOUGH EXPECT THE AFOREMENTIONED FORCING JUST
AHEAD OF THE SYSTEM DRY SLOT TO BE ENOUGH TO PROVIDE AN UPTICK IN
SHOWERS DURING THE AFTERNOON INTO EARLY EVENING...WARRANTING
LIKELY WORDING IN THE FORECAST.
THE INSTABILITY MAGNITUDES /A FEW HUNDRED J/KG/ ARE BETTER FOR
THUNDER THAN PREVIOUS FORECAST CYCLES...MAINLY FOR THE NORTH
CENTRAL ILLINOIS PART OF THE FORECAST AREA. THE TIMING OF THE
MAIN SHOWER AND POSSIBLE THUNDERSTORM AREAS APPEAR TO BE EARLY
ENOUGH TO PREVENT DEEPER INSTABILITY RETURN TO LEVELS THAT WOULD
WARRANT A THREAT FOR SEVERE STORMS...THOUGH A FEW STRONG ONES WITH
MAYBE SOME SMALL HAIL ARE POSSIBLE INTO THE WESTERN CWA WITH
FREEZING LEVELS A LITTLE BELOW 10KFT.
IN TERMS OF TEMPERATURES...THE FRONTAL BOUNDARY WHICH BROUGHT A
30 DEGREE TEMPERATURE GRADIENT ACROSS THE CWA YESTERDAY...IS NOW
DRAPED OVER CENTRAL ILLINOIS TO SOUTHERN INDIANA. THIS WILL LIFT
NORTHWARD AS A WARM FRONT TODAY. THE FRONTAL PROGRESSION WILL
PROBABLY NOT BE FAR AHEAD OF RAIN SHOWER ACTIVITY WHICH MAKES THE
TEMPERATURE FORECAST CHALLENGING. NORTHERN AREAS WILL CERTAINLY BE
WARMER THAN YESTERDAY BUT HOW MUCH SO WILL DEPEND ON THE FRONTAL
PASSAGE TIMING. ONSHORE FLOW A GOOD PART OF THE DAY FROM CHICAGO
NORTHWARD WILL KEEP LAKESIDE TEMPERATURES COOLER AGAIN. FAR
SOUTHERN AREAS HAVE THE CHANCE AGAIN TO REACH UPPER 70S.
AS THE SYSTEM DRY SLOT WORKS OVERHEAD LATE THIS EVENING INTO
OVERNIGHT...THE SHOWER ACTIVITY WILL PUSH NORTHEAST. THE LOW-LEVEL
COOL ADVECTION WILL ACTUALLY WEAKEN GIVEN THE OVERALL OCCLUDED
NATURE OF THIS SYSTEM...SO LOWS LOOK TO REMAIN IN THE 50S
AREAWIDE.
MTF
&&
.LONG TERM...
329 AM CDT
THURSDAY THROUGH TUESDAY...
THE PRIMARY UPPER LOW WILL GRADUALLY TRANSITION INTO AN OPEN WAVE
THROUGH THURSDAY AND THURSDAY NIGHT AND SHOULD DO SO AS IT TRACKS
EASTWARD OVER THE FORECAST AREA. WHILE DRY AIR ALOFT WILL PREVENT
MUCH FOR SHOWERS THURSDAY MORNING...MOST MODEL GUIDANCE INDICATES
THE FORECAST AREA TO BE IN A FAVORABLE AREA OF UPPER SUPPORT TO AT
LEAST SEE AFTERNOON AND EARLY EVENING SCATTERED SHOWERS AND EVEN A
FEW STORMS AGAIN. WITH TEMPERATURES THURSDAY AFTERNOON WARMING
BACK INTO THE MID 60S TO LOW 70S...THERE SHOULD BE A FEW HUNDRED
J/KG OF CAPE TO WORK WITH. LOWER FREEZING LEVELS COULD PROVIDE A
FEW SMALL HAIL PRODUCERS.
BEHIND THIS TROUGH FRIDAY AND SATURDAY CONTINUE TO LOOK DRY. STOUT
NORTHEAST WINDS ON FRIDAY WILL KEEP LAKESHORE HIGHS INCLUDING
DOWNTOWN CHICAGO LIKELY SHY OF 50 DEGREES. INLAND AREAS ARE
PRESENTLY FORECAST FOR HIGHS IN THE UPPER 50S/LOWER 60S...ALTHOUGH
THIS WILL DEPEND ON CLOUDS CLEARING FRIDAY MORNING.
GIVEN THE PRESENT AMPLIFIED/SEMI-BLOCKED PATTERN ACROSS THE
EASTERN PACIFIC AND CONUS...CONFIDENCE IN THE LONGER TERM PATTERN
EVOLUTION REMAINS LOW. A MASSIVE UPPER LOW/TROUGH IS EXPECTED
ACROSS EASTERN CANADA AND THIS WILL PROVIDE NORTHWEST FLOW INTO
THE GREAT LAKES...WHILE AN UPPER LOW OVER THE SOUTHWEST U.S. IS
ANTICIPATED TO SLOWLY WORK ITS WAY EAST. TOGETHER THESE SHOULD
DEVELOP A WEST-TO-EAST BAROCLINIC ZONE ACROSS THE MIDWEST THOUGH
WHERE AND HOW ACTIVE REMAINS HIGHLY UNCERTAIN ON MODELS. THIS ALSO
LEADS TO LOW CONFIDENCE IN TEMPERATURE FORECASTS AS A LARGE RANGE
IS LIKELY ACROSS THIS BOUNDARY. RIGHT NOW HAVE FAVORED A BLEND OF
THE EC/GFS/GEM...WHICH BRINGS THE BOUNDARY INTO THE AREA MONDAY
AND JUST SOUTH BY TUESDAY.
MTF
&&
.AVIATION...
FOR THE 06Z TAFS...
A STORM SYSTEM TO OUR WEST WILL LIFT A WARM FRONT NORTHWARD OVER
THE TERMINALS BY THIS EVENING. THIS WILL LIKELY RESULT IN OUR BEST
CHANCE FOR A PERIOD OF SHOWERS AND SOME THUNDERSTORMS OVER
NORTHERN ILLINOIS/NORTHWESTERN INDIANA LATER TODAY INTO THIS
EVENING. AS SUCH...I HAVE TWEAKED THE TIMING OF THE PRECIPITATION
IN THE TAFS TO HIT THE LATE AFTERNOON THROUGH MID EVENING HOURS
WITH SHOWERS. WE ALSO CANNOT RULE OUT SOME THUNDERSTORMS AS WELL
WITH THIS BATCH OF SHOWERS...AS A MID-LEVEL DRY SLOT SHIFTING
INTO THE REGION SHOULD HELP STEEPEN THE MID-LEVEL LAPSE RATES. AT
THIS TIME I HAVE OPTED TO HOLD OFF INCLUDING THE THUNDER IN A
TEMPO...BUT THE BEST CHANCES OF THUNDER WOULD LIKELY FALL IN THE
CURRENT 00-03 UTC (22-01 UTC) TEMPO GROUPS AT THE EASTERN (KRFD)
TAF SITES.
WINDS THROUGH THE DAY WILL REMAIN EAST-SOUTHEASTERLY...AND AGAIN
COULD BECOME A BIT GUSTY DURING THE DAY. AS THE WARM FRONT LIFTS
NORTHWARD THIS EVENING THE WINDS SHOULD BECOME SOUTH-SOUTHWESTERLY.
A PERIOD OF MVFR CIGS COULD ALSO ACCOMPANY THE WARM FRONTAL
BOUNDARY.
KJB
&&
.MARINE...
228 AM CDT
A WEAK AREA OF LOW PRESSURE IS EXPECTED TO MOVE EASTWARD OVER LAKE
MICHIGAN ON THURSDAY. AS THIS LOW MOVES OVER THE LAKE...LIGHT
WINDS AND A MOIST AIR MASS COULD PRODUCE A PERIOD OF FOG OVER THE
LAKE. HOWEVER...NORTHERLY WINDS ARE EXPECTED TO INCREASE FROM
NORTH TO SOUTH OVER THE LAKE THURSDAY NIGHT INTO FRIDAY FOLLOWING
THE EASTWARD PASSAGE OF THE SURFACE LOW. THIS SHOULD RESULT IN A
PERIOD OF 30 KT NORTHERLY WINDS ON FRIDAY BEFORE WINDS ABATE
FRIDAY NIGHT AS A SURFACE RIDGE OF HIGH PRESSURE BUILDS OVER THE
UPPER GREAT LAKES. LARGE WIND WAVES...LIKELY IN EXCESS OF 5 FEET
ON SOUTHERN LAKE MICHIGAN WILL RESULT IN OUR NEXT PERIOD OF SMALL
CRAFT ADVISORY CONDITIONS FOR THE ILLINOIS AND INDIANA NEAR SHORE
WATERS.
OVER THE WEEKEND ANOTHER COLD FRONT IS EXPECTED TO SHIFT SOUTHWARD
DOWN LAKE MICHIGAN. THERE IS STILL UNCERTAINTY ON THE EXACT TIMING OF
THIS FRONT. HOWEVER...THERE ARE INDICATIONS THAT ANOTHER PERIOD OF
STRONGER NORTH-NORTHEASTERLY WINDS WILL SET UP OVER THE LAKE
POSSIBLY BY LATE SUNDAY OR MONDAY. THIS WILL BE ANOTHER PERIOD TO
WATCH FOR POSSIBLE SMALL CRAFT CONDITIONS ON THE NEAR SHORE WATERS
DUE TO WINDS AND HIGH WAVES.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE, IL
1252 AM CDT WED APR 20 2016
.UPDATE...
855 PM CDT
FRONTAL BOUNDARY BEGAN TO SAG SOUTH ACROSS NORTHERN IL/NORTHWEST
IN EARLIER TODAY AND RESULTED IN A WIND SHIFT FROM THE
SOUTH/SOUTHWEST TO NORTH/NORTHEAST...COUPLED WITH MUCH COOLER AIR
FLOWING INTO NORTHERN IL. TEMPERATURES QUICKLY FELL INTO THE
LOW/MID 50S...MEANWHILE SOUTH OF THE BOUNDARY TEMPERATURES WERE
HOLDING IN THE 70S. THE BOUNDARY HAS PUSHED SOUTH OF THE FORECAST
AREA INTO CENTRAL IL TONIGHT...AND IS EXPECTED TO BECOME
STATIONARY OVERNIGHT. SCATTERED SHOWERS ACROSS NORTHWEST IL HAVE
STEADILY DIMINISHED IN COVERAGE AND INTENSITY...AND LATEST HI-RES
FORECAST GUIDANCE CONTINUES TO LEAN TOWARDS PRECIP COMING TO AN
END OVERNIGHT THROUGH DAYBREAK WED. WITH HIGH PRESSURE POSITIONED
OVER LOWER MICHIGAN TO JAMES BAY...THIS MAY ALLOW FOR SOME POCKETS
OF DRIER AIR AND LESS CLOUD COVER OVERNIGHT...BUT ANY BREAKS WILL
BE SHORT LIVED.
A WEAK SHORT WAVE IS PROGGED TO DEVELOP OVER THE CENTRAL PLAINS
LATE TONIGHT AND WILL HELP TO ENERGIZE THE FRONTAL
BOUNDARY...LIFTING THE BOUNDARY BACK NORTH WEDNESDAY AND BRINGING
AN INCREASING CHANCE FOR PRECIP BY MID-MORNING. TIMING OF THE
FRONTAL BOUNDARY WED WILL DICTATE HIGH TEMPS...BUT CURRENTLY
EXPECTING HIGHS TO PUSH BACK INTO THE UPPER 60S TO LOW 70S. THE
BETTER CHANCE FOR SHOWERS AND POSSIBLY THUNDERSTORMS WILL ARRIVE
IN THE WED AFTERNOON TIMEFRAME.
BEACHLER
&&
.SHORT TERM...
236 PM CDT
THROUGH TODAY...
FOR THE REMAINDER OF THE AFTERNOON AND INTO THE EVENING...THE MAIN
FOCUS WILL BE PCPN EXTENT AND TEMPERATURE DISTRIBUTION.
AS OF 230PM CDT...WITH A WEAK TROUGH OF LOW PRESSURE ACROSS THE
MISSOURI VALLEY AND STRONG HIGH PRESSURE OVER THE UPPER GREAT
LAKES...ALONG WITH A WEAK FRONTAL BOUNDARY ROUGHLY ALONG THE
ILLINOIS AND KANKAKEE RIVER VALLEYS...THERE HAS BEEN QUITE A SPREAD
IN TEMPERATURES ACROSS THE REGION. WITH PREVAILING NORTHEASTERLY
FLOW OFF OF THE COOL WATERS OF LAKE MICHIGAN NORTH OF THE
BOUNDARY...AND SOUTHERLY FLOW TO THE SOUTH...TEMPERATURES ACROSS THE
SOUTHERN PORTIONS OF THE CWA ARE IN THE MIDDLE TO UPPER 70S...WITH
SOME LOCATIONS POSSIBLY SEE 80F AGAIN TODAY. HOWEVER...NORTH OF THE
BOUNDARY...TEMPERATURES ARE MUCH LOWER...WITH HIGHS TODAY TOPPING
OUT ONLY IN THE LOWER 50S. A FEW LAKEFRONT LOCATIONS MAY ONLY SEE
TEMPS REACH THE UPPER 40S. PERSISTENT RAIN HAS BEEN FALLING OVER
MUCH OF NWRN IL...WITH THE MOST WIDESPREAD RAIN INVOF A VORT MAX
SLOWLY LIFTING NEWD. EXPECT THAT THE VORT WILL EVENTUALLY LIFT
INTO WISCONSIN AND PCPN CHANCES SHOULD DIMINISH THROUGH THE NIGHT.
WHILE THERE WILL STILL BE SOME RESIDUAL CHANCE FOR SOME SHOWERS
OVERNIGHT
...ESPECIALLY WEST OF THE I-39 CORRIDOR...NERN IL AND NWRN IN SHOULD
REMAIN DRY. HOWEVER...THERE IS A CHANCE FOR AN ISOLD SHOWER THROUGH
THIS EVENING OVER THE CHICAGO METRO AREA. WITH A RELATIVELY MOIST
AIRMASS AND THICK CLOUD COVER EXPECTED TO REMAIN IN PLACE
OVERNIGHT...TEMPERATURES SHOULD REMAIN RELATIVELY MILD. OVERNIGHT
LOWS ACROSS THE AREA SHOULD RANGE FROM THE UPPER 50S OVER THE
PONTIAC METRO AREA TO THE UPPER 40S TO LOWER 50S OVER THE
REMAINDER OF THE AREA.
KREIN
&&
.LONG TERM...
308 PM CDT
WEDNESDAY THROUGH FRIDAY...
LINGERING SHOWER CHANCES WILL REMAIN WEDNESDAY MORNING PRIMARILY
ACROSS NORTHERN ILLINOIS...WHILE WEAK ENERGY CONTINUES TO LIFT
NORTH OUT AHEAD OF APPROACHING LARGE UPPER LEVEL SYSTEM OVER THE
PLAINS. HOWEVER...COVERAGE/DURATION WILL REMAIN LOW WITH THIS WEAK
ASCENT...AND SO HAVE KEPT POPS LOW DURING THIS TIME. SLOWLY
INCREASE POPS THROUGH MIDDAY AND EARLY AFTERNOON WEDNESDAY AS THIS
SYSTEM WORKS ITS WAY EAST AND WHILE STRONGER ENERGY WRAPS AROUND
THIS SYSTEM. THIS WILL OCCUR AS FRONTAL BOUNDARY LIFTS NORTH
THROUGH THE CWA AND WITH DEWPOINTS REBOUNDING BACK INTO THE 50S.
THIS SHOULD ALLOW COVERAGE OF SHOWERS TO INCREASE OVER MUCH OF
NORTHERN ILLINOIS...ESPECIALLY BY THE LATE AFTERNOON TIME FRAME.
INSTABILITY WILL INCREASE DURING THE AFTERNOON BUT WILL REMAIN ON
THE LOW SIDE. HOWEVER...WITH INCREASING FORCING ALOFT...DO THINK
THUNDERSTORM CHANCES WILL REMAIN. DO THINK TEMPS WILL REBOUND
ACROSS THE CWA ON WEDNESDAY WITH BOUNDARY LIFTING NORTH...SO
RAISED HIGH TEMPS WITH MOST LOCATIONS GETTING INTO THE UPPER 60S
WITH THE EXCEPTION OF AREAS NEAR THE LAKE IN NORTHEAST ILLINOIS.
PUSH OF PRECIP WEDNESDAY AFTERNOON WILL CONTINUE TO LIFT
NORTHEAST THROUGH THE EARLY EVENING AS THIS ENERGY PUSHES THROUGH.
SYSTEM WILL BECOME MORE STACKED DURING THE NIGHT WITH THE SURFACE
LOW WEAKENING AS IT MOVES INTO THE CWA LATE WEDNESDAY NIGHT INTO
THURSDAY MORNING. THIS SHOULD ALLOW FOR COVERAGE OF ANY PRECIP TO
LOWER WITH A DRY PERIOD POSSIBLE FOR MOST AREAS. HOWEVER...THIS
UPPER LEVEL TROUGH WILL QUICKLY OPEN UP AS IT SWINGS THROUGH THE
CWA ON THURSDAY. LINGERING HIGHER DEWPOINTS ALONG SURFACE TROUGH
AXIS WITH THIS ADDITIONAL FORCING WILL ALLOW FOR ADDITIONAL
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS TO DEVELOP BY LATE
THURSDAY MORNING INTO THE AFTERNOON. GIVEN THE ANTICIPATED
COVERAGE AT THIS TIME DID NOT RAISE POPS TOO HIGH...BUT COULD SEE
THEM RAISED FURTHER WITH LATER FORECASTS. THIS PRECIP IS EXPECTED
TO DIMINISH AS IT EXITS TO THE EAST THURSDAY EVENING WITH THE
DEPARTURE OF THIS SYSTEM. DID LEAVE A SLIGHT CHANCE FOR SHOWERS
THURSDAY NIGHT AS SOME ISOLATED DEVELOPMENT COULD OCCUR ALONG
SOUTHWARD DRIFTING BOUNDARY. BUILDING HIGH PRESSURE WILL THEN
BRING PERIOD OF DRY WEATHER TO THE AREA FRIDAY.
FRIDAY NIGHT THROUGH TUESDAY...
QUIET AND NEAR TO SLIGHTLY ABOVE LATE APRIL NORMAL TEMPERATURES
WILL BE IN STORE TO START THE WEEKEND. EXPECTING HIGHS IN THE MID
TO UPPER 60S INLAND ON SATURDAY. WITH HIGH PRESSURE
NEARBY...WINDS SHOULD STAY ONSHORE FOR AT LEAST THE ILLINOIS
SHORE KEEPING TEMPERATURES IN THE 50S THERE.
ATTENTION WILL THEN TURN TO A MID/UPPER TROUGH EJECTING INTO
THE CENTRAL AND NORTHERN PLAINS ON SUNDAY AND SHEARING OUT EARLY
NEXT WEEK. THE ASSOCIATED SURFACE LOW FROM THIS TROUGH WILL HAVE
A QUASI-STATIONARY FRONTAL BOUNDARY EXTENDING EASTWARD FROM IT
SUNDAY AND MONDAY UNTIL THE BOUNDARY POTENTIALLY SHIFTS SOUTH OF
THE AREA BY TUESDAY. THIS WILL HAVE AN IMPACT ON OUR SENSIBLE
WEATHER CONDITIONS WITH RESPECT TO TEMPERATURES AND PRECIPITATION
CHANCES. A DISTURBANCE RIDING OVER THE TOP OF THE MID/UPPER RIDGE
OVER THE AREA COULD RESULT IN PRECIP CHANCES RETURNING LATE
SATURDAY NIGHT INTO SUNDAY. THEN CONVERGENCE ALONG THE QUASI-
STATIONARY FRONT AND ADDITIONAL WAVES EMANATING FROM THE
WEAKENING TROUGH COULD BRING A FEW ADDITIONAL ROUNDS OF SHOWERS
INTO MONDAY AND A FINAL WAVE NORTH OF THE SOUTHWARD SINKING FRONT
ON TUESDAY. MAINTAINED CHANCE POPS FROM BLENDED INITIALIZATION.
DESPITE SEVERAL PERIODS OF PRECIP CHANCES...IT DOES NOT APPEAR
LIKELY TO BE A WASHOUT. THE BEST INSTABILITY AXIS WILL REMAIN
PRIMARILY TO OUR SOUTH AND WEST...THOUGH OCCASIONAL ISOLATED
THUNDERSTORMS ARE POSSIBLE IN THE SOUTHWESTERN 1/3 OR 1/4 OF THE
CWA.
THE POSITION OF THE FRONT WILL DETERMINE WHETHER MOST OR ALL OF
THE LAKESHORE RECEIVES PERSISTENT ONSHORE FLOW LATER SUNDAY
AND MONDAY...BUT AT LEAST THE IL SHORE WILL LIKELY BE MUCH COOLER
THAN INLAND AREAS. AFTER TEMPERATURES LIKELY WELL INTO THE 60S
AND EVEN 70S INLAND ON SUNDAY AND MONDAY...TEMPERATURES WILL COOL
BACK TO SEASONABLE FOR LATE APRIL TUESDAY...AND EVEN COOLER FOR
THE SHORE DUE TO ONSHORE WINDS.
RODRIGUEZ/RC
&&
.AVIATION...
FOR THE 06Z TAFS...
A STORM SYSTEM TO OUR WEST WILL LIFT A WARM FRONT NORTHWARD OVER
THE TERMINALS BY THIS EVENING. THIS WILL LIKELY RESULT IN OUR BEST
CHANCE FOR A PERIOD OF SHOWERS AND SOME THUNDERSTORMS OVER
NORTHERN ILLINOIS/NORTHWESTERN INDIANA LATER TODAY INTO THIS
EVENING. AS SUCH...I HAVE TWEAKED THE TIMING OF THE PRECIPITATION
IN THE TAFS TO HIT THE LATE AFTERNOON THROUGH MID EVENING HOURS
WITH SHOWERS. WE ALSO CANNOT RULE OUT SOME THUNDERSTORMS AS WELL
WITH THIS BATCH OF SHOWERS...AS A MID-LEVEL DRY SLOT SHIFTING
INTO THE REGION SHOULD HELP STEEPEN THE MID-LEVEL LAPSE RATES. AT
THIS TIME I HAVE OPTED TO HOLD OFF INCLUDING THE THUNDER IN A
TEMPO...BUT THE BEST CHANCES OF THUNDER WOULD LIKELY FALL IN THE
CURRENT 00-03 UTC (22-01 UTC) TEMPO GROUPS AT THE EASTERN (KRFD)
TAF SITES.
WINDS THROUGH THE DAY WILL REMAIN EAST-SOUTHEASTERLY...AND AGAIN
COULD BECOME A BIT GUSTY DURING THE DAY. AS THE WARM FRONT LIFTS
NORTHWARD THIS EVENING THE WINDS SHOULD BECOME SOUTH-SOUTHWESTERLY.
A PERIOD OF MVFR CIGS COULD ALSO ACCOMPANY THE WARM FRONTAL
BOUNDARY.
KJB
&&
.MARINE...
324 PM CDT
EAST-NORTHEAST WINDS OVER THE LAKE TODAY WILL TURN SOUTHEAST ON
THE SOUTHERN PART OF THE LAKE ON WEDNESDAY AS A FRONTAL BOUNDARY
LIFTS NORTH. EXPECT A PERIOD OF SOUTHERLY WINDS ON THURSDAY AS
THE FRONT LIFTS FARTHER NORTH. BY THURSDAY NIGHT...A STRONGER
COLD FRONT WILL PUSH SOUTH...RESULTING IN A PERIOD OF STRONGER
NORTHERLY WINDS INTO FRIDAY. GUSTS WILL LIKELY BE IN THE 25-30 KT
RANGE. THE NORTHERLY WINDS AND BUILDING WAVES WILL LIKELY
NECESSITATE A SMALL CRAFT ADVISORY FRIDAY INTO FRIDAY EVENING FOR
THE ILLINOIS AND INDIANA NEARSHORE WATERS. HIGH PRESSURE WILL
BRING FAIRLY LIGHT WINDS FOR THE WHOLE LAKE ON SATURDAY.
THEREAFTER...A QUASI-STATIONARY FRONT WILL EXTEND EAST FROM A
SURFACE LOW OVER THE PLAINS SUNDAY AND MONDAY...WITH MOST OF THE
OPEN WATER AREA LIKELY NORTH OF THE FRONT RESULTING IN MODERATE
EASTERLY WINDS. DIRECTIONS COULD BE VARIABLE FOR THE NEARSHORE AND
FAR SOUTHERN OPEN WATERS DEPENDING ON THE POSITION OF THE FRONT.
THE FRONT WILL SAG WELL SOUTH OF THE LAKE ON TUESDAY...CAUSING
NORTHEAST WINDS FOR THE WHOLE LAKE.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1130 PM CDT TUE APR 19 2016
.UPDATE...
Issued at 827 PM CDT Tue Apr 19 2016
Convection over central Illinois since late afternoon has been
most numerous just west of the Illinois River, with scattered
thunderstorms and heavier rains at times. Showers have occurred
as far east as Springfield, but this has been fading as of late.
Overall trend in our forecast area has been for a decreasing
trend over the last couple hours, with mainly light rains left
from about Peoria-Springfield westward.
Latest surface map showing the frontal boundary roughly along the
I-72 corridor back into central Missouri where additional
thunderstorms are occurring, and a gradual northward shift is
expected later tonight. The current HRRR and earlier high-
resolution NMM/ARW models have been significantly easing up on the
precipitation this evening and are largely dry overnight. Have
made some significant adjustments to the PoP trends to back off on
the rain chances after midnight as a result.
&&
.SHORT TERM...(Tonight)
ISSUED AT 314 PM CDT Tue Apr 19 2016
Large upper level low over the western half of the country is not
making much progress, nor is much eastern progression expected in
the overnight. With some weak lift over the area and several weak
boundaries in the vicinity...some rain chances cannot be ruled out
around sunset in the west... as well as increasing slight chances
after midnight for much of Central Illinois. At least initially
tonight, the rainfall should remain scattered and more showery in
nature. The deep low over the western half of the county has much
of the northern half of IL and WI in a weak flow pattern as
well...winds should remain somewhat light and variable through the
overnight hours with some trend to southeasterly. Showers are
expected to begin spreading in coverage at least after
midnight...but confidence for any one location is small with the
slowing system.
.LONG TERM...(Wednesday through Tuesday)
ISSUED AT 314 PM CDT Tue Apr 19 2016
Shorter range models are generally in agreement with their strength
and timing of moving the closed upper low in the High Plains toward
the mid-MS Valley by early Thursday. The GFS is a little quicker and
a little farther south than the other models but overall their
solutions are fairly similar, particularly the NAM and European.
Scattered showers and isolated thunderstorms early Wed morning
should give way to more widespread coverage of rainfall from later
in the morning through the early evening. With deep moisture taking
awhile to increase most of the rain accumulation will be on the
lighter side. However, the best moisture, but with limited
instability, will focus in the warm sector ahead of the cold front
Wednesday afternoon into the evening. This will coincide with the
highest PoPs and the vast majority of the QPF. Due to the limited
instability will stick with isolated thunder through the shorter
range.
The upper level trough axis from the lifting upper level low is
expected to pass through central IL early Thursday and eastern IL
Thursday evening. This will bring a gradual end to the showers and
isolated thunderstorms from west to east during the day Thursday. A
secondary shortwave trough rotating through Great Lakes toward the
upper Ohio Valley Friday could keep a few lingering showers south of
I-70, otherwise a decreasing cloud trend and temperatures typical
for later April in the mid-upper 60s can be expected.
A piece of an upper level ridge over the western U.S. will flatten
and get pushed east toward our region for early in the weekend. Dry
weather with temperatures in the lower 70s can be expected on
Saturday as a result. Things get a bit more complicated for Sunday
into early next week as a series of vigorous upper level troughs
move from the western U.S. toward the Plains and Midwest. In
addition, a large upper trough in eastern Canada will move little,
resulting in the approaching energy being sheared eastward across
the Great Lakes. The resulting upper flow across area would be from
the WSW, which means that frontal boundaries could lay out from west
to east in the vicinity of Illinois. This would result in an
unsettled period of weather with slightly warmer than normal
temperatures by early next week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1130 PM CDT Tue Apr 19 2016
Some lingering showers were west of KPIA but moving northwest, so
general overnight theme will be for dry conditions and VFR
ceilings generally above 9000 feet. Have even seen some fairly
extensive clearing near KCMI which will result in ceilings
scattering out at times.
Frontal boundary roughly along a KUIN-KDNV line at 05Z will start
to lift northward later tonight, with winds trending more
southeast toward sunrise. Ceilings will be steadily decreasing
after 12Z as an area of showers sweeps across central Illinois.
Low VFR conditions expected to accompany these showers late
morning and early afternoon. Additional showers and storms will
advance out of Missouri in the afternoon ahead of a cold front,
and have added VCTS mention to all TAF sites late afternoon and
early evening. Ceilings expected to fall into MVFR range early
afternoon ahead of the second area of showers/storms. Ceilings
will rise in the evening immediately behind the passage of the
front itself, with KPIA/KSPI most likely to see this before the
end of the forecast period.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Geelhart
SHORT TERM...HJS
LONG TERM...Miller
AVIATION...Geelhart
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
858 PM EDT THU APR 21 2016
.SYNOPSIS...
ISSUED AT 334 PM EDT THU APR 21 2016
SHOWERS AND A FEW THUNDERSTORMS WILL IMPACT THE REGION INTO
TONIGHT. SEVERE WEATHER IS NOT EXPECTED AT THIS TIME...BUT THE
STRONGEST STORMS COULD PRODUCE SMALL HAIL AND LOCALIZED GUSTY
WINDS THROUGH THIS EVENING. RAIN CHANCES WILL LINGER INTO FRIDAY
MAINLY ALONG AND SOUTHEAST OF INTERSTATE 69. LOWS TONIGHT IN THE
MID 40S TO MID 50S. HIGHS ON FRIDAY WILL GENERALLY BE IN THE
UPPER 50S TO MIDDLE 60S AWAY FROM LAKE MICHIGAN...WITH COOL
ONSHORE FLOW LEADING TO HIGHS ONLY AROUND 50.
&&
.UPDATE...
ISSUED AT 804 PM EDT THU APR 21 2016
LEAD VORT MAX WILL CONTINUE TO SHIFT ACROSS NORTHWEST OHIO OVER
THE NEXT HOUR OR TWO. EXTENT/INTENSITY OF THUNDER HAS DIMINISHED
WITH THIS AREA OF RAIN OVER THE PAST FEW HOURS AS FORCING WITH
THIS VORT MAX HAS OUTRUN BETTER INSTABILITY. ADDITIONAL SCATTERED
STORMS HAVE DEVELOPED ACROSS WESTERN PORTIONS OF THE FORECAST AREA
EARLY THIS EVENING COINCIDENT WITH PRIMARY 500-1000 J/KG
INSTABILITY AXIS. INSTABILITY SHOULD BECOME PROGRESSIVELY MORE
ELEVATED OVER NEXT SEVERAL HOURS WHICH SHOULD RESULT IN DOWNWARD
TREND OF CONVECTIVE INTENSITY. STILL SOME LOW END POTENTIAL OF
SOME SMALL HAIL/LOCALIZED WIND GUSTS IN EXCESS OF 40 MPH WITH
STRONGER CORES ACROSS MAINLY WESTERN HALF OF THE FORECAST AREA
THROUGH 03Z HOWEVER. WILL KEEP LIKELY RAIN/CHANCE THUNDER MENTION
GOING THROUGH THE EVENING WITH HIGHEST POPS IN THE SOUTH DUE TO
DIGGING NATURE OF APPROACHING UPPER TROUGH. POCKET OF STEEPER MID
LEVEL LAPSE RATES ADVECTING INTO THE AREA ACCOMPANYING THIS
FEATURE SHOULD PROLONG ISOLD THUNDER POTENTIAL INTO THE OVERNIGHT
HOURS...AND MAINLY ACROSS THE SOUTH/SOUTHEAST. ONLY TWEAK FOR THE
EVENING UPDATE WAS TO REFINE POPS FOR CURRENT TRENDS BUT OTHER
FORECAST ELEMENTS APPEAR TO BE ON TRACK.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 334 PM EDT THU APR 21 2016
MAIN FOCUS ON CONVECTIVE DEVELOPMENT IN FAR WESTERN PARTS OF
FORECAST AREA AS WELL AS UPSTREAM NEAR THE UPPER LOW.
SOME POCKETS OF CLEARING/BREAKS HAVE OCCURRED ALLOWING TEMPERATURES
TO CLIMB INTO THE 60S ACROSS THE AREA AND MAKING A RUN AT 70 IN
WEST/SW LOCATIONS. NARROW PLUME OF HIGHER DEWPOINTS WAS NOW SHIFTING
ACROSS THE FORECAST AREA WITH SLIGHTLY LOWER READINGS UNDER THE
CLEARING AND WHERE CONVECTION WAS ATTEMPTING TO POP. ISOLATED
SHOWERS/STORMS HAVE BEEN DEVELOPING OVER THE LAST 30 TO 60
MINUTES...LIKELY CONTAINING AT LEAST SOME SMALL HAIL. ARC OF STORMS
ONGOING CLOSER TO THE UPPER LOW FROM WATERLOO IOWA TO MOLINE TO WEST
OF SPRINGFIELD IL. HRRR SUGGESTS THIS ACTIVITY WILL MOVE SLOWLY
NORTHEAST AND EXPAND MORE IN THE 22 TO 02Z WINDOW. HAVE KEPT HIGH
SCT TO NUMEROUS SHOWERS WITH MENTION OF THUNDER THROUGH THE EVENING.
EVE SHIFT MAY NEED TO ADJUST FOR TRENDS. TEMPERATURES WILL SLOWLY
FALL THIS EVENING AS AREA REMAINS IN THE WARM SECTOR...WITH SLOW
FALL OVERNIGHT AS THE COLD FRONT APPROACHES.
UPPER LOW WILL CONTINUE TO OPEN AND LINGER FRIDAY...ONLY DRIFTING
SLOWLY EAST INTO SOUTHERN OHIO BY 00Z SAT. GIVEN UPSTREAM TRENDS
UNDER THE UPPER LOW WITH SCATTERED SHOWERS AROUND...SEE NO REASON TO
MAKE ANY MAJOR CHANGES TO SE HALF OF THE AREA INTO MID AFTERNOON
WITH SCATTERED SHOWERS. WHILE NOT INTRODUCED...MAY NEED TO ADD
PASSING MENTION OF THUNDER AS SFC CAPE INCREASES TO AROUND 500 J/KG
AND MARGINAL LAPSE RATES.
&&
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 334 PM EDT THU APR 21 2016
A MORE PROGRESSIVE FLOW PATTERN WILL TAKE HOLD ON THE LOWER 48 THIS
WEEKEND INTO NEXT WEEK AS A SERIES OF WESTERN CONUS SHORTWAVES
EJECT/SHEAR EAST INTO MORE CONFLUENT/WNW FLOW OVER THE GREAT LAKES
REGION. LUCKILY THE WEEKEND WILL FEATURE DRY CONDITIONS WITH HIGH
PRESSURE IN CONTROL IN BETWEEN WAVES. SATURDAY THE COOLER/SUNNIER
DAY UNDER HIGH PRESSURE WITH WARM ADVECTION BEHIND SFC HIGH ALLOWING
HIGHS TO RETURN INTO THE 70S BY SUNDAY. FRONTAL SYSTEMS WITH THE
AFOREMENTIONED SHORTWAVES THEN BRING MORE UNSETTLED WX NEXT
WEEK...WITH LATEST GUIDANCE FAVORING MONDAY/MONDAY NIGHT AND
WEDNESDAY/WEDNESDAY NIGHT FOR HIGHER POPS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 804 PM EDT THU APR 21 2016
THE INITIAL WAVE OF SHOWERS AND THUNDERSTORMS EARLY THIS EVENING
HAS SHIFTED EAST OF TERMINALS IN ASSOCIATION WITH SHORT WAVE
EMANATING FROM MAIN UPPER LOW STILL TO THE WEST OF THE AREA.
ADDITIONAL SHOWERS AND STORMS HAVE DEVELOPED ACROSS NORTHWEST
INDIANA DOWNSTREAM OF THIS UPPER LOW...AND SHOULD CONTINUE TO
OVERSPREAD TERMINALS OVER THE NEXT FEW HOURS. INSTABILITY SHOULD
BECOME MORE ELEVATED IN NATURE OVER THE NEXT FEW HOURS RESULTING
IN A GRADUAL DIMINISHMENT IN THUNDER COVERAGE AFTER 03Z. HAVE HELD
OFF ON THUNDER INCLUSION FOR THE 00Z TAFS BUT WILL CONTINUE TO
MONITOR SHORT TERM TRENDS FOR POSSIBLE BRIEF INCLUSION THIS
EVENING. OUTSIDE OF HEAVIER PRECIP CORES...VFR CONDITIONS SHOULD
HOLD THROUGH THE EVENING WITH DETERIORATING CONDITIONS EXPECTED
OVERNIGHT INTO EARLY FRIDAY MORNING AS SFC LOW PRESSURE/COLD FRONT
TRACKS ACROSS THE AREA. IFR CONDITIONS ARE POSSIBLE LATE TONIGHT
INTO EARLY FRIDAY WITH GREATEST POTENTIAL AT KSBN. CIGS BELOW FUEL
ALTERNATE CRITERIA ARE EXPECTED INTO FRIDAY MORNING...BEFORE SOME
IMPROVEMENT FOR FRIDAY. MAY NEED TO INCREASE DURATION OF RAIN
SHOWER MENTION AT KFWA INTO FRIDAY WITH UPPER LEVEL LOW SLOW TO
DEPART THE AREA...AND SOME DIURNAL REGENERATION OF SHOWERS
POSSIBLE.
&&
.MARINE...
WEBCAMS SHOWING A GOOD DEAL OF DENSE FOG IN THE NEARSHORE WATERS
WARRANTING ISSUANCE OF A MARINE DENSE FOG ADVISORY INTO THIS
EVENING UNTIL COLDER AIR STARTS TO MOVE IN. WILL ALSO HOIST SMALL
CRAFT ADVISORY FOR FRIDAY INTO FRIDAY EVENING FOR INCREASING NW
FLOW AND HIGHER WAVES.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...DENSE FOG ADVISORY UNTIL 2 AM EDT FRIDAY FOR LMZ043-046.
SMALL CRAFT ADVISORY FROM 8 AM FRIDAY TO 2 AM EDT SATURDAY FOR
LMZ043-046.
&&
$$
UPDATE...MARSILI
SYNOPSIS...FISHER
SHORT TERM...FISHER
LONG TERM...STEINWEDEL
AVIATION...MARSILI
MARINE...FISHER
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Area Forecast Discussion
National Weather Service Paducah KY
1052 PM CDT THU APR 21 2016
.SHORT TERM...(Tonight through Saturday night)
Issued at 210 PM CDT Thu Apr 21 2016
Precipitation lingered in the eastern portions of the area
(Pennyrile region of west KY/parts of southwest IN) all morning.
Some additional development occurred back to the west of that
activity from near Paducah to Evansville up to Pike County IN. By
early afternoon, some isolated convection started flaring up over
S. IL. Hardly any lightning with any of this activity but hail may
occur.
The upper level low, clearly seen in water vapor loop over central
Iowa this morning, moved into southern IA/northern MO this
afternoon. This low will move into western IL by 00Z this evening
and into central IL later tonight. As this occurs...we will continue
to see the chances for showers and some thunderstorms through
tonight, as the main trough pivots over our region and better
moisture becomes available. Freezing levels are pretty low, so
some of the storms could produce some hail. Looking at the latest
suite of models...it is still difficult to pinpoint where
convection may set up, but the consensus appears to be that
southern IL, southwest IN and parts of SEMO have the best chances
to see additional development this afternoon into the evening
hours.
Models have become a little more persistent on lingering
precipitation in the our eastern sections (southeast IL, southwest
IN and the northern Pennyrile of western KY) later tonight (after
midnight) and even into Friday...as lingering moisture interacts
with the departing upper low to produce some showers. This is in
line with previous thinking so just minor adjustments will be
needed to POPs over the next 24 hours.
The effects of this upper low will finally get out of the region
Friday night. Then we can focus on another nice spring weekend,
which promises to be dry and warm. Although it will be rather cool
to start out the day on Saturday, as Friday nights lows will be in
the upper 40s across the north with lower 50s in the south.
.LONG TERM...(Sunday through Thursday)
Issued at 210 PM CDT Thu Apr 21 2016
A weak upper level ridge will move east by Monday providing a
southwest flow regime as one upper level low over the Dakotas
dissipates and another develops over the southern Rockies. This
moist flow will provide ample opportunities for showers and
thunderstorms for most of next week across the area.
At the surface, a weak front will lie east to west over the CWA by
late Tuesday. This is expected to move north as a warm front on
Wednesday. After that the models diverge slightly with the GFS
pushing a front through the area on Thursday. The ECMWF and GEFS
prefer to hang the front up either over our cwa or just to the
north.
All this means is that an unsettled, wet week is expected.
SPC has a small portion of the northwest edge of our CWA outlooked
for next Thursday. This looks pretty good as jet dynamics will be
strongest in that area ahead of a surface low lifting out of the
southern plains. Surface or elevated instability is forecast to be
over the area from Tuesday on. Any severe looks to be more isolated
in nature for us.
The Ensemble SA Tables suggest the heaviest rains will be Wednesday
and Thursday. However, any thunderstorm could produce locally heavy
rain next week.
&&
.AVIATION...
Issued at 1052 PM CDT Thu Apr 21 2016
Showers and isolated storms will eventually push east of the
terminals with KCGI now in the clear. Overnight, just some sct VFR
deck clouds 5-10k/ft. Light west winds. NW winds Friday may gust 15-
20 kts in the afternoon, with some sct-bkn mainly VFR clouds just
above 3k/ft, primarily KEVV and KOWB. Should clear out tomorrow
evening.
&&
.PAH Watches/Warnings/Advisories...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
SHORT TERM...CW
LONG TERM...PS
[top]
Area Forecast Discussion
National Weather Service Louisville KY
949 PM EDT THU APR 21 2016
...Forecast Update...
Issued at 949 PM EDT Thu Apr 21 2016
Watching line of storms crossing the Wabash River. The storms are
lined up along a corridor of relative instability. However, CIN is
starting to increase, and AMDAR soundings show a low level inversion
setting up, as well predicted by mesoscale models. The line went
right through the Evansville radar, which only showed velocities of
30-40 knots on the lowest scan as the line approached. ProbSvr has
dropped quite a bit over the last few volume scans, lightning has
decreased, and reflectivities have weakened slightly. These trends
all agree with the HRRR showing a weakening of the line as it moves
into southern Indiana. So, will go with the idea of the line
weakening, or at least not producing severe weather in the immediate
future. Will still keep an eye on it, of course.
.SHORT TERM (Now through Friday Night)...
Issued 303 PM EDT Thu Apr 21 2016
The Ohio Valley remains situated in the SW flow between upper ridge
axis to our east and vertically stacked low to our NW. A steady
plume of moisture will continue to ride SW to NE across our region
between these two features through the afternoon and evening. We`re
now beginning to see an eastward push to the activity as a wave
embedded in the southwest flow arrives. In addition to the eastward
push, seeing some convection fire. Expect that numerous showers and
scattered thunderstorms will be the rule for the remainder of the
afternoon, pushing east to a Lexington to Lake Cumberland line
through the evening. With freezing levels low, some small hail may
accompany brief heavy rainfall and a few cloud to ground ligthning
strikes.
Behind the main batch of precipitation, expect a brief lull in
activity as a dry slot works into the region. However as we approach
the evening into the overnight hours, another round of scattered to
numerous showers (and a few storms) will move into our west ahead of
the upper low. Given steeper lapse rates and low freezing levels,
some small hail will still be possible with these storms across our
west into the later evening hours. Expect that intensity and
coverage will diminish as we move through the overnight and lose
instability. Expect mainly scatteed showers exiting the east by dawn.
Lows tonight should be in the mid and upper 50s.
Upper low tracks across our northern CWA on Friday, which will yield
a cloudy and showery period driven by steep low and mid level lapse
rates. Enough instability should result for some thunder chances,
along with small hail/graupel given the low freezing levels. Will
carry scattered to numerous coverage mainly along and east of I-65
through the day. Highs will be noticeably cooler under
cloudy/showery upper low. Look for upper 60s to low 70s.
.LONG TERM (Saturday through Thursday)...
Issued at 303 PM EDT Wed Apr 20 2016
Saturday - Sunday Night...
Progressive upper ridging will build and transition through the
region over the weekend, bringing a return to dry and seasonably
warm temperatures. Saturday will be mostly sunny with a light NE
surface flow. With 850 temps expected to be around 7 to 8 C, expect
high temps in the low to mid 70s. Would be inclined to go a bit
higher, but will knock off a couple degrees given the surface wind
orientation and its generally cooler impact. Temperatures Saturday
evening, will be falling through the 60s.
A dry and cool Saturday night will see temps mostly in the upper 40s
and low 50s, although a few of our eastern spots may see mid 40s.
By Sunday, upper ridge axis will be directly overhead with high
temps recovering to up around 80. Will be inclined to go a degree or
two above MEX guidance for this day given the swing to southerly
flow and slightly deeper mixing. Sunday night will be continued
dry with slightly milder low temps in the upper 50s to around 60.
Monday - Monday Night...
Upper flow begins to flatten out to a more zonal look by the start
of the new work week in response to a passing northern stream wave.
This will allow a trailing cold front to sink southward toward the
Ohio River, becoming parallel to the upper flow as it does. At this
point, models suggest we could see some activity across our far
north by Monday afternoon/evening, however with dry air in place,
expect that things may be delayed a bit, much like we just saw with
today`s system. Models disagree on exact placement, but will tend to
lean toward the slower/drier outcome for now. Expect temps in the
low 80s on the south side of the frontal boundary. Monday night will
bring lows around 60 with a small chance of showers or t-storms
dependent on the setup mentioned above.
Tuesday - Thursday...
The mid week period looks to be more active as the frontal boundary
should be in the vicinity of the region. Do expect that areas along
the boundary would become unstable on the periphery of upper ridging
and with low level moisture pooling on the boundary. Meanwhile,
progressive upper flow would allow for some disturbances to pass
through and ultimately contribute to some convective organization.
For now, will continue with the fcst of temps in the mid and upper
70s and chances for scattered showers and t-storms during this time.
&&
.AVIATION (00Z TAF Update)...
Updated at 657 PM EDT Thu Apr 21 2016
An initial band of light to moderate rain will continue at LEX for
the first couple of hours, with a dry slot moving across all
terminals from west to east this evening. A band of showers is then
expected to move through the region during the overnight/pre-dawn
hours.
The upper low causing the rain will move up the Ohio River tomorrow
and spark scattered showers and perhaps a few thunderstorms with
daytime heating. The best chances will be at SDF and LEX, closer to
the low.
Ceilings are a huge challenge. Low ceilings have been reluctant to
materialize here and upstream. While MVFR ceilings are a possibility
tonight and tomorrow, for now will go a bit more optimistic which is
a tack that has been working out well recently. So, will keep things
VFR for now but don`t see surprised to see AMDs with lower ceiling
heights if they do begin to form here or upstream.
&&
.LMK Watches/Warnings/Advisories...
KY...NONE.
IN...NONE.
&&
$$
Update.........13
Short Term.....BJS
Long Term......BJS
Aviation.......13
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
743 PM CDT THU APR 21 2016
.AVIATION...
FOR THE 22/00Z TAFS...WEAK COLD FRONT CONTINUES TO SLOWLY WORK EWD
ACROSS THE REGION THIS EVENING AND GENERALLY EXTENDS ALONG A LINE
FROM ELD TO SHV TO LFK. SPOTTY SHWRS CONTINUE TO DEVELOP INVOF OF
THE FRONT SO HAVE INCLUDED VCSH IN MOST OF THE AREA TAFS THROUGH
EARLY EVENING...WITH TEMPO -SHRA AT MLU. ALL SITES ARE VFR WITH
CU GRADUALLY DIMINISHING OVERNIGHT AFTER FROPA OCCURS. SOME PATCHY
FOG IS POSSIBLE TOWARD DAYBREAK WITH VERY LIGHT W/NW WINDS AND A
VERY LIMITED AIR MASS MODIFICATION BEHIND THE FRONT. NW WINDS WILL
INCREASE TO BETWEEN 5-10 KTS AFTER 22/15Z WITH SOME CU POSSIBLE IN
THE AFTERNOON ON FRIDAY. /19/
&&
.PREV DISCUSSION... /ISSUED 610 PM CDT THU APR 21 2016/
UPDATE...
SENT A QUICK UPDATE TO ADD 20% POPS TO SW AR AND NE TX AHEAD OF A
COLD FRONT THAT CONTINUES TO PUSH CLOSER TOWARDS THE I-30
CORRIDOR. HRRR SUGGESTS THAT THIS ACTIVITY WILL CONTINUE TO STAY
WIDELY SCATTERED IN NATURE AS THE FRONT PUSHES FURTHER TO THE
SOUTH AND EAST THIS EVENING.
NO OTHER CHANGES ATTM...13.
PREV DISCUSSION... /ISSUED 244 PM CDT THU APR 21 2016/
DISCUSSION...
WV IMAGERY SHOWS SERIES OF DISTURBANCES ASSOCIATED WITH THE UPPER
LOW CENTERED OVER THE UPPER MS RIVER VALLEY THIS AFTN. THE FIRST
IS MAKING ITS WAY SEWD ACROSS E TX...WHICH IS RESPONSIBLE FOR THE
ONGOING THUNDERSTORMS ALONG THE TX GULF COAST AND INTO SW LA. AN
ASSOCIATED SHALLOW SFC BOUNDARY IS DRAPED ACROSS OUR E TX
COUNTIES...BUT IS HELD UP BY THE OUACHITA MTNS OF SE OK. LINE OF
CONVECTION WILL CONTINUE TO MOVE ESEWD THIS AFTERNOON...FINALLY
MOVING OUT OF OUR REGION BY SUNSET. THE SECOND UPPER DISTURBANCE...
WHICH IS CURRENTLY OVER KS...WILL CONTINUE DIVING DOWN THE PLAINS
TONIGHT AND WILL REINFORCE THE COLD FRONT AND FORCE IT THROUGH OUR
REGION.
CLEARING SKIES TONIGHT WILL LIKELY ALLOW FOR SOME PATCHY FOG TO
DEVELOP. AREAS OF E TX/NW LA/SW AR WILL BE MOST PRONE TO THIS
POSSIBILITY WHERE RECENT RAINFALL HAS LEFT SOILS SATURATED.
MUCH DRIER CONDITIONS ARE EXPECTED IN THE WAKE OF THE FRONT FOR
FRIDAY AND SATURDAY...AS THE UPPER LOW FINALLY PUSHES EWD AND
RIDGING TAKES ITS PLACE OVER THE SRN PLAINS. TEMPS WILL LIKELY
REACH UP INTO THE LOW TO MID 80S FOR FRIDAY AND SATURDAY AS A
RESULT OF THE UPPER RIDGE OVHD...DRY AIR AT THE SFC...AND ABUNDANT
SUNSHINE.
THE DRY WEATHER WILL BE SHORT-LIVED HOWEVER...AS SW FLOW ALOFT
RETURNS BY LATE SUNDAY. WE WILL REMAIN IN A WARM AND UNSETTLED
PATTERN FOR THE REMAINDER OF THE FCST PD...AS A SERIES OF UPPER
LOWS MOVE ACROSS THE PLAINS IN SW FLOW AND BRING SEVERAL COLD
FRONTS INTO THE REGION. SHWRS/TSTMS WILL REMAIN IN THE FCST IN
SOME CAPACITY FOR MUCH OF NEXT WORK WEEK AS A RESULT. /12/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 58 80 56 82 / 20 0 0 0
MLU 59 79 56 81 / 30 0 0 0
DEQ 50 79 52 80 / 20 0 0 0
TXK 55 78 54 81 / 20 0 0 0
ELD 56 78 54 81 / 20 0 0 0
TYR 56 79 55 81 / 20 0 0 0
GGG 56 80 55 82 / 20 0 0 0
LFK 60 81 56 83 / 20 10 0 0
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
19/13
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
610 PM CDT THU APR 21 2016
.UPDATE...
SENT A QUICK UPDATE TO ADD 20% POPS TO SW AR AND NE TX AHEAD OF A
COLD FRONT THAT CONTINUES TO PUSH CLOSER TOWARDS THE I-30
CORRIDOR. HRRR SUGGESTS THAT THIS ACTIVITY WILL CONTINUE TO STAY
WIDELY SCATTERED IN NATURE AS THE FRONT PUSHES FURTHER TO THE
SOUTH AND EAST THIS EVENING.
NO OTHER CHANGES ATTM...13.
&&
.PREV DISCUSSION... /ISSUED 244 PM CDT THU APR 21 2016/
DISCUSSION...
WV IMAGERY SHOWS SERIES OF DISTURBANCES ASSOCIATED WITH THE UPPER
LOW CENTERED OVER THE UPPER MS RIVER VALLEY THIS AFTN. THE FIRST
IS MAKING ITS WAY SEWD ACROSS E TX...WHICH IS RESPONSIBLE FOR THE
ONGOING THUNDERSTORMS ALONG THE TX GULF COAST AND INTO SW LA. AN
ASSOCIATED SHALLOW SFC BOUNDARY IS DRAPED ACROSS OUR E TX
COUNTIES...BUT IS HELD UP BY THE OUACHITA MTNS OF SE OK. LINE OF
CONVECTION WILL CONTINUE TO MOVE ESEWD THIS AFTERNOON...FINALLY
MOVING OUT OF OUR REGION BY SUNSET. THE SECOND UPPER DISTURBANCE...
WHICH IS CURRENTLY OVER KS...WILL CONTINUE DIVING DOWN THE PLAINS
TONIGHT AND WILL REINFORCE THE COLD FRONT AND FORCE IT THROUGH OUR
REGION.
CLEARING SKIES TONIGHT WILL LIKELY ALLOW FOR SOME PATCHY FOG TO
DEVELOP. AREAS OF E TX/NW LA/SW AR WILL BE MOST PRONE TO THIS
POSSIBILITY WHERE RECENT RAINFALL HAS LEFT SOILS SATURATED.
MUCH DRIER CONDITIONS ARE EXPECTED IN THE WAKE OF THE FRONT FOR
FRIDAY AND SATURDAY...AS THE UPPER LOW FINALLY PUSHES EWD AND
RIDGING TAKES ITS PLACE OVER THE SRN PLAINS. TEMPS WILL LIKELY
REACH UP INTO THE LOW TO MID 80S FOR FRIDAY AND SATURDAY AS A
RESULT OF THE UPPER RIDGE OVHD...DRY AIR AT THE SFC...AND ABUNDANT
SUNSHINE.
THE DRY WEATHER WILL BE SHORT-LIVED HOWEVER...AS SW FLOW ALOFT
RETURNS BY LATE SUNDAY. WE WILL REMAIN IN A WARM AND UNSETTLED
PATTERN FOR THE REMAINDER OF THE FCST PD...AS A SERIES OF UPPER
LOWS MOVE ACROSS THE PLAINS IN SW FLOW AND BRING SEVERAL COLD
FRONTS INTO THE REGION. SHWRS/TSTMS WILL REMAIN IN THE FCST IN
SOME CAPACITY FOR MUCH OF NEXT WORK WEEK AS A RESULT. /12/
PREV DISCUSSION... /ISSUED 1245 PM CDT THU APR 21 2016/
AVIATION...
CONVECTION HAS SHIFTED SOUTH OF MOST OF THE AREA AND AREAL
TERMINALS....INCLUDING MOST RECENTLY...KLFK. HOWEVER...A WEAK
COLD FRONT WILL SLOWLY MOVE ACROSS THE REGION THIS AFTN...AND
AIRMASS STILL QUITE UNSTABLE WITH MARGINAL MOISTURE BUT STEEP
LAPSE RATES. THEREFORE...ISOLD TO POSSIBLY SCT CONVECTION MAY
REDEVELOP WITH ANY DAYTIME HEATING THAT POKES THRU MOSTLY MVFR
CLOUD DECKS ACROSS MUCH OF LA...INCLUDING KELD TERMINAL...AND
POSSIBLY AT KLFK. WINDS TO REMAIN MOSTLY LGT AND VRBL THIS
AFTN...AND ALSO FOLLOWING FROPA. WITH SKIES BECMG SKC OR SCT CLOUD
DECKS...PATCHY FOG EXPECTED LATER TONIGHT...ESPECIALLY AT
TERMINALS WHERE HEAVY RAIN OCCURRED. WINDS BECMG NW 5 TO 10 KTS
BEFORE 22/18Z./VII/.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 58 80 56 82 / 20 0 0 0
MLU 59 79 56 81 / 30 0 0 0
DEQ 50 79 52 80 / 20 0 0 0
TXK 55 78 54 81 / 20 0 0 0
ELD 56 78 54 81 / 20 0 0 0
TYR 56 79 55 81 / 20 0 0 0
GGG 56 80 55 82 / 20 0 0 0
LFK 60 81 56 83 / 20 10 0 0
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
VII/12/13
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1215 PM EDT WED APR 20 2016
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE REGION TODAY THROUGH THURSDAY.
LOW PRESSURE WILL CROSS THE AREA FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1215 PM UPDATE...WINDS AND SKY NEEDED ADJUSTMENTS PER THE LATEST
SATELLITE AND OBS. MORE CLOUDS ACROSS THE NORTHERN 1/2 OF THE CWA
W/CAA TODAY. NW WIND/DOWNSLOPE AIDING IN KEEPING LESS CLOUDS FOR
THE SOUTHERN 1/2 OF THE CWA. SPEAKING OF THE NW WINDS, INCREASED
THEM A BIT MORE INCLUDING GUSTS TO 25 MPH. LATEST HRRR 3KM MODEL
SHOWED WINDS DROPPING OFF LATER THIS AFTERNOON AS HIGH PRES PUSHES
E.
PREVIOUS DISCUSSION...
QUIET WEATHER IS EXPECTED ACROSS THE
REGIONTODAY AS HIGH PRESSURE SETTLES OVER THE NORTHEASTERN CONUS.
CLOUDS WILL GRADUALLY DISSIPATE THROUGH THE DAY WITH EVERYONE SEEING
SUNSHINE BY LATE AFTERNOON. HIGHS WILL BE SIMILAR TO YESTERDAY.
DECENT MIXING TO 6-7 KFT WILL ALLOW WINDS TO BE A LITTLE BREEZY THIS
AFTERNOON, AS WELL AS LOWERING DEWPOINTS INTO THE UPPER TEENS AND
LOWER 20S. THE WINDS AND LOW RELATIVE HUMIDITY RAISE SOME FIRE
WEATHER CONCERNS, BUT WON`T REACH RED FLAG LEVELS. A SPECIAL WEATHER
STATEMENT MAY BE NEED TO BE ISSUED LATER TODAY.
FOR TONIGHT...DRY WEATHER CONTINUES. MODELS INDICATE THERE`LL BE
SOME MOISTURE STREAMING IN AROUND THE TOP OF THE UPPER RIDGE
OVERNIGHT, SO MID-LEVEL CLOUDS WILL INCREASE FOR A BIT TONIGHT. LOWS
WILL BOTTOM OUT AROUND 30 IN THE NORTH AND IN THE LOWER TO MID 30S
SOUTH.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
THU LOOKS TO BE WARM AND DRY AS DOWNSLOPING WNW SFC WINDS BRINGS A
A SIG WARM-UP IN THE 925-850MB LAYER...ALLOWING ALL NON-HIGH TRRN
AND NON-IMMEDIATE COASTAL AREAS OF THE FA TO REACH WELL INTO THE
60S AND EVEN ARND 70 DEGREES OVR CNTRL AND WRN INTERIOR DOWNEAST
LCTNS. SKIES WILL REMAIN FAIR THU EVE...THEN BEGIN TO INCREASE
CLDNSS FROM THE W LATE TNGT AFT THE 500MB RIDGE CROSSES THE FA AND
WEAK SFC LOW PRES AND S/WV ENERGY FROM BOTH THE MIDWEST AND S
CNTRL CAN BEGIN TO APCH THE FA.
TEMPS WILL WARM SOMEWHAT WITH FILTERED MORN SUNSHINE...THEN
STABILIZE IN THE AFTN BY 5 TO 10 DEG COOLER THAN THU`S HI TEMPS
WITH THE ARRIVAL OF SHWRS INTO THE FA. SIX HRLY QPFS LOOK TO BE
LGT...WITH PERHAPS A LITTLE MORE IN THE W CNTRL PTNS OF THE FA
INCLUDING UP TO BAXTER ST PARK IN THE FRI 18-24Z TM FRAME...
JUSTIFYING LOW END CATEGORICAL MAX POPS OVR THIS AREA BY LATE
FRI AFTN...WITH LESSER POPS FURTHER N AND E.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MOST LONGER RANGE MODELS CONT SHWRS OVR THE FA INTO THE EVE...
THEN MOVE SHWRS E OF THE REGION LATE FRI NGT AND ERLY SAT MORN AS
A COLD FRONT CROSSES THE FA. FCST QPF AMTS IN THE SAT 00-06Z ARE
ALSO RELATIVELY LIGHT FOR MOST MODELS...XCPT THE 00Z DTMNSTC GFS
WHICH INDICATES 0.35 TO 0.85 INCHES FOR THIS PD. NOT SURE WHATS
DRIVING THIS AMOUNT OF QPF IN THE DTMNSTC GFS MODEL IN THE 00-06Z
TM FRAME...BUT IN ADDITION TO NOT BEING SUPPORTED BY THE OTHER
DTMNSTC 00Z MODELS...IT IS NOT BEING BACKED BY THE 00Z GFS ENSM
QPF WHICH ONLY SHOWS 0.10 TO 0.20 INCHES WITH ONLY A COUPLE OF
INDIVIDUAL ENS MEMBERS SUGGESTING QPF IN THE 0.25 TO 0.50 INCH
RANGE. BASED ON THIS DISCREPANCY...WE DID RAISE POPS INTO THE
LIKELY CATEGORY FRI EVE INTO OVRNGT FOR ALL XCPT THE FAR NW PTN
OF THE FA THINKING THAT A LITTLE MORE ORGANIZED RNFL IS POSSIBLE
WHERE WE INDICATE LIKELY POPS...BUT NOT CONVINCED OF MDT TO HVY
RNFL ATTM WITH PLENTY OF TM STILL AVAILABLE FOR BETTER MODEL
CONSENSUS FROM THE GFS PRIOR TO THE EVENT ENTERING THE NEAR TERM.
OTHERWISE...SAT INTO SAT NGT LOOKS TO BE FAIR...BREEZY... DRY AND
COOLER BEHIND THE FIRST COLD FRONT. A SECONDARY COLD FRONT WILL
BRING CLOUDINESS TO THE REGION BY SUN AFTN AND ISOLD TO SCT RN/SN
SHOWERS WITH VERY LGT QPF TO THE REGION SUN EVE. COLDER AIR AND
ACCOMPANIED BY BRISK AND MSLY DRY CONDITIONS WILL FOLLOW FOR MON
INTO TUE AS A DEEP MID LVL VORTEX SLIDES INTO THE NRN CAN
MARITIMES WITH SIG BELOW NORMAL HIGH TEMPS AND SLIGHTLY BELOW
AVG OVRNGT LOWS.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: VFR WILL PREVAIL TODAY AND TONIGHT WITH NO PRECIPITATION
EXPECTED.
SHORT TERM: VFR CONDITIONS XPCTD ACROSS THE TAF SITES THU INTO FRI
MORN...WITH CLGS AND VSBYS POTENTIALLY LOWERING TO MVFR IN SCT TO
NUMEROUS SHWRS ADVCG EWRD FROM QB FRI AFTN INTO THE OVRNGT.
CONDITIONS SHOULD IMPROVE BACK TO VFR ON SAT BEHIND THE COLD FRONT
AND THEN CONT SO THRU SUN.
&&
.MARINE...
NEAR TERM: A SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 11 AM
THIS MORNING. WINDS WILL INCREASE THROUGH THE EARLY MORNING HOURS
IN RESPONSE A WEAK FRONTAL PASSAGE. GUSTS AROUND 25 KT AND WAVES
OF 2 TO 4 FT ARE EXPECTED. CONDITIONS WILL IMPROVE DURING THE
AFTERNOON AS HIGH PRESSURE BUILDS OVER THE WATERS.
SHORT TO LONG TERM: NO WELL DEFINED PERIODS OF SCA OR GREATER
CONDITIONS ARE XPCTD ATTM THRU THESE PTNS OF THE COASTAL WATERS
FCST. KEPT CLOSE TO WW3 WV GUIDANCE FOR FCST WV HTS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1114 PM EDT THU APR 21 2016
.SYNOPSIS...
HIGH PRESSURE REMAINS OVER THE WESTERN ATLANTIC TONIGHT. A COLD
FRONT WILL APPROACH FROM THE WEST FRIDAY...PUSHING OFF THE COAST
EARLY SATURDAY MORNING. AN UPPER LEVEL DISTURBANCE DROPS OVER THE
REGION SATURDAY. HIGH PRESSURE RETURNS FOR SATURDAY NIGHT INTO
MONDAY. THE NEXT COLD FRONT PUSHES ACROSS THE REGION TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
FORECAST UPDATED BASED ON LATEST RADAR TRENDS AND HIRES MODEL
GUIDANCE...MAIN CHANGES WERE TO DROP ANY CHC OF PCPN THIS EVENG
AND DELAY POPS A BIT FRI MORNG.
PREVIOUS DISCUSSION...
LATEST REGIONAL RADAR MOSAIC DEPICTS ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS EXTENDING FROM SE NC INTO CENTRAL NC
THIS AFTERNOON. BASED ON LATEST SFC OBS...THE WARM FRONT HAS
LIFTED INTO THE LOCAL AREA...WITH BETTER DESTABILIZATION SOUTH OF
THE LOCAL AREA. EXPECT THE BETTER INSTABILITY TO REMAIN SOUTH OF
THE REGION...BUT HI-RES GUIDANCE CONTINUES TO INDICATE THE
POTENTIAL FOR ISOLATED TO WIDELY SCATTERED SHOWERS LIFTING INTO
SRN VA AND NE NC THRU LATE THIS AFTERNOON. NAM12 300K SURFACES
BACK UP THIS SCENARIO...INDICATING LOW LEVEL LIFT EVEN UNDER THE
UPPER LEVEL RIDGE LOCATED OVER THE ERN CONUS. RAP SOUNDINGS
INDICATE MODEST CAPE EXTENDING INTO THE MIXED PHASE LAYER...SO
WILL MENTION SLIGHT CHANCE FOR THUNDER. ANY SHOWERS THAT DO
DEVELOP WILL DISSIPATE EARLY EVENING WITH THE LOSS OF DAYTIME
HEATING.
TEMPS HAVE WARMED INTO THE MID/UPPER 70S...WITH A FEW LOCALES
HITTING 80 ACROSS THE PIEDMONT INTO CENTRAL VA. SOUTH WINDS AROUND
10 MPH TONIGHT ALONG WITH A PARTLY CLOUDY SKY WILL RESULT IN MILD
OVERNIGHT TEMPS. LOWS GENERALLY IN THE LOW 60S (~+1 STD DEV OR 10-12
DEGS ABOVE NORMAL).
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
GENERAL MODEL TRENDS CONTINUE TO SLOW THE UPPER SYSTEM SLIGHTLY AND
DIG IT FARTHER SOUTH AND WEST THROUGH FRIDAY NIGHT. CURRENT NATIONAL
RADAR TRENDS OVER THE OH VALLEY...DEPICT RATHER UNORGANIZED
CONVECTION ASSOCIATED WITH THE UPPER LOW. THE UPPER LOW PUSHES INTO
THE TN VALLEY AS A STRONG UPPER LOW DEEPENS OVER ERN CANADA. THE
FRONT REACHES THE ERN VA PIEDMONT LATE FRIDAY INTO EARLY FRI
EVENING. LEAD SHORTWAVE ENERGY ROUNDS THE BASE OF THE UPPER
TROUGH...LIFTING INTO THE REGION FRI AFTERNOON AHEAD OF THE MAIN
TROUGH ENERGY. RETURN FLOW ADVECTS DEEPER MOISTURE INTO THE
REGION...WITH H85 FLOW COMING IN FROM THE GULF STREAM. POPS RAMP UP
OVER THE PIEDMONT MID TO LATE MORNING...AND THEN POINTS EWD THROUGH
EARLY AFTERNOON. THE FAVORED AREAS FOR SHOWERS CONTINUE TO BE ALONG
AND SOUTH OF A LINE FROM FARMVILLE TO RICHMOND AND TO THE NRN
NECK/MD ERN SHORE FRI AFTERNOON AND FRIDAY EVENING. HAVE MAINTAINED
LIKELY POPS FOR THAT AREA. HAVE TRIMMED BACK POPS NORTH AND WEST OF
THIS LINE AS MODELS INDICATE SHOWER COVERAGE ASSOCIATED WITH THE
MAIN SHORTWAVE WILL BE LIMITED IN THAT REGION. THUNDERSTORM
POTENTIAL REMAINS MARGINAL DUE TO CONSIDERABLE CLOUD COVER AND
MARGINAL INSTABILITY. GIVEN THE DYNAMICS...THETA-E ADVECTION AND THE
TIME OF YEAR...WILL KEEP CHANCE MENTION OF THUNDER. SHEAR REMAINS
MODEST (AOB 30 KT)...SO EXPECT ONLY EMBEDDED THUNDER. PWATS CLIMB TO
1.25 TO 1.5 INCHES...WHICH MAY RESULT IN PERIODS OF MODERATE TO
LOCALLY HEAVY RAINFALL. HOWEVER...QPF AMOUNTS THRU FRIDAY EVENING
WILL GENERALLY RANGE FROM LESS THAN ONE QUARTER OF AN INCH ACROSS
THE NORTH UP TO ONE HALF INCH ACROSS THE SOUTH. AREA REMAINS IN WARM
SECTOR WITH RETURN FLOW PUSHING TEMPS BACK INTO THE MID/UPPER
70S...EVEN WITH CONSIDERABLE CLOUD COVER. SHORTWAVE DROPS OVER THE
CENTRAL APPALACHIANS INTO THE LOCAL AREA THRU FRI NIGHT AS THE FRONT
PUSHES OFFSHORE. WILL KEEP SOLID CHANCE POPS ALONG THE COAST THRU
THE OVERNIGHT PERIOD.
AFOREMENTIONED MODEL TRENDS MEAN LINGERING MID LEVEL MOISTURE TO
GO ALONG WITH THE STRONG DYNAMICS PROVIDED BY THE UPPER LOW DROPPING
OVER THE REGION SAT. WILL HOLD ONTO SOLID CHANCE POPS THROUGH LATE
MORNING INLAND FOR SCATTERED SHOWERS...AND ALONG THE COAST THRU SAT
AFTERNOON. CLOUDY CONDITIONS BECOME PARTLY CLOUDY INLAND SAT
AFTERNOON...BUT REMAIN MOSTLY CLOUDY ALONG THE COAST. TRENDED TOWARD
THE COOLER SIDE OF THE MOS GUIDANCE DUE TO CLOUD COVER AND MODEST
CAA...BUT TEMPS REMAIN SEASONABLE IN THE UPPER 60S/LOW 70S.
NORTH WINDS GENERALLY 10 TO 15 MPH WITH GUSTS OF 20 TO 25 MPH. TROUGH
AXIS PUSHES OFFSHORE SAT NIGHT WITH DRY CONDITIONS FORECAST ACROSS
THE AREA. LOWS IN THE MID/UPPER 40S INLAND TO LOW 50S NEAR THE COAST
UNDER A CLEAR SKY. HIGH PRESSURE BUILDS ACROSS NEW ENGLAND SAT
NIGHT...PARKING OFF THE NORTHEAST COAST SUNDAY. THE RESULT WILL BE
ONGOING DRY CONDITIONS. CAA WANES SUN...BUT LIGHT ONSHORE FLOW WILL
KEEP TEMPS IN CHECK. THICKNESSES YIELD TEMPS IN THE LOW/MID 70S
INLAND AND MID/UPPER 60S ALONG THE COAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE SLIDES FARTHER OFFSHORE SUNDAY NIGHT AND MONDAY...AND
SETTLES OFF THE SOUTHEAST COAST BY TUESDAY. MEANWHILE...A SHORTWAVE
TROUGH AND AN ASSOCIATED COLD FRONT APPROACH FROM THE NW BY TUESDAY
AFTN. MONDAY AND TUESDAY ARE TRENDING TOWARD BEING VERY WARM DAYS
WITH DEEP LAYER WSW FLOW ASSOCIATED WITH A BREAKING DOWN UPPER RIDGE
OVER THE E-CENTRAL/SERN CONUS. MODEL CONSENSUS GENERALLY SUPPORTS
850MB TEMPERATURES OF 12-15C...WHICH WITH FULL MIXING AND
DOWNSLOPING SHOULD EASILY PUSH HIGHS TO 80-85F W OF THE BAY...WITH
UPPER 70S FOR THE ERN SHORE. LOWS SUNDAY NIGHT SHOULD BE IN THE
LOW/MID 50S...WITH 55-60F MONDAY NIGHT. SKY COVER SHOULD GENERALLY
BE MOSTLY CLEAR/SUNNY SUNDAY NIGHT...MONDAY INTO MONDAY NIGHT...AND
BECOME PARTLY SUNNY TUESDAY. THE TROUGH AND COLD FRONT SWING THROUGH
THE AREA TUESDAY AFTN INTO TUESDAY NIGHT. THE MAIN FORCING
ASSOCIATED WITH THE MID/UPPER SHORTWAVE TROUGH GENERALLY PASSES N OF
THE LOCAL AREA...AND DEEP LAYER RH DIMINISHES AS THE FEATURE PASSES
OVER THE LOCAL AREA SO FORECAST POPS ARE ONLY 20%...WITH A NARROW
STRIP OF 30% ACROSS THE FAR N. HIGH PRESSURE BUILDS IN FROM THE N
WEDNESDAY...AND SLIDES OFFSHORE LATER IN THE WEEK. HIGHS WEDNESDAY
SHOULD DROP BACK TO THE MID/UPPER 60S NE...TO THE MID/UPPER 70S
FARTHER INLAND...AND THEN TREND UPWARD INTO THURSDAY AS THE HIGH
SLIDES OFFSHORE. LOWS SHOULD GENERALLY BE IN THE 50S.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
SURFACE HIGH PRESSURE REMAINS OFF THE SE COAST AS COLD FRONT AND
ASSOCIATED SURFACE TROUGH SLOWLY MOVE THROUGH THE MIDWEST.
SOUTHERLY FLOW CONTINUES TO INCREASE MOISTURE INTO THE MID-
ATLANTIC TOMORROW. EXPECT SW WIND GUST ~20KT FRI AFTN WITH THE
POTENTIAL FOR MVFR CIGS. AHEAD OF THE FRONT...DAYTIME HEATING AND
INCREASING MOISTURE ALONG WITH SHORTWAVE ENERGY MOVING OVER THE
REGION WILL INCREASE THE POTENTIAL FOR AFTN SHOWERS AND TSTMS.
GUSTY WINDS AND HEAVY RAIN WILL BE POSSIBLE IN ANY STORM.
FRONT PASSES OF THE COAST LATE FRI/EARLY SAT. TRAILING CLOSED UPPER
LOW WILL CAUSE LAPSE RATES TO INCREASE...CONTINUING THE
POSSIBILITY FOR MVFR CIGS AND STORM DEVELOPMENT INTO SAT. DRIER
AIR AND VFR CONDITIONS RETURN LATE SAT NIGHT.
&&
.MARINE...
WENT AHEAD AND ISSUED A MINIMAL SCA FOR THE CHES BAY THROUGH 4 AM
BASED ON THE AMOUNT OF 20 KT GUSTS REPORTED OVER THE PAST FEW HOURS.
PVS DSCN:
HIGH PRESSURE IS SITUATED WELL OFFSHORE THIS AFTN...WITH
LOW PRESSURE WELL TO THE W OVER THE MID-MISSISSIPPI VALLEY. THE HIGH
WILL CONTINUE TO SLIDE FARTHER OFFSHORE TONIGHT AS LOW PRESSURE
LIFTS NE OVER THE GREAT LAKES. A SW WIND SHOULD AVERAGE 10-15KT
THROUGH THIS EVENING...AND THEN INCREASE TO 15KT BAY/15-20KT OCEAN
LATER THIS EVENING THROUGH FRIDAY MORNING...BEFORE DIMINISHING
FRIDAY AFTN/EVENING AS THE PRESSURE GRADIENT SLACKENS AS A WEAK COLD
FRONT GRADUALLY DROPS INTO THE REGION. THE COLD FRONT PUSHES THROUGH
THE AREA EARLY SATURDAY MORNING...WITH A SUBSEQUENT NORTHERLY SURGE
MIDDAY SATURDAY...WITH A SECONDARY SURGE SATURDAY EVENING. MARGINAL
SCA CONDITIONS ARE POSSIBLE OVER THE BAY (15-20KT N WIND). HIGH
PRESSURE BUILDS OVER THE AREA SATURDAY NIGHT AND SUNDAY...SLIDES
OFFSHORE MONDAY...AND SETTLES OFF THE SOUTHEAST COAST TUESDAY. SEAS
GENERALLY AVERAGE 2-4FT...WITH 2-3FT WAVES IN THE BAY.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT FRIDAY FOR ANZ630>632-634.
&&
$$
SYNOPSIS...SAM/TMG
NEAR TERM...MAS/SAM
SHORT TERM...SAM
LONG TERM...AJZ
AVIATION...ALB/DAP
MARINE...AJZ/MPR
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1017 PM EDT THU APR 21 2016
.SYNOPSIS...
LOW PRESSURE WILL BRING INCREASING SHOWER CHANCES THROUGH
FRIDAY...FOLLOWED BY DRY AND SEASONAL WEATHER THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
LATEST RADAR IMAGERY IS A LITTLE DECEIVING...AS PRECIPITATION IS
STILL NOT MAKING IT TO THE GROUND UNDER WEAKER RETURNS. THE 00Z
SOUNDING STILL INDICATED A FAIR AMOUNT OF DRY AIR IN THE LOWER
LEVELS AND LATEST RAP SOUNDINGS INDICATE IT SHOULD TAKE THE
MAJORITY OF THE NIGHT TO BECOME SATURATED IN LOWER LEVELS...SO
WHILE PRECIPITATION ASSOCIATED WITH THE LEADING SHORTWAVE WAS
CARRIED THROUGH THE NIGHT ACROSS THE REGION...IT WILL LARGELY BE
VERY LIGHT. OVERNIGHT LOW TEMPERATURES WILL RANGE 10-15 DEG ABOVE
NORMAL WITH CONTINUED WARM AIR ADVECTION AND CLOUD COVERAGE
LIMITING ANY RADIATIONAL COOLING.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
ANY PRECIPITATION WILL BE WIDELY SCATTERED FRIDAY MORNING IN THE
WAKE OF THE INITIAL SHORTWAVE UNTIL THE UPPER LOW CURRENTLY OVER
INDIANA AND SLOWLY MOVING EAST NEARS THE REGION DURING THE
AFTERNOON AND INCREASES INSTABILITY. HAVE INCLUDED MENTION OF
THUNDERSTORMS MID AFTERNOON THROUGH EARLY EVENING...WITH SOUTHERN
LOCATIONS CLOSEST TO THE UPPER LOW CENTER PROGGED TO CLIP THE
SOUTHERN FRINGE OF THE CWA HAVING THE BEST CHANCES ALONG THE FRONT
AND JUST AHEAD OF THE UPPER LOW. PRECIPITATION CHANCES WILL
PERSIST UNTIL SATURDAY MORNING WHEN RIDGING BUILDS BACK IN FROM
THE WEST.
BUILDING RIDGING IS THEN EXPECTED TO BRING DRY WEATHER THROUGH
THE REST OF THE WEEKEND. TEMPERATURES ARE EXPECTED TO AVERAGE
NEAR OR SEVERAL DEGREES ABOVE SEASONAL LVLS USING GFS MOS AND A
CONSENSUS BLEND GUIDANCE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A COLD FRONT WILL SLOWLY CROSS THE REGION LATER MONDAY THROUGH
TUESDAY BRINGING SHOWERS. BUBBLE OF HIGH PRESSURE WITH DRY BUT
STILL MILD CONDITIONS WEDNESDAY. LOW PRESSURE ADVANCING FROM THE
NATIONS MID SECTION WILL RETURN SHOWERS FOR LATE WEEK. A SLIGHTLY
MODIFIED SUPERBLEND WAS USED FOR THE EXTENDED FORECAST.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
WIND HAS BEEN QUITE VARIABLE IN DIRECTION DURING THE LATE
AFTERNOON AT SEVERAL SITES AS SCATTERED SHOWERS MOVE ACROSS THE
REGION. THINK THIS WILL CONTINUE TO BE THE CASE THROUGH THE
EVENING HOURS...WITH A MORE UNIFORM WIND OUT OF THE SOUTH
DEVELOPING AFTER MIDNIGHT.
THERE WILL BE A BRIEF PERIOD WHERE AN ISOLATED THUNDERSTORM IS
POSSIBLE TONIGHT...BUT THE STORM THAT MOVED TO THE NORTH OF
PITTSBURGH APPEARS TO HAVE WEAKENED ENOUGH THAT THUNDER SHOULD NOT
BE A CONCERN AT DUJ OR OTHER SITES. ALTHOUGH CONDITIONS WILL
INITIALLY BE VFR AT THE START OF THE TAF PERIOD...SCATTERED
SHOWERS WILL BECOME MORE WIDESPREAD AFTER MIDNIGHT AS DEEPER
MOISTURE ENTERS THE REGION AND YIELDS MVFR RESTRICTIONS. AFTER A
BIT OF A LULL IN SHOWERS FRIDAY MORNING...SHOWERS WILL INCREASE IN
COVERAGE AGAIN FRIDAY AFTERNOON...WITH CEILINGS LIKELY TO RISE
BACK TO VFR CATEGORY.
.OUTLOOK /FRIDAY NIGHT THROUGH TUESDAY/...
RESTRICTIONS ARE EXPECTED FRIDAY NIGHT WITH IFR CEILINGS POSSIBLE
AS LOW PRESSURE MOVES EAST. THE NEXT CHANCE FOR WIDESPREAD
RESTRICTIONS WILL BE MONDAY NIGHT AND TUESDAY AS A COLD FRONT
APPROACHES.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
947 PM EDT THU APR 21 2016
.SYNOPSIS...
HIGH PRESSURE REMAINS OVER THE WESTERN ATLANTIC TONIGHT. A COLD
FRONT WILL APPROACH FROM THE WEST FRIDAY...PUSHING OFF THE COAST
EARLY SATURDAY MORNING. AN UPPER LEVEL DISTURBANCE DROPS OVER THE
REGION SATURDAY. HIGH PRESSURE RETURNS FOR SATURDAY NIGHT INTO
MONDAY. THE NEXT COLD FRONT PUSHES ACROSS THE REGION TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
FORECAST UPDATED BASED ON LATEST RADAR TRENDS AND HIRES MODEL
GUIDANCE...MAIN CHANGES WERE TO DROP ANY CHC OF PCPN THIS EVENG
AND DELAY POPS A BIT FRI MORNG.
PREVIOUS DISCUSSION...
LATEST REGIONAL RADAR MOSAIC DEPICTS ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS EXTENDING FROM SE NC INTO CENTRAL NC
THIS AFTERNOON. BASED ON LATEST SFC OBS...THE WARM FRONT HAS
LIFTED INTO THE LOCAL AREA...WITH BETTER DESTABILIZATION SOUTH OF
THE LOCAL AREA. EXPECT THE BETTER INSTABILITY TO REMAIN SOUTH OF
THE REGION...BUT HI-RES GUIDANCE CONTINUES TO INDICATE THE
POTENTIAL FOR ISOLATED TO WIDELY SCATTERED SHOWERS LIFTING INTO
SRN VA AND NE NC THRU LATE THIS AFTERNOON. NAM12 300K SURFACES
BACK UP THIS SCENARIO...INDICATING LOW LEVEL LIFT EVEN UNDER THE
UPPER LEVEL RIDGE LOCATED OVER THE ERN CONUS. RAP SOUNDINGS
INDICATE MODEST CAPE EXTENDING INTO THE MIXED PHASE LAYER...SO
WILL MENTION SLIGHT CHANCE FOR THUNDER. ANY SHOWERS THAT DO
DEVELOP WILL DISSIPATE EARLY EVENING WITH THE LOSS OF DAYTIME
HEATING.
TEMPS HAVE WARMED INTO THE MID/UPPER 70S...WITH A FEW LOCALES
HITTING 80 ACROSS THE PIEDMONT INTO CENTRAL VA. SOUTH WINDS AROUND
10 MPH TONIGHT ALONG WITH A PARTLY CLOUDY SKY WILL RESULT IN MILD
OVERNIGHT TEMPS. LOWS GENERALLY IN THE LOW 60S (~+1 STD DEV OR 10-12
DEGS ABOVE NORMAL).
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
GENERAL MODEL TRENDS CONTINUE TO SLOW THE UPPER SYSTEM SLIGHTLY AND
DIG IT FARTHER SOUTH AND WEST THROUGH FRIDAY NIGHT. CURRENT NATIONAL
RADAR TRENDS OVER THE OH VALLEY...DEPICT RATHER UNORGANIZED
CONVECTION ASSOCIATED WITH THE UPPER LOW. THE UPPER LOW PUSHES INTO
THE TN VALLEY AS A STRONG UPPER LOW DEEPENS OVER ERN CANADA. THE
FRONT REACHES THE ERN VA PIEDMONT LATE FRIDAY INTO EARLY FRI
EVENING. LEAD SHORTWAVE ENERGY ROUNDS THE BASE OF THE UPPER
TROUGH...LIFTING INTO THE REGION FRI AFTERNOON AHEAD OF THE MAIN
TROUGH ENERGY. RETURN FLOW ADVECTS DEEPER MOISTURE INTO THE
REGION...WITH H85 FLOW COMING IN FROM THE GULF STREAM. POPS RAMP UP
OVER THE PIEDMONT MID TO LATE MORNING...AND THEN POINTS EWD THROUGH
EARLY AFTERNOON. THE FAVORED AREAS FOR SHOWERS CONTINUE TO BE ALONG
AND SOUTH OF A LINE FROM FARMVILLE TO RICHMOND AND TO THE NRN
NECK/MD ERN SHORE FRI AFTERNOON AND FRIDAY EVENING. HAVE MAINTAINED
LIKELY POPS FOR THAT AREA. HAVE TRIMMED BACK POPS NORTH AND WEST OF
THIS LINE AS MODELS INDICATE SHOWER COVERAGE ASSOCIATED WITH THE
MAIN SHORTWAVE WILL BE LIMITED IN THAT REGION. THUNDERSTORM
POTENTIAL REMAINS MARGINAL DUE TO CONSIDERABLE CLOUD COVER AND
MARGINAL INSTABILITY. GIVEN THE DYNAMICS...THETA-E ADVECTION AND THE
TIME OF YEAR...WILL KEEP CHANCE MENTION OF THUNDER. SHEAR REMAINS
MODEST (AOB 30 KT)...SO EXPECT ONLY EMBEDDED THUNDER. PWATS CLIMB TO
1.25 TO 1.5 INCHES...WHICH MAY RESULT IN PERIODS OF MODERATE TO
LOCALLY HEAVY RAINFALL. HOWEVER...QPF AMOUNTS THRU FRIDAY EVENING
WILL GENERALLY RANGE FROM LESS THAN ONE QUARTER OF AN INCH ACROSS
THE NORTH UP TO ONE HALF INCH ACROSS THE SOUTH. AREA REMAINS IN WARM
SECTOR WITH RETURN FLOW PUSHING TEMPS BACK INTO THE MID/UPPER
70S...EVEN WITH CONSIDERABLE CLOUD COVER. SHORTWAVE DROPS OVER THE
CENTRAL APPALACHIANS INTO THE LOCAL AREA THRU FRI NIGHT AS THE FRONT
PUSHES OFFSHORE. WILL KEEP SOLID CHANCE POPS ALONG THE COAST THRU
THE OVERNIGHT PERIOD.
AFOREMENTIONED MODEL TRENDS MEAN LINGERING MID LEVEL MOISTURE TO
GO ALONG WITH THE STRONG DYNAMICS PROVIDED BY THE UPPER LOW DROPPING
OVER THE REGION SAT. WILL HOLD ONTO SOLID CHANCE POPS THROUGH LATE
MORNING INLAND FOR SCATTERED SHOWERS...AND ALONG THE COAST THRU SAT
AFTERNOON. CLOUDY CONDITIONS BECOME PARTLY CLOUDY INLAND SAT
AFTERNOON...BUT REMAIN MOSTLY CLOUDY ALONG THE COAST. TRENDED TOWARD
THE COOLER SIDE OF THE MOS GUIDANCE DUE TO CLOUD COVER AND MODEST
CAA...BUT TEMPS REMAIN SEASONABLE IN THE UPPER 60S/LOW 70S.
NORTH WINDS GENERALLY 10 TO 15 MPH WITH GUSTS OF 20 TO 25 MPH. TROUGH
AXIS PUSHES OFFSHORE SAT NIGHT WITH DRY CONDITIONS FORECAST ACROSS
THE AREA. LOWS IN THE MID/UPPER 40S INLAND TO LOW 50S NEAR THE COAST
UNDER A CLEAR SKY. HIGH PRESSURE BUILDS ACROSS NEW ENGLAND SAT
NIGHT...PARKING OFF THE NORTHEAST COAST SUNDAY. THE RESULT WILL BE
ONGOING DRY CONDITIONS. CAA WANES SUN...BUT LIGHT ONSHORE FLOW WILL
KEEP TEMPS IN CHECK. THICKNESSES YIELD TEMPS IN THE LOW/MID 70S
INLAND AND MID/UPPER 60S ALONG THE COAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE SLIDES FARTHER OFFSHORE SUNDAY NIGHT AND MONDAY...AND
SETTLES OFF THE SOUTHEAST COAST BY TUESDAY. MEANWHILE...A SHORTWAVE
TROUGH AND AN ASSOCIATED COLD FRONT APPROACH FROM THE NW BY TUESDAY
AFTN. MONDAY AND TUESDAY ARE TRENDING TOWARD BEING VERY WARM DAYS
WITH DEEP LAYER WSW FLOW ASSOCIATED WITH A BREAKING DOWN UPPER RIDGE
OVER THE E-CENTRAL/SERN CONUS. MODEL CONSENSUS GENERALLY SUPPORTS
850MB TEMPERATURES OF 12-15C...WHICH WITH FULL MIXING AND
DOWNSLOPING SHOULD EASILY PUSH HIGHS TO 80-85F W OF THE BAY...WITH
UPPER 70S FOR THE ERN SHORE. LOWS SUNDAY NIGHT SHOULD BE IN THE
LOW/MID 50S...WITH 55-60F MONDAY NIGHT. SKY COVER SHOULD GENERALLY
BE MOSTLY CLEAR/SUNNY SUNDAY NIGHT...MONDAY INTO MONDAY NIGHT...AND
BECOME PARTLY SUNNY TUESDAY. THE TROUGH AND COLD FRONT SWING THROUGH
THE AREA TUESDAY AFTN INTO TUESDAY NIGHT. THE MAIN FORCING
ASSOCIATED WITH THE MID/UPPER SHORTWAVE TROUGH GENERALLY PASSES N OF
THE LOCAL AREA...AND DEEP LAYER RH DIMINISHES AS THE FEATURE PASSES
OVER THE LOCAL AREA SO FORECAST POPS ARE ONLY 20%...WITH A NARROW
STRIP OF 30% ACROSS THE FAR N. HIGH PRESSURE BUILDS IN FROM THE N
WEDNESDAY...AND SLIDES OFFSHORE LATER IN THE WEEK. HIGHS WEDNESDAY
SHOULD DROP BACK TO THE MID/UPPER 60S NE...TO THE MID/UPPER 70S
FARTHER INLAND...AND THEN TREND UPWARD INTO THURSDAY AS THE HIGH
SLIDES OFFSHORE. LOWS SHOULD GENERALLY BE IN THE 50S.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
SURFACE HIGH PRESSURE REMAINS OFF THE SE COAST AS COLD FRONT AND
ASSOCIATED SURFACE TROUGH SLOWLY MOVE THROUGH THE MIDWEST.
SOUTHERLY FLOW CONTINUES TO INCREASE MOISTURE INTO THE MID-
ATLANTIC TOMORROW. EXPECT SW WIND GUST ~20KT FRI AFTN WITH THE
POTENTIAL FOR MVFR CIGS. AHEAD OF THE FRONT...DAYTIME HEATING AND
INCREASING MOISTURE ALONG WITH SHORTWAVE ENERGY MOVING OVER THE
REGION WILL INCREASE THE POTENTIAL FOR AFTN SHOWERS AND TSTMS.
GUSTY WINDS AND HEAVY RAIN WILL BE POSSIBLE IN ANY STORM.
FRONT PASSES OF THE COAST LATE FRI/EARLY SAT. TRAILING CLOSED UPPER
LOW WILL CAUSE LAPSE RATES TO INCREASE...CONTINUING THE
POSSIBILITY FOR MVFR CIGS AND STORM DEVELOPMENT INTO SAT. DRIER
AIR AND VFR CONDITIONS RETURN LATE SAT NIGHT.
&&
.MARINE...
HIGH PRESSURE IS SITUATED WELL OFFSHORE THIS AFTN...WITH
LOW PRESSURE WELL TO THE W OVER THE MID-MISSISSIPPI VALLEY. THE HIGH
WILL CONTINUE TO SLIDE FARTHER OFFSHORE TONIGHT AS LOW PRESSURE
LIFTS NE OVER THE GREAT LAKES. A SW WIND SHOULD AVERAGE 10-15KT
THROUGH THIS EVENING...AND THEN INCREASE TO 15KT BAY/15-20KT OCEAN
LATER THIS EVENING THROUGH FRIDAY MORNING...BEFORE DIMINISHING
FRIDAY AFTN/EVENING AS THE PRESSURE GRADIENT SLACKENS AS A WEAK COLD
FRONT GRADUALLY DROPS INTO THE REGION. THE COLD FRONT PUSHES THROUGH
THE AREA EARLY SATURDAY MORNING...WITH A SUBSEQUENT NORTHERLY SURGE
MIDDAY SATURDAY...WITH A SECONDARY SURGE SATURDAY EVENING. MARGINAL
SCA CONDITIONS ARE POSSIBLE OVER THE BAY (15-20KT N WIND). HIGH
PRESSURE BUILDS OVER THE AREA SATURDAY NIGHT AND SUNDAY...SLIDES
OFFSHORE MONDAY...AND SETTLES OFF THE SOUTHEAST COAST TUESDAY. SEAS
GENERALLY AVERAGE 2-4FT...WITH 2-3FT WAVES IN THE BAY.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SAM/TMG
NEAR TERM...MAS/SAM
SHORT TERM...SAM
LONG TERM...AJZ
AVIATION...ALB/DAP
MARINE...AJZ
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
912 PM EDT THU APR 21 2016
.SYNOPSIS...
HIGH PRESSURE REMAINS OVER THE WESTERN ATLANTIC TONIGHT. A COLD
FRONT WILL APPROACH FROM THE WEST FRIDAY...PUSHING OFF THE COAST
EARLY SATURDAY MORNING. AN UPPER LEVEL DISTURBANCE DROPS OVER THE
REGION SATURDAY. HIGH PRESSURE RETURNS FOR SATURDAY NIGHT INTO
MONDAY. THE NEXT COLD FRONT PUSHES ACROSS THE REGION TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
LATEST REGIONAL RADAR MOSAIC DEPICTS ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS EXTENDING FROM SE NC INTO CENTRAL NC THIS
AFTERNOON. BASED ON LATEST SFC OBS...THE WARM FRONT HAS LIFTED INTO
THE LOCAL AREA...WITH BETTER DESTABILIZATION SOUTH OF THE LOCAL
AREA. EXPECT THE BETTER INSTABILITY TO REMAIN SOUTH OF THE
REGION...BUT HI-RES GUIDANCE CONTINUES TO INDICATE THE POTENTIAL FOR
ISOLATED TO WIDELY SCATTERED SHOWERS LIFTING INTO SRN VA AND NE NC
THRU LATE THIS AFTERNOON. NAM12 300K SURFACES BACK UP THIS
SCENARIO...INDICATING LOW LEVEL LIFT EVEN UNDER THE UPPER LEVEL RIDGE
LOCATED OVER THE ERN CONUS. RAP SOUNDINGS INDICATE MODEST CAPE
EXTENDING INTO THE MIXED PHASE LAYER...SO WILL MENTION SLIGHT CHANCE
FOR THUNDER. ANY SHOWERS THAT DO DEVELOP WILL DISSIPATE EARLY
EVENING WITH THE LOSS OF DAYTIME HEATING.
TEMPS HAVE WARMED INTO THE MID/UPPER 70S...WITH A FEW LOCALES
HITTING 80 ACROSS THE PIEDMONT INTO CENTRAL VA. SOUTH WINDS AROUND
10 MPH TONIGHT ALONG WITH A PARTLY CLOUDY SKY WILL RESULT IN MILD
OVERNIGHT TEMPS. LOWS GENERALLY IN THE LOW 60S (~+1 STD DEV OR 10-12
DEGS ABOVE NORMAL).
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
GENERAL MODEL TRENDS CONTINUE TO SLOW THE UPPER SYSTEM SLIGHTLY AND
DIG IT FARTHER SOUTH AND WEST THROUGH FRIDAY NIGHT. CURRENT NATIONAL
RADAR TRENDS OVER THE OH VALLEY...DEPICT RATHER UNORGANIZED
CONVECTION ASSOCIATED WITH THE UPPER LOW. THE UPPER LOW PUSHES INTO
THE TN VALLEY AS A STRONG UPPER LOW DEEPENS OVER ERN CANADA. THE
FRONT REACHES THE ERN VA PIEDMONT LATE FRIDAY INTO EARLY FRI
EVENING. LEAD SHORTWAVE ENERGY ROUNDS THE BASE OF THE UPPER
TROUGH...LIFTING INTO THE REGION FRI AFTERNOON AHEAD OF THE MAIN
TROUGH ENERGY. RETURN FLOW ADVECTS DEEPER MOISTURE INTO THE
REGION...WITH H85 FLOW COMING IN FROM THE GULF STREAM. POPS RAMP UP
OVER THE PIEDMONT MID TO LATE MORNING...AND THEN POINTS EWD THROUGH
EARLY AFTERNOON. THE FAVORED AREAS FOR SHOWERS CONTINUE TO BE ALONG
AND SOUTH OF A LINE FROM FARMVILLE TO RICHMOND AND TO THE NRN
NECK/MD ERN SHORE FRI AFTERNOON AND FRIDAY EVENING. HAVE MAINTAINED
LIKELY POPS FOR THAT AREA. HAVE TRIMMED BACK POPS NORTH AND WEST OF
THIS LINE AS MODELS INDICATE SHOWER COVERAGE ASSOCIATED WITH THE
MAIN SHORTWAVE WILL BE LIMITED IN THAT REGION. THUNDERSTORM
POTENTIAL REMAINS MARGINAL DUE TO CONSIDERABLE CLOUD COVER AND
MARGINAL INSTABILITY. GIVEN THE DYNAMICS...THETA-E ADVECTION AND THE
TIME OF YEAR...WILL KEEP CHANCE MENTION OF THUNDER. SHEAR REMAINS
MODEST (AOB 30 KT)...SO EXPECT ONLY EMBEDDED THUNDER. PWATS CLIMB TO
1.25 TO 1.5 INCHES...WHICH MAY RESULT IN PERIODS OF MODERATE TO
LOCALLY HEAVY RAINFALL. HOWEVER...QPF AMOUNTS THRU FRIDAY EVENING
WILL GENERALLY RANGE FROM LESS THAN ONE QUARTER OF AN INCH ACROSS
THE NORTH UP TO ONE HALF INCH ACROSS THE SOUTH. AREA REMAINS IN WARM
SECTOR WITH RETURN FLOW PUSHING TEMPS BACK INTO THE MID/UPPER
70S...EVEN WITH CONSIDERABLE CLOUD COVER. SHORTWAVE DROPS OVER THE
CENTRAL APPALACHIANS INTO THE LOCAL AREA THRU FRI NIGHT AS THE FRONT
PUSHES OFFSHORE. WILL KEEP SOLID CHANCE POPS ALONG THE COAST THRU
THE OVERNIGHT PERIOD.
AFOREMENTIONED MODEL TRENDS MEAN LINGERING MID LEVEL MOISTURE TO
GO ALONG WITH THE STRONG DYNAMICS PROVIDED BY THE UPPER LOW DROPPING
OVER THE REGION SAT. WILL HOLD ONTO SOLID CHANCE POPS THROUGH LATE
MORNING INLAND FOR SCATTERED SHOWERS...AND ALONG THE COAST THRU SAT
AFTERNOON. CLOUDY CONDITIONS BECOME PARTLY CLOUDY INLAND SAT
AFTERNOON...BUT REMAIN MOSTLY CLOUDY ALONG THE COAST. TRENDED TOWARD
THE COOLER SIDE OF THE MOS GUIDANCE DUE TO CLOUD COVER AND MODEST
CAA...BUT TEMPS REMAIN SEASONABLE IN THE UPPER 60S/LOW 70S.
NORTH WINDS GENERALLY 10 TO 15 MPH WITH GUSTS OF 20 TO 25 MPH. TROUGH
AXIS PUSHES OFFSHORE SAT NIGHT WITH DRY CONDITIONS FORECAST ACROSS
THE AREA. LOWS IN THE MID/UPPER 40S INLAND TO LOW 50S NEAR THE COAST
UNDER A CLEAR SKY. HIGH PRESSURE BUILDS ACROSS NEW ENGLAND SAT
NIGHT...PARKING OFF THE NORTHEAST COAST SUNDAY. THE RESULT WILL BE
ONGOING DRY CONDITIONS. CAA WANES SUN...BUT LIGHT ONSHORE FLOW WILL
KEEP TEMPS IN CHECK. THICKNESSES YIELD TEMPS IN THE LOW/MID 70S
INLAND AND MID/UPPER 60S ALONG THE COAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE SLIDES FARTHER OFFSHORE SUNDAY NIGHT AND MONDAY...AND
SETTLES OFF THE SOUTHEAST COAST BY TUESDAY. MEANWHILE...A SHORTWAVE
TROUGH AND AN ASSOCIATED COLD FRONT APPROACH FROM THE NW BY TUESDAY
AFTN. MONDAY AND TUESDAY ARE TRENDING TOWARD BEING VERY WARM DAYS
WITH DEEP LAYER WSW FLOW ASSOCIATED WITH A BREAKING DOWN UPPER RIDGE
OVER THE E-CENTRAL/SERN CONUS. MODEL CONSENSUS GENERALLY SUPPORTS
850MB TEMPERATURES OF 12-15C...WHICH WITH FULL MIXING AND
DOWNSLOPING SHOULD EASILY PUSH HIGHS TO 80-85F W OF THE BAY...WITH
UPPER 70S FOR THE ERN SHORE. LOWS SUNDAY NIGHT SHOULD BE IN THE
LOW/MID 50S...WITH 55-60F MONDAY NIGHT. SKY COVER SHOULD GENERALLY
BE MOSTLY CLEAR/SUNNY SUNDAY NIGHT...MONDAY INTO MONDAY NIGHT...AND
BECOME PARTLY SUNNY TUESDAY. THE TROUGH AND COLD FRONT SWING THROUGH
THE AREA TUESDAY AFTN INTO TUESDAY NIGHT. THE MAIN FORCING
ASSOCIATED WITH THE MID/UPPER SHORTWAVE TROUGH GENERALLY PASSES N OF
THE LOCAL AREA...AND DEEP LAYER RH DIMINISHES AS THE FEATURE PASSES
OVER THE LOCAL AREA SO FORECAST POPS ARE ONLY 20%...WITH A NARROW
STRIP OF 30% ACROSS THE FAR N. HIGH PRESSURE BUILDS IN FROM THE N
WEDNESDAY...AND SLIDES OFFSHORE LATER IN THE WEEK. HIGHS WEDNESDAY
SHOULD DROP BACK TO THE MID/UPPER 60S NE...TO THE MID/UPPER 70S
FARTHER INLAND...AND THEN TREND UPWARD INTO THURSDAY AS THE HIGH
SLIDES OFFSHORE. LOWS SHOULD GENERALLY BE IN THE 50S.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
SURFACE HIGH PRESSURE REMAINS OFF THE SE COAST AS COLD FRONT AND
ASSOCIATED SURFACE TROUGH SLOWLY MOVE THROUGH THE MIDWEST.
SOUTHERLY FLOW CONTINUES TO INCREASE MOISTURE INTO THE MID-
ATLANTIC TOMORROW. EXPECT SW WIND GUST ~20KT FRI AFTN WITH THE
POTENTIAL FOR MVFR CIGS. AHEAD OF THE FRONT...DAYTIME HEATING AND
INCREASING MOISTURE ALONG WITH SHORTWAVE ENERGY MOVING OVER THE
REGION WILL INCREASE THE POTENTIAL FOR AFTN SHOWERS AND TSTMS.
GUSTY WINDS AND HEAVY RAIN WILL BE POSSIBLE IN ANY STORM.
FRONT PASSES OF THE COAST LATE FRI/EARLY SAT. TRAILING CLOSED UPPER
LOW WILL CAUSE LAPSE RATES TO INCREASE...CONTINUING THE
POSSIBILITY FOR MVFR CIGS AND STORM DEVELOPMENT INTO SAT. DRIER
AIR AND VFR CONDITIONS RETURN LATE SAT NIGHT.
&&
.MARINE...
HIGH PRESSURE IS SITUATED WELL OFFSHORE THIS AFTN...WITH
LOW PRESSURE WELL TO THE W OVER THE MID-MISSISSIPPI VALLEY. THE HIGH
WILL CONTINUE TO SLIDE FARTHER OFFSHORE TONIGHT AS LOW PRESSURE
LIFTS NE OVER THE GREAT LAKES. A SW WIND SHOULD AVERAGE 10-15KT
THROUGH THIS EVENING...AND THEN INCREASE TO 15KT BAY/15-20KT OCEAN
LATER THIS EVENING THROUGH FRIDAY MORNING...BEFORE DIMINISHING
FRIDAY AFTN/EVENING AS THE PRESSURE GRADIENT SLACKENS AS A WEAK COLD
FRONT GRADUALLY DROPS INTO THE REGION. THE COLD FRONT PUSHES THROUGH
THE AREA EARLY SATURDAY MORNING...WITH A SUBSEQUENT NORTHERLY SURGE
MIDDAY SATURDAY...WITH A SECONDARY SURGE SATURDAY EVENING. MARGINAL
SCA CONDITIONS ARE POSSIBLE OVER THE BAY (15-20KT N WIND). HIGH
PRESSURE BUILDS OVER THE AREA SATURDAY NIGHT AND SUNDAY...SLIDES
OFFSHORE MONDAY...AND SETTLES OFF THE SOUTHEAST COAST TUESDAY. SEAS
GENERALLY AVERAGE 2-4FT...WITH 2-3FT WAVES IN THE BAY.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SAM/TMG
NEAR TERM...SAM
SHORT TERM...SAM
LONG TERM...AJZ
AVIATION...DAP
MARINE...AJZ
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
725 PM EDT THU APR 21 2016
.SYNOPSIS...
LOW PRESSURE WILL BRING PERIODIC SHOWER CHANCES THROUGH FRIDAY
EVENING. HIGH PRESSURE WILL BRING DRY AND SEASONAL WEATHER THIS
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
QUICK UPDATE TO THE FORECAST TO ADD MENTION OF ISOLATED
THUNDERSTORMS AS LATEST RADAR SHOWS A FEW RELATIVELY WEAK STORMS
POP UP OVER EASTERN OHIO /WESTERN PA. LATEST RAPID UPDATE RUNS
PICK THIS UP REASONABLY WELL SO HAVE ALSO WEIGHTED POPS OVER THE
NEXT SEVERAL HOURS TOWARDS THE LATEST HRRR AND RAP. HOURLY
TEMPERATURES ACROSS WESTERN ZONES WERE ALSO ADJUSTED DOWN AS RAIN
FALLING THROUGH THE INITIALLY VERY DRY LOWER LEVELS QUICKLY
LOWERED TEMPERATURES A COUPLE DEGREES.
SHOWERS ARE EXPECTED TO INCREASE IN COVERAGE LATE THIS
EVENING...PRIMARILY WEST OF LINE RUNNING ROUGHLY FROM INDIANA TO
PARKERSBURG AS A SHORTWAVE TROUGH TRANSITIONS NORTHEAST ACROSS THE
UPPER OHIO VALLEY AHEAD OF THE PARENT UPPER LOW. ITS POSSIBLE WE
MAY NEED TO INCLUDE MENTION OF ISOLATED THUNDERSTORMS WITH THE
NEXT UPDATE AS WELL AS THERE IS SOME ELEVATED INSTABILITY ON
LATEST MODEL SOUNDINGS...AND THE CROSSING SHORTWAVE MAY BE JUST
ENOUGH OF A KICKER. AT THE MOMENT...THE PROGGED INSTABILITY IS
JUST TOO WEAK. OVERNIGHT LOW TEMPERATURES WILL RANGE 10-15 DEG
ABOVE NORMAL WITH CONTINUED WARM AIR ADVECTION AND CLOUD COVERAGE
LIMITING ANY RADIATIONAL COOLING.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
SHOWERS SHOULD TAPER OFF IN COVERAGE FRI MRNG AS THE INITIAL
SHORTWAVE EXITS. THE UPR LOW/TROF...AND IT/S ASSOCIATED SFC COLD
FRONT...IS EXPECTED TO ADVANCE E TWD THE AREA BY AFTN WITH
INCREASING SHOWER POTENTIAL RETURNING. MODEL PROGS SHOW A
POTENTIAL FOR WEAK INSTABILITY...SO ONLY INCLUDED A SLGT CHC OF A
TSTM. THE FRONT SHOULD COMPLETE IT/S PASSAGE FRI NIGHT...THOUGH
SHOWER CHCS SHOULD CONTINUE UNTIL THE UPR TROF AXIS MOVES E OF
THE AREA SAT MRNG.
BUILDING RIDGING IS THEN EXPECTED TO BRING DRY WEATHER THROUGH
THE REST OF THE WEEKEND. TEMPERATURES ARE EXPECTED TO AVERAGE
NEAR OR SEVERAL DEGREES ABOVE SEASONAL LVLS USING GFS MOS AND A
CONSENSUS BLEND GUIDANCE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A COLD FRONT WILL SLOWLY CROSS THE REGION LATER MONDAY THROUGH
TUESDAY BRINGING SHOWERS. BUBBLE OF HIGH PRESSURE WITH DRY BUT
STILL MILD CONDITIONS WEDNESDAY. LOW PRESSURE ADVANCING FROM THE
NATIONS MID SECTION WILL RETURN SHOWERS FOR LATE WEEK. A SLIGHTLY
MODIFIED SUPERBLEND WAS USED FOR THE EXTENDED FORECAST.
&&
.AVIATION /23Z THURSDAY THROUGH TUESDAY/...
WIND HAS BEEN QUITE VARIABLE IN DIRECTION DURING THE LATE
AFTERNOON AT SEVERAL SITES AS SCATTERED SHOWERS MOVE ACROSS THE
REGION. THINK THIS WILL CONTINUE TO BE THE CASE THROUGH THE
EVENING HOURS...WITH A MORE UNIFORM WIND OUT OF THE SOUTH
DEVELOPING AFTER MIDNIGHT.
THERE WILL BE A BRIEF PERIOD WHERE AN ISOLATED THUNDERSTORM IS
POSSIBLE TONIGHT...BUT THE STORM THAT MOVED TO THE NORTH OF
PITTSBURGH APPEARS TO HAVE WEAKENED ENOUGH THAT THUNDER SHOULD NOT
BE A CONCERN AT DUJ OR OTHER SITES. ALTHOUGH CONDITIONS WILL
INITIALLY BE VFR AT THE START OF THE TAF PERIOD...SCATTERED
SHOWERS WILL BECOME MORE WIDESPREAD AFTER MIDNIGHT AS DEEPER
MOISTURE ENTERS THE REGION AND YIELDS MVFR RESTRICTIONS. AFTER A
BIT OF A LULL IN SHOWERS FRIDAY MORNING...SHOWERS WILL INCREASE IN
COVERAGE AGAIN FRIDAY AFTERNOON...WITH CEILINGS LIKELY TO RISE
BACK TO VFR CATEGORY.
.OUTLOOK /FRIDAY NIGHT THROUGH TUESDAY/...
RESTRICTIONS ARE EXPECTED FRIDAY NIGHT WITH IFR CEILINGS POSSIBLE
AS LOW PRESSURE MOVES EAST. THE NEXT CHANCE FOR WIDESPREAD
RESTRICTIONS WILL BE MONDAY NIGHT AND TUESDAY AS A COLD FRONT
APPROACHES.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
936 PM EDT THU APR 21 2016
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 327 PM EDT THU APR 21 2016
AFTER SHOWERS AND ISOLATED THUNDERSTORMS EXIT THE AREA EARLY
TONIGHT...CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN SUNDAY AND
CONTINUE WELL INTO NEXT WEEK. SUNDAY WILL BE WARM WITH TEMPERATURES
APPROACHING 70 IN SOME SPOTS. AFTERWARDS...HIGHS WILL BE NEAR
OR SLIGHTLY ABOVE NORMAL WITH HIGHS IN THE LOWER TO MID 60S.
&&
.UPDATE...
ISSUED AT 936 PM EDT THU APR 21 2016
WE HAVE UPDATED THE FCST THIS EVENING TO FRESHEN UP PCPN
TRENDS...PULL THUNDER...AND ADD MORE FOG TO THE FCST AREA-WIDE.
A FEW STORMS TRIED TO MAKE IT UP INTO THE AREA FROM THE S/SW...BUT
COULDN/T QUITE MAKE IT WITH THE LACK OF INSTABILITY UP THIS WAY
WITH ALL OF THE CLOUD COVER TODAY. MODELS ALL SHOW THE INSTABILITY
WILL BE STEADILY ON THE WANE THROUGH THE NIGHT...SO WE PULLED IT
ALTOGETHER.
A FEW SHOWERS ARE AFFECTING THE SE CORNER OF THE CWFA THIS EVENING
LEFT OVER FROM CONVECTION FROM EARLIER ACROSS INDIANA. THESE WILL
BE MOVING OUT SOON...LEAVING ONLY A SMALL CHC OF A SHOWER
OVERNIGHT AS THE SECONDARY FRONT DROPS THROUGH THE AREA.
FOG LOOKS TO BE A LITTLE MORE LIKELY...ESPECIALLY WITH SOME
CLEARING WORKING THROUGH THE SRN TWO THIRDS OF THE CWFA THIS
EVENING. WINDS ARE STILL RELATIVELY LIGHT...AND COULD REMAIN THAT
WAY RIGHT AT THE SFC ALL NIGHT. SOME BETTER MIXING ALOFT WILL MOVE
IN BEHIND THE FRONT. WE EXPECT SOME FOG DEVELOPING...WITH THE
BIGGER ISSUE BEING STRATUS EXPECTED TO MOVE IN FROM THE NORTH
OVERNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 327 PM EDT THU APR 21 2016
EXPERIMENTAL HRRR GUIDANCE IS LOOKING ON TRACK AS CLEARING HAS
SPREAD INTO EXTREME SOUTHWEST LOWER MI AND A THUNDERSTORM ALREADY
HAS DEVELOPED OVER NORTHWEST INDIANA. BASED ON EXPECTED MOVEMENT
TO THE NORTHEAST...WE STILL EXPECT THE BEST CHANCES FOR THUNDERSTORMS
WILL BE SOUTH OF I-96 AND EAST OF KALAMAZOO MAINLY BEFORE MIDNIGHT.
AFTER THIS EXPECT AT LEAST SOME PATCHY FOG NEAR THE I-94 CORRIDOR
THE REST OF THE NIGHT.
AFTER TONIGHT...FORECAST CONCERNS ARE MINIMAL WITH RAIN SHOWERS
APPROACHING FROM THE NORTHWEST ON SATURDAY NIGHT.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 327 PM EDT THU APR 21 2016
A STATIONARY FRONT IS STILL EXPECTED TO SLIDE SLOWLY SOUTH THROUGH
THE CWA SUNDAY INTO MONDAY NIGHT. THIS FRONT WILL HAVE A SOLID GULF
MOISTURE CONNECTION AND THE OVER RIDING ACROSS THIS FRONT SHOULD
PRODUCE A FAIR AMOUNT OF RAIN. IT APPEARS MOST AREAS SHOULD GET A
AROUND AN INCH OF RAIN. THE STEADIEST RAINS SHOULD OCCUR ACROSS
CENTRAL LOWER WHERE THE BEST LIFT PERSISTS ACROSS THE FRONT...AND
OVER AN INCH OF RAIN CERTAINLY SEEMS POSSIBLE HERE. A BIT LIGHTER
RAINS ARE EXPECTED TOWARD I-94. A FEW CLAPS OF THUNDER WILL BE
POSSIBLE BUT NO SEVERE WEATHER IS EXPECTED AT THIS TIME. THE AREA
SHOULD DRY OUT INTO TUESDAY AS A WAVE OF LOW PRESSURE SLIDES ALONG
THE FRONT AND HEADS EAST.
HOWEVER THE DRY SPELL APPEARS BRIEF AS MORE RAIN CHANCES RETURN FOR
WEDNESDAY AND THURSDAY WITH ANOTHER WAVE OF LOW PRESSURE MOVING
ACROSS THE OHIO VALLEY. SIMILAR PATTERN WITH A GOOD CHANCE OF
RAIN...BUT MINIMAL CHANCES FOR SEVERE STORMS.
WE WILL REMAIN MILD UNTIL THE FRONT COMES THROUGH...WITH A COOLER
PERIOD FOR TUESDAY AND WEDNESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 755 PM EDT THU APR 21 2016
SCATTERED SHOWERS/ISOLATED TSTMS SHOULD BE CONFINED TO AREAS
SOUTH AND EAST OF GRR THIS EVENING WITH CONDITIONS RANGING FROM
VFR TO MVFR. LOW CONFIDENCE FORECAST THIS EVENING AT MKG AS LAKE
FOG HAS BEEN OSCILLATING BACK AND FORTH BUT WILL KEEP IT VFR THERE
UNTIL MIDNIGHT OR SO WHEN LIGHT WESTERLY FLOW REDEVELOPS. THIS
SHOULD SEND THE LAKE STRATUS/FOG BACK INLAND.
IFR/LIFR EXPECTED TO BECOME MORE WIDESPREAD LATE TONIGHT DUE TO
MOIST BOUNDARY LAYER CONDITIONS AND LIGHT WINDS. THE LOWER
CIGS/VSBYS WILL LINGER THROUGH ABOUT 15Z FRIDAY THEN LIFT TO MVFR
TO VFR LEVELS IN THE AFTERNOON AS WINDS INCREASE OUT OF THE NORTH
AND SEND DRIER AIR INTO THE REGION.
&&
.MARINE...
ISSUED AT 327 PM EDT THU APR 21 2016
FOG HAS BECOME CONSIDERABLY THICKER IN THE LAST COUPLE HOURS SO IN
COORDINATION WITH IWX HAVE HOISTED A MARINE DENSE FOG ADVISORY.
FOG WILL GET SWEPT OUT OVERNIGHT WHEN STRONG NORTH WINDS SPREAD
SOUTH ACROSS LAKE MICHIGAN. RAPIDLY GROWING WAVES WITH THE
STRONGER WINDS AND A VERY FAVORABLE LONG FETCH WILL GIVE US SMALL
CRAFT ADVISORY CONDITIONS QUICKLY FRIDAY MORNING SO HAVE ALSO
ISSUED A SMALL CRAFT ADVISORY WITH THIS PACKAGE.
&&
.HYDROLOGY...
ISSUED AT 158 PM EDT THU APR 21 2016
RAINFALL LAST NIGHT AND TODAY HAS BEEN LIGHT IN NATURE... WITH FEW
TOTALS EXCEEDING A QUARTER INCH. LEVELS ON MAIN STEM RIVERS CONTINUE
A GRADUAL DECLINE... BUT WE HAVE BEEN SEEING RISES ON SMALLER RIVERS
AND CREEKS. NO FLOODING IN ANTICIPATED TODAY OR TOMORROW.
AFTER A QUIET FRIDAY AND SATURDAY... SUNDAY THROUGH THE REST OF NEXT
WEEK LOOKS FAIRLY ACTIVE. A WIDESPREAD INCH OF RAINFALL IS CERTAINLY
POSSIBLE. RIVERS REMAIN ELEVATED... SO WE COULD SEE SOME RISE ABOVE
BANKFULL AND PRODUCE MINOR FLOODING IN LOWLAND AREAS NEXT WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...DENSE FOG ADVISORY UNTIL 2 AM EDT FRIDAY FOR LMZ844>849.
SMALL CRAFT ADVISORY FROM 8 AM FRIDAY TO 2 AM EDT SATURDAY FOR
LMZ844>849.
&&
$$
UPDATE...NJJ
SYNOPSIS...TJT
SHORT TERM...TJT
LONG TERM...JK
AVIATION...MEADE
HYDROLOGY...EBW
MARINE...TJT
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
755 PM EDT THU APR 21 2016
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 327 PM EDT THU APR 21 2016
AFTER SHOWERS AND ISOLATED THUNDERSTORMS EXIT THE AREA EARLY
TONIGHT...CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN SUNDAY AND
CONTINUE WELL INTO NEXT WEEK. SUNDAY WILL BE WARM WITH TEMPERATURES
APPROACHING 70 IN SOME SPOTS. AFTERWARDS...HIGHS WILL BE NEAR
OR SLIGHTLY ABOVE NORMAL WITH HIGHS IN THE LOWER TO MID 60S.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 327 PM EDT THU APR 21 2016
EXPERIMENTAL HRRR GUIDANCE IS LOOKING ON TRACK AS CLEARING HAS
SPREAD INTO EXTREME SOUTHWEST LOWER MI AND A THUNDERSTORM ALREADY
HAS DEVELOPED OVER NORTHWEST INDIANA. BASED ON EXPECTED MOVEMENT
TO THE NORTHEAST...WE STILL EXPECT THE BEST CHANCES FOR THUNDERSTORMS
WILL BE SOUTH OF I-96 AND EAST OF KALAMAZOO MAINLY BEFORE MIDNIGHT.
AFTER THIS EXPECT AT LEAST SOME PATCHY FOG NEAR THE I-94 CORRIDOR
THE REST OF THE NIGHT.
AFTER TONIGHT...FORECAST CONCERNS ARE MINIMAL WITH RAIN SHOWERS
APPROACHING FROM THE NORTHWEST ON SATURDAY NIGHT.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 327 PM EDT THU APR 21 2016
A STATIONARY FRONT IS STILL EXPECTED TO SLIDE SLOWLY SOUTH THROUGH
THE CWA SUNDAY INTO MONDAY NIGHT. THIS FRONT WILL HAVE A SOLID GULF
MOISTURE CONNECTION AND THE OVER RIDING ACROSS THIS FRONT SHOULD
PRODUCE A FAIR AMOUNT OF RAIN. IT APPEARS MOST AREAS SHOULD GET A
AROUND AN INCH OF RAIN. THE STEADIEST RAINS SHOULD OCCUR ACROSS
CENTRAL LOWER WHERE THE BEST LIFT PERSISTS ACROSS THE FRONT...AND
OVER AN INCH OF RAIN CERTAINLY SEEMS POSSIBLE HERE. A BIT LIGHTER
RAINS ARE EXPECTED TOWARD I-94. A FEW CLAPS OF THUNDER WILL BE
POSSIBLE BUT NO SEVERE WEATHER IS EXPECTED AT THIS TIME. THE AREA
SHOULD DRY OUT INTO TUESDAY AS A WAVE OF LOW PRESSURE SLIDES ALONG
THE FRONT AND HEADS EAST.
HOWEVER THE DRY SPELL APPEARS BRIEF AS MORE RAIN CHANCES RETURN FOR
WEDNESDAY AND THURSDAY WITH ANOTHER WAVE OF LOW PRESSURE MOVING
ACROSS THE OHIO VALLEY. SIMILAR PATTERN WITH A GOOD CHANCE OF
RAIN...BUT MINIMAL CHANCES FOR SEVERE STORMS.
WE WILL REMAIN MILD UNTIL THE FRONT COMES THROUGH...WITH A COOLER
PERIOD FOR TUESDAY AND WEDNESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 755 PM EDT THU APR 21 2016
SCATTERED SHOWERS/ISOLATED TSTMS SHOULD BE CONFINED TO AREAS
SOUTH AND EAST OF GRR THIS EVENING WITH CONDITIONS RANGING FROM
VFR TO MVFR. LOW CONFIDENCE FORECAST THIS EVENING AT MKG AS LAKE
FOG HAS BEEN OSCILLATING BACK AND FORTH BUT WILL KEEP IT VFR THERE
UNTIL MIDNIGHT OR SO WHEN LIGHT WESTERLY FLOW REDEVELOPS. THIS
SHOULD SEND THE LAKE STRATUS/FOG BACK INLAND.
IFR/LIFR EXPECTED TO BECOME MORE WIDESPREAD LATE TONIGHT DUE TO
MOIST BOUNDARY LAYER CONDITIONS AND LIGHT WINDS. THE LOWER
CIGS/VSBYS WILL LINGER THROUGH ABOUT 15Z FRIDAY THEN LIFT TO MVFR
TO VFR LEVELS IN THE AFTERNOON AS WINDS INCREASE OUT OF THE NORTH
AND SEND DRIER AIR INTO THE REGION.
&&
.MARINE...
ISSUED AT 327 PM EDT THU APR 21 2016
FOG HAS BECOME CONSIDERABLY THICKER IN THE LAST COUPLE HOURS SO IN
COORDINATION WITH IWX HAVE HOISTED A MARINE DENSE FOG ADVISORY.
FOG WILL GET SWEPT OUT OVERNIGHT WHEN STRONG NORTH WINDS SPREAD
SOUTH ACROSS LAKE MICHIGAN. RAPIDLY GROWING WAVES WITH THE
STRONGER WINDS AND A VERY FAVORABLE LONG FETCH WILL GIVE US SMALL
CRAFT ADVISORY CONDITIONS QUICKLY FRIDAY MORNING SO HAVE ALSO
ISSUED A SMALL CRAFT ADVISORY WITH THIS PACKAGE.
&&
.HYDROLOGY...
ISSUED AT 158 PM EDT THU APR 21 2016
RAINFALL LAST NIGHT AND TODAY HAS BEEN LIGHT IN NATURE... WITH FEW
TOTALS EXCEEDING A QUARTER INCH. LEVELS ON MAIN STEM RIVERS CONTINUE
A GRADUAL DECLINE... BUT WE HAVE BEEN SEEING RISES ON SMALLER RIVERS
AND CREEKS. NO FLOODING IN ANTICIPATED TODAY OR TOMORROW.
AFTER A QUIET FRIDAY AND SATURDAY... SUNDAY THROUGH THE REST OF NEXT
WEEK LOOKS FAIRLY ACTIVE. A WIDESPREAD INCH OF RAINFALL IS CERTAINLY
POSSIBLE. RIVERS REMAIN ELEVATED... SO WE COULD SEE SOME RISE ABOVE
BANKFULL AND PRODUCE MINOR FLOODING IN LOWLAND AREAS NEXT WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...DENSE FOG ADVISORY UNTIL 2 AM EDT FRIDAY FOR LMZ844>849.
SMALL CRAFT ADVISORY FROM 8 AM FRIDAY TO 2 AM EDT SATURDAY FOR
LMZ844>849.
&&
$$
SYNOPSIS...TJT
SHORT TERM...TJT
LONG TERM...JK
AVIATION...MEADE
HYDROLOGY...EBW
MARINE...TJT
AREA FORECAST DISCUSSION
NWS JACKSON MS
430 PM CDT WED APR 20 2016
.DISCUSSION...A COLD FRONT CONTINUES TO PUSH SLOWLY TOWARD THE
REGION WITH THE BOUNDARY NOW BACK IN THE ARKLATEX AND HEADED THIS
WAY. HOWEVER...THE MAIN BAND OF SHOWERS AND THUNDERSTORMS (NOW
COMING INTO WESTERN PORTIONS OF THE FORECAST AREA) IS BEING
TRIGGERED BY A WEAK SURFACE TROUGH RUNNING OUT A DECENT WAYS IN
ADVANCE OF THE FRONT. REGIONAL RADARS REVEAL A FEW ROBUST CELLS WITH
A FAIR AMOUNT OF LIGHTNING AND HEAVY DOWNPOURS APPROACHING THE MS
RIVER...AND ONLY ISOLATED CELLS BETWEEN THE MS RIVER AND I-55.
FORTUNATELY...ATMOSPHERIC INSTABILITY IS NOT HIGH AND WIND SHEAR IS
REALLY INSUFFICIENT TO ORGANIZE STORMS INTO MODES THAT WOULD BE MORE
WORRISOME FOR SEVERE WEATHER.
EXPECTING ALL THIS ACTIVITY TO CONTINUE TO TREND EAST THROUGH THIS
EVENING...WORKING INTO THE I-55 CORRIDOR BY EARLY THIS EVENING.
LATEST HIRES HRRR RUNS STILL SUGGEST A WEST TO EAST GRADIENT OF FUEL
(MOISTURE ADVECTION AND INSTABILITY) CATALYZING STORMS WILL DROP OFF
QUICKLY EAST OF I-55...SO EXPECT LATER THIS EVENING THAT CONVECTION
WILL HAVE A VERY DIFFICULT TIME GETTING MUCH INTO EASTERN MS.
HOWEVER...I AM SLIGHTLY WORRIED THAT THE EXPECTED STALLING NORTH TO
SOUTH AXIS OF CONVECTION NEAR THE I-55 CORRIDOR LATER THIS EVENING
COULD BE THE FOCUS FOR MORE REDEVELOPMENT LATER TONIGHT AS GULF
MOISTURE ADVECTION INCREASES SOMEWHAT (IN TANDEM WITH INVIGORATING
LOW LEVEL JET). SUCH A SCENARIO COULD POTENTIALLY BRING HEAVY RAIN
WORRIES LATER TONIGHT INTO EARLY TOMORROW INTO PLAY A LITTLE FURTHER
EAST THAN WE WERE PREVIOUSLY ANTICIPATING...BUT FOR NOW WE WILL
CONTINUE TO KEEP THE MAIN LIMITED RISK OF HEAVY RAIN ISSUES LATE
TONIGHT INTO TOMORROW CONFINED TO WESTERN ZONES. THIS LATTER AREA
SHOULD THEORETICALLY EXPERIENCE THE BEST LIFT AND MOISTURE ADVECTION
THROUGH THIS TIME IF MESOSCALE INFLUENCES FROM INCOMING WEAK MCS
DOES NOT OVERLY BIAS THE SYNOPTIC SETUP.
ONCE AGAIN...THE RISK OF SEVERE STORMS THROUGH TONIGHT AND EARLY
TOMORROW LOOKS TOO LOW TO MENTION IN THE HWO OR GRAPHICS...BUT THERE
MAY BE A WINDOW TOMORROW AFTERNOON FOR IMPRESSIVE CAPE (MLCAPE NEAR
2000 J/KG) TO BUILD AS THE FRONT ITSELF PUSHES CLOSER TO THE REGION.
AGAIN...SHEAR SHOULD REMAIN VERY MARGINAL FOR MUCH ORGANIZATION TO
STORMS...BUT THE EVEN MARGINAL INSTABILITY MAY PUSH AN ISOLATED
STORM OR TWO TO SEVERE LIMITS IF CAPE VALUES REALLY MANAGE TO PEAK
UP TO (OR ABOVE) THE PREVIOUSLY MENTIONED LEVEL. STILL DO NOT HAVE
QUITE ENOUGH CONFIDENCE TO ISSUE AN OFFICIAL LIMITED RISK FOR SEVERE
STORMS IN THE HWO/GRAPHICS...BECAUSE IT IS MORE LIKELY MOST STORMS
WILL NOT DO MORE THAN PRODUCE BRIEF GUSTY WINDS...SMALL
HAIL...FREQUENT LIGHTNING...AND HEAVY DOWNPOURS. OF COURSE WE WILL
MONITOR CLOSELY FOR ANY NEEDED ADJUSTMENTS TO THIS THINKING.
THE MEAT OF THE UPPER DISTURBANCE DRIVING MOVEMENT OF THE INCOMING
FRONT WILL START TRANSITIONING TO OUR EAST THURSDAY NIGHT...BUT THE
FRONT REALLY LOOKS TO DRAGS ITSELF INTO THE REGION VERY SLOWLY AS
THE IMPETUS FOR MOVEMENT ALOFT IS REALLY FOCUSED WELL TO OUR NORTH.
IT IS POSSIBLE THE TAIL END OF THIS FRONT COULD CONTINUE TO KICK UP
A FEW SHOWERS OR STORMS THROUGH FRIDAY (ESPECIALLY ACROSS CENTRAL
AND EASTERN MS) DESPITE LIFT ALOFT REALLY WEAKENING QUICKLY.
BUT THE FRONT SHOULD GET OUT OF THE WAY BY THE WEEKEND...LEAVING
DECENT AND WARM CONDITIONS AT THE RIGHT TIME. A WEAK DISTURBANCE
SLIDING INTO THE LOWER MS VALLEY ON MONDAY MAY KICK UP A FEW MORE
SHOWERS...AND MAYBE A STORM...SUNDAY NIGHT INTO MONDAY BUT BY THIS
TIME THE BULK OF ENERGY SHOULD START TO SHIFT NORTH AND NORTHWEST OF
OUR AREA. THIS ENERGY INFLUX INTO THE PLAINS AND MID MS VALLEY NEXT
WEEK COULD SPELL SOME STORMY TIMES FOR THEM AND WE WILL HAVE TO
WATCH ANOTHER ROUND OR TWO OF MODEL RUNS TO FIGURE OUT IF THIS
STORMINESS MIGHT NOT SAG INTO AT LEAST NORTHERN PORTIONS OF THE
FORECAST AREA FOR A FEW DAYS NEXT WORK WEEK. OTHERWISE...EXPECT A
TREND TOWARD TYPICAL LATE SPRING WARMTH. /BB/
&&
.AVIATION...SHOWERS AND THUNDERSTORMS ARE MOVING EAST INTO AREA
AND WERE EXPECTED TO IMPACT GLH AROUND 21Z. MUCH OF THE ACTIVITY WAS
EXPECTED TO REMAIN WEST UNTIL LATE THIS AFTERNOON...SO GWO/GLH/HKS
AND JAN WOULD BE IMPACTED BETWEEN 23 AND 4Z. WHILE IT WAS MOSTLY
RAIN...THUNDERSTORMS WERE BRIEFLY REDUCING VISIBILITIES TO A MILE OR
LESS AND CEILINGS WERE BEING LOWERED. ADDED A TEMPO GROUP FOR +TSRA
FOR JAN THIS EVENING...NOT TOTALLY SOLD THAT THUNDERSTORMS WILL
EXPAND THAT FAR EAST. MODELS SUGGEST A FEW STORMS MAY APPROACH HBG
THIS EVENING...BUT LEFT TS OR VCTS OUT AT THIS POINT. STILL
EXPECTING FOG TO DEVELOP AGAIN TONIGHT FOR HBG...SO KEPT MVFR AND
ADDED A TEMPO FOR LIFR CONDITIONS. FOG HUNG ON FOR A WHILE THIS
MORNING AND CONDITIONS WILL NOT BE MUCH DIFFERENT IN THE MORNING.
IMPACTS GTR/MEI SEEM TO BE MINIMAL AT THIS TIME./7/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 62 79 61 78 / 64 74 61 30
MERIDIAN 56 78 61 77 / 20 60 68 45
VICKSBURG 62 80 60 80 / 66 64 51 22
HATTIESBURG 60 79 62 78 / 19 51 60 43
NATCHEZ 63 79 61 80 / 69 62 48 26
GREENVILLE 62 78 60 79 / 58 62 50 16
GREENWOOD 63 79 59 78 / 81 65 61 23
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
BB/7/19
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
618 PM CDT THU APR 21 2016
.SYNOPSIS...
ISSUED AT 333 PM CDT THU APR 21 2016
H5 ANALYSIS FROM EARLIER THIS MORNING HAD A CLOSED LOW
OVER WESTERN IOWA WITH A TROUGH OF LOW PRESSURE EXTENDING SOUTH INTO
THE ARKLATEX. HT FALLS OF 50 TO 70 METERS WERE NOTED FROM THE MID
MISSISSIPPI VALLEY NORTHWARD TO THE ARROWHEAD OF MINNESOTA. WEST OF
THE TROUGH AND CLOSED LOW...WAS A RIDGE OF HIGH PRESSURE WHICH
EXTENDED FROM THE FOUR CORNERS...NORTH TO NORTHERN MONTANA. WEST OF
THE RIDGE...A TROUGH OF LOW PRESSURE WAS PRESENT FROM THE
ALEUTIANS...SOUTH INTO THE EASTERN PACIFIC...AND WAS ROUGHLY 500
MILES WEST OF THE OREGON AND WASHINGTON COASTS. AT THE SURFACE...LOW
PRESSURE WAS LOCATED OVER CENTRAL IOWA WITH HIGH PRESSURE ANCHORED
ACROSS THE FRONT RANGE OF COLORADO AND WYOMING. ACROSS WESTERN AND
NORTH CENTRAL NEBRASKA...WINDS WERE NORTHERLY BETWEEN THESE TWO
SURFACE FEATURES...AND WERE BREEZY THIS AFTERNOON WITH SPEEDS OF 15
TO 25 MPH. UNDER PARTLY CLOUDY SKIES...TEMPERATURES WERE IN THE
UPPER 60S TO AROUND 70.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 333 PM CDT THU APR 21 2016
MAIN FORECAST CONCERNS ARE WIND AND TEMPERATURES. THE UPPER LOW
CONTINUES ITS SLOW EASTWARD TREK AND GETS ABSORBED WITH THE OVERALL
FLOW OVER THE GREAT LAKES. H5 RIDGE BUILDS OVER THE GREAT PLAINS
WHILE A SURFACE TROUGH APPROACHES THE PANHANDLE LATE FRIDAY.
THIS EVENING AND TONIGHT... EFFICIENT MIXING TO NEAR 750HPA AS
INDICATED BY RAP AND HRRR SOUNDINGS AND NEARLY UNIDIRECTIONAL FLOW
CREATING GUSTS TO 25MPH FOR MUCH OF THE AREA. SOUNDINGS ALSO
INDICATE LOW LEVEL LIFT... WHICH IS CONFIRMED BY A GROWING CUMULUS
FIELD OVER WESTERN NEBRASKA. LEFT PRECIP MENTION OUT AS ABUNDANT DRY
AIR EXISTS IN THE MID LEVELS AND SURFACE DEW POINT DEPRESSIONS REACH
30F WEST TO 20F EAST. CLOUDS WILL CLEAR TONIGHT WITH THE LOSS OF
DIURNAL HEATING AND WINDS RELAX WITH BOUNDARY LAYER DECOUPLING.
MADE LITTLE CHANGE TO MIN TEMPS AS MID/UPPER 30S SEEMED REASONABLE
GIVEN CLEAR SKIES... LIGHT WINDS... AND NEGLIGIBLE TEMP ADVECTION AT
H85.
FRIDAY... CONTINUED THE TREND OF FOLLOWING WARMER GUIDANCE OR GOING
SLIGHTLY ABOVE FOR MAX TEMPS. RETURN FLOW SWITCHES LOW LEVEL WINDS
TO SOUTHERLY... AND MODELS IN AGREEMENT WITH APPRECIABLE WAA. H85
TEMPS RANGE FROM NEAR 20C PANHANDLE TO 10C NORTH CENTRAL... ABOUT 5
TO 10C WARMER THAN THURSDAY. LOW LEVEL WINDS STRENGTHEN THROUGHOUT
THE DAY AS THE PRESSURE GRADIENT INCREASES AHEAD OF THE TROUGH. NAM
SHOWING AROUND 1MB/HR FALLS DURING THE AFTERNOON. COUPLED WITH
SUBSIDENCE AND MIXING TO NEAR 800HPA WHERE H85 WINDS APPROACH
30KTS... GUSTS MAY REACH 25 TO 30MPH AT THE SURFACE. DESPITE WARM
TEMPERATURES AND BREEZY WINDS... FIRE WEATHER DOES NOT APPEAR TO BE
A SIGNIFICANT ISSUE AT THIS TIME. NAM...GFS...AND EURO KEEP SFC DEW
POINTS IN THE 40S DURING THE AFTERNOON... AND MIXING RATIOS INCREASE
1-2G/KG SINCE THURSDAY. MINIMUM RH VALUES STAY ABOVE 25 PERCENT
PANHANDLE AND 30 PERCENT EAST.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 333 PM CDT THU APR 21 2016
MID RANGE...FRIDAY NIGHT THROUGH SUNDAY...A TROUGH OF
LOW PRESSURE ALOFT WILL COME ONSHORE ACROSS NRN CALIFORNIA/OREGON
LATE FRIDAY. THIS FEATURE WILL TRACK EAST INTO WYOMING OVER THE NEXT
24 HOURS...MAKING IT AS FAR EAST AS NWRN WYOMING BY 00Z SUNDAY.
DURING THIS PERIOD...A STRONG LEE SIDE SFC CYCLONE WILL DEVELOP OVER
EASTERN WYOMING AND NERN COLORADO. EAST OF THIS FEATURE...SRLY WINDS
WILL INCREASE FRIDAY AFTERNOON INTO FRIDAY NIGHT. SRLY FLOW WILL
PUSH LOW LEVEL MOISTURE NWD DURING THE NIGHT AND THIS COUPLED WITH
THE SRLY WINDS...WILL MAKE FOR MILD TEMPS FRIDAY NIGHT. FCST LOWS
WILL BE IN THE UPPER 40S TO AROUND 50...SOME 10 TO 15 DEGREES ABOVE
NORMAL. ON SATURDAY...STRONG LOW LEVEL WARM AIR ADVECTION WILL
CONTINUE WITH H85 TEMPS REACHING 25C IN THE WEST BY 00Z SUN. THE
LATEST GUIDANCE REFLECTED THESE WARMER TEMPS SHOWN IN THE GRAPHICAL
NAM AND GFS FCST MODELS FROM THIS MORNING...AND HAVE TRENDED UP
HIGHS FOR SAT AFTN. THIS RESULTED IN HIGHS IN THE LOWER 80S ACROSS
THE BOARD. WE EVEN MAY SEE SOME MIDDLE 80S IN THE NORTHWEST WHERE
DRIER AIR IS EXPECTED SAT AFTN. ON SATURDAY EVENING...A PACIFIC COLD
FRONT WILL APPROACH THE PANHANDLE SAT EVENING...AND A LEAD
DISTURBANCE WILL APPROACH SWRN NEBRASKA FROM NERN COLORADO.
THUNDERSTORM CHANCES WILL INCREASE DURING THE EVENING HOURS WITH THE
BEST CHANCES IN THE SOUTHWEST IN PROXIMITY TO THE UPPER LEVEL
WAVE...AND IN THE NORTHWESTERN CWA INVOF THE FRONT AND CLOSER
PROXIMITY TO THE H5 LOW. AS FOR THE THREAT FOR SEVERE STORMS...WAS
CONCERNED SOMEWHAT ABOUT THE 2000 J/KG CAPES DEPICTED IN THE 12Z
NAM SOLN THIS MORNING...ACROSS CENTRAL PORTIONS OF THE CWA.
HOWEVER...BULK SHEAR IS ONLY 15 TO 20 KTS SAT AFTN/EVE...SO THE
SEVERE THREAT APPEARS MINIMAL ATTM. ON SUNDAY...THE UPPER LEVEL LOW
WILL TRACK ALONG THE NEBR/SD BORDER. ATTM...THE MAIN THREAT FOR PCPN
WILL CONTINUE OVER NRN NEBRASKA WITH MAINLY DRY CONDS IN THE SOUTH.
IT WILL BE WINDY WITH DECENT NORTHWESTERLY WINDS BEHIND THE COLD
FRONT SUNDAY. TEMPERATURES WILL RANGE FROM AROUND 60 IN THE WEST TO
THE MID 70S IN THE FAR EAST.
LONG RANGE...SUNDAY NIGHT THROUGH THURSDAY...AN ACTIVE SWRLY FLOW
PATTERN WILL CONTINUE INTO NEXT WEEK. THE FIRST OF TWO UPPER LEVEL
LOWS WILL APPROACH THE FORECAST AREA MONDAY NIGHT WITH LIKELY PCPN
EXPECTED FOR TUESDAY INTO TUESDAY NIGHT. PCPN WILL LINGER IN THE
NORTH FOR WEDNESDAY...WITH DRY CONDS EXPECTED WEDS NIGHT INTO
THURSDAY. A SECOND SYSTEM WILL APPROACH THE REGION LATE THURSDAY
WITH ANOTHER ROUND OF PCPN ON TAP FOR FRIDAY INTO SATURDAY NEXT
WEEK. TEMPERATURES WILL BE COOL WITH HIGHS IN THE 50S WITH SOME 40S
POSSIBLE IN NRN NEBRASKA TUES/WEDS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 618 PM CDT THU APR 21 2016
VFR IS EXPECTED ALL AREAS OVERNIGHT THROUGH FRIDAY AFTERNOON.
SFC LOW PRESSURE WILL ORGANIZE ACROSS THE NRN HIGH PLAINS BENEATH
AN UPPER LEVEL RIDGE OF HIGH PRESSURE. SKIES SHOULD REMAIN MOSTLY
CLEAR.
&&
.HYDROLOGY...
ISSUED AT 333 PM CDT THU APR 21 2016
RISES ON THE SOUTH PLATTE RIVER EXPECTED TO CONTINUE
OVER THE NEXT SEVERAL DAYS. UPSTREAM GAUGE AT JULESBURG STILL
SHOWING A SLOW RISE WITH AN EXPECTED CREST AT ROSCOE OF AROUND 7.3
FEET LATE FRIDAY/EARLY SATURDAY. ISSUED RVS THIS MORNING WITH
UPDATED FORECAST FROM MBRFC. SLIGHT UPTICK OBSERVED AT NORTH PLATTE
BUT STILL 1.5 FEET BELOW ACTION STAGE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BUTTLER
SHORT TERM...SNIVELY
LONG TERM...BUTTLER
AVIATION...CDC
HYDROLOGY...SNIVELY
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
408 PM CDT WED APR 20 2016
.SYNOPSIS...
ISSUED AT 405 PM CDT WED APR 20 2016
H5 ANALYSIS THIS MORNING HAD A CLOSED LOW OVER NORTH PLATTE WITH
RIDGING OFF TO THE WEST OVER THE INTERMOUNTAIN WEST INTO THE
PANHANDLE OF IDAHO. EAST OF THE LOW...A LOW AMPLITUDE RIDGE OF
HIGH PRESSURE EXTENDS FROM THE FLORIDA PANHANDLE NORTH TO THE
OHIO VALLEY. HT FALLS THIS MORNING WERE MOST PRONOUNCED ACROSS
EASTERN KANSAS AND EASTERN NEBRASKA...WITH 70 METER FALLS NOTED AT
OMAHA AND 100 METER FALLS NOTED AT TOPEKA. CURRENT SATELLITE
IMAGERY HAS THE LOW NEAR LEXINGTON NEBRASKA WITH A SECONDARY
CIRCULATION NOTED AROUND OMAHA. SHOWERS HAVE CONTINUED TO ROTATE
AROUND THE NORTHERN AND WESTERN PERIPHERY OF THE LOW TODAY AND
HAVE MADE IT AS FAR WEST AS A MERRIMAN TO OGALLALA LINE. OVER THE
PAST COUPLE OF HOURS...SOME CONVECTIVE SHOWERS HAVE DEVELOPED OVER
SERN LINCOLN AND FRONTIER COUNTIES. ELSEWHERE...A MORE PERSISTENT
SHIELD OF RAIN WAS OCCURRING ACROSS THE NEBRASKA SANDHILLS.
HOURLY RAINFALL RATES WERE LIGHT...AT OR UNDER 3 HUNDREDTHS OF AN
INCH. TEMPERATURES AS OF 3 PM CDT RANGED FROM 51 TO 59 DEGREES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 PM CDT WED APR 20 2016
THIS EVENING AND TONIGHT...EXPANDED HIGH CHC POPS WEST TO HWY 83
TO ACCOUNT FOR SCATTERED SHOWERS ROTATING AROUND THE LOW. ALSO
EXPANDED ISO THUNDER MENTION FOR SOUTHERN HALF OF THE FORECAST
AREA. FORECAST SOUNDINGS SHOW STEEP LOW LEVEL LAPSE RATES AND
PERIODS OF SIGNIFICANT LIFT. RAP ANALYSIS ALSO SHOWS MARGINAL
CAPE...GENERALLY 500 J/KG OR LESS...LIFTED INDEX AS LOW AS -1...
AND MID LEVEL LAPSE RATES NEAR 7C/KM. GIVEN DEEP COLD AIR
ALOFT...SMALL HAIL IS POSSIBLE WITH ANY STORM. HRRR AND RAP
INDICATE MOST OF THE SHOWER/STORM ACTIVITY OUTSIDE NORTH CENTRAL
NEBRASKA WILL BE DIURNALLY DRIVEN. SLOWLY PULL POPS FOR
BOYD...HOLT...WHEELER COUNTIES TONIGHT DUE TO THE PROXIMITY OF AN
AREA OF STEADY RAIN OVER NORTHEAST NEBRASKA. MADE LITTLE CHANGE TO
MIN TEMPS AS PREVIOUS FORECAST LOWS ARE SIMILAR TO 12Z MOS
GUIDANCE SUITE...COOLER PANHANDLE AND WEST FOR CLEARING SKY AND
LIGHT WINDS AND MILD NORTH CENTRAL FOR SUSTAINED CLOUDINESS.
DESPITE RECENT RAINFALL AND LIGHTENING WINDS OVERNIGHT...RISK OF
FOG IS LOW. SLIGHTLY DRIER AIR MOVES IN AS SHOWN BY FALLING MIXING
RATIOS...AND AS SURFACE WINDS TURN WESTERLY/NORTHWESTER...ITS NOT
AS FAVORABLE FOR FOG FORMATION.
THURSDAY...H5 LOW SCOOTS EAST INTO IOWA AND THE H3 JET MAX CENTERS
OVER THE MISSOURI RIVER. TRENDED MAX TEMPS TOWARD THE MAV...WHICH
RESULTED IN AN INCREASE OF A DEGREE OR SO AREAWIDE. NAM SOUNDINGS
INDICATE DRY AIR ALOFT...WEAK TO NON EXISTENT LIFT IN THE LOWER
LEVELS...AND A MIXED LAYER APPROACH 700HPA. MID LEVEL FGEN FORCING
ALSO WEAKENS AS THE LOW MOVES EAST OF THE AREA. WITH MAINLY FAIR
CONDITIONS AND UNINHIBITED MIXING...BREEZY NORTH WINDS ARE LIKELY
AND H85 TEMPS AROUND 10C SHOULD TRANSLATE TO HIGHS NEAR 70F.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 405 PM CDT WED APR 20 2016
MID RANGE...THURSDAY NIGHT THROUGH SATURDAY...IN THE MID RANGE...A
BENIGN WEATHER PATTERN IS EXPECTED IN THE MID RANGE WITH
TEMPERATURES BEING THE MAIN FORECASTING CHALLENGE. THE CLOSED LOW
WILL TRACK INTO THE OHIO VALLEY THURSDAY NIGHT INTO FRIDAY...WHILE
RIDGING ALOFT BUILDS EAST FROM THE CENTRAL ROCKIES INTO THE
CENTRAL PLAINS. TEMPERATURES FRIDAY WILL REACH THE LOWER TO MIDDLE
70S...FOLLOWED BY MID 70S TO AROUND 80 FOR SATURDAY. THE LATEST
NAM SOLN WAS BEGINNING TO INDICATE A FAVORABLE ENVIRONMENT FOR
THUNDERSTORMS SATURDAY AFTERNOON IN THE WEST WITH VERY FAVORABLE
SURFACE BASED INSTABILITY AND A DECENT AMOUNT OF SD CAPE.
HOWEVER...SHEAR LOOKS WEAK ATTM. THE GFS AND ECMWF SOLNS HOLD OFF
ON CONVECTION UNTIL SAT EVENING AND HAVE OPTED TO GO THIS ROUTE
AND LEAVE SAT AFTERNOON DRY FOR NOW. BETTER CHANCES FOR
PRECIPITATION WILL ARRIVE IN THE WEST SATURDAY EVENING AS A LEAD
SHORTWAVE CROSSES THE PANHANDLE.
LONG RANGE...SATURDAY NIGHT THROUGH WEDNESDAY...BEGINNING SATURDAY
NIGHT...CHANCES FOR PCPN WILL INCREASE IN THE WEST AS A LEAD
SHORTWAVE CROSSES THE PANHANDLE. THIS WILL BE FOLLOWED BY A CLOSED
LOW WHICH TRACKS ACROSS SRN SD SUNDAY INTO SUNDAY NIGHT. WRAP
AROUND PCPN FROM THE SYSTEM WILL IMPACT THE NORTHERN CWA ON
SUNDAY AND SUNDAY NIGHT. FURTHER SOUTH...COOLER AND WINDY CONDS
ARE EXPECTED SUNDAY...WITH NOT MUCH IN THE WAY OF PCPN EXPECTED.
BETTER CHANCES FOR PRECIPITATION WILL ARRIVE MONDAY NIGHT INTO
WEDNESDAY AS A SECOND UPPER LOW LEVEL LOW TRACKS FROM THE CENTRAL
ROCKIES ONTO THE CENTRAL PLAINS. TEMPERATURES WILL BE MUCH COOLER
AS WELL WITH HIGHS IN THE 50S BY MIDWEEK NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 405 PM CDT WED APR 20 2016
SCATTERED LIGHT RAIN SHOWERS WILL CONTINUE THIS AFTERNOON ACROSS
WESTERN AND NORTH CENTRAL NEBRASKA. AN ISOLATED THUNDERSTORM
CANNOT BE RULED OUT FOR SOUTHWEST NEBRASKA...INCLUDING KLBF...
KOGA...KBBW...AND KIML. RAIN SHOWER COVERAGE AND WIND SPEED WILL
DECREASE AROUND SUNSET WHILE LOW/MID LEVEL CLOUD COVER WILL THIN
OVERNIGHT.
&&
.HYDROLOGY...
ISSUED AT 405 PM CDT WED APR 20 2016
RISES EXPECTED TO CONTINUE ON THE SOUTH PLATTE RIVER FOR THE NEXT
SEVERAL DAYS DUE TO RECENT PRECIPITATION OVER WESTERN NEBRASKA
AND COLORADO. USGS STREAM GAUGE AT ATWOOD CO HAS SHOWN A LEVELING
OFF WHILE JULESBURG STILL SHOWS A STEADY RISE. IN COORDINATION
WITH THE MBRFC...A FORECAST SHOWS A CREST AROUND 7 FEET LATE
FRIDAY AT ROSCOE...WHICH PUTS IT AT ACTION STAGE. NO FLOODING IS
EXPECTED AT THIS TIME.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BUTTLER
SHORT TERM...SNIVELY
LONG TERM...BUTTLER
AVIATION...SNIVELY
HYDROLOGY...BUTTLER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1256 AM CDT WED APR 20 2016
.UPDATE...
ISSUED AT 1249 AM CDT WED APR 20 2016
BASED ON SURFACE OBSERVATIONS...WEB CAMS...AND SHORT TERM HI
RESOLUTION MODELS HAVE ISSUED A DENSE FOG ADVISORY FROM THE
EASTERN EDGE OF THE FORECAST AREA...TURTLE MOUNTAINS AND JAMES
RIVER VALLEY...TO THE MISSOURI RIVER BORDER COUNTIES. VISIBILITIES
WERE DOWN BELOW A QUARTER MILE IN THE TIOGA TO STANLEY AREAS AND
LESS THAN A MILE AT MINOT AND JAMESTOWN.
OTHERWISE...HAVE RAISED OVERNIGHT LOWS THROUGH THE JAMES RIVER
VALLEY A FEW DEGREES DUE TO DEW POINTS AND EXPECTED FOG AND LOW
STRATUS...WHICH SHOULD PREVENT MUCH OF A TEMPERATURE DROP
OVERNIGHT.
UPDATE ISSUED AT 929 PM CDT TUE APR 19 2016
LOWERED MINIMUM TEMPERATURES OVERNIGHT IN THE SOUTHWEST SLIGHTLY
AS QUITE A BIT OF CLEARING HAS OCCURRED THIS EVENING. MINOT AND
JAMESTOWN OBSERVATIONS HAVE NOTED SOME PATCHY FOG IN THE PAST HOUR
OR SO...THEREFORE DID INTRODUCE PATCHY FOG IN PARTS OF THE CENTRAL
AND EAST EARLIER THAN ORIGINALLY ANTICIPATED. OTHER THAN
THAT...THE FORECAST LOOKS TO BE ON TRACK.
UPDATE ISSUED AT 640 PM CDT TUE APR 19 2016
FORECAST LOOKS MAINLY ON TRACK SO NO MAJOR CHANGES WERE NEEDED FOR
THIS UPDATE. DID INCREASE PATCHY FOG TO AREAS OF FOG FROM 06Z TO
12Z OVERNIGHT EAST OF THE MISSOURI RIVER...REASONING BASED ON
RECENT MOISTURE...SOUTHERLY FLOW...AND FORECAST LIGHT SURFACE
WINDS. THE LAST SEVERAL ITERATIONS OF THE OPERATIONAL HRRR ALSO
SEEM TO SUGGEST THIS SOLUTION.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 331 PM CDT TUE APR 19 2016
FOCUS IS ON THE EXITING UPPER LEVEL LOW OVER THE ROCKIES AND FOG
WEDNESDAY MORNING.
THE SEMI STATIONARY UPPER LEVEL LOW PRESSURE OVER THE ROCKIES IS
BEGINNING TO PROPAGATE EAST...CUTTING OFF MOIST FLOW INTO THE
NORTHERN PLAINS. ONLY A FEW SHOWERS REMAIN ACROSS SOUTHEAST PARTS OF
NORTH DAKOTA AND WILL FURTHER DIMINISH THROUGH THE NIGHT.
DRIER AIR OVER CENTRAL SOUTH DAKOTA AND SOUTH CENTRAL NORTH DAKOTA
HAS USHERED IN SOME MOSTLY CLEAR SKIES. SHORT RANGE MODELS WERE
HAVING A HARD TIME PICKING UP ON THIS FEATURE...THUS LEANED MORE ON
LATEST SATELLITE FOR THE SHORT TERM SKY FORECAST.
SHORT RANGE MODELS STILL DEVELOP FOG ACROSS MUCH OF CENTRAL AND
WESTERN NORTH DAKOTA TONIGHT INTO WEDNESDAY MORNING. WITH THAT SAID
HAVE LEFT PATCHY FOG IN FOR ALL OF CENTRAL AND WESTERN NORTH DAKOTA
DUE TO LIGHT WINDS AND AMPLE MOISTURE FROM RECENT RAINS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 331 PM CDT TUE APR 19 2016
FOCUS IN THE LONG TERM IS ON THE CHANCES FOR PRECIPITATION SATURDAY
NIGHT INTO EARLY NEXT WEEK.
THE 12 UTC GUIDANCE CONTINUES TO SHOW AN UPPER LEVEL RIDGE BUILDING
INTO THE NORTHERN PLAINS THURSDAY...USHERING IN DRY CONDITIONS
THURSDAY THROUGH SATURDAY AFTERNOON.
LONGER RANGE MODELS HAVE COME INTO BETTER AGREEMENT ON THE NEXT
WEATHER MAKER FOR THE NORTHERN PLAINS. LIKE THIS PREVIOUS SYSTEM A
CUT OFF UPPER LEVEL LOW WILL SET UP OVER THE ROCKIES WITH MOIST FLOW
MOVING NORTH INTO NORTH DAKOTA. AT THIS TIME THE WEEKEND SYSTEM
APPEARS TO BE MORE PROGRESSIVE THAN THIS PAST WET WEATHER MAKER.
CHANCES RAIN AND EVEN POSSIBLY SNOW ON THE BACK SIDE START SATURDAY
NIGHT AND LAST INTO TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY)
ISSUED AT 1256 AM CDT WED APR 20 2016
LIFR/VLIFR CONDITIONS IN FOG AND STRATUS ARE EXPECTED AT
KISN/KMOT/KJMS THE REMAINDER OF TONIGHT THROUGH THE 14-16 UTC TIME
FRAME WEDNESDAY MORNING. FOG/STRATUS MAY ENCROACH UPON KBIS AFTER
09 UTC. KDIK IS EXPECTED TO REMAIN VFR FOR THE 06 UTC TAF CYCLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 11 AM CDT /10 AM MDT/ THIS MORNING FOR
NDZ001>005-009>013-017>023-025-034>037-045>048-050-051.
&&
$$
UPDATE...JPM
SHORT TERM...MM
LONG TERM...MM
AVIATION...ZH
AREA FORECAST DISCUSSION
NWS PORTLAND OR
857 PM PDT THU APR 21 2016
.SYNOPSIS...SHOWERS WILL CONTINUE TO SPREAD ACROSS THE REGION
TONIGHT AND ALSO BRING ISOLATED THUNDERSTORMS UNTIL SHORTLY AFTER
MIDNIGHT. SHOWERS WILL INTENSIFY LATER TONIGHT AND ALSO CONTINUE
THROUGH FRIDAY WITH ANOTHER ROUND OF THUNDERSTORMS POSSIBLE
FRIDAY AFTERNOON AND EVENING. THE UPPER LEVEL LOW CAUSING THESE
SHOWERS AND THUNDERSTORMS WILL MOVE EAST LATER FRIDAY NIGHT AND
EARLY SATURDAY...FOLLOWED BY ANOTHER LOW LATE SATURDAY INTO SUNDAY.
SNOW LEVELS WILL BE LOWERING BELOW THE CASCADE PASSES SUNDAY AND
MONDAY. THE UNSETTLED WEATHER WILL LIKELY LAST A GOOD PART OF NEXT
WEEK.
&&
.UPDATE...CONVECTION WAS VERY SLOW TO GET GOING THIS EVENING BUT
BEGAN IN EARNEST ABOUT 90 MINUTES AGO AS A WEAK VORT MAX BEGAN
CROSSING THE AREA. THIS WAS THE FINAL NECESSARY INGREDIENT TO
TRIGGER THE DEEPER CONVECTION UNDER A MARGINAL CONVECTIVE
ENVIRONMENT. EXPECT TO SEE THE SHOWERS AND STORMS CONTINUE PUSHING
NORTHWARD THIS EVENING AND REACH THE GREATER PORTLAND METRO AREA BY
11PM. ONLY ONE CELL ACROSS EASTERN LANE COUNTY HAS SHOWN MUCH
ORGANIZATION TO IT. MRMS ALGORITHMS (COMBINED FROM THE MEDFORD AND
PORTLAND RADARS) ARE INDICATING LESS THAN 1/2 INCH HAIL SIZE. BASED
ON LAST NIGHT`S EXPERIENCE WITH THESE RELATIVELY NEW
ALGORITHMS...FEEL REALITY IS BRINGING SLIGHTLY SMALLER STONES. MOST
IMPRESSIVE IS THE LONGEVITY THIS CELL HAS MAINTAINED. IT FIRST
STARTED DEVELOPING AROUND 02Z/7PM A LITTLE SOUTHEAST OF ROSEBURG AND
HAS MAINTAINED MODEST STRENGTH IN THE NEARLY 2 HRS SINCE THEN.
ONLY NOTABLE CHANGE TO THE FORECAST FOR TONIGHT WAS TO EXTEND THE
THUNDER THREAT INTO SOUTHWEST WASHINGTON THIS EVENING AND THEN
THROUGH ABOUT 2AM TONIGHT. MODELED THE AREA AND TIME LOOSELY ON THE
02Z HRRR RUN AND IT DID HAVE AN OK HANDLE ON THE CURRENT SITUATION.
UPDATES WILL BE AVAILABLE SHORTLY. PREVIOUS DISCUSSION FOLLOWS. /JBONK
&&
.AVIATION...A FRONT LIFTING NORTHEASTWARD ACROSS THE REGION
OVERNIGHT WILL LIKELY BRING A MIX OF MVFR AND VFR CONDITIONS ALONG
THE COAST AND MAINLY VFR CONDITIONS INLAND. A LINE OF SHOWERS AND
ISOLATED THUNDERSTORMS WILL MOVE NORTHWARD IN THE WILLAMETTE
VALLEY THROUGH APPROXIMATELY 09Z AND COULD IMPACT A TERMINAL OR
TWO...BUT CONFIDENCE ON SPECIFICALLY WHICH ONE REMAINS LOW.
OTHERWISE...EXPECT A SHOWERY DAY ON FRIDAY WITH ONLY BRIEF AND
OCCASIONAL MVFR CONDITIONS UNDER OR NEAR THE HEAVIEST SHOWERS.
KPDX AND APPROACHES...A FRONT LIFTING NORTHEASTWARD ACROSS THE
REGION WILL BRING RAIN SHOWERS AFTER 06Z FRIDAY...WITH PRIMARILY
VFR CONDITIONS EXPECTED THROUGH 06Z SATURDAY. THERE IS
APPROXIMATELY A 20 PERCENT CHANCE A THUNDERSTORM COULD IMPACT THE
TERMINAL BETWEEN 06Z AND 10Z FRIDAY. IN ADDITION...AN OCCASIONAL
AND BRIEF MVFR CIG OR VISIBILITY WILL BE POSSIBLE UNDER OR NEAR
THE HEAVIEST SHOWERS AT ANY POINT DURING THE NEXT 24 HOURS. WILL
HINT AT THIS POSSIBILITY WITH SCT GROUPS IN THE TAFS AS CONDITIONS
SHOULD REMAIN PREDOMINANTLY VFR. /NEUMAN
&&
.MARINE...A FRONT MOVING NORTHWARD ACROSS THE WATERS TONIGHT AND
FRIDAY WILL BRING A PERIOD OF GUSTY 25 TO 30 KT WINDS TO THE
WATERS. CONFIDENCE IS HIGHEST THESE WIND GUSTS WILL SURFACE ACROSS
THE OUTER WATERS SO CURRENT SMALL CRAFT ADVISORIES APPEAR ON
TRACK. HOWEVER...THERE IS A CHANCE THAT SOUTHWESTERLY WINDS BEHIND
THE FRONT ON FRIDAY COULD SPIKE INTO THE 25 KT RANGE ACROSS THE
INNER WATERS SO WILL LET THE MID SHIFT EVALUATE THIS THREAT FURTHER.
OTHERWISE...A COUPLE WEAK STORM SYSTEMS MOVING ACROSS THE WATERS
OVER THE WEEKEND WILL LIKELY HAVE FEW WIND IMPACTS. IT SHOULD BE
NOTED A WESTERLY SWELL WILL LIKELY RESULT IN SEAS TOPPING OUT
AROUND 10 FT. A NORTHERLY WIND PATTERN LATE IN THE WEEKEND AND
EARLY NEXT WEEK COULD PRODUCE SOME GUSTY 25 KT WINDS...BUT EXACTLY
HOW WIDESPREAD AND FOR HOW LONG REMAINS SOMEWHAT UNCERTAIN. AN
ADDITIONAL SWELL AROUND 10 FT LOOKS TO ENTER THE WATERS DURING
THIS TIME AS WELL. OTHERWISE...WINDS AND SEAS LOOK TO RELAX EARLY
TO MID NEXT WEEK. /NEUMAN
&&
.PREV DISCUSSION... /ISSUED 253 PM PDT THU APR 21 2016/
SHORT TERM...THE DRY PERIOD WILL BE COMING TO AN END THIS EVENING AS
AN UPPER LOW OFFSHORE CENTERED NEAR 142W 44N SWINGS A SHORTWAVE
TROUGH ACROSS THE AREA TONIGHT. THE MAIN PART OF THE SHORTWAVE IS
OFF THE NORTHERN CALIFORNIA AND SOUTH OREGON COAST. INSTABILITY IS
APPARENT WITH CUMULUS BUILD-UPS ALONG THE ENTIRE COAST RANGE ZONES
WHERE HIGHER CLOUDS ARE ABSENT. INSTABILITY IS MORE SUPPRESSED OVER
THE VALLEY AND CASCADES AS THICKER HIGH CLOUDS HAVE DELAYED CUMULUS
BUILD-UPS. MODELS ARE STILL ON TRACK FOR SOME SHOWERS TO DEVELOP
OVER THE HIGHER TERRAIN LATE TODAY THEN EXPAND DRAMATICALLY THIS
EVENING NEAR THE COAST RANGE AND SPREAD OUT INTO THE VALLEYS AND THE
CASCADES. THIS PRECIPITATION LOOKS CONVECTIVE AND WILL PROBABLY BE
LOCALLY HEAVY AS MODEL AND SATELLITE PRECIPITABLE WATER VALUES ARE
NEAR 1 INCH WHICH IS NEAR THE SEASONAL HIGH. MODEL LIFTED INDICES
ARE LOW ENOUGH TO INCLUDE A SLIGHT CHANCE OF THUNDER AGAIN MAINLY
THIS EVENING. SOUNDING PROFILES FOR THIS AFTERNOON AND EVENING SHOW
LESS CAPE THAN WED. YESTERDAY AFTERNOON KSLE SOUNDING SHOWED ABOUT
1000 J/KG WHILE THE CAPE FORECAST FOR THIS AFTERNOON AND EARLY
EVENING IS AROUND 100 J/KG PER NAM SOUNDING. SHOWERS CONTINUE FRIDAY
AS THE UPPER LOW MOVES THROUGH...AND WILL KEEP A CHANCE OF THUNDER
THEN AS WELL. THE MODELS SUGGEST THAT A DEFORMATION BAND MAY FORM
OVER SOUTHWEST WASHINGTON AND FAR NORTHWEST OREGON FRIDAY...SO THE
BEST CHANCE OF THUNDER WILL BE TO THE SOUTH. THE LOW DEPARTS BY
SATURDAY...BUT ANOTHER SYSTEM APPROACHES LATE SATURDAY THAT WILL
BRING MORE SHOWERS TO THE AREA INTO EARLY NEXT WEEK...AND DROP
CASCADE SNOW LEVELS BELOW THE PASSES SUNDAY AND MONDAY.
A RETURN TO MORE TYPICAL APRIL WEATHER FRIDAY AND THROUGH THE WEEKEND
WITH TEMPS INTO THE LOWER 60S AND OF COURSE SHOWERS FOR MAY FLOWERS.
/MH
LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. ACTIVE PATTERN CONTINUES
INTO NEXT WEEK...WITH ZONAL FLOW OVER THE PACIFIC BRINGING IN SYSTEM
AFTER SYSTEM. SHOWERS WILL BE TAPERING DOWN ON MONDAY AS SHORTWAVE
RIDGING BUILDS OVER THE PACIFIC NORTHWEST DRYING US OUT FOR TUESDAY.
MODELS STILL DIVERGE SOME ON WEDNESDAY WITH THE FOLLOWING SYSTEM
WILL BRING US ANY RAIN OR NOT. NEWER RUNS LEAN MORE TOWARDS THE
TRACK OF THIS SYSTEM GOING JUST SOUTH OF US. IF THIS IS TRUE...WE
MAY GET CLIPPED BY A LITTLE BIT OF RAIN ON WEDNESDAY IN THE OREGON
PART OF OUR AREA...BUT WASHINGTON WOULD STAY DRY. THURSDAY THEN
LOOKS DRY AS RIDGING BUILDS BACK OVER THE EASTERN PACIFIC. WHETHER
THIS BECOMES A STATIONARY RIDGE KEEPING US DRY INTO THE WEEKEND...OR
WHETHER IT IS MORE TRANSITORY WITH MORE SYSTEMS TO FOLLOW IS UP IN
THE AIR AT THIS TIME. -MCCOY
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 8 AM TO 4 PM PDT FRIDAY FOR
WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR FROM 10
TO 60 NM.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM PDT FRIDAY FOR
WATERS FROM CASCADE HEAD TO FLORENCE OR FROM 10 TO 60 NM.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS PENDLETON OR
804 PM PDT THU APR 21 2016
.UPDATE...A TROUGH CONTINUES TO APPROACH THE COAST THIS EVENING AS
THE RIDGE THAT HAS BEEN OVER THE AREA MOVES EAST. A WAVE EMBEDDED IN
THE SOUTHERLY FLOW OVER WASHINGTON AND OREGON HAS BEEN GENERATING
SHOWERS AND A THUNDERSTORM OR TWO WEST OF THE CASCADES. MODELS SHOW
THE DISTURBANCE MOVING INTO OUR AREA OVERNIGHT. THE NAM AND THE
SHORT TERM HRRR AND RUC13 MODELS ALL SHOW SHOWERS DEVELOPING LATER
TONIGHT OVER THE EASTERN MOUNTAINS AND PROPAGATING NORTH THROUGH THE
COLUMBIA BASIN BEFORE EXITING AROUND SUNRISE. RADAR IS ALREADY
SHOWING SOME ECHOES IN NORTHERN MALHEUR AND BAKER COUNTIES AND SEE
CELLS DEVELOPING IN NORTHERN NEVADA SO HAVE ADDED ISOLATED RAIN
SHOWERS FROM JOHN DAY EASTWARD IN THE MOUNTAINS AND FROM HANFORD
EASTWARD IN THE COLUMBIA BASIN. HAVE KEPT THE ISOLATED SHOWERS ALONG
THE CASCADES AND INTO CENTRAL OREGON NORTH TO YAKIMA AND ELLENSBURG.
HAVE ALSO RAISED CLOUD COVER TO MOSTLY CLOUDY FOR THE REST OF THE
NIGHT. MADE A FEW SMALL ADJUSTMENTS TO THE WIND AS WELL. REST OF THE
FORECAST LOOKED GOOD. FORECAST UPDATES ALREADY OUT. PERRY
&&
.SHORT TERM...TONIGHT THROUGH SUNDAY...THE HIGH PRESSURE RIDGE AXIS
IS SHIFTING EASTWARD AS A TROUGH OF LOW PRESSURE IN THE GULF OF
ALASKA SLIDES TOWARD THE PACIFIC NORTHWEST. THE TROUGH WILL FORM A
CLOSED LOW OFF THE SOUTHWEST COAST OF OREGON BY FRIDAY AFTERNOON.
THE ATMOSPHERE OVER EASTERN OREGON AND WASHINGTON WILL BEGIN TO
DESTABILIZE FRIDAY AS THE LOW APPROACHES LEADING TO AN INCREASE IN
SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA. THE LOW WILL
THEN MOVE OVER THE REGION FRIDAY NIGHT AND EXIT EARLY SATURDAY WITH
SHOWERS DECREASING OVERNIGHT. MODELS ARE HINTING THAT SOME MOISTURE
WRAPPING BACK AROUND THE LOW COULD IMPACT FAR NORTHEAST OREGON AND
SOUTHEAST WASHINGTON THROUGH SATURDAY MORNING SO HAVE BUMPED UP POPS
FOR THIS. OTHERWISE SATURDAY WILL BE AN IN BETWEEN WEATHER SYSTEMS
DAY BEFORE THE NEXT UPPER LEVEL LOW DROPS INTO THE PACIFIC NORTHWEST
LATE SUNDAY. THIS WILL ONCE AGAIN INCREASE SHOWERS AND BRING A
POSSIBILITY SOME THUNDERSTORMS TO PORTIONS OF THE FORECAST AREA.
THERE WILL ALSO BE SOME INCREASING WESTERLY WINDS FRIDAY AND THROUGH
THE WEEKEND USHERING IN SOME COOLER AIR. SNOW LEVELS WILL BE
DROPPING TO 5000 TO 6000 FEET ON FRIDAY NIGHT AND THEN DOWN TO 4000
TO 5000 FEET ON SUNDAY.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...A LARGE UPPER LOW WILL
BE MOVING SOUTHEAST ACROSS OREGON ON SUNDAY NIGHT. THIS WILL BRING A
GOOD CHANCE OF SHOWERS AND HIGH MOUNTAIN SNOW SHOWERS TO THE AREA.
ON MONDAY THE LOW WILL BE OVER THE GREAT BASIN BUT WRAP AROUND
MOISTURE ESPECIALLY IN OREGON WILL BRING A CONTINUED CHANCE FOR
SHOWERS AND MOUNTAIN SNOW SHOWERS ABOVE 4000-4500 FEET. WITH THE LOW
OVER THE CENTRAL ROCKIES ON TUESDAY AND SLIGHT RIDGING OVER THE AREA
EXPECT A DECREASE IN SHOWER ACTIVITY. BY WEDNESDAY ANOTHER UPPER LOW
WILL EITHER MOVE OVER OR JUST SOUTH OF THE REGION WITH INCREASING
CHANCES FOR SHOWERS. BY THURSDAY SHOWERS WILL BEGIN TO TAPER OFF.
THERE MAY BE ENOUGH INSTABILITY FOR THUNDERSTORMS WEDNESDAY AND
THURSDAY BUT THE MARGINAL NATURE OF THE THREAT SEVERAL DAYS OUT
PRECLUDES A MENTION IN THE FORECAST AT THIS TIME. IT WILL BE WINDY
THROUGH THE COLUMBIA RIVER GORGE AND KITTITAS VALLEY SUNDAY NIGHT
THROUGH MONDAY. TEMPERATURES WILL START OUT NEAR OR SLIGHTLY BELOW
NORMAL AND THEN RISE TO SLIGHTLY ABOVE NORMAL BY THE END OF THE
FORECAST PERIOD. 78
&&
.AVIATION...00Z TAFS...VFR CONDITIONS WILL PREVAIL THROUGH THE
FORECAST PERIOD. EXTENSIVE HIGH CLOUDS WILL GRADUALLY LOWER AND
THICKEN OVERNIGHT. LOWER CU/SC WILL DEVELOP FRIDAY MORNING AROUND
5000 FEET AGL. SCATTERED SHOWERS WILL DEVELOP ACROSS CENTRAL OREGON
FRIDAY MORNING AND OVER THE REST OF THE REGION BY FRIDAY AFTERNOON.
THERE COULD BE ISOLATED THUNDERSTORMS BUT EXPECTED LIMITED COVERAGE
PRECLUDES A MENTION IN THE TAFS AT THIS TIME. MOSTLY SW-W WINDS AT 5
TO 15 KT COULD BECOME TERRAIN DRIVEN OVERNIGHT BEFORE BECOMING
MOSTLY SW-W TOMORROW AT 10 TO 20 KT. 78
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 52 74 50 65 / 10 40 40 10
ALW 56 76 50 66 / 10 40 40 20
PSC 59 76 51 72 / 10 20 20 10
YKM 52 74 47 71 / 20 30 20 10
HRI 53 76 51 68 / 10 20 20 10
ELN 51 73 49 65 / 20 40 20 10
RDM 41 62 37 60 / 10 60 40 10
LGD 46 70 44 58 / 20 60 60 30
GCD 47 67 44 58 / 10 70 60 10
DLS 52 69 50 65 / 20 40 20 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
83/78/78
AREA FORECAST DISCUSSION
NWS PORTLAND OR
934 PM PDT TUE APR 19 2016
.SYNOPSIS...AN UPPER LEVEL TROUGH WILL APPROACH FROM THE SOUTHWEST
TONIGHT...BRINGING LOW CLOUDS AND PATCHY DENSE FOG TO THE COAST
TONIGHT...AND SHOWERS WITH COOLER TEMPERATURES WEDNESDAY.
THUNDERSTORMS AND SMALL HAIL ARE POSSIBLE WEDNESDAY AFTERNOON AND
EVENING. ANOTHER UPPER LEVEL LOW WILL CONTINUE THE COOLING TREND
THURSDAY AND FRIDAY WITH MORE SHOWERS. SEASONAL TEMPERATURES EXPECTED
THIS WEEKEND AS ANOTHER TROUGH IMPACTS THE PACIFIC NORTHWEST.
&&
.UPDATE...THE BIGGEST CHANGES MADE WITH THE EVENING UPDATE WAS THE
ADDITION OF PATCHY DENSE FOG ALONG THE COAST TONIGHT AND
THUNDERSTORMS WITH SMALL HAIL WEDNESDAY AFTERNOON/EVENING. BASED ON
RECENT HRRR RUNS FORECAST VISIBILITIES COMBINED WITH USCG
OBSERVATIONS LEAD TO THE ADDITION OF PATCHY DENSE FOG ALONG THE COAST
TONIGHT. FOR WEDNESDAY...MODEL SOUNDINGS CONTINUE TO SHOW DECENT HAIL
PARAMETERS ACROSS THE FORECAST AREA...WITH SBCAPE APPROACHING 1000
J/KG AND 0-5 KM BULK SHEAR AROUND 30 TO 35 KT IN THE INTERIOR VALLEY.
HOWEVER...00Z NAM SOUNDINGS INDICATE CONVECTIVE TEMPS IN THE MID TO
UPPER 80S WHICH WILL HELP LIMIT SURFACE BASED CONVECTION AND HAIL
SIZE. NONETHELESS...ELEVATED CONVECTION REMAINS A CONCERN WITH SMALL
HAIL POSSIBLE UNDER ANY THUNDERSTORMS THAT DO DEVELOP.
OTHERWISE...THE CURRENT FORECAST LOOKS ON TRACK SO NO OTHER CHANGES
WERE MADE. /64
&&
.AVIATION...STRATUS AND AREAS OF DENSE FOG HAVE DEVELOPED ALONG
THE COAST...RESULTING IN LIFR CONDITIONS. EXPECT FOG OR LOW
STRATUS TO REMAIN ALONG THE COAST THROUGH WED MORNING. INLAND
AREAS WILL LIKELY REMAIN VFR TONIGHT WITH LIGHT WINDS. SYSTEM
APPROACHING FROM THE S WILL BRING AN INCREASING CHANCE OF SHOWERS
AND THUNDERSTORMS WED...POSSIBLY AS EARLY AS WED MORNING S OF
KEUG-KONP. SHOWER/TSTM CHANCES SPREAD N THROUGH THE DAY WED...
WITH ABOUT A 40 PERCENT CHANCE OF TSRA DURING THE AFTERNOON.
DECIDED TO HANDLE THIS WITH VCTS IN MOST TERMINALS AFTER 21Z
WED FOR NOW...CAN FINE TUNE THE DETAILS WITH THE 12Z/18Z TAF
PACKAGES.
KPDX AND APPROACHES...VFR THROUGH TONIGHT UNDER VARIABLE HIGH
CLOUDS. INCREASING CHANCE OF SHOWERS WEDNESDAY WITH A CHANCE OF
THUNDERSTORMS WEDNESDAY AFTERNOON. WEAGLE/MCCOY
&&
.MARINE...MAIN ISSUE FOR THE COASTAL WATERS WILL BE AREAS OF DENSE
FOG TONIGHT...AS WEAK HIGH PRESSURE BUILDS ACROSS THE WATERS FOR
LIGHT AND VARIABLE WINDS AND SEAS GENERALLY AROUND 5 FT. WEAK COLD
FRONT LIFTS N-NE FROM THE NORCAL WATERS LATER TONIGHT AND WED...
BRINGING AN INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS. IF
THUNDERSTORMS DEVELOP...SOME COULD PRODUCE A DECENT AMOUNT OF
LIGHTNING AS WELL AS GUSTY AND ERRATIC WINDS ON THE WATERS.
OTHERWISE EXPECT A SLIGHT INCREASE IN S-SW WINDS...POSSIBLY
GUSTING TO 15-20 KT AT TIMES LATER WED/WED NIGHT. SLIGHTLY
STRONGER SOUTHERLIES SHOULD DEVELOP FRIDAY AS A SURFACE TROUGH AND
WEAK FRONT APPROACHES THE COAST. SEAS WILL INCREASE SOME LATER IN
THE WEEK. WEAGLE/SCHNEIDER
&&
.PREVIOUS DISCUSSION /ISSUED 252 PM PDT TUE APR 19 2016/...
SHORT TERM...TEMPERATURES ARE RAISING UNDER ABUNDANT SUNSHINE THIS
AFTERNOON. INLAND AREAS WILL WARM INTO THE 80S LATE THIS AFTERNOON.
CLOUDS HUGGING THE COAST WILL KEEP COASTAL AREAS FROM WARMING MUCH.
THE NORTH COAST MAY GET INTO THE 70S...BUT THE CENTRAL OREGON COAST
WILL LIKELY STAY IN THE 60S...OR EVEN UPPER 50S DOWN BY NEWPORT
WHERE THE CLOUDS HAVE MADE MORE OF A PRESENCE.
CONDITIONS BEGIN TO CHANGE TONIGHT AS AN UPPER LEVEL LOW CURRENTLY
OFFSHORE OF NORTHERN CALIFORNIA MOVES NE TOWARDS OREGON. THIS WILL
SPUR A SOUTHWEST MARINE PUSH THAT WILL REINFORCE LOW CLOUDS ALONG THE
COAST...AND SPREAD COOLER MARINE AIR INTO THE SOUTH AND POSSIBLY
CENTRAL WILLAMETTE VALLEY. THE APPROACHING TROUGH WILL DEEPEN THE
MARINE LAYER ALLOWING THE COASTAL CLOUDS ALONG THE COAST TO PUSH
INLAND ACROSS THE COASTAL AREAS AND INTO PARTS OF THE COAST RANGE
EARLY WEDNESDAY MORNING.
BESIDES THE LOW MARINE CLOUDS EXPECT MID AND HIGH LEVEL CLOUDS
ASSOCIATED WITH THE UPPER TROUGH TO STREAM MOVE OVER THE REGION. THE
HIGHER CLOUDS WILL MOVE SOUTH TO NORTH FROM WED MORNING THROUGH
WEDNESDAY AFTERNOON. THE CLOUDIER SKIES AND INFLUENCE OF THE MARINE
AIR WILL RESULT IN COOLER TEMPERATURES WEDNESDAY AFTERNOON...AROUND 8
TO 10 DEGREES COOLER THAN TODAY. ALTHOUGH IT WILL BE COOLER...THE
FORECASTED TEMPERATURES ARE STILL AROUND 15 DEGREES WARMER THAN THE
SEASONAL NORMALS.
THE UPPER LEVEL TROUGH WILL INCREASE MOISTURE AT THE MID LEVELS
PRIMING THE ATMOSPHERE FOR CONVECTION. THE AXIS OF THE
NEGATIVELY-TILTED UPPER TROUGH WILL SWING OVER NW OREGON IN THE
AFTERNOON DURING PEAK HEATING TIME. THIS WILL BE THE BEST CHANCE FOR
THUNDERSTORMS TO DEVELOP...AND THERE DOES LOOK TO BE A DECENT CHANCE.
DETERMINING THE LOCATION OF THUNDERSTORMS IS DIFFICULT...BUT THE
WARMER SURFACE TEMPERATURES NORTH OF SALEM MAKES ME THINK THE BEST
CHANCE FOR THUNDERSTORMS WILL BE THERE. HOWEVER...SOUNDINGS INDICATE
THE CONVECTION MAY BE ELEVATED...AND THESE TYPE OF THUNDERSTORMS HAVE
BEEN KNOWN TO SHOW UP IN AREAS WHERE THEY ARE LEAST EXPECTED.
A CHANCE FOR SHOWERS WILL INCREASE SOUTH TO NORTH WEDNESDAY
MORNING...AND LIKE THUNDERSTORMS...THE LOCATION AND TIMING OF THE
SHOWERS ARE DIFFICULT TO FORECAST. CAN GENERALLY EXPECT 0.05 TO 0.10
INCH OF RAIN WITH THE SHOWERS...EXCEPT AROUND 0.2 INCH OVER THE
CASCADES...AND WITH ANY THUNDERSTORMS THAT MAY DEVELOP. THE UPPER
TROUGH WILL MOVE TO THE NE WED NIGHT AND SHOWERS WILL EASE.
THE CHANCE FOR SHOWERS RETURNS THURSDAY AFTERNOON AS THE NEXT UPPER
LOW APPROACHES. THIS LOW IS APPROACHING FROM THE NW AND WILL BRING
ANOTHER NEGATIVELY UPPER TROUGH ACROSS THE PACIFIC NW THURSDAY AND
FRIDAY. TEMPERATURES WILL CONTINUE THE DOWNWARD TREND...BUT STILL
STAY ABOVE THE SEASONAL NORMALS. EXPECT SHOWERS THURSDAY AND FRIDAY
WITH AROUND 0.10 TO 0.20 INCH OF RAIN EACH DAY.
MOST OF THE CONVECTION WILL STAY NORTH AND EAST ON THURSDAY...BUT
THERE IS A POSSIBILITY FOR THUNDERSTORMS FRIDAY AFTERNOON AS THE
PARENT UPPER LOW MOVES INLAND ACROSS NORTHERN CALIFORNIA AND SOUTHERN
OREGON. FORECAST CONFIDENCE IS LOW FOR NOW ON THE THREAT FOR
THUNDERSTORMS...ESPECIALLY WITH THE EXPECTED CLOUD COVER AND COOLER
TEMPERATURES...BUT CAN NOT IGNORE THE MODELED CAPE OF 300-500
J/KG...AND HAVE ADDED A SLIGHT CHANCE OF THUNDERSTORMS FOR THE
CASCADES AND AREAS NORTH OF SALEM FRIDAY AFTERNOON. TJ
LONG TERM...FRIDAY NIGHT THROUGH TUESDAY. AFTER A SPELL OF SUMMER
WEATHER...APRIL RETURNS FOR THE WEEKEND WITH TEMPERATURES DROPPING
BACK DOWN AROUND OR EVEN BELOW NORMAL. NORTHWESTERLY FLOW ALOFT WILL
BRING BRING A SERIES OF SHORTWAVES INTO THE PACIFIC NORTHWEST OVER
THE WEEKEND. MODERATE ONSHORE FLOW WITH OROGRAPHIC LIFT ALONG THE
COAST RANGE AND CASCADES WILL KEEP SHOWERS IN THE AREA BETWEEN
SYSTEMS ON SATURDAY. THE NEXT SYSTEM WILL BRING MORE WIDESPREAD
SHOWERS ON SUNDAY. THE SUNDAY SYSTEM WILL BRING SNOW LEVELS DOWN
BELOW THE PASSES...WHICH MEANS A FEW INCHES OF SNOW COULD FALL AT
THE PASSES DURING THE DAY ON SUNDAY. SHORTWAVE RIDGING BUILDS JUST
OFF THE COAST...AND DEPENDING ON HOW FAR NORTH IT BUILDS THIS WILL
EITHER DRY US OUT OR REDUCE THE NUMBER OF SHOWERS ON MONDAY AND
TUESDAY. KEPT A SLIGHT CHANCE OF SHOWERS ON THESE DAYS DUE TO THIS
UNCERTAINTY. -MCCOY
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1002 PM EDT THU APR 21 2016
.SYNOPSIS...
LOW PRESSURE AND AN ACCOMPANYING FRONTAL SYSTEM WILL MOVE EAST
ACROSS THE MIDWEST AND OHIO VALLEY TOWARD THE REGION TODAY.
SHOWERS SPREADING INTO THE REGION THIS EVENING INTO FRIDAY WILL
BE FOLLOWED BY MILD AND DRY WEATHER THIS WEEKEND.
&&
.NEAR TERM /THROUGH FRIDAY/...
RADAR SHOWS VERY DISORGANIZED LIGHT SHOWERS TRACKING NORTHEAST
THROUGH THE NORTHERN MOUNTAINS AND LOWER SUSQUEHANNA VALLEY.
AIRMASS IS STILL VERY DRY SO RAIN IS HAVING A HARD TIME REACHING
THE GROUND.
LATEST HRRR SHOWS A GOOD CHANCE OF A LIGHT SHOWER IN MOST AREAS
BY MIDNIGHT...WITH MORE SHOWERS ARRIVING LATER AT NIGHT INTO EARLY
FRIDAY MORNING.
THE CLOUDS AND LIGHT SOUTH TO SWRLY LLVL FLOW WILL KEEP TEMPS MILD
OVERNIGHT...MAINLY IN THE MID TO UPPER 50S ACROSS CENTRAL AND SRN
PENN. SOME EVAP COOLING ACROSS THE NWRN ZONES WILL PUSH TEMPS A
LITTLE LOWER...DOWN INTO THE L50S.
&&
.SHORT TERM /FRIDAY NIGHT/...
SFC COLD FRONT WILL APPROACH FROM THE OHIO VALLEY FRIDAY. A PLUME
OF HIGH PWAT AIR /25-30MM/ WILL SLIDE EAST ACROSS THE STATE FRIDAY
AND EXIT THE SE ZONES AFTER 06Z SATURDAY.
FRIDAY LOOKS PRETTY CLOUDY AND SHOWERY WITH POPS IN THE 70-80
PERCENT RANGE. SOME SHORT TERM OPER MODEL GUIDANCE SUGGESTS THAT
MU CAPES WILL RAMP UP TO BETWEEN 500-1000 J/KG DURING THE DAY
FRIDAY...THOUGH THE ENSEMBLE MEAN IS SLIGHTLY LOWER AT A FEW TO
SVRL HUNDRED J/KG - JUST ENOUGH TO MENTION ISOLATED TSRA WHERE
SOME BREAKS IN THE CLOUD COVER DEVELOP.
SOME SHOWERS LINGER FRIDAY NIGHT...MAINLY IN THE S/SE AS THE
UPPER LOW AND REAL COLD AIR ALOFT TAKE UNTIL MIDNIGHT OR SO ON
FRIDAY NIGHT TO PASS COMPLETELY THROUGH.
24-36 HOUR QPF IS STILL SLATED TO HOLD TO ONLY 0.25 INCHES SE TO
PERHAPS AROUND 0.5 INCHES NW. EVEN ACROSS THE NW...THE GEFS AND
SREF PROB FOR 0.50 INCH OF RAIN OVER A 24 HOUR PERIOD IS BARELY
OVER 50 PERCENT. LATEST GEFS MINS FRI NIGHT WILL BE REALLY CLOSE
TO NORMAL ACROSS THE NORTH...AND JUST A HAIR ABOVE THEM IN THE
SOUTH.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
GUIDANCE HAS COME INTO MUCH BETTER AGREEMENT IN THE PATTERN
VERSUS PREVIOUS DAYS...SHOWING A MIGRATION FROM A BROAD
TROUGH/RIDGE/TROUGH CONFIGURATION EXTENDING FROM THE GREAT BASIN
TO THE PLAINS INTO THE MID ATLANTIC REGION AT THE START OF THE
PERIOD...TOWARD A MEAN WESTERN TROUGH/BUILDING RIDGE IN THE EAST
BY NEXT THU AS THE STRONG HIGH LATITUDE BLOCKING WEAKENS OVER
GREENLAND/EASTERN CANADA. UNCERTAINTY HAS ALSO DECREASED OVER THE
POSITION OF AN EAST/WEST SFC FRONTAL BOUNDARY AND LOW LEVEL
BAROCLINIC ZONE WITH COLDER TEMPERATURES STAYING WELL TO THE NORTH
OF PA ALONG THE NRN TIER STATES/CANADIAN BORDER.
THE NCEP MODELS ARE WEAKER AND MORE PROGRESSIVE VS. ECMWF/CMC
WITH THE SHORTWAVE TROUGH EXITING THE MID ATLANTIC EARLY SATURDAY.
THIS MAY LINGER CLOUDS/LIGHT RAIN OVER SOUTHERN AREAS DURING THE
MORNING BEFORE HIGH PRESSURE DRYS THINGS OUT BY THE AFTERNOON.
THE WEEKEND AS A WHOLE LOOKS FAIR AND DRY WITH A RISK OF
FROST/FREEZE CONDITIONS SATURDAY NIGHT INTO SUNDAY MORNING. WAVES
OF LOW PRESSURE MOVG EWD ALONG WAVY SFC FRONTAL BOUNDARY PRESSING
SWD FROM THE LOWER LAKES/UPSTATE NY SHOULD BRING PERIODS OF RAIN
EARLY NEXT WEEK BUT CONFIDENCE IN EXACT TIMING OF GREATEST PCPN
RISK IS STILL BELOW AVERAGE AND COULD EASILY SHIFT +/- 12 HOURS.
MODEL CONSENSUS FAVORS A DRY PERIOD ON WEDNESDAY BEFORE RAIN PROBS
TREND HIGHER FROM WEST TO EAST INTO THE SECOND HALF OF NEXT WEEK.
ASIDE FROM A CHILLY SUNDAY MORNING...THE GLOBAL ENSEMBLE MEANS
ALONG WITH NATIONAL/REGIONAL BLENDS ALL SUPPORT ABOVE NORMAL TEMPS
THROUGH THE MEDIUM RANGE PERIOD.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
DRY AIR IN THE LOW LLVLS SHOULD ENSURE VFR CONDS ACROSS THE
ENTIRE AREA THROUGH THE FIRST HALF OF THE OVERNIGHT PERIOD. A
BLEND OF LATEST NEAR TERM MDLS SUGGESTS A BRIEFLY HEAVIER SHOWERS
ARE POSSIBLE OVERNIGHT ACROSS THE NRN AND WRN MTNS WITH BRIEF
VISBY REDUCTIONS. THERE WAS A BRIEF TSTM OVER KDUJ BUT HAS SINCE
ENDED. THE BEST CHC FOR SHOWERS WILL ARRIVE FROM WEST TO EAST
DURING THE MID TO LATE MORNING HOURS FRIDAY...WITH ISOLATED TSRA
IMPACTS POSSIBLE BETWEEN 17-23Z FRIDAY.
OUTLOOK...
FRI...SHOWERS WITH AREAS OF MVFR CIGS AND BRIEF MVFR VSBYS
POSSIBLE /MAINLY ACROSS THE WRN MTNS/. ISOLATED TO SCT PM TSRA
IMPACTS POSSIBLE.
SAT...EARLY AM LOW CIGS POSSIBLE W MTNS.
SUN...NO SIG WX EXPECTED.
MON AND TUESDAY...PM SHRA DEVELOPING MONDAY AND CONTINUING INTO
TUESDAY. REDUCTIONS POSSIBLE...MAINLY NW PA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...STEINBUGL
AVIATION...LAMBERT/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
707 PM EDT THU APR 21 2016
.SYNOPSIS...
LOW PRESSURE AND AN ACCOMPANYING FRONTAL SYSTEM WILL MOVE EAST
ACROSS THE MIDWEST AND OHIO VALLEY TOWARD THE REGION TODAY.
SHOWERS SPREADING INTO THE REGION THIS EVENING INTO FRIDAY WILL
BE FOLLOWED BY MILD AND DRY WEATHER THIS WEEKEND.
&&
.NEAR TERM /THROUGH FRIDAY/...
RADAR SHOWS VERY DISORGANIZED LIGHT SHOWERS TRACKING NORTHEAST
THROUGH THE NORTHERN MOUNTAINS AND LOWER SUSQUEHANNA VALLEY.
AIRMASS IS STILL VERY DRY SO RAIN IS HAVING A HARD TIME REACHING
THE GROUND.
LATEST HRRR SHOWS A GOOD CHANCE OF A LIGHT SHOWER IN MOST AREAS
BY MIDNIGHT...WITH MORE SHOWERS ARRIVING LATER AT NIGHT INTO EARLY
FRIDAY MORNING.
THE CLOUDS AND LIGHT SOUTH TO SWRLY LLVL FLOW WILL KEEP TEMPS MILD
OVERNIGHT...MAINLY IN THE MID TO UPPER 50S ACROSS CENTRAL AND SRN
PENN. SOME EVAP COOLING ACROSS THE NWRN ZONES WILL PUSH TEMPS A
LITTLE LOWER...DOWN INTO THE L50S.
&&
.SHORT TERM /FRIDAY NIGHT/...
SFC COLD FRONT WILL APPROACH FROM THE OHIO VALLEY FRIDAY. A PLUME
OF HIGH PWAT AIR /25-30MM/ WILL SLIDE EAST ACROSS THE STATE FRIDAY
AND EXIT THE SE ZONES AFTER 06Z SATURDAY.
FRIDAY LOOKS PRETTY CLOUDY AND SHOWERY WITH POPS IN THE 70-80
PERCENT RANGE. SOME SHORT TERM OPER MODEL GUIDANCE SUGGESTS THAT
MU CAPES WILL RAMP UP TO BETWEEN 500-1000 J/KG DURING THE DAY
FRIDAY...THOUGH THE ENSEMBLE MEAN IS SLIGHTLY LOWER AT A FEW TO
SVRL HUNDRED J/KG - JUST ENOUGH TO MENTION ISOLATED TSRA WHERE
SOME BREAKS IN THE CLOUD COVER DEVELOP.
SOME SHOWERS LINGER FRIDAY NIGHT...MAINLY IN THE S/SE AS THE
UPPER LOW AND REAL COLD AIR ALOFT TAKE UNTIL MIDNIGHT OR SO ON
FRIDAY NIGHT TO PASS COMPLETELY THROUGH.
24-36 HOUR QPF IS STILL SLATED TO HOLD TO ONLY 0.25 INCHES SE TO
PERHAPS AROUND 0.5 INCHES NW. EVEN ACROSS THE NW...THE GEFS AND
SREF PROB FOR 0.50 INCH OF RAIN OVER A 24 HOUR PERIOD IS BARELY
OVER 50 PERCENT. LATEST GEFS MINS FRI NIGHT WILL BE REALLY CLOSE
TO NORMAL ACROSS THE NORTH...AND JUST A HAIR ABOVE THEM IN THE
SOUTH.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
GUIDANCE HAS COME INTO MUCH BETTER AGREEMENT IN THE PATTERN
VERSUS PREVIOUS DAYS...SHOWING A MIGRATION FROM A BROAD
TROUGH/RIDGE/TROUGH CONFIGURATION EXTENDING FROM THE GREAT BASIN
TO THE PLAINS INTO THE MID ATLANTIC REGION AT THE START OF THE
PERIOD...TOWARD A MEAN WESTERN TROUGH/BUILDING RIDGE IN THE EAST
BY NEXT THU AS THE STRONG HIGH LATITUDE BLOCKING WEAKENS OVER
GREENLAND/EASTERN CANADA. UNCERTAINTY HAS ALSO DECREASED OVER THE
POSITION OF AN EAST/WEST SFC FRONTAL BOUNDARY AND LOW LEVEL
BAROCLINIC ZONE WITH COLDER TEMPERATURES STAYING WELL TO THE NORTH
OF PA ALONG THE NRN TIER STATES/CANADIAN BORDER.
THE NCEP MODELS ARE WEAKER AND MORE PROGRESSIVE VS. ECMWF/CMC
WITH THE SHORTWAVE TROUGH EXITING THE MID ATLANTIC EARLY SATURDAY.
THIS MAY LINGER CLOUDS/LIGHT RAIN OVER SOUTHERN AREAS DURING THE
MORNING BEFORE HIGH PRESSURE DRYS THINGS OUT BY THE AFTERNOON.
THE WEEKEND AS A WHOLE LOOKS FAIR AND DRY WITH A RISK OF
FROST/FREEZE CONDITIONS SATURDAY NIGHT INTO SUNDAY MORNING. WAVES
OF LOW PRESSURE MOVG EWD ALONG WAVY SFC FRONTAL BOUNDARY PRESSING
SWD FROM THE LOWER LAKES/UPSTATE NY SHOULD BRING PERIODS OF RAIN
EARLY NEXT WEEK BUT CONFIDENCE IN EXACT TIMING OF GREATEST PCPN
RISK IS STILL BELOW AVERAGE AND COULD EASILY SHIFT +/- 12 HOURS.
MODEL CONSENSUS FAVORS A DRY PERIOD ON WEDNESDAY BEFORE RAIN PROBS
TREND HIGHER FROM WEST TO EAST INTO THE SECOND HALF OF NEXT WEEK.
ASIDE FROM A CHILLY SUNDAY MORNING...THE GLOBAL ENSEMBLE MEANS
ALONG WITH NATIONAL/REGIONAL BLENDS ALL SUPPORT ABOVE NORMAL TEMPS
THROUGH THE MEDIUM RANGE PERIOD.
&&
.AVIATION /23Z THURSDAY THROUGH TUESDAY/...
A WARM FRONT LIFTING NORTHEAST INTO THE AREA WILL SPREAD SCT
MAINLY VERY LIGHT SHOWERS INTO THE AREA /MAINLY NEAR AND TO THE
WEST OF A KJST TO KBFD LINE/ LATER TODAY AND TONIGHT.
DRY AIR IN THE LOW LLVLS SHOULD ENSURE VFR CONDS ACROSS THE
ENTIRE AREA THROUGH EARLY THIS EVENING. A BLEND OF LATEST NEAR
TERM MDLS SUGGESTS A BRIEFLY HEAVIER SHOWERS ARE POSSIBLE LATE
TODAY AND TONIGHT ACROSS THE NRN AND WRN MTNS WITH BRIEF VISBY
REDUCTIONS. THE BEST CHC FOR SHOWERS WILL ARRIVE FROM WEST TO EAST
DURING THE MID TO LATE MORNING HOURS FRIDAY...WITH ISOLATED TSRA
IMPACTS POSSIBLE BETWEEN 17-23Z FRIDAY.
OUTLOOK...
FRI...SHOWERS WITH AREAS OF MVFR CIGS AND BRIEF MVFR VSBYS
POSSIBLE /MAINLY ACROSS THE WRN MTNS/. ISOLATED TO SCT PM TSRA
IMPACTS POSSIBLE.
SAT...EARLY AM LOW CIGS POSSIBLE W MTNS.
SUN...NO SIG WX EXPECTED.
MON AND TUESDAY...PM SHRA DEVELOPING MONDAY AND CONTINUING INTO
TUESDAY. REDUCTIONS POSSIBLE...MAINLY NW PA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...STEINBUGL
AVIATION...LAMBERT
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1047 PM CDT THU APR 21 2016
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 418 PM CDT THU APR 21 2016
SECONDARY FRONTAL BOUNDARY PUSHING THROUGH THE I 90 CORRIDOR AT MID
AFTERNOON. HAS HEATED OUT WELL IN ADVANCE INTO THE MID AND UPPER 60S
AND IN LAST HOUR OR TWO...ISOLATED SHOWERS HAVE DEVELOPED IN THE I
29 CORRIDOR TO COMPLIMENT THE RESIDUAL DEFORMATION BAND SHOWERS
LINGERING ACROSS NORTHWEST IOWA. THESE SHOWERS...AND EVEN AN
ISOLATED RUMBLE OF THUNDER...WILL CONTINUE TO PUSH SOUTH THROUGH THE
LOSS OF DIURNAL SUPPORT EARLY THIS EVENING.
FOR THE REMAINDER OF THE SHORT TERM...WILL BE QUIET. SURFACE RIDGE
WILL NOSE INTO THE REGION TONIGHT...WINDS WILL DIMINISH HEADING
THROUGH THE EVENING HOURS. CLEARING WILL CONTINUE TO PROGRESS
THROUGH THE AREA...BUT INDICATIONS ARE THAT SOME LOWER LEVEL
MOISTURE WILL HANG UP NEAR THE EASTERN BORDER WITH PERHAPS SOME
LOWER CLOUDS ATTEMPTING TO BACK INTO PARTS OF SW MN AND NW IA LATER
IN THE NIGHT. A BIT TOO MUCH LINGERING GRADIENT REMAINS EAST OF I-
29 TO EXPECT TEMPERATURES TO BOTTOM OUT AT LOWEST POTENTIAL...BUT
WEST OF I-29 AND ESPECIALLY TOWARD THE MID JAMES VALLEY...LIKELY
COOLING TOWARD THE MID 30S COULD RESULT IN SOME PATCHY FROST.
SOUTHERLY WINDS WILL INCREASE ACROSS SOUTHEAST SOUTH DAKOTA ON
FRIDAY...BUT IN GENERAL WILL BE THE ONLY THING TO DIMINISH AN
OTHERWISE PLEASANT DAY. HIGHS WILL BE MILD...FROM LOWER 60S IN SW MN
AND NW IA...TO AROUND 70 IN SOUTH CENTRAL SD.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 418 PM CDT THU APR 21 2016
SATURDAY LOOKS LIKE A VERY WARM BUT WINDY DAY ACROSS THE REGION
AHEAD OF THE NEXT CUT OFF LOW MOVING INTO THE NORTHERN ROCKIES.
STRONG WARMING ALOFT...COPIOUS SUNSHINE AND MIXY SOUTHERLY SOUTHERLY
WINDS SHOULD ALLOW TEMPERATURES TO REACH WITHIN A FEW DEGREES ABOVE
OR BELOW 80. WIND SPEEDS WILL ALSO REACH NEAR ADVISORY LEVEL BY
AFTERNOON.
UPPER LOW SPINS INTO THE NORTHERN HIGH PLAINS ON SUNDAY...AND
WEAKENS AS IT MOVES EAST THROUGH THE REGION INTO MONDAY. MODELS ARE
IN DECENT AGREEMENT WITH THE TRACK OF THIS SYSTEM....WITH ONLY A FEW
SLIGHT DIFFERENCES. A WARM FRONT SETS UP ACROSS NORTHEAST SD SUNDAY
AFTERNOON...JUST NORTH OF THE FORECAST AREA. COULD SEE SOME ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORMS FORM IN THE WARM AIR
ADVECTION EAST OF I29 AND INTO THE HIGHWAY 14 CORRIDOR LATE SATURDAY
NIGHT INTO SUNDAY...HOWEVER MOISTURE IN THE LOW/MID LEVELS WILL BE
AN ISSUE. PRECIPITATION CHANCES INCREASE SUNDAY EVENING AND
OVERNIGHT AS THE LOW SHIFTS EASTWARD AND A COLD FRONT ARRIVES.
THE NEXT UPPER LEVEL CUT OFF LOW BARRELS INTO THE REGION MID
WEEK...AND WILL BRING YET ANOTHER ROUND OF WET WEATHER TO THE
NORTHERN PLAINS. MODELS ARE AGAIN IN DECENT AGREEMENT IN THE TIMING
AND TRACK OF THIS FEATURE...WHICH EMERGES IN THE HIGH PLAINS TUESDAY
EVENING AND SLOWLY WOBBLES EAST ACROSS THE REGION THROUGH AT LEAST
WEDNESDAY EVENING. THIS SYSTEM APPEARS TO BE A BIT COOLER AS
WELL...WHICH WILL KEEP HIGHS A LITTLE BELOW NORMAL. CLOUDS AND RAIN
SHOWERS WILL ACCOMPANY THIS SYSTEM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1041 PM CDT THU APR 21 2016
06Z TAFS ARE LIKELY GOING TO REFLECT VFR CONDITIONS WITH A COUPLE
OF CAVEATS. FIRST...STILL A LITTLE CONCERNED ABOUT PATCHY FOG
DEVELOPMENT IN THE JAMES RIVER VALLEY LATE TONIGHT AND EARLY
FRIDAY...RIGHT ALONG A SURFACE RIDGE AXIS WHICH WILL GIVE VERY
LIGHT WINDS IN THAT AREA. THEREFORE HEDGED WITH SOME MVFR TYPE FOG
FOR KHON...BUT AT THIS TIME DO NOT HAVE ENOUGH CONFIDENCE TO GO
ANY WORSE THEN THAT SINCE THE FOG MAY NOT FORM AT ALL. SECOND...
THERE ARE SOME INDICATIONS FROM THE LATEST NAM AND HRRR FIELDS
THAT THERE WILL BE ABUNDANT HUMIDITY IN THE VERY LOW LEVELS JUST
ABOVE THE SURFACE LATE TONIGHT THROUGH MID FRIDAY MORNING AT KSUX.
THE GROUND IS QUITE WET IN THAT AREA...SO IT MAY BE AN ARTIFACT OF
GROUND MOISTURE. BUT FOR A HEADS UP...DECIDED TO INCLUDE A
SCATTERED DECK AT 800 FEET JUST IN CASE SOME LOWER STRATUS FORMS
JUST BEFORE SUNRISE AND LINGERS INTO MID MORNING AT KSUX.
OTHERWISE CURRENTLY...UPPER END IFR TO MVFR STRATUS IS MOVING
SOUTHWARD ACROSS PARTS OF SOUTHWEST MN AND NORTHWEST IA. AT THIS
TIME...THE TRAJECTORY OF THESE CLOUDS SUGGEST THAT THEY WILL STAY
TOO FAR EAST TO IMPACT KSUX OR KFSD...BUT ESPECIALLY AT KSUX...IT
WILL BE CLOSE FOR A FEW HOURS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN
LONG TERM...
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
841 PM CDT THU APR 21 2016
.UPDATE...
FOR EVENING DISCUSSION.
&&
.DISCUSSION...
SHOWERS HAVE MOVED OFF TO THE EAST THIS EVENING...BUT PUT DOWN
AROUND A HALF INCH UP TO AN INCH ACROSS MOST OF THE MID STATE THIS
AFTERNOON. SHORT TERM MODELS ARE PUTTING ANOTHER BAND OF PRECIP
THROUGH THE AREA OVERNIGHT AS ANOTHER LOBE OF THE UPPER SHORTWAVE
MOVES THROUGH THE REGION. MUCAPE VALUES ARE LOW...BUT LEFT IN
MENTION OF SCHC THUNDER OVERNIGHT SINCE THERE MAY BE ENOUGH
INSTABILITY FOR SOME TSTORMS. TEMPS HAVE ALSO COOLED OFF QUITE A
BIT AS THE PRECIP ROLLED THROUGH...BUT LOOK TO LEVEL OFF FOR THE
REMAINDER OF THE NIGHT. OTHER THAN SOME OTHER MINOR TWEAKS...REST
OF FORECAST LOOKS ON TRACK.
&&
.AVIATION...
00Z TAF DISCUSSION.
VFR CONDITIONS GENERALLY EXPECTED THIS TAF PERIOD WITH BRIEF
PERIODS OF MVFR CIGS/VIS POSSIBLE. -SHRA HAVE MOVED EAST OF
CKV/BNA AND WILL END AT CSV BY 02Z. ANOTHER ROUND OF -SHRA
POSSIBLE AT ALL AIRPORTS OVERNIGHT PER HRRR MODEL. LIGHT SOUTH
WINDS TONIGHT WILL VEER TO WESTERLY ON FRIDAY.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION......BARNWELL
AVIATION........55/SHAMBURGER
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
810 PM CDT THU APR 21 2016
.UPDATE...
FOR 00Z AVIATION DISCUSSION.
&&
.DISCUSSION...
SHOWERS HAVE BECOME MORE WIDESPREAD OVER THE LAST COUPLE OF
HOURS. THIS TREND SHOULD CONTINUE INTO THIS EVENING WITH THE
AXIS OF HEAVIER PRECIP THAT HAS SPENT MOST OF THE DAY OVER OUR
NORTHWEST COUNTIES MOVING EAST THIS EVENING. WHILE MOST OF THE
SHOWERS HAVE BEEN FAIRLY LIGHT TO MODERATE, RADAR IS STILL
ESTIMATING ANYWHERE FROM 1 TO 1.8 INCHES OVER PORTIONS OF STEWART
AND WESTERN HOUSTON COUNTIES. AN ADDITION 0.25 INCHES OF RAINFALL
IS EXPECTED OVER THE REMAINDER OF THE AREA THIS EVENING AND INTO
TOMORROW...WITH SOME LOCALLY HIGHER AMOUNTS POSSIBLE. A FEW
RUMBLES OF THUNDER MAY MIX IN WITH THE SHOWERS, HOWEVER NOTHING
SEVERE IS EXPECTED. A FEW STORMS WILL CONTINUE TO BE POSSIBLE
HEADING INTO FRIDAY AS A WEAK COLD FRONT PUSHES THROUGH THE MID-
STATE. ALL PRECIP SHOULD FINALLY EXIT THE PLATEAU BY LATE FRIDAY
NIGHT.
WITH HIGH PRESSURE IN PLACE, THIS WEEKEND`S FORECAST LOOKS GREAT
WITH PLENTY OF SUNSHINE AND HIGH TEMPERATURES IN THE UPPER 70S AND
LOW 80S. A WEAK SHORTWAVE WILL BRING THE NEXT CHANCE OF SHOWERS
AND THUNDERSTORMS ON TUESDAY. WE COULD SEE SOME STRAGGLING
MOISTURE THROUGH WEDNESDAY FROM THAT SYSTEM. MOSTLY SCATTERED
PRECIP BOTH OF THOSE DAYS. MEANWHILE, A DEEPENING UPPER TROUGH
OVER THE CENTRAL U.S. WILL PUSH EASTWARD AND DRAW IN SOME DECENT
MOISTURE FROM THE GULF. THIS SYSTEM WILL GRADUALLY WEAKEN BUT WILL
PUSH A WEAK COLD FRONT AND ASSOCIATED SHOWERS AND THUNDERSTORMS
THROUGH THE TENNESSEE VALLEY THURSDAY INTO FRIDAY. TEMPERATURES
WILL BE NOTICEABLY WARMER NEXT WEEK WITH HIGHS REMAINING STEADY
IN THE LOW TO MID 80S. OVERNIGHT LOWS WILL REST IN THE LOW 60S.
&&
.AVIATION...
00Z TAF DISCUSSION.
VFR CONDITIONS GENERALLY EXPECTED THIS TAF PERIOD WITH BRIEF
PERIODS OF MVFR CIGS/VIS POSSIBLE. -SHRA HAVE MOVED EAST OF
CKV/BNA AND WILL END AT CSV BY 02Z. ANOTHER ROUND OF -SHRA
POSSIBLE AT ALL AIRPORTS OVERNIGHT PER HRRR MODEL. LIGHT SOUTH
WINDS TONIGHT WILL VEER TO WESTERLY ON FRIDAY.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM/AVIATION........55/SHAMBURGER
LONG TERM..................BARNWELL
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
311 PM CDT WED APR 20 2016
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...SATELLITE AND RADAR
IMAGES INDICATE CONVECTION CONTINUING TO DEVELOP ACROSS NORTHEAST
MEXICO THIS AFTERNOON AND BOTH THE NAM AND HRRR CONTINUE TO
INDICATE CONVECTION DEVELOPING ACROSS EXTREME WESTERN PORTIONS OF
THE CWA LATE THIS AFTERNOON INTO THIS EVENING. WITH THE SURFACE
INSTABILITY REMAINING HIGH ACROSS THE RIO GRANDE VALLEY AND
NORTHERN RANCHLANDS...CANNOT RULE OUT THE POTENTIAL FOR ISOLATED
SEVERE THUNDERSTORMS ACROSS PORTIONS OF ZAPATA...JIM HOGG...AND
STARR COUNTIES THIS EVENING. THE GREATEST THREAT FOR SEVERE
APPEARS TO BE HAIL AND DAMAGING WINDS. HEAVY RAINFALL CAN BE
EXPECTED WITH SOME OF THE STRONGER TO SEVERE STORMS. WILL GO WITH
THE HIGHEST POPS ACROSS THE WESTERN PORTIONS OF THE CWA WITH LOWER
POPS TOWARDS THE COAST THIS EVENING.
THE FORECAST FOR THURSDAY AND THURS NIGHT IS CHALLENGING WITH THE
WEST TO NORTHWEST FLOW ALOFT BUT THE NAM AND GFS HAVE A CONVECTIVE
BOUNDARY DEVELOPING ACROSS PORTIONS OF CENTRAL TX THURSDAY AND AS
THIS FEATURE MOVES SOUTHWARD IT WILL PROVIDE A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS ACROSS PORTIONS OF THE CWA THURSDAY INTO
THURS NIGHT AS MOISTURE POOLS ALONG AND AHEAD OF A WEAK COLD FRONT
MOVES SOUTHWARD ACROSS SOUTH TX.
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...UPPER LEVEL RIDGE WILL
BEGINS TO BUILD ACROSS THE DESERT SOUTHWEST INTO S TEXAS FRIDAY
WITH A WEAK FRONT MOVING SOUTH. WEAK FRONT COMBINED WITH PERTURBATIONS
WITHIN THE FLOW WILL ENHANCE SHOWERS AND THUNDERSTORMS ACROSS THE
CWA. THE BOUNDARY WILL STALLED OVER DEEP SOUTH TEXAS WITH WINDS
REMAINING EASTERLY INTO SATURDAY. AN ABUNDANT SURGE OF MOISTURE
WILL MOVE INTO THE AREA CONTINUING THE DEVELOPMENT OF MORE SHOWERS
AND THUNDERSTORMS ACROSS THE WESTERN COUNTIES THIS WEEKEND. MODEL
GUIDANCE CONTINUE TO SHOW ABOVE 1.5 IN OF PRECIPITABLE WATER
THROUGH THE WEEKEND WHICH WILL FAVOR THE DEVELOPMENT WITH THIS
TROUGH AS IT MOVES EASTWARD. DRIER AIR MASS MOVES INTO THE AREA
MONDAY WITH LESS SIDE TROUGH DEVELOPING OVER SOUTH CENTRAL TEXAS.
THIS WILL LIMIT THE POTENTIAL FOR RAIN BUT A FEW ISOLATED SHOWERS
CAN`T BE RULED NEAR THE COAST WITH THE SEABREEZE. THE RIDGE WILL
BE IN CONTROL OF THE AREA MONDAY AND TUESDAY LIMITING THE
POTENTIAL FOR RAIN THROUGH MID WEEK. THE SOUTHERLY FLOW WILL
INCREASE TO MORE BREEZE CONDITIONS MONDAY AS THE NEXT UPPER TROUGH
STRENGTHENS OVER THE PAC NORTHWEST. MODELS ARE IN PRETTY GOOD
AGREEMENT WITH GFS BEEN SLIGHTLY MORE PROGRESSIVE WITH THE NEXT
LOW PRESSURE SYSTEM WHILE THE ECMWF IS A BIT SLOWER. EVEN WITH THE
SLIGHT DIFFERENCE STILL SHOW THE POTENTIAL FOR RAIN FOR THE
WEEKEND AND THE DRY AIR FILTERING IN BY EARLY NEXT WEEK. LEAN
TOWARDS A BLEND OF THE TWO MODELS FOR THIS PACKAGE.
&&
.MARINE...TONIGHT THROUGH THURSDAY NIGHT...SEAS WERE NEAR 4 FEET
WITH EAST TO SOUTHEAST WINDS NEAR 10 KNOTS AT BUOY020 EARLY THIS
AFTERNOON. LIGHT TO MODERATE SOUTHEAST WINDS WILL PREVAIL ACROSS
THE COASTAL WATERS TONIGHT INTO THURSDAY WITH LOW PRESSURE ACROSS
NORTHEAST MEXICO AND A WEAK COLD FRONT DRAPED ACROSS NORTH TEXAS.
THE BOUNDARY WILL MOVE INTO SOUTH TX THURS NIGHT AND THIS WILL
CONTINUE TO PROVIDE A WEAK PRESSURE GRADIENT ACROSS THE LOWER TX
COAST.
FRIDAY THROUGH TUESDAY...SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
FOR THE EARLY PORTION OF THE LONG TERM PERIOD AS ABUNDANT MOISTURE
IN THE REGION WILL ALLOW FOR CONVECTION TO CONTINUE. EXPECT A
MODERATE SOUTHEAST FLOW ACROSS THE GULF WITH SEAS BETWEEN 2 TO 4
FEET THROUGH THE WEEKEND. RIDGE BEGINS TO BUILD LOWERING SEAS EVEN
LESS THAN 2 FEET SAT AND SUN. AN INFLUX OF MOISTURE WILL SURGE
NORTH SAT NIGHT INTO SUN INCREASING THE CHANCE OF SHOWERS ONCE
AGAIN. SEAS WILL BEGIN TO INCREASE INTO MONDAY AS A STRONG SURFACE
LOW STRENGTHENS OVER THE CENTRAL PLAINS. SEAS WILL BEGIN TO BUILD
TO 3 TO 6 FEET WITH SCEC POSSIBLE.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 72 82 71 80 / 20 20 20 20
BROWNSVILLE 72 85 71 83 / 20 20 20 30
HARLINGEN 71 87 70 84 / 20 20 20 30
MCALLEN 72 90 71 87 / 30 30 20 30
RIO GRANDE CITY 71 92 70 88 / 40 20 30 30
SOUTH PADRE ISLAND 72 78 71 77 / 20 20 20 20
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
61/67
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1247 PM CDT WED APR 20 2016
.AVIATION...
STABLE AIR BEHIND EARLY MORNING CONVECTION HAS SETTLED INTO THE
AREA. KDRT STILL HAS AN MVFR CIG...BUT CONDITIONS ELSEWHERE ARE
MOSTLY VFR. WE EXPECT SOME TSRA TO FORM OVER THE HILL COUNTRY THIS
EVENING AND APPROACH THE AUSTIN METRO AREA FROM THE WEST...BUT
HAVE LEFT MENTION OUT OF THE TAFS SINCE THE RISK IS LOW.
OTHERWISE...EXPECT IFR CIGS AND MVFR VSBYS TO DEVELOP BY 05-07Z
AND CONTINUE TO MID-MORNING THURSDAY. ALL MESOSCALE MODELS SHOW
ANOTHER QLCS MOVING THROUGH EAST TEXAS THURSDAY MORNING...SO WE
PUT VCSH IN THE KSAT/KAUS EXTENDED TAFS TO GIVE INDICATION ON
INTENSITY AND TIMING.
&&
.PREV DISCUSSION... /ISSUED 924 AM CDT WED APR 20 2016/
UPDATE...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE ALONG AND
BEHIND AN OUTFLOW BOUNDARY PUSHING ALONG HIGHWAY 90. A WEAK COLD
FRONT IS SLOWLY PUSHING ACROSS THE NORTHERN HILL COUNTRY PER
LATEST SURFACE OBSERVATIONS AND SPC MESOSCALE ANALYSIS PAGE. THIS
ACTIVITY IS EXPECTED TO CONTINUE THROUGH THE AFTERNOON AS IT
SHIFTS TO THE SOUTH AND EAST. BOTH HRRR AND RAP 13 MODELS SHOW A
DOWNWARD TREND ON THE SHOWER AND THUNDERSTORM ACTIVITY FOR THE
SHORT TERM/FIRST PERIOD. LATEST KEWX RADAR LOOPS SHOW A DECREASE
IN THE INTENSITY OF SHOWERS AND STORMS. NEW STORMS DEVELOPMENT ARE
POSSIBLE ACROSS THE SOUTHERN EDWARDS PLATEAU AND THE RIO GRANDE
AREAS THIS AFTERNOON AS THE TAIL END OF THE WEAK COLD FRONT
PUSHES TO THE SOUTH AS IT MEETS WITH THE PASSAGE OF AN UPPER SHORT
WAVE.
FLASH FLOOD WATCH CONTINUES IN EFFECT THROUGH 1 PM THIS AFTERNOON
FOR THE EASTERN COUNTIES OF SOUTH CENTRAL TEXAS (MORE DETAILS ON
THIS IN THE WATCHES/WARNINGS/ADVISORIES SECTION).
NEW RAINFALL AMOUNTS(NEXT 3 TO 6 HOURS)THROUGH THIS AFTERNOON
COULD RANGE FROM 1 TO 2 INCHES ACCORDING TO KEWX DOPPLER RADAR
ESTIMATES AND REFLECTIVITY TRENDS.
PREV DISCUSSION... /ISSUED 611 AM CDT WED APR 20 2016/
AVIATION...
WEAKENING COMPLEX OF SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE
TO TREK SOUTHWARD. WILL BEGIN TAFAUS FOR THE FIRST FEW HOURS WITH
-RA PREVAILING BUT WILL TEMPO -TSRA TO COVER THE THREAT FOR THE
ISOLATED THUNDERSTORMS. FOR THE SAN ANTONIO SITES...WILL ONLY
MENTION VCSH LATER THIS MORNING AS CONFIDENCE IS A BIT LESS THIS
SYSTEM MAKES IT THIS FAR SOUTH. CEILINGS ARE PRESENTLY AROUND LOW
MVFR OR IFR AND THESE RESTRICTIONS SHOULD REMAIN IN PLACE THROUGH
THE EARLY AFTERNOON. ANOTHER ROUND OF MVFR IS EXPECTED TOMORROW
NIGHT. BEYOND THIS MORNING...CANT RULE OUT ADDITIONAL ISOLATED OR
SCATTERED PRECIPITATION...BUT CHANCES ARE TOO LOW TO MENTION IN
THE TAFS AT THIS TIME.
PREV DISCUSSION... /ISSUED 359 AM CDT WED APR 20 2016/
SHORT TERM (TODAY THROUGH THURSDAY)...
SHOWERS AND THUNDERSTORMS ALONG A WACO TO SAN ANGELO TO BIG LAKE
LINE WERE MOVING TO THE SOUTHEAST AT 25 MPH. THE LINE WILL MOVE
INTO LLANO AND BURNET COUNTIES BY 5 AM AND THEN SLOW AS IT MOVES
FURTHER INTO SOUTH CENTRAL TEXAS. THE LINE/BOUNDARY STALLS ACROSS
SOUTH CENTRAL TEXAS LATER TODAY...MOST LIKELY AROUND THE I-10
CORRIDOR. RAINFALL AMOUNTS UP TO 1 TO 2 INCHES ARE POSSIBLE. THIS
RAINFALL WILL NOT CAUSE MUCH FLOOD THREAT FOR MOST AREAS. HAVE
MAINTAINED THE FLASH FLOOD WATCH EAST OF I-35 THROUGH MIDDAY TODAY
AS ANY ADDITIONAL RAIN WILL CAUSE NEW OR AGGRAVATE ONGOING
FLOODING IN THOSE AREAS THAT HAVE RECEIVED COPIOUS AMOUNTS OF RAIN
SINCE SUNDAY. THERE IS A POTENTIAL THE WATCH COULD BE EXTENDED.
LOCALLY HEAVY DOWNPOURS ARE POSSIBLE ALONG AND NEAR THE BOUNDARY
THIS AFTERNOON INTO EVENING AND AGAIN ON THURSDAY. CAPES AVERAGING
AROUND 2500 J/KG AND 0-6KM SHEAR OF 25 TO 35 KTS INDICATE A
MARGINAL RISK OF STRONG TO SEVERE STORMS DURING THE AFTERNOON INTO
EARLY EVENING HOURS TODAY AND THURSDAY. HAIL AND STRONG WIND GUSTS
ARE THE MAIN THREATS.
LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...
THE PESKY UPPER LEVEL LOW OPENS INTO TROUGH ALONG THE MISSISSIPPI
VALLEY THURSDAY NIGHT SENDING A WEAK COLD FRONT ACROSS SOUTH
CENTRAL TEXAS. SHOWERS AND THUNDERSTORMS ARE POSSIBLE ALONG THE
FRONT. RIDGING AT THE SURFACE AND ALOFT IS INDICATED FRIDAY AND
SATURDAY. THE AIRMASS DRIES AND STABILIZES ACROSS MOST OF SOUTH
CENTRAL TEXAS. HOWEVER...A MOIST SOUTHEASTERLY FLOW UP THE RIO
GRANDE WILL MAINTAIN LOW CHANCES OF RAIN THERE ON FRIDAY AND
SATURDAY. A COMPACT UPPER LEVEL TROUGH DEVELOPS OVER NORTHWESTERN
MEXICO ON SATURDAY AND MOVES ACROSS TEXAS ON SUNDAY INTO EARLY
MONDAY BRINGING RAIN CHANCES. A FEW MODELS SHOW LOCALLY HEAVY
DOWNPOURS. RAIN CHANCES RETURN THE MIDDLE OF NEXT WEEK AS ANOTHER
UPPER LEVEL TROUGH TAKES SHAPE OVER THE WESTERN STATES WITH A
PACIFIC FRONT/DRYLINE MOVING INTO OUR AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 65 80 61 80 58 / 30 40 30 10 0
AUSTIN BERGSTROM INTL AIRPORT 64 79 60 79 56 / 30 40 30 10 0
NEW BRAUNFELS MUNI AIRPORT 64 80 62 80 58 / 30 40 40 10 0
BURNET MUNI AIRPORT 63 77 57 77 56 / 30 40 20 10 0
DEL RIO INTL AIRPORT 66 85 63 82 64 / 20 30 30 20 10
GEORGETOWN MUNI AIRPORT 63 77 58 78 56 / 30 50 20 10 0
HONDO MUNI AIRPORT 65 82 62 81 60 / 30 40 40 10 0
SAN MARCOS MUNI AIRPORT 64 79 61 79 57 / 30 40 40 10 0
LA GRANGE - FAYETTE REGIONAL 66 79 62 80 57 / 30 50 40 10 0
SAN ANTONIO INTL AIRPORT 66 80 63 80 60 / 30 40 40 10 0
STINSON MUNI AIRPORT 66 82 64 81 61 / 30 40 40 10 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...26
SYNOPTIC/GRIDS...17
PUBLIC SERVICE/DATA COLLECTION...TREADWAY
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1245 PM CDT WED APR 20 2016
.AVIATION...
LINE OF STORMS ABOUT TO PUSH OFF COAST. LINGERING -RA MAY LINGER
FOR A FEW HOURS IN ITS WAKE UNTIL THE WHOLE DISTURBANCE MOVES
OUT...BUT CIGS WILL MOVE INTO VFR TERRITORY FAIRLY QUICKLY BEHIND
THE LEADING EDGE. MAYBE SOME ISO LATE AFTN CELLS, BUT OVERALL
EXPECT A LULL IN SIGNIFICANT WX FOR THE REST OF THE AFTN &
EVENING. CIGS MIGRATE BACK DOWN INTO MVFR & IFR OVERNIGHT.
ATTENTION TURNS TO N TX LATE TONIGHT WHERE ANOTHER STORM COMPLEX
DEVELOPS AND MOVES TOWARD SE TX. SET UP LOOKS SIMILAR TO TODAYS
WITH GRADUAL WEAKENING AS IT ARRIVES. TIMING IS UNCERTAIN...BUT
ANTICIPATE THE ARRIVAL SOMETIME AFTER SUNRISE CLL...AND HOU METRO
AREA TOWARD LATE MORNING. LATER SHIFTS WILL NEED TO FINE TUNE
TIMING AND TAFS AS TRENDS ARE ESTABLISHED. 47
&&
.PREV DISCUSSION... /ISSUED 1018 AM CDT WED APR 20 2016/
WEAKENING LINE OF STORMS WAS PUSHING INTO POLK...SAN JACINTO...
MONTGOMERY...HARRIS...FORT BEND...AND COLORADO COUNTIES AT 10 AM.
LIGHT RAIN WAS OCCURRING BEHIND THE SYSTEM. THE NAM12 HAS HAD A
DECENT HANDLE ON EVENTS SO FAR...AND THE MODEL CLEARS THE SYSTEM
OUT BY THE EARLY AFTERNOON. THE RAP AND TEXAS TECH BOTH SHOW SOME
SCATTERED REDEVELOPMENT IS POSSIBLE DURING THE MID AND LATE
AFTERNOON PERIOD. TRIMMED POPS DOWNWARD FOR THIS AFTERNOON TO
ACCOUNT FOR THE LESSENING RAIN CHANCES IN THE MODEL.
THE 12Z SOUNDINGS AT KLCH AND KCRP BOTH HAD A PW OF 1.5/1.6
INCHES. RAINFALL AMOUNTS FROM THE RAIN GAUGE NETWORK WITH THE
SYSTEM HAS BEEN UNDER A HALF AN INCH...WHILE RADAR HAS SHOWN SOME
LOCALIZED 1 INCH TOTALS. THIS POTENTIAL WILL LINGER OVER THE
CENTRAL AND COASTAL COUNTIES AHEAD OF THE LINE IN THE FLASH FLOOD
WATCH AREA. BECAUSE OF THE LESS EXPECTED COVERAGE IN THE NORTH...
HAVE TAKEN OUT WALKER...GRIMES...BRAZOS...AND BURLESON COUNTIES
FROM THE FLASH FLOOD WATCH. THE WATCH STILL GOES THROUGH 7 PM THIS
EVENING FOR THE REMAINING COUNTIES...AND WILL MAKE A DECISION
LATER THIS AFTERNOON ON WHETHER OR NOT TO EXTEND THE WATCH. 40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 79 67 77 57 79 / 60 30 50 30 10
HOUSTON (IAH) 79 67 80 64 81 / 60 40 70 40 10
GALVESTON (GLS) 75 70 76 69 76 / 50 30 50 30 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES: AUSTIN...BRAZORIA...CHAMBERS...COLORADO...FORT
BEND...GALVESTON...HARRIS...LIBERTY...MONTGOMERY...POLK...
SAN JACINTO...WALLER...WASHINGTON...WHARTON.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1208 PM CDT WED APR 20 2016
.MESOSCALE UPDATE...
...SOME SEVERE WEATHER POSSIBLE TODAY IN MAINLY THE SOUTH CENTRAL
AND SOUTHEAST TX PANHANDLE...
* SYNOPTIC OVERVIEW: WE`LL SEE ONE LAST GASP SHRTWV TROUGH THIS
AFTERNOON FROM THE NOW POSITIVELY TILTED UPR LOW THAT HAS CAUSED
WEATHER EXCITEMENT AROUND THE AREA THE PAST 5 DAYS. WATER VAPOR
ANALYSIS PLACES THE UPR LOW NEAR NORTH PLATTE, NE THIS MORNING WITH
THE LOW EXPECTED TO LIFT TO NEAR OMAHA TONIGHT. THE NW FLOW SHRTWV
WILL BEGIN TO IMPACT THE AREA EARLY THIS AFTERNOON, QUICKLY
CROSSING THE CWA THIS EVENING. ASCENT FROM THE TROUGH AND ASSOC
JET STREAK WILL BE ENOUGH TO SPAWN SCATTERED SHOWERS AND
THUNDERSTORMS THIS AFTERNOON/EVENING.
* MESOSCALE: SHEAR PROFILES WILL BE FAVORABLE FOR ORGANIZED
CONVECTION THOUGH SOMEWHAT WEAK INSTABILITY (IE MLCAPE VALUES OF
MAYBE 300-600 J/KG) SHOULD KEEP THIS FROM BEING A BARN BURNER OF A
DAY. NAM MLCAPE PROGS OF 750-1000 J/KG THIS AFTERNOON JUST EAST OF
KAMA SEEM TO BE OVERDONE AS THE NAM HAS OVER-ANALYZED THE AMOUNT
OF LOW-LVL MOISTURE DOWNSTATE SO FAR THIS MORNING. DO THINK THAT
THE HIGHER SIDE OF RAP/HRRR VALUES OF AROUND 500 J/KG MLCAPE COULD
BE REALIZED THOUGH GIVEN THE RAPID REDUCTION OF LOW CLOUD COVER
SEEN IN LATEST GOES SUPER RAPID SCAN VIS SAT OBSERVATIONS.
* THREATS: THE CAPE DISTRIBUTION LOOKS TO MOST FAVOR ISOLATED
DOWNBURST WINDS THIS AFTERNOON GIVEN A SOMEWHAT DEEP/DRY SUBCLOUD
LAYER. WITH THE PROPENSITY FOR THE STRONGEST UPDRAFTS TO WANT TO
ORGANIZE GIVEN THE FAVORABLE SHEAR PROFILE, SVR HAIL TO THE SIZE OF
GOLF BALLS CANNOT BE RULED OUT IN STORMS THAT TAKE ON SUPERCELLULAR
CHARACTERISTICS. THE TORNADO WINDOW LOOKS SMALL BOTH SPATIALLY AND
TEMPORALLY BUT MAY BRIEFLY EXIST FOR AN HOUR EITHER SIDE OF SUNSET
FOR A WEAK ISOLATED TORNADO SOMEWHERE IN THE SE PART OF THE TX
PANHANDLE. THE RAPID NW TO SE STORM MOTIONS SHOULD PRECLUDE MUCH OF
A FLOOD THREAT TODAY.
* TIMING & LOCATION: THE BEST CHANCES FOR SEVERE WEATHER THIS
AFTERNOON WILL BE IN THE SOUTH CENTRAL AND SOUTHEAST TX PANHANDLE,
THOUGH ISOLATED STRONG TO SEVERE WIND GUSTS COULD OCCUR AS FAR
NORTH AS DUMAS OR BORGER. AMARILLO WILL BE ON THE WESTERN EDGE OF
THE THREAT, BUT A STRONG OR SEVERE STORM CANNOT BE RULED OUT FOR
THE CITY. TIMING-WISE, THE BEST WINDOW WILL PROBABLY BE FROM AROUND
5PM-10PM.
SIMPSON/LORENZEN
.AVIATION...18Z TAFS...MVFR CIG AOA 1500 FT AGL SHOULD GRADUALLY GIVE
WAY TO CIG AOA 5K FT AGL IN ADVANCE OF A SHORTWAVE TROUGH. SOUTH TO
SOUTHWEST WINDS BTWN 10 TO 20 KTS WILL CONTINUE THRU THE AFTN UNTIL A
WEAK COLD FRONT PASSES THROUGH THE REGION AROUND 20/21Z. THIS
INCOMING FRONT WILL PROVIDE A FOCUS FOR POSSIBLE SHOWERS AND
THUNDERSTORMS BTWN 20/21Z THRU 21/06Z...WITH SOME STORMS CAPABLE OF
APPROACHING SEVERE LEVELS DURING THE AFTN HOURS. AS THE FRONT PASSES...WINDS
WILL SHIFT TO THE NORTH BTWN 10 TO 20 KTS. VFR CONDITIONS ARE LIKELY
AFT 21/06Z AS DRIER AND MORE STABLE AIR MOVES IN BEHIND THE FRONTAL
BOUNDARY.
BIEDA
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 45 72 45 77 51 / 50 5 0 5 0
BEAVER OK 44 73 43 79 53 / 20 5 0 5 5
BOISE CITY OK 39 71 41 77 50 / 30 5 0 5 5
BORGER TX 46 75 47 79 54 / 50 5 0 5 5
BOYS RANCH TX 43 74 44 79 52 / 40 5 0 5 5
CANYON TX 44 73 44 77 49 / 40 5 0 0 0
CLARENDON TX 48 73 47 77 51 / 70 10 0 5 0
DALHART TX 41 72 42 77 49 / 40 5 0 5 5
GUYMON OK 42 73 43 79 52 / 20 5 0 5 5
HEREFORD TX 45 73 44 77 50 / 30 5 0 0 5
LIPSCOMB TX 46 74 44 78 53 / 30 5 0 5 5
PAMPA TX 45 70 46 77 52 / 60 10 0 5 5
SHAMROCK TX 49 74 46 78 51 / 70 10 0 5 5
WELLINGTON TX 51 76 47 79 51 / 70 10 0 5 0
&&
.PREV DISCUSSION... /ISSUED 410 AM CDT WED APR 20 2016/
DISCUSSION...
TAKING ANOTHER LOOK AT THE LATEST HIGH-RES MODELS...THE HRRR IS NOW
BACKING OFF FROM THE DEVELOPMENT OF DENSE FOG ACROSS THE PANHANDLES
THIS MORNING. WILL LIKELY TO NEED TO CANCEL BUT WILL HOLD OFF UNTIL
CLOSER TO DAYBREAK TO SEE IF ANY DENSE FOG DEVELOPS. IF NOT...WILL
CANCEL BEFORE SHIFT CHANGE THIS MORNING. OTHERWISE...LOW CLOUDS WILL
PREVAIL THIS MORNING AS THE VIGOROUS CLOSED UPPER LOW OVER THE
CENTRAL PLAINS STATES ALLOWS FOR A VORT LOBE TO ROTATE NORTHWEST TO
SOUTHEAST ON THE BASAL OF THE UPPER TROUGH BY 00Z TO 06Z THURSDAY
ACROSS THE FORECAST AREA. CONVECTION SHOULD DEVELOP AFTER 20Z TO 22Z
TODAY...MAINLY OVER THE SOUTHERN HALF OF THE TEXAS PANHANDLE...WITH
THE SEVERE THREAT PRIMARILY ACROSS THE SOUTHEASTERN AND SOUTH CENTRAL
PORTIONS OF THE TEXAS PANHANDLE LATER TODAY AND TONIGHT. CONVECTION
SHOULD QUICKLY EXIT THE PANHANDLES BY 12Z THURSDAY AS AN UPPER RIDGE
BUILDS IN FROM THE WEST LATE THIS WEEK. WARMER AND DRIER CONDITIONS
EXPECTED THURSDAY THROUGH THE WEEKEND.
THE MEDIUM RANGE MODELS DIFFER WITH RESPECT TO THE NEXT CLOSED UPPER
LOW PROGGED TO MOVE OUT OF THE GREAT BASIN REGION THIS WEEKEND INTO
EARLY NEXT WEEK. THE ECMWF...WHICH WAS THE DRIER MODEL 24 HOURS
AGO...IS NOW FORECASTING AN OPEN WAVE TO TRACK NORTHEAST OUT OF BAJA
CALIFORNIA AND NORTHWEST MEXICO FRIDAY NIGHT AND SATURDAY INTO
SOUTHWEST TEXAS BY SATURDAY NIGHT AND SUNDAY. THE MAIN CLOSED UPPER
LOW IS FORECAST TO LIFT EAST AND NORTH OUT OF THE GREAT BASIN REGION
INTO THE CENTRAL ROCKIES AND NORTHERN PLAINS STATES BY EARLY NEXT
WEEK. THE ECMWF BREAKS OUT QPF SATURDAY AFTERNOON ACROSS THE
NORTHWESTERN PORTIONS OF THE FORECAST AREA SATURDAY AFTERNOON BUT
KEEPS THE REMAINDER OF THE WEEKEND AND EARLY NEXT WEEK DRY. THE GFS
IS COMPLETELY THE OPPOSITE OF 24 HOURS AGO AND IS NOW KEEPING THE
CLOSED UPPER LOW OVER THE NORTHERN STREAM RATHER THAN THE SOUTHERN
STREAM. THE GFS ALSO FORECASTS AN OPEN WAVE LIFTING NORTH AND EAST
OUT BAJA CALIFORNIA AND NORTHWESTERN/NORTHERN MEXICO...HOWEVER THE
GFS KEEPS THE QPF WELL SOUTH OF THE PANHANDLES AND...LIKE THE
ECMWF...MAINTAINS A DRY FORECAST THROUGH THE END OF THE WEEKEND INTO
EARLY NEXT WEEK. THEREFORE...OPTED TO REMOVE POPS FROM SUNDAY AND GO
WITH A DRY AND UNSEASONABLY WARM FORECAST THIS WEEKEND INTO EARLY
NEXT WEEK. BREEZY TO WINDY THIS WEEKEND AS A DEEPENING SURFACE TROUGH
DEVELOPS TO THE LEE OF THE ROCKIES WHICH WILL THEN TRACK EAST INTO
THE FORECAST AREA SUNDAY. A COLD FRONT IS FORECAST TO PUSH ACROSS THE
PANHANDLES EARLY NEXT WEEK WITH NO CONVECTION ASSOCIATED WITH THE
FRONT.
SCHNEIDER
FIRE WEATHER...
A DEEPENING SURFACE TROUGH OVER EASTERN COLORADO OR WESTERN KANSAS
SOUTHWARD TO NEAR THE TEXAS AND NEW MEXICO STATE LINE WILL TRACK
EAST INTO THE TEXAS AND OKLAHOMA PANHANDLES ON SUNDAY. INCREASING
DOWNSLOPING SOUTHWESTERLY 20 FOOT WINDS AND MINIMUM AFTERNOON
HUMIDITIES FALLING INTO THE 15 TO 20 PERCENT RANGE ACROSS MAINLY THE
WESTERN SECTIONS OF THE PANHANDLES COULD POSSIBLY RESULT IN ELEVATED
FIRE WEATHER CONDITIONS SUNDAY AFTERNOON INTO EARLY SUNDAY EVENING.
SCHNEIDER
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
9/98
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1139 AM CDT WED APR 20 2016
.MESOSCALE UPDATE...
...SOME SEVERE WEATHER POSSIBLE TODAY IN MAINLY THE SOUTH CENTRAL
AND SOUTHEAST TX PANHANDLE...
* SYNOPTIC OVERVIEW: WE`LL SEE ONE LAST GASP SHRTWV TROUGH THIS
AFTERNOON FROM THE NOW POSITIVELY TILTED UPR LOW THAT HAS CAUSED
WEATHER EXCITEMENT AROUND THE AREA THE PAST 5 DAYS. WATER VAPOR
ANALYSIS PLACES THE UPR LOW NEAR NORTH PLATTE, NE THIS MORNING WITH
THE LOW EXPECTED TO LIFT TO NEAR OMAHA TONIGHT. THE NW FLOW SHRTWV
WILL BEGIN TO IMPACT THE AREA EARLY THIS AFTERNOON, QUICKLY
CROSSING THE CWA THIS EVENING. ASCENT FROM THE TROUGH AND ASSOC
JET STREAK WILL BE ENOUGH TO SPAWN SCATTERED SHOWERS AND
THUNDERSTORMS THIS AFTERNOON/EVENING.
* MESOSCALE: SHEAR PROFILES WILL BE FAVORABLE FOR ORGANIZED
CONVECTION THOUGH SOMEWHAT WEAK INSTABILITY (IE MLCAPE VALUES OF
MAYBE 300-600 J/KG) SHOULD KEEP THIS FROM BEING A BARN BURNER OF A
DAY. NAM MLCAPE PROGS OF 750-1000 J/KG THIS AFTERNOON JUST EAST OF
KAMA SEEM TO BE OVERDONE AS THE NAM HAS OVER-ANALYZED THE AMOUNT
OF LOW-LVL MOISTURE DOWNSTATE SO FAR THIS MORNING. DO THINK THAT
THE HIGHER SIDE OF RAP/HRRR VALUES OF AROUND 500 J/KG MLCAPE COULD
BE REALIZED THOUGH GIVEN THE RAPID REDUCTION OF LOW CLOUD COVER
SEEN IN LATEST GOES SUPER RAPID SCAN VIS SAT OBSERVATIONS.
* THREATS: THE CAPE DISTRIBUTION LOOKS TO MOST FAVOR ISOLATED
DOWNBURST WINDS THIS AFTERNOON GIVEN A SOMEWHAT DEEP/DRY SUBCLOUD
LAYER. WITH THE PROPENSITY FOR THE STRONGEST UPDRAFTS TO WANT TO
ORGANIZE GIVEN THE FAVORABLE SHEAR PROFILE, SVR HAIL TO THE SIZE OF
GOLF BALLS CANNOT BE RULED OUT IN STORMS THAT TAKE ON SUPERCELLULAR
CHARACTERISTICS. THE TORNADO WINDOW LOOKS SMALL BOTH SPATIALLY AND
TEMPORALLY BUT MAY BRIEFLY EXIST FOR AN HOUR EITHER SIDE OF SUNSET
FOR A WEAK ISOLATED TORNADO SOMEWHERE IN THE SE PART OF THE TX
PANHANDLE. THE RAPID NW TO SE STORM MOTIONS SHOULD PRECLUDE MUCH OF
A FLOOD THREAT TODAY.
* TIMING & LOCATION: THE BEST CHANCES FOR SEVERE WEATHER THIS
AFTERNOON WILL BE IN THE SOUTH CENTRAL AND SOUTH TX PANHANDLE,
THOUGH ISOLATED STRONG TO SEVERE WIND GUSTS COULD OCCUR AS FAR
NORTH AS DUMAS OR BORGER. AMARILLO WILL BE ON THE WESTERN EDGE OF
THE THREAT, BUT A STRONG OR SEVERE STORM CANNOT BE RULED OUT FOR
THE CITY. TIMING-WISE, THE BEST WINDOW WILL PROBABLY BE FROM AROUND
5PM-10PM.
SIMPSON/LORENZEN
&&
.PREV DISCUSSION... /ISSUED 648 AM CDT WED APR 20 2016/
AVIATION...
MVFR TO IFR CEILINGS EXPECTED TO PERSIST THIS MORNING. LIGHT TO
MODERATE SOUTHWEST LOW-LEVEL WINDS EXPECTED TO DEVELOP...BOOSTING
DRYING AND DISSIPATION/LIFTING OF LOW CLOUDS. CUMULUS CLOUDS
EXPECTED TO DEVELOP THIS AFTERNOON. SCATTERED THUNDERSTORMS
EXPECTED TO DEVELOP AFTER 21Z TODAY AS VORTICITY MAXIMUM ARRIVES FROM
NORTHWEST. WEAK COLD FRONT WILL SUPPORT THUNDERSTORM DEVELOPMENT
THROUGH THE EVENING. DRIER AND MORE STABLE AIR MOVES IN LATE
TONIGHT...WITH CLEARING EXPECTED.
COCKRELL
PREV DISCUSSION... /ISSUED 410 AM CDT WED APR 20 2016/
DISCUSSION...
TAKING ANOTHER LOOK AT THE LATEST HIGH-RES MODELS...THE HRRR IS NOW
BACKING OFF FROM THE DEVELOPMENT OF DENSE FOG ACROSS THE PANHANDLES
THIS MORNING. WILL LIKELY TO NEED TO CANCEL BUT WILL HOLD OFF UNTIL
CLOSER TO DAYBREAK TO SEE IF ANY DENSE FOG DEVELOPS. IF NOT...WILL
CANCEL BEFORE SHIFT CHANGE THIS MORNING. OTHERWISE...LOW CLOUDS WILL
PREVAIL THIS MORNING AS THE VIGOROUS CLOSED UPPER LOW OVER THE
CENTRAL PLAINS STATES ALLOWS FOR A VORT LOBE TO ROTATE NORTHWEST TO
SOUTHEAST ON THE BASAL OF THE UPPER TROUGH BY 00Z TO 06Z THURSDAY
ACROSS THE FORECAST AREA. CONVECTION SHOULD DEVELOP AFTER 20Z TO 22Z
TODAY...MAINLY OVER THE SOUTHERN HALF OF THE TEXAS PANHANDLE...WITH
THE SEVERE THREAT PRIMARILY ACROSS THE SOUTHEASTERN AND SOUTH CENTRAL
PORTIONS OF THE TEXAS PANHANDLE LATER TODAY AND TONIGHT. CONVECTION
SHOULD QUICKLY EXIT THE PANHANDLES BY 12Z THURSDAY AS AN UPPER RIDGE
BUILDS IN FROM THE WEST LATE THIS WEEK. WARMER AND DRIER CONDITIONS
EXPECTED THURSDAY THROUGH THE WEEKEND.
THE MEDIUM RANGE MODELS DIFFER WITH RESPECT TO THE NEXT CLOSED UPPER
LOW PROGGED TO MOVE OUT OF THE GREAT BASIN REGION THIS WEEKEND INTO
EARLY NEXT WEEK. THE ECMWF...WHICH WAS THE DRIER MODEL 24 HOURS
AGO...IS NOW FORECASTING AN OPEN WAVE TO TRACK NORTHEAST OUT OF BAJA
CALIFORNIA AND NORTHWEST MEXICO FRIDAY NIGHT AND SATURDAY INTO
SOUTHWEST TEXAS BY SATURDAY NIGHT AND SUNDAY. THE MAIN CLOSED UPPER
LOW IS FORECAST TO LIFT EAST AND NORTH OUT OF THE GREAT BASIN REGION
INTO THE CENTRAL ROCKIES AND NORTHERN PLAINS STATES BY EARLY NEXT
WEEK. THE ECMWF BREAKS OUT QPF SATURDAY AFTERNOON ACROSS THE
NORTHWESTERN PORTIONS OF THE FORECAST AREA SATURDAY AFTERNOON BUT
KEEPS THE REMAINDER OF THE WEEKEND AND EARLY NEXT WEEK DRY. THE GFS
IS COMPLETELY THE OPPOSITE OF 24 HOURS AGO AND IS NOW KEEPING THE
CLOSED UPPER LOW OVER THE NORTHERN STREAM RATHER THAN THE SOUTHERN
STREAM. THE GFS ALSO FORECASTS AN OPEN WAVE LIFTING NORTH AND EAST
OUT BAJA CALIFORNIA AND NORTHWESTERN/NORTHERN MEXICO...HOWEVER THE
GFS KEEPS THE QPF WELL SOUTH OF THE PANHANDLES AND...LIKE THE
ECMWF...MAINTAINS A DRY FORECAST THROUGH THE END OF THE WEEKEND INTO
EARLY NEXT WEEK. THEREFORE...OPTED TO REMOVE POPS FROM SUNDAY AND GO
WITH A DRY AND UNSEASONABLY WARM FORECAST THIS WEEKEND INTO EARLY
NEXT WEEK. BREEZY TO WINDY THIS WEEKEND AS A DEEPENING SURFACE TROUGH
DEVELOPS TO THE LEE OF THE ROCKIES WHICH WILL THEN TRACK EAST INTO
THE FORECAST AREA SUNDAY. A COLD FRONT IS FORECAST TO PUSH ACROSS THE
PANHANDLES EARLY NEXT WEEK WITH NO CONVECTION ASSOCIATED WITH THE
FRONT.
SCHNEIDER
FIRE WEATHER...
A DEEPENING SURFACE TROUGH OVER EASTERN COLORADO OR WESTERN KANSAS
SOUTHWARD TO NEAR THE TEXAS AND NEW MEXICO STATE LINE WILL TRACK
EAST INTO THE TEXAS AND OKLAHOMA PANHANDLES ON SUNDAY. INCREASING
DOWNSLOPING SOUTHWESTERLY 20 FOOT WINDS AND MINIMUM AFTERNOON
HUMIDITIES FALLING INTO THE 15 TO 20 PERCENT RANGE ACROSS MAINLY THE
WESTERN SECTIONS OF THE PANHANDLES COULD POSSIBLY RESULT IN ELEVATED
FIRE WEATHER CONDITIONS SUNDAY AFTERNOON INTO EARLY SUNDAY EVENING.
SCHNEIDER
PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 69 45 72 45 77 / 20 50 5 0 5
BEAVER OK 68 44 73 43 79 / 20 20 5 0 5
BOISE CITY OK 65 39 71 41 77 / 30 30 5 0 5
BORGER TX 70 46 75 47 79 / 20 50 5 0 5
BOYS RANCH TX 72 43 74 44 79 / 20 40 5 0 5
CANYON TX 71 44 73 44 77 / 20 40 5 0 0
CLARENDON TX 68 48 73 47 77 / 20 70 10 0 5
DALHART TX 67 41 72 42 77 / 30 40 5 0 5
GUYMON OK 67 42 73 43 79 / 20 20 5 0 5
HEREFORD TX 73 45 73 44 77 / 20 30 5 0 0
LIPSCOMB TX 69 46 74 44 78 / 10 30 5 0 5
PAMPA TX 67 45 70 46 77 / 20 60 10 0 5
SHAMROCK TX 69 49 74 46 78 / 20 70 10 0 5
WELLINGTON TX 70 51 76 47 79 / 20 70 10 0 5
PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 69 45 72 45 77 / 20 50 5 0 5
BEAVER OK 68 44 73 43 79 / 20 20 5 0 5
BOISE CITY OK 65 39 71 41 77 / 30 30 5 0 5
BORGER TX 70 46 75 47 79 / 20 50 5 0 5
BOYS RANCH TX 72 43 74 44 79 / 20 40 5 0 5
CANYON TX 71 44 73 44 77 / 20 40 5 0 0
CLARENDON TX 68 48 73 47 77 / 20 70 10 0 5
DALHART TX 67 41 72 42 77 / 30 40 5 0 5
GUYMON OK 67 42 73 43 79 / 20 20 5 0 5
HEREFORD TX 73 45 73 44 77 / 20 30 5 0 0
LIPSCOMB TX 69 46 74 44 78 / 10 30 5 0 5
PAMPA TX 67 45 70 46 77 / 20 60 10 0 5
SHAMROCK TX 69 49 74 46 78 / 20 70 10 0 5
WELLINGTON TX 70 51 76 47 79 / 20 70 10 0 5
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
9/99
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1018 AM CDT WED APR 20 2016
.DISCUSSION...
WEAKENING LINE OF STORMS WAS PUSHING INTO POLK...SAN JACINTO...
MONTGOMERY...HARRIS...FORT BEND...AND COLORADO COUNTIES AT 10 AM.
LIGHT RAIN WAS OCCURRING BEHIND THE SYSTEM. THE NAM12 HAS HAD A
DECENT HANDLE ON EVENTS SO FAR...AND THE MODEL CLEARS THE SYSTEM
OUT BY THE EARLY AFTERNOON. THE RAP AND TEXAS TECH BOTH SHOW SOME
SCATTERED REDEVELOPMENT IS POSSIBLE DURING THE MID AND LATE
AFTERNOON PERIOD. TRIMMED POPS DOWNWARD FOR THIS AFTERNOON TO
ACCOUNT FOR THE LESSENING RAIN CHANCES IN THE MODEL.
THE 12Z SOUNDINGS AT KLCH AND KCRP BOTH HAD A PW OF 1.5/1.6
INCHES. RAINFALL AMOUNTS FROM THE RAIN GAUGE NETWORK WITH THE
SYSTEM HAS BEEN UNDER A HALF AN INCH...WHILE RADAR HAS SHOWN SOME
LOCALIZED 1 INCH TOTALS. THIS POTENTIAL WILL LINGER OVER THE
CENTRAL AND COASTAL COUNTIES AHEAD OF THE LINE IN THE FLASH FLOOD
WATCH AREA. BECAUSE OF THE LESS EXPECTED COVERAGE IN THE NORTH...
HAVE TAKEN OUT WALKER...GRIMES...BRAZOS...AND BURLESON COUNTIES
FROM THE FLASH FLOOD WATCH. THE WATCH STILL GOES THROUGH 7 PM THIS
EVENING FOR THE REMAINING COUNTIES...AND WILL MAKE A DECISION
LATER THIS AFTERNOON ON WHETHER OR NOT TO EXTEND THE WATCH.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 79 67 77 57 79 / 60 30 50 30 10
HOUSTON (IAH) 79 67 80 64 81 / 60 40 70 40 10
GALVESTON (GLS) 75 70 76 69 76 / 50 30 50 30 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES: AUSTIN...BRAZORIA...CHAMBERS...COLORADO...FORT
BEND...GALVESTON...HARRIS...LIBERTY...MONTGOMERY...POLK...
SAN JACINTO...WALLER...WASHINGTON...WHARTON.
GM...NONE.
&&
$$
DISCUSSION...40
AVIATION/MARINE...47
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
924 AM CDT WED APR 20 2016
.UPDATE...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE ALONG AND
BEHIND AN OUTFLOW BOUNDARY PUSHING ALONG HIGHWAY 90. A WEAK COLD
FRONT IS SLOWLY PUSHING ACROSS THE NORTHERN HILL COUNTRY PER
LATEST SURFACE OBSERVATIONS AND SPC MESOSCALE ANALYSIS PAGE. THIS
ACTIVITY IS EXPECTED TO CONTINUE THROUGH THE AFTERNOON AS IT
SHIFTS TO THE SOUTH AND EAST. BOTH HRRR AND RAP 13 MODELS SHOW A
DOWNWARD TREND ON THE SHOWER AND THUNDERSTORM ACTIVITY FOR THE
SHORT TERM/FIRST PERIOD. LATEST KEWX RADAR LOOPS SHOW A DECREASE
IN THE INTENSITY OF SHOWERS AND STORMS. NEW STORMS DEVELOPMENT ARE
POSSIBLE ACROSS THE SOUTHERN EDWARDS PLATEAU AND THE RIO GRANDE
AREAS THIS AFTERNOON AS THE TAIL END OF THE WEAK COLD FRONT
PUSHES TO THE SOUTH AS IT MEETS WITH THE PASSAGE OF AN UPPER SHORT
WAVE.
FLASH FLOOD WATCH CONTINUES IN EFFECT THROUGH 1 PM THIS AFTERNOON
FOR THE EASTERN COUNTIES OF SOUTH CENTRAL TEXAS (MORE DETAILS ON
THIS IN THE WATCHES/WARNINGS/ADVISORIES SECTION).
NEW RAINFALL AMOUNTS(NEXT 3 TO 6 HOURS)THROUGH THIS AFTERNOON
COULD RANGE FROM 1 TO 2 INCHES ACCORDING TO KEWX DOPPLER RADAR
ESTIMATES AND REFLECTIVITY TRENDS.
&&
.PREV DISCUSSION... /ISSUED 611 AM CDT WED APR 20 2016/
AVIATION...
WEAKENING COMPLEX OF SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE
TO TREK SOUTHWARD. WILL BEGIN TAFAUS FOR THE FIRST FEW HOURS WITH
-RA PREVAILING BUT WILL TEMPO -TSRA TO COVER THE THREAT FOR THE
ISOLATED THUNDERSTORMS. FOR THE SAN ANTONIO SITES...WILL ONLY
MENTION VCSH LATER THIS MORNING AS CONFIDENCE IS A BIT LESS THIS
SYSTEM MAKES IT THIS FAR SOUTH. CEILINGS ARE PRESENTLY AROUND LOW
MVFR OR IFR AND THESE RESTRICTIONS SHOULD REMAIN IN PLACE THROUGH
THE EARLY AFTERNOON. ANOTHER ROUND OF MVFR IS EXPECTED TOMORROW
NIGHT. BEYOND THIS MORNING...CANT RULE OUT ADDITIONAL ISOLATED OR
SCATTERED PRECIPITATION...BUT CHANCES ARE TOO LOW TO MENTION IN
THE TAFS AT THIS TIME.
PREV DISCUSSION... /ISSUED 359 AM CDT WED APR 20 2016/
SHORT TERM (TODAY THROUGH THURSDAY)...
SHOWERS AND THUNDERSTORMS ALONG A WACO TO SAN ANGELO TO BIG LAKE
LINE WERE MOVING TO THE SOUTHEAST AT 25 MPH. THE LINE WILL MOVE
INTO LLANO AND BURNET COUNTIES BY 5 AM AND THEN SLOW AS IT MOVES
FURTHER INTO SOUTH CENTRAL TEXAS. THE LINE/BOUNDARY STALLS ACROSS
SOUTH CENTRAL TEXAS LATER TODAY...MOST LIKELY AROUND THE I-10
CORRIDOR. RAINFALL AMOUNTS UP TO 1 TO 2 INCHES ARE POSSIBLE. THIS
RAINFALL WILL NOT CAUSE MUCH FLOOD THREAT FOR MOST AREAS. HAVE
MAINTAINED THE FLASH FLOOD WATCH EAST OF I-35 THROUGH MIDDAY TODAY
AS ANY ADDITIONAL RAIN WILL CAUSE NEW OR AGGRAVATE ONGOING
FLOODING IN THOSE AREAS THAT HAVE RECEIVED COPIOUS AMOUNTS OF RAIN
SINCE SUNDAY. THERE IS A POTENTIAL THE WATCH COULD BE EXTENDED.
LOCALLY HEAVY DOWNPOURS ARE POSSIBLE ALONG AND NEAR THE BOUNDARY
THIS AFTERNOON INTO EVENING AND AGAIN ON THURSDAY. CAPES AVERAGING
AROUND 2500 J/KG AND 0-6KM SHEAR OF 25 TO 35 KTS INDICATE A
MARGINAL RISK OF STRONG TO SEVERE STORMS DURING THE AFTERNOON INTO
EARLY EVENING HOURS TODAY AND THURSDAY. HAIL AND STRONG WIND GUSTS
ARE THE MAIN THREATS.
LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...
THE PESKY UPPER LEVEL LOW OPENS INTO TROUGH ALONG THE MISSISSIPPI
VALLEY THURSDAY NIGHT SENDING A WEAK COLD FRONT ACROSS SOUTH
CENTRAL TEXAS. SHOWERS AND THUNDERSTORMS ARE POSSIBLE ALONG THE
FRONT. RIDGING AT THE SURFACE AND ALOFT IS INDICATED FRIDAY AND
SATURDAY. THE AIRMASS DRIES AND STABILIZES ACROSS MOST OF SOUTH
CENTRAL TEXAS. HOWEVER...A MOIST SOUTHEASTERLY FLOW UP THE RIO
GRANDE WILL MAINTAIN LOW CHANCES OF RAIN THERE ON FRIDAY AND
SATURDAY. A COMPACT UPPER LEVEL TROUGH DEVELOPS OVER NORTHWESTERN
MEXICO ON SATURDAY AND MOVES ACROSS TEXAS ON SUNDAY INTO EARLY
MONDAY BRINGING RAIN CHANCES. A FEW MODELS SHOW LOCALLY HEAVY
DOWNPOURS. RAIN CHANCES RETURN THE MIDDLE OF NEXT WEEK AS ANOTHER
UPPER LEVEL TROUGH TAKES SHAPE OVER THE WESTERN STATES WITH A
PACIFIC FRONT/DRYLINE MOVING INTO OUR AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 79 65 80 61 80 / 60 30 40 30 10
AUSTIN BERGSTROM INTL AIRPORT 79 64 79 60 79 / 60 30 40 30 10
NEW BRAUNFELS MUNI AIRPORT 80 64 80 62 80 / 50 30 40 40 10
BURNET MUNI AIRPORT 78 63 77 57 77 / 60 30 40 20 10
DEL RIO INTL AIRPORT 83 66 85 63 82 / 20 20 30 30 20
GEORGETOWN MUNI AIRPORT 79 63 77 58 78 / 60 30 50 20 10
HONDO MUNI AIRPORT 81 65 82 62 81 / 30 30 40 40 10
SAN MARCOS MUNI AIRPORT 78 64 79 61 79 / 50 30 40 40 10
LA GRANGE - FAYETTE REGIONAL 79 66 79 62 80 / 60 30 50 40 10
SAN ANTONIO INTL AIRPORT 80 66 80 63 80 / 40 30 40 40 10
STINSON MUNI AIRPORT 82 66 82 64 81 / 40 30 40 40 10
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 1 PM CDT THIS AFTERNOON FOR THE FOLLOWING
COUNTIES: BASTROP...CALDWELL...DE WITT...FAYETTE...GONZALES...
LAVACA...LEE.
&&
$$
MESOSCALE/AVIATION...26
SYNOPTIC/GRIDS...17
PUBLIC SERVICE/DATA COLLECTION...TREADWAY
AREA FORECAST DISCUSSION
NWS AMARILLO TX
648 AM CDT WED APR 20 2016
.AVIATION...
MVFR TO IFR CEILINGS EXPECTED TO PERSIST THIS MORNING. LIGHT TO
MODERATE SOUTHWEST LOW-LEVEL WINDS EXPECTED TO DEVELOP...BOOSTING
DRYING AND DISSIPATION/LIFTING OF LOW CLOUDS. CUMULUS CLOUDS
EXPECTED TO DEVELOP THIS AFTERNOON. SCATTERED THUNDERSTORMS
EXPECTED TO DEVELOP AFTER 21Z TODAY AS VORTICITY MAXIMUM ARRIVES FROM
NORTHWEST. WEAK COLD FRONT WILL SUPPORT THUNDERSTORM DEVELOPMENT
THROUGH THE EVENING. DRIER AND MORE STABLE AIR MOVES IN LATE
TONIGHT...WITH CLEARING EXPECTED.
COCKRELL
&&
.PREV DISCUSSION... /ISSUED 410 AM CDT WED APR 20 2016/
DISCUSSION...
TAKING ANOTHER LOOK AT THE LATEST HIGH-RES MODELS...THE HRRR IS NOW
BACKING OFF FROM THE DEVELOPMENT OF DENSE FOG ACROSS THE PANHANDLES
THIS MORNING. WILL LIKELY TO NEED TO CANCEL BUT WILL HOLD OFF UNTIL
CLOSER TO DAYBREAK TO SEE IF ANY DENSE FOG DEVELOPS. IF NOT...WILL
CANCEL BEFORE SHIFT CHANGE THIS MORNING. OTHERWISE...LOW CLOUDS WILL
PREVAIL THIS MORNING AS THE VIGOROUS CLOSED UPPER LOW OVER THE
CENTRAL PLAINS STATES ALLOWS FOR A VORT LOBE TO ROTATE NORTHWEST TO
SOUTHEAST ON THE BASAL OF THE UPPER TROUGH BY 00Z TO 06Z THURSDAY
ACROSS THE FORECAST AREA. CONVECTION SHOULD DEVELOP AFTER 20Z TO 22Z
TODAY...MAINLY OVER THE SOUTHERN HALF OF THE TEXAS PANHANDLE...WITH
THE SEVERE THREAT PRIMARILY ACROSS THE SOUTHEASTERN AND SOUTH CENTRAL
PORTIONS OF THE TEXAS PANHANDLE LATER TODAY AND TONIGHT. CONVECTION
SHOULD QUICKLY EXIT THE PANHANDLES BY 12Z THURSDAY AS AN UPPER RIDGE
BUILDS IN FROM THE WEST LATE THIS WEEK. WARMER AND DRIER CONDITIONS
EXPECTED THURSDAY THROUGH THE WEEKEND.
THE MEDIUM RANGE MODELS DIFFER WITH RESPECT TO THE NEXT CLOSED UPPER
LOW PROGGED TO MOVE OUT OF THE GREAT BASIN REGION THIS WEEKEND INTO
EARLY NEXT WEEK. THE ECMWF...WHICH WAS THE DRIER MODEL 24 HOURS
AGO...IS NOW FORECASTING AN OPEN WAVE TO TRACK NORTHEAST OUT OF BAJA
CALIFORNIA AND NORTHWEST MEXICO FRIDAY NIGHT AND SATURDAY INTO
SOUTHWEST TEXAS BY SATURDAY NIGHT AND SUNDAY. THE MAIN CLOSED UPPER
LOW IS FORECAST TO LIFT EAST AND NORTH OUT OF THE GREAT BASIN REGION
INTO THE CENTRAL ROCKIES AND NORTHERN PLAINS STATES BY EARLY NEXT
WEEK. THE ECMWF BREAKS OUT QPF SATURDAY AFTERNOON ACROSS THE
NORTHWESTERN PORTIONS OF THE FORECAST AREA SATURDAY AFTERNOON BUT
KEEPS THE REMAINDER OF THE WEEKEND AND EARLY NEXT WEEK DRY. THE GFS
IS COMPLETELY THE OPPOSITE OF 24 HOURS AGO AND IS NOW KEEPING THE
CLOSED UPPER LOW OVER THE NORTHERN STREAM RATHER THAN THE SOUTHERN
STREAM. THE GFS ALSO FORECASTS AN OPEN WAVE LIFTING NORTH AND EAST
OUT BAJA CALIFORNIA AND NORTHWESTERN/NORTHERN MEXICO...HOWEVER THE
GFS KEEPS THE QPF WELL SOUTH OF THE PANHANDLES AND...LIKE THE
ECMWF...MAINTAINS A DRY FORECAST THROUGH THE END OF THE WEEKEND INTO
EARLY NEXT WEEK. THEREFORE...OPTED TO REMOVE POPS FROM SUNDAY AND GO
WITH A DRY AND UNSEASONABLY WARM FORECAST THIS WEEKEND INTO EARLY
NEXT WEEK. BREEZY TO WINDY THIS WEEKEND AS A DEEPENING SURFACE TROUGH
DEVELOPS TO THE LEE OF THE ROCKIES WHICH WILL THEN TRACK EAST INTO
THE FORECAST AREA SUNDAY. A COLD FRONT IS FORECAST TO PUSH ACROSS THE
PANHANDLES EARLY NEXT WEEK WITH NO CONVECTION ASSOCIATED WITH THE
FRONT.
SCHNEIDER
FIRE WEATHER...
A DEEPENING SURFACE TROUGH OVER EASTERN COLORADO OR WESTERN KANSAS
SOUTHWARD TO NEAR THE TEXAS AND NEW MEXICO STATE LINE WILL TRACK
EAST INTO THE TEXAS AND OKLAHOMA PANHANDLES ON SUNDAY. INCREASING
DOWNSLOPING SOUTHWESTERLY 20 FOOT WINDS AND MINIMUM AFTERNOON
HUMIDITIES FALLING INTO THE 15 TO 20 PERCENT RANGE ACROSS MAINLY THE
WESTERN SECTIONS OF THE PANHANDLES COULD POSSIBLY RESULT IN ELEVATED
FIRE WEATHER CONDITIONS SUNDAY AFTERNOON INTO EARLY SUNDAY EVENING.
SCHNEIDER
PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 69 45 72 45 77 / 20 50 5 0 5
BEAVER OK 68 44 73 43 79 / 20 20 5 0 5
BOISE CITY OK 65 39 71 41 77 / 30 30 5 0 5
BORGER TX 70 46 75 47 79 / 20 50 5 0 5
BOYS RANCH TX 72 43 74 44 79 / 20 40 5 0 5
CANYON TX 71 44 73 44 77 / 20 40 5 0 0
CLARENDON TX 68 48 73 47 77 / 20 70 10 0 5
DALHART TX 67 41 72 42 77 / 30 40 5 0 5
GUYMON OK 67 42 73 43 79 / 20 20 5 0 5
HEREFORD TX 73 45 73 44 77 / 20 30 5 0 0
LIPSCOMB TX 69 46 74 44 78 / 10 30 5 0 5
PAMPA TX 67 45 70 46 77 / 20 60 10 0 5
SHAMROCK TX 69 49 74 46 78 / 20 70 10 0 5
WELLINGTON TX 70 51 76 47 79 / 20 70 10 0 5
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 69 45 72 45 77 / 20 50 5 0 5
BEAVER OK 68 44 73 43 79 / 20 20 5 0 5
BOISE CITY OK 65 39 71 41 77 / 30 30 5 0 5
BORGER TX 70 46 75 47 79 / 20 50 5 0 5
BOYS RANCH TX 72 43 74 44 79 / 20 40 5 0 5
CANYON TX 71 44 73 44 77 / 20 40 5 0 0
CLARENDON TX 68 48 73 47 77 / 20 70 10 0 5
DALHART TX 67 41 72 42 77 / 30 40 5 0 5
GUYMON OK 67 42 73 43 79 / 20 20 5 0 5
HEREFORD TX 73 45 73 44 77 / 20 30 5 0 0
LIPSCOMB TX 69 46 74 44 78 / 10 30 5 0 5
PAMPA TX 67 45 70 46 77 / 20 60 10 0 5
SHAMROCK TX 69 49 74 46 78 / 20 70 10 0 5
WELLINGTON TX 70 51 76 47 79 / 20 70 10 0 5
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
03/11
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
642 AM CDT WED APR 20 2016
.AVIATION...
SCATTERED SHRA ARE DEVELOPING ACROSS THE AREA AS A LINE OF GENERALLY
WEAKENING SHRA/TSRA BEGINS MOVING INTO OUR NORTHERN AND WESTERN SECTIONS.
MOST TAF SITES ARE GOING WITH VCSH TEMPO TSRA AS THIS ACTIVITY SPREADS
ACROSS THE AREA THIS MORNING THROUGH EARLY THIS AFTERNOON. BOUNDARIES
FROM THESE STORMS MIGHT END UP HELPING TO FIRE ADDITIONAL STORM DEVELOPMENT
IN THE MID AFTERNOON THROUGH EARLY EVENING HOURS FROM ROUGHLY IAH SOUTHWARD...
BUT HARD TO PINPOINT EXACTLY WHERE THIS MIGHT SET UP. FOR LATER TODAY...JUST
GOING WITH VCSH UP NORTH AND VCTS DOWN SOUTH. GENERALLY EXPECT TO SEE
LOTS OF MVFR CEILINGS THROUGHOUT THE DAY. SHOULD SEE A BREAK IN STORM
ACTIVITY TONIGHT AS CEILINGS LOWER TO MVFR/IFR LEVELS FOLLOWED BY MORE
SHRA/TSRA DURING THE DAY TOMORROW. 42
&&
.PREV DISCUSSION... /ISSUED 346 AM CDT WED APR 20 2016/
DISCUSSION...
LATEST RADAR COMPOSITES SHOW MCS WORKING ACROSS NORTH CENTRAL
TEXAS. IT HAS BECOME MORE EAST TO WEST ORIENTED OVERNIGHT.
MESOSCALE MODELS...INCLUDING TTU WRF AND HRRR VERIFYING FAIRLY
WELL ATTM. INTERESTING TO NOTE BOTH WEAKEN THIS SYSTEM AFTER
SUNRISE AS OUTFLOW PUSHES SOUTH...WITH NEW CONVECTIVE DEVELOPMENT
ALONG OUTFLOW...WITH SOME INCREASE IN AREAL COVERAGE IN THE
AFTERNOON WITH DAYTIME HEATING. THINK THIS SCENARIO IS REASONABLE
AND WILL LEAN THAT WAY WITH THE FORECAST...BRINGING INCREASING
POPS THIS MORNING OVER NW ZONES...AND THEN INCREASING POPS MORE IN
THE AFTERNOON FOR SOUTHEAST SECTIONS. WILL GO WITH LIKELY POPS FOR
PEAK TIMES. MODEL TOTAL QPF FROM SYNOPTIC MODELS THROUGH THIS
EVENING LOOKING AT GFS AND EC VARIES FROM HALF AN INCH TO 1.5
INCHES. HRRR STORM TOTALS SHOW TYPICAL VARIABILTY WITH
CONVECTION...WITH ISOLD AMOUNTS 3 TO 4 INCHES. THINK MOST AREAS
WILL SEE AN INCH OR LESS BUT WILL HAVE POTENTIAL FOR THOSE LOCALLY
HIGHER 3 INCH AMOUNTS WHERE THE CELLS OCCUR. EVEN YDA WITH PULSE
STORMS HAD A FEW VERY ISOLD HIGHER TOTALS. IMPACT ON RIVERS AND
BAYOUS WHICH REACT MORE TO BASIN AVERAGE PRECIP SHOULD BE MINIMAL
UNLESS THE HEAVIER LOCAL RAINS FALL IN THOSE SMALLER MORE
SENSITIVE BASINS...OR OVER PLACES LIKE ADDICKS RESERVOIR. WILL
HAVE TO MONITOR CLOSELY. GIVEN THE SATURATED SOILS AND ELEVATED
FLOWS WILL KEEP FLASH FLOOD WATCH UP THROUGH TODAY FOR THOSE AREAS
THAT HAD THE MOST INTENSE RAINFALL.
COLD FRONT DROPS ACROSS THE AREA TOMORROW LIKELY BRINGING ANOTHER
BAND OF SHOWERS AND THUNDERSTORMS THROUGH. THINKING AGAIN LOOKING
AT ANOTHER INCH OR SO OF QPF ON AVERAGE WITH TWO DAY TOTALS OF 1
TO 3 INCHES ON AVERAGE BUT WITH LOCALLY HIGHER AMOUNTS. AFTER THIS
FRONT PUSHES SOUTH OF THE AREA THURSDAY NIGHT...WILL SEE DRIER AIR
FILTER INTO THE AREA FROM THE NORTH ON FRIDAY. SOME HINT IN GFS
AND EC OF SOME LINGERING SHOWERS AT THE COAST ON FRIDAY BEFORE
FRONT PUSHES OFF TO THE SOUTHEAST. LOOKS LIKE INCREASING AMOUNTS
OF SUN AND LOWER HUMIDITY FOR FRIDAY...FROM NORTH TO SOUTH THROUGH
THE DAY.
AFTER NICE DRY DAY ON SATURDAY START TO SEE RETURN FLOW OFF THE
GULF SATURDAY NIGHT. MODELS SHOWING WELL DEFINED UPPER DISTURBANCE
CROSSING THE AREA ON MONDAY...LIKELY BRINGING MORE SHOWERS AND
THUNDERSTORMS DURING THE SUNDAY AND MONDAY TIME FRAME. UPPER
DISTURBANCE PUSHES EAST FOR TUESDAY WITH LESSENING RAIN CHANCES
BUT REMAINING HUMID. SO...NOT A PROLONGED DRY PERIOD THAT WOULD
BE MORE IDEAL BUT REMAINING IN FAIRLY ACTIVE PATTERN AFTER A FEW
WELCOME RELATIVELY DRY DAYS FRIDAY AND SATURDAY. 46
MARINE...
LIGHT TO MODERATE ONSHORE WINDS ALONG WITH PERIODS OF SHOWERS AND
THUNDERSTORMS WILL PERSIST UNTIL LATE THURSDAY NIGHT OR EARLY FRIDAY
MORNING WHEN A COLD FRONT MOVES THROUGH THE AREA. LIGHT TO MODERATE
OFFSHORE WINDS BEHIND THE FRONT WILL PERSIST THROUGH EARLY SATURDAY.
LIGHT ONSHORE WINDS THAT RETURN TO THE AREA SATURDAY NIGHT AND
STRENGTHEN ON SUNDAY AND MONDAY ARE EXPECTED TO PERSIST THROUGH ALL
OF NEXT WEEK. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 79 67 77 57 79 / 60 30 50 30 10
HOUSTON (IAH) 79 67 80 64 81 / 60 40 70 40 10
GALVESTON (GLS) 75 70 76 69 76 / 60 40 50 30 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE FOLLOWING ZONES:
AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
LIBERTY...MONTGOMERY...POLK...SAN JACINTO...WALKER...
WALLER...WASHINGTON...WHARTON.
GM...NONE.
&&
$$
DISCUSSION...46
AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS AMARILLO TX
410 AM CDT WED APR 20 2016
.DISCUSSION...
TAKING ANOTHER LOOK AT THE LATEST HIGH-RES MODELS...THE HRRR IS NOW
BACKING OFF FROM THE DEVELOPMENT OF DENSE FOG ACROSS THE PANHANDLES
THIS MORNING. WILL LIKELY TO NEED TO CANCEL BUT WILL HOLD OFF UNTIL
CLOSER TO DAYBREAK TO SEE IF ANY DENSE FOG DEVELOPS. IF NOT...WILL
CANCEL BEFORE SHIFT CHANGE THIS MORNING. OTHERWISE...LOW CLOUDS WILL
PREVAIL THIS MORNING AS THE VIGOROUS CLOSED UPPER LOW OVER THE
CENTRAL PLAINS STATES ALLOWS FOR A VORT LOBE TO ROTATE NORTHWEST TO
SOUTHEAST ON THE BASAL OF THE UPPER TROUGH BY 00Z TO 06Z THURSDAY
ACROSS THE FORECAST AREA. CONVECTION SHOULD DEVELOP AFTER 20Z TO 22Z
TODAY...MAINLY OVER THE SOUTHERN HALF OF THE TEXAS PANHANDLE...WITH
THE SEVERE THREAT PRIMARILY ACROSS THE SOUTHEASTERN AND SOUTH CENTRAL
PORTIONS OF THE TEXAS PANHANDLE LATER TODAY AND TONIGHT. CONVECTION
SHOULD QUICKLY EXIT THE PANHANDLES BY 12Z THURSDAY AS AN UPPER RIDGE
BUILDS IN FROM THE WEST LATE THIS WEEK. WARMER AND DRIER CONDITIONS
EXPECTED THURSDAY THROUGH THE WEEKEND.
THE MEDIUM RANGE MODELS DIFFER WITH RESPECT TO THE NEXT CLOSED UPPER
LOW PROGGED TO MOVE OUT OF THE GREAT BASIN REGION THIS WEEKEND INTO
EARLY NEXT WEEK. THE ECMWF...WHICH WAS THE DRIER MODEL 24 HOURS
AGO...IS NOW FORECASTING AN OPEN WAVE TO TRACK NORTHEAST OUT OF BAJA
CALIFORNIA AND NORTHWEST MEXICO FRIDAY NIGHT AND SATURDAY INTO
SOUTHWEST TEXAS BY SATURDAY NIGHT AND SUNDAY. THE MAIN CLOSED UPPER
LOW IS FORECAST TO LIFT EAST AND NORTH OUT OF THE GREAT BASIN REGION
INTO THE CENTRAL ROCKIES AND NORTHERN PLAINS STATES BY EARLY NEXT
WEEK. THE ECMWF BREAKS OUT QPF SATURDAY AFTERNOON ACROSS THE
NORTHWESTERN PORTIONS OF THE FORECAST AREA SATURDAY AFTERNOON BUT
KEEPS THE REMAINDER OF THE WEEKEND AND EARLY NEXT WEEK DRY. THE GFS
IS COMPLETELY THE OPPOSITE OF 24 HOURS AGO AND IS NOW KEEPING THE
CLOSED UPPER LOW OVER THE NORTHERN STREAM RATHER THAN THE SOUTHERN
STREAM. THE GFS ALSO FORECASTS AN OPEN WAVE LIFTING NORTH AND EAST
OUT BAJA CALIFORNIA AND NORTHWESTERN/NORTHERN MEXICO...HOWEVER THE
GFS KEEPS THE QPF WELL SOUTH OF THE PANHANDLES AND...LIKE THE
ECMWF...MAINTAINS A DRY FORECAST THROUGH THE END OF THE WEEKEND INTO
EARLY NEXT WEEK. THEREFORE...OPTED TO REMOVE POPS FROM SUNDAY AND GO
WITH A DRY AND UNSEASONABLY WARM FORECAST THIS WEEKEND INTO EARLY
NEXT WEEK. BREEZY TO WINDY THIS WEEKEND AS A DEEPENING SURFACE TROUGH
DEVELOPS TO THE LEE OF THE ROCKIES WHICH WILL THEN TRACK EAST INTO
THE FORECAST AREA SUNDAY. A COLD FRONT IS FORECAST TO PUSH ACROSS THE
PANHANDLES EARLY NEXT WEEK WITH NO CONVECTION ASSOCIATED WITH THE
FRONT.
SCHNEIDER
&&
.FIRE WEATHER...
A DEEPENING SURFACE TROUGH OVER EASTERN COLORADO OR WESTERN KANSAS
SOUTHWARD TO NEAR THE TEXAS AND NEW MEXICO STATE LINE WILL TRACK
EAST INTO THE TEXAS AND OKLAHOMA PANHANDLES ON SUNDAY. INCREASING
DOWNSLOPING SOUTHWESTERLY 20 FOOT WINDS AND MINIMUM AFTERNOON
HUMIDITIES FALLING INTO THE 15 TO 20 PERCENT RANGE ACROSS MAINLY THE
WESTERN SECTIONS OF THE PANHANDLES COULD POSSIBLY RESULT IN ELEVATED
FIRE WEATHER CONDITIONS SUNDAY AFTERNOON INTO EARLY SUNDAY EVENING.
SCHNEIDER
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 69 45 72 45 77 / 20 50 5 0 5
BEAVER OK 68 44 73 43 79 / 20 20 5 0 5
BOISE CITY OK 65 39 71 41 77 / 30 30 5 0 5
BORGER TX 70 46 75 47 79 / 20 50 5 0 5
BOYS RANCH TX 72 43 74 44 79 / 20 40 5 0 5
CANYON TX 71 44 73 44 77 / 20 40 5 0 0
CLARENDON TX 68 48 73 47 77 / 20 70 10 0 5
DALHART TX 67 41 72 42 77 / 30 40 5 0 5
GUYMON OK 67 42 73 43 79 / 20 20 5 0 5
HEREFORD TX 73 45 73 44 77 / 20 30 5 0 0
LIPSCOMB TX 69 46 74 44 78 / 10 30 5 0 5
PAMPA TX 67 45 70 46 77 / 20 60 10 0 5
SHAMROCK TX 69 49 74 46 78 / 20 70 10 0 5
WELLINGTON TX 70 51 76 47 79 / 20 70 10 0 5
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 11 AM CDT THIS MORNING FOR THE
FOLLOWING ZONES: ARMSTRONG...CARSON...COLLINGSWORTH...
DALLAM...DEAF SMITH...DONLEY...GRAY...HANSFORD...HARTLEY...
HEMPHILL...HUTCHINSON...LIPSCOMB...MOORE...OCHILTREE...
OLDHAM...POTTER...RANDALL...ROBERTS...SHERMAN...WHEELER.
OK...DENSE FOG ADVISORY UNTIL 11 AM CDT THIS MORNING FOR THE
FOLLOWING ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
3/11
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
346 AM CDT WED APR 20 2016
.DISCUSSION...
LATEST RADAR COMPOSITES SHOW MCS WORKING ACROSS NORTH CENTRAL
TEXAS. IT HAS BECOME MORE EAST TO WEST ORIENTED OVERNIGHT.
MESOSCALE MODELS...ICLUDING TTU WRF AND HRRR VERIFYING FAIRLY WELL
ATTM. INTERESTING TO NOTE BOTH WEAKEN THIS SYSTEM AFTER SUNRISE AS
OUTFLOW PUSHES SOUTH...WITH NEW CONVECTIVE DEVELOPMENT ALONG
OUTFLOW...WITH SOME INCREASE IN AREAL COVERAGE IN THE AFTERNOON
WITH DAYTIME HEATING. THINK THIS SCENARIO IS REASONABLE AND WILL
LEAN THAT WAY WITH THE FORECAST...BRINGING INCREASING POPS THIS
MORNING OVER NW ZONES...AND THEN INCREASING POPS MORE IN THE
AFTERNOON FOR SOUTHEAST SECTIONS. WILL GO WITH LIKELY POPS FOR
PEAK TIMES. MODEL TOTAL QPF FROM SYNOPTIC MODELS THROUGH THIS
EVENING LOOKING AT GFS AND EC VARIES FROM HALF AN INCH TO 1.5
INCHES. HRRR STORM TOTALS SHOW TYPICAL VARIABILTY WITH
CONVECTION...WITH ISOLD AMOUNTS 3 TO 4 INCHES. THINK MOST AREAS
WILL SEE AN INCH OR LESS BUT WILL HAVE POTENTIAL FOR THOSE LOCALLY
HIGHER 3 INCH AMOUNTS WHERE THE CELLS OCCUR. EVEN YDA WITH PULSE
STORMS HAD A FEW VERY ISOLD HIGHER TOTALS. IMPACT ON RIVERS AND
BAYOUS WHICH REACT MORE TO BASIN AVERAGE PRECIP SHOULD BE MINIMAL
UNLESS THE HEAVIER LOCAL RAINS FALL IN THOSE SMALLER MORE
SENSITIVE BASINS...OR OVER PLACES LIKE ADDICKS RESEVOIR. WILL HAVE
TO MONITOR CLOSELY. GIVEN THE SATURATED SOILS AND ELEVATED FLOWS
WILL KEEP FLASH FLOOD WATCH UP THROUGH TODAY FOR THOSE AREAS THAT
HAD THE MOST INTENSE RAINFALL.
COLD FRONT DROPS ACROSS THE AREA TOMORROW LIKELY BRINGING ANOTHER
BAND OF SHOWERS AND THUNDERSTORMS THROUGH. THINKING AGAIN LOOKING
AT ANOTHER INCH OR SO OF QPF ON AVERAGE WITH TWO DAY TOTALS OF 1
TO 3 INCHES ON AVERAGE BUT WITH LOCALLY HIGHER AMOUNTS. AFTER THIS
FRONT PUSHES SOUTH OF THE AREA THURSDAY NIGHT...WILL SEE DRIER AIR
FILTER INTO THE AREA FROM THE NORTH ON FRIDAY. SOME HINT IN GFS
AND EC OF SOME LINGERING SHOWERS AT THE COAST ON FRIDAY BEFORE
FRONT PUSHES OFF TO THE SOUTHEAST. LOOKS LIKE INCREASING AMOUNTS
OF SUN AND LOWER HUMIDITY FOR FRIDAY...FROM NORTH TO SOUTH THROUGH
THE DAY.
AFTER NICE DRY DAY ON SATURDAY START TO SEE RETURN FLOW OFF THE
GULF SATURDAY NIGHT. MODELS SHOWING WELL DEFINED UPPER DISTURBANCE
CROSSING THE AREA ON MONDAY...LIKELY BRINGING MORE SHOWERS AND
THUNDERSTORMS DURING THE SUNDAY AND MONDAY TIME FRAME. UPPER
DISTURBANCE PUSHES EAST FOR TUESDAY WITH LESSENING RAIN CHANCES
BUT REMAINING HUMID. SO...NOT A PROLONGUED DRY PERIOD THAT WOULD
BE MORE IDEAL BUT REMAINING IN FAIRLY ACTIVE PATTERN AFTER A FEW
WELCOME RELATIVELY DRY DAYS FRIDAY AND SATURDAY. 46
&&
.MARINE...
LIGHT TO MODERATE ONSHORE WINDS ALONG WITH PERIODS OF SHOWERS AND
THUNDERSTORMS WILL PERSIST UNTIL LATE THURSDAY NIGHT OR EARLY FRIDAY
MORNING WHEN A COLD FRONT MOVES THROUGH THE AREA. LIGHT TO MODERATE
OFFSHORE WINDS BEHIND THE FRONT WILL PERSIST THROUGH EARLY SATURDAY.
LIGHT ONSHORE WINDS THAT RETURN TO THE AREA SATURDAY NIGHT AND
STRENGTHEN ON SUNDAY AND MONDAY ARE EXPECTED TO PERSIST THROUGH ALL
OF NEXT WEEK. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 78 67 79 60 79 / 70 30 60 30 10
HOUSTON (IAH) 78 67 81 64 81 / 70 40 70 30 10
GALVESTON (GLS) 77 70 79 68 78 / 50 50 60 30 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE FOLLOWING ZONES:
AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
LIBERTY...MONTGOMERY...POLK...SAN JACINTO...WALKER...
WALLER...WASHINGTON...WHARTON.
GM...NONE.
&&
$$
PLEASE SEE THE 00Z AVIATION FORECAST DISCUSSION BELOW.
AVIATION...
VFR CONDITIONS ARE CURRENTLY IN PLACE ACROSS THE REGION. WITH
CONTINUED COOLING IN THE MOIST LOW-LEVELS...CIGS WILL LOWER INTO
MVFR BETWEEN 02Z-05Z. CONTINUED COOLING AND DECREASING OF WINDS
SHOULD DROP CIGS INTO IFR BEGINNING 06Z-08Z. IFR CIGS WILL CONTINUE
UNTIL LATE MORNING. WE COULD ALSO SEE SOME CONVECTION MOVE IN FROM
THE NORTHWEST EARLY WEDNESDAY MORNING. WE/LL MAINTAIN PROB30
GROUPS AT ALL SITES FOR NOW...BUT IT APPEARS KAUS MIGHT STAND A
BETTER CHANCE THAN OUR OTHER TAF SITES. CIGS WILL BE SLOW TO RISE
TOMORROW...ESPECIALLY IF THUNDERSTORM ACTIVITY LEAVES LIGHT
STRATIFORM RAIN IN IT/S WAKE.
PREV DISCUSSION... /ISSUED 304 PM CDT TUE APR 19 2016/
SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...
AT 245PM...VISIBLE SATELLITE SHOWED CONVECTIVE INITIATION
BEGINNING OFF THE MEXICAN MOUNTAINS AND UP THROUGH THE BIG BEND
AREA. FARTHER EAST INTO OUR CWA...STRATUS WAS JUST BEGINNING TO
DETERIORATE WHICH HAS BEEN LIMITING THE CONVECTIVE POTENTIAL.
HOWEVER STILL WITH A FEW HOURS OF HEATING LEFT IN THE DAY...A
SLIGHT CHANCE OF STRONG TO SEVERE THUNDERSTORMS COULD BE POSSIBLE
FOR THE WESTERN PLATEAU COUNTIES...LIKE VAL VERDE. LOW LEVEL LAPSE
RATES ON THE PLATEAU ARE SUB 6 DEG/KM PER THE RAP HOWEVER AND WITH
SUPERCELL STORM MOTION VECTORS WEST OF THE RIO GRANDE PARALLEL TO
THE RIVER AND APPRECIABLE CONVECTION INHIBITION FARTHER
EAST...CONFIDENCE IS LOW ON STORMS IN OUR CWA THIS EVENING.
HOWEVER...SHOULD SOME CELLS MAKE IT INTO THE CWA...ENOUGH
INSTABILITY MAY BE GENERATED BY LATE THIS AFTERNOON TO WARRANT A
MARGINALLY SEVERE HAIL THREAT.
THIS CONVECTION FARTHER WEST AND NORTH IS BEING PRETTY WELL
HANDLED IN THE HI RESOLUTION MODELS THIS AFTERNOON AND THEY ARE
INDICATING CONGLOMERATING INTO A QUASI LINEAR SYSTEM OR BROKEN
LINE OF MULTI CELLS PUSHING SOUTHEAST INTO THE NORTHERN CWA BY
EARLY TOMORROW MORNING. MORE SPECIFICALLY THE 4AM-10AM TIME FRAME.
THE LINE SHOULD BE ABLE TO PASS THROUGH AT A DECENT
SPEED...ENOUGH TO TYPICALLY NOT BE MUCH OF A CONCERN FOR FLASH
FLOODING. IN FACT...PWATS AT 12Z ARE ONLY IN THE 1.4 INCH RANGE IN
THE AUSTIN AREA. SO IT LOOKS LIKE QPF WISE...THAT GENERALLY AROUND
AN INCH OR SO WILL RESULT FROM THE PASSAGE OF THIS LINE.
HOWEVER...WHILE ISOLATED...THERE MAY BE SOME SPOTS THAT GET 3
INCHES OR SO WHICH WOULD BE QUITE PROBLEMATIC FOR COUNTIES IN THE
EAST WHICH RECEIVED OVER 8 INCHES OF RAIN FROM YESTERDAY.
THEREFORE THE DECISION TO MAINTAIN A FFA EAST OF I35 WAS MADE FOR
THOSE HIGHLY VULNERABLE ANTECEDENT COUNTIES SPECIFICALLY...WHILE
OTHER COUNTIES SHOULD BE ABLE TO HANDLE THE RAINFALL.
LONG TERM (THURSDAY THROUGH TUESDAY)...
THE BIG UPPER LOW OVER THE ROCKIES RESPONSIBLE FOR ALL OF OUR RAIN
ACTIVITY LATELY WILL BEGIN TO FINALLY SHIFT EASTWARD THURSDAY AND
PROGRESS ACROSS THE CENTRAL UNITED STATES. THIS SHOULD QUICKLY
TRANSITION THE UPPER LEVEL PATTERN FOR THE REGION INTO A NORTHWEST
FLOW SITUATION. ANOTHER SHORTWAVE WILL PASS INTO THE RED RIVER
VALLEY AND INTO THE ARKLATEX THURSDAY AS WELL. THIS WILL BRING
ANOTHER SHOT AT SHOWERS AND STORMS THURSDAY AFTERNOON AND EVENING
FAVORING THE NORTHERN AND EASTERN ZONES YET AGAIN.
A COLD FRONT WILL PUSH THROUGH THE AREA LATE THURSDAY NIGHT BEHIND
THE QPF REPLACING THE AIR MASS WITH MUCH DRIER AIR FRIDAY. A BRIEF
DRY PERIOD WILL EXIST THROUGH SATURDAY AFTERNOON WHEN A WEAK
SHORTWAVE COMES ACROSS THE STATE THIS WEEKEND WITH THE NEXT POP
OPPORTUNITY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 65 79 60 79 58 / 30 40 20 - 0
AUSTIN BERGSTROM INTL AIRPORT 64 79 59 79 56 / 30 40 20 - 0
NEW BRAUNFELS MUNI AIRPORT 64 80 61 80 58 / 30 40 30 10 0
BURNET MUNI AIRPORT 62 78 57 77 56 / 30 40 20 - 0
DEL RIO INTL AIRPORT 66 85 62 82 63 / 20 20 20 20 10
GEORGETOWN MUNI AIRPORT 63 78 58 78 56 / 30 40 20 - 0
HONDO MUNI AIRPORT 65 84 61 80 59 / 30 40 20 20 -
SAN MARCOS MUNI AIRPORT 65 79 60 79 57 / 30 40 30 - 0
LA GRANGE - FAYETTE REGIONAL 65 79 61 79 58 / 30 50 30 10 0
SAN ANTONIO INTL AIRPORT 66 81 63 80 60 / 30 40 20 10 0
STINSON MUNI AIRPORT 67 82 63 81 61 / 30 40 20 10 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR THE FOLLOWING
COUNTIES: BASTROP...CALDWELL...DE WITT...FAYETTE...GONZALES...
LAVACA...LEE.
&&
$$
MESOSCALE/AVIATION...HAMPSHIRE
SYNOPTIC/GRIDS...04
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1145 PM CDT TUE APR 19 2016
.AVIATION...
SINKING MOTION ACROSS TAFS SO FAR TONIGHT BEHIND THE CONVECTIVE
SYSTEM ALONG A COLD FRONT NOW SOUTH OF THE AREA. LOW LEVEL FLOW
ALSO DIVERGENT...BUT EXPECTED TO TURN MORE NORTHEAST TO EASTERLY
LATER TONIGHT. LOWER ATMOSPHERE QUITE MOIST SO SHOULD NOT BE
DIFFICULT TO SATURATE...ESPECIALLY WITH A MORE PRONOUNCED UPSLOPE
COMPONENT AT BOTH KPVW AND KLBB. CURRENT EXPECTATIONS ARE FOR LIFR
CEILINGS DEVELOPING AND POSSIBLE WE COULD SEE AT LEAST A BRIEF
PERIOD OF VERY LOW VISIBILITIES BUT CANNOT STATE WITH MUCH
CONFIDENCE JUST WHEN THAT MAY OCCUR. BUT SOMETHING TO WATCH FOR
LATER. LOW CEILINGS LIKELY TO HOLD THROUGH WEDNESDAY MORNING AND
MAY ONCE MORE SEE PATCHY DRIZZLE AT SOME POINT. THEN CEILINGS
SHOULD BEGIN LIFTING LATE WEDNESDAY MORNING INTO THE AFTERNOON TO
MVFR LEVELS AND SCATTERING OUT BOTH KLBB AND KPVW BUT MAY HOLD
AT KCDS MUCH OF THE DAY. ANOTHER UPPER TROUGH WILL DRIVE SOUTHEAST
FROM COLORADO ACROSS THE TEXAS PANHANDLE WEDNESDAY EVENING
SPREADING THUNDER CHANCES ESPECIALLY TOWARDS KCDS WHERE INITIAL
PROB30 HAS BEEN INSERTED. THUNDER CHANCES ALSO KPVW AND KLBB
MAINLY LATER TOMORROW NIGHT. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 651 PM CDT TUE APR 19 2016/
AVIATION...
IN SIMILAR FASHION TO THIS MORNING...VFR CONDITIONS ARE LIKELY TO
CRATER TO IFR AT PVW AND LBB AFTER MIDNIGHT AS THE LOWER
ATMOSPHERE REMAINS VERY MOIST. COULD SEE DENSE FOG ALSO DEVELOP
THOUGH THIS IS LESS LIKELY COMPARED TO JUST VERY LOW STRATUS.
CONFIDENCE IN IFR AT CDS IS LESS CERTAIN AS SOME MODELS ARE
RELUCTANT TO REDEVELOP LOW CLOUDS...BUT HAVE HINTED AT THIS
SCENARIO WITH A SCATTERED LOW LAYER.
SHOULD SEE VFR RETURN TO LBB AND PVW BY THE AFTN AT WHICH POINT A
REPEAT OF AFTERNOON TS ARE POSSIBLE SOUTH OF AN UPPER LOW...MAINLY
N OF LBB.
PREV DISCUSSION... /ISSUED 318 PM CDT TUE APR 19 2016/
SHORT TERM...
PRECIP CHANCES WILL CONTINUE TO BE THE FOCUS TONIGHT AND AGAIN
WEDNESDAY. ONGOING SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS
BEGINNING TO MARCH EWD ACROSS THE NRN HALF OF THE FCST AREA AT A
PRETTY GOOD CLIP. THE SOURCE REGION FOR CONVECTIVE REDEVELOPMENT
THAT HAD BEEN ANCHORED IN ERN NM IS SHIFTING TO THE WRN SOUTH
PLAINS. THIS ADJUSTMENT OCCURRING IN RESPONSE TO THE MAIN UPPER
TROUGH OVER NRN NM SHOWING EWD MOVEMENT PER WATER VAPOR IMAGERY
THE LAST COUPLE HOURS. TROUGH AXIS SHOULD SHIFT TO THE EAST OF THE
FCST AREA AROUND 06Z WITH HIGH CHANCE TO LIKELY POPS ERN HALF OF
THE FCST AREA APPROPRIATE UNTIL THEN. COULD ALSO SEE A SHIFT SWD
WITH THE CONVECTION AS OUTFLOW INTERACTS WITH LOW LEVEL MOISTURE
SRN SOUTH AND ROLLING PLAINS PER HRRR OUTPUT.
FOCUS THEN SHIFTS TO PRECIP CHANCE WEDNESDAY. APPEARS A DECENTLY
DEFINED DRYLINE WILL SHIFT INTO THE WRN ZONES DURING THE AFTN. LOW
LEVEL MOISTURE TO REMAIN IN PLACE TO ITS EAST WITH SFC DEW POINT
TEMPS UPPER 40S-LOWER 50S. NOT MUCH UPPER SUPPORT EVIDENT WITH A
SHORT WAVE TROUGH PROGGED TO SEWD THROUGH THE MEAN FLOW FROM SRN
COLORADO TWD THE PANHANDLE. WEAKLY FORCED CONVECTIVE INITIATION
POSSIBLE LATE AFTN JUST EAST OF THE DRYLINE GENERALLY ALONG I-27.
ONLY OTHER ISSUE IS CHANCE FOR FOG AROUND SUNRISE. COOL...MOIST AIR
MASS WITH UPSLOPE EASTERLY LOW LEVEL FLOW POINT TO THE POSSIBILITY.
NO CONSENSUS FROM GUIDANCE ATTM. WILL KEEP MENTION OUT FOR NOW
AND LET NEXT SHIFT REEVALUATE.
LONG TERM...
A SECONDARY COLD FRONT WILL PUSH THROUGH TOMORROW NIGHT AS A SHORT
WAVE ROTATES AROUND THE BACKSIDE OF THE MUCH LARGER UPPER LEVEL LOW
ACROSS THE MIDWEST. WITH PLENTY OF MOISTURE IN PLACE AS WELL AS LIFT
FROM THE SHORTWAVE A COMPLEX OF SHOWERS AND THUNDERSTORMS WILL BE
HIGHLY POSSIBLE ACROSS THE EASTERN TX PANHANDLE AND ROLLING PLAINS.
WHILE SOME HEAVY RAIN WILL BE POSSIBLE AS PWATS WILL BE OVER 1 INCH
THE COMPLEX SHOULD MOVE QUICK ENOUGH TO HELP MITIGATE FLOODING
CONCERNS. WINDS WILL REMAIN OUT OF THE NORTHEAST INTO LATE THURSDAY
NIGHT WHICH WILL HELP KEEP TEMPS INTO THE LOW 70S. WINDS WILL TURN
BACK TO THE SOUTH/SOUTHEAST BY EARLY FRIDAY AFTERNOON AS A LEE TROF
DEVELOPS. THIS...IN ADDITION TO AN UPPER RIDGE MOVING OVER THE
REGION...WILL ALLOW TEMPS TO WARM BACK TO NEAR AVERAGE FRIDAY. TEMPS
WILL CONTINUE TO WARM TO SEVERAL DEGREES ABOVE AVERAGE BY SUNDAY AS
WINDS WILL CONTINUOUSLY STAY OUT OF THE SOUTH TO SOUTHWEST. THE LEE
TROF WILL PUSH SOUTHWARD STARTING LATE SUNDAY MORNING ALLOWING A
DRYLINE TO PUSH EASTWARD FROM NM. A SMALL CHANCE EXISTS FOR ISOLATED
THUNDERSTORMS ALONG THE DRYLINE...MOSTLY OVER THE ROLLING
PLAINS...SUNDAY BUT WILL BE DEPENDENT ON THE TIMING OF A PASSING
SHORTWAVE. WINDS WILL BE FAIRLY BREEZY...SPECIFICALLY ACROSS OUR
NORTHWESTERN COUNTIES...BEHIND THE DRYLINE AS THE MID TO LOWER
LEVELS DRY AND THERMAL PROFILES BECOME SUPER ADIABATIC. CONDITIONS
BEYOND LATE SUNDAY BECOME QUESTIONABLE AS MODELS BEGIN TO DIVERGE
WITH THE UPPER LEVEL PATTERN. THE ECMWF BRINGS AN UPPER LEVEL LOW
CLOSE TO THE REGION BY MONDAY AFTERNOON/EVENING WHICH WOULD ALLOW
WINDS TO KEEP BLOWING WHILE THE GFS TAKES A MORE PACIFIST ROLE BY
KEEPING FLOW MOSTLY ZONAL AND DELAYING THE APPROACH OF THE LOW UNTIL
EARLY WEDNESDAY. EITHER WAY THE FORECAST LOOKS TO REMAIN DRY.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/05
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
648 PM CDT THU APR 21 2016
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 344 PM CDT THU APR 21 2016
AT 3 PM...SCATTERED SHOWERS WERE FOUND ACROSS CLARK COUNTY IN
NORTH-CENTRAL WISCONSIN AND NORTHEAST IOWA. BOTH OF THESE WERE
LOCATED ALONG A BAND OF 900 TO 800 MB FRONTOGENESIS. THERE WERE
REPORTS OF A WALL CLOUD AND PEA SIZE HAIL IN DAVENPORT/S FORECAST
AREA. THIS WAS OCCURRING IN AN AREA WHERE THE RAP WAS HIGHLIGHTING
THE NON SUPERCELL TORNADO PARAMETER /NST/. THROUGH 21.23Z...THE
RAP IS HIGHLIGHTING ANOTHER AREA OF NST ACROSS NORTHEAST IOWA AND
SOUTHWEST WISCONSIN. THERE IS A STATIONARY BOUNDARY IN THIS AREA.
HOWEVER THE RAP IS 5 TO 8F TOO HIGH WITH ITS SURFACE DEW
POINTS...THEREFORE...ITS CAPES ARE TOO HIGH. THIS IS LIKELY
ENHANCING THE NST VALUE TOO MUCH.
FOR THIS EVENING...THE 21.12Z AND 21.18Z MODELS CONTINUE TO SHOW
THAT BOTH OF THE 900 TO 800 MB FRONTOGENESIS BANDS WILL SLOWLY
MOVE SOUTHEAST AND WEAKEN. AT THE SAME TIME...THE SURFACE BASED
CAPES AND 900 TO 850 MB LAPSE RATES WILL BE WEAKENING. AS THIS
OCCURS...THE SHOWERS WILL RAPIDLY DISSIPATE BETWEEN 22.03Z AND
22.06Z.
ON FRIDAY MORNING...TEMPERATURES WILL DROP INTO THE MID-30S IN
TAYLOR COUNTY. WHILE THE TEMPERATURES WILL BE COOL FOR THE
POTENTIAL OF SCATTERED FROST...THERE WILL STILL BE A 2 TO 3F
TEMPERATURE-DEW POINT DEPRESSIONS AND THE SURFACE WINDS WILL BE IN
THE 5 TO 10 MPH RANGE. THIS SHOULD DETER THE DEVELOPMENT OF FROST
IN THAT AREA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 344 PM CDT THU APR 21 2016
ON FRIDAY NIGHT THERE WILL BE MOSTLY CLEAR SKIES AND LIGHT WINDS.
THIS WILL ALLOW THE LOW TEMPERATURES TO FALL INTO THE MID 30S IN
CENTRAL WISCONSIN. THIS MAY RESULT IN SOME PATCHY FROST IN THIS
AREA. WE WILL HAVE TO WATCH THIS AREA CLOSELY FOR A POTENTIAL
FROST ADVISORY.
FROM SATURDAY NIGHT THROUGH MONDAY...AN UPPER LEVEL LOW WILL MOVE
SOUTHEAST THROUGH THE REGION. ON SUNDAY AFTERNOON...THE 0-4 KM
CAPES WILL CLIMB UP TO 750 J/KG SOUTH OF INTERSTATE 90 CORRIDOR
AND THE 0-6 KM SHEAR WILL CLIMB UP TO 45 KNOTS. THIS MAY RESULT IN
THE DEVELOPMENT OF A FEW SUPERCELLS AHEAD OF THE COLD FRONT IN
NORTHEAST IOWA. WE WILL HAVE TO WATCH THIS PERIOD CLOSELY.
FROM TUESDAY NIGHT INTO WEDNESDAY...ANOTHER UPPER LEVEL LOW WILL
MOVE SOUTHEAST THROUGH THE REGION. THERE CONTINUES TO BE DEEP
SHEAR LOCATED SOUTH OF INTERSTATE 94. HOWEVER THE CAPES ARE ONLY
UP TO 500 J/KG. THIS CAPE WILL BE A LIMITING FACTOR FOR ANY THREAT
OF SEVERE WEATHER.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 647 PM CDT THU APR 21 2016
MVFR TO VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL TAPER OFF THIS
EVENING WITH THE LOSS OF DAYTIME HEATING. A COLD FRONT WILL PUSH
THROUGH THE TAF SITES OVERNIGHT WITH A PERIOD OF MVFR STRATUS
EXPECTED IN ITS WAKE. HIGH PRESSURE BUILDS INTO THE REGION FRIDAY
AFTERNOON WITH VFR CONDITIONS EXPECTED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
241 AM PDT FRI APR 22 2016
.SYNOPSIS...
A LOW PRESSURE TROUGH WILL MOVE THROUGH NORTHERN CALIFORNIA TODAY
AND TONIGHT. IT WILL BRING COOLER WEATHER, MORE CLOUDS, STRONG
WINDS IN THE MOUNTAINS AND DESERTS, AS WELL AS A SLIGHT CHANCE OF
LIGHT SHOWERS TONIGHT. THE WEEKEND WILL CONTINUE RELATIVELY COOL,
BUT SEASONAL. ON SUNDAY NIGHT AND MONDAY ANOTHER TROUGH OF LOW
PRESSURE WILL MOVE THROUGH CALIFORNIA AND BRING A SMALL CHANCE OF
SHOWERS AND GUSTY WINDS. ANOTHER POSSIBILITY OF RAIN ARRIVES
THURSDAY.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
LOW CLOUDS ARE TRYING TO FORM, BUT ARE STRUGGLING SOMEWHAT TO GAIN
MUCH TRACTION THIS MORNING. PARTLY CLOUDY SKIES WILL PREVAIL TODAY
AND IT WILL BE MUCH COOLER. A TROUGH OF LOW PRESSURE WILL MOVE
THROUGH NORTHERN CALIFORNIA TODAY AND TONIGHT. IT WILL BRING US MORE
CLOUDS TONIGHT LEADING TO VERY ISOLATED LIGHT SHOWERS WEST OF THE
MOUNTAINS. STRONG WINDS WILL BE A BIGGER PLAYER FOR THE MOUNTAINS
AND DESERTS. TOP GUSTS IN THE LEE OF MOUNTAINS AND GAPS WILL
EXCEED 55 MPH, SO A WIND ADVISORY IS IN PLACE. THIS TROUGH MOVES
OUT SATURDAY, BUT NOT A LOT OF HIGH PRESSURE FOLLOWS SO THE
WEEKEND WILL STAY FAIRLY COOL. THE NEXT TROUGH TRACKS DOWN THE
COAST AND THROUGH CALIFORNIA SUNDAY NIGHT AND MONDAY. THIS HAS
MORE COLD AIR AND ENERGY, BUT LACKS IN MOISTURE. THE CHANCE OF
SHOWERS IS SMALL, BUT THERE WILL BE STRONG WINDS AGAIN IN THE
MOUNTAINS AND DESERTS. TUESDAY AND WEDNESDAY LOOK FAIR AND
SEASONAL BEFORE THE NEXT, THIRD TROUGH ARRIVES THURSDAY.
CONFIDENCE IS LOWER ABOUT THE TIMING AND INTENSITY OF THIS SYSTEM,
BUT SMALL CHANCES ARE IN THE FORECAST. THE COMING WEEK LOOKS
SEASONAL FOR TEMPERATURES WITH A FEW EPISODES OF GUSTY WINDS AND A
FEW SHOWERS.
&&
.AVIATION...
220930Z...COAST/VALLEYS...AREAS OF LOW CLOUDS NEAR THE COAST WITH
BASES 700-1200 FT MSL SPREADING ABOUT 10 SM INLAND THROUGH 15Z
TODAY. LOCAL VIS 3-5 MI IN FOG ON THE MESAS AND IN THE VALLEYS.
BASES RISING A FEW HUNDRED FEET AFTER 12Z. LOW CLOUDS AND FOG
DISSIPATING BY MID-MORNING. BKN-OVC CIGS RETURNING TO COASTAL TAF
SITES AFTER 02Z SAT WITH BASES AROUND 2000 FT.
MOUNTAINS/DESERTS...INCREASING WEST WINDS TODAY WITH SURFACE GUSTS
30-40 KT POSSIBLE AFTER 18Z WILL PRODUCE MODERATE UP/DOWN DRAFTS
AND LLWS OVER AND EAST OF THE MOUNTAINS.
&&
.MARINE...
230 AM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH THIS
MORNING. GUSTY NORTHWEST WINDS OF 15-20 KT THIS AFTERNOON THROUGH
SATURDAY NIGHT WITH GUSTS FROM 20-25 KT AS A LOW PRESSURE TROUGH
MOVES THROUGH CENTRAL CA. CONTINUED BREEZY SATURDAY.
SUNDAY THROUGH TUESDAY MORNING, A LARGE NORTHWEST SWELL OF 9-12 FEET
AT 9-11 SECONDS FROM 290 DEGREES WILL MOVE INTO THE COASTAL WATERS.
THIS WILL COMBINE WITH STRONGER NORTHWEST WINDS THAT GUSTING 25-30
KT AS A SECOND TROUGH OF LOW PRESSURE MOVES ACROSS THE REGION. THE
STRONG WINDS AND NORTHWEST SWELL WILL CREATE COMBINED SEAS OF 9 TO
12 FEET, RESULTING IN CONDITIONS HAZARDOUS TO SMALL CRAFT. A SMALL
CRAFT ADVISORY WILL BE IN EFFECT FRIDAY AFTERNOON THROUGH TUESDAY
MORNING.
&&
.BEACHES...
230 AM...WAVE MODELS INDICATE A NW SWELL OF 10-13 FT AT ABOUT 9
SECONDS WILL MOVE INTO THE SOUTHERN CA BIGHT MON AND TUE. THIS SWELL
COULD RESULT IN ELEVATED SURF OF AROUND 6 FT WITH HIGHER SETS ON
EXPOSED WEST-FACING BEACHES...ALONG WITH STRONG RIP CURRENTS.
A LARGE NORTHWEST SWELL FROM 290 DEGREES WILL RESULT IN
ELEVATED SURF OF 3 TO 6 FEET WITH HIGHER SETS POSSIBLE. STRONG RIP
CURRENTS TUESDAY.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...WIND ADVISORY FROM 5 PM THIS AFTERNOON TO 5 AM PDT SATURDAY FOR
APPLE AND LUCERNE VALLEYS-COACHELLA VALLEY-RIVERSIDE COUNTY
MOUNTAINS-SAN BERNARDINO COUNTY MOUNTAINS-SAN DIEGO COUNTY
DESERTS-SAN DIEGO COUNTY MOUNTAINS-SAN GORGONIO PASS NEAR
BANNING.
PZ...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 11 AM PDT
TUESDAY FOR COASTAL WATERS FROM SAN MATEO POINT TO THE
MEXICAN BORDER AND OUT TO 30 NM-WATERS FROM SAN MATEO POINT
TO THE MEXICAN BORDER EXTENDING 30 TO 60 NM OUT INCLUDING
SAN CLEMENTE ISLAND.
&&
$$
PUBLIC...MM
AVIATION/MARINE/BEACHES...PG
[top]
Area Forecast Discussion
National Weather Service Reno NV
238 AM PDT FRI APR 22 2016
SYNOPSIS...
A potent Pacific storm will move through the region today. Strong
and gusty winds can be expected along with valley rain and
mountain snow. A brief break is expected Saturday before a series
of systems is expected next week. Showery conditions are expected
Sunday afternoon and beyond along with cool temperatures.
&&
.SHORT TERM...
Moderate spring storm (by Sierra standards) with a strong cold
front is currently moving on shore and will impact the Sierra and
western Nevada today. No major changes were made to the forecast
with all winter weather and wind advisories still on track today.
Travel over Sierra passes today will very likely be impacted by
winter driving conditions so plan accordingly.
Current radar shows the leading edge of the strong cold front
currently moving into northern California. Instability ahead of
the front is currently creating some convective showers along the
Sierra crest around Donner Summit with off and on light showers
remaining possible until the cold front arrives. Precipitation may
start out as rain but is expected to change over to snow
relatively quickly above 7000 feet. HRRR model solutions show the
leading edge of the main cold front and heavy precipitation will
impact the Sierra around 10-11 am today with passes in the
northern Sierra (Yuba and Fredonyer) receiving heavy precipitation
as early as 7-8 am. For more details on snow amounts and timing
see the winter weather advisories.
Precipitation is expected to quickly spill into the lee of the
Sierra due to very unstable environment along the cold front and
strong upper level jet support. This will lead to periods of
brief moderate precipitation in western Nevada valleys. The
convective nature of this system will lead to wide disparities in
rain and snow amounts from one place to another depending on where
convective bands set up. There will also be the chance for a few
isolated thunderstorms today as the front quickly moves into
western Nevada.
Winds are expected to be quite strong today in western Nevada as
surface gradients tighten and instability will allow strong 700
mb winds to mix to the surface. Widespread winds of 25-35 mph
should be expected with peaks gusts of 50 mph and up to 60 mph in
wind prone areas. This could create some localized areas of
blowing dust which even if brief can cause hazardous driving
conditions.
This system is quite progressive with the cold front expected to
move into Utah by late Friday night. A few showers may linger
along the Sierra crest but the precipitation should be over by
Saturday morning. Brief shortwave ridging on Saturday will be
replaced by another trough digging into the area on Sunday. This
could bring another round of cold air and precipitation on Sunday
into Monday. Zach
.LONG TERM...Monday through Thursday...
Unsettled weather pattern is expected to continue through next week
as late season storm systems line up to move into the West Coast.
There is good agreement in the models that cold low pressure will
remain over the Great Basin on Monday with additional showers and
convective precipitation bands due to unstable conditions.
There is a possibility that we could see snow levels dropping to
near 4500 feet on Monday morning as the coldest air is expected to
move over the Sierra and western NV. Forecast confidence on seeing
snow to the valley floors is low, although there is a chance we
could see light slushy accumulations in the valleys and foothills of
western NV. Models have trended further east into central and
northeastern NV with the heaviest bands, but we will need to keep a
close eye on how this evolves over the next couple days as it has
potential to affect the Monday morning commute. High temperatures on
Monday will struggle to get out of the 40s in western NV and 30s in
the Sierra due to the low pressure overhead and abundant cloud
cover/showers. Low pressure will move out of the area Tuesday with
warming temperatures and clearing skies.
By Wednesday, another low pressure system is expected to move
into northern CA/NV bringing additional chances for showers and
increasing clouds. There is much uncertainty for the Wednesday-
Thursday timeframe regarding precipitation amounts, although this
system doesn`t look to be quite as cold as the the Monday system.
Hoon
&&
.AVIATION...
Multiple weather-related impacts to aviation are expected through
tonight as potent low pressure moves across the region.
Winds will be the primary impact today with wind shear potential,
mainly at KRNO-KCXP-KMMH as winds above the surface increase.
Widespread turbulent conditions are likely through today with peak
gusts up to 45 kt in the lower elevations and Sierra ridge gusts
near 80 kt.
Rain and snow will reach the northern Sierra early this morning,
then spread into western Nevada by this afternoon. Snow levels
should fall to 6000-7000 feet by this afternoon, which may bring IFR
conditions to KTRK, KTVL and KMMH. Snow accumulations on paved
surfaces are unlikely during the day, but some light accumulations
up to 2 inches are possible with the back edge of the snow moving
through this evening. For the western Nevada terminals including
KRNO and KCXP, precipitation will be all rain with reduced ceilings
for MVFR conditions this afternoon-evening. MJD/Hoon
&&
.REV Watches/Warnings/Advisories...
NV...Lake Wind Advisory until 8 AM PDT this morning for Lake Tahoe in
NVZ002.
Winter Weather Advisory from 8 AM this morning to 11 PM PDT this
evening NVZ002.
Wind Advisory from 11 AM this morning to 8 PM PDT this evening
NVZ001-004.
Wind Advisory until 5 PM PDT this afternoon NVZ003.
CA...Winter Weather Advisory from 5 AM early this morning to 5 PM PDT
this afternoon above 5500 feet in CAZ071.
Wind Advisory from 5 AM early this morning to 8 PM PDT this
evening CAZ073.
Lake Wind Advisory until 8 AM PDT this morning for Lake Tahoe in
CAZ072.
Winter Weather Advisory from 8 AM this morning to 11 PM PDT this
evening CAZ072.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
131 AM EDT FRI APR 22 2016
.SYNOPSIS...
SURFACE HIGH PRESSURE OFF THE COAST WILL CIRCULATE A MOIST
SOUTHERLY FLOW INTO THE FORECAST AREA AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT WILL CROSS THE AREA FRIDAY NIGHT. SHOWERS AND
THUNDERSTORMS ARE EXPECTED AHEAD OF THE FRONT FRIDAY. DRY HIGH
PRESSURE WILL BUILD INTO THE REGION LATE SATURDAY THROUGH TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MOISTURE WILL BE ON THE INCREASE IN THE SOUTHERLY FLOW WELL AHEAD
OF THE COLD FRONT TONIGHT. RADAR TRENDS AND THE HRRR SUPPORT
SCATTERED SHOWERS IN THE FORECAST AREA MAINLY AFTER 200 AM.
OBSERVATION TRENDS SUPPORT THE MODEL FORECAST OF INSTABILITY
REMAINING WEAK OVERNIGHT. THE THUNDERSTORM CHANCE IS LOW.
CLOUDINESS AND MIXING SHOULD HELP HOLD UP TEMPERATURES. EXPECT
LOWS MAINLY IN THE LOWER 60S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/...
MOST PLACES LOOK TO GET WET ON FRIDAY AS A MODERATE STRENGTH UPPER
TROF AND ASSOCIATED COLD FRONT APPROACHES FROM THE WEST. DEEP
MOISTURE FLOW AHEAD OF THE SYSTEM SHOULD RAISE PWS TO AROUND 1.5
INCHES ACROSS THE CWA...AND DECENT LIFT DUE TO DIFFERENTIAL
VORTICITY ADVECTION IN MID LEVELS AND UPPER LEVEL JET DIVERGENCE
WILL PRODUCE WIDESPREAD SHOWERS WITH A FEW THUNDERSTORMS. THERE
WILL BE SOME MODEST LOW LEVEL CAPE WITH VALUES POTENTIALLY AS HIGH
AS 1000 J/KG...BUT DEEP LAYERED SHEAR IS NOT TOO IMPRESSIVE...SO
THE THREAT FOR SEVERE WEATHER LOOKS LOW. QPF WILL GENERALLY BE 1/2
INCH OR LESS...BUT PLACES THAT DO SEE SOME THUNDERSTORMS...
ESPECIALLY IN THE SOUTHEASTERN THIRD OF THE CWA...COULD GET
LOCALLY UP TO AN INCH. TEMPS SHOULD BE SEASONABLY WARM IN THE
UPPER 70S DESPITE CLOUD COVER AS THERE WILL BE LOW LEVEL WARM
ADVECTION AHEAD OF THE COLD FRONT.
FRIDAY NIGHT...THE BEST OF THE UPPER SUPPORT SHOULD MOVE THROUGH
QUICKLY...AS WILL THE COLD FRONT. SHOWERS WILL END FROM WEST TO
EAST DURING THE EVENING...WITH JUST A FEW LINGERING IN THE
SOUTHEAST AFTER MIDNIGHT. TEMPS WILL DROP DOWN INTO THE UPPER
50S...NOT PARTICULARLY COOL AS CLOUDS WILL NOT CLEAR UNTIL LATE
AND WINDS WILL REMAIN UP.
SATURDAY SHOULD BE MOSTLY DRY AS THE FRONT MOVES OFFSHORE. I CANT
RULE OUT A SHOWER IN THE NORTHEAST AS ANOTHER SPOKE OF ENERGY
DROPS INTO NORTH CAROLINA...BUT CHANCES LOOK TOO LOW AT THIS TIME
TO MENTION IN THE FORECAST. TEMPS WILL BE SEASONABLE WITH MID 70S
NORTH TO NEAR 80 IN THE CSRA.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
A SURFACE AREA OF HIGH PRESSURE WILL MOVE INTO THE SOUTHEAST FROM
SUNDAY INTO TUESDAY...KEEPING THE CWA DRY. THE AIR MASS WILL WARM
UP UNDER SUN ANGLE EQUIVALENT TO LATE AUGUST...WITH MAX TEMPS IN
THE LOWER TO MID 80S ON SUNDAY TO THE UPPER 80S TO NEAR 90 ON
TUESDAY. A COLD FRONT WILL APPROACH THE AREA FROM THE NORTH ON
WEDNESDAY...BUT IT IS TOO EARLY TO TELL IF IT WILL STALL JUST
NORTH OF THE CWA OR MAKE IT INTO THE CWA. MOST OF THE MID AND
UPPER LEVEL JET ENERGY WILL STAY TO THE NORTH IN EITHER CASE...BUT
A CLOSER FRONT COULD MEAN A BETTER CHANCE OF DIURNAL CONVECTION
WITH MAX TEMPS WELL UP INTO THE 80S.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS CURRENTLY. SURFACE HIGH CENTER TO OUR EAST
OFFSHORE. UPPER TROUGH AND ASSOCIATED COLD FRONT TO OUR WEST.
SOUTHERLY LOW LEVEL FLOW IN PROGRESS OVER OUR REGION. LATEST ACARS
SOUNDINGS AT CAE CONFIRM SOUTHERLY LOW LEVEL AROUND 30 KT AT 1KFT.
BETTER MOISTURE AND LOW LEVEL MOISTURE CONVERGENCE JUST TO OUR
WEST WHERE A BAND OF SHOWERS CURRENTLY STRETCHES FROM NE GA SW TO
W CENT GA...MOVING NE. LATEST HIGH RESOLUTION MODELS AND RADAR
TRENDS SUGGEST SCATTERED SHOWERS COULD AFFECT OUR TERMINALS LATE
TONIGHT INTO FRIDAY MORNING. IN ADDITION...A MOIST S TO SSW LOW
LEVEL FLOW COULD PROMOTE SOME STRATUS. MODEL CONSENSUS SUGGESTS
MVFR CIGS POSSIBLE. MODELS GENERALLY SUGGEST BANDS OF SHOWERS AND
POSSIBLE THUNDERSTORMS TO AFFECT OUR TERMINALS FRIDAY AFTERNOON
AND EVENING. FOR NOW...WILL HANDLE WITH PREDOMINATE VCSH...WITH
TEMPO SHRA DURING TIME PERIODS WHERE PRECIP APPEARS MORE LIKELY.
MAIN COLD FRONT DOES NOT APPEAR WILL COME THROUGH UNTIL EARLY
SATURDAY MORNING.
EXTENDED AVIATION OUTLOOK...CHANCE OF SHOWERS AND RESTRICTIONS
POSSIBLE THROUGH SATURDAY MORNING. NO SIGNIFICANT IMPACTS TO
AVIATION SATURDAY AFTERNOON THROUGH TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
222 AM EDT FRI APR 22 2016
.SYNOPSIS...
ISSUED AT 135 AM EDT FRI APR 22 2016
A FEW LINGERING SHOWERS CAN BE EXPECTED TODAY...MAINLY ALONG AND
EAST OF STATE HIGHWAY 31. A RUMBLE OF THUNDER IS POSSIBLE. HIGHS
TODAY WILL BE IN THE LOW TO MID 60S...EXCEPT COOLER NEAR LAKE
MICHIGAN. SKIES SHOULD CLEAR TONIGHT WITH LOWS DIPPING TO AROUND
40 DEGREES. SOME OF THE LOCALLY COLDER SPOTS MAY FALL INTO THE
UPPER 30S. PLEASANT WEATHER CAN BE EXPECTED SATURDAY WITH MOSTLY
SUNNY SKIES AND HIGHS IN THE MID TO UPPER 60S.
&&
.UPDATE...
ISSUED AT 804 PM EDT THU APR 21 2016
LEAD VORT MAX WILL CONTINUE TO SHIFT ACROSS NORTHWEST OHIO OVER
THE NEXT HOUR OR TWO. EXTENT/INTENSITY OF THUNDER HAS DIMINISHED
WITH THIS AREA OF RAIN OVER THE PAST FEW HOURS AS FORCING WITH
THIS VORT MAX HAS OUTRUN BETTER INSTABILITY. ADDITIONAL SCATTERED
STORMS HAVE DEVELOPED ACROSS WESTERN PORTIONS OF THE FORECAST AREA
EARLY THIS EVENING COINCIDENT WITH PRIMARY 500-1000 J/KG
INSTABILITY AXIS. INSTABILITY SHOULD BECOME PROGRESSIVELY MORE
ELEVATED OVER NEXT SEVERAL HOURS WHICH SHOULD RESULT IN DOWNWARD
TREND OF CONVECTIVE INTENSITY. STILL SOME LOW END POTENTIAL OF
SOME SMALL HAIL/LOCALIZED WIND GUSTS IN EXCESS OF 40 MPH WITH
STRONGER CORES ACROSS MAINLY WESTERN HALF OF THE FORECAST AREA
THROUGH 03Z HOWEVER. WILL KEEP LIKELY RAIN/CHANCE THUNDER MENTION
GOING THROUGH THE EVENING WITH HIGHEST POPS IN THE SOUTH DUE TO
DIGGING NATURE OF APPROACHING UPPER TROUGH. POCKET OF STEEPER MID
LEVEL LAPSE RATES ADVECTING INTO THE AREA ACCOMPANYING THIS
FEATURE SHOULD PROLONG ISOLD THUNDER POTENTIAL INTO THE OVERNIGHT
HOURS...AND MAINLY ACROSS THE SOUTH/SOUTHEAST. ONLY TWEAK FOR THE
EVENING UPDATE WAS TO REFINE POPS FOR CURRENT TRENDS BUT OTHER
FORECAST ELEMENTS APPEAR TO BE ON TRACK.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 334 PM EDT THU APR 21 2016
MAIN FOCUS ON CONVECTIVE DEVELOPMENT IN FAR WESTERN PARTS OF
FORECAST AREA AS WELL AS UPSTREAM NEAR THE UPPER LOW.
SOME POCKETS OF CLEARING/BREAKS HAVE OCCURRED ALLOWING TEMPERATURES
TO CLIMB INTO THE 60S ACROSS THE AREA AND MAKING A RUN AT 70 IN
WEST/SW LOCATIONS. NARROW PLUME OF HIGHER DEWPOINTS WAS NOW SHIFTING
ACROSS THE FORECAST AREA WITH SLIGHTLY LOWER READINGS UNDER THE
CLEARING AND WHERE CONVECTION WAS ATTEMPTING TO POP. ISOLATED
SHOWERS/STORMS HAVE BEEN DEVELOPING OVER THE LAST 30 TO 60
MINUTES...LIKELY CONTAINING AT LEAST SOME SMALL HAIL. ARC OF STORMS
ONGOING CLOSER TO THE UPPER LOW FROM WATERLOO IOWA TO MOLINE TO WEST
OF SPRINGFIELD IL. HRRR SUGGESTS THIS ACTIVITY WILL MOVE SLOWLY
NORTHEAST AND EXPAND MORE IN THE 22 TO 02Z WINDOW. HAVE KEPT HIGH
SCT TO NUMEROUS SHOWERS WITH MENTION OF THUNDER THROUGH THE EVENING.
EVE SHIFT MAY NEED TO ADJUST FOR TRENDS. TEMPERATURES WILL SLOWLY
FALL THIS EVENING AS AREA REMAINS IN THE WARM SECTOR...WITH SLOW
FALL OVERNIGHT AS THE COLD FRONT APPROACHES.
UPPER LOW WILL CONTINUE TO OPEN AND LINGER FRIDAY...ONLY DRIFTING
SLOWLY EAST INTO SOUTHERN OHIO BY 00Z SAT. GIVEN UPSTREAM TRENDS
UNDER THE UPPER LOW WITH SCATTERED SHOWERS AROUND...SEE NO REASON TO
MAKE ANY MAJOR CHANGES TO SE HALF OF THE AREA INTO MID AFTERNOON
WITH SCATTERED SHOWERS. WHILE NOT INTRODUCED...MAY NEED TO ADD
PASSING MENTION OF THUNDER AS SFC CAPE INCREASES TO AROUND 500 J/KG
AND MARGINAL LAPSE RATES.
&&
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 334 PM EDT THU APR 21 2016
A MORE PROGRESSIVE FLOW PATTERN WILL TAKE HOLD ON THE LOWER 48 THIS
WEEKEND INTO NEXT WEEK AS A SERIES OF WESTERN CONUS SHORTWAVES
EJECT/SHEAR EAST INTO MORE CONFLUENT/WNW FLOW OVER THE GREAT LAKES
REGION. LUCKILY THE WEEKEND WILL FEATURE DRY CONDITIONS WITH HIGH
PRESSURE IN CONTROL IN BETWEEN WAVES. SATURDAY THE COOLER/SUNNIER
DAY UNDER HIGH PRESSURE WITH WARM ADVECTION BEHIND SFC HIGH ALLOWING
HIGHS TO RETURN INTO THE 70S BY SUNDAY. FRONTAL SYSTEMS WITH THE
AFOREMENTIONED SHORTWAVES THEN BRING MORE UNSETTLED WX NEXT
WEEK...WITH LATEST GUIDANCE FAVORING MONDAY/MONDAY NIGHT AND
WEDNESDAY/WEDNESDAY NIGHT FOR HIGHER POPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 123 AM EDT FRI APR 22 2016
A WEAK UPPER LOW WILL DRIFT EAST OVER THE AREA TODAY. A COLD FRONT
WILL MOVE ACROSS THE AREA BEHIND THIS SYSTEM. SOME FOG IS
POSSIBLE...EARLY THIS MORNING ESPECIALLY AT SBN IN CONJUNCTION
WITH THE FRONT PASSAGE. SOME SHOWERS ARE POSSIBLE LATER
TODAY...ESPECIALLY AT FT WAYNE AS THE LOW MOVES EAST AND THE FRONT
MOVES ACROSS THE AREA. FOR NOW...HAVE KEPT AFTERNOON SHOWERS OUT
OF FT WAYNE GIVEN UNCERTAINTY...ALTHOUGH THESE SHOWERS MAY NEED TO
BE ADDED LATER.
&&
.MARINE...
WEBCAMS SHOWING A GOOD DEAL OF DENSE FOG IN THE NEARSHORE WATERS
WARRANTING ISSUANCE OF A MARINE DENSE FOG ADVISORY INTO THIS
EVENING UNTIL COLDER AIR STARTS TO MOVE IN. WILL ALSO HOIST SMALL
CRAFT ADVISORY FOR FRIDAY INTO FRIDAY EVENING FOR INCREASING NW
FLOW AND HIGHER WAVES.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...DENSE FOG ADVISORY UNTIL 2 AM EDT EARLY THIS MORNING FOR LMZ043-
046.
SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 2 AM EDT SATURDAY
FOR LMZ043-046.
&&
$$
UPDATE...MARSILI
SYNOPSIS...SKIPPER
SHORT TERM...FISHER
LONG TERM...STEINWEDEL
AVIATION...SKIPPER
MARINE...FISHER
VISIT US AT WWW.WEATHER.GOV/IWX
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
302 AM CDT FRI APR 22 2016
.SHORT TERM...(Today and Tonight)
Issued at 300 AM CDT FRI APR 22 2016
07Z water vapor imagery showed an upper trough over IL moving to the
east and an upper low off the OR coast. In between these two lows
was an upper ridge along the Rockies. Surface obs showed a weak
ridge of high pressure gradually building south through the central
plains.
The forecast continues to call for dry weather today and tonight due
to no real forcing for precip within the upper ridge. Additionally
there should be some modest dry air advection with the surface ridge
through the day preventing any real chance for precip. There is an
area of low clouds moving south through the MO river valley. RAP and
NAM progs show these clouds should hold together long enough to move
into northeast KS this morning. Otherwise there should be good
insolation by the afternoon. Because of this and with forecast
soundings mixing the boundary layer to near 800 MB, have adjusted
highs for today up a little from the prev forecast expecting
readings between 70 and 75. The surface ridge is progged to move off
to the east tonight with winds freshening from the southeast.
Although the gradient does not appear to be all that strong.
Therefore think low lying areas may decouple with winds remaining
fairly light through the night allowing lows to fall into the mid
40s. Elevated locations may see enough wind through the night for
lows to be around 50.
.LONG TERM...(Saturday through Thursday)
Issued at 300 AM CDT FRI APR 22 2016
Only minor edits to the extended forecast with model guidance
remaining fairly similar to the previous forecast package. Upper
ridging in control with a developing sfc trough to the west Saturday
afternoon will bring gusty south winds to the CWA. Speeds between 15
and 25 mph are likely with gusts peaking at 30 to 35 mph. Gulf
moisture increases dewpoints to the 50s while highs warm back into
the upper 70s and lower 80s. Chances for thunderstorms commence
Saturday evening as a lee trough lifts eastward over the western
plains. GFS and NAM runs at 00Z continue to advertise a slightly
faster progression of the sfc low and weak upper impulse, developing
scattered showers and thunderstorms over north central Kansas
overnight. The ECMWF is slightly slower with these features with the
optimal chances arriving Mon at 12Z. Have adjusted pops accordingly,
increasing the probabilities Sunday afternoon and evening as the
upper trough axis crosses southern NE, while the sfc low and dryline
are depicted similarly over central Kansas 00Z Monday. Steepening
lapse rates and warm moist conditions ahead of the system translate
up to 2000 J/KG of sfc based CAPE with little CIN to prevent
thunderstorm development. Main uncertainty will be mesoscale in
nature such as cloud cover and morning precip which could hinder
severity of convection overnight. However, with this setup any
updraft that does form in the late afternoon will likely be severe
with speed shear up to 6 km near 40 kts. 0-1 km shear enhances with
the LLJ by 00Z as well increasing the threat for tornadoes with any
isolated convection. Otherwise large hail and damaging winds are the
most likely hazards as convection is likely to congeal into a line
as tracks over the CWA Sunday evening.
The passing frontal boundary is still hanging up over southeast
Kansas on Monday with the GFS and ECMWF generating additional
convection Monday evening near the boundary over far east central
and southeast Kansas. Enough MUCAPE and effective shear in this area
will support a few strong to severe storms.
Long term models are still advertising a possible severe weather
event for a portion of the central plains region Tuesday afternoon
and evening as a strong negatively tilted trough lifts out of the
Inter-mountain West. Main discrepancies lie with the exact position
of the frontal boundary and timing of the approaching system as the
boundary lifts northward as a warm front through the day. ECMWF is
faster with the sfc low, lifting the warm front further north
with convection, placing the boundary over northern KS and most of
the CWA within the warm sector. The GFS however is still showing the
warm front bisecting the CWA west to east by 00Z with severe
convection focusing along and north of the boundary. er north with
the dryline centered over central KS. Meanwhile the slower GFS has
been persistent with the warm front bisecting the CWA from west to
east by 00Z Monday. GFS has also been the stronger solution with
over 2000 J/KG of sfc CAPE, minimal CIN and 0-6 KM bulk shear up to
50 kts. Lower lvl shear is stronger as well, enhancing the tornado
threat. Will need to keep monitoring changes, but it does appear
likely for a few severe storms in the area and have increased precip
chances during this period.
The remainder of the extended is more uncertain as the upper low
slowly exits eastward and dry conditions return on Thursday. Next
upper trough appears slower with this package so have backed off on
pops for Thursday at this time.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1201 AM CDT FRI APR 22 2016
Only issue at TOP/MHK will be potential for BR development,
although soundings indicate saturated layer is rather shallow and
wind speeds as high comes in still around 10kts near the NE
border. Will carry MVFR tempo visby at this time and monitor for
updates.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Wolters
LONG TERM...Bowen
AVIATION...67
AREA FORECAST DISCUSSION
NWS JACKSON KY
200 AM EDT FRI APR 22 2016
.UPDATE...
ISSUED AT 200 AM EDT FRI APR 22 2016
FIRST ROUND OF SHOWER ACTIVITY PUSHING ACROSS THE HIGHER TERRAIN
WILL EXIT THE COMMONWEALTH WITHIN THE NEXT HOUR OR TWO. A
SECOND...AND WHAT HAS BEEN A MORE PRONOUNCED ONE...CONTINUES TO
PUSH EAST ACROSS WESTERN KENTUCKY. WILL CONTINUE TO WATCH THIS
CONVECTIVE LINE...BUT GUST FRONT DEVELOPMENT AND WEAKENING OF
UPPER LOW DO NOT BODE TERRIBLY WELL FOR BONAFIDE RAIN CHANCES
SOUTH OF HAL ROGERS PARKWAY FROM THIS ROUND. THESE AREAS WILL HAVE
TO WAIT UNTIL REDEVELOPMENT OCCURS THIS AFTERNOON.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 345 PM EDT THU APR 21 2016
LATEST GOES WV IMAGERY SHOWS MAIN UPPER LEVEL LOW SHIFTING INTO
WESTERN INDIANA THIS AFTERNOON. AS THIS LOW SHIFTS EAST OVERNIGHT
TONIGHT...IT IS EXPECTED TO BECOME AN OPEN WAVE AND WEAKEN. THE
OPEN WAVE WILL THEN DROP SOUTHEASTWARD THROUGH EASTERN KENTUCKY
FRIDAY AFTERNOON/EVENING BEFORE SHIFTING OUT OF OUR AREA BY THE
END OF THE SHORT TERM.
AT THE SURFACE...THE STACKED SFC LOW IS CURRENTLY SWINGING INTO
WESTERN INDIANA WITH A COLD FRONT EXTENDING SOUTH THROUGH WESTERN
KENTUCKY. THIS FRONT IS PROGGED TO MOVE THROUGH OUR AREA LATE THIS
EVENING INTO THE OVERNIGHT HOURS BRINGING WITH IT CHANCES FOR RAIN
AND PERHAPS SOME ISOLATED THUNDER. FOR NOW...SOUTHEASTERLY FLOW
AND DOWNSLOPING EFFECTS HAVE KEPT THE MAJORITY OF EASTERN
KENTUCKY VERY DRY. IN FACT...DEW POINTS ONCE AGAIN DROPPED DOWN
INTO 30S LEADING TO RH VALUES IN 20 AND LOW 30 PERCENT RANGE
/MAINLY IN THE EASTERN HALF OF THE AREA/. THIS WILL ONLY ACT
FURTHER TO SLOW DOWN THE MOISTENING OF THE COLUMN ONCE RAINFALL
MOVES INTO THE REGION...CUTTING DOWN ON ACCUMULATION AMOUNTS.
THE MOST RECENT HIGH RES MODELS SHOW THE MAIN AREA OF RAINFALL
ENTERING WESTERN KENTUCKY AROUND 00Z AND THEN PROGRESSING
EASTWARD DURING THE OVERNIGHT HOURS. ONCE THE FRONT EXITS THE
REGION BY DAWN...SHOWERS WILL LIKELY CONTINUE ON AND OFF
THROUGHOUT THE REMAINDER OF THE DAY INTO EARLY SATURDAY MORNING AS
THE UPPER LEVEL FEATURE PASSES THROUGH. THERE APPEARS TO BE
BETTER INSTABILITY ASSOCIATED WITH THE UPPER LEVEL FEATURE SO
INCLUDED CHANCES FOR THUNDER FOR MOST OF THE DAY TOMORROW. ANY
REMAINING SHOWER ACTIVITY SHOULD EXIT EASTERN KENTUCKY BY DAWN ON
SATURDAY ALLOWING FOR ANOTHER DRY AND SUNNY WEEKEND.
TEMPERATURES WILL REMAIN MILD THROUGH THE SHORT TERM AS RAIN AND
CLOUD COVER INHIBIT RADIATIONAL COOLING/HEATING...WITH LOWS
GENERALLY IN 50S AND AFTERNOON HIGHS IN THE UPPER 60S AND LOW 70S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 400 PM EDT THU APR 21 2016
HIGH PRESSURE AND DRY NORTHERLY AIR WILL BE IN PLACE STARTING THE
DAY SATURDAY...CONTINUING INTO THE DAY SUNDAY AS WINDS BECOME MORE
SRLY ON THE WESTERLY SIDE OF THE HIGH PRESSURE SYSTEM. ABUNDANT SUN
BUT NORTHERLY WINDS ON SATURDAY WILL KEEP AFTERNOON TEMPS IN THE
UPPER 60S AND LOW 70S...BUT THE INTRODUCTION OF SOUTHERLY WINDS WILL
BOOST TEMPS TO AROUND 80 DEGREES BY SUNDAY. WINDS WILL ALSO BE ON
THE INCREASE SUNDAY AS AN UPPER LEVEL SHORTWAVE AND SURFACE LOW
PRESSURE SYSTEM NEAR THE REGION FROM THE CENTRAL PLAINS DURING THE
DAY. MODELS ARE CONTINUING TO TREND BACK ON BOTH THE TIMING OF THE
ASSOCIATED COLD FRONT AS WELL AS THE ASSOCIATED PRECIP AS IT SLOWLY
MOVES EASTWARD THROUGHOUT THE DAY SUNDAY. AT THIS TIME...MODELS ARE
CONTINUING TO KEEP KY DRY THROUGH THE DAY MONDAY...SO AFTER
COLLABORATING WITH OTHER OFFICES AND LOOKING AT LATEST MODEL
DATA...DECIDED TO LEAVE OUT MENTION OF SLIGHT CHANCE OR ABOVE POPS.
THE COLD FRONT WILL ELONGATE ITSELF FROM WEST TO EAST NORTH OF THE
OHIO RIVER BY MONDAY AFTERNOON...BEFORE FINALLY DROPPING SOUTHWARD
INTO THE STATE MONDAY NIGHT. BY THIS POINT THE UPPER LEVEL WAVE AS
WELL AS THE SURFACE LOW WILL QUICKLY FADE OUT...WHILE ANOTHER
SHORTWAVE AND CLOSED UPPER LEVEL LOW BEGINS DEVELOPING JUST WEST OF
THE ORIGINAL. AT THE SURFACE THE NEW STRENGTHENING LOW PRESSURE
CENTER WILL ABSORB THE FRONTAL BOUNDARY...KEEPING IT STRUNG ACROSS
OR NEAR THE OHIO RIVER VALLEY IN SOME FORM. EXPECT THE BOUNDARY TO
OSCILLATE NORTH AND SOUTHWARD ACROSS THE STATE TUESDAY THROUGH
THURSDAY TRANSITIONING FROM A WARM TO A COLD FRONT AS IT MOVES NORTH
VS. SOUTH. REGARDLESS...IT WILL BE QUITE WEAK AS FAR AS OVERALL
MOISTURE ACROSS THE AREA...BUT CONTINUED WARM TEMPS ACROSS THE AREA
AND THE EXISTENCE OF THE LIFTING MECHANISM WILL KEEP THE POTENTIAL
FOR THUNDER IN THE FORECAST EACH DAY. TEMPS WILL GENERALLY REMAIN
AROUND 80 DEGREES IN THE AFTERNOON THROUGH THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 200 AM EDT FRI APR 22 2016
MULTIPLE ROUNDS OF SHOWERS AND EMBEDDED THUNDERSTORMS WILL MOVE
THROUGH EASTERN KENTUCKY TODAY AHEAD OF AN UPPER LEVEL DISTURBANCE
AND COOL FRONT. MAINLY VFR CONDITIONS WILL YIELD TO MVFR CRITERIA
AT TIMES IN HEAVIER SHOWERS AND STORMS...BUT EXACT TIMING AND
SPATIAL EXTENT OF THIS REMAIN IN QUESTION. ROUND OF SHOWERS/STORMS
COMING OUT OF WESTERN KENTUCKY TONIGHT/FRIDAY MORNING SHOULD
PRIMARILY IMPACT KSYM...BEFORE ADDITIONAL ROUNDS DEVELOP LATER
THIS MORNING/AFTERNOON. WILL HAVE TO KEEP TABS ON TSRA DEVELOPMENT
FOR LATER TAF PACKAGES. PRECIPITATION WILL WIND DOWN LATE THIS
AFTERNOON AND THIS EVENING AS CEILINGS BEGIN TO LOWER TO LOW-
RANGE VFR CRITERIA TOWARD 06Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GUSEMAN
SHORT TERM...JVM
LONG TERM...JMW
AVIATION...GUSEMAN
Area Forecast Discussion
National Weather Service Louisville KY
105 AM EDT FRI APR 22 2016
...Updated Aviation Discussion...
...Forecast Update...
Issued at 949 PM EDT Thu Apr 21 2016
Watching line of storms crossing the Wabash River. The storms are
lined up along a corridor of relative instability. However, CIN is
starting to increase, and AMDAR soundings show a low level inversion
setting up, as well predicted by mesoscale models. The line went
right through the Evansville radar, which only showed velocities of
30-40 knots on the lowest scan as the line approached. ProbSvr has
dropped quite a bit over the last few volume scans, lightning has
decreased, and reflectivities have weakened slightly. These trends
all agree with the HRRR showing a weakening of the line as it moves
into southern Indiana. So, will go with the idea of the line
weakening, or at least not producing severe weather in the immediate
future. Will still keep an eye on it, of course.
.SHORT TERM (Now through Friday Night)...
Issued 303 PM EDT Thu Apr 21 2016
The Ohio Valley remains situated in the SW flow between upper ridge
axis to our east and vertically stacked low to our NW. A steady
plume of moisture will continue to ride SW to NE across our region
between these two features through the afternoon and evening. We`re
now beginning to see an eastward push to the activity as a wave
embedded in the southwest flow arrives. In addition to the eastward
push, seeing some convection fire. Expect that numerous showers and
scattered thunderstorms will be the rule for the remainder of the
afternoon, pushing east to a Lexington to Lake Cumberland line
through the evening. With freezing levels low, some small hail may
accompany brief heavy rainfall and a few cloud to ground ligthning
strikes.
Behind the main batch of precipitation, expect a brief lull in
activity as a dry slot works into the region. However as we approach
the evening into the overnight hours, another round of scattered to
numerous showers (and a few storms) will move into our west ahead of
the upper low. Given steeper lapse rates and low freezing levels,
some small hail will still be possible with these storms across our
west into the later evening hours. Expect that intensity and
coverage will diminish as we move through the overnight and lose
instability. Expect mainly scatteed showers exiting the east by dawn.
Lows tonight should be in the mid and upper 50s.
Upper low tracks across our northern CWA on Friday, which will yield
a cloudy and showery period driven by steep low and mid level lapse
rates. Enough instability should result for some thunder chances,
along with small hail/graupel given the low freezing levels. Will
carry scattered to numerous coverage mainly along and east of I-65
through the day. Highs will be noticeably cooler under
cloudy/showery upper low. Look for upper 60s to low 70s.
.LONG TERM (Saturday through Thursday)...
Issued at 303 PM EDT Wed Apr 20 2016
Saturday - Sunday Night...
Progressive upper ridging will build and transition through the
region over the weekend, bringing a return to dry and seasonably
warm temperatures. Saturday will be mostly sunny with a light NE
surface flow. With 850 temps expected to be around 7 to 8 C, expect
high temps in the low to mid 70s. Would be inclined to go a bit
higher, but will knock off a couple degrees given the surface wind
orientation and its generally cooler impact. Temperatures Saturday
evening, will be falling through the 60s.
A dry and cool Saturday night will see temps mostly in the upper 40s
and low 50s, although a few of our eastern spots may see mid 40s.
By Sunday, upper ridge axis will be directly overhead with high
temps recovering to up around 80. Will be inclined to go a degree or
two above MEX guidance for this day given the swing to southerly
flow and slightly deeper mixing. Sunday night will be continued
dry with slightly milder low temps in the upper 50s to around 60.
Monday - Monday Night...
Upper flow begins to flatten out to a more zonal look by the start
of the new work week in response to a passing northern stream wave.
This will allow a trailing cold front to sink southward toward the
Ohio River, becoming parallel to the upper flow as it does. At this
point, models suggest we could see some activity across our far
north by Monday afternoon/evening, however with dry air in place,
expect that things may be delayed a bit, much like we just saw with
today`s system. Models disagree on exact placement, but will tend to
lean toward the slower/drier outcome for now. Expect temps in the
low 80s on the south side of the frontal boundary. Monday night will
bring lows around 60 with a small chance of showers or t-storms
dependent on the setup mentioned above.
Tuesday - Thursday...
The mid week period looks to be more active as the frontal boundary
should be in the vicinity of the region. Do expect that areas along
the boundary would become unstable on the periphery of upper ridging
and with low level moisture pooling on the boundary. Meanwhile,
progressive upper flow would allow for some disturbances to pass
through and ultimately contribute to some convective organization.
For now, will continue with the fcst of temps in the mid and upper
70s and chances for scattered showers and t-storms during this time.
&&
.AVIATION (06Z TAF Update)...
Updated at 1256 AM EDT Fri Apr 22 2016
A line of showers/storms will reach SDF around 5-530z with brief
heavy downpours, lightning and possibily small hail. Upstream
observations have shown very little wind gusts as storms are mainly
elevated at this point.
Plan on this line to weaken some as it approaches LEX toward 7-8z,
and will hold off mentioning thunder as remaining instability should
diminish by then. At BWG, scattered showers may pass the terminal
early this morning, but the bulk of precipitaiton will stay north.
A lull in the activity is expected after sunrise this morning, until
the upper low over Illinois swings over the area. The combination of
the upper low, cold temps aloft and daytime heating will spark
another round of showers and scattered thunderstorms. This is most
likely to impact SDF/LEX during the afternoon. This weather system
should pass east of the area by 00z, giving way to improving
conditions for Friday evening into the weekend.
&&
.LMK Watches/Warnings/Advisories...
KY...NONE.
IN...NONE.
&&
$$
Update.........13
Short Term.....BJS
Long Term......BJS
Aviation.......ZT
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
123 AM EDT FRI APR 22 2016
.SYNOPSIS...
HIGH PRESSURE REMAINS OVER THE WESTERN ATLANTIC TONIGHT. A COLD
FRONT WILL APPROACH FROM THE WEST FRIDAY...PUSHING OFF THE COAST
EARLY SATURDAY MORNING. AN UPPER LEVEL DISTURBANCE DROPS OVER THE
REGION SATURDAY. HIGH PRESSURE RETURNS FOR SATURDAY NIGHT INTO
MONDAY. THE NEXT COLD FRONT PUSHES ACROSS THE REGION TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
FORECAST UPDATED BASED ON LATEST RADAR TRENDS AND HIRES MODEL
GUIDANCE...MAIN CHANGES WERE TO DROP ANY CHC OF PCPN THIS EVENG
AND DELAY POPS A BIT FRI MORNG.
PREVIOUS DISCUSSION...
LATEST REGIONAL RADAR MOSAIC DEPICTS ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS EXTENDING FROM SE NC INTO CENTRAL NC
THIS AFTERNOON. BASED ON LATEST SFC OBS...THE WARM FRONT HAS
LIFTED INTO THE LOCAL AREA...WITH BETTER DESTABILIZATION SOUTH OF
THE LOCAL AREA. EXPECT THE BETTER INSTABILITY TO REMAIN SOUTH OF
THE REGION...BUT HI-RES GUIDANCE CONTINUES TO INDICATE THE
POTENTIAL FOR ISOLATED TO WIDELY SCATTERED SHOWERS LIFTING INTO
SRN VA AND NE NC THRU LATE THIS AFTERNOON. NAM12 300K SURFACES
BACK UP THIS SCENARIO...INDICATING LOW LEVEL LIFT EVEN UNDER THE
UPPER LEVEL RIDGE LOCATED OVER THE ERN CONUS. RAP SOUNDINGS
INDICATE MODEST CAPE EXTENDING INTO THE MIXED PHASE LAYER...SO
WILL MENTION SLIGHT CHANCE FOR THUNDER. ANY SHOWERS THAT DO
DEVELOP WILL DISSIPATE EARLY EVENING WITH THE LOSS OF DAYTIME
HEATING.
TEMPS HAVE WARMED INTO THE MID/UPPER 70S...WITH A FEW LOCALES
HITTING 80 ACROSS THE PIEDMONT INTO CENTRAL VA. SOUTH WINDS AROUND
10 MPH TONIGHT ALONG WITH A PARTLY CLOUDY SKY WILL RESULT IN MILD
OVERNIGHT TEMPS. LOWS GENERALLY IN THE LOW 60S (~+1 STD DEV OR 10-12
DEGS ABOVE NORMAL).
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/...
GENERAL MODEL TRENDS CONTINUE TO SLOW THE UPPER SYSTEM SLIGHTLY AND
DIG IT FARTHER SOUTH AND WEST THROUGH FRIDAY NIGHT. CURRENT NATIONAL
RADAR TRENDS OVER THE OH VALLEY...DEPICT RATHER UNORGANIZED
CONVECTION ASSOCIATED WITH THE UPPER LOW. THE UPPER LOW PUSHES INTO
THE TN VALLEY AS A STRONG UPPER LOW DEEPENS OVER ERN CANADA. THE
FRONT REACHES THE ERN VA PIEDMONT LATE FRIDAY INTO EARLY FRI
EVENING. LEAD SHORTWAVE ENERGY ROUNDS THE BASE OF THE UPPER
TROUGH...LIFTING INTO THE REGION FRI AFTERNOON AHEAD OF THE MAIN
TROUGH ENERGY. RETURN FLOW ADVECTS DEEPER MOISTURE INTO THE
REGION...WITH H85 FLOW COMING IN FROM THE GULF STREAM. POPS RAMP UP
OVER THE PIEDMONT MID TO LATE MORNING...AND THEN POINTS EWD THROUGH
EARLY AFTERNOON. THE FAVORED AREAS FOR SHOWERS CONTINUE TO BE ALONG
AND SOUTH OF A LINE FROM FARMVILLE TO RICHMOND AND TO THE NRN
NECK/MD ERN SHORE FRI AFTERNOON AND FRIDAY EVENING. HAVE MAINTAINED
LIKELY POPS FOR THAT AREA. HAVE TRIMMED BACK POPS NORTH AND WEST OF
THIS LINE AS MODELS INDICATE SHOWER COVERAGE ASSOCIATED WITH THE
MAIN SHORTWAVE WILL BE LIMITED IN THAT REGION. THUNDERSTORM
POTENTIAL REMAINS MARGINAL DUE TO CONSIDERABLE CLOUD COVER AND
MARGINAL INSTABILITY. GIVEN THE DYNAMICS...THETA-E ADVECTION AND THE
TIME OF YEAR...WILL KEEP CHANCE MENTION OF THUNDER. SHEAR REMAINS
MODEST (AOB 30 KT)...SO EXPECT ONLY EMBEDDED THUNDER. PWATS CLIMB TO
1.25 TO 1.5 INCHES...WHICH MAY RESULT IN PERIODS OF MODERATE TO
LOCALLY HEAVY RAINFALL. HOWEVER...QPF AMOUNTS THRU FRIDAY EVENING
WILL GENERALLY RANGE FROM LESS THAN ONE QUARTER OF AN INCH ACROSS
THE NORTH UP TO ONE HALF INCH ACROSS THE SOUTH. AREA REMAINS IN WARM
SECTOR WITH RETURN FLOW PUSHING TEMPS BACK INTO THE MID/UPPER
70S...EVEN WITH CONSIDERABLE CLOUD COVER. SHORTWAVE DROPS OVER THE
CENTRAL APPALACHIANS INTO THE LOCAL AREA THRU FRI NIGHT AS THE FRONT
PUSHES OFFSHORE. WILL KEEP SOLID CHANCE POPS ALONG THE COAST THRU
THE OVERNIGHT PERIOD.
AFOREMENTIONED MODEL TRENDS MEAN LINGERING MID LEVEL MOISTURE TO
GO ALONG WITH THE STRONG DYNAMICS PROVIDED BY THE UPPER LOW DROPPING
OVER THE REGION SAT. WILL HOLD ONTO SOLID CHANCE POPS THROUGH LATE
MORNING INLAND FOR SCATTERED SHOWERS...AND ALONG THE COAST THRU SAT
AFTERNOON. CLOUDY CONDITIONS BECOME PARTLY CLOUDY INLAND SAT
AFTERNOON...BUT REMAIN MOSTLY CLOUDY ALONG THE COAST. TRENDED TOWARD
THE COOLER SIDE OF THE MOS GUIDANCE DUE TO CLOUD COVER AND MODEST
CAA...BUT TEMPS REMAIN SEASONABLE IN THE UPPER 60S/LOW 70S.
NORTH WINDS GENERALLY 10 TO 15 MPH WITH GUSTS OF 20 TO 25 MPH. TROUGH
AXIS PUSHES OFFSHORE SAT NIGHT WITH DRY CONDITIONS FORECAST ACROSS
THE AREA. LOWS IN THE MID/UPPER 40S INLAND TO LOW 50S NEAR THE COAST
UNDER A CLEAR SKY. HIGH PRESSURE BUILDS ACROSS NEW ENGLAND SAT
NIGHT...PARKING OFF THE NORTHEAST COAST SUNDAY. THE RESULT WILL BE
ONGOING DRY CONDITIONS. CAA WANES SUN...BUT LIGHT ONSHORE FLOW WILL
KEEP TEMPS IN CHECK. THICKNESSES YIELD TEMPS IN THE LOW/MID 70S
INLAND AND MID/UPPER 60S ALONG THE COAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE SLIDES FARTHER OFFSHORE SUNDAY NIGHT AND MONDAY...AND
SETTLES OFF THE SOUTHEAST COAST BY TUESDAY. MEANWHILE...A SHORTWAVE
TROUGH AND AN ASSOCIATED COLD FRONT APPROACH FROM THE NW BY TUESDAY
AFTN. MONDAY AND TUESDAY ARE TRENDING TOWARD BEING VERY WARM DAYS
WITH DEEP LAYER WSW FLOW ASSOCIATED WITH A BREAKING DOWN UPPER RIDGE
OVER THE E-CENTRAL/SERN CONUS. MODEL CONSENSUS GENERALLY SUPPORTS
850MB TEMPERATURES OF 12-15C...WHICH WITH FULL MIXING AND
DOWNSLOPING SHOULD EASILY PUSH HIGHS TO 80-85F W OF THE BAY...WITH
UPPER 70S FOR THE ERN SHORE. LOWS SUNDAY NIGHT SHOULD BE IN THE
LOW/MID 50S...WITH 55-60F MONDAY NIGHT. SKY COVER SHOULD GENERALLY
BE MOSTLY CLEAR/SUNNY SUNDAY NIGHT...MONDAY INTO MONDAY NIGHT...AND
BECOME PARTLY SUNNY TUESDAY. THE TROUGH AND COLD FRONT SWING THROUGH
THE AREA TUESDAY AFTN INTO TUESDAY NIGHT. THE MAIN FORCING
ASSOCIATED WITH THE MID/UPPER SHORTWAVE TROUGH GENERALLY PASSES N OF
THE LOCAL AREA...AND DEEP LAYER RH DIMINISHES AS THE FEATURE PASSES
OVER THE LOCAL AREA SO FORECAST POPS ARE ONLY 20%...WITH A NARROW
STRIP OF 30% ACROSS THE FAR N. HIGH PRESSURE BUILDS IN FROM THE N
WEDNESDAY...AND SLIDES OFFSHORE LATER IN THE WEEK. HIGHS WEDNESDAY
SHOULD DROP BACK TO THE MID/UPPER 60S NE...TO THE MID/UPPER 70S
FARTHER INLAND...AND THEN TREND UPWARD INTO THURSDAY AS THE HIGH
SLIDES OFFSHORE. LOWS SHOULD GENERALLY BE IN THE 50S.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS START OFF THE FORECAST PERIOD AND WILL CONTINUE
THROUGH AT LEAST MID MORNING. SOUTH WINDS AVG 10-15 KTS WITH HIGH
AND MID LEVEL CLOUDS INCREASE ESPECIALLY AFTER 12Z.
LATEST MODEL DATA INDICATES A QUICK INCREASE IN MID LEVEL MOISTURE
BY LATE MORNING AS MVFR CIGS (BKN SC) BECOME COMMON. SHOWERS THEN
MOVE WEST TO EAST AFTER 16Z AS A SHORTWAVE MOVES ACROSS THE REGION
WELL AHEAD OF THE APPROACHING COLD FRONT. THUNDER POSSIBLE BUT
WAS KEPT OUT OF THIS FORECAST ISSUANCE SINCE ANY THUNDER NOT EXPECTED
UNTIL AFTER 18Z. MOST LIKELY AREAS TO SEE TSTMS WILL BE ALONG AND
SOUTH OF I64 WITH BEST TIMING BETWEEN 18Z-00Z. SW WIND GUST BETWEEN
15-20 KTS AHEAD OF ANY SHOWER WITH HIGHER GUSTS POSSIBLE IN ANY
TSTMS CLOSER TOWARD 00Z.
ALL MODEL GUIDANCE SUPPORTS IFR CIGS DEVELOPING BY OR SHORTLY
AFTER 00Z ALONG WITH REDUCED VSBYS IN RAIN/SHOWERS AND AREAS
OF FOG. THE COLD FRONT MOVES OFF THE COAST LATE FRI NIGHT/EARLY
SAT. TRAILING CLOSED UPPER LOW WILL CAUSE LAPSE RATES TO INCREASE
WHICH WILL CONTINUE THE POSSIBILITY FOR MVFR CIGS AND SHOWER OR
TSTM DEVELOPMENT INTO SAT. DRIER AIR AND VFR CONDITIONS RETURN
LATE SAT NIGHT.
&&
.MARINE...
WENT AHEAD AND ISSUED A MINIMAL SCA FOR THE CHES BAY THROUGH 4 AM
BASED ON THE AMOUNT OF 20 KT GUSTS REPORTED OVER THE PAST FEW HOURS.
PVS DSCN:
HIGH PRESSURE IS SITUATED WELL OFFSHORE THIS AFTN...WITH
LOW PRESSURE WELL TO THE W OVER THE MID-MISSISSIPPI VALLEY. THE HIGH
WILL CONTINUE TO SLIDE FARTHER OFFSHORE TONIGHT AS LOW PRESSURE
LIFTS NE OVER THE GREAT LAKES. A SW WIND SHOULD AVERAGE 10-15KT
THROUGH THIS EVENING...AND THEN INCREASE TO 15KT BAY/15-20KT OCEAN
LATER THIS EVENING THROUGH FRIDAY MORNING...BEFORE DIMINISHING
FRIDAY AFTN/EVENING AS THE PRESSURE GRADIENT SLACKENS AS A WEAK COLD
FRONT GRADUALLY DROPS INTO THE REGION. THE COLD FRONT PUSHES THROUGH
THE AREA EARLY SATURDAY MORNING...WITH A SUBSEQUENT NORTHERLY SURGE
MIDDAY SATURDAY...WITH A SECONDARY SURGE SATURDAY EVENING. MARGINAL
SCA CONDITIONS ARE POSSIBLE OVER THE BAY (15-20KT N WIND). HIGH
PRESSURE BUILDS OVER THE AREA SATURDAY NIGHT AND SUNDAY...SLIDES
OFFSHORE MONDAY...AND SETTLES OFF THE SOUTHEAST COAST TUESDAY. SEAS
GENERALLY AVERAGE 2-4FT...WITH 2-3FT WAVES IN THE BAY.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR
ANZ630>632-634.
&&
$$
SYNOPSIS...SAM/TMG
NEAR TERM...MAS/SAM
SHORT TERM...SAM
LONG TERM...AJZ
AVIATION...MPR
MARINE...AJZ/MPR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
459 AM EDT FRI APR 22 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EDT FRI APR 22 2016
WV IMAGERY AND RAP ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW INTO
THE NRN LAKES ON THE PERIPHERY OF A DEEP LOW INTO NRN HUDSON BAY.
LOW LEVEL CAA WITH NRLY WINDS INCREASED OVERNIGHT AS THE PRES
GRADIENT TIGHTENED BETWEEN HIGH PRESSURE INTO NRN ONTARIO AND TROUGH
OVER THE LOWER LAKES. CONVERGENT AND UPSLOPE FLOW INTO N CNTRL UPPER
MI COMBINED WITH LINGERING LOW LEVEL MOISTURE SUPPORTED SOME DZ/FZDZ
THAT HAS MIXED WITH LIGHT SNOW.
TODAY...EXPECT THAT THE LIGHT SNOW WILL TRANSITION TO MAINLY DZ/FZDZ
EARLY THIS MORNING AS THE DEEPER MOISTURE DEPARTS...LEAVING THE
MOIST LAYER WARMER THAN -8C. SATELLITE AND MODEL 925-900 MB RH FCST
TRENDS SUGGEST THAT THE LIGHT PCPN SHOULD DIMINISH OR END AROUND
12Z-14Z BUT THAT THE CLOUDS MAY PERSIST...MOVING OUT BTWN 15Z-18Z AS
HIGH PRESSURE WITH LOW LEVEL DRYING BUILDS IN. OTHERWISE...SUNSHINE
WITH 850 MB TEMPS NEAR -2C DURING THE AFTERNOON WILL HELP BOOST
INLAND TEMPS TO AROUND 50. OTHERWISE...NRLY FLOW OFF OF LAKE SUPERIOR
WILL LIMIT HIGH TEMPS CLOSER TO 40.
TONIGHT...ALTHOUGH WINDS WILL DIMINISH WITH THE SFC RIDGE OVER THE
AREA...MID CLOUDS MOVING IN OVERNIGHT WITH 700-500 MB WAA WILL KEEP
TEMPS FROM DROPPING OFF TOO FAR. TEMPS MAY STILL FALL INTO THE MID
20S CENTRAL AND EAST BEFORE THE CLOUDS MOVE IN. OTHERWISE...EXPECT
MIN READINGS IN THE LOWER 30S WEST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 351 AM EDT FRI APR 22 2016
LOOKS LIKE A CHILLY...ACTIVE WX PATTERN WL DOMINATE LATE THIS
WEEKEND INTO EARLY NEXT WEEK AS A VERY TIGHT BAROCLINIC ZN WL SETUP
ACRS THE UPR GREAT LKS UNDER THE CONFLUENCE ZN BTWN ARCTIC AIRSTREAM
IN CANADA AND AN ACTIVE POLAR BRANCH FLOW OVER THE NRN CONUS. SOME
MDT TO HEAVY PCPN IS LIKELY TO FALL OVER AT LEAST THE S HALF OF UPR
MI...WHICH WL BE CLOSER TO A STNRY FNT RUNNING W-E THRU THE UPR
MIDWEST. IF ENUF COLD AIR IN THE NNE FLOW BTWN BLDG HI PRES INTO NRN
ONTARIO AND THE LOWER PRES TO THE S ADVECTS INTO THE CWA AND THIS
AIR IS NOT EXCESSIVELY DRY...THERE COULD BE SOME ACCUMULATING WET SN
OVER MAINLY THE HIER TERRAIN OF NRN UPR MI ON SUN NGT INTO MON.
QUIETER BUT STILL RELATIVELY CHILLY WX WL BE THE RULE FOR MID WEEK.
SAT...UPR MI IS FCST TO BE DOMINATED BY WNW FLOW ALF BTWN UPR RDG
AXIS IN THE PLAINS AND UPR TROFFING IN ERN CANADA. ALTHOUGH MODELS
INDICATE A GOOD DEAL OF MID/HI CLDS RELATED TO WAA TO THE NE OF
SHARPENING FNT FM THE DAKOTAS INTO MN WL IMPACT THE CWA...SUSPECT
LINGERING LLVL DRY AIR ASSOCIATED WITH SLOWLY DEPARTING SFC HI PRES
WL KEEP THE CWA DRY. BEST CHC FOR SOME RAIN WL BE OVER THE NW CWA
CLOSER TO BAND OF STRONGER H7 FGEN TO THE NE OF SHARPENING FNT.
SAT NGT...MODELS IN FAIRLY GOOD AGREEMENT SHOWING MORE WIDESPREAD RA
DVLPG OVER THE CWA ESPECIALLY NEAR THE WI BORDER WITH SHARPENING
BAROCLINIC ZN/FGEN/INCRSG UPR DVGC IN RRQ OF 120KT H3 JET CORE
MOVING TO JUST S OF JAMES BAY BY 12Z SUN. WL CARRY THE HIER
CATEGORICAL POPS NEAR THE WI BORDER IN THE 06Z-12Z PERIOD.
SUN THRU MON...UPR MI IS FCST TO BE CLOSE TO SHARP BAROCLINIC ZN
UNDER CONFLUENCE ZN BTWN ARCTIC BRANCH NW FLOW DOMINATING QUEBEC AND
A WSW POLAR BRANCH FLOW OVER THE NRN CONUS. DESPITE THE UNFAVORABLE
LOOK OF THE CONFLUENT UPR FLOW WELL TO THE NE OF SHRTWV RIDING ENEWD
THRU THE NRN PLAINS WHICH WOULD TEND TO FAVOR DRY WX...MOST OF THE
MEDIUM RANGE MODELS GENERATE SOME MDT TO HEAVY PCPN OVER MAINLY THE
S HALF OF THE CWA. UPR DVGC IN RRQ OF 120KT H3 JET MAX JUST S OF
JAMES BAY AS WELL AS SHARP...PERSISTENT H85-7 FGEN N OF THE H85
WARM/STNRY FNT STRETCHING E ACRS WI FM LO IN THE NRN PLAINS AND
UNDER AXIS OF PWAT AOA AN INCH OVER THE SRN CWA LOOK TO BE THE
ENHANCEMENT FACTORS THAT WOULD OVERCOME THE UPR CONFLUENCE THAT WL
WEAKEN DISTURBANCES RIDING ENEWD TOWARD THE CWA AHEAD OF THE MAIN
SHRTWV TO THE SW. ALTHOUGH SOME OF THE COLDER MODELS` FCST SDNGS/
THERMAL FIELDS WITH H85 TEMPS AOB 0C INDICATE AT LEAST SOME OF THE
PCPN NEAR THE NRN EDGE OF THE BAND WL BE IN THE FORM OF SN...SHARP
GRADIENT IN SFC-H85 MSTR BTWN THE FNT AND CHILLY HI PRES BLDG INTO
NRN ONTARIO WL LIKELY BRING A RATHER SHARP NRN EDGE TO THE PCPN BAND
AND LIMIT THE COVERAGE OF SGNFT SN. BUT IF THE COLDER GUIDANCE IS
CORRECT AND THE LLVL DRYING IS NOT TOO AGGRESSIVE...NOT OUT OF THE
QUESTION THERE COULD BE SEVERAL INCHES OF WET...HEAVY SN OVER
PORTIONS OF THE NRN CWA MAINLY ON SUN NGT/MON MRNG AS STEADY LLVL NE
WINDS ADVECT COLDER AIR INTO THE LKS TO THE S OF THE ONTARIO HI PRES.
MON NGT THRU THU...AS THE HI PRES OVER NORTHERN ONTARIO BUILDS S
INTO THE UPR LKS UNDER CONFLUENT NW FLOW ALF BTWN UPR RDG AXIS
SHIFTING E FM THE PLAINS AND CLOSED UPR LO OVER QUEBEC...EXPECT
LINGERING PCPN TO END ON MON NGT...WITH THE HI PRES BRINGING DRY
WX/MOCLR SKIES ON TUE INTO WED. DEPENDING ON HOW QUICKLY THE QUEBEC
CLOSED LO WEAKENS AND WHETHER OR NOT THE UPR FLOW INTO THE GREAT LKS
TURNS MORE PROGRESSIVE...ANOTHER LO PRES MOVE ENE FM THE PLAINS
COULD BRING MORE PCPN TO THE AREA NEXT THU. BUT IF THE QUEBEC CLOSED
LO IS MORE RESILIENT...THAT NEXT PLAINS LO COULD BE SHUNTED TO THE
SW. EXPECT RELATIVELY CHILLY WX THRU THE EXTENDED PERIOD WITH SUB
ZERO H85 TEMPS DOMINATING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 121 AM EDT FRI APR 22 2016
PRECIPITATION HAS MOSTLY ENDED IN THE WAKE OF YESTERDAY/S COLD
FROPA BUT A COOL/MOIST NORTHERLY FLOW REMAINS AND WITH ADDITIONAL
MOISTURE OFF LK SUPERIOR CEILINGS HAVE LOWERED TO LOW END MVFR TO
IFR THIS EVENING. EXPECT SLOW IMPROVEMENT FOR THE OVERNIGHT
HOURS WITH SKIES CLEARING OUT FRIDAY MORNING AS HIGH PRES BUILDS IN
FROM NW OF LAKE SUPERIOR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 457 AM EDT FRI APR 22 2016
NORTHERLY WINDS 15-25 KNOTS EARLY THIS MORNING ARE EXPECTED TO
DIMINISH TO 20 KTS OR LESS FRIDAY AFTERNOON THROUGH MOST OF SATURDAY
NIGHT AS A HIGH PRESSURE RIDGE CROSSES LAKE SUPERIOR. AS THE HIGH
EXITS TO THE EASTERN SEABOARD AND LOW PRESSURE DEVELOPS OVER THE
PLAINS ON SUNDAY, NORTHEAST WINDS WILL INCREASE TO 20-30 KTS SUNDAY
INTO MONDAY. THE STRONGEST WINDS WILL BE OVER WESTERN LAKE SUPERIOR
WHERE WINDS MAY APPROACH GALES AT TIMES. WINDS DIMINISH TO LESS THAN
20 KTS MONDAY NIGHT INTO TUESDAY AS HIGH PRESSURE MOVES BACK ACROSS
THE REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...VOSS
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1207 AM EDT FRI APR 22 2016
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 327 PM EDT THU APR 21 2016
AFTER SHOWERS AND ISOLATED THUNDERSTORMS EXIT THE AREA EARLY
TONIGHT...CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN SUNDAY AND
CONTINUE WELL INTO NEXT WEEK. SUNDAY WILL BE WARM WITH TEMPERATURES
APPROACHING 70 IN SOME SPOTS. AFTERWARDS...HIGHS WILL BE NEAR
OR SLIGHTLY ABOVE NORMAL WITH HIGHS IN THE LOWER TO MID 60S.
&&
.UPDATE...
ISSUED AT 936 PM EDT THU APR 21 2016
WE HAVE UPDATED THE FCST THIS EVENING TO FRESHEN UP PCPN
TRENDS...PULL THUNDER...AND ADD MORE FOG TO THE FCST AREA-WIDE.
A FEW STORMS TRIED TO MAKE IT UP INTO THE AREA FROM THE S/SW...BUT
COULDN/T QUITE MAKE IT WITH THE LACK OF INSTABILITY UP THIS WAY
WITH ALL OF THE CLOUD COVER TODAY. MODELS ALL SHOW THE INSTABILITY
WILL BE STEADILY ON THE WANE THROUGH THE NIGHT...SO WE PULLED IT
ALTOGETHER.
A FEW SHOWERS ARE AFFECTING THE SE CORNER OF THE CWFA THIS EVENING
LEFT OVER FROM CONVECTION FROM EARLIER ACROSS INDIANA. THESE WILL
BE MOVING OUT SOON...LEAVING ONLY A SMALL CHC OF A SHOWER
OVERNIGHT AS THE SECONDARY FRONT DROPS THROUGH THE AREA.
FOG LOOKS TO BE A LITTLE MORE LIKELY...ESPECIALLY WITH SOME
CLEARING WORKING THROUGH THE SRN TWO THIRDS OF THE CWFA THIS
EVENING. WINDS ARE STILL RELATIVELY LIGHT...AND COULD REMAIN THAT
WAY RIGHT AT THE SFC ALL NIGHT. SOME BETTER MIXING ALOFT WILL MOVE
IN BEHIND THE FRONT. WE EXPECT SOME FOG DEVELOPING...WITH THE
BIGGER ISSUE BEING STRATUS EXPECTED TO MOVE IN FROM THE NORTH
OVERNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 327 PM EDT THU APR 21 2016
EXPERIMENTAL HRRR GUIDANCE IS LOOKING ON TRACK AS CLEARING HAS
SPREAD INTO EXTREME SOUTHWEST LOWER MI AND A THUNDERSTORM ALREADY
HAS DEVELOPED OVER NORTHWEST INDIANA. BASED ON EXPECTED MOVEMENT
TO THE NORTHEAST...WE STILL EXPECT THE BEST CHANCES FOR THUNDERSTORMS
WILL BE SOUTH OF I-96 AND EAST OF KALAMAZOO MAINLY BEFORE MIDNIGHT.
AFTER THIS EXPECT AT LEAST SOME PATCHY FOG NEAR THE I-94 CORRIDOR
THE REST OF THE NIGHT.
AFTER TONIGHT...FORECAST CONCERNS ARE MINIMAL WITH RAIN SHOWERS
APPROACHING FROM THE NORTHWEST ON SATURDAY NIGHT.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 327 PM EDT THU APR 21 2016
A STATIONARY FRONT IS STILL EXPECTED TO SLIDE SLOWLY SOUTH THROUGH
THE CWA SUNDAY INTO MONDAY NIGHT. THIS FRONT WILL HAVE A SOLID GULF
MOISTURE CONNECTION AND THE OVER RIDING ACROSS THIS FRONT SHOULD
PRODUCE A FAIR AMOUNT OF RAIN. IT APPEARS MOST AREAS SHOULD GET A
AROUND AN INCH OF RAIN. THE STEADIEST RAINS SHOULD OCCUR ACROSS
CENTRAL LOWER WHERE THE BEST LIFT PERSISTS ACROSS THE FRONT...AND
OVER AN INCH OF RAIN CERTAINLY SEEMS POSSIBLE HERE. A BIT LIGHTER
RAINS ARE EXPECTED TOWARD I-94. A FEW CLAPS OF THUNDER WILL BE
POSSIBLE BUT NO SEVERE WEATHER IS EXPECTED AT THIS TIME. THE AREA
SHOULD DRY OUT INTO TUESDAY AS A WAVE OF LOW PRESSURE SLIDES ALONG
THE FRONT AND HEADS EAST.
HOWEVER THE DRY SPELL APPEARS BRIEF AS MORE RAIN CHANCES RETURN FOR
WEDNESDAY AND THURSDAY WITH ANOTHER WAVE OF LOW PRESSURE MOVING
ACROSS THE OHIO VALLEY. SIMILAR PATTERN WITH A GOOD CHANCE OF
RAIN...BUT MINIMAL CHANCES FOR SEVERE STORMS.
WE WILL REMAIN MILD UNTIL THE FRONT COMES THROUGH...WITH A COOLER
PERIOD FOR TUESDAY AND WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1207 AM EDT FRI APR 22 2016
WIDESPREAD IFR/LIFR CONDITIONS IN FOG AND LOW CLOUDS ARE LIKELY
OVERNIGHT DUE TO MOIST BOUNDARY LAYER CONDITIONS WITH DEW PTS IN
THE LOWER 50S AND LIGHT SFC WINDS. THE LOWER CIGS/VSBYS WILL
LINGER THROUGH ABOUT 15Z FRIDAY THEN LIFT TO MVFR TO VFR LEVELS IN
THE AFTERNOON AS WINDS INCREASE OUT OF THE NORTH TO AROUND 10 KTS
AND SEND DRIER AIR INTO THE REGION. VFR LIKELY ON FRIDAY NIGHT.
&&
.MARINE...
ISSUED AT 327 PM EDT THU APR 21 2016
FOG HAS BECOME CONSIDERABLY THICKER IN THE LAST COUPLE HOURS SO IN
COORDINATION WITH IWX HAVE HOISTED A MARINE DENSE FOG ADVISORY.
FOG WILL GET SWEPT OUT OVERNIGHT WHEN STRONG NORTH WINDS SPREAD
SOUTH ACROSS LAKE MICHIGAN. RAPIDLY GROWING WAVES WITH THE
STRONGER WINDS AND A VERY FAVORABLE LONG FETCH WILL GIVE US SMALL
CRAFT ADVISORY CONDITIONS QUICKLY FRIDAY MORNING SO HAVE ALSO
ISSUED A SMALL CRAFT ADVISORY WITH THIS PACKAGE.
&&
.HYDROLOGY...
ISSUED AT 158 PM EDT THU APR 21 2016
RAINFALL LAST NIGHT AND TODAY HAS BEEN LIGHT IN NATURE... WITH FEW
TOTALS EXCEEDING A QUARTER INCH. LEVELS ON MAIN STEM RIVERS CONTINUE
A GRADUAL DECLINE... BUT WE HAVE BEEN SEEING RISES ON SMALLER RIVERS
AND CREEKS. NO FLOODING IN ANTICIPATED TODAY OR TOMORROW.
AFTER A QUIET FRIDAY AND SATURDAY... SUNDAY THROUGH THE REST OF NEXT
WEEK LOOKS FAIRLY ACTIVE. A WIDESPREAD INCH OF RAINFALL IS CERTAINLY
POSSIBLE. RIVERS REMAIN ELEVATED... SO WE COULD SEE SOME RISE ABOVE
BANKFULL AND PRODUCE MINOR FLOODING IN LOWLAND AREAS NEXT WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR LMZ844>849.
SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 2 AM EDT SATURDAY
FOR LMZ844>849.
&&
$$
UPDATE...NJJ
SYNOPSIS...TJT
SHORT TERM...TJT
LONG TERM...JK
AVIATION...MEADE
HYDROLOGY...EBW
MARINE...TJT
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1119 PM CDT THU APR 21 2016
.SYNOPSIS...
ISSUED AT 333 PM CDT THU APR 21 2016
H5 ANALYSIS FROM EARLIER THIS MORNING HAD A CLOSED LOW
OVER WESTERN IOWA WITH A TROUGH OF LOW PRESSURE EXTENDING SOUTH INTO
THE ARKLATEX. HT FALLS OF 50 TO 70 METERS WERE NOTED FROM THE MID
MISSISSIPPI VALLEY NORTHWARD TO THE ARROWHEAD OF MINNESOTA. WEST OF
THE TROUGH AND CLOSED LOW...WAS A RIDGE OF HIGH PRESSURE WHICH
EXTENDED FROM THE FOUR CORNERS...NORTH TO NORTHERN MONTANA. WEST OF
THE RIDGE...A TROUGH OF LOW PRESSURE WAS PRESENT FROM THE
ALEUTIANS...SOUTH INTO THE EASTERN PACIFIC...AND WAS ROUGHLY 500
MILES WEST OF THE OREGON AND WASHINGTON COASTS. AT THE SURFACE...LOW
PRESSURE WAS LOCATED OVER CENTRAL IOWA WITH HIGH PRESSURE ANCHORED
ACROSS THE FRONT RANGE OF COLORADO AND WYOMING. ACROSS WESTERN AND
NORTH CENTRAL NEBRASKA...WINDS WERE NORTHERLY BETWEEN THESE TWO
SURFACE FEATURES...AND WERE BREEZY THIS AFTERNOON WITH SPEEDS OF 15
TO 25 MPH. UNDER PARTLY CLOUDY SKIES...TEMPERATURES WERE IN THE
UPPER 60S TO AROUND 70.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 333 PM CDT THU APR 21 2016
MAIN FORECAST CONCERNS ARE WIND AND TEMPERATURES. THE UPPER LOW
CONTINUES ITS SLOW EASTWARD TREK AND GETS ABSORBED WITH THE OVERALL
FLOW OVER THE GREAT LAKES. H5 RIDGE BUILDS OVER THE GREAT PLAINS
WHILE A SURFACE TROUGH APPROACHES THE PANHANDLE LATE FRIDAY.
THIS EVENING AND TONIGHT... EFFICIENT MIXING TO NEAR 750HPA AS
INDICATED BY RAP AND HRRR SOUNDINGS AND NEARLY UNIDIRECTIONAL FLOW
CREATING GUSTS TO 25MPH FOR MUCH OF THE AREA. SOUNDINGS ALSO
INDICATE LOW LEVEL LIFT... WHICH IS CONFIRMED BY A GROWING CUMULUS
FIELD OVER WESTERN NEBRASKA. LEFT PRECIP MENTION OUT AS ABUNDANT DRY
AIR EXISTS IN THE MID LEVELS AND SURFACE DEW POINT DEPRESSIONS REACH
30F WEST TO 20F EAST. CLOUDS WILL CLEAR TONIGHT WITH THE LOSS OF
DIURNAL HEATING AND WINDS RELAX WITH BOUNDARY LAYER DECOUPLING.
MADE LITTLE CHANGE TO MIN TEMPS AS MID/UPPER 30S SEEMED REASONABLE
GIVEN CLEAR SKIES... LIGHT WINDS... AND NEGLIGIBLE TEMP ADVECTION AT
H85.
FRIDAY... CONTINUED THE TREND OF FOLLOWING WARMER GUIDANCE OR GOING
SLIGHTLY ABOVE FOR MAX TEMPS. RETURN FLOW SWITCHES LOW LEVEL WINDS
TO SOUTHERLY... AND MODELS IN AGREEMENT WITH APPRECIABLE WAA. H85
TEMPS RANGE FROM NEAR 20C PANHANDLE TO 10C NORTH CENTRAL... ABOUT 5
TO 10C WARMER THAN THURSDAY. LOW LEVEL WINDS STRENGTHEN THROUGHOUT
THE DAY AS THE PRESSURE GRADIENT INCREASES AHEAD OF THE TROUGH. NAM
SHOWING AROUND 1MB/HR FALLS DURING THE AFTERNOON. COUPLED WITH
SUBSIDENCE AND MIXING TO NEAR 800HPA WHERE H85 WINDS APPROACH
30KTS... GUSTS MAY REACH 25 TO 30MPH AT THE SURFACE. DESPITE WARM
TEMPERATURES AND BREEZY WINDS... FIRE WEATHER DOES NOT APPEAR TO BE
A SIGNIFICANT ISSUE AT THIS TIME. NAM...GFS...AND EURO KEEP SFC DEW
POINTS IN THE 40S DURING THE AFTERNOON... AND MIXING RATIOS INCREASE
1-2G/KG SINCE THURSDAY. MINIMUM RH VALUES STAY ABOVE 25 PERCENT
PANHANDLE AND 30 PERCENT EAST.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 333 PM CDT THU APR 21 2016
MID RANGE...FRIDAY NIGHT THROUGH SUNDAY...A TROUGH OF
LOW PRESSURE ALOFT WILL COME ONSHORE ACROSS NRN CALIFORNIA/OREGON
LATE FRIDAY. THIS FEATURE WILL TRACK EAST INTO WYOMING OVER THE NEXT
24 HOURS...MAKING IT AS FAR EAST AS NWRN WYOMING BY 00Z SUNDAY.
DURING THIS PERIOD...A STRONG LEE SIDE SFC CYCLONE WILL DEVELOP OVER
EASTERN WYOMING AND NERN COLORADO. EAST OF THIS FEATURE...SRLY WINDS
WILL INCREASE FRIDAY AFTERNOON INTO FRIDAY NIGHT. SRLY FLOW WILL
PUSH LOW LEVEL MOISTURE NWD DURING THE NIGHT AND THIS COUPLED WITH
THE SRLY WINDS...WILL MAKE FOR MILD TEMPS FRIDAY NIGHT. FCST LOWS
WILL BE IN THE UPPER 40S TO AROUND 50...SOME 10 TO 15 DEGREES ABOVE
NORMAL. ON SATURDAY...STRONG LOW LEVEL WARM AIR ADVECTION WILL
CONTINUE WITH H85 TEMPS REACHING 25C IN THE WEST BY 00Z SUN. THE
LATEST GUIDANCE REFLECTED THESE WARMER TEMPS SHOWN IN THE GRAPHICAL
NAM AND GFS FCST MODELS FROM THIS MORNING...AND HAVE TRENDED UP
HIGHS FOR SAT AFTN. THIS RESULTED IN HIGHS IN THE LOWER 80S ACROSS
THE BOARD. WE EVEN MAY SEE SOME MIDDLE 80S IN THE NORTHWEST WHERE
DRIER AIR IS EXPECTED SAT AFTN. ON SATURDAY EVENING...A PACIFIC COLD
FRONT WILL APPROACH THE PANHANDLE SAT EVENING...AND A LEAD
DISTURBANCE WILL APPROACH SWRN NEBRASKA FROM NERN COLORADO.
THUNDERSTORM CHANCES WILL INCREASE DURING THE EVENING HOURS WITH THE
BEST CHANCES IN THE SOUTHWEST IN PROXIMITY TO THE UPPER LEVEL
WAVE...AND IN THE NORTHWESTERN CWA INVOF THE FRONT AND CLOSER
PROXIMITY TO THE H5 LOW. AS FOR THE THREAT FOR SEVERE STORMS...WAS
CONCERNED SOMEWHAT ABOUT THE 2000 J/KG CAPES DEPICTED IN THE 12Z
NAM SOLN THIS MORNING...ACROSS CENTRAL PORTIONS OF THE CWA.
HOWEVER...BULK SHEAR IS ONLY 15 TO 20 KTS SAT AFTN/EVE...SO THE
SEVERE THREAT APPEARS MINIMAL ATTM. ON SUNDAY...THE UPPER LEVEL LOW
WILL TRACK ALONG THE NEBR/SD BORDER. ATTM...THE MAIN THREAT FOR PCPN
WILL CONTINUE OVER NRN NEBRASKA WITH MAINLY DRY CONDS IN THE SOUTH.
IT WILL BE WINDY WITH DECENT NORTHWESTERLY WINDS BEHIND THE COLD
FRONT SUNDAY. TEMPERATURES WILL RANGE FROM AROUND 60 IN THE WEST TO
THE MID 70S IN THE FAR EAST.
LONG RANGE...SUNDAY NIGHT THROUGH THURSDAY...AN ACTIVE SWRLY FLOW
PATTERN WILL CONTINUE INTO NEXT WEEK. THE FIRST OF TWO UPPER LEVEL
LOWS WILL APPROACH THE FORECAST AREA MONDAY NIGHT WITH LIKELY PCPN
EXPECTED FOR TUESDAY INTO TUESDAY NIGHT. PCPN WILL LINGER IN THE
NORTH FOR WEDNESDAY...WITH DRY CONDS EXPECTED WEDS NIGHT INTO
THURSDAY. A SECOND SYSTEM WILL APPROACH THE REGION LATE THURSDAY
WITH ANOTHER ROUND OF PCPN ON TAP FOR FRIDAY INTO SATURDAY NEXT
WEEK. TEMPERATURES WILL BE COOL WITH HIGHS IN THE 50S WITH SOME 40S
POSSIBLE IN NRN NEBRASKA TUES/WEDS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1119 PM CDT THU APR 21 2016
VFR IS EXPECTED ALL AREAS OVERNIGHT THROUGH FRIDAY EVENING.
SFC LOW PRESSURE WILL ORGANIZE ACROSS THE NRN HIGH PLAINS BENEATH
AN UPPER LEVEL RIDGE OF HIGH PRESSURE. SKIES SHOULD REMAIN MOSTLY
CLEAR.
&&
.HYDROLOGY...
ISSUED AT 333 PM CDT THU APR 21 2016
RISES ON THE SOUTH PLATTE RIVER EXPECTED TO CONTINUE
OVER THE NEXT SEVERAL DAYS. UPSTREAM GAUGE AT JULESBURG STILL
SHOWING A SLOW RISE WITH AN EXPECTED CREST AT ROSCOE OF AROUND 7.3
FEET LATE FRIDAY/EARLY SATURDAY. ISSUED RVS THIS MORNING WITH
UPDATED FORECAST FROM MBRFC. SLIGHT UPTICK OBSERVED AT NORTH PLATTE
BUT STILL 1.5 FEET BELOW ACTION STAGE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BUTTLER
SHORT TERM...SNIVELY
LONG TERM...BUTTLER
AVIATION...CDC
HYDROLOGY...SNIVELY
AREA FORECAST DISCUSSION
NWS ELKO NV
248 AM PDT FRI APR 22 2016
.SYNOPSIS...BREEZY ACROSS NORTHERN NEVADA TODAY WITH SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS...CENTRAL NEVADA WILL BE DRIER
AND WINDIER THIS AFTERNOON. COOLER THIS WEEKEND WITH INCREASING
SHOWER ACTIVITY. AS COLDER AIR MOVES IN LATE SUNDAY INTO EARLY
NEXT WEEK...VALLEY RAINS WILL TRANSITION TO SNOW IN MANY
LOCATIONS. UNSETTLED WEATHER CONTINUES THROUGH MUCH OF NEXT WEEK.
&&
.SHORT TERM...TODAY THROUGH SUNDAY. TROUGH ENERGY MOVING IN OVER
NORTHERN AND CENTRAL CALIFORNIA TODAY RESULTS IN SOUTHWESTERLY
FLOW OVER NEVADA. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
WILL SPREAD INTO NORTHWESTERN NEVADA LATE THIS MORNING AND
PROGRESS INTO NORTH-CENTRAL NEVADA AND PORTIONS OF NORTHEASTERN
ELKO COUNTY BY THIS AFTERNOON. SOUTHERLY WINDS WILL BE BREEZY OVER
NORTHERN NEVADA WITH AREAS OF BLOWING DUST. CENTRAL NEVADA WILL BE
DRIER AND WINDIER THAN NORTHERN NEVADA TODAY AS THE LEADING EDGE
OF THE JET STREAM MOVES UP UNDER THE APPROACHING TROUGH. EXPANDED
THE WIND ADVISORY TO INCLUDE SOUTHERN LANDER AND EUREKA COUNTIES
AS WELL AS ELKO COUNTY EAST OF THE RUBY MOUNTAINS. THESE NEW WIND
ADVISORY AREAS WILL BE ON THE LIGHTER END OF THE ADVISORY LEVEL
WINDS...WITH STRONGEST WINDS TODAY STILL EXPECTED ACROSS CENTRAL
NEVADA. HIGH TEMPERATURES ACROSS NORTHWESTERN NEVADA WILL BE QUITE
A BIT COOLER TODAY THAN YESTERDAY AS THE TROUGH NEARS. CENTRAL AND
NORTHEASTERN NEVADA WILL BE A LITTLE COOLER THAN YESTERDAY...BUT
STILL WELL ABOVE NORMAL DUE TO STRONG SOUTHERLY FLOW.
THIS EVENING WINDS WILL DIMINISH AS TROUGH ENERGY FROM NORTHERN
CALIFORNIA SLIDES IN OVER NORTHERN NEVADA. COOLER AIR MOVES IN
WITH THE TROUGH TONIGHT WITH VALLEY RAIN AND MOUNTAIN SNOWS. BY
EARLY SATURDAY MORNING SOME OF THE HIGHER ELEVATION VALLEY
LOCATIONS MAY SEE A DUSTING TO POSSIBLY A HALF INCH OF
SNOW...GENERALLY AREAS ABOVE 7000 FEET. SHOWERS CONTINUE ON
SATURDAY BEFORE TAPERING OFF SATURDAY NIGHT AS THE TROUGH EXITS
OFF TO THE EAST.
A SECOND STORM SYSTEM WILL APPROACH FROM THE PACIFIC NORTHWEST
EARLY SUNDAY MORNING...WITH ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS OVER MOST OF NORTHERN AND PORTIONS OF CENTRAL NEVADA
BY SUNDAY AFTERNOON.
.LONG TERM...SUNDAY NIGHT THROUGH NEXT THURSDAY. MODELS ARE IN
PRETTY GOOD AGREEMENT DEPICTING TWO BACK TO BACK MOIST LOW
PRESSURE SYSTEMS TO MOVE THROUGH THE GREAT BASIN. UNSETTLED
WEATHER IS EXPECTED THROUGHOUT THE EXTENDED PERIOD.
SUNDAY NIGHT THROUGH TUESDAY. THIS PERIOD WILL HAVE THE GREATEST
IMPACT FROM SNOWFALL. THE PLACEMENT OF AN UPPER LOW TO IMPACT THE
GREAT BASIN IS ESSENTIALLY THE SAME AS ON PREVIOUS MODEL RUNS
HOWEVER MODELS HAVE MADE ADJUSTMENTS IN THE PROPOSED TRACK OF THE
LOW CENTER. LOW PRESSURE WILL MOVE IN OFF THE PACIFIC...TRAVERSE
OREGON...AND WILL PARALLEL THE SIERRA-NEVADA RANGE WHILE CENTRAL
LOW PRESSURE STAYS EAST THE SIERRA-NEVADA RANGE. THIS WILL FAVOR
THE EASTERN HALF OF THE STATE FOR RECEIVING A GOOD MOIST FLOW. NYE
COUNTY SEEMS TO BE THE SOUTHERN-MOST EXTENT MODELED FOR THE LOW
CENTER MONDAY AFTERNOON BEFORE IT BEGINS TO EJECT EAST-
NORTHEAST...PROVIDING A GOOD WRAP-AROUND MOISTURE EFFECT FOR
NORTHEAST NEVADA. SNOW LEVELS WILL BE FALLING TO THE VALLEY FLOORS
WEST TO EAST MONDAY THUS SNOW SHOULD FALL IN THE VALLEYS MONDAY
THROUGH MONDAY NIGHT. TRAVEL IMPACTS SHOULD BE MINIMAL DURING THE
DAY MONDAY SINCE ROAD TEMPERATURES WILL BE ELEVATED. MONDAY
EVENING MAY GET A LITTLE DICEY EAST OF THE RUBY MOUNTAINS AS
TEMPERATURES FALL BUT THEN PRECIPITATION RATES SHOULD DECREASE AS
THE LOW CENTER MOVES EAST OF THE STATE. THERE IS THE POSSIBILITY
FOR SEVERAL INCHES OF WRAP-AROUND SNOWFALL IN THE COOLER AIR OVER
NORTHERN ELKO COUNTY MONDAY THROUGH TUESDAY. AT THIS
JUNCTURE...THE BIGGEST IMPACT IS EXPECTED ACROSS NORTHERN ELKO
COUNTY...POSSIBLY RECEIVING SEVERAL INCHES OF VALLEY SNOW
ACCUMULATION. THE JARBIDGE WILDERNESS AREA NEAR THE IDAHO BORDER
WITH ELKO COUNTY COULD RECEIVE 8-10 INCHES OF SNOW. SHOWERS WILL
TAPER OFF TUESDAY.
TUESDAY NIGHT THROUGH THURSDAY. LOW PRESSURE CIRCULATING OFF THE
CANADIAN COAST WILL SPIN OFF A POTENT SHORTWAVE THAT WILL TRACK
VERY SIMILAR TO THE PREVIOUS STORM...THEN GET RE-ENFORCED BY THE
MAIN CANADIAN UPPER LOW CENTER MOVING DOWN INTO THE BASE OF THE
MEAN TROUGH THAT WILL GET CARVED OUT OVER SOUTHERN NEVADA AND
SOUTHERN CALIFORNIA THURSDAY. THE AIR MASS IS NOT CURRENTLY
MODELED TO BE EXCEPTIONALLY COLD HOWEVER THERE IS POTENTIAL FOR
SIGNIFICANT MOUNTAIN SNOWFALL ACROSS MUCH OF NORTHERN AND CENTRAL
NEVADA.
&&
.AVIATION...VFR WILL BE THE PREVAILING CONDITION AT KWMC KEKO KELY
AND KTPH THROUGH SATURDAY MORNING. HOWEVER A COLD FRONT WILL BE
APPROACHING AND MOVING THROUGH THE AREA TODAY AND TONIGHT.
THUNDERSTORMS COULD AFFECT ALL FOUR SITES THIS AFTERNOON. GUSTY
WINDS AHEAD OF AND ALONG THE FRONT MAY CAUSE BLOWING DUST AND
REDUCED VISIBILITY AT ALL FOUR SITES. AS SHOWER ACTIVITY INCREASES
TONIGHT AND EARLY SATURDAY...MVFR CIGS ARE POSSIBLE.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 11 AM THIS MORNING TO 9 PM PDT THIS EVENING
FOR NORTHEASTERN NYE COUNTY-NORTHWESTERN NYE COUNTY-SOUTH
CENTRAL ELKO COUNTY-SOUTHEASTERN ELKO COUNTY-SOUTHERN LANDER
COUNTY AND SOUTHERN EUREKA COUNTY-WHITE PINE COUNTY.
&&
$$
96/92/92
[top]
Area Forecast Discussion
National Weather Service Reno NV
238 AM PDT FRI APR 22 2016
SYNOPSIS...
A potent Pacific storm will move through the region today. Strong
and gusty winds can be expected along with valley rain and
mountain snow. A brief break is expected Saturday before a series
of systems is expected next week. Showery conditions are expected
Sunday afternoon and beyond along with cool temperatures.
&&
.SHORT TERM...
Moderate spring storm (by Sierra standards) with a strong cold
front is currently moving on shore and will impact the Sierra and
western Nevada today. No major changes were made to the forecast
with all winter weather and wind advisories still on track today.
Travel over Sierra passes today will very likely be impacted by
winter driving conditions so plan accordingly.
Current radar shows the leading edge of the strong cold front
currently moving into northern California. Instability ahead of
the front is currently creating some convective showers along the
Sierra crest around Donner Summit with off and on light showers
remaining possible until the cold front arrives. Precipitation may
start out as rain but is expected to change over to snow
relatively quickly above 7000 feet. HRRR model solutions show the
leading edge of the main cold front and heavy precipitation will
impact the Sierra around 10-11 am today with passes in the
northern Sierra (Yuba and Fredonyer) receiving heavy precipitation
as early as 7-8 am. For more details on snow amounts and timing
see the winter weather advisories.
Precipitation is expected to quickly spill into the lee of the
Sierra due to very unstable environment along the cold front and
strong upper level jet support. This will lead to periods of
brief moderate precipitation in western Nevada valleys. The
convective nature of this system will lead to wide disparities in
rain and snow amounts from one place to another depending on where
convective bands set up. There will also be the chance for a few
isolated thunderstorms today as the front quickly moves into
western Nevada.
Winds are expected to be quite strong today in western Nevada as
surface gradients tighten and instability will allow strong 700
mb winds to mix to the surface. Widespread winds of 25-35 mph
should be expected with peaks gusts of 50 mph and up to 60 mph in
wind prone areas. This could create some localized areas of
blowing dust which even if brief can cause hazardous driving
conditions.
This system is quite progressive with the cold front expected to
move into Utah by late Friday night. A few showers may linger
along the Sierra crest but the precipitation should be over by
Saturday morning. Brief shortwave ridging on Saturday will be
replaced by another trough digging into the area on Sunday. This
could bring another round of cold air and precipitation on Sunday
into Monday. Zach
.LONG TERM...Monday through Thursday...
Unsettled weather pattern is expected to continue through next week
as late season storm systems line up to move into the West Coast.
There is good agreement in the models that cold low pressure will
remain over the Great Basin on Monday with additional showers and
convective precipitation bands due to unstable conditions.
There is a possibility that we could see snow levels dropping to
near 4500 feet on Monday morning as the coldest air is expected to
move over the Sierra and western NV. Forecast confidence on seeing
snow to the valley floors is low, although there is a chance we
could see light slushy accumulations in the valleys and foothills of
western NV. Models have trended further east into central and
northeastern NV with the heaviest bands, but we will need to keep a
close eye on how this evolves over the next couple days as it has
potential to affect the Monday morning commute. High temperatures on
Monday will struggle to get out of the 40s in western NV and 30s in
the Sierra due to the low pressure overhead and abundant cloud
cover/showers. Low pressure will move out of the area Tuesday with
warming temperatures and clearing skies.
By Wednesday, another low pressure system is expected to move
into northern CA/NV bringing additional chances for showers and
increasing clouds. There is much uncertainty for the Wednesday-
Thursday timeframe regarding precipitation amounts, although this
system doesn`t look to be quite as cold as the the Monday system.
Hoon
&&
.AVIATION...
Multiple weather-related impacts to aviation are expected through
tonight as potent low pressure moves across the region.
Winds will be the primary impact today with wind shear potential,
mainly at KRNO-KCXP-KMMH as winds above the surface increase.
Widespread turbulent conditions are likely through today with peak
gusts up to 45 kt in the lower elevations and Sierra ridge gusts
near 80 kt.
Rain and snow will reach the northern Sierra early this morning,
then spread into western Nevada by this afternoon. Snow levels
should fall to 6000-7000 feet by this afternoon, which may bring IFR
conditions to KTRK, KTVL and KMMH. Snow accumulations on paved
surfaces are unlikely during the day, but some light accumulations
up to 2 inches are possible with the back edge of the snow moving
through this evening. For the western Nevada terminals including
KRNO and KCXP, precipitation will be all rain with reduced ceilings
for MVFR conditions this afternoon-evening. MJD/Hoon
&&
.REV Watches/Warnings/Advisories...
NV...Lake Wind Advisory until 8 AM PDT this morning for Lake Tahoe in
NVZ002.
Winter Weather Advisory from 8 AM this morning to 11 PM PDT this
evening NVZ002.
Wind Advisory from 11 AM this morning to 8 PM PDT this evening
NVZ001-004.
Wind Advisory until 5 PM PDT this afternoon NVZ003.
CA...Winter Weather Advisory from 5 AM early this morning to 5 PM PDT
this afternoon above 5500 feet in CAZ071.
Wind Advisory from 5 AM early this morning to 8 PM PDT this
evening CAZ073.
Lake Wind Advisory until 8 AM PDT this morning for Lake Tahoe in
CAZ072.
Winter Weather Advisory from 8 AM this morning to 11 PM PDT this
evening CAZ072.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno
AREA FORECAST DISCUSSION...CORRECTED
NWS ALBUQUERQUE NM
333 AM MDT FRI APR 22 2016
CORRECTED SECOND PARAGRAPH OF DISCUSSION SECTION
.SYNOPSIS...
MODEST MOISTURE CONTINUES TO WORK ITS WAY INTO CENTRAL NEW MEXICO
FROM THE SOUTHEAST AS A COUPLE OF LOW PRESSURE SYSTEMS CROSS THE
WEST COAST. THESE SYSTEMS WILL SKIRT AROUND NEW MEXICO TO THE
NORTH AND SOUTH...BUT THE MOISTURE IN PLACE WILL HELP SPARK
SCATTERED TO ISOLATED SHOWERS AND THUNDERSTORMS MAINLY OVER
CENTRAL AREAS THIS AFTERNOON AND EVENING...THEN ALONG AND TO A
LESSER EXTENT EAST OF THE CENTRAL MOUNTAIN CHAIN ON SATURDAY. THE
JET STREAM WILL MOVE OVER THE COLORADO AND NEW MEXICO BORDER ON
SATURDAY WITH SURFACE WIND GUSTS PROBABLY REACHING 50 MPH OVER A
GOOD PORTION OF NORTHERN NEW MEXICO IN THE AFTERNOON. FIRE WEATHER
CONCERNS WILL RAMP UP WEST OF THE CENTRAL MOUNTAIN CHAIN
SATURDAY...THEN CONTINUE TO PLAGUE PORTIONS OF NORTHERN AND
CENTRAL NEW MEXICO THROUGH TUESDAY AS DRIER AIR MOVES IN FROM THE
WEST AND BREEZY TO WINDY CONDITIONS RETURN DAILY.
&&
.DISCUSSION...
SOME STORMS WILL PRODUCE LITTLE OR NO RAIN WEST OF THE
CONTINENTAL DIVIDE TODAY...THEN AT LOWER ELEVATIONS BETWEEN THE
CENTRAL MOUNTAIN CHAIN AND CONTINENTAL DIVIDE ON SATURDAY.
MEANWHILE...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS
SATURDAY AFTERNOON AND EVENING IN UNION COUNTY/FAR NE NM.
A PACIFIC COLD FRONT WILL CROSS FROM THE WEST SATURDAY AND
SATURDAY NIGHT USHERING COOLER TEMPERATURES AND DRY AIR FOR
SUNDAY. READINGS WILL VARY AROUND NORMAL MOST PLACES...EXCEPT ON
THE FAR EASTERN PLAINS WHERE READINGS 4 TO 10 DEGREES ABOVE NORMAL
SHOULD PERSIST. BREEZY TO WINDY CONDITIONS ARE EXPECTED TO RETURN
IN THE VICINITY OF THE I-40 CORRIDOR OF EASTERN NM SUNDAY AFTERNOON
WITH WESTERLY DOWNSLOPE FLOW.
ANOTHER UPPER LEVEL LOW PRESSURE SYSTEM WILL DIG INTO THE GREAT
BASIN ON MONDAY...THEN PASS NORTH OF NEW MEXICO ON TUESDAY
STEERING THE JET STREAM SQUARELY OVER THE FORECAST AREA. THIS WILL
KEEP BREEZY TO WINDY CONDITIONS IN THE FORECAST ACROSS WESTERN
AREAS MONDAY AND AREAWIDE TUESDAY. IT WILL CAUSE FIRE WEATHER
CONCERNS TO PERSIST.
SHORT WAVE RIDGING WILL CAUSE WINDS TO SETTLE DOWN WEDNESDAY...BUT
SW FLOW LOOKS TO STRENGTHEN AGAIN DURING THE LATTER HALF OF THE
WEEK AS YET ANOTHER UPPER LEVEL LOW PRESSURE SYSTEM DIGS INTO THE
GREAT BASIN AND APPROACHES NM FROM THE W OR NW.
44
&&
.FIRE WEATHER...
CRITICAL CONDITIONS WILL BE AT LEAST SPOTTY SATURDAY THROUGH MONDAY
WITH MORE WIDESPREAD CRITICAL CONDITIONS POSSIBLE NEXT TUESDAY. VENT
RATES WILL BE GOOD TO EXCELLENT TODAY THROUGH NEXT WEDNESDAY.
THE LATEST MODELS QUITE CONSISTENT WITH PREVIOUS VERSIONS IN THE
SHORTER TERM. THE UPPER RIDGE WILL BE MOVING OVER NEW MEXICO TODAY
AND THEN TO THE EAST OF THE STATE SATURDAY AS AN UPPER LOW TRACKS
INTO THE GREAT BASIN AND THROUGH THE CENTRAL ROCKIES. WINDS ALOFT
WILL TRANSITION TO SOUTHWEST LATER TODAY AND TONIGHT...AND WILL
STRENGTHEN WITH TIME. LOW LEVEL MOISTURE APPEARS TO BE MIGRATING INTO
SOUTH CENTRAL NM AT THIS TIME...AND A SUSTAINED SOUTHEAST TO SOUTH
FLOW REMAINS FORECAST...WHICH WOULD BRING HIGHER DEW POINTS UP THE
RGV AND TOWARDS THE CONTDVD...AS THE GFS HAS BEEN INDICATING FOR
SEVERAL DAYS. RUC AND HRRR NOW JUMPING ONBOARD BREAKING OUT CONVECTION
ALONG THE CONTDVD AND CENTRAL MT CHAIN BY MIDAFTERNOON. WITH THE
POOR RH RECOVERIES ALONG/WEST OF THE CONTDVD AT THIS TIME...CAN/T HELP BUT
THINK THERE MAY BE SOME HIGH BASED VIRGA SHOWERS/ISOLD DRY LIGHTNING
OVER THIS AREA LATER TODAY...GIVEN THE INSTABILITY FORECAST BY THE NAM12.
CONVECTION THIS EVENING MAY RESULT IN SOME WETTING PRECIPITATION BETWEEN THE
CONTDVD AND EAST SLOPES OF THE CENTRAL MT CHAIN.
SATURDAY STILL LOOKS TO SEE WIND GUSTS TO AROUND 45 OR 50 MPH AS THE
WESTERLY WINDS SHOVE THE LOW LEVEL MOISTURE FROM WEST TO EAST OVER
THE STATE. MIN RH VALUES FALL BELOW 15 PERCENT FOR PORTIONS OF THE
MIDDLE RGV AND WEST. DECIDED TO GO AHEAD WITH A FIRE WEATHER WATCH
FOR AREAS BELOW SNOWPACK FOR THE NORTHWEST/WEST CENTRAL AND MIDDLE RGV
ALTHOUGH MAINLY FOR BERNALILLO AND VALENCIA COUNTIES IF THE GRIDS
ARE CLOSE. NOT SURE OF THE STATE OF GREENUP AT THIS TIME...BUT RECENT
COOLER WEATHER MAY HAVE RETARDED IT. HIGHS WILL BE ABOVE AVERAGE...BUT
NOT OVERLY SO...IN THE RANGE OF 5 TO 10 DEGREES.
CONVECTION WILL BE FOCUSED OVER THE CENTRAL AND EAST SATURDAY/SATURDAY
NIGHT BUT SUNDAY LOOKS TO BE DRY. THERE MAY BE A FEW SHOWERS OR STORMS
ON THE DRIER SIDE FROM THE CENTRAL MT CHAIN WWD AS THE MOISTURE BECOMES
MORE SHALLOW ON SATURDAY. RIDGETOP WINDS MAY PERSIST SATURDAY NIGHT BEFORE
RELENTING SOMEWHAT SUNDAY UNDER ZONAL FLOW...BUT NOT ENOUGH TO
ELIMINATE THE POTENTIAL FOR CRITICAL CONDITIONS IN THE EAST CENTRAL
SUNDAY AFTERNOON. RH RECOVERIES SATURDAY AND SUNDAY NIGHT WILL BE
FAIR TO POOR FOR MANY LOCALES.
MONDAY THROUGH TUESDAY WILL SEE INCREASING WINDS AS ANOTHER SYSTEM
SWINGS THROUGH THE CENTRAL ROCKIES. POOR RH RECOVERIES LOOK TO BE
WIDESPREAD MONDAY NIGHT. HIGHS WILL FALL TO AROUND 5 TO 10 DEGREES
BELOW AVERAGE WEST AND CENTRAL AND TO NEAR AVERAGE EAST BY TUESDAY...
TO HELP MODERATE THE COMBO OF WIND AND SUB 15 PERCENT RH FROM THE
MIDDLE RGV TO THE EAST CENTRAL AND NORTHEAST PLAINS TUESDAY AFTERNOON...
WHERE CRITICAL CONDITIONS LOOK TO BE WIDESPREAD. ANY WETTING PRECIPITATION
WILL BE CONFINED TO THE HIGHER TERRAIN OF THE NORTHWEST AND NORTH CENTRAL
MONDAY THROUGH TUESDAY. GUSTY WEST WINDS MAY CONTINUE TUESDAY NIGHT BEFORE
SLACKING OFF. ANOTHER SYSTEM LINED UP FOR THE END OF NEXT WEEK BUT GFS
IS DRIER AND WINDIER...THE ECMWF IS WETTER.
&&
.AVIATION...
06Z TAF CYCLE
UPPER RIDGE ENTERING NM AT PRODUCT GENERATION TIME WILL MOVE OVER
THE STATE OVERNIGHT WITH FLOW ALOFT BECOMING SOUTHWEST LATER FRI.
BACK DOOR FRONT HAS BREACHED THE GAPS OF CENTRAL MT CHAIN AND WILL
CONTINUE TO GENERATE SPOTTY MODERATE E TO SE WINDS UNTIL NEAR OR A
LITTLE BEFORE DAWN. THIS UPSLOPE FLOW MAY STILL LEAD TO A FEW
PATCHES OF MVFR CIGS FROM THE EAST SLOPES CENTRAL MT CHAIN PERHAPS
INTO THE ERN PLAINS AFT 08Z...BUT FOR THE MOST PART CONFIDENCE TOO
LOW TO PLACE THIS DEGREE OF IMPACT IN ANY OF THE TAFS. OVER AND A
LITTLE WAYS EAST OF THE CONTINENTAL DIVIDE AFTER ABOUT 19Z
ISOLATED TO SCT HIGH BASED AND GUSTY SHRA AND TSRA ARE LIKELY TO
DEVELOP AND SOME MAY MAKE AS FAR EAST AS THE CENTRAL MT
CHAIN...INCLUDING ABQ...SAF AND LVS AFTER ROUGHLY 22Z. WHILE MOST
CIGS SHOULD REMAIN VFR...BRIEF AND VERY LOCALIZED MVFR
CONDITIONS...ALONG WITH MT OBSCURATIONS...COULD DEVELOP WITH
STRONGER TSRA.
43
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 79 48 75 36 / 5 5 5 5
DULCE........................... 72 38 70 28 / 30 20 30 10
CUBA............................ 71 41 71 32 / 40 40 20 5
GALLUP.......................... 78 43 73 31 / 5 10 0 0
EL MORRO........................ 72 38 68 30 / 30 20 0 0
GRANTS.......................... 76 39 74 32 / 30 20 5 5
QUEMADO......................... 75 42 72 37 / 20 10 0 0
GLENWOOD........................ 81 43 78 40 / 20 10 0 0
CHAMA........................... 66 37 64 27 / 30 30 40 10
LOS ALAMOS...................... 69 48 71 40 / 20 50 30 10
PECOS........................... 72 44 73 38 / 30 50 30 10
CERRO/QUESTA.................... 70 42 70 33 / 20 20 30 20
RED RIVER....................... 56 37 54 31 / 20 20 30 20
ANGEL FIRE...................... 64 33 64 28 / 20 40 30 20
TAOS............................ 70 41 70 32 / 20 40 30 10
MORA............................ 69 44 69 37 / 30 50 30 20
ESPANOLA........................ 76 50 76 39 / 20 50 20 10
SANTA FE........................ 71 47 71 40 / 20 50 30 10
SANTA FE AIRPORT................ 74 47 74 39 / 20 50 20 10
ALBUQUERQUE FOOTHILLS........... 77 55 78 46 / 10 50 20 5
ALBUQUERQUE HEIGHTS............. 79 52 81 46 / 10 50 10 5
ALBUQUERQUE VALLEY.............. 81 52 83 45 / 10 50 10 5
ALBUQUERQUE WEST MESA........... 80 52 82 45 / 10 50 10 5
LOS LUNAS....................... 80 51 82 45 / 10 50 10 5
RIO RANCHO...................... 79 53 80 45 / 10 50 10 5
SOCORRO......................... 80 52 84 47 / 10 30 10 5
SANDIA PARK/CEDAR CREST......... 72 49 73 42 / 20 50 20 5
TIJERAS......................... 76 50 76 43 / 20 50 20 5
MORIARTY/ESTANCIA............... 76 44 76 38 / 10 50 20 5
CLINES CORNERS.................. 73 44 73 39 / 20 40 30 10
GRAN QUIVIRA.................... 73 49 73 45 / 20 30 20 5
CARRIZOZO....................... 77 50 77 48 / 10 20 20 10
RUIDOSO......................... 71 46 71 45 / 30 20 30 10
CAPULIN......................... 70 48 72 40 / 20 20 20 20
RATON........................... 74 43 76 38 / 20 20 20 20
SPRINGER........................ 76 46 77 40 / 30 30 20 20
LAS VEGAS....................... 73 44 74 38 / 20 40 30 20
CLAYTON......................... 77 50 82 47 / 10 10 20 20
ROY............................. 73 48 77 43 / 20 30 20 20
CONCHAS......................... 81 54 85 51 / 10 20 20 20
SANTA ROSA...................... 80 51 83 50 / 10 20 20 20
TUCUMCARI....................... 82 52 87 51 / 5 10 20 10
CLOVIS.......................... 79 51 83 52 / 5 5 20 10
PORTALES........................ 79 52 83 54 / 5 5 20 10
FORT SUMNER..................... 79 52 84 51 / 5 10 20 10
ROSWELL......................... 83 53 87 52 / 10 10 20 10
PICACHO......................... 79 50 82 51 / 20 20 20 10
ELK............................. 74 48 75 48 / 20 30 20 10
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING
FOR THE FOLLOWING ZONES... NMZ101-105-106.
&&
$$
44
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
330 AM MDT FRI APR 22 2016
.SYNOPSIS...
MODEST MOISTURE CONTINUES TO WORK ITS WAY INTO CENTRAL NEW MEXICO
FROM THE SOUTHEAST AS A COUPLE OF LOW PRESSURE SYSTEMS CROSS THE
WEST COAST. THESE SYSTEMS WILL SKIRT AROUND NEW MEXICO TO THE
NORTH AND SOUTH...BUT THE MOISTURE IN PLACE WILL HELP SPARK
SCATTERED TO ISOLATED SHOWERS AND THUNDERSTORMS MAINLY OVER
CENTRAL AREAS THIS AFTERNOON AND EVENING...THEN ALONG AND TO A
LESSER EXTENT EAST OF THE CENTRAL MOUNTAIN CHAIN ON SATURDAY. THE
JET STREAM WILL MOVE OVER THE COLORADO AND NEW MEXICO BORDER ON
SATURDAY WITH SURFACE WIND GUSTS PROBABLY REACHING 50 MPH OVER A
GOOD PORTION OF NORTHERN NEW MEXICO IN THE AFTERNOON. FIRE WEATHER
CONCERNS WILL RAMP UP WEST OF THE CENTRAL MOUNTAIN CHAIN
SATURDAY...THEN CONTINUE TO PLAGUE PORTIONS OF NORTHERN AND
CENTRAL NEW MEXICO THROUGH TUESDAY AS DRIER AIR MOVES IN FROM THE
WEST AND BREEZY TO WINDY CONDITIONS RETURN DAILY.
&&
.DISCUSSION...
SOME STORMS WILL PRODUCE LITTLE OR NO RAIN WEST OF THE
CONTINENTAL DIVIDE TODAY...THEN AT LOWER ELEVATIONS BETWEEN THE
CENTRAL MOUNTAIN CHAIN AND CONTINENTAL DIVIDE ON SATURDAY.
MEANWHILE...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORM
SATURDAY AFTERNOON AND EVENING IN UNION COUNTY/FAR NE NM.
A PACIFIC COLD FRONT WILL CROSS FROM THE WEST SATURDAY AND
SATURDAY NIGHT USHERING COOLER TEMPERATURES AND DRY AIR FOR
SUNDAY. READINGS WILL VARY AROUND NORMAL MOST PLACES...EXCEPT ON
THE FAR EASTERN PLAINS WHERE READINGS 4 TO 10 DEGREES ABOVE NORMAL
SHOULD PERSIST. BREEZY TO WINDY CONDITIONS ARE EXPECTED TO RETURN
IN THE VICINITY OF THE I-40 CORRIDOR OF EASTERN NM SATURDAY
AFTERNOON WITH WESTERLY DOWNSLOPE FLOW.
ANOTHER UPPER LEVEL LOW PRESSURE SYSTEM WILL DIG INTO THE GREAT
BASIN ON MONDAY...THEN PASS NORTH OF NEW MEXICO ON TUESDAY
STEERING THE JET STREAM SQUARELY OVER THE FORECAST AREA. THIS WILL
KEEP BREEZY TO WINDY CONDITIONS IN THE FORECAST ACROSS WESTERN
AREAS MONDAY AND AREAWIDE TUESDAY. IT WILL CAUSE FIRE WEATHER
CONCERNS TO PERSIST.
SHORT WAVE RIDGING WILL CAUSE WINDS TO SETTLE DOWN WEDNESDAY...BUT
SW FLOW LOOKS TO STRENGTHEN AGAIN DURING THE LATTER HALF OF THE
WEEK AS YET ANOTHER UPPER LEVEL LOW PRESSURE SYSTEM DIGS INTO THE
GREAT BASIN AND APPROACHES NM FROM THE W OR NW.
44
&&
.FIRE WEATHER...
CRITICAL CONDITIONS WILL BE AT LEAST SPOTTY SATURDAY THROUGH MONDAY
WITH MORE WIDESPREAD CRITICAL CONDITIONS POSSIBLE NEXT TUESDAY. VENT
RATES WILL BE GOOD TO EXCELLENT TODAY THROUGH NEXT WEDNESDAY.
THE LATEST MODELS QUITE CONSISTENT WITH PREVIOUS VERSIONS IN THE
SHORTER TERM. THE UPPER RIDGE WILL BE MOVING OVER NEW MEXICO TODAY
AND THEN TO THE EAST OF THE STATE SATURDAY AS AN UPPER LOW TRACKS
INTO THE GREAT BASIN AND THROUGH THE CENTRAL ROCKIES. WINDS ALOFT
WILL TRANSITION TO SOUTHWEST LATER TODAY AND TONIGHT...AND WILL
STRENGTHEN WITH TIME. LOW LEVEL MOISTURE APPEARS TO BE MIGRATING INTO
SOUTH CENTRAL NM AT THIS TIME...AND A SUSTAINED SOUTHEAST TO SOUTH
FLOW REMAINS FORECAST...WHICH WOULD BRING HIGHER DEW POINTS UP THE
RGV AND TOWARDS THE CONTDVD...AS THE GFS HAS BEEN INDICATING FOR
SEVERAL DAYS. RUC AND HRRR NOW JUMPING ONBOARD BREAKING OUT CONVECTION
ALONG THE CONTDVD AND CENTRAL MT CHAIN BY MIDAFTERNOON. WITH THE
POOR RH RECOVERIES ALONG/WEST OF THE CONTDVD AT THIS TIME...CAN/T HELP BUT
THINK THERE MAY BE SOME HIGH BASED VIRGA SHOWERS/ISOLD DRY LIGHTNING
OVER THIS AREA LATER TODAY...GIVEN THE INSTABILITY FORECAST BY THE NAM12.
CONVECTION THIS EVENING MAY RESULT IN SOME WETTING PRECIPITATION BETWEEN THE
CONTDVD AND EAST SLOPES OF THE CENTRAL MT CHAIN.
SATURDAY STILL LOOKS TO SEE WIND GUSTS TO AROUND 45 OR 50 MPH AS THE
WESTERLY WINDS SHOVE THE LOW LEVEL MOISTURE FROM WEST TO EAST OVER
THE STATE. MIN RH VALUES FALL BELOW 15 PERCENT FOR PORTIONS OF THE
MIDDLE RGV AND WEST. DECIDED TO GO AHEAD WITH A FIRE WEATHER WATCH
FOR AREAS BELOW SNOWPACK FOR THE NORTHWEST/WEST CENTRAL AND MIDDLE RGV
ALTHOUGH MAINLY FOR BERNALILLO AND VALENCIA COUNTIES IF THE GRIDS
ARE CLOSE. NOT SURE OF THE STATE OF GREENUP AT THIS TIME...BUT RECENT
COOLER WEATHER MAY HAVE RETARDED IT. HIGHS WILL BE ABOVE AVERAGE...BUT
NOT OVERLY SO...IN THE RANGE OF 5 TO 10 DEGREES.
CONVECTION WILL BE FOCUSED OVER THE CENTRAL AND EAST SATURDAY/SATURDAY
NIGHT BUT SUNDAY LOOKS TO BE DRY. THERE MAY BE A FEW SHOWERS OR STORMS
ON THE DRIER SIDE FROM THE CENTRAL MT CHAIN WWD AS THE MOISTURE BECOMES
MORE SHALLOW ON SATURDAY. RIDGETOP WINDS MAY PERSIST SATURDAY NIGHT BEFORE
RELENTING SOMEWHAT SUNDAY UNDER ZONAL FLOW...BUT NOT ENOUGH TO
ELIMINATE THE POTENTIAL FOR CRITICAL CONDITIONS IN THE EAST CENTRAL
SUNDAY AFTERNOON. RH RECOVERIES SATURDAY AND SUNDAY NIGHT WILL BE
FAIR TO POOR FOR MANY LOCALES.
MONDAY THROUGH TUESDAY WILL SEE INCREASING WINDS AS ANOTHER SYSTEM
SWINGS THROUGH THE CENTRAL ROCKIES. POOR RH RECOVERIES LOOK TO BE
WIDESPREAD MONDAY NIGHT. HIGHS WILL FALL TO AROUND 5 TO 10 DEGREES
BELOW AVERAGE WEST AND CENTRAL AND TO NEAR AVERAGE EAST BY TUESDAY...
TO HELP MODERATE THE COMBO OF WIND AND SUB 15 PERCENT RH FROM THE
MIDDLE RGV TO THE EAST CENTRAL AND NORTHEAST PLAINS TUESDAY AFTERNOON...
WHERE CRITICAL CONDITIONS LOOK TO BE WIDESPREAD. ANY WETTING PRECIPITATION
WILL BE CONFINED TO THE HIGHER TERRAIN OF THE NORTHWEST AND NORTH CENTRAL
MONDAY THROUGH TUESDAY. GUSTY WEST WINDS MAY CONTINUE TUESDAY NIGHT BEFORE
SLACKING OFF. ANOTHER SYSTEM LINED UP FOR THE END OF NEXT WEEK BUT GFS
IS DRIER AND WINDIER...THE ECMWF IS WETTER.
&&
.AVIATION...
06Z TAF CYCLE
UPPER RIDGE ENTERING NM AT PRODUCT GENERATION TIME WILL MOVE OVER
THE STATE OVERNIGHT WITH FLOW ALOFT BECOMING SOUTHWEST LATER FRI.
BACK DOOR FRONT HAS BREACHED THE GAPS OF CENTRAL MT CHAIN AND WILL
CONTINUE TO GENERATE SPOTTY MODERATE E TO SE WINDS UNTIL NEAR OR A
LITTLE BEFORE DAWN. THIS UPSLOPE FLOW MAY STILL LEAD TO A FEW
PATCHES OF MVFR CIGS FROM THE EAST SLOPES CENTRAL MT CHAIN PERHAPS
INTO THE ERN PLAINS AFT 08Z...BUT FOR THE MOST PART CONFIDENCE TOO
LOW TO PLACE THIS DEGREE OF IMPACT IN ANY OF THE TAFS. OVER AND A
LITTLE WAYS EAST OF THE CONTINENTAL DIVIDE AFTER ABOUT 19Z
ISOLATED TO SCT HIGH BASED AND GUSTY SHRA AND TSRA ARE LIKELY TO
DEVELOP AND SOME MAY MAKE AS FAR EAST AS THE CENTRAL MT
CHAIN...INCLUDING ABQ...SAF AND LVS AFTER ROUGHLY 22Z. WHILE MOST
CIGS SHOULD REMAIN VFR...BRIEF AND VERY LOCALIZED MVFR
CONDITIONS...ALONG WITH MT OBSCURATIONS...COULD DEVELOP WITH
STRONGER TSRA.
43
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 79 48 75 36 / 5 5 5 5
DULCE........................... 72 38 70 28 / 30 20 30 10
CUBA............................ 71 41 71 32 / 40 40 20 5
GALLUP.......................... 78 43 73 31 / 5 10 0 0
EL MORRO........................ 72 38 68 30 / 30 20 0 0
GRANTS.......................... 76 39 74 32 / 30 20 5 5
QUEMADO......................... 75 42 72 37 / 20 10 0 0
GLENWOOD........................ 81 43 78 40 / 20 10 0 0
CHAMA........................... 66 37 64 27 / 30 30 40 10
LOS ALAMOS...................... 69 48 71 40 / 20 50 30 10
PECOS........................... 72 44 73 38 / 30 50 30 10
CERRO/QUESTA.................... 70 42 70 33 / 20 20 30 20
RED RIVER....................... 56 37 54 31 / 20 20 30 20
ANGEL FIRE...................... 64 33 64 28 / 20 40 30 20
TAOS............................ 70 41 70 32 / 20 40 30 10
MORA............................ 69 44 69 37 / 30 50 30 20
ESPANOLA........................ 76 50 76 39 / 20 50 20 10
SANTA FE........................ 71 47 71 40 / 20 50 30 10
SANTA FE AIRPORT................ 74 47 74 39 / 20 50 20 10
ALBUQUERQUE FOOTHILLS........... 77 55 78 46 / 10 50 20 5
ALBUQUERQUE HEIGHTS............. 79 52 81 46 / 10 50 10 5
ALBUQUERQUE VALLEY.............. 81 52 83 45 / 10 50 10 5
ALBUQUERQUE WEST MESA........... 80 52 82 45 / 10 50 10 5
LOS LUNAS....................... 80 51 82 45 / 10 50 10 5
RIO RANCHO...................... 79 53 80 45 / 10 50 10 5
SOCORRO......................... 80 52 84 47 / 10 30 10 5
SANDIA PARK/CEDAR CREST......... 72 49 73 42 / 20 50 20 5
TIJERAS......................... 76 50 76 43 / 20 50 20 5
MORIARTY/ESTANCIA............... 76 44 76 38 / 10 50 20 5
CLINES CORNERS.................. 73 44 73 39 / 20 40 30 10
GRAN QUIVIRA.................... 73 49 73 45 / 20 30 20 5
CARRIZOZO....................... 77 50 77 48 / 10 20 20 10
RUIDOSO......................... 71 46 71 45 / 30 20 30 10
CAPULIN......................... 70 48 72 40 / 20 20 20 20
RATON........................... 74 43 76 38 / 20 20 20 20
SPRINGER........................ 76 46 77 40 / 30 30 20 20
LAS VEGAS....................... 73 44 74 38 / 20 40 30 20
CLAYTON......................... 77 50 82 47 / 10 10 20 20
ROY............................. 73 48 77 43 / 20 30 20 20
CONCHAS......................... 81 54 85 51 / 10 20 20 20
SANTA ROSA...................... 80 51 83 50 / 10 20 20 20
TUCUMCARI....................... 82 52 87 51 / 5 10 20 10
CLOVIS.......................... 79 51 83 52 / 5 5 20 10
PORTALES........................ 79 52 83 54 / 5 5 20 10
FORT SUMNER..................... 79 52 84 51 / 5 10 20 10
ROSWELL......................... 83 53 87 52 / 10 10 20 10
PICACHO......................... 79 50 82 51 / 20 20 20 10
ELK............................. 74 48 75 48 / 20 30 20 10
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING
FOR THE FOLLOWING ZONES... NMZ101-105-106.
&&
$$
44
AREA FORECAST DISCUSSION
NWS PENDLETON OR
1030 PM PDT THU APR 21 2016
.UPDATE...A TROUGH CONTINUES TO APPROACH THE COAST THIS EVENING AS
THE RIDGE THAT HAS BEEN OVER THE AREA MOVES EAST. A WAVE EMBEDDED IN
THE SOUTHERLY FLOW OVER WASHINGTON AND OREGON HAS BEEN GENERATING
SHOWERS AND A THUNDERSTORM OR TWO WEST OF THE CASCADES. MODELS SHOW
THE DISTURBANCE MOVING INTO OUR AREA OVERNIGHT. THE NAM AND THE
SHORT TERM HRRR AND RUC13 MODELS ALL SHOW SHOWERS DEVELOPING LATER
TONIGHT OVER THE EASTERN MOUNTAINS AND PROPAGATING NORTH THROUGH THE
COLUMBIA BASIN BEFORE EXITING AROUND SUNRISE. RADAR IS ALREADY
SHOWING SOME ECHOES IN NORTHERN MALHEUR AND BAKER COUNTIES AND SEE
CELLS DEVELOPING IN NORTHERN NEVADA SO HAVE ADDED ISOLATED RAIN
SHOWERS FROM JOHN DAY EASTWARD IN THE MOUNTAINS AND FROM HANFORD
EASTWARD IN THE COLUMBIA BASIN. HAVE KEPT THE ISOLATED SHOWERS ALONG
THE CASCADES AND INTO CENTRAL OREGON NORTH TO YAKIMA AND ELLENSBURG.
HAVE ALSO RAISED CLOUD COVER TO MOSTLY CLOUDY FOR THE REST OF THE
NIGHT. MADE A FEW SMALL ADJUSTMENTS TO THE WIND AS WELL. REST OF THE
FORECAST LOOKED GOOD. FORECAST UPDATES ALREADY OUT. PERRY
.AVIATION...06Z TAFS. CEILINGS BKN 060-100 TONIGHT INTO FRIDAY. A
FEW SHOWERS POSSIBLE EARLY TONIGHT FROM BDN/RDM TO DLS. OTHERWISE
BEST CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS WILL BE FRIDAY.
WINDS 5-10KT TONIGHT INCREASING TO 10-20KT LATER FRIDAY.
&&
.SHORT TERM...TONIGHT THROUGH SUNDAY...THE HIGH PRESSURE RIDGE AXIS
IS SHIFTING EASTWARD AS A TROUGH OF LOW PRESSURE IN THE GULF OF
ALASKA SLIDES TOWARD THE PACIFIC NORTHWEST. THE TROUGH WILL FORM A
CLOSED LOW OFF THE SOUTHWEST COAST OF OREGON BY FRIDAY AFTERNOON.
THE ATMOSPHERE OVER EASTERN OREGON AND WASHINGTON WILL BEGIN TO
DESTABILIZE FRIDAY AS THE LOW APPROACHES LEADING TO AN INCREASE IN
SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA. THE LOW WILL
THEN MOVE OVER THE REGION FRIDAY NIGHT AND EXIT EARLY SATURDAY WITH
SHOWERS DECREASING OVERNIGHT. MODELS ARE HINTING THAT SOME MOISTURE
WRAPPING BACK AROUND THE LOW COULD IMPACT FAR NORTHEAST OREGON AND
SOUTHEAST WASHINGTON THROUGH SATURDAY MORNING SO HAVE BUMPED UP POPS
FOR THIS. OTHERWISE SATURDAY WILL BE AN IN BETWEEN WEATHER SYSTEMS
DAY BEFORE THE NEXT UPPER LEVEL LOW DROPS INTO THE PACIFIC NORTHWEST
LATE SUNDAY. THIS WILL ONCE AGAIN INCREASE SHOWERS AND BRING A
POSSIBILITY SOME THUNDERSTORMS TO PORTIONS OF THE FORECAST AREA.
THERE WILL ALSO BE SOME INCREASING WESTERLY WINDS FRIDAY AND THROUGH
THE WEEKEND USHERING IN SOME COOLER AIR. SNOW LEVELS WILL BE
DROPPING TO 5000 TO 6000 FEET ON FRIDAY NIGHT AND THEN DOWN TO 4000
TO 5000 FEET ON SUNDAY.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...A LARGE UPPER LOW WILL
BE MOVING SOUTHEAST ACROSS OREGON ON SUNDAY NIGHT. THIS WILL BRING A
GOOD CHANCE OF SHOWERS AND HIGH MOUNTAIN SNOW SHOWERS TO THE AREA.
ON MONDAY THE LOW WILL BE OVER THE GREAT BASIN BUT WRAP AROUND
MOISTURE ESPECIALLY IN OREGON WILL BRING A CONTINUED CHANCE FOR
SHOWERS AND MOUNTAIN SNOW SHOWERS ABOVE 4000-4500 FEET. WITH THE LOW
OVER THE CENTRAL ROCKIES ON TUESDAY AND SLIGHT RIDGING OVER THE AREA
EXPECT A DECREASE IN SHOWER ACTIVITY. BY WEDNESDAY ANOTHER UPPER LOW
WILL EITHER MOVE OVER OR JUST SOUTH OF THE REGION WITH INCREASING
CHANCES FOR SHOWERS. BY THURSDAY SHOWERS WILL BEGIN TO TAPER OFF.
THERE MAY BE ENOUGH INSTABILITY FOR THUNDERSTORMS WEDNESDAY AND
THURSDAY BUT THE MARGINAL NATURE OF THE THREAT SEVERAL DAYS OUT
PRECLUDES A MENTION IN THE FORECAST AT THIS TIME. IT WILL BE WINDY
THROUGH THE COLUMBIA RIVER GORGE AND KITTITAS VALLEY SUNDAY NIGHT
THROUGH MONDAY. TEMPERATURES WILL START OUT NEAR OR SLIGHTLY BELOW
NORMAL AND THEN RISE TO SLIGHTLY ABOVE NORMAL BY THE END OF THE
FORECAST PERIOD. 78
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 52 74 50 65 / 10 40 40 10
ALW 56 76 50 66 / 10 40 40 20
PSC 59 76 51 72 / 10 20 20 10
YKM 52 74 47 71 / 20 30 20 10
HRI 53 76 51 68 / 10 20 20 10
ELN 51 73 49 65 / 20 40 20 10
RDM 41 62 37 60 / 10 60 40 10
LGD 46 70 44 58 / 20 60 60 30
GCD 47 67 44 58 / 10 70 60 10
DLS 52 69 50 65 / 20 40 20 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
83/94
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
412 AM CDT FRI APR 22 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 412 AM CDT FRI APR 22 2016
THE REAL CHALLENGE TODAY WILL BE THE EXPANDING STRATUS FIELD ACROSS
PARTS OF NORTHWEST IOWA AND SOUTHWEST MINNESOTA. WHILE IT HAS THUS
FAR REMAIN JUST EAST OF FSD AND SUX...STILL A DECENT CHANCE THAT IT
COULD EXPAND FURTHER TO THE WEST...ESPECIALLY AROUND SUX. EXPECT THE
STRATUS TO LINGER THROUGH MID TO LATE MORNING IN PARTS OF NORTHWEST
IOWA AND SOUTHWEST MINNESOTA...BEFORE GIVING WAY TO A SUNNY
DAY.STARTING TO GET A LITTLE WORRIED HOWEVER WITH A LOW LEVEL WIND
FIELD TURNING TO THE NORTHEAST AND EAST THROUGH THE DAY THAT THIS
STRATUS WILL BE DIFFICULT TO SHAKE. WINDS WILL BE LIGHT ACROSS THE
AREA AND WITH PLENTY OF SUNSHINE HIGHS IN THE 60S WILL FEEL PRETTY
NICE.
BY TONIGHT THE RIDGE OF HIGH PRESSURE WILL MOVE EAST OF THE AREA
ALLOWING A SOUTH TO SOUTHEAST WIND TO DEVELOP. LOWS WILL BE MILDEST
IN CENTRAL SOUTH DAKOTA WHERE WINDS WILL INCREASE QUICKEST WHILE THE
COOLER READINGS WILL BE IN THE LOW SPOTS ACROSS NORTHWEST IOWA WHERE
WINDS WILL LIKELY REMAIN AT ABOUT 6 OR 7 MPH OR LESS THROUGH MOST OF
THE NIGHT. EXPECT LOWS TO RANGE FROM THE LOWER 50S IN CENTRAL SOUTH
DAKOTA TO THE MID 40S IN NORTHWEST IOWA.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 412 AM CDT FRI APR 22 2016
SOUTHERLY FLOW INCREASES ON SATURDAY AS AN INTENSIFYING AREA OF LOW
PRESSURE APPROACHES FROM THE WEST. WITH THE GULF OPENING UP...THERE
IS SOME QUESTION AS TO HOW QUICKLY MOISTURE RETURNS ACROSS THE
AREA.MODELS SUGGEST 20-30 KNOTS OF SOUTHERLY FLOW THROUGH A DEEP
PORTION OF THE ATMOSPHERE...AND WITH A LITTLE EASTERLY COMPONENT
SHOULD KEEP SPEEDS BELOW ADVISORY LEVEL. THE NAM IS THE MOST
AGGRESSIVE WITH THE MOISTURE...AND ACTUALLY BECOMES UNSTABLE WITH
SATURATION AROUND 800 MB BY SUNDAY MORNING. THE OPERATIONAL RUN OF
THE NAM IS CLOSE TO 2000 J/KG OF CAPE...WHILE OTHER MEMBERS OF THE
SREF ARE MUCH MORE STABLE. WITH THE OPERATIONAL RUN OF THE NAM
BEING AN OUTLIER AND THE GFS REMAINING STABLE...IS A TOUGH CALL AND
LEFT LOW POPS IN. BEST CHANCES FOR STORMS ON SUNDAY APPEAR TO BE IN
THE EAST AHEAD OF THE TROUGH.
AS THE TROUGH MOVES THROUGH...MUCH COOLER MORE STABLE AIR IS
EXPECTED TO MOVE IN. MODEL SOUNDINGS SUGGEST STRATUS
POTENTIAL...AND MAY SQUEEZE OUT SOME DRIZZLE. DROPPED MENTION OF
POPS AT THIS POINT ACROSS THE SOUTH...AND MAY NEED TO DO THE SAME
THING IN THE NORTH AS ATMOSPHERE APPEARS TO BE QUITE STABLE. FOR
NOW...DROPPED POPS JUST TO A SLIGHT CHANCE.
DROPPED MENTION OF POPS ON MONDAY NIGHT AS FORECAST AREA IS IN
BETWEEN SYSTEMS. NEXT SYSTEM MOVES INTO THE CENTRAL PORTIONS OF THE
PLAINS. TOUGH CALL ON HIGHS ON TUESDAY...AS WE WILL LIKELY BE
SHROUDED IN CLOUDS WITH INCREASING EASTERLY FLOW. REAL QUESTION AS
TO HOW FAR NORTH THE WARM FRONT WILL WORK THROUGHOUT THE DAY. FOR
NOW...DECREASED HIGHS A FEW DEGREES ACROSS THE NORTH WHERE THE WARM
FRONT IS UNLIKELY TO REACH.
THEREAFTER...DIFFICULT FORECAST AS MODELS ARE UNSURE HOW MUCH COLD
AIR WILL COME DOWN. JUST THE GFS AND ECMWF ARE OFF NEARLY 10C AT 925
HPA. FOR NOW...STUCK FAIRLY CLOSE TO CONSENSUS...WHICH IS NEARLY
ISOTHERMAL IN THE EC WORLD.
SURFACE RIDGE IS EXPECTED TO BUILD INTO THE REGION LATE WEEK... BUT
APPEARS AS THOUGH CLOUDS WILL ACCOMPANY THE RIDGE...MAKING
TEMPERATURES TRICKY. FOR NOW...STUCK CLOSE TO CONSENSUS BUT COULD
BE STUBBORN TO WARM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1041 PM CDT THU APR 21 2016
06Z TAFS ARE LIKELY GOING TO REFLECT VFR CONDITIONS WITH A COUPLE
OF CAVEATS. FIRST...STILL A LITTLE CONCERNED ABOUT PATCHY FOG
DEVELOPMENT IN THE JAMES RIVER VALLEY LATE TONIGHT AND EARLY
FRIDAY...RIGHT ALONG A SURFACE RIDGE AXIS WHICH WILL GIVE VERY
LIGHT WINDS IN THAT AREA. THEREFORE HEDGED WITH SOME MVFR TYPE FOG
FOR KHON...BUT AT THIS TIME DO NOT HAVE ENOUGH CONFIDENCE TO GO
ANY WORSE THEN THAT SINCE THE FOG MAY NOT FORM AT ALL. SECOND...
THERE ARE SOME INDICATIONS FROM THE LATEST NAM AND HRRR FIELDS
THAT THERE WILL BE ABUNDANT HUMIDITY IN THE VERY LOW LEVELS JUST
ABOVE THE SURFACE LATE TONIGHT THROUGH MID FRIDAY MORNING AT KSUX.
THE GROUND IS QUITE WET IN THAT AREA...SO IT MAY BE AN ARTIFACT OF
GROUND MOISTURE. BUT FOR A HEADS UP...DECIDED TO INCLUDE A
SCATTERED DECK AT 800 FEET JUST IN CASE SOME LOWER STRATUS FORMS
JUST BEFORE SUNRISE AND LINGERS INTO MID MORNING AT KSUX.
OTHERWISE CURRENTLY...UPPER END IFR TO MVFR STRATUS IS MOVING
SOUTHWARD ACROSS PARTS OF SOUTHWEST MN AND NORTHWEST IA. AT THIS
TIME...THE TRAJECTORY OF THESE CLOUDS SUGGEST THAT THEY WILL STAY
TOO FAR EAST TO IMPACT KSUX OR KFSD...BUT ESPECIALLY AT KSUX...IT
WILL BE CLOSE FOR A FEW HOURS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...08
LONG TERM...BT
AVIATION...MJ
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
111 AM CDT FRI APR 22 2016
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...SOME LOCALIZED FOG NOW IN CAMERON COUNTY...ESPECIALLY
AT HRL. LOOKS LIKE MVFR CEILINGS WILL DEVELOP AND PERSIST THROUGH
MID TO LATE THIS MORNING. HIGH PRESSURE ASSOCIATED WITH A WEAK
FRONT WILL PUSH INTO THE AREA TODAY WITH LIGHT WINDS BACKING TO
EAST AND NORTHEAST. COULD SEE A FEW SHOWERS AROUND THE AREA THIS
MORNING...BUT DRIER AIR WILL BE MOVING IN LATER IN THE DAY...WITH
DIMINISHED RAIN CHANCES TONIGHT...FRIDAY NIGHT.
&&
.PREV DISCUSSION... /ISSUED 337 PM CDT THU APR 21 2016/
SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...LATEST SATELLITE IMAGERY
SHOWS AN OUTFLOW BOUNDARY EXTENDING FROM NORTH OF LAREDO TO NEAR
KINGSVILLE THIS AFTERNOON. THE COMBINATION OF A SOUTHWARD MOVING
BOUNDARY ACROSS SOUTH TEXAS...AN INLAND MOVING SEA BREEZE EXTENDING
FROM BROWNSVILLE TO NEAR CORPUS CHRISTI AND DAYTIME HEATING WILL
SUPPORT THE DEVELOPMENT OF ISOLATED TO SCATTERED CONVECTION FOR THE
REST OF THE AFTERNOON INTO THIS EVENING. BROWNSVILLE RADAR CURRENTLY
SHOWS ISOLATED ACTIVITY ACROSS KENEDY AND WILLACY COUNTIES. THE
STORM PREDICTION CENTER /SPC/ HAS ALL OF DEEP SOUTH TEXAS UNDER A
MARGINAL RISK OF SEVERE WEATHER THROUGH TONIGHT. THE MAIN THREATS
FROM ANY OF THE STORMS THAT DEVELOP THIS AFTERNOON INTO THIS EVENING
WILL BE SMALL HAIL...GUSTY WINDS AND LOCALLY HEAVY RAINFALL.
THE 21Z HRRR INDICATES CONVECTION WILL CONTINUE TO DEVELOP ACROSS
THE COASTAL COUNTIES THROUGH LATE AFTERNOON WITH ADDITIONAL
DEVELOPMENT ACROSS ZAPATA AND STARR THIS EVENING. THE 12Z NAM KEEPS
MOST OF THE CONVECTION OVER THE GULF WATERS...THE 12Z GFS SHOWS A
LITTLE CONVECTION OVER THE VALLEY...AND THE 12Z ECMWF SHOWS MORE
ROBUST CONVECTION ACROSS THE AREA. BASED ON CURRENT TRENDS WILL GO
ABOVE MET/MAV GUIDANCE FOR POPS THROUGH THE REST OF THIS AFTERNOON
AND EVENING.
THE APPROACH AND PASSAGE OF A 500 MB DISTURBANCE ALONG WITH A WEAK
COLD FRONT SAGGING SOUTH WILL GENERATE ISOLATED SCATTERED CONVECTION
OVER PORTIONS OF DEEP SOUTH TEXAS TONIGHT. THE COLD FRONT STALLS
OVER DEEP SOUTH TEXAS FRIDAY AND FRIDAY NIGHT. POOLING MOISTURE IN
ADVANCE OF THIS SURFACE FEATURE WILL COMBINE WITH DAYTIME
HEATING...AND ENHANCED SEA BREEZE EFFECT...AND ANOTHER WEAK 500 MB
DISTURBANCE TO PRODUCE MAINLY SCATTERED CONVECTION ON FRIDAY. LOW
TEMPERATURES TONIGHT WILL GENERALLY BE IN THE LOWER 70S. HIGH
TEMPERATURES FRIDAY WILL RANGE FROM THE LOWER 80S NEAR THE COAST TO
THE UPPER ACROSS THE UPPER VALLEY. LOW TEMPERATURES WILL BE SLIGHTLY
COOLER FRIDAY NIGHT WITH TEMPERATURES FALLING INTO THE MID 60S TO
AROUND 70.
MARINE...NOW THROUGH FRIDAY NIGHT...BUOY 42020 REPORTED NORTH WINDS
AROUND 2 KNOTS GUSTING TO AROUND 4 KNOTS WITH SEAS SLIGHTLY UNDER
3.3 FEET WITH A PERIOD OF 7 SECONDS AT 15 CDT/19 UTC. A WEAK
GRADIENT ALONG THE LOWER TEXAS COAST WILL MAINTAIN LIGHT TO MODERATE
WINDS AND LOW TO MODERATE SEAS THROUGH THE PERIOD. NO SMALL CRAFT
EXERCISE CAUTION OR SMALL CRAFT ADVISORY ANTICIPATED.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
54/66
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
324 AM EDT FRI APR 22 2016
.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL APPROACH THE REGION FROM THE WEST
TODAY BEFORE PASSING THROUGH THE AREA OVERNIGHT INTO EARLY
SATURDAY. HIGH PRESSURE SHOULD BUILD IN BEHIND THIS SYSTEM LATER
SATURDAY AND REMAIN OVER THE REGION THROUGH MONDAY. THE NEXT COLD
FRONT WILL SLIDE SOUTH THROUGH THE AREA ON TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 240 AM EDT FRIDAY...
WEAKENING UPPER LOW AND ITS ASSOCIATED SURFACE COLD FRONT WILL FINALLY
PUSH EAST TODAY REACHING THE BLUE RIDGE THIS EVENING BEFORE THE FRONT
SLIDES TOWARD THE COAST TOWARD DAYBREAK SATURDAY. QUICK INCREASE IN
DEEPER MOISTURE PER SPIKE IN PWATS TO JUST BELOW 1.5 INCHES SHOULD
BRING A BIT MORE IN THE WAY OF MUCH NEEDED RAINFALL INTO THIS
EVENING. HOWEVER JUST HOW THINGS UNFOLD AND THE DEGREE OF DEEPER
CONVECTION REMAINS UNCERTAIN...ESPCLY GIVEN POTENTIAL FOR MULTIPLE
BANDS AHEAD OF THE FRONT DESPITE LACK OF DEEP INSTABILITY PER
LIMITED PROLONGED HEATING. LATEST MODELS DEPICT THIS WELL WITH AN
INITIAL BAND OF SHOWERS REDEVELOPING OVER THE WEST THIS MORNING
ALONG AN AXIS OF DIFFLUENCE AND DRIVEN BY WEAK SHORTWAVE ENERGY
JUST AHEAD OF THE ACTUAL FRONT. HRRR HAS THIS AXIS OF RATHER LIGHT
SHOWERS ALL THE WAY OUT TO THE BLUE RIDGE THIS MORNING WHICH LOOKS
OVERDONE...ALTHOUGH OTHER SOLUTIONS VARY ON TIMING BUT TEND TO
SUPPORT THIS SCENARIO.
ONCE THIS BAND SPREADS EAST...GUIDANCE SHOWS SOME INCREASE IN
INSTABILITY OUT EAST ALONG ITS LEADING EDGE...AND THEN OUT WEST
AHEAD OF ANOTHER BAND OR TWO JUST AHEAD OF THE FRONT. HOWEVER
FORECAST CAPES/BULK SHEAR NOT IMPRESSIVE ESPCLY WITH INSOLATION
TEMPERED BY CLOUDS/SHRA UNLESS MODELS ARE OVERDONE AND MORE
HEATING IS REALIZED. FOR NOW WILL TREND TOWARD WESTERN SHOWER
COVERAGE EARLY...THEN HAVE MORE WIDESPREAD SHOWERS PER LIKELY OR
BETTER POPS THIS AFTERNOON ALL SECTIONS...INCLUDING MORE THUNDER
MENTION FAR WEST AND ESPCLY SOUTHEAST WHERE SHOULD GET A LITTLE
MORE HEATING. OTRW KEEPING MAINLY ISOLATED THUNDER MENTION
ELSEWHERE WHICH MAY BE GENEROUS. TRIMMED HIGH TEMPS BACK A CAT OR
SO ESPCLY WEST WHERE COULD GET STUCK IN THE 60S WITH ONLY THE EAST
PERHAPS 67-72 OR WARMER.
CORRIDOR OF BETTER LIFT SHOULD SPILL EAST OF THE AREA AHEAD OF THE
FRONT THIS EVENING WITH THE OPENING 5H LOW LIKELY KEEPING SOME SHOWERS
AND ISOLATED TSRA GOING MAINLY NORTH/NW ESPCLY BEFORE MIDNIGHT. OTRW
FLOW TURNING NW BEHIND THE BOUNDARY LOOKS TO CUT INTO LINGERING
SHRA ELSEWHERE...SO STEADILY REDUCING POPS AFTER 00Z WITH ONLY
20/30 POPS REMAINING FOR THE MOST PART AFTER MIDNIGHT. TOTAL QPF
LOOKS TO BE A BIT MORE PENDING COVERAGE WITHIN BANDS PERHAPS
RESULTING IN .30 TO .75 WITH THE HIGHEST AMOUNTS OVER THE SOUTH
AND WEST AT THIS POINT. COOL ADVECTION BEHIND THE FRONT RATHER
WEAK OVERNIGHT AND WITH LINGERING CLOUDS EXPECT LOWS TO REMAIN
MOSTLY IN THE UPPER 40S TO MID 50S.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 245 AM EDT FRIDAY...
AN UPPER LOW WILL DROP SOUTHEAST ACROSS THE REGION ON SATURDAY WITH
ISOLATED TO SCATTERED SHOWERS. HIGH TEMPERATURES ON SATURDAY WILL
RANGE FROM THE UPPER 50S IN THE MOUNTAINS TO THE MID 70S IN THE
PIEDMONT.
THE UPPER TROUGH WILL PUSH OUT INTO THE ATLANTIC OCEAN SATURDAY
EVENING. THIS WILL ALLOW HIGH PRESSURE TO BUILD INTO OUR REGION
SATURDAY NIGHT. LOW TEMPERATURES SATURDAY NIGHT WILL VARY FROM
AROUND 40 IN THE NORTHWEST MOUNTAINS TO THE LOWER 50S IN THE
PIEDMONT.
A 1020 MB SURFACE HIGH PRESSURE WILL BUILD ACROSS OUR AREA SUNDAY.
HIGH TEMPERATURES WILL WARM INTO THE UPPER 60S IN THE WEST TO THE
UPPER 70S IN THE EAST. UNDER MOSTLY CLEAR SKIES...SUNDAY NIGHT LOW
TEMPERATURES WILL DROP INTO THE UPPER 40S TO LOWER 50S. HIGH
PRESSURE WILL REMAINS JUST OF THE NORTH CAROLINA COAST MONDAY INTO
MONDAY NIGHT. IT WILL BE A WARM START TO THE WORKWEEK WITH HIGHS
MONDAY FROM THE MID 70S IN THE MOUNTAINS TO THE LOWER 80S IN THE
PIEDMONT. LOW TEMPERATURES MONDAY NIGHT WILL BE MILD WITH READINGS
GENERALLY IN THE MID 50S TO AROUND 60 DEGREES.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 245 AM EDT FRIDAY...
GUIDANCE OFFERS SOLUTIONS OF A COLD FRONT APPROACHING AND CROSSING
THE AREA TUESDAY INTO WEDNESDAY. HOWEVER...TIMING VARIES BETWEEN THE
GFS AND ECMWF...ALONG WITH THE EXTENT PRECIPITATION WILL REACH AND
PERSIST INTO THE FORECAST REGION.
THE UNCERTAINTY OF THE ABOVE EVENT...TIES INTO THE EVEN GREATER
UNCERTAINTY OF THE NEXT EVENT. THE COLD FRONT IS EXPECTED TO STALL
EITHER OVER...OR SOUTH OF...THE REGION FOR A BRIEF PERIOD OF TIME.
AN APPROACHING UPPER LOW/TROUGH WILL HELP SWING LOW LEVEL WINDS TO
THE SOUTHWEST WEDNESDAY INTO THURSDAY AND LIFT THE STALLED FRONT
BACK NORTH AS A WARM FRONT. AGAIN...WITH EACH SOLUTION OFFERING
DIFFERENCES IN TIMING...PRECIPITATION AMOUNTS AND EXTENT OF THE
PRECIPITATION.
OUR LATEST FORECAST WILL REFLECT A CONSENSUS OF THESE AND OTHER
SOLUTIONS BY WEIGHING HEAVILY ON THE SUPERBLEND SOLUTION. THIS
SCENARIO OFFERS A SLIGHTLY SLOWER ARRIVAL TIME OF THE PRECIPITATION
MONDAY NIGHT INTO TUESDAY...LITTLE CHANGE TO THE PRIOR WEDNESDAY
FORECAST...AND SCATTERED SHOWERS ACROSS THE AREA ON THURSDAY.
INSTABILITY LOOKS STRONG ENOUGH FOR AT LEAST ISOLATED THUNDERSTORMS
TUESDAY...WEDNESDAY...AND THURSDAY AFTERNOON.
TEMPERATURES DURING THIS PORTION OF THE FORECAST WILL TREND MILDER
THROUGH TUESDAY...AND THEN SLIGHTLY COOLER THROUGH THURSDAY.
READINGS WILL BE AROUND TEN DEGREES ABOVE NORMAL FOR THIS TIME OF
YEAR.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
AS OF 1245 AM EDT FRIDAY...
FLYING CONDITIONS WILL REMAIN VFR A WHILE LONGER OVERNIGHT WITH
CIGS LIKELY QUICKLY DECREASING TO MVFR OR WORSE FROM SW TO NE BY
DAYBREAK AS DEEPER MOISTURE ALONG AN INITIAL FADING BAND OF
SHOWERS WORKS EAST. HOWEVER GIVEN DRYNESS SEEN IN THE EARLIER
EVENING SOUNDINGS...MAY TAKE LONGER TO MOISTEN UP THE COLUMN SO
DELAYED THE ONSET OF THE SUB-VFR CONDITIONS UNTIL JUST BEFORE DAWN
FAR WEST AND BLUE RIDGE INCLUDING POINTS EAST AROUND 12Z/8AM.
COULD ALSO SEE PERIODS OF MVFR VSBYS IN SHOWERS PENDING
REDEVELOPMENT OF THE CURRENT WEAKER BAND OF RAIN OVER THE
MOUNTAINS. LATEST MODEL SUITE CONTINUES TO SUGGEST THAT THIS AREA
OF SHOWERS WILL BECOME MORE WIDESPREAD LATE SO KEEPING LOWER VSBYS
IN SHRA MOST SPOTS BY DAWN.
LOTS OF UNCERTAINTY IN REGARDS TO CIGS AND SHOWER COVERAGE DURING
FRIDAY WITH MODELS WANTING TO MARCH THE EARLY BAND OF SHOWERS EAST
ACROSS KDAN/KLYH MAKING FOR LESS INSTABILITY OVER THE REGION AHEAD
OF THE ACTUAL COLD FRONT LATER IN THE DAY. THIS WOULD TEND TO
LIMIT DEEP CONVECTION TO PERHAPS THE FAR WEST WHERE MAY SEE MORE
BREAKS SOONER WITH MORE EMBEDDED NATURE TSRA ELSEWHERE AT WORST.
SINCE IFFY GIVEN WARMTH AND LIKELY OVERDONE NATURE WITH MODELS
WITH THE INITIAL RAINFALL...PLAN TO KEEP IN AT LEAST A VCTS
MENTION MOST SPOTS THIS AFTERNOON WITH PREVAILING MVFR TO OCNL IFR
CIGS WITHIN LIGHTER SHOWER COVERAGE. IF EARLY RAINFALL IS LESS
THEN COULD BREAK INTO A PERIOD OF VFR CIGS BEFORE ADDED CONVECTION
FILLS IN LATER IN THE DAY.
EXPECT THE MAJORITY OF THE SHRA/TSRA TO SHIFT EAST AHEAD OF THE
FRONT THIS EVENING WITH RESIDUAL SHOWERS UNDER THE TRAILING UPPER
LOW THAT WILL CROSS THE REGION OVERNIGHT. THIS FEATURE MAY KEEP
SHOWERS GOING ESPCLY KBLF/KLWB WITH DOWNSLOPE DRYING AND LOSS OF
HEATING LIMITING ADDED COVERAGE TO THE EAST WHERE WILL LEAVE OUT
ADDED SHRA MENTION AFTER EARLY THIS EVENING. OTRW OVERALL MVFR
CIGS WITH PATCHY MVFR VSBYS IN FOG IN THE WAKE OF THE EARLIER
RAINFALL.
EXTENDED AVIATION DISCUSSION...
SOME LINGERING WRAP AROUND MOISTURE ON THE BACK OF THE DEPARTING
UPPER LOW COULD KEEP ADDED SPOTTY SHOWERS AND MVFR CIGS GOING INTO
SATURDAY ESPCLY MOUNTAINS BEFORE IMPROVING LATER IN THE DAY. WEAK
HIGH PRESSURE FOLLOWS SATURDAY NIGHT INTO EARLY NEXT WEEK. HOWEVER
SOME LOWER CIGS MIGHT REDEVELOP ACROSS THE MOUNTAINS BY SUNDAY AS
LIGHT EASTERLY FLOW SETS UP UNDER ANOTHER WEAK WEDGE WHICH SHOULD
FADE BY EARLY NEXT WEEK. THE NEXT WEAK BACKDOOR COLD FRONT MAY
BRING A BAND OF SHOWERS ALONG WITH MOUNTAIN SUB-VFR ON TUESDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...KK
LONG TERM...DS/KK
AVIATION...AMS/JH/MBS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1137 PM CDT THU APR 21 2016
.UPDATE...LATE THIS EVENING INTO FRIDAY
ISSUED AT 1137 PM CDT THU APR 12 2016
SHOWERS AND THUNDERSTORMS HAVE ENDED ACROSS THE AREA WITH A FEW
SPRINKLES REMAINING. PLAN ON MAINLY DRY WEATHER THROUGH THE
OVERNIGHT WITH BREEZY NORTHERLY WINDS IN THE WAKE OF A COLD FRONT.
MOSTLY CLOUDY SKIES ARE EXPECTED THROUGH MID MORNING FRIDAY THEN
WE SHOULD SEE A MOSTLY SUNNY AFTERNOON WITH HIGH PRESSURE IN
CONTROL.
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 344 PM CDT THU APR 21 2016
AT 3 PM...SCATTERED SHOWERS WERE FOUND ACROSS CLARK COUNTY IN
NORTH-CENTRAL WISCONSIN AND NORTHEAST IOWA. BOTH OF THESE WERE
LOCATED ALONG A BAND OF 900 TO 800 MB FRONTOGENESIS. THERE WERE
REPORTS OF A WALL CLOUD AND PEA SIZE HAIL IN DAVENPORT/S FORECAST
AREA. THIS WAS OCCURRING IN AN AREA WHERE THE RAP WAS HIGHLIGHTING
THE NON SUPERCELL TORNADO PARAMETER /NST/. THROUGH 21.23Z...THE
RAP IS HIGHLIGHTING ANOTHER AREA OF NST ACROSS NORTHEAST IOWA AND
SOUTHWEST WISCONSIN. THERE IS A STATIONARY BOUNDARY IN THIS AREA.
HOWEVER THE RAP IS 5 TO 8F TOO HIGH WITH ITS SURFACE DEW
POINTS...THEREFORE...ITS CAPES ARE TOO HIGH. THIS IS LIKELY
ENHANCING THE NST VALUE TOO MUCH.
FOR THIS EVENING...THE 21.12Z AND 21.18Z MODELS CONTINUE TO SHOW
THAT BOTH OF THE 900 TO 800 MB FRONTOGENESIS BANDS WILL SLOWLY
MOVE SOUTHEAST AND WEAKEN. AT THE SAME TIME...THE SURFACE BASED
CAPES AND 900 TO 850 MB LAPSE RATES WILL BE WEAKENING. AS THIS
OCCURS...THE SHOWERS WILL RAPIDLY DISSIPATE BETWEEN 22.03Z AND
22.06Z.
ON FRIDAY MORNING...TEMPERATURES WILL DROP INTO THE MID-30S IN
TAYLOR COUNTY. WHILE THE TEMPERATURES WILL BE COOL FOR THE
POTENTIAL OF SCATTERED FROST...THERE WILL STILL BE A 2 TO 3F
TEMPERATURE-DEW POINT DEPRESSIONS AND THE SURFACE WINDS WILL BE IN
THE 5 TO 10 MPH RANGE. THIS SHOULD DETER THE DEVELOPMENT OF FROST
IN THAT AREA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 344 PM CDT THU APR 21 2016
ON FRIDAY NIGHT THERE WILL BE MOSTLY CLEAR SKIES AND LIGHT WINDS.
THIS WILL ALLOW THE LOW TEMPERATURES TO FALL INTO THE MID 30S IN
CENTRAL WISCONSIN. THIS MAY RESULT IN SOME PATCHY FROST IN THIS
AREA. WE WILL HAVE TO WATCH THIS AREA CLOSELY FOR A POTENTIAL
FROST ADVISORY.
FROM SATURDAY NIGHT THROUGH MONDAY...AN UPPER LEVEL LOW WILL MOVE
SOUTHEAST THROUGH THE REGION. ON SUNDAY AFTERNOON...THE 0-4 KM
CAPES WILL CLIMB UP TO 750 J/KG SOUTH OF INTERSTATE 90 CORRIDOR
AND THE 0-6 KM SHEAR WILL CLIMB UP TO 45 KNOTS. THIS MAY RESULT IN
THE DEVELOPMENT OF A FEW SUPERCELLS AHEAD OF THE COLD FRONT IN
NORTHEAST IOWA. WE WILL HAVE TO WATCH THIS PERIOD CLOSELY.
FROM TUESDAY NIGHT INTO WEDNESDAY...ANOTHER UPPER LEVEL LOW WILL
MOVE SOUTHEAST THROUGH THE REGION. THERE CONTINUES TO BE DEEP
SHEAR LOCATED SOUTH OF INTERSTATE 94. HOWEVER THE CAPES ARE ONLY
UP TO 500 J/KG. THIS CAPE WILL BE A LIMITING FACTOR FOR ANY THREAT
OF SEVERE WEATHER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1137 PM CDT THU APR 21 2016
A PERIOD OF MVFR CEILINGS IS EXPECTED TONIGHT IN STRATUS WITH
CLOUD BASES OF 1500 TO 2500 FT. THE STRATUS WILL THEN SHIFT SOUTH
OF THE TAF SITES BY MID TO LATE MORNING ON FRIDAY GIVING WAY TO
VFR CONDITIONS AND MOSTLY SUNNY SKIES. LOOK FOR WINDS TO BECOME
LIGHT AND VARIABLE LATE FRIDAY AFTERNOON INTO FRIDAY EVENING AS
HIGH PRESSURE BUILDS INTO THE AREA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...WETENKAMP
UPDATE...WETENKAMP
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
909 AM EDT FRI APR 22 2016
.Near Term [Through Today]...
The 7 am EDT regional surface analysis showed a cold front from
northeast MS to the coastal waters of TX. Vapor imagery and upper
air data showed a positive-tilted trough approaching from the
west. There was an MCS propagating eastward across the FL
Panhandle and Southeast AL, which the latest HRRR appears to have
initialized fairly well. This system is expected to weaken a bit
as it moves into a region with less favorable thermodynamics, but
we are still forecasting high rain chances across most of our area
this afternoon given the expected Q-G forcing and moisture ahead
of the approaching trough. Forecast max MLCAPE values will be
around 1000 J/kg, and 0-6 km bulk shear values will be in the
20-30 KT range. These levels are marginal for storm
organization/strong updrafts, but we can`t rule out a marginally
damaging wind gust.
&&
.Prev Discussion [635 AM EDT]...
.Short Term [Tonight Through Sunday]...
The frontal boundary will be clearing the area tonight with
showers and thunderstorms rapidly decreasing after sunset.
Thereafter, dry conditions will prevail through the weekend with
temperatures near to slightly above average, generally low to mid
80s for highs and upper 50s to lower 60s for lows.
.Long Term [Sunday Night Through Friday]...
A rather dry and warm pattern will dominate through next week with
weak upper level ridging in place over the southeast. Expect to
see highs in the lower to mid 80s with lows in the 60s throughout
the period.
.Aviation...
[Through 12Z Saturday] MVFR vis and/or ceilings will continue at
most TAF sites until shortly after daybreak. Otherwise, an area
of showers and thunderstorms will spread from west to east
impacting all terminals today. Convection will begin at ECP and
DHN around 12z, TLH and ABY between 17z and 18z, and VLD around
19z.
.Marine...
Generally light winds will shift to the northwest tonight behind a
cold frontal passage. Winds and seas are expected to remain on
the low side through early next week. A sea breeze is possible
near the coast on Saturday afternoon as well as Sunday afternoon.
.Fire Weather...
Aside from high dispersion values Saturday, there are no fire
weather concerns at least for the next several days.
.Hydrology...
Steady or falling river levels are expected through this weekend.
Rainfall amounts with today`s frontal system are expected to
average generally less than 1 inch for most areas with no
significant impacts on area rivers.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 82 62 85 59 86 / 70 10 10 0 0
Panama City 79 65 77 63 78 / 100 10 10 0 0
Dothan 80 58 81 57 82 / 100 30 0 0 0
Albany 79 58 81 58 83 / 80 40 0 0 0
Valdosta 83 61 83 58 83 / 70 30 10 0 0
Cross City 81 63 82 57 85 / 40 10 10 0 0
Apalachicola 80 64 80 61 78 / 60 10 10 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AL...NONE.
GM...NONE.
&&
$$
NEAR TERM...FOURNIER
SHORT TERM...DVD
LONG TERM...DVD
AVIATION...BARRY
MARINE...DVD
FIRE WEATHER...BARRY
HYDROLOGY...DVD
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
615 AM CDT FRI APR 22 2016
...AVIATION UPDATE...
.SHORT TERM...(Today and Tonight)
Issued at 300 AM CDT FRI APR 22 2016
07Z water vapor imagery showed an upper trough over IL moving to the
east and an upper low off the OR coast. In between these two lows
was an upper ridge along the Rockies. Surface obs showed a weak
ridge of high pressure gradually building south through the central
plains.
The forecast continues to call for dry weather today and tonight due
to no real forcing for precip within the upper ridge. Additionally
there should be some modest dry air advection with the surface ridge
through the day preventing any real chance for precip. There is an
area of low clouds moving south through the MO river valley. RAP and
NAM progs show these clouds should hold together long enough to move
into northeast KS this morning. Otherwise there should be good
insolation by the afternoon. Because of this and with forecast
soundings mixing the boundary layer to near 800 MB, have adjusted
highs for today up a little from the prev forecast expecting
readings between 70 and 75. The surface ridge is progged to move off
to the east tonight with winds freshening from the southeast.
Although the gradient does not appear to be all that strong.
Therefore think low lying areas may decouple with winds remaining
fairly light through the night allowing lows to fall into the mid
40s. Elevated locations may see enough wind through the night for
lows to be around 50.
.LONG TERM...(Saturday through Thursday)
Issued at 300 AM CDT FRI APR 22 2016
Only minor edits to the extended forecast with model guidance
remaining fairly similar to the previous forecast package. Upper
ridging in control with a developing sfc trough to the west Saturday
afternoon will bring gusty south winds to the CWA. Speeds between 15
and 25 mph are likely with gusts peaking at 30 to 35 mph. Gulf
moisture increases dewpoints to the 50s while highs warm back into
the upper 70s and lower 80s. Chances for thunderstorms commence
Saturday evening as a lee trough lifts eastward over the western
plains. GFS and NAM runs at 00Z continue to advertise a slightly
faster progression of the sfc low and weak upper impulse, developing
scattered showers and thunderstorms over north central Kansas
overnight. The ECMWF is slightly slower with these features with the
optimal chances arriving Mon at 12Z. Have adjusted pops accordingly,
increasing the probabilities Sunday afternoon and evening as the
upper trough axis crosses southern NE, while the sfc low and dryline
are depicted similarly over central Kansas 00Z Monday. Steepening
lapse rates and warm moist conditions ahead of the system translate
up to 2000 J/KG of sfc based CAPE with little CIN to prevent
thunderstorm development. Main uncertainty will be mesoscale in
nature such as cloud cover and morning precip which could hinder
severity of convection overnight. However, with this setup any
updraft that does form in the late afternoon will likely be severe
with speed shear up to 6 km near 40 kts. 0-1 km shear enhances with
the LLJ by 00Z as well increasing the threat for tornadoes with any
isolated convection. Otherwise large hail and damaging winds are the
most likely hazards as convection is likely to congeal into a line
as tracks over the CWA Sunday evening.
The passing frontal boundary is still hanging up over southeast
Kansas on Monday with the GFS and ECMWF generating additional
convection Monday evening near the boundary over far east central
and southeast Kansas. Enough MUCAPE and effective shear in this area
will support a few strong to severe storms.
Long term models are still advertising a possible severe weather
event for a portion of the central plains region Tuesday afternoon
and evening as a strong negatively tilted trough lifts out of the
Inter-mountain West. Main discrepancies lie with the exact position
of the frontal boundary and timing of the approaching system as the
boundary lifts northward as a warm front through the day. ECMWF is
faster with the sfc low, lifting the warm front further north
with convection, placing the boundary over northern KS and most of
the CWA within the warm sector. The GFS however is still showing the
warm front bisecting the CWA west to east by 00Z with severe
convection focusing along and north of the boundary. er north with
the dryline centered over central KS. Meanwhile the slower GFS has
been persistent with the warm front bisecting the CWA from west to
east by 00Z Monday. GFS has also been the stronger solution with
over 2000 J/KG of sfc CAPE, minimal CIN and 0-6 KM bulk shear up to
50 kts. Lower lvl shear is stronger as well, enhancing the tornado
threat. Will need to keep monitoring changes, but it does appear
likely for a few severe storms in the area and have increased precip
chances during this period.
The remainder of the extended is more uncertain as the upper low
slowly exits eastward and dry conditions return on Thursday. Next
upper trough appears slower with this package so have backed off on
pops for Thursday at this time.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday Morning)
Issued at 615 AM CDT FRI APR 22 2016
The RAP and NAM eventually caught onto the MVFR stratus moving
south from the mid MO river valley, and they hang onto the low
clouds through much of the morning. Biggest uncertainty is whether
CIGS remain at or above 1 KFT or dip below 1 KFT. Looking at OBS
upstream, there is a chance for IFR CIGS for several hours this
morning. Have the CIGS scattering out around noon based on the
RAP. Once the clouds scatter out, VFR conditions should prevail
for the rest of the period.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Wolters
LONG TERM...Bowen
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1108 AM EDT FRI APR 22 2016
.SYNOPSIS...
A COLD FRONT APPROACHES FROM THE WEST TODAY. THE COLD FRONT PUSHES
ACROSS THE AREA AND OFF THE COAST TONIGHT INTO EARLY SATURDAY
MORNING. AN UPPER LEVEL DISTURBANCE WILL DROP THROUGH THE REGION
DURING SATURDAY. HIGH PRESSURE RETURNS FOR SATURDAY NIGHT THROUGH
MONDAY. THE NEXT COLD FRONT DROPS ACROSS THE REGION TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST REGIONAL RADAR MOSAIC DEPICTS AN AREA OF SHOWERS LIFTING NEWD
INTO THE ERN VA PIEDMONT LATE THIS MORNING. THIS WELL IN ADVANCE OF
THE COLD FRONT...CURRENTLY LOCATED OVER THE OH VALLEY. AREA OF
SHOWERS MATCHES UP WELL WITH ISENTROPIC LIFT IN THE 300K SFC. MODEST
HEIGHT FALLS AND INCREASING WINDS ALOFT HAVE PROVIDED FORCING FOR
ASCENT AS THE UPPER RIDGE AXIS HAS PUSHED OFFSHORE. H85 MOISTURE
TRANSPORT HAS ADVECTED PWATS OF 1.0 TO 1.25 INCHES INTO THE REGION.
FOLLOWING HI-RES GUIDANCE (WHICH HAS VERIFIED WELL SO FAR)...EXPECT
PRECIP TO LIFT INTO CENTRAL VA AROUND NOON AND THEN POINTS EWD THRU
THE AFTERNOON. RAP SBCAPE DEPICTS LIMITED INSTABILITY OVER THE
REGION THIS MORNING...SO ONLY ANTICIPATED ISOLATED THUNDER THIS
MORNING.
BETTER FORCING ARRIVES THIS AFTERNOON AS PWATS INCREASE TO AROUND
1.2 TO 1.45 INCHES (+1 STD DEV). NAM/RAP/SREF MLCAPE REMAINS
MARGINAL AT BEST...GENERALLY AOB 750 J/KG. LAPSE RATES ALSO REMAIN
MODEST AS THE COLDEST AIR ALOFT REMAINS WEST OF THE REGION
ASSOCIATED WITH THE UPPER LEVEL FRONT. EFF SHEAR ALSO AOB 30 KT.
WITH THAT SAID...ONLY EXPECT EMBEDDED/UNORGANIZED THUNDERSTORMS. HI-
RES GUIDANCE AND NAM12 300K KEEPS THE BEST LOW LEVEL FORCING OVER
THE SOUTHEAST HALF OF THE FORECAST AREA...WHERE HIGHEST POPS WILL BE
MAINTAINED. HOWEVER...EXPECT MORE SCATTERED SHOWER ACTIVITY ACROSS
THE NW...SO HAVE TRIMMED POPS BACK INTO CHANCE RANGE. THE FRONT
PUSHES ACROSS THE REGION LATE TODAY AS ADDITIONAL UPPER LEVEL
PERTURBATIONS LIFT INTO THE REGION. EXPECT ADDITIONAL COVERAGE LATE
AFTERNOON ACROSS THE SOUTHEAST HALF OF THE LOCAL AREA. WILL RETAIN
LIKELY POPS...WITH THE NW POSSIBLY SEEING A DRYING TREND. BETTER
INSTABILITY EXPECTED MID-LATE AFTERNOON (ALBEIT STILL MARGINAL)
ACROSS THE SE...SO PERHAPS A BETTER CHANCE TO SEE THUNDER.
RETURN FLOW AND BREAKS IN THE CLOUDS WILL PUSH TEMPS INTO THE UPPER
70S TO NEAR 80 EAST OF INTERSTATE 95 (COOLER ALONG THE COAST AND
BAY). TEMPS WEST OF INTERSTATE 95 WILL LEVEL OFF IN THE LOW/MID 70S
LATE THIS MORNING THRU MID AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
WITH THE UPR LO/TROF LAGGING BEHIND THE COLD FRONT...AND PLENTY OF
LO LEVEL MOISTURE/LIFT IN PLACE...NOW HAVE LIKELY POPS EVERYWHERE
INTO TNGT. HAVE ALSO KEPT SLGT CHC OF THUNDER. LATER TNGT INTO
SAT MORNG...BULK OF PCPN WILL MOVE EWRD AND OFF THE CST AS THE UPR
LO/TROF PUSHES THE COLD FRONT ACRS THE AREA AND OFFSHR. PWATS
CLIMB TO 1.25 TO 1.5 INCHES...WHICH MAY RESULT IN PERIODS OF
MODERATE TO LOCALLY HEAVY RAINFALL. HOWEVER...QPF AMTS THRU TNGT
WILL GENERALLY RANGE FM ARND .30 INCH ACRS THE N TO NEAR .60 INCH
ACRS THE S. LOWS TNGT IN THE MID 50S TO LWR 60S.
MODEL TRENDS CONTINUE TO LINGER MID LEVEL MOISTURE TO GO ALONG
WITH THE STRONG DYNAMICS PROVIDED BY THE UPR LO DROPPING THRU THE
REGION THRU SAT AFTN. WILL HOLD ONTO SOLID CHC POPS THRU LATE
MORNG INLAND FOR SCTD SHOWERS...AND ALONG SE VA/NE NC THRU SAT
AFTN. CLOUDY CONDITIONS BECOME PARTLY CLOUDY INLAND SAT
AFTN...BUT REMAIN MOSTLY CLOUDY ALNG THE CST. TRENDED TOWARD THE
COOLER SIDE OF THE MOS GUIDANCE...DUE TO CLOUD COVER AND MODEST
CAA...BUT TEMPS REMAIN SEASONABLE IN THE UPR 60S TO MID 70S. N
WINDS GENERALLY 10 TO 15 MPH WITH GUSTS OF 20 TO 25 MPH. TROF AXIS
PUSHES WELL OFFSHORE SAT NGT...WITH DRY CONDITIONS FCST ACRS THE
AREA. LOWS IN THE MID TO UPR 40S INLAND...TO THE LWR 50S NEAR THE
CST UNDER A CLEAR OR MOSTLY CLEAR SKY. HI PRES BLDS INTO THE NE
U.S. AND TWD NEW ENGLAND SAT NGT...THEN SLIDES TO JUST OFF THE NE
U.S. AND MID ATLC CST BY 00Z MON. THE RESULT WILL BE ONGOING DRY
CONDITIONS ON SUN UNDER A MOSTLY SNY SKY. HI TEMPS WILL RANGE FM
THE MID 60S TO LWR 70S OVR MOST OF THE REGION..
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE SLIDES FARTHER OFFSHORE SUNDAY NIGHT AND MONDAY...AND
SETTLES OFF THE SOUTHEAST COAST BY TUESDAY. MEANWHILE...A SHORTWAVE
TROUGH AND AN ASSOCIATED COLD FRONT APPROACH FROM THE NW BY TUESDAY
AFTN. MONDAY AND TUESDAY ARE TRENDING TOWARD BEING VERY WARM DAYS
WITH DEEP LAYER WSW FLOW ASSOCIATED WITH A BREAKING DOWN UPPER RIDGE
OVER THE E-CENTRAL/SERN CONUS. MODEL CONSENSUS GENERALLY SUPPORTS
850MB TEMPERATURES OF 12-15C...WHICH WITH FULL MIXING AND
DOWNSLOPING SHOULD EASILY PUSH HIGHS TO 80-85F W OF THE BAY...WITH
UPPER 70S FOR THE ERN SHORE. LOWS SUNDAY NIGHT SHOULD BE IN THE
LOW/MID 50S...WITH 55-60F MONDAY NIGHT. SKY COVER SHOULD GENERALLY
BE MOSTLY CLEAR/SUNNY SUNDAY NIGHT...MONDAY INTO MONDAY NIGHT...AND
BECOME PARTLY SUNNY TUESDAY. THE TROUGH AND COLD FRONT SWING THROUGH
THE AREA TUESDAY AFTN INTO TUESDAY NIGHT. THE MAIN FORCING
ASSOCIATED WITH THE MID/UPPER SHORTWAVE TROUGH GENERALLY PASSES N OF
THE LOCAL AREA...AND DEEP LAYER RH DIMINISHES AS THE FEATURE PASSES
OVER THE LOCAL AREA SO FORECAST POPS ARE ONLY 20%...WITH A NARROW
STRIP OF 30% ACROSS THE FAR N. HIGH PRESSURE BUILDS IN FROM THE N
WEDNESDAY...AND SLIDES OFFSHORE LATER IN THE WEEK. HIGHS WEDNESDAY
SHOULD DROP BACK TO THE MID/UPPER 60S NE...TO THE MID/UPPER 70S
FARTHER INLAND...AND THEN TREND UPWARD INTO THURSDAY AS THE HIGH
SLIDES OFFSHORE. LOWS SHOULD GENERALLY BE IN THE 50S.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
LATEST SFC OBS / SAT LOOP INDICATING A QUICK INCREASE IN BKN SC
DECK BETWEEN 1.5-3K FT THIS MORNING. SHOWERS THEN MOVE SW TO NE
AFTER 16Z AS A SHORTWAVE MOVES ACROSS THE REGION WELL AHEAD OF
THE APPROACHING COLD FRONT. THUNDER POSSIBLE BUT WAS KEPT OUT OF
THIS FORECAST ISSUANCE SINCE ANY THUNDER NOT EXPECTED UNTIL AFTER
18Z. MOST LIKELY AREAS TO SEE TSTMS WILL BE ALONG AND SOUTH OF I64
WITH BEST TIMING BETWEEN 18Z-00Z. SW WIND GUST BETWEEN 15-20 KTS
AHEAD OF ANY SHOWER WITH HIGHER GUSTS POSSIBLE IN ANY TSTMS.
MODEL GUIDANCE SUPPORTS IFR CIGS DEVELOPING BY OR SHORTLY AFTER
00Z ALONG WITH REDUCED VSBYS IN RAIN/SHOWERS WITH AREAS OF FOG
LINGERING THROUGH THE NIGHT. THE COLD FRONT MOVES OFF THE COAST
EARLY SAT. TRAILING CLOSED UPPER LOW WILL CAUSE LAPSE RATES TO
INCREASE WHICH WILL CONTINUE THE POSSIBILITY FOR MVFR CIGS AND
SHOWER OR TSTM DEVELOPMENT INTO SAT. DRIER AIR AND VFR CONDITIONS
RETURN LATE SAT NIGHT.
&&
.MARINE...
TOUGH CALL WRT SCA HEADLINES TODAY AS ANY CRITERIA THAT MAY BE
MET WILL BE MINIMAL AT BEST. WILL KEEP SUSTAINED WINDS IN THE BAY
CAPPED AT 15 KT FOR NOW...ALTHOUGH OCNL GUSTS TO 20 KTS WILL BE
POSSIBLE THROUGH LATE AFTERNOON. SEAS CRNTLY 3-5 FT ACROSS MD
COASTAL WATERS (3 FT NEAR SHORE BUT 5 FT NEAR 44009) SO HAVE
ISSUED A SCA ACROSS THE MD COASTAL WATERS THROUGH 14Z WITH THE
EXPECTATION THAT SEAS OUT NEAR 20 NM DROP BELOW 5 FEET LATER THIS
MORNING. ELECTED NOT TO HAVE ANY HEADLINES FOR THE CHES BAY AND
WILL DEFER TO THE DAY SHIFT IF WINDS BECOME HIGHER THAN EXPECTED.
COLD FRONT PROGGED ACROSS THE MARINE AREA SAT MORNING. LATEST
GUIDANCE SHOWING TWO CAA SURGES...ONE SAT AFTERNOON AND ANOTHER ONE
SAT NIGHT. THE SAT AFTERNOON ONE APPEARS TO BE MARGINAL AT BEST FOR
ANY SCA HEADLINE SO WILL KEEP WINDS CAPPED AT 15 KTS ATTM. THE
SECOND CAA SURGE SAT NIGHT APPEARS TO BE A BIT STRONGER WITH WINDS
INCREASING INTO THE SCA RANGE FOR A FEW HOURS OVER THE CHES BAY.
HIGH PRESSURE BUILDS OVER THE AREA SUNDAY...SLIDES OFFSHORE
MONDAY...AND SETTLES OFF THE SOUTHEAST COAST TUESDAY.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SAM/TMG
NEAR TERM...SAM
SHORT TERM...SAM/TMG
LONG TERM...AJZ
AVIATION...MPR
MARINE...MPR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
742 AM EDT FRI APR 22 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EDT FRI APR 22 2016
WV IMAGERY AND RAP ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW INTO
THE NRN LAKES ON THE PERIPHERY OF A DEEP LOW INTO NRN HUDSON BAY.
LOW LEVEL CAA WITH NRLY WINDS INCREASED OVERNIGHT AS THE PRES
GRADIENT TIGHTENED BETWEEN HIGH PRESSURE INTO NRN ONTARIO AND TROUGH
OVER THE LOWER LAKES. CONVERGENT AND UPSLOPE FLOW INTO N CNTRL UPPER
MI COMBINED WITH LINGERING LOW LEVEL MOISTURE SUPPORTED SOME DZ/FZDZ
THAT HAS MIXED WITH LIGHT SNOW.
TODAY...EXPECT THAT THE LIGHT SNOW WILL TRANSITION TO MAINLY DZ/FZDZ
EARLY THIS MORNING AS THE DEEPER MOISTURE DEPARTS...LEAVING THE
MOIST LAYER WARMER THAN -8C. SATELLITE AND MODEL 925-900 MB RH FCST
TRENDS SUGGEST THAT THE LIGHT PCPN SHOULD DIMINISH OR END AROUND
12Z-14Z BUT THAT THE CLOUDS MAY PERSIST...MOVING OUT BTWN 15Z-18Z AS
HIGH PRESSURE WITH LOW LEVEL DRYING BUILDS IN. OTHERWISE...SUNSHINE
WITH 850 MB TEMPS NEAR -2C DURING THE AFTERNOON WILL HELP BOOST
INLAND TEMPS TO AROUND 50. OTHERWISE...NRLY FLOW OFF OF LAKE SUPERIOR
WILL LIMIT HIGH TEMPS CLOSER TO 40.
TONIGHT...ALTHOUGH WINDS WILL DIMINISH WITH THE SFC RIDGE OVER THE
AREA...MID CLOUDS MOVING IN OVERNIGHT WITH 700-500 MB WAA WILL KEEP
TEMPS FROM DROPPING OFF TOO FAR. TEMPS MAY STILL FALL INTO THE MID
20S CENTRAL AND EAST BEFORE THE CLOUDS MOVE IN. OTHERWISE...EXPECT
MIN READINGS IN THE LOWER 30S WEST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 351 AM EDT FRI APR 22 2016
LOOKS LIKE A CHILLY...ACTIVE WX PATTERN WL DOMINATE LATE THIS
WEEKEND INTO EARLY NEXT WEEK AS A VERY TIGHT BAROCLINIC ZN WL SETUP
ACRS THE UPR GREAT LKS UNDER THE CONFLUENCE ZN BTWN ARCTIC AIRSTREAM
IN CANADA AND AN ACTIVE POLAR BRANCH FLOW OVER THE NRN CONUS. SOME
MDT TO HEAVY PCPN IS LIKELY TO FALL OVER AT LEAST THE S HALF OF UPR
MI...WHICH WL BE CLOSER TO A STNRY FNT RUNNING W-E THRU THE UPR
MIDWEST. IF ENUF COLD AIR IN THE NNE FLOW BTWN BLDG HI PRES INTO NRN
ONTARIO AND THE LOWER PRES TO THE S ADVECTS INTO THE CWA AND THIS
AIR IS NOT EXCESSIVELY DRY...THERE COULD BE SOME ACCUMULATING WET SN
OVER MAINLY THE HIER TERRAIN OF NRN UPR MI ON SUN NGT INTO MON.
QUIETER BUT STILL RELATIVELY CHILLY WX WL BE THE RULE FOR MID WEEK.
SAT...UPR MI IS FCST TO BE DOMINATED BY WNW FLOW ALF BTWN UPR RDG
AXIS IN THE PLAINS AND UPR TROFFING IN ERN CANADA. ALTHOUGH MODELS
INDICATE A GOOD DEAL OF MID/HI CLDS RELATED TO WAA TO THE NE OF
SHARPENING FNT FM THE DAKOTAS INTO MN WL IMPACT THE CWA...SUSPECT
LINGERING LLVL DRY AIR ASSOCIATED WITH SLOWLY DEPARTING SFC HI PRES
WL KEEP THE CWA DRY. BEST CHC FOR SOME RAIN WL BE OVER THE NW CWA
CLOSER TO BAND OF STRONGER H7 FGEN TO THE NE OF SHARPENING FNT.
SAT NGT...MODELS IN FAIRLY GOOD AGREEMENT SHOWING MORE WIDESPREAD RA
DVLPG OVER THE CWA ESPECIALLY NEAR THE WI BORDER WITH SHARPENING
BAROCLINIC ZN/FGEN/INCRSG UPR DVGC IN RRQ OF 120KT H3 JET CORE
MOVING TO JUST S OF JAMES BAY BY 12Z SUN. WL CARRY THE HIER
CATEGORICAL POPS NEAR THE WI BORDER IN THE 06Z-12Z PERIOD.
SUN THRU MON...UPR MI IS FCST TO BE CLOSE TO SHARP BAROCLINIC ZN
UNDER CONFLUENCE ZN BTWN ARCTIC BRANCH NW FLOW DOMINATING QUEBEC AND
A WSW POLAR BRANCH FLOW OVER THE NRN CONUS. DESPITE THE UNFAVORABLE
LOOK OF THE CONFLUENT UPR FLOW WELL TO THE NE OF SHRTWV RIDING ENEWD
THRU THE NRN PLAINS WHICH WOULD TEND TO FAVOR DRY WX...MOST OF THE
MEDIUM RANGE MODELS GENERATE SOME MDT TO HEAVY PCPN OVER MAINLY THE
S HALF OF THE CWA. UPR DVGC IN RRQ OF 120KT H3 JET MAX JUST S OF
JAMES BAY AS WELL AS SHARP...PERSISTENT H85-7 FGEN N OF THE H85
WARM/STNRY FNT STRETCHING E ACRS WI FM LO IN THE NRN PLAINS AND
UNDER AXIS OF PWAT AOA AN INCH OVER THE SRN CWA LOOK TO BE THE
ENHANCEMENT FACTORS THAT WOULD OVERCOME THE UPR CONFLUENCE THAT WL
WEAKEN DISTURBANCES RIDING ENEWD TOWARD THE CWA AHEAD OF THE MAIN
SHRTWV TO THE SW. ALTHOUGH SOME OF THE COLDER MODELS` FCST SDNGS/
THERMAL FIELDS WITH H85 TEMPS AOB 0C INDICATE AT LEAST SOME OF THE
PCPN NEAR THE NRN EDGE OF THE BAND WL BE IN THE FORM OF SN...SHARP
GRADIENT IN SFC-H85 MSTR BTWN THE FNT AND CHILLY HI PRES BLDG INTO
NRN ONTARIO WL LIKELY BRING A RATHER SHARP NRN EDGE TO THE PCPN BAND
AND LIMIT THE COVERAGE OF SGNFT SN. BUT IF THE COLDER GUIDANCE IS
CORRECT AND THE LLVL DRYING IS NOT TOO AGGRESSIVE...NOT OUT OF THE
QUESTION THERE COULD BE SEVERAL INCHES OF WET...HEAVY SN OVER
PORTIONS OF THE NRN CWA MAINLY ON SUN NGT/MON MRNG AS STEADY LLVL NE
WINDS ADVECT COLDER AIR INTO THE LKS TO THE S OF THE ONTARIO HI PRES.
MON NGT THRU THU...AS THE HI PRES OVER NORTHERN ONTARIO BUILDS S
INTO THE UPR LKS UNDER CONFLUENT NW FLOW ALF BTWN UPR RDG AXIS
SHIFTING E FM THE PLAINS AND CLOSED UPR LO OVER QUEBEC...EXPECT
LINGERING PCPN TO END ON MON NGT...WITH THE HI PRES BRINGING DRY
WX/MOCLR SKIES ON TUE INTO WED. DEPENDING ON HOW QUICKLY THE QUEBEC
CLOSED LO WEAKENS AND WHETHER OR NOT THE UPR FLOW INTO THE GREAT LKS
TURNS MORE PROGRESSIVE...ANOTHER LO PRES MOVE ENE FM THE PLAINS
COULD BRING MORE PCPN TO THE AREA NEXT THU. BUT IF THE QUEBEC CLOSED
LO IS MORE RESILIENT...THAT NEXT PLAINS LO COULD BE SHUNTED TO THE
SW. EXPECT RELATIVELY CHILLY WX THRU THE EXTENDED PERIOD WITH SUB
ZERO H85 TEMPS DOMINATING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 741 AM EDT FRI APR 22 2016
EXPECT LOW CIGS TO GIVE WAY TO CLEARING BY LATE MORNING...PER
SATELLITE TRENDS AND FCST 900-925MB RH. SOME -FZDZ WILL ALSO BE
POSSIBLE AT SAW EARLY. CMX WILL CLEAR OUT EARLIEST AND IWD/SAW WITH
MORE PERSISTENT UPSLOPE FLOW SHOULD SEE CLEARING BY 14Z/16Z. HIGH
PRES BUILDING INTO THE REGION WILL BRING VFR CONDITIONS FOR THE REST
OF THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 457 AM EDT FRI APR 22 2016
NORTHERLY WINDS 15-25 KNOTS EARLY THIS MORNING ARE EXPECTED TO
DIMINISH TO 20 KTS OR LESS FRIDAY AFTERNOON THROUGH MOST OF SATURDAY
NIGHT AS A HIGH PRESSURE RIDGE CROSSES LAKE SUPERIOR. AS THE HIGH
EXITS TO THE EASTERN SEABOARD AND LOW PRESSURE DEVELOPS OVER THE
PLAINS ON SUNDAY, NORTHEAST WINDS WILL INCREASE TO 20-30 KTS SUNDAY
INTO MONDAY. THE STRONGEST WINDS WILL BE OVER WESTERN LAKE SUPERIOR
WHERE WINDS MAY APPROACH GALES AT TIMES. WINDS DIMINISH TO LESS THAN
20 KTS MONDAY NIGHT INTO TUESDAY AS HIGH PRESSURE MOVES BACK ACROSS
THE REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
525 AM MDT FRI APR 22 2016
.AVIATION...
12Z TAF CYCLE
UPPER RIDGE TO MOVE OVER NM FROM WEST TO EAST TODAY WITH FLOW
ALOFT BECOMING SWLY. MOIST LOW LEVEL SOUTHEAST WINDS TO TRANSPORT
MOISTURE UP THE RGV AND TOWARDS THE CONTDVD. MID LEVEL MOISTURE
INCREASING AS WELL...AND EXPECT ISOLD TO SCT SHRA AND TSRA TO
DEVELOP OVER THE HIGHER TERRAIN WITH GUSTS TO AROUND 40KT AFT 18Z.
MTS MAY BE BRIEFLY OBSCURED BY HEAVIER SHRA/TSRA IN WHICH
CIGS/VSBYS MAY FALL TO MVFR.
&&
.PREV DISCUSSION...333 AM MDT FRI APR 22 2016...
.SYNOPSIS...
MODEST MOISTURE CONTINUES TO WORK ITS WAY INTO CENTRAL NEW MEXICO
FROM THE SOUTHEAST AS A COUPLE OF LOW PRESSURE SYSTEMS CROSS THE
WEST COAST. THESE SYSTEMS WILL SKIRT AROUND NEW MEXICO TO THE
NORTH AND SOUTH...BUT THE MOISTURE IN PLACE WILL HELP SPARK
SCATTERED TO ISOLATED SHOWERS AND THUNDERSTORMS MAINLY OVER
CENTRAL AREAS THIS AFTERNOON AND EVENING...THEN ALONG AND TO A
LESSER EXTENT EAST OF THE CENTRAL MOUNTAIN CHAIN ON SATURDAY. THE
JET STREAM WILL MOVE OVER THE COLORADO AND NEW MEXICO BORDER ON
SATURDAY WITH SURFACE WIND GUSTS PROBABLY REACHING 50 MPH OVER A
GOOD PORTION OF NORTHERN NEW MEXICO IN THE AFTERNOON. FIRE WEATHER
CONCERNS WILL RAMP UP WEST OF THE CENTRAL MOUNTAIN CHAIN
SATURDAY...THEN CONTINUE TO PLAGUE PORTIONS OF NORTHERN AND
CENTRAL NEW MEXICO THROUGH TUESDAY AS DRIER AIR MOVES IN FROM THE
WEST AND BREEZY TO WINDY CONDITIONS RETURN DAILY.
&&
.DISCUSSION...
SOME STORMS WILL PRODUCE LITTLE OR NO RAIN WEST OF THE
CONTINENTAL DIVIDE TODAY...THEN AT LOWER ELEVATIONS BETWEEN THE
CENTRAL MOUNTAIN CHAIN AND CONTINENTAL DIVIDE ON SATURDAY.
MEANWHILE...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS
SATURDAY AFTERNOON AND EVENING IN UNION COUNTY/FAR NE NM.
A PACIFIC COLD FRONT WILL CROSS FROM THE WEST SATURDAY AND
SATURDAY NIGHT USHERING COOLER TEMPERATURES AND DRY AIR FOR
SUNDAY. READINGS WILL VARY AROUND NORMAL MOST PLACES...EXCEPT ON
THE FAR EASTERN PLAINS WHERE READINGS 4 TO 10 DEGREES ABOVE NORMAL
SHOULD PERSIST. BREEZY TO WINDY CONDITIONS ARE EXPECTED TO RETURN
IN THE VICINITY OF THE I-40 CORRIDOR OF EASTERN NM SUNDAY AFTERNOON
WITH WESTERLY DOWNSLOPE FLOW.
ANOTHER UPPER LEVEL LOW PRESSURE SYSTEM WILL DIG INTO THE GREAT
BASIN ON MONDAY...THEN PASS NORTH OF NEW MEXICO ON TUESDAY
STEERING THE JET STREAM SQUARELY OVER THE FORECAST AREA. THIS WILL
KEEP BREEZY TO WINDY CONDITIONS IN THE FORECAST ACROSS WESTERN
AREAS MONDAY AND AREAWIDE TUESDAY. IT WILL CAUSE FIRE WEATHER
CONCERNS TO PERSIST.
SHORT WAVE RIDGING WILL CAUSE WINDS TO SETTLE DOWN WEDNESDAY...BUT
SW FLOW LOOKS TO STRENGTHEN AGAIN DURING THE LATTER HALF OF THE
WEEK AS YET ANOTHER UPPER LEVEL LOW PRESSURE SYSTEM DIGS INTO THE
GREAT BASIN AND APPROACHES NM FROM THE W OR NW.
44
&&
.FIRE WEATHER...
CRITICAL CONDITIONS WILL BE AT LEAST SPOTTY SATURDAY THROUGH MONDAY
WITH MORE WIDESPREAD CRITICAL CONDITIONS POSSIBLE NEXT TUESDAY. VENT
RATES WILL BE GOOD TO EXCELLENT TODAY THROUGH NEXT WEDNESDAY.
THE LATEST MODELS QUITE CONSISTENT WITH PREVIOUS VERSIONS IN THE
SHORTER TERM. THE UPPER RIDGE WILL BE MOVING OVER NEW MEXICO TODAY
AND THEN TO THE EAST OF THE STATE SATURDAY AS AN UPPER LOW TRACKS
INTO THE GREAT BASIN AND THROUGH THE CENTRAL ROCKIES. WINDS ALOFT
WILL TRANSITION TO SOUTHWEST LATER TODAY AND TONIGHT...AND WILL
STRENGTHEN WITH TIME. LOW LEVEL MOISTURE APPEARS TO BE MIGRATING INTO
SOUTH CENTRAL NM AT THIS TIME...AND A SUSTAINED SOUTHEAST TO SOUTH
FLOW REMAINS FORECAST...WHICH WOULD BRING HIGHER DEW POINTS UP THE
RGV AND TOWARDS THE CONTDVD...AS THE GFS HAS BEEN INDICATING FOR
SEVERAL DAYS. RUC AND HRRR NOW JUMPING ONBOARD BREAKING OUT CONVECTION
ALONG THE CONTDVD AND CENTRAL MT CHAIN BY MIDAFTERNOON. WITH THE
POOR RH RECOVERIES ALONG/WEST OF THE CONTDVD AT THIS TIME...CAN/T HELP BUT
THINK THERE MAY BE SOME HIGH BASED VIRGA SHOWERS/ISOLD DRY LIGHTNING
OVER THIS AREA LATER TODAY...GIVEN THE INSTABILITY FORECAST BY THE NAM12.
CONVECTION THIS EVENING MAY RESULT IN SOME WETTING PRECIPITATION BETWEEN THE
CONTDVD AND EAST SLOPES OF THE CENTRAL MT CHAIN.
SATURDAY STILL LOOKS TO SEE WIND GUSTS TO AROUND 45 OR 50 MPH AS THE
WESTERLY WINDS SHOVE THE LOW LEVEL MOISTURE FROM WEST TO EAST OVER
THE STATE. MIN RH VALUES FALL BELOW 15 PERCENT FOR PORTIONS OF THE
MIDDLE RGV AND WEST. DECIDED TO GO AHEAD WITH A FIRE WEATHER WATCH
FOR AREAS BELOW SNOWPACK FOR THE NORTHWEST/WEST CENTRAL AND MIDDLE RGV
ALTHOUGH MAINLY FOR BERNALILLO AND VALENCIA COUNTIES IF THE GRIDS
ARE CLOSE. NOT SURE OF THE STATE OF GREENUP AT THIS TIME...BUT RECENT
COOLER WEATHER MAY HAVE RETARDED IT. HIGHS WILL BE ABOVE AVERAGE...BUT
NOT OVERLY SO...IN THE RANGE OF 5 TO 10 DEGREES.
CONVECTION WILL BE FOCUSED OVER THE CENTRAL AND EAST SATURDAY/SATURDAY
NIGHT BUT SUNDAY LOOKS TO BE DRY. THERE MAY BE A FEW SHOWERS OR STORMS
ON THE DRIER SIDE FROM THE CENTRAL MT CHAIN WWD AS THE MOISTURE BECOMES
MORE SHALLOW ON SATURDAY. RIDGETOP WINDS MAY PERSIST SATURDAY NIGHT BEFORE
RELENTING SOMEWHAT SUNDAY UNDER ZONAL FLOW...BUT NOT ENOUGH TO
ELIMINATE THE POTENTIAL FOR CRITICAL CONDITIONS IN THE EAST CENTRAL
SUNDAY AFTERNOON. RH RECOVERIES SATURDAY AND SUNDAY NIGHT WILL BE
FAIR TO POOR FOR MANY LOCALES.
MONDAY THROUGH TUESDAY WILL SEE INCREASING WINDS AS ANOTHER SYSTEM
SWINGS THROUGH THE CENTRAL ROCKIES. POOR RH RECOVERIES LOOK TO BE
WIDESPREAD MONDAY NIGHT. HIGHS WILL FALL TO AROUND 5 TO 10 DEGREES
BELOW AVERAGE WEST AND CENTRAL AND TO NEAR AVERAGE EAST BY TUESDAY...
TO HELP MODERATE THE COMBO OF WIND AND SUB 15 PERCENT RH FROM THE
MIDDLE RGV TO THE EAST CENTRAL AND NORTHEAST PLAINS TUESDAY AFTERNOON...
WHERE CRITICAL CONDITIONS LOOK TO BE WIDESPREAD. ANY WETTING PRECIPITATION
WILL BE CONFINED TO THE HIGHER TERRAIN OF THE NORTHWEST AND NORTH CENTRAL
MONDAY THROUGH TUESDAY. GUSTY WEST WINDS MAY CONTINUE TUESDAY NIGHT BEFORE
SLACKING OFF. ANOTHER SYSTEM LINED UP FOR THE END OF NEXT WEEK BUT GFS
IS DRIER AND WINDIER...THE ECMWF IS WETTER.
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING
FOR THE FOLLOWING ZONES... NMZ101-105-106.
&&
$$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1033 AM EDT FRI APR 22 2016
.SYNOPSIS...A COLD FRONT WILL MOVE SLOWLY EAST ACROSS CENTRAL NC
LATE TONIGHT THROUGH EARLY SATURDAY MORNING. HIGH PRESSURE WILL
BUILD INTO THE REGION BEHIND THE FRONT SATURDAY AFTERNOON
THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM FRIDAY...
MAIN ADJUSTMENTS THIS MORNING WERE TO RAISE POPS WHERE STEADY
SHOWERS ARE ONGOING OR IMMINENT. INCREASINGLY WARM AND MOIST SSW LOW
LEVEL FLOW IS PULLING ABOVE NORMAL PW INTO THE AREA (NEAR 1.5")...
AND DEEPENING FORCING FOR ASCENT (INCLUDING MODEST MID LEVEL
HEIGHTFALLS AND IMPROVING UPPER DIVERGENCE) AND MINOR INSTABILITY
WITH MIXING/HEATING WILL LEAD TO FURTHER DEVELOPMENT OF SHOWERS AND
ISOLATED STORMS THROUGH THE AFTERNOON... YIELDING SEVERAL HOURS OF
CATEGORICAL POPS AREAWIDE. WHILE QPF FROM THE CAMS STILL APPEARS
OVERDONE IN SPOTS... THE OVERALL TOTAL QPF APPEARS TO BE TRENDING A
BIT HIGHER THAN WAS DENOTED YESTERDAY... WITH OBSERVATIONS
INDICATING A QUARTER TO HALF INCH FOR MOST AREAS THROUGH TONIGHT
WITH LOCALLY HIGHER AMOUNTS. THE RISK OF THUNDER APPEARS MARGINAL
WITH RAP SURFACE CAPE PEAKING AT 200-500 J/KG NW TO SE... ALTHOUGH
DEEP LAYER SHEAR SHOULD BE IMPROVING IN THE EAST. WILL LEAVE IN A
MENTION OF ISOLATED THUNDER AREAWIDE... AND MONITOR CLOSELY FOR ANY
AREAS OF ENHANCED HEATING THAT MIGHT PUSH CAPE UP. OBSERVED TRENDS
AND HIGH RES GUIDANCE SHOW A SMALL TEMP CLIMB TODAY GIVEN THE CLOUDS
AND PRECIP... SO EXPECT HIGHS OF 69-78 NW TO SE. -GIH
EARLIER DISCUSSION FROM 335 AM: WATER VAPOR IMAGERY AT 07Z DEPICTS
WELL DEFINED S/W LIFTING E-NE OUT OF THE LOWER MS VALLEY. NEAR TERM
MODEL GUIDANCE HAS DECENT HANDLE ON THIS FEATURE...LIFTING IT ACROSS
OUR REGION LATER TODAY. THE APPROACH OF THIS SYSTEM INTERACTING WITH
AVAILABLE MOISTURE WILL TRIGGER SCATTERED-NUMEROUS
SHOWERS...INITIALLY OVER THE WESTERN PIEDMONT AFTER 9-10AM...AND
ACROSS THE BULK OF CENTRAL THIS AFTERNOON. MODEL GUIDANCE HAS
TRENDED DEEPER WITH THE LIFT THROUGH THE COLUMN...SUPPORTIVE OF
HIGHER RAINFALL AMOUNTS THAN SUGGESTED A COUPLE OF DAYS AGO. NOT
READY TO CLIMB ONBOARD THE GUIDANCE FROM WPC...SUGGESTING RAINFALL
TOTALS IN THE RDU AREA 1-1.33 INCHES TODAY AND TONIGHT. HAVE LEANED
TOWARD AMOUNTS GENERALLY IN THE HALF TO THREE-QUARTERS OF AN INCH
WITH POCKETS AROUND AN INCH. RAIN WILL BE WELCOMED FOR MOST FOLKS AS
MEASURABLE RAINFALL HAS NOT BEEN OBSERVED IN 8-9 DAYS. THUNDER
THREAT STILL APPEARS CONFINED TO AREAS ALONG AND EAST OF HIGHWAY 1
DURING PEAK HEATING THOUGH LOW LEVEL INSTABILITY MEAGER WITH SBCAPE
NO WORSE THAN A 1000-1200 J/KG AND MLCAPE AT OR BELOW 300 J/KG.0-6KM
BULK SHEAR INCREASES THIS AFTERNOON TO AROUND 35 KTS...SO EXPECT THE
SMATTERING OF SHOWERS THIS MORNING TO EVENTUALLY ORGANIZED INTO
BROKEN BAND OF SHOWERS BY MID AFTERNOON.
MAX TEMPS TODAY HIGHLY DEPENDENT UPON WHEN SHOWER COVERAGE
INCREASES. A DELAY IN THE ARRIVAL OF SHOWERS AT ANY ONE SPOT WILL
TRANSLATE TO WARMER HIGH TEMPS. USED A BLEND OF MOS
GUIDANCE...YIELDING MAX TEMPS LOWER 70S NW TO MID-UPPER 70S EAST-SE.
TONIGHT...MAY SEE A TEMPORARY LULL IN SHOWER COVERAGE DEVELOP LATE
IN THE DAY/EARLY EVENING AS S/W TRAVERSES ACROSS THE REGION. EXPECT
TO SEE AN UPTICK IN SHOWER COVERAGE AFTER SUNSET AS SFC COLD FRONT
ASSOCIATED WITH THE NORTHERN STREAM S/W APPROACHES/CROSSES OUR
REGION. THIS BAND OF SHOWERS SHOULD EXIT THE PIEDMONT AROUND OR
SHORTLY AFTER MIDNIGHT...AND THE COASTAL PLAIN COUNTIES PRIOR TO
DAYBREAK SATURDAY. EXPECT PARTIAL CLEARING BEHIND THE EXITING FRONT
THOUGH RESIDUAL LOW LEVEL MOISTURE COUPLED WITH A LIGHT WIND REGIME
SUGGEST A GOOD POTENTIAL FOR LOW CLOUDS TO DEVELOP ACROSS THE AREA
OVERNIGHT. MIN TEMPS MID-UPPER 50S NW-LOWER 60S SE.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 350 AM FRIDAY...
NORTHERN STREAM S/W CROSSES OVERHEAD SATURDAY. WHILE MOISTURE
BASICALLY CONFINED TO THE LOWEST 10K FEET...MID LEVEL LAPSE RATES
BETWEEN 6 AND 6.5 C/KM ALONG WITH HEATING SHOULD TRIGGER A FEW LOW
TOPPED SHOWERS IN THE LATE MORNING AND AFTERNOON HOURS. EXPECT
HIGHEST RISK FOR SHOWERS (1:4 CHANCE) OVER THE FAR NE PIEDMONT AND
THE COASTAL PLAIN. SHOWER THREAT SHOULD DIMINISH/END PRIOR TO
SUNSET.
EARLY MORNING LOW CLOUDS SHOULD LIFT INTO A SCATTERED/BROKEN DECK BY
LATE MORNING. THE PARTIAL SUNSHINE AND A RELATIVELY MILD START TO
THE DAY SHOULD ALLOW TEMPS TO RECOVER INTO THE MID-UPPER
70S...WARMEST IN THE SW WHERE MORE SUN/FEWER (IF ANY) SHOWERS
EXPECTED.
HIGH PRESSURE OVER SOUTHERN SECTIONS OF ONTARIO/QUEBEC BUILDS SWD
INTO THE SOUTHERN APPALACHIANS SATURDAY NIGHT. THIS WILL LEAD TO
CLEARING SKIES AND SLIGHTLY COOLER TEMPS. MIN TEMPS BY EARLY SUNDAY
50-55 DEGREES.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 305 AM FRIDAY...
SUNDAY THROUGH MONDAY NIGHT: MID LEVEL RIDGING WILL BUILD BACK OVER
THE AREA FOR THE SECOND HALF OF THE WEEKEND INTO EARLY NEXT WEEK.
MEANWHILE SURFACE HIGH PRESSURE... INITIALLY LOCATED OVER THE REGION
TO START THE PERIOD WILL SHIFT TO THE COAST AND THEN OFFSHORE SUNDAY
EVENING INTO EARLY NEXT WEEK. THIS WILL RESULT IN A DRY AND WARMING
FORECAST FOR THIS TIME FRAME. HIGHS SUNDAY ARE EXPECTED TO RANGE
FROM THE LOWER 70S NE TO THE UPPER 70S SW. HIGHS MONDAY SHOULD BE A
COUPLE OF CATEGORIES WARMER WITH A SOUTHERLY RETURN FLOW AROUND
OFFSHORE HIGH PRESSURE. THUS... EXPECT HIGHS ON MONDAY WILL BE IN
THE LOWER TO MID 80S. LOWS WILL FOLLOW A SIMILAR TREND... INCREASING
EACH MORNING. LOWS ARE EXPECTED TO BE IN 50S FOR MONDAY MONDAY
MORNING... AND NEAR 60/LOWER 60S ON TUESDAY MORNING.
TUESDAY THROUGH THURSDAY: THE MID LEVEL RIDGE WILL HAVE FLATTENED BY
TUESDAY MORNING AS A S/W DISTURBANCE TRACKS EASTWARD ACROSS THE
GREAT LAKES AND NORTHEAST U.S. MONDAY NIGHT INTO TUESDAY. HOW THIS
SYSTEM INTERACTS WITH THE EASTERN CANADA DEEP MID/UPPER LEVEL LOW
WILL PLAY A ROLE ON HOW FAR SOUTH THE ASSOCIATED COLD FRONT (FROM
THE S/W TRACKING EAST ACROSS THE NORTHEASTERN U.S.) MEDIUM RANGE
MODELS HAVE STRUGGLED WITH HOW FAR SOUTH THE FRONT WILL MAKE IT NEXT
WEEK. THE 00Z/22ND GFS CONTINUES TO DRIVE THE FRONT SOUTHWARD
THROUGH THE AREA TUESDAY NIGHT INTO WEDNESDAY... WHILE THE 00Z/22ND
ECMWF STALLS THE FRONT JUST TO OUR NORTH AND NORTHEAST. THUS...
CONFIDENCE REMAINS LOW FOR TEMPS TUESDAY NIGHT ONWARD AND PRECIP
CHANCES FOR TUESDAY EVENING INTO WEDNESDAY. FOR NOW WILL GO WITH
ONLY A SLIGHT CHANCE OF SHOWERS AND STORMS FROM LATE TUESDAY THROUGH
WEDNESDAY. TEMPS WILL BE GREATLY DEPENDENT BY THE PLACEMENT OF THE
FRONT... WITH LIKELY A LARGE TEMPERATURE GRADIENT NEAR THE FRONT.
REGARDLESS THOUGH... TUESDAY LOOKS TO BE WARM... WITH HIGHS IN THE
MID TO UPPER 80S. WILL FOLLOW CLOSE TO WPC AND GO WITH HIGHS
WEDNESDAY RANGING FROM THE UPPER 70S NE TO UPPER 80S SW... WITH THE
COLD FRONT BISECTING THE AREA ON WEDNESDAY MORNING. LOWS ARE
EXPECTED TO RANGE FROM THE MID TO UPPER 50S TO THE LOWER 60S.
THE NEXT COLD FRONT IS EXPECTED TO APPROACH THE AREA ON THURSDAY WITH
INCREASING CHANCES FOR SHOWERS AND STORMS... WITH HIGHS NEAR 80
NORTH TO THE MID TO UPPER 80S SOUTH... WITH THE STALLED FRONT
EXPECTED TO BE TO THE NORTH OF THE AREA BY THURSDAY.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 805 AM FRIDAY...
AVIATION CONDITIONS HAVE DETERIORATED TO MVFR WITH CEILINGS IN THE
1000-2500FT ALONG WITH POCKETS OF IFR 600-900FT CEILINGS. THE LOW
CEILINGS WILL PERSIST THROUGH 14Z-15Z THEN LIFT TO 2500-4000FT BY
EARLY AFTERNOON. SCATTERED SHOWERS AND ASSOCIATED MVFR VISIBILITIES
WILL CROSS THE TRIAD TERMINALS THROUGH 16Z SCATTERED TO NUMEROUS
SHOWERS WILL BECOME PROMINENT ACROSS THE REMAINDER OF CENTRAL NC
DURING THE AFTERNOON HOURS...PERSISTING INTO THE EVENING. FOR
NOW...THE THREAT FOR THUNDER APPEARS GREATEST IN VICINITY OF KFAY
AND KRWI DURING THE LATE AFTERNOON-EARLY EVENING HOURS WHEN LOW
LEVEL INSTABILITY IS AT ITS PEAK.
A SFC COLD FRONT WILL APPROACH FROM THE WEST TODAY...AND CROSS
CENTRAL NC LATE TONIGHT THROUGH EARLY SATURDAY MORNING. WITH THE
PASSAGE OF THE FRONT...THE NEAR SFC FLOW WILL VEER TO A WEST-NW
DIRECTION AND THE SHOWER THREAT WILL END. RESIDUAL LOW LEVEL
MOISTURE WILL LEAD TO THE FORMATION OF LOW CLOUDS LATE TONIGHT...
LINGERING INTO THE FIRST HALF OF SATURDAY MORNING. ONCE THESE CLOUDS
LIFT/DISSIPATE...VFR CONDITIONS ARE HIGHLY LIKELY FROM MID DAY
SATURDAY THROUGH MONDAY. A COLD FRONT APPROACHING FROM THE NORTH
TUESDAY WILL BRING THE NEXT THREAT FOR SUB VFR CONDITIONS TO CENTRAL
NC.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS/HARTFIELD
NEAR TERM...HARTFIELD/WSS
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1006 AM CDT FRI APR 22 2016
.UPDATE...
ISSUED AT 1006 AM CDT FRI APR 22 2016
ONCE AGAIN...NO SIGNIFICANT CHANGES WITH THIS UPDATE. MORNING
SURFACE ANALYSES REVEAL SURFACE PRESSURE FALLS BEGINNING ACROSS
EASTERN MT AND THE WESTERN DAKOTAS AS A REFLECTION OF WARM AIR
ADVECTION ALOFT. THIS IS INDUCING INCREASING SOUTHEAST FLOW AND
GIVEN UPSTREAM OBSERVED DEWPOINTS IN THE 30S TO AROUND 40 F FROM
SD INTO NEB...SOME MODEST LOW-LEVEL MOISTURE ADVECTION WILL OCCUR
THIS AFTERNOON AND EVENING. GUIDANCE...INCLUDING THE EXPERIMENTAL/
ESRL-RUN HRRR THAT HAS VERIFIED WELL LATELY...SUGGESTS HUMIDITIES
IN FAR SOUTHWEST ND WILL NOT FALL BELOW 25 PERCENT ACROSS A LARGE
ENOUGH AREA TO WARRANT ISSUANCE OF A RED FLAG WARNING.
UPDATE ISSUED AT 640 AM CDT FRI APR 22 2016
NO SIGNIFICANT CHANGE WITH THIS FORECAST UPDATE OTHER THAN TO
BLEND TO OBSERVED TRENDS THROUGH 11 UTC. WILL CONTINUE TO MONITOR
CONDITIONS ACROSS SOUTHWEST NORTH DAKOTA THROUGH THE DAY SHOULD A
RED FLAG WARNING BECOME NECESSARY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT FRI APR 22 2016
POTENTIAL NEAR CRITICAL FIRE WEATHER CONDITIONS FAR SOUTHWEST
TODAY HIGHLIGHT THE SHORT TERM FORECAST. SEE THE FIRE WEATHER
DISCUSSION BELOW FOR DETAILS.
A STATIONARY FRONT ACROSS NORTH CENTRAL THROUGH SOUTHEAST MONTANA
THIS MORNING WILL PROPAGATE EAST TODAY AS A WARM FRONT AND
APPROACH FAR SOUTHWEST NORTH DAKOTA LATE THIS AFTERNOON. AS A
RESULT...A LARGE TEMPERATURE GRADIENT IS EXPECTED ACROSS THE AREA
TODAY WITH HIGHS IN THE 50S ACROSS THE TURTLE MOUNTAINS TO NEAR 80
ACROSS THE FAR SOUTHWEST. BREEZY SOUTHEAST WINDS OF 20 TO 30 MPH
ARE EXPECTED ACROSS THE WEST THIS AFTERNOON WITH A TIGHTENING
PRESSURE GRADIENT AND ISALLOBARIC FORCING FROM PRESSURE FALLS
AHEAD OF THE WARM FRONT. GIVEN GOOD AGREEMENT...A BLEND OF THE 00
UTC GLOBAL AND HIGH RESOLUTION SUITES WERE USED...WITH PREFERENCE
GIVEN TO THE WARMER EDGE OF GUIDANCE FOR TEMPERATURES ACROSS THE
WEST PER VERIFICATION TRENDS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 302 AM CDT FRI APR 22 2016
WIDESPREAD PRECIPITATION LATE SATURDAY NIGHT THROUGH MONDAY
MORNING HIGHLIGHTS THE EXTENDED FORECAST.
THE 00 UTC DETERMINISTIC AND ENSEMBLE GLOBAL SUITES ARE IN GOOD
AGREEMENT ON THE UPPER LOW COMING ON SHORE TO CALIFORNIA AND
OREGON TODAY PROPAGATING INTO THE NORTHERN PLAINS SATURDAY NIGHT
THROUGH MONDAY MORNING. THE TREND OVER THE LAST 24 HOURS HAS BEEN
FOR A SLIGHT NORTHWARD SHIFT IN THE LOW TRACK...YIELDING MORE
WIDESPREAD AND HIGHER PRECIPITATION CHANCES ACROSS MUCH OF WESTERN
AND CENTRAL NORTH DAKOTA.
REGARDING DETAILS...SURFACE CYCLOGENESIS IS FORECAST ACROSS
WESTERN SOUTH DAKOTA SATURDAY NIGHT INTO SUNDAY MORNING WITH
RESULTING INCREASING MOISTURE TRANSPORT INTO THE REGION. WITH
STRONG DIFFLUENCE ALOFT AND STEEP MID LEVEL LAPSE
RATES...THUNDERSTORMS ARE POSSIBLE SATURDAY NIGHT INTO SUNDAY
MORNING MORNING. CERTAINLY COULD NOT RULE OUT A FEW STRONG
ELEVATED STORMS ACROSS SOUTHERN NORTH DAKOTA WITH MUCAPE OF
500-1000 J/KG AT 750 MB AND THE PRESENCE OF STRONG DEEP LAYER
SHEAR. PRECIPITATION ACROSS NORTH DAKOTA IS FORECAST TO TRANSITION
TO STRATIFORM THROUGH THE DAY ON SUNDAY AS THE SYSTEM BECOMES
NEARLY VERTICALLY STACKED ACROSS SOUTH CENTRAL SOUTH DAKOTA. AS
SUB- FREEZING LOW LEVEL AIR ADVECTS INTO THE SYSTEM SUNDAY NIGHT
INTO MONDAY MORNING...RAIN MAY TRANSITION TO SNOW WITH PERHAPS
LIGHT ACCUMULATIONS ON GRASSY SURFACES. WIDESPREAD RAINFALL TOTALS
OVER AN INCH ARE STILL FORECAST SOUTH OF US HIGHWAY 2.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 640 AM CDT FRI APR 22 2016
VFR CONDITIONS ARE EXPECTED ACROSS WESTERN AND CENTRAL NORTH
DAKOTA FOR THE 06 UTC TAF CYCLE. BREEZY SOUTHEAST WINDS WITH
GUSTS OF 25-30 KTS ARE FORECAST AT KISN AND KDIK THIS AFTERNOON.
LOW LEVEL WIND SHEAR IS POSSIBLE AT KDIK/KBIS TONIGHT.
&&
.FIRE WEATHER...
ISSUED AT 1006 AM CDT FRI APR 22 2016
NEAR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED ACROSS FAR
SOUTHWEST NORTH DAKOTA TODAY IN GOLDEN VALLEY...SLOPE...BILLINGS
AND BOWMAN COUNTIES. HIGH TEMPERATURES TODAY WILL BE IN THE UPPER
70S WITH SOUTHEAST WINDS OF 20 TO 25 MPH...GUSTING AT 30 TO 35
MPH. OF GREATEST UNCERTAINTY ARE FORECAST RELATIVE HUMIDITY
VALUES. AFTERNOON RELATIVE HUMIDITY MAY FALL INTO THE 20 TO 25
PERCENT RANGE THIS AFTERNOON...WITH EVEN LOWER VALUES POSSIBLE
ACROSS THE BORDER IN MONTANA. HOWEVER...THE LATEST INDICATIONS ARE
THAT HUMIDITY VALUES WILL NOT FALL LOW ENOUGH OVER A LARGE ENOUGH
AREA OF ANY GIVEN COUNTY TO WARRANT ISSUANCE OF A RED FLAG WARNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CJS
SHORT TERM...AYD
LONG TERM...AYD
AVIATION...AYD
FIRE WEATHER...AYD/CJS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
652 AM EDT FRI APR 22 2016
.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL APPROACH THE REGION FROM THE WEST
TODAY BEFORE PASSING THROUGH THE AREA OVERNIGHT INTO EARLY
SATURDAY. HIGH PRESSURE SHOULD BUILD IN BEHIND THIS SYSTEM LATER
SATURDAY AND REMAIN OVER THE REGION THROUGH MONDAY. THE NEXT COLD
FRONT WILL SLIDE SOUTH THROUGH THE AREA ON TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 240 AM EDT FRIDAY...
WEAKENING UPPER LOW AND ITS ASSOCIATED SURFACE COLD FRONT WILL FINALLY
PUSH EAST TODAY REACHING THE BLUE RIDGE THIS EVENING BEFORE THE FRONT
SLIDES TOWARD THE COAST TOWARD DAYBREAK SATURDAY. QUICK INCREASE IN
DEEPER MOISTURE PER SPIKE IN PWATS TO JUST BELOW 1.5 INCHES SHOULD
BRING A BIT MORE IN THE WAY OF MUCH NEEDED RAINFALL INTO THIS
EVENING. HOWEVER JUST HOW THINGS UNFOLD AND THE DEGREE OF DEEPER
CONVECTION REMAINS UNCERTAIN...ESPCLY GIVEN POTENTIAL FOR MULTIPLE
BANDS AHEAD OF THE FRONT DESPITE LACK OF DEEP INSTABILITY PER
LIMITED HEATING. LATEST MODELS DEPICT THIS WELL WITH AN INITIAL
BAND OF SHOWERS REDEVELOPING OVER THE WEST THIS MORNING ALONG AN
AXIS OF DIFFLUENCE AND DRIVEN BY WEAK SHORTWAVE ENERGY JUST AHEAD
OF THE ACTUAL FRONT. HRRR HAS THIS AXIS OF SHOWERS ALL THE WAY OUT
TO THE BLUE RIDGE THIS MORNING WHICH LOOKS OVERDONE...ALTHOUGH
OTHER SOLUTIONS VARY ON TIMING BUT TEND TO SUPPORT THIS SCENARIO.
THEREFORE TRENDED HIGHER POPS IN THAT DIRECTION EARLY ON.
ONCE THIS BAND SPREADS EAST...GUIDANCE SHOWS SOME INCREASE IN
INSTABILITY PIEDMONT ALONG ITS LEADING EDGE...AND THEN OUT WEST
AHEAD OF ANOTHER BAND OR TWO JUST AHEAD OF THE FRONT. HOWEVER
FORECAST CAPES/BULK SHEAR NOT IMPRESSIVE ESPCLY WITH INSOLATION
TEMPERED BY CLOUDS/SHRA UNLESS MODELS ARE OVERDONE AND MORE
HEATING IS REALIZED. FOR NOW WILL TREND TOWARD WESTERN SHOWER
COVERAGE EARLY...THEN HAVE MORE WIDESPREAD SHOWERS PER LIKELY OR
BETTER POPS THIS AFTERNOON ALL SECTIONS...INCLUDING MORE THUNDER
MENTION FAR WEST AND ESPCLY SOUTHEAST WHERE SHOULD GET A LITTLE
MORE HEATING. OTRW KEEPING MAINLY ISOLATED THUNDER MENTION
ELSEWHERE WHICH MAY BE GENEROUS. TRIMMED HIGH TEMPS BACK A CAT OR
SO ESPCLY WEST WHERE COULD GET STUCK IN THE LOW/MID 60S WITH ONLY
THE EAST PERHAPS 67-72 OR WARMER.
CORRIDOR OF BETTER LIFT SHOULD SPILL EAST OF THE AREA AHEAD OF THE
FRONT THIS EVENING WITH THE OPENING 5H LOW LIKELY KEEPING SOME SHOWERS
AND ISOLATED TSRA GOING MAINLY NORTH/NW ESPCLY BEFORE MIDNIGHT. OTRW
FLOW TURNING NW BEHIND THE BOUNDARY LOOKS TO CUT INTO LINGERING
SHRA ELSEWHERE...SO STEADILY REDUCING POPS AFTER 00Z WITH ONLY
20/30 POPS REMAINING FOR THE MOST PART AFTER MIDNIGHT. TOTAL QPF
LOOKS TO BE A BIT MORE PENDING COVERAGE WITHIN BANDS PERHAPS
RESULTING IN .30 TO .75 WITH THE HIGHEST AMOUNTS OVER THE SOUTH
AND WEST AT THIS POINT. COOL ADVECTION BEHIND THE FRONT RATHER
WEAK OVERNIGHT AND WITH LINGERING CLOUDS EXPECT LOWS TO REMAIN
MOSTLY IN THE UPPER 40S TO MID 50S.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 245 AM EDT FRIDAY...
AN UPPER LOW WILL DROP SOUTHEAST ACROSS THE REGION ON SATURDAY WITH
ISOLATED TO SCATTERED SHOWERS. HIGH TEMPERATURES ON SATURDAY WILL
RANGE FROM THE UPPER 50S IN THE MOUNTAINS TO THE MID 70S IN THE
PIEDMONT.
THE UPPER TROUGH WILL PUSH OUT INTO THE ATLANTIC OCEAN SATURDAY
EVENING. THIS WILL ALLOW HIGH PRESSURE TO BUILD INTO OUR REGION
SATURDAY NIGHT. LOW TEMPERATURES SATURDAY NIGHT WILL VARY FROM
AROUND 40 IN THE NORTHWEST MOUNTAINS TO THE LOWER 50S IN THE
PIEDMONT.
A 1020 MB SURFACE HIGH PRESSURE WILL BUILD ACROSS OUR AREA SUNDAY.
HIGH TEMPERATURES WILL WARM INTO THE UPPER 60S IN THE WEST TO THE
UPPER 70S IN THE EAST. UNDER MOSTLY CLEAR SKIES...SUNDAY NIGHT LOW
TEMPERATURES WILL DROP INTO THE UPPER 40S TO LOWER 50S. HIGH
PRESSURE WILL REMAINS JUST OF THE NORTH CAROLINA COAST MONDAY INTO
MONDAY NIGHT. IT WILL BE A WARM START TO THE WORKWEEK WITH HIGHS
MONDAY FROM THE MID 70S IN THE MOUNTAINS TO THE LOWER 80S IN THE
PIEDMONT. LOW TEMPERATURES MONDAY NIGHT WILL BE MILD WITH READINGS
GENERALLY IN THE MID 50S TO AROUND 60 DEGREES.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 245 AM EDT FRIDAY...
GUIDANCE OFFERS SOLUTIONS OF A COLD FRONT APPROACHING AND CROSSING
THE AREA TUESDAY INTO WEDNESDAY. HOWEVER...TIMING VARIES BETWEEN THE
GFS AND ECMWF...ALONG WITH THE EXTENT PRECIPITATION WILL REACH AND
PERSIST INTO THE FORECAST REGION.
THE UNCERTAINTY OF THE ABOVE EVENT...TIES INTO THE EVEN GREATER
UNCERTAINTY OF THE NEXT EVENT. THE COLD FRONT IS EXPECTED TO STALL
EITHER OVER...OR SOUTH OF...THE REGION FOR A BRIEF PERIOD OF TIME.
AN APPROACHING UPPER LOW/TROUGH WILL HELP SWING LOW LEVEL WINDS TO
THE SOUTHWEST WEDNESDAY INTO THURSDAY AND LIFT THE STALLED FRONT
BACK NORTH AS A WARM FRONT. AGAIN...WITH EACH SOLUTION OFFERING
DIFFERENCES IN TIMING...PRECIPITATION AMOUNTS AND EXTENT OF THE
PRECIPITATION.
OUR LATEST FORECAST WILL REFLECT A CONSENSUS OF THESE AND OTHER
SOLUTIONS BY WEIGHING HEAVILY ON THE SUPERBLEND SOLUTION. THIS
SCENARIO OFFERS A SLIGHTLY SLOWER ARRIVAL TIME OF THE PRECIPITATION
MONDAY NIGHT INTO TUESDAY...LITTLE CHANGE TO THE PRIOR WEDNESDAY
FORECAST...AND SCATTERED SHOWERS ACROSS THE AREA ON THURSDAY.
INSTABILITY LOOKS STRONG ENOUGH FOR AT LEAST ISOLATED THUNDERSTORMS
TUESDAY...WEDNESDAY...AND THURSDAY AFTERNOON.
TEMPERATURES DURING THIS PORTION OF THE FORECAST WILL TREND MILDER
THROUGH TUESDAY...AND THEN SLIGHTLY COOLER THROUGH THURSDAY.
READINGS WILL BE AROUND TEN DEGREES ABOVE NORMAL FOR THIS TIME OF
YEAR.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 640 AM EDT FRIDAY...
FLYING CONDITIONS WILL CONTINUE TO DETERIORATE THIS MORNING AS
SHOWERS CONTINUE TO MOISTEN THE COLUMN FROM WEST TO EAST AND IN
TURN ALLOWING CIGS TO FALL INTO MVFR LEVELS OR WORSE THROUGH
MIDDAY. IN ADDITION...PERIODS OF MVFR VSBYS IN RAIN/FOG WILL
OCCUR ACROSS MOST LOCATIONS AT TIMES WITH THE HEAVIER RAINFALL
ALONG THE KBLF/KLWB CORRIDOR AND LESS IN THE EAST.
LOTS OF UNCERTAINTY STILL IN REGARDS TO CIGS AND SHOWER COVERAGE
BY THIS AFTERNOON WITH MODELS WANTING TO MARCH THE EARLY BAND OF
SHOWERS EAST ACROSS KDAN/KLYH MAKING FOR LESS INSTABILITY OVER THE
REGION AHEAD OF THE ACTUAL COLD FRONT LATER IN THE DAY. THIS WOULD
TEND TO LIMIT DEEP CONVECTION TO PERHAPS THE FAR WEST WHERE MAY
SEE MORE BREAKS SOONER WITH MORE EMBEDDED NATURE TSRA ELSEWHERE AT
WORST. SINCE IFFY GIVEN CURRENT MORE WIDESPREAD COVERAGE WITH THE
INITIAL RAINFALL...PLAN TO JUST KEEP IN A VCTS MENTION MOST SPOTS
THIS AFTERNOON WITH PREVAILING MVFR TO OCNL IFR CIGS WITHIN
ADDED SHOWER COVERAGE. IF EARLY RAINFALL FADES OUT SOONER THEN
COULD BREAK INTO A PERIOD OF VFR CIGS BEFORE ADDED CONVECTION
FILLS IN LATER IN THE DAY.
EXPECT THE MAJORITY OF THE SHRA/TSRA TO SHIFT EAST AHEAD OF THE
FRONT THIS EVENING WITH RESIDUAL SHOWERS UNDER THE TRAILING UPPER
LOW THAT WILL CROSS THE REGION OVERNIGHT. THIS FEATURE MAY KEEP
SHOWERS GOING ESPCLY KBLF/KLWB WITH DOWNSLOPE DRYING AND LOSS OF
HEATING LIMITING ADDED COVERAGE OUT EAST WHERE WILL LEAVE OUT
SHRA MENTION AFTER EARLY THIS EVENING. OTRW OVERALL MVFR CIGS
WITH PATCHY MVFR VSBYS IN FOG EAST IN THE WAKE OF THE EARLIER
RAINFALL AND LINGERING LIGHT SHOWERS KLWB VICINITY OVERNIGHT.
EXTENDED AVIATION DISCUSSION...
SOME LINGERING WRAP AROUND MOISTURE ON THE BACK OF THE DEPARTING
UPPER LOW COULD KEEP ADDED SPOTTY SHOWERS AND MVFR CIGS GOING INTO
SATURDAY ESPCLY MOUNTAINS EAST TO KLYH BEFORE IMPROVING LATER IN
THE DAY. WEAK HIGH PRESSURE FOLLOWS SATURDAY NIGHT INTO EARLY NEXT
WEEK. HOWEVER SOME LOWER CIGS MIGHT REDEVELOP ACROSS THE MOUNTAINS
BY SUNDAY AS LIGHT EASTERLY FLOW SETS UP UNDER ANOTHER WEAK WEDGE
WHICH SHOULD FADE BY EARLY NEXT WEEK. THE NEXT WEAK BACKDOOR COLD
FRONT MAY BRING A BAND OF SHOWERS ALONG WITH MOUNTAIN SUB-VFR ON
TUESDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...KK
LONG TERM...DS/KK
AVIATION...AMS/JH/MBS
AREA FORECAST DISCUSSION
NWS TUCSON AZ
127 PM MST FRI APR 22 2016
.SYNOPSIS...UNSEASONABLY WARM TEMPERATURES WILL GRADUALLY DECREASE
THROUGH THE WEEKEND AS A WEAK WEATHER SYSTEM MOVES THROUGH THE AREA
TONIGHT. THIS WILL RESULT IN SLIGHTLY ABOVE NORMAL TEMPERATURES AND
BREEZY CONDITIONS. A STORM SYSTEM EARLY IN THE WEEK WILL GENERATE
GUSTY WINDS AND ANOTHER LATE IN THE WEEK WILL BRING ANOTHER ROUND OF
WINDS AND POSSIBLY A FEW SHOWERS.
&&
.DISCUSSION...
EARLY AFTERNOON SATELLITE IMAGERY REVEALS DEVELOPING CU ACROSS NEW
MEXICO...WITH EVEN A FEW DEVELOPING CLOUDS SNEAKING INTO GREENLEE
COUNTY AS OF 20Z. ASIDE FROM SOME THIN HIGH CLOUDS MOVING IN FROM
SONORA...THE REMAINDER OF THE AREA SAW CLEAR/MOSTLY CLEAR SKIES.
THIS HAS HELPED TEMPERATURES RAPIDLY RISE INTO THE LOWER 90S ACROSS
THE DESERTS.
FOR THE REST OF TONIGHT...I STILL CANNOT RULE OUT A STRAY SPRINKLE
OR SHOWER RIGHT ALONG THE AZ/NM BORDER. PAST SEVERAL RUNS OF THE UA
WRF AND THE HRRR INDICATE VERY ISOLATED COVERAGE ACROSS GREENLEE AND
EASTERN COCHISE COUNTY. I WILL HANG ONTO CLIMO-LIKE POPS IN THESE
AREAS BUT KEEP THE FORECAST DRY ELSEWHERE. MAIN THREAT WOULD BE IN
THE FORM OF DRY LIGHTNING ALTHOUGH EVEN THIS THREAT APPEARS TO BE
WANING WITH TIME.
WEAK LOW PRESSURE WILL SWEEP THROUGH THE FOUR CORNERS
TOMORROW...USHERING IN A PROLONGED PERIOD OF TROUGHING ALOFT. THIS
WILL KNOCK TEMPERATURES BACK SEVERAL DEGREES THIS WEEKEND AND WILL
ALSO BRING IN A FAIR AMOUNT OF AFTERNOON BREEZINESS. MEANWHILE A
SECONDARY LARGER TROUGH WILL MOVE THROUGH NORTHERN ARIZONA ON
TUESDAY BUT MOISTURE TRANSPORT LOOKS TO BE QUITE MEAGER AND PRECIP
CHANCES ARE ESSENTIALLY ZERO. IT WILL HOWEVER KNOCK TEMPERATURES
DOWN A BIT MORE WITH READINGS GENERALLY FORECAST TO BE 10 DEGREES
BELOW NORMAL FOR LATE APRIL. A THIRD TROUGH IS FORECAST TO ARRIVE
LATE IN THE WEEK. STILL SOME DIFFERENCES IN THE DETERMINISTIC
GUIDANCE WITH RESPECT TO EXACT TIMING AND TRAJECTORY. NAEFS
INDICATING 10-20 PERCENT CHANCES AREA-WIDE LATE NEXT WEEK AND THIS
SEEMS LIKE A MORE THAN REASONABLE STARTING POINT.
&&
.AVIATION...VALID THRU 24/00Z.
SCT TO OCCASIONALLY BKN THIN CIRRUS AOA 25K FT AGL INTO EARLY
SATURDAY WITH SKIES GENERALLY BECOMING SKC AFTER 23/18Z. SWLY WIND
10-20 KTS THIS AFTERNOON WITH GUSTS UP TO 25 KTS POSSIBLE. WINDS
WILL TAPER OFF AFTER 23/03Z BECOMING LIGHT AND TERRAIN DRIVEN THRU
23/17Z...THEN SW WINDS INCREASING AGAIN. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A FEW BUILDUPS THIS AFTERNOON RIGHT ALONG THE NEW
MEXICO BORDER WHERE SOME INCREASED MOISTURE HAS MOVED IN. ANY
SHOWERS OR THUNDERSTORMS THAT DEVELOP WILL MOSTLY REMAIN TO THE EAST
OF THE AREA BUT CAN`T RULE OUT SOME GUSTY WINDS AND THE POTENTIAL
FOR A DRY LIGHTNING STRIKE OR TWO WITH ANY STORMS THAT DEVELOP ALONG
THE NEW MEXICO BORDER. ANY RESIDUAL MOISTURE WILL QUICKLY BE SWEPT
BACK TO THE EAST SATURDAY AS WESTERLY FLOW INCREASES WITH A TROUGH
OF LOW PRESSURE PASSING TO THE NORTH OF THE AREA. THIS THROUGH WILL
ALSO RESULT IN SLIGHTLY COOLER TEMPERATURES AND SOME INCREASED
BREEZES BOTH SATURDAY AND SUNDAY AFTERNOON. WIND SPEEDS WILL
GENERALLY REMAIN BELOW CRITICAL THRESHOLDS...BUT WILL REMAIN CLOSE
FOR EASTERN AREAS OF COCHISE COUNTY WHERE BRIEF LOCALIZED RED FLAG
CONDITIONS ARE POSSIBLE.
ANOTHER DRY SYSTEM WILL MOVE IN PRODUCING GUSTY WINDS EARLY NEXT
WEEK WITH COOLER TEMPERATURES ESPECIALLY ON TUESDAY. THERE IS A
POTENTIAL FOR MORE WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS TO BE
MET MONDAY AND TUESDAY AFTERNOON ACROSS AREAS PRIMARILY SOUTH AND
EAST OF TUCSON. THIS IS SOMETHING WE`LL BE WATCHING CLOSELY OVER THE
NEXT FEW DAYS AS WE ASSESS THE POSSIBLE NEED FOR FIRE WEATHER
HEADLINES. BREEZY AFTERNOON WINDS WILL LIKELY CONTINUE WEDNESDAY AND
THURSDAY BUT REMAIN BELOW CRITICAL LEVELS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
318 PM PDT FRI APR 22 2016
.SYNOPSIS...
The possibility of precipitation will end this evening, then a
high will build in over the weekend for breezy winds and a slight
warmup. a series of lows should then arrive next week for around
normal temperatures, with possible precipitation late next week.
&&
.SHORT TERM...(TDY-MON)
A weak cold front was moving into the Central Coast this afternoon,
with rainfall amounts in nwrn SLO County less than 0.10 inch along
the coast, and about 0.20 to 0.40 inch in the coastal mtns. Rocky
Butte has had 0.43 inch as the front went thru. Mostly cloudy skies
accompany the front, with mostly sunny skies over VTU/L.A. Counties
this afternoon. Onshore pressure gradients have increased to +7.7 mb
LAX-DAG and +13.6 LAX-TPH as of 21Z. These strong pressure gradients
have been driving strong and gusty sw winds thru the Antelope Vly
this afternoon, with gusts over 40 mph in a few spots. Gusts in this
area may locally reach 50 mph especially on the west side this
afternoon and evening. These winds should cause patchy blowing dust
with visibilities possibly down to one quarter mile or less at
times. A wind advisory is in effect for this area. For the mtns,
foothills, and SLO/SBA County coast and some interior vlys, s to w
winds have increased to 15 to 25 mph with gusts to 35 mph over a
large area. Temps this afternoon will top out in the 70s to around
80 for many coastal and vly areas.
An upper level trof over central and nrn CA today will move e
tonight and Sat. Weak upper level ridging will gradually move into
the area on Sat and linger Sat night. An upper level trough will
move into the area for Sun. Swrn CA will be on the srn fringes of a
broad upper level trof over e central CA into NV Sun night and Mon,
with a broad nw flow aloft over the fcst area.
The cold front is forecast to dissipate this evening with a slight
chance of showers lingering for portions of SLO/SBA Counties, and
the slight chance of showers on the n slopes later tonight.
Otherwise, partly cloudy skies overall can be expected across the
region overnight. Gusty onshore winds will prevail along the Central
Coast, foothills, mtns and deserts this evening. Winds will turn
more nw to n tonight, with gusty winds expected in the mtns along
the I-5 corridor, and the SBA County mtns and s coast. The 12Z NAM
was predicting 850 mb winds to peak around 35 KT near the I-5
corridor and SBA County mtns tonight. Advisory level winds with
gusts to 40 to 50 mph will continue tonight in the Antelope Valley,
and develop in the L.A./VTU/SBA County mtns and SBA County s coast
this evening and persist into early Sat, except thru early Sat
evening in the L.A./VTU mtns. As a result, wind advisories are also
in effect for the mtns and SBA s cst. Please see the latest non-
precipitation weather message for further details on the wind
advisories currently in effect.
There may be a few lingering clouds early Sat, otherwise
increasingly sunny skies can be expected for the bulk of the day on
Sat. Gusty nw winds are expected along the Central Coast, in the
mtns along the I-5 Corridor, and in the Antelope Vly for Sat
afternoon and evening, and in the SBA County mtns and s cst Sat
night into early Sun. Additional wind advisories may be needed in
some of these areas as well.
Partly cloudy skies at times can be expected Sat night thru Mon as
the upper trof moves in. Clouds should once again bank up on the n
mtn slopes with a slight chance of rain or snow showers later Sun
night into Mon morning. 12Z NAM boundary lyr moisture fields were
also suggesting some low clouds and fog should develop in the
Salinas River Vly later Sun night into Mon morning. Another increase
in the onshore gradients can be expected both Sun and Mon afternoon
and evening, with gusty nw winds mainly along the Central Coast, SBA
County s cst, and in the foothills, mtns and Antelope Vly. Wind
advisory level winds will be likely at times Mon afternoon and
evening in these areas, except the Central Coast may approach
advisory levels.
Temps are forecast to warm slightly back to near normal to slightly
above normal for most areas on Sat, with little change expected for
Sun and Mon.
.LONG TERM...(TUE-FRI)
The EC/GFS are in generally good agreement with the large scale
features during the period, with only minor differences by Thu and Fri.
The upper trof extending into e central CA will move well e of the
region on Tue. Upper level troffiness will move back in from the e
Pac on Wed. A cold upper level low off the central CA cst Wed will
move se and into swrn ca on Thu, then move e of the region Thu night
and Fri.
Dry weather with breezy to windy onshore flow for the afternoon and
evening hours will continue Tue thru Wed. The GFS is more robust
with the extent of the upper low off the coast Thu compared to the
EC, and the GFS is a bit wetter than the EC for Thu. There is enough
of an increase in confidence for unsettled conditions so have
increased pops to chance levels across the forecast area Wed night
and Thu. Residual moisture and upper troffiness for Thu night into
Fri has prompted a slight chance of showers to remain in the fcst to
end the work week. If the GFS verifies with the position of the
upper low on Thu, then there would be the potential for thunderstorm
development over the area with locally heavy rainfall. This
situation will be closely monitored over the next several model
runs, but since this potential weather event is still six days away,
will not add the mention of thunderstorms just yet.
Temps will be generally near normal or slightly below normal Tue and
Wed, cool to several deg below normal for Thu, then warm slightly
Fri but still remain slightly below normal overall.
&&
.AVIATION...22/1800Z...
Mid/upper level trough of low pressure over Northern California
will shift east while a mid/upper level ridge of high pressure
over the Eastern Pacific moves over the area. Upper level
strong northwest winds will become moderate west-northwest after
23/22z and mid level moderate west winds will become moderate
northwest after 23/07z. Surface trough of low pressure and low
cloud field approaching the Central Coast will dissipate and mix
out today. Weak to moderate onshore pressure gradient will become
moderate northerly gradient between 23/05-23/17z then mixed
moderate onshore and moderate northerly gradient thereafter.
Marine inversion base was unorganized and varied from near the
surface and 5kft along the central coast to 1.7kft over KLAX this
morning with a scattered cloud field. The inversion is expected to
mix out today and not redevelop Saturday morning.
Marine layer at LAX at 1600Z is 1688 feet deep and the inversion
top is at 5431 feet with a temp of 12.1 degrees C.
KLAX...Few low clouds will dissipate through 22/19z then it is very
likely no low/mid level cigs and/or vsby below 6sm through the
period.
KBUR...Very likely current sky/vsby conditions will prevail.
virtually certain - 95-100%
very likely - 80-95%
likely - 60-80%
chance - 30-60%
very unlikely - 20% OR LESS
&&
.MARINE...22/200 pM...
There is a chance small craft advisory conditions will exist in
the vicinity of the Northern Channel Islands to San Mateo Point this
afternoon through this evening. Northwest winds will likely
increase Saturday in the vicinity of the Channel Islands and over
the entire area Sunday and there is a chance gale force winds will
exist Saturday afternoon in the vicinity of the Channel Islands
and over the entire area at times Sunday afternoon through Monday
night. Otherwise seas currently in the Eastern Pacific and
oriented 290-310 degrees relative to Ventura coast will arrive
through Saturday morning and there is a chance small craft
advisory for hazardous sea conditions will exist from Piedras
Blancas to San Clemente Island Saturday through Sunday morning. A
storm force wind fetch is expected to develop in the Southern
Ocean and oriented 190-180 degrees to Ventura County Saturday.The swells
that will begin to arrive next week Saturday and probably
generate hazardous surf and extra currents and surging along
exposed south facing shores Saturday night through Monday.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect from 8 PM this evening to 8 AM PDT
Saturday For zones 39-52. (See LAXNPWLOX).
Wind Advisory in effect from 8 PM this evening to 8 PM PDT
Saturday For zones 53-54. (See LAXNPWLOX).
Wind Advisory in effect until 8 AM PDT Saturday For zone 59. (See LAXNPWLOX).
PZ...Gale Watch in effect from Sunday afternoon through late
Monday night For zones 645-670-673-676. (See LAXMWWLOX).
Small Craft Advisory in effect until 1 AM PDT Saturday For
zones 650-655. (See LAXMWWLOX).
Gale Watch in effect from Sunday evening through Monday
evening For zones 650-655. (See LAXMWWLOX).
Small Craft Advisory in effect until 3 PM PDT Sunday For
zones 670-673-676. (See LAXMWWLOX).
&&
$$
PUBLIC...Sirard
AVIATION...30
MARINE...30
SYNOPSIS...Seto
weather.gov/losangeles
[top]
Area Forecast Discussion
National Weather Service Reno NV
303 PM PDT FRI APR 22 2016
.SYNOPSIS...
A strong Pacific storm will continue to move through the Sierra
and Western Nevada tonight. Rain and heavy mountain snow are
expected this evening near and south of I-80. A break is expected
Saturday before more showers are expected Sunday into Monday with
another system. Unsettled weather will continue through next week
with below average temperatures.
&&
.SHORT TERM...
A strong spring storm continues to move through. Heavy snow is
falling in the Sierra with rates approaching 3"/hr. It is best to
avoid travel in the Sierra for the next few hours if possible.
Heavy convective snowfall continues in the Sierra with the bands
extending from Westwood south into Bridgeport. Heavy snow is
falling above 6000 feet, with the snow level locally down to 4500
feet in the heaviest bands. Latest satellite/radar trends support
the HRRR in keeping the heaviest rain/snow going thru 03Z near and
south of I-80. After there will be a rapid reduction in showers as
the upper forcing moves east and the airmass stabilizes.
Until then, another 6+ inches of snow is possible above 7000 feet
with another 2-4" down to 5500-6000 feet. Rainfall into Western NV
will be heaviest in the Sierra front where an additional 1/4" of
rain is possible. It may mix with snow at times in the foothills
while lighter amounts are expected toward the highway 95 corridor.
Winds are much weaker along the Sierra Front with the precip
falling, but strong gusts continue east of a Bridgeport to
Lovelock line. Will cancel the advisory for Reno-Carson-Minden,
but leave the remainder as the winds continue there.
Behind this storm, a break is expected Saturday with continued
cool temps, but lighter winds and dry conditions. Another upper
low is expected Sunday afternoon into Monday. Showers are expected
Sunday afternoon with enough instability for a few thunderstorms
as well. The core of the low will move overhead Monday morning
with much colder air. Snow levels will fall to near the valley
floors. While this storm will have some moisture with it, the best
forcing is expected to remain over Eastern NV so we are not
expecting another big precip event. However, there remains a
threat (low at this time) of some light snowfall during the Monday
morning commute along the I-80 and highway 50 corridors. Wallmann
.LONG TERM...Monday Night through Friday...
Unsettled weather pattern is expected to continue through next
week as late season storm systems line up to move into the West
Coast. Wednesday-Friday could be a rather wet period for much of
the region with potential for additional snow in higher
elevations.
For Monday night, the first upper low is likely to be on its way
out with lingering rain and snow showers diminishing. Tuesday
still looks like the least active weather day, although a few
showers remain possible as residual moisture will remain in place.
Even though temperatures are expected to increase about 10-15
degrees from Monday, highs in the lower 60s and around 50 degrees
near the Sierra will still be a few degrees below average for late
April.
For next Wednesday-Friday, medium range guidance continues to
indicate a potent low pressure tracking southward along the
California coast, then swing inland across the southwest US (or
possibly farther north into eastern NV). Despite this southerly
track, a broad area of upper divergence and instability is
projected to set up over the Sierra and western NV, along with a
decent tap of Pacific moisture. A few thunderstorms are also
possible each afternoon, although the better instability looks to
be trending north of I-80 by next Friday. Current projections
favor the best overall rain and snow chances Wednesday night and
higher thunderstorm potential on Thursday, but this could vary
depending on the eventual storm track. Widespread cloud cover will
keep daytime temps a few degrees below average each day, with
nighttime temps slightly above average. Early snow level
projections generally range from 6000-7000 feet in the Sierra,
although these snow levels could occasionally drop several hundred
feet during convection or heavier precip bands. MJD
&&
.AVIATION...
The most significant weather effects on aviation will continue
through this evening with IFR/LIFR cigs/vsby in snow near the
Sierra including KTVL/KTRK/KMMH, and a few inches of snow
accumulating on pavement. For lower elevations including KRNO-
KCXP, rain will produce MVFR cigs/vsby with mountain obscurations,
IFR at times during heavier rain bands. The strongest winds have
ended at KRNO-KCXP but some gusts to 35 KT remain possible. KMMH
may receive stronger gusts above 40 KT until 03z.
Later tonight, if cloud cover breaks up sufficiently, areas of
FZFG would develop across many Sierra valleys around Tahoe and
northeast CA, including KTRK. For Saturday, generally VFR
conditions are expected with lighter winds. MJD
&&
.REV Watches/Warnings/Advisories...
NV...Winter Weather Advisory until 11 PM PDT this evening NVZ002.
Wind Advisory until 8 PM PDT this evening NVZ001-004.
CA...Winter Weather Advisory until 5 PM PDT this afternoon above 5500
feet in CAZ071.
Wind Advisory until 8 PM PDT this evening CAZ073.
Winter Weather Advisory until 11 PM PDT this evening CAZ072.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
230 PM PDT FRI APR 22 2016
.SYNOPSIS....A FEW SHOWERS WILL LINGER INTO THE EVENING HOURS
BEFORE DRIER CONDITIONS DEVELOP TONIGHT. DRY WEATHER IS EXPECTED
ALONG WITH SEASONABLY COOL TEMPERATURES THIS WEEKEND. A LOW
PRESSURE SYSTEM DROPPING INTO THE INTERIOR WILL BRING A SLIGHT
CHANCE OF SHOWERS FOR THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...AS OF 02:50 PM PDT FRIDAY...IN THE NEAR TERM ACTIVE
WEATHER CONTINUES AS A COLD FRONT CONTINUES TO THE MOVE THROUGH
THE REGION. THE FRONTAL PASSAGE THIS AFTERNOON BROUGHT MODERATE TO
LOCALLY HEAVY RAIN SHOWERS TO PORTION OF THE BAY AREA. THERE ARE
SOME DECENT SIX HOUR RAINFALL TOTALS...OVER ONE INCH NEAR PALO
ALTO AND SAN MATEO. OTHER HIGH SPOTS INCLUDE PORTIONS OF THE BIG
SUR COAST...UP TO ONE INCH AND MANY OTHER LOCATIONS ONE HALF INCH
TO THREE QUARTERS OF AN INCH. NOT A DROUGHT BUSTER...BUT MUCH
NEEDED RAINFALL NON THE LESS. THERE WAS EVEN ONE REPORT OF SMALL
HAIL NEAR HEALDSBURG.
THIS AFTERNOON INTO THIS EVENING...SHOWERS WILL STILL BE POSSIBLE
WITH THE GREATEST LIKELIHOOD FROM SAN JOSE SOUTH. HAVE NOT
RECEIVED ANY REPORTS OF THUNDER OR NOTICED LIGHTNING ON THE
DETECTION NETWORK...BUT GIVEN DAYTIME HEATING AND UNSTABLE
AIRMASS WILL KEEP THE MENTION OF THUNDERSTORMS THROUGH LATE THIS
AFTERNOON. BY LATE THIS EVENING...EXPECT PRECIP CHANCES TO
DIMINISH RATHER QUICKLY...ESPECIALLY POST SUNSET. LATEST HRRR
MODEL CONCURS AND SHOWS LITTLE IN THE WAY OF PRECIP AFTER 03Z.
FOR THE UPCOMING WEEKEND...DRY CONDITIONS DEVELOP AS RIDGING
OCCURS OVER THE REGION. THE RIDGE WEAKENS BY SUNDAY AS ANOTHER
LOW PRESSURE MOVES INTO INTERIOR CALIFORNIA. ANY RAIN LOOKS TO
REMAIN NORTH AND EAST OF THE BAY AREA AT THIS TIME. HOWEVER...ONE
IMPACT FOR THE BAY AREA WILL BE THE WINDS. NORTHERLY WINDS WILL
INCREASE 15 TO 25 MPH WITH STRONGER GUSTS OVER 30 MPH. AT THIS
TIME IT IS BORDERLINE FOR A WIND ADVISORY.
THE 12Z MODEL GUIDANCE STILL SHOWS LOTS OF UNCERTAINTY FOR THE
MIDDLE OF NEXT WEEK REGARDING RAIN CHANCES. MEDIUM RANGE MODELS
STILL INDICATE A SPREAD IN SOLUTIONS...BUT AT LEAST THEY ALL SHOW
A LOW PRESSURE SYSTEM MOVING OVER THE REGION. THE DETAILS ON THE
THE OTHER HAND VARY. GIVEN THE LOW CONFIDENCE WILL CONTINUE WITH A
SLIGHT CHANCE FOR SHOWERS.
&&
.AVIATION...AS OF 10:45 AM PDT FRIDAY...CURRENTLY TRYING TO TIME
THE RAIN ACROSS THE VARIOUS TERMINALS. EARLY RUNS OF THE HRRR DID
NOT INITIALIZE WELL SO USING IT WITH SOME CAUTION FOR THE LATEST
PACKAGE. IN GENERAL LOOK FOR MVFR TO VFR CIGS WITH RAIN SHUTTING
OFF NORTH TO SOUTH STARTING AROUND 0Z...OR POSSIBLY A BIT EARLIER.
WILL BE KEEPING A CLOSE EYE ON RADAR AND LIGHTNING PRODUCT AS
HEATING DURING THE DAY COULD TRIGGER A FEW THUNDERSTORMS. WINDS
FORECAST TO BECOME MORE 260 TO 290 LATER IN THE DAY BEHIND THE
COLD FRONT. RETURN TO VFR FOR TOMORROW. MODERATE CONFIDENCE.
VICINITY OF KSFO...-SHRA EXPECTED AT LAST THROUGH 0Z AND POSSIBLY
AN HOUR OR TWO LONGER. CIGS GENERALLY WILL STAY AT OR ABOVE 030
THROUGH THE PERIOD. WINDS FROM 220 TO 240 WILL REMAIN OVER 20 KT
WITH OCCASIONAL GUSTS TO 30 KT. WINDS AROUND 220 BECOME MORE 260
TO 280 AROUND 02Z. IMPROVING CONDITIONS AFTER 09Z WITH VFR
FORECAST FOR TOMORROW. MODERATE CONFIDENCE.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY TERMINALS...-SHRA FORECAST TO RETURN AROUND 19Z WITH
POTENTIAL FOR SHRA OR EVEN +SHRA ALONG WITH MVFR CIGS. SHOWERS
END AFTER 03Z WITH VFR FORECAST BEYOND THAT POINT. WINDS FORECAST
TO BECOME MORE 230 TO 260 WITH SPEEDS OVER 12 KT LATER IN THE
AFTERNOON. MODERATE CONFIDENCE.
&&
.MARINE...AS OF 01:57 PM PDT FRIDAY...NORTHWESTERLY WINDS BEHIND A
DEPARTING COLD FRONT WILL SLOWLY DIMINISH TONIGHT. A SECOND COLD
FRONT WILL DROP THROUGH THE WATERS WITH INCREASING NW WIND AND
SEAS SUNDAY THROUGH EARLY NEXT WEEK. GALE FORCE WINDS ARE POSSIBLE
FOR SUNDAY NIGHT IN OUR OUTER WATERS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...SF BAY UNTIL 9 PM
SCA...PT ARENA TO PT REYES 0-10 NM UNTIL 9 PM
SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 9 PM
SCA...PT ARENA TO PIGEON PT 10-60 NM UNTIL 9 PM
&&
$$
PUBLIC FORECAST: MM
AVIATION: BELL
MARINE: BELL
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1050 AM PDT FRI APR 22 2016
.SYNOPSIS....A COLD FRONT WILL SLIDE ACROSS THE FORECAST AREA
TODAY BRINGING THE POSSIBILITY OF A WET MORNING COMMUTE FOR THE
SAN FRANCISCO BAY AREA. SHOWERS WILL LINGER INTO THE EVENING HOURS
WITH A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS. THE BEST
POSSIBILITY OF THUNDERSTORMS WILL BE FROM SAN JOSE NORTHWARD.
DRY WEATHER IS EXPECTED ALONG WITH SEASONABLY COOL TEMPERATURES
THIS WEEKEND. A LOW PRESSURE SYSTEM DROPPING INTO THE INTERIOR
WILL BRING A SLIGHT CHANCE OF SHOWERS FOR THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...AS OF 09:29 AM PDT FRIDAY...MAIN FOCUS TODAY WILL
BE IN THE NEAR TERM AND LATE THIS AFTERNOON. CURRENT SITUATION HAS
A COLD FRONT MOVING THROUGH THE BAY AREA AS OF THIS WRITING. THE
FRONTAL BOUNDARY HAS BROUGHT WIDESPREAD PRECIP TO THE BAY
AREA...SOME OF IT MODERATE TO LOCALLY HEAVY AT TIMES. A PUBLIC
INFORMATION STATEMENT HAS BEEN ISSUED WITH RAINFALL TOTALS. SINCE
LAST NIGHT...RAIN WAS HEAVIEST OVER THE NORTH BAY WITH OVER ONE
INCH AT MT SAINT HELENA. OTHER NOTABLE AMOUNTS ACROSS THE NORTH
BAY WERE GENERALLY IN THE ONE HALF INCH TO THREE QUARTERS OF A
INCH. LOCATIONS SOUTH OF THE GOLDEN GATE WERE GENERALLY LESS AND A
FEW TENTHS TO A LITTLE OVER ONE HALF INCH. LATEST KMUX IMAGERY
CONTINUES TO SHOW RADAR ECHOES ACROSS THE BAY AREA WITH A FEW
EMBEDDED MODERATE TO HEAVY SHOWERS. PER THE NEARBY
PROFILERS...FREEZING LEVELS ARE 4500-5000 FEET. THE STRONGER CELLS
MAY INCLUDE SMALL HAIL.
AS THE FRONT CONTINUES TO MOVE SOUTH PRECIP COVERAGE WILL
GRADUALLY DIMINISH. HOWEVER...LATEST MODELS CONTINUE TO INDICATE
A SECOND ROUND OF SHOWERS POSSIBLE THIS AFTERNOON. IN FACT...THERE
WILL BE A GREATER LIKELIHOOD FOR THUNDERSTORMS THIS
AFTERNOON...MAINLY NORTH OF SAN JOSE. DAYTIME HEATING WITH COLD
AIR ALOFT WILL LEAD TO AN UNSTABLE AIRMASS. WILL HAVE TO KEEP AN
EYE ON THE RADAR WITH POSSIBLE THUNDERSTORMS.
NO UPDATE IS PLANNED AT THIS TIME...BUT WILL BE MONITORING THE
CURRENT WEATHER SITUATION AND ADJUSTING AS NEEDED.
&&
.PREV DISCUSSION...AS OF 2:55 AM PDT FRIDAY...A WEAK RIDGE OF
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT TONIGHT INTO SATURDAY
PROVIDING DRY WEATHER THROUGH AT LEAST SATURDAY. THE RIDGE BREAKS
DOWN SUNDAY AS A STORM SYSTEM PUSHES INTO THE PACIFIC NORTHWEST
WHICH WILL HELP TO MAINTAIN COOL DAYTIME TEMPERATURES THROUGH
MONDAY. FORECAST CONFIDENCE BEGINS TO DIMINISH MIDWEEK AS THE
FORECAST MODELS MOVE ANOTHER LOW PRESSURE SYSTEM THROUGH THE AREA
WHICH MAY PROMOTE A POSSIBILITY OF SHOWERS ON WEDNESDAY AND
THURSDAY...POSSIBLY EVEN NEXT FRIDAY.
&&
.AVIATION...AS OF 10:45 AM PDT FRIDAY...CURRENTLY TRYING TO TIME
THE RAIN ACROSS THE VARIOUS TERMINALS. EARLY RUNS OF THE HRRR DID
NOT INITIALIZE WELL SO USING IT WITH SOME CAUTION FOR THE LATEST
PACKAGE. IN GENERAL LOOK FOR MVFR TO VFR CIGS WITH RAIN SHUTTING
OFF NORTH TO SOUTH STARTING AROUND 0Z...OR POSSIBLY A BIT EARLIER.
WILL BE KEEPING A CLOSE EYE ON RADAR AND LIGHTNING PRODUCT AS
HEATING DURING THE DAY COULD TRIGGER A FEW THUNDERSTORMS. WINDS
FORECAST TO BECOME MORE 260 TO 290 LATER IN THE DAY BEHIND THE
COLD FRONT. RETURN TO VFR FOR TOMORROW. MODERATE CONFIDENCE.
VICINITY OF KSFO...-SHRA EXPECTED AT LAST THROUGH 0Z AND POSSIBLY
AN HOUR OR TWO LONGER. CIGS GENERALLY WILL STAY AT OR ABOVE 030
THROUGH THE PERIOD. WINDS FROM 220 TO 240 WILL REMAIN OVER 20 KT
WITH OCCASIONAL GUSTS TO 30 KT. WINDS AROUND 220 BECOME MORE 260
TO 280 AROUND 02Z. IMPROVING CONDITIONS AFTER 09Z WITH VFR
FORECAST FOR TOMORROW. MODERATE CONFIDENCE.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY TERMINALS...-SHRA FORECAST TO RETURN AROUND 19Z WITH
POTENTIAL FOR SHRA OR EVEN +SHRA ALONG WITH MVFR CIGS. SHOWERS
END AFTER 03Z WITH VFR FORECAST BEYOND THAT POINT. WINDS FORECAST
TO BECOME MORE 230 TO 260 WITH SPEEDS OVER 12 KT LATER IN THE
AFTERNOON. MODERATE CONFIDENCE.
&&
.MARINE...AS OF 10:45 AM PDT FRIDAY...SOUTH TO SOUTHWESTERLY
WINDS WILL CONTINUE TO SLIGHTLY INCREASE TODAY AS A COLD FRONT
MOVES TOWARD OUR REGION. WINDS WILL BECOME NORTHWEST LATER TODAY
INTO TONIGHT BEHIND THE DEPARTING FRONT. A DRY COLD FRONT WILL
DROP THROUGH THE WATERS WITH INCREASING NW WIND AND SEAS SUNDAY
THROUGH EARLY NEXT WEEK.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT ARENA TO PIGEON PT 10-60 NM UNTIL 3 PM
&&
$$
PUBLIC FORECAST: MM
AVIATION: BELL
MARINE: BELL
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AREA FORECAST DISCUSSION
NWS TAUNTON MA
518 PM EDT FRI APR 22 2016
.SYNOPSIS...
A COLD FRONT OVER NEW YORK CROSSES SOUTHERN NEW ENGLAND TONIGHT
AND MOVES OFFSHORE SATURDAY. HIGH PRESSURE THEN BUILDS FOR LATER
SATURDAY AND SUNDAY BRINGING DRY AND SEASONABLE WEATHER. A FRONT WILL
PUSH SLOWLY ACROSS THE REGION MONDAY AND TUESDAY WHICH WILL BRING
MUCH NEEDED SHOWERS TO THE REGION. DRY AND SEASONABLE CONDITIONS
SHOULD MOVE IN AROUND THE MIDDLE OF NEXT WEEK. THEN A LOW PRESSURE
SYSTEM MAY BRING ADDITIONAL RAINFALL TO OUR AREA THIS UPCOMING
THURSDAY AND FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THIS EVENING/EARLY NIGHT...
NORTHERN STREAM SHORTWAVE AND SUPPORTING JET MOVE ACROSS NEW
ENGLAND THIS EVENING. FAVORABLE JET DYNAMICS ALONG WITH LI AROUND
-2 AND SBCAPE AROUND 1000 HAVE BEEN HELPING TO GENERATE SHOWERS
AND A FEW TSTMS OVER THE BERKSHIRES AND HUDSON VALLEY WHICH THEN
MOVE ACROSS WESTERN AND NORTHERN MASS. THESE FAVORABLE CONDITIONS
WILL FADE AFTER SUNSET...BUT UNTIL THEN EXPECT SHOWERS AND A FEW
TSTMS OVER WESTERN/NORTHERN MASS AND NORTHERN CT.
TONIGHT...
THE NEW YORK COLD FRONT EXTRAPOLATES TO THE BERKSHIRES 6-8
PM...THE WORCESTER HILLS 9-11 PM...AND THE EASTERN COAST 12-2 AM.
MEANWHILE...AN OPEN SHORTWAVE OVER OHIO IS MOVING EAST AND WILL
REACH THE MID ATLANTIC COAST BY SATURDAY MORNING. THE SHORTWAVE IS
SUPPORTED BY AN 85-KNOT JET THAT WILL OVERLAY NEW JERSEY AND LONG
ISLAND OVERNIGHT. THIS SHORTWAVE MAY TURN THE UPPER FLOW MORE
PARALLEL TO THE SURFACE COLD FRONT...SLOWING THE FORWARD PROGRESS
OF THAT FRONT. THE SHORTWAVE AND JET MAY ALSO GENERATE A WAVE
ALONG THE FRONT OVERNIGHT. BOTH THE GFS AND HRRR ARE HINTING AT
THIS. THE ECMWF SURFACE MSLP FIELD SHOWS A BAGGINESS SOUTH OF NEW
ENGLAND AT 12Z SAT THAT ALSO HINTS AT THIS.
DEW POINTS HAVE CLIMBED INTO THE 50S. WATER TEMPERATURES ARE IN
THE MID TO UPPER 40S. THIS COOLING OF THE MOIST AIR MAY CREATE
AREAS OF FOG THAT WOULD AFFECT THE SOUTH COAST.
WHILE THE EVENING PCPN TAPERS OFF...THE CHANCE OF SHOWERS ALONG
THE FRONT WILL LINGER UNTIL FROPA. THE UPPER SHORTWAVE AND JET
WILL MAINTAIN A CHANCE OF SHOWERS THROUGH THE NIGHT WITH THE BEST
CHANCE ALONG THE SOUTH COAST. WE WILL MAINTAIN CHANCE POPS THROUGH
THE NIGHT MOST PLACES AND CARRY LIKELY POPS ALONG/SOUTH OF A
HARTFORD-PROVIDENCE LINE. WITH DEW POINTS IN THE UPPER 40S AND
50S...EXPECT MIN TEMPS IN THIS SAME RANGE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
UPPER TROUGH MOVES EAST OF NEW ENGLAND SATURDAY AND PUSHES THE
SURFACE FRONT WELL SOUTH OF OUR AREA. LEFTOVER SHOWERS...MAINLY
OVER RI/SOUTHEAST MASS...SHOULD MOVE OFF WITH THE TROUGH. HIGH
PRESSURE OVER CANADA WILL BUILD INTO NEW ENGLAND BRINGING DRIER
AIR AND CLEARING SKIES. MIXING IS FORECAST TO 900 MB...POSSIBLY A
LITTLE HIGHER. TEMPS AT THAT HEIGHT WOULD SUPPORT MAX SFC TEMPS IN
THE 60S. WINDS IN THE MIXED LAYER WILL BE 15-20 KNOTS...WHICH MAY
BE MIXED TO THE SURFACE IN GUSTS.
AS THE HIGH BUILDS IN...THE PRESSURE GRADIENT WILL LESSEN. NOT
CLEAR WHETHER IT WILL DIMINISH ENOUGH TO ALLOW THE SURFACE AIR TO
DECOUPLE AND ALLOW RADIATIONAL COOLING. DEW POINTS WILL FALL INTO
THE 20S...WHICH WOULD BE QUITE A CHILLY START TO THE DAY IF MINS
REACHED THAT LOW. WE WILL ALLOW A LIGHT NORTH WIND OVERNIGHT AND
KEEP TEMPS ABOVE FREEZING MOST PLACES. THE BEST CHANCE OF
DECOUPLING AND RADIATIONAL COOLING WILL BE IN THE VALLEYS OF
NORTHERN AND WESTERN MASS...WHERE THERE WILL BE THE BEST CHANCE OF
DIPPING BELOW 30. WE WILL NEED TO MONITOR THIS...SUCH COOLING MAY
BE ABLE TO EXTEND FARTHER SOUTH AND EAST.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
OVERVIEW...
LONG WAVE TROUGH ALONG THE EASTERN SEABOARD EARLY THIS WEEKEND
WILL SHIFT E AS OVERALL NORTH AMERICAN UPPER LEVEL STEERING
CURRENTS REMAIN PROGRESSIVE. BROAD H5 VORTEX ELONGATES FROM THE
ARCTIC CIRCLE INTO LABRADOR AND NEWFOUNDLAND BY SUNDAY...WITH THE
BASE OF THE VORTEX KEEPING A FAST W-NW UPPER FLOW ACROSS THE
REGION FOR MOST IF NOT ALL OF THE UPCOMING WEEK. THE NEXT
APPROACHING FRONT WILL MOVE INTO THE REGION BY THE BEGINNING OF
THE WORK WEEK AND...AS IT BECOMES PARALLEL TO THE UPPER FLOW...WILL
SEE MUCH NEEDED RAIN SHOWERS MOVE ACROSS AS THE FRONT SLOWLY PUSHES
OFFSHORE.
CANADIAN HIGH PRESSURE BRINGS DRY CONDITIONS WEDNESDAY. THEN LOW
CONFIDENCE ON THE TIMING AND TRACK AS A QUICK MOVING LOW PRESSURE
SYSTEM THAT SHOULD APPROACH THE REGION OUT OF THE OHIO VALLEY AND
SOUTHERN GREAT LAKES TOWARDS THE END OF THE UPCOMING WORKWEEK.
DETAILS...
SUNDAY...MODERATE TO HIGH CONFIDENCE.
HIGH PERSSURE PASSES OVERHEAD DURING THE DAY. ANTICIAPTE MOSTLY
SUNNY SKIES...THOUGH THE FRONT TO THE NORTHWEST OF OUR AREA MAY
ALLOW FOR SOME AFTERNOON CIRRUS AND MID DECK CLOUDS. SEA BREEZES ARE
LIKELY ALONG THE COAST BY THE AFTERNOON. TEMPS NEAR NORMAL TO A FEW
DEGREES BELOW NORMAL.
SUNDAY NIGHT THROUGH TUESDAY...MODERATE CONFIDENCE.
CLOUDS WILL CONTINUE TO INCREASE SUNDAY NIGHT AS A COLD FRONT MOVES
OUT OF N NY STATE AND NORTHERN NEW ENGLAND. THE FRONT WILL MOVE
SLOWLY TO THE SOUTHEAST...BUT LOOKS LIKE IT WILL REMAIN DRY THROUGH
AT LEAST MIDNIGHT. THE POTENTIAL EXISTS FOR A FEW SHOWERS LATE
SUNDAY NIGHT...MAINLY ACROSS N MA.
THE FRONT LOOKS TO SLOW ITS FORWARD PROGRESS AS IT BECOMES PARALLEL
TO THE UPPER LEVEL WIND FLOW DURING MONDAY. CONTINUE TO EXPECT A
COUPLE OF WAVES OF LOW PRES MOVE ALONG THE FRONT...WHICH WILL ALSO
TEND TO SLOW THE FRONT DOWN. STARTING TO SEE A BIT MORE MOISTURE
CONVERGENCE SETTING UP AS THE FRONT CROSSES...ESPECIALLY MONDAY
NIGHT AND TUESDAY...BRINGING SOME MUCH NEEDED RAINFALL.
FORECAST QPF AMOUNTS LOOK TO BE ON THE ORDER OF 0.5 TO 1 INCH FROM
MONDAY AFTERNOON INTO TUESDAY.
AS THE FRONT CROSSES THE REGION LATE MON NIGHT AND TUESDAY...
COOLER AIR WORKS IN AS WINDS SHIFT TO N AND NE. HIGHS WILL BE CLOSE
TO SEASONAL NORMALS ON MONDAY...BUT WILL FALL DOWN TO SEVERAL
DEGREES BELOW SEASONAL LEVELS ON TUESDAY.
TUESDAY NIGHT AND WEDNESDAY...MODERATE CONFIDENCE.
THE FRONT SHOULD PUSH SOUTH OF OUR AREA DURING TUESDAY NIGHT...WITH
CANADIAN HIGH PRESSURE BUILDING SOUTHEASTWARD. HAVE VERY LOW CHANCE
POPS TO START TUESDAY NIGHT. OTHERWISE EXPECT CLEARING SKIES
TUESDAY NIGHT.
FAST FLOW ALOFT WILL PUSH HIGH PRES ACROSS THE REGION ON
WEDNESDAY WITH DRY BUT COOL CONDITIONS. MOSTLY SUNNY SKIES FORECAST.
WEDNESDAY NIGHT THRU FRIDAY...LOW CONFIDENCE.
A LOT OF QUESTIONS REMAIN ON THE TIMING OF A FAST MOVING LOW
PRESSURE SYSTEM THAT IS EXPECTED TO AFFECT OUR AREA DURING
THISTIMEFRAME. AT THIS POINT HAVE DRY CONDITIONS FOR MOST OF WED
NIGHT...FOLLOWED BY CHANCE TO SLIGHT CHANCE POPS FOR SHOWERS THU
INTO FRI.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...
510 PM UDPATE...CORRECTION TO MENTION 23Z.
THRU 23Z...MODERATE CONFIDENCE. SHOWERS AND ISOLATED T-STORMS
MOVING MAINLY W-E ACROSS SOUTHERN NEW ENGLAND...WITH THE BEST
CHANCE FOR T-STORMS WESTERN-CENTRAL MA AND NORTHERN CT. SOME OF
THE SHOWERS AND ESPECIALLY T-STORMS HAVE BEEN PRODUCING OUTFLOW
BOUNDARIES RESULTING IN ABRUPT AND SUBSTANTIAL WIND SHIFTS IN
VARIABLE DIRECTIONS. THIS WILL BE A RISK THRU 23Z. MAINLY VFR
CONDITIONS ACROSS THE AREA THRU 23Z...WITH LOCALIZED MVFR
CIGS/VSBYS WHERE MODERATE TO HEAVY RAINFALL OCCURS.
AFTER 23Z...HIGH CONFIDENCE. GENERALLY VFR THROUGH MIDNIGHT.
SHOWERS AND A FEW THUNDERSTORMS THIS EVENING IN WESTERN AND
CENTRAL MASS AND NORTHERN CT. SOME SHOWERS MAY BRIEFLY LOWER CIGS
AND VSBYS TO MVFR.
OVERNIGHT...MODERATE CONFIDENCE. AFTER THE FIRST SET OF SHOWERS
DIMINISHES...A SECOND AREA OF SHOWERS WILL MOVE UP FROM THE
SOUTHWEST AFTER MIDNIGHT. EXPECT VFR CIGS TO LOWER TO MVFR
OVERNIGHT IN A FEW SHOWERS...WHILE SOUTH COASTAL NEW ENGLAND WILL
LOWER TO IFR OR LIFR IN SHOWERS AND DEVELOPING FOG.
SATURDAY AND SATURDAY NIGHT... HIGH CONFIDENCE. VFR CONDITIONS IN
THE WEST. CIGS/VSBYS IMPROVE TO VFR IN THE EAST. NORTH WIND AROUND
10 KNOTS WITH POTENTIAL GUSTS NEAR 20 KNOTS IN THE AFTERNOON.
WINDS DIMINISH TOWARD EVENING.
KBOS TERMINAL...MODERATE TO HIGH CONFIDENCE. EAST SEA BREEZE
SHOULD SWITCH TO SOUTH-SOUTHWEST BY LATE AFTERNOON. VFR CONDITIONS
SHOULD PERSIST THROUGH EARLY EVENING...BUT LEFTOVER SHOWERS FROM
WESTERN MASS MAY BRING BRIEF MVFR CIGS/VSBYS THIS EVENING. ANOTHER
AREA OF SHOWERS MOVES THROUGH LATER TONIGHT WITH MVFR CONDITIONS.
KBDL TERMINAL...MODERATE TO HIGH CONFIDENCE. MAINLY VFR. HOWEVER...BRIEF
LOWER CONDITIONS POSSIBLE THIS EVENING IN SCATTERED SHOWERS AND
PERHAPS A THUNDERSTORM. ALSO A PERIOD OF MVFR CIGS POSSIBLE
OVERNIGHT.
OUTLOOK /SUNDAY THROUGH WEDNESDAY/...
SUNDAY AND SUNDAY NIGHT...HIGH CONFIDENCE. VFR SUNDAY INTO SUNDAY
EVENING. MAY SEE MVFR CIGS/VSBYS MOVE INTO NORTHERN AREAS MAINLY
NEAR AND N OF THE MASS PIKE AFTER MIDNIGHT SUNDAY NIGHT.
MONDAY AND TUESDAY...MODERATE CONFIDENCE. AREAS OF MVFR
CIGS/VSBYS IN SHOWERS AND PATCHY FOG. CONDITIONS SHOULD IMPROVE
FROM N-S TUE NIGHT...THOUGH TIMING IS IN QUESTION.
WEDNESDAY...MODERATE CONFIDENCE. VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...
TONIGHT...MODERATE TO HIGH CONFIDENCE.
PERSISTENT SOUTHWEST FLOW AHEAD OF A COLD FRONT WILL REMAIN BELOW
20 KNOTS. THE PERSISTENT FLOW WILL BUILD SEAS A LITTLE WITH 5 FOOT
HEIGHTS ON THE OUTER WATERS SOUTH OF THE ISLANDS. SMALL CRAFT
ADVISORY CONTINUES ON THOSE WATERS. AREAS OF FOG DEVELOP DURING
THE NIGHT WHICH MAY BECOME LOCALLY DENSE...RESULTING IN POOR
VISIBILITY. WINDS WILL SHIFT LATER AT NIGHT AND COME FROM THE
NORTH OR NORTHWEST.
SATURDAY AND SATURDAY NIGHT...NORTH WINDS WITH GUSTS TO 20 KNOTS
SATURDAY AND 20 TO 25 KNOTS SATURDAY NIGHT. SEAS WILL BE 3-4 FEET
SATURDAY. HEIGHTS OF 4-6 FEET POSSIBLE ON THE EASTERN OUTER WATERS
SATURDAY NIGHT. A SMALL CRAFT ADVISORY MAY BE NEEDED ON SOME OF
THE WATERS.
OUTLOOK /SUNDAY THROUGH WEDNESDAY/...
SUNDAY...MODERATE CONFIDENCE. N WINDS VEERING TO THE SE ON SUNDAY.
GUSTS UP TO 25 KT POSSIBLE DURING THE MORNING...MAINLY ALONG THE
OUTER COASTAL WATERS. LINGERING 5 FOOT SEAS ON THE OUTER COASTAL
WATERS SHOULD GRADUALLY SUBSIDE DURING THE DAY.
MONDAY...MODERATE CONFIDENCE.
WINDS AND SEAS BELOW SCA THRESHOLDS. MAY SEE VSBY RESTRICTIONS IN
SCATTERED SHOWERS AND PATCHY FOG MONDAY.
MONDAY NIGHT AND TUESDAY...LOW TO MODERATE CONFIDENCE.
COLD FRONT SLOWLY MOVES FROM N TO S ACROSS THE WATERS. S WINDS
BECOME N DURING MON NIGHT/TUE. THEN THE N WINDS MAY GUST UP TO 20 KT
DURING TUE. SEAS BUILD UP TO 5-6 FT ACROSS THE SOUTHERN WATERS
MONDAY NIGHT AND TUESDAY...AND MAY REACH TO E OF CAPE COD DURING
TUESDAY. SHOULD HAVE SUBSIDING SEAS TUESDAY NIGHT. VSBY RESTRICTIONS
IN SHOWERS AND PATCHY FOG.
WEDNESDAY...MODERATE CONFIDENCE.
WINDS/SEAS BELOW SCA THRESHOLDS.
&&
.FIRE WEATHER...
SATURDAY...WIDELY SCATTERED SHOWERS MAY LINGER ACROSS SE MA/E RI
SATURDAY MORNING WITH N-NW WIND GUSTS UP TO 20 MPH. THESE SHOULD
PUSH OFFSHORE BY MIDDAY. DRY CONDITIONS WILL TAKE OVER SATURDAY
AFTERNOON WITH NORTH TO NORTHWEST WINDS USHERING LOWERING
DEWPOINTS. MINIMUM RELATIVE HUMIDITIES WILL BE FROM 25 TO 40
PERCENT NORTH AND WEST OF I-95 AND 40 TO 60 PERCENT TO THE SOUTH
AND EAST.
SUNDAY...HIGH PRESSURE WILL MOVE ACROSS THE REGION. LIGHT N WINDS AT
5 TO 10 MPH WILL BECOME SW DURING THE AFTERNOON...WITH SEA BREEZES
PROBABLE. MINIMUM RH VALUES WILL BE FROM 20 TO 30 PERCENT FOR MUCH
OF THE AREA...EXCEPT 35 TO 45 PERCENT ALONG THE IMMEDIATE COAST.
MONDAY AND TUESDAY...A SLOW MOVING FRONT COULD BRING A SOAKING
RAINFALL TO SOUTHERN NEW ENGLAND. THE BEST CHANCE FOR APPRECIABLE
RAIN IS MONDAY AFTERNOON THRU TUESDAY MORNING. AT THIS TIME THE
POTENTIAL EXISTS FOR 0.5 TO AROUND 1.0 INCH OF RAINFALL.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SATURDAY FOR ANZ255-256.
&&
$$
SYNOPSIS...WTB/NMB
NEAR TERM...WTB/NMB
SHORT TERM...WTB
LONG TERM...NMB
AVIATION...WTB/NMB
MARINE...WTB/NMB
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
515 PM EDT FRI APR 22 2016
.SYNOPSIS...
A COLD FRONT OVER NEW YORK CROSSES SOUTHERN NEW ENGLAND TONIGHT
AND MOVES OFFSHORE SATURDAY. HIGH PRESSURE THEN BUILDS FOR LATER
SATURDAY AND SUNDAY BRINGING DRY AND SEASONABLE WEATHER. A FRONT WILL
PUSH SLOWLY ACROSS THE REGION MONDAY AND TUESDAY WHICH WILL BRING
MUCH NEEDED SHOWERS TO THE REGION. DRY AND SEASONABLE CONDITIONS
SHOULD MOVE IN AROUND THE MIDDLE OF NEXT WEEK. THEN A LOW PRESSURE
SYSTEM MAY BRING ADDITIONAL RAINFALL TO OUR AREA THIS UPCOMING
THURSDAY AND FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THIS EVENING/EARLY NIGHT...
NORTHERN STREAM SHORTWAVE AND SUPPORTING JET MOVE ACROSS NEW
ENGLAND THIS EVENING. FAVORABLE JET DYNAMICS ALONG WITH LI AROUND
-2 AND SBCAPE AROUND 1000 HAVE BEEN HELPING TO GENERATE SHOWERS
AND A FEW TSTMS OVER THE BERKSHIRES AND HUDSON VALLEY WHICH THEN
MOVE ACROSS WESTERN AND NORTHERN MASS. THESE FAVORABLE CONDITIONS
WILL FADE AFTER SUNSET...BUT UNTIL THEN EXPECT SHOWERS AND A FEW
TSTMS OVER WESTERN/NORTHERN MASS AND NORTHERN CT.
TONIGHT...
THE NEW YORK COLD FRONT EXTRAPOLATES TO THE BERKSHIRES 6-8
PM...THE WORCESTER HILLS 9-11 PM...AND THE EASTERN COAST 12-2 AM.
MEANWHILE...AN OPEN SHORTWAVE OVER OHIO IS MOVING EAST AND WILL
REACH THE MID ATLANTIC COAST BY SATURDAY MORNING. THE SHORTWAVE IS
SUPPORTED BY AN 85-KNOT JET THAT WILL OVERLAY NEW JERSEY AND LONG
ISLAND OVERNIGHT. THIS SHORTWAVE MAY TURN THE UPPER FLOW MORE
PARALLEL TO THE SURFACE COLD FRONT...SLOWING THE FORWARD PROGRESS
OF THAT FRONT. THE SHORTWAVE AND JET MAY ALSO GENERATE A WAVE
ALONG THE FRONT OVERNIGHT. BOTH THE GFS AND HRRR ARE HINTING AT
THIS. THE ECMWF SURFACE MSLP FIELD SHOWS A BAGGINESS SOUTH OF NEW
ENGLAND AT 12Z SAT THAT ALSO HINTS AT THIS.
DEW POINTS HAVE CLIMBED INTO THE 50S. WATER TEMPERATURES ARE IN
THE MID TO UPPER 40S. THIS COOLING OF THE MOIST AIR MAY CREATE
AREAS OF FOG THAT WOULD AFFECT THE SOUTH COAST.
WHILE THE EVENING PCPN TAPERS OFF...THE CHANCE OF SHOWERS ALONG
THE FRONT WILL LINGER UNTIL FROPA. THE UPPER SHORTWAVE AND JET
WILL MAINTAIN A CHANCE OF SHOWERS THROUGH THE NIGHT WITH THE BEST
CHANCE ALONG THE SOUTH COAST. WE WILL MAINTAIN CHANCE POPS THROUGH
THE NIGHT MOST PLACES AND CARRY LIKELY POPS ALONG/SOUTH OF A
HARTFORD-PROVIDENCE LINE. WITH DEW POINTS IN THE UPPER 40S AND
50S...EXPECT MIN TEMPS IN THIS SAME RANGE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
UPPER TROUGH MOVES EAST OF NEW ENGLAND SATURDAY AND PUSHES THE
SURFACE FRONT WELL SOUTH OF OUR AREA. LEFTOVER SHOWERS...MAINLY
OVER RI/SOUTHEAST MASS...SHOULD MOVE OFF WITH THE TROUGH. HIGH
PRESSURE OVER CANADA WILL BUILD INTO NEW ENGLAND BRINGING DRIER
AIR AND CLEARING SKIES. MIXING IS FORECAST TO 900 MB...POSSIBLY A
LITTLE HIGHER. TEMPS AT THAT HEIGHT WOULD SUPPORT MAX SFC TEMPS IN
THE 60S. WINDS IN THE MIXED LAYER WILL BE 15-20 KNOTS...WHICH MAY
BE MIXED TO THE SURFACE IN GUSTS.
AS THE HIGH BUILDS IN...THE PRESSURE GRADIENT WILL LESSEN. NOT
CLEAR WHETHER IT WILL DIMINISH ENOUGH TO ALLOW THE SURFACE AIR TO
DECOUPLE AND ALLOW RADIATIONAL COOLING. DEW POINTS WILL FALL INTO
THE 20S...WHICH WOULD BE QUITE A CHILLY START TO THE DAY IF MINS
REACHED THAT LOW. WE WILL ALLOW A LIGHT NORTH WIND OVERNIGHT AND
KEEP TEMPS ABOVE FREEZING MOST PLACES. THE BEST CHANCE OF
DECOUPLING AND RADIATIONAL COOLING WILL BE IN THE VALLEYS OF
NORTHERN AND WESTERN MASS...WHERE THERE WILL BE THE BEST CHANCE OF
DIPPING BELOW 30. WE WILL NEED TO MONITOR THIS...SUCH COOLING MAY
BE ABLE TO EXTEND FARTHER SOUTH AND EAST.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
OVERVIEW...
LONG WAVE TROUGH ALONG THE EASTERN SEABOARD EARLY THIS WEEKEND
WILL SHIFT E AS OVERALL NORTH AMERICAN UPPER LEVEL STEERING
CURRENTS REMAIN PROGRESSIVE. BROAD H5 VORTEX ELONGATES FROM THE
ARCTIC CIRCLE INTO LABRADOR AND NEWFOUNDLAND BY SUNDAY...WITH THE
BASE OF THE VORTEX KEEPING A FAST W-NW UPPER FLOW ACROSS THE
REGION FOR MOST IF NOT ALL OF THE UPCOMING WEEK. THE NEXT
APPROACHING FRONT WILL MOVE INTO THE REGION BY THE BEGINNING OF
THE WORK WEEK AND...AS IT BECOMES PARALLEL TO THE UPPER FLOW...WILL
SEE MUCH NEEDED RAIN SHOWERS MOVE ACROSS AS THE FRONT SLOWLY PUSHES
OFFSHORE.
CANADIAN HIGH PRESSURE BRINGS DRY CONDITIONS WEDNESDAY. THEN LOW
CONFIDENCE ON THE TIMING AND TRACK AS A QUICK MOVING LOW PRESSURE
SYSTEM THAT SHOULD APPROACH THE REGION OUT OF THE OHIO VALLEY AND
SOUTHERN GREAT LAKES TOWARDS THE END OF THE UPCOMING WORKWEEK.
DETAILS...
SUNDAY...MODERATE TO HIGH CONFIDENCE.
HIGH PERSSURE PASSES OVERHEAD DURING THE DAY. ANTICIAPTE MOSTLY
SUNNY SKIES...THOUGH THE FRONT TO THE NORTHWEST OF OUR AREA MAY
ALLOW FOR SOME AFTERNOON CIRRUS AND MID DECK CLOUDS. SEA BREEZES ARE
LIKELY ALONG THE COAST BY THE AFTERNOON. TEMPS NEAR NORMAL TO A FEW
DEGREES BELOW NORMAL.
SUNDAY NIGHT THROUGH TUESDAY...MODERATE CONFIDENCE.
CLOUDS WILL CONTINUE TO INCREASE SUNDAY NIGHT AS A COLD FRONT MOVES
OUT OF N NY STATE AND NORTHERN NEW ENGLAND. THE FRONT WILL MOVE
SLOWLY TO THE SOUTHEAST...BUT LOOKS LIKE IT WILL REMAIN DRY THROUGH
AT LEAST MIDNIGHT. THE POTENTIAL EXISTS FOR A FEW SHOWERS LATE
SUNDAY NIGHT...MAINLY ACROSS N MA.
THE FRONT LOOKS TO SLOW ITS FORWARD PROGRESS AS IT BECOMES PARALLEL
TO THE UPPER LEVEL WIND FLOW DURING MONDAY. CONTINUE TO EXPECT A
COUPLE OF WAVES OF LOW PRES MOVE ALONG THE FRONT...WHICH WILL ALSO
TEND TO SLOW THE FRONT DOWN. STARTING TO SEE A BIT MORE MOISTURE
CONVERGENCE SETTING UP AS THE FRONT CROSSES...ESPECIALLY MONDAY
NIGHT AND TUESDAY...BRINGING SOME MUCH NEEDED RAINFALL.
FORECAST QPF AMOUNTS LOOK TO BE ON THE ORDER OF 0.5 TO 1 INCH FROM
MONDAY AFTERNOON INTO TUESDAY.
AS THE FRONT CROSSES THE REGION LATE MON NIGHT AND TUESDAY...
COOLER AIR WORKS IN AS WINDS SHIFT TO N AND NE. HIGHS WILL BE CLOSE
TO SEASONAL NORMALS ON MONDAY...BUT WILL FALL DOWN TO SEVERAL
DEGREES BELOW SEASONAL LEVELS ON TUESDAY.
TUESDAY NIGHT AND WEDNESDAY...MODERATE CONFIDENCE.
THE FRONT SHOULD PUSH SOUTH OF OUR AREA DURING TUESDAY NIGHT...WITH
CANADIAN HIGH PRESSURE BUILDING SOUTHEASTWARD. HAVE VERY LOW CHANCE
POPS TO START TUESDAY NIGHT. OTHERWISE EXPECT CLEARING SKIES
TUESDAY NIGHT.
FAST FLOW ALOFT WILL PUSH HIGH PRES ACROSS THE REGION ON
WEDNESDAY WITH DRY BUT COOL CONDITIONS. MOSTLY SUNNY SKIES FORECAST.
WEDNESDAY NIGHT THRU FRIDAY...LOW CONFIDENCE.
A LOT OF QUESTIONS REMAIN ON THE TIMING OF A FAST MOVING LOW
PRESSURE SYSTEM THAT IS EXPECTED TO AFFECT OUR AREA DURING
THISTIMEFRAME. AT THIS POINT HAVE DRY CONDITIONS FOR MOST OF WED
NIGHT...FOLLOWED BY CHANCE TO SLIGHT CHANCE POPS FOR SHOWERS THU
INTO FRI.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...
510 PM UDPATE...
THRU 23Z...MODERATE CONFIDENCE. SHOWERS AND ISOLATED T-STORMS
MOVING MAINLY W-E ACROSS SOUTHERN NEW ENGLAND...WITH THE BEST
CHANCE FOR T-STORMS WESTERN-CENTRAL MA AND NORTHERN CT. SOME OF
THE SHOWERS AND ESPECIALLY T-STORMS HAVE BEEN PRODUCING OUTFLOW
BOUNDARIES RESULTING IN ABRUPT AND SUBSTANTIAL WIND SHIFTS IN
VARIABLE DIRECTIONS. THIS WILL BE A RISK THRU 00Z. MAINLY VFR
CONDITIONS ACROSS THE AREA THRU 00Z...WITH LOCALIZED MVFR
CIGS/VSBYS WHERE MODERATE TO HEAVY RAINFALL OCCURS.
AFTER 23Z THIS EVENING...HIGH CONFIDENCE. GENERALLY VFR THROUGH
MIDNIGHT. SHOWERS AND A FEW THUNDERSTORMS THIS EVENING IN WESTERN
AND CENTRAL MASS AND NORTHERN CT. SOME SHOWERS MAY BRIEFLY LOWER
CIGS AND VSBYS TO MVFR.
TONIGHT...MODERATE CONFIDENCE. AFTER THE FIRST SET OF SHOWERS
DIMINISHES...A SECOND AREA OF SHOWERS WILL MOVE UP FROM THE
SOUTHWEST AFTER MIDNIGHT. EXPECT VFR CIGS TO LOWER TO MVFR
OVERNIGHT IN A FEW SHOWERS...WHILE SOUTH COASTAL NEW ENGLAND WILL
LOWER TO IFR OR LIFR IN SHOWERS AND DEVELOPING FOG.
SATURDAY AND SATURDAY NIGHT... HIGH CONFIDENCE. VFR CONDITIONS IN
THE WEST. CIGS/VSBYS IMPROVE TO VFR IN THE EAST. NORTH WIND AROUND
10 KNOTS WITH POTENTIAL GUSTS NEAR 20 KNOTS IN THE AFTERNOON.
WINDS DIMINISH TOWARD EVENING.
KBOS TERMINAL...MODERATE TO HIGH CONFIDENCE. EAST SEA BREEZE
SHOULD SWITCH TO SOUTH-SOUTHWEST BY LATE AFTERNOON. VFR CONDITIONS
SHOULD PERSIST THROUGH EARLY EVENING...BUT LEFTOVER SHOWERS FROM
WESTERN MASS MAY BRING BRIEF MVFR CIGS/VSBYS THIS EVENING. ANOTHER
AREA OF SHOWERS MOVES THROUGH LATER TONIGHT WITH MVFR CONDITIONS.
KBDL TERMINAL...MODERATE TO HIGH CONFIDENCE. MAINLY VFR. HOWEVER...BRIEF
LOWER CONDITIONS POSSIBLE THIS EVENING IN SCATTERED SHOWERS AND
PERHAPS A THUNDERSTORM. ALSO A PERIOD OF MVFR CIGS POSSIBLE
OVERNIGHT.
OUTLOOK /SUNDAY THROUGH WEDNESDAY/...
SUNDAY AND SUNDAY NIGHT...HIGH CONFIDENCE. VFR SUNDAY INTO SUNDAY
EVENING. MAY SEE MVFR CIGS/VSBYS MOVE INTO NORTHERN AREAS MAINLY
NEAR AND N OF THE MASS PIKE AFTER MIDNIGHT SUNDAY NIGHT.
MONDAY AND TUESDAY...MODERATE CONFIDENCE. AREAS OF MVFR
CIGS/VSBYS IN SHOWERS AND PATCHY FOG. CONDITIONS SHOULD IMPROVE
FROM N-S TUE NIGHT...THOUGH TIMING IS IN QUESTION.
WEDNESDAY...MODERATE CONFIDENCE. VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...
TONIGHT...MODERATE TO HIGH CONFIDENCE.
PERSISTENT SOUTHWEST FLOW AHEAD OF A COLD FRONT WILL REMAIN BELOW
20 KNOTS. THE PERSISTENT FLOW WILL BUILD SEAS A LITTLE WITH 5 FOOT
HEIGHTS ON THE OUTER WATERS SOUTH OF THE ISLANDS. SMALL CRAFT
ADVISORY CONTINUES ON THOSE WATERS. AREAS OF FOG DEVELOP DURING
THE NIGHT WHICH MAY BECOME LOCALLY DENSE...RESULTING IN POOR
VISIBILITY. WINDS WILL SHIFT LATER AT NIGHT AND COME FROM THE
NORTH OR NORTHWEST.
SATURDAY AND SATURDAY NIGHT...NORTH WINDS WITH GUSTS TO 20 KNOTS
SATURDAY AND 20 TO 25 KNOTS SATURDAY NIGHT. SEAS WILL BE 3-4 FEET
SATURDAY. HEIGHTS OF 4-6 FEET POSSIBLE ON THE EASTERN OUTER WATERS
SATURDAY NIGHT. A SMALL CRAFT ADVISORY MAY BE NEEDED ON SOME OF
THE WATERS.
OUTLOOK /SUNDAY THROUGH WEDNESDAY/...
SUNDAY...MODERATE CONFIDENCE. N WINDS VEERING TO THE SE ON SUNDAY.
GUSTS UP TO 25 KT POSSIBLE DURING THE MORNING...MAINLY ALONG THE
OUTER COASTAL WATERS. LINGERING 5 FOOT SEAS ON THE OUTER COASTAL
WATERS SHOULD GRADUALLY SUBSIDE DURING THE DAY.
MONDAY...MODERATE CONFIDENCE.
WINDS AND SEAS BELOW SCA THRESHOLDS. MAY SEE VSBY RESTRICTIONS IN
SCATTERED SHOWERS AND PATCHY FOG MONDAY.
MONDAY NIGHT AND TUESDAY...LOW TO MODERATE CONFIDENCE.
COLD FRONT SLOWLY MOVES FROM N TO S ACROSS THE WATERS. S WINDS
BECOME N DURING MON NIGHT/TUE. THEN THE N WINDS MAY GUST UP TO 20 KT
DURING TUE. SEAS BUILD UP TO 5-6 FT ACROSS THE SOUTHERN WATERS
MONDAY NIGHT AND TUESDAY...AND MAY REACH TO E OF CAPE COD DURING
TUESDAY. SHOULD HAVE SUBSIDING SEAS TUESDAY NIGHT. VSBY RESTRICTIONS
IN SHOWERS AND PATCHY FOG.
WEDNESDAY...MODERATE CONFIDENCE.
WINDS/SEAS BELOW SCA THRESHOLDS.
&&
.FIRE WEATHER...
SATURDAY...WIDELY SCATTERED SHOWERS MAY LINGER ACROSS SE MA/E RI
SATURDAY MORNING WITH N-NW WIND GUSTS UP TO 20 MPH. THESE SHOULD
PUSH OFFSHORE BY MIDDAY. DRY CONDITIONS WILL TAKE OVER SATURDAY
AFTERNOON WITH NORTH TO NORTHWEST WINDS USHERING LOWERING
DEWPOINTS. MINIMUM RELATIVE HUMIDITIES WILL BE FROM 25 TO 40
PERCENT NORTH AND WEST OF I-95 AND 40 TO 60 PERCENT TO THE SOUTH
AND EAST.
SUNDAY...HIGH PRESSURE WILL MOVE ACROSS THE REGION. LIGHT N WINDS AT
5 TO 10 MPH WILL BECOME SW DURING THE AFTERNOON...WITH SEA BREEZES
PROBABLE. MINIMUM RH VALUES WILL BE FROM 20 TO 30 PERCENT FOR MUCH
OF THE AREA...EXCEPT 35 TO 45 PERCENT ALONG THE IMMEDIATE COAST.
MONDAY AND TUESDAY...A SLOW MOVING FRONT COULD BRING A SOAKING
RAINFALL TO SOUTHERN NEW ENGLAND. THE BEST CHANCE FOR APPRECIABLE
RAIN IS MONDAY AFTERNOON THRU TUESDAY MORNING. AT THIS TIME THE
POTENTIAL EXISTS FOR 0.5 TO AROUND 1.0 INCH OF RAINFALL.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SATURDAY FOR ANZ255-256.
&&
$$
SYNOPSIS...WTB/NMB
NEAR TERM...WTB/NMB
SHORT TERM...WTB
LONG TERM...NMB
AVIATION...WTB/NMB
MARINE...WTB/NMB
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
418 PM EDT FRI APR 22 2016
.SYNOPSIS...
A COLD FRONT OVER NEW YORK CROSSES SOUTHERN NEW ENGLAND TONIGHT
AND MOVES OFFSHORE SATURDAY. HIGH PRESSURE THEN BUILDS FOR LATER
SATURDAY AND SUNDAY BRINGING DRY AND SEASONABLE WEATHER. A FRONT WILL
PUSH SLOWLY ACROSS THE REGION MONDAY AND TUESDAY WHICH WILL BRING
MUCH NEEDED SHOWERS TO THE REGION. DRY AND SEASONABLE CONDITIONS
SHOULD MOVE IN AROUND THE MIDDLE OF NEXT WEEK. THEN A LOW PRESSURE
SYSTEM MAY BRING ADDITIONAL RAINFALL TO OUR AREA THIS UPCOMING
THURSDAY AND FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THIS EVENING/EARLY NIGHT...
NORTHERN STREAM SHORTWAVE AND SUPPORTING JET MOVE ACROSS NEW
ENGLAND THIS EVENING. FAVORABLE JET DYNAMICS ALONG WITH LI AROUND
-2 AND SBCAPE AROUND 1000 HAVE BEEN HELPING TO GENERATE SHOWERS
AND A FEW TSTMS OVER THE BERKSHIRES AND HUDSON VALLEY WHICH THEN
MOVE ACROSS WESTERN AND NORTHERN MASS. THESE FAVORABLE CONDITIONS
WILL FADE AFTER SUNSET...BUT UNTIL THEN EXPECT SHOWERS AND A FEW
TSTMS OVER WESTERN/NORTHERN MASS AND NORTHERN CT.
TONIGHT...
THE NEW YORK COLD FRONT EXTRAPOLATES TO THE BERKSHIRES 6-8
PM...THE WORCESTER HILLS 9-11 PM...AND THE EASTERN COAST 12-2 AM.
MEANWHILE...AN OPEN SHORTWAVE OVER OHIO IS MOVING EAST AND WILL
REACH THE MID ATLANTIC COAST BY SATURDAY MORNING. THE SHORTWAVE IS
SUPPORTED BY AN 85-KNOT JET THAT WILL OVERLAY NEW JERSEY AND LONG
ISLAND OVERNIGHT. THIS SHORTWAVE MAY TURN THE UPPER FLOW MORE
PARALLEL TO THE SURFACE COLD FRONT...SLOWING THE FORWARD PROGRESS
OF THAT FRONT. THE SHORTWAVE AND JET MAY ALSO GENERATE A WAVE
ALONG THE FRONT OVERNIGHT. BOTH THE GFS AND HRRR ARE HINTING AT
THIS. THE ECMWF SURFACE MSLP FIELD SHOWS A BAGGINESS SOUTH OF NEW
ENGLAND AT 12Z SAT THAT ALSO HINTS AT THIS.
DEW POINTS HAVE CLIMBED INTO THE 50S. WATER TEMPERATURES ARE IN
THE MID TO UPPER 40S. THIS COOLING OF THE MOIST AIR MAY CREATE
AREAS OF FOG THAT WOULD AFFECT THE SOUTH COAST.
WHILE THE EVENING PCPN TAPERS OFF...THE CHANCE OF SHOWERS ALONG
THE FRONT WILL LINGER UNTIL FROPA. THE UPPER SHORTWAVE AND JET
WILL MAINTAIN A CHANCE OF SHOWERS THROUGH THE NIGHT WITH THE BEST
CHANCE ALONG THE SOUTH COAST. WE WILL MAINTAIN CHANCE POPS THROUGH
THE NIGHT MOST PLACES AND CARRY LIKELY POPS ALONG/SOUTH OF A
HARTFORD-PROVIDENCE LINE. WITH DEW POINTS IN THE UPPER 40S AND
50S...EXPECT MIN TEMPS IN THIS SAME RANGE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
UPPER TROUGH MOVES EAST OF NEW ENGLAND SATURDAY AND PUSHES THE
SURFACE FRONT WELL SOUTH OF OUR AREA. LEFTOVER SHOWERS...MAINLY
OVER RI/SOUTHEAST MASS...SHOULD MOVE OFF WITH THE TROUGH. HIGH
PRESSURE OVER CANADA WILL BUILD INTO NEW ENGLAND BRINGING DRIER
AIR AND CLEARING SKIES. MIXING IS FORECAST TO 900 MB...POSSIBLY A
LITTLE HIGHER. TEMPS AT THAT HEIGHT WOULD SUPPORT MAX SFC TEMPS IN
THE 60S. WINDS IN THE MIXED LAYER WILL BE 15-20 KNOTS...WHICH MAY
BE MIXED TO THE SURFACE IN GUSTS.
AS THE HIGH BUILDS IN...THE PRESSURE GRADIENT WILL LESSEN. NOT
CLEAR WHETHER IT WILL DIMINISH ENOUGH TO ALLOW THE SURFACE AIR TO
DECOUPLE AND ALLOW RADIATIONAL COOLING. DEW POINTS WILL FALL INTO
THE 20S...WHICH WOULD BE QUITE A CHILLY START TO THE DAY IF MINS
REACHED THAT LOW. WE WILL ALLOW A LIGHT NORTH WIND OVERNIGHT AND
KEEP TEMPS ABOVE FREEZING MOST PLACES. THE BEST CHANCE OF
DECOUPLING AND RADIATIONAL COOLING WILL BE IN THE VALLEYS OF
NORTHERN AND WESTERN MASS...WHERE THERE WILL BE THE BEST CHANCE OF
DIPPING BELOW 30. WE WILL NEED TO MONITOR THIS...SUCH COOLING MAY
BE ABLE TO EXTEND FARTHER SOUTH AND EAST.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
OVERVIEW...
LONG WAVE TROUGH ALONG THE EASTERN SEABOARD EARLY THIS WEEKEND
WILL SHIFT E AS OVERALL NORTH AMERICAN UPPER LEVEL STEERING
CURRENTS REMAIN PROGRESSIVE. BROAD H5 VORTEX ELONGATES FROM THE
ARCTIC CIRCLE INTO LABRADOR AND NEWFOUNDLAND BY SUNDAY...WITH THE
BASE OF THE VORTEX KEEPING A FAST W-NW UPPER FLOW ACROSS THE
REGION FOR MOST IF NOT ALL OF THE UPCOMING WEEK. THE NEXT
APPROACHING FRONT WILL MOVE INTO THE REGION BY THE BEGINNING OF
THE WORK WEEK AND...AS IT BECOMES PARALLEL TO THE UPPER FLOW...WILL
SEE MUCH NEEDED RAIN SHOWERS MOVE ACROSS AS THE FRONT SLOWLY PUSHES
OFFSHORE.
CANADIAN HIGH PRESSURE BRINGS DRY CONDITIONS WEDNESDAY. THEN LOW
CONFIDENCE ON THE TIMING AND TRACK AS A QUICK MOVING LOW PRESSURE
SYSTEM THAT SHOULD APPROACH THE REGION OUT OF THE OHIO VALLEY AND
SOUTHERN GREAT LAKES TOWARDS THE END OF THE UPCOMING WORKWEEK.
DETAILS...
SUNDAY...MODERATE TO HIGH CONFIDENCE.
HIGH PERSSURE PASSES OVERHEAD DURING THE DAY. ANTICIAPTE MOSTLY
SUNNY SKIES...THOUGH THE FRONT TO THE NORTHWEST OF OUR AREA MAY
ALLOW FOR SOME AFTERNOON CIRRUS AND MID DECK CLOUDS. SEA BREEZES ARE
LIKELY ALONG THE COAST BY THE AFTERNOON. TEMPS NEAR NORMAL TO A FEW
DEGREES BELOW NORMAL.
SUNDAY NIGHT THROUGH TUESDAY...MODERATE CONFIDENCE.
CLOUDS WILL CONTINUE TO INCREASE SUNDAY NIGHT AS A COLD FRONT MOVES
OUT OF N NY STATE AND NORTHERN NEW ENGLAND. THE FRONT WILL MOVE
SLOWLY TO THE SOUTHEAST...BUT LOOKS LIKE IT WILL REMAIN DRY THROUGH
AT LEAST MIDNIGHT. THE POTENTIAL EXISTS FOR A FEW SHOWERS LATE
SUNDAY NIGHT...MAINLY ACROSS N MA.
THE FRONT LOOKS TO SLOW ITS FORWARD PROGRESS AS IT BECOMES PARALLEL
TO THE UPPER LEVEL WIND FLOW DURING MONDAY. CONTINUE TO EXPECT A
COUPLE OF WAVES OF LOW PRES MOVE ALONG THE FRONT...WHICH WILL ALSO
TEND TO SLOW THE FRONT DOWN. STARTING TO SEE A BIT MORE MOISTURE
CONVERGENCE SETTING UP AS THE FRONT CROSSES...ESPECIALLY MONDAY
NIGHT AND TUESDAY...BRINGING SOME MUCH NEEDED RAINFALL.
FORECAST QPF AMOUNTS LOOK TO BE ON THE ORDER OF 0.5 TO 1 INCH FROM
MONDAY AFTERNOON INTO TUESDAY.
AS THE FRONT CROSSES THE REGION LATE MON NIGHT AND TUESDAY...
COOLER AIR WORKS IN AS WINDS SHIFT TO N AND NE. HIGHS WILL BE CLOSE
TO SEASONAL NORMALS ON MONDAY...BUT WILL FALL DOWN TO SEVERAL
DEGREES BELOW SEASONAL LEVELS ON TUESDAY.
TUESDAY NIGHT AND WEDNESDAY...MODERATE CONFIDENCE.
THE FRONT SHOULD PUSH SOUTH OF OUR AREA DURING TUESDAY NIGHT...WITH
CANADIAN HIGH PRESSURE BUILDING SOUTHEASTWARD. HAVE VERY LOW CHANCE
POPS TO START TUESDAY NIGHT. OTHERWISE EXPECT CLEARING SKIES
TUESDAY NIGHT.
FAST FLOW ALOFT WILL PUSH HIGH PRES ACROSS THE REGION ON
WEDNESDAY WITH DRY BUT COOL CONDITIONS. MOSTLY SUNNY SKIES FORECAST.
WEDNESDAY NIGHT THRU FRIDAY...LOW CONFIDENCE.
A LOT OF QUESTIONS REMAIN ON THE TIMING OF A FAST MOVING LOW
PRESSURE SYSTEM THAT IS EXPECTED TO AFFECT OUR AREA DURING
THISTIMEFRAME. AT THIS POINT HAVE DRY CONDITIONS FOR MOST OF WED
NIGHT...FOLLOWED BY CHANCE TO SLIGHT CHANCE POPS FOR SHOWERS THU
INTO FRI.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...
THIS EVENING... HIGH CONFIDENCE. GENERALLY VFR THROUGH MIDNIGHT.
SHOWERS AND A FEW THUNDERSTORMS THIS EVENING IN WESTERN AND
CENTRAL MASS AND NORTHERN CT. SOME SHOWERS MAY BRIEFLY LOWER CIGS
AND VSBYS TO MVFR.
TONIGHT...MODERATE CONFIDENCE. AFTER THE FIRST SET OF SHOWERS
DIMINISHES...A SECOND AREA OF SHOWERS WILL MOVE UP FROM THE
SOUTHWEST AFTER MIDNIGHT. EXPECT VFR CIGS TO LOWER TO MVFR
OVERNIGHT IN A FEW SHOWERS...WHILE SOUTH COASTAL NEW ENGLAND WILL
LOWER TO IFR OR LIFR IN SHOWERS AND DEVELOPING FOG.
SATURDAY AND SATURDAY NIGHT... HIGH CONFIDENCE. VFR CONDITIONS IN
THE WEST. CIGS/VSBYS IMPROVE TO VFR IN THE EAST. NORTH WIND AROUND
10 KNOTS WITH POTENTIAL GUSTS NEAR 20 KNOTS IN THE AFTERNOON.
WINDS DIMINISH TOWARD EVENING.
KBOS TERMINAL...MODERATE TO HIGH CONFIDENCE. EAST SEA BREEZE
SHOULD SWITCH TO SOUTH-SOUTHWEST BY LATE AFTERNOON. VFR CONDITIONS
SHOULD PERSIST THROUGH EARLY EVENING...BUT LEFTOVER SHOWERS FROM
WESTERN MASS MAY BRING BRIEF MVFR CIGS/VSBYS THIS EVENING. ANOTHER
AREA OF SHOWERS MOVES THROUGH LATER TONIGHT WITH MVFR CONDITIONS.
KBDL TERMINAL...MODERATE TO HIGH CONFIDENCE. MAINLY VFR. HOWEVER...BRIEF
LOWER CONDITIONS POSSIBLE THIS EVENING IN SCATTERED SHOWERS AND
PERHAPS A THUNDERSTORM. ALSO A PERIOD OF MVFR CIGS POSSIBLE
OVERNIGHT.
OUTLOOK /SUNDAY THROUGH WEDNESDAY/...
SUNDAY AND SUNDAY NIGHT...HIGH CONFIDENCE. VFR SUNDAY INTO SUNDAY
EVENING. MAY SEE MVFR CIGS/VSBYS MOVE INTO NORTHERN AREAS MAINLY
NEAR AND N OF THE MASS PIKE AFTER MIDNIGHT SUNDAY NIGHT.
MONDAY AND TUESDAY...MODERATE CONFIDENCE. AREAS OF MVFR
CIGS/VSBYS IN SHOWERS AND PATCHY FOG. CONDITIONS SHOULD IMPROVE
FROM N-S TUE NIGHT...THOUGH TIMING IS IN QUESTION.
WEDNESDAY...MODERATE CONFIDENCE. VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...
TONIGHT...MODERATE TO HIGH CONFIDENCE.
PERSISTENT SOUTHWEST FLOW AHEAD OF A COLD FRONT WILL REMAIN BELOW
20 KNOTS. THE PERSISTENT FLOW WILL BUILD SEAS A LITTLE WITH 5 FOOT
HEIGHTS ON THE OUTER WATERS SOUTH OF THE ISLANDS. SMALL CRAFT
ADVISORY CONTINUES ON THOSE WATERS. AREAS OF FOG DEVELOP DURING
THE NIGHT WHICH MAY BECOME LOCALLY DENSE...RESULTING IN POOR
VISIBILITY. WINDS WILL SHIFT LATER AT NIGHT AND COME FROM THE
NORTH OR NORTHWEST.
SATURDAY AND SATURDAY NIGHT...NORTH WINDS WITH GUSTS TO 20 KNOTS
SATURDAY AND 20 TO 25 KNOTS SATURDAY NIGHT. SEAS WILL BE 3-4 FEET
SATURDAY. HEIGHTS OF 4-6 FEET POSSIBLE ON THE EASTERN OUTER WATERS
SATURDAY NIGHT. A SMALL CRAFT ADVISORY MAY BE NEEDED ON SOME OF
THE WATERS.
OUTLOOK /SUNDAY THROUGH WEDNESDAY/...
SUNDAY...MODERATE CONFIDENCE. N WINDS VEERING TO THE SE ON SUNDAY.
GUSTS UP TO 25 KT POSSIBLE DURING THE MORNING...MAINLY ALONG THE
OUTER COASTAL WATERS. LINGERING 5 FOOT SEAS ON THE OUTER COASTAL
WATERS SHOULD GRADUALLY SUBSIDE DURING THE DAY.
MONDAY...MODERATE CONFIDENCE.
WINDS AND SEAS BELOW SCA THRESHOLDS. MAY SEE VSBY RESTRICTIONS IN
SCATTERED SHOWERS AND PATCHY FOG MONDAY.
MONDAY NIGHT AND TUESDAY...LOW TO MODERATE CONFIDENCE.
COLD FRONT SLOWLY MOVES FROM N TO S ACROSS THE WATERS. S WINDS
BECOME N DURING MON NIGHT/TUE. THEN THE N WINDS MAY GUST UP TO 20 KT
DURING TUE. SEAS BUILD UP TO 5-6 FT ACROSS THE SOUTHERN WATERS
MONDAY NIGHT AND TUESDAY...AND MAY REACH TO E OF CAPE COD DURING
TUESDAY. SHOULD HAVE SUBSIDING SEAS TUESDAY NIGHT. VSBY RESTRICTIONS
IN SHOWERS AND PATCHY FOG.
WEDNESDAY...MODERATE CONFIDENCE.
WINDS/SEAS BELOW SCA THRESHOLDS.
&&
.FIRE WEATHER...
SATURDAY...WIDELY SCATTERED SHOWERS MAY LINGER ACROSS SE MA/E RI
SATURDAY MORNING WITH N-NW WIND GUSTS UP TO 20 MPH. THESE SHOULD
PUSH OFFSHORE BY MIDDAY. DRY CONDITIONS WILL TAKE OVER SATURDAY
AFTERNOON WITH NORTH TO NORTHWEST WINDS USHERING LOWERING
DEWPOINTS. MINIMUM RELATIVE HUMIDITIES WILL BE FROM 25 TO 40
PERCENT NORTH AND WEST OF I-95 AND 40 TO 60 PERCENT TO THE SOUTH
AND EAST.
SUNDAY...HIGH PRESSURE WILL MOVE ACROSS THE REGION. LIGHT N WINDS AT
5 TO 10 MPH WILL BECOME SW DURING THE AFTERNOON...WITH SEA BREEZES
PROBABLE. MINIMUM RH VALUES WILL BE FROM 20 TO 30 PERCENT FOR MUCH
OF THE AREA...EXCEPT 35 TO 45 PERCENT ALONG THE IMMEDIATE COAST.
MONDAY AND TUESDAY...A SLOW MOVING FRONT COULD BRING A SOAKING
RAINFALL TO SOUTHERN NEW ENGLAND. THE BEST CHANCE FOR APPRECIABLE
RAIN IS MONDAY AFTERNOON THRU TUESDAY MORNING. AT THIS TIME THE
POTENTIAL EXISTS FOR 0.5 TO AROUND 1.0 INCH OF RAINFALL.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EDT SATURDAY FOR ANZ255-256.
&&
$$
SYNOPSIS...WTB/EVT
NEAR TERM...WTB/EVT
SHORT TERM...WTB
LONG TERM...EVT
AVIATION...WTB/EVT
MARINE...WTB/EVT
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
141 PM EDT FRI APR 22 2016
.Aviation...
[Through 18Z Saturday] Numerous SHRA and isolated TSRA will
continue to affect south GA, southeast AL, and the FL Panhandle
and Big Bend this afternoon. The rain will end this evening, but
low clouds and fog (IFR) will develop later tonight across much of
the region. A cold front will pass through the area Saturday
morning, eventually clearing the clouds and fog late in the
morning.
&&
.Prev Discussion [909 AM EDT]...
.Near Term [Through Today]...
The 7 am EDT regional surface analysis showed a cold front from
northeast MS to the coastal waters of TX. Vapor imagery and upper
air data showed a positive-tilted trough approaching from the
west. There was an MCS propagating eastward across the FL
Panhandle and Southeast AL, which the latest HRRR appears to have
initialized fairly well. This system is expected to weaken a bit
as it moves into a region with less favorable thermodynamics, but
we are still forecasting high rain chances across most of our area
this afternoon given the expected Q-G forcing and moisture ahead
of the approaching trough. Forecast max MLCAPE values will be
around 1000 J/kg, and 0-6 km bulk shear values will be in the
20-30 KT range. These levels are marginal for storm
organization/strong updrafts, but we can`t rule out a marginally
damaging wind gust.
.Short Term [Tonight Through Sunday]...
The frontal boundary will be clearing the area tonight with
showers and thunderstorms rapidly decreasing after sunset.
Thereafter, dry conditions will prevail through the weekend with
temperatures near to slightly above average, generally low to mid
80s for highs and upper 50s to lower 60s for lows.
.Long Term [Sunday Night Through Friday]...
A rather dry and warm pattern will dominate through next week with
weak upper level ridging in place over the southeast. Expect to
see highs in the lower to mid 80s with lows in the 60s throughout
the period.
.Marine...
Generally light winds will shift to the northwest tonight behind a
cold frontal passage. Winds and seas are expected to remain on
the low side through early next week. A sea breeze is possible
near the coast on Saturday afternoon as well as Sunday afternoon.
.Fire Weather...
Aside from high dispersion values Saturday, there are no fire
weather concerns at least for the next several days.
.Hydrology...
Steady or falling river levels are expected through this weekend.
Rainfall amounts with today`s frontal system are expected to
average generally less than 1 inch for most areas with no
significant impacts on area rivers.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 62 85 58 87 61 / 10 0 0 0 0
Panama City 65 79 63 80 64 / 10 0 0 0 0
Dothan 58 82 57 85 60 / 30 0 0 0 0
Albany 58 83 57 84 60 / 40 0 0 0 0
Valdosta 61 86 58 88 60 / 30 0 0 0 0
Cross City 63 84 59 86 61 / 10 0 0 0 0
Apalachicola 64 80 62 79 64 / 10 0 0 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AL...NONE.
GM...NONE.
&&
$$
NEAR TERM...FOURNIER
SHORT TERM...DVD
LONG TERM...DVD
AVIATION...FOURNIER
MARINE...DVD
FIRE WEATHER...BARRY
HYDROLOGY...DVD
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
322 PM EDT FRI APR 22 2016
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
CONVECTION CONTINUES TO INCREASE ACROSS AL...ERN TN AND NW GA. SO
FAR NOTHING TOO BAD WITH A COUPLE SIG WX ADVISORIES ISSUED OVER
NRN AL. CURRENT TEMPS STILL IN THE UPPER 60S TO AROUND 70 AND
DEWPOINTS AROUND 60. RESULTING SBCAPE OVER ERN AL AND FAR NW GA
STILL LIMITED TO 500-1000 J/KG AND VERTICAL WIND SHEAR QUITE WEAK.
LOW END DAMAGING WIND AND SMALL HAIL THREAT APPEARS TO BE IN LINE
WITH SPC MARGINAL RISK BUT WILL CONTINUE TO MONITOR.
EXPECT ISOLD TO SCT /20-40PCT/ COVERAGE OF STORMS REST OF
AFTERNOON THRU 10 PM OR SO TONIGHT BEFORE DIMINISHING. SO POPS
APPEAR OK. ALL PRECIP SHOULD BE OUT OF CWA BY MIDNIGHT.
NO FCST PROBLEMS EXPECTED THRU REST OF SHORT TERM FCST PERIOD.
IF WINDS DIE DOWN TONIGHT...AS SOME MOS FORECASTS INDICATE...COULD
SEE PATCHY GROUND FOG.
TEMPERATURES NEAR OR ABOVE NORMAL THIS WEEKEND. BLEND
INCORPORATING BIAS CORRECTION AND RECENT PERFORMANCE GENERALLY
ACCEPTED.
SNELSON
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
NLISTEMAA
NO MAJOR CHANGES TO THE LONG TERM PORTION OF THE FORECAST WERE
NEEDED. TWO SYSTEMS ARE EXPECTED TO IMPACT THE CWFA...ONE DURING THE
MIDDLE PART OF THE WEEK WITH THE NEXT SYSTEM EXPECTED FOR FRIDAY
INTO THE EARLY WEEKEND.
HIGH PRESSURE WILL REMAIN ACROSS THE WESTERN ATLANTIC THROUGH
TUESDAY. HOWEVER, THE HIGH CENTER WILL GET SHIFTED TO THE SOUTH AND
EAST BY LATE TUESDAY/EARLY WEDNESDAY AS A FRONTAL BOUNDARY
APPROACHES FROM THE NORTH. THE 500MB FLOW WILL REMAIN ZONAL THROUGH
THROUGH THE END OF THE WEEK...SO THE BOUNDARY SHOULD NOT MAKE IT TOO
FAR INTO THE NORTHERN CWFA BEFORE STALLING. THE HIGHEST POPS FOR THE
MIDDLE PART OF THE WEEK SHOULD BE IN THE VICINITY OF THIS BOUNDARY.
CURRENTLY...THE LONG TERM MODELS HAVE THE NEXT BOUNDARY IMPACTING
THE CWFA ON FRIDAY INTO EARLY SATURDAY.
NLISTEMAA
PREV LONG TERM DISCUSSION /SATURDAY NIGHT THROUGH THURSDAY/...
/ISSUED 344 AM EDT FRI APR 22 2016/
LONG TERM PERIOD BEGINS WITH LAST OF THE SHORTWAVE ENERGY EXITING
EAST AND TAKING ALL OF THE DEEP LAYER MOISTURE WITH IT. WITH
TIME...THROUGH SUNDAY...THE TROUGH WILL BE REPLACED BY AND UPPER
LEVEL RIDGE PROVIDING FOR A DRY PATTERN AND INCREASING
TEMPERATURES. BY SUNDAY AFTERNOON...MOST LOCATIONS WILL BE
APPROACHING THE 80 DEGREE MARK ONCE AGAIN WHICH WILL BE SOME 3 TO
5 DEGREES ABOVE SAT VALUES.
A FAIRLY STAGNANT PATTERN IN STORE THROUGH MONDAY NIGHT AS UPPER
RIDGE DOMINATES FOR MOST OF THE PERIOD BUT DOES BREAK DOWN INTO
MORE OF A ZONAL FLOW BY TUE MORNING. SURFACE RIDGE WILL GRADUALLY
SHIFT FROM THE CAROLINAS TO WELL OFFSHORE WHICH WILL PROMOTE MORE
OF A MOIST SOUTHERLY FLOW ACROSS THE AREA. IMPULSES MOVING QUICKLY
ACROSS THE SOUTH WILL EVENTUALLY IMPACT PORTIONS OF NORTH GEORGIA
TUESDAY AFTERNOON. MOISTURE WILL CONTINUE TO BE LIMITED BUT ENOUGH
LIFT AND INSTABILITY PRESENT TO WARRANT LOW END CHANCE POPS ACROSS
THE FAR NORTHERN TIER.
WILL CONTINUE WITH THE MAINLY DIURNAL CONVECTION AND LOW END
CHANCE POPS ACROSS THE FAR NORTH THROUGH WED. THEREAFTER...A COLD
FRONT WILL SAG INTO THE STATE WITH INCREASED DEEP LAYER MOISTURE.
FRONT HOWEVER STALLS QUICKLY AS UPPER RIDGE BUILDS BACK IN AND
MOISTURE LESSENS. SOME INDICATIONS FOR LATE FRI INTO NEXT WEEKEND
OF POTENTIAL NW FLOW STORMS BUT OVERALL A BENIGN PATTERN FOR MID
SPRING.
DEESE
&&
.PREV DISCUSSION... /ISSUED 228 PM EDT FRI APR 22 2016/
UPDATE...
ALREADY DID TWEAKS TO NEAR TERM POP...WX AND SKY GRIDS BASED ON
RADAR TRENDS. HIRES MODELS AND HRRR DOING A DECENT JOB HANDLING
THE RAIN BAND AND NOW DEVELOPING ISOLD CONVECTION IN ERN AL...NW
GA AND CENTRAL/ERN TN. INSTABILITY INCREASING IN ERN AL BUT NOT
AS MUCH AS FEARED EVEN THOUGH TEMPS AROUND 80F IN COUNTIES SOUTH
AND EAST OF RAIN AREA IN EC GA. ANY STORMS THAT DEVELOP OVER NW GA
THIS AFTERNOON COULD HAVE SOME STRONG WINDS AND SMALL HAIL THREAT.
SNELSON
&&
AVIATION...
18Z UPDATE...
SEVERAL ISSUES WITH FORECAST...IFR CIGS FINALLY DISSIPATING IN
RAIN AREA. STUBBORN TO CLEAR OUT OF KCSG BUT MOST OTHER AREAS MVFR
OR VFR AT THIS TIME. SFC WINDS MOSTLY SW BUT MAY BRIEFLY SWITCH TO
SE ON BACK SIDE OF RAIN AREA MOVING THROUGH. ISOLD TSRA EXPECTED
TO INCREASE OVER NW 1/2 OF GA THRU 23Z. EXPECTED COVERAGE JUST
ENOUGH TO WARRANT TEMPO FOR 21-24Z AT ATL METRO AIRPORTS. RAPID
CLEARING EXPECTED AFTER 02Z BUT COULD SEE PATCH GROUND FOG AFTER
10Z WHERE WINDS GO CALM AND PREVIOUS RAINFALL SLOW TO EVAPORATE.
SFC WINDS WILL REMAIN ON WEST COMPONENT THRU FCST. NO SIGNIFICANT GUSTS
EXPECTED.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON TSRA LIKELIHOOD AND LOCATIONS.
MEDIUM CONFIDENCE ON FOG OVERNIGHT.
HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
SNELSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 55 78 54 79 / 40 0 0 0
ATLANTA 56 75 56 78 / 40 0 0 0
BLAIRSVILLE 52 72 49 76 / 50 0 0 0
CARTERSVILLE 53 74 51 79 / 30 0 0 0
COLUMBUS 57 77 56 81 / 40 0 0 0
GAINESVILLE 55 75 54 77 / 40 0 0 0
MACON 57 78 55 81 / 40 0 0 0
ROME 54 75 51 79 / 30 0 0 0
PEACHTREE CITY 53 76 52 79 / 50 0 0 0
VIDALIA 62 80 59 82 / 40 5 0 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SNELSON
LONG TERM....NLISTEMAA
AVIATION...SNELSON
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
228 PM EDT FRI APR 22 2016
.UPDATE...
ALREADY DID TWEAKS TO NEAR TERM POP...WX AND SKY GRIDS BASED ON
RADAR TRENDS. HIRES MODELS AND HRRR DOING A DECENT JOB HANDLING
THE RAIN BAND AND NOW DEVELOPING ISOLD CONVECTION IN ERN AL...NW
GA AND CENTRAL/ERN TN. INSTABILITY INCREASING IN ERN AL BUT NOT
AS MUCH AS FEARED EVEN THOUGH TEMPS AROUND 80F IN COUNTIES SOUTH
AND EAST OF RAIN AREA IN EC GA. ANY STORMS THAT DEVELOP OVER NW GA
THIS AFTERNOON COULD HAVE SOME STRONG WINDS AND SMALL HAIL THREAT.
SNELSON
&&
.PREV DISCUSSION... /ISSUED 803 AM EDT FRI APR 22 2016/
SHORT TERM /TODAY THROUGH SATURDAY/...
NEAR TERM MAINLY WITH PRE-FRONTAL MIDLEVEL WAVE OF MOISTURE ALLOWING
FOR SCATTERED SHOWERS PUSHING ACROSS PORTIONS OF NORTH GEORGIA EARLY
THIS MORNING...THOUGH GREATEST CHANCE WILL BE THIS AFTERNOON INTO
EVENING AHEAD AND ALONG RATHER HIGH AMPLITUDE UPPER SHORTWAVE TROUGH
AND TRANSLATED SFC FROPA. HAVE TRENDED LIKELY POPS ACCORDINGLY WITH
GREATEST CHANCE CENTERED IN THE 15-21Z WINDOW. PROGGED CAPE VALUES
LOOK TO INCREASE ENOUGH FOR GENERAL CHANCE THUNDER THOUGH LOOK TO
REMAIN BELOW 1000 J/KG EVEN WITH THE MU PARCEL. ANY LINGERING CLOUD
COVERAGE AHEAD OF SYSTEM MAY ALSO SERVE TO LIMIT DESTABILIZATION...
THOUGH WILL HAVE MARGINAL DEEP LAYER SHEAR NEAR 30-35 KTS AND RATHER
LOW FRZING LEVEL WITH DECENT LOW LEVEL LAPSE RATES SO SOME STRONG
STORMS...POSSIBLY LOW END SEVERE COULD DEVELOP. GUSTY
WINDS...HAIL...AND FREQUENT LIGHTNING WOULD BE MAIN THREATS THIS
AFTERNOON WITH STRONGER CONVECTION. OTHERWISE LOOKING TO HAVE
CLEARING SKIES OVERNIGHT TONIGHT WITH UPPER RIDGING AND POST-FRONTAL
REGIME. ENHANCED GRADIENT NW WINDS ON TAP FOR SATURDAY WITH DRY
CONDITIONS.
TEMPS SHOULD STAY SLIGHTLY BELOW NORMAL TODAY THEN ACTUALLY A BIT
WARMER CLOSER TO OR SLIGHTLY ABOVE NORMAL FOR SATURDAY WITH DECENT
DIURNAL HEATING DESPITE THE FROPA.
BAKER
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
LONG TERM PERIOD BEGINS WITH LAST OF THE SHORTWAVE ENERGY EXITING
EAST AND TAKING ALL OF THE DEEP LAYER MOISTURE WITH IT. WITH
TIME...THROUGH SUNDAY...THE TROUGH WILL BE REPLACED BY AND UPPER
LEVEL RIDGE PROVIDING FOR A DRY PATTERN AND INCREASING
TEMPERATURES. BY SUNDAY AFTERNOON...MOST LOCATIONS WILL BE
APPROACHING THE 80 DEGREE MARK ONCE AGAIN WHICH WILL BE SOME 3 TO
5 DEGREES ABOVE SAT VALUES.
A FAIRLY STAGNANT PATTERN IN STORE THROUGH MONDAY NIGHT AS UPPER
RIDGE DOMINATES FOR MOST OF THE PERIOD BUT DOES BREAK DOWN INTO
MORE OF A ZONAL FLOW BY TUE MORNING. SURFACE RIDGE WILL GRADUALLY
SHIFT FROM THE CAROLINAS TO WELL OFFSHORE WHICH WILL PROMOTE MORE
OF A MOIST SOUTHERLY FLOW ACROSS THE AREA. IMPULSES MOVING QUICKLY
ACROSS THE SOUTH WILL EVENTUALLY IMPACT PORTIONS OF NORTH GEORGIA
TUESDAY AFTERNOON. MOISTURE WILL CONTINUE TO BE LIMITED BUT ENOUGH
LIFT AND INSTABILITY PRESENT TO WARRANT LOW END CHANCE POPS ACROSS
THE FAR NORTHERN TIER.
WILL CONTINUE WITH THE MAINLY DIURNAL CONVECTION AND LOW END
CHANCE POPS ACROSS THE FAR NORTH THROUGH WED. THEREAFTER...A COLD
FRONT WILL SAG INTO THE STATE WITH INCREASED DEEP LAYER MOISTURE.
FRONT HOWEVER STALLS QUICKLY AS UPPER RIDGE BUILDS BACK IN AND
MOISTURE LESSENS. SOME INDICATIONS FOR LATE FRI INTO NEXT WEEKEND
OF POTENTIAL NW FLOW STORMS BUT OVERALL A BENIGN PATTERN FOR MID
SPRING.
DEESE
&&
.AVIATION...
18Z UPDATE...
SEVERAL ISSUES WITH FORECAST...IFR CIGS FINALLY DISSIPATING IN
RAIN AREA. STUBBORN TO CLEAR OUT OF KCSG BUT MOST OTHER AREAS MVFR
OR VFR AT THIS TIME. SFC WINDS MOSTLY SW BUT MAY BRIEFLY SWITCH TO
SE ON BACK SIDE OF RAIN AREA MOVING THROUGH. ISOLD TSRA EXPECTED
TO INCREASE OVER NW 1/2 OF GA THRU 23Z. EXPECTED COVERAGE JUST
ENOUGH TO WARRANT TEMPO FOR 21-24Z AT ATL METRO AIRPORTS. RAPID
CLEARING EXPECTED AFTER 02Z BUT COULD SEE PATCH GROUND FOG AFTER
10Z WHERE WINDS GO CALM AND PREVIOUS RAINFALL SLOW TO EVAPORATE.
SFC WINDS WILL REMAIN ON WEST COMPONENT THRU FCST. NO SIGNIFICANT GUSTS
EXPECTED.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON TSRA LIKELIHOOD AND LOCATIONS.
MEDIUM CONFIDENCE ON FOG OVERNIGHT.
HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
SNELSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 72 55 78 55 / 70 40 0 0
ATLANTA 71 56 76 57 / 80 20 0 0
BLAIRSVILLE 67 51 73 50 / 80 30 0 0
CARTERSVILLE 72 52 75 51 / 70 20 0 0
COLUMBUS 74 57 78 55 / 80 30 0 0
GAINESVILLE 69 55 75 55 / 90 30 0 0
MACON 77 57 78 54 / 70 40 0 0
ROME 74 53 75 51 / 60 20 0 0
PEACHTREE CITY 72 53 76 52 / 80 30 0 0
VIDALIA 82 61 80 58 / 70 50 0 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SNELSON
LONG TERM....NLISTEMAA
AVIATION...SNELSON
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1207 PM CDT FRI APR 22 2016
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 300 AM CDT FRI APR 22 2016
07Z water vapor imagery showed an upper trough over IL moving to the
east and an upper low off the OR coast. In between these two lows
was an upper ridge along the Rockies. Surface obs showed a weak
ridge of high pressure gradually building south through the central
plains.
The forecast continues to call for dry weather today and tonight due
to no real forcing for precip within the upper ridge. Additionally
there should be some modest dry air advection with the surface ridge
through the day preventing any real chance for precip. There is an
area of low clouds moving south through the MO river valley. RAP and
NAM progs show these clouds should hold together long enough to move
into northeast KS this morning. Otherwise there should be good
insolation by the afternoon. Because of this and with forecast
soundings mixing the boundary layer to near 800 MB, have adjusted
highs for today up a little from the prev forecast expecting
readings between 70 and 75. The surface ridge is progged to move off
to the east tonight with winds freshening from the southeast.
Although the gradient does not appear to be all that strong.
Therefore think low lying areas may decouple with winds remaining
fairly light through the night allowing lows to fall into the mid
40s. Elevated locations may see enough wind through the night for
lows to be around 50.
.LONG TERM...(Saturday through Thursday)
Issued at 300 AM CDT FRI APR 22 2016
Only minor edits to the extended forecast with model guidance
remaining fairly similar to the previous forecast package. Upper
ridging in control with a developing sfc trough to the west Saturday
afternoon will bring gusty south winds to the CWA. Speeds between 15
and 25 mph are likely with gusts peaking at 30 to 35 mph. Gulf
moisture increases dewpoints to the 50s while highs warm back into
the upper 70s and lower 80s. Chances for thunderstorms commence
Saturday evening as a lee trough lifts eastward over the western
plains. GFS and NAM runs at 00Z continue to advertise a slightly
faster progression of the sfc low and weak upper impulse, developing
scattered showers and thunderstorms over north central Kansas
overnight. The ECMWF is slightly slower with these features with the
optimal chances arriving Mon at 12Z. Have adjusted pops accordingly,
increasing the probabilities Sunday afternoon and evening as the
upper trough axis crosses southern NE, while the sfc low and dryline
are depicted similarly over central Kansas 00Z Monday. Steepening
lapse rates and warm moist conditions ahead of the system translate
up to 2000 J/KG of sfc based CAPE with little CIN to prevent
thunderstorm development. Main uncertainty will be mesoscale in
nature such as cloud cover and morning precip which could hinder
severity of convection overnight. However, with this setup any
updraft that does form in the late afternoon will likely be severe
with speed shear up to 6 km near 40 kts. 0-1 km shear enhances with
the LLJ by 00Z as well increasing the threat for tornadoes with any
isolated convection. Otherwise large hail and damaging winds are the
most likely hazards as convection is likely to congeal into a line
as tracks over the CWA Sunday evening.
The passing frontal boundary is still hanging up over southeast
Kansas on Monday with the GFS and ECMWF generating additional
convection Monday evening near the boundary over far east central
and southeast Kansas. Enough MUCAPE and effective shear in this area
will support a few strong to severe storms.
Long term models are still advertising a possible severe weather
event for a portion of the central plains region Tuesday afternoon
and evening as a strong negatively tilted trough lifts out of the
Inter-mountain West. Main discrepancies lie with the exact position
of the frontal boundary and timing of the approaching system as the
boundary lifts northward as a warm front through the day. ECMWF is
faster with the sfc low, lifting the warm front further north
with convection, placing the boundary over northern KS and most of
the CWA within the warm sector. The GFS however is still showing the
warm front bisecting the CWA west to east by 00Z with severe
convection focusing along and north of the boundary. er north with
the dryline centered over central KS. Meanwhile the slower GFS has
been persistent with the warm front bisecting the CWA from west to
east by 00Z Monday. GFS has also been the stronger solution with
over 2000 J/KG of sfc CAPE, minimal CIN and 0-6 KM bulk shear up to
50 kts. Lower lvl shear is stronger as well, enhancing the tornado
threat. Will need to keep monitoring changes, but it does appear
likely for a few severe storms in the area and have increased precip
chances during this period.
The remainder of the extended is more uncertain as the upper low
slowly exits eastward and dry conditions return on Thursday. Next
upper trough appears slower with this package so have backed off on
pops for Thursday at this time.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon)
Issued at 1156 AM CDT FRI APR 22 2016
For the 18z TAFs, VFR conditions should hold for the afternoon
into the evening as current stratus deck continues to erode with
the heating of the day. Not confident enough at this point to add
fog for the 11-13Z time frame in the morning. However, there is a
possibility for some reduced VIS and patchy FG around 12Z mainly
at KTOP/KFOE. Have left mention out of the TAFs for now, but this
will be something to monitor TAFs for if decoupling allows for the
set up to occur. Winds will increase by late morning from the
SSE.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Wolters
LONG TERM...Bowen
AVIATION...Drake
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
353 PM EDT FRI APR 22 2016
.SYNOPSIS...
A COLD FRONT PUSHES ACROSS THE AREA AND OFF THE COAST TONIGHT
INTO EARLY SATURDAY MORNING. AN UPPER LEVEL DISTURBANCE WILL DROP
THROUGH THE REGION SATURDAY. HIGH PRESSURE RETURNS SATURDAY NIGHT
THROUGH MONDAY. THE NEXT COLD FRONT DROPS ACROSS THE REGION
TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
LATEST GOES WATER VAPOR IMAGERY DEPICTS THE UPPER CLOSED LOW OVER
THE OH VALLEY THIS AFTERNOON WITH A PLUME OF MOISTURE EXTENDING
ALONG THE SOUTHEAST COASTAL PLAIN INTO THE LOCAL AREA. THE COLD
FRONT STILL LAGS OVER CENTRAL OH/KY/TN. LATEST REGIONAL RADAR
DEPICTS BROAD AREA OF SHOWERS EAST OF INTERSTATE 95 WITH SCATTERED
SHOWERS WEST. ONLY LINGER THUNDER REMAINS OVER THE ERN SHORE NEAR
THE COAST. THE NEXT BATCH OF SHOWERS AND EMBEDDED THUNDER IS LOCATED
OVER CENTRAL AND EASTERN NC. HI-RES GUIDANCE LIFTS THE SHOWERS INTO
THE SE HALF OF THE LOCAL AREA THRU THE REST OF THE AFTERNOON.
ANOTHER AREA OF SHOWERS ASSOCIATED WITH THE NEXT PLUME OF MOISTURE
AND THE UPPER LOW PUSHES INTO THE PIEDMONT...BUT IS EXPECTED TO
REMAIN SCATTERED. SHOWERS HAVE LIMITED WHAT LITTLE INSTABILITY THERE
WAS...BUT TEMPS REMAIN IN THE MID 70S ACROSS NE NC. RAP GUIDANCE
INDICATES MLCAPE VALUES AROUND 500 J/KG. WILL KEEP MENTION OF CHANCE
THUNDER WITH LIKELY POPS. PRECIP BEGINS TO TAPER OFF INLAND THIS
EVENING AS THE COLD FRONT APPROACHES. EXPECT ONLY SCATTERED SHOWERS
ALONG THE FRONT AS IT REACHES THE AREA AROUND MIDNIGHT. YET ANOTHER
WAVE CURRENTLY ASSOCIATED WITH PRECIP OVER GA/SC IS PROGGED TO LIFT
INTO THE SE LOCAL AREA OVERNIGHT. THE ADDED LIFT FROM THE
APPROACHING UPPER LOW AND COLD FRONT WILL ENHANCE PRECIP ACROSS THE
SE VA/NE NC AGAIN. LIKELY POPS PREVAIL ALONG THE COAST THRU THE
OVERNIGHT.
MILD TEMPS EXPECTED OVERNIGHT WITH CLOUDS/PRECIP. LOWS GENERALLY IN
THE MID/UPPER 50S INLAND TO LOW 60S SOUTHEAST.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SFC FRONT PUSHES OFFSHORE SAT MORNING AS THE UPPER LEVEL FRONT LAGS
BEHIND. SHORTWAVE DROPS OVER THE LOCAL AREA SAT AFTERNOON...PUSHING
OFFSHORE SAT EVENING. PWATS DROP TO AOB 1 INCH SAT...BUT CROSS
SECTIONS AND BUFR SOUNDINGS INDICATE REMNANT MID LEVEL MOISTURE.
ADDED FORCING FOR ASCENT AND SHARPENING LAPSE RATES AS COLDER AIR
ALOFT ADVECTS INTO THE REGION WILL RESULT IN ONGOING CHANCES FOR
SHOWERS SAT MORNING. THE BEST CHANCES WILL BE ALONG THE COAST...BUT
STILL EXPECT LIGHT SHOWERS INLAND. MOISTURE REMAINS RATHER
SHALLOW...SO EXPECT ONLY A FEW TENTHS OF AN INCH AT BEST. NLY WINDS
INCREASE TO 10 TO 15 MPH SAT AFTERNOON WITH CLEARING SKIES NW TO SE
THRU THE AFTERNOON. MODEST CAA (AT BEST) AND MIXING WILL PUSH TEMPS
BACK INTO THE LOW/MID 70S (COOLER ALONG THE COAST).
UPPER/SFC HIGH PRESSURE BUILDS OVER THE REGION SAT NIGHT...LOCATING
OVER THE MID ATLANTIC REGION SUN. EXPECT A CLEAR/SUNNY SKY WITH
SEASONABLE TEMPERATURES. LOWS SAT NIGHT IN THE MID/UPPER 40S TO LOW
50S AND HIGHS SUN IN THE LOW 70S INLAND AND MID/UPPER 60S NEAR THE
COAST. LIGHT ONSHORE FLOW WILL RESULT IN TEMPS IN THE UPPER 50S
ALONG THE IMMEDIATE COAST. THE HIGH PUSHES OFFSHORE SUN NIGHT WITH
SLY/RETURN FLOW FORECAST INTO MONDAY. LOWS SUN NIGHT IN THE UPPER
40S TO LOW 50S. SUNNY MONDAY AND WARM AS H85 TEMPS WARM TO AROUND
12C (+1 STD DEV). THICKNESSES YIELD TEMPS IN THE LOW/MID 80S UNDER A
SUNNY SKY. HIGH CLOUDS MAY INCREASE LATE MON AS THE NEXT COLD FRONT
APPROACHES THE REGION FROM THE NW.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
HIGH PRESSURE SETTLES OFF THE SOUTHEAST COAST BY TUESDAY.
MEANWHILE...A SHORTWAVE TROUGH AND AN ASSOCIATED COLD FRONT APPROACH
FROM THE NW BY TUESDAY AFTN. TUESDAY CONTINUES TO TREND TOWARD BEING
A VERY WARM DAY WITH DEEP LAYER WSW FLOW ASSOCIATED WITH A BREAKING
DOWN UPPER RIDGE OVER THE E-CENTRAL/SERN CONUS. MODEL CONSENSUS
GENERALLY SUPPORTS 850MB TEMPERATURES OF 12-15C...WHICH WITH FULL
MIXING AND DOWNSLOPING SHOULD EASILY PUSH HIGHS TO THE LOW/MID 80S W
OF THE BAY...WITH UPPER 70S FOR THE ERN SHORE...AFTER MORNING LOWS
IN THE UPPER 50S TO LOW 60S. SKY COVER SHOULD GENERALLY BE MOSTLY
CLEAR MONDAY NIGHT...AND BECOME PARTLY SUNNY BY TUESDAY. THE TROUGH
AND COLD FRONT SWING THROUGH THE AREA TUESDAY AFTN INTO TUESDAY
NIGHT. THE MAIN FORCING ASSOCIATED WITH THE MID/UPPER SHORTWAVE
TROUGH GENERALLY PASSES N OF THE LOCAL AREA...AND DEEP LAYER RH
DIMINISHES AS THE FEATURE PASSES OVER THE LOCAL AREA SO FORECAST
POPS FOR SHOWERS/TSTMS REMAIN ~20%...WITH A STRIP OF 30% ACROSS THE
FAR N...AND 40% FOR THE LOWER MD ERN SHORE. HIGH PRESSURE BUILDS IN
FROM THE N WEDNESDAY...AND SLIDES OFFSHORE THURSDAY. HIGHS WEDNESDAY
SHOULD DROP BACK TO THE MID/UPPER 60S NE...TO THE MID/UPPER 70S
FARTHER INLAND...AND THEN TREND UPWARD THURSDAY INTO THE MID 70S TO
LOW 80S AS THE HIGH SLIDES OFFSHORE. LOWS SHOULD GENERALLY BE IN THE
50S. A WEAK COLD FRONT SWINGS ACROSS THE AREA LATER IN THE WEEK WITH
ONLY A MINIMAL CHC FOR SHOWERS/TSTMS.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
CONVECTION HAS DEVELOPED THIS AFTERNOON IN THE WARM MOIST
SOUTHERLY FLOW AHEAD OF A COLD FRONT...THAT IS MOVING THROUGH
EASTERN OH/KY AT 18Z. THE MAIN BAND OF CONVECTION HAS MOVED
THROUGH RIC AND IS NOW IMPACTING THE DELMARVA AND AREAS FURTHER
SOUTH. BEHIND THIS BAND OF CONVECTION MORE SHOWERS ARE
POSSIBLE...BUT ARE NOT EXPECTING TO SEE THUNDER FOR RIC. ONCE THE
MAIN BAND CLEARS THROUGH SBY BY 20Z...AGAIN COULD SEE MORE SHOWERS
BUT THE BETTER LIFT AND INSTABILITY WILL THEN SETTLE TO THE SOUTH.
WITH THE CONVECTION EXPECT TO SEE BRIEF PERIODS OF MVFR TO IFR
CONDITIONS WITH MAINLY MVFR TO VFR CONDITIONS IN THE SHOWERS.
THERE IS ALSO A SHORTWAVE TROUGH IN THE SOUTHERN STREAM THAT IS
SLIDING ACROSS AL/GA. THIS WAVE WILL GET PULLED NORTHWARD AHEAD OF
THE NORTHERN STREAM TROUGH TONIGHT AND WILL KEEP THE THREAT FOR
RAIN/STORMS ON GOING THROUGH THE EVENING INTO THE OVERNIGHT HOURS
FOR THE VA TIDEWATER AND NERN NC. AGAIN EXPECT MVFR TO IFR
CONDITIONS IN THE SHOWERS/THUNDERSTORMS.
AFTER 6Z...EXPECT THE BEST FORCING TO MOVE OFF THE COAST AND WITH
THE WINDS EXPECTED TO WEAKEN...WILL SEE A VERY MOIST ATMOSPHERE
WILL LITTLE STIRRING...WHICH SHOULD ALLOW LOW STRATUS TO FORM WITH
SOME MINOR FOG...SO HAVE A PERIOD OF MVFR VIS/IFR CEILINGS UNTIL
THE FRONT CROSSES THE AREA BETWEEN ABOUT 10Z AND 15Z SATURDAY.
ONCE THE FRONT CLEARS AND THE WINDS START TO PICK UP FROM THE
NORTHWEST...EXPECT TO SEE IMPROVING CEILINGS AND VISIBILITIES AS
DRIER AIR MOVES IN FROM THE NORTHWEST. ANY LINGERING SHOWERS WITH
THE UPPER LOW ARE EXPECT TO IMPACT THE DELMARVA LOCATIONS SATURDAY
AFTERNOON WITH SOME MVFR LEVEL SHOWERS.
OUTLOOK SAT NIGHT THROUGH WEDNESDAY...HIGH PRESSURE RETURNS SAT
NIGHT THROUGH MONDAY NIGHT WITH MAINLY VFR CONDITIONS EXPECTED. A
COLD FRONT WILL SLIDE THROUGH FROM THE NORTH LATE ON TUESDAY...BUT
LOOKS MOISTURE STARVED. HIGH PRESSURE BUILDS IN AGAIN ON
WEDNESDAY. THROUGH THE OUTLOOK PERIOD....EXPECT MAINLY VFR
CONDITIONS.
&&
.MARINE...
HIGH PRESSURE IS SITUATED WELL OFFSHORE THIS AFTN...WITH A
COLD PUSHING TOWARD THE WRN SLOPES OF THE APPALACHIANS. MOISTURE
AHEAD OF THE FRONT HAS TRIGGERED SHOWERS/TSTMS ACROSS THE MARINE
AREA THIS AFTN...WITH A FEW CELLS PRODUCING WIND GUSTS TO 30-40KT.
THE COLD FRONT SLOWLY APPROACHES FROM THE W TONIGHT...AND PUSHES
THROUGH THE AREA SATURDAY MORNING...WITH A SUBSEQUENT NORTHERLY
SURGE SATURDAY AFTN...WITH A SECONDARY SURGE SATURDAY EVENING
THROUGH THE OVERNIGHT HOURS. LOW-END SCA CONDITIONS ARE EXPECTED
OVER THE BAY WITH A 15-20KT N WIND...LIKELY IN TWO SURGES...ONE
SATURDAY AFTN...AND THE OTHER LATER SATURDAY EVENING THROUGH THE
OVERNIGHT HOURS. AN SCA FLAG HAS BEEN RAISED FOR THE BAY TO ACCOUNT
FOR THIS. THE OCEAN IS GENERALLY EXPECTED TO REMAIN SUB-
SCA...ALTHOUGH SEAS COULD BRIEFLY REACH ~5FT OFF THE CURRITUCK OUTER
BANKS LATER SATURDAY NIGHT INTO EARLY SUNDAY AS THE WIND BECOMES
MORE NNE. HIGH PRESSURE BUILDS OVER THE AREA SUNDAY...SLIDES
OFFSHORE MONDAY...AND SETTLES OFF THE SOUTHEAST COAST TUESDAY. SEAS
GENERALLY AVERAGE 2-4FT...WITH 2-3FT WAVES IN THE BAY. ANOTHER COLD
FRONT CROSSES THE AREA TUESDAY NIGHT INTO WEDNESDAY.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM SATURDAY TO 7 AM EDT SUNDAY FOR
ANZ632-634.
SMALL CRAFT ADVISORY FROM 1 PM SATURDAY TO 4 AM EDT SUNDAY FOR
ANZ630-631.
&&
$$
SYNOPSIS...SAM
NEAR TERM...SAM
SHORT TERM...SAM
LONG TERM...AJZ
AVIATION...ESS
MARINE...AJZ
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
241 PM EDT FRI APR 22 2016
.SYNOPSIS...
A COLD FRONT APPROACHES FROM THE WEST TODAY. THE COLD FRONT PUSHES
ACROSS THE AREA AND OFF THE COAST TONIGHT INTO EARLY SATURDAY
MORNING. AN UPPER LEVEL DISTURBANCE WILL DROP THROUGH THE REGION
DURING SATURDAY. HIGH PRESSURE RETURNS FOR SATURDAY NIGHT THROUGH
MONDAY. THE NEXT COLD FRONT DROPS ACROSS THE REGION TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST REGIONAL RADAR MOSAIC DEPICTS AN AREA OF SHOWERS LIFTING NEWD
INTO THE ERN VA PIEDMONT LATE THIS MORNING. THIS WELL IN ADVANCE OF
THE COLD FRONT...CURRENTLY LOCATED OVER THE OH VALLEY. AREA OF
SHOWERS MATCHES UP WELL WITH ISENTROPIC LIFT IN THE 300K SFC. MODEST
HEIGHT FALLS AND INCREASING WINDS ALOFT HAVE PROVIDED FORCING FOR
ASCENT AS THE UPPER RIDGE AXIS HAS PUSHED OFFSHORE. H85 MOISTURE
TRANSPORT HAS ADVECTED PWATS OF 1.0 TO 1.25 INCHES INTO THE REGION.
FOLLOWING HI-RES GUIDANCE (WHICH HAS VERIFIED WELL SO FAR)...EXPECT
PRECIP TO LIFT INTO CENTRAL VA AROUND NOON AND THEN POINTS EWD THRU
THE AFTERNOON. RAP SBCAPE DEPICTS LIMITED INSTABILITY OVER THE
REGION THIS MORNING...SO ONLY ANTICIPATED ISOLATED THUNDER THIS
MORNING.
BETTER FORCING ARRIVES THIS AFTERNOON AS PWATS INCREASE TO AROUND
1.2 TO 1.45 INCHES (+1 STD DEV). NAM/RAP/SREF MLCAPE REMAINS
MARGINAL AT BEST...GENERALLY AOB 750 J/KG. LAPSE RATES ALSO REMAIN
MODEST AS THE COLDEST AIR ALOFT REMAINS WEST OF THE REGION
ASSOCIATED WITH THE UPPER LEVEL FRONT. EFF SHEAR ALSO AOB 30 KT.
WITH THAT SAID...ONLY EXPECT EMBEDDED/UNORGANIZED THUNDERSTORMS. HI-
RES GUIDANCE AND NAM12 300K KEEPS THE BEST LOW LEVEL FORCING OVER
THE SOUTHEAST HALF OF THE FORECAST AREA...WHERE HIGHEST POPS WILL BE
MAINTAINED. HOWEVER...EXPECT MORE SCATTERED SHOWER ACTIVITY ACROSS
THE NW...SO HAVE TRIMMED POPS BACK INTO CHANCE RANGE. THE FRONT
PUSHES ACROSS THE REGION LATE TODAY AS ADDITIONAL UPPER LEVEL
PERTURBATIONS LIFT INTO THE REGION. EXPECT ADDITIONAL COVERAGE LATE
AFTERNOON ACROSS THE SOUTHEAST HALF OF THE LOCAL AREA. WILL RETAIN
LIKELY POPS...WITH THE NW POSSIBLY SEEING A DRYING TREND. BETTER
INSTABILITY EXPECTED MID-LATE AFTERNOON (ALBEIT STILL MARGINAL)
ACROSS THE SE...SO PERHAPS A BETTER CHANCE TO SEE THUNDER.
RETURN FLOW AND BREAKS IN THE CLOUDS WILL PUSH TEMPS INTO THE UPPER
70S TO NEAR 80 EAST OF INTERSTATE 95 (COOLER ALONG THE COAST AND
BAY). TEMPS WEST OF INTERSTATE 95 WILL LEVEL OFF IN THE LOW/MID 70S
LATE THIS MORNING THRU MID AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
WITH THE UPR LO/TROF LAGGING BEHIND THE COLD FRONT...AND PLENTY OF
LO LEVEL MOISTURE/LIFT IN PLACE...NOW HAVE LIKELY POPS EVERYWHERE
INTO TNGT. HAVE ALSO KEPT SLGT CHC OF THUNDER. LATER TNGT INTO
SAT MORNG...BULK OF PCPN WILL MOVE EWRD AND OFF THE CST AS THE UPR
LO/TROF PUSHES THE COLD FRONT ACRS THE AREA AND OFFSHR. PWATS
CLIMB TO 1.25 TO 1.5 INCHES...WHICH MAY RESULT IN PERIODS OF
MODERATE TO LOCALLY HEAVY RAINFALL. HOWEVER...QPF AMTS THRU TNGT
WILL GENERALLY RANGE FM ARND .30 INCH ACRS THE N TO NEAR .60 INCH
ACRS THE S. LOWS TNGT IN THE MID 50S TO LWR 60S.
MODEL TRENDS CONTINUE TO LINGER MID LEVEL MOISTURE TO GO ALONG
WITH THE STRONG DYNAMICS PROVIDED BY THE UPR LO DROPPING THRU THE
REGION THRU SAT AFTN. WILL HOLD ONTO SOLID CHC POPS THRU LATE
MORNG INLAND FOR SCTD SHOWERS...AND ALONG SE VA/NE NC THRU SAT
AFTN. CLOUDY CONDITIONS BECOME PARTLY CLOUDY INLAND SAT
AFTN...BUT REMAIN MOSTLY CLOUDY ALNG THE CST. TRENDED TOWARD THE
COOLER SIDE OF THE MOS GUIDANCE...DUE TO CLOUD COVER AND MODEST
CAA...BUT TEMPS REMAIN SEASONABLE IN THE UPR 60S TO MID 70S. N
WINDS GENERALLY 10 TO 15 MPH WITH GUSTS OF 20 TO 25 MPH. TROF AXIS
PUSHES WELL OFFSHORE SAT NGT...WITH DRY CONDITIONS FCST ACRS THE
AREA. LOWS IN THE MID TO UPR 40S INLAND...TO THE LWR 50S NEAR THE
CST UNDER A CLEAR OR MOSTLY CLEAR SKY. HI PRES BLDS INTO THE NE
U.S. AND TWD NEW ENGLAND SAT NGT...THEN SLIDES TO JUST OFF THE NE
U.S. AND MID ATLC CST BY 00Z MON. THE RESULT WILL BE ONGOING DRY
CONDITIONS ON SUN UNDER A MOSTLY SNY SKY. HI TEMPS WILL RANGE FM
THE MID 60S TO LWR 70S OVR MOST OF THE REGION..
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE SLIDES FARTHER OFFSHORE SUNDAY NIGHT AND MONDAY...AND
SETTLES OFF THE SOUTHEAST COAST BY TUESDAY. MEANWHILE...A SHORTWAVE
TROUGH AND AN ASSOCIATED COLD FRONT APPROACH FROM THE NW BY TUESDAY
AFTN. MONDAY AND TUESDAY ARE TRENDING TOWARD BEING VERY WARM DAYS
WITH DEEP LAYER WSW FLOW ASSOCIATED WITH A BREAKING DOWN UPPER RIDGE
OVER THE E-CENTRAL/SERN CONUS. MODEL CONSENSUS GENERALLY SUPPORTS
850MB TEMPERATURES OF 12-15C...WHICH WITH FULL MIXING AND
DOWNSLOPING SHOULD EASILY PUSH HIGHS TO 80-85F W OF THE BAY...WITH
UPPER 70S FOR THE ERN SHORE. LOWS SUNDAY NIGHT SHOULD BE IN THE
LOW/MID 50S...WITH 55-60F MONDAY NIGHT. SKY COVER SHOULD GENERALLY
BE MOSTLY CLEAR/SUNNY SUNDAY NIGHT...MONDAY INTO MONDAY NIGHT...AND
BECOME PARTLY SUNNY TUESDAY. THE TROUGH AND COLD FRONT SWING THROUGH
THE AREA TUESDAY AFTN INTO TUESDAY NIGHT. THE MAIN FORCING
ASSOCIATED WITH THE MID/UPPER SHORTWAVE TROUGH GENERALLY PASSES N OF
THE LOCAL AREA...AND DEEP LAYER RH DIMINISHES AS THE FEATURE PASSES
OVER THE LOCAL AREA SO FORECAST POPS ARE ONLY 20%...WITH A NARROW
STRIP OF 30% ACROSS THE FAR N. HIGH PRESSURE BUILDS IN FROM THE N
WEDNESDAY...AND SLIDES OFFSHORE LATER IN THE WEEK. HIGHS WEDNESDAY
SHOULD DROP BACK TO THE MID/UPPER 60S NE...TO THE MID/UPPER 70S
FARTHER INLAND...AND THEN TREND UPWARD INTO THURSDAY AS THE HIGH
SLIDES OFFSHORE. LOWS SHOULD GENERALLY BE IN THE 50S.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
CONVECTION HAS DEVELOPED THIS AFTERNOON IN THE WARM MOIST
SOUTHERLY FLOW AHEAD OF A COLD FRONT...THAT IS MOVING THROUGH
EASTERN OH/KY AT 18Z. THE MAIN BAND OF CONVECTION HAS MOVED
THROUGH RIC AND IS NOW IMPACTING THE DELMARVA AND AREAS FURTHER
SOUTH. BEHIND THIS BAND OF CONVECTION MORE SHOWERS ARE
POSSIBLE...BUT ARE NOT EXPECTING TO SEE THUNDER FOR RIC. ONCE THE
MAIN BAND CLEARS THROUGH SBY BY 20Z...AGAIN COULD SEE MORE SHOWERS
BUT THE BETTER LIFT AND INSTABILITY WILL THEN SETTLE TO THE SOUTH.
WITH THE CONVECTION EXPECT TO SEE BRIEF PERIODS OF MVFR TO IFR
CONDITIONS WITH MAINLY MVFR TO VFR CONDITIONS IN THE SHOWERS.
THERE IS ALSO A SHORTWAVE TROUGH IN THE SOUTHERN STREAM THAT IS
SLIDING ACROSS AL/GA. THIS WAVE WILL GET PULLED NORTHWARD AHEAD OF
THE NORTHERN STREAM TROUGH TONIGHT AND WILL KEEP THE THREAT FOR
RAIN/STORMS ON GOING THROUGH THE EVENING INTO THE OVERNIGHT HOURS
FOR THE VA TIDEWATER AND NERN NC. AGAIN EXPECT MVFR TO IFR
CONDITIONS IN THE SHOWERS/THUNDERSTORMS.
AFTER 6Z...EXPECT THE BEST FORCING TO MOVE OFF THE COAST AND WITH
THE WINDS EXPECTED TO WEAKEN...WILL SEE A VERY MOIST ATMOSPHERE
WILL LITTLE STIRRING...WHICH SHOULD ALLOW LOW STRATUS TO FORM WITH
SOME MINOR FOG...SO HAVE A PERIOD OF MVFR VIS/IFR CEILINGS UNTIL
THE FRONT CROSSES THE AREA BETWEEN ABOUT 10Z AND 15Z SATURDAY.
ONCE THE FRONT CLEARS AND THE WINDS START TO PICK UP FROM THE
NORTHWEST...EXPECT TO SEE IMPROVING CEILINGS AND VISIBILITIES AS
DRIER AIR MOVES IN FROM THE NORTHWEST. ANY LINGERING SHOWERS WITH
THE UPPER LOW ARE EXPECT TO IMPACT THE DELMARVA LOCATIONS SATURDAY
AFTERNOON WITH SOME MVFR LEVEL SHOWERS.
OUTLOOK SAT NIGHT THROUGH WEDNESDAY...HIGH PRESSURE RETURNS SAT
NIGHT THROUGH MONDAY NIGHT WITH MAINLY VFR CONDITIONS EXPECTED. A
COLD FRONT WILL SLIDE THROUGH FROM THE NORTH LATE ON TUESDAY...BUT
LOOKS MOISTURE STARVED. HIGH PRESSURE BUILDS IN AGAIN ON
WEDNESDAY. THROUGH THE OUTLOOK PERIOD....EXPECT MAINLY VFR
CONDITIONS.
&&
.MARINE...
TOUGH CALL WRT SCA HEADLINES TODAY AS ANY CRITERIA THAT MAY BE
MET WILL BE MINIMAL AT BEST. WILL KEEP SUSTAINED WINDS IN THE BAY
CAPPED AT 15 KT FOR NOW...ALTHOUGH OCNL GUSTS TO 20 KTS WILL BE
POSSIBLE THROUGH LATE AFTERNOON. SEAS CRNTLY 3-5 FT ACROSS MD
COASTAL WATERS (3 FT NEAR SHORE BUT 5 FT NEAR 44009) SO HAVE
ISSUED A SCA ACROSS THE MD COASTAL WATERS THROUGH 14Z WITH THE
EXPECTATION THAT SEAS OUT NEAR 20 NM DROP BELOW 5 FEET LATER THIS
MORNING. ELECTED NOT TO HAVE ANY HEADLINES FOR THE CHES BAY AND
WILL DEFER TO THE DAY SHIFT IF WINDS BECOME HIGHER THAN EXPECTED.
COLD FRONT PROGGED ACROSS THE MARINE AREA SAT MORNING. LATEST
GUIDANCE SHOWING TWO CAA SURGES...ONE SAT AFTERNOON AND ANOTHER ONE
SAT NIGHT. THE SAT AFTERNOON ONE APPEARS TO BE MARGINAL AT BEST FOR
ANY SCA HEADLINE SO WILL KEEP WINDS CAPPED AT 15 KTS ATTM. THE
SECOND CAA SURGE SAT NIGHT APPEARS TO BE A BIT STRONGER WITH WINDS
INCREASING INTO THE SCA RANGE FOR A FEW HOURS OVER THE CHES BAY.
HIGH PRESSURE BUILDS OVER THE AREA SUNDAY...SLIDES OFFSHORE
MONDAY...AND SETTLES OFF THE SOUTHEAST COAST TUESDAY.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SAM/TMG
NEAR TERM...SAM
SHORT TERM...SAM/TMG
LONG TERM...AJZ
AVIATION...ESS
MARINE...MPR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
434 PM EDT FRI APR 22 2016
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 309 PM EDT FRI APR 22 2016
WV IMAGERY AND RAP ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW INTO
THE NRN LAKES ON THE PERIPHERY OF A DEEP LOW INTO NRN HUDSON BAY.
LOW LEVEL CAA WITH NRLY WINDS KEPT LOW CLOUDS ACROSS MUCH OF THE
FCST AREA INTO EARLY AFTERNOON...BUT NOW BUILDING HIGH PRES FM NW OF
LAKE SUPERIOR HAS ALLOWED FOR INFLUX OF DRIER AIR AND ERODING CLOUD
COVER MID-LATE THIS AFTERNOON. MAX TEMPS TODAY HAVE RANGED FM THE
MID TO UPPER 30S ALONG LAKE SUPERIOR TO AROUND 50F CLOSER TO THE WI
BORDER.
TONIGHT...ALTHOUGH WINDS WILL DIMINISH WITH THE SFC HIGH PRES RIDGE
SLIDING OVER THE AREA...WAA MID CLOUDS FROM SRN MANITOBA AND NRN MN
ARE EXPECTED TO SPREAD IN FM THE W OVERNIGHT DUE TO INCREASING 295-
300K ISENTROPIC ASCENT WHICH SHOULD KEEP TEMPS FROM DROPPING OFF TOO
FAR. TEMPS MAY STILL FALL INTO THE MID 20S CENTRAL AND EAST BEFORE
THE CLOUDS MOVE IN. OTHERWISE...EXPECT MIN READINGS IN THE LOWER 30S
WEST.
SAT...A WNW FLOW ALOFT WILL DOMINATE THE UPPER GREAT LAKES BETWEEN
AN UPR RIDGE AXIS IN THE PLAINS AND AN UPR TROUGH OVER ERN CANADA.
MODELS SHOW MID/HIGH CLDS CONTINUING TO SPREAD INTO UPPER MI WITH
WAA TO THE NE OF SHARPENING FNT FM THE DAKOTAS INTO MN.
HOWEVER...THE MAJORITY OF MODELS INDICATE LINGERING LLVL DRY AIR
ASSOCIATED WITH SLOWLY DEPARTING SFC HIGH PRES WL KEEP THE CWA DRY.
ONLY THE 12Z GFS SHOWS RAIN REACHING INTO THE NW CWA WHERE MODELS
INDICATE PROXIMITY TO STRONGER H7 FGEN ALONG AND NE OF SHARPENING
FRONTAL BOUNDARY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 434 PM EDT FRI APR 22 2016
BUILDING HEIGHTS OVER GREENLAND (500MB HEIGHTS UP TO 2.5 STANDARD
DEVIATIONS ABOVE CLIMATOLOGY) THRU EARLY NEXT WEEK WILL SUPPORT
TROFFING OVER SE CANADA AND FAIRLY COLD AIR FOR LATE APR ACROSS
ONTARIO AND QUEBEC. AS A RESULT...A RATHER SHARP BAROCLINIC ZONE
WILL SET UP ACROSS THE UPPER LAKES BTWN THE LATE SEASON COLD AIR
EXPANDING ACROSS SE CANADA AND WARM AIR SPREADING ACROSS THE PLAINS
AHEAD OF A SRN STREAM SHORTWAVE LIFTING OUT OF A MEAN TROF OVER THE
CNTRL/SRN ROCKIES. THIS BAROCLINIC ZONE WILL SET THE STAGE FOR
ACTIVE WEATHER AND POTENTIAL OF MDT TO EVEN HVY PCPN AMOUNTS IN THE
SUN/MON TIME FRAME. GIVEN THE PROXIMITY OF THE COLD AIR...IT`S NOT
OUT OF THE QUESTION THAT ACCUMULATING WET SNOW COULD ALSO OCCUR IN
SOME AREAS OF UPPER MI. LATER NEXT WEEK...THE HEIGHT ANOMALIES WILL
WEAKEN...BUT THE TROF WILL REMAIN IN SE CANADA...RESULTING IN A
CONTINUED BLO NORMAL TEMP REGIME LIKELY PERSISTING FOR UPPER MI THRU
THE ENTIRE WEEK. AFTER THE SUN/MON PCPN...ANOTHER OPPORTUNITY OF
PCPN MAY OCCUR WED/THU IF THE NEXT SHORTWAVE LIFTING OUT OF THE MEAN
ROCKIES TROF MOVES FAR ENOUGH NE TO AFFECT THE UPPER LAKES. DRY
WEATHER SHOULD THEN ROUND OUT THE WEEK. LOOKING FARTHER AHEAD...
NAEFS OUTLOOKS IN THE 8-14DAY PERIOD (APR30-MAY7) INDICATE TEMPS
OVERALL CLOSE TO NORMAL FOR UPPER MI.
BEGINNING SAT NIGHT...-RA WILL DEVELOP/SPREAD INTO THE FCST AREA
WITHIN SHARPENING BAROCLINIC ZONE...LOW-MID LEVEL FGEN...UPPER
DIVERGENCE IN RRQ OF 120KT UPPER JET ACROSS NRN ONTARIO/SRN QUEBEC
AND STRENGTHENING ISENTROPIC ASCENT. WILL CARRY HIGHER CATEGORICAL
POPS INTO ROUGHLY THE FAR HALF IN THE 06Z-12Z PERIOD.
SUN/MON...PCPN GENERATION IN THE BAROCLINIC ZONE WILL CONTINUE TO BE
MAINTAINED BY LOW-MID LEVEL FGEN AND THE RIGHT ENTRANCE OF UPPER JET
ACROSS NRN ONTARIO/SRN QUEBEC. IN ADDITION...SHORTWAVE ENERGY
EJECTING FROM THE CNTRL/SRN ROCKIES INTO THE UPPER MISSISSIPPI
VALLEY...THOUGH WEAKENING...WILL FURTHER AID THE PCPN. WITH
PRECIPITABLE WATER OF 0.75 TO A LITTLE OVER 1 INCH...ROUGHLY 200-
250PCT OF NORMAL...POTENTIAL WILL BE THERE FOR MDT TO EVEN LOCALLY
HVY PCPN AMOUNTS. THIS FCST WILL SHOW TOTAL QPF SAT NIGHT TO MON
EVENING RANGING FROM AROUND ONE-THIRD OF AN INCH OVER THE NRN
KEWEENAW PENINSULA TO AROUND 2 INCHES ALONG THE WI/MI BORDER INTO
SCNTRL UPPER MI. MODELS HAVE NOT BE VERY CONSISTENT ON THERMAL
FIELDS AND POTENTIAL FOR ACCUMULATING SNOW. ABOUT ALL THAT CAN BE
SAID AT THIS POINT IS THAT THERE IS SOME POTENTIAL FOR ACCUMULATING
WET/HVY SNOW OVER PARTS OF UPPER MI...MAINLY THE HIGHER TERRAIN OF
THE W HALF LATE SUN NIGHT/MON MORNING.
PCPN SHOULD DIMINISH/END W TO E MON NIGHT AS WEAKENING SHORTWAVE
ENERGY LIFTING INTO THE UPPER MISSISSIPPI VALLEY MON SHIFTS E ACROSS
THE GREAT LAKES REGION. WILL IGNORE THE CANADIAN MODEL WHICH IS AN
OUTLIER IN BEING MUCH SLOWER TO SHIFT THE SHORTWAVE E...RESULTING IN
PCPN (RAIN/SNOW) LINGERING INTO TUE AFTN.
SKIES WILL CLEAR OUT FOR TUE. IN FACT...WITH GFS FCST SOUNDINGS
SHOWING A DEEP DRY AIR MASS...SHOULD SEE ABUNDANT SUNSHINE. DESPITE
THE SUN...IT WILL BE CHILLY UNDER 850MB TEMPS OF -2 TO -4C AT
MIDDAY. IN ADDITION...CHILL WILL BE AIDED BY A GRADIENT NE WIND TO
START THE DAY AND THEN MESO HIGH DEVELOPING OVER LAKE SUPERIOR IN
THE AFTN MAINTAINING LAKE COOLING.
WED/THU...ATTENTION SHIFTS TO THE NEXT CLUSTER OF SHORTWAVE ENERGY
THAT SETTLED INTO THE MEAN CNTRL/SRN ROCKIES TROF MON/TUE. MUCH WILL
DEPEND ON THE STRENGTH OF THE CONTINUED SE CANADA TROF WHICH WILL BE
EVOLVING INTO A MID LEVEL LOW. IF ITS INFLUENCE REMAINS STRONGER
FARTHER S...THE EJECTING ENERGY WILL BE SUPPRESSED S OF THE AREA...
KEEPING UPPER MI UNDER DRY WEATHER...SIMILAR TO RECENT GFS RUNS AND
THE 12Z CANADIAN. IF THE TROF/CLOSED LOW IN SE CANADA IS
WEAKER/FARTHER N...THE EJECTING ENERGY WILL LIFT FARTHER TO THE NE
AND BRING MORE RAIN INTO UPPER MI...SIMILAR TO RECENT ECMWF RUNS.
HOWEVER...THE 12Z ECMWF HAS STARTED TO BACK AWAY FROM ITS MORE
AGGRESSIVE NE PUSH OF PCPN. FOR NOW...FCST WILL UTILIZE A CONSENSUS
APPROACH WHICH RESULTS IN MOSTLY SCHC POPS WED/THU.
DRY WEATHER WILL THEN ROUND OUT THE WEEK AS HIGH PRES BUILDS SE INTO
THE GREAT LAKES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 109 PM EDT FRI APR 22 2016
MVFR CLOUD DECK AT KSAW WILL ERODE SHORTLY AFT 18Z AS DRIER AIR WORKS
IN FROM NORTH OF THE LAKE. HIGH PRES BUILDING INTO THE REGION WILL
MAINTAIN VFR CONDITIONS FOR ALL TAF SITES THROUGH THE REST OF THE
FCST PERIOD. THERE WILL BE SOME INCREASE IN MID-HIGH CLOUDS INTO
KCMX AND KSAW LATE SAT MORNING AS WARM AIR PUSHES NORTH OF A FRONTAL
BOUNDARY OVER THE NORTHERN PLAINS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 309 PM EDT FRI APR 22 2016
HIGH PRES WILL MOVE ACROSS LAKE SUPERIOR TONIGHT WITH WINDS
DIMINISHING TO 15 KNOTS OE LESS INTO SAT. AS THE HIGH EXITS TO THE
EASTERN SEABOARD AND LOW PRESSURE DEVELOPS OVER THE PLAINS ON
SUNDAY, NORTHEAST WINDS WILL INCREASE TO 20-30 KTS SUNDAY INTO
MONDAY. THE STRONGEST WINDS WILL BE OVER WESTERN LAKE SUPERIOR WHERE
WINDS MAY APPROACH GALES AT TIMES. WINDS DIMINISH TO LESS THAN 20
KTS MONDAY NIGHT INTO WEDNESDAY AS HIGH PRESSURE MOVES BACK ACROSS
THE REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...ROLFSON
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
404 PM EDT FRI APR 22 2016
.DISCUSSION...
DESPITE A TRUE SPLIT FLOW CONFIGURATION OVER THE HEMISPHERE...THE
WEATHER FOR SOUTHEASTERN MICHIGAN WILL CONTINUE TO BE INFLUENCED IN
THE NEAR TERM (NEXT 6-8 HRS) BY A DAMPENING UPPER LEVEL TROUGH. THIS
TROUGH FEATURE IS THE OLD TEXAS UPPER LEVEL PV ANOMALY BECOMING
REACCLIMATED TO THE CONSOLIDATED POLAR WESTERLY BELT. ALL OF
THIS...WITH A PARTIAL CONNECTION BETWEEN PV RESERVOIR HAS BEEN SLOW
TO OCCUR. THUS...THE SLUGGISH SOUTHWARD PROGRESSION TO THE
FRONT/DEWPOINT GRADIENT SEEN OVER MONROE COUNTY TODAY. HIGHER THAN
EXPECTED DEWPOINTS IN THE MID 50S HAS RESULTED IN SBCAPES OF AROUND
500 J/KG. LATEST HIRES EXPLICIT CAM OUTPUT SUPPORTS A CONTINUED
POTENTIAL FOR SOME SHOWERS THROUGH 21Z BEFORE ENDING. RAP BASED SPC
MESOANALYSIS SHOWS THAT THE POCKET OF INSTABILITY HAS ESSENTIALLY
BEEN PUSHED SOUTH OF THE CWA BORDER ALREADY...AND LATEST RADAR
TRENDS SUPPORT THIS IDEA.
MAIN FORECAST ITEM FOR TONIGHT CENTERS ON HOW FAST CLOUDS WILL CLEAR
OUT. VISIBLE IMAGERY SUGGESTS A STRONG DEPENDENCE/FOOTING WITHIN
THE BOUNDARY LAYER. GIVEN DRY AIR ADVECTION IN THE MODELS...AND THIS
DEPENDENCE ON BOUNDARY LAYER CLOUD...THE IDEA IS THAT CLOUDS WILL
CLEAR OUT RAPIDLY THIS EVENING. THE CLEAR SKIES...LIGHT WINDS WITH
BUILDING SURFACE HIGH PRESSURE SUGGESTS COLD TEMPERATURES TONIGHT.
WENT VERY AGGRESSIVE AND WORKED IN THE COLDEST OF THE GUIDANCE
WITH LOWS SATURDAY MORNING OF LOWER TO MIDDLE 30S.
STABLE SURFACE HIGH PRESSURE AND CLEAR SKIES SATURDAY WILL PROVIDE
EFOR WONDERFUL WEATHER TO SOUTHEASTERN MICHIGAN. FORECASTED MIXING
HEIGHTS ARE NOT PARTICULARLY LOW...BUT UPSTREAM AIRMASS NORTH OF
LAKE HURON IS VERY DRY AND STABLE...(DEWPOINTS IN THE 20S AND
TEENS). PATTERN RECOGNITION AND TIME OF YEAR SUGGESTS
OVERACHIEVEMENT POTENTIAL FROM THE INSOLATION...BUT REALLY WENT
COOLER FOR SATURDAY. THE OUTGOING FORECAST WILL READ MIDDLE TO UPPER
50S MANY AREAS...LOWER TO MIDDLE 40S ALONG THE SHORELINE. NO REAL
WIND TO SPEAK OF...BUT THE DRY AIRMASS/EVAPORATIVE COOLING POTENTIAL
WILL MAKE THINGS COOLER THAN THEY WOULD OTHERWISE SEEM.
SUNDAY...THE MAIN QUESTION IS EXACTLY WHERE A STRETCHING DEFORMATION
AXIS OR THE NARROW THINNING WEAKNESS IN THE GEOPOTENTIAL HEIGHT
FIELD WILL RESIDE. FORECAST TRENDS THE PAST 24 HOURS HAS BEEN
POINTING TO NORTH OF THE CWA. CONFIDENCE AT THIS TIME IS REASONABLY
THAT IT WILL BE NORTH ENOUGH TO KEEP PRECIPITATION CHANCES OUT OF
AREAS SOUTH OF M46. FOR THE TRI CITIES...THE POTENTIAL FOR SOME RAIN
WILL INCREASE BY THE LATE AFTERNOON...BUT CANNOT GO MORE THAN A
CHANCE POP. LATEST FORECAST DATA SUGGESTS THE SATURATION TRAPPED
WITHIN THIS DEFORMATION ZONE WILL UNDERGO A SIGNIFICANT ONSLAUGHT OF
DRY AIR ADVECTION FROM BOTH THE NORTH AND SOUTH ON SUNDAY. IN
FACT...SOME PROGS SUGGEST THAT A SIGNIFICANT CENTROID OF THE UPPER
LEVEL RIDGE WILL ROLL THROUGH SOUTHEASTERN MICHIGAN EARLY SUNDAY.
DUE TO THE SPLIT FLOW...THIS AIRMASS WILL NOT BE A PARTICULARLY
WARM/HOT ONE...BUT WONDERFUL WEATHER IS NOW EXPECTED FOR A GOOD
PORTION OF THE CWA WITH TEMPERATURES REACHING THE UPPER 60S TO LOW
70S.
SURFACE LOW PRESSURE WILL TRACK ACROSS LOWER MICHIGAN ON
MONDAY...ALLOWING RAIN SHOWERS TO PERSIST MUCH OF THE DAY AND INTO
MONDAY NIGHT. THE LOW WILL SLOWLY TRACK EASTWARD ON TUESDAY MORNING
AS HIGH PRESSURE BUILDS INTO THE REGION OUT OF CANADA. THIS HIGH
WILL ALLOW DRY CONDITIONS AND COOLER AIR TO FILTER INTO SOUTHEAST
MICHIGAN RESULTING IN HIGH TEMPS ON TUESDAY TO ONLY BE IN THE UPPER
50S. THIS HIGH WILL LAST THROUGH WEDNESDAY EVENING. THE NEXT MAJOR
SYSTEM ARRIVES WEDNESDAY NIGHT AND INTO THURSDAY AS A WARM FRONT
PUSHES NORTHWARD INTO SOUTHEAST MICHIGAN. THE CENTER OF THE LOW
PRESSURE SYSTEM WILL THEN TRACK OVER LOWER MICHIGAN ON THURSDAY AND
THURSDAY EVENING KEEPING CONDITIONS ACROSS SOUTHEAST MICHIGAN WET
AND CLOUDY.
&&
.MARINE...
NORTHERLY FLOW OVER LAKE HURON BETWEEN 15 TO 20 KNOTS THIS AFTERNOON
WILL GRADUALLY EASE JUST A BIT TO AROUND 15 KNOTS TONIGHT...AND
BECOMING NORTHEAST IN PROCESS. THIS WILL ALLOW WAVES TO DIMINISH
FROM THE 3 TO 6 FOOT RANGE TO MORE LIKE 2 TO 4 FEET OVER THE
SOUTHERN LAKE HURON BASIN. HIGH PRESSURE BUILDING INTO THE CENTRAL
GREAT LAKES TOMORROW WILL LEAD TO FAVORABLE BOATING
CONDITIONS...WITH LIGHT WINDS AND LOW WAVES...ALONG WITH FULL
SUNSHINE. A DEVELOPING FRONTAL BOUNDARY FOR THE SECOND HALF OF THE
WEEKEND WILL LEAD TO STRENGTHENING EASTERLY WINDS IN EXCESS OF 20
KNOTS OVER NORTHERN LAKE HURON...ALONG WITH SHOWERS...WHICH WILL
SPREAD ACROSS THE ENTIRE MARINE WATERS AS WE HEAD INTO MONDAY.
&&
.HYDROLOGY...
A STRENGTHENING FRONTAL BOUNDARY ON SUNDAY WILL BRING THE NEXT
CHANCE OF SHOWERS TO THE AREA...BUT BULK OF THE RAINFALL IS EXPECTED
TO OCCUR OVER NORTHERN LOWER MICHIGAN. A LOW RIDING ALONG THE FRONT
ON MONDAY WILL ALLOW FOR SHOWERS TO SPREAD ACROSS ALL OF SOUTHEAST
MICHIGAN...WITH THE POTENTIAL FOR RAINFALL TOTALS IN EXCESS OF HALF
AN INCH.
&&
.AVIATION...ISSUED 1256 PM EDT FRI APR 22 2016
LOW LEVEL MOISTURE GRADUALLY SCOURING OUT...WITH MVFR CEILINGS
LIKELY DISSIPATING LATE THIS EVENING...ALTHOUGH EXACT TIMING IS
UNCERTAIN...AS COLD NORTH/NORTHEAST FLOW OFF LAKE HURON COMPLICATES
THE FORECAST A BIT. HIGHER CONFIDENCE SKIES WILL BECOME CLEAR/MOSTLY
CLEAR AFTER MIDNIGHT...CONTINUING INTO THE DAY ON SATURDAY AS
SURFACE HIGH PRESSURE TAKES HOLD OF THE CENTRAL GREAT LAKES.
FOR DTW...SHOWERS TOWARD THE SOUTHERN MICHIGAN BORDER EARLY THIS
AFTERNOON EXPECTED TO REMAIN SOUTH OF THE TERMINAL.
//DTW THRESHOLD PROBABILITIES...
* HIGH FOR CEILINGS 5 KFT OR LESS THROUGH THE AFTERNOON...MEDIUM
THIS EVENING...THEN LOW OVERNIGHT.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LHZ421-
441>443.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
DISCUSSION...CB
MARINE.......SF
HYDROLOGY....SF
AVIATION.....SF
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
311 PM EDT FRI APR 22 2016
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 309 PM EDT FRI APR 22 2016
WV IMAGERY AND RAP ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW INTO
THE NRN LAKES ON THE PERIPHERY OF A DEEP LOW INTO NRN HUDSON BAY.
LOW LEVEL CAA WITH NRLY WINDS KEPT LOW CLOUDS ACROSS MUCH OF THE
FCST AREA INTO EARLY AFTERNOON...BUT NOW BUILDING HIGH PRES FM NW OF
LAKE SUPERIOR HAS ALLOWED FOR INFLUX OF DRIER AIR AND ERODING CLOUD
COVER MID-LATE THIS AFTERNOON. MAX TEMPS TODAY HAVE RANGED FM THE
MID TO UPPER 30S ALONG LAKE SUPERIOR TO AROUND 50F CLOSER TO THE WI
BORDER.
TONIGHT...ALTHOUGH WINDS WILL DIMINISH WITH THE SFC HIGH PRES RIDGE
SLIDING OVER THE AREA...WAA MID CLOUDS FROM SRN MANITOBA AND NRN MN
ARE EXPECTED TO SPREAD IN FM THE W OVERNIGHT DUE TO INCREASING 295-
300K ISENTROPIC ASCENT WHICH SHOULD KEEP TEMPS FROM DROPPING OFF TOO
FAR. TEMPS MAY STILL FALL INTO THE MID 20S CENTRAL AND EAST BEFORE
THE CLOUDS MOVE IN. OTHERWISE...EXPECT MIN READINGS IN THE LOWER 30S
WEST.
SAT...A WNW FLOW ALOFT WILL DOMINATE THE UPPER GREAT LAKES BETWEEN
AN UPR RIDGE AXIS IN THE PLAINS AND AN UPR TROUGH OVER ERN CANADA.
MODELS SHOW MID/HIGH CLDS CONTINUING TO SPREAD INTO UPPER MI WITH
WAA TO THE NE OF SHARPENING FNT FM THE DAKOTAS INTO MN.
HOWEVER...THE MAJORITY OF MODELS INDICATE LINGERING LLVL DRY AIR
ASSOCIATED WITH SLOWLY DEPARTING SFC HIGH PRES WL KEEP THE CWA DRY.
ONLY THE 12Z GFS SHOWS RAIN REACHING INTO THE NW CWA WHERE MODELS
INDICATE PROXIMITY TO STRONGER H7 FGEN ALONG AND NE OF SHARPENING
FRONTAL BOUNDARY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 351 AM EDT FRI APR 22 2016
LOOKS LIKE A CHILLY...ACTIVE WX PATTERN WL DOMINATE LATE THIS
WEEKEND INTO EARLY NEXT WEEK AS A VERY TIGHT BAROCLINIC ZN WL SETUP
ACRS THE UPR GREAT LKS UNDER THE CONFLUENCE ZN BTWN ARCTIC AIRSTREAM
IN CANADA AND AN ACTIVE POLAR BRANCH FLOW OVER THE NRN CONUS. SOME
MDT TO HEAVY PCPN IS LIKELY TO FALL OVER AT LEAST THE S HALF OF UPR
MI...WHICH WL BE CLOSER TO A STNRY FNT RUNNING W-E THRU THE UPR
MIDWEST. IF ENUF COLD AIR IN THE NNE FLOW BTWN BLDG HI PRES INTO NRN
ONTARIO AND THE LOWER PRES TO THE S ADVECTS INTO THE CWA AND THIS
AIR IS NOT EXCESSIVELY DRY...THERE COULD BE SOME ACCUMULATING WET SN
OVER MAINLY THE HIER TERRAIN OF NRN UPR MI ON SUN NGT INTO MON.
QUIETER BUT STILL RELATIVELY CHILLY WX WL BE THE RULE FOR MID WEEK.
SAT...UPR MI IS FCST TO BE DOMINATED BY WNW FLOW ALF BTWN UPR RDG
AXIS IN THE PLAINS AND UPR TROFFING IN ERN CANADA. ALTHOUGH MODELS
INDICATE A GOOD DEAL OF MID/HI CLDS RELATED TO WAA TO THE NE OF
SHARPENING FNT FM THE DAKOTAS INTO MN WL IMPACT THE CWA...SUSPECT
LINGERING LLVL DRY AIR ASSOCIATED WITH SLOWLY DEPARTING SFC HI PRES
WL KEEP THE CWA DRY. BEST CHC FOR SOME RAIN WL BE OVER THE NW CWA
CLOSER TO BAND OF STRONGER H7 FGEN TO THE NE OF SHARPENING FNT.
SAT NGT...MODELS IN FAIRLY GOOD AGREEMENT SHOWING MORE WIDESPREAD RA
DVLPG OVER THE CWA ESPECIALLY NEAR THE WI BORDER WITH SHARPENING
BAROCLINIC ZN/FGEN/INCRSG UPR DVGC IN RRQ OF 120KT H3 JET CORE
MOVING TO JUST S OF JAMES BAY BY 12Z SUN. WL CARRY THE HIER
CATEGORICAL POPS NEAR THE WI BORDER IN THE 06Z-12Z PERIOD.
SUN THRU MON...UPR MI IS FCST TO BE CLOSE TO SHARP BAROCLINIC ZN
UNDER CONFLUENCE ZN BTWN ARCTIC BRANCH NW FLOW DOMINATING QUEBEC AND
A WSW POLAR BRANCH FLOW OVER THE NRN CONUS. DESPITE THE UNFAVORABLE
LOOK OF THE CONFLUENT UPR FLOW WELL TO THE NE OF SHRTWV RIDING ENEWD
THRU THE NRN PLAINS WHICH WOULD TEND TO FAVOR DRY WX...MOST OF THE
MEDIUM RANGE MODELS GENERATE SOME MDT TO HEAVY PCPN OVER MAINLY THE
S HALF OF THE CWA. UPR DVGC IN RRQ OF 120KT H3 JET MAX JUST S OF
JAMES BAY AS WELL AS SHARP...PERSISTENT H85-7 FGEN N OF THE H85
WARM/STNRY FNT STRETCHING E ACRS WI FM LO IN THE NRN PLAINS AND
UNDER AXIS OF PWAT AOA AN INCH OVER THE SRN CWA LOOK TO BE THE
ENHANCEMENT FACTORS THAT WOULD OVERCOME THE UPR CONFLUENCE THAT WL
WEAKEN DISTURBANCES RIDING ENEWD TOWARD THE CWA AHEAD OF THE MAIN
SHRTWV TO THE SW. ALTHOUGH SOME OF THE COLDER MODELS` FCST SDNGS/
THERMAL FIELDS WITH H85 TEMPS AOB 0C INDICATE AT LEAST SOME OF THE
PCPN NEAR THE NRN EDGE OF THE BAND WL BE IN THE FORM OF SN...SHARP
GRADIENT IN SFC-H85 MSTR BTWN THE FNT AND CHILLY HI PRES BLDG INTO
NRN ONTARIO WL LIKELY BRING A RATHER SHARP NRN EDGE TO THE PCPN BAND
AND LIMIT THE COVERAGE OF SGNFT SN. BUT IF THE COLDER GUIDANCE IS
CORRECT AND THE LLVL DRYING IS NOT TOO AGGRESSIVE...NOT OUT OF THE
QUESTION THERE COULD BE SEVERAL INCHES OF WET...HEAVY SN OVER
PORTIONS OF THE NRN CWA MAINLY ON SUN NGT/MON MRNG AS STEADY LLVL NE
WINDS ADVECT COLDER AIR INTO THE LKS TO THE S OF THE ONTARIO HI PRES.
MON NGT THRU THU...AS THE HI PRES OVER NORTHERN ONTARIO BUILDS S
INTO THE UPR LKS UNDER CONFLUENT NW FLOW ALF BTWN UPR RDG AXIS
SHIFTING E FM THE PLAINS AND CLOSED UPR LO OVER QUEBEC...EXPECT
LINGERING PCPN TO END ON MON NGT...WITH THE HI PRES BRINGING DRY
WX/MOCLR SKIES ON TUE INTO WED. DEPENDING ON HOW QUICKLY THE QUEBEC
CLOSED LO WEAKENS AND WHETHER OR NOT THE UPR FLOW INTO THE GREAT LKS
TURNS MORE PROGRESSIVE...ANOTHER LO PRES MOVE ENE FM THE PLAINS
COULD BRING MORE PCPN TO THE AREA NEXT THU. BUT IF THE QUEBEC CLOSED
LO IS MORE RESILIENT...THAT NEXT PLAINS LO COULD BE SHUNTED TO THE
SW. EXPECT RELATIVELY CHILLY WX THRU THE EXTENDED PERIOD WITH SUB
ZERO H85 TEMPS DOMINATING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 109 PM EDT FRI APR 22 2016
MVFR CLOUD DECK AT KSAW WILL ERODE SHORTLY AFT 18Z AS DRIER AIR WORKS
IN FROM NORTH OF THE LAKE. HIGH PRES BUILDING INTO THE REGION WILL
MAINTAIN VFR CONDITIONS FOR ALL TAF SITES THROUGH THE REST OF THE
FCST PERIOD. THERE WILL BE SOME INCREASE IN MID-HIGH CLOUDS INTO
KCMX AND KSAW LATE SAT MORNING AS WARM AIR PUSHES NORTH OF A FRONTAL
BOUNDARY OVER THE NORTHERN PLAINS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 309 PM EDT FRI APR 22 2016
HIGH PRES WILL MOVE ACROSS LAKE SUPERIOR TONIGHT WITH WINDS
DIMINISHING TO 15 KNOTS OE LESS INTO SAT. AS THE HIGH EXITS TO THE
EASTERN SEABOARD AND LOW PRESSURE DEVELOPS OVER THE PLAINS ON
SUNDAY, NORTHEAST WINDS WILL INCREASE TO 20-30 KTS SUNDAY INTO
MONDAY. THE STRONGEST WINDS WILL BE OVER WESTERN LAKE SUPERIOR WHERE
WINDS MAY APPROACH GALES AT TIMES. WINDS DIMINISH TO LESS THAN 20
KTS MONDAY NIGHT INTO WEDNESDAY AS HIGH PRESSURE MOVES BACK ACROSS
THE REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KC
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
113 PM EDT FRI APR 22 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EDT FRI APR 22 2016
WV IMAGERY AND RAP ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW INTO
THE NRN LAKES ON THE PERIPHERY OF A DEEP LOW INTO NRN HUDSON BAY.
LOW LEVEL CAA WITH NRLY WINDS INCREASED OVERNIGHT AS THE PRES
GRADIENT TIGHTENED BETWEEN HIGH PRESSURE INTO NRN ONTARIO AND TROUGH
OVER THE LOWER LAKES. CONVERGENT AND UPSLOPE FLOW INTO N CNTRL UPPER
MI COMBINED WITH LINGERING LOW LEVEL MOISTURE SUPPORTED SOME DZ/FZDZ
THAT HAS MIXED WITH LIGHT SNOW.
TODAY...EXPECT THAT THE LIGHT SNOW WILL TRANSITION TO MAINLY DZ/FZDZ
EARLY THIS MORNING AS THE DEEPER MOISTURE DEPARTS...LEAVING THE
MOIST LAYER WARMER THAN -8C. SATELLITE AND MODEL 925-900 MB RH FCST
TRENDS SUGGEST THAT THE LIGHT PCPN SHOULD DIMINISH OR END AROUND
12Z-14Z BUT THAT THE CLOUDS MAY PERSIST...MOVING OUT BTWN 15Z-18Z AS
HIGH PRESSURE WITH LOW LEVEL DRYING BUILDS IN. OTHERWISE...SUNSHINE
WITH 850 MB TEMPS NEAR -2C DURING THE AFTERNOON WILL HELP BOOST
INLAND TEMPS TO AROUND 50. OTHERWISE...NRLY FLOW OFF OF LAKE SUPERIOR
WILL LIMIT HIGH TEMPS CLOSER TO 40.
TONIGHT...ALTHOUGH WINDS WILL DIMINISH WITH THE SFC RIDGE OVER THE
AREA...MID CLOUDS MOVING IN OVERNIGHT WITH 700-500 MB WAA WILL KEEP
TEMPS FROM DROPPING OFF TOO FAR. TEMPS MAY STILL FALL INTO THE MID
20S CENTRAL AND EAST BEFORE THE CLOUDS MOVE IN. OTHERWISE...EXPECT
MIN READINGS IN THE LOWER 30S WEST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 351 AM EDT FRI APR 22 2016
LOOKS LIKE A CHILLY...ACTIVE WX PATTERN WL DOMINATE LATE THIS
WEEKEND INTO EARLY NEXT WEEK AS A VERY TIGHT BAROCLINIC ZN WL SETUP
ACRS THE UPR GREAT LKS UNDER THE CONFLUENCE ZN BTWN ARCTIC AIRSTREAM
IN CANADA AND AN ACTIVE POLAR BRANCH FLOW OVER THE NRN CONUS. SOME
MDT TO HEAVY PCPN IS LIKELY TO FALL OVER AT LEAST THE S HALF OF UPR
MI...WHICH WL BE CLOSER TO A STNRY FNT RUNNING W-E THRU THE UPR
MIDWEST. IF ENUF COLD AIR IN THE NNE FLOW BTWN BLDG HI PRES INTO NRN
ONTARIO AND THE LOWER PRES TO THE S ADVECTS INTO THE CWA AND THIS
AIR IS NOT EXCESSIVELY DRY...THERE COULD BE SOME ACCUMULATING WET SN
OVER MAINLY THE HIER TERRAIN OF NRN UPR MI ON SUN NGT INTO MON.
QUIETER BUT STILL RELATIVELY CHILLY WX WL BE THE RULE FOR MID WEEK.
SAT...UPR MI IS FCST TO BE DOMINATED BY WNW FLOW ALF BTWN UPR RDG
AXIS IN THE PLAINS AND UPR TROFFING IN ERN CANADA. ALTHOUGH MODELS
INDICATE A GOOD DEAL OF MID/HI CLDS RELATED TO WAA TO THE NE OF
SHARPENING FNT FM THE DAKOTAS INTO MN WL IMPACT THE CWA...SUSPECT
LINGERING LLVL DRY AIR ASSOCIATED WITH SLOWLY DEPARTING SFC HI PRES
WL KEEP THE CWA DRY. BEST CHC FOR SOME RAIN WL BE OVER THE NW CWA
CLOSER TO BAND OF STRONGER H7 FGEN TO THE NE OF SHARPENING FNT.
SAT NGT...MODELS IN FAIRLY GOOD AGREEMENT SHOWING MORE WIDESPREAD RA
DVLPG OVER THE CWA ESPECIALLY NEAR THE WI BORDER WITH SHARPENING
BAROCLINIC ZN/FGEN/INCRSG UPR DVGC IN RRQ OF 120KT H3 JET CORE
MOVING TO JUST S OF JAMES BAY BY 12Z SUN. WL CARRY THE HIER
CATEGORICAL POPS NEAR THE WI BORDER IN THE 06Z-12Z PERIOD.
SUN THRU MON...UPR MI IS FCST TO BE CLOSE TO SHARP BAROCLINIC ZN
UNDER CONFLUENCE ZN BTWN ARCTIC BRANCH NW FLOW DOMINATING QUEBEC AND
A WSW POLAR BRANCH FLOW OVER THE NRN CONUS. DESPITE THE UNFAVORABLE
LOOK OF THE CONFLUENT UPR FLOW WELL TO THE NE OF SHRTWV RIDING ENEWD
THRU THE NRN PLAINS WHICH WOULD TEND TO FAVOR DRY WX...MOST OF THE
MEDIUM RANGE MODELS GENERATE SOME MDT TO HEAVY PCPN OVER MAINLY THE
S HALF OF THE CWA. UPR DVGC IN RRQ OF 120KT H3 JET MAX JUST S OF
JAMES BAY AS WELL AS SHARP...PERSISTENT H85-7 FGEN N OF THE H85
WARM/STNRY FNT STRETCHING E ACRS WI FM LO IN THE NRN PLAINS AND
UNDER AXIS OF PWAT AOA AN INCH OVER THE SRN CWA LOOK TO BE THE
ENHANCEMENT FACTORS THAT WOULD OVERCOME THE UPR CONFLUENCE THAT WL
WEAKEN DISTURBANCES RIDING ENEWD TOWARD THE CWA AHEAD OF THE MAIN
SHRTWV TO THE SW. ALTHOUGH SOME OF THE COLDER MODELS` FCST SDNGS/
THERMAL FIELDS WITH H85 TEMPS AOB 0C INDICATE AT LEAST SOME OF THE
PCPN NEAR THE NRN EDGE OF THE BAND WL BE IN THE FORM OF SN...SHARP
GRADIENT IN SFC-H85 MSTR BTWN THE FNT AND CHILLY HI PRES BLDG INTO
NRN ONTARIO WL LIKELY BRING A RATHER SHARP NRN EDGE TO THE PCPN BAND
AND LIMIT THE COVERAGE OF SGNFT SN. BUT IF THE COLDER GUIDANCE IS
CORRECT AND THE LLVL DRYING IS NOT TOO AGGRESSIVE...NOT OUT OF THE
QUESTION THERE COULD BE SEVERAL INCHES OF WET...HEAVY SN OVER
PORTIONS OF THE NRN CWA MAINLY ON SUN NGT/MON MRNG AS STEADY LLVL NE
WINDS ADVECT COLDER AIR INTO THE LKS TO THE S OF THE ONTARIO HI PRES.
MON NGT THRU THU...AS THE HI PRES OVER NORTHERN ONTARIO BUILDS S
INTO THE UPR LKS UNDER CONFLUENT NW FLOW ALF BTWN UPR RDG AXIS
SHIFTING E FM THE PLAINS AND CLOSED UPR LO OVER QUEBEC...EXPECT
LINGERING PCPN TO END ON MON NGT...WITH THE HI PRES BRINGING DRY
WX/MOCLR SKIES ON TUE INTO WED. DEPENDING ON HOW QUICKLY THE QUEBEC
CLOSED LO WEAKENS AND WHETHER OR NOT THE UPR FLOW INTO THE GREAT LKS
TURNS MORE PROGRESSIVE...ANOTHER LO PRES MOVE ENE FM THE PLAINS
COULD BRING MORE PCPN TO THE AREA NEXT THU. BUT IF THE QUEBEC CLOSED
LO IS MORE RESILIENT...THAT NEXT PLAINS LO COULD BE SHUNTED TO THE
SW. EXPECT RELATIVELY CHILLY WX THRU THE EXTENDED PERIOD WITH SUB
ZERO H85 TEMPS DOMINATING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 109 PM EDT FRI APR 22 2016
MVFR CLOUD DECK AT KSAW WILL ERODE SHORTLY AFT 18Z AS DRIER AIR WORKS
IN FROM NORTH OF THE LAKE. HIGH PRES BUILDING INTO THE REGION WILL
MAINTAIN VFR CONDITIONS FOR ALL TAF SITES THROUGH THE REST OF THE
FCST PERIOD. THERE WILL BE SOME INCREASE IN MID-HIGH CLOUDS INTO
KCMX AND KSAW LATE SAT MORNING AS WARM AIR PUSHES NORTH OF A FRONTAL
BOUNDARY OVER THE NORTHERN PLAINS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 457 AM EDT FRI APR 22 2016
NORTHERLY WINDS 15-25 KNOTS EARLY THIS MORNING ARE EXPECTED TO
DIMINISH TO 20 KTS OR LESS FRIDAY AFTERNOON THROUGH MOST OF SATURDAY
NIGHT AS A HIGH PRESSURE RIDGE CROSSES LAKE SUPERIOR. AS THE HIGH
EXITS TO THE EASTERN SEABOARD AND LOW PRESSURE DEVELOPS OVER THE
PLAINS ON SUNDAY, NORTHEAST WINDS WILL INCREASE TO 20-30 KTS SUNDAY
INTO MONDAY. THE STRONGEST WINDS WILL BE OVER WESTERN LAKE SUPERIOR
WHERE WINDS MAY APPROACH GALES AT TIMES. WINDS DIMINISH TO LESS THAN
20 KTS MONDAY NIGHT INTO TUESDAY AS HIGH PRESSURE MOVES BACK ACROSS
THE REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...VOSS
MARINE...JLB
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
305 PM PDT FRI APR 22 2016
.SYNOPSIS...A SERIES OF PACIFIC STORM SYSTEMS WILL BRING COOLER
TEMPERATURES, WINDY PERIODS, AND CHANCES OF PRECIPITATION TO
PORTIONS OF THE REGION THROUGH EARLY NEXT WEEK. THE
BEST CHANCES OF PRECIPITATION APPEAR TO BE IN THE SIERRA AND
SOUTHERN GREAT BASIN TONIGHT THEN AGAIN ON MONDAY.
&&
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT.
THE VIGOROUS TROUGH DIVING OVER NORTHERN AND CENTRAL CALIFORNIA
WILL CONTINUE TO PRODUCE WIDESPREAD SOUTH-SOUTHWEST WINDS GUSTING
OVER 40 MPH ACROSS MUCH OF THE FORECAST AREA THIS EVENING. THE TROUGH
AXIS IS FORECAST TO QUICKLY TRAVERSE SOUTHERN NEVADA BETWEEN 06Z AND
12Z SATURDAY MORNING AND WE WILL LIKELY SEE SOME OF THE STRONGEST
GUSTS ACROSS SOUTHERN NEVADA AND THE MOJAVE DESERT REGION BETWEEN
05Z AND 09Z. SEVERAL SENSORS ACROSS THE NEVADA NATIONAL SECURITY SITE
IN NORTHERN NYE COUNTY RECORDED GUSTS OVER 60 MPH THIS AFTERNOON AND
A HIGH WIND WARNING WAS ISSUED FOR CENTRAL/SOUTHERN NYE AND WESTERN
LINCOLN COUNTIES AS SIMILAR GUSTS WILL CONTINUE INTO EARLY THIS EVENING.
THE LATEST HIGH RES MODELS INDICATE A FAIRLY QUICK DROP IN WIND SPEEDS
AFTER 04Z ACROSS INYO COUNTY AND SOUTH CENTRAL NEVADA THEN DECREASING
AFTER 10Z FOR THE SPRING MOUNTAINS AND MUCH OF THE MOJAVE DESERT ZONES.
NUMEROUS SHOWERS WILL OCCUR ACROSS NORTHERN INYO AND ESMERALDA COUNTIES
THIS EVENING AND POPS WERE INCREASED CONSIDERABLE FOR THOSE ZONES.
SATURDAY SHOULD BE A FAIRLY PLEASANT DAY WITH NORTHWEST WINDS GENERALLY
LESS THAN 15 MPH AND TEMPERATURES RUNNING ABOUT 10-12 DEGREES COOLER
ACROSS SOUTHERN NEVADA AND SURROUNDING AREAS. ATTENTION THEN TURNS TO
THE NEXT PACIFIC SYSTEM WHICH WILL BE NEAR THE PACIFIC NORTHWEST SUNDAY
MORNING THEN DIVING TOWARD SOUTHERN NEVADA SUNDAY NIGHT. THIS WILL BRING
INCREASING SOUTH-SOUTHWEST WINDS AHEAD OF IT SUNDAY AFTERNOON AND EVENING
AND THE POTENTIAL FOR SHOWERS WILL SPREAD DOWN ACROSS INYO COUNTY AND
SOUTH CENTRAL NEVADA INTO THE SPRING MOUNTAINS AND SHEEP RANGE SUNDAY
NIGHT.
.LONG TERM...MONDAY THROUGH THURSDAY.
ACTIVE PATTERN CONTINUES WITH TWO MORE STORMS IN THE LONG TERM
PERIOD. THE FIRST WILL BE AFFECTING OUR AREA MONDAY. MODELS ARE
CURRENTLY IN GOOD AGREEMENT...AND IF THE SOLUTIONS PAN OUT...PRECIP
CHANCES WOULD BE ROUGHLY FROM LAS VEGAS NORTH WITH STRONG WESTERLY
WINDS FROM LAS VEGAS SOUTH. JUDGING FROM THE CURRENT MODELS...WIND
ADVISORIES WOULD LIKELY BE NEEDED AGAIN FOR MUCH OF THE MOJAVE
DESERT...BUT WILL CONTINUE TO MONITOR FOR ANY NORTHWARD OR SOUTHWARD
SHIFTS IN THE STORM TRACK. SINCE THE STORM IS TRACKING EASTWARD
RATHER THAN SOUTHWARD...POST FRONTAL NORTHERLY WINDS TUESDAY SHOULD
NOT BE SIGNIFICANT. BY WEDNESDAY THE NEXT STORM APPROACHES THE WEST
COAST WITH SOUTHWEST WINDS INCREASING AGAIN.
THERE IS MORE MODEL SPREAD WITH THE TRACK AND STRENGTH OF THIS
STORM...AS IS TYPICAL 6-7 DAYS OUT. A MODEL CONSENSUS WOULD SUGGEST
A SIMILAR OUTCOME TO THE MONDAY STORM...EXCEPT PERHAPS SLIGHTLY LESS
STRONG WIND. PLENTY OF TIME TO WATCH THIS...WITH THE MAIN MESSAGE AT
THIS TIME BEING TO PREPARE FOR WINDY AND RAPIDLY CHANGING WEATHER
FOR MUCH OF NEXT WEEK. SPEAKING OF RAPIDLY CHANGING...TEMPERATURES
WILL CRASH DOWN TO ABOUT TEN DEGREES BELOW NORMAL AREAWIDE ON MONDAY
AND TUESDAY...RISE A BIT WEDNESDAY...THEN GET KNOCKED DOWN AGAIN ON
THURSDAY AS THE NEXT STORM ARRIVES.
&&
.AVIATION...FOR MCCARRAN...WINDY EVENING IN STORE FOR THE TERMINAL
AS A STORM SYSTEM MOVES THROUGH THE AREA TONIGHT AND TOMORROW. SOUTH
WINDS HAVE INCREASED THIS AFTERNOON AND SPEEDS/GUSTS SHOULD CONTINUE
TO CLIMB GRADUALLY THROUGH THIS EVENING AS DIRECTIONS VERY SLOWLY TO
A MORE SOUTHWESTERLY DIRECTION OVERNIGHT. MAX SPEEDS EXPECTED TO BE
20-30 KTS WITH GUSTS UP TO 40 KTS BETWEEN ABOUT 03Z AND 09Z. WINDS
WILL CONTINUE TO VEER AS A COLD FRONT APPROACHES THE VALLEY LATE
TONIGHT...BUT SPEEDS WILL DECREASE RAPIDLY AFTER 09Z. WINDS WILL
SWITCH TO N OR NW IN THE 12Z TO 16Z PERIOD. ALTHOUGH WINDS MAY PICK
UP DURING AND JUST AFTER FRONTAL PASSAGE...MOST GUIDANCE SUGGESTS
SPEEDS 5-15 KTS WITH AN OCCASIONAL GUST TO 20 KTS TOMORROW WITH THE
STRONGEST WINDS IN THE MORNING. FEW-SCT MID AND HIGH CLOUDS EXPECTED
THROUGH THE PERIOD. MECHANICAL TURBULENCE CAN BE EXPECTED THROUGH
TONIGHT ESPECIALLY DOWNSTREAM OF THE SPRING MOUNTAINS.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SOUTH/SOUTHWEST WINDS HAVE INCREASED ACROSS THE AREA
THIS AFTERNOON WITH SPEEDS GENERALLY 15-30 KTS WITH GUSTS UP TO 40
KTS. WINDS SHOULD CONTINUE TO INCREASE SLOWLY THROUGH THE EVENING
HOURS...ESPECIALLY IN THE SOUTHERN GREAT BASIN AND INYO COUNTY.
SPOTTY AREAS OF BLOWING DUST HAVE BEEN REPORTED THIS AFTERNOON...AND
CAN BE EXPECTED THROUGH THE EVENING HOURS. SPEEDS SHOULD BEGIN TO
DECREASE RAPIDLY AFTER 09Z. MOUNTAIN WAVE ACTIVITY IS POSSIBLE
DOWNSTREAM OF THE SIERRA, WHITES, AND SPRING MOUNTAINS, AND
MECHANICAL TURBULENCE IS LIKELY THROUGH THE OVERNIGHT HOURS. A COLD
FRONT WILL SWEEP ACROSS THE AREA OVERNIGHT AND TOMORROW MORNING,
SWITCHING WINDS TO NORTH/NORTHWEST. DURING AND JUST AFTER FRONTAL
PASSAGE, WINDS MAY PICK UP (10-20 KTS), BUT OVERALL SPEEDS WILL BE
CONSIDERABLY LOWER TOMORROW THAN THOSE OBSERVED TODAY. BRIEF SHOT OF
LIGHT PRECIPITATION IS EXPECTED IN THE SIERRA AND WHITE MOUNTAINS
THIS EVENING/OVERNIGHT WITH BKN-OVC 050-120 CIGS AND SOME MOUNTAIN
OBSCURATIONS POSSIBLE...OTHERWISE FEW-SCT MID AND HIGH CLOUDS ARE
ANTICIPATED FOR MOST OF THE REGION THROUGH THE PERIOD.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS SHOULD REPORT ANY
SIGNIFICANT WEATHER ACCORDING TO STANDARD OPERATING PROCEDURES.
$$
SHORT TERM...ADAIR
LONG TERM.... MORGAN
AVIATION....SHAFER
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
[top]
Area Forecast Discussion
National Weather Service Reno NV
303 PM PDT FRI APR 22 2016
.SYNOPSIS...
A strong Pacific storm will continue to move through the Sierra
and Western Nevada tonight. Rain and heavy mountain snow are
expected this evening near and south of I-80. A break is expected
Saturday before more showers are expected Sunday into Monday with
another system. Unsettled weather will continue through next week
with below average temperatures.
&&
.SHORT TERM...
A strong spring storm continues to move through. Heavy snow is
falling in the Sierra with rates approaching 3"/hr. It is best to
avoid travel in the Sierra for the next few hours if possible.
Heavy convective snowfall continues in the Sierra with the bands
extending from Westwood south into Bridgeport. Heavy snow is
falling above 6000 feet, with the snow level locally down to 4500
feet in the heaviest bands. Latest satellite/radar trends support
the HRRR in keeping the heaviest rain/snow going thru 03Z near and
south of I-80. After there will be a rapid reduction in showers as
the upper forcing moves east and the airmass stabilizes.
Until then, another 6+ inches of snow is possible above 7000 feet
with another 2-4" down to 5500-6000 feet. Rainfall into Western NV
will be heaviest in the Sierra front where an additional 1/4" of
rain is possible. It may mix with snow at times in the foothills
while lighter amounts are expected toward the highway 95 corridor.
Winds are much weaker along the Sierra Front with the precip
falling, but strong gusts continue east of a Bridgeport to
Lovelock line. Will cancel the advisory for Reno-Carson-Minden,
but leave the remainder as the winds continue there.
Behind this storm, a break is expected Saturday with continued
cool temps, but lighter winds and dry conditions. Another upper
low is expected Sunday afternoon into Monday. Showers are expected
Sunday afternoon with enough instability for a few thunderstorms
as well. The core of the low will move overhead Monday morning
with much colder air. Snow levels will fall to near the valley
floors. While this storm will have some moisture with it, the best
forcing is expected to remain over Eastern NV so we are not
expecting another big precip event. However, there remains a
threat (low at this time) of some light snowfall during the Monday
morning commute along the I-80 and highway 50 corridors. Wallmann
.LONG TERM...Monday Night through Friday...
Unsettled weather pattern is expected to continue through next
week as late season storm systems line up to move into the West
Coast. Wednesday-Friday could be a rather wet period for much of
the region with potential for additional snow in higher
elevations.
For Monday night, the first upper low is likely to be on its way
out with lingering rain and snow showers diminishing. Tuesday
still looks like the least active weather day, although a few
showers remain possible as residual moisture will remain in place.
Even though temperatures are expected to increase about 10-15
degrees from Monday, highs in the lower 60s and around 50 degrees
near the Sierra will still be a few degrees below average for late
April.
For next Wednesday-Friday, medium range guidance continues to
indicate a potent low pressure tracking southward along the
California coast, then swing inland across the southwest US (or
possibly farther north into eastern NV). Despite this southerly
track, a broad area of upper divergence and instability is
projected to set up over the Sierra and western NV, along with a
decent tap of Pacific moisture. A few thunderstorms are also
possible each afternoon, although the better instability looks to
be trending north of I-80 by next Friday. Current projections
favor the best overall rain and snow chances Wednesday night and
higher thunderstorm potential on Thursday, but this could vary
depending on the eventual storm track. Widespread cloud cover will
keep daytime temps a few degrees below average each day, with
nighttime temps slightly above average. Early snow level
projections generally range from 6000-7000 feet in the Sierra,
although these snow levels could occasionally drop several hundred
feet during convection or heavier precip bands. MJD
&&
.AVIATION...
The most significant weather effects on aviation will continue
through this evening with IFR/LIFR cigs/vsby in snow near the
Sierra including KTVL/KTRK/KMMH, and a few inches of snow
accumulating on pavement. For lower elevations including KRNO-
KCXP, rain will produce MVFR cigs/vsby with mountain obscurations,
IFR at times during heavier rain bands. The strongest winds have
ended at KRNO-KCXP but some gusts to 35 KT remain possible. KMMH
may receive stronger gusts above 40 KT until 03z.
Later tonight, if cloud cover breaks up sufficiently, areas of
FZFG would develop across many Sierra valleys around Tahoe and
northeast CA, including KTRK. For Saturday, generally VFR
conditions are expected with lighter winds. MJD
&&
.REV Watches/Warnings/Advisories...
NV...Winter Weather Advisory until 11 PM PDT this evening NVZ002.
Wind Advisory until 8 PM PDT this evening NVZ001-004.
CA...Winter Weather Advisory until 5 PM PDT this afternoon above 5500
feet in CAZ071.
Wind Advisory until 8 PM PDT this evening CAZ073.
Winter Weather Advisory until 11 PM PDT this evening CAZ072.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1152 AM MDT FRI APR 22 2016
.AVIATION...
18Z TAF CYCLE
SOUTHERLY WINDS TODAY WILL DELIVER AN INFLUX OF MOISTURE FOR
-SHRA/TSRA AFT 22Z BTWN THE CONT DVD AND THE CENTRAL MT CHAIN.
GREATEST CHANCE FOR GUSTY OUTFLOW WINDS AND MEASURABLE PRECIP
WILL OCCUR AROUND KAEG...KABQ...AND KSAF BTWN 00Z AND 06Z. NO
IMPACTS BELOW VFR ARE EXPECTED. ACTIVITY MAY ALSO SLIDE OFF THE
CENTRAL MT CHAIN TO KLVS AND KROW DURING THE EVENING/OVERNIGHT
PERIOD BUT CONFIDENCE NOT AS HIGH THERE. DRIER SW FLOW WILL MOVE
IN SATURDAY WITH A FEW REMNANT -SHRA POSSIBLE OVER THE NORTHERN
HIGH TERRAIN AND THE NE PLAINS.
GUYER
&&
.PREV DISCUSSION...333 AM MDT FRI APR 22 2016...
.SYNOPSIS...
MODEST MOISTURE CONTINUES TO WORK ITS WAY INTO CENTRAL NEW MEXICO
FROM THE SOUTHEAST AS A COUPLE OF LOW PRESSURE SYSTEMS CROSS THE
WEST COAST. THESE SYSTEMS WILL SKIRT AROUND NEW MEXICO TO THE
NORTH AND SOUTH...BUT THE MOISTURE IN PLACE WILL HELP SPARK
SCATTERED TO ISOLATED SHOWERS AND THUNDERSTORMS MAINLY OVER
CENTRAL AREAS THIS AFTERNOON AND EVENING...THEN ALONG AND TO A
LESSER EXTENT EAST OF THE CENTRAL MOUNTAIN CHAIN ON SATURDAY. THE
JET STREAM WILL MOVE OVER THE COLORADO AND NEW MEXICO BORDER ON
SATURDAY WITH SURFACE WIND GUSTS PROBABLY REACHING 50 MPH OVER A
GOOD PORTION OF NORTHERN NEW MEXICO IN THE AFTERNOON. FIRE WEATHER
CONCERNS WILL RAMP UP WEST OF THE CENTRAL MOUNTAIN CHAIN
SATURDAY...THEN CONTINUE TO PLAGUE PORTIONS OF NORTHERN AND
CENTRAL NEW MEXICO THROUGH TUESDAY AS DRIER AIR MOVES IN FROM THE
WEST AND BREEZY TO WINDY CONDITIONS RETURN DAILY.
&&
.DISCUSSION...
SOME STORMS WILL PRODUCE LITTLE OR NO RAIN WEST OF THE
CONTINENTAL DIVIDE TODAY...THEN AT LOWER ELEVATIONS BETWEEN THE
CENTRAL MOUNTAIN CHAIN AND CONTINENTAL DIVIDE ON SATURDAY.
MEANWHILE...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS
SATURDAY AFTERNOON AND EVENING IN UNION COUNTY/FAR NE NM.
A PACIFIC COLD FRONT WILL CROSS FROM THE WEST SATURDAY AND
SATURDAY NIGHT USHERING COOLER TEMPERATURES AND DRY AIR FOR
SUNDAY. READINGS WILL VARY AROUND NORMAL MOST PLACES...EXCEPT ON
THE FAR EASTERN PLAINS WHERE READINGS 4 TO 10 DEGREES ABOVE NORMAL
SHOULD PERSIST. BREEZY TO WINDY CONDITIONS ARE EXPECTED TO RETURN
IN THE VICINITY OF THE I-40 CORRIDOR OF EASTERN NM SUNDAY AFTERNOON
WITH WESTERLY DOWNSLOPE FLOW.
ANOTHER UPPER LEVEL LOW PRESSURE SYSTEM WILL DIG INTO THE GREAT
BASIN ON MONDAY...THEN PASS NORTH OF NEW MEXICO ON TUESDAY
STEERING THE JET STREAM SQUARELY OVER THE FORECAST AREA. THIS WILL
KEEP BREEZY TO WINDY CONDITIONS IN THE FORECAST ACROSS WESTERN
AREAS MONDAY AND AREAWIDE TUESDAY. IT WILL CAUSE FIRE WEATHER
CONCERNS TO PERSIST.
SHORT WAVE RIDGING WILL CAUSE WINDS TO SETTLE DOWN WEDNESDAY...BUT
SW FLOW LOOKS TO STRENGTHEN AGAIN DURING THE LATTER HALF OF THE
WEEK AS YET ANOTHER UPPER LEVEL LOW PRESSURE SYSTEM DIGS INTO THE
GREAT BASIN AND APPROACHES NM FROM THE W OR NW.
44
&&
.FIRE WEATHER...
CRITICAL CONDITIONS WILL BE AT LEAST SPOTTY SATURDAY THROUGH MONDAY
WITH MORE WIDESPREAD CRITICAL CONDITIONS POSSIBLE NEXT TUESDAY. VENT
RATES WILL BE GOOD TO EXCELLENT TODAY THROUGH NEXT WEDNESDAY.
THE LATEST MODELS QUITE CONSISTENT WITH PREVIOUS VERSIONS IN THE
SHORTER TERM. THE UPPER RIDGE WILL BE MOVING OVER NEW MEXICO TODAY
AND THEN TO THE EAST OF THE STATE SATURDAY AS AN UPPER LOW TRACKS
INTO THE GREAT BASIN AND THROUGH THE CENTRAL ROCKIES. WINDS ALOFT
WILL TRANSITION TO SOUTHWEST LATER TODAY AND TONIGHT...AND WILL
STRENGTHEN WITH TIME. LOW LEVEL MOISTURE APPEARS TO BE MIGRATING INTO
SOUTH CENTRAL NM AT THIS TIME...AND A SUSTAINED SOUTHEAST TO SOUTH
FLOW REMAINS FORECAST...WHICH WOULD BRING HIGHER DEW POINTS UP THE
RGV AND TOWARDS THE CONTDVD...AS THE GFS HAS BEEN INDICATING FOR
SEVERAL DAYS. RUC AND HRRR NOW JUMPING ONBOARD BREAKING OUT CONVECTION
ALONG THE CONTDVD AND CENTRAL MT CHAIN BY MIDAFTERNOON. WITH THE
POOR RH RECOVERIES ALONG/WEST OF THE CONTDVD AT THIS TIME...CAN/T HELP BUT
THINK THERE MAY BE SOME HIGH BASED VIRGA SHOWERS/ISOLD DRY LIGHTNING
OVER THIS AREA LATER TODAY...GIVEN THE INSTABILITY FORECAST BY THE NAM12.
CONVECTION THIS EVENING MAY RESULT IN SOME WETTING PRECIPITATION BETWEEN THE
CONTDVD AND EAST SLOPES OF THE CENTRAL MT CHAIN.
SATURDAY STILL LOOKS TO SEE WIND GUSTS TO AROUND 45 OR 50 MPH AS THE
WESTERLY WINDS SHOVE THE LOW LEVEL MOISTURE FROM WEST TO EAST OVER
THE STATE. MIN RH VALUES FALL BELOW 15 PERCENT FOR PORTIONS OF THE
MIDDLE RGV AND WEST. DECIDED TO GO AHEAD WITH A FIRE WEATHER WATCH
FOR AREAS BELOW SNOWPACK FOR THE NORTHWEST/WEST CENTRAL AND MIDDLE RGV
ALTHOUGH MAINLY FOR BERNALILLO AND VALENCIA COUNTIES IF THE GRIDS
ARE CLOSE. NOT SURE OF THE STATE OF GREENUP AT THIS TIME...BUT RECENT
COOLER WEATHER MAY HAVE RETARDED IT. HIGHS WILL BE ABOVE AVERAGE...BUT
NOT OVERLY SO...IN THE RANGE OF 5 TO 10 DEGREES.
CONVECTION WILL BE FOCUSED OVER THE CENTRAL AND EAST SATURDAY/SATURDAY
NIGHT BUT SUNDAY LOOKS TO BE DRY. THERE MAY BE A FEW SHOWERS OR STORMS
ON THE DRIER SIDE FROM THE CENTRAL MT CHAIN WWD AS THE MOISTURE BECOMES
MORE SHALLOW ON SATURDAY. RIDGETOP WINDS MAY PERSIST SATURDAY NIGHT BEFORE
RELENTING SOMEWHAT SUNDAY UNDER ZONAL FLOW...BUT NOT ENOUGH TO
ELIMINATE THE POTENTIAL FOR CRITICAL CONDITIONS IN THE EAST CENTRAL
SUNDAY AFTERNOON. RH RECOVERIES SATURDAY AND SUNDAY NIGHT WILL BE
FAIR TO POOR FOR MANY LOCALES.
MONDAY THROUGH TUESDAY WILL SEE INCREASING WINDS AS ANOTHER SYSTEM
SWINGS THROUGH THE CENTRAL ROCKIES. POOR RH RECOVERIES LOOK TO BE
WIDESPREAD MONDAY NIGHT. HIGHS WILL FALL TO AROUND 5 TO 10 DEGREES
BELOW AVERAGE WEST AND CENTRAL AND TO NEAR AVERAGE EAST BY TUESDAY...
TO HELP MODERATE THE COMBO OF WIND AND SUB 15 PERCENT RH FROM THE
MIDDLE RGV TO THE EAST CENTRAL AND NORTHEAST PLAINS TUESDAY AFTERNOON...
WHERE CRITICAL CONDITIONS LOOK TO BE WIDESPREAD. ANY WETTING PRECIPITATION
WILL BE CONFINED TO THE HIGHER TERRAIN OF THE NORTHWEST AND NORTH CENTRAL
MONDAY THROUGH TUESDAY. GUSTY WEST WINDS MAY CONTINUE TUESDAY NIGHT BEFORE
SLACKING OFF. ANOTHER SYSTEM LINED UP FOR THE END OF NEXT WEEK BUT GFS
IS DRIER AND WINDIER...THE ECMWF IS WETTER.
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING
FOR THE FOLLOWING ZONES... NMZ101-105-106.
&&
$$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1240 PM EDT FRI APR 22 2016
.SYNOPSIS...A COLD FRONT WILL MOVE SLOWLY EAST ACROSS CENTRAL NC
LATE TONIGHT THROUGH EARLY SATURDAY MORNING. HIGH PRESSURE WILL
BUILD INTO THE REGION BEHIND THE FRONT SATURDAY AFTERNOON
THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM FRIDAY...
MAIN ADJUSTMENTS THIS MORNING WERE TO RAISE POPS WHERE STEADY
SHOWERS ARE ONGOING OR IMMINENT. INCREASINGLY WARM AND MOIST SSW LOW
LEVEL FLOW IS PULLING ABOVE NORMAL PW INTO THE AREA (NEAR 1.5")...
AND DEEPENING FORCING FOR ASCENT (INCLUDING MODEST MID LEVEL
HEIGHT FALLS AND IMPROVING UPPER DIVERGENCE) AND MINOR INSTABILITY
WITH MIXING/HEATING WILL LEAD TO FURTHER DEVELOPMENT OF SHOWERS AND
ISOLATED STORMS THROUGH THE AFTERNOON... YIELDING SEVERAL HOURS OF
CATEGORICAL POPS AREAWIDE. WHILE QPF FROM THE CAMS STILL APPEARS
OVERDONE IN SPOTS... THE OVERALL TOTAL QPF APPEARS TO BE TRENDING A
BIT HIGHER THAN WAS DENOTED YESTERDAY... WITH OBSERVATIONS
INDICATING A QUARTER TO HALF INCH FOR MOST AREAS THROUGH TONIGHT
WITH LOCALLY HIGHER AMOUNTS. THE RISK OF THUNDER APPEARS MARGINAL
WITH RAP SURFACE CAPE PEAKING AT 200-500 J/KG NW TO SE... ALTHOUGH
DEEP LAYER SHEAR SHOULD BE IMPROVING IN THE EAST. WILL LEAVE IN A
MENTION OF ISOLATED THUNDER AREAWIDE... AND MONITOR CLOSELY FOR ANY
AREAS OF ENHANCED HEATING THAT MIGHT PUSH CAPE UP. OBSERVED TRENDS
AND HIGH RES GUIDANCE SHOW A SMALL TEMP CLIMB TODAY GIVEN THE CLOUDS
AND PRECIP... SO EXPECT HIGHS OF 69-78 NW TO SE. -GIH
EARLIER DISCUSSION FROM 335 AM: WATER VAPOR IMAGERY AT 07Z DEPICTS
WELL DEFINED S/W LIFTING E-NE OUT OF THE LOWER MS VALLEY. NEAR TERM
MODEL GUIDANCE HAS DECENT HANDLE ON THIS FEATURE...LIFTING IT ACROSS
OUR REGION LATER TODAY. THE APPROACH OF THIS SYSTEM INTERACTING WITH
AVAILABLE MOISTURE WILL TRIGGER SCATTERED-NUMEROUS
SHOWERS...INITIALLY OVER THE WESTERN PIEDMONT AFTER 9-10AM...AND
ACROSS THE BULK OF CENTRAL THIS AFTERNOON. MODEL GUIDANCE HAS
TRENDED DEEPER WITH THE LIFT THROUGH THE COLUMN...SUPPORTIVE OF
HIGHER RAINFALL AMOUNTS THAN SUGGESTED A COUPLE OF DAYS AGO. NOT
READY TO CLIMB ONBOARD THE GUIDANCE FROM WPC...SUGGESTING RAINFALL
TOTALS IN THE RDU AREA 1-1.33 INCHES TODAY AND TONIGHT. HAVE LEANED
TOWARD AMOUNTS GENERALLY IN THE HALF TO THREE-QUARTERS OF AN INCH
WITH POCKETS AROUND AN INCH. RAIN WILL BE WELCOMED FOR MOST FOLKS AS
MEASURABLE RAINFALL HAS NOT BEEN OBSERVED IN 8-9 DAYS. THUNDER
THREAT STILL APPEARS CONFINED TO AREAS ALONG AND EAST OF HIGHWAY 1
DURING PEAK HEATING THOUGH LOW LEVEL INSTABILITY MEAGER WITH SBCAPE
NO WORSE THAN A 1000-1200 J/KG AND MLCAPE AT OR BELOW 300 J/KG.0-6KM
BULK SHEAR INCREASES THIS AFTERNOON TO AROUND 35 KTS...SO EXPECT THE
SMATTERING OF SHOWERS THIS MORNING TO EVENTUALLY ORGANIZED INTO
BROKEN BAND OF SHOWERS BY MID AFTERNOON.
MAX TEMPS TODAY HIGHLY DEPENDENT UPON WHEN SHOWER COVERAGE
INCREASES. A DELAY IN THE ARRIVAL OF SHOWERS AT ANY ONE SPOT WILL
TRANSLATE TO WARMER HIGH TEMPS. USED A BLEND OF MOS
GUIDANCE...YIELDING MAX TEMPS LOWER 70S NW TO MID-UPPER 70S EAST-SE.
TONIGHT...MAY SEE A TEMPORARY LULL IN SHOWER COVERAGE DEVELOP LATE
IN THE DAY/EARLY EVENING AS S/W TRAVERSES ACROSS THE REGION. EXPECT
TO SEE AN UPTICK IN SHOWER COVERAGE AFTER SUNSET AS SFC COLD FRONT
ASSOCIATED WITH THE NORTHERN STREAM S/W APPROACHES/CROSSES OUR
REGION. THIS BAND OF SHOWERS SHOULD EXIT THE PIEDMONT AROUND OR
SHORTLY AFTER MIDNIGHT...AND THE COASTAL PLAIN COUNTIES PRIOR TO
DAYBREAK SATURDAY. EXPECT PARTIAL CLEARING BEHIND THE EXITING FRONT
THOUGH RESIDUAL LOW LEVEL MOISTURE COUPLED WITH A LIGHT WIND REGIME
SUGGEST A GOOD POTENTIAL FOR LOW CLOUDS TO DEVELOP ACROSS THE AREA
OVERNIGHT. MIN TEMPS MID-UPPER 50S NW-LOWER 60S SE.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 350 AM FRIDAY...
NORTHERN STREAM S/W CROSSES OVERHEAD SATURDAY. WHILE MOISTURE
BASICALLY CONFINED TO THE LOWEST 10K FEET...MID LEVEL LAPSE RATES
BETWEEN 6 AND 6.5 C/KM ALONG WITH HEATING SHOULD TRIGGER A FEW LOW
TOPPED SHOWERS IN THE LATE MORNING AND AFTERNOON HOURS. EXPECT
HIGHEST RISK FOR SHOWERS (1:4 CHANCE) OVER THE FAR NE PIEDMONT AND
THE COASTAL PLAIN. SHOWER THREAT SHOULD DIMINISH/END PRIOR TO
SUNSET.
EARLY MORNING LOW CLOUDS SHOULD LIFT INTO A SCATTERED/BROKEN DECK BY
LATE MORNING. THE PARTIAL SUNSHINE AND A RELATIVELY MILD START TO
THE DAY SHOULD ALLOW TEMPS TO RECOVER INTO THE MID-UPPER
70S...WARMEST IN THE SW WHERE MORE SUN/FEWER (IF ANY) SHOWERS
EXPECTED.
HIGH PRESSURE OVER SOUTHERN SECTIONS OF ONTARIO/QUEBEC BUILDS SWD
INTO THE SOUTHERN APPALACHIANS SATURDAY NIGHT. THIS WILL LEAD TO
CLEARING SKIES AND SLIGHTLY COOLER TEMPS. MIN TEMPS BY EARLY SUNDAY
50-55 DEGREES.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 305 AM FRIDAY...
SUNDAY THROUGH MONDAY NIGHT: MID LEVEL RIDGING WILL BUILD BACK OVER
THE AREA FOR THE SECOND HALF OF THE WEEKEND INTO EARLY NEXT WEEK.
MEANWHILE SURFACE HIGH PRESSURE... INITIALLY LOCATED OVER THE REGION
TO START THE PERIOD WILL SHIFT TO THE COAST AND THEN OFFSHORE SUNDAY
EVENING INTO EARLY NEXT WEEK. THIS WILL RESULT IN A DRY AND WARMING
FORECAST FOR THIS TIME FRAME. HIGHS SUNDAY ARE EXPECTED TO RANGE
FROM THE LOWER 70S NE TO THE UPPER 70S SW. HIGHS MONDAY SHOULD BE A
COUPLE OF CATEGORIES WARMER WITH A SOUTHERLY RETURN FLOW AROUND
OFFSHORE HIGH PRESSURE. THUS... EXPECT HIGHS ON MONDAY WILL BE IN
THE LOWER TO MID 80S. LOWS WILL FOLLOW A SIMILAR TREND... INCREASING
EACH MORNING. LOWS ARE EXPECTED TO BE IN 50S FOR MONDAY MONDAY
MORNING... AND NEAR 60/LOWER 60S ON TUESDAY MORNING.
TUESDAY THROUGH THURSDAY: THE MID LEVEL RIDGE WILL HAVE FLATTENED BY
TUESDAY MORNING AS A S/W DISTURBANCE TRACKS EASTWARD ACROSS THE
GREAT LAKES AND NORTHEAST U.S. MONDAY NIGHT INTO TUESDAY. HOW THIS
SYSTEM INTERACTS WITH THE EASTERN CANADA DEEP MID/UPPER LEVEL LOW
WILL PLAY A ROLE ON HOW FAR SOUTH THE ASSOCIATED COLD FRONT (FROM
THE S/W TRACKING EAST ACROSS THE NORTHEASTERN U.S.) MEDIUM RANGE
MODELS HAVE STRUGGLED WITH HOW FAR SOUTH THE FRONT WILL MAKE IT NEXT
WEEK. THE 00Z/22ND GFS CONTINUES TO DRIVE THE FRONT SOUTHWARD
THROUGH THE AREA TUESDAY NIGHT INTO WEDNESDAY... WHILE THE 00Z/22ND
ECMWF STALLS THE FRONT JUST TO OUR NORTH AND NORTHEAST. THUS...
CONFIDENCE REMAINS LOW FOR TEMPS TUESDAY NIGHT ONWARD AND PRECIP
CHANCES FOR TUESDAY EVENING INTO WEDNESDAY. FOR NOW WILL GO WITH
ONLY A SLIGHT CHANCE OF SHOWERS AND STORMS FROM LATE TUESDAY THROUGH
WEDNESDAY. TEMPS WILL BE GREATLY DEPENDENT BY THE PLACEMENT OF THE
FRONT... WITH LIKELY A LARGE TEMPERATURE GRADIENT NEAR THE FRONT.
REGARDLESS THOUGH... TUESDAY LOOKS TO BE WARM... WITH HIGHS IN THE
MID TO UPPER 80S. WILL FOLLOW CLOSE TO WPC AND GO WITH HIGHS
WEDNESDAY RANGING FROM THE UPPER 70S NE TO UPPER 80S SW... WITH THE
COLD FRONT BISECTING THE AREA ON WEDNESDAY MORNING. LOWS ARE
EXPECTED TO RANGE FROM THE MID TO UPPER 50S TO THE LOWER 60S.
THE NEXT COLD FRONT IS EXPECTED TO APPROACH THE AREA ON THURSDAY WITH
INCREASING CHANCES FOR SHOWERS AND STORMS... WITH HIGHS NEAR 80
NORTH TO THE MID TO UPPER 80S SOUTH... WITH THE STALLED FRONT
EXPECTED TO BE TO THE NORTH OF THE AREA BY THURSDAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1240 PM FRIDAY...
DIFFICULT AVIATION FORECAST AS ROUNDS OF SHOWERS AND ISOLATED STORMS
WILL LEAD TO WIDELY VARYING CIGS/VSBYS FOR THE NEXT 12-15 HOURS. A
WARM MOIST FLOW FROM THE SW ALONG WITH AN APPROACHING COLD FRONT AND
UPPER LEVEL DISTURBANCE WILL GENERATE INCREASING COVERAGE OF SHOWERS
AT ALL TERMINALS THROUGH THIS AFTERNOON. IFR TO LOW-END MVFR CIGS
BETWEEN 500 AND 1500 FT AGL ARE LIKELY WITHIN THE MODERATE TO HEAVY
SHOWERS WITH IFR VSBYS... AND WHEN RAIN IS LIGHT OR ABSENT... THE
LOWER CLOUDS WILL BECOME SCATTERED WITH VFR CIGS ABOVE 4KFT AGL AND
MVFR-VFR VSBYS. THE BEST CHANCE FOR DOMINANT SUB-VFR CONDITIONS ARE
18-22Z AND 01Z-05Z AT RDU/FAY/RWI... AND 22Z-02Z AT INT/GSO. A
THUNDERSTORM IS POSSIBLE THIS AFTERNOON... MAINLY AT RDU/FAY/RWI.
THE SHOWERS WILL BE ON A DIMINISHING TREND IN COVERAGE AND INTENSITY
FROM WEST TO EAST LATER THIS EVENING INTO THE OVERNIGHT HOURS (03Z-
08Z)... BUT WITH LIGHT SURFACE WINDS AND HIGH HUMIDITY LINGERING
OVER CENTRAL NC AHEAD OF THE COLD FRONT... LOWER CIGS (AGAIN IN THE
500-1500 AGL RANGE) IN THE FORM OF BROKEN SHALLOW STRATUS CLOUDS ARE
LIKELY TO RE-DEVELOP TONIGHT AS THE RAIN TAPERS DOWN... AND ISOLATED
POCKETS OF MVFR-IFR VSBYS ARE POSSIBLE AS WELL. THESE LOW CLOUDS
WILL DISPERSE AND LIFT... LEADING TO VFR-DOMINANT CONDITIONS
AT ALL SITES AFTER 14Z SAT.
LOOKING BEYOND 18Z SAT... A FEW SHOWERS ARE POSSIBLE ESPECIALLY AT
NORTHERN TERMINALS SAT AFTERNOON BUT ANY SUB-VFR CONDITIONS WOULD BE
VERY BRIEF. OTHERWISE... THE COLD FRONT WILL FINALLY DROP SE THROUGH
THE AREA SAT NIGHT WITH HIGH PRESSURE BUILDING INTO AND OVER THE
AREA SUN/MON BEFORE SHIFTING OFFSHORE THROUGH MIDWEEK... LEADING TO
VFR CONDITIONS AND A WARMING TREND SUN INTO TUE. AN APPROACHING
BACKDOOR FRONT MAY BRING A FEW SHOWERS TO NORTHERN TERMINALS TUE
NIGHT/WED BUT VFR CONDITIONS SHOULD STILL PREVAIL. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS/HARTFIELD
NEAR TERM...HARTFIELD/WSS
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1204 PM CDT FRI APR 22 2016
.UPDATE...
ISSUED AT 1204 PM CDT FRI APR 22 2016
LATEST SURFACE ANALYSIS SHOWS INCREASING SOUTHEAST WINDS ACROSS
SOUTHWEST NORTH DAKOTA...ON TRACK WITH OUR GRIDDED WIND DATA. THE
LATEST HRRR EXPERIMENTAL CONTINUES TO PORTRAY DEWPOINTS IN THE 30S
AND THIS SEEMS REASONABLE GIVEN THE UPSTREAM OBSERVATIONS IN SOUTH
DAKOTA. NO CHANGES TO CURRENT FORECAST AT THIS TIME.
UPDATE ISSUED AT 1006 AM CDT FRI APR 22 2016
ONCE AGAIN...NO SIGNIFICANT CHANGES WITH THIS UPDATE. MORNING
SURFACE ANALYSES REVEAL SURFACE PRESSURE FALLS BEGINNING ACROSS
EASTERN MT AND THE WESTERN DAKOTAS AS A REFLECTION OF WARM AIR
ADVECTION ALOFT. THIS IS INDUCING INCREASING SOUTHEAST FLOW AND
GIVEN UPSTREAM OBSERVED DEWPOINTS IN THE 30S TO AROUND 40 F FROM
SD INTO NEB...SOME MODEST LOW-LEVEL MOISTURE ADVECTION WILL OCCUR
THIS AFTERNOON AND EVENING. GUIDANCE...INCLUDING THE EXPERIMENTAL/
ESRL-RUN HRRR THAT HAS VERIFIED WELL LATELY...SUGGESTS HUMIDITIES
IN FAR SOUTHWEST ND WILL NOT FALL BELOW 25 PERCENT ACROSS A LARGE
ENOUGH AREA TO WARRANT ISSUANCE OF A RED FLAG WARNING.
UPDATE ISSUED AT 640 AM CDT FRI APR 22 2016
NO SIGNIFICANT CHANGE WITH THIS FORECAST UPDATE OTHER THAN TO
BLEND TO OBSERVED TRENDS THROUGH 11 UTC. WILL CONTINUE TO MONITOR
CONDITIONS ACROSS SOUTHWEST NORTH DAKOTA THROUGH THE DAY SHOULD A
RED FLAG WARNING BECOME NECESSARY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT FRI APR 22 2016
POTENTIAL NEAR CRITICAL FIRE WEATHER CONDITIONS FAR SOUTHWEST
TODAY HIGHLIGHT THE SHORT TERM FORECAST. SEE THE FIRE WEATHER
DISCUSSION BELOW FOR DETAILS.
A STATIONARY FRONT ACROSS NORTH CENTRAL THROUGH SOUTHEAST MONTANA
THIS MORNING WILL PROPAGATE EAST TODAY AS A WARM FRONT AND
APPROACH FAR SOUTHWEST NORTH DAKOTA LATE THIS AFTERNOON. AS A
RESULT...A LARGE TEMPERATURE GRADIENT IS EXPECTED ACROSS THE AREA
TODAY WITH HIGHS IN THE 50S ACROSS THE TURTLE MOUNTAINS TO NEAR 80
ACROSS THE FAR SOUTHWEST. BREEZY SOUTHEAST WINDS OF 20 TO 30 MPH
ARE EXPECTED ACROSS THE WEST THIS AFTERNOON WITH A TIGHTENING
PRESSURE GRADIENT AND ISALLOBARIC FORCING FROM PRESSURE FALLS
AHEAD OF THE WARM FRONT. GIVEN GOOD AGREEMENT...A BLEND OF THE 00
UTC GLOBAL AND HIGH RESOLUTION SUITES WERE USED...WITH PREFERENCE
GIVEN TO THE WARMER EDGE OF GUIDANCE FOR TEMPERATURES ACROSS THE
WEST PER VERIFICATION TRENDS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 302 AM CDT FRI APR 22 2016
WIDESPREAD PRECIPITATION LATE SATURDAY NIGHT THROUGH MONDAY
MORNING HIGHLIGHTS THE EXTENDED FORECAST.
THE 00 UTC DETERMINISTIC AND ENSEMBLE GLOBAL SUITES ARE IN GOOD
AGREEMENT ON THE UPPER LOW COMING ON SHORE TO CALIFORNIA AND
OREGON TODAY PROPAGATING INTO THE NORTHERN PLAINS SATURDAY NIGHT
THROUGH MONDAY MORNING. THE TREND OVER THE LAST 24 HOURS HAS BEEN
FOR A SLIGHT NORTHWARD SHIFT IN THE LOW TRACK...YIELDING MORE
WIDESPREAD AND HIGHER PRECIPITATION CHANCES ACROSS MUCH OF WESTERN
AND CENTRAL NORTH DAKOTA.
REGARDING DETAILS...SURFACE CYCLOGENESIS IS FORECAST ACROSS
WESTERN SOUTH DAKOTA SATURDAY NIGHT INTO SUNDAY MORNING WITH
RESULTING INCREASING MOISTURE TRANSPORT INTO THE REGION. WITH
STRONG DIFFLUENCE ALOFT AND STEEP MID LEVEL LAPSE
RATES...THUNDERSTORMS ARE POSSIBLE SATURDAY NIGHT INTO SUNDAY
MORNING MORNING. CERTAINLY COULD NOT RULE OUT A FEW STRONG
ELEVATED STORMS ACROSS SOUTHERN NORTH DAKOTA WITH MUCAPE OF
500-1000 J/KG AT 750 MB AND THE PRESENCE OF STRONG DEEP LAYER
SHEAR. PRECIPITATION ACROSS NORTH DAKOTA IS FORECAST TO TRANSITION
TO STRATIFORM THROUGH THE DAY ON SUNDAY AS THE SYSTEM BECOMES
NEARLY VERTICALLY STACKED ACROSS SOUTH CENTRAL SOUTH DAKOTA. AS
SUB- FREEZING LOW LEVEL AIR ADVECTS INTO THE SYSTEM SUNDAY NIGHT
INTO MONDAY MORNING...RAIN MAY TRANSITION TO SNOW WITH PERHAPS
LIGHT ACCUMULATIONS ON GRASSY SURFACES. WIDESPREAD RAINFALL TOTALS
OVER AN INCH ARE STILL FORECAST SOUTH OF US HIGHWAY 2.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1204 PM CDT FRI APR 22 2016
VFR CONDITIONS ARE FORECAST ACROSS WESTERN AND CENTRAL ND THROUGH
THE 18 UTC TAF CYCLE. HOWEVER...THERE IS A LOW PROBABILITY OF MVFR
OR EVEN IFR CEILINGS /STRATUS/ DEVELOPING OVER THE SOUTHERN JAMES
RIVER VALLEY BETWEEN 09 AND 15 UTC. OTHERWISE...BREEZY SOUTHEAST
WINDS WITH GUSTS TO 30 KT ARE EXPECTED ACROSS WESTERN ND AT KISN AND
KDIK THIS AFTERNOON. LOW-LEVEL WIND SHEAR IS POSSIBLE AT KDIK...KBIS
AND KJMS TONIGHT AND EARLY SATURDAY MORNING.
&&
.FIRE WEATHER...
ISSUED AT 1006 AM CDT FRI APR 22 2016
NEAR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED ACROSS FAR
SOUTHWEST NORTH DAKOTA TODAY IN GOLDEN VALLEY...SLOPE...BILLINGS
AND BOWMAN COUNTIES. HIGH TEMPERATURES TODAY WILL BE IN THE UPPER
70S WITH SOUTHEAST WINDS OF 20 TO 25 MPH...GUSTING AT 30 TO 35
MPH. OF GREATEST UNCERTAINTY ARE FORECAST RELATIVE HUMIDITY
VALUES. AFTERNOON RELATIVE HUMIDITY MAY FALL INTO THE 20 TO 25
PERCENT RANGE THIS AFTERNOON...WITH EVEN LOWER VALUES POSSIBLE
ACROSS THE BORDER IN MONTANA. HOWEVER...THE LATEST INDICATIONS ARE
THAT HUMIDITY VALUES WILL NOT FALL LOW ENOUGH OVER A LARGE ENOUGH
AREA OF ANY GIVEN COUNTY TO WARRANT ISSUANCE OF A RED FLAG WARNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...AYD
LONG TERM...AYD
AVIATION...CJS
FIRE WEATHER...AYD/CJS
AREA FORECAST DISCUSSION
NWS PORTLAND OR
325 PM PDT FRI APR 22 2016
CORRECTED MARINE AND AVIATION SECTIONS
.SYNOPSIS...A COOL LOW PRESSURE SYSTEM WILL BE OVER OREGON FOR
MORE SHOWERS AND POSSIBLY AN AFTERNOON THUNDERSTORM...THEN MOVE EAST
OF SOUTHWEST WASHINGTON AND NORTHWEST OREGON LATER TONIGHT AND EARLY
SATURDAY FOR DECREASING SHOWERS. THE NEXT SYSTEM WILL SPREAD MORE
SHOWERS INTO THE FORECAST AREA LATER SATURDAY AND SATURDAY NIGHT. THE
ASSOCIATED EVEN COLDER LOW WILL NOT MOVE OUT OF THE FORECAST AREA
UNTIL LATER MONDAY AND MONDAY NIGHT. THIS LOW WILL DROP SNOW LEVELS
BELOW THE CASCADE PASSES SATURDAY NIGHT THROUGH MONDAY... AND SEVERAL
INCHES OF SNOW ARE POSSIBLE. THE NEXT SYSTEM IS EXPECTED TUESDAY
NIGHT AND WEDNESDAY AS UNSETTLED WEATHER CONTINUES.
&&
.SHORT TERM...SHOWER ACTIVITY IS SLOW TO INCREASE THIS AFTERNOON.
CURRENT INSTABILITY ANALYSIS AND HRRR MODEL TRENDS SHOW STRONGER
SHOWER ACTIVITY IN THE NEXT FEW HOURS. THE HRRR MODEL RECENTLY
DEPICTING STRONGER SHOWERS OVER THE COAST RANGE AND OREGON CASCADES
WITH A FEW CELLS OVER THE CENTRAL AND SOUTH VALLEY FROM ABOUT 3 PM TO
6 PM. THERE WAS A REPORT OF A FUNNEL CLOUD NEAR MONMOUTH LATE THIS
MORNING. NAM BUFR SOUNDING SHOW WEAK LOW LEVEL DIRECTIONAL WIND SHEAR
FOR THAT TIME SO ITS POSSIBLE THAT THE INITIAL RELEASE OF INSTABILITY
ALLOWED A SHOWER TO SPIN UP THIS FUNNEL. MODEL SOUNDINGS SHOW LESS
FAVORABLE CONDITIONS FOR FUNNEL CLOUDS THIS AFTERNOON.
MODELS SHOW THE AIR MASS STABILIZING A LOT QUICKER THAN THE THU NIGHT
SYSTEM SO EXPECT THREAT OF THUNDERSTORMS TO QUICKLY DIMINISH BY 7 OR
8 PM. PRECIPITATION AMOUNTS DO NOT LOOK AS HEAVY THIS AFTERNOON AND
EVENING IN A LARGE SCALE SENSE...THOUGH INDIVIDUAL CELLS COULD STILL
PRODUCE HEAVY RAIN. THE UPPER LOW MOVES EAST OF THE FORECAST AREA
LATER TONIGHT AND SATURDAY MORNING WITH SHOWER ACTIVITY MAINLY OVER
THE MOUNTAINS THEN INCREASE AGAIN OVER THE LOWLANDS IN THE AFTERNOON.
THERE IS INDICATION OF RENEWED INSTABILITY SAT AFTERNOON BUT
SHOWERS SHOULD REMAIN CAPPED BELOW -10C LEVEL. THE NEXT SYSTEM
APPROACHES LATER SATURDAY AND PUSHES A FRONT INTO THE AREA SATURDAY
NIGHT FOR MORE SHOWERS. THE ASSOCIATED COOL UPPER TROUGH SAGS ACROSS
THE AREA SAT NIGHT AND SUN WITH LOWERING SNOW LEVELS. THE CASCADE
PASSES WILL PROBABLY SEE SEVERAL INCHES OF NEW SNOW BY SUN AFTERNOON.
THE COOL UPPER TROUGH WILL BRING ALSO INCREASE INSTABILITY SO WILL
INCLUDE A SLIGHT CHANCE OF THUNDERSTORMS ON SUN.
TOTAL RAINFALL ACCUMULATIONS THROUGH SUNDAY COULD REACH 1 TO 1.5
ALONG THE COAST AND IN THE MOUNTAINS...AND FROM 0.50 TO 1 INCHES IN
THE VALLEYS. THUS THIS LOOKS TO BE A REASONABLY WET PERIOD AFTER OUR
RECENT COUPLE OF UNSEASONABLY WARM SPELLS. /MH
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY. SHOWERS START TAPERING OFF
MONDAY NIGHT AS SHORTWAVE RIDGING BUILDS IN TO THE PACIFIC
NORTHWEST. TUESDAY FOR THE MOST PART LOOKS DRY. MODELS HAVE BEEN
VERY INCONSISTENT WITH THE FORECAST FOR MID-TO-LATE WEEK NEXT
WEEK...BUT IT IS STARTING TOO LOOK LIKE THE NEXT SYSTEM WILL
PROBABLY DROP TO OUR SOUTH. THIS MAY CLIP SOUTHERN PARTS OF OUR
AREA...BUT AREAS SALEM NORTHWARD WILL PROBABLY STAY DRY. HAVE LEFT A
SLIGHT CHANCE OF SHOWERS ACROSS OUR AREA TO ACCOUNT FOR THE
INCONSISTENCY WITH THE TRACK OF THIS SYSTEM BETWEEN MODEL RUNS. WILL
PROBABLY SEE FORECAST TREND DRIER IF MODELS CONTINUE TO SHOW THIS
SYSTEM DROPPING SOUTH OF US. ON THURSDAY WE SEE A SHORTWAVE TROUGH
DROP DOWN OUT OF CANADA ALONG THE EAST SIDE OF THE CASCADES BRINGING
SHOWERS TO THE CASCADE CREST...BUT FURTHER WEST WILL PROBABLY BE DRY
AS RIDGING STARTS TO BUILD BACK OVER THE EASTERN PACIFIC ALONG THE
WEST COAST. MODELS DIFFER ABOUT WHETHER THIS RIDGE PERSISTS INTO THE
WEEKEND...OR IS ONLY A TEMPORARY REPRIEVE BEFORE MORE RAIN MOVES IN
OVER THE WEEKEND...THEREFORE CONFIDENCE IS LOW AT THIS TIME IN THE
FORECAST FOR FRIDAY AND BEYOND. -MCCOY
&&
.AVIATION...MOIST AND UNSTABLE AIR MASS CONTINUES TO PRODUCE
SCATTERED SHOWERS ACROSS THE FORECAST AREA...THOUGH CONDITIONS IN
GENERAL REMAIN VFR. HEAVIER SHOWERS MAY BRIEFLY LOWER CIGS/VSBYS
INTO THE MVFR CATEGORY BEFORE MOVING ALONG SLOWLY TO THE NORTH.
ISOLD TSRA REMAIN POSSIBLE DUE TO THE INSTABILITY...THOUGH TODAYS
CONVECTION SHOULD BE LESS ORGANIZED THAN IT HAS BEEN THE PAST
COUPLE DAYS. SHOWERS SHOULD TAPER OFF QUICKLY AFTER SUNSET DUE TO
LOSS OF DAYTIME HEATING. SOME RELATIVE CLEARING IS POSSIBLE THIS
EVENING...WHICH COULD LEAD TO SOME VERY THIN PATCHES OF GROUND FOG
AT THE MORE FOG-PRONE TERMINALS LIKE KEUG/KHIO THIS EVENING.
HIGHER CLOUD COVER IS EXPECTED TO INCREASE SAT MORNING AHEAD OF AN
APPROACHING WEAK COLD FRONT...WHICH SHOULD MITIGATE FOG FORMATION.
WILL HINT AT SOME MIFG IN KHIO/KEUG TAFS...BUT WILL KEEP
PREVAILING WX VFR UNTIL SHOWERS ARRIVE AHEAD OF THE COLD FRONT
AROUND 18Z SAT. THERE IS ALSO ABOUT A 40 PERCENT CHANCE OF A LOW
CLOUD DECK DEVELOPING WITH BASES AROUND 2000-3000 FT LATER
TONIGHT OR SAT AM...WHICH WOULD ALSO INHIBIT FOG FORMATION IF IT
DEVELOPS.
KPDX AND APPROACHES...EXPECT VFR TO PREVAIL MOST OF THE TIME
THROUGH TONIGHT WITH GENERAL LIGHT-MDT S-SW FLOW. ANOTHER ROUND
OF SHRA/ISOLD TSRA IS DEVELOPING THIS AFTERNOON DUE TO THE MOIST
AND UNSTABLE AIR MASS. CONVECTION THIS AFTERNOON SHOULD BE LESS
ORGANIZED THAN THE LAST COUPLE DAYS...BUT COULD STILL PRODUCE
BRIEF MVFR AND LOCALIZED GUSTY OUTFLOW UP TO 25 KT. SHRA SHOULD
DISSIPATE QUICKLY AFTER 02Z WITH LOSS OF DAYTIME HEATING. AREAS OF
MVFR WILL LIKELY DEVELOP AS LOW CLOUDS FORM LATER TONIGHT...THOUGH
ONLY ABOUT A 40 PERCENT CHANCE OF MVFR IMPACTING THE PDX TERMINAL
ITSELF. WEAGLE
&&
.MARINE...S-SW WINDS ARE EASING THIS AFTERNOON AFTER AN EARLIER
SURGE BROUGHT SOME GUSTS TO 25 KT TO MOST OF THE COASTAL WATERS.
WILL HOLD ON TO THE SCA FOR WIND IN THE NORTHERN WATERS UNTIL
4 PM FOR THE NORTHERN WATERS...AS THERE ARE STILL A FEW GUSTS
NEAR 20 KT BEING REPORTED ALONG THE COAST. LOW CENTER PRESENTLY
NEAR 43N/128W WILL SLOWLY MEANDER ONSHORE INTO SOUTHERN OR
TONIGHT/EARLY SAT MORNING...AND THERE MAY BE A BRIEF SURGE OF S-SW
WINDS GUSTING TO 20 KT EARLY SAT DUE TO THE REMNANTS OF THE LOWS
OCCLUDED FRONT. THAT SAID...IT APPEARS WINDS WILL REMAIN BELOW SCA
CRITERIA SAT MORNING. A BATCH OF WESTERLY SWELL ASSOCIATED WITH
THE LOW IS AIMING FOR THE CENTRAL/S OREGON COAST AND SHOULD PUSH
SEAS BACK UP TO 10+ FT TONIGHT. WILL ISSUE AN SCA FOR SEAS FOR OUR
SOUTHERN WATERS LATER TONIGHT/SAT.
HIGH PRESSURE BUILDING IN BEHIND THE LOW WILL CAUSE WINDS TO VEER
NW AND INCREASE SAT NIGHT/SUN...WITH GUSTS 20-25 KT PERSISTING
THROUGH EARLY MON. HIGH PRES RIDGE AXIS WILL SLIDE ACROSS THE
WATERS LATER MON/TUE FOR LIGHTER WINDS AND SEAS. WEAGLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 PM PDT THIS AFTERNOON
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD
OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 11 PM THIS EVENING
TO 5 PM PDT SATURDAY FOR COASTAL WATERS FROM CASCADE HEAD
OR TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 2 AM TO
9 AM PDT SATURDAY.
&&
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 PM PDT THIS AFTERNOON
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD
OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM PDT THIS MORNING FOR
COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60
NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 2 AM TO
9 AM PDT SATURDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS PORTLAND OR
225 PM PDT FRI APR 22 2016
.SYNOPSIS...A COOL LOW PRESSURE SYSTEM WILL BE OVER OREGON FOR
MORE SHOWERS AND POSSIBLY AN AFTERNOON THUNDERSTORM...THEN MOVE EAST
OF SOUTHWEST WASHINGTON AND NORTHWEST OREGON LATER TONIGHT AND EARLY
SATURDAY FOR DECREASING SHOWERS. THE NEXT SYSTEM WILL SPREAD MORE
SHOWERS INTO THE FORECAST AREA LATER SATURDAY AND SATURDAY NIGHT. THE
ASSOCIATED EVEN COLDER LOW WILL NOT MOVE OUT OF THE FORECAST AREA
UNTIL LATER MONDAY AND MONDAY NIGHT. THIS LOW WILL DROP SNOW LEVELS
BELOW THE CASCADE PASSES SATURDAY NIGHT THROUGH MONDAY... AND SEVERAL
INCHES OF SNOW ARE POSSIBLE. THE NEXT SYSTEM IS EXPECTED TUESDAY
NIGHT AND WEDNESDAY AS UNSETTLED WEATHER CONTINUES.
&&
.SHORT TERM...SHOWER ACTIVITY IS SLOW TO INCREASE THIS AFTERNOON.
CURRENT INSTABILITY ANALYSIS AND HRRR MODEL TRENDS SHOW STRONGER
SHOWER ACTIVITY IN THE NEXT FEW HOURS. THE HRRR MODEL RECENTLY
DEPICTING STRONGER SHOWERS OVER THE COAST RANGE AND OREGON CASCADES
WITH A FEW CELLS OVER THE CENTRAL AND SOUTH VALLEY FROM ABOUT 3 PM TO
6 PM. THERE WAS A REPORT OF A FUNNEL CLOUD NEAR MONMOUTH LATE THIS
MORNING. NAM BUFR SOUNDING SHOW WEAK LOW LEVEL DIRECTIONAL WIND SHEAR
FOR THAT TIME SO ITS POSSIBLE THAT THE INITIAL RELEASE OF INSTABILITY
ALLOWED A SHOWER TO SPIN UP THIS FUNNEL. MODEL SOUNDINGS SHOW LESS
FAVORABLE CONDITIONS FOR FUNNEL CLOUDS THIS AFTERNOON.
MODELS SHOW THE AIR MASS STABILIZING A LOT QUICKER THAN THE THU NIGHT
SYSTEM SO EXPECT THREAT OF THUNDERSTORMS TO QUICKLY DIMINISH BY 7 OR
8 PM. PRECIPITATION AMOUNTS DO NOT LOOK AS HEAVY THIS AFTERNOON AND
EVENING IN A LARGE SCALE SENSE...THOUGH INDIVIDUAL CELLS COULD STILL
PRODUCE HEAVY RAIN. THE UPPER LOW MOVES EAST OF THE FORECAST AREA
LATER TONIGHT AND SATURDAY MORNING WITH SHOWER ACTIVITY MAINLY OVER
THE MOUNTAINS THEN INCREASE AGAIN OVER THE LOWLANDS IN THE AFTERNOON.
THERE IS INDICATION OF RENEWED INSTABILITY SAT AFTERNOON BUT
SHOWERS SHOULD REMAIN CAPPED BELOW -10C LEVEL. THE NEXT SYSTEM
APPROACHES LATER SATURDAY AND PUSHES A FRONT INTO THE AREA SATURDAY
NIGHT FOR MORE SHOWERS. THE ASSOCIATED COOL UPPER TROUGH SAGS ACROSS
THE AREA SAT NIGHT AND SUN WITH LOWERING SNOW LEVELS. THE CASCADE
PASSES WILL PROBABLY SEE SEVERAL INCHES OF NEW SNOW BY SUN AFTERNOON.
THE COOL UPPER TROUGH WILL BRING ALSO INCREASE INSTABILITY SO WILL
INCLUDE A SLIGHT CHANCE OF THUNDERSTORMS ON SUN.
TOTAL RAINFALL ACCUMULATIONS THROUGH SUNDAY COULD REACH 1 TO 1.5
ALONG THE COAST AND IN THE MOUNTAINS...AND FROM 0.50 TO 1 INCHES IN
THE VALLEYS. THUS THIS LOOKS TO BE A REASONABLY WET PERIOD AFTER OUR
RECENT COUPLE OF UNSEASONABLY WARM SPELLS. /MH
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY. SHOWERS START TAPERING OFF
MONDAY NIGHT AS SHORTWAVE RIDGING BUILDS IN TO THE PACIFIC
NORTHWEST. TUESDAY FOR THE MOST PART LOOKS DRY. MODELS HAVE BEEN
VERY INCONSISTENT WITH THE FORECAST FOR MID-TO-LATE WEEK NEXT
WEEK...BUT IT IS STARTING TOO LOOK LIKE THE NEXT SYSTEM WILL
PROBABLY DROP TO OUR SOUTH. THIS MAY CLIP SOUTHERN PARTS OF OUR
AREA...BUT AREAS SALEM NORTHWARD WILL PROBABLY STAY DRY. HAVE LEFT A
SLIGHT CHANCE OF SHOWERS ACROSS OUR AREA TO ACCOUNT FOR THE
INCONSISTENCY WITH THE TRACK OF THIS SYSTEM BETWEEN MODEL RUNS. WILL
PROBABLY SEE FORECAST TREND DRIER IF MODELS CONTINUE TO SHOW THIS
SYSTEM DROPPING SOUTH OF US. ON THURSDAY WE SEE A SHORTWAVE TROUGH
DROP DOWN OUT OF CANADA ALONG THE EAST SIDE OF THE CASCADES BRINGING
SHOWERS TO THE CASCADE CREST...BUT FURTHER WEST WILL PROBABLY BE DRY
AS RIDGING STARTS TO BUILD BACK OVER THE EASTERN PACIFIC ALONG THE
WEST COAST. MODELS DIFFER ABOUT WHETHER THIS RIDGE PERSISTS INTO THE
WEEKEND...OR IS ONLY A TEMPORARY REPRIEVE BEFORE MORE RAIN MOVES IN
OVER THE WEEKEND...THEREFORE CONFIDENCE IS LOW AT THIS TIME IN THE
FORECAST FOR FRIDAY AND BEYOND. -MCCOY
&&
.AVIATION...PLENTY OF SHOWERS EXPECTED TODAY ACROSS THE REGION...
THOUGH THE PREVAILING FLIGHT CATEGORY ON AVERAGE WILL BE VFR.
OCCASIONAL MVFR CIGS/VSBYS WILL OCCUR WITH HEAVIER SHOWERS. DRY
SLOT BEHIND INITIAL BATCH OF SHOWERS...PRESENTLY S OF KSLE...WILL
LIKELY BRING A BREAK IN THE ACTIVITY FROM S TO N DURING THE MIDDAY
HOURS. HOWEVER IT DOES APPEAR THERE WILL BE ENOUGH INSTABILITY FOR
ADDITIONAL SHOWERS AND ISOLD TSRA TO DEVELOP LATER THIS AFTERNOON
AND EVENING...THOUGH TODAYS CONVECTION SHOULD BE LESS ORGANIZED
THAN IT HAS BEEN THE PAST COUPLE DAYS.
KPDX AND APPROACHES...FIRST BATCH OF HEAVY SHOWERS FROM EARLIER
THIS MORNING HAS GENERALLY MOVED NW OF THE PDX METRO AREA...SO
EXPECT VFR TO PREVAIL MUCH OF THE DAY. COULD BE AREAS OF -RA AND
MVFR PERSISTING UNTIL ABOUT 18Z. ANOTHER ROUND OF SHRA/ISOLD TSRA
POSSIBLE AFTER 20Z...BUT SHOULD BE LESS ORGANIZED THAN PREVIOUS
CONVECTION THE LAST COUPLE DAYS. WEAGLE
&&
.MARINE...COLD FRONT CONTINUES TO LIFT N THROUGH THE NORTHERN
OREGON COASTAL WATERS THIS MORNING...WITH A BRIEF BURST OF S WINDS
BEHIND IT. BUOY 46050 HAD A BRIEF GUST TO 33 KT AT 13Z...LIKELY
AIDED BY A SQUALL LINE THAT DEVELOPED WITH THE FRONT. THIS APPEARS
TO HAVE STIRRED UP SEAS LOCALLY...WITH BUOY 46050 REPORTING 9 FT
AT 8 SEC AT THE MOMENT. DECIDED NOT TO ISSUE AN SCA FOR SEAS DUE
TO THE APPARENTLY LOCALIZED NATURE OF THESE SEAS...AND EXPECT THE
SEAS TO SETTLE DOWN TO 5-7 FT LATER TODAY. HOWEVER A BATCH OF
WESTERLY SWELL IS AIMING FOR THE CENTRAL/S OREGON COAST AND SHOULD
PUSH SEAS BACK UP TO 10+ FT TONIGHT. WILL LIKELY NEED TO ISSUE AN
SCA FOR SEAS FOR AT LEAST OUR SOUTHERN WATERS LATER TONIGHT/SAT.
OTHERWISE BROAD LOW PRESSURE WILL PREVAIL OVER THE WATERS THROUGH
THE WEEKEND...CONTINUING THE UNSETTLED WEATHER BUT KEEPING PRES
GRADIENTS RATHER LIGHT FOR LIGHT TO MODERATE S-SW WINDS. NEXT COLD
FRONT CROSSING 150W MAY BRING A BRIEF SURGE IN NW WINDS WITH GUSTS
20-25 KT AS COOL AIR PUSHES IN BEHIND IT SAT NIGHT/SUN AM. HIGH
PRES EXPECTED TO BUILD IN MON/TUE FOR LIGHTER WINDS/SEAS EARLY
NEXT WEEK. WEAGLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 PM PDT THIS AFTERNOON
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD
OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM PDT THIS MORNING FOR
COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60
NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 2 AM TO
9 AM PDT SATURDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
644 PM EDT FRI APR 22 2016
.SYNOPSIS...
A COLD FRONT WILL PUSH THROUGH PA THIS EVENING AND EARLY TONIGHT.
HIGH PRESSURE WILL BUILD INTO THE REGION THIS WEEKEND. ANOTHER
COLD FRONT IS LIKELY TO PUSH ACROSS THE AREA MONDAY NIGHT INTO
TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
WIND SHIFT TO THE NW AT KBFD AND KFKL IN THE LAST HR. SO THE FRONT
MUST BE PUSHING THRU THERE NOW.
HRRR AND RAP NOT HANDLING THE INITIAL AND FIRST HR/TWO OF
QPF AND PLACEMENT OF CONVECTION VERY WELL THIS EVENING. THIS MAY
BE DUE TO THE LIGHT RADAR RETURNS WITH MID CLOUDS AHEAD OF THE
MAIN AREA OF SCT SHRA BEING INGESTED INTO THE MODEL INITS. SHOWERS
IN THE NORTH ARE UNDERDONE AND IN THE SOUTH ARE OVERDONE. IN ANY
CASE...THE SHOWERS ARE MOVING SLOWLY...BUT THE RADAR ESTIMATES ARE
VERY LOW SAVE FOR SOME PINPRICKS OF >0.25IN IN THE THE ONE HR
ESTIMATES. PWATS ARE NOT THAT HIGH...AND ARE ONLY A LITTLE HIGHER
THAN NORMAL FOR LATE APRIL. VERY LITTLE ICE IN THEM AND THUS
LITTLE LIGHTNING. JUST ENOUGH LTG TO KEEP MENTIONS OF IT IN THE
FCST. WILL CARRY ON WITH HIGH POPS IN THE SE FOR THE LATE EVENING
AND EARLY TONIGHT.
PREV...
A DISTINCT AREA OF LLVL RIDGING HELPED TO BRING MAINLY DRY
CONDITIONS ACROSS MUCH OF CENTRAL PENN TODAY BENEATH AN OVC LAYER
OF THICK ALTO CU AND ALTO/CIRROSTRATUS CLOUDS. AN AREA OF SHOWERS
LINKED TO THE NOSE OF A 30-40 KT SWRLY LLJ WAS SLIDING ACROSS OUR
EXTREME SERN COUNTIES ATTM...WHILE A SECOND AREA OF SCATTERED
SHOWERS /ASSOCIATED WITH THE LEFT EXIT REGION OF A SOUTHERLY UPPER
JETLET JUST AHEAD OF THE SFC COLD FRONT/ WAS AFFECTING THE NRN
MTNS AND WRN PLATEAU OF PENN..
MIXED LAYER CAPE WILL INCREASE TO 200-500 J/KG ACROSS SOUTHERN AND
WESTERN PARTS OF THE FCST AREA LATE THIS AFTERNOON AND
EVENING /WITH SOME POCKETS OF CAPE APPROACHING 1000 J/KG
POSSIBLE/. THIS MODEST INCREASE IN INSTAB AHEAD OF THE COLD FRONT
WILL SUPPORT THE DEVELOPMENT OF ISOLATED HEAVIER SHOWERS AND A
FEW LOW-TOPPED TSRA...MAINLY NEAR AND WEST OF RT 219 AND TO THE
SOUTH OF THE RT 22/322 CORRIDOR.
TEMPS AT 18Z ARE NEARING THEIR FORECAST HIGHS /SEVERAL DEG ABV
CLIMO/...IN THE LOWER TO MID 60S ACROSS THE NRN AND WRN MTNS...AND
UPPER 60S TO LOWER 70S ELSEWHERE ACROSS CENTRAL AND SERN PA.
AS THE COLD FRONT SLIDES SE ACROSS THE ALLEGHENIES AND INTO
CENTRAL PENN LATER THIS EVENING THROUGH ABOUT 06Z...THE TIMING
SHOULD COINCIDE NICELY WITH THE EWD PROGRESSION OF AN AREA OF
STRONG UPPER DIFFLUENCE/UVVEL JUST AHEAD OF THE COMPACT UPPER
TROUGH SEEN OVER OHIO LATE THIS AFTERNOON. HRRR AGREES WITH THIS
SCENARIO AND PAINTS OF FEW SMALL AREAS OF ENHANCED CONVECTION AND
QPF OVER THE SOUTHERN HALF TO TWO THIRDS OF THE CWA. ALTHOUGH A
FEW RUMBLES OF THUNDER CAN/T BE RULED OUT...SCATTERED MDT TO
BRIEFLY HEAVY SHRA WILL LIKELY BE THE DOMINANT FORM OF CONVECTION
THIS EVENING AND TONIGHT. ADDITIONAL RAINFALL RANGING FROM 1-2
TENTHS ACROSS THE REGION NORTH OF I-80...AND UP TO 3 TENTHS OF AN
INCH IN THE SOUTH STILL LOOKS IN GOOD SHAPE FORECAST-WISE BASED ON
THE PAST SEVERAL RUNS OF THE HRRR...THE LATEST SREF AND GEFS...AND
12Z OPER MODELS.
WINDS WILL BE VERY LIGHT AND VARIABLE IN DIRECTION TO START THE
AFTERNOON...THEN BECOME SOUTHWESTERLY AT 5 TO 8 KTS LATER THIS
AFTERNOON/EVENING JUST AHEAD OF THE CFRONT.
AFTER THE CFROPA LATE TONIGHT AND EARLY SATURDAY...LLVL WINDS WILL
BLOW FROM 340-010 DEG...WITH SOME GUSTS INTO THE MID AND UPPER
TEENS BY LATE SAT MORNING. A PERIOD OF LOW STRATUS/STRATOCU
APPEARS LIKELY LATE TONIGHT THROUGH 14-16Z SAT /ESP ACROSS THE
NRN AND WRN MTNS OF PENN/.
LOW TEMPS EARLY SATURDAY WILL VARY FROM THE U30S NW TO LOWER 50S
IN THE SE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
CAN/T RULE OUT A FEW LINGERING SHOWERS LASTING THRU LATE SAT AM
ACROSS THE LOWER SUSQ VALLEY. THE MAIN FCST PROBLEM FOR LATER
SATURDAY MORNING WILL SURROUND THE EXTENT OF LOW CLOUDS...AND
TIMING OF THEIR DISSIPATION.
THE ARRIVAL OF HIGH PRESSURE AND DRIER NNW FLOW SHOULD BRING
MSUNNY SKIES TO THE ENTIRE AREA BY SAT AFTN. SUPERBLEND TEMPS
LOOKING SEASONABLE SAT...FROM THE U50S NW MTNS TO M-U60S SE
COUNTIES.
THE WIND WILL AVERAGE 10-15 KTS WITH SOME GUSTS IN THE UPPER TEENS
LIKELY CENTRAL AND WESTERN PENN. SUSTAINED AND PEAK GUSTS
NORTHERLY WIND GUSTS COULD BE 5-8 KTS HIGHER ACROSS THE EAST
WHERE LLVL P-GRADIENT IS THE TIGHTEST AHEAD OF HIGH PRESSURE OVER
THE GLAKES REGION. LATER SHIFTS MAY HAVE TO CONSIDER/COLLABORATE
WITH SURROUNDING WFOS A FIRE WEATHER WATCH OR RED FLAG WARNING FOR
SATURDAY SHOULD RAINFALL AMOUNTS BE LESS THAN CURRENTLY FCST.
HIGH PRESSURE WILL BECOME CENTERED OVER THE REGION SATURDAY NIGHT
WITH CLEAR SKIES...LOW PWATS AND NEARLY CALM AIR. INCLUDED PATCHY
FROST ACROSS THE MTNS NEAR THE I-80 CORRIDOR AND LARGER AREAS OF
FROST ACROSS THE NRN MTNS. HOWEVER...THIS AREA OF THE STATE IS
STILL OUTSIDE OF THE BEGINNING OF THE GROWING SEASON. A LOW PROB
FOR A FROST ADVISORY IS IN THE EAST/WEST SLIVER OF COUNTIES JUST
ALONG AND JUST SOUTH OF I-80 WHERE THE OFFICIAL START TO THE
GROWING SEASON WAS THURSDAY/APRIL 21ST.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
GUIDANCE HAS BEEN CONSISTENT IN SHOWING THE BROAD
TROUGH/RIDGE/TROUGH CONFIGURATION EXTENDING FROM THE GREAT BASIN
TO THE PLAINS INTO THE MID ATLANTIC REGION AT THE START OF THE
LONG TERM PERIOD TRANSITIONING TOWARD A MEAN WESTERN
TROUGH/BUILDING RIDGE IN THE EAST THRU NEXT WEEK. UNCERTAINTY HAS
ALSO DECREASED OVER THE POSITION OF AN EAST/WEST SFC FRONTAL
BOUNDARY AND LOW LEVEL BAROCLINIC ZONE WITH COLDER TEMPERATURES
STAYING WELL TO THE NORTH OF PA ALONG THE NRN TIER STATES/CANADIAN
BORDER.
THE WEEKEND AS A WHOLE LOOKS FAIR AND DRY WITH A RISK OF
FROST/FREEZE CONDITIONS SATURDAY NIGHT INTO SUNDAY MORNING. WAVES
OF LOW PRESSURE MOVG EWD ALONG WAVY SFC FRONTAL BOUNDARY PRESSING
SWD FROM THE LOWER LAKES/UPSTATE NY SHOULD BRING PERIODS OF RAIN
EARLY NEXT WEEK BUT CONFIDENCE IN EXACT TIMING OF GREATEST PCPN
RISK IS STILL BELOW AVERAGE AND COULD EASILY SHIFT +/- 12 HOURS.
MODEL CONSENSUS FAVORS A DRY PERIOD ON WEDNESDAY BEFORE RAIN PROBS
TREND HIGHER FROM WEST TO EAST INTO THE SECOND HALF OF NEXT WEEK.
ASIDE FROM A CHILLY SUNDAY MORNING...THE GLOBAL ENSEMBLE MEANS
ALONG WITH NATIONAL/REGIONAL BLENDS ALL SUPPORT ABOVE NORMAL TEMPS
THROUGH THE MEDIUM RANGE PERIOD.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
COLD FRONT WILL PUSH SLOWLY ACROSS THE REGION LATER TODAY AND
TONIGHT. AHEAD OF THAT...LLJET WILL SWING THROUGH THE SOUTHEASTERN
THIRD OF THE STATE...BRINGING A PLUME OF MOISTURE THROUGH EARLY
THIS AFTERNOON...THAT WILL SUPPORT A FEW AREA OF MAINLY LIGHT
SHOWERS AND BRING CIG REDUCTIONS MAINLY TO WESTERN HALF.
THE AREA OF DRYING AND MAINLY VFR...MID-LEVEL CLOUDS THAT
OCCURRED BEHIND THE DEPARTING LL JET OVER NRN MD AND SERN PENN
WILL TRANSITION TO AN INCREASING THREAT FOR SHOWERS OVER THE WRN
MTNS AFTER 20Z.
THE COLD FRONT AND APPROACHING UPPER LOW WILL BRING NUMEROUS
SHOWERS AND PERHAPS A FEW ISOLATED LATE TODAY/ THIS EVENING
/AND MAINLY OVERNIGHT IN THE SE/...ALONG WITH RESTRICTIONS
RETURNING TO THE WEST AND INTERMITTENT RESTRICTIONS TO THE EAST.
RESTRICTIONS CONTINUE OVER WESTERN AND CENTRAL MTNS INTO SAT AS
UPPER TROUGH PASSES THROUGH.
OUTLOOK...
SAT...AM LOW CIGS W MTNS.
SUN...NO SIG WX EXPECTED.
MON-TUE...PM SHRA DEVELOPING MONDAY AND CONTINUING INTO TUESDAY.
REDUCTIONS POSSIBLE...MAINLY NW PA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...FITZGERALD/GARTNER
AVIATION...LAMBERT/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
330 PM EDT FRI APR 22 2016
.SYNOPSIS...
A COLD FRONT ALONG THE SOUTH SHORE OF LAKE ERIE THIS AFTERNOON
WILL PUSH SLOWLY SOUTHEAST ACROSS PENNSYLVANIA LATE TODAY AND
TONIGHT. THIS FRONT WILL COMBINE WITH A COMPACT UPPER LOW HEADING
EAST FROM OHIO TO BRING AN INCREASING CHANCE FOR SHOWERS LATER
THIS AFTERNOON AND EVENING ACROSS CENTRAL AND WESTERN
PENNSYLVANIA...AND LATE TONIGHT OVER THE SOUTHEAST. HIGH PRESSURE
WILL BUILD INTO THE REGION THIS WEEKEND. ANOTHER COLD FRONT IS
LIKELY TO PUSH ACROSS THE AREA MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
A DISTINCT AREA OF LLVL RIDGING HELPED TO BRING MAINLY DRY
CONDITIONS ACROSS MUCH OF CENTRAL PENN TODAY BENEATH AN OVC LAYER
OF THICK ALTO CU AND ALTO/CIRROSTRATUS CLOUDS. AN AREA OF SHOWERS
LINKED TO THE NOSE OF A 30-40 KT SWRLY LLJ WAS SLIDING ACROSS OUR
EXTREME SERN COUNTIES ATTM...WHILE A SECOND AREA OF SCATTERED
SHOWERS /ASSOCIATED WITH THE LEFT EXIT REGION OF A SOUTHERLY UPPER
JETLET JUST AHEAD OF THE SFC COLD FRONT/ WAS AFFECTING THE NRN
MTNS AND WRN PLATEAU OF PENN..
MIXED LAYER CAPE WILL INCREASE TO 200-500 J/KG ACROSS SOUTHERN AND
WESTERN PARTS OF THE FCST AREA LATE THIS AFTERNOON AND
EVENING /WITH SOME POCKETS OF CAPE APPROACHING 1000 J/KG
POSSIBLE/. THIS MODEST INCREASE IN INSTAB AHEAD OF THE COLD FRONT
WILL SUPPORT THE DEVELOPMENT OF ISOLATED HEAVIER SHOWERS AND A
FEW LOW-TOPPED TSRA...MAINLY NEAR AND WEST OF RT 219 AND TO THE
SOUTH OF THE RT 22/322 CORRIDOR.
TEMPS AT 18Z ARE NEARING THEIR FORECAST HIGHS /SEVERAL DEG ABV
CLIMO/...IN THE LOWER TO MID 60S ACROSS THE NRN AND WRN MTNS...AND
UPPER 60S TO LOWER 70S ELSEWHERE ACROSS CENTRAL AND SERN PA.
AS THE COLD FRONT SLIDES SE ACROSS THE ALLEGHENIES AND INTO
CENTRAL PENN LATER THIS EVENING THROUGH ABOUT 06Z...THE TIMING
SHOULD COINCIDE NICELY WITH THE EWD PROGRESSION OF AN AREA OF
STRONG UPPER DIFFLUENCE/UVVEL JUST AHEAD OF THE COMPACT UPPER
TROUGH SEEN OVER OHIO LATE THIS AFTERNOON. HRRR AGREES WITH THIS
SCENARIO AND PAINTS OF FEW SMALL AREAS OF ENHANCED CONVECTION AND
QPF OVER THE SOUTHERN HALF TO TWO THIRDS OF THE CWA. ALTHOUGH A
FEW RUMBLES OF THUNDER CAN/T BE RULED OUT...SCATTERED MDT TO
BRIEFLY HEAVY SHRA WILL LIKELY BE THE DOMINANT FORM OF CONVECTION
THIS EVENING AND TONIGHT. ADDITIONAL RAINFALL RANGING FROM 1-2
TENTHS ACROSS THE REGION NORTH OF I-80...AND UP TO 3 TENTHS OF AN
INCH IN THE SOUTH STILL LOOKS IN GOOD SHAPE FORECAST-WISE BASED ON
THE PAST SEVERAL RUNS OF THE HRRR...THE LATEST SREF AND GEFS...AND
12Z OPER MODELS.
WINDS WILL BE VERY LIGHT AND VARIABLE IN DIRECTION TO START THE
AFTERNOON...THEN BECOME SOUTHWESTERLY AT 5 TO 8 KTS LATER THIS
AFTERNOON/EVENING JUST AHEAD OF THE CFRONT.
AFTER THE CFROPA LATE TONIGHT AND EARLY SATURDAY...LLVL WINDS WILL
BLOW FROM 340-010 DEG...WITH SOME GUSTS INTO THE MID AND UPPER
TEENS BY LATE SAT MORNING. A PERIOD OF LOW STRATUS/STRATOCU
APPEARS LIKELY LATE TONIGHT THROUGH 14-16Z SAT /ESP ACROSS THE
NRN AND WRN MTNS OF PENN/.
LOW TEMPS EARLY SATURDAY WILL VARY FROM THE U30S NW TO LOWER 50S
IN THE SE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
CAN/T RULE OUT A FEW LINGERING SHOWERS LASTING THRU LATE SAT AM
ACROSS THE LOWER SUSQ VALLEY. THE MAIN FCST PROBLEM FOR LATER
SATURDAY MORNING WILL SURROUND THE EXTENT OF LOW CLOUDS...AND
TIMING OF THEIR DISSIPATION.
THE ARRIVAL OF HIGH PRESSURE AND DRIER NNW FLOW SHOULD BRING
MSUNNY SKIES TO THE ENTIRE AREA BY SAT AFTN. SUPERBLEND TEMPS
LOOKING SEASONABLE SAT...FROM THE U50S NW MTNS TO M-U60S SE
COUNTIES.
THE WIND WILL AVERAGE 10-15 KTS WITH SOME GUSTS IN THE UPPER TEENS
LIKELY CENTRAL AND WESTERN PENN. SUSTAINED AND PEAK GUSTS
NORTHERLY WIND GUSTS COULD BE 5-8 KTS HIGHER ACROSS THE EAST
WHERE LLVL P-GRADIENT IS THE TIGHTEST AHEAD OF HIGH PRESSURE OVER
THE GLAKES REGION. LATER SHIFTS MAY HAVE TO CONSIDER/COLLABORATE
WITH SURROUNDING WFOS A FIRE WEATHER WATCH OR RED FLAG WARNING FOR
SATURDAY SHOULD RAINFALL AMOUNTS BE LESS THAN CURRENTLY FCST.
HIGH PRESSURE WILL BECOME CENTERED OVER THE REGION SATURDAY NIGHT
WITH CLEAR SKIES...LOW PWATS AND NEARLY CALM AIR. INCLUDED PATCHY
FROST ACROSS THE MTNS NEAR THE I-80 CORRIDOR AND LARGER AREAS OF
FROST ACROSS THE NRN MTNS. HOWEVER...THIS AREA OF THE STATE IS
STILL OUTSIDE OF THE BEGINNING OF THE GROWING SEASON. A LOW PROB
FOR A FROST ADVISORY IS IN THE EAST/WEST SLIVER OF COUNTIES JUST
ALONG AND JUST SOUTH OF I-80 WHERE THE OFFICIAL START TO THE
GROWING SEASON WAS THURSDAY/APRIL 21ST.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
GUIDANCE HAS BEEN CONSISTENT IN SHOWING THE BROAD
TROUGH/RIDGE/TROUGH CONFIGURATION EXTENDING FROM THE GREAT BASIN
TO THE PLAINS INTO THE MID ATLANTIC REGION AT THE START OF THE
LONG TERM PERIOD TRANSITIONING TOWARD A MEAN WESTERN
TROUGH/BUILDING RIDGE IN THE EAST THRU NEXT WEEK. UNCERTAINTY HAS
ALSO DECREASED OVER THE POSITION OF AN EAST/WEST SFC FRONTAL
BOUNDARY AND LOW LEVEL BAROCLINIC ZONE WITH COLDER TEMPERATURES
STAYING WELL TO THE NORTH OF PA ALONG THE NRN TIER STATES/CANADIAN
BORDER.
THE WEEKEND AS A WHOLE LOOKS FAIR AND DRY WITH A RISK OF
FROST/FREEZE CONDITIONS SATURDAY NIGHT INTO SUNDAY MORNING. WAVES
OF LOW PRESSURE MOVG EWD ALONG WAVY SFC FRONTAL BOUNDARY PRESSING
SWD FROM THE LOWER LAKES/UPSTATE NY SHOULD BRING PERIODS OF RAIN
EARLY NEXT WEEK BUT CONFIDENCE IN EXACT TIMING OF GREATEST PCPN
RISK IS STILL BELOW AVERAGE AND COULD EASILY SHIFT +/- 12 HOURS.
MODEL CONSENSUS FAVORS A DRY PERIOD ON WEDNESDAY BEFORE RAIN PROBS
TREND HIGHER FROM WEST TO EAST INTO THE SECOND HALF OF NEXT WEEK.
ASIDE FROM A CHILLY SUNDAY MORNING...THE GLOBAL ENSEMBLE MEANS
ALONG WITH NATIONAL/REGIONAL BLENDS ALL SUPPORT ABOVE NORMAL TEMPS
THROUGH THE MEDIUM RANGE PERIOD.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
COLD FRONT WILL PUSH SLOWLY ACROSS THE REGION LATER TODAY AND
TONIGHT. AHEAD OF THAT...LLJET WILL SWING THROUGH THE SOUTHEASTERN
THIRD OF THE STATE...BRINGING A PLUME OF MOISTURE THROUGH EARLY
THIS AFTERNOON...THAT WILL SUPPORT A FEW AREA OF MAINLY LIGHT
SHOWERS AND BRING CIG REDUCTIONS MAINLY TO WESTERN HALF.
THE AREA OF DRYING AND MAINLY VFR...MID-LEVEL CLOUDS THAT
OCCURRED BEHIND THE DEPARTING LL JET OVER NRN MD AND SERN PENN
WILL TRANSITION TO AN INCREASING THREAT FOR SHOWERS OVER THE WRN
MTNS AFTER 20Z.
THE COLD FRONT AND APPROACHING UPPER LOW WILL BRING NUMEROUS
SHOWERS AND PERHAPS A FEW ISOLATED LATE TODAY/ THIS EVENING
/AND MAINLY OVERNIGHT IN THE SE/...ALONG WITH RESTRICTIONS
RETURNING TO THE WEST AND INTERMITTENT RESTRICTIONS TO THE EAST.
RESTRICTIONS CONTINUE OVER WESTERN AND CENTRAL MTNS INTO SAT AS
UPPER TROUGH PASSES THROUGH.
OUTLOOK...
SAT...AM LOW CIGS W MTNS.
SUN...NO SIG WX EXPECTED.
MON-TUE...PM SHRA DEVELOPING MONDAY AND CONTINUING INTO TUESDAY.
REDUCTIONS POSSIBLE...MAINLY NW PA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...FITZGERALD/GARTNER
AVIATION...LAMBERT/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
253 PM EDT FRI APR 22 2016
.SYNOPSIS...
A COLD FRONT ALONG THE SOUTH SHORE OF LAKE ERIE THIS AFTERNOON
WILL PUSH SLOWLY SOUTHEAST ACROSS PENNSYLVANIA LATE TODAY AND
TONIGHT. THIS FRONT WILL COMBINE WITH A COMPACT UPPER LOW HEADING
EAST FROM OHIO TO BRING AN INCREASING CHANCE FOR SHOWERS LATER
THIS AFTERNOON AND EVENING ACROSS CENTRAL AND WESTERN
PENNSYLVANIA...AND LATE TONIGHT OVER THE SOUTHEAST. HIGH PRESSURE
WILL BUILD INTO THE REGION THIS WEEKEND. ANOTHER COLD FRONT IS
LIKELY TO PUSH ACROSS THE AREA MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
A DISTINCT AREA OF LLVL RIDGING HELPED TO BRING MAINLY DRY
CONDITIONS ACROSS MUCH OF CENTRAL PENN TODAY BENEATH AN OVC LAYER
OF THICK ALTO CU AND ALTO/CIRROSTRATUS CLOUDS. AN AREA OF SHOWERS
LINKED TO THE NOSE OF A 30-40 KT SWRLY LLJ WAS SLIDING ACROSS OUR
EXTREME SERN COUNTIES ATTM...WHILE A SECOND AREA OF SCATTERED
SHOWERS /ASSOCIATED WITH THE LEFT EXIT REGION OF A SOUTHERLY UPPER
JETLET JUST AHEAD OF THE SFC COLD FRONT/ WAS AFFECTING THE NRN
MTNS AND WRN PLATEAU OF PENN..
MIXED LAYER CAPE WILL INCREASE TO 200-500 J/KG ACROSS SOUTHERN AND
WESTERN PARTS OF THE FCST AREA LATE THIS AFTERNOON AND
EVENING /WITH SOME POCKETS OF CAPE APPROACHING 1000 J/KG
POSSIBLE/. THIS MODEST INCREASE IN INSTAB AHEAD OF THE COLD FRONT
WILL SUPPORT THE DEVELOPMENT OF ISOLATED HEAVIER SHOWERS AND A
FEW LOW-TOPPED TSRA...MAINLY NEAR AND WEST OF RT 219 AND TO THE
SOUTH OF THE RT 22/322 CORRIDOR.
TEMPS AT 18Z ARE NEARING THEIR FORECAST HIGHS /SEVERAL DEG ABV
CLIMO/...IN THE LOWER TO MID 60S ACROSS THE NRN AND WRN MTNS...AND
UPPER 60S TO LOWER 70S ELSEWHERE ACROSS CENTRAL AND SERN PA.
AS THE COLD FRONT SLIDES SE ACROSS THE ALLEGHENIES AND INTO
CENTRAL PENN LATER THIS EVENING THROUGH ABOUT 06Z...THE TIMING
SHOULD COINCIDE NICELY WITH THE EWD PROGRESSION OF AN AREA OF
STRONG UPPER DIFFLUENCE/UVVEL JUST AHEAD OF THE COMPACT UPPER
TROUGH SEEN OVER OHIO LATE THIS AFTERNOON. HRRR AGREES WITH THIS
SCENARIO AND PAINTS OF FEW SMALL AREAS OF ENHANCED CONVECTION AND
QPF OVER THE SOUTHERN HALF TO TWO THIRDS OF THE CWA. ALTHOUGH A
FEW RUMBLES OF THUNDER CAN/T BE RULED OUT...SCATTERED MDT TO
BRIEFLY HEAVY SHRA WILL LIKELY BE THE DOMINANT FORM OF CONVECTION
THIS EVENING AND TONIGHT. ADDITIONAL RAINFALL RANGING FROM 1-2
TENTHS ACROSS THE REGION NORTH OF I-80...AND UP TO 3 TENTHS OF AN
INCH IN THE SOUTH STILL LOOKS IN GOOD SHAPE FORECAST-WISE BASED ON
THE PAST SEVERAL RUNS OF THE HRRR...THE LATEST SREF AND GEFS...AND
12Z OPER MODELS.
WINDS WILL BE VERY LIGHT AND VARIABLE IN DIRECTION TO START THE
AFTERNOON...THEN BECOME SOUTHWESTERLY AT 5 TO 8 KTS LATER THIS
AFTERNOON/EVENING JUST AHEAD OF THE CFRONT.
AFTER THE CFROPA LATE TONIGHT AND EARLY SATURDAY...LLVL WINDS WILL
BLOW FROM 340-010 DEG...WITH SOME GUSTS INTO THE MID AND UPPER
TEENS BY LATE SAT MORNING. A PERIOD OF LOW STRATUS/STRATOCU
APPEARS LIKELY LATE TONIGHT THROUGH 14-16Z SAT /ESP ACROSS THE
NRN AND WRN MTNS OF PENN/.
LOW TEMPS EARLY SATURDAY WILL VARY FROM THE U30S NW TO LOWER 50S
IN THE SE.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
CAN/T RULE OUT A FEW LINGERING SHOWERS LASTING THRU LATE SAT AM
ACROSS THE LOWER SUSQ VALLEY. THE MAIN FCST PROBLEM FOR LATER
SATURDAY MORNING WILL SURROUND THE EXTENT OF LOW CLOUDS...AND
TIMING OF THEIR DISSIPATION.
THE ARRIVAL OF HIGH PRESSURE AND DRIER NNW FLOW SHOULD BRING
MSUNNY SKIES TO THE ENTIRE AREA BY SAT AFTN. SUPERBLEND TEMPS
LOOKING SEASONABLE SAT...FROM THE U50S NW MTNS TO M-U60S SE
COUNTIES.
THE WIND WILL AVERAGE 10-15 KTS WITH SOME GUSTS IN THE UPPER TEENS
LIKELY CENTRAL AND WESTERN PENN. SUSTAINED AND PEAK GUSTS
NORTHERLY WIND GUSTS COULD BE 5-8 KTS HIGHER ACROSS THE EAST
WHERE LLVL P-GRADIENT IS THE TIGHTEST AHEAD OF HIGH PRESSURE OVER
THE GLAKES REGION. LATER SHIFTS MAY HAVE TO CONSIDER/COLLABORATE
WITH SURROUNDING WFOS A FIRE WEATHER WATCH OR RED FLAG WARNING FOR
SATURDAY SHOULD RAINFALL AMOUNTS BE LESS THAN CURRENTLY FCST.
HIGH PRESSURE WILL BECOME CENTERED OVER THE REGION SATURDAY NIGHT
WITH CLEAR SKIES...LOW PWATS AND NEARLY CALM AIR. INCLUDED PATCHY
FROST ACROSS THE MTNS NEAR THE I-80 CORRIDOR AND LARGER AREAS OF
FROST ACROSS THE NRN MTNS. HOWEVER...THIS AREA OF THE STATE IS
STILL OUTSIDE OF THE BEGINNING OF THE GROWING SEASON. A LOW PROB
FOR A FROST ADVISORY IS IN THE EAST/WEST SLIVER OF COUNTIES JUST
ALONG AND JUST SOUTH OF I-80 WHERE THE OFFICIAL START TO THE
GROWING SEASON WAS THURSDAY/APRIL 21ST.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
GUIDANCE HAS COME INTO MUCH BETTER AGREEMENT IN THE PATTERN
VERSUS PREVIOUS DAYS...SHOWING A MIGRATION FROM A BROAD
TROUGH/RIDGE/TROUGH CONFIGURATION EXTENDING FROM THE GREAT BASIN
TO THE PLAINS INTO THE MID ATLANTIC REGION AT THE START OF THE
PERIOD...TOWARD A MEAN WESTERN TROUGH/BUILDING RIDGE IN THE EAST
BY NEXT THU AS THE STRONG HIGH LATITUDE BLOCKING WEAKENS OVER
GREENLAND/EASTERN CANADA. UNCERTAINTY HAS ALSO DECREASED OVER THE
POSITION OF AN EAST/WEST SFC FRONTAL BOUNDARY AND LOW LEVEL
BAROCLINIC ZONE WITH COLDER TEMPERATURES STAYING WELL TO THE NORTH
OF PA ALONG THE NRN TIER STATES/CANADIAN BORDER.
THE WEEKEND AS A WHOLE LOOKS FAIR AND DRY WITH A RISK OF
FROST/FREEZE CONDITIONS SATURDAY NIGHT INTO SUNDAY MORNING. WAVES
OF LOW PRESSURE MOVG EWD ALONG WAVY SFC FRONTAL BOUNDARY PRESSING
SWD FROM THE LOWER LAKES/UPSTATE NY SHOULD BRING PERIODS OF RAIN
EARLY NEXT WEEK BUT CONFIDENCE IN EXACT TIMING OF GREATEST PCPN
RISK IS STILL BELOW AVERAGE AND COULD EASILY SHIFT +/- 12 HOURS.
MODEL CONSENSUS FAVORS A DRY PERIOD ON WEDNESDAY BEFORE RAIN PROBS
TREND HIGHER FROM WEST TO EAST INTO THE SECOND HALF OF NEXT WEEK.
ASIDE FROM A CHILLY SUNDAY MORNING...THE GLOBAL ENSEMBLE MEANS
ALONG WITH NATIONAL/REGIONAL BLENDS ALL SUPPORT ABOVE NORMAL TEMPS
THROUGH THE MEDIUM RANGE PERIOD.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
COLD FRONT WILL PUSH SLOWLY ACROSS THE REGION LATER TODAY AND
TONIGHT. AHEAD OF THAT...LLJET WILL SWING THROUGH THE SOUTHEASTERN
THIRD OF THE STATE...BRINGING A PLUME OF MOISTURE THROUGH EARLY
THIS AFTERNOON...THAT WILL SUPPORT A FEW AREA OF MAINLY LIGHT
SHOWERS AND BRING CIG REDUCTIONS MAINLY TO WESTERN HALF.
THE AREA OF DRYING AND MAINLY VFR...MID-LEVEL CLOUDS THAT
OCCURRED BEHIND THE DEPARTING LL JET OVER NRN MD AND SERN PENN
WILL TRANSITION TO AN INCREASING THREAT FOR SHOWERS OVER THE WRN
MTNS AFTER 20Z.
THE COLD FRONT AND APPROACHING UPPER LOW WILL BRING NUMEROUS
SHOWERS AND PERHAPS A FEW ISOLATED LATE TODAY/ THIS EVENING
/AND MAINLY OVERNIGHT IN THE SE/...ALONG WITH RESTRICTIONS
RETURNING TO THE WEST AND INTERMITTENT RESTRICTIONS TO THE EAST.
RESTRICTIONS CONTINUE OVER WESTERN AND CENTRAL MTNS INTO SAT AS
UPPER TROUGH PASSES THROUGH.
OUTLOOK...
SAT...AM LOW CIGS W MTNS.
SUN...NO SIG WX EXPECTED.
MON-TUE...PM SHRA DEVELOPING MONDAY AND CONTINUING INTO TUESDAY.
REDUCTIONS POSSIBLE...MAINLY NW PA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...FITZGERALD/STEINBUGL
AVIATION...LAMBERT/RXR
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
202 PM EDT FRI APR 22 2016
.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL APPROACH THE REGION FROM THE WEST
TODAY BEFORE PASSING THROUGH THE AREA OVERNIGHT INTO EARLY
SATURDAY. HIGH PRESSURE SHOULD BUILD IN BEHIND THIS SYSTEM LATER
SATURDAY AND REMAIN OVER THE REGION THROUGH MONDAY. THE NEXT COLD
FRONT WILL SLIDE SOUTH THROUGH THE AREA ON TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 240 AM EDT FRIDAY...
WEAKENING UPPER LOW AND ITS ASSOCIATED SURFACE COLD FRONT WILL FINALLY
PUSH EAST TODAY REACHING THE BLUE RIDGE THIS EVENING BEFORE THE FRONT
SLIDES TOWARD THE COAST TOWARD DAYBREAK SATURDAY. QUICK INCREASE IN
DEEPER MOISTURE PER SPIKE IN PWATS TO JUST BELOW 1.5 INCHES SHOULD
BRING A BIT MORE IN THE WAY OF MUCH NEEDED RAINFALL INTO THIS
EVENING. HOWEVER JUST HOW THINGS UNFOLD AND THE DEGREE OF DEEPER
CONVECTION REMAINS UNCERTAIN...ESPCLY GIVEN POTENTIAL FOR MULTIPLE
BANDS AHEAD OF THE FRONT DESPITE LACK OF DEEP INSTABILITY PER
LIMITED HEATING. LATEST MODELS DEPICT THIS WELL WITH AN INITIAL
BAND OF SHOWERS REDEVELOPING OVER THE WEST THIS MORNING ALONG AN
AXIS OF DIFFLUENCE AND DRIVEN BY WEAK SHORTWAVE ENERGY JUST AHEAD
OF THE ACTUAL FRONT. HRRR HAS THIS AXIS OF SHOWERS ALL THE WAY OUT
TO THE BLUE RIDGE THIS MORNING WHICH LOOKS OVERDONE...ALTHOUGH
OTHER SOLUTIONS VARY ON TIMING BUT TEND TO SUPPORT THIS SCENARIO.
THEREFORE TRENDED HIGHER POPS IN THAT DIRECTION EARLY ON.
ONCE THIS BAND SPREADS EAST...GUIDANCE SHOWS SOME INCREASE IN
INSTABILITY PIEDMONT ALONG ITS LEADING EDGE...AND THEN OUT WEST
AHEAD OF ANOTHER BAND OR TWO JUST AHEAD OF THE FRONT. HOWEVER
FORECAST CAPES/BULK SHEAR NOT IMPRESSIVE ESPCLY WITH INSOLATION
TEMPERED BY CLOUDS/SHRA UNLESS MODELS ARE OVERDONE AND MORE
HEATING IS REALIZED. FOR NOW WILL TREND TOWARD WESTERN SHOWER
COVERAGE EARLY...THEN HAVE MORE WIDESPREAD SHOWERS PER LIKELY OR
BETTER POPS THIS AFTERNOON ALL SECTIONS...INCLUDING MORE THUNDER
MENTION FAR WEST AND ESPCLY SOUTHEAST WHERE SHOULD GET A LITTLE
MORE HEATING. OTRW KEEPING MAINLY ISOLATED THUNDER MENTION
ELSEWHERE WHICH MAY BE GENEROUS. TRIMMED HIGH TEMPS BACK A CAT OR
SO ESPCLY WEST WHERE COULD GET STUCK IN THE LOW/MID 60S WITH ONLY
THE EAST PERHAPS 67-72 OR WARMER.
CORRIDOR OF BETTER LIFT SHOULD SPILL EAST OF THE AREA AHEAD OF THE
FRONT THIS EVENING WITH THE OPENING 5H LOW LIKELY KEEPING SOME SHOWERS
AND ISOLATED TSRA GOING MAINLY NORTH/NW ESPCLY BEFORE MIDNIGHT. OTRW
FLOW TURNING NW BEHIND THE BOUNDARY LOOKS TO CUT INTO LINGERING
SHRA ELSEWHERE...SO STEADILY REDUCING POPS AFTER 00Z WITH ONLY
20/30 POPS REMAINING FOR THE MOST PART AFTER MIDNIGHT. TOTAL QPF
LOOKS TO BE A BIT MORE PENDING COVERAGE WITHIN BANDS PERHAPS
RESULTING IN .30 TO .75 WITH THE HIGHEST AMOUNTS OVER THE SOUTH
AND WEST AT THIS POINT. COOL ADVECTION BEHIND THE FRONT RATHER
WEAK OVERNIGHT AND WITH LINGERING CLOUDS EXPECT LOWS TO REMAIN
MOSTLY IN THE UPPER 40S TO MID 50S.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 245 AM EDT FRIDAY...
AN UPPER LOW WILL DROP SOUTHEAST ACROSS THE REGION ON SATURDAY WITH
ISOLATED TO SCATTERED SHOWERS. HIGH TEMPERATURES ON SATURDAY WILL
RANGE FROM THE UPPER 50S IN THE MOUNTAINS TO THE MID 70S IN THE
PIEDMONT.
THE UPPER TROUGH WILL PUSH OUT INTO THE ATLANTIC OCEAN SATURDAY
EVENING. THIS WILL ALLOW HIGH PRESSURE TO BUILD INTO OUR REGION
SATURDAY NIGHT. LOW TEMPERATURES SATURDAY NIGHT WILL VARY FROM
AROUND 40 IN THE NORTHWEST MOUNTAINS TO THE LOWER 50S IN THE
PIEDMONT.
A 1020 MB SURFACE HIGH PRESSURE WILL BUILD ACROSS OUR AREA SUNDAY.
HIGH TEMPERATURES WILL WARM INTO THE UPPER 60S IN THE WEST TO THE
UPPER 70S IN THE EAST. UNDER MOSTLY CLEAR SKIES...SUNDAY NIGHT LOW
TEMPERATURES WILL DROP INTO THE UPPER 40S TO LOWER 50S. HIGH
PRESSURE WILL REMAINS JUST OF THE NORTH CAROLINA COAST MONDAY INTO
MONDAY NIGHT. IT WILL BE A WARM START TO THE WORKWEEK WITH HIGHS
MONDAY FROM THE MID 70S IN THE MOUNTAINS TO THE LOWER 80S IN THE
PIEDMONT. LOW TEMPERATURES MONDAY NIGHT WILL BE MILD WITH READINGS
GENERALLY IN THE MID 50S TO AROUND 60 DEGREES.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 245 AM EDT FRIDAY...
GUIDANCE OFFERS SOLUTIONS OF A COLD FRONT APPROACHING AND CROSSING
THE AREA TUESDAY INTO WEDNESDAY. HOWEVER...TIMING VARIES BETWEEN THE
GFS AND ECMWF...ALONG WITH THE EXTENT PRECIPITATION WILL REACH AND
PERSIST INTO THE FORECAST REGION.
THE UNCERTAINTY OF THE ABOVE EVENT...TIES INTO THE EVEN GREATER
UNCERTAINTY OF THE NEXT EVENT. THE COLD FRONT IS EXPECTED TO STALL
EITHER OVER...OR SOUTH OF...THE REGION FOR A BRIEF PERIOD OF TIME.
AN APPROACHING UPPER LOW/TROUGH WILL HELP SWING LOW LEVEL WINDS TO
THE SOUTHWEST WEDNESDAY INTO THURSDAY AND LIFT THE STALLED FRONT
BACK NORTH AS A WARM FRONT. AGAIN...WITH EACH SOLUTION OFFERING
DIFFERENCES IN TIMING...PRECIPITATION AMOUNTS AND EXTENT OF THE
PRECIPITATION.
OUR LATEST FORECAST WILL REFLECT A CONSENSUS OF THESE AND OTHER
SOLUTIONS BY WEIGHING HEAVILY ON THE SUPERBLEND SOLUTION. THIS
SCENARIO OFFERS A SLIGHTLY SLOWER ARRIVAL TIME OF THE PRECIPITATION
MONDAY NIGHT INTO TUESDAY...LITTLE CHANGE TO THE PRIOR WEDNESDAY
FORECAST...AND SCATTERED SHOWERS ACROSS THE AREA ON THURSDAY.
INSTABILITY LOOKS STRONG ENOUGH FOR AT LEAST ISOLATED THUNDERSTORMS
TUESDAY...WEDNESDAY...AND THURSDAY AFTERNOON.
TEMPERATURES DURING THIS PORTION OF THE FORECAST WILL TREND MILDER
THROUGH TUESDAY...AND THEN SLIGHTLY COOLER THROUGH THURSDAY.
READINGS WILL BE AROUND TEN DEGREES ABOVE NORMAL FOR THIS TIME OF
YEAR.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 150 PM EDT FRIDAY...
MULTIPLE BANDS OF SHOWERS AND ISOLATED THUNDERSTORMS WILL CROSS
SOUTHWEST VIRGINIA...SOUTHEAST WEST VIRGINIA AND NORTHWEST NORTH
CAROLINA THIS AFTERNOON AND EVENING AHEAD OF A COLD FRONT.
MODERATE TO HEAVY RAIN WILL PRODUCE MVFR VISIBILITIES. CEILINGS
WERE WIDELY VARIABLE...RANGING FROM VFR TO IFR.
NCAR ENSEMBLE AND GEFS FORECAST...AS WELL AS OTHER MODELS WERE
CONSISTENT ON TIMING...WITH A BULK OF THE PRECIPITATION MOVING
EAST OF KDAN AND KLYH AROUND MIDNIGHT. ONCE THE PRECIPITATION
ENDS...HIGH CONFIDENCE OF FOG AND STRATUS OVERNIGHT.
WINDS TURN TO THE NORTHWEST THEN NORTH BEHIND THE COLD FRONT
THAT CROSSES THROUGH THE REGION TONIGHT. THE DOWNSLOPE WIND AND
ARRIVAL OF A DRIER AIRMASS WILL RESULT IN CLEARING ON THE LEE SIDE
OF THE BLUE RIDGE SATURDAY MORNING. MEDIUM TO HIGH CONFIDENCE THAT
KROA WILL ONLY HAVE SCATTERED CLOUDS LEFT BY THE 18Z END OF THE
TAF FORECAST PERIOD. CLOUDS ASSOCIATED WITH THE UPPER LOW MAY
LINGER IN KLYH AND KDAN LONGER ON SATURDAY. CONFIDENCE ON WHEN
CLEARING WILL OCCUR IS NOT AS HIGH FOR THESE SITES. IN THE
MOUNTAINS...LOWER CLOUDS WILL LINGER WELL INTO THE AFTERNOON.
EXTENDED AVIATION DISCUSSION...
WEAK HIGH PRESSURE FOLLOWS SATURDAY NIGHT INTO EARLY NEXT WEEK.
HOWEVER SOME LOWER CIGS MIGHT REDEVELOP ACROSS THE MOUNTAINS BY
SUNDAY AS LIGHT EASTERLY FLOW SETS UP UNDER ANOTHER WEAK WEDGE
WHICH SHOULD FADE BY EARLY NEXT WEEK. THE NEXT WEAK BACKDOOR COLD
FRONT MAY BRING A BAND OF SHOWERS ALONG WITH MOUNTAIN SUB-VFR ON
TUESDAY AND WEDNESDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...KK
LONG TERM...DS/KK
AVIATION...AMS/JH
AREA FORECAST DISCUSSION
NWS SEATTLE WA
900 AM PDT FRI APR 22 2016
.SYNOPSIS...AN UPPER LOW WILL BRING SHOWERS TODAY. AFTER A DRIER
PERIOD EARLY SATURDAY...ANOTHER SYSTEM WILL BRING SHOWERS LATER
SATURDAY AND SUNDAY. A DRYING TREND WILL FOLLOW NEXT WEEK.
&&
.SHORT TERM...SHOWERS OVER NW OREGON AND SW WA WILL SPREAD NORTH
BY AFTERNOON. THE UPPER LOW CENTERED OFF THE NORTH CALIF COAST
WILL MOVE TO SRN IDAHO BY MIDDAY SATURDAY AND SHOWER ACTIVITY
SHOULD DECREASE AS THE LOW DEPARTS. A NEW UPPER TROUGH WILL BRING
AN INCREASING CHANCE OF SHOWERS AGAIN AROUND SATURDAY EVENING.
THAT UPPER TROUGH WILLS SAG INTO THE GREAT BASIN THROUGH MONDAY
WITH SHOWERS DECREASING AGAIN OVER WRN WA AS THAT LOW DEPARTS.
.LONG TERM...A WEAK UPPER RIDGE WILL MOVE OVER THE AREA ON
TUESDAY SO THAT SHOULD BE A DRY DAY. A SPLITTING FRONT WILL FALL
APART JUST OFFSHORE ON WEDNESDAY WITH THE BULK OF THAT PRECIP
HEADING INTO NRN CALIF. MODEL SOLUTIONS DIVERGE ON THURSDAY.
THE GFS HAS ANOTHER UPPER LOW BRUSH THE AREA WITH SOME SHOWERS.
THE ECMWF HAS A RIDGE FOR DRY WEATHER.
&&
.AVIATION...AN UPPER LEVEL LOW OVER THE PAC NW WILL MAINTAIN SHOWERS
ACROSS WESTERN WA TODAY. THE AIR MASS IS MOIST WITH SOUTHERLY FLOW
ALOFT. THE HIGHEST INSTABILITY IS OVER THE CASCADES THIS AFTERNOON
WITH ISOLATED THUNDERSTORMS POSSIBLE. LOW LEVEL ONSHORE FLOW WILL
INCREASE TONIGHT WITH MVFR CIGS LIKELY. 33
KSEA...SHOWERS IN THE VICINITY TODAY. SOUTH FLOW AT THE SURFACE.
CIGS LOWERING TONIGHT WITH MVFR CONDITIONS. 33
&&
.MARINE...WEAK HIGH PRESSURE ALONG THE COAST WILL MAINTAIN ONSHORE
FLOW ACROSS WESTERN WA TODAY. WEST WINDS WILL INCREASE THOUGH THE
STRAIT OF JUAN DE FUCA THIS AFTERNOON - A SMALL CRAFT ADVISORY
REMAINS IN EFFECT. ONSHORE FLOW WILL INCREASE ON SATURDAY AS A COLD
FRONT MOVES INLAND. ONSHORE FLOW WILL CONTINUE THROUGH EARLY NEXT
WEAK WITH HIGH PRESSURE OVER THE NE PAC. THE NEXT FRONT WILL
ARRIVE TUESDAY NIGHT OR WEDNESDAY. 33
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO MIDNIGHT PDT
TONIGHT FOR CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA-EAST
ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.
&&
$$
WWW.WEATHER.GOV/SEATTLE
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
Area Forecast Discussion
National Weather Service Spokane WA
1104 AM PDT FRI APR 22 2016
.SYNOPSIS...
A strong upper level low and associated cold front will push into
the region today bringing a chance showers with thunderstorms
possible this afternoon and evening. A few of the thunderstorms
will be capable of producing hail and gusty winds. As the low
dives into southern Idaho late tonight, it will shift the focus
for precipitation across southeast Washington and the southern
Idaho Panhandle. This precipitation could be locally heavy at
times with possible mounain snow into Saturday morning. The
threat of showers will then continue through the rest of the
weekend and into early next week, especially for the Idaho
panhandle. Temperatures will be considerably cooler than what
what was experienced over the past several days.
&&
.DISCUSSION...
First band of convection is sliding northward of Spokane across
northeast Washington and across the Panhandle with mainly light
precipitation. Winds veer to the south-southwest behind this band
and expect partial clearing. This will allos the boundary layer to
heat up and instability increase. May see some surface based
convection bubble up by mid afternoon, but it looks to be
isolated. The HRRR shows the best chances across the Cascade
crest, the Blues and across the southern Panhandle. This
convective activity will spread northward into the evening hours
with occasional lightning strikes, brief downpours, gusty winds
and possibly small hail. The arrival of an upper level disturbance
late tonight will bring a more widespread area of showers across
the southeast portion of the forecast area. /rfox.
&&
.AVIATION...
12Z TAFS: Light showers with mid level CIGs will be found north
and east of KGEG through early afternoon. The next round of
convection will be surface based, with the best instability after
21z from KOMK-KGEG-KLWS with a chance of thunderstorms, gusty
winds and possibly small hail. The instability will decrease
after 03z, but a band of light showers will move up from the south
after 08z reaching KLWS and KPUW toward KCOE through the early
morning hours. Little thunderstorm threat expected in KEAT & KMWH,
and winds will veer to the west to northwest by early evening.
/rfox.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 72 47 61 43 57 40 / 30 50 30 20 60 10
Coeur d`Alene 72 45 58 42 57 39 / 30 70 80 40 50 10
Pullman 70 42 57 41 55 37 / 40 90 90 20 40 20
Lewiston 76 48 60 45 62 42 / 50 90 100 20 40 30
Colville 74 45 68 42 60 39 / 40 60 40 50 60 30
Sandpoint 70 42 58 40 55 36 / 40 70 60 60 50 10
Kellogg 72 41 53 39 54 36 / 60 80 100 50 60 30
Moses Lake 76 45 71 44 66 40 / 20 30 10 10 40 10
Wenatchee 73 48 68 47 63 43 / 20 20 10 20 50 20
Omak 74 46 72 44 62 41 / 30 20 10 20 60 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$