Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/18/15
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
102 PM EDT WED SEP 16 2015
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN ACROSS THE REGION THROUGH THURSDAY
BEFORE MOVING EASTWARD FRIDAY AND SATURDAY. A WEAK COLD FRONT
WILL CROSS AREA SUNDAY THROUGH SUNDAY NIGHT. HIGH PRESSURE WILL
BUILD ACROSS THE NORTHEASTERN UNITED STATES FOR THE EARLY PART OF
NEXT WEEK, WITH SOME MOISTURE POTENTIALLY MOVING UP FROM THE SOUTH
ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
12Z SOUNDINGS AND LOOKING AT THE UPPER AIR ANALYSES STILL SHOW
NO BIG CHANGES TO ONGOING FORECAST FOR MAX TEMPS. RELATIVELY
WARMER POCKET AT 925MB AND 850MB SURROUNDING THE NYC METRO
AREA. TEMPERATURES ARE RISING SLIGHTLY AHEAD OF SCHEDULE, SO DID
SOME NEAR NEAR TERM ADJUSTMENTS. LITERALLY SLIGHTLY STRONGER
SEA/BAY BREEZE DEPICTED ON LAST COUPLE OF HRRR RUNS, BUT OVERALL
NOT MUCH CHANGE FROM CURRENT FORECAST.
550 AM: RAISING TEMPS 1F TO GET PHL SOMERVILLE MORRISTOWN TO
AROUND 88 THIS AFTN. 06Z GFS HAD A LARGE AREA OF 2M TEMPS AROUND
85 AT 18Z. 850 TEMPS 14-15C.
TODAY...THE REMAINING THIN CIRRUS NEAR 30000 FT SHOULD BE THE ONLY
CLOUDS WE SEE TODAY AND THE SUN SHOULD EASILY SHINE THROUGH. THIS
AFTERNOON THERE SHOULD BE LESS CIRRUS THAN WHATEVER OCCURS THIS
MORNING. CALL IT MOSTLY SUNNY OR SUNNY BUT PROBABLY NOT QUITE AS
BRIGHT AS YESTERDAY.
GFS HAS BEEN BEST AT DEPICTING THIS 200MB RH IN ITS TSECTION
PROFILES. PLAN VIEW OF THE 200MB RH IN THE GFS20 3HLY DATA SHOWS
THIS CLOUDINESS SEEMINGLY GENERATED BY A RRQ OF 50 KT 200MB SPEED
MAX MOVING SE OF CAPE COD THIS MORNING AND THE LF QUAD OF THE
DIXIE SHORT WAVE SPEED MAX THAT INTENSIFIES WITH TIME AS THAT
SPEED MAX MOVES NE THROUGH THE CAROLINAS TODAY. THE BACK EDGE OF
THE CIRRUS SPREADS EWD INTO E PA NEAR 00Z/17 TONIGHT.
BOUNDARY LAYER TEMPS ARE WARMING AND MODEL GUIDANCE INDICATES A
GENERAL LIGHT WESTERLY WIND THOUGH AFTERNOON SEABREEZES WILL
BECOME COMMON. USED THE WARMER 00Z/16 GFS MOS GUIDANCE AS THE
PRIMARY TEMP GUIDANCE, OTRW A 50/50 BLEND OF THE 00Z/16 GFS/NAM
FOR ALL OTHER ELEMENTS.
RECENT USE OF GUIDANCE ON MOSTLY SUNNY DAYS HAS SHOWN MAX`S TO
VERIFY 18Z 2M TEMPS +5 FOR BOTH THE ECMWF AND NAM AND PLUS 3F FOR
THE SEEMINGLY RECENTLY IMPROVED 18Z 2M TEMP FCSTS OF THE GFS. GFS
2M TEMP FCST FOR PHL IS ABOUT 85... NOT IMPOSSIBLE TO SEE A FEW
89, 90F READINGS IN THE I-95 CORRIDOR THIS AFTN FROM KPHL NNEWD
TO NEAR KMMU. NAM BL TEMP MAX`S OUT AT 26C NEAR 21Z.
MAX TEMPS GENERALLY ABOUT 10F ABOVE NORMAL.
HIGH CONFIDENCE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
CALM AND CLEAR OR MOSTLY CLEAR WITH ANY LEFTOVER 200MB CIRRUS EDGING
SEWD ..THE BACK EDGE ACROSS S DE AND CAPE MAY NJ AT 12Z THU.
GENERALLY EXCELLENT RADIATING CONDITIONS. PATCHY FOG POSSIBLE
AFTER 04Z IN SOME OF THE COUNTRYSIDE. USED THE LESS PROLIFIC
GENERATING UPS CROSSOVER TOOL TONIGHT AND BASICALLY THE SAME AREA
AS WE HAD IT POSTED THIS MORNING.
ITS POSSIBLE THERE WILL BE SOME FOG IN SE NJ LATE TONIGHT BUT FOR
NOW FAVORED THE MORE CONSERVATIVE PREDICTOR IN THIS DRY AND WARM
BOUNDARY LAYER.
50 50 BLENDED 00Z/16 NAM/GFS MOS GUIDANCE.
NEAR NORMAL MIN TEMPS.
HIGH CONFIDENCE.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL BE THE DOMINANT FEATURE AT THE START OF THE
EXTENDED PD AND EXPECT OUR BRILLIANT STRETCH OF WX TO CONTINUE
INTO THE FIRST PART OF THE WEEKEND.
A LARGE AREA OF HIGH PRES WILL REMAIN OVER THE AREA ON THU, BEFORE
MOVG EWD ON FRI AND SAT. THIS HIGH WILL KEEP US DRY, WITH PLEASANT
TEMPS AND A MAINLY CLEAR SKY.
LOW PRES IN HUDSON BAY WILL MOVE EWD AND AND ANOTHER AREA OF LOW
PRES IS EXPECTED TO FORM ALG THE ATTENDANT CDFNT NR THE GRTLKS ON
SAT. HOWEVER, THIS LOW IS ALSO EXPECTED TO MOVE NEWD AND THE
LATEST DATA INDICATES BY THE TIME THE CDFNT REACHES OUR REGION ON
SUN, IT WILL HAVE LITTLE MOISTURE WITH IT. SO THE NEXT CHC OF ANY
RAIN WILL BE LATER ON SUN, AND IT MAY NOT BE MUCH OF A CHC AT ALL.
BEHIND THE CFP, HIGH PRES WILL BUILD TO OUR N FOR MON, KEEPING
MONDAY DRY, BUT HERE IS WHERE THINGS START TO GET A LITTLE
INTERESTING.
ALL OF THE GUID WANTS TO DEVELOP SOME SORT OF LOW OFF THE SERN
CONUS CST AND BRING THE MOISTURE NWD ON TUE. THE GFS IS FURTHER S
WITH THE AFOREMENTIONED HIGH AND KEEPS THE MOISTURE LIGHTER AND
MAINLY OVER SRN PORTIONS OF THE AREA.
ON THE OTHER HAND, THE ECMWF IS FURTHER N WITH THE HIGH (CENTERED
IN QUEBEC) AND BRINGS THE MOISTURE FURTHER N AND IS HEAVIER WITH
IT.
AT THIS STAGE NOT SURE WHICH ONE WILL BE CORRECT, OR IF THE TRUTH
WILL LIE SOMEWHERE IN THE MIDDLE, AND THIS IS A FAIRLY LARGE
CHANGE, ESPECIALLY FOR THE ECMWF. WOULD LIKE TO SEE SOME RUN-TO-
RUN CONTINUITY BEFORE MAKING MAJOR CHANGES TO THE FCST. HOWEVER, A
WETTER SIGNAL IS THERE, SO HAVE AT LEAST ADDED SOME LOW POPS.
ALSO, DUE TO THE POSN OF THE HIGH, THERE WILL BE A FAIRLY
PRONOUNCED NELY FLOW WHICH WILL KEEP THINGS RATHER CLOUDY
REGARDLESS OF PRECIP OR NOT, SO IT CERTAINLY DOES NOT LOOK AS NICE
AS THIS WEEK.
TEMPS WILL START OFF ABV NRML, WITH THE WARMEST DAY LIKELY BEING
THU AND THEN DECREASE EACH DAY WITH MON AND TUE BEING COOLEST IN
THE CLOUDS AND NELY FLOW BEHIND THE CDFNT.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
18Z TAFS VFR EXCEPT FOR SOME MVFR, POSSIBLY IFR, CONDITIONS
DURING EARLY THURSDAY MORNING AT MORE RURAL TERMINALS AND
AIRPORTS.
THIS AFTERNOON...VFR. SOME THIN CIRRUS. LIGHT AND VARIABLE WINDS
MAINLY STEERED BY LOCAL EFFECTS. A WEAK SEA BREEZE FRONT SHOULD
WORK ITS WAY ACROSS CENTRAL AND SOUTHERN NEW JERSEY AND LIKELY
DISSIPATE BEFORE REACHING THE DELAWARE RIVER EARLY THIS EVENING.
SOUTH TO SOUTHEAST WINDS BEHIND THE SEA BREEZE FRONT SHOULD STILL
BE LESS THAN 10 KNOTS.
THIS EVENING...CLEAR WITH LIGHT AND VARIABLE WINDS.
OVERNIGHT...CLEAR. SOME PATCHY FOG SHOULD FORM. WE USED THE
OBSERVATIONS THIS MORNING AS A BASIS FOR INCLUSION AND EXPANDED
DURATION BY AN HOUR OR TWO. SOME BRIEF IFR OR LOCAL IFR AT MORE
RURAL AIRPORTS POSSIBLE.
THURSDAY...VFR WITH SOME MORE CIRRUS. A SLIGHTLY STRONGER
SOUTHWEST (SOUTHEAST BEHIND SEA BREEZE FRONT) FLOW EXPECTED AS THE
HIGH PRESSURE SYSTEM MOVES OFFSHORE.
OUTLOOK...
THU NIGHT THROUGH SAT...MAINLY VFR CONDS EXPECTED. PATCHY FOG
PSBL FRI AND SAT AM, ESPECIALLY AT THE MORE RURAL TERMINALS. WINDS
WILL REMAIN LIGHT THROUGH THE WEEK, GENERALLY AT OR BELOW 10
KNOTS, OUT OF THE S OR SW. HIGH CONFIDENCE.
SUN...MAINLY VFR CONDITIONS EXPECTED. MVFR POSSIBLE IN LOW CHC
SHRA WITH A WEAK CFP. WEST TO NORTHWEST WINDS AROUND 10 KNOTS OR
LESS. MDT TO HIGH CONFIDENCE.
&&
.MARINE...
HIGH PRESSURE OVERHEAD WITH SUB-ADVISORY CONDITIONS CONTINUING FOR
OUR AREA WATERS. VERY VERY QUIET ON OUR NJ AND DE WATERS WITH SEAS
AT OR BELOW 2 FEET. LIGHT WEST TO NORTH NORTHWEST OFFSHORE WINDS
IN THE OVERNIGHT AND MORNING HOURS WITH AFTERNOON SOUTH TO
SOUTHEAST ONSHORE SEA BREEZES OF 10 TO 15 KT.
WATER TEMPERATURES ARE SHOWING SIGNIFICANT ABOVE NORMAL DEPARTURES
WITH ONLY MINOR UPWELLING-COOLING VCNTY THE ENTRANCE TO DE BAY TO
THE CENTRAL NJ COAST.
OUTLOOK...
THU THROUGH SUN...NO MARINE FLAGS ARE ANTICIPATED THRU SUN. WIND
WILL BE OF THE SOUTH TO SOUTHWEST THROUGH FRI GENLY 10 KTS OR
LESS, INCREASING TO 15 KTS ON SAT. SAT NIGHT INTO SUN, WIND CUD
GUST TO 20 KTS OR SO AHEAD OF AN APPROACHING CDFNT. BEHIND THE
CFP, THE WIND WILL BECOME MORE WLY.. SEAS WILL GENERALLY BE AROUND
1 TO 2 FEET THU AND FRI, INCREASING TO AROUND 3 FEET BY SUN.
&&
.RIP CURRENTS...
STILL LOOKS LIKE LOW RISK MUCH OF, IF NOT ALL OF THE REST OF THIS
WEEK THROUGH SUNDAY MORNING AND ITS ALSO A VERY GOOD WORKWEEK TO
BE AT THE BEACH WITH PLENTY OF SUN THROUGH FRIDAY AND GENERALLY
SMALL WAVES. WATER TEMPERATURES CONTINUE ABOVE NORMAL AND IN THE
70S THOUGH THERE HAS BEEN SOME UPWELLING OF COOLER WATER FROM THE
ENTRANCE OF DE BAY NORTHWARD TO THE CENTRAL NJ COAST.
LOW CLOUDS MAY VISIT COASTAL SECTIONS SATURDAY MORNING TAKING A
LITTLE SHINE OFF THE DAY THERE.
A LOW RISK FOR THE FORMATION OF DANGEROUS RIP CURRENTS DOES NOT
MEAN NO RISK. PLEASE SWIM SAFELY. IF IN DOUBT DONT GO OUT. AVOID
SWIMMING NEAR JETTIES/PIERS AND GROINS.
00Z/16 OPERATIONAL MODELS AND ENSEMBLES (00Z/16 GEFS AND ECEFS)
SUGGEST NEXT WEEK MAY SEE A PERSISTENT NORTHEAST WIND...MORE CLOUD
COVER, LARGER SURF AND A CONSEQUENT MODERATE OR GREATER RISK FOR
DANGEROUS RIP CURRENT FORMATION AND AT THIS TIME WE THINK MONDAY
AND TUESDAY OF NEXT WEEK MIGHT BE FIRST DAYS OF MDT. SO THAT
WOULD MAKE THIS WEEK A MUCH SAFER AND BETTER WEEK TO TAKE ADVANTAGE
OF THE BEACH AS OPPOSED TO DELAYING TO NEXT WEEK. WE`RE QUITE SURE
THIS IS GOOD WEEK TO BE AT THE SHORE, ESPECIALLY PRIOR TO
SATURDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...NIERENBERG
NEAR TERM...DRAG/GIGI
SHORT TERM...DRAG
LONG TERM...NIERENBERG
AVIATION...GIGI/NIERENBERG
MARINE...DRAG/NIERENBERG
RIP CURRENTS...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1118 AM EDT WED SEP 16 2015
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN ACROSS THE REGION THROUGH THURSDAY
BEFORE MOVING EASTWARD FRIDAY AND SATURDAY. A WEAK COLD FRONT
WILL CROSS AREA SUNDAY THROUGH SUNDAY NIGHT. HIGH PRESSURE WILL
BUILD ACROSS THE NORTHEASTERN UNITED STATES FOR THE EARLY PART OF
NEXT WEEK, WITH SOME MOISTURE POTENTIALLY MOVING UP FROM THE SOUTH
ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
12Z SOUNDINGS AND LOOKING AT THE UPPER AIR ANALYSES STILL SHOW
NO BIG CHANGES TO ONGOING FORECAST FOR MAX TEMPS. RELATIVELY
WARMER POCKET AT 925MB AND 850MB SURROUNDING THE NYC METRO
AREA. TEMPERATURES ARE RISING SLIGHTLY AHEAD OF SCHEDULE, SO DID
SOME NEAR NEAR TERM ADJUSTMENTS. LITERALLY SLIGHTLY STRONGER
SEA/BAY BREEZE DEPICTED ON LAST COUPLE OF HRRR RUNS, BUT OVERALL
NOT MUCH CHANGE FROM CURRENT FORECAST.
550 AM: RAISING TEMPS 1F TO GET PHL SOMERVILLE MORRISTOWN TO
AROUND 88 THIS AFTN. 06Z GFS HAD A LARGE AREA OF 2M TEMPS AROUND
85 AT 18Z. 850 TEMPS 14-15C.
TODAY...THE REMAINING THIN CIRRUS NEAR 30000 FT SHOULD BE THE ONLY
CLOUDS WE SEE TODAY AND THE SUN SHOULD EASILY SHINE THROUGH. THIS
AFTERNOON THERE SHOULD BE LESS CIRRUS THAN WHATEVER OCCURS THIS
MORNING. CALL IT MOSTLY SUNNY OR SUNNY BUT PROBABLY NOT QUITE AS
BRIGHT AS YESTERDAY.
GFS HAS BEEN BEST AT DEPICTING THIS 200MB RH IN ITS TSECTION
PROFILES. PLAN VIEW OF THE 200MB RH IN THE GFS20 3HLY DATA SHOWS
THIS CLOUDINESS SEEMINGLY GENERATED BY A RRQ OF 50 KT 200MB SPEED
MAX MOVING SE OF CAPE COD THIS MORNING AND THE LF QUAD OF THE
DIXIE SHORT WAVE SPEED MAX THAT INTENSIFIES WITH TIME AS THAT
SPEED MAX MOVES NE THROUGH THE CAROLINAS TODAY. THE BACK EDGE OF
THE CIRRUS SPREADS EWD INTO E PA NEAR 00Z/17 TONIGHT.
BOUNDARY LAYER TEMPS ARE WARMING AND MODEL GUIDANCE INDICATES A
GENERAL LIGHT WESTERLY WIND THOUGH AFTERNOON SEABREEZES WILL
BECOME COMMON. USED THE WARMER 00Z/16 GFS MOS GUIDANCE AS THE
PRIMARY TEMP GUIDANCE, OTRW A 50/50 BLEND OF THE 00Z/16 GFS/NAM
FOR ALL OTHER ELEMENTS.
RECENT USE OF GUIDANCE ON MOSTLY SUNNY DAYS HAS SHOWN MAX`S TO
VERIFY 18Z 2M TEMPS +5 FOR BOTH THE ECMWF AND NAM AND PLUS 3F FOR
THE SEEMINGLY RECENTLY IMPROVED 18Z 2M TEMP FCSTS OF THE GFS. GFS
2M TEMP FCST FOR PHL IS ABOUT 85... NOT IMPOSSIBLE TO SEE A FEW
89, 90F READINGS IN THE I-95 CORRIDOR THIS AFTN FROM KPHL NNEWD
TO NEAR KMMU. NAM BL TEMP MAX`S OUT AT 26C NEAR 21Z.
MAX TEMPS GENERALLY ABOUT 10F ABOVE NORMAL.
HIGH CONFIDENCE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
CALM AND CLEAR OR MOSTLY CLEAR WITH ANY LEFTOVER 200MB CIRRUS EDGING
SEWD ..THE BACK EDGE ACROSS S DE AND CAPE MAY NJ AT 12Z THU.
GENERALLY EXCELLENT RADIATING CONDITIONS. PATCHY FOG POSSIBLE
AFTER 04Z IN SOME OF THE COUNTRYSIDE. USED THE LESS PROLIFIC
GENERATING UPS CROSSOVER TOOL TONIGHT AND BASICALLY THE SAME AREA
AS WE HAD IT POSTED THIS MORNING.
ITS POSSIBLE THERE WILL BE SOME FOG IN SE NJ LATE TONIGHT BUT FOR
NOW FAVORED THE MORE CONSERVATIVE PREDICTOR IN THIS DRY AND WARM
BOUNDARY LAYER.
50 50 BLENDED 00Z/16 NAM/GFS MOS GUIDANCE.
NEAR NORMAL MIN TEMPS.
HIGH CONFIDENCE.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL BE THE DOMINANT FEATURE AT THE START OF THE
EXTENDED PD AND EXPECT OUR BRILLIANT STRETCH OF WX TO CONTINUE
INTO THE FIRST PART OF THE WEEKEND.
A LARGE AREA OF HIGH PRES WILL REMAIN OVER THE AREA ON THU, BEFORE
MOVG EWD ON FRI AND SAT. THIS HIGH WILL KEEP US DRY, WITH PLEASANT
TEMPS AND A MAINLY CLEAR SKY.
LOW PRES IN HUDSON BAY WILL MOVE EWD AND AND ANOTHER AREA OF LOW
PRES IS EXPECTED TO FORM ALG THE ATTENDANT CDFNT NR THE GRTLKS ON
SAT. HOWEVER, THIS LOW IS ALSO EXPECTED TO MOVE NEWD AND THE
LATEST DATA INDICATES BY THE TIME THE CDFNT REACHES OUR REGION ON
SUN, IT WILL HAVE LITTLE MOISTURE WITH IT. SO THE NEXT CHC OF ANY
RAIN WILL BE LATER ON SUN, AND IT MAY NOT BE MUCH OF A CHC AT ALL.
BEHIND THE CFP, HIGH PRES WILL BUILD TO OUR N FOR MON, KEEPING
MONDAY DRY, BUT HERE IS WHERE THINGS START TO GET A LITTLE
INTERESTING.
ALL OF THE GUID WANTS TO DEVELOP SOME SORT OF LOW OFF THE SERN
CONUS CST AND BRING THE MOISTURE NWD ON TUE. THE GFS IS FURTHER S
WITH THE AFOREMENTIONED HIGH AND KEEPS THE MOISTURE LIGHTER AND
MAINLY OVER SRN PORTIONS OF THE AREA.
ON THE OTHER HAND, THE ECMWF IS FURTHER N WITH THE HIGH (CENTERED
IN QUEBEC) AND BRINGS THE MOISTURE FURTHER N AND IS HEAVIER WITH
IT.
AT THIS STAGE NOT SURE WHICH ONE WILL BE CORRECT, OR IF THE TRUTH
WILL LIE SOMEWHERE IN THE MIDDLE, AND THIS IS A FAIRLY LARGE
CHANGE, ESPECIALLY FOR THE ECMWF. WOULD LIKE TO SEE SOME RUN-TO-
RUN CONTINUITY BEFORE MAKING MAJOR CHANGES TO THE FCST. HOWEVER, A
WETTER SIGNAL IS THERE, SO HAVE AT LEAST ADDED SOME LOW POPS.
ALSO, DUE TO THE POSN OF THE HIGH, THERE WILL BE A FAIRLY
PRONOUNCED NELY FLOW WHICH WILL KEEP THINGS RATHER CLOUDY
REGARDLESS OF PRECIP OR NOT, SO IT CERTAINLY DOES NOT LOOK AS NICE
AS THIS WEEK.
TEMPS WILL START OFF ABV NRML, WITH THE WARMEST DAY LIKELY BEING
THU AND THEN DECREASE EACH DAY WITH MON AND TUE BEING COOLEST IN
THE CLOUDS AND NELY FLOW BEHIND THE CDFNT.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
AFTER 12Z TODAY...VFR WITH THIN CIRRUS NEAR 30000 FT DISSIPATING
EWD THIS AFTERNOON EXCEPT LINGERING KPHL SEWD. LIGHT WEST WIND
THIS MORNING WITH SEA AND BAY BREEZES THIS AFTERNOON AT KACY/KILG
AND POSSIBLY KMIV.
TONIGHT...VFR MOSTLY CLEAR AND CALM WIND. PATCHY IFR FOG IN SOME
OF THE E PA AND NJ COUNTRYSIDE...MAINLY I-78 NORTH. THIN CIRRUS
MAY HANG MUCH OF THE NIGHT VCNTY KMIV.
OUTLOOK...
THU THROUGH SAT...MAINLY VFR CONDS EXPECTED. PATCHY FOG PSBL FRI
AND SAT AM, ESPECIALLY AT THE MORE RURAL TERMINALS. WINDS WILL
REMAIN LIGHT THROUGH THE WEEK, GENERALLY AT OR BELOW 10 KNOTS, OUT
OF THE S OR SW. HIGH CONFIDENCE.
SUN...MAINLY VFR CONDITIONS EXPECTED. MVFR POSSIBLE IN LOW CHC
SHRA WITH A WEAK CFP. WEST TO NORTHWEST WINDS AROUND 10 KNOTS OR
LESS. MDT TO HIGH CONFIDENCE.
&&
.MARINE...
HIGH PRESSURE OVERHEAD WITH SUB-ADVISORY CONDITIONS CONTINUING FOR
OUR AREA WATERS. VERY VERY QUIET ON OUR NJ AND DE WATERS WITH SEAS
AT OR BELOW 2 FEET. LIGHT WEST TO NORTH NORTHWEST OFFSHORE WINDS
IN THE OVERNIGHT AND MORNING HOURS WITH AFTERNOON SOUTH TO
SOUTHEAST ONSHORE SEA BREEZES OF 10 TO 15 KT.
WATER TEMPERATURES ARE SHOWING SIGNIFICANT ABOVE NORMAL DEPARTURES
WITH ONLY MINOR UPWELLING-COOLING VCNTY THE ENTRANCE TO DE BAY TO
THE CENTRAL NJ COAST.
OUTLOOK...
THU THROUGH SUN...NO MARINE FLAGS ARE ANTICIPATED THRU SUN. WIND
WILL BE OF THE SOUTH TO SOUTHWEST THROUGH FRI GENLY 10 KTS OR
LESS, INCREASING TO 15 KTS ON SAT. SAT NIGHT INTO SUN, WIND CUD
GUST TO 20 KTS OR SO AHEAD OF AN APPROACHING CDFNT. BEHIND THE
CFP, THE WIND WILL BECOME MORE WLY.. SEAS WILL GENERALLY BE AROUND
1 TO 2 FEET THU AND FRI, INCREASING TO AROUND 3 FEET BY SUN.
&&
.RIP CURRENTS...
STILL LOOKS LIKE LOW RISK MUCH OF, IF NOT ALL OF THE REST OF THIS
WEEK THROUGH SUNDAY MORNING AND ITS ALSO A VERY GOOD WORKWEEK TO
BE AT THE BEACH WITH PLENTY OF SUN THROUGH FRIDAY AND GENERALLY
SMALL WAVES. WATER TEMPERATURES CONTINUE ABOVE NORMAL AND IN THE
70S THOUGH THERE HAS BEEN SOME UPWELLING OF COOLER WATER FROM THE
ENTRANCE OF DE BAY NORTHWARD TO THE CENTRAL NJ COAST.
LOW CLOUDS MAY VISIT COASTAL SECTIONS SATURDAY MORNING TAKING A
LITTLE SHINE OFF THE DAY THERE.
A LOW RISK FOR THE FORMATION OF DANGEROUS RIP CURRENTS DOES NOT
MEAN NO RISK. PLEASE SWIM SAFELY. IF IN DOUBT DONT GO OUT. AVOID
SWIMMING NEAR JETTIES/PIERS AND GROINS.
00Z/16 OPERATIONAL MODELS AND ENSEMBLES (00Z/16 GEFS AND ECEFS)
SUGGEST NEXT WEEK MAY SEE A PERSISTENT NORTHEAST WIND...MORE CLOUD
COVER, LARGER SURF AND A CONSEQUENT MODERATE OR GREATER RISK FOR
DANGEROUS RIP CURRENT FORMATION AND AT THIS TIME WE THINK MONDAY
AND TUESDAY OF NEXT WEEK MIGHT BE FIRST DAYS OF MDT. SO THAT
WOULD MAKE THIS WEEK A MUCH SAFER AND BETTER WEEK TO TAKE ADVANTAGE
OF THE BEACH AS OPPOSED TO DELAYING TO NEXT WEEK. WE`RE QUITE SURE
THIS IS GOOD WEEK TO BE AT THE SHORE, ESPECIALLY PRIOR TO
SATURDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...NIERENBERG
NEAR TERM...DRAG/GIGI
SHORT TERM...DRAG
LONG TERM...NIERENBERG
AVIATION...DRAG/NIERENBERG
MARINE...DRAG/NIERENBERG
RIP CURRENTS...
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
940 PM EDT THU SEP 17 2015
.DISCUSSION...
...FLOOD WATCH CONTINUES FOR THE COASTAL COUNTIES THROUGH FRIDAY...
BROAD TROF/LOW PRES SYSTEM CENTERED JUST OFF THE SW FL COAST HAS
BEEN DRIFTING VERY SLOWLY NEWD...ITS FORWARD MOTION BLOCKED BY A
LARGE H100-H70 RIDGE EXTENDING FROM THE TX COAST TO GEORGES BANK.
TROF AXIS CUTS ACRS THE FL PENINSULA FROM FT MYERS TO CAPE
CANAVERAL...RESULTING IN A LIGHT TO GENTLE NE FLOW ALONG AND N OF
THE I-4 CORRIDOR...GENTLE TO MODERATE SW BREEZE LIGHT/VRBL FLOW TO
THE SOUTH. LCL AIRMASS REMAINS NEARLY SATURATED FROM SFC-WIG WITH
PWAT VALUES RUNNING BTWN 2.2"-2.3" ACRS THE S HALF OF THE PENINSULA
AND ARND 2.0" OVER THE N HALF.
HEAVY RAIN HAS FALLEN ACRS THE TREASURE COAST TODAY WITH MULTIPLE
REPORTS REPORTS BTWN 4"-6" SINCE EARLY MRNG...MANY REPORTS OF
FLOODING OVER MARTIN/ST. LUCIE COUNTIES LATE THIS AFTN. EVEN SO...
RADAR TREND SHOWS DIMINISHING PRECIP AREAWIDE: MORE WIDESPREAD S OF
SR60 ON THE ASCENDING SIDE OF THE TROF AXIS...ONLY BRIEF ISOLD SHRAS
TO THE N WHERE NERLY WINDS ON THE DESCENDING FLANK PREVAIL.
DIMINISHING PRECIP TREND SHOULD CONTINUE THRU MIDNIGHT WITH THE LOSS
OF WHAT LITTLE DIURNAL HEATING THAT WAS AVAILABLE TODAY. INDEED...
LATEST RAP ANALYSIS SHOWS THE H30-H20 LYR HAS BCM LARGELY CONVERGENT
OVER THE PAST SVRL HRS. RESPECTABLE MID LYR VORT MAXES OVERHEAD DUE
TO THE POSITION OF THE LOW...BUT WITH MINIMAL WINDS ARND ITS AXIS
GENERATING NEGLIGIBLE PVA. LCL 3KM WRF MODEL SUGGESTING MOST OF ANY
ADDITIONAL PRECIP OVERNIGHT WILL OCCUR ON THE ASCENDING FLANK OF THE
TROF ARND LAKE OKEECHOBEE AND ALONG THE TREASURE COAST AS THE LOW
SLOWLY TRANSITS FROM THE SW GOMEX INTO THE ATLC.
WILL CUT POPS BACK TO AOB 50PCT ACRS THE CENTRAL/NRN CWA AND REMOVE
THUNDER FROM THE FCST. WILL KEEP LKLY POPS IN FOR THE TREASURE
COAST/LAKE OKEECHOBEE REGION WITH SLGT CHC TSRAS. NO OTHER CHANGES
NECESSARY.
&&
.AVIATION...THRU 10/00Z
SFC WINDS:
N OF KMLB-KISM...THRU 18/14Z...N/NW ARND 3KTS. BTWN 18/14Z-18/18Z
W/NW BTWN 5-8KTS...BTWN 18/18Z-18//21Z BCMG E/NE 7-10KTS.
S OF KMLB-KISM...THRU 18/14Z...CALM. BTWN 18/14Z-18/18Z...W/SW BTWN
4-6KTS. BTWN 18/18Z-18/21Z BCMG E/SE 5-8KTS.
VSBYS/WX/CIGS:
N OF KMLB-KISM...THRU 08/14Z...SLGT CHC MVFR SHRAS...AREAS OF IFR
CIGS BTWN 18/08Z-18/12Z. AFT 18/14Z...MVFR SHRAS BCMG WDSPRD WITH
ISOLD IFR TSRAS.
S OF KMLB-KISM...THRU 08/14Z...MVFR SHRAS LIKELY WITH SLGT CHC IFR
TSRAS. AFT 18/14Z...MVFR SHRAS BCMG WDSPRD WITH ISOLD IFR TSRAS.
&&
.MARINE...
LIGHT/VRBL WINDS OVERNIGHT AS A WEAK INVERTED TROF OVER THE LCL ATLC
DISRUPTS THE LCL PRES FIELD. WINDS LARGELY OUT OF THE N/NE OVER THE
NEARSHORE WATERS...AND FROM THE S/SE OVER THE OFFSHORE LEG. SEAS
3-4FT MAINLY IN AN ERLY SWELL WITH DOMINANT PDS BTWN 6-7SEC. CHC
SHRAS N OF CAPE CANAVERAL...SHRAS LIKELY WITH A SLGT CHC TSRAS OVER
THE GULF STREAM S OF THE CAPE.
&&
.HYDROLOGY...(PREV DISC)
AS A RESULT OF THE RECENT HEAVY RAINS...THE SAINT JOHNS RIVER ABOVE
LAKE HARNEY /GENF1/ HAS REACHED 5.8FT...WHICH IS LESS THAN A FOOT
BELOW ACTION STAGE (6.5FT). THE RIVER IS FORECAST TO REACH THE LOWER
THRESHOLD OF ACTION STAGE (6.6FT) THERE LATE SATURDAY NIGHT OR EARLY
SUNDAY MORNING...AND REMAIN THERE THROUGH EARLY NEXT WEEK.
THE SAINT JOHNS RIVER AT ASTOR /ASTF1/ HAS REACHED 2.0FT...WHICH
IS ONE HALF FOOT BELOW ACTIONS STAGE (2.5FT). THE RIVER IS
FORECAST TO REMAIN BELOW ACTIONS STAGE...GRADUALLY CRESTING NEAR
2.2 TO 2.3FT THIS WEEKEND...AND REMAINING STEADY STATE THROUGH
EARLY NEXT WEEK.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...FLOOD WATCH THROUGH FRIDAY EVENING FOR COASTAL VOLUSIA COUNTY-
INDIAN RIVER-MARTIN-NORTHERN BREVARD COUNTY-SOUTHERN
BREVARD COUNTY-ST. LUCIE.
AM...NONE.
&&
$$
FORECAST/AVIATION...BRAGAW
RADAR/IMPACT WX.....KELLY
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1249 PM CDT WED SEP 16 2015
...Update to aviation forecast discussion...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT WED SEP 16 2015
A mid level trough moving across west central Kansas along with the
southerly low level jet were helping to maintain elevated showers
and thunderstorms across central Kansas north into central Nebraska
at 08Z. Isentropic lift on the 315K surface will also help maintain
the elevated convection, similar to yesterday through the morning
hours. Short range hi resolution models keep the convection going
this morning across north central and northeast Kansas before
diminishing by mid day. The HRRR was the most aggressive with the
precipitation and have cut back a bit as the low level jet weakens
this morning and the trough moves out. Tight pressure gradient
continues across Kansas this morning and will continue through the
day. Forecast soundings show mixing down from 850 mb this afternoon
and could see some wind gusts of 35 to 40 mph with sustained winds
of 20 to 25 mph. Highs today should range from the lower 90s in
north central Kansas to the upper 80s across northeast and east
central Kansas. Tonight winds will remain breezy with the mixed
boundary layer. The southerly winds and some increase in cloud cover
will keep low temperatures mild, generally in the lower to middle
70s.
.LONG TERM...(Thursday through Tuesday)
ISSUED AT 327 AM CDT WED SEP 16 2015
By Thursday morning, southwesterly flow aloft will be in place as a
mid-level trough builds in across the northwestern and north central
U.S. Models show two embedded shortwave troughs within this broad
mid-level trough, with the first progressing across the Northern
Plains toward the northern Great Lakes Thursday into Thursday night.
This shortwave will help to push the area of surface low pressure
currently stretched across the High Plains eastward toward the area,
with the associated cold front likely advancing into far north
central Kansas by Thursday afternoon. This front should slowly shift
southeastward across the CWA through the afternoon and evening
hours, becoming stalled out over the area. However, it is worth
noting the the 00z GFS seems a bit faster with the advancement of
the cold front across the CWA, and thus shows the front becoming
stalled out a bit further south than other models. With much of the
CWA remaining in the warm sector through the afternoon with
southwesterly winds remaining breezy with gusts of 25-30mph, expect
high temperatures to reach into the upper 80s to low 90s once again.
A decent cap should be in place through much of the afternoon hours,
but expect it to slowly erode away by late afternoon or early
evening. A few models are trying to show some very light
precipitation in the morning from some isentropic lift, however feel
that there is too much dry air in the low-levels so have kept a dry
forecast for the morning hours at this time. With a diminishing
cap, increasing lift and convergence near the boundary, CAPE values
upwards of 2000 J/kg, and 0-6 km bulk shear values of 30-35 kts,
conditions will be conducive for thunderstorm development by late
afternoon or early evening and persist through the overnight hours
into Friday as the boundary stalls out over the area. A few of
these storms could be strong to severe with the primary concerns
being damaging winds and possibly some large hail. Ongoing storms
will become more elevated by the overnight hours. With the
increasing low-level jet likely becoming nearly parallel to the
stalled boundary, could potentially see training thunderstorms and
even some locally heavy rain and localized flooding as PWAT values
reach upwards of 1.6-1.8 inches. By Friday, the boundary is
expected to shift a bit further north across the CWA and should
finally progress eastward out of the area Friday night as the second
embedded shortwave moves into the area, helping to push the stalled
system eastward. However, there will still be abundant moisture,
good instability, and actually better 0-6km bulk shear Friday
afternoon/evening with the cap potentially eroding away by mid to
late afternoon. As a result, strong to severe thunderstorms will be
possible again on Friday, however this potential will be very
dependent upon how quickly the system ends up exiting the area. The
uncertainties in the exact timing of this system progressing
eastward also impacts the temperature forecast for Friday as there
may be a decent gradient with high temperatures ranging from the
upper 70s to upper 80s from northwest to southeast.
By Saturday, surface high pressure advances into the central U.S.
behind the exiting system, with northerly winds ushering cooler air
into the region. As a result, expect weekend highs in the mid 70s
and lows in the 50s. While another mid-level trough should slide
over the area Sunday into Monday, feel that the better moisture will
stay south of the CWA so have a dry forecast through the weekend.
The region should remain under the influence of high pressure
through early next week, keeping conditions dry. With surface low
pressure building into the High Plains, should see winds shift more
toward the south, which should help to boost high temperatures back
into the 80s for Tuesday and Wednesday.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Thursday AFTERNOON)
ISSUED AT 1226 PM CDT WED SEP 16 2015
For the 18z TAFs, generally expect VFR conditions over the next
24hrs. Winds stay strong out of the South and continue to gust
this afternoon before calming this evening. Still think that the
gradient will stay in place ahead of the lee trough, so expecting
to stay fairly well mixed tonight. Therefore, have opted to keep
mention of wind shear out of the TAFs at this time until better
consensus can be formed later today for the 12z time frame. At
this point, the best areas for wind shear will likely remain
northwest of the terminals. Thunderstorm chances remain to
low confidence to place into the TAFs. The current storms remain
to the west and northwest of the terminals over central KS and
into southeastern NE. These should slowly dissipate over the next
few hours. Cloud cover will likely be increasing by early morning
though and could end up seeing a bit lower stratus deck especially
near KMHK.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...53
LONG TERM...Hennecke
AVIATION...Drake
AREA FORECAST DISCUSSION
NWS TOPEKA KS
623 AM CDT WED SEP 16 2015
...Update to aviation forecast discussion...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT WED SEP 16 2015
A mid level trough moving across west central Kansas along with the
southerly low level jet were helping to maintain elevated showers
and thunderstorms across central Kansas north into central Nebraska
at 08Z. Isentropic lift on the 315K surface will also help maintain
the elevated convection, similar to yesterday through the morning
hours. Short range hi resolution models keep the convection going
this morning across north central and northeast Kansas before
diminishing by mid day. The HRRR was the most aggressive with the
precipitation and have cut back a bit as the low level jet weakens
this morning and the trough moves out. Tight pressure gradient
continues across Kansas this morning and will continue through the
day. Forecast soundings show mixing down from 850 mb this afternoon
and could see some wind gusts of 35 to 40 mph with sustained winds
of 20 to 25 mph. Highs today should range from the lower 90s in
north central Kansas to the upper 80s across northeast and east
central Kansas. Tonight winds will remain breezy with the mixed
boundary layer. The southerly winds and some increase in cloud cover
will keep low temperatures mild, generally in the lower to middle
70s.
.LONG TERM...(Thursday through Tuesday)
ISSUED AT 327 AM CDT WED SEP 16 2015
By Thursday morning, southwesterly flow aloft will be in place as a
mid-level trough builds in across the northwestern and north central
U.S. Models show two embedded shortwave troughs within this broad
mid-level trough, with the first progressing across the Northern
Plains toward the northern Great Lakes Thursday into Thursday night.
This shortwave will help to push the area of surface low pressure
currently stretched across the High Plains eastward toward the area,
with the associated cold front likely advancing into far north
central Kansas by Thursday afternoon. This front should slowly shift
southeastward across the CWA through the afternoon and evening
hours, becoming stalled out over the area. However, it is worth
noting the the 00z GFS seems a bit faster with the advancement of
the cold front across the CWA, and thus shows the front becoming
stalled out a bit further south than other models. With much of the
CWA remaining in the warm sector through the afternoon with
southwesterly winds remaining breezy with gusts of 25-30mph, expect
high temperatures to reach into the upper 80s to low 90s once again.
A decent cap should be in place through much of the afternoon hours,
but expect it to slowly erode away by late afternoon or early
evening. A few models are trying to show some very light
precipitation in the morning from some isentropic lift, however feel
that there is too much dry air in the low-levels so have kept a dry
forecast for the morning hours at this time. With a diminishing
cap, increasing lift and convergence near the boundary, CAPE values
upwards of 2000 J/kg, and 0-6 km bulk shear values of 30-35 kts,
conditions will be conducive for thunderstorm development by late
afternoon or early evening and persist through the overnight hours
into Friday as the boundary stalls out over the area. A few of
these storms could be strong to severe with the primary concerns
being damaging winds and possibly some large hail. Ongoing storms
will become more elevated by the overnight hours. With the
increasing low-level jet likely becoming nearly parallel to the
stalled boundary, could potentially see training thunderstorms and
even some locally heavy rain and localized flooding as PWAT values
reach upwards of 1.6-1.8 inches. By Friday, the boundary is
expected to shift a bit further north across the CWA and should
finally progress eastward out of the area Friday night as the second
embedded shortwave moves into the area, helping to push the stalled
system eastward. However, there will still be abundant moisture,
good instability, and actually better 0-6km bulk shear Friday
afternoon/evening with the cap potentially eroding away by mid to
late afternoon. As a result, strong to severe thunderstorms will be
possible again on Friday, however this potential will be very
dependent upon how quickly the system ends up exiting the area. The
uncertainties in the exact timing of this system progressing
eastward also impacts the temperature forecast for Friday as there
may be a decent gradient with high temperatures ranging from the
upper 70s to upper 80s from northwest to southeast.
By Saturday, surface high pressure advances into the central U.S.
behind the exiting system, with northerly winds ushering cooler air
into the region. As a result, expect weekend highs in the mid 70s
and lows in the 50s. While another mid-level trough should slide
over the area Sunday into Monday, feel that the better moisture will
stay south of the CWA so have a dry forecast through the weekend.
The region should remain under the influence of high pressure
through early next week, keeping conditions dry. With surface low
pressure building into the High Plains, should see winds shift more
toward the south, which should help to boost high temperatures back
into the 80s for Tuesday and Wednesday.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Thursday MORNING)
ISSUED AT 623 AM CDT WED SEP 16 2015
VFR conditions are expected to continue through the period. Low
level wind shear will continue through 14Z when surface winds
increase. South winds around 16kts are expected with gusts to near
30 kts in the afternoon. After 01Z wind gusts should subside, but
winds will remain around 15 kts. Convection west of MHK is
expected to dissipate by 17Z and should remain out of the MHK
terminal area.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...53
LONG TERM...Hennecke
AVIATION...53
AREA FORECAST DISCUSSION
NWS TOPEKA KS
338 AM CDT WED SEP 16 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT WED SEP 16 2015
A mid level trough moving across west central Kansas along with the
southerly low level jet were helping to maintain elevated showers
and thunderstorms across central Kansas north into central Nebraska
at 08Z. Isentropic lift on the 315K surface will also help maintain
the elevated convection, similar to yesterday through the morning
hours. Short range hi resolution models keep the convection going
this morning across north central and northeast Kansas before
diminishing by mid day. The HRRR was the most aggressive with the
precipitation and have cut back a bit as the low level jet weakens
this morning and the trough moves out. Tight pressure gradient
continues across Kansas this morning and will continue through the
day. Forecast soundings show mixing down from 850 mb this afternoon
and could see some wind gusts of 35 to 40 mph with sustained winds
of 20 to 25 mph. Highs today should range from the lower 90s in
north central Kansas to the upper 80s across northeast and east
central Kansas. Tonight winds will remain breezy with the mixed
boundary layer. The southerly winds and some increase in cloud cover
will keep low temperatures mild, generally in the lower to middle
70s.
.LONG TERM...(Thursday through Tuesday)
ISSUED AT 327 AM CDT WED SEP 16 2015
By Thursday morning, southwesterly flow aloft will be in place as a
mid-level trough builds in across the northwestern and north central
U.S. Models show two embedded shortwave troughs within this broad
mid-level trough, with the first progressing across the Northern
Plains toward the northern Great Lakes Thursday into Thursday night.
This shortwave will help to push the area of surface low pressure
currently stretched across the High Plains eastward toward the area,
with the associated cold front likely advancing into far north
central Kansas by Thursday afternoon. This front should slowly shift
southeastward across the CWA through the afternoon and evening
hours, becoming stalled out over the area. However, it is worth
noting the the 00z GFS seems a bit faster with the advancement of
the cold front across the CWA, and thus shows the front becoming
stalled out a bit further south than other models. With much of the
CWA remaining in the warm sector through the afternoon with
southwesterly winds remaining breezy with gusts of 25-30mph, expect
high temperatures to reach into the upper 80s to low 90s once again.
A decent cap should be in place through much of the afternoon hours,
but expect it to slowly erode away by late afternoon or early
evening. A few models are trying to show some very light
precipitation in the morning from some isentropic lift, however feel
that there is too much dry air in the low-levels so have kept a dry
forecast for the morning hours at this time. With a diminishing
cap, increasing lift and convergence near the boundary, CAPE values
upwards of 2000 J/kg, and 0-6 km bulk shear values of 30-35 kts,
conditions will be conducive for thunderstorm development by late
afternoon or early evening and persist through the overnight hours
into Friday as the boundary stalls out over the area. A few of
these storms could be strong to severe with the primary concerns
being damaging winds and possibly some large hail. Ongoing storms
will become more elevated by the overnight hours. With the
increasing low-level jet likely becoming nearly parallel to the
stalled boundary, could potentially see training thunderstorms and
even some locally heavy rain and localized flooding as PWAT values
reach upwards of 1.6-1.8 inches. By Friday, the boundary is
expected to shift a bit further north across the CWA and should
finally progress eastward out of the area Friday night as the second
embedded shortwave moves into the area, helping to push the stalled
system eastward. However, there will still be abundant moisture,
good instability, and actually better 0-6km bulk shear Friday
afternoon/evening with the cap potentially eroding away by mid to
late afternoon. As a result, strong to severe thunderstorms will be
possible again on Friday, however this potential will be very
dependent upon how quickly the system ends up exiting the area. The
uncertainties in the exact timing of this system progressing
eastward also impacts the temperature forecast for Friday as there
may be a decent gradient with high temperatures ranging from the
upper 70s to upper 80s from northwest to southeast.
By Saturday, surface high pressure advances into the central U.S.
behind the exiting system, with northerly winds ushering cooler air
into the region. As a result, expect weekend highs in the mid 70s
and lows in the 50s. While another mid-level trough should slide
over the area Sunday into Monday, feel that the better moisture will
stay south of the CWA so have a dry forecast through the weekend.
The region should remain under the influence of high pressure
through early next week, keeping conditions dry. With surface low
pressure building into the High Plains, should see winds shift more
toward the south, which should help to boost high temperatures back
into the 80s for Tuesday and Wednesday.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Wednesday NIGHT)
ISSUED AT 1149 PM CDT TUE SEP 15 2015
VFR conditions expected through the period. LLWS overnight
expected at all terminals as winds aloft increase to at or greater
than 40kts. Surface gusts return tomorrow morning.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...53
LONG TERM...Hennecke
AVIATION...67
AREA FORECAST DISCUSSION
NWS PADUCAH KY
303 PM CDT WED SEP 16 2015
.SHORT TERM...(This evening through Saturday)
Issued at 303 PM CDT WED SEP 16 2015
Isolated showers over south central Missouri have done a good job
of staying to the west of our region this afternoon. Cannot
completely rule out one slipping east into Ripley or Carter
counties, but will leave the forecast dry, as the HRRR and WRF
runs really struggle to move the activity tangibly east.
The ridge aloft will be suppressed a bit Thursday night, and this
may allow some convection to drift off of the cold front and
possibly down to the I-64 corridor. The 12Z NAM was rather
agressive in bringing convection into our forecast area, but most
other models keep any such activity well to the north. The 12Z WRF
runs were split with one wet and the other dry. Will keep a slight
chance very late Thursday night through Friday morning. If
anything does reach the area it is expected to dissipate or move
east by 18Z, so the entire area should be dry Friday afternoon.
The cold front is expected to move through the region late Friday
night and mostly Saturday morning. There is some variability in
the timing, with the 12Z NAM holding it up over our southeast
late Saturday afternoon. If this happens there could be some
significant instability to play with. However, it has litte
support from any other 12Z models. Have trended a bit faster/sooner
with the frontal passage, and kept only small chance PoPs in the
northwest Friday night, and through the entire area through the
day.
As for temperatures, tried to lean toward the warmer MAV/EC
guidance for highs, which could result in some areas reaching 90
by Friday afternoon. The cold front will knock temperatures back
to normal levels Saturday. Lows will trend warmer through the
period. Consensus of guidance has the lows well in line.
.LONG TERM...(Saturday night through Wednesday)
Issued at 303 PM CDT WED SEP 16 2015
Models continue to show an upper level trof moving across the middle
Mississippi and lower Ohio Valleys Sunday into Sunday night. GFS
pretty much keeps us dry, and the latest ECMWF is trending toward
the GFS, and it now only generates very light QPF across our
southern half of counties. Continued with just slight chance pops
for showers across our far west counties in southeast Missouri on
Sunday, and our southern half of counties Sunday night and Monday.
After Monday, surface high pressure and upper level ridging will
keep us dry.
In the wake of the cold front, temperatures Saturday night will cool
down to near seasonal readings in the 50s, and Sunday through
Tuesday temperatures will be unseasonably cool as we remain in north
to northeast flow. By Wednesday we will moderate closer to seasonal
readings.
&&
.AVIATION...
Issued at 1219 PM CDT WED SEP 16 2015
A nice cu field at 5-6kft has developed east of the Mississippi
River late this morning. Cannot rule out a period or two of a
ceiling condition, but will keep the forecasts scattered. The 12Z
guidance indicates that there will less cu development Thursday.
With surface high pressure to the east, south winds under 10kts
will be the rule this afternoon and again by mid-morning Thursday.
Most places will keep a light south/southeast wind for much of the
night, so fog does not seem very likely, even at KCGI.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...DRS
LONG TERM...RST
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
844 PM EDT THU SEP 17 2015
.SYNOPSIS...
RAIN CHANCES WILL INCREASE AS A COLD FRONT MOVES OUT OF THE
MIDWEST THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
SURFACE HIGH PRESSURE WILL CONTINUE TO BE THE CONTROLLING FACTOR
FOR OUR WEATHER OVERNIGHT...EVEN AS THE CENTER OF THE HIGH STARTS
TO MOVE EAST OF THE APPALACHIAN FRONT. WHILE THIS SHOULD ALLOW
FOR A GRADIENT FLOW FROM THE SOUTHWEST IN THE LOW LEVELS...SURFACE
OBSERVATIONS AND RAP SOUNDINGS INDICATE INVERSIONS ARE ALREADY
HERE FOR THE NIGHT. AS A RESULT...SURFACE FLOW WILL REMAIN NEAR
NIL THROUGH THE NIGHT. THIS WILL YIELD CLEAR SKIES DUE TO A
DEARTH OF LAYER MOISTURE...AND VERY WEAK BOUNDARY LAYER FLOW. THIS
WILL BASICALLY MEAN THAT TEMPERATURES WILL HAVE THEIR EYES SET ON
THE DEWPOINTS FORTHWITH AS THEY FALL AGGRESSIVELY INTO THE LATER
EVENING. AND DUE TO THE LENGTH IN THE NIGHTS GOING INTO THE
FALL...DIURNAL DROPS AFTER A WARM DAY GET TO BE EASIER TO
ACCOMPLISH.
THE ONLY INFINITESIMALLY DIFFICULT PART OF THE FORECAST IS HOW TO
HANDLE THE DEWPOINT FORECAST. THERE IS A WINDOW OF SLIGHTLY LOWER
DEWPOINTS IN EASTERN INDIANA AND WESTERN OHIO...WHERE VALUES ARE
STRADDLING THE 50F MARK. HRRR GUIDANCE IS EXHIBITING ITS TYPICAL
DRY AFTERNOON BIAS DUE TO IRRATIONAL MIXING...AND WITH INVERSIONS
READY TO SET UP FAIRLY SHORTLY...THE WINDOW FOR GETTING DRIER AIR
INTO THE BOUNDARY LAYER IN OUR CWA IS QUICKLY CLOSING. THIS LEAVES
US WITH GENERALLY LOWER TO MIDDLE 50S ACROSS THE CWA...AND WHILE A
BIT OF THAT MOISTURE MAY BE REMOVED BY DEW DEPOSITION...IT SEEMS
UNLIKELY THAT LOWS WILL BREACH 50F ON AN ORGANIZED BASIS MUCH OF
ANYWHERE EXCEPT IN THE LOWEST VALLEYS AMONGST THE RIDGES. THERMAL
BELTS WILL LIKELY BE PRONOUNCED IN THE HIGHER TERRAIN...MUCH LIKE
LAST NIGHT...YIELDING INVERTED TEMPERATURE GRIDS OVER THE RIDGES.
ELSEWHERE...THE URBAN HEAT ISLAND SEEMS LIKELY TO BE A BIT
STRONGER AROUND PITTSBURGH THAN LAST NIGHT DUE TO THE INSOLATION
TODAY...HOWEVER OUTSIDE OF THERE...LOWS WILL PROBABLY ONLY BE UP A
COUPLE OF DEGREES FROM LAST NIGHT. FRIES
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
THE LAST COUPLE MODEL RUNS HAVE PRODUCED SOME LIGHT PRECIP WITH A
LEAD SHORTWAVE MOVING OUT OF THE MIDWEST LATE ON FRIDAY. HAVE
DECIDED TO INCLUDE A SLIGHT PRECIP PROB OVER EXTREME NWRN...AND
WRN ZONES FOR THIS FEATURE...ALTHOUGH LOW LEVEL LAYERS ARE LIKELY
TO BE SLOW MOISTENING SUFFICIENTLY. MAY END UP MORE OF A SPRINKLE
SITUATION. OTHERWISE...AN AFTERNOON AND EVENING MID LEVEL CLOUD
INCREASE CAN BE EXPECTED.
THE BETTER PRECIP CHANCE WILL STILL BE WITH THE LATE SATURDAY COLD
FRONT...POPS FOR WHICH WERE INCREASED AND ADJUSTED FOR THE QUICKER
TIMING OF THE LATEST GFS AND NAM TRENDS. NUMBERS WERE STILL
LIMITED TO THE CHANCE CATEGORY FOR NOW GIVEN OMEGA BULLSEYE
QUESTIONS AND EXPECTATIONS THAT MODEL-WORLD BOUNDARY MOISTURE MAY
BE TOO HIGH. PROGGED INSTABILITY IS THUS ALSO LIKELY TO BE
HIGH...AND WOULD NOT SUPPORT SEVERE STORMS DESPITE THE INCREASING
DEEP LAYER SHEAR IN THE TIGHTENING PRESSURE GRADIENT.
PASSAGE OF THE FRONT WILL DROP TEMPS BACK TO THE SEASONAL AVERAGES.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
BUILDING HIGH PRESSURE IS THEN PROJECTED TO BRING DRY AND
SEASONAL CONDITIONS SUNDAY AND MONDAY. THEREAFTER...FORECAST
CONFIDENCE DROPS QUICKLY AS DIFFERING MODEL SOLUTIONS PROVIDE NO
CLEAR PICTURE FOR THE END OF THE LONG TERM. THE FORECAST WAS THUS
BASED ON PERSISTENCE WITH ONLY MINOR CHANGES TO TUESDAY AND
WEDNESDAY.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL MAINTAIN VFR WITH EXCEPTIONS OF BRIEF DAWN FOG.
HAVE GONE WITH PERSISTENCE FORECASTS FROM THIS MORNINGS
OBSERVATIONS AT HLG/FKL/DUJ.
OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...
THE NEXT CHANCE FOR GENERAL RESTRICTIONS WILL COME WITH A LATE
SATURDAY COLD FRONT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1201 AM EDT FRI SEP 18 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 320 PM EDT THU SEP 17 2015
MULTIPLE ROUNDS OF SHOWERS AND THUNDERSTORMS WILL MOVE THROUGH THE
REGION...STARTING AS EARLY AS THIS EVENING AND CONTINUING
OVERNIGHT. ANOTHER ROUND OF STORMS LOOKS LIKELY FRIDAY NIGHT INTO
SATURDAY MORNING WITH SOME HEAVY RAINS EXPECTED. SOME FLOODING
COULD OCCUR WHERE STORMS PERSIST. COOLER AND BREEZY CONDITIONS
MOVE IN SATURDAY BEFORE A WARMING TREND STARTS AGAIN.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 320 PM EDT THU SEP 17 2015
THE TWO PRIMARY RISKS TO EVALUATE THROUGH SATURDAY MORNING WILL BE
DAMAGING WIND GUST POTENTIAL ALONG WITH LOCALIZED FLOODING. FOR
THIS EVENING...ALMOST ALL NUMERICAL GUIDANCE IS STRUGGLING WITH
THE CONVECTION ACROSS NORTHERN IL. ONLY THE HRRR HAS A CLUE ABOUT
CONVECTIVE TRENDS AT THIS POINT AND SUGGESTS THE RAIN WILL PROCEED
ACROSS THE LAKE THIS EVENING AND WEAKEN A BIT...IN SPITE OF SPC
SREF-BASED EFFECTIVE BULK SHEAR INCREASING OVER THE LAKE (THOUGH
CIN WILL BE GROWING TOWARD NIGHTFALL). BUMPED POPS UP THIS EVENING
ESPECIALLY NEAR/WEST OF US 131 TO INCLUDE THIS THREAT FOR STORMS
IN CASE THEY SURVIVE THE TRIP OVER THE LAKE. NOT EXPECTING ANY
SEVERE WEATHER WITH THIS.
LATER TONIGHT...LOOKS LIKE A LINE OF STORMS WILL SOLIDIFY ACROSS
EASTERN WI IN THE MIDST OF A MID LEVEL SHORTWAVE APPROACHING BY
06Z AND A 40 KT LLJ ADVECTING MOISTURE INTO THE REGION. THIS LINE
FORMS ALONG A WEAK COLD FRONT WHICH WILL SLOW DOWN AND STALL OUT
OVER THE HEART OF THE CWA FRIDAY. RAIN CHANCES LOOK QUITE LIKELY
OVERNIGHT THOUGH INSTABILITY LOOKS WEAK OR NONEXISTENT FOR MOST
PLACES. WITH ONLY MODEST WINDS ACROSS THE COLUMN...WOULD EXPECT
LITTLE OR NO SEVERE WEATHER WITH THIS ACTIVITY OVERNIGHT. THE
BIGGER THREAT WOULD BE LOCALLY HEAVY DOWNPOURS...MAYBE UP TO AN
INCH IN SPOTS. AREAS THAT GET THE HEAVIEST RAIN WOULD BE FAVORED
FOR A FLOOD THREAT FRIDAY NIGHT GIVEN MOIST SOILS AND HENCE SOME
FAVORABLE ANTECEDENT CONDITIONS.
THE SEVERE WEATHER THREAT DOES GO UP FRIDAY...ESPECIALLY IN THE
EVENING AND LASTING THROUGH THE NIGHT. DAMAGING WIND GUSTS AND
SOME FLOODING ARE BOTH POTENTIAL HAZARDS. THE SFC COLD FRONT WILL
STALL OVER THE REGION FRIDAY AND BECOME A WARM FRONT BY EVENING.
WITH AN INCREASING LLJ TO 50 KTS...THERE WILL BE VERY GOOD
MOISTURE CONVERGENCE SETTING UP ALONG THIS FRONT...LEADING TO SOME
HEAVY RAINS. UPPER LEVEL DIVERGENCE WILL BE INCREASING BY 00Z
FRIDAY...AND WITH THE RIGHT ENTRANCE REGION OF THE JET APPROACHING
THE DEEP LAYER SHEAR WILL INCREASE...ESPECIALLY ACROSS CENTRAL
LOWER MI. EVEN THE STRONG LLJ ALONE WOULD SUGGEST SOME DAMAGING
WIND POTENTIAL. GIVEN THE WARM FRONT NEARBY...A BOOST TO THE 0-1
KM STORM RELATIVE HELICITY CAN BE EXPECTED...AND THE ECMWF SHOWS
THIS NICELY WITH VALUES APPROACHING 200-250 M2/S2 BETWEEN 00Z-06Z
SAT. GIVEN RELATIVELY LOW CAPE...THE SEVERE WEATHER POTENTIAL
WILL NOT BE AS HIGH AS IT COULD BE. EVEN SO...INCREASING DEEP
LAYER SHEAR MAY HELP OFFSET THIS AND STILL SUPPORT SOME STRONG TO
SEVERE THUNDERSTORMS.
OUR MODEL BLENDED QPF FEATURES 1"-2" THROUGH SATURDAY. HOWEVER...
LOCALIZED HEAVY RAINFALL RATES OF 1"/HR OR MORE ARE QUITE
POSSIBLE GIVEN THE NATURE OF THIS SYSTEM (HIGH PW VALUES FOR MID
SEPTEMBER AND DEW POINTS CLIMBING INTO THE UPPER 60S). SOME
PONDING ON ROADS IS POSSIBLE OVERNIGHT AND MAYBE FOR THE MORNING
COMMUTE. FLOODING OF ROADS IN A SHORT TIME IS A THREAT
FRIDAY/FRIDAY NIGHT WHERE HEAVIER STORMS SET UP. THIS THREAT COULD
BE A GREATER HAZARD TO MOTORISTS AND IT MAY LINGER INTO SATURDAY
MORNING.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 320 PM EDT THU SEP 17 2015
I THINK WE WILL NEED TO WATCH THIS FORECAST CLOSELY IN THE COMING
DAYS. WILL MAINTAIN THE DRY PERIOD FOR NOW.
THE MAIN CONCERN IS THAT MODELS ARE IN DECENT AGREEMENT IN
KEEPING AN UPPER TROUGH OVERHEAD. THIS MAY SUPPORT SOME
INSTABILITY TYPE SHOWERS. AT THE SURFACE HIGH PRESSURE IS IN
PLACE. SUBSIDENCE WITH THIS FEATURE SHOULD LIMIT THE SHOWER/STORM
RISK.
SLOW MODERATION OF THE TEMPERATURES IS FORECASTED BECAUSE THE LOW
LEVEL THERMAL TROUGH GENERALLY STAYS IN PLACE. TEMPERATURES ARE
LIKELY TO END UP FAIRLY CLOSE TO SEASONABLE. THE WARMEST DAYS WILL
LIKELY BE BE THURSDAY AS A LOW LEVEL THERMAL RIDGE TRIES TO SET UP
OVER THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1136 PM EDT THU SEP 17 2015
RAIN AND SCATTERED THUNDERSTORMS WILL GRADUALLY MOVE IN FROM THE
WEST OVERNIGHT AND CAUSE CONDITIONS TO DETERIORATE FROM VFR TO
MVFR WITH POTENTIAL FOR POCKETS OF IFR CONDITIONS IN HEAVIEST
SHOWERS AND STORMS.
SHOWERS AND STORMS WILL GRADUALLY MOVE OUT MID TO LATE FRIDAY
MORNING. HOWEVER SCATTERED SHOWERS AND THUNDERSTORMS WILL
REDEVELOP FRIDAY AFTERNOON AND CONTINUE THROUGH FRIDAY EVENING.
A FEW STRONG THUNDERSTORMS WITH GUSTY WINDS AND HEAVY RAIN ARE
POSSIBLE FROM MID AFTERNOON FRIDAY THROUGH LATE FRIDAY EVENING.
CONDITIONS FRIDAY AFTERNOON AND EVENING WILL VARY GREATLY FROM
VFR TO A MIX OF MVFR/IFR IN SHOWERS AND STORMS.
&&
.MARINE...
ISSUED AT 750 PM EDT THU SEP 17 2015
WINDS AND WAVES WILL CONTINUE TO BE HAZARDOUS TO SMALL CRAFT
THROUGH TONIGHT...AND WILL INCREASE FRIDAY NIGHT WITH SOUTHWEST
GALES EXPECTED LATE FRIDAY NIGHT AND INTO SATURDAY. SOME STRONG
THUNDERSTORMS ARE POSSIBLE AS WELL LATE FRIDAY INTO EARLY
SATURDAY.
&&
.HYDROLOGY...
ISSUED AT 206 PM EDT THU SEP 17 2015
RAIN OF ONE TO TWO INCHES EXPECTED TONIGHT INTO SATURDAY MORNING...
AHEAD OF AND WITH A FRONTAL BOUNDARY EXPECTED TO STALL OVER THE
AREA. NO FLOODING ISSUES ARE EXPECTED THROUGH FRIDAY. LEVELS ARE
FALLING OR STEADY ON ALL AREA RIVERS. LOCALLY OVER 2 INCHES OF RAIN
ARE POSSIBLE AND MAY LEAD TO PONDING OF WATER IN SOUTHWEST LOWER
MICHIGAN FRIDAY INTO THE WEEKEND. ISOLATED AREAS MAY ALSO SEE SOME
STREET AND SMALL STREAM FLOODING.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT UNTIL 7 AM EDT FRIDAY FOR MIZ037-043-050-
056.
LM...GALE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY AFTERNOON FOR
LMZ844>849.
SMALL CRAFT ADVISORY UNTIL 7 AM EDT FRIDAY FOR LMZ846>849.
&&
$$
SYNOPSIS...HOVING
SHORT TERM...HOVING
LONG TERM...MJS
AVIATION...LAURENS
HYDROLOGY...63
MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
750 PM EDT THU SEP 17 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 320 PM EDT THU SEP 17 2015
MULTIPLE ROUNDS OF SHOWERS AND THUNDERSTORMS WILL MOVE THROUGH THE
REGION...STARTING AS EARLY AS THIS EVENING AND CONTINUING
OVERNIGHT. ANOTHER ROUND OF STORMS LOOKS LIKELY FRIDAY NIGHT INTO
SATURDAY MORNING WITH SOME HEAVY RAINS EXPECTED. SOME FLOODING
COULD OCCUR WHERE STORMS PERSIST. COOLER AND BREEZY CONDITIONS
MOVE IN SATURDAY BEFORE A WARMING TREND STARTS AGAIN.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 320 PM EDT THU SEP 17 2015
THE TWO PRIMARY RISKS TO EVALUATE THROUGH SATURDAY MORNING WILL BE
DAMAGING WIND GUST POTENTIAL ALONG WITH LOCALIZED FLOODING. FOR
THIS EVENING...ALMOST ALL NUMERICAL GUIDANCE IS STRUGGLING WITH
THE CONVECTION ACROSS NORTHERN IL. ONLY THE HRRR HAS A CLUE ABOUT
CONVECTIVE TRENDS AT THIS POINT AND SUGGESTS THE RAIN WILL PROCEED
ACROSS THE LAKE THIS EVENING AND WEAKEN A BIT...IN SPITE OF SPC
SREF-BASED EFFECTIVE BULK SHEAR INCREASING OVER THE LAKE (THOUGH
CIN WILL BE GROWING TOWARD NIGHTFALL). BUMPED POPS UP THIS EVENING
ESPECIALLY NEAR/WEST OF US 131 TO INCLUDE THIS THREAT FOR STORMS
IN CASE THEY SURVIVE THE TRIP OVER THE LAKE. NOT EXPECTING ANY
SEVERE WEATHER WITH THIS.
LATER TONIGHT...LOOKS LIKE A LINE OF STORMS WILL SOLIDIFY ACROSS
EASTERN WI IN THE MIDST OF A MID LEVEL SHORTWAVE APPROACHING BY
06Z AND A 40 KT LLJ ADVECTING MOISTURE INTO THE REGION. THIS LINE
FORMS ALONG A WEAK COLD FRONT WHICH WILL SLOW DOWN AND STALL OUT
OVER THE HEART OF THE CWA FRIDAY. RAIN CHANCES LOOK QUITE LIKELY
OVERNIGHT THOUGH INSTABILITY LOOKS WEAK OR NONEXISTENT FOR MOST
PLACES. WITH ONLY MODEST WINDS ACROSS THE COLUMN...WOULD EXPECT
LITTLE OR NO SEVERE WEATHER WITH THIS ACTIVITY OVERNIGHT. THE
BIGGER THREAT WOULD BE LOCALLY HEAVY DOWNPOURS...MAYBE UP TO AN
INCH IN SPOTS. AREAS THAT GET THE HEAVIEST RAIN WOULD BE FAVORED
FOR A FLOOD THREAT FRIDAY NIGHT GIVEN MOIST SOILS AND HENCE SOME
FAVORABLE ANTECEDENT CONDITIONS.
THE SEVERE WEATHER THREAT DOES GO UP FRIDAY...ESPECIALLY IN THE
EVENING AND LASTING THROUGH THE NIGHT. DAMAGING WIND GUSTS AND
SOME FLOODING ARE BOTH POTENTIAL HAZARDS. THE SFC COLD FRONT WILL
STALL OVER THE REGION FRIDAY AND BECOME A WARM FRONT BY EVENING.
WITH AN INCREASING LLJ TO 50 KTS...THERE WILL BE VERY GOOD
MOISTURE CONVERGENCE SETTING UP ALONG THIS FRONT...LEADING TO SOME
HEAVY RAINS. UPPER LEVEL DIVERGENCE WILL BE INCREASING BY 00Z
FRIDAY...AND WITH THE RIGHT ENTRANCE REGION OF THE JET APPROACHING
THE DEEP LAYER SHEAR WILL INCREASE...ESPECIALLY ACROSS CENTRAL
LOWER MI. EVEN THE STRONG LLJ ALONE WOULD SUGGEST SOME DAMAGING
WIND POTENTIAL. GIVEN THE WARM FRONT NEARBY...A BOOST TO THE 0-1
KM STORM RELATIVE HELICITY CAN BE EXPECTED...AND THE ECMWF SHOWS
THIS NICELY WITH VALUES APPROACHING 200-250 M2/S2 BETWEEN 00Z-06Z
SAT. GIVEN RELATIVELY LOW CAPE...THE SEVERE WEATHER POTENTIAL
WILL NOT BE AS HIGH AS IT COULD BE. EVEN SO...INCREASING DEEP
LAYER SHEAR MAY HELP OFFSET THIS AND STILL SUPPORT SOME STRONG TO
SEVERE THUNDERSTORMS.
OUR MODEL BLENDED QPF FEATURES 1"-2" THROUGH SATURDAY. HOWEVER...
LOCALIZED HEAVY RAINFALL RATES OF 1"/HR OR MORE ARE QUITE
POSSIBLE GIVEN THE NATURE OF THIS SYSTEM (HIGH PW VALUES FOR MID
SEPTEMBER AND DEW POINTS CLIMBING INTO THE UPPER 60S). SOME
PONDING ON ROADS IS POSSIBLE OVERNIGHT AND MAYBE FOR THE MORNING
COMMUTE. FLOODING OF ROADS IN A SHORT TIME IS A THREAT
FRIDAY/FRIDAY NIGHT WHERE HEAVIER STORMS SET UP. THIS THREAT COULD
BE A GREATER HAZARD TO MOTORISTS AND IT MAY LINGER INTO SATURDAY
MORNING.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 320 PM EDT THU SEP 17 2015
I THINK WE WILL NEED TO WATCH THIS FORECAST CLOSELY IN THE COMING
DAYS. WILL MAINTAIN THE DRY PERIOD FOR NOW.
THE MAIN CONCERN IS THAT MODELS ARE IN DECENT AGREEMENT IN
KEEPING AN UPPER TROUGH OVERHEAD. THIS MAY SUPPORT SOME
INSTABILITY TYPE SHOWERS. AT THE SURFACE HIGH PRESSURE IS IN
PLACE. SUBSIDENCE WITH THIS FEATURE SHOULD LIMIT THE SHOWER/STORM
RISK.
SLOW MODERATION OF THE TEMPERATURES IS FORECASTED BECAUSE THE LOW
LEVEL THERMAL TROUGH GENERALLY STAYS IN PLACE. TEMPERATURES ARE
LIKELY TO END UP FAIRLY CLOSE TO SEASONABLE. THE WARMEST DAYS WILL
LIKELY BE BE THURSDAY AS A LOW LEVEL THERMAL RIDGE TRIES TO SET UP
OVER THE REGION.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 750 PM EDT THU SEP 17 2015
VFR CONDITIONS ARE EXPECTED TONIGHT. SOME AREAS OF MVFR AND EVEN
IFR ARE POSSIBLE EARLY FRIDAY MORNING AS PATCHY LOW CLOUDS MOVE IN
BUT THE CHANCES OF IFR ARE DEEMED LOW ENOUGH TO LEAVE OUT OF THE
FORECAST FOR NOW. SOUTHWEST WINDS WILL PICK UP FRIDAY AFTERNOON
AND SHOWERS AND THUNDERSTORMS MAY BE MOVING IN BY LATE AFTERNOON.
&&
.MARINE...
ISSUED AT 750 PM EDT THU SEP 17 2015
WINDS AND WAVES WILL CONTINUE TO BE HAZARDOUS TO SMALL CRAFT
THROUGH TONIGHT...AND WILL INCREASE FRIDAY NIGHT WITH SOUTHWEST
GALES EXPECTED LATE FRIDAY NIGHT AND INTO SATURDAY. SOME STRONG
THUNDERSTORMS ARE POSSIBLE AS WELL LATE FRIDAY INTO EARLY
SATURDAY.
&&
.HYDROLOGY...
ISSUED AT 206 PM EDT THU SEP 17 2015
RAIN OF ONE TO TWO INCHES EXPECTED TONIGHT INTO SATURDAY MORNING...
AHEAD OF AND WITH A FRONTAL BOUNDARY EXPECTED TO STALL OVER THE
AREA. NO FLOODING ISSUES ARE EXPECTED THROUGH FRIDAY. LEVELS ARE
FALLING OR STEADY ON ALL AREA RIVERS. LOCALLY OVER 2 INCHES OF RAIN
ARE POSSIBLE AND MAY LEAD TO PONDING OF WATER IN SOUTHWEST LOWER
MICHIGAN FRIDAY INTO THE WEEKEND. ISOLATED AREAS MAY ALSO SEE SOME
STREET AND SMALL STREAM FLOODING.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT UNTIL 7 AM EDT FRIDAY FOR MIZ037-043-050-
056.
LM...GALE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY AFTERNOON FOR
LMZ844>849.
SMALL CRAFT ADVISORY UNTIL 7 AM EDT FRIDAY FOR LMZ846>849.
&&
$$
SYNOPSIS...HOVING
SHORT TERM...HOVING
LONG TERM...MJS
AVIATION...OSTUNO
HYDROLOGY...63
MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
353 PM EDT WED SEP 16 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 306 PM EDT WED SEP 16 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOWS THE UPPER GREAT LAKES
REGION BEING LOCATED BETWEEN AN UPPER RIDGE OVER THE EASTERN CONUS
AND AN UPPER TROUGH OVER THE WESTERN CONUS. THIS HAS LED TO
SOUTHWESTERLY FLOW ACROSS THE UPPER GREAT LAKES REGION AND THERE WAS
A WEAK SHORTWAVE THAT LIFTED NORTHEAST ACROSS THE AREA THIS MORNING.
THIS LED TO CLOUDS/SHOWERS AND EVEN A FEW THUNDERSTORMS OVER THE
WESTERN U.P. UNDER THE STEEP 700-300MB LAPSE RATES. THIS WAVE HAS
LIFTED TO THE NORTHEAST AND BROUGHT MUCH OF THE MID CLOUDS WITH
IT...ALTHOUGH THERE ARE STILL SOME LINGERING SHOWERS/SPRINKLES OVER
THE EAST AND NEAR DULUTH. THE THICKER MID CLOUDS DID HOLD OFF TEMPS
AND WINDS SOME THIS AFTERNOON BUT NOT THAT WE ARE SEEING MORE BREAKS
OVER THE WESTERN HALF OF THE CWA...TEMPERATURES HAVE RISEN INTO THE
UPPER 70S AND LOWER 80S. AS OF 3PM...NWS MARQUETTE IS JUST BELOW OUR
RECORD HIGH FOR TODAY (79) AND WOULD EXPECT THAT TO BE BROKEN IN THE
NEXT HOUR OR TWO. THE CLOUDS DID HELP LIMIT MIXING FROM REACHING THE
STRONGER WINDS ALOFT...BUT HAVE STILL BEEN SEEING 15-25KT WINDS OVER
MUCH OF THE AREA. EXPECT THE INCREASED SUNSHINE OVER THE NEXT COUPLE
HOURS TO LEAD TO SLIGHTLY HIGHER GUSTS THROUGH EARLY EVENING.
THE SURFACE LOW THAT IS CURRENTLY IN NORTHERN ONTARIO WILL CONTINUE
NORTHEAST THIS EVENING AND OVER NORTHERN JAMES BAY. THEN...ANOTHER
WAVE EJECTING NORTHEAST ACROSS EASTERN IDAHO WILL LEAD TO A
STRENGTHENING SURFACE LOW THAT IS CURRENTLY IN NORTHEAST WYOMING.
THIS LOW WILL LIFT NORTHEAST ACROSS THE DAKOTAS TONIGHT AND THEN
INTO NORTHERN ONTARIO ON THURSDAY. EXPECT PRECIPITATION CHANCES
TONIGHT INTO THURSDAY MORNING TO BE SIMILAR TO LAST NIGHT INTO THIS
MORNING WHERE THERE ARE STEEP 750-400MB LAPSE RATES IN PLACE AND
POCKETS OF MOISTURE OVER WESTERN LAKE SUPERIOR INTO FAR WESTERN
UPPER MICHIGAN. IN ADDITION...THERE IS A WEAK SHORTWAVE IN WESTERN
IOWA THAT LOOKS TO LIFT NORTHEAST THROUGH THE AREA. WITH THOSE
FEATURES BRUSHING THE WESTERN HALF OF THE CWA...WILL CONTINUE TO
SHOW SLIGHT CHANCE TO LOW END CHANCES FROM EAST TO WEST TOWARDS THE
MINNESOTA ARROWHEAD. WHILE THE DRY AIR BELOW 700MB WILL LIKELY LIMIT
THE MEASURABLE PRECIP IN SOME AREAS...FEEL THE SUPPORT IS THERE FOR
MEASURABLE RAIN TO OCCUR. ONCE AGAIN...EXPECT WINDS TO STAY UP
ACROSS THE AREA THROUGH THE NIGHT WITH THE STRONG LOW LEVEL JET (TO
45KTS) 2-3KFT ABOVE THE SURFACE. THOSE GUSTY WINDS WILL ALSO KEEP
TEMPERATURES WELL ABOVE THE NORMAL LOWS AND IN THE 60S WITH A FEW
70S OVER THE DOWNSLOPING AREAS OUT WEST.
HEADING INTO TOMORROW AFTERNOON...THE COLD FRONT TRAILING THE
SURFACE LOW LIFTING NORTHEAST FROM THE DAKOTAS INTO NORTHERN ONTARIO
THROUGH THE DAY WILL BE MOVING INTO WESTERN LAKE SUPERIOR DURING THE
LATE AFTERNOON AND EVENING HOURS. BELIEVE THE SHOWERS/THUNDERSTORMS
WILL BE LARGELY FOCUSED ALONG THE FRONT. BUT THERE ARE SOME HINTS AT
DEVELOPMENT OUT AHEAD OF THE FRONT AND TIED TO A SHORTWAVE LIFTING
NORTHEAST ACROSS THE WESTERN U.P. DURING THE AFTERNOON HOURS.
INSTABILITY WILL INCREASE OVER THE AREA WITH 1000-1500 J/KG OF
MLCAPE. BEST 0-6KM BULK SHEAR IS CONFINED TO THE AREAS IN IMMEDIATE
PROXIMITY OF THE FRONT...WITH THE REST OF THE AREA 20-25KT OUT AHEAD
OF THE FRONT. THAT WILL LEAD TO THE STRONGEST STORMS OCCURRING TO
THE WEST OF THE AREA IN THE AFTERNOON AND THEN TRYING TO SHIFT EAST
INTO THE U.P. DURING THE EVENING. WITH MORE CLOUD COVER
TOMORROW...HAVE LIMITED THE TEMPS TO THE UPPER 70S WITH A FEW LOWER
80S IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR. WIND GUSTS WILL ALSO
BE SIMILAR BUT SLIGHTLY LOWER AND ONCE AGAIN HAVE GUSTS IN THE 20-
25KT RANGE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 351 PM EDT WED SEP 16 2015
MAIN FCST CONCERNS IN THE LONGER TERM WL BE FOCUSED ON POPS/SEVERE
WX POTENTIAL THU NGT ASSOCIATED WITH COLD FROPA THAT WL BRING A
RETURN OF COOLER WX LATE THIS WEEK. ANOTHER CONCERN WL BE POPS LATE
FRI INTO SAT RELATED TO THE APRCH OF ANOTHER SHRTWV AND ITS
INTERACTION WITH STALLING FNT IN THE CENTRAL GREAT LKS. HI PRES AND
NEAR SEASONABLE TEMPS WL THEN DOMINATE LATE THIS WEEKEND.
THU NGT INTO FRI...LATEST MODEL GUIDANCE IS IN GOOD AGREEMENT
SHOWING SFC COLD FNT CROSSING THE UPR LKS THU NGT PASSING NEWBERRY
SOON AFTER 12Z FRI AND INTERACTING WITH WARM AIRMASS/PWAT NEAR 1.75
INCHES. SINCE NAM/GFS SDNGS INDICATE THE PRE FRONTAL AIRMASS WL BE
CAPPED...THE BULK OF SHOWERS/TS THAT FORM UNDER H7-5 LAPSE RATES AS
STEEP AS 7.5-8C/KM ARE LIKELY TO BE CLOSER TO THE SFC FNT. FCST
MUCAPES AS HI AS 1000-1500 J/KG...DEEP LYR SHEAR ABOUT 30-35KTS
ALONG THE FRONTAL BNDRY AND FCST DCAPES AS HI AS ABOUT 1000 J/KG
FOLLOWING THE WARM DAY ON THU SUPPORT THE MARGINAL/SLGT RISK FOR SVR
STORMS OUTLOOK FM SPC. RELATIVELY HI FRZG LVL FCST IN THE 12-14K
RANGE AND DEEP SATURATION SHOWN ON ESPECIALLY THE NAM FCST SDNGS AS
WELL AS PASSAGE OF STRONGER SHRTWV/HGT FALLS FARTHER TO THE N CLOSER
TO THE MAIN SHRTWV TRACK IN FAR NW ONTARIO ARE NEGATIVES. BEST CHC
FOR THE STRONGER STORMS SHOULD BE OVER THE W...WHERE THE ARRIVAL OF
THE FNT IN THE EVNG WOULD BE MORE IN SYNC WITH THE DAYTIME HEATING
CYCLE/HIER DCAPES. THE ARRIVAL OF DRIER/COOLER AIR BEHIND THE FROPA
WL BRING A DRYING TREND W-E LATER THU NGT INTO FRI...BUT SHALLOW
LLVL MSTR WITH INFLUX OF COOLER AIR BEHIND THE FNT/LO INVRN MAY LEAD
TO LINGERING LO CLDS INTO FRI MRNG...ESPECIALLY IN THE UPSLOPE AREAS
NEAR LK SUP.
FRI/SAT...ARRIVAL OF DRIER AIR/WEAK HI PRES RDG AND LLVL ACYC FLOW
WL RESULT IN A PERIOD OF DRY WX ON FRI AFTER LINGERING SHOWERS END
IN THE MRNG OVER THE E. BUT APRCH OF SHRTWV FM THE W IN MORE ZONAL
FLOW IN THE NRN PLAINS IS FCST TO CAUSE A SFC LO PRES TO DVLP ON FRI
AFTN IN IOWA ALONG STALLING COLD FNT STRETCHING FM THAT STATE INTO
LOWER MI UNDER MORE SW FLOW ALF ON NW FLANK OF UPR RDG PERSISTING IN
THE ERN CONUS. SOME OF THE MEDIUM RANGE GUIDANCE HAD INDICATED A
BAND OF PCPN ASSOCIATED WITH AXIS OF MID LVL FGEN WOULD IMPACT AT
LEAST PORTIONS OF THE CWA ON FRI AFTN WELL TO THE NE OF THIS
FEATURE...BUT DRYNESS OF THE MID LVL AIRMASS SHOWN ON THE 12Z NAM/
GFS FCST SDNGS SUG A DRY FCST IS WARRANTED AFTER THE FROPA SHOWERS
END OVER THE E IN THE MRNG. THERE ARE CONSIDERABLE MODEL DIFFERENCES
ON HOW QUICKLY AND TO WHAT EXTENT THE SFC LO IN IOWA WL INTENSIFY AS
IT TRACKS NE ON THE STALLED FNT INTO THE CENTRAL LKS. THE 12Z NAM IS
DEEPEST AND FARTHER W WITH THE TRACK OF THIS SYSTEM...SHOWING
WIDESPREAD RA IMPACTING ALL OF UPR MI THRU THE DAY ON SAT WITH
FAIRLY SHARP CYC NE FLOW LEADING TO A VERY CHILLY DAY AS WELL. THE
00Z CNDN/ECMWF RUNS ON THE OTHER HAND SHOWED A RELATIVELY WEAK SFC
LO MOVING QUICKLY TO THE NE...WITH LIGHTER PCPN ENDING SOON AFTER
12Z SAT. ALTHOUGH THE INCOMING SHRTWV IS RATHER IMPRESSIVE...WITH
00Z-12Z SAT H5 HGT FALLS FCST UP TO 100M EVEN WITH THE WEAKER ECWMF
FCST...AND MODEL TRENDS SUPPORT THE NAM FCST...PREFER TO FOLLOW A
COMPROMISE BTWN THE SOMEWHAT DEEPER 12Z GFS/CNDN/ECMWF MODEL FCSTS
AND THE WEAKER/FASTER SCENARIO SHOWN BY THE 00Z ECMWF/CNDN AND 09Z
SREF. NCEP GUIDANCE ALSO INDICATES A PREFERENCE FOR REJECTING THE
DEEPER 12Z NAM FCST. THE PREFERRED MODELS SHOW THE HIER CATEGORICAL/
LIKELY POPS OVER ALL BUT THE WRN CWA...WHERE CHC POPS APPEAR MORE
APPROPRIATE FARTHEST FM THE STALLED BNDRY TO THE SE. THIS SCENARIO
WL ALSO SUPPORT A STEADY DRYING TREND W-E ON SAT...WITH PCPN ENDING
OVER THE FAR E BY EARLY/MID AFTN.
SAT NGT INTO TUE...HI PRES TRAILING THE DEPARTING SFC LO PRES IS
FCST TO BUILD INTO THE LOWER GREAT LKS BY 12Z SUN...THE NE STATES AT
12Z MON AND THEN OVER THE CNDN MARITIMES ON TUE. DRY ACYC SW FLOW
ARND THIS FEATURE WL DOMINATE UPR MI DURING THIS TIME AND BRING A
PERIOD OF DRY WX. ALTHOUGH PWAT FALLING TOWARD 0.5 INCH AT 12Z SUN
WOULD SUPPORT SOME CHILLY OVERNGT LOWS...STEADY WSW FLOW ON THE NRN
FLANK OF HI PRES CENTER TO THE S MAY TEND TO LIMIT THE POTENTIAL FOR
COLDER TEMPS/FROST...ESPECIALLY OVER THE NW HALF UNDER TIGHTER PRES
GRADIENT. H85 TEMPS ARE FCST TO SLOWLY MODERATE THRU THIS TIME...
RISING FM ARND 8C ON SUN TO ARND 10C ON MON AND THEN 12C ON TUE...
SUPPORTING A SLOW WARMING TREND THAT WL FEATURE MEAN DAILY TEMPS
RISING FM NEAR NORMAL ON SUN TO AT LEAST A BIT ABOVE NORMAL AGAIN ON
MON/TUE.
TUE/WED...SHRTWV MOVING THRU ZONAL FLOW OVER CENTRAL CANADA IS FCST
TO DRAG A COLD FNT THRU THE UPR LKS LATE TUE/TUE NGT. SINCE THERE
ARE TIMING DIFFERENCES AND THE LONGER RANGE GUIDANCE HINTS MSTR
INFLOW WL BE SOMEWHAT LIMITED TO THE S OF SHARPER HGT FALLS TO THE
N...NO MORE THAN LO CHC POPS ARE NECESSARY AT THIS POINT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 143 PM EDT WED SEP 16 2015
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD WITH GUSTY
SOUTH-SOUTHWESTERLY WINDS. THE GUSTY WINDS WILL WEAKEN SLIGHTLY
TONIGHT AND LEAD TO THE POTENTIAL FOR LLWS AT ALL THREE SITES.
THOUGH KSAW/KIWD WOULD HAVE THE BEST CHANCE FOR THE WINDS TO STAY
UP AND HAVE LEFT LLWS OUT AT THOSE SITES. A DISTURBANCE WILL PUSH
ACROSS WESTERN LAKE SUPERIOR LATE TONIGHT AND IT COULD BRUSH KIWD.
THEN...SHOWERS WILL INCREASE FROM WEST TO EAST DURING THE AFTERNOON
AND EVENING AS A COLD FRONT SWEEPS ACROSS THE AREA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 306 PM EDT WED SEP 16 2015
GUSTY SOUTHERLY WINDS WILL REMAIN IN PLACE OVER THE NEXT 24-30
HOURS AS THE UPPER GREAT LAKES REGION IS BETWEEN HIGH PRESSURE IN
THE MID ATLANTIC STATES AND A COUPLE LOWS THAT WILL BE MOVING
NORTHEAST ACROSS ONTARIO. THESE SOUTHERLY WINDS WILL GENERALLY BE
IN THE 15-25KT RANGE...BUT WITH VERY STRONG WINDS JUST ABOVE THE
SURFACE...COULD SEE SOME STRONGER GUSTS TO 30KTS AT TIMES OVER
EASTERN LAKE SUPERIOR. A COLD FRONT MOVING EAST ACROSS LAKE
SUPERIOR ON THURSDAY NIGHT WILL SHIFT WINDS TO THE NORTHWEST UP TO
25KTS. THE WINDS WILL DIMINISH THROUGH THE DAY ON FRIDAY AS A HIGH
PRESSURE RIDGE QUICKLY BUILDS INTO THE AREA. ON FRIDAY NIGHT...A
SURFACE LOW WILL DEVELOP ALONG THE COLD FRONT THAT MOVED THROUGH ON
THURSDAY NIGHT AND MOVE THROUGH LOWER MICHIGAN. THIS WILL SHIFT
WINDS MORE OUT OF THE NORTHERLY DIRECTION UP TO 25 KNOTS LATE
FRIDAY NIGHT INTO SATURDAY MORNING. A LARGE HIGH PRESSURE RIDGE
WILL BUILD OVER THE GREAT LAKES REGION SATURDAY NIGHT AND REMAIN
INTO MONDAY AND KEEP WINDS BELOW 20KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
306 PM EDT WED SEP 16 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 306 PM EDT WED SEP 16 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOWS THE UPPER GREAT LAKES
REGION BEING LOCATED BETWEEN AN UPPER RIDGE OVER THE EASTERN CONUS
AND AN UPPER TROUGH OVER THE WESTERN CONUS. THIS HAS LED TO
SOUTHWESTERLY FLOW ACROSS THE UPPER GREAT LAKES REGION AND THERE WAS
A WEAK SHORTWAVE THAT LIFTED NORTHEAST ACROSS THE AREA THIS MORNING.
THIS LED TO CLOUDS/SHOWERS AND EVEN A FEW THUNDERSTORMS OVER THE
WESTERN U.P. UNDER THE STEEP 700-300MB LAPSE RATES. THIS WAVE HAS
LIFTED TO THE NORTHEAST AND BROUGHT MUCH OF THE MID CLOUDS WITH
IT...ALTHOUGH THERE ARE STILL SOME LINGERING SHOWERS/SPRINKLES OVER
THE EAST AND NEAR DULUTH. THE THICKER MID CLOUDS DID HOLD OFF TEMPS
AND WINDS SOME THIS AFTERNOON BUT NOT THAT WE ARE SEEING MORE BREAKS
OVER THE WESTERN HALF OF THE CWA...TEMPERATURES HAVE RISEN INTO THE
UPPER 70S AND LOWER 80S. AS OF 3PM...NWS MARQUETTE IS JUST BELOW OUR
RECORD HIGH FOR TODAY (79) AND WOULD EXPECT THAT TO BE BROKEN IN THE
NEXT HOUR OR TWO. THE CLOUDS DID HELP LIMIT MIXING FROM REACHING THE
STRONGER WINDS ALOFT...BUT HAVE STILL BEEN SEEING 15-25KT WINDS OVER
MUCH OF THE AREA. EXPECT THE INCREASED SUNSHINE OVER THE NEXT COUPLE
HOURS TO LEAD TO SLIGHTLY HIGHER GUSTS THROUGH EARLY EVENING.
THE SURFACE LOW THAT IS CURRENTLY IN NORTHERN ONTARIO WILL CONTINUE
NORTHEAST THIS EVENING AND OVER NORTHERN JAMES BAY. THEN...ANOTHER
WAVE EJECTING NORTHEAST ACROSS EASTERN IDAHO WILL LEAD TO A
STRENGTHENING SURFACE LOW THAT IS CURRENTLY IN NORTHEAST WYOMING.
THIS LOW WILL LIFT NORTHEAST ACROSS THE DAKOTAS TONIGHT AND THEN
INTO NORTHERN ONTARIO ON THURSDAY. EXPECT PRECIPITATION CHANCES
TONIGHT INTO THURSDAY MORNING TO BE SIMILAR TO LAST NIGHT INTO THIS
MORNING WHERE THERE ARE STEEP 750-400MB LAPSE RATES IN PLACE AND
POCKETS OF MOISTURE OVER WESTERN LAKE SUPERIOR INTO FAR WESTERN
UPPER MICHIGAN. IN ADDITION...THERE IS A WEAK SHORTWAVE IN WESTERN
IOWA THAT LOOKS TO LIFT NORTHEAST THROUGH THE AREA. WITH THOSE
FEATURES BRUSHING THE WESTERN HALF OF THE CWA...WILL CONTINUE TO
SHOW SLIGHT CHANCE TO LOW END CHANCES FROM EAST TO WEST TOWARDS THE
MINNESOTA ARROWHEAD. WHILE THE DRY AIR BELOW 700MB WILL LIKELY LIMIT
THE MEASURABLE PRECIP IN SOME AREAS...FEEL THE SUPPORT IS THERE FOR
MEASURABLE RAIN TO OCCUR. ONCE AGAIN...EXPECT WINDS TO STAY UP
ACROSS THE AREA THROUGH THE NIGHT WITH THE STRONG LOW LEVEL JET (TO
45KTS) 2-3KFT ABOVE THE SURFACE. THOSE GUSTY WINDS WILL ALSO KEEP
TEMPERATURES WELL ABOVE THE NORMAL LOWS AND IN THE 60S WITH A FEW
70S OVER THE DOWNSLOPING AREAS OUT WEST.
HEADING INTO TOMORROW AFTERNOON...THE COLD FRONT TRAILING THE
SURFACE LOW LIFTING NORTHEAST FROM THE DAKOTAS INTO NORTHERN ONTARIO
THROUGH THE DAY WILL BE MOVING INTO WESTERN LAKE SUPERIOR DURING THE
LATE AFTERNOON AND EVENING HOURS. BELIEVE THE SHOWERS/THUNDERSTORMS
WILL BE LARGELY FOCUSED ALONG THE FRONT. BUT THERE ARE SOME HINTS AT
DEVELOPMENT OUT AHEAD OF THE FRONT AND TIED TO A SHORTWAVE LIFTING
NORTHEAST ACROSS THE WESTERN U.P. DURING THE AFTERNOON HOURS.
INSTABILITY WILL INCREASE OVER THE AREA WITH 1000-1500 J/KG OF
MLCAPE. BEST 0-6KM BULK SHEAR IS CONFINED TO THE AREAS IN IMMEDIATE
PROXIMITY OF THE FRONT...WITH THE REST OF THE AREA 20-25KT OUT AHEAD
OF THE FRONT. THAT WILL LEAD TO THE STRONGEST STORMS OCCURRING TO
THE WEST OF THE AREA IN THE AFTERNOON AND THEN TRYING TO SHIFT EAST
INTO THE U.P. DURING THE EVENING. WITH MORE CLOUD COVER
TOMORROW...HAVE LIMITED THE TEMPS TO THE UPPER 70S WITH A FEW LOWER
80S IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR. WIND GUSTS WILL ALSO
BE SIMILAR BUT SLIGHTLY LOWER AND ONCE AGAIN HAVE GUSTS IN THE 20-
25KT RANGE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 504 AM EDT WED SEP 16 2015
CURRENT WRN CONUS TROF AND ERN CONUS RIDGE WILL GIVE WAY TO LOWER
AMPLITUDE FLOW BY LATE THIS WEEKEND AS A PAIR OF SHORTWAVES HELP
SHIFT THE DEAMPLIFYING WRN TROF EASTWARD. THE FIRST WAVE WILL LIFT
INTO NRN ONTARIO THU NIGHT WITH THE FOLLOWING SHIFTING ACROSS THE
GREAT LAKES REGION SAT. THESE CHANGES WILL RESULT IN WELL ABOVE
NORMAL TEMPS FALLING BACK TO NEAR NORMAL BY EARLY THIS WEEKEND.
WARMING WILL BEGIN AGAIN EARLY NEXT WEEK UNDER LOW AMPLITUDE FLOW
FEATURING BLO NORMAL HEIGHTS IN WRN CANADA AND ABOVE NORMAL HEIGHTS
FROM THE MISSISSIPPI VALLEY TO SE CANADA. LOOKING FARTHER
OUT...LONGER RANGE GUIDANCE POINTS TO ABOVE NORMAL TEMPS BEING
FAVORED ON THE MAJORITY OF DAYS FOR AT LEAST THE NEXT 2 WEEKS. AS
FOR PCPN OVER THE NEXT 7 DAYS...THE BEST POTENTIAL FOR PCPN WILL
OCCUR THU AFTN/NIGHT AS COLD FRONT SWEEPS ACROSS THE UPPER GREAT
LAKES IN ASSOCIATION WITH FIRST SHORTWAVE NOTED ABOVE. ANOTHER SHOT
OF PCPN COULD OCCUR LATE FRI INTO EARLY SAT IN ASSOCIATION WITH
SECOND SHORTWAVE AS IT SUPPORTS A SFC WAVE TRACKING NE ALONG COLD
FRONT THAT PASSED THU NIGHT. THE SE PORTION OF THE FCST AREA WILL
HAVE THE BEST CHC OF SEEING PCPN WITH THE SECOND SHORTWAVE.
THU THRU FRI MORNING...COLD FRONT WILL LIKELY REACH FAR WRN UPPER MI
EARLY THU EVENING AND EXIT THE ERN FCST AREA EARLY FRI MORNING. WITH
CAPPING OUT AHEAD OF FRONT DUE TO THE CONTINUED ELEVATED MIXED LAYER
OVER THE AREA...CONVECTION SHOULD BE CONFINED FAIRLY CLOSE TO THE
COLD FRONT. BASED ON LATEST MODEL RUNS...INHERITED FCST APPEARS TO
HAVE A GOOD HANDLE ON THE TIMING OF THE POPS AS THE FRONT MOVES
ACROSS THE AREA. ONLY MINOR ADJUSTMENTS WERE NECESSARY. NAM/GFS
GENERALLY SHOW MLCAPES OVER 1000J/KG INTO WRN UPPER MI AHEAD FRONT
LATE AFTN/EARLY EVENING...BUT DEEP LAYER SHEAR IN EXCESS OF 30KT
LAGS MOSTLY BEHIND THE AXIS OF MAX INSTABILITY. THIS WILL LIMIT SVR
TSTM RISK TO SOME DEGREE. SPC OUTLOOK FOR A MARGINAL RISK OVER WRN
UPPER MI SEEMS APPROPRIATE....BUT WITH COLD FRONT PASSING ACROSS THE
REST OF THE AREA DURING THE COOLING CYCLE...SVR TSTM RISK SHOULD
BECOME INCREASINGLY LIMITED INTO CNTRL UPPER MI. ANY LINGERING SHRA
OVER THE E FRI MORNING WILL END EARLY AS FRONT EXITS. THU WILL BE
THE LAST WARM DAY OF THIS STRING. EXPECT HIGHS IN THE 70S WITH LWR
80S IN DOWNSLOPE AREAS NEAR LAKE SUPERIOR.
ATTENTION THEN TURNS TO NEXT SHORTWAVE THAT WILL REACH THE WRN GREAT
LAKES FRI NIGHT. SHORTWAVE WILL SPIN UP A SFC WAVE ALONG THE COLD
FRONT THAT PASSED THU NIGHT. THAT LOW WILL TRACK NE ACROSS LWR MI.
THE NAM IS A STRONG/SLOW OUTLIER AND HAS SFC LOW TRACK/HEAVIER PCPN
FARTHER W THAN OTHER GUIDANCE. IT WAS DISCARDED. WITH REST OF
GUIDANCE SHOWING COLD FRONT SETTLING SW TO NE ACROSS LWR MI BY THE
TIME THE SFC WAVE DEVELOPS...THE MAIN PCPN...ESPECIALLY HEAVIER
PCPN...WILL STAY SE OF THE FCST AREA. RIGHT ENTRANCE OF UPPER JET
EXTENDING FROM THE UPPER MISSISSIPPI VALLEY TO JAMES BAY AND QUEBEC
WILL PROBABLY AID -SHRA DEVELOPMENT FARTHER W INTO UPPER MI. PCPN
MAY ARRIVE AS EARLY AS LATE FRI AFTN ACROSS THE SCNTRL/E WHERE SCHC
POPS WERE UTILIZED. OTHERWISE...FCST WILL SHOW CHC POPS ACROSS
ROUGHLY THE SE HALF OF THE FCST AREA FRI NIGHT. THE FAR W WILL
LIKELY REMAIN DRY. MODEL TRENDS ARE FOR A QUICKER DEPARTURE OF SFC
WAVE TO THE NE ON SAT...SO FCST WILL TREND TO DRY WEATHER SOONER.
ALL PCPN SHOULD BE OUT OF THE AREA BY AFTN. TEMPS FRI WILL BE CLOSER
TO NORMAL...MAINLY IN THE 60S TO AROUND 70F. SAT WILL BE THE COOLEST
DAY WITH HIGHS 60-65F.
DEPENDING ON HOW QUICKLY SFC HIGH PRES MOVES ACROSS THE WRN GREAT
LAKES SAT NIGHT/SUN...THERE WILL BE THE POTENTIAL FOR A DECENT
RADIATIONAL COOLING NIGHT SAT NIGHT. FOR NOW...LOWERED TEMPS TO THE
UPPER 30S AT TRADITIONAL COLD SPOTS...NOT COLD ENOUGH FOR FROST
MENTION YET.
DRY WEATHER/WARMING WILL BE THE RULE SUN THRU TUE WITH SW FLOW
DEVELOPING AS HIGH PRES SHIFTS TO NEW ENGLAND AND A LOW PRES TROF
EVENTUALLY MOVES OUT ACROSS THE NRN PLAINS TOWARD THE UPPER LAKES.
EACH DAY...AFTN HIGH TEMPS WILL BE A LITTLE HIGHER THAN THE PREVIOUS
DAY...REACHING THE LOW/MID 70S OVER MOST OF THE AREA BY TUE.
APPROACHING SFC TROF MAY BRING THE POTENTIAL FOR SHRA AGAIN AT SOME
POINT LATER TUE INTO WED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 143 PM EDT WED SEP 16 2015
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD WITH GUSTY
SOUTH-SOUTHWESTERLY WINDS. THE GUSTY WINDS WILL WEAKEN SLIGHTLY
TONIGHT AND LEAD TO THE POTENTIAL FOR LLWS AT ALL THREE SITES.
THOUGH KSAW/KIWD WOULD HAVE THE BEST CHANCE FOR THE WINDS TO STAY
UP AND HAVE LEFT LLWS OUT AT THOSE SITES. A DISTURBANCE WILL PUSH
ACROSS WESTERN LAKE SUPERIOR LATE TONIGHT AND IT COULD BRUSH KIWD.
THEN...SHOWERS WILL INCREASE FROM WEST TO EAST DURING THE AFTERNOON
AND EVENING AS A COLD FRONT SWEEPS ACROSS THE AREA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 306 PM EDT WED SEP 16 2015
GUSTY SOUTHERLY WINDS WILL REMAIN IN PLACE OVER THE NEXT 24-30
HOURS AS THE UPPER GREAT LAKES REGION IS BETWEEN HIGH PRESSURE IN
THE MID ATLANTIC STATES AND A COUPLE LOWS THAT WILL BE MOVING
NORTHEAST ACROSS ONTARIO. THESE SOUTHERLY WINDS WILL GENERALLY BE
IN THE 15-25KT RANGE...BUT WITH VERY STRONG WINDS JUST ABOVE THE
SURFACE...COULD SEE SOME STRONGER GUSTS TO 30KTS AT TIMES OVER
EASTERN LAKE SUPERIOR. A COLD FRONT MOVING EAST ACROSS LAKE
SUPERIOR ON THURSDAY NIGHT WILL SHIFT WINDS TO THE NORTHWEST UP TO
25KTS. THE WINDS WILL DIMINISH THROUGH THE DAY ON FRIDAY AS A HIGH
PRESSURE RIDGE QUICKLY BUILDS INTO THE AREA. ON FRIDAY NIGHT...A
SURFACE LOW WILL DEVELOP ALONG THE COLD FRONT THAT MOVED THROUGH ON
THURSDAY NIGHT AND MOVE THROUGH LOWER MICHIGAN. THIS WILL SHIFT
WINDS MORE OUT OF THE NORTHERLY DIRECTION UP TO 25 KNOTS LATE
FRIDAY NIGHT INTO SATURDAY MORNING. A LARGE HIGH PRESSURE RIDGE
WILL BUILD OVER THE GREAT LAKES REGION SATURDAY NIGHT AND REMAIN
INTO MONDAY AND KEEP WINDS BELOW 20KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
131 AM EDT WED SEP 16 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 321 PM EDT TUE SEP 15 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WRN TROF/ERN RDG
PATTERN...WITH DEEP SW FLOW ARND SFC HI PRES IN THE MID ATLANTIC
STATES ADVECTING UNSEASONABLY WARM AIR INTO THE UPR GREAT LKS. 12Z
H85 TEMPS WERE 18C AT APX/GRB AND 19C AT MPX. DESPITE STEEP MID LVL
LAPSE RATES AND SOME MODEST H85 THETA E ADVECTION THAT SUPPORTED
SOME SCT SHOWERS/TS OVER NE WI EARLIER THIS MRNG...ABSENCE OF
DYNAMIC FORCING WITH LLVL ACYC FLOW AND VERY SHARP CAPPING/DRY MID
LYR DEPICTED ON THE 12Z MPX RAOB THAT ARE OVERSPREADING THE AREA
HAVE MAINTAINED DRY WX OVER UPR MI. SFC TEMPS HAVE RISEN INTO THE
80S AT MANY PLACES AWAY FM LK MI MODERATION DESPITE SOME PATCHY HI
CLDS.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON TEMPS/WINDS AND SLIM
PCPN CHCS.
TNGT...STRONG SW FLOW...WITH SHARPENING PRES GRADIENT INCRSG H925
WINDS UP TO 40-45 KTS...IS FCST TO DOMINATE THE AREA. NOCTURNAL
COOLING/INVRN WL LIMIT THE SFC WIND GUSTS. ALTHOUGH THESE STRONG
WINDS WL INITIALLY TAP AN AREA OF DRIER LLVL AIR NOW OVER THE LOWER
GREAT LKS...MODELS SHOW THE H85 FLOW VEERING A BIT OVERNGT AND
ADVECTING HIER H85-7 THETA E INTO MAINLY THE NW HALF OF UPR MI
OVERNGT. A NUMBER OF THE MODELS GENERATE SOME PCPN IN THIS AREA
LATE. BUT CONSIDERING THE STRONG CAPPING DEPICTED ON THE 12Z MPX
RAOB...THE ABSENCE OF ANY OTHER SGNFT DYNAMIC FORCING/HGT FALLS AND
RELATIVELY DRY SFC-H7 LYR SHOWN ON THE 12Z NAM FCST SDNGS...OPTED TO
FOLLOW THE DRIER GUIDANCE AND MAINTAIN GOING DRY FCST. THE
COMBINATION OF STRONG WINDS AND INCRSG MID/HI CLDS ACCOMPANYING THE
MSTR RETURN WL RESULT IN A VERY WARM OVERNGT...ESPECIALLY IN THE
DOWNSLOPE AREAS NEAR LK SUP OVER THE NW HALF...WHERE FCST WL TEND
TOWARD THE HI END OF GUIDANCE.
WED...MAINTAINED SOME SCHC POPS OVER THE FAR NW CWA...WHERE SHRTWV
FCST TO LIFT NE THRU FAR NW ONTARIO MAY BE CLOSE ENUF TO AXIS OF
HIER H85-7 THETA E TO GENERATE SOME SHOWERS/TS. THE REST OF THE CWA
WL REMAIN DRY. DAYTIME HEATING/MIXING WL CAUSE THE STRONG LLVL WINDS
TO MIX TO THE SFC...WITH GUSTS AS HI AS 30 TO 35 MPH AT THE MORE
EXPOSED LOCATIONS. WITH H85 TEMPS FCST AS HI AS 20-22C...EXPECT MAX
TEMPS TO CLIMB WELL INTO THE 80S AWAY FM THE COOLING INFLUENCE OF LK
MI. TENDED TOWARD THE HI END OF GUIDANCE FOR MAX TEMPS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 343 PM EDT TUE SEP 15 2015
A COLD FRONT THAT WILL MOVE ACROSS THE AREA LATE THURSDAY AFTERNOON
AND THURSDAY NIGHT WILL START A BRIEF PERIOD OF NORMAL TO BELOW
NORMAL TEMPERATURES...BEFORE TRENDING BACK ABOVE NORMAL FOR EARLY
NEXT WEEK. AHEAD OF THE COLD FRONT...MODELS ARE CONTINUING TO PAINT
ISOLATED TO SCATTERED SHOWERS OVER WESTERN LAKE SUPERIOR AND
PORTIONS OF THE WESTERN U.P. WEDNESDAY NIGHT INTO THURSDAY MORNING
UNDER THE SOUTHWESTERLY FLOW WARM AIR ADVECTION...STEEP 750-400MB
LAPSE RATES AND OCCASIONAL EMBEDDED SHORTWAVES. MOISTURE LOOKS TO
BE THE MAIN LIMIT AT THIS POINT...BUT WILL CONTINUE TO SHOW SLIGHT
TO LOW CHANCE POPS IN THAT AREA AS ANY LITTLE BIT OF MOISTURE WILL
BE ABLE TO PRODUCE SOME SHOWERS. THE DRY LOW LEVEL AIR WILL LIKELY
LIMIT THE WEAKER SHOWERS FROM REACHING THE GROUND. CLOUDS AHEAD OF
THE COLD FRONT WILL LEAD TO SLIGHTLY COOLER HIGHS ON THURSDAY...BUT
STILL EXPECT THEM TO BE ABOVE NORMAL AND IN THE 70S WITH A FEW
LOWER 80S IN THE FAVORED DOWNSLOPE AREAS NEAR LAKE SUPERIOR.
FOR THE COLD FRONT PASSAGE THURSDAY AFTERNOON INTO THURSDAY
NIGHT...NOT A WHOLE LOT HAS CHANGED OVER THE LAST 24 HOURS AND THE
GOING FORECAST HAS A GOOD HANDLE ON THE TIMING OF THE POPS AS THE
FRONT MOVES THROUGH. ONLY MADE MINOR TWEAKS TO THE TIMING OF THE
POPS AND EXPECT CAPPING OUT AHEAD OF THE FRONT WILL LIKELY
CONFINE MUCH OF THE SHOWERS/THUNDERSTORMS TO RIGHT ALONG THE FRONT.
AS HAS BEEN MENTIONED IN PREVIOUS DISCUSSIONS...THERE IS THE
POTENTIAL FOR MARGINALLY SEVERE STORMS OVER THE WESTERN CWA AND FEEL
THE MARGINAL RISK IN THE DAY 3 SPC OUTLOOK IS FAIRLY REASONABLE.
THE FRONT WILL QUICKLY DEPART EARLY FRIDAY MORNING AND HAVE TRENDED
THE DEPARTURE OF THE PRECIPITATION A LITTLE FASTER THAN THE
PREVIOUS FORECAST. SHOULD SEE PARTLY TO MOSTLY CLEAR SKIES
IMMEDIATELY BEHIND THE FRONT AS A SURFACE RIDGE MOVES IN AHEAD OF
THE NEXT SHORTWAVE ARRIVING FROM THE SOUTHWEST (AND INCREASING
MID-HIGH CLOUDS IN THE AFTERNOON). HIGHS ON FRIDAY WILL RETURN TO
MORE NORMAL VALUES FOR MID SEPTEMBER (60S).
THE COLD FRONT WILL STALL OVER LOWER MICHIGAN LATE FRIDAY AFTERNOON
INTO FRIDAY EVENING AS A ANOTHER SHORTWAVE MOVES EAST OUT OF THE
NORTHERN/CENTRAL PLAINS. A SURFACE LOW WILL DEVELOP ALONG THE FRONT
AS IT MOVES TOWARDS THE GREAT LAKES REGION BEFORE LIFTING ACROSS
NORTHERN LAKE/LOWER MICHIGAN LATE FRIDAY NIGHT INTO SATURDAY
MORNING. THE SHORTWAVE WILL COMBINE WITH THE STALLED FRONT TO FOCUS
MODERATE TO OCCASIONALLY HEAVY RAIN TO THE SOUTHEAST OF THE
AREA...BUT STILL EXPECT AT LEAST THE SOUTHEAST HALF TO 2/3RDS OF THE
CWA TO SEE A TENTH OF AN INCH OF RAIN ON THE NORTHWEST SIDE OF THE
PRECIPITATION SHIELD. CONTINUED TO TREND POPS UP IN THAT AREA AND
HAVE VALUES NEAR LIKELIES ALONG THE LAKE MICHIGAN SHORELINE FOR
LATE FRIDAY NIGHT. THE SHORTWAVE WILL DEPART AND HIGH PRESSURE WILL
QUICKLY BUILD INTO THE AREA ON SATURDAY...RAPIDLY ENDING THE RAIN
FROM WEST TO EAST ON SATURDAY MORNING. A BRIEF SHOT OF COLDER AIR
WILL BE IN PLACE ON SATURDAY AND WITH THE BREEZY NORTHERLY
WINDS...THE LOWER 60S HIGHS WILL FEEL MUCH COOLER THAN THE LAST
COUPLE OF DAYS. FORTUNATELY...INCREASING SUNSHINE DURING THE
AFTERNOON SHOULD HELP OFFSET THE COOLER TEMPERATURES. THE HIGH THAT
WILL BUILD IN ON SATURDAY WILL REMAIN IN PLACE INTO MONDAY NIGHT
AND LEAD TO DRY CONDITIONS. THERE ARE HINTS OF A WEAK FRONT MOVING
ACROSS THE AREA ON TUESDAY...BUT WITH MUCH OF THE FORCING STAYING
WELL TO THE NORTH OF THE AREA...WILL GO WITH SILENT 20 POPS FOR
THE WESTERN CWA FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 129 AM EDT WED SEP 16 2015
SOME ISOLD HIGH BASED SHRA/TSRA ARE EXPECTED OVR THE WESTERN HALF OF
UPPER MICHIGAN OVERNIGHT. HOWEVER...CONFIDENCE THAT THEY WILL IMPACT
THE TAF SITES IS TOO LOW TO INCLUDE MENTION ATTM.
A STRENGTHENING SSW WIND WL DOMINATE THIS FORECAST PERIOD BEWEEN
HIGH PRESSURE OVER THE MID ATLANTIC AND LOW PRES IN THE HIGH PLAINS.
THE SFC WIND GUSTS WILL BE STRONGEST AT THE MORE EXPOSED IWD AND SAW
LOCATIONS. ALTHOUGH THE STRONGEST WINDS WILL OCCUR DURING THE
DAYLIGHT HRS...THE PRES GRADIENT WL BE STRONG ENOUGH TO CAUSE GUSTY
WINDS AT IWD THRGOUTH THE NIGHT.
AT THE MORE SHELTERED CMX SITE...LLWS IS EXPECTED OVERNIGHT WITH A
NOCTURNAL INVERSION BELOW THE AXIS OF STRONGEST WINDS. THE FORECAST
FOR SAW IS LESS CERTAIN AS THERE MAY BE PERIODS OF GUSTY WINDS AS
WELL TONIGHT. BUT MAINTAINED FCST LLWS THERE TONIGHT AS THE NEAR SFC
STABILITY SHOULD BE ENOUGH TO LIMIT MIXING.
ALTHOUGH THERE WILL BE MORE MID AND HIGH CLOUDS LATER TONIGHT AND
WED MORNING ESPECIALLY OVER THE NW HALF OF UPPER MI...LINGERING LOW
LEVEL DRY AIR WILL RESULT IN VFR CONDITIONS THE ENTIRE FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 349 PM EDT TUE SEP 15 2015
WINDY CONDITIONS ARE SHAPING UP FOR MUCH OF LAKE SUPERIOR INTO WED
AS THE UPPER LAKES WILL BE SITUATED BTWN A LO PRES TROF TO THE NW
AND HI PRES OVER THE MID ATLANTIC STATES. EXPECT S WINDS TO INCREASE
TO AS HI AS 25-30 KTS TONIGHT INTO WED. NOT OUT OF THE QUESTION THAT
THE HIGHEST OBS PLATFORMS WILL SEE GALE FORCE GUSTS...ESPECIALLY
OVER THE E HALF. WINDS WILL DIMINISH A BIT WED AFTERNOON/THU...
ESPECIALLY OVER THE W HALF OF THE LAKE. A COLD FRONT WILL PASS THU
NIGHT/FRI MORNING...RESULTING IN A WIND SHIFT TO THE N AROUND 20 KT
FRI NIGHT INTO SAT. LIGHT WINDS WILL THEN DOMINATE ON SAT INTO SUN
AS TRAILING HI PRES MOVES BY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...TITUS
MARINE...KC
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1228 PM CDT WED SEP 16 2015
.DISCUSSION...
Issued at 341 AM CDT WED SEP 16 2015
Areas of showers and storms stretching from central Kansas through
northeast Nebraska early this morning will continue to translate
slowly eastward over the next several hours; however, at their
current speed and trajectory, precipitation will likely wane as the
LLJ weakens and the morning wears on before reaching the forecast
area. Scattered to broken stratus may linger even as precipitation
dissipates so have raised cloud cover for this morning across the
western half of the CWA, but clouds should then also dissipate as
boundary layer mixing builds during the late morning. Breezy
conditions are expected again this afternoon, which should mix down
high temperatures in the upper 80s nearly CWA-wide. Higher low-level
moisture will also advect in from the south southwest where dewpoints
are currently in upper 60s to lower 70s, and although mixing could
eliminate a few degrees from those readings by afternoon, the
afternoon will certainly feel a bit stickier than the last several
days as heat indices climb into the lower 90s. Both the RAP and HRRR
have been indicating a signal for convection across central MO for
this afternoon which could brush the southeastern corner of the CWA,
but feel that mixing has been overdone in the RAP and thus also the
HRRR this afternoon, possibly eliminating the cap erroneously. Have
raised PoPs to the upper-end of the silent range, but did not feel
slight chances were warranted given the biases of these model
solutions and a lack of continuity with other hires models.
Precipitation chances for tonight across central IA are starting to
look a bit lower, so have slightly lowered PoPs and shortened the
timeframe for possible convection in the northeastern quadrant of
the forecast area, where any IA storms that do develop would trek.
The thermal ridge strengthens directly over southern IA into the
northern CWA during the morning hours, likely ending any ongoing
precipitation shortly after sunrise.
This warm air aloft will be the primary complication for storm
chances on Thursday as convergence strengthens ahead of the well-
advertised cold front that will push through the forecast area late
Thursday through Friday. Shallow warm sector convection continues to
look probable Thursday afternoon with low-level moisture abound and
plenty of surface-based lift, but the potential for deep convective
initiation will be limited by capping even directly along the front
for much of the afternoon, and updrafts may have to wait until cooler
temperatures start to filter in aloft along an approaching shortwave
trough late Thursday evening. Several rounds of storms continue to
look likely along and immediately ahead of the slow-moving front
Thursday night through Friday, although the slightly delayed frontal
passage may allow for a bit of a break between rounds during the
daytime hours Friday. A few strong to marginally severe storms are
possible Thursday evening into the early afternoon due to high
instability supporting a few robust updrafts (and thus potentially
robust updraft collapses); and again Friday afternoon into the
early evening as the front clears through the region. Although cloud
cover throughout the day Friday may limit the strength of any
convection that redevelops along the front, increasing deep layer
shear will help any robust storms organize, possibly into a few
linear segments. Flooding also remains a concern with multiple rounds
of 2015-esque highly efficient rain, due to PWATs approaching
160-180% of normal.
The front will shift southeast and out of the region by late Friday
evening, leaving behind much quieter conditions and fall-like
temperatures for the weekend. Surface high pressure is faster to
build in, diminishing the longevity of strong cold air advection
during the daytime hours on Saturday; and height falls are not as
extreme behind this system when compared to the last, but highs in
the lower to mid 70s still look probable both Saturday and Sunday
before gradual warming begins once again. Due to uncertainties in the
long-term forecast, have opted to remove all slight chance PoPs for
next week until the litany of shortwave troughs in zonal to gradual
northwest flow become a bit more focused.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon)
Issued at 1221 PM CDT WED SEP 16 2015
For the afternoon, VFR conditions will continue with gusty winds out
of the south. Wind gusts may taper off periodically at sunset, but
will resume once the low-level jet initiates. Cloud cover will
increase ahead of an approaching cold front. Could see some isolated
convection early Thursday morning in the warm sector of the surface
low to the north, with additional chances of development in the
afternoon. The main threat will arrive ahead and along the cold
front late Thursday evening.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Laflin
AVIATION...Welsh
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
705 AM CDT WED SEP 16 2015
.DISCUSSION...
Issued at 341 AM CDT WED SEP 16 2015
Areas of showers and storms stretching from central Kansas through
northeast Nebraska early this morning will continue to translate
slowly eastward over the next several hours; however, at their
current speed and trajectory, precipitation will likely wane as the
LLJ weakens and the morning wears on before reaching the forecast
area. Scattered to broken stratus may linger even as precipitation
dissipates so have raised cloud cover for this morning across the
western half of the CWA, but clouds should then also dissipate as
boundary layer mixing builds during the late morning. Breezy
conditions are expected again this afternoon, which should mix down
high temperatures in the upper 80s nearly CWA-wide. Higher low-level
moisture will also advect in from the south southwest where dewpoints
are currently in upper 60s to lower 70s, and although mixing could
eliminate a few degrees from those readings by afternoon, the
afternoon will certainly feel a bit stickier than the last several
days as heat indices climb into the lower 90s. Both the RAP and HRRR
have been indicating a signal for convection across central MO for
this afternoon which could brush the southeastern corner of the CWA,
but feel that mixing has been overdone in the RAP and thus also the
HRRR this afternoon, possibly eliminating the cap erroneously. Have
raised PoPs to the upper-end of the silent range, but did not feel
slight chances were warranted given the biases of these model
solutions and a lack of continuity with other hires models.
Precipitation chances for tonight across central IA are starting to
look a bit lower, so have slightly lowered PoPs and shortened the
timeframe for possible convection in the northeastern quadrant of
the forecast area, where any IA storms that do develop would trek.
The thermal ridge strengthens directly over southern IA into the
northern CWA during the morning hours, likely ending any ongoing
precipitation shortly after sunrise.
This warm air aloft will be the primary complication for storm
chances on Thursday as convergence strengthens ahead of the well-
advertised cold front that will push through the forecast area late
Thursday through Friday. Shallow warm sector convection continues to
look probable Thursday afternoon with low-level moisture abound and
plenty of surface-based lift, but the potential for deep convective
initiation will be limited by capping even directly along the front
for much of the afternoon, and updrafts may have to wait until cooler
temperatures start to filter in aloft along an approaching shortwave
trough late Thursday evening. Several rounds of storms continue to
look likely along and immediately ahead of the slow-moving front
Thursday night through Friday, although the slightly delayed frontal
passage may allow for a bit of a break between rounds during the
daytime hours Friday. A few strong to marginally severe storms are
possible Thursday evening into the early afternoon due to high
instability supporting a few robust updrafts (and thus potentially
robust updraft collapses); and again Friday afternoon into the
early evening as the front clears through the region. Although cloud
cover throughout the day Friday may limit the strength of any
convection that redevelops along the front, increasing deep layer
shear will help any robust storms organize, possibly into a few
linear segments. Flooding also remains a concern with multiple rounds
of 2015-esque highly efficient rain, due to PWATs approaching
160-180% of normal.
The front will shift southeast and out of the region by late Friday
evening, leaving behind much quieter conditions and fall-like
temperatures for the weekend. Surface high pressure is faster to
build in, diminishing the longevity of strong cold air advection
during the daytime hours on Saturday; and height falls are not as
extreme behind this system when compared to the last, but highs in
the lower to mid 70s still look probable both Saturday and Sunday
before gradual warming begins once again. Due to uncertainties in the
long-term forecast, have opted to remove all slight chance PoPs for
next week until the litany of shortwave troughs in zonal to gradual
northwest flow become a bit more focused.
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday Morning)
Issued at 704 AM CDT WED SEP 16 2015
VFR conditions are expected to persist through the forecast period.
Scattered to broken stratus may arrive within a few hours from the
west even as showers dissipate, but should remain above 3 kft. This
cloud deck will scatter out gradually during the late morning hours,
then some isolated to scattered cumulus may develop during the
afternoon, but will be high based. Winds will continue to increase
over the next few hours, gusting to 25 kts or greater during the
daylight hours.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Laflin
AVIATION...Laflin
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
341 AM CDT WED SEP 16 2015
.DISCUSSION...
Issued at 341 AM CDT WED SEP 16 2015
Areas of showers and storms stretching from central Kansas through
northeast Nebraska early this morning will continue to translate
slowly eastward over the next several hours; however, at their
current speed and trajectory, precipitation will likely wane as the
LLJ weakens and the morning wears on before reaching the forecast
area. Scattered to broken stratus may linger even as precipitation
dissipates so have raised cloud cover for this morning across the
western half of the CWA, but clouds should then also dissipate as
boundary layer mixing builds during the late morning. Breezy
conditions are expected again this afternoon, which should mix down
high temperatures in the upper 80s nearly CWA-wide. Higher low-level
moisture will also advect in from the south southwest where dewpoints
are currently in upper 60s to lower 70s, and although mixing could
eliminate a few degrees from those readings by afternoon, the
afternoon will certainly feel a bit stickier than the last several
days as heat indices climb into the lower 90s. Both the RAP and HRRR
have been indicating a signal for convection across central MO for
this afternoon which could brush the southeastern corner of the CWA,
but feel that mixing has been overdone in the RAP and thus also the
HRRR this afternoon, possibly eliminating the cap erroneously. Have
raised PoPs to the upper-end of the silent range, but did not feel
slight chances were warranted given the biases of these model
solutions and a lack of continuity with other hires models.
Precipitation chances for tonight across central IA are starting to
look a bit lower, so have slightly lowered PoPs and shortened the
timeframe for possible convection in the northeastern quadrant of
the forecast area, where any IA storms that do develop would trek.
The thermal ridge strengthens directly over southern IA into the
northern CWA during the morning hours, likely ending any ongoing
precipitation shortly after sunrise.
This warm air aloft will be the primary complication for storm
chances on Thursday as convergence strengthens ahead of the well-
advertised cold front that will push through the forecast area late
Thursday through Friday. Shallow warm sector convection continues to
look probable Thursday afternoon with low-level moisture abound and
plenty of surface-based lift, but the potential for deep convective
initiation will be limited by capping even directly along the front
for much of the afternoon, and updrafts may have to wait until cooler
temperatures start to filter in aloft along an approaching shortwave
trough late Thursday evening. Several rounds of storms continue to
look likely along and immediately ahead of the slow-moving front
Thursday night through Friday, although the slightly delayed frontal
passage may allow for a bit of a break between rounds during the
daytime hours Friday. A few strong to marginally severe storms are
possible Thursday evening into the early afternoon due to high
instability supporting a few robust updrafts (and thus potentially
robust updraft collapses); and again Friday afternoon into the
early evening as the front clears through the region. Although cloud
cover throughout the day Friday may limit the strength of any
convection that redevelops along the front, increasing deep layer
shear will help any robust storms organize, possibly into a few
linear segments. Flooding also remains a concern with multiple rounds
of 2015-esque highly efficient rain, due to PWATs approaching
160-180% of normal.
The front will shift southeast and out of the region by late Friday
evening, leaving behind much quieter conditions and fall-like
temperatures for the weekend. Surface high pressure is faster to
build in, diminishing the longevity of strong cold air advection
during the daytime hours on Saturday; and height falls are not as
extreme behind this system when compared to the last, but highs in
the lower to mid 70s still look probable both Saturday and Sunday
before gradual warming begins once again. Due to uncertainties in the
long-term forecast, have opted to remove all slight chance PoPs for
next week until the litany of shortwave troughs in zonal to gradual
northwest flow become a bit more focused.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday Night)
Issued at 1152 PM CDT TUE SEP 15 2015
VFR conditions are expected to persist through the forecast period.
Scattered to broken stratus may build in shortly after sunset, but
ceilings are expected to remain above 3 kft. This cloud deck will
scatter out by mid- to late-morning, to be replaced by high-based,
isolated cumulus during the afternoon. Winds will be breezy once
again, reaching sustained speeds of 15 to 18 kts and gusts greater
than 25 kts during the daylight hours.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Laflin
AVIATION...Laflin
AREA FORECAST DISCUSSION
NWS ELKO NV
221 PM PDT WED SEP 16 2015
.SYNOPSIS...UNSEASONABLY COOL AFTERNOONS ARE EXPECTED BOTH
THURSDAY AND FRIDAY. A FINAL DISTURBANCE WILL SPREAD RAIN SHOWERS
ACROSS FAR NORTHERN NEVADA THURSDAY...WITH STRONG GUSTY WEST WINDS
ACROSS ELKO COUNTY. FRIDAY WILL FEATURE A COLD START AND A
BEAUTIFUL AFTERNOON WITH LIGHT WINDS. DRY AND WARMER WEATHER
RETURNS THIS WEEKEND.
&&
.SHORT TERM...TONIGHT THROUGH FRIDAY.
NEVADA SANDWICHED BETWEEN SHORTWAVES AGAIN THIS AFTERNOON, WITH
MUCH DRIER AIR ALLOWING ONLY SCATTERED CUMULUS ACROSS NORTHERN
NEVADA. LAST NIGHT`S STRONG SHORTWAVE IS NOW NEAR YELLOWSTONE
NATIONAL PARK, WITH SUBSIDENCE AND DRY AIR BEHIND IT KEEPING ANY
CONVECTION VERY LIMITED. WILL KEEP A MENTION OF CONVECTION ACROSS
MAINLY WHITE PINE COUNTY INTO THIS EVENING, WITH RADAR SHOWING
WEAK ECHOES TRYING TO ORGANIZE ALONG THE TRAILING FRONTAL
BOUNDARY. 18Z NAM AND ESPECIALLY HRRR SOLUTIONS SHOWING ACTIVE
CONVECTION ACROSS MAINLY WHITE PINE COUNTY THROUGH ABOUT 8 PM,
WITH CAPE TO 500 J/KG AND LIFTED INDEX OF -2. MEANWHILE, NEXT
SHORTWAVE ARRIVING IN NORTHERN CALIFORNIA THIS AFTERNOON WILL
SPREAD RAIN SHOWERS INTO HUMBOLDT COUNTY THIS EVENING. THIS
DISTURBANCE SCRAPES ACROSS FAR NORTHERN NEVADA TONIGHT, WITH
SHOWERS FOCUSED ALONG THE IDAHO/UTAH BORDERS WITH SNOW LEVELS
NEAR 8K FT.
THURSDAY...FINAL AND STRONG SHORTWAVE WILL ARRIVE IN SW OREGON
NEAR 5 AM, AND DIVE SE TO BE CENTERED OVER ELKO COUNTY AT 5 PM.
THIS SYSTEM WILL BE MOISTURE-STARVED IN NEVADA, WITH LITTLE IF ANY
RAINFALL SOUTH OF I-80. STRONG LIFT IN A COOL AIRMASS UNDER
PASSING VORT MAX WILL SHAKE OUT A GOOD ROUND OF SHOWERS ACROSS
NORTHERN ELKO COUNTY, WITH A FEW LIGHTNING STRIKES POSSIBLE.
STRONG GUSTY WEST WINDS WILL FOCUS ACROSS ELKO COUNTY THURSDAY
AFTERNOON BENEATH THIS VORT MAX, AVERAGING 20-30 MPH. SOME GUSTS
NEAR 40 MPH ON/NEAR HIGHER TERRAIN. UNSEASONABLY COOL AFTERNOON
HIGH TEMPERATURES, WITH MOST VALLEYS HOLDING IN THE 60S.
THURSDAY NIGHT/FRIDAY MORNING...FREEZING TEMPERATURES EXPECTED
ACROSS PORTIONS OF ELKO, EUREKA AND WHITE PINE COUNTIES. THE
GROWING SEASON HAS BEEN DECLARED OVER, AS SUCH NO FREEZE WARNINGS
WILL BE ISSUED.
FRIDAY...MUCH IMPROVED WEATHER, WITH MUCH LIGHTER WINDS, FEW
CLOUDS AND MILD TEMPERATURES. HIGHS IN THE UPPER 60S AND LOWER 70S
WITH WINDS MAINLY LESS THAN 5 MPH, SET YOUR TEE TIMES NOW! BAT
.LONG TERM...FRIDAY NIGHT THROUGH NEXT WEDNESDAY. AT THE START
OF THE PERIOD...THE 500MB LONG WAVE TROF RESPONSIBLE FOR THE
CURRENT UNSETTLED WEATHER WILL HAVE FILLED AND PUSHED EAST. ONE
FINAL PRONOUNCE 500MB TROF EXITS THE STATE SATURDAY MORNING WITH
LITTLE FANFARE. THIS GIVES WAY TO A GRADUAL INCREASE IN 500MB
HEIGHTS AS UPPER LEVEL FLOW BECOMES ZONAL WITH EVEN SOME WEAK
RIDGING OVER CENTRAL NV. UNDER THIS FLOW...A COUPLE OF EMBEDDED
SHORT WAVES WILL PASS THROUGH THE NORTHERN PARTS; HOWEVER NO
EFFECTS OTHER THAN SOME CIRRUS CLOUDS. BY MONDAY...A WEAK CLOSED-
OFF LOW WELL OFF THE COAST OF SOUTHERN CA COAST LIFTS NORTHEAST IN
RESPONSE TO A 500MB TROF/SURFACE FRONT (ORGINATING FROM THE LONG
WAVE TROF OVER THE GULF OF AK) APPROACHING THE PACIFIC NORTHWEST.
IT ALSO APPEARS THAT THIS LOW GRABS SOME TROPICAL
MOISTURE...PUSHING PW VALUES OVER 1 INCH BY TUESDAY AM IN PARTS
OF CENTRAL NV. THE MAIN ISSUE IS THE TRACK OF THIS FILLING
LOW...SPECIFICALLY HOW FAR NORTH IT MOVES. THE ECMWF PULLS THE
LOW AND MOISTURE FURTHER WEST...WHICH PROVIDES THE EASTERN HALF OF
THE CWA A GOOD SHOT OF PRECIP BY THE END OF THE PERIOD. THE GFS ON
THE OTHER HAND ONLY GIVES PORTIONS OF WHITE PINE AND EASTERN HALF
OF NORTHERN NYE MEASURABLE PRECIP. THE GFS ENSEMBLE AND GEM ALSO
INDICATED THE FEATURE BUT LEAN SLIGHTLY TOWARDS THE GFS PROGGED
TRACK. GIVEN THIS..IN ADDITION THAT THE CURRENT ECMWF TRACK IF
SLIGHTLY FURTHER SOUTH THAN THE 00Z RUN...AND THE TROF IS
POSITIVELY TILTED...KEPT THE HIGHEST POPS (20-40%) OVER THE
SOUTHEAST CORNER OF THE CWA...WITH 10-15% NORTHWARD TO THE ID/NV
BORDER.
AS FOR TEMPS...WITH HEIGHTS INCREASING...TEMPS WARM BACK INTO THE
80S...PEAKING ON SUNDAY BEFORE COOLING OFF ON TUESDAY AND
WEDNESDAY WITH CLOUD COVER AND LOWER HEIGHTS. OVERNIGHT LOWS WILL
SLOWLY WARM FROM THE 30S SATURDAY MORNING TO THE 40S AND 50S BY
TUESDAY AND WEDNESDAY. WINDS REMAIN LIGHT UNTIL TUESDAY AND
WEDNESDAY WHEN THEY INCREASE AHEAD THE 500MB TROF.
&&
.AVIATION...MAIN IMPACT FOR THE EARLY TIME FRAME IS THUNDERSTORMS
AT KELY WITH COLD FRONT OVERHEAD. MVFR CONDITIONS ARE LIKELY WITH
ANY THUNDERSTORM. ACTIVITY DECREASES THIS EVENING WITH A SHOWER OR
TWO POSSIBLE OVERNIGHT. IN ADDITION...NEED TO MONITOR FOR IFR CIGS
DURING THE 09-12Z TIME FRAME DUE TO RAINFALL RECEIVED TODAY. AT
KWMC AND KEKO...VFR CONDITIONS EXPECTED WITH POSSIBLE MVFR CIGS
DURING THE 09-12Z TIME FRAME DUE TO ANOTHER SYSTEM PASSING
OVERHEAD. A SHOWER OR TWO IS ALSO POSSIBLE. KTPH REMAINS VFR
DURING THE ENTIRE PERIOD. WINDS INCREASE AT ALL SITES AFTER 15Z
OUT OF THE WEST OR NORTHWEST.
&&
.FIRE WEATHER...STRONG SHORTWAVE WILL SPREAD SHOWERS ACROSS
NORTHERN NEVADA ON THURSDAY, WITH ACTIVITY FOCUSED ACROSS NORTHERN
FWZ 467, 468, 469 AND 470. STRONG GUSTY WEST WINDS ACROSS MAINLY
ELKO COUNTY THURSDAY AFTERNOON, WITH GUSTS OF 30-40 MPH.
UNSEASONABLY COOL TEMPERATURES WILL KEEP MIN RH ELEVATED, NEAR
30%. DRY WITH MUCH LIGHTER WINDS ON FRIDAY. BAT
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/85/85/99
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
933 PM PDT TUE SEP 15 2015
.SYNOPSIS...A PLUME OF TROPICAL MOISTURE HAS BROUGHT WIDESPREAD
LIGHT TO MODERATE RAIN TO THE REGION TODAY. THIS PLUME WILL SHIFT
EASTWARD OVERNIGHT WITH RAIN SHOWERS BECOMING CONFINED MAINLY TO
MOHAVE COUNTY TONIGHT. DRIER CONDITIONS ARE EXPECTED WEDNESDAY WITH
A FEW RESIDUAL SHOWERS AND STORMS POSSIBLE MAINLY IN MOHAVE COUNTY
AND EASTERN LINCOLN COUNTY. DRY CONDITIONS ARRIVE AREA WIDE THURSDAY
ONWARD WITH TEMPERATURES CREEPING BACK TOWARDS SEASONAL NORMALS.
&&
.UPDATE...MOST OF THE SHOWER ACTIVITY HAS WEAKENED ACROSS THE AREA.
A FEW LIGHT SHOWERS OR SPRINKLES WERE STILL DRIFTING ACROSS MOHAVE
COUNTY AND FAR SOUTHEAST SAN BERNARDINO COUNTY BUT THESE SHOULD GO
AWAY SOON. THE FORECAST WAS UPDATED TO TRIM BACK POPS FOR TONIGHT
AND DECREASE SKY COVER IN MANY AREAS BASED ON THE LATEST RADAR AND
SATELLITE TRENDS.
THE WIND ADVISORY WAS CANCELLED EARLIER THIS EVENING ACROSS WESTERN
CLARK AND SOUTHERN NYE COUNTIES AS WINDS HAD DROPPED BELOW THE 40
MPH GUST CRITERIA. THERE IS STILL SOME UNCERTAINTY AS TO HOW STRONG
WINDS WILL BE IN THE SPRING MOUNTAINS AND ESPECIALLY ON THE EASTERN
AND NORTHEASTERN SLOPES LATER TONIGHT. THE LATEST HRRR WAS MOT ALL
THAT IMPRESSIVE WITH WINDS THERE BUT THE ARW AND NMM MODELS STILL
SUPPORTED THIS.
THE BIG STORY TONIGHT WILL BE THE REFRESHING AIR THAT HAS ARRIVED.
TODAY REMINDED ME OF MY TIME IN FLORID WHEN YOU WALKED OUTSIDE
AFTER THE FIRST GOOD COLD FRONT OF THE FALL PUSHED THROUGH AFTER
SWELTERING ALL SUMMER (I AM SAYING THIS BECAUSE THIS COOL PUSH IS
NOT AS `DRY` FEELING AS OUT FIRST FALL COOL PUSH USUALLY IS AROUND
HERE). THIS WILL CERTAINLY BE A NICE BREAK FOR EVERYONE AS WELL AS
FOR THE AIR CONDITIONERS.
&&
.AVIATION...FOR MCCARRAN...CIGS WILL IMPROVE OVER THE NEXT FEW HOURS
AS DRIER AIR WORKS INTO THE REGION. GUSTY WINDS WILL SUBSIDE
OVERNIGHT...BUT REMAIN GUSTY OVER THE TERRAIN SURROUNDING THE
VALLEY. THIS WILL KEEP AREAS OF MECHANICAL TURBULENCE POSSIBLE ON
APPROACH TO THE TERMINAL. GUSTY WINDS WILL RETURN WEDNESDAY AT
AROUND 15 KTS AND GUSTS INTO THE MID-20`S. WINDS SHOULD RETURN TO
TYPICAL DIURNAL TRENDS BY THURSDAY.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...CIGS SHOULD IMPROVE THIS EVENING AS DRY AIR WORKS INTO
THE AREA. GUSTY RIDGETOP WINDS WILL CAUSE AREAS OF MECHANICAL
TURBULENCE ACROSS AND DOWNWIND OF HIGHER TERRAIN THROUGH WEDNESDAY.
GUSTY SOUTHWEST WINDS ARE EXPECTED AGAIN AT AREA TAF SITES
WEDNESDAY...WITH LIGHTER WINDS AREA WIDE BY THURSDAY.
&&
.PREVIOUS DISCUSSION...
ISSUED AT 255 PM PDT TUE SEP 2015
.SHORT TERM...THROUGH THURSDAY NIGHT.
MUCH DRIER CONDITIONS WILL FILTER IN WEDNESDAY WITH SHOWER AND
THUNDERSTORM CHANCES BECOMING CONFINED TO EASTERN MOHAVE COUNTY AND
LINCOLN COUNTY. SOUTHWESTERLY FLOW WILL SCOUR OUT ALL RESIDUAL
MOISTURE BY THURSDAY WITH DRY CONDITIONS EXPECTED AREA WIDE.
WARMER CONDITIONS ARE EXPECTED WEDNESDAY BUT IT WILL STILL BE
SEVERAL DEGREES BELOW NORMAL. SIMILAR HIGHS EXPECTED AGAIN ON
THURSDAY.
.LONG TERM...FRIDAY THROUGH TUESDAY. (FROM PREVIOUS DISCUSSION)
THE LONG TERM PERIOD BEGINS WITH WEAK TROUGHING ACROSS THE ENTIRE
FORECAST AREA BEHIND A VIGOROUS SHORTWAVE TROUGH THAT WILL BREAK
DOWN THE CURRENT TROUGH WEST/RIDGE EAST REGIME ACROSS THE LOWER 48.
DRY AIR BEHIND THE AFOREMENTIONED SHORTWAVE TROUGH WILL SPELL DRY
AND BENIGN WEATHER FOR THE ENTIRE PERIOD. THE 00Z OPERATIONAL MODELS
AND THEIR ASSOCIATED ENSEMBLES ARE IN GOOD AGREEMENT IN HIGH
PRESSURE OVER THE PACIFIC OCEAN AMPLIFYING THE OVERALL FLOW AND
KEEPING WEAK TROUGHING IN PLACE OVER THE FORECAST AREA THROUGH
SUNDAY. A WEAK SHORTWAVE WILL HELP TO KICK THE TROUGH EASTWARD
MONDAY...ALLOWING THE SUBTROPICAL RIDGE TO BUILD BACK INTO THE
DESERT SOUTHWEST. WHILE THE ONLY TRUE CHANGE IN THE STATUS QUO OF
WEATHER WILL BE WARMING TEMPERATURES ACROSS THE FORECAST AREA...IT
MAY SET THE STAGE FOR ANOTHER MOISTURE SURGE EARLY TO MID-NEXT
WEEK...AS MOISTURE FROM A TROPICAL WAVE CURRENTLY LOCATED NEAR 15N
108W MAY GET PULLED NORTHWARD INTO THE REGION. THIS WILL BE
DEPENDENT ON THE TIMING OF A POTENTIAL SHORTWAVE FROM THE GULF OF
ALASKA BRUSHING ACROSS THE NORTHERN GREAT BASIN TOWARD MID-WEEK.
THIS WILL BE SOMETHING TO WATCH IN THE COMING DAYS...AS THE
EVOLUTION AND TIMING OF EACH FEATURE WILL BE VITAL TO THE RESULTANT
WEATHER ACROSS THE REGION TOWARD MID-NEXT WEEK.
TEMPERATURE-WISE...EXPECT AFTERNOON HIGHS TO WARM FROM NEAR AVERAGE
ON FRIDAY TO SEVERAL DEGREES ABOVE AVERAGE BY THE BEGINNING OF NEXT
WEEK AS UPPER LEVEL RIDGING MAKES A RETURN TO THE AREA.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT EXPECTED
AT THIS TIME. HOWEVER...SPOTTERS ARE ENCOURAGED TO REPORT ANY
SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATE/AVIATION...STACHELSKI
SHORT TERM...OUTLER
LONG TERM...PULLIN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
833 PM PDT TUE SEP 15 2015
.SYNOPSIS...A PLUME OF TROPICAL MOISTURE HAS BROUGHT WIDESPREAD
LIGHT TO MODERATE RAIN TO THE REGION TODAY. THIS PLUME WILL SHIFT
EASTWARD OVERNIGHT WITH RAIN SHOWERS BECOMING CONFINED MAINLY TO
MOHAVE COUNTY TONIGHT. DRIER CONDITIONS ARE EXPECTED WEDNESDAY WITH
A FEW RESIDUAL SHOWERS AND STORMS POSSIBLE MAINLY IN MOHAVE COUNTY
AND EASTERN LINCOLN COUNTY. DRY CONDITIONS ARRIVE AREA WIDE THURSDAY
ONWARD WITH TEMPERATURES CREEPING BACK TOWARDS SEASONAL NORMALS.
&&
.UPDATE...MOST OF THE SHOWER ACTIVITY HAS WEAKENED ACROSS THE AREA.
A FEW LIGHT SHOWERS OR SPRINKLES WERE STILL DRIFTING ACROSS MOHAVE
COUNTY AND FAR SOUTHEAST SAN BERNARDINO COUNTY BUT THESE SHOULD GO
AWAY SOON. THE FORECAST WAS UPDATED TO TRIM BACK POPS FOR TONIGHT
AND DECREASE SKY COVER IN MANY AREAS BASED ON THE LATEST RADAR AND
SATELLITE TRENDS.
THE WIND ADVISORY WAS CANCELLED EARLIER THIS EVENING ACROSS WESTERN
CLARK AND SOUTHERN NYE COUNTIES AS WINDS HAD DROPPED BELOW THE 40
MPH GUST CRITERIA. THERE IS STILL SOME UNCERTAINTY AS TO HOW STRONG
WINDS WILL BE IN THE SPRING MOUNTAINS AND ESPECIALLY ON THE EASTERN
AND NORTHEASTERN SLOPES LATER TONIGHT. THE LATEST HRRR WAS MOT ALL
THAT IMPRESSIVE WITH WINDS THERE BUT THE ARW AND NMM MODELS STILL
SUPPORTED THIS.
THE BIG STORY TONIGHT WILL BE THE REFRESHING AIR THAT HAS ARRIVED.
TODAY REMINDED ME OF MY TIME IN FLORID WHEN YOU WALKED OUTSIDE
AFTER THE FIRST GOOD COLD FRONT OF THE FALL PUSHED THROUGH AFTER
SWELTERING ALL SUMMER (I AM SAYING THIS BECAUSE THIS COOL PUSH IS
NOT AS `DRY` FEELING AS OUT FIRST FALL COOL PUSH USUALLY IS AROUND
HERE). THIS WILL CERTAINLY BE A NICE BREAK FOR EVERYONE AS WELL AS
FOR THE AIR CONDITIONERS.
&&
.AVIATION...FOR MCCARRAN...CIGS WILL IMPROVE OVER THE NEXT FEW HOURS
AS DRIER AIR WORKS INTO THE REGION. GUSTY WINDS WILL SUBSIDE
OVERNIGHT...BUT REMAIN GUSTY OVER THE TERRAIN SURROUNDING THE
VALLEY. THIS WILL KEEP AREAS OF MECHANICAL TURBULENCE POSSIBLE ON
APPROACH TO THE TERMINAL. GUSTY WINDS WILL RETURN WEDNESDAY AT
AROUND 15 KTS AND GUSTS INTO THE MID-20`S. WINDS SHOULD RETURN TO
TYPICAL DIURNAL TRENDS BY THURSDAY.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...CIGS SHOULD IMPROVE THIS EVENING AS DRY AIR WORKS INTO
THE AREA. GUSTY RIDGETOP WINDS WILL CAUSE AREAS OF MECHANICAL
TURBULENCE ACROSS AND DOWNWIND OF HIGHER TERRAIN THROUGH WEDNESDAY.
GUSTY SOUTHWEST WINDS ARE EXPECTED AGAIN AT AREA TAF SITES
WEDNESDAY...WITH LIGHTER WINDS AREA WIDE BY THURSDAY.
&&
.PREVIOUS DISCUSSION...
ISSUED AT 255 PM PDT TUE SEP 2015
.SHORT TERM...THROUGH THURSDAY NIGHT.
MUCH DRIER CONDITIONS WILL FILTER IN WEDNESDAY WITH SHOWER AND
THUNDERSTORM CHANCES BECOMING CONFINED TO EASTERN MOHAVE COUNTY AND
LINCOLN COUNTY. SOUTHWESTERLY FLOW WILL SCOUR OUT ALL RESIDUAL
MOISTURE BY THURSDAY WITH DRY CONDITIONS EXPECTED AREA WIDE.
WARMER CONDITIONS ARE EXPECTED WEDNESDAY BUT IT WILL STILL BE
SEVERAL DEGREES BELOW NORMAL. SIMILAR HIGHS EXPECTED AGAIN ON
THURSDAY.
.LONG TERM...FRIDAY THROUGH TUESDAY. (FROM PREVIOUS DISCUSSION)
THE LONG TERM PERIOD BEGINS WITH WEAK TROUGHING ACROSS THE ENTIRE
FORECAST AREA BEHIND A VIGOROUS SHORTWAVE TROUGH THAT WILL BREAK
DOWN THE CURRENT TROUGH WEST/RIDGE EAST REGIME ACROSS THE LOWER 48.
DRY AIR BEHIND THE AFOREMENTIONED SHORTWAVE TROUGH WILL SPELL DRY
AND BENIGN WEATHER FOR THE ENTIRE PERIOD. THE 00Z OPERATIONAL MODELS
AND THEIR ASSOCIATED ENSEMBLES ARE IN GOOD AGREEMENT IN HIGH
PRESSURE OVER THE PACIFIC OCEAN AMPLIFYING THE OVERALL FLOW AND
KEEPING WEAK TROUGHING IN PLACE OVER THE FORECAST AREA THROUGH
SUNDAY. A WEAK SHORTWAVE WILL HELP TO KICK THE TROUGH EASTWARD
MONDAY...ALLOWING THE SUBTROPICAL RIDGE TO BUILD BACK INTO THE
DESERT SOUTHWEST. WHILE THE ONLY TRUE CHANGE IN THE STATUS QUO OF
WEATHER WILL BE WARMING TEMPERATURES ACROSS THE FORECAST AREA...IT
MAY SET THE STAGE FOR ANOTHER MOISTURE SURGE EARLY TO MID-NEXT
WEEK...AS MOISTURE FROM A TROPICAL WAVE CURRENTLY LOCATED NEAR 15N
108W MAY GET PULLED NORTHWARD INTO THE REGION. THIS WILL BE
DEPENDENT ON THE TIMING OF A POTENTIAL SHORTWAVE FROM THE GULF OF
ALASKA BRUSHING ACROSS THE NORTHERN GREAT BASIN TOWARD MID-WEEK.
THIS WILL BE SOMETHING TO WATCH IN THE COMING DAYS...AS THE
EVOLUTION AND TIMING OF EACH FEATURE WILL BE VITAL TO THE RESULTANT
WEATHER ACROSS THE REGION TOWARD MID-NEXT WEEK.
TEMPERATURE-WISE...EXPECT AFTERNOON HIGHS TO WARM FROM NEAR AVERAGE
ON FRIDAY TO SEVERAL DEGREES ABOVE AVERAGE BY THE BEGINNING OF NEXT
WEEK AS UPPER LEVEL RIDGING MAKES A RETURN TO THE AREA.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT EXPECTED
AT THIS TIME. HOWEVER...SPOTTERS ARE ENCOURAGED TO REPORT ANY
SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATE/AVIATION...STACHELSKI
SHORT TERM...OUTLER
LONG TERM...PULLIN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
821 PM EDT THU SEP 17 2015
.SYNOPSIS...
HIGH PRESSURE TO OUR NORTH IS LOSING ITS INFLUENCE WHILE A SURFACE
TROUGH DEVELOPING ALONG THE COAST OVER THE WEEKEND. A COLD FRONT
WILL MOVE IN FROM THE NORTH SUNDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 700 PM THURSDAY...THE CENTER OF SFC HIGH PRESSURE IS NOW
LOCATED JUST OFFSHORE FROM THE VA CAPES. ALOFT...A BROAD AND WEAK
TROF WILL AFFECT THE FA WITH ITS AXIS ORIENTED FROM CENTRAL FL
NORTHEASTWARD TO JUST EAST AND OFFSHORE FROM CAPE HATTERAS. ITS
PROGGED TO SLIGHTLY DRIFT EASTWARD OVERNIGHT VIA LATEST RAP MODEL.
THE INVERTED SFC TROF WILL BECOME MORE PRONOUNCED ACROSS THE ATL
WATERS...ORIENTED NE-SW REMAINING JUST OFFSHORE FROM THE CAROLINA
COASTS. VIA LATEST VARIOUS MODEL TIME HEIGHT DISPLAYS ACROSS THE
FA...SPECIFICALLY MOISTURE PROFILES...THE ATM WILL REMAIN
RELATIVELY MOISTENED THRU THE ATM COLUMN ALONG THE IMMEDIATE COAST
AND ADJACENT ATL WATERS. THE ATM COLUMN WILL BECOME NOTICEABLY
DRIER THE FURTHER INLAND 1 PROGRESSES FROM THE COAST WITH THE I-95
CORRIDOR AND WESTWARD SEEING MAINLY A CI/CS DECK. WEAK
PERTURBATION IN THE LOW TO MID-LEVELS AND THE OFFSHORE INVERTED
SFC TROF WILL PROVIDE NECESSARY DYNAMICS FOR LOW TOPPED CONVECTION
TO DEVELOP OVER THE ATL WATERS. THE LOW TO MID LEVEL EASTERLY FLOW
AS VIEWED BY THE LATEST KLTX VWP...EXPECT THIS PCPN TO
SPORADICALLY MOVE ONSHORE. THE PCPN WILL DISSIPATE THE FURTHER
INLAND IT PROGRESSES DUE TO THE PRONOUNCED DRIER AIR. HAVE ONLY
RE-ALIGNED/TWEAKED THE OVERNIGHT CHANCE POPS...BASICALLY LIMITING
AND DIMINISHING THE POPS THE FURTHER INLAND THE PCPN ACTIVITY
PUSHES INLAND. LOW TEMPS TO RANGE FROM THE MID 60S INLAND...TO
AROUND 70 ALONG THE IMMEDIATE COAST. WITH ONSHORE FLOW PERSISTING
AND LOCAL SSTS AROUND 80 DEGREES...THE IMMEDIATE BEACHES MAY SEE
LOWS IN THE 70-75 RANGE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY... A TROUGH OF LOW PRESSURE WILL EXTEND UP THE
COAST ON FRIDAY NORTHEAST FROM AN ORGANIZING AREA OF LOW PRESSURE
OVER FL PENINSULA. JUST HAS BEEN THE CASE TODAY THIS WILL CHANNEL
MOISTURE UP THE WITH SOME LIGHT RAIN POSSIBLE A FEW MILES INLAND
WHEREAS RADAR RETURNS WILL BE MUCH MORE COMMON OVER THE WATER. TEMPS
AGAIN HELD A BIT BELOW CLIMO SAVE FOR FAR INLAND ZONES WHERE SOME
SUNSHINE SHOULD BREAK OUT AT TIMES. ONE FACTOR THAT COULD CALL FOR
SLIGHTLY LOWERED RAIN CHANCES IS THE SHARPENING OF THE 850MB TROUGH
EAST OF ITS CURRENT LOCATION. LOOKING AHEAD TO SATURDAY THE SURFACE
LOW BEGINS TO STRENGTHEN AND HEAD NORTHEASTWARD. THIS PULLS THE
805MB CONVERGENCE BACK CLOSER TO THE COASTLINE AND RAIN CHANCES MAY
INCREASE SOMEWHAT WHILE MAINTAINING A VERY STRONG EAST-WEST
GRADIENT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...LOOKING AT WELL ABOVE NORMAL TEMPERATURES FOR
SUNDAY WITH A BROAD AREA OF LOW PRESSURE OFF THE COAST AND A COLD
FRONT DESCENDING FROM THE NW. A BLEND OF GUIDANCE GIVES US HIGHS IN
THE UPPER 80S MOST PLACES AND MID 80S ALONG THE COAST. SUBSIDENCE ON
THE BACKSIDE OF THE OFFSHORE LOW AND AMPLE INSOLATION WILL AID IN
PRODUCING THE UNSEASONABLE WARMTH. THE SUBSIDENCE AND A DRY-ISH
COLUMN WILL ALSO ACT TO SUPPRESS CONVECTION ON SUNDAY. THE COLD
FRONT MOVES OFFSHORE SUNDAY NIGHT...ALLOWING TEMPERATURES TO RETURN
TOWARDS MORE SEASONAL LEVELS BY TUESDAY. FOR THE REMAINDER OF THE
LONG TERM WE WILL HAVE A GENERAL RIDGING PATTERN EXTENDING DOWN THE
EASTERN SEABOARD WITH BROAD AREA OF LOW PRESSURE IN THE FORM OF THE
STALLED AND DECAYING COLD FRONT OR POSSIBLY A SERIES OF WEAK LOW
PRESSURE CENTERS OFFSHORE. THIS WILL KEEP IN A MILD NORTHEASTERLY
FLOW THROUGH THE PERIOD.
A COUPLE OF FEATURES OF INTEREST MAY BE PRESENT DURING THE LONG
TERM. THE FIRST CONCERNS POSSIBLE TROPICAL DEVELOPMENT OFF THE
SOUTHEAST US COAST LATE THIS WEEKEND OR EARLY NEXT WEEK AS A
DISTURBANCE OVER THE EASTERN GULF OF MEXICO MOVES NE INTO THE
ATLANTIC. IT IS WAY TO EARLY TO SAY WHAT IMPACTS...IF ANY...IT WILL
HAVE ON THE LOCAL AREA...BUT PRESENT GUIDANCE WOULD KEEP ANY SUCH
DEVELOPMENT WELL OFFSHORE. THE SECOND FEATURE INCLUDES AN
UNSEASONABLY STRONG AND DEEP UPPER POOL OF COLD AIR THAT WILL
DESCEND UPON THE REGION WEDNESDAY AND THURSDAY AS A SHARP UPPER
TROUGH BECOMES CUT OFF FROM THE MAIN FLOW. THIS FEATURES ATTENDANT
STEEPENING OF LAPSE RATES AND LOWERED FREEZING LEVELS COULD ENHANCE
CONVECTION IN THE MIDDLE TO LATTER PORTION OF THE WEEK...WITH THE
POSSIBILITY WE COULD SEE SOME SMALL HAIL OR GRAUPEL SHOWERS.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 00Z...LOW PRESSURE OFF THE COAST OF GEORGIA WILL REMAIN
FAIRLY STATIONARY THROUGH THE FORECAST PERIOD. PLENTY OF CLOUDS
ROTATING AROUND THE NORTHERN PORTION OF THE LOW...WITH ISOLATED
SHOWERS AT THIS TIME MAINLY OFFSHORE. THINK MOST OF THE CONVECTION
WILL STAY OFFSHORE OVERNIGHT...WITH A STRAY SHOWER POSSIBLE AT THE
COASTAL TERMINALS. CEILINGS ARE A BIT OF A PUZZLE AS THE MODELS
ARE NOT IN GOOD AGREEMENT. LOOK FOR CEILINGS TO BOUNCE FROM MVFR
TO NEAR VFR OVERNIGHT...WITH MVFR VISIBILITIES INLAND. FRIDAY MORE
OF THE SAME WITH A VFR STRATO-CU CEILING AND ISOLATED SHOWERS
NEAR THE COAST. MAINLY EAST NORTHEAST FLOW THROUGH THE PERIOD.
EXTENDED OUTLOOK...COASTAL SHOWERS ARE POSSIBLE THROUGH SATURDAY
OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 730 PM THURSDAY...RAISED A SCEC FOR THE ILM SC WATERS FOR
THE REMAINDER OF TONIGHT INTO SATURDAY.
OVERALL...LOOK FOR THE INVERTED SFC TROF TO BECOME MORE PRONOUNCED
LYING JUST OFFSHORE FROM THE AREA WATERS AND RELATIVELY PARALLEL
TO THE CAROLINA COASTLINES FROM CAPE HATTERAS SOUTHWARD. THE SFC
PG WILL TIGHTEN-SOME ESPECIALLY SOUTH OF CAPE FEAR VIA LATEST RAP
MODEL RUNS. LOOK FOR WIND SPEEDS IN THE 10 TO 20 KT RANGE...WITH
THE HIER END OF THIS RANGE MAINLY ACROSS THE ILM SC WATERS. WILL
KEEP THE INVERTED SFC TROF JUST EAST OF THE AREA WATERS...
RESULTING IN NE TO E WIND DIRECTIONS PERSISTING ACROSS THE LOCAL
WATERS. WILL SEE MORE OF A NE DIRECTION AS THE SFC TROF ITSELF
AMPLIFIES VIA ITS PRESSURE PATTERN ORIENTATION. SIGNIFICANT SEAS
TO START OUT IN THE 2 TO 4 FT RANGE FOR ALL WATERS...BUT LIKELY
BUILD TO THE 3 TO 5 FT RANGE ACROSS THE ILM SC WATERS. WIND DRIVEN
WAVES IN THE 3 TO 5SECOND PERIOD RANGE WILL COMBINE WITH THE
PSEUDO EASTERLY SWELL WITH PERIODS RANGING BETWEEN 6 AND 8
SECONDS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY... LOW PRESSURE TROUGHINESS EXTENDING UP THE
COAST FRIDAY FROM A DEVELOPING LOW OVER FLORIDA. THIS WILL PINCH THE
GRADIENT OVER MAINLY SRN ZONES THROUGH THE DAY AND NRN ZONES AT
NIGHT. DURING THOSE AFOREMENTIONED TIME RANGES AND PLACES THERE
COULD BE A VERY MARGINAL AND VERY SHORT-LIVED PERIOD OF 6 FT SEAS
ALONG THE VERY OUTER REACHES OF THE FORECAST ZONES. THIS IS
ESPECIALLY TRUE WITH THE MORE AGGRESSIVE WNA GUIDANCE AND NOT SO MUCH
THE CASE AT ALL WITH THE LOCAL SWAN OUTPUT. FELT BEST COURSE AT THIS
POINT WAS TO BLEND THE TWO, BUT NOT RAISE ADVISORY DUE TO LOW
CONFIDENCE LEVEL. THE EXPANDING AND POSSIBLY STRENGTHENING LOW MOVES
NE AWAY FROM FLORIDA ON SATURDAY BUT ITS PROXIMITY TO THE COASTLINE
ACTUALLY WEAKENS THE GRADIENT SOME AND THE NEED FOR AN ADVISORY
APPEARS MINIMAL. SCEC OVER A FEW ZONES TOUGH TO RULE OUT THOUGH.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 PM THURSDAY...NORTH THROUGH NORTHEAST WINDS IN THE GENERAL
RANGE OF 10 TO 15 KTS WILL PREVAIL THROUGH THE LONG TERM WITH HIGH
PRESSURE OVER THE EASTERN SEABOARD AND AN AREA OF LOW PRESSURE EAST
OF THE WATERS. SEAS WILL RANGE FROM 2 TO 4 FT THROUGH THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...REK
AVIATION...DL
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
943 PM EDT THU SEP 17 2015
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE ALONG THE EAST COAST WILL WEAKEN AND
MOVE EAST THIS WEEKEND. THIS WILL ALLOW A COLD FRONT TO MOVE
THROUGH SATURDAY AFTERNOON AND EVENING. HIGH PRESSURE WILL BUILD
EAST ACROSS THE GREAT LAKES AND LOWER OHIO VALLEY SATURDAY NIGHT AND
LINGER THROUGH EARLY MONDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
HAVE TRIED TO FINE TUNE THE FORECAST. CLOUDS FROM THE CONVECTION
OVER NRN IL AND SRN WI ARE JUST ABOUT TO NW OHIO. THESE CLOUDS
WILL OVERSPREAD THE WEST HALF OF THE AREA OVERNIGHT SO HAVE
BUMPED UP TEMPS IN NW OH A FEW DEGREES. LATEST HRRR CONTINUES TO
SHOW SOME OF THE PRECIP MAKING IT TO THE LOCAL AREA LATE TONIGHT
AND FRIDAY MORNING SO SEE NO NEED TO CHANGE PRECIP CHANCES.
ORIGINAL...MOSTLY CLEAR SKIES ACROSS THE AREA THIS AFTERNOON WILL
CONTINUE THROUGH THE EVENING AND INTO THE OVERNIGHT BEFORE CLOUDS
BEGIN TO INCREASE IN THE WEST. BY MORNING THE GFS AND NAM AGREE ON
A SIGNIFICANT AMOUNT OF MOISTURE GETTING INTO THE WESTERN
COUNTIES. NO PLANNING ON ANY CONVECTION AT 12Z BUT WILL HAVE A
SLIGHT CHANCE POP IN THE GRIDS BY MORNING. CLOUDS SHOULD MOVE IN
AFTER MIDNIGHT. EAST OF A MNN-LPR LINE WILL KEEP SKIES PC. LOWS
SIMILAR TO LAST NIGHT.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
THE SHORT TERM BEGINS WITH DEEP MOISTURE MOVING INTO THE WESTERN
COUNTIES WHILE TO THE EAST HIGH PRESSURE AND DRY AIR WILL STILL BE
HOLDING ON. MODELS BRING THE MOISTURE EAST ACROSS THE AREA DURING
THE DAY FINALLY REACHING NWRN PA BY 21-00Z TIME FRAME. AM
EXPECTING SHOWERS TO MOVE EAST ACROSS THE AREA DURING THE DAY
ALTHOUGH AS THEY MOVES EAST EXPECTING SHOWERS TO THIN AS THEY RUN
INTO DRIER AIR. STILL...WILL HAVE CHANCE POPS FOR THE DAY FOR MOST
LOCATIONS. FRIDAY NIGHT A WAVE DEVELOPS ON THE FRONT AND MOVES
NORTHEAST INTO THE CENTRAL LAKES ON SATURDAY. WEAK WARM ADVECTION
DEVELOPS FRIDAY NIGHT ACROSS THE AREA AHEAD OF THE DEVELOPING LOW
AND WILL LIKELY BE THE FOCUS FOR A CONTINUED THREAT OF SHOWERS.
MODELS IN DECENT AGREEMENT WITH THE COLD FRONT TIMING SATURDAY
WITH PASSAGE BEGINNING IN THE WEST ABOUT NOON AND EXITING THE AREA
EAST ABOUT 6PM. WILL CONTINUE WITH LIKELY POPS ACROSS THE AREA.
DRY AIR AND HIGH PRESSURE BUILD IN QUICKLY IN ITS WAKE SATURDAY.
WILL HAVE LIKELY POPS TO START FAR EAST SATURDAY NIGHT BUT WILL
DRY OUT THE FORECAST FOR THE OVERNIGHT. TEMPS ABOVE NORMAL FRIDAY
DROPPING TO BELOW NORMAL BY SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
MODELS ARE SUGGESTING AN UPPER LEVEL LOW BECOMING CUT OFF ACROSS THE
SERN US. THIS TROUGH WILL BE ACCOMPANIED BY A SHARP INVERTED TROUGH
AT THE SURFACE WHICH WILL DEVELOP NEAR THE OH PA BOARDER. THE LATEST
GFS AND ECMWF RUNS CONTINUE TO PRINT OUT LIGHT QPF ACROSS WESTERN PA
INTO EASTERN OH. DESPITE SUFFICIENT FORCING...MOISTURE WILL BE
SOMEWHAT LIMITED WITH HIGH PRESSURE BULGING IN FROM THE NORTH. KEPT
THE SLIGHT CHANCE 20 POPS GOING FROM CLEVELAND EAST ON TUESDAY...BUT
WOULDNT BE SURPRISED IF LATER FORECASTS CONTINUE TO DIAL BACK POPS.
IN OTHER WORDS...MOST OF MON AND TUE WILL BE DRY WITH PERHAPS A
SHOWER OR TWO IN THE FAR EAST. TEMPERATURES WILL BE VERY CLOSE TO
NORMAL.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
THE AREA REMAINS BETWEEN HIGH PRESSURE LOCATED ALONG THE
EAST COAST AND A SLOWLY APPROACHING TROUGH DRAPED ACROSS THE UPPER
MIDWEST. MOISTURE ASSOCIATED WITH THE TROUGH WILL INCREASE ACROSS
NORTHWEST OHIO TOWARDS DAWN AND SHOWERS WILL LIKELY IMPACT
TOL...BECOMING MORE SCATTERED TOWARDS FDY. THERE IS A CHANCE OF
THUNDERSTORMS BUT WAS LOW ENOUGH TO LEAVE OUT OF THE TERMINALS FOR
NOW. MOISTURE WILL CONTINUE TO SPREAD EAST DURING THE DAYTIME HOURS
ON FRIDAY BUT BETTER CHANCES FOR SHOWERS OR THUNDERSTORMS WILL
REMAIN NORTH OF THE TERMINALS. OTHERWISE LIGHT SOUTH TO SOUTHEAST
WINDS OVERNIGHT WILL SHIFT BACK TO SOUTHWEST NEAR 10 KNOTS AFTER 15Z
FRIDAY.
OUTLOOK...NON-VFR POSSIBLE WITH SHOWERS AND THUNDERSTORMS BEGINNING
FRIDAY NIGHT...AND INCREASING ALONG A COLD FRONT ON
SATURDAY/SATURDAY EVENING. NON-VFR CLOUDS MAY LINGER INTO SUNDAY
MORNING...ESPECIALLY NEAR LAKE ERIE.
&&
.MARINE...
HIGH PRESSURE IS GRADUALLY MOVING OFF TO THE EAST. A WEAK
FRONT/SURFACE TROUGH WILL CROSS THE WESTERN END OF THE LAKE FRIDAY
MORNING THEN WEAKEN. A SECONDARY COLD FRONT WILL CROSS THE LAKE
DURING THE DAYLIGHT HOURS ON SATURDAY. A SMALL CRAFT ADVISORY IS
LIKELY LATE SATURDAY INTO SUNDAY AS THE FLOW PICKS UP BEHIND THE
FRONT. BY MONDAY HIGH PRESSURE WILL BE NORTH OF THE LAKE WITH
ONSHORE FLOW.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK/KUBINA
SHORT TERM...TK
LONG TERM...MAYERS
AVIATION...KEC
MARINE...MAYERS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
751 PM EDT THU SEP 17 2015
.SYNOPSIS...
A COLD FRONT WILL APPROACH ON FRIDAY BEFORE PUSHING THROUGH THE
OHIO VALLEY ON SATURDAY...ALLOWING FOR SHOWERS AND PERHAPS A FEW
THUNDERSTORMS. HIGH PRESSURE AND COOLER TEMPERATURES WILL BUILD IN
BEHIND THE FRONT ON SUNDAY.
&&
.NEAR TERM /UNTIL 7 AM FRIDAY MORNING/...
UPSTREAM CONVECTION IS NOT SHOWING MUCH IN THE WAY OF BLOWOFF THAT
WAS EXPECTED TO PUSH INTO NW FCST AREA LATER THIS EVENING. HAVE
PARED BACK THE EXPECTED CLOUD COVER TO OCCUR MORE TOWARDS DAYBREAK
AND COINCIDE WITH THE PASSAGE OF H5 S/W THROUGH NRN OHIO. THIS IS
THE BRUNT OF THE FORECAST CHANGE THIS EVENING. ALSO PARED BACK
SOME IN THE CHANCES OF A SHOWER OCCURRING BEFORE DAYBREAK IN THE
NORTHWEST. CURRENT GUIDANCE STILL HAS THE S/W IN INDIANA AT 12Z
AND ALL BUT THE TINIEST SLIVER OF NW OHIO DRY THROUGH THIS TIME.
&&
.SHORT TERM /7 AM FRIDAY MORNING THROUGH SATURDAY/...
HAVE USED A BLEND OF THE GFS AND ECMWF FOR THE SHORT TERM
FORECAST.
COLD FRONT WILL MOVE A LITTLE FARTHER SOUTHEAST ON FRIDAY BUT
WILL REMAIN WELL TO OUR NORTHWEST. THERE COULD BE CONSIDERABLE
CLOUDS DURING THE MORNING HOURS RESULTING FROM PREVIOUS NIGHTS
CONVECTION TO OUR NORTHWEST. AGAIN...A FEW SHOWERS MAY BE SKIMMING
OUR NORTHWEST ZONES DURING THE MORNING. IT LOOKS LIKE ANY
SHOWER/THUNDERSTORM ACTIVITY WILL REMAIN CLOSER TO THE FRONT FOR
THE AFTERNOON HOURS. TEMPERATURES WILL BE CLOUD DEPENDENT BUT
SHOULD WARM INTO THE LOWER AND MID 80S ONCE AGAIN.
FOR FRIDAY NIGHT...POTENT S/WV WITHIN THE FLOW ALOFT WILL EJECT
NORTHEAST TO THE GREAT LAKES. A STRONG LLJ WILL TEAM UP WITH
FAVORABLE UPR DIV FROM THE RR QUAD OF AN UPR LVL JET TO PERTURB A
WAVE LOW PRESSURE ON THE FRONT. WIDESPREAD PCPN IS EXPECTED FROM
NRN IL...SRN WI...NRN IND...SRN MI AND THEN INTO NW OHIO. OUR AREA
WILL BE ON THE PERIPHERY OF THE BEST LOW LEVEL FORCING SO ONLY
HAVE CHANCE POPS IN THE FORECAST FOR THE NW TAPERING OFF TO A DRY
FORECAST MAINLY ALONG AND SOUTHEAST OF I-71. OVERNIGHT LOWS WILL
BE MAINLY IN THE 60S.
ON SATURDAY...AS WAVE OF LOW PRESSURE PASSES BY TO OUR NORTHEAST...
ATTENDANT COLD FRONT THEN WILL MOVE THROUGH OUR AREA. THE FRONT
WILL INTERACT WITH FAIRLY HIGH PWATS. HOWEVER...LIFT WILL BE
MAINLY FROM LOW LEVEL FRONTAL CONVERGENCE ALONG AND AHEAD OF THE
FRONT. WE SHOULD AT LEAST SEE LIKELY POPS FOR OUR WESTERN HALF OF
THE CWFA...BUT FRONTAL CONVERGENCE SEEMS TO WEAKEN AS IT MOVES
THROUGH THE REMAINDER OF THE AREA SATURDAY AFTERNOON AND
EVENING...SO HAVE CHANCE POPS ELSEWHERE. THERE SHOULD BE ENOUGH
INSTABILITY FOR EMBEDDED THUNDER.
BY SATURDAY NIGHT...THE COLD FRONT WILL EXIT TO OUR SOUTHEAST...
ALLOWING SURFACE HIGH PRESSURE TO BUILD IN FROM THE NORTHWEST.
DRIER AND COOLER WEATHER WILL FILTER INTO THE REGION. LOWS WILL
BOTTOM OUT IN THE UPPER 40S NORTH TO THE MID 50S ALONG AND SOUTH
OF THE OHIO RIVER.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
AT THE START OF THE EXTENDED FORECAST PERIOD...A COLD FRONT WILL BE
JUST SOUTHEAST OF THE ILN FORECAST AREA...WITH HIGH PRESSURE
BUILDING INTO THE SOUTHERN GREAT LAKES AND NORTHERN OHIO VALLEY.
THIS HIGH WILL BE FAIRLY DRY...PROVIDING A MOSTLY SUNNY DAY ON
SUNDAY...WITH HIGHS IN THE LOWER TO MID 70S.
THE FOCUS GOING INTO THE FIRST HALF OF THE WEEK WILL BE ON THE
FORMATION OF AN AREA OF UPPER LEVEL LOW PRESSURE...WHICH WILL
DEVELOP AS THE SURFACE HIGH TRANSLATES NORTHEAST. AT THE SAME
TIME...A SSW-TO-NNE ORIENTED SURFACE TROUGH WILL DEVELOP JUST WEST
OF THE APPALACHIAN MOUNTAINS...WITH MOISTURE AND PRECIPITATION
SPREADING ALONG THE MOUNTAINS AND INTO THE UPPER OHIO AND TENNESSEE
VALLEY REGIONS BY MONDAY NIGHT. THERE IS DECENT AGREEMENT BETWEEN
THE 12Z GFS/ECMWF THROUGH TUESDAY...AND BOTH MODELS SUGGEST THAT
MOST OF THE PRECIPITATION WILL REMAIN EAST OF THE ILN FORECAST AREA.
THUS...POPS HAVE BEEN SLIGHTLY LOWERED FROM THE PREVIOUS
FORECAST...WITH ONLY SLIGHT CHANCES OF SHOWERS EXPECTED ON MONDAY
AND TUESDAY (PERHAPS A LITTLE MORE LIKELY ON TUESDAY). WITH MODELS
INDICATING RELATIVELY STABLE CONDITIONS...THUNDER SEEMS UNLIKELY.
MODEL SPREAD INCREASES SIGNIFICANTLY BY WEDNESDAY...PRIMARILY WITH
REGARD TO THE LOCATION AND STRENGTH OF THE UPPER LOW. THE 12Z
OPERATIONAL RUNS LOOK VASTLY DIFFERENT TODAY THAN THEY DID
YESTERDAY. GFSE MEMBERS ARE SHOWING A POSITIONAL SPREAD OF AROUND
400 MILES WITH REGARDS TO THE CENTER OF THE UPPER LOW BY 12Z
WEDNESDAY MORNING...AND ARE SPREAD OUT ENOUGH BY WEDNESDAY EVENING
THAT THE ENSEMBLE MEAN IS SO DAMPENED AS TO MISS THE PRESENCE OF THE
CLOSED LOW ENTIRELY. THUS...THE FORECAST BEYOND TUESDAY IS OF VERY
LOW CONFIDENCE. A GRADUAL WARMING TREND THROUGH THE WEEK WILL BE
FORECAST...WITH TEMPERATURES RETURNING TO NEAR NORMAL BY THE MIDDLE
OF THE WEEK.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
LIGHT SOUTHERLY FLOW WILL CONTINUE TONIGHT AS AN UPPER LEVEL
SHORTWAVE CROSSES NORTHERN OHIO EARLY FRIDAY. SOME SHOWERS MAY BE
FOUND AS IT MOVES EAST DURING THE DAY...BUT I HAVE REMOVED THE
VCSH THAT WAS IN DAYTON TAF FOR TOMORROW IN FAVOR OF ANY PRECIP
REMAINING WELL NORTH OF THE I-70 CORRIDOR. VFR CONDITIONS WITH
FEW-SCT CU AT 5KFT TOMORROW WILL SEE SOME HIGHER CLOUDS AT
12-15KFT THROUGH THE DAY. SOUTHERLY WINDS WILL PICK UP AND COULD
REACH 10KT IN THE AFTERNOON.
OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...CONIGLIO/HICKMAN
NEAR TERM...FRANKS
SHORT TERM...CONIGLIO/HICKMAN
LONG TERM...HATZOS
AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
315 PM CDT WED SEP 16 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 314 PM CDT WED SEP 16 2015
WEAK CONVECTION OVER CLEAR LAKE WILL CONTINUE TO PUSH OFF INTO
MINNESOTA THIS AFTERNOON. HRRR SHOWS ADDITIONAL WEAK/SCATTERED
REDEVELOPMENT...THE DISORGANIZATION LIKELY OWING TO A LACK OF STRONG
FORCING ALOFT. THIS AREA MAY EXPERIENCE SOME ADDITIONAL MORE
ORGANIZED ELEVATED CONVECTION AS A LOW LEVEL JET DEVELOPS THIS
EVENING...HOWEVER THE MAIN FOCUS OF THE JET WILL SHIFT EAST OF THE
CWA. A WAVE ALOFT WILL PROVIDE FOR INCREASING MID LEVEL MOISTURE
WEST RIVER...SHIFTING EAST OVERNIGHT. SOUNDINGS ARE DRY BELOW
10KFT...WITH VERY LIMITED INSTABILITY ALOFT...SUGGESTING SCATTERED
VERY LIGHT SHOWERS WITH THE OCCASIONAL LIGHTING STRIKE. CANADIAN
HIGH PRESSURE NOSING INTO THE CWA THURSDAY WILL ALLOW FOR MORE
AVERAGE DAYTIME TEMPERATURES. MODELS CONTINUE TO GENERATE A RATHER
PROMINENT QPF BULLSEYE WEST RIVER INTO CENTRAL COUNTIES FRIDAY IN
THE VICINITY OF AN INVERTED TROF...WITH FAVORABLE PLACEMENT OF A
SHARED ENERGY AREA AND Q VECTOR BULLSEYE. TO THE EAST...WE WILL SEE
A DRY NORTHEAST FETCH...WHICH WILL LIMIT QPF/POPS. 850MB
TEMPERATURES WILL HAVE BOTTOMED OUT AROUND +5C BY THAT POINT...SO
ANTICIPATE MUCH OF THE FORECAST AREA WILL STRUGGLE TO TOP 60F.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 314 PM CDT WED SEP 16 2015
HIGH PRESSURE WILL BE CENTERED OVER NEBRASKA WHEN THE PERIOD
BEGINS...THEN GETS QUICKLY PUSHED EASTWARD AHEAD OF AN APPROACHING
TROUGH SATURDAY NIGHT. THE TROUGH/FRONT WILL SLOWLY STRENGTHEN AND
LOOKS TO FINALLY TRACK ACROSS THE CWA TUESDAY AND
WEDNESDAY...BECOMING THE FOCUS FOR POTENTIAL PRECIPITATION. BEST
CHANCES WILL BE ACROSS THE EASTERN PART OF THE CWA WHERE SOME
INSTABILITY IS NOTED IN THE MODELS. NOT MUCH IN THE WAY OF UPPER
LEVEL ENERGY...SO WILL KEEP POPS LOW FOR THE TIME BEING.
WILL SEE A GRADUAL WARMING TREND DURING THE FIRST HALF OF THE PERIOD
WITH HIGHS IN THE UPPER 60S AND LOWER 70S SATURDAY...MAINLY IN THE
70S ON SUNDAY...AND IN THE UPPER 70S TO MID 80S MONDAY. HIGHS IN THE
70S TO AROUND 80 WILL BE COMMON TUESDAY AND WEDNESDAY...DEPENDING ON
CLOUD COVER AND POSSIBLE PRECIPITATION. OVERNIGHT LOWS WILL BE IN
THE UPPER 40S TO MID 50S THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1221 PM CDT WED SEP 16 2015
VFR CONDITIONS WILL PREVAIL ACROSS THE AREA THROUGH MIDDAY
THURSDAY. LOOK FOR SOUTH/SOUTHEASTERLY WINDS TO SHIFT TO THE
NORTHWEST AND INCREASE INTO THE 15 TO 30 MPH RANGE THURSDAY
MORNING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...CONNELLY
LONG TERM...PARKIN
AVIATION...PARKIN
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
636 PM CDT THU SEP 17 2015
.AVIATION...
NO SIGNIFICANT CHANGES FOR THIS PERIOD. VFR CONDITIONS WILL
CONTINUE THROUGH THE EVENING AT THE TERMINALS. MVFR/IFR CIGS WILL
DEVELOP OVERNIGHT IN AUSTIN AND SAN ANTONIO...AND BEFORE DAWN AT
DRT. IMPROVEMENT BACK TO VFR BY LATE MORNING AT ALL AIRPORTS.
&&
.PREV DISCUSSION... /ISSUED 246 PM CDT THU SEP 17 2015/
SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
ONLY HIGHLIGHT IN THE SHORT TERM PERIOD WILL BE THE POSSIBILITY OF
LOCALIZED DENSE FOG FRIDAY MORNING FOR THE COASTAL PLAINS AND
EASTERN COUNTIES. RAIN CHANCES WILL CONTINUE TO BE LOW WITH SLIGHTLY
ABOVE NORMAL TEMPERATURES.
THE SYNOPTIC PATTERN REVEALS AN H5 RIDGE CENTERED OVER TEXAS WITH A
LONGWAVE TROUGH SHIFTING ACROSS THE NORTHERN ROCKIES WHILE ANOTHER
TROUGH IS LOCATED OVER FLORIDA. THE RIDGE OVER TEXAS WILL CONTINUE
TO BEAR ITS INFLUENCE AND PERPETUATE THE SLIGHTLY ABOVE NORMAL
TEMPERATURES AND DRY CONDITIONS. ONLY CAVEAT WILL BE ISOLATED LIGHT
SHOWERS ACROSS PORTIONS OF THE COASTAL PLAINS BUT HAVE ONLY
MENTIONED A 15% CHANCE IN THAT LOCATION THIS AFTERNOON. THESE
SHOWERS WILL DISSIPATE QUICKLY AFTER SUNSET.
LOW CLOUDS WILL DEVELOP ONCE AGAIN OVERNIGHT WITH ANOTHER LIKELY
ROUND OF FOG IN THE EASTERN AND COASTAL PLAIN COUNTIES. DEWPOINT
DEPRESSIONS WILL BE 1F OR LESS PER RAP OUTPUT WITH NEAR CALM WINDS.
SREF PROBABILITIES OF <1 MILE VISIBILITIES ARE HIGHER THEN WHAT IT
INDICATED FOR THIS MORNING ALSO. AREAS OF FOG WERE ADDED TO THE
WEATHER FORECAST WITH THE DEVELOPMENT OF DENSE FOG NEEDING TO BE
CLOSELY MONITORED. THE LOW CLOUDS AND FOG THAT DO FROM WILL
DISSIPATE OUT THROUGH THE MID TO LATE MORNING...SIMILAR TO TODAY.
ADDITIONAL CLEARING WILL OCCUR THROUGH THE AFTERNOON HOURS FRIDAY
WITH TEMPERATURES REACHING BACK INTO THE MID TO UPPER 90S.
LONG TERM (SATURDAY THROUGH THURSDAY)...
THE LONG TERM FORECAST WILL CONTINUE TO BE MAINLY DOMINATED BY AN
UPPER LEVEL RIDGE. A QUICKLY MOVING TROUGH WILL PASS NORTH OF THE
RIDGE...ACROSS THE NORTHERN PLAINS FRIDAY AFTERNOON. THIS UPPER
LOW WILL ALLOW A COLD FRONT TO MOVE INTO NORTH TEXAS SATURDAY
AFTERNOON. HOWEVER...WITH THE RIDGE IN PLACE ACROSS SOUTHERN AND
CENTRAL TEXAS...THE FRONT SHOULD STALL SOMEWHERE NEAR THE I-20
CORRIDOR. THE GFS/ECMWF BOTH ARE SHOWING SOME AFTERNOON AND
EVENING CONVECTION ALONG THE FRONT SATURDAY...BUT MOST IF NOT ALL
OF THIS SHOULD STAY TO OUR NORTH CLOSER TO THE FRONT AND WILL NOT
MENTION ANY PRECIP AT THIS TIME FOR THE NORTHERN HILL COUNTRY.
FOR THE REST OF THE EXTENDED FORECAST...MODELS ARE PROGGING
SURFACE DEWPOINTS TO LOWER INTO THE 50S AND LOWER 60S BY SATURDAY
AFTERNOON...CONTINUING EACH AFTERNOON THROUGH THE REST OF THE
PERIOD. HIGH TEMPERATURES WILL BE IN THE LOWER TO MIDDLE 90S WITH
PLEASANT...DRY EVENINGS. LOW TEMPERATURES WILL UPPER 60S TO LOWER
70S ACROSS THE AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 73 95 72 95 71 / 0 - 0 - -
AUSTIN BERGSTROM INTL AIRPORT 71 95 70 94 68 / 0 - 0 - -
NEW BRAUNFELS MUNI AIRPORT 73 96 72 96 69 / 0 - 0 - -
BURNET MUNI AIRPORT 72 94 71 94 69 / 0 0 0 10 -
DEL RIO INTL AIRPORT 75 97 76 96 73 / 0 0 0 - -
GEORGETOWN MUNI AIRPORT 73 95 71 94 70 / 0 0 0 - -
HONDO MUNI AIRPORT 73 96 72 96 68 / 0 0 0 - -
SAN MARCOS MUNI AIRPORT 73 94 72 93 69 / 0 - 0 - -
LA GRANGE - FAYETTE REGIONAL 73 94 71 93 70 / - - 0 - -
SAN ANTONIO INTL AIRPORT 75 95 74 95 71 / 0 0 0 - -
STINSON MUNI AIRPORT 75 96 74 96 71 / 0 - 0 - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...04
PUBLIC SERVICE/DATA COLLECTION...TREADWAY
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
320 PM CDT WED SEP 16 2015
.SHORT TERM...
LOOKS LIKE CONDITIONS ARE A BIT MORE FAVORABLE FOR ISOLATED
THUNDERSTORMS ACROSS THE NORTHWESTERN SOUTH PLAINS THIS AFTERNOON
AND EARLY EVENING. THE LEE SURFACE TROUGH AXIS IS A BIT FARTHER
EAST INTO THE WESTERN SOUTH PLAINS AND A FAIRLY WELL DEVELOPED CU
FIELD HAS APPEARED OVER THE LAST HOUR IN EASTERN NEW MEXICO AND
THE WESTERN COLUMN OF COUNTIES ALONG THE TX/NM BORDER. FORECAST
SOUNDINGS SHOW THAT THERE IS A BIT BETTER INSTABILITY WITH ML AND
SB CAPES RANGING FROM AROUND 500-750 J/KG ALONG THE TROUGH AXIS TO
NEAR 2000 J/KG ACROSS THE NORTHERN ROLLING PLAINS. HOWEVER...THERE
IS A FAIRLY STRONG CAP IN PLACE ACROSS THE EASTERN HALF OF THE
FORECAST AREA SO THE QUESTION BECOMES WHERE A SWEET SPOT COULD
EMERGE FOR THE DEVELOPMENT OF STORMS. LATEST SATELLITE AND RADAR
LOOPS...AS WELL AS A LOOK TO THE WEST FROM THE FORECAST
OFFICE...SHOWS THAT STORMS ARE CLOSE TO INITIATING IN BAILEY
COUNTY/NEAR MULESHOE. BASES ARE EXPECTED TO BE FAIRLY HIGH AT
AROUND 10KFT DUE TO DEEP DAYTIME MIXING SO PRECIPITATION WILL HAVE
TO DEAL WITH QUITE A BIT OF EVAPORATION BEFORE REACHING THE
GROUND. THIS MAY ALSO RESULT IN SOME DOWNBURSTS THAT COULD TRY TO
GET UP TO AROUND 50 MPH SO THAT WILL NEED TO BE WATCHED THROUGH
THE LATE AFTERNOON. NEXT ISSUE IS HOW FAR SOUTHEAST ANY STORMS CAN
MAKE IT. HIGH RESOLUTION MODELS ALL HAVE CONVECTION IN THEM BUT
ARE STRUGGLING WITH HOW FAR SOUTHEAST TO PUSH THE STORMS BEFORE
THEY DISSIPATE. THE HRRR AND NSSL-WRF BOTH HAVE STORMS MAKING IT
CLOSE TO LUBBOCK BUT ALL OTHER MODELS KEEP PRECIPITATION NORTH AND
WEST OF THE CITY. THEY ARE ALL IN AGREEMENT THAT COVERAGE WILL BE
ISOLATED AT BEST. SO...WILL RUN ISOLATED POPS THROUGH 03Z
NORTHWEST OF A TULIA TO PLAINS LINE.
TEMPERATURES TOMORROW MORNING WILL BE A BIT WARMER AS BOUNDARY LAYER
MOISTURE WILL BE A BIT HIGHER ACROSS THE REGION THANKS TO
CONTINUED SOUTHERLY TO SOUTHEASTERLY FLOW AT THE SURFACE. WE WILL
AGAIN SEE THE POSSIBILITY OF THUNDERSTORMS TOMORROW AFTERNOON AGAIN
ALONG AND EAST OF THE SURFACE TROUGH. 12Z RUNS CONTINUE TO KEY ON
THE NORTHWESTERN SOUTH PLAINS TO BE THE MOST FAVORED AREA FOR
CONVECTION AND KEPT POPS HIGHEST ACROSS THIS AREA. THIS INCLUDES A
SLIVER OF LOW END CHANCE POPS IN THERE AS WELL AS COVERAGE CONTINUES
TO BE HIGHER THAN IN PREVIOUS RUNS. HIGH TEMPERATURES WILL BE
FAIRLY CLOSE TO TODAY BUT PERHAPS A SHADE ON THE COOL SIDE THANKS TO
THE INCREASED MOISTURE AND POSSIBLY INCREASED CLOUD COVER AS WELL.
JORDAN
.LONG TERM...
THE UA RIDGE CENTERED SOUTH OF THE SOUTH PLAINS AND ROLLING PLAINS
LATE THIS AFTN...WILL SET THE STAGE FOR MONSOONAL MOISTURE TO BE
CAPABLE OF BENDING IN ACROSS THE REGION COMMENCING TOMORROW AND
PERSISTING INTO EARLY WEEKEND. A NW PACIFIC UA LOW CURRENTLY
MOVING ONSHORE ACROSS OREGON IS PROGGED TO TRANSLATE ENE TO ACROSS
THE NRN PLAINS BY FRIDAY. IT WILL SEND DOWN A SFC TROUGH/SLIGHTLY
BREEZY COLD FRONT THAT IS STILL ON TRACK TO IMPINGE ON THE CWA
FRIDAY NIGHT...WHICH WILL INTERACT WITH AN ALREADY MOIST
ATMOSPHERE /PWATS OF 0.75-1.50 INCHES/ COURTESY OF PERSISTENT SRLY
SFC FLOW. THIS WILL RESULT IN CHANCES OF PRECIP WITH THE GFS AND
ECMWF BEING MOST BULLISH WRT TO THE SPATIAL DISTRIBUTION OF THE
PRECIP /SCATTERED-WIDESPREAD PRECIP/...VERSUS THE MORE
PESSIMISTIC NAM /PRECIP CONFINED TO OFF THE CAPROCK/. IF THE GFS
AND ECMWF ARE INDEED HANDLING THE PRECIP BETTER THAN THE OUTLIER
NAM...GIVEN THE ANTICIPATED PWATS AND DEPENDING ON THE SPEED OF
THE STORMS...COULD SEE BRIEF MODERATE RAINFALL.
PROGRESSIVE FLOW ACROSS THE NRN U.S. TIER WILL RESULT IN THE UA
RIDGE GETTING SHOVED A BIT FARTHER SOUTH AND AWAY FROM THE REGION BY
SATURDAY...AND THUS FLOW ALOFT WILL VEER FROM SWRLY FLOW TO W-NW
FLOW THROUGHOUT THE WEEKEND. THE COLD FRONT/SFC TROUGH IS EXHIBITED
TO STALL JUST SOUTH OF THE CWA SATURDAY AFTN/EVENING...THOUGH COULD
RETURN AS A WARM FRONT WITH AN UPSLOPE SFC REGIME ENVELOPING THE
REGION...COUPLED WITH A BIT OF ISENTROPIC UPGLIDE AND THE PASSAGE OF
A WEAK EMBEDDED IMPULSE ACROSS THE PANHANDLE REGION. EVEN THOUGH
THE MONSOONAL MOISTURE WILL BE THINNING OUT QUITE A BIT BY
SUNDAY...LINGERING PRECIP WILL STILL EXIST AS A SECOND SLIGHTLY
STRONGER UA DISTURBANCE MOVES ACROSS THE CNTRL PLAINS/PANHANDLE
REGION.
THE EMERGENCE OF AMPLIFIED UA RIDGING TO OUR WEST EARLY NEXT WEEK IS
SHOWN TO QUICKLY EXPAND TO ACROSS THE SOUTHERN PLAINS
TUESDAY/WEDNESDAY. WHETHER OR NOT THE BRIEF PERIOD OF NWRLY FLOW
ALOFT AND A POSSIBLE WEAKNESS ALONG THE ERN PERIPHERY OF THE UA
RIDGE IS ENOUGH TO GENERATE RATHER LIGHT QPF SIGNALS ACROSS PORTIONS
OF THE CWA /AS HINTED AT BY THE ECMWF AND THE GFS/ IS
DEBATABLE...AS IT WILL BE HIGHLY DEPENDENT ON THE STRENGTH OF THE
SAID UA RIDGE. WILL OPT TO MAINTAIN NIL POPS BEYOND SUNDAY NIGHT
ATTM.
ABOVE NORM TEMPS EXPECTED THROUGH FRIDAY /90S/...WHERE THEREAFTER
TEMPS REMINISCENT OF FALL WILL OCCUR FOR THE WEEKEND /70S AND 80S/.
TEMPS WILL GRADUALLY WARMUP TO AROUND SEASONAL NORMS THROUGH MID-
WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 64 92 64 90 / 10 20 20 10
TULIA 64 93 65 91 / 10 20 20 20
PLAINVIEW 64 92 65 91 / 10 20 20 20
LEVELLAND 62 92 64 92 / 10 20 20 20
LUBBOCK 66 93 68 93 / 10 20 20 20
DENVER CITY 63 93 65 92 / 10 20 20 20
BROWNFIELD 63 92 66 93 / 10 20 20 20
CHILDRESS 70 97 72 94 / 0 10 20 30
SPUR 65 96 68 94 / 0 0 10 30
ASPERMONT 69 98 71 96 / 0 0 0 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
14/29
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1203 PM CDT WED SEP 16 2015
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...VFR CONDITIONS PREVAIL. PWAT REMAINS ELEVATED AT
AROUND TWO INCHES...WITH ISOLATED SHOWER ACTIVITY AROUND THE CWA.
THE HRRR MODEL SUGGESTS THAT COVERAGE WILL INCREASE SOMEWHAT
THROUGH THE FIRST HALF OF THE AFTERNOON...WITH A SEA BREEZE
DEVELOPING...POSSIBLY AFFECTING HRL AND MFE AS IT MOVES INLAND.
ANY LOCALLY HEAVY RAINSHOWERS COULD TEMPORARILY REDUCE CIGS AND
VSBY BELOW VFR. LIGHTNING NOT OBSERVED NOW...BUT AN EMBEDDED TSTM
OR TWO IS NOT OUT OF THE QUESTION THIS AFTERNOON. SHOULD SEE
CLEARING THIS EVENING WITH FEW TO SCT LOW CLOUDS DEVELOPING
THURSDAY MORNING. OVERALL RAIN CHANCES WILL BE LESS ON THURSDAY AS
TROPICAL MOISTURE TO THE SOUTH MOVES INLAND.
&&
.PREV DISCUSSION... /ISSUED 626 AM CDT WED SEP 16 2015/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...SATELLITE AND RADAR IMAGES AS WELL AS SURFACE
OBSERVATIONS INDICATE CONVECTION DEVELOPING ACROSS PORTIONS OF
NORTHEAST MEXICO AND THE WESTERN GULF OF MEXICO THIS MORNING. SOME
MID LEVEL CLOUDS WERE ACROSS PORTIONS OF THE CWA. CEILINGS WERE
NEAR 5500FT AT KAPY. EXPECT VFR CONDITIONS TO PREVAIL TODAY WITH
BRIEF MVFR CONDITIONS WITH SHOWERS THIS AFTERNOON AS A WEAK 500MB
LOW ACROSS THE SOUTHWEST GULF OF MEXICO CONTINUES TO BRING
MOISTURE ACROSS NORTHEAST MEXICO INTO PORTIONS OF THE RIO GRANDE
VALLEY.
PREV DISCUSSION... /ISSUED 316 AM CDT WED SEP 16 2015/
SHORT TERM /TODAY THROUGH THURSDAY/...DESPITE THE 500MB RIDGE
ACROSS NORTHERN MEXICO INTO TEXAS...THE WEAK 500MB LOW ACROSS THE
SOUTHWEST GULF OF MEXICO CONTINUES TO DRAW MOISTURE ACROSS THE
WESTERN GULF OF MEXICO INTO NORTHEAST MEXICO. SATELLITE AND RADAR
IMAGES CONTINUE TO INDICATE CONVECTION DEVELOPING AND MOVING
ACROSS THE COASTAL SECTIONS OF THE CWA THIS MORNING. BOTH THE NAM
AND GFS PROG ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ACROSS
PORTIONS OF THE CWA TODAY AS LOW TO MID LEVEL MOISTURE REMAINS
HIGH ACROSS NORTHEAST MEXICO AND THE WESTERN GULF OF MEXICO. RAIN
CHANCES SHOULD FINALLY BEGIN TO DIMINISH TONIGHT INTO THURSDAY AS
THE 500MB RIDGE ACROSS WEST TEXAS BRINGS DRIER AIR ALOFT INTO
SOUTH TEXAS AND THE WEAK 500MB LOW ACROSS THE SOUTHWEST GULF OF
MEXICO MOVES INLAND ACROSS EASTERN MEXICO.
LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...A FLAT 500 MB HIGH
PRESSURE IN THE MID LEVELS WILL BE IN PLACE EARLY IN THE LONG
TERM PROVIDING BENIGN WEATHER ACROSS DEEP S TX THROUGH THE
WEEKEND. THIS RIDGE GRADUALLY DRIFTS EASTWARD WITH ITS CENTERED
OVER CENTRAL TEXAS BY SATURDAY INTO SUNDAY. AN ABUNDANT DRY AIR
MASS MOVES OVER THE REGION PROVIDING DRY DAYS ACROSS THE AREA FOR
THE END OF THE WEEK INTO THE WEEKEND. MEAN RH VALUES FALL BELOW 10
PERCENT FROM ~750 UP TO 300 MB WHICH ENSURES A FAIR WEATHER
PATTERN ACROSS THE CWA. STILL LOW LEVEL MOISTURE NEAR THE SURFACE
WILL AID FOR A FEW TO SCT CUMULUS ALONG THE COASTAL COUNTIES FOR
EACH AFTERNOON THROUGH THE WEEKEND. THE LACK OF CONVECTION AND
ABUNDANT DRY AIR WILL PROVIDE FAVORABLE CONDITIONS FOR MORE
DAYTIME HEATING THURSDAY THROUGH FRIDAY WITH HIGH`S IN THE MID TO
UPPER 90S. OVERNIGHT EXPECTING MUCH CLEAR NIGHTS WILL KEEP LOW
TEMPS IN THE LOW TO MID 70S WITH THE COOLER SPOTS ACROSS THE WEST
AND NORTHERN RANCHLANDS.
GFS/ECMWF MODEL GUIDANCE FOR THE 00Z MODEL RUN SHOW POPS REDUCE
TO LESS THAN 15 PERCENT ACROSS THE CWA INTO NEXT WEEK WITH A VERY
WEAK SIGNATURE OF THE WEAK EASTERLY WAVE/LINGERING MOISTURE OVER
THE GULF OF MEXICO. RIDGE IS DEPICTED TO BE IN CONTROL AND BROAD
DOMINATING MOST OF THE REGION AND EXTENDING INTO MX AND THE PAC
COAST. IF THIS PATTERN CONTINUES RIDGE WILL KEEP DEEPER MOISTURE
WITHIN THE PERIPHERY OF THE HIGH WHICH IS FURTHER SOUTH OF THE
CWA. A FEW ISOLATED SHOWERS CAN NOT BE RULED OUT BUT MAINLY
POSSIBLE WITH THE SEA BREEZE BUT SILENT 10 POPS ARE SUFFICIENT.
AS THIS DRY TREND IS WELL NOTED IN THE LAST MODEL RUN... DECIDED
TO LEAN TOWARDS DRIER POPS SUNDAY THROUGH TUESDAY. AS LESS CLOUD
COVER AND CONVECTION IS EXPECTED..LEAN TOWARDS HIGHER TEMPERATURES
ACROSS THE CWA SUNDAY THROUGH TUESDAY WITH A FEW DEGREES HIGHER.
MARINE...TODAY THROUGH THURSDAY...SEAS WERE NEAR 6 FEET WITH
SOUTHEAST WINDS NEAR 14 KNOTS AT BUOY020 EARLY THIS MORNING.
LIGHT TO MODERATE EAST TO SOUTHEAST WINDS WILL PREVAIL ACROSS
THE COASTAL WATERS WITH SURFACE HIGH PRESSURE ACROSS THE EASTERN
UNITED STATES AND A SURFACE TROUGH OF LOW PRESSURE ACROSS THE
CENTRAL UNITED STATES. SWELLS ACROSS THE WESTERN GULF OF MEXICO
APPEAR TO HAVE PEAKED THIS MORNING BUT WILL CONTINUE THE SMALL
CRAFT ADVISORY FOR THE FAR OFFSHORE WATERS THROUGH 7 AM THIS
MORNING FOR HIGH SEAS. LIGHT TO MODERATE EAST TO SOUTHEAST WINDS
WILL PREVAIL ACROSS THE COASTAL WATERS TONIGHT INTO THURSDAY
WITH THE SURFACE TROUGH ACROSS THE CENTRAL U.S. AND HIGH PRESSURE
PREVAILING ACROSS THE EASTERN U.S. COAST.
THURSDAY NIGHT THROUGH TUESDAY...RIDGE BUILDING ACROSS THE REGION
WILL LIMIT THE POTENTIAL FOR RAIN ACROSS THE GULF WATERS THROUGH
MUCH OF THE LONG TERM FORECAST. SURFACE HIGH PRESSURE WITH A WEAK
GRADIENT ACROSS THE GULF WATERS KEEPS AN EAST FETCH OVER THE
NORTHERN GULF. THE GRADIENT REMAINS RELAX THROUGH THE PERIOD
MAINTAINING A LIGHT TO MODERATE FLOW WITH SEAS BETWEEN 2 TO 3 FEET
FOR THE MOST PART. A FEW ISOLATED SHOWERS ARE POSSIBLE BY MONDAY
INTO TUESDAY WEAK WAVE DEVELOPS OVER THE GULF. MODELS SUGGEST THE
DEEPER MOISTURE REMAINING FURTHER SOUTH KEEPING THE GULF WATERS
UNDER A MUCH DRIER AIR MASS.
BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 7 AM CDT THIS
MORNING FOR GMZ170-175.
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
54/52/65
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS SEATTLE WA
845 PM PDT THU SEP 17 2015
.SYNOPSIS...SCATTERED SHOWERS WILL TAPER TONIGHT. DRIER WEATHER WILL
FOLLOW FRIDAY THROUGH SATURDAY NIGHT...THOUGH SYSTEMS BRUSHING THE
AREA COULD BRING A LITTLE RAIN TO THE FAR NORTH AND COAST AT TIMES.
ANOTHER FRONT WILL ARRIVE SUNDAY AND SUNDAY NIGHT. DRY WEATHER IS
LIKELY TUESDAY AND WEDNESDAY.
&&
.SHORT TERM...SHOWERS WILL DECREASE TONIGHT AS A WEATHER SYSTEM
EXITS EAST AND WEAK HIGH PRESSURE MOVES OVER THE AREA. THE BEST
CHANCES FOR SHOWERS WILL BE IN A PUGET SOUND CONVERGENCE ZONE IN
CENTRAL PUGET SOUND AND OVER THE CASCADES THIS EVENING.
MODELS SHOW A FRONT REACHING THE COAST FRIDAY. THE NAM12 SEEMS A
LITTLE TOO FAST AND THE SLIGHTLY SLOWER GFS AND EC SOLUTIONS ARE
PREFERRED. THERE SHOULD BE A LITTLE RAIN AT THE COAST AND OVER THE
OLYMPICS BUT THE INTERIOR LOOKS MAINLY DRY ALTHOUGH THERE IS A
SMALL CHANCE IN THE AFTERNOON AND EVENING.
MOIST ZONAL FLOW ALOFT WILL KEEP MOST OF THE RAIN THREAT NORTH OF
THE FORECAST AREA ON SATURDAY. THE COAST AND FAR NORTH INTERIOR
COULD SEE A LITTLE RAIN BUT OTHER AREAS SHOULD BE DRY. UPPER
HEIGHTS RISE ACROSS THE REGION AND HIGHS SHOULD GO FROM SLIGHTLY
BELOW NORMAL FRIDAY TO NEAR OR SLIGHTLY ABOVE NORMAL ON SATURDAY.
ANOTHER FRONT IS EXPECTED TO REACH THE AREA LATER SUNDAY. RAIN
SHOULD BECOME LIKELY BY AFTERNOON OR EVENING. SCHNEIDER
.LONG TERM...MONDAY THROUGH WEDNESDAY LOOK PRETTY DRY IN BOTH THE
GFS AND EURO MODELS. THERE SHOULD BE SOME SUN EACH DAY AND HIGHS
WILL BE IN THE 60S. THE NEXT SYSTEM ARRIVES ON THE COAST AROUND
WEDNESDAY NIGHT AND WILL PROBABLY SPREAD RAIN INLAND THURSDAY.
BURKE
&&
.AVIATION...FAIRLY MOIST NW FLOW ALOFT WILL CONTINUE OVER W WA
THROUGH FRIDAY EVENING. A PUGET SOUND CONVERGENCE ZONE HAS WEAKENED
AND MOVED OVER THE CASCADES OVER STEVENS PASS. THE PSCZ IS EXPECTED
TO EVENTUALLY DISSIPATE TONIGHT...LEAVING MAINLY MID AND HIGH CLOUDS
OVER THE AREA THIS EVENING. AREAS OF MVFR CIGS ARE EXPECTED TO
DEVELOP AFTER 08Z AND CONTINUE THROUGH 18Z.
A WEAK WARM FRONT WILL SPREAD CLOUDS AND SOME LIGHT RAIN OVER THE
COAST AND STRAIT OF JUAN DE FUCA FRIDAY MORNING THEN ACROSS THE N
INTERIOR FRIDAY AFTERNOON. CIGS ON THE COAST WILL BE MVFR BUT WILL
BE VFR BKN-OVC035-050 OVER THE N INTERIOR. OVER PUGET SOUND AND THE
SW INTERIOR CIGS SHOULD BE BKN-OVC050 AND HIGHER.
KSEA...THE CONVERGENCE ZONE HAS MOVED N OVER STEVENS PASS AND IS NOT
EXPECTED TO BE A FACTOR THE REST OF TONIGHT. VFR CONDITIONS AT 03Z
SHOULD CONTINUE BEYOND 06Z. SOME LOW LEVEL MOISTURE IS EXPECTED TO
BRING CIGS BKN030-040 AFTER MIDNIGHT AND THROUGH 18Z. CIGS DOWN TO
BKN020 ARE NOT OUT OF THE QUESTION. SURFACE WINDS WILL REMAIN
SOUTHERLY 3-7 KT. KAM
&&
.MARINE...A SURFACE RIDGE ALONG THE WA COAST THIS EVENING WILL MOVE
OVER THE INTERIOR EARLY FRIDAY MORNING AS SURFACE TROUGH ASSOCIATED
WITH AN APPROACHING WEAK WARM FRONT BRUSHES THE COASTAL WATERS. THE
SURFACE TROUGH IS EXPECTED TO PUSH WINDS OVER THE COASTAL WATERS
INTO THE SCA RANGE. WITH THE SURFACE RIDGE STILL IN PLACE OVER THE W
WA INTERIOR...WINDS WILL REMAIN BELOW SCA LEVELS.
THE SURFACE RIDGE WILL REMAIN OVER THE W WA INTERIOR THROUGH
SATURDAY. DURING THIS PERIOD LOWER PRESSURE WILL REMAIN JUST N OVER
SOUTHERN B.C. AS A STRONGER WARM FRONT MOVES INLAND ACROSS VANCOUVER
ISLAND. W WA WINDS WILL REMAIN SOUTHERLY BUT IF THE WARM FRONT IS
STRONGER THAN EXPECTED WINDS OVER THE FAR N COULD SNEAK UP INTO THE
SCA RANGE.
ON SUNDAY THE COLD FRONT ASSOCIATED WITH THE SYSTEM WILL SWEEP SE
ACROSS W WA IN THE AFTERNOON. GFS SHOWS PRESSURE GRADIENTS STRONG
ENOUGH FOR SCA S WINDS SUNDAY MORNING OVER THE INTERIOR AHEAD OF THE
FRONT. STRONG ONSHORE FLOW SHOULD DEVELOP BEHIND THE FRONT BY LATE
AFTERNOON. GALE FORCE WESTERLIES LOOK LIKELY FOR THE CENTRAL/E
STRAIT OF JUAN DE FUCA. ONSHORE FLOW GRADUALLY EASE THROUGH MONDAY.
ANOTHER SURFACE RIDGE WILL BUILD OVER THE AREA MONDAY NIGHT. KAM
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 5 AM TO 6 PM PDT FRIDAY FOR COASTAL
WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-
COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM-
COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO
60 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE
OUT 10 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE
SHOALWATER 10 TO 60 NM-COASTAL WATERS FROM POINT GRENVILLE
TO CAPE SHOALWATER OUT 10 NM.
&&
$$
WWW.WEATHER.GOV/SEATTLE
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
[top]
Area Forecast Discussion
National Weather Service Spokane WA
613 PM PDT THU SEP 17 2015
.SYNOPSIS...
Tonight will be cool and showery with the best chance for
precipitation over the central and southern Idaho Panhandle. A
warming trend is expected Friday through the weekend with
temperatures climbing into the 70s Saturday and Sunday. A strong
frontal system will bring windy weather to the region on Sunday.
Next week looks dry Monday through Wednesday with near average
temperatures.
&&
.DISCUSSION...
Evening update to add isolated showers for the next 2-3 hours
across the lower Basin and increase pops for the lower Idaho
Panhandle. We are tracking three midlevel circulations within the
mean trof which will be the primary focus for showers. One is
drifting into NE WA and into the north Idaho Panhandle. A second
is crossing the Palouse and into the lower ID panhandle and the
third is crossing the Cascades. Confidence is lowest with the
latter crossing the Cascades but general trends with the HRRR are
for a few isolated showers through 03z. As of 6PM...we have only
seen one shower in northern Grant County. Precipitation amounts
with this activity will be light and generally range between a
trace and 0.01". Several hundreths will be possible from Whitman
to lower Shoshone County where the heavier concentration of shower
activity is ongoing. The threat for thunder has ended but some of
these showers could bring a quick 0.05 to 0.10". Further north
into NE WA and the northern ID Panhandle, rainfall amounts will be
around 0.05" or less. We will be monitoring the potential for fog
in these valleys tonight with perhaps some stratus development
in rising terrain of the West Plains. Overnight lows were cooled
along the Hwy 97 corridor where dewpoints are down and skies will
have a better chance of clearing. /sb
&&
.AVIATION...
00Z TAFS: Several small scale disturbances passing through the
region will keep a chance for showers through 04z with KPUW-KLWS
carrying the highest threat. As pcpn ends this evening...we will
be looking at the potential for fog in the northeastern valleys
and stratus developing btwn KGEG-KCOE. Confidence is low at this
point for restrictions so TAFS only carrying scattered decks near
1K ft AGL. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 46 64 48 70 53 76 / 20 10 10 0 10 0
Coeur d`Alene 46 64 46 70 50 75 / 20 10 10 0 10 10
Pullman 44 66 46 71 50 78 / 40 10 0 0 0 0
Lewiston 48 73 51 77 55 84 / 30 10 0 0 0 0
Colville 46 65 46 71 49 78 / 20 20 10 10 10 10
Sandpoint 43 62 43 67 46 73 / 20 20 10 0 10 10
Kellogg 45 63 44 67 48 74 / 50 20 10 0 10 0
Moses Lake 45 71 48 77 53 82 / 20 10 10 0 0 0
Wenatchee 51 73 55 79 59 80 / 20 10 10 0 0 10
Omak 43 71 50 76 53 80 / 10 10 10 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1056 PM CDT THU SEP 17 2015
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 250 PM CDT THU SEP 17 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW
PRESSURE OVER NORTHWEST ONTARIO...AND A COLD FRONT EXTENDING
SOUTHWEST ACROSS WESTERN MINNESOTA TO THE CENTRAL PLAINS. A BAND OF
SHOWERS AND STORMS ASSOCIATED WITH MID-LEVEL MOISTURE TRANSPORT AND
WEAK SHORTWAVE IMPULSES HAVE BEEN SLOWLY WEAKENING EARLY THIS
AFTERNOON AS THEY RUN INTO A MORE STABLE AIRMASS OVER CENTRAL AND
EASTERN WI. BUT SOME OF THIS RAIN SHOULD SURVIVE THE TRIP INTO
NORTHEAST WI. HOWEVER...THE RAIN AND CLOUD COVER HAVE HELD BACK
TEMPERATURES ACROSS MUCH OF WESTERN AND CENTRAL WISCONSIN...THEREBY
PREVENTING A SIGNFICANT RISE OF INSTABILITY AND REDUCING THE RISK OF
SEVERE WEATHER. THE BEST INSTABILITY RESIDES OVER MINNESOTA JUST
AHEAD OF THE FRONT WHERE STORMS ARE ANTICIPATED TO REDEVELOP LATER
THIS AFTERNOON. AS THE FRONT MOVES EAST TONIGHT...THUNDERSTORM
IMPACTS ARE THE MAIN FORECAST CONCERN.
TONIGHT...THE COLD FRONT WILL MOVE EAST....ACROSS WESTERN AND
CENTRAL WISCONSIN THIS EVENING...AND EASTERN WISCONSIN OVERNIGHT.
AHEAD OF THE FRONT...WILL HAVE IMPRESSIVE MOISTURE TRANSPORT WITH
PWATS BETWEEN 1.5 AND 2.0 INCHES AND ELEVATED CAPES AROUND 1000
J/KG...THOUGH THINK THE ATMOSPHERE WILL GET WORKED OVER A LITTLE BY
THIS AFTERNOONS CONVECTION. SO THE SEVERE THREAT DOES NOT LOOK AS
IMPRESSIVE AS YESTERDAY GIVEN THE MARGINAL INSTABILITY...WHICH
MATCHES SPC/S ASSESSMENT. STILL THOUGH...A FEW STRONG STORMS
CAPABLE OF PRODUCING STRONG STRAIGHT LINE WINDS CANNOT BE RULED OUT
THIS EVENING OVER CENTRAL AND NORTH-CENTRAL WISCONSIN AS CONVECTION
ROLLS IN FROM THE WEST. THE MAIN THREAT WILL BE HEAVY RAINFALL
HOWEVER. UPSTREAM OBS OVER WESTERN WISCONSIN FROM EARLIER TODAY
REPORTED UPWARDS OF 2.5 INCHES OF RAINFALL. GIVEN THE HIGH PWATS
AND SLOW MOVEMENT OF THE CONVECTION...THINK ISOLATED AMOUNTS COULD
REACH THIS AMOUNT. THE CONVECTION WILL BE WEAKENING AS IT MOVES
INTO EASTERN WISCONSIN LATE IN THE EVENING AND OVERNIGHT WHERE
RAINFALL POTENTIAL IS NOT NEARLY AS HIGH. LOW CLOUDS WILL LIKELY
LINGER BEHIND THE FRONT EVEN AS WINDS SHIFT TO THE NW. AS A
RESULT...LOWS SHOULD ONLY FALL INTO THE UPPER 50S WEST TO MID 60S
EAST.
FRIDAY...WILL LEAVE A SLIGHT CHANCE OF A SHOWER ALONG THE LAKE SHORE
AT THE START OF THE MORNING. BUT OTHERWISE...THINK THE SHOWER
ACTIVITY WILL HAVE PASSED TO THE EAST OF THE REGION BY 12Z AS THE
FRONT MOVES OVER LAKE MICHIGAN. THEN A DRY PERIOD SHOULD ENSUE
THROUGH AT LEAST MID-AFTERNOON AS NORTHWEST WINDS BRING IN DRIER
AIR. BY LATE AFTERNOON...THE RIGHT REAR QUAD OF A JETSTREAK
COMBINED WITH MID-LEVEL FGEN WILL PROMOTE A BAND OF LIGHT RAIN
LIFTING NORTHWARD TOWARDS NORTH-CENTRAL WI. BUT THE NEXT ROUND OF
PRECIP SHOULD MAINLY HOLD OFF UNTIL FRIDAY NIGHT. HIGHS COOLING OFF
ON FRIDAY INTO THE MID 60S NORTH TO MID 70S SOUTH.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 250 PM CDT THU SEP 17 2015
PCPN TRENDS AND QPF AMOUNTS FRIDAY NIGHT INTO SATURDAY MORNING
ARE THE MAIN FCST CONCERNS.
MODELS HAVE COME INTO FAIRLY GOOD AGREEMENT ON THE FRIDAY NIGHT
SYSTEM...WITH A DEEPENING CYCLONE TRACKING NE THROUGH SOUTHERN
LAKE MICHIGAN...AS A POTENT S/W TROF MOVES THROUGH THE WSTRN
GREAT LAKES. STRONG DYNAMIC FORCING...COMBINED WITH PRECIPITABLE
WATER VALUES OF 1-1.5 INCHES...WILL LEAD TO A SIGNIFICANT RAINFALL
ACROSS ALL BUT THE NW PART OF THE CWA. HEAVY RAINFALL...WITH
AMOUNTS IN EXCESS OF AN INCH...ARE POSSIBLE IN THE FOX VALLEY/
LAKESHORE AREAS. AFTER LOOKING AT PROGS OF ELEVATED INSTABILITY...
WILL CONFINE TSTM CHANCES TO ONLY OUR SE COUNTIES. LINGERING
SHOWERS SHOULD QUICKLY EXIT NE WI EARLY SATURDAY MORNING...WITH
DECREASING CLOUDS THROUGH THE DAY. A BRIEF PERIOD OF STRONG GUSTY
NE-N WINDS IS EXPECTED OVER THE FOX VALLEY AND LAKESHORE AREAS
LATE FRIDAY NIGHT INTO SATURDAY MORNING...AND A SMALL CRAFT
ADVISORY WILL LIKELY BE NEEDED.
HIGH PRESSURE WILL BRING DRY CONDITIONS FROM SATURDAY AFTERNOON
THROUGH TUESDAY. HAVE ADDED A MENTION OF PATCHY FOG TO THE
LATE SATURDAY NIGHT FCST.
THERE IS A SMALL CHANCE OF TSTMS WED-THU AS WEAK FRONTAL BOUNDARY
SAGS TOWARD NORTHERN WI. HOWEVER...THE ECMWF KEEPS A STRONG UPPER
RIDGE IN PLACE...AND HAS THE FRONT REMAINING NORTH OF THE WI/MI
BORDER. THUS...WILL ONLY HAVE SLGT CHC/CHC POPS AT THIS TIME.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1055 PM CDT THU SEP 17 2015
SHOWERS AND THUNDERSTORMS WILL END TONIGHT AS A COLD
FRONT MOVES THROUGH THE AREA. IFR CEILINGS AND FOG ARE POSSIBLE
LATE TONIGHT FOR AWHILE AFTER THE RAIN ENDS. CLOUDS SHOULD DIMINISH
EARLY FRIDAY WITH VFR WEATHER IN THE AFTERNOON.CLOUDS WILL INCREASE
FRIDAY NIGHT WITH SHOWERS LIKELY OVER EAST CENTRAL WISCONSIN.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
623 PM CDT THU SEP 17 2015
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 250 PM CDT THU SEP 17 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW
PRESSURE OVER NORTHWEST ONTARIO...AND A COLD FRONT EXTENDING
SOUTHWEST ACROSS WESTERN MINNESOTA TO THE CENTRAL PLAINS. A BAND OF
SHOWERS AND STORMS ASSOCIATED WITH MID-LEVEL MOISTURE TRANSPORT AND
WEAK SHORTWAVE IMPULSES HAVE BEEN SLOWLY WEAKENING EARLY THIS
AFTERNOON AS THEY RUN INTO A MORE STABLE AIRMASS OVER CENTRAL AND
EASTERN WI. BUT SOME OF THIS RAIN SHOULD SURVIVE THE TRIP INTO
NORTHEAST WI. HOWEVER...THE RAIN AND CLOUD COVER HAVE HELD BACK
TEMPERATURES ACROSS MUCH OF WESTERN AND CENTRAL WISCONSIN...THEREBY
PREVENTING A SIGNFICANT RISE OF INSTABILITY AND REDUCING THE RISK OF
SEVERE WEATHER. THE BEST INSTABILITY RESIDES OVER MINNESOTA JUST
AHEAD OF THE FRONT WHERE STORMS ARE ANTICIPATED TO REDEVELOP LATER
THIS AFTERNOON. AS THE FRONT MOVES EAST TONIGHT...THUNDERSTORM
IMPACTS ARE THE MAIN FORECAST CONCERN.
TONIGHT...THE COLD FRONT WILL MOVE EAST....ACROSS WESTERN AND
CENTRAL WISCONSIN THIS EVENING...AND EASTERN WISCONSIN OVERNIGHT.
AHEAD OF THE FRONT...WILL HAVE IMPRESSIVE MOISTURE TRANSPORT WITH
PWATS BETWEEN 1.5 AND 2.0 INCHES AND ELEVATED CAPES AROUND 1000
J/KG...THOUGH THINK THE ATMOSPHERE WILL GET WORKED OVER A LITTLE BY
THIS AFTERNOONS CONVECTION. SO THE SEVERE THREAT DOES NOT LOOK AS
IMPRESSIVE AS YESTERDAY GIVEN THE MARGINAL INSTABILITY...WHICH
MATCHES SPC/S ASSESSMENT. STILL THOUGH...A FEW STRONG STORMS
CAPABLE OF PRODUCING STRONG STRAIGHT LINE WINDS CANNOT BE RULED OUT
THIS EVENING OVER CENTRAL AND NORTH-CENTRAL WISCONSIN AS CONVECTION
ROLLS IN FROM THE WEST. THE MAIN THREAT WILL BE HEAVY RAINFALL
HOWEVER. UPSTREAM OBS OVER WESTERN WISCONSIN FROM EARLIER TODAY
REPORTED UPWARDS OF 2.5 INCHES OF RAINFALL. GIVEN THE HIGH PWATS
AND SLOW MOVEMENT OF THE CONVECTION...THINK ISOLATED AMOUNTS COULD
REACH THIS AMOUNT. THE CONVECTION WILL BE WEAKENING AS IT MOVES
INTO EASTERN WISCONSIN LATE IN THE EVENING AND OVERNIGHT WHERE
RAINFALL POTENTIAL IS NOT NEARLY AS HIGH. LOW CLOUDS WILL LIKELY
LINGER BEHIND THE FRONT EVEN AS WINDS SHIFT TO THE NW. AS A
RESULT...LOWS SHOULD ONLY FALL INTO THE UPPER 50S WEST TO MID 60S
EAST.
FRIDAY...WILL LEAVE A SLIGHT CHANCE OF A SHOWER ALONG THE LAKE SHORE
AT THE START OF THE MORNING. BUT OTHERWISE...THINK THE SHOWER
ACTIVITY WILL HAVE PASSED TO THE EAST OF THE REGION BY 12Z AS THE
FRONT MOVES OVER LAKE MICHIGAN. THEN A DRY PERIOD SHOULD ENSUE
THROUGH AT LEAST MID-AFTERNOON AS NORTHWEST WINDS BRING IN DRIER
AIR. BY LATE AFTERNOON...THE RIGHT REAR QUAD OF A JETSTREAK
COMBINED WITH MID-LEVEL FGEN WILL PROMOTE A BAND OF LIGHT RAIN
LIFTING NORTHWARD TOWARDS NORTH-CENTRAL WI. BUT THE NEXT ROUND OF
PRECIP SHOULD MAINLY HOLD OFF UNTIL FRIDAY NIGHT. HIGHS COOLING OFF
ON FRIDAY INTO THE MID 60S NORTH TO MID 70S SOUTH.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 250 PM CDT THU SEP 17 2015
PCPN TRENDS AND QPF AMOUNTS FRIDAY NIGHT INTO SATURDAY MORNING
ARE THE MAIN FCST CONCERNS.
MODELS HAVE COME INTO FAIRLY GOOD AGREEMENT ON THE FRIDAY NIGHT
SYSTEM...WITH A DEEPENING CYCLONE TRACKING NE THROUGH SOUTHERN
LAKE MICHIGAN...AS A POTENT S/W TROF MOVES THROUGH THE WSTRN
GREAT LAKES. STRONG DYNAMIC FORCING...COMBINED WITH PRECIPITABLE
WATER VALUES OF 1-1.5 INCHES...WILL LEAD TO A SIGNIFICANT RAINFALL
ACROSS ALL BUT THE NW PART OF THE CWA. HEAVY RAINFALL...WITH
AMOUNTS IN EXCESS OF AN INCH...ARE POSSIBLE IN THE FOX VALLEY/
LAKESHORE AREAS. AFTER LOOKING AT PROGS OF ELEVATED INSTABILITY...
WILL CONFINE TSTM CHANCES TO ONLY OUR SE COUNTIES. LINGERING
SHOWERS SHOULD QUICKLY EXIT NE WI EARLY SATURDAY MORNING...WITH
DECREASING CLOUDS THROUGH THE DAY. A BRIEF PERIOD OF STRONG GUSTY
NE-N WINDS IS EXPECTED OVER THE FOX VALLEY AND LAKESHORE AREAS
LATE FRIDAY NIGHT INTO SATURDAY MORNING...AND A SMALL CRAFT
ADVISORY WILL LIKELY BE NEEDED.
HIGH PRESSURE WILL BRING DRY CONDITIONS FROM SATURDAY AFTERNOON
THROUGH TUESDAY. HAVE ADDED A MENTION OF PATCHY FOG TO THE
LATE SATURDAY NIGHT FCST.
THERE IS A SMALL CHANCE OF TSTMS WED-THU AS WEAK FRONTAL BOUNDARY
SAGS TOWARD NORTHERN WI. HOWEVER...THE ECMWF KEEPS A STRONG UPPER
RIDGE IN PLACE...AND HAS THE FRONT REMAINING NORTH OF THE WI/MI
BORDER. THUS...WILL ONLY HAVE SLGT CHC/CHC POPS AT THIS TIME.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 623 PM CDT THU SEP 17 2015
A COLD FRONT WILL BRING SHOWERS AND THUNDERSTORMS TO THE AREA
THIS EVENING. IFR CEILINGS AND FOG ARE POSSIBLE LATER TONIGHT FOR
AWHILE AFTER THE RAIN ENDS. CLOUDS SHOULD DIMINISH EARLY FRIDAY
WITH VFR WEATHER IN THE AFTERNOON.CLOUDS WILL INCREASE FRIDAY
NIGHT WITH SHOWERS LIKELY OVER EAST CENTRAL WISCONSIN.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......RDM
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 232 PM CDT WED SEP 16 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A COLD
FRONT STRETCHING FROM NORTHWEST MINNESOTA TO THE PANHANDLE OF TEXAS
EARLY THIS AFTERNOON. QUIET CONDITIONS ARE PREVAILING ACROSS THE
REGION OTHER THAN SOME MID AND HIGH CLOUDS PASSING OVERHEAD ON THE
LEADING EDGE OF A MORE MOISTURE-RICH AIRMASS. THE FRONTAL ZONE IS
ALSO LARGELY INACTIVE DUE TO MID-LEVEL CAPPING. EVEN FARTHER
UPSTREAM...LOW PRESSURE IS MOVING EAST OVER NORTHERN WYOMING ON THE
LEADING EDGE OF THE WESTERN NOAM TROUGH. AS THE LOW PRESSURE SYSTEM
AND COLD FRONT MOVE EAST...THE POTENTIAL FOR SHOWERS AND STORMS IS
THE MAIN FORECAST CONCERN IN THE SHORT-TERM.
TONIGHT...LOW PRESSURE WILL MOVE NORTHEAST ACROSS THE DAKOTAS TO THE
BORDER OF MINNESOTA WHILE THE COLD FRONT REMAINS RELATIVELY
STATIONARY. AHEAD OF THESE SYSTEMS...SOUTHWEST WINDS WILL PULL UP
MID-LEVEL DRY AIR ACROSS THE REGION FOR THE EVENING...WHICH LOOKS
MOSTLY CLEAR AND MILD. BUT MODELS APPEAR UNANIMOUS IN DEVELOPING A
SHORTWAVE IMPULSE OVERNIGHT AND PUSHING IT INTO NORHTWEST WISCONSIN
BY 12Z. THIS WAVE IN CONCERT WITH MID-LEVEL MOISTURE ADVECTION AND
STEEP MID-LEVEL LAPSE RATES WILL BRING A CHANCE OF ELEVATED SHOWERS
AND STORMS TO CENTRAL AND NORTH-CENTRAL WI LATE. BEST CHANCES WILL
BE OVER N-C WI CLOSEST TO THE MID-LEVEL WAVE. LOCATIONS FURTHER
EAST SHOULD ENJOY A MOSTLY CLEAR NIGHT. LOWS WILL MAINLY FALL INTO
THE LOW TO MID 60S.
THURSDAY...SCATTERED SHOWERS AND STORMS MAY BE ONGOING EARLY IN THE
MORNING OVER CENTRAL AND NORTH-CENTRAL WI. FORCING VIA SHORTWAVE
ENERGY WILL LIFT TO THE NORTHEAST BY EARLY AFTERNOON SO THINK THE
COVERAGE OF ANY CONVECTION WILL BE DECREASING BY MID TO LATE
MORNING. MANY LOCATIONS IN THIS AREA ARE LIKELY TO SEE A BREAK IN
THE SHOWER ACTIVITY...BUT ITS HARD TO DETERMINE HOW LINGERING CLOUD
COVER WILL DISRUPT THE HEATING CURVE. THE ELEVATED NATURE OF THE
CONVECTION WOULD ARGUE FOR AT LEAST SOME BREAKS IN THE
CLOUDS...WHICH SHOULD BE SUFFICIENT FOR TEMPS TO RISE INTO THE UPPER
70S. WITH DEWPOINTS RISING INTO THE MID TO UPPER 60S...ML CAPES
COULD REACH INTO THE 1000-1500 J/KG RANGE WITH LITTLE CAP BY LATE
AFTERNOON. AS A RESULT...THINK SHOWERS AND THUNDERSTORMS WILL
REDEVELOP DURING THE MID TO LATE AFTERNOON HOURS...MAINLY OVER
CENTRAL AND NORTH-CENTRAL WI...BUT A FEW STORMS COULD FIRE FURTHER
EAST. POTENTIAL FOR STRONG TO SEVERE STORMS IS POSSIBLE BY THIS
TIME AS WIND FIELDS STRENGTHEN ALOFT. MORE ORGANIZED CONVECTION
COULD ALSO BE APPROACHING FROM THE NORTHWEST BY EARLY IN THE
EVENING. DAMAGING WINDS AND HEAVY RAINFALL WILL BE THE MAIN THREATS.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 232 PM CDT WED SEP 16 2015
MAIN FCST CONCERN IS SVR TSTM POTENTIAL THU EVG...AND PCPN TRENDS
THROUGH SATURDAY MORNING.
SHOWERS AND TSTMS WILL BE ON THE INCREASE THURSDAY EVG...AS A S/W
TROF...RRQ OF AN UPPER LEVEL JET AND COLD FRONT IMPACT THE REGION.
ALTHOUGH THE BEST THREAT SHOULD OCCUR TO OUR WEST EARLIER IN THE
DAY...CAPE AROUND 1000 J/KG AND DEEP LAYER SHEAR OF 25-30 KTS
MAY SUPPORT ISOLD STG/SVR TSTMS OVER NC/C WI INTO THE EARLY EVG.
SHOWERS WILL DECREASE FROM WEST TO EAST LATE THU NGT INTO EARLY
FRIDAY...RESULTING IN A BRIEF BREAK IN THE PCPN MIDDAY.
A POTENT NEGATIVELY-TILTED S/W TROF IS EXPECTED TO INDUCE
CYCLOGENESIS ALONG THE LINGERING FRONTAL BOUNDARY FRIDAY NIGHT...
WITH THE DEEPENING SFC LOW TRACKING THROUGH SE WI AND LOWER
MICHIGAN. MODELS HAVE TRENDED FARTHER WEST AND STRONGER WITH
THIS SYSTEM...SO HAVE RAISED POPS TO LIKELY NW AND CATEGORICAL
SE. THE GFS/NAM MODELS SHOW TWO QPF MAXS...ONE OVER SE/EC WI
IN ASSOCIATION WITH A REGION OF STG ISENT LIFT...AND ANOTHER
IN WC/NC WI DUE TO THE UPPER DEFORMATION ZONE. HAVE ATTEMPTED
TO DEPICT THIS PATTERN IN THE QPF GRIDS...THOUGH AMOUNTS MAY
NEED TO BE RAISED WITH SUBSEQUENT FCSTS. LINGERING SHOWERS
SHOULD TAPER OFF EARLY SATURDAY...FOLLOWED BY DECREASING CLOUDS
IN THE AFTERNOON.
HIGH PRESSURE WILL BUILD INTO THE REGION FOR THE END OF THE
WEEKEND AND BEGINNING OF THE NEXT WORK WEEK...LEADING TO
A PERIOD OF PLEASANT WEATHER WITH ABUNDANT SUNSHINE AND
SEASONABLE TEMPERATURES. A WEAK COLD FRONT MAY BRING A
CHANCE OF SHOWERS AND TSTMS TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1153 AM CDT WED SEP 16 2015
A COLD FRONT OVER THE NORTHERN PLAINS WILL MOVE INTO THE
NORTHERN MISSISSIPPI ON THURSDAY. AHEAD OF THE FRONT...A TIGHTENING
PRESSURE GRADIENT WILL LEAD TO LOW LEVEL WIND SHEAR DEVELOPING EARLY
THIS EVENING. OTHERWISE...SHOULD ONLY SEE AN INFLUX OF MID AND HIGH
CLOUDS AFTER MIDNIGHT TONIGHT. A CHANCE OF SHOWERS AND A FEW
THUNDERSTORMS WILL INCREASE ON THURSDAY MORNING AS MOISTURE STREAMS
INTO THE REGION. COVERAGE IS ONLY EXPECTED TO BE SCATTERED IN
NATURE...SO LEFT OUT OF TAFS UNTIL DETAILS CAN GET BETTER PINNED
DOWN.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS TUCSON AZ
250 AM MST FRI SEP 18 2015
.SYNOPSIS...ISOLATED SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND
EVENING...MAINLY SOUTHEAST OF TUCSON. THEREAFTER...A GRADUAL
INCREASE IN MOISTURE WILL BRING SCATTERED SHOWERS AND STORMS MAINLY
FROM TUCSON SOUTH AND EAST OVER THE WEEKEND. MORE WIDESPREAD SHOWERS
AND ISOLATED THUNDERSTORMS ARE THEN EXPECTED EARLY NEXT WEEK.
TEMPERATURES WILL BE NEAR SEASONAL NORMALS THROUGH THIS WEEKEND
BEFORE LOWERING TO BELOW NORMAL VALUES EARLY NEXT WEEK.
&&
.DISCUSSION...SW FLOW ALOFT OVER THE STATE WITH AREAS OF CIRRUS
PASSING THRU. PRECIPITABLE WATER VALUES THIS MORNING RANGED FROM
0.50" IN WRN PIMA COUNTY TO 1"-1.25" FROM TUCSON EAST WITH HIGHER
VALUES LURKING ACROSS NW MEXICO. OVER THE NEXT COUPLE OF DAYS THERE
WILL BE A GRADUAL INCREASE IN MOISTURE ACROSS THE AREA AS FLOW ALOFT
BECOMES MORE SOUTHERLY AS AN UPPER LOW...CURRENTLY ABOUT 800 MILES
WEST OF LA...DROPS SOUTH TO AROUND 600 MILES WEST OF BAJA SPUR BY
SATURDAY AFTERNOON. DEEPER TROPICAL MOISTURE IS THEN POISED TO
SPREAD ACROSS THE AREA EARLY NEXT WEEK BRINGING A REALLY GOOD CHANCE
OF WIDESPREAD RAIN...WHICH MAY BE HEAVY AT TIMES...ALONG WITH
EMBEDDED THUNDERSTORMS. THIS LIKELY COULD BE A MONSOON SAVER AS MOST
AREAS ARE STILL RUNNING BELOW NORMAL FOR THE SEASON.
FOR TODAY...LATEST RUNS OF THE HRRR ALONG WITH UOFA WRF RUNS ARE
INDICATING ISOLATED STORMS EAST OF A WILLCOX TO NOGALES LINE THIS
AFTERNOON INTO EARLY THIS EVENING.
SATURDAY...AREAL COVERAGE OF ISOLATED TO SCATTERED STORMS WILL
EXPAND WEST TO THE TUCSON AREA WITH LOCALLY HEAVY RAINERS ALONG THE
INTERNATIONAL BORDER.
SUNDAY...BEST CHANCE OF SHOWERS/STORMS WILL BE ACROSS PIMA...COCHISE
AND SANTA CRUZ COUNTIES WITH WESTERN/CENTRAL PIMA COUNTY HAVING THE
BEST SHOT OF SOME HEAVY RAINERS AS A WEAK TROF PASSES THROUGH.
MONDAY AND TUESDAY...THE ABOVE MENTIONED UPPER LOW WEST OF THE BAJA
SPUR WILL BE LIFTING TOWARD THE DESERT SW...AND BRINGING ADDED UPPER
DYNAMICS ACROSS THE STATE. AREAS OF MODERATE TO LOCALLY HEAVY RAIN
ARE POSSIBLE MONDAY INTO TUESDAY. WHERE THE HEAVY RAIN WILL
FALL...TIMING AND AMOUNTS ARE STILL UNCERTAIN THIS FAR OUT. IN ANY
EVENT POPS/QPF VALUES WERE RAISED ACROSS THE AREA. ALL OF THIS WILL
BE FINE TUNED THROUGH THE WEEKEND.
WEDNESDAY AND THURSDAY...DRYING OUT BUT STILL ENOUGH MOISTURE
AROUND FOR A SLIGHT CHANCE OF STORMS ACROSS EASTERN AREAS.
AT OR SLIGHTLY ABOVE NORMAL HIGH TEMPERATURES TODAY AND THROUGH THE
WEEKEND. CLOUD COVER AND SHOWERS WILL KEEP TEMPERATURES BELOW NORMAL
MONDAY AND TUESDAY. WARMER WEDNESDAY AND THURSDAY.
&&
.AVIATION...VALID THRU 19/12Z.
ISOLATED -TSRA/-SHRA WILL OCCUR SOUTH-TO-SOUTHEAST OF KTUS INTO
EARLY SATURDAY MORNING WITH DRY CONDITIONS CONTINUING ELSEWHERE. THE
CHANCE OF A SHOWER OR THUNDERSTORM NEAR THE KOLS/KDUG TERMINALS IS
TOO LOW TO INCLUDE IN THE TAFS. OTHERWISE...EXPECT A FEW TO BROKEN
CLOUDS AROUND 8-12K FT AGL AND SCATTERED TO OVERCAST CLOUDS ABOVE
20K FT AGL THROUGH THE PERIOD. SURFACE WIND WILL MAINLY BE LESS THAN
10 KTS INTO EARLY SATURDAY MORNING. AVIATION DISCUSSION NOT UPDATED
FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...ISOLATED THUNDERSTORMS WILL OCCUR SOUTH-TO-SOUTHEAST
OF TUCSON THROUGH TONIGHT WITH DRY CONDITIONS CONTINUING ELSEWHERE.
EXPECT ISOLATED TO SCATTERED THUNDERSTORMS FROM TUCSON EAST AND
SOUTH SATURDAY...THEN SCATTERED THUNDERSTORMS WILL PREVAIL ACROSS
MUCH OF THE AREA SUNDAY. SCATTERED TO PERHAPS NUMEROUS SHOWERS AND
THUNDERSTORMS SHOULD THEN OCCUR MONDAY INTO TUESDAY. THERE WILL
STILL BE ENOUGH MOISTURE FOR AT LEAST A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS WEDNESDAY...THEN DRY CONDITIONS ARE FORECAST ACROSS
MUCH OF THE AREA THURSDAY. GUSTY OUTFLOWS WILL BE POSSIBLE WITH
THUNDERSTORMS. OTHERWISE...20-FOOT WINDS WILL GENERALLY BE TERRAIN
DRIVEN AND LESS THAN 15 MPH INTO THE MIDDLE OF NEXT WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
418 AM EDT FRI SEP 18 2015
.DISCUSSION...
...LOCALLY HEAVY RAIN POSSIBLE...FLOOD WATCH CONTINUES ALONG THE
COAST...
CURRENT...07Z MSAS ANALYSIS INDICATES SFC LOW IS STARTING TO DEVELOP
OFFSHORE FROM THE NE FL COAST WITH NW WINDS AROUND THE DEVELOPING
SFC LOW PRESSURE CENTER ACROSS NRN PORTIONS OF E CENTRAL FL EARLY
THIS MORNING. IT APPEARS THIS LOW WILL BECOME THE DOMINANT LOW AS A
WEAKER LOW PRESSURE AREA MOVES TWD SW FL COAST LATER TODAY.
TODAY...00Z GFS KEEPS DEEP MOISTURE OVER THE AREA WITH PRECIPITABLE
WATER VALUES FROM 2.1 TO 2.3 INCHES WHICH SHOULD ALLOW FOR ONE MORE
AFTERNOON WITH THE THREAT OF LOCALLY HEAVY RAINFALL AMOUNTS. IT
APPEARS TWO AREAS WILL BE FAVORED FOR LOCALLY HEAVY RAIN...THE FIRST
ACROSS OKEECHOBEE COUNTY AND THE TREASURE COAST WHERE THE GFS AND
NAM BOTH INDICATE AFTERNOON CONVECTION AHEAD OF THE WEAK LOW
APPROACHING SW FL. HRRR HAS CONVECTION A BIT FARTHER SOUTH FAVORING
MARTIN COUNTY BY MID AFTERNOON. ACROSS NRN SECTIONS LOW LVL FLOW HAS
STARTED TO RESPOND TO THE LOW PRESSURE AREA DEVELOPING OFFSHORE WITH
A SURGE OF STRONGER LOW LVL N/NNE LOW LVL FLOW ON THE BACK SIDE OF
THE LOW PRESSURE AREA FORECAST TO PUSH SOME CONVECTION SOUTH TOWARD
VOLUSIA COUNTY IN THE AFTERNOON. WILL LOWER RAIN CHANCES SOME WEST OF
ORLANDO BUT STILL FROM 50-60 PCT WITH SCATTERED TO NUMEROUS SHOWERS
AND ISOLATED STORMS EXPECTED THIS AFTN WITH DAYTIME HEATING. WILL
LEAVE THE FLOOD WATCH AS IS WITH COASTAL AREAS HAVING SEEN THE
HIGHEST RAINFALL TOTALS THE LAST SEVERAL DAYS AND IT WOULD NOT TAKE
TOO MUCH MORE RAIN TO CAUSE MINOR FLOODING ISSUES. WILL KEEP HIGH
TEMPS GENERALLY IN THE MID 80S WITH SOME BREAKS OF SUNSHINE THIS
MORNING. WITH LIGHT TO CALM WINDS ACROSS THE TREASURE COAST AHEAD OF
THE NW FLOW TO THE NORTH AND LOTS OF LOW LVL AND GROUND MOISTURE...
FOG HAS DEVELOPED AT VERO BEACH AND FT PIERCE. THE FOG SHOULD
DISSIPATE NOT TOO LONG AFTER SUNRISE BUT WILL HAVE TO SEE IF ANY FOG
DEVELOPMENT ENSUES FURTHER NORTH WHERE STRATUS IS DEVELOPING FROM
ORLANDO NORTHWARD.
TONIGHT...GFS HAS SFC LOW DEEPENING TO 1005 MBS TONIGHT OFF THE NE
FL COAST WITH SOME CONVERGENT BAND SHOWERS LIKELY AFFECTING VOLUSIA
COUNTY INTO THE EVENING WITH ISOLATED SHOWERS OVERNIGHT. FATHER
SOUTH...EXPECT SCATTERED EVENING CONVECTION ACROSS THE TREASURE
COAST TO WANE BY LATE EVENING WITH ACTIVITY PUSHING OFFSHORE INTO
THE ATLC OVERNIGHT. LOWS MAINLY IN THE MID 70S.
SAT...500MB TROUGH OFF THE SOUTHEAST U.S. COAST AND EXTENDING ACROSS
FL WILL AID IN INTENSIFYING THE SFC LOW EAST OF GA/SC COAST. MODELS
SHOW DEEPER MOISTURE SHIFTING EAST WITH THIS SYSTEM. HOWEVER THERE
WILL STILL BE SUFFICIENT LOW LEVEL MOISTURE AVAILABLE FOR SCATTERED
SHOWERS AND ISOLATED STORMS INTO THE AFT...ESPECIALLY WITH
ADDITIONAL SUPPORT FOR LIFT FROM TRAILING FRONTAL BOUNDARY CROSSING
THE REGION AND PROXIMITY OF MID LEVEL TROUGH. HAVE POPS AROUND 40
PERCENT OVER THE AREA. HIGHS WILL RANGE FROM THE UPPER 80S TO AROUND
90 DEG.
SUN-MON...LOW OFF THE SOUTHEAST U.S. COAST WILL MOVE SLOWLY EASTWARD
AS 500MB TROUGH AXIS MOVES INTO S FL. GFS SHOWS MUCH DRIER AIR
MOVING SOUTHWARD INTO THE AREA ON THE BACK SIDE OF THE LOW WITH PW
VALUES AS LOW AS 0.9-1.0 INCH. HOWEVER NAM NOT QUITE AS DRY...SO
TRENDED LOWER WITH POPS BUT NOT AS EXTREME AS THE MAV/MEX GUIDANCE
FOR NOW. REGARDLESS LOW RAIN CHANCES EXPECTED LATE WEEKEND INTO
EARLY NEXT WEEK WITH FORECAST POPS AOB 30 PERCENT. HIGHS IN THE
UPPER 80S TO LOW 90S EXPECTED.
TUE-THU...THE GFS AND ECMWF ARE IN BETTER AGREEMENT SHOWING ANOTHER
MID LEVEL TROUGH DIGGING SOUTHWARD ACROSS THE EASTERN CONUS INTO TUE
AND EVENTUALLY CUTTING OFF ACROSS THE SOUTHEAST STATES. LOW LEVEL
FLOW BECOMES MORE ONSHORE INTO MID WEEK AS LOW OFF THE EAST COAST
EITHER WEAKENS OR LIFTS NORTHEAST...DEPENDING ON WHICH MODEL IS TO
BE BELIEVED. MOISTURE GRADUALLY INCREASES BACK ACROSS THE REGION IN
THIS ONSHORE FLOW AND PROXIMITY OF CUTOFF LOW ALOFT WILL KEEP WX
PATTER UNSETTLED FOR AT LEAST CHANCE POPS THROUGH THE REST OF THE
WORK WEEK. ONSHORE WINDS AND INCREASING SHOWER/STORM COVERAGE WILL
KEEP HIGHS NEAR TO SLIGHTLY BELOW NORMAL IN THE MID/UPPER 80S.
&&
.AVIATION...IFR-MVFR STRATUS WILL AFFECT TERMINALS UNTIL AROUND
13Z...WITH LIFR CIGS/VSBYS AT KVRB-KFPR. EXPECT STRATUS TO SLOWLY
LIFT THROUGH 15Z THOUGH SOME MVFR CIGS WILL LIKELY LINGER. SCATTERED-
NMRS SHRA/TSRA MAINLY FROM KVRB-KSUA IN THE AFTERNOON AND ALSO
HIGHER CONVECTIVE COVERAGE AROUND KDAB VCNTY LATER INTO THE
AFTERNOON WITH SOME ACTIVITY MOVING IN FROM THE NORTH ON THE BACK
SIDE OF THE SFC LOW DEVELOPING OFFSHORE. SHOULD ALSO SEE CONVECTION
DEVELOP BTWN 18Z-21Z IN THE VCNTY OF ORLANDO AREA TERMINALS.
&&
.MARINE...NW WINDS TO 5-10 KNOTS ACROSS NRN SECTIONS WITH SW FLOW S
OF THE TROUGH AXIS ACROSS THE SRN WATERS. SEAS MAINLY 3-4 FT. SFC
LOW WILL DEEPEN OFFSHORE OF NE FL TONIGHT WITH SOME HIGHER SEAS
MAKING IT INTO THE VOLUSIA COUNTY WATERS TO 4-5 FT ON THE BACK SIDE
OF THE LOW WITH WINDS INCREASING TO 10-15 KNOTS.
SAT-TUE...LOW PRESSURE OFF THE SOUTHEAST U.S. COAST SHIFTS SLOWLY
EASTWARD INTO LATE WEEKEND/EARLY NEXT WEEK. TRAILING WEAK FRONTAL
TROUGH CROSSING THE REGION SAT WILL SHIFT WESTERLY WINDS TO A MORE
NORTHERLY DIRECTION WITH SPEEDS UP TO 10-15 KNOTS. SEAS ARE EXPECTED
TO BUILD TO UP TO 4-5 FEET IN THE NORTHERLY FLOW. NORTH WINDS THEN
DECREASE TO 5-10 KNOTS SUN WITH SEAS RANGING FROM 2-4 FEET.
WINDS BECOME MORE ONSHORE INTO EARLY NEXT WEEK WITH WIND SPEEDS
REMAINING RELATIVELY LIGHT AROUND 5-10 KNOTS. SEAS SHOULD CONTINUE
TO DECREASE WITH FORECAST WAVE HEIGHTS 2-3 FEET.
&&
.HYDROLOGY...AS A RESULT OF THE RECENT HEAVY RAINS...THE SAINT JOHNS
RIVER ABOVE LAKE HARNEY /GENF1/ HAS REACHED 6.0FT...WHICH IS LESS
THAN A FOOT BELOW ACTION STAGE (6.5FT). THE RIVER IS FORECAST TO
REACH THE LOWER THRESHOLD OF ACTION STAGE (6.6FT) THERE LATE
SATURDAY NIGHT OR EARLY SUNDAY MORNING...AND REMAIN THERE THROUGH
EARLY NEXT WEEK.
THE SAINT JOHNS RIVER AT ASTOR /ASTF1/ HAS REACHED 2.1FT...WHICH IS
.4 FEET BELOW ACTIONS STAGE (2.5FT). THE RIVER IS FORECAST TO REMAIN
BELOW ACTIONS STAGE...GRADUALLY CRESTING NEAR 2.2 TO 2.3FT THIS
WEEKEND...AND REMAINING STEADY STATE THROUGH EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 86 72 87 70 / 70 50 40 10
MCO 85 72 89 72 / 60 30 40 10
MLB 85 72 90 74 / 70 30 40 20
VRB 85 72 89 71 / 70 40 40 20
LEE 86 72 88 72 / 60 30 40 10
SFB 86 73 88 72 / 60 30 40 10
ORL 86 73 88 74 / 60 30 40 10
FPR 86 73 89 72 / 80 40 40 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...FLOOD WATCH THROUGH THIS EVENING FOR COASTAL VOLUSIA COUNTY-
INDIAN RIVER-MARTIN-NORTHERN BREVARD COUNTY-SOUTHERN
BREVARD COUNTY-ST. LUCIE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...VOLKMER
LONG TERM....WEITLICH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
257 AM MDT FRI SEP 18 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 244 AM MDT FRI SEP 18 2015
SCATTERED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS WILL CONTINUE
THROUGH THE LATE MORNING/EARLY AFTERNOON AHEAD OF A SHORTWAVE
TROUGH MOVING OUT OF THE NORTHERN HIGH PLAINS. BEST CHANCES WILL
BE IN NEBRASKA. STORMS HAVE STRUGGLED SO FAR BUT HRRR SHOWS
REDEVELOPMENT FURTHER SOUTH BY 12Z SO WILL CONTINUE TO CARRY
SLIGHT TO MID RANGE POPS. MUCAPE GENERALLY LESS THAN 500 J/KG SO
CANNOT RULE OUT AN ISOLATED STRONGER STORM CAPABLE OF PRODUCING
SMALL HAIL. ACTIVITY WILL MOVE EAST BY EARLY AFTERNOON...BUT
STRATUS MAY LINGER UNTIL THEN PARTICULARLY IN EASTERN AREAS
LEADING TO A LOW CONFIDENCE AFTERNOON TEMPERATURE FORECAST.
SIMILARLY...LOW TEMPERATURES TONIGHT COMPLICATED BY REDEVELOPMENT
OF STRATUS AND PATCHY FOG...BUT WITH LIGHT WINDS MAY BE ABLE TO
DROP TO LOWER TO MIDDLE 40S BEFORE SATURATION OCCURS. CLOUDS BURN
OFF AGAIN BY SATURDAY AFTERNOON WITH TEMPERATURES WARMING INTO THE
MIDDLE 70S. MODELS HAVE BACKED OFF ELEVATED THUNDERSTORM POTENTIAL
FOR SATURDAY NIGHT AS IT LOOKS LIKE THE UPPER SHORTWAVE WILL BE
WEAKER AND FURTHER NORTH...SO REDUCED POPS TO SLIGHT CHANCE FOR
THE OVERNIGHT HOURS. SHORTWAVE RIDGING BUILDS IN BEHIND IT FOR
SUNDAY WITH TEMPERATURES REBOUNDING TO THE LOWER 80S UNDER MOSTLY
SUNNY SKIES.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 244 AM MDT FRI SEP 18 2015
A DRY START TO THE WORK WEEK IS EXPECTED AS UPPER LEVEL RIDGING
BUILDS OVER THE AREA FROM THE DESERT SOUTHWEST AND A LEE TROUGH
REDEVELOPS EAST OF THE ROCKIES. THIS SETUP WILL BRING DRIER
CONDITIONS TO THE HIGH PLAINS THROUGH TUESDAY NIGHT.
THE NEXT CHANCE FOR PRECIPITATION PRESENTS ITSELF WEDNESDAY THROUGH
THURSDAY. A SHORTWAVE TROUGH MOVES ONTO THE CALIFORNIA COAST TUESDAY
NIGHT AND TRAVELS OVER THE DESERT SOUTHWEST TOWARDS THE REGION. THE
TROUGH APPEARS TO WEAKEN BUT IT LOOKS LIKE MULTIPLE DISTURBANCES
WILL MOVE THROUGH THE UPPER LEVEL FLOW MIDWEEK GENERATING SHOWER AND
THUNDERSTORM CHANCES FOR THE AREA.
RELATIVELY CONSISTENT TEMPERATURES ARE EXPECTED IN THE EXTENDED
PERIOD WITH HIGHS IN THE MID 80S TO NEAR 90S DEGREES AND LOWS IN THE
MID 50S TO LOW 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1136 PM MDT THU SEP 17 2015
CONFIDENCE HAS GROWN IN WIDESPREAD STRATUS THIS MORNING. LATEST
TRENDS IN RUC...NAM AND SREF GUIDANCE INDICATE AT LEAST MVFR
CONDITIONS. LOCAL CLIMATOLOGY SUGGESTS THIS PATTERN IS FAVORABLE
FOR IFR CONDITIONS. THEREFORE...FORECAST IFR CEILINGS. IN
ADDITION...ADDED VCTS AT KMCK AS TRENDS INDICATE ELEVATED STORM
DEVELOPMENT IS POSSIBLE. IN FACT...ACCUS MAY BE DEVELOPING ACROSS
SOUTHWEST NEBRASKA AS OF RECENT SATELLITE IMAGERY. ALL STORMS
SHOULD EXIT THE REGION BY MID-MORNING. STRATUS WILL BE SLOWER TO
LEAVE WITH THE FRONT TO THE SOUTH AND COLD AIR ADVECTION EXPECTED.
MOISTURE SUPPLY IS AMPLE AS LOW LEVEL JET FEEDS MOISTURE INTO THE
REGION. THEREFORE...STRATUS SLOWLY BURNS OFF FROM SOUTHWEST TO
NORTHEAST. STRATUS MAY PERSIST WELL INTO THE AFTERNOON AT KMCK SO
EXTENDED PREVAILING STRATUS/POOR CONDITIONS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...024
LONG TERM...JBH
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
335 AM CDT FRI SEP 18 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 335 AM CDT FRI SEP 18 2015
THE PRIMARY FORECAST CONCERNS ARE PCPN CHANCES/COVERAGE TODAY INTO
THIS EVENING...POTENTIAL FOR LOW CLOUDS AND OR PATCHY FOG TONIGHT
AND TEMPERATURES THE NEXT FEW DAYS.
MAIN FEATURES FROM UPPER LEVEL CHARTS LAST EVENING INCLUDED THE
FOLLOWING. A JET MAX OF 80-90 KNOTS AT 300 MB WAS OVER WY AND CO
LIFTING NORTHEAST. BEST 12 HOUR HEIGHT FALLS AT 500 MB WERE OVER
THE NRN PLAINS AND LIFTING INTO CANADA...BUT THE MAIN TROUGH AXIS
WAS STILL BACK OVER THE ROCKIES. THERMAL RIDGE AT 700 MB HAD
FLATTENED A BIT...AND EXTENDED FROM SRN NM INTO CNTRL MO. 850 MB
SHOWED HIGH PRES OVER THE DKTS AND N WINDS OVER THE CNTRL PLAINS
WITH CDFNT CURVING FROM WRN WI INTO NERN KS THEN BACK INTO ERN CO.
SFC ANLYS AT 08Z SHOWED TEMPERATURES IN THE 50S ACROSS OUR NRN
ZONES AND UPPER 60S/LOWER 70S NEAR THE KS AND MO BORDERS.
SHORT RANGE MODELS ARE IN FAIRLY GOOD AGREEMENT SHOWING PCPN
COVERAGE INCREASING THIS MORNING. PCPN CHANCES ARE HIGHEST ACROSS
OUR ERN AND SRN COUNTIES INTO MID AFTN. WILL MENTION AT LEAST
ISOLD TSTMS EVEN INTO PARTS OF NERN NE WITH ELEVATED INSTABILITY
MUCH OF THE DAY. USED SPC SREF MU CAPE OF 500 J/KG OR MORE AND
FCST SOUNDINGS TO HELP DETERMINE AREA WITH THUNDER POTENTIAL.
RECENT EXPERIMENTAL HRRR RUNS SEEM REASONABLE WITH PCPN COVERAGE
AND TIMING. WILL STAY FAIRLY CLOSE TO MOS GUIDANCE FOR HIGHS
TODAY...GENERALLY MID OR UPPER 60S...BUT SOME LOWER 70S PSBL IN
THE S. MAIN AREA OF SHOWERS WILL BE MOVING EAST OUT OF OUR AREA
EARLY THIS EVENING...BUT AN AREA OF LIGHT PCPN COULD MOVE OUT OF
CNTRL NE/CNTRL SD INTO PARTS OF NERN NE BEFORE ENDING EARLY THIS
EVENING. QUESTION THEN BECOMES...HOW MUCH CLEARING WILL OCCUR.
PRESSURE GRADIENT REMAINS MODEST...SO FOG POTENTIAL DOES NOT
APPEAR OVERLY HIGH. BUT...WE MAY SEE SOME STRATUS. NAM IS THE
MOST AGGRESSIVE WITH LOW CLOUDS TONIGHT. KEPT SOME CLOUDS IN...
BUT DID NOT COMPLETELY BUY INTO THE NAM OUTPUT AT THIS POINT.
SATURDAY THROUGH SUNDAY SHOULD BE DRY...WITH HIGHS SATURDAY MAINLY
IN THE UPPER 60S AND HIGHS SUNDAY IN THE 70S.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 335 AM CDT FRI SEP 18 2015
TEMPERATURES SHOULD SLOWLY MODERATE THROUGH MID WEEK...THEN DROP
OFF A BIT TOWARD THURSDAY/FRIDAY. A MID LEVEL RIDGE WILL BUILD
EAST FROM THE ROCKIES...THEN EXTEND FROM MEXICO TOWARD THE GREAT
LAKES REGION BY THURSDAY. THERE WILL BE SOME LOW CHANCES FOR
SHOWERS AND THUNDERSTORMS...MAINLY FROM MONDAY NIGHT INTO TUESDAY
THEN WEDNESDAY NIGHT INTO THURSDAY NIGHT.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1130 PM CDT THU SEP 17 2015
MVFR CIGS AND VSBYS EXPECTED TO DEVELOP AFTER 12Z WITH PERSISTENT
RAIN OR SHOWERS KOMA AND KLNK AND CONTINUE THROUGH 00Z BEFORE
IMPROVING TO VFR AS SFC LOW MOVES NORTHEAST ALONG FRONTAL BOUNDARY
OVER KANSAS AND NORTHERN MISSOURI. KOFK EXPECTED TO SEE MAINLY VFR
CONDITIONS WITH PERIODS OF LIGHT RAIN OR SHOWERS AFTER 15Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1131 PM CDT THU SEP 17 2015
.SHORT TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 306 PM CDT THU SEP 17 2015
COLD FRONT IS PROGRESSING THROUGH THE MID-MISSOURI VALLEY REGION
TODAY. SUBJECTIVE 12Z UPPER AIR ANALYSIS INDICATES BROAD
SOUTHWESTERLY FLOW ACROSS THE WESTERN AND CENTRAL US...WITH TROUGH
AXIS FROM OR THROUGH NV/CA...AND WITH NORTHERN STREAM TROUGH NEAR
THE AB/SASK BORDER TO MT. 500MB HEIGHT FALLS UP TO 50M WERE NOTED
IN THE NORTH CENTRAL US. 850MB COLD FRONT EXTENDED FROM THE ONT/MB
BORDER THROUGH THE ND/MN AND SD/MN BORDER...INTO CENTRAL TO
SOUTHWEST NEB. AHEAD OF THE FRONT...AIRMASS WAS MOISTURE
RICH...WITH DEWPOINTS OF 12C+ FROM THE MO VALLEY TO THE WESTERN
GREAT LAKES...AND WITH 40-50KT WEST-SOUTHWESTERLY WINDS. 700-500MB
TEMPERATURE DIFFERENCE WAS MAXIMIZED OVER NEB...AT THE NOSE OF THE
700MB THERMAL RIDGE. SURFACE COLD FRONT AT 19Z EXTENDED FROM
SURFACE LOW IN WESTERN ONT...THROUGH CENTRAL MM...TO NEAR KDNS...TO
KOMA...TO SECONDARY SURFACE LOW IN NORTH CENTRAL KS. ALONG AND
AHEAD OF THE FRONT...CU FIELD HAD DEVELOPED...WITH DEWPOINTS IN THE
UPPER 60S TO LOWER 70S. BEHIND IT...DEWPOINTS WERE IN THE 50S WITH
QUICKLY CLEARING SKIES.
MAIN FORECAST CONCERN IS CONVECTIVE DEVELOPMENT THIS
AFTERNOON/EVENING...AND RAIN CHANCES TOMORROW. FRONT CONTINUES TO
ADVANCE THROUGH THE CWA. AHEAD OF IT...CONVECTIVE DEVELOPMENT IS
POSSIBLE THIS AFTERNOON...THOUGH NOT YET IMMINENT AS CU FIELD IS
VISUALLY SHALLOW WITH NO ECHOES YET ON RADAR. RAP ANALYSIS
INDICATES ABOUT 3000 J/KG UNCAPPED MLCAPE AHEAD OF THE FRONT...BUT
MOST OF THE BULK SHEAR IS BEHIND THE FRONT. WITH THAT
INSTABILITY...ANY STORMS THAT POP UP COULD BECOME BRIEFLY
SEVERE...BUT THINK THEY MAY BE ON THE PULSY SIDE GIVEN THE
MISALIGNED DEEP-LAYER SHEAR. FRONT IS MAKING FAIRLY RAPID
PROGRESS...AND HAVE SPED THE EXIT OF STORMS IN THE SOUTH AND LOWERED
POPS IN ALL BUT THE SOUTHERNMOST/SOUTHEASTERNMOST FRINGE OF THE CWA
FOR THIS EVENING.
FROM EARLY FRIDAY MORNING THROUGH THE AFTERNOON...UPPER-LEVEL TROUGH
ADVANCES THROUGH THE NORTHERN ROCKIES AND TOWARD THE PLAINS...WITH
LEE SURFACE LOW DEEPENING AND SLIDING ACROSS THE FRONTAL BOUNDARY
THROUGH KS AND INTO NORTHERN MO/SOUTHERN IA. MOST OF THE CWA WILL
BE WELL NORTH OF THE LOW...AND AS BAROCLINIC ZONE ON THE NORTHERN
SIDE DEVELOPS AND RAIN DEVELOPS/EXPANDS...THINK WE MAINLY WILL SEE
JUST DREARY RAIN AND PERHAPS A LITTLE EMBEDDED THUNDER...WITH A
COUPLE OF THUNDERSTORMS POSSIBLE IN THE FAR SOUTHERN CWA IF
ANYWHERE. RAIN SHOULD SHIFT EAST/SOUTHEAST OF THE CWA THROUGH THE
AFTERNOON...WITH MOST OF THE AREA RAIN-FREE BY AROUND 00Z.
HIGH PRESSURE WILL FOLLOW ON THE HEELS OF THE SYSTEM AND INFLUENCE
THE AREA THROUGH SATURDAY...WITH QUIET AND COOLER WEATHER FRIDAY AND
SATURDAY BEFORE TEMPERATURES MODERATE TOWARD NORMAL ON SUNDAY.
RETURN FLOW ON SATURDAY NIGHT MAY SPARK A FEW SHOWERS/STORMS IN
CENTRAL/WESTERN NEB ON SATURDAY NIGHT INTO SUNDAY MORNING...BUT
THINK THIS ACTIVITY WILL STAY WEST OF THE CWA.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 306 PM CDT THU SEP 17 2015
RETURN FLOW CONTINUES INTO THE PLAINS INTO THE WORK WEEK...WITH AN
UPPER-LEVEL RIDGE BUILDING INTO THE PLAINS THROUGH TUESDAY AND
BRINGING MODERATING TEMPERATURES...BEFORE GIVING WAY TO
SOUTHWESTERLY FLOW AS IT FLATTENS. AROUND WEDNESDAY/WEDNESDAY
NIGHT...THE NEXT UPPER-LEVEL TROUGH TO PUSH ACROSS THE PLAINS WILL
BRING A COLD FRONT AND ASSOCIATED SHOWER/THUNDERSTORM CHANCES. FRONT
DOES NOT APPEAR TO HAVE A STRONG COLD PUSH THOUGH...AND NEAR TO
ABOVE AVERAGE TEMPERATURES SHOULD CONTINUE THROUGH THURSDAY.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1130 PM CDT THU SEP 17 2015
MVFR CIGS AND VSBYS EXPECTED TO DEVELOP AFTER 12Z WITH PERSISTENT
RAIN OR SHOWERS KOMA AND KLNK AND CONTINUE THROUGH 00Z BEFORE
IMPROVING TO VFR AS SFC LOW MOVES NORTHEAST ALONG FRONTAL BOUNDARY
OVER KANSAS AND NORTHERN MISSOURI. KOFK EXPECTED TO SEE MAINLY VFR
CONDITIONS WITH PERIODS OF LIGHT RAIN OR SHOWERS AFTER 15Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MAYES
LONG TERM...MAYES
AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1212 AM CDT FRI SEP 18 2015
.UPDATE...
ISSUED AT 1212 AM CDT FRI SEP 18 2015
LATEST SUITE OF SATELLITE IMAGERY SHOWS A SHORTWAVE TROUGH NOW INTO
WESTERN WYOMING WITH SURFACE LOW PRESSURE JUST SOUTH OF GILLETTE.
MID LEVEL CLOUDS/BKN TO OVC NOW ENTERING BEACH AND APPROACHING
DICKINSON. REGIONAL RADAR SHOWS INCREASING REFLECTIVITY`S OVER
BOWMAN AND SLOPE COUNTIES. MILES CITY MONTANA REPORTED A TRACE OF
RAIN LAST COUPLE OF HOURS AND BAKER MONTANA IS NOW REPORTING LIGHT
RAIN. THE LATEST HRRR AND GFS SEEM TO HAVE THE BEST INITIALIZATION
ON THE CURRENT SITUATION. WITH THAT SAID THE PREVIOUS FORECAST IS
ON TRACK WITH SHOWERS EXPANDING SOUTHWEST INTO SOUTH CENTRAL
OVERNIGHT THROUGH FRIDAY MORNING. HIGHEST POPS NEAR/ALONG THE
SOUTHERN BORDER INTO FRIDAY AFTERNOON BEFORE TAPERING OFF FROM
WEST TO EAST. THE FROST ADVISORY ALSO REMAINS IN GOOD STANDING
WITH DEWPOINTS IN THE UPPER 30S. EXPECTING SCATTERED HIGH CLOUDS
SCOOTING ACROSS THE NORTHWEST AND NORTH CENTRAL AT TIMES FOR THE
REST OF THE OVERNIGHT PERIOD. OVERALL NO SIGNIFICANT CHANGES TO
PREVIOUS FORECAST.
UPDATE ISSUED AT 945 PM CDT THU SEP 17 2015
EXTENDED THE FROST ADVISORY INTO WELLS AND FOSTER COUNTIES WITH
THIS UPDATE AS LOWS IN THE MID 30S ARE NOW EXPECTED GIVEN LIGHT
WINDS AND CLEAR SKIES THE REMAINDER OF THE NIGHT.
UPDATE ISSUED AT 641 PM CDT THU SEP 17 2015
NO CHANGES TO THE FROST ADVISORY NEEDED AT THIS
TIME. INCREASING CLOUD COVER AND SHOWER ACTIVITY ACROSS THE
SOUTHWEST AND SOUTH CENTRAL TONIGHT IN ASSOCIATION WITH
CYCLOGENESIS ACROSS WESTERN SOUTH DAKOTA IS EXPECTED TO HOLD
OVERNIGHT LOWS IN THE 40S FOR THESE AREAS. THUS...AN EXPANSION OF
THE FROST ADVISORY FURTHER SOUTH APPEARS TO BE UNLIKELY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 236 PM CDT THU SEP 17 2015
PATCHY FROST TONIGHT AND SHOWERS FRIDAY HIGHLIGHT THE SHORT TERM
PERIOD.
CURRENTLY...SURFACE HIGH PRESSURE WAS SITUATED OVER SOUTHEAST
MONTANA WITH LOW PRESSURE FROM ONTARIO INTO THE CENTRAL PLAINS.
WRAP AROUND MOISTURE WAS PRODUCING A BROKEN STRATOCUMULUS DECK
ACROSS MUCH OF THE NORTH CENTRAL INTO EASTERN NORTH DAKOTA WITH A
FEW SPRINKLES OR SHOWERS IN THE FAR NORTH CENTRAL AND NORTHEAST.
FARTHER SOUTH AND WEST...SKIES HAD CLEARED WITH SUNNY CONDITIONS
OVER SOUTHWEST NORTH DAKOTA. IT WAS BREEZY ACROSS WESTERN AND
CENTRAL NORTH DAKOTA WITH WINDS GENERALLY 15 TO 25 MPH.
LATE THIS AFTERNOON...CONTINUED CLEARING FROM WEST TO EAST...A
STRAY SHOWER IS STILL POSSIBLE IN THE TURTLE MOUNTAINS AREA. WINDS
WILL DIMINISH WEST LATE THIS AFTERNOON.
TONIGHT AND FRIDAY...SURFACE HIGH PRESSURE WILL BUILD OVER THE
STATE TONIGHT AND IS FORECAST TO BE SITUATED NORTHWEST TO
SOUTHEAST ACROSS THE FORECAST AREA BY 12 UTC FRIDAY. AN UPPER
LEVEL SHORTWAVE WILL TRACK ACROSS THE NORTHERN ROCKIES TONIGHT AND
INTO THE HIGH PLAINS OF EASTERN WYOMING BY FRIDAY MORNING. THIS
WILL BRING INCREASING CLOUDS FROM WEST TO EAST ACROSS THE SOUTHERN
HALF OF THE FORECAST AREA. WITH SCATTERED SHOWERS ALSO SPREADING
WEST TO EAST FROM SOUTHWEST INTO SOUTH CENTRAL NORTH DAKOTA AFTER
MIDNIGHT.
WITH COLD HIGH PRESSURE SITUATED OVER THE AREA...EXPECT LIGHT
WINDS OVERNIGHT AND CLEAR SKIES THIS EVENING. AND INCREASING
CLOUDS SOUTH AFTER MIDNIGHT. GOOD RADIATIONAL COOLING EXPECTED TO
LAST THROUGH THE NIGHT IN THE NORTH...THEREFORE THEY WILL BE MOST
LIKELY TO FALL INTO THE MIDDLE 30S AND EXPERIENCE SOME FROST. WITH
INCREASING CLOUDS EXPECTED OVER THE SOUTH...THINK WE WILL REMAIN
IN THE UPPER 30S TO MID 40S. WILL ISSUE A FROST ADVISORY ACROSS
THE NORTHERN TIER COUNTIES AND PORTIONS OF THE CENTRAL ALONG LAKE
SAKAKAWEA.
EXPECT SHOWERS TO SKIRT ACROSS THE SOUTHERN TIER COUNTIES THROUGH
THE DAY ON FRIDAY...MAINLY SOUTH OF THE I94 CORRIDOR...WITH
PARTLY TO MOSTLY SUNNY CONDITIONS NORTH. THEREFORE ALTHOUGH THE
NORTH WILL START OFF COOLER...DUE TO THE INCREASED CLOUDS AND
SHOWERS SOUTH...THE NORTH WILL ALSO BE THE WARMEST ON FRIDAY WITH
LOWER 70S...COMPARED TO LOWER TO MIDDLE 60S SOUTH.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 236 PM CDT THU SEP 17 2015
FRIDAY NIGHT THROUGH SUNDAY: UPPER LEVEL SHORTWAVE RIDGING FRIDAY
NIGHT AHEAD OF AN UPPER LEVEL SHORTWAVE TROUGH THAT IS PROGGED TO
MOVE INTO WESTERN NORTH DAKOTA SATURDAY MORNING...AND MOVE EAST
ACROSS THE STATE THROUGH SATURDAY NIGHT. DRY LOWER ATMOSPHERE BOTH
AHEAD AND BEHIND THE ATTENDANT SURFACE TROUGH THAT SEPARATES TWO DRY
AND MILD PACIFIC HIGH PRESSURE AIRMASSES WILL RESULT IN MORE STABLE
CONDITIONS...ESPECIALLY WITH THE LACK OF MID-LEVEL MOISTURE AS WELL.
SHOULD RESULT IN DRY CONDITIONS WITH SEASONABLE TO SLIGHTLY ABOVE
AVERAGE TEMPERATURES WITH LOWS MAINLY IN THE 40S AND HIGHS IN THE
70S.
MONDAY THROUGH THURSDAY: ZONAL UPPER LEVEL FLOW MONDAY AND TUESDAY
SHOULD KEEP THE FORECAST MAINLY DRY. MONDAY AFTERNOON/NIGHT A COLD
FRONT DROPS SOUTH ACROSS THE STATE. HIGHS MONDAY IN THE 70S TO LOWER
80S...COOLING TO THE UPPER 60S NORTH AND TO THE 70S SOUTH TUESDAY
THROUGH THURSDAY...BUT STILL SEASONABLE FOR LATE SUMMER INTO EARLY
FALL. A DISTURBANCE MOVING NORTHEASTWARD OUT OF THE 4-CORNERS AND US
SOUTHWEST REACHES THE NORTHERN PLAINS BY WEDNESDAY. THIS SYSTEM WILL
BRING MORE LOW AND MID-LEVEL MOISTURE WITH IT AND BRING CHANCES OF
SHOWERS AND POSSIBLE THUNDERSHOWERS WEDNESDAY AND THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1212 AM CDT FRI SEP 18 2015
LIGHT RAINSHOWERS EXPECTED AT KDIK BY 08Z FRIDAY AND AT KBIS BY
12Z FRIDAY. KBIS/KJMS WILL REMAIN ON THE FAR NORTHERN FRINGE OF
THE PRECIPITATION AREA...AND ENOUGH UNCERTAINTY EXISTS AT KJMS
AT THIS TIME...THUS AND HAVE GONE WITH A VCSH AT KJMS BY 14Z
FRIDAY. VFR CIGS EXPECTED AT ALL TERMINALS...WITH CIGS OF 5000FT
AT KDIK/KBIS ASSOCIATED WITH THE RAINSHOWERS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 3 AM TO 9 AM CDT FRIDAY FOR NDZ001>005-
009>013-017>023-025.
&&
$$
UPDATE...KS
SHORT TERM...TWH
LONG TERM...JV
AVIATION...KS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
149 AM EDT FRI SEP 18 2015
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE ALONG THE EAST COAST WILL WEAKEN AND
MOVE EAST THIS WEEKEND. THIS WILL ALLOW A COLD FRONT TO MOVE
THROUGH SATURDAY AFTERNOON AND EVENING. HIGH PRESSURE WILL BUILD
EAST ACROSS THE GREAT LAKES AND LOWER OHIO VALLEY SATURDAY NIGHT AND
LINGER THROUGH EARLY MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
HAVE TRIED TO FINE TUNE THE FORECAST. CLOUDS FROM THE CONVECTION
OVER NRN IL AND SRN WI ARE JUST ABOUT TO NW OHIO. THESE CLOUDS
WILL OVERSPREAD THE WEST HALF OF THE AREA OVERNIGHT SO HAVE
BUMPED UP TEMPS IN NW OH A FEW DEGREES. LATEST HRRR CONTINUES TO
SHOW SOME OF THE PRECIP MAKING IT TO THE LOCAL AREA LATE TONIGHT
AND FRIDAY MORNING SO SEE NO NEED TO CHANGE PRECIP CHANCES.
ORIGINAL...MOSTLY CLEAR SKIES ACROSS THE AREA THIS AFTERNOON WILL
CONTINUE THROUGH THE EVENING AND INTO THE OVERNIGHT BEFORE CLOUDS
BEGIN TO INCREASE IN THE WEST. BY MORNING THE GFS AND NAM AGREE ON
A SIGNIFICANT AMOUNT OF MOISTURE GETTING INTO THE WESTERN
COUNTIES. NO PLANNING ON ANY CONVECTION AT 12Z BUT WILL HAVE A
SLIGHT CHANCE POP IN THE GRIDS BY MORNING. CLOUDS SHOULD MOVE IN
AFTER MIDNIGHT. EAST OF A MNN-LPR LINE WILL KEEP SKIES PC. LOWS
SIMILAR TO LAST NIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
THE SHORT TERM BEGINS WITH DEEP MOISTURE MOVING INTO THE WESTERN
COUNTIES WHILE TO THE EAST HIGH PRESSURE AND DRY AIR WILL STILL BE
HOLDING ON. MODELS BRING THE MOISTURE EAST ACROSS THE AREA DURING
THE DAY FINALLY REACHING NWRN PA BY 21-00Z TIME FRAME. AM
EXPECTING SHOWERS TO MOVE EAST ACROSS THE AREA DURING THE DAY
ALTHOUGH AS THEY MOVES EAST EXPECTING SHOWERS TO THIN AS THEY RUN
INTO DRIER AIR. STILL...WILL HAVE CHANCE POPS FOR THE DAY FOR MOST
LOCATIONS. FRIDAY NIGHT A WAVE DEVELOPS ON THE FRONT AND MOVES
NORTHEAST INTO THE CENTRAL LAKES ON SATURDAY. WEAK WARM ADVECTION
DEVELOPS FRIDAY NIGHT ACROSS THE AREA AHEAD OF THE DEVELOPING LOW
AND WILL LIKELY BE THE FOCUS FOR A CONTINUED THREAT OF SHOWERS.
MODELS IN DECENT AGREEMENT WITH THE COLD FRONT TIMING SATURDAY
WITH PASSAGE BEGINNING IN THE WEST ABOUT NOON AND EXITING THE AREA
EAST ABOUT 6PM. WILL CONTINUE WITH LIKELY POPS ACROSS THE AREA.
DRY AIR AND HIGH PRESSURE BUILD IN QUICKLY IN ITS WAKE SATURDAY.
WILL HAVE LIKELY POPS TO START FAR EAST SATURDAY NIGHT BUT WILL
DRY OUT THE FORECAST FOR THE OVERNIGHT. TEMPS ABOVE NORMAL FRIDAY
DROPPING TO BELOW NORMAL BY SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
MODELS ARE SUGGESTING AN UPPER LEVEL LOW BECOMING CUT OFF ACROSS THE
SERN US. THIS TROUGH WILL BE ACCOMPANIED BY A SHARP INVERTED TROUGH
AT THE SURFACE WHICH WILL DEVELOP NEAR THE OH PA BOARDER. THE LATEST
GFS AND ECMWF RUNS CONTINUE TO PRINT OUT LIGHT QPF ACROSS WESTERN PA
INTO EASTERN OH. DESPITE SUFFICIENT FORCING...MOISTURE WILL BE
SOMEWHAT LIMITED WITH HIGH PRESSURE BULGING IN FROM THE NORTH. KEPT
THE SLIGHT CHANCE 20 POPS GOING FROM CLEVELAND EAST ON TUESDAY...BUT
WOULDNT BE SURPRISED IF LATER FORECASTS CONTINUE TO DIAL BACK POPS.
IN OTHER WORDS...MOST OF MON AND TUE WILL BE DRY WITH PERHAPS A
SHOWER OR TWO IN THE FAR EAST. TEMPERATURES WILL BE VERY CLOSE TO
NORMAL.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THE LOW LEVEL JET AND
WARM ADVECTION OUT AHEAD OF THE MISSISSIPPI VALLEY TROUGH WILL
TAKE A RUN EASTWARD TODAY...LIKELY REACHING KTOL THIS MORNING.
NOT AS MUCH CONFIDENCE AT THE TAF SITES FARTHER EAST...MENTIONED
"VICINITY" AT KFDY AND DID NOT INCLUDE AND SHOWERS FARTHER EAST
ALTHOUGH THERE IS CERTAINLY A CHANCE FOR A BRIEF SHOWER OR
SPRINKLE ESPECIALLY AT KCLE AND KERI LATER. EVEN IF IT RAINS AT
THOSE SITES...CONDITIONS WILL LIKELY REMAIN VFR. SHOWERS AND
THUNDERSTORMS WILL REDEVELOP TONIGHT BUT LIKELY STAY MAINLY NORTH
AND WEST OF THE AREA. MENTIONED VICINITY THUNDER AT KTOL AND KCLE
FRIDAY NIGHT.
OUTLOOK...NON-VFR POSSIBLE WITH SHOWERS AND THUNDERSTORMS FRIDAY
NIGHT AND SATURDAY WITH THE PASSAGE OF A COLD FRONT. NON-VFR
CEILINGS MAY LINGER INTO SUNDAY MORNING NEAR LAKE ERIE. VFR FROM
SUNDAY AFTERNOON ON.
&&
.MARINE...
HIGH PRESSURE IS GRADUALLY MOVING OFF TO THE EAST. A WEAK
FRONT/SURFACE TROUGH WILL CROSS THE WESTERN END OF THE LAKE FRIDAY
MORNING THEN WEAKEN. A SECONDARY COLD FRONT WILL CROSS THE LAKE
DURING THE DAYLIGHT HOURS ON SATURDAY. A SMALL CRAFT ADVISORY IS
LIKELY LATE SATURDAY INTO SUNDAY AS THE FLOW PICKS UP BEHIND THE
FRONT. BY MONDAY HIGH PRESSURE WILL BE NORTH OF THE LAKE WITH
ONSHORE FLOW.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK/KUBINA
SHORT TERM...TK
LONG TERM...MAYERS
AVIATION...KOSARIK
MARINE...MAYERS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
110 AM EDT FRI SEP 18 2015
.SYNOPSIS...
A COLD FRONT WILL APPROACH ON FRIDAY BEFORE PUSHING THROUGH THE
OHIO VALLEY ON SATURDAY...ALLOWING FOR SHOWERS AND PERHAPS A FEW
THUNDERSTORMS. HIGH PRESSURE AND COOLER TEMPERATURES WILL BUILD IN
BEHIND THE FRONT ON SUNDAY.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
UPSTREAM CONVECTION IS NOT SHOWING MUCH IN THE WAY OF BLOWOFF THAT
WAS EXPECTED TO PUSH INTO NW FCST AREA LATER THIS EVENING. HAVE
PARED BACK THE EXPECTED CLOUD COVER TO OCCUR MORE TOWARDS DAYBREAK
AND COINCIDE WITH THE PASSAGE OF H5 S/W THROUGH NRN OHIO. THIS IS
THE BRUNT OF THE FORECAST CHANGE THIS EVENING. ALSO PARED BACK
SOME IN THE CHANCES OF A SHOWER OCCURRING BEFORE DAYBREAK IN THE
NORTHWEST. CURRENT GUIDANCE STILL HAS THE S/W IN INDIANA AT 12Z
AND ALL BUT THE TINIEST SLIVER OF NW OHIO DRY THROUGH THIS TIME.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM SATURDAY/...
HAVE USED A BLEND OF THE GFS AND ECMWF FOR THE SHORT TERM
FORECAST.
COLD FRONT WILL MOVE A LITTLE FARTHER SOUTHEAST ON FRIDAY BUT
WILL REMAIN WELL TO OUR NORTHWEST. THERE COULD BE CONSIDERABLE
CLOUDS DURING THE MORNING HOURS RESULTING FROM PREVIOUS NIGHTS
CONVECTION TO OUR NORTHWEST. AGAIN...A FEW SHOWERS MAY BE SKIMMING
OUR NORTHWEST ZONES DURING THE MORNING. IT LOOKS LIKE ANY
SHOWER/THUNDERSTORM ACTIVITY WILL REMAIN CLOSER TO THE FRONT FOR
THE AFTERNOON HOURS. TEMPERATURES WILL BE CLOUD DEPENDENT BUT
SHOULD WARM INTO THE LOWER AND MID 80S ONCE AGAIN.
FOR FRIDAY NIGHT...POTENT S/WV WITHIN THE FLOW ALOFT WILL EJECT
NORTHEAST TO THE GREAT LAKES. A STRONG LLJ WILL TEAM UP WITH
FAVORABLE UPR DIV FROM THE RR QUAD OF AN UPR LVL JET TO PERTURB A
WAVE LOW PRESSURE ON THE FRONT. WIDESPREAD PCPN IS EXPECTED FROM
NRN IL...SRN WI...NRN IND...SRN MI AND THEN INTO NW OHIO. OUR AREA
WILL BE ON THE PERIPHERY OF THE BEST LOW LEVEL FORCING SO ONLY
HAVE CHANCE POPS IN THE FORECAST FOR THE NW TAPERING OFF TO A DRY
FORECAST MAINLY ALONG AND SOUTHEAST OF I-71. OVERNIGHT LOWS WILL
BE MAINLY IN THE 60S.
ON SATURDAY...AS WAVE OF LOW PRESSURE PASSES BY TO OUR NORTHEAST...
ATTENDANT COLD FRONT THEN WILL MOVE THROUGH OUR AREA. THE FRONT
WILL INTERACT WITH FAIRLY HIGH PWATS. HOWEVER...LIFT WILL BE
MAINLY FROM LOW LEVEL FRONTAL CONVERGENCE ALONG AND AHEAD OF THE
FRONT. WE SHOULD AT LEAST SEE LIKELY POPS FOR OUR WESTERN HALF OF
THE CWFA...BUT FRONTAL CONVERGENCE SEEMS TO WEAKEN AS IT MOVES
THROUGH THE REMAINDER OF THE AREA SATURDAY AFTERNOON AND
EVENING...SO HAVE CHANCE POPS ELSEWHERE. THERE SHOULD BE ENOUGH
INSTABILITY FOR EMBEDDED THUNDER.
BY SATURDAY NIGHT...THE COLD FRONT WILL EXIT TO OUR SOUTHEAST...
ALLOWING SURFACE HIGH PRESSURE TO BUILD IN FROM THE NORTHWEST.
DRIER AND COOLER WEATHER WILL FILTER INTO THE REGION. LOWS WILL
BOTTOM OUT IN THE UPPER 40S NORTH TO THE MID 50S ALONG AND SOUTH
OF THE OHIO RIVER.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
AT THE START OF THE EXTENDED FORECAST PERIOD...A COLD FRONT WILL BE
JUST SOUTHEAST OF THE ILN FORECAST AREA...WITH HIGH PRESSURE
BUILDING INTO THE SOUTHERN GREAT LAKES AND NORTHERN OHIO VALLEY.
THIS HIGH WILL BE FAIRLY DRY...PROVIDING A MOSTLY SUNNY DAY ON
SUNDAY...WITH HIGHS IN THE LOWER TO MID 70S.
THE FOCUS GOING INTO THE FIRST HALF OF THE WEEK WILL BE ON THE
FORMATION OF AN AREA OF UPPER LEVEL LOW PRESSURE...WHICH WILL
DEVELOP AS THE SURFACE HIGH TRANSLATES NORTHEAST. AT THE SAME
TIME...A SSW-TO-NNE ORIENTED SURFACE TROUGH WILL DEVELOP JUST WEST
OF THE APPALACHIAN MOUNTAINS...WITH MOISTURE AND PRECIPITATION
SPREADING ALONG THE MOUNTAINS AND INTO THE UPPER OHIO AND TENNESSEE
VALLEY REGIONS BY MONDAY NIGHT. THERE IS DECENT AGREEMENT BETWEEN
THE 12Z GFS/ECMWF THROUGH TUESDAY...AND BOTH MODELS SUGGEST THAT
MOST OF THE PRECIPITATION WILL REMAIN EAST OF THE ILN FORECAST AREA.
THUS...POPS HAVE BEEN SLIGHTLY LOWERED FROM THE PREVIOUS
FORECAST...WITH ONLY SLIGHT CHANCES OF SHOWERS EXPECTED ON MONDAY
AND TUESDAY (PERHAPS A LITTLE MORE LIKELY ON TUESDAY). WITH MODELS
INDICATING RELATIVELY STABLE CONDITIONS...THUNDER SEEMS UNLIKELY.
MODEL SPREAD INCREASES SIGNIFICANTLY BY WEDNESDAY...PRIMARILY WITH
REGARD TO THE LOCATION AND STRENGTH OF THE UPPER LOW. THE 12Z
OPERATIONAL RUNS LOOK VASTLY DIFFERENT TODAY THAN THEY DID
YESTERDAY. GFSE MEMBERS ARE SHOWING A POSITIONAL SPREAD OF AROUND
400 MILES WITH REGARDS TO THE CENTER OF THE UPPER LOW BY 12Z
WEDNESDAY MORNING...AND ARE SPREAD OUT ENOUGH BY WEDNESDAY EVENING
THAT THE ENSEMBLE MEAN IS SO DAMPENED AS TO MISS THE PRESENCE OF THE
CLOSED LOW ENTIRELY. THUS...THE FORECAST BEYOND TUESDAY IS OF VERY
LOW CONFIDENCE. A GRADUAL WARMING TREND THROUGH THE WEEK WILL BE
FORECAST...WITH TEMPERATURES RETURNING TO NEAR NORMAL BY THE MIDDLE
OF THE WEEK.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE REMAINS EAST OF THE AREA ALLOWING FOR LIGHT
SOUTHERLY FLOW ACROSS THE TAF SITES THIS MORNING. AN UPPER LEVEL
DISTURBANCE WILL BE CROSSING THE AREA FRIDAY WHICH WILL BRING A
CHANCE OF RAIN ACROSS THE NORTHERN PARTS OF THE AREA. HIGH RES
MODELS ARE SHOWING THE PRECIP FALLING APART AS THE DISTURBANCE
MOVES ACROSS THE AREA. KDAY WILL BE ON THE EDGE OF THE PRECIP AS
IT BEGINS TO FALL APART. FOR NOW HAVE LEFT THE MENTION OF PRECIP
OUT. BESIDES SOME POSSIBLE FOG AT KLUK THIS MORNING VFR CONDITIONS
EXPECTED THROUGH THE ISSUANCE.
OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...CONIGLIO/HICKMAN
NEAR TERM...FRANKS
SHORT TERM...CONIGLIO/HICKMAN
LONG TERM...HATZOS
AVIATION...HAINES
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
433 AM CDT FRI SEP 18 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 432 AM CDT FRI SEP 18 2015
AT THE SURFACE THIS MORNING...THE LOW LEVEL FRONTAL BOUNDARY HAS
PUSHED WELL SOUTH OF THE AREA...BUT MID LEVEL FRONT REMAINS LOCKED
FROM NEBRASKA PANHANDLE ACROSS THE CWA. HAD CLEARED ENOUGH EARLIER
WITH DIMINISHED NORTHERLY WINDS TO ALLOW TEMPS INTO THE UPPER 40S TO
LOWER 50S IN ALL BUT FAR SOUTH...AND DEWPOINTS TO FALL TOWARD 40 TO
45 IN SIMILAR AREAS. THE LARGER SCALE FEATURES IMPACTING THE
NORTHERN PLAINS ARE THE MAIN UPPER TROUGH PUSHING ACROSS WYOMING...
JET DIGGING AROUND THE BASE OF THE TROUGH TOWARD NORTHERN
COLORADO/SOUTHERN WYOMING...AND SECONDARY JET WITH LEADING NORTHERN
STREAM TROUGH FROM THE NORTHERN PLAINS TOWARD SOUTHWEST ONTARIO.
INITIAL PRECIPITATION ACROSS SOUTH CENTRAL SD AT 08Z HAS BEEN
ATTEMPTING TO STREAM NORTHEAST ALONG MID LEVEL BOUNDARY...BUT THE
DRIER LOW LEVEL AIR IN PLACE HAS BEEN CHALLENGING THE APPROACH
ACROSS SOUTHEAST SOUTH DAKOTA. WILL CONTINUE TO BE AN ISSUE WITH
SPREAD THROUGH EARLY MORNING...BUT DID FIND A NEED TO SPEED UP THE
SPREAD A BIT OVER EARLIER FORECAST...WHICH LOOKS TO HEAD LARGELY
ALONG/SOUTH OF I 90 IN MUCH OF THE AREA. PRECIP BASED A BIT LOWER IN
THE FRONTAL REALM SHOULD START TO POP UP PER ALMOST ALL MODEL
SOLUTIONS EARLY THIS MORNING TOWARD I 80 IN NEBRASKA WHERE CAN SEE
GATHERING MOISTURE IN THE FORM OF STRATUS BAND. AS THIS AREA OF
SHOWERS AND STORMS ENHANCES WITH APPROACH OF LARGER SCALE FORCING.
SOME HIGHER BASED INSTABILITY PROFILES SHOW WEAK INSTABILITY ABOVE
775 HPA CREEPING TOWARD THE LOWER MISSOURI VALLEY AND PARTS OF NW
IA...AND HAVE ADDED IN ISOLATED THUNDER. FAIRLY STRONG DYNAMICS LOOK
TO TAKE DIRECT AIM ACROSS THE FSD CWA FROM VERY LATE MORNING IN THE
FAR WEST...SPREADING ACROSS THE AREA THROUGH THE AFTERNOON...
ESPECIALLY STRONG WITH PV ADVECTION. MODELS SIMILAR IN DEVELOPING
ANTICYCLONICALLY CURVED OUTFLOW JET THROUGH MIDDAY FROM NORTHERN
MINNESOTA TO NORTHEAST SOUTH DAKOTA... INDICATIVE OF DECENT LATENT
HEAT RELEASE IN THE FRONTAL ZONE. CONFIDENCE IN PRECIPITATION IS
FAIRLY HIGH...AND HAVE RAISED THE POPS IN THE MID LEVEL FRONTAL ZONE
ACROSS THE MID/NORTH CWA A BIT MORE. ALSO...DURING THE AFTERNOON
CLOSER TO THE CORE OF THE UPPER WAVE WHERE TEMPS ALOFT ARE A BIT
COOLER...EXPERIMENTAL HRRR AND A COUPLE OTHER OF CAMS INDICATED
DEVELOPMENT OF SHOWERY AREA ACROSS CENTRAL SD WHICH ROTATES EASTWARD
WITH SOME AT LEAST WEAK INSTABILITY AND POTENTIAL FOR A FEW 50 DBZ
CORES...SUGGESTING A LOWER END THUNDER THREAT AS WELL. THIS AREA
SHOULD BE SOMEWHAT MORE LIMITED TO AREAS WEST OF THE JAMES RIVER
DURING THE MIDDAY/AFTERNOON HOURS. IF COULD MANAGE TO GET A BIT MORE
DIURNAL SUPPORT TO HEATING...COULD HAVE ENOUGH INSTABILITY TO
PERHAPS SEE AN OUTSIDE THREAT OF SOME VERY SMALL HAIL IN THE LOWER
BRULE AREA DURING THE EARLY TO MID AFTERNOON. HOWEVER...AT THIS TIME
APPEARS THAT ABUNDANCE OF CLOUDS AND THE PRESENCE OF PRECIP WILL
HOLD BACK HIGHS ENOUGH...MAINLY UPPER 50S TO MID 60S ACROSS THE AREA.
SHORT WAVELENGTH OF THE FEATURE COMPLICATES THOUGHTS OF KEEPING A
BIT MORE EXTENDED MENTION OF PRECIP CHANCE...AS WOULD TEND TO FOCUS
A MUCH GREATER PORTION OF THE PRECIP AHEAD OF TROUGH AXIS WHICH IS
THROUGH ALL BUT THE FAR EAST BY 00Z. HOWEVER...WITH CHANCE FOR A BIT
OF PRECIP IN DEFORMATION NORTH OF AXIS AND AT THIS TIME...WILL ALSO
INTRODUCE TRAILING SMALL BAND OF LOWER POPS...BUT SHOULD BE QUICKLY
DISSIPATING WITH THE OVERWHELMING LARGE SCALE TREND TO SUBSIDENCE
AND DRYING...AND THUS PRECIP SHOULD NOT TRAVERSE MUCH REAL ESTATE
BEFORE FADING AWAY. WINDS SHOULD ALSO WORK TOWARD DIMINISHING... AND
WITH CLEARING...WILL SEE A FEW NEAR 40 READINGS INTO THE NORTHERN
CWA...WITH MID 40S SOUTHEAST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 432 AM CDT FRI SEP 18 2015
SATURDAY AND SUNDAY LOOK DRY AND QUIET. HIGH PRESSURE ON SATURDAY
MORNING WILL DRIFT SOUTHEAST THROUGH THE DAY...ALLOWING WINDS TO
BACK AND TURN A BIT MORE SOUTHERLY. EVEN WITH ABUNDANT SUNSHINE THE
COOL ENVIRONMENT WILL LIKELY ONLY SUPPORT HIGH TEMPERATURES IN THE
MID 60S TO LOWER 70S.
THE SOUTHERLY GRADIENT INCREASES A BIT SATURDAY NIGHT INTO SUNDAY
WHICH WILL BRING MILDER LOWS ON SUNDAY MORNING...MAINLY UPPER 40S TO
LOWER 50S AND WARMER HIGHS...MOSTLY MID 70S.
IN THE OUTER PERIODS(MONDAY THROUGH THURSDAY)...MODELS STILL IN
PRETTY GOOD AGREEMENT BRINGING FLAT RIDGING INTO THE AREA ON MONDAY
THEN GRADUALLY BUILDING THE RIDGE BEFORE SWINGING A PRETTY STRONG
WAVE INTO THE AREA WEDNESDAY INTO THURSDAY. TIMING OF THIS WAVE OF
COURSE A BIT DIFFERENT FROM MODEL TO MODEL BUT EACH MODEL DOES HAVE
THIS ENERGY WORKING INTO THE AREA OVER THAT 48 HOUR PERIOD. PLUS THE
CANADIAN AND ECMWF HINT AT THE WAVE COMING OUT IN A COUPLE OF PIECES
WHILE THE GFS IS MORE COMPACT AND COMES OUT IN ONE STRONG PIECE.
SO...LOOKING AT DRY CONDITIONS ON MONDAY AND TUESDAY WITH GRADUALLY
INCREASING CHANCES WEDNESDAY INTO THURSDAY. AT THIS TIME WOULD
PINPOINT WEDNESDAY NIGHT AS THE HIGHEST PROBABILITY OF SHOWERS AND
THUNDERSTORMS. TOO TOUGH TO CALL ON TIMING RIGHT NOW. WILL ALSO NEED
TO KEEP AN EYE OUT FOR THE POTENTIAL FOR SEVERE WEATHER WITH THIS
ACTIVITY. OTHERWISE TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL
WITH HIGHS IN THE 70S TO MID 80S AND LOWS IN THE MID 50S TO LOWER
60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1051 PM CDT THU SEP 17 2015
MID AND HIGH CLOUDS WILL BE ON THE INCREASE OVERNIGHT...WITH SOME
LIGHT RAINFALL SPREADING INTO SOUTH CENTRAL SD AFTER 08Z. LIGHT
RAIN SPREADS EAST THROUGH THE DAY FRIDAY...WITH THE BEST CHANCES
IN SOUTH DAKOTA AND SOUTHWEST MINNESOTA. CONDITIONS WILL REMAIN
PREDOMINATELY VFR.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN
LONG TERM...08
AVIATION...
AREA FORECAST DISCUSSION
NWS GOODLAND KS
633 AM MDT FRI SEP 18 2015
.UPDATE...
ISSUED AT 626 AM MDT FRI SEP 18 2015
UPDATED FORECAST FOR TODAY BASED ON LATEST SATELLITE AND MODEL
DATA. PREVIOUS FORECAST HAD A GOOD HANDLE ON THE GENERAL TREND OF
THE RAINFALL...MAINLY SPED UP THE TIMING OF RAIN MOVING OUT OF THE
AREA BASED ON THE LOCATION OF THE ELEVATED CAPE AXIS AT 725MB.
ALSO LOWERED CHANCES FOR RAIN OVER THE NORTHWEST...PARTICULARLY
YUMA COUNTY...DUE TO SUBSIDENCE MOVING OVER THE AREA ON WATER
VAPOR. TIMING OUT THE EASTERN EDGE OF THE SUBSIDENCE HAS IT OVER
THE EASTERN BORDER OF THE TRI-STATE AREA BY 10 AM CT. HOWEVER DID
NOT WANT TO DEVIATE TOO MUCH FROM THE PREVIOUS FORECAST YET SO
HAVE CHANCES RAIN CONTINUING AFTER 10 AM CT BUT DO HAVE THEM
DECLINING FASTER THAN BEFORE.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 244 AM MDT FRI SEP 18 2015
SCATTERED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS WILL CONTINUE
THROUGH THE LATE MORNING/EARLY AFTERNOON AHEAD OF A SHORTWAVE
TROUGH MOVING OUT OF THE NORTHERN HIGH PLAINS. BEST CHANCES WILL
BE IN NEBRASKA. STORMS HAVE STRUGGLED SO FAR BUT HRRR SHOWS
REDEVELOPMENT FURTHER SOUTH BY 12Z SO WILL CONTINUE TO CARRY
SLIGHT TO MID RANGE POPS. MUCAPE GENERALLY LESS THAN 500 J/KG SO
CANNOT RULE OUT AN ISOLATED STRONGER STORM CAPABLE OF PRODUCING
SMALL HAIL. ACTIVITY WILL MOVE EAST BY EARLY AFTERNOON...BUT
STRATUS MAY LINGER UNTIL THEN PARTICULARLY IN EASTERN AREAS
LEADING TO A LOW CONFIDENCE AFTERNOON TEMPERATURE FORECAST.
SIMILARLY...LOW TEMPERATURES TONIGHT COMPLICATED BY REDEVELOPMENT
OF STRATUS AND PATCHY FOG...BUT WITH LIGHT WINDS MAY BE ABLE TO
DROP TO LOWER TO MIDDLE 40S BEFORE SATURATION OCCURS. CLOUDS BURN
OFF AGAIN BY SATURDAY AFTERNOON WITH TEMPERATURES WARMING INTO THE
MIDDLE 70S. MODELS HAVE BACKED OFF ELEVATED THUNDERSTORM POTENTIAL
FOR SATURDAY NIGHT AS IT LOOKS LIKE THE UPPER SHORTWAVE WILL BE
WEAKER AND FURTHER NORTH...SO REDUCED POPS TO SLIGHT CHANCE FOR
THE OVERNIGHT HOURS. SHORTWAVE RIDGING BUILDS IN BEHIND IT FOR
SUNDAY WITH TEMPERATURES REBOUNDING TO THE LOWER 80S UNDER MOSTLY
SUNNY SKIES.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 244 AM MDT FRI SEP 18 2015
A DRY START TO THE WORK WEEK IS EXPECTED AS UPPER LEVEL RIDGING
BUILDS OVER THE AREA FROM THE DESERT SOUTHWEST AND A LEE TROUGH
REDEVELOPS EAST OF THE ROCKIES. THIS SETUP WILL BRING DRIER
CONDITIONS TO THE HIGH PLAINS THROUGH TUESDAY NIGHT.
THE NEXT CHANCE FOR PRECIPITATION PRESENTS ITSELF WEDNESDAY THROUGH
THURSDAY. A SHORTWAVE TROUGH MOVES ONTO THE CALIFORNIA COAST TUESDAY
NIGHT AND TRAVELS OVER THE DESERT SOUTHWEST TOWARDS THE REGION. THE
TROUGH APPEARS TO WEAKEN BUT IT LOOKS LIKE MULTIPLE DISTURBANCES
WILL MOVE THROUGH THE UPPER LEVEL FLOW MIDWEEK GENERATING SHOWER AND
THUNDERSTORM CHANCES FOR THE AREA.
RELATIVELY CONSISTENT TEMPERATURES ARE EXPECTED IN THE EXTENDED
PERIOD WITH HIGHS IN THE MID 80S TO NEAR 90S DEGREES AND LOWS IN THE
MID 50S TO LOW 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 516 AM MDT FRI SEP 18 2015
SCATTERED SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM WILL IMPACT
KMCK THROUGH THE MORNING. LOW CEILINGS WILL IMPACT BOTH KGLD AND
KMCK THROUGH EARLY AFTERNOON WITH MOIST UPSLOPE FLOW AT THE
SURFACE. FLIGHT CATEGORIES COULD DROP TO IFR BEFORE CEILINGS
SCATTER OUT THIS AFTERNOON. TONIGHT...EXPECTING STRATUS AND PATCHY
FOG TO REDEVELOP AFTER MIDNIGHT WITH FLIGHT CATEGORY RESTRICTIONS
POSSIBLE ONCE AGAIN.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...024
LONG TERM...JBH
AVIATION...024
AREA FORECAST DISCUSSION
NWS GOODLAND KS
519 AM MDT FRI SEP 18 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 244 AM MDT FRI SEP 18 2015
SCATTERED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS WILL CONTINUE
THROUGH THE LATE MORNING/EARLY AFTERNOON AHEAD OF A SHORTWAVE
TROUGH MOVING OUT OF THE NORTHERN HIGH PLAINS. BEST CHANCES WILL
BE IN NEBRASKA. STORMS HAVE STRUGGLED SO FAR BUT HRRR SHOWS
REDEVELOPMENT FURTHER SOUTH BY 12Z SO WILL CONTINUE TO CARRY
SLIGHT TO MID RANGE POPS. MUCAPE GENERALLY LESS THAN 500 J/KG SO
CANNOT RULE OUT AN ISOLATED STRONGER STORM CAPABLE OF PRODUCING
SMALL HAIL. ACTIVITY WILL MOVE EAST BY EARLY AFTERNOON...BUT
STRATUS MAY LINGER UNTIL THEN PARTICULARLY IN EASTERN AREAS
LEADING TO A LOW CONFIDENCE AFTERNOON TEMPERATURE FORECAST.
SIMILARLY...LOW TEMPERATURES TONIGHT COMPLICATED BY REDEVELOPMENT
OF STRATUS AND PATCHY FOG...BUT WITH LIGHT WINDS MAY BE ABLE TO
DROP TO LOWER TO MIDDLE 40S BEFORE SATURATION OCCURS. CLOUDS BURN
OFF AGAIN BY SATURDAY AFTERNOON WITH TEMPERATURES WARMING INTO THE
MIDDLE 70S. MODELS HAVE BACKED OFF ELEVATED THUNDERSTORM POTENTIAL
FOR SATURDAY NIGHT AS IT LOOKS LIKE THE UPPER SHORTWAVE WILL BE
WEAKER AND FURTHER NORTH...SO REDUCED POPS TO SLIGHT CHANCE FOR
THE OVERNIGHT HOURS. SHORTWAVE RIDGING BUILDS IN BEHIND IT FOR
SUNDAY WITH TEMPERATURES REBOUNDING TO THE LOWER 80S UNDER MOSTLY
SUNNY SKIES.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 244 AM MDT FRI SEP 18 2015
A DRY START TO THE WORK WEEK IS EXPECTED AS UPPER LEVEL RIDGING
BUILDS OVER THE AREA FROM THE DESERT SOUTHWEST AND A LEE TROUGH
REDEVELOPS EAST OF THE ROCKIES. THIS SETUP WILL BRING DRIER
CONDITIONS TO THE HIGH PLAINS THROUGH TUESDAY NIGHT.
THE NEXT CHANCE FOR PRECIPITATION PRESENTS ITSELF WEDNESDAY THROUGH
THURSDAY. A SHORTWAVE TROUGH MOVES ONTO THE CALIFORNIA COAST TUESDAY
NIGHT AND TRAVELS OVER THE DESERT SOUTHWEST TOWARDS THE REGION. THE
TROUGH APPEARS TO WEAKEN BUT IT LOOKS LIKE MULTIPLE DISTURBANCES
WILL MOVE THROUGH THE UPPER LEVEL FLOW MIDWEEK GENERATING SHOWER AND
THUNDERSTORM CHANCES FOR THE AREA.
RELATIVELY CONSISTENT TEMPERATURES ARE EXPECTED IN THE EXTENDED
PERIOD WITH HIGHS IN THE MID 80S TO NEAR 90S DEGREES AND LOWS IN THE
MID 50S TO LOW 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 516 AM MDT FRI SEP 18 2015
SCATTERED SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM WILL IMPACT
KMCK THROUGH THE MORNING. LOW CEILINGS WILL IMPACT BOTH KGLD AND
KMCK THROUGH EARLY AFTERNOON WITH MOIST UPSLOPE FLOW AT THE
SURFACE. FLIGHT CATEGORIES COULD DROP TO IFR BEFORE CEILINGS
SCATTER OUT THIS AFTERNOON. TONIGHT...EXPECTING STRATUS AND PATCHY
FOG TO REDEVELOP AFTER MIDNIGHT WITH FLIGHT CATEGORY RESTRICTIONS
POSSIBLE ONCE AGAIN.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...024
LONG TERM...JBH
AVIATION...024
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
605 AM CDT FRI SEP 18 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM CDT FRI SEP 18 2015
MAIN CONCERN FOR THE SHORT TERM REVOLVES AROUND RAIN CHANCES WITH
UPPER WAVE MOVING THROUGH WYOMING THIS MORNING. GUIDANCE IS IN
GOOD AGREEMENT ON THIS WAVE AND ITS ASSOCIATED PV ANOMALY TRACKING
ACROSS SRN MN THIS AFTERNOON. THOUGH THIS WAVE WILL PACK A PRETTY
STRONG PUNCH...AS EVIDENCE BY A BETTER THAN 10 UNIT PV
ANOMALY...IT WILL BE ENCOUNTERING A RATHER DRY ANTECEDENT AIRMASS
IN THE WAKE OF THE COLD FRONT THAT PASSED THROUGH LAST
NIGHT...WHICH AT 3 AM WAS STRETCHED OUT FROM NW MO...TO THE QUAD
CITIES AND UP TOWARD MARQUETTE MICHIGAN. IT IS THIS DRY AIR THAT
IS LEADING TO A BIT OF SPREAD IN THE MODELS AS TO HOW MUCH RAIN WE
WILL SEE.
FIRST...THE BULK OF THE RAIN WITH THIS SYSTEM WILL REMAIN WELL OFF
TO OUR SE OUT AHEAD OF A 50 KT LLJ THAT WILL GO FROM MO TOWARD
LOWER MICHIGAN. FOR US...THERE WILL BE TWO PIECES OF FORCING THAT
WILL TRY TO GENERATE PRECIP. ONE WILL BE A BAND OF FGEN IN THE
H7-H6 LAYER. THIS BIT OF FORCING CAN BE SEEN IN THE BAND OF
SHOWERS EXTENDING FROM SE WYOMING TO WHERE THE MO RIVER MEETS THE
SD/NEB BORDER. FOLLOWING THE RAP/NAM...THIS BAND WILL TRACK ENE TO
THE NORTH OF A SFC LOW THAT WILL GO UP ALONG THE COLD
FRONT...GOING FROM ROUGHLY FAIRMONT TO EAU CLAIRE. THE SECOND
BATCH OF FORCING IS BEING FORCED BY THE PV ANOMALY AND IS WHAT IS
FORCING THE SHOWERS MOVING ACROSS THE WRN ND/SD BORDER. THIS
FEATURE AND LIGHT SHOWERS WILL BASICALLY MOVE DUE EAST AND IS WHAT
WILL BRING A CHANCE FOR RAIN TO JUST ABOUT THE ENTIRE AREA.
FOR POPS...SLOWED DOWN THE ARRIVAL OF RAIN THIS MORNING QUITE A
BIT...WITH THE CAMS THAT DO SHOW PRECIP REACHING THE GROUND NOT
SHOWING IT DOING SO ANYWHERE IN THE MPX CWA UNTIL CLOSE TO 18Z.
THIS WAVE WILL BE PROGRESSIVE ENOUGH THAT BY ABOUT THE TIME THE
ATMOSPHERE BECOMES MOIST ENOUGH TO ALLOW RAIN TO HIT THE GROUND...
THE FORCING WILL BE ON ITS WAY OUT. AS RESULT...EXPECT MOST PLACES
TO SEE LESS THAN A TENTH OF AN INCH OF RAIN...WITH THE HEAVIEST
RAIN EXPECTED TO FALL WITH THE H7-H6 FGEN BAND FROM FAIRMONT TO
EAU CLAIRE...BUT EVEN THERE AMOUNTS WILL BE UNDER A QUARTER OF AN
INCH.
FOR HIGHS...WITH EXTENSIVE CLOUD COVER EXPECTED...FAVORED THEM
TOWARD THE COOLER CONSENSUS RAW MODEL NUMBERS...WITH HIGHS ONLY IN
THE LOWER 60S EXPECTED IN SOUTH CENTRAL MN IF THAT SRN FGEN BAND
CAN SETUP AND BECOME DOMINATE. FOR TONIGHT...SKIES WILL QUICKLY
CLEAR OUT IN THE WAKE OF THE PV ANOMALY...WITH TEMPERATURES
QUICKLY FALLING BACK INTO THE 40S/50S LIKE WE SAW THIS PAST
EVENING.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 430 AM CDT FRI SEP 18 2015
SATURDAY THROUGH MONDAY...SFC HIGH PRES WILL SLOWLY LUMBER ACROSS
THE REGION FROM THE CENTRAL PLAINS INTO THE OHIO VALLEY OVER THE
WEEKEND INTO EARLY NEXT WEEK. THIS WILL PRIMARILY PREVENT
PRECIPITATION FROM OCCURRING...DESPITE THE PASSAGE OF A SHORTWAVE
UPR LVL TROF ON SUNDAY. MOSTLY CLEAR SKIES ON SATURDAY WILL BE
FOLLOWED WITH A LITTLE MORE CLOUD COVER ON SUNDAY IN RESPONSE TO
THE UPPER LEVEL DISTURBANCE...POSSIBLY SOME VIRGA...BUT NO
PRECIPITATION IS EXPECTED. MOSTLY CLEAR SKIES THEN RETURN ON
MONDAY AS A ZONAL FLOW RESUMES. A SLOW WARMING TREND WILL CONTINUE
AS HIGHS CLIMB OUT OF THE 60S AND INTO THE LOW 70S.
TUESDAY THROUGH THURSDAY...A LONGWAVE CENTRAL CONUS RIDGE BUILDING
OUT OF THE DEEP SOUTH EARLY TUE WILL SLOWLY SHIFT OFF TO THE E
WHILE A LONGWAVE TROF MOVES ONSHORE THE W COAST. THIS WILL HELP
DEVELOP A WELL-ORGANIZED LOW PRES SYSTEM OVER THE ROCKIES WED THAT
WILL SHIFT INTO THE N-CENTRAL CONUS THU. A LEADING WARM FRONT WILL
EXTEND INTO THE UPR MISS RIVER VALLEY MIDWEEK...WHILE WEAK LOW
PRES CENTERS RIDE ALONG THE QUASI-STATIONARY FRONT...MAKING FOR
ISOLD TO SCT SHOWER/THUNDERSTORM DEVELOPMENT FOR LATE TUE THRU
THU WHILE THE MAIN SYSTEM REMAINS TO THE W OF THE AREA. THE
ADDITIONAL CLOUD/RAIN COMPLICATIONS WILL REDUCE TEMPERATURES
SLIGHTLY BUT NO SIGNIFICANT CHANGE IN AIRMASS IS EXPECTED THRU
MIDWEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 605 AM CDT FRI SEP 18 2015
GIVEN CURRENT RADAR ACROSS SODAK/NEB...HARD TO ARGUE AGAINST WHAT
THE HRRR AND HOPWRF ARE SHOWING WITH LIGHT RAIN MOVING ACROSS ALL
TERMINALS THIS AFTERNOON AS THE UPPER LOW CURRENTLY OVER WYOMING
MOVES ACROSS SRN MN. AS RESULT...ADDED A SHRA MENTION TO ALL
TERMINALS...THOUGH VFR CONDITIONS WILL ACCOMPANY THIS RAIN. BEHIND
THE UPPER WAVE...SKIES WILL CLEAR OUT...WITH WINDS STAYING UP
ENOUGH TO KEEP ANY FOG FROM FORMING GOING INTO SATURDAY MORNING.
KMSP...RAIN ALREADY MOVING INTO FSD AND THE HRRR SHOWS THIS FINGER
OF FORCING WORKING UP TOWARD MSP THIS MORNING. IT WILL BE BATTLING
DRY AIR...BUT SEEING ENOUGH MODELS PUSHING RAIN INTO/NEAR MSP BY
18Z TO WARRANT MOVING UP THE SHRA MENTION. WILL LIKELY SEE SEVERAL
HOURS WITH ON AND OFF LIGHT RAIN...THOUGH CONFIDENCE IS HIGH THAT
CIG/VIS WILL REMAIN VFR GIVEN HOW DRY THE CURRENT AIRMASS IS.
/OUTLOOK FOR KMSP/
SAT...VFR. WIND W 6-10 KTS.
SUN...VFR. WIND SSW 12-15 KTS.
MON...VFR. WIND SSW 15-20 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JPC
AVIATION...MPG
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
925 AM MDT FRI SEP 18 2015
.UPDATE...
MADE A FEW CHANGES TO THE FORECAST THIS MORNING BASED ON
RADAR...SATELLITE AND MODEL TRENDS. WATER VAPOR SHOWED THE STRONG
VORTICITY MOVING E OUT OF NE WY...AND IR SHOWED WARMING CLOUD
TOPS OVER SE MT. RADARS SHOWED SHOWERS CONFINED TO EXTREME SE MT
MOVING E. WRF AND HRRR HAD PRECIPITATION MOVING OUT BY 18Z...SO
HAVE ADJUSTED POPS TO REFLECT THESE TRENDS. MESOANALYSIS SHOWED
STABLE AIR OVER THE SE...SO NOT EXPECTING ANY THUNDER. ADJUSTED
SKY COVER TO REFLECT LATEST VISIBLE SATELLITE AND ADJUSTED
AFTERNOON SKY COVER TO REFLECT SOME CLOUD COVER MOVING INTO THE
REGION FROM THE W AS A COUPLE OF WEAK PACIFIC WAVES MOVE INTO THE
AREA. REMOVED MORNING FOG. MADE SMALL WIND ADJUSTMENTS BASED ON
LATEST OBSERVATIONS. IT MAY BE A LITTLE BREEZY AT TIMES
TODAY...BUT IN GENERAL WINDS ALOFT WERE NOT OVERLY STRONG.
TEMPERATURES WERE IN GOOD SHAPE. REMAINDER OF SHORT-TERM PERIOD
CONTINUED TO LOOK DRY. ARTHUR
&&
.SHORT TERM...VALID FOR TDY AND SAT...
SHOWERS SET TO LINGER IN SE CORNER OF MONTANA AND POSSIBLY BACK
INTO THE BIG HORNS EARLY THIS MORNING BEFORE MOVING OFF TO THE
E/SE WITH THE ASSOCIATED WEATHER SYSTEM. DEWPOINT SPREADS ARE
SOMEWHAT NARROW EARLY THIS MORNING...SO WILL PLACE SOME PATCHY FOG
IN THE MORNING PERIOD FOR MOST LOCATIONS. SHORT WAVE RIDGE WILL
THEN PREVAIL TODAY ALTERNATING WITH A SHORT WAVE TROUGH AGAIN
TONIGHT INTO SATURDAY. HOWEVER...THIS NEXT TROUGH DOES NOT HAVE
MUCH MOISTURE TO WORK WITH AND TRACKS FURTHER NORTH. THERE ARE NOT
ANY PROGGS WITH MEASURABLE PRECIPITATION WHICH SUPPORTS OUR
THOUGHTS OF A DRY SYSTEM. SO WILL KEEP POPS AT ZERO FOR TONIGHT
THROUGH SATURDAY. DESPITE THE ALTERNATING SHORT WAVE
RIDGES/TROUGHS...TEMPERATURE PROGGS CONTINUE TO SUGGEST A MODEST
WARMING TREND...ESPECIALLY FOR THE WEEKEND. SO NO BIG CHANGES IN
THIS REGARD FROM PREVIOUS FORECASTS.
ZONAL FLOW RETURNS FOR SAT NIGHT RESULTING IN LEE-SIDE TROUGHING.
THE SURFACE LOW REMAINS WAY NORTH AND THE PRESSURE GRADIENT DOES
NOT LOOK VERY STRONG. OUR LOCAL WIND TOOLS ARE NOT INDICATING ANY
RISK OF ADVISORY LEVEL GAP WINDS AT KLVM AND NYE. THUS...BACKED
OFF A BIT ON WINDS SATURDAY NIGHT FOR THE FOOTHILLS. BT
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
MINIMAL CHANGES TO THE INHERITED EXTENDED FORECAST ONCE AGAIN
THIS MORNING...AS MODELS APPEAR TO BE IN PRETTY GOOD
AGREEMENT THROUGHOUT THE PERIOD.
THE PERIOD BEGINS SUNDAY...WITH A LITTLE SHORTWAVE RIDGING
CROSSING THE REGION IN ADVANCE OF DEVELOPING ZONAL FLOW.
THEREFORE...RAISED TEMPS SLIGHTLY FOR SUNDAY. RELATIVELY FAST
ZONAL FLOW BEGINS TO DOMINATE THE PATTERN BY SUNDAY NIGHT...AND
PERSIST THROUGH LATE MONDAY/EARLY TUESDAY. THERE ARE SEVERAL
WAVES OF PACIFIC ENERGY CROSSING THIS FLOW...BUT THE MAJORITY OF
IT APPEARS TO STAY NORTH OF THE CWA...RESULTING A WARM AND DRY
DOWNSLOPE PATTERN FOR THE BEGINNING OF THE WORK WEEK. THE BEST
POTENTIAL DURING THIS PERIOD APPEARS TO BE MONDAY NIGHT...AS A
FAST MOVING UPPER LEVEL LOW SWING A WEAK COLD FRONT A LITTLE
DEEPER INTO NORTHERN PORTIONS OF THE AREA...RESULTING IN SOME
ISOLATE SHOWER POTENTIAL ACROSS THE NORTHERN TIER OF THE REGION.
COLD FRONT DOES NOT APPEAR TO AFFECT TEMPS MUCH...BUT DOES USHER
IN THE RETURN OF SOUTHWEST FLOW INTO THE REGION AND SHALLOW
RIDGING DEVELOPS IN THE DAKOTAS. THE DEPTH OF THE SOUTHWEST FLOW
THURSDAY AND FRIDAY ARE THE BIGGEST DIFFERENCE IN THE
MODELS...WHICH WILL DETERMINE IF A SUB-TROPICAL DISTURBANCE
REACHES THE REGION FROM THE CALIFORNIA/ARIZONA AREA OR NOT. THE
ECMWF IS CURRENT LOOKING MORE FAVORABLY OF THE DISTURBANCE GETTING
INTO THE REGION. HAVE CARRIED ON WITH SLIGHT POPS FOR
THURSDAY...AND INTRODUCED SLIGHT POPS FOR FRIDAY...AS MORE ENERGY
AND MOISTURE ASSOCIATED WITH THIS DISTURBANCE IS PROGGED ACROSS
THE REGION. IF THIS SYSTEM DOES GET INTO THE REGION...A MUCH MORE
SIGNIFICANT PRECIP EVENT WOULD BE POSSIBLE. AAG &&
.AVIATION...
VFR CONDITIONS WILL PREVAIL ACROSS MUCH OF THE REGION THROUGHOUT
THE DAY. DRY AIR COMING INTO THE REGION WILL BRING CLEARING FORM
WEST TO EAST THROUGH THE DAY. AAG/REIMER
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SAT SUN MON TUE WED THU
-------------------------------------------------------
BIL 068 045/074 048/081 053/078 049/078 053/078 052/078
0/B 00/B 00/B 01/U 21/B 11/B 12/T
LVM 064 038/069 042/078 046/076 044/077 047/078 047/077
0/B 00/N 01/N 01/N 21/B 11/B 12/T
HDN 070 042/076 044/083 048/080 047/081 050/080 049/080
0/B 00/B 00/U 01/U 11/B 12/W 12/T
MLS 070 047/075 047/083 053/080 049/080 052/079 052/080
0/B 00/B 00/U 01/U 21/B 12/W 12/T
4BQ 067 045/074 046/081 050/081 050/081 052/080 051/080
2/W 00/B 00/U 01/U 11/U 12/T 12/T
BHK 067 044/073 046/081 051/079 047/075 050/077 050/077
0/B 00/B 00/U 01/U 11/N 12/W 12/T
SHR 066 039/073 041/081 045/081 045/081 048/080 048/081
0/B 00/B 00/U 01/U 11/U 12/W 12/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
623 AM CDT FRI SEP 18 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 335 AM CDT FRI SEP 18 2015
THE PRIMARY FORECAST CONCERNS ARE PCPN CHANCES/COVERAGE TODAY INTO
THIS EVENING...POTENTIAL FOR LOW CLOUDS AND OR PATCHY FOG TONIGHT
AND TEMPERATURES THE NEXT FEW DAYS.
MAIN FEATURES FROM UPPER LEVEL CHARTS LAST EVENING INCLUDED THE
FOLLOWING. A JET MAX OF 80-90 KNOTS AT 300 MB WAS OVER WY AND CO
LIFTING NORTHEAST. BEST 12 HOUR HEIGHT FALLS AT 500 MB WERE OVER
THE NRN PLAINS AND LIFTING INTO CANADA...BUT THE MAIN TROUGH AXIS
WAS STILL BACK OVER THE ROCKIES. THERMAL RIDGE AT 700 MB HAD
FLATTENED A BIT...AND EXTENDED FROM SRN NM INTO CNTRL MO. 850 MB
SHOWED HIGH PRES OVER THE DKTS AND N WINDS OVER THE CNTRL PLAINS
WITH CDFNT CURVING FROM WRN WI INTO NERN KS THEN BACK INTO ERN CO.
SFC ANLYS AT 08Z SHOWED TEMPERATURES IN THE 50S ACROSS OUR NRN
ZONES AND UPPER 60S/LOWER 70S NEAR THE KS AND MO BORDERS.
SHORT RANGE MODELS ARE IN FAIRLY GOOD AGREEMENT SHOWING PCPN
COVERAGE INCREASING THIS MORNING. PCPN CHANCES ARE HIGHEST ACROSS
OUR ERN AND SRN COUNTIES INTO MID AFTN. WILL MENTION AT LEAST
ISOLD TSTMS EVEN INTO PARTS OF NERN NE WITH ELEVATED INSTABILITY
MUCH OF THE DAY. USED SPC SREF MU CAPE OF 500 J/KG OR MORE AND
FCST SOUNDINGS TO HELP DETERMINE AREA WITH THUNDER POTENTIAL.
RECENT EXPERIMENTAL HRRR RUNS SEEM REASONABLE WITH PCPN COVERAGE
AND TIMING. WILL STAY FAIRLY CLOSE TO MOS GUIDANCE FOR HIGHS
TODAY...GENERALLY MID OR UPPER 60S...BUT SOME LOWER 70S PSBL IN
THE S. MAIN AREA OF SHOWERS WILL BE MOVING EAST OUT OF OUR AREA
EARLY THIS EVENING...BUT AN AREA OF LIGHT PCPN COULD MOVE OUT OF
CNTRL NE/CNTRL SD INTO PARTS OF NERN NE BEFORE ENDING EARLY THIS
EVENING. QUESTION THEN BECOMES...HOW MUCH CLEARING WILL OCCUR.
PRESSURE GRADIENT REMAINS MODEST...SO FOG POTENTIAL DOES NOT
APPEAR OVERLY HIGH. BUT...WE MAY SEE SOME STRATUS. NAM IS THE
MOST AGGRESSIVE WITH LOW CLOUDS TONIGHT. KEPT SOME CLOUDS IN...
BUT DID NOT COMPLETELY BUY INTO THE NAM OUTPUT AT THIS POINT.
SATURDAY THROUGH SUNDAY SHOULD BE DRY...WITH HIGHS SATURDAY MAINLY
IN THE UPPER 60S AND HIGHS SUNDAY IN THE 70S.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 335 AM CDT FRI SEP 18 2015
TEMPERATURES SHOULD SLOWLY MODERATE THROUGH MID WEEK...THEN DROP
OFF A BIT TOWARD THURSDAY/FRIDAY. A MID LEVEL RIDGE WILL BUILD
EAST FROM THE ROCKIES...THEN EXTEND FROM MEXICO TOWARD THE GREAT
LAKES REGION BY THURSDAY. THERE WILL BE SOME LOW CHANCES FOR
SHOWERS AND THUNDERSTORMS...MAINLY FROM MONDAY NIGHT INTO TUESDAY
THEN WEDNESDAY NIGHT INTO THURSDAY NIGHT.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 614 AM CDT FRI SEP 18 2015
RA WILL BE ON THE INCREASE THIS MRNG FOR THE KOMA/KLNK TERMINALS.
THE RA WILL LIKELY STAY TO THE NORTHWEST AND SOUTH OF THE KOFK TAF
SITE...BUT WILL INCLUDE A VC MENTION. WILL INCLUDE A MENTION OF A
COUPLE HOURS OF THUNDER IN BOTH KLNK AND KOMA AS THE BEST FORCING
MOVES THROUGH THIS MRNG. WE MAY SEE SOME MVFR VISBY IN THE
TSRA...BUT OTHERWISE VFR CONDITIONS ARE EXPECTED TODAY WITH A BKN-
OVC MID LEVEL CLOUD DECK. THE RA WILL MOV OUT BY MID AFTN WITH
SOME DECREASE IN CLOUDS THIS EVENING. SOME UNCERTAINTY IN HOW
CLEAR SKIES WILL BECOME OVERNIGHT SO WILL LEAVE IN A SCT DECK FOR
NOW. NORTHEAST WINDS THIS MRNG WILL BECOME NORTHWEST THIS AFTN AS
THE STORM SYSTEM PASSES TO OUR EAST.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...BOUSTEAD
AREA FORECAST DISCUSSION
NWS NORMAN OK
1103 AM CDT FRI SEP 18 2015
.UPDATE...
UPDATED PRECIP/WX THROUGH THE AFTN/EVENING...
&&
.DISCUSSION...
CONVECTION THIS MORNING HAS BEEN A BIT MORE AGGRESSIVE THAN
PREVIOUSLY ANTICIPATED. THIS ACTIVITY CONTINUES TO BE DRIVEN BY A
SUBTLE LOW LEVEL BAROCLINIC ZONE... MARKED BY A CORRIDOR OF
925-850 THETA E ADVECTION FROM FAR WRN N TX INTO NORTH CENTRAL OK.
UPPER LEVEL SUPPORT HAS BEEN PROVIDED BY A SHORT WAVE CURRENTLY
MOVING ACROSS NERN NM INTO THE PANHANDLES... WELL VISUALIZED ON
WV. 16Z SFC ANALYSIS HAS THE COLD FRONT KNOCKING ON THE DOOR IN
NWRN OK... AND IS EXPECTED TO START TO PUSH S/SE BY NOON. BIG
QUESTION AT THE MOMENT IS WHAT... IF ANY... RESIDUAL IMPACT EXISTS
FROM CURRENT CONVECTION ON ATMOSPHERIC RECOVERY THIS AFTN.
MESOSCALE GUIDANCE FROM THE HRRR HAS STRUGGLE OVER THE PAST TWO
HRS WITH THE CURRENT CONVECTION... WITH THE 12Z NAM HAVING A
SLIGHTLY BETTER GRASP WITH ITS CONV PRECIP. AT PRESENT... AHEAD OF
THE CURRENT CONVECTION... DPTS REMAIN POOLED IN THE UPPER
60S/LOWER 70S ACROSS CENTRAL OK AND TEMPS HAVE ALREADY REACHED THE
LOW/MID 80S THROUGH 16Z. THEREFORE... STILL ANTICIPATE A SECOND
ROUND OF CONVECTION AS THE FRONT PUSHES ACROSS THE STATE THIS AFTN
AND EVENING. THE PRIMARY HAZARDS WILL BE DAMAGING WINDS... 70 TO
80 MPH AND FREQUENT LIGHTNING. HAIL UP TO GOLF BALL SIZE WILL ALSO
BE POSSIBLE. STORMS WILL BECOME MORE LINEAR THROUGH THE EVENING...
WITH THE SEVERE HAZARDS SLOWLY DIMINISHING THROUGH MIDNIGHT AS
THEY MOVE INTO SOUTHERN OKLAHOMA... TOWARDS THE RED RIVER.
IF YOU HAVE OUTDOOR PLANS TONIGHT... SUCH AS HIGH SCHOOL FOOTBALL
OR THE OKLAHOMA STATE FAIR... SCOUT OUT GOOD SHELTER LOCATIONS
WHEN YOU ARRIVE AT YOUR VENUE... BLEACHERS AND LIGHTNING DO NOT
MIX. DO NOT WAIT TO SEEK SHELTER WHEN YOU SEE LIGHTNING... WHEN
THUNDER ROARS... GO IN DOORS.
JTK
&&
.PREV DISCUSSION... /ISSUED 617 AM CDT FRI SEP 18 2015/
DISCUSSION...
PLEASE SEE THE 12Z AVIATION DISCUSSION BELOW.
AVIATION...
A FEW SHOWERS AND STORMS WILL BE POSSIBLE NEAR CSM THIS MORNING.
LATER THIS EVENING...A COLD FRONT WILL MOVE INTO OK. SHOWERS AND
STORMS WILL INCREASE ALONG THIS COLD FRONT FROM NEAR WWR TO PNC
AND THEN SPREAD SOUTHWARD OVER MOST OF THE OTHER TERMINALS LATER
TONIGHT. EXACT TIMING AND COVERAGE ARE STILL QUESTIONABLE SO WILL
INCLUDE PROB30 GROUPS FOR THOSE TERMINALS WHERE THERE ARE STILL
SOME UNCERTAINTIES. EXPECT GUSTY SOUTH WINDS LATE THIS MORNING
THROUGH THIS AFTERNOON...WITH NORTH WINDS FOLLOWING THE FRONT
LATER TONIGHT.
PREV DISCUSSION... /ISSUED 449 AM CDT FRI SEP 18 2015/
DISCUSSION...
SHOWERS AND THUNDERSTORMS HAVE DEVELOPED NEAR THE FRONT EARLY
THIS MORNING ACROSS SOUTH CENTRAL AND SE KS. A FEW WEAK ECHOES
HAVE ALSO DEVELOPED NEAR WOODWARD. ISOLATED SHOWERS/STORMS WILL
BE POSSIBLE BEFORE SUNRISE ACROSS N/NW OK BUT VERY LITTLE RAINFALL
IS ANTICIPATED. LATER THIS MORNING A WEAK MID TO UPPER LEVEL
SHORTWAVE MOVING OUT OF NM WILL RESULT IN SUBTLE HEIGHT FALLS
ACROSS OK. SHOWER AND THUNDERSTORM COVERAGE MAY INCREASE A BIT WITH
THIS FEATURE JUST AHEAD OF THE FRONT BEFORE LUNCHTIME. DEPENDING
ON COVERAGE...THIS MAY RESULT IN A DIFFICULT TEMP FORECAST AHEAD
OF THE FRONT THIS AFTERNOON AS IT MOVES INTO NW OK. THE MORNING
ACTIVITY WILL ALSO HAVE AN IMPACT ON POTENTIAL INSTABILITY FOR
THIS AFTERNOON. FOR NOW...IT APPEARS A NARROW AXIS OF INSTABILITY
WILL DEVELOP ALONG THE FRONT LATE THIS AFTERNOON/EARLY THIS
EVENING FROM JUST WEST OF PNC TO CAMARGO. MID LEVEL LAPSE RATES
DO NOT APPEAR THEY WILL BE OVERLY IMPRESSIVE...IN ADDITION TO
EFFECTIVE DEEP SHEAR...SO SIGNIFICANT HAIL CHANCES APPEAR LOW.
DAMAGING WINDS UP TO 70 MPH...HOWEVER...WILL BE POSSIBLE GIVEN
HIGH LCLS/DRY SUB CLOUD LAYER. THE MOST LIKELY TIMING FOR SEVERE
WIND GUSTS WILL BE AROUND 5PM-MIDNIGHT AS SFC CONVERGENCE
INCREASES ALONG OF THE FRONT NEAR THE I44 CORRIDOR. AT LEAST ONE
MCS APPEARS POSSIBLE THROUGH LATE TONIGHT AS LOW LEVEL SHEAR
INCREASES.
THE FRONT WILL CONTINUE INTO NORTH TX EARLY SAT AM...AND LIKELY
BECOME STATIONARY THROUGH NORTH CENTRAL TX SATURDAY. RAIN CHANCES
WILL SHIFT ACROSS THE SOUTHERN ZONES SATURDAY AND THEN LIFT
NORTHWARD SUN AM MAINLY ALONG AND SOUTH OF I40. POPS WILL LINGER
ACROSS THE CENTRAL AND E/SE ZONES THROUGH EARLY MONDAY ALONG A SFC
TROUGH. FINALLY...BY TUESDAY...THE SUBTROPICAL RIDGE WILL BEGIN TO
BUILD BACK OVER THE SOUTHERN PLAINS RESULTING IN A WARM UP AND
DECREASING/LITTLE RAIN CHANCES THROUGH THE REST OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 94 64 77 60 / 50 80 20 30
HOBART OK 95 65 77 61 / 50 80 30 50
WICHITA FALLS TX 98 70 83 65 / 20 50 40 40
GAGE OK 89 57 76 56 / 40 30 10 30
PONCA CITY OK 89 59 75 55 / 70 70 10 20
DURANT OK 95 71 84 66 / 0 40 30 30
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
654 AM CDT FRI SEP 18 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 432 AM CDT FRI SEP 18 2015
AT THE SURFACE THIS MORNING...THE LOW LEVEL FRONTAL BOUNDARY HAS
PUSHED WELL SOUTH OF THE AREA...BUT MID LEVEL FRONT REMAINS LOCKED
FROM NEBRASKA PANHANDLE ACROSS THE CWA. HAD CLEARED ENOUGH EARLIER
WITH DIMINISHED NORTHERLY WINDS TO ALLOW TEMPS INTO THE UPPER 40S TO
LOWER 50S IN ALL BUT FAR SOUTH...AND DEWPOINTS TO FALL TOWARD 40 TO
45 IN SIMILAR AREAS. THE LARGER SCALE FEATURES IMPACTING THE
NORTHERN PLAINS ARE THE MAIN UPPER TROUGH PUSHING ACROSS WYOMING...
JET DIGGING AROUND THE BASE OF THE TROUGH TOWARD NORTHERN
COLORADO/SOUTHERN WYOMING...AND SECONDARY JET WITH LEADING NORTHERN
STREAM TROUGH FROM THE NORTHERN PLAINS TOWARD SOUTHWEST ONTARIO.
INITIAL PRECIPITATION ACROSS SOUTH CENTRAL SD AT 08Z HAS BEEN
ATTEMPTING TO STREAM NORTHEAST ALONG MID LEVEL BOUNDARY...BUT THE
DRIER LOW LEVEL AIR IN PLACE HAS BEEN CHALLENGING THE APPROACH
ACROSS SOUTHEAST SOUTH DAKOTA. WILL CONTINUE TO BE AN ISSUE WITH
SPREAD THROUGH EARLY MORNING...BUT DID FIND A NEED TO SPEED UP THE
SPREAD A BIT OVER EARLIER FORECAST...WHICH LOOKS TO HEAD LARGELY
ALONG/SOUTH OF I 90 IN MUCH OF THE AREA. PRECIP BASED A BIT LOWER IN
THE FRONTAL REALM SHOULD START TO POP UP PER ALMOST ALL MODEL
SOLUTIONS EARLY THIS MORNING TOWARD I 80 IN NEBRASKA WHERE CAN SEE
GATHERING MOISTURE IN THE FORM OF STRATUS BAND. AS THIS AREA OF
SHOWERS AND STORMS ENHANCES WITH APPROACH OF LARGER SCALE FORCING.
SOME HIGHER BASED INSTABILITY PROFILES SHOW WEAK INSTABILITY ABOVE
775 HPA CREEPING TOWARD THE LOWER MISSOURI VALLEY AND PARTS OF NW
IA...AND HAVE ADDED IN ISOLATED THUNDER. FAIRLY STRONG DYNAMICS LOOK
TO TAKE DIRECT AIM ACROSS THE FSD CWA FROM VERY LATE MORNING IN THE
FAR WEST...SPREADING ACROSS THE AREA THROUGH THE AFTERNOON...
ESPECIALLY STRONG WITH PV ADVECTION. MODELS SIMILAR IN DEVELOPING
ANTICYCLONICALLY CURVED OUTFLOW JET THROUGH MIDDAY FROM NORTHERN
MINNESOTA TO NORTHEAST SOUTH DAKOTA... INDICATIVE OF DECENT LATENT
HEAT RELEASE IN THE FRONTAL ZONE. CONFIDENCE IN PRECIPITATION IS
FAIRLY HIGH...AND HAVE RAISED THE POPS IN THE MID LEVEL FRONTAL ZONE
ACROSS THE MID/NORTH CWA A BIT MORE. ALSO...DURING THE AFTERNOON
CLOSER TO THE CORE OF THE UPPER WAVE WHERE TEMPS ALOFT ARE A BIT
COOLER...EXPERIMENTAL HRRR AND A COUPLE OTHER OF CAMS INDICATED
DEVELOPMENT OF SHOWERY AREA ACROSS CENTRAL SD WHICH ROTATES EASTWARD
WITH SOME AT LEAST WEAK INSTABILITY AND POTENTIAL FOR A FEW 50 DBZ
CORES...SUGGESTING A LOWER END THUNDER THREAT AS WELL. THIS AREA
SHOULD BE SOMEWHAT MORE LIMITED TO AREAS WEST OF THE JAMES RIVER
DURING THE MIDDAY/AFTERNOON HOURS. IF COULD MANAGE TO GET A BIT MORE
DIURNAL SUPPORT TO HEATING...COULD HAVE ENOUGH INSTABILITY TO
PERHAPS SEE AN OUTSIDE THREAT OF SOME VERY SMALL HAIL IN THE LOWER
BRULE AREA DURING THE EARLY TO MID AFTERNOON. HOWEVER...AT THIS TIME
APPEARS THAT ABUNDANCE OF CLOUDS AND THE PRESENCE OF PRECIP WILL
HOLD BACK HIGHS ENOUGH...MAINLY UPPER 50S TO MID 60S ACROSS THE AREA.
SHORT WAVELENGTH OF THE FEATURE COMPLICATES THOUGHTS OF KEEPING A
BIT MORE EXTENDED MENTION OF PRECIP CHANCE...AS WOULD TEND TO FOCUS
A MUCH GREATER PORTION OF THE PRECIP AHEAD OF TROUGH AXIS WHICH IS
THROUGH ALL BUT THE FAR EAST BY 00Z. HOWEVER...WITH CHANCE FOR A BIT
OF PRECIP IN DEFORMATION NORTH OF AXIS AND AT THIS TIME...WILL ALSO
INTRODUCE TRAILING SMALL BAND OF LOWER POPS...BUT SHOULD BE QUICKLY
DISSIPATING WITH THE OVERWHELMING LARGE SCALE TREND TO SUBSIDENCE
AND DRYING...AND THUS PRECIP SHOULD NOT TRAVERSE MUCH REAL ESTATE
BEFORE FADING AWAY. WINDS SHOULD ALSO WORK TOWARD DIMINISHING... AND
WITH CLEARING...WILL SEE A FEW NEAR 40 READINGS INTO THE NORTHERN
CWA...WITH MID 40S SOUTHEAST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 432 AM CDT FRI SEP 18 2015
SATURDAY AND SUNDAY LOOK DRY AND QUIET. HIGH PRESSURE ON SATURDAY
MORNING WILL DRIFT SOUTHEAST THROUGH THE DAY...ALLOWING WINDS TO
BACK AND TURN A BIT MORE SOUTHERLY. EVEN WITH ABUNDANT SUNSHINE THE
COOL ENVIRONMENT WILL LIKELY ONLY SUPPORT HIGH TEMPERATURES IN THE
MID 60S TO LOWER 70S.
THE SOUTHERLY GRADIENT INCREASES A BIT SATURDAY NIGHT INTO SUNDAY
WHICH WILL BRING MILDER LOWS ON SUNDAY MORNING...MAINLY UPPER 40S TO
LOWER 50S AND WARMER HIGHS...MOSTLY MID 70S.
IN THE OUTER PERIODS(MONDAY THROUGH THURSDAY)...MODELS STILL IN
PRETTY GOOD AGREEMENT BRINGING FLAT RIDGING INTO THE AREA ON MONDAY
THEN GRADUALLY BUILDING THE RIDGE BEFORE SWINGING A PRETTY STRONG
WAVE INTO THE AREA WEDNESDAY INTO THURSDAY. TIMING OF THIS WAVE OF
COURSE A BIT DIFFERENT FROM MODEL TO MODEL BUT EACH MODEL DOES HAVE
THIS ENERGY WORKING INTO THE AREA OVER THAT 48 HOUR PERIOD. PLUS THE
CANADIAN AND ECMWF HINT AT THE WAVE COMING OUT IN A COUPLE OF PIECES
WHILE THE GFS IS MORE COMPACT AND COMES OUT IN ONE STRONG PIECE.
SO...LOOKING AT DRY CONDITIONS ON MONDAY AND TUESDAY WITH GRADUALLY
INCREASING CHANCES WEDNESDAY INTO THURSDAY. AT THIS TIME WOULD
PINPOINT WEDNESDAY NIGHT AS THE HIGHEST PROBABILITY OF SHOWERS AND
THUNDERSTORMS. TOO TOUGH TO CALL ON TIMING RIGHT NOW. WILL ALSO NEED
TO KEEP AN EYE OUT FOR THE POTENTIAL FOR SEVERE WEATHER WITH THIS
ACTIVITY. OTHERWISE TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL
WITH HIGHS IN THE 70S TO MID 80S AND LOWS IN THE MID 50S TO LOWER
60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 654 AM CDT FRI SEP 18 2015
FOR THE MOST PART...EXPECT VFR CEILINGS TO ACCOMPANY LIGHT BANDED
PRECIPITATION THROUGH THE DAY. COULD SEE A LITTLE LOWER CEILINGS
INTO MVFR RANGE FOR BRIEF TIMES...BUT TOO DIFFICULT TO TIME ANY
GREATER THREAT AND THUS NOT OPTIMAL TO MENTION AT THIS TIME. COULD
BE A LITTLE THUNDER TOWARD KSUX DURING THE AFTERNOON...AGAIN TOO
LOW A PROBABILITY TO MENTION IN THE TAF.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN
LONG TERM...08
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
212 PM MDT FRI SEP 18 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 208 PM MDT FRI SEP 18 2015
...COOLER WEATHER CONTINUES ON SATURDAY...
STRETCH OF BEAUTIFUL FALL-LIKE WEATHER SHOULD CONTINUE ON
SATURDAY AS HIGH PRESSURE DOMINATES AND DRY WESTERLY FLOW
PERSISTS. UPSLOPE REGIME OVER THE PLAINS WILL ALLOW FOR ANOTHER
DAY OF SEASONABLE TEMPS ON SATURDAY.
HIGH RES MODELS INCLUDING THE HRRR CONTINUE TO INDICATE SOME
ISOLD SHOWER OR TS DEVELOPING LATE THIS AFTERNOON OVER NRN TELLER
COUNTY. THERE IS SOME CU OVER THAT AREA THIS AFTERNOON SO CANNOT
RULE IT OUT...AND WILL LEAVE SOME LOW POPS OVER THE PIKES PEAK
REGION AND ALSO OVER THE HYR TRRN IN NRN FREMONT COUNTY AND
MOSQUITO RANGE THRU THIS EVENING. HAVE TRIMMED BACK POPS ELSEWHERE
SINCE THE PROBABILITY LOOKS TOO LOW OVER THE ERN RANGES AND
CENTRAL MTS. ANYTHING THAT GETS GOING LATER TODAY SHOULD WIND DOWN
THIS EVE. THE HRRR INDICATES CONVECTION DRIFTING NWD TONIGHT...SO
MAY BE ABLE TO PULL POPS OUT COMPLETELY IF THINGS DON`T DEVELOP BY
EARLY EVE.
OVERNIGHT...WILL BE COOL WITH CLEARING SKIES AND WINDS DIMINISHING.
SOME LOWS IN THE UPR 40S POSSIBLE OVER THE PLAINS. A FEW AREAS OF
LOWER CLOUDS WILL BE POSSIBLE BUT SHOULD NOT BE TOO EXTENSIVE.
SATURDAY...FAIRLY SIMILAR TEMPS EXPECTED AS THE COOLER AIR REMAINS
WITH US...AND SFC WINDS SHIFT AROUND TO THE SE. SHOULD TOP OUT
AROUND 80 DEGREES FOR THE PLAINS...WHILE THE MTS AND HIGH VALLEYS
REMAIN IN THE 60S TO LOWER 70S. A SHORT WAVE WILL MOVE THROUGH THE
CENTRAL ROCKIES IN THE AFTERNOON...AND THIS COULD SPARK A FEW
SHOWERS OR STORMS MAINLY OVER THE HIGHER TRRN LATE IN THE
AFTERNOON...BUT NOT EXPECTING ANYTHING TOO WIDESPREAD OR HEAVY.
SHOULD BE A RATHER PLEASANT FALL-LIKE DAY ACROSS THE CWA. ROSE
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 208 PM MDT FRI SEP 18 2015
A SHORTWAVE TROF MOVING THRU THE AREA SAT NIGHT MAY BRING SOME ISOLD
PCPN TO LOCATIONS FROM THE ERN MTNS TO THE ERN BORDER...WHICH SHOULD
END TOWARD SUN MORNING. AN UPR RIDGE WL BUILD OVR THE AREA FOR SUN
AND MON WITH DRY WX EXPECTED AND ABOVE AVERAGE HIGH TEMPS.
ON TUE AN UPR TROF IS EXPECTED TO MOVE OVR SRN CA AND THE SW FLOW
ALOFT AHEAD OF THIS SYSTEM WL BRING AN INCREASE IN MSTR AND A CHANCE
FOR PCPN TO MAINLY THE SW CO MTNS LATE IN THE AFTERNOON. THE ECMWF
IS A LITTLE SLOWER BRINGING THE MSTR INTO THE AREA THAN THE GFS.
TUE NIGHT AND EARLY WED A SHORTWAVE TROF MOVES ACRS CO AND WL HAVE
THE POTENTIAL TO BRING ISOLD TO SCT PCPN TO MUCH OF THE FORECAST
AREA. THE ECMWF SHOWS A SLOWER MOVING TROF OVR THE AREA WED AND
INTO THE FIRST HALF OF THU...WITH ISOLD TO SCT PCPN CHANCES FOR MUCH
OF THE AREA. LOW LEVEL UPSLOPE FLOW IS EXPECTED ON THU AND THERE
MAY BE SOME SCT PCPN OVR AND NR THE MTNS AREAS. AN UPR RIDGE IS
EXPECTED OVR THE AREA ON FRI. THE GFS SHOWS A MONSOON MSTR TAP INTO
THE AREA FRI...WHILE THE ECMWF IS DRIER. SO THERE MAY BE SOME ISOLD
TO SCT PCPN CHANCES ON FRI. IT GENERALLY LOOKS LIKE HIGH TEMPS TUE
THRU FRI WL BE ABOVE AVERAGE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 208 PM MDT FRI SEP 18 2015
WINDS WILL CONTINUE VEERING TO AN EASTERLY DIRECTION THIS EVENING
THROUGH SAT MORNING OVER THE CO PLAINS...BUT WINDS SHOULD ALSO BE
ON THE LIGHT SIDE. A FEW AREAS OF MVFR CIGS WILL BE POSSIBLE ALONG
THE I-25 CORRIDOR OVERNIGHT INTO SAT MORNING...BUT SHOULD NOT HAVE A
SIGNIFICANT IMPACT ON THE TERMINALS. RISK OF TS SHOULD REMAIN LOW
THROUGH SAT AFTERNOON...BUT COULD SEE A LOW RISK OF TS DEVELOP BY
00Z SUN...ESPECIALLY AT KCOS. ROSE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ROSE
LONG TERM...28
AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS NEW YORK NY
419 PM EDT FRI SEP 18 2015
.SYNOPSIS...
HIGH PRESSURE WILL GRADUALLY SLIDE EASTWARD THROUGH SATURDAY.
A COLD FRONT WILL MOVES THROUGH LATE SATURDAY NIGHT AND
SUNDAY MORNING. HIGH PRESSURE WILL THEN BUILD TO THE NORTH EARLY
NEXT WEEK...AND THEN TO THE NORTHEAST INTO THE MIDDLE OF THE
WEEK...WHILE LOW PRESSURE MEANDERS OFF THE SOUTHEAST COAST.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE HIGH WILL SLIDE E AND WEAKEN AS A COLD FRONT APPROACHES FROM
THE WEST...AND AS LOW PRESSURE SLOWLY MOVES UP THE COAST.
SKIES WILL BE CLEAR TONIGHT...AND WITH LIGHT ONSHORE FLOW
CONTINUING...SHOULD SEE DEVELOPMENT OF FOG MAINLY AWAY FROM NYC
LATE TONIGHT INTO EARLY SAT MORNING. LOWS IN THE VALLEYS OF ORANGE
COUNTY AND THE LONG ISLAND PINE BARRENS WILL BE 55-60...WITH 60S
ELSEWHERE. KEPT LOWS AROUND 60 ACROSS THE INTERIOR DESPITE
AFTERNOON DEWPOINTS IN THE MID 50S SINCE AIR MASS WILL BE SLOWLY
MOISTENING TONIGHT IN THE ONSHORE FLOW.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
THE 12Z NAM AND NOW 12Z RAP ARE INDICATING AREA OF ISENTROPIC
LIFT...WITH CLOUDS/SHOWERS...MOVING UP THE NJ COAST TOWARD WRN
LONG ISLAND/CT AND SKIRTING NYC. NAM QPF OVERDONE BUT NOW THINK
THIS IS AT LEAST WORTH A SLIGHT CHANCE MENTION FOR SAT MORNING.
OTHERWISE...MOSTLY SUNNY SKIES ON SAT SHOULD LEAD TO HIGH TEMPS
A COUPLE DEG HIGHER THAN COMPOSITE MOS GUIDANCE AND SIMILAR TO
THOSE OF TODAY...WITH LOWER/MID 80S.
A COLD FRONT WILL BEGIN TO MOVE ACROSS LATE SAT NIGHT. LIFT LOOKS
WEAK AND DEEP MOISTURE IS LACKING...SO WILL CONTINUE TO CARRY
SLIGHT TO LOW CHANCE POP. LOWS WILL BE MAINLY IN THE 60S.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
NORTHERN STREAM SHORTWAVE PIVOTS THROUGH SOUTHEASTERN CANADA ON
SUNDAY/SUNDAY NIGHT. THEREAFTER MODELS IN FAIRLY GOOD AGREEMENT WITH
A SPLIT FLOW DEVELOPING FOR EARLY TO MID NEXT WEEK AS SHORTWAVE
ENERGY ENTERING THE PAC NW COAST DIGS THROUGH THE GREAT LAKES INTO
THE SE US EARLY NEXT WEEK. PART OF THIS ENERGY SEPARATES ITSELF FROM
THE NORTHERN STREAM AND CUTS OFF OVER THE SE US FOR THE MID TO LATE
WEEK PERIOD...WHILE THE REST SWINGS THROUGH THE NORTHEAST DURING THE
MIDWEEK PERIOD.
SOME UNCERTAINTY IN THE FORECAST LIES IN THE INTERACTION OF THE
DIGGING EASTERN TROUGH WITH PIECES OF SUB-TROPICAL ENERGY ROUNDING
DOMINANT ATLANTIC RIDGING...AND HOW CLOSE TO THE COAST THIS
MOISTURE/ENERGY MAY GET FOR MUCH OF THE WEEK.
IN TERMS OF SENSIBLE WEATHER...A MOISTURE STARVED COLD FRONT WITH
SHORTWAVE ENERGY WELL TO THE NW PASSES EAST OF THE REGION SUNDAY
MORNING. A FEW LINGERING SHOWERS POSSIBLE SUNDAY MORNING...OTHERWISE
A COOLER AND DRIER AIRMASS BEGINS ADVECTING INTO THE REGION ON
BREEZY NORTHERLY FLOW ON SUNDAY. TEMPS SUNDAY SHOULD BE NEAR
SEASONABLE.
AS HIGH PRESSURE CONTINUES TO BUILD THROUGH AND EAST OF NEW ENGLAND
EARLY TO MID NEXT WEEK...A BREEZY NE FLOW WILL PERSIST AND MAINTAIN
A MAINLY DRY BUT SEASONABLY COOL CANADIAN MARITIMES AIRMASS OVER THE
REGION. THE TIGHT GRADIENT WILL BE COURTESY OF A SERIES OF LOWS
DRIFTING NE WELL OFF THE EAST COAST. AS MENTIONED
BEFORE...UNCERTAINTY EXISTS ON EXACT EVOLUTION OF THESE OFFSHORE
LOW/S INTO MIDWEEK...BUT NHC SEES A MEDIUM POTENTIAL FOR SOME SORT
OF TROPICAL/SUB-TROPICAL DEVELOPMENT OVER THE NEXT 5 DAYS. THERE IS
CURRENTLY A SLIGHT POTENTIAL FOR THE REGION TO AFFECTED BY SOME
SHOWER ACTIVITY MIDWEEK AS THE EARLIER MENTIONED NORTHERN STREAM
SHORTWAVE APPROACHES/SWINGS THROUGH...BUT THIS WILL ULTIMATELY BE
DEPENDENT ON EVOLUTION OF THE OFFSHORE LOW PRESSURE/S AND STRENGTH
OF UPPER CONFLUENCE/SURFACE RIDGING OVER THE NE.
OTHERWISE...THE SAME MIDWEEK PATTERN COULD PERSIST THROUGH THE WEEK
IN THE CONTINUED SPLIT FLOW REGIME...WITH THE REGION IN BETWEEN
NORTHERN STREAM FLOW WELL TO THE NORTH...A BROAD CUTOFF LOW TO THE
SOUTH...AND DOMINANT OFFSHORE RIDGING TO THE SE.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
HIGH PRESSURE REMAINS OFFSHORE.
VFR TODAY. SEA BREEZES NOW THROUGH ALL BUT KSWF. EXPECT S-SSE
WINDS AROUND 10KT THIS AFTN...BCMG LIGHTER TOWARDS 00Z.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KLGA FCSTER COMMENTS: OCCASIONAL GUSTS 16-19KT POSSIBLE THIS AFTN.
KEWR FCSTER COMMENTS: OCCASIONAL GUSTS 16-19KT POSSIBLE THIS AFTN.
KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
.OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...
.SAT...VFR.
.SUN-TUE...MAINLY VFR. CHC SUB-VFR TUE. N-NE GUSTS 20-25KT.
POSSIBLE AT COASTAL TERMINALS.
.WED...VFR.
&&
.MARINE...
CONDITIONS ACROSS THE AREA WATERS WILL REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS THROUGH SATURDAY...AS HIGH PRESSURE MOVES
OFFSHORE.
SCA WIND GUSTS POSSIBLE SUNDAY AFTERNOON FOR ALL WATERS IN WAKE OF
COLD FRONTAL PASSAGE...BUT BETTER POTENTIAL FOR SCA DEVELOPS SUNDAY
NIGHT AND LIKELY THROUGH EARLY NEXT WEEK ESPECIALLY ON THE OCEAN
WITH DEVELOPMENT OF A PERSISTENT E/NE FLOW.
OCEAN SEAS COULD BUILD TO 6 TO 8 FT FOR EARLY NEXT WEEK...USUALLY
UNDER-PREDICTED IN WNA GUIDANCE. WINDS MAY ALSO GUST CLOSE TO 25 KT
DURING THIS TIME ACROSS ALL WATERS.
&&
.FIRE WEATHER...
FUEL MOISTURE LEVELS WILL LIKELY CONTINUE TO DECREASE THROUGH THE
WEEKEND WITH THE UNSEASONABLY WARM AND DRY WEATHER. CURRENTLY KBDI
VALUES ARE GREATER THAN 300 OVER A GOOD PORTION OF THE REGION.
DEPENDING ON COVERAGE OF LIGHT RAINFALL WITH COLD FRONTAL PASSAGE
SAT NIGHT/EARLY SUN...PREDECESSOR DRY CONDS WITH A GUSTY N FLOW
AND LOW RH VALUES MAY RESULT IN AN ENHANCED FIRE WEATHER THREAT ON
SUNDAY.
&&
.HYDROLOGY...
DRY CONDITIONS EXPECTED THROUGH SATURDAY WITH NO WIDESPREAD
SIGNIFICANT PRECIPITATION EXPECTED THROUGH NEXT WEEK.
&&
.TIDES/COASTAL FLOODING...
THERE IS THE POSSIBILITY FOR MINOR COASTAL FLOODING DURING THE
MON-FRI TIMEFRAME DUE TO THE FORECAST OF PROLONGED E-NE FLOW.
POTENTIAL FOR IMPACTS APPEARS LOW FOR MON...BUT MAY INCREASE IN
THE TYPICALLY VULNERABLE LOCALES FOR THE MID TO LATE WEEK PERIOD
WITH GRADAUALLY RISING ASTRONOMICAL HIGH TIDES.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GOODMAN/NV
NEAR TERM...GOODMAN
SHORT TERM...GOODMAN
LONG TERM...NV
AVIATION...JC
MARINE...GOODMAN/NV
FIRE WEATHER...NV
HYDROLOGY...GOODMAN/NV
TIDES/COASTAL FLOODING...NV
AREA FORECAST DISCUSSION
NWS NEW YORK NY
402 PM EDT FRI SEP 18 2015
.SYNOPSIS...
HIGH PRESSURE WILL GRADUALLY SLIDE EASTWARD THROUGH SATURDAY.
A COLD FRONT WILL MOVES THROUGH LATE SATURDAY NIGHT AND
SUNDAY MORNING. HIGH PRESSURE WILL THEN BUILD TO THE NORTH EARLY
NEXT WEEK...AND THEN TO THE NORTHEAST INTO THE MIDDLE OF THE
WEEK...WHILE LOW PRESSURE MEANDERS OFF THE SOUTHEAST COAST.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE HIGH WILL SLIDE E AND WEAKEN AS A COLD FRONT APPROACHES FROM
THE WEST...AND AS LOW PRESSURE SLOWLY MOVES UP THE COAST.
SKIES WILL BE CLEAR TONIGHT...AND WITH LIGHT ONSHORE FLOW
CONTINUING...SHOULD SEE DEVELOPMENT OF FOG MAINLY AWAY FROM NYC
LATE TONIGHT INTO EARLY SAT MORNING. LOWS IN THE VALLEYS OF ORANGE
COUNTY AND THE LONG ISLAND PINE BARRENS WILL BE 55-60...WITH 60S
ELSEWHERE. KEPT LOWS AROUND 60 ACROSS THE INTERIOR DESPITE
AFTERNOON DEWPOINTS IN THE MID 50S SINCE AIR MASS WILL BE SLOWLY
MOISTENING TONIGHT IN THE ONSHORE FLOW.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
THE 12Z NAM AND NOW 12Z RAP ARE INDICATING AREA OF ISENTROPIC
LIFT...WITH CLOUDS/SHOWERS...MOVING UP THE NJ COAST TOWARD WRN
LONG ISLAND/CT AND SKIRTING NYC. NAM QPF OVERDONE BUT NOW THINK
THIS IS AT LEAST WORTH A SLIGHT CHANCE MENTION FOR SAT MORNING.
OTHERWISE...MOSTLY SUNNY SKIES ON SAT SHOULD LEAD TO HIGH TEMPS
A COUPLE DEG HIGHER THAN COMPOSITE MOS GUIDANCE AND SIMILAR TO
THOSE OF TODAY...WITH LOWER/MID 80S.
A COLD FRONT WILL BEGIN TO MOVE ACROSS LATE SAT NIGHT. LIFT LOOKS
WEAK AND DEEP MOISTURE IS LACKING...SO WILL CONTINUE TO CARRY
SLIGHT TO LOW CHANCE POP. LOWS WILL BE MAINLY IN THE 60S.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
NORTHERN STREAM SHORTWAVE PIVOTS THROUGH SOUTHEASTERN CANADA ON
SUNDAY/SUNDAY NIGHT. THEREAFTER MODELS IN FAIRLY GOOD AGREEMENT WITH
A SPLIT FLOW DEVELOPING FOR EARLY TO MID NEXT WEEK AS SHORTWAVE
ENERGY ENTERING THE PAC NW COAST DIGS THROUGH THE GREAT LAKES INTO
THE SE US EARLY NEXT WEEK. PART OF THIS ENERGY SEPARATES ITSELF FROM
THE NORTHERN STREAM AND CUTS OFF OVER THE SE US FOR THE MID TO LATE
WEEK PERIOD...WHILE THE REST SWINGS THROUGH THE NORTHEAST DURING THE
MIDWEEK PERIOD.
SOME UNCERTAINTY IN THE FORECAST LIES IN THE INTERACTION OF THE
DIGGING EASTERN TROUGH WITH PIECES OF SUB-TROPICAL ENERGY ROUNDING
DOMINANT ATLANTIC RIDGING...AND HOW CLOSE TO THE COAST THIS
MOISTURE/ENERGY MAY GET FOR MUCH OF THE WEEK.
IN TERMS OF SENSIBLE WEATHER...A MOISTURE STARVED COLD FRONT WITH
SHORTWAVE ENERGY WELL TO THE NW PASSES EAST OF THE REGION SUNDAY
MORNING. A FEW LINGERING SHOWERS POSSIBLE SUNDAY MORNING...OTHERWISE
A COOLER AND DRIER AIRMASS BEGINS ADVECTING INTO THE REGION ON
BREEZY NORTHERLY FLOW ON SUNDAY. TEMPS SUNDAY SHOULD BE NEAR
SEASONABLE.
AS HIGH PRESSURE CONTINUES TO BUILD THROUGH AND EAST OF NEW ENGLAND
EARLY TO MID NEXT WEEK...A BREEZY NE FLOW WILL PERSIST AND MAINTAIN
A MAINLY DRY BUT SEASONABLY COOL CANADIAN MARITIMES AIRMASS OVER THE
REGION. THE TIGHT GRADIENT WILL BE COURTESY OF A SERIES OF LOWS
DRIFTING NE WELL OFF THE EAST COAST. AS MENTIONED
BEFORE...UNCERTAINTY EXISTS ON EXACT EVOLUTION OF THESE OFFSHORE
LOW/S INTO MIDWEEK...BUT NHC SEES A MEDIUM POTENTIAL FOR SOME SORT
OF TROPICAL/SUB-TROPICAL DEVELOPMENT OVER THE NEXT 5 DAYS. THERE IS
CURRENTLY A SLIGHT POTENTIAL FOR THE REGION TO AFFECTED BY SOME
SHOWER ACTIVITY MIDWEEK AS THE EARLIER MENTIONED NORTHERN STREAM
SHORTWAVE APPROACHES/SWINGS THROUGH...BUT THIS WILL ULTIMATELY BE
DEPENDENT ON EVOLUTION OF THE OFFSHORE LOW PRESSURE/S AND STRENGTH
OF UPPER CONFLUENCE/SURFACE RIDGING OVER THE NE.
OTHERWISE...THE SAME MIDWEEK PATTERN COULD PERSIST THROUGH THE WEEK
IN THE CONTINUED SPLIT FLOW REGIME...WITH THE REGION IN BETWEEN
NORTHERN STREAM FLOW WELL TO THE NORTH...A BROAD CUTOFF LOW TO THE
SOUTH...AND DOMINANT OFFSHORE RIDGING TO THE SE.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
HIGH PRESSURE REMAINS OFFSHORE.
VFR TODAY. SEA BREEZES NOW THROUGH ALL BUT KSWF. EXPECT S-SSE
WINDS AROUND 10KT THIS AFTN...BCMG LIGHTER TOWARDS 00Z.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KLGA FCSTER COMMENTS: OCCASIONAL GUSTS 16-19KT POSSIBLE THIS AFTN.
KEWR FCSTER COMMENTS: OCCASIONAL GUSTS 16-19KT POSSIBLE THIS AFTN.
KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
.OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...
.SAT...VFR.
.SUN-TUE...MAINLY VFR. CHC SUB-VFR TUE. N-NE GUSTS 20-25KT.
POSSIBLE AT COASTAL TERMINALS.
.WED...VFR.
&&
.MARINE...
CONDITIONS ACROSS THE AREA WATERS WILL REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS THROUGH SATURDAY...AS HIGH PRESSURE MOVES
OFFSHORE.
SCA WIND GUSTS POSSIBLE SUNDAY AFTERNOON FOR ALL WATERS IN WAKE OF
COLD FRONTAL PASSAGE...BUT BETTER POTENTIAL FOR SCA DEVELOPS SUNDAY
NIGHT AND LIKELY THROUGH EARLY NEXT WEEK ESPECIALLY ON THE OCEAN
WITH DEVELOPMENT OF A PERSISTENT E/NE FLOW.
OCEAN SEAS COULD BUILD TO 6 TO 8 FT FOR EARLY NEXT WEEK...USUALLY
UNDER-PREDICTED IN WNA GUIDANCE. WINDS MAY ALSO GUST CLOSE TO 25 KT
DURING THIS TIME ACROSS ALL WATERS.
&&
.FIRE WEATHER...
FUEL MOISTURE LEVELS WILL LIKELY CONTINUE TO DECREASE THROUGH THE
WEEKEND WITH THE UNSEASONABLY WARM AND DRY WEATHER. CURRENTLY KBDI
VALUES ARE GREATER THAN 300 OVER A GOOD PORTION OF THE REGION.
DEPENDING ON COVERAGE OF LIGHT RAINFALL WITH COLD FRONTAL PASSAGE
SAT NIGHT/EARLY SUN...PREDECESSOR DRY CONDS AND A GUSTY N FLOW AND
LOW RH VALUES MAY RESULT IN AN ENHANCED FIRE WEATHER THREAT ON
SUNDAY.
&&
.HYDROLOGY...
DRY CONDITIONS EXPECTED THROUGH SATURDAY WITH NO WIDESPREAD
SIGNIFICANT PRECIPITATION EXPECTED THROUGH NEXT WEEK.
&&
.TIDES/COASTAL FLOODING...
THERE IS THE POSSIBILITY FOR MINOR COASTAL FLOODING FROM MONDAY INTO
FRIDAY WITH THE FORECAST OF PROLONGED E-NE FLOW. GIVEN THE
UNCERTAINTY IN THIS TIME FRAME...IT IS TOO EARLY TO SPECULATE ON
WHAT AREAS...IF ANY ARE AT THE GREATEST THREAT FOR MINOR COASTAL
FLOODING.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GOODMAN/NV
NEAR TERM...GOODMAN
SHORT TERM...GOODMAN
LONG TERM...NV
AVIATION...JC
MARINE...GOODMAN/NV
FIRE WEATHER...NV
HYDROLOGY...GOODMAN/NV
TIDES/COASTAL FLOODING...NV
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
259 PM CDT FRI SEP 18 2015
.SHORT TERM...
211 PM CDT
THROUGH TONIGHT...
IN ADDITION TO SOME LIGHT RAIN/DRIZZLE FARTHER NORTH...WE ARE
BEGINNING TO SEE SCATTERED SHOWER DEVELOPMENT FARTHER NORTH INTO
OUR AREA THIS AFTERNOON AS THE AREA BEGINS TO FEEL MORE OF THE
LIFT FROM A PAIR OF LEADING SHORTWAVES AHEAD OF A VERY WELL
DEFINED UPPER LEVEL TROUGH AND CLOSED CIRCULATION MOVING EAST
THROUGH THE DAKOTAS. THE FIRST OF THESE WAVES IS PUSHING INTO WEST
CENTRAL ILLINOIS WHERE MORE ORGANIZED THUNDERSTORM ACTIVITY IS
FOCUSED. THESE ARE IN AREAS WHERE EARLIER BREAKS IN LOWER LEVEL
STRATUS HAVE ENABLED GREATER DESTABILIZATION. A STATIONARY
FRONTAL BOUNDARY REMAINS DRAPED ACROSS THE WESTERN CWA. ADDITIONAL
ELEVATED THUNDERSTORMS THROUGH SOUTHERN IOWA AND EXTENDING TO NEAR
THE MISSISSIPPI RIVER IN FAR EASTERN IOWA AHEAD OF THESE
ADDITIONAL LEADING SHORTWAVES.
EXPECT SHOWERS AND ISOLATED THUNDERSTORMS TO INCREASE IN COVERAGE
INTO NORTHEAST ILLINOIS AND NORTHWEST INDIANA. AS THE AFTERNOON
CONTINUES. WITH THE THICK CLOUD COVER FARTHER NORTH...FEEL THE MORE
ACTIVE STORMS WILL BE CONFINED ALONG AND SOUTH OF INTERSTATE 80
WHERE LOCALLY HEAVY RAINFALL IS EXPECTED AND STORM MOTION IS NOT
SUPER FAST. A SEVERE THREAT EXISTS AS WELL DUE TO MODEST MID LEVEL
LAPSE RATES (NEAR 7 DEG/KM ON THE KDVN MORNING SOUNDING)...THOUGH
SHEAR HAS DECREASED SOMEWHAT LOWER THAN WHAT WAS DEPICTED EARLIER
TODAY ON THE RAP SPC MESOANALYSIS. IT IS FORECAST TO INCREASE
AGAIN AS THE AFTERNOON CONTINUES...KEEPING SOME THREAT FOR GUSTY
WINDS AND HAIL MAINLY FOR OUR WESTERN AND SOUTHERN AREAS.
WIDESPREAD SEVERE WEATHER WITH THIS WAVE IS NOT ANTICIPATED AS
SHOWERS/STORMS TO THE NORTH WILL BE ELEVATED.
IT LOOKS LIKE AFTER THIS ACTIVITY MOVES THROUGH...THERE COULD BE A
SHORT BREAK BEFORE THE MORE ORGANIZED ACTIVITY ASSOCIATED WITH THE
UPPER TROUGH MOVES THROUGH LATER THIS EVENING AND TONIGHT. THIS
BREAK...IF IT OCCURS...WOULD LAST THE LONGEST FOR POINTS SOUTH AND
EAST ABD THERE MAY NOT BE MUCH OF A BREAK IN AREAS NORTH AND WEST.
THE TIMING ON THIS ROUND OF MORE ORGANIZED THUNDERSTORM ACTIVITY IS
AFTER 7-8 PM IN THE WEST...AND AFTER 9 PM CLOSER TO CHICAGO. CURRENT
SHORT TERM RUNS OF THE HRRR/RAP SUGGEST IT COULD BE SLIGHTLY LATER
THAN THAT FOR AREAS SOUTH AND EAST OF I-57. THE BEST COMBINATION OF
UPPER Q-G FORCING FROM THE UPPER TROUGH AND LOWER FRONTOGENETICAL
FORCING ON THE BACK SIDE OF THE SURFACE LOW IS ALONG AND NORTH OF I-
80 FOR THIS SECOND ROUND OF STORMS...WHICH IS MAXIMIZED IN THE LATE
EVENING AND EARLY MORNING HOURS WHEN THE PERIOD OF HIGHEST CONCERN
FOR HEAVY RAIN EXISTS. MANY AREAS WILL SEE HEAVY RAIN ACTIVITY WITH
THIS WAVE...BUT HAVE HELD ONTO THE FLASH FLOOD WATCH FOR THE CURRENT
AREAS THAT RECEIVED THE HEAVIEST RAINS LAST NIGHT. LEAST FAVORED
AREAS ARE SOUTH AND EAST OF INTERSTATE 57 AND HAVE PLACED HIGHEST
QPF IN THE MOST FAVORED FORCING LOCATIONS IN NORTH AND NORTH CENTRAL
ILLINOIS. MOST UNSTABLE CAPE IN EXCESS OF 1000 J/KG AND EFFECTIVE
SHEAR OF 40+ KT SUGGEST THE POTENTIAL FOR SEVERE HAIL AND LOCALLY
STRONG WINDS AGAIN WITH THE LATER EVENING STORMS...WITH THE WIND
THREAT CONTINGENT ON STORMS EVOLVING INTO A LINE.
THE SURFACE LOW CONTINUES DEEPENING OVERNIGHT AS IT MOVES NORTHEASTWARD.
THE COLD FRONT SPREADS IN FROM NORTHWEST TO SOUTHEAST WHICH
SHOULD EASE SHOWER/STORM THREAT OVERNIGHT. BRISK NORTHWEST WINDS
WILL USHER IN A MUCH COOLER AND DRIER AIRMASS.
KMD
&&
.LONG TERM...
236 PM CDT
SATURDAY THROUGH FRIDAY...
MID-LEVEL SHORT WAVE TROUGH AND SURFACE FRONTAL SYSTEM ASSOCIATED
WITH SHORT TERM RAIN/THUNDERSTORMS WILL BE MOVING OUT OF THE
FORECAST AREA EARLY SATURDAY MORNING. LINGERING LOW LEVEL MOISTURE
BEHIND THE FRONT AND FORCING ASSOCIATED WITH THE PASSAGE OF THE
MID-LEVEL TROUGH MAY ALLOW A FEW SHOWERS/SPRINKLES TO PERSIST
MAINLY ACROSS THE FAR SOUTHEAST PARTS OF THE CWA PAST
SUNRISE...THOUGH BREEZY NORTH WINDS QUICKLY ADVECT DRIER AIR INTO
THE REGION PER FORECAST SOUNDINGS ALLOWING A QUICK END TO ANY
PRECIP AND DECREASING CLOUD COVER THROUGH THE LATE MORNING HOURS.
WHILE SUNSHINE RETURNS...COOLER TEMPS IN THE UPPER 60S/AROUND 70
AND BREEZY NORTH WINDS GUSTING AROUND 20 MPH ESPECIALLY IN THE
MORNING WILL MAKE FOR AN AUTUMN FEEL. SURFACE HIGH PRESSURE BUILDS
ACROSS THE AREA SATURDAY NIGHT...WITH CLEAR SKIES...LIGHT/CALM
WINDS AND COOL/DRY AIR MASS...WILL LIKELY PRODUCE SOME CHILLY LOW-
MID 40S IN COOLER SPOTS AND HAVE UNDERCUT GUIDANCE/BLENDED TOWARD
COOLER MAV MINS. BREEZY NORTH WINDS GUSTING 20-25 MPH SATURDAY
MORNING/EARLY AFTERNOON WILL QUICKLY DIMINISH DURING THE
AFTERNOON.
REST OF EXTENDED PERIOD LOOKS TO REMAIN VERY QUIET...WITH A
GRADUAL MODERATING TREND THROUGH MID/LATE WEEK AS UPPER RIDGE
DEVELOPS OVER THE SOUTHWESTERN CONUS...AND EVENTUALLY BUILDS
NORTHEASTWARD INTO THE GREAT LAKES REGION BY MID-WEEK. SURFACE
HIGH SLIDES EAST OF THE AREA BY LATER SUNDAY...THOUGH WESTERN
PERIPHERY OF SFC RIDGE AXIS LINGERS ACROSS THE REGION FOR A FEW
DAYS. THIS SETS UP A FAIRLY PLEASANT PERIOD OF MILD DAYS WITH
TEMPS SLOWLY WARMING FROM THE LOW 70S (UPPER 60S NEAR THE LAKE) TO
75-80/LOW 80S RANGE BY THE LATTER HALF OF THE WEEK...WITH LOWS IN
THE 40S/50S MODERATING BACK INTO THE 50S/NEAR 60.
NO REAL THREAT OF ORGANIZED RAIN APPEARS AT THIS TIME BEYOND
SATURDAY MORNING...UNTIL PERHAPS LATE THURSDAY OR FRIDAY AS A WEAK
COLD FRONT SETTLES ACROSS THE UPPER MISSISSIPPI/WESTERN LAKES
REGION. SOME MODEL SOLUTIONS KEEP THIS FRONT NORTH OF THE AREA
HOWEVER...OR DONT DEVELOP SIGNIFICANT PRECIP ALONG IT...WITH THE
UPPER RIDGE RE-BUILDING INTO NEXT WEEKEND. THUS HAVE HELD FORECAST
DRY THROUGH FRI AND GIVEN JUST A NOD TO SLIGHTLY COOLER TEMPS
ACROSS THE NORTHERN PART OF THE FORECAST AREA BY FRIDAY PER
BLENDED GUIDANCE.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* MVFR CIGS INTO THE EARLY AFTN.
* WIND SHIFT TO NE THIS AFTN.
* SCT SHRA AND TSRA PSBL THIS AFTN WITH LAKE BREEZE...MORE
WIDESPREAD TSRA AND SHRA EXPECTED THIS EVENING AND OVERNIGHT.
* IFR CIGS AND GUSTY NW WINDS LATE TONIGHT INTO TOMORROW WITH
GUSTS ARND 25 KT.
* WINDS SHIFT TO NE ARND 10KT SATURDAY AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
A MESSY FORECAST IS UPON US. MVFR STRATUS IS SPREAD ACROSS MUCH OF
THE REGION AND IS SLOWLY LIFTING. LATEST MODEL ANALYSIS SHOWS
AREAS SOUTH OF I-80 ARE PRIMED FOR THUNDERSTORM DEVELOPMENT AND
THE STALLED FRONTAL BOUNDARY IS STILL LOCATED FROM WAUKEGAN
TO YORKVILLE TO FAR SOUTHEAST IOWA. EXPECTING THUNDERSTORMS TO
FORM SOUTH OF THE TERMINALS OVER THE NEXT COUPLE OF HOURS AND THEN
SHIFT NORTHEAST REACHING THE TERMINALS ARND 21Z.
GUIDANCE IS INDICATING A SLOWER SHIFT TO NE WINDS WITH WIND
SPEEDS ARND 7-8KT. DECIDED TO KEEP 9KT SINCE PREVIOUS MODEL RUNS
WERE SHOWING 10KT. PUSHED THE LAKE BREEZE TIMING BACK TO 21Z WHICH
IS SUPPORTED BY ALL LAKE FRONT BUOYS STILL SHOWING SOUTHWEST
WINDS.
A LOW PRESSURE SYSTEM CURRENTLY OVER THE CENTRAL PLAINS RACES OVER
NORTHERN IL THIS EVENING BRINGING MORE WIDESPREAD SHOWERS AND
STORMS. HEAVY RAIN IS POSSIBLE AT TIMES THIS EVENING WHICH COULD
RESULT IN MVFR VSBY. EXPECTING IFR CIGS TO MOVE IN BEHIND THE LOW
AND PERSIST INTO THE MORNING WINDS WILL BEGIN TURNING TO SE EARLY
THIS AFTN AND KEEP VEERING TO NW AND GUSTING TO 25KT LATE TONIGHT
INTO SATURDAY MORNING. SKIES BECOME VFR AS THE LOWER CIGS SHIFT
EAST WITH THE LOW AND WINDS WILL BECOME NE ARND 10KT SATURDAY
AFTN.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN WHEN MVFR CIGS WILL IMPROVE TO VFR.
* MEDIUM CONFIDENCE IN TIMING OF WIND SHIFT THIS AFTN AND IN
SHRA/TSRA ASSOCIATED WITH IT...LOW CONFIDENCE IN SEEING 10 KT.
* HIGH CONFIDENCE IN SHRA AND TSRA THIS EVENING AND TONIGHT.
* MEDIUM-HIGH CONFIDENCE IN IFR CIGS.
* MEDIUM CONFIDENCE IN TIMING OF NE WINDS SATURDAY AFTERNOON.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
* SATURDAY NIGHT...DRY/VFR.
* SUNDAY THRU THURSDAY...DRY/VFR. EASTERLY WINDS/LAKE BREEZES.
&&
.MARINE...
257 PM CDT
MAIN MARINE CONCERNS ARE IN THE FIRST 24-36 HOURS OF THE FORECAST
THIS AFTERNOON...WITH A PERIOD OF NORTH GALES LIKELY ON CENTRAL
AND SOUTHERN LAKE MICHIGAN SATURDAY MORNING.
A NEARLY STATIONARY COLD FRONT STRETCHED FROM LOW PRESSURE OVER
EASTERN CANADA...SOUTHWEST ACROSS LAKE MICHIGAN TO THE SOUTHERN
PLAINS. A SURFACE LOW PRESSURE WAVE WILL LIFT NORTHEAST ALONG THE
FRONT THIS EVENING...EVENTUALLY DEEPENING AS IT LIFTS NORTHEAST OF
THE LAKE EARLY SATURDAY AND PULLING THE COLD FRONT SOUTHEAST AND
CLEAR OF THE LAKE. AS THE LOW DEEPENS OFF TO THE NORTHEAST EARLY
SATURDAY...AND HIGH PRESSURE BEGINS TO BUILD EASTWARD ACROSS THE
PLAINS...THE COMBINATION OF A TIGHTENING SURFACE PRESSURE GRADIENT
AND LOW LEVEL COLD AIR ADVECTION IS EXPECTED TO LEAD TO A BRIEF
PERIOD OF 30-35 KT WINDS OVER THE LAKE. GALE FORCE WINDS APPEAR TO
BE MOST LIKELY ACROSS CENTRAL AND SOUTHERN LAKE MICHIGAN FROM THE
PREDAWN HOURS THROUGH MID-LATE MORNING SATURDAY. WINDS WILL THEN
QUICKLY DIMINISH LATER SATURDAY AFTERNOON AND NIGHT AS THE SURFACE
HIGH MOVES INTO THE REGION.
BEYOND SATURDAY...THE WEATHER PATTERN LOOKS TO REMAIN FAIRLY
QUIET WITH THE TRAILING WESTERN PERIPHERY OF THE SURFACE RIDGE
AXIS REMAINING OVER THE CENTRAL OR SOUTHERN PART OF THE
LAKE...WHILE AN AREA OF LOW PRESSURE PASSES WELL NORTH OF THE
LAKES THROUGH MID- WEEK. THIS WILL LIKELY RESULT IN MODEST SOUTH-
SOUTHWEST WINDS INCREASING A BIT ON THE NORTH END OF THE LAKE AND
PERHAPS GUSTING 15-20 KTS AT TIMES...WHILE REMAINING LIGHTER
FARTHER SOUTH.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022...7
PM FRIDAY TO 7 AM SATURDAY.
IN...NONE.
LM...GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...4 AM SATURDAY TO 1 PM SATURDAY.
&&
$$
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
237 PM CDT FRI SEP 18 2015
.SHORT TERM...
211 PM CDT
THROUGH TONIGHT...
IN ADDITION TO SOME LIGHT RAIN/DRIZZLE FARTHER NORTH...WE ARE
BEGINNING TO SEE SCATTERED SHOWER DEVELOPMENT FARTHER NORTH INTO
OUR AREA THIS AFTERNOON AS THE AREA BEGINS TO FEEL MORE OF THE
LIFT FROM A PAIR OF LEADING SHORTWAVES AHEAD OF A VERY WELL
DEFINED UPPER LEVEL TROUGH AND CLOSED CIRCULATION MOVING EAST
THROUGH THE DAKOTAS. THE FIRST OF THESE WAVES IS PUSHING INTO WEST
CENTRAL ILLINOIS WHERE MORE ORGANIZED THUNDERSTORM ACTIVITY IS
FOCUSED. THESE ARE IN AREAS WHERE EARLIER BREAKS IN LOWER LEVEL
STRATUS HAVE ENABLED GREATER DESTABILIZATION. A STATIONARY
FRONTAL BOUNDARY REMAINS DRAPED ACROSS THE WESTERN CWA. ADDITIONAL
ELEVATED THUNDERSTORMS THROUGH SOUTHERN IOWA AND EXTENDING TO NEAR
THE MISSISSIPPI RIVER IN FAR EASTERN IOWA AHEAD OF THESE
ADDITIONAL LEADING SHORTWAVES.
EXPECT SHOWERS AND ISOLATED THUNDERSTORMS TO INCREASE IN COVERAGE
INTO NORTHEAST ILLINOIS AND NORTHWEST INDIANA. AS THE AFTERNOON
CONTINUES. WITH THE THICK CLOUD COVER FARTHER NORTH...FEEL THE MORE
ACTIVE STORMS WILL BE CONFINED ALONG AND SOUTH OF INTERSTATE 80
WHERE LOCALLY HEAVY RAINFALL IS EXPECTED AND STORM MOTION IS NOT
SUPER FAST. A SEVERE THREAT EXISTS AS WELL DUE TO MODEST MID LEVEL
LAPSE RATES (NEAR 7 DEG/KM ON THE KDVN MORNING SOUNDING)...THOUGH
SHEAR HAS DECREASED SOMEWHAT LOWER THAN WHAT WAS DEPICTED EARLIER
TODAY ON THE RAP SPC MESOANALYSIS. IT IS FORECAST TO INCREASE
AGAIN AS THE AFTERNOON CONTINUES...KEEPING SOME THREAT FOR GUSTY
WINDS AND HAIL MAINLY FOR OUR WESTERN AND SOUTHERN AREAS.
WIDESPREAD SEVERE WEATHER WITH THIS WAVE IS NOT ANTICIPATED AS
SHOWERS/STORMS TO THE NORTH WILL BE ELEVATED.
IT LOOKS LIKE AFTER THIS ACTIVITY MOVES THROUGH...THERE COULD BE A
SHORT BREAK BEFORE THE MORE ORGANIZED ACTIVITY ASSOCIATED WITH THE
UPPER TROUGH MOVES THROUGH LATER THIS EVENING AND TONIGHT. THIS
BREAK...IF IT OCCURS...WOULD LAST THE LONGEST FOR POINTS SOUTH AND
EAST ABD THERE MAY NOT BE MUCH OF A BREAK IN AREAS NORTH AND WEST.
THE TIMING ON THIS ROUND OF MORE ORGANIZED THUNDERSTORM ACTIVITY IS
AFTER 7-8 PM IN THE WEST...AND AFTER 9 PM CLOSER TO CHICAGO. CURRENT
SHORT TERM RUNS OF THE HRRR/RAP SUGGEST IT COULD BE SLIGHTLY LATER
THAN THAT FOR AREAS SOUTH AND EAST OF I-57. THE BEST COMBINATION OF
UPPER Q-G FORCING FROM THE UPPER TROUGH AND LOWER FRONTOGENETICAL
FORCING ON THE BACK SIDE OF THE SURFACE LOW IS ALONG AND NORTH OF I-
80 FOR THIS SECOND ROUND OF STORMS...WHICH IS MAXIMIZED IN THE LATE
EVENING AND EARLY MORNING HOURS WHEN THE PERIOD OF HIGHEST CONCERN
FOR HEAVY RAIN EXISTS. MANY AREAS WILL SEE HEAVY RAIN ACTIVITY WITH
THIS WAVE...BUT HAVE HELD ONTO THE FLASH FLOOD WATCH FOR THE CURRENT
AREAS THAT RECEIVED THE HEAVIEST RAINS LAST NIGHT. LEAST FAVORED
AREAS ARE SOUTH AND EAST OF INTERSTATE 57 AND HAVE PLACED HIGHEST
QPF IN THE MOST FAVORED FORCING LOCATIONS IN NORTH AND NORTH CENTRAL
ILLINOIS. MOST UNSTABLE CAPE IN EXCESS OF 1000 J/KG AND EFFECTIVE
SHEAR OF 40+ KT SUGGEST THE POTENTIAL FOR SEVERE HAIL AND LOCALLY
STRONG WINDS AGAIN WITH THE LATER EVENING STORMS...WITH THE WIND
THREAT CONTINGENT ON STORMS EVOLVING INTO A LINE.
THE SURFACE LOW CONTINUES DEEPENING OVERNIGHT AS IT MOVES NORTHEASTWARD.
THE COLD FRONT SPREADS IN FROM NORTHWEST TO SOUTHEAST WHICH
SHOULD EASE SHOWER/STORM THREAT OVERNIGHT. BRISK NORTHWEST WINDS
WILL USHER IN A MUCH COOLER AND DRIER AIRMASS.
KMD
&&
.LONG TERM...
236 PM CDT
SATURDAY THROUGH FRIDAY...
MID-LEVEL SHORT WAVE TROUGH AND SURFACE FRONTAL SYSTEM ASSOCIATED
WITH SHORT TERM RAIN/THUNDERSTORMS WILL BE MOVING OUT OF THE
FORECAST AREA EARLY SATURDAY MORNING. LINGERING LOW LEVEL MOISTURE
BEHIND THE FRONT AND FORCING ASSOCIATED WITH THE PASSAGE OF THE
MID-LEVEL TROUGH MAY ALLOW A FEW SHOWERS/SPRINKLES TO PERSIST
MAINLY ACROSS THE FAR SOUTHEAST PARTS OF THE CWA PAST
SUNRISE...THOUGH BREEZY NORTH WINDS QUICKLY ADVECT DRIER AIR INTO
THE REGION PER FORECAST SOUNDINGS ALLOWING A QUICK END TO ANY
PRECIP AND DECREASING CLOUD COVER THROUGH THE LATE MORNING HOURS.
WHILE SUNSHINE RETURNS...COOLER TEMPS IN THE UPPER 60S/AROUND 70
AND BREEZY NORTH WINDS GUSTING AROUND 20 MPH ESPECIALLY IN THE
MORNING WILL MAKE FOR AN AUTUMN FEEL. SURFACE HIGH PRESSURE BUILDS
ACROSS THE AREA SATURDAY NIGHT...WITH CLEAR SKIES...LIGHT/CALM
WINDS AND COOL/DRY AIR MASS...WILL LIKELY PRODUCE SOME CHILLY LOW-
MID 40S IN COOLER SPOTS AND HAVE UNDERCUT GUIDANCE/BLENDED TOWARD
COOLER MAV MINS. BREEZY NORTH WINDS GUSTING 20-25 MPH SATURDAY
MORNING/EARLY AFTERNOON WILL QUICKLY DIMINISH DURING THE
AFTERNOON.
REST OF EXTENDED PERIOD LOOKS TO REMAIN VERY QUIET...WITH A
GRADUAL MODERATING TREND THROUGH MID/LATE WEEK AS UPPER RIDGE
DEVELOPS OVER THE SOUTHWESTERN CONUS...AND EVENTUALLY BUILDS
NORTHEASTWARD INTO THE GREAT LAKES REGION BY MID-WEEK. SURFACE
HIGH SLIDES EAST OF THE AREA BY LATER SUNDAY...THOUGH WESTERN
PERIPHERY OF SFC RIDGE AXIS LINGERS ACROSS THE REGION FOR A FEW
DAYS. THIS SETS UP A FAIRLY PLEASANT PERIOD OF MILD DAYS WITH
TEMPS SLOWLY WARMING FROM THE LOW 70S (UPPER 60S NEAR THE LAKE) TO
75-80/LOW 80S RANGE BY THE LATTER HALF OF THE WEEK...WITH LOWS IN
THE 40S/50S MODERATING BACK INTO THE 50S/NEAR 60.
NO REAL THREAT OF ORGANIZED RAIN APPEARS AT THIS TIME BEYOND
SATURDAY MORNING...UNTIL PERHAPS LATE THURSDAY OR FRIDAY AS A WEAK
COLD FRONT SETTLES ACROSS THE UPPER MISSISSIPPI/WESTERN LAKES
REGION. SOME MODEL SOLUTIONS KEEP THIS FRONT NORTH OF THE AREA
HOWEVER...OR DONT DEVELOP SIGNIFICANT PRECIP ALONG IT...WITH THE
UPPER RIDGE RE-BUILDING INTO NEXT WEEKEND. THUS HAVE HELD FORECAST
DRY THROUGH FRI AND GIVEN JUST A NOD TO SLIGHTLY COOLER TEMPS
ACROSS THE NORTHERN PART OF THE FORECAST AREA BY FRIDAY PER
BLENDED GUIDANCE.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* MVFR CIGS INTO THE EARLY AFTN.
* WIND SHIFT TO NE THIS AFTN.
* SCT SHRA AND TSRA PSBL THIS AFTN WITH LAKE BREEZE...MORE
WIDESPREAD TSRA AND SHRA EXPECTED THIS EVENING AND OVERNIGHT.
* IFR CIGS AND GUSTY NW WINDS LATE TONIGHT INTO TOMORROW WITH
GUSTS ARND 25 KT.
* WINDS SHIFT TO NE ARND 10KT SATURDAY AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
A MESSY FORECAST IS UPON US. MVFR STRATUS IS SPREAD ACROSS MUCH OF
THE REGION AND IS SLOWLY LIFTING. LATEST MODEL ANALYSIS SHOWS
AREAS SOUTH OF I-80 ARE PRIMED FOR THUNDERSTORM DEVELOPMENT AND
THE STALLED FRONTAL BOUNDARY IS STILL LOCATED FROM WAUKEGAN
TO YORKVILLE TO FAR SOUTHEAST IOWA. EXPECTING THUNDERSTORMS TO
FORM SOUTH OF THE TERMINALS OVER THE NEXT COUPLE OF HOURS AND THEN
SHIFT NORTHEAST REACHING THE TERMINALS ARND 21Z.
GUIDANCE IS INDICATING A SLOWER SHIFT TO NE WINDS WITH WIND
SPEEDS ARND 7-8KT. DECIDED TO KEEP 9KT SINCE PREVIOUS MODEL RUNS
WERE SHOWING 10KT. PUSHED THE LAKE BREEZE TIMING BACK TO 21Z WHICH
IS SUPPORTED BY ALL LAKE FRONT BUOYS STILL SHOWING SOUTHWEST
WINDS.
A LOW PRESSURE SYSTEM CURRENTLY OVER THE CENTRAL PLAINS RACES OVER
NORTHERN IL THIS EVENING BRINGING MORE WIDESPREAD SHOWERS AND
STORMS. HEAVY RAIN IS POSSIBLE AT TIMES THIS EVENING WHICH COULD
RESULT IN MVFR VSBY. EXPECTING IFR CIGS TO MOVE IN BEHIND THE LOW
AND PERSIST INTO THE MORNING WINDS WILL BEGIN TURNING TO SE EARLY
THIS AFTN AND KEEP VEERING TO NW AND GUSTING TO 25KT LATE TONIGHT
INTO SATURDAY MORNING. SKIES BECOME VFR AS THE LOWER CIGS SHIFT
EAST WITH THE LOW AND WINDS WILL BECOME NE ARND 10KT SATURDAY
AFTN.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN WHEN MVFR CIGS WILL IMPROVE TO VFR.
* MEDIUM CONFIDENCE IN TIMING OF WIND SHIFT THIS AFTN AND IN
SHRA/TSRA ASSOCIATED WITH IT...LOW CONFIDENCE IN SEEING 10 KT.
* HIGH CONFIDENCE IN SHRA AND TSRA THIS EVENING AND TONIGHT.
* MEDIUM-HIGH CONFIDENCE IN IFR CIGS.
* MEDIUM CONFIDENCE IN TIMING OF NE WINDS SATURDAY AFTERNOON.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
* SATURDAY NIGHT...DRY/VFR.
* SUNDAY THRU THURSDAY...DRY/VFR. EASTERLY WINDS/LAKE BREEZES.
&&
.MARINE...
303 AM...LOW PRESSURE NEAR JAMES BAY WILL CONTINUE LIFTING
NORTHEAST ACROSS NORTHERN QUEBEC TODAY. A TRAILING COLD FRONT
FROM THIS LOW WILL MOVE SOUTH ACROSS THE LAKES REGION TODAY AND
THEN STALL ACROSS SOUTHERN LAKE MICHIGAN THIS AFTERNOON AS LOW
PRESSURE OVER THE PLAINS BEGINS TO LIFT NORTHEAST. THIS LOW WILL
DEEPEN AS IT MOVES ALONG THE FRONT TONIGHT. AS THE LOW REACHES
LAKE HURON BY SATURDAY MORNING...THE GRADIENT WILL TIGHTEN WITH
HIGH PRESSURE BUILDING ACROSS THE PLAINS. THIS TIGHT GRADIENT
COMBINED WITH COOLER AIR SPREADING ACROSS THE REGION WILL ALLOW
WINDS TO APPROACH GALE FORCE SATURDAY MORNING. AS THE LOW
CONTINUES NORTHEAST SATURDAY AND THE HIGH OVER THE PLAINS MOVES
INTO THE SOUTHERN LAKES REGION SATURDAY NIGHT...WIND SPEEDS/GUSTS
SHOULD STEADILY DIMINISH SATURDAY AFTERNOON INTO SATURDAY EVENING.
WHILE THE CENTER OF THIS HIGH WILL MOVE TO NEW ENGLAND BY EARLY
NEXT WEEK...A WEAKER RIDGE WILL EXTEND TO THE SOUTHWEST AND ACROSS
SOUTHERN LAKE MICHIGAN WITH SOUTHERLY WINDS ACROSS NORTHERN
PORTIONS OF THE LAKE AND EAST/NORTHEAST WINDS OVER THE SOUTHERN
PART OF THE LAKE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022...7
PM FRIDAY TO 7 AM SATURDAY.
IN...NONE.
LM...GALE WATCH...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...4 AM SATURDAY TO 1 PM SATURDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
214 PM CDT FRI SEP 18 2015
.SHORT TERM...
211 PM CDT
THROUGH TONIGHT...
IN ADDITION TO SOME LIGHT RAIN/DRIZZLE FARTHER NORTH...WE ARE
BEGINNING TO SEE SCATTERED SHOWER DEVELOPMENT FARTHER NORTH INTO
OUR AREA THIS AFTERNOON AS THE AREA BEGINS TO FEEL MORE OF THE
LIFT FROM A PAIR OF LEADING SHORTWAVES AHEAD OF A VERY WELL
DEFINED UPPER LEVEL TROUGH AND CLOSED CIRCULATION MOVING EAST
THROUGH THE DAKOTAS. THE FIRST OF THESE WAVES IS PUSHING INTO WEST
CENTRAL ILLINOIS WHERE MORE ORGANIZED THUNDERSTORM ACTIVITY IS
FOCUSED. THESE ARE IN AREAS WHERE EARLIER BREAKS IN LOWER LEVEL
STRATUS HAVE ENABLED GREATER DESTABILIZATION. A STATIONARY
FRONTAL BOUNDARY REMAINS DRAPED ACROSS THE WESTERN CWA. ADDITIONAL
ELEVATED THUNDERSTORMS THROUGH SOUTHERN IOWA AND EXTENDING TO NEAR
THE MISSISSIPPI RIVER IN FAR EASTERN IOWA AHEAD OF THESE
ADDITIONAL LEADING SHORTWAVES.
EXPECT SHOWERS AND ISOLATED THUNDERSTORMS TO INCREASE IN COVERAGE
INTO NORTHEAST ILLINOIS AND NORTHWEST INDIANA. AS THE AFTERNOON
CONTINUES. WITH THE THICK CLOUD COVER FARTHER NORTH...FEEL THE MORE
ACTIVE STORMS WILL BE CONFINED ALONG AND SOUTH OF INTERSTATE 80
WHERE LOCALLY HEAVY RAINFALL IS EXPECTED AND STORM MOTION IS NOT
SUPER FAST. A SEVERE THREAT EXISTS AS WELL DUE TO MODEST MID LEVEL
LAPSE RATES (NEAR 7 DEG/KM ON THE KDVN MORNING SOUNDING)...THOUGH
SHEAR HAS DECREASED SOMEWHAT LOWER THAN WHAT WAS DEPICTED EARLIER
TODAY ON THE RAP SPC MESOANALYSIS. IT IS FORECAST TO INCREASE
AGAIN AS THE AFTERNOON CONTINUES...KEEPING SOME THREAT FOR GUSTY
WINDS AND HAIL MAINLY FOR OUR WESTERN AND SOUTHERN AREAS.
WIDESPREAD SEVERE WEATHER WITH THIS WAVE IS NOT ANTICIPATED AS
SHOWERS/STORMS TO THE NORTH WILL BE ELEVATED.
IT LOOKS LIKE AFTER THIS ACTIVITY MOVES THROUGH...THERE COULD BE A
SHORT BREAK BEFORE THE MORE ORGANIZED ACTIVITY ASSOCIATED WITH THE
UPPER TROUGH MOVES THROUGH LATER THIS EVENING AND TONIGHT. THIS
BREAK...IF IT OCCURS...WOULD LAST THE LONGEST FOR POINTS SOUTH AND
EAST ABD THERE MAY NOT BE MUCH OF A BREAK IN AREAS NORTH AND WEST.
THE TIMING ON THIS ROUND OF MORE ORGANIZED THUNDERSTORM ACTIVITY IS
AFTER 7-8 PM IN THE WEST...AND AFTER 9 PM CLOSER TO CHICAGO. CURRENT
SHORT TERM RUNS OF THE HRRR/RAP SUGGEST IT COULD BE SLIGHTLY LATER
THAN THAT FOR AREAS SOUTH AND EAST OF I-57. THE BEST COMBINATION OF
UPPER Q-G FORCING FROM THE UPPER TROUGH AND LOWER FRONTOGENETICAL
FORCING ON THE BACK SIDE OF THE SURFACE LOW IS ALONG AND NORTH OF I-
80 FOR THIS SECOND ROUND OF STORMS...WHICH IS MAXIMIZED IN THE LATE
EVENING AND EARLY MORNING HOURS WHEN THE PERIOD OF HIGHEST CONCERN
FOR HEAVY RAIN EXISTS. MANY AREAS WILL SEE HEAVY RAIN ACTIVITY WITH
THIS WAVE...BUT HAVE HELD ONTO THE FLASH FLOOD WATCH FOR THE CURRENT
AREAS THAT RECEIVED THE HEAVIEST RAINS LAST NIGHT. LEAST FAVORED
AREAS ARE SOUTH AND EAST OF INTERSTATE 57 AND HAVE PLACED HIGHEST
QPF IN THE MOST FAVORED FORCING LOCATIONS IN NORTH AND NORTH CENTRAL
ILLINOIS. MOST UNSTABLE CAPE IN EXCESS OF 1000 J/KG AND EFFECTIVE
SHEAR OF 40+ KT SUGGEST THE POTENTIAL FOR SEVERE HAIL AND LOCALLY
STRONG WINDS AGAIN WITH THE LATER EVENING STORMS...WITH THE WIND
THREAT CONTINGENT ON STORMS EVOLVING INTO A LINE.
THE SURFACE LOW CONTINUES DEEPENING OVERNIGHT AS IT MOVES NORTHEASTWARD.
THE COLD FRONT SPREADS IN FROM NORTHWEST TO SOUTHEAST WHICH
SHOULD EASE SHOWER/STORM THREAT OVERNIGHT. BRISK NORTHWEST WINDS
WILL USHER IN A MUCH COOLER AND DRIER AIRMASS.
KMD
&&
.LONG TERM...
304 AM CDT
SATURDAY NIGHT THROUGH THURSDAY...
SFC RIDGE REMAINS OVERHEAD SAT
NGT INTO SUN...WITH A THERMAL TROUGH OF 6 TO 8 DEG C COVERING MUCH
OF THE WESTERN GREAT LAKES. WITH MINIMAL CLOUD COVER SAT NGT TEMPS
WILL FALL INTO THE UPR 40S TO LOW 50S. THEN SUN REMAIN SEASONAL ARND
70 TO THE LOW 70S.
THE REMAINDER OF THE EXTENDED PERIODS CONTINUE TO LOOK
SEASONAL...WITH MINIMAL SPREAD BEING PROGGED BY ENSEMBLES WITH THE
500MB LONGWAVE PATTERN LIFTING THE GREAT LAKES TROUGH EAST AND
WEAKENING WITH WEAK HEIGHT INCREASES TOWARDS MIDDLE OF NEXT WEEK.
OVERALL THE EXTENDED LOOKS TO BE DRY WITH SEASONAL TEMPS IN THE
LOW/MID 70S AND OVERNIGHT LOWS IN THE UPR 40S TO MID 50S. CURRENTLY
THE NEXT CHANCE FOR PRECIP DOESN/T ARRIVE UNTIL CLOSER TO THURS.
BEACHLER
&&
.HYDROLOGY...
VERY MOIST ATMOSPHERE CONTINUES TO FEED NORTHEAST ACROSS NORTHERN
TODAY...AND INTO TONIGHT. EARLY THIS MORNING SOME HEAVY RAIN HAS
FALLEN AS A RESULT OF OVERNIGHT THUNDERSTORMS...MAINLY ALONG AND
NORTH OF THE I-88 CORRIDOR. THIS MOIST AXIS WILL CONTINUE OVER
THIS SAME AREAS TODAY WITH A LULL IN THE THUNDERSTORM COVERAGE
THRU THIS AFTERNOON. WHILE A FEW THUNDERSTORMS WILL BE POSSIBLE
AND COULD EASILY PRODUCE SOME HEAVY RAIN PRIOR TO
SUNSET...GUIDANCE CONTINUES TO POINT TOWARDS THE MORE WIDESPREAD
AND HEAVY RAIN POTENTIAL ARRIVING AFTER SUNSET THROUGH
MIDNIGHT/EARLY SATURDAY MORNING. AS A RESULT HAVE ISSUED A FLASH
FLOOD WATCH FOR MOST OF NORTHERN ILLINOIS...BUT MAINLY ALONG AND
NORTH OF THE INTERSTATE 80 CORRIDOR.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* MVFR CIGS INTO THE EARLY AFTN.
* WIND SHIFT TO NE THIS AFTN.
* SCT SHRA AND TSRA PSBL THIS AFTN WITH LAKE BREEZE...MORE
WIDESPREAD TSRA AND SHRA EXPECTED THIS EVENING AND OVERNIGHT.
* IFR CIGS AND GUSTY NW WINDS LATE TONIGHT INTO TOMORROW WITH
GUSTS ARND 25 KT.
* WINDS SHIFT TO NE ARND 10KT SATURDAY AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
A MESSY FORECAST IS UPON US. MVFR STRATUS IS SPREAD ACROSS MUCH OF
THE REGION AND IS SLOWLY LIFTING. LATEST MODEL ANALYSIS SHOWS
AREAS SOUTH OF I-80 ARE PRIMED FOR THUNDERSTORM DEVELOPMENT AND
THE STALLED FRONTAL BOUNDARY IS STILL LOCATED FROM WAUKEGAN
TO YORKVILLE TO FAR SOUTHEAST IOWA. EXPECTING THUNDERSTORMS TO
FORM SOUTH OF THE TERMINALS OVER THE NEXT COUPLE OF HOURS AND THEN
SHIFT NORTHEAST REACHING THE TERMINALS ARND 21Z.
GUIDANCE IS INDICATING A SLOWER SHIFT TO NE WINDS WITH WIND
SPEEDS ARND 7-8KT. DECIDED TO KEEP 9KT SINCE PREVIOUS MODEL RUNS
WERE SHOWING 10KT. PUSHED THE LAKE BREEZE TIMING BACK TO 21Z WHICH
IS SUPPORTED BY ALL LAKE FRONT BUOYS STILL SHOWING SOUTHWEST
WINDS.
A LOW PRESSURE SYSTEM CURRENTLY OVER THE CENTRAL PLAINS RACES OVER
NORTHERN IL THIS EVENING BRINGING MORE WIDESPREAD SHOWERS AND
STORMS. HEAVY RAIN IS POSSIBLE AT TIMES THIS EVENING WHICH COULD
RESULT IN MVFR VSBY. EXPECTING IFR CIGS TO MOVE IN BEHIND THE LOW
AND PERSIST INTO THE MORNING WINDS WILL BEGIN TURNING TO SE EARLY
THIS AFTN AND KEEP VEERING TO NW AND GUSTING TO 25KT LATE TONIGHT
INTO SATURDAY MORNING. SKIES BECOME VFR AS THE LOWER CIGS SHIFT
EAST WITH THE LOW AND WINDS WILL BECOME NE ARND 10KT SATURDAY
AFTN.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN WHEN MVFR CIGS WILL IMPROVE TO VFR.
* MEDIUM CONFIDENCE IN TIMING OF WIND SHIFT THIS AFTN AND IN
SHRA/TSRA ASSOCIATED WITH IT...LOW CONFIDENCE IN SEEING 10 KT.
* HIGH CONFIDENCE IN SHRA AND TSRA THIS EVENING AND TONIGHT.
* MEDIUM-HIGH CONFIDENCE IN IFR CIGS.
* MEDIUM CONFIDENCE IN TIMING OF NE WINDS SATURDAY AFTERNOON.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
* SATURDAY NIGHT...DRY/VFR.
* SUNDAY THRU THURSDAY...DRY/VFR. EASTERLY WINDS/LAKE BREEZES.
&&
.MARINE...
303 AM...LOW PRESSURE NEAR JAMES BAY WILL CONTINUE LIFTING
NORTHEAST ACROSS NORTHERN QUEBEC TODAY. A TRAILING COLD FRONT
FROM THIS LOW WILL MOVE SOUTH ACROSS THE LAKES REGION TODAY AND
THEN STALL ACROSS SOUTHERN LAKE MICHIGAN THIS AFTERNOON AS LOW
PRESSURE OVER THE PLAINS BEGINS TO LIFT NORTHEAST. THIS LOW WILL
DEEPEN AS IT MOVES ALONG THE FRONT TONIGHT. AS THE LOW REACHES
LAKE HURON BY SATURDAY MORNING...THE GRADIENT WILL TIGHTEN WITH
HIGH PRESSURE BUILDING ACROSS THE PLAINS. THIS TIGHT GRADIENT
COMBINED WITH COOLER AIR SPREADING ACROSS THE REGION WILL ALLOW
WINDS TO APPROACH GALE FORCE SATURDAY MORNING. AS THE LOW
CONTINUES NORTHEAST SATURDAY AND THE HIGH OVER THE PLAINS MOVES
INTO THE SOUTHERN LAKES REGION SATURDAY NIGHT...WIND SPEEDS/GUSTS
SHOULD STEADILY DIMINISH SATURDAY AFTERNOON INTO SATURDAY EVENING.
WHILE THE CENTER OF THIS HIGH WILL MOVE TO NEW ENGLAND BY EARLY
NEXT WEEK...A WEAKER RIDGE WILL EXTEND TO THE SOUTHWEST AND ACROSS
SOUTHERN LAKE MICHIGAN WITH SOUTHERLY WINDS ACROSS NORTHERN
PORTIONS OF THE LAKE AND EAST/NORTHEAST WINDS OVER THE SOUTHERN
PART OF THE LAKE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022...7
PM FRIDAY TO 7 AM SATURDAY.
IN...NONE.
LM...GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...4 AM SATURDAY TO 1 PM SATURDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS TOPEKA KS
309 PM CDT FRI SEP 18 2015
.SHORT TERM...(THIS EVENING THROUGH Saturday)
ISSUED AT 307 PM CDT FRI SEP 18 2015
Deep moisture and pre-frontal warm air advection keeping a clean
warm sector in check this afternoon but still well over 1000 J/kg
of CAPE and decent shear to support severe thunderstorms. Front is
rather obvious on local radar imagery and looks to be out of the
forecast area shortly after sunset, so next few hours will be the
main severe weather concern for southeastern areas with hail and
wind still the main concerns. Weak surface low pushing northeast
through the area should allow for veering low level wind fields,
helping keep tornado potential low. Locations along and south of
I- 35 saw a few periods of heavy rains this morning and will still
be the main concern area for additional heavy rain and possible
flash flooding into the evening. Passing upper wave should result
in decreasing post-frontal forcing for decreasing potential or
elevated showers and drizzle early on. Low cloud trends are
challenging but will maintain some mention of fog in the northwest
with clearing and lightening winds likely toward dawn. Highs still
look to top around 70 for Saturday in light winds and some mid
cloud.
.LONG TERM...(Saturday NIGHT THROUGH Friday)
ISSUED AT 307 PM CDT FRI SEP 18 2015
Rest of the weekend periods still looking quiet weather-wise with
surface high sinking in before pushing off to the east. A weak
upper wave Sunday strengthens a bit as it enters Kansas but still
too little forcing/dry air below for any precip mention.
Moisture levels increase into the mid week periods with the modest
southwest flow aloft developing though flow still remains weak this
far south. Still appears a weak front may sag south to near Kansas
Monday night into Tuesday, with indications of the weak upper wave
coming nearby around Thursday. With the mid/upper levels still
rather moist it`s hard to rule out precipitation in much of these
periods. Temps should average to be slightly above normal.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Saturday AFTERNOON)
ISSUED AT 1222 PM CDT FRI SEP 18 2015
Elevated storms have moved east of the terminals and much of the
short range model guidance holds off on developing additional TS
until the front is south of the terminals. Based on Satellite and
a lack of towering CU along the front, this seems to make some
sense. So the main concern is the IFR stratus behind the front.
With some heating ahead of the front, am not sure CIGS will be
that low so have some MVFR CIGS moving in behind the front. Both
the NAM and RAP mix out the stratus this evening, but there may be
a chance the low clouds hold on through the night. Confidence in
this is low since there should be good dry air advection behind
the front so have followed the models lead and scattered out the
clouds.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH until 1 AM CDT Saturday for KSZ040-054>056-058-
059.
&&
$$
SHORT TERM...65
LONG TERM...65
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1142 AM MDT FRI SEP 18 2015
.UPDATE...
ISSUED AT 626 AM MDT FRI SEP 18 2015
UPDATED FORECAST FOR TODAY BASED ON LATEST SATELLITE AND MODEL
DATA. PREVIOUS FORECAST HAD A GOOD HANDLE ON THE GENERAL TREND OF
THE RAINFALL...MAINLY SPED UP THE TIMING OF RAIN MOVING OUT OF THE
AREA BASED ON THE LOCATION OF THE ELEVATED CAPE AXIS AT 725MB.
ALSO LOWERED CHANCES FOR RAIN OVER THE NORTHWEST...PARTICULARLY
YUMA COUNTY...DUE TO SUBSIDENCE MOVING OVER THE AREA ON WATER
VAPOR. TIMING OUT THE EASTERN EDGE OF THE SUBSIDENCE HAS IT OVER
THE EASTERN BORDER OF THE TRI-STATE AREA BY 10 AM CT. HOWEVER DID
NOT WANT TO DEVIATE TOO MUCH FROM THE PREVIOUS FORECAST YET SO
HAVE CHANCES RAIN CONTINUING AFTER 10 AM CT BUT DO HAVE THEM
DECLINING FASTER THAN BEFORE.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 244 AM MDT FRI SEP 18 2015
SCATTERED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS WILL CONTINUE
THROUGH THE LATE MORNING/EARLY AFTERNOON AHEAD OF A SHORTWAVE
TROUGH MOVING OUT OF THE NORTHERN HIGH PLAINS. BEST CHANCES WILL
BE IN NEBRASKA. STORMS HAVE STRUGGLED SO FAR BUT HRRR SHOWS
REDEVELOPMENT FURTHER SOUTH BY 12Z SO WILL CONTINUE TO CARRY
SLIGHT TO MID RANGE POPS. MUCAPE GENERALLY LESS THAN 500 J/KG SO
CANNOT RULE OUT AN ISOLATED STRONGER STORM CAPABLE OF PRODUCING
SMALL HAIL. ACTIVITY WILL MOVE EAST BY EARLY AFTERNOON...BUT
STRATUS MAY LINGER UNTIL THEN PARTICULARLY IN EASTERN AREAS
LEADING TO A LOW CONFIDENCE AFTERNOON TEMPERATURE FORECAST.
SIMILARLY...LOW TEMPERATURES TONIGHT COMPLICATED BY REDEVELOPMENT
OF STRATUS AND PATCHY FOG...BUT WITH LIGHT WINDS MAY BE ABLE TO
DROP TO LOWER TO MIDDLE 40S BEFORE SATURATION OCCURS. CLOUDS BURN
OFF AGAIN BY SATURDAY AFTERNOON WITH TEMPERATURES WARMING INTO THE
MIDDLE 70S. MODELS HAVE BACKED OFF ELEVATED THUNDERSTORM POTENTIAL
FOR SATURDAY NIGHT AS IT LOOKS LIKE THE UPPER SHORTWAVE WILL BE
WEAKER AND FURTHER NORTH...SO REDUCED POPS TO SLIGHT CHANCE FOR
THE OVERNIGHT HOURS. SHORTWAVE RIDGING BUILDS IN BEHIND IT FOR
SUNDAY WITH TEMPERATURES REBOUNDING TO THE LOWER 80S UNDER MOSTLY
SUNNY SKIES.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 244 AM MDT FRI SEP 18 2015
A DRY START TO THE WORK WEEK IS EXPECTED AS UPPER LEVEL RIDGING
BUILDS OVER THE AREA FROM THE DESERT SOUTHWEST AND A LEE TROUGH
REDEVELOPS EAST OF THE ROCKIES. THIS SETUP WILL BRING DRIER
CONDITIONS TO THE HIGH PLAINS THROUGH TUESDAY NIGHT.
THE NEXT CHANCE FOR PRECIPITATION PRESENTS ITSELF WEDNESDAY THROUGH
THURSDAY. A SHORTWAVE TROUGH MOVES ONTO THE CALIFORNIA COAST TUESDAY
NIGHT AND TRAVELS OVER THE DESERT SOUTHWEST TOWARDS THE REGION. THE
TROUGH APPEARS TO WEAKEN BUT IT LOOKS LIKE MULTIPLE DISTURBANCES
WILL MOVE THROUGH THE UPPER LEVEL FLOW MIDWEEK GENERATING SHOWER AND
THUNDERSTORM CHANCES FOR THE AREA.
RELATIVELY CONSISTENT TEMPERATURES ARE EXPECTED IN THE EXTENDED
PERIOD WITH HIGHS IN THE MID 80S TO NEAR 90S DEGREES AND LOWS IN THE
MID 50S TO LOW 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1138 AM MDT FRI SEP 18 2015
VFR CONDITIONS ARE FORECAST FOR THE 18Z TAFS. CURRENT WIND SPEEDS
WILL CONTINUE FOR THE MAJORITY OF THE AFTERNOON THEN DECLINE
DURING THE LATE AFTERNOON. THROUGH THE NIGHT WINDS WILL GRADUALLY
TURN TO THE SOUTHEAST. THERE MAY BE SOME LIGHT FOG FOR KMCK BUT
VISIBILITIES SHOULD REMAIN VFR.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...024
LONG TERM...JBH
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1222 PM CDT FRI SEP 18 2015
...AVIATION UPDATE...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 255 AM CDT FRI SEP 18 2015
Early this morning the cold front was roughly bisecting the CWA,
stretching from Alta Vista to Wamego to Hiawatha. The mid-level
trough was stretched across the northern Rockies, advancing into the
Northern Plains. Water vapor imagery showed a weak embedded wave
within the mid-level flow over southeast Kansas, which, combined
with the low-level jet axis, was helping to produce scattered
thunderstorms that were tracking northeastward into east central
Kansas. Short-range models show these scattered storms diminishing
across east central Kansas shortly after sunrise, with the focus for
additional showers and thunderstorms shifting northward to the
Nebraska/Kansas border as some enhanced lift is expected across that
area ahead of the advancing trough. While the best moisture and
lift with this morning activity may be focused in far southeast
Nebraska, there is some uncertainty still amongst the short-range
models with how far south into north central and northeast Kansas
this precipitation will develop. The coverage of this morning
activity certainly may have an impact on the potential for severe
storms this afternoon as there is uncertainty with regards to how
much the region will destabilize this morning into this afternoon.
However, there is the potential for several favorable conditions to
come together to support the development of some supercell
thunderstorms. Expect enhanced lift by this afternoon as you have
the cold front still stretched across eastern Kansas and the mid-
level trough sweeping across the Northern and Central Plains, which
will help to push this stalled system eastward out of the area by
this evening. In addition to ample lift in the low/mid levels,
models continue to show limited inhibition by early to mid afternoon
with CAPE values upwards of 1500-2000 J/kg and 0-6km bulk shear
values of around 40kts. As a result, the primary threats will be
some damaging winds and large hail. However, it is worth noting
that 0-1km bulk shear and helicity values across far northeast
Kansas into northwest/far northern Missouri suggest that there is an
isolated tornado threat as well for a small window of time, likely
mid to late afternoon for far northeast Kansas. Also cannot rule
out the potential for some locally heavy rainfall from these storms
as PWAT values should be upwards of 1.7-1.9 inches with some
training storms possible as the low-level flow should be roughly
parallel to the exiting boundary. The main area of concern for some
localized flooding would be across far northeast Kansas where
upwards of 2-3 inches of rain fell last evening from thunderstorms.
The advancing trough will help to quickly push the front eastward
out of the area by early evening, with cooler, drier air quickly
surging into the area behind this system. With the placement of the
front and the potential for scattered morning precipitation, have
cooled high temperatures a bit for today with a decent spread
expected, ranging from around 70 in north central Kansas to the
middle 80s in east central Kansas. Expect dry conditions by the
overnight hours tonight and temperatures cooling into the upper 40s
to low 50s.
.LONG TERM...(Saturday THROUGH Thursday)
ISSUED AT 255 AM CDT FRI SEP 18 2015
The strong cold front will have pushed through the forecast area
by early Saturday morning with precipitation rapidly clearing out.
Strong high pressure will build toward the area and remnant low
level moisture may allow patchy fog to develop around sunrise on
Saturday in north central KS where winds will become light.
Temperatures will be much cooler through the weekend with highs
around 70 on Saturday and in the mid 70s on Sunday. Lows each
morning should be around 50...cooler in north central KS early
Saturday and cooler in eastern KS early Sunday given proximity to
the surface high pressure and heart of the cool airmass. By late
Sunday, short wave energy will move northwest to southeast across
the area. This will provide a fair amount of vertical motion
across the area but moisture will be lacking and have kept the
forecast dry at this time.
Weak upper ridging builds into the region for early next week with
an associated warming trend back well into the 80s for much of the
week. Monday night into Tuesday a weak front will sag into the
area and may provide a focus for a few storms. Otherwise the next
potential precipitation maker is in the form of a short wave
trough forecast to move from Southern California into the Central
Plains by Thursday.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Saturday AFTERNOON)
ISSUED AT 1222 PM CDT FRI SEP 18 2015
Elevated storms have moved east of the terminals and much of the
short range model guidance holds off on developing additional TS
until the front is south of the terminals. Based on Satellite and
a lack of towering CU along the front, this seems to make some
sense. So the main concern is the IFR stratus behind the front.
With some heating ahead of the front, am not sure CIGS will be
that low so have some MVFR CIGS moving in behind the front. Both
the NAM and RAP mix out the stratus this evening, but there may be
a chance the low clouds hold on through the night. Confidence in
this is low since there should be good dry air advection behind
the front so have followed the models lead and scattered out the
clouds.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH through late tonight for KSZ026-037>040-
054>056-058-059.
FLASH FLOOD WATCH until 10 PM CDT this evening for KSZ011-012-
024.
&&
$$
SHORT TERM...Hennecke
LONG TERM...Barjenbruch
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
311 PM CDT FRI SEP 18 2015
.SHORT TERM...(This Evening through Sunday Night)
Issued at 311 PM CDT FRI SEP 18 2015
Complicated forecast shaping up for the remainder of this afternoon
and evening as long advertised front slowly works through the area.
At 3 PM...regional radars showed a clearly defined fine line slowly
working south through northwest Missouri and northeast
Kansas...indicative of the current position of the boundary in
question. As expected...sfc low across east-central Kansas continues
to slowly lift northeastward along the boundary...with plenty of pre-
frontal precipitation prevailing over the fcst region this afternoon.
Looking aloft...afternoon water vapor imagery showing a nicely
defined neutrally tilted trough axis digging through the Central
Plains...with a mid-level jetstreak extending from east-central
Colorado northeastward into south-central Nebraska. Forcing for
ascent will continue to increase through the late afternoon/early
evening as aforementioned wave approaches...but morning and early
afternoon convection has certainly thrown a monkey wrench into
today/s forecast.
Latest visible satellite images finally showing some clearing in
advance of the boundary this afternoon...and latest MLCAPE estimates
from the SPC meso page are responding accordingly. Quick look at the
GOES 7.4 micron channel shows leading edge of a secondary EML plume
advancing east through west-central Kansas this afternoon...with new
convection beginning to develop southwest of Topeka right ahead of
the front. In the time its taken to write this much of the
AFD...we/ve gone from little hope for severe to renewed optimism
that things may in fact get going. That said...latest HRRR appears
to be taking into account the partial clearing with decreased
surface inhibition and now shows convection working through the KC
Metro during the evening rush hour. As a result...all hope does is not
lost as of right now anyways. If convection can in fact become
organized /and there/s plenty of deep layer shear to support this/
large hail and damaging winds will be possible...especially if
surface based inhibition erodes accordingly. Additionally...bulk
shear vector orientation normal to the linear line of forcing will
support supercell structures with eventual progression into linear
segments as convection is able to congeal after sunset. Again...this
scenario is only of marginal confidence at this point...and the next
few hours will be telling on what is actually able to get
organized...if anything.
Additionally...concerns for heavy rainfall continue this afternoon as
an axis of anomalously high PWAT values (> 1.7") remains entrenched
across the fcst area. Combine this with the most recent images from
the experimental layered PW satellite product from Colorado State
which shows converging subtropical and northern stream moisture
plumes over the Lwr Missouri Vly...organized rainfall should have
little problem producing heavy rainfall rates across the area.
Considering the amount of uncertainty with the going forecast this
afternoon...will go ahead and leave the current flash flood watch in
place until clearing begins to occur from west to east later tonight.
Front to plow through the region overnight with precip quickly coming
to an end after 6z or so. Dry air will quickly move in by Saturday
morning as high pressure builds south across the Central
Plains/upper Miss Rvr Vly. As cold air infiltrates the
area...afternoon highs tomorrow afternoon will struggle to make it
out of the upper 60s. Slightly warmer temps are expected on
Sunday...with highs likely warming into the lower to middle 70s
across most locations. Warming trend will commence early next week as
southerly flow returns to the area.
.LONG TERM...(Tuesday through Friday)
Issued at 311 PM CDT FRI SEP 18 2015
Upper-level ridging will then build from the Southern Plains and
extend into the Central Plains. Pressure falls over west central
Kansas, however, will pull in warm and moist air by the mid to latter
half of the week. An advancing shortwave trough should provide enough
lift within this region to produce some precipitation within the warm
sector of the low center by the late week. With no distinguishable
boundary in place, any activity that does develop should remain
relatively light. Continued southerly flow in place will push
afternoon highs slightly above average before returning to normal by
the end of the week.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon)
Issued at 1234 PM CDT FRI SEP 18 2015
Difficult fcst as convection remains prevalent across the area this
afternoon. Initial round of activity currently moving through area
terminals...with another round expected later this afternoon as main
front starts to move through the area. At worst...this initial round
may lead to tempo MVFR conditions. Of more concern however will be
the possibility of developing IFR cigs following the passage of the
the second round later this afternoon/evening. Although of only
marginal confidence ...have inserted a secondary tempo group after
21z to account for low CIGS and secondary convection possibilities.
As always...will make adjustments as needed. Precip chances look to
quickly decrease after 3z as front departs to the east.
Low cigs to hang on for much of the night before skies begin to clear
after 14z Saturday morning.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...FLASH FLOOD WATCH through Saturday morning for KSZ025-057-060-
102>105.
MO...FLASH FLOOD WATCH through Saturday morning for MOZ001>008-
011>017-020>025-028>033-037>040-043>046-053-054.
&&
$$
SHORT TERM...32
LONG TERM...Welsh
AVIATION...32
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1240 PM CDT FRI SEP 18 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 335 AM CDT FRI SEP 18 2015
THE PRIMARY FORECAST CONCERNS ARE PCPN CHANCES/COVERAGE TODAY INTO
THIS EVENING...POTENTIAL FOR LOW CLOUDS AND OR PATCHY FOG TONIGHT
AND TEMPERATURES THE NEXT FEW DAYS.
MAIN FEATURES FROM UPPER LEVEL CHARTS LAST EVENING INCLUDED THE
FOLLOWING. A JET MAX OF 80-90 KNOTS AT 300 MB WAS OVER WY AND CO
LIFTING NORTHEAST. BEST 12 HOUR HEIGHT FALLS AT 500 MB WERE OVER
THE NRN PLAINS AND LIFTING INTO CANADA...BUT THE MAIN TROUGH AXIS
WAS STILL BACK OVER THE ROCKIES. THERMAL RIDGE AT 700 MB HAD
FLATTENED A BIT...AND EXTENDED FROM SRN NM INTO CNTRL MO. 850 MB
SHOWED HIGH PRES OVER THE DKTS AND N WINDS OVER THE CNTRL PLAINS
WITH CDFNT CURVING FROM WRN WI INTO NERN KS THEN BACK INTO ERN CO.
SFC ANLYS AT 08Z SHOWED TEMPERATURES IN THE 50S ACROSS OUR NRN
ZONES AND UPPER 60S/LOWER 70S NEAR THE KS AND MO BORDERS.
SHORT RANGE MODELS ARE IN FAIRLY GOOD AGREEMENT SHOWING PCPN
COVERAGE INCREASING THIS MORNING. PCPN CHANCES ARE HIGHEST ACROSS
OUR ERN AND SRN COUNTIES INTO MID AFTN. WILL MENTION AT LEAST
ISOLD TSTMS EVEN INTO PARTS OF NERN NE WITH ELEVATED INSTABILITY
MUCH OF THE DAY. USED SPC SREF MU CAPE OF 500 J/KG OR MORE AND
FCST SOUNDINGS TO HELP DETERMINE AREA WITH THUNDER POTENTIAL.
RECENT EXPERIMENTAL HRRR RUNS SEEM REASONABLE WITH PCPN COVERAGE
AND TIMING. WILL STAY FAIRLY CLOSE TO MOS GUIDANCE FOR HIGHS
TODAY...GENERALLY MID OR UPPER 60S...BUT SOME LOWER 70S PSBL IN
THE S. MAIN AREA OF SHOWERS WILL BE MOVING EAST OUT OF OUR AREA
EARLY THIS EVENING...BUT AN AREA OF LIGHT PCPN COULD MOVE OUT OF
CNTRL NE/CNTRL SD INTO PARTS OF NERN NE BEFORE ENDING EARLY THIS
EVENING. QUESTION THEN BECOMES...HOW MUCH CLEARING WILL OCCUR.
PRESSURE GRADIENT REMAINS MODEST...SO FOG POTENTIAL DOES NOT
APPEAR OVERLY HIGH. BUT...WE MAY SEE SOME STRATUS. NAM IS THE
MOST AGGRESSIVE WITH LOW CLOUDS TONIGHT. KEPT SOME CLOUDS IN...
BUT DID NOT COMPLETELY BUY INTO THE NAM OUTPUT AT THIS POINT.
SATURDAY THROUGH SUNDAY SHOULD BE DRY...WITH HIGHS SATURDAY MAINLY
IN THE UPPER 60S AND HIGHS SUNDAY IN THE 70S.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 335 AM CDT FRI SEP 18 2015
TEMPERATURES SHOULD SLOWLY MODERATE THROUGH MID WEEK...THEN DROP
OFF A BIT TOWARD THURSDAY/FRIDAY. A MID LEVEL RIDGE WILL BUILD
EAST FROM THE ROCKIES...THEN EXTEND FROM MEXICO TOWARD THE GREAT
LAKES REGION BY THURSDAY. THERE WILL BE SOME LOW CHANCES FOR
SHOWERS AND THUNDERSTORMS...MAINLY FROM MONDAY NIGHT INTO TUESDAY
THEN WEDNESDAY NIGHT INTO THURSDAY NIGHT.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1233 PM CDT FRI SEP 18 2015
THUNDERSTORMS ARE ONGOING ACROSS THE REGION BUT ARE BEGINNING TO
WANE ACROSS NEBRASKA. ANY STRONG TO SEVERE STORMS WILL NOT IMPACT
THE THREE TAF SITES. THAT SAID EXPECT CONTINUED LIGHT RAIN AT ALL
TAF SITES THROUGH MID AFTERNOON...WITH VFR CONDITIONS EXPECTED
THEREAFTER. WINDS MAY BE VARIABLE DIRECTION-WISE AS THUNDERSTORMS
PUSH EAST BUT SHOULD VEER BACK TO NORTHERLY BY LATE AFTERNOON.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...PEARSON
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
335 PM MDT FRI SEP 18 2015
.SYNOPSIS...
A BACKDOOR COLD FRONT WILL PUSH SOUTH AND WEST THROUGH EASTERN NEW
MEXICO THIS EVENING AND INTO THE RIO GRANDE VALLEY AND POINTS
WEST AFTER MIDNIGHT. GUSTY EAST CANYON WINDS WILL DEVELOP IN THE
ALBUQUERQUE METRO AREA LATE TONIGHT INTO FRIDAY MORNING. COOLER
AIR WILL PUSH IN BEHIND THE FRONT WITH LITTLE IN THE WAY OF
PRECIPITATION. BEST CHANCES FOR ANY SHOWERS OR THUNDERSTORMS WILL
BE OVER THE SOUTHWEST AND SOUTH-CENTRAL MOUNTAINS SATURDAY
AFTERNOON. SOUTHERLY FLOW BETWEEN AN AREA OF LOW PRESSURE JUST
WEST OF BAJA CALIFORNIA AND HIGH PRESSURE OVER FAR WEST TEXAS WILL
BEGIN TO PUSH SUBTROPICAL MOISTURE AND ASSOCIATED SHOWERS AND
THUNDERSTORMS NORTH INTO NEW MEXICO EARLY NEXT WEEK.
&&
.DISCUSSION...
BACKDOOR COLD FRONT SLIGHTLY AHEAD OF 18Z NAM12 MODEL FORECAST
THIS AFTERNOON. SFC OBS AND RADAR SUGGESTING THE FRONT IS NEAR A
WAGON MOUND TO SAN JON LINE...HEADING SWWD. FRONT EXPECTED TO
MAKE THE TYPICAL SURGE SOUTH AND WEST AFTER SUNSET. EAST WINDS
WILL LIKELY BREAK THROUGH GLORIETA PASS AND TIJERAS CANYON JUST
BEFORE MIDNIGHT. EAST CANYON WINDS INTO THE ABQ METRO AREA ARE
FORECAST TO BE IN THE 25 TO 35 MPH RANGE WITH LOCAL GUSTS TO 45
MPH POSSIBLE DOWNSTREAM FROM TIJERAS CANYON. GUSTY EAST WINDS WILL
ALSO DEVELOP SOUTH OF I-40...WEST OF ABO PASS AS WELL AS BONADO
GAP NEAR CARRIZOZO. BOTH GFS AND NAM ARE NOT ONLY HIGHLY STABLE
BEHIND THE FRONT BUT KEEP A VERY DRY WLY FLOW ABOVE ABOUT 650MB IN
PLACE THROUGH SATURDAY. FAVORED AREAS FOR SHOWERS AND
THUNDERSTORMS WILL BE OVER THE SOUTHWEST AND SOUTH-CENTRAL
MOUNTAINS SATURDAY AFTERNOON WHERE DEEPER MOISTURE WILL COMBINE
WITH SURFACE CONVERGENCE ALONG THE FRONT.
FOUR CORNERS HIGH PROGGED TO REBUILD OVER WEST-CENTRAL NM/ERN AZ
SUNDAY...RESULTING IN A DRY NORTH TO NW FLOW ALOFT OVER THE
AREA. THIS FLOW WILL MAKE IT RATHER TOUGH FOR MORE THAN A FEW
SHOWERS OR STORMS TO DEVELOP OVER THE FAR SRN/SWRN PORTIONS OF
CATRON...LINCOLN AND CHAVES COUNTIES SUNDAY. DRY AND BREEZY
CONDITIONS EXPECTED ELSEWHERE.
MODELS STILL ON TRACK FOR EARLY NEXT WEEK WITH SLY FLOW ALOFT
BETWEEN CLOSED UPPER LOW OFF NRN BAJA AND THE FOUR CORNERS HIGH
..WHICH HAS NOW SHIFTED SEWD OVER FAR W TX. MODELS STILL
SUGGESTING DEEP SUBTROPICAL MOISTURE WILL BEGIN TO STREAM INTO SW
NM LATE-DAY MONDAY AND MONDAY NIGHT. ECMWF ABOUT 12 HOURS SLOWER
WITH THE MOISTURE SURGE BUT HAS A VERY SIMILAR PATTERN SET UP. GFS
AND ECMWF IN GOOD AGREEMENT THAT SHOWERS AND STORMS HANG AROUND
THROUGH MID-WEEK BEFORE DRY WESTERLIES MOVE IN AHEAD OF AN UPPER
LEVEL TROUGH MOVING ASHORE OVER THE PACNW.
33
&&
.FIRE WEATHER...
CURRENT SATELLITE AND RADAR IMAGERY ARE SHOWING EVIDENCE OF THE
BACK DOOR COLD FRONT INVADING THE NORTHEAST PLAINS. EXPECT BREEZY TO
GUSTY NORTHEAST WINDS...WITH A SLIGHT INCREASE IN DEWPOINTS ACROSS
THE EXTREME EAST CENTRAL AND SOUTHEASTERN PLAINS...TO FOLLOW AS THE
FRONT HEADS TOWARD THE RGV. OTHERWISE...ANY SHOWER CHANCES COULD
FAVOR THE SOUTH CENTRAL MOUNTAINS...EAST CENTRAL AND NORTHEAST
PLAINS THIS AFTERNOON INTO THE EVENING HOURS. OVERNIGHT RECOVERIES
WILL BE FAIR TO GOOD CENTRAL AND EAST.
GAP WINDS ALONG THE CENTRAL MOUNTAINS WILL START INCREASING AROUND
MIDNIGHT AS THE BACK DOOR COLD FRONT APPROACHES FROM THE EAST.
TEMPERATURES ACROSS THE EAST WILL FALL BELOW NORMAL SATURDAY AS MIN
RH VALUES INCREASE EAST TO WEST OF THE CENTRAL MOUNTAIN CHAIN.
SHOWER CHANCES COULD FORM ALONG THE MOUNTAIN CHAIN WITH FOCUS ACROSS
THE SOUTHERN TIER OF THE STATE. MEANWHILE...EAST GAP WINDS COULD
REACH 35 TO 45 MPH WITHIN THE RGV EARLY SATURDAY BEFORE TAPERING
DOWN AND WASHING OUT BECOMING SOUTHEASTERLY BY THE AFTERNOON.
LOOK FOR TEMPERATURES TO REBOUND SUNDAY AS THEY CREEP BACK TO NEAR
AND ABOVE NORMAL READINGS. RESIDUAL MOISTURE WILL LINGER ACROSS THE
SOUTHERN TIER OF THE STATE WHERE SHOWER CHANCES WILL REMAIN. MIN RH
VALUES AND DEWPOINTS WILL DOWNTREND ACROSS THE NORTHERN HALF OF THE
STATE AS DRIER AIR FILTERS IN FROM NORTHWEST FLOW ALOFT.
BY MONDAY...MODELS ARE IN AGREEMENT OF AN UPPER LEVEL SYSTEM OVER
THE EASTERN PACIFIC HEADING NORTHEASTWARD...FOLLOWING UPPER LEVEL
RIDGING OVER TEXAS AND OLD MEXICO...HELPING TO USHER IN TROPICAL
MOISTURE ACROSS THE WESTERN HALF OF THE STATE FROM THE BAJA
PENINSULA. THE ONLY MODEL DIFFERENCE FOR MONDAY IS THAT MOISTURE
LEVELS ARE HIGHER ACROSS THE WEST IN GFS THAN THE EURO MODEL. BY
TUESDAY...GFS HAS A WELL DEFINED UPPER LEVEL SHORTWAVE TRAVELING
SOUTHWEST TO NORTHEAST ACROSS THE STATE...INCREASING SCATTERED TO
WIDESPREAD PRECIPITATION CHANCES ACROSS MUCH OF THE STATE WHILE THE
EURO MODEL HAS SOME SHORTWAVE ACTIVITY ARRIVING A BIT LATER THAN THE
GFS. BY MIDWEEK...GFS HAS PRECIPITATION FAVORING THE CENTRAL AND
SOUTH CENTRAL MOUNTAINS WHILE THE EURO MODEL HAS PRECIPITATION MORE
WIDESPREAD.
VENT RATES WILL BECOME POOR CENTRAL AND EAST WHILE IMPROVING NORTH
AND WEST OF THE CONTINENTAL DIVIDE ON SATURDAY...THEN BECOMING POOR
SOUTH AND WEST OF THE CENTRAL MOUNTAINS WITH IMPROVEMENTS NORTH AND
EAST ON SUNDAY. RATES WILL BECOME GOOD TO EXCELLENT IN THE EAST
MONDAY AND TUESDAY.
&&
.AVIATION...
18Z TAF CYCLE
ISOLATED SHOWERS AND THUNDERSTORMS WILL BE LIMITED IN
ACTIVITY...MAINLY FAVORING THE SOUTH CENTRAL MOUNTAINS...THE EAST
CENTRAL PLAINS AND NORTHEAST HIGHLANDS. ADDED VCSH FOR KROW
AROUND 23Z BECAUSE OF HRRR MODELS INDICATING SH ACTIVITY IN THE
AREA. COULD EXPECT GUSTY AND ERRATIC WINDS WITH ANY STORMS.
OTHERWISE...LOOK FOR ANOTHER AFTERNOON OF BREEZY TO GUSTY WEST TO
NORTHWEST WINDS ALONG THE CENTRAL MOUNTAIN CHAIN EASTWARD...WITH
HIGHER GUSTS IN THE EAST CENTRAL PLAINS. A BACK DOOR COLD FRONT
WILL PUSH ACROSS THE NORTHEAST PLAINS TOWARD THE RGV LATE TONIGHT
INTO EARLY SATURDAY BRINGING GUSTY EAST...NORTHEAST WINDS WITH IT.
GAP WINDS COULD REACH NEAR AWW CRITERIA FOR KABQ EARLY SATURDAY
WITH GUSTS REACHING 30 TO 35 KTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 46 85 46 86 / 0 0 0 0
DULCE........................... 29 77 32 79 / 0 5 0 0
CUBA............................ 47 73 46 77 / 5 5 5 0
GALLUP.......................... 39 84 42 85 / 0 0 0 0
EL MORRO........................ 40 76 40 78 / 10 5 10 5
GRANTS.......................... 42 80 40 82 / 10 5 5 0
QUEMADO......................... 49 79 52 79 / 5 20 10 20
GLENWOOD........................ 52 80 53 79 / 5 20 10 30
CHAMA........................... 39 70 41 73 / 0 5 0 0
LOS ALAMOS...................... 54 75 53 79 / 5 10 10 5
PECOS........................... 50 69 52 76 / 10 10 10 5
CERRO/QUESTA.................... 47 73 46 76 / 5 0 5 0
RED RIVER....................... 41 64 42 67 / 10 5 5 0
ANGEL FIRE...................... 46 64 48 68 / 10 10 5 5
TAOS............................ 43 76 42 81 / 5 0 5 0
MORA............................ 47 67 48 75 / 10 10 10 5
ESPANOLA........................ 48 82 47 85 / 0 0 5 0
SANTA FE........................ 53 75 54 80 / 5 0 5 5
SANTA FE AIRPORT................ 52 78 51 83 / 5 0 5 5
ALBUQUERQUE FOOTHILLS........... 60 79 60 85 / 5 5 10 5
ALBUQUERQUE HEIGHTS............. 62 81 61 86 / 5 0 5 5
ALBUQUERQUE VALLEY.............. 58 83 58 88 / 5 0 5 5
ALBUQUERQUE WEST MESA........... 59 82 58 87 / 5 0 5 0
LOS LUNAS....................... 54 86 54 89 / 5 0 5 0
RIO RANCHO...................... 59 82 58 87 / 5 0 5 0
SOCORRO......................... 60 87 59 90 / 10 0 10 5
SANDIA PARK/CEDAR CREST......... 52 73 53 81 / 5 10 10 5
TIJERAS......................... 56 75 56 83 / 5 10 10 5
MORIARTY/ESTANCIA............... 52 74 43 83 / 10 10 5 5
CLINES CORNERS.................. 49 69 52 80 / 10 10 5 5
GRAN QUIVIRA.................... 53 75 55 80 / 10 10 10 5
CARRIZOZO....................... 58 79 57 82 / 10 20 10 10
RUIDOSO......................... 52 68 54 74 / 10 40 20 30
CAPULIN......................... 48 69 50 78 / 10 5 5 0
RATON........................... 50 77 49 85 / 10 5 0 0
SPRINGER........................ 50 77 49 85 / 10 5 0 0
LAS VEGAS....................... 48 71 48 83 / 10 10 5 5
CLAYTON......................... 51 73 55 86 / 10 5 5 5
ROY............................. 50 71 52 84 / 10 5 0 5
CONCHAS......................... 58 80 58 91 / 5 5 5 5
SANTA ROSA...................... 57 79 58 89 / 5 5 5 5
TUCUMCARI....................... 58 78 59 92 / 10 5 5 5
CLOVIS.......................... 58 74 58 87 / 10 10 5 5
PORTALES........................ 60 75 61 86 / 10 10 10 5
FORT SUMNER..................... 61 77 60 88 / 5 10 5 5
ROSWELL......................... 63 82 63 90 / 10 20 10 5
PICACHO......................... 59 76 57 84 / 10 20 20 20
ELK............................. 57 67 57 75 / 10 20 20 30
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1157 AM MDT FRI SEP 18 2015
.AVIATION...
18Z TAF CYCLE
ISOLATED SHOWERS AND THUNDERSTORMS WILL BE LIMITED IN
ACTIVITY...MAINLY FAVORING THE SOUTH CENTRAL MOUNTAINS...THE EAST
CENTRAL PLAINS AND NORTHEAST HIGHLANDS. ADDED VCSH FOR KROW
AROUND 23Z BECAUSE OF HRRR MODELS INDICATING SH ACTIVITY IN THE
AREA. COULD EXPECT GUSTY AND ERRATIC WINDS WITH ANY STORMS.
OTHERWISE...LOOK FOR ANOTHER AFTERNOON OF BREEZY TO GUSTY WEST TO
NORTHWEST WINDS ALONG THE CENTRAL MOUNTAIN CHAIN EASTWARD...WITH
HIGHER GUSTS IN THE EAST CENTRAL PLAINS. A BACK DOOR COLD FRONT
WILL PUSH ACROSS THE NORTHEAST PLAINS TOWARD THE RGV LATE TONIGHT
INTO EARLY SATURDAY BRINGING GUSTY EAST...NORTHEAST WINDS WITH IT.
GAP WINDS COULD REACH NEAR AWW CRITERIA FOR KABQ EARLY SATURDAY
WITH GUSTS REACHING 30 TO 35 KTS.
&&
32
.PREV DISCUSSION...330 AM MDT FRI SEP 18 2015...
.SYNOPSIS...
HIGHS WILL BE NEAR TO A FEW DEGREES ABOVE AVERAGE WEST AND ABOVE
NORMAL EAST AGAIN TODAY. EASTERN AND SOUTHERN AREAS WILL HAVE THE
BEST...BUT ONLY SLIGHT CHANCES FOR SHOWERS AND STORMS TODAY AND
TONIGHT. SATURDAY AFTERNOON TEMPERATURES WILL BE COOLER CENTRAL AND
EAST DUE TO A COLD FRONT...WHICH IS EXPECTED TO BRING GUSTY WINDS TO
PORTIONS OF THE RIO GRANDE VALLEY TONIGHT AND SATURDAY. WARMER
SUNDAY AND MONDAY...BUT MOISTURE WILL BEGIN TO INCREASE AS AN UPPER
LOW OFF BAJA CALIFORNIA STARTS A NORTHEASTWARD TREK TO THE GREAT
BASIN. CONVECTION COULD BE FAIRLY WIDESPREAD TUESDAY INTO WEDNESDAY
BEFORE A DRYING TREND LATE NEXT WEEK.
&&
.DISCUSSION...
MOSTLY TWEAKS TO INHERITED FORECAST GRIDS. UPPER JET APPARENTLY
PRODUCING MAINLY SCATTERED CLOUDS ACROSS CENTRAL NM AND MAY LINGER
THROUGH THE DAY. MOSTLY ISOLD CONVECTION EXPECTED THIS AFTERNOON
SOUTH AND EAST. HIGHS WEST REMAIN NEAR TO ABOVE AVERAGE WITH THE
EAST ABOVE NORMAL BUT NOT QUITE AS WARM IN RECENT DAYS. KROW
FORECAST HIGH WITHIN 2-4 DEG OF THE RECORD FOR TODAY...WHILE
INCOMING FRONT SHOULD KEEP CLAYTON OUT OF THE 90S. FRONTAL TIMING
MAY BE SLIGHTLY SLOWER...BUT NOT BY MUCH. GUSTY NORTHEAST WINDS WILL
ACCOMPANY THE FRONT AS IT PLUNGES INTO THE EAST CENTRAL PLAINS THIS
EVENING...AND GUSTY EAST WINDS TO AROUND 40 MPH ARE EXPECTED INTO
THE RGV LATER TONIGHT AND SATURDAY MORNING. NAM12 INDICATES SOME
INSTAB DEVELOPING NR/ALONG THE CONTDVD AS THE FRONT PROGRESSES
WWD...THEREFORE SPREAD SOME LOW PROBABILITY POPS FOR TONIGHT AND
SATURDAY OVER THIS REGION. HIGHS IN THE EAST SATURDAY WILL BE BELOW
AVERAGE...NEAR AVERAGE CENTRAL...WITH NOT MUCH COOLING...IF AT
ALL...FAR WEST.
TEMPERATURES RECOVER SUNDAY AS THE UPPER HIGH REBOUNDS. INCREASING
MOISTURE WILL INVADE NM FROM THE SOUTH EARLY NEXT WEEK AS AN UPPER
LOW OFF BAJA CA TRACKS INTO THE GREAT BASIN. ECMWF GENERALLY HAS
SAME IDEA THOUGH NOT AS WET OR QUITE AS FAST. LATE NEXT WEEK A
DRYING TREND IS FORECAST AS THE UPPER HIGH REBUILDS YET AGAIN.
&&
.FIRE WEATHER...
UPPER LEVEL FEATURES DEFINING THE WEATHER PATTERN WILL BE EVOLVING
TODAY INTO THE WEEKEND. TODAY...A PROGRESSIVE SHORT WAVE TROUGH WILL
RACE ACROSS WYOMING AND INTO THE GREAT PLAINS TO THE EAST. THIS WILL
KEEP FAIRLY STRONG WESTERLY FLOW ALOFT OVER NM TODAY. WHILE SOME
BATCHES OF CIRRUS CLOUDS ARE EXPECTED TO CONTINUE WORKING OVER THE
STATE...MID LEVEL LAYERS WILL BE QUITE DRY WITH SOME OF THIS
EXPECTED TO MIX DOWN TO THE SURFACE THIS AFTERNOON. IN
FACT...MINIMUM HUMIDITY WILL FALL BELOW 15 PERCENT IN MANY AREAS
THIS AFTERNOON. SOME BREEZY CONDITIONS WILL IMPACT THE CENTRAL
MOUNTAINS AND HIGHLANDS...BUT OTHERWISE WIND SPEEDS WILL BE MARKEDLY
LESS THAN THE PAST FEW DAYS. TEMPERATURES WILL BE A FEW DEGREES
ABOVE AVERAGE IN THE WESTERN ZONES TODAY...BUT CONTINUED WARM TO HOT
AT 8 TO 12 DEGREES ABOVE AVERAGE IN THE EASTERN PLAINS OF NM. WINDS
WILL BEGIN SHIFTING IN THE NORTHEAST CORNER OF THE STATE LATE IN THE
AFTERNOON AS A FRONT ADVANCES CLOSER.
THE STRONGER FRONTAL PUSH SHOULD INVADE JUST BEFORE
SUNSET...SPILLING THROUGH THE REMAINDER OF THE PLAINS THROUGH THE
EVENING AND DRIVING BEYOND THE RIO GRANDE RIVER AFTER MIDNIGHT.
GUSTY WINDS WILL ACCOMPANY THE FRONTAL PASSAGE...BUT IT WILL ALSO
INDUCE WINDY CONDITIONS THROUGH GAPS/CANYONS WITHIN THE CENTRAL
MOUNTAIN CHAIN TONIGHT AND INTO SATURDAY MORNING.
WINDS WILL STEADILY DIMINISH TOWARD NOON WITH DIRECTIONS VEERING
SOUTHERLY IN MOST ZONES. SOME MEAGER MOISTURE ADVECTION WILL
ACCOMPANY THE FRONT IN THE LOWER LAYERS OF THE ATMOSPHERE...BUT THIS
IS NOT EXPECTED TO HELP THE CAUSE FOR STORM DEVELOPMENT MUCH INTO
SATURDAY. DESPITE SOME UPSLOPE FLOW...STORMS WILL LIKELY STAY
ISOLATED AND SPARSE OVER THE EAST CENTRAL PLAINS AND CENTRAL
MOUNTAIN CHAIN SATURDAY WITH A BIT MORE SCATTERED ACTIVITY FARTHER
WEST OVER THE CENTRAL DIVIDE AND INTO THE GILA. TEMPERATURES WILL BE
SET BACK TO AVERAGE OVER THE CENTRAL ZONES ON SATURDAY WITH READINGS
RUNNING 3 TO 8 DEGREES BELOW NORMAL IN THE EASTERN PLAINS OF NM.
INTO SUNDAY...LOW LAYER MOISTURE POOLING OVER OLD MEXICO AND THE
BORDERLAND WILL SEEP NORTHWARD...BUT STILL STORMS WILL BE FAIRLY
ISOLATED WITH THE EXCEPTION OF THE GILA IN FIRE WEATHER ZONE 109.
TEMPERATURES WOULD REBOUND TO 3 TO 7 DEGREES ABOVE NORMAL AREA WIDE
SUNDAY AFTERNOON.
THERE IS POTENTIAL FOR MORE STORM ACTIVITY MONDAY...BUT MORE-SO INTO
THE MID WEEK PERIOD AS SUBTROPICAL MOISTURE IS SQUEEZED BETWEEN AN
EASTERN PACIFIC LOW AND HIGH PRESSURE OVER TX. FORECAST MODELS ARE
STILL NOT COMPLETELY AGREEABLE ON EXACT PLACEMENT OF THE MOISTURE
PLUME...AND THE GFS REMAINS MORE ASSERTIVE WITH THE PLUME ARRIVAL
INTO CENTRAL TO WESTERN NM. THE CURRENT FORECAST CALLS FOR SCATTERED
STORMS IN THE CENTRAL TO WESTERN ZONES TUESDAY THROUGH THURSDAY.
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1258 PM EDT FRI SEP 18 2015
.SYNOPSIS...
LOW PRESSURE ABOUT 120 MILES EAST OF JACKSONVILLE FLORIDA WILL MOVE
SLOWLY NORTHEASTWARD OVER THE NEXT FEW DAYS. THIS LOW MAY ACQUIRE
SUBTROPICAL CHARACTERISTICS AS IT REMAINS OVER VERY WARM WATER. A
COLD FRONT WILL MOVE SLOWLY ACROSS THE AREA SUNDAY NIGHT...THEN
SHOULD STALL OFFSHORE THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM FRIDAY...THIS MORNING`S WAVE OF SHOWERS HAS COMPLETELY
DISSIPATED. AS THE SUN HEATS THE AIRMASS ALONG THE COAST A SECOND
ROUND MAY DEVELOP OVER THE NEXT FEW HOURS. THE LATEST FEW HRRR RUNS
SHOW 3-5 PM AS THE MOST LIKELY WINDOW FOR REDEVELOPMENT TO OCCUR...
WITH IDEAS ABOUT INLAND MOVEMENT AND COVERAGE SIMILAR TO THE EARLIER
DISCUSSION COPIED BELOW. NOONTIME TEMPERATURES WERE A LITTLE HIGHER
THAN ANTICIPATED SO I HAVE TWEAKED A FEW INLAND LOCATIONS (FLORENCE
& LUMBERTON) TO 88 DEGREES FOR AFTERNOON HIGHS. DISCUSSION FROM 1030
AM FOLLOWS...
LOW PRESSURE IS DEVELOPING ABOUT 120 MILES EAST OF JACKSONVILLE
FLORIDA THIS MORNING. THIS IS ALONG THE LOCATION OF A SURFACE TROUGH
THAT HAS EXTENDED ACROSS FLORIDA INTO THE NE GULF OF MEXICO FOR THE
PAST SEVERAL DAYS. NE WINDS ARE BRINGING ATLANTIC MOISTURE ONSHORE
IN THE LOWEST LEVELS OF THE ATMOSPHERE...BUT MUCH LIKE YESTERDAY
THERE IS A TIGHT GRADIENT IN DEEPER MOISTURE THAT WILL LIMIT HOW FAR
WESTWARD CLOUDS AND SHOWERS CAN PENETRATE. PRECIPITABLE WATER VALUES
RANGE FROM AROUND 2 INCHES OVER THE GULF STREAM TO LESS THAN 1 INCH
WEST OF INTERSTATE 95.
MODELS SHOW BY EARLY AFTERNOON A SECOND WAVE OF SCATTERED SHOWERS
SHOULD BE TAKING SHAPE ALONG THE COAST. MY FORECAST POPS INDICATE
ABOUT 20-30 PERCENT COVERAGE OVER THE COASTAL COUNTIES...HIGHEST IN
THE SOUTHPORT AND GEORGETOWN VICINITY. THINNER MOISTURE PROFILES
INLAND SHOULD LIMIT THE WESTERNMOST EXTENT OF ANY POSSIBLE SHOWERS
TO BURGAW...WHITEVILLE...AND CONWAY.
THE BIGGEST CHANGES TO THE FORECAST WERE TO REDUCE CLOUD COVER
FORECASTS TO SUNNY/MOSTLY SUNNY ALONG THE INTERSTATE 95 CORRIDOR AND
REDUCE POPS TO NEAR ZERO. FORECAST SOUNDINGS SUGGEST ONLY FLAT
CUMULUS DEVELOPING DURING THE HEAT OF THE DAY AS INSUFFICIENT
BOUNDARY LAYER MOISTURE SHOULD EXIST TO OVERCOME WARM MID-LEVEL
TEMPERATURES. HIGH TEMPERATURE FORECASTS HAVE ALSO BEEN BUMPED UP 1-
2 DEGREES FROM FLORENCE...DILLON AND LUMBERTON WESTWARD. SOME UPPER
80S ARE POSSIBLE IN THESE AREAS. ONLY MINOR CHANGES NEEDED CLOSER TO
THE COAST.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...THE PERSISTENT LOW PRESSURE BOTH AT THE SURFACE AND
ALOFT WILL STILL BE IN PLACE AT THE BEGINNING OF THE PERIOD. MODELS
HAVE JOGGED THE GENERATED QPF FURTHER TO THE EAST AND SATURDAY IS
BEGINNING TO LOOK MORE LIKE A DRY DAY WITH SOME CLOUD COVER. THE
SYSTEM CURRENTLY OVER THE CENTRAL PLAINS WILL KICK THE SYSTEM OUT TO
THE EAST LATE SATURDAY AND SUNDAY LEAVING ESSENTIALLY NO THREAT FOR
RAINFALL. SOME DECENT DOWNSLOPING ALOFT WILL WARM TEMPERATURES
DRAMATICALLY FOR SUNDAY WITH HIGHS IN THE MIDDLE TO UPPER 80S.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...THE EXTENDED PERIOD LOOKS SOMEWHAT UNSETTLED AS MID
LEVEL LOW PRESSURE CUTS OFF IN THE TENNESSEE VALLEY AND MEANDERS
AROUND THE SOUTHEAST THROUGH THE PERIOD. AS IS TYPICAL WITH A CUTOFF
SYSTEM...MODELS ARE HAVING DIFFICULTY FROM CYCLE TO CYCLE WITH THE
PLACEMENT OF THE FEATURE. AT THE SURFACE...HIGH PRESSURE WILL BE
CENTERED WELL TO THE NORTHEAST BUT EXTEND ITS INFLUENCE WELL TO THE
SOUTH. BASED ON THE UNCERTAINTY...I CONTINUE TO ADVERTISE POPS EACH
DAY WITH TUESDAY AND WEDNESDAY HAVING THE BEST CHANCE. NO REAL
CHANGES TO THE TEMPERATURE FORECAST AND TRENDS WITH HIGHS IN THE
LOWER 80S BEYOND MONDAY AND LOWS MAINLY IN THE MIDDLE 60S. THE
DIURNAL RANGE WILL BE LIMITED SOMEWHAT BY THE CLOUDS AND SHOWERS.
MONDAY WILL BE SLIGHTLY WARMER.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 18Z...TERMINALS ARE VFR THIS AFTERNOON. TEMPO LOW VFR CIGS ARE
OCCURRING AT THE COASTAL TERMINALS AND WILL CONTINUE TO DO SO
THROUGH THE AFTERNOON. WINDS ARE NE-ENE AT 10-15 KT WITH SOME HIGHER
GUSTS. SHOWERS ARE MOSTLY OFFSHORE AND CURRENT MOVEMENT SUGGESTS
THEY WILL REMAIN OFFSHORE. THERE WILL CONTINUE TO BE A POTENTIAL
HOWEVER FOR VCSH AT THE COASTAL TERMINALS THIS AFTERNOON WITH PLENTY
OF LOW LEVEL MOISTURE. A DRY AIRMASS ALOFT SHOULD LIMIT WIDESPREAD
DEVELOPMENT.
VFR AS WINDS AND LOWER CLOUDS DECREASE THIS EVENING. OVERNIGHT
CLOUDS WILL BE ON THE INCREASE AGAIN AT THE COASTAL TERMINALS WITH
AN INCREASING CHANCE OF SHOWERS AS LOW PRESSURE MOVES NE JUST
OFFSHORE. WINDS WILL INCREASE AND BACK TO THE NE-N BY DAYBREAK.
THERE IS A CHANCE OF HEAVIER SHOWERS AND LOWER CIGS BUT CONFIDENCE
IS LOW ATTM DUE TO DIFFERENCES IN MODEL TRACKS OF THE LOW PRESSURE
AREA..
EXTENDED OUTLOOK...COASTAL SHOWERS ARE POSSIBLE THROUGH SATURDAY
OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM FRIDAY...ALTHOUGH NOONTIME OBSERVATIONS WERE ONLY
AROUND 15 KNOTS...GUSTS WITHIN THE PAST COUPLE OF HOURS HAVE REACHED
22 KNOTS AT BOTH WRIGHTSVILLE BEACH AND MYRTLE BEACH. WINDS SHOULD
CONTINUE TO SLOWLY INCREASE THROUGH THE AFTERNOON AND EVENING.
DISCUSSION FROM 1030 AM FOLLOWS...
LOW PRESSURE IS TAKING SHAPE ABOUT 120 MILES EAST OF JACKSONVILLE
FLORIDA. THE TROUGH THIS LOW INTERSECTS HAS BEEN PRESENT FOR SEVERAL
DAYS AND HAS HELPED TO TIGHTEN THE PRESSURE GRADIENT ALONG THE
GA/SC/NC COAST AS OLD CANADIAN HIGH PRESSURE REMAINS ACROSS THE MID-
ATLANTIC REGION. MODELS SHOW A GRADUAL STRENGTHENING OF WIND SPEEDS
THROUGH THE AFTERNOON HOURS... APPROACHING A SOLID 20 KNOTS BY THIS
EVENING. A SMALL CRAFT ADVISORY HAS ALREADY BEEN ISSUED AND WILL
CONTINUE INTO SATURDAY.
A CONVERGENT BOUNDARY LIES FROM JUST SOUTH OF BALD HEAD ISLAND
SOUTHWESTWARD TO NEAR WINYAH BAY. THIS APPEARS TO BE LAST NIGHT`S
LANDBREEZE BOUNDARY SCULPTED BY PREVAILING NORTHEASTERLY WINDS.
SHOWERS HAVE DEVELOPED ALONG THIS BOUNDARY SINCE BEFORE SUNRISE...
AND WE WILL WATCH THIS AREA CLOSELY FOR MORE SHOWERS THROUGH THE
LATE MORNING AND AFTERNOON HOURS. WITH PLENTY OF MOISTURE AND LACK
OF WIND SHEAR IN THE LOWEST 8000 FEET OF THE ATMOSPHERE AND
SUFFICIENT INSTABILITY WE WILL ALSO WATCH FOR THE POTENTIAL OF
WATERSPOUT DEVELOPMENT.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...FAIRLY STRONG NORTHEAST WINDS OF 20-25 KNOTS
WILL BE ONGOING ACROSS ALL WATERS EARLY SATURDAY. WILL KEEP THE
SMALL CRAFT ADVISORY GOING UNTIL 1800 UTC AS SEAS SHOULD BE REACHING
SIX FEET AS WELL. THE WINDS DIMINISH BY SATURDAY EVENING AS LOW
PRESSURE MOVES WELL OFFSHORE. BY SUNDAY WINDS WILL BE NORTH TO
NORTHEAST AT A MORE MANAGEABLE 10-15 KNOT RANGE. SEAS WILL DROP TO 2-
4 FEET.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 300 AM FRIDAY...NORTHEAST WINDS OF 10-15 KNOTS WILL BE PREVALENT
THROUGH THE PERIOD AS HIGH PRESSURE RESIDES WELL TO THE NORTH. SOME
CONVECTION COULD DISRUPT THE WIND FIELDS FROM TIME TO TIME AS WELL
AS EMBEDDED NORTHEAST SURGES. SIGNIFICANT SEAS WILL BE 2-4 FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT SATURDAY FOR AMZ250-252-
254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS NORMAN OK
107 PM CDT FRI SEP 18 2015
.DISCUSSION...
SEE AVIATION
&&
.AVIATION...
A COLD FRONT INTERACTING WITH AN UPPER LEVEL STORM SYSTEM WILL
PRODUCE A NORTHERLY WIND SHIFT ACROSS ALL TERMINALS, AS WELL A FEW
PERIODS OF TSRA AND MFVR TO IFR CONDITIONS. THE COLD FRONT HAS
ALREADY PUSHED INTO FAR NORTHWEST OKLAHOMA, WHICH WILL BE
AFFECTING TERMINALS KWWR AND KGAG THE NEXT FEW HOURS. ISOLATED
TSRA WILL CONTINUE TO DEVELOP AHEAD OF THE FRONTAL BOUNDARY, WITH
MORE WIDESPREAD TSRA, POSSIBLY SEVERE, EXPECTED ALONG AND BEHIND
THE BOUNDARY AS WE PROGRESS THROUGH THE EVENING HOURS. TSRA POPS
SHOULD BE DECREASING FROM NORTH TO SOUTH ACROSS OKLAHOMA AND NORTH
TEXAS TOWARD THE END OF THE FORECAST PERIOD.
&&
.PREV DISCUSSION... /ISSUED 1103 AM CDT FRI SEP 18 2015/
UPDATE...
UPDATED PRECIP/WX THROUGH THE AFTN/EVENING...
DISCUSSION...
CONVECTION THIS MORNING HAS BEEN A BIT MORE AGGRESSIVE THAN
PREVIOUSLY ANTICIPATED. THIS ACTIVITY CONTINUES TO BE DRIVEN BY A
SUBTLE LOW LEVEL BAROCLINIC ZONE... MARKED BY A CORRIDOR OF
925-850 THETA E ADVECTION FROM FAR WRN N TX INTO NORTH CENTRAL OK.
UPPER LEVEL SUPPORT HAS BEEN PROVIDED BY A SHORT WAVE CURRENTLY
MOVING ACROSS NERN NM INTO THE PANHANDLES... WELL VISUALIZED ON
WV. 16Z SFC ANALYSIS HAS THE COLD FRONT KNOCKING ON THE DOOR IN
NWRN OK... AND IS EXPECTED TO START TO PUSH S/SE BY NOON. BIG
QUESTION AT THE MOMENT IS WHAT... IF ANY... RESIDUAL IMPACT EXISTS
FROM CURRENT CONVECTION ON ATMOSPHERIC RECOVERY THIS AFTN.
MESOSCALE GUIDANCE FROM THE HRRR HAS STRUGGLE OVER THE PAST TWO
HRS WITH THE CURRENT CONVECTION... WITH THE 12Z NAM HAVING A
SLIGHTLY BETTER GRASP WITH ITS CONV PRECIP. AT PRESENT... AHEAD OF
THE CURRENT CONVECTION... DPTS REMAIN POOLED IN THE UPPER
60S/LOWER 70S ACROSS CENTRAL OK AND TEMPS HAVE ALREADY REACHED THE
LOW/MID 80S THROUGH 16Z. THEREFORE... STILL ANTICIPATE A SECOND
ROUND OF CONVECTION AS THE FRONT PUSHES ACROSS THE STATE THIS AFTN
AND EVENING. THE PRIMARY HAZARDS WILL BE DAMAGING WINDS... 70 TO
80 MPH AND FREQUENT LIGHTNING. HAIL UP TO GOLF BALL SIZE WILL ALSO
BE POSSIBLE. STORMS WILL BECOME MORE LINEAR THROUGH THE EVENING...
WITH THE SEVERE HAZARDS SLOWLY DIMINISHING THROUGH MIDNIGHT AS
THEY MOVE INTO SOUTHERN OKLAHOMA... TOWARDS THE RED RIVER.
IF YOU HAVE OUTDOOR PLANS TONIGHT... SUCH AS HIGH SCHOOL FOOTBALL
OR THE OKLAHOMA STATE FAIR... SCOUT OUT GOOD SHELTER LOCATIONS
WHEN YOU ARRIVE AT YOUR VENUE... BLEACHERS AND LIGHTNING DO NOT
MIX. DO NOT WAIT TO SEEK SHELTER WHEN YOU SEE LIGHTNING... WHEN
THUNDER ROARS... GO IN DOORS.
JTK
PREV DISCUSSION... /ISSUED 617 AM CDT FRI SEP 18 2015/
DISCUSSION...
PLEASE SEE THE 12Z AVIATION DISCUSSION BELOW.
AVIATION...
A FEW SHOWERS AND STORMS WILL BE POSSIBLE NEAR CSM THIS MORNING.
LATER THIS EVENING...A COLD FRONT WILL MOVE INTO OK. SHOWERS AND
STORMS WILL INCREASE ALONG THIS COLD FRONT FROM NEAR WWR TO PNC
AND THEN SPREAD SOUTHWARD OVER MOST OF THE OTHER TERMINALS LATER
TONIGHT. EXACT TIMING AND COVERAGE ARE STILL QUESTIONABLE SO WILL
INCLUDE PROB30 GROUPS FOR THOSE TERMINALS WHERE THERE ARE STILL
SOME UNCERTAINTIES. EXPECT GUSTY SOUTH WINDS LATE THIS MORNING
THROUGH THIS AFTERNOON...WITH NORTH WINDS FOLLOWING THE FRONT
LATER TONIGHT.
PREV DISCUSSION... /ISSUED 449 AM CDT FRI SEP 18 2015/
DISCUSSION...
SHOWERS AND THUNDERSTORMS HAVE DEVELOPED NEAR THE FRONT EARLY
THIS MORNING ACROSS SOUTH CENTRAL AND SE KS. A FEW WEAK ECHOES
HAVE ALSO DEVELOPED NEAR WOODWARD. ISOLATED SHOWERS/STORMS WILL
BE POSSIBLE BEFORE SUNRISE ACROSS N/NW OK BUT VERY LITTLE RAINFALL
IS ANTICIPATED. LATER THIS MORNING A WEAK MID TO UPPER LEVEL
SHORTWAVE MOVING OUT OF NM WILL RESULT IN SUBTLE HEIGHT FALLS
ACROSS OK. SHOWER AND THUNDERSTORM COVERAGE MAY INCREASE A BIT WITH
THIS FEATURE JUST AHEAD OF THE FRONT BEFORE LUNCHTIME. DEPENDING
ON COVERAGE...THIS MAY RESULT IN A DIFFICULT TEMP FORECAST AHEAD
OF THE FRONT THIS AFTERNOON AS IT MOVES INTO NW OK. THE MORNING
ACTIVITY WILL ALSO HAVE AN IMPACT ON POTENTIAL INSTABILITY FOR
THIS AFTERNOON. FOR NOW...IT APPEARS A NARROW AXIS OF INSTABILITY
WILL DEVELOP ALONG THE FRONT LATE THIS AFTERNOON/EARLY THIS
EVENING FROM JUST WEST OF PNC TO CAMARGO. MID LEVEL LAPSE RATES
DO NOT APPEAR THEY WILL BE OVERLY IMPRESSIVE...IN ADDITION TO
EFFECTIVE DEEP SHEAR...SO SIGNIFICANT HAIL CHANCES APPEAR LOW.
DAMAGING WINDS UP TO 70 MPH...HOWEVER...WILL BE POSSIBLE GIVEN
HIGH LCLS/DRY SUB CLOUD LAYER. THE MOST LIKELY TIMING FOR SEVERE
WIND GUSTS WILL BE AROUND 5PM-MIDNIGHT AS SFC CONVERGENCE
INCREASES ALONG OF THE FRONT NEAR THE I44 CORRIDOR. AT LEAST ONE
MCS APPEARS POSSIBLE THROUGH LATE TONIGHT AS LOW LEVEL SHEAR
INCREASES.
THE FRONT WILL CONTINUE INTO NORTH TX EARLY SAT AM...AND LIKELY
BECOME STATIONARY THROUGH NORTH CENTRAL TX SATURDAY. RAIN CHANCES
WILL SHIFT ACROSS THE SOUTHERN ZONES SATURDAY AND THEN LIFT
NORTHWARD SUN AM MAINLY ALONG AND SOUTH OF I40. POPS WILL LINGER
ACROSS THE CENTRAL AND E/SE ZONES THROUGH EARLY MONDAY ALONG A SFC
TROUGH. FINALLY...BY TUESDAY...THE SUBTROPICAL RIDGE WILL BEGIN TO
BUILD BACK OVER THE SOUTHERN PLAINS RESULTING IN A WARM UP AND
DECREASING/LITTLE RAIN CHANCES THROUGH THE REST OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 94 64 77 60 / 50 80 20 30
HOBART OK 95 65 77 61 / 50 80 30 50
WICHITA FALLS TX 98 70 83 65 / 20 50 40 40
GAGE OK 89 57 76 56 / 40 30 10 30
PONCA CITY OK 89 59 75 55 / 70 70 10 20
DURANT OK 95 71 84 66 / 0 40 30 30
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
04/26/67
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
310 PM EDT FRI SEP 18 2015
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN PLACE THROUGH TOMORROW. A COLD FRONT
WILL MOVE INTO THE CAROLINAS FROM THE NORTH ON SUNDAY WITH
PRECIPITATION CHANCES INCREASING FOR SUNDAY AND MONDAY. COOLER
TEMPERATURES WILL ALSO RETURN ON MONDAY...WITH PERIODIC CHANCES FOR
PRECIPITATION CONTINUING INTO THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 230 PM EDT...THE 500 MB RIDGE AXIS OVER THE SRN APPALACHIANS
TONIGHT WILL SLOWLY BREAK DOWN FROM THE NORTHWEST ON SATURDAY AS THE
NORTHERN TIER BELT OF WESTERLIES SPREADS SOUTHWARD. THE SURFACE HIGH
OVER THE FORECAST AREA WILL GET INCREASINGLY PINCHED OVERHEAD
BETWEEN LOW PRESSURE OVER THE COASTAL WATERS AND A COLD FRONT
APPROACHING FROM THE OH VALLEY. PROFILES OVER OUR AREA WILL STAY
RELATIVELY DRY...ALTHOUGH THE NAM AND RAP DO INDICATE PATCHY LOWER
STRATUS TRYING TO MAKE A RUN WESTWARD FROM THE COAST INTO THE
PIEDMONT OVERNIGHT. MOST CLOUDINESS THROUGH THE PERIOD...HOWEVER...
SHOULD BE CONFINED MAINLY TO EARLY MORNING MOUNTAIN VALLEY STRATUS
AND THEN A FEW DAYTIME CUMULUS WITH HEATING SATURDAY AFTERNOON.
TEMPERATURES WILL CONTINUE TO REBOUND...WITH MINS AT LEAST A
CATEGORY ABOVE CLIMO THROUGHOUT OVERNIGHT...AND TWO TO THREE
CATEGORIES ABOVE CLIMO FOR MAX TEMPS SATURDAY AFTERNOON.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 245 PM...A DISTURBANCE WILL REMAIN OFF THE CAROLINA COAST
THROUGH THE SHORT RANGE...RESULTING IN LITTLE CHANGE TO THE SENSIBLE
WEATHER OVER THE CWA. ON SUNDAY...A WEAK COLD FRONT WILL SWEEP FROM
THE NORTHWEST...LIKELY REMAINING WEST OF THE FA BY SUNSET. SKY COVER
WILL INCREASE ACROSS THE SOUTHERN APPALACHIAN REGION THROUGH THE
DAY. LITTLE TO NO INSTABILITY AND NO FORCING SHOULD RESULT IN DRY
WEATHER ON SUNDAY. HIGH TEMPERATURES SHOULD RANGE FROM THE L80S
WITHIN THE MTN VALLEYS TO THE U80S EAST.
THE WEAK COLD FRONT WILL LIKELY HANG OVER THE SOUTHERN APPALACHIANS
EARLY MONDAY MORNING. THE CENTER OF SFC HIGH PRESSURE OVER NEW
ENGLAND...THE RIDGE OVER THE REGION ON MONDAY. THE GFS INDICATE THAT
WEAK 300 K ISENTROPIC LIFT WILL DEVELOP ACROSS THE REGION DURING THE
DAYLIGHT HOURS...SUPPORTED BY LLVL SE FLOW. THE COMBINATION OF
ISENTROPIC LIFT...LIGHT UPSLOPE FLOW...AND WIDESPREAD WEAK
INSTABILITY SHOULD RESULT IN AN EXPANDING AREA OF SHRA/TSRA ON
MONDAY. THICK CLOUDS...RAINFALL...AND DEVELOPING NE SFC WINDS WILL
FAVOR HIGH TEMPERATURES BELOW THE MOS CONSENSUS. I WILL FORECAST
HIGH TEMPERATURES FROM THE L70S WITHIN THE MTN VALLEYS TO THE L80S
ACROSS THE LAKELANDS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 210 PM FRIDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON TUESDAY
WITH AN UPPER TROF AXIS JUST TO OUR WEST AND UPPER RIDGING OVER THE
WESTERN CONUS. OVER THE NEXT COUPLE OF DAYS...THE TROF IS EXPECTED
TO SLOWLY MOVE OVER THE FCST AREA AND MORPH INTO A CLOSED UPPER LOW
BY LATE WED. THE LONG RANGE MODELS KEEP THE LOW SPINNING OVER THE SE
REGION INTO FRI WITH BROAD SCALE UPPER RIDGING SPREADING FARTHER
EAST OVER THE SAME PERIOD. IT IS NOTABLE THAT THE LATEST 12Z RUN OF
THE GFS DOES TRY TO MAINTAIN THE CLOSED LOW ABOUT 24 TO 48 HRS
LONGER THAN THE OLDER RUN OF THE ECWMF. AT THE SFC...CANADIAN HIGH
PRESSURE WILL BE SLIDING OFF THE NEW ENGLAND COAST BY EARLY TUES
WITH A BROAD LOW CENTERED JUST OFF THE CAROLINA COAST. THE EVOLUTION
OF THE SFC PATTERN REMAINS FAIRLY UNCLEAR AT THIS POINT...WITH SIG
DIFFERENCES BETWEEN THE LONG RANGE MODELS. THE GFS AND THE CMC KEEP
THE LOW JUST OFFSHORE WELL INTO THURS WITH ANOTHER CANADIAN HIGH
SLIDING EASTWARD IN THE WAKE OF THE PREVIOUS SFC HIGH. THE LOW
EVENTUALLY DISSIPATES OVER THE CWFA BY FRI WITH AN EVEN STRONGER
HIGH MAKING ITS WAY SOUTHWARD AND TOWARDS THE GREAT LAKES BY THE END
OF THE PERIOD. ON THE OTHER HAND...THE ECMWF MOVES THE LOW UP THE
EAST COAST ON TUES AND THEN WELL OFFSHORE BY LATE WED ALL WHILE
KEEPING HIGH PRESSURE OVER THE FCST AREA THRU THE ENTIRE PERIOD.
AS FOR THE SENSIBLE FCST...MORE WEIGHT HAS BEEN PLACED ON A GFS TYPE
SOLUTION WITH THE BEST CHANCES FOR PRECIP DURING THE FIRST DAY OR 2
OF THE PERIOD. TEMPS APPEAR MORE CONSISTENT BETWEEN THE MODELS WITH
VALUES WARMING A FEW DEGREES THRU THE MEDIUM RANGE NEARING
CLIMATOLOGY VALUES FOR MID/LATE SEPT.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...TEMPERATURES AND DEWPOINTS ACROSS THE REGION WILL CONTINUE
TO SUPPORT MAINLY AFTERNOON FEW TO SCT VFR LEVEL CUMULUS DURING
HEATING THIS AFTERNOON AND AGAIN ON SATURDAY. THE NAM AND RAP
PROFILES SUGGEST THAT LOWER LEVEL STRATUS COULD MAKE A RUN WESTWARD
THROUGH THE PIEDMONT TOWARD THE AIRFIELD OVERNIGHT...BUT THIS IS NOT
SUPPORTED BY THE MOS...SO ONLY FEW020 WILL BE FEATURED IN THE TAF
TOWARD DAYBREAK. EXPECT CONTINUED NE FLOW LESS THAN 10 KT THROUGH
THE PERIOD.
ELSEWHERE...FEW TO SCT VFR LEVEL CUMULUS WILL PERSIST THROUGH THE
LATE AFTERNOON HOURS AND THEN REDEVELOP WITH HEATING LATE SATURDAY
MORNING. ANOTHER ROUND OF MOUNTAIN VALLEY STRATUS LOOKS LIKELY...BUT
KAVL LOW CLOUDS HAVE BEEN QUITE BRIEF THE PAST COUPLE OF MORNINGS IN
THIS AIRMASS. WILL THUS FEATURE JUST FEW TO SCT LOW STRATUS ALONG
WITH BRIEF MVFR FOG AROUND DAYBREAK...WITH NO RESTRICTIONS
ELSEWHERE. EXPECT MAINLY NE WINDS LESS THAN 10 KT ACROSS THE
FOOTHILLS...WITH MORE NRLY FLOW INTO THE FRENCH BROAD VALLEY AT KAVL.
OUTLOOK...MORNING MOUNTAIN VALLEY FOG AND LOW STRATUS WILL CONTINUE
SAT NIGHT INTO SUNDAY MORNING. A COLD FRONT WILL APPROACH FROM THE
NORTHWEST ON SUNDAY...AND A DEVELOPING MID LEVEL LOW MAY INCREASE
THE CHANCES OF LOW CLOUDS AND RAIN ACROSS THE REGION EARLY TO MIDDLE
NEXT WEEK.
CONFIDENCE TABLE...
19-01Z 01-07Z 07-13Z 13-18Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL MED 64% HIGH 100% LOW 59% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...HG
SHORT TERM...NED
LONG TERM...JPT
AVIATION...HG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
253 PM EDT FRI SEP 18 2015
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN PLACE THROUGH TOMORROW. A COLD FRONT
WILL MOVE INTO THE CAROLINAS FROM THE NORTH ON SUNDAY WITH
PRECIPITATION CHANCES INCREASING FOR SUNDAY AND MONDAY. COOLER
TEMPERATURES WILL ALSO RETURN ON MONDAY...WITH PERIODIC CHANCES FOR
PRECIPITATION CONTINUING INTO THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 230 PM EDT...THE 500 MB RIDGE AXIS OVER THE SRN APPALACHIANS
TONIGHT WILL SLOWLY BREAK DOWN FROM THE NORTHWEST ON SATURDAY AS THE
NORTHERN TIER BELT OF WESTERLIES SPREADS SOUTHWARD. THE SURFACE HIGH
OVER THE FORECAST AREA WILL GET INCREASINGLY PINCHED OVERHEAD
BETWEEN LOW PRESSURE OVER THE COASTAL WATERS AND A COLD FRONT
APPROACHING FROM THE OH VALLEY. PROFILES OVER OUR AREA WILL STAY
RELATIVELY DRY...ALTHOUGH THE NAM AND RAP DO INDICATE PATCHY LOWER
STRATUS TRYING TO MAKE A RUN WESTWARD FROM THE COAST INTO THE
PIEDMONT OVERNIGHT. MOST CLOUDINESS THROUGH THE PERIOD...HOWEVER...
SHOULD BE CONFINED MAINLY TO EARLY MORNING MOUNTAIN VALLEY STRATUS
AND THEN A FEW DAYTIME CUMULUS WITH HEATING SATURDAY AFTERNOON.
TEMPERATURES WILL CONTINUE TO REBOUND...WITH MINS AT LEAST A
CATEGORY ABOVE CLIMO THROUGHOUT OVERNIGHT...AND TWO TO THREE
CATEGORIES ABOVE CLIMO FOR MAX TEMPS SATURDAY AFTERNOON.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 245 PM...A DISTURBANCE WILL REMAIN OFF THE CAROLINA COAST
THROUGH THE SHORT RANGE...RESULTING IN LITTLE CHANGE TO THE SENSIBLE
WEATHER OVER THE CWA. ON SATURDAY...A WEAK COLD FRONT WILL SWEEP
FROM THE NORTHWEST...LIKELY REMAINING WEST OF THE FA BY SUNSET. SKY
COVER WILL INCREASE ACROSS THE SOUTHERN APPALACHIAN REGION THROUGH
THE DAY. LITTLE TO NO INSTABILITY AND NO FORCING SHOULD RESULT IN
DRY WEATHER ON SATURDAY. HIGH TEMPERATURES SHOULD RANGE FROM THE
L80S WITHIN THE MTN VALLEYS TO THE U80S EAST.
ON MONDAY...THE WEAK COLD FRONT WILL LIKELY HANG OVER THE SOUTHERN
APPALACHIANS EARLY MONDAY MORNING. THE CENTER OF SFC HIGH PRESSURE
OVER NEW ENGLAND...THE RIDGE OVER THE REGION ON MONDAY. THE GFS
INDICATE THAT WEAK 300 K ISENTROPIC LIFT WILL DEVELOP ACROSS THE
REGION DURING THE DAYLIGHT HOURS...SUPPORTED BY LLVL SE FLOW. THE
COMBINATION OF ISENTROPIC LIFT...LIGHT UPSLOPE FLOW...AND WIDESPREAD
WEAK INSTABILITY SHOULD RESULT IN AN EXPANDING AREA OF SHRA/TSRA ON
MONDAY. THICK CLOUDS...RAINFALL...AND DEVELOPING NE SFC WINDS WILL
FAVOR HIGH TEMPERATURES BELOW THE MOS CONSENSUS. I WILL FORECAST
HIGH TEMPERATURES FROM THE L70S WITHIN THE MTN VALLEYS TO THE L80S
ACROSS THE LAKELANDS.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AS OF 210 PM FRIDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON TUESDAY
WITH AN UPPER TROF AXIS JUST TO OUR WEST AND UPPER RIDGING OVER THE
WESTERN CONUS. OVER THE NEXT COUPLE OF DAYS...THE TROF IS EXPECTED
TO SLOWLY MOVE OVER THE FCST AREA AND MORPH INTO A CLOSED UPPER LOW
BY LATE WED. THE LONG RANGE MODELS KEEP THE LOW SPINNING OVER THE SE
REGION INTO FRI WITH BROAD SCALE UPPER RIDGING SPREADING FARTHER
EAST OVER THE SAME PERIOD. IT IS NOTABLE THAT THE LATEST 12Z RUN OF
THE GFS DOES TRY TO MAINTAIN THE CLOSED LOW ABOUT 24 TO 48 HRS
LONGER THAN THE OLDER RUN OF THE ECWMF. AT THE SFC...CANADIAN HIGH
PRESSURE WILL BE SLIDING OFF THE NEW ENGLAND COAST BY EARLY TUES
WITH A BROAD LOW CENTERED JUST OFF THE CAROLINA COAST. THE EVOLUTION
OF THE SFC PATTERN REMAINS FAIRLY UNCLEAR AT THIS POINT...WITH SIG
DIFFERENCES BETWEEN THE LONG RANGE MODELS. THE GFS AND THE CMC KEEP
THE LOW JUST OFFSHORE WELL INTO THURS WITH ANOTHER CANADIAN HIGH
SLIDING EASTWARD IN THE WAKE OF THE PREVIOUS SFC HIGH. THE LOW
EVENTUALLY DISSIPATES OVER THE CWFA BY FRI WITH AN EVEN STRONGER
HIGH MAKING ITS WAY SOUTHWARD AND TOWARDS THE GREAT LAKES BY THE END
OF THE PERIOD. ON THE OTHER HAND...THE ECMWF MOVES THE LOW UP THE
EAST COAST ON TUES AND THEN WELL OFFSHORE BY LATE WED ALL WHILE
KEEPING HIGH PRESSURE OVER THE FCST AREA THRU THE ENTIRE PERIOD.
AS FOR THE SENSIBLE FCST...MORE WEIGHT HAS BEEN PLACED ON A GFS TYPE
SOLUTION WITH THE BEST CHANCES FOR PRECIP DURING THE FIRST DAY OR 2
OF THE PERIOD. TEMPS APPEAR MORE CONSISTENT BETWEEN THE MODELS WITH
VALUES WARMING A FEW DEGREES THRU THE MEDIUM RANGE NEARING
CLIMATOLOGY VALUES FOR MID/LATE SEPT.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...TEMPERATURES AND DEWPOINTS ACROSS THE REGION WILL CONTINUE
TO SUPPORT MAINLY AFTERNOON FEW TO SCT VFR LEVEL CUMULUS DURING
HEATING THIS AFTERNOON AND AGAIN ON SATURDAY. THE NAM AND RAP
PROFILES SUGGEST THAT LOWER LEVEL STRATUS COULD MAKE A RUN WESTWARD
THROUGH THE PIEDMONT TOWARD THE AIRFIELD OVERNIGHT...BUT THIS IS NOT
SUPPORTED BY THE MOS...SO ONLY FEW020 WILL BE FEATURED IN THE TAF
TOWARD DAYBREAK. EXPECT CONTINUED NE FLOW LESS THAN 10 KT THROUGH
THE PERIOD.
ELSEWHERE...FEW TO SCT VFR LEVEL CUMULUS WILL PERSIST THROUGH THE
LATE AFTERNOON HOURS AND THEN REDEVELOP WITH HEATING LATE SATURDAY
MORNING. ANOTHER ROUND OF MOUNTAIN VALLEY STRATUS LOOKS LIKELY...BUT
KAVL LOW CLOUDS HAVE BEEN QUITE BRIEF THE PAST COUPLE OF MORNINGS IN
THIS AIRMASS. WILL THUS FEATURE JUST FEW TO SCT LOW STRATUS ALONG
WITH BRIEF MVFR FOG AROUND DAYBREAK...WITH NO RESTRICTIONS
ELSEWHERE. EXPECT MAINLY NE WINDS LESS THAN 10 KT ACROSS THE
FOOTHILLS...WITH MORE NRLY FLOW INTO THE FRENCH BROAD VALLEY AT KAVL.
OUTLOOK...MORNING MOUNTAIN VALLEY FOG AND LOW STRATUS WILL CONTINUE
SAT NIGHT INTO SUNDAY MORNING. A COLD FRONT WILL APPROACH FROM THE
NORTHWEST ON SUNDAY...AND A DEVELOPING MID LEVEL LOW MAY INCREASE
THE CHANCES OF LOW CLOUDS AND RAIN ACROSS THE REGION EARLY TO MIDDLE
NEXT WEEK.
CONFIDENCE TABLE...
19-01Z 01-07Z 07-13Z 13-18Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL MED 64% HIGH 100% LOW 59% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...HG
SHORT TERM...NED
LONG TERM...JPT
AVIATION...HG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
158 PM EDT FRI SEP 18 2015
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN PLACE THROUGH SATURDAY AHEAD OF AN
APPROACHING COLD FRONT ARRIVING LATE SUNDAY. PRECIPITATION CHANCES
WILL INCREASE SUNDAY...PEAKING TUESDAY AS THE FRONT LAYS OUT OVER
THE REGION. COOLER TEMPERATURES WILL RETURN MONDAY...AND PERIODIC
CHANCES FOR SHOWERS WILL CONTINUE INTO THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 145 PM EDT...THE 500 MB RIDGE AXIS OVER THE SRN APPALACHIANS
TONIGHT WILL SLOWLY BREAK DOWN FROM THE NORTHWEST ON SATURDAY AS THE
NRN TIER BELT OF WESTERLIES SPREADS SOUTHWARD. THE SURFACE HIGH OVER
THE FORECAST AREA WILL GET INCREASINGLY PINCHED OVERHEAD BETWEEN LOW
PRESSURE OVER THE COASTAL WATERS AND A COLD FRONT APPROACHING FROM
THE OH VALLEY. PROFILES OVER OUR AREA WILL STAY RELATIVELY
DRY...ALTHOUGH THE NAM AND RAP DO INDICATE PATCHY LOWER STRATUS
TRYING TO MAKE A RUN WESTWARD FROM THE COAST INTO THE PIEDMONT
OVERNIGHT. MOST CLOUDINESS THROUGH THE PERIOD...HOWEVER...SHOULD BE
CONFINED MAINLY TO EARLY MORNING MOUNTAIN VALLEY STRATUS AND THEN A
FEW DAYTIME CUMULUS WITH HEATING SATURDAY AFTERNOON. TEMPERATURES
WILL CONTINUE TO REBOUND...WITH MINS AT LEAST A CATEGORY ABOVE CLIMO
THROUGHOUT OVERNIGHT...AND TWO TO THREE CATEGORIES ABOVE FOR MAX
TEMPS SATURDAY AFTERNOON.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 300 AM...WHILE LOW PRESSURE DRIFTS NEWD ALONG THE CAROLINA
COAST SATURDAY...A DRY NORTHERLY FLOW WILL CONTINUE INTO THE CWFA. A
SHORTWAVE RIDGE INITIALLY WILL BE OVERHEAD...BUT THIS COLLAPSES AS A
TROUGH SWINGS ACRS THE GREAT LAKES. POOR LAPSE RATES AND DRY
CONDITIONS UNDER THE RIDGE WILL KEEP THE CWFA DRY SATURDAY. AS THE
TROUGH LIFTS FROM THE GREAT LAKES INTO ERN CANADA ITS ASSOCIATED COLD
FRONT WILL LAY OUT ACRS THE TENN VALLEY AND VIRGINIAS. THE FLOW TURNS
MORE NWLY NEAR THE SFC AND LAPSE RATES IMPROVE ENOUGH TO EXPECT SOME
DIURNAL CONVECTION MAY RESULT OVER THE MTNS. AS THE FRONT IMPINGES ON
THE MTNS SUNDAY NIGHT POPS CONTINUE...THOUGH THE FRONT WASHES OUT TO
SOME DEGREE. TEMPS REMAIN WELL ABOVE CLIMO BOTH DAYS...WITH SUNDAY
EXPECTED TO BE WARMER DUE TO HIGHER THICKNESSES DESPITE INCREASING
CLOUDS AHEAD OF THE FRONT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 200 AM FRI...UPPER TROUGH WILL DIG INTO THE SRN APPALACHIAN
REGION MON-TUE BEFORE CLOSED LOW CUTS OFF AT ITS BASE...REMAINING
OVER THE DEEP SOUTH THRU THE REMAINDER OF THE FCST PERIOD...POSSIBLY
DRIFTING WESTWARD. NEAR THE SFC THE EARLY WEEK FRONT WILL STALL JUST
NORTH OF THE AREA...THEN POSSIBLY BE FORCED DOWN AS A BACK-DOOR FRONT
TUE NIGHT BY BUILDING ANTICYCLONE OVER THE MIDWEST. LOW LEVEL WARM
ADVECTIVE FLOW CONTINUES OVER THE AREA WITH THE FRONT STALLED...BUT
ONCE IT PUSHES SOUTH THERE IS JUST VERY LITTLE UPGLIDE OCCURRING OVER
IT...AND MOISTURE REMAINS CONCENTRATED IN THE LOW LEVELS. MIDLEVEL
LAPSE RATES ARE PREDICTABLY STRONG WITH THE UPPER LOW OVERHEAD
MON-TUE...BUT MONDAY WARM ADVECTION ABOVE THE BOUNDARY LAYER COULD
LIMIT CONVECTIVE COVERAGE. POPS PEAK TUE AND TREND DOWNWARD THRU
MIDWEEK. DESPITE DRYING EASTERLY FLOW DOES CONTINUE WITH ENOUGH LOW
LEVEL MOISTURE TO JUSTIFY A LOW POP MENTION THRU THE END OF THE FCST.
MAX TEMPS WILL DIP A CATEGORY OR SO BELOW CLIMO TUE AND SLOWLY
REBOUND...WITH MINS REMAINING SLIGHTLY ABOVE CLIMO.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...TEMPERATURES AND DEWPOINTS ACROSS THE REGION WILL CONTINUE
TO SUPPORT MAINLY AFTERNOON FEW TO SCT VFR LEVEL CUMULUS DURING
HEATING THIS AFTERNOON AND AGAIN ON SATURDAY. THE NAM AND RAP
PROFILES SUGGEST THAT LOWER LEVEL STRATUS COULD MAKE A RUN WESTWARD
THROUGH THE PIEDMONT TOWARD THE AIRFIELD OVERNIGHT...BUT THIS IS NOT
SUPPORTED BY THE MOS SO ONLY FEW020 WILL BE FEATURED IN THE TAF.
EXPECT CONTINUED NE FLOW LESS THAN 10 KT THROUGH THE PERIOD.
ELSEWHERE...FEW TO SCT VFR LEVEL CUMULUS WILL PERSIST THROUGH THE
LATE AFTERNOON HOURS AND THEN REDEVELOP WITH HEATING LATE SATURDAY
MORNING. ANOTHER ROUND OF MOUNTAIN VALLEY STRATUS LOOKS LIKELY...BUT
KAVL LOW CLOUDS HAVE BEEN QUITE BRIEF THE PAST COUPLE OF MORNINGS IN
THIS AIRMASS. WILL THUS FEATURE JUST FEW TO SCT LOW STRATUS ALONG
WITH BRIEF MVFR FOG AROUND DAYBREAK...WITH NO RESTRICTIONS
ELSEWHERE. EXPECT MAINLY NE FLOW LESS THAN 10 KT ACROSS THE
FOOTHILLS...WITH MORE NRLY FLOW INTO THE FRENCH BROAD VALLEY AT
KAVL.
OUTLOOK...MORNING MOUNTAIN VALLEY FOG AND LOW STRATUS WILL CONTINUE
SAT NIGHT INTO SUNDAY MORNING. A COLD FRONT WILL APPROACH FROM THE
NORTHWEST ON SUNDAY...AND A DEVELOPING MID LEVEL LOW MAY INCREASE
THE CHANCES OF LOW CLOUDS AND RAIN ACROSS THE REGION EARLY TO MIDDLE
NEXT WEEK.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL MED 62% HIGH 100% MED 66% HIGH 88%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...WIMBERLEY
NEAR TERM...HG
SHORT TERM...WIMBERLEY
LONG TERM...WIMBERLEY
AVIATION...HG
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1230 PM CDT FRI SEP 18 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 432 AM CDT FRI SEP 18 2015
AT THE SURFACE THIS MORNING...THE LOW LEVEL FRONTAL BOUNDARY HAS
PUSHED WELL SOUTH OF THE AREA...BUT MID LEVEL FRONT REMAINS LOCKED
FROM NEBRASKA PANHANDLE ACROSS THE CWA. HAD CLEARED ENOUGH EARLIER
WITH DIMINISHED NORTHERLY WINDS TO ALLOW TEMPS INTO THE UPPER 40S TO
LOWER 50S IN ALL BUT FAR SOUTH...AND DEWPOINTS TO FALL TOWARD 40 TO
45 IN SIMILAR AREAS. THE LARGER SCALE FEATURES IMPACTING THE
NORTHERN PLAINS ARE THE MAIN UPPER TROUGH PUSHING ACROSS WYOMING...
JET DIGGING AROUND THE BASE OF THE TROUGH TOWARD NORTHERN
COLORADO/SOUTHERN WYOMING...AND SECONDARY JET WITH LEADING NORTHERN
STREAM TROUGH FROM THE NORTHERN PLAINS TOWARD SOUTHWEST ONTARIO.
INITIAL PRECIPITATION ACROSS SOUTH CENTRAL SD AT 08Z HAS BEEN
ATTEMPTING TO STREAM NORTHEAST ALONG MID LEVEL BOUNDARY...BUT THE
DRIER LOW LEVEL AIR IN PLACE HAS BEEN CHALLENGING THE APPROACH
ACROSS SOUTHEAST SOUTH DAKOTA. WILL CONTINUE TO BE AN ISSUE WITH
SPREAD THROUGH EARLY MORNING...BUT DID FIND A NEED TO SPEED UP THE
SPREAD A BIT OVER EARLIER FORECAST...WHICH LOOKS TO HEAD LARGELY
ALONG/SOUTH OF I 90 IN MUCH OF THE AREA. PRECIP BASED A BIT LOWER IN
THE FRONTAL REALM SHOULD START TO POP UP PER ALMOST ALL MODEL
SOLUTIONS EARLY THIS MORNING TOWARD I 80 IN NEBRASKA WHERE CAN SEE
GATHERING MOISTURE IN THE FORM OF STRATUS BAND. AS THIS AREA OF
SHOWERS AND STORMS ENHANCES WITH APPROACH OF LARGER SCALE FORCING.
SOME HIGHER BASED INSTABILITY PROFILES SHOW WEAK INSTABILITY ABOVE
775 HPA CREEPING TOWARD THE LOWER MISSOURI VALLEY AND PARTS OF NW
IA...AND HAVE ADDED IN ISOLATED THUNDER. FAIRLY STRONG DYNAMICS LOOK
TO TAKE DIRECT AIM ACROSS THE FSD CWA FROM VERY LATE MORNING IN THE
FAR WEST...SPREADING ACROSS THE AREA THROUGH THE AFTERNOON...
ESPECIALLY STRONG WITH PV ADVECTION. MODELS SIMILAR IN DEVELOPING
ANTICYCLONICALLY CURVED OUTFLOW JET THROUGH MIDDAY FROM NORTHERN
MINNESOTA TO NORTHEAST SOUTH DAKOTA... INDICATIVE OF DECENT LATENT
HEAT RELEASE IN THE FRONTAL ZONE. CONFIDENCE IN PRECIPITATION IS
FAIRLY HIGH...AND HAVE RAISED THE POPS IN THE MID LEVEL FRONTAL ZONE
ACROSS THE MID/NORTH CWA A BIT MORE. ALSO...DURING THE AFTERNOON
CLOSER TO THE CORE OF THE UPPER WAVE WHERE TEMPS ALOFT ARE A BIT
COOLER...EXPERIMENTAL HRRR AND A COUPLE OTHER OF CAMS INDICATED
DEVELOPMENT OF SHOWERY AREA ACROSS CENTRAL SD WHICH ROTATES EASTWARD
WITH SOME AT LEAST WEAK INSTABILITY AND POTENTIAL FOR A FEW 50 DBZ
CORES...SUGGESTING A LOWER END THUNDER THREAT AS WELL. THIS AREA
SHOULD BE SOMEWHAT MORE LIMITED TO AREAS WEST OF THE JAMES RIVER
DURING THE MIDDAY/AFTERNOON HOURS. IF COULD MANAGE TO GET A BIT MORE
DIURNAL SUPPORT TO HEATING...COULD HAVE ENOUGH INSTABILITY TO
PERHAPS SEE AN OUTSIDE THREAT OF SOME VERY SMALL HAIL IN THE LOWER
BRULE AREA DURING THE EARLY TO MID AFTERNOON. HOWEVER...AT THIS TIME
APPEARS THAT ABUNDANCE OF CLOUDS AND THE PRESENCE OF PRECIP WILL
HOLD BACK HIGHS ENOUGH...MAINLY UPPER 50S TO MID 60S ACROSS THE AREA.
SHORT WAVELENGTH OF THE FEATURE COMPLICATES THOUGHTS OF KEEPING A
BIT MORE EXTENDED MENTION OF PRECIP CHANCE...AS WOULD TEND TO FOCUS
A MUCH GREATER PORTION OF THE PRECIP AHEAD OF TROUGH AXIS WHICH IS
THROUGH ALL BUT THE FAR EAST BY 00Z. HOWEVER...WITH CHANCE FOR A BIT
OF PRECIP IN DEFORMATION NORTH OF AXIS AND AT THIS TIME...WILL ALSO
INTRODUCE TRAILING SMALL BAND OF LOWER POPS...BUT SHOULD BE QUICKLY
DISSIPATING WITH THE OVERWHELMING LARGE SCALE TREND TO SUBSIDENCE
AND DRYING...AND THUS PRECIP SHOULD NOT TRAVERSE MUCH REAL ESTATE
BEFORE FADING AWAY. WINDS SHOULD ALSO WORK TOWARD DIMINISHING... AND
WITH CLEARING...WILL SEE A FEW NEAR 40 READINGS INTO THE NORTHERN
CWA...WITH MID 40S SOUTHEAST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 432 AM CDT FRI SEP 18 2015
SATURDAY AND SUNDAY LOOK DRY AND QUIET. HIGH PRESSURE ON SATURDAY
MORNING WILL DRIFT SOUTHEAST THROUGH THE DAY...ALLOWING WINDS TO
BACK AND TURN A BIT MORE SOUTHERLY. EVEN WITH ABUNDANT SUNSHINE THE
COOL ENVIRONMENT WILL LIKELY ONLY SUPPORT HIGH TEMPERATURES IN THE
MID 60S TO LOWER 70S.
THE SOUTHERLY GRADIENT INCREASES A BIT SATURDAY NIGHT INTO SUNDAY
WHICH WILL BRING MILDER LOWS ON SUNDAY MORNING...MAINLY UPPER 40S TO
LOWER 50S AND WARMER HIGHS...MOSTLY MID 70S.
IN THE OUTER PERIODS(MONDAY THROUGH THURSDAY)...MODELS STILL IN
PRETTY GOOD AGREEMENT BRINGING FLAT RIDGING INTO THE AREA ON MONDAY
THEN GRADUALLY BUILDING THE RIDGE BEFORE SWINGING A PRETTY STRONG
WAVE INTO THE AREA WEDNESDAY INTO THURSDAY. TIMING OF THIS WAVE OF
COURSE A BIT DIFFERENT FROM MODEL TO MODEL BUT EACH MODEL DOES HAVE
THIS ENERGY WORKING INTO THE AREA OVER THAT 48 HOUR PERIOD. PLUS THE
CANADIAN AND ECMWF HINT AT THE WAVE COMING OUT IN A COUPLE OF PIECES
WHILE THE GFS IS MORE COMPACT AND COMES OUT IN ONE STRONG PIECE.
SO...LOOKING AT DRY CONDITIONS ON MONDAY AND TUESDAY WITH GRADUALLY
INCREASING CHANCES WEDNESDAY INTO THURSDAY. AT THIS TIME WOULD
PINPOINT WEDNESDAY NIGHT AS THE HIGHEST PROBABILITY OF SHOWERS AND
THUNDERSTORMS. TOO TOUGH TO CALL ON TIMING RIGHT NOW. WILL ALSO NEED
TO KEEP AN EYE OUT FOR THE POTENTIAL FOR SEVERE WEATHER WITH THIS
ACTIVITY. OTHERWISE TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL
WITH HIGHS IN THE 70S TO MID 80S AND LOWS IN THE MID 50S TO LOWER
60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1225 PM CDT FRI SEP 18 2015
CONDITIONS LOOK TO BE PRIMARILY VFR THROUGH THE TAF PERIOD.
HOWEVER AM A LITTLE WORRIED ABOUT RADIATIONAL FOG HERE AND THERE
LATE TONIGHT AND VERY EARLY SATURDAY CONSIDERING THE MOIST GROUND
OVER SOME LOCATIONS...LIGHT WINDS AND CLEAR SKIES. FOR NOW...
LEFT OUT THE MENTION OF FOG IN THE TAF SITES AS PREDICTING THIS
SCENARIO FOR A POINT LOCATION AT THIS TIME IS DIFFICULT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN
LONG TERM...08
AVIATION...MJ
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND SATURDAY
ISSUED AT 213 PM CDT FRI SEP 18 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW
PRESSURE GATHERING STRENGTH OVER KANSAS AS A SHORTWAVE TROUGH MOVES
EAST ACROSS THE NORTHERN PLAINS. SHOWERS AND STORMS ARE INCREASING
IN COVERAGE AHEAD OF THE LOW ACROSS IOWA AND FAR SOUTHERN MINNESOTA.
A SECONDARY NARROW BAND OF RAIN IS ALSO MOVING NORTHEAST OVER
WESTERN WI WITHIN A MID-LEVEL FGEN ZONE. LAST NITES COLD FRONT HAS
SETTLED FROM NORTHERN ILLINOIS TO NORTHEAST LOWER MICHIGAN...BUT
CLOUDS BEHIND THE FRONT HAVE LINGERED OVER EAST-CENTRAL WI THROUGH
EARLY THIS AFTERNOON. DO NOT THINK THESE CLOUDS WILL MOVE MUCH WITH
THE FRONT NEARLY STALLED. AS THE LOW MOVES NORTHEAST ALONG THE
FRONT...RAIN TIMING AND AMOUNTS ARE THE MAIN FORECAST CONCERNS.
TONIGHT...LOW PRESSURE WILL TRAVEL FROM THE MID-MISSISSIPPI VALLEY
TO CENTRAL LAKE HURON. ON THE NORTHERN SIDE OF THE LOW...FORCING IN
THE FORM OF MID-LEVEL FGEN AND UPPER DIVERGENCE WILL BE EXCELLENT.
A SECONDARY BAND OF FGEN WILL ALSO MOVE ACROSS NORTH-CENTRAL WI FOR
THE EVENING AHEAD OF THE MID-LEVEL SHORTWAVE THAT IS CURRENTLY OVER
THE NORTHERN PLAINS. SO ANTICIPATE THE MAIN BRUNT OF THE RAIN TO
PUSH NORTHEAST THIS EVENING FROM THE PLAINS AND SPREAD ACROSS MUCH
OF CENTRAL AND NORTHEAST WISCONSIN FROM MID-EVENING THROUGH THE
EARLY MORNING HOURS. THE SECONDARY BAND OF RAIN SHOULD ALSO IMPACT
NORTH-CENTRAL WI EARLY TO MID-EVENING BEFORE BEING OVERTAKEN BY THE
MAIN AREA OF RAIN. MID-LEVEL THETAE LAPSE RATES SUGGEST THE CHANCE
OF THUNDER IS RATHER LOW...BUT GIVEN THE MAGNITUDE OF THE
FORCING...WILL LEAVE A CHANCE OVER THE SOUTHEAST HALF OF THE
FORECAST AREA. RAINFALL AMOUNTS COULD BE RATHER BEEFY OVER EAST-
CENTRAL WI...POSSIBLY OVER AN INCH. BUT THE QUICK MOTION OF THE LOW
SUGGESTS THE CHANCE OF FLOODING IS TOO LOW TO MENTION. THE RAIN
WILL BE PULLING OUT LATE TONIGHT AND SOME CLEARING COULD ALREADY BE
MOVING INTO THE I-39/ROUTE 51 CORRIDOR BY 12Z. LOWS IN THE UPPER
40S TO MID 50S.
SATURDAY...WITH THE RAIN EXPECTED TO HAVE EXITED ACROSS THE REGION
EXCEPT FOR POSSIBLY THE DOOR...CLEARING SHOULD QUICKLY MOVE FROM
WEST TO EAST OVER THE COURSE OF THE MORNING. AMPLE SUNSHINE SHOULD
THEN RETURN FOR THE AFTERNOON WHEN HIGHS SHOULD REACH FROM THE MID
TO UPPER 60S.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ISSUED AT 213 PM CDT FRI SEP 18 2015
HIGH PRESSURE WILL DOMINATE THE FCST FOR THE END OF THE WEEKEND
AND BEGINNING OF THE NEXT WORK WEEK. WILL CONTINUE TO MENTION
PATCHY FOG LATE SATURDAY NIGHT...GIVEN RECENT RAIN...LIGHT WINDS
AND CLEAR SKIES. WILL LIKELY SEE A FEW SPOTS IN NORTH CENTRAL
WI DROP INTO THE UPPER 30S...AND WILL NEED TO MONITOR FOR PATCHY
FROST POTENTIAL WITH SUBSEQUENT FCSTS. EXPECT A GRADUAL WARMING
TREND AS SW WINDS DEVELOP AND INCREASE ON THE NW PERIPHERY OF THE
SFC HIGH.
MODELS ARE SHOWING A WEAK FRONT MEANDERING AROUND THE REGION FOR
THE REST OF THE WORK WEEK...PASSING THROUGH AS A COLD FRONT LATE
MONDAY NIGHT INTO TUESDAY...LIFTING BACK NORTH AS A WARM FRONT ON
WEDNESDAY...THEN RETURNING AS A COLD FRONT ON THURSDAY AND
THURSDAY NIGHT. SMALL CHANCES OF SHOWERS AND TSTMS ARE
ANTICIPATED...MOST NOTABLY OVER THE NW HALF OF THE FORECAST AREA.
TEMPERATURES SHOULD REMAIN ABOVE NORMAL FOR MOST OF THE PERIOD...
THEN RETURN TO NEAR NORMAL AT THE END OF THE WEEK.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 100 PM CDT FRI SEP 18 2015
MVFR CIGS OVER EAST-CENTRAL WI WILL IMPROVE BY MID-
AFTERNOON TO VFR THOUGH UNCERTAINTY IS HIGHER AT MTW DUE TO ITS
CLOSER PROXIMITY TO A COLD FRONT. LOW PRESSURE WILL TRACK ALONG
THIS COLD FRONT TONIGHT...BRINGING WIDESPREAD RAIN TO MUCH OF THE
REGION. THE HEAVIEST RAIN WILL OCCUR OVER EAST-CENTRAL AND
NORTHEAST WI WHERE IFR CONDITIONS ARE LIKELY. A QUICK IMPROVEMENT
IS EXPECTED LATE TONIGHT AS THE LOW PULLS OUT...LEAVING VFR
CONDITIONS ACROSS THE REGION BY MID-MORNING ON SATURDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......MPC