Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/28/13
AREA FORECAST DISCUSSION
NWS ALBANY NY
131 AM EDT SAT OCT 26 2013
.SYNOPSIS...
HIGHER PRESSURE WILL BUILD IN TODAY HOWEVER THIS WILL BE SHORT
LIVED AS A LOW PRESSURE SYSTEM APPROACHES FROM THE GREAT LAKES
REGION TONIGHT. THE SYSTEM WILL CROSS THE REGION SATURDAY AND
SATURDAY NIGHT BRINGING CLOUDS AND SOME RAIN AND SNOW SHOWERS TO
PORTIONS OF THE AREA...ESPECIALLY NORTH AND WEST OF THE CAPITAL
DISTRICT. HIGHER PRESSURE WILL BUILD BACK IN ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 120 AM EDT...HIGH PRESSURE NEAR THE TN VALLEY IS ATTEMPTING
TO RIDGE IN FROM THE SOUTH WITH MOSTLY CLEAR OR PARTLY CLOUDY
SKIES FROM THE CAPITAL DISTRICT SOUTH AND EAST. SOME LOW LEVEL
WARM ADVECTION IS INCREASING AHEAD OF THE SYSTEM APPROACHING FROM
SRN ONTARIO AND THE WESTERN GREAT LAKES REGION. THE BACKING WINDS
TO THE SOUTHWEST HAVE ALLOWED THE ISOLD SNOW AND RAIN SHOWERS TO
INCREASE NEAR THE TUG HILL PLATEAU AND THE WRN-CNTRL MOHAWK
VALLEY... AND A LAKE EFFECT BAND IS HAVING TROUBLE EXTENDING
DOWNSTREAM INTO THE WRN DACKS. THE LATEST 3KM HRRR CONTINUES TO
SHOW SOME SCATTERED PCPN INT THE WRN DACKS EARLY THIS MORNING.
THIS BAND LIFTS QUICKLY NORTHWARD WITH THE BACKING FLOW TO THE
W/SW.
THE BEST CHC OF LAKE ENHANCED SNOW SHOWERS OVERNIGHT WILL OCCUR
ACROSS MAINLY NRN HERKIMER AND HAMILTON COUNTIES. WE CONTINUED A
NARROW CORRIDOR OF CHANCE POPS ACROSS THESE AREAS DURING THE
OVERNIGHT WITH LESS THAN AN INCH OF ACCUMULATION.
TEMP TRENDS READJUSTED AGAIN BASED ON OBSERVATIONS THE PAST FEW
HOURS. LOWS TONIGHT WILL ONCE AGAIN BE COLD...BUT MODERATED A BIT
BY THE VARIABLE CLOUD COVER. LOWS TONIGHT WILL RANGE FROM THE U20S
TO M30S. THE WINDS CONTINUE TO DIMINISH...AND WILL BE LIGHT TO
CALM OVERNIGHT WITH SOME RADIATIONAL COOLING FROM THE HUDSON RIVER
VALLEY SOUTHWARD. MID LEVEL CLOUDS OVER WESTERN/CENTRAL NY WILL BE
ON THE INCREASE TOWARDS DAY BREAK INTO EASTERN NY AND WESTERN NEW
ENGLAND.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AT THE START OF THE WEEKEND...A PROGRESSIVE SHORTWAVE TROUGH WILL
BE DIVING QUICKLY SOUTHEASTWARD FROM THE GREAT LAKES
REGION...MOVING ACROSS THE FORECAST AREA SATURDAY INTO SATURDAY
NIGHT. OVERALL DYNAMICS LOOK WEAK WITH THIS MOISTURE-STARVED
SYSTEM...AS A WEAK AREA OF LOW PRESSURE AND ASSOCIATED COLD
FRONT PROVIDE JUST ENOUGH FORCING TO RESULT IN WIDELY SCATTERED
RAIN/SNOW SHOWERS ACROSS AREAS MAINLY NORTH AND WEST OF THE
CAPITAL DISTRICT. STRATO AND ALTOCUMULUS WILL ALSO QUICKLY
INCREASE DURING THE DAY SATURDAY RESULTING IN MOSTLY CLOUDY TO
CLOUDY SKIES.
SOUTH/SOUTHWEST WINDS WILL BECOME BREEZY DURING THE DAY SATURDAY
THANKS IN PART TO A TIGHT PRESSURE GRADIENT OVER THE REGION. WINDS
WILL GENERALLY BE 10 TO 20 MPH...WITH GUSTS UP TO 30-35 MPH
ESPECIALLY IN THE HUDSON RIVER VALLEY WHERE TERRAIN CHANNELING
WILL BE FAVORED. HIGHS SATURDAY WILL STILL BE ON THE COOL SIDE DUE
TO WIDESPREAD CLOUD COVER...GENERALLY TOPPING OUT NEAR 50 IN
VALLEY LOCATIONS AND STRUGGLING TO REACH THE UPPER 30S IN HIGHER
ELEVATIONS.
AS THE LOW PRESSURE SYSTEM DEPARTS TO THE EAST SATURDAY NIGHT THE
FORECAST AREA WILL REMAIN UNDER A BROAD CYCLONIC FLOW
ALOFT...PROMOTING CONTINUED MOSTLY CLOUDY SKIES ACROSS THE REGION
AIDED BY MOIST FLOW OFF OF LAKE ONTARIO. LOWS SATURDAY NIGHT WILL
RANGE FROM THE MID 30S IN VALLEY LOCATIONS TO UPPER 20S IN
PORTIONS OF THE ADIRONDACKS.
THE LOW-LEVEL FLOW WILL ORIENT TO THE SOUTHWEST SATURDAY NIGHT
THROUGH SUNDAY RESULTING IN RENEWED DEVELOPMENT OF SCATTERED LAKE
EFFECT RAIN/SNOW SHOWERS DEPENDING ON THE ELEVATION. THESE SHOWERS
WILL PRIMARILY BE TIED TO AREAS NORTH AND WEST OF THE CAPITAL
DISTRICT...ALTHOUGH A FEW SPRINKLES MAY BRIEFLY OCCUR DURING THE
DAY ACROSS THE CAPITAL DISTRICT AND CATSKILLS. WINDS WILL CONTINUE
TO BE GUSTY...ALTHOUGH NOT AS STRONG AS SATURDAY AROUND 10-15 MPH
WITH GUSTS UP TO 20 MPH. HIGHS SUNDAY WILL BE SLIGHTLY WARMER AS
THE LOW-LEVEL SOUTHWESTERLY FLOW RESULTS IN WEAK WARM AIR
ADVECTION...GENERALLY REACHING THE LOW 50S IN VALLEY LOCATIONS AND
LOW 40S IN THE HIGHER TERRAIN.
AN AREA OF HIGH PRESSURE WILL NUDGE ITS WAY ACROSS THE REGION
BEGINNING LATE SUNDAY...WITH A GRADUAL DECREASING TREND IN CLOUD
COVER AND WINDS. WITH THE DECREASING CLOUDS...LOWS SUNDAY NIGHT
WILL AGAIN DIP INTO THE MID 20S TO LOW 30S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
HIGH PRESSURE ON MONDAY WILL QUICKLY GIVE WAY TO A COLD FRONT WHICH
WILL WEAKEN AS HIGH PRESSURE ATTEMPTS TO WIN BACK CONTROL OF THE
REGION AT MID-WEEK. THE UNCERTAINTY RESULTING FROM THIS WEAK
PATTERN WILL MEAN A CHANCE FOR SHOWERS/SNOW SHOWERS FROM TUESDAY ON.
THE WEAK AND DIFFUSE FRONTAL BOUNDARY WILL BE HANGING AROUND OUR
FORECAST AREA TO ASSIST WITH THIS.
A MORE ORGANIZED COMPLEX OVER THE CENTER OF THE NATION ON THURSDAY
WILL HEAD UP TO THE GREAT LAKES REGION...BUT IT TOO WILL STRUGGLE TO
SURVIVE AS HIGH PRESSURE ONLY RELUCTANTLY GIVES WAY BY SLIDING OFF
THE EASTERN SEABOARD AT THE END OF THE WORK WEEK. BOTTOM LINE...
LOTS OF CLOUDS...AND PERIODS OF SHOWERS WITH LIGHT PRECIPITATION
AMOUNTS. WHERE SHOWERS OCCUR THROUGH WEDNESDAY NIGHT...HIGHER
ELEVATIONS WILL SEE SOME SNOW SHOWERS OR A MIX DURING THE EVENING
AND NIGHTTIME PERIODS. FRIDAY WILL BE MILDER THAN NORMAL WITH A
CHANCE OF RAIN.
TUESDAY HIGH TEMPERATURES WILL RANGE FROM THE UPPER 30S IN THE HIGH
PEAKS OF THE ADIRONDACKS AND GREENS...TO THE MID 60S IN THE MID
HUDSON VALLEY OF NEW YORK...AND SOUTHERN LITCHFIELD COUNTY
CONNECTICUT. WEDNESDAY WILL BE SLIGHTLY COOLER...AND THURSDAY
THROUGH FRIDAY WILL BECOME INCREASINGLY MILDER AS A MOIST SOUTHWEST
FLOW ENSUES. NIGHTTIME LOWS MONDAY THROUGH WEDNESDAY NIGHTS WILL BE
IN THE 20S AND 30S...WITH MOST LOCATIONS DIPPING BELOW FREEZING
DURING THE LAST OF THESE NIGHTS. THURSDAY NIGHT WILL AVERAGE ABOUT
10 TO 15 DEGREES WARMER.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
A LOW PRESSURE SYSTEM WILL IMPACT THE REGION TODAY INTO
TONIGHT...AS IT PASSES NORTH OF THE ST LAWRENCE VALLEY.
VFR CONDITIONS ARE EXPECTED THE NEXT 24 HOURS WITH MID AND HIGH
CLOUDS BECOMING PEDOMINANT. THE CEILING AROUND KPSF SHOULD HOVER
AROUND 3000 FEET THROUGH ABOUT 12Z. THE MID CLOUDS WILL LINGER
INTO THE AFTERNOON WITH THE STRENGTHENING WARM ADVECTION AHEAD OF
THE CLIPPER LIKE WAVE. SOME SPRINKLES ARE POSSIBLE LATE IN THE
AFTERNOON AND EVENING BUT NOT ENOUGH TO PUT VCSH IN ANY OF THE
TAFS. CEILINGS WILL BE INDICATED AS LOW VFR IN THE 5000 FOOT
RANGE...THOUGH THIS EVENING.
WINDS WILL BE LIGHT FROM THE SOUTH TO SOUTHWEST AT 5 KT OR LESS
DURING THE EARLY MORNING HOURS...THEN 5-12 KTS TOWARDS DAY
BREAK...THEN STRENGTHENING TO AROUND 15 KTS WITH GUSTS AROUND 25
KTS DUE TO FUNNELING UP THE HUDSON RIVER VALLEY...ESPECIALLY AT
KALB IN THE LATE MORNING/EARLY PM. WINDS WILL DIMINISH TO AROUND
6-12 KT THIS EVENING.
OUTLOOK...
SATURDAY-SATURDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF
SHRA.
SUNDAY-WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER ISSUES ARE EXPECTED OVER THE NEXT FIVE DAYS.
A LOW PRESSURE SYSTEM WILL QUICKLY APPROACH FROM THE GREAT LAKES
REGION AND MOVE ACROSS THE REGION SATURDAY AND SATURDAY NIGHT. THE
SYSTEM WILL BRING SCATTERED LIGHT RAIN AND SNOW
SHOWERS...ESPECIALLY NORTH AND WEST. HIGH PRESSURE WILL BUILD
ACROSS THE REGION FOR MONDAY.
RELATIVE HUMIDITIES WILL VARY BETWEEN 40 AND 60 PERCENT DURING THE
DAYTIME HOURS AND RECOVER TO BETWEEN 90 AND 100 PERCENT EACH
NIGHT. WESTERLY WINDS WILL BE GUSTY THIS WEEKEND BETWEEN 10-20 MPH
WITH GUSTS UP TO 30-35 POSSIBLE IN SOME LOCATIONS. COLD
TEMPERATURES AND NEAR NORMAL SOIL MOISTURE ANOMALIES WILL ALSO
INHIBIT FIRE WEATHER POTENTIAL OVER THE NEXT FIVE DAYS.
&&
.HYDROLOGY...
NO HYDRO ISSUES ARE ANTICIPATED INTO EARLY NEXT WEEK. OVERALL RIVER
AND STREAM LEVELS ARE NEAR TO SLIGHTLY BELOW NORMAL FOR LATE
OCTOBER. ONLY SOME LIGHT PRECIPITATION IS EXPECTED INTO EARLY NEXT
WEEK FROM A LOW PRESSURE SYSTEM THAT WILL APPROACH AND CROSS THE
REGION THIS WEEKEND AND FROM SOME LAKE EFFECT SHOWERS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IRL/WASULA
NEAR TERM...IRL/JPV/WASULA
SHORT TERM...IRL
LONG TERM...ELH
AVIATION...NAS
FIRE WEATHER...IRL
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
120 AM EDT SAT OCT 26 2013
.SYNOPSIS...
HIGHER PRESSURE WILL BUILD IN TODAY HOWEVER THIS WILL BE SHORT
LIVED AS A LOW PRESSURE SYSTEM APPROACHES FROM THE GREAT LAKES
REGION TONIGHT. THE SYSTEM WILL CROSS THE REGION SATURDAY AND
SATURDAY NIGHT BRINGING CLOUDS AND SOME RAIN AND SNOW SHOWERS TO
PORTIONS OF THE AREA...ESPECIALLY NORTH AND WEST OF THE CAPITAL
DISTRICT. HIGHER PRESSURE WILL BUILD BACK IN ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 120 AM EDT...HIGH PRESSURE NEAR THE TN VALLEY IS ATTEMPTING
TO RIDGE IN FROM THE SOUTH WITH MOSTLY CLEAR OR PARTLY CLOUDY
SKIES FROM THE CAPITAL DISTRICT SOUTH AND EAST. SOME LOW LEVEL
WARM ADVECTION IS INCREASING AHEAD OF THE SYSTEM APPROACHING FROM
SRN ONTARIO AND THE WESTERN GREAT LAKES REGION. THE BACKING WINDS
TO THE SOUTHWEST HAVE ALLOWED THE ISOLD SNOW AND RAIN SHOWERS TO
INCREASE NEAR THE TUG HILL PLATEAU AND THE WRN-CNTRL MOHAWK
VALLEY... AND A LAKE EFFECT BAND IS HAVING TROUBLE EXTENDING
DOWNSTREAM INTO THE WRN DACKS. THE LATEST 3KM HRRR CONTINUES TO
SHOW SOME SCATTERED PCPN INT THE WRN DACKS EARLY THIS MORNING.
THIS BAND LIFTS QUICKLY NORTHWARD WITH THE BACKING FLOW TO THE
W/SW.
THE BEST CHC OF LAKE ENHANCED SNOW SHOWERS OVERNIGHT WILL OCCUR
ACROSS MAINLY NRN HERKIMER AND HAMILTON COUNTIES. WE CONTINUED A
NARROW CORRIDOR OF CHANCE POPS ACROSS THESE AREAS DURING THE
OVERNIGHT WITH LESS THAN AN INCH OF ACCUMULATION.
TEMP TRENDS READJUSTED AGAIN BASED ON OBSERVATIONS THE PAST FEW
HOURS. LOWS TONIGHT WILL ONCE AGAIN BE COLD...BUT MODERATED A BIT
BY THE VARIABLE CLOUD COVER. LOWS TONIGHT WILL RANGE FROM THE U20S
TO M30S. THE WINDS CONTINUE TO DIMINISH...AND WILL BE LIGHT TO
CALM OVERNIGHT WITH SOME RADIATIONAL COOLING FROM THE HUDSON RIVER
VALLEY SOUTHWARD. MID LEVEL CLOUDS OVER WESTERN/CENTRAL NY WILL BE
ON THE INCREASE TOWARDS DAY BREAK INTO EASTERN NY AND WESTERN NEW
ENGLAND.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AT THE START OF THE WEEKEND...A PROGRESSIVE SHORTWAVE TROUGH WILL
BE DIVING QUICKLY SOUTHEASTWARD FROM THE GREAT LAKES
REGION...MOVING ACROSS THE FORECAST AREA SATURDAY INTO SATURDAY
NIGHT. OVERALL DYNAMICS LOOK WEAK WITH THIS MOISTURE-STARVED
SYSTEM...AS A WEAK AREA OF LOW PRESSURE AND ASSOCIATED COLD
FRONT PROVIDE JUST ENOUGH FORCING TO RESULT IN WIDELY SCATTERED
RAIN/SNOW SHOWERS ACROSS AREAS MAINLY NORTH AND WEST OF THE
CAPITAL DISTRICT. STRATO AND ALTOCUMULUS WILL ALSO QUICKLY
INCREASE DURING THE DAY SATURDAY RESULTING IN MOSTLY CLOUDY TO
CLOUDY SKIES.
SOUTH/SOUTHWEST WINDS WILL BECOME BREEZY DURING THE DAY SATURDAY
THANKS IN PART TO A TIGHT PRESSURE GRADIENT OVER THE REGION. WINDS
WILL GENERALLY BE 10 TO 20 MPH...WITH GUSTS UP TO 30-35 MPH
ESPECIALLY IN THE HUDSON RIVER VALLEY WHERE TERRAIN CHANNELING
WILL BE FAVORED. HIGHS SATURDAY WILL STILL BE ON THE COOL SIDE DUE
TO WIDESPREAD CLOUD COVER...GENERALLY TOPPING OUT NEAR 50 IN
VALLEY LOCATIONS AND STRUGGLING TO REACH THE UPPER 30S IN HIGHER
ELEVATIONS.
AS THE LOW PRESSURE SYSTEM DEPARTS TO THE EAST SATURDAY NIGHT THE
FORECAST AREA WILL REMAIN UNDER A BROAD CYCLONIC FLOW
ALOFT...PROMOTING CONTINUED MOSTLY CLOUDY SKIES ACROSS THE REGION
AIDED BY MOIST FLOW OFF OF LAKE ONTARIO. LOWS SATURDAY NIGHT WILL
RANGE FROM THE MID 30S IN VALLEY LOCATIONS TO UPPER 20S IN
PORTIONS OF THE ADIRONDACKS.
THE LOW-LEVEL FLOW WILL ORIENT TO THE SOUTHWEST SATURDAY NIGHT
THROUGH SUNDAY RESULTING IN RENEWED DEVELOPMENT OF SCATTERED LAKE
EFFECT RAIN/SNOW SHOWERS DEPENDING ON THE ELEVATION. THESE SHOWERS
WILL PRIMARILY BE TIED TO AREAS NORTH AND WEST OF THE CAPITAL
DISTRICT...ALTHOUGH A FEW SPRINKLES MAY BRIEFLY OCCUR DURING THE
DAY ACROSS THE CAPITAL DISTRICT AND CATSKILLS. WINDS WILL CONTINUE
TO BE GUSTY...ALTHOUGH NOT AS STRONG AS SATURDAY AROUND 10-15 MPH
WITH GUSTS UP TO 20 MPH. HIGHS SUNDAY WILL BE SLIGHTLY WARMER AS
THE LOW-LEVEL SOUTHWESTERLY FLOW RESULTS IN WEAK WARM AIR
ADVECTION...GENERALLY REACHING THE LOW 50S IN VALLEY LOCATIONS AND
LOW 40S IN THE HIGHER TERRAIN.
AN AREA OF HIGH PRESSURE WILL NUDGE ITS WAY ACROSS THE REGION
BEGINNING LATE SUNDAY...WITH A GRADUAL DECREASING TREND IN CLOUD
COVER AND WINDS. WITH THE DECREASING CLOUDS...LOWS SUNDAY NIGHT
WILL AGAIN DIP INTO THE MID 20S TO LOW 30S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
HIGH PRESSURE ON MONDAY WILL QUICKLY GIVE WAY TO A COLD FRONT WHICH
WILL WEAKEN AS HIGH PRESSURE ATTEMPTS TO WIN BACK CONTROL OF THE
REGION AT MID-WEEK. THE UNCERTAINTY RESULTING FROM THIS WEAK
PATTERN WILL MEAN A CHANCE FOR SHOWERS/SNOW SHOWERS FROM TUESDAY ON.
THE WEAK AND DIFFUSE FRONTAL BOUNDARY WILL BE HANGING AROUND OUR
FORECAST AREA TO ASSIST WITH THIS.
A MORE ORGANIZED COMPLEX OVER THE CENTER OF THE NATION ON THURSDAY
WILL HEAD UP TO THE GREAT LAKES REGION...BUT IT TOO WILL STRUGGLE TO
SURVIVE AS HIGH PRESSURE ONLY RELUCTANTLY GIVES WAY BY SLIDING OFF
THE EASTERN SEABOARD AT THE END OF THE WORK WEEK. BOTTOM LINE...
LOTS OF CLOUDS...AND PERIODS OF SHOWERS WITH LIGHT PRECIPITATION
AMOUNTS. WHERE SHOWERS OCCUR THROUGH WEDNESDAY NIGHT...HIGHER
ELEVATIONS WILL SEE SOME SNOW SHOWERS OR A MIX DURING THE EVENING
AND NIGHTTIME PERIODS. FRIDAY WILL BE MILDER THAN NORMAL WITH A
CHANCE OF RAIN.
TUESDAY HIGH TEMPERATURES WILL RANGE FROM THE UPPER 30S IN THE HIGH
PEAKS OF THE ADIRONDACKS AND GREENS...TO THE MID 60S IN THE MID
HUDSON VALLEY OF NEW YORK...AND SOUTHERN LITCHFIELD COUNTY
CONNECTICUT. WEDNESDAY WILL BE SLIGHTLY COOLER...AND THURSDAY
THROUGH FRIDAY WILL BECOME INCREASINGLY MILDER AS A MOIST SOUTHWEST
FLOW ENSUES. NIGHTTIME LOWS MONDAY THROUGH WEDNESDAY NIGHTS WILL BE
IN THE 20S AND 30S...WITH MOST LOCATIONS DIPPING BELOW FREEZING
DURING THE LAST OF THESE NIGHTS. THURSDAY NIGHT WILL AVERAGE ABOUT
10 TO 15 DEGREES WARMER.
&&
.AVIATION /05Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL BRIEFLY BUILD IN FROM THE SOUTH TONIGHT. A LOW
PRESSURE SYSTEM WILL IMPACT THE REGION TOMORROW INTO TOMORROW
NIGHT...AS IT PASSES NORTH OF THE ST LAWRENCE VALLEY.
VFR CONDITIONS ARE EXPECTED THE NEXT 24 HOURS WITH THE
STRATOCUMULUS DIMINISHING EARLY ON...BUT MID AND HIGH CLOUDS WILL
INCREASE AFTER MIDNIGHT. THE MID CLOUDS WILL LINGER INTO TOMORROW
AFTERNOON WITH THE STRENGTHENING WARM ADVECTION AHEAD OF THE
CLIPPER LIKE WAVE.
W/NW WINDS WILL BECOME LIGHT/VARIABLE PRIOR TO MIDNIGHT AT 4 KTS
OR LESS. THE WINDS WILL INCREASE FROM THE SOUTH TO SOUTHWEST AT
5-12 KTS TOWARDS DAY BREAK...THEN STRENGTHENING TO AROUND 15 KTS WITH
GUSTS AROUND 25 KTS DUE TO FUNNELING UP THE HUDSON RIVER
VALLEY...ESPECIALLY AT KALB IN THE LATE MORNING/EARLY PM.
OUTLOOK...
SATURDAY-SATURDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF
SHRA.
SUNDAY-WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER ISSUES ARE EXPECTED OVER THE NEXT FIVE DAYS.
A LOW PRESSURE SYSTEM WILL QUICKLY APPROACH FROM THE GREAT LAKES
REGION AND MOVE ACROSS THE REGION SATURDAY AND SATURDAY NIGHT. THE
SYSTEM WILL BRING SCATTERED LIGHT RAIN AND SNOW
SHOWERS...ESPECIALLY NORTH AND WEST. HIGH PRESSURE WILL BUILD
ACROSS THE REGION FOR MONDAY.
RELATIVE HUMIDITIES WILL VARY BETWEEN 40 AND 60 PERCENT DURING THE
DAYTIME HOURS AND RECOVER TO BETWEEN 90 AND 100 PERCENT EACH
NIGHT. WESTERLY WINDS WILL BE GUSTY THIS WEEKEND BETWEEN 10-20 MPH
WITH GUSTS UP TO 30-35 POSSIBLE IN SOME LOCATIONS. COLD
TEMPERATURES AND NEAR NORMAL SOIL MOISTURE ANOMALIES WILL ALSO
INHIBIT FIRE WEATHER POTENTIAL OVER THE NEXT FIVE DAYS.
&&
.HYDROLOGY...
NO HYDRO ISSUES ARE ANTICIPATED INTO EARLY NEXT WEEK. OVERALL RIVER
AND STREAM LEVELS ARE NEAR TO SLIGHTLY BELOW NORMAL FOR LATE
OCTOBER. ONLY SOME LIGHT PRECIPITATION IS EXPECTED INTO EARLY NEXT
WEEK FROM A LOW PRESSURE SYSTEM THAT WILL APPROACH AND CROSS THE
REGION THIS WEEKEND AND FROM SOME LAKE EFFECT SHOWERS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IRL/WASULA
NEAR TERM...IRL/JPV/WASULA
SHORT TERM...IRL
LONG TERM...ELH
AVIATION...WASULA
FIRE WEATHER...IRL
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1126 AM MDT SAT OCT 26 2013
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 253 AM MDT SAT OCT 26 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW NW FLOW OVER NORTHERN
PLAINS WITH POSITIVELY TILTED SHORTWAVE TROUGH EXTENDING SOUTH
ACROSS WESTERN KS AND OK/TX PANHANDLES. SUBSIDENCE IS BEGINNING TO
BUILD SOUTH INTO SW NE/NW KS ON POSITIVE SIDE OF PV HEIGHT ANOMALY
ASSOCIATED WITH SHORTWAVE. AT THE SURFACE A COLD FRONT IS CURRENTLY
ALONG THE NE/SD BORDER WITH A PREFRONTAL TROUGH OF LOW PRESSURE
ACROSS WESTERN. TIGHT GRADIENT IS BEGINNING TO BUILD INTO SW NE/NW
KS NORTH OF THE SURFACE TROUGH AXIS. VAD WINDS INDICATE 30-35 KT LLJ
IN PLACE OVER KGLD MATCHING RAP BL AND H85 WINDS. RADAR INDICATES
LIGHT RETURNS (LIKELY VIRGA) TRANSITIONING SOUTH AHEAD OF SURFACE
TROUGH AXIS SOUTH OF OUR CWA.
WITH SUBSIDENCE BUILDING SOUTH AND 30-35KT LLJ IN PLACE WE COULD SEE
A PERIOD OF GUSTY WINDS DEVELOP DURING THE MORNING HOURS...HOWEVER
GRADIENT SHOULD QUICKLY WEAKEN AS FRONT APPROACHES FROM THE NORTH BY
MIDDAY...SO WINDS SHOULD GENERALLY SHOW A DECREASING TREND THROUGH
THE DAY FROM THE NORTH TO THE SOUTH AFTER ABOUT 15Z. FRONT WILL
QUICKLY SWING SOUTH AND EAST...WITH THERMAL TROUGH BEGINNING TO
REDEVELOP THIS AFTERNOON IN THE WEST. RESULT WILL LIKELY BE TEMPS
NEAR OR SLIGHTLY COOLER THAN YESTERDAY IN THE UPPER 50S/LOW 60S.
FORECAST SHOULD REMAIN DRY AND MILD SUNDAY WITH SHORTWAVE RIDGE IN
PLACE...WITH HIGHS WARMING INTO 70S ACROSS CWA.
SUNDAY NIGHT-MONDAY NIGHT...PATTERN CHANGE IS STILL EXPECTED AS
UPPER LOW DROPS OUT OF PAC NW AND DEEPENS OVER THE SW CONUS...AND
COLD FRONT DROPS SOUTH INTO THE PLAINS STALLING SOUTH OF OUR CWA.
MODELS HAVE COME INTO REASONABLE AGREEMENT ON THE TIMING/EVOLUTION
OF THIS SYSTEM THROUGH MONDAY NIGHT...ALONG WITH COLD FRONT
PASSAGE SUNDAY NIGHT INTO MONDAY MORNING. THERE ARE SOME
DIFFERENCES REGARDING LOW LEVEL MOISTURE RETURN BEHIND THIS FRONT
ALONG WITH TIMING OF STRONGEST CAA...HOWEVER PICTURE REMAINS VERY
SIMILAR. CONSIDERING SHALLOW MOISTURE PROFILE ADVERTISED BY ALL
MODELS...THIS SHOULD BE A DRIZZLE/LIGHT PRECIP EVENT STARTING
MONDAY AFTERNOON THROUGH MONDAY NIGHT. BASED ON TEMP PROFILES BY
NAM/GFS/ECMWF I WOULD EXPECT PRECIP TO REMAIN LIQUID...WITH
FREEZING DRIZZLE POSSIBLE IN THE FAR NW PART OF THE CWA LATE MON
NIGHT AS SURFACE TEMPS HOVER AROUND 32F. WHILE A LIGHT GLAZE
COULDNT BE RULED OUT ON ELEVATED SURFACES FOR A FEW HOURS IN PARTS
OF YUMA COUNTY LATE MON NIGHT...THIS PROBABLY WONT NECESSITATE AN
ADVISORY CONSIDERING WARM GROUND/ROAD TEMPS AND BRIEF/LIGHT NATURE
OF THE FREEZING PRECIP.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 253 AM MDT SAT OCT 26 2013
AT THE START OF THE EXTENDED PERIOD...A SIGNIFICANT UPPER TROUGH
WILL BE POSITIONED ACROSS THE WESTERN CONUS. MODELS HAVE COME INTO
BETTER AGREEMENT IN RECENT RUNS AND CONTINUE TO SHIFT THE TRACK
NORTHWARD. THIS HAS NECESSITATED AN ADJUSTMENT IN PRECIPITATION TYPE
TO ALMOST ALL LIQUID PHASE. USING GFS FORECAST SOUNDINGS...WHICH
SHOULD GENERALLY REPRESENT A CONSENSUS OF MEDIUM RANGE MODELS
DESPITE SOME RELATIVELY MINOR DIFFERENCES IN POSITION AND CHARACTER
OF THE TROUGH...SHALLOW LOW LEVEL MOISTURE WOULD BE MOST SUPPORTIVE
OF A STRATUS...FOG AND/OR DRIZZLE SCENARIO EARLY TUESDAY. THIS WILL
OCCUR IN A MOIST EASTERLY/NORTHEASTERLY LOW LEVEL FLOW REGIME UNDER
RELATIVELY DRY SOUTHWESTERLY MID LEVEL FLOW. MOISTURE REMAINS
LIMITED IN DEPTH WEDNESDAY AND WEDNESDAY NIGHT RESULTING IN LIGHT
PRECIPITATION AMOUNTS AND POPS REMAIN IN THE SLIGHT CHANCE TO CHANCE
RANGE. THERMAL PROFILES ARE GENERALLY NOT SUPPORTIVE OF FROZEN
PRECIPITATION DURING THIS PERIOD...BUT MAY BECOME MARGINAL FOR AT
LEAST A MIX OF RAIN SNOW WEDNESDAY NIGHT IN THE FAR NORTHWEST.
CONFIDENCE IN THIS IS LOW HOWEVER...ESPECIALLY CONSIDERING THE NEW
ECMWF AND THE CONTINUED NORTHWARD TREND. A PROGRESSIVE UPPER FLOW
PATTERN WILL CONTINUE INTO LATE WEEK WITH UPPER LEVEL RIDGING
QUICKLY BUILDING ACROSS THE WESTERN HALF OF THE CONUS BY FRIDAY AND
NOTEWORTHY HEIGHT RISES OVER OUR AREA. IF MEDIUM RANGE GUIDANCE
SHOWS CONSISTENCY...THIS MAY REQUIRE A CONSIDERABLE UPWARD
ADJUSTMENT IN TEMPERATURES FOR LATE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1124 AM MDT SAT OCT 26 2013
HIGH PRESSURE OVER THE HIGH PLAINS WILL PROVIDE VFR CONDITIONS FOR
KGLD AND KMCK FOR THE DURATION OF THE TAF PERIOD. A LIGHT WIND
SHIFT WILL TAKE PLACE DURING THE EVENING HOURS...BECOMING
SOUTHWEST AROUND 3Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BRB
AVIATION...MK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
511 AM MDT SAT OCT 26 2013
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 253 AM MDT SAT OCT 26 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW NW FLOW OVER NORTHERN
PLAINS WITH POSITIVELY TILTED SHORTWAVE TROUGH EXTENDING SOUTH
ACROSS WESTERN KS AND OK/TX PANHANDLES. SUBSIDENCE IS BEGINNING TO
BUILD SOUTH INTO SW NE/NW KS ON POSITIVE SIDE OF PV HEIGHT ANOMALY
ASSOCIATED WITH SHORTWAVE. AT THE SURFACE A COLD FRONT IS CURRENTLY
ALONG THE NE/SD BORDER WITH A PREFRONTAL TROUGH OF LOW PRESSURE
ACROSS WESTERN. TIGHT GRADIENT IS BEGINNING TO BUILD INTO SW NE/NW
KS NORTH OF THE SURFACE TROUGH AXIS. VAD WINDS INDICATE 30-35 KT LLJ
IN PLACE OVER KGLD MATCHING RAP BL AND H85 WINDS. RADAR INDICATES
LIGHT RETURNS (LIKELY VIRGA) TRANSITIONING SOUTH AHEAD OF SURFACE
TROUGH AXIS SOUTH OF OUR CWA.
WITH SUBSIDENCE BUILDING SOUTH AND 30-35KT LLJ IN PLACE WE COULD SEE
A PERIOD OF GUSTY WINDS DEVELOP DURING THE MORNING HOURS...HOWEVER
GRADIENT SHOULD QUICKLY WEAKEN AS FRONT APPROACHES FROM THE NORTH BY
MIDDAY...SO WINDS SHOULD GENERALLY SHOW A DECREASING TREND THROUGH
THE DAY FROM THE NORTH TO THE SOUTH AFTER ABOUT 15Z. FRONT WILL
QUICKLY SWING SOUTH AND EAST...WITH THERMAL TROUGH BEGINNING TO
REDEVELOP THIS AFTERNOON IN THE WEST. RESULT WILL LIKELY BE TEMPS
NEAR OR SLIGHTLY COOLER THAN YESTERDAY IN THE UPPER 50S/LOW 60S.
FORECAST SHOULD REMAIN DRY AND MILD SUNDAY WITH SHORTWAVE RIDGE IN
PLACE...WITH HIGHS WARMING INTO 70S ACROSS CWA.
SUNDAY NIGHT-MONDAY NIGHT...PATTERN CHANGE IS STILL EXPECTED AS
UPPER LOW DROPS OUT OF PAC NW AND DEEPENS OVER THE SW CONUS...AND
COLD FRONT DROPS SOUTH INTO THE PLAINS STALLING SOUTH OF OUR CWA.
MODELS HAVE COME INTO REASONABLE AGREEMENT ON THE TIMING/EVOLUTION
OF THIS SYSTEM THROUGH MONDAY NIGHT...ALONG WITH COLD FRONT
PASSAGE SUNDAY NIGHT INTO MONDAY MORNING. THERE ARE SOME
DIFFERENCES REGARDING LOW LEVEL MOISTURE RETURN BEHIND THIS FRONT
ALONG WITH TIMING OF STRONGEST CAA...HOWEVER PICTURE REMAINS VERY
SIMILAR. CONSIDERING SHALLOW MOISTURE PROFILE ADVERTISED BY ALL
MODELS...THIS SHOULD BE A DRIZZLE/LIGHT PRECIP EVENT STARTING
MONDAY AFTERNOON THROUGH MONDAY NIGHT. BASED ON TEMP PROFILES BY
NAM/GFS/ECMWF I WOULD EXPECT PRECIP TO REMAIN LIQUID...WITH
FREEZING DRIZZLE POSSIBLE IN THE FAR NW PART OF THE CWA LATE MON
NIGHT AS SURFACE TEMPS HOVER AROUND 32F. WHILE A LIGHT GLAZE
COULDNT BE RULED OUT ON ELEVATED SURFACES FOR A FEW HOURS IN PARTS
OF YUMA COUNTY LATE MON NIGHT...THIS PROBABLY WONT NECESSITATE AN
ADVISORY CONSIDERING WARM GROUND/ROAD TEMPS AND BRIEF/LIGHT NATURE
OF THE FREEZING PRECIP.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 253 AM MDT SAT OCT 26 2013
AT THE START OF THE EXTENDED PERIOD...A SIGNIFICANT UPPER TROUGH
WILL BE POSITIONED ACROSS THE WESTERN CONUS. MODELS HAVE COME INTO
BETTER AGREEMENT IN RECENT RUNS AND CONTINUE TO SHIFT THE TRACK
NORTHWARD. THIS HAS NECESSITATED AN ADJUSTMENT IN PRECIPITATION TYPE
TO ALMOST ALL LIQUID PHASE. USING GFS FORECAST SOUNDINGS...WHICH
SHOULD GENERALLY REPRESENT A CONSENSUS OF MEDIUM RANGE MODELS
DESPITE SOME RELATIVELY MINOR DIFFERENCES IN POSITION AND CHARACTER
OF THE TROUGH...SHALLOW LOW LEVEL MOISTURE WOULD BE MOST SUPPORTIVE
OF A STRATUS...FOG AND/OR DRIZZLE SCENARIO EARLY TUESDAY. THIS WILL
OCCUR IN A MOIST EASTERLY/NORTHEASTERLY LOW LEVEL FLOW REGIME UNDER
RELATIVELY DRY SOUTHWESTERLY MID LEVEL FLOW. MOISTURE REMAINS
LIMITED IN DEPTH WEDNESDAY AND WEDNESDAY NIGHT RESULTING IN LIGHT
PRECIPITATION AMOUNTS AND POPS REMAIN IN THE SLIGHT CHANCE TO CHANCE
RANGE. THERMAL PROFILES ARE GENERALLY NOT SUPPORTIVE OF FROZEN
PRECIPITATION DURING THIS PERIOD...BUT MAY BECOME MARGINAL FOR AT
LEAST A MIX OF RAIN SNOW WEDNESDAY NIGHT IN THE FAR NORTHWEST.
CONFIDENCE IN THIS IS LOW HOWEVER...ESPECIALLY CONSIDERING THE NEW
ECMWF AND THE CONTINUED NORTHWARD TREND. A PROGRESSIVE UPPER FLOW
PATTERN WILL CONTINUE INTO LATE WEEK WITH UPPER LEVEL RIDGING
QUICKLY BUILDING ACROSS THE WESTERN HALF OF THE CONUS BY FRIDAY AND
NOTEWORTHY HEIGHT RISES OVER OUR AREA. IF MEDIUM RANGE GUIDANCE
SHOWS CONSISTENCY...THIS MAY REQUIRE A CONSIDERABLE UPWARD
ADJUSTMENT IN TEMPERATURES FOR LATE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 511 AM MDT SAT OCT 26 2013
VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST PERIOD.
NORTHERLY WINDS AT 10 TO 12 KNOTS WILL OCCUR THROUGH EARLY
AFTERNOON. WEAK SURFACE HIGH PRESSURE WILL INFLUENCE THE WEATHER
AT BOTH TERMINALS DURING THE AFTERNOON RESULTING IN A DECREASE IN
WINDS LATE IN THE DAY. DURING THE EVENING THE WIND WILL BECOME
SOUTHWESTERLY AND INCREASE SLIGHTLY OVERNIGHT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BRB
AVIATION...BRB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
253 AM MDT SAT OCT 26 2013
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 253 AM MDT SAT OCT 26 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW NW FLOW OVER NORTHERN
PLAINS WITH POSITIVELY TILTED SHORTWAVE TROUGH EXTENDING SOUTH
ACROSS WESTERN KS AND OK/TX PANHANDLES. SUBSIDENCE IS BEGINNING TO
BUILD SOUTH INTO SW NE/NW KS ON POSITIVE SIDE OF PV HEIGHT ANOMALY
ASSOCIATED WITH SHORTWAVE. AT THE SURFACE A COLD FRONT IS CURRENTLY
ALONG THE NE/SD BORDER WITH A PREFRONTAL TROUGH OF LOW PRESSURE
ACROSS WESTERN. TIGHT GRADIENT IS BEGINNING TO BUILD INTO SW NE/NW
KS NORTH OF THE SURFACE TROUGH AXIS. VAD WINDS INDICATE 30-35 KT LLJ
IN PLACE OVER KGLD MATCHING RAP BL AND H85 WINDS. RADAR INDICATES
LIGHT RETURNS (LIKELY VIRGA) TRANSITIONING SOUTH AHEAD OF SURFACE
TROUGH AXIS SOUTH OF OUR CWA.
WITH SUBSIDENCE BUILDING SOUTH AND 30-35KT LLJ IN PLACE WE COULD SEE
A PERIOD OF GUSTY WINDS DEVELOP DURING THE MORNING HOURS...HOWEVER
GRADIENT SHOULD QUICKLY WEAKEN AS FRONT APPROACHES FROM THE NORTH BY
MIDDAY...SO WINDS SHOULD GENERALLY SHOW A DECREASING TREND THROUGH
THE DAY FROM THE NORTH TO THE SOUTH AFTER ABOUT 15Z. FRONT WILL
QUICKLY SWING SOUTH AND EAST...WITH THERMAL TROUGH BEGINNING TO
REDEVELOP THIS AFTERNOON IN THE WEST. RESULT WILL LIKELY BE TEMPS
NEAR OR SLIGHTLY COOLER THAN YESTERDAY IN THE UPPER 50S/LOW 60S.
FORECAST SHOULD REMAIN DRY AND MILD SUNDAY WITH SHORTWAVE RIDGE IN
PLACE...WITH HIGHS WARMING INTO 70S ACROSS CWA.
SUNDAY NIGHT-MONDAY NIGHT...PATTERN CHANGE IS STILL EXPECTED AS
UPPER LOW DROPS OUT OF PAC NW AND DEEPENS OVER THE SW CONUS...AND
COLD FRONT DROPS SOUTH INTO THE PLAINS STALLING SOUTH OF OUR CWA.
MODELS HAVE COME INTO REASONABLE AGREEMENT ON THE TIMING/EVOLUTION
OF THIS SYSTEM THROUGH MONDAY NIGHT...ALONG WITH COLD FRONT
PASSAGE SUNDAY NIGHT INTO MONDAY MORNING. THERE ARE SOME
DIFFERENCES REGARDING LOW LEVEL MOISTURE RETURN BEHIND THIS FRONT
ALONG WITH TIMING OF STRONGEST CAA...HOWEVER PICTURE REMAINS VERY
SIMILAR. CONSIDERING SHALLOW MOISTURE PROFILE ADVERTISED BY ALL
MODELS...THIS SHOULD BE A DRIZZLE/LIGHT PRECIP EVENT STARTING
MONDAY AFTERNOON THROUGH MONDAY NIGHT. BASED ON TEMP PROFILES BY
NAM/GFS/ECMWF I WOULD EXPECT PRECIP TO REMAIN LIQUID...WITH
FREEZING DRIZZLE POSSIBLE IN THE FAR NW PART OF THE CWA LATE MON
NIGHT AS SURFACE TEMPS HOVER AROUND 32F. WHILE A LIGHT GLAZE
COULDNT BE RULED OUT ON ELEVATED SURFACES FOR A FEW HOURS IN PARTS
OF YUMA COUNTY LATE MON NIGHT...THIS PROBABLY WONT NECESSITATE AN
ADVISORY CONSIDERING WARM GROUND/ROAD TEMPS AND BRIEF/LIGHT NATURE
OF THE FREEZING PRECIP.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 253 AM MDT SAT OCT 26 2013
AT THE START OF THE EXTENDED PERIOD...A SIGNIFICANT UPPER TROUGH
WILL BE POSITIONED ACROSS THE WESTERN CONUS. MODELS HAVE COME INTO
BETTER AGREEMENT IN RECENT RUNS AND CONTINUE TO SHIFT THE TRACK
NORTHWARD. THIS HAS NECESSITATED AN ADJUSTMENT IN PRECIPITATION TYPE
TO ALMOST ALL LIQUID PHASE. USING GFS FORECAST SOUNDINGS...WHICH
SHOULD GENERALLY REPRESENT A CONSENSUS OF MEDIUM RANGE MODELS
DESPITE SOME RELATIVELY MINOR DIFFERENCES IN POSITION AND CHARACTER
OF THE TROUGH...SHALLOW LOW LEVEL MOISTURE WOULD BE MOST SUPPORTIVE
OF A STRATUS...FOG AND/OR DRIZZLE SCENARIO EARLY TUESDAY. THIS WILL
OCCUR IN A MOIST EASTERLY/NORTHEASTERLY LOW LEVEL FLOW REGIME UNDER
RELATIVELY DRY SOUTHWESTERLY MID LEVEL FLOW. MOISTURE REMAINS
LIMITED IN DEPTH WEDNESDAY AND WEDNESDAY NIGHT RESULTING IN LIGHT
PRECIPITATION AMOUNTS AND POPS REMAIN IN THE SLIGHT CHANCE TO CHANCE
RANGE. THERMAL PROFILES ARE GENERALLY NOT SUPPORTIVE OF FROZEN
PRECIPITATION DURING THIS PERIOD...BUT MAY BECOME MARGINAL FOR AT
LEAST A MIX OF RAIN SNOW WEDNESDAY NIGHT IN THE FAR NORTHWEST.
CONFIDENCE IN THIS IS LOW HOWEVER...ESPECIALLY CONSIDERING THE NEW
ECMWF AND THE CONTINUED NORTHWARD TREND. A PROGRESSIVE UPPER FLOW
PATTERN WILL CONTINUE INTO LATE WEEK WITH UPPER LEVEL RIDGING
QUICKLY BUILDING ACROSS THE WESTERN HALF OF THE CONUS BY FRIDAY AND
NOTEWORTHY HEIGHT RISES OVER OUR AREA. IF MEDIUM RANGE GUIDANCE
SHOWS CONSISTENCY...THIS MAY REQUIRE A CONSIDERABLE UPWARD
ADJUSTMENT IN TEMPERATURES FOR LATE WEEK.
&&
.AVIATION...(FOR TAFS VALID 06Z SAT - 06Z SUN)
ISSUED AT 1050 PM MDT FRI OCT 25 2013
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. UPPER TROUGH
CURRENTLY PASSING SOUTH OF THE AREA WILL RESULT ONLY IN CIRRUS
CLOUDS OVERNIGHT...AND CLEAR SKIES SATURDAY AS IT PULLS AWAY FROM
THE REGION. AT THE SURFACE...WINDS ARE CURRENTLY BECOMING NORTHWEST
AS A SURFACE TROUGH...ORIENTED NE-SW...PASSES THROUGH THE FORECAST
AREA. NORTHWEST WINDS WILL INCREASE TO 10-15 KTS BEHIND THE TROUGH
AT BOTH TERMINALS OVERNIGHT. A SURFACE HIGH WILL AFFECT THE AREA
SATURDAY. AS THE HIGH MOVES EAST SATURDAY EVENING...LIGHT SOUTHERLY
WINDS WILL DEVELOP IN THE RETURN FLOW ON THE BACK OF THE HIGH.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BRB
AVIATION...ALW/DLF
AREA FORECAST DISCUSSION
NWS GRAY ME
127 PM EDT SAT OCT 26 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST TODAY AND WILL CROSS THE
REGION TONIGHT. A RIDGE OF HIGH PRESSURE WILL NOSE IN FROM THE
SOUTHWEST ON SUNDAY. ANOTHER COLD FRONT WILL SWEEP SOUTHEAST
THROUGH THE REGION MONDAY. HIGH PRESSURE WILL BUILD IN FROM THE
WEST MONDAY NIGHT THROUGH TUESDAY AND WILL SHIFT EAST OF THE
REGION ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
LATEST HRRR RUN CONTINUES TO SHOW ANY LIGHT PRECIPITION BEING
MAINLY CONFINED TO THE MOUNTAINS AND FOOTHILLS TODAY. LATEST 12Z
GYX SOUNDING INDICATES THAT SOME DRY AIR IS PLACE...SO NOT ALL OFTHE
ECHOES ON RADAR IMAGERY WILL BE MAKING IT TO THE GROUND.
TEMPERATURE PROFILES SUGGEST THAT THE HIGHER TERRAIN WILL CONTINUE
TO BE MIXING WITH SNOW THIS AFTERNOON. LIGHT ACCUMULATIONS ARE POSSIBLE IN
THIS REGION.
MADE A FEW MINOR TWEAKS TO THE CLOUD AND DEW POINT FORECASTS FOR
THIS AFTERNOON. OTHERWISE...LITTLE IN THE WAY OF CHANGES TO THE
GRIDDED DATABASE.
PREV DISC...
WEAK OVER-RUNNING AHEAD OF LOW PRESSURE CROSSING SOUTHERN
CANADA WILL SHIFT INTO THE REGION TODAY. HIGH CLOUDS MOVING IN
FROM THE WEST WILL OVER-SPREAD MUCH OF THE FORECAST AREA BY
DAYBREAK AND CLOUDS WILL GRADUALLY LOWER THROUGH THIS EVENING.
WILL SEE A SLIGHT CHANCE OF A SNOW SHOWER IN NORTHERN ZONES THIS
MORNING AS PLUME OF LAKE EFFECT OFF ONTARIO LIFTS NORTHWARD IN
BACKING LOW LEVEL FLOW.
BOUNDARY LAYER WILL QUICKLY WARM THIS MORNING AND BY THE TIME
LIGHT PRECIP ASSOCIATED WITH WARM ADVECTION ENTERS NORTHERN ZONES
EARLY THIS AFTERNOON SHOULD SEE MAINLY RAIN SHOWERS ALTHOUGH
ELEVATIONS ABOVE 2KFT WILL LIKELY PICK UP SOME WET SNOW. EXPECT
SHOWER ACTIVITY TO WORK IT`S WAY SOUTHEAST THROUGH THE EVENING
HOURS BUT SHOULD BE LIGHT AND SPOTTY. LOOKING FOR HIGH TEMPS FROM
THE LOWER TO MID 40S NORTH AND UPPER 40S TO LOWER 50S SOUTH.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
BEST CHANCE OF SHOWERS WILL COME WITH THE FROPA OVERNIGHT BUT
AGAIN EXPECT ANY PRECIP TO BE LIGHT AND SPOTTY AS MOST MODELS ONLY
SHOWING TOTALS OF A TENTH OF AN INCH OR LESS. EXPECT TEMPERATURES
TO REMAIN ABOVE FREEZING WITH MUCH OF THE AREA IN THE MID 30S TO
NEAR 40.
WILL SEE CLEARING DOWNWIND OF THE MOUNTAINS ON SUNDAY AS NORTHWEST
FLOW KICKS IN BEHIND THE FRONT. SKIES WILL REMAIN MOSTLY CLOUDY IN
THE MOUNTAINS WITH JUST A SLIGHT CHANCE OF A FLURRY OR SPRINKLE.
SHOULD SEE HIGHS IN THE LOWER TO MID 40S NORTH AND UPPER 40S TO
MID 50S SOUTH EARLY BEFORE COLDER AIR STARTS FILTERING INTO THE
REGION BY MID AFTERNOON.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
COLD NW FLOW SUNDAY NIGHT WITH ISOLD/SCT -SHSN POSSIBLY DEVELOPING
LATE N/MT ZONES DUE TO UPSLOPE FLOW. A COLD FRONT MOVES THRU ON
MONDAY WITH -SHRASN PSBL N/MT AREAS AND MAYBE INTO THE FOOTHILLS
WHILE ELSEWHERE REMAINS DRY. SW FLOW AHEAD OF THE FNT WILL BRING A
LITTLE MILDER AIR IN...ONLY TO SEE COLDER AIR FOLLOW THE PASSAGE OF
THE COLD FRONT.
COLD NW FLOW AGAIN MONDAY NIGHT WITH ISOLD/SCT -SHSN ACROSS THE N/MT
ZONES DUE TO UPSLOPE FLOW. HIGH PRESSURE BRINGS FAIR BUT COLD WX
TUESDAY AND TUESDAY NIGHT. DRY WX GIVES WAY TO INCREASING CHANCE OF
PRCP WEDNESDAY AND WEDNESDAY NGT AS THE UPPER LEVEL RIDGE AND THE
SFC HIGH MOVES TO OUR EAST ALLOWING A LARGE UPPER LEVEL TROF AND
STRONG SFC LOW OVER THE NATION`S MID SECTION TO SPREAD ITS INFLUENCE
EASTWARD TO THE E COAST. SHOULD SEE SOME MODERATION IN TEMPS ON
WEDNESDAY.
BEST CHC FOR RAIN FROM THIS SYSTEM WILL BE THURSDAY AND THURSDAY
NIGHT WHEN VERY STRONG S SW FLOW LIKELY TO DEVELOP AS WELL WITH
SURGE OF WARM MOIST AIR PUSHING UP THE E COAST AHEAD OF THE VIGOROUS
SYSTEM TO OUR WEST. A COLD FRONT MOVES THRU FOR FRIDAY BUT STILL MAY
SEE SOME SHRA LINGER ACROSS PORTIONS OF THE FCST AREA.
USED A BLEND OF MODELS AND MOS GUIDANCE AND HPC QPF FOR PERIODS 4
AND 5...THEN USED A SUPER BLEND OF VARIOUS MODELS AND MOS GUIDANCE
BIAS CORRECTED GUIDANCE AND THE PREVIOUS FORECAST FOR DAYS 4 THRU
8.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
SHORT TERM...VFR TODAY THROUGH SUNDAY WITH SOME MVFR CEILINGS IN
THE MOUNTAINS TONIGHT AND SUNDAY.
LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...MAINLY VFR EXCEPT
MVFR CIG/VSBY PSBL WITH SHRASN OVER THE N/MT AREAS MONDAY AND
MONDAY NGT DUE TO CFP ON MONDAY AND NW UPSLOPE FLOW BEHIND THE
COLD FRONT MONDAY NIGHT.
&&
.MARINE...
SHORT TERM...GALE WARNING FOR MID AND EASTERN OUTER WATERS LATE
THIS AFTERNOON THROUGH 2AM TONIGHT. SCA`S ELSEWHERE THROUGH SUNDAY
MORNING.
LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...NW FLOW BEHIND
DEPARTING COLD FRONT MAY SEE WIND GUSTS AND SEAS INTO MINIMAL SCA
LEVELS OVER THE OUTER WATERS SUNDAY NIGHT. SW FLOW INCREASES AHEAD
OF ANOTHER COLD FRONT ON MONDAY WHEN WIND GUSTS AND SEAS MAY AGAIN
REACH MINIMAL SCA LEVELS OVER THE OUTER WATERS. OTHERWISE EXPECT
WINDS AND SEAS TO BE BELOW SCA CRITERIA THRU THE LONG TERM FCST
PERIOD.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT SUNDAY FOR ANZ151-153-154.
GALE WARNING FROM 5 PM THIS AFTERNOON TO 2 AM EDT SUNDAY FOR
ANZ150-152.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
911 AM EDT SAT OCT 26 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST TODAY AND WILL CROSS THE
REGION TONIGHT. A RIDGE OF HIGH PRESSURE WILL NOSE IN FROM THE
SOUTHWEST ON SUNDAY. ANOTHER COLD FRONT WILL SWEEP SOUTHEAST
THROUGH THE REGION MONDAY. HIGH PRESSURE WILL BUILD IN FROM THE
WEST MONDAY NIGHT THROUGH TUESDAY AND WILL SHIFT EAST OF THE
REGION ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
WEAK OVER-RUNNING AHEAD OF LOW PRESSURE CROSSING SOUTHERN CANADA
WILL SHIFT INTO THE REGION TODAY. HIGH CLOUDS MOVING IN FROM THE
WEST WILL OVER-SPREAD MUCH OF THE FORECAST AREA BY DAYBREAK AND
CLOUDS WILL GRADUALLY LOWER THROUGH THIS EVENING. WILL SEE A
SLIGHT CHANCE OF A SNOW SHOWER IN NORTHERN ZONES THIS MORNING AS
PLUME OF LAKE EFFECT OFF ONTARIO LIFTS NORTHWARD IN BACKING LOW
LEVEL FLOW.
BOUNDARY LAYER WILL QUICKLY WARM THIS MORNING AND BY THE TIME
LIGHT PRECIP ASSOCIATED WITH WARM ADVECTION ENTERS NORTHERN ZONES
EARLY THIS AFTERNOON SHOULD SEE MAINLY RAIN SHOWERS ALTHOUGH
ELEVATIONS ABOVE 2KFT WILL LIKELY PICK UP SOME WET SNOW. EXPECT
SHOWER ACTIVITY TO WORK IT`S WAY SOUTHEAST THROUGH THE EVENING
HOURS BUT SHOULD BE LIGHT AND SPOTTY. LOOKING FOR HIGH TEMPS FROM
THE LOWER TO MID 40S NORTH AND UPPER 40S TO LOWER 50S SOUTH.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
UPDATE...
LATEST HRRR RUN CONTINUES TO SHOW ANY LIGHT PRECIPITION BEING
MAINLY CONFINED TO THE MOUNTAINS AND FOOTHILLS TODAY. LATEST 12Z
GYX SOUNDING INDICATES THAT SOME DRY AIR IS PLACE...SO NOT OFF OF
THE ECHOES ON RADAR IMAGERY WILL BE MAKING IT TO THE GROUND.
TEMPERATURE PROFILES SUGGEST THAT THE HIGHER TERRAIN WILL BE
MIXING WITH SNOW TODAY. LIGHT ACCUMULATIONS ARE POSSIBLE IN THIS
REGION.
MADE A FEW MINOR TWEAKS TO THE CLOUD AND DEW POINT FORECASTS FOR
THIS AFTERNOON. OTHERWISE...LITTLE IN THE WAY OF CHANGES TO THE
GRIDDED DATABASE.
PREV DISC...
BEST CHANCE OF SHOWERS WILL COME WITH THE FROPA OVERNIGHT BUT
AGAIN EXPECT ANY PRECIP TO BE LIGHT AND SPOTTY AS MOST MODELS ONLY
SHOWING TOTALS OF A TENTH OF AN INCH OR LESS. EXPECT TEMPERATURES
TO REMAIN ABOVE FREEZING WITH MUCH OF THE AREA IN THE MID 30S TO
NEAR 40.
WILL SEE CLEARING DOWNWIND OF THE MOUNTAINS ON SUNDAY AS NORTHWEST
FLOW KICKS IN BEHIND THE FRONT. SKIES WILL REMAIN MOSTLY CLOUDY IN
THE MOUNTAINS WITH JUST A SLIGHT CHANCE OF A FLURRY OR SPRINKLE.
SHOULD SEE HIGHS IN THE LOWER TO MID 40S NORTH AND UPPER 40S TO
MID 50S SOUTH EARLY BEFORE COLDER AIR STARTS FILTERING INTO THE
REGION BY MID AFTERNOON.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
COLD NW FLOW SUNDAY NIGHT WITH ISOLD/SCT -SHSN POSSIBLY DEVELOPING
LATE N/MT ZONES DUE TO UPSLOPE FLOW. A COLD FRONT MOVES THRU ON
MONDAY WITH -SHRASN PSBL N/MT AREAS AND MAYBE INTO THE FOOTHILLS
WHILE ELSEWHERE REMAINS DRY. SW FLOW AHEAD OF THE FNT WILL BRING A
LITTLE MILDER AIR IN...ONLY TO SEE COLDER AIR FOLLOW THE PASSAGE OF
THE COLD FRONT.
COLD NW FLOW AGAIN MONDAY NIGHT WITH ISOLD/SCT -SHSN ACROSS THE N/MT
ZONES DUE TO UPSLOPE FLOW. HIGH PRESSURE BRINGS FAIR BUT COLD WX
TUESDAY AND TUESDAY NIGHT. DRY WX GIVES WAY TO INCREASING CHANCE OF
PRCP WEDNESDAY AND WEDNESDAY NGT AS THE UPPER LEVEL RIDGE AND THE
SFC HIGH MOVES TO OUR EAST ALLOWING A LARGE UPPER LEVEL TROF AND
STRONG SFC LOW OVER THE NATION`S MID SECTION TO SPREAD ITS INFLUENCE
EASTWARD TO THE E COAST. SHOULD SEE SOME MODERATION IN TEMPS ON
WEDNESDAY.
BEST CHC FOR RAIN FROM THIS SYSTEM WILL BE THURSDAY AND THURSDAY
NIGHT WHEN VERY STRONG S SW FLOW LIKELY TO DEVELOP AS WELL WITH
SURGE OF WARM MOIST AIR PUSHING UP THE E COAST AHEAD OF THE VIGOROUS
SYSTEM TO OUR WEST. A COLD FRONT MOVES THRU FOR FRIDAY BUT STILL MAY
SEE SOME SHRA LINGER ACROSS PORTIONS OF THE FCST AREA.
USED A BLEND OF MODELS AND MOS GUIDANCE AND HPC QPF FOR PERIODS 4
AND 5...THEN USED A SUPER BLEND OF VARIOUS MODELS AND MOS GUIDANCE
BIAS CORRECTED GUIDANCE AND THE PREVIOUS FORECAST FOR DAYS 4 THRU
8.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...VFR TODAY THROUGH SUNDAY WITH SOME MVFR CEILINGS IN
THE MOUNTAINS TONIGHT AND SUNDAY.
LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...MAINLY VFR EXCEPT
MVFR CIG/VSBY PSBL WITH SHRASN OVER THE N/MT AREAS MONDAY AND
MONDAY NGT DUE TO CFP ON MONDAY AND NW UPSLOPE FLOW BEHIND THE
COLD FRONT MONDAY NIGHT.
&&
.MARINE...
SHORT TERM...GALE WARNING FOR MID AND EASTERN OUTER WATERS LATE
THIS AFTERNOON THROUGH 2AM TONIGHT. SCA`S ELSEWHERE THROUGH SUNDAY
MORNING.
LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...NW FLOW BEHIND
DEPARTING COLD FRONT MAY SEE WIND GUSTS AND SEAS INTO MINIMAL SCA
LEVELS OVER THE OUTER WATERS SUNDAY NIGHT. SW FLOW INCREASES AHEAD
OF ANOTHER COLD FRONT ON MONDAY WHEN WIND GUSTS AND SEAS MAY AGAIN
REACH MINIMAL SCA LEVELS OVER THE OUTER WATERS. OTHERWISE EXPECT
WINDS AND SEAS TO BE BELOW SCA CRITERIA THRU THE LONG TERM FCST
PERIOD.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT SUNDAY FOR ANZ151-153-154.
GALE WARNING FROM 5 PM THIS AFTERNOON TO 2 AM EDT SUNDAY FOR
ANZ150-152.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
740 PM EDT SUN OCT 27 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 407 PM EDT SUN OCT 27 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A SHORTWAVE SWINGING SE
THRU NRN ONTARIO. WAA PATTERN AHEAD OF WAVE HAS PRODUCED SOME PCPN
ACROSS LAKE SUPERIOR. ALTHOUGH RADAR RETURNS ALSO BLOSSOMED ACROSS
MUCH OF UPPER MI...DRY AIR AT THE LOW-LEVELS HAS KEPT MOST OF THE
PCPN FROM REACHING THE GROUND. AT THE SFC...ASSOCIATED COLD FRONT IS
JUST NOW ENTERING NW LAKE SUPERIOR. REGIONAL RADAR IMAGERY AND SFC
OBS INDICATE SOME PCPN OCCURRING IN THE VCNTY OF AND BEHIND THE
FRONT.
AS SHORTWAVE CONTINUES TO SWING ACROSS NRN ONTARIO...ASSOCIATED COLD
FRONT WILL QUICKLY SWEEP SE ACROSS THE FCST AREA THIS EVENING.
HEALTHY PRES RISES OF 6-7MB/3HR WITH FAVORABLE ALIGNMENT OF THE
ISALLOBARIC WIND WITH GRADIENT WIND WILL LEAD TO GUSTY NRLY WINDS
BEHIND FRONT...ESPECIALLY CLOSE TO THE LAKE SUPERIOR SHORELINE AS
OVERWATER INSTABILITY STRENGTHENS (850MB TEMPS DROP FROM ROUGHLY
-4/-5C AT 00Z TO -9/-11C BY 06Z). WINDS WILL LIKELY GUSTS TO AROUND
40MPH AT EXPOSED LOCATIONS. OTHERWISE...EXPECT A PERIOD OF LAKE
ENHANCED PCPN ALONG COLD FRONT AS LOW-LEVEL CONVERGENCE AND DEEP
LAYER FORCING FROM SHORTWAVE ACT ON OVERWATER INSTABILITY
(LAKE-850MB DELTA-T AROUND 13C). AFTER A PERIOD OF SHRASN IN VCNTY
OF COLD FRONT...THERE WILL BE A TRANSITION TO N TO NE FLOW LES AS
LAKE-850MB DELTA-T INCREASES TO 17C OR BETTER. HOWEVER...THERE WILL
BE STRONG NEGATIVES WORKING AGAINST MUCH MORE THAN LIGHT LES.
FIRST...LOW-LEVEL WIND FLOW BECOMES SHARPLY ANTICYCLONIC AS SFC HIGH
PRES RIDGE QUICKLY NOSES SE INTO THE UPPER LAKES...AND SECOND...
INVERSION CRASHES TO 4KFT WITH DENDRITIC SNOW GROWTH TEMP ZONE
REMAINING ABOVE THE SHALLOW MOIST LAYER. LIKELY POPS STILL LOOK ON
TRACK FOR THE N TO NE FLOW FAVORED LOCATIONS...BUT SNOW
ACCUMULATIONS SHOULD BE MINIMAL (PERHAPS AN INCH OR TWO...INCLUDING
EVENING PCPN ALONG FRONT...WHERE STRONGEST UPSLOPING OCCURS SUCH AS
THE HURON MTNS). LATE IN THE NIGHT/EARLY MON MORNING...THERE ARE
SOME HINTS THAT MOISTENING FROM LAKE NIPIGON MAY SUPPORT A BAND OF
MORE PERSISTENT LES INTO FAR WRN UPPER MI AROUND KIWD/PORCUPINE
MTNS.
STRONG SFC HIGH PRES RIDGE WILL BUILD SE ACROSS THE UPPER LAKES
DURING MON. ALTHOUGH INVERSION BASE TEMP AROUND -10C PROVIDES A
LAKE-850MB DELTA-T AROUND 17C OR SO...LES WILL STRUGGLE MON DUE TO
SHARP ANTICYCLONIC FLOW AND A LOW INVERSION AT 3-4KFT. COMBINED WITH
EARLY SEASON NEGATIVE EFFECTS OF DAYTIME HEATING DISRUPTING LAKE
EFFECT PROCESSES...WILL STICK WITH THE IDEA OF LES ENDING EARLY IN
THE AFTN. ONLY POSSIBLE EXCEPTION MAY BE FOR SOME FLURRIES TO LINGER
ALONG THE TRAJECTORY DOWN WIND FROM LAKE NIPIGON. ALTHOUGH FLOW WILL
BE ANTICYCLONIC...MOISTURE PICKED UP OFF LAKE SUPERIOR WILL PROBABLY
LEAD TO QUITE A BIT OF STRATOCU THRU THE DAY ACROSS MUCH OF THE FCST
AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 332 PM EDT SUN OCT 27 2013
AT 00Z TUE...A 1035MB SFC HIGH WILL BE CENTERED OVER SRN MANITOBA
AND WILL WEAKEN SLIGHTLY WHILE BECOMING CENTERED OVER THE CWA BY TUE
MORNING. 850MB TEMPS WILL BE AROUND -8C AND WITH MOSTLY CLEAR SKIES
(AT LEAST INLAND)...MON NIGHT LOWS WILL FALL INTO THE TEENS INLAND
AND INTO THE 20S CLOSER TO LAKE SUPERIOR. THE SFC HIGH WILL MOVE TO
THE NE CONUS BY 00Z WED AS AN UPPER LOW SITS OVER THE INTERMOUNTAIN
WEST...WITH THE ASSOCIATED SFC LOW DEVELOPING LEEWARD OF THE CO
ROCKIES. THE SLY LOW LEVEL FLOW BETWEEN THESE SYSTEMS WILL BRING A
WARM FRONT TO JUST S OF THE CWA BY TUE AFTERNOON WHILE A WEAK
SHORTWAVE AND LEFT EXIT REGION OF AN UPPER JET MOVE NEAR OR OVER THE
CWA. THESE FORCING MECHANISMS MAY BRING SOME PRECIP TO PORTIONS OF
THE CWA TUE AFTERNOON/EVENING...WITH THE BEST CHANCES OF PRECIP OVER
THE SRN CWA. STILL UNCERTAIN ON IF/WHERE PRECIP WILL FALL...BUT ANY
PRECIP OVER THE CWA SHOULD FALL AS MOSTLY SNOW GIVEN ONLY A SHALLOW
WARM LAYER NEAR THE SFC. HIGHS ON TUE LOOK TO BE IN THE 30S TO
AROUND 40.
THEN THROUGH FRIDAY...THE FORECAST IS VERY DEPENDENT ON THE
TRACK/STRENGTH OF THE SYSTEM OVER THE WRN CONUS EARLIER IN THE WEEK.
WHILE MODELS AGREE ON GENERAL SETUP...THEY VARY SIGNIFICANTLY WITH
MORE SPECIFIC AND IMPORTANT DETAILS WITH THIS TYPE OF SYSTEM. THE
OVERALL IDEA IS THAT THE UPPER LOW WILL EJECT OUT INTO THE PLAINS
WHILE THE ASSOCIATED UPPER TROUGH BECOMES MORE NEGATIVELY TILTED AS
IT MOVES TOWARD THE CWA...THIS LEADS TO A DEEPENING OF THE SFC LOW
AS IT MOVES INTO THE GREAT LAKE REGION. MODEL VARIABILITY (BOTH
BETWEEN MODELS AND WITH INTER MODEL RUN TO RUN CONTINUITY) MAY SEEM
SMALL WITH RELATION TO THE TRACK/INTENSITY OF THE SYSTEM...BUT WITH
A FAIRLY COMPACT LOW IT WILL MAKE HUGE DIFFERENCES IN WIND/WAVE
FORECASTS AND WITH PRECIP AMOUNTS/TIMING. CONFIDENCE IN THESE
ASPECTS OF THE FORECAST ARE VERY LOW FOR THIS PERIOD...ESPECIALLY
SINCE MODELS WILL LIKELY CHANGE SIGNIFICANTLY WITH FUTURE RUNS AS IS
COMMON WITH THIS TYPE OF SYSTEM. WHAT IS MORE CERTAIN IS THAT MOST
(IF NOT ALL) PRECIP WILL BE RAIN GIVEN 850MB TEMPS INCREASING TO UP
TO 10C AHEAD OF THE SYSTEM...OR A BIT COLDER IF THE SYSTEM STAY S OF
THE CWA BUT STILL WARM ENOUGH FOR ALMOST ALL OF THE PRECIP TO BE
RAIN...AND AIR COLD ENOUGH FOR SNOW BEHIND THE SYSTEM DOES NOT
ARRIVE UNTIL THE SYSTEM IS WELL DOWNSTREAM OF THE CWA.
FRI NIGHT AND SAT WILL SEE INCREASING CHANCES OF PRECIP...WITH
INCREASING CHANCES OF THAT PRECIP BEING ALL SNOW WITH TIME. 850MB
TEMPS BEHIND THE SYSTEM WILL DECEASE FROM -2C AT 00Z SAT TO AROUND
-7C BY 00Z SUN. LOW LEVEL NW WINDS WILL BE SLIGHTLY CYCLONIC TO
NEUTRAL IN DIRECTIONAL CHANGE ACROSS LAKE SUPERIOR. CONDITIONS ARE
MORE UNCERTAIN FOR SUN AS MODELS DIFFER MUCH MORE SIGNIFICANTLY BE
LATER IN THE DAY...BUT LES SHOULD BE ABLE TO CONTINUE AT LEAST
THROUGH SAT NIGHT AND INTO SUN MORNING. GIVEN UNCERTAINTY OVERALL IN
EXTENDED FORECAST...JUST USED A CONSENSUS OF MODELS...ESPECIALLY FOR
WED THROUGH NEXT SUN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 740 PM EDT SUN OCT 27 2013
FRONT HAS CLEARED WESTERN TWO TAF SITES (KIWD/KCMX). MVFR CONDITIONS
HAVE DEVELOPED BEHIND THE FRONT. THESE CONDITIONS WILL ARRIVE AT SAW
SHORTLY WITH MOIST UPSLOPE NORTHERLY FLOW OFF LAKE SUPERIOR. WITH
STRONG PRES RISES BEHIND FRONT...WINDS WILL BE QUITE GUSTY INTO THE
25-35KT RANGE FOR A TIME THROUGH LATE THIS EVENING. THE
HEAVIEST/MOST PERSISTENT LAKE EFFECT -SHSN ARE MORE LIKELY AT
KSAW...WHERE UPSLOPE WIND COMPONENT WILL BE SHARPEST. THE VIS AT
KSAW IS LIKELY TO FALL TO IFR AT TIMES UNDER SOME OF THE HEAVIER
SHSN. FAVORABLE CONVERGENCE MAY RESULT IN A BAND OF HEAVIER SHSN AND
POSSIBLE IFR CONDITIONS AFFECTING KIWD EARLY MON MORNING.
OTHERWISE...WINDS WILL DIMINISH OVERNIGHT INTO MON MORNING AS THE
PRES GRADIENT SLACKENS WITH HIGH PRES RIDGE AXIS MOVING CLOSER. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 407 PM EDT SUN OCT 27 2013
COLD FRONT WILL QUICKLY DROP SE ACROSS LAKE SUPERIOR OVER THE NEXT
SEVERAL HRS. WITH STRONG HIGH PRES RIDGING SE TOWARD LAKE
SUPERIOR BEHIND FRONT...HEALTHY PRES RISES OF 6-7MB/3HR WILL FOLLOW
THE FRONT. COMBINED WITH AN INFLUX OF COLDER AIR RESULTING IN STRONG
OVERWATER INSTABILITY...EXPECT A PERIOD OF NORTHERLY 35-40KT GALES
THIS EVENING OVER MUCH OF LAKE SUPERIOR. GALES WILL BE
SHORT-LIVED...ENDING AFTER MIDNIGHT AS PRES RISE MAX QUICKLY SHIFTS
S OF LAKE SUPERIOR. LIGHTER WINDS...MOSTLY UNDER 20KT...SHOULD THEN
PREVAIL LATER MON THRU EARLY WED AS THE HIGH PRES RIDGE SETTLES OVER
THE AREA. LATE WED THRU FRI THERE IS THE POTENTIAL FOR STRONGER
WINDS OF AT LEAST 15-25KT...AND POSSIBLY TO GALE FORCE...AS A LOW
PRESSURE SYSTEM LIFTS FROM THE PLAINS ACROSS THE GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 11 PM THIS EVENING TO 5 AM EDT MONDAY FOR
LSZ267.
GALE WARNING FROM 10 PM THIS EVENING TO 5 AM EDT MONDAY FOR
LSZ265-266.
GALE WARNING FROM 8 PM EDT /7 PM CDT/ THIS EVENING TO 2 AM EDT
/1 AM CDT/ MONDAY FOR LSZ162-263-264.
GALE WARNING FROM 8 PM THIS EVENING TO 5 AM EDT MONDAY FOR
LSZ248>251.
GALE WARNING UNTIL 2 AM EDT /1 AM CDT/ MONDAY FOR LSZ240>245.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...MZ
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
431 PM EDT SAT OCT 26 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 429 PM EDT SAT OCT 26 2013
PER WATER VAPOR IMAGERY AND RUC ANALYSIS...THE VIGOROUS SHORTWAVE
THAT MOVED ACROSS THE AREA LAST NIGHT IS NOW IN SRN QUEBEC. ANOTHER
SHORTWAVE THAT FOLLOWED THE FIRST PASSED ACROSS THE UPPER LAKES
EARLY THIS AFTN AND HAS PROVIDED A BOOST TO LAKE EFFECT PCPN.
ASSOCIATED SFC LOW WITH PRIMARY SHORTWAVE IS NOW LOCATED IN SW
QUEBEC. TIGHT PRES GRADIENT BTWN THE DEPARTING LOW AND HIGH PRES
RIDGE OVER THE DAKOTAS IS RELAXING...AND NOW THAT THE SFC PRES RISE
MAX HAS SLIPPED JUST E OF LAKE SUPERIOR...WINDS ARE DIMINISHING. OBS
OVER THE LAST HR OR TWO SHOW WINDS HAVE DIMINISHED ENOUGH TO DROP
ONGOING WIND ADVYS WITH THIS FCST ISSUANCE.
SHORTWAVES THAT PASSED ACROSS THE AREA LAST NIGHT AND EARLIER TODAY
WILL BE FOLLOWED BY ANOTHER QUICKLY DIVING SE TOWARD THE UPPER GREAT
LAKES SUN AFTN. WITH QUICK MOVEMENT OF SHORTWAVES...SFC HIGH PRES
RIDGE CURRENTLY OVER THE DAKOTAS WILL REACH UPPER MI TONIGHT...
RESULTING IN STEADILY BACKING WINDS WHICH WILL SHIFT ONGOING LAKE
EFFECT PCPN UNDER 850MB TEMPS OF -7/-8C. DURING THE OVERNIGHT...WAA
WILL GET UNDERWAY OVER THE W AHEAD OF THE NEXT SHORTWAVE. ONE
NEGATIVE FOR LAKE EFFECT PCPN OVER THE W IS THE NOTABLY WELL-MIXED
BOUNDARY LAYER SHOWN ON FCST SOUNDINGS. AS A RESULT...NOT EXPECTING
MUCH IN THE WAY OF LAKE EFFECT PCPN OVER THE W TONIGHT. WHAT PCPN
THERE IS MAY END UP MOSTLY CONCENTRATED IN THE CONVERGENCE ZONE THAT
DEVELOPS DUE TO LAND BREEZE ENHANCED BACKING OF LARGER SCALE WINDS.
TO THE E...INVERSION IS UP AROUND 7KFT. HOWEVER...A SOMEWHAT WELL
MIXED BOUNDARY LAYER...DENDRITIC SNOW GROWTH ZONE MOSTLY ABOVE THE
CONVECTIVE LAYER...BACKING WINDS AND -SHRA/SN/GRAUPEL MIX AT LEAST
EARLIER IN THE EVENING WILL ALL WORK TO KEEP SNOW ACCUMULATIONS
MINIMAL. MAY SEE LOCALLY AN INCH OR TWO OF SNOW INLAND FROM LAKE
SUPERIOR.
ON SUN...SHORTWAVE WILL BE DROPPING SE TOWARD THE AREA WITH
ASSOCIATED COLD FRONT PROBABLY MOVING THRU THE NW HALF OF UPPER MI
MID TO LATE AFTN. AHEAD OF THE FRONT...WINDS BACKING TO THE WSW WILL
BRING AN END TO ANY LINGERING LK EFFECT -SHRASN OVER THE E NEAR LAKE
SUPERIOR BY AFTN. OTHERWISE...IF THERE IS ANY MORNING SUNSHINE...IT
WILL GIVE WAY TO THICKENING CLOUDS. MODEST DEEP LAYER FORCING PER
QVECTORS OVERTOP ADEQUATE OVERWATER INSTABILITY SUGGESTS PCPN WILL
DEVELOP OR BE ENHANCED IN THE CONVERGENCE ZONE ASSOCIATED WITH COLD
FRONT. AS A RESULT...EXPECT INCREASING PCPN CHANCES TO SPREAD S FROM
THE KEWEENAW IN THE MORNING TO MUCH OF THE N HALF OF UPPER MI BY 00Z
MON. WITH WETBULB ZERO HEIGHTS INCREASING TO GENERALLY ABOVE
1500FT...PTYPE WILL BECOME MOSTLY RAIN...BUT THERE MAY BE SOME SNOW
MIXED IN OVER THE HIGHER TERRAIN.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 429 PM EDT SAT OCT 26 2013
A COLD FRONT WILL BE EXITING THE ERN CWA AT 00Z MON AS A 1040MB SFC
HIGH CENTERED OVER WRN CANADA CONTINUES A QUICK TRANSIT TOWARD THE
CWA. AS THE COLDER AIR AND SFC HIGH PRESSURE MOVE IN SUN NIGHT...THE
PRESSURE GRADIENT WILL TIGHTEN UP...LEADING TO INCREASE N-NNE WINDS
POSSIBLY LEADING TO GALES OVER LAKE SUPERIOR. 850MB TEMPS WILL
DECREASE FROM AROUND -5C TO -11C BETWEEN 00Z AND 12Z MON. THIS
COMBINED WITH THE N-NNE WINDS WILL BRING LAKE EFFECT AND UPSLOPE
SNOW TO CORRESPONDING AREAS NEAR LAKE SUPERIOR SUN NIGHT INTO MON.
ALTHOUGH FLOW WILL BE SHARPLY ANTICYCLONIC...WHICH IS NOT FAVORABLE
FOR LES...THE RIGHT ENTRANCE REGION OF THE UPPER JET WILL BE OVER
THE CWA SUN NIGHT AND MON...HELPING TO OFFSET THE NEGATIVE EFFECTS
OF THE INCREASING HIGH PRESSURE OVER THE LAKE. COULD SEE 2-3 INCHES
OF SNOW OVER THE HIGHER TERRAIN OF MARQUETTE AND WRN ALGER
COUNTIES...AS WELL AS THE HIGHER TERRAIN NEAR THE PORCUPINE
MOUNTAINS IN GOGEBIC AND ONTONAGON COUNTIES. THE LES WILL TAPER OFF
ALMOST COMPLETELY BY MID AFTERNOON MON AS THE DRY AIR AND SUBSIDENCE
OF THE SFC HIGH DOMINATE.
THE SFC HIGH WILL WEAKEN TO 1033MB AS IT MOVES TO BE CENTERED OVER
THE CWA BY 12Z TUE...MOVING TO THE NE CONUS BY 00Z WED WHILE LEAVING
A 1026MB RIDGE OVER THE CWA. MODELS DO SHOW SOME QPF OVER OR S OF
THE SRN CWA TUE INTO TUE NIGHT AS A WARM FRONT MOVES INTO OR S OF
THE CWA AND WE START WARM ADVECTING. IN FACT...BY 12Z WED...850MB
TEMPS INCREASE TO NEAR 0C. THESE TEMPS SHOULD RESULT IN HIGH TEMPS
IN THE 30S TO AROUND 40 ON TUE AND IN THE 40S TO AROUND 50 ON WED AS
850MB TEMPS INCREASE TO UP TO 7C.
ALL THIS WARM AIR IS BEING DRAW UP INTO THE CWA AHEAD OF A DEEP
UPPER LOW OVER THE INTERMOUNTAIN W AND A DEVELOPING SFC LOW LEEWARD
OF THE CO ROCKIES ON TUE. THERE IS SOME MODEL DISAGREEMENT ON
STRENGTH/TIMING/TRACK OF THE SYSTEM AS IT MOVES INTO THE REGION...BUT
OVERALL MODELS AGREE DECENTLY ON THE GENERAL PATTERN. THE UPPER LOW
OPENS INTO A TROUGH AND MOVES ACROSS THE GREAT LAKES REGION EITHER
FROM LATE THU/THU NIGHT (12Z/25 GFS SOLUTION) OR ON FRI (00Z/25
ECMWF SOLUTION)...BRINGING A DEEPENING SFC LOW WITH IT AS THE TROUGH
BECOMES NEGATIVELY TILTED BEFORE IT MOVES INTO THE AREA.
AGAIN...EXACT TRACK AND STRENGTH OF THE SYSTEM WILL MAKE A BIG
DIFFERENCE IN PRECIP AMOUNTS AND ESPECIALLY WINDS...SO THOSE ARE
VERY UNCERTAIN AT THIS TIME. ONE ASPECT IS MORE CERTAIN...AND
SIGNIFICANT FOR THIS TIME OF YEAR AND TYPE OF EVENT. PRECIP TYPE
SHOULD BE ALL RAIN AS 850MB TEMPS INCREASE TO UP TO 10C AHEAD OF THE
LOW AND DO NOT FALL BELOW 0C UNTIL THE SFC LOW IS IN QUEBEC. COULD
SEE LAKE EFFECT SNOW BEHIND THE SYSTEM ON FRI NIGHT/SAT AS MODELS
BRING COLDER LOW LEVEL TEMPS INTO THE CWA ALONG WITH AN UPPER
TROUGH. HOWEVER...MODELED 850MB TEMPS DO NOT GET THAT COLD (AROUND
-6C AT THE COLDEST) SO WOULD NEED ADDITIONAL SOURCES OF ENERGY TO
SUPPORT LAKE ENHANCEMENT FOR ANY MORE SIGNIFICANT SNOWFALL TO OCCUR.
THIS MAY HAPPEN...BUT CONFIDENCE IS LOW THAT FAR OUT ON SMALLER
SCALE DETAILS THAT WOULD BE REQUIRED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 133 PM EDT SAT OCT 26 2013
WITH LAKE EFFECT CLOUDS/PCPN OFF LAKE SUPERIOR...EXPECT CONDITIONS
VARYING BTWN MVFR/VFR AT KIWD/KCMX/KSAW THRU THE AFTN HRS. THE
LOWEST CIGS THIS AFTN ARE MORE LIKELY TO OCCUR AT KSAW DUE TO CLOSER
PROXIMITY TO DEPARTING LOW PRES SYSTEM AND DUE TO LONGER OVERWATER
TRAJECTORIES. SFC HIGH PRES RIDGE WILL MOVE E TO THE UPPER GREAT
LAKES TONIGHT. THIS WILL BRING AN END TO LINGERING LAKE EFFECT PCPN.
AS WINDS BACK...PREVAILING VFR CONDITIONS WILL DEVELOP AT KIWD/KSAW
AS OVERWATER TRAJECTORY IS LOST. OPTED TO LINGER A HIGH MVFR CIG AT
KCMX THRU THE END OF THE FCST PERIOD DUE TO SOME UNCERTAINTY IN
WHETHER OR NOT LAKE EFFECT CLOUDS WILL SHIFT N OF THAT TERMINAL.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 429 PM EDT SAT OCT 26 2013
WITH SFC HIGH PRES RIDGE QUICKLY MOVING E INTO THE UPPER GREAT LAKES
TONIGHT...LINGERING GALES OVER ERN LAKE SUPERIOR WILL END EARLY THIS
EVENING. NEXT COLD FRONT WILL QUICKLY DROP SE...CROSSING LAKE
SUPERIOR SUN AFTN/EVENING. WITH STRONG HIGH PRES RIDGING SE TOWARD
LAKE SUPERIOR BEHIND FRONT...HEALTHY PRES RISES WILL FOLLOW THE
FRONT. COMBINED WITH AN INFLUX OF COLDER AIR AND INCREASED OVERWATER
INSTABILITY...THERE SHOULD BE A PERIOD OF NORTHERLY 35KT GALES SUN
EVENING OVER MUCH OF LAKE SUPERIOR. THESE GALES WILL BE
SHORT-LIVED...ENDING AFTER MIDNIGHT SUN NIGHT. LIGHTER WINDS...
MOSTLY UNDER 20KT...SHOULD THEN PREVAIL MON-WED AS THE HIGH PRES
RIDGE SETTLES OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 PM EDT THIS EVENING FOR LSZ248>251-265>267.
GALE WARNING UNTIL 6 PM EDT THIS EVENING FOR LSZ244-245.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1217 PM CDT SAT OCT 26 2013
.AVIATION...
18Z TAFS FOR KOFK...KOMA AND KLNK.
VFR CONDITIONS ARE EXPECTED THROUGHOUT THE TAF CYCLE. GUSTY
NORTHWEST SURFACE WINDS THIS AFTERNOON WILL SUBSIDE TO LIGHT AND
VARIABLE OVERNIGHT AS HIGH PRESSURE BUILDS OVERHEAD.
KERN
&&
.PREV DISCUSSION... /ISSUED 303 AM CDT SAT OCT 26 2013/
DISCUSSION...
LITTLE CHANGE IN FORECAST CHALLENGE/CONCERN ITEMS. THE SHORT TERM
FOCUS REMAINS ON TEMPERATURES WHILE MEDIUM/LONGER TERM EMPHASIS
SHIFTS TOWARD PRECIPITATION...WHEN TO INCLUDE HIGHEST
PROBABILITIES AND WHETHER OR NOT SOMETHING OTHER THAN LIQUID
WILL FALL.
WIND SHIFT CURRENTLY WORKING THRU INTO EAST CENTRAL ZONES WILL
PROVIDE BRISK NNW WINDS AND COOLER TEMPERATURES TODAY.
HOWEVER...WITH FAVORABLE MIXING...I.E. NEARLY FULL SUNSHINE AND NW
WINDS...PLUS A THE START IN THE UPPER 30S OR WARMER...COULD ALLOW
A BIT OF A SUPER OFF SURFACE AT MAX HTG SO WOULD SUSPECT HIGHS
SHOULD AT LEAST REACH WARMER MET GUIDANCE BASED ON RAP AND OTHER
FORECAST SOUNDINGS. GENERALLY IN LINE WITH PREV FORECAST. A LATE
EVENING LOW STILL PROBABLY IN STORE FOR REGION TONIGHT AS TEMPS
STEADY LATE AS WINDS TURN SOUTHERLY. THEN SW WINDS AND EVEN WARMER
H85 TEMPS ON SUNDAY...COMPARED TO FRIDAY...WITH DRY AND SUNNY
CONDITIONS PREVAILING. THIS SHOULD ALLOW MAX TEMPS TO REACH A
CATEGORY OR MORE WARMER THAN FRIDAY...AND BOOSTED TOWARD WARMER
MET READINGS. WEAK WIND SHIFT ENTERING NRN ZONES BY LATE AFTN
SHOULD HAVE LITTLE IMPACT ON HIGHS BUT COOLER AIR PUSHING IN
BEHIND IT LATER IN THE EVENING/OVERNIGHT WILL. THIS LEADS US TO...
FORECAST UNCERTAINTIES THAT THEN BEGIN INCREASING NEXT WEEK. MAIN
ISSUE MONDAY WILL BE HOW QUICKLY CLOUDS INCREASE BECAUSE COOLER
AIR BELOW H85 WILL SET UP A FAIRLY STEEP INVERSION ABOVE 925-900
MB. NERLY SFC WINDS WILL LIMIT MIXING...ESPECIALLY IF CLOUDS
THICKEN UP BY MIDDAY OR SOONER...WHICH THEY COULD ACROSS SRN AND
WRN ZONES. BUT WITH TEMPS OFF SURFACE YET FAIRLY MILD WAS
RELUCTANT TO GO TOO MUCH BELOW GUIDANCE BUT OVC SKIES BY MIDDAY
WOULD PROBABLY LEAD TO MAX TEMPS A CATEGORY OR EVEN MORE BELOW
EXCEPT POSSIBLY FAR SERN ZONES WHERE COLD AIR WILL BE SHALLOWEST.
INCREASING ISENTROPIC LIFT AHEAD OF APPROACHING UPPER LOW WILL
BRING A CHANCE OF RAIN BY AFTN SRN AND WRN ZONES AT LEAST...POSSIBLY
FARTHER NNE...BUT LIMITED CHCS TO THOSE ZONES AT THIS TIME.
MODELS ARE A LITTLE LESS CERTAIN OR EVEN AGREEABLE AS TO WHEN OR
IF A POSSIBLE LULL IN PRECIP CHANCES WILL OCCUR IN MON NIGHT-WED
TIME PERIOD. ALTHOUGH COVERAGE+INTENSITIES...I.E. PRECIP BECOMING
PATCHY VRY LIGHT RAIN OR DRIZZLY...MAY OCCUR TUE AFTN INTO TUE
NGT. THIS WOULD BE BEHIND INITIAL WARM CONVEYER BELT DRIVEN PRECIP
MON NGT AND BEFORE NEXT ROUND OCCURS AS LOW LEVEL JET CRANKS UP
AND GENEROUS H85 DWPTS SPREAD NORTH BY WED MORNING. PRECIP TYPE
SHOULD REMAIN LIQUID MUCH OF THE AREA...BUT NAM FORECAST SOUNDINGS
BY 12Z TUE INDICATED A FREEZING RAIN/SLEET MIX NORTH WHILE GFS WAS
SHAKINGLY STICKING TO GENERALLY ALL LIQUID NRN ZONES. QUICK LOOK
AT 00Z ECMWF SHOWED THAT MODEL CONTINUING TO WARM H85 TEMPS MONDAY
NIGHT ALONG WITH INCREASING THICKNESSES... ALSO GENERALLY
SUPPORTING KEEPING PRECIP ALL LIQUID ALL ZONES FOR NOW. BOTTOM
LINE...STILL SOME RISK OF A PERIOD OF FREEZING RAIN/SLEET FAR NWRN
ZONES FOR A PERIOD MON NIGHT/EARLY TUE...IF SURFACE TEMPS COULD
STAY BELOW FREEZING...BUT REALLY NOT MUCH SUPPORT FOR SNOW FOR OUR
FA EXCEPT PER NAM POSSIBLY NEAR SD BORDER.
AS SYSTEM APPROACHES TUE-WED PERIODS...TEMPS ABOVE SURFACE
CONTINUE MODERATING ELIMINATING ANY MIXED PRECIP RISK THAT MAY
OCCUR FAR N AS SURFACE GRUDGINGLY INCREASE. ELEVATED INSTABILITY
SPREADING INTO SRN ZONES AT LEAST COULD ALLOW A FEW TSTMS BY WED
AM...AND THESE MAY HAVE TO BE INCLUDED IN FUTURE FORECASTS IF
TRENDS PERSIST. CLOUDS/PRECIP WILL GENERALLY LEAD TO SMALL
DIURNAL TEMPERATURE RANGES. TRIED TO TIGHTEN THEM UP A LITTLE WED
BY RAISING A FEW LOWS TUE NGT...AND SIMILAR ADJUSTMENTS MAY BE
NEEDED IN LATER FORECASTS IF CONTINUITY SUGGESTS.
IT DOES LOOK LIKE PRECIP CHANCES BEGIN DECREASING THU NIGHT/FRI
BUT CAN/T REMOVE MOST AREAS ENTIRELY AS TRAILING SHORT WAVE
ENERGY PERSISTS. ALTHOUGH BOTH GFS AND ECMWF SUPPORTED A DRY
SATURDAY.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
648 AM CDT SAT OCT 26 2013
.AVIATION...
12Z TAFS FOR KOMA...KLNK...AND KOFK.
VFR CONDITIONS WILL CONTINUE THROUGH THE PERIOD AS HIGH
PRESSURE BUILDS INTO THE REGION BEHIND A COLD FRONT. NORTH
WINDS INCREASING TO AROUND 15 KTS 14Z-16Z THEN BECOMING
LIGHT AFTER 23Z.
&&
.PREV DISCUSSION... /ISSUED 303 AM CDT SAT OCT 26 2013/
DISCUSSION...
LITTLE CHANGE IN FORECAST CHALLENGE/CONCERN ITEMS. THE SHORT TERM
FOCUS REMAINS ON TEMPERATURES WHILE MEDIUM/LONGER TERM EMPHASIS
SHIFTS TOWARD PRECIPITATION...WHEN TO INCLUDE HIGHEST
PROBABILITIES AND WHETHER OR NOT SOMETHING OTHER THAN LIQUID
WILL FALL.
WIND SHIFT CURRENTLY WORKING THRU INTO EAST CENTRAL ZONES WILL
PROVIDE BRISK NNW WINDS AND COOLER TEMPERATURES TODAY.
HOWEVER...WITH FAVORABLE MIXING...I.E. NEARLY FULL SUNSHINE AND NW
WINDS...PLUS A THE START IN THE UPPER 30S OR WARMER...COULD ALLOW
A BIT OF A SUPER OFF SURFACE AT MAX HTG SO WOULD SUSPECT HIGHS
SHOULD AT LEAST REACH WARMER MET GUIDANCE BASED ON RAP AND OTHER
FORECAST SOUNDINGS. GENERALLY IN LINE WITH PREV FORECAST. A LATE
EVENING LOW STILL PROBABLY IN STORE FOR REGION TONIGHT AS TEMPS
STEADY LATE AS WINDS TURN SOUTHERLY. THEN SW WINDS AND EVEN WARMER
H85 TEMPS ON SUNDAY...COMPARED TO FRIDAY...WITH DRY AND SUNNY
CONDITIONS PREVAILING. THIS SHOULD ALLOW MAX TEMPS TO REACH A
CATEGORY OR MORE WARMER THAN FRIDAY...AND BOOSTED TOWARD WARMER
MET READINGS. WEAK WIND SHIFT ENTERING NRN ZONES BY LATE AFTN
SHOULD HAVE LITTLE IMPACT ON HIGHS BUT COOLER AIR PUSHING IN
BEHIND IT LATER IN THE EVENING/OVERNIGHT WILL. THIS LEADS US TO...
FORECAST UNCERTAINTIES THAT THEN BEGIN INCREASING NEXT WEEK. MAIN
ISSUE MONDAY WILL BE HOW QUICKLY CLOUDS INCREASE BECAUSE COOLER
AIR BELOW H85 WILL SET UP A FAIRLY STEEP INVERSION ABOVE 925-900
MB. NERLY SFC WINDS WILL LIMIT MIXING...ESPECIALLY IF CLOUDS
THICKEN UP BY MIDDAY OR SOONER...WHICH THEY COULD ACROSS SRN AND
WRN ZONES. BUT WITH TEMPS OFF SURFACE YET FAIRLY MILD WAS
RELUCTANT TO GO TOO MUCH BELOW GUIDANCE BUT OVC SKIES BY MIDDAY
WOULD PROBABLY LEAD TO MAX TEMPS A CATEGORY OR EVEN MORE BELOW
EXCEPT POSSIBLY FAR SERN ZONES WHERE COLD AIR WILL BE SHALLOWEST.
INCREASING ISENTROPIC LIFT AHEAD OF APPROACHING UPPER LOW WILL
BRING A CHANCE OF RAIN BY AFTN SRN AND WRN ZONES AT LEAST...POSSIBLY
FARTHER NNE...BUT LIMITED CHCS TO THOSE ZONES AT THIS TIME.
MODELS ARE A LITTLE LESS CERTAIN OR EVEN AGREEABLE AS TO WHEN OR
IF A POSSIBLE LULL IN PRECIP CHANCES WILL OCCUR IN MON NIGHT-WED
TIME PERIOD. ALTHOUGH COVERAGE+INTENSITIES...I.E. PRECIP BECOMING
PATCHY VRY LIGHT RAIN OR DRIZZLY...MAY OCCUR TUE AFTN INTO TUE
NGT. THIS WOULD BE BEHIND INITIAL WARM CONVEYER BELT DRIVEN PRECIP
MON NGT AND BEFORE NEXT ROUND OCCURS AS LOW LEVEL JET CRANKS UP
AND GENEROUS H85 DWPTS SPREAD NORTH BY WED MORNING. PRECIP TYPE
SHOULD REMAIN LIQUID MUCH OF THE AREA...BUT NAM FORECAST SOUNDINGS
BY 12Z TUE INDICATED A FREEZING RAIN/SLEET MIX NORTH WHILE GFS WAS
SHAKINGLY STICKING TO GENERALLY ALL LIQUID NRN ZONES. QUICK LOOK
AT 00Z ECMWF SHOWED THAT MODEL CONTINUING TO WARM H85 TEMPS MONDAY
NIGHT ALONG WITH INCREASING THICKNESSES... ALSO GENERALLY
SUPPORTING KEEPING PRECIP ALL LIQUID ALL ZONES FOR NOW. BOTTOM
LINE...STILL SOME RISK OF A PERIOD OF FREEZING RAIN/SLEET FAR NWRN
ZONES FOR A PERIOD MON NIGHT/EARLY TUE...IF SURFACE TEMPS COULD
STAY BELOW FREEZING...BUT REALLY NOT MUCH SUPPORT FOR SNOW FOR OUR
FA EXCEPT PER NAM POSSIBLY NEAR SD BORDER.
AS SYSTEM APPROACHES TUE-WED PERIODS...TEMPS ABOVE SURFACE
CONTINUE MODERATING ELIMINATING ANY MIXED PRECIP RISK THAT MAY
OCCUR FAR N AS SURFACE GRUDGINGLY INCREASE. ELEVATED INSTABILITY
SPREADING INTO SRN ZONES AT LEAST COULD ALLOW A FEW TSTMS BY WED
AM...AND THESE MAY HAVE TO BE INCLUDED IN FUTURE FORECASTS IF
TRENDS PERSIST. CLOUDS/PRECIP WILL GENERALLY LEAD TO SMALL
DIURNAL TEMPERATURE RANGES. TRIED TO TIGHTEN THEM UP A LITTLE WED
BY RAISING A FEW LOWS TUE NGT...AND SIMILAR ADJUSTMENTS MAY BE
NEEDED IN LATER FORECASTS IF CONTINUITY SUGGESTS.
IT DOES LOOK LIKE PRECIP CHANCES BEGIN DECREASING THU NIGHT/FRI
BUT CAN/T REMOVE MOST AREAS ENTIRELY AS TRAILING SHORT WAVE
ENERGY PERSISTS. ALTHOUGH BOTH GFS AND ECMWF SUPPORTED A DRY
SATURDAY.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
FOBERT
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
303 AM CDT SAT OCT 26 2013
.DISCUSSION...
LITTLE CHANGE IN FORECAST CHALLENGE/CONCERN ITEMS. THE SHORT TERM
FOCUS REMAINS ON TEMPERATURES WHILE MEDIUM/LONGER TERM EMPHASIS
SHIFTS TOWARD PRECIPITATION...WHEN TO INCLUDE HIGHEST
PROBABILITIES AND WHETHER OR NOT SOMETHING OTHER THAN LIQUID
WILL FALL.
WIND SHIFT CURRENTLY WORKING THRU INTO EAST CENTRAL ZONES WILL
PROVIDE BRISK NNW WINDS AND COOLER TEMPERATURES TODAY.
HOWEVER...WITH FAVORABLE MIXING...I.E. NEARLY FULL SUNSHINE AND NW
WINDS...PLUS A THE START IN THE UPPER 30S OR WARMER...COULD ALLOW
A BIT OF A SUPER OFF SURFACE AT MAX HTG SO WOULD SUSPECT HIGHS
SHOULD AT LEAST REACH WARMER MET GUIDANCE BASED ON RAP AND OTHER
FORECAST SOUNDINGS. GENERALLY IN LINE WITH PREV FORECAST. A LATE
EVENING LOW STILL PROBABLY IN STORE FOR REGION TONIGHT AS TEMPS
STEADY LATE AS WINDS TURN SOUTHERLY. THEN SW WINDS AND EVEN WARMER
H85 TEMPS ON SUNDAY...COMPARED TO FRIDAY...WITH DRY AND SUNNY
CONDITIONS PREVAILING. THIS SHOULD ALLOW MAX TEMPS TO REACH A
CATEGORY OR MORE WARMER THAN FRIDAY...AND BOOSTED TOWARD WARMER
MET READINGS. WEAK WIND SHIFT ENTERING NRN ZONES BY LATE AFTN
SHOULD HAVE LITTLE IMPACT ON HIGHS BUT COOLER AIR PUSHING IN
BEHIND IT LATER IN THE EVENING/OVERNIGHT WILL. THIS LEADS US TO...
FORECAST UNCERTAINTIES THAT THEN BEGIN INCREASING NEXT WEEK. MAIN
ISSUE MONDAY WILL BE HOW QUICKLY CLOUDS INCREASE BECAUSE COOLER
AIR BELOW H85 WILL SET UP A FAIRLY STEEP INVERSION ABOVE 925-900
MB. NERLY SFC WINDS WILL LIMIT MIXING...ESPECIALLY IF CLOUDS
THICKEN UP BY MIDDAY OR SOONER...WHICH THEY COULD ACROSS SRN AND
WRN ZONES. BUT WITH TEMPS OFF SURFACE YET FAIRLY MILD WAS
RELUCTANT TO GO TOO MUCH BELOW GUIDANCE BUT OVC SKIES BY MIDDAY
WOULD PROBABLY LEAD TO MAX TEMPS A CATEGORY OR EVEN MORE BELOW
EXCEPT POSSIBLY FAR SERN ZONES WHERE COLD AIR WILL BE SHALLOWEST.
INCREASING ISENTROPIC LIFT AHEAD OF APPROACHING UPPER LOW WILL
BRING A CHANCE OF RAIN BY AFTN SRN AND WRN ZONES AT LEAST...POSSIBLY
FARTHER NNE...BUT LIMITED CHCS TO THOSE ZONES AT THIS TIME.
MODELS ARE A LITTLE LESS CERTAIN OR EVEN AGREEABLE AS TO WHEN OR
IF A POSSIBLE LULL IN PRECIP CHANCES WILL OCCUR IN MON NIGHT-WED
TIME PERIOD. ALTHOUGH COVERAGE+INTENSITIES...I.E. PRECIP BECOMING
PATCHY VRY LIGHT RAIN OR DRIZZLY...MAY OCCUR TUE AFTN INTO TUE
NGT. THIS WOULD BE BEHIND INITIAL WARM CONVEYER BELT DRIVEN PRECIP
MON NGT AND BEFORE NEXT ROUND OCCURS AS LOW LEVEL JET CRANKS UP
AND GENEROUS H85 DWPTS SPREAD NORTH BY WED MORNING. PRECIP TYPE
SHOULD REMAIN LIQUID MUCH OF THE AREA...BUT NAM FORECAST SOUNDINGS
BY 12Z TUE INDICATED A FREEZING RAIN/SLEET MIX NORTH WHILE GFS WAS
SHAKINGLY STICKING TO GENERALLY ALL LIQUID NRN ZONES. QUICK LOOK
AT 00Z ECMWF SHOWED THAT MODEL CONTINUING TO WARM H85 TEMPS MONDAY
NIGHT ALONG WITH INCREASING THICKNESSES... ALSO GENERALLY
SUPPORTING KEEPING PRECIP ALL LIQUID ALL ZONES FOR NOW. BOTTOM
LINE...STILL SOME RISK OF A PERIOD OF FREEZING RAIN/SLEET FAR NWRN
ZONES FOR A PERIOD MON NIGHT/EARLY TUE...IF SURFACE TEMPS COULD
STAY BELOW FREEZING...BUT REALLY NOT MUCH SUPPORT FOR SNOW FOR OUR
FA EXCEPT PER NAM POSSIBLY NEAR SD BORDER.
AS SYSTEM APPROACHES TUE-WED PERIODS...TEMPS ABOVE SURFACE
CONTINUE MODERATING ELIMINATING ANY MIXED PRECIP RISK THAT MAY
OCCUR FAR N AS SURFACE GRUDGINGLY INCREASE. ELEVATED INSTABILITY
SPREADING INTO SRN ZONES AT LEAST COULD ALLOW A FEW TSTMS BY WED
AM...AND THESE MAY HAVE TO BE INCLUDED IN FUTURE FORECASTS IF
TRENDS PERSIST. CLOUDS/PRECIP WILL GENERALLY LEAD TO SMALL
DIURNAL TEMPERATURE RANGES. TRIED TO TIGHTEN THEM UP A LITTLE WED
BY RAISING A FEW LOWS TUE NGT...AND SIMILAR ADJUSTMENTS MAY BE
NEEDED IN LATER FORECASTS IF CONTINUITY SUGGESTS.
IT DOES LOOK LIKE PRECIP CHANCES BEGIN DECREASING THU NIGHT/FRI
BUT CAN/T REMOVE MOST AREAS ENTIRELY AS TRAILING SHORT WAVE
ENERGY PERSISTS. ALTHOUGH BOTH GFS AND ECMWF SUPPORTED A DRY
SATURDAY.
&&
.AVIATION...
06Z TAFS FOR KOMA...KLNK...AND KOFK.
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF CYCLE. WINDS WILL MOVE
FROM SOUTHWEST TO WESTERLY THROUGH THE NIGHT...BECOMING
NORTHWESTERLY BY MORNING. SPEEDS WILL INCREASE DIURNALLY...WITH
GUSTS SLACKENING AND SPEEDS DECREASING AROUND SUNSET. LIGHT WINDS
WILL BACK FROM NORTHWESTERLY TO SOUTHWESTERLY AFTER SUNSET.
MAYES
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
901 PM PDT FRI OCT 25 2013
.SYNOPSIS...WEAK HIGH PRESSURE WILL KEEP CONDITIONS RELATIVELY COOL
AND CLOUDY SATURDAY. A DRY COLD FRONT WILL BRING COOLER AND BREEZIER
CONDITIONS TO THE AREA SUNDAY INTO MONDAY. THE FIRST FREEZING
TEMPERATURES OF THE SEASON SEEM POSSIBLE FOR MANY LOCATIONS MONDAY
NIGHT. HIGH PRESSURE WILL THEN SLOWLY GIVE WAY TO A CHANCE OF
SHOWERS LATE IN THE WEEK.
&&
...FIRST FREEZE OF THE SEASON FOR MANY VALLEY LOCATIONS POSSIBLE
MONDAY NIGHT...
.EVENING UPDATE...NORTH TO EVEN SLIGHTLY NORTHEAST LOW LEVEL FLOW
HAS ALLOWED CLOUDS TO BREAK UP ALONG THE NORTH OREGON COAST AND LOWER
COLUMBIA RIVER THIS AFTERNOON AND EVENING. THIS SEEMS TO BE AT LEAST
IN PART BEING DRIVEN BY SURFACE HIGH PRESSURE STRENGTHENING AND
NOSING EASTWARD INTO WESTERN WASHINGTON.
IN GENERAL...A PERSISTENCE FORECAST SEEMS PRUDENT OVERNIGHT...AND
LARGELY STUCK WITH THAT FORECAST IDEA. AREAS WITH MIST AND FOG
CURRENTLY...LIKE THE SOUTHERN HALF OF THE WILLAMETTE VALLEY...WILL
LIKELY CONTINUE OVERNIGHT. MEANWHILE...A STRATUS DECK NEAR 1 TO 2KFT
WILL LIKELY PERSIST FURTHER NORTH OVER THE WILLAMETTE VALLEY AND
PREVENT FOG FORMATION. IN ADDITION...A CHANCE OF DRIZZLE WAS CUT
FROM THE FORECAST FOR THE COAST AND THE LOWER COLUMBIA RIVER WHERE
THE NORTHERLY LOW LEVEL FLOW PATTERN DOES NOT SEEM CONDUCIVE FOR
THIS TO OCCUR. HOWEVER...GIVEN THE ATMOSPHERE IS NEARLY SATURATED FOR
NEARLY 2KFT OVER THE SOUTHERN HALF OF THE WILLAMETTE VALLEY...AND
LIGHT UPSLOPE NORTHERLY WINDS SHOULD CONTINUE OVERNIGHT...DRIZZLE
WAS ADDED TO THE FORECAST FOR THE WILLAMETTE VALLEY SOUTH OF SALEM.
THE BEST CHANCES FOR DRIZZLE WOULD SEEM TO BE AROUND EUGENE...FERN
RIDGE RESERVOIR AND THE HILLS NORTH OF CORVALLIS.
BECAUSE SKIES HAVE CLEARED NEAR THE COLUMBIA RIVER MOUTH AND
DEWPOINTS HAVE FALLEN A COUPLE DEGREES...LOW TEMPERATURES WERE
DROPPED A FEW DEGREES IN THIS AREA. CONVERSELY...LOW TEMPERATURES WERE
NUDGED UP A COUPLE DEGREES FOR THE WILLAMETTE VALLEY WHERE THE LOW
CLOUDS SHOULD KEEP TEMPERATURES FROM DROPPING DRASTICALLY FROM THEIR
CURRENT LEVELS.
WITH ALL THAT SAID...THE RUC IS FAIRLY ADAMANT THAT 975MB
CONDENSATION PRESSURE DEFICIT VALUES WILL INCREASE SUBSTANTIALLY
FROM NORTH TO SOUTH OVER THE WILLAMETTE VALLEY TONIGHT. THIS WOULD
SEEM TO SUGGEST THAT THE BULK OF THE STRATUS AROUND 1-2KFT WOULD
DISSIPATE...SOMEWHAT SIMILARLY TO WHAT HAS BEEN OBSERVED SO FAR OVER
COLUMBIA...COWLITZ AND CLARK COUNTIES IN THE LAST TWO HOURS. AT THIS
POINT...I THINK THE RUC IS OVERDONE CONSIDERING THE STRATUS DECK
CURRENTLY SOUTH OF THE PUGET SOUND AND MIXING POTENTIAL DOES NOT
SEEM TO INCREASE SUBSTANTIALLY. IN THE OFF CHANCE THE STRATUS DECK
1-2KFT LITERALLY EVAPORATED OVERNIGHT...I THINK THE BOUNDARY LAYER WILL
REMAINED DECOUPLED ENOUGH THAT THE FOG AND MISTY CONDITIONS AT
SALEM...CORVALLIS AND EUGENE WILL LIKELY PERSIST...AND PERHAPS THESE
COULD EXPAND NORTHWARD.
OTHERWISE...THE COOL DOWN AND BREEZY NORTH AND EAST WINDS SUNDAY INTO
MONDAY LOOK ON TRACK. IT SEEMS MANY LOCATIONS WILL STAND A GOOD
CHANCE OF EXPERIENCING THEIR FIRST SOLID FREEZE OF THE SEASON MONDAY
NIGHT. /NEUMAN
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY...EXPECT A WIDESPREAD FREEZE
MONDAY NIGHT AS HIGH PRESSURE ALOFT STRENGTHENS...RESULTING IN GOOD
RADIATIONAL CONDITIONS...AND OFFSHORE GRADIENTS RELAX. THIS WILL BE
ADDRESSED IN MORE DETAIL OVER THE WEEKEND. THE UPPER RIDGE WILL
TRANSITION ACROSS THE FORECAST AREA TUE...BUT EXPECT MORE VALLEY FOG
AND LOW CLOUDS TUE NIGHT WITH NEAR-NEUTRAL SURFACE GRADIENTS. IT ALSO
APPEARS THE LONG STRETCH OF PLEASANT FALL WEATHER COMES TO AND END
AROUND HALLOWEEN. MODELS ARE ADVERTISING A TREND TOWARD A MORE ZONAL
THOUGH SLIGHTLY ANTICYCLONIC UPPER AIR PATTERN DEVELOPING FOR THE
LATTER PART OF NEXT WEEK...BRINGING IN A CHANCE OF PRECIPITATION TO
SOUTHWEST WASHINGTON AND NORTHWEST OREGON AT TIMES. A COMPLICATING
FACTOR IS A PAIR OF TYPHOONS IN THE WESTERN PACIFIC NEAR JAPAN THAT
ARE ABOUT TO BE ABSORBED INTO THE WESTERLIES. MODELS TEND TO HAVE
DIFFICULTY DEALING WITH TYPHOONS...TYPICALLY RESULTING IN CHAOTIC
SOLUTIONS. HOWEVER...THE FAVORED TREND IS FOR SYSTEMS TO BE WETTER
THAN MODELS INDICATE. HAVE TRENDED THE FORECAST POPS UP A SMALL
AMOUNT FOR LATER NEXT WEEK BUTEXPECT MORE ADJUSTMENTS WILL
EVENTUALLY BE NEEDED. WEISHAAR
&&
.AVIATION...HAVE SEEN MIXED SIGNALS OUT OF THE LAST COUPLE SETS OF
MODEL RUNS WITH REGARDS TO FOG/STRATUS. THE GFS IS RUNNING
SIGNIFICANTLY DRIER ACROSS THE LOW LEVELS WHILE THE NAM IS HOLDING
ON TO FAR MORE MOISTURE. SATELLITE IS SHOWING A NON-TRIVIAL AMOUNT
OF DRY AIR TRYING TO INTRUDE THE STRATUS NORTH OF THE COLUMBIA BUT
AT THE SAME TIME THE LOW DECK IS WELL ENTRENCHED INTO THE
WILLAMETTE VALLEY. WILL FOLLOW THE NAM DEPICTION HEADING INTO THE
06Z TAF PACKAGE WITH THE LIFR DECK OR VLIFR FOG IN PLACE FOR THE
INTERIOR THROUGH ABOUT 18 TO 20Z AS A FIRST GUESS THOUGH NEED TO
SAY CONFIDENCE IS BELOW AVERAGE. TOPS WILL BE SOMEWHAT
SHALLOW...PERHAPS 1800 TO 2000 FT MSL.
KPDX AND APPROACHES...A FINGER OF DRY AIR IS PUSHING SOUTH JUST
WEST OF THE FIELD BUT DONE EXPECT IT TO LAST VERY LONG. EXPECT IFR
CIGS TO PERSIST THROUGH MOST OF THE MORNING HOURS BEFORE SCATTERING
OUT FOR THE AFTERNOON AND EVENING. /JBONK
&&
.MARINE...00Z NAM HAS SPED UP THE ONSET OF SMALL CRAFT GUSTS A BIT
AND PUSHED THE WIND A BIT FURTHER NORTH. WILL ISSUE A SMALL CRAFT
ADVISORY FOR WINDS WITH THE EVENING PACKAGE BUT KEEP IT LIMITED TO
THE CENTRAL OUTER WATERS AND RUN IT THROUGH 11 AM SUNDAY FOR NOW.
THERE WILL BE PORTIONS OF THE NORTHERN WATERS THAT EXCEED 21 KTS
BUT THE AREA IS TOO SMALL TO WARRANT THE ADVISORY. THE INNER
WATERS SEEM LIKE THEY WILL BE SHELTERED FROM THE WINDS GIVEN AN
EVER SO SLIGHTLY OFFSHORE DIRECTION. SEAS NOT SEEING MUCH OF A
RESPONSE THROUGH WILL BE LARGELY WIND DRIVEN FOR THE CENTRAL
WATERS. 5...PERHAPS 6 FT TOTAL SEAS ARE EXPECTED THROUGH EARLY
SUNDAY.
LOW PRESSURE DROPPING OUT OF CANADA INTO THE GREAT BASIN AND
BUILDING HIGH PRES OVER THE INLAND PAC NW TIGHTENS THE SURFACE
GRADIENT LATER SUNDAY INTO MONDAY. THIS WILL BRING MODERATE EAST TO
NORTHEAST WINDS TO THE REGION BY MONDAY AFTERNOON...WITH GUSTS UP
TO 25 KT IN GAPS OF COASTAL TERRAIN. SEAS BRIEFLY BUILD UP TO 7 FT
SUN INTO MON...EASING TO 5 FT BY TUESDAY.
MODELS INDICATE RETURN TO MORE SEASONABLE WEATHER TOWARDS END OF
NEXT WEEK. WITH APPROACHING LOWS OVER THE GULF OF ALASKA...WILL
HAVE W SWELL BUILDING...REACHING NEAR 10 FT BY THU/FRI.
JBONK/ROCKEY/BURGESS
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 5 AM SATURDAY TO 11 AM PDT
SUNDAY FOR WATERS FROM CASCADE HEAD TO FLORENCE OR FROM 10
TO 60 NM.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
345 PM CDT SAT OCT 26 2013
.DISCUSSION...20Z SURFACE ANALYSIS PLACES A COLD FRONT FROM
SOUTHERN LAKE HURON SOUTHWEST BACK THROUGH SAINT LOUIS
AND EXTENDING SOUTHWEST ALONG THE I-44 CORRIDOR AND INTO A SURFACE
LOW LOCATED ACROSS THE RED RIVER VALLEY OF TEXAS/OKLAHOMA. A FEW
RAIN SHOWERS HAVE DEVELOPED ALONG A WARM FRONT NEAR
TEXARKANA...PRODUCING SOME RAIN SHOWERS ACROSS SOUTHWEST/SOUTH
CENTRAL ARKANSAS LATE THIS AFTERNOON. RAIN CHANCES FOR TONIGHT AND
AGAIN FOR MUCH OF NEXT WEEK REMAINS THE CHALLENGE IN THIS
FORECAST.
A WEAK COLD FRONT CURRENTLY LOCATED UPSTREAM OF THE MID SOUTH
ACROSS MISSOURI WILL CONTINUE TO SLOWLY DROP SOUTHEAST INTO THE
LOWER MISSISSIPPI VALLEY TONIGHT. LATEST SHORT TERM MODEL TRENDS
INCLUDING THE 3KM HRRR INDICATE THE BEST RAINFALL POTENTIAL WILL
REMAIN MAINLY SOUTH AND WEST OF THE FORECAST AREA TONIGHT WHERE
BETTER MOISTURE AND ISENTROPIC LIFT WILL RESIDE.
NONETHELESS...THINK BEST CHANCES RAIN /ISOLATED-SCATTERED
COVERAGE/ WILL BE PREDOMINANTLY ACROSS PORTIONS OF EAST ARKANSAS
AND NORTHWEST MISSISSIPPI. THIS FRONT WILL LINGER ACROSS NORTH
MISSISSIPPI ON SUNDAY WITH ISOLATED RAIN CHANCES STILL POSSIBLE
UNTIL THE FRONT PROGRESSES FURTHER SOUTH OF THE AREA.
WRF/GFS/ECMWF MODELS INDICATE THIS FRONT WILL RETURN BACK NORTH
AS A WARM FRONT MONDAY WITH ABOVE NORMAL TEMPERATURES RETURNING
FOR THE MIDDLE OF NEXT WEEK AND SHOWER AND THUNDERSTORM CHANCES
BEING CONFINED MOSTLY TO EAST/NORTHEAST ARKANSAS...AND THE
MISSOURI BOOTHEEL. GFS/ECMWF LONG TERM MODELS CONTINUE TO
DISAGREE WITH THE TIMING OF A DEEPER UPPER LEVEL TROUGH AND
ASSOCIATED COLD FRONT MOVING THROUGH THE LOWER MISSISSIPPI VALLEY
LATE NEXT WEEK. THE GFS CONTINUES TO BE ON THE QUICKER SIDE OF
GUIDANCE THAN THE ECMWF. WILL CONTINUE TO LEAN FORECAST TOWARDS
THE ECMWF UNTIL MODELS SHOW BETTER AGREEMENT AND RAIN CHANCES MAY
NEED TO BE RAISED UPWARD ACCORDINGLY IN SUBSEQUENT FORECASTS FOR
THURSDAY/FRIDAY.
&&
.AVIATION...
18Z TAF CYCLE (26/18Z-27/18Z)
VFR CONDITIONS WILL OCCUR THROUGH THE PERIOD. A WEAK COLD FRONT WILL
MOVE INTO THE REGION FROM THE NORTH OVERNIGHT CAUSING A SLIGHT
CHANCE OF SHOWERS. WINDS THIS AFTERNOON SW 8-12 KTS WITH OCCASIONAL
GUSTS AT KMEM...KMKL...AND KJBR. LIGHT WINDS TONIGHT AND SUNDAY
MORNING.
JCL
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 51 65 52 74 / 20 10 10 10
MKL 42 63 45 71 / 10 10 10 10
JBR 44 63 47 70 / 10 10 10 10
TUP 45 67 48 74 / 20 20 20 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
300 PM CDT SAT OCT 26 2013
.SHORT TERM.../NOW THROUGH SUNDAY NIGHT/...
A WEAK SHORTWAVE MOVING SOUTHEAST ACROSS OKLAHOMA AND NORTHERN TEXAS
WILL HELP PUSH THE PERSISTENT HIGH PRESSURE OVER THE SOUTHERN PLAINS
EASTWARD WITH ITS CENTERED OVER THE FLORIDA PANHANDLE. THIS WILL
SHIFT THE UPPER LEVEL FLOW MORE SOUTHEASTERLY THE REST OF TODAY AND
TONIGHT. AS THIS WAVE MOVES EASTWARD...SOUTHEAST WINDS WILL REMAIN
LIGHT TONIGHT WITH SCATTERED CLOUDS DUE TO THE MOISTURE COMING FROM
THE SOUTH INCREASING CLOSE TO THE SURFACE. KBRO 12Z SOUNDING SHOW THE
SLOW INCREASE OF PWATS REACHING 1.32 INCHES THIS MORNING. AS THE
ABUNDANT DRY AIR RAP AROUND THE PERIPHERY OF THE HIGH CONTINUES TO
MOVE INLAND WITH THE E/SE FLOW...THE CHANCE OF SHOWERS REMAIN VERY
LOW WITH A SILENT 10 ACROSS THE CWA TONIGHT AND SUNDAY. ISOLATED
SHOWERS WILL BE POSSIBLE BUT REMAIN BRIEF WITH NO SIGNIFICANT
RAINFALL EXPECTED TONIGHT AND SUNDAY. AS THE CLOUD COVERAGE INCREASES
TONIGHT...LOW TEMPERATURES WILL BE IN THE WARMER TREND THROUGH THE NIGHT
REACHING THE 70S ALONG THE RIVER AND THE UPPER 60S OVER THE NORTHERN
RANCHLAND.
INTO SUNDAY AND SUNDAY NIGHT...THE WINDS WILL REMAIN LIGHTER THAN
TODAY WITH RIDGE BUILDING FROM THE WEST AND PERSISTENT SOUTHEAST
FLOW ACROSS THE GULF. THE MOISTURE CONTENT IN THE LOWER LEVEL WILL
CONTINUE TO INCREASE BUT THE 1000-500 MB RH SHOW THE LOW LEVEL MOISTURE
IN THE 40 PERCENT LEVEL BETWEEN THE GFS AND THE NAM MODELS. THE LOW LEVEL
MOISTURE IN THE AREA WILL LIMIT THE RAINFALL POTENTIAL WITH A FEW SHOWERS
POSSIBLE MAINLY ALONG THE COAST. TEMPERATURES WILL WARM UP INTO THE
MID TO UPPER 80S WITH A FEW LOCATIONS IN THE UPPER VALLEY NEARLY REACHING
THE 90 DEGREES. NO SIGNIFICANT CHANGE EXPECTED THROUGH THE NIGHT AND
LOW TEMPERATURES WILL REACH THE MID TO LOW 70S ACROSS THE MID AND LOWER
VALLEY WITH MOST OF THE NORTHERN PORTION OF THE CWA IN THE MID 60S.
.LONG TERM.../MONDAY THROUGH SATURDAY/...LITTLE CHANGE IN MODEL AND FORECAST
THINKING FOR THIS LONG TERM PACKAGE. THIS WILL BE A REHASH OF THE
PREVIOUS FORECAST WITH LITTLE TO NO CHANGES WITH STILL A WIDE SPREAD
BETWEEN TIMING OF THE MEDIUM RANGE MODELS.
MAIN ELEMENTS OF CONCERN CONTINUE TO BE INCREASING SE-S WIND MONDAY
THROUGH WEDNESDAY WITH PEAK WINDS TUES/WED. ALSO...TEMPERATURES
CONTINUE TO INCREASE EACH DAY AS SOUTHERLY FLOW DEEPENS AND
EVENTUALLY VEERS A BIT WEST OF SOUTH AHEAD OF THE APPROACHING UPPER
TROUGH. AS MENTIONED LITTLE CHANGE WAS MADE TO THE INHERITED GRIDS.
UPPER TROUGH OFF THE PACIFIC COAST TO MAKE SLOW EASTWARD PROGRESS
THROUGH THE WEEK. SOUTH TEXAS TO LIE ON THE WESTERN END OF WARM
SUBTROPICAL RIDGE. MODEL CONSENSUS REMAINS IN THE ECMWF/CANADIAN
CAMP WITH A SLOWER EASTWARD MOVEMENT. HIGH PRESSURE RIDGE BUILDS
OVER THE PACIFIC NORTHWEST WITH THE UPPER TROUGH TO SINK MORE SOUTH
THEN KICK EAST INITIALLY. THE CLOSE TROUGH IS PROGGED TO OPEN UP
INTO A POSITIVELY TILTED TROUGH THURSDAY LIFT NORTHEAST WELL NORTH
OF TEXAS. THE FLOW OVER NORTHWEST MEXICO AND DEEP SOUTH TEXAS
BECOMES INCREASINGLY ZONAL TO EVEN SOUTHWEST. THIS IS NOT VERY
CONDUCIVE FOR FRONT PASSAGES. THE LATEST GFS MOS TEMPERATURES
GUIDANCE AS WELL AS THE 00Z ECMWF ONLY SHOW A 3 TO 5 DEGREE DROP IN
TEMPERATURES BEHIND A LATE THURSDAY/FRIDAY FRONT WHICH IS NOT EVEN
APPROACHING SEASONAL NORMALS FOR NOVEMBER. PRESSURE GRADIENT BEGINS
TO STRENGTHEN MONDAY MAINLY DUE TO GULF OF MEXICO RIDGE AND SOME
WEAK LEE TROUGH OVER THE SIERRA MADRE. GFS IS TRENDING A BIT STRONG
NEARING 30 MPH BETWEEN HWY 69E/69C BUT WILL TREND IN THE BREEZY
/15-25MPH/ RANGE AND HOLD OFF ON THE WINDY /20-30/UNTIL TUESDAY AND
WEDNESDAY AS THE TROUGH MOVES FARTHER EAST. 925-850MB WINDS JUST
SLIGHTLY LOWER BUT STILL DECENT IN THE 35-45 KNOT RANGE DEPENDING ON
MODEL OF CHOICE. AS FOR TEMPERATURES SAME THINKING WELL ABOVE NORMAL
WITH SOUTH WINDS AND INCREASING HEIGHTS AND THICKNESS AHEAD OF THE
UPPER TROUGH. EXPECT ANOMALIES TO REACH 10-15 DEGREES ABOVE NORMAL.
POST TROUGH/FRONT AS MENTIONED ONLY A 3 TO 5 DEGREE DROP IS
INDICATED AT THIS TIME. ONE ELEMENT OF NOTE IS THE INCREASE IN
MOISTURE. SOUTHERLY FLOW TO PUMP IN GULF MOISTURE THROUGH THE COMING
WEEK. PWATS ARE ADVERTISED TO JUMP ABOVE THE 1.5 THRESHOLD
TUESDAY AND 2 INCHES WEDNESDAY. THE DEEPER MOISTURE WILL MAKE IN
FEEL MUCH MORE HUMID BUT SHOWER ACTIVITY WILL BE LIMITED AT BEST
ON WEDNESDAY WITH A BIT TOO MUCH WIND AND NOT THE BEST DIRECTION
FOR AN ACTIVE SEA BREEZE. QUESTION ARISES FOR THURSDAY AND FRIDAY
AS THE UPPER TROUGH AND FRONT APPROACH. GUIDANCE FAVORS HIGHER END
CHANCE POPS BUT WILL MAINTAIN LOWER END WITH UNCERTAINTY IN TIMING
AND STRENGTH.
&&
.MARINE...NOW THROUGH SUNDAY NIGHT...A PERSISTENT HIGH PRESSURE OVER
THE NORTHERN GULF OF MEXICO WILL KEEP AN EASTERLY ONSHORE FLOW
FOR MOST OF THE SHORT TERM FORECAST. DUE TO THE LONG EASTERLY
FETCH ACROSS THE GULF WATERS...THE SEAS WILL CONTINUE TO BUILD UP
TO ADVISORY CRITERIA THROUGH THE NIGHT. A SMALL CRAFT ADVISORY IS
IN EFFECT FOR GULF WATERS THROUGH TONIGHT WITH A COASTAL FLOOD
STATEMENT AS THE SURF WATERS MOVES CLOSE TO THE DUNES. THE SEAS
WILL REMAIN HIGH THROUGH THE DAY WITH BREEZE CONDITIONS GRADUALLY
LOWERING INTO SUNDAY. SINCE TIDES HAVE BEEN 1FOOT ABOVE
PREDICTED...WITH HIGH TIDE TONIGHT...EXPECT THE WATERS TO PUSH UP
TO THE DUNE ONCE AGAIN TONIGHT. THIS WILL NOT CAUSE FLOODING BUT
WILL FORCE FOR SOME BEACH ACCESS TO BE CLOSE. THERE IS A HIGH RIP
CURRENT RISK DUE TO THE EASTERLY ONSHORE FLOW THROUGH SUNDAY
EVENING.
MONDAY THROUGH THURSDAY SOUTHEAST FLOW TO BEGIN TO STRENGTHEN
MONDAY BECOMING STRONG TUESDAY INTO EARLY THURSDAY. SMALL CRAFT
ADVISORIES ARE BECOMING MORE LIKELY AND POSSIBLY FOR AN EXTENDED
MONDAY THROUGH THURSDAY PERIOD. SCA/S WILL BE MORE PREVALENT
ACROSS THE LAGUNA MADRE DURING THE DAYTIME AND OFFSHORE AT NIGHT.
AS THE STRONGEST GRADIENT DEVELOPS WEDNESDAY NIGHT STRONGER SCA
CRITERIA WINDS COULD LINGER OVER THE LAGUNA WELL INTO THE EVENING
HOURS.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 73 83 75 85 / 10 10 10 10
BROWNSVILLE 72 88 74 87 / 10 10 10 10
HARLINGEN 70 88 73 88 / 10 10 10 10
MCALLEN 71 90 71 90 / 10 10 10 10
RIO GRANDE CITY 69 89 70 90 / 10 10 10 10
SOUTH PADRE ISLAND 75 83 76 84 / 10 10 10 10
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...HIGH RIP CURRENT RISK UNTIL 1 AM CDT SUNDAY FOR TXZ251-256-257.
COASTAL FLOOD ADVISORY FROM 7 PM THIS EVENING TO NOON CDT SUNDAY
FOR TXZ251-256-257.
GM...SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR GMZ150-155-
170-175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
67/59
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
443 AM EDT MON OCT 28 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 435 AM EDT MON OCT 28 2013
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW POTENT SHRTWV
ACCOMPANIED BY 140KT H3 JET MAX SLIDING ESEWD THRU ONTARIO IN THE NW
FLOW ALF BTWN MEAN TROF OVER ERN CANADA AND A RDG OVER THE ROCKIES.
ATTENDANT COLD FNT PUSHED THRU UPR MI LAST EVNG ACCOMPANIED BY SOME
-SHRASN MAINLY OVER THE NRN TIER COUNTIES AND WAS FOLLOWED BY SOME
GUSTY N WINDS THAT PEAKED AS HI AS 41 KT AT THE STANNARD ROCK
LIGHTHOUSE IN SCENTRAL LK SUP. ALTHOUGH THE LARGE SCALE PCPN HAS
DIMINISHED FOLLOWING THE EXIT OF THE DEEPER MSTR...SOME LES AIDED BY
THE ARRIVAL OF H85 TEMPS DOWN TO -10 TO -11C IS OCCURRING NEAR LK
SUP...MAINLY OVER THE NCENTRAL WHERE LLVL NNE FLOW BTWN SFC HI PRES
IN SASKATCHEWAN THE DEPARTING COLD FNT IS PRESENTING A SHARPER
UPSLOPE WIND COMPONENT. BUT EVEN HERE THE LES IS RATHER LIGHT...WITH
CONSIDERABLE DEEP LYR QVECTOR DVGC/SUBSIDENCE DROPPING THE INVRN
BASE TOWARD 4K FT AND SHARPENING ACYC LLVL FLOW WEAKENING THE NEAR
SFC CNVGC. THE NEAR SFC LYR IN THE INCOMING AIRMASS IS NOT OVERLY
MOIST EITHER...WITH SFC DEWPT AT CKC IN THE MN ARROWHEAD DOWN TO 12F
AT 05Z AND HAS RESULTED IN CLRG JUST UPWIND OF THE LK. 00Z INL/YPL
RAOBS ALSO SHOW THIS DRYNESS. BUT MORE SC LINGERS FARTHER TO THE N
INTO ONTARIO/SRN MANITOBA/NW MN. THERE IS PARTIAL CLRG OVER FAR NW
ONTARIO W THRU LK WINNIPEG CLOSER TO THE SFC HI CENTER AND WHERE THE
00Z RAOB FM THE PAS MANITOBA SHOWS INVRN BASE BLO H9...BUT EVEN HERE
BKN SC ARE PRESENT.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE LES AND LO CLD TRENDS.
TODAY...UNDER CONFLUENT NW FLOW ALF...SFC HI PRES NOW CENTERED OVER
SASKATCHEWAN IS PROGGED TO DRIFT OVER NW MN BY 00Z TUE. EXPECT GUSTY
WINDS EARLY THIS MRNG TO DIMINISH STEADILY WITH THE ARRIVAL OF
FLATTER PRES GRADIENT. HIER RES MODELS INDICATE THE MOST PERSISTENT
SHSN IN LLVL N-NE FLOW WL IMPACT THE HIER TERRAIN OF THE NCENTRAL
AND THE FAR W FM ONTONAGON TO IWD...WHERE MOISTENING OFF LK NIPIGON
IS INDICATED TO HAVE A POSITIVE IMPACT. GOING POPS APPEAR TO HAVE
THESE TRENDS IN HAND. BUT THE SHARP LLVL ACYC FLOW/LO INVRN BASE
BTWN 3-4K FT/PRESENCE OF DGZ ABV THE RELATIVELY SHALLOW LK MOISTENED
LYR WL LIKELY HOLD DOWN SN ACCUMS TO NO MORE THAN AN INCH OR SO
DESPITE FVRBL LK WATER-INVRN BASE DELTA T ARND 17C. ALTHOUGH THERE
IS SOME CLRG IMMEDIATELY UPSTREAM OF THE LK RIGHT NOW...SUSPECT THE
BKN-OVC SC A BIT FARTHER TO THE N-NW AND SUBSTANTIAL OVERWATER
INSTABILITY ARE SIGNS THE LO CLDS WL BE QUITE RESILIENT. SO TENDED
TOWARD THE LOWER END OF GUIDANCE FOR MAX TEMPS.
TNGT...SFC HI PRES CENTER IS PROGGED TO DRIFT ALMOST RIGHT OVER UPR
MI BY 12Z TUE. WHILE THIS TREND WOULD SUG THE SC WL DSPT AND LO
TEMPS WL PLUNGE UNDER PWAT FALLING BLO 0.25 INCH/LGT WINDS...
CONCERNED THERE IS A GOOD AMOUNT OF LO CLD OBSVD THIS MRNG UPSTREAM
TO THE HI CENTER THAT COULD WREAK HAVOC WITH LO TEMPS FCST. SOME HI
CLDS MAY ALSO FILTER INTO THE AREA. WITH THE LLVL FLOW BACKING MORE
NW WITHIN LLVL THERMAL TROF...SUSPECT THE SC WL BE MOST TENACIOUS E
OF MQT. MAINTAINED FLAVOR OF PREVIOUS FCST SHOWING THE LOWEST TEMPS
OVER THE INTERIOR W HALF AND SCENTRAL INTO THE TEENS...BUT TENDED TO
RAISE THE FCST MINS A BIT TO ACCOUNT FOR THE UNCERTAINTY ON CLRG
TRENDS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 435 AM EDT MON OCT 28 2013
BRIEF PATTERN CHANGE REMAINS ON TRACK FOR THIS WEEK AS SPLIT FLOW
DEVELOPS. UPPER TROUGH THAT HAS BEEN OVER THE GREAT LAKES RECENTLY
SLIDES ACROSS EASTERN CANADA WHILE CUTOFF LOW SLOWLY MOVES FROM THE
WEST COAST TO THE CENTRAL PLAINS. 00Z MODELS STILL SHOWING SOME
DIFFERENCES BUT ARE STARTING TO COME TOGETHER IN TERMS OF POSITION
OF PLAINS UPPER LOW THROUGH WEDNESDAY. A BIT MORE DIFFERENCE BY
THURSDAY...BUT EVEN HERE THERE IS DECENT MODEL CLUSTERING OF
STRENGTH AND TRACK OF SFC LOW 00Z THURSDAY THROUGH 18Z THURSDAY.
MORE DIFFERENCES BEGIN TO EMERGE LATER THURSDAY INTO FRIDAY MAINLY
WITH REGARD TO HOW QUICKLY THE LOW EXITS THE UPPER GREAT LAKES. LOW
PRESSURE MOSTLY RESULTS IN A RAIN EVENT FOR MID-LATE WEEK WITH SNOW
RE-ENTERING THE PICTURE BY NEXT WEEKEND AS COLDER AIR FILTERS ACROSS
THE GREAT LAKES IN WAKE OF THE LOW PRESSURE SYSTEM.
LARGE SPRAWLING HIGH PRESSURE OF 1033MB WILL BE CENTERED VERY NEAR
UPR MICHIGAN TO START THE DAY ON TUESDAY WHILE AN INITIAL WAVE OF
LOW PRESSURE FORMS IN THE SOUTHERN PLAINS. EVEN THOUGH A RIDGE OF
HIGH PRESSURE HOLDS AT THE SFC THROUGH TUESDAY NIGHT OVER THE UPPER
GREAT LAKES...HINT IS THERE FOR A WHILE THAT THERE MAY BE SOME LIGHT
PRECIP OVER THE AREA THROUGH THE EVENING. MAIN INSTIGATOR FOR THE
PRECIP IS SHORTWAVE DROPPING ACROSS NORTHERN ONTARIO IN NW FLOW ON
WESTERN EDGE OF RETREATING TROUGHING. MOST OF LARGER SCALE FORCING
FOR ASCENT FM SHORTWAVE /H7-H5 AND H5-H3 Q-VECTOR CONVERGENCE/ STAYS
NORTH OF CWA. HOWEVER...INCREASE IN MOISTURE AND WARM AIR ADVECTION
TEAMS UP WITH DIVERGENCE ALOFT FM JET STREAK SLIDING EAST TOWARD
QUEBEC TO GENERATE SOME MID-LEVEL LIFT. LEFTOVER ISSUE IS WHETHER
LOW-LEVEL DRY AIR OWING TO THE SFC HIGH WILL BE ERODED ENOUGH TO
RESULT IN PRECIP MAKING IT TO THE SFC. /THIS IS OF COURSE ASSUMING
THAT LOW CLOUDS AROUND TONIGHT DO IN FACT CLEAR OUT LATER TONIGHT OR
TUESDAY MORNING/. SINCE THE DRYING WILL NOT BE RE-INFORCED BY DRY
ADVECTION...THINK MID-LEVEL MOISTURE AND LIFT EVENTUALLY ALLOWS LGT
PRECIP TO MAKE IT TO SFC. SOUNDINGS FM THE NAM AND THICKNESSES
INDICATE MAINLY SNOW FOR PTYPE. ONLY SCNTRL WITH LGT SE WINDS OFF LK
MICHIGAN MAY SEE RAIN BE MAIN PTYPE.
WHERE SNOW OCCURS AS PTYPE...THERE IS A LEAST SOME CHANCE OF MINOR
ACCUMS AS...DESPITE IT HAPPENING IN THE AFTN/EVENING...BANDED SNOW
COULD FALL AT AN OKAY CLIP WITH STRONGER FORCING IN MID-LEVELS. NAM
WHICH IS GRANTED THE MOST AGGRESSIVE WITH QPF AND DURATION OF
HEAVIER QPF SHOWS SNOW ACCUMS OVER 2 INCHES OVER SOUTHWEST CWA 18Z
TUE THROUGH 06Z WED. WILL NOT GO THIS BULLISH YET AS THE NAM IS AN
OUTLIER...BUT WILL BUMP POPS UP TO HIGHER CHANCE RANGE. ECMWF/GEM-NH
AND UKMET ALSO GENERATING QPF OVR UPR MICHIGAN BUT NOT NEAR AS HEAVY
AS NAM. TIMING AND EXTENT OF SNOW SOMETHING TO KEEP AWARE OF AS IT
COULD IMPACT EVENING TRAVEL OVER SOUTHWEST UPR MICHIGAN AND MAYBE
INTO CNTRL AND EASTERN CWA.
DECENT AGREEMENT THAT LGT PRECIP TAPERS OFF BY LATER EVENING AS
MAIN JET STREAK MOVES FARTHER EAST AND MID-LEVEL MOISTURE DEPARTS.
LOW-LEVEL MOISTURE REMAINS THROUGH THE REST OF TUESDAY NIGHT WITH
VERY WEAK WINDS AS SFC RIDGE AXIS LINGERS. COULD SEE SOME FOG WITH
THIS SETUP IF MOISTURE THINS OUT MORE THAN SHOWN ON SOUNDINGS. AT
THE LEAST SOME STRATUS SHOULD PERSIST INTO WEDNESDAY. LOW-LEVEL
WINDS GRADUALLY BECOME MORE SOUTHEASTERLY TO THE NORTH OF WARM
FRONT...WHICH BASED ON SFC WINDS/DWPNT GRADIENT...COULD BE AS FAR
NORTH AS CNTRL WISCONSIN BY 00Z THURSDAY. SE WINDS MAY HOLD IN
STRATUS MOST OF THE DAY OVER UPSLOPE AREAS OF CNTRL UPR MICHIGAN
THANKS TO LESS MIXING DUE TO LOWER SUN ANGLE THIS TIME OF YEAR.
ELSEWHERE...WOULD EXPECT INCREASING HIGH AND MID CLOUDS OUT AHEAD
OF DEVELOPING PLAINS SYSTEM AND WARM FRONT. MAIN QUESTION FOR
WEDNESDAY IS WHETHER PRECIP MOVES BACK IN THROUGH THE DAY. GFS WOULD
SUGGEST SO...WHILE THE ECMWF/GEM-NH AND UKMET KEEP QPF SOUTH OF CWA
UNTIL WEDNESDAY NIGHT. EVEN GFS HAS SHOWN A TREND TOWARD DRIER
WEATHER HOLDING...AT LEAST OVER THE NORTHERN CWA. HAVE SLIGHT CHANCE
POPS GOING AND THAT PROBABLY WORKS FOR NOW...AT LEAST UNTIL MORE
SIGNAL SHOWS UP THAT WARM FRONT AND PRECIP WILL BE FARTHER NORTH.
SUPPOSE THERE COULD BE SOME DRIZZLE FM THAT PERSISTING LOW CLOUD
DECK AND UPSLOPE FLOW. SLIGHT CHANCES COVER THIS JUST FINE FOR NOW.
LOWERED MAX TEMPS OVER THE WEST HALF INTO LOWER 40S WITH PERSISTING
CLOUDS.
RAIN IS STILL ON FOR WEDNESDAY NIGHT AS PLAINS UPPER TROUGH HEADS
EAST AND PROPELS DEEPENING SFC LOW TOWARD UPR LAKES...VCNTY OF
NORTHERN WI OR UPR MICHIGAN BY 12Z THURSDAY WITH MSLP SOMEWHERE NEAR
990MB. MOISTURE ADVECTION AND WARM AIR ADVECTION AHEAD OF LOW WILL
COMBINE WITH STRONG DIVERGENCE ALOFT ON NOSE OF 140+ KT JET STREAK
ROARING NORTHEAST OUT OF THE CENTRAL PLAINS. PWATS OVER 1 INCH OR
OVER 200 PCT OF NORMAL COMBINE WITH THE FORCING TO SPREAD A SWATH OF
MODERATE RAIN ACROSS ALL CWA. STILL SOME SMALL TIMING DIFFERENCES AS
THE GFS/GEM-NH QUICKER IN BRINGING RAIN ACROSS THE AREA. ECMWF IS
SLOWER BY ABOUT 6 HRS. KEPT A BROADBRUSHED 80 PCT CHANCE FOR
WEDNESDAY NIGHT. REFINEMENTS TO TIMING CAN BE MADE LATER ON. DRY
SLOT LIKELY BECOMES A FACTOR INTO DAYTIME HOURS ON THURSDAY...YET
MAY SEE AN ADDITIONAL AREA OF ENHANCED RAIN FROM DEFORMATION
INDICATED BY H7-H5/H5-H3 Q-VECTOR CONVERGENCE. HIGHEST POPS ON
THURSDAY WILL BE IN THE EAST CLOSER TO LOW-LEVEL JET AXIS AND H85-H7
MOISTURE TRANSPORT. WARMEST DAY OF THE WEEK ON THURSDAY WITH MAX
TEMPS INTO THE 50S. BASED ON LOCATION OF DRY SLOT AND H7-H5 LAPSE
RATES...TSRA PROBABLY END UP FIRING JUST TO THE SOUTH AND EAST OF
CWA...SO LEFT THAT OUT FOR NOW. WINDS PROBABLY WILL BE A FACTOR
SOMETIME ALONG THE WAY AS WELL GIVEN THE DEEPENING LOW AND WITH
TIGHT PRESSURE GRADIENT/STRONG WIND FIELDS FORECAST IN THE VCNTY OF
THE LOW. BEST CHANCE FOR ADVY GUSTS WOULD BE ALONG LK MICHIGAN LATER
WEDNESDAY NIGHT INTO THURSDAY MORNING...THEN ALONG LK SUPERIOR ONCE
LOW MOVES BY THURSDAY NIGHT INTO FRIDAY MORNING.
MID-LEVEL TROUGHING LINGERS FROM FRIDAY INTO NEXT WEEKEND AND THERE
ARE INDICATIONS THERE COULD BE A COUPLE PERIODS OF ENHANCED PRECIP
CHANCES IN THE MEAN TROUGHING AS SHORTWAVES AND/OR RE-INFORCING COLD
FRONTS SLIDE THROUGH. COLDER AIR CHARGES BACK IN ON FRIDAY. BASED ON
1000-850MB AND 850-700MB THICKNESSES FM ECMWF/GFS SHOULD START TO
SEE SNOW MIXING IN ON FRIDAY OVER AT LEAST WEST HALF INTERIOR.
AIRMASS CHILL INTO NEXT WEEKEND IS SIMILAR TO RECENT STRETCH OF
COOLER TEMPS WITH H85 TEMPS DOWN BLO -6C BUT NOT QUITE TO -12C.
SINCE THERE LOOKS TO BE SOME DEEPER MOISTURE AROUND AS
WELL...PROBABLY WILL HAVE TO CONTEND WITH LAKE ENHANCED RAIN AND
SNOW SHOWERS AT TIMES. SOME SNOW ACCUMULATION WOULD BE FAVORED AT
TIMES FOR THE FAVORED LAKE EFFECT AREAS NEAR LK SUPERIOR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 128 AM EDT MON OCT 28 2013
RAPID PRESSURE RISE BEHIND SURFACE FRONT HAS RESULTED IN GUSTY NORTH
WINDS AT ALL THREE TAF LOCATIONS LATE THIS EVENING. AS SURFACE
RIDGING CONTINUES TO BUILD ACROSS THE UPPER GREAT LAKES OVERNIGHT
PRESSURE GRADIENT/WINDS SHOULD BEGIN TO DIMINISH TOWARDS MORNING.
MOIST NORTHERLY FLOW OFF LAKE SUPERIOR SHOULD KEEP MVFR CIGS INTO
THE DAY ON MONDAY BEFORE SKIES SCATTER OUT DURING THE AFTERNOON.
CONDITIONS ARE NOT VERY FAVORABLE FOR SIGNIFICANT LAKE EFFECT SNOW
OVERNIGHT BUT VSBYS COULD LOWER BRIEFLY TO 2-3 MILES AT IWD AND SAW
BRIEFLY OVERNIGHT TONIGHT IN SHSN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 435 AM EDT MON OCT 28 2013
WITH HI PRES BUILDING TOWARD THE UPPER GREAT LAKES...EXPECT N WINDS
UP TO 30 KTS EARLY THIS MORNING TO DIMINISH STEADILY THRU THE DAY
AND TO BECOME LIGHT TONIGHT AS THE HI CENTER MOVES OVER THE AREA.
THESE LIGHT WINDS LESS THAN 20 KTS STAY IN PLACE TUESDAY THROUGH
WEDNESDAY AS HIGH PRESSURE PERSISTS THEN EXPECT INCREASING SE-E
WINDS LATER WEDNESDAY NIGHT OUT AHEAD OF DEEPENING LOW PRESSURE IN
THE MIDDLE MISSISSIPPI RIVER VALLEY. LOW FORECAST TO LIFT ACROSS LK
SUPERIOR BY THURSDAY NIGHT. DEPENDING ON TRACK OF LOW...WINDS MAY
DIMINISH FOR A TIME ON THURSDAY. YET...ONCE THE LOW MOVES TO THE EAST
OF LK SUPERIOR...NORTHWEST WINDS INCREASE TO 30 KTS THURSDAY NIGHT
INTO FRIDAY. HIGH PRESSURE QUICKLY BUILDING IN ALONG WITH COLD AIR
ADVECTION COULD ALLOW FOR SOME GALES TO OCCUR. STRONG NORTHWEST WINDS
TO 30 KTS CONTINUE INTO NEXT WEEKEND. &&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...MZ
MARINE...KC/JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
130 AM EDT MON OCT 28 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 407 PM EDT SUN OCT 27 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A SHORTWAVE SWINGING SE
THRU NRN ONTARIO. WAA PATTERN AHEAD OF WAVE HAS PRODUCED SOME PCPN
ACROSS LAKE SUPERIOR. ALTHOUGH RADAR RETURNS ALSO BLOSSOMED ACROSS
MUCH OF UPPER MI...DRY AIR AT THE LOW-LEVELS HAS KEPT MOST OF THE
PCPN FROM REACHING THE GROUND. AT THE SFC...ASSOCIATED COLD FRONT IS
JUST NOW ENTERING NW LAKE SUPERIOR. REGIONAL RADAR IMAGERY AND SFC
OBS INDICATE SOME PCPN OCCURRING IN THE VCNTY OF AND BEHIND THE
FRONT.
AS SHORTWAVE CONTINUES TO SWING ACROSS NRN ONTARIO...ASSOCIATED COLD
FRONT WILL QUICKLY SWEEP SE ACROSS THE FCST AREA THIS EVENING.
HEALTHY PRES RISES OF 6-7MB/3HR WITH FAVORABLE ALIGNMENT OF THE
ISALLOBARIC WIND WITH GRADIENT WIND WILL LEAD TO GUSTY NRLY WINDS
BEHIND FRONT...ESPECIALLY CLOSE TO THE LAKE SUPERIOR SHORELINE AS
OVERWATER INSTABILITY STRENGTHENS (850MB TEMPS DROP FROM ROUGHLY
-4/-5C AT 00Z TO -9/-11C BY 06Z). WINDS WILL LIKELY GUSTS TO AROUND
40MPH AT EXPOSED LOCATIONS. OTHERWISE...EXPECT A PERIOD OF LAKE
ENHANCED PCPN ALONG COLD FRONT AS LOW-LEVEL CONVERGENCE AND DEEP
LAYER FORCING FROM SHORTWAVE ACT ON OVERWATER INSTABILITY
(LAKE-850MB DELTA-T AROUND 13C). AFTER A PERIOD OF SHRASN IN VCNTY
OF COLD FRONT...THERE WILL BE A TRANSITION TO N TO NE FLOW LES AS
LAKE-850MB DELTA-T INCREASES TO 17C OR BETTER. HOWEVER...THERE WILL
BE STRONG NEGATIVES WORKING AGAINST MUCH MORE THAN LIGHT LES.
FIRST...LOW-LEVEL WIND FLOW BECOMES SHARPLY ANTICYCLONIC AS SFC HIGH
PRES RIDGE QUICKLY NOSES SE INTO THE UPPER LAKES...AND SECOND...
INVERSION CRASHES TO 4KFT WITH DENDRITIC SNOW GROWTH TEMP ZONE
REMAINING ABOVE THE SHALLOW MOIST LAYER. LIKELY POPS STILL LOOK ON
TRACK FOR THE N TO NE FLOW FAVORED LOCATIONS...BUT SNOW
ACCUMULATIONS SHOULD BE MINIMAL (PERHAPS AN INCH OR TWO...INCLUDING
EVENING PCPN ALONG FRONT...WHERE STRONGEST UPSLOPING OCCURS SUCH AS
THE HURON MTNS). LATE IN THE NIGHT/EARLY MON MORNING...THERE ARE
SOME HINTS THAT MOISTENING FROM LAKE NIPIGON MAY SUPPORT A BAND OF
MORE PERSISTENT LES INTO FAR WRN UPPER MI AROUND KIWD/PORCUPINE
MTNS.
STRONG SFC HIGH PRES RIDGE WILL BUILD SE ACROSS THE UPPER LAKES
DURING MON. ALTHOUGH INVERSION BASE TEMP AROUND -10C PROVIDES A
LAKE-850MB DELTA-T AROUND 17C OR SO...LES WILL STRUGGLE MON DUE TO
SHARP ANTICYCLONIC FLOW AND A LOW INVERSION AT 3-4KFT. COMBINED WITH
EARLY SEASON NEGATIVE EFFECTS OF DAYTIME HEATING DISRUPTING LAKE
EFFECT PROCESSES...WILL STICK WITH THE IDEA OF LES ENDING EARLY IN
THE AFTN. ONLY POSSIBLE EXCEPTION MAY BE FOR SOME FLURRIES TO LINGER
ALONG THE TRAJECTORY DOWN WIND FROM LAKE NIPIGON. ALTHOUGH FLOW WILL
BE ANTICYCLONIC...MOISTURE PICKED UP OFF LAKE SUPERIOR WILL PROBABLY
LEAD TO QUITE A BIT OF STRATOCU THRU THE DAY ACROSS MUCH OF THE FCST
AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 332 PM EDT SUN OCT 27 2013
AT 00Z TUE...A 1035MB SFC HIGH WILL BE CENTERED OVER SRN MANITOBA
AND WILL WEAKEN SLIGHTLY WHILE BECOMING CENTERED OVER THE CWA BY TUE
MORNING. 850MB TEMPS WILL BE AROUND -8C AND WITH MOSTLY CLEAR SKIES
(AT LEAST INLAND)...MON NIGHT LOWS WILL FALL INTO THE TEENS INLAND
AND INTO THE 20S CLOSER TO LAKE SUPERIOR. THE SFC HIGH WILL MOVE TO
THE NE CONUS BY 00Z WED AS AN UPPER LOW SITS OVER THE INTERMOUNTAIN
WEST...WITH THE ASSOCIATED SFC LOW DEVELOPING LEEWARD OF THE CO
ROCKIES. THE SLY LOW LEVEL FLOW BETWEEN THESE SYSTEMS WILL BRING A
WARM FRONT TO JUST S OF THE CWA BY TUE AFTERNOON WHILE A WEAK
SHORTWAVE AND LEFT EXIT REGION OF AN UPPER JET MOVE NEAR OR OVER THE
CWA. THESE FORCING MECHANISMS MAY BRING SOME PRECIP TO PORTIONS OF
THE CWA TUE AFTERNOON/EVENING...WITH THE BEST CHANCES OF PRECIP OVER
THE SRN CWA. STILL UNCERTAIN ON IF/WHERE PRECIP WILL FALL...BUT ANY
PRECIP OVER THE CWA SHOULD FALL AS MOSTLY SNOW GIVEN ONLY A SHALLOW
WARM LAYER NEAR THE SFC. HIGHS ON TUE LOOK TO BE IN THE 30S TO
AROUND 40.
THEN THROUGH FRIDAY...THE FORECAST IS VERY DEPENDENT ON THE
TRACK/STRENGTH OF THE SYSTEM OVER THE WRN CONUS EARLIER IN THE WEEK.
WHILE MODELS AGREE ON GENERAL SETUP...THEY VARY SIGNIFICANTLY WITH
MORE SPECIFIC AND IMPORTANT DETAILS WITH THIS TYPE OF SYSTEM. THE
OVERALL IDEA IS THAT THE UPPER LOW WILL EJECT OUT INTO THE PLAINS
WHILE THE ASSOCIATED UPPER TROUGH BECOMES MORE NEGATIVELY TILTED AS
IT MOVES TOWARD THE CWA...THIS LEADS TO A DEEPENING OF THE SFC LOW
AS IT MOVES INTO THE GREAT LAKE REGION. MODEL VARIABILITY (BOTH
BETWEEN MODELS AND WITH INTER MODEL RUN TO RUN CONTINUITY) MAY SEEM
SMALL WITH RELATION TO THE TRACK/INTENSITY OF THE SYSTEM...BUT WITH
A FAIRLY COMPACT LOW IT WILL MAKE HUGE DIFFERENCES IN WIND/WAVE
FORECASTS AND WITH PRECIP AMOUNTS/TIMING. CONFIDENCE IN THESE
ASPECTS OF THE FORECAST ARE VERY LOW FOR THIS PERIOD...ESPECIALLY
SINCE MODELS WILL LIKELY CHANGE SIGNIFICANTLY WITH FUTURE RUNS AS IS
COMMON WITH THIS TYPE OF SYSTEM. WHAT IS MORE CERTAIN IS THAT MOST
(IF NOT ALL) PRECIP WILL BE RAIN GIVEN 850MB TEMPS INCREASING TO UP
TO 10C AHEAD OF THE SYSTEM...OR A BIT COLDER IF THE SYSTEM STAY S OF
THE CWA BUT STILL WARM ENOUGH FOR ALMOST ALL OF THE PRECIP TO BE
RAIN...AND AIR COLD ENOUGH FOR SNOW BEHIND THE SYSTEM DOES NOT
ARRIVE UNTIL THE SYSTEM IS WELL DOWNSTREAM OF THE CWA.
FRI NIGHT AND SAT WILL SEE INCREASING CHANCES OF PRECIP...WITH
INCREASING CHANCES OF THAT PRECIP BEING ALL SNOW WITH TIME. 850MB
TEMPS BEHIND THE SYSTEM WILL DECEASE FROM -2C AT 00Z SAT TO AROUND
-7C BY 00Z SUN. LOW LEVEL NW WINDS WILL BE SLIGHTLY CYCLONIC TO
NEUTRAL IN DIRECTIONAL CHANGE ACROSS LAKE SUPERIOR. CONDITIONS ARE
MORE UNCERTAIN FOR SUN AS MODELS DIFFER MUCH MORE SIGNIFICANTLY BE
LATER IN THE DAY...BUT LES SHOULD BE ABLE TO CONTINUE AT LEAST
THROUGH SAT NIGHT AND INTO SUN MORNING. GIVEN UNCERTAINTY OVERALL IN
EXTENDED FORECAST...JUST USED A CONSENSUS OF MODELS...ESPECIALLY FOR
WED THROUGH NEXT SUN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 128 AM EDT MON OCT 28 2013
RAPID PRESSURE RISE BEHIND SURFACE FRONT HAS RESULTED IN GUSTY NORTH
WINDS AT ALL THREE TAF LOCATIONS LATE THIS EVENING. AS SURFACE
RIDGING CONTINUES TO BUILD ACROSS THE UPPER GREAT LAKES OVERNIGHT
PRESSURE GRADIENT/WINDS SHOULD BEGIN TO DIMINISH TOWARDS MORNING.
MOIST NORTHERLY FLOW OFF LAKE SUPERIOR SHOULD KEEP MVFR CIGS INTO
THE DAY ON MONDAY BEFORE SKIES SCATTER OUT DURING THE AFTERNOON.
CONDITIONS ARE NOT VERY FAVORABLE FOR SIGNIFICANT LAKE EFFECT SNOW
OVERNIGHT BUT VSBYS COULD LOWER BRIEFLY TO 2-3 MILES AT IWD AND SAW
BRIEFLY OVERNIGHT TONIGHT IN SHSN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 407 PM EDT SUN OCT 27 2013
COLD FRONT WILL QUICKLY DROP SE ACROSS LAKE SUPERIOR OVER THE NEXT
SEVERAL HRS. WITH STRONG HIGH PRES RIDGING SE TOWARD LAKE
SUPERIOR BEHIND FRONT...HEALTHY PRES RISES OF 6-7MB/3HR WILL FOLLOW
THE FRONT. COMBINED WITH AN INFLUX OF COLDER AIR RESULTING IN STRONG
OVERWATER INSTABILITY...EXPECT A PERIOD OF NORTHERLY 35-40KT GALES
THIS EVENING OVER MUCH OF LAKE SUPERIOR. GALES WILL BE
SHORT-LIVED...ENDING AFTER MIDNIGHT AS PRES RISE MAX QUICKLY SHIFTS
S OF LAKE SUPERIOR. LIGHTER WINDS...MOSTLY UNDER 20KT...SHOULD THEN
PREVAIL LATER MON THRU EARLY WED AS THE HIGH PRES RIDGE SETTLES OVER
THE AREA. LATE WED THRU FRI THERE IS THE POTENTIAL FOR STRONGER
WINDS OF AT LEAST 15-25KT...AND POSSIBLY TO GALE FORCE...AS A LOW
PRESSURE SYSTEM LIFTS FROM THE PLAINS ACROSS THE GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 5 AM EDT EARLY THIS MORNING FOR LSZ248>251-
265>267.
GALE WARNING UNTIL 2 AM EDT /1 AM CDT/ EARLY THIS MORNING FOR
LSZ162-240>245-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...MZ
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
309 AM CDT Mon Oct 28 2013
.SHORT TERM: (Through Late This Afternoon)
Issued at 308 AM CDT Mon Oct 28 2013
One more day of quiet weather across the Bi-State Region as a weak
upper level ridge moves across the Mississippi Valley. Should see
plenty of sunshine today due to the dry air which remains locked in
place over the region; though higher clouds will be increasing later
in the day as the subtropical jet draws Pacific moisture up ahead of
the the strong cutoff low over California and Nevada. Surface
cyclogenesis will ramp up over eastern Colorado today which will
increase southerly flow across the southern Plains and Deep South.
This will help to develop a warm front between a strong Canadian
high diving into the Upper Midwest and warm moist Gulf of Mexico air
trying to build up from the south. The NAM suggests that the front
may make it much of the way through Missouri and perhaps parts of
southwest Illinois, while the GFS and RAP aren`t as aggressive.
Either way, not sure there will be much difference in sensible
weather other than higher levels of surface humidity. Surface
temperatures are nearly identical for today on all short range
guidance, so have followed guidance numbers closely.
Carney
.LONG TERM:
(Tonight through Sunday) Issued at 308 AM CDT Mon Oct 28 2013
(Tonight through Thursday Night)
Little change required as going forecast has a good handle on the
situation. Still appears that this will be an active period
beginning late tonight with the likelihood of a widespread soaking
rain with potential for a few strong thunderstorms.
Followed the ECMWF which has been the most consistent with the
overall evolution of the weather pattern the next few days. Most of
tonight will remain dry until strong moisture convergence moves into
central Missouri after 09Z on the nose of a 45kt low level jet.
This low level forcing will move in concert with a shortwave trough
across the CWA tomorrow morning. Will have likely or categorical
pops going over central Missouri starting late tonight and then
spread them eastward across eastern Missouri into southwest Illinois
tomorrow morning.
Then showers and thunderstorms will become more scattered on Tuesday
afternoon and Tuesday Night as the shortwave passes to the east.
The ECMWF depicts an upper ridge moving east across the Midwest
through 12Z Wednesday. Thereafter, strong mid level ascent will
set up between midday Wednesday until the trough currently over
the western CONUS passes through our area on Thursday. Strong
moisture transport and convergence will be occurring beneath this mid
level ascent ahead of the approaching attendant surface cold
front. Likely or categorical pops for showers and thunderstorms
are still warranted ahead of the front Wednesday into Thursday.
There will continue to be the potential for strong thunderstorms
during this period given the very strong low level and deep layer
shear. Risk remains conditional on the amount of instability that
will be available which will be dependent on how much precipitation
is occurring ahead of the front. Will go ahead a mention the
potential for a few strong thunderstorms in the Hazardous Weather
Outlook.
Will keep a lingering chance of showers on Thursday night behind the
cold front. MOS temperatures are in good agreement and generally
followed.
(Friday Through Sunday)
There is good agreement that late week into next weekend will be
dry behind Thursday`s cold front. Both the GFS/ECMWF brings a
second upper trough with an attendant cold front through the
Midwest on Friday, though forcing and moisture looks to be too
limited to warrant any mention of rain chances at this point. This
trough will then move east and upper heights will rise as a ridge
builds in from the west.
Britt
&&
.AVIATION: (For the 00z TAFs through 00z Monday Evening)
Issued at 618 PM CDT Sun Oct 27 2013
Winds will become sely on Mon but remain light aob 7 kts. Sky
expected to remain clear, with ci spreading over the area during
the day Mon. VFR conditions expected at all terminals except
perhaps steam fg at KSUS overnight.
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
111 AM EDT MON OCT 28 2013
.SYNOPSIS...
A WARMING TREND IS EXPECTED IN THE DAYS AHEAD WITH TEMPERATURES
RUNNING ABOVE NORMAL TUESDAY THROUGH MUCH OF THIS WEEK. A UPPER
LEVEL DISTURBANCE COULD BRING A FEW SHOWERS LATER TODAY. A COLD
FRONT WILL BRING UNSETTLED WEATHER FRIDAY AND SATURDAY FOLLOWED BY
COOLER AIR INTO THE REGION ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 130 AM MONDAY...NO SIGNIFICANT CHANGES ARE NEEDED TO THE
FORECAST. PREVIOUS DISCUSSION FROM 1000 PM FOLLOWS...
CLEAR SKIES PREVAILED OVER THE FORECAST AREA THIS EVENING BUT HIGH
CLOUDS AHEAD OF A GULF-STATES IMPULSE ARE POISED TO SPREAD ACROSS
THE REGION. CLOUD COVERAGE COULD VERY WELL BECOME BROKEN WITH CIRRUS
OVERNIGHT WHICH MAY DECELERATE THE DIURNAL TEMP CURVES AFTER 6Z/2AM.
CURRENT MINIMUM TEMPERATURE FORECASTS LOOK ON TARGET AND APPEAR TO
ACCOUNT FOR THE DECREASE IN RADIATIONAL COOLING POTENTIAL BETWEEN
6Z-11Z/2AM- 7AM...WITH MIDDLE AND UPPER 40S ACROSS THE AREA EXPECTED
AT DAYBREAK MONDAY.
LIGHT SOUTH SURFACE FLOW TO LGT/VRBL WINDS EXPECTED OVERNIGHT WITH
RELATIVELY DRY WESTERLY FLOW ABOVE THE SURFACE. COLUMN MOISTURE
REMAINS LOW WITH 00Z MONDAY CHS/MHX UPPER AIR SOUNDINGS DEPICTING
BETWEEN 0.66-0.84 INCHES OF PRECIPITABLE WATER. THE LIGHT SOUTH
WIND FLOW MAY ELEVATE DEWPOINTS A FEW DEGREES MOSTLY ALONG AND
NEAR THE COASTAL ZONES OVERNIGHT. THIS COULD GENERATE POCKETS OF
FOG LATE TONIGHT...BUT INCREASING CLOUD COVER SHOULD LIMIT EXTENT
AND DENSITY OF THE FOG AND NO PLANS TO INCLUDE IN ZONES AT THIS
TIME. NO MAJOR CHANGES TO ONGOING FORECAST.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...MODELS HAVE COME MORE INTO ALIGNMENT FOR MONDAY
REGARDING THE RISK FOR PRECIPITATION. NAM MOS HAS SHRUNK ITS POPS
CONSIDERABLY FROM 24 HOURS AGO WHILE GFS MOS HAS TWEAKED ITS POPS
HIGHER. THIS CONSENSUS SEEMS QUITE REASONABLE GIVEN THE DRY
SUB-CLOUD LAYER AND THE DEEP WESTERLY OR DOWNSLOPE FLOW. A SERIES OF
SHORTWAVE TROUGHS WILL MOVE ACROSS THE SOUTHEAST STATES THIS PERIOD.
THE STRONGEST ONE...ACROSS THE GULF COASTAL STATES THIS
AFTERNOON...WILL MOVE ACROSS THE EASTERN CAROLINAS DURING MON. THE
GFS HAS THIS FEATURE COMING THROUGH IN TWO PARTS...ONE EARLY IN THE
DAY AND THEN ANOTHER DURING THE AFTERNOON AND EVE. COLUMNAR MOISTURE
DOES INCREASE TO AN INCH AND A QUARTER ON MON. HOWEVER...SATURATION
OR NEAR SATURATION IS LARGELY CONFINED TO THE MID AND UPPER LEVELS.
HOWEVER...SOME INLAND LOCATIONS DO BRIEFLY SATURATE DOWN TO 4-5 KFT.
WE HAVE DECIDED TO INCLUDE A SLIGHT CHANCE OF A SHOWER ACROSS SOME
INLAND AREAS WHILE MENTIONING SPRINKLES ACROSS THE ENTIRE AREA. ANY
PRECIPITATION THAT DOES MEASURE WILL NOT AMOUNT TO MORE THAN A COUPLE
HUNDREDTHS AT MOST AND FOR THE VAST MAJORITY OF THE AREA...A TRACE
IS THE MOST WE SHOULD EXPECT. CONSIDERABLE CLOUD COVER SHOULD KEEP
TEMPS FROM GETTING AS WARM AS THEY OTHERWISE MIGHT GIVEN THE RISING
THICKNESS VALUES. HOWEVER...THE DAILY WARMUP WILL STILL CONTINUE...
WITH HIGHS REACHING THE LOWER TO MID 70S. A LEFT OVER SPRINKLE NEAR
THE COAST IS POSSIBLE MON EVE...OTHERWISE IT WILL BE DRY MON NIGHT.
THE CLOUD COVER SHOULD DIMINISH AS A MID-LEVEL SHORTWAVE EXITS THE
COAST DURING THE EVE...ALLOWING FOR DRYING TO TAKE PLACE ALOFT. LOWS
SHOULD ONLY DROP TO THE UPPER 40S TO LOWER 50S OVERNIGHT MON.
TUE AND TUE NIGHT...A RIDGE BEGINS TO BUILD JUST TO OUR W...
ESTABLISHING A MORE NW FLOW ALOFT ACROSS THE FORECAST AREA. A WEAK
PERTURBATION IN THIS FLOW MAY MOVE ACROSS THE AREA TUE NIGHT. MODEL
SOUNDINGS DO SHOW CONSIDERABLE DRY AIR IN THE MID LEVELS AT THIS
TIME. GIVEN THE DIURNAL TIMING WILL NOT BE FAVORABLE FOR ANY
CONVECTION WHICH DOES DEVELOP UPSTREAM TO PERSIST AS IT APPROACHES
THE FORECAST AREA...WILL INCREASE POPS TO JUST BELOW THRESHOLD FOR
MEASURABLE PRECIPITATION AT THIS TIME. HOWEVER...LATER FORECASTS MAY
OPT TO INCLUDE A SMALL CHANCE FOR A SHOWER OR SPRINKLES...ESPECIALLY
IF THE LIFT PORTRAYED BY SOME OF THE MODELS PERSISTS. A LITTLE LESS
IN THE WAY OF THICK CLOUDS ON TUE AS COMPARED TO MON SHOULD ALLOW
TEMPS TO EXCEED WHAT IS CONSIDERED NORMAL FOR THE LAST DAYS OF
OCT...AND THAT HAS NOT BEEN THE CASE SINCE THE MIDDLE OF THE MONTH.
HIGHS ARE EXPECTED TO BE WELL UP IN THE 70S...COOLEST AT THE COAST
DUE TO SEABREEZE INFLUENCES. THICK CLOUD COVER SHOULD LINGER WELL
INTO THE NIGHT AND THESE CLOUDS SHOULD HELP KEEP TEMPS FROM DROPPING
BELOW 50 DEGREES...EVEN INLAND.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 3 PM SUNDAY...EASTWARD PROGRESSION OF HIGH PRESSURE ON
WEDNESDAY WILL PUT THE CENTER OF THE AIRMASS OFF THE COAST WEDNESDAY
NIGHT. THIS PAVES THE WAY FOR SOME INFLUX OF WARMER AND HIGHER
DEWPOINT AIR. AS THE MOISTURE CONTINUES TO INCREASE MODELS HINTING
AT PERHAPS SOME SMALL RAIN CHANCES AS EARLY AS THURSDAY NIGHT. THIS
IS WELL AHEAD OF THE COLD FRONT...THE EXACT TIMING OF WHICH IS NOT
VERY SOLID AMONGST VARIOUS MODELS. LOW LEVEL JETTING SEEMS TO BE THE
MAIN FORCING AND WILL MAINTAIN THE LOW POPS OF THE CURRENT FORECAST.
THE SLOW MOVING COLD FRONT SHOULD CROSS THE REGION FRIDAY NIGHT
ACCORD TO GFS AND EC...THE GEM IS QUITE A BIT FASTER BUT AN OUTLIER.
MODELS SEEM TO BE IN FAIR AGREEMENT REGARDING QPF WITH A GENERAL 2
TO 4 TENTHS OF AN INCH AREA-WIDE. MOST OF THE PERIOD WILL FEATURE
ABOVE CLIMO TEMPERATURES EXCEPT FOR THE POST-FRONTAL LATTER PART OF
THE WEEKEND.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...VFR CONDITIONS ARE EXPECTED EARLY THIS MORNING WITH
LIGHT WINDS AND INCREASING CIRRUS. CANNOT RULE OUT PATCHY AREAS OF
GROUND FOG...ESPECIALLY AT KCRE.. CLOUD CEILINGS LOWER TO 9-12KFT
AFTER DAYBREAK WITH AN APPROACHING UPPER LEVEL SYSTEM. ASIDE FROM
PATCHY LIGHT RAIN OR SPRINKLES INLAND NO SIGNIFICANT WX IS EXPECTED.
LIGHT WINDS WILL CONTINUE.
EXTENDED OUTLOOK...EARLY MORNING FOG POSSIBLE TUESDAY AND WEDNESDAY.
CHANCE OF SHOWERS LATE THURSDAY INTO FRIDAY WITH AN APPROACHING COLD
FRONT. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 130 AM MONDAY...NO SIGNIFICANT CHANGES NEEDED TO THE FORECAST.
LATEST HIGH-RES MODELS LIKE THE HRRR AND RUC SUGGEST PREVAILING WIND
DIRECTIONS MAY BECOME NORTHEASTERLY OVER THE NEXT FEW HOURS...WITH
WIND SPEEDS REMAINING 5 KNOTS OR LESS. PREVIOUS DISCUSSION FROM 1000
PM FOLLOWS...
A FRIENDLY MARINE ENVIRONMENT OVERNIGHT EXPECTED AS HIGH PRESSURE
SOUTH OF THE AREA SLIDES EAST. SURFACE GRADIENT WILL REMAIN WEAK
THROUGH THE END OF THE PERIOD. LIGHT WEST TO SOUTHWEST WINDS MAY
BECOME LIGHT AND VARIABLE OVERNIGHT. SEAS 1.5-2 FEET THROUGH
DAYBREAK MONDAY AND MOSTLY IN ESE WAVES EVERY 8 SECONDS WITH A VERY
LIGHT CHOP TO A SEMI-GLASSY SEA SURFACE CHARACTER INTO SUNRISE
MONDAY.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...HIGH PRESSURE WILL SIP OFF THE MID-ATLANTIC
COAST LATE MON AND MON NIGHT. FLOW AROUND THIS FEATURE WILL
INITIALLY BRING NE WINDS ACROSS THE WATERS...BUT THE WINDS WILL VEER
TO THE E AND LIKELY SE ACROSS THE NEAR SHORE WATERS AS THE SEABREEZE
CIRCULATION DEVELOPS MON AFTERNOON. A MUCH STRONGER AREA OF HIGH
PRESSURE WILL PUSH SE OUT OF CANADA AND ACROSS THE NORTHEAST STATES
TUE AND TUE NIGHT. WINDS ACROSS THE WATERS SHOULD RETURN TO NE
OVERNIGHT MON AND CONTINUE FROM THE NE OR E FOR THE REMAINDER OF THE
PERIOD. WINDS ACROSS THE NEAR SHORE WATERS WILL LIKELY SHIFT TO THE
SE TUE AFTERNOON AS ANOTHER SEABREEZE CIRCULATION ESTABLISHES
ITSELF. THE PRESSURE GRADIENT WILL BE SLACK THIS PERIOD...KEEPING
WIND SPEEDS UNDER 10 KT. SEAS WILL BE 1 TO 2 FT...WITH PERHAPS SOME
3 FT SEAS DEVELOPING LATE TUE AND TUE NIGHT ACROSS THE OUTERMOST
NORTHERN WATERS AS A 9 TO 11 SECOND EASTERLY SWELL STRENGTHENS
SLIGHTLY.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 3 PM SUNDAY...LIGHT WINDS AND MINIMAL SEAS ON WEDNESDAY AS
HIGH PRESSURE MOVES EAST ACROSS THE AREA. THOUGH LIGHT...WINDS WILL
BE TURNING CLOCKWISE IN DIRECTION MAINLY LATE IN THE DAY INTO THE
NIGHTTIME HOURS. WE THEN RATHER QUICKLY GET INTO A MODERATE RETURN
FLOW REGIME ON THURSDAY. THIS CONTINUES ON FRIDAY AS A COLD FRONT
APPROACHES FROM THE WEST. THE SLIGHT INCREASE IN GRADIENT ASSOCIATED
WITH THE APPROACH OF THE FRONT COULD PUSH SEAS UP TO SMALL CRAFT
ADVISORY REALM.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MJC/TRA
SHORT TERM...RJD
LONG TERM...MBB
AVIATION...SGL/TRA
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
256 AM EDT MON OCT 28 2013
.SYNOPSIS...
LOW PRESSURE PASSES SOUTH OF THE AREA TODAY. A WARM FRONT MOVES
NORTHWARD TUESDAY NIGHT AND WEDNESDAY...BRINGING MILDER AIR. STRONG
COLD FRONT WITH SHOWERS THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
NOT MUCH CHANGE IN FCST THINKING FROM DAY SHIFT. DID ELECT TO BUMP
UP POPS ACROSS SW VA INTO LKLY MID TO LATE MORNING PER LATEST MDL
RUNS. TIGHT POP GRADIENT WITH CHC GETTING INTO COAL FIELDS TO SE
WV...WITH NOTHING N OF THERE. ALSO LOOKING AT A TIGHT GRADIENT TO
SKY GRIDS AS WELL. WENT WITH SOLID OVC ACROSS SW VA AND S WV TDY.
HARD TO SAY IF OVC REACHES AS FAR N AT HTS TO CRW CORRIDOR. DID
ALLOW FOR BKN COVERAGE THOUGH WITH CIRRUS ACROSS SE OH AND N WV.
UPR LVL DISTURBANCE RESPONSIBLE FOR WX TDY SHIFT E OF CWA THIS
AFTN AND BEGIN TO QUICKLY RAMP DOWN POPS THIS AFTN ACROSS S ZONES.
ABUNDANCE OF LLVL MOISTURE WILL LINGER THOUGH THROUGH THIS AFTN
AND A GOOD CHUNK OF THE NIGHT ACROSS S WV/SW VA...THUS KEPT
PESSIMISTIC SKY COVERAGE ACROSS THOSE LOCALES WITH SOME CIRRUS
ELSEWHERE.
INGESTED LATEST HRRR AS A BASE FOR TEMPS TDY AND
TONIGHT...TWEAKING S ZONES FOR COOLER WX PER CLDS/SHRA THREAT.
TRIED TO GO TOWARD WARMER MET ACROSS SE OH AND N WV WHERE AT LEAST
FILTERED SUN WILL BE REALIZED. SAME GENERAL THINKING HOLDS TONIGHT
AS WELL...WITH WARMER READINGS ACROSS SW VA AND S WV...WITH COOLER
READINGS FOR SE OH AND N WV.
&&
.SHORT TERM /TUESDAY THROUGH FRIDAY NIGHT/...
NAM IS MUCH STRONGER WITH A FEATURE TUESDAY NIGHT THAN OTHER
MODELS...BUT MUCH OF THIS ENERGY CAN BE TRACED BACK TO CONVECTIVE
FEEDBACK IN THE MID WEST. THEREFORE...WILL KEEP POPS LOW AS GFS
WOULD KEEP MOST PRECIPITATION TO OUR NORTHWEST. MODELS ARE FAIRLY
CONSISTENT WITH A COLD FRONT MOVING THROUGH THURSDAY NIGHT.
THEREFORE...WILL RAISE POPS THURSDAY NIGHT...AND REMOVE POPS BEHIND
FRONT FRIDAY AFTERNOON AND EVENING.
&&
.LONG TERM /SATURDAY THROUGH SUNDAY/...
GENERALLY FOLLOWED WPC THINKING WITH THE EXTENDED PORTION OF THE
FORECAST...WITH A LEANING TOWARDS THE EC/CMC PER ENSEMBLE SUPPORT.
UPPER RIDGE AXIS OVER THE FORECAST AREA AT THE OUTSET OF THE PERIOD
WILL QUICKLY PUSH OFF TO THE EAST WITH A POTENT SYSTEM PUSHING OUT
OF THE CENTRAL ROCKIES TOWARDS THE UPPER MIDWEST...AND SFC COLD
FRONT MARCHING EASTWARD ACROSS THE MISS VALLEY. BASED ON THE SLOWER
PROGRESSION OF NWP CONSENSUS...LOOKS LIKE THURSDAY WILL BE WARM WITH
THE BULK OF THE PRECIP HOLDING OFF UNTIL THURSDAY NIGHT AND FRIDAY
MORNING WITH THE COLD FRONT. PRECIP EXITS TO THE EAST FRIDAY
AFTERNOON...BUT SW FLOW ALOFT CONTINUES OVER THE AREA AS UPPER
TROUGH CONTINUES TO DIG ACROSS THE GREAT LAKES AND OHIO RIVER
VALLEY. AS THE TROUGH MOVES OVERHEAD SATURDAY...WILL CONTINUE SLIGHT
CHANCE POPS MAINLY ACROSS THE NORTHERN ZONES AND EASTERN MOUNTAINS.
FLOW TURNS NORTHWEST BEHIND THE TROUGH AXIS ON SUNDAY YET WITH SOME
LLVL MOISTURE TRAPPED...WILL KEEP THE SLIGHT CHANCE POPS IN ROUGHLY
THE SAME LOCATIONS AS SATURDAY. TEMPERATURES WILL BE PROGRESSIVELY
COOLER WITH EACH PASSING DAY THROUGH THE EXTENDED...DROPPING FROM
THE LOWER 70S LOWLANDS ON THURSDAY TO AROUND THE 50 DEGREE MARK BY
SUNDAY FOR THE LOWLANDS.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
FEW TO SCT 4 TO 5 THSD FT CLDS INTO MORNING HRS ALONG AND N OF I64
CORRIDOR. ACROSS THE S...HAVE OVC CONDITIONS SPREADING N THRU SW
VA INTO S WV PREDAWN. THINK MUCH OF THESE REMAIN LOW END
VFR...SAVE FOR SOME MVFR CIGS FOR S MTNS INCLUDING KBKW. HAVE SOME
PREDAWN MVFR RVR VALLEY FG FOR KPKB AND KEKN.
UPR LVL SYS RESPONSIBLE FOR INCREASE IN CLDS WILL PASS S OF AREA
TDY. HOWEVER SCT SHRA EXPECTED FOR SW VA AND SE WV. HAVE VCSH IN
KBKW TAF WITH CHC NOT THAT GREAT ATTM. KEPT MVFR CIGS GOING
THOUGH. TOUGH TO SAY WHETHER OVC REACHES KHTS TO KCRW TDY BUT DID
INSERT BKN LOW END VFR CLDS IN FOR TDY. JUST HAVE SOME CIRRUS SE
OH/N WV FOR TDY.
UPR LVL SYS PASSES E OF AREA THIS AFTN...TAKING SHRA THREAT WITH
IT. HOWEVER ABUNDANT LLVL MOISTURE WILL REMAIN ACROSS SW VA AND S
WV TONIGHT WHICH MAY HOLD IN MVFR CIGS FOR KBKW. OTHERWISE JUST
SOME PASSING CIRRUS SE OH/N WV WHERE SOME LATE LIFR/IFR RVR FG MAY
BE REALIZED.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATIVE SCENARIOS: OVC DECK MAY MAKE IT INTO KHTS/KCRW FOR
TDY...BUT STILL WOULD REMAIN VFR.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 10/28/13
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY H H H H H M M M H H H H
HTS CONSISTENCY H H M M M M M M H H H H
BKW CONSISTENCY H H M H H H H H H H H H
EKN CONSISTENCY M M H H M M M M H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z TUESDAY...
IFR OR WORSE IN RVR VALLEY FG POSSIBLE TUES MORNING ACROSS SE OH/N
WV. IFR POSSIBLE IN SHOWERS THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/50/30
NEAR TERM...30
SHORT TERM...RPY
LONG TERM...ARJ
AVIATION...30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
239 AM EDT MON OCT 28 2013
.SYNOPSIS...
OW PRESSURE PASSES SOUTH OF THE AREA TODAY. STRONG SOUTHWEST FLOW
BRINGS MILDER AIR AND SHOWERS BY MID WEEK. COLD FRONT WITH SHOWERS
CROSSES FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
NOT MUCH CHANGE IN FCST THINKING FROM DAY SHIFT. DID ELECT TO BUMP
UP POPS ACROSS SW VA INTO LKLY MID TO LATE MORNING PER LATEST MDL
RUNS. TIGHT POP GRADIENT WITH CHC GETTING INTO COAL FIELDS TO SE
WV...WITH NOTHING N OF THERE. ALSO LOOKING AT A TIGHT GRADIENT TO
SKY GRIDS AS WELL. WENT WITH SOLID OVC ACROSS SW VA AND S WV TDY.
HARD TO SAY IF OVC REACHES AS FAR N AT HTS TO CRW CORRIDOR. DID
ALLOW FOR BKN COVERAGE THOUGH WITH CIRRUS ACROSS SE OH AND N WV.
UPR LVL DISTURBANCE RESPONSIBLE FOR WX TDY SHIFT E OF CWA THIS
AFTN AND BEGIN TO QUICKLY RAMP DOWN POPS THIS AFTN ACROSS S ZONES.
ABUNDANCE OF LLVL MOISTURE WILL LINGER THOUGH THROUGH THIS AFTN
AND A GOOD CHUNK OF THE NIGHT ACROSS S WV/SW VA...THUS KEPT
PESSIMISTIC SKY COVERAGE ACROSS THOSE LOCALES WITH SOME CIRRUS
ELSEWHERE.
INGESTED LATEST HRRR AS A BASE FOR TEMPS TDY AND
TONIGHT...TWEAKING S ZONES FOR COOLER WX PER CLDS/SHRA THREAT.
TRIED TO GO TOWARD WARMER MET ACROSS SE OH AND N WV WHERE AT LEAST
FILTERED SUN WILL BE REALIZED. SAME GENERAL THINKING HOLDS TONIGHT
AS WELL...WITH WARMER READINGS ACROSS SW VA AND S WV...WITH COOLER
READINGS FOR SE OH AND N WV.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
UNSETTLED WEATHER GRADUALLY RETURNS TO THE CWA. MONDAY NIGHT
FEATURES WEAK WAVE PUSHING OFF TO THE EAST...WITH A SLIGHT CHANCE
OF SHOWERS ACROSS EXTREME SOUTHERN ZONES. PRECIPITATION WILL BE
LIGHT MONDAY NIGHT...AND MAIN EFFECT WILL BE ON KEEPING OVERNIGHT
LOWS ACROSS THE SOUTH SEVERAL DEGREES WARMER THAN NORTH WITH THE
INCREASE IN CLOUD COVER.
WARM FRONTAL BOUNDARY WILL THEN MOVE NORTH ACROSS THE CWA TUESDAY
INTO WEDNESDAY. THIS WILL CREATE A CHANCE OF SHOWERS AREA WIDE.
MODELS VARY ON THE TIMING OF THE FRONTAL BOUNDARY MOVEMENT...AND
INDIVIDUAL WAVES. NAM INDICATES A SURFACE LOW TREKKING EAST ACROSS
THE NORTH ON TUESDAY NIGHT/EARLY WEDNESDAY...WHICH MAY PROVIDE A
HIGHER CHANCE FOR POPS UP NORTH THAN CURRENTLY FORECAST...WHILE 00Z
ECMWF BRINGS A WAVE STRAIGHT ACROSS THE CWA SAME TIME PERIOD. GFS
MAINLY DRY...WITH BULK OF POPS TO THE WEST ASSOCIATED WITH
APPROACHING COLD FRONT. FOR NOW...BROAD BRUSHED POPS ACROSS CWA
DURING THE PERIOD. IN ADDITION TO ANY PRECIPITATION...WARMER WEATHER
IS EXPECTED TO RETURN AS UPPER RIDGE STRENGTHENS IN RESPONSE TO
TROUGH TO THE WEST. EXPECT TEMPS TO RISE INTO THE UPPER 60S TO LOWER
70S DURING THE PERIOD. IN ADDITION...WINDS ON WEDNESDAY WILL BE ON
THE INCREASE AS THE PRESSURE GRADIENT TIGHTENS OUT AHEAD OF
APPROACHING COLD FRONT...PARTICULARLY ACROSS RIDGE TOPS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
GENERALLY FOLLOWED WPC THINKING WITH THE EXTENDED PORTION OF THE
FORECAST...WITH A LEANING TOWARDS THE EC/CMC PER ENSEMBLE SUPPORT.
UPPER RIDGE AXIS OVER THE FORECAST AREA AT THE OUTSET OF THE PERIOD
WILL QUICKLY PUSH OFF TO THE EAST WITH A POTENT SYSTEM PUSHING OUT
OF THE CENTRAL ROCKIES TOWARDS THE UPPER MIDWEST...AND SFC COLD
FRONT MARCHING EASTWARD ACROSS THE MISS VALLEY. BASED ON THE SLOWER
PROGRESSION OF NWP CONSENSUS...LOOKS LIKE THURSDAY WILL BE WARM WITH
THE BULK OF THE PRECIP HOLDING OFF UNTIL THURSDAY NIGHT AND FRIDAY
MORNING WITH THE COLD FRONT. PRECIP EXITS TO THE EAST FRIDAY
AFTERNOON...BUT SW FLOW ALOFT CONTINUES OVER THE AREA AS UPPER
TROUGH CONTINUES TO DIG ACROSS THE GREAT LAKES AND OHIO RIVER
VALLEY. AS THE TROUGH MOVES OVERHEAD SATURDAY...WILL CONTINUE SLIGHT
CHANCE POPS MAINLY ACROSS THE NORTHERN ZONES AND EASTERN MOUNTAINS.
FLOW TURNS NORTHWEST BEHIND THE TROUGH AXIS ON SUNDAY YET WITH SOME
LLVL MOISTURE TRAPPED...WILL KEEP THE SLIGHT CHANCE POPS IN ROUGHLY
THE SAME LOCATIONS AS SATURDAY. TEMPERATURES WILL BE PROGRESSIVELY
COOLER WITH EACH PASSING DAY THROUGH THE EXTENDED...DROPPING FROM
THE LOWER 70S LOWLANDS ON THURSDAY TO AROUND THE 50 DEGREE MARK BY
SUNDAY FOR THE LOWLANDS.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
FEW TO SCT 4 TO 5 THSD FT CLDS INTO MORNING HRS ALONG AND N OF I64
CORRIDOR. ACROSS THE S...HAVE OVC CONDITIONS SPREADING N THRU SW
VA INTO S WV PREDAWN. THINK MUCH OF THESE REMAIN LOW END
VFR...SAVE FOR SOME MVFR CIGS FOR S MTNS INCLUDING KBKW. HAVE SOME
PREDAWN MVFR RVR VALLEY FG FOR KPKB AND KEKN.
UPR LVL SYS RESPONSIBLE FOR INCREASE IN CLDS WILL PASS S OF AREA
TDY. HOWEVER SCT SHRA EXPECTED FOR SW VA AND SE WV. HAVE VCSH IN
KBKW TAF WITH CHC NOT THAT GREAT ATTM. KEPT MVFR CIGS GOING
THOUGH. TOUGH TO SAY WHETHER OVC REACHES KHTS TO KCRW TDY BUT DID
INSERT BKN LOW END VFR CLDS IN FOR TDY. JUST HAVE SOME CIRRUS SE
OH/N WV FOR TDY.
UPR LVL SYS PASSES E OF AREA THIS AFTN...TAKING SHRA THREAT WITH
IT. HOWEVER ABUNDANT LLVL MOISTURE WILL REMAIN ACROSS SW VA AND S
WV TONIGHT WHICH MAY HOLD IN MVFR CIGS FOR KBKW. OTHERWISE JUST
SOME PASSING CIRRUS SE OH/N WV WHERE SOME LATE LIFR/IFR RVR FG MAY
BE REALIZED.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATIVE SCENARIOS: OVC DECK MAY MAKE IT INTO KHTS/KCRW FOR
TDY...BUT STILL WOULD REMAIN VFR.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 10/28/13
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY H H H H H M M M H H H H
HTS CONSISTENCY H H M M M M M M H H H H
BKW CONSISTENCY H H M H H H H H H H H H
EKN CONSISTENCY M M H H M M M M H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z TUESDAY...
IFR OR WORSE IN RVR VALLEY FG POSSIBLE TUES MORNING ACROSS SE OH/N WV.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/50/30
NEAR TERM...30
SHORT TERM...SL
LONG TERM...ARJ
AVIATION...30
AREA FORECAST DISCUSSION
NWS MEDFORD OR
1052 PM PDT SUN OCT 27 2013
.UPDATE...
A WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR PORTIONS OF LAKE,
KLAMATH, AND MODOC COUNTIES FOR ELEVATIONS ABOVE 4500 FEET FOR
EXPECTED ACCUMULATIONS OF 2 TO 4 INCHES OF SNOW.
&&
.DISCUSSION...
THE CENTER OF THE UPPER LEVEL LOW OVER OUR AREA IS CURRENTLY JUST
A LITTLE EAST OF MOUNT SHASTA AT THE CURRENT TIME, NEAR MEDICINE
LAKE. MOISTURE WRAPPING AROUND THIS LOW AS IT PIVOTS SOUTHWARD
ALONG THE SIERRA CREST IS EXPECTED TO REACH LAKE AND MODOC
COUNTIES WITH A PERIOD OF ENHANCED PRECIPITATION LATE TONIGHT
CONTINUING INTO MONDAY MORNING. PAST SIMILAR SYNOPTIC SITUATIONS
HAVE LED TO SIGNIFICANT SNOWFALL IN THE TRANSITION SEASON IN THE
AREA THAT HAS BEEN HIGHLIGHTED FOR A WINTER WEATHER ADVISORY.
ADDITIONALLY, THE NEW 00Z RUNS OF THE NAM12 AND GFS40 SUPPORT AN
ENHANCED PRECIPITATION BAND IN THIS AREA. THE 02Z 3KM HRRR MODEL
INDICATED EVEN MORE PRECIPITATION THAN THESE MODELS, BUT HAS SINCE
BACKED OFF WITH ITS 03Z RUN CLOSER TO A NAM12/GFS40 CONSENSUS.
GIVEN THAT IT IS EARLY SEASON, HAS BEEN MILD LATELY, AND TOMORROW
WILL BE THE BEGINNING OF THE WORK WEEK FOR MANY, DECIDED AN
ADVISORY IS WARRANTED DUE TO POTENTIAL IMPACT. WITH THIS TYPE OF
SCENARIO A COUPLE OF INCHES OF SNOW COULD FALL IN JUST AN HOUR OR
TWO. LOWER ELEVATION AREAS SUCH AS LAKEVIEW AND ALTURAS WILL LIKELY
SEE SOME SNOW, BUT AMOUNTS SHOULD BE LESS THAN 2 INCHES. BTL
&&
.AVIATION...
BASED ON THE 28/00Z TAF CYCLE.
SKIES SHOULD GRADUALLY CLEAR OVERNIGHT AND THIS WILL INCREASE THE
PROBABILITY OF STRATUS AND FOG IN AREAS THAT RECEIVED RAIN ON
SUNDAY. THINK AT LEAST MVFR CIGS/VIS ARE MOSTLY LIKELY TO REDEVELOP
ALONG THE COAST AND THROUGH THE UMPQUA, BUT KMFR ALSO RECEIVED RAIN,
SO IT IS POSSIBLE IN THE ROGUE VALLEY AS WELL. LITTLE TO NO RAIN
FELL ON THE EAST SIDE OR CALIFORNIA, SO CLEARING SKIES LATER TONIGHT
ARE LESS LIKELY TO RESULT IN PROBLEMS AFFECTING AVIATION. HOWEVER,
THERE WILL BE SOME RAIN/SNOW SHOWERS OVERNIGHT EAST OF THE CASCADES
WHICH CAN REDUCE VISIBILITIES. CLOUDS AND SNOW SHOWERS WILL LIKELY
LINGER IN THE MOUNTAINS THROUGH THE NIGHT RESULTING IN OBSCURATIONS,
ESPECIALLY IN THE CASCADES AND WARNERS. -WRIGHT
&&
MARINE...WITH OFFSHORE HIGH PRESSURE AND LOW PRESSURE INLAND,
MODERATE NORTH WINDS AND SEAS WILL CONTINUE OVER OUR WATERS THROUGH
MONDAY. WINDS AND SEAS WILL LESSEN THROUGH THE WEEK AS HIGH PRESSURE
WEAKENS AND MOVES OVER THE WATERS. HOWEVER, THE FIRST MAJOR STORM IN
SEVERAL WEEKS IS POSSIBLE NEXT WEEKEND. CONFIDENCE IS INCREASING
THAT DEEPENING LOW PRESSURE WILL MOVE INSIDE 130W NEXT WEEKEND, AND
SUCH A SCENARIO MAY PRODUCE STRONG SOUTH WINDS OVER THE OREGON
WATERS IN ADDITION TO VERY HIGH SEAS. MUCH CAN CHANGE IN A WEEK`S
TIME, BUT MARINERS WITH INTERESTS OVER THE OREGON WATERS NEXT
WEEKEND SHOULD PAY SPECIAL ATTENTION AS FORECASTS ARE UPDATED THIS
WEEK. -WRIGHT
&&
.PREV DISCUSSION... /ISSUED 932 PM PDT SUN OCT 27 2013/
UPDATE...
AN UPDATE WAS ISSUED TO THE MARINE FORECAST TO LOWER WINDS ALONG
AND NEAR THE COAST, BUT TO INCREASE WAVE HEIGHTS.
DISCUSSION...
A FRESH SWELL ASSOCIATED WITH TODAY`S LOW HAS CAUSED WAVE HEIGHTS
TO BE AS MUCH AS 3 FEET HIGH THAN MODEL EXPECTATIONS THIS EVENING.
AN UPDATE TO THE MARINE PORTION OF THE FORECAST HAS, THEREFORE,
BEEN SENT TO ADDRESS THIS.
TODAY`S COLD FRONT CAME THROUGH WITH PRECIPITATION COVERAGE A BIT
ON THE HIGHER SIDE OF THE FORECAST AND THERE WERE EVEN A HANDFUL
OF LIGHTNING STRIKES AS COLDER AIR INFILTRATED THE EAST SIDE THIS
AFTERNOON. ROAD CAMERAS THIS EVENING INDICATED A TRACE TO POSSIBLY
2 INCHES OF SNOW ABOVE ABOUT 5000 FEET, GREATEST AT WILLAMETTE
PASS.
CURRENT RADAR AND ROAD CAMERAS INDICATE SHOWERS CONTINUING ACROSS
THE AREA, CENTERED ON THE CASCADES AND SISKIYOUS.
WE WILL NEED TO KEEP AN EYE ON WRAP-AROUND SNOWFALL ON THE EAST
SIDE OVERNIGHT INTO MONDAY MORNING. THE HRRR-3KM MODEL AND THE
GFS40 INDICATE 1-3 INCHES OF SNOW POSSIBLE ACROSS SOUTHERN LAKE
AND MODOC COUNTIES INTO THE MEDICINE LAKE TO MOUNT SHASTA
HIGHLANDS. BTL
PREV DISCUSSION... /ISSUED 235 PM PDT SUN OCT 27 2013/
SHORT TERM...A FRONT IS DROPPING DOWN FROM THE NORTH AND MOVING
ACROSS THE AREA THIS AFTERNOON. BEHIND THIS FRONT EXPECT NUMEROUS
SHOWERS AS THE UPPER LOW DROPS DOWN OVER THE AREA THIS EVENING.
SHOWERS HAVE MOVED INTO NORTHERN PORTIONS OF THE AREA THIS
AFTERNOON AND WILL SPREAD OVER MOST THE AREA BY THIS EVENING. THIS
SYSTEM IS ALSO BRINGING VERY BREEZY AND GUSTY WINDS TO THE AREA,
ESPECIALLY OVER THE MOUNTAINS AND EAST OF THE CASCADES. STRONGEST
GUSTS ARE EXPECTED WITH THE FRONTAL PASSAGE THIS AFTERNOON.
HOWEVER BREEZY WINDS WILL CONTINUE FOR THE MOUNTAINS AND EAST SIDE
THIS EVENING INTO MONDAY.
AS THE LOW MOVES DOWN INTO THE AREA THIS EVENING AND GRADUALLY
SOUTHWARD TONIGHT INTO MONDAY MORNING, EXPECT SCATTERED TO
WIDESPREAD SHOWERS WITH LOWERING SNOW LEVELS. SNOW LEVELS WILL
LOWER TO AROUND 5000 FEET THIS EVENING AND THEN DOWN TO 4000 FEET
TONIGHT INTO MONDAY MORNING. MOST AREAS WILL SEE A CHANCE FOR
SHOWER ACTIVITY THIS EVENING. THEN OVERNIGHT INTO MONDAY EXPECT
THE BEST SHOWER ACTIVITY TO BE FROM THE CASCADES EAST. HOWEVER AS
MOISTURE WRAPS AROUND THE LOW IN NORTH TO NORTHEAST FLOW, AREAS
WEST OF THE CASCADES MAY CONTINUE TO SEE SHOWERS TONIGHT
ESPECIALLY WHERE THIS IS FAVORABLE UPSLOPE FLOW, SUCH AS IN THE
SISKIYOU MOUNTAINS AND NEAR MOUNT SHASTA, WEED AND TENNANT. EXPECT SOME
LIGHT SNOW ACCUMULATIONS AS SNOW LEVELS LOWER TO 4000 FEET TONIGHT
AND MONDAY MORNING, MAINLY IN THE CASCADES AND OVER HIGHER TERRAIN
ON THE EAST SIDE. EASTERN MOUNTAINS, SUCH AS THE WARNER MOUNTAINS
AND HART MOUNTAIN, MAY SEE UP TO A FEW INCHES OF SNOW POSSIBLE
TONIGHT INTO MONDAY MORNING. PASSES IN THE SOUTHERN OREGON
CASCADES MAY SEE AROUND ONE TO TWO INCHES OF SNOW ACCUMULATION
TONIGHT. ALSO SISKIYOU SUMMIT MAY SEE SOME BRIEF LIGHT SNOW
ACCUMULATIONS TONIGHT.
DURING THE AFTERNOON AND EVENING MONDAY, WRAP AROUND MOISTURE WILL
CONTINUE TO BRING SHOWERS, MAINLY EAST OF THE CASCADES WITH THE
BEST CHANCE FOR SHOWERS OVER LAKE AND MODOC COUNTIES. THEN AS THE
LOW MOVES EAST EXPECT SHOWERS TO TAPER OFF MONDAY NIGHT INTO
TUESDAY.
A COLD AIR MASS WILL BE IN PLACE OVER THE AREA MONDAY INTO TUESDAY.
THIS WILL BRING COOL TEMPERATURES DURING THE DAY MONDAY. ALSO
EXPECT COLD TEMPERATURES OVERNIGHT MONDAY NIGHT INTO TUESDAY. EAST
OF THE CASCADES TEMPERATURES MAY LOWER INTO THE TEENS TO LOW 20S.
COLD TEMPERATURES ARE ALSO EXPECTED FOR SOME WEST SIDE VALLEYS,
INCLUDING THE ROGUE, APPLEGATE AND ILLINOIS VALLEYS WHERE LOW
TEMPERATURES ARE EXPECTED TO DROP TO NEAR OR BELOW FREEZING BY
EARLY TUESDAY MORNING. A FREEZE WATCH HAS BEEN ISSUED FOR THESE
LOCATIONS. IN THE UMPQUA VALLEY AS WELL AS IN THE COQUILLE AND
ALONG PORTIONS OF THE COOS COAST, TEMPERATURES MAY LOWER INTO THE
LOW TO MID 30S MONDAY NIGHT AND TUESDAY MORNING.
BEHIND THIS LOW, AN OFFSHORE RIDGE NUDGES INTO THE AREA TUESDAY
INTO TUESDAY NIGHT AND A VERY WEAK PACIFIC FRONT MOVING OVER THE
RIDGE MOVES TOWARDS THE COAST WEDNESDAY. THIS FRONT MAY BRING A
SLIGHT CHANCE FOR RAIN SHOWERS TO NORTHWESTERN PORTIONS OF THE
CWA, MAINLY COOS AND DOUGLAS COUNTY BY WEDNESDAY EVENING.
OTHERWISE EXPECT ANOTHER ROUND OF COLD VALLEY TEMPERATURES
WEDNESDAY MORNING FOLLOWED BY TEMPERATURES WARMING INTO THE 50S
EAST OF THE CASCADES AND INTO THE UPPER 50S TO MID 60S WEST OF THE
CASCADES.
LONG TERM...THURSDAY THROUGH SUNDAY NIGHT...
THERE IS MUCH MORE CONFIDENCE TODAY IN THE EXTENDED PERIOD...AS
MODELS HAVE COME INTO GOOD AGREEMENT DURING THE MOST RECENT RUNS.
HAVE BASED THE FORECAST ON A GENERAL BLEND OF THE GFS AND ECMWF
SOLUTIONS...BUT WITH A BIAS TOWARDS THE GFS...WHICH HAS BEEN RATHER
CONSISTENT IN PRODUCING WHAT WILL BE A MORE PROGRESSIVE PATTERN.
THURSDAY MORNING...A RIDGE WILL EXTEND NORTHEASTWARD INTO NORTHERN
CALIFORNIA AND SOUTHERN OREGON FROM THE EASTERN PACIFIC. THE RIDGE
WILL GRADUALLY SLIDE EAST NORTH OF A CUT OFF LOW LOCATED JUST OFF
THE COAST OF BAJA CALIFORNIA. MEANWHILE...A TROUGH WITHIN THE
WESTERLIES WILL PUSH EAST ACROSS THE PACIFIC...AND THE TWO WILL
BEGIN TO COME INTO PHASE AS THE TROUGH APPROACHES THE COAST FRIDAY
NIGHT AND SATURDAY MORNING. AT THE SURFACE...THE MODELS PRODUCE A
DEEPENING LOW AT THIS TIME...THE CENTER OF WHICH THEN MOVES ONSHORE
MIDDAY SATURDAY SOMEWHERE ALONG THE NORTHERN OREGON COAST. ALL IN
ALL...THE EVENT WILL MAKE FOR AN INTERESTING WEEKEND FOR THE
FORECAST AREA. THE DETAILS WILL BE DIFFICULT TO NAIL DOWN AT THIS
RANGE...BUT THE AREAS ALONG THE COAST...HIGHER ELEVATIONS AND
RIDGE LINES...AS WELL AS THE EAST SIDE...SHOULD EXPECT VERY GUSTY
WINDS SATURDAY AND SUNDAY. PRECIPITATION SHOULD BE WIDESPREAD...WITH
HEAVIER AMOUNTS LIKELY ALONG THE COAST RANGES AND THE CASCADES. SNOW
LEVELS COULD DROP TO BELOW 5000 FEET BY SUNDAY AS WELL. MORE DETAILS
WILL BECOME APPARENT AS THE EVENT APPROACHES THE SHORT TERM.
THE SYSTEM EXITS THE AREA SUNDAY NIGHT...BUT THE NEXT TROUGH WILL
NOT BE FAR BEHIND. THE GFS AND EC DIFFER IN TIMING BY ABOUT 12
HOURS...BUT BOTH DO MOVE THE SYSTEM ONSHORE SOMETIME TUESDAY. TO
ACCOUNT FOR THIS UNCERTAINTY...HAVE KEPT SLIGHT TO CHANCE POPS ALONG
THE WESTS SIDE AND THE CASCADES FOR THE REMAINDER OF THE FORECAST
TERM.
TEMPERATURES DURING THE EXTENDED PERIOD WILL BE COOLER THAN
RECENTLY...RETURNING TO MUCH MORE SEASONAL VALUES AND HOVERING THERE
FOR THE DURATION OF THE TERM. /BPN
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY FROM 2 AM TO 10 AM PDT MONDAY ABOVE 4500
FEET FOR FOR ORZ030-031.
FREEZE WATCH FROM LATE MONDAY NIGHT THROUGH TUESDAY MORNING FOR
ORZ024-026.
CA...WINTER WEATHER ADVISORY FROM 2 AM TO 10 AM PDT MONDAY ABOVE 4500
FEET FOR FOR CAZ085.
PACIFIC COASTAL WATERS...
- SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT MONDAY
FOR PZZ350-356.
- SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT MONDAY FOR
PZZ370.
- SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT TUESDAY
FOR PZZ370.
- SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT TUESDAY FOR PZZ376.
- HAZARDOUS SEAS WARNING UNTIL 5 AM PDT MONDAY FOR PZZ376.
$$
BTL/TRW/CC/BPN
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
518 AM EDT MON OCT 28 2013
.SYNOPSIS...
A COLD FRONT EXTENDED ACROSS THE GREAT LAKES TO A LOW IN
THE CENTRAL ROCKIES THIS MORNING...WHILE WEAK HIGH PRESSURE WAS OVER
THE SOUTHEAST UNITED STATES. THE FRONT WILL MOVE SOUTHEAST AND
DISSIPATE TODAY AND TONIGHT. TUESDAY AND WEDNESDAY THE LOW WILL MOVE
FROM THE CENTRAL PLAINS INTO THE WESTERN GREAT LAKES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 515 AM EDT MONDAY...
A WEAK STATIONARY BOUNDARY AT THE SURFACE WAS OVER THE TENNESSEE
VALLEY AND WAS THE LEADING EDGE OF WARMER AIR AND HIGHER DEW POINTS.
WATER VAPOR LOOP SHOWED AN UPPER LOW IN NORTHEAST MISSISSIPPI. THIS
LOW WILL MOVE EAST INTO THE CAROLINAS BY LATE TONIGHT.
AS SURFACE DEW POINTS RISE INTO THE 40S AND 50S AND THE AIR MASS
SATURATES...THE PROBABILITY OF PRECIPITATION GOES UP BUT AMOUNTS WILL
REMAIN LIGHT. HAVE INCREASED PROBABILITY OF PRECIPITATION IN THE
SOUTHWEST COUNTIES OF THE FORECAST AREA WHERE MOST OF THE GUIDANCE
IS SHOWING SOME RAIN FOR TODAY BUT HAVE DELAYED THE START TIME.
LOCAL WRF AND RAP GUIDANCE HAVE THE BEST CHANCE OF RAIN MOVING INTO
THE COUNTY WARNING AREA AFTER 13Z/9AM.
CLOUDS WILL ADVANCE INTO THE AREA AHEAD OF THE RAIN. SATELLITE
PICTURES SHOWED LEADING EDGE ALREADY UP TO A BLUEFIELD TO DANVILLE
LINE. WITH CLOUD COVER EXPECTED MUCH OF THE DAY IN THIS SOUTHWEST
PART OF THE FORECAST AREA...HAVE GONE A COUPLE OF DEGREES BELOW
GUIDANCE FOR MAXIMUM TEMPERATURES. USED A BLEND OF BIAS CORRECTED
MAV/MET GUIDANCE FOR OVERNIGHT LOWS.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
AS OF 330 AM EDT MONDAY...
UPPER LEVEL RIDGING ACROSS THE EASTERN HALF OF THE NATION WILL
RESULT IN UNSEASONABLY WARM TEMPERATURES FOR THE MIDDLE OF THE
WORKWEEK. WILL START TUESDAY OFF WITH A WEAK COLD FRONT SINKING
SOUTHWARD ACROSS OUR AREA...WHILE HIGH PRESSURE BUILDS IN BEHIND...
HUGGING THE EASTERN FACE OF THE APPALACHIANS. NORTHEASTERLY WINDS
AROUND THE HIGH WILL CARRY COOLER AIR FROM THE ATLANTIC...AND
THEREFORE HAVE UNDERCUT MODEL GUIDANCE A COUPLE OF DEGREES FOR
AFTERNOON HIGHS. ALSO KEPT A SLIGHT CHANCE OF SHOWERS IN THE
FORECAST FOR THE MORNING AND AFTERNOON AS THE FRONT STALLS JUST
SOUTH OF OUR AREA...BUT BELIEVE THIS ACTIVITY WILL REMAIN ISOLATED
AND MAINLY IN THE FORM OF SPRINKLES WHERE IT DOES OCCUR.
WINDS WILL QUICKLY SHIFT SOUTHWESTERLY TUESDAY NIGHT AS HIGH
PRESSURE SLIDES OFFSHORE...AND A DEEP LOW PRESSURE SYSTEM DEVELOPS
OVER THE CENTRAL PLAINS. THE STALLED FRONT WILL LIFT BACK TO THE
NORTH AS A WARM FRONT WEST OF THE APPALACHIANS...BUT WILL BE SLOWER
TO LIFT NEAR OUR AREA...AND WILL THEREFORE PROVIDE THE FOCUS OF MORE
SPOTTY SHOWER ACTIVITY. BELIEVE THESE SHOWERS WILL OCCUR IN WAVES AS
WEAK UPPER LEVEL DISTURBANCES RIDE ALONG THE FRONT FROM THE WEST...
WITH BETTER RAIN CHANCES FOUND NORTH OF INTERSTATE 81. THE WARM
FRONT WILL FINALLY LIFT NORTH OF OUR AREA WEDNESDAY EVENING...
BRINGING A LULL IN THE SHOWER ACTIVITY AS THE LOW PRESSURE SYSTEM
APPROACHES THE GREAT LAKES...DRAGGING A STRONG COLD FRONT ACROSS THE
PLAINS.
SHOWER ACTIVITY WILL INCREASE ON THURSDAY AFTERNOON AND EVENING AS
THE COLD FRONT MOVES EAST OF THE MISSISSIPPI RIVER...BUT BELIEVE THE
HEAVIEST AND MOST WIDESPREAD RAIN WILL OCCUR AFTER MIDNIGHT EARLY
FRIDAY MORNING AS THE SUPPORTING UPPER LEVEL TROUGH MOVES ACROSS THE
AREA. MOST MODELS ARE IN GOOD AGREEMENT WITH TIMING OF THE FRONT...
AND THERE HAS BEEN GOOD MODEL RUN TO RUN CONSISTENCY OVER THE PAST
DAY...SO FEEL COMFORTABLE GOING WITH HIGH RAIN CHANCES FOR EARLY
FRIDAY. WHILE CAPE IS MINIMAL...MODELS AGREE THAT THE 50+ KT LOW
LEVEL JET WILL SUPPORT HIGH SHEAR AND HELICITY VALUES ACROSS OUR
AREA...MEANING THAT WHILE WE MAY NOT OBSERVE MUCH LIGHTNING IN THE
CONVECTION...THE HEAVIER SHOWERS MAY PULL SOME OF THE STRONGER WINDS
ALOFT DOWN TO THE SURFACE...RESULTING IN GUSTY AND LOCALLY DAMAGING
WINDS. THE HIGH SHEAR AND HELICITY ALSO MEANS WE CANNOT RULE OUT AN
ISOLATED SPIN UP TORNADO.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 400 AM EDT MONDAY...
THE COLD FRONT WILL SLIDE EAST ACROSS THE AREA FRIDAY AFTERNOON AND
REACH THE ATLANTIC COAST FRIDAY NIGHT INTO SATURDAY MORNING. LEANED
ISC GRIDS TOWARDS THE SLOWER ECMWF WITH COLD FRONT OVER THE QUICKER
GFS SOLUTION. IN THE WAKE OF THE COLD FRONT...HIGH PRESSURE WILL
BUILD EAST ACROSS OUR REGION SATURDAY. BY SATURDAY NIGHT THE
COMBINATION OF NORTHWEST FLOW AND A SHORTWAVE WILL CREATE UPSLOPE
RAIN AND SNOW SHOWERS ACROSS THE FAVORED UPSLOPE REGION IN THE WEST.
HIGH PRESSURE BUILDS EAST INTO THE REGION SUNDAY...ENDING ANY
UPSLOPE PRECIPITATION IN THE WEST. COOLING TREND EXPECTED IN THE
TEMPERATURES FOR THE WEEKEND AS UPPER TROUGH SLIDE ACROSS EAST COAST.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
AS OF 135 AM EDT MONDAY...
NORTHEAST EDGE OF CLOUD SHIELD ASSOCIATED WITH AN UPPER LOW OVER
NORTHEAST MISSISSIPPI WAS ADVANCING EAST INTO VIRGINIA AND THE
CAROLINAS. CEILINGS HAD DROPPED TO MVFR IN EXTREME SOUTHWEST
VIRGINIA AND EASTERN TENNESSEE.
MODELS TRACK THE UPPER LOW EAST INTO THE CAROLINAS. GUIDANCE KEPT
CEILINGS VFR AT KBLF/KBCB/KROA AND KDAN BUT THESE SITES MAY
POSSIBLY HAVE MVFR CEILINGS BEFORE 18Z/2PM. CONFIDENCE IS
MODERATE. FARTHER NORTH KLWB AND KLYH WILL REMAIN VFR TODAY.
THE UPPER LOW WILL BE EAST OF THE FORECAST AREA TONIGHT. CLOUDS
WILL GRADUALLY CLEAR BY TUESDAY MORNING. THERE MAY BE FOG AT KLWB
OVERNIGHT...BUT HELD OUT OF THE TAF FOR NOW.
LIGHT SHOWERS ARE ALSO POSSIBLE...ESPECIALLY AT KDAN AS THE LOW
PASSES THE AREA...BUT NO VISIBILITY RESTRICTION IS EXPECTED. THE
AIR MASS IS SLOWLY SATURATING AS THE LOW APPROACHES BUT THE MODELS
HOLD BEST PROBABILITY OF PRECIPITATION ACROSS SOUTHERN VIRGINIA
AND TO THE SOUTH.
MAINLY VFR CONDITIONS ARE EXPECTED TUESDAY THROUGH THURSDAY IN
ADVANCE OF AN APPROACHING COLD FRONT. LOW LEVEL SOUTHERLY WINDS
WILL BE STEADILY INCREASING DURING THIS PERIOD.
MODEL GUIDANCE VARIES AS TO THE TIMING OF THE PASSAGE OF A COLD
FRONT. CURRENTLY LOOKING AT SOMETIME ON THURSDAY NIGHT TO FRIDAY.
THE PASSAGE OF THE FRONT WILL BRING SUB-VFR CONDITIONS ALONG AND
AHEAD OF THE BOUNDARY WITH SHOWERS AND GUSTY WIND.
IN THE WAKE OF THE COLD FRONT...LOOK FOR INCREASING NORTHWEST FLOW
BEHIND THE SURFACE SYSTEM. THIS SCENARIO WILL LIKELY PLACE
UPSLOPE RAIN/SNOW SHOWERS ACROSS THE PREFERRED UPSLOPE REGIONS OF
SOUTHEAST WEST VIRGINIA SATURDAY INTO SUNDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...NF
LONG TERM...KK
AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
453 AM EDT MON OCT 28 2013
.SYNOPSIS...
A COLD FRONT EXTENDED ACROSS THE GREAT LAKES TO A LOW IN
THE CENTRAL ROCKIES THIS MORNING...WHILE WEAK HIGH PRESSURE WAS OVER
THE SOUTHEAST UNITED STATES. THE FRONT WILL MOVE SOUTHEAST AND
DISSIPATE TODAY AND TONIGHT. TUESDAY AND WEDNESDAY THE LOW WILL MOVE
FROM THE CENTRAL PLAINS INTO THE WESTERN GREAT LAKES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 515 AM EDT MONDAY...
A WEAK STATIONARY BOUNDARY AT THE SURFACE WAS OVER THE TENNESSEE
VALLEY AND WAS THE LEADING EDGE OF WARMER AIR AND HIGHER DEW POINTS.
WATER VAPOR LOOP SHOWED AN UPPER LOW IN NORTHEAST MISSISSIPPI. THIS
LOW WILL MOVE EAST INTO THE CAROLINAS BY LATE TONIGHT.
AS SURFACE DEW POINTS RISE INTO THE 40S AND 50S AND THE AIR MASS
SATURATES...THE PROBABILITY OF PRECIPITATION GOES UP BUT AMOUNTS WILL
REMAIN LIGHT. HAVE INCREASED PROBABILITY OF PRECIPITATION IN THE
SOUTHWEST COUNTIES OF THE FORECAST AREA WHERE MOST OF THE GUIDANCE
IS SHOWING SOME RAIN FOR TODAY BUT HAVE DELAYED THE START TIME.
LOCAL WRF AND RAP GUIDANCE HAVE THE BEST CHANCE OF RAIN MOVING INTO
THE COUNTY WARNING AREA AFTER 13Z/9AM.
CLOUDS WILL ADVANCE INTO THE AREA AHEAD OF THE RAIN. SATELLITE
PICTURES SHOWED LEADING EDGE ALREADY UP TO A BLUEFIELD TO DANVILLE
LINE. WITH CLOUD COVER EXPECTED MUCH OF THE DAY IN THIS SOUTHWEST
PART OF THE FORECAST AREA...HAVE GONE A COUPLE OF DEGREES BELOW
GUIDANCE FOR MAXIMUM TEMPERATURES. USED A BLEND OF BIAS CORRECTED
MAV/MET GUIDANCE FOR OVERNIGHT LOWS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM EDT MONDAY...
A WARMING TREND WILL CONTINUE THROUGH THE FIRST HALF OF THE WORKWEEK
AS RELATIVELY ZONAL FLOW EAST OF THE MISSISSIPPI RIVER GIVES WAY TO
WEAK RIDGING IN THE UPPER LEVELS OF THE ATMOSPHERE...WHILE A DEEP
UPPER LOW OVER THE INTERMOUNTAIN WEST MONDAY AND TUESDAY PUSHES
ACROSS THE PLAINS ON WEDNESDAY.
ON MONDAY...SOUTHWESTERLY WINDFLOW AROUND A BROAD DOME OF HIGH
PRESSURE CENTERED OFF THE MID ATLANTIC COAST WILL MAKE FOR WARMER
AFTERNOON TEMPERATURES...RANGING FROM UPPER 50S/LOW 60S ACROSS THE
MOUNTAINS...TO UPPER 60S EAST OF THE BLUE RIDGE. CLOUD COVER WILL
INCREASE DURING THE MORNING AND AFTERNOON AS A WEAK UPPER
DISTURBANCE PASSES ACROSS TENNESSEE TOWARD OUR AREA...AND MAY SEE A
FEW SHOWERS ACROSS THE MOUNTAINS DURING THE AFTERNOON AND
EVENING...WITH SPRINKLES FURTHER EAST MONDAY NIGHT AS A WEAK COLD
FRONT ENTERS FROM THE NORTH.
HIGH PRESSURE BEHIND THE COLD FRONT WILL BUILD FROM THE GREAT LAKES
SOUTHWARD ALONG THE EASTERN FACE OF THE APPALACHIANS ON TUESDAY...
RESULTING IN A EAST TO NORTHEASTERLY WINDS THROUGH MUCH OF THE DAY.
WENT WITH INCREASED CLOUD COVER AND AFTERNOON TEMPERATURES A FEW
DEGREES BELOW MODEL GUIDANCE FOR TUESDAY AFTERNOON DUE TO THE COOLER
FLOW OFF OF THE ATLANTIC. WILL ALSO KEEP A SLIGHT CHANCE OF SHOWERS
IN THE FORECAST THROUGH THE DAY AS THE COLD FRONT STALL JUST SOUTH
OF OUR AREA...WHILE A DEEP LOW PRESSURE SYSTEM DEVELOPS OVER THE
CENTRAL PLAINS.
SPOTTY SHOWER ACTIVITY WILL CONTINUE INTO WEDNESDAY AS THE FRONT
WEST OF THE APPALACHIANS BEGINS TO LIFT BACK TO THE NORTH AS A WARM
FRONT...WHILE MINOR UPPER LEVEL DISTURBANCES RIDE ALONG THIS
BOUNDARY TO PASS ACROSS OUR AREA. WINDS WILL BECOME INCREASINGLY
SOUTHERLY DURING THE MORNING AS HIGH PRESSURE MOVES OFFSHORE...WHILE
THE LOW PRESSURE SYSTEM TO OUR WEST MAKES A PUSH FOR THE GREAT
LAKES.
MODELS DIFFER ON HOW FAR NORTH THE WARM FRONT PROGRESSES ON
WEDNESDAY...WITH THE GFS MODEL LIFTING THE FRONT NEAR THE SOUTHERN
GREAT LAKES BY EVENING... WHILE THE ECMWF AND CANADIAN MODELS KEEP
THE FRONT ANCHORED ACROSS THE NORTH CAROLINA MOUNTAINS. FOR
NOW...WILL FAVOR MORE TOWARDS THE ECMWF/CANADIAN SOLUTION...WHICH
WILL KEEP A CHANCE OF SHOWERS FOR OUR AREA THROUGH WEDNESDAY
NIGHT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 PM EDT SUNDAY...
LOW PRESSURE OVER THE GREAT LAKES WILL DRAG A STRONG COLD FRONT
EASTWARD THURSDAY. TIMING OF THIS FRONT AND ITS MOISTURE REMAINS A
FORECAST CHALLENGE IN THE MEDIUM RANGE. LEANING TOWARDS A SLOWER
ARRIVAL OF THIS SYSTEM CLOSER TO ECMWF CONSIDERING SUCH A BLOCKY
FLOW PATTERN OUT WEST. GFS/ECMWF MODEL BIAS THIS TIME OF YEAR IS TOO
FAST WITH EASTWARD PROGRESSION OF FRONTS.
THE COLD FRONT WILL APPROACH OUR AREA ON THURSDAY AS ASSOCIATED WARM
FRONT LIFTS NORTHEAST. BY THURSDAY NIGHT...THE WARM FRONT REACHES
THE MASON DIXON LINE AND THE COLD FRONT ENTERS CENTRAL KENTUCKY AND
MIDDLE TENNESSEE. THIS COLD FRONT WILL SLIDE EAST ACROSS THE AREA
FRIDAY AND REACH THE ATLANTIC COAST FRIDAY NIGHT INTO SATURDAY
MORNING. KEPT POPS BELOW LIKELY BECAUSE OF UNCERTAINTY OF TIMING OF
THE COLD FRONT. IN THE WAKE OF THE COLD FRONT...HIGH PRESSURE WILL
BUILD EAST ACROSS OUR REGION SATURDAY. WILL HAVE TO WATCH FOR
SHORTWAVES OR CLIPPERS DROPPING SOUTH IN THE NORTH TO NORTHWEST FLOW
DURING THE WEEKEND.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
AS OF 135 AM EDT MONDAY...
NORTHEAST EDGE OF CLOUD SHIELD ASSOCIATED WITH AN UPPER LOW OVER
NORTHEAST MISSISSIPPI WAS ADVANCING EAST INTO VIRGINIA AND THE
CAROLINAS. CEILINGS HAD DROPPED TO MVFR IN EXTREME SOUTHWEST
VIRGINIA AND EASTERN TENNESSEE.
MODELS TRACK THE UPPER LOW EAST INTO THE CAROLINAS. GUIDANCE KEPT
CEILINGS VFR AT KBLF/KBCB/KROA AND KDAN BUT THESE SITES MAY
POSSIBLY HAVE MVFR CEILINGS BEFORE 18Z/2PM. CONFIDENCE IS
MODERATE. FARTHER NORTH KLWB AND KLYH WILL REMAIN VFR TODAY.
THE UPPER LOW WILL BE EAST OF THE FORECAST AREA TONIGHT. CLOUDS
WILL GRADUALLY CLEAR BY TUESDAY MORNING. THERE MAY BE FOG AT KLWB
OVERNIGHT...BUT HELD OUT OF THE TAF FOR NOW.
LIGHT SHOWERS ARE ALSO POSSIBLE...ESPECIALLY AT KDAN AS THE LOW
PASSES THE AREA...BUT NO VISIBILITY RESTRICTION IS EXPECTED. THE
AIR MASS IS SLOWLY SATURATING AS THE LOW APPROACHES BUT THE MODELS
HOLD BEST PROBABILITY OF PRECIPITATION ACROSS SOUTHERN VIRGINIA
AND TO THE SOUTH.
MAINLY VFR CONDITIONS ARE EXPECTED TUESDAY THROUGH THURSDAY IN
ADVANCE OF AN APPROACHING COLD FRONT. LOW LEVEL SOUTHERLY WINDS
WILL BE STEADILY INCREASING DURING THIS PERIOD.
MODEL GUIDANCE VARIES AS TO THE TIMING OF THE PASSAGE OF A COLD
FRONT. CURRENTLY LOOKING AT SOMETIME ON THURSDAY NIGHT TO FRIDAY.
THE PASSAGE OF THE FRONT WILL BRING SUB-VFR CONDITIONS ALONG AND
AHEAD OF THE BOUNDARY WITH SHOWERS AND GUSTY WIND.
IN THE WAKE OF THE COLD FRONT...LOOK FOR INCREASING NORTHWEST FLOW
BEHIND THE SURFACE SYSTEM. THIS SCENARIO WILL LIKELY PLACE
UPSLOPE RAIN/SNOW SHOWERS ACROSS THE PREFERRED UPSLOPE REGIONS OF
SOUTHEAST WEST VIRGINIA SATURDAY INTO SUNDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...PW
LONG TERM...KK
AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
451 AM EDT MON OCT 28 2013
.SYNOPSIS...
A COLD FRONT EXTENDED ACROSS THE GREAT LAKES TO A LOW IN
THE CENTRAL ROCKIES THIS MORNING...WHILE WEAK HIGH PRESSURE WAS OVER
THE SOUTHEAST UNITED STATES. THE FRONT WILL MOVE SOUTHEAST AND
DISSIPATE TODAY AND TONIGHT. TUESDAY AND WEDNESDAY THE LOW WILL MOVE
FROM THE CENTRAL PLAINS INTO THE WESTERN GREAT LAKES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 515 AM EDT MONDAY...
A WEAK STATIONARY BOUNDARY AT THE SURFACE WAS OVER THE TENNESSEE
VALLEY AND WAS THE LEADING EDGE OF WARMER AIR AND HIGHER DEW POINTS.
WATER VAPOR LOOP SHOWED AN UPPER LOW IN NORTHEAST MISSISSIPPI. THIS
LOW WILL MOVE EAST INTO THE CAROLINAS BY LATE TONIGHT.
AS SURFACE DEW POINTS RISE INTO THE 40S AND 50S AND THE AIR MASS
SATURATES...THE PROBABILITY OF PRECIPITATION GOES UP BUT AMOUNTS WILL
REMAIN LIGHT. HAVE INCREASED PROBABILITY OF PRECIPITATION IN THE
SOUTHWEST COUNTIES OF THE FORECAST AREA WHERE MOST OF THE GUIDANCE
IS SHOWING SOME RAIN FOR TODAY BUT HAVE DELAYED THE START TIME.
LOCAL WRF AND RAP GUIDANCE HAVE THE BEST CHANCE OF RAIN MOVING INTO
THE COUNTY WARNING AREA AFTER 13Z/9AM.
CLOUDS WILL ADVANCE INTO THE AREA AHEAD OF THE RAIN. SATELLITE
PICTURES SHOWED LEADING EDGE ALREADY UP TO A BLUEFIELD TO DANVILLE
LINE. WITH CLOUD COVER EXPECTED MUCH OF THE DAY IN THIS SOUTHWEST
PART OF THE FORECAST AREA...HAVE GONE A COUPLE OF DEGREES BELOW
GUIDANCE FOR MAXIMUM TEMPERATURES. USED A BLEND OF BIAS CORRECTED
MAV/MET GUIDANCE FOR OVERNIGHT LOWS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM EDT MONDAY...
A WARMING TREND WILL CONTINUE THROUGH THE FIRST HALF OF THE WORKWEEK
AS RELATIVELY ZONAL FLOW EAST OF THE MISSISSIPPI RIVER GIVES WAY TO
WEAK RIDGING IN THE UPPER LEVELS OF THE ATMOSPHERE...WHILE A DEEP
UPPER LOW OVER THE INTERMOUNTAIN WEST MONDAY AND TUESDAY PUSHES
ACROSS THE PLAINS ON WEDNESDAY.
ON MONDAY...SOUTHWESTERLY WINDFLOW AROUND A BROAD DOME OF HIGH
PRESSURE CENTERED OFF THE MID ATLANTIC COAST WILL MAKE FOR WARMER
AFTERNOON TEMPERATURES...RANGING FROM UPPER 50S/LOW 60S ACROSS THE
MOUNTAINS...TO UPPER 60S EAST OF THE BLUE RIDGE. CLOUD COVER WILL
INCREASE DURING THE MORNING AND AFTERNOON AS A WEAK UPPER
DISTURBANCE PASSES ACROSS TENNESSEE TOWARD OUR AREA...AND MAY SEE A
FEW SHOWERS ACROSS THE MOUNTAINS DURING THE AFTERNOON AND
EVENING...WITH SPRINKLES FURTHER EAST MONDAY NIGHT AS A WEAK COLD
FRONT ENTERS FROM THE NORTH.
HIGH PRESSURE BEHIND THE COLD FRONT WILL BUILD FROM THE GREAT LAKES
SOUTHWARD ALONG THE EASTERN FACE OF THE APPALACHIANS ON TUESDAY...
RESULTING IN A EAST TO NORTHEASTERLY WINDS THROUGH MUCH OF THE DAY.
WENT WITH INCREASED CLOUD COVER AND AFTERNOON TEMPERATURES A FEW
DEGREES BELOW MODEL GUIDANCE FOR TUESDAY AFTERNOON DUE TO THE COOLER
FLOW OFF OF THE ATLANTIC. WILL ALSO KEEP A SLIGHT CHANCE OF SHOWERS
IN THE FORECAST THROUGH THE DAY AS THE COLD FRONT STALL JUST SOUTH
OF OUR AREA...WHILE A DEEP LOW PRESSURE SYSTEM DEVELOPS OVER THE
CENTRAL PLAINS.
SPOTTY SHOWER ACTIVITY WILL CONTINUE INTO WEDNESDAY AS THE FRONT
WEST OF THE APPALACHIANS BEGINS TO LIFT BACK TO THE NORTH AS A WARM
FRONT...WHILE MINOR UPPER LEVEL DISTURBANCES RIDE ALONG THIS
BOUNDARY TO PASS ACROSS OUR AREA. WINDS WILL BECOME INCREASINGLY
SOUTHERLY DURING THE MORNING AS HIGH PRESSURE MOVES OFFSHORE...WHILE
THE LOW PRESSURE SYSTEM TO OUR WEST MAKES A PUSH FOR THE GREAT
LAKES.
MODELS DIFFER ON HOW FAR NORTH THE WARM FRONT PROGRESSES ON
WEDNESDAY...WITH THE GFS MODEL LIFTING THE FRONT NEAR THE SOUTHERN
GREAT LAKES BY EVENING... WHILE THE ECMWF AND CANADIAN MODELS KEEP
THE FRONT ANCHORED ACROSS THE NORTH CAROLINA MOUNTAINS. FOR
NOW...WILL FAVOR MORE TOWARDS THE ECMWF/CANADIAN SOLUTION...WHICH
WILL KEEP A CHANCE OF SHOWERS FOR OUR AREA THROUGH WEDNESDAY
NIGHT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 PM EDT SUNDAY...
LOW PRESSURE OVER THE GREAT LAKES WILL DRAG A STRONG COLD FRONT
EASTWARD THURSDAY. TIMING OF THIS FRONT AND ITS MOISTURE REMAINS A
FORECAST CHALLENGE IN THE MEDIUM RANGE. LEANING TOWARDS A SLOWER
ARRIVAL OF THIS SYSTEM CLOSER TO ECMWF CONSIDERING SUCH A BLOCKY
FLOW PATTERN OUT WEST. GFS/ECMWF MODEL BIAS THIS TIME OF YEAR IS TOO
FAST WITH EASTWARD PROGRESSION OF FRONTS.
THE COLD FRONT WILL APPROACH OUR AREA ON THURSDAY AS ASSOCIATED WARM
FRONT LIFTS NORTHEAST. BY THURSDAY NIGHT...THE WARM FRONT REACHES
THE MASON DIXON LINE AND THE COLD FRONT ENTERS CENTRAL KENTUCKY AND
MIDDLE TENNESSEE. THIS COLD FRONT WILL SLIDE EAST ACROSS THE AREA
FRIDAY AND REACH THE ATLANTIC COAST FRIDAY NIGHT INTO SATURDAY
MORNING. KEPT POPS BELOW LIKELY BECAUSE OF UNCERTAINTY OF TIMING OF
THE COLD FRONT. IN THE WAKE OF THE COLD FRONT...HIGH PRESSURE WILL
BUILD EAST ACROSS OUR REGION SATURDAY. WILL HAVE TO WATCH FOR
SHORTWAVES OR CLIPPERS DROPPING SOUTH IN THE NORTH TO NORTHWEST FLOW
DURING THE WEEKEND.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
AS OF 135 AM EDT MONDAY...
NORTHEAST EDGE OF CLOUD SHIELD ASSOCIATED WITH AN UPPER LOW OVER
NORTHEAST MISSISSIPPI WAS ADVANCING EAST INTO VIRGINIA AND THE
CAROLINAS. CEILINGS HAD DROPPED TO MVFR IN EXTREME SOUTHWEST
VIRGINIA AND EASTERN TENNESSEE.
MODELS TRACK THE UPPER LOW EAST INTO THE CAROLINAS. GUIDANCE KEPT
CEILINGS VFR AT KBLF/KBCB/KROA AND KDAN BUT THESE SITES MAY
POSSIBLY HAVE MVFR CEILINGS BEFORE 18Z/2PM. CONFIDENCE IS
MODERATE. FARTHER NORTH KLWB AND KLYH WILL REMAIN VFR TODAY.
THE UPPER LOW WILL BE EAST OF THE FORECAST AREA TONIGHT. CLOUDS
WILL GRADUALLY CLEAR BY TUESDAY MORNING. THERE MAY BE FOG AT KLWB
OVERNIGHT...BUT HELD OUT OF THE TAF FOR NOW.
LIGHT SHOWERS ARE ALSO POSSIBLE...ESPECIALLY AT KDAN AS THE LOW
PASSES THE AREA...BUT NO VISIBILITY RESTRICTION IS EXPECTED. THE
AIR MASS IS SLOWLY SATURATING AS THE LOW APPROACHES BUT THE MODELS
HOLD BEST PROBABILITY OF PRECIPITATION ACROSS SOUTHERN VIRGINIA
AND TO THE SOUTH.
MAINLY VFR CONDITIONS ARE EXPECTED TUESDAY THROUGH THURSDAY IN
ADVANCE OF AN APPROACHING COLD FRONT. LOW LEVEL SOUTHERLY WINDS
WILL BE STEADILY INCREASING DURING THIS PERIOD.
MODEL GUIDANCE VARIES AS TO THE TIMING OF THE PASSAGE OF A COLD
FRONT. CURRENTLY LOOKING AT SOMETIME ON THURSDAY NIGHT TO FRIDAY.
THE PASSAGE OF THE FRONT WILL BRING SUB-VFR CONDITIONS ALONG AND
AHEAD OF THE BOUNDARY WITH SHOWERS AND GUSTY WIND.
IN THE WAKE OF THE COLD FRONT...LOOK FOR INCREASING NORTHWEST FLOW
BEHIND THE SURFACE SYSTEM. THIS SCENARIO WILL LIKELY PLACE
UPSLOPE RAIN/SNOW SHOWERS ACROSS THE PREFERRED UPSLOPE REGIONS OF
SOUTHEAST WEST VIRGINIA SATURDAY INTO SUNDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...PW
LONG TERM...KK
AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
449 AM EDT MON OCT 28 2013
.SYNOPSIS...
A COLD FRONT EXTENDED ACROSS THE GREAT LAKES TO A LOW IN
THE CENTRAL ROCKIES THIS MORNING...WHILE WEAK HIGH PRESSURE WAS OVER
THE SOUTHEAST UNITED STATES. THE FRONT WILL MOVE SOUTHEAST AND
DISSIPATE TODAY AND TONIGHT. TUESDAY AND WEDNESDAY THE LOW WILL MOVE
FROM THE CENTRAL PLAINS INTO THE WESTERN GREAT LAKES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 515 AM EDT MONDAY...
A WEAK STATIONARY BOUNDARY AT THE SURFACE WAS OVER THE TENNESSEE
VALLEY AND WAS THE LEADING EDGE OF WARMER AIR AND HIGHER DEW POINTS.
WATER VAPOR LOOP SHOWED AN UPPER LOW IN NORTHEAST MISSISSIPPI. THIS
LOW WILL MOVE EAST INTO THE CAROLINAS BY LATE TONIGHT.
AS SURFACE DEW POINTS RISE INTO THE 40S AND 50S AND THE AIR MASS
SATURATES...THE PROBABILITY OF PRECIPITATION GOES UP BUT AMOUNTS WILL
REMAIN LIGHT. HAVE INCREASED PROBABILITY OF PRECIPITATION IN THE
SOUTHWEST COUNTIES OF THE FORECAST AREA WHERE MOST OF THE GUIDANCE
IS SHOWING SOME RAIN FOR TODAY BUT HAVE DELAYED THE START TIME.
LOCAL WRF AND RAP GUIDANCE HAVE THE BEST CHANCE OF RAIN MOVING INTO
THE COUNTY WARNING AREA AFTER 13Z/7AM.
CLOUDS WILL ADVANCE INTO THE AREA AHEAD OF THE RAIN. SATELLITE
PICTURES SHOWED LEADING EDGE ALREADY UP TO A BLUEFIELD TO DANVILLE
LINE. WITH CLOUD COVER EXPECTED MUCH OF THE DAY IN THIS SOUTHWEST
PART OF THE FORECAST AREA...HAVE GONE A COUPLE OF DEGREES BELOW
GUIDANCE FOR MAXIMUM TEMPERATURES. USED A BLEND OF BIAS CORRECTED
MAV/MET GUIDANCE FOR OVERNIGHT LOWS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM EDT MONDAY...
A WARMING TREND WILL CONTINUE THROUGH THE FIRST HALF OF THE WORKWEEK
AS RELATIVELY ZONAL FLOW EAST OF THE MISSISSIPPI RIVER GIVES WAY TO
WEAK RIDGING IN THE UPPER LEVELS OF THE ATMOSPHERE...WHILE A DEEP
UPPER LOW OVER THE INTERMOUNTAIN WEST MONDAY AND TUESDAY PUSHES
ACROSS THE PLAINS ON WEDNESDAY.
ON MONDAY...SOUTHWESTERLY WINDFLOW AROUND A BROAD DOME OF HIGH
PRESSURE CENTERED OFF THE MID ATLANTIC COAST WILL MAKE FOR WARMER
AFTERNOON TEMPERATURES...RANGING FROM UPPER 50S/LOW 60S ACROSS THE
MOUNTAINS...TO UPPER 60S EAST OF THE BLUE RIDGE. CLOUD COVER WILL
INCREASE DURING THE MORNING AND AFTERNOON AS A WEAK UPPER
DISTURBANCE PASSES ACROSS TENNESSEE TOWARD OUR AREA...AND MAY SEE A
FEW SHOWERS ACROSS THE MOUNTAINS DURING THE AFTERNOON AND
EVENING...WITH SPRINKLES FURTHER EAST MONDAY NIGHT AS A WEAK COLD
FRONT ENTERS FROM THE NORTH.
HIGH PRESSURE BEHIND THE COLD FRONT WILL BUILD FROM THE GREAT LAKES
SOUTHWARD ALONG THE EASTERN FACE OF THE APPALACHIANS ON TUESDAY...
RESULTING IN A EAST TO NORTHEASTERLY WINDS THROUGH MUCH OF THE DAY.
WENT WITH INCREASED CLOUD COVER AND AFTERNOON TEMPERATURES A FEW
DEGREES BELOW MODEL GUIDANCE FOR TUESDAY AFTERNOON DUE TO THE COOLER
FLOW OFF OF THE ATLANTIC. WILL ALSO KEEP A SLIGHT CHANCE OF SHOWERS
IN THE FORECAST THROUGH THE DAY AS THE COLD FRONT STALL JUST SOUTH
OF OUR AREA...WHILE A DEEP LOW PRESSURE SYSTEM DEVELOPS OVER THE
CENTRAL PLAINS.
SPOTTY SHOWER ACTIVITY WILL CONTINUE INTO WEDNESDAY AS THE FRONT
WEST OF THE APPALACHIANS BEGINS TO LIFT BACK TO THE NORTH AS A WARM
FRONT...WHILE MINOR UPPER LEVEL DISTURBANCES RIDE ALONG THIS
BOUNDARY TO PASS ACROSS OUR AREA. WINDS WILL BECOME INCREASINGLY
SOUTHERLY DURING THE MORNING AS HIGH PRESSURE MOVES OFFSHORE...WHILE
THE LOW PRESSURE SYSTEM TO OUR WEST MAKES A PUSH FOR THE GREAT
LAKES.
MODELS DIFFER ON HOW FAR NORTH THE WARM FRONT PROGRESSES ON
WEDNESDAY...WITH THE GFS MODEL LIFTING THE FRONT NEAR THE SOUTHERN
GREAT LAKES BY EVENING... WHILE THE ECMWF AND CANADIAN MODELS KEEP
THE FRONT ANCHORED ACROSS THE NORTH CAROLINA MOUNTAINS. FOR
NOW...WILL FAVOR MORE TOWARDS THE ECMWF/CANADIAN SOLUTION...WHICH
WILL KEEP A CHANCE OF SHOWERS FOR OUR AREA THROUGH WEDNESDAY
NIGHT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 PM EDT SUNDAY...
LOW PRESSURE OVER THE GREAT LAKES WILL DRAG A STRONG COLD FRONT
EASTWARD THURSDAY. TIMING OF THIS FRONT AND ITS MOISTURE REMAINS A
FORECAST CHALLENGE IN THE MEDIUM RANGE. LEANING TOWARDS A SLOWER
ARRIVAL OF THIS SYSTEM CLOSER TO ECMWF CONSIDERING SUCH A BLOCKY
FLOW PATTERN OUT WEST. GFS/ECMWF MODEL BIAS THIS TIME OF YEAR IS TOO
FAST WITH EASTWARD PROGRESSION OF FRONTS.
THE COLD FRONT WILL APPROACH OUR AREA ON THURSDAY AS ASSOCIATED WARM
FRONT LIFTS NORTHEAST. BY THURSDAY NIGHT...THE WARM FRONT REACHES
THE MASON DIXON LINE AND THE COLD FRONT ENTERS CENTRAL KENTUCKY AND
MIDDLE TENNESSEE. THIS COLD FRONT WILL SLIDE EAST ACROSS THE AREA
FRIDAY AND REACH THE ATLANTIC COAST FRIDAY NIGHT INTO SATURDAY
MORNING. KEPT POPS BELOW LIKELY BECAUSE OF UNCERTAINTY OF TIMING OF
THE COLD FRONT. IN THE WAKE OF THE COLD FRONT...HIGH PRESSURE WILL
BUILD EAST ACROSS OUR REGION SATURDAY. WILL HAVE TO WATCH FOR
SHORTWAVES OR CLIPPERS DROPPING SOUTH IN THE NORTH TO NORTHWEST FLOW
DURING THE WEEKEND.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
AS OF 135 AM EDT MONDAY...
NORTHEAST EDGE OF CLOUD SHIELD ASSOCIATED WITH AN UPPER LOW OVER
NORTHEAST MISSISSIPPI WAS ADVANCING EAST INTO VIRGINIA AND THE
CAROLINAS. CEILINGS HAD DROPPED TO MVFR IN EXTREME SOUTHWEST
VIRGINIA AND EASTERN TENNESSEE.
MODELS TRACK THE UPPER LOW EAST INTO THE CAROLINAS. GUIDANCE KEPT
CEILINGS VFR AT KBLF/KBCB/KROA AND KDAN BUT THESE SITES MAY
POSSIBLY HAVE MVFR CEILINGS BEFORE 18Z/2PM. CONFIDENCE IS
MODERATE. FARTHER NORTH KLWB AND KLYH WILL REMAIN VFR TODAY.
THE UPPER LOW WILL BE EAST OF THE FORECAST AREA TONIGHT. CLOUDS
WILL GRADUALLY CLEAR BY TUESDAY MORNING. THERE MAY BE FOG AT KLWB
OVERNIGHT...BUT HELD OUT OF THE TAF FOR NOW.
LIGHT SHOWERS ARE ALSO POSSIBLE...ESPECIALLY AT KDAN AS THE LOW
PASSES THE AREA...BUT NO VISIBILITY RESTRICTION IS EXPECTED. THE
AIR MASS IS SLOWLY SATURATING AS THE LOW APPROACHES BUT THE MODELS
HOLD BEST PROBABILITY OF PRECIPITATION ACROSS SOUTHERN VIRGINIA
AND TO THE SOUTH.
MAINLY VFR CONDITIONS ARE EXPECTED TUESDAY THROUGH THURSDAY IN
ADVANCE OF AN APPROACHING COLD FRONT. LOW LEVEL SOUTHERLY WINDS
WILL BE STEADILY INCREASING DURING THIS PERIOD.
MODEL GUIDANCE VARIES AS TO THE TIMING OF THE PASSAGE OF A COLD
FRONT. CURRENTLY LOOKING AT SOMETIME ON THURSDAY NIGHT TO FRIDAY.
THE PASSAGE OF THE FRONT WILL BRING SUB-VFR CONDITIONS ALONG AND
AHEAD OF THE BOUNDARY WITH SHOWERS AND GUSTY WIND.
IN THE WAKE OF THE COLD FRONT...LOOK FOR INCREASING NORTHWEST FLOW
BEHIND THE SURFACE SYSTEM. THIS SCENARIO WILL LIKELY PLACE
UPSLOPE RAIN/SNOW SHOWERS ACROSS THE PREFERRED UPSLOPE REGIONS OF
SOUTHEAST WEST VIRGINIA SATURDAY INTO SUNDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...PW
LONG TERM...KK
AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
825 AM EDT MON OCT 28 2013
.SYNOPSIS...
AN UPPER-LEVEL DISTURBANCE WILL MOVE OVER THE FORECAST AREA TODAY.
THIS SYSTEM WILL BRING CONSIDERABLE CLOUDINESS AND SPRINKLES WITH
JUST A SMALL CHANCE OF MEASURABLE RAIN. HIGH PRESSURE WILL BUILD
ACROSS THE REGION TUESDAY AND WEDNESDAY. A FRONTAL SYSTEM WILL
AFFECT THE AREA LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MOISTURE ASSOCIATED WITH THE REMNANTS OF A FRONT AND A MID-LEVEL
SHORTWAVE TROUGH WILL BE IN THE FORECAST AREA TODAY. THE SHORTWAVE
TROUGH WAS WELL DEFINED ON THE WATER VAPOR IMAGERY EARLY THIS
MORNING AND WAS HELPING SUPPORT SHOWERS OVER PART OF THE FORECAST
AREA. THE NAM AND GFS HAVE COME INTO GOOD AGREEMENT WITH LOW
POPS TODAY. MODELS DIFFERED GREATLY ON POPS WITH LOW VALUES AS
LOW AS 10 PERCENT AND HIGH VALUES AROUND 50 PERCENT. DECIDED
ION 20-30 PERCENT NORTH AND 80-90 PERCENT SOUTH. RUC MODEL SHOWS
UPPER TROUGH AFFECTING REGION UNTIL AROUND 21Z WHEN IT MOVES
TO THE EAST. THE SPRINKLES AND PATCHES OF LIGHT RAIN MAY CONTINUE
A GOOD PART OF THE DAY. BASED ON THE H85 WESTERLY FLOW WITH
LIMITED MOISTURE WE BELIEVE SHOWER COVERAGE WILL REMAIN LIMITED
AND MUCH OF THE AREA WILL NOT HAVE MEASURABLE RAIN. THE COOLER
GUIDANCE TEMPERATURES APPEAR BETTER BECAUSE OF CLOUDINESS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
TONIGHT SHOULD BE DRY BEHIND THE MID-LEVEL SHORTWAVE TROUGH WITH
SURFACE RIDGING CONTINUING. THE MODELS MAINTAIN THE DRY PATTERN
THROUGH TUESDAY NIGHT. USED THE GUIDANCE CONSENSUS FOR THE
TEMPERATURE FORECAST.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE GFS AND ECMWF ARE IN GOOD AGREEMENT WEDNESDAY DISPLAYING
RIDGING WITH DRY WEATHER. THE MODELS SHOW THE STRONG UPPER LOW
OVER THE ROCKIES WILL LIFT OUT BY THURSDAY AND WILL EJECT A
VIGOROUS SHORTWAVE TROUGH THROUGH THE CENTRAL CONUS. THIS FEATURE
WILL BEGIN TO PUSH THE EASTERN CONUS TROUGH TO THE EAST AS THE
MODELS SHOW THE UPPER RIDGE AXIS HAS MOVED INTO THE ATLANTIC BY
THURSDAY. IN THE LOWER LEVELS...SOUTHERLY FLOW WILL BRING
INCREASED MOISTURE THURSDAY. THE GFS AND ECMWF BRING THE
ASSOCIATED COLD FRONT INTO THE FORECAST AREA THURSDAY NIGHT OR
FRIDAY. THE MODELS HAVE BEEN CONSISTENT INDICATING A STRONG H85
JET ASSOCIATED WITH THE FRONT. THERE MAY BE ENOUGH INSTABILITY FOR
THUNDERSTORMS. THE MODELS SHIFT THE FRONT TO THE EAST AND OFFSHORE
SATURDAY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
MAINLY VFR CONDITIONS THROUGH THE TAF PERIOD. AN UPPER DISTURBANCE
NEAR THE AL/GA BORDER WILL CONTINUE TO SPREAD CLOUDS ACROSS THE AREA
TODAY. CIGS MAY DIP BELOW 10K FEET IN SOME LOCATIONS ESPECIALLY THIS
MORNING. A FEW SPRINKLES POSSIBLE AS WELL ESPECIALLY DURING THE
MORNING HOURS. AGS/DNL HAVE ALREADY REPORTED LIGHT RAIN EARLY THIS
MORNING. MOSTLY CLOUDY SKIES FOR MUCH OF TODAY AS THE SHORTWAVE
MOVES THROUGH THE REGION. HRRR HI RES MODEL INDICATING SOME PARTIAL
CLEARING BY THIS EVENING. WINDS WILL BE CALM EARLY THIS MORNING
BECOMING MAINLY SW AROUND 5 KNOTS BY LATE THIS MORNING.
EXTENDED AVIATION OUTLOOK...NO RESTRICTIONS TO AVIATION EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
631 AM EDT MON OCT 28 2013
.SYNOPSIS...
AN UPPER-LEVEL DISTURBANCE WILL MOVE OVER THE FORECAST AREA TODAY.
THIS SYSTEM WILL BRING CONSIDERABLE CLOUDINESS AND SPRINKLES WITH
JUST A SMALL CHANCE OF MEASURABLE RAIN. HIGH PRESSURE WILL BUILD
ACROSS THE REGION TUESDAY AND WEDNESDAY. A FRONTAL SYSTEM WILL
AFFECT THE AREA LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MOISTURE ASSOCIATED WITH THE REMNANTS OF A FRONT AND A MID-LEVEL
SHORTWAVE TROUGH WILL BE IN THE FORECAST AREA TODAY. THE SHORTWAVE
TROUGH WAS WELL DEFINED ON THE WATER VAPOR IMAGERY EARLY THIS
MORNING AND WAS HELPING SUPPORT SHOWERS OVER PART OF THE FORECAST
AREA. THE NAM AND GFS HAVE COME INTO GOOD AGREEMENT WITH LOW
POPS TODAY. ALL OF THE NAM AND GFS MOS SUPPORT POPS OF 20 PERCENT
OR LESS. THESE POPS AGREE WITH THE SREF GUIDANCE EXCEPT IT HAS
POPS NEAR 50 PERCENT OVER PART OF THE AREA. THE HIGH RESOLUTION
MODELS SHOW MIXED RESULTS WITH THE SPC WRF DISPLAYING LITTLE
COVERAGE AND HRRR SHOWING CONSIDERABLE COVERAGE AROUND 500 PM.
BASED ON THE H85 WESTERLY FLOW WITH LIMITED MOISTURE WE BELIEVE
SHOWER COVERAGE WILL REMAIN LIMITED AND MUCH OF THE AREA WILL NOT
HAVE MEASURABLE RAIN. FORECASTED POPS OF GENERALLY 20 TO 50
PERCENT. HOWEVER...BELIEVE MOST OF THE AREA WILL HAVE SPRINKLES
AT TIMES. THE COOLER GUIDANCE TEMPERATURES APPEAR BETTER BECAUSE
OF CLOUDINESS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
TONIGHT SHOULD BE DRY BEHIND THE MID-LEVEL SHORTWAVE TROUGH WITH
SURFACE RIDGING CONTINUING. THE MODELS MAINTAIN THE DRY PATTERN
THROUGH TUESDAY NIGHT. USED THE GUIDANCE CONSENSUS FOR THE
TEMPERATURE FORECAST.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE GFS AND ECMWF ARE IN GOOD AGREEMENT WEDNESDAY DISPLAYING
RIDGING WITH DRY WEATHER. THE MODELS SHOW THE STRONG UPPER LOW
OVER THE ROCKIES WILL LIFT OUT BY THURSDAY AND WILL EJECT A
VIGOROUS SHORTWAVE TROUGH THROUGH THE CENTRAL CONUS. THIS FEATURE
WILL BEGIN TO PUSH THE EASTERN CONUS TROUGH TO THE EAST AS THE
MODELS SHOW THE UPPER RIDGE AXIS HAS MOVED INTO THE ATLANTIC BY
THURSDAY. IN THE LOWER LEVELS...SOUTHERLY FLOW WILL BRING
INCREASED MOISTURE THURSDAY. THE GFS AND ECMWF BRING THE
ASSOCIATED COLD FRONT INTO THE FORECAST AREA THURSDAY NIGHT OR
FRIDAY. THE MODELS HAVE BEEN CONSISTENT INDICATING A STRONG H85
JET ASSOCIATED WITH THE FRONT. THERE MAY BE ENOUGH INSTABILITY FOR
THUNDERSTORMS. THE MODELS SHIFT THE FRONT TO THE EAST AND OFFSHORE
SATURDAY.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
MAINLY VFR CONDITIONS THROUGH THE TAF PERIOD. AN UPPER DISTURBANCE
NEAR THE AL/GA BORDER WILL CONTINUE TO SPREAD CLOUDS ACROSS THE AREA
TODAY. CIGS MAY DIP BELOW 10K FEET IN SOME LOCATIONS ESPECIALLY THIS
MORNING. A FEW SPRINKLES POSSIBLE AS WELL ESPECIALLY DURING THE
MORNING HOURS. AGS/DNL HAVE ALREADY REPORTED LIGHT RAIN EARLY THIS
MORNING. MOSTLY CLOUDY SKIES FOR MUCH OF TODAY AS THE SHORTWAVE
MOVES THROUGH THE REGION. HRRR HI RES MODEL INDICATING SOME PARTIAL
CLEARING BY THIS EVENING. WINDS WILL BE CALM EARLY THIS MORNING
BECOMING MAINLY SW AROUND 5 KNOTS BY LATE THIS MORNING.
EXTENDED AVIATION OUTLOOK...NO RESTRICTIONS TO AVIATION EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
707 AM CDT Mon Oct 28 2013
.UPDATE...
Issued at 559 AM CDT MON OCT 28 2013
Observing the band of stratus and dense advection fog lifting
northward across southern Kansas as warm and moist air encounters
the cooler airmass across east central areas. Latest few runs from
the HRRR as well as RAP soundings suggest weak southerly flow to
continue pulling the stratus deck northward along with
visibilities at or below 1/4 mile. Therefore have issued a Dense
Fog Advisory for portions of east central Kansas. As we near
sunrise, question as to if areas along the interstate 70 corridor
will see any mixing begin before stratus moves in. If we are able
to increase low level winds, dense fog will not be of concern.
Will continue to monitor trends for possible expansion northward
later this morning.
&&
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 330 AM CDT MON OCT 28 2013
Currently monitoring the next strong upper shortwave trough as it
rotates east southeast across northern California and northern
Nevada early this morning. Embedded perturbations within the main
system were noted ejecting eastward across the Intermountain west
while an area of subsidence over northeast Kansas was keeping skies
mostly clear. Surface observations note the low pressure center
across southeast Colorado as an inverted trough stretched across
Kansas and Missouri. Southerly winds over much of Kansas into
Oklahoma were pulling dewpoint temperatures in the lower and
middle 50s northward. Fog developing over Oklahoma should try to
make its way into southern Kansas later this morning. Low levels
have managed to stay mixed with temperature dewpoint spreads too large
to warrant widespread fog developing. Best chances for patchy fog
may be possible briefly near sunrise generally south of the Kansas
Turnpike.
The inverted trough deepens Monday afternoon as dewpoints increase
into the 50s across central and east central Kansas behind a warm
front positioned from west central Kansas to northwest Missouri.
Light winds veer to the south and increase through the low levels,
providing warm air advecting temps into the upper 60s and low 70s.
Short term guidance and analysis suggest a strong capping inversion
in place along with lack of strong forcing in the mid levels which
should keep much of the forecast dry for most of the afternoon. By
late afternoon into early evening, focus then turns west of the area
as mid level moisture and instability increases. Latest guidance
from the 4 km WRF and NAM suggest scattered convection may develop
after 5 PM across north central areas in vicinity of the warm front.
Surface based CAPE values are meager around 300 J/KG, however strong
veering of the winds throughout the column with effective shear up
to 6 km in the 50 kt range suggest if a surface based storm were
able to develop, supercell structures would be possible with large
hail and localized damaging winds being the primary concern.
Boundary layer should quickly stabilize towards sunset as widespread
showers and thunderstorms become more rooted in the mid levels. A
strong and veering low level jet overnight Monday along with a mid
level vort max in place should provide ample support for showers and
thunderstorms to spread eastward across the entire area through the
overnight hours. Mixed layer cape shifts east up to 1000 J/kg with
effective shear over 50 kts suggest isolated severe hail may
continue to be a threat for the area. Rainfall amounts around an
inch are possible especially across east central and northeast
areas. Within the warm sector, overcast skies, and scattered
convection low temperatures are expected to be much warmer in the
lower to middle 50s.
.LONG TERM...(Tuesday through Sunday)
Issued at 330 AM CDT MON OCT 28 2013
With the closed upper low now over the west coast and sampled
better, the models seem to be converging on the timing of the
system. And interestingly it seems as though the trend has been
towards the slightly faster solution of the GFS. Continued the
trend of the prev forecast with POPs diminishing Tuesday
afternoon. While there may be some precip ongoing early Tuesday,
large scale forcing for continued precip doesn`t appear to be
there. So with the weakening low level jet think a lull in precip
is possible Tuesday afternoon and Tuesday evening. The next
shortwave is progged to lift out from the base of the upper low on
Wednesday with the low itself moving across the state Wednesday
night. There should be more than enough moisture and with little
inhibition to convection so think showers and thunderstorms are
likely to be widespread once again. There continues to be a chance
that some of the storms Wednesday could become severe as deep
layer shear remains favorable for supercell storms. The main
uncertainty is whether there will be enough insolation to
destabilize the boundary layer and whether there will be a whole
bunch of storm interactions such that updrafts have a hard time
organizing into supercells. Nevertheless it bares watching. With
the strong low level moisture advection anticipated, temps should
be very mild for late October with highs around 70 and lows in the
upper 50s to lower 60s. The main adjustment to the forecast was to
account for the faster progression of the front on Thursday, which
most guidance brings through eastern KS by the mid morning hours.
With this in mind the forecast reflects diminishing POPs through
the morning with cooler minimum temps Thursday morning.
Friday through Sunday continues to look dry as the cold front
pushes all of the moisture east. Models show a wave within the
northwest flow for Friday, but there isn`t much moisture for it to
work with. The dry northwest flow is expected to persist through
Saturday before the next upper level shortwave trough moves
inland over the west coast causing pressure falls along the lee of
the Rockies and a southerly wind to return to the forecast area.
Temps Friday and Saturday still look to be seasonable before a
modest warm up occurs with increasing warm air advection from the
south on Sunday.
&&
.AVIATION...(For the 12Z TAFs through 12Z Tuesday Morning)
Issued at 559 AM CDT MON OCT 28 2013
Satellite continues to show band of LIFR stratus lifting northward
towards the terminals. The stratus is timed to reach KTOP/KFOE aft
14z and KMHK aft 15z. Low level winds will gradually mix out the
low stratus to VFR this afternoon as southeast winds increase at or
above 10 kts sustained. Scattered TSRA is expected to move into
the sites aft 03Z at KMHK and 04Z at KTOP/KFOE. Left VFR at this
time however lower cigs and visibilities are possible depending
on intensity of thunderstorm.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Bowen
SHORT TERM...Bowen
LONG TERM...Wolters
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
724 AM EDT MON OCT 28 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 435 AM EDT MON OCT 28 2013
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW POTENT SHRTWV
ACCOMPANIED BY 140KT H3 JET MAX SLIDING ESEWD THRU ONTARIO IN THE NW
FLOW ALF BTWN MEAN TROF OVER ERN CANADA AND A RDG OVER THE ROCKIES.
ATTENDANT COLD FNT PUSHED THRU UPR MI LAST EVNG ACCOMPANIED BY SOME
-SHRASN MAINLY OVER THE NRN TIER COUNTIES AND WAS FOLLOWED BY SOME
GUSTY N WINDS THAT PEAKED AS HI AS 41 KT AT THE STANNARD ROCK
LIGHTHOUSE IN SCENTRAL LK SUP. ALTHOUGH THE LARGE SCALE PCPN HAS
DIMINISHED FOLLOWING THE EXIT OF THE DEEPER MSTR...SOME LES AIDED BY
THE ARRIVAL OF H85 TEMPS DOWN TO -10 TO -11C IS OCCURRING NEAR LK
SUP...MAINLY OVER THE NCENTRAL WHERE LLVL NNE FLOW BTWN SFC HI PRES
IN SASKATCHEWAN THE DEPARTING COLD FNT IS PRESENTING A SHARPER
UPSLOPE WIND COMPONENT. BUT EVEN HERE THE LES IS RATHER LIGHT...WITH
CONSIDERABLE DEEP LYR QVECTOR DVGC/SUBSIDENCE DROPPING THE INVRN
BASE TOWARD 4K FT AND SHARPENING ACYC LLVL FLOW WEAKENING THE NEAR
SFC CNVGC. THE NEAR SFC LYR IN THE INCOMING AIRMASS IS NOT OVERLY
MOIST EITHER...WITH SFC DEWPT AT CKC IN THE MN ARROWHEAD DOWN TO 12F
AT 05Z AND HAS RESULTED IN CLRG JUST UPWIND OF THE LK. 00Z INL/YPL
RAOBS ALSO SHOW THIS DRYNESS. BUT MORE SC LINGERS FARTHER TO THE N
INTO ONTARIO/SRN MANITOBA/NW MN. THERE IS PARTIAL CLRG OVER FAR NW
ONTARIO W THRU LK WINNIPEG CLOSER TO THE SFC HI CENTER AND WHERE THE
00Z RAOB FM THE PAS MANITOBA SHOWS INVRN BASE BLO H9...BUT EVEN HERE
BKN SC ARE PRESENT.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE LES AND LO CLD TRENDS.
TODAY...UNDER CONFLUENT NW FLOW ALF...SFC HI PRES NOW CENTERED OVER
SASKATCHEWAN IS PROGGED TO DRIFT OVER NW MN BY 00Z TUE. EXPECT GUSTY
WINDS EARLY THIS MRNG TO DIMINISH STEADILY WITH THE ARRIVAL OF
FLATTER PRES GRADIENT. HIER RES MODELS INDICATE THE MOST PERSISTENT
SHSN IN LLVL N-NE FLOW WL IMPACT THE HIER TERRAIN OF THE NCENTRAL
AND THE FAR W FM ONTONAGON TO IWD...WHERE MOISTENING OFF LK NIPIGON
IS INDICATED TO HAVE A POSITIVE IMPACT. GOING POPS APPEAR TO HAVE
THESE TRENDS IN HAND. BUT THE SHARP LLVL ACYC FLOW/LO INVRN BASE
BTWN 3-4K FT/PRESENCE OF DGZ ABV THE RELATIVELY SHALLOW LK MOISTENED
LYR WL LIKELY HOLD DOWN SN ACCUMS TO NO MORE THAN AN INCH OR SO
DESPITE FVRBL LK WATER-INVRN BASE DELTA T ARND 17C. ALTHOUGH THERE
IS SOME CLRG IMMEDIATELY UPSTREAM OF THE LK RIGHT NOW...SUSPECT THE
BKN-OVC SC A BIT FARTHER TO THE N-NW AND SUBSTANTIAL OVERWATER
INSTABILITY ARE SIGNS THE LO CLDS WL BE QUITE RESILIENT. SO TENDED
TOWARD THE LOWER END OF GUIDANCE FOR MAX TEMPS.
TNGT...SFC HI PRES CENTER IS PROGGED TO DRIFT ALMOST RIGHT OVER UPR
MI BY 12Z TUE. WHILE THIS TREND WOULD SUG THE SC WL DSPT AND LO
TEMPS WL PLUNGE UNDER PWAT FALLING BLO 0.25 INCH/LGT WINDS...
CONCERNED THERE IS A GOOD AMOUNT OF LO CLD OBSVD THIS MRNG UPSTREAM
TO THE HI CENTER THAT COULD WREAK HAVOC WITH LO TEMPS FCST. SOME HI
CLDS MAY ALSO FILTER INTO THE AREA. WITH THE LLVL FLOW BACKING MORE
NW WITHIN LLVL THERMAL TROF...SUSPECT THE SC WL BE MOST TENACIOUS E
OF MQT. MAINTAINED FLAVOR OF PREVIOUS FCST SHOWING THE LOWEST TEMPS
OVER THE INTERIOR W HALF AND SCENTRAL INTO THE TEENS...BUT TENDED TO
RAISE THE FCST MINS A BIT TO ACCOUNT FOR THE UNCERTAINTY ON CLRG
TRENDS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 435 AM EDT MON OCT 28 2013
BRIEF PATTERN CHANGE REMAINS ON TRACK FOR THIS WEEK AS SPLIT FLOW
DEVELOPS. UPPER TROUGH THAT HAS BEEN OVER THE GREAT LAKES RECENTLY
SLIDES ACROSS EASTERN CANADA WHILE CUTOFF LOW SLOWLY MOVES FROM THE
WEST COAST TO THE CENTRAL PLAINS. 00Z MODELS STILL SHOWING SOME
DIFFERENCES BUT ARE STARTING TO COME TOGETHER IN TERMS OF POSITION
OF PLAINS UPPER LOW THROUGH WEDNESDAY. A BIT MORE DIFFERENCE BY
THURSDAY...BUT EVEN HERE THERE IS DECENT MODEL CLUSTERING OF
STRENGTH AND TRACK OF SFC LOW 00Z THURSDAY THROUGH 18Z THURSDAY.
MORE DIFFERENCES BEGIN TO EMERGE LATER THURSDAY INTO FRIDAY MAINLY
WITH REGARD TO HOW QUICKLY THE LOW EXITS THE UPPER GREAT LAKES. LOW
PRESSURE MOSTLY RESULTS IN A RAIN EVENT FOR MID-LATE WEEK WITH SNOW
RE-ENTERING THE PICTURE BY NEXT WEEKEND AS COLDER AIR FILTERS ACROSS
THE GREAT LAKES IN WAKE OF THE LOW PRESSURE SYSTEM.
LARGE SPRAWLING HIGH PRESSURE OF 1033MB WILL BE CENTERED VERY NEAR
UPR MICHIGAN TO START THE DAY ON TUESDAY WHILE AN INITIAL WAVE OF
LOW PRESSURE FORMS IN THE SOUTHERN PLAINS. EVEN THOUGH A RIDGE OF
HIGH PRESSURE HOLDS AT THE SFC THROUGH TUESDAY NIGHT OVER THE UPPER
GREAT LAKES...HINT IS THERE FOR A WHILE THAT THERE MAY BE SOME LIGHT
PRECIP OVER THE AREA THROUGH THE EVENING. MAIN INSTIGATOR FOR THE
PRECIP IS SHORTWAVE DROPPING ACROSS NORTHERN ONTARIO IN NW FLOW ON
WESTERN EDGE OF RETREATING TROUGHING. MOST OF LARGER SCALE FORCING
FOR ASCENT FM SHORTWAVE /H7-H5 AND H5-H3 Q-VECTOR CONVERGENCE/ STAYS
NORTH OF CWA. HOWEVER...INCREASE IN MOISTURE AND WARM AIR ADVECTION
TEAMS UP WITH DIVERGENCE ALOFT FM JET STREAK SLIDING EAST TOWARD
QUEBEC TO GENERATE SOME MID-LEVEL LIFT. LEFTOVER ISSUE IS WHETHER
LOW-LEVEL DRY AIR OWING TO THE SFC HIGH WILL BE ERODED ENOUGH TO
RESULT IN PRECIP MAKING IT TO THE SFC. /THIS IS OF COURSE ASSUMING
THAT LOW CLOUDS AROUND TONIGHT DO IN FACT CLEAR OUT LATER TONIGHT OR
TUESDAY MORNING/. SINCE THE DRYING WILL NOT BE RE-INFORCED BY DRY
ADVECTION...THINK MID-LEVEL MOISTURE AND LIFT EVENTUALLY ALLOWS LGT
PRECIP TO MAKE IT TO SFC. SOUNDINGS FM THE NAM AND THICKNESSES
INDICATE MAINLY SNOW FOR PTYPE. ONLY SCNTRL WITH LGT SE WINDS OFF LK
MICHIGAN MAY SEE RAIN BE MAIN PTYPE.
WHERE SNOW OCCURS AS PTYPE...THERE IS A LEAST SOME CHANCE OF MINOR
ACCUMS AS...DESPITE IT HAPPENING IN THE AFTN/EVENING...BANDED SNOW
COULD FALL AT AN OKAY CLIP WITH STRONGER FORCING IN MID-LEVELS. NAM
WHICH IS GRANTED THE MOST AGGRESSIVE WITH QPF AND DURATION OF
HEAVIER QPF SHOWS SNOW ACCUMS OVER 2 INCHES OVER SOUTHWEST CWA 18Z
TUE THROUGH 06Z WED. WILL NOT GO THIS BULLISH YET AS THE NAM IS AN
OUTLIER...BUT WILL BUMP POPS UP TO HIGHER CHANCE RANGE. ECMWF/GEM-NH
AND UKMET ALSO GENERATING QPF OVR UPR MICHIGAN BUT NOT NEAR AS HEAVY
AS NAM. TIMING AND EXTENT OF SNOW SOMETHING TO KEEP AWARE OF AS IT
COULD IMPACT EVENING TRAVEL OVER SOUTHWEST UPR MICHIGAN AND MAYBE
INTO CNTRL AND EASTERN CWA.
DECENT AGREEMENT THAT LGT PRECIP TAPERS OFF BY LATER EVENING AS
MAIN JET STREAK MOVES FARTHER EAST AND MID-LEVEL MOISTURE DEPARTS.
LOW-LEVEL MOISTURE REMAINS THROUGH THE REST OF TUESDAY NIGHT WITH
VERY WEAK WINDS AS SFC RIDGE AXIS LINGERS. COULD SEE SOME FOG WITH
THIS SETUP IF MOISTURE THINS OUT MORE THAN SHOWN ON SOUNDINGS. AT
THE LEAST SOME STRATUS SHOULD PERSIST INTO WEDNESDAY. LOW-LEVEL
WINDS GRADUALLY BECOME MORE SOUTHEASTERLY TO THE NORTH OF WARM
FRONT...WHICH BASED ON SFC WINDS/DWPNT GRADIENT...COULD BE AS FAR
NORTH AS CNTRL WISCONSIN BY 00Z THURSDAY. SE WINDS MAY HOLD IN
STRATUS MOST OF THE DAY OVER UPSLOPE AREAS OF CNTRL UPR MICHIGAN
THANKS TO LESS MIXING DUE TO LOWER SUN ANGLE THIS TIME OF YEAR.
ELSEWHERE...WOULD EXPECT INCREASING HIGH AND MID CLOUDS OUT AHEAD
OF DEVELOPING PLAINS SYSTEM AND WARM FRONT. MAIN QUESTION FOR
WEDNESDAY IS WHETHER PRECIP MOVES BACK IN THROUGH THE DAY. GFS WOULD
SUGGEST SO...WHILE THE ECMWF/GEM-NH AND UKMET KEEP QPF SOUTH OF CWA
UNTIL WEDNESDAY NIGHT. EVEN GFS HAS SHOWN A TREND TOWARD DRIER
WEATHER HOLDING...AT LEAST OVER THE NORTHERN CWA. HAVE SLIGHT CHANCE
POPS GOING AND THAT PROBABLY WORKS FOR NOW...AT LEAST UNTIL MORE
SIGNAL SHOWS UP THAT WARM FRONT AND PRECIP WILL BE FARTHER NORTH.
SUPPOSE THERE COULD BE SOME DRIZZLE FM THAT PERSISTING LOW CLOUD
DECK AND UPSLOPE FLOW. SLIGHT CHANCES COVER THIS JUST FINE FOR NOW.
LOWERED MAX TEMPS OVER THE WEST HALF INTO LOWER 40S WITH PERSISTING
CLOUDS.
RAIN IS STILL ON FOR WEDNESDAY NIGHT AS PLAINS UPPER TROUGH HEADS
EAST AND PROPELS DEEPENING SFC LOW TOWARD UPR LAKES...VCNTY OF
NORTHERN WI OR UPR MICHIGAN BY 12Z THURSDAY WITH MSLP SOMEWHERE NEAR
990MB. MOISTURE ADVECTION AND WARM AIR ADVECTION AHEAD OF LOW WILL
COMBINE WITH STRONG DIVERGENCE ALOFT ON NOSE OF 140+ KT JET STREAK
ROARING NORTHEAST OUT OF THE CENTRAL PLAINS. PWATS OVER 1 INCH OR
OVER 200 PCT OF NORMAL COMBINE WITH THE FORCING TO SPREAD A SWATH OF
MODERATE RAIN ACROSS ALL CWA. STILL SOME SMALL TIMING DIFFERENCES AS
THE GFS/GEM-NH QUICKER IN BRINGING RAIN ACROSS THE AREA. ECMWF IS
SLOWER BY ABOUT 6 HRS. KEPT A BROADBRUSHED 80 PCT CHANCE FOR
WEDNESDAY NIGHT. REFINEMENTS TO TIMING CAN BE MADE LATER ON. DRY
SLOT LIKELY BECOMES A FACTOR INTO DAYTIME HOURS ON THURSDAY...YET
MAY SEE AN ADDITIONAL AREA OF ENHANCED RAIN FROM DEFORMATION
INDICATED BY H7-H5/H5-H3 Q-VECTOR CONVERGENCE. HIGHEST POPS ON
THURSDAY WILL BE IN THE EAST CLOSER TO LOW-LEVEL JET AXIS AND H85-H7
MOISTURE TRANSPORT. WARMEST DAY OF THE WEEK ON THURSDAY WITH MAX
TEMPS INTO THE 50S. BASED ON LOCATION OF DRY SLOT AND H7-H5 LAPSE
RATES...TSRA PROBABLY END UP FIRING JUST TO THE SOUTH AND EAST OF
CWA...SO LEFT THAT OUT FOR NOW. WINDS PROBABLY WILL BE A FACTOR
SOMETIME ALONG THE WAY AS WELL GIVEN THE DEEPENING LOW AND WITH
TIGHT PRESSURE GRADIENT/STRONG WIND FIELDS FORECAST IN THE VCNTY OF
THE LOW. BEST CHANCE FOR ADVY GUSTS WOULD BE ALONG LK MICHIGAN LATER
WEDNESDAY NIGHT INTO THURSDAY MORNING...THEN ALONG LK SUPERIOR ONCE
LOW MOVES BY THURSDAY NIGHT INTO FRIDAY MORNING.
MID-LEVEL TROUGHING LINGERS FROM FRIDAY INTO NEXT WEEKEND AND THERE
ARE INDICATIONS THERE COULD BE A COUPLE PERIODS OF ENHANCED PRECIP
CHANCES IN THE MEAN TROUGHING AS SHORTWAVES AND/OR RE-INFORCING COLD
FRONTS SLIDE THROUGH. COLDER AIR CHARGES BACK IN ON FRIDAY. BASED ON
1000-850MB AND 850-700MB THICKNESSES FM ECMWF/GFS SHOULD START TO
SEE SNOW MIXING IN ON FRIDAY OVER AT LEAST WEST HALF INTERIOR.
AIRMASS CHILL INTO NEXT WEEKEND IS SIMILAR TO RECENT STRETCH OF
COOLER TEMPS WITH H85 TEMPS DOWN BLO -6C BUT NOT QUITE TO -12C.
SINCE THERE LOOKS TO BE SOME DEEPER MOISTURE AROUND AS
WELL...PROBABLY WILL HAVE TO CONTEND WITH LAKE ENHANCED RAIN AND
SNOW SHOWERS AT TIMES. SOME SNOW ACCUMULATION WOULD BE FAVORED AT
TIMES FOR THE FAVORED LAKE EFFECT AREAS NEAR LK SUPERIOR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 724 AM EDT MON OCT 28 2013
AS CHILLY AND SOMEWHAT MOISTER AIR TO THE N FLOWS OVER THE
RELATIVELY WARM LAKE SUP WATERS...VFR CIGS AT CMX AND ESPECIALLY SAW
WITH MORE FVRBL UPSLOPE NNE WIND FLOW AHEAD OF APRCHG SFC HI PRES
SHOULD DETERIORATE TO MVFR. SINCE THIS WIND DOWNSLOPES AT IWD...
CONDITIONS THERE MAY REMAIN VFR. AS THE HI MOVES OVHD TNGT...VFR
CONDITIONS SHOULD PREDOMINATE AS ANY LINGERING LO CLDS BREAK UP.
OTRW...GUSTY WINDS EARLY AT SAW WL GIVE WAY TO LGT WINDS AS THE HI
GETS CLOSER AND THE PRES GRADIENT SLACKENS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 435 AM EDT MON OCT 28 2013
WITH HI PRES BUILDING TOWARD THE UPPER GREAT LAKES...EXPECT N WINDS
UP TO 30 KTS EARLY THIS MORNING TO DIMINISH STEADILY THRU THE DAY
AND TO BECOME LIGHT TONIGHT AS THE HI CENTER MOVES OVER THE AREA.
THESE LIGHT WINDS LESS THAN 20 KTS STAY IN PLACE TUESDAY THROUGH
WEDNESDAY AS HIGH PRESSURE PERSISTS THEN EXPECT INCREASING SE-E
WINDS LATER WEDNESDAY NIGHT OUT AHEAD OF DEEPENING LOW PRESSURE IN
THE MIDDLE MISSISSIPPI RIVER VALLEY. LOW FORECAST TO LIFT ACROSS LK
SUPERIOR BY THURSDAY NIGHT. DEPENDING ON TRACK OF LOW...WINDS MAY
DIMINISH FOR A TIME ON THURSDAY. YET...ONCE THE LOW MOVES TO THE EAST
OF LK SUPERIOR...NORTHWEST WINDS INCREASE TO 30 KTS THURSDAY NIGHT
INTO FRIDAY. HIGH PRESSURE QUICKLY BUILDING IN ALONG WITH COLD AIR
ADVECTION COULD ALLOW FOR SOME GALES TO OCCUR. STRONG NORTHWEST WINDS
TO 30 KTS CONTINUE INTO NEXT WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...KC
MARINE...KC/JLA
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
655 AM CDT Mon Oct 28 2013
.SHORT TERM: (Through Late This Afternoon)
Issued at 308 AM CDT Mon Oct 28 2013
One more day of quiet weather across the Bi-State Region as a weak
upper level ridge moves across the Mississippi Valley. Should see
plenty of sunshine today due to the dry air which remains locked in
place over the region; though higher clouds will be increasing later
in the day as the subtropical jet draws Pacific moisture up ahead of
the the strong cutoff low over California and Nevada. Surface
cyclogenesis will ramp up over eastern Colorado today which will
increase southerly flow across the southern Plains and Deep South.
This will help to develop a warm front between a strong Canadian
high diving into the Upper Midwest and warm moist Gulf of Mexico air
trying to build up from the south. The NAM suggests that the front
may make it much of the way through Missouri and perhaps parts of
southwest Illinois, while the GFS and RAP aren`t as aggressive.
Either way, not sure there will be much difference in sensible
weather other than higher levels of surface humidity. Surface
temperatures are nearly identical for today on all short range
guidance, so have followed guidance numbers closely.
Carney
.LONG TERM:
(Tonight through Sunday) Issued at 308 AM CDT Mon Oct 28 2013
(Tonight through Thursday Night)
Little change required as going forecast has a good handle on the
situation. Still appears that this will be an active period
beginning late tonight with the likelihood of a widespread soaking
rain with potential for a few strong thunderstorms.
Followed the ECMWF which has been the most consistent with the
overall evolution of the weather pattern the next few days. Most of
tonight will remain dry until strong moisture convergence moves into
central Missouri after 09Z on the nose of a 45kt low level jet.
This low level forcing will move in concert with a shortwave trough
across the CWA tomorrow morning. Will have likely or categorical
pops going over central Missouri starting late tonight and then
spread them eastward across eastern Missouri into southwest Illinois
tomorrow morning.
Then showers and thunderstorms will become more scattered on Tuesday
afternoon and Tuesday Night as the shortwave passes to the east.
The ECMWF depicts an upper ridge moving east across the Midwest
through 12Z Wednesday. Thereafter, strong mid level ascent will
set up between midday Wednesday until the trough currently over
the western CONUS passes through our area on Thursday. Strong
moisture transport and convergence will be occurring beneath this mid
level ascent ahead of the approaching attendant surface cold
front. Likely or categorical pops for showers and thunderstorms
are still warranted ahead of the front Wednesday into Thursday.
There will continue to be the potential for strong thunderstorms
during this period given the very strong low level and deep layer
shear. Risk remains conditional on the amount of instability that
will be available which will be dependent on how much precipitation
is occurring ahead of the front. Will go ahead a mention the
potential for a few strong thunderstorms in the Hazardous Weather
Outlook.
Will keep a lingering chance of showers on Thursday night behind the
cold front. MOS temperatures are in good agreement and generally
followed.
(Friday Through Sunday)
There is good agreement that late week into next weekend will be
dry behind Thursday`s cold front. Both the GFS/ECMWF brings a
second upper trough with an attendant cold front through the
Midwest on Friday, though forcing and moisture looks to be too
limited to warrant any mention of rain chances at this point. This
trough will then move east and upper heights will rise as a ridge
builds in from the west.
Britt
&&
.AVIATION: (For the 12z TAFs through 12z Tuesday Morning)
Issued at 632 AM CDT Mon Oct 28 2013
Primary concern this morning is the area of IFR CIGS/VSBYS moving
north toward central and southeast Missouri out of Arkansas.
Current satellite trends have the clouds/fog moving into parts of
Cole and Moniteau counties between 1345-1400Z, and somewhat
earlier for parts of Reynolds county. This will be 45 minutes to
more than an hour after sunrise...so current thinking is that the
stratus will slow down and stop before it makes significant
penetration into our area. While this is the most likely scenario,
it is certainly possible that the stratus will keep on trucking
northeast and blanket much of the area along and south of the
I-70 corridor, but I think the probability of this is low.
The remainder of the period through 12Z Tuesday should be VFR with
light east-southeast flow. Some light rain is possible in central
and northwest Missouri after 09Z Tuesday, but the more significant
precipitation looks to hold off until later in the morning.
Specifics for KSTL:
Expect VFR flight conditions and light east-southeast flow at
least through 12Z Tuesday. The stratus/fog over southwest Missouri
should stop moving northeast shortly after sunrise. There is an
outside chance that it could keep moving up into east central
Missouri, but I think this is a very low probability. Attention
turns to Tuesday when a period of wet weather is expected to
begin. There may be some light rain between 12Z and 15Z Tuesday
morning, however it appears that the more significant rain and
lowering CIGS/VSBYS will hold off until 18Z or later.
Carney
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1127 AM EDT MON OCT 28 2013...CORRECTED FOR AVIATION
.SYNOPSIS...
LOW PRESSURE PASSES SOUTH OF THE AREA EARLY THIS EVENING. A WARM
FRONT MOVES NORTHWARD TUESDAY NIGHT AND WEDNESDAY...BRINGING MILDER
AIR. STRONG COLD FRONT WITH SHOWERS THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
1015 AM UPDATE. INCREASED POPS ACROSS THE SOUTH HALF OF THE AREA PER
RADAR...SATELLITE...AND HI RES MODEL TRENDS. WENT WITH CAT POPS
ACROSS SOUTHWEST VIRGINIA AND SOUTHERN WEST VIRGINIA...ALTHOUGH QPF
WILL GENERALLY BE LESS THAN THE A TENTH OF AN INCH. SUNSHINE
PREVAILS ACROSS THE NORTH.
630 AM UPDATE...
HAD TO NUDGE THE N EDGE OF CLD SHIELD UP THIS MORNING TO INCLUDE
HTS TO CRW CORRIDOR...PERHAPS EVEN N OF THERE PER LATEST RUC.
OTHERWISE...NO MAJOR CHANGES. STILL LOOKING FOR SHRA ACROSS SW VA
AND SE WV TDY.
PREVIOUS DISCUSSION BELOW...
NOT MUCH CHANGE IN FCST THINKING FROM DAY SHIFT. DID ELECT TO BUMP
UP POPS ACROSS SW VA INTO LKLY MID TO LATE MORNING PER LATEST MDL
RUNS. TIGHT POP GRADIENT WITH CHC GETTING INTO COAL FIELDS TO SE
WV...WITH NOTHING N OF THERE. ALSO LOOKING AT A TIGHT GRADIENT TO
SKY GRIDS AS WELL. WENT WITH SOLID OVC ACROSS SW VA AND S WV TDY.
HARD TO SAY IF OVC REACHES AS FAR N AT HTS TO CRW CORRIDOR. DID
ALLOW FOR BKN COVERAGE THOUGH WITH CIRRUS ACROSS SE OH AND N WV.
UPR LVL DISTURBANCE RESPONSIBLE FOR WX TDY SHIFT E OF CWA THIS
AFTN AND BEGIN TO QUICKLY RAMP DOWN POPS THIS AFTN ACROSS S ZONES.
ABUNDANCE OF LLVL MOISTURE WILL LINGER THOUGH THROUGH THIS AFTN
AND A GOOD CHUNK OF THE NIGHT ACROSS S WV/SW VA...THUS KEPT
PESSIMISTIC SKY COVERAGE ACROSS THOSE LOCALES WITH SOME CIRRUS
ELSEWHERE.
INGESTED LATEST HRRR AS A BASE FOR TEMPS TDY AND
TONIGHT...TWEAKING S ZONES FOR COOLER WX PER CLDS/SHRA THREAT.
TRIED TO GO TOWARD WARMER MET ACROSS SE OH AND N WV WHERE AT LEAST
FILTERED SUN WILL BE REALIZED. SAME GENERAL THINKING HOLDS TONIGHT
AS WELL...WITH WARMER READINGS ACROSS SW VA AND S WV...WITH COOLER
READINGS FOR SE OH AND N WV.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
NAM IS MUCH STRONGER WITH A FEATURE TUESDAY NIGHT THAN OTHER
MODELS...BUT MUCH OF THIS ENERGY CAN BE TRACED BACK TO CONVECTIVE
FEEDBACK IN THE MID WEST. THEREFORE...WILL KEEP POPS LOW AS GFS
WOULD KEEP MOST PRECIPITATION TO OUR NORTHWEST. MODELS ARE FAIRLY
CONSISTENT WITH A COLD FRONT MOVING THROUGH THURSDAY NIGHT.
THEREFORE...WILL RAISE POPS THURSDAY NIGHT...AND REMOVE POPS BEHIND
FRONT FRIDAY AFTERNOON AND EVENING.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
GENERALLY FOLLOWED WPC THINKING WITH THE EXTENDED PORTION OF THE
FORECAST...WITH A LEANING TOWARDS THE EC/CMC PER ENSEMBLE SUPPORT.
UPPER RIDGE AXIS OVER THE FORECAST AREA AT THE OUTSET OF THE PERIOD
WILL QUICKLY PUSH OFF TO THE EAST WITH A POTENT SYSTEM PUSHING OUT
OF THE CENTRAL ROCKIES TOWARDS THE UPPER MIDWEST...AND SFC COLD
FRONT MARCHING EASTWARD ACROSS THE MISS VALLEY. BASED ON THE SLOWER
PROGRESSION OF NWP CONSENSUS...LOOKS LIKE THURSDAY WILL BE WARM WITH
THE BULK OF THE PRECIP HOLDING OFF UNTIL THURSDAY NIGHT AND FRIDAY
MORNING WITH THE COLD FRONT. PRECIP EXITS TO THE EAST FRIDAY
AFTERNOON...BUT SW FLOW ALOFT CONTINUES OVER THE AREA AS UPPER
TROUGH CONTINUES TO DIG ACROSS THE GREAT LAKES AND OHIO RIVER
VALLEY. AS THE TROUGH MOVES OVERHEAD SATURDAY...WILL CONTINUE SLIGHT
CHANCE POPS MAINLY ACROSS THE NORTHERN ZONES AND EASTERN MOUNTAINS.
FLOW TURNS NORTHWEST BEHIND THE TROUGH AXIS ON SUNDAY YET WITH SOME
LLVL MOISTURE TRAPPED...WILL KEEP THE SLIGHT CHANCE POPS IN ROUGHLY
THE SAME LOCATIONS AS SATURDAY. TEMPERATURES WILL BE PROGRESSIVELY
COOLER WITH EACH PASSING DAY THROUGH THE EXTENDED...DROPPING FROM
THE LOWER 70S LOWLANDS ON THURSDAY TO AROUND THE 50 DEGREE MARK BY
SUNDAY FOR THE LOWLANDS.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
15Z MONDAY THRU 12Z...
UPR LVL SYS WILL PASS S OF AREA THIS AFTERNOON...WITH SHRA EXPECTED
FOR SW VA AND SRN WV THRU 00Z. EXCEPT FOR IFR FAR SOUTH...GENERALLY
KEPT MVFR GOING THIS AFTERNOON IN THE SOUTH WHERE SHOWERS
OCCUR...INCLUDING BKW. ELSEWHERE...VFR. DECREASING VFR CLOUDS THE
FARTHER NORTH YOU GO...WITH SCT CLOUDS NORTH OF A 3I2 TO W22 LINE.
UPPER LVL SYS EXITS THIS EVENING...TAKING SHOWERS WITH IT. HOWEVER
ABUNDANT LLVL MOISTURE WILL REMAIN ACROSS SW VA AND S WV TONIGHT
WHICH MAY HOLD IN MVFR/IFR CIGS. OTHERWISE JUST SOME PASSING
CIRRUS SE OH/N WV WHERE SOME LATE LIFR/IFR RVR FG MAY BE REALIZED.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATIVE SCENARIOS: OVC DECK MAY MAKE IT INTO KHTS/KCRW FOR
TDY...BUT STILL WOULD REMAIN VFR.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H M M M M
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY M H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z TUESDAY...
IFR OR WORSE IN RVR VALLEY FG POSSIBLE TUES MORNING ACROSS SE OH/N
WV. IFR POSSIBLE IN SHOWERS THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/JMV/50/30
NEAR TERM...JMV/30
SHORT TERM...RPY
LONG TERM...ARJ
AVIATION...JMV/30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1127 AM EDT MON OCT 28 2013
.SYNOPSIS...
LOW PRESSURE PASSES SOUTH OF THE AREA EARLY THIS EVENING. A WARM
FRONT MOVES NORTHWARD TUESDAY NIGHT AND WEDNESDAY...BRINGING MILDER
AIR. STRONG COLD FRONT WITH SHOWERS THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
1015 AM UPDATE. INCREASED POPS ACROSS THE SOUTH HALF OF THE AREA PER
RADAR...SATELLITE...AND HI RES MODEL TRENDS. WENT WITH CAT POPS
ACROSS SOUTHWEST VIRGINIA AND SOUTHERN WEST VIRGINIA...ALTHOUGH QPF
WILL GENERALLY BE LESS THAN THE A TENTH OF AN INCH. SUNSHINE
PREVAILS ACROSS THE NORTH.
630 AM UPDATE...
HAD TO NUDGE THE N EDGE OF CLD SHIELD UP THIS MORNING TO INCLUDE
HTS TO CRW CORRIDOR...PERHAPS EVEN N OF THERE PER LATEST RUC.
OTHERWISE...NO MAJOR CHANGES. STILL LOOKING FOR SHRA ACROSS SW VA
AND SE WV TDY.
PREVIOUS DISCUSSION BELOW...
NOT MUCH CHANGE IN FCST THINKING FROM DAY SHIFT. DID ELECT TO BUMP
UP POPS ACROSS SW VA INTO LKLY MID TO LATE MORNING PER LATEST MDL
RUNS. TIGHT POP GRADIENT WITH CHC GETTING INTO COAL FIELDS TO SE
WV...WITH NOTHING N OF THERE. ALSO LOOKING AT A TIGHT GRADIENT TO
SKY GRIDS AS WELL. WENT WITH SOLID OVC ACROSS SW VA AND S WV TDY.
HARD TO SAY IF OVC REACHES AS FAR N AT HTS TO CRW CORRIDOR. DID
ALLOW FOR BKN COVERAGE THOUGH WITH CIRRUS ACROSS SE OH AND N WV.
UPR LVL DISTURBANCE RESPONSIBLE FOR WX TDY SHIFT E OF CWA THIS
AFTN AND BEGIN TO QUICKLY RAMP DOWN POPS THIS AFTN ACROSS S ZONES.
ABUNDANCE OF LLVL MOISTURE WILL LINGER THOUGH THROUGH THIS AFTN
AND A GOOD CHUNK OF THE NIGHT ACROSS S WV/SW VA...THUS KEPT
PESSIMISTIC SKY COVERAGE ACROSS THOSE LOCALES WITH SOME CIRRUS
ELSEWHERE.
INGESTED LATEST HRRR AS A BASE FOR TEMPS TDY AND
TONIGHT...TWEAKING S ZONES FOR COOLER WX PER CLDS/SHRA THREAT.
TRIED TO GO TOWARD WARMER MET ACROSS SE OH AND N WV WHERE AT LEAST
FILTERED SUN WILL BE REALIZED. SAME GENERAL THINKING HOLDS TONIGHT
AS WELL...WITH WARMER READINGS ACROSS SW VA AND S WV...WITH COOLER
READINGS FOR SE OH AND N WV.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
NAM IS MUCH STRONGER WITH A FEATURE TUESDAY NIGHT THAN OTHER
MODELS...BUT MUCH OF THIS ENERGY CAN BE TRACED BACK TO CONVECTIVE
FEEDBACK IN THE MID WEST. THEREFORE...WILL KEEP POPS LOW AS GFS
WOULD KEEP MOST PRECIPITATION TO OUR NORTHWEST. MODELS ARE FAIRLY
CONSISTENT WITH A COLD FRONT MOVING THROUGH THURSDAY NIGHT.
THEREFORE...WILL RAISE POPS THURSDAY NIGHT...AND REMOVE POPS BEHIND
FRONT FRIDAY AFTERNOON AND EVENING.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
GENERALLY FOLLOWED WPC THINKING WITH THE EXTENDED PORTION OF THE
FORECAST...WITH A LEANING TOWARDS THE EC/CMC PER ENSEMBLE SUPPORT.
UPPER RIDGE AXIS OVER THE FORECAST AREA AT THE OUTSET OF THE PERIOD
WILL QUICKLY PUSH OFF TO THE EAST WITH A POTENT SYSTEM PUSHING OUT
OF THE CENTRAL ROCKIES TOWARDS THE UPPER MIDWEST...AND SFC COLD
FRONT MARCHING EASTWARD ACROSS THE MISS VALLEY. BASED ON THE SLOWER
PROGRESSION OF NWP CONSENSUS...LOOKS LIKE THURSDAY WILL BE WARM WITH
THE BULK OF THE PRECIP HOLDING OFF UNTIL THURSDAY NIGHT AND FRIDAY
MORNING WITH THE COLD FRONT. PRECIP EXITS TO THE EAST FRIDAY
AFTERNOON...BUT SW FLOW ALOFT CONTINUES OVER THE AREA AS UPPER
TROUGH CONTINUES TO DIG ACROSS THE GREAT LAKES AND OHIO RIVER
VALLEY. AS THE TROUGH MOVES OVERHEAD SATURDAY...WILL CONTINUE SLIGHT
CHANCE POPS MAINLY ACROSS THE NORTHERN ZONES AND EASTERN MOUNTAINS.
FLOW TURNS NORTHWEST BEHIND THE TROUGH AXIS ON SUNDAY YET WITH SOME
LLVL MOISTURE TRAPPED...WILL KEEP THE SLIGHT CHANCE POPS IN ROUGHLY
THE SAME LOCATIONS AS SATURDAY. TEMPERATURES WILL BE PROGRESSIVELY
COOLER WITH EACH PASSING DAY THROUGH THE EXTENDED...DROPPING FROM
THE LOWER 70S LOWLANDS ON THURSDAY TO AROUND THE 50 DEGREE MARK BY
SUNDAY FOR THE LOWLANDS.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
15Z MONDAY THRU 12Z...
UPR LVL SYS WILL PASS S OF AREA THIS AFTERNOON...WITH SHRA EXPECTED
FOR SW VA AND SRN WV THRU 00Z. KEPT MVFR CIGS GOING TYHIS
AFTERNOON FOR THE SOUTH WHERE SHOWERS OCCUR...INCLUDING BKW.
ELSEWHERE...VFR. DECREASING VFR CLOUDS THE FARTHER NORTH YOU
GO...WITH SCT CLOUDS NORTH OF A 3I2 TO W22 LINE.
UPPER LVL SYS EXITS THIS EVENING...TAKING SHOWERS WITH IT. HOWEVER
ABUNDANT LLVL MOISTURE WILL REMAIN ACROSS SW VA AND S WV TONIGHT
WHICH MAY HOLD IN MVFR CIGS FOR KBKW. OTHERWISE JUST SOME PASSING
CIRRUS SE OH/N WV WHERE SOME LATE LIFR/IFR RVR FG MAY BE REALIZED.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATIVE SCENARIOS: OVC DECK MAY MAKE IT INTO KHTS/KCRW FOR
TDY...BUT STILL WOULD REMAIN VFR.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H M M M M
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY M H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z TUESDAY...
IFR OR WORSE IN RVR VALLEY FG POSSIBLE TUES MORNING ACROSS SE OH/N
WV. IFR POSSIBLE IN SHOWERS THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/JMV/50/30
NEAR TERM...JMV/30
SHORT TERM...RPY
LONG TERM...ARJ
AVIATION...JMV/30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1026 AM EDT MON OCT 28 2013
.SYNOPSIS...
LOW PRESSURE PASSES SOUTH OF THE AREA EARLY THIS EVENING. A WARM
FRONT MOVES NORTHWARD TUESDAY NIGHT AND WEDNESDAY...BRINGING MILDER
AIR. STRONG COLD FRONT WITH SHOWERS THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
1015 AM UPDATE. INCREASED POPS ACROSS THE SOUTH HALF OF THE AREA PER
RADAR...SATELLITE...AND HI RES MODEL TRENDS. WENT WITH CAT POPS
ACROSS SOUTHWEST VIRGINIA AND SOUTHERN WEST VIRGINIA...ALTHOUGH QPF
WILL GENERALLY BE LESS THAN THE A TENTH OF AN INCH. SUNSHINE
PREVAILS ACROSS THE NORTH.
630 AM UPDATE...
HAD TO NUDGE THE N EDGE OF CLD SHIELD UP THIS MORNING TO INCLUDE
HTS TO CRW CORRIDOR...PERHAPS EVEN N OF THERE PER LATEST RUC.
OTHERWISE...NO MAJOR CHANGES. STILL LOOKING FOR SHRA ACROSS SW VA
AND SE WV TDY.
PREVIOUS DISCUSSION BELOW...
NOT MUCH CHANGE IN FCST THINKING FROM DAY SHIFT. DID ELECT TO BUMP
UP POPS ACROSS SW VA INTO LKLY MID TO LATE MORNING PER LATEST MDL
RUNS. TIGHT POP GRADIENT WITH CHC GETTING INTO COAL FIELDS TO SE
WV...WITH NOTHING N OF THERE. ALSO LOOKING AT A TIGHT GRADIENT TO
SKY GRIDS AS WELL. WENT WITH SOLID OVC ACROSS SW VA AND S WV TDY.
HARD TO SAY IF OVC REACHES AS FAR N AT HTS TO CRW CORRIDOR. DID
ALLOW FOR BKN COVERAGE THOUGH WITH CIRRUS ACROSS SE OH AND N WV.
UPR LVL DISTURBANCE RESPONSIBLE FOR WX TDY SHIFT E OF CWA THIS
AFTN AND BEGIN TO QUICKLY RAMP DOWN POPS THIS AFTN ACROSS S ZONES.
ABUNDANCE OF LLVL MOISTURE WILL LINGER THOUGH THROUGH THIS AFTN
AND A GOOD CHUNK OF THE NIGHT ACROSS S WV/SW VA...THUS KEPT
PESSIMISTIC SKY COVERAGE ACROSS THOSE LOCALES WITH SOME CIRRUS
ELSEWHERE.
INGESTED LATEST HRRR AS A BASE FOR TEMPS TDY AND
TONIGHT...TWEAKING S ZONES FOR COOLER WX PER CLDS/SHRA THREAT.
TRIED TO GO TOWARD WARMER MET ACROSS SE OH AND N WV WHERE AT LEAST
FILTERED SUN WILL BE REALIZED. SAME GENERAL THINKING HOLDS TONIGHT
AS WELL...WITH WARMER READINGS ACROSS SW VA AND S WV...WITH COOLER
READINGS FOR SE OH AND N WV.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
NAM IS MUCH STRONGER WITH A FEATURE TUESDAY NIGHT THAN OTHER
MODELS...BUT MUCH OF THIS ENERGY CAN BE TRACED BACK TO CONVECTIVE
FEEDBACK IN THE MID WEST. THEREFORE...WILL KEEP POPS LOW AS GFS
WOULD KEEP MOST PRECIPITATION TO OUR NORTHWEST. MODELS ARE FAIRLY
CONSISTENT WITH A COLD FRONT MOVING THROUGH THURSDAY NIGHT.
THEREFORE...WILL RAISE POPS THURSDAY NIGHT...AND REMOVE POPS BEHIND
FRONT FRIDAY AFTERNOON AND EVENING.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
GENERALLY FOLLOWED WPC THINKING WITH THE EXTENDED PORTION OF THE
FORECAST...WITH A LEANING TOWARDS THE EC/CMC PER ENSEMBLE SUPPORT.
UPPER RIDGE AXIS OVER THE FORECAST AREA AT THE OUTSET OF THE PERIOD
WILL QUICKLY PUSH OFF TO THE EAST WITH A POTENT SYSTEM PUSHING OUT
OF THE CENTRAL ROCKIES TOWARDS THE UPPER MIDWEST...AND SFC COLD
FRONT MARCHING EASTWARD ACROSS THE MISS VALLEY. BASED ON THE SLOWER
PROGRESSION OF NWP CONSENSUS...LOOKS LIKE THURSDAY WILL BE WARM WITH
THE BULK OF THE PRECIP HOLDING OFF UNTIL THURSDAY NIGHT AND FRIDAY
MORNING WITH THE COLD FRONT. PRECIP EXITS TO THE EAST FRIDAY
AFTERNOON...BUT SW FLOW ALOFT CONTINUES OVER THE AREA AS UPPER
TROUGH CONTINUES TO DIG ACROSS THE GREAT LAKES AND OHIO RIVER
VALLEY. AS THE TROUGH MOVES OVERHEAD SATURDAY...WILL CONTINUE SLIGHT
CHANCE POPS MAINLY ACROSS THE NORTHERN ZONES AND EASTERN MOUNTAINS.
FLOW TURNS NORTHWEST BEHIND THE TROUGH AXIS ON SUNDAY YET WITH SOME
LLVL MOISTURE TRAPPED...WILL KEEP THE SLIGHT CHANCE POPS IN ROUGHLY
THE SAME LOCATIONS AS SATURDAY. TEMPERATURES WILL BE PROGRESSIVELY
COOLER WITH EACH PASSING DAY THROUGH THE EXTENDED...DROPPING FROM
THE LOWER 70S LOWLANDS ON THURSDAY TO AROUND THE 50 DEGREE MARK BY
SUNDAY FOR THE LOWLANDS.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
FEW TO SCT 4 TO 5 THSD FT CLDS INTO MORNING HRS ALONG AND N OF I64
CORRIDOR. ACROSS THE S...HAVE OVC CONDITIONS SPREADING N THRU SW
VA INTO S WV THIS MORNING. THINK MUCH OF THESE REMAIN LOW END
VFR...SAVE FOR SOME MVFR CIGS FOR S MTNS INCLUDING KBKW. HAVE SOME
PREDAWN VLIFR RVR VALLEY FG FOR KPKB LIFTING BY 14Z.
UPR LVL SYS RESPONSIBLE FOR INCREASE IN CLDS WILL PASS S OF AREA
TDY. HOWEVER SCT SHRA EXPECTED FOR SW VA AND SE WV. KEPT MVFR
CIGS GOING TDY FOR KBKW BUT PCPN FREE. TOUGH TO SAY WHETHER OVC
REACHES KHTS TO KCRW TDY BUT DID INSERT BKN LOW END VFR CLDS IN
FOR TDY. JUST HAVE SOME CIRRUS SE OH/N WV FOR TDY.
UPR LVL SYS PASSES E OF AREA THIS AFTN...TAKING SHRA THREAT WITH
IT. HOWEVER ABUNDANT LLVL MOISTURE WILL REMAIN ACROSS SW VA AND S
WV TONIGHT WHICH MAY HOLD IN MVFR CIGS FOR KBKW. OTHERWISE JUST
SOME PASSING CIRRUS SE OH/N WV WHERE SOME LATE LIFR/IFR RVR FG MAY
BE REALIZED.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATIVE SCENARIOS: OVC DECK MAY MAKE IT INTO KHTS/KCRW FOR
TDY...BUT STILL WOULD REMAIN VFR.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H M M M M
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY M H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z TUESDAY...
IFR OR WORSE IN RVR VALLEY FG POSSIBLE TUES MORNING ACROSS SE OH/N
WV. IFR POSSIBLE IN SHOWERS THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/JMV/50/30
NEAR TERM...JMV/30
SHORT TERM...RPY
LONG TERM...ARJ
AVIATION...30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
641 AM EDT MON OCT 28 2013
.SYNOPSIS...
LOW PRESSURE PASSES SOUTH OF THE AREA TODAY. A WARM FRONT MOVES
NORTHWARD TUESDAY NIGHT AND WEDNESDAY...BRINGING MILDER AIR. STRONG
COLD FRONT WITH SHOWERS THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
630 AM UPDATE...
HAD TO NUDGE THE N EDGE OF CLD SHIELD UP THIS MORNING TO INCLUDE
HTS TO CRW CORRIDOR...PERHAPS EVEN N OF THERE PER LATEST RUC.
OTHERWISE...NO MAJOR CHANGES. STILL LOOKING FOR SHRA ACROSS SW VA
AND SE WV TDY.
PREVIOUS DISCUSSION BELOW...
NOT MUCH CHANGE IN FCST THINKING FROM DAY SHIFT. DID ELECT TO BUMP
UP POPS ACROSS SW VA INTO LKLY MID TO LATE MORNING PER LATEST MDL
RUNS. TIGHT POP GRADIENT WITH CHC GETTING INTO COAL FIELDS TO SE
WV...WITH NOTHING N OF THERE. ALSO LOOKING AT A TIGHT GRADIENT TO
SKY GRIDS AS WELL. WENT WITH SOLID OVC ACROSS SW VA AND S WV TDY.
HARD TO SAY IF OVC REACHES AS FAR N AT HTS TO CRW CORRIDOR. DID
ALLOW FOR BKN COVERAGE THOUGH WITH CIRRUS ACROSS SE OH AND N WV.
UPR LVL DISTURBANCE RESPONSIBLE FOR WX TDY SHIFT E OF CWA THIS
AFTN AND BEGIN TO QUICKLY RAMP DOWN POPS THIS AFTN ACROSS S ZONES.
ABUNDANCE OF LLVL MOISTURE WILL LINGER THOUGH THROUGH THIS AFTN
AND A GOOD CHUNK OF THE NIGHT ACROSS S WV/SW VA...THUS KEPT
PESSIMISTIC SKY COVERAGE ACROSS THOSE LOCALES WITH SOME CIRRUS
ELSEWHERE.
INGESTED LATEST HRRR AS A BASE FOR TEMPS TDY AND
TONIGHT...TWEAKING S ZONES FOR COOLER WX PER CLDS/SHRA THREAT.
TRIED TO GO TOWARD WARMER MET ACROSS SE OH AND N WV WHERE AT LEAST
FILTERED SUN WILL BE REALIZED. SAME GENERAL THINKING HOLDS TONIGHT
AS WELL...WITH WARMER READINGS ACROSS SW VA AND S WV...WITH COOLER
READINGS FOR SE OH AND N WV.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
NAM IS MUCH STRONGER WITH A FEATURE TUESDAY NIGHT THAN OTHER
MODELS...BUT MUCH OF THIS ENERGY CAN BE TRACED BACK TO CONVECTIVE
FEEDBACK IN THE MID WEST. THEREFORE...WILL KEEP POPS LOW AS GFS
WOULD KEEP MOST PRECIPITATION TO OUR NORTHWEST. MODELS ARE FAIRLY
CONSISTENT WITH A COLD FRONT MOVING THROUGH THURSDAY NIGHT.
THEREFORE...WILL RAISE POPS THURSDAY NIGHT...AND REMOVE POPS BEHIND
FRONT FRIDAY AFTERNOON AND EVENING.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
GENERALLY FOLLOWED WPC THINKING WITH THE EXTENDED PORTION OF THE
FORECAST...WITH A LEANING TOWARDS THE EC/CMC PER ENSEMBLE SUPPORT.
UPPER RIDGE AXIS OVER THE FORECAST AREA AT THE OUTSET OF THE PERIOD
WILL QUICKLY PUSH OFF TO THE EAST WITH A POTENT SYSTEM PUSHING OUT
OF THE CENTRAL ROCKIES TOWARDS THE UPPER MIDWEST...AND SFC COLD
FRONT MARCHING EASTWARD ACROSS THE MISS VALLEY. BASED ON THE SLOWER
PROGRESSION OF NWP CONSENSUS...LOOKS LIKE THURSDAY WILL BE WARM WITH
THE BULK OF THE PRECIP HOLDING OFF UNTIL THURSDAY NIGHT AND FRIDAY
MORNING WITH THE COLD FRONT. PRECIP EXITS TO THE EAST FRIDAY
AFTERNOON...BUT SW FLOW ALOFT CONTINUES OVER THE AREA AS UPPER
TROUGH CONTINUES TO DIG ACROSS THE GREAT LAKES AND OHIO RIVER
VALLEY. AS THE TROUGH MOVES OVERHEAD SATURDAY...WILL CONTINUE SLIGHT
CHANCE POPS MAINLY ACROSS THE NORTHERN ZONES AND EASTERN MOUNTAINS.
FLOW TURNS NORTHWEST BEHIND THE TROUGH AXIS ON SUNDAY YET WITH SOME
LLVL MOISTURE TRAPPED...WILL KEEP THE SLIGHT CHANCE POPS IN ROUGHLY
THE SAME LOCATIONS AS SATURDAY. TEMPERATURES WILL BE PROGRESSIVELY
COOLER WITH EACH PASSING DAY THROUGH THE EXTENDED...DROPPING FROM
THE LOWER 70S LOWLANDS ON THURSDAY TO AROUND THE 50 DEGREE MARK BY
SUNDAY FOR THE LOWLANDS.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
FEW TO SCT 4 TO 5 THSD FT CLDS INTO MORNING HRS ALONG AND N OF I64
CORRIDOR. ACROSS THE S...HAVE OVC CONDITIONS SPREADING N THRU SW
VA INTO S WV THIS MORNING. THINK MUCH OF THESE REMAIN LOW END
VFR...SAVE FOR SOME MVFR CIGS FOR S MTNS INCLUDING KBKW. HAVE SOME
PREDAWN VLIFR RVR VALLEY FG FOR KPKB LIFTING BY 14Z.
UPR LVL SYS RESPONSIBLE FOR INCREASE IN CLDS WILL PASS S OF AREA
TDY. HOWEVER SCT SHRA EXPECTED FOR SW VA AND SE WV. KEPT MVFR
CIGS GOING TDY FOR KBKW BUT PCPN FREE. TOUGH TO SAY WHETHER OVC
REACHES KHTS TO KCRW TDY BUT DID INSERT BKN LOW END VFR CLDS IN
FOR TDY. JUST HAVE SOME CIRRUS SE OH/N WV FOR TDY.
UPR LVL SYS PASSES E OF AREA THIS AFTN...TAKING SHRA THREAT WITH
IT. HOWEVER ABUNDANT LLVL MOISTURE WILL REMAIN ACROSS SW VA AND S
WV TONIGHT WHICH MAY HOLD IN MVFR CIGS FOR KBKW. OTHERWISE JUST
SOME PASSING CIRRUS SE OH/N WV WHERE SOME LATE LIFR/IFR RVR FG MAY
BE REALIZED.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATIVE SCENARIOS: OVC DECK MAY MAKE IT INTO KHTS/KCRW FOR
TDY...BUT STILL WOULD REMAIN VFR.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H M
EKN CONSISTENCY M M H H H H H H H H H H
PKB CONSISTENCY L M L L H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z TUESDAY...
IFR OR WORSE IN RVR VALLEY FG POSSIBLE TUES MORNING ACROSS SE OH/N
WV. IFR POSSIBLE IN SHOWERS THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/50/30
NEAR TERM...30
SHORT TERM...RPY
LONG TERM...ARJ
AVIATION...30
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1002 AM EDT MON OCT 28 2013
.SYNOPSIS...
A COLD FRONT EXTENDED ACROSS THE GREAT LAKES TO A LOW IN
THE CENTRAL ROCKIES THIS MORNING...WHILE WEAK HIGH PRESSURE WAS OVER
THE SOUTHEAST UNITED STATES. THE FRONT WILL MOVE SOUTHEAST AND
DISSIPATE TODAY AND TONIGHT. TUESDAY AND WEDNESDAY THE LOW WILL MOVE
FROM THE CENTRAL PLAINS INTO THE WESTERN GREAT LAKES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 AM EDT MONDAY...
THIS MORNING KFCX 88D SHOWED LIGHT RETURNS MOVING EAST ACROSS THE
SCOPE. THE 12Z/8AM RNK SOUNDING INDICATED SHALLOW MOISTURE UP TO
775 MB WITH A WEST TO NORTHWEST FLOW AND PWAT AT 0.55 INCHES.
ADJUSTED TEMPERATURES AND DEW POINTS WITH LATEST OBS AND MODEL
TRENDS. SHAPED POP AND WEATHER WITH LATEST RADAR AND MODEL TREND.
LEANED POPS TOWARDS THE RNK WRF ARW FOR LATE THIS MORNING INTO
AFTERNOON.
AS OF 515 AM EDT MONDAY...
A WEAK STATIONARY BOUNDARY AT THE SURFACE WAS OVER THE TENNESSEE
VALLEY AND WAS THE LEADING EDGE OF WARMER AIR AND HIGHER DEW POINTS.
WATER VAPOR LOOP SHOWED AN UPPER LOW IN NORTHEAST MISSISSIPPI. THIS
LOW WILL MOVE EAST INTO THE CAROLINAS BY LATE TONIGHT.
AS SURFACE DEW POINTS RISE INTO THE 40S AND 50S AND THE AIR MASS
SATURATES...THE PROBABILITY OF PRECIPITATION GOES UP BUT AMOUNTS WILL
REMAIN LIGHT. HAVE INCREASED PROBABILITY OF PRECIPITATION IN THE
SOUTHWEST COUNTIES OF THE FORECAST AREA WHERE MOST OF THE GUIDANCE
IS SHOWING SOME RAIN FOR TODAY BUT HAVE DELAYED THE START TIME.
LOCAL WRF AND RAP GUIDANCE HAVE THE BEST CHANCE OF RAIN MOVING INTO
THE COUNTY WARNING AREA AFTER 13Z/9AM.
CLOUDS WILL ADVANCE INTO THE AREA AHEAD OF THE RAIN. SATELLITE
PICTURES SHOWED LEADING EDGE ALREADY UP TO A BLUEFIELD TO DANVILLE
LINE. WITH CLOUD COVER EXPECTED MUCH OF THE DAY IN THIS SOUTHWEST
PART OF THE FORECAST AREA...HAVE GONE A COUPLE OF DEGREES BELOW
GUIDANCE FOR MAXIMUM TEMPERATURES. USED A BLEND OF BIAS CORRECTED
MAV/MET GUIDANCE FOR OVERNIGHT LOWS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM EDT MONDAY...
UPPER LEVEL RIDGING ACROSS THE EASTERN HALF OF THE NATION WILL
RESULT IN UNSEASONABLY WARM TEMPERATURES FOR THE MIDDLE OF THE
WORKWEEK. WILL START TUESDAY OFF WITH A WEAK COLD FRONT SINKING
SOUTHWARD ACROSS OUR AREA...WHILE HIGH PRESSURE BUILDS IN BEHIND...
HUGGING THE EASTERN FACE OF THE APPALACHIANS. NORTHEASTERLY WINDS
AROUND THE HIGH WILL CARRY COOLER AIR FROM THE ATLANTIC...AND
THEREFORE HAVE UNDERCUT MODEL GUIDANCE A COUPLE OF DEGREES FOR
AFTERNOON HIGHS. ALSO KEPT A SLIGHT CHANCE OF SHOWERS IN THE
FORECAST FOR THE MORNING AND AFTERNOON AS THE FRONT STALLS JUST
SOUTH OF OUR AREA...BUT BELIEVE THIS ACTIVITY WILL REMAIN ISOLATED
AND MAINLY IN THE FORM OF SPRINKLES WHERE IT DOES OCCUR.
WINDS WILL QUICKLY SHIFT SOUTHWESTERLY TUESDAY NIGHT AS HIGH
PRESSURE SLIDES OFFSHORE...AND A DEEP LOW PRESSURE SYSTEM DEVELOPS
OVER THE CENTRAL PLAINS. THE STALLED FRONT WILL LIFT BACK TO THE
NORTH AS A WARM FRONT WEST OF THE APPALACHIANS...BUT WILL BE SLOWER
TO LIFT NEAR OUR AREA...AND WILL THEREFORE PROVIDE THE FOCUS OF MORE
SPOTTY SHOWER ACTIVITY. BELIEVE THESE SHOWERS WILL OCCUR IN WAVES AS
WEAK UPPER LEVEL DISTURBANCES RIDE ALONG THE FRONT FROM THE WEST...
WITH BETTER RAIN CHANCES FOUND NORTH OF INTERSTATE 81. THE WARM
FRONT WILL FINALLY LIFT NORTH OF OUR AREA WEDNESDAY EVENING...
BRINGING A LULL IN THE SHOWER ACTIVITY AS THE LOW PRESSURE SYSTEM
APPROACHES THE GREAT LAKES...DRAGGING A STRONG COLD FRONT ACROSS THE
PLAINS.
SHOWER ACTIVITY WILL INCREASE ON THURSDAY AFTERNOON AND EVENING AS
THE COLD FRONT MOVES EAST OF THE MISSISSIPPI RIVER...BUT BELIEVE THE
HEAVIEST AND MOST WIDESPREAD RAIN WILL OCCUR AFTER MIDNIGHT EARLY
FRIDAY MORNING AS THE SUPPORTING UPPER LEVEL TROUGH MOVES ACROSS THE
AREA. MOST MODELS ARE IN GOOD AGREEMENT WITH TIMING OF THE FRONT...
AND THERE HAS BEEN GOOD MODEL RUN TO RUN CONSISTENCY OVER THE PAST
DAY...SO FEEL COMFORTABLE GOING WITH HIGH RAIN CHANCES FOR EARLY
FRIDAY. WHILE CAPE IS MINIMAL...MODELS AGREE THAT THE 50+ KT LOW
LEVEL JET WILL SUPPORT HIGH SHEAR AND HELICITY VALUES ACROSS OUR
AREA...MEANING THAT WHILE WE MAY NOT OBSERVE MUCH LIGHTNING IN THE
CONVECTION...THE HEAVIER SHOWERS MAY PULL SOME OF THE STRONGER WINDS
ALOFT DOWN TO THE SURFACE...RESULTING IN GUSTY AND LOCALLY DAMAGING
WINDS. THE HIGH SHEAR AND HELICITY ALSO MEANS WE CANNOT RULE OUT AN
ISOLATED SPIN UP TORNADO.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 400 AM EDT MONDAY...
THE COLD FRONT WILL SLIDE EAST ACROSS THE AREA FRIDAY AFTERNOON AND
REACH THE ATLANTIC COAST FRIDAY NIGHT INTO SATURDAY MORNING. LEANED
ISC GRIDS TOWARDS THE SLOWER ECMWF WITH COLD FRONT OVER THE QUICKER
GFS SOLUTION. IN THE WAKE OF THE COLD FRONT...HIGH PRESSURE WILL
BUILD EAST ACROSS OUR REGION SATURDAY. BY SATURDAY NIGHT THE
COMBINATION OF NORTHWEST FLOW AND A SHORTWAVE WILL CREATE UPSLOPE
RAIN AND SNOW SHOWERS ACROSS THE FAVORED UPSLOPE REGION IN THE WEST.
HIGH PRESSURE BUILDS EAST INTO THE REGION SUNDAY...ENDING ANY
UPSLOPE PRECIPITATION IN THE WEST. COOLING TREND EXPECTED IN THE
TEMPERATURES FOR THE WEEKEND AS UPPER TROUGH SLIDE ACROSS EAST COAST.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
AS OF 135 AM EDT MONDAY...
NORTHEAST EDGE OF SCATTERED PRECIPITATION ASSOCIATED WITH AN
UPPER LOW OVER NORTHEAST MISSISSIPPI WAS ADVANCING EAST INTO
VIRGINIA AND THE CAROLINAS. CEILINGS HAD DROPPED TO MVFR IN
PARTS OF SOUTHWEST VIRGINIA AND SOUTHERN WEST VIRGINIA.
MODELS TRACK THE UPPER LOW EAST INTO THE CAROLINAS TODAY AND
TONIGHT. GUIDANCE KEPT CEILINGS VFR AT KBCB/KROA AND KDAN BUT
THESE SITES MAY POSSIBLY HAVE MVFR CEILINGS BEFORE 18Z/2PM.
CONFIDENCE IS MODERATE. FARTHER NORTH KLWB AND KLYH WILL REMAIN
VFR TODAY.
THE UPPER LOW WILL BE EAST OF THE FORECAST AREA TONIGHT. CLOUDS
WILL GRADUALLY CLEAR BY TUESDAY MORNING. THERE MAY BE FOG AT KLWB
OVERNIGHT DEPENDING ON HOW FAST IT CLEARS...SO FOR NOW ONLY
INCLUDED MVFR FOG. NO VISIBILITY RESTRICTION ARE EXPECTED WITH
THE SHOWERS TODAY.
MAINLY VFR CONDITIONS ARE EXPECTED TUESDAY THROUGH THURSDAY IN
ADVANCE OF AN APPROACHING COLD FRONT. LOW LEVEL SOUTH WINDS WILL
BE STEADILY INCREASING DURING THIS PERIOD.
MODEL GUIDANCE VARIES AS TO THE TIMING OF THE PASSAGE OF A COLD
FRONT. CURRENTLY LOOKING AT SOMETIME ON THURSDAY NIGHT TO FRIDAY.
THE PASSAGE OF THE FRONT WILL BRING SUB-VFR CONDITIONS ALONG AND
AHEAD OF THE BOUNDARY WITH SHOWERS AND GUSTY WINDS.
IN THE WAKE OF THE COLD FRONT...LOOK FOR INCREASING NORTHWEST FLOW
BEHIND THE SURFACE SYSTEM. THIS SCENARIO WILL LIKELY PLACE
UPSLOPE RAIN/SNOW SHOWERS ACROSS THE PREFERRED UPSLOPE REGIONS OF
SOUTHEAST WEST VIRGINIA SATURDAY INTO SUNDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/KK
SHORT TERM...NF
LONG TERM...KK
AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
746 AM EDT MON OCT 28 2013
.SYNOPSIS...
A COLD FRONT EXTENDED ACROSS THE GREAT LAKES TO A LOW IN
THE CENTRAL ROCKIES THIS MORNING...WHILE WEAK HIGH PRESSURE WAS OVER
THE SOUTHEAST UNITED STATES. THE FRONT WILL MOVE SOUTHEAST AND
DISSIPATE TODAY AND TONIGHT. TUESDAY AND WEDNESDAY THE LOW WILL MOVE
FROM THE CENTRAL PLAINS INTO THE WESTERN GREAT LAKES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 515 AM EDT MONDAY...
A WEAK STATIONARY BOUNDARY AT THE SURFACE WAS OVER THE TENNESSEE
VALLEY AND WAS THE LEADING EDGE OF WARMER AIR AND HIGHER DEW POINTS.
WATER VAPOR LOOP SHOWED AN UPPER LOW IN NORTHEAST MISSISSIPPI. THIS
LOW WILL MOVE EAST INTO THE CAROLINAS BY LATE TONIGHT.
AS SURFACE DEW POINTS RISE INTO THE 40S AND 50S AND THE AIR MASS
SATURATES...THE PROBABILITY OF PRECIPITATION GOES UP BUT AMOUNTS WILL
REMAIN LIGHT. HAVE INCREASED PROBABILITY OF PRECIPITATION IN THE
SOUTHWEST COUNTIES OF THE FORECAST AREA WHERE MOST OF THE GUIDANCE
IS SHOWING SOME RAIN FOR TODAY BUT HAVE DELAYED THE START TIME.
LOCAL WRF AND RAP GUIDANCE HAVE THE BEST CHANCE OF RAIN MOVING INTO
THE COUNTY WARNING AREA AFTER 13Z/9AM.
CLOUDS WILL ADVANCE INTO THE AREA AHEAD OF THE RAIN. SATELLITE
PICTURES SHOWED LEADING EDGE ALREADY UP TO A BLUEFIELD TO DANVILLE
LINE. WITH CLOUD COVER EXPECTED MUCH OF THE DAY IN THIS SOUTHWEST
PART OF THE FORECAST AREA...HAVE GONE A COUPLE OF DEGREES BELOW
GUIDANCE FOR MAXIMUM TEMPERATURES. USED A BLEND OF BIAS CORRECTED
MAV/MET GUIDANCE FOR OVERNIGHT LOWS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM EDT MONDAY...
UPPER LEVEL RIDGING ACROSS THE EASTERN HALF OF THE NATION WILL
RESULT IN UNSEASONABLY WARM TEMPERATURES FOR THE MIDDLE OF THE
WORKWEEK. WILL START TUESDAY OFF WITH A WEAK COLD FRONT SINKING
SOUTHWARD ACROSS OUR AREA...WHILE HIGH PRESSURE BUILDS IN BEHIND...
HUGGING THE EASTERN FACE OF THE APPALACHIANS. NORTHEASTERLY WINDS
AROUND THE HIGH WILL CARRY COOLER AIR FROM THE ATLANTIC...AND
THEREFORE HAVE UNDERCUT MODEL GUIDANCE A COUPLE OF DEGREES FOR
AFTERNOON HIGHS. ALSO KEPT A SLIGHT CHANCE OF SHOWERS IN THE
FORECAST FOR THE MORNING AND AFTERNOON AS THE FRONT STALLS JUST
SOUTH OF OUR AREA...BUT BELIEVE THIS ACTIVITY WILL REMAIN ISOLATED
AND MAINLY IN THE FORM OF SPRINKLES WHERE IT DOES OCCUR.
WINDS WILL QUICKLY SHIFT SOUTHWESTERLY TUESDAY NIGHT AS HIGH
PRESSURE SLIDES OFFSHORE...AND A DEEP LOW PRESSURE SYSTEM DEVELOPS
OVER THE CENTRAL PLAINS. THE STALLED FRONT WILL LIFT BACK TO THE
NORTH AS A WARM FRONT WEST OF THE APPALACHIANS...BUT WILL BE SLOWER
TO LIFT NEAR OUR AREA...AND WILL THEREFORE PROVIDE THE FOCUS OF MORE
SPOTTY SHOWER ACTIVITY. BELIEVE THESE SHOWERS WILL OCCUR IN WAVES AS
WEAK UPPER LEVEL DISTURBANCES RIDE ALONG THE FRONT FROM THE WEST...
WITH BETTER RAIN CHANCES FOUND NORTH OF INTERSTATE 81. THE WARM
FRONT WILL FINALLY LIFT NORTH OF OUR AREA WEDNESDAY EVENING...
BRINGING A LULL IN THE SHOWER ACTIVITY AS THE LOW PRESSURE SYSTEM
APPROACHES THE GREAT LAKES...DRAGGING A STRONG COLD FRONT ACROSS THE
PLAINS.
SHOWER ACTIVITY WILL INCREASE ON THURSDAY AFTERNOON AND EVENING AS
THE COLD FRONT MOVES EAST OF THE MISSISSIPPI RIVER...BUT BELIEVE THE
HEAVIEST AND MOST WIDESPREAD RAIN WILL OCCUR AFTER MIDNIGHT EARLY
FRIDAY MORNING AS THE SUPPORTING UPPER LEVEL TROUGH MOVES ACROSS THE
AREA. MOST MODELS ARE IN GOOD AGREEMENT WITH TIMING OF THE FRONT...
AND THERE HAS BEEN GOOD MODEL RUN TO RUN CONSISTENCY OVER THE PAST
DAY...SO FEEL COMFORTABLE GOING WITH HIGH RAIN CHANCES FOR EARLY
FRIDAY. WHILE CAPE IS MINIMAL...MODELS AGREE THAT THE 50+ KT LOW
LEVEL JET WILL SUPPORT HIGH SHEAR AND HELICITY VALUES ACROSS OUR
AREA...MEANING THAT WHILE WE MAY NOT OBSERVE MUCH LIGHTNING IN THE
CONVECTION...THE HEAVIER SHOWERS MAY PULL SOME OF THE STRONGER WINDS
ALOFT DOWN TO THE SURFACE...RESULTING IN GUSTY AND LOCALLY DAMAGING
WINDS. THE HIGH SHEAR AND HELICITY ALSO MEANS WE CANNOT RULE OUT AN
ISOLATED SPIN UP TORNADO.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 400 AM EDT MONDAY...
THE COLD FRONT WILL SLIDE EAST ACROSS THE AREA FRIDAY AFTERNOON AND
REACH THE ATLANTIC COAST FRIDAY NIGHT INTO SATURDAY MORNING. LEANED
ISC GRIDS TOWARDS THE SLOWER ECMWF WITH COLD FRONT OVER THE QUICKER
GFS SOLUTION. IN THE WAKE OF THE COLD FRONT...HIGH PRESSURE WILL
BUILD EAST ACROSS OUR REGION SATURDAY. BY SATURDAY NIGHT THE
COMBINATION OF NORTHWEST FLOW AND A SHORTWAVE WILL CREATE UPSLOPE
RAIN AND SNOW SHOWERS ACROSS THE FAVORED UPSLOPE REGION IN THE WEST.
HIGH PRESSURE BUILDS EAST INTO THE REGION SUNDAY...ENDING ANY
UPSLOPE PRECIPITATION IN THE WEST. COOLING TREND EXPECTED IN THE
TEMPERATURES FOR THE WEEKEND AS UPPER TROUGH SLIDE ACROSS EAST COAST.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 135 AM EDT MONDAY...
NORTHEAST EDGE OF SCATTERED PRECIPITATION ASSOCIATED WITH AN
UPPER LOW OVER NORTHEAST MISSISSIPPI WAS ADVANCING EAST INTO
VIRGINIA AND THE CAROLINAS. CEILINGS HAD DROPPED TO MVFR IN
PARTS OF SOUTHWEST VIRGINIA AND SOUTHERN WEST VIRGINIA.
MODELS TRACK THE UPPER LOW EAST INTO THE CAROLINAS TODAY AND
TONIGHT. GUIDANCE KEPT CEILINGS VFR AT KBCB/KROA AND KDAN BUT
THESE SITES MAY POSSIBLY HAVE MVFR CEILINGS BEFORE 18Z/2PM.
CONFIDENCE IS MODERATE. FARTHER NORTH KLWB AND KLYH WILL REMAIN
VFR TODAY.
THE UPPER LOW WILL BE EAST OF THE FORECAST AREA TONIGHT. CLOUDS
WILL GRADUALLY CLEAR BY TUESDAY MORNING. THERE MAY BE FOG AT KLWB
OVERNIGHT DEPENDING ON HOW FAST IT CLEARS...SO FOR NOW ONLY
INCLUDED MVFR FOG. NO VISIBILITY RESTRICTION ARE EXPECTED WITH
THE SHOWERS TODAY.
MAINLY VFR CONDITIONS ARE EXPECTED TUESDAY THROUGH THURSDAY IN
ADVANCE OF AN APPROACHING COLD FRONT. LOW LEVEL SOUTH WINDS WILL
BE STEADILY INCREASING DURING THIS PERIOD.
MODEL GUIDANCE VARIES AS TO THE TIMING OF THE PASSAGE OF A COLD
FRONT. CURRENTLY LOOKING AT SOMETIME ON THURSDAY NIGHT TO FRIDAY.
THE PASSAGE OF THE FRONT WILL BRING SUB-VFR CONDITIONS ALONG AND
AHEAD OF THE BOUNDARY WITH SHOWERS AND GUSTY WINDS.
IN THE WAKE OF THE COLD FRONT...LOOK FOR INCREASING NORTHWEST FLOW
BEHIND THE SURFACE SYSTEM. THIS SCENARIO WILL LIKELY PLACE
UPSLOPE RAIN/SNOW SHOWERS ACROSS THE PREFERRED UPSLOPE REGIONS OF
SOUTHEAST WEST VIRGINIA SATURDAY INTO SUNDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...NF
LONG TERM...KK
AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS PUEBLO CO
340 PM MDT MON OCT 28 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 337 PM MDT MON OCT 28 2013
COOL FRONT HAS SLIPPED DOWN TO THE CO/NM BORDER WITH THE BOUNDARY
JUST N OF THE STATE LINE. NE COLO WAS SOCKED IN WITH LOW CLOUDS AND
THESE CLOUDS WERE JUST MAKING IT INTO EXTREME N AND NE EL PASO COUNTY.
A COUPLE OF WELL DEFINED WIND SHIFT LINES WERE NOTED OVER S EL PASO
AND N PUEBLO COUNTIES. THESE BOUNDARIES WERE ASSOCIATED WITH WIND
SHIFT LINES (NE WINDS VS SE WINDS).
ELSEWHERE...A STRONG UPPER LOW WAS NOTED OVER NEVADA AND WAS MOVING
SLOWLY EAST. QUITE A BIT OF DRY AIR IN THE UPPER LEVELS WAS NOTED IN
ADVANCE OF THIS SYSTEM PER WATER VAP IMGY.
REST OF TODAY INTO TONIGHT...
FIRST CONCERN WILL BE THUNDER. SIMULATIONS CONTINUE TO SHOW TSRA
BREAKING OUT ALONG THE CO/KS BORDER EARLY THIS EVENING. FOR THIS
REASON KEPT VERY SLIGHT POPS ALONG THE BORDER FOR THIS EVENING. I AM
HIGHLY CONFIDENT CONVECTION WILL OCCUR...BUT DO NOT KNOW WHICH SIDE
OF THE BORDER IT WILL INITIATE ON. SPC HAS THE AREA OUTLOOKED WITH A
5% CHANCE OF SVR (HAIL).
2ND CONCERN IS LOW CLOUDS/FOG TONIGHT. VERY CONFIDENT LOW CLOUDS WILL
BE OVER MOST OF THE PLAINS TONIGHT...HOWEVER CONFIDENCE IS NOT TOO
HIGH ON HOW FAR WEST THESE CLOUDS WILL MAKE IT BACK TOWARDS THE
MTNS. LATEST HRRR HAS BECOME A BIT MORE AGGRESSIVE MOVING THE CLOUDS
ALL THE WAY BACK TO THE MTNS. CONCEPTUALLY...THIS LOOKS REALISTIC
AND WILL LIKELY ADD MORE CLOUDS INTO THE NDFD.
OVER THE CONTDVD...MSTR WILL SLOWLY INCREASE TONIGHT...BUT EXPECT
MAINLY SNOW SHOWERS...ESPECIALLY THE SAN JUANS...WITH INSIGNIFICANT
ACCUMS.
SOME FREEZING FOG WILL BE POSSIBLE TONIGHT OVER EL PASO COUNTY.
TUESDAY...
UPPER LOW WILL MOVE CLOSER TO THE REGION AND FLOW ALOFT WILL
INTENSIFY. SFC BOUNDARY ALONG THE CO/NM BORDER WILL LIKELY PUSH
NORTH TOMORROW...BUT HOW FAR N IS THE QUESTION. ATTM...I HAVE THE
BOUNDARY RUNNING ROUGHLY FROM KCOS DOWN TO KSPD BY MID AFTERNOON
TOMORROW. LIKEWISE...GUSTY SW WINDS WILL BE LIKELY OVER THE S TIER
FOR THE FCST AREA...AND WE WILL LIKELY MIX OUT ACROSS EL PASO SO
COULD SEE SOME GUSTY WARM WINDS THIS LOCATION BY MID DAY. IT IS
POSSIBLE KPUB AREA WILL NOT MIX OUT TOMORROW WHILE EL PASO COUNTY
DOES MIX OUT. HIGH TEMPS TOMORROW AT KCOS MAY BE WARMER THAN KPUB.
IF THIS VERIFIES...THEN CURRENT FCST WILL NEED TO BE ADJUSTED BY
LATER SHIFTS.
SNOWS WILL GRADUALLY RAMP UP OVER THE MTNS ALONG THE
CONTDVD...ESPECIALLY LATER TOMORROW AFTERNOON. COULD SEE A COUPLE OF
INCHES OF SNOW...ESPECIALLY ABOVE 10KFT BY LATE TOMORROW AFTERNOON.
IT WILL LIKELY BE WINDY ANY WHERE SOUTH OF THE FRONT...WITH GUSTS TO
25 TO 35 MPH POSSIBLE...AND 40 TO 45 MPH OVER THE HIGHER TRRN.
/HODANISH.
.LONG TERM...(TUESDAY NIGHT THROUGH NEXT MONDAY)
ISSUED AT 337 PM MDT MON OCT 28 2013
UNSETTLED METEOROLOGICAL CONDITIONS ARE ANTICIPATED OVER PORTIONS
OF THE FORECAST DISTRICT FROM TUESDAY NIGHT INTO THURSDAY...ESPECIALLY
OVER THE CENTRAL MOUNTAINS...AS A UPPER SYSTEM IMPACTS THE CWFA
DURING THIS TIME-FRAME. A RETURN TO DRIER AND WARMER CONDITIONS IS
THEN PROJECTED TO RETURN TO THE FORECAST DISTRICT BY THIS WEEKEND.
RECENT LONGER RANGE COMPUTER SIMULATIONS AND FORECAST MODEL
SOUNDINGS SUGGEST THAT DOUBLE-BARRELED CLOSED UPPER LOW INITIALLY
LOCATED OVER NORTHWESTERN WYOMING AND SOUTHERN NEVADA
RESPECTIVELY AT 06Z WEDNESDAY WILL ROTATE INTO AN EASTERN
WYOMING/SOUTHWESTERN COLORADO LOCATION BY 00Z THURSDAY BEFORE
SHIFTING EAST OF THE FORECAST DISTRICT BY 18Z THURSDAY.
THIS SYSTEM WILL BE CAPABLE OF GENERATING SEVERAL INCHES OF
ACCUMULATING SNOW OVER PORTIONS OF THE SOUTHWESTERN AND
ESPECIALLY CENTRAL MOUNTAINS FROM TUESDAY NIGHT INTO THURSDAY
MORNING(I.E. PORTIONS OF PUBLIC ZONES 58/59/60 AND POSSIBLY 66/68
AND 82).
IN ADDITION...EVEN A FEW INCHES OF SNOW WILL BE POSSIBLE OVER
PORTIONS OF EL PASO AND TELLER COUNTIES AS WELL AS POSSIBLY THE
SANGRE DE CRISTO AND WET MOUNTAINS...ESPECIALLY FROM LATER
WEDNESDAY INTO WEDNESDAY NIGHT.
AT THIS TIME IT APPEARS THAT PRIMARILY WINTER WEATHER ADVISORY
SNOW AMOUNTS WILL BE MOST LIKELY WITH THIS EVENT OVER PORTIONS OF
PUBLIC ZONES 58/59/60 AND POSSIBLY 66/68 AND 82 FROM TUESDAY NIGHT
INTO THURSDAY MORNING...ESPECIALLY IF THE 12Z/28TH ECMWF SOLUTION
VERIFIES. ZONE 60 MAY BE THE MOST PRONE TO RECEIVE WINTER STORM
WARNING TOTALS WITH THIS EVENT...ONCE AGAIN IF THE 12Z/28TH ECMWF
IS CORRECT. WFO PUEBLO WILL MONITOR CLOSELY AND ISSUE NEEDED
HIGHLIGHTS AS NEEDED AND AS WE NEAR THIS POTENTIAL EVENT.
GUSTY WINDS(AROUND 50 KNOTS AT TIMES)...PRIMARILY FAVORING HIGHER
TERRAIN LOCATIONS ARE ALSO ANTICIPATED TUESDAY NIGHT AND THEN
AGAIN FROM LATER WEDNESDAY NIGHT INTO THURSDAY NIGHT.
AS TOUCHED UPON BRIEFLY EARLIER...A RETURN TO WARMER AND DRIER
CONDITIONS SHOULD THEN BE EXPERIENCED OVER THE FORECAST DISTRICT
BY THIS WEEKEND AS DRY NORTHWESTERLY TO ZONAL UPPER FLOW DEVELOPS
OVER SOUTHERN COLORADO. FINALLY...WARMEST MAXIMUM TEMPERATURES OF
THE LONGER TERM ARE EXPECTED THIS WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 337 PM MDT MON OCT 28 2013
LATEST HRRR IS MORE AGGRESSIVE WITH CLOUDS MAKING IT BACK TO THE
MTNS. LOW CIGS MAY AFFECT KCOS AND KPUB BY 06Z...AND MAY LAST
THROUGH MID MORNING. WILL MAKE AMENDMENTS TO TAF BEFORE ROUTINE 00Z
ISSUANCE. KALS WILL BE VFR TONIGHT.
IT WILL LIKELY BE WINDY AT ALL TAF SITES TOMORROW WITH GUSTY SW
WINDS. HOWEVER...THERE IS A CHANCE THAT KPUB MAY NOT MIX OUT AND
WINDS MAY REMAIN LIGHT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
136 PM MDT MON OCT 28 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 322 AM MDT MON OCT 28 2013
CURRENTLY...THE UPPER LOW PRES SYSTEM WAS LOCATED OVER NORTHERN
CA/WESTERN NV EARLY MON MORNING...PRODUCING CONSIDERABLE CLOUDINESS
ACROSS THE GREAT BASIN AND INCREASING SW FLOW ALOFT FOR THE 4
CORNERS REGION. INCREASING CLOUD COVER AND WINDS HAS KEPT TEMPS
SOMEWHAT MILD THIS AM FOR THE FORECAST AREA. AS OF 3 AM...30S WERE
BEING REPORTED ACROSS THE HIGH VALLEYS...AND 40S TO AROUND 50 F FOR
THE E PLAINS.
TODAY...OVER THE NEXT 24 HRS...MODELS INDICATE THAT THE UPPER LOW
WILL GRADUALLY SLIDE EAST ACROSS NV AND THE GREAT BASIN. THIS SYSTEM
LOOKS LIKE IT WILL TAKE A SLOWER...MORE NORTHERN TRACK...AND
BENEFICIAL SNOWFALL/PCPN FOR THE CWA LOOKS LIKE IT WILL BE MINIMAL.
THE MAIN CHALLENGE TODAY WILL BE THE EXPECTED COLD FRONT THAT WILL
DROP DOWN THE EASTERN PLAINS AND BACK INTO THE AREA. THE FRONT WILL
DROP SOUTH OF THE PALMER DVD EARLY THIS MORNING AND GRADUALLY BACK
INTO THE EASTERN PLAINS THROUGH MIDDAY. HOWEVER...THIS FRONT WILL
BUTT HEADS WITH INCREASING SW FLOW COMING OFF THE SOUTHERN FRONT
RANGE...SO WHERE THE FRONT STALLS WILL MAKE ALL THE DIFFERENCE WHEN
IT COMES TO REALIZED MAX TEMPS TODAY. CURRENTLY...IT LOOKS LIKE THE
COLDER AIR WILL BE ROUGHLY NORTH OF HIGHWAY 50...WHILE THE SOUTHERN
FOOTHILLS AND ALONG THE NM BORDER MAY WARM INTO THE LOWER 70S.
SHOWER ACTIVITY LOOKS TO BE ISOLATED AT BEST ALONG THE CONTDVD
THROUGH THE DAY...AS WELL AS SOME ACTIVITY ALONG THE FRONTAL
BOUNDARY. THERE IS THE POSSIBILITY OF A THUNDERSTORM OR TWO ALONG
THE FAR EASTERN PLAINS THIS AFTN AND INTO THE EVE...SO INTRODUCED
THAT IN THE POP GRIDS.
TONIGHT...THE STORM SYSTEM WILL CONTINUE THE SLOW PROGRESSION...WITH
PERSISTENT SW FLOW DRIVING MOISTURE INTO THE SW MTS. PCPN CHANCES
WILL INCREASE THIS EVENING FOR THE CONTDVD. AS FOR THE
PLAINS...THERE WILL BE THE LINGERING CHANCE OF A THUNDERSTORM UNTIL
MIDNIGHT ALONG THE CO/KS BORDER. ALSO...AS THE SW SFC WINDS DECOUPLE
THE EASTERLY PUSH OF THE LLVL COLD AIR WILL WIN OUT AND PUSH UP
AGAINST THE E MTS. THIS MAY MAKE FOR A COLD NIGHT ALL ALONG THE I25
CORRIDOR WITH MIN TEMPS IN THE UPPER 20S TO LOWER 30S. MOORE
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 322 AM MDT MON OCT 28 2013
TUE MORNING THE UPR LOW IS FORECAST TO BE CENTERED OVR FAR NERN
NV...WITH SW FLOW ALOFT OVR THE FORECAST AREA. THE NAM SHOWS LITTLE
IN THE WAY OF PCPN OVR THE CONTDVD...WHILE THE GFS HAS INCREASING
POPS IN THE MORNING HOURS. AT THE SFC OVR PORTIONS OF THE SERN
PLAINS...STRATUS IS EXPECTED THRU ABOUT MIDMORNING...MAINLY NORTH OF
HIGHWAY 50 AND FROM PUEBLO EASTWARD. IT IS POSSIBLE THAT SOME LIGHT
DRIZZLE COULD OCCUR IN AREAS COVERED BY THE STRATUS. TUE AFTERNOON
THE NAM SHOWS AN ELONGATED UPR LOW FROM SERN ID TO EAST CENTRAL
NV...WHILE THE GFS MOVES THE UPR LOW CENTER INTO FAR WRN WY. IT
STILL LOOKS LIKE THE ONLY AREA THAT WL SEE PCPN IN THE AFTERNOON HRS
IS THE CONTDVD...ALTHOUGH WL LEAVE SOME ISOLD POPS OVR THE ERN MTS.
THE GFS CONTINUES TO SHOWER HYR PCPN AMOUNTS ALONG THE CONTDVD THAN
THE NAM. HIGH TEMPS TUE OVR THE SERN PLAINS WL BE A BIT CHALLENGING
AS THEY ARE DEPENDENT ON WHERE THE SFC BOUNDARY WL LIE. IT DOES
LOOK LIKE LAS ANIMAS COUNTY AND THE SERN FOOTHILLS AND POSSIBLY BACA
COUNTY WL HAVE BREEZY S TO SW WINDS AND WARMER TEMPS THAN THE REST
OF THE SERN PLAINS. THE MTS AND SAN LUIS VALLEY WILL ALSO HAVE SOME
WINDY CONDITIONS. AT THIS TIME...HUMIDITIES LOOK TOO HIGH TO WORRY
ABOUT FIRE WEATHER HIGHLIGHTS...ALTHOUGH DEPENDING ON HOW WARM IT
GETS ON TUE...CONDITIONS MAY BRIEFLY REACH RED FLAG CRITERIA OVR THE
SRN I-25 CORRIDOR IN LAS ANIMAS COUNTY IN THE AFTERNOON.
TUE NIGHT THE UPR LOW CENTER IS EXPECTED TO SHIFT EAST
NORTHEASTWARD. WL CONTINUE BEST PCPN CHANCES ALONG THE
CONTDVD...WITH LITTLE ELSEWHERE. ONCE AGAIN A LOW STRATUS DECK IS
EXPECTED MAINLY FROM THE LOWER ARKANSAS RIVER VALLEY COUNTIES AND
NORTHWARD. THERE MAY BE A BETTER CHANCE FOR SOME LIGHT DRIZZLE
ASSOCIATED WITH THE LOW CLOUDS LATE TUE NIGHT AND EARLY WED MORNING.
WED THE MODELS MOVE THE UPR LOW CENTER INTO SD...AND THEN KEEP IT
MOVING EASTWARD THRU WED NIGHT. THIS WL DRAG THE UPR TROF ACRS THE
FORECAST AREA. MUCH OF THE AREA STILL LOOKS MAINLY DRY...WITH THE
EXCEPTION OF THE CONTDVD ON WED. IT ALSO STILL LOOKS LIKE THE
PALMER DVD AND PIKES PEAK AND TELLER COUNTY AREA COULD SEE SOME PCPN
WED.
THU THE UPR TROF WL BE EAST OF THE AREA...WITH W TO NW FLOW ALOFT
OVR THE AREA AND POSSIBLY SOME LINGERING LIGHT SHOWERS OVR THE
CENTRAL CO MTS...CONTINUING INTO THU NIGHT. ON FRI AND UPR RIDGE
BUILDS OVR THE GREAT BASIN AND THEN MOVES OVR CO FOR SAT...RESULTING
IN DRY WEATHER AND HIGH TEMPS WARMING TO NEAR NORMAL. SUN A NEW UPR
TROF IS FORECAST TO MOVE INTO THE WESTERN STATES AND PUSH THE
UPR RIDGE EAST OF THE AREA...HOWEVER THE WEATHER WL STILL BE DRY
WITH HIGH TEMPS BEING AROUND NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 134 PM MDT MON OCT 28 2013
LATEST HRRR IS BECOMING MORE AGGRESSIVE AT BRINGING IN LOW CLOUDS
FOR KCOS AND KPUB FOR LATER THIS EVENING INTO TONIGHT. WILL LET
ANOTHER RUN COME IN...BUT WILL LIKELY BRING SOME LOW CIGS INTO
KCOS AND KPUB IN TAF AMMENDMENTS A BIT LATER THIS AFTERNOON.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MOORE
LONG TERM...28
AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1229 PM EDT MON OCT 28 2013
.SYNOPSIS...
AN UPPER-LEVEL DISTURBANCE WILL MOVE OVER THE FORECAST REGION TODAY.
THERE WILL BE A CHANCE OF LIGHT SHOWERS AS WELL. HIGH PRESSURE
WILL BUILD ACROSS THE REGION TUESDAY AND WEDNESDAY. A FRONTAL SYSTEM
WILL AFFECT THE AREA LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...
UPPER LEVEL TROUGH WILL MOVE EAST ACROSS THE FA. MAINLY MID-LEVEL
CLOUDS BUT SOME CONVERGENCE AND UPWARD LIFT ARE HELPING TO GENERATE
A FEW SHOWERS. DECIDED TO LOWER POPS A BIT FROM THE 60-80 PERCENT
IN THE SOUTH AND EAST AND WILL GO MAINLY 30-40 PERCENT CHANCE FOR
THE ENTIRE FA. ALSO...WITH THE LOWER POPS DECIDED TO INCREASE
AFTERNOON HIGH TEMPERATURES AGAIN FROM THE UPPER 60S IN THE
NORTHEAST PART TO THE LOWER 70S IN THE SOUTHWEST PART INCLUDING
THE CSRA.
TONIGHT...
THE WEAK DISTURBANCE SHOULD BE GONE TO THE EAST. CONDITIONS
ARE EXPECTED TO BE DRY AS SURFACE RIDGING DEVELOPS. SKIES SHOULD
BECOME PARTLY CLOUDY TO MOSTLY CLEAR LATE TONIGHT ALLOWING LOW
TEMPERATURES TO FALL INTO THE UPPER 40S.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
UPPER RIDGING WILL STRENGTHEN OVER THE AREA AS TROUGH OUT WEST DEEPENS.
NICE INDIAN SUMMER LIKE WEATHER FOR AUTUMN WITH HIGHS IN THE UPPER
70S TO NEAR 80 AND OVERNIGHT LOWS IN THE 50S. DRY CONDITIONS EXPECTED
WITH LIGHT WINDS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
THURSDAY THROUGH FRIDAY NIGHT...
MODELS ARE IN GOOD AGREEMENT WITH APPROACHING WEATHER SYSTEM.
VIGOROUS SHORT WAVE IS EJECTED EASTWARD THURSDAY AND PUSHES UPPER
RIDGE AXIS EASTWARD INTO THE ATLANTIC BY FRIDAY AS A STRONG COLD
FRONT APPROACHES FROM THE WEST. IN THE LOWER LEVELS...SOUTHERLY
FLOW WILL BRING INCREASED MOISTURE THURSDAY. THE GFS AND ECMWF
BRING THE ASSOCIATED COLD FRONT INTO THE FORECAST AREA BY FRIDAY.
THE MODELS HAVE BEEN CONSISTENT INDICATING A STRONG H85 JET
ASSOCIATED WITH THE FRONT. THERE MAY BE ENOUGH DYNAMICS FOR
THUNDERSTORMS ALSO BY FRIDAY. WARMER AHEAD OF THE FRONT WITH HIGHS
MAINLY IN THE UPPER 70S TO NEAR 80. LOWS IN THE LOWER 60S THURSDAY
NIGHT BUT DROPPING BACK INTO THE 50S FRIDAY NIGHT AS COLD FRONT
MOVES IN.
SATURDAY THROUGH MONDAY...
THE EXTENDED FORECAST PERIOD FEATURES COOLER...NEAR TO BELOW NORMAL
TEMPERATURES AND DRY WEATHER AS A COLD FRONT PUSHES OFF THE SOUTH
CAROLINA COAST. AN UPPER LEVEL TROUGH MOVING THROUGH THE OHIO
VALLEY INTO THE MID ATLANTIC AND NORTHEASTERN STATES WILL SHIFT OFF
THE COAST BY SUNDAY WHILE WEAK SHORTWAVE RIDGING DOMINATES EAST OF
THE MISSISSIPPI RIVER THROUGH MONDAY.
STRONG SURFACE HIGH PRESSURE WILL SETTLE OVER THE FORECAST AREA
DURING THIS ENTIRE PERIOD PROVIDING BENIGN RAIN FREE WEATHER WITH A
VERY DRY AIRMASS IN PLACE AS PRECIPITABLE WATER VALUES REMAIN BELOW
A HALF INCH. MAX TEMPERATURES WILL BE IN THE LOWER 70S TO AROUND 70
ON SATURDAY THEN FALL INTO THE 60S SUNDAY AND MONDAY WHILE LOW
TEMPERATURES WILL BE INTO THE 40S AND POSSIBLE SOME UPPER 30S.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
MAINLY VFR CONDITIONS THROUGH THE TAF PERIOD. AN UPPER DISTURBANCE
NEAR THE AL/GA BORDER WILL CONTINUE TO SPREAD CLOUDS ACROSS THE AREA
TODAY. CIGS MAY DIP BELOW 10K FEET IN SOME LOCATIONS ESPECIALLY THIS
MORNING. A FEW SPRINKLES POSSIBLE AS WELL ESPECIALLY DURING THE
MORNING HOURS. AGS/DNL HAVE ALREADY REPORTED LIGHT RAIN EARLY THIS
MORNING. MOSTLY CLOUDY SKIES FOR MUCH OF TODAY AS THE SHORTWAVE
MOVES THROUGH THE REGION. HRRR HI RES MODEL INDICATING SOME PARTIAL
CLEARING BY THIS EVENING. WINDS WILL BE CALM EARLY THIS MORNING
BECOMING MAINLY SW AROUND 5 KNOTS BY LATE THIS MORNING.
EXTENDED AVIATION OUTLOOK...NO RESTRICTIONS TO AVIATION EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BOISE ID
1011 AM MDT MON OCT 28 2013
.DISCUSSION...MORNING SATELLITE PICS SHOWING UPPER-LEVEL LOW OVER
WESTERN NV WITH SURFACE ANALYSIS SHOWING AN ELONGATED SURFACE LOW
ALONG THE NV/UT BORDER AT 15Z. OVER THE NEXT 12 HOURS THE SURFACE
AND UPPER LOW ARE PROGGED TO SHIFT SLIGHTLY NORTH TOWARD THE ID/NV
BORDER. STEADIER PRECIPITATION NEAR THE UPPER LOW CENTER WILL
REMAIN FOCUSED OVER SOUTHERN HARNEY...MALHEUR AND OWYHEE COUNTY
TODAY WHERE SNOW LEVELS WILL BE AROUND 4K FEET MSL. BURNS WILL
LIKELY SEE PERIODS OF SNOW OR A RAIN/SNOW MIX THROUGH THIS
MORNING. FURTHER NORTH AREAS OF SHOWERS WILL TRANSITION FROM SE
TO NW DURING THE DAY BRINGING PERIODS OF LIGHT PRECIPITATION.
SURFACE WINDS IN LOWER VALLEY LOCATIONS THAT DON/T MIX OUT WILL
BE DRIVEN BY SURFACE GRADIENT AND REMAIN OUT OF THE W/NW...WHILE
HIGHER ELEVATIONS TAP INTO THE E/NE FLOW AROUND THE UPPER LEVEL
CIRCULATION. LEANING TOWARD THE GFS AND HRRR SOLUTIONS FOR THE
TREASURE VALLEY WHICH KEEP A NW WIND THROUGH THE DAY. THE NAM
SEEMS TOO QUICK TO MIX THE LOWER VALLEY OUT...ESPECIALLY GIVEN THE
OVERNIGHT PRECIPITATION AND LOW- LEVEL STRATUS THAT HAS DEVELOPED.
THE WESTERN MAGIC VALLEY WILL SEE GUSTY WINDS WITH DIRECTIONAL
SHIFTS LIKELY TIED TO PRECIPITATION. GUSTS OF 30 TO 40 MPH ARE
POSSIBLE IN MOST LOCATIONS AND WILL NEED TO WATCH BAKER COUNTY
THIS AFTERNOON FOR POSSIBLE WIND ADVISORY AS SURFACE PRESSURE
GRADIENT STRENGTHENS.
&&
.AVIATION...SCATTERED MVFR RAIN AND SNOW SHOWERS THROUGH 03Z
TUES...KBOI IFR CONDITIONS THROUGH AT LEAST 18Z IMPROVING TO MVFR
AFTER. MOUNTAINS OBSCURED. SNOW LEVELS NEAR SURFACE AT KBNO AND
AROUND 8000 FEET MSL AT KBOI. LIGHT TO MOD SFC WINDS WITH VARIED
DIRECTION...LOW CONFIDENCE IN WIND DIRECTION FORECAST...GENERALLY
E/SE SFC WINDS SE OF KMUO AND W/NW SFC WINDS WEST OF KBOI. GUSTY
TO 40KT AROUND KBKE. WINDS ALOFT SE 15-25KT WITH AREAS OF 45KT
BECOMING VARIABLE 5-15KT AFTER 12Z TUES.
&&
.PREV DISCUSSION...
SHORT TERM...TODAY THROUGH TUESDAY...UPPER LOW CENTERED NEAR THE
NORTHERN CALIFORNIA/NEVADA BORDER WILL TRACK EASTWARD THROUGH
NORTHERN NEVADA TODAY...THEN HEAD E-NE AND REACH WESTERN WYOMING
ON TUESDAY. SHOWERS HAVE BEEN INCREASING IN COVERAGE ACROSS THE
TREASURE VALLEY AND SOUTH TO THE NEVADA BORDER THIS MORNING. THESE
SHOWERS ARE MOVING TO THE W-NW AND WILL BE SPREADING INTO SE OREGON
IN THE NEXT FEW HOURS. SO FAR...PRECIP AMOUNTS HAVE BEEN LIGHT...
LESS THAN A TENTH /0.10/ OF AN INCH. AS THE LOW MOVES ACROSS
NORTHERN NEVADA...THE SHOWERS WILL BECOME WIDESPREAD AROUND THE LOW
CENTER...WHICH INCLUDE THE OWYHEES AND SOUTHWEST HIGHLANDS IN SW
IDAHO...AND SOUTHERN MALHEUR/SOUTHERN HARNEY COUNTIES IN SE OREGON.
THESE AREAS WILL BE THE PRIMARY FOCUS FOR SHOWERS THROUGH TONIGHT AS
THE LOW STALLS JUST SOUTH OF THE ID/NV BORDER. ON TUESDAY...THE LOW
WILL SHIFT TO THE EAST WITH SHOWERS ENDING IN MOST AREAS BY THE
AFTERNOON. SHOWERS WILL LINGER ACROSS SW IDAHO TO THE SOUTH AND EAST
OF BOISE. TOTAL PRECIP AMOUNTS ARE EXPECTED TO BE UP TO A QUARTER
/0.25/ OF AN INCH IN THE TREASURE/WESTERN MAGIC VALLEYS...UP TO A
HALF INCH IN THE MTNS TO THE NORTH...AND UP TO AN INCH ACROSS
SOUTHERN HARNEY/MALHEUR COUNTIES...THE OWYHEES... AND SOUTHWEST
IDAHO HIGHLANDS. SNOW LEVELS WILL BE HIGH ENOUGH TO LIMIT SNOWFALL
TO THE MOUNTAINS...EXCEPT IN HARNEY COUNTY THIS MORNING WHERE UP TO
AN INCH OF SNOW IS POSSIBLE BETWEEN 4000 AND 5000 FEET. A SURFACE
LOW WILL MOVE INTO SOUTH-CENTRAL IDAHO THIS AFTERNOON...WITH GUSTY
EAST WINDS DEVELOPING TO THE EAST OF IT AND GUSTY NORTH-NORTHWEST
WINDS DEVELOPING TO IT/S WEST. WINDS WILL WEAKEN TONIGHT AND TUESDAY
AS THE LOW DEPARTS TO THE EAST. TEMPERATURES WILL BE MUCH COOLER
TODAY WITH MORE COOLING EXPECTED ON TUESDAY.
LONG TERM...TUESDAY NIGHT THROUGH MONDAY...SHOWERS WILL LINGER
ACROSS SOUTHCENTRAL IDAHO TUESDAY NIGHT...THEN DISSIPATE EARLY
WEDNESDAY AS THE UPPER LOW EXITS TO THE EAST. EXPECT FEWER CLOUDS
AND PROGRESSIVELY WARMER TEMPERATURES WEDNESDAY THROUGH SATURDAY AS
HIGH PRESSURE ALOFT BUILDS ALONG THE WEST COAST AND INLAND OVER THE
INTERMOUNTAIN REGION. IMPROVED MODEL AGREEMENT LENDS TO INCREASED
CONFIDENCE IN THE TIMING OF THE NEXT NOTABLE PACIFIC SYSTEM...WHICH
WILL SPREAD SHOWERS ACROSS SE OREGON AND SW IDAHO LATE SATURDAY
THROUGH EARLY MONDAY.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&
$$
WEATHER.GOV/BOISE
DISCUSSION...DG
AVIATION.....KA
PREV SHORT TERM...BW
PREV LONG TERM....MT
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1244 PM CDT Mon Oct 28 2013
.UPDATE...
Issued at 559 AM CDT MON OCT 28 2013
Observing the band of stratus and dense advection fog lifting
northward across southern Kansas as warm and moist air encounters
the cooler airmass across east central areas. Latest few runs from
the HRRR as well as RAP soundings suggest weak southerly flow to
continue pulling the stratus deck northward along with
visibilities at or below 1/4 mile. Therefore have issued a Dense
Fog Advisory for portions of east central Kansas. As we near
sunrise, question as to if areas along the interstate 70 corridor
will see any mixing begin before stratus moves in. If we are able
to increase low level winds, dense fog will not be of concern.
Will continue to monitor trends for possible expansion northward
later this morning.
&&
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 330 AM CDT MON OCT 28 2013
Currently monitoring the next strong upper shortwave trough as it
rotates east southeast across northern California and northern
Nevada early this morning. Embedded perturbations within the main
system were noted ejecting eastward across the Intermountain west
while an area of subsidence over northeast Kansas was keeping skies
mostly clear. Surface observations note the low pressure center
across southeast Colorado as an inverted trough stretched across
Kansas and Missouri. Southerly winds over much of Kansas into
Oklahoma were pulling dewpoint temperatures in the lower and
middle 50s northward. Fog developing over Oklahoma should try to
make its way into southern Kansas later this morning. Low levels
have managed to stay mixed with temperature dewpoint spreads too large
to warrant widespread fog developing. Best chances for patchy fog
may be possible briefly near sunrise generally south of the Kansas
Turnpike.
The inverted trough deepens Monday afternoon as dewpoints increase
into the 50s across central and east central Kansas behind a warm
front positioned from west central Kansas to northwest Missouri.
Light winds veer to the south and increase through the low levels,
providing warm air advecting temps into the upper 60s and low 70s.
Short term guidance and analysis suggest a strong capping inversion
in place along with lack of strong forcing in the mid levels which
should keep much of the forecast dry for most of the afternoon. By
late afternoon into early evening, focus then turns west of the area
as mid level moisture and instability increases. Latest guidance
from the 4 km WRF and NAM suggest scattered convection may develop
after 5 PM across north central areas in vicinity of the warm front.
Surface based CAPE values are meager around 300 J/KG, however strong
veering of the winds throughout the column with effective shear up
to 6 km in the 50 kt range suggest if a surface based storm were
able to develop, supercell structures would be possible with large
hail and localized damaging winds being the primary concern.
Boundary layer should quickly stabilize towards sunset as widespread
showers and thunderstorms become more rooted in the mid levels. A
strong and veering low level jet overnight Monday along with a mid
level vort max in place should provide ample support for showers and
thunderstorms to spread eastward across the entire area through the
overnight hours. Mixed layer cape shifts east up to 1000 J/kg with
effective shear over 50 kts suggest isolated severe hail may
continue to be a threat for the area. Rainfall amounts around an
inch are possible especially across east central and northeast
areas. Within the warm sector, overcast skies, and scattered
convection low temperatures are expected to be much warmer in the
lower to middle 50s.
.LONG TERM...(Tuesday through Sunday)
Issued at 330 AM CDT MON OCT 28 2013
With the closed upper low now over the west coast and sampled
better, the models seem to be converging on the timing of the
system. And interestingly it seems as though the trend has been
towards the slightly faster solution of the GFS. Continued the
trend of the prev forecast with POPs diminishing Tuesday
afternoon. While there may be some precip ongoing early Tuesday,
large scale forcing for continued precip doesn`t appear to be
there. So with the weakening low level jet think a lull in precip
is possible Tuesday afternoon and Tuesday evening. The next
shortwave is progged to lift out from the base of the upper low on
Wednesday with the low itself moving across the state Wednesday
night. There should be more than enough moisture and with little
inhibition to convection so think showers and thunderstorms are
likely to be widespread once again. There continues to be a chance
that some of the storms Wednesday could become severe as deep
layer shear remains favorable for supercell storms. The main
uncertainty is whether there will be enough insolation to
destabilize the boundary layer and whether there will be a whole
bunch of storm interactions such that updrafts have a hard time
organizing into supercells. Nevertheless it bares watching. With
the strong low level moisture advection anticipated, temps should
be very mild for late October with highs around 70 and lows in the
upper 50s to lower 60s. The main adjustment to the forecast was to
account for the faster progression of the front on Thursday, which
most guidance brings through eastern KS by the mid morning hours.
With this in mind the forecast reflects diminishing POPs through
the morning with cooler minimum temps Thursday morning.
Friday through Sunday continues to look dry as the cold front
pushes all of the moisture east. Models show a wave within the
northwest flow for Friday, but there isn`t much moisture for it to
work with. The dry northwest flow is expected to persist through
Saturday before the next upper level shortwave trough moves
inland over the west coast causing pressure falls along the lee of
the Rockies and a southerly wind to return to the forecast area.
Temps Friday and Saturday still look to be seasonable before a
modest warm up occurs with increasing warm air advection from the
south on Sunday.
&&
.AVIATION...(For the 18Z TAFs through 18Z Tuesday Afternoon)
Issued at 1243 PM CDT MON OCT 28 2013
For the 18z TAFs, a scattered to broken stratus deck was lifting
northward toward the I-70 corridor this morning. As a result, cig
conditions may periodically drop down to IFR this afternoon. However
this deck should lift by mid to late afternoon with scattered MVFR
cigs possible. By this evening, the potential for rain and scattered
thunderstorms increases with more widespread precipitation expected
during the overnight hours through Tuesday morning. Cigs/vis should
initially drop down to MVFR but model guidance and several model
soundings show conditions quickly dropping IFR and possibly near
LIFR early Tuesday morning and persisting through the end of the
period. There is still some uncertainty though with the exact timing
of this change in categories. Through the period winds will
generally be out of the southeast at around 10kts or less, however
cannot rule out some occasional stronger winds with the
thunderstorms.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Bowen
SHORT TERM...Bowen
LONG TERM...Wolters
AVIATION...Hennecke
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
140 PM EDT MON OCT 28 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 435 AM EDT MON OCT 28 2013
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW POTENT SHRTWV
ACCOMPANIED BY 140KT H3 JET MAX SLIDING ESEWD THRU ONTARIO IN THE NW
FLOW ALF BTWN MEAN TROF OVER ERN CANADA AND A RDG OVER THE ROCKIES.
ATTENDANT COLD FNT PUSHED THRU UPR MI LAST EVNG ACCOMPANIED BY SOME
-SHRASN MAINLY OVER THE NRN TIER COUNTIES AND WAS FOLLOWED BY SOME
GUSTY N WINDS THAT PEAKED AS HI AS 41 KT AT THE STANNARD ROCK
LIGHTHOUSE IN SCENTRAL LK SUP. ALTHOUGH THE LARGE SCALE PCPN HAS
DIMINISHED FOLLOWING THE EXIT OF THE DEEPER MSTR...SOME LES AIDED BY
THE ARRIVAL OF H85 TEMPS DOWN TO -10 TO -11C IS OCCURRING NEAR LK
SUP...MAINLY OVER THE NCENTRAL WHERE LLVL NNE FLOW BTWN SFC HI PRES
IN SASKATCHEWAN THE DEPARTING COLD FNT IS PRESENTING A SHARPER
UPSLOPE WIND COMPONENT. BUT EVEN HERE THE LES IS RATHER LIGHT...WITH
CONSIDERABLE DEEP LYR QVECTOR DVGC/SUBSIDENCE DROPPING THE INVRN
BASE TOWARD 4K FT AND SHARPENING ACYC LLVL FLOW WEAKENING THE NEAR
SFC CNVGC. THE NEAR SFC LYR IN THE INCOMING AIRMASS IS NOT OVERLY
MOIST EITHER...WITH SFC DEWPT AT CKC IN THE MN ARROWHEAD DOWN TO 12F
AT 05Z AND HAS RESULTED IN CLRG JUST UPWIND OF THE LK. 00Z INL/YPL
RAOBS ALSO SHOW THIS DRYNESS. BUT MORE SC LINGERS FARTHER TO THE N
INTO ONTARIO/SRN MANITOBA/NW MN. THERE IS PARTIAL CLRG OVER FAR NW
ONTARIO W THRU LK WINNIPEG CLOSER TO THE SFC HI CENTER AND WHERE THE
00Z RAOB FM THE PAS MANITOBA SHOWS INVRN BASE BLO H9...BUT EVEN HERE
BKN SC ARE PRESENT.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE LES AND LO CLD TRENDS.
TODAY...UNDER CONFLUENT NW FLOW ALF...SFC HI PRES NOW CENTERED OVER
SASKATCHEWAN IS PROGGED TO DRIFT OVER NW MN BY 00Z TUE. EXPECT GUSTY
WINDS EARLY THIS MRNG TO DIMINISH STEADILY WITH THE ARRIVAL OF
FLATTER PRES GRADIENT. HIER RES MODELS INDICATE THE MOST PERSISTENT
SHSN IN LLVL N-NE FLOW WL IMPACT THE HIER TERRAIN OF THE NCENTRAL
AND THE FAR W FM ONTONAGON TO IWD...WHERE MOISTENING OFF LK NIPIGON
IS INDICATED TO HAVE A POSITIVE IMPACT. GOING POPS APPEAR TO HAVE
THESE TRENDS IN HAND. BUT THE SHARP LLVL ACYC FLOW/LO INVRN BASE
BTWN 3-4K FT/PRESENCE OF DGZ ABV THE RELATIVELY SHALLOW LK MOISTENED
LYR WL LIKELY HOLD DOWN SN ACCUMS TO NO MORE THAN AN INCH OR SO
DESPITE FVRBL LK WATER-INVRN BASE DELTA T ARND 17C. ALTHOUGH THERE
IS SOME CLRG IMMEDIATELY UPSTREAM OF THE LK RIGHT NOW...SUSPECT THE
BKN-OVC SC A BIT FARTHER TO THE N-NW AND SUBSTANTIAL OVERWATER
INSTABILITY ARE SIGNS THE LO CLDS WL BE QUITE RESILIENT. SO TENDED
TOWARD THE LOWER END OF GUIDANCE FOR MAX TEMPS.
TNGT...SFC HI PRES CENTER IS PROGGED TO DRIFT ALMOST RIGHT OVER UPR
MI BY 12Z TUE. WHILE THIS TREND WOULD SUG THE SC WL DSPT AND LO
TEMPS WL PLUNGE UNDER PWAT FALLING BLO 0.25 INCH/LGT WINDS...
CONCERNED THERE IS A GOOD AMOUNT OF LO CLD OBSVD THIS MRNG UPSTREAM
TO THE HI CENTER THAT COULD WREAK HAVOC WITH LO TEMPS FCST. SOME HI
CLDS MAY ALSO FILTER INTO THE AREA. WITH THE LLVL FLOW BACKING MORE
NW WITHIN LLVL THERMAL TROF...SUSPECT THE SC WL BE MOST TENACIOUS E
OF MQT. MAINTAINED FLAVOR OF PREVIOUS FCST SHOWING THE LOWEST TEMPS
OVER THE INTERIOR W HALF AND SCENTRAL INTO THE TEENS...BUT TENDED TO
RAISE THE FCST MINS A BIT TO ACCOUNT FOR THE UNCERTAINTY ON CLRG
TRENDS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 435 AM EDT MON OCT 28 2013
BRIEF PATTERN CHANGE REMAINS ON TRACK FOR THIS WEEK AS SPLIT FLOW
DEVELOPS. UPPER TROUGH THAT HAS BEEN OVER THE GREAT LAKES RECENTLY
SLIDES ACROSS EASTERN CANADA WHILE CUTOFF LOW SLOWLY MOVES FROM THE
WEST COAST TO THE CENTRAL PLAINS. 00Z MODELS STILL SHOWING SOME
DIFFERENCES BUT ARE STARTING TO COME TOGETHER IN TERMS OF POSITION
OF PLAINS UPPER LOW THROUGH WEDNESDAY. A BIT MORE DIFFERENCE BY
THURSDAY...BUT EVEN HERE THERE IS DECENT MODEL CLUSTERING OF
STRENGTH AND TRACK OF SFC LOW 00Z THURSDAY THROUGH 18Z THURSDAY.
MORE DIFFERENCES BEGIN TO EMERGE LATER THURSDAY INTO FRIDAY MAINLY
WITH REGARD TO HOW QUICKLY THE LOW EXITS THE UPPER GREAT LAKES. LOW
PRESSURE MOSTLY RESULTS IN A RAIN EVENT FOR MID-LATE WEEK WITH SNOW
RE-ENTERING THE PICTURE BY NEXT WEEKEND AS COLDER AIR FILTERS ACROSS
THE GREAT LAKES IN WAKE OF THE LOW PRESSURE SYSTEM.
LARGE SPRAWLING HIGH PRESSURE OF 1033MB WILL BE CENTERED VERY NEAR
UPR MICHIGAN TO START THE DAY ON TUESDAY WHILE AN INITIAL WAVE OF
LOW PRESSURE FORMS IN THE SOUTHERN PLAINS. EVEN THOUGH A RIDGE OF
HIGH PRESSURE HOLDS AT THE SFC THROUGH TUESDAY NIGHT OVER THE UPPER
GREAT LAKES...HINT IS THERE FOR A WHILE THAT THERE MAY BE SOME LIGHT
PRECIP OVER THE AREA THROUGH THE EVENING. MAIN INSTIGATOR FOR THE
PRECIP IS SHORTWAVE DROPPING ACROSS NORTHERN ONTARIO IN NW FLOW ON
WESTERN EDGE OF RETREATING TROUGHING. MOST OF LARGER SCALE FORCING
FOR ASCENT FM SHORTWAVE /H7-H5 AND H5-H3 Q-VECTOR CONVERGENCE/ STAYS
NORTH OF CWA. HOWEVER...INCREASE IN MOISTURE AND WARM AIR ADVECTION
TEAMS UP WITH DIVERGENCE ALOFT FM JET STREAK SLIDING EAST TOWARD
QUEBEC TO GENERATE SOME MID-LEVEL LIFT. LEFTOVER ISSUE IS WHETHER
LOW-LEVEL DRY AIR OWING TO THE SFC HIGH WILL BE ERODED ENOUGH TO
RESULT IN PRECIP MAKING IT TO THE SFC. /THIS IS OF COURSE ASSUMING
THAT LOW CLOUDS AROUND TONIGHT DO IN FACT CLEAR OUT LATER TONIGHT OR
TUESDAY MORNING/. SINCE THE DRYING WILL NOT BE RE-INFORCED BY DRY
ADVECTION...THINK MID-LEVEL MOISTURE AND LIFT EVENTUALLY ALLOWS LGT
PRECIP TO MAKE IT TO SFC. SOUNDINGS FM THE NAM AND THICKNESSES
INDICATE MAINLY SNOW FOR PTYPE. ONLY SCNTRL WITH LGT SE WINDS OFF LK
MICHIGAN MAY SEE RAIN BE MAIN PTYPE.
WHERE SNOW OCCURS AS PTYPE...THERE IS A LEAST SOME CHANCE OF MINOR
ACCUMS AS...DESPITE IT HAPPENING IN THE AFTN/EVENING...BANDED SNOW
COULD FALL AT AN OKAY CLIP WITH STRONGER FORCING IN MID-LEVELS. NAM
WHICH IS GRANTED THE MOST AGGRESSIVE WITH QPF AND DURATION OF
HEAVIER QPF SHOWS SNOW ACCUMS OVER 2 INCHES OVER SOUTHWEST CWA 18Z
TUE THROUGH 06Z WED. WILL NOT GO THIS BULLISH YET AS THE NAM IS AN
OUTLIER...BUT WILL BUMP POPS UP TO HIGHER CHANCE RANGE. ECMWF/GEM-NH
AND UKMET ALSO GENERATING QPF OVR UPR MICHIGAN BUT NOT NEAR AS HEAVY
AS NAM. TIMING AND EXTENT OF SNOW SOMETHING TO KEEP AWARE OF AS IT
COULD IMPACT EVENING TRAVEL OVER SOUTHWEST UPR MICHIGAN AND MAYBE
INTO CNTRL AND EASTERN CWA.
DECENT AGREEMENT THAT LGT PRECIP TAPERS OFF BY LATER EVENING AS
MAIN JET STREAK MOVES FARTHER EAST AND MID-LEVEL MOISTURE DEPARTS.
LOW-LEVEL MOISTURE REMAINS THROUGH THE REST OF TUESDAY NIGHT WITH
VERY WEAK WINDS AS SFC RIDGE AXIS LINGERS. COULD SEE SOME FOG WITH
THIS SETUP IF MOISTURE THINS OUT MORE THAN SHOWN ON SOUNDINGS. AT
THE LEAST SOME STRATUS SHOULD PERSIST INTO WEDNESDAY. LOW-LEVEL
WINDS GRADUALLY BECOME MORE SOUTHEASTERLY TO THE NORTH OF WARM
FRONT...WHICH BASED ON SFC WINDS/DWPNT GRADIENT...COULD BE AS FAR
NORTH AS CNTRL WISCONSIN BY 00Z THURSDAY. SE WINDS MAY HOLD IN
STRATUS MOST OF THE DAY OVER UPSLOPE AREAS OF CNTRL UPR MICHIGAN
THANKS TO LESS MIXING DUE TO LOWER SUN ANGLE THIS TIME OF YEAR.
ELSEWHERE...WOULD EXPECT INCREASING HIGH AND MID CLOUDS OUT AHEAD
OF DEVELOPING PLAINS SYSTEM AND WARM FRONT. MAIN QUESTION FOR
WEDNESDAY IS WHETHER PRECIP MOVES BACK IN THROUGH THE DAY. GFS WOULD
SUGGEST SO...WHILE THE ECMWF/GEM-NH AND UKMET KEEP QPF SOUTH OF CWA
UNTIL WEDNESDAY NIGHT. EVEN GFS HAS SHOWN A TREND TOWARD DRIER
WEATHER HOLDING...AT LEAST OVER THE NORTHERN CWA. HAVE SLIGHT CHANCE
POPS GOING AND THAT PROBABLY WORKS FOR NOW...AT LEAST UNTIL MORE
SIGNAL SHOWS UP THAT WARM FRONT AND PRECIP WILL BE FARTHER NORTH.
SUPPOSE THERE COULD BE SOME DRIZZLE FM THAT PERSISTING LOW CLOUD
DECK AND UPSLOPE FLOW. SLIGHT CHANCES COVER THIS JUST FINE FOR NOW.
LOWERED MAX TEMPS OVER THE WEST HALF INTO LOWER 40S WITH PERSISTING
CLOUDS.
RAIN IS STILL ON FOR WEDNESDAY NIGHT AS PLAINS UPPER TROUGH HEADS
EAST AND PROPELS DEEPENING SFC LOW TOWARD UPR LAKES...VCNTY OF
NORTHERN WI OR UPR MICHIGAN BY 12Z THURSDAY WITH MSLP SOMEWHERE NEAR
990MB. MOISTURE ADVECTION AND WARM AIR ADVECTION AHEAD OF LOW WILL
COMBINE WITH STRONG DIVERGENCE ALOFT ON NOSE OF 140+ KT JET STREAK
ROARING NORTHEAST OUT OF THE CENTRAL PLAINS. PWATS OVER 1 INCH OR
OVER 200 PCT OF NORMAL COMBINE WITH THE FORCING TO SPREAD A SWATH OF
MODERATE RAIN ACROSS ALL CWA. STILL SOME SMALL TIMING DIFFERENCES AS
THE GFS/GEM-NH QUICKER IN BRINGING RAIN ACROSS THE AREA. ECMWF IS
SLOWER BY ABOUT 6 HRS. KEPT A BROADBRUSHED 80 PCT CHANCE FOR
WEDNESDAY NIGHT. REFINEMENTS TO TIMING CAN BE MADE LATER ON. DRY
SLOT LIKELY BECOMES A FACTOR INTO DAYTIME HOURS ON THURSDAY...YET
MAY SEE AN ADDITIONAL AREA OF ENHANCED RAIN FROM DEFORMATION
INDICATED BY H7-H5/H5-H3 Q-VECTOR CONVERGENCE. HIGHEST POPS ON
THURSDAY WILL BE IN THE EAST CLOSER TO LOW-LEVEL JET AXIS AND H85-H7
MOISTURE TRANSPORT. WARMEST DAY OF THE WEEK ON THURSDAY WITH MAX
TEMPS INTO THE 50S. BASED ON LOCATION OF DRY SLOT AND H7-H5 LAPSE
RATES...TSRA PROBABLY END UP FIRING JUST TO THE SOUTH AND EAST OF
CWA...SO LEFT THAT OUT FOR NOW. WINDS PROBABLY WILL BE A FACTOR
SOMETIME ALONG THE WAY AS WELL GIVEN THE DEEPENING LOW AND WITH
TIGHT PRESSURE GRADIENT/STRONG WIND FIELDS FORECAST IN THE VCNTY OF
THE LOW. BEST CHANCE FOR ADVY GUSTS WOULD BE ALONG LK MICHIGAN LATER
WEDNESDAY NIGHT INTO THURSDAY MORNING...THEN ALONG LK SUPERIOR ONCE
LOW MOVES BY THURSDAY NIGHT INTO FRIDAY MORNING.
MID-LEVEL TROUGHING LINGERS FROM FRIDAY INTO NEXT WEEKEND AND THERE
ARE INDICATIONS THERE COULD BE A COUPLE PERIODS OF ENHANCED PRECIP
CHANCES IN THE MEAN TROUGHING AS SHORTWAVES AND/OR RE-INFORCING COLD
FRONTS SLIDE THROUGH. COLDER AIR CHARGES BACK IN ON FRIDAY. BASED ON
1000-850MB AND 850-700MB THICKNESSES FM ECMWF/GFS SHOULD START TO
SEE SNOW MIXING IN ON FRIDAY OVER AT LEAST WEST HALF INTERIOR.
AIRMASS CHILL INTO NEXT WEEKEND IS SIMILAR TO RECENT STRETCH OF
COOLER TEMPS WITH H85 TEMPS DOWN BLO -6C BUT NOT QUITE TO -12C.
SINCE THERE LOOKS TO BE SOME DEEPER MOISTURE AROUND AS
WELL...PROBABLY WILL HAVE TO CONTEND WITH LAKE ENHANCED RAIN AND
SNOW SHOWERS AT TIMES. SOME SNOW ACCUMULATION WOULD BE FAVORED AT
TIMES FOR THE FAVORED LAKE EFFECT AREAS NEAR LK SUPERIOR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 139 PM EDT MON OCT 28 2013
HIGH-END MVFR TO LOW-END VFR CLOUDS ARE SLOWLY ERODING ACROSS UPPER
MI UNDER A WEAK INVERSION AROUND 4KFT. BOTH IWD AND SAW ARE ON THE
EDGE OF BKN TO OVC CLOUDS AND SHOULD SCATTER OUT BY LATE AFTERNOON.
A BREAK IN OVC CLOUDS SHOULD ALSO OCCUR IN CMX...THOUGH SOME
GUIDANCE IS HINTING THAT ANOTHER ROUND OF LOW-END VFR CLOUDS COULD
BE POSSIBLE OVERNIGHT. OVERALL CONFIDENCE OF CLOUD-COVER EVOLUTION
AT ALL SITES IS LOW GIVEN THE CURRENT CONVOLUTED CLOUD PATTERN AND
GENERALLY STAGNANT AIR MASS. HOWEVER...HIGH-END MVFR CIGS WOULD BE
THE LOWEST EXPECTED AT ANY SITE. AHEAD OF A SYSTEM DEVELOPING IN THE
UPPER MS VALLEY...MID-LEVEL CLOUDS WILL SPREAD NORTHEASTWARD ACROSS
THE AREA BY THE END OF THE PERIOD...WITH IFR CONDITIONS POSSIBLE FOR
CMX AND IWD TUESDAY AFTERNOON.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 435 AM EDT MON OCT 28 2013
WITH HI PRES BUILDING TOWARD THE UPPER GREAT LAKES...EXPECT N WINDS
UP TO 30 KTS EARLY THIS MORNING TO DIMINISH STEADILY THRU THE DAY
AND TO BECOME LIGHT TONIGHT AS THE HI CENTER MOVES OVER THE AREA.
THESE LIGHT WINDS LESS THAN 20 KTS STAY IN PLACE TUESDAY THROUGH
WEDNESDAY AS HIGH PRESSURE PERSISTS THEN EXPECT INCREASING SE-E
WINDS LATER WEDNESDAY NIGHT OUT AHEAD OF DEEPENING LOW PRESSURE IN
THE MIDDLE MISSISSIPPI RIVER VALLEY. LOW FORECAST TO LIFT ACROSS LK
SUPERIOR BY THURSDAY NIGHT. DEPENDING ON TRACK OF LOW...WINDS MAY
DIMINISH FOR A TIME ON THURSDAY. YET...ONCE THE LOW MOVES TO THE EAST
OF LK SUPERIOR...NORTHWEST WINDS INCREASE TO 30 KTS THURSDAY NIGHT
INTO FRIDAY. HIGH PRESSURE QUICKLY BUILDING IN ALONG WITH COLD AIR
ADVECTION COULD ALLOW FOR SOME GALES TO OCCUR. STRONG NORTHWEST WINDS
TO 30 KTS CONTINUE INTO NEXT WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...KLUBER
MARINE...KC/JLA
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1213 PM CDT Mon Oct 28 2013
.SHORT TERM: (Through Late This Afternoon)
Issued at 308 AM CDT Mon Oct 28 2013
One more day of quiet weather across the Bi-State Region as a weak
upper level ridge moves across the Mississippi Valley. Should see
plenty of sunshine today due to the dry air which remains locked in
place over the region; though higher clouds will be increasing later
in the day as the subtropical jet draws Pacific moisture up ahead of
the the strong cutoff low over California and Nevada. Surface
cyclogenesis will ramp up over eastern Colorado today which will
increase southerly flow across the southern Plains and Deep South.
This will help to develop a warm front between a strong Canadian
high diving into the Upper Midwest and warm moist Gulf of Mexico air
trying to build up from the south. The NAM suggests that the front
may make it much of the way through Missouri and perhaps parts of
southwest Illinois, while the GFS and RAP aren`t as aggressive.
Either way, not sure there will be much difference in sensible
weather other than higher levels of surface humidity. Surface
temperatures are nearly identical for today on all short range
guidance, so have followed guidance numbers closely.
Carney
.LONG TERM:
(Tonight through Sunday) Issued at 308 AM CDT Mon Oct 28 2013
(Tonight through Thursday Night)
Little change required as going forecast has a good handle on the
situation. Still appears that this will be an active period
beginning late tonight with the likelihood of a widespread soaking
rain with potential for a few strong thunderstorms.
Followed the ECMWF which has been the most consistent with the
overall evolution of the weather pattern the next few days. Most of
tonight will remain dry until strong moisture convergence moves into
central Missouri after 09Z on the nose of a 45kt low level jet.
This low level forcing will move in concert with a shortwave trough
across the CWA tomorrow morning. Will have likely or categorical
pops going over central Missouri starting late tonight and then
spread them eastward across eastern Missouri into southwest Illinois
tomorrow morning.
Then showers and thunderstorms will become more scattered on Tuesday
afternoon and Tuesday Night as the shortwave passes to the east.
The ECMWF depicts an upper ridge moving east across the Midwest
through 12Z Wednesday. Thereafter, strong mid level ascent will
set up between midday Wednesday until the trough currently over
the western CONUS passes through our area on Thursday. Strong
moisture transport and convergence will be occurring beneath this mid
level ascent ahead of the approaching attendant surface cold
front. Likely or categorical pops for showers and thunderstorms
are still warranted ahead of the front Wednesday into Thursday.
There will continue to be the potential for strong thunderstorms
during this period given the very strong low level and deep layer
shear. Risk remains conditional on the amount of instability that
will be available which will be dependent on how much precipitation
is occurring ahead of the front. Will go ahead a mention the
potential for a few strong thunderstorms in the Hazardous Weather
Outlook.
Will keep a lingering chance of showers on Thursday night behind the
cold front. MOS temperatures are in good agreement and generally
followed.
(Friday Through Sunday)
There is good agreement that late week into next weekend will be
dry behind Thursday`s cold front. Both the GFS/ECMWF brings a
second upper trough with an attendant cold front through the
Midwest on Friday, though forcing and moisture looks to be too
limited to warrant any mention of rain chances at this point. This
trough will then move east and upper heights will rise as a ridge
builds in from the west.
Britt
&&
.AVIATION: (For the 18z TAFs through 18z Tuesday Afternoon)
Issued at 1148 AM CDT Mon Oct 28 2013
A cold front has sagged swd into nrn MO and cntrl IL late this
mrng. A weak e-sely sfc wind can be expected this aftn and tgt,
increasing from a sely direction Tuesday mrng. High level
cloudiness will be increasing this aftn and tgt. The cloud ceiling
will lower late tgt and Tuesday mrng as a warm front approaches
from the sw, and a swly low level jet over the cntrl and srn Plains
brings increasing low level warm air advection and moisture into
our area. Showers and a few thunderstorms will spread ewd into COU
by early Tuesday mrng and into the rest of the taf sites by late
mrng or early aftn. Will lower the cigs and vsbys into the mvfr
catagory in COU Tuesday mrng with showers.
Specifics for KSTL: A weak e-sely sfc wind can be expected this
aftn and tgt, increasing to 8-9 kts Tuesday aftn from a sely
direction. High level clouds will stream into STL later this aftn
and tgt with the cloud ceiling lowering into the mvfr catagory
Tuesday aftn as showers and a few storms move into STL.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
236 PM EDT MON OCT 28 2013
.SYNOPSIS...
A WARMING TREND IS EXPECTED IN THE DAYS AHEAD WITH TEMPERATURES
RUNNING ABOVE NORMAL TUESDAY THROUGH THE UPCOMING WEEK. A COLD
FRONT WILL BRING UNSETTLED WEATHER FRIDAY AND SATURDAY FOLLOWED
WITH COLDER AIR INTO THE REGION SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM MONDAY...A COOL AND CLOUDY DAY CONTINUES ACROSS MUCH
OF THE CAROLINAS. THIS SLIGHTLY UNSETTLED WEATHER IS CAUSED BY A
COMBINATION OF TWO FEATURES...A WELL-DEFINED UPPER LEVEL LOW
PRESSURE...AND A STRONG SURFACE RIDGE OF HIGH PRESSURE.
ALTHOUGH UPPER LOW HAS BEEN DAMPENING ALL DAY...A STILL
EASILY-RECOGNIZED CENTER IS MOVING ACROSS SC...AND WILL DRIFT EAST
NEARLY OVERHEAD THROUGH TONIGHT. WEAK ISENTROPIC LIFT AHEAD OF THIS
FEATURE HAS BEEN PRODUCING LIGHT SHOWERS/SPRINKLES ACROSS THE AREA
TODAY...BUT THIS IS SLOWLY WEAKENING...AND GUIDANCE SHOWS IT
SHUTTING OFF IN THE NEXT FEW HOURS. STILL...HAVE CONTINUED MENTION
OF ISOLATED SHOWERS THROUGH THE EVE...BUT QPF WILL BE GENERALLY
ZERO...0.01-0.02 AT BEST. THE SECOND ROUND OF PRECIP BACK ACROSS
GEORGIA IS MORE CONVECTIVELY DRIVEN THANKS TO STEEPENED LAPSE RATES
BENEATH THE -17C COLD POOL. AS THIS MOVES EAST AND ABOVE THE SURFACE
HIGH PRESSURE...IT HAS SHOWN SIGNIFICANT WEAKENING (THANKS ALSO IN
PART TO THE UPPER LOW FILLING)...AND THUS DO NOT ANTICIPATE ANY
PRECIP AS THE LOW CENTER MOVES OVERHEAD THIS EVE. HIGH-RES GUIDANCE
AGREES WITH THIS...NEITHER THE HRRR OR WRF SUGGEST ANY PRECIP ACROSS
THE CWA TONIGHT...SO HAVE CUT BACK POP TO SILENT AFTER DARK.
WITH THE LACK OF SUNSHINE /DRYING/ TODAY...AND A MOISTENED
COLUMN...FOG IS A POSSIBILITY LATE TONIGHT. HAVE CONTINUED MENTION
OF PATCHY/AREAS OF FOG ACROSS THE AREA AS BUFR SOUNDINGS DEPICT GOOD
SURFACE SATURATION AND LOW-LEVEL HYDROLAPSE RATES...AND FORECAST
LOWS APPROACH CROSSOVER TEMPS. THE INHIBITING FACTOR TO WIDESPREAD
FOG WILL BE CONTINUED MID-LEVEL CLOUD COVER WHICH WILL INHIBIT...AT
LEAST PARTIALLY...RADIATIONAL COOLING. THIS SAME CLOUD COVER WILL
KEEP MINS FROM FALLING TOO LOW...AND HAVE LEANED PRIMARILY ON THE
WARMER LAV NUMBERS SINCE THE MET/MAV CONTINUE TO BE TOO COOL. EXPECT
LOWS A DEGREE OR TWO EITHER SIDE OF 50 ACROSS THE AREA.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 230 PM MONDAY...THE HEADLINE WEATHER STORY TUESDAY THROUGH
WEDNESDAY IS THE EVOLUTION OF A LATE OCTOBER WARMING TREND WITH
MAXIMUM TEMPERATURES RUNNING 4-9 DEGREES ABOVE NORMAL BOTH DAYS
WITH WEDNESDAY BEING THE WARMER. DAYBREAK TUESDAY A SHORT-WAVE
WILL BE EXITING THE COAST...AND IN IT`S WAKE AMPLIFICATION OF
HEIGHTS ALOFT OCCUR AS AN UPPER RIDGE BULGES INTO THE CAROLINAS
ESPECIALLY ON WEDNESDAY. THE PROXIMITY OF HEIGHT RISES WILL
BOLSTER SURFACE HIGH PRESSURE...ALLOWING A SURFACE ANTI-CYCLONE
OVER THE GREAT LAKES TO BUILD SE INTO CAROLINAS BEFORE SLIPPING
OFFSHORE EARLY ON THURSDAY.
MINIMUM TEMPERATURES TOO WILL BE RUNNING ABOVE NORMAL FOR THE
SEASON BUT ONLY BY SEVERAL DEGREES SINCE OVERNIGHT RADIATION
COOLING WILL BE DECENT TO VERY GOOD...ALLOWING HEAT ESCAPE AND
SUBSEQUENT NIGHT-TIME COOLING AND A SOLID EARLY MORNING INVERSION
EACH DAY. BOUTS OF FOG COULD BE AN ISSUE BUT CONFIDENCE IS NOT
HIGH ENOUGH FOR INCLUSION INTO THE ZONES SINCE OCCASIONAL CLOUDS
COULD INHIBIT FORMATION. DRY MID-LEVEL AIR DUE TO THE RIDGING
ALOFT WILL PREVENT ANY MENTIONABLE POP VALUES THIS PERIOD.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 230 PM MONDAY...THURSDAY HIGHS TO END UP JUST SHY OF 10
DEGREES ABOVE CLIMO WITH SURFACE AND UPPER LEVEL RIDGING OFF THE
EAST COAST. SIMILARLY A VERY MID THURSDAY NIGHT EXPECTED AS THE
LOW LEVEL FLOW IS INCREASED AND VEERED BY THE APPROACH OF A COLD
FRONT. FRIDAY STILL FINDS US IN A VERY WARM AIRMASS BUT INCREASING
CLOUD COVER SHOULD TEMPER HIGHS A BIT. THE SLOW MOVEMENT OF THE
BOUNDARY WHICH WILL BE ALIGNED WITH THE SOUTHWESTERLY MID LEVEL
FLOW IMPLIES THAT PRECIP SHOULD BE HARD-PRESSED TO OCCUR MUCH
AHEAD OF THE BOUNDARY ITSELF. BEST RAIN CHANCES THUS COME WITH
ACTUAL FROPA FRIDAY NIGHT...INTO SATURDAY MORNING ALONG THE COAST.
LOW LEVELS DRY OUT SATURDAY BY THE DEEPER LAYER DRY AIR ADVECTION
WILL HAVE TO WAIT FOR THE TOUGH AXIS TO SWEEP THROUGH SATURDAY
NIGHT. VERY LARGE HIGH BUILDS ACROSS NORTHEAST AND MID ATLANTIC
SUNDAY AND MONDAY. THE ENSUING COLD ADVECTION LOOKS TO SIMPLY
RETURN TEMPERATURES TO THEIR SEASONABLE NORMS ON SUNDAY AND
ROUGHLY A CATEGORY LOWER BY MONDAY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...SOME SPRINKLES ARE POSSIBLE THIS AFTERNOON...ASSOCIATED
WITH AN UPPER LOW CENTERED OVER WESTERN NORTH/SOUTH CAROLINA. THE
ISOLATED SPRINKLES WILL POSE NO AVIATION PROBLEMS...WITH JUST MID
CLOUD CEILINGS EXPECTED THIS AFTERNOON. AN EAST/SOUTHEAST WIND IS
EXPECTED ALONG THE COAST...WITH VARIABLE WIND INLAND.
TONIGHT...THERE MAY BE ENOUGH BREAKS IN THE CLOUDS FOR WEAK
RADIATIONAL COOLING...WITH LIGHT FOG JUST BEFORE SUNRISE...BEST
CHANCE INLAND. TUESDAY...MAINLY MID/HIGH CLOUDS WITH LIGHT WINDS.
EXTENDED OUTLOOK...EARLY MORNING FOG POSSIBLE TUESDAY AND WEDNESDAY.
CHANCE OF SHOWERS FRIDAY INTO SATURDAY WITH AN APPROACHING COLD
FRONT. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM MONDAY...HIGH PRESSURE WITH A DIFFUSE CENTER ALIGNED
ROUGHLY ALONG THE CAROLINA COASTS IS SLOWLY DRIFTING EAST...AS IT
GETS PUSHED AWAY BY A MUCH STRONGER HIGH /1040MB CENTERED OVER
CENTRAL CANADA/. THIS WILL HAPPEN SLOWLY TONIGHT...THUS THE
CURRENT WEAK PRESSURE GRADIENT WILL PERSIST MUCH OF THE
PERIOD...ONLY GRADUALLY TIGHTENING TOWARDS DAYBREAK TUESDAY. THIS
WILL KEEP LIGHT AND VARIABLE WINDS THROUGH ABOUT MIDNIGHT...BEFORE
A WEAK NORTHERLY SURGE DEVELOPS...DRIVING WINDS UP TO AROUND 10
KTS BY MORNING. SEAS WILL REMAIN LOW- AMPLITUDE...1-2
FT...ALTHOUGH AN ISOLATED 3 FTER IS POSSIBLE NEAR THE 20NM
BOUNDARY LATE TONIGHT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...NO ADVISORY OR CAUTIONARY FLAGS EXPECTED ON
THE WATERS TUESDAY AND WEDNESDAY...ALTHOUGH WATERS WILL BECOME A
BIT BUMPY AS NE WINDS INCREASE DUE TO HIGH PRESSURE BUILDING FROM
THE NORTH ON TUESDAY...BECOMING SITUATED MORE OVERHEAD WITH EASING
WIND WEDNESDAY. 2-3 FOOT SEAS EXPECTED BUT UP TO 4 FEET OFFSHORE
NORTH OF CAPE FEAR AND AROUND NORTHERN FRINGES OF THE FRYING PAN
SHOALS/BAR. THE STRONGEST WINDS AND HIGHEST SEAS CAN BE EXPECTED
TUESDAY AFTERNOON INTO EVENING AS THE HIGH BUILDS SOUTH TOWARD OUR
COAST. NO TSTMS ON THE 0-20NM WATERS THROUGH THE PERIOD ALTHOUGH A
FEW TSTMS MAY BE ONGOING OVER THE GULF STREAM EARLY TUESDAY. SEAS
WILL BE MADE UP OF 2 FT ESE WAVES EVERY 8-10 SECONDS MIXED WITH
1-2 FT E WAVES IN 5-6 SECOND INTERVALS.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 230 PM MONDAY...BROAD SOUTHERLY FLOW WILL BE FOUND ACROSS
ALMOST THE ENTIRE EASTERN HALF OF THE NATION ON THURSDAY AS LARGE
HIGH SITS OVER THE WEST ATLANTIC AND A COLD FRONT PRESSES EAST
ACROSS THE NATIONS MIDSECTION. BUILDING SEAS WILL BE COMPRISED OF
AN 11 SEC SE SWELL AND A LATE DAY/NIGHTTIME BUILDING WIND WAVE
THAT COULD EVENTUALLY YIELD ADVISORY-LEVEL SEAS. AS THE SLOW
MOVING FRONT APPROACHES FROM THE WEST ON FRIDAY THE GRADIENT WILL
BE FURTHER TIGHTENING AND THE WIND FORECAST MAY RISE A CATEGORY
INTO THE 20 TO 25KT RANGE ESPECIALLY OVER NORTHERN ZONES. A WELL
PRONOUNCED VEER ASSOCIATED WITH LATE FRIDAY NIGHT FRONTAL PASSAGE
TURNS THE WINDS FROM COAST-PARALLEL TO ALMOST PERPENDICULAR
OFFSHORE. THIS OPENS UP A NEARSHORE/OFFSHORE GRADIENT IN WAVE
HEIGHTS AS THE NEAR SHORE SEAS DIMINISH QUICKLY FROM LANDMASS
SHADOWING. FURTHER FROM SHORE SEAS WILL EASE WITH LESS RAPIDITY
BUT EASE NONETHELESS AS THE GRADIENT WEAKENS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...MJC
LONG TERM...MBB
AVIATION...DL/JDW
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
150 PM EDT MON OCT 28 2013
.SYNOPSIS...
LOW PRESSURE PASSES SOUTH OF THE AREA EARLY THIS EVENING. A WARM
FRONT MOVES NORTHWARD TUESDAY NIGHT AND WEDNESDAY...BRINGING MILDER
AIR. STRONG COLD FRONT WITH SHOWERS THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
1015 AM UPDATE. INCREASED POPS ACROSS THE SOUTH HALF OF THE AREA PER
RADAR...SATELLITE...AND HI RES MODEL TRENDS. WENT WITH CAT POPS
ACROSS SOUTHWEST VIRGINIA AND SOUTHERN WEST VIRGINIA...ALTHOUGH QPF
WILL GENERALLY BE LESS THAN THE A TENTH OF AN INCH. SUNSHINE
PREVAILS ACROSS THE NORTH.
630 AM UPDATE...
HAD TO NUDGE THE N EDGE OF CLD SHIELD UP THIS MORNING TO INCLUDE
HTS TO CRW CORRIDOR...PERHAPS EVEN N OF THERE PER LATEST RUC.
OTHERWISE...NO MAJOR CHANGES. STILL LOOKING FOR SHRA ACROSS SW VA
AND SE WV TDY.
PREVIOUS DISCUSSION BELOW...
NOT MUCH CHANGE IN FCST THINKING FROM DAY SHIFT. DID ELECT TO BUMP
UP POPS ACROSS SW VA INTO LKLY MID TO LATE MORNING PER LATEST MDL
RUNS. TIGHT POP GRADIENT WITH CHC GETTING INTO COAL FIELDS TO SE
WV...WITH NOTHING N OF THERE. ALSO LOOKING AT A TIGHT GRADIENT TO
SKY GRIDS AS WELL. WENT WITH SOLID OVC ACROSS SW VA AND S WV TDY.
HARD TO SAY IF OVC REACHES AS FAR N AT HTS TO CRW CORRIDOR. DID
ALLOW FOR BKN COVERAGE THOUGH WITH CIRRUS ACROSS SE OH AND N WV.
UPR LVL DISTURBANCE RESPONSIBLE FOR WX TDY SHIFT E OF CWA THIS
AFTN AND BEGIN TO QUICKLY RAMP DOWN POPS THIS AFTN ACROSS S ZONES.
ABUNDANCE OF LLVL MOISTURE WILL LINGER THOUGH THROUGH THIS AFTN
AND A GOOD CHUNK OF THE NIGHT ACROSS S WV/SW VA...THUS KEPT
PESSIMISTIC SKY COVERAGE ACROSS THOSE LOCALES WITH SOME CIRRUS
ELSEWHERE.
INGESTED LATEST HRRR AS A BASE FOR TEMPS TDY AND
TONIGHT...TWEAKING S ZONES FOR COOLER WX PER CLDS/SHRA THREAT.
TRIED TO GO TOWARD WARMER MET ACROSS SE OH AND N WV WHERE AT LEAST
FILTERED SUN WILL BE REALIZED. SAME GENERAL THINKING HOLDS TONIGHT
AS WELL...WITH WARMER READINGS ACROSS SW VA AND S WV...WITH COOLER
READINGS FOR SE OH AND N WV.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
NAM IS MUCH STRONGER WITH A FEATURE TUESDAY NIGHT THAN OTHER
MODELS...BUT MUCH OF THIS ENERGY CAN BE TRACED BACK TO CONVECTIVE
FEEDBACK IN THE MID WEST. THEREFORE...WILL KEEP POPS LOW AS GFS
WOULD KEEP MOST PRECIPITATION TO OUR NORTHWEST. MODELS ARE FAIRLY
CONSISTENT WITH A COLD FRONT MOVING THROUGH THURSDAY NIGHT.
THEREFORE...WILL RAISE POPS THURSDAY NIGHT...AND REMOVE POPS BEHIND
FRONT FRIDAY AFTERNOON AND EVENING.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
GENERALLY FOLLOWED WPC THINKING WITH THE EXTENDED PORTION OF THE
FORECAST...WITH A LEANING TOWARDS THE EC/CMC PER ENSEMBLE SUPPORT.
UPPER RIDGE AXIS OVER THE FORECAST AREA AT THE OUTSET OF THE PERIOD
WILL QUICKLY PUSH OFF TO THE EAST WITH A POTENT SYSTEM PUSHING OUT
OF THE CENTRAL ROCKIES TOWARDS THE UPPER MIDWEST...AND SFC COLD
FRONT MARCHING EASTWARD ACROSS THE MISS VALLEY. BASED ON THE SLOWER
PROGRESSION OF NWP CONSENSUS...LOOKS LIKE THURSDAY WILL BE WARM WITH
THE BULK OF THE PRECIP HOLDING OFF UNTIL THURSDAY NIGHT AND FRIDAY
MORNING WITH THE COLD FRONT. PRECIP EXITS TO THE EAST FRIDAY
AFTERNOON...BUT SW FLOW ALOFT CONTINUES OVER THE AREA AS UPPER
TROUGH CONTINUES TO DIG ACROSS THE GREAT LAKES AND OHIO RIVER
VALLEY. AS THE TROUGH MOVES OVERHEAD SATURDAY...WILL CONTINUE SLIGHT
CHANCE POPS MAINLY ACROSS THE NORTHERN ZONES AND EASTERN MOUNTAINS.
FLOW TURNS NORTHWEST BEHIND THE TROUGH AXIS ON SUNDAY YET WITH SOME
LLVL MOISTURE TRAPPED...WILL KEEP THE SLIGHT CHANCE POPS IN ROUGHLY
THE SAME LOCATIONS AS SATURDAY. TEMPERATURES WILL BE PROGRESSIVELY
COOLER WITH EACH PASSING DAY THROUGH THE EXTENDED...DROPPING FROM
THE LOWER 70S LOWLANDS ON THURSDAY TO AROUND THE 50 DEGREE MARK BY
SUNDAY FOR THE LOWLANDS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
18Z MONDAY THRU 18Z...
THRU 00Z...UPR LVL SYS WILL PASS S OF AREA THIS AFTERNOON...WITH
SHRA EXPECTED FOR SW VA AND SRN WV THRU 00Z. EXCEPT FOR IFR FAR
SOUTH...GENERALLY KEPT MVFR GOING THIS AFTERNOON IN THE SOUTH WHERE
SHOWERS OCCUR...INCLUDING BKW. ELSEWHERE...VFR. DECREASING VFR
CLOUDS THE FARTHER NORTH YOU GO...WITH SCT CLOUDS NORTH OF A 3I2 TO
W22 LINE.
AFTER 00Z...UPPER LVL SYS EXITS THIS EVENING...TAKING SHOWERS WITH
IT BY 03Z. HOWEVER ABUNDANT LLVL MOISTURE WILL REMAIN ACROSS SW VA
AND S WV TONIGHT WHICH MAY HOLD IN MVFR/IFR CIGS. OTHERWISE...WHERE
SKIES CLEAR...ALONG AND NORTH OF A HTS-CRW-EKN LINE...BECOMING IFR
IN FOG BY 08Z.
13Z-15Z...BECOMING VFR ALL LOCATIONS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATIVE SCENARIOS: FOG FORMATION HIGHLY DEPENDS ON CLOUD COVER.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H M
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z TUESDAY...
IFR OR WORSE IN RVR VALLEY FG POSSIBLE TUES MORNING ACROSS SE OH/N
WV. IFR POSSIBLE IN SHOWERS THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/JMV/50/30
NEAR TERM...JMV/30
SHORT TERM...RPY
LONG TERM...ARJ
AVIATION...JMV
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
153 PM EDT MON OCT 28 2013
.SYNOPSIS...
A COLD FRONT EXTENDED ACROSS THE GREAT LAKES TO A LOW IN
THE CENTRAL ROCKIES THIS MORNING...WHILE WEAK HIGH PRESSURE WAS OVER
THE SOUTHEAST UNITED STATES. THE FRONT WILL MOVE SOUTHEAST AND
DISSIPATE TODAY AND TONIGHT. TUESDAY AND WEDNESDAY THE LOW WILL MOVE
FROM THE CENTRAL PLAINS INTO THE WESTERN GREAT LAKES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM EDT MONDAY...
INCREASED POPS AND EASTWARD EXTENT OF COVERAGE FOR THIS
AFTERNOON INTO TONIGHT. ADJUSTED TEMPERATURES WITH OBS AND MODEL
TRENDS.
AS OF 950 AM EDT MONDAY...
THIS MORNING KFCX 88D SHOWED LIGHT RETURNS MOVING EAST ACROSS THE
SCOPE. THE 12Z/8AM RNK SOUNDING INDICATED SHALLOW MOISTURE UP TO
775 MB WITH A WEST TO NORTHWEST FLOW AND PWAT AT 0.55 INCHES.
ADJUSTED TEMPERATURES AND DEW POINTS WITH LATEST OBS AND MODEL
TRENDS. SHAPED POP AND WEATHER WITH LATEST RADAR AND MODEL TREND.
LEANED POPS TOWARDS THE RNK WRF ARW FOR LATE THIS MORNING INTO
AFTERNOON.
AS OF 515 AM EDT MONDAY...
A WEAK STATIONARY BOUNDARY AT THE SURFACE WAS OVER THE TENNESSEE
VALLEY AND WAS THE LEADING EDGE OF WARMER AIR AND HIGHER DEW POINTS.
WATER VAPOR LOOP SHOWED AN UPPER LOW IN NORTHEAST MISSISSIPPI. THIS
LOW WILL MOVE EAST INTO THE CAROLINAS BY LATE TONIGHT.
AS SURFACE DEW POINTS RISE INTO THE 40S AND 50S AND THE AIR MASS
SATURATES...THE PROBABILITY OF PRECIPITATION GOES UP BUT AMOUNTS WILL
REMAIN LIGHT. HAVE INCREASED PROBABILITY OF PRECIPITATION IN THE
SOUTHWEST COUNTIES OF THE FORECAST AREA WHERE MOST OF THE GUIDANCE
IS SHOWING SOME RAIN FOR TODAY BUT HAVE DELAYED THE START TIME.
LOCAL WRF AND RAP GUIDANCE HAVE THE BEST CHANCE OF RAIN MOVING INTO
THE COUNTY WARNING AREA AFTER 13Z/9AM.
CLOUDS WILL ADVANCE INTO THE AREA AHEAD OF THE RAIN. SATELLITE
PICTURES SHOWED LEADING EDGE ALREADY UP TO A BLUEFIELD TO DANVILLE
LINE. WITH CLOUD COVER EXPECTED MUCH OF THE DAY IN THIS SOUTHWEST
PART OF THE FORECAST AREA...HAVE GONE A COUPLE OF DEGREES BELOW
GUIDANCE FOR MAXIMUM TEMPERATURES. USED A BLEND OF BIAS CORRECTED
MAV/MET GUIDANCE FOR OVERNIGHT LOWS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM EDT MONDAY...
UPPER LEVEL RIDGING ACROSS THE EASTERN HALF OF THE NATION WILL
RESULT IN UNSEASONABLY WARM TEMPERATURES FOR THE MIDDLE OF THE
WORKWEEK. WILL START TUESDAY OFF WITH A WEAK COLD FRONT SINKING
SOUTHWARD ACROSS OUR AREA...WHILE HIGH PRESSURE BUILDS IN BEHIND...
HUGGING THE EASTERN FACE OF THE APPALACHIANS. NORTHEASTERLY WINDS
AROUND THE HIGH WILL CARRY COOLER AIR FROM THE ATLANTIC...AND
THEREFORE HAVE UNDERCUT MODEL GUIDANCE A COUPLE OF DEGREES FOR
AFTERNOON HIGHS. ALSO KEPT A SLIGHT CHANCE OF SHOWERS IN THE
FORECAST FOR THE MORNING AND AFTERNOON AS THE FRONT STALLS JUST
SOUTH OF OUR AREA...BUT BELIEVE THIS ACTIVITY WILL REMAIN ISOLATED
AND MAINLY IN THE FORM OF SPRINKLES WHERE IT DOES OCCUR.
WINDS WILL QUICKLY SHIFT SOUTHWESTERLY TUESDAY NIGHT AS HIGH
PRESSURE SLIDES OFFSHORE...AND A DEEP LOW PRESSURE SYSTEM DEVELOPS
OVER THE CENTRAL PLAINS. THE STALLED FRONT WILL LIFT BACK TO THE
NORTH AS A WARM FRONT WEST OF THE APPALACHIANS...BUT WILL BE SLOWER
TO LIFT NEAR OUR AREA...AND WILL THEREFORE PROVIDE THE FOCUS OF MORE
SPOTTY SHOWER ACTIVITY. BELIEVE THESE SHOWERS WILL OCCUR IN WAVES AS
WEAK UPPER LEVEL DISTURBANCES RIDE ALONG THE FRONT FROM THE WEST...
WITH BETTER RAIN CHANCES FOUND NORTH OF INTERSTATE 81. THE WARM
FRONT WILL FINALLY LIFT NORTH OF OUR AREA WEDNESDAY EVENING...
BRINGING A LULL IN THE SHOWER ACTIVITY AS THE LOW PRESSURE SYSTEM
APPROACHES THE GREAT LAKES...DRAGGING A STRONG COLD FRONT ACROSS THE
PLAINS.
SHOWER ACTIVITY WILL INCREASE ON THURSDAY AFTERNOON AND EVENING AS
THE COLD FRONT MOVES EAST OF THE MISSISSIPPI RIVER...BUT BELIEVE THE
HEAVIEST AND MOST WIDESPREAD RAIN WILL OCCUR AFTER MIDNIGHT EARLY
FRIDAY MORNING AS THE SUPPORTING UPPER LEVEL TROUGH MOVES ACROSS THE
AREA. MOST MODELS ARE IN GOOD AGREEMENT WITH TIMING OF THE FRONT...
AND THERE HAS BEEN GOOD MODEL RUN TO RUN CONSISTENCY OVER THE PAST
DAY...SO FEEL COMFORTABLE GOING WITH HIGH RAIN CHANCES FOR EARLY
FRIDAY. WHILE CAPE IS MINIMAL...MODELS AGREE THAT THE 50+ KT LOW
LEVEL JET WILL SUPPORT HIGH SHEAR AND HELICITY VALUES ACROSS OUR
AREA...MEANING THAT WHILE WE MAY NOT OBSERVE MUCH LIGHTNING IN THE
CONVECTION...THE HEAVIER SHOWERS MAY PULL SOME OF THE STRONGER WINDS
ALOFT DOWN TO THE SURFACE...RESULTING IN GUSTY AND LOCALLY DAMAGING
WINDS. THE HIGH SHEAR AND HELICITY ALSO MEANS WE CANNOT RULE OUT AN
ISOLATED SPIN UP TORNADO.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 400 AM EDT MONDAY...
THE COLD FRONT WILL SLIDE EAST ACROSS THE AREA FRIDAY AFTERNOON AND
REACH THE ATLANTIC COAST FRIDAY NIGHT INTO SATURDAY MORNING. LEANED
ISC GRIDS TOWARDS THE SLOWER ECMWF WITH COLD FRONT OVER THE QUICKER
GFS SOLUTION. IN THE WAKE OF THE COLD FRONT...HIGH PRESSURE WILL
BUILD EAST ACROSS OUR REGION SATURDAY. BY SATURDAY NIGHT THE
COMBINATION OF NORTHWEST FLOW AND A SHORTWAVE WILL CREATE UPSLOPE
RAIN AND SNOW SHOWERS ACROSS THE FAVORED UPSLOPE REGION IN THE WEST.
HIGH PRESSURE BUILDS EAST INTO THE REGION SUNDAY...ENDING ANY
UPSLOPE PRECIPITATION IN THE WEST. COOLING TREND EXPECTED IN THE
TEMPERATURES FOR THE WEEKEND AS UPPER TROUGH SLIDE ACROSS EAST COAST.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 150 PM EDT MONDAY...
MVFR SCT TO BKN CLOUDS WITH POCKETS OF IFR AND LIFR IN RAIN AND
DRIZZLE EXPECTED THIS AFTERNOON INTO TONIGHT FOR THE WEST. WHILE
IN THE EAST...VFR CONDITIONS ANTICIPATED WITH ISOLATED MVFR
CLOUDS POSSIBLE IN RAIN.
AN UPPER LEVEL DISTURBANCE WILL TRACK EAST ACROSS THE REGION THIS
AFTERNOON INTO TONIGHT. LOWER CLOUDS WILL TRY AND CLEAR
OVERNIGHT INTO TUESDAY MORNING. THERE MAY BE AREAS OF FOG
ESPECIALLY AT KLWB OVERNIGHT DEPENDING ON HOW FAST IT CLEARS.
MEDIUM CONFIDENCE IN CEILINGS AND VISIBILITY DURING THE TAF
PERIOD. HIGH CONFIDENCE IN WINDS DURING THE TAF PERIOD.
MAINLY VFR CONDITIONS ARE EXPECTED TUESDAY THROUGH THURSDAY IN
ADVANCE OF AN APPROACHING COLD FRONT. LOW LEVEL SOUTH WINDS WILL
BE STEADILY INCREASING DURING THIS PERIOD.
MODEL GUIDANCE VARIES AS TO THE TIMING OF THE PASSAGE OF A COLD
FRONT. CURRENTLY LOOKING AT SOMETIME ON THURSDAY NIGHT TO FRIDAY.
THE PASSAGE OF THE FRONT WILL BRING SUB-VFR CONDITIONS ALONG AND
AHEAD OF THE BOUNDARY WITH SHOWERS AND GUSTY WINDS.
IN THE WAKE OF THE COLD FRONT...LOOK FOR INCREASING NORTHWEST FLOW
BEHIND THE SURFACE SYSTEM. THIS SCENARIO WILL LIKELY PLACE
UPSLOPE RAIN/SNOW SHOWERS ACROSS THE PREFERRED UPSLOPE REGIONS OF
SOUTHEAST WEST VIRGINIA SATURDAY INTO SUNDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/KK
NEAR TERM...AMS/KK
SHORT TERM...NF
LONG TERM...KK
AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
320 PM MDT MON OCT 28 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 330 PM MDT MON OCT 28 2013
SEVERAL FORECAST CHALLENGES WITH THIS FORECAST PACKAGE...INCLUDING
FREEZING DRIZZLE AND DENSE FOG THIS AFTERNOON THROUGH TUESDAY
MORNING AS WELL AS A POSSIBLE HEAVY SNOW EVENT TUESDAY NIGHT INTO
WEDNESDAY MORNING.
CURRENTLY...LATEST WATER VAPOR IMAGERY SHOWING A CLOSED LOW
ROTATING OVER CENTRAL NEVADA THIS AFTERNOON. IR IMAGERY SHOWING
SOME ENERGY BEING SPUN OFF THE LOW WHICH IS EJECTING INTO
SOUTHWESTERN WYOMING AND WESTERN COLORADO ATTM. LOOKS FAIRLY
UNSTABLE OUT THAT WAY AND WE HAVE SEEN SOME LIGHTNING STRIKES
RECENTLY OVER NEVADA AND EARLIER IN UTAH FROM THAT ENERGY MOVING
INTO SOUTHWEST WYOMING. CLOSER TO HOME...THE SURFACE BOUNDARY
CURRENTLY EXTENDS FROM NEAR DENVER...OUT ACROSS NORTHEASTERN
UTAH...NORTH THROUGH IDAHO AND UP INTO BRITISH COLUMBIA. VERY
ESTABLISHED NORTHEASTERLY WIND FLOW ACROSS THE PANHANDLE...ALL THE
WAY TO RAWLINS THIS AFTERNOON. EXPANSIVE AREA OF STRATUS FROM
SOUTH OF DENVER NORTH INTO SOUTHERN MONTANA. WE HAVE BEEN
EXPERIENCING DENSE FOG AND FREEZING DRIZZLE MOST OF THE DAY.
TEMPERATURES HAVE STRUGGLED WITH THIS NORTHEAST FLOW AND DENSE
STRATUS...STILL ONLY 26 HERE AT CHEYENNE...28 AT DOUGLAS AND LOW
30S OUT IN THE PANHANDLE.
WENT AHEAD AND ISSUED A DENSE FOG ADVISORY FOR AREAS ALONG THE
EAST SLOPES OF THE LARAMIE RANGE FOR THE REST OF THE AFTERNOON AND
OVERNIGHT. LATEST NAM SOUNDING CONTINUE TO SHOW DEEP LOW LEVEL
MOISTURE PERSISTING THROUGH THE OVERNIGHT HOURS. GFS AND NAM
SOUNDINGS SHOWING THE WINDS SHIFTING SOUTHEASTERLY THROUGH THE
AFTERNOON...BUT SO FAR...NORTHEAST WINDS REMAIN IN PLACE. DO NOT
THINK THAT WILL CHANGE ANY AS THE RUC SHOWS NORTHEASTERLY WINDS
PERSISTING. WELL ESTABLISHED FREEZING DRIZZLE PROFILES PERSIST
EAST OF THE LARAMIE RANGE AS WELL. SO WILL KEEP THE FREEZING
DRIZZLE ADVISORY GOING AS SCHEDULED. COULD GET PRETTY NASTY EAST
OF THE LARAMIE RANGE AFTER SUNSET AS TEMPERATURES CONTINUE TO COOL
INTO THE LOW TO MID 20S BY EARLY TUESDAY MORNING. WOULD NOT BE
SURPRISED TO SEE QUITE A BIT OF BLACK ICE ACROSS OUR CWA EAST OF
THE LARAMIE RANGE. BE CAREFUL OUT THERE IF YOU ARE TRAVELING
TONIGHT AND TUESDAY MORNING.
BY MID TUESDAY MORNING...UPPER LOW FORECAST TO TRACK INTO WESTERN
WYOMING. THIS SHOULD SHIFT LOW LEVEL WINDS MORE SOUTHEASTERLY.
STRATUS LIKELY TO CONTINUE IN THIS SOUTHEASTERLY FLOW...BUT THE
DENSE FOG AND FREEZING DRIZZLE SHOULD EASE AS TEMPERATURE RISE.
STILL...A COOL DAY IN STORE FOR TUESDAY...WITH HIGHS IN THE LOW
40S EAST OF THE LARAMIE RANGE TO LOW 30S OVER THE NORTHERN
PANHANDLE. DID SHAVE A FEW DEGREES OFF GUIDANCE TO ACCOUNT FOR THE
STRATUS.
FINALLY TUESDAY NIGHT INTO WEDNESDAY...MODELS IN GOOD AGREEMENT
WITH SOME MID LEVEL FRONTOGENESIS DEVELOPING AHEAD OF THE EJECTING
LOW. GFS PAINTING A .6 INCH QPF BULLSEYE OVER THE SOUTHERN
PANHANDLE BACK TO CHEYENNE. LATEST ECMWF GUIDANCE SHOWING AROUND 0.4
INCHES OVER LARAMIE COUNTY EXTENDING UP INTO THE CENTRAL
PANHANDLE...WHILE THE NAM SHOWS SOMETHING SIMILAR TO THE
ECMWF...ONLY A LITTLE LIGHTER ON PRECIP AMOUNTS. USING NAM
TEMPERATURE PROFILES...THIS PRECIP COULD FALL AS ALL SNOW WHILE
THE GFS SHOWING A MUCH WARMER SCENARIO. LATER SHIFTS WILL NEED TO
TRY TO NAIL DOWN A GOOD LOCATION FOR THE BANDING PRECIP
DEVELOPMENT. WOULD THINK WE WOULD NEED AT LEAST A WINTER WEATHER
ADVISORY OUT FOR THE AREA ONCE THE AREA HAS BEEN
IDENTIFIED...MAYBE EVEN A SHORT FUSED WARNING IF THE GFS QPF
FORECAST COMES TRUE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 330 PM MDT MON OCT 28 2013
LONG RANGE MODELS IN GOOD AGREEMENT THROUGH THE WEEKEND...SHOWING
THE UPPER LEVEL LOW BECOMING AN OPEN WAVE TROUGH AND EXITING THE
REGION TO THE EAST WEDNESDAY NIGHT. EXPECT PRECIP TO GRADUALLY
COME TO AN END BEHIND THE TROUGH AXIS FOR MOST AREAS OUTSIDE OF
THE MOUNTAINS LATE WEDNESDAY NIGHT. MODELS SHOW DECENT UPSLOPE
FLOW AND MOUNTAIN SNOW SHOWERS THROUGH FRIDAY AS SEVERAL WEAK
SHORTWAVES PUSH ACROSS THE AREA EMBEDDED IN BROAD NORTHWEST FLOW
ALOFT. THE PRIMARY FORECAST CONCERN LATER THIS WEEK IS THE
POTENTIAL FOR STRONG GUSTY WINDS ACROSS PORTIONS OF SOUTHEAST
WYOMING. LOOKS LIKE A CLASSIC GAP WIND CASE WITH 700MB WINDS
APPROACHING 50 KNOTS ALONG THE I80 CORRIDOR ALONG WITH AN
INCREASING PRESSURE GRADIENT ALONG THE FRONT RANGE. LOOKS LIKE
HIGHER ELEVATIONS AND THE WIND PRONE AREAS MAY RECEIVE GUSTS UP
TO 60 MPH...ALTHOUGH IT WILL BE PRETTY WINDY ACROSS THE LOWER
ELEVATIONS OF SOUTHEAST WYOMING INTO THURSDAY AS WELL...WITH WESTERLY
WINDS SUSTAINED BETWEEN 20 TO 35 MPH AND GUSTING UP TO 50 MPH.
WITH NORTHWEST FLOW ALOFT...DO NOT EXPECT TEMPERATURES TO INCREASE
TOO MUCH THIS WEEK. HIGHS WILL GENERALLY REMAIN IN THE 40S TO LOW
50S ACROSS THE FORECAST AREA.
ALL MODELS INDICATE THE UPPER LEVEL FLOW BACKING INTO THE
SOUTHWEST BY NEXT WEEKEND AS AN UPPER LEVEL RIDGE AXIS FLATTENS
AND THEN MOVES ACROSS THE AREA. THIS WILL ALLOW TEMPERATURES TO
MODERATE INTO THE 50S TO LOW 60S ACROSS THE AREA. MODELS INDICATE
ANOTHER PACIFIC STORM SYSTEM AND ASSOCIATED COLD FRONT MOVING
ACROSS THE PAC NORTHWEST THIS WEEKEND. THIS SYSTEM WILL EVENTUALLY
PUSH EASTWARD INTO THE NORTHERN AND CENTRAL ROCKYS BY SUNDAY AND
MONDAY. THIS STORM SYSTEM HAS THE POTENTIAL TO BRING MUCH COLDER
AIR TO SOUTHEAST WYOMING AND WESTERN NEBRASKA FOR EARLY NEXT
WEEK...WITH THE ADDITION OF ACCUMULATING SNOWFALL. DUE TO TIMING
DIFFERENCES...ONLY INCREASED POP TO NEAR 20 PERCENT ACROSS
SOUTHEAST WYOMING ON MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY MORNING)
ISSUED AT 1152 AM MDT MON OCT 28 2013
A PROLONGED IFR/LIFR EVENT IS EXPECTED ACROSS THE HIGH
PLAINS...MAINLY EAST OF THE LARAMIE RANGE INCLUDING KCYS AND ALL OF
THE WESTERN NEBRASKA PANHANDLE. WARM AIR WILL OVERRUN MUCH COLDER
UPSLOPE FLOW NEAR THE SURFACE INTO TONIGHT PRODUCING FREEZING
FOG...FREEZING DRIZZLE AND A MIX OF SLEET AND FREEZING RAIN AT
TIMES. IN ADDITION TO THE LOW CIGS AND VIS...ICING WILL BE A
CONCERN AT ALL EASTERN TERMINALS WITHIN THE LOW CIGS. FURTHER WEST
NEAR KRWL AND KLAR...MAINLY VFR CONDITIONS WITH PERIODS OF MVFR
CIGS LIKELY NEAR AFTERNOON CONVECTION.
CONDITIONS MAY BRIEFLY IMPROVE AROUND 21Z...BUT DENSE FOG AND LIFR
CONDITIONS WILL RETURN AROUND SUNSET ACROSS THE EASTERN PLAINS.
FREEZING DRIZZLE AND FOG ARE A GOOD POSSIBILITY WITH AIRCRAFT ICING
REMAINING A BIG CONCERN TONIGHT AS WELL.
&&
.FIRE WEATHER...
ISSUED AT 330 PM MDT MON OCT 28 2013
LOW PRESSURE OVER SOUTHERN NEVADA IS MOVING INTO SOUTHWESTERN
COLORADO LATER THIS AFTERNOON. THIS SYSTEM WILL BRING UNSETTLED
WEATHER TO THE AREA AS WELL AS COLDER TEMPERATURES AND HIGH
HUMIDITIES. THEREFORE...FIRE WEATHER CONCERNS WILL BE MINIMIZED
THROUGH WEDNESDAY. AS THE LOW EXITS EAST WEDNESDAY NIGHT...STRONG
SOUTHWEST WINDS ARE EXPECTED TO DEVELOP ACROSS SOUTHEAST WYOMING
WITH GUSTS TO 45 TO 50 MPH POSSIBLE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...FREEZING RAIN ADVISORY UNTIL NOON MDT TUESDAY FOR WYZ101-102-
106>108-117>119.
DENSE FOG ADVISORY UNTIL 6 AM MDT TUESDAY FOR WYZ101-106-107-
117>119.
NE...FREEZING RAIN ADVISORY UNTIL NOON MDT TUESDAY FOR
NEZ002-003-095- 096.
&&
$$
SHORT TERM...CLAYCOMB
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...CLAYCOMB