Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/14/14


AREA FORECAST DISCUSSION
NWS ALBANY NY
917 PM EST THU NOV 13 2014 .SYNOPSIS... FIRST MEASURABLE SNOWFALL FOR MUCH OF THE FORECAST AREA EXPECTED TONIGHT WITH ACCUMULATIONS MAINLY ON GRASSY SURFACES. SNOW IS EXPECTED TO COME TO AN END BEFORE THE MORNING COMMUTE. IN THE MEANTIME...LAKE ENHANCED SNOW WILL CONTINUE INTO THE WESTERN ADIRONDACKS. A REINFORCING SHOT OF COLD AIR WILL TAKE HOLD FRIDAY AND LAST INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... AS OF 915 PM...A BAND OF STEADY LIGHT SNOW IS PROGRESSING EASTWARD ACROSS THE MOHAWK VALLEY AND PARTS OF THE SARTAOGA REGION. IR SATELLITE IMAGERY HAS SHOW A STEADY DECREASE IN CLOUD TOP TEMPERATURES WHICH IS CAUSING THIS LIGHT SNOW BAND TO DEVELOP. THIS WILL MAKES ITS WAY THROUGH THE IMMEDIATE CAPITAL REGION IN THE NEXT COUPLE OF HOURS. PLEASE USE EXTRA CAUTION IF TRAVELING ON ROADWAYS IN THE NEXT FEW HOURS WHERE LOCALIZED SLIPPERY CONDITIONS ARE POSSIBLE. WITH THE ASSIST OF THE UPTON NEW YORK RADAR...THERE IS ALSO A SECOND AREA OF PRECIPITATION ACROSS DUTCHESS AND LITCHFIELD COUNTIES. CURRENT OBSERVATIONS IN OUR EXTREME SOUTHERN AREAS ARE STILL SHOWING RAIN SHOWERS ACROSS THE REGION BUT THIS WILL EVENTUALLY CHANGE TO SNOW. LATEST LOCAL HRRR MODEL AND RAP MODEL RUN UPDATES HAVE BEEN CONSISTENT WITH SLIGHTLY MORE QPF ACROSS THE SOUTHERN REGIONS WHERE SNOWFALL TOTALS HAVE BEEN INCREASED SLIGHTLY IN THE HIGHEST TERRAIN ACROSS THE SOUTHERN BERKSHIRES INTO THE NORTHERN LITCHFIELD HILLS WILL RANGE BETWEEN ONE TO TWO INCHES WITH ISOLATED AREAS UP TO THREE INCHES POSSIBLE BY EARLY FRIDAY MORNING. PREV DISC... SHORT WAVE IS MOVING ACROSS THE GREAT LAKES REGION INTO THE OHIO VALLEY THROUGH THE LONGWAVE TROUGH. THIS PIECE OF ENERGY IS INDUCING THE DEVELOPMENT OF A LOW OFF THE MID ATLANTIC COAST. GUIDANCE IS WELL CLUSTERED MOVING THE SURFACE LOW NORTHEASTWARD PASSING IT JUST TO THE SOUTH AND EAST OF CAPE COD AROUND 12Z/FRIDAY. THESE FEATURES WILL BRING A LIGHT SNOWFALL TO THE REGION TONIGHT...MAINLY THIS EVENING. REGIONAL RADARS ARE BLOSSOMING TO THE WEST. INITIALLY THE PRECIPITATION SHOULD START OUT A RAIN AND SNOW IN THE VALLEY WITH ALL SNOW EXPECTED BY 9-10PM. THE SNOW IS EXPECTED TO END BEFORE THE MORNING COMMUTE...BY AROUND 07Z ACROSS OUR WESTERN NEW ENGLAND COUNTIES. GENERALLY LOOKING AT LESS THAN AN INCH BELOW 1000 FEET WITH 1 TO 2 INCHES ABOVE 1000 FEET AND FOR LITCHFIELD COUNTY. LAKE ENHANCED SNOW WILL CONTINUE INTO THE WESTERN ADIRONDACKS TONIGHT AS THE SOUTHWESTERLY FLOW CONTINUES AHEAD OF APPROACHING TROUGH. TEMPERATURES ARE EXPECTED TO DROPPED INTO MAINLY THE 20S OVERNIGHT. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... FLOW ACROSS REGION WILL SHIFT TO THE NORTHWEST AS THE LOW MOVES NORTHEAST AWAY FROM THE REGION. ALOFT THE UPPER TROUGH AXIS WILL SWING THROUGH MAINLY DURING THE MORNING AND CYCLONIC WILL SET UP ACROSS THE REGION. COLDER AIR MASS WILL BLANKET REGION WITH 850 MB TEMPERATURES DROPPING TO -10 TO -12 DEGREES CELSIUS ACROSS THE FORECAST AREA. WITH THIS COLD AIR MOVING ACROSS THE GREAT LAKES LAKE EFFECT CLOUDS AND SHOWERS IMPACTING PORTIONS OF THE FORECAST AREA...MAINLY THE WESTERN MOHAWK VALLEY INTO THE EASTERN CATSKILLS. THE LAKE EFFECT WILL DIMINISH SATURDAY AND SHOULD COME TO AN END BY SATURDAY NIGHT AS RIDGING BUILDS IN. THE RIDGE`S VISIT WILL BE BRIEF AS IT MOVES QUICKLY OFFSHORE SATURDAY NIGHT AHEAD OF THE NEXT SYSTEM. COLD WITH TEMPERATURES RUNNING 10 TO 15 DEGREES BELOW NORMAL. && .LONG TERM /SUNDAY THROUGH THURSDAY/... A VERY ACTIVE AND CHILLY PATTERN SETTING UP FOR THE LONG TERM PERIOD AS A VIGOROUS UPPER TROUGH /POLAR VORTEX/ DIVES SOUTHWARD AND EASTWARD OF THE CONTINENTAL DIVIDE. MONDAY...PLENTY OF MODEL DISCREPANCIES REMAIN AS THE ECMWF REMAINS ON THE WARMER SIDE OF THE GUIDANCE ENVELOPE WITH THE GGEM/GFS ON THE COLDER SIDE. IN ADDITION...THE GGEM IS STRONGER WITH THE COASTAL WAVE REFLECTION AS OPPOSED TO THE FLATTER AND FASTER WAVE OF THE GFS WITH THE ECMWF SOMEWHAT IN THE MIDDLE. AT THIS TIME...AND PER COLLABORATION WITH WPC...WE WILL LEAN TOWARD THE MORE STABLE ECMWF. THIS WOULD RESULT THE CHANCE FOR ACCUMULATING SNOW FOR THE HIGHER TERRAIN NORTH AND WEST OF ALBANY WITH MAINLY RAIN /PERHAPS A LITTLE SNOW MIX/ SOUTH AND EAST OF ALBANY. FOR NOW...WE WILL HAVE HIGH CHANCE POPS UNDER A CLOUDY SKY. WPC GUIDANCE TEMPS ARE A GREAT COMPROMISE WITH LEANING TOWARD A SLIGHTLY COLDER SOLUTION DUE TO WET BULB PROCESS. MONDAY NIGHT THROUGH WEDNESDAY...WHAT WAVE DOES DEVELOP WILL QUICKLY TRACK TO THE NORTHEAST MONDAY EVENING. COLD AIR ADVECTION AND DEEP CYCLONIC FLOW WILL RESULT IN LAKE EFFECT ACTIVITY DEVELOPING DOWNWIND OF LAKE ONTARIO WHICH WILL BE THE MAIN WEATHER STORY FOR THE REMAINDER OF THE LONG TERM PERIOD. OTHERWISE...BELOW NORMAL TEMPERATURES AS H850 TEMPS ARE AT OR BELOW -10C AND MAINLY CLOUD COVERAGE INTO THE TERRAIN WITH UPSLOPE CONDITIONS. MORE CLEARING WILL TAKE PLACE DOWNWIND OF THE TERRAIN...ESPECIALLY IN THE MID HUDSON VALLEY. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... PERIOD OF LIGHT WINTRY MIXTURE CHANGING TO MAINLY SNOW TONIGHT FOR TAF SITES. THE INITIAL VFR CONDITIONS WILL GRADUALLY DETERIORATE TO MVFR LATER THIS EVENING. THERE COULD BE A PERIOD OF IFR CONDITIONS AT KPOU AS BANDED PRECIP MAY LIMIT BOTH VIS AND CIGS. OVERNIGHT...THE COASTAL SYSTEM WILL RAPIDLY PULL AWAY AS IMPROVING CONDITIONS WILL OCCUR WITH RESPECT TO DIMINISHING SNOW AND IMPROVING VISIBILITIES. HOWEVER...CIGS WILL REMAIN AT OR WITH MVFR RANGE THE REMAINDER OF THE NIGHT. DURING FRIDAY...WEST-NORTHWEST WINDS WILL INCREASE WHICH WILL ASSIST WITH CIGS BREAKING UP TO VFR CONDITIONS. HOWEVER...UPSLOPE CONDITIONS FOR KPSF MAY HOLD ONTO THE BKN CIGS A BIT LONGER. OUTLOOK... FRI NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. SAT-SAT NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUN: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN. SUN NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN. MON: HIGH OPERATIONAL IMPACT. LIKELY RA...SN. MON NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... NO HYDROLOGIC PROBLEMS ARE EXPECTED INTO EARLY NEXT WEEK. MAINLY LIGHT AND FROZEN PRECIPITATION INTO THE WEEKEND. A STORM SYSTEM WILL IMPACT THE REGION TO END THE WEEKEND AND START THE NEW WORK WEEK. THERE IS MUCH UNCERTAINTY WITH THE SYSTEM...REFER TO THE LONG TERM DISCUSSION FOR DETAILS. 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...IAA NEAR TERM...LFM SHORT TERM...IAA LONG TERM...BGM AVIATION...ELH HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS POCATELLO ID
842 PM MST THU NOV 13 2014 .UPDATE...MOIST FLOW REMAINS DRAPED OVER EAST IDAHO WITH COLD LOW TO THE NORTH. WESTERLY FLOW MAINTAINING OROGRAPHIC INFLUENCE OVER CENTRAL MTNS WITH CONTINUED WEAK IMPULSES PULLING SNOW THROUGH THE MAGIC VALLEY TO THE LOWER SNAKE PLAIN INTO THE EASTERN HIGHLANDS. SNOWFALL TOTALS REMAIN ON TARGET SO FAR. IN ADDITION...KTWF HAS CHANGED TO FREEZING RAIN...AND RIGHT ON TIME PER EARLIER MODEL RUNS. TEMPS IN THE MAGIC VALLEY STILL VERY COLD...AND WOULD EXPECT CHANGE OVER AT KBYI WITHIN THE NEXT FEW HOURS. TIMING PER LOCAL WRF AND HRRR STILL WITHIN A COUPLE HOURS EITHER SIDE OF 12Z FOR KPIH. NEXT STRONG PUSH OF PRECIP ASSOCIATED WITH SHORTWAVE FEATURE MOVING THROUGH OREGON INTO WESTERN IDAHO THIS EVENING...AND STILL LOOKS GOOD TIMED FOR MORNING ACROSS EAST IDAHO. NUDGED POPS UP MOST AREAS OTHER THAN THE DOWNSLOPED PORTIONS OF THE UPPER SNAKE PLAIN FOR REMAINDER OF TONIGHT. KEPT PRIOR LOCATIONS FOR FREEZING RAIN IN GRIDS...AND MADE A FEW MINOR ADJUSTMENTS TO QPF/SNOW. OVERALL SNOW TOTALS REMAIN CLOSE TO PRIOR FORECAST. WILL LEAVE ALL HEADLINES IN PLACE AS THEY STAND. DMH && .PREV DISCUSSION... /ISSUED 154 PM MST THU NOV 13 2014/ SHORT TERM...TODAY THROUGH SUNDAY. SNOW HAS PERSISTED MUCH OF MORNING AND EARLY AFTERNOON IN CENTRAL MOUNTAINS...MAGIC VALLEY...SNAKE RIVER PLAIN AND SOUTHERN MOUNTAINS. SHOULD REACH UPPER SNAKE RIVER HIGHLANDS LATER THIS AFTERNOON. WINTER WEATHER ADVISORIES REMAIN IN EFFECT FOR ALL OF SOUTHEASTERN IDAHO WITH SNOW EXPECTED TO CONTINUE OFF AND ON THROUGH FRIDAY NIGHT. DO EXPECT A CHANGE TO RAIN FRIDAY MORNING AND EARLY AFTERNOON IN EASTERN MAGIC VALLEY AND SNAKE RIVER PLAIN AS WARM AIR FINALLY MOVES IN. WITH THIS STILL COULD SEE A BRIEF PERIOD OF FREEZING RAIN FRIDAY MORNING IN THOSE LOCATIONS. DO NOT EXPECT AN EXTENDED PERIOD OF FREEZING RAIN HOWEVER WITH TEMPERATURES RISING ABOVE FREEZING QUICKLY. EVERYTHING ABOVE 5500 FEET SHOULD REMAIN SNOW THROUGH THE ENTIRE PERIOD WITH 5 TO 10 INCHES EXPECTED IN THE MOUNTAINS WITH LOCALLY HIGHER AMOUNTS ON PASSES. STILL THINK 1 TO 4 INCHES THROUGH FRIDAY MORNING STILL A GOOD AMOUNT FOR SNAKE RIVER PLAIN AND MAGIC VALLEY. ANOTHER STRONG CANADIAN COLD FRONT WILL MOVE THROUGH THE REGION FRIDAY NIGHT AND TEMPERATURES WILL AGAIN COOL DOWN SIGNIFICANTLY OVER THE WEEKEND. WITH THE BRIEF WARM UP FRIDAY TEMPERATURES WILL BE NEAR NORMAL BUT EXPECT ABOUT A 15 DEGREE DROP IN HIGH TEMPERATURES SATURDAY AND CONTINUED WELL BELOW NORMAL SUNDAY. BRUNT OF PRECIPITATION WILL END FRIDAY NIGHT WITH IT LINGERING LONGER IN EASTERN HIGHLANDS NEAR WYOMING BORDER. SHOULD BE MAINLY DRY SATURDAY AFTERNOON THROUGH SUNDAY. GK LONG TERM...SUN NIGHT THROUGH NEXT THU NIGHT. 500MB 5-WAVE PATTERN KEEPS A HIGH AMPLITUDE RIDGE TO THE WEST...KEEPING THE GEM STATE IN NORTHERLY FLOW FOR THE ENTIRE PERIOD. THUS EXPECT COLD AND DRY...ESPECIALLY EARLY IN THIS PERIOD. THE PATTERN DOES DE-AMPLIFY BY WED...MAKING PRECIPITATION A LITTLE EASIER TO RECEIVE WITH THE WEAKER RIDGE. THE ECMWF IN FACT KEEPS SHORTWAVES OUT OF THE PACIFIC NORTHWEST AND IDAHO FOR THE ENTIRE PERIOD. THE GFS ATTEMPTS TO BRING IN MOISTURE FROM THE SOUTH AS A LOW UNDERCUTS THE RIDGE AS IT APPROACHES NORTHERN CALIFORNIA. IN FACT WED WILL BE QUITE WET IF THE GFS IS TO BE BELIEVED...THU LESS SO. SINCE THIS IS THE POINT AT WHICH THE LOWER AMPLITUDE LONGWAVE RIDGE COLLAPSES...CANNOT RULE IT OUT. BUT WILL BIAS DRIER THAN THE GFS FOR NOW. WITH ALL THE NORTHERLY FLOW...TEMPERATURES WILL STAY WELL BELOW NORMAL WITH ARCTIC AIR STILL IN PLACE. ONCE AGAIN THE GFS WARMS IT UP TOWARDS THE END...BUT STILL BARELY GETTING TO NEAR NORMAL. WILL ATTEMPT TO FIND A HAPPY MIDDLE GROUND WITH THE TEMPERATURES. MESSICK AVIATION...WILL BE A TOUGH EVENING AT ALL AIRDROMES. WARM FRONT MOISTURE WILL PRODUCE LIGHT CONTINUOUS PRECIPITATION...BUT DO NOT REALLY BELIEVE THE LACK OF LOWER VISIBILITY IN THE MOS GUIDANCE. CIGS ALSO STAY FAIRLY HIGH WITH NO IFR PREDICTED. I FIND THIS HARD TO BELIEVE WHEN LOOKING AT TIME-HEIGHT CROSS SECTIONS WITH NORTHEASTERLY TO NORTHERLY FLOW IN THE FIRST PART OF THE FORECAST AND A LATER SWITCH TO SOUTHWEST. THE PRECIPITATION AFTER THE FRONT IS MUCH LIGHTER...SO THERE WILL BE BREAKS DEVELOPING LATER TONIGHT. BUT AT THAT TIME...THE OVERNIGHT COOLING WILL LIKELY KEEP STRATUS AND FOG GOING. HAVE MADE TAFS MORE PESSIMISTIC THAN GUIDANCE...SO HAVE A LOW CONFIDENCE IN TAFS THIS NEXT 24-36 HOURS. MESSICK && .PIH WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 11 AM MST FRIDAY IDZ017-020>022-024. WINTER WEATHER ADVISORY UNTIL 11 PM MST FRIDAY IDZ019-023-025. WINTER WEATHER ADVISORY UNTIL 5 PM MST FRIDAY IDZ018-031-032. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1126 PM CST TUE NOV 11 2014 .UPDATE... 901 PM CST CONSIDERABLE CLOUD COVER REMAINS ACROSS THE AREA...WITH SOME CLEARING BEGINNING TO TAKE PLACE ACROSS NORTHCENTRAL WISCONSIN. IF THIS CLEARING WERE TO CONTINUE...IT WOULD LIKELY SPREAD SOUTHEAST ACROSS OUR FORECAST AREA JUST BEFORE DAYBREAK. WITH THE CONTINUED WINDS THIS EVENING...AND LIKELY CONTINUING INTO THE OVERNIGHT PERIOD...THIS WILL RESULT IN HOLDING THE TEMPS UP A FEW DEGREES. HAVE MADE SOME ADJUSTMENTS TO THE TEMPS BEING SLIGHTLY WARMER THROUGH THE NEXT SEVERAL HOURS...HOWEVER AS CLOUD COVER BEGINS TO THIN AND WINDS DIMINISH SLIGHTLY...THIS SHOULD ALLOW TEMPS TO DROP JUST BEFORE DAYBREAK INTO THE LOW/MID 20S. ALL OTHER FORECAST ELEMENTS LOOK TO BE ON TRACK FOR THE OVERNIGHT HOURS. BEACHLER && .SHORT TERM... 256 PM CST THROUGH THURSDAY... A CLOSED UPPER LEVEL LOW STRETCHES FROM THE NORTHERN PLAINS THROUGH THE NORTHERN GREAT LAKES. IT MOVES OVER SOUTHEAST ONTARIO TOMORROW AFTERNOON AND CONTINUES TO OVER NORTHERN ONTARIO THURSDAY. THE SURFACE LOW IS OVER NORTHERN MICHIGAN AND ITS COLD FRONT IS EAST OF THE CWA OVER CENTRAL INDIANA. THE LOW WILL DEEPEN AS IT MOVES OVER JAMES BAY WEDNESDAY NIGHT AND HIGH PRESSURE BUILDS OVER THE ROCKIES AND PLAINS THROUGH THURSDAY NIGHT. ISOLATED DRIZZLE AND/OR FLURRIES ARE OVER NORTHEAST IL AND THEY WILL PERSIST THROUGH THIS AFTERNOON. NO ACCUMULATION IS EXPECTED. THE GUSTY NW WINDS DIMINISH THROUGH THIS EVENING AND CLOUDS WILL STICK AROUND. OVERNIGHT LOWS WILL BE IN THE LOW TO MID 20S. THE WEATHER THEN GOES ON REPEAT FOR WEDNESDAY AND THURSDAY WITH LAKE EFFECT SNOW ON THE MICHIGAN SIDE OF THE LAKE AND DRY CONDITIONS FOR THE REST OF THE CWA. WENT WITH HIGHER CLOUD COVER THAN GUIDANCE WOULD SUGGEST...BUT WITH 850MB TEMPS FALLING TO -14C THURSDAY... DAYTIME HIGHS WEDNESDAY AND THURSDAY WILL BE IN THE LOW 30S. GUSTY NORTHWEST WINDS WILL MAKE IT FEEL LIKE IT IS IN THE 20S. THICK CLOUD COVER WEDNESDAY AND THURSDAY NIGHT WILL KEEP LOWS IN THE UPPER TEENS TO AROUND 20. MIN WIND CHILLS WILL BE AT OR LESS THAN 10 DEGREES. JEE && .LONG TERM... 256 PM CST THURSDAY NIGHT THROUGH MONDAY... WE STAY IN NORTHWEST FLOW ALOFT THROUGH FRIDAY THEN A WEAK RIDGE MOVES OVERHEAD SATURDAY. A LARGE TROUGH MOVES OVER THE PLAINS SATURDAY NIGHT/SUNDAY AND THEN OVER THE MIDWEST MONDAY. THE LARGE SURFACE HIGH MOVES OVER THE CWA FRIDAY BEFORE REACHING THE EAST COAST SATURDAY NIGHT. A SURFACE TROUGH/COLD FRONT PASSES THROUGH SATURDAY NIGHT AND GUIDANCE CONTINUES TO INCREASE THE PRECIPITATION ASSOCIATED WITH THIS FEATURE. IT IS MUCH TOO EARLY TO MENTION SNOWFALL AMOUNTS...BUT DID RAISE POPS ABOVE SUPERBLEND TO REFLECT GREATER MODEL CONSISTENCY AND CONFIDENCE. SNOW SHIFTS EAST SUNDAY WITH THE FRONT. A SECOND LOW PASSES NORTH OF THE REGION MONDAY AND DRAGS ANOTHER COLD FRONT ACROSS THE REGION MONDAY. MODELS CURRENTLY SHOW DRY CONDITIONS AS THE FRONT PASSES THROUGH WITH LAKE EFFECT SNOW POSSIBLE OVER PORTER COUNTY. TEMPERATURES REMAIN WELL BELOW NORMAL THROUGH THE EXTENDED WITH DAYTIME HIGHS IN THE 30S. THE /WARMEST DAY/ LOOKS LIKE SATURDAY WITH HIGHS IN THE MID TO UPPER 30S. OVERNIGHT LOWS WILL BE IN THE UPPER TEENS AND 20S. JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * MVFR CIGS OVERNIGHT SCATTERING WEDNESDAY MORNING. BMD //DISCUSSION...UPDATED 06Z... THE REGION WILL STAY UNDER A MODERATE NORTHWEST GRADIENT OVER THE NEXT COUPLE DAYS BETWEEN THE DEPARTING LOW THAT IMPACTED THE REGION TUESDAY AND STRONG HIGH PRESSURE BUILDING OVER THE PLAINS. MVFR CIGS ARE IN PLACE AND ARE EXPECTED TO CONTINUE THROUGH EARLY TO MID MORNING WEDNESDAY BEFORE SCATTERING OUT. EXPECT WINDS TO REMAIN GUSTY AT TIMES THROUGH THE PERIOD. BMD //ORD AND MDW CONFIDENCE...UPDATED 06Z... * LOW-MEDIUM CONFIDENCE IN TIMING SCATTERING MVFR CIGS. * HIGH CONFIDENCE IN REMAINING FORECAST ELEMENTS. BMD //OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z... THURSDAY THROUGH SATURDAY...PRIMARILY VFR. CHANCE OF --SN OR -SHSN THURSDAY. SATURDAY NIGHT THROUGH SUNDAY...CHC SNOW. MONDAY...VFR. RATZER && .MARINE... 237 PM CST LOW PRESSURE OVER NORTHERN LOWER MICHIGAN WILL CONTINUE TO DEEPEN AS IT PUSHES TO THE EAST OF JAMES BAY BY WEDNESDAY MORNING...THEN CONTINUES NORTH THROUGH QUEBEC FOR THE REMAINDER OF THE WEEK. STRONG HIGH PRESSURE CURRENTLY OVER THE NORTHERN ROCKIES WILL BUILD ACROSS THE PLAINS DURING THE WEEK...GRADUALLY SPREADING OVER THE LAKE BY THE WEEKEND. THIS WILL RESULT IN A PROLONGED PERIOD OF MODERATE NORTHWEST FLOW THROUGH THE REMAINDER OF THE WEEK. ANOTHER COLD FRONT WILL MOVE OVER THE LAKE SATURDAY NIGHT. KMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 3 AM FRIDAY. SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 6 PM WEDNESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1116 PM CST Tue Nov 11 2014 .UPDATE... ISSUED AT 911 PM CST TUE NOV 11 2014 Clouds over the area and based on satellite trends, believe clouds will remain over the area overnight and into tomorrow morning. Models try to break the clouds up overnight, but models do not have a good handle on the current situation. Current forecast looks ok, so if any changes, they will be minor and no update is planned at this time. && .SHORT TERM...(Tonight) ISSUED AT 215 PM CST TUE NOV 11 2014 Deepening 1001 mb low pressure over northern lower MI as cold front tracks along OH/IN border into nw KY. This was giving blustery wnw winds of 15-25 mph and gusts of 25 to 30 mph across central IL this afternoon. Low pressure lifts ne of the Great Lakes region tonight while strong 1049 mb Canadian high over Alberta ridges into the Great Plains and noses into IL by dawn Wed. Tight pressure gradient over central IL this afternoon weakens tonight and Wed, so expect NW winds to diminish to 8-15 mph this evening and continues into Wed morning. A large canopy of stratocumulus clouds with MVFR ceilings covers IL, IA and central and ne MO. HRRR and RAP models lingers these low clouds over central IL this evening, though low clouds breaking up during this evening in southeast IL, and currently happening in southeast MO. Low clouds will take longer to diminish over ne areas later tonight or during Wed morning. Temperatures currently in the mid to upper 30s with Galesburg and Macomb at 32F. These readings are actually closer to normal lows for mid November. Stayed close to similar MAV/MET cold lows tonight in the lower 20s over central IL with mid 20s in southeast IL. && .LONG TERM...(Wednesday through Tuesday) ISSUED AT 215 PM CST TUE NOV 11 2014 Pattern over North America settling into a highly amplified stable regime, which translates to a rather long duration of below normal temperatures for our area. A Rex block setting up over northwest Canada into parts of Alaska producing a classic cross Polar flow through northern and central Canada, draining right into the good ole U.S. for the remainder of this week and into early next week, at least. We lose the closed upper high at 500 mb but retain more of a omega block across western Canada by late in the weekend and into early next week with a deep upper low just north of Lake Superior with 500 mb temps around -45 degrees C. This deep and cold trof more or less is the anchor trof over the hemisphere influencing the smaller shortwaves and sensible weather over the lower 48. As we head into the end of this forecast period and beyond, the ECMWF suggests some relaxation in the pattern as the flow over western Canada becomes more zonal, which should bottle up the very cold air over northern Canada as we head into late next week. The flow over the lower 48 should become more zonal as well which will lead to a gradual moderating trend as we head into the third week of November. As far as specifics are concerned during this period, we should be rather cold but with very little if any snow through early Saturday as the large Canadian high slowly settles southeast into the Plains by Thu and Friday. Several weak vort maxes are forecast to rotate southeast around the deep and cold trof to our north bringing more clouds from time to time, but no significant precip other than flurries. At this time, not seeing enough evidence to add any mention of flurries as once such shortwave moves thru the area later Thursday into early Friday. Most of the better lift is forecast to remain north of the area. Once the wave shifts to our east, a reinforcing shot of cold air will push across the area with the coldest temps at 850 mb forecast over our area by Friday morning when models indicate -12 to -14 C will reside over the Midwest. As the center of the cold shifts off to our east later Saturday, return flow should setup bringing an increase in clouds ahead of a pair of weather disturbances bringing the threat for light snow to the area Saturday night into Sunday. Models showing some moisture return ahead of the waves for late Sat. into Sunday, but it appears the more significant precip should remain along the Gulf Coast into Sunday where the stronger baroclinic zone will be located ahead of the southern stream wave. The northern stream wave doesn`t look as significant but we should be able to squeeze out a tenth of two of moisture, which may lead to some light accumulating snows for parts of our area Saturday night into Sunday. Once the system shifts off to our east late in the weekend and into early next week, another reinforcing push of Canadian air will filter south into our area keeping temperatures well below normal. The large cold 500 mb trof will then begin to edge slowly off the east just after this forecast period with ensembles suggesting another rather vigorous southern stream shortwave interacting with the low level baroclinic zone over the Gulf Coast region sending a large area of precip northeast, mainly along and south of the Ohio River Valley late next week with most of the ensemble members suggesting no phasing occurring with the northern stream trof. So the cold will hang on for a while, but other than the light snowfall expected later Saturday into Sunday, no major weather systems are expected to affect the region. Daytime highs will be mostly in the 30s, where average highs this time of year are in the mid to upper 50s. Look for early morning lows in the upper teens north to the lower or middle 20s far southeast, with normal morning lows in the mid to upper 30s. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) ISSUED AT 1116 PM CST TUE NOV 11 2014 MVFR clouds remain over the TAF sites this evening and should remain there through the night and into tomorrow. Some short term models have the sky becoming scattered in the west tomorrow afternoon, but not confident with this, so will be keeping TAFs simple and having MVFR cigs around 2-2.5kft through the TAF period at all sites. Winds will be out of the northwest around 10-13kts through the period as well. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Auten SHORT TERM...07 LONG TERM...Smith AVIATION...Auten
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
932 PM EST Thu Nov 13 2014 ...Forecast Update... Issued at 930 PM EST Thu Nov 13 2014 Have some snow flurries at times passing through the region. RUC soundings indicate a narrow saturated layer around 5 kft at around -14C. This layer is generating the flurries that are falling into a fairly dry layer underneath. That same RUC sounding indicates the layer could stick around a little longer than in the previous forecast so have extended the timing for flurries to at least 09Z. Otherwise, the rest of the forecast is on track for lows in the lower 20s tonight. .SHORT TERM (Now through Friday Night)... Issued at 300 PM EST Thu Nov 13 2014 We`ll continue to see flurry activity across the region late this afternoon and evening as a cold Arctic airmass continues to settle into the Midwest squeezing all available moisture out of the atmosphere. Low clouds look to stick around through at least midnight and then begin to thin from west to east during the pre-dawn hours. This being the case, we could see a late night drop off in temps as those clouds become scattered in nature. This should result in low temps in the lower 20s tonight with a few upper teens possible in sheltered areas. Expect partly cloudy skies Friday as sfc high pressure settles into the region becoming centered over the Ohio Valley Fri night. This will result in high temps Friday in the mid 30s with low temps Friday night bottoming out in the upper teens and lower 20s. Ideal rad cooling conditions will exist for Friday night, so wouldn`t be surprised to see some mid teens for lows. .LONG TERM (Saturday through Thursday)... Issued at 330 AM EST Thu Nov 13 2014 ...Some Snow Accumulations Possible Sunday into Monday... The main forecast challenge will be snow chances this weekend into Monday. The First Snow Chance... Our first chance at a light snow will come Sat night into Sun morning as a shortwave upper level trough pushes through the upper Midwest and a weak frontal boundary attempts to organize near the TN Valley. These two features never really look to become well phased so it looks like we`ll remain in between systems to our north and south Sat night into Sun morning. A weak plume of moisture over our region looks to result in some light rain or rain/snow mix changing over to all light snow sat night with maximum accumulations around a half inch. Temps will warm into the upper 30s to around 40 Sun afternoon causing any remaining precip to change over to light rain and causing any light snow accums to melt. The Second Snow Chance... A better chance for snow over the region will arrive for Sun night into Monday as a shortwave upper trough ejects out of the SW CONUS. This wave will strengthen the weak sfc boundary located to our south and pull up plentiful Gulf moisture into the Ohio Valley. As typical with these overrunning precip events, a number of model solns exists, each with differing depictions of storm track, warm nose strength, and depth of the shallow cold air mass close to the sfc. The 12Z runs from today still mostly put portions of central KY under a threat for accumulating snows Sun night into Mon morning. The ECMWF soln is farthest NW and would result in a threat for accumulating snow over southern Indiana as well. The 12Z op GFS would indicate a farther SE track shifting the main snow threat to south central and east central KY. Also new with this model run are more robust QPF fields from the GEM and ECMWF. This being said, feel that a solid 1-3 inches of snowfall will be possible across a portion of the Ohio Valley Sun night into Mon morning. Potentially higher amounts of snowfall would be possible if the more robust QPF fields pan out. For our latest thinking on best area for accumulating snow and some preliminary snowfall amounts, see weather.gov/lmk. The Monday morning commute has the potential to be negatively impacted by this snowfall. The Rest of the Week... The rest of the week looks unseasonably cold with highs limited to the 30s through Wed...potentially colder if snow accums can be achieved Sun night/Mon morning. Low temps will be quite chilly in the teens for mid week. && .AVIATION (00Z TAF Update)... Updated at 620 PM EST Thu Nov 13 2014 Cloud field enhanced by daytime heating, if you can call it that, should wane some with the overnight. Only exception may be a brief drop to near MVFR conditions at LEX around midnight as a trough axis swings through. Still have some very light snows showing up on radar and these may hit the northern terminals the next few hours. Given how light it should be elected not to include in this set of TAFs. Otherwise expect VFR through the period with generally northwest winds. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ Update.........RJS Short Term.....AMS Long Term......EER/AMS Aviation.......RJS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
121 PM CST Wed Nov 12 2014 .SHORT TERM...(Tonight through Friday night) Issued at 121 PM CST WED NOV 12 2014 Clouds continued to cover the CWFA early this afternoon, keeping temperatures from rising much as well. Breaks continue to head SE from Missouri and west IL. Should see a gradual decrease with time. RAP was a decent guide in handling the general trend. At the surface, strong high pressure with unseasonably cold air will continue to move southeast, overspreading the area. It should finally be centered over our area by 12z Saturday. Meanwhile, a double barrel low over the northern Plains and Great Lakes will phase, with one low heading up through Quebec, while energy from the western end swings across the Upper Midwest and Great Lakes tonight through Thursday. Expect mainly mid and upper level clouds tonight through early Thursday, followed by decreasing clouds. NW flow will persist as energy dives south into the Rockies from west Canada Friday through Friday night. Dry weather is forecast with just a few clouds from Thursday afternoon through Friday night. As far as temperatures, followed a blend of the slightly colder MOS and standard model output. MOS appears to have finally caught on to the degree of cold air. Prior output from a few days ago, MOS had its typical mild climo influence bias, while the standard raw model output was better identifying how cold it would likely be. No real model preference in the short term tonight and beyond. A GFS/NAM blend was used. .LONG TERM...(Saturday through Wednesday) Issued at 121 PM CST WED NOV 12 2014 Main focus continues to be on weekend precip (even wintry) chances, and the continued cold. Both the GFS and ECMWF ops runs continue to suffer run to run inconsistencies, especially with respect to timing in response to the evolution of the mid tropospheric flow pattern over the CONUS east of the Rockies. The GFS is trending toward, and ECMWF back towards separate energy that may pinch off the main trof over the Southern Rockies, eventually heading east over the weekend. The models continue to advertise a lead weak s/wv that will move from the southern Rockies to Mississippi Valley region Saturday into Saturday night. May see rather light wintry mix into SEMO by afternoon. Will continue with light rain/light snow mention here. Saturday night, as the wave moves ENE, the models continue to hint at a band of light precip (parameters suggest light snow), for parts of the area. Not much QPF, so still not expecting much. But any minor coating of light snow around here...well. The models are not showing much now for Sunday, thus will keep PoPs on the low side. As some slightly warmer boundary layer air advects into the SE 1/2 of the CWFA (still favor the slightly colder GFS), will use a mix (including light rain) mention, with just light snow NW 1/2. As the aforementioned mid level wave moves east Sunday and phases with the parent broad mid level trof by Sunday night, models ramp up moisture a bit over the SE 1/2 of the area. This is slower, so PoPs will need to linger Sunday night, vs. early depictions of ending things by Sunday evening. This is where the back and forth (changing forecast) has been most prominent. Again types, light wintry mix possible SE 1/2, just a small chance of light snow NW 1/2. The GFS remains quicker departing chances, while the ECMWF lingers the chance now through early Monday. Given the adjustments and changes that continue to go on within the models, will keep PoPs in check and only in the chance category for now. Otherwise continued cold through early next week. Dry weather returns for most of Monday on through Wednesday. && .AVIATION... Issued at 121 PM CST WED NOV 12 2014 Breaks in the clouds generally west of a line from KSAR to KPOF. Looks like the breaks and decrease in clouds will continue SSE through the rest of the day. So gradual improvement in the MVFR cigs expected. Overnight through early Thursday, a respectable amount of mid and upper level moisture/clouds likely. NNW winds will continue in the 5-12 kt range. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ CN
AREA FORECAST DISCUSSION
NWS PADUCAH KY
854 AM CST Wed Nov 12 2014 .UPDATE... Issued at 854 AM CST WED NOV 12 2014 Aviation update. && .SHORT TERM...(Today through Friday night) Issued at 302 AM CST WED NOV 12 2014 Latest satellite shows cloud cover holding on more than models previously alluded to, so slowed down clearing until at least late morning/midday. Cold air will continue to filter into the region, with highs today only in the upper 30s to lower 40s. High pressure over the northern Rockies will gradually slide southeast through the rest of the work week, with models showing the high centered over the PAH forecast area by 00z Saturday. This will help us see a lot more sunshine, but also continue the downward trend in our temperatures. Highs Thursday and Friday will only reach the lower to middle 30s, with lows in the upper teens to lower 20s. These temperatures will be 20 to 25 degrees below normal. .LONG TERM...(Saturday through Tuesday) Issued at 302 AM CST WED NOV 12 2014 Confidence in the long term still not that great due to model discrepancies. At the beginning of the period as high pressure shifts east of the region, overrunning precip due to isentropic upglide is expected to develop over the far western/northwestern sections of our CWA Saturday afternoon. Per thermal profiles, decided to go with a rain/snow mix. For the most part, model soundings and thermal profiles still indicate an all snow event Saturday night, but with the latest ECMWF run showing slight warming in the column and model QPF output not in good agreement, very difficult to determine accurate snowfall amounts at this time. Would not be surprised if most accumulating snow falls Saturday evening with possibly only light snow showers/flurries after midnight. With this time frame being so far out and with continued model disparity, decided to just go with 12 hour weather grids versus getting too fancy with timing. All areas should receive some snow accumulation Saturday night with the southern half of our CWA expected to get the most (an inch or so). After a possible brief respite late Saturday night/early Sunday morning, a cold front blasting across the region on Sunday is expected to generate a round of precipitation. Per thermal profiles precipitation Sunday morning should be all snow, but in the afternoon all snow over the northwest half of the region with a rain/snow mix over the southeast half. Again would not be surprised if most measurable precipitation is over by midday Sunday or shortly thereafter, but for now will continue to keep grids as simple as possible. Minimal additional snow accumulation expected on Sunday. On the back side of this system, light snow may linger over the far southeast corner of our CWA Sunday evening. Beyond that, high pressure at the surface and flow aloft becoming more northwest should produce dry conditions through the remainder of the long term period along with below normal temperatures. && .AVIATION... Issued at 854 AM CST WED NOV 12 2014 Looking at the RAP and satellite trends, the low clouds will likely go nowhere through the day. There may be thin spots. But given the cold advection, weaker flow and H9 moisture progs off the RAP, seems unlikely we will rid the clouds today. Will improve conditions from 00z on. NNW winds will continue, but mainly below 10 kts tonight. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1133 PM CST Tue Nov 11 2014 .UPDATE... Issued at 1133 PM CST TUE NOV 11 2014 The AVIATION section has been updated for the 06Z TAF issuance. && .SHORT TERM...(Tonight through Thursday night) Issued at 153 PM CST TUE NOV 11 2014 Strong cold front moved through the area today, bringing some light rain/drizzle to the region. A particularly cold air mass is spilling into the region behind the front. Any lingering areas of rain should be exiting the area by 00Z Wednesday so will leave tonight`s forecast dry. This dry weather will continue through the end of the week. Canadian high pressure will continue to build into the region tonight with cold air advection in full force. A strong upper level closed low over eastern Montana and western North Dakota this morning will move east toward the upper Great Lakes by Wednesday morning and then eventually make its way into eastern Canada. As this happens, a trough dive south into the eastern third of the nation, which will allow for the cold air to infiltrate the region. Therefore, the main challenges in the short term will be cloud cover (at least for tonight into tomorrow) and temperatures. Will be watching the clearing line closely to see if it indeed will keep tracking eastward across the CWA this evening. Model time heights and soundings indicate some lingering low level moisture, so this will have to be watched. The RUC tries to clear out the southwestern parts of our CWA early this evening, but later in the evening, it could cloud back up. After some coordination with neighboring offices, will probably have to go a bit more pessimistic with cloud cover at least this evening. It appears as though the clouds should break up by tomorrow morning. Strong cold air advection will continue on Wednesday and Wednesday night. So, despite some sunshine, highs will only be in the upper 30s to lower 40s with a 10 to 15 mph wind, as H85 temps plummet below zero by 00Z Thursday. Highs will be even lower on Thursday and only be in the 30s. This will be a very dry airmass as well, with dewpoints going down into the teens by Thursday. By Thursday night, the center of the sfc high should be positioned just to our west which should set the stage for one of our coldest nights this week. .LONG TERM...(Friday through Tuesday) Issued at 153 PM CST TUE NOV 11 2014 Focus will be on persistent colder than normal temperatures, and the chance of light wintry precipitation Saturday night into Sunday. Having watched the models since Saturday, the GFS has been the more consistent model in general terms with the pattern evolution, more in line with previous ensemble mean solutions. Meanwhile the ECMWF, especially after evaluating the 12z version continues to exhibit more run to run inconsistency. Therefore more weight will be given to the GFS. First, looking at the weekend precipitation. Believe the colder GFS solution is the way to go given the degree of cold air within this pattern. Both models show a subtle H7/H5 wave moving ENE across the area Saturday night. Could be some very light precip into SEMO by Saturday afternoon. Saturday night, a swath of light precip / QPF expected somewhere across the CWFA. Again, ECMWF 00z run showed hardly anything, then the 12z run ramps up QPF (a bit too extreme with the changes). Precip type Saturday night should be mainly light snow. May be borderline toward the TN border, largely dependent on the strength of the H8 flow from the SSW, which isn`t that impressive per the GFS. A second swath of moisture and light QPF/precip expected Sunday with the parent H5 wave forecast to move across the Mississippi Valley region toward the Ohio Valley region. Best chances Sunday will be from SW Indiana into west KY, only slight chances west into SEMO, southern IL. Colder solutions again depict mainly light snow. Though, should some boundary layer warming occur briefly Sunday, may be a mix with rain into west KY. We generally don`t talk specifics this far out, with respect to wintry precip (in particular amounts). Still too soon to say, given temps Sunday back up into the mid 30s, some upper 30s (above freezing). And Saturday night, QPF, for the most part, has been forecast to be "light", more often than not. PoPs will be kept in the chance category, but upped slightly. Otherwise, dry weather Friday through most of Saturday. In the wake of the system on Sunday, dry/cold weather for Sunday night through Tuesday, with an active flow pattern continuing with the mean broad trof over the east 2/3 of the CONUS. && .AVIATION... Issued at 1133 PM CST TUE NOV 11 2014 A solid area of MVFR ceilings has overspread the entire area this evening, and looking upstream, it appears that they will be here through the night and well beyond daybreak Wednesday. There is a very small area of clearing near KSPI/KTAZ in central Illinois that is moving southward toward our region. Also ceilings ahead of the clear spot have lifted to just beyond 3kft. Would not be surprised to see a brief period of scattered clouds at KEVV and KOWB overnight, or just a low VFR ceiling. The latest guidance holds onto the low clouds in the east to near 18Z. North winds will continue through the period, however, gusts should be few and far between. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ UPDATE...DRS SHORT TERM...CW LONG TERM...CN AVIATION...DRS
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
354 PM CST WED NOV 12 2014 .SHORT TERM... THE ONSET OF UNSEASONABLY COLD CONDITIONS HAS BEGUN ACROSS THE FORECAST AREA WITH THE COLD FRONT CONTINUING TO MOVING SOUTHWARD ACROSS THE NEARSHORE COASTAL WATERS AND AN ARCTIC AIRMASS MOVING IN. TEMPERATURES AT MOST LOCATIONS IN THE CWA ARE EITHER HOLDING STEADY OR FALLING. CLOUDY SKIES AND ELEVATED WINDS WILL LIMIT COOLING OVERNIGHT BUT SHOULD SEE LOWS IN THE UPPER 30S TO MID 40S FOR MOST CITIES. HAVE DECIDED TO BUMP UP POPS FOR MUCH OF THE CWA FOR THE OVERNIGHT PERIOD MAINLY FROM 06-12Z. MEDIUM RANGE MODELS HAVE BEEN RELENTLESS WITH CONSISTENTLY SHOWING INCREASING SHOWERS ALONG A SOUTHEAST LA/COASTAL MISSISSIPPI BELT DURING THAT TIME FRAME. SOME OVERRIDING MOISTURE LOOKS TO BE COMING UP FROM THE SOUTHWEST ALONG THE COAST AS A WEAK UPPER LEVEL VORT MAX PASSES OVER. MESO MODELS HAVE PICKED UP ON THIS AS WELL. THE HRRR DOES LOOK TO BE A LITTLE OVERDONE BUT THE GENERAL COVERAGE IS PROBABLY PRETTY GOOD. THE EXTENT NORTH IS STILL IN QUESTION. HAVE KEPT IT OUT OF SW MISSISSIPPI FOR THE MOST PART BUT COULD HAVE TO DO A LAST MINUTE ADJUSTMENT TO NUDGE POPS BACK NORTH TO INCLUDE THAT AREA. RAIN CHANCES WILL LINGER INTO THE MORNING HOURS THURSDAY BUT SHOULD FADE QUICKLY AS AFTERNOON ROLLS AROUND. PERSISTENT CAA AND CLOUDCOVER SHOULD KEEP MUCH WARMING FROM OCCURRING .LONG TERM... STRONG AND COLD HIGH PRESSURE WILL BUILD INTO THE AREA FRIDAY... BRINGING WHAT SHOULD BE THE COLD TEMPERATURES THE AREA HAS SEEN SINCE LAST WINTER/SPRING. HAVEN/T CHANGED LOWS FRIDAY OR SATURDAY MORNING BY MUCH. MAYBE A DEGREE AT THE MOST IN A FEW LOCATIONS. THOSE TEMPERATURES OF MID 20S TO MID 30S ARE EITHER WITHIN A FEW DEGREES OR RIGHT AT THE RECORD LOWS DEPENDING ON LOCATION...SO A FEW RECORDS COULD BE BROKEN. SINCE THIS WILL BE THE FIRST WIDESPREAD FREEZE OF THIS FALL SEASON...A FREEZE WATCH REMAINS IN EFFECT AND WILL LIKELY BE UPGRADED TO A WARNING EITHER ON THE MIDNIGHT SHIFT OVERNIGHT OR THIS FCST PACKAGE TOMORROW. TEMPERATURES WILL JUMP UP ABOUT 10 DEGREES SATURDAY AS WINDS SHIFT BACK AROUND TO THE EAST/SOUTHEAST...MOISTURE COMES BACK UP AND THE AIR MASS BEGINS TO MODIFY. MODELS STILL SHOWING AN UPPER LEVEL IMPULSE TRACKING ACROSS THE SOUTHERN STREAM OF THE WESTERLIES COMBINING WITH ANOTHER UPPER TROUGH DROPPING OUT OF CANADA TO BE MOVING THROUGH SUNDAY INTO MONDAY...WHICH IS A SLOWER SOLUTION THAN PREVIOUS MODEL RUNS. B/C OF THIS CHANGE...HAVE SHIFTED THE START AND ENDING OF PRECIP BACK ABOUT 12 HOUR AND ADJUSTED TEMPERATURES ACCORDINGLY AS WELL. THE SOUTHERN FEATURE WILL DRAW UP A SURFACE LOW DEVELOPING IN THE NORTHWESTERN GULF OF MEXICO AND CARRY IT ALONG THE NORTHERN GULF COAST. THIS LOW WILL ENHANCE SHOWER DEVELOPMENT AS A COLD FRONT MOVES THROUGH AS WELL. MODEL SOUNDINGS INDICATE QUITE A SATURATED COLUMN WITH 1.8 INCHES FOR PRECIP WATER. THIS IS IN THE 90TH PERCENTILE WITH 2.0 INCHES THE HIGHEST EVER OBSERVED THIS TIME OF YEAR. SO DEFINITELY EXPECTING HIGHER RAIN EFFICIENCY WITH QUITE A BIT OF QPF. 1 TO 2 INCHES EVENT TOTAL POSSIBLE. COOLER AND DRIER AIR WILL RETURN POST FRONTAL MONDAY AFTERNOON WITH THE REST OF THE WEEK LIKELY TO BE BELOW NORMAL AS UPPER LEVEL TROUGH HOLDS STRONG OVER THE EASTERN HALF OF THE COUNTRY. MEFFER && .AVIATION... A MIX OF IFR AND MVFR CEILINGS GENERALLY RANGING AROUND 1000 TO 1500 FEET WILL CONTINUE TO IMPACT THE TERMINALS THROUGH 00Z. AFTER 00Z...SOME IMPROVEMENT IS EXPECTED AT KBTR AND KMCB AS DRIER AIR ADVECTS IN. THIS WILL RAISE CEILINGS ABOVE 3000 FEET AND BRING VFR CONDITIONS BACK TO THESE LOCATIONS. ELSEWHERE...THE MIX OF IFR AND MVFR CEILINGS WILL PERSIST THROUGH THE OVERNIGHT HOURS. CONDITIONS WILL FINALLY BEGIN TO IMPROVE TOWARD VFR CONDITIONS AFTER 12Z AS A DRIER AIRMASS OVERSPREADS THE REGION. 32 && .MARINE... AS A COLD AND DRY AIRMASS ADVECTS INTO THE AREA TONIGHT AND TOMORROW...STRONG GRADIENT FLOW ALOFT WILL EASILY MIX DOWN TO THE SURFACE. AS A RESULT...A PERIOD OF SMALL CRAFT ADVISORY CONDITIONS IS EXPECTED OVER ALL OF THE WATERS BEGINNING TONIGHT AND PERSISTING THROUGH FRIDAY MORNING. CONDITIONS WILL EASE BACK INTO EXERCISE CAUTION RANGE FOR THE REMAINDER OF FRIDAY AND SATURDAY AS THE GRADIENT FLOW ALOFT WEAKENS. HOWEVER...ANOTHER STRONG FRONTAL SYSTEM WILL SWEEP THROUGH THE AREA SUNDAY NIGHT. A COMBINATION OF STRONG GRADIENT FLOW ALOFT AND MUCH COLDER AIR MOVING OVER THE WATERS WILL BRING ANOTHER ROUND OF SMALL CRAFT ADVISORY CONDITIONS TO ALL OF THE MARINE ZONES MONDAY AND TUESDAY. 32 && .DECISION SUPPORT... DSS CODE...BLUE. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...SLURRY SUPPORT. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE. && .PRELIMINARY POINT TEMPS/POPS... MCB 37 49 26 48 / 10 10 0 0 BTR 38 49 28 50 / 30 20 0 0 ASD 44 53 30 52 / 40 40 0 0 MSY 45 52 36 51 / 40 40 0 0 GPT 45 54 33 52 / 40 40 0 0 PQL 45 54 29 52 / 40 50 0 0 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...FREEZE WATCH FROM 11 PM THURSDAY TO 9 AM FRIDAY FOR THE FOLLOWING ZONES: ASCENSION...ASSUMPTION...EAST BATON ROUGE...EAST FELICIANA...IBERVILLE...LIVINGSTON...NORTHERN TANGIPAHOA...POINTE COUPEE...SOUTHERN TANGIPAHOA...ST. HELENA...ST. JAMES...ST. TAMMANY...WASHINGTON...WEST BATON ROUGE...AND WEST FELICIANA. GM...SMALL CRAFT ADVISORY FROM MIDNIGHT THURSDAY TO 9 AM FRIDAY FOR THE FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE BORGNE...LAKE PONTCHARTRAIN AND LAKE MAUREPAS...AND MISSISSIPPI SOUND. MS...FREEZE WATCH FROM 11 PM THURSDAY TO 9 AM FRIDAY FOR THE FOLLOWING ZONES: AMITE...HANCOCK...HARRISON...JACKSON...PEARL RIVER...PIKE...WALTHALL...AND WILKINSON. GM...SMALL CRAFT ADVISORY FROM MIDNIGHT THURSDAY TO 9 AM FRIDAY FOR THE FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE BORGNE...LAKE PONTCHARTRAIN AND LAKE MAUREPAS...AND MISSISSIPPI SOUND. && $$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
203 AM EST WED NOV 12 2014 .SYNOPSIS... A COLD FRONT WILL MOVE ACROSS THE REGION LATE TONIGHT AND WEDNESDAY MORNING. A WEAK UPPER LEVEL DISTURBANCE WILL CROSS THE AREA THURSDAY NIGHT...THEN CANADIAN HIGH PRESSURE WILL BUILD IN THROUGH SATURDAY. LOW PRESSURE MAY AFFECT THE AREA ON SUNDAY. && .NEAR TERM /THROUGH TODAY/... DENSE FOG ADVISORY FOR WESTERN BALT-WASH SUBURBS UNTIL 8AM. CALM AIR AND CLEAR WEST OF A MARINE STRATUS LAYER HAS ALLOWED DENSE FOG GENERALLY OVER THE CNTRL/NRN VA PIEDMONT AND PROBABLY ALONG THE POTOMAC WEST TO BERKELEY COUNTY WV. PRESSURE GRADIENT WILL INCREASE TOWARD DAYBREAK...MAY CANCEL ADVISORY FROM THE WEST TOWARD SUNRISE. WILL ALSO NEED TO MONITOR MARINE STRATUS FOR AREAS WHERE THE CEILING LOWER TO FOG THAT WOULD ALSO BE DENSE...MAY HAVE TO EXPAND ADVISORY EAST TO ACCOUNT FOR THAT. 05Z HRRR DOES DEPICT 0.5MI VSBY ACROSS THE ERN HALF OF THE CWA INTO THE MID MORNING HOURS. PREVIOUS... (FORECAST AREA REMAINS UNDER A THIN AREA OF HIGH PRESSURE THIS EVENING...SANDWICHED BETWEEN A DEVELOPING COASTAL LOW EAST OF THE CAROLINAS AND A SHARP COLD FRONT OVER EASTERN OHIO. WELL- DEFINED STRATUS DECK NEAR THE I-05 CORRIDOR...WITH MOSTLY CLOUDY SKIES OVER BALTIMORE AND WASHINGTON DC BUT VERY FEW CLOUDS OVER DULLES AIRPORT...THE VIRGINIA PIEDMONT AND AREAS TO THE WEST. HIGH PRESSURE WILL MOVE OFF THE MIDDLE ATLANTIC COAST TONIGHT AND THE COLD FRONT WILL APPROACH FROM THE WEST. SOUTH-SOUTHEAST FLOW WILL HELP PULL MARINE MOISTURE FURTHER WEST OVERNIGHT WITH AREAS OF FOG AND LOW CLOUDS...ESPECIALLY EAST OF THE BLUE RIDGE AND ACROSS I-95 AND THE METRO AREAS. WILL CONTINUE TO MONITOR FOR THE POTENTIAL OF LOCALLY DENSE FOG. WINDS WILL GRADUALLY SHIFT TO THE SOUTH AND SOUTHWEST AS THE COLD FRONT APPROACHES...AND THIS WILL LESSEN THE MARINE INFLUENCE OVER THE AREA. FOR THIS REASON...NOT VERY CONFIDENCE YET IN POTENTIAL FOR DENSE FOG. OVERNIGHT LOWS WILL ONLY FALL BACK TO THE 40S AND 50S. LOW PRESSURE OFF THE CAROLINA COAST WILL MOVE NORTHEAST AND AWAY FROM THE MIDDLE ATLANTIC REGION OVERNIGHT. OTHER THAN ENHANCEMENT IN LOW LEVEL MOISTURE OVER THE EAST WITH FOG AND PERHAPS SOME DRIZZLE...THE LOW WILL TRACK FAR ENOUGH EAST TO KEEP MEANINGFUL QPF OUT OF THE CWFA. COLD FRONT WILL CROSS THE REGION FROM WEST TO EAST ON WEDNESDAY MORNING. WINDS WILL SHIFT INTO THE NORTHWEST AND BECOME GUSTY DURING THE AFTERNOON INTO THE EARLY EVENING. ANY REMAINING MARINE LAYER WILL SCOUR OUT. A FEW SHOWERS WILL BE POSSIBLE EARLY TO MID MORNING OVER THE UPSLOPE FAVORED LOCALES IN THE POTOMAC HIGHLANDS. TEMPERATURES ARE EXPECTED TO WARM INTO THE 50S TO NEAR 60 EAST OF THE BLUE RIDGE...PRIOR TO THE COLD AIR INFILTRATION. && .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... GRADIENT RELAXES A LITTLE WEDNESDAY NIGHT AS LOW PRESSURE MOVES FURTHER OUT TO SEA AND HIGH PRESSURE BUILDS OVER THE PLAINS. COLDER AIR MOVES IN ON NORTHWEST WINDS...WITH MINIMA IN THE 30S ACROSS MUCH OF THE CWA...MAYBE EVEN 20S WITHIN SOME OF THE COLDER SPOTS. MODELS SHOW CLOUDS INCREASING DURING THE DAYTIME THURSDAY. MAXIMA WILL BE BELOW NORMAL...BUT ANY PRECIPITATION THAT MAY START TO BREAK OUT IN THE AFTERNOON IN ASSOCIATION WITH A MID-LEVEL DISTURBANCE WOULD LIKELY BE RAIN EXCEPT ACROSS THE POTOMAC HIGHLANDS. MODELS ARE TRENDING WITH MUCH OF THE MOISTURE FROM THE DISTURBANCE BEING SOUTH AND THEN OFFSHORE THURSDAY NIGHT. STILL HAVE LOW POPS MAINLY I-95 AND EAST. P-TYPE MAINLY RAIN BUT CAN/T RULE A FEW WET SNOW FLAKES TOWARD THE END OF THE NIGHT IF IT WERE TO STILL PRECIPITATE. && .LONG TERM /FRIDAY THROUGH TUESDAY/... WITH COLDER AIR MOVING INTO THE REGION ON A WEST-NORTHWEST TO NORTHWEST WIND FRIDAY...THERE COULD BE A FEW UPSLOPE SNOW SHOWERS IN THE HIGHEST ELEVATIONS OF THE POTOMAC HIGHLANDS. HIGH PRESSURE WILL BUILD INTO THE REGION FRIDAY NIGHT THROUGH SATURDAY NIGHT. THIS HIGH SHIFTS TO THE COASTAL WATERS SUNDAY TO ALLOW FOR A STRONG COLD FRONT TO MOVE TO THE COAST BY LATE IN THE DAY SUNDAY AND THEN OFFSHORE BY SUNDAY NIGHT. A MODIFYING SOUTHERLY WIND THROUGHOUT THE DAY SUNDAY MAY SUPPORT MAINLY RAIN SHOWERS NEAR AND EAST OF THE BLUE RIDGE MOUNTAINS...WHILE A MIX OF RAIN AND SNOW SHOWERS COULD OCCUR TO THE WEST OF THE BLUE RIDGE. AS UPPER LEVEL ENERGY DRIVES EAST SUNDAY NIGHT AND THE AIR TEMPERATURE GETS COLDER WITH THE SETTING SUN...THERE IS A CHANCE THAT RAIN AND SNOW SHOWERS BECOME A BRIEF PERIOD OF SNOW SHOWERS FARTHER EAST. THERE IS A LOT OF UNCERTAINTY IN TERMS OF COVERAGE OF ANY SNOW SHOWERS IN THE EAST. THIS WOULD LIKELY DEPEND ON THE DEPTH OF COLDER AIR IN THE LOWER THREE TO FOUR THOUSAND FEET OF THE ATMOSPHERE. A FEW RAIN OR SNOW SHOWERS MAY LINGER IN THE POTOMAC HIGHLANDS OR PERHAPS NEAR THE CHESAPEAKE BAY MONDAY. FOR NOW...THINKING A SLIGHT CHANCE SINCE MOST OF ANY LINGERING ENERGY WITH ASSOCIATED UPPER LEVEL TROUGH WILL BE EAST OF THE REGION AND NVA DEVELOPS FROM WEST TO EAST. FOR THE MOST PART...HIGH PRESSURE WILL DOMINATE MONDAY NIGHT INTO TUESDAY. WE WANTED TO MENTION A SLIGHT CHANCE OF SNOW SHOWERS WITH THE NEXT UPPER TROUGH ON TUESDAY. CONFIDENCE IS VERY LOW. && .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/... VLIFR CONDITIONS IN FOG NEAR THE WESTERN EDGE OF A PERSISTENT MARINE STRATUS DECK (CARROLL COUNTY MD DOWN TO CENTRAL VA...INCLUDING KIAD. STRATUS LAYER MAY LOWER TO WIDESPREAD IFR CIGS AND POSSIBLY TO THE GROUND AS FOG. A COLD FRONT WILL MOVE THROUGH THE TERMINALS WEDNESDAY MORNING. NO PRECIPITATION EXPECTED. CIGS WILL RETURN TO VFR. NW WINDS AROUND 10KT WITH POTENTIAL FOR GUSTS TO 15-20KT. WINDS DIMINISH EARLY WEDNESDAY EVENING ACROSS THE TERMINALS. DISTURBANCE WILL BRING A CHANCE FOR MAINLY RAIN LATE THURSDAY INTO THURSDAY NIGHT...PERHAPS MIXING WITH SNOW SHOWERS LATE AT NIGHT. VFR CONDITIONS FRIDAY THROUGH SATURDAY. WINDS WILL BE NORTHWEST AND GUSTING TO 20 TO 25 KNOTS. && .MARINE... LIGHT ESE-SE WIND WILL PERSIST OVERNIGHT INTO WEDNESDAY BEFORE SHIFTING INTO THE NW WEDNESDAY MID MORNING AND CONTINUING INTO WEDNESDAY NIGHT. SMALL CRAFT CONDITIONS CAN BE EXPECTED DURING THIS TIME FRAME WITH GUSTS AT OR ABOVE 25 KT. SCA CONTINUES INTO WEDNESDAY EVENING ALL WATERS. GRADIENT STARTS TO RELAX A LITTLE BUT WITH NW FLOW CONTINUE HEADLINE DOWN THE BAY FOR THE ENTIRE NIGHT. POTENTIAL FOR SCA ALSO EXISTS FOR THURSDAY NIGHT. SMALL CRAFT ADVISORIES MAY BE NEEDED FRIDAY INTO FRIDAY EVENING WITH HIGH PRESSURE BUILDING IN FROM THE WEST. WINDS COULD GUST 20 TO 25 KNOTS. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...DENSE FOG ADVISORY UNTIL 8 AM EST THIS MORNING FOR MDZ003>005- 009-010. VA...DENSE FOG ADVISORY UNTIL 8 AM EST THIS MORNING FOR VAZ042- 050>053-055-056-501-502. WV...DENSE FOG ADVISORY UNTIL 8 AM EST THIS MORNING FOR WVZ052-053. MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 6 AM EST THURSDAY FOR ANZ531>534-537>543. SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 10 PM EST THIS EVENING FOR ANZ530-535-536. && $$ SYNOPSIS...BAJ/BPP/KRW NEAR TERM...BAJ/KS/KRW SHORT TERM...BPP LONG TERM...KLW AVIATION...BAJ/BPP/KS/KRW MARINE...BPP/KS/KRW
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
520 AM EST WED NOV 12 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 452 PM EST TUE NOV 11 2014 THE 21Z WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW STRONG SHORTWAVE OF INTEREST LIFTING E-NE THROUGH THE UPPER GREAT LAKES. STRONG DRYING AND SUBSIDENCE ON THE BACKSIDE OF THIS SHORTWAVE HAS ALLOWED THE SYSTEM SNOW TO DIMINISH OVER THE SRN TIER COUNTIES OF UPPER MI THIS AFTERNOON. LAKE EFFECT SNOW IS STILL GOING STRONG HOWEVER ALONG THE LAKE SUPERIOR COUNTIES AIDED BY A UPSLOPE NNE FLOW...THIS IS ESPECIALLY EVIDENT OVER HIGHER TERRAIN OF MQT-BARAGA COUNTIES WHERE THE RADAR SHOWS REFLECTIVITY AT OR ABV 30 DBZ. TONIGHT AND WEDNESDAY...MAIN CONCERN WAS ONGOING WSW HEADLINES. SINCE SNOW HAS ALREADY DIMINISHED ACROSS MUCH OF THE SRN TIER COUNTIES HAVE CANCELLED THE WINTER STORM WARNINGS FOR IRON THROUGH SRN SCHOOLCRAFT COUNTIES. DECIDED TO TRANSITION FM WINTER STORM WARNINGS TO LAKE EFFECT SNOW ADVISORIES OVER NRN SCHOOLCRAFT AND LUCE COUNTIES AS THE HEAVIER SYSTEM SNOW HAS EXITED EAST AND NE FLOW WILL LIMIT LES ACCUMULATION UNTIL LATER TONIGHT INTO WEDNESDAY WHEN WINDS BACK FM NNE TO MORE NW. EXPECT LES ACCUMULATION OF 2-4 INCHES TONIGHT WITH ANOTHER 1-3 INCHES ON WEDNESDAY AS 850 MB TEMPS FALL TO -13C LEADING TO LAKE DELTA-T NEAR 18C. HAVE DECIDED TO KEEP THE WINTER STORM WARNINGS GOING ELSEWHERE ACROSS THE REST OF THE WEST AND NORTH CENTRAL FCST AREA AS NNE FLOW WILL GRADUALLY BACK TO THE NW LATE TONIGHT. STRONGLY CYCLONIC UPSLOPE NNE FLOW AND DEEP MOISTURE PROFILE THROUGH 12-15 KFT WILL FAVOR MQT-BARAGA COUNTIES...PORTIONS OF THE KEWEENAW AND THE HIGHER TERRAIN OF THE FAR WEST THROUGH THIS EVENING FOR HEAVIEST LES SNOW BEFORE SHIFTING TO MORE THE FAR WRN COUNTIES LATE AS FLOW BACKS TO NW. SNOW GROWTH WILL NOT BE IDEAL AS BUFR SOUNDINGS SHOW THE BEST OMEGA/LIFT BELOW THE DGZ. MODELS INDICATE SNOW/WATER RATIOS AVERAGED NEAR 15/1 THROUGH TONIGHT AND WITH MODEL AVERAGED QPF GEENRALLY FM .2 TO .5 INCHES...EXPECT AN ADDITIONAL 3 TO 7 INCHES OF LAKE EFFECT SNOW OVER THE FAVORED HIGHER TERRAIN UPSLOPE LOCATIONS OF THE WARNING COUNTIES. MARQUETTE AND BARAGA COUNTIES SHOULD SEE SNOW TAPERING OFF LATE TONIGHT AWAY FM LAKE SUPERIOR AS FLOW BACKS TO NW. COULD EASILY SEE THESE COUNTIES ALONG WITH THE REST OF THE WARNING COUNTIES TRANSITIONING TO LAKE EFFECT SNOW ADVISORIES ON WEDNESDAY AS LOW-LVL CONVERGENCE WEAKENS AND WINDS DIMINISH. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 518 AM EST WED NOV 12 2014 THURSDAY...EXPECT FAVORABLE LES CONDITIONS WITH 850 MB TEMPS AROUND -13C(DELTA/T OF 19C) RESULTING IN LAKE INDUCED CAPE TO 500 J/KG AND EQUILLIBRIUM HEIGHTS NEAR 10K FT DURING THE MORNING. ADDITIONAL SNOWFALL AMOUNTS OF 1 TO 3 INCHES ARE EXPECTED FOR LOCATIONS FAVORED BY 330-340 FLOW. THE HIGHER RES MODELS ALSO CONTINUE TO SHOW POTENTIAL FOR A DOMINANT BAND ORIGINATING OFF OF LAKE NIPIGON THAT WOULD IMPACT A PORTION OF ALGER COUNTY NEAR MUNISING. THIS COULD PRODUCE HIGHER SNOWFALL AMOUNTS IF THE BAND DOES NOT SHIFT. DURING THE AFTERNOON THE LES SHOULD QUICKLY DIMINISH AS MID LEVEL RIDGING AND STRONG 850-700 DRYING MOVE IN. THURSDAY NIGHT AND FRIDAY...ALTHOUGH SOME LIGHT LES WILL PERSIST AS 850 MB TEMPS REMAING NEAR -12C...THE DRY AIRMASS INTO THE REGION WITH INVERSION HEIGHTS AOB 4K FT WILL LIMIT THE INTENSITY AND KEEP ADDITIONAL ACCUMULATONS TO LESS THAN AN INCH. SAT-SUN...THE MODELS WERE IN OVERALL AGREEMENT WITH THE MID LEVEL LOW REMAINING NEAR HUDSON BAY INTO NRN MANITOBA AND A MORE ACTIVE SRN BRANCH FLOW FROM THE CNTRL PLAINS TOWARD THE SRN PLAINS. A WEAK SHORTWAVE TROUGH MOVING THROUGH THE WRN LAKES COULD BRING SOME LIGHT SNOW SHOWERS TO UPPER MI SAT NIGHT. IT SHOULD ALSO RESULT IN MORE FAVORABLE LES CONDITIONS FOR WEST FLOW FAVORED LOCATIONS WITH ADDITIONAL MOISTURE INTO THE REGION AND 850 MB TEMPS AROUND -14C. SUN NIGHT-TUE...A STRONGER SHRTWV PIVOTING AROUND THE MID LEVEL LOW WILL BRING EVEN COLDER AIR INTO THE NRN LAKES WITH 850 MB TEMPS TO AROUND -16C. THE AMPLE INSTABILTY AND DEEPER MOISTURE COULD SUPPORT MODERATE TO POSSIBLY HEAVY LES FOR NW WIND SNOW BELTS. BY TUE...THE WINDS ARE EXPECTED TO BACK MORE WRLY. TEMPS WILL REMAIN WELL BELOW NORMAL WITH HIGHS IN THE UPPER TEENS TO MID 20S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1239 AM EST WED NOV 12 2014 A MOIST...CYC SLOWLY BACKING N-NW FLOW WL BRING CONTINUED LK EFFECT SHSN AND IFR CONDITIONS AT TIMES TO THE TAF SITES THRU THIS FCST PERIOD. AS THE FLOW BACKS MORE TOWARD THE NW LATER THIS MRNG...THE WIND MAY TAP DRIER AIR SHOWN ON THE 00Z INL RAOB AND ALLOW FOR SOME IMPROVEMENT TO MVFR AT CMX AND ESPECIALLY SAW WITH DOWNSLOPE DIRECTION. BUT ENHANCED LLVL CONVERGENCE MAY RESULT IN PERSISTENT HEAVIER SHSN/IFR CONDITIONS AT IWD. THE APRCH OF ANOTHER DISTURBANCE MAY BRING ANOTHER ROUND OF HEAVIER SHSN TO IWD AND CMX THIS EVNG... BUT UNFAVORABLE FLOW FOR SAW WL LIMIT THIS POTENTIAL THERE. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 452 PM EST TUE NOV 11 2014A LOW PRESSURE SYSTEM MOVING TO NORTHERN LAKE HURON THIS EVENING AND NORTHEAST TOWARD QUEBEC TONIGHT WILL SUSTAIN NORTH TO NORTHEASTERLY GALES ACROSS CENTRAL AND EASTERN LAKE SUPERIOR INTO THE OVERNIGHT HOURS TONIGHT. GUSTY N TO NW WINDS TO 30 KNOTS SHOULD CONTINUE INTO WED WITH A FEW GALE FORCE GUSTS WED EVENING BEFORE GRADUALLY DIMINISHING THU THROUGH SAT INTO THE 15 TO 25 KNOT RANGE. AS ANOTHER AREA OF LOW PRESSURE PASS ACROSS LAKE SUPERIOR MONDAY INTO TUESDAY...EXPECT WEST TO NORTHWESTERLY WINDS OF 20 TO 30 KNOTS WITH A FEW GALE FORCE GUSTS APPROACHING 35 KNOTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST /3 PM CST/ THURSDAY FOR MIZ001>004-006-007-009-084-085. LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ005. LAKE SUPERIOR... GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LSZ266. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...JLB AVIATION...KC MARINE...KEC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1240 AM EST WED NOV 12 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 452 PM EST TUE NOV 11 2014 THE 21Z WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW STRONG SHORTWAVE OF INTEREST LIFTING E-NE THROUGH THE UPPER GREAT LAKES. STRONG DRYING AND SUBSIDENCE ON THE BACKSIDE OF THIS SHORTWAVE HAS ALLOWED THE SYSTEM SNOW TO DIMINISH OVER THE SRN TIER COUNTIES OF UPPER MI THIS AFTERNOON. LAKE EFFECT SNOW IS STILL GOING STRONG HOWEVER ALONG THE LAKE SUPERIOR COUNTIES AIDED BY A UPSLOPE NNE FLOW...THIS IS ESPECIALLY EVIDENT OVER HIGHER TERRAIN OF MQT-BARAGA COUNTIES WHERE THE RADAR SHOWS REFLECTIVITY AT OR ABV 30 DBZ. TONIGHT AND WEDNESDAY...MAIN CONCERN WAS ONGOING WSW HEADLINES. SINCE SNOW HAS ALREADY DIMINISHED ACROSS MUCH OF THE SRN TIER COUNTIES HAVE CANCELLED THE WINTER STORM WARNINGS FOR IRON THROUGH SRN SCHOOLCRAFT COUNTIES. DECIDED TO TRANSITION FM WINTER STORM WARNINGS TO LAKE EFFECT SNOW ADVISORIES OVER NRN SCHOOLCRAFT AND LUCE COUNTIES AS THE HEAVIER SYSTEM SNOW HAS EXITED EAST AND NE FLOW WILL LIMIT LES ACCUMULATION UNTIL LATER TONIGHT INTO WEDNESDAY WHEN WINDS BACK FM NNE TO MORE NW. EXPECT LES ACCUMULATION OF 2-4 INCHES TONIGHT WITH ANOTHER 1-3 INCHES ON WEDNESDAY AS 850 MB TEMPS FALL TO -13C LEADING TO LAKE DELTA-T NEAR 18C. HAVE DECIDED TO KEEP THE WINTER STORM WARNINGS GOING ELSEWHERE ACROSS THE REST OF THE WEST AND NORTH CENTRAL FCST AREA AS NNE FLOW WILL GRADUALLY BACK TO THE NW LATE TONIGHT. STRONGLY CYCLONIC UPSLOPE NNE FLOW AND DEEP MOISTURE PROFILE THROUGH 12-15 KFT WILL FAVOR MQT-BARAGA COUNTIES...PORTIONS OF THE KEWEENAW AND THE HIGHER TERRAIN OF THE FAR WEST THROUGH THIS EVENING FOR HEAVIEST LES SNOW BEFORE SHIFTING TO MORE THE FAR WRN COUNTIES LATE AS FLOW BACKS TO NW. SNOW GROWTH WILL NOT BE IDEAL AS BUFR SOUNDINGS SHOW THE BEST OMEGA/LIFT BELOW THE DGZ. MODELS INDICATE SNOW/WATER RATIOS AVERAGED NEAR 15/1 THROUGH TONIGHT AND WITH MODEL AVERAGED QPF GEENRALLY FM .2 TO .5 INCHES...EXPECT AN ADDITIONAL 3 TO 7 INCHES OF LAKE EFFECT SNOW OVER THE FAVORED HIGHER TERRAIN UPSLOPE LOCATIONS OF THE WARNING COUNTIES. MARQUETTE AND BARAGA COUNTIES SHOULD SEE SNOW TAPERING OFF LATE TONIGHT AWAY FM LAKE SUPERIOR AS FLOW BACKS TO NW. COULD EASILY SEE THESE COUNTIES ALONG WITH THE REST OF THE WARNING COUNTIES TRANSITIONING TO LAKE EFFECT SNOW ADVISORIES ON WEDNESDAY AS LOW-LVL CONVERGENCE WEAKENS AND WINDS DIMINISH. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 452 PM EST TUE NOV 11 2014 COLD WEATHER PATTERN EXPECTED TO CONTINUE INTO NEXT WEEK WITH INTERMITTENT LAKE EFFECT SNOW WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...THE LARGE SURFACE AND UPPER LEVEL LOW PRESSURE SYSTEM THAT BROUGHT ALL OF THE SNOWFALL TO THE U.P. OVER THE PAST COUPLE OF DAYS WILL BE CENTERED NEAR JAMES BAY WEDNESDAY NIGHT. A SECONDARY TROUGH IS EXPECTED TO SWING THROUGH THE AREA WEDNESDAY NIGHT THROUGH THURSDAY BEFORE SLOWLY EXITING THE REGION BY THURSDAY NIGHT AS THE MAIN LOW SHIFTS FARTHER NORTH AND EAST INTO NORTHERN QUEBEC. DEEP LAYER MOISTURE WILL REMAIN IN PLACE THROUGH THURSDAY EVENING AS SHOWN BY ANALYZING 1000-500MB RH. THIS ALONG WITH ENHANCED CONVERGENCE ASSOCIATED WITH THE TROUGH PASSING ACROSS THE AREA WILL ALLOW FOR INCREASED LAKE EFFECT ACROSS THE REGION. THE BETTER FORCING ASSOCIATED WITH THE TROUGH WILL REMAIN OVER LAKE SUPERIOR AND ALONG THE LAKE SUPERIOR SHORELINE. ADDITIONALLY...THE COLDER AIR ALOFT ASSOCIATED WITH THE UPPER LEVEL 500MB TROUGH...WILL ALLOW DELTA T VALUES TO INCREASE TO 18 TO 20C...WHICH WILL BE MORE THAN SUFFICIENT FOR LAKE EFFECT SNOW. AS THIS COLDER AIR PUSHES ACROSS...THIS WILL ALLOW INVERSION HEIGHTS TO INCREASE TO 8 TO 10KFT...ALONG WITH CONTINUED MOISTURE IN THE DGZ... ALLOWING FOR BETTER SNOW GROWTH. THE LAKE EFFECT SNOWFALL WILL BE LARGELY FOCUSED IN THE NORTHWEST WIND FAVORED SNOWBELTS OF THE U.P. WITH THE HIGHER TERRAIN OF THE WESTERN U.P. SEEING SOME OF THE GREATER TOTALS ALONG WITH AREAS EAST OF THE HARVEY AND MARQUETTE AREAS OUT TO NEAR GRAND MARAIS DUE TO THE INCREASED FETCH ASSOCIATED WITH THE NORTHWESTERLY WINDS. SOME AREAS COULD SEE TOTALS APPROACH A FOOT NEAR MUNISING AND EAST. BLOWING SNOW WILL ALSO BE AN ISSUE CLOSE TO THE LAKE SUPERIOR SHORELINE AS THE SNOW RATIOS INCREASE. A HEADLINE MAY BE NEEDED FOR THIS LAKE EFFECT EVENT...ESPECIALLY FOR ALGER...NORTHERN SCHOOLCRAFT AND LUCE COUNTIES. WILL HOLD OFF AT THIS POINT TO KEEP FROM HAVING MULTIPLE HEADLINES OUT FOR THE SAME COUNTIES. FRIDAY INTO FRIDAY NIGHT...AS THE CYCLONIC FLOW SHIFTS SLOWLY OUT OF THE AREA AND IS REPLACED BY A SURFACE RIDGE SLIDING NORTH AND EASTWARD FROM MISSOURI...EXPECT THE LAKE EFFECT SNOW TO SLOWLY DIMINISH TO ISOLATED SNOW SHOWERS. THE GFS/EC/NAM ARE ALL HINTING AT DRIER AIR PUSHING IN WITH THIS RIDGE...WHICH WILL AGAIN HELP TO LIMIT THE LAKE EFFECT POTENTIAL. AT THIS POINT ONLY MINOR ACCUMULATIONS MAY BE POSSIBLE THROUGH THIS TIME PERIOD. SATURDAY THROUGH SUNDAY NIGHT...A DEEP UPPER LEVEL LOW IS PROGGED TO DEVELOP OVER HUDSON BAY ALLOWING AN UPPER LEVEL 500MB TROUGH TO EXTEND SOUTHWESTWARD INTO THE NORTHERN PLAINS SATURDAY MORNING. THIS LOW WILL REMAIN NEARLY STATIONARY AS THE ASSOCIATED TROUGH SWINGS EASTWARD INTO THE UPPER GREAT LAKES REGION. AT THE SURFACE...A SURFACE LOW WILL BE POSITIONED OVER HUDSON BAY WHILE AN ADDITIONAL LOW DEVELOPS NEAR THE PANHANDLE OF TEXAS. HIGH PRESSURE WILL BE CENTERED OVER MONTANA...WHILE ANOTHER HIGH REMAINS PARKED OVER THE NORTHEAST. THIS WOULD PUT THE PLAINS AND UPPER MISSISSIPPI VALLEY REGION IN A SADDLE POINT REGION WHICH WOULD FAVOR AT LEAST WEAK F-GEN. THIS IS ALSO INDICATED BY ANALYZING 850MB THETA-E ALONG WITH ASSOCIATED WIND SHIFT IN THAT LAYER. ADDITIONALLY...WITH TROUGH PASSING OVERHEAD...EXPECT DELTA-T VALUES TO INCREASE ONCE AGAIN TO AROUND 18 TO 20C ACROSS THE AREA. THE BEST CHANCE FOR LAKE ENHANCEMENT WOULD BE OVER THE WEST WIND FAVORED AREAS...ESPECIALLY LATE SATURDAY NIGHT THROUGH SUNDAY. MONDAY THROUGH THE REMAINING EXTENDED...EXPECT CONTINUED BROAD TROUGHING ACROSS THE UPPER GREAT LAKES REGION WITH THE POTENTIAL FOR ANOTHER SURFACE LOW PRESSURE SYSTEM TO PASS THROUGH THE REGION. THIS WILL ALLOW CONTINUED LAKE EFFECT SNOW CHANCES FOR MAINLY WEST TO NORTHWEST WIND FAVORED LOCATIONS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1239 AM EST WED NOV 12 2014 A MOIST...CYC SLOWLY BACKING N-NW FLOW WL BRING CONTINUED LK EFFECT SHSN AND IFR CONDITIONS AT TIMES TO THE TAF SITES THRU THIS FCST PERIOD. AS THE FLOW BACKS MORE TOWARD THE NW LATER THIS MRNG...THE WIND MAY TAP DRIER AIR SHOWN ON THE 00Z INL RAOB AND ALLOW FOR SOME IMPROVEMENT TO MVFR AT CMX AND ESPECIALLY SAW WITH DOWNSLOPE DIRECTION. BUT ENHANCED LLVL CONVERGENCE MAY RESULT IN PERSISTENT HEAVIER SHSN/IFR CONDITIONS AT IWD. THE APRCH OF ANOTHER DISTURBANCE MAY BRING ANOTHER ROUND OF HEAVIER SHSN TO IWD AND CMX THIS EVNG... BUT UNFAVORABLE FLOW FOR SAW WL LIMIT THIS POTENTIAL THERE. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 452 PM EST TUE NOV 11 2014A LOW PRESSURE SYSTEM MOVING TO NORTHERN LAKE HURON THIS EVENING AND NORTHEAST TOWARD QUEBEC TONIGHT WILL SUSTAIN NORTH TO NORTHEASTERLY GALES ACROSS CENTRAL AND EASTERN LAKE SUPERIOR INTO THE OVERNIGHT HOURS TONIGHT. GUSTY N TO NW WINDS TO 30 KNOTS SHOULD CONTINUE INTO WED WITH A FEW GALE FORCE GUSTS WED EVENING BEFORE GRADUALLY DIMINISHING THU THROUGH SAT INTO THE 15 TO 25 KNOT RANGE. AS ANOTHER AREA OF LOW PRESSURE PASS ACROSS LAKE SUPERIOR MONDAY INTO TUESDAY...EXPECT WEST TO NORTHWESTERLY WINDS OF 20 TO 30 KNOTS WITH A FEW GALE FORCE GUSTS APPROACHING 35 KNOTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER STORM WARNING UNTIL 7 AM EST /6 AM CST/ THIS MORNING FOR MIZ001>004-009-084. WINTER STORM WARNING UNTIL 10 AM EST THIS MORNING FOR MIZ005-006. LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ007- 085. LAKE SUPERIOR... GALE WARNING UNTIL 1 AM EST EARLY THIS MORNING FOR LSZ267. GALE WARNING UNTIL 4 AM EST EARLY THIS MORNING FOR LSZ266. GALE WARNING UNTIL 3 AM EST EARLY THIS MORNING FOR LSZ264-265. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...KEC AVIATION...KC MARINE...KEC
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1145 PM CST Tue Nov 11 2014 .UPDATE: Issued at 621 PM CST Tue Nov 11 2014 Have updated overnight forecast to increase cloud cover across the region. Have low confidence in most of the guidance given recent trends. However, the RAP seems to have the best handle on current trends, which keeps the area cloudy thru much of the night. Given area of clouds upstream in IA, believe clouds will continue to advect into the region. Some question about far srn tier or two of counties where clouds may continue to break up thru the evening. Overall, this shud have little impact in the forecast as continuing CAA will help cool temps into the low 20s. Tilly && .SHORT TERM: (Through Late Tonight) Issued at 345 PM CST Tue Nov 11 2014 Northwest flow and strong cold advection is bringing an Arctic airmass down into the Great Plains and Midwest. Temperatures are between 25 and 40 degrees colder now than they were at this time yesterday. Cold advection will continue overnight and expect some of the coldest temperatures yet this Fall. Lows tonight ranging from the upper teens to low and mid 20s will feel more like late December or early January than mid November. Not in danger of breaking any record lows though as STL`s record for November 12 is 12, COU is 9, and UIN is 10. Clouds are going to be tough to forecast tonight as most of the operational guidance is clueless. Am leaning heavily on the RAP and experimental NARRE for cloud forecast tonight. Generally...expect any clearing from the south and west to slow and finally stop this evening as cold advection continues, and a gradual increase in low level clouds as low level RH continues to advect from the north. Unfortunately...specifics are somewhat murky at this time, but I expect the majority of the area to stay cloudy or mostly cloudy tonight. Carney .LONG TERM: (Wednesday through Next Tuesday) Issued at 345 PM CST Tue Nov 11 2014 (Wednesday - Friday) Continue to favor the RAP model for lo level moisture and clouds, and this strongly favors the lo clouds remaining for at least part of Wednesday...perhaps beyond. Otherwise, a dry column--especially below 500mb--accompanied with unusually cold air will prevail during this period. The only disturbance to impact the area during this time will be the tail-end of a vort lobe from late Wednesday thru early Thursday. Given the very open structure of this wave and the column it has to act upon, do not foresee anything more than hi and some mid cloud moving thru with continued dry wx. Look for max temps in the lo-mid 30s with min temps from 15-25 should be common. Much of this stretch will feature max temps that are 20-25 degrees below normal! (Saturday - Sunday) A better signal for a disturbance remains set for this period, although there are no gimmes with this either. Models are now advertising a more stout shortwave for late Saturday night and Sunday, along with disturbances out ahead of it set for Saturday daytime. Moisture thru the column will continue to be at low supply, but when dealing with a cold airmass of this type, it will not take much if the forcing is strong enough. It is looking more favorable for what will probably be a short-lived event for the weekend, and it still looks to be mostly snow. But the details on when enough saturation can occur and when still remain murky, and so still not going any higher than chance category at this point. This event will be then followed by another shot of cold air for late Saturday night and Sunday. (Monday - Next Tuesday) Deep cyclonic flow will be in place but position in relation to the main LOW to the north and lack of non-heavily sheared disturbances will at this time preclude pcpn mention and favor a dry forecast. The cold will continue, with the blocking pattern not changing in western North America and the next round of reinforcing cold will be set to move in later on Monday and continue into Tuesday. TES && .AVIATION: (For the 06z TAFs through 06z Wednesday Night) Issued at 1119 PM CST Tue Nov 11 2014 MVR CIGS continue to dominate the region thru the night. The question then becomes about when the CIGS dsspt. Model guidance is not handling this situation very well so this is a fairly low confidence fcst wrt timing. Current thinking is that the stratocu will slowly erode thru the day. NW winds will maintain thru the prd as a strong sfc high continues to build into the region. Specifics for KSTL: MVFR CIGS to slowly erode during the aftn. Due to poor model performance this will be a low confidence fcst wrt timing of the dssptn of the MVFR CIGS. Winds will remain out of the NW as a strong sfc ridge builds into the area. 2% && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
934 PM EST THU NOV 13 2014 .SYNOPSIS... LOW PRESSURE WILL MOVE ALONG THE NORTH CAROLINA COAST TONIGHT. A STRONG COLD FRONT WILL MOVE THROUGH EARLY FRIDAY PROVIDING A REINFORCING SHOT OF COLD AIR. HIGH PRESSURE WILL DOMINATE SATURDAY THEN SHIFT OFFSHORE SUNDAY. ANOTHER COLD FRONT WILL MOVE THROUGH THE AREA LATE MONDAY. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... AS OF 930 PM THURSDAY...BAND OF LIGHT RAIN MOVING NORTHEAST ACROSS SOUTHERN SECTIONS OF THE CWA AND SHOULD GRADUALLY MOVE ACROSS THE NORTHERN OUTER BANKS AND OFFSHORE BETWEEN ROUGHLY 08Z AND 10Z PER LATEST 3KM HRRR MODEL AS LOW PRESSURE MOVES EAST OF THE AREA. COOLER AIR CONTINUES TO FILTER TOWARD THE COAST WITH MOST AREAS NOW IN THE 40S WITH LOWER 50S AT HATTERAS AND BEAUFORT. STILL NO CHANGES IN OVERNIGHT TEMPS WITH UPPER 30S TO MID 40S BY MORNING. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... AS OF 3 PM THU...SFC LOW WILL CONTINUE TO LIFT OFF THE NE COAST AS SFC HIGH BUILDS INTO THE AREA FROM THE WEST. MOST OF PRECIP SHOULD BE OFFSHORE THOUGH COULD SEE STILL SOME WRAP AROUND LIGHT RAIN/DRIZZLE ACROSS THE OUTER BANKS EARLY. LOW LEVEL THICKNESS VALUES AND NORTHERLY FLOW SUPPORT HIGHS IN THE UPPER 40S TO AROUND 50 DEGREES...ABOUT 20 DEGREES BELOW NORMAL. COOL TEMPS COMBINED WITH GUSTY WINDS WILL RESULT IN WIND CHILL VALUES IN THE LOW 40S. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... AS OF 1258 PM THU...NEARLY ZONAL FLOW IN THE MID LEVELS WILL START THE WEEKEND. MODELS AGREE ON 8H TEMPERATURES -2 TO -6C ACROSS THE AREA SATURDAY MORNING IN NORTHERLY FLOW AROUND A STRONG SURFACE HIGH PRESSURE OVER THE OHIO RIVER VALLEY BRINGING ARCTIC AIR TO THE AREA. HARD FREEZE EXPECTED ACROSS THE AREA AWAY FROM THE WATERS. FREEZE WATCH HAS BEEN ISSUED FOR COASTAL COUNTIES FRIDAY NIGHT. FORECAST TEMPERATURES ARE JUST AT FREEZING IN THOSE AREAS. CONTINUED NORTHERLY FLOW WILL KEEP AFTERNOON HIGH TEMPERATURES ONLY IN THE UPPER 40S SURFACE RIDGE AXIS WILL MOVE OFFSHORE SATURDAY ALLOWING LOW LEVEL FLOW TO BECOME SOUTHERLY BY SUNRISE SUNDAY. THIS WILL BUMP HIGH TEMPERATURES BACK INTO THE 50S SUNDAY AFTERNOON. COASTAL TROUGH WILL FORM SUNDAY AFTERNOON AS MID LEVEL TROUGH DIGS INTO THE PLAINS STATES. NOT AN AWFUL LOT OF ENERGY ASSOCIATED WITH THIS AND PWS WILL REMAIN BELOW AN INCH. MOST PRECIPITATION WILL BE ALONG THE COAST WITH TRACK OF SURFACE LOW PRESSURE. LOW PRESSURE WILL FORM ALONG THE GULF COAST SUNDAY AS UPPER TROUGH MOVES SLOWLY TOWARD THE EAST. ASSOCIATED FRONTAL SYSTEM WILL BRING CONTINUED CHANCES FOR PRECIPITATION THROUGH MONDAY NIGHT. COLD AIR ADVECTION BEHIND THE FRONT WITH ANOTHER ARCTIC SURGE WILL BRING ANOTHER HARD FREEZE TO THE AREA TUESDAY NIGHT AND AFTERNOON HIGH TEMPERATURES IN TO 40S WEDNESDAY. AIR MASS WILL REMAIN DRY THROUGH THE END OF THE PERIOD. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... SHORT TERM /THROUGH FRIDAY/... AS OF 935 PM THURSDAY...EXPECT CEILINGS TO GRADUALLY LIFT TO MVFR AT ALL TAF SITES THROUGH THE EARLY MORNING HOURS. KEWN AND KPGV CONTINUE IN IFR...BUT KOAJ/KISO ARE MVFR. PATCHY LIGHT RAIN WILL CONTINUE FOR THE NEXT SEVERAL HOURS...BUT DO NOT EXPECT VSBYS BELOW 6 MILES AT THIS TIME. GOOD MIXING EXPECTED BY LATE TONIGHT AS WINDS BECOME NORTHERLY AT 15-25 KNOTS LATE TONIGHT AND CONTINUE THROUGH FRIDAY. LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 105 PM THU...VFR CONDITIONS WITH DRY ARCTIC HIGH PRESSURE OVER THE AREA INTO SUNDAY. COASTAL TROUGH WILL BRING SOME RAIN AND POSSIBLY SOME SUB VFR CONDITIONS LATE SUNDAY INTO MONDAY. FRONTAL SYSTEM WILL DEVELOP IN THE GULF COAST STATES AND BRING THE POSSIBILITY OF SOME SUB VFR CONDITIONS MONDAY AND MONDAY NIGHT IN ASSOCIATED RAIN AS THE FRONT MOVES THROUGH EASTERN NORTH CAROLINA THROUGH MONDAY NIGHT. && .MARINE... SHORT TERM /THROUGH FRIDAY/... AS OF 935 PM THURSDAY...NORTHWEST WINDS BECOMING INCREASINGLY GUSTY OVER THE NORTHERN WATERS WITH DUCK GUSTING TO 26 KNOTS. SHOULD SEE WIDESPREAD NORTHWEST/NORTH WINDS 20 TO 25 KNOTS WITH A FEW GUSTS TO 30 KNOTS WORK FROM NORTH TO SOUTH OVER THE NEXT 2 TO 4 HOURS AS LOW PRESSURE MOVES OFFSHORE AND STRENGTHENS OFF THE MID-ATLANTIC COAST OVERNIGHT INTO EARLY FRIDAY MORNING. NWPS AND WAVEWATCH IN GOOD AGREEMENT WITH SEAS BUILDING TO 5-8FT HIGHEST NORTH OF OCRACOKE. GUSTY WINDS WILL CONTINUE FOR FRI...SLOWLY DIMINISHING LATE AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST. SCA CONTINUE FOR ALL WATERS FOR GUSTY WINDS AND ELEVATED SEAS. STRONG NRLY WINDS AND NELY SWELL MAY RESULT IN ELEVATED WATER LEVELS ON NRN OUTER BANKS FRI...ESPECIALLY NEAR HIGH TIDE AROUND NOON. MINOR OVERWASH AND BEACH EROSION WILL BE POSSIBLE. LATEST EXTRA-TROPICAL SURGE GDNC INDICATES WATER LEVELS ONLY AROUND A FOOT ABOVE NORMAL...THUS DO NOT ANTICIPATE COASTAL FLOOD ADVISORY ISSUANCES AT THIS TIME...BUT COULD SEE SPS FOR LOCALIZED PROBLEMS. LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 122 PM THU..HIGH PRESSURE WELL TO THE WEST OF THE NORTH CAROLINA COASTAL WATERS FRIDAY NIGHT WITH NORTHERLY FLOW OVER THE WATERS. SMALL CRAFT ADVISORY IS IN EFFECT FOR THE WATERS THROUGH THE NIGHT. GRADIENT WILL RELAX THROUGH THE DAY SATURDAY AS THE SURFACE RIDGE AXIS APPROACHES THE WATERS...ALLOWING NORTH AND NORTHWESTERLY WINDS AND SEAS TO FALL BELOW SCA CRITERION DURING THE MORNING HOURS. AS THE RIDGE AXIS CROSSES THE WATERS SATURDAY NIGHT...WIND WILL BECOME SOUTHEASTERLY. A COASTAL TROUGH WILL FORM LATE SUNDAY AND ASSOCIATED LOW PRESSURE WILL MOVE ALONG THE COAST SUNDAY NIGHT. SOUTHEASTERLY FLOW WILL BECOME SOUTHWESTERLY WITH SPEEDS AND SEAS NEAR SMALL CRAFT ADVISORY CRITERIA. FRONTAL SYSTEM WILL FORM ALONG THE GULF COAST STATES LATE SUNDAY AND APPROACH THE NORTH CAROLINA COASTAL WATERS MONDAY. GRADIENT WILL AGAIN TIGHTEN AHEAD OF THIS SYSTEM...NEARING SMALL CRAFT ADVISORY CRITERION MONDAY AFTERNOON. SOUTHWEST WIND AHEAD OF THE FRONT WILL BECOME NORTHWESTERLY BEHIND THE FRONT MONDAY NIGHT. GRADIENT WILL REMAIN TIGHT TUESDAY...WITH WIND AND SEAS NEAR SMALL CRAFT ADVISORY LEVELS DURING THE DAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING FOR NCZ046-047-081-094-095. MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST FRIDAY FOR AMZ130-131- 135>137. SMALL CRAFT ADVISORY UNTIL 10 AM EST SATURDAY FOR AMZ150-152- 154. SMALL CRAFT ADVISORY FROM 1 AM FRIDAY TO 5 AM EST SATURDAY FOR AMZ156-158. && $$ SYNOPSIS...CQD/DAG NEAR TERM...CTC SHORT TERM...CQD LONG TERM...CGG AVIATION...CGG/CTC/CQD MARINE...CGG/CTC/CQD
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
709 PM EST THU NOV 13 2014 .SYNOPSIS... LOW PRESSURE WILL MOVE ALONG THE NORTH CAROLINA COAST TONIGHT. A STRONG COLD FRONT WILL MOVE THROUGH EARLY FRIDAY PROVIDING A REINFORCING SHOT OF COLD AIR. HIGH PRESSURE WILL DOMINATE SATURDAY THEN SHIFT OFFSHORE SUNDAY. ANOTHER COLD FRONT WILL MOVE THROUGH THE AREA LATE MONDAY. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... AS OF 7 PM THURSDAY...INITIAL AREA OF RAIN MOVING OFF THE OUTER BANKS AND SOUTH COAST...WITH ADDITIONAL VERY LIGHT RAIN APPROACHING OUR SOUTHWESTERN COUNTIES. THIS PRECIPITATION IS WELL DEPICTED BY THE 3KM HRRR MODEL AND HAVE GENERALLY FOLLOWED THIS MODEL FOR THE OVERNIGHT UPDATE. ANTICIPATE THE RAIN TO GRADUALLY DISSIPATE FROM SOUTHWEST TO NORTHEAST BETWEEN 08Z AND 10Z FRIDAY MORNING. COOLER AIR FILTERING INTO OUR NORTHERN AND WESTERN COUNTIES WITH KPGV AND KOCW DOWN TO 46 AND KISO DOWN TO 48 DEGREES. NO CHANGES IN OVERNIGHT TEMPS WITH UPPER 30S TO MID 40S BY MORNING. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... AS OF 3 PM THU...SFC LOW WILL CONTINUE TO LIFT OFF THE NE COAST AS SFC HIGH BUILDS INTO THE AREA FROM THE WEST. MOST OF PRECIP SHOULD BE OFFSHORE THOUGH COULD SEE STILL SOME WRAP AROUND LIGHT RAIN/DRIZZLE ACROSS THE OUTER BANKS EARLY. LOW LEVEL THICKNESS VALUES AND NORTHERLY FLOW SUPPORT HIGHS IN THE UPPER 40S TO AROUND 50 DEGREES...ABOUT 20 DEGREES BELOW NORMAL. COOL TEMPS COMBINED WITH GUSTY WINDS WILL RESULT IN WIND CHILL VALUES IN THE LOW 40S. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... AS OF 1258 PM THU...NEARLY ZONAL FLOW IN THE MID LEVELS WILL START THE WEEKEND. MODELS AGREE ON 8H TEMPERATURES -2 TO -6C ACROSS THE AREA SATURDAY MORNING IN NORTHERLY FLOW AROUND A STRONG SURFACE HIGH PRESSURE OVER THE OHIO RIVER VALLEY BRINGING ARCTIC AIR TO THE AREA. HARD FREEZE EXPECTED ACROSS THE AREA AWAY FROM THE WATERS. FREEZE WATCH HAS BEEN ISSUED FOR COASTAL COUNTIES FRIDAY NIGHT. FORECAST TEMPERATURES ARE JUST AT FREEZING IN THOSE AREAS. CONTINUED NORTHERLY FLOW WILL KEEP AFTERNOON HIGH TEMPERATURES ONLY IN THE UPPER 40S SURFACE RIDGE AXIS WILL MOVE OFFSHORE SATURDAY ALLOWING LOW LEVEL FLOW TO BECOME SOUTHERLY BY SUNRISE SUNDAY. THIS WILL BUMP HIGH TEMPERATURES BACK INTO THE 50S SUNDAY AFTERNOON. COASTAL TROUGH WILL FORM SUNDAY AFTERNOON AS MID LEVEL TROUGH DIGS INTO THE PLAINS STATES. NOT AN AWFUL LOT OF ENERGY ASSOCIATED WITH THIS AND PWS WILL REMAIN BELOW AN INCH. MOST PRECIPITATION WILL BE ALONG THE COAST WITH TRACK OF SURFACE LOW PRESSURE. LOW PRESSURE WILL FORM ALONG THE GULF COAST SUNDAY AS UPPER TROUGH MOVES SLOWLY TOWARD THE EAST. ASSOCIATED FRONTAL SYSTEM WILL BRING CONTINUED CHANCES FOR PRECIPITATION THROUGH MONDAY NIGHT. COLD AIR ADVECTION BEHIND THE FRONT WITH ANOTHER ARCTIC SURGE WILL BRING ANOTHER HARD FREEZE TO THE AREA TUESDAY NIGHT AND AFTERNOON HIGH TEMPERATURES IN TO 40S WEDNESDAY. AIR MASS WILL REMAIN DRY THROUGH THE END OF THE PERIOD. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... SHORT TERM /THROUGH FRIDAY/... AS OF 705 PM THURSDAY...EXPECT CEILINGS TO GRADUALLY LIFT TO MVFR AT ALL TAF SITES THROUGH LATE EVENING. PATCHY LIGHT RAIN WILL CONTINUE FOR THE NEXT SEVERAL HOURS...BUT DO NOT EXPECT VSBYS BELOW 6 MILES AT THIS TIME. CURRENTLY KEWN/KOAJ STILL AT IFR WITH CEILINGS JUST BELOW 1000 FEET...BUT EXPECT THESE TO IMPROVE TO 1500 FEET IN THE NEXT 3 TO 5 HOURS. GOOD MIXING EXPECTED BY LATE TONIGHT AS WINDS BECOME NORTHERLY AT 15-25 KNOTS LATE TONIGHT AND CONTINUE THROUGH FRIDAY. LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 105 PM THU...VFR CONDITIONS WITH DRY ARCTIC HIGH PRESSURE OVER THE AREA INTO SUNDAY. COASTAL TROUGH WILL BRING SOME RAIN AND POSSIBLY SOME SUB VFR CONDITIONS LATE SUNDAY INTO MONDAY. FRONTAL SYSTEM WILL DEVELOP IN THE GULF COAST STATES AND BRING THE POSSIBILITY OF SOME SUB VFR CONDITIONS MONDAY AND MONDAY NIGHT IN ASSOCIATED RAIN AS THE FRONT MOVES THROUGH EASTERN NORTH CAROLINA THROUGH MONDAY NIGHT. && .MARINE... SHORT TERM /THROUGH FRIDAY/... AS OF 705 PM THURSDAY...WIND SHIFT TO THE NORTH HAS REACHED CAPE LOOKOUT AND SHOULD CONTINUE SOUTH OVER THE NEXT COUPLE OF HOURS. PER BOUNDARY LAYER WIND GUIDANCE...EXPECT GUSTY NORTHWEST WINDS OF 20 TO 25 KNOTS WITH GUSTS TO 30 KNOTS ON THE SOUNDS AND COASTAL WATERS BY 03Z-05Z AS LOW PRESSURE AREA CENTERED OVER NE SC/SE NC LIFTS NORTHEASTWARD ACROSS THE COASTAL WATERS STRENGTHENING OFF THE MID- ATLANTIC COAST OVERNIGHT INTO EARLY FRIDAY MORNING. NWPS AND WAVEWATCH IN GOOD AGREEMENT WITH SEAS BUILDING TO 5-8FT HIGHEST NORTH OF OCRACOKE. GUSTY WINDS WILL CONTINUE FOR FRI...SLOWLY DIMINISHING LATE AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST. SCA CONTINUE FOR ALL WATERS FOR GUSTY WINDS AND ELEVATED SEAS. STRONG NRLY WINDS AND NELY SWELL MAY RESULT IN ELEVATED WATER LEVELS ON NRN OUTER BANKS FRI...ESPECIALLY NEAR HIGH TIDE AROUND NOON. MINOR OVERWASH AND BEACH EROSION WILL BE POSSIBLE. LATEST EXTRA-TROPICAL SURGE GDNC INDICATES WATER LEVELS ONLY AROUND A FOOT ABOVE NORMAL...THUS DO NOT ANTICIPATE COASTAL FLOOD ADVISORY ISSUANCES AT THIS TIME...BUT COULD SEE SPS FOR LOCALIZED PROBLEMS. LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 122 PM THU..HIGH PRESSURE WELL TO THE WEST OF THE NORTH CAROLINA COASTAL WATERS FRIDAY NIGHT WITH NORTHERLY FLOW OVER THE WATERS. SMALL CRAFT ADVISORY IS IN EFFECT FOR THE WATERS THROUGH THE NIGHT. GRADIENT WILL RELAX THROUGH THE DAY SATURDAY AS THE SURFACE RIDGE AXIS APPROACHES THE WATERS...ALLOWING NORTH AND NORTHWESTERLY WINDS AND SEAS TO FALL BELOW SCA CRITERION DURING THE MORNING HOURS. AS THE RIDGE AXIS CROSSES THE WATERS SATURDAY NIGHT...WIND WILL BECOME SOUTHEASTERLY. A COASTAL TROUGH WILL FORM LATE SUNDAY AND ASSOCIATED LOW PRESSURE WILL MOVE ALONG THE COAST SUNDAY NIGHT. SOUTHEASTERLY FLOW WILL BECOME SOUTHWESTERLY WITH SPEEDS AND SEAS NEAR SMALL CRAFT ADVISORY CRITERIA. FRONTAL SYSTEM WILL FORM ALONG THE GULF COAST STATES LATE SUNDAY AND APPROACH THE NORTH CAROLINA COASTAL WATERS MONDAY. GRADIENT WILL AGAIN TIGHTEN AHEAD OF THIS SYSTEM...NEARING SMALL CRAFT ADVISORY CRITERION MONDAY AFTERNOON. SOUTHWEST WIND AHEAD OF THE FRONT WILL BECOME NORTHWESTERLY BEHIND THE FRONT MONDAY NIGHT. GRADIENT WILL REMAIN TIGHT TUESDAY...WITH WIND AND SEAS NEAR SMALL CRAFT ADVISORY LEVELS DURING THE DAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING FOR NCZ046-047-081-094-095. MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 7 PM EST FRIDAY FOR AMZ130-131-135>137. SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 10 AM EST SATURDAY FOR AMZ150-152-154. SMALL CRAFT ADVISORY FROM 1 AM FRIDAY TO 5 AM EST SATURDAY FOR AMZ156-158. && $$ SYNOPSIS...CQD/DAG NEAR TERM...CTC SHORT TERM...CQD LONG TERM...CGG AVIATION...CGG/CTC/CQD MARINE...CGG/CTC/CQD
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1241 PM EST WED NOV 12 2014 .SYNOPSIS... A PROLONGED PERIOD OF BELOW NORMAL TEMPERATURES WILL COMMENCE TODAY AND CONTINUE THROUGHOUT MUCH OF NEXT WEEK AS A LARGE POOL OF UNSEASONABLY COLD AIR OVER THE EASTERN TWO THIRDS OF THE UNITED STATES BECOMES ENTRENCHED. IT WILL LARGELY BE A DRY PATTERN FOR THE OHIO VALLEY...THOUGH A WEATHER SYSTEM SHIFTING THROUGH ON SUNDAY AND SUNDAY NIGHT WILL BRING THE THREAT OF SOME SNOW TO THE AREA...PERHAPS MIXING WITH OR CHANGING TO RAIN ACROSS KENTUCKY AND SOUTHEAST OHIO. WITHIN THE LONGER DURATION PERIOD OF BELOW NORMAL TEMPERATURES...WILL BE TWO PERIODS WHEN IT WILL BE PARTICULARLY CHILLY. THESE TWO PERIODS WILL BE THURSDAY AND FRIDAY OF THIS WEEK...WITH HIGHS IN THE LOWER AND MIDDLE 30S...AND MONDAY AND TUESDAY OF NEXT WITH SIMILAR OR EVEN SLIGHTLY COLDER HIGHS WHICH MAY NOT ESCAPE THE 20S FOR SOME PARTS OF THE AREA. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LATEST VIS IMAGERY ACROSS THE REGION DEPICTED AN EXPANSIVE AREA OF STRATOCUMULUS CLOUDS EXTENDING FROM THE SOUTHERN GREAT LAKES SOUTHWARD TO THE TN RIVER VALLEY AND THEN WESTWARD TOWARD THE MID MS VALLEY. THE 12.12Z KILN SOUNDING SHOWS THAT THIS CLOUD DECK IS NEAR THE 900 MB LEVEL. THE MOISTURE IS ALSO TRAPPED UNDER A STRONG SUBSIDENCE INVERSION. THE FORECAST DILEMMA FOR TODAY WILL BE WHETHER THE STRATOCUMULUS CLOUDS PERSISTENT OVER THE REGION OR WHETHER THEY SCOUR/ERODE. THE MOISTURE NEAR 900 MB IS FAIRLY THIN (925 MB-875 MB LAYER). SOME PIREPS RECEIVED FROM THIS MORNING ALSO INDICATE THAT THIS DECK IS ABOUT 1000 FEET THICK. THIS IS A PLUS FOR WANTING THE CLOUDS TO ERODE WITH SOME DIURNAL HEATING WORKING IN TANDEM WITH WEAK ANTICYCLONIC FLOW IN THE LOW LEVELS. THIS SCENARIO IS BEING FORECAST BY THE LATEST RAP MODEL EITHER THROUGH POINT SOUNDINGS OR FORECAST CEILING HEIGHTS. ON THE OTHER HAND...THE MODEL COULD JUST BE A BIT AMBITIOUS AND THE CLOUDS COULD END UP LINGERING ALL DAY. THUS...HAVE TAKEN A BLEND AT THIS POINT WHICH IS TO ALLOW SKIES TO BECOME PARTLY CLOUDY BY LATE AFTN/EARLY EVENING AND WILL MONITOR CLOUD TRENDS . FORECAST HIGHS IN THE UPPER 30S TO THE LOWER 40S LOOK GOOD AT THIS POINT. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... TONIGHT...UPSTREAM SHORTWAVE TROUGH OVER SD/MN WILL ROTATE SOUTHEAST INTO MI/IL AS THE PRIMARY WAVE THAT PASSED THROUGH THE AREA TUESDAY NIGHT CONTINUES TO EJECT NORTHEAST INTO AREAS EAST OF HUDSON BAY. THERE IS SOME MID/UPPER LEVEL FORCING WITH THE APPROACHING WAVE LATER TONIGHT...AND THIS FORCING CROSSES MAINLY CNTL/WRN OH DURING THE MORNING HOURS ON THURSDAY. THIS SHOWN NICELY IN 90KM Q-VECTORS CONVERGENCE MAXIMA ROTATING ACROSS THE NRN FORECAST AREA LATE TONIGHT INTO EARLY THURSDAY AFTN COINCIDENT WITH WEAK MID LEVEL VERTICAL MOTION. SHOULD BE A HEALTHY MID DECK OF CLOUDS WITH THIS FORCING...OUT OF WHICH A FEW FLURRIES OR PATCHES OF LIGHT SNOW COULD FIND THEIR WAY TO THE SURFACE OVER CNTL OHIO...BUT DRY SUB-CLOUD LAYERS SHOULD MITIGATE THE NEED FOR A MEASURABLE POP. JUST NOT SEEING ANY SUFFICIENT LOWER LEVEL FORCING OR MOISTURE TO WORK WITH THIS WAVE. THE PASSING OF THIS WAVE WILL ALLOW A BETTER FLOW OF COLDER AIR INTO THE FORECAST AREA THURSDAY NIGHT INTO FRIDAY. IN FACT...BY SUNRISE ON FRIDAY 850MB TEMPS WILL HAVE FALLEN TO -12C TO -15C ACROSS THE AREA WHICH IS AROUND 2 SIGMA BELOW CLIMO FOR NRN KY/SRN OHIO. KEPT HIGH TEMPERATURES RIGHT WHERE THEY WERE FOR BOTH THURSDAY AND FRIDAY. PRETTY CHILLY BOTH DAYS WITH HIGHS IN THE LOWER/MID 30S. WHILE TOTAL TROPOSPHERIC MOISTURE WILL DECREASE AS THE WAVE PASSES THURSDAY MORNING INTO EARLY THURSDAY AFTERNOON...STILL THINK LOW CLOUDS WILL BE PESKY DUE TO RE-STEEPENING OF THE LAPSE RATES WITH THE COLDER AIR FLOWING IN AND A MORE CYCLONIC FLOW. 12.00Z FCST SOUNDINGS FROM NAM/GFS STILL HINTING THAT LOW CLOUDS COULD HANG INTO FRIDAY ESPECIALLY NORTHERN AREAS...WHILE SOUTHERN AREAS NEAR/SOUTH OF THE OHIO HAVE A BETTER SHOT AT SEEING SUN. COULD BE FLURRIES OUT OF ANY OF THE LOWER CLOUDS CEILINGS THURSDAY NIGHT/FRIDAY...BUT MOISTURE DEPTH IS SUSPECT RIGHT NOW SO WILL LEAVE OUT OF THE FORECAST FOR RIGHT NOW. BUT DID TOY HEAVILY WITH PUTTING LONG DURATION FLURRY MENTION FROM THURSDAY INTO FRIDAY IN THE NORTHERN FORECAST AREA. WITH HIGH PRESSURE/ANTICYCLONIC LOW LEVEL FLOW APPROACHING FRI NIGHT THINK THE CHANCES FOR A LITTLE BETTER CLEARING WILL PRESENT. IF CLEARING IS WIDESPREAD...LIGHT WINDS AND VERY CHILLY AIRMASS WOULD COMBINE FOR COLD OVERNIGHT LOWS IN THE TEENS AND LOWER 20S. TRIED TO SHIFT TO A BIAS-CORRECTION BLEND IN THIS PERIOD TO BRING OUT COLD PRONE AREAS A LITTLE BETTER IN THE FRI NIGHT MIN TEMP FORECAST. RECORDS STILL SEEM SAFE THROUGH FRIDAY NIGHT. THE ONE POSSIBLE EXCEPTION TO THIS IS THE RECORD FOR LOW MAXIMUM TEMPERATURES ON FRIDAY AFTERNOON IF LOW CLOUDS REMAIN IN PLACE FOR SOME OF THE AREA. FORECAST VALUES ARE CLOSE TO THE 1916 RECORDS AT ALL THREE CLIMATE SITES: DAY...31 CVG...32 CMH...34 && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... COUPLE OF CONCERNS IN THIS PERIOD...THE FIRST BEING A TREND IN THE 12.00Z GFS/ECMWF GUIDANCE OF SLOWER DIG SOUTH AND NORTHEAST EJECTION OF ENERGY MOVING INTO THE WRN CONUS ON THE DOWNSTREAM PORTION OF THE ANOMALOUS WRN RIDGE. WHAT HAD BEEN A FASTER/SUPPRESSED SOLUTION /CARRYING ANY MEANINGFUL THREAT OF MEASURABLE PRECIPITATION SOUTH/EAST OF THE AREA SUNDAY/ HAS NOW SLOWED SOMEWHAT WITH MORE WWRD DIGGING BEFORE EJECTION THRU THE TN/OHIO VALLEYS. THE RESULT IS NOW A DEPICTION THAT PERHAPS THE SRN FORECAST AREA MAY BE AFFECTED BY A DEFORMATION BAND OF LIGHT PRECIPITATION NEAR CRITICAL THRESHOLDS FOR RAIN AND/OR SNOW ON SUN/SUN NIGHT. FIRST REAL HINT OF THIS SO DON/T WANT TO JUMP TOO MUCH TOWARD IT...BUT DID LINGER PRECIP THREATS LONGER INTO SUNDAY NIGHT TO ACKNOWLEDGE IT. MAY NEED STRONGER INCREASES IN PRECIP CHANCES AND PERHAPS A RAIN/SNOW MIX MENTION GIVEN CRITICAL WARM LAYERS NOW ENCROACHING THE SRN CWA WITH THE SLIGHTLY FURTHER NORTH EJECTION. SECOND CONCERN IS COLD PLUNGE IN THE WAKE OF THIS WAVE FOR MON/TUES. SEEMS TO BE STRONGER SIGNAL IN DETERMINISTIC /12.00Z ECMWF/ AND ENSEMBLE /NAEFS..ECMWF/ THAT RATHER ANOMALOUS 850MB TEMP MINIMUM BETWEEN -15C AND -20C WILL CROSS THE OHIO VALLEY MON/TUES. NAEFS CLIMATOLOGICAL PERCENTILES OF THE MODEL FORECAST WITH RESPECT TO 30-YEAR CSFR CLIMO /1979-2009/ SUGGESTS THIS TEMP ANOMALY IS NEAR OR JUST INSIDE THE CLIMO ENVELOPE /1%-ILE/. INDEED...THE GEFS STANDARDIZED ANOMALIES ARE ALREADY 2.5 SIGMA BELOW CLIMO...WHICH IS CONSIDERABLE CONSIDERING AN ENSEMBLE MEAN AT THIS TIME RANGE. IF THIS WERE TO VERIFY...PROBABLY WOULD NEED A HEALTHY REDUCTION IN MONDAY NIGHT MIN TEMPS...TUES MAX TEMPS...AND TUES NIGHT MIN TEMPS. RECORDS ARE VERY COLD IN THIS TIME PERIOD /NOV 19TH RECORDS SET DURING BRUTAL 1880 NOVEMBER STRETCH/ BUT NOV 18TH RECORDS COULD BE THREATENED IF THIS PLAYS OUT LIKE 12.00Z ECMWF AND 11.12Z ECMWF ENSEMBLE SUGGEST IT COULD. IT IS ALSO NOTED THAT GEFS 500MB HEIGHT ANOMALIES ARE SUGGESTED TO BE > 3 SIGMA BELOW CLIMO...BUT WITH A GREAT DEAL OF SPREAD...SO WE NEED TO KEEP AN EYE ON THIS TIME PERIOD...INCLUDING THE LEADING WAVE SUNDAY/SUNDAY NIGHT TALKED ABOUT INT HE FIRST PARAGRAPH. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... AN UPPER LEVEL TROUGH WILL SLOWLY DIG SOUTHEAST INTO THE GREAT LAKES AND OHIO VALLEY THROUGH THE TAF PERIOD. MAIN FORECAST CONCERN FOR THIS PACKAGE IS WHETHER CURRENT MVFR STRATOCUMULUS CLOUDS WILL BREAK/ERODE WITH TIME. PIREPS INDICATE THAT THE CLOUD LAYER IS ABOUT 1000-1500 FEET THICK NEAR THE 900 MB LEVEL (ROUGHLY 2500 AGL)...SO ITS FAIRLY THIN. LATEST VISIBLE IMAGERY IS STARTING TO SHOW SOME THIN SPOTS DEVELOPING. DESPITE THIS INFORMATION...IT IS STILL UNCLEAR IF THE CLOUD DECK WILL TOTALLY GO AWAY. AS SUCH...HAVE GONE WITH MVFR CEILINGS THROUGH MOST OF THE TAF PERIOD. THIS WILL ALLOW SATELLITE AND OBSERVATIONAL TRENDS DICTATE IF THE CLOUDS SHOW SIGNS OF EROSION/SCOURING. BY LATE IN THE TAF PERIOD...ENOUGH DAYTIME HEATING IN A CONTINUE CAA PATTERN SHOULD ALLOW CEILINGS TO LIFT TO THE VFR LEVEL. ANY WEATHER ASSOCIATED WITH THE UPPER TROUGH WILL BE MAINLY IN THE FORM OF LAKE EFFECT SNOW AND SHOULD NOT AFFECT THE TERMINALS. OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES POSSIBLE SUNDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...BINAU NEAR TERM...BINAU/HICKMAN SHORT TERM...BINAU LONG TERM...BINAU AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
958 AM EST WED NOV 12 2014 .SYNOPSIS... A PROLONGED PERIOD OF BELOW NORMAL TEMPERATURES WILL COMMENCE TODAY AND CONTINUE THROUGHOUT MUCH OF NEXT WEEK AS A LARGE POOL OF UNSEASONABLY COLD AIR OVER THE EASTERN TWO THIRDS OF THE UNITED STATES BECOMES ENTRENCHED. IT WILL LARGELY BE A DRY PATTERN FOR THE OHIO VALLEY...THOUGH A WEATHER SYSTEM SHIFTING THROUGH ON SUNDAY AND SUNDAY NIGHT WILL BRING THE THREAT OF SOME SNOW TO THE AREA...PERHAPS MIXING WITH OR CHANGING TO RAIN ACROSS KENTUCKY AND SOUTHEAST OHIO. WITHIN THE LONGER DURATION PERIOD OF BELOW NORMAL TEMPERATURES...WILL BE TWO PERIODS WHEN IT WILL BE PARTICULARLY CHILLY. THESE TWO PERIODS WILL BE THURSDAY AND FRIDAY OF THIS WEEK...WITH HIGHS IN THE LOWER AND MIDDLE 30S...AND MONDAY AND TUESDAY OF NEXT WITH SIMILAR OR EVEN SLIGHTLY COLDER HIGHS WHICH MAY NOT ESCAPE THE 20S FOR SOME PARTS OF THE AREA. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LATEST VIS IMAGERY ACROSS THE REGION DEPICTED AN EXPANSIVE AREA OF STRATOCUMULUS CLOUDS EXTENDING FROM THE SOUTHERN GREAT LAKES SOUTHWARD TO THE TN RIVER VALLEY AND THEN WESTWARD TOWARD THE MID MS VALLEY. THE 12.12Z KILN SOUNDING SHOWS THAT THIS CLOUD DECK IS NEAR THE 900 MB LEVEL. THE MOISTURE IS ALSO TRAPPED UNDER A STRONG SUBSIDENCE INVERSION. THE FORECAST DILEMMA FOR TODAY WILL BE WHETHER THE STRATOCUMULUS CLOUDS PERSISTENT OVER THE REGION OR WHETHER THEY SCOUR/ERODE. THE MOISTURE NEAR 900 MB IS FAIRLY THIN (925 MB-875 MB LAYER). SOME PIREPS RECEIVED FROM THIS MORNING ALSO INDICATE THAT THIS DECK IS ABOUT 1000 FEET THICK. THIS IS A PLUS FOR WANTING THE CLOUDS TO ERODE WITH SOME DIURNAL HEATING WORKING IN TANDEM WITH WEAK ANTICYCLONIC FLOW IN THE LOW LEVELS. THIS SCENARIO IS BEING FORECAST BY THE LATEST RAP MODEL EITHER THROUGH POINT SOUNDINGS OR FORECAST CEILING HEIGHTS. ON THE OTHER HAND...THE MODEL COULD JUST BE A BIT AMBITIOUS AND THE CLOUDS COULD END UP LINGERING ALL DAY. THUS...HAVE TAKEN A BLEND AT THIS POINT WHICH IS TO ALLOW SKIES TO BECOME PARTLY CLOUDY BY LATE AFTN/EARLY EVENING AND WILL MONITOR CLOUD TRENDS . FORECAST HIGHS IN THE UPPER 30S TO THE LOWER 40S LOOK GOOD AT THIS POINT. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... TONIGHT...UPSTREAM SHORTWAVE TROUGH OVER SD/MN WILL ROTATE SOUTHEAST INTO MI/IL AS THE PRIMARY WAVE THAT PASSED THROUGH THE AREA TUESDAY NIGHT CONTINUES TO EJECT NORTHEAST INTO AREAS EAST OF HUDSON BAY. THERE IS SOME MID/UPPER LEVEL FORCING WITH THE APPROACHING WAVE LATER TONIGHT...AND THIS FORCING CROSSES MAINLY CNTL/WRN OH DURING THE MORNING HOURS ON THURSDAY. THIS SHOWN NICELY IN 90KM Q-VECTORS CONVERGENCE MAXIMA ROTATING ACROSS THE NRN FORECAST AREA LATE TONIGHT INTO EARLY THURSDAY AFTN COINCIDENT WITH WEAK MID LEVEL VERTICAL MOTION. SHOULD BE A HEALTHY MID DECK OF CLOUDS WITH THIS FORCING...OUT OF WHICH A FEW FLURRIES OR PATCHES OF LIGHT SNOW COULD FIND THEIR WAY TO THE SURFACE OVER CNTL OHIO...BUT DRY SUB-CLOUD LAYERS SHOULD MITIGATE THE NEED FOR A MEASURABLE POP. JUST NOT SEEING ANY SUFFICIENT LOWER LEVEL FORCING OR MOISTURE TO WORK WITH THIS WAVE. THE PASSING OF THIS WAVE WILL ALLOW A BETTER FLOW OF COLDER AIR INTO THE FORECAST AREA THURSDAY NIGHT INTO FRIDAY. IN FACT...BY SUNRISE ON FRIDAY 850MB TEMPS WILL HAVE FALLEN TO -12C TO -15C ACROSS THE AREA WHICH IS AROUND 2 SIGMA BELOW CLIMO FOR NRN KY/SRN OHIO. KEPT HIGH TEMPERATURES RIGHT WHERE THEY WERE FOR BOTH THURSDAY AND FRIDAY. PRETTY CHILLY BOTH DAYS WITH HIGHS IN THE LOWER/MID 30S. WHILE TOTAL TROPOSPHERIC MOISTURE WILL DECREASE AS THE WAVE PASSES THURSDAY MORNING INTO EARLY THURSDAY AFTERNOON...STILL THINK LOW CLOUDS WILL BE PESKY DUE TO RE-STEEPENING OF THE LAPSE RATES WITH THE COLDER AIR FLOWING IN AND A MORE CYCLONIC FLOW. 12.00Z FCST SOUNDINGS FROM NAM/GFS STILL HINTING THAT LOW CLOUDS COULD HANG INTO FRIDAY ESPECIALLY NORTHERN AREAS...WHILE SOUTHERN AREAS NEAR/SOUTH OF THE OHIO HAVE A BETTER SHOT AT SEEING SUN. COULD BE FLURRIES OUT OF ANY OF THE LOWER CLOUDS CEILINGS THURSDAY NIGHT/FRIDAY...BUT MOISTURE DEPTH IS SUSPECT RIGHT NOW SO WILL LEAVE OUT OF THE FORECAST FOR RIGHT NOW. BUT DID TOY HEAVILY WITH PUTTING LONG DURATION FLURRY MENTION FROM THURSDAY INTO FRIDAY IN THE NORTHERN FORECAST AREA. WITH HIGH PRESSURE/ANTICYCLONIC LOW LEVEL FLOW APPROACHING FRI NIGHT THINK THE CHANCES FOR A LITTLE BETTER CLEARING WILL PRESENT. IF CLEARING IS WIDESPREAD...LIGHT WINDS AND VERY CHILLY AIRMASS WOULD COMBINE FOR COLD OVERNIGHT LOWS IN THE TEENS AND LOWER 20S. TRIED TO SHIFT TO A BIAS-CORRECTION BLEND IN THIS PERIOD TO BRING OUT COLD PRONE AREAS A LITTLE BETTER IN THE FRI NIGHT MIN TEMP FORECAST. RECORDS STILL SEEM SAFE THROUGH FRIDAY NIGHT. THE ONE POSSIBLE EXCEPTION TO THIS IS THE RECORD FOR LOW MAXIMUM TEMPERATURES ON FRIDAY AFTERNOON IF LOW CLOUDS REMAIN IN PLACE FOR SOME OF THE AREA. FORECAST VALUES ARE CLOSE TO THE 1916 RECORDS AT ALL THREE CLIMATE SITES: DAY...31 CVG...32 CMH...34 && .LONG TERM /SATURDAY THROUGH TUESDAY/... COUPLE OF CONCERNS IN THIS PERIOD...THE FIRST BEING A TREND IN THE 12.00Z GFS/ECMWF GUIDANCE OF SLOWER DIG SOUTH AND NORTHEAST EJECTION OF ENERGY MOVING INTO THE WRN CONUS ON THE DOWNSTREAM PORTION OF THE ANOMALOUS WRN RIDGE. WHAT HAD BEEN A FASTER/SUPPRESSED SOLUTION /CARRYING ANY MEANINGFUL THREAT OF MEASURABLE PRECIPITATION SOUTH/EAST OF THE AREA SUNDAY/ HAS NOW SLOWED SOMEWHAT WITH MORE WWRD DIGGING BEFORE EJECTION THRU THE TN/OHIO VALLEYS. THE RESULT IS NOW A DEPICTION THAT PERHAPS THE SRN FORECAST AREA MAY BE AFFECTED BY A DEFORMATION BAND OF LIGHT PRECIPITATION NEAR CRITICAL THRESHOLDS FOR RAIN AND/OR SNOW ON SUN/SUN NIGHT. FIRST REAL HINT OF THIS SO DON/T WANT TO JUMP TOO MUCH TOWARD IT...BUT DID LINGER PRECIP THREATS LONGER INTO SUNDAY NIGHT TO ACKNOWLEDGE IT. MAY NEED STRONGER INCREASES IN PRECIP CHANCES AND PERHAPS A RAIN/SNOW MIX MENTION GIVEN CRITICAL WARM LAYERS NOW ENCROACHING THE SRN CWA WITH THE SLIGHTLY FURTHER NORTH EJECTION. SECOND CONCERN IS COLD PLUNGE IN THE WAKE OF THIS WAVE FOR MON/TUES. SEEMS TO BE STRONGER SIGNAL IN DETERMINISTIC /12.00Z ECMWF/ AND ENSEMBLE /NAEFS..ECMWF/ THAT RATHER ANOMALOUS 850MB TEMP MINIMUM BETWEEN -15C AND -20C WILL CROSS THE OHIO VALLEY MON/TUES. NAEFS CLIMATOLOGICAL PERCENTILES OF THE MODEL FORECAST WITH RESPECT TO 30-YEAR CSFR CLIMO /1979-2009/ SUGGESTS THIS TEMP ANOMALY IS NEAR OR JUST INSIDE THE CLIMO ENVELOPE /1%-ILE/. INDEED...THE GEFS STANDARDIZED ANOMALIES ARE ALREADY 2.5 SIGMA BELOW CLIMO...WHICH IS CONSIDERABLE CONSIDERING AN ENSEMBLE MEAN AT THIS TIME RANGE. IF THIS WERE TO VERIFY...PROBABLY WOULD NEED A HEALTHY REDUCTION IN MONDAY NIGHT MIN TEMPS...TUES MAX TEMPS...AND TUES NIGHT MIN TEMPS. RECORDS ARE VERY COLD IN THIS TIME PERIOD /NOV 19TH RECORDS SET DURING BRUTAL 1880 NOVEMBER STRETCH/ BUT NOV 18TH RECORDS COULD BE THREATENED IF THIS PLAYS OUT LIKE 12.00Z ECMWF AND 11.12Z ECMWF ENSEMBLE SUGGEST IT COULD. IT IS ALSO NOTED THAT GEFS 500MB HEIGHT ANOMALIES ARE SUGGESTED TO BE > 3 SIGMA BELOW CLIMO...BUT WITH A GREAT DEAL OF SPREAD...SO WE NEED TO KEEP AN EYE ON THIS TIME PERIOD...INCLUDING THE LEADING WAVE SUNDAY/SUNDAY NIGHT TALKED ABOUT INT HE FIRST PARAGRAPH. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... MVFR CLOUDS ARE HANGING IN ACROSS MUCH OF THE REGION THIS MORNING. IN A CONTINUED LOW LEVEL CAA PATTERN...WILL TREND THE TAFS PESSIMISTIC AND KEEP THE MVFR CIGS INTO THIS AFTERNOON. WILL THEN ALLOW FOR THEM TO SCATTER OUT AND/OR LIFT INTO VFR CIGS THROUGH MID TO LATE AFTERNOON. SURFACE HIGH PRESSURE WILL TRY TO NOSE INTO THE AREA FROM THE WEST THROUGH TONIGHT AND THIS SHOULD ALLOW FOR VFR CONDITIONS THROUGH THE REMAINDER OF THE TAF PERIOD. OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES POSSIBLE SUNDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...BINAU NEAR TERM...BINAU/HICKMAN SHORT TERM...BINAU LONG TERM...BINAU AVIATION...JGL
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
853 AM EST WED NOV 12 2014 .SYNOPSIS... SIGNIFICANT AIRMASS CHANGE FOR THE NEXT FEW DAYS. HIGH PRESSURE THURSDAY THROUGH SATURDAY. NEXT SYSTEM WITH DEEPER MOISTURE SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... 850 AM UPDATE...NO MAJOR CHANGES NEEDED. PREVIOUS DISCUSSION... MODELS FINALLY BRING IN THE FIRST STAGE OF PROGRESSIVELY COLDER AIR TODAY AND TONIGHT AS EXPANSIVE CANADIAN HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST. MODELS QUICKLY END THE SCATTERED SHOWERS FROM WEST TO EAST THIS MORNING AS DRIER AIR MOVES IN ALOFT. HOWEVER...THIS FIRST SURGE IS NOT NEARLY COLD ENOUGH TO CHANGE SCATTERED MORNING RAIN SHOWERS TO SNOW BEFORE ENDING. MODELS ALSO SHOW SOME MODEST RECOVERY IN TEMPERATURES TODAY SA THE REAL COLD AIR WILL BE DELAYED SOMEWHAT...BUT HIGHS TODAY WILL REMAIN IN THE 40S. THE MAIN QUESTION THIS PERIOD IS WHETHER OR HOW MUCH THE WIDESPREAD POST FRONTAL STRATUS WILL BREAK THIS AFTERNOON...WHICH IN TURN WILL HELP DETERMINE JUST WHERE HIGH TEMPERATURES OCCUR IN THE 40S. HERE THERE ARE TWO CAMPS. THE NAM APPEARS TO BE THE OUTLIER IN HOLDING THE CLOUDS TODAY AND KEEPING HIGHS MOSTLY IN THE LOWER 40S. THE GFS AND RAP LOOK TO DISSIPATE THE CLOUDS THIS AFTERNOON AND PUSH TEMPS WITH SOME SUNSHINE INTO THE MID AMD UPPER 40S. HAVE TO GO WITH THE MODEL CONSENSUS OF BREAKING THE CLOUDS FROM WEST TO EAST THIS AFTERNOON...AND GO ON THE HIGHER TEMPERATURES SIDE OF THE MAV GUIDANCE. THIS IS REINFORCED BY EVEN THE NAM COMING VERY CLOSE IN WEAKENING THE LOW LEVEL INVERSION AND MIXING OUT THE LOWER LEVEL MOISTURE. WILL LEAN HEAVILY TO THE GFS FOR DETAILS TODAY. FOR TONIGHT...WOULD EXPECT THE LOW LEVEL INVERSION TO STRENGTHEN AGAIN AND HELP REFORM CLOUDS WITH THE LINGERING LOW LEVEL MOISTURE BELOW THIS INVERSION. SO WHILE LEANING BACK TOWARD THE NAM TO BECOME MOSTLY CLOUDY TONIGHT...THE NAM DOES APPEARS TOO COOL IN THE MOUNTAINS. WILL BLEND MOS GUIDANCE FOR TEMPS TONIGHT...WHICH STILL BRINGS MINS DOWN INTO THE UPPER 20S. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... WELL ADVERTISED COLD AIRMASS WILL BE FULLY ENTRENCHED IN THE MIDDLE OHIO VALLEY AND CENTRAL APPALACHIANS THURSDAY AND PERSISTING THROUGH THE DURATION OF THE SHORT TERM FORECAST. OVERALL...CHANGES TO THE FORECAST HAVE BEEN MINIMAL...WITH STRONG HIGH PRESSURE INFLUENCES FROM THE CENTRAL PLAINS AREA. FOR THIS FORECAST PACKAGE...STILL CHASING THE LOW LEVEL MOISTURE AND STREAMLINES FOR THE LOW END CHANCES FOR SNOW SHOWERS IN THE MOUNTAINS. OTHERWISE...MODELS HAVE SHOWN GOOD CONSISTENCY FROM RUN TO RUN FROM TIMING TO LOW LEVEL AIR TEMPERATURES. KEEPING ON THE LOWER SIDE OF GUIDANCE FOR THURSDAY AND FRIDAY...AND DO NOT SEE THE LOWLANDS GETTING OUT OF THE 30S. A LITTLE RECOVERY BRINGS TEMPERATURES INTO THE LOWER 40S FOR SATURDAY AS THE AIRMASS BEGINS TO MODIFY. BY THIS TIME...THE CENTER OF HIGH PRESSURE WILL STILL BE TO THE WEST OVER THE LOWER OHIO VALLEY. THE NEXT FRONTAL SYSTEM BEGINS TO ORGANIZE OVER THE CENTRAL AND SOUTHERN PLAINS BY 00Z SUNDAY. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... NO MAJOR CHANGES FROM OUR THINKING YESTERDAY. WILL HOLD ONTO SOME LINGERING FLURRIES INTO FRIDAY EVENING AS THE MOISTURE BELOW 850 MB CONTINUES TO THIN. STILL DRY ON SATURDAY WITH SUNSHINE FIGURED. HIGH PRESSURE SHIFTS TO OUR EAST SATURDAY EVENING...WILL GO A BIT COLDER CKB TO EKN VCNTY THAN WPC MEDIUM RANGE GUIDANCE...SINCE THE EVENING SHOULD START OUT MOSTLY CLEAR. STRONG WARM AIR ADVECTION IN THE LOWER MISSISSIPPI VALLEY SATURDAY EVENING BECOMES WEAKER AS IT SHIFTS NORTHEAST OVERNIGHT SATURDAY NIGHT. THEN A STRENGTHENING 250 MB JET DEVELOPS BY 12Z SUNDAY BUT SHIFTS EAST OF US BY 00Z MONDAY. SO THINKING DEEPER MOISTURE WILL ADVECT OUR WAY OVERNIGHT SATURDAY NIGHT...WITH SOME LIGHT SNOW POSSIBLE 06Z TO 12Z SUNDAY. WILL LEAVE THE RAIN OR SNOW OPTION FOR THE AFTERNOON. 12Z ECWMF CERTAINLY MILDER ON 850 MB TEMPERATURES AT 18Z SUNDAY THAN 12Z GFS. AS THE STRONGER JET DYNAMICS SHIFT TO THE MID ATLANTIC COAST SUNDAY EVENING...HAVE PRECIPITATION CHANGING TO SNOW SHOWERS AS LOW LEVEL COLD AIR ADVECTION BEGINS AGAIN. AS OF NOW...HAVE MINOR SNOW ACCUMULATIONS LATE SATURDAY NIGHT THROUGH SUNDAY NIGHT...SO STILL DO NOT SEE NEED TO INCLUDE ANY HAZARDS IN HAZARDOUS WEATHER POTENTIAL CURRENTLY. THE COLDER AIR ON MONDAY SHOULD QUICKLY DRY OUT. YET...AT THIS DISTANCE WILL STILL LEAVE SOME CHANCE POPS FOR SNOW SHOWERS OVER THE WEST VIRGINIA MOUNTAIN COUNTIES MONDAY MORNING. DRY/COLD/TRANQUIL FIGURED FOR MONDAY NIGHT INTO TUESDAY. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... 12Z WEDNESDAY THRU 12Z THURSDAY... COLD FRONT WILL EXIT MOUNTAINS BY 12Z WITH GENERAL MVFR CEILINGS FOLLOWING THE FRONT. CIGS MAY DIP TO IFR MAINLY IN THE MOUNTAINS UNTIL 15Z. A BAND OF MAINLY MOUNTAIN SHOWERS WILL END BY 14Z. THE BIG QUESTION IS WHAT HAPPENS TO THE STRATUS TODAY. RELATIVELY WEAK COLD ADVECTION AND SOME MIXING WITH DRIER AIR AT THE TOP OF A LOW LEVEL INVERSION...IS EXPECTED TO BREAK UP THE CLOUDS FROM WEST TO EAST LATER IN THE AFTERNOON. THUS...GENERAL MVFR CEILINGS LOWLANDS WILL SCATTER OUT BY 22Z...WHILE MVFR/IFR CEILINGS MOUNTAINS WILL ALSO SCATTER AROUND 00Z. FOR TONIGHT...WITH LOW LEVEL MOISTURE...WEAK COLD ADVECTION...AND LOW LEVEL INVERSION INTACT...EXPECT STRATUS CLOUD DECK TO REDEVELOP. AFTER 04Z...LOOK FOR VFR CEILINGS FROM OHIO RIVER WESTWARD...MVFR CEILINGS IN REMAINDER OF LOWLANDS UP TO THE MOUNTAINS...AND MVFR/IFR CEILINGS MOUNTAINS. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY... FORECAST CONFIDENCE: LOW ALTERNATE SCENARIOS: DISSIPATION AND REDEVELOPMENT OF STRATUS THIS PERIOD GREATLY DEPENDS ON HOW MUCH DRY AIR WE CAN MIX DOWN THIS AFTERNOON...AND HOW STRONG THE LOW LEVEL INVERSION IS TONIGHT. 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 EST 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20 CRW CONSISTENCY H H H H H M M M H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY M H H H M M M M M M M M EKN CONSISTENCY M H H M M M M M M M M M PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H M M M M H H H H AFTER 12Z THURSDAY... IFR CONDITIONS POSSIBLE IN THE MOUNTAINS THRU 12Z THURSDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...JMV/26 NEAR TERM...JMV/SL SHORT TERM...26 LONG TERM...KTB AVIATION...JMV
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
736 AM EST WED NOV 12 2014 .SYNOPSIS... LOW PRESSURE...NOW MOVING INTO QUEBEC...WILL CONTINUE NORTHEAST. BEHIND IT MUCH COLDER AIR WILL SPREAD ACROSS THE OHIO VALLEY AND LOWER GREAT LAKES REGION. HIGH PRESSURE WILL BUILD EAST OVER THE AREA BY SATURDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATE...INCREASED CLOUD COVER THROUGH THE AFTERNOON. ALSO ADJUSTED HOURLY TEMPS ORIGINAL...COLD FRONT IS NOW WELL EAST OF THE AREA WITH WNW WINDS AND FALLING TEMPS ACROSS THE REGION. RADAR SHOWS THE SWATH OF RAIN ASSOCIATED WITH THE FRONT HAS ALL BUT EXITED THE AREA WITH A FEW RETURNS STILL IN THE EXTREME EAST. WILL HOLD ONTO SLIGHT CHANCE POPS EAST INITIALLY FOR DRIZZLE OR LIGHT RAIN OF SNOW SHOWERS. AFTER DAWN WILL HAVE A SLIGHT CHANCE POP FOR LIGHT RAIN OF SNOW SHOWERS MAINLY IN THE TRADITIONAL LAKE EFFECT AREAS AS NWLY FLOW BRINGS -6 TO -8C AIR ACROSS THE LAKE. FOR THE AFTERNOON WHEN 850MB TEMPS DROP TO -6 TO -8C WILL INCREASE POPS TO CHANCE. AWAY FROM THE LAKE DRY CONDITIONS SHOULD DOMINATE. COULD SEE CLOUDS BEGIN TO BREAK THIS AFTERNOON AS DRIER AIR MOVES IN. FOLLOWING THE HRRR WE SHOULD WARM A BIT TODAY BUT ON BALANCE DO NOT BELIEVE WE WILL SEE AFTERNOON HIGHS REACH MAV NUMBERS SO HAVE CUT 2 TO 3 DEGREES FROM GUIDANCE TO FAVOR MID AND UPPER 30S VS NEAR 40 MOST AREAS. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... AIRMASS STARTS OUT FAIRLY DRY ACROSS THE AREA THIS EVENING. 850MB TEMPS SHOULD BE AROUND -9C TO -10C OVER THE LAKE AND NRN COUNTIES. EVEN WITH THE DRY AIR WOULD EXPECT SNOW SHOWERS OFF THE LAKE BUT ELSEWHERE DRY. OVERNIGHT AN UPPER TROUGH DROPS SOUTHEAST ACROSS THE CENTRAL LAKES ENHANCING LOW LEVEL LIFT FRONT THE LAKE INTO THE SNOWBELT. THE NAM AND SREF ALSO SHOW THE AIRMASS BEGINNING TO MOISTEN ESP ACROSS NERN OHIO AND NWRN PA. WILL BEGIN WITH CHANCE POPS THIS EVENING BUT OVERNIGHT WILL INCREASE TO LIKELY AS CONDITIONS BECOME INCREASINGLY MORE FAVORABLE. ACCUMS LIKELY IN THE 1-2 INCH RANGE FROM LAKE AND NRN ASHTABULA COUNTIES EAST INTO NWRN PA. THURSDAY MODELS SHOW FURTHER MOISTENING WITH THE MOIST LAYER ENCOMPASSING THE FAVORABLE TEMPERATURE RANGE FOR DENDRITIC SNOW GROWTH. STILL...SYNOPTIC LIFT IS WEAK. GIVEN THE ADDED FAVORABLE PARAMETERS WILL CONTINUE LIKELY POPS THROUGH THE MORNING INCREASING TO CATEGORICAL FROM AROUND NOON ON AS LAKE/850MB TEMPS DIFFERENCE RESULTS IN EXTREME INSTABILITY. ACCUMS AT THIS POINT 2 TO 4. THURSDAY EVENING AND NIGHT THE UPPER TROUGH AXIS DROP ACROSS THE AREA. INSTABILITY REMAINS EXTREME AND INVERSION WILL HAVE LIFTED TO CLOSE TO 725MB. BUFKIT ALSO SHOWS SYNOPTIC LIFT ACROSS THE AREA. WITH WINDS VEERING 20-30 DEGREES BELIEVE SNOW WILL REACH FURTHER INLAND AND POSSIBLY BE LESS BANDED SO ADJUSTED LIKELY AND CATEGORICAL AREAS TO REFLECT THIS. HAVE AROUND 3 INCHES IN GRAPHICS. LITTLE CHANGE FOR FRIDAY HOWEVER SNOW SHOULD BE TAPERING AFTERNOON AND EVENING AS THE ARCTIC SURFACE HIGH BUILDS IN FROM THE WEST. WILL HANG ONTO A LOW CHANCE POP FOR LAKE EFFECT SATURDAY. TEMPS REMAIN BELOW NORMAL...MAINLY IN THE 30S FOR HIGHS. && .LONG TERM /SUNDAY THROUGH TUESDAY/... VERY COLD STRETCH OF WEATHER FOR MID-NOVEMBER WILL CONTINUE THROUGH THE EXTENDED FORECAST. THE UPPER LEVEL TROUGH DEEPENS WEST OF THE GREAT LAKES ON SUNDAY AND SUNDAY NIGHT AS A STRONG VORT MAX DIVES SOUTH FROM THE ARCTIC. WILL CONTINUE TO CARRY A CHANCE OF SNOW IN THE FORECAST FOR ALL AREAS ON SUNDAY WITH WEAK ISENTROPIC ASCENT WITHIN THE SOUTHWESTERLY FLOW AHEAD OF THE TROUGH. QPF SHOULD BE LIGHT WITH ONLY A FEW HUNDREDTHS EXPECTED. WE WILL WANT TO KEEP AN EYE ON A WAVE OF LOW PRESSURE TRACKING NORTHEAST FROM THE GULF COAST UP THE APPALACHIANS ON MONDAY. THE ECMWF HAS BEEN TRENDING TOWARDS A A DEEPER AND MORE WESTWARD ADJUSTMENT TO THE UPPER LEVEL TROUGH WHICH COULD RESULT IN THIS LOW BEING PULLED A LITTLE FARTHER NORTH INTO THE OHIO VALLEY. IF THIS IS THE CASE...WE COULD END UP NEEDING HIGHER POPS...BUT COULD ALSO PULL ENOUGH WARM AIR INTO THE SYSTEM TO HAVE PRECIP TYPE ISSUES. FOR NOW WILL KEEP THE FORECAST AS ALL SNOW AND MONITOR MODEL TRENDS. HIGH TEMPERATURES ON MONDAY AND TUESDAY COULD BE AS MUCH AS 20 DEGREES BELOW NORMAL IN THE UPPER 20S TO NEAR 30 DEGREES. MODELS HAVE BEEN FAIRLY CONSISTENT ON BRINGING THIS EVEN COLDER SURGE OF AIR DOWN WITH 850MB TEMPS DROPPING TO AT LEAST -14C. LAKE EFFECT SNOW WILL LIKELY FLARE UP ON MONDAY NIGHT AND TUESDAY AS THE UPPER TROUGH SWINGS THROUGH. THIS COULD BE ANOTHER GOOD SET-UP FOR ACCUMULATING LAKE EFFECT SNOW IN THE SNOWBELT REGION. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... CEILINGS RANGE FROM 2200-3500 FEET ACROSS THE AREA THIS MORNING BEHIND A COLD FRONT. CEILINGS WILL GRADUALLY LIFT TO NEAR OR ABOVE 3000 FEET THIS AFTERNOON AND START TO SCATTER OUT FROM WEST TO EAST ACROSS NRN OHIO FOR A FEW FEW HOURS THIS EVENING...BUT ARE EXPECTED TO FILL BACK IN OVERNIGHT. THERE WILL BE A LOW CHANCE OF SNOW SHOWERS AT ERI TODAY BUT WILL INCREASE AFTER 07Z AS LAKE EFFECT SNOW RAMPS UP. WESTERLY WINDS WILL REMAIN GUSTY AT CLE/ERI THROUGH THE AFTERNOON. .OUTLOOK...NON VFR IN SNOW SHOWERS AT ERI AT TIMES ON THURSDAY...INCREASING THURSDAY NIGHT INTO FRIDAY. NON-VFR CEILINGS WILL LINGER THURSDAY AND CONTINUE INTO FRIDAY. NON-VFR LIKELY SUNDAY WITH SNOW SHOWERS WITH THE NEXT FRONT. && .MARINE... SMALL CRAFT ADVISORIES REMAIN IN EFFECT FOR NEARSHORE WATERS IN ALL AREAS THROUGH THIS AFTERNOON...AND THROUGH THURSDAY NIGHT ON THE EAST HALF OF THE LAKE. WESTERLY WINDS WILL START THE DAY IN THE 20-25 KNOT RANGE BEFORE DECREASING TO 15-20 KNOTS BY LATE AFTERNOON. WESTERLY WINDS WILL REMAIN IN THE 15-20 KNOT RANGE THROUGH THURSDAY THEN SHIFT TO NORTHWESTERLY THURSDAY NIGHT. WINDS WILL SLOWLY DECREASE FRIDAY AFTERNOON AND NIGHT AS HIGH PRESSURE BUILDS OVER THE OHIO VALLEY. ANOTHER COLD FRONT IS EXPECTED TO MOVE ACROSS THE LAKE ON SUNDAY NIGHT WITH ANOTHER VERY COLD AIRMASS TO FOLLOW BEHIND. SMALL CRAFT ADVISORIES WILL BE NEEDED AGAIN FOR THE EARLY PART OF NEXT WEEK. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST FRIDAY FOR LEZ146>149. SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LEZ142>145. && $$ SYNOPSIS...TK NEAR TERM...TK SHORT TERM...TK LONG TERM...KEC AVIATION...KEC MARINE...KEC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
648 AM EST WED NOV 12 2014 .SYNOPSIS... LOW PRESSURE...NOW MOVING INTO QUEBEC...WILL CONTINUE NORTHEAST. BEHIND IT MUCH COLDER AIR WILL SPREAD ACROSS THE OHIO VALLEY AND LOWER GREAT LAKES REGION. HIGH PRESSURE WILL BUILD EAST OVER THE AREA BY SATURDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATE...INCREASED CLOUD COVER THROUGH THE AFTERNOON. ALSO ADJUSTED HOURLY TEMPS ORIGINAL...COLD FRONT IS NOW WELL EAST OF THE AREA WITH WNW WINDS AND FALLING TEMPS ACROSS THE REGION. RADAR SHOWS THE SWATH OF RAIN ASSOCIATED WITH THE FRONT HAS ALL BUT EXITED THE AREA WITH A FEW RETURNS STILL IN THE EXTREME EAST. WILL HOLD ONTO SLIGHT CHANCE POPS EAST INITIALLY FOR DRIZZLE OR LIGHT RAIN OF SNOW SHOWERS. AFTER DAWN WILL HAVE A SLIGHT CHANCE POP FOR LIGHT RAIN OF SNOW SHOWERS MAINLY IN THE TRADITIONAL LAKE EFFECT AREAS AS NWLY FLOW BRINGS -6 TO -8C AIR ACROSS THE LAKE. FOR THE AFTERNOON WHEN 850MB TEMPS DROP TO -6 TO -8C WILL INCREASE POPS TO CHANCE. AWAY FROM THE LAKE DRY CONDITIONS SHOULD DOMINATE. COULD SEE CLOUDS BEGIN TO BREAK THIS AFTERNOON AS DRIER AIR MOVES IN. FOLLOWING THE HRRR WE SHOULD WARM A BIT TODAY BUT ON BALANCE DO NOT BELIEVE WE WILL SEE AFTERNOON HIGHS REACH MAV NUMBERS SO HAVE CUT 2 TO 3 DEGREES FROM GUIDANCE TO FAVOR MID AND UPPER 30S VS NEAR 40 MOST AREAS. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... AIRMASS STARTS OUT FAIRLY DRY ACROSS THE AREA THIS EVENING. 850MB TEMPS SHOULD BE AROUND -9C TO -10C OVER THE LAKE AND NRN COUNTIES. EVEN WITH THE DRY AIR WOULD EXPECT SNOW SHOWERS OFF THE LAKE BUT ELSEWHERE DRY. OVERNIGHT AN UPPER TROUGH DROPS SOUTHEAST ACROSS THE CENTRAL LAKES ENHANCING LOW LEVEL LIFT FRONT THE LAKE INTO THE SNOWBELT. THE NAM AND SREF ALSO SHOW THE AIRMASS BEGINNING TO MOISTEN ESP ACROSS NERN OHIO AND NWRN PA. WILL BEGIN WITH CHANCE POPS THIS EVENING BUT OVERNIGHT WILL INCREASE TO LIKELY AS CONDITIONS BECOME INCREASINGLY MORE FAVORABLE. ACCUMS LIKELY IN THE 1-2 INCH RANGE FROM LAKE AND NRN ASHTABULA COUNTIES EAST INTO NWRN PA. THURSDAY MODELS SHOW FURTHER MOISTENING WITH THE MOIST LAYER ENCOMPASSING THE FAVORABLE TEMPERATURE RANGE FOR DENDRITIC SNOW GROWTH. STILL...SYNOPTIC LIFT IS WEAK. GIVEN THE ADDED FAVORABLE PARAMETERS WILL CONTINUE LIKELY POPS THROUGH THE MORNING INCREASING TO CATEGORICAL FROM AROUND NOON ON AS LAKE/850MB TEMPS DIFFERENCE RESULTS IN EXTREME INSTABILITY. ACCUMS AT THIS POINT 2 TO 4. THURSDAY EVENING AND NIGHT THE UPPER TROUGH AXIS DROP ACROSS THE AREA. INSTABILITY REMAINS EXTREME AND INVERSION WILL HAVE LIFTED TO CLOSE TO 725MB. BUFKIT ALSO SHOWS SYNOPTIC LIFT ACROSS THE AREA. WITH WINDS VEERING 20-30 DEGREES BELIEVE SNOW WILL REACH FURTHER INLAND AND POSSIBLY BE LESS BANDED SO ADJUSTED LIKELY AND CATEGORICAL AREAS TO REFLECT THIS. HAVE AROUND 3 INCHES IN GRAPHICS. LITTLE CHANGE FOR FRIDAY HOWEVER SNOW SHOULD BE TAPERING AFTERNOON AND EVENING AS THE ARCTIC SURFACE HIGH BUILDS IN FROM THE WEST. WILL HANG ONTO A LOW CHANCE POP FOR LAKE EFFECT SATURDAY. TEMPS REMAIN BELOW NORMAL...MAINLY IN THE 30S FOR HIGHS. && .LONG TERM /SUNDAY THROUGH TUESDAY/... VERY COLD STRETCH OF WEATHER FOR MID-NOVEMBER WILL CONTINUE THROUGH THE EXTENDED FORECAST. THE UPPER LEVEL TROUGH DEEPENS WEST OF THE GREAT LAKES ON SUNDAY AND SUNDAY NIGHT AS A STRONG VORT MAX DIVES SOUTH FROM THE ARCTIC. WILL CONTINUE TO CARRY A CHANCE OF SNOW IN THE FORECAST FOR ALL AREAS ON SUNDAY WITH WEAK ISENTROPIC ASCENT WITHIN THE SOUTHWESTERLY FLOW AHEAD OF THE TROUGH. QPF SHOULD BE LIGHT WITH ONLY A FEW HUNDREDTHS EXPECTED. WE WILL WANT TO KEEP AN EYE ON A WAVE OF LOW PRESSURE TRACKING NORTHEAST FROM THE GULF COAST UP THE APPALACHIANS ON MONDAY. THE ECMWF HAS BEEN TRENDING TOWARDS A A DEEPER AND MORE WESTWARD ADJUSTMENT TO THE UPPER LEVEL TROUGH WHICH COULD RESULT IN THIS LOW BEING PULLED A LITTLE FARTHER NORTH INTO THE OHIO VALLEY. IF THIS IS THE CASE...WE COULD END UP NEEDING HIGHER POPS...BUT COULD ALSO PULL ENOUGH WARM AIR INTO THE SYSTEM TO HAVE PRECIP TYPE ISSUES. FOR NOW WILL KEEP THE FORECAST AS ALL SNOW AND MONITOR MODEL TRENDS. HIGH TEMPERATURES ON MONDAY AND TUESDAY COULD BE AS MUCH AS 20 DEGREES BELOW NORMAL IN THE UPPER 20S TO NEAR 30 DEGREES. MODELS HAVE BEEN FAIRLY CONSISTENT ON BRINGING THIS EVEN COLDER SURGE OF AIR DOWN WITH 850MB TEMPS DROPPING TO AT LEAST -14C. LAKE EFFECT SNOW WILL LIKELY FLARE UP ON MONDAY NIGHT AND TUESDAY AS THE UPPER TROUGH SWINGS THROUGH. THIS COULD BE ANOTHER GOOD SET-UP FOR ACCUMULATING LAKE EFFECT SNOW IN THE SNOWBELT REGION. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... SWATH OF IFR CEILINGS WILL SLOWLY WORK EAST OVERNIGHT AND CEILINGS WILL LIFT TO MVFR. LIGHT RAIN/DRIZZLE WILL LIKELY LINGER INTO THE PREDAWN HOURS ESPECIALLY IN THE SNOWBELT OF EXTREME NE OH/NW PA. CEILINGS MAY IMPROVE TO VFR AND PERHAPS SCATTER OUT WEDNESDAY AFTERNOON AS SUBSIDENCE INCREASES. GUSTY WEST WINDS WILL SETTLE DOWN BY WEDNESDAY EVENING. .OUTLOOK...NON-VFR IN THE SNOWBELT OF NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA LATE WED NIGHT THROUGH FRIDAY. NON-VFR CEILINGS WILL REDEVELOP ELSEWHERE THURSDAY AND CONTINUE INTO FRIDAY. NON-VFR LIKELY SUNDAY WITH SNOW SHOWERS WITH THE NEXT FRONT. && .MARINE... SMALL CRAFT ADVISORIES REMAIN IN EFFECT FOR NEARSHORE WATERS IN ALL AREAS THROUGH THIS AFTERNOON...AND THROUGH THURSDAY NIGHT ON THE EAST HALF OF THE LAKE. WESTERLY WINDS WILL START THE DAY IN THE 20-25 KNOT RANGE BEFORE DECREASING TO 15-20 KNOTS BY LATE AFTERNOON. WESTERLY WINDS WILL REMAIN IN THE 15-20 KNOT RANGE THROUGH THURSDAY THEN SHIFT TO NORTHWESTERLY THURSDAY NIGHT. WINDS WILL SLOWLY DECREASE FRIDAY AFTERNOON AND NIGHT AS HIGH PRESSURE BUILDS OVER THE OHIO VALLEY. ANOTHER COLD FRONT IS EXPECTED TO MOVE ACROSS THE LAKE ON SUNDAY NIGHT WITH ANOTHER VERY COLD AIRMASS TO FOLLOW BEHIND. SMALL CRAFT ADVISORIES WILL BE NEEDED AGAIN FOR THE EARLY PART OF NEXT WEEK. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST FRIDAY FOR LEZ146>149. SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LEZ142>145. && $$ SYNOPSIS...TK NEAR TERM...TK SHORT TERM...TK LONG TERM...KEC AVIATION...KOSARIK MARINE...KEC
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
538 AM EST WED NOV 12 2014 .SYNOPSIS... SIGNIFICANT AIRMASS CHANGE FOR THE NEXT FEW DAYS. HIGH PRESSURE THURSDAY THROUGH SATURDAY. NEXT SYSTEM WITH DEEPER MOISTURE SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... 545 AM UPDATE. PER RADAR TRENDS...SPED UP END OF SHOWERS A COUPLE OF HOURS. PREVIOUS DISCUSSION... MODELS FINALLY BRING IN THE FIRST STAGE OF PROGRESSIVELY COLDER AIR TODAY AND TONIGHT AS EXPANSIVE CANADIAN HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST. MODELS QUICKLY END THE SCATTERED SHOWERS FROM WEST TO EAST THIS MORNING AS DRIER AIR MOVES IN ALOFT. HOWEVER...THIS FIRST SURGE IS NOT NEARLY COLD ENOUGH TO CHANGE SCATTERED MORNING RAIN SHOWERS TO SNOW BEFORE ENDING. MODELS ALSO SHOW SOME MODEST RECOVERY IN TEMPERATURES TODAY SA THE REAL COLD AIR WILL BE DELAYED SOMEWHAT...BUT HIGHS TODAY WILL REMAIN IN THE 40S. THE MAIN QUESTION THIS PERIOD IS WHETHER OR HOW MUCH THE WIDESPREAD POST FRONTAL STRATUS WILL BREAK THIS AFTERNOON...WHICH IN TURN WILL HELP DETERMINE JUST WHERE HIGH TEMPERATURES OCCUR IN THE 40S. HERE THERE ARE TWO CAMPS. THE NAM APPEARS TO BE THE OUTLIER IN HOLDING THE CLOUDS TODAY AND KEEPING HIGHS MOSTLY IN THE LOWER 40S. THE GFS AND RAP LOOK TO DISSIPATE THE CLOUDS THIS AFTERNOON AND PUSH TEMPS WITH SOME SUNSHINE INTO THE MID AMD UPPER 40S. HAVE TO GO WITH THE MODEL CONSENSUS OF BREAKING THE CLOUDS FROM WEST TO EAST THIS AFTERNOON...AND GO ON THE HIGHER TEMPERATURES SIDE OF THE MAV GUIDANCE. THIS IS REINFORCED BY EVEN THE NAM COMING VERY CLOSE IN WEAKENING THE LOW LEVEL INVERSION AND MIXING OUT THE LOWER LEVEL MOISTURE. WILL LEAN HEAVILY TO THE GFS FOR DETAILS TODAY. FOR TONIGHT...WOULD EXPECT THE LOW LEVEL INVERSION TO STRENGTHEN AGAIN AND HELP REFORM CLOUDS WITH THE LINGERING LOW LEVEL MOISTURE BELOW THIS INVERSION. SO WHILE LEANING BACK TOWARD THE NAM TO BECOME MOSTLY CLOUDY TONIGHT...THE NAM DOES APPEARS TOO COOL IN THE MOUNTAINS. WILL BLEND MOS GUIDANCE FOR TEMPS TONIGHT...WHICH STILL BRINGS MINS DOWN INTO THE UPPER 20S. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... WELL ADVERTISED COLD AIRMASS WILL BE FULLY ENTRENCHED IN THE MIDDLE OHIO VALLEY AND CENTRAL APPALACHIANS THURSDAY AND PERSISTING THROUGH THE DURATION OF THE SHORT TERM FORECAST. OVERALL...CHANGES TO THE FORECAST HAVE BEEN MINIMAL...WITH STRONG HIGH PRESSURE INFLUENCES FROM THE CENTRAL PLAINS AREA. FOR THIS FORECAST PACKAGE...STILL CHASING THE LOW LEVEL MOISTURE AND STREAMLINES FOR THE LOW END CHANCES FOR SNOW SHOWERS IN THE MOUNTAINS. OTHERWISE...MODELS HAVE SHOWN GOOD CONSISTENCY FROM RUN TO RUN FROM TIMING TO LOW LEVEL AIR TEMPERATURES. KEEPING ON THE LOWER SIDE OF GUIDANCE FOR THURSDAY AND FRIDAY...AND DO NOT SEE THE LOWLANDS GETTING OUT OF THE 30S. A LITTLE RECOVERY BRINGS TEMPERATURES INTO THE LOWER 40S FOR SATURDAY AS THE AIRMASS BEGINS TO MODIFY. BY THIS TIME...THE CENTER OF HIGH PRESSURE WILL STILL BE TO THE WEST OVER THE LOWER OHIO VALLEY. THE NEXT FRONTAL SYSTEM BEGINS TO ORGANIZE OVER THE CENTRAL AND SOUTHERN PLAINS BY 00Z SUNDAY. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... NO MAJOR CHANGES FROM OUR THINKING YESTERDAY. WILL HOLD ONTO SOME LINGERING FLURRIES INTO FRIDAY EVENING AS THE MOISTURE BELOW 850 MB CONTINUES TO THIN. STILL DRY ON SATURDAY WITH SUNSHINE FIGURED. HIGH PRESSURE SHIFTS TO OUR EAST SATURDAY EVENING...WILL GO A BIT COLDER CKB TO EKN VCNTY THAN WPC MEDIUM RANGE GUIDANCE...SINCE THE EVENING SHOULD START OUT MOSTLY CLEAR. STRONG WARM AIR ADVECTION IN THE LOWER MISSISSIPPI VALLEY SATURDAY EVENING BECOMES WEAKER AS IT SHIFTS NORTHEAST OVERNIGHT SATURDAY NIGHT. THEN A STRENGTHENING 250 MB JET DEVELOPS BY 12Z SUNDAY BUT SHIFTS EAST OF US BY 00Z MONDAY. SO THINKING DEEPER MOISTURE WILL ADVECT OUR WAY OVERNIGHT SATURDAY NIGHT...WITH SOME LIGHT SNOW POSSIBLE 06Z TO 12Z SUNDAY. WILL LEAVE THE RAIN OR SNOW OPTION FOR THE AFTERNOON. 12Z ECWMF CERTAINLY MILDER ON 850 MB TEMPERATURES AT 18Z SUNDAY THAN 12Z GFS. AS THE STRONGER JET DYNAMICS SHIFT TO THE MID ATLANTIC COAST SUNDAY EVENING...HAVE PRECIPITATION CHANGING TO SNOW SHOWERS AS LOW LEVEL COLD AIR ADVECTION BEGINS AGAIN. AS OF NOW...HAVE MINOR SNOW ACCUMULATIONS LATE SATURDAY NIGHT THROUGH SUNDAY NIGHT...SO STILL DO NOT SEE NEED TO INCLUDE ANY HAZARDS IN HAZARDOUS WEATHER POTENTIAL CURRENTLY. THE COLDER AIR ON MONDAY SHOULD QUICKLY DRY OUT. YET...AT THIS DISTANCE WILL STILL LEAVE SOME CHANCE POPS FOR SNOW SHOWERS OVER THE WEST VIRGINIA MOUNTAIN COUNTIES MONDAY MORNING. DRY/COLD/TRANQUIL FIGURED FOR MONDAY NIGHT INTO TUESDAY. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... 12Z WEDNESDAY THRU 12Z THURSDAY... COLD FRONT WILL EXIT MOUNTAINS BY 12Z WITH GENERAL MVFR CEILINGS FOLLOWING THE FRONT. CIGS MAY DIP TO IFR MAINLY IN THE MOUNTAINS UNTIL 15Z. A BAND OF MAINLY MOUNTAIN SHOWERS WILL END BY 14Z. THE BIG QUESTION IS WHAT HAPPENS TO THE STRATUS TODAY. RELATIVELY WEAK COLD ADVECTION AND SOME MIXING WITH DRIER AIR AT THE TOP OF A LOW LEVEL INVERSION...IS EXPECTED TO BREAK UP THE CLOUDS FROM WEST TO EAST LATER IN THE AFTERNOON. THUS...GENERAL MVFR CEILINGS LOWLANDS WILL SCATTER OUT BY 22Z...WHILE MVFR/IFR CEILINGS MOUNTAINS WILL ALSO SCATTER AROUND 00Z. FOR TONIGHT...WITH LOW LEVEL MOISTURE...WEAK COLD ADVECTION...AND LOW LEVEL INVERSION INTACT...EXPECT STRATUS CLOUD DECK TO REDEVELOP. AFTER 04Z...LOOK FOR VFR CEILINGS FROM OHIO RIVER WESTWARD...MVFR CEILINGS IN REMAINDER OF LOWLANDS UP TO THE MOUNTAINS...AND MVFR/IFR CEILINGS MOUNTAINS. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY... FORECAST CONFIDENCE: LOW ALTERNATE SCENARIOS: DISSIPATION AND REDEVELOPMENT OF STRATUS THIS PERIOD GREATLY DEPENDS ON HOW MUCH DRY AIR WE CAN MIX DOWN THIS AFTERNOON...AND HOW STRONG THE LOW LEVEL INVERSION IS TONIGHT. 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 EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 CRW CONSISTENCY H H H H H H M M M M M H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY M H H H H H M M M M M M EKN CONSISTENCY L L L M M H M M M M M M PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H M M M M M H AFTER 12Z THURSDAY... IFR CONDITIONS POSSIBLE IN THE MOUNTAINS THRU 12Z THURSDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...JMV/26 NEAR TERM...JMV SHORT TERM...26 LONG TERM...KTB AVIATION...JMV
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
403 AM EST WED NOV 12 2014 .SYNOPSIS... LOW PRESSURE...NOW MOVING INTO QUEBEC...WILL CONTINUE NORTHEAST. BEHIND IT MUCH COLDER AIR WILL SPREAD ACROSS THE OHIO VALLEY AND LOWER GREAT LAKES REGION. HIGH PRESSURE WILL BUILD EAST OVER THE AREA BY SATURDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... COLD FRONT IS NOW WELL EAST OF THE AREA WITH WNW WINDS AND FALLING TEMPS ACROSS THE REGION. RADAR SHOWS THE SWATH OF RAIN ASSOCIATED WITH THE FRONT HAS ALL BUT EXITED THE AREA WITH A FEW RETURNS STILL IN THE EXTREME EAST. WILL HOLD ONTO SLIGHT CHANCE POPS EAST INITIALLY FOR DRIZZLE OR LIGHT RAIN OF SNOW SHOWERS. AFTER DAWN WILL HAVE A SLIGHT CHANCE POP FOR LIGHT RAIN OF SNOW SHOWERS MAINLY IN THE TRADITIONAL LAKE EFFECT AREAS AS NWLY FLOW BRINGS -6 TO -8C AIR ACROSS THE LAKE. FOR THE AFTERNOON WHEN 850MB TEMPS DROP TO -6 TO -8C WILL INCREASE POPS TO CHANCE. AWAY FROM THE LAKE DRY CONDITIONS SHOULD DOMINATE. COULD SEE CLOUDS BEGIN TO BREAK THIS AFTERNOON AS DRIER AIR MOVES IN. FOLLOWING THE HRRR WE SHOULD WARM A BIT TODAY BUT ON BALANCE DO NOT BELIEVE WE WILL SEE AFTERNOON HIGHS REACH MAV NUMBERS SO HAVE CUT 2 TO 3 DEGREES FROM GUIDANCE TO FAVOR MID AND UPPER 30S VS NEAR 40 MOST AREAS. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... AIRMASS STARTS OUT FAIRLY DRY ACROSS THE AREA THIS EVENING. 850MB TEMPS SHOULD BE AROUND -9C TO -10C OVER THE LAKE AND NRN COUNTIES. EVEN WITH THE DRY AIR WOULD EXPECT SNOW SHOWERS OFF THE LAKE BUT ELSEWHERE DRY. OVERNIGHT AN UPPER TROUGH DROPS SOUTHEAST ACROSS THE CENTRAL LAKES ENHANCING LOW LEVEL LIFT FRONT THE LAKE INTO THE SNOWBELT. THE NAM AND SREF ALSO SHOW THE AIRMASS BEGINNING TO MOISTEN ESP ACROSS NERN OHIO AND NWRN PA. WILL BEGIN WITH CHANCE POPS THIS EVENING BUT OVERNIGHT WILL INCREASE TO LIKELY AS CONDITIONS BECOME INCREASINGLY MORE FAVORABLE. ACCUMS LIKELY IN THE 1-2 INCH RANGE FROM LAKE AND NRN ASHTABULA COUNTIES EAST INTO NWRN PA. THURSDAY MODELS SHOW FURTHER MOISTENING WITH THE MOIST LAYER ENCOMPASSING THE FAVORABLE TEMPERATURE RANGE FOR DENDRITIC SNOW GROWTH. STILL...SYNOPTIC LIFT IS WEAK. GIVEN THE ADDED FAVORABLE PARAMETERS WILL CONTINUE LIKELY POPS THROUGH THE MORNING INCREASING TO CATEGORICAL FROM AROUND NOON ON AS LAKE/850MB TEMPS DIFFERENCE RESULTS IN EXTREME INSTABILITY. ACCUMS AT THIS POINT 2 TO 4. THURSDAY EVENING AND NIGHT THE UPPER TROUGH AXIS DROP ACROSS THE AREA. INSTABILITY REMAINS EXTREME AND INVERSION WILL HAVE LIFTED TO CLOSE TO 725MB. BUFKIT ALSO SHOWS SYNOPTIC LIFT ACROSS THE AREA. WITH WINDS VEERING 20-30 DEGREES BELIEVE SNOW WILL REACH FURTHER INLAND AND POSSIBLY BE LESS BANDED SO ADJUSTED LIKELY AND CATEGORICAL AREAS TO REFLECT THIS. HAVE AROUND 3 INCHES IN GRAPHICS. LITTLE CHANGE FOR FRIDAY HOWEVER SNOW SHOULD BE TAPERING AFTERNOON AND EVENING AS THE ARCTIC SURFACE HIGH BUILDS IN FROM THE WEST. WILL HANG ONTO A LOW CHANCE POP FOR LAKE EFFECT SATURDAY. TEMPS REMAIN BELOW NORMAL...MAINLY IN THE 30S FOR HIGHS. && .LONG TERM /SUNDAY THROUGH TUESDAY/... VERY COLD STRETCH OF WEATHER FOR MID-NOVEMBER WILL CONTINUE THROUGH THE EXTENDED FORECAST. THE UPPER LEVEL TROUGH DEEPENS WEST OF THE GREAT LAKES ON SUNDAY AND SUNDAY NIGHT AS A STRONG VORT MAX DIVES SOUTH FROM THE ARCTIC. WILL CONTINUE TO CARRY A CHANCE OF SNOW IN THE FORECAST FOR ALL AREAS ON SUNDAY WITH WEAK ISENTROPIC ASCENT WITHIN THE SOUTHWESTERLY FLOW AHEAD OF THE TROUGH. QPF SHOULD BE LIGHT WITH ONLY A FEW HUNDREDTHS EXPECTED. WE WILL WANT TO KEEP AN EYE ON A WAVE OF LOW PRESSURE TRACKING NORTHEAST FROM THE GULF COAST UP THE APPALACHIANS ON MONDAY. THE ECMWF HAS BEEN TRENDING TOWARDS A A DEEPER AND MORE WESTWARD ADJUSTMENT TO THE UPPER LEVEL TROUGH WHICH COULD RESULT IN THIS LOW BEING PULLED A LITTLE FARTHER NORTH INTO THE OHIO VALLEY. IF THIS IS THE CASE...WE COULD END UP NEEDING HIGHER POPS...BUT COULD ALSO PULL ENOUGH WARM AIR INTO THE SYSTEM TO HAVE PRECIP TYPE ISSUES. FOR NOW WILL KEEP THE FORECAST AS ALL SNOW AND MONITOR MODEL TRENDS. HIGH TEMPERATURES ON MONDAY AND TUESDAY COULD BE AS MUCH AS 20 DEGREES BELOW NORMAL IN THE UPPER 20S TO NEAR 30 DEGREES. MODELS HAVE BEEN FAIRLY CONSISTENT ON BRINGING THIS EVEN COLDER SURGE OF AIR DOWN WITH 850MB TEMPS DROPPING TO AT LEAST -14C. LAKE EFFECT SNOW WILL LIKELY FLARE UP ON MONDAY NIGHT AND TUESDAY AS THE UPPER TROUGH SWINGS THROUGH. THIS COULD BE ANOTHER GOOD SET-UP FOR ACCUMULATING LAKE EFFECT SNOW IN THE SNOWBELT REGION. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... SWATH OF IFR CEILINGS WILL SLOWLY WORK EAST OVERNIGHT AND CEILINGS WILL LIFT TO MVFR. LIGHT RAIN/DRIZZLE WILL LIKELY LINGER INTO THE PREDAWN HOURS ESPECIALLY IN THE SNOWBELT OF EXTREME NE OH/NW PA. CEILINGS MAY IMPROVE TO VFR AND PERHAPS SCATTER OUT WEDNESDAY AFTERNOON AS SUBSIDENCE INCREASES. GUSTY WEST WINDS WILL SETTLE DOWN BY WEDNESDAY EVENING. .OUTLOOK...NON-VFR IN THE SNOWBELT OF NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA LATE WED NIGHT THROUGH FRIDAY. NON-VFR CEILINGS WILL REDEVELOP ELSEWHERE THURSDAY AND CONTINUE INTO FRIDAY. NON-VFR LIKELY SUNDAY WITH SNOW SHOWERS WITH THE NEXT FRONT. && .MARINE... SMALL CRAFT ADVISORIES REMAIN IN EFFECT FOR NEARSHORE WATERS IN ALL AREAS THROUGH THIS AFTERNOON...AND THROUGH THURSDAY NIGHT ON THE EAST HALF OF THE LAKE. WESTERLY WINDS WILL START THE DAY IN THE 20-25 KNOT RANGE BEFORE DECREASING TO 15-20 KNOTS BY LATE AFTERNOON. WESTERLY WINDS WILL REMAIN IN THE 15-20 KNOT RANGE THROUGH THURSDAY THEN SHIFT TO NORTHWESTERLY THURSDAY NIGHT. WINDS WILL SLOWLY DECREASE FRIDAY AFTERNOON AND NIGHT AS HIGH PRESSURE BUILDS OVER THE OHIO VALLEY. ANOTHER COLD FRONT IS EXPECTED TO MOVE ACROSS THE LAKE ON SUNDAY NIGHT WITH ANOTHER VERY COLD AIRMASS TO FOLLOW BEHIND. SMALL CRAFT ADVISORIES WILL BE NEEDED AGAIN FOR THE EARLY PART OF NEXT WEEK. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST FRIDAY FOR LEZ146>149. SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LEZ142>145. && $$ SYNOPSIS...TK NEAR TERM...TK SHORT TERM...TK LONG TERM...KEC AVIATION...KOSARIK MARINE...KEC
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
311 AM EST WED NOV 12 2014 .SYNOPSIS... SIGNIFICANT AIRMASS CHANGE FOR THE NEXT FEW DAYS. HIGH PRESSURE THURSDAY THROUGH SATURDAY. NEXT SYSTEM WITH DEEPER MOISTURE SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... MODELS FINALLY BRING IN THE FIRST STAGE OF PROGRESSIVELY COLDER AIR TODAY AND TONIGHT AS EXPANSIVE CANADIAN HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST. MODELS QUICKLY END THE SCATTERED SHOWERS FROM WEST TO EAST THIS MORNING AS DRIER AIR MOVES IN ALOFT. HOWEVER...THIS FIRST SURGE IS NOT NEARLY COLD ENOUGH TO CHANGE SCATTERED MORNING RAIN SHOWERS TO SNOW BEFORE ENDING. MODELS ALSO SHOW SOME MODEST RECOVERY IN TEMPERATURES TODAY SA THE REAL COLD AIR WILL BE DELAYED SOMEWHAT...BUT HIGHS TODAY WILL REMAIN IN THE 40S. THE MAIN QUESTION THIS PERIOD IS WHETHER OR HOW MUCH THE WIDESPREAD POST FRONTAL STRATUS WILL BREAK THIS AFTERNOON...WHICH IN TURN WILL HELP DETERMINE JUST WHERE HIGH TEMPERATURES OCCUR IN THE 40S. HERE THERE ARE TWO CAMPS. THE NAM APPEARS TO BE THE OUTLIER IN HOLDING THE CLOUDS TODAY AND KEEPING HIGHS MOSTLY IN THE LOWER 40S. THE GFS AND RAP LOOK TO DISSIPATE THE CLOUDS THIS AFTERNOON AND PUSH TEMPS WITH SOME SUNSHINE INTO THE MID AMD UPPER 40S. HAVE TO GO WITH THE MODEL CONSENSUS OF BREAKING THE CLOUDS FROM WEST TO EAST THIS AFTERNOON...AND GO ON THE HIGHER TEMPERATURES SIDE OF THE MAV GUIDANCE. THIS IS REINFORCED BY EVEN THE NAM COMING VERY CLOSE IN WEAKENING THE LOW LEVEL INVERSION AND MIXING OUT THE LOWER LEVEL MOISTURE. WILL LEAN HEAVILY TO THE GFS FOR DETAILS TODAY. FOR TONIGHT...WOULD EXPECT THE LOW LEVEL INVERSION TO STRENGTHEN AGAIN AND HELP REFORM CLOUDS WITH THE LINGERING LOW LEVEL MOISTURE BELOW THIS INVERSION. SO WHILE LEANING BACK TOWARD THE NAM TO BECOME MOSTLY CLOUDY TONIGHT...THE NAM DOES APPEARS TOO COOL IN THE MOUNTAINS. WILL BLEND MOS GUIDANCE FOR TEMPS TONIGHT...WHICH STILL BRINGS MINS DOWN INTO THE UPPER 20S. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... WELL ADVERTISED COLD AIRMASS WILL BE FULLY ENTRENCHED IN THE MIDDLE OHIO VALLEY AND CENTRAL APPALACHIANS THURSDAY AND PERSISTING THROUGH THE DURATION OF THE SHORT TERM FORECAST. OVERALL...CHANGES TO THE FORECAST HAVE BEEN MINIMAL...WITH STRONG HIGH PRESSURE INFLUENCES FROM THE CENTRAL PLAINS AREA. FOR THIS FORECAST PACKAGE...STILL CHASING THE LOW LEVEL MOISTURE AND STREAMLINES FOR THE LOW END CHANCES FOR SNOW SHOWERS IN THE MOUNTAINS. OTHERWISE...MODELS HAVE SHOWN GOOD CONSISTENCY FROM RUN TO RUN FROM TIMING TO LOW LEVEL AIR TEMPERATURES. KEEPING ON THE LOWER SIDE OF GUIDANCE FOR THURSDAY AND FRIDAY...AND DO NOT SEE THE LOWLANDS GETTING OUT OF THE 30S. A LITTLE RECOVERY BRINGS TEMPERATURES INTO THE LOWER 40S FOR SATURDAY AS THE AIRMASS BEGINS TO MODIFY. BY THIS TIME...THE CENTER OF HIGH PRESSURE WILL STILL BE TO THE WEST OVER THE LOWER OHIO VALLEY. THE NEXT FRONTAL SYSTEM BEGINS TO ORGANIZE OVER THE CENTRAL AND SOUTHERN PLAINS BY 00Z SUNDAY. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... NO MAJOR CHANGES FROM OUR THINKING YESTERDAY. WILL HOLD ONTO SOME LINGERING FLURRIES INTO FRIDAY EVENING AS THE MOISTURE BELOW 850 MB CONTINUES TO THIN. STILL DRY ON SATURDAY WITH SUNSHINE FIGURED. HIGH PRESSURE SHIFTS TO OUR EAST SATURDAY EVENING...WILL GO A BIT COLDER CKB TO EKN VCNTY THAN WPC MEDIUM RANGE GUIDANCE...SINCE THE EVENING SHOULD START OUT MOSTLY CLEAR. STRONG WARM AIR ADVECTION IN THE LOWER MISSISSIPPI VALLEY SATURDAY EVENING BECOMES WEAKER AS IT SHIFTS NORTHEAST OVERNIGHT SATURDAY NIGHT. THEN A STRENGTHENING 250 MB JET DEVELOPS BY 12Z SUNDAY BUT SHIFTS EAST OF US BY 00Z MONDAY. SO THINKING DEEPER MOISTURE WILL ADVECT OUR WAY OVERNIGHT SATURDAY NIGHT...WITH SOME LIGHT SNOW POSSIBLE 06Z TO 12Z SUNDAY. WILL LEAVE THE RAIN OR SNOW OPTION FOR THE AFTERNOON. 12Z ECWMF CERTAINLY MILDER ON 850 MB TEMPERATURES AT 18Z SUNDAY THAN 12Z GFS. AS THE STRONGER JET DYNAMICS SHIFT TO THE MID ATLANTIC COAST SUNDAY EVENING...HAVE PRECIPITATION CHANGING TO SNOW SHOWERS AS LOW LEVEL COLD AIR ADVECTION BEGINS AGAIN. AS OF NOW...HAVE MINOR SNOW ACCUMULATIONS LATE SATURDAY NIGHT THROUGH SUNDAY NIGHT...SO STILL DO NOT SEE NEED TO INCLUDE ANY HAZARDS IN HAZARDOUS WEATHER POTENTIAL CURRENTLY. THE COLDER AIR ON MONDAY SHOULD QUICKLY DRY OUT. YET...AT THIS DISTANCE WILL STILL LEAVE SOME CHANCE POPS FOR SNOW SHOWERS OVER THE WEST VIRGINIA MOUNTAIN COUNTIES MONDAY MORNING. DRY/COLD/TRANQUIL FIGURED FOR MONDAY NIGHT INTO TUESDAY. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... 06Z WEDNESDAY THRU 06Z THURSDAY... COLD FRONT APPROACHING A CKB-CRW LINE AT 06Z...WILL EXIT THE MOUNTAINS BY 10Z. VFR CONDITIONS IN LIGHT SW FLOW AHEAD OF THE FRONT WILL GIVE WAY TO GENERAL MVFR CEILINGS ACCOMPANYING AND FOLLOWING THE FRONT. A BAND OF LIGHT SHOWERS WILL ACCOMPANY THE FRONT...WITH BRIEF IFR CEILINGS POSSIBLE IN THE BAND OF SHOWERS. CIGS MAY DIP TO IFR IN THE MOUNTAINS FOR A TIME EARLY WED MORNING BEHIND THE FRONT...AFFECTING BKW AND EKN. MOST OF THE SHOWERS WILL END BY 12Z AS DRIER AIR MOVES IN ALOFT. THE BIG QUESTION IS WHAT HAPPENS TO THE STRATUS AFTER 12Z. RELATIVELY WEAK COLD ADVECTION AND SOME MIXING WITH DRIER AIR AT THE TOP OF THE INVERSION...IS EXPECTED TO BREAK UP THE CLOUDS FROM WEST TO EAST DURING THE AFTERNOON. THUS...GENERAL MVFR CEILINGS LOWLANDS WILL IMPROVE AS STATED...WHILE MVFR/IFR CEILINGS MOUNTAINS WILL ALSO IMPROVE THIS. BY 22Z...GENERALLY SCATTERED STRATOCU AREA WIDE. FOR TONIGHT...WITH LOW LEVEL MOISTURE...COLD ADVECTION...AND LOW LEVEL INVERSION INTACT...EXPECT STRATUS CLOUD DECK TO REDEVELOP. AFTER 03Z...LOOK FOR VFR CEILINGS FROM OHIO RIVER WESTWARD...MVFR CEILINGS IN REMAINDER OF LOWLANDS UP TO THE MOUNTAINS...AND MVFR/IFR CEILINGS MOUNTAINS. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY... FORECAST CONFIDENCE: LOW ALTERNATE SCENARIOS: DISSIPATION AND REDEVELOPMENT OF STRATUS THIS PERIOD GREATLY DEPENDS ON HOW MUCH DRY AIR WE CAN MIX DOWN THIS AFTERNOON...AND HOW STRONG THE LOW LEVEL INVERSION IS TONIGHT. 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 WED 11/12/14 UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19 EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14 CRW CONSISTENCY H L M H H H H H H M M M HTS CONSISTENCY H H H H H H H H M H H H BKW CONSISTENCY H M M M M M M M M M M M EKN CONSISTENCY H H M L M M M M M M M M PKB CONSISTENCY H H H H H H M M M H H H CKB CONSISTENCY H M M M H H H H H M M M AFTER 06Z THURSDAY... IFR CONDITIONS POSSIBLE IN THE MOUNTAINS THRU 12Z THURSDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...JMV/26 NEAR TERM...JMV SHORT TERM...26 LONG TERM...KTB AVIATION...JMV
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
937 PM EST THU NOV 13 2014 .SYNOPSIS... PROGRESSIVELY COLDER AIR WILL CONTINUE TO PUSH INTO THE REGION...AND WILL LAST INTO NEXT WEEK. THIS PROLONGED SPELL OF WELL BELOW NORMAL TEMPERATURES WILL BE ACCOMPANIED BY THE FIRST SIGNIFICANT LAKE EFFECT SNOW OF THE SEASON ACROSS THE NORTHWEST SNOWBELT. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... FRONTOGENETICALLY FORCED SNOW/RAIN THAT BROUGHT A COATING OF SNOW TO SOME GRASSY SURFACES OVER THE LOWER SUSQ VALLEY IS SHOWING THE DWINDLING TREND THAT WAS ADVERTISED BY THE HRRR AS THE PARENT UPPER JET STREAK LIFTS AWAY FROM THE REGION. LITTLE MORE THAN A FEW LINGERING LIGHT SNOW/RAIN SHOWERS AND SOME FLURRIES ARE LEFT BEHIND OVER CENTRAL AND EASTERN AREAS. FURTHER TO OUR NW...BANDED LAKE EFFECT IS STARTING TO ORGANIZE BUT IT HAS BEEN SLOW. THIS WILL BECOME THE MAIN MODE OF PRECIP THAT WE WILL BE DEALING WITH FOR THE NEXT 24-36 HOURS AS THE WINDS BECOME BETTER ALIGNED OVERNIGHT INTO FRIDAY. WE ARE CONTINUING THE LAKE EFFECT SNOW WARNING THROUGH 00Z SAT FOR WARREN COUNTY...AND THE LAKE EFFECT SNOW ADVISORY ACROSS MCKEAN COUNTY THROUGH THE SAME PERIOD. FROM EARLIER... PERSISTENT LIGHT TO MDT...NWRLY BOUNDARY LAYER FLOW /COUPLED WITH DEEP COLD AIR AND NEARLY A 20C LAKE-850 MB T DIFF...ALONG WITH THE LONG DURATION OF THIS LES EVENT/ LOOKS VERY FAVORABLE FOR HEAVY SNOW AMOUNTS ACROSS THE PERENNIAL SNOWBELT OF NW WARREN COUNTY WHERE OVER 1 FOOT LOOKS POSSIBLE BY FRIDAY NIGHT...WITH SOME ADDITIONAL ACCUMS LIKELY HEADING INTO SATURDAY. THE MEAN WIND IN THE LAYER STEERING THE LAKE EFFECT BANDS WILL VARY BY ABOUT 30 DEG FROM 285-315 DEG TONIGHT INTO FRIDAY...WITH EVEN SOME PULSES OF DRIER AIR CREATING A FEW LULLS IN THE ACTION. STILL...IT`S BEST AT THIS POINT TO PLACE THIS EVENT INTO ONE LONG PACKAGE AND PROVIDE PLENTY OF LEAD TIME FOR THIS FIRST SIGNIFICANT LES EVENT. THE REST OF THE NW MTNS OUTSIDE OF THE LES ADVISORY DOWN THRU THE LAURELS WILL SEE ACCUMULATING SNOW ON THE ORDER OF A FEW TO SVRL INCHES BY THE TIME ITS ALL OVER SATURDAY. HOWEVER...AMOUNTS IN ANY ONE GIVEN 12-24 HOUR PERIOD WON`T REALLY ADD UP TO ADVISORY AMOUNTS. THE EXCEPTION MAY BE ON THE WEST FACING SLOPES OF THE LAURELS SKI COUNTRY WHERE 6 TO 8 INCHES IS POSSIBLE BY 12Z SATURDAY. AFTER THE PASSAGE OF THE COASTAL LOW LOW LATER TONIGHT...CLOUD BASES WITH LIFT ACROSS THE CENTRAL MTNS AND SUSQ VALLEY WITH FLURRIES AND ISOLATED SNOW SHOWERS. LOWS TONIGHT WILL VARY FROM THE L20S ACROSS THE NRN AND WRN MTNS...TO THE MID AND UPPER 20S IN THE SE. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... FAVORABLE LES SNOW PATTERN CONTINUES FOR THE NW MTNS...WITH FREQUENT SNOW SHOWERS AND LIGHTER ACCUMS FOR THE NORTH-CENTRAL MTNS AND LAURELS AS A BROAD AREA OF STEEP LOW TO MID LEVEL LAPSE RATES AND POCKET OF -15 TO -20C AIR AT 700 MB TRAVERSES THE AREA. VARIABLE CLOUDINESS WILL BE FOUND ACROSS THE CENTRAL MTNS WITH FLURRIES AND ISOLATED TO SCTD SNOW SHOWERS THAT COULD BRIEFLY WHITEN THE GROUND. TEMPS WILL BE 12-15F BELOW NORMAL WITH MAXES RANGING FROM AROUND 30F ACROSS THE NRN AND WRN MTNS...TO THE L40S IN THE SE. && .LONG TERM /SATURDAY THROUGH THURSDAY/... COLD PATTERN WILL CONTINUE WITH WELL-BELOW AVERAGE TEMPERATURES THROUGH MUCH OF NEXT WEEK... ANOMALOUS UPPER LEVEL RIDGING CENTERED OVER THE YUKON/ALASKA WILL SUSTAIN AND MAINTAIN A DEEP TROUGH AND UNSEASONABLY COLD AIRMASS OVER THE AREA THROUGH THE END OF THE PERIOD. FORECAST CONFIDENCE REMAINS VERY HIGH IN A PROLONGED STRETCH OF COLDER THAN NORMAL TEMPERATURES. THE SIGNIFICANT...LONG DURATION LAKE EFFECT SNOW EVENT OVER THE NW SNOWBELT WILL WIND DOWN BY SATURDAY NIGHT...AS THE LOW LEVEL FLOW BACKS TO THE WSW AND INVERSION HEIGHTS COLLAPSE UNDER INCREASING SUBSIDENCE ASSOCIATED WITH SHORTWAVE RIDGE AND SFC HIGH PRESSURE MIGRATING EWD FROM THE CENTRAL APPALACHIANS OFF THE MID ATLANTIC COAST. IN MOST LOCATIONS...SATURDAY WILL BE COLD AND DRY WITH DAYTIME TEMPERATURE DEPARTURES BETWEEN 10 AND 15 DEGREES BELOW MID NOVEMBER CLIMATOLOGY. MODELS SHOW A LEAD SHORTWAVE CROSSING THE ERN GREAT LAKES ON EARLY SUNDAY WHICH COULD SPREAD SOME LIGHT RAIN/SNOW INTO THE AREA. RELOADING CENTRAL US TROUGH BECOMES WELL ESTABLISHED BY 12Z MONDAY WITH CORE OF NEGATIVE HEIGHT ANOMALIES APPROACHING -3 STD OVER THE UPPER MIDWEST. THERE IS A BROAD CONSENSUS IN A BROAD AREA OF PCPN BLOSSOMING OVER THE AREA ON MONDAY AS MOISTURE AND LIFT BECOME ENHANCED EAST OF THE DEEP TROUGH ALONG SHARPENING FRONTAL AXIS. PTYPES WILL REMAIN CHALLENGING BUT IT LOOKS LIKE ANOTHER POSSIBLE MIX OR CHANGEOVER EVENT FOR AREAS EAST OF THE ALLEGHENY FRONT. THAT SAID...THERE IS ENOUGH SUPPORT TO RAISE POPS INTO THE LKLY RANGE FOR DAY 4.5/5. AN EVEN COLDER SURGE OF MODIFIED ARCTIC AIR SEEMS POISED TO BLAST INTO THE REGION BEHIND THIS SYSTEM ON TUESDAY AND PERSIST THRU THE MIDDLE OF NEXT WEEK. THE OVERALL BROAD CYCLONIC FLOW PATTERN WILL FAVOR LAKE EFFECT AND TERRAIN ENHANCED SNOW SHOWERS OVER THE NW MTNS WITH COLD AND DRY CONDITIONS FROM THE CENTRAL RIDGES INTO THE LWR SUSQ VLY. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... AS THE UPPER LEVEL TROUGH SWINGS THROUGH THE NORTHEAST THIS EVENING...EXPECT CIGS AT BFD AND JST TO REMAIN IN THE 08-16KFT RANGE MOST OF THE EVENING. CIGS AND VSBYS AT BFD SHOULD REMAIN IFR THROUGH THE EVENING AND INTO TOMORROW MORNING AS THE LAKE EFFECT FLOW SHOULD REMAIN PERSISTENT THROUGH THIS TIMEFRAME. KJST IS LESS LIKELY TO EXPERIENCE SIG VIS REDUCTIONS /COMPARED TO KBFD/ DUE TO IT/S DISTANCE FROM THE LAKES. HOWEVER...OCNL DIPS TO IFR VSBY BTWN 00Z TO 10Z FRIDAY AND TOMORROW EVENING THROUGH 12Z SAT ARE EXPECTED AS THE DEEP COLD AND MOIST POST-FRONTAL AIR ASCENDS THE HIGHER TERRAIN OF THE ALLEGHENIES. MOISTURE FROM A DEVELOPING/WEAK LOW /TRACKING NE FROM THE CAROLINAS/ WILL PRODUCE PERIODS OF LGT SNOW/MVFR VSBYS AT KMDT/KLNS THROUGH THE FIRST HALF OF THIS EVENING. IN BTWN...KUNV AND KAOO WILL EXPERIENCE OCNL MVFR CIGS THIS TONIGHT. ARRIVAL OF DRIER AIR MASS BEHIND THE FRONT LATE TONIGHT WILL BRING RISING CIGS OVR MOST OF THE REGION ALONG AND SE OF A LINE FROM KAOO TO KELM. OUTLOOK... FRI...PM SNOW SHOWERS/REDUCED VSBYS POSS AT KBFD AND JST. SAT...AM SNOW SHOWERS/REDUCED VSBYS POSS AT KBFD AND JST. SUN...SNOW SHOWERS/REDUCED VSBYS POSS AT KBFD. MON...LGT SNOW/LOW CIGS POSS NW HALF OF PA. RAIN/LOW CIGS POSS SE. && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST FRIDAY FOR PAZ005. LAKE EFFECT SNOW WARNING UNTIL 7 PM EST FRIDAY FOR PAZ004. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LAMBERT LONG TERM...STEINBUGL AVIATION...LAMBERT/CERU
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AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1044 PM EST THU NOV 13 2014 .SYNOPSIS... LOW PRESSURE WAS OFF THE MID ATLANTIC COAST TONIGHT AND WILL DEEPEN OFF THE NEW ENGLAND COAST ON FRIDAY. ARCTIC HIGH PRESSURE WILL BUILD INTO THE REGION INTO SATURDAY. OUR NEXT POTENTIAL WEATHER MAKER MOVES ACROSS THE AREA SUNDAY THROUGH MONDAY WITH GUSTY WINDS AND COLD TEMPERATURES BEHIND IT ON TUESDAY. && .NEAR TERM /THROUGH FRIDAY/... AS OF 1035 PM EST THURSDAY... THE WATER VAPOR LOOP SHOWED A SHORT WAVE CROSSING INTO EASTERN VIRGINIA. THE BETTER AREAL COVERAGE OF RAIN WAS MOVING EAST WITH THIS WAVE. LAST FEW RUNS OF THE HRRR HAD A MAJORITY OF THIS PRECIPITATION EAST OF THE FORECAST AREA BY 08Z/3AM. ANOTHER ELONGATED SHORT WAVE WAS OVER PENNSYLVANIA AND WEST VIRGINIA. SCATTERED SNOW SHOWERS ASSOCIATED WITH THIS FEATURE WERE MOVING ACROSS EASTERN SECTIONS OF WEST VIRGINIA. MSAS ANALYSIS SHOWED PRESSURE FALLS AND A DEEPENING LOW WELL OFF THE DELMARVA PENINSULA. AS THIS LOW CONTINUES TO STRENGTHEN...THE MAGNITUDE OF THE NORTHWEST FLOW COLD AIR ADVECTION INCREASES TONIGHT AND THIS WILL BE THE TIME WHERE OUR REALLY GOOD SURGE OF COLDER AIR COMMENCES ACROSS THE REGION. LOWS TONIGHT WILL RANGE FROM THE UPPER TEENS TO LOWER 20S ACROSS THE MOUNTAINS WITH UPPER 20S TO LOWER 30S ACROSS THE PIEDMONT. ON FRIDAY...NORTHWEST FLOW WILL CONTINUE AND HELP MAINTAIN UPSLOPE CLOUDS ACROSS THE MOUNTAINS THROUGH AT LEAST MIDDAY. IN THE EAST...THE CLOUD COVER WILL CLEAR EARLY GIVEN A DECENT DOWNSLOPE COMPONENT. DRIER AIR WILL EVENTUALLY WIN OUT IN THE MOUNTAINS TOO...WITH MOST REGIONS AT LEAST MOSTLY SUNNY BY THE LATE AFTERNOON. HIGH TEMPERATURES WILL RANGE FROM THE LOW TO MID 30S ACROSS THE MOUNTAINS WITH READINGS AROUND 40 TO THE LOWER 40S ACROSS THE PIEDMONT. SOME OF THE FORECAST HIGHS...ESPECIALLY THOSE IN THE WEST...ARE ONLY EXPECTED TO BE A COUPLE OF DEGREES ABOVE THE RECORD LOW MAXIMUMS FOR THE DAY. SPECIFIC LOW MAXIMUM RECORDS FOR FRIDAY AND SATURDAY ARE IN THE CLIMATE SECTION OF THIS DISCUSSION. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/... AS OF 205 PM EST THURSDAY... COLD HIGH PRESSURE WILL SLIDE EAST ACROSS THE AREA FRIDAY NIGHT AND BE ABOUT OVERHEAD BY SATURDAY MORNING. THIS WILL BRING CLEAR SKIES UNDER STRONG SUBSIDENCE ALONG WITH VERY COLD EARLY MORNING TEMPS SATURDAY AS THE CORE OF THE COLDEST 85H SETTLES OVERHEAD. THIS ALONG WITH GREAT RADIATIONAL COOLING SUPPORTS LOWS IN THE TEENS WEST TO LOW/MID 20S EAST. RIDGING SHIFTS SLOWLY EAST DURING SATURDAY BUT SHOULD HANG ON LONG ENOUGH TO KEEP THINGS MOSTLY SUNNY BUT STILL ON THE COLD SIDE WITH ONLY ABOUT A 3-5+ DEGREE RISE IN 85H TEMPS. HOWEVER EVEN WITH SOME SLIGHT WARMING ALOFT INFLUX OF HIGH LEVEL CLOUDS MAY HOLD TEMPS SLIGHTLY BELOW MOS...MAINLY 38-45. MID LEVEL RIDGING STARTS TO BREAK DOWN SATURDAY NIGHT INTO SUNDAY AS A DEVELOPING 5H TROUGH STARTS TO APPROACH FROM THE WEST. ONSET OF BETTER MID/HIGH LEVEL MOISTURE LIKELY TO BRING INCREASING CLOUDS SATURDAY NIGHT BUT LIKELY THIN ENOUGH EARLY ON TO ALLOW TEMPS TO DIP INTO THE 20S MOST SPOTS BUT STILL DRY. SYSTEM HEADS EAST TOWARD THE REGION BUT QUITE DISORGANIZED INITIALLY WITH NORTHERN STREAM ENERGY PASSING TO THE NW AND THE MAIN SOUTHERN STREAM WAVE STILL HANGING BACK ALONG THE GULF COAST. SOME SOLUTIONS SUCH AS THE GFS REMAIN FAST TO BRING SOME LEAD LIGHT PRECIP NE INTO THE AREA ON SUNDAY WHILE OTHERS PER THE LATEST ECMWF QUITE SLOW WITH LITTLE PRECIP AT ALL DURING THE DAY. GIVEN THE STRONG UPPER JET AND PAST HISTORY OF WEAK LIFT SYSTEMS DEVELOPING PRECIP FASTER...LEFT IN SOME CHANCE POPS SUNDAY AFTERNOON WITH SOME LIGHT SNOW...MAINLY FAR NW WHERE A NAM/GFS MIX WOULD SUPPORT A MORE FROZEN SCENARIO. TEMPS TO WARM A BIT UNDER WARM ADVECTION ALOFT IN ADVANCE OF THE INITIAL FRONT WITH HIGHS MOSTLY 40S EXCEPT LOW 50S SE. DIGGING/AMPLIFYING 5H TROUGH WILL START TO ARRIVE FROM THE NW LATER SUNDAY NIGHT AND HELP ENHANCE MOISTURE COMING NE WITH THE SOUTHERN SHORTWAVE. HOWEVER JUST HOW FAST THIS HAPPENS KEY TO PRECIP COVERAGE SUNDAY NIGHT AS WELL AS THE TEMP PROFILE ALOFT GIVEN DECENT 85H WARM ADVECTION. LATEST GFS FASTER BUT STILL HAS BEST LIFT CLOSER TO THE BAROCLINIC ZONE ALONG THE APPALACHIANS AS WEAK SURFACE WAVES LIFT NE INTO THE CAROLINAS LATE. NEW ECMWF MUCH SLOWER WITH THE SOUTHERN SYSTEM LAGGING FARTHER SOUTH WHICH WOULD RESULT IN ONLY SPOTTY PRECIP. FOR NOW KEPT LIKELY POPS FOR LATER SUNDAY NIGHT BUT WARMER WITH PERHAPS ONLY THE HIGHER ELEVATIONS OVER THE FAR NW STAYING COLD ENOUGH ALOFT FOR SNOW. OTRW LOWS STEADYING OUT IN THE 30S WEST TO AROUND 40 SE. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 PM EST THURSDAY... GENERAL FLAVOR OF MODEL GUIDANCE REMAINS THE SAME FOR THE EXTENDED PERIOD AS A COLD FRONT MOVES THROUGH THE REGION SUNDAY NIGHT WITH A WAVE RIDING UP ALONG THE FRONT FROM THE SOUTHEAST. LOW LEVEL WARM AIR SURGING IN AHEAD OF THIS SYSTEM SHOULD HAVE PTYPE MOSTLY LIQUID UNTIL COLD AIR PUSHES IN FROM THE NORTHWEST LATER ON MONDAY...AND WE TRANSITION OVER TO SNOW AS BULK OF SYNOPTIC PCPN PULLS OUT. UPSLOPE SNOW SHOWERS WILL THEN AFFECT AREAS WEST OF THE BLUE RIDGE MONDAY NIGHT INTO TUESDAY WITH SOME ACCUMULATIONS POSSIBLE FOR THE WESTERN SLOPES. MAY SEE AN UPTICK IN SNOW SHOWERS TOWARD DAYBREAK TUESDAY AS A VIGOROUS SHORT WAVE MOVES SWINGS THROUGH THE BASE OF THE UPPER TROF AND PASSES OVER THE REGION. HIGH PRESSURE WILL THEN PUSH IN FROM THE SOUTHEAST AS MOISTURE RETREATS AND WE ARE QUIET AND COLD FOR LATE TUESDAY INTO WEDNESDAY. HIGH PRESSURE SLIDES OFF TO OUR EAST THURSDAY...ALLOWING SOUTHERLY RETURN FLOW TO MODERATE TEMPERATURES A BIT BEFORE WE SEE AFFECTS OF NEXT SYSTEM APPROACHING FROM THE MISSISSIPPI VALLEY THURSDAY NIGHT. IT LOOKS LIKE MONDAY NIGHT THROUGH TUESDAY NIGHT WILL SEE THE BEST CHANCES FOR WINDY CONDITIONS WITH GOOD DOWNWARD MOMENTUM TRANSFER ABLE TO BRING STRONG LOW LEVEL WINDS TO THE SURFACE. && .AVIATION /04Z FRIDAY THROUGH TUESDAY/... AS OF 705 PM EST THURSDAY... SHORT-WAVE MOVING THROUGH EASTERN VA BRINGING LIGHT RAIN AND LIGHT SNOW THROUGHOUT THE APPALACHIANS AND WESTERN VA. THE DISTURBANCE WILL CLEAR OUT BY 12Z FRIDAY AS WELL AS LOW CEILING HEIGHTS. MVFR AND IFR CONDITIONS IN THE MOUNTAINS...INCLUDING KLWB AND KBLF... WILL CLEAR BY THE END OF THE TAF PERIOD 00Z SATURDAY/7PM FRIDAY. HIGH CONFIDENCE WITH TIMING OF THE IMPROVEMENT TO VFR AND THE TRACK OF THE SURFACE LOW MOVING NORTHEAST AWAY FROM THE MID ATLANTIC COAST. NW WINDS WILL STRENGTHEN TO 10-15 KTS WITH GUSTS UP TO 20 KTS TONIGHT INTO FRIDAY MORNING...THEN WEAKEN TO AROUND 5 KTS 00Z SATURDAY AS HIGH PRESSURE SYSTEM BUILDS IN. THE HIGH WILL BRING IN DRY AIR AND COLDER TEMPERATURES AS WELL. EXTENDED DISCUSSION... AN UPPER LEVEL TROUGH WILL DEVELOP OVER THE EASTERN U.S. AND MAKE ITS WAY NORTHEAST THROUGH SATURDAY. ARCTIC HIGH PRESSURE WILL KEEP MOST AREAS VFR INTO SATURDAY. THE EXCEPTION MAY BE SOME LATE NIGHT RIVER OR VALLEY FOG. ON SUNDAY INTO MONDAY...A COLD FRONT IS EXPECTED TO MOVE THROUGH THE REGION. THIS WILL BRING SUB-VFR CONDITIONS AND A WINTRY MIX OF PRECIPITATION. MODELS ARE COMING IN WARMER...SO THE TREND IS FOR MORE RAIN AND LESS WINTER PRECIPITATION THREAT. MOST WINTER PRECIPITATION SHOULD BE CONFINED TO THE MOUNTAINS...IMPACTING KLWB/KBLF TO SOME EXTENT...BUT BY NO MEANS A SIGNIFICANT WINTER EVENT. MORE WIDESPREAD -SHSN EXPECTED BEHIND THE FRONT MON NIGHT INTO TUE WITH SOME ACCUMULATIONS POSSIBLE AT THAT TIME...AGAIN MAINLY IMPACTING BLF/LWB. GUSTY NORTHWEST WINDS ARE EXPECTED BEHIND THE SYSTEM ON TUESDAY. && .CLIMATE... RECORD COOLEST HIGHS FRI NOV 14TH BLACKSBURG VA...35 IN 1986 BLUEFIELD WV....29 IN 1975 DANVILLE VA.....39 IN 1997 ROANOKE VA......37 IN 1976 LEWISBURG WV....30 IN 1975 LYNCHBURG VA....37 IN 1996 SAT NOV 15TH BLACKSBURG VA...32 IN 1976 BLUEFIELD WV....23 IN 1969 DANVILLE VA.....41 IN 1986 ROANOKE VA......34 IN 1969 LEWISBURG WV....29 IN 1995 LYNCHBURG VA....36 IN 1969 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...DS NEAR TERM...AMS/DS SHORT TERM...JH LONG TERM...MBS AVIATION...AMS/DS CLIMATE...DS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
441 AM EST WED NOV 12 2014 .SYNOPSIS... AN ARCTIC AIR MASS WILL SLOWLY SPREAD FROM THE MIDWEST TO EAST OF THE APPALACHIANS TODAY BEHIND A COLD FRONT THAT WILL MOVE THROUGH THE REGION THIS MORNING. WEAK WEATHER SYSTEMS WILL BRING A CHANCE FOR LIGHT PRECIPITATION...SOME IN THE FORM OF WINTER PRECIPITATION TO THE MOUNTAINS...THURSDAY AND AGAIN SUNDAY. OTHERWISE...HIGH PRESSURE WILL DOMINATE THE AREA FOR FRIDAY AND SATURDAY WITH MUCH BELOW NORMAL TEMPERATURES EXPECTED. && .NEAR TERM /THROUGH TONIGHT/... AS OF 400 AM EST WEDNESDAY... TWO CONCERNS THROUGH THE NEAR TERM...FIRST THE FRONT MOVING THROUGH THE REGION THIS MORNING...BRINGING THE INITIAL SURGE OF COLDER...SOON TO BE ARCTIC AIR...AND A COMBINATION CLIPPER/SOUTHERN STREAM SYSTEM EXPECTED TO AFFECT THE AREA LATE TONIGHT/EARLY THURSDAY. A VARIETY OF AIR MASSES IN PLACE EARLY THIS MORNING...WITH ARCTIC AIR BEGINNING TO OOZE INTO AREAS WEST OF THE ALLEGHANY FRONT...A MARITIME AIR MASS STILL DOMINATING AREAS EAST OF THE BLUE RIDGE IN RESPONSE TO THE OFFSHORE UPPER/COASTAL LOW...AND A COL AREA IN BETWEEN THE ALLEGHANY FRONT AND THE BLUE RIDGE. TO THE EAST...DENSE FOG HAS PERSISTED ALONG THE FAR SOUTHEASTERN COUNTIES BORDERING THE AKQ/RAH CWA. THE WESTERN EDGE OF THE FOG ATTEMPTS TO ERODE...WHILE THE EASTERN EDGE PERSISTS. ISSUED AN SPS EARLIER AND WILL LIKELY CONTINUE THIS ROUTE FOR NOW SINCE IT IS CONFINED TO THE EASTERN PORTIONS OF HALIFAX...CHARLOTTE...AND CASWELL. IN BETWEEN...THE AIR MASS HAS REMAINED DRY...MOSTLY FOG FREE...AND WITH CLEAR SKIES. TO THE WEST...UPSLOPE LOW CLOUDS QUICKLY EVOLVING BEHIND THE FRONTAL BOUNDARY...WHICH WAS NEAR AN HSP-BCB- TNB LINE AT 09Z. ONLY A FEW SPRINKLES NOTED BEHIND THE FRONT WITH AN ANTECEDENT VERY DRY AIR MASS IN PLACE...AND THAT REALLY SHOULD BE ABOUT IT. HAVE TAPERED POPS FROM LOW CHC UPSLOPE AREAS OF THE ALLEGHANYS TO NEAR ZERO ALONG THE BLUE RIDGE AND EAST...WITH POPS DROPPING BELOW MENTIONABLE BY 17Z ALL AREAS. CAA WILL BE SLOW TO PROGRESS EAST AND 850MB TEMPS REMAIN ABOVE 0C UNTIL LATE IN THE NEAR TERM...THEN ONLY DROPPING BELOW 0C IN FAR WESTERN AREAS. DOWNSLOPE WEST WINDS AND ABUNDANT INSOLATION WILL LEAD TO A LARGE GRADIENT IN MAX TEMPS TODAY FROM THE UPPER 40S WESTERN MOUNTAINS TO STILL LOWER 70S EASTERN PIEDMONT AREAS. THUS...NEAR SEASONAL WEST TO WELL ABOVE EAST...NOT ARCTIC BY ANY MEANS YET TODAY. OVERNIGHT...AND FAIRLY QUICKLY...A WEAK CLIPPER SHORT WAVE WILL APPROACH FROM THE NORTHWEST IN THE BROAD UPPER TROUGH CENTERED NEAR HUDSON BAY. MEANWHILE...A SOUTHERN STREAM SHORT WAVE WILL MOVE RAPIDLY FROM THE CENTRAL GULF NORTHEASTWARD INTO THE SOUTHEAST STATES. THESE SYSTEMS FORTUNATELY ARE NOT EXPECTED TO PHASE UNTIL WELL OFF THE EAST COAST. THE DRY AIR MASS AND UNPHASED...POOR DYNAMICS WILL RESULT IN ONLY LIGHT PCPN...MUCH OF WHICH MAY BE REALIZED AS VIRGA. MODEL QPF IS MAINLY ONLY A FEW HUNDREDTHS OF AN INCH. THE MOST LIKELY AREAS FOR PCPN SHOULD BE EAST OF THE BLUE RIDGE. THE MAIN CONCERN WILL BE WHETHER OR NOT SFC/UPPER-LEVEL TEMPS ARE COLD ENOUGH FOR ANY WINTER PCPN. WITH 850MB TEMPS ONLY EXPECTED TO BE BELOW 0C WEST OF THE ALLEGHANY FRONT AND POPS GENERALLY ONLY 20 PERCENT AT BEST THUS NO MEASURABLE QPF..BASICALLY A NON-EVENT...HAVE CONFINED MENTION OF WINTER PCPN...MAINLY -IP...TO ELEVATIONS ABOVE 3000 FEET IN WESTERN NC COUNTIES EARLY THU. && .SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/... AS OF 300 AM EDT WEDNESDAY... MODELS CONTINUE TO ADVERTISE A COLD FRONT STALLING OVER THE CAROLINAS WEDNESDAY NIGHT AND GENERATING A SURFACE WAVE OVER SOUTH CAROLINA THURSDAY MORNING. ONE SLIGHT DIFFERENCE IN THE 00Z MODELS IS THE STALLING OF THE 85H FRONT IS EXPECTED TO BE FARTHER NORTH THAN PREVIOUS RUNS. IN THIS NEW SCENARIO...85H WINDS BACK TO THE SOUTHWEST AND MORE WARM MOIST AIR AND ISENTROPIC LIFT IS PUSHED INTO THE FORECAST AREA. THIS WILL INCREASE THE CHANCES FOR PARTS OF THE AREA TO RECEIVE MEASURABLE RAINFALL THURSDAY. THIS MOISTURE WILL STILL NEED TO OVER COME DRY AIR...THEREFORE WILL MAINTAIN SLIGHT CHANCE POPS ALONG THE VA/NC BORDER SOUTH IN THE MORNING...THEN INTO THE PIEDMONT DURING THE AFTERNOON AND EVENING. SINCE THE 85H BOUNDARY IS FARTHER NORTH...THE CHANCES FOR A WINTRY MIX AT THE BEGINNING AND END OF THE EVENT IS LOWER. IF ANYONE WOULD SEE SNOW LATE THURSDAY AFTERNOON/NIGHT...IT WILL BE THE WESTERN SLOPES OF SOUTHEASTERN WEST VIRGINIA AS THE UPPER LEVEL TROUGH TRACKS OVER THE OHIO VALLEY. MOIST NORTHWEST FLOW WILL LIKELY KEEP CLOUDS ACROSS THE MOUNTAINS INTO FRIDAY AND MAINLY ALONG FAVORED WESTERN SLOPES. SHALLOW MOISTURE AND UPSLOPE WINDS MAY BE ENOUGH FOR SCATTERED FLURRIES IN THE FAR WEST INTO FRIDAY MORNING. HIGH TEMPERATURES THURSDAY WILL RUN 15F-20F COLDER THAN NORMAL WITH READINGS IN THE LOWER 40S WEST TO UPPER 40S EAST. FRIDAYS TEMPERATURES WILL RANGE FROM THE L/M 30S ACROSS THE MOUNTAINS AND L/M 40S EAST...WHICH IS 20F-25F COLDER THAN NORMAL. ONE PIECE OF GOOD NEWS IS THAT THE WINDS WILL NOT BE AS STRONG AS PREVIOUSLY FORECASTED. HOWEVER...WIND CHILL TEMPERATURES THURSDAY AND FRIDAY WILL BE AROUND 10F COLDER THAN THE ACTUAL TEMPERATURE. FRIDAY MORNING WIND CHILL VALUES COULD BE AS LOW AS THE MID TEENS TO LOWER 20S ACROSS THE MOUNTAINS AND IN THE M/U 20S IN THE EAST. && .LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 300 PM EST TUESDAY... MODELS HAVE THE SAME OVERALL FLAVOR THOUGH THE EXTENDED PERIOD WITH MAIN DIFFERENCES IN TIMING AND MAGNITUDE OF NEXT SHOT OF COLD AIR. SATURDAY IS LOOKING LIKE A DECENT START TO THE WEEKEND. WHILE TEMPS WILL CONTINUE TO BE WELL BELOW NORMAL...THE UPPER FLOW WILL FLATTEN OUT A BIT AND WE WILL START TO SEE SOME WARMER AIR BEGINNING TO MOVE AS THE SURFACE HIGH SLIDES TO OUR EAST AND WINDS BECOME SOUTHERLY. THIS WILL BE A SHORT REPRIEVE AS THE NEXT UPPER SHORT WAVE SHARPENS THE FLOW AGAIN AND THE NEXT SHOT OF COLD AIR MOVES IN BEHIND A COLD FRONT ON SUNDAY. GENERALLY EXPECTING PTYPE TO BE LIQUID ON SUNDAY... TRANSITIONING TO SNOW SHOWERS SUNDAY NIGHT INTO MONDAY. IT APPEARS THAT PROLONGED NW FLOW WILL KEEP SNOW SHOWERS GOING FOR THE HIGHER ELEVATIONS WEST OF THE BLUE RIDGE THROUGH THE FIRST PART OF NEXT WEEK WITH SOME ACCUMULATIONS POSSIBLE. LOWER ELEVATIONS WILL HAVE DIURNAL PTYPE CHANGES WHICH SHOULD DISCOURAGE SNOW FROM STICKING AROUND DURING THE DAYLIGHT HOURS. IT ALSO LOOKS TO BE BLUSTERY AS THE COLD AIR MOVES IN SUNDAY NIGHT INTO MONDAY. && .AVIATION /09Z WEDNESDAY THROUGH SUNDAY/... AS OF 1100 PM EST TUESDAY... HIGH PRESSURE WILL WEAKEN ACROSS THE REGION OVERNIGHT AHEAD OF A COLD FRONT APPROACHING FROM THE WEST. HOWEVER THE RIDGE WILL HANG ON LONG ENOUGH EAST OF THE BLUE RIDGE TO RESULT IN A BIT MORE FOG THAN EARLIER THOUGHT...WITH PERHAPS KDAN/KLYH DROPPING TO MVFR OR EVEN IFR AT TIMES IN FOG/STRATUS THROUGH DAYBREAK WEDNESDAY. THIS SUPPORTED BY THE LATEST NARRE ENSEMBLE AND HRRR WHICH KEEP AN AXIS OF FOG/LOW CLOUDS FROM KLYH TO KDAN OVER THE NEXT FEW HOURS. OTRW THE COLD FRONT WILL BRING INCREASING CHANCES OF SHOWERS AND AREAS OF MVFR CIGS TO LOCATIONS ALONG A KTNB-KBLF-KLWB LINE STARTING BETWEEN ROUGHLY 07-12Z/2-7AM EARLY WEDNESDAY. WHILE THE FRONT WILL CROSS THE REST OF THE REGION WEDNESDAY MORNING...IT WILL ENCOUNTER GENEROUS LINGERING DRY AIR IN THE WAKE OF DEPARTING HIGH PRESSURE. AT BEST...SCATTERED LOW END VFR CLOUD LAYERS MAY MAKE IT AS FAR EAST AS THE CREST OF THE BLUE RIDGE INCLUDING KBCB AND PERHAPS KROA. HOWEVER MOISTURE MAY BE ENOUGH UNDER THE RESULTANT UPSLOPE POST FRONTAL NW FLOW TO BRING A PERIOD OF IFR TO KBLF TOWARD DAYBREAK WEDNESDAY AND POSSIBLY KLWB. A FADING BAND OF SHOWERS ALSO COULD IMPACT KBLF/KLWB EARLY WEDNESDAY SO KEPT IN A VCSH MENTION THERE ONLY AT THIS POINT. VERY DRY AIR SPILLS IN FROM THE WEST WEDNESDAY AFTERNOON ALLOWING GOOD DRYING FROM ALOFT AS SEEN VIA LATEST NAM BUFKIT SOUNDINGS. THIS SHOULD TREND ALL SITES TOWARD VFR OVER THE WEST AFTER MIDDAY WEDNESDAY BUT GIVEN GRADIENT OF COLD ADVECTION AND UPSLOPE OVER THE NW...LOW CONFIDENCE ON SEEING CIGS GO VFR OR SCATTER OUT AT KBLF LATER IN THE AFTERNOON. THIS LOW LEVEL MOISTURE MAY GET TRAPPED UNDER THE INVERSION AT KBLF SO KEEPING IN A LOW END VFR TO HIGH LEVEL MVFR CIG THERE INTO WEDNESDAY EVENING. SURFACE WINDS ON WEDNESDAY WILL INCREASE FROM THE NORTHWEST IN THE 7 TO 12 KT RANGE WITH SOME GUSTS NEAR 20 KTS IN THE MOUNTAINS. EXTENDED DISCUSSION... AN UPPER LEVEL TROUGH WILL DEVELOP OVER THE EASTERN U.S. AND MAKE ITS WAY NORTHEAST DURING THE THURSDAY THROUGH SATURDAY TIME PERIOD. A WEAK UPPER DISTURBANCE ALONG THE LEADING EDGE OF THE ARCTIC AIR THURSDAY MAY LEAD TO SOME LIGHT PRECIPITATION INTO THURSDAY AFTERNOON WITH MVFR CIGS POSSIBLE ACROSS THE REGION. A GENERAL PATTERN OF HIGH PRESSURE SHOULD HELP KEEP MOST AREAS VFR THROUGH AT LEAST SATURDAY. THE EXCEPTION MAY BE SOME LATE NIGHT RIVER OR VALLEY FOG AND LINGERING UPSLOPE CLOUDS AT KBLF/KLWB. ON SUNDAY...A STRONG UPPER WAVE AND ASSOCIATED COLD FRONT IS EXPECTED TO MOVE INTO AND/OR THROUGH THE REGION. THIS MAY BRING A MIX OF SUB-VFR CONDITIONS AND A WINTRY MIX OF PRECIPITATION. CONFIDENCE IS LOW ON PRECIP TYPE. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...RAB NEAR TERM...RAB SHORT TERM...RCS LONG TERM...MBS AVIATION...DS/JH/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1115 PM EST TUE NOV 11 2014 .SYNOPSIS... HIGH PRESSURE WILL SHIFT EAST OF THE REGION OVERNIGHT WHILE A COLD FRONT ARRIVES FROM THE WEST. COLDER AIR WILL ARRIVE BEHIND THE FRONT WITH LIMITED CHANCES OF PRECIPITATION THROUGH SATURDAY. OUR NEXT CHANCE FOR A PRECIPITATION WILL BE SUNDAY INTO MONDAY OF NEXT WEEK WHEN A STRONG COLD FRONT MOVES THROUGH THE REGION. && .NEAR TERM /THROUGH WEDNESDAY/... AS OF 920 PM EST TUESDAY... NOT A LOT OF CHANGE TO THE GOING FORECAST OVERNIGHT WITH EVENING SOUNDINGS SHOWING LOTS OF DRY AIR IN PLACE AHEAD OF THE SURFACE COLD FRONT NOW CROSSING WEST/CENTRAL KY. AXIS OF LOW CLOUDS PRECEDING THE BOUNDARY NOW APPROACHING FAR SW VA AND SHOULD WORK INTO THE WESTERN SECTIONS ESPCLY AFTER MIDNIGHT PROVIDED THEY CAN OVERCOME THE DRY AIR ALOFT. MODELS ALSO STILL ON TRACK FOR A FEW LIGHT SHOWER BANDS TO REACH THE WESTERN SLOPES BY DAYBREAK BEFORE FADING. THUS LEFT IN LOW POPS FAR WEST WHILE PUSHING CLOUDS EAST A BIT QUICKER AS EXPECT THE FRONT TO BE NEAR THE BLUE RIDGE SHORTLY AFTER SUNRISE. WITH HIGHER DEWPOINT AIR LINGERING ALONG THE FAR EASTERN PERIMETER OF THE CWA...BEEFED UP FOG COVERAGE OVERNIGHT OUT EAST PER LATEST OB FROM FARMVILLE SHOWING DENSE FOG WHICH MAY DEVELOP INTO A FEW AREAS EAST OF HIGHWAY 29 SHORTLY. TEMPS A BIT TRICKY GIVEN QUICK FALLS IN THE VALLEYS UNDER CLEAR SKIES/LIGHT WINDS THIS EVENING...WHILE READINGS ARE STAYING MILD ON THE RIDGES WHERE A LIGHT BREEZE PERSISTS. THINK COMBO OF MORE CLOUDS WEST AND SOME CONTINUED MIXING LIKELY TO EVEN OUT TEMPS SOME OVERNIGHT MOUNTAINS. HOWEVER EXPECT MAY NEED TO GO COLDER IN SPOTS ACROSS THE PIEDMONT/FOOTHILLS...PER BETTER RADIATIONAL COOLING CONDITIONS LONGER OVERNIGHT. OTRW LOWS MOSTLY IN THE 40S EXCEPT 50S AT ELEVATION...WITH SOME 30S EAST AND WESTERN VALLEYS EARLY...BEFORE REBOUNDING LATE WITH THE ARRIVAL OF THE FRONT. PREVIOUS VALID DISCUSSION AS OF 200 PM EST TUESDAY... HIGH PRESSURE WILL SHIFT TO THE EAST TONIGHT WHILE A COLD FRONT ARRIVES IN THE WEST AROUND DAYBREAK WEDNESDAY. THE FRONT WILL ENCOUNTER PLENTY OF LINGERING DRY AIR FROM THE HIGH THAT IS OVER US TODAY. ASSOCIATED ISOLATED TO SCATTERED SHOWERS ARE EXPECTED TO MAKE VERY LIMITED HEADWAY INTO OUR REGION...AND BE CONFINED PRIMARILY TO SOUTHEAST WEST VIRGINIA...SOUTH INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA. AREAS EAST OF THE CREST OF THE BLUE RIDGE MAY SEE A BRIEF PERIOD OF ENHANCED CLOUD COVER THROUGH THE MORNING HOURS. NORTHWEST FLOW BEHIND THE FRONT WILL SQUELCH CLOUD COVER IN THE EAST BY THE AFTERNOON...AND THE AMOUNT ACROSS THE MOUNTAINS WILL DECLINE AS THE DAY PROGRESSES. LOW TEMPERATURES TONIGHT WILL REMAIN ON THE MILD SIDE FOR THIS TIME OF THE YEAR ON THE EAST SIDE OF THE COLD FRONT. A MIX OF LOW TO MID 40S IS FORECAST. ON WEDNESDAY...TEMPERATURES IN THE EAST WILL REMAIN MILD WITH LOWER 60S TO AROUND 70 EXPECTED FOR HIGHS. ACROSS THE MOUNTAINS...THE INFLUENCE OF SCATTERED SHOWERS AND MORE CLOUD COVER WILL KEEP HIGHS IN THE LOW TO MID 50S. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... AS OF 300 PM EDT VETERANS DAY... MODELS CONTINUE TO ADVERTISE COLD PUNCH OF ARCTIC ARRIVING THURSDAY...WITH LITTLE TO NO THREAT OF PRECIP. STILL LOOKS LIKE WAVE ALONG THE FRONT THAT SHIFTS OFF THE COAST MAY SLIDE MOISTURE BACK INTO THE PIEDMONT THURSDAY INTO THURSDAY EVENING BUT MOST OF THE DEEP MOISTURE STAYS EAST. EXPECT PATCHY LIGHT RAIN IN THE EAST...WITH ONLY 20 POPS. MEANWHILE...THE SFC FLOW TURNS NW AND COLDER AIR TRAVERSES THE REGION THURSDAY. SOME UPSLOPE SNOW SHOWERS/FLURRIES NOT OUT OF THE QUESTION LATE THURSDAY INTO LATE THURSDAY NIGHT...BUT BEST ENERGY STAYS NORTH. MAIN STORY WILL BE THE COLDER AIR...AND WITH SOME WIND EARLY FRIDAY MORNING WIND CHILLS COULD DROP INTO THE SINGLE DIGITS OVER THE HIGHER ELEVATIONS. ARCTIC HIGH BUILDS IN FROM THE WEST FRIDAY WITH SKIES CLEARING WHILE TEMPS ONLY MANAGE TO REACH THE 30S IN THE MOUNTAINS...EXCEPT 20S HIGHER TERRAIN WHILE THE PIEDMONT RISES INTO THE LOWER TO MID 40S. WITH THE HIGH MOVING OVERHEAD LATE FRIDAY NIGHT...LOW TEMPS WILL BE THE COLDEST OF THE FALL SEASON SO FAR...FEELING MORE LIKE JANUARY...WITH TEENS WEST TO LOWER 20S EAST. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 300 PM EST TUESDAY... MODELS HAVE THE SAME OVERALL FLAVOR THOUGH THE EXTENDED PERIOD WITH MAIN DIFFERENCES IN TIMING AND MAGNITUDE OF NEXT SHOT OF COLD AIR. SATURDAY IS LOOKING LIKE A DECENT START TO THE WEEKEND. WHILE TEMPS WILL CONTINUE TO BE WELL BELOW NORMAL...THE UPPER FLOW WILL FLATTEN OUT A BIT AND WE WILL START TO SEE SOME WARMER AIR BEGINNING TO MOVE AS THE SURFACE HIGH SLIDES TO OUR EAST AND WINDS BECOME SOUTHERLY. THIS WILL BE A SHORT REPRIEVE AS THE NEXT UPPER SHORT WAVE SHARPENS THE FLOW AGAIN AND THE NEXT SHOT OF COLD AIR MOVES IN BEHIND A COLD FRONT ON SUNDAY. GENERALLY EXPECTING PTYPE TO BE LIQUID ON SUNDAY... TRANSITIONING TO SNOW SHOWERS SUNDAY NIGHT INTO MONDAY. IT APPEARS THAT PROLONGED NW FLOW WILL KEEP SNOW SHOWERS GOING FOR THE HIGHER ELEVATIONS WEST OF THE BLUE RIDGE THROUGH THE FIRST PART OF NEXT WEEK WITH SOME ACCUMULATIONS POSSIBLE. LOWER ELEVATIONS WILL HAVE DIURNAL PTYPE CHANGES WHICH SHOULD DISCOURAGE SNOW FROM STICKING AROUND DURING THE DAYLIGHT HOURS. IT ALSO LOOKS TO BE BLUSTERY AS THE COLD AIR MOVES IN SUNDAY NIGHT INTO MONDAY. && .AVIATION /04Z WEDNESDAY THROUGH SUNDAY/... AS OF 1100 PM EST TUESDAY... HIGH PRESSURE WILL WEAKEN ACROSS THE REGION OVERNIGHT AHEAD OF A COLD FRONT APPROACHING FROM THE WEST. HOWEVER THE RIDGE WILL HANG ON LONG ENOUGH EAST OF THE BLUE RIDGE TO RESULT IN A BIT MORE FOG THAN EARLIER THOUGHT...WITH PERHAPS KDAN/KLYH DROPPING TO MVFR OR EVEN IFR AT TIMES IN FOG/STRATUS THROUGH DAYBREAK WEDNESDAY. THIS SUPPORTED BY THE LASTEST NARRE ENSEMBLE AND HRRR WHICH KEEP AN AXIS OF FOG/LOW CLOUDS FROM KLYH TO KDAN OVER THE NEXT FEW HOURS. OTRW THE COLD FRONT WILL BRING INCREASING CHANCES OF SHOWERS AND AREAS OF MVFR CIGS TO LOCATIONS ALONG A KTNB-KBLF-KLWB LINE STARTING BETWEEN ROUGHLY 07-12Z/2-7AM EARLY WEDNESDAY. WHILE THE FRONT WILL CROSS THE REST OF THE REGION WEDNESDAY MORNING...IT WILL ENCOUNTER GENEROUS LINGERING DRY AIR IN THE WAKE OF DEPARTING HIGH PRESSURE. AT BEST...SCATTERED LOW END VFR CLOUD LAYERS MAY MAKE IT AS FAR EAST AS THE CREST OF THE BLUE RIDGE INCLUDING KBCB AND PERHAPS KROA. HOWEVER MOISTURE MAY BE ENOUGH UNDER THE RESULTANT UPSLOPE POST FRONTAL NW FLOW TO BRING A PERIOD OF IFR TO KBLF TOWARD DAYBREAK WEDNESDAY AND POSSIBLY KLWB. A FADING BAND OF SHOWERS ALSO COULD IMPACT KBLF/KLWB EARLY WEDNESDAY SO KEPT IN A VCSH MENTION THERE ONLY AT THIS POINT. VERY DRY AIR SPILLS IN FROM THE WEST WEDNESDAY AFTERNOON ALLOWING GOOD DRYING FROM ALOFT AS SEEN VIA LATEST NAM BUFKIT SOUNDINGS. THIS SHOULD TREND ALL SITES TOWARD VFR OVER THE WEST AFTER MIDDAY WEDNESDAY BUT GIVEN GRADIENT OF COLD ADVECTION AND UPSLOPE OVER THE NW...LOW CONFIDENCE ON SEEING CIGS GO VFR OR SCATTER OUT AT KBLF LATER IN THE AFTERNOON. THIS LOW LEVEL MOISTURE MAY GET TRAPPED UNDER THE INVERSION AT KBLF SO KEEPING IN A LOW END VFR TO HIGH LEVEL MVFR CIG THERE INTO WEDNESDAY EVENING. SURFACE WINDS ON WEDNESDAY WILL INCREASE FROM THE NORTHWEST IN THE 7 TO 12 KT RANGE WITH SOME GUSTS NEAR 20 KTS IN THE MOUNTAINS. EXTENDED DISCUSSION... AN UPPER LEVEL TROUGH WILL DEVELOP OVER THE EASTERN U.S. AND MAKE ITS WAY NORTHEAST DURING THE THURSDAY THROUGH SATURDAY TIME PERIOD. A WEAK UPPER DISTURBANCE ALONG THE LEADING EDGE OF THE ARCTIC AIR THURSDAY MAY LEAD TO SOME LIGHT PRECIPITATION INTO THURSDAY AFTERNOON WITH MVFR CIGS POSSIBLE ACROSS THE REGION. A GENERAL PATTERN OF HIGH PRESSURE SHOULD HELP KEEP MOST AREAS VFR THROUGH AT LEAST SATURDAY. THE EXCEPTION MAY BE SOME LATE NIGHT RIVER OR VALLEY FOG AND LINGERING UPSLOPE CLOUDS AT KBLF/KLWB. ON SUNDAY...A STRONG UPPER WAVE AND ASSOCIATED COLD FRONT IS EXPECTED TO MOVE INTO AND/OR THROUGH THE REGION. THIS MAY BRING A MIX OF SUB-VFR CONDITIONS AND A WINTRY MIX OF PRECIPITATION. CONFIDENCE IS LOW ON PRECIP TYPE. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...WP NEAR TERM...DS/JH SHORT TERM...WP LONG TERM...MBS AVIATION...DS/JH
AREA FORECAST DISCUSSION
NWS ALBANY NY
1243 AM EST FRI NOV 14 2014 .SYNOPSIS... FIRST MEASURABLE SNOWFALL FOR MUCH OF THE FORECAST AREA EXPECTED TONIGHT WITH ACCUMULATIONS MAINLY ON GRASSY SURFACES. SNOW IS EXPECTED TO COME TO AN END BEFORE THE MORNING COMMUTE. IN THE MEANTIME...LAKE ENHANCED SNOW WILL CONTINUE INTO THE WESTERN ADIRONDACKS. A REINFORCING SHOT OF COLD AIR WILL TAKE HOLD FRIDAY AND LAST INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1215 AM...A BAND OF STEADY LIGHT SNOW IS PROGRESSING EASTWARD ACROSS THE GREATER CAPITAL DISTRICT AND POINTS SOUTH AND EAST. LATEST LOCAL HRRR MODEL AND HIRESWRF MODEL RUN UPDATES HAVE BEEN CONSISTENT WITH SLIGHTLY MORE QPF ACROSS THE SOUTHERN REGIONS WHERE SNOWFALL TOTALS HAVE BEEN INCREASED SLIGHTLY IN THE HIGHEST TERRAIN ACROSS THE SOUTHERN BERKSHIRES INTO THE NORTHERN LITCHFIELD HILLS WILL RANGE BETWEEN ONE TO TWO INCHES WITH ISOLATED AREAS UP TO THREE INCHES POSSIBLE BY EARLY FRIDAY MORNING. THE PRECIPITATION MAINLY IN THE FORM OF SNOW IS EXPECTED TO END BEFORE THE MORNING COMMUTE...BY AROUND 07Z ACROSS OUR WESTERN NEW ENGLAND COUNTIES. GENERALLY LOOKING AT LESS THAN AN INCH BELOW 1000 FEET WITH 1 TO 2 INCHES ABOVE 1000 FEET AND FOR LITCHFIELD COUNTY. LAKE ENHANCED SNOW WILL CONTINUE INTO THE WESTERN ADIRONDACKS TONIGHT AS THE SOUTHWESTERLY FLOW CONTINUES AHEAD OF APPROACHING TROUGH. AMOUNTS ARE GENERALLY EXPECTED TO BE LIGHT ACROSS THIS AREA MAINLY UNDER 2 INCHES. TEMPERATURES ARE EXPECTED TO DROPPED INTO MAINLY THE 20S OVERNIGHT WITH SOME BLACK ICE POSSIBLE LATE TONIGHT AS ANY MOISTURE WILL FREEZE ON UNTREATED SURFACES. && .SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/... FLOW ACROSS REGION WILL SHIFT TO THE NORTHWEST AS THE LOW MOVES NORTHEAST AWAY FROM THE REGION. ALOFT THE UPPER TROUGH AXIS WILL SWING THROUGH MAINLY DURING THE MORNING AND CYCLONIC WILL SET UP ACROSS THE REGION. COLDER AIR MASS WILL BLANKET REGION WITH 850 MB TEMPERATURES DROPPING TO -10 TO -12 DEGREES CELSIUS ACROSS THE FORECAST AREA. WITH THIS COLD AIR MOVING ACROSS THE GREAT LAKES LAKE EFFECT CLOUDS AND SHOWERS IMPACTING PORTIONS OF THE FORECAST AREA...MAINLY THE WESTERN MOHAWK VALLEY INTO THE EASTERN CATSKILLS. THE LAKE EFFECT WILL DIMINISH SATURDAY AND SHOULD COME TO AN END BY SATURDAY NIGHT AS RIDGING BUILDS IN. THE RIDGE`S VISIT WILL BE BRIEF AS IT MOVES QUICKLY OFFSHORE SATURDAY NIGHT AHEAD OF THE NEXT SYSTEM. COLD WITH TEMPERATURES RUNNING 10 TO 15 DEGREES BELOW NORMAL. && .LONG TERM /SUNDAY THROUGH THURSDAY/... A VERY ACTIVE AND CHILLY PATTERN SETTING UP FOR THE LONG TERM PERIOD AS A VIGOROUS UPPER TROUGH /POLAR VORTEX/ DIVES SOUTHWARD AND EASTWARD OF THE CONTINENTAL DIVIDE. MONDAY...PLENTY OF MODEL DISCREPANCIES REMAIN AS THE ECMWF REMAINS ON THE WARMER SIDE OF THE GUIDANCE ENVELOPE WITH THE GGEM/GFS ON THE COLDER SIDE. IN ADDITION...THE GGEM IS STRONGER WITH THE COASTAL WAVE REFLECTION AS OPPOSED TO THE FLATTER AND FASTER WAVE OF THE GFS WITH THE ECMWF SOMEWHAT IN THE MIDDLE. AT THIS TIME...AND PER COLLABORATION WITH WPC...WE WILL LEAN TOWARD THE MORE STABLE ECMWF. THIS WOULD RESULT THE CHANCE FOR ACCUMULATING SNOW FOR THE HIGHER TERRAIN NORTH AND WEST OF ALBANY WITH MAINLY RAIN /PERHAPS A LITTLE SNOW MIX/ SOUTH AND EAST OF ALBANY. FOR NOW...WE WILL HAVE HIGH CHANCE POPS UNDER A CLOUDY SKY. WPC GUIDANCE TEMPS ARE A GREAT COMPROMISE WITH LEANING TOWARD A SLIGHTLY COLDER SOLUTION DUE TO WET BULB PROCESS. MONDAY NIGHT THROUGH WEDNESDAY...WHAT WAVE DOES DEVELOP WILL QUICKLY TRACK TO THE NORTHEAST MONDAY EVENING. COLD AIR ADVECTION AND DEEP CYCLONIC FLOW WILL RESULT IN LAKE EFFECT ACTIVITY DEVELOPING DOWNWIND OF LAKE ONTARIO WHICH WILL BE THE MAIN WEATHER STORY FOR THE REMAINDER OF THE LONG TERM PERIOD. OTHERWISE...BELOW NORMAL TEMPERATURES AS H850 TEMPS ARE AT OR BELOW -10C AND MAINLY CLOUD COVERAGE INTO THE TERRAIN WITH UPSLOPE CONDITIONS. MORE CLEARING WILL TAKE PLACE DOWNWIND OF THE TERRAIN...ESPECIALLY IN THE MID HUDSON VALLEY. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... THE COMBINATION OF AN UPPER LEVEL TROUGH APPROACHING FROM THE WEST...AND A WEAK LOW PRESSURE SYSTEM OFF THE EAST COAST...HAS ALLOWED FOR PERIODS OF LIGHT SNOW TO DEVELOP ACROSS KALB/KPOU AND KPSF. THE MAIN BAND OF PRECIP...MAINLY IN THE FORM OF SNOW...CONTINUES TO SLOWLY MOVE E/SE...WITH THE MAIN FOCUS BEGINNING TO SHIFT MAINLY EAST OF THE HUDSON RIVER. WIDESPREAD IFR VSBYS AND SOME CIGS ARE OCCURRING WITHIN THIS BAND. THE BAND REMAINS S AND E OF KGFL...WHERE MAINLY VFR CONDITIONS ARE EXPECTED THROUGH DAYBREAK. OVER THE NEXT 1-3 HOURS...WE EXPECT IFR CONDITIONS TO GRADUALLY IMPROVE TO MVFR AT KALB...AS THE SNOW TAPERS OFF TO FLURRIES. AT KPSF AND KPOU...PERIODS OF SNOW MAY PERSIST THROUGH AROUND 08Z/FRI...SO MAINLY IFR CONDITIONS ARE EXPECTED DURING THIS TIME...BEFORE IMPROVING TO MVFR AFTER 08Z/FRI. AFTER 09Z...MVFR/VFR CONDITIONS ARE EXPECTED...MAINLY DUE TO CIGS. SOME SNOW SHOWERS OR FLURRIES MAY REDEVELOP AT KGFL...AND COULD OCCASIONALLY DRIFT INTO KALB AND KPSF THROUGH MID MORNING. THIS COULD ALLOW FOR SOME BRIEF REDUCTIONS TO MVFR OR IFR. OTHERWISE...MAINLY VFR CONDITIONS ARE EXPECTED THROUGH 06Z/SAT. LIGHT/VARIABLE WINDS WILL TREND INTO THE WEST TO NORTHWEST BY SUNRISE AT 5-10 KT. W/NW WINDS WILL THEN INCREASE SLIGHTLY TO 8-12 KT BY MID MORNING...WITH SOME GUSTS DEVELOPING IN THE 15-20 KT RANGE...PERHAPS A BIT HIGHER AT KALB AND KPSF. NW WINDS SHOULD THEN DECREASE TO LESS THAN 8 KT 1-2 HOURS AFTER SUNSET. OUTLOOK... FRI NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. SAT-SAT NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUN: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN. SUN NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN. MON: HIGH OPERATIONAL IMPACT. LIKELY RA...SN. MON NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... NO HYDROLOGIC PROBLEMS ARE EXPECTED INTO EARLY NEXT WEEK. MAINLY LIGHT AND FROZEN PRECIPITATION INTO THE WEEKEND. A STORM SYSTEM WILL IMPACT THE REGION TO END THE WEEKEND AND START THE NEW WORK WEEK. THERE IS MUCH UNCERTAINTY WITH THE SYSTEM...REFER TO THE LONG TERM DISCUSSION FOR DETAILS. 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...IAA NEAR TERM...LFM/BGM/11 SHORT TERM...IAA LONG TERM...BGM AVIATION...ELH/KL HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1224 AM EST FRI NOV 14 2014 .SYNOPSIS... FIRST MEASURABLE SNOWFALL FOR MUCH OF THE FORECAST AREA EXPECTED TONIGHT WITH ACCUMULATIONS MAINLY ON GRASSY SURFACES. SNOW IS EXPECTED TO COME TO AN END BEFORE THE MORNING COMMUTE. IN THE MEANTIME...LAKE ENHANCED SNOW WILL CONTINUE INTO THE WESTERN ADIRONDACKS. A REINFORCING SHOT OF COLD AIR WILL TAKE HOLD FRIDAY AND LAST INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1215 AM...A BAND OF STEADY LIGHT SNOW IS PROGRESSING EASTWARD ACROSS THE GREATER CAPITAL DISTRICT AND POINTS SOUTH AND EAST. LATEST LOCAL HRRR MODEL AND HIRESWRF MODEL RUN UPDATES HAVE BEEN CONSISTENT WITH SLIGHTLY MORE QPF ACROSS THE SOUTHERN REGIONS WHERE SNOWFALL TOTALS HAVE BEEN INCREASED SLIGHTLY IN THE HIGHEST TERRAIN ACROSS THE SOUTHERN BERKSHIRES INTO THE NORTHERN LITCHFIELD HILLS WILL RANGE BETWEEN ONE TO TWO INCHES WITH ISOLATED AREAS UP TO THREE INCHES POSSIBLE BY EARLY FRIDAY MORNING. THE PRECIPITATION MAINLY IN THE FORM OF SNOW IS EXPECTED TO END BEFORE THE MORNING COMMUTE...BY AROUND 07Z ACROSS OUR WESTERN NEW ENGLAND COUNTIES. GENERALLY LOOKING AT LESS THAN AN INCH BELOW 1000 FEET WITH 1 TO 2 INCHES ABOVE 1000 FEET AND FOR LITCHFIELD COUNTY. LAKE ENHANCED SNOW WILL CONTINUE INTO THE WESTERN ADIRONDACKS TONIGHT AS THE SOUTHWESTERLY FLOW CONTINUES AHEAD OF APPROACHING TROUGH. AMOUNTS ARE GENERALLY EXPECTED TO BE LIGHT ACROSS THIS AREA MAINLY UNDER 2 INCHES. TEMPERATURES ARE EXPECTED TO DROPPED INTO MAINLY THE 20S OVERNIGHT WITH SOME BLACK ICE POSSIBLE LATE TONIGHT AS ANY MOISTURE WILL FREEZE ON UNTREATED SURFACES. && .SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/... FLOW ACROSS REGION WILL SHIFT TO THE NORTHWEST AS THE LOW MOVES NORTHEAST AWAY FROM THE REGION. ALOFT THE UPPER TROUGH AXIS WILL SWING THROUGH MAINLY DURING THE MORNING AND CYCLONIC WILL SET UP ACROSS THE REGION. COLDER AIR MASS WILL BLANKET REGION WITH 850 MB TEMPERATURES DROPPING TO -10 TO -12 DEGREES CELSIUS ACROSS THE FORECAST AREA. WITH THIS COLD AIR MOVING ACROSS THE GREAT LAKES LAKE EFFECT CLOUDS AND SHOWERS IMPACTING PORTIONS OF THE FORECAST AREA...MAINLY THE WESTERN MOHAWK VALLEY INTO THE EASTERN CATSKILLS. THE LAKE EFFECT WILL DIMINISH SATURDAY AND SHOULD COME TO AN END BY SATURDAY NIGHT AS RIDGING BUILDS IN. THE RIDGE`S VISIT WILL BE BRIEF AS IT MOVES QUICKLY OFFSHORE SATURDAY NIGHT AHEAD OF THE NEXT SYSTEM. COLD WITH TEMPERATURES RUNNING 10 TO 15 DEGREES BELOW NORMAL. && .LONG TERM /SUNDAY THROUGH THURSDAY/... A VERY ACTIVE AND CHILLY PATTERN SETTING UP FOR THE LONG TERM PERIOD AS A VIGOROUS UPPER TROUGH /POLAR VORTEX/ DIVES SOUTHWARD AND EASTWARD OF THE CONTINENTAL DIVIDE. MONDAY...PLENTY OF MODEL DISCREPANCIES REMAIN AS THE ECMWF REMAINS ON THE WARMER SIDE OF THE GUIDANCE ENVELOPE WITH THE GGEM/GFS ON THE COLDER SIDE. IN ADDITION...THE GGEM IS STRONGER WITH THE COASTAL WAVE REFLECTION AS OPPOSED TO THE FLATTER AND FASTER WAVE OF THE GFS WITH THE ECMWF SOMEWHAT IN THE MIDDLE. AT THIS TIME...AND PER COLLABORATION WITH WPC...WE WILL LEAN TOWARD THE MORE STABLE ECMWF. THIS WOULD RESULT THE CHANCE FOR ACCUMULATING SNOW FOR THE HIGHER TERRAIN NORTH AND WEST OF ALBANY WITH MAINLY RAIN /PERHAPS A LITTLE SNOW MIX/ SOUTH AND EAST OF ALBANY. FOR NOW...WE WILL HAVE HIGH CHANCE POPS UNDER A CLOUDY SKY. WPC GUIDANCE TEMPS ARE A GREAT COMPROMISE WITH LEANING TOWARD A SLIGHTLY COLDER SOLUTION DUE TO WET BULB PROCESS. MONDAY NIGHT THROUGH WEDNESDAY...WHAT WAVE DOES DEVELOP WILL QUICKLY TRACK TO THE NORTHEAST MONDAY EVENING. COLD AIR ADVECTION AND DEEP CYCLONIC FLOW WILL RESULT IN LAKE EFFECT ACTIVITY DEVELOPING DOWNWIND OF LAKE ONTARIO WHICH WILL BE THE MAIN WEATHER STORY FOR THE REMAINDER OF THE LONG TERM PERIOD. OTHERWISE...BELOW NORMAL TEMPERATURES AS H850 TEMPS ARE AT OR BELOW -10C AND MAINLY CLOUD COVERAGE INTO THE TERRAIN WITH UPSLOPE CONDITIONS. MORE CLEARING WILL TAKE PLACE DOWNWIND OF THE TERRAIN...ESPECIALLY IN THE MID HUDSON VALLEY. && .AVIATION /05Z FRIDAY THROUGH TUESDAY/... PERIOD OF LIGHT WINTRY MIXTURE CHANGING TO MAINLY SNOW TONIGHT FOR TAF SITES. THE INITIAL VFR CONDITIONS WILL GRADUALLY DETERIORATE TO MVFR LATER THIS EVENING. THERE COULD BE A PERIOD OF IFR CONDITIONS AT KPOU AS BANDED PRECIP MAY LIMIT BOTH VIS AND CIGS. OVERNIGHT...THE COASTAL SYSTEM WILL RAPIDLY PULL AWAY AS IMPROVING CONDITIONS WILL OCCUR WITH RESPECT TO DIMINISHING SNOW AND IMPROVING VISIBILITIES. HOWEVER...CIGS WILL REMAIN AT OR WITH MVFR RANGE THE REMAINDER OF THE NIGHT. DURING FRIDAY...WEST-NORTHWEST WINDS WILL INCREASE WHICH WILL ASSIST WITH CIGS BREAKING UP TO VFR CONDITIONS. HOWEVER...UPSLOPE CONDITIONS FOR KPSF MAY HOLD ONTO THE BKN CIGS A BIT LONGER. OUTLOOK... FRI NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. SAT-SAT NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUN: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN. SUN NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN. MON: HIGH OPERATIONAL IMPACT. LIKELY RA...SN. MON NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... NO HYDROLOGIC PROBLEMS ARE EXPECTED INTO EARLY NEXT WEEK. MAINLY LIGHT AND FROZEN PRECIPITATION INTO THE WEEKEND. A STORM SYSTEM WILL IMPACT THE REGION TO END THE WEEKEND AND START THE NEW WORK WEEK. THERE IS MUCH UNCERTAINTY WITH THE SYSTEM...REFER TO THE LONG TERM DISCUSSION FOR DETAILS. 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...IAA NEAR TERM...LFM/BGM/11 SHORT TERM...IAA LONG TERM...BGM AVIATION...ELH HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1205 AM EST Fri Nov 14 2014 ...Updated Aviation Discussion... ...Forecast Update... Issued at 930 PM EST Thu Nov 13 2014 Have some snow flurries at times passing through the region. RUC soundings indicate a narrow saturated layer around 5 kft at around -14C. This layer is generating the flurries that are falling into a fairly dry layer underneath. That same RUC sounding indicates the layer could stick around a little longer than in the previous forecast so have extended the timing for flurries to at least 09Z. Otherwise, the rest of the forecast is on track for lows in the lower 20s tonight. .SHORT TERM (Now through Friday Night)... Issued at 300 PM EST Thu Nov 13 2014 We`ll continue to see flurry activity across the region late this afternoon and evening as a cold Arctic airmass continues to settle into the Midwest squeezing all available moisture out of the atmosphere. Low clouds look to stick around through at least midnight and then begin to thin from west to east during the pre-dawn hours. This being the case, we could see a late night drop off in temps as those clouds become scattered in nature. This should result in low temps in the lower 20s tonight with a few upper teens possible in sheltered areas. Expect partly cloudy skies Friday as sfc high pressure settles into the region becoming centered over the Ohio Valley Fri night. This will result in high temps Friday in the mid 30s with low temps Friday night bottoming out in the upper teens and lower 20s. Ideal rad cooling conditions will exist for Friday night, so wouldn`t be surprised to see some mid teens for lows. .LONG TERM (Saturday through Thursday)... Issued at 330 AM EST Thu Nov 13 2014 ...Some Snow Accumulations Possible Sunday into Monday... The main forecast challenge will be snow chances this weekend into Monday. The First Snow Chance... Our first chance at a light snow will come Sat night into Sun morning as a shortwave upper level trough pushes through the upper Midwest and a weak frontal boundary attempts to organize near the TN Valley. These two features never really look to become well phased so it looks like we`ll remain in between systems to our north and south Sat night into Sun morning. A weak plume of moisture over our region looks to result in some light rain or rain/snow mix changing over to all light snow sat night with maximum accumulations around a half inch. Temps will warm into the upper 30s to around 40 Sun afternoon causing any remaining precip to change over to light rain and causing any light snow accums to melt. The Second Snow Chance... A better chance for snow over the region will arrive for Sun night into Monday as a shortwave upper trough ejects out of the SW CONUS. This wave will strengthen the weak sfc boundary located to our south and pull up plentiful Gulf moisture into the Ohio Valley. As typical with these overrunning precip events, a number of model solns exists, each with differing depictions of storm track, warm nose strength, and depth of the shallow cold air mass close to the sfc. The 12Z runs from today still mostly put portions of central KY under a threat for accumulating snows Sun night into Mon morning. The ECMWF soln is farthest NW and would result in a threat for accumulating snow over southern Indiana as well. The 12Z op GFS would indicate a farther SE track shifting the main snow threat to south central and east central KY. Also new with this model run are more robust QPF fields from the GEM and ECMWF. This being said, feel that a solid 1-3 inches of snowfall will be possible across a portion of the Ohio Valley Sun night into Mon morning. Potentially higher amounts of snowfall would be possible if the more robust QPF fields pan out. For our latest thinking on best area for accumulating snow and some preliminary snowfall amounts, see weather.gov/lmk. The Monday morning commute has the potential to be negatively impacted by this snowfall. The Rest of the Week... The rest of the week looks unseasonably cold with highs limited to the 30s through Wed...potentially colder if snow accums can be achieved Sun night/Mon morning. Low temps will be quite chilly in the teens for mid week. && .AVIATION (06Z TAF Update)... Updated at 1205 AM EST Fri Nov 14 2014 Stratus shield that has covered the Ohio Valley the last couple days is finally showing some breaks during the evening hours. Where there is cloud, we have seen intermittent very light snow, but not really enough to call it flurries nor enough to show up in observations. Will carry VFR ceilings across the board through the night. Can`t rule out a brief drop into high-end MVFR, but sufficiently low clouds haven`t stuck around long enough in any location to develop a ceiling. Will once again go out on a limb and show the clouds scattering out early to mid-morning as the nearly saturated layer around 4000 ft AGL becomes shallower. However, we could see ceilings hold in until early afternoon when the 850mb thermal trof finally starts to lift out. Will keep scattered strato-cu until sunset, when daytime heating is lost. NW winds less than 10 kt through the day, then light and variable after dark. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ Update.........RJS Short Term.....AMS Long Term......EER/AMS Aviation.......RAS
AREA FORECAST DISCUSSION
NWS GRAY ME
110 AM EST FRI NOV 14 2014 .SYNOPSIS... LOW PRESSURE WILL OFF THE MID ATLANTIC COAST WILL MOVE NORTHEASTWARD TONIGHT. THE LOW IS EXPECTED TO MOVE INTO THE CANADIAN MARITIMES FRIDAY. HIGH PRESSURE WILL MOVE IN FOR THE WEEKEND. LOW PRESSURE WILL MOVE INTO THE AREA MONDAY AND TUESDAY BRINGING RAIN AND SNOW. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... 1 AM UPDATE...LITTLE CHANGE TO THE GOING FORECAST. HAVE BLENDED FORECAST WITH LATEST HRRR TO ALLOW FOR SHARPER POP TIMING. SNOW IS STICKING TO GRASSY SURFACES MOST AREAS NOW...AND MAY BEGIN TO STICK TO SECONDARY ROADS SHORTLY. 935PM UPDATE: ATTM LIGHT SNOW HAD SPREAD ACROSS NH AND WESTERN AND SOUTHERN MAINE AS SCHEDULED. A FEW AREAS OVER SRN MAINE STARTED AS RAIN OR A MIX. THE CURRENT FORECAST LOOKS GOOD WITH ONLY MINOR TWEAKS. PREV DISC: MAIN CONCERN FOR THIS FORECAST REVOLVES AROUND DEVELOPING FRONTAL WAVE OVER THE MID ATLANTIC. THIS FEATURE WILL FEED OFF THE FRESHLY REINFORCED BAROCLINIC ZONE OFF THE COAST...WITH SFC LOW PRES EXPECTED TO RAPIDLY DEVELOP AS IT PASSES CAPE COD. IN GENERAL EXPECT A 2 TO 3 INCH SNWFL FOR COASTAL AREAS TO THE FOOTHILLS...WITH ISOLATED AMOUNTS TO 4 INCHES POSSIBLE. THE FORECAST IS A DIFFICULT ONE...WITH MIXED SIGNALS IN THE MODEL GUIDANCE. ONE THING THAT IS CONSISTENT AMONG VARIOUS PIECES OF GUIDANCE IS QPF. NWP HAS ABOUT 0.30 INCHES LIQUID JUST INLAND FROM THE COAST...DROPPING TO ABOUT 0.20 INCHES AT THE FOOTHILLS. THIS SUPPORTS A 2 TO 3 INCH SNWFL NICELY...AND DEPENDING ON INTENSITY AND RATIOS UP TO 4. A COUPLE CAUTION FLAGS ARE NOTED THOUGH. ONE IS THAT ISENTROPIC FORCING IS WEAK. WINDS ARE GENERALLY PARALLEL TO PRES SURFACES UNTIL YOU GET WELL OUT TO SEA. THIS WILL MEAN VERY LITTLE PCPN FROM WAA PROCESSES. ANOTHER IS THAT TO THE NW SOME DRY AIR TRIES TO CREEP INTO THE COLUMN. AS LIFT IS DISPLACED HIGHER UP IN THE ATMOSPHERE ON THE COLD SIDE OF THE SYSTEM...THE GENERATION OF PCPN MAY BE POOR OR NONEXISTENT. FOR THESE REASON EXPECT THAT THE WRN EDGE TO SNWFL MAY BE SHARPER THAN THIS CURRENT FORECAST. THAT BEING SAID...THERE ARE PLENTY OF POSITIVES FOR SNWFL AS WELL. MID LEVELS WILL BE DEEPENING QUICKLY AROUND 12Z...AND AS THESE CENTERS CLOSE OFF ENHANCED FRONTOGENESIS CAN BE EXPECTED ON THE COLD SIDE. THIS IS PRIMARY MECHANISM FOR FRONTOGENESIS IN THIS SYSTEM...AS STATED EARLIER WAA WILL BE WEAK. CROSS SECTION ANALYSIS THRU KPWM PAINTS A FAVORABLE PICTURE TOO. AROUND 600 MB THERE IS AN AREA OF -EPV ON ALL MODEL GUIDANCE...SHOWING THAT SOME INSTABILITY ALOFT IS LIKELY. BENEATH THIS FEATURE...THE INCREASING FRONTOGENESIS WILL PROVIDE AT LEAST MODEST LIFT THRU A SATURATED SN GROWTH ZONE. THE COMBINATION OF WHICH IS FAVORABLE FOR BANDED SNWFL STRUCTURES. SOUNDING ANALYSIS OF THE NAM FORECASTS SHOW A POTENTIAL INTERESTING FEATURE TO BE CONCERNED WITH. ABOVE 600 MB THE LAST SEVERAL NAM RUNS HAVE FEATURED A MAUL...OR MOIST ABSOLUTELY UNSTABLE LAYER. IF LIFT CAN TAP THIS...WHICH IS LIKELY WHERE MODELS ARE PLACING THE GREATEST -EPV...SNWFL RATES COULD BE AT LEAST BRIEFLY INTENSE. FOR THIS REASON THE ISOLATED AMOUNT AROUND 4 INCHES WAS INCLUDED. FINALLY...GIVEN THAT MOST OF THE SNWFL IS EXPECTED TO OCCUR AFTER 09Z AND BEFORE 15Z...I ANTICIPATE THAT THERE WILL BE PROBLEMS AROUND THE MORNING COMMUTE. FOR MANY OF THESE AREAS IT WILL BE THE FIRST ACCUMULATING SNWFL GREATER THAN 1 INCH. THIS YEAR AFTER YEAR IS SHOWN TO CAUSE TRAVEL ISSUES. SO I HAVE ISSUED A WINTER WX ADVISORY FOR COASTAL AND COASTAL PLAIN ZONES HIGHLIGHTING THAT MORNING COMMUTE IMPACT. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... SNWFL WILL BE COMING TO AN END RATHER QUICKLY FROM W TO E MID MORNING FRI. TROF AXIS ALOFT HOWEVER WON/T CROSS THE AREA UNTIL AFTERNOON. LINGERING MOISTURE AND INSTABILITY WITH THIS FEATURE SHOULD ALLOW FOR AT LEAST SOME SCT SHSN...ESPECIALLY FOR THE HIGHER TERRAIN. WHILE NOT EXPECTED FULL BLOWN ARCTIC SQUALLS...THE BTV SNOW SQUALL PARAMETER I THINK IS DOING A GOOD JOB OF HIGHLIGHTING THAT INSTABILITY. SHOULD SEE ENOUGH DOWNSLOPING TO MITIGATE THE CAA OCCURRING ACROSS THE CWFA. HIGH TEMPS WILL BE BELOW NORMAL...BUT NOT DRASTICALLY SO. SFC HIGH PRES WILL STILL BE BUILDING IN FRI NIGHT...SO FEEL THAT MOS GUIDANCE IS RUSHING THE COLDER TEMPS FOR THAT NEXT MORNING. WENT ABOVE THE MAV/MET FOR MIN TEMPS. && .LONG TERM /SATURDAY THROUGH THURSDAY/... THE MODELS ARE IN GENERAL AGREEMENT ON THE LONG WAVE PATTERN WELL INTO NEXT WEEK. THE WESTERN RIDGE/EASTERN TROUGH PATTERN ADVERTISED BY THE MODELS WILL PROVIDE BELOW AVERAGE TEMPERATURES THROUGH THE EXTENDED PERIOD. WE BEGIN THE PERIOD WITH WEAK RIDGING SURFACE AND ALOFT FOR A FAIR BUT COLD DAY ON SATURDAY. THE RIDGE SLIDES OFFSHORE FOR SUNDAY WITH A SOMEWHAT MILDER RETURN FLOW...AND A BROAD SOUTHWEST FLOW ALOFT AS WE WAIT FOR THE UPPER TROUGH TO RELOAD. WARM AIR ADVECTION WILL PRODUCE CLOUDS ALONG WITH THE CHANCE FOR A FEW RAIN OR SNOW SHOWERS DEPENDENT LARGELY ON BOUNDARY LAYER TEMPERATURES. BY MONDAY...THE TROUGH HAS RELOADED WITH LEADING IMPULSE GIVING RISE TO AN ASSOCIATED SURFACE LOW THAT RIDES NORTHEAST ALONG THE COAST. IT SHOULD BE NOTED THAT THE MODEL TREND OVER THE PAST DAY HAS BEEN SLOWER...WEAKER...COLDER... AND FURTHER OFFSHORE WITH THIS DISTURBANCE. AT THIS POINT...PRECIPITATION LOOKS LIKE A RAIN SNOW MIX...WITH BEST CHANCE FOR ANY ACCUMULATING SNOW INLAND. IN THE WAKE OF THIS SYSTEM...ANOTHER COLD FRONT AND EVEN COLDER AIR WILL ARRIVE FOR TUESDAY AND THE MIDWEEK PERIOD. THE WEST-SOUTHWEST TRAJECTORY OFF OF LAKE ONTARIO SHOULD SPREAD LAKE EFFECT PLUME INTO WESTERN AND NORTHERN SECTIONS OF THE FORECAST AREA LATE TUESDAY NIGHT AND WEDNESDAY WITH CLOUDS AND A FEW SNOW SHOWERS LIKELY. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... SHORT TERM...APPROACHING TROF OF LOW PRES WILL BRING SN OR RASN MIX CHANGING OVER TO SNWFL FOR ALL TERMINALS BETWEEN 04-08Z. EXPECT IFR CONDITIONS ESPECIALLY CENTERED AROUND 09Z...FOR TERMINALS NEAR THE COAST...KPSM...KPWM...KAUG...AND KRKD. BETWEEN 12-15Z CONDITIONS WILL IMPROVE TO MVFR AND THEN VFR QUICKLY AS HIGH PRES BUILDS IN. SOME GUSTY WNWLY WINDS ARE POSSIBLE FRI AFTERNOON. LONG TERM... SUN...SCT MVFR PSBL IN RAIN OR SNOW SHOWERS. MON PM - TUE AM AREAS OF IFR IN RAIN AND SNOW. && .MARINE... SHORT TERM...BEHIND SFC TROF PASSAGE FRI...WINDS WILL GUST TO NEAR 25 KTS. A SCA MAY BE NEEDED FOR FRI AFTERNOON AND EVENING. LONG TERM... SUN PM - MON AM...SMALL CRAFT WINDS AND SEAS ARE POSSIBLE. TUE PM - WED AM SMALL CRAFT WINDS AND SEAS ARE POSSIBLE. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...WINTER WEATHER ADVISORY UNTIL 8 AM EST FRIDAY FOR MEZ018>028. NH...WINTER WEATHER ADVISORY UNTIL 8 AM EST FRIDAY FOR NHZ010-013. MARINE...NONE. && $$
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1205 AM CST FRI NOV 14 2014 .UPDATE... ISSUED AT 1205 AM CST FRI NOV 14 2014 LATEST SURFACE ANALYSIS SHOWS A 1033MB HIGH PRESSURE STRETCHING FROM EASTERN MONTANA INTO SOUTH CENTRAL NORTH DAKOTA. LIGHT WINDS AND A MOSTLY CLEAR SKY CONTINUES FOR MOST OF WESTERN AND CENTRAL NORTH DAKOTA. THE EXCEPTION IS LOCALIZED PATCHY FOG AND LOW CLOUDS AT HETTINGER...AND A LARGER AREA OF STRATUS ALONG LAKE SAKAKAWEA. GIVEN THE LIGHT WINDS...TEMPERATURE/DEWPOINT SPREADS AND LOCATION OF SURFACE HIGH OVERNIGHT...AND CURRENT FOG/STRATUS LOOP...HAVE MENTIONED PATCHY FOG MAINLY NORTHWEST THROUGH SOUTH CENTRAL AND INTO PORTIONS OF THE SOUTHWEST. LATEST HRRR CIG/VSBY FORECAST DOES ADVERTISE INCREASING LOW CLOUDS INTO ADAMS/HETTINGER/GRANT/SIOUX COUNTIES OVERNIGHT INTO MID MORNING FRIDAY. POTENTIAL IS THERE AS A SOUTHEAST WIND DEVELOPS OVERNIGHT IN RESPONSE TO THE AFOREMENTIONED HIGH PRESSURE OVER SOUTH CENTRAL NORTH DAKOTA SHIFTING INTO EASTERN SOUTH DAKOTA. WILL MONITOR THIS AND THE WIND CHILL ADVISORY FOR THE SOUTHWEST...WHICH STILL REMAINS ON TRACK. UPDATE ISSUED AT 947 PM CST THU NOV 13 2014 TEMPERATURES CONTINUE TO DROP QUICKLY THIS EVENING UNDER A COLD SURFACE RIDGE FROM EASTERN SOUTH DAKOTA NORTH NORTHWEST INTO WESTERN NORTH DAKOTA. ALREADY AT 9 PM THE TEMPERATURE WAS DOWN TO -15 AT HETTINGER AND -13 IN GLEN ULLIN. NEEDLESS TO SAY...WE HAVE LOWERED TEMPERATURES ACROSS MOST OF WESTERN AND CENTRAL NORTH DAKOTA. EVEN IN EASTERN PORTIONS OF CENTRAL NORTH DAKOTA WITH LITTLE SNOW...ROLLA WAS DOWN TO 1 ABOVE. REGARDING THE WIND CHILL ADVISORY...WIND CHILLS WERE CURRENTLY IN THE 10 TO 20 BELOW RANGE OVER THE ADVISORY AREA...WITH THE EXCEPTION OF DICKINSON WHICH WAS -24. THINK THE COLDEST WIND CHILLS WILL COME LATER TONIGHT AS THE SURFACE HIGH SHIFTS EAST AND A SOUTH TO SOUTHEAST FLOW INCREASES SLIGHTLY OVER THE SOUTHWEST. WILL NEED TO KEEP AN EYE ON THE FAR SOUTH CENTRAL WHERE LOWERING TEMPERATURES HAS RESULTED IN WIND CHILLS CLOSE TO ADVISORY CRITERIA. WILL LET IT RIDE FOR NOW AS THE LOWEST WIND CHILLS WOULD LIKELY OCCUR AROUND 12 UTC. THIS WOULD GIVE THE OVERNIGHT CREW TIME TO ISSUE SOMETHING FOR THE EARLY MORNING IF TEMPERATURES DROP MORE THAN FORECAST. OTHERWISE...NO ISSUES WITH CLEAR SKIES EXCEPT FOR SOME STRATUS COMING OFF THE LAKES. UPDATE ISSUED AT 556 PM CST THU NOV 13 2014 HIGH PRESSURE CENTERED OVER THE NORTHERN AND CENTRAL PLAINS WILL DRIFT SOUTHEAST TONIGHT. MOSTLY CLEAR SKIES ACROSS WESTERN AND CENTRAL NORTH DAKOTA. A FEW SCATTERED CLOUDS FROM SOUTHEAST SASKATCHEWAN INTO NORTH CENTRAL NORTH DAKOTA...WITH SOME LOWER STRATUS COMING OFF LAKE SAKAKAWEA. ONLY ADJUSTMENTS WERE TO LOWER SKY COVER MOST AREAS AND POPULATE THE LATEST SENSIBLE WEATHER ELEMENTS. EXPECT TEMPERATURES TO DROP QUICKLY THIS EVENING...WHICH IS HANDLED WELL IN THE CURRENT FORECAST. NO CHANGES TO CURRENT WIND CHILL ADVISORY. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 350 PM CST THU NOV 13 2014 CURRENT SURFACE ANALYSIS PLACES BROAD FRIGID HIGH OVER THE NORTHERN INTO THE CENTRAL PLAINS. UPPER LEVEL ANALYSIS PLACES LOW HEADING OVER EASTERN CANADA WITH WEAK CYCLONIC FLOW REMAINING OVER OUR AREA AS BLOCKING RIDGE REMAINS OFF THE WEST COAST. FOR TONIGHT...BROAD SURFACE HIGH WILL BRING THE COLDEST NIGHT OF THE SEASON TO THE AREA...WITH THE COLDEST LOCATIONS OVER SOUTHWESTERN NORTH DAKOTA OVER THE RECENT SNOW PACK. THIS COLD WILL COMBINE WITH LIGHT WINDS TO BRING FRIGID WINDCHILL VALUES...THUS A WIND CHILL ADVISORY HAS BEEN ISSUED FOR THIS AREA. OTHERWISE...SKIES WILL SLOWLY CLEAR OUT AS UPPER LOW CONTINUES ITS EASTWARD PROGRESSION. ON FRIDAY...QUIET AND COLD WEATHER IS EXPECTED AS BLOCKING PATTERN REMAINS. HIGH TEMPERATURES WILL REMAIN IN THE TEENS THROUGHOUT THE AREA. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 350 PM CST THU NOV 13 2014 CONTINUED COLD THROUGH THE PERIOD AND BLOWING SNOW POTENTIAL SUNDAY HIGHLIGHT THE EXTENDED FORECAST. TODAYS 12Z MODELS CONTINUE TO DEPICT A BLOCKING HIGH AMPLITUDE UPPER LEVEL RIDGE ACROSS THE EASTERN PACIFIC...WITH A DEEP LONGWAVE UPPER LEVEL TROUGH ACROSS NORTH AMERICA. THE MODELS HINT THAT THIS PATTERN MAY BEGIN TO BREAK DOWN TOWARDS THE MIDDLE/END OF NEXT WEEK. FRIDAY NIGHT AND SATURDAY NORTH DAKOTA SHOULD BE UNDER THE INFLUENCE OF COLD HIGH PRESSURE CENTERED ALONG THE FRONT RANGE...AS A LOW PRESSURE SYSTEM SOUTH OF THE STATE PROGRESSES EAST ACROSS THE CENTRAL AND SOUTHERN PLAINS. LOWS FRIDAY NIGHT FROM 5 ABOVE TO 10 BELOW ZERO...HIGHS SATURDAY FROM 5 TO 15 ABOVE ZERO. SATURDAY NIGHT A STRONG UPPER LEVEL SHORTWAVE...PART OF THE WESTERN LOBE OF THE COLD HUDSON BAY LOW...IS FORECAST TO MOVE SOUTH ACROSS CENTRAL CANADA AND APPROACH THE NORTH DAKOTA BORDER. THIS WILL KEEP WESTERLY WINDS OF 15 TO 20 MPH SATURDAY NIGHT - AND LOWS SATURDAY NIGHT SHOULD NOT BE AS COLD AS FRIDAY NIGHT: FROM JUST BELOW ZERO TO NEAR 10 ABOVE ZERO. ON SUNDAY THE UPPER LEVEL SHORTWAVE MOVES SOUTH ACROSS NORTH DAKOTA...BRINGING A STRONG COLD FRONT ACROSS THE STATE. LOOKING AT NORTHWEST WINDS OF 25 TO 35 MPH - WITH GUSTS TO 40 MPH POSSIBLE. AT THIS TIME IT APPEARS THE SOUTHWEST PART OF THE STATE WOULD SEE THE STRONGEST WINDS - AND A WIND ADVISORY POSSIBLE DAYTIME SUNDAY. THE GOOD NEWS IS THAT HIGHS SUNDAY SHOULD BE IN THE 15 TO 25 ABOVE RANGE. COLD AIR BEHIND THE SUNDAY COLD FRONT WILL KEEP TEMPERATURES WELL BELOW AVERAGE...WITH LOWS SUNDAY NIGHT ZERO TO 5 ABOVE...HIGHS MONDAY 10 TO 15 ABOVE...AND LOWS MONDAY NIGHT 5 BELOW TO 5 ABOVE. A BIT WARMER TUESDAY THROUGH THURSDAY AS IT APPEARS THE EASTERN PACIFIC RIDGE BREAKS DOWN...WITH HIGHS IN THE 20S AND LOWS 5 TO 15 ABOVE ZERO. THERE IS A HINT OF A CHANCE OF SNOW TOWARDS THE END OF NEXT WEEK AS A MORE PROGRESSIVE PATTERN WITH A SERIES OF LOW PRESSURE SYSTEMS MOVING EAST ACROSS NORTH AMERICA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1205 AM CST FRI NOV 14 2014 COLD SURFACE RIDGE EXTENDING FROM EASTERN SOUTH DAKOTA INTO NORTHWEST NORTH DAKOTA. GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH THE 06Z TAF PERIOD. HOWEVER...LIGHT SOUTHERLY FLOW IS EXPECTED TO TRANSPORT LOW LEVEL MOISTURE NORTH INTO WESTERN NORTH DAKOTA LATE TONIGHT INTO FRIDAY MORNING. THIS COULD BRING LOW LEVEL STRATUS INTO SOUTHWEST NORTH DAKOTA AROUND 12 UTC AND COULD APPROACH KDIK AND KBIS AROUND 15-18 UTC. NOT SURE ABOUT THE EXTENT OF MOISTURE TRANSPORT SO HAVE STARTED WITH A SCATTERED LOWER STRATUS LAYER AT THESE SITES THURSDAY MORNING. OVERNIGHT SHIFT CAN MONITOR THE PROGRESSION AND UPDATE AS NEEDED. ELSEWHERE...ADDED A TEMPO FOR PATCHY FOG AT KISN FROM 10-13 UTC DUE TO THE PROXIMITY OF THE LAKE AND A LIGHT SURFACE FLOW. && .BIS WATCHES/WARNINGS/ADVISORIES... WIND CHILL ADVISORY UNTIL 8 AM MST FRIDAY FOR NDZ031>033-040-041- 043-044. && $$ UPDATE...KS SHORT TERM...JJS LONG TERM...JMV AVIATION...TWH
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
200 AM EST FRI NOV 14 2014 .SYNOPSIS... PROGRESSIVELY COLDER AIR WILL CONTINUE TO PUSH INTO THE REGION...AND WILL LAST INTO NEXT WEEK. THIS PROLONGED SPELL OF WELL BELOW NORMAL TEMPERATURES WILL BE ACCOMPANIED BY THE FIRST SIGNIFICANT LAKE EFFECT SNOW OF THE SEASON ACROSS THE NORTHWEST SNOWBELT. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... FRONTOGENETICALLY FORCED LGT SNOW THAT BROUGHT THE FIRST DUSTING OF THE SEASON TO PARTS OF THE LOWER SUSQ VALLEY IS SHOWING THE DWINDLING TREND THAT WAS ADVERTISED BY THE HRRR AS THE PARENT UPPER JET STREAK LIFTS AWAY FROM THE REGION. LITTLE MORE THAN FLURRIES LEFT AT 06Z AND RADAR TRENDS SUGGEST THOSE SHOULD END BY 08Z. MAIN FOCUS FOR THE REST OF THE NIGHT WILL BE LAKE EFFECT SNOW SHOWERS ACROSS THE NW MTNS. DIRECTIONAL SHEAR IN THE 0-3KM LAYER...COMBINED WITH ARRIVAL OF DRY AIR AS DEPICTED BY SATL- DERIVED PWATS...IS LEADING TO GENERALLY LIGHT AND DISORGANIZED LE SNOW BANDS OVR NW PA. BLEND OF LATEST RAP/NAM QPF SUPPORTS ONLY UP TO AN ADDITIONAL INCH BTWN 06Z-12Z ACROSS WARREN CO. MAY NEED TO CANCEL CURRENT LAKE WARNING/ADVISORY OVR THE NW MTNS...AS ADDITIONAL ACCUMS LATER TODAY ALSO APPEAR LIGHT. EXPECT CLEARING SKIES EARLY THIS MORNING ACROSS THE SUSQ VALLEY...AS WAVE OF LOW PRES OFF THE E COAST PUSHES AWAY. HOWEVER...LAKE EFFECT STRATOCU WILL KEEP SKIES MCLDY ACROSS THE W MTNS. TEMPS ON TRACK TO BOTTOM OUT FROM ARND 20F OVR THE HIGH TERRAIN OF THE ALLEGHENIES...TO THE M/U20S OVR THE SUSQ VALLEY. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/... FAVORABLE LES SNOW PATTERN CONTINUES FOR THE NW MTNS...WITH FREQUENT SNOW SHOWERS AND LIGHTER ACCUMS FOR THE NORTH-CENTRAL MTNS AND LAURELS AS A BROAD AREA OF STEEP LOW TO MID LEVEL LAPSE RATES AND POCKET OF -15 TO -20C AIR AT 700 MB TRAVERSES THE AREA. VARIABLE CLOUDINESS WILL BE FOUND ACROSS THE CENTRAL MTNS WITH FLURRIES AND ISOLATED TO SCTD SNOW SHOWERS THAT COULD BRIEFLY WHITEN THE GROUND. TEMPS WILL BE 12-15F BELOW NORMAL WITH MAXES RANGING FROM AROUND 30F ACROSS THE NRN AND WRN MTNS...TO THE L40S IN THE SE. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... COLD PATTERN WILL CONTINUE WITH WELL-BELOW AVERAGE TEMPERATURES THROUGH MUCH OF NEXT WEEK... ANOMALOUS UPPER LEVEL RIDGING CENTERED OVER THE YUKON/ALASKA WILL SUSTAIN AND MAINTAIN A DEEP TROUGH AND UNSEASONABLY COLD AIRMASS OVER THE AREA THROUGH THE END OF THE PERIOD. FORECAST CONFIDENCE REMAINS VERY HIGH IN A PROLONGED STRETCH OF COLDER THAN NORMAL TEMPERATURES. THE SIGNIFICANT...LONG DURATION LAKE EFFECT SNOW EVENT OVER THE NW SNOWBELT WILL WIND DOWN BY SATURDAY NIGHT...AS THE LOW LEVEL FLOW BACKS TO THE WSW AND INVERSION HEIGHTS COLLAPSE UNDER INCREASING SUBSIDENCE ASSOCIATED WITH SHORTWAVE RIDGE AND SFC HIGH PRESSURE MIGRATING EWD FROM THE CENTRAL APPALACHIANS OFF THE MID ATLANTIC COAST. IN MOST LOCATIONS...SATURDAY WILL BE COLD AND DRY WITH DAYTIME TEMPERATURE DEPARTURES BETWEEN 10 AND 15 DEGREES BELOW MID NOVEMBER CLIMATOLOGY. MODELS SHOW A LEAD SHORTWAVE CROSSING THE ERN GREAT LAKES ON EARLY SUNDAY WHICH COULD SPREAD SOME LIGHT RAIN/SNOW INTO THE AREA. RELOADING CENTRAL US TROUGH BECOMES WELL ESTABLISHED BY 12Z MONDAY WITH CORE OF NEGATIVE HEIGHT ANOMALIES APPROACHING -3 STD OVER THE UPPER MIDWEST. THERE IS A BROAD CONSENSUS IN A BROAD AREA OF PCPN BLOSSOMING OVER THE AREA ON MONDAY AS MOISTURE AND LIFT BECOME ENHANCED EAST OF THE DEEP TROUGH ALONG SHARPENING FRONTAL AXIS. PTYPES WILL REMAIN CHALLENGING BUT IT LOOKS LIKE ANOTHER POSSIBLE MIX OR CHANGEOVER EVENT FOR AREAS EAST OF THE ALLEGHENY FRONT. THAT SAID...THERE IS ENOUGH SUPPORT TO RAISE POPS INTO THE LKLY RANGE FOR DAY 4.5/5. AN EVEN COLDER SURGE OF MODIFIED ARCTIC AIR SEEMS POISED TO BLAST INTO THE REGION BEHIND THIS SYSTEM ON TUESDAY AND PERSIST THRU THE MIDDLE OF NEXT WEEK. THE OVERALL BROAD CYCLONIC FLOW PATTERN WILL FAVOR LAKE EFFECT AND TERRAIN ENHANCED SNOW SHOWERS OVER THE NW MTNS WITH COLD AND DRY CONDITIONS FROM THE CENTRAL RIDGES INTO THE LWR SUSQ VLY. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... SNOW BANDS CONTINUE TO WEAKEN AS THE TROUGH SWINGS INTO THE NORTHEAST OVERNIGHT. CIGS HAVE LIFTED AT BFD...THOUGH LAKE EFFECT BANDS ARE FORMING AND MOVING ONSHORE. EXPECT CIGS AND VSBYS TO BE REDUCED ONCE AGAIN. BFD SHOULD SEE PERIODS OF IFR THROUGH THE EVENING AND INTO TOMORROW MORNING AS THE LAKE EFFECT FLOW SHOULD REMAIN PERSISTENT THROUGH THIS TIMEFRAME. KJST IS CURRENTLY IFR AND THE MOISTURE FROM THE UPSLOPE FLOW IN THE ALEGHENNIES SHOULD KEEP IFR VSBYS AND CIGS THROUGH MOST OF THE OVERNIGHT HOURS. SOME MOISTURE COULD GET CUT OFF BETWEEN 06Z TO 09Z BUT STRONGER MOISTURE MOVING ONSHORE SHOULD ONCE AGAIN ALLOW FOR A DROP IN CIGS AND VSBYS BY 11Z. EXPECT CIGS AND VSBYS TO LIFT TO MVFR BY MID MORNING...AND VFR BY MIDDAY. IN BTWN...KUNV AND KAOO WILL EXPERIENCE OCNL MVFR CIGS TONIGHT. ARRIVAL OF DRIER AIR MASS BEHIND THE FRONT LATE TONIGHT WILL BRING RISING CIGS OVR MOST OF THE REGION ALONG AND SE OF A LINE FROM KAOO TO KELM. OUTLOOK... FRI...PM SNOW SHOWERS/REDUCED VSBYS POSS AT KBFD AND JST. SAT...AM SNOW SHOWERS/REDUCED VSBYS POSS AT KBFD AND JST. SUN...SNOW SHOWERS/REDUCED VSBYS POSS AT KBFD. MON...LGT SNOW/LOW CIGS POSS NW HALF OF PA. RAIN/LOW CIGS POSS SE. && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ005. LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR PAZ004. && $$ SYNOPSIS...LA CORTE NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD/LAMBERT LONG TERM...STEINBUGL AVIATION...LAMBERT/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1208 AM EST FRI NOV 14 2014 .SYNOPSIS... PROGRESSIVELY COLDER AIR WILL CONTINUE TO PUSH INTO THE REGION...AND WILL LAST INTO NEXT WEEK. THIS PROLONGED SPELL OF WELL BELOW NORMAL TEMPERATURES WILL BE ACCOMPANIED BY THE FIRST SIGNIFICANT LAKE EFFECT SNOW OF THE SEASON ACROSS THE NORTHWEST SNOWBELT. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... FRONTOGENETICALLY FORCED SNOW/RAIN THAT BROUGHT A COATING OF SNOW TO SOME GRASSY SURFACES OVER THE LOWER SUSQ VALLEY IS SHOWING THE DWINDLING TREND THAT WAS ADVERTISED BY THE HRRR AS THE PARENT UPPER JET STREAK LIFTS AWAY FROM THE REGION. LITTLE MORE THAN A FEW LINGERING LIGHT SNOW/RAIN SHOWERS AND SOME FLURRIES ARE LEFT BEHIND OVER CENTRAL AND EASTERN AREAS. FURTHER TO OUR NW...BANDED LAKE EFFECT IS STARTING TO ORGANIZE BUT IT HAS BEEN SLOW. THIS WILL BECOME THE MAIN MODE OF PRECIP THAT WE WILL BE DEALING WITH FOR THE NEXT 24-36 HOURS AS THE WINDS BECOME BETTER ALIGNED OVERNIGHT INTO FRIDAY. WE ARE CONTINUING THE LAKE EFFECT SNOW WARNING THROUGH 00Z SAT FOR WARREN COUNTY...AND THE LAKE EFFECT SNOW ADVISORY ACROSS MCKEAN COUNTY THROUGH THE SAME PERIOD. FROM EARLIER... PERSISTENT LIGHT TO MDT...NWRLY BOUNDARY LAYER FLOW /COUPLED WITH DEEP COLD AIR AND NEARLY A 20C LAKE-850 MB T DIFF...ALONG WITH THE LONG DURATION OF THIS LES EVENT/ LOOKS VERY FAVORABLE FOR HEAVY SNOW AMOUNTS ACROSS THE PERENNIAL SNOWBELT OF NW WARREN COUNTY WHERE OVER 1 FOOT LOOKS POSSIBLE BY FRIDAY NIGHT...WITH SOME ADDITIONAL ACCUMS LIKELY HEADING INTO SATURDAY. THE MEAN WIND IN THE LAYER STEERING THE LAKE EFFECT BANDS WILL VARY BY ABOUT 30 DEG FROM 285-315 DEG TONIGHT INTO FRIDAY...WITH EVEN SOME PULSES OF DRIER AIR CREATING A FEW LULLS IN THE ACTION. STILL...IT`S BEST AT THIS POINT TO PLACE THIS EVENT INTO ONE LONG PACKAGE AND PROVIDE PLENTY OF LEAD TIME FOR THIS FIRST SIGNIFICANT LES EVENT. THE REST OF THE NW MTNS OUTSIDE OF THE LES ADVISORY DOWN THRU THE LAURELS WILL SEE ACCUMULATING SNOW ON THE ORDER OF A FEW TO SVRL INCHES BY THE TIME ITS ALL OVER SATURDAY. HOWEVER...AMOUNTS IN ANY ONE GIVEN 12-24 HOUR PERIOD WON`T REALLY ADD UP TO ADVISORY AMOUNTS. THE EXCEPTION MAY BE ON THE WEST FACING SLOPES OF THE LAURELS SKI COUNTRY WHERE 6 TO 8 INCHES IS POSSIBLE BY 12Z SATURDAY. AFTER THE PASSAGE OF THE COASTAL LOW LOW LATER TONIGHT...CLOUD BASES WITH LIFT ACROSS THE CENTRAL MTNS AND SUSQ VALLEY WITH FLURRIES AND ISOLATED SNOW SHOWERS. LOWS TONIGHT WILL VARY FROM THE L20S ACROSS THE NRN AND WRN MTNS...TO THE MID AND UPPER 20S IN THE SE. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... FAVORABLE LES SNOW PATTERN CONTINUES FOR THE NW MTNS...WITH FREQUENT SNOW SHOWERS AND LIGHTER ACCUMS FOR THE NORTH-CENTRAL MTNS AND LAURELS AS A BROAD AREA OF STEEP LOW TO MID LEVEL LAPSE RATES AND POCKET OF -15 TO -20C AIR AT 700 MB TRAVERSES THE AREA. VARIABLE CLOUDINESS WILL BE FOUND ACROSS THE CENTRAL MTNS WITH FLURRIES AND ISOLATED TO SCTD SNOW SHOWERS THAT COULD BRIEFLY WHITEN THE GROUND. TEMPS WILL BE 12-15F BELOW NORMAL WITH MAXES RANGING FROM AROUND 30F ACROSS THE NRN AND WRN MTNS...TO THE L40S IN THE SE. && .LONG TERM /SATURDAY THROUGH THURSDAY/... COLD PATTERN WILL CONTINUE WITH WELL-BELOW AVERAGE TEMPERATURES THROUGH MUCH OF NEXT WEEK... ANOMALOUS UPPER LEVEL RIDGING CENTERED OVER THE YUKON/ALASKA WILL SUSTAIN AND MAINTAIN A DEEP TROUGH AND UNSEASONABLY COLD AIRMASS OVER THE AREA THROUGH THE END OF THE PERIOD. FORECAST CONFIDENCE REMAINS VERY HIGH IN A PROLONGED STRETCH OF COLDER THAN NORMAL TEMPERATURES. THE SIGNIFICANT...LONG DURATION LAKE EFFECT SNOW EVENT OVER THE NW SNOWBELT WILL WIND DOWN BY SATURDAY NIGHT...AS THE LOW LEVEL FLOW BACKS TO THE WSW AND INVERSION HEIGHTS COLLAPSE UNDER INCREASING SUBSIDENCE ASSOCIATED WITH SHORTWAVE RIDGE AND SFC HIGH PRESSURE MIGRATING EWD FROM THE CENTRAL APPALACHIANS OFF THE MID ATLANTIC COAST. IN MOST LOCATIONS...SATURDAY WILL BE COLD AND DRY WITH DAYTIME TEMPERATURE DEPARTURES BETWEEN 10 AND 15 DEGREES BELOW MID NOVEMBER CLIMATOLOGY. MODELS SHOW A LEAD SHORTWAVE CROSSING THE ERN GREAT LAKES ON EARLY SUNDAY WHICH COULD SPREAD SOME LIGHT RAIN/SNOW INTO THE AREA. RELOADING CENTRAL US TROUGH BECOMES WELL ESTABLISHED BY 12Z MONDAY WITH CORE OF NEGATIVE HEIGHT ANOMALIES APPROACHING -3 STD OVER THE UPPER MIDWEST. THERE IS A BROAD CONSENSUS IN A BROAD AREA OF PCPN BLOSSOMING OVER THE AREA ON MONDAY AS MOISTURE AND LIFT BECOME ENHANCED EAST OF THE DEEP TROUGH ALONG SHARPENING FRONTAL AXIS. PTYPES WILL REMAIN CHALLENGING BUT IT LOOKS LIKE ANOTHER POSSIBLE MIX OR CHANGEOVER EVENT FOR AREAS EAST OF THE ALLEGHENY FRONT. THAT SAID...THERE IS ENOUGH SUPPORT TO RAISE POPS INTO THE LKLY RANGE FOR DAY 4.5/5. AN EVEN COLDER SURGE OF MODIFIED ARCTIC AIR SEEMS POISED TO BLAST INTO THE REGION BEHIND THIS SYSTEM ON TUESDAY AND PERSIST THRU THE MIDDLE OF NEXT WEEK. THE OVERALL BROAD CYCLONIC FLOW PATTERN WILL FAVOR LAKE EFFECT AND TERRAIN ENHANCED SNOW SHOWERS OVER THE NW MTNS WITH COLD AND DRY CONDITIONS FROM THE CENTRAL RIDGES INTO THE LWR SUSQ VLY. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... SNOW BANDS CONTINUE TO WEAKEN AS THE TROUGH SWINGS INTO THE NORTHEAST OVERNIGHT. CIGS HAVE LIFTED AT BFD...THOUGH LAKE EFFECT BANDS ARE FORMING AND MOVING ONSHORE. EXPECT CIGS AND VSBYS TO BE REDUCED ONCE AGAIN. BFD SHOULD SEE PERIODS OF IFR THROUGH THE EVENING AND INTO TOMORROW MORNING AS THE LAKE EFFECT FLOW SHOULD REMAIN PERSISTENT THROUGH THIS TIMEFRAME. KJST IS CURRENTLY IFR AND THE MOISTURE FROM THE UPSLOPE FLOW IN THE ALEGHENNIES SHOULD KEEP IFR VSBYS AND CIGS THROUGH MOST OF THE OVERNIGHT HOURS. SOME MOISTURE COULD GET CUT OFF BETWEEN 06Z TO 09Z BUT STRONGER MOISTURE MOVING ONSHORE SHOULD ONCE AGAIN ALLOW FOR A DROP IN CIGS AND VSBYS BY 11Z. EXPECT CIGS AND VSBYS TO LIFT TO MVFR BY MID MORNING...AND VFR BY MIDDAY. IN BTWN...KUNV AND KAOO WILL EXPERIENCE OCNL MVFR CIGS TONIGHT. ARRIVAL OF DRIER AIR MASS BEHIND THE FRONT LATE TONIGHT WILL BRING RISING CIGS OVR MOST OF THE REGION ALONG AND SE OF A LINE FROM KAOO TO KELM. OUTLOOK... FRI...PM SNOW SHOWERS/REDUCED VSBYS POSS AT KBFD AND JST. SAT...AM SNOW SHOWERS/REDUCED VSBYS POSS AT KBFD AND JST. SUN...SNOW SHOWERS/REDUCED VSBYS POSS AT KBFD. MON...LGT SNOW/LOW CIGS POSS NW HALF OF PA. RAIN/LOW CIGS POSS SE. && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST FRIDAY FOR PAZ005. LAKE EFFECT SNOW WARNING UNTIL 7 PM EST FRIDAY FOR PAZ004. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LAMBERT LONG TERM...STEINBUGL AVIATION...LAMBERT/CERU
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1157 PM EST THU NOV 13 2014 .SYNOPSIS... LOW PRESSURE WAS OFF THE MID ATLANTIC COAST TONIGHT AND WILL DEEPEN OFF THE NEW ENGLAND COAST ON FRIDAY. ARCTIC HIGH PRESSURE WILL BUILD INTO THE REGION INTO SATURDAY. OUR NEXT POTENTIAL WEATHER MAKER MOVES ACROSS THE AREA SUNDAY THROUGH MONDAY WITH GUSTY WINDS AND COLD TEMPERATURES BEHIND IT ON TUESDAY. && .NEAR TERM /THROUGH FRIDAY/... AS OF 1035 PM EST THURSDAY... THE WATER VAPOR LOOP SHOWED A SHORT WAVE CROSSING INTO EASTERN VIRGINIA. THE BETTER AREAL COVERAGE OF RAIN WAS MOVING EAST WITH THIS WAVE. LAST FEW RUNS OF THE HRRR HAD A MAJORITY OF THIS PRECIPITATION EAST OF THE FORECAST AREA BY 08Z/3AM. ANOTHER ELONGATED SHORT WAVE WAS OVER PENNSYLVANIA AND WEST VIRGINIA. SCATTERED SNOW SHOWERS ASSOCIATED WITH THIS FEATURE WERE MOVING ACROSS EASTERN SECTIONS OF WEST VIRGINIA. MSAS ANALYSIS SHOWED PRESSURE FALLS AND A DEEPENING LOW WELL OFF THE DELMARVA PENINSULA. AS THIS LOW CONTINUES TO STRENGTHEN...THE MAGNITUDE OF THE NORTHWEST FLOW COLD AIR ADVECTION INCREASES TONIGHT AND THIS WILL BE THE TIME WHERE OUR REALLY GOOD SURGE OF COLDER AIR COMMENCES ACROSS THE REGION. LOWS TONIGHT WILL RANGE FROM THE UPPER TEENS TO LOWER 20S ACROSS THE MOUNTAINS WITH UPPER 20S TO LOWER 30S ACROSS THE PIEDMONT. ON FRIDAY...NORTHWEST FLOW WILL CONTINUE AND HELP MAINTAIN UPSLOPE CLOUDS ACROSS THE MOUNTAINS THROUGH AT LEAST MIDDAY. IN THE EAST...THE CLOUD COVER WILL CLEAR EARLY GIVEN A DECENT DOWNSLOPE COMPONENT. DRIER AIR WILL EVENTUALLY WIN OUT IN THE MOUNTAINS TOO...WITH MOST REGIONS AT LEAST MOSTLY SUNNY BY THE LATE AFTERNOON. HIGH TEMPERATURES WILL RANGE FROM THE LOW TO MID 30S ACROSS THE MOUNTAINS WITH READINGS AROUND 40 TO THE LOWER 40S ACROSS THE PIEDMONT. SOME OF THE FORECAST HIGHS...ESPECIALLY THOSE IN THE WEST...ARE ONLY EXPECTED TO BE A COUPLE OF DEGREES ABOVE THE RECORD LOW MAXIMUMS FOR THE DAY. SPECIFIC LOW MAXIMUM RECORDS FOR FRIDAY AND SATURDAY ARE IN THE CLIMATE SECTION OF THIS DISCUSSION. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/... AS OF 205 PM EST THURSDAY... COLD HIGH PRESSURE WILL SLIDE EAST ACROSS THE AREA FRIDAY NIGHT AND BE ABOUT OVERHEAD BY SATURDAY MORNING. THIS WILL BRING CLEAR SKIES UNDER STRONG SUBSIDENCE ALONG WITH VERY COLD EARLY MORNING TEMPS SATURDAY AS THE CORE OF THE COLDEST 85H SETTLES OVERHEAD. THIS ALONG WITH GREAT RADIATIONAL COOLING SUPPORTS LOWS IN THE TEENS WEST TO LOW/MID 20S EAST. RIDGING SHIFTS SLOWLY EAST DURING SATURDAY BUT SHOULD HANG ON LONG ENOUGH TO KEEP THINGS MOSTLY SUNNY BUT STILL ON THE COLD SIDE WITH ONLY ABOUT A 3-5+ DEGREE RISE IN 85H TEMPS. HOWEVER EVEN WITH SOME SLIGHT WARMING ALOFT INFLUX OF HIGH LEVEL CLOUDS MAY HOLD TEMPS SLIGHTLY BELOW MOS...MAINLY 38-45. MID LEVEL RIDGING STARTS TO BREAK DOWN SATURDAY NIGHT INTO SUNDAY AS A DEVELOPING 5H TROUGH STARTS TO APPROACH FROM THE WEST. ONSET OF BETTER MID/HIGH LEVEL MOISTURE LIKELY TO BRING INCREASING CLOUDS SATURDAY NIGHT BUT LIKELY THIN ENOUGH EARLY ON TO ALLOW TEMPS TO DIP INTO THE 20S MOST SPOTS BUT STILL DRY. SYSTEM HEADS EAST TOWARD THE REGION BUT QUITE DISORGANIZED INITIALLY WITH NORTHERN STREAM ENERGY PASSING TO THE NW AND THE MAIN SOUTHERN STREAM WAVE STILL HANGING BACK ALONG THE GULF COAST. SOME SOLUTIONS SUCH AS THE GFS REMAIN FAST TO BRING SOME LEAD LIGHT PRECIP NE INTO THE AREA ON SUNDAY WHILE OTHERS PER THE LATEST ECMWF QUITE SLOW WITH LITTLE PRECIP AT ALL DURING THE DAY. GIVEN THE STRONG UPPER JET AND PAST HISTORY OF WEAK LIFT SYSTEMS DEVELOPING PRECIP FASTER...LEFT IN SOME CHANCE POPS SUNDAY AFTERNOON WITH SOME LIGHT SNOW...MAINLY FAR NW WHERE A NAM/GFS MIX WOULD SUPPORT A MORE FROZEN SCENARIO. TEMPS TO WARM A BIT UNDER WARM ADVECTION ALOFT IN ADVANCE OF THE INITIAL FRONT WITH HIGHS MOSTLY 40S EXCEPT LOW 50S SE. DIGGING/AMPLIFYING 5H TROUGH WILL START TO ARRIVE FROM THE NW LATER SUNDAY NIGHT AND HELP ENHANCE MOISTURE COMING NE WITH THE SOUTHERN SHORTWAVE. HOWEVER JUST HOW FAST THIS HAPPENS KEY TO PRECIP COVERAGE SUNDAY NIGHT AS WELL AS THE TEMP PROFILE ALOFT GIVEN DECENT 85H WARM ADVECTION. LATEST GFS FASTER BUT STILL HAS BEST LIFT CLOSER TO THE BAROCLINIC ZONE ALONG THE APPALACHIANS AS WEAK SURFACE WAVES LIFT NE INTO THE CAROLINAS LATE. NEW ECMWF MUCH SLOWER WITH THE SOUTHERN SYSTEM LAGGING FARTHER SOUTH WHICH WOULD RESULT IN ONLY SPOTTY PRECIP. FOR NOW KEPT LIKELY POPS FOR LATER SUNDAY NIGHT BUT WARMER WITH PERHAPS ONLY THE HIGHER ELEVATIONS OVER THE FAR NW STAYING COLD ENOUGH ALOFT FOR SNOW. OTRW LOWS STEADYING OUT IN THE 30S WEST TO AROUND 40 SE. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 PM EST THURSDAY... GENERAL FLAVOR OF MODEL GUIDANCE REMAINS THE SAME FOR THE EXTENDED PERIOD AS A COLD FRONT MOVES THROUGH THE REGION SUNDAY NIGHT WITH A WAVE RIDING UP ALONG THE FRONT FROM THE SOUTHEAST. LOW LEVEL WARM AIR SURGING IN AHEAD OF THIS SYSTEM SHOULD HAVE PTYPE MOSTLY LIQUID UNTIL COLD AIR PUSHES IN FROM THE NORTHWEST LATER ON MONDAY...AND WE TRANSITION OVER TO SNOW AS BULK OF SYNOPTIC PCPN PULLS OUT. UPSLOPE SNOW SHOWERS WILL THEN AFFECT AREAS WEST OF THE BLUE RIDGE MONDAY NIGHT INTO TUESDAY WITH SOME ACCUMULATIONS POSSIBLE FOR THE WESTERN SLOPES. MAY SEE AN UPTICK IN SNOW SHOWERS TOWARD DAYBREAK TUESDAY AS A VIGOROUS SHORT WAVE MOVES SWINGS THROUGH THE BASE OF THE UPPER TROF AND PASSES OVER THE REGION. HIGH PRESSURE WILL THEN PUSH IN FROM THE SOUTHEAST AS MOISTURE RETREATS AND WE ARE QUIET AND COLD FOR LATE TUESDAY INTO WEDNESDAY. HIGH PRESSURE SLIDES OFF TO OUR EAST THURSDAY...ALLOWING SOUTHERLY RETURN FLOW TO MODERATE TEMPERATURES A BIT BEFORE WE SEE AFFECTS OF NEXT SYSTEM APPROACHING FROM THE MISSISSIPPI VALLEY THURSDAY NIGHT. IT LOOKS LIKE MONDAY NIGHT THROUGH TUESDAY NIGHT WILL SEE THE BEST CHANCES FOR WINDY CONDITIONS WITH GOOD DOWNWARD MOMENTUM TRANSFER ABLE TO BRING STRONG LOW LEVEL WINDS TO THE SURFACE. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AS OF 1155 PM EST THURSDAY... SHORT WAVE MOVING INTO EASTERN VIRGINIA...WITH THE ASSOCIATED PRECIPITATION ALSO MOVING EAST..AWAY FROM THE MOUNTAINS AND PIEDMONT. LOW PRESSURE WAS DEEPENING OFF THE MID ATLANTIC COAST WHICH WILL RESULT IN NORTHWEST WINDS AND UPSLOPE CLOUDS AND SNOW SHOWERS IN THE MOUNTAINS. CLOUDS EAST OF THE BLUE RIDGE WILL GRADUALLY CLEAR OVERNIGHT AND SHOULD BE OUT OF KLYH AND KDAN BY 12Z/7AM. WIND GUSTS COULD REACH 20 KNOTS OVERNIGHT. MVFR TO IFR CLOUDS WILL PERSIST ON WESTERN SLOPES THROUGH MUCH OF FRIDAY. MEDIUM CONFIDENCE FOR TIMING OF IMPROVEMENT TO VFR AT KLWB AND KBLF. HIGH PRESSURE BUILDS IN FRIDAY AND FRIDAY NIGHT. WINDS WILL DIMINISH TO LESS THAN 10 KNOTS AFTER SUNSET ON FRIDAY. THE HIGH WILL BRING IN DRIER AND COLDER AIR OF THE END OF THE WEEK. EXTENDED DISCUSSION... AN UPPER LEVEL TROUGH WILL DEVELOP OVER THE EASTERN U.S. AND MAKE ITS WAY NORTHEAST THROUGH SATURDAY. ARCTIC HIGH PRESSURE WILL KEEP MOST AREAS VFR INTO SATURDAY. THE EXCEPTION MAY BE SOME LATE NIGHT RIVER OR VALLEY FOG. SUNDAY INTO MONDAY...A COLD FRONT IS EXPECTED TO MOVE THROUGH THE REGION. THIS WILL BRING SUB-VFR CONDITIONS AND A WINTRY MIX OF PRECIPITATION. MODELS ARE COMING IN WARMER...SO THE TREND IS FOR MORE RAIN AND LESS WINTER PRECIPITATION THREAT. MOST WINTER PRECIPITATION SHOULD BE CONFINED TO THE MOUNTAINS...IMPACTING KLWB/KBLF TO SOME EXTENT...BUT BY NO MEANS A SIGNIFICANT WINTER EVENT. MORE WIDESPREAD -SHSN EXPECTED BEHIND THE FRONT MON NIGHT INTO TUE WITH SOME ACCUMULATIONS POSSIBLE AT THAT TIME...AGAIN MAINLY IMPACTING BLF/LWB. GUSTY NORTHWEST WINDS ARE EXPECTED BEHIND THE SYSTEM ON TUESDAY. && .CLIMATE... RECORD COOLEST HIGHS FRI NOV 14TH BLACKSBURG VA...35 IN 1986 BLUEFIELD WV....29 IN 1975 DANVILLE VA.....39 IN 1997 ROANOKE VA......37 IN 1976 LEWISBURG WV....30 IN 1975 LYNCHBURG VA....37 IN 1996 SAT NOV 15TH BLACKSBURG VA...32 IN 1976 BLUEFIELD WV....23 IN 1969 DANVILLE VA.....41 IN 1986 ROANOKE VA......34 IN 1969 LEWISBURG WV....29 IN 1995 LYNCHBURG VA....36 IN 1969 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS/DS NEAR TERM...AMS/DS SHORT TERM...JH LONG TERM...MBS AVIATION...AMS/DS CLIMATE...DS
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
900 AM MST FRI NOV 14 2014 .SYNOPSIS... A WEAK LOW PRESSURE SYSTEM WILL BRING AN INCREASE IN CLOUDS TO THE REGION TODAY WITH PRECIPITATION MAINLY CONFINED TO NORTHERN ARIZONA. A STRONGER STORM SYSTEM WILL MOVE THROUGH THE REGION SUNDAY...BRINGING AN INCREASE IN WIND ALONG WITH A SLIGHT CHANCE OF SHOWERS EAST OF PHOENIX. COOLER AND DRIER CONDITIONS ARE ANTICIPATED MONDAY BEHIND A COLD FRONT. TEMPERATURES WILL REBOUND TUESDAY TO AROUND NORMAL AND CONTINUE THROUGH NEXT WEEK. && .DISCUSSION... EXTENSIVE THICK MID/HIGH CLOUD COVER CONTINUES TO PROPAGATE INTO THE FORECAST AREA THIS MORNING AHEAD OF A SHEARED WAVE APPROACHING THE SRN CALIFORNIA COASTLINE. 12Z REGIONAL SOUNDING DATA STILL SHOWED A NOTABLE WARM DRY NOSE IN THE H8-H5 LAYER SUCH THAT SOME VIRGA MAY BE SEEN TODAY...BUT ANY PRECIPITATING WILL BE RELEGATED TO NRN ARIZONA HIGHER TERRAIN. THIS CLOUD COVER MAY ACT TO PARTIALLY INHIBIT FULL INSOLATION AND MIXING THIS AFTERNOON...AND THIS SEEMED TO BE ACCOUNTED FOR ALREADY. THUS...ONLY MINOR CHANGES TO CAPTURE SHORT TERM TRENDS WERE NEEDED THIS MORNING. && .PREVIOUS DISCUSSION... /315 AM MST FRI NOV 14 2014/ HIGH CLOUDS CONTINUE TO SPREAD EASTWARD THIS MORNING AHEAD OF AN ADVANCING SHORT-WAVE TROUGH OFF THE CA COAST. MODEL CROSS SECTIONS INDICATE THAT CLOUDS WILL LOWER AND THICKEN THROUGHOUT THE DAY. HOWEVER...GUIDANCE INCLUDING THE HI-RES HRRR IS IN GOOD AGREEMENT THAT PRECIPITATION WILL REMAIN CONFINED TO MAINLY NORTHERN AZ...ASSOCIATED WITH MODEST JET-FORCED ASCENT. MEANWHILE...ABOVE AVERAGE TEMPERATURES WILL PERSIST WITH HIGHS IN THE UPPER 70S IN THE LOWER DESERTS. OTHER THAN A DECREASE IN CLOUDINESS...LITTLE CHANGE IN SENSIBLE WEATHER CONDITIONS IS ANTICIPATED SATURDAY. OVERALL PATTERN ACROSS THE WESTERN CONUS WILL AMPLIFY SUNDAY AS A RIDGE IN THE EASTERN PACIFIC CONSOLIDATES WITH THE ERSTWHILE YUKON BLOCK AND A SHORT-WAVE TROUGH DROPS SOUTHEASTWARD THROUGH THE GREAT BASIN TOWARDS THE FOUR CORNERS. AT THE SURFACE...A COLD FRONT WILL SLIDE SOUTHWARD THROUGH AZ...WITH A NOTICEABLE INCREASE IN WIND SUNDAY AFTERNOON...PARTICULARLY DOWN THE CO RIVER VALLEY WHERE GUSTS MAY APPROACH 35-40 MPH. LATEST DOWNSCALED NAM AND ECMWF ALSO SUGGEST AN INCREASED THREAT OF SHOWERS ACROSS THE HIGHER TERRAIN EAST OF PHOENIX AND POPS WERE NUDGED UPWARDS TO AROUND 20 PERCENT EAST OF GLOBE. A COLDER AIR MASS BEHIND THE FRONT WILL SETTLE ACROSS THE REGION MONDAY...MARKING THE COOLEST AIR OF THE SEASON AND THE FIRST DAY IN ROUGHLY TWO WEEKS OF BELOW NORMAL TEMPERATURES. GFS/ECMWF ALSO INDICATE STRONG SUBSIDENCE IN A NORTHWESTERLY FLOW RESULTING IN SIGNIFICANT DRYING BY MONDAY AFTERNOON WITH SURFACE DEWPOINTS DROPPING INTO THE LOW TEENS OR EVEN SINGLE DIGITS. OPERATIONAL GFS/ECMWF REMAIN IN VERY GOOD AGREEMENT THROUGH NEXT WEEK...DEPICTING THE AFOREMENTIONED RIDGE MIGRATING EAST WHILE WEAKENING ACROSS THE INTERMOUNTAIN WEST. ZONAL FLOW WILL CONSEQUENTLY REDEVELOP ACROSS THE DESERT SOUTHWEST...RESULTING IN OCCASIONAL PERIODS OF HIGH CLOUDS. BIAS-CORRECTED ECMWF ENSEMBLE MOS HAS BEEN A TOP PERFORMER THE PAST TWO WEEKS AND TEMPERATURES WERE WEIGHTED HEAVILY TOWARDS THIS DATASET...YIELDING A SLIGHT DECREASE FROM THE PREVIOUS FORECAST. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... WESTERLY FLOW ALOFT IS EXPECTED TO CONTINUE TO BRING SCT-BKN MID-HIGH CLOUDS LAYERS OVER THE TERMINALS THROUGH THE TAF PERIOD. WEAK SFC PRESSURE GRADIENTS TO KEEP WINDS MAINLY ON THE LIGHT SIDE...AOB 10 KTS...WITH THE USUAL DIURNAL TRENDS IN DIRECTION AND SPEED. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SUNDAY THROUGH THURSDAY... A COLD FRONT MOVING SOUTHWARD INTO THE DESERT SOUTHWEST ON SUNDAY IS EXPECTED TO BRING GUSTY NORTHERLY TO NORTHEASTERLY WINDS TO THE REGION...WITH THE STRONGEST WINDS BLOWING DOWN THE LOWER COLORADO RIVER VALLEY...WHERE NORTHERLY GUSTS TO 40 MPH ARE POSSIBLE AT A FEW SPOTS. THIS FRONT IS EXPECTED TO REMAIN DRY AT MOST LOCATIONS...EXCEPT PERHAPS A FEW SPRINKLES OR LIGHT SHOWERS OCCURRING OVER THE HIGHER TERRAIN EAST OF PHOENIX. MUCH LIGHTER WINDS ARE EXPECTED FROM MONDAY ONWARD INTO THURSDAY. MUCH DRIER AND COOLER AIR BEHIND THE AFOREMENTIONED COLD FRONT WILL ALSO PUSH MINIMUM HUMIDITIES DOWN FROM THE TEENS AND 20S ON SUNDAY INTO THE SINGLE DIGITS-TEENS ON MONDAY AND TUESDAY...WITH A RECOVERY BACK INTO THE TEENS AND 20S EXPECTED ON WEDNESDAY AND THURSDAY. POOR OVERNIGHT HUMIDITY RECOVERIES ON SUNDAY AND MONDAY NIGHT WILL BECOME FAIR TO GOOD BY WEDNESDAY AND THURSDAY NIGHT. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...MO/HIRSCH AVIATION...PERCHA FIRE WEATHER...PERCHA
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
315 AM MST FRI NOV 14 2014 .SYNOPSIS... A WEAK LOW PRESSURE SYSTEM WILL BRING AN INCREASE IN CLOUDS TO THE REGION TODAY WITH PRECIPITATION MAINLY CONFINED TO NORTHERN ARIZONA. A STRONGER STORM SYSTEM WILL MOVE THROUGH THE REGION SUNDAY...BRINGING AN INCREASE IN WIND ALONG WITH A SLIGHT CHANCE OF SHOWERS EAST OF PHOENIX. COOLER AND DRIER CONDITIONS ARE ANTICIPATED MONDAY BEHIND A COLD FRONT. TEMPERATURES WILL REBOUND TUESDAY TO AROUND NORMAL AND CONTINUE THROUGH NEXT WEEK. && .DISCUSSION... HIGH CLOUDS CONTINUE TO SPREAD EASTWARD THIS MORNING AHEAD OF AN ADVANCING SHORT-WAVE TROUGH OFF THE CA COAST. MODEL CROSS SECTIONS INDICATE THAT CLOUDS WILL LOWER AND THICKEN THROUGHOUT THE DAY. HOWEVER...GUIDANCE INCLUDING THE HI-RES HRRR IS IN GOOD AGREEMENT THAT PRECIPITATION WILL REMAIN CONFINED TO MAINLY NORTHERN AZ...ASSOCIATED WITH MODEST JET-FORCED ASCENT. MEANWHILE...ABOVE AVERAGE TEMPERATURES WILL PERSIST WITH HIGHS IN THE UPPER 70S IN THE LOWER DESERTS. OTHER THAN A DECREASE IN CLOUDINESS...LITTLE CHANGE IN SENSIBLE WEATHER CONDITIONS IS ANTICIPATED SATURDAY. OVERALL PATTERN ACROSS THE WESTERN CONUS WILL AMPLIFY SUNDAY AS A RIDGE IN THE EASTERN PACIFIC CONSOLIDATES WITH THE ERSTWHILE YUKON BLOCK AND A SHORT-WAVE TROUGH DROPS SOUTHEASTWARD THROUGH THE GREAT BASIN TOWARDS THE FOUR CORNERS. AT THE SURFACE...A COLD FRONT WILL SLIDE SOUTHWARD THROUGH AZ...WITH A NOTICEABLE INCREASE IN WIND SUNDAY AFTERNOON...PARTICULARLY DOWN THE CO RIVER VALLEY WHERE GUSTS MAY APPROACH 35-40 MPH. LATEST DOWNSCALED NAM AND ECMWF ALSO SUGGEST AN INCREASED THREAT OF SHOWERS ACROSS THE HIGHER TERRAIN EAST OF PHOENIX AND POPS WERE NUDGED UPWARDS TO AROUND 20 PERCENT EAST OF GLOBE. A COLDER AIR MASS BEHIND THE FRONT WILL SETTLE ACROSS THE REGION MONDAY...MARKING THE COOLEST AIR OF THE SEASON AND THE FIRST DAY IN ROUGHLY TWO WEEKS OF BELOW NORMAL TEMPERATURES. GFS/ECMWF ALSO INDICATE STRONG SUBSIDENCE IN A NORTHWESTERLY FLOW RESULTING IN SIGNIFICANT DRYING BY MONDAY AFTERNOON WITH SURFACE DEWPOINTS DROPPING INTO THE LOW TEENS OR EVEN SINGLE DIGITS. OPERATIONAL GFS/ECMWF REMAIN IN VERY GOOD AGREEMENT THROUGH NEXT WEEK...DEPICTING THE AFOREMENTIONED RIDGE MIGRATING EAST WHILE WEAKENING ACROSS THE INTERMOUNTAIN WEST. ZONAL FLOW WILL CONSEQUENTLY REDEVELOP ACROSS THE DESERT SOUTHWEST...RESULTING IN OCCASIONAL PERIODS OF HIGH CLOUDS. BIAS-CORRECTED ECMWF ENSEMBLE MOS HAS BEEN A TOP PERFORMER THE PAST TWO WEEKS AND TEMPERATURES WERE WEIGHTED HEAVILY TOWARDS THIS DATASET...YIELDING A SLIGHT DECREASE FROM THE PREVIOUS FORECAST. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... WESTERLY FLOW ALOFT IS EXPECTED TO CONTINUE TO BRING SCT-BKN MID-HIGH CLOUDS LAYERS OVER THE TERMINALS THROUGH THE TAF PERIOD. WEAK SFC PRESSURE GRADIENTS TO KEEP WINDS MAINLY ON THE LIGHT SIDE...AOB 10 KTS...WITH THE USUAL DIURNAL TRENDS IN DIRECTION AND SPEED. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SUNDAY THROUGH THURSDAY... A COLD FRONT MOVING SOUTHWARD INTO THE DESERT SOUTHWEST ON SUNDAY IS EXPECTED TO BRING GUSTY NORTHERLY TO NORTHEASTERLY WINDS TO THE REGION...WITH THE STRONGEST WINDS BLOWING DOWN THE LOWER COLORADO RIVER VALLEY...WHERE NORTHERLY GUSTS TO 40 MPH ARE POSSIBLE AT A FEW SPOTS. THIS FRONT IS EXPECTED TO REMAIN DRY AT MOST LOCATIONS...EXCEPT PERHAPS A FEW SPRINKLES OR LIGHT SHOWERS OCCURRING OVER THE HIGHER TERRAIN EAST OF PHOENIX. MUCH LIGHTER WINDS ARE EXPECTED FROM MONDAY ONWARD INTO THURSDAY. MUCH DRIER AND COOLER AIR BEHIND THE AFOREMENTIONED COLD FRONT WILL ALSO PUSH MINIMUM HUMIDITIES DOWN FROM THE TEENS AND 20S ON SUNDAY INTO THE SINGLE DIGITS-TEENS ON MONDAY AND TUESDAY...WITH A RECOVERY BACK INTO THE TEENS AND 20S EXPECTED ON WEDNESDAY AND THURSDAY. POOR OVERNIGHT HUMIDITY RECOVERIES ON SUNDAY AND MONDAY NIGHT WILL BECOME FAIR TO GOOD BY WEDNESDAY AND THURSDAY NIGHT. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...HIRSCH AVIATION...PERCHA FIRE WEATHER...PERCHA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
406 AM PST FRI NOV 14 2014 .SYNOPSIS...DENSE FOG THIS MORNING...MAINLY IN THE NORTH BAY OTHERWISE PARTLY CLOUDY AND DRY THROUGH THE WEEKEND WITH SEASONABLE TEMPERATURES. SOME DRIER OFFSHORE WINDS MAY DEVELOP SUNDAY AND MONDAY LEADING TO A WARMING AND DRYING TREND AS HIGH PRESSURE BUILDS. THE NEXT PACIFIC FRONT LOOKS TO ARRIVE LATER TUESDAY INTO WEDNESDAY WITH A CHANCE OF SOME LIGHT RAIN. && .DISCUSSION...AS OF 3:40 AM PST FRIDAY...SHORT TERM FOCUS IS WITH DENSE FOG IN THE NORTH BAY. NAPA...SANTA ROSA AND PETALUMA HAVE BEEN REPORTING 1/4 MILE FOG OR LESS MOST OF THE NIGHT SO A DENSE FOG ADVISORY HAS BEEN ISSUED FOR THE NORTH BAY VALLEYS UNTIL 9 AM TO COVER THE MORNING COMMUTE HOURS. AS A HIGH CLOUD DECK SHIFTS SOUTH TOWARDS SOUTHERN CALIFORNIA THE CLEARING SKIES WILL LIKELY ALLOW SOME MORE AREAS OF DENSE FOG TO DEVELOP THROUGH SUNRISE BUT FOR NOW THE MOST WIDESPREAD FOG IS OVER THE NORTH BAY. SKIES SHOULD TURN PARTLY TO MOSTLY SUNNY THIS AFTERNOON WITH MUCH MORE SUNSHINE COMPARED TO THURSDAY ALLOWING TEMPERATURES TO WARM INTO THE UPPER 60S FOR MOST OF THE DISTRICT. WILL HAVE TO MONITOR FOR SOME MORE DENSE FOG POTENTIAL TONIGHT BUT IN GENERAL THE WEATHER LOOKS DRY AND QUIET THIS WEEKEND. ON SATURDAY AN INSIDE SLIDER TYPE EVENT WILL DEVELOP OVER EASTERN OREGON AND BEGIN TO DROP DOWN THE EAST SIDE OF THE SIERRA OVER NEVADA. THIS WILL KEEP CONDITIONS DRY AND SEASONABLE FOR SATURDAY AFTERNOON. AS THE FRONT DROPS INTO THE GREAT BASIN ON SUNDAY A NORTHERLY/OFFSHORE SURFACE GRADIENT WILL DEVELOP. MODELS ARE NOW SHOWING SOME DRY NORTHEASTERLY 925 MB WINDS BY SUNRISE SUNDAY IN THE 25 KNOT RANGE. FOR THE MOST PART EXPECT THESE WINDS TO STAY ABOVE THE RIDGE-LINES OF THE NORTH AND EAST BAY HILLS WITH ONLY PLACES LIKE MOUNT DIABLO SEEING MUCH WIND OF NOTE. HOWEVER THE GRADIENT WILL INCREASE BY SUNDAY AFTERNOON AND USHER IN A MUCH DRIER AIRMASS WITH HUMIDITY VALUES CRASHING LATER SUNDAY INTO MONDAY. DRY NORTH TO NORTHEAST FLOW CONTINUES ON MONDAY WITH COLD AIR OVER THE GREAT BASIN...ALLOWING A SANTA ANA TO SET UP OVER SOCAL. THE BAY AREA SHOULD SEE SUNNY SKIES WITH HUMIDITY VALUES IN THE TEENS ON MONDAY. EVEN WITH OFFSHORE FLOW THE SOURCE REGION OF THE AIRMASS IS COLD SO ONLY LOOKING FOR HIGHS IN THE 70S AS HIGH PRESSURE PEAKS BY MONDAY EVENING. A PACIFIC FRONT WILL APPROACH ON TUESDAY AS THE FLOW TURNS ONSHORE. RIGHT NOW IT LOOKS LIKE A CHANCE FOR SOME LIGHT RAIN BY TUESDAY EVENING INTO EARLY WEDS BUT CONFIDENCE REMAINS LOW GIVEN THE PATTERN AND POOR MODEL CONSISTENCY. STILL LOOKS LIKE ANY GOOD CHANCE OF BENEFICIAL RAINS REMAINS IN THE EXTENDED FORECAST WITH THE MODELS CONTINUING TO HINT AT STRONGER WESTERLIES BY ABOUT NEXT FRIDAY. && .AVIATION...AS OF 4:00 AM PST FRIDAY...TRICKY FORECAST THIS MORNING WITH SEVERAL FACTORS AT PLAY. SATELLITE IMAGERY SHOWS HIGH CLOUDS HAVE NOW PUSHED SOUTH OF ALL TAF SITES RESULTING IN A RACE AGAINST TIME FOR FOG TO DEVELOP BEFORE SUNRISE. IN THE NORTH BAY VALLEYS...INLCUDING KSTS AND KAPC...CLEARING SKIES AND LIGHT WINDS CREATED A FAVORABLE ENVIRONMENT FOR FOG DEVELOPMENT AND VISBYS ARE 1/4SM OR LESS. AS OF LAST OBSERVATION... KOAK IS REPORTING CLEAR SKIES AFER LOW CLOUDS DISSIPATED ... HOWEVER GOES-W CIG PROBABILITY PRODUCT INDICTATES LOW CLOUDS ARE STILL IN THE VICINITY. KOAK/EAST BAY COULD BE THE NEXT AREA OF FOG DEVELOPMENT IF WINDS REMAIN CALM AND SKIES REMAIN CLEAR IN THE VICINITY. LEAST WORRIED ABOUT FOG AT KSFO...HOWEVER CAN NOT RULE IT OUT WITH HRRR HINTING AT DEVELOPMENT BETWEEN 14-16Z. GRADUAL CLEARING OF LOW CIGS EXPECTED LATE FRIDAY MORNING WITH VFR CONDITIONS IN MOST AREAS BY MIDDAY. PATCHY LOW CLOUDS MAY PERSIST WELL INTO THE AFTERNOON HOURS. OVERALL CONFIDENCE IS LOW AT KSFO/KOAK... AND MEDIUM TO HIGH ELSEWHERE. VICINITY OF KSFO... MVFR WITH LOCAL IFR CIGS AND PATCHY FOG POSSIBLE THROUGH FRIDAY MORNING...MAINLY ON EAST SIDE OF SF BAY BETWEEN 14-17Z FRI. LOW CIGS WILL LIKELY CLEAR BETWEEN 18-20Z FRIDAY MORNING. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...MVFR CIGS WITH BRIEF PATCHY IFR CIGS POSSIBLE THROUGH EARLY MORNING. VFR CONDITIONS FORECAST TO RETURN BY LATE MORNING. LIGHT WINDS. && .MARINE...AS OF 03:43 AM PST FRIDAY...GENERALLY WEAK NORTHWEST FLOW WILL PERSIST ACROSS A MAJORITY OF THE COASTAL WATERS THROUGH THE WEEKEND. THE EXCEPTION WILL BE OFF THE BIG SUR COAST WITH MODERATE NORTHWEST WINDS EXPECTED AT TIMES. A DOMINATE WEST TO NORTHWEST SWELL WILL GRADUALLY DECAY ALONG WITH SHORTENING PERIODS THROUGH EARLY NEXT WEEK. NEXT SIGNIFICANT SHIFT IN SEAS ARRIVES TUESDAY TO WEDNESDAY OF NEXT WEEK. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...DENSE FOG ADVISORY...DENSE FOG ADVISORY TIL 9 AM FOR NORTH BAY VALLEYS. && $$ PUBLIC FORECAST: RWW AVIATION/MARINE: DRP VISIT US AT WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS PUEBLO CO
409 AM MST FRI NOV 14 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 400 AM MST FRI NOV 14 2014 ...MAX TEMPS TODAY ON THE PLAINS WILL SHOW LOTS OF VARIABILITY... ...SAN JUANS TO GET POUNDED THIS EVENING... CURRENTLY... AT 2 AM...TEMPS THIS MORNING SHOWING QUITE A BIT OF VARIABILITY ACROSS THE REGION. THE ARCTIC AIR HAS ALREADY BEGUN TO RETREAT AS ELEVATIONS GENERALLY ABOVE 6500 FEET ARE IN THE (RELATIVELY) WARMER AIR. AS AN EXAMPLE...AREAS OF N EL PASO COUNTY ARE IN THE TEENS AND 20S WHILE KCOS WAS 3F. AREAS JUST WEST OF WALSENBURG AND WEST OF KTAD WERE IN THE 20S AND 30S WHILE COLORADO CITY AND TRINIDAD WERE 2 AND 7F RESPECTIVELY. IN THE MTNS AND VALLEYS IT WAS RELATIVELY WARM WITH 2 AM TEMPS IN THE 20S TO LOWER 30S. SNOW WAS FALLING ACROSS THE CONTDVD AND ACROSS THE SANGRE DE CRISTO MTNS. TODAY... I AM QUITE CONFIDENT WE ARE GOING TO SEE QUITE A BIT OF VARIABILITY IN MAX TEMPS TODAY OVER THE PLAINS...I AM JUST UNCERTAIN ON THE MAGNITUDE OF THE VARIABILITY. HRRR GUIDANCE SHOWS AREAS OF THE LWR ARK RVR VLY FROM KPUB EASTWARD TO KLAA NOT GETTING OUT OF THE TEENS WHILE AREAS N AND S OF THE RIVER WILL GET INTO THE 30S AND 40S. FOR NOW I AM NOT GOING TO GO THAT EXTREME...ALTHOUGH I PLAN TO KEEP AREAS OF THE LOWER ARK RVR VALLEY MUCH COOLER THAN THE SURROUNDING PLAINS. FOR NOW PLAN TO HAVE AREAS SUCH AS KPUB...KLHX AND KLAA IN THE UPPER 20S TO LOWER 30S WHILE KCOS WILL BE IN THE UPPER 30S...AIR FORCE AROUND 40...CANON CITY...COLORADO CITY...WALSENBURG AND TRINIDAD WILL BE IN THE MID 40S. I WOULD NOT BE TOO SURPRISED IF PUEBLO WEST WAS IN THE MID 40S WHILE KPUB WILL BE IN THE LOWER 30S. THE WARMEST AREA ACROSS THE REGION TODAY WILL LIKELY BE THE SAN LUIS VALLEY WHERE KALS WILL LIKELY BE IN THE LOWER 50S. AS FOR THE MTNS...ALTHOUGH A WINTER STORM WARNING IS IN EFFECT ALL DAY FOR THE CONTDVD REGION...I EXPECT SNOW TO DECREASE SIGNIFICANTLY LATER THIS MORNING ACROSS THE DIVIDE (SOME AREAS MAY SEE THE SNOW STOP COMPLETELY). THE SNOW WILL LIKELY NOT START TO RAMP UP AGAIN UNTIL MID TO LATER AFTERNOON ACROSS THE DIVIDE. HOWEVER...ONCE IT RAMPS UP AGAIN...IT WILL REALLY RAMP UP...ESPECIALLY ACROSS THE SAN JUANS (SEE TONIGHT). TONIGHT... THE SAN JUANS ARE LIKELY GOING TO GET POUNDED ESPECIALLY THIS EVENING. SNOWFALL RATES WILL LIKELY EXCEED 2" PER HOUR FOR AT LEAST A FEW HOURS THIS EVENING AS THE BEST FORCING MOVES ACROSS. ALL GUIDANCE INDICATES THIS. A FEW LTG FLASHES ARE LIKELY THIS EVENING AS THIS FORCING MOVES ACROSS (SEE SPC DAY1 GUIDANCE). THE C MTNS WILL ALSO SEE PERIODS OF HEAVY SNOW TONIGHT. IN ADDITION...HAVE ADDED HILITES FOR THE SANGRES AS THEY WILL LIKELY SEE 4-8" TONITE. THE BEST CHANCE FOR THE SAN LUIS VALLEY TO SEE PRECIP WILL BE THIS EVENING. LOCALLY 1-2" ACCUMS WILL BE POSSIBLE...ESPECIALLY AREAS CLOSER TO THE MOUNTAINS. THE PLAINS WILL LIKELY SEE SOME PRECIP TONIGHT. OVERALL...GUIDANCE HAS BACKED OFF SOME AND I HAVE REDUCED POPS OVER THE PLAINS. THE BEST CHANCE OF ANY ACCUM PRECIP STILL APPEARS TO BE OVER THE FAR EASTERN PLAINS...ALTHOUGH IF A SNOW BAND DEVELOPS...(AS SOME GUIDANCE IS HINTING AT)...LOCALLY 1-2" ACCUMS WILL BE POSSIBLE. THE PLAINS WILL HAVE TO BE WATCHED CAREFULLY LATE TODAY TO SEE IF ANY BANDED PRECIP DEVELOPS. /HODANISH .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 400 AM MST FRI NOV 14 2014 ...A COUPLE MORE SYSTEMS TO IMPACT THE AREA THROUGH THE WEEKEND... THE WINTER STORM WARNING WILL REMAIN IN EFFECT FOR THE SAN JUAN AND LA GARITA MOUNTAINS...CONTINENTAL DIVIDE...THROUGH 5 AM SUNDAY. HOWEVER...SOME CONCERN THAT THERE WILL BE A DEFINITE LULL IN THE SNOWFALL SATURDAY AFTERNOON AS THE PACIFIC SHORTWAVE MOVES OUT OF COLORADO. NEXT TROF DROPPING SOUTH OF CANADA WILL IMPACT THE AREA SATURDAY AFTERNOON AND SATURDAY NIGHT. THIS TROF WILL HAVE A WIDER IMPACT ON THE FORECAST AREA AS TEMPERATURES COOL DURING THE DAY SATURDAY WITH FRONT MOVING THROUGH THE PLAINS AND A BAND OF SNOW SETTING UP ALONG THE I-25 CORRIDOR AND THE SOUTHEAST PLAINS SATURDAY NIGHT. GFS HAS MOST OF THE PRECIPITATION/SNOWFALL ALONG THE EAST SLOPES OF THE RAMPARTS AND SANGRES. HUERFANO AND LAS ANIMAS COUNTIES MAY SEE THE BULK OF THE SNOWFALL WITH THIS SYSTEM OVERNIGHT SATURDAY WITH A BAND OF SNOW STRETCHING INTO BACA COUNTY. LATER SHIFTS MAY HAVE TO BALANCE THE WINTER STORM HIGHLIGHTS...MAYBE DOWNGRADING THE WINTER STORM WARNING FOR THE CONTINENTAL DIVIDE AS THE SNOWFALL DIMINISHES...AND AN EYE TOWARD A HIGHLIGHT FOR THE SOUTHERN I-25 CORRIDOR AND SOUTHERN PLAINS. ECMWF AND NAM NOT AS BULLISH ON THE QPF FOR THE SAME AREAS...SO SOME UNCERTAINTY REMAINS. HAVE TRIED TO TIME THE FRONTAL PASSAGE ON THE PLAINS AND FALLING TEMPERATURES DURING THE DAY SATURDAY. TROF CONTINUES TO MOVE SOUTH SUNDAY WITH NORTHWESTERLY FLOW ALOFT EXPECTED TO BRING ANOTHER FRONTAL BOUNDARY THROUGH THE EASTERN PLAINS MONDAY NIGHT...THOUGH TEMPERATURES WILL NOT FALL AS MUCH BEHIND THIS FRONT. SNOW SHOWERS ARE POSSIBLE IN THE CENTRAL MOUNTAINS WITH THIS NORTHWEST FLOW. GENERALLY DRY AND WARMER CONDITIONS ARE EXPECTED TUESDAY THROUGH AT LEAST THURSDAY WITH WESTERLY FLOW ALOFT AND WEAK LEE TROF DEVELOPING AT THE SURFACE. WEATHER PATTERN REMAINS ACTIVE TO OUR NORTH AND WEST AND EXTENDED MODELS DO SHOW ENERGY MOVING INTO THE NORTH CENTRAL MOUNTAINS THURSDAY. STARK && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 400 AM MST FRI NOV 14 2014 KCOS AND KPUB...EXPECT VFR CONDITIONS THROUGH THE NEXT 24 HOURS. WE MAY SEE SOME SNOW SHOWERS DEVELOP THIS EVENING ALTHOUGH THE PRECIP...IF IT DEVELOPS...SHOULD NOT LAST. AT THIS TIME I PLAN TO MENTION ONLY VCSH IN THE TAF PRODUCTS. WINDS WILL BE LIGHT. KALS...PRETTY POTENT DISTURBANCE WILL MOVE ACROSS THE MTNS TONIGHT AND EXPECT THE VALLEY WILL SEE SOME SNOW. THE BEST CHANCE OF IFR CONDITIONS DUE TO CIGS/PRECIP WILL BE BETWEEN 03Z AND 09Z TONIGHT AT KALS. OTHERWISE...VFR AND LIGHT WINDS. SNOW/LIFR CONDITIONS WILL OCCUR ACROSS THE MTNS EARLY THIS MORNING. PRECIP WILL DECREASE LATER THIS MORNING AND EARLY AFTERNOON...BUT WILL RETURN BY LATE AFTERNOON. INTENSE SNOWFALL IS EXPECTED OVER THE CONTDVD AND THE SANGRE DE CRISTO MTNS TONIGHT. && .PUB WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 5 AM MST SUNDAY FOR COZ058-060-066- 068. WINTER WEATHER ADVISORY FROM 11 AM THIS MORNING TO 5 AM MST SATURDAY FOR COZ073-075. WINTER WEATHER ADVISORY UNTIL 5 AM MST EARLY THIS MORNING FOR COZ059-061. && $$ SHORT TERM...HODANISH LONG TERM...STARK AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1038 AM EST FRI NOV 14 2014 .SYNOPSIS... A LARGE AREA OF CANADIAN HIGH PRESSURE WILL BUILD INTO THE REGION THROUGH SUNDAY. THE HIGH WILL WEAKEN AND RETREAT TO THE NORTHEAST SUNDAY NIGHT IN ADVANCE OF A LOW PRESSURE SYSTEM AND STRONG COLD FRONT EXPECTED TO AFFECT THE AREA ON MONDAY. ANOTHER AREA OF COLD CANADIAN HIGH PRESSURE WILL BUILD IN STARTING TUESDAY AND PREVAIL THROUGH LATE NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... THE LEADING EDGE OF THE COLD CANADIAN AIRMASS HAS DROPPED THROUGH MUCH OF THE FORECAST AREA THIS MORNING. HOWEVER...THUS FAR THE COLD LAYER IS ONLY ABOUT 2500 FT DEEP...AND DEEP WESTERLY FLOW ABOVE THAT IS PRODUCING A LARGE AREA OF LOW STRATUS ACROSS SOUTHERN SC AND INLAND GA. A SECONDARY DRY FRONT WILL DROP THROUGH THE AREA DURING THE AFTERNOON WITH MODEL SOUNDINGS SHOWING THE CLOUD- PRODUCING MOISTURE LAYER DISSIPATING BY SUNSET. IN THE MEANTIME THE LOW STRATUS WILL CONTINUE TO MOVE SOUTH AND AFFECT MOST OF OUR AREA BY EARLY AFTERNOON AS THE PRELIMINARY WIND SHIFT OCCURS. NEEDLESS TO SAY THE COMBINATION OF LOW-LEVEL COLD ADVECTION AND SUN-BLOCKING STRATUS WILL KEEP TEMPERATURES FROM RISING MUCH TODAY...EXCEPT ACROSS OUR FAR SOUTHERN ZONES WHERE FULL SUNSHINE AND NW FLOW ALLOWS TEMPS TO RISE INTO THE MID/UPPER 50S. A BRIEF RISE TO LOWER 50S TEMPS IN SOUTHERN SC WILL TRANSITION TO A SLOW COOLING TREND WITH VALUES DROPPING INTO THE UPPER 40S DURING THE AFTERNOON. STRONG COLD AIR ADVECTION CONTINUES INTO TONIGHT WITH 5-10 MPH NORTHERLY FLOW PERSISTING. ALTHOUGH THE MIXED BOUNDARY LAYER WILL REDUCE THE EFFECTS OF RADIATIONAL COOLING...CLEAR SKIES WILL ONLY HELP TEMPS PLUMMET AFTER DARK. WE ARE STILL SHOWING OVERNIGHT LOWS IN THE UPPER 20S FAR INLAND WITH READINGS AT OR SLIGHTLY BELOW FREEZING IN MANY LOCATIONS AWAY FROM THE GA COAST AND SC BEACHES. FREEZE WATCHES IN PLACE FOR ALL BUT THE IMMEDIATE COASTAL ZONES OF SE GEORGIA. LAKE WINDS...WE STILL ARE FORECASTING FREQUENT WIND GUSTS JUST BELOW ADVISORY CRITERIA ON LAKE MOULTRIE BUT WILL MAINTAIN MENTION OF THE POSSIBILITY IN THE HAZARDOUS WEATHER OUTLOOK SINCE OCCASIONAL GUSTS TOPPING 25 KT ARE POSSIBLE. && .SHORT TERM /SATURDAY THROUGH MONDAY/... SATURDAY AND SATURDAY NIGHT...A FAST NEARLY ZONAL FLOW WILL PREVAIL ALOFT AS COLD HIGH PRESSURE AT THE SURFACE BECOMES POSITIONED JUST TO THE NORTH. DEEP DRY AIR WILL PREVAIL THROUGH THE DAY AND A DRY FORECAST IS IN PLACE. THE MAIN STORY FOR THE DAY WILL BE THE VERY COLD AIR WITH HIGHS STRUGGLING TO REACH THE LOW 50S TO THE NORTH AND MID 50S TO THE SOUTH. SUCH VALUES WOULD BE NEARLY 20 DEGREES BELOW NORMAL FOR MID NOVEMBER. THEN LATE IN THE DAY SATURDAY AND THROUGH THE OVERNIGHT...THE SURFACE PATTERN WILL BEGIN TO TAKE ON A MORE WEDGE LIKE PATTERN. IN FACT...A INCREASINGLY DISCERNIBLE COASTAL TROUGH LOOKS AS THOUGH IT WILL TAKE SHAPE WITH INCREASING LOW LEVEL MOISTURE NOTED IN MODEL SOUNDINGS AND TIME HEIGHTS. LAND AREAS WILL MAINLY BE DRY...BUT THE ADJACENT COASTAL WATERS WILL BEGIN TO SEE AN INCREASE IN SHOWER ACTIVITY WITHIN THE LOW LEVEL CONVERGENCE IN THE DEVELOPING TROUGH. LOWS WILL FALL INTO THE UPPER 30S INLAND...RANGING TO THE LOW TO MID 40S AT THE COAST. SUNDAY AND MONDAY...THE OVERALL PATTERN BECOMES A BIT MORE COMPLEX. SUNDAY INCREASINGLY LOOKS LIKE A WEDGE DAY AS THE MAIN PARENT HIGH SLIPS OFF THE BUT CONTINUES TO RIDGE INTO THE CAROLINAS AND GEORGIA. THE INLAND WEDGE WILL BE REINFORCED BY THE COASTAL TROUGH AS WELL AS THROUGH DIABATIC PROCESSES ASSOCIATED WITH LIGHT PRECIPITATION SPREADING INTO LAND AREAS BEGINNING SUNDAY MORNING. THIS COLD AIR DAMMING REGIME WILL NECESSITATE LOWERING SUNDAY HIGH TEMPS RATHER SIGNIFICANTLY. HIGHS HAVE BEEN LOWERED INTO THE UPPER 50S INLAND TO AROUND 60 AT THE COAST WITH THIS FORECAST PACKAGE...AND THIS MAY BE A BIT OPTIMISTIC. FURTHER DOWNWARD ADJUSTMENTS MAY BE NEEDED WITH SUBSEQUENT UPDATES. AT SOME POINT SUNDAY NIGHT INTO MONDAY...THE WEDGE WILL ERODE AS THE HIGH WEAKENS AND THE DEVELOPING AREA OF LOW PRESSURE ACROSS THE LOWER MISSISSIPPI VALLEY LIFTS A WARM FRONT THROUGH THE AREA. THE MOST ACTIVE WEATHER DAY WILL THEN BE MONDAY AS SHORTWAVE ENERGY TRANSLATES ACROSS THE REGION ASSOCIATED WITH A DEEP AND COLD TROUGH ACROSS THE GREAT LAKES REGION. THE AFOREMENTIONED SURFACE LOW WILL QUICKLY LIFT NORTHEASTWARD IN THE LEE OF THE APPALACHIANS ALONG A SHARPENING FRONTAL ZONE. DEEP MOISTURE WILL INCREASE ACROSS THE AREA AND A QUICK SHOT OF UPPER JET DYNAMICS WILL SPREAD IN THROUGH THE DAY ON MONDAY. MODELS CONTINUE TO LOOK WET FOR MONDAY AND POPS HAVE BEEN RAISED TO LIKELY. THE DYNAMICS WITH THIS SYSTEM CONTINUE TO LOOK STRONG...BUT THE POTENTIAL FOR SURFACE DESTABILIZATION IS LIMITED. TEMPS BEHIND THE WARM FRONT WILL WARM INTO THE 70 DEGREE RANGE BUT IT LOOKS AS THOUGH INSTABILITY WILL BE LOW ENOUGH TO PRECLUDE A SEVERE THREAT. THERE COULD STILL BE AN ISOLATED EMBEDDED THUNDERSTORM SO THE FORECAST STILL FEATURES ISOLATED THUNDER MONDAY AFTERNOON. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... OVERALL CONFIDENCE IN THE LONG TERM FORECAST PERIOD IS QUITE HIGH AND THE MAIN STORY WILL BE THE IMPRESSIVE SHOT OF COLD AIR THAT IS PROGGED TO IMPACT THE SOUTHEAST CONUS. COLD ADVECTION WILL BEGIN MONDAY NIGHT IN THE WAKE OF THE STRONG COLD FRONT AND TEMPERATURES LOOK VERY CHILLY TUESDAY ONWARD. CONFIDENCE IS INCREASING THAT THE COLDEST AIR OF THE SEASON THUS FAR WILL INFILTRATE THE AREA TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. A HARD ADVECTIVE FREEZE WILL LIKELY IMPACT THE FORECAST AREA TUESDAY NIGHT WITH LOWS IN THE MID TO UPPER 20S JUST ABOUT EVERYWHERE OUTSIDE THE BEACHES. HIGHS ON WEDNESDAY WILL THEN BE IMPRESSIVELY CHILLY WITH RAW THICKNESS VALUES ONLY SUPPORTING HIGHS IN THE LOW 40S. THE FORECAST HAS BEEN TRENDED LOWER AND FEATURES UPPER 40S FOR NOW. THEN WEDNESDAY NIGHT...ANOTHER HARD FREEZE WILL OCCUR AS EXCELLENT RADIATIONAL COOLING CONDITIONS SET UP WITH THE SURFACE HIGH POSITIONED RIGHT OVER SOUTH GEORGIA. OVERALL...IT APPEARS TEMPERATURES WILL BE NEAR RECORD LOWS AND RECORD LOW MAX VALUES FOR TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/... A LARGE AREA OF MVFR STRATUS CONTINUES TO OOZE TO THE SOUTH THIS MORNING IN ASSOCIATION WITH A WEAK TROUGH TRAILING THE COLD FRONT. THE LATEST HRRR MODEL SHOWS THIS CLOUD DECK STAYING WITH US IN SOUTHERN SC THROUGH THE MIDDLE OF THE AFTERNOON THOUGH CURRENT TRENDS INDICATE THE CEILING WILL LIFT TO VFR BY EARLY AFTERNOON. MEANWHILE THE LEADING EDGE WILL OVERSPREAD THE SAV TERMINAL BY 16Z AND PERSIST INTO EARLY AFTERNOON BEFORE SCATTERING OUT. ALL INDICATIONS ARE THAT THE CLOUDS WILL BE OUT OUR HAIR BY SUNSET WITH VFR CONDITIONS THEREAFTER. EXTENDED AVIATION OUTLOOK...VFR SATURDAY...THEN INCREASING CHANCES FOR FLIGHT RESTRICTIONS IN DEVELOPING CEILINGS LATE SATURDAY NIGHT AND SUNDAY. PREVAILING VFR CONDITIONS WILL RETURN BEHIND A DEPARTING LOW PRESSURE SYSTEM AND COLD FRONT MONDAY NIGHT AND INTO TUESDAY. && .MARINE... THE PRELIMINARY BLAST OF COLD ADVECTION HAS SURGED THROUGH THE WATERS EARLY THIS MORNING. SURFACE OBS INDICATE WINDS HAVE REMAINED BELOW SMALL CRAFT ADVISORY CRITERIA IN ALL NEARSHORE WATERS OVERNIGHT AND THIS MORNING. HOWEVER SOME GUSTS TO 25 KT HAVE LIKELY OCCURRED OVER THE OFFSHORE GA WATERS WHERE WARMER WATER EXISTS. THE LATEST HIGH-RES MODEL DATA INDICATES WE COULD SEE SOME 25 KT GUSTS OVER THE CHARLESTON NEARSHORE WATERS LATE THIS AFTERNOON INTO TONIGHT SO WE PUSHED BACK THE SMALL CRAFT ADVISORY START TIME FOR THOSE WATERS UNTIL 5 PM...AND DROPPED THE ADVISORY FOR THE REMAINDER OF THE NEARSHORE WATERS. SATURDAY THROUGH TUESDAY...HIGH PRESSURE WILL SLIDE BY TO THE NORTH OF THE REGION ON SATURDAY. CONDITIONS WILL BE NEAR SMALL CRAFT ADVISORY THRESHOLDS FOR THE NEAR SHORE WATERS EARLY ON SATURDAY BUT WILL THEN DIMINISH AS THE PRESSURE GRADIENT RELAXES A BIT. CONDITIONS WILL STILL BE SUPPORTIVE OF AN ADVISORY FOR THE OUTER GEORGIA WATERS UNTIL SATURDAY EVENING. A COASTAL TROUGH IS EXPECTED TO DEVELOP LATE SATURDAY NIGHT AND SUNDAY ACROSS THE WATERS WITH INCREASING PRECIPITATION CHANCES. THE FLOW WILL THEN TURN MORE SOUTHERLY SUNDAY NIGHT AS A WARM FRONT LIFTS THROUGH THE WATERS IN ADVANCE OF A DEVELOPING LOW PRESSURE SYSTEM AND COLD FRONT TO THE WEST. MARGINAL SMALL CRAFT CONDITIONS COULD DEVELOP IN THE INCREASING SOUTHERLY FLOW MONDAY...BUT APPEAR MORE LIKELY IN THE COLD ADVECTION NORTHWEST FLOW BEHIND THE FRONT MONDAY NIGHT AND TUESDAY. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR GAZ087-088-099>101-114>116-118-137-138. SC...FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR SCZ040-042>045-047>052. MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO NOON EST SATURDAY FOR AMZ350. SMALL CRAFT ADVISORY UNTIL 7 PM EST SATURDAY FOR AMZ374. && $$ NEAR TERM...JRL SHORT TERM...BSH LONG TERM...BSH AVIATION...JRL MARINE...BSH/JRL
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
921 AM PST FRI NOV 14 2014 .SYNOPSIS...PARTLY CLOUDY AND DRY CONDITIONS ARE EXPECTED THROUGH THE WEEKEND WITH SEASONABLE TEMPERATURES. SOME DRIER OFFSHORE WINDS MAY DEVELOP SUNDAY AND MONDAY LEADING TO A WARMING AND DRYING TREND AS HIGH PRESSURE BUILDS. THE NEXT PACIFIC FRONT LOOKS TO ARRIVE LATE TUESDAY INTO WEDNESDAY WITH A CHANCE OF SOME LIGHT RAIN. && .DISCUSSION...AS OF 9:20 AM PST FRIDAY...SATELLITE IMAGERY SHOWS PATCHY CLOUDS AND/OR FOG OVER PORTIONS OF THE AREA. SURFACE OBSERVATIONS STILL INDICATE A FEW AREAS REPORTING DENSE FOG...MAINLY JUST SANTA ROSA. THE DENSE FOG ADVISORY FOR THE NORTH BAY VALLEYS WAS ALLOWED TO EXPIRE AT 9 AM. MOSTLY SUNNY CONDITIONS TODAY WILL ALLOW HIGH TEMPS TO REACH THE MID TO UPPER 60S IN MOST AREAS. THERE COULD BE A REPEAT OF FOG OVERNIGHT TONIGHT...OTHERWISE IT IS EXPECTED TO BE A MILD WEEKEND WITH DRY CONDITIONS AND LIGHT OFFSHORE FLOW BY SUNDAY MORNING. THE LATEST RUN OF THE NAM12 GIVES 30 KNOT WINDS AT THE 925 MB LEVEL TO AREAS IN THE NORTH AND EAST BAY...MAINLY ACROSS THE HIGHEST TERRAIN THERE. THE OFFSHORE GRADIENT IS PROGGED TO TIGHTEN BY SUNDAY AFTERNOON AND USHER IN A MUCH DRIER AIR MASS WITH HUMIDITY VALUES DROPPING BY MONDAY. EVEN WITH OFFSHORE FLOW...THE COLD AIR OVER THE GREAT BASIN WILL RESULT IN HIGH TEMPERATURES REMAINING IN THE 70S ACROSS THE DISTRICT THROUGH EARLY NEXT WEEK. BY TUESDAY THE SURFACE FLOW IS FORECAST TO SWITCH TO ONSHORE AS A PACIFIC SYSTEM APPROACHES THE COAST. RAIN CHANCES WITH THIS FIRST SYSTEM ARE PROGGED FOR MAINLY THE NORTH BAY...BUT THERE ARE DIFFERENCES IN MODEL OUTPUT. LATER NEXT WEEK THERE ARE PERHAPS BETTER CHANCES FOR RAIN AS A SERIES OF STORMS TAKES AIM AT THE WEST COAST. && .AVIATION...AS OF 4:00 AM PST FRIDAY...TRICKY FORECAST THIS MORNING WITH SEVERAL FACTORS AT PLAY. SATELLITE IMAGERY SHOWS HIGH CLOUDS HAVE NOW PUSHED SOUTH OF ALL TAF SITES RESULTING IN A RACE AGAINST TIME FOR FOG TO DEVELOP BEFORE SUNRISE. IN THE NORTH BAY VALLEYS...INCLUDING KSTS AND KAPC...CLEARING SKIES AND LIGHT WINDS CREATED A FAVORABLE ENVIRONMENT FOR FOG DEVELOPMENT AND VISBYS ARE 1/4SM OR LESS. AS OF LAST OBSERVATION... KOAK IS REPORTING CLEAR SKIES AFTER LOW CLOUDS DISSIPATED ... HOWEVER GOES-W CIG PROBABILITY PRODUCT INDICATES LOW CLOUDS ARE STILL IN THE VICINITY. KOAK/EAST BAY COULD BE THE NEXT AREA OF FOG DEVELOPMENT IF WINDS REMAIN CALM AND SKIES REMAIN CLEAR IN THE VICINITY. LEAST WORRIED ABOUT FOG AT KSFO...HOWEVER CAN NOT RULE IT OUT WITH HRRR HINTING AT DEVELOPMENT BETWEEN 14-16Z. GRADUAL CLEARING OF LOW CIGS EXPECTED LATE FRIDAY MORNING WITH VFR CONDITIONS IN MOST AREAS BY MIDDAY. PATCHY LOW CLOUDS MAY PERSIST WELL INTO THE AFTERNOON HOURS. OVERALL CONFIDENCE IS LOW AT KSFO/KOAK... AND MEDIUM TO HIGH ELSEWHERE. VICINITY OF KSFO... MVFR WITH LOCAL IFR CIGS AND PATCHY FOG POSSIBLE THROUGH FRIDAY MORNING...MAINLY ON EAST SIDE OF SF BAY BETWEEN 14-17Z FRI. LOW CIGS WILL LIKELY CLEAR BETWEEN 18-20Z FRIDAY MORNING. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...MVFR CIGS WITH BRIEF PATCHY IFR CIGS POSSIBLE THROUGH EARLY MORNING. VFR CONDITIONS FORECAST TO RETURN BY LATE MORNING. LIGHT WINDS. && .MARINE...AS OF 08:20 AM PST FRIDAY...NORTHWEST WINDS WILL PREVAIL ALONG THE CENTRAL COAST TODAY THROUGH THE WEEKEND. A MODERATE WEST TO NORTHWEST SWELL WILL CONTINUE TO IMPACT THE COASTAL WATERS THROUGH THE WEEKEND AS WELL. SOUTHERLY WINDS WILL RETURN EARLY NEXT WEEK AS A STORM SYSTEM APPROACHES THE REGION. && .MTR WATCHES/WARNINGS/ADVISORIES... && $$ PUBLIC FORECAST: SIMS AVIATION: DRP MARINE: MM VISIT US AT WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS PUEBLO CO
332 PM MST FRI NOV 14 2014 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 232 PM MST FRI NOV 14 2014 ...ACTIVE WEATHER CONTINUES... CURRENT WATER VAPOR IMAGERY AND UPPER AIR ANALYSIS INDICATING MODERATE TO STRONG WESTERLY FLOW ALOFT ACROSS THE REGION WITH ANOTHER EMBEBBED SHORT WAVE TRANSLATING ACROSS THE GREAT BASIN AND INTO WESTERN COLORADO. REGIONAL SATELLITE AND RADAR DATA INDICATING A GOOD SLUG OF MOISTURE MOVING INTO WESTERN COLORADO ALONG WITH A FEW LIGHTNING STRIKES ACROSS SOUTHEASTERN UTAH AT THIS TIME. TEMPERATURES AS OF 2 PM INDICATING SHALLOW COLD AIRMASS PERSISTING ACROSS SOUTHERN EL PASO COUNTY AND THE LOWER ARKANSAS RIVER VALLEY FROM CANON CITY TO LAMER...WITH TEMPS IN THE 20S TO LOWER 30S AT THIS TIME. ELSEWHERE ACROSS THE AREA...TEMPS HAVE WARMED INTO THE 40S TO LOWER 50S WITH MAINLY 20S AND 30S ACROSS THE CONTDVD. TONIGHT...MODELS CONTINUE TO BRING WAVE ACROSS THE AREA WITH MODERATE TO HEAVY SNOWFALL EXPECTED ACROSS THE CENTRAL AND SOUTHWEST MTS AND ACROSS THE HIGHER ELEVATIONS OF THE SANGRE DE CRISTO MTS THROUGH EARLY SATURDAY MORNING. CURRENT WINTER WEATHER HIGHLIGHTS LOOK ON TRACK WITH 4 TO 8 INCHES POSSIBLE OVERNIGHT. MODELS...TO A VARYING DEGREE...CONTINUE TO INDICATE A BAND OF PRECIPITATION... MOVING INTO THE LA GARITA MTS AT THIS TIME...CONTINUING TO SPREAD EAST ACROSS THE NORTHERN SAN LUIS VALLEY AND ACROSS THE LOWER ARKANSAS RIVER THROUGH THE LATE EVENING AND OVERNIGHT HOURS. WHILE THE 18Z NAM LOOKS HEAVY HANDED IN QPF...RAP AND HRRR HAVE A SIMILAR SET UP AND HAVE INCREASED POPS ACROSS THIS AREA TO MATCH KEEPING ACCUMULATIONS OF AN INCH OR LESS AT THIS TIME. HOWEVER...WILL NEED TO CONTINUE TO MONITOR THE DEVELOPMENT OF THIS BAND AS THE 18Z NAM IS GIVING UP TO 3 INCHES ACROSS THE LOWER ARK VALLEY TONIGHT. WITH EXPECTED CLOUD COVER...EXPECTING LOWS TO BE MAINLY IN THE 20S ACROSS THE AREA. TOMORROW...MODELS CONTINUE TO DIFFER ON TIMING OF THE NEXT SLUG OF ARCTIC AIR TO INVADE EASTERN COLORADO...ESPECIALLY ITS ASSOCIATED PRECIPITATION FIELD. NAM AND EC CONTINUE TO BE SLOWER WITH THE UPPER TROUGH MOVING ACROSS THE ROCKIES WITH THE GFS REMAINING FASTER. AT ANY RATE...HAVE PLAYED THE TIMING OF THE ARCTIC FRONT ACROSS THE PALMER DVD AROUND 18Z...THOUGH HAVE DELAYED ONSET OF PRECIPITATION INTO THE LATE AFTERNOON. GUSTY NORTH TO NORTHEAST WINDS OF 20 TO 30 MPH TO ANNOUNCE THE ARRIVAL OF THE FRONT...WHICH MAY BE ENOUGH TO BRIEFLY MIX OUT THE SHALLOW COLD AIRMASS IN PLACE ACROSS THE LOWER ARK VALLEY...BEFORE TEMPS COOL AGAIN BEHIND THE FRONT. NEEDLESS TO SAY...FORECASTING HIGH TEMPERATURES TOMORROW WILL AGAIN BE A CHALLENGE. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 232 PM MST FRI NOV 14 2014 ...SNOW CONTINUES SATURDAY NIGHT THROUGH SUNDAY... UPPER TROF WILL DROP IN FROM THE NORTHWEST SATURDAY NIGHT BRINGING A HEALTHY BOUT OF UPPER FORCING ACROSS THE AREA IS IT DROPS TO THE SOUTHEAST. THERE ARE STILL SOME TIMING DIFFERENCES IN THE MODELS WITH THE ONSET OF THE PRECIPITATION...ESPECIALLY FOR THE SOUTHEAST MTS/PLAINS. GFS IS A TOUCH FASTER WITH THE SOUTHWARD PROGRESSION OF THE UPPER TROF...WHICH MAY BE THE REASON IT IS TRENDING FASTER WITH THE ONSET OF PRECIPITATION VS THE SLOWER NAM12 AND ECMWF. FRONT WILL HAVE ALREADY BLASTED THROUGH SOUTHEAST CO BY 00Z SUN...AND GIVEN ITS ARCTIC ORIGIN...THIS TIMING LOOKS REASONABLE. HOWEVER...WITH THE UPPER FORCING IS STILL WELL OFF TO THE NORTH DURING THIS TIME PERIOD...AND A SLOWER TIMING TO THE ONSET OF PRECIPITATION...ESP FOR THE SE PLAINS...SEEMS MORE REASONABLE. NORTHEAST UPSLOPE BEHIND THE FRONT IS RATHER SHALLOW (BELOW H7) BUT AS UPPER TROF DROPS IN FROM THE NORTHWEST...THERE WILL BE A PERIOD OF UPGLIDE OVER THE COLD DOME DURING THE EVENING AND OVERNIGHT HOURS. THE GFS SHOWS SOME PRETTY GOOD DIV-Q...THE CORE OF WHICH PASSES ACROSS UT/THE 4 CORNERS REGION/SRN CO/AND NORTHERN NM. SO ALTHOUGH UPSLOPE IS SHALLOW FOR THE SOUTHEAST MTS...AND NOT THE BEST FOR THE SOUTHWEST MOUNTAINS WITH FLOW ALOFT MORE WESTERLY (INSTEAD OF THE MORE FAVORABLE SOUTHWEST DIRECTION)...HAVE SEEN THESE DYNAMIC SYSTEMS PRODUCE WIDESPREAD MODERATE TO HEAVY SNOWFALL AMOUNTS. WITH TIMING OF THE FORCING EXITING SOUTHERN CO AROUND OR SHORTLY AFTER 12Z SUN...PLAN TO KEEP THE HEADLINE TIMING FOR THE CONTINENTAL DIVIDE AS IS FOR NOW. HOWEVER...IF MOISTURE DIMINISHES RAPIDLY ENOUGH BEHIND THE TROF...ITS POSSIBLE THAT THE SNOW MAY DECREASE A BIT SOONER FARTHER NORTH ACROSS THE SAWATCH AND MOSQUITO RANGES. GIVEN THE INCONSISTENCIES BETWEEN MODELS...WILL LET LATER SHIFTS REFINE THE TIMING AS NEED BE. ADDITIONAL SNOWFALL AMOUNTS IN THE 4 TO 8 INCH RANGE LOOKS REASONABLE ALONG THE CONTINENTAL DIVIDE SAT NIGHT GIVEN THE PROBABILITY FOR 20+/1 LIQUID/SNOW RATIOS. STILL SOME UNCERTAINTY FOR SNOWFALL AMOUNTS ACROSS THE SOUTHEAST MOUNTAINS...AS THE GFS IS HEAVIER WITH QPF ACROSS THE PIKES PEAK REGION VS THE DRIER NAM12. HUNCH IS THAT SOUTHEAST MOUNTAINS AND PORTIONS OF THE I-25 CORRIDOR MAY NEED AN ADVISORY SAT NIGHT...WITH THE WETS AND SANGRES LIKELY TO SEE SOMEWHERE IN THE 3-8 INCH RANGE. TELLER AND EL PASO COUNTIES STILL VERY MUCH IN THE AIR WITH NAM SUGGESTING ONLY AN INCH OR TWO SAT NIGHT...WHILE GFS HAS 2 TO NEARLY 4 INCHES. GIVEN THE TRACK OF THE STRONGER FORCING ALOFT...IT DOES MAKE SENSE THAT THE LIGHTER NAM12 AMOUNTS COULD BE MORE REASONABLE. SUSPECT THAT SOME BANDING OF SNOW ALONG/SOUTH OF THE ARKANSAS RIVER WILL EXTEND EASTWARD ACROSS THE SOUTHEAST PLAINS...BUT SNOWFALL AMOUNTS AT THIS TIME APPEAR TO STAY BELOW ADVISORY LEVELS...PERHAPS 1-3" RANGE. AGAIN GIVEN THE COLD AIRMASS WITH THIS EVENT...IT SHOULD BE ANOTHER DRY FLUFFY SNOW EVENT. THE DIFFERENCE THIS TIME WILL BE THAT THE ROAD SURFACES WILL START OUT COLDER GIVEN OUR PREVIOUS COLD OUTBREAK. THIS COULD LIMIT THE ICING FACTOR SOME DEPENDING ON ASPHALT TEMPERATURES SATURDAY AFTERNOON. SNOW WILL END FROM NORTH TO SOUTH DURING THE MORNING ON SUNDAY...AND SNOW COVER WILL LIKELY KEEP TEMPERATURES FROM WARMING MUCH. HAVE DROPPED HIGHS A FEW DEGREES FROM THE CONSENSUS GRIDS...WHICH PUTS THEM CLOSER TO THE COLDER SIDE OF GUIDANCE VALUES. FORECAST DRIES OUT FOR THE REMAINDER OF THE EXTENDED. ANOTHER SURFACE HIGH DESCENDS THROUGH THE PLAINS WITH SOME UNCERTAINTIES AS TO HOW FAR WEST THE CORE OF COLD AIR ASSOCIATED WITH IT WILL GET. NAM12 AND EC ARE SEVERAL DEGREES COOLER WITH H7 TEMPS ACROSS THE PLAINS VS THE WARMER GFS MONDAY AFTERNOON...WHICH PUTS HIGH TEMPERATURES IN QUESTION ACROSS THE PLAINS. CURRENT GRIDS ARE CARRYING MID 20S TO AROUND 30...BUT THESE MAY NEED TO BE COOLED OFF EVEN FURTHER DEPENDING ON HOW THIS EVOLVES. NORTHERLY FLOW ALOFT GRADUALLY SHIFTS TO A MORE WESTERLY DIRECTION WHICH SHOULD BRING SOME MODERATING TEMPERATURES THROUGH MID TO LATE WEEK. ANOTHER PACIFIC SYSTEM MAY CUT THROUGH THE WESTERN U.S. UPPER RIDGE TOWARDS FRIDAY. FORECAST WILL CARRY GENERALLY DRY CONDITIONS UNTIL FRIDAY WITH TEMPERATURES WARMING BUT STILL REMAINING BELOW NORMAL. -KT && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 232 PM MST FRI NOV 14 2014 MAINLY VFR CONDITIONS EXPECTED AT TAF SITES THROUGH THE DAY TOMORROW. WILL SEE INCREASING SHOWERS ACROSS THE HIGHER TERRAIN THROUGH THE EVENING WITH A FEW OF THE MODELS INDICATING A BAND OF PRECIPITATION SPREADING OFF THE HIGHER TERRAIN AND OUT ACROSS THE LOWER ARKANSAS RIVER THIS EVENING. STILL NOT SURE ON THE EXACT LOCATION OF THIS DEVELOPMENT...THOUGH WILL GO WITH A PERIOD OF MFVR AND SNOW SHOWERS FOR PUB FROM 02Z THROUGH 06Z...WHILE KEEPING VCSH AT COS AND ALS. THE NEXT ARCTIC FRONT IS POSED TO MOVE ACROSS THE EASTERN PLAINS LATE MORNING AND AFTERNOON...WITH GUSTY NORTH TO NORTHEAST WINDS OF 20 TO 30 MPH AND LOWERING CIGS EXPECTED AT COS AND PUB AFT 18Z SAT. && .PUB WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 5 AM MST SUNDAY FOR COZ058-060-066- 068. WINTER WEATHER ADVISORY UNTIL 5 AM MST SATURDAY FOR COZ073-075. && $$ SHORT TERM...MW LONG TERM...KT AVIATION...MW
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1239 PM MST FRI NOV 14 2014 .UPDATE... ISSUED AT 1239 PM MST FRI NOV 14 2014 UPDATED FOR CURRENT OBSERVATIONAL DATA AND FORECAST TRENDS...WHICH HAS SHALLOW COLD AIRMASS HANGING ACROSS SOUTHERN PORTIONS OF EL PASO COUNTY AND ESPECIALLY THE LOWER ARKANSAS RIVER VALLEY THROUGH THE AFTERNOON. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 400 AM MST FRI NOV 14 2014 ...MAX TEMPS TODAY ON THE PLAINS WILL SHOW LOTS OF VARIABILITY... ...SAN JUANS TO GET POUNDED THIS EVENING... CURRENTLY... AT 2 AM...TEMPS THIS MORNING SHOWING QUITE A BIT OF VARIABILITY ACROSS THE REGION. THE ARCTIC AIR HAS ALREADY BEGUN TO RETREAT AS ELEVATIONS GENERALLY ABOVE 6500 FEET ARE IN THE (RELATIVELY) WARMER AIR. AS AN EXAMPLE...AREAS OF N EL PASO COUNTY ARE IN THE TEENS AND 20S WHILE KCOS WAS 3F. AREAS JUST WEST OF WALSENBURG AND WEST OF KTAD WERE IN THE 20S AND 30S WHILE COLORADO CITY AND TRINIDAD WERE 2 AND 7F RESPECTIVELY. IN THE MTNS AND VALLEYS IT WAS RELATIVELY WARM WITH 2 AM TEMPS IN THE 20S TO LOWER 30S. SNOW WAS FALLING ACROSS THE CONTDVD AND ACROSS THE SANGRE DE CRISTO MTNS. TODAY... I AM QUITE CONFIDENT WE ARE GOING TO SEE QUITE A BIT OF VARIABILITY IN MAX TEMPS TODAY OVER THE PLAINS...I AM JUST UNCERTAIN ON THE MAGNITUDE OF THE VARIABILITY. HRRR GUIDANCE SHOWS AREAS OF THE LWR ARK RVR VLY FROM KPUB EASTWARD TO KLAA NOT GETTING OUT OF THE TEENS WHILE AREAS N AND S OF THE RIVER WILL GET INTO THE 30S AND 40S. FOR NOW I AM NOT GOING TO GO THAT EXTREME...ALTHOUGH I PLAN TO KEEP AREAS OF THE LOWER ARK RVR VALLEY MUCH COOLER THAN THE SURROUNDING PLAINS. FOR NOW PLAN TO HAVE AREAS SUCH AS KPUB...KLHX AND KLAA IN THE UPPER 20S TO LOWER 30S WHILE KCOS WILL BE IN THE UPPER 30S...AIR FORCE AROUND 40...CANON CITY...COLORADO CITY...WALSENBURG AND TRINIDAD WILL BE IN THE MID 40S. I WOULD NOT BE TOO SURPRISED IF PUEBLO WEST WAS IN THE MID 40S WHILE KPUB WILL BE IN THE LOWER 30S. THE WARMEST AREA ACROSS THE REGION TODAY WILL LIKELY BE THE SAN LUIS VALLEY WHERE KALS WILL LIKELY BE IN THE LOWER 50S. AS FOR THE MTNS...ALTHOUGH A WINTER STORM WARNING IS IN EFFECT ALL DAY FOR THE CONTDVD REGION...I EXPECT SNOW TO DECREASE SIGNIFICANTLY LATER THIS MORNING ACROSS THE DIVIDE (SOME AREAS MAY SEE THE SNOW STOP COMPLETELY). THE SNOW WILL LIKELY NOT START TO RAMP UP AGAIN UNTIL MID TO LATER AFTERNOON ACROSS THE DIVIDE. HOWEVER...ONCE IT RAMPS UP AGAIN...IT WILL REALLY RAMP UP...ESPECIALLY ACROSS THE SAN JUANS (SEE TONIGHT). TONIGHT... THE SAN JUANS ARE LIKELY GOING TO GET POUNDED ESPECIALLY THIS EVENING. SNOWFALL RATES WILL LIKELY EXCEED 2" PER HOUR FOR AT LEAST A FEW HOURS THIS EVENING AS THE BEST FORCING MOVES ACROSS. ALL GUIDANCE INDICATES THIS. A FEW LTG FLASHES ARE LIKELY THIS EVENING AS THIS FORCING MOVES ACROSS (SEE SPC DAY1 GUIDANCE). THE C MTNS WILL ALSO SEE PERIODS OF HEAVY SNOW TONIGHT. IN ADDITION...HAVE ADDED HILITES FOR THE SANGRES AS THEY WILL LIKELY SEE 4-8" TONITE. THE BEST CHANCE FOR THE SAN LUIS VALLEY TO SEE PRECIP WILL BE THIS EVENING. LOCALLY 1-2" ACCUMS WILL BE POSSIBLE...ESPECIALLY AREAS CLOSER TO THE MOUNTAINS. THE PLAINS WILL LIKELY SEE SOME PRECIP TONIGHT. OVERALL...GUIDANCE HAS BACKED OFF SOME AND I HAVE REDUCED POPS OVER THE PLAINS. THE BEST CHANCE OF ANY ACCUM PRECIP STILL APPEARS TO BE OVER THE FAR EASTERN PLAINS...ALTHOUGH IF A SNOW BAND DEVELOPS...(AS SOME GUIDANCE IS HINTING AT)...LOCALLY 1-2" ACCUMS WILL BE POSSIBLE. THE PLAINS WILL HAVE TO BE WATCHED CAREFULLY LATE TODAY TO SEE IF ANY BANDED PRECIP DEVELOPS. /HODANISH .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 400 AM MST FRI NOV 14 2014 ...A COUPLE MORE SYSTEMS TO IMPACT THE AREA THROUGH THE WEEKEND... THE WINTER STORM WARNING WILL REMAIN IN EFFECT FOR THE SAN JUAN AND LA GARITA MOUNTAINS...CONTINENTAL DIVIDE...THROUGH 5 AM SUNDAY. HOWEVER...SOME CONCERN THAT THERE WILL BE A DEFINITE LULL IN THE SNOWFALL SATURDAY AFTERNOON AS THE PACIFIC SHORTWAVE MOVES OUT OF COLORADO. NEXT TROF DROPPING SOUTH OF CANADA WILL IMPACT THE AREA SATURDAY AFTERNOON AND SATURDAY NIGHT. THIS TROF WILL HAVE A WIDER IMPACT ON THE FORECAST AREA AS TEMPERATURES COOL DURING THE DAY SATURDAY WITH FRONT MOVING THROUGH THE PLAINS AND A BAND OF SNOW SETTING UP ALONG THE I-25 CORRIDOR AND THE SOUTHEAST PLAINS SATURDAY NIGHT. GFS HAS MOST OF THE PRECIPITATION/SNOWFALL ALONG THE EAST SLOPES OF THE RAMPARTS AND SANGRES. HUERFANO AND LAS ANIMAS COUNTIES MAY SEE THE BULK OF THE SNOWFALL WITH THIS SYSTEM OVERNIGHT SATURDAY WITH A BAND OF SNOW STRETCHING INTO BACA COUNTY. LATER SHIFTS MAY HAVE TO BALANCE THE WINTER STORM HIGHLIGHTS...MAYBE DOWNGRADING THE WINTER STORM WARNING FOR THE CONTINENTAL DIVIDE AS THE SNOWFALL DIMINISHES...AND AN EYE TOWARD A HIGHLIGHT FOR THE SOUTHERN I-25 CORRIDOR AND SOUTHERN PLAINS. ECMWF AND NAM NOT AS BULLISH ON THE QPF FOR THE SAME AREAS...SO SOME UNCERTAINTY REMAINS. HAVE TRIED TO TIME THE FRONTAL PASSAGE ON THE PLAINS AND FALLING TEMPERATURES DURING THE DAY SATURDAY. TROF CONTINUES TO MOVE SOUTH SUNDAY WITH NORTHWESTERLY FLOW ALOFT EXPECTED TO BRING ANOTHER FRONTAL BOUNDARY THROUGH THE EASTERN PLAINS MONDAY NIGHT...THOUGH TEMPERATURES WILL NOT FALL AS MUCH BEHIND THIS FRONT. SNOW SHOWERS ARE POSSIBLE IN THE CENTRAL MOUNTAINS WITH THIS NORTHWEST FLOW. GENERALLY DRY AND WARMER CONDITIONS ARE EXPECTED TUESDAY THROUGH AT LEAST THURSDAY WITH WESTERLY FLOW ALOFT AND WEAK LEE TROF DEVELOPING AT THE SURFACE. WEATHER PATTERN REMAINS ACTIVE TO OUR NORTH AND WEST AND EXTENDED MODELS DO SHOW ENERGY MOVING INTO THE NORTH CENTRAL MOUNTAINS THURSDAY. STARK && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1055 AM MST FRI NOV 14 2014 MAINLY VFR CONDITIONS EXPECTED AT COS...PUB AND ALS OVER THE NEXT 24 HOURS. WILL SEE INCREASING SHOWERS ACROSS THE HIGHER TERRAIN THROUGH THE AFTERNOON WITH A FEW OF THE MODELS INDICATING A BAND OF PRECIPITATION SPREADING OFF THE HIGHER TERRAIN AND OUT ACROSS THE LOWER ARKANSAS RIVER THIS EVENING. NOT SURE OF THE LOCATION OF THE SAID BAND OF SHOWERS...AND HAVE KEPT VCSH IN TAFS THROUGH 06Z SAT ATTM. IF THIS BAND DOES SET UP...COULD SEE MVFR AND LOCAL IFR CONDITIONS WITH UP TO AN INCH OF SNOW ACCUMS...ESPECIALLY AT ALS AND PUB. THE NEXT ARCTIC FRONT IS POSED TO MOVE ACROSS THE EASTERN PLAINS LATE MORNING AND AFTERNOON...JUST OUT OF THIS TAF PERIOD...WITH GUSTY NORTH TO NORTHEAST WINDS AND LOWERING CIGS EXPECTED AT COS AND PUB AFT 18Z SAT. && .PUB WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 5 AM MST SUNDAY FOR COZ058-060-066- 068. WINTER WEATHER ADVISORY UNTIL 5 AM MST SATURDAY FOR COZ073-075. && $$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1054 AM MST FRI NOV 14 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 400 AM MST FRI NOV 14 2014 ...MAX TEMPS TODAY ON THE PLAINS WILL SHOW LOTS OF VARIABILITY... ...SAN JUANS TO GET POUNDED THIS EVENING... CURRENTLY... AT 2 AM...TEMPS THIS MORNING SHOWING QUITE A BIT OF VARIABILITY ACROSS THE REGION. THE ARCTIC AIR HAS ALREADY BEGUN TO RETREAT AS ELEVATIONS GENERALLY ABOVE 6500 FEET ARE IN THE (RELATIVELY) WARMER AIR. AS AN EXAMPLE...AREAS OF N EL PASO COUNTY ARE IN THE TEENS AND 20S WHILE KCOS WAS 3F. AREAS JUST WEST OF WALSENBURG AND WEST OF KTAD WERE IN THE 20S AND 30S WHILE COLORADO CITY AND TRINIDAD WERE 2 AND 7F RESPECTIVELY. IN THE MTNS AND VALLEYS IT WAS RELATIVELY WARM WITH 2 AM TEMPS IN THE 20S TO LOWER 30S. SNOW WAS FALLING ACROSS THE CONTDVD AND ACROSS THE SANGRE DE CRISTO MTNS. TODAY... I AM QUITE CONFIDENT WE ARE GOING TO SEE QUITE A BIT OF VARIABILITY IN MAX TEMPS TODAY OVER THE PLAINS...I AM JUST UNCERTAIN ON THE MAGNITUDE OF THE VARIABILITY. HRRR GUIDANCE SHOWS AREAS OF THE LWR ARK RVR VLY FROM KPUB EASTWARD TO KLAA NOT GETTING OUT OF THE TEENS WHILE AREAS N AND S OF THE RIVER WILL GET INTO THE 30S AND 40S. FOR NOW I AM NOT GOING TO GO THAT EXTREME...ALTHOUGH I PLAN TO KEEP AREAS OF THE LOWER ARK RVR VALLEY MUCH COOLER THAN THE SURROUNDING PLAINS. FOR NOW PLAN TO HAVE AREAS SUCH AS KPUB...KLHX AND KLAA IN THE UPPER 20S TO LOWER 30S WHILE KCOS WILL BE IN THE UPPER 30S...AIR FORCE AROUND 40...CANON CITY...COLORADO CITY...WALSENBURG AND TRINIDAD WILL BE IN THE MID 40S. I WOULD NOT BE TOO SURPRISED IF PUEBLO WEST WAS IN THE MID 40S WHILE KPUB WILL BE IN THE LOWER 30S. THE WARMEST AREA ACROSS THE REGION TODAY WILL LIKELY BE THE SAN LUIS VALLEY WHERE KALS WILL LIKELY BE IN THE LOWER 50S. AS FOR THE MTNS...ALTHOUGH A WINTER STORM WARNING IS IN EFFECT ALL DAY FOR THE CONTDVD REGION...I EXPECT SNOW TO DECREASE SIGNIFICANTLY LATER THIS MORNING ACROSS THE DIVIDE (SOME AREAS MAY SEE THE SNOW STOP COMPLETELY). THE SNOW WILL LIKELY NOT START TO RAMP UP AGAIN UNTIL MID TO LATER AFTERNOON ACROSS THE DIVIDE. HOWEVER...ONCE IT RAMPS UP AGAIN...IT WILL REALLY RAMP UP...ESPECIALLY ACROSS THE SAN JUANS (SEE TONIGHT). TONIGHT... THE SAN JUANS ARE LIKELY GOING TO GET POUNDED ESPECIALLY THIS EVENING. SNOWFALL RATES WILL LIKELY EXCEED 2" PER HOUR FOR AT LEAST A FEW HOURS THIS EVENING AS THE BEST FORCING MOVES ACROSS. ALL GUIDANCE INDICATES THIS. A FEW LTG FLASHES ARE LIKELY THIS EVENING AS THIS FORCING MOVES ACROSS (SEE SPC DAY1 GUIDANCE). THE C MTNS WILL ALSO SEE PERIODS OF HEAVY SNOW TONIGHT. IN ADDITION...HAVE ADDED HILITES FOR THE SANGRES AS THEY WILL LIKELY SEE 4-8" TONITE. THE BEST CHANCE FOR THE SAN LUIS VALLEY TO SEE PRECIP WILL BE THIS EVENING. LOCALLY 1-2" ACCUMS WILL BE POSSIBLE...ESPECIALLY AREAS CLOSER TO THE MOUNTAINS. THE PLAINS WILL LIKELY SEE SOME PRECIP TONIGHT. OVERALL...GUIDANCE HAS BACKED OFF SOME AND I HAVE REDUCED POPS OVER THE PLAINS. THE BEST CHANCE OF ANY ACCUM PRECIP STILL APPEARS TO BE OVER THE FAR EASTERN PLAINS...ALTHOUGH IF A SNOW BAND DEVELOPS...(AS SOME GUIDANCE IS HINTING AT)...LOCALLY 1-2" ACCUMS WILL BE POSSIBLE. THE PLAINS WILL HAVE TO BE WATCHED CAREFULLY LATE TODAY TO SEE IF ANY BANDED PRECIP DEVELOPS. /HODANISH .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 400 AM MST FRI NOV 14 2014 ...A COUPLE MORE SYSTEMS TO IMPACT THE AREA THROUGH THE WEEKEND... THE WINTER STORM WARNING WILL REMAIN IN EFFECT FOR THE SAN JUAN AND LA GARITA MOUNTAINS...CONTINENTAL DIVIDE...THROUGH 5 AM SUNDAY. HOWEVER...SOME CONCERN THAT THERE WILL BE A DEFINITE LULL IN THE SNOWFALL SATURDAY AFTERNOON AS THE PACIFIC SHORTWAVE MOVES OUT OF COLORADO. NEXT TROF DROPPING SOUTH OF CANADA WILL IMPACT THE AREA SATURDAY AFTERNOON AND SATURDAY NIGHT. THIS TROF WILL HAVE A WIDER IMPACT ON THE FORECAST AREA AS TEMPERATURES COOL DURING THE DAY SATURDAY WITH FRONT MOVING THROUGH THE PLAINS AND A BAND OF SNOW SETTING UP ALONG THE I-25 CORRIDOR AND THE SOUTHEAST PLAINS SATURDAY NIGHT. GFS HAS MOST OF THE PRECIPITATION/SNOWFALL ALONG THE EAST SLOPES OF THE RAMPARTS AND SANGRES. HUERFANO AND LAS ANIMAS COUNTIES MAY SEE THE BULK OF THE SNOWFALL WITH THIS SYSTEM OVERNIGHT SATURDAY WITH A BAND OF SNOW STRETCHING INTO BACA COUNTY. LATER SHIFTS MAY HAVE TO BALANCE THE WINTER STORM HIGHLIGHTS...MAYBE DOWNGRADING THE WINTER STORM WARNING FOR THE CONTINENTAL DIVIDE AS THE SNOWFALL DIMINISHES...AND AN EYE TOWARD A HIGHLIGHT FOR THE SOUTHERN I-25 CORRIDOR AND SOUTHERN PLAINS. ECMWF AND NAM NOT AS BULLISH ON THE QPF FOR THE SAME AREAS...SO SOME UNCERTAINTY REMAINS. HAVE TRIED TO TIME THE FRONTAL PASSAGE ON THE PLAINS AND FALLING TEMPERATURES DURING THE DAY SATURDAY. TROF CONTINUES TO MOVE SOUTH SUNDAY WITH NORTHWESTERLY FLOW ALOFT EXPECTED TO BRING ANOTHER FRONTAL BOUNDARY THROUGH THE EASTERN PLAINS MONDAY NIGHT...THOUGH TEMPERATURES WILL NOT FALL AS MUCH BEHIND THIS FRONT. SNOW SHOWERS ARE POSSIBLE IN THE CENTRAL MOUNTAINS WITH THIS NORTHWEST FLOW. GENERALLY DRY AND WARMER CONDITIONS ARE EXPECTED TUESDAY THROUGH AT LEAST THURSDAY WITH WESTERLY FLOW ALOFT AND WEAK LEE TROF DEVELOPING AT THE SURFACE. WEATHER PATTERN REMAINS ACTIVE TO OUR NORTH AND WEST AND EXTENDED MODELS DO SHOW ENERGY MOVING INTO THE NORTH CENTRAL MOUNTAINS THURSDAY. STARK && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1055 AM MST FRI NOV 14 2014 MAINLY VFR CONDITIONS EXPECTED AT COS...PUB AND ALS OVER THE NEXT 24 HOURS. WILL SEE INCREASING SHOWERS ACROSS THE HIGHER TERRAIN THROUGH THE AFTERNOON WITH A FEW OF THE MODELS INDICATING A BAND OF PRECIPITATION SPREADING OFF THE HIGHER TERRAIN AND OUT ACROSS THE LOWER ARKANSAS RIVER THIS EVENING. NOT SURE OF THE LOCATION OF THE SAID BAND OF SHOWERS...AND HAVE KEPT VCSH IN TAFS THROUGH 06Z SAT ATTM. IF THIS BAND DOES SET UP...COULD SEE MVFR AND LOCAL IFR CONDITIONS WITH UP TO AN INCH OF SNOW ACCUMS...ESPECIALLY AT ALS AND PUB. THE NEXT ARCTIC FRONT IS POSED TO MOVE ACROSS THE EASTERN PLAINS LATE MORNING AND AFTERNOON...JUST OUT OF THIS TAF PERIOD...WITH GUSTY NORTH TO NORTHEAST WINDS AND LOWERING CIGS EXPECTED AT COS AND PUB AFT 18Z SAT. && .PUB WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 5 AM MST SUNDAY FOR COZ058-060-066- 068. WINTER WEATHER ADVISORY UNTIL 5 AM MST SATURDAY FOR COZ073-075. && $$ SHORT TERM...HODANISH LONG TERM...STARK AVIATION...MW
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
402 PM MST FRI NOV 14 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 357 PM MST FRI NOV 14 2014 COLD FRONT POISED JUST TO THE NORTH OF THE FORECAST AREA THIS AFTERNOON. UPPER LEVEL WESTERLY FLOW PARALLELING THE FRONT AND KEEPING IT FROM MAKING MUCH PROGRESS TO THE SOUTH. SNOW SHOULD BEGIN SPREADING EAST ACROSS CONVERSE/NIOBRARA COUNTIES BETWEEN 00Z-03Z/SAT AND INTO DAWES AND NORTHERN SIOUX COUNTIES IN THE NEBRASKA PANHANDLE BETWEEN 03Z-05Z/SAT. BOTH THE NAM12 AND HRRR KEEP THE SNOW CONFINED TO THESE AREAS THROUGH 06Z/SAT. ABOUT THAT TIME...MORE ROBUST BAND OF SNOW WILL BEGIN TO DEVELOP OVER CARBON COUNTY...ESPECIALLY ALONG THE INTERSTATE 80 CORRIDOR AND THE MEDICINE BOW AND SIERRA MADRE RANGES. STRONGER FRONTAL SURGE COMES AFTER ABOUT 08Z/SAT AND PUSHES TO THE SOUTHERN BORDER OF THE FORECAST AREA BY 13Z/SAT. BEST SNOWFALL ALONG AND EAST OF I-25 SHOULD COME WITH AND SHORTLY BEHIND THE FRONTAL PASSAGE. PLATTE...GOSHEN...AND LARAMIE COUNTIES ALONG WITH THE REMAINDER OF THE PANHANDLE SHOULD SEE 1 TO 3 INCH AMOUNTS. FRONTOGENETIC FORCING DOES FAVOR SOME ENHANCED LIFT IN LARAMIE COUNTY WHERE IMPACTS COULD STILL NECESSITATE AN UPGRADE TO A WINTER WEATHER ADVISORY. THE EVENING SHIFT WILL NEED TO MONITOR TRENDS FROM 00Z OUTPUT CLOSELY. IN ADDITION TO THE SNOW...NORTHERLY WIND OF 15 TO 30 MPH WILL PREVAIL FOLLOWING COLD FRONTAL PASSAGE. ELSEWHERE...ADVISORIES LOOK TO BE IN GOOD SHAPE WITH FORECAST STILL ON THE CORRECT TRACK. AIRMASS SLOWLY DRIES AFTER 18Z/SAT BUT ANY SUN WILL JUST ALLOW FOR COLD AIR STRATOCUMULUS TO DEVELOP. OVERALL... SHOULD BE A MOSTLY CLOUDY DAY. RAPID CLEARING WILL OCCUR AFTER SUNSET SATURDAY. GIVEN A FRESH SNOW COVER AND A LACK OF CLOUDS...WOULD NOT BE SURPRISED TO SEE TEMPERATURES DROP BELOW GUIDANCE. IN OUR FAVOR WOULD BE A CONTINUING WEST WIND IN SOME AREAS THAT WILL HELP KEEP THE BOUNDARY LAYER BETTER MIXED. THOSE AREAS LACKING WIND WILL UNDOUBTEDLY AGAIN SEE SUB-ZERO TEMPERATURES. NORTHERLY FLOW WILL BE REINFORCED SUNDAY AS 100KT+ JET DIVES SOUTH OUT OF SASKATCHEWAN. HIGH-AMPLITUDE RIDGE BUILDING ALONG THE WEST COAST WILL KEEP THE FORECAST AREA IN CYCLONIC FLOW THROUGH AT LEAST SUNDAY NIGHT. TAIL END OF SHORTWAVE ENERGY MOVING THROUGH THE NORTHERN PLAINS WILL BRUSH THE EASTERN TWO-THIRDS OF THE FORECAST AREA SUNDAY. THIS WILL BRING ADDITIONAL CLOUD COVER AND ANOTHER WEAK SHOT OF COLDER AIR. GUSTY NORTHWEST WIND 20 TO 30 MPH WILL MAKE FOR A RAW DAY EVEN WITH TEMPERATURES REBOUNDING FROM THE COLDER AIR OF SATURDAY AND SATURDAY NIGHT. LOW TEMPERATURES SUNDAY NIGHT WILL BE LARGELY DEPENDENT ON HOW MUCH CLOUD COVER REMAINS...ESPECIALLY OVER THE EASTERN PLAINS OF WYOMING AND THE PANHANDLE. .LONG TERM...(MONDAY THROUGH FRIDAY) ISSUED AT 357 PM MST FRI NOV 14 2014 LOOKS LIKE DRY NORTHWEST FLOW ALOFT OVER THE FORECAST AREA FOR MUCH OF THE EXTENDED. GRADIENT IS SUCH THAT BREEZY TO WINDY CONDITIONS WILL PERSIST EARLY IN THE EXTENDED PERIOD. SHORTWAVE RIDGE ALOFT DEPICTED FOR WEDNESDAY AND THURSDAY WITH WARMER TEMPERATURES. CANNOT RULE OUT A FEW SNOW SHOWERS OVER THE SNOWY AND SIERRA MADRE RANGES...POSSIBLY MORE SO FRIDAY WITH PASSAGE OF DEEPENING MID LEVEL TROUGH. WILL HAVE TO SEE HOW THIS TROUGH OR SHORTWAVE EVOLVES FOR LATE THURSDAY NIGHT INTO FRIDAY...BUT NO SIGNIFICANT STORM SYSTEMS DURING THIS PERIOD. TEMPERATURES SHOULD BE AROUND NORMAL. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 357 PM MST FRI NOV 14 2014 VFR CONDITIONS EXPECTED AT ALL TERMINALS UNTIL ABOUT 02Z/SAT. FIRST SURGE OF COLDER AIR WILL BEGIN TO GENERATE LIGHT SNOW GENERALLY ALONG AND NORTH OF A KDGW-KCDR LINE BETWEEN 02Z-05Z. CONDITIONS WILL BECOME MVFR AND EVENTUALLY IFR BY 06Z/SAT AT KCDR. KAIA AND KBFF WILL BEGIN TO GET IN ON THE ACTION WITH MVFR EXPECTED AROUND 06Z/SAT AS THE AREA OF LIGHT SNOW SAGS SLOWLY SOUTH. ABOUT THE SAME TIME... APPEARS THAT A BETTER BAND OF SNOW WILL EXTEND EAST INTO CARBON COUNTY AND IMPACT KRWL BY 08Z/SAT. A SECOND WAVE OF SNOW WILL THEN DEVELOP AS A STRONGER FRONTAL SURGE TRAVERSES THE FORECAST AREA FROM NORTH TO SOUTH FROM 08Z TO 13/SAT. GUSTY NORTHERLY WIND OF 15-30KTS WILL ACCOMPANY AND FOLLOW FRONTAL PASSAGE. IFR AND LIFR CONDITIONS WILL BE WIDESPREAD WITH THE HEAVIEST SNOWFALL LIKELY TO OCCUR BETWEEN ABOUT 10Z-15Z/SAT. DRIER CONDITIONS SHOULD BEGIN TO PUSH ACROSS THE FORECAST AREA FROM NORTH-TO-SOUTH BETWEEN 15Z-20Z/SAT. THERE SHOULD BE ENOUGH COLD AIR ALOFT THAT ANY PARTIAL CLEARING WILL ALLOW FOR STRATOCUMULUS TO FORM...ALTHOUGH CONDITIONS SHOULD BE VFR AFTER ABOUT 19Z/SAT. MOUNTAIN OBSCURATIONS WILL BE WIDESPREAD FROM SHORTLY AFTER 00Z/SAT UNTIL ABOUT 18Z/SAT. MOUNTAIN TOP OBSCURATIONS WILL CONTINUE AFTER THAT TIME UNTIL SUNSET LATE SATURDAY AFTERNOON. && .FIRE WEATHER... ISSUED AT 357 PM MST FRI NOV 14 2014 NO FIRE WEATHER CONCERNS THROUGH THIS WEEKEND. ANOTHER ARCTIC SYSTEM WILL BRING SNOW ACROSS MOST AREAS THROUGH SATURDAY. SEVERAL INCHES OF SNOW WILL ACCUMULATE...ESPECIALLY IN THE HIGHER ELEVATIONS OF SOUTHERN WYOMING. THIS SNOW WILL BE FOLLOWED BY BRISK SURFACE WIND AND COLD TEMPERATURES SUNDAY INTO SUNDAY NIGHT. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...WINTER WEATHER ADVISORY UNTIL 11 AM MST SATURDAY FOR WYZ101>103. WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 1 PM MST SATURDAY FOR WYZ104>106-109>111-113-115>117. WINTER WEATHER ADVISORY UNTIL 11 AM MST SATURDAY FOR WYZ112-114. NE...WINTER WEATHER ADVISORY UNTIL 11 AM MST SATURDAY FOR NEZ002-095. && $$ SHORT TERM...RIW/ZF LONG TERM...RIW/CAH AVIATION...RIW/CAH FIRE WEATHER...RIW/ZF